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7afe21cc | 1 | /* Common subexpression elimination for GNU compiler. |
747215f1 | 2 | Copyright (C) 1987, 88, 89, 92-7, 1998, 1999 Free Software Foundation, Inc. |
7afe21cc RK |
3 | |
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
940d9d63 RK |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
7afe21cc RK |
20 | |
21 | ||
22 | #include "config.h" | |
670ee920 KG |
23 | /* stdio.h must precede rtl.h for FFS. */ |
24 | #include "system.h" | |
50b2596f | 25 | #include <setjmp.h> |
9c3b4c8b | 26 | |
7afe21cc RK |
27 | #include "rtl.h" |
28 | #include "regs.h" | |
29 | #include "hard-reg-set.h" | |
30 | #include "flags.h" | |
31 | #include "real.h" | |
32 | #include "insn-config.h" | |
33 | #include "recog.h" | |
49ad7cfa | 34 | #include "function.h" |
956d6950 | 35 | #include "expr.h" |
50b2596f KG |
36 | #include "toplev.h" |
37 | #include "output.h" | |
30f72379 | 38 | #include "splay-tree.h" |
7afe21cc RK |
39 | |
40 | /* The basic idea of common subexpression elimination is to go | |
41 | through the code, keeping a record of expressions that would | |
42 | have the same value at the current scan point, and replacing | |
43 | expressions encountered with the cheapest equivalent expression. | |
44 | ||
45 | It is too complicated to keep track of the different possibilities | |
46 | when control paths merge; so, at each label, we forget all that is | |
47 | known and start fresh. This can be described as processing each | |
48 | basic block separately. Note, however, that these are not quite | |
49 | the same as the basic blocks found by a later pass and used for | |
50 | data flow analysis and register packing. We do not need to start fresh | |
51 | after a conditional jump instruction if there is no label there. | |
52 | ||
53 | We use two data structures to record the equivalent expressions: | |
54 | a hash table for most expressions, and several vectors together | |
55 | with "quantity numbers" to record equivalent (pseudo) registers. | |
56 | ||
57 | The use of the special data structure for registers is desirable | |
58 | because it is faster. It is possible because registers references | |
59 | contain a fairly small number, the register number, taken from | |
60 | a contiguously allocated series, and two register references are | |
61 | identical if they have the same number. General expressions | |
62 | do not have any such thing, so the only way to retrieve the | |
63 | information recorded on an expression other than a register | |
64 | is to keep it in a hash table. | |
65 | ||
66 | Registers and "quantity numbers": | |
67 | ||
68 | At the start of each basic block, all of the (hardware and pseudo) | |
69 | registers used in the function are given distinct quantity | |
70 | numbers to indicate their contents. During scan, when the code | |
71 | copies one register into another, we copy the quantity number. | |
72 | When a register is loaded in any other way, we allocate a new | |
73 | quantity number to describe the value generated by this operation. | |
74 | `reg_qty' records what quantity a register is currently thought | |
75 | of as containing. | |
76 | ||
77 | All real quantity numbers are greater than or equal to `max_reg'. | |
78 | If register N has not been assigned a quantity, reg_qty[N] will equal N. | |
79 | ||
80 | Quantity numbers below `max_reg' do not exist and none of the `qty_...' | |
81 | variables should be referenced with an index below `max_reg'. | |
82 | ||
83 | We also maintain a bidirectional chain of registers for each | |
84 | quantity number. `qty_first_reg', `qty_last_reg', | |
85 | `reg_next_eqv' and `reg_prev_eqv' hold these chains. | |
86 | ||
87 | The first register in a chain is the one whose lifespan is least local. | |
88 | Among equals, it is the one that was seen first. | |
89 | We replace any equivalent register with that one. | |
90 | ||
91 | If two registers have the same quantity number, it must be true that | |
92 | REG expressions with `qty_mode' must be in the hash table for both | |
93 | registers and must be in the same class. | |
94 | ||
95 | The converse is not true. Since hard registers may be referenced in | |
96 | any mode, two REG expressions might be equivalent in the hash table | |
97 | but not have the same quantity number if the quantity number of one | |
98 | of the registers is not the same mode as those expressions. | |
99 | ||
100 | Constants and quantity numbers | |
101 | ||
102 | When a quantity has a known constant value, that value is stored | |
103 | in the appropriate element of qty_const. This is in addition to | |
104 | putting the constant in the hash table as is usual for non-regs. | |
105 | ||
d45cf215 | 106 | Whether a reg or a constant is preferred is determined by the configuration |
7afe21cc RK |
107 | macro CONST_COSTS and will often depend on the constant value. In any |
108 | event, expressions containing constants can be simplified, by fold_rtx. | |
109 | ||
110 | When a quantity has a known nearly constant value (such as an address | |
111 | of a stack slot), that value is stored in the appropriate element | |
112 | of qty_const. | |
113 | ||
114 | Integer constants don't have a machine mode. However, cse | |
115 | determines the intended machine mode from the destination | |
116 | of the instruction that moves the constant. The machine mode | |
117 | is recorded in the hash table along with the actual RTL | |
118 | constant expression so that different modes are kept separate. | |
119 | ||
120 | Other expressions: | |
121 | ||
122 | To record known equivalences among expressions in general | |
123 | we use a hash table called `table'. It has a fixed number of buckets | |
124 | that contain chains of `struct table_elt' elements for expressions. | |
125 | These chains connect the elements whose expressions have the same | |
126 | hash codes. | |
127 | ||
128 | Other chains through the same elements connect the elements which | |
129 | currently have equivalent values. | |
130 | ||
131 | Register references in an expression are canonicalized before hashing | |
132 | the expression. This is done using `reg_qty' and `qty_first_reg'. | |
133 | The hash code of a register reference is computed using the quantity | |
134 | number, not the register number. | |
135 | ||
136 | When the value of an expression changes, it is necessary to remove from the | |
137 | hash table not just that expression but all expressions whose values | |
138 | could be different as a result. | |
139 | ||
140 | 1. If the value changing is in memory, except in special cases | |
141 | ANYTHING referring to memory could be changed. That is because | |
142 | nobody knows where a pointer does not point. | |
143 | The function `invalidate_memory' removes what is necessary. | |
144 | ||
145 | The special cases are when the address is constant or is | |
146 | a constant plus a fixed register such as the frame pointer | |
147 | or a static chain pointer. When such addresses are stored in, | |
148 | we can tell exactly which other such addresses must be invalidated | |
149 | due to overlap. `invalidate' does this. | |
150 | All expressions that refer to non-constant | |
151 | memory addresses are also invalidated. `invalidate_memory' does this. | |
152 | ||
153 | 2. If the value changing is a register, all expressions | |
154 | containing references to that register, and only those, | |
155 | must be removed. | |
156 | ||
157 | Because searching the entire hash table for expressions that contain | |
158 | a register is very slow, we try to figure out when it isn't necessary. | |
159 | Precisely, this is necessary only when expressions have been | |
160 | entered in the hash table using this register, and then the value has | |
161 | changed, and then another expression wants to be added to refer to | |
162 | the register's new value. This sequence of circumstances is rare | |
163 | within any one basic block. | |
164 | ||
165 | The vectors `reg_tick' and `reg_in_table' are used to detect this case. | |
166 | reg_tick[i] is incremented whenever a value is stored in register i. | |
167 | reg_in_table[i] holds -1 if no references to register i have been | |
168 | entered in the table; otherwise, it contains the value reg_tick[i] had | |
169 | when the references were entered. If we want to enter a reference | |
170 | and reg_in_table[i] != reg_tick[i], we must scan and remove old references. | |
171 | Until we want to enter a new entry, the mere fact that the two vectors | |
172 | don't match makes the entries be ignored if anyone tries to match them. | |
173 | ||
174 | Registers themselves are entered in the hash table as well as in | |
175 | the equivalent-register chains. However, the vectors `reg_tick' | |
176 | and `reg_in_table' do not apply to expressions which are simple | |
177 | register references. These expressions are removed from the table | |
178 | immediately when they become invalid, and this can be done even if | |
179 | we do not immediately search for all the expressions that refer to | |
180 | the register. | |
181 | ||
182 | A CLOBBER rtx in an instruction invalidates its operand for further | |
183 | reuse. A CLOBBER or SET rtx whose operand is a MEM:BLK | |
184 | invalidates everything that resides in memory. | |
185 | ||
186 | Related expressions: | |
187 | ||
188 | Constant expressions that differ only by an additive integer | |
189 | are called related. When a constant expression is put in | |
190 | the table, the related expression with no constant term | |
191 | is also entered. These are made to point at each other | |
192 | so that it is possible to find out if there exists any | |
193 | register equivalent to an expression related to a given expression. */ | |
194 | ||
195 | /* One plus largest register number used in this function. */ | |
196 | ||
197 | static int max_reg; | |
198 | ||
556c714b JW |
199 | /* One plus largest instruction UID used in this function at time of |
200 | cse_main call. */ | |
201 | ||
202 | static int max_insn_uid; | |
203 | ||
7afe21cc RK |
204 | /* Length of vectors indexed by quantity number. |
205 | We know in advance we will not need a quantity number this big. */ | |
206 | ||
207 | static int max_qty; | |
208 | ||
209 | /* Next quantity number to be allocated. | |
210 | This is 1 + the largest number needed so far. */ | |
211 | ||
212 | static int next_qty; | |
213 | ||
71d306d1 | 214 | /* Indexed by quantity number, gives the first (or last) register |
7afe21cc RK |
215 | in the chain of registers that currently contain this quantity. */ |
216 | ||
217 | static int *qty_first_reg; | |
218 | static int *qty_last_reg; | |
219 | ||
220 | /* Index by quantity number, gives the mode of the quantity. */ | |
221 | ||
222 | static enum machine_mode *qty_mode; | |
223 | ||
224 | /* Indexed by quantity number, gives the rtx of the constant value of the | |
225 | quantity, or zero if it does not have a known value. | |
226 | A sum of the frame pointer (or arg pointer) plus a constant | |
227 | can also be entered here. */ | |
228 | ||
229 | static rtx *qty_const; | |
230 | ||
231 | /* Indexed by qty number, gives the insn that stored the constant value | |
232 | recorded in `qty_const'. */ | |
233 | ||
234 | static rtx *qty_const_insn; | |
235 | ||
236 | /* The next three variables are used to track when a comparison between a | |
237 | quantity and some constant or register has been passed. In that case, we | |
238 | know the results of the comparison in case we see it again. These variables | |
239 | record a comparison that is known to be true. */ | |
240 | ||
241 | /* Indexed by qty number, gives the rtx code of a comparison with a known | |
242 | result involving this quantity. If none, it is UNKNOWN. */ | |
243 | static enum rtx_code *qty_comparison_code; | |
244 | ||
245 | /* Indexed by qty number, gives the constant being compared against in a | |
246 | comparison of known result. If no such comparison, it is undefined. | |
247 | If the comparison is not with a constant, it is zero. */ | |
248 | ||
249 | static rtx *qty_comparison_const; | |
250 | ||
251 | /* Indexed by qty number, gives the quantity being compared against in a | |
252 | comparison of known result. If no such comparison, if it undefined. | |
253 | If the comparison is not with a register, it is -1. */ | |
254 | ||
255 | static int *qty_comparison_qty; | |
256 | ||
257 | #ifdef HAVE_cc0 | |
258 | /* For machines that have a CC0, we do not record its value in the hash | |
259 | table since its use is guaranteed to be the insn immediately following | |
260 | its definition and any other insn is presumed to invalidate it. | |
261 | ||
262 | Instead, we store below the value last assigned to CC0. If it should | |
263 | happen to be a constant, it is stored in preference to the actual | |
264 | assigned value. In case it is a constant, we store the mode in which | |
265 | the constant should be interpreted. */ | |
266 | ||
267 | static rtx prev_insn_cc0; | |
268 | static enum machine_mode prev_insn_cc0_mode; | |
269 | #endif | |
270 | ||
271 | /* Previous actual insn. 0 if at first insn of basic block. */ | |
272 | ||
273 | static rtx prev_insn; | |
274 | ||
275 | /* Insn being scanned. */ | |
276 | ||
277 | static rtx this_insn; | |
278 | ||
71d306d1 DE |
279 | /* Index by register number, gives the number of the next (or |
280 | previous) register in the chain of registers sharing the same | |
7afe21cc RK |
281 | value. |
282 | ||
283 | Or -1 if this register is at the end of the chain. | |
284 | ||
285 | If reg_qty[N] == N, reg_next_eqv[N] is undefined. */ | |
286 | ||
287 | static int *reg_next_eqv; | |
288 | static int *reg_prev_eqv; | |
289 | ||
30f72379 MM |
290 | struct cse_reg_info { |
291 | union { | |
292 | /* The number of times the register has been altered in the current | |
293 | basic block. */ | |
294 | int reg_tick; | |
295 | ||
296 | /* The next cse_reg_info structure in the free list. */ | |
297 | struct cse_reg_info* next; | |
298 | } variant; | |
299 | ||
300 | /* The REG_TICK value at which rtx's containing this register are | |
301 | valid in the hash table. If this does not equal the current | |
302 | reg_tick value, such expressions existing in the hash table are | |
303 | invalid. */ | |
304 | int reg_in_table; | |
305 | ||
306 | /* The quantity number of the register's current contents. */ | |
307 | int reg_qty; | |
308 | }; | |
7afe21cc | 309 | |
30f72379 MM |
310 | /* A free list of cse_reg_info entries. */ |
311 | static struct cse_reg_info *cse_reg_info_free_list; | |
7afe21cc | 312 | |
30f72379 MM |
313 | /* A mapping from registers to cse_reg_info data structures. */ |
314 | static splay_tree cse_reg_info_tree; | |
7afe21cc | 315 | |
30f72379 MM |
316 | /* The last lookup we did into the cse_reg_info_tree. This allows us |
317 | to cache repeated lookups. */ | |
318 | static int cached_regno; | |
319 | static struct cse_reg_info *cached_cse_reg_info; | |
7afe21cc RK |
320 | |
321 | /* A HARD_REG_SET containing all the hard registers for which there is | |
322 | currently a REG expression in the hash table. Note the difference | |
323 | from the above variables, which indicate if the REG is mentioned in some | |
324 | expression in the table. */ | |
325 | ||
326 | static HARD_REG_SET hard_regs_in_table; | |
327 | ||
328 | /* A HARD_REG_SET containing all the hard registers that are invalidated | |
329 | by a CALL_INSN. */ | |
330 | ||
331 | static HARD_REG_SET regs_invalidated_by_call; | |
332 | ||
7afe21cc RK |
333 | /* CUID of insn that starts the basic block currently being cse-processed. */ |
334 | ||
335 | static int cse_basic_block_start; | |
336 | ||
337 | /* CUID of insn that ends the basic block currently being cse-processed. */ | |
338 | ||
339 | static int cse_basic_block_end; | |
340 | ||
341 | /* Vector mapping INSN_UIDs to cuids. | |
d45cf215 | 342 | The cuids are like uids but increase monotonically always. |
7afe21cc RK |
343 | We use them to see whether a reg is used outside a given basic block. */ |
344 | ||
906c4e36 | 345 | static int *uid_cuid; |
7afe21cc | 346 | |
164c8956 RK |
347 | /* Highest UID in UID_CUID. */ |
348 | static int max_uid; | |
349 | ||
7afe21cc RK |
350 | /* Get the cuid of an insn. */ |
351 | ||
352 | #define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)]) | |
353 | ||
354 | /* Nonzero if cse has altered conditional jump insns | |
355 | in such a way that jump optimization should be redone. */ | |
356 | ||
357 | static int cse_jumps_altered; | |
358 | ||
a5dfb4ee RK |
359 | /* Nonzero if we put a LABEL_REF into the hash table. Since we may have put |
360 | it into an INSN without a REG_LABEL, we have to rerun jump after CSE | |
361 | to put in the note. */ | |
362 | static int recorded_label_ref; | |
363 | ||
7afe21cc RK |
364 | /* canon_hash stores 1 in do_not_record |
365 | if it notices a reference to CC0, PC, or some other volatile | |
366 | subexpression. */ | |
367 | ||
368 | static int do_not_record; | |
369 | ||
7bac1be0 RK |
370 | #ifdef LOAD_EXTEND_OP |
371 | ||
372 | /* Scratch rtl used when looking for load-extended copy of a MEM. */ | |
373 | static rtx memory_extend_rtx; | |
374 | #endif | |
375 | ||
7afe21cc RK |
376 | /* canon_hash stores 1 in hash_arg_in_memory |
377 | if it notices a reference to memory within the expression being hashed. */ | |
378 | ||
379 | static int hash_arg_in_memory; | |
380 | ||
381 | /* canon_hash stores 1 in hash_arg_in_struct | |
382 | if it notices a reference to memory that's part of a structure. */ | |
383 | ||
384 | static int hash_arg_in_struct; | |
385 | ||
386 | /* The hash table contains buckets which are chains of `struct table_elt's, | |
387 | each recording one expression's information. | |
388 | That expression is in the `exp' field. | |
389 | ||
390 | Those elements with the same hash code are chained in both directions | |
391 | through the `next_same_hash' and `prev_same_hash' fields. | |
392 | ||
393 | Each set of expressions with equivalent values | |
394 | are on a two-way chain through the `next_same_value' | |
395 | and `prev_same_value' fields, and all point with | |
396 | the `first_same_value' field at the first element in | |
397 | that chain. The chain is in order of increasing cost. | |
398 | Each element's cost value is in its `cost' field. | |
399 | ||
400 | The `in_memory' field is nonzero for elements that | |
401 | involve any reference to memory. These elements are removed | |
402 | whenever a write is done to an unidentified location in memory. | |
403 | To be safe, we assume that a memory address is unidentified unless | |
404 | the address is either a symbol constant or a constant plus | |
405 | the frame pointer or argument pointer. | |
406 | ||
407 | The `in_struct' field is nonzero for elements that | |
408 | involve any reference to memory inside a structure or array. | |
409 | ||
410 | The `related_value' field is used to connect related expressions | |
411 | (that differ by adding an integer). | |
412 | The related expressions are chained in a circular fashion. | |
413 | `related_value' is zero for expressions for which this | |
414 | chain is not useful. | |
415 | ||
416 | The `cost' field stores the cost of this element's expression. | |
417 | ||
418 | The `is_const' flag is set if the element is a constant (including | |
419 | a fixed address). | |
420 | ||
421 | The `flag' field is used as a temporary during some search routines. | |
422 | ||
423 | The `mode' field is usually the same as GET_MODE (`exp'), but | |
424 | if `exp' is a CONST_INT and has no machine mode then the `mode' | |
425 | field is the mode it was being used as. Each constant is | |
426 | recorded separately for each mode it is used with. */ | |
427 | ||
428 | ||
429 | struct table_elt | |
430 | { | |
431 | rtx exp; | |
432 | struct table_elt *next_same_hash; | |
433 | struct table_elt *prev_same_hash; | |
434 | struct table_elt *next_same_value; | |
435 | struct table_elt *prev_same_value; | |
436 | struct table_elt *first_same_value; | |
437 | struct table_elt *related_value; | |
438 | int cost; | |
439 | enum machine_mode mode; | |
440 | char in_memory; | |
441 | char in_struct; | |
442 | char is_const; | |
443 | char flag; | |
444 | }; | |
445 | ||
7afe21cc RK |
446 | /* We don't want a lot of buckets, because we rarely have very many |
447 | things stored in the hash table, and a lot of buckets slows | |
448 | down a lot of loops that happen frequently. */ | |
449 | #define NBUCKETS 31 | |
450 | ||
451 | /* Compute hash code of X in mode M. Special-case case where X is a pseudo | |
452 | register (hard registers may require `do_not_record' to be set). */ | |
453 | ||
454 | #define HASH(X, M) \ | |
455 | (GET_CODE (X) == REG && REGNO (X) >= FIRST_PSEUDO_REGISTER \ | |
30f72379 | 456 | ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X))) % NBUCKETS \ |
7afe21cc RK |
457 | : canon_hash (X, M) % NBUCKETS) |
458 | ||
459 | /* Determine whether register number N is considered a fixed register for CSE. | |
460 | It is desirable to replace other regs with fixed regs, to reduce need for | |
461 | non-fixed hard regs. | |
462 | A reg wins if it is either the frame pointer or designated as fixed, | |
463 | but not if it is an overlapping register. */ | |
464 | #ifdef OVERLAPPING_REGNO_P | |
465 | #define FIXED_REGNO_P(N) \ | |
8bc169f2 | 466 | (((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \ |
6ab832bc | 467 | || fixed_regs[N] || global_regs[N]) \ |
7afe21cc RK |
468 | && ! OVERLAPPING_REGNO_P ((N))) |
469 | #else | |
470 | #define FIXED_REGNO_P(N) \ | |
8bc169f2 | 471 | ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \ |
6ab832bc | 472 | || fixed_regs[N] || global_regs[N]) |
7afe21cc RK |
473 | #endif |
474 | ||
475 | /* Compute cost of X, as stored in the `cost' field of a table_elt. Fixed | |
ac07e066 RK |
476 | hard registers and pointers into the frame are the cheapest with a cost |
477 | of 0. Next come pseudos with a cost of one and other hard registers with | |
478 | a cost of 2. Aside from these special cases, call `rtx_cost'. */ | |
479 | ||
6ab832bc | 480 | #define CHEAP_REGNO(N) \ |
8bc169f2 DE |
481 | ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \ |
482 | || (N) == STACK_POINTER_REGNUM || (N) == ARG_POINTER_REGNUM \ | |
483 | || ((N) >= FIRST_VIRTUAL_REGISTER && (N) <= LAST_VIRTUAL_REGISTER) \ | |
484 | || ((N) < FIRST_PSEUDO_REGISTER \ | |
e7bb59fa | 485 | && FIXED_REGNO_P (N) && REGNO_REG_CLASS (N) != NO_REGS)) |
7afe21cc | 486 | |
6ab832bc RK |
487 | /* A register is cheap if it is a user variable assigned to the register |
488 | or if its register number always corresponds to a cheap register. */ | |
489 | ||
490 | #define CHEAP_REG(N) \ | |
491 | ((REG_USERVAR_P (N) && REGNO (N) < FIRST_PSEUDO_REGISTER) \ | |
492 | || CHEAP_REGNO (REGNO (N))) | |
493 | ||
38734e55 ILT |
494 | #define COST(X) \ |
495 | (GET_CODE (X) == REG \ | |
496 | ? (CHEAP_REG (X) ? 0 \ | |
497 | : REGNO (X) >= FIRST_PSEUDO_REGISTER ? 1 \ | |
498 | : 2) \ | |
954a5693 | 499 | : notreg_cost(X)) |
7afe21cc | 500 | |
30f72379 MM |
501 | /* Get the info associated with register N. */ |
502 | ||
503 | #define GET_CSE_REG_INFO(N) \ | |
504 | (((N) == cached_regno && cached_cse_reg_info) \ | |
505 | ? cached_cse_reg_info : get_cse_reg_info ((N))) | |
506 | ||
507 | /* Get the number of times this register has been updated in this | |
508 | basic block. */ | |
509 | ||
510 | #define REG_TICK(N) ((GET_CSE_REG_INFO (N))->variant.reg_tick) | |
511 | ||
512 | /* Get the point at which REG was recorded in the table. */ | |
513 | ||
514 | #define REG_IN_TABLE(N) ((GET_CSE_REG_INFO (N))->reg_in_table) | |
515 | ||
516 | /* Get the quantity number for REG. */ | |
517 | ||
518 | #define REG_QTY(N) ((GET_CSE_REG_INFO (N))->reg_qty) | |
519 | ||
7afe21cc RK |
520 | /* Determine if the quantity number for register X represents a valid index |
521 | into the `qty_...' variables. */ | |
522 | ||
30f72379 | 523 | #define REGNO_QTY_VALID_P(N) (REG_QTY (N) != (N)) |
7afe21cc | 524 | |
2f541799 MM |
525 | #ifdef ADDRESS_COST |
526 | /* The ADDRESS_COST macro does not deal with ADDRESSOF nodes. But, | |
527 | during CSE, such nodes are present. Using an ADDRESSOF node which | |
528 | refers to the address of a REG is a good thing because we can then | |
529 | turn (MEM (ADDRESSSOF (REG))) into just plain REG. */ | |
530 | #define CSE_ADDRESS_COST(RTX) \ | |
531 | ((GET_CODE (RTX) == ADDRESSOF && REG_P (XEXP ((RTX), 0))) \ | |
532 | ? -1 : ADDRESS_COST(RTX)) | |
533 | #endif | |
534 | ||
7afe21cc RK |
535 | static struct table_elt *table[NBUCKETS]; |
536 | ||
537 | /* Chain of `struct table_elt's made so far for this function | |
538 | but currently removed from the table. */ | |
539 | ||
540 | static struct table_elt *free_element_chain; | |
541 | ||
542 | /* Number of `struct table_elt' structures made so far for this function. */ | |
543 | ||
544 | static int n_elements_made; | |
545 | ||
546 | /* Maximum value `n_elements_made' has had so far in this compilation | |
547 | for functions previously processed. */ | |
548 | ||
549 | static int max_elements_made; | |
550 | ||
551 | /* Surviving equivalence class when two equivalence classes are merged | |
552 | by recording the effects of a jump in the last insn. Zero if the | |
553 | last insn was not a conditional jump. */ | |
554 | ||
555 | static struct table_elt *last_jump_equiv_class; | |
556 | ||
557 | /* Set to the cost of a constant pool reference if one was found for a | |
558 | symbolic constant. If this was found, it means we should try to | |
559 | convert constants into constant pool entries if they don't fit in | |
560 | the insn. */ | |
561 | ||
562 | static int constant_pool_entries_cost; | |
563 | ||
6cd4575e RK |
564 | /* Define maximum length of a branch path. */ |
565 | ||
566 | #define PATHLENGTH 10 | |
567 | ||
568 | /* This data describes a block that will be processed by cse_basic_block. */ | |
569 | ||
570 | struct cse_basic_block_data { | |
571 | /* Lowest CUID value of insns in block. */ | |
572 | int low_cuid; | |
573 | /* Highest CUID value of insns in block. */ | |
574 | int high_cuid; | |
575 | /* Total number of SETs in block. */ | |
576 | int nsets; | |
577 | /* Last insn in the block. */ | |
578 | rtx last; | |
579 | /* Size of current branch path, if any. */ | |
580 | int path_size; | |
581 | /* Current branch path, indicating which branches will be taken. */ | |
582 | struct branch_path { | |
0f41302f | 583 | /* The branch insn. */ |
6cd4575e RK |
584 | rtx branch; |
585 | /* Whether it should be taken or not. AROUND is the same as taken | |
586 | except that it is used when the destination label is not preceded | |
587 | by a BARRIER. */ | |
588 | enum taken {TAKEN, NOT_TAKEN, AROUND} status; | |
589 | } path[PATHLENGTH]; | |
590 | }; | |
591 | ||
7afe21cc RK |
592 | /* Nonzero if X has the form (PLUS frame-pointer integer). We check for |
593 | virtual regs here because the simplify_*_operation routines are called | |
594 | by integrate.c, which is called before virtual register instantiation. */ | |
595 | ||
596 | #define FIXED_BASE_PLUS_P(X) \ | |
8bc169f2 DE |
597 | ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \ |
598 | || (X) == arg_pointer_rtx \ | |
7afe21cc RK |
599 | || (X) == virtual_stack_vars_rtx \ |
600 | || (X) == virtual_incoming_args_rtx \ | |
601 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
602 | && (XEXP (X, 0) == frame_pointer_rtx \ | |
8bc169f2 | 603 | || XEXP (X, 0) == hard_frame_pointer_rtx \ |
7afe21cc RK |
604 | || XEXP (X, 0) == arg_pointer_rtx \ |
605 | || XEXP (X, 0) == virtual_stack_vars_rtx \ | |
e9a25f70 JL |
606 | || XEXP (X, 0) == virtual_incoming_args_rtx)) \ |
607 | || GET_CODE (X) == ADDRESSOF) | |
7afe21cc | 608 | |
6f90e075 JW |
609 | /* Similar, but also allows reference to the stack pointer. |
610 | ||
611 | This used to include FIXED_BASE_PLUS_P, however, we can't assume that | |
612 | arg_pointer_rtx by itself is nonzero, because on at least one machine, | |
613 | the i960, the arg pointer is zero when it is unused. */ | |
7afe21cc RK |
614 | |
615 | #define NONZERO_BASE_PLUS_P(X) \ | |
8bc169f2 | 616 | ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \ |
6f90e075 JW |
617 | || (X) == virtual_stack_vars_rtx \ |
618 | || (X) == virtual_incoming_args_rtx \ | |
619 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
620 | && (XEXP (X, 0) == frame_pointer_rtx \ | |
8bc169f2 | 621 | || XEXP (X, 0) == hard_frame_pointer_rtx \ |
6f90e075 JW |
622 | || XEXP (X, 0) == arg_pointer_rtx \ |
623 | || XEXP (X, 0) == virtual_stack_vars_rtx \ | |
624 | || XEXP (X, 0) == virtual_incoming_args_rtx)) \ | |
7afe21cc RK |
625 | || (X) == stack_pointer_rtx \ |
626 | || (X) == virtual_stack_dynamic_rtx \ | |
627 | || (X) == virtual_outgoing_args_rtx \ | |
628 | || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ | |
629 | && (XEXP (X, 0) == stack_pointer_rtx \ | |
630 | || XEXP (X, 0) == virtual_stack_dynamic_rtx \ | |
e9a25f70 JL |
631 | || XEXP (X, 0) == virtual_outgoing_args_rtx)) \ |
632 | || GET_CODE (X) == ADDRESSOF) | |
7afe21cc | 633 | |
954a5693 | 634 | static int notreg_cost PROTO((rtx)); |
6cd4575e RK |
635 | static void new_basic_block PROTO((void)); |
636 | static void make_new_qty PROTO((int)); | |
637 | static void make_regs_eqv PROTO((int, int)); | |
638 | static void delete_reg_equiv PROTO((int)); | |
639 | static int mention_regs PROTO((rtx)); | |
640 | static int insert_regs PROTO((rtx, struct table_elt *, int)); | |
641 | static void free_element PROTO((struct table_elt *)); | |
2197a88a | 642 | static void remove_from_table PROTO((struct table_elt *, unsigned)); |
6cd4575e | 643 | static struct table_elt *get_element PROTO((void)); |
2197a88a RK |
644 | static struct table_elt *lookup PROTO((rtx, unsigned, enum machine_mode)), |
645 | *lookup_for_remove PROTO((rtx, unsigned, enum machine_mode)); | |
6cd4575e | 646 | static rtx lookup_as_function PROTO((rtx, enum rtx_code)); |
2197a88a | 647 | static struct table_elt *insert PROTO((rtx, struct table_elt *, unsigned, |
6cd4575e RK |
648 | enum machine_mode)); |
649 | static void merge_equiv_classes PROTO((struct table_elt *, | |
650 | struct table_elt *)); | |
68c1e173 | 651 | static void invalidate PROTO((rtx, enum machine_mode)); |
9ae8ffe7 | 652 | static int cse_rtx_varies_p PROTO((rtx)); |
6cd4575e | 653 | static void remove_invalid_refs PROTO((int)); |
34c73909 | 654 | static void remove_invalid_subreg_refs PROTO((int, int, enum machine_mode)); |
6cd4575e | 655 | static void rehash_using_reg PROTO((rtx)); |
9ae8ffe7 | 656 | static void invalidate_memory PROTO((void)); |
6cd4575e RK |
657 | static void invalidate_for_call PROTO((void)); |
658 | static rtx use_related_value PROTO((rtx, struct table_elt *)); | |
2197a88a RK |
659 | static unsigned canon_hash PROTO((rtx, enum machine_mode)); |
660 | static unsigned safe_hash PROTO((rtx, enum machine_mode)); | |
6cd4575e | 661 | static int exp_equiv_p PROTO((rtx, rtx, int, int)); |
f451db89 | 662 | static void set_nonvarying_address_components PROTO((rtx, int, rtx *, |
6500fb43 RK |
663 | HOST_WIDE_INT *, |
664 | HOST_WIDE_INT *)); | |
6cd4575e | 665 | static int refers_to_p PROTO((rtx, rtx)); |
6cd4575e RK |
666 | static rtx canon_reg PROTO((rtx, rtx)); |
667 | static void find_best_addr PROTO((rtx, rtx *)); | |
668 | static enum rtx_code find_comparison_args PROTO((enum rtx_code, rtx *, rtx *, | |
669 | enum machine_mode *, | |
670 | enum machine_mode *)); | |
96b0e481 RK |
671 | static rtx cse_gen_binary PROTO((enum rtx_code, enum machine_mode, |
672 | rtx, rtx)); | |
673 | static rtx simplify_plus_minus PROTO((enum rtx_code, enum machine_mode, | |
674 | rtx, rtx)); | |
6cd4575e RK |
675 | static rtx fold_rtx PROTO((rtx, rtx)); |
676 | static rtx equiv_constant PROTO((rtx)); | |
677 | static void record_jump_equiv PROTO((rtx, int)); | |
678 | static void record_jump_cond PROTO((enum rtx_code, enum machine_mode, | |
679 | rtx, rtx, int)); | |
7bd8b2a8 | 680 | static void cse_insn PROTO((rtx, rtx)); |
9ae8ffe7 JL |
681 | static int note_mem_written PROTO((rtx)); |
682 | static void invalidate_from_clobbers PROTO((rtx)); | |
6cd4575e RK |
683 | static rtx cse_process_notes PROTO((rtx, rtx)); |
684 | static void cse_around_loop PROTO((rtx)); | |
685 | static void invalidate_skipped_set PROTO((rtx, rtx)); | |
686 | static void invalidate_skipped_block PROTO((rtx)); | |
687 | static void cse_check_loop_start PROTO((rtx, rtx)); | |
688 | static void cse_set_around_loop PROTO((rtx, rtx, rtx)); | |
689 | static rtx cse_basic_block PROTO((rtx, rtx, struct branch_path *, int)); | |
79644f06 | 690 | static void count_reg_usage PROTO((rtx, int *, rtx, int)); |
a0153051 | 691 | extern void dump_class PROTO((struct table_elt*)); |
1a87eea2 | 692 | static void check_fold_consts PROTO((PTR)); |
30f72379 MM |
693 | static struct cse_reg_info* get_cse_reg_info PROTO((int)); |
694 | static void free_cse_reg_info PROTO((splay_tree_value)); | |
01e752d3 | 695 | static void flush_hash_table PROTO((void)); |
c407b802 RK |
696 | |
697 | extern int rtx_equal_function_value_matters; | |
7afe21cc | 698 | \f |
a4c6502a MM |
699 | /* Dump the expressions in the equivalence class indicated by CLASSP. |
700 | This function is used only for debugging. */ | |
a0153051 | 701 | void |
a4c6502a MM |
702 | dump_class (classp) |
703 | struct table_elt *classp; | |
704 | { | |
705 | struct table_elt *elt; | |
706 | ||
707 | fprintf (stderr, "Equivalence chain for "); | |
708 | print_rtl (stderr, classp->exp); | |
709 | fprintf (stderr, ": \n"); | |
710 | ||
711 | for (elt = classp->first_same_value; elt; elt = elt->next_same_value) | |
712 | { | |
713 | print_rtl (stderr, elt->exp); | |
714 | fprintf (stderr, "\n"); | |
715 | } | |
716 | } | |
717 | ||
7afe21cc RK |
718 | /* Return an estimate of the cost of computing rtx X. |
719 | One use is in cse, to decide which expression to keep in the hash table. | |
720 | Another is in rtl generation, to pick the cheapest way to multiply. | |
721 | Other uses like the latter are expected in the future. */ | |
722 | ||
954a5693 RK |
723 | /* Internal function, to compute cost when X is not a register; called |
724 | from COST macro to keep it simple. */ | |
725 | ||
726 | static int | |
727 | notreg_cost (x) | |
728 | rtx x; | |
729 | { | |
730 | return ((GET_CODE (x) == SUBREG | |
731 | && GET_CODE (SUBREG_REG (x)) == REG | |
732 | && GET_MODE_CLASS (GET_MODE (x)) == MODE_INT | |
733 | && GET_MODE_CLASS (GET_MODE (SUBREG_REG (x))) == MODE_INT | |
734 | && (GET_MODE_SIZE (GET_MODE (x)) | |
735 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) | |
736 | && subreg_lowpart_p (x) | |
737 | && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (x)), | |
738 | GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))))) | |
739 | ? (CHEAP_REG (SUBREG_REG (x)) ? 0 | |
740 | : (REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER ? 1 | |
741 | : 2)) | |
742 | : rtx_cost (x, SET) * 2); | |
743 | } | |
744 | ||
7afe21cc RK |
745 | /* Return the right cost to give to an operation |
746 | to make the cost of the corresponding register-to-register instruction | |
747 | N times that of a fast register-to-register instruction. */ | |
748 | ||
749 | #define COSTS_N_INSNS(N) ((N) * 4 - 2) | |
750 | ||
751 | int | |
e5f6a288 | 752 | rtx_cost (x, outer_code) |
7afe21cc | 753 | rtx x; |
79c9824e | 754 | enum rtx_code outer_code ATTRIBUTE_UNUSED; |
7afe21cc RK |
755 | { |
756 | register int i, j; | |
757 | register enum rtx_code code; | |
758 | register char *fmt; | |
759 | register int total; | |
760 | ||
761 | if (x == 0) | |
762 | return 0; | |
763 | ||
764 | /* Compute the default costs of certain things. | |
765 | Note that RTX_COSTS can override the defaults. */ | |
766 | ||
767 | code = GET_CODE (x); | |
768 | switch (code) | |
769 | { | |
770 | case MULT: | |
771 | /* Count multiplication by 2**n as a shift, | |
772 | because if we are considering it, we would output it as a shift. */ | |
773 | if (GET_CODE (XEXP (x, 1)) == CONST_INT | |
774 | && exact_log2 (INTVAL (XEXP (x, 1))) >= 0) | |
775 | total = 2; | |
776 | else | |
777 | total = COSTS_N_INSNS (5); | |
778 | break; | |
779 | case DIV: | |
780 | case UDIV: | |
781 | case MOD: | |
782 | case UMOD: | |
783 | total = COSTS_N_INSNS (7); | |
784 | break; | |
785 | case USE: | |
786 | /* Used in loop.c and combine.c as a marker. */ | |
787 | total = 0; | |
788 | break; | |
538b78e7 RS |
789 | case ASM_OPERANDS: |
790 | /* We don't want these to be used in substitutions because | |
791 | we have no way of validating the resulting insn. So assign | |
792 | anything containing an ASM_OPERANDS a very high cost. */ | |
793 | total = 1000; | |
794 | break; | |
7afe21cc RK |
795 | default: |
796 | total = 2; | |
797 | } | |
798 | ||
799 | switch (code) | |
800 | { | |
801 | case REG: | |
6ab832bc | 802 | return ! CHEAP_REG (x); |
ac07e066 | 803 | |
7afe21cc | 804 | case SUBREG: |
fc3ffe83 RK |
805 | /* If we can't tie these modes, make this expensive. The larger |
806 | the mode, the more expensive it is. */ | |
807 | if (! MODES_TIEABLE_P (GET_MODE (x), GET_MODE (SUBREG_REG (x)))) | |
808 | return COSTS_N_INSNS (2 | |
809 | + GET_MODE_SIZE (GET_MODE (x)) / UNITS_PER_WORD); | |
7afe21cc RK |
810 | return 2; |
811 | #ifdef RTX_COSTS | |
e5f6a288 | 812 | RTX_COSTS (x, code, outer_code); |
7afe21cc | 813 | #endif |
47a0b68f | 814 | #ifdef CONST_COSTS |
e5f6a288 | 815 | CONST_COSTS (x, code, outer_code); |
47a0b68f | 816 | #endif |
8625fab5 KG |
817 | |
818 | default: | |
819 | #ifdef DEFAULT_RTX_COSTS | |
820 | DEFAULT_RTX_COSTS(x, code, outer_code); | |
821 | #endif | |
822 | break; | |
7afe21cc RK |
823 | } |
824 | ||
825 | /* Sum the costs of the sub-rtx's, plus cost of this operation, | |
826 | which is already in total. */ | |
827 | ||
828 | fmt = GET_RTX_FORMAT (code); | |
829 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
830 | if (fmt[i] == 'e') | |
e5f6a288 | 831 | total += rtx_cost (XEXP (x, i), code); |
7afe21cc RK |
832 | else if (fmt[i] == 'E') |
833 | for (j = 0; j < XVECLEN (x, i); j++) | |
e5f6a288 | 834 | total += rtx_cost (XVECEXP (x, i, j), code); |
7afe21cc RK |
835 | |
836 | return total; | |
837 | } | |
838 | \f | |
30f72379 MM |
839 | static struct cse_reg_info * |
840 | get_cse_reg_info (regno) | |
841 | int regno; | |
842 | { | |
843 | struct cse_reg_info *cri; | |
844 | splay_tree_node n; | |
845 | ||
846 | /* See if we already have this entry. */ | |
847 | n = splay_tree_lookup (cse_reg_info_tree, | |
848 | (splay_tree_key) regno); | |
849 | if (n) | |
850 | cri = (struct cse_reg_info *) (n->value); | |
851 | else | |
852 | { | |
853 | /* Get a new cse_reg_info structure. */ | |
854 | if (cse_reg_info_free_list) | |
855 | { | |
856 | cri = cse_reg_info_free_list; | |
857 | cse_reg_info_free_list = cri->variant.next; | |
858 | } | |
859 | else | |
860 | cri = (struct cse_reg_info *) xmalloc (sizeof (struct cse_reg_info)); | |
861 | ||
862 | /* Initialize it. */ | |
863 | cri->variant.reg_tick = 0; | |
864 | cri->reg_in_table = -1; | |
865 | cri->reg_qty = regno; | |
866 | ||
867 | splay_tree_insert (cse_reg_info_tree, | |
868 | (splay_tree_key) regno, | |
869 | (splay_tree_value) cri); | |
870 | } | |
871 | ||
872 | /* Cache this lookup; we tend to be looking up information about the | |
873 | same register several times in a row. */ | |
874 | cached_regno = regno; | |
875 | cached_cse_reg_info = cri; | |
876 | ||
877 | return cri; | |
878 | } | |
879 | ||
880 | static void | |
881 | free_cse_reg_info (v) | |
882 | splay_tree_value v; | |
883 | { | |
884 | struct cse_reg_info *cri = (struct cse_reg_info *) v; | |
885 | ||
886 | cri->variant.next = cse_reg_info_free_list; | |
887 | cse_reg_info_free_list = cri; | |
888 | } | |
889 | ||
7afe21cc RK |
890 | /* Clear the hash table and initialize each register with its own quantity, |
891 | for a new basic block. */ | |
892 | ||
893 | static void | |
894 | new_basic_block () | |
895 | { | |
896 | register int i; | |
897 | ||
898 | next_qty = max_reg; | |
899 | ||
30f72379 MM |
900 | if (cse_reg_info_tree) |
901 | { | |
902 | splay_tree_delete (cse_reg_info_tree); | |
903 | cached_cse_reg_info = 0; | |
904 | } | |
905 | ||
906 | cse_reg_info_tree = splay_tree_new (splay_tree_compare_ints, 0, | |
907 | free_cse_reg_info); | |
7afe21cc | 908 | |
7afe21cc RK |
909 | CLEAR_HARD_REG_SET (hard_regs_in_table); |
910 | ||
911 | /* The per-quantity values used to be initialized here, but it is | |
912 | much faster to initialize each as it is made in `make_new_qty'. */ | |
913 | ||
914 | for (i = 0; i < NBUCKETS; i++) | |
915 | { | |
916 | register struct table_elt *this, *next; | |
917 | for (this = table[i]; this; this = next) | |
918 | { | |
919 | next = this->next_same_hash; | |
920 | free_element (this); | |
921 | } | |
922 | } | |
923 | ||
4c9a05bc | 924 | bzero ((char *) table, sizeof table); |
7afe21cc RK |
925 | |
926 | prev_insn = 0; | |
927 | ||
928 | #ifdef HAVE_cc0 | |
929 | prev_insn_cc0 = 0; | |
930 | #endif | |
931 | } | |
932 | ||
933 | /* Say that register REG contains a quantity not in any register before | |
934 | and initialize that quantity. */ | |
935 | ||
936 | static void | |
937 | make_new_qty (reg) | |
938 | register int reg; | |
939 | { | |
940 | register int q; | |
941 | ||
942 | if (next_qty >= max_qty) | |
943 | abort (); | |
944 | ||
30f72379 | 945 | q = REG_QTY (reg) = next_qty++; |
7afe21cc RK |
946 | qty_first_reg[q] = reg; |
947 | qty_last_reg[q] = reg; | |
948 | qty_const[q] = qty_const_insn[q] = 0; | |
949 | qty_comparison_code[q] = UNKNOWN; | |
950 | ||
951 | reg_next_eqv[reg] = reg_prev_eqv[reg] = -1; | |
952 | } | |
953 | ||
954 | /* Make reg NEW equivalent to reg OLD. | |
955 | OLD is not changing; NEW is. */ | |
956 | ||
957 | static void | |
958 | make_regs_eqv (new, old) | |
959 | register int new, old; | |
960 | { | |
961 | register int lastr, firstr; | |
30f72379 | 962 | register int q = REG_QTY (old); |
7afe21cc RK |
963 | |
964 | /* Nothing should become eqv until it has a "non-invalid" qty number. */ | |
965 | if (! REGNO_QTY_VALID_P (old)) | |
966 | abort (); | |
967 | ||
30f72379 | 968 | REG_QTY (new) = q; |
7afe21cc RK |
969 | firstr = qty_first_reg[q]; |
970 | lastr = qty_last_reg[q]; | |
971 | ||
972 | /* Prefer fixed hard registers to anything. Prefer pseudo regs to other | |
973 | hard regs. Among pseudos, if NEW will live longer than any other reg | |
974 | of the same qty, and that is beyond the current basic block, | |
975 | make it the new canonical replacement for this qty. */ | |
976 | if (! (firstr < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (firstr)) | |
977 | /* Certain fixed registers might be of the class NO_REGS. This means | |
978 | that not only can they not be allocated by the compiler, but | |
830a38ee | 979 | they cannot be used in substitutions or canonicalizations |
7afe21cc RK |
980 | either. */ |
981 | && (new >= FIRST_PSEUDO_REGISTER || REGNO_REG_CLASS (new) != NO_REGS) | |
982 | && ((new < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (new)) | |
983 | || (new >= FIRST_PSEUDO_REGISTER | |
984 | && (firstr < FIRST_PSEUDO_REGISTER | |
b1f21e0a MM |
985 | || ((uid_cuid[REGNO_LAST_UID (new)] > cse_basic_block_end |
986 | || (uid_cuid[REGNO_FIRST_UID (new)] | |
7afe21cc | 987 | < cse_basic_block_start)) |
b1f21e0a MM |
988 | && (uid_cuid[REGNO_LAST_UID (new)] |
989 | > uid_cuid[REGNO_LAST_UID (firstr)])))))) | |
7afe21cc RK |
990 | { |
991 | reg_prev_eqv[firstr] = new; | |
992 | reg_next_eqv[new] = firstr; | |
993 | reg_prev_eqv[new] = -1; | |
994 | qty_first_reg[q] = new; | |
995 | } | |
996 | else | |
997 | { | |
998 | /* If NEW is a hard reg (known to be non-fixed), insert at end. | |
999 | Otherwise, insert before any non-fixed hard regs that are at the | |
1000 | end. Registers of class NO_REGS cannot be used as an | |
1001 | equivalent for anything. */ | |
1002 | while (lastr < FIRST_PSEUDO_REGISTER && reg_prev_eqv[lastr] >= 0 | |
1003 | && (REGNO_REG_CLASS (lastr) == NO_REGS || ! FIXED_REGNO_P (lastr)) | |
1004 | && new >= FIRST_PSEUDO_REGISTER) | |
1005 | lastr = reg_prev_eqv[lastr]; | |
1006 | reg_next_eqv[new] = reg_next_eqv[lastr]; | |
1007 | if (reg_next_eqv[lastr] >= 0) | |
1008 | reg_prev_eqv[reg_next_eqv[lastr]] = new; | |
1009 | else | |
1010 | qty_last_reg[q] = new; | |
1011 | reg_next_eqv[lastr] = new; | |
1012 | reg_prev_eqv[new] = lastr; | |
1013 | } | |
1014 | } | |
1015 | ||
1016 | /* Remove REG from its equivalence class. */ | |
1017 | ||
1018 | static void | |
1019 | delete_reg_equiv (reg) | |
1020 | register int reg; | |
1021 | { | |
30f72379 | 1022 | register int q = REG_QTY (reg); |
a4e262bc | 1023 | register int p, n; |
7afe21cc | 1024 | |
a4e262bc | 1025 | /* If invalid, do nothing. */ |
7afe21cc RK |
1026 | if (q == reg) |
1027 | return; | |
1028 | ||
a4e262bc RK |
1029 | p = reg_prev_eqv[reg]; |
1030 | n = reg_next_eqv[reg]; | |
1031 | ||
7afe21cc RK |
1032 | if (n != -1) |
1033 | reg_prev_eqv[n] = p; | |
1034 | else | |
1035 | qty_last_reg[q] = p; | |
1036 | if (p != -1) | |
1037 | reg_next_eqv[p] = n; | |
1038 | else | |
1039 | qty_first_reg[q] = n; | |
1040 | ||
30f72379 | 1041 | REG_QTY (reg) = reg; |
7afe21cc RK |
1042 | } |
1043 | ||
1044 | /* Remove any invalid expressions from the hash table | |
1045 | that refer to any of the registers contained in expression X. | |
1046 | ||
1047 | Make sure that newly inserted references to those registers | |
1048 | as subexpressions will be considered valid. | |
1049 | ||
1050 | mention_regs is not called when a register itself | |
1051 | is being stored in the table. | |
1052 | ||
1053 | Return 1 if we have done something that may have changed the hash code | |
1054 | of X. */ | |
1055 | ||
1056 | static int | |
1057 | mention_regs (x) | |
1058 | rtx x; | |
1059 | { | |
1060 | register enum rtx_code code; | |
1061 | register int i, j; | |
1062 | register char *fmt; | |
1063 | register int changed = 0; | |
1064 | ||
1065 | if (x == 0) | |
e5f6a288 | 1066 | return 0; |
7afe21cc RK |
1067 | |
1068 | code = GET_CODE (x); | |
1069 | if (code == REG) | |
1070 | { | |
1071 | register int regno = REGNO (x); | |
1072 | register int endregno | |
1073 | = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1 | |
1074 | : HARD_REGNO_NREGS (regno, GET_MODE (x))); | |
1075 | int i; | |
1076 | ||
1077 | for (i = regno; i < endregno; i++) | |
1078 | { | |
30f72379 | 1079 | if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i)) |
7afe21cc RK |
1080 | remove_invalid_refs (i); |
1081 | ||
30f72379 | 1082 | REG_IN_TABLE (i) = REG_TICK (i); |
7afe21cc RK |
1083 | } |
1084 | ||
1085 | return 0; | |
1086 | } | |
1087 | ||
34c73909 R |
1088 | /* If this is a SUBREG, we don't want to discard other SUBREGs of the same |
1089 | pseudo if they don't use overlapping words. We handle only pseudos | |
1090 | here for simplicity. */ | |
1091 | if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == REG | |
1092 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER) | |
1093 | { | |
1094 | int i = REGNO (SUBREG_REG (x)); | |
1095 | ||
30f72379 | 1096 | if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i)) |
34c73909 R |
1097 | { |
1098 | /* If reg_tick has been incremented more than once since | |
1099 | reg_in_table was last set, that means that the entire | |
1100 | register has been set before, so discard anything memorized | |
1101 | for the entrire register, including all SUBREG expressions. */ | |
30f72379 | 1102 | if (REG_IN_TABLE (i) != REG_TICK (i) - 1) |
34c73909 R |
1103 | remove_invalid_refs (i); |
1104 | else | |
1105 | remove_invalid_subreg_refs (i, SUBREG_WORD (x), GET_MODE (x)); | |
1106 | } | |
1107 | ||
30f72379 | 1108 | REG_IN_TABLE (i) = REG_TICK (i); |
34c73909 R |
1109 | return 0; |
1110 | } | |
1111 | ||
7afe21cc RK |
1112 | /* If X is a comparison or a COMPARE and either operand is a register |
1113 | that does not have a quantity, give it one. This is so that a later | |
1114 | call to record_jump_equiv won't cause X to be assigned a different | |
1115 | hash code and not found in the table after that call. | |
1116 | ||
1117 | It is not necessary to do this here, since rehash_using_reg can | |
1118 | fix up the table later, but doing this here eliminates the need to | |
1119 | call that expensive function in the most common case where the only | |
1120 | use of the register is in the comparison. */ | |
1121 | ||
1122 | if (code == COMPARE || GET_RTX_CLASS (code) == '<') | |
1123 | { | |
1124 | if (GET_CODE (XEXP (x, 0)) == REG | |
1125 | && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 0)))) | |
906c4e36 | 1126 | if (insert_regs (XEXP (x, 0), NULL_PTR, 0)) |
7afe21cc RK |
1127 | { |
1128 | rehash_using_reg (XEXP (x, 0)); | |
1129 | changed = 1; | |
1130 | } | |
1131 | ||
1132 | if (GET_CODE (XEXP (x, 1)) == REG | |
1133 | && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 1)))) | |
906c4e36 | 1134 | if (insert_regs (XEXP (x, 1), NULL_PTR, 0)) |
7afe21cc RK |
1135 | { |
1136 | rehash_using_reg (XEXP (x, 1)); | |
1137 | changed = 1; | |
1138 | } | |
1139 | } | |
1140 | ||
1141 | fmt = GET_RTX_FORMAT (code); | |
1142 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1143 | if (fmt[i] == 'e') | |
1144 | changed |= mention_regs (XEXP (x, i)); | |
1145 | else if (fmt[i] == 'E') | |
1146 | for (j = 0; j < XVECLEN (x, i); j++) | |
1147 | changed |= mention_regs (XVECEXP (x, i, j)); | |
1148 | ||
1149 | return changed; | |
1150 | } | |
1151 | ||
1152 | /* Update the register quantities for inserting X into the hash table | |
1153 | with a value equivalent to CLASSP. | |
1154 | (If the class does not contain a REG, it is irrelevant.) | |
1155 | If MODIFIED is nonzero, X is a destination; it is being modified. | |
1156 | Note that delete_reg_equiv should be called on a register | |
1157 | before insert_regs is done on that register with MODIFIED != 0. | |
1158 | ||
1159 | Nonzero value means that elements of reg_qty have changed | |
1160 | so X's hash code may be different. */ | |
1161 | ||
1162 | static int | |
1163 | insert_regs (x, classp, modified) | |
1164 | rtx x; | |
1165 | struct table_elt *classp; | |
1166 | int modified; | |
1167 | { | |
1168 | if (GET_CODE (x) == REG) | |
1169 | { | |
1170 | register int regno = REGNO (x); | |
1171 | ||
1ff0c00d RK |
1172 | /* If REGNO is in the equivalence table already but is of the |
1173 | wrong mode for that equivalence, don't do anything here. */ | |
1174 | ||
1175 | if (REGNO_QTY_VALID_P (regno) | |
30f72379 | 1176 | && qty_mode[REG_QTY (regno)] != GET_MODE (x)) |
1ff0c00d RK |
1177 | return 0; |
1178 | ||
1179 | if (modified || ! REGNO_QTY_VALID_P (regno)) | |
7afe21cc RK |
1180 | { |
1181 | if (classp) | |
1182 | for (classp = classp->first_same_value; | |
1183 | classp != 0; | |
1184 | classp = classp->next_same_value) | |
1185 | if (GET_CODE (classp->exp) == REG | |
1186 | && GET_MODE (classp->exp) == GET_MODE (x)) | |
1187 | { | |
1188 | make_regs_eqv (regno, REGNO (classp->exp)); | |
1189 | return 1; | |
1190 | } | |
1191 | ||
1192 | make_new_qty (regno); | |
30f72379 | 1193 | qty_mode[REG_QTY (regno)] = GET_MODE (x); |
7afe21cc RK |
1194 | return 1; |
1195 | } | |
cdf4112f TG |
1196 | |
1197 | return 0; | |
7afe21cc | 1198 | } |
c610adec RK |
1199 | |
1200 | /* If X is a SUBREG, we will likely be inserting the inner register in the | |
1201 | table. If that register doesn't have an assigned quantity number at | |
1202 | this point but does later, the insertion that we will be doing now will | |
1203 | not be accessible because its hash code will have changed. So assign | |
1204 | a quantity number now. */ | |
1205 | ||
1206 | else if (GET_CODE (x) == SUBREG && GET_CODE (SUBREG_REG (x)) == REG | |
1207 | && ! REGNO_QTY_VALID_P (REGNO (SUBREG_REG (x)))) | |
1208 | { | |
34c73909 R |
1209 | int regno = REGNO (SUBREG_REG (x)); |
1210 | ||
906c4e36 | 1211 | insert_regs (SUBREG_REG (x), NULL_PTR, 0); |
34c73909 R |
1212 | /* Mention_regs checks if REG_TICK is exactly one larger than |
1213 | REG_IN_TABLE to find out if there was only a single preceding | |
1214 | invalidation - for the SUBREG - or another one, which would be | |
1215 | for the full register. Since we don't invalidate the SUBREG | |
1216 | here first, we might have to bump up REG_TICK so that mention_regs | |
1217 | will do the right thing. */ | |
30f72379 MM |
1218 | if (REG_IN_TABLE (regno) >= 0 |
1219 | && REG_TICK (regno) == REG_IN_TABLE (regno) + 1) | |
1220 | REG_TICK (regno)++; | |
34c73909 | 1221 | mention_regs (x); |
c610adec RK |
1222 | return 1; |
1223 | } | |
7afe21cc RK |
1224 | else |
1225 | return mention_regs (x); | |
1226 | } | |
1227 | \f | |
1228 | /* Look in or update the hash table. */ | |
1229 | ||
1230 | /* Put the element ELT on the list of free elements. */ | |
1231 | ||
1232 | static void | |
1233 | free_element (elt) | |
1234 | struct table_elt *elt; | |
1235 | { | |
1236 | elt->next_same_hash = free_element_chain; | |
1237 | free_element_chain = elt; | |
1238 | } | |
1239 | ||
1240 | /* Return an element that is free for use. */ | |
1241 | ||
1242 | static struct table_elt * | |
1243 | get_element () | |
1244 | { | |
1245 | struct table_elt *elt = free_element_chain; | |
1246 | if (elt) | |
1247 | { | |
1248 | free_element_chain = elt->next_same_hash; | |
1249 | return elt; | |
1250 | } | |
1251 | n_elements_made++; | |
1252 | return (struct table_elt *) oballoc (sizeof (struct table_elt)); | |
1253 | } | |
1254 | ||
1255 | /* Remove table element ELT from use in the table. | |
1256 | HASH is its hash code, made using the HASH macro. | |
1257 | It's an argument because often that is known in advance | |
1258 | and we save much time not recomputing it. */ | |
1259 | ||
1260 | static void | |
1261 | remove_from_table (elt, hash) | |
1262 | register struct table_elt *elt; | |
2197a88a | 1263 | unsigned hash; |
7afe21cc RK |
1264 | { |
1265 | if (elt == 0) | |
1266 | return; | |
1267 | ||
1268 | /* Mark this element as removed. See cse_insn. */ | |
1269 | elt->first_same_value = 0; | |
1270 | ||
1271 | /* Remove the table element from its equivalence class. */ | |
1272 | ||
1273 | { | |
1274 | register struct table_elt *prev = elt->prev_same_value; | |
1275 | register struct table_elt *next = elt->next_same_value; | |
1276 | ||
1277 | if (next) next->prev_same_value = prev; | |
1278 | ||
1279 | if (prev) | |
1280 | prev->next_same_value = next; | |
1281 | else | |
1282 | { | |
1283 | register struct table_elt *newfirst = next; | |
1284 | while (next) | |
1285 | { | |
1286 | next->first_same_value = newfirst; | |
1287 | next = next->next_same_value; | |
1288 | } | |
1289 | } | |
1290 | } | |
1291 | ||
1292 | /* Remove the table element from its hash bucket. */ | |
1293 | ||
1294 | { | |
1295 | register struct table_elt *prev = elt->prev_same_hash; | |
1296 | register struct table_elt *next = elt->next_same_hash; | |
1297 | ||
1298 | if (next) next->prev_same_hash = prev; | |
1299 | ||
1300 | if (prev) | |
1301 | prev->next_same_hash = next; | |
1302 | else if (table[hash] == elt) | |
1303 | table[hash] = next; | |
1304 | else | |
1305 | { | |
1306 | /* This entry is not in the proper hash bucket. This can happen | |
1307 | when two classes were merged by `merge_equiv_classes'. Search | |
1308 | for the hash bucket that it heads. This happens only very | |
1309 | rarely, so the cost is acceptable. */ | |
1310 | for (hash = 0; hash < NBUCKETS; hash++) | |
1311 | if (table[hash] == elt) | |
1312 | table[hash] = next; | |
1313 | } | |
1314 | } | |
1315 | ||
1316 | /* Remove the table element from its related-value circular chain. */ | |
1317 | ||
1318 | if (elt->related_value != 0 && elt->related_value != elt) | |
1319 | { | |
1320 | register struct table_elt *p = elt->related_value; | |
1321 | while (p->related_value != elt) | |
1322 | p = p->related_value; | |
1323 | p->related_value = elt->related_value; | |
1324 | if (p->related_value == p) | |
1325 | p->related_value = 0; | |
1326 | } | |
1327 | ||
1328 | free_element (elt); | |
1329 | } | |
1330 | ||
1331 | /* Look up X in the hash table and return its table element, | |
1332 | or 0 if X is not in the table. | |
1333 | ||
1334 | MODE is the machine-mode of X, or if X is an integer constant | |
1335 | with VOIDmode then MODE is the mode with which X will be used. | |
1336 | ||
1337 | Here we are satisfied to find an expression whose tree structure | |
1338 | looks like X. */ | |
1339 | ||
1340 | static struct table_elt * | |
1341 | lookup (x, hash, mode) | |
1342 | rtx x; | |
2197a88a | 1343 | unsigned hash; |
7afe21cc RK |
1344 | enum machine_mode mode; |
1345 | { | |
1346 | register struct table_elt *p; | |
1347 | ||
1348 | for (p = table[hash]; p; p = p->next_same_hash) | |
1349 | if (mode == p->mode && ((x == p->exp && GET_CODE (x) == REG) | |
1350 | || exp_equiv_p (x, p->exp, GET_CODE (x) != REG, 0))) | |
1351 | return p; | |
1352 | ||
1353 | return 0; | |
1354 | } | |
1355 | ||
1356 | /* Like `lookup' but don't care whether the table element uses invalid regs. | |
1357 | Also ignore discrepancies in the machine mode of a register. */ | |
1358 | ||
1359 | static struct table_elt * | |
1360 | lookup_for_remove (x, hash, mode) | |
1361 | rtx x; | |
2197a88a | 1362 | unsigned hash; |
7afe21cc RK |
1363 | enum machine_mode mode; |
1364 | { | |
1365 | register struct table_elt *p; | |
1366 | ||
1367 | if (GET_CODE (x) == REG) | |
1368 | { | |
1369 | int regno = REGNO (x); | |
1370 | /* Don't check the machine mode when comparing registers; | |
1371 | invalidating (REG:SI 0) also invalidates (REG:DF 0). */ | |
1372 | for (p = table[hash]; p; p = p->next_same_hash) | |
1373 | if (GET_CODE (p->exp) == REG | |
1374 | && REGNO (p->exp) == regno) | |
1375 | return p; | |
1376 | } | |
1377 | else | |
1378 | { | |
1379 | for (p = table[hash]; p; p = p->next_same_hash) | |
1380 | if (mode == p->mode && (x == p->exp || exp_equiv_p (x, p->exp, 0, 0))) | |
1381 | return p; | |
1382 | } | |
1383 | ||
1384 | return 0; | |
1385 | } | |
1386 | ||
1387 | /* Look for an expression equivalent to X and with code CODE. | |
1388 | If one is found, return that expression. */ | |
1389 | ||
1390 | static rtx | |
1391 | lookup_as_function (x, code) | |
1392 | rtx x; | |
1393 | enum rtx_code code; | |
1394 | { | |
1395 | register struct table_elt *p = lookup (x, safe_hash (x, VOIDmode) % NBUCKETS, | |
1396 | GET_MODE (x)); | |
34c73909 R |
1397 | /* If we are looking for a CONST_INT, the mode doesn't really matter, as |
1398 | long as we are narrowing. So if we looked in vain for a mode narrower | |
1399 | than word_mode before, look for word_mode now. */ | |
1400 | if (p == 0 && code == CONST_INT | |
1401 | && GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (word_mode)) | |
1402 | { | |
1403 | x = copy_rtx (x); | |
1404 | PUT_MODE (x, word_mode); | |
1405 | p = lookup (x, safe_hash (x, VOIDmode) % NBUCKETS, word_mode); | |
1406 | } | |
1407 | ||
7afe21cc RK |
1408 | if (p == 0) |
1409 | return 0; | |
1410 | ||
1411 | for (p = p->first_same_value; p; p = p->next_same_value) | |
1412 | { | |
1413 | if (GET_CODE (p->exp) == code | |
1414 | /* Make sure this is a valid entry in the table. */ | |
1415 | && exp_equiv_p (p->exp, p->exp, 1, 0)) | |
1416 | return p->exp; | |
1417 | } | |
1418 | ||
1419 | return 0; | |
1420 | } | |
1421 | ||
1422 | /* Insert X in the hash table, assuming HASH is its hash code | |
1423 | and CLASSP is an element of the class it should go in | |
1424 | (or 0 if a new class should be made). | |
1425 | It is inserted at the proper position to keep the class in | |
1426 | the order cheapest first. | |
1427 | ||
1428 | MODE is the machine-mode of X, or if X is an integer constant | |
1429 | with VOIDmode then MODE is the mode with which X will be used. | |
1430 | ||
1431 | For elements of equal cheapness, the most recent one | |
1432 | goes in front, except that the first element in the list | |
1433 | remains first unless a cheaper element is added. The order of | |
1434 | pseudo-registers does not matter, as canon_reg will be called to | |
830a38ee | 1435 | find the cheapest when a register is retrieved from the table. |
7afe21cc RK |
1436 | |
1437 | The in_memory field in the hash table element is set to 0. | |
1438 | The caller must set it nonzero if appropriate. | |
1439 | ||
1440 | You should call insert_regs (X, CLASSP, MODIFY) before calling here, | |
1441 | and if insert_regs returns a nonzero value | |
1442 | you must then recompute its hash code before calling here. | |
1443 | ||
1444 | If necessary, update table showing constant values of quantities. */ | |
1445 | ||
1446 | #define CHEAPER(X,Y) ((X)->cost < (Y)->cost) | |
1447 | ||
1448 | static struct table_elt * | |
1449 | insert (x, classp, hash, mode) | |
1450 | register rtx x; | |
1451 | register struct table_elt *classp; | |
2197a88a | 1452 | unsigned hash; |
7afe21cc RK |
1453 | enum machine_mode mode; |
1454 | { | |
1455 | register struct table_elt *elt; | |
1456 | ||
1457 | /* If X is a register and we haven't made a quantity for it, | |
1458 | something is wrong. */ | |
1459 | if (GET_CODE (x) == REG && ! REGNO_QTY_VALID_P (REGNO (x))) | |
1460 | abort (); | |
1461 | ||
1462 | /* If X is a hard register, show it is being put in the table. */ | |
1463 | if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER) | |
1464 | { | |
1465 | int regno = REGNO (x); | |
1466 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
1467 | int i; | |
1468 | ||
1469 | for (i = regno; i < endregno; i++) | |
1470 | SET_HARD_REG_BIT (hard_regs_in_table, i); | |
1471 | } | |
1472 | ||
a5dfb4ee | 1473 | /* If X is a label, show we recorded it. */ |
970c9ace RK |
1474 | if (GET_CODE (x) == LABEL_REF |
1475 | || (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == PLUS | |
1476 | && GET_CODE (XEXP (XEXP (x, 0), 0)) == LABEL_REF)) | |
a5dfb4ee | 1477 | recorded_label_ref = 1; |
7afe21cc RK |
1478 | |
1479 | /* Put an element for X into the right hash bucket. */ | |
1480 | ||
1481 | elt = get_element (); | |
1482 | elt->exp = x; | |
1483 | elt->cost = COST (x); | |
1484 | elt->next_same_value = 0; | |
1485 | elt->prev_same_value = 0; | |
1486 | elt->next_same_hash = table[hash]; | |
1487 | elt->prev_same_hash = 0; | |
1488 | elt->related_value = 0; | |
1489 | elt->in_memory = 0; | |
1490 | elt->mode = mode; | |
1491 | elt->is_const = (CONSTANT_P (x) | |
1492 | /* GNU C++ takes advantage of this for `this' | |
1493 | (and other const values). */ | |
1494 | || (RTX_UNCHANGING_P (x) | |
1495 | && GET_CODE (x) == REG | |
1496 | && REGNO (x) >= FIRST_PSEUDO_REGISTER) | |
1497 | || FIXED_BASE_PLUS_P (x)); | |
1498 | ||
1499 | if (table[hash]) | |
1500 | table[hash]->prev_same_hash = elt; | |
1501 | table[hash] = elt; | |
1502 | ||
1503 | /* Put it into the proper value-class. */ | |
1504 | if (classp) | |
1505 | { | |
1506 | classp = classp->first_same_value; | |
1507 | if (CHEAPER (elt, classp)) | |
1508 | /* Insert at the head of the class */ | |
1509 | { | |
1510 | register struct table_elt *p; | |
1511 | elt->next_same_value = classp; | |
1512 | classp->prev_same_value = elt; | |
1513 | elt->first_same_value = elt; | |
1514 | ||
1515 | for (p = classp; p; p = p->next_same_value) | |
1516 | p->first_same_value = elt; | |
1517 | } | |
1518 | else | |
1519 | { | |
1520 | /* Insert not at head of the class. */ | |
1521 | /* Put it after the last element cheaper than X. */ | |
1522 | register struct table_elt *p, *next; | |
1523 | for (p = classp; (next = p->next_same_value) && CHEAPER (next, elt); | |
1524 | p = next); | |
1525 | /* Put it after P and before NEXT. */ | |
1526 | elt->next_same_value = next; | |
1527 | if (next) | |
1528 | next->prev_same_value = elt; | |
1529 | elt->prev_same_value = p; | |
1530 | p->next_same_value = elt; | |
1531 | elt->first_same_value = classp; | |
1532 | } | |
1533 | } | |
1534 | else | |
1535 | elt->first_same_value = elt; | |
1536 | ||
1537 | /* If this is a constant being set equivalent to a register or a register | |
1538 | being set equivalent to a constant, note the constant equivalence. | |
1539 | ||
1540 | If this is a constant, it cannot be equivalent to a different constant, | |
1541 | and a constant is the only thing that can be cheaper than a register. So | |
1542 | we know the register is the head of the class (before the constant was | |
1543 | inserted). | |
1544 | ||
1545 | If this is a register that is not already known equivalent to a | |
1546 | constant, we must check the entire class. | |
1547 | ||
1548 | If this is a register that is already known equivalent to an insn, | |
1549 | update `qty_const_insn' to show that `this_insn' is the latest | |
1550 | insn making that quantity equivalent to the constant. */ | |
1551 | ||
f353588a RK |
1552 | if (elt->is_const && classp && GET_CODE (classp->exp) == REG |
1553 | && GET_CODE (x) != REG) | |
7afe21cc | 1554 | { |
30f72379 MM |
1555 | qty_const[REG_QTY (REGNO (classp->exp))] |
1556 | = gen_lowpart_if_possible (qty_mode[REG_QTY (REGNO (classp->exp))], x); | |
1557 | qty_const_insn[REG_QTY (REGNO (classp->exp))] = this_insn; | |
7afe21cc RK |
1558 | } |
1559 | ||
30f72379 | 1560 | else if (GET_CODE (x) == REG && classp && ! qty_const[REG_QTY (REGNO (x))] |
f353588a | 1561 | && ! elt->is_const) |
7afe21cc RK |
1562 | { |
1563 | register struct table_elt *p; | |
1564 | ||
1565 | for (p = classp; p != 0; p = p->next_same_value) | |
1566 | { | |
f353588a | 1567 | if (p->is_const && GET_CODE (p->exp) != REG) |
7afe21cc | 1568 | { |
30f72379 | 1569 | qty_const[REG_QTY (REGNO (x))] |
7afe21cc | 1570 | = gen_lowpart_if_possible (GET_MODE (x), p->exp); |
30f72379 | 1571 | qty_const_insn[REG_QTY (REGNO (x))] = this_insn; |
7afe21cc RK |
1572 | break; |
1573 | } | |
1574 | } | |
1575 | } | |
1576 | ||
30f72379 MM |
1577 | else if (GET_CODE (x) == REG && qty_const[REG_QTY (REGNO (x))] |
1578 | && GET_MODE (x) == qty_mode[REG_QTY (REGNO (x))]) | |
1579 | qty_const_insn[REG_QTY (REGNO (x))] = this_insn; | |
7afe21cc RK |
1580 | |
1581 | /* If this is a constant with symbolic value, | |
1582 | and it has a term with an explicit integer value, | |
1583 | link it up with related expressions. */ | |
1584 | if (GET_CODE (x) == CONST) | |
1585 | { | |
1586 | rtx subexp = get_related_value (x); | |
2197a88a | 1587 | unsigned subhash; |
7afe21cc RK |
1588 | struct table_elt *subelt, *subelt_prev; |
1589 | ||
1590 | if (subexp != 0) | |
1591 | { | |
1592 | /* Get the integer-free subexpression in the hash table. */ | |
1593 | subhash = safe_hash (subexp, mode) % NBUCKETS; | |
1594 | subelt = lookup (subexp, subhash, mode); | |
1595 | if (subelt == 0) | |
906c4e36 | 1596 | subelt = insert (subexp, NULL_PTR, subhash, mode); |
7afe21cc RK |
1597 | /* Initialize SUBELT's circular chain if it has none. */ |
1598 | if (subelt->related_value == 0) | |
1599 | subelt->related_value = subelt; | |
1600 | /* Find the element in the circular chain that precedes SUBELT. */ | |
1601 | subelt_prev = subelt; | |
1602 | while (subelt_prev->related_value != subelt) | |
1603 | subelt_prev = subelt_prev->related_value; | |
1604 | /* Put new ELT into SUBELT's circular chain just before SUBELT. | |
1605 | This way the element that follows SUBELT is the oldest one. */ | |
1606 | elt->related_value = subelt_prev->related_value; | |
1607 | subelt_prev->related_value = elt; | |
1608 | } | |
1609 | } | |
1610 | ||
1611 | return elt; | |
1612 | } | |
1613 | \f | |
1614 | /* Given two equivalence classes, CLASS1 and CLASS2, put all the entries from | |
1615 | CLASS2 into CLASS1. This is done when we have reached an insn which makes | |
1616 | the two classes equivalent. | |
1617 | ||
1618 | CLASS1 will be the surviving class; CLASS2 should not be used after this | |
1619 | call. | |
1620 | ||
1621 | Any invalid entries in CLASS2 will not be copied. */ | |
1622 | ||
1623 | static void | |
1624 | merge_equiv_classes (class1, class2) | |
1625 | struct table_elt *class1, *class2; | |
1626 | { | |
1627 | struct table_elt *elt, *next, *new; | |
1628 | ||
1629 | /* Ensure we start with the head of the classes. */ | |
1630 | class1 = class1->first_same_value; | |
1631 | class2 = class2->first_same_value; | |
1632 | ||
1633 | /* If they were already equal, forget it. */ | |
1634 | if (class1 == class2) | |
1635 | return; | |
1636 | ||
1637 | for (elt = class2; elt; elt = next) | |
1638 | { | |
2197a88a | 1639 | unsigned hash; |
7afe21cc RK |
1640 | rtx exp = elt->exp; |
1641 | enum machine_mode mode = elt->mode; | |
1642 | ||
1643 | next = elt->next_same_value; | |
1644 | ||
1645 | /* Remove old entry, make a new one in CLASS1's class. | |
1646 | Don't do this for invalid entries as we cannot find their | |
0f41302f | 1647 | hash code (it also isn't necessary). */ |
7afe21cc RK |
1648 | if (GET_CODE (exp) == REG || exp_equiv_p (exp, exp, 1, 0)) |
1649 | { | |
1650 | hash_arg_in_memory = 0; | |
1651 | hash_arg_in_struct = 0; | |
1652 | hash = HASH (exp, mode); | |
1653 | ||
1654 | if (GET_CODE (exp) == REG) | |
1655 | delete_reg_equiv (REGNO (exp)); | |
1656 | ||
1657 | remove_from_table (elt, hash); | |
1658 | ||
1659 | if (insert_regs (exp, class1, 0)) | |
8ae2b8f6 JW |
1660 | { |
1661 | rehash_using_reg (exp); | |
1662 | hash = HASH (exp, mode); | |
1663 | } | |
7afe21cc RK |
1664 | new = insert (exp, class1, hash, mode); |
1665 | new->in_memory = hash_arg_in_memory; | |
1666 | new->in_struct = hash_arg_in_struct; | |
1667 | } | |
1668 | } | |
1669 | } | |
1670 | \f | |
01e752d3 JL |
1671 | |
1672 | /* Flush the entire hash table. */ | |
1673 | ||
1674 | static void | |
1675 | flush_hash_table () | |
1676 | { | |
1677 | int i; | |
1678 | struct table_elt *p; | |
1679 | ||
1680 | for (i = 0; i < NBUCKETS; i++) | |
1681 | for (p = table[i]; p; p = table[i]) | |
1682 | { | |
1683 | /* Note that invalidate can remove elements | |
1684 | after P in the current hash chain. */ | |
1685 | if (GET_CODE (p->exp) == REG) | |
1686 | invalidate (p->exp, p->mode); | |
1687 | else | |
1688 | remove_from_table (p, i); | |
1689 | } | |
1690 | } | |
1691 | ||
1692 | ||
7afe21cc RK |
1693 | /* Remove from the hash table, or mark as invalid, |
1694 | all expressions whose values could be altered by storing in X. | |
1695 | X is a register, a subreg, or a memory reference with nonvarying address | |
1696 | (because, when a memory reference with a varying address is stored in, | |
1697 | all memory references are removed by invalidate_memory | |
1698 | so specific invalidation is superfluous). | |
bb4034b3 JW |
1699 | FULL_MODE, if not VOIDmode, indicates that this much should be invalidated |
1700 | instead of just the amount indicated by the mode of X. This is only used | |
1701 | for bitfield stores into memory. | |
7afe21cc RK |
1702 | |
1703 | A nonvarying address may be just a register or just | |
1704 | a symbol reference, or it may be either of those plus | |
1705 | a numeric offset. */ | |
1706 | ||
1707 | static void | |
bb4034b3 | 1708 | invalidate (x, full_mode) |
7afe21cc | 1709 | rtx x; |
bb4034b3 | 1710 | enum machine_mode full_mode; |
7afe21cc RK |
1711 | { |
1712 | register int i; | |
1713 | register struct table_elt *p; | |
7afe21cc RK |
1714 | |
1715 | /* If X is a register, dependencies on its contents | |
1716 | are recorded through the qty number mechanism. | |
1717 | Just change the qty number of the register, | |
1718 | mark it as invalid for expressions that refer to it, | |
1719 | and remove it itself. */ | |
1720 | ||
1721 | if (GET_CODE (x) == REG) | |
1722 | { | |
1723 | register int regno = REGNO (x); | |
2197a88a | 1724 | register unsigned hash = HASH (x, GET_MODE (x)); |
7afe21cc RK |
1725 | |
1726 | /* Remove REGNO from any quantity list it might be on and indicate | |
9ec36da5 | 1727 | that its value might have changed. If it is a pseudo, remove its |
7afe21cc RK |
1728 | entry from the hash table. |
1729 | ||
1730 | For a hard register, we do the first two actions above for any | |
1731 | additional hard registers corresponding to X. Then, if any of these | |
1732 | registers are in the table, we must remove any REG entries that | |
1733 | overlap these registers. */ | |
1734 | ||
1735 | delete_reg_equiv (regno); | |
30f72379 | 1736 | REG_TICK (regno)++; |
7afe21cc RK |
1737 | |
1738 | if (regno >= FIRST_PSEUDO_REGISTER) | |
85e4d983 RK |
1739 | { |
1740 | /* Because a register can be referenced in more than one mode, | |
1741 | we might have to remove more than one table entry. */ | |
1742 | ||
1743 | struct table_elt *elt; | |
1744 | ||
2d8b0f3a | 1745 | while ((elt = lookup_for_remove (x, hash, GET_MODE (x)))) |
85e4d983 RK |
1746 | remove_from_table (elt, hash); |
1747 | } | |
7afe21cc RK |
1748 | else |
1749 | { | |
54b1de55 RK |
1750 | HOST_WIDE_INT in_table |
1751 | = TEST_HARD_REG_BIT (hard_regs_in_table, regno); | |
7afe21cc RK |
1752 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (x)); |
1753 | int tregno, tendregno; | |
1754 | register struct table_elt *p, *next; | |
1755 | ||
1756 | CLEAR_HARD_REG_BIT (hard_regs_in_table, regno); | |
1757 | ||
1758 | for (i = regno + 1; i < endregno; i++) | |
1759 | { | |
1760 | in_table |= TEST_HARD_REG_BIT (hard_regs_in_table, i); | |
1761 | CLEAR_HARD_REG_BIT (hard_regs_in_table, i); | |
1762 | delete_reg_equiv (i); | |
30f72379 | 1763 | REG_TICK (i)++; |
7afe21cc RK |
1764 | } |
1765 | ||
1766 | if (in_table) | |
1767 | for (hash = 0; hash < NBUCKETS; hash++) | |
1768 | for (p = table[hash]; p; p = next) | |
1769 | { | |
1770 | next = p->next_same_hash; | |
1771 | ||
1772 | if (GET_CODE (p->exp) != REG | |
1773 | || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) | |
1774 | continue; | |
1775 | ||
1776 | tregno = REGNO (p->exp); | |
1777 | tendregno | |
1778 | = tregno + HARD_REGNO_NREGS (tregno, GET_MODE (p->exp)); | |
1779 | if (tendregno > regno && tregno < endregno) | |
925be47c | 1780 | remove_from_table (p, hash); |
7afe21cc RK |
1781 | } |
1782 | } | |
1783 | ||
1784 | return; | |
1785 | } | |
1786 | ||
1787 | if (GET_CODE (x) == SUBREG) | |
1788 | { | |
1789 | if (GET_CODE (SUBREG_REG (x)) != REG) | |
1790 | abort (); | |
bb4034b3 | 1791 | invalidate (SUBREG_REG (x), VOIDmode); |
7afe21cc RK |
1792 | return; |
1793 | } | |
1794 | ||
aac5cc16 RH |
1795 | /* If X is a parallel, invalidate all of its elements. */ |
1796 | ||
1797 | if (GET_CODE (x) == PARALLEL) | |
1798 | { | |
1799 | for (i = XVECLEN (x, 0) - 1; i >= 0 ; --i) | |
1800 | invalidate (XVECEXP (x, 0, i), VOIDmode); | |
1801 | return; | |
1802 | } | |
1803 | ||
1804 | /* If X is an expr_list, this is part of a disjoint return value; | |
1805 | extract the location in question ignoring the offset. */ | |
1806 | ||
1807 | if (GET_CODE (x) == EXPR_LIST) | |
1808 | { | |
1809 | invalidate (XEXP (x, 0), VOIDmode); | |
1810 | return; | |
1811 | } | |
1812 | ||
7afe21cc RK |
1813 | /* X is not a register; it must be a memory reference with |
1814 | a nonvarying address. Remove all hash table elements | |
1815 | that refer to overlapping pieces of memory. */ | |
1816 | ||
1817 | if (GET_CODE (x) != MEM) | |
1818 | abort (); | |
7afe21cc | 1819 | |
bb4034b3 JW |
1820 | if (full_mode == VOIDmode) |
1821 | full_mode = GET_MODE (x); | |
1822 | ||
7afe21cc RK |
1823 | for (i = 0; i < NBUCKETS; i++) |
1824 | { | |
1825 | register struct table_elt *next; | |
1826 | for (p = table[i]; p; p = next) | |
1827 | { | |
1828 | next = p->next_same_hash; | |
9ae8ffe7 JL |
1829 | /* Invalidate ASM_OPERANDS which reference memory (this is easier |
1830 | than checking all the aliases). */ | |
1831 | if (p->in_memory | |
1832 | && (GET_CODE (p->exp) != MEM | |
1833 | || true_dependence (x, full_mode, p->exp, cse_rtx_varies_p))) | |
7afe21cc RK |
1834 | remove_from_table (p, i); |
1835 | } | |
1836 | } | |
1837 | } | |
1838 | ||
1839 | /* Remove all expressions that refer to register REGNO, | |
1840 | since they are already invalid, and we are about to | |
1841 | mark that register valid again and don't want the old | |
1842 | expressions to reappear as valid. */ | |
1843 | ||
1844 | static void | |
1845 | remove_invalid_refs (regno) | |
1846 | int regno; | |
1847 | { | |
1848 | register int i; | |
1849 | register struct table_elt *p, *next; | |
1850 | ||
1851 | for (i = 0; i < NBUCKETS; i++) | |
1852 | for (p = table[i]; p; p = next) | |
1853 | { | |
1854 | next = p->next_same_hash; | |
1855 | if (GET_CODE (p->exp) != REG | |
906c4e36 | 1856 | && refers_to_regno_p (regno, regno + 1, p->exp, NULL_PTR)) |
7afe21cc RK |
1857 | remove_from_table (p, i); |
1858 | } | |
1859 | } | |
34c73909 R |
1860 | |
1861 | /* Likewise for a subreg with subreg_reg WORD and mode MODE. */ | |
1862 | static void | |
1863 | remove_invalid_subreg_refs (regno, word, mode) | |
1864 | int regno; | |
1865 | int word; | |
1866 | enum machine_mode mode; | |
1867 | { | |
1868 | register int i; | |
1869 | register struct table_elt *p, *next; | |
1870 | int end = word + (GET_MODE_SIZE (mode) - 1) / UNITS_PER_WORD; | |
1871 | ||
1872 | for (i = 0; i < NBUCKETS; i++) | |
1873 | for (p = table[i]; p; p = next) | |
1874 | { | |
1875 | rtx exp; | |
1876 | next = p->next_same_hash; | |
1877 | ||
1878 | exp = p->exp; | |
1879 | if (GET_CODE (p->exp) != REG | |
1880 | && (GET_CODE (exp) != SUBREG | |
1881 | || GET_CODE (SUBREG_REG (exp)) != REG | |
1882 | || REGNO (SUBREG_REG (exp)) != regno | |
1883 | || (((SUBREG_WORD (exp) | |
1884 | + (GET_MODE_SIZE (GET_MODE (exp)) - 1) / UNITS_PER_WORD) | |
1885 | >= word) | |
1886 | && SUBREG_WORD (exp) <= end)) | |
1887 | && refers_to_regno_p (regno, regno + 1, p->exp, NULL_PTR)) | |
1888 | remove_from_table (p, i); | |
1889 | } | |
1890 | } | |
7afe21cc RK |
1891 | \f |
1892 | /* Recompute the hash codes of any valid entries in the hash table that | |
1893 | reference X, if X is a register, or SUBREG_REG (X) if X is a SUBREG. | |
1894 | ||
1895 | This is called when we make a jump equivalence. */ | |
1896 | ||
1897 | static void | |
1898 | rehash_using_reg (x) | |
1899 | rtx x; | |
1900 | { | |
973838fd | 1901 | unsigned int i; |
7afe21cc | 1902 | struct table_elt *p, *next; |
2197a88a | 1903 | unsigned hash; |
7afe21cc RK |
1904 | |
1905 | if (GET_CODE (x) == SUBREG) | |
1906 | x = SUBREG_REG (x); | |
1907 | ||
1908 | /* If X is not a register or if the register is known not to be in any | |
1909 | valid entries in the table, we have no work to do. */ | |
1910 | ||
1911 | if (GET_CODE (x) != REG | |
30f72379 MM |
1912 | || REG_IN_TABLE (REGNO (x)) < 0 |
1913 | || REG_IN_TABLE (REGNO (x)) != REG_TICK (REGNO (x))) | |
7afe21cc RK |
1914 | return; |
1915 | ||
1916 | /* Scan all hash chains looking for valid entries that mention X. | |
1917 | If we find one and it is in the wrong hash chain, move it. We can skip | |
1918 | objects that are registers, since they are handled specially. */ | |
1919 | ||
1920 | for (i = 0; i < NBUCKETS; i++) | |
1921 | for (p = table[i]; p; p = next) | |
1922 | { | |
1923 | next = p->next_same_hash; | |
1924 | if (GET_CODE (p->exp) != REG && reg_mentioned_p (x, p->exp) | |
538b78e7 | 1925 | && exp_equiv_p (p->exp, p->exp, 1, 0) |
7afe21cc RK |
1926 | && i != (hash = safe_hash (p->exp, p->mode) % NBUCKETS)) |
1927 | { | |
1928 | if (p->next_same_hash) | |
1929 | p->next_same_hash->prev_same_hash = p->prev_same_hash; | |
1930 | ||
1931 | if (p->prev_same_hash) | |
1932 | p->prev_same_hash->next_same_hash = p->next_same_hash; | |
1933 | else | |
1934 | table[i] = p->next_same_hash; | |
1935 | ||
1936 | p->next_same_hash = table[hash]; | |
1937 | p->prev_same_hash = 0; | |
1938 | if (table[hash]) | |
1939 | table[hash]->prev_same_hash = p; | |
1940 | table[hash] = p; | |
1941 | } | |
1942 | } | |
1943 | } | |
1944 | \f | |
7afe21cc RK |
1945 | /* Remove from the hash table any expression that is a call-clobbered |
1946 | register. Also update their TICK values. */ | |
1947 | ||
1948 | static void | |
1949 | invalidate_for_call () | |
1950 | { | |
1951 | int regno, endregno; | |
1952 | int i; | |
2197a88a | 1953 | unsigned hash; |
7afe21cc RK |
1954 | struct table_elt *p, *next; |
1955 | int in_table = 0; | |
1956 | ||
1957 | /* Go through all the hard registers. For each that is clobbered in | |
1958 | a CALL_INSN, remove the register from quantity chains and update | |
1959 | reg_tick if defined. Also see if any of these registers is currently | |
1960 | in the table. */ | |
1961 | ||
1962 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
1963 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) | |
1964 | { | |
1965 | delete_reg_equiv (regno); | |
30f72379 MM |
1966 | if (REG_TICK (regno) >= 0) |
1967 | REG_TICK (regno)++; | |
7afe21cc | 1968 | |
0e227018 | 1969 | in_table |= (TEST_HARD_REG_BIT (hard_regs_in_table, regno) != 0); |
7afe21cc RK |
1970 | } |
1971 | ||
1972 | /* In the case where we have no call-clobbered hard registers in the | |
1973 | table, we are done. Otherwise, scan the table and remove any | |
1974 | entry that overlaps a call-clobbered register. */ | |
1975 | ||
1976 | if (in_table) | |
1977 | for (hash = 0; hash < NBUCKETS; hash++) | |
1978 | for (p = table[hash]; p; p = next) | |
1979 | { | |
1980 | next = p->next_same_hash; | |
1981 | ||
9ae8ffe7 JL |
1982 | if (p->in_memory) |
1983 | { | |
1984 | remove_from_table (p, hash); | |
1985 | continue; | |
1986 | } | |
1987 | ||
7afe21cc RK |
1988 | if (GET_CODE (p->exp) != REG |
1989 | || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) | |
1990 | continue; | |
1991 | ||
1992 | regno = REGNO (p->exp); | |
1993 | endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (p->exp)); | |
1994 | ||
1995 | for (i = regno; i < endregno; i++) | |
1996 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)) | |
1997 | { | |
1998 | remove_from_table (p, hash); | |
1999 | break; | |
2000 | } | |
2001 | } | |
2002 | } | |
2003 | \f | |
2004 | /* Given an expression X of type CONST, | |
2005 | and ELT which is its table entry (or 0 if it | |
2006 | is not in the hash table), | |
2007 | return an alternate expression for X as a register plus integer. | |
2008 | If none can be found, return 0. */ | |
2009 | ||
2010 | static rtx | |
2011 | use_related_value (x, elt) | |
2012 | rtx x; | |
2013 | struct table_elt *elt; | |
2014 | { | |
2015 | register struct table_elt *relt = 0; | |
2016 | register struct table_elt *p, *q; | |
906c4e36 | 2017 | HOST_WIDE_INT offset; |
7afe21cc RK |
2018 | |
2019 | /* First, is there anything related known? | |
2020 | If we have a table element, we can tell from that. | |
2021 | Otherwise, must look it up. */ | |
2022 | ||
2023 | if (elt != 0 && elt->related_value != 0) | |
2024 | relt = elt; | |
2025 | else if (elt == 0 && GET_CODE (x) == CONST) | |
2026 | { | |
2027 | rtx subexp = get_related_value (x); | |
2028 | if (subexp != 0) | |
2029 | relt = lookup (subexp, | |
2030 | safe_hash (subexp, GET_MODE (subexp)) % NBUCKETS, | |
2031 | GET_MODE (subexp)); | |
2032 | } | |
2033 | ||
2034 | if (relt == 0) | |
2035 | return 0; | |
2036 | ||
2037 | /* Search all related table entries for one that has an | |
2038 | equivalent register. */ | |
2039 | ||
2040 | p = relt; | |
2041 | while (1) | |
2042 | { | |
2043 | /* This loop is strange in that it is executed in two different cases. | |
2044 | The first is when X is already in the table. Then it is searching | |
2045 | the RELATED_VALUE list of X's class (RELT). The second case is when | |
2046 | X is not in the table. Then RELT points to a class for the related | |
2047 | value. | |
2048 | ||
2049 | Ensure that, whatever case we are in, that we ignore classes that have | |
2050 | the same value as X. */ | |
2051 | ||
2052 | if (rtx_equal_p (x, p->exp)) | |
2053 | q = 0; | |
2054 | else | |
2055 | for (q = p->first_same_value; q; q = q->next_same_value) | |
2056 | if (GET_CODE (q->exp) == REG) | |
2057 | break; | |
2058 | ||
2059 | if (q) | |
2060 | break; | |
2061 | ||
2062 | p = p->related_value; | |
2063 | ||
2064 | /* We went all the way around, so there is nothing to be found. | |
2065 | Alternatively, perhaps RELT was in the table for some other reason | |
2066 | and it has no related values recorded. */ | |
2067 | if (p == relt || p == 0) | |
2068 | break; | |
2069 | } | |
2070 | ||
2071 | if (q == 0) | |
2072 | return 0; | |
2073 | ||
2074 | offset = (get_integer_term (x) - get_integer_term (p->exp)); | |
2075 | /* Note: OFFSET may be 0 if P->xexp and X are related by commutativity. */ | |
2076 | return plus_constant (q->exp, offset); | |
2077 | } | |
2078 | \f | |
2079 | /* Hash an rtx. We are careful to make sure the value is never negative. | |
2080 | Equivalent registers hash identically. | |
2081 | MODE is used in hashing for CONST_INTs only; | |
2082 | otherwise the mode of X is used. | |
2083 | ||
2084 | Store 1 in do_not_record if any subexpression is volatile. | |
2085 | ||
2086 | Store 1 in hash_arg_in_memory if X contains a MEM rtx | |
2087 | which does not have the RTX_UNCHANGING_P bit set. | |
2088 | In this case, also store 1 in hash_arg_in_struct | |
2089 | if there is a MEM rtx which has the MEM_IN_STRUCT_P bit set. | |
2090 | ||
2091 | Note that cse_insn knows that the hash code of a MEM expression | |
2092 | is just (int) MEM plus the hash code of the address. */ | |
2093 | ||
2197a88a | 2094 | static unsigned |
7afe21cc RK |
2095 | canon_hash (x, mode) |
2096 | rtx x; | |
2097 | enum machine_mode mode; | |
2098 | { | |
2099 | register int i, j; | |
2197a88a | 2100 | register unsigned hash = 0; |
7afe21cc RK |
2101 | register enum rtx_code code; |
2102 | register char *fmt; | |
2103 | ||
2104 | /* repeat is used to turn tail-recursion into iteration. */ | |
2105 | repeat: | |
2106 | if (x == 0) | |
2107 | return hash; | |
2108 | ||
2109 | code = GET_CODE (x); | |
2110 | switch (code) | |
2111 | { | |
2112 | case REG: | |
2113 | { | |
2114 | register int regno = REGNO (x); | |
2115 | ||
2116 | /* On some machines, we can't record any non-fixed hard register, | |
2117 | because extending its life will cause reload problems. We | |
9a794e50 RH |
2118 | consider ap, fp, and sp to be fixed for this purpose. |
2119 | ||
2120 | We also consider CCmode registers to be fixed for this purpose; | |
2121 | failure to do so leads to failure to simplify 0<100 type of | |
2122 | conditionals. | |
2123 | ||
0f41302f | 2124 | On all machines, we can't record any global registers. */ |
7afe21cc RK |
2125 | |
2126 | if (regno < FIRST_PSEUDO_REGISTER | |
2127 | && (global_regs[regno] | |
f95182a4 ILT |
2128 | || (SMALL_REGISTER_CLASSES |
2129 | && ! fixed_regs[regno] | |
7afe21cc | 2130 | && regno != FRAME_POINTER_REGNUM |
8bc169f2 | 2131 | && regno != HARD_FRAME_POINTER_REGNUM |
7afe21cc | 2132 | && regno != ARG_POINTER_REGNUM |
9a794e50 RH |
2133 | && regno != STACK_POINTER_REGNUM |
2134 | && GET_MODE_CLASS (GET_MODE (x)) != MODE_CC))) | |
7afe21cc RK |
2135 | { |
2136 | do_not_record = 1; | |
2137 | return 0; | |
2138 | } | |
30f72379 | 2139 | hash += ((unsigned) REG << 7) + (unsigned) REG_QTY (regno); |
2197a88a | 2140 | return hash; |
7afe21cc RK |
2141 | } |
2142 | ||
34c73909 R |
2143 | /* We handle SUBREG of a REG specially because the underlying |
2144 | reg changes its hash value with every value change; we don't | |
2145 | want to have to forget unrelated subregs when one subreg changes. */ | |
2146 | case SUBREG: | |
2147 | { | |
2148 | if (GET_CODE (SUBREG_REG (x)) == REG) | |
2149 | { | |
2150 | hash += (((unsigned) SUBREG << 7) | |
2151 | + REGNO (SUBREG_REG (x)) + SUBREG_WORD (x)); | |
2152 | return hash; | |
2153 | } | |
2154 | break; | |
2155 | } | |
2156 | ||
7afe21cc | 2157 | case CONST_INT: |
2197a88a RK |
2158 | { |
2159 | unsigned HOST_WIDE_INT tem = INTVAL (x); | |
2160 | hash += ((unsigned) CONST_INT << 7) + (unsigned) mode + tem; | |
2161 | return hash; | |
2162 | } | |
7afe21cc RK |
2163 | |
2164 | case CONST_DOUBLE: | |
2165 | /* This is like the general case, except that it only counts | |
2166 | the integers representing the constant. */ | |
2197a88a | 2167 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
969c8517 RK |
2168 | if (GET_MODE (x) != VOIDmode) |
2169 | for (i = 2; i < GET_RTX_LENGTH (CONST_DOUBLE); i++) | |
2170 | { | |
2171 | unsigned tem = XINT (x, i); | |
2172 | hash += tem; | |
2173 | } | |
2174 | else | |
2175 | hash += ((unsigned) CONST_DOUBLE_LOW (x) | |
2176 | + (unsigned) CONST_DOUBLE_HIGH (x)); | |
7afe21cc RK |
2177 | return hash; |
2178 | ||
2179 | /* Assume there is only one rtx object for any given label. */ | |
2180 | case LABEL_REF: | |
3c543775 | 2181 | hash |
7bcac048 | 2182 | += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0); |
2197a88a | 2183 | return hash; |
7afe21cc RK |
2184 | |
2185 | case SYMBOL_REF: | |
3c543775 | 2186 | hash |
7bcac048 | 2187 | += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0); |
2197a88a | 2188 | return hash; |
7afe21cc RK |
2189 | |
2190 | case MEM: | |
2191 | if (MEM_VOLATILE_P (x)) | |
2192 | { | |
2193 | do_not_record = 1; | |
2194 | return 0; | |
2195 | } | |
9ad91d71 | 2196 | if (! RTX_UNCHANGING_P (x) || FIXED_BASE_PLUS_P (XEXP (x, 0))) |
7afe21cc RK |
2197 | { |
2198 | hash_arg_in_memory = 1; | |
2199 | if (MEM_IN_STRUCT_P (x)) hash_arg_in_struct = 1; | |
2200 | } | |
2201 | /* Now that we have already found this special case, | |
2202 | might as well speed it up as much as possible. */ | |
2197a88a | 2203 | hash += (unsigned) MEM; |
7afe21cc RK |
2204 | x = XEXP (x, 0); |
2205 | goto repeat; | |
2206 | ||
2207 | case PRE_DEC: | |
2208 | case PRE_INC: | |
2209 | case POST_DEC: | |
2210 | case POST_INC: | |
2211 | case PC: | |
2212 | case CC0: | |
2213 | case CALL: | |
2214 | case UNSPEC_VOLATILE: | |
2215 | do_not_record = 1; | |
2216 | return 0; | |
2217 | ||
2218 | case ASM_OPERANDS: | |
2219 | if (MEM_VOLATILE_P (x)) | |
2220 | { | |
2221 | do_not_record = 1; | |
2222 | return 0; | |
2223 | } | |
e9a25f70 JL |
2224 | break; |
2225 | ||
2226 | default: | |
2227 | break; | |
7afe21cc RK |
2228 | } |
2229 | ||
2230 | i = GET_RTX_LENGTH (code) - 1; | |
2197a88a | 2231 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
7afe21cc RK |
2232 | fmt = GET_RTX_FORMAT (code); |
2233 | for (; i >= 0; i--) | |
2234 | { | |
2235 | if (fmt[i] == 'e') | |
2236 | { | |
2237 | rtx tem = XEXP (x, i); | |
7afe21cc RK |
2238 | |
2239 | /* If we are about to do the last recursive call | |
2240 | needed at this level, change it into iteration. | |
2241 | This function is called enough to be worth it. */ | |
2242 | if (i == 0) | |
2243 | { | |
2244 | x = tem; | |
2245 | goto repeat; | |
2246 | } | |
2247 | hash += canon_hash (tem, 0); | |
2248 | } | |
2249 | else if (fmt[i] == 'E') | |
2250 | for (j = 0; j < XVECLEN (x, i); j++) | |
2251 | hash += canon_hash (XVECEXP (x, i, j), 0); | |
2252 | else if (fmt[i] == 's') | |
2253 | { | |
2197a88a | 2254 | register unsigned char *p = (unsigned char *) XSTR (x, i); |
7afe21cc RK |
2255 | if (p) |
2256 | while (*p) | |
2197a88a | 2257 | hash += *p++; |
7afe21cc RK |
2258 | } |
2259 | else if (fmt[i] == 'i') | |
2260 | { | |
2197a88a RK |
2261 | register unsigned tem = XINT (x, i); |
2262 | hash += tem; | |
7afe21cc | 2263 | } |
8f985ec4 | 2264 | else if (fmt[i] == '0' || fmt[i] == 't') |
e9a25f70 | 2265 | /* unused */; |
7afe21cc RK |
2266 | else |
2267 | abort (); | |
2268 | } | |
2269 | return hash; | |
2270 | } | |
2271 | ||
2272 | /* Like canon_hash but with no side effects. */ | |
2273 | ||
2197a88a | 2274 | static unsigned |
7afe21cc RK |
2275 | safe_hash (x, mode) |
2276 | rtx x; | |
2277 | enum machine_mode mode; | |
2278 | { | |
2279 | int save_do_not_record = do_not_record; | |
2280 | int save_hash_arg_in_memory = hash_arg_in_memory; | |
2281 | int save_hash_arg_in_struct = hash_arg_in_struct; | |
2197a88a | 2282 | unsigned hash = canon_hash (x, mode); |
7afe21cc RK |
2283 | hash_arg_in_memory = save_hash_arg_in_memory; |
2284 | hash_arg_in_struct = save_hash_arg_in_struct; | |
2285 | do_not_record = save_do_not_record; | |
2286 | return hash; | |
2287 | } | |
2288 | \f | |
2289 | /* Return 1 iff X and Y would canonicalize into the same thing, | |
2290 | without actually constructing the canonicalization of either one. | |
2291 | If VALIDATE is nonzero, | |
2292 | we assume X is an expression being processed from the rtl | |
2293 | and Y was found in the hash table. We check register refs | |
2294 | in Y for being marked as valid. | |
2295 | ||
2296 | If EQUAL_VALUES is nonzero, we allow a register to match a constant value | |
2297 | that is known to be in the register. Ordinarily, we don't allow them | |
2298 | to match, because letting them match would cause unpredictable results | |
2299 | in all the places that search a hash table chain for an equivalent | |
2300 | for a given value. A possible equivalent that has different structure | |
2301 | has its hash code computed from different data. Whether the hash code | |
38e01259 | 2302 | is the same as that of the given value is pure luck. */ |
7afe21cc RK |
2303 | |
2304 | static int | |
2305 | exp_equiv_p (x, y, validate, equal_values) | |
2306 | rtx x, y; | |
2307 | int validate; | |
2308 | int equal_values; | |
2309 | { | |
906c4e36 | 2310 | register int i, j; |
7afe21cc RK |
2311 | register enum rtx_code code; |
2312 | register char *fmt; | |
2313 | ||
2314 | /* Note: it is incorrect to assume an expression is equivalent to itself | |
2315 | if VALIDATE is nonzero. */ | |
2316 | if (x == y && !validate) | |
2317 | return 1; | |
2318 | if (x == 0 || y == 0) | |
2319 | return x == y; | |
2320 | ||
2321 | code = GET_CODE (x); | |
2322 | if (code != GET_CODE (y)) | |
2323 | { | |
2324 | if (!equal_values) | |
2325 | return 0; | |
2326 | ||
2327 | /* If X is a constant and Y is a register or vice versa, they may be | |
2328 | equivalent. We only have to validate if Y is a register. */ | |
2329 | if (CONSTANT_P (x) && GET_CODE (y) == REG | |
2330 | && REGNO_QTY_VALID_P (REGNO (y)) | |
30f72379 MM |
2331 | && GET_MODE (y) == qty_mode[REG_QTY (REGNO (y))] |
2332 | && rtx_equal_p (x, qty_const[REG_QTY (REGNO (y))]) | |
2333 | && (! validate || REG_IN_TABLE (REGNO (y)) == REG_TICK (REGNO (y)))) | |
7afe21cc RK |
2334 | return 1; |
2335 | ||
2336 | if (CONSTANT_P (y) && code == REG | |
2337 | && REGNO_QTY_VALID_P (REGNO (x)) | |
30f72379 MM |
2338 | && GET_MODE (x) == qty_mode[REG_QTY (REGNO (x))] |
2339 | && rtx_equal_p (y, qty_const[REG_QTY (REGNO (x))])) | |
7afe21cc RK |
2340 | return 1; |
2341 | ||
2342 | return 0; | |
2343 | } | |
2344 | ||
2345 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
2346 | if (GET_MODE (x) != GET_MODE (y)) | |
2347 | return 0; | |
2348 | ||
2349 | switch (code) | |
2350 | { | |
2351 | case PC: | |
2352 | case CC0: | |
2353 | return x == y; | |
2354 | ||
2355 | case CONST_INT: | |
58c8c593 | 2356 | return INTVAL (x) == INTVAL (y); |
7afe21cc RK |
2357 | |
2358 | case LABEL_REF: | |
7afe21cc RK |
2359 | return XEXP (x, 0) == XEXP (y, 0); |
2360 | ||
f54d4924 RK |
2361 | case SYMBOL_REF: |
2362 | return XSTR (x, 0) == XSTR (y, 0); | |
2363 | ||
7afe21cc RK |
2364 | case REG: |
2365 | { | |
2366 | int regno = REGNO (y); | |
2367 | int endregno | |
2368 | = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1 | |
2369 | : HARD_REGNO_NREGS (regno, GET_MODE (y))); | |
2370 | int i; | |
2371 | ||
2372 | /* If the quantities are not the same, the expressions are not | |
2373 | equivalent. If there are and we are not to validate, they | |
2374 | are equivalent. Otherwise, ensure all regs are up-to-date. */ | |
2375 | ||
30f72379 | 2376 | if (REG_QTY (REGNO (x)) != REG_QTY (regno)) |
7afe21cc RK |
2377 | return 0; |
2378 | ||
2379 | if (! validate) | |
2380 | return 1; | |
2381 | ||
2382 | for (i = regno; i < endregno; i++) | |
30f72379 | 2383 | if (REG_IN_TABLE (i) != REG_TICK (i)) |
7afe21cc RK |
2384 | return 0; |
2385 | ||
2386 | return 1; | |
2387 | } | |
2388 | ||
2389 | /* For commutative operations, check both orders. */ | |
2390 | case PLUS: | |
2391 | case MULT: | |
2392 | case AND: | |
2393 | case IOR: | |
2394 | case XOR: | |
2395 | case NE: | |
2396 | case EQ: | |
2397 | return ((exp_equiv_p (XEXP (x, 0), XEXP (y, 0), validate, equal_values) | |
2398 | && exp_equiv_p (XEXP (x, 1), XEXP (y, 1), | |
2399 | validate, equal_values)) | |
2400 | || (exp_equiv_p (XEXP (x, 0), XEXP (y, 1), | |
2401 | validate, equal_values) | |
2402 | && exp_equiv_p (XEXP (x, 1), XEXP (y, 0), | |
2403 | validate, equal_values))); | |
e9a25f70 JL |
2404 | |
2405 | default: | |
2406 | break; | |
7afe21cc RK |
2407 | } |
2408 | ||
2409 | /* Compare the elements. If any pair of corresponding elements | |
2410 | fail to match, return 0 for the whole things. */ | |
2411 | ||
2412 | fmt = GET_RTX_FORMAT (code); | |
2413 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2414 | { | |
906c4e36 | 2415 | switch (fmt[i]) |
7afe21cc | 2416 | { |
906c4e36 | 2417 | case 'e': |
7afe21cc RK |
2418 | if (! exp_equiv_p (XEXP (x, i), XEXP (y, i), validate, equal_values)) |
2419 | return 0; | |
906c4e36 RK |
2420 | break; |
2421 | ||
2422 | case 'E': | |
7afe21cc RK |
2423 | if (XVECLEN (x, i) != XVECLEN (y, i)) |
2424 | return 0; | |
2425 | for (j = 0; j < XVECLEN (x, i); j++) | |
2426 | if (! exp_equiv_p (XVECEXP (x, i, j), XVECEXP (y, i, j), | |
2427 | validate, equal_values)) | |
2428 | return 0; | |
906c4e36 RK |
2429 | break; |
2430 | ||
2431 | case 's': | |
7afe21cc RK |
2432 | if (strcmp (XSTR (x, i), XSTR (y, i))) |
2433 | return 0; | |
906c4e36 RK |
2434 | break; |
2435 | ||
2436 | case 'i': | |
7afe21cc RK |
2437 | if (XINT (x, i) != XINT (y, i)) |
2438 | return 0; | |
906c4e36 RK |
2439 | break; |
2440 | ||
2441 | case 'w': | |
2442 | if (XWINT (x, i) != XWINT (y, i)) | |
2443 | return 0; | |
2444 | break; | |
2445 | ||
2446 | case '0': | |
8f985ec4 | 2447 | case 't': |
906c4e36 RK |
2448 | break; |
2449 | ||
2450 | default: | |
2451 | abort (); | |
7afe21cc | 2452 | } |
906c4e36 RK |
2453 | } |
2454 | ||
7afe21cc RK |
2455 | return 1; |
2456 | } | |
2457 | \f | |
2458 | /* Return 1 iff any subexpression of X matches Y. | |
2459 | Here we do not require that X or Y be valid (for registers referred to) | |
2460 | for being in the hash table. */ | |
2461 | ||
6cd4575e | 2462 | static int |
7afe21cc RK |
2463 | refers_to_p (x, y) |
2464 | rtx x, y; | |
2465 | { | |
2466 | register int i; | |
2467 | register enum rtx_code code; | |
2468 | register char *fmt; | |
2469 | ||
2470 | repeat: | |
2471 | if (x == y) | |
2472 | return 1; | |
2473 | if (x == 0 || y == 0) | |
2474 | return 0; | |
2475 | ||
2476 | code = GET_CODE (x); | |
2477 | /* If X as a whole has the same code as Y, they may match. | |
2478 | If so, return 1. */ | |
2479 | if (code == GET_CODE (y)) | |
2480 | { | |
2481 | if (exp_equiv_p (x, y, 0, 1)) | |
2482 | return 1; | |
2483 | } | |
2484 | ||
2485 | /* X does not match, so try its subexpressions. */ | |
2486 | ||
2487 | fmt = GET_RTX_FORMAT (code); | |
2488 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2489 | if (fmt[i] == 'e') | |
2490 | { | |
2491 | if (i == 0) | |
2492 | { | |
2493 | x = XEXP (x, 0); | |
2494 | goto repeat; | |
2495 | } | |
2496 | else | |
2497 | if (refers_to_p (XEXP (x, i), y)) | |
2498 | return 1; | |
2499 | } | |
2500 | else if (fmt[i] == 'E') | |
2501 | { | |
2502 | int j; | |
2503 | for (j = 0; j < XVECLEN (x, i); j++) | |
2504 | if (refers_to_p (XVECEXP (x, i, j), y)) | |
2505 | return 1; | |
2506 | } | |
2507 | ||
2508 | return 0; | |
2509 | } | |
2510 | \f | |
f451db89 JL |
2511 | /* Given ADDR and SIZE (a memory address, and the size of the memory reference), |
2512 | set PBASE, PSTART, and PEND which correspond to the base of the address, | |
2513 | the starting offset, and ending offset respectively. | |
2514 | ||
bb4034b3 | 2515 | ADDR is known to be a nonvarying address. */ |
f451db89 | 2516 | |
bb4034b3 JW |
2517 | /* ??? Despite what the comments say, this function is in fact frequently |
2518 | passed varying addresses. This does not appear to cause any problems. */ | |
f451db89 JL |
2519 | |
2520 | static void | |
2521 | set_nonvarying_address_components (addr, size, pbase, pstart, pend) | |
2522 | rtx addr; | |
2523 | int size; | |
2524 | rtx *pbase; | |
6500fb43 | 2525 | HOST_WIDE_INT *pstart, *pend; |
f451db89 JL |
2526 | { |
2527 | rtx base; | |
c85663b1 | 2528 | HOST_WIDE_INT start, end; |
f451db89 JL |
2529 | |
2530 | base = addr; | |
2531 | start = 0; | |
2532 | end = 0; | |
2533 | ||
e5e809f4 JL |
2534 | if (flag_pic && GET_CODE (base) == PLUS |
2535 | && XEXP (base, 0) == pic_offset_table_rtx) | |
2536 | base = XEXP (base, 1); | |
2537 | ||
f451db89 JL |
2538 | /* Registers with nonvarying addresses usually have constant equivalents; |
2539 | but the frame pointer register is also possible. */ | |
2540 | if (GET_CODE (base) == REG | |
2541 | && qty_const != 0 | |
2542 | && REGNO_QTY_VALID_P (REGNO (base)) | |
30f72379 MM |
2543 | && qty_mode[REG_QTY (REGNO (base))] == GET_MODE (base) |
2544 | && qty_const[REG_QTY (REGNO (base))] != 0) | |
2545 | base = qty_const[REG_QTY (REGNO (base))]; | |
f451db89 JL |
2546 | else if (GET_CODE (base) == PLUS |
2547 | && GET_CODE (XEXP (base, 1)) == CONST_INT | |
2548 | && GET_CODE (XEXP (base, 0)) == REG | |
2549 | && qty_const != 0 | |
2550 | && REGNO_QTY_VALID_P (REGNO (XEXP (base, 0))) | |
30f72379 | 2551 | && (qty_mode[REG_QTY (REGNO (XEXP (base, 0)))] |
f451db89 | 2552 | == GET_MODE (XEXP (base, 0))) |
30f72379 | 2553 | && qty_const[REG_QTY (REGNO (XEXP (base, 0)))]) |
f451db89 JL |
2554 | { |
2555 | start = INTVAL (XEXP (base, 1)); | |
30f72379 | 2556 | base = qty_const[REG_QTY (REGNO (XEXP (base, 0)))]; |
f451db89 | 2557 | } |
9c6b0bae | 2558 | /* This can happen as the result of virtual register instantiation, |
abc95ed3 | 2559 | if the initial offset is too large to be a valid address. */ |
9c6b0bae RK |
2560 | else if (GET_CODE (base) == PLUS |
2561 | && GET_CODE (XEXP (base, 0)) == REG | |
2562 | && GET_CODE (XEXP (base, 1)) == REG | |
2563 | && qty_const != 0 | |
2564 | && REGNO_QTY_VALID_P (REGNO (XEXP (base, 0))) | |
30f72379 | 2565 | && (qty_mode[REG_QTY (REGNO (XEXP (base, 0)))] |
9c6b0bae | 2566 | == GET_MODE (XEXP (base, 0))) |
30f72379 | 2567 | && qty_const[REG_QTY (REGNO (XEXP (base, 0)))] |
9c6b0bae | 2568 | && REGNO_QTY_VALID_P (REGNO (XEXP (base, 1))) |
30f72379 | 2569 | && (qty_mode[REG_QTY (REGNO (XEXP (base, 1)))] |
9c6b0bae | 2570 | == GET_MODE (XEXP (base, 1))) |
30f72379 | 2571 | && qty_const[REG_QTY (REGNO (XEXP (base, 1)))]) |
9c6b0bae | 2572 | { |
30f72379 MM |
2573 | rtx tem = qty_const[REG_QTY (REGNO (XEXP (base, 1)))]; |
2574 | base = qty_const[REG_QTY (REGNO (XEXP (base, 0)))]; | |
9c6b0bae RK |
2575 | |
2576 | /* One of the two values must be a constant. */ | |
2577 | if (GET_CODE (base) != CONST_INT) | |
2578 | { | |
2579 | if (GET_CODE (tem) != CONST_INT) | |
2580 | abort (); | |
2581 | start = INTVAL (tem); | |
2582 | } | |
2583 | else | |
2584 | { | |
2585 | start = INTVAL (base); | |
2586 | base = tem; | |
2587 | } | |
2588 | } | |
f451db89 | 2589 | |
c85663b1 RK |
2590 | /* Handle everything that we can find inside an address that has been |
2591 | viewed as constant. */ | |
f451db89 | 2592 | |
c85663b1 | 2593 | while (1) |
f451db89 | 2594 | { |
c85663b1 RK |
2595 | /* If no part of this switch does a "continue", the code outside |
2596 | will exit this loop. */ | |
2597 | ||
2598 | switch (GET_CODE (base)) | |
2599 | { | |
2600 | case LO_SUM: | |
2601 | /* By definition, operand1 of a LO_SUM is the associated constant | |
2602 | address. Use the associated constant address as the base | |
2603 | instead. */ | |
2604 | base = XEXP (base, 1); | |
2605 | continue; | |
2606 | ||
2607 | case CONST: | |
2608 | /* Strip off CONST. */ | |
2609 | base = XEXP (base, 0); | |
2610 | continue; | |
2611 | ||
2612 | case PLUS: | |
2613 | if (GET_CODE (XEXP (base, 1)) == CONST_INT) | |
2614 | { | |
2615 | start += INTVAL (XEXP (base, 1)); | |
2616 | base = XEXP (base, 0); | |
2617 | continue; | |
2618 | } | |
2619 | break; | |
2620 | ||
2621 | case AND: | |
2622 | /* Handle the case of an AND which is the negative of a power of | |
2623 | two. This is used to represent unaligned memory operations. */ | |
2624 | if (GET_CODE (XEXP (base, 1)) == CONST_INT | |
2625 | && exact_log2 (- INTVAL (XEXP (base, 1))) > 0) | |
2626 | { | |
2627 | set_nonvarying_address_components (XEXP (base, 0), size, | |
2628 | pbase, pstart, pend); | |
2629 | ||
2630 | /* Assume the worst misalignment. START is affected, but not | |
2631 | END, so compensate but adjusting SIZE. Don't lose any | |
2632 | constant we already had. */ | |
2633 | ||
2634 | size = *pend - *pstart - INTVAL (XEXP (base, 1)) - 1; | |
89046535 RK |
2635 | start += *pstart + INTVAL (XEXP (base, 1)) + 1; |
2636 | end += *pend; | |
c85663b1 RK |
2637 | base = *pbase; |
2638 | } | |
2639 | break; | |
e9a25f70 JL |
2640 | |
2641 | default: | |
2642 | break; | |
c85663b1 RK |
2643 | } |
2644 | ||
2645 | break; | |
f451db89 JL |
2646 | } |
2647 | ||
336d6f0a RK |
2648 | if (GET_CODE (base) == CONST_INT) |
2649 | { | |
2650 | start += INTVAL (base); | |
2651 | base = const0_rtx; | |
2652 | } | |
2653 | ||
f451db89 JL |
2654 | end = start + size; |
2655 | ||
2656 | /* Set the return values. */ | |
2657 | *pbase = base; | |
2658 | *pstart = start; | |
2659 | *pend = end; | |
2660 | } | |
2661 | ||
9ae8ffe7 JL |
2662 | /* Return 1 if X has a value that can vary even between two |
2663 | executions of the program. 0 means X can be compared reliably | |
2664 | against certain constants or near-constants. */ | |
7afe21cc RK |
2665 | |
2666 | static int | |
9ae8ffe7 JL |
2667 | cse_rtx_varies_p (x) |
2668 | register rtx x; | |
7afe21cc RK |
2669 | { |
2670 | /* We need not check for X and the equivalence class being of the same | |
2671 | mode because if X is equivalent to a constant in some mode, it | |
2672 | doesn't vary in any mode. */ | |
2673 | ||
9ae8ffe7 JL |
2674 | if (GET_CODE (x) == REG |
2675 | && REGNO_QTY_VALID_P (REGNO (x)) | |
30f72379 MM |
2676 | && GET_MODE (x) == qty_mode[REG_QTY (REGNO (x))] |
2677 | && qty_const[REG_QTY (REGNO (x))] != 0) | |
7afe21cc RK |
2678 | return 0; |
2679 | ||
9ae8ffe7 JL |
2680 | if (GET_CODE (x) == PLUS |
2681 | && GET_CODE (XEXP (x, 1)) == CONST_INT | |
2682 | && GET_CODE (XEXP (x, 0)) == REG | |
2683 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))) | |
2684 | && (GET_MODE (XEXP (x, 0)) | |
30f72379 MM |
2685 | == qty_mode[REG_QTY (REGNO (XEXP (x, 0)))]) |
2686 | && qty_const[REG_QTY (REGNO (XEXP (x, 0)))]) | |
7afe21cc RK |
2687 | return 0; |
2688 | ||
9c6b0bae RK |
2689 | /* This can happen as the result of virtual register instantiation, if |
2690 | the initial constant is too large to be a valid address. This gives | |
2691 | us a three instruction sequence, load large offset into a register, | |
2692 | load fp minus a constant into a register, then a MEM which is the | |
2693 | sum of the two `constant' registers. */ | |
9ae8ffe7 JL |
2694 | if (GET_CODE (x) == PLUS |
2695 | && GET_CODE (XEXP (x, 0)) == REG | |
2696 | && GET_CODE (XEXP (x, 1)) == REG | |
2697 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))) | |
2698 | && (GET_MODE (XEXP (x, 0)) | |
30f72379 MM |
2699 | == qty_mode[REG_QTY (REGNO (XEXP (x, 0)))]) |
2700 | && qty_const[REG_QTY (REGNO (XEXP (x, 0)))] | |
9ae8ffe7 JL |
2701 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 1))) |
2702 | && (GET_MODE (XEXP (x, 1)) | |
30f72379 MM |
2703 | == qty_mode[REG_QTY (REGNO (XEXP (x, 1)))]) |
2704 | && qty_const[REG_QTY (REGNO (XEXP (x, 1)))]) | |
9c6b0bae RK |
2705 | return 0; |
2706 | ||
9ae8ffe7 | 2707 | return rtx_varies_p (x); |
7afe21cc RK |
2708 | } |
2709 | \f | |
2710 | /* Canonicalize an expression: | |
2711 | replace each register reference inside it | |
2712 | with the "oldest" equivalent register. | |
2713 | ||
2714 | If INSN is non-zero and we are replacing a pseudo with a hard register | |
7722328e RK |
2715 | or vice versa, validate_change is used to ensure that INSN remains valid |
2716 | after we make our substitution. The calls are made with IN_GROUP non-zero | |
2717 | so apply_change_group must be called upon the outermost return from this | |
2718 | function (unless INSN is zero). The result of apply_change_group can | |
2719 | generally be discarded since the changes we are making are optional. */ | |
7afe21cc RK |
2720 | |
2721 | static rtx | |
2722 | canon_reg (x, insn) | |
2723 | rtx x; | |
2724 | rtx insn; | |
2725 | { | |
2726 | register int i; | |
2727 | register enum rtx_code code; | |
2728 | register char *fmt; | |
2729 | ||
2730 | if (x == 0) | |
2731 | return x; | |
2732 | ||
2733 | code = GET_CODE (x); | |
2734 | switch (code) | |
2735 | { | |
2736 | case PC: | |
2737 | case CC0: | |
2738 | case CONST: | |
2739 | case CONST_INT: | |
2740 | case CONST_DOUBLE: | |
2741 | case SYMBOL_REF: | |
2742 | case LABEL_REF: | |
2743 | case ADDR_VEC: | |
2744 | case ADDR_DIFF_VEC: | |
2745 | return x; | |
2746 | ||
2747 | case REG: | |
2748 | { | |
2749 | register int first; | |
2750 | ||
2751 | /* Never replace a hard reg, because hard regs can appear | |
2752 | in more than one machine mode, and we must preserve the mode | |
2753 | of each occurrence. Also, some hard regs appear in | |
2754 | MEMs that are shared and mustn't be altered. Don't try to | |
2755 | replace any reg that maps to a reg of class NO_REGS. */ | |
2756 | if (REGNO (x) < FIRST_PSEUDO_REGISTER | |
2757 | || ! REGNO_QTY_VALID_P (REGNO (x))) | |
2758 | return x; | |
2759 | ||
30f72379 | 2760 | first = qty_first_reg[REG_QTY (REGNO (x))]; |
7afe21cc RK |
2761 | return (first >= FIRST_PSEUDO_REGISTER ? regno_reg_rtx[first] |
2762 | : REGNO_REG_CLASS (first) == NO_REGS ? x | |
30f72379 | 2763 | : gen_rtx_REG (qty_mode[REG_QTY (REGNO (x))], first)); |
7afe21cc | 2764 | } |
e9a25f70 JL |
2765 | |
2766 | default: | |
2767 | break; | |
7afe21cc RK |
2768 | } |
2769 | ||
2770 | fmt = GET_RTX_FORMAT (code); | |
2771 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2772 | { | |
2773 | register int j; | |
2774 | ||
2775 | if (fmt[i] == 'e') | |
2776 | { | |
2777 | rtx new = canon_reg (XEXP (x, i), insn); | |
58873255 | 2778 | int insn_code; |
7afe21cc RK |
2779 | |
2780 | /* If replacing pseudo with hard reg or vice versa, ensure the | |
178c39f6 | 2781 | insn remains valid. Likewise if the insn has MATCH_DUPs. */ |
aee9dc31 RS |
2782 | if (insn != 0 && new != 0 |
2783 | && GET_CODE (new) == REG && GET_CODE (XEXP (x, i)) == REG | |
178c39f6 RK |
2784 | && (((REGNO (new) < FIRST_PSEUDO_REGISTER) |
2785 | != (REGNO (XEXP (x, i)) < FIRST_PSEUDO_REGISTER)) | |
58873255 RK |
2786 | || (insn_code = recog_memoized (insn)) < 0 |
2787 | || insn_n_dups[insn_code] > 0)) | |
77fa0940 | 2788 | validate_change (insn, &XEXP (x, i), new, 1); |
7afe21cc RK |
2789 | else |
2790 | XEXP (x, i) = new; | |
2791 | } | |
2792 | else if (fmt[i] == 'E') | |
2793 | for (j = 0; j < XVECLEN (x, i); j++) | |
2794 | XVECEXP (x, i, j) = canon_reg (XVECEXP (x, i, j), insn); | |
2795 | } | |
2796 | ||
2797 | return x; | |
2798 | } | |
2799 | \f | |
a2cabb29 | 2800 | /* LOC is a location within INSN that is an operand address (the contents of |
7afe21cc RK |
2801 | a MEM). Find the best equivalent address to use that is valid for this |
2802 | insn. | |
2803 | ||
2804 | On most CISC machines, complicated address modes are costly, and rtx_cost | |
2805 | is a good approximation for that cost. However, most RISC machines have | |
2806 | only a few (usually only one) memory reference formats. If an address is | |
2807 | valid at all, it is often just as cheap as any other address. Hence, for | |
2808 | RISC machines, we use the configuration macro `ADDRESS_COST' to compare the | |
2809 | costs of various addresses. For two addresses of equal cost, choose the one | |
2810 | with the highest `rtx_cost' value as that has the potential of eliminating | |
2811 | the most insns. For equal costs, we choose the first in the equivalence | |
2812 | class. Note that we ignore the fact that pseudo registers are cheaper | |
2813 | than hard registers here because we would also prefer the pseudo registers. | |
2814 | */ | |
2815 | ||
6cd4575e | 2816 | static void |
7afe21cc RK |
2817 | find_best_addr (insn, loc) |
2818 | rtx insn; | |
2819 | rtx *loc; | |
2820 | { | |
7a87758d | 2821 | struct table_elt *elt; |
7afe21cc | 2822 | rtx addr = *loc; |
7a87758d AS |
2823 | #ifdef ADDRESS_COST |
2824 | struct table_elt *p; | |
7afe21cc | 2825 | int found_better = 1; |
7a87758d | 2826 | #endif |
7afe21cc RK |
2827 | int save_do_not_record = do_not_record; |
2828 | int save_hash_arg_in_memory = hash_arg_in_memory; | |
2829 | int save_hash_arg_in_struct = hash_arg_in_struct; | |
7afe21cc RK |
2830 | int addr_volatile; |
2831 | int regno; | |
2197a88a | 2832 | unsigned hash; |
7afe21cc RK |
2833 | |
2834 | /* Do not try to replace constant addresses or addresses of local and | |
2835 | argument slots. These MEM expressions are made only once and inserted | |
2836 | in many instructions, as well as being used to control symbol table | |
2837 | output. It is not safe to clobber them. | |
2838 | ||
2839 | There are some uncommon cases where the address is already in a register | |
2840 | for some reason, but we cannot take advantage of that because we have | |
2841 | no easy way to unshare the MEM. In addition, looking up all stack | |
2842 | addresses is costly. */ | |
2843 | if ((GET_CODE (addr) == PLUS | |
2844 | && GET_CODE (XEXP (addr, 0)) == REG | |
2845 | && GET_CODE (XEXP (addr, 1)) == CONST_INT | |
2846 | && (regno = REGNO (XEXP (addr, 0)), | |
8bc169f2 DE |
2847 | regno == FRAME_POINTER_REGNUM || regno == HARD_FRAME_POINTER_REGNUM |
2848 | || regno == ARG_POINTER_REGNUM)) | |
7afe21cc | 2849 | || (GET_CODE (addr) == REG |
8bc169f2 DE |
2850 | && (regno = REGNO (addr), regno == FRAME_POINTER_REGNUM |
2851 | || regno == HARD_FRAME_POINTER_REGNUM | |
2852 | || regno == ARG_POINTER_REGNUM)) | |
e9a25f70 | 2853 | || GET_CODE (addr) == ADDRESSOF |
7afe21cc RK |
2854 | || CONSTANT_ADDRESS_P (addr)) |
2855 | return; | |
2856 | ||
2857 | /* If this address is not simply a register, try to fold it. This will | |
2858 | sometimes simplify the expression. Many simplifications | |
2859 | will not be valid, but some, usually applying the associative rule, will | |
2860 | be valid and produce better code. */ | |
8c87f107 RK |
2861 | if (GET_CODE (addr) != REG) |
2862 | { | |
2863 | rtx folded = fold_rtx (copy_rtx (addr), NULL_RTX); | |
2864 | ||
2865 | if (1 | |
2866 | #ifdef ADDRESS_COST | |
2f541799 MM |
2867 | && (CSE_ADDRESS_COST (folded) < CSE_ADDRESS_COST (addr) |
2868 | || (CSE_ADDRESS_COST (folded) == CSE_ADDRESS_COST (addr) | |
9a252d29 | 2869 | && rtx_cost (folded, MEM) > rtx_cost (addr, MEM))) |
8c87f107 | 2870 | #else |
9a252d29 | 2871 | && rtx_cost (folded, MEM) < rtx_cost (addr, MEM) |
8c87f107 RK |
2872 | #endif |
2873 | && validate_change (insn, loc, folded, 0)) | |
2874 | addr = folded; | |
2875 | } | |
7afe21cc | 2876 | |
42495ca0 RK |
2877 | /* If this address is not in the hash table, we can't look for equivalences |
2878 | of the whole address. Also, ignore if volatile. */ | |
2879 | ||
7afe21cc | 2880 | do_not_record = 0; |
2197a88a | 2881 | hash = HASH (addr, Pmode); |
7afe21cc RK |
2882 | addr_volatile = do_not_record; |
2883 | do_not_record = save_do_not_record; | |
2884 | hash_arg_in_memory = save_hash_arg_in_memory; | |
2885 | hash_arg_in_struct = save_hash_arg_in_struct; | |
2886 | ||
2887 | if (addr_volatile) | |
2888 | return; | |
2889 | ||
2197a88a | 2890 | elt = lookup (addr, hash, Pmode); |
7afe21cc | 2891 | |
7afe21cc | 2892 | #ifndef ADDRESS_COST |
42495ca0 RK |
2893 | if (elt) |
2894 | { | |
2d8b0f3a | 2895 | int our_cost = elt->cost; |
42495ca0 RK |
2896 | |
2897 | /* Find the lowest cost below ours that works. */ | |
2898 | for (elt = elt->first_same_value; elt; elt = elt->next_same_value) | |
2899 | if (elt->cost < our_cost | |
2900 | && (GET_CODE (elt->exp) == REG | |
2901 | || exp_equiv_p (elt->exp, elt->exp, 1, 0)) | |
2902 | && validate_change (insn, loc, | |
906c4e36 | 2903 | canon_reg (copy_rtx (elt->exp), NULL_RTX), 0)) |
42495ca0 RK |
2904 | return; |
2905 | } | |
2906 | #else | |
7afe21cc | 2907 | |
42495ca0 RK |
2908 | if (elt) |
2909 | { | |
2910 | /* We need to find the best (under the criteria documented above) entry | |
2911 | in the class that is valid. We use the `flag' field to indicate | |
2912 | choices that were invalid and iterate until we can't find a better | |
2913 | one that hasn't already been tried. */ | |
7afe21cc | 2914 | |
42495ca0 RK |
2915 | for (p = elt->first_same_value; p; p = p->next_same_value) |
2916 | p->flag = 0; | |
7afe21cc | 2917 | |
42495ca0 RK |
2918 | while (found_better) |
2919 | { | |
2f541799 | 2920 | int best_addr_cost = CSE_ADDRESS_COST (*loc); |
42495ca0 RK |
2921 | int best_rtx_cost = (elt->cost + 1) >> 1; |
2922 | struct table_elt *best_elt = elt; | |
2923 | ||
2924 | found_better = 0; | |
2925 | for (p = elt->first_same_value; p; p = p->next_same_value) | |
2f541799 | 2926 | if (! p->flag) |
42495ca0 | 2927 | { |
2f541799 MM |
2928 | if ((GET_CODE (p->exp) == REG |
2929 | || exp_equiv_p (p->exp, p->exp, 1, 0)) | |
2930 | && (CSE_ADDRESS_COST (p->exp) < best_addr_cost | |
2931 | || (CSE_ADDRESS_COST (p->exp) == best_addr_cost | |
2932 | && (p->cost + 1) >> 1 > best_rtx_cost))) | |
2933 | { | |
2934 | found_better = 1; | |
2935 | best_addr_cost = CSE_ADDRESS_COST (p->exp); | |
2936 | best_rtx_cost = (p->cost + 1) >> 1; | |
2937 | best_elt = p; | |
2938 | } | |
42495ca0 | 2939 | } |
7afe21cc | 2940 | |
42495ca0 RK |
2941 | if (found_better) |
2942 | { | |
2943 | if (validate_change (insn, loc, | |
906c4e36 RK |
2944 | canon_reg (copy_rtx (best_elt->exp), |
2945 | NULL_RTX), 0)) | |
42495ca0 RK |
2946 | return; |
2947 | else | |
2948 | best_elt->flag = 1; | |
2949 | } | |
2950 | } | |
2951 | } | |
7afe21cc | 2952 | |
42495ca0 RK |
2953 | /* If the address is a binary operation with the first operand a register |
2954 | and the second a constant, do the same as above, but looking for | |
2955 | equivalences of the register. Then try to simplify before checking for | |
2956 | the best address to use. This catches a few cases: First is when we | |
2957 | have REG+const and the register is another REG+const. We can often merge | |
2958 | the constants and eliminate one insn and one register. It may also be | |
2959 | that a machine has a cheap REG+REG+const. Finally, this improves the | |
2960 | code on the Alpha for unaligned byte stores. */ | |
2961 | ||
2962 | if (flag_expensive_optimizations | |
2963 | && (GET_RTX_CLASS (GET_CODE (*loc)) == '2' | |
2964 | || GET_RTX_CLASS (GET_CODE (*loc)) == 'c') | |
2965 | && GET_CODE (XEXP (*loc, 0)) == REG | |
2966 | && GET_CODE (XEXP (*loc, 1)) == CONST_INT) | |
7afe21cc | 2967 | { |
42495ca0 RK |
2968 | rtx c = XEXP (*loc, 1); |
2969 | ||
2970 | do_not_record = 0; | |
2197a88a | 2971 | hash = HASH (XEXP (*loc, 0), Pmode); |
42495ca0 RK |
2972 | do_not_record = save_do_not_record; |
2973 | hash_arg_in_memory = save_hash_arg_in_memory; | |
2974 | hash_arg_in_struct = save_hash_arg_in_struct; | |
2975 | ||
2197a88a | 2976 | elt = lookup (XEXP (*loc, 0), hash, Pmode); |
42495ca0 RK |
2977 | if (elt == 0) |
2978 | return; | |
2979 | ||
2980 | /* We need to find the best (under the criteria documented above) entry | |
2981 | in the class that is valid. We use the `flag' field to indicate | |
2982 | choices that were invalid and iterate until we can't find a better | |
2983 | one that hasn't already been tried. */ | |
7afe21cc | 2984 | |
7afe21cc | 2985 | for (p = elt->first_same_value; p; p = p->next_same_value) |
42495ca0 | 2986 | p->flag = 0; |
7afe21cc | 2987 | |
42495ca0 | 2988 | while (found_better) |
7afe21cc | 2989 | { |
2f541799 | 2990 | int best_addr_cost = CSE_ADDRESS_COST (*loc); |
42495ca0 RK |
2991 | int best_rtx_cost = (COST (*loc) + 1) >> 1; |
2992 | struct table_elt *best_elt = elt; | |
2993 | rtx best_rtx = *loc; | |
f6516aee JW |
2994 | int count; |
2995 | ||
2996 | /* This is at worst case an O(n^2) algorithm, so limit our search | |
2997 | to the first 32 elements on the list. This avoids trouble | |
2998 | compiling code with very long basic blocks that can easily | |
2999 | call cse_gen_binary so many times that we run out of memory. */ | |
42495ca0 RK |
3000 | |
3001 | found_better = 0; | |
f6516aee JW |
3002 | for (p = elt->first_same_value, count = 0; |
3003 | p && count < 32; | |
3004 | p = p->next_same_value, count++) | |
42495ca0 RK |
3005 | if (! p->flag |
3006 | && (GET_CODE (p->exp) == REG | |
3007 | || exp_equiv_p (p->exp, p->exp, 1, 0))) | |
3008 | { | |
96b0e481 | 3009 | rtx new = cse_gen_binary (GET_CODE (*loc), Pmode, p->exp, c); |
42495ca0 | 3010 | |
2f541799 MM |
3011 | if ((CSE_ADDRESS_COST (new) < best_addr_cost |
3012 | || (CSE_ADDRESS_COST (new) == best_addr_cost | |
42495ca0 RK |
3013 | && (COST (new) + 1) >> 1 > best_rtx_cost))) |
3014 | { | |
3015 | found_better = 1; | |
2f541799 | 3016 | best_addr_cost = CSE_ADDRESS_COST (new); |
42495ca0 RK |
3017 | best_rtx_cost = (COST (new) + 1) >> 1; |
3018 | best_elt = p; | |
3019 | best_rtx = new; | |
3020 | } | |
3021 | } | |
3022 | ||
3023 | if (found_better) | |
3024 | { | |
3025 | if (validate_change (insn, loc, | |
906c4e36 RK |
3026 | canon_reg (copy_rtx (best_rtx), |
3027 | NULL_RTX), 0)) | |
42495ca0 RK |
3028 | return; |
3029 | else | |
3030 | best_elt->flag = 1; | |
3031 | } | |
7afe21cc RK |
3032 | } |
3033 | } | |
3034 | #endif | |
3035 | } | |
3036 | \f | |
3037 | /* Given an operation (CODE, *PARG1, *PARG2), where code is a comparison | |
3038 | operation (EQ, NE, GT, etc.), follow it back through the hash table and | |
3039 | what values are being compared. | |
3040 | ||
3041 | *PARG1 and *PARG2 are updated to contain the rtx representing the values | |
3042 | actually being compared. For example, if *PARG1 was (cc0) and *PARG2 | |
3043 | was (const_int 0), *PARG1 and *PARG2 will be set to the objects that were | |
3044 | compared to produce cc0. | |
3045 | ||
3046 | The return value is the comparison operator and is either the code of | |
3047 | A or the code corresponding to the inverse of the comparison. */ | |
3048 | ||
3049 | static enum rtx_code | |
13c9910f | 3050 | find_comparison_args (code, parg1, parg2, pmode1, pmode2) |
7afe21cc RK |
3051 | enum rtx_code code; |
3052 | rtx *parg1, *parg2; | |
13c9910f | 3053 | enum machine_mode *pmode1, *pmode2; |
7afe21cc RK |
3054 | { |
3055 | rtx arg1, arg2; | |
3056 | ||
3057 | arg1 = *parg1, arg2 = *parg2; | |
3058 | ||
3059 | /* If ARG2 is const0_rtx, see what ARG1 is equivalent to. */ | |
3060 | ||
b2796a4b | 3061 | while (arg2 == CONST0_RTX (GET_MODE (arg1))) |
7afe21cc RK |
3062 | { |
3063 | /* Set non-zero when we find something of interest. */ | |
3064 | rtx x = 0; | |
3065 | int reverse_code = 0; | |
3066 | struct table_elt *p = 0; | |
3067 | ||
3068 | /* If arg1 is a COMPARE, extract the comparison arguments from it. | |
3069 | On machines with CC0, this is the only case that can occur, since | |
3070 | fold_rtx will return the COMPARE or item being compared with zero | |
3071 | when given CC0. */ | |
3072 | ||
3073 | if (GET_CODE (arg1) == COMPARE && arg2 == const0_rtx) | |
3074 | x = arg1; | |
3075 | ||
3076 | /* If ARG1 is a comparison operator and CODE is testing for | |
3077 | STORE_FLAG_VALUE, get the inner arguments. */ | |
3078 | ||
3079 | else if (GET_RTX_CLASS (GET_CODE (arg1)) == '<') | |
3080 | { | |
c610adec RK |
3081 | if (code == NE |
3082 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT | |
3083 | && code == LT && STORE_FLAG_VALUE == -1) | |
3084 | #ifdef FLOAT_STORE_FLAG_VALUE | |
3085 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_FLOAT | |
3086 | && FLOAT_STORE_FLAG_VALUE < 0) | |
3087 | #endif | |
3088 | ) | |
7afe21cc | 3089 | x = arg1; |
c610adec RK |
3090 | else if (code == EQ |
3091 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT | |
3092 | && code == GE && STORE_FLAG_VALUE == -1) | |
3093 | #ifdef FLOAT_STORE_FLAG_VALUE | |
3094 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_FLOAT | |
3095 | && FLOAT_STORE_FLAG_VALUE < 0) | |
3096 | #endif | |
3097 | ) | |
7afe21cc RK |
3098 | x = arg1, reverse_code = 1; |
3099 | } | |
3100 | ||
3101 | /* ??? We could also check for | |
3102 | ||
3103 | (ne (and (eq (...) (const_int 1))) (const_int 0)) | |
3104 | ||
3105 | and related forms, but let's wait until we see them occurring. */ | |
3106 | ||
3107 | if (x == 0) | |
3108 | /* Look up ARG1 in the hash table and see if it has an equivalence | |
3109 | that lets us see what is being compared. */ | |
3110 | p = lookup (arg1, safe_hash (arg1, GET_MODE (arg1)) % NBUCKETS, | |
3111 | GET_MODE (arg1)); | |
3112 | if (p) p = p->first_same_value; | |
3113 | ||
3114 | for (; p; p = p->next_same_value) | |
3115 | { | |
3116 | enum machine_mode inner_mode = GET_MODE (p->exp); | |
3117 | ||
3118 | /* If the entry isn't valid, skip it. */ | |
3119 | if (! exp_equiv_p (p->exp, p->exp, 1, 0)) | |
3120 | continue; | |
3121 | ||
3122 | if (GET_CODE (p->exp) == COMPARE | |
3123 | /* Another possibility is that this machine has a compare insn | |
3124 | that includes the comparison code. In that case, ARG1 would | |
3125 | be equivalent to a comparison operation that would set ARG1 to | |
3126 | either STORE_FLAG_VALUE or zero. If this is an NE operation, | |
3127 | ORIG_CODE is the actual comparison being done; if it is an EQ, | |
3128 | we must reverse ORIG_CODE. On machine with a negative value | |
3129 | for STORE_FLAG_VALUE, also look at LT and GE operations. */ | |
3130 | || ((code == NE | |
3131 | || (code == LT | |
c610adec | 3132 | && GET_MODE_CLASS (inner_mode) == MODE_INT |
906c4e36 RK |
3133 | && (GET_MODE_BITSIZE (inner_mode) |
3134 | <= HOST_BITS_PER_WIDE_INT) | |
7afe21cc | 3135 | && (STORE_FLAG_VALUE |
906c4e36 RK |
3136 | & ((HOST_WIDE_INT) 1 |
3137 | << (GET_MODE_BITSIZE (inner_mode) - 1)))) | |
c610adec RK |
3138 | #ifdef FLOAT_STORE_FLAG_VALUE |
3139 | || (code == LT | |
3140 | && GET_MODE_CLASS (inner_mode) == MODE_FLOAT | |
3141 | && FLOAT_STORE_FLAG_VALUE < 0) | |
3142 | #endif | |
3143 | ) | |
7afe21cc RK |
3144 | && GET_RTX_CLASS (GET_CODE (p->exp)) == '<')) |
3145 | { | |
3146 | x = p->exp; | |
3147 | break; | |
3148 | } | |
3149 | else if ((code == EQ | |
3150 | || (code == GE | |
c610adec | 3151 | && GET_MODE_CLASS (inner_mode) == MODE_INT |
906c4e36 RK |
3152 | && (GET_MODE_BITSIZE (inner_mode) |
3153 | <= HOST_BITS_PER_WIDE_INT) | |
7afe21cc | 3154 | && (STORE_FLAG_VALUE |
906c4e36 RK |
3155 | & ((HOST_WIDE_INT) 1 |
3156 | << (GET_MODE_BITSIZE (inner_mode) - 1)))) | |
c610adec RK |
3157 | #ifdef FLOAT_STORE_FLAG_VALUE |
3158 | || (code == GE | |
3159 | && GET_MODE_CLASS (inner_mode) == MODE_FLOAT | |
3160 | && FLOAT_STORE_FLAG_VALUE < 0) | |
3161 | #endif | |
3162 | ) | |
7afe21cc RK |
3163 | && GET_RTX_CLASS (GET_CODE (p->exp)) == '<') |
3164 | { | |
3165 | reverse_code = 1; | |
3166 | x = p->exp; | |
3167 | break; | |
3168 | } | |
3169 | ||
3170 | /* If this is fp + constant, the equivalent is a better operand since | |
3171 | it may let us predict the value of the comparison. */ | |
3172 | else if (NONZERO_BASE_PLUS_P (p->exp)) | |
3173 | { | |
3174 | arg1 = p->exp; | |
3175 | continue; | |
3176 | } | |
3177 | } | |
3178 | ||
3179 | /* If we didn't find a useful equivalence for ARG1, we are done. | |
3180 | Otherwise, set up for the next iteration. */ | |
3181 | if (x == 0) | |
3182 | break; | |
3183 | ||
3184 | arg1 = XEXP (x, 0), arg2 = XEXP (x, 1); | |
3185 | if (GET_RTX_CLASS (GET_CODE (x)) == '<') | |
3186 | code = GET_CODE (x); | |
3187 | ||
3188 | if (reverse_code) | |
3189 | code = reverse_condition (code); | |
3190 | } | |
3191 | ||
13c9910f RS |
3192 | /* Return our results. Return the modes from before fold_rtx |
3193 | because fold_rtx might produce const_int, and then it's too late. */ | |
3194 | *pmode1 = GET_MODE (arg1), *pmode2 = GET_MODE (arg2); | |
7afe21cc RK |
3195 | *parg1 = fold_rtx (arg1, 0), *parg2 = fold_rtx (arg2, 0); |
3196 | ||
3197 | return code; | |
3198 | } | |
3199 | \f | |
3200 | /* Try to simplify a unary operation CODE whose output mode is to be | |
3201 | MODE with input operand OP whose mode was originally OP_MODE. | |
3202 | Return zero if no simplification can be made. */ | |
3203 | ||
3204 | rtx | |
3205 | simplify_unary_operation (code, mode, op, op_mode) | |
3206 | enum rtx_code code; | |
3207 | enum machine_mode mode; | |
3208 | rtx op; | |
3209 | enum machine_mode op_mode; | |
3210 | { | |
3211 | register int width = GET_MODE_BITSIZE (mode); | |
3212 | ||
3213 | /* The order of these tests is critical so that, for example, we don't | |
3214 | check the wrong mode (input vs. output) for a conversion operation, | |
3215 | such as FIX. At some point, this should be simplified. */ | |
3216 | ||
62c0ea12 | 3217 | #if !defined(REAL_IS_NOT_DOUBLE) || defined(REAL_ARITHMETIC) |
7afe21cc | 3218 | |
62c0ea12 RK |
3219 | if (code == FLOAT && GET_MODE (op) == VOIDmode |
3220 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) | |
7afe21cc | 3221 | { |
62c0ea12 | 3222 | HOST_WIDE_INT hv, lv; |
7afe21cc RK |
3223 | REAL_VALUE_TYPE d; |
3224 | ||
62c0ea12 RK |
3225 | if (GET_CODE (op) == CONST_INT) |
3226 | lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0; | |
3227 | else | |
7ac4a266 | 3228 | lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op); |
7afe21cc RK |
3229 | |
3230 | #ifdef REAL_ARITHMETIC | |
2ebcccf3 | 3231 | REAL_VALUE_FROM_INT (d, lv, hv, mode); |
7afe21cc | 3232 | #else |
62c0ea12 | 3233 | if (hv < 0) |
7afe21cc | 3234 | { |
62c0ea12 | 3235 | d = (double) (~ hv); |
906c4e36 RK |
3236 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) |
3237 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
62c0ea12 | 3238 | d += (double) (unsigned HOST_WIDE_INT) (~ lv); |
7afe21cc RK |
3239 | d = (- d - 1.0); |
3240 | } | |
3241 | else | |
3242 | { | |
62c0ea12 | 3243 | d = (double) hv; |
906c4e36 RK |
3244 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) |
3245 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
62c0ea12 | 3246 | d += (double) (unsigned HOST_WIDE_INT) lv; |
7afe21cc RK |
3247 | } |
3248 | #endif /* REAL_ARITHMETIC */ | |
940fd0b5 | 3249 | d = real_value_truncate (mode, d); |
7afe21cc RK |
3250 | return CONST_DOUBLE_FROM_REAL_VALUE (d, mode); |
3251 | } | |
62c0ea12 RK |
3252 | else if (code == UNSIGNED_FLOAT && GET_MODE (op) == VOIDmode |
3253 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) | |
7afe21cc | 3254 | { |
62c0ea12 | 3255 | HOST_WIDE_INT hv, lv; |
7afe21cc RK |
3256 | REAL_VALUE_TYPE d; |
3257 | ||
62c0ea12 RK |
3258 | if (GET_CODE (op) == CONST_INT) |
3259 | lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0; | |
3260 | else | |
7ac4a266 | 3261 | lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op); |
62c0ea12 | 3262 | |
a9c6464d RK |
3263 | if (op_mode == VOIDmode) |
3264 | { | |
3265 | /* We don't know how to interpret negative-looking numbers in | |
3266 | this case, so don't try to fold those. */ | |
3267 | if (hv < 0) | |
3268 | return 0; | |
3269 | } | |
3270 | else if (GET_MODE_BITSIZE (op_mode) >= HOST_BITS_PER_WIDE_INT * 2) | |
62c0ea12 RK |
3271 | ; |
3272 | else | |
3273 | hv = 0, lv &= GET_MODE_MASK (op_mode); | |
3274 | ||
7afe21cc | 3275 | #ifdef REAL_ARITHMETIC |
2ebcccf3 | 3276 | REAL_VALUE_FROM_UNSIGNED_INT (d, lv, hv, mode); |
7afe21cc | 3277 | #else |
62c0ea12 | 3278 | |
138cec59 | 3279 | d = (double) (unsigned HOST_WIDE_INT) hv; |
906c4e36 RK |
3280 | d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) |
3281 | * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); | |
62c0ea12 | 3282 | d += (double) (unsigned HOST_WIDE_INT) lv; |
7afe21cc | 3283 | #endif /* REAL_ARITHMETIC */ |
940fd0b5 | 3284 | d = real_value_truncate (mode, d); |
7afe21cc RK |
3285 | return CONST_DOUBLE_FROM_REAL_VALUE (d, mode); |
3286 | } | |
3287 | #endif | |
3288 | ||
f89e32e9 RK |
3289 | if (GET_CODE (op) == CONST_INT |
3290 | && width <= HOST_BITS_PER_WIDE_INT && width > 0) | |
7afe21cc | 3291 | { |
906c4e36 RK |
3292 | register HOST_WIDE_INT arg0 = INTVAL (op); |
3293 | register HOST_WIDE_INT val; | |
7afe21cc RK |
3294 | |
3295 | switch (code) | |
3296 | { | |
3297 | case NOT: | |
3298 | val = ~ arg0; | |
3299 | break; | |
3300 | ||
3301 | case NEG: | |
3302 | val = - arg0; | |
3303 | break; | |
3304 | ||
3305 | case ABS: | |
3306 | val = (arg0 >= 0 ? arg0 : - arg0); | |
3307 | break; | |
3308 | ||
3309 | case FFS: | |
3310 | /* Don't use ffs here. Instead, get low order bit and then its | |
3311 | number. If arg0 is zero, this will return 0, as desired. */ | |
3312 | arg0 &= GET_MODE_MASK (mode); | |
3313 | val = exact_log2 (arg0 & (- arg0)) + 1; | |
3314 | break; | |
3315 | ||
3316 | case TRUNCATE: | |
3317 | val = arg0; | |
3318 | break; | |
3319 | ||
3320 | case ZERO_EXTEND: | |
3321 | if (op_mode == VOIDmode) | |
3322 | op_mode = mode; | |
82a5e898 | 3323 | if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT) |
d80e9fd7 RS |
3324 | { |
3325 | /* If we were really extending the mode, | |
3326 | we would have to distinguish between zero-extension | |
3327 | and sign-extension. */ | |
3328 | if (width != GET_MODE_BITSIZE (op_mode)) | |
3329 | abort (); | |
3330 | val = arg0; | |
3331 | } | |
82a5e898 CH |
3332 | else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT) |
3333 | val = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode)); | |
7afe21cc RK |
3334 | else |
3335 | return 0; | |
3336 | break; | |
3337 | ||
3338 | case SIGN_EXTEND: | |
3339 | if (op_mode == VOIDmode) | |
3340 | op_mode = mode; | |
82a5e898 | 3341 | if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT) |
d80e9fd7 RS |
3342 | { |
3343 | /* If we were really extending the mode, | |
3344 | we would have to distinguish between zero-extension | |
3345 | and sign-extension. */ | |
3346 | if (width != GET_MODE_BITSIZE (op_mode)) | |
3347 | abort (); | |
3348 | val = arg0; | |
3349 | } | |
f12564b4 | 3350 | else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT) |
7afe21cc | 3351 | { |
82a5e898 CH |
3352 | val |
3353 | = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode)); | |
3354 | if (val | |
3355 | & ((HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (op_mode) - 1))) | |
3356 | val -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode); | |
7afe21cc RK |
3357 | } |
3358 | else | |
3359 | return 0; | |
3360 | break; | |
3361 | ||
d45cf215 RS |
3362 | case SQRT: |
3363 | return 0; | |
3364 | ||
7afe21cc RK |
3365 | default: |
3366 | abort (); | |
3367 | } | |
3368 | ||
7e4ce834 | 3369 | val = trunc_int_for_mode (val, mode); |
737e7965 | 3370 | |
906c4e36 | 3371 | return GEN_INT (val); |
7afe21cc RK |
3372 | } |
3373 | ||
3374 | /* We can do some operations on integer CONST_DOUBLEs. Also allow | |
0f41302f | 3375 | for a DImode operation on a CONST_INT. */ |
8e0ac43b | 3376 | else if (GET_MODE (op) == VOIDmode && width <= HOST_BITS_PER_INT * 2 |
7afe21cc RK |
3377 | && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT)) |
3378 | { | |
906c4e36 | 3379 | HOST_WIDE_INT l1, h1, lv, hv; |
7afe21cc RK |
3380 | |
3381 | if (GET_CODE (op) == CONST_DOUBLE) | |
3382 | l1 = CONST_DOUBLE_LOW (op), h1 = CONST_DOUBLE_HIGH (op); | |
3383 | else | |
3384 | l1 = INTVAL (op), h1 = l1 < 0 ? -1 : 0; | |
3385 | ||
3386 | switch (code) | |
3387 | { | |
3388 | case NOT: | |
3389 | lv = ~ l1; | |
3390 | hv = ~ h1; | |
3391 | break; | |
3392 | ||
3393 | case NEG: | |
3394 | neg_double (l1, h1, &lv, &hv); | |
3395 | break; | |
3396 | ||
3397 | case ABS: | |
3398 | if (h1 < 0) | |
3399 | neg_double (l1, h1, &lv, &hv); | |
3400 | else | |
3401 | lv = l1, hv = h1; | |
3402 | break; | |
3403 | ||
3404 | case FFS: | |
3405 | hv = 0; | |
3406 | if (l1 == 0) | |
906c4e36 | 3407 | lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & (-h1)) + 1; |
7afe21cc RK |
3408 | else |
3409 | lv = exact_log2 (l1 & (-l1)) + 1; | |
3410 | break; | |
3411 | ||
3412 | case TRUNCATE: | |
8e0ac43b | 3413 | /* This is just a change-of-mode, so do nothing. */ |
d50d63c0 | 3414 | lv = l1, hv = h1; |
7afe21cc RK |
3415 | break; |
3416 | ||
f72aed24 RS |
3417 | case ZERO_EXTEND: |
3418 | if (op_mode == VOIDmode | |
906c4e36 | 3419 | || GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT) |
f72aed24 RS |
3420 | return 0; |
3421 | ||
3422 | hv = 0; | |
3423 | lv = l1 & GET_MODE_MASK (op_mode); | |
3424 | break; | |
3425 | ||
3426 | case SIGN_EXTEND: | |
3427 | if (op_mode == VOIDmode | |
906c4e36 | 3428 | || GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT) |
f72aed24 RS |
3429 | return 0; |
3430 | else | |
3431 | { | |
3432 | lv = l1 & GET_MODE_MASK (op_mode); | |
906c4e36 RK |
3433 | if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT |
3434 | && (lv & ((HOST_WIDE_INT) 1 | |
3435 | << (GET_MODE_BITSIZE (op_mode) - 1))) != 0) | |
3436 | lv -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode); | |
f72aed24 | 3437 | |
906c4e36 | 3438 | hv = (lv < 0) ? ~ (HOST_WIDE_INT) 0 : 0; |
f72aed24 RS |
3439 | } |
3440 | break; | |
3441 | ||
d45cf215 RS |
3442 | case SQRT: |
3443 | return 0; | |
3444 | ||
7afe21cc RK |
3445 | default: |
3446 | return 0; | |
3447 | } | |
3448 | ||
3449 | return immed_double_const (lv, hv, mode); | |
3450 | } | |
3451 | ||
3452 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
3453 | else if (GET_CODE (op) == CONST_DOUBLE | |
3454 | && GET_MODE_CLASS (mode) == MODE_FLOAT) | |
3455 | { | |
3456 | REAL_VALUE_TYPE d; | |
3457 | jmp_buf handler; | |
3458 | rtx x; | |
3459 | ||
3460 | if (setjmp (handler)) | |
3461 | /* There used to be a warning here, but that is inadvisable. | |
3462 | People may want to cause traps, and the natural way | |
3463 | to do it should not get a warning. */ | |
3464 | return 0; | |
3465 | ||
3466 | set_float_handler (handler); | |
3467 | ||
3468 | REAL_VALUE_FROM_CONST_DOUBLE (d, op); | |
3469 | ||
3470 | switch (code) | |
3471 | { | |
3472 | case NEG: | |
3473 | d = REAL_VALUE_NEGATE (d); | |
3474 | break; | |
3475 | ||
3476 | case ABS: | |
8b3686ed | 3477 | if (REAL_VALUE_NEGATIVE (d)) |
7afe21cc RK |
3478 | d = REAL_VALUE_NEGATE (d); |
3479 | break; | |
3480 | ||
3481 | case FLOAT_TRUNCATE: | |
d3159aee | 3482 | d = real_value_truncate (mode, d); |
7afe21cc RK |
3483 | break; |
3484 | ||
3485 | case FLOAT_EXTEND: | |
3486 | /* All this does is change the mode. */ | |
3487 | break; | |
3488 | ||
3489 | case FIX: | |
d3159aee | 3490 | d = REAL_VALUE_RNDZINT (d); |
7afe21cc RK |
3491 | break; |
3492 | ||
3493 | case UNSIGNED_FIX: | |
d3159aee | 3494 | d = REAL_VALUE_UNSIGNED_RNDZINT (d); |
7afe21cc RK |
3495 | break; |
3496 | ||
d45cf215 RS |
3497 | case SQRT: |
3498 | return 0; | |
3499 | ||
7afe21cc RK |
3500 | default: |
3501 | abort (); | |
3502 | } | |
3503 | ||
560c94a2 | 3504 | x = CONST_DOUBLE_FROM_REAL_VALUE (d, mode); |
906c4e36 | 3505 | set_float_handler (NULL_PTR); |
7afe21cc RK |
3506 | return x; |
3507 | } | |
8e0ac43b RK |
3508 | |
3509 | else if (GET_CODE (op) == CONST_DOUBLE | |
3510 | && GET_MODE_CLASS (GET_MODE (op)) == MODE_FLOAT | |
3511 | && GET_MODE_CLASS (mode) == MODE_INT | |
906c4e36 | 3512 | && width <= HOST_BITS_PER_WIDE_INT && width > 0) |
7afe21cc RK |
3513 | { |
3514 | REAL_VALUE_TYPE d; | |
3515 | jmp_buf handler; | |
906c4e36 | 3516 | HOST_WIDE_INT val; |
7afe21cc RK |
3517 | |
3518 | if (setjmp (handler)) | |
3519 | return 0; | |
3520 | ||
3521 | set_float_handler (handler); | |
3522 | ||
3523 | REAL_VALUE_FROM_CONST_DOUBLE (d, op); | |
3524 | ||
3525 | switch (code) | |
3526 | { | |
3527 | case FIX: | |
3528 | val = REAL_VALUE_FIX (d); | |
3529 | break; | |
3530 | ||
3531 | case UNSIGNED_FIX: | |
3532 | val = REAL_VALUE_UNSIGNED_FIX (d); | |
3533 | break; | |
3534 | ||
3535 | default: | |
3536 | abort (); | |
3537 | } | |
3538 | ||
906c4e36 | 3539 | set_float_handler (NULL_PTR); |
7afe21cc | 3540 | |
7e4ce834 | 3541 | val = trunc_int_for_mode (val, mode); |
ad89d6f6 | 3542 | |
906c4e36 | 3543 | return GEN_INT (val); |
7afe21cc RK |
3544 | } |
3545 | #endif | |
a6acbe15 RS |
3546 | /* This was formerly used only for non-IEEE float. |
3547 | eggert@twinsun.com says it is safe for IEEE also. */ | |
3548 | else | |
7afe21cc RK |
3549 | { |
3550 | /* There are some simplifications we can do even if the operands | |
a6acbe15 | 3551 | aren't constant. */ |
7afe21cc RK |
3552 | switch (code) |
3553 | { | |
3554 | case NEG: | |
3555 | case NOT: | |
3556 | /* (not (not X)) == X, similarly for NEG. */ | |
3557 | if (GET_CODE (op) == code) | |
3558 | return XEXP (op, 0); | |
3559 | break; | |
3560 | ||
3561 | case SIGN_EXTEND: | |
3562 | /* (sign_extend (truncate (minus (label_ref L1) (label_ref L2)))) | |
3563 | becomes just the MINUS if its mode is MODE. This allows | |
3564 | folding switch statements on machines using casesi (such as | |
3565 | the Vax). */ | |
3566 | if (GET_CODE (op) == TRUNCATE | |
3567 | && GET_MODE (XEXP (op, 0)) == mode | |
3568 | && GET_CODE (XEXP (op, 0)) == MINUS | |
3569 | && GET_CODE (XEXP (XEXP (op, 0), 0)) == LABEL_REF | |
3570 | && GET_CODE (XEXP (XEXP (op, 0), 1)) == LABEL_REF) | |
3571 | return XEXP (op, 0); | |
cceb347c RK |
3572 | |
3573 | #ifdef POINTERS_EXTEND_UNSIGNED | |
3574 | if (! POINTERS_EXTEND_UNSIGNED | |
3575 | && mode == Pmode && GET_MODE (op) == ptr_mode | |
3576 | && CONSTANT_P (op)) | |
3577 | return convert_memory_address (Pmode, op); | |
3578 | #endif | |
3579 | break; | |
3580 | ||
3581 | #ifdef POINTERS_EXTEND_UNSIGNED | |
3582 | case ZERO_EXTEND: | |
3583 | if (POINTERS_EXTEND_UNSIGNED | |
3584 | && mode == Pmode && GET_MODE (op) == ptr_mode | |
3585 | && CONSTANT_P (op)) | |
3586 | return convert_memory_address (Pmode, op); | |
7afe21cc | 3587 | break; |
cceb347c | 3588 | #endif |
e9a25f70 JL |
3589 | |
3590 | default: | |
3591 | break; | |
7afe21cc RK |
3592 | } |
3593 | ||
3594 | return 0; | |
3595 | } | |
7afe21cc RK |
3596 | } |
3597 | \f | |
3598 | /* Simplify a binary operation CODE with result mode MODE, operating on OP0 | |
3599 | and OP1. Return 0 if no simplification is possible. | |
3600 | ||
3601 | Don't use this for relational operations such as EQ or LT. | |
3602 | Use simplify_relational_operation instead. */ | |
3603 | ||
3604 | rtx | |
3605 | simplify_binary_operation (code, mode, op0, op1) | |
3606 | enum rtx_code code; | |
3607 | enum machine_mode mode; | |
3608 | rtx op0, op1; | |
3609 | { | |
906c4e36 RK |
3610 | register HOST_WIDE_INT arg0, arg1, arg0s, arg1s; |
3611 | HOST_WIDE_INT val; | |
7afe21cc | 3612 | int width = GET_MODE_BITSIZE (mode); |
96b0e481 | 3613 | rtx tem; |
7afe21cc RK |
3614 | |
3615 | /* Relational operations don't work here. We must know the mode | |
3616 | of the operands in order to do the comparison correctly. | |
3617 | Assuming a full word can give incorrect results. | |
3618 | Consider comparing 128 with -128 in QImode. */ | |
3619 | ||
3620 | if (GET_RTX_CLASS (code) == '<') | |
3621 | abort (); | |
3622 | ||
3623 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) | |
3624 | if (GET_MODE_CLASS (mode) == MODE_FLOAT | |
3625 | && GET_CODE (op0) == CONST_DOUBLE && GET_CODE (op1) == CONST_DOUBLE | |
3626 | && mode == GET_MODE (op0) && mode == GET_MODE (op1)) | |
3627 | { | |
3628 | REAL_VALUE_TYPE f0, f1, value; | |
3629 | jmp_buf handler; | |
3630 | ||
3631 | if (setjmp (handler)) | |
3632 | return 0; | |
3633 | ||
3634 | set_float_handler (handler); | |
3635 | ||
3636 | REAL_VALUE_FROM_CONST_DOUBLE (f0, op0); | |
3637 | REAL_VALUE_FROM_CONST_DOUBLE (f1, op1); | |
5352b11a RS |
3638 | f0 = real_value_truncate (mode, f0); |
3639 | f1 = real_value_truncate (mode, f1); | |
7afe21cc RK |
3640 | |
3641 | #ifdef REAL_ARITHMETIC | |
956d6950 JL |
3642 | #ifndef REAL_INFINITY |
3643 | if (code == DIV && REAL_VALUES_EQUAL (f1, dconst0)) | |
3644 | return 0; | |
3645 | #endif | |
d3159aee | 3646 | REAL_ARITHMETIC (value, rtx_to_tree_code (code), f0, f1); |
7afe21cc RK |
3647 | #else |
3648 | switch (code) | |
3649 | { | |
3650 | case PLUS: | |
3651 | value = f0 + f1; | |
3652 | break; | |
3653 | case MINUS: | |
3654 | value = f0 - f1; | |
3655 | break; | |
3656 | case MULT: | |
3657 | value = f0 * f1; | |
3658 | break; | |
3659 | case DIV: | |
3660 | #ifndef REAL_INFINITY | |
3661 | if (f1 == 0) | |
21d12b80 | 3662 | return 0; |
7afe21cc RK |
3663 | #endif |
3664 | value = f0 / f1; | |
3665 | break; | |
3666 | case SMIN: | |
3667 | value = MIN (f0, f1); | |
3668 | break; | |
3669 | case SMAX: | |
3670 | value = MAX (f0, f1); | |
3671 | break; | |
3672 | default: | |
3673 | abort (); | |
3674 | } | |
3675 | #endif | |
3676 | ||
5352b11a | 3677 | value = real_value_truncate (mode, value); |
831522a4 | 3678 | set_float_handler (NULL_PTR); |
560c94a2 | 3679 | return CONST_DOUBLE_FROM_REAL_VALUE (value, mode); |
7afe21cc | 3680 | } |
6076248a | 3681 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ |
7afe21cc RK |
3682 | |
3683 | /* We can fold some multi-word operations. */ | |
6076248a | 3684 | if (GET_MODE_CLASS (mode) == MODE_INT |
33085906 | 3685 | && width == HOST_BITS_PER_WIDE_INT * 2 |
fe873240 | 3686 | && (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT) |
6076248a | 3687 | && (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT)) |
7afe21cc | 3688 | { |
906c4e36 | 3689 | HOST_WIDE_INT l1, l2, h1, h2, lv, hv; |
7afe21cc | 3690 | |
fe873240 RK |
3691 | if (GET_CODE (op0) == CONST_DOUBLE) |
3692 | l1 = CONST_DOUBLE_LOW (op0), h1 = CONST_DOUBLE_HIGH (op0); | |
3693 | else | |
3694 | l1 = INTVAL (op0), h1 = l1 < 0 ? -1 : 0; | |
7afe21cc RK |
3695 | |
3696 | if (GET_CODE (op1) == CONST_DOUBLE) | |
3697 | l2 = CONST_DOUBLE_LOW (op1), h2 = CONST_DOUBLE_HIGH (op1); | |
3698 | else | |
3699 | l2 = INTVAL (op1), h2 = l2 < 0 ? -1 : 0; | |
3700 | ||
3701 | switch (code) | |
3702 | { | |
3703 | case MINUS: | |
3704 | /* A - B == A + (-B). */ | |
3705 | neg_double (l2, h2, &lv, &hv); | |
3706 | l2 = lv, h2 = hv; | |
3707 | ||
0f41302f | 3708 | /* .. fall through ... */ |
7afe21cc RK |
3709 | |
3710 | case PLUS: | |
3711 | add_double (l1, h1, l2, h2, &lv, &hv); | |
3712 | break; | |
3713 | ||
3714 | case MULT: | |
3715 | mul_double (l1, h1, l2, h2, &lv, &hv); | |
3716 | break; | |
3717 | ||
3718 | case DIV: case MOD: case UDIV: case UMOD: | |
3719 | /* We'd need to include tree.h to do this and it doesn't seem worth | |
3720 | it. */ | |
3721 | return 0; | |
3722 | ||
3723 | case AND: | |
3724 | lv = l1 & l2, hv = h1 & h2; | |
3725 | break; | |
3726 | ||
3727 | case IOR: | |
3728 | lv = l1 | l2, hv = h1 | h2; | |
3729 | break; | |
3730 | ||
3731 | case XOR: | |
3732 | lv = l1 ^ l2, hv = h1 ^ h2; | |
3733 | break; | |
3734 | ||
3735 | case SMIN: | |
906c4e36 RK |
3736 | if (h1 < h2 |
3737 | || (h1 == h2 | |
3738 | && ((unsigned HOST_WIDE_INT) l1 | |
3739 | < (unsigned HOST_WIDE_INT) l2))) | |
7afe21cc RK |
3740 | lv = l1, hv = h1; |
3741 | else | |
3742 | lv = l2, hv = h2; | |
3743 | break; | |
3744 | ||
3745 | case SMAX: | |
906c4e36 RK |
3746 | if (h1 > h2 |
3747 | || (h1 == h2 | |
3748 | && ((unsigned HOST_WIDE_INT) l1 | |
3749 | > (unsigned HOST_WIDE_INT) l2))) | |
7afe21cc RK |
3750 | lv = l1, hv = h1; |
3751 | else | |
3752 | lv = l2, hv = h2; | |
3753 | break; | |
3754 | ||
3755 | case UMIN: | |
906c4e36 RK |
3756 | if ((unsigned HOST_WIDE_INT) h1 < (unsigned HOST_WIDE_INT) h2 |
3757 | || (h1 == h2 | |
3758 | && ((unsigned HOST_WIDE_INT) l1 | |
3759 | < (unsigned HOST_WIDE_INT) l2))) | |
7afe21cc RK |
3760 | lv = l1, hv = h1; |
3761 | else | |
3762 | lv = l2, hv = h2; | |
3763 | break; | |
3764 | ||
3765 | case UMAX: | |
906c4e36 RK |
3766 | if ((unsigned HOST_WIDE_INT) h1 > (unsigned HOST_WIDE_INT) h2 |
3767 | || (h1 == h2 | |
3768 | && ((unsigned HOST_WIDE_INT) l1 | |
3769 | > (unsigned HOST_WIDE_INT) l2))) | |
7afe21cc RK |
3770 | lv = l1, hv = h1; |
3771 | else | |
3772 | lv = l2, hv = h2; | |
3773 | break; | |
3774 | ||
3775 | case LSHIFTRT: case ASHIFTRT: | |
45620ed4 | 3776 | case ASHIFT: |
7afe21cc RK |
3777 | case ROTATE: case ROTATERT: |
3778 | #ifdef SHIFT_COUNT_TRUNCATED | |
85c0a556 RK |
3779 | if (SHIFT_COUNT_TRUNCATED) |
3780 | l2 &= (GET_MODE_BITSIZE (mode) - 1), h2 = 0; | |
7afe21cc RK |
3781 | #endif |
3782 | ||
3783 | if (h2 != 0 || l2 < 0 || l2 >= GET_MODE_BITSIZE (mode)) | |
3784 | return 0; | |
3785 | ||
3786 | if (code == LSHIFTRT || code == ASHIFTRT) | |
3787 | rshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv, | |
3788 | code == ASHIFTRT); | |
45620ed4 RK |
3789 | else if (code == ASHIFT) |
3790 | lshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv, 1); | |
7afe21cc RK |
3791 | else if (code == ROTATE) |
3792 | lrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv); | |
3793 | else /* code == ROTATERT */ | |
3794 | rrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv); | |
3795 | break; | |
3796 | ||
3797 | default: | |
3798 | return 0; | |
3799 | } | |
3800 | ||
3801 | return immed_double_const (lv, hv, mode); | |
3802 | } | |
7afe21cc RK |
3803 | |
3804 | if (GET_CODE (op0) != CONST_INT || GET_CODE (op1) != CONST_INT | |
906c4e36 | 3805 | || width > HOST_BITS_PER_WIDE_INT || width == 0) |
7afe21cc RK |
3806 | { |
3807 | /* Even if we can't compute a constant result, | |
3808 | there are some cases worth simplifying. */ | |
3809 | ||
3810 | switch (code) | |
3811 | { | |
3812 | case PLUS: | |
3813 | /* In IEEE floating point, x+0 is not the same as x. Similarly | |
3814 | for the other optimizations below. */ | |
3815 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
a83afb65 | 3816 | && FLOAT_MODE_P (mode) && ! flag_fast_math) |
7afe21cc RK |
3817 | break; |
3818 | ||
3819 | if (op1 == CONST0_RTX (mode)) | |
3820 | return op0; | |
3821 | ||
7afe21cc RK |
3822 | /* ((-a) + b) -> (b - a) and similarly for (a + (-b)) */ |
3823 | if (GET_CODE (op0) == NEG) | |
96b0e481 | 3824 | return cse_gen_binary (MINUS, mode, op1, XEXP (op0, 0)); |
7afe21cc | 3825 | else if (GET_CODE (op1) == NEG) |
96b0e481 | 3826 | return cse_gen_binary (MINUS, mode, op0, XEXP (op1, 0)); |
7afe21cc | 3827 | |
96b0e481 RK |
3828 | /* Handle both-operands-constant cases. We can only add |
3829 | CONST_INTs to constants since the sum of relocatable symbols | |
fe873240 RK |
3830 | can't be handled by most assemblers. Don't add CONST_INT |
3831 | to CONST_INT since overflow won't be computed properly if wider | |
3832 | than HOST_BITS_PER_WIDE_INT. */ | |
7afe21cc | 3833 | |
fe873240 RK |
3834 | if (CONSTANT_P (op0) && GET_MODE (op0) != VOIDmode |
3835 | && GET_CODE (op1) == CONST_INT) | |
96b0e481 | 3836 | return plus_constant (op0, INTVAL (op1)); |
fe873240 RK |
3837 | else if (CONSTANT_P (op1) && GET_MODE (op1) != VOIDmode |
3838 | && GET_CODE (op0) == CONST_INT) | |
96b0e481 | 3839 | return plus_constant (op1, INTVAL (op0)); |
7afe21cc | 3840 | |
30d69925 RK |
3841 | /* See if this is something like X * C - X or vice versa or |
3842 | if the multiplication is written as a shift. If so, we can | |
3843 | distribute and make a new multiply, shift, or maybe just | |
3844 | have X (if C is 2 in the example above). But don't make | |
3845 | real multiply if we didn't have one before. */ | |
3846 | ||
3847 | if (! FLOAT_MODE_P (mode)) | |
3848 | { | |
3849 | HOST_WIDE_INT coeff0 = 1, coeff1 = 1; | |
3850 | rtx lhs = op0, rhs = op1; | |
3851 | int had_mult = 0; | |
3852 | ||
3853 | if (GET_CODE (lhs) == NEG) | |
3854 | coeff0 = -1, lhs = XEXP (lhs, 0); | |
3855 | else if (GET_CODE (lhs) == MULT | |
3856 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT) | |
3857 | { | |
3858 | coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0); | |
3859 | had_mult = 1; | |
3860 | } | |
3861 | else if (GET_CODE (lhs) == ASHIFT | |
3862 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT | |
3863 | && INTVAL (XEXP (lhs, 1)) >= 0 | |
3864 | && INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
3865 | { | |
3866 | coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1)); | |
3867 | lhs = XEXP (lhs, 0); | |
3868 | } | |
3869 | ||
3870 | if (GET_CODE (rhs) == NEG) | |
3871 | coeff1 = -1, rhs = XEXP (rhs, 0); | |
3872 | else if (GET_CODE (rhs) == MULT | |
3873 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT) | |
3874 | { | |
3875 | coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0); | |
3876 | had_mult = 1; | |
3877 | } | |
3878 | else if (GET_CODE (rhs) == ASHIFT | |
3879 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT | |
3880 | && INTVAL (XEXP (rhs, 1)) >= 0 | |
3881 | && INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
3882 | { | |
3883 | coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)); | |
3884 | rhs = XEXP (rhs, 0); | |
3885 | } | |
3886 | ||
3887 | if (rtx_equal_p (lhs, rhs)) | |
3888 | { | |
3889 | tem = cse_gen_binary (MULT, mode, lhs, | |
3890 | GEN_INT (coeff0 + coeff1)); | |
3891 | return (GET_CODE (tem) == MULT && ! had_mult) ? 0 : tem; | |
3892 | } | |
3893 | } | |
3894 | ||
96b0e481 RK |
3895 | /* If one of the operands is a PLUS or a MINUS, see if we can |
3896 | simplify this by the associative law. | |
3897 | Don't use the associative law for floating point. | |
3898 | The inaccuracy makes it nonassociative, | |
3899 | and subtle programs can break if operations are associated. */ | |
7afe21cc | 3900 | |
cbf6a543 | 3901 | if (INTEGRAL_MODE_P (mode) |
96b0e481 RK |
3902 | && (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS |
3903 | || GET_CODE (op1) == PLUS || GET_CODE (op1) == MINUS) | |
3904 | && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0) | |
3905 | return tem; | |
7afe21cc RK |
3906 | break; |
3907 | ||
3908 | case COMPARE: | |
3909 | #ifdef HAVE_cc0 | |
3910 | /* Convert (compare FOO (const_int 0)) to FOO unless we aren't | |
3911 | using cc0, in which case we want to leave it as a COMPARE | |
3912 | so we can distinguish it from a register-register-copy. | |
3913 | ||
3914 | In IEEE floating point, x-0 is not the same as x. */ | |
3915 | ||
3916 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
a83afb65 | 3917 | || ! FLOAT_MODE_P (mode) || flag_fast_math) |
7afe21cc RK |
3918 | && op1 == CONST0_RTX (mode)) |
3919 | return op0; | |
3920 | #else | |
3921 | /* Do nothing here. */ | |
3922 | #endif | |
3923 | break; | |
3924 | ||
3925 | case MINUS: | |
21648b45 RK |
3926 | /* None of these optimizations can be done for IEEE |
3927 | floating point. */ | |
3928 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
a83afb65 | 3929 | && FLOAT_MODE_P (mode) && ! flag_fast_math) |
21648b45 RK |
3930 | break; |
3931 | ||
a83afb65 RK |
3932 | /* We can't assume x-x is 0 even with non-IEEE floating point, |
3933 | but since it is zero except in very strange circumstances, we | |
3934 | will treat it as zero with -ffast-math. */ | |
7afe21cc RK |
3935 | if (rtx_equal_p (op0, op1) |
3936 | && ! side_effects_p (op0) | |
a83afb65 RK |
3937 | && (! FLOAT_MODE_P (mode) || flag_fast_math)) |
3938 | return CONST0_RTX (mode); | |
7afe21cc RK |
3939 | |
3940 | /* Change subtraction from zero into negation. */ | |
3941 | if (op0 == CONST0_RTX (mode)) | |
38a448ca | 3942 | return gen_rtx_NEG (mode, op1); |
7afe21cc | 3943 | |
96b0e481 RK |
3944 | /* (-1 - a) is ~a. */ |
3945 | if (op0 == constm1_rtx) | |
38a448ca | 3946 | return gen_rtx_NOT (mode, op1); |
96b0e481 | 3947 | |
7afe21cc RK |
3948 | /* Subtracting 0 has no effect. */ |
3949 | if (op1 == CONST0_RTX (mode)) | |
3950 | return op0; | |
3951 | ||
30d69925 RK |
3952 | /* See if this is something like X * C - X or vice versa or |
3953 | if the multiplication is written as a shift. If so, we can | |
3954 | distribute and make a new multiply, shift, or maybe just | |
3955 | have X (if C is 2 in the example above). But don't make | |
3956 | real multiply if we didn't have one before. */ | |
3957 | ||
3958 | if (! FLOAT_MODE_P (mode)) | |
3959 | { | |
3960 | HOST_WIDE_INT coeff0 = 1, coeff1 = 1; | |
3961 | rtx lhs = op0, rhs = op1; | |
3962 | int had_mult = 0; | |
3963 | ||
3964 | if (GET_CODE (lhs) == NEG) | |
3965 | coeff0 = -1, lhs = XEXP (lhs, 0); | |
3966 | else if (GET_CODE (lhs) == MULT | |
3967 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT) | |
3968 | { | |
3969 | coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0); | |
3970 | had_mult = 1; | |
3971 | } | |
3972 | else if (GET_CODE (lhs) == ASHIFT | |
3973 | && GET_CODE (XEXP (lhs, 1)) == CONST_INT | |
3974 | && INTVAL (XEXP (lhs, 1)) >= 0 | |
3975 | && INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
3976 | { | |
3977 | coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1)); | |
3978 | lhs = XEXP (lhs, 0); | |
3979 | } | |
3980 | ||
3981 | if (GET_CODE (rhs) == NEG) | |
3982 | coeff1 = - 1, rhs = XEXP (rhs, 0); | |
3983 | else if (GET_CODE (rhs) == MULT | |
3984 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT) | |
3985 | { | |
3986 | coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0); | |
3987 | had_mult = 1; | |
3988 | } | |
3989 | else if (GET_CODE (rhs) == ASHIFT | |
3990 | && GET_CODE (XEXP (rhs, 1)) == CONST_INT | |
3991 | && INTVAL (XEXP (rhs, 1)) >= 0 | |
3992 | && INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT) | |
3993 | { | |
3994 | coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)); | |
3995 | rhs = XEXP (rhs, 0); | |
3996 | } | |
3997 | ||
3998 | if (rtx_equal_p (lhs, rhs)) | |
3999 | { | |
4000 | tem = cse_gen_binary (MULT, mode, lhs, | |
4001 | GEN_INT (coeff0 - coeff1)); | |
4002 | return (GET_CODE (tem) == MULT && ! had_mult) ? 0 : tem; | |
4003 | } | |
4004 | } | |
4005 | ||
7afe21cc RK |
4006 | /* (a - (-b)) -> (a + b). */ |
4007 | if (GET_CODE (op1) == NEG) | |
96b0e481 | 4008 | return cse_gen_binary (PLUS, mode, op0, XEXP (op1, 0)); |
7afe21cc | 4009 | |
96b0e481 RK |
4010 | /* If one of the operands is a PLUS or a MINUS, see if we can |
4011 | simplify this by the associative law. | |
4012 | Don't use the associative law for floating point. | |
7afe21cc RK |
4013 | The inaccuracy makes it nonassociative, |
4014 | and subtle programs can break if operations are associated. */ | |
7afe21cc | 4015 | |
cbf6a543 | 4016 | if (INTEGRAL_MODE_P (mode) |
96b0e481 RK |
4017 | && (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS |
4018 | || GET_CODE (op1) == PLUS || GET_CODE (op1) == MINUS) | |
4019 | && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0) | |
4020 | return tem; | |
7afe21cc RK |
4021 | |
4022 | /* Don't let a relocatable value get a negative coeff. */ | |
b5a09c41 | 4023 | if (GET_CODE (op1) == CONST_INT && GET_MODE (op0) != VOIDmode) |
7afe21cc | 4024 | return plus_constant (op0, - INTVAL (op1)); |
29d72c4b TG |
4025 | |
4026 | /* (x - (x & y)) -> (x & ~y) */ | |
4027 | if (GET_CODE (op1) == AND) | |
4028 | { | |
4029 | if (rtx_equal_p (op0, XEXP (op1, 0))) | |
38a448ca | 4030 | return cse_gen_binary (AND, mode, op0, gen_rtx_NOT (mode, XEXP (op1, 1))); |
29d72c4b | 4031 | if (rtx_equal_p (op0, XEXP (op1, 1))) |
38a448ca | 4032 | return cse_gen_binary (AND, mode, op0, gen_rtx_NOT (mode, XEXP (op1, 0))); |
29d72c4b | 4033 | } |
7afe21cc RK |
4034 | break; |
4035 | ||
4036 | case MULT: | |
4037 | if (op1 == constm1_rtx) | |
4038 | { | |
96b0e481 | 4039 | tem = simplify_unary_operation (NEG, mode, op0, mode); |
7afe21cc | 4040 | |
38a448ca | 4041 | return tem ? tem : gen_rtx_NEG (mode, op0); |
7afe21cc RK |
4042 | } |
4043 | ||
4044 | /* In IEEE floating point, x*0 is not always 0. */ | |
4045 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
a83afb65 | 4046 | || ! FLOAT_MODE_P (mode) || flag_fast_math) |
7afe21cc RK |
4047 | && op1 == CONST0_RTX (mode) |
4048 | && ! side_effects_p (op0)) | |
4049 | return op1; | |
4050 | ||
4051 | /* In IEEE floating point, x*1 is not equivalent to x for nans. | |
4052 | However, ANSI says we can drop signals, | |
4053 | so we can do this anyway. */ | |
4054 | if (op1 == CONST1_RTX (mode)) | |
4055 | return op0; | |
4056 | ||
c407b802 RK |
4057 | /* Convert multiply by constant power of two into shift unless |
4058 | we are still generating RTL. This test is a kludge. */ | |
7afe21cc | 4059 | if (GET_CODE (op1) == CONST_INT |
c407b802 | 4060 | && (val = exact_log2 (INTVAL (op1))) >= 0 |
2d917903 JW |
4061 | /* If the mode is larger than the host word size, and the |
4062 | uppermost bit is set, then this isn't a power of two due | |
4063 | to implicit sign extension. */ | |
4064 | && (width <= HOST_BITS_PER_WIDE_INT | |
4065 | || val != HOST_BITS_PER_WIDE_INT - 1) | |
c407b802 | 4066 | && ! rtx_equal_function_value_matters) |
38a448ca | 4067 | return gen_rtx_ASHIFT (mode, op0, GEN_INT (val)); |
7afe21cc RK |
4068 | |
4069 | if (GET_CODE (op1) == CONST_DOUBLE | |
4070 | && GET_MODE_CLASS (GET_MODE (op1)) == MODE_FLOAT) | |
4071 | { | |
4072 | REAL_VALUE_TYPE d; | |
5a3d4bef RK |
4073 | jmp_buf handler; |
4074 | int op1is2, op1ism1; | |
4075 | ||
4076 | if (setjmp (handler)) | |
4077 | return 0; | |
4078 | ||
4079 | set_float_handler (handler); | |
7afe21cc | 4080 | REAL_VALUE_FROM_CONST_DOUBLE (d, op1); |
5a3d4bef RK |
4081 | op1is2 = REAL_VALUES_EQUAL (d, dconst2); |
4082 | op1ism1 = REAL_VALUES_EQUAL (d, dconstm1); | |
4083 | set_float_handler (NULL_PTR); | |
7afe21cc RK |
4084 | |
4085 | /* x*2 is x+x and x*(-1) is -x */ | |
5a3d4bef | 4086 | if (op1is2 && GET_MODE (op0) == mode) |
38a448ca | 4087 | return gen_rtx_PLUS (mode, op0, copy_rtx (op0)); |
7afe21cc | 4088 | |
5a3d4bef | 4089 | else if (op1ism1 && GET_MODE (op0) == mode) |
38a448ca | 4090 | return gen_rtx_NEG (mode, op0); |
7afe21cc RK |
4091 | } |
4092 | break; | |
4093 | ||
4094 | case IOR: | |
4095 | if (op1 == const0_rtx) | |
4096 | return op0; | |
4097 | if (GET_CODE (op1) == CONST_INT | |
4098 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
4099 | return op1; | |
4100 | if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4101 | return op0; | |
4102 | /* A | (~A) -> -1 */ | |
4103 | if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1)) | |
4104 | || (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0))) | |
31dcf83f | 4105 | && ! side_effects_p (op0) |
8e7e5365 | 4106 | && GET_MODE_CLASS (mode) != MODE_CC) |
7afe21cc RK |
4107 | return constm1_rtx; |
4108 | break; | |
4109 | ||
4110 | case XOR: | |
4111 | if (op1 == const0_rtx) | |
4112 | return op0; | |
4113 | if (GET_CODE (op1) == CONST_INT | |
4114 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
38a448ca | 4115 | return gen_rtx_NOT (mode, op0); |
31dcf83f | 4116 | if (op0 == op1 && ! side_effects_p (op0) |
8e7e5365 | 4117 | && GET_MODE_CLASS (mode) != MODE_CC) |
7afe21cc RK |
4118 | return const0_rtx; |
4119 | break; | |
4120 | ||
4121 | case AND: | |
4122 | if (op1 == const0_rtx && ! side_effects_p (op0)) | |
4123 | return const0_rtx; | |
4124 | if (GET_CODE (op1) == CONST_INT | |
4125 | && (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode)) | |
4126 | return op0; | |
31dcf83f | 4127 | if (op0 == op1 && ! side_effects_p (op0) |
8e7e5365 | 4128 | && GET_MODE_CLASS (mode) != MODE_CC) |
7afe21cc RK |
4129 | return op0; |
4130 | /* A & (~A) -> 0 */ | |
4131 | if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1)) | |
4132 | || (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0))) | |
709ab4fc | 4133 | && ! side_effects_p (op0) |
8e7e5365 | 4134 | && GET_MODE_CLASS (mode) != MODE_CC) |
7afe21cc RK |
4135 | return const0_rtx; |
4136 | break; | |
4137 | ||
4138 | case UDIV: | |
4139 | /* Convert divide by power of two into shift (divide by 1 handled | |
4140 | below). */ | |
4141 | if (GET_CODE (op1) == CONST_INT | |
4142 | && (arg1 = exact_log2 (INTVAL (op1))) > 0) | |
38a448ca | 4143 | return gen_rtx_LSHIFTRT (mode, op0, GEN_INT (arg1)); |
7afe21cc | 4144 | |
0f41302f | 4145 | /* ... fall through ... */ |
7afe21cc RK |
4146 | |
4147 | case DIV: | |
4148 | if (op1 == CONST1_RTX (mode)) | |
4149 | return op0; | |
e7a522ba RS |
4150 | |
4151 | /* In IEEE floating point, 0/x is not always 0. */ | |
4152 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
a83afb65 | 4153 | || ! FLOAT_MODE_P (mode) || flag_fast_math) |
e7a522ba RS |
4154 | && op0 == CONST0_RTX (mode) |
4155 | && ! side_effects_p (op1)) | |
7afe21cc | 4156 | return op0; |
e7a522ba | 4157 | |
7afe21cc | 4158 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) |
a83afb65 RK |
4159 | /* Change division by a constant into multiplication. Only do |
4160 | this with -ffast-math until an expert says it is safe in | |
4161 | general. */ | |
7afe21cc RK |
4162 | else if (GET_CODE (op1) == CONST_DOUBLE |
4163 | && GET_MODE_CLASS (GET_MODE (op1)) == MODE_FLOAT | |
a83afb65 RK |
4164 | && op1 != CONST0_RTX (mode) |
4165 | && flag_fast_math) | |
7afe21cc RK |
4166 | { |
4167 | REAL_VALUE_TYPE d; | |
4168 | REAL_VALUE_FROM_CONST_DOUBLE (d, op1); | |
a83afb65 RK |
4169 | |
4170 | if (! REAL_VALUES_EQUAL (d, dconst0)) | |
4171 | { | |
7afe21cc | 4172 | #if defined (REAL_ARITHMETIC) |
a83afb65 | 4173 | REAL_ARITHMETIC (d, rtx_to_tree_code (DIV), dconst1, d); |
38a448ca RH |
4174 | return gen_rtx_MULT (mode, op0, |
4175 | CONST_DOUBLE_FROM_REAL_VALUE (d, mode)); | |
7afe21cc | 4176 | #else |
38a448ca RH |
4177 | return gen_rtx_MULT (mode, op0, |
4178 | CONST_DOUBLE_FROM_REAL_VALUE (1./d, mode)); | |
7afe21cc | 4179 | #endif |
a83afb65 RK |
4180 | } |
4181 | } | |
7afe21cc RK |
4182 | #endif |
4183 | break; | |
4184 | ||
4185 | case UMOD: | |
4186 | /* Handle modulus by power of two (mod with 1 handled below). */ | |
4187 | if (GET_CODE (op1) == CONST_INT | |
4188 | && exact_log2 (INTVAL (op1)) > 0) | |
38a448ca | 4189 | return gen_rtx_AND (mode, op0, GEN_INT (INTVAL (op1) - 1)); |
7afe21cc | 4190 | |
0f41302f | 4191 | /* ... fall through ... */ |
7afe21cc RK |
4192 | |
4193 | case MOD: | |
4194 | if ((op0 == const0_rtx || op1 == const1_rtx) | |
4195 | && ! side_effects_p (op0) && ! side_effects_p (op1)) | |
4196 | return const0_rtx; | |
4197 | break; | |
4198 | ||
4199 | case ROTATERT: | |
4200 | case ROTATE: | |
4201 | /* Rotating ~0 always results in ~0. */ | |
906c4e36 | 4202 | if (GET_CODE (op0) == CONST_INT && width <= HOST_BITS_PER_WIDE_INT |
7afe21cc RK |
4203 | && INTVAL (op0) == GET_MODE_MASK (mode) |
4204 | && ! side_effects_p (op1)) | |
4205 | return op0; | |
4206 | ||
0f41302f | 4207 | /* ... fall through ... */ |
7afe21cc | 4208 | |
7afe21cc RK |
4209 | case ASHIFT: |
4210 | case ASHIFTRT: | |
4211 | case LSHIFTRT: | |
4212 | if (op1 == const0_rtx) | |
4213 | return op0; | |
4214 | if (op0 == const0_rtx && ! side_effects_p (op1)) | |
4215 | return op0; | |
4216 | break; | |
4217 | ||
4218 | case SMIN: | |
906c4e36 RK |
4219 | if (width <= HOST_BITS_PER_WIDE_INT && GET_CODE (op1) == CONST_INT |
4220 | && INTVAL (op1) == (HOST_WIDE_INT) 1 << (width -1) | |
7afe21cc RK |
4221 | && ! side_effects_p (op0)) |
4222 | return op1; | |
4223 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4224 | return op0; | |
4225 | break; | |
4226 | ||
4227 | case SMAX: | |
906c4e36 | 4228 | if (width <= HOST_BITS_PER_WIDE_INT && GET_CODE (op1) == CONST_INT |
dbbe6445 RK |
4229 | && (INTVAL (op1) |
4230 | == (unsigned HOST_WIDE_INT) GET_MODE_MASK (mode) >> 1) | |
7afe21cc RK |
4231 | && ! side_effects_p (op0)) |
4232 | return op1; | |
4233 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4234 | return op0; | |
4235 | break; | |
4236 | ||
4237 | case UMIN: | |
4238 | if (op1 == const0_rtx && ! side_effects_p (op0)) | |
4239 | return op1; | |
4240 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4241 | return op0; | |
4242 | break; | |
4243 | ||
4244 | case UMAX: | |
4245 | if (op1 == constm1_rtx && ! side_effects_p (op0)) | |
4246 | return op1; | |
4247 | else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0)) | |
4248 | return op0; | |
4249 | break; | |
4250 | ||
4251 | default: | |
4252 | abort (); | |
4253 | } | |
4254 | ||
4255 | return 0; | |
4256 | } | |
4257 | ||
4258 | /* Get the integer argument values in two forms: | |
4259 | zero-extended in ARG0, ARG1 and sign-extended in ARG0S, ARG1S. */ | |
4260 | ||
4261 | arg0 = INTVAL (op0); | |
4262 | arg1 = INTVAL (op1); | |
4263 | ||
906c4e36 | 4264 | if (width < HOST_BITS_PER_WIDE_INT) |
7afe21cc | 4265 | { |
906c4e36 RK |
4266 | arg0 &= ((HOST_WIDE_INT) 1 << width) - 1; |
4267 | arg1 &= ((HOST_WIDE_INT) 1 << width) - 1; | |
7afe21cc RK |
4268 | |
4269 | arg0s = arg0; | |
906c4e36 RK |
4270 | if (arg0s & ((HOST_WIDE_INT) 1 << (width - 1))) |
4271 | arg0s |= ((HOST_WIDE_INT) (-1) << width); | |
7afe21cc RK |
4272 | |
4273 | arg1s = arg1; | |
906c4e36 RK |
4274 | if (arg1s & ((HOST_WIDE_INT) 1 << (width - 1))) |
4275 | arg1s |= ((HOST_WIDE_INT) (-1) << width); | |
7afe21cc RK |
4276 | } |
4277 | else | |
4278 | { | |
4279 | arg0s = arg0; | |
4280 | arg1s = arg1; | |
4281 | } | |
4282 | ||
4283 | /* Compute the value of the arithmetic. */ | |
4284 | ||
4285 | switch (code) | |
4286 | { | |
4287 | case PLUS: | |
538b78e7 | 4288 | val = arg0s + arg1s; |
7afe21cc RK |
4289 | break; |
4290 | ||
4291 | case MINUS: | |
538b78e7 | 4292 | val = arg0s - arg1s; |
7afe21cc RK |
4293 | break; |
4294 | ||
4295 | case MULT: | |
4296 | val = arg0s * arg1s; | |
4297 | break; | |
4298 | ||
4299 | case DIV: | |
4300 | if (arg1s == 0) | |
4301 | return 0; | |
4302 | val = arg0s / arg1s; | |
4303 | break; | |
4304 | ||
4305 | case MOD: | |
4306 | if (arg1s == 0) | |
4307 | return 0; | |
4308 | val = arg0s % arg1s; | |
4309 | break; | |
4310 | ||
4311 | case UDIV: | |
4312 | if (arg1 == 0) | |
4313 | return 0; | |
906c4e36 | 4314 | val = (unsigned HOST_WIDE_INT) arg0 / arg1; |
7afe21cc RK |
4315 | break; |
4316 | ||
4317 | case UMOD: | |
4318 | if (arg1 == 0) | |
4319 | return 0; | |
906c4e36 | 4320 | val = (unsigned HOST_WIDE_INT) arg0 % arg1; |
7afe21cc RK |
4321 | break; |
4322 | ||
4323 | case AND: | |
4324 | val = arg0 & arg1; | |
4325 | break; | |
4326 | ||
4327 | case IOR: | |
4328 | val = arg0 | arg1; | |
4329 | break; | |
4330 | ||
4331 | case XOR: | |
4332 | val = arg0 ^ arg1; | |
4333 | break; | |
4334 | ||
4335 | case LSHIFTRT: | |
4336 | /* If shift count is undefined, don't fold it; let the machine do | |
4337 | what it wants. But truncate it if the machine will do that. */ | |
4338 | if (arg1 < 0) | |
4339 | return 0; | |
4340 | ||
4341 | #ifdef SHIFT_COUNT_TRUNCATED | |
85c0a556 | 4342 | if (SHIFT_COUNT_TRUNCATED) |
4d61f8c5 | 4343 | arg1 %= width; |
7afe21cc RK |
4344 | #endif |
4345 | ||
906c4e36 | 4346 | val = ((unsigned HOST_WIDE_INT) arg0) >> arg1; |
7afe21cc RK |
4347 | break; |
4348 | ||
4349 | case ASHIFT: | |
7afe21cc RK |
4350 | if (arg1 < 0) |
4351 | return 0; | |
4352 | ||
4353 | #ifdef SHIFT_COUNT_TRUNCATED | |
85c0a556 | 4354 | if (SHIFT_COUNT_TRUNCATED) |
4d61f8c5 | 4355 | arg1 %= width; |
7afe21cc RK |
4356 | #endif |
4357 | ||
906c4e36 | 4358 | val = ((unsigned HOST_WIDE_INT) arg0) << arg1; |
7afe21cc RK |
4359 | break; |
4360 | ||
4361 | case ASHIFTRT: | |
4362 | if (arg1 < 0) | |
4363 | return 0; | |
4364 | ||
4365 | #ifdef SHIFT_COUNT_TRUNCATED | |
85c0a556 | 4366 | if (SHIFT_COUNT_TRUNCATED) |
4d61f8c5 | 4367 | arg1 %= width; |
7afe21cc RK |
4368 | #endif |
4369 | ||
7afe21cc | 4370 | val = arg0s >> arg1; |
2166571b RS |
4371 | |
4372 | /* Bootstrap compiler may not have sign extended the right shift. | |
4373 | Manually extend the sign to insure bootstrap cc matches gcc. */ | |
4374 | if (arg0s < 0 && arg1 > 0) | |
4375 | val |= ((HOST_WIDE_INT) -1) << (HOST_BITS_PER_WIDE_INT - arg1); | |
4376 | ||
7afe21cc RK |
4377 | break; |
4378 | ||
4379 | case ROTATERT: | |
4380 | if (arg1 < 0) | |
4381 | return 0; | |
4382 | ||
4383 | arg1 %= width; | |
906c4e36 RK |
4384 | val = ((((unsigned HOST_WIDE_INT) arg0) << (width - arg1)) |
4385 | | (((unsigned HOST_WIDE_INT) arg0) >> arg1)); | |
7afe21cc RK |
4386 | break; |
4387 | ||
4388 | case ROTATE: | |
4389 | if (arg1 < 0) | |
4390 | return 0; | |
4391 | ||
4392 | arg1 %= width; | |
906c4e36 RK |
4393 | val = ((((unsigned HOST_WIDE_INT) arg0) << arg1) |
4394 | | (((unsigned HOST_WIDE_INT) arg0) >> (width - arg1))); | |
7afe21cc RK |
4395 | break; |
4396 | ||
4397 | case COMPARE: | |
4398 | /* Do nothing here. */ | |
4399 | return 0; | |
4400 | ||
830a38ee RS |
4401 | case SMIN: |
4402 | val = arg0s <= arg1s ? arg0s : arg1s; | |
4403 | break; | |
4404 | ||
4405 | case UMIN: | |
906c4e36 RK |
4406 | val = ((unsigned HOST_WIDE_INT) arg0 |
4407 | <= (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1); | |
830a38ee RS |
4408 | break; |
4409 | ||
4410 | case SMAX: | |
4411 | val = arg0s > arg1s ? arg0s : arg1s; | |
4412 | break; | |
4413 | ||
4414 | case UMAX: | |
906c4e36 RK |
4415 | val = ((unsigned HOST_WIDE_INT) arg0 |
4416 | > (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1); | |
830a38ee RS |
4417 | break; |
4418 | ||
7afe21cc RK |
4419 | default: |
4420 | abort (); | |
4421 | } | |
4422 | ||
7e4ce834 | 4423 | val = trunc_int_for_mode (val, mode); |
ad89d6f6 | 4424 | |
906c4e36 | 4425 | return GEN_INT (val); |
7afe21cc RK |
4426 | } |
4427 | \f | |
96b0e481 RK |
4428 | /* Simplify a PLUS or MINUS, at least one of whose operands may be another |
4429 | PLUS or MINUS. | |
4430 | ||
4431 | Rather than test for specific case, we do this by a brute-force method | |
4432 | and do all possible simplifications until no more changes occur. Then | |
4433 | we rebuild the operation. */ | |
4434 | ||
4435 | static rtx | |
4436 | simplify_plus_minus (code, mode, op0, op1) | |
4437 | enum rtx_code code; | |
4438 | enum machine_mode mode; | |
4439 | rtx op0, op1; | |
4440 | { | |
4441 | rtx ops[8]; | |
4442 | int negs[8]; | |
4443 | rtx result, tem; | |
fb5c8ce6 | 4444 | int n_ops = 2, input_ops = 2, input_consts = 0, n_consts = 0; |
96b0e481 | 4445 | int first = 1, negate = 0, changed; |
fb5c8ce6 | 4446 | int i, j; |
96b0e481 | 4447 | |
4c9a05bc | 4448 | bzero ((char *) ops, sizeof ops); |
96b0e481 RK |
4449 | |
4450 | /* Set up the two operands and then expand them until nothing has been | |
4451 | changed. If we run out of room in our array, give up; this should | |
4452 | almost never happen. */ | |
4453 | ||
4454 | ops[0] = op0, ops[1] = op1, negs[0] = 0, negs[1] = (code == MINUS); | |
4455 | ||
4456 | changed = 1; | |
4457 | while (changed) | |
4458 | { | |
4459 | changed = 0; | |
4460 | ||
4461 | for (i = 0; i < n_ops; i++) | |
4462 | switch (GET_CODE (ops[i])) | |
4463 | { | |
4464 | case PLUS: | |
4465 | case MINUS: | |
4466 | if (n_ops == 7) | |
4467 | return 0; | |
4468 | ||
4469 | ops[n_ops] = XEXP (ops[i], 1); | |
4470 | negs[n_ops++] = GET_CODE (ops[i]) == MINUS ? !negs[i] : negs[i]; | |
4471 | ops[i] = XEXP (ops[i], 0); | |
b7d9299b | 4472 | input_ops++; |
96b0e481 RK |
4473 | changed = 1; |
4474 | break; | |
4475 | ||
4476 | case NEG: | |
4477 | ops[i] = XEXP (ops[i], 0); | |
4478 | negs[i] = ! negs[i]; | |
4479 | changed = 1; | |
4480 | break; | |
4481 | ||
4482 | case CONST: | |
4483 | ops[i] = XEXP (ops[i], 0); | |
fb5c8ce6 | 4484 | input_consts++; |
96b0e481 RK |
4485 | changed = 1; |
4486 | break; | |
4487 | ||
4488 | case NOT: | |
4489 | /* ~a -> (-a - 1) */ | |
4490 | if (n_ops != 7) | |
4491 | { | |
4492 | ops[n_ops] = constm1_rtx; | |
5931019b | 4493 | negs[n_ops++] = negs[i]; |
96b0e481 RK |
4494 | ops[i] = XEXP (ops[i], 0); |
4495 | negs[i] = ! negs[i]; | |
4496 | changed = 1; | |
4497 | } | |
4498 | break; | |
4499 | ||
4500 | case CONST_INT: | |
4501 | if (negs[i]) | |
4502 | ops[i] = GEN_INT (- INTVAL (ops[i])), negs[i] = 0, changed = 1; | |
4503 | break; | |
e9a25f70 JL |
4504 | |
4505 | default: | |
4506 | break; | |
96b0e481 RK |
4507 | } |
4508 | } | |
4509 | ||
4510 | /* If we only have two operands, we can't do anything. */ | |
4511 | if (n_ops <= 2) | |
4512 | return 0; | |
4513 | ||
4514 | /* Now simplify each pair of operands until nothing changes. The first | |
4515 | time through just simplify constants against each other. */ | |
4516 | ||
4517 | changed = 1; | |
4518 | while (changed) | |
4519 | { | |
4520 | changed = first; | |
4521 | ||
4522 | for (i = 0; i < n_ops - 1; i++) | |
4523 | for (j = i + 1; j < n_ops; j++) | |
4524 | if (ops[i] != 0 && ops[j] != 0 | |
4525 | && (! first || (CONSTANT_P (ops[i]) && CONSTANT_P (ops[j])))) | |
4526 | { | |
4527 | rtx lhs = ops[i], rhs = ops[j]; | |
4528 | enum rtx_code ncode = PLUS; | |
4529 | ||
4530 | if (negs[i] && ! negs[j]) | |
4531 | lhs = ops[j], rhs = ops[i], ncode = MINUS; | |
4532 | else if (! negs[i] && negs[j]) | |
4533 | ncode = MINUS; | |
4534 | ||
4535 | tem = simplify_binary_operation (ncode, mode, lhs, rhs); | |
b7d9299b | 4536 | if (tem) |
96b0e481 RK |
4537 | { |
4538 | ops[i] = tem, ops[j] = 0; | |
4539 | negs[i] = negs[i] && negs[j]; | |
4540 | if (GET_CODE (tem) == NEG) | |
4541 | ops[i] = XEXP (tem, 0), negs[i] = ! negs[i]; | |
4542 | ||
4543 | if (GET_CODE (ops[i]) == CONST_INT && negs[i]) | |
4544 | ops[i] = GEN_INT (- INTVAL (ops[i])), negs[i] = 0; | |
4545 | changed = 1; | |
4546 | } | |
4547 | } | |
4548 | ||
4549 | first = 0; | |
4550 | } | |
4551 | ||
4552 | /* Pack all the operands to the lower-numbered entries and give up if | |
91a60f37 | 4553 | we didn't reduce the number of operands we had. Make sure we |
fb5c8ce6 RK |
4554 | count a CONST as two operands. If we have the same number of |
4555 | operands, but have made more CONSTs than we had, this is also | |
4556 | an improvement, so accept it. */ | |
91a60f37 | 4557 | |
fb5c8ce6 | 4558 | for (i = 0, j = 0; j < n_ops; j++) |
96b0e481 | 4559 | if (ops[j] != 0) |
91a60f37 RK |
4560 | { |
4561 | ops[i] = ops[j], negs[i++] = negs[j]; | |
4562 | if (GET_CODE (ops[j]) == CONST) | |
fb5c8ce6 | 4563 | n_consts++; |
91a60f37 | 4564 | } |
96b0e481 | 4565 | |
fb5c8ce6 RK |
4566 | if (i + n_consts > input_ops |
4567 | || (i + n_consts == input_ops && n_consts <= input_consts)) | |
96b0e481 RK |
4568 | return 0; |
4569 | ||
4570 | n_ops = i; | |
4571 | ||
4572 | /* If we have a CONST_INT, put it last. */ | |
4573 | for (i = 0; i < n_ops - 1; i++) | |
4574 | if (GET_CODE (ops[i]) == CONST_INT) | |
4575 | { | |
4576 | tem = ops[n_ops - 1], ops[n_ops - 1] = ops[i] , ops[i] = tem; | |
4577 | j = negs[n_ops - 1], negs[n_ops - 1] = negs[i], negs[i] = j; | |
4578 | } | |
4579 | ||
4580 | /* Put a non-negated operand first. If there aren't any, make all | |
4581 | operands positive and negate the whole thing later. */ | |
4582 | for (i = 0; i < n_ops && negs[i]; i++) | |
4583 | ; | |
4584 | ||
4585 | if (i == n_ops) | |
4586 | { | |
4587 | for (i = 0; i < n_ops; i++) | |
4588 | negs[i] = 0; | |
4589 | negate = 1; | |
4590 | } | |
4591 | else if (i != 0) | |
4592 | { | |
4593 | tem = ops[0], ops[0] = ops[i], ops[i] = tem; | |
4594 | j = negs[0], negs[0] = negs[i], negs[i] = j; | |
4595 | } | |
4596 | ||
4597 | /* Now make the result by performing the requested operations. */ | |
4598 | result = ops[0]; | |
4599 | for (i = 1; i < n_ops; i++) | |
4600 | result = cse_gen_binary (negs[i] ? MINUS : PLUS, mode, result, ops[i]); | |
4601 | ||
38a448ca | 4602 | return negate ? gen_rtx_NEG (mode, result) : result; |
96b0e481 RK |
4603 | } |
4604 | \f | |
4605 | /* Make a binary operation by properly ordering the operands and | |
4606 | seeing if the expression folds. */ | |
4607 | ||
4608 | static rtx | |
4609 | cse_gen_binary (code, mode, op0, op1) | |
4610 | enum rtx_code code; | |
4611 | enum machine_mode mode; | |
4612 | rtx op0, op1; | |
4613 | { | |
4614 | rtx tem; | |
4615 | ||
4616 | /* Put complex operands first and constants second if commutative. */ | |
4617 | if (GET_RTX_CLASS (code) == 'c' | |
4618 | && ((CONSTANT_P (op0) && GET_CODE (op1) != CONST_INT) | |
4619 | || (GET_RTX_CLASS (GET_CODE (op0)) == 'o' | |
4620 | && GET_RTX_CLASS (GET_CODE (op1)) != 'o') | |
4621 | || (GET_CODE (op0) == SUBREG | |
4622 | && GET_RTX_CLASS (GET_CODE (SUBREG_REG (op0))) == 'o' | |
4623 | && GET_RTX_CLASS (GET_CODE (op1)) != 'o'))) | |
4624 | tem = op0, op0 = op1, op1 = tem; | |
4625 | ||
4626 | /* If this simplifies, do it. */ | |
4627 | tem = simplify_binary_operation (code, mode, op0, op1); | |
4628 | ||
4629 | if (tem) | |
4630 | return tem; | |
4631 | ||
4632 | /* Handle addition and subtraction of CONST_INT specially. Otherwise, | |
4633 | just form the operation. */ | |
4634 | ||
4635 | if (code == PLUS && GET_CODE (op1) == CONST_INT | |
4636 | && GET_MODE (op0) != VOIDmode) | |
4637 | return plus_constant (op0, INTVAL (op1)); | |
4638 | else if (code == MINUS && GET_CODE (op1) == CONST_INT | |
4639 | && GET_MODE (op0) != VOIDmode) | |
4640 | return plus_constant (op0, - INTVAL (op1)); | |
4641 | else | |
38a448ca | 4642 | return gen_rtx_fmt_ee (code, mode, op0, op1); |
96b0e481 RK |
4643 | } |
4644 | \f | |
1a87eea2 KG |
4645 | struct cfc_args |
4646 | { | |
4647 | /* Input */ | |
4648 | rtx op0, op1; | |
4649 | /* Output */ | |
4650 | int equal, op0lt, op1lt; | |
4651 | }; | |
4652 | ||
4653 | static void | |
4654 | check_fold_consts (data) | |
4655 | PTR data; | |
4656 | { | |
4657 | struct cfc_args * args = (struct cfc_args *) data; | |
4658 | REAL_VALUE_TYPE d0, d1; | |
4659 | ||
4660 | REAL_VALUE_FROM_CONST_DOUBLE (d0, args->op0); | |
4661 | REAL_VALUE_FROM_CONST_DOUBLE (d1, args->op1); | |
4662 | args->equal = REAL_VALUES_EQUAL (d0, d1); | |
4663 | args->op0lt = REAL_VALUES_LESS (d0, d1); | |
4664 | args->op1lt = REAL_VALUES_LESS (d1, d0); | |
4665 | } | |
4666 | ||
7afe21cc | 4667 | /* Like simplify_binary_operation except used for relational operators. |
a432f20d RK |
4668 | MODE is the mode of the operands, not that of the result. If MODE |
4669 | is VOIDmode, both operands must also be VOIDmode and we compare the | |
4670 | operands in "infinite precision". | |
4671 | ||
4672 | If no simplification is possible, this function returns zero. Otherwise, | |
4673 | it returns either const_true_rtx or const0_rtx. */ | |
7afe21cc RK |
4674 | |
4675 | rtx | |
4676 | simplify_relational_operation (code, mode, op0, op1) | |
4677 | enum rtx_code code; | |
4678 | enum machine_mode mode; | |
4679 | rtx op0, op1; | |
4680 | { | |
a432f20d RK |
4681 | int equal, op0lt, op0ltu, op1lt, op1ltu; |
4682 | rtx tem; | |
7afe21cc RK |
4683 | |
4684 | /* If op0 is a compare, extract the comparison arguments from it. */ | |
4685 | if (GET_CODE (op0) == COMPARE && op1 == const0_rtx) | |
4686 | op1 = XEXP (op0, 1), op0 = XEXP (op0, 0); | |
4687 | ||
28bad1cb RK |
4688 | /* We can't simplify MODE_CC values since we don't know what the |
4689 | actual comparison is. */ | |
4690 | if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC | |
4691 | #ifdef HAVE_cc0 | |
4692 | || op0 == cc0_rtx | |
4693 | #endif | |
4694 | ) | |
31dcf83f RS |
4695 | return 0; |
4696 | ||
a432f20d RK |
4697 | /* For integer comparisons of A and B maybe we can simplify A - B and can |
4698 | then simplify a comparison of that with zero. If A and B are both either | |
4699 | a register or a CONST_INT, this can't help; testing for these cases will | |
4700 | prevent infinite recursion here and speed things up. | |
4701 | ||
c27b5c62 JW |
4702 | If CODE is an unsigned comparison, then we can never do this optimization, |
4703 | because it gives an incorrect result if the subtraction wraps around zero. | |
4704 | ANSI C defines unsigned operations such that they never overflow, and | |
4705 | thus such cases can not be ignored. */ | |
a432f20d RK |
4706 | |
4707 | if (INTEGRAL_MODE_P (mode) && op1 != const0_rtx | |
4708 | && ! ((GET_CODE (op0) == REG || GET_CODE (op0) == CONST_INT) | |
4709 | && (GET_CODE (op1) == REG || GET_CODE (op1) == CONST_INT)) | |
4710 | && 0 != (tem = simplify_binary_operation (MINUS, mode, op0, op1)) | |
c27b5c62 | 4711 | && code != GTU && code != GEU && code != LTU && code != LEU) |
a432f20d RK |
4712 | return simplify_relational_operation (signed_condition (code), |
4713 | mode, tem, const0_rtx); | |
4714 | ||
4715 | /* For non-IEEE floating-point, if the two operands are equal, we know the | |
4716 | result. */ | |
4717 | if (rtx_equal_p (op0, op1) | |
4718 | && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
4719 | || ! FLOAT_MODE_P (GET_MODE (op0)) || flag_fast_math)) | |
4720 | equal = 1, op0lt = 0, op0ltu = 0, op1lt = 0, op1ltu = 0; | |
4721 | ||
4722 | /* If the operands are floating-point constants, see if we can fold | |
4723 | the result. */ | |
6076248a | 4724 | #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) |
a432f20d RK |
4725 | else if (GET_CODE (op0) == CONST_DOUBLE && GET_CODE (op1) == CONST_DOUBLE |
4726 | && GET_MODE_CLASS (GET_MODE (op0)) == MODE_FLOAT) | |
4727 | { | |
1a87eea2 KG |
4728 | struct cfc_args args; |
4729 | ||
4730 | /* Setup input for check_fold_consts() */ | |
4731 | args.op0 = op0; | |
4732 | args.op1 = op1; | |
a432f20d | 4733 | |
1a87eea2 KG |
4734 | if (do_float_handler(check_fold_consts, (PTR) &args) == 0) |
4735 | /* We got an exception from check_fold_consts() */ | |
a432f20d | 4736 | return 0; |
7afe21cc | 4737 | |
1a87eea2 KG |
4738 | /* Receive output from check_fold_consts() */ |
4739 | equal = args.equal; | |
4740 | op0lt = op0ltu = args.op0lt; | |
4741 | op1lt = op1ltu = args.op1lt; | |
a432f20d RK |
4742 | } |
4743 | #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ | |
7afe21cc | 4744 | |
a432f20d RK |
4745 | /* Otherwise, see if the operands are both integers. */ |
4746 | else if ((GET_MODE_CLASS (mode) == MODE_INT || mode == VOIDmode) | |
4747 | && (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT) | |
4748 | && (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT)) | |
4749 | { | |
4750 | int width = GET_MODE_BITSIZE (mode); | |
64812ded RK |
4751 | HOST_WIDE_INT l0s, h0s, l1s, h1s; |
4752 | unsigned HOST_WIDE_INT l0u, h0u, l1u, h1u; | |
7afe21cc | 4753 | |
a432f20d RK |
4754 | /* Get the two words comprising each integer constant. */ |
4755 | if (GET_CODE (op0) == CONST_DOUBLE) | |
4756 | { | |
4757 | l0u = l0s = CONST_DOUBLE_LOW (op0); | |
4758 | h0u = h0s = CONST_DOUBLE_HIGH (op0); | |
7afe21cc | 4759 | } |
a432f20d | 4760 | else |
6076248a | 4761 | { |
a432f20d | 4762 | l0u = l0s = INTVAL (op0); |
cb3bb2a7 | 4763 | h0u = h0s = l0s < 0 ? -1 : 0; |
a432f20d | 4764 | } |
6076248a | 4765 | |
a432f20d RK |
4766 | if (GET_CODE (op1) == CONST_DOUBLE) |
4767 | { | |
4768 | l1u = l1s = CONST_DOUBLE_LOW (op1); | |
4769 | h1u = h1s = CONST_DOUBLE_HIGH (op1); | |
4770 | } | |
4771 | else | |
4772 | { | |
4773 | l1u = l1s = INTVAL (op1); | |
cb3bb2a7 | 4774 | h1u = h1s = l1s < 0 ? -1 : 0; |
a432f20d RK |
4775 | } |
4776 | ||
4777 | /* If WIDTH is nonzero and smaller than HOST_BITS_PER_WIDE_INT, | |
4778 | we have to sign or zero-extend the values. */ | |
4779 | if (width != 0 && width <= HOST_BITS_PER_WIDE_INT) | |
4780 | h0u = h1u = 0, h0s = l0s < 0 ? -1 : 0, h1s = l1s < 0 ? -1 : 0; | |
6076248a | 4781 | |
a432f20d RK |
4782 | if (width != 0 && width < HOST_BITS_PER_WIDE_INT) |
4783 | { | |
4784 | l0u &= ((HOST_WIDE_INT) 1 << width) - 1; | |
4785 | l1u &= ((HOST_WIDE_INT) 1 << width) - 1; | |
6076248a | 4786 | |
a432f20d RK |
4787 | if (l0s & ((HOST_WIDE_INT) 1 << (width - 1))) |
4788 | l0s |= ((HOST_WIDE_INT) (-1) << width); | |
6076248a | 4789 | |
a432f20d RK |
4790 | if (l1s & ((HOST_WIDE_INT) 1 << (width - 1))) |
4791 | l1s |= ((HOST_WIDE_INT) (-1) << width); | |
6076248a RK |
4792 | } |
4793 | ||
a432f20d RK |
4794 | equal = (h0u == h1u && l0u == l1u); |
4795 | op0lt = (h0s < h1s || (h0s == h1s && l0s < l1s)); | |
4796 | op1lt = (h1s < h0s || (h1s == h0s && l1s < l0s)); | |
4797 | op0ltu = (h0u < h1u || (h0u == h1u && l0u < l1u)); | |
4798 | op1ltu = (h1u < h0u || (h1u == h0u && l1u < l0u)); | |
4799 | } | |
4800 | ||
4801 | /* Otherwise, there are some code-specific tests we can make. */ | |
4802 | else | |
4803 | { | |
7afe21cc RK |
4804 | switch (code) |
4805 | { | |
4806 | case EQ: | |
a432f20d RK |
4807 | /* References to the frame plus a constant or labels cannot |
4808 | be zero, but a SYMBOL_REF can due to #pragma weak. */ | |
4809 | if (((NONZERO_BASE_PLUS_P (op0) && op1 == const0_rtx) | |
4810 | || GET_CODE (op0) == LABEL_REF) | |
1a7c818b | 4811 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
a432f20d RK |
4812 | /* On some machines, the ap reg can be 0 sometimes. */ |
4813 | && op0 != arg_pointer_rtx | |
7afe21cc | 4814 | #endif |
a432f20d RK |
4815 | ) |
4816 | return const0_rtx; | |
4817 | break; | |
7afe21cc RK |
4818 | |
4819 | case NE: | |
a432f20d RK |
4820 | if (((NONZERO_BASE_PLUS_P (op0) && op1 == const0_rtx) |
4821 | || GET_CODE (op0) == LABEL_REF) | |
1a7c818b | 4822 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
a432f20d | 4823 | && op0 != arg_pointer_rtx |
7afe21cc | 4824 | #endif |
a432f20d | 4825 | ) |
7afe21cc RK |
4826 | return const_true_rtx; |
4827 | break; | |
4828 | ||
4829 | case GEU: | |
a432f20d RK |
4830 | /* Unsigned values are never negative. */ |
4831 | if (op1 == const0_rtx) | |
7afe21cc RK |
4832 | return const_true_rtx; |
4833 | break; | |
4834 | ||
4835 | case LTU: | |
a432f20d | 4836 | if (op1 == const0_rtx) |
7afe21cc RK |
4837 | return const0_rtx; |
4838 | break; | |
4839 | ||
4840 | case LEU: | |
4841 | /* Unsigned values are never greater than the largest | |
4842 | unsigned value. */ | |
4843 | if (GET_CODE (op1) == CONST_INT | |
4844 | && INTVAL (op1) == GET_MODE_MASK (mode) | |
a432f20d RK |
4845 | && INTEGRAL_MODE_P (mode)) |
4846 | return const_true_rtx; | |
7afe21cc RK |
4847 | break; |
4848 | ||
4849 | case GTU: | |
4850 | if (GET_CODE (op1) == CONST_INT | |
4851 | && INTVAL (op1) == GET_MODE_MASK (mode) | |
cbf6a543 | 4852 | && INTEGRAL_MODE_P (mode)) |
7afe21cc RK |
4853 | return const0_rtx; |
4854 | break; | |
e9a25f70 JL |
4855 | |
4856 | default: | |
4857 | break; | |
7afe21cc RK |
4858 | } |
4859 | ||
4860 | return 0; | |
4861 | } | |
4862 | ||
a432f20d RK |
4863 | /* If we reach here, EQUAL, OP0LT, OP0LTU, OP1LT, and OP1LTU are set |
4864 | as appropriate. */ | |
7afe21cc RK |
4865 | switch (code) |
4866 | { | |
7afe21cc | 4867 | case EQ: |
a432f20d RK |
4868 | return equal ? const_true_rtx : const0_rtx; |
4869 | case NE: | |
4870 | return ! equal ? const_true_rtx : const0_rtx; | |
7afe21cc | 4871 | case LT: |
a432f20d | 4872 | return op0lt ? const_true_rtx : const0_rtx; |
7afe21cc | 4873 | case GT: |
a432f20d | 4874 | return op1lt ? const_true_rtx : const0_rtx; |
7afe21cc | 4875 | case LTU: |
a432f20d | 4876 | return op0ltu ? const_true_rtx : const0_rtx; |
7afe21cc | 4877 | case GTU: |
a432f20d RK |
4878 | return op1ltu ? const_true_rtx : const0_rtx; |
4879 | case LE: | |
4880 | return equal || op0lt ? const_true_rtx : const0_rtx; | |
4881 | case GE: | |
4882 | return equal || op1lt ? const_true_rtx : const0_rtx; | |
4883 | case LEU: | |
4884 | return equal || op0ltu ? const_true_rtx : const0_rtx; | |
4885 | case GEU: | |
4886 | return equal || op1ltu ? const_true_rtx : const0_rtx; | |
e9a25f70 JL |
4887 | default: |
4888 | abort (); | |
7afe21cc | 4889 | } |
7afe21cc RK |
4890 | } |
4891 | \f | |
4892 | /* Simplify CODE, an operation with result mode MODE and three operands, | |
4893 | OP0, OP1, and OP2. OP0_MODE was the mode of OP0 before it became | |
4894 | a constant. Return 0 if no simplifications is possible. */ | |
4895 | ||
4896 | rtx | |
4897 | simplify_ternary_operation (code, mode, op0_mode, op0, op1, op2) | |
4898 | enum rtx_code code; | |
4899 | enum machine_mode mode, op0_mode; | |
4900 | rtx op0, op1, op2; | |
4901 | { | |
4902 | int width = GET_MODE_BITSIZE (mode); | |
4903 | ||
4904 | /* VOIDmode means "infinite" precision. */ | |
4905 | if (width == 0) | |
906c4e36 | 4906 | width = HOST_BITS_PER_WIDE_INT; |
7afe21cc RK |
4907 | |
4908 | switch (code) | |
4909 | { | |
4910 | case SIGN_EXTRACT: | |
4911 | case ZERO_EXTRACT: | |
4912 | if (GET_CODE (op0) == CONST_INT | |
4913 | && GET_CODE (op1) == CONST_INT | |
4914 | && GET_CODE (op2) == CONST_INT | |
4915 | && INTVAL (op1) + INTVAL (op2) <= GET_MODE_BITSIZE (op0_mode) | |
906c4e36 | 4916 | && width <= HOST_BITS_PER_WIDE_INT) |
7afe21cc RK |
4917 | { |
4918 | /* Extracting a bit-field from a constant */ | |
906c4e36 | 4919 | HOST_WIDE_INT val = INTVAL (op0); |
7afe21cc | 4920 | |
f76b9db2 ILT |
4921 | if (BITS_BIG_ENDIAN) |
4922 | val >>= (GET_MODE_BITSIZE (op0_mode) | |
4923 | - INTVAL (op2) - INTVAL (op1)); | |
4924 | else | |
4925 | val >>= INTVAL (op2); | |
4926 | ||
906c4e36 | 4927 | if (HOST_BITS_PER_WIDE_INT != INTVAL (op1)) |
7afe21cc RK |
4928 | { |
4929 | /* First zero-extend. */ | |
906c4e36 | 4930 | val &= ((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1; |
7afe21cc | 4931 | /* If desired, propagate sign bit. */ |
906c4e36 RK |
4932 | if (code == SIGN_EXTRACT |
4933 | && (val & ((HOST_WIDE_INT) 1 << (INTVAL (op1) - 1)))) | |
4934 | val |= ~ (((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1); | |
7afe21cc RK |
4935 | } |
4936 | ||
4937 | /* Clear the bits that don't belong in our mode, | |
4938 | unless they and our sign bit are all one. | |
4939 | So we get either a reasonable negative value or a reasonable | |
4940 | unsigned value for this mode. */ | |
906c4e36 RK |
4941 | if (width < HOST_BITS_PER_WIDE_INT |
4942 | && ((val & ((HOST_WIDE_INT) (-1) << (width - 1))) | |
4943 | != ((HOST_WIDE_INT) (-1) << (width - 1)))) | |
4944 | val &= ((HOST_WIDE_INT) 1 << width) - 1; | |
7afe21cc | 4945 | |
906c4e36 | 4946 | return GEN_INT (val); |
7afe21cc RK |
4947 | } |
4948 | break; | |
4949 | ||
4950 | case IF_THEN_ELSE: | |
4951 | if (GET_CODE (op0) == CONST_INT) | |
4952 | return op0 != const0_rtx ? op1 : op2; | |
3bf1b082 JW |
4953 | |
4954 | /* Convert a == b ? b : a to "a". */ | |
4955 | if (GET_CODE (op0) == NE && ! side_effects_p (op0) | |
4956 | && rtx_equal_p (XEXP (op0, 0), op1) | |
4957 | && rtx_equal_p (XEXP (op0, 1), op2)) | |
4958 | return op1; | |
4959 | else if (GET_CODE (op0) == EQ && ! side_effects_p (op0) | |
4960 | && rtx_equal_p (XEXP (op0, 1), op1) | |
4961 | && rtx_equal_p (XEXP (op0, 0), op2)) | |
4962 | return op2; | |
e82ad93d | 4963 | else if (GET_RTX_CLASS (GET_CODE (op0)) == '<' && ! side_effects_p (op0)) |
ed1ecb19 JL |
4964 | { |
4965 | rtx temp; | |
4966 | temp = simplify_relational_operation (GET_CODE (op0), op0_mode, | |
4967 | XEXP (op0, 0), XEXP (op0, 1)); | |
4968 | /* See if any simplifications were possible. */ | |
4969 | if (temp == const0_rtx) | |
4970 | return op2; | |
4971 | else if (temp == const1_rtx) | |
4972 | return op1; | |
4973 | } | |
7afe21cc RK |
4974 | break; |
4975 | ||
4976 | default: | |
4977 | abort (); | |
4978 | } | |
4979 | ||
4980 | return 0; | |
4981 | } | |
4982 | \f | |
4983 | /* If X is a nontrivial arithmetic operation on an argument | |
4984 | for which a constant value can be determined, return | |
4985 | the result of operating on that value, as a constant. | |
4986 | Otherwise, return X, possibly with one or more operands | |
4987 | modified by recursive calls to this function. | |
4988 | ||
e7bb59fa RK |
4989 | If X is a register whose contents are known, we do NOT |
4990 | return those contents here. equiv_constant is called to | |
4991 | perform that task. | |
7afe21cc RK |
4992 | |
4993 | INSN is the insn that we may be modifying. If it is 0, make a copy | |
4994 | of X before modifying it. */ | |
4995 | ||
4996 | static rtx | |
4997 | fold_rtx (x, insn) | |
4998 | rtx x; | |
4999 | rtx insn; | |
5000 | { | |
5001 | register enum rtx_code code; | |
5002 | register enum machine_mode mode; | |
5003 | register char *fmt; | |
906c4e36 | 5004 | register int i; |
7afe21cc RK |
5005 | rtx new = 0; |
5006 | int copied = 0; | |
5007 | int must_swap = 0; | |
5008 | ||
5009 | /* Folded equivalents of first two operands of X. */ | |
5010 | rtx folded_arg0; | |
5011 | rtx folded_arg1; | |
5012 | ||
5013 | /* Constant equivalents of first three operands of X; | |
5014 | 0 when no such equivalent is known. */ | |
5015 | rtx const_arg0; | |
5016 | rtx const_arg1; | |
5017 | rtx const_arg2; | |
5018 | ||
5019 | /* The mode of the first operand of X. We need this for sign and zero | |
5020 | extends. */ | |
5021 | enum machine_mode mode_arg0; | |
5022 | ||
5023 | if (x == 0) | |
5024 | return x; | |
5025 | ||
5026 | mode = GET_MODE (x); | |
5027 | code = GET_CODE (x); | |
5028 | switch (code) | |
5029 | { | |
5030 | case CONST: | |
5031 | case CONST_INT: | |
5032 | case CONST_DOUBLE: | |
5033 | case SYMBOL_REF: | |
5034 | case LABEL_REF: | |
5035 | case REG: | |
5036 | /* No use simplifying an EXPR_LIST | |
5037 | since they are used only for lists of args | |
5038 | in a function call's REG_EQUAL note. */ | |
5039 | case EXPR_LIST: | |
956d6950 JL |
5040 | /* Changing anything inside an ADDRESSOF is incorrect; we don't |
5041 | want to (e.g.,) make (addressof (const_int 0)) just because | |
5042 | the location is known to be zero. */ | |
5043 | case ADDRESSOF: | |
7afe21cc RK |
5044 | return x; |
5045 | ||
5046 | #ifdef HAVE_cc0 | |
5047 | case CC0: | |
5048 | return prev_insn_cc0; | |
5049 | #endif | |
5050 | ||
5051 | case PC: | |
5052 | /* If the next insn is a CODE_LABEL followed by a jump table, | |
5053 | PC's value is a LABEL_REF pointing to that label. That | |
5054 | lets us fold switch statements on the Vax. */ | |
5055 | if (insn && GET_CODE (insn) == JUMP_INSN) | |
5056 | { | |
5057 | rtx next = next_nonnote_insn (insn); | |
5058 | ||
5059 | if (next && GET_CODE (next) == CODE_LABEL | |
5060 | && NEXT_INSN (next) != 0 | |
5061 | && GET_CODE (NEXT_INSN (next)) == JUMP_INSN | |
5062 | && (GET_CODE (PATTERN (NEXT_INSN (next))) == ADDR_VEC | |
5063 | || GET_CODE (PATTERN (NEXT_INSN (next))) == ADDR_DIFF_VEC)) | |
38a448ca | 5064 | return gen_rtx_LABEL_REF (Pmode, next); |
7afe21cc RK |
5065 | } |
5066 | break; | |
5067 | ||
5068 | case SUBREG: | |
c610adec RK |
5069 | /* See if we previously assigned a constant value to this SUBREG. */ |
5070 | if ((new = lookup_as_function (x, CONST_INT)) != 0 | |
5071 | || (new = lookup_as_function (x, CONST_DOUBLE)) != 0) | |
7afe21cc RK |
5072 | return new; |
5073 | ||
4b980e20 RK |
5074 | /* If this is a paradoxical SUBREG, we have no idea what value the |
5075 | extra bits would have. However, if the operand is equivalent | |
5076 | to a SUBREG whose operand is the same as our mode, and all the | |
5077 | modes are within a word, we can just use the inner operand | |
31c85c78 RK |
5078 | because these SUBREGs just say how to treat the register. |
5079 | ||
5080 | Similarly if we find an integer constant. */ | |
4b980e20 | 5081 | |
e5f6a288 | 5082 | if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) |
4b980e20 RK |
5083 | { |
5084 | enum machine_mode imode = GET_MODE (SUBREG_REG (x)); | |
5085 | struct table_elt *elt; | |
5086 | ||
5087 | if (GET_MODE_SIZE (mode) <= UNITS_PER_WORD | |
5088 | && GET_MODE_SIZE (imode) <= UNITS_PER_WORD | |
5089 | && (elt = lookup (SUBREG_REG (x), HASH (SUBREG_REG (x), imode), | |
5090 | imode)) != 0) | |
31c85c78 RK |
5091 | for (elt = elt->first_same_value; |
5092 | elt; elt = elt->next_same_value) | |
5093 | { | |
5094 | if (CONSTANT_P (elt->exp) | |
5095 | && GET_MODE (elt->exp) == VOIDmode) | |
5096 | return elt->exp; | |
5097 | ||
4b980e20 RK |
5098 | if (GET_CODE (elt->exp) == SUBREG |
5099 | && GET_MODE (SUBREG_REG (elt->exp)) == mode | |
906c4e36 | 5100 | && exp_equiv_p (elt->exp, elt->exp, 1, 0)) |
4b980e20 RK |
5101 | return copy_rtx (SUBREG_REG (elt->exp)); |
5102 | } | |
5103 | ||
5104 | return x; | |
5105 | } | |
e5f6a288 | 5106 | |
7afe21cc RK |
5107 | /* Fold SUBREG_REG. If it changed, see if we can simplify the SUBREG. |
5108 | We might be able to if the SUBREG is extracting a single word in an | |
5109 | integral mode or extracting the low part. */ | |
5110 | ||
5111 | folded_arg0 = fold_rtx (SUBREG_REG (x), insn); | |
5112 | const_arg0 = equiv_constant (folded_arg0); | |
5113 | if (const_arg0) | |
5114 | folded_arg0 = const_arg0; | |
5115 | ||
5116 | if (folded_arg0 != SUBREG_REG (x)) | |
5117 | { | |
5118 | new = 0; | |
5119 | ||
5120 | if (GET_MODE_CLASS (mode) == MODE_INT | |
5121 | && GET_MODE_SIZE (mode) == UNITS_PER_WORD | |
5122 | && GET_MODE (SUBREG_REG (x)) != VOIDmode) | |
5123 | new = operand_subword (folded_arg0, SUBREG_WORD (x), 0, | |
5124 | GET_MODE (SUBREG_REG (x))); | |
5125 | if (new == 0 && subreg_lowpart_p (x)) | |
5126 | new = gen_lowpart_if_possible (mode, folded_arg0); | |
5127 | if (new) | |
5128 | return new; | |
5129 | } | |
e5f6a288 RK |
5130 | |
5131 | /* If this is a narrowing SUBREG and our operand is a REG, see if | |
858a47b1 | 5132 | we can find an equivalence for REG that is an arithmetic operation |
e5f6a288 RK |
5133 | in a wider mode where both operands are paradoxical SUBREGs |
5134 | from objects of our result mode. In that case, we couldn't report | |
5135 | an equivalent value for that operation, since we don't know what the | |
5136 | extra bits will be. But we can find an equivalence for this SUBREG | |
5137 | by folding that operation is the narrow mode. This allows us to | |
5138 | fold arithmetic in narrow modes when the machine only supports | |
4b980e20 RK |
5139 | word-sized arithmetic. |
5140 | ||
5141 | Also look for a case where we have a SUBREG whose operand is the | |
5142 | same as our result. If both modes are smaller than a word, we | |
5143 | are simply interpreting a register in different modes and we | |
5144 | can use the inner value. */ | |
e5f6a288 RK |
5145 | |
5146 | if (GET_CODE (folded_arg0) == REG | |
e8d76a39 RS |
5147 | && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (folded_arg0)) |
5148 | && subreg_lowpart_p (x)) | |
e5f6a288 RK |
5149 | { |
5150 | struct table_elt *elt; | |
5151 | ||
5152 | /* We can use HASH here since we know that canon_hash won't be | |
5153 | called. */ | |
5154 | elt = lookup (folded_arg0, | |
5155 | HASH (folded_arg0, GET_MODE (folded_arg0)), | |
5156 | GET_MODE (folded_arg0)); | |
5157 | ||
5158 | if (elt) | |
5159 | elt = elt->first_same_value; | |
5160 | ||
5161 | for (; elt; elt = elt->next_same_value) | |
5162 | { | |
e8d76a39 RS |
5163 | enum rtx_code eltcode = GET_CODE (elt->exp); |
5164 | ||
e5f6a288 RK |
5165 | /* Just check for unary and binary operations. */ |
5166 | if (GET_RTX_CLASS (GET_CODE (elt->exp)) == '1' | |
5167 | && GET_CODE (elt->exp) != SIGN_EXTEND | |
5168 | && GET_CODE (elt->exp) != ZERO_EXTEND | |
5169 | && GET_CODE (XEXP (elt->exp, 0)) == SUBREG | |
5170 | && GET_MODE (SUBREG_REG (XEXP (elt->exp, 0))) == mode) | |
5171 | { | |
5172 | rtx op0 = SUBREG_REG (XEXP (elt->exp, 0)); | |
5173 | ||
5174 | if (GET_CODE (op0) != REG && ! CONSTANT_P (op0)) | |
906c4e36 | 5175 | op0 = fold_rtx (op0, NULL_RTX); |
e5f6a288 RK |
5176 | |
5177 | op0 = equiv_constant (op0); | |
5178 | if (op0) | |
5179 | new = simplify_unary_operation (GET_CODE (elt->exp), mode, | |
5180 | op0, mode); | |
5181 | } | |
5182 | else if ((GET_RTX_CLASS (GET_CODE (elt->exp)) == '2' | |
5183 | || GET_RTX_CLASS (GET_CODE (elt->exp)) == 'c') | |
e8d76a39 RS |
5184 | && eltcode != DIV && eltcode != MOD |
5185 | && eltcode != UDIV && eltcode != UMOD | |
5186 | && eltcode != ASHIFTRT && eltcode != LSHIFTRT | |
5187 | && eltcode != ROTATE && eltcode != ROTATERT | |
e5f6a288 RK |
5188 | && ((GET_CODE (XEXP (elt->exp, 0)) == SUBREG |
5189 | && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 0))) | |
5190 | == mode)) | |
5191 | || CONSTANT_P (XEXP (elt->exp, 0))) | |
5192 | && ((GET_CODE (XEXP (elt->exp, 1)) == SUBREG | |
5193 | && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 1))) | |
5194 | == mode)) | |
5195 | || CONSTANT_P (XEXP (elt->exp, 1)))) | |
5196 | { | |
5197 | rtx op0 = gen_lowpart_common (mode, XEXP (elt->exp, 0)); | |
5198 | rtx op1 = gen_lowpart_common (mode, XEXP (elt->exp, 1)); | |
5199 | ||
5200 | if (op0 && GET_CODE (op0) != REG && ! CONSTANT_P (op0)) | |
906c4e36 | 5201 | op0 = fold_rtx (op0, NULL_RTX); |
e5f6a288 RK |
5202 | |
5203 | if (op0) | |
5204 | op0 = equiv_constant (op0); | |
5205 | ||
5206 | if (op1 && GET_CODE (op1) != REG && ! CONSTANT_P (op1)) | |
906c4e36 | 5207 | op1 = fold_rtx (op1, NULL_RTX); |
e5f6a288 RK |
5208 | |
5209 | if (op1) | |
5210 | op1 = equiv_constant (op1); | |
5211 | ||
76fb0b60 RS |
5212 | /* If we are looking for the low SImode part of |
5213 | (ashift:DI c (const_int 32)), it doesn't work | |
5214 | to compute that in SImode, because a 32-bit shift | |
5215 | in SImode is unpredictable. We know the value is 0. */ | |
5216 | if (op0 && op1 | |
45620ed4 | 5217 | && GET_CODE (elt->exp) == ASHIFT |
76fb0b60 RS |
5218 | && GET_CODE (op1) == CONST_INT |
5219 | && INTVAL (op1) >= GET_MODE_BITSIZE (mode)) | |
5220 | { | |
5221 | if (INTVAL (op1) < GET_MODE_BITSIZE (GET_MODE (elt->exp))) | |
5222 | ||
5223 | /* If the count fits in the inner mode's width, | |
5224 | but exceeds the outer mode's width, | |
5225 | the value will get truncated to 0 | |
5226 | by the subreg. */ | |
5227 | new = const0_rtx; | |
5228 | else | |
5229 | /* If the count exceeds even the inner mode's width, | |
5230 | don't fold this expression. */ | |
5231 | new = 0; | |
5232 | } | |
5233 | else if (op0 && op1) | |
e5f6a288 RK |
5234 | new = simplify_binary_operation (GET_CODE (elt->exp), mode, |
5235 | op0, op1); | |
5236 | } | |
5237 | ||
4b980e20 RK |
5238 | else if (GET_CODE (elt->exp) == SUBREG |
5239 | && GET_MODE (SUBREG_REG (elt->exp)) == mode | |
5240 | && (GET_MODE_SIZE (GET_MODE (folded_arg0)) | |
5241 | <= UNITS_PER_WORD) | |
906c4e36 | 5242 | && exp_equiv_p (elt->exp, elt->exp, 1, 0)) |
4b980e20 RK |
5243 | new = copy_rtx (SUBREG_REG (elt->exp)); |
5244 | ||
e5f6a288 RK |
5245 | if (new) |
5246 | return new; | |
5247 | } | |
5248 | } | |
5249 | ||
7afe21cc RK |
5250 | return x; |
5251 | ||
5252 | case NOT: | |
5253 | case NEG: | |
5254 | /* If we have (NOT Y), see if Y is known to be (NOT Z). | |
5255 | If so, (NOT Y) simplifies to Z. Similarly for NEG. */ | |
5256 | new = lookup_as_function (XEXP (x, 0), code); | |
5257 | if (new) | |
5258 | return fold_rtx (copy_rtx (XEXP (new, 0)), insn); | |
5259 | break; | |
13c9910f | 5260 | |
7afe21cc RK |
5261 | case MEM: |
5262 | /* If we are not actually processing an insn, don't try to find the | |
5263 | best address. Not only don't we care, but we could modify the | |
5264 | MEM in an invalid way since we have no insn to validate against. */ | |
5265 | if (insn != 0) | |
5266 | find_best_addr (insn, &XEXP (x, 0)); | |
5267 | ||
5268 | { | |
5269 | /* Even if we don't fold in the insn itself, | |
5270 | we can safely do so here, in hopes of getting a constant. */ | |
906c4e36 | 5271 | rtx addr = fold_rtx (XEXP (x, 0), NULL_RTX); |
7afe21cc | 5272 | rtx base = 0; |
906c4e36 | 5273 | HOST_WIDE_INT offset = 0; |
7afe21cc RK |
5274 | |
5275 | if (GET_CODE (addr) == REG | |
5276 | && REGNO_QTY_VALID_P (REGNO (addr)) | |
30f72379 MM |
5277 | && GET_MODE (addr) == qty_mode[REG_QTY (REGNO (addr))] |
5278 | && qty_const[REG_QTY (REGNO (addr))] != 0) | |
5279 | addr = qty_const[REG_QTY (REGNO (addr))]; | |
7afe21cc RK |
5280 | |
5281 | /* If address is constant, split it into a base and integer offset. */ | |
5282 | if (GET_CODE (addr) == SYMBOL_REF || GET_CODE (addr) == LABEL_REF) | |
5283 | base = addr; | |
5284 | else if (GET_CODE (addr) == CONST && GET_CODE (XEXP (addr, 0)) == PLUS | |
5285 | && GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT) | |
5286 | { | |
5287 | base = XEXP (XEXP (addr, 0), 0); | |
5288 | offset = INTVAL (XEXP (XEXP (addr, 0), 1)); | |
5289 | } | |
5290 | else if (GET_CODE (addr) == LO_SUM | |
5291 | && GET_CODE (XEXP (addr, 1)) == SYMBOL_REF) | |
5292 | base = XEXP (addr, 1); | |
e9a25f70 | 5293 | else if (GET_CODE (addr) == ADDRESSOF) |
956d6950 | 5294 | return change_address (x, VOIDmode, addr); |
7afe21cc RK |
5295 | |
5296 | /* If this is a constant pool reference, we can fold it into its | |
5297 | constant to allow better value tracking. */ | |
5298 | if (base && GET_CODE (base) == SYMBOL_REF | |
5299 | && CONSTANT_POOL_ADDRESS_P (base)) | |
5300 | { | |
5301 | rtx constant = get_pool_constant (base); | |
5302 | enum machine_mode const_mode = get_pool_mode (base); | |
5303 | rtx new; | |
5304 | ||
5305 | if (CONSTANT_P (constant) && GET_CODE (constant) != CONST_INT) | |
5306 | constant_pool_entries_cost = COST (constant); | |
5307 | ||
5308 | /* If we are loading the full constant, we have an equivalence. */ | |
5309 | if (offset == 0 && mode == const_mode) | |
5310 | return constant; | |
5311 | ||
9faa82d8 | 5312 | /* If this actually isn't a constant (weird!), we can't do |
7afe21cc RK |
5313 | anything. Otherwise, handle the two most common cases: |
5314 | extracting a word from a multi-word constant, and extracting | |
5315 | the low-order bits. Other cases don't seem common enough to | |
5316 | worry about. */ | |
5317 | if (! CONSTANT_P (constant)) | |
5318 | return x; | |
5319 | ||
5320 | if (GET_MODE_CLASS (mode) == MODE_INT | |
5321 | && GET_MODE_SIZE (mode) == UNITS_PER_WORD | |
5322 | && offset % UNITS_PER_WORD == 0 | |
5323 | && (new = operand_subword (constant, | |
5324 | offset / UNITS_PER_WORD, | |
5325 | 0, const_mode)) != 0) | |
5326 | return new; | |
5327 | ||
5328 | if (((BYTES_BIG_ENDIAN | |
5329 | && offset == GET_MODE_SIZE (GET_MODE (constant)) - 1) | |
5330 | || (! BYTES_BIG_ENDIAN && offset == 0)) | |
5331 | && (new = gen_lowpart_if_possible (mode, constant)) != 0) | |
5332 | return new; | |
5333 | } | |
5334 | ||
5335 | /* If this is a reference to a label at a known position in a jump | |
5336 | table, we also know its value. */ | |
5337 | if (base && GET_CODE (base) == LABEL_REF) | |
5338 | { | |
5339 | rtx label = XEXP (base, 0); | |
5340 | rtx table_insn = NEXT_INSN (label); | |
5341 | ||
5342 | if (table_insn && GET_CODE (table_insn) == JUMP_INSN | |
5343 | && GET_CODE (PATTERN (table_insn)) == ADDR_VEC) | |
5344 | { | |
5345 | rtx table = PATTERN (table_insn); | |
5346 | ||
5347 | if (offset >= 0 | |
5348 | && (offset / GET_MODE_SIZE (GET_MODE (table)) | |
5349 | < XVECLEN (table, 0))) | |
5350 | return XVECEXP (table, 0, | |
5351 | offset / GET_MODE_SIZE (GET_MODE (table))); | |
5352 | } | |
5353 | if (table_insn && GET_CODE (table_insn) == JUMP_INSN | |
5354 | && GET_CODE (PATTERN (table_insn)) == ADDR_DIFF_VEC) | |
5355 | { | |
5356 | rtx table = PATTERN (table_insn); | |
5357 | ||
5358 | if (offset >= 0 | |
5359 | && (offset / GET_MODE_SIZE (GET_MODE (table)) | |
5360 | < XVECLEN (table, 1))) | |
5361 | { | |
5362 | offset /= GET_MODE_SIZE (GET_MODE (table)); | |
38a448ca RH |
5363 | new = gen_rtx_MINUS (Pmode, XVECEXP (table, 1, offset), |
5364 | XEXP (table, 0)); | |
7afe21cc RK |
5365 | |
5366 | if (GET_MODE (table) != Pmode) | |
38a448ca | 5367 | new = gen_rtx_TRUNCATE (GET_MODE (table), new); |
7afe21cc | 5368 | |
67a37737 RK |
5369 | /* Indicate this is a constant. This isn't a |
5370 | valid form of CONST, but it will only be used | |
5371 | to fold the next insns and then discarded, so | |
ac7ef8d5 FS |
5372 | it should be safe. |
5373 | ||
5374 | Note this expression must be explicitly discarded, | |
5375 | by cse_insn, else it may end up in a REG_EQUAL note | |
5376 | and "escape" to cause problems elsewhere. */ | |
38a448ca | 5377 | return gen_rtx_CONST (GET_MODE (new), new); |
7afe21cc RK |
5378 | } |
5379 | } | |
5380 | } | |
5381 | ||
5382 | return x; | |
5383 | } | |
9255709c RK |
5384 | |
5385 | case ASM_OPERANDS: | |
5386 | for (i = XVECLEN (x, 3) - 1; i >= 0; i--) | |
5387 | validate_change (insn, &XVECEXP (x, 3, i), | |
5388 | fold_rtx (XVECEXP (x, 3, i), insn), 0); | |
5389 | break; | |
e9a25f70 JL |
5390 | |
5391 | default: | |
5392 | break; | |
7afe21cc RK |
5393 | } |
5394 | ||
5395 | const_arg0 = 0; | |
5396 | const_arg1 = 0; | |
5397 | const_arg2 = 0; | |
5398 | mode_arg0 = VOIDmode; | |
5399 | ||
5400 | /* Try folding our operands. | |
5401 | Then see which ones have constant values known. */ | |
5402 | ||
5403 | fmt = GET_RTX_FORMAT (code); | |
5404 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
5405 | if (fmt[i] == 'e') | |
5406 | { | |
5407 | rtx arg = XEXP (x, i); | |
5408 | rtx folded_arg = arg, const_arg = 0; | |
5409 | enum machine_mode mode_arg = GET_MODE (arg); | |
5410 | rtx cheap_arg, expensive_arg; | |
5411 | rtx replacements[2]; | |
5412 | int j; | |
5413 | ||
5414 | /* Most arguments are cheap, so handle them specially. */ | |
5415 | switch (GET_CODE (arg)) | |
5416 | { | |
5417 | case REG: | |
5418 | /* This is the same as calling equiv_constant; it is duplicated | |
5419 | here for speed. */ | |
5420 | if (REGNO_QTY_VALID_P (REGNO (arg)) | |
30f72379 MM |
5421 | && qty_const[REG_QTY (REGNO (arg))] != 0 |
5422 | && GET_CODE (qty_const[REG_QTY (REGNO (arg))]) != REG | |
5423 | && GET_CODE (qty_const[REG_QTY (REGNO (arg))]) != PLUS) | |
7afe21cc RK |
5424 | const_arg |
5425 | = gen_lowpart_if_possible (GET_MODE (arg), | |
30f72379 | 5426 | qty_const[REG_QTY (REGNO (arg))]); |
7afe21cc RK |
5427 | break; |
5428 | ||
5429 | case CONST: | |
5430 | case CONST_INT: | |
5431 | case SYMBOL_REF: | |
5432 | case LABEL_REF: | |
5433 | case CONST_DOUBLE: | |
5434 | const_arg = arg; | |
5435 | break; | |
5436 | ||
5437 | #ifdef HAVE_cc0 | |
5438 | case CC0: | |
5439 | folded_arg = prev_insn_cc0; | |
5440 | mode_arg = prev_insn_cc0_mode; | |
5441 | const_arg = equiv_constant (folded_arg); | |
5442 | break; | |
5443 | #endif | |
5444 | ||
5445 | default: | |
5446 | folded_arg = fold_rtx (arg, insn); | |
5447 | const_arg = equiv_constant (folded_arg); | |
5448 | } | |
5449 | ||
5450 | /* For the first three operands, see if the operand | |
5451 | is constant or equivalent to a constant. */ | |
5452 | switch (i) | |
5453 | { | |
5454 | case 0: | |
5455 | folded_arg0 = folded_arg; | |
5456 | const_arg0 = const_arg; | |
5457 | mode_arg0 = mode_arg; | |
5458 | break; | |
5459 | case 1: | |
5460 | folded_arg1 = folded_arg; | |
5461 | const_arg1 = const_arg; | |
5462 | break; | |
5463 | case 2: | |
5464 | const_arg2 = const_arg; | |
5465 | break; | |
5466 | } | |
5467 | ||
5468 | /* Pick the least expensive of the folded argument and an | |
5469 | equivalent constant argument. */ | |
5470 | if (const_arg == 0 || const_arg == folded_arg | |
5471 | || COST (const_arg) > COST (folded_arg)) | |
5472 | cheap_arg = folded_arg, expensive_arg = const_arg; | |
5473 | else | |
5474 | cheap_arg = const_arg, expensive_arg = folded_arg; | |
5475 | ||
5476 | /* Try to replace the operand with the cheapest of the two | |
5477 | possibilities. If it doesn't work and this is either of the first | |
5478 | two operands of a commutative operation, try swapping them. | |
5479 | If THAT fails, try the more expensive, provided it is cheaper | |
5480 | than what is already there. */ | |
5481 | ||
5482 | if (cheap_arg == XEXP (x, i)) | |
5483 | continue; | |
5484 | ||
5485 | if (insn == 0 && ! copied) | |
5486 | { | |
5487 | x = copy_rtx (x); | |
5488 | copied = 1; | |
5489 | } | |
5490 | ||
5491 | replacements[0] = cheap_arg, replacements[1] = expensive_arg; | |
5492 | for (j = 0; | |
5493 | j < 2 && replacements[j] | |
5494 | && COST (replacements[j]) < COST (XEXP (x, i)); | |
5495 | j++) | |
5496 | { | |
5497 | if (validate_change (insn, &XEXP (x, i), replacements[j], 0)) | |
5498 | break; | |
5499 | ||
5500 | if (code == NE || code == EQ || GET_RTX_CLASS (code) == 'c') | |
5501 | { | |
5502 | validate_change (insn, &XEXP (x, i), XEXP (x, 1 - i), 1); | |
5503 | validate_change (insn, &XEXP (x, 1 - i), replacements[j], 1); | |
5504 | ||
5505 | if (apply_change_group ()) | |
5506 | { | |
5507 | /* Swap them back to be invalid so that this loop can | |
5508 | continue and flag them to be swapped back later. */ | |
5509 | rtx tem; | |
5510 | ||
5511 | tem = XEXP (x, 0); XEXP (x, 0) = XEXP (x, 1); | |
5512 | XEXP (x, 1) = tem; | |
5513 | must_swap = 1; | |
5514 | break; | |
5515 | } | |
5516 | } | |
5517 | } | |
5518 | } | |
5519 | ||
2d8b0f3a JL |
5520 | else |
5521 | { | |
5522 | if (fmt[i] == 'E') | |
5523 | /* Don't try to fold inside of a vector of expressions. | |
5524 | Doing nothing is harmless. */ | |
5525 | {;} | |
5526 | } | |
7afe21cc RK |
5527 | |
5528 | /* If a commutative operation, place a constant integer as the second | |
5529 | operand unless the first operand is also a constant integer. Otherwise, | |
5530 | place any constant second unless the first operand is also a constant. */ | |
5531 | ||
5532 | if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c') | |
5533 | { | |
5534 | if (must_swap || (const_arg0 | |
5535 | && (const_arg1 == 0 | |
5536 | || (GET_CODE (const_arg0) == CONST_INT | |
5537 | && GET_CODE (const_arg1) != CONST_INT)))) | |
5538 | { | |
5539 | register rtx tem = XEXP (x, 0); | |
5540 | ||
5541 | if (insn == 0 && ! copied) | |
5542 | { | |
5543 | x = copy_rtx (x); | |
5544 | copied = 1; | |
5545 | } | |
5546 | ||
5547 | validate_change (insn, &XEXP (x, 0), XEXP (x, 1), 1); | |
5548 | validate_change (insn, &XEXP (x, 1), tem, 1); | |
5549 | if (apply_change_group ()) | |
5550 | { | |
5551 | tem = const_arg0, const_arg0 = const_arg1, const_arg1 = tem; | |
5552 | tem = folded_arg0, folded_arg0 = folded_arg1, folded_arg1 = tem; | |
5553 | } | |
5554 | } | |
5555 | } | |
5556 | ||
5557 | /* If X is an arithmetic operation, see if we can simplify it. */ | |
5558 | ||
5559 | switch (GET_RTX_CLASS (code)) | |
5560 | { | |
5561 | case '1': | |
67a37737 RK |
5562 | { |
5563 | int is_const = 0; | |
5564 | ||
5565 | /* We can't simplify extension ops unless we know the | |
5566 | original mode. */ | |
5567 | if ((code == ZERO_EXTEND || code == SIGN_EXTEND) | |
5568 | && mode_arg0 == VOIDmode) | |
5569 | break; | |
5570 | ||
5571 | /* If we had a CONST, strip it off and put it back later if we | |
5572 | fold. */ | |
5573 | if (const_arg0 != 0 && GET_CODE (const_arg0) == CONST) | |
5574 | is_const = 1, const_arg0 = XEXP (const_arg0, 0); | |
5575 | ||
5576 | new = simplify_unary_operation (code, mode, | |
5577 | const_arg0 ? const_arg0 : folded_arg0, | |
5578 | mode_arg0); | |
5579 | if (new != 0 && is_const) | |
38a448ca | 5580 | new = gen_rtx_CONST (mode, new); |
67a37737 | 5581 | } |
7afe21cc RK |
5582 | break; |
5583 | ||
5584 | case '<': | |
5585 | /* See what items are actually being compared and set FOLDED_ARG[01] | |
5586 | to those values and CODE to the actual comparison code. If any are | |
5587 | constant, set CONST_ARG0 and CONST_ARG1 appropriately. We needn't | |
5588 | do anything if both operands are already known to be constant. */ | |
5589 | ||
5590 | if (const_arg0 == 0 || const_arg1 == 0) | |
5591 | { | |
5592 | struct table_elt *p0, *p1; | |
c610adec | 5593 | rtx true = const_true_rtx, false = const0_rtx; |
13c9910f | 5594 | enum machine_mode mode_arg1; |
c610adec RK |
5595 | |
5596 | #ifdef FLOAT_STORE_FLAG_VALUE | |
c7c955ee | 5597 | if (GET_MODE_CLASS (mode) == MODE_FLOAT) |
c610adec | 5598 | { |
560c94a2 RK |
5599 | true = CONST_DOUBLE_FROM_REAL_VALUE (FLOAT_STORE_FLAG_VALUE, |
5600 | mode); | |
c610adec RK |
5601 | false = CONST0_RTX (mode); |
5602 | } | |
5603 | #endif | |
7afe21cc | 5604 | |
13c9910f RS |
5605 | code = find_comparison_args (code, &folded_arg0, &folded_arg1, |
5606 | &mode_arg0, &mode_arg1); | |
7afe21cc RK |
5607 | const_arg0 = equiv_constant (folded_arg0); |
5608 | const_arg1 = equiv_constant (folded_arg1); | |
5609 | ||
13c9910f RS |
5610 | /* If the mode is VOIDmode or a MODE_CC mode, we don't know |
5611 | what kinds of things are being compared, so we can't do | |
5612 | anything with this comparison. */ | |
7afe21cc RK |
5613 | |
5614 | if (mode_arg0 == VOIDmode || GET_MODE_CLASS (mode_arg0) == MODE_CC) | |
5615 | break; | |
5616 | ||
0f41302f MS |
5617 | /* If we do not now have two constants being compared, see |
5618 | if we can nevertheless deduce some things about the | |
5619 | comparison. */ | |
7afe21cc RK |
5620 | if (const_arg0 == 0 || const_arg1 == 0) |
5621 | { | |
0f41302f MS |
5622 | /* Is FOLDED_ARG0 frame-pointer plus a constant? Or |
5623 | non-explicit constant? These aren't zero, but we | |
5624 | don't know their sign. */ | |
7afe21cc RK |
5625 | if (const_arg1 == const0_rtx |
5626 | && (NONZERO_BASE_PLUS_P (folded_arg0) | |
5627 | #if 0 /* Sad to say, on sysvr4, #pragma weak can make a symbol address | |
5628 | come out as 0. */ | |
5629 | || GET_CODE (folded_arg0) == SYMBOL_REF | |
5630 | #endif | |
5631 | || GET_CODE (folded_arg0) == LABEL_REF | |
5632 | || GET_CODE (folded_arg0) == CONST)) | |
5633 | { | |
5634 | if (code == EQ) | |
c610adec | 5635 | return false; |
7afe21cc | 5636 | else if (code == NE) |
c610adec | 5637 | return true; |
7afe21cc RK |
5638 | } |
5639 | ||
5640 | /* See if the two operands are the same. We don't do this | |
5641 | for IEEE floating-point since we can't assume x == x | |
5642 | since x might be a NaN. */ | |
5643 | ||
5644 | if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
a83afb65 | 5645 | || ! FLOAT_MODE_P (mode_arg0) || flag_fast_math) |
7afe21cc RK |
5646 | && (folded_arg0 == folded_arg1 |
5647 | || (GET_CODE (folded_arg0) == REG | |
5648 | && GET_CODE (folded_arg1) == REG | |
30f72379 MM |
5649 | && (REG_QTY (REGNO (folded_arg0)) |
5650 | == REG_QTY (REGNO (folded_arg1)))) | |
7afe21cc RK |
5651 | || ((p0 = lookup (folded_arg0, |
5652 | (safe_hash (folded_arg0, mode_arg0) | |
5653 | % NBUCKETS), mode_arg0)) | |
5654 | && (p1 = lookup (folded_arg1, | |
5655 | (safe_hash (folded_arg1, mode_arg0) | |
5656 | % NBUCKETS), mode_arg0)) | |
5657 | && p0->first_same_value == p1->first_same_value))) | |
5658 | return ((code == EQ || code == LE || code == GE | |
5659 | || code == LEU || code == GEU) | |
c610adec | 5660 | ? true : false); |
7afe21cc RK |
5661 | |
5662 | /* If FOLDED_ARG0 is a register, see if the comparison we are | |
5663 | doing now is either the same as we did before or the reverse | |
5664 | (we only check the reverse if not floating-point). */ | |
5665 | else if (GET_CODE (folded_arg0) == REG) | |
5666 | { | |
30f72379 | 5667 | int qty = REG_QTY (REGNO (folded_arg0)); |
7afe21cc RK |
5668 | |
5669 | if (REGNO_QTY_VALID_P (REGNO (folded_arg0)) | |
5670 | && (comparison_dominates_p (qty_comparison_code[qty], code) | |
5671 | || (comparison_dominates_p (qty_comparison_code[qty], | |
5672 | reverse_condition (code)) | |
cbf6a543 | 5673 | && ! FLOAT_MODE_P (mode_arg0))) |
7afe21cc RK |
5674 | && (rtx_equal_p (qty_comparison_const[qty], folded_arg1) |
5675 | || (const_arg1 | |
5676 | && rtx_equal_p (qty_comparison_const[qty], | |
5677 | const_arg1)) | |
5678 | || (GET_CODE (folded_arg1) == REG | |
30f72379 | 5679 | && (REG_QTY (REGNO (folded_arg1)) |
7afe21cc RK |
5680 | == qty_comparison_qty[qty])))) |
5681 | return (comparison_dominates_p (qty_comparison_code[qty], | |
5682 | code) | |
c610adec | 5683 | ? true : false); |
7afe21cc RK |
5684 | } |
5685 | } | |
5686 | } | |
5687 | ||
5688 | /* If we are comparing against zero, see if the first operand is | |
5689 | equivalent to an IOR with a constant. If so, we may be able to | |
5690 | determine the result of this comparison. */ | |
5691 | ||
5692 | if (const_arg1 == const0_rtx) | |
5693 | { | |
5694 | rtx y = lookup_as_function (folded_arg0, IOR); | |
5695 | rtx inner_const; | |
5696 | ||
5697 | if (y != 0 | |
5698 | && (inner_const = equiv_constant (XEXP (y, 1))) != 0 | |
5699 | && GET_CODE (inner_const) == CONST_INT | |
5700 | && INTVAL (inner_const) != 0) | |
5701 | { | |
5702 | int sign_bitnum = GET_MODE_BITSIZE (mode_arg0) - 1; | |
906c4e36 RK |
5703 | int has_sign = (HOST_BITS_PER_WIDE_INT >= sign_bitnum |
5704 | && (INTVAL (inner_const) | |
5705 | & ((HOST_WIDE_INT) 1 << sign_bitnum))); | |
c610adec RK |
5706 | rtx true = const_true_rtx, false = const0_rtx; |
5707 | ||
5708 | #ifdef FLOAT_STORE_FLAG_VALUE | |
c7c955ee | 5709 | if (GET_MODE_CLASS (mode) == MODE_FLOAT) |
c610adec | 5710 | { |
560c94a2 RK |
5711 | true = CONST_DOUBLE_FROM_REAL_VALUE (FLOAT_STORE_FLAG_VALUE, |
5712 | mode); | |
c610adec RK |
5713 | false = CONST0_RTX (mode); |
5714 | } | |
5715 | #endif | |
7afe21cc RK |
5716 | |
5717 | switch (code) | |
5718 | { | |
5719 | case EQ: | |
c610adec | 5720 | return false; |
7afe21cc | 5721 | case NE: |
c610adec | 5722 | return true; |
7afe21cc RK |
5723 | case LT: case LE: |
5724 | if (has_sign) | |
c610adec | 5725 | return true; |
7afe21cc RK |
5726 | break; |
5727 | case GT: case GE: | |
5728 | if (has_sign) | |
c610adec | 5729 | return false; |
7afe21cc | 5730 | break; |
e9a25f70 JL |
5731 | default: |
5732 | break; | |
7afe21cc RK |
5733 | } |
5734 | } | |
5735 | } | |
5736 | ||
5737 | new = simplify_relational_operation (code, mode_arg0, | |
5738 | const_arg0 ? const_arg0 : folded_arg0, | |
5739 | const_arg1 ? const_arg1 : folded_arg1); | |
c610adec RK |
5740 | #ifdef FLOAT_STORE_FLAG_VALUE |
5741 | if (new != 0 && GET_MODE_CLASS (mode) == MODE_FLOAT) | |
5742 | new = ((new == const0_rtx) ? CONST0_RTX (mode) | |
560c94a2 | 5743 | : CONST_DOUBLE_FROM_REAL_VALUE (FLOAT_STORE_FLAG_VALUE, mode)); |
c610adec | 5744 | #endif |
7afe21cc RK |
5745 | break; |
5746 | ||
5747 | case '2': | |
5748 | case 'c': | |
5749 | switch (code) | |
5750 | { | |
5751 | case PLUS: | |
5752 | /* If the second operand is a LABEL_REF, see if the first is a MINUS | |
5753 | with that LABEL_REF as its second operand. If so, the result is | |
5754 | the first operand of that MINUS. This handles switches with an | |
5755 | ADDR_DIFF_VEC table. */ | |
5756 | if (const_arg1 && GET_CODE (const_arg1) == LABEL_REF) | |
5757 | { | |
e650cbda RK |
5758 | rtx y |
5759 | = GET_CODE (folded_arg0) == MINUS ? folded_arg0 | |
5760 | : lookup_as_function (folded_arg0, MINUS); | |
7afe21cc RK |
5761 | |
5762 | if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF | |
5763 | && XEXP (XEXP (y, 1), 0) == XEXP (const_arg1, 0)) | |
5764 | return XEXP (y, 0); | |
67a37737 RK |
5765 | |
5766 | /* Now try for a CONST of a MINUS like the above. */ | |
e650cbda RK |
5767 | if ((y = (GET_CODE (folded_arg0) == CONST ? folded_arg0 |
5768 | : lookup_as_function (folded_arg0, CONST))) != 0 | |
67a37737 RK |
5769 | && GET_CODE (XEXP (y, 0)) == MINUS |
5770 | && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF | |
5771 | && XEXP (XEXP (XEXP (y, 0),1), 0) == XEXP (const_arg1, 0)) | |
5772 | return XEXP (XEXP (y, 0), 0); | |
7afe21cc | 5773 | } |
c2cc0778 | 5774 | |
e650cbda RK |
5775 | /* Likewise if the operands are in the other order. */ |
5776 | if (const_arg0 && GET_CODE (const_arg0) == LABEL_REF) | |
5777 | { | |
5778 | rtx y | |
5779 | = GET_CODE (folded_arg1) == MINUS ? folded_arg1 | |
5780 | : lookup_as_function (folded_arg1, MINUS); | |
5781 | ||
5782 | if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF | |
5783 | && XEXP (XEXP (y, 1), 0) == XEXP (const_arg0, 0)) | |
5784 | return XEXP (y, 0); | |
5785 | ||
5786 | /* Now try for a CONST of a MINUS like the above. */ | |
5787 | if ((y = (GET_CODE (folded_arg1) == CONST ? folded_arg1 | |
5788 | : lookup_as_function (folded_arg1, CONST))) != 0 | |
5789 | && GET_CODE (XEXP (y, 0)) == MINUS | |
5790 | && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF | |
5791 | && XEXP (XEXP (XEXP (y, 0),1), 0) == XEXP (const_arg0, 0)) | |
5792 | return XEXP (XEXP (y, 0), 0); | |
5793 | } | |
5794 | ||
c2cc0778 RK |
5795 | /* If second operand is a register equivalent to a negative |
5796 | CONST_INT, see if we can find a register equivalent to the | |
5797 | positive constant. Make a MINUS if so. Don't do this for | |
5d595063 | 5798 | a non-negative constant since we might then alternate between |
c2cc0778 | 5799 | chosing positive and negative constants. Having the positive |
5d595063 RK |
5800 | constant previously-used is the more common case. Be sure |
5801 | the resulting constant is non-negative; if const_arg1 were | |
5802 | the smallest negative number this would overflow: depending | |
5803 | on the mode, this would either just be the same value (and | |
5804 | hence not save anything) or be incorrect. */ | |
5805 | if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT | |
5806 | && INTVAL (const_arg1) < 0 | |
5807 | && - INTVAL (const_arg1) >= 0 | |
5808 | && GET_CODE (folded_arg1) == REG) | |
c2cc0778 RK |
5809 | { |
5810 | rtx new_const = GEN_INT (- INTVAL (const_arg1)); | |
5811 | struct table_elt *p | |
5812 | = lookup (new_const, safe_hash (new_const, mode) % NBUCKETS, | |
5813 | mode); | |
5814 | ||
5815 | if (p) | |
5816 | for (p = p->first_same_value; p; p = p->next_same_value) | |
5817 | if (GET_CODE (p->exp) == REG) | |
5818 | return cse_gen_binary (MINUS, mode, folded_arg0, | |
5819 | canon_reg (p->exp, NULL_RTX)); | |
5820 | } | |
13c9910f RS |
5821 | goto from_plus; |
5822 | ||
5823 | case MINUS: | |
5824 | /* If we have (MINUS Y C), see if Y is known to be (PLUS Z C2). | |
5825 | If so, produce (PLUS Z C2-C). */ | |
5826 | if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT) | |
5827 | { | |
5828 | rtx y = lookup_as_function (XEXP (x, 0), PLUS); | |
5829 | if (y && GET_CODE (XEXP (y, 1)) == CONST_INT) | |
f3becefd RK |
5830 | return fold_rtx (plus_constant (copy_rtx (y), |
5831 | -INTVAL (const_arg1)), | |
a3b5c94a | 5832 | NULL_RTX); |
13c9910f | 5833 | } |
7afe21cc | 5834 | |
0f41302f | 5835 | /* ... fall through ... */ |
7afe21cc | 5836 | |
13c9910f | 5837 | from_plus: |
7afe21cc RK |
5838 | case SMIN: case SMAX: case UMIN: case UMAX: |
5839 | case IOR: case AND: case XOR: | |
5840 | case MULT: case DIV: case UDIV: | |
5841 | case ASHIFT: case LSHIFTRT: case ASHIFTRT: | |
5842 | /* If we have (<op> <reg> <const_int>) for an associative OP and REG | |
5843 | is known to be of similar form, we may be able to replace the | |
5844 | operation with a combined operation. This may eliminate the | |
5845 | intermediate operation if every use is simplified in this way. | |
5846 | Note that the similar optimization done by combine.c only works | |
5847 | if the intermediate operation's result has only one reference. */ | |
5848 | ||
5849 | if (GET_CODE (folded_arg0) == REG | |
5850 | && const_arg1 && GET_CODE (const_arg1) == CONST_INT) | |
5851 | { | |
5852 | int is_shift | |
5853 | = (code == ASHIFT || code == ASHIFTRT || code == LSHIFTRT); | |
5854 | rtx y = lookup_as_function (folded_arg0, code); | |
5855 | rtx inner_const; | |
5856 | enum rtx_code associate_code; | |
5857 | rtx new_const; | |
5858 | ||
5859 | if (y == 0 | |
5860 | || 0 == (inner_const | |
5861 | = equiv_constant (fold_rtx (XEXP (y, 1), 0))) | |
5862 | || GET_CODE (inner_const) != CONST_INT | |
5863 | /* If we have compiled a statement like | |
5864 | "if (x == (x & mask1))", and now are looking at | |
5865 | "x & mask2", we will have a case where the first operand | |
5866 | of Y is the same as our first operand. Unless we detect | |
5867 | this case, an infinite loop will result. */ | |
5868 | || XEXP (y, 0) == folded_arg0) | |
5869 | break; | |
5870 | ||
5871 | /* Don't associate these operations if they are a PLUS with the | |
5872 | same constant and it is a power of two. These might be doable | |
5873 | with a pre- or post-increment. Similarly for two subtracts of | |
5874 | identical powers of two with post decrement. */ | |
5875 | ||
5876 | if (code == PLUS && INTVAL (const_arg1) == INTVAL (inner_const) | |
940da324 JL |
5877 | && ((HAVE_PRE_INCREMENT |
5878 | && exact_log2 (INTVAL (const_arg1)) >= 0) | |
5879 | || (HAVE_POST_INCREMENT | |
5880 | && exact_log2 (INTVAL (const_arg1)) >= 0) | |
5881 | || (HAVE_PRE_DECREMENT | |
5882 | && exact_log2 (- INTVAL (const_arg1)) >= 0) | |
5883 | || (HAVE_POST_DECREMENT | |
5884 | && exact_log2 (- INTVAL (const_arg1)) >= 0))) | |
7afe21cc RK |
5885 | break; |
5886 | ||
5887 | /* Compute the code used to compose the constants. For example, | |
5888 | A/C1/C2 is A/(C1 * C2), so if CODE == DIV, we want MULT. */ | |
5889 | ||
5890 | associate_code | |
5891 | = (code == MULT || code == DIV || code == UDIV ? MULT | |
5892 | : is_shift || code == PLUS || code == MINUS ? PLUS : code); | |
5893 | ||
5894 | new_const = simplify_binary_operation (associate_code, mode, | |
5895 | const_arg1, inner_const); | |
5896 | ||
5897 | if (new_const == 0) | |
5898 | break; | |
5899 | ||
5900 | /* If we are associating shift operations, don't let this | |
4908e508 RS |
5901 | produce a shift of the size of the object or larger. |
5902 | This could occur when we follow a sign-extend by a right | |
5903 | shift on a machine that does a sign-extend as a pair | |
5904 | of shifts. */ | |
7afe21cc RK |
5905 | |
5906 | if (is_shift && GET_CODE (new_const) == CONST_INT | |
4908e508 RS |
5907 | && INTVAL (new_const) >= GET_MODE_BITSIZE (mode)) |
5908 | { | |
5909 | /* As an exception, we can turn an ASHIFTRT of this | |
5910 | form into a shift of the number of bits - 1. */ | |
5911 | if (code == ASHIFTRT) | |
5912 | new_const = GEN_INT (GET_MODE_BITSIZE (mode) - 1); | |
5913 | else | |
5914 | break; | |
5915 | } | |
7afe21cc RK |
5916 | |
5917 | y = copy_rtx (XEXP (y, 0)); | |
5918 | ||
5919 | /* If Y contains our first operand (the most common way this | |
5920 | can happen is if Y is a MEM), we would do into an infinite | |
5921 | loop if we tried to fold it. So don't in that case. */ | |
5922 | ||
5923 | if (! reg_mentioned_p (folded_arg0, y)) | |
5924 | y = fold_rtx (y, insn); | |
5925 | ||
96b0e481 | 5926 | return cse_gen_binary (code, mode, y, new_const); |
7afe21cc | 5927 | } |
e9a25f70 JL |
5928 | break; |
5929 | ||
5930 | default: | |
5931 | break; | |
7afe21cc RK |
5932 | } |
5933 | ||
5934 | new = simplify_binary_operation (code, mode, | |
5935 | const_arg0 ? const_arg0 : folded_arg0, | |
5936 | const_arg1 ? const_arg1 : folded_arg1); | |
5937 | break; | |
5938 | ||
5939 | case 'o': | |
5940 | /* (lo_sum (high X) X) is simply X. */ | |
5941 | if (code == LO_SUM && const_arg0 != 0 | |
5942 | && GET_CODE (const_arg0) == HIGH | |
5943 | && rtx_equal_p (XEXP (const_arg0, 0), const_arg1)) | |
5944 | return const_arg1; | |
5945 | break; | |
5946 | ||
5947 | case '3': | |
5948 | case 'b': | |
5949 | new = simplify_ternary_operation (code, mode, mode_arg0, | |
5950 | const_arg0 ? const_arg0 : folded_arg0, | |
5951 | const_arg1 ? const_arg1 : folded_arg1, | |
5952 | const_arg2 ? const_arg2 : XEXP (x, 2)); | |
5953 | break; | |
ee5332b8 RH |
5954 | |
5955 | case 'x': | |
5956 | /* Always eliminate CONSTANT_P_RTX at this stage. */ | |
5957 | if (code == CONSTANT_P_RTX) | |
5958 | return (const_arg0 ? const1_rtx : const0_rtx); | |
5959 | break; | |
7afe21cc RK |
5960 | } |
5961 | ||
5962 | return new ? new : x; | |
5963 | } | |
5964 | \f | |
5965 | /* Return a constant value currently equivalent to X. | |
5966 | Return 0 if we don't know one. */ | |
5967 | ||
5968 | static rtx | |
5969 | equiv_constant (x) | |
5970 | rtx x; | |
5971 | { | |
5972 | if (GET_CODE (x) == REG | |
5973 | && REGNO_QTY_VALID_P (REGNO (x)) | |
30f72379 MM |
5974 | && qty_const[REG_QTY (REGNO (x))]) |
5975 | x = gen_lowpart_if_possible (GET_MODE (x), qty_const[REG_QTY (REGNO (x))]); | |
7afe21cc | 5976 | |
2ce5e1b4 | 5977 | if (x == 0 || CONSTANT_P (x)) |
7afe21cc RK |
5978 | return x; |
5979 | ||
fc3ffe83 RK |
5980 | /* If X is a MEM, try to fold it outside the context of any insn to see if |
5981 | it might be equivalent to a constant. That handles the case where it | |
5982 | is a constant-pool reference. Then try to look it up in the hash table | |
5983 | in case it is something whose value we have seen before. */ | |
5984 | ||
5985 | if (GET_CODE (x) == MEM) | |
5986 | { | |
5987 | struct table_elt *elt; | |
5988 | ||
906c4e36 | 5989 | x = fold_rtx (x, NULL_RTX); |
fc3ffe83 RK |
5990 | if (CONSTANT_P (x)) |
5991 | return x; | |
5992 | ||
5993 | elt = lookup (x, safe_hash (x, GET_MODE (x)) % NBUCKETS, GET_MODE (x)); | |
5994 | if (elt == 0) | |
5995 | return 0; | |
5996 | ||
5997 | for (elt = elt->first_same_value; elt; elt = elt->next_same_value) | |
5998 | if (elt->is_const && CONSTANT_P (elt->exp)) | |
5999 | return elt->exp; | |
6000 | } | |
6001 | ||
7afe21cc RK |
6002 | return 0; |
6003 | } | |
6004 | \f | |
6005 | /* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point | |
6006 | number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the | |
6007 | least-significant part of X. | |
6008 | MODE specifies how big a part of X to return. | |
6009 | ||
6010 | If the requested operation cannot be done, 0 is returned. | |
6011 | ||
6012 | This is similar to gen_lowpart in emit-rtl.c. */ | |
6013 | ||
6014 | rtx | |
6015 | gen_lowpart_if_possible (mode, x) | |
6016 | enum machine_mode mode; | |
6017 | register rtx x; | |
6018 | { | |
6019 | rtx result = gen_lowpart_common (mode, x); | |
6020 | ||
6021 | if (result) | |
6022 | return result; | |
6023 | else if (GET_CODE (x) == MEM) | |
6024 | { | |
6025 | /* This is the only other case we handle. */ | |
6026 | register int offset = 0; | |
6027 | rtx new; | |
6028 | ||
f76b9db2 ILT |
6029 | if (WORDS_BIG_ENDIAN) |
6030 | offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD) | |
6031 | - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD)); | |
6032 | if (BYTES_BIG_ENDIAN) | |
6033 | /* Adjust the address so that the address-after-the-data is | |
6034 | unchanged. */ | |
6035 | offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)) | |
6036 | - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x)))); | |
38a448ca | 6037 | new = gen_rtx_MEM (mode, plus_constant (XEXP (x, 0), offset)); |
7afe21cc RK |
6038 | if (! memory_address_p (mode, XEXP (new, 0))) |
6039 | return 0; | |
7afe21cc | 6040 | RTX_UNCHANGING_P (new) = RTX_UNCHANGING_P (x); |
c6df88cb | 6041 | MEM_COPY_ATTRIBUTES (new, x); |
7afe21cc RK |
6042 | return new; |
6043 | } | |
6044 | else | |
6045 | return 0; | |
6046 | } | |
6047 | \f | |
6048 | /* Given INSN, a jump insn, TAKEN indicates if we are following the "taken" | |
6049 | branch. It will be zero if not. | |
6050 | ||
6051 | In certain cases, this can cause us to add an equivalence. For example, | |
6052 | if we are following the taken case of | |
6053 | if (i == 2) | |
6054 | we can add the fact that `i' and '2' are now equivalent. | |
6055 | ||
6056 | In any case, we can record that this comparison was passed. If the same | |
6057 | comparison is seen later, we will know its value. */ | |
6058 | ||
6059 | static void | |
6060 | record_jump_equiv (insn, taken) | |
6061 | rtx insn; | |
6062 | int taken; | |
6063 | { | |
6064 | int cond_known_true; | |
6065 | rtx op0, op1; | |
13c9910f | 6066 | enum machine_mode mode, mode0, mode1; |
7afe21cc RK |
6067 | int reversed_nonequality = 0; |
6068 | enum rtx_code code; | |
6069 | ||
6070 | /* Ensure this is the right kind of insn. */ | |
6071 | if (! condjump_p (insn) || simplejump_p (insn)) | |
6072 | return; | |
6073 | ||
6074 | /* See if this jump condition is known true or false. */ | |
6075 | if (taken) | |
6076 | cond_known_true = (XEXP (SET_SRC (PATTERN (insn)), 2) == pc_rtx); | |
6077 | else | |
6078 | cond_known_true = (XEXP (SET_SRC (PATTERN (insn)), 1) == pc_rtx); | |
6079 | ||
6080 | /* Get the type of comparison being done and the operands being compared. | |
6081 | If we had to reverse a non-equality condition, record that fact so we | |
6082 | know that it isn't valid for floating-point. */ | |
6083 | code = GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 0)); | |
6084 | op0 = fold_rtx (XEXP (XEXP (SET_SRC (PATTERN (insn)), 0), 0), insn); | |
6085 | op1 = fold_rtx (XEXP (XEXP (SET_SRC (PATTERN (insn)), 0), 1), insn); | |
6086 | ||
13c9910f | 6087 | code = find_comparison_args (code, &op0, &op1, &mode0, &mode1); |
7afe21cc RK |
6088 | if (! cond_known_true) |
6089 | { | |
6090 | reversed_nonequality = (code != EQ && code != NE); | |
6091 | code = reverse_condition (code); | |
6092 | } | |
6093 | ||
6094 | /* The mode is the mode of the non-constant. */ | |
13c9910f RS |
6095 | mode = mode0; |
6096 | if (mode1 != VOIDmode) | |
6097 | mode = mode1; | |
7afe21cc RK |
6098 | |
6099 | record_jump_cond (code, mode, op0, op1, reversed_nonequality); | |
6100 | } | |
6101 | ||
6102 | /* We know that comparison CODE applied to OP0 and OP1 in MODE is true. | |
6103 | REVERSED_NONEQUALITY is nonzero if CODE had to be swapped. | |
6104 | Make any useful entries we can with that information. Called from | |
6105 | above function and called recursively. */ | |
6106 | ||
6107 | static void | |
6108 | record_jump_cond (code, mode, op0, op1, reversed_nonequality) | |
6109 | enum rtx_code code; | |
6110 | enum machine_mode mode; | |
6111 | rtx op0, op1; | |
6112 | int reversed_nonequality; | |
6113 | { | |
2197a88a | 6114 | unsigned op0_hash, op1_hash; |
7afe21cc RK |
6115 | int op0_in_memory, op0_in_struct, op1_in_memory, op1_in_struct; |
6116 | struct table_elt *op0_elt, *op1_elt; | |
6117 | ||
6118 | /* If OP0 and OP1 are known equal, and either is a paradoxical SUBREG, | |
6119 | we know that they are also equal in the smaller mode (this is also | |
6120 | true for all smaller modes whether or not there is a SUBREG, but | |
ac7ef8d5 | 6121 | is not worth testing for with no SUBREG). */ |
7afe21cc | 6122 | |
2e794ee8 | 6123 | /* Note that GET_MODE (op0) may not equal MODE. */ |
7afe21cc | 6124 | if (code == EQ && GET_CODE (op0) == SUBREG |
2e794ee8 RS |
6125 | && (GET_MODE_SIZE (GET_MODE (op0)) |
6126 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) | |
7afe21cc RK |
6127 | { |
6128 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); | |
6129 | rtx tem = gen_lowpart_if_possible (inner_mode, op1); | |
6130 | ||
6131 | record_jump_cond (code, mode, SUBREG_REG (op0), | |
38a448ca | 6132 | tem ? tem : gen_rtx_SUBREG (inner_mode, op1, 0), |
7afe21cc RK |
6133 | reversed_nonequality); |
6134 | } | |
6135 | ||
6136 | if (code == EQ && GET_CODE (op1) == SUBREG | |
2e794ee8 RS |
6137 | && (GET_MODE_SIZE (GET_MODE (op1)) |
6138 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) | |
7afe21cc RK |
6139 | { |
6140 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); | |
6141 | rtx tem = gen_lowpart_if_possible (inner_mode, op0); | |
6142 | ||
6143 | record_jump_cond (code, mode, SUBREG_REG (op1), | |
38a448ca | 6144 | tem ? tem : gen_rtx_SUBREG (inner_mode, op0, 0), |
7afe21cc RK |
6145 | reversed_nonequality); |
6146 | } | |
6147 | ||
6148 | /* Similarly, if this is an NE comparison, and either is a SUBREG | |
6149 | making a smaller mode, we know the whole thing is also NE. */ | |
6150 | ||
2e794ee8 RS |
6151 | /* Note that GET_MODE (op0) may not equal MODE; |
6152 | if we test MODE instead, we can get an infinite recursion | |
6153 | alternating between two modes each wider than MODE. */ | |
6154 | ||
7afe21cc RK |
6155 | if (code == NE && GET_CODE (op0) == SUBREG |
6156 | && subreg_lowpart_p (op0) | |
2e794ee8 RS |
6157 | && (GET_MODE_SIZE (GET_MODE (op0)) |
6158 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) | |
7afe21cc RK |
6159 | { |
6160 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); | |
6161 | rtx tem = gen_lowpart_if_possible (inner_mode, op1); | |
6162 | ||
6163 | record_jump_cond (code, mode, SUBREG_REG (op0), | |
38a448ca | 6164 | tem ? tem : gen_rtx_SUBREG (inner_mode, op1, 0), |
7afe21cc RK |
6165 | reversed_nonequality); |
6166 | } | |
6167 | ||
6168 | if (code == NE && GET_CODE (op1) == SUBREG | |
6169 | && subreg_lowpart_p (op1) | |
2e794ee8 RS |
6170 | && (GET_MODE_SIZE (GET_MODE (op1)) |
6171 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) | |
7afe21cc RK |
6172 | { |
6173 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); | |
6174 | rtx tem = gen_lowpart_if_possible (inner_mode, op0); | |
6175 | ||
6176 | record_jump_cond (code, mode, SUBREG_REG (op1), | |
38a448ca | 6177 | tem ? tem : gen_rtx_SUBREG (inner_mode, op0, 0), |
7afe21cc RK |
6178 | reversed_nonequality); |
6179 | } | |
6180 | ||
6181 | /* Hash both operands. */ | |
6182 | ||
6183 | do_not_record = 0; | |
6184 | hash_arg_in_memory = 0; | |
6185 | hash_arg_in_struct = 0; | |
2197a88a | 6186 | op0_hash = HASH (op0, mode); |
7afe21cc RK |
6187 | op0_in_memory = hash_arg_in_memory; |
6188 | op0_in_struct = hash_arg_in_struct; | |
6189 | ||
6190 | if (do_not_record) | |
6191 | return; | |
6192 | ||
6193 | do_not_record = 0; | |
6194 | hash_arg_in_memory = 0; | |
6195 | hash_arg_in_struct = 0; | |
2197a88a | 6196 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
6197 | op1_in_memory = hash_arg_in_memory; |
6198 | op1_in_struct = hash_arg_in_struct; | |
6199 | ||
6200 | if (do_not_record) | |
6201 | return; | |
6202 | ||
6203 | /* Look up both operands. */ | |
2197a88a RK |
6204 | op0_elt = lookup (op0, op0_hash, mode); |
6205 | op1_elt = lookup (op1, op1_hash, mode); | |
7afe21cc | 6206 | |
af3869c1 RK |
6207 | /* If both operands are already equivalent or if they are not in the |
6208 | table but are identical, do nothing. */ | |
6209 | if ((op0_elt != 0 && op1_elt != 0 | |
6210 | && op0_elt->first_same_value == op1_elt->first_same_value) | |
6211 | || op0 == op1 || rtx_equal_p (op0, op1)) | |
6212 | return; | |
6213 | ||
7afe21cc | 6214 | /* If we aren't setting two things equal all we can do is save this |
b2796a4b RK |
6215 | comparison. Similarly if this is floating-point. In the latter |
6216 | case, OP1 might be zero and both -0.0 and 0.0 are equal to it. | |
6217 | If we record the equality, we might inadvertently delete code | |
6218 | whose intent was to change -0 to +0. */ | |
6219 | ||
cbf6a543 | 6220 | if (code != EQ || FLOAT_MODE_P (GET_MODE (op0))) |
7afe21cc RK |
6221 | { |
6222 | /* If we reversed a floating-point comparison, if OP0 is not a | |
6223 | register, or if OP1 is neither a register or constant, we can't | |
6224 | do anything. */ | |
6225 | ||
6226 | if (GET_CODE (op1) != REG) | |
6227 | op1 = equiv_constant (op1); | |
6228 | ||
cbf6a543 | 6229 | if ((reversed_nonequality && FLOAT_MODE_P (mode)) |
7afe21cc RK |
6230 | || GET_CODE (op0) != REG || op1 == 0) |
6231 | return; | |
6232 | ||
6233 | /* Put OP0 in the hash table if it isn't already. This gives it a | |
6234 | new quantity number. */ | |
6235 | if (op0_elt == 0) | |
6236 | { | |
906c4e36 | 6237 | if (insert_regs (op0, NULL_PTR, 0)) |
7afe21cc RK |
6238 | { |
6239 | rehash_using_reg (op0); | |
2197a88a | 6240 | op0_hash = HASH (op0, mode); |
2bb81c86 RK |
6241 | |
6242 | /* If OP0 is contained in OP1, this changes its hash code | |
6243 | as well. Faster to rehash than to check, except | |
6244 | for the simple case of a constant. */ | |
6245 | if (! CONSTANT_P (op1)) | |
2197a88a | 6246 | op1_hash = HASH (op1,mode); |
7afe21cc RK |
6247 | } |
6248 | ||
2197a88a | 6249 | op0_elt = insert (op0, NULL_PTR, op0_hash, mode); |
7afe21cc RK |
6250 | op0_elt->in_memory = op0_in_memory; |
6251 | op0_elt->in_struct = op0_in_struct; | |
6252 | } | |
6253 | ||
30f72379 | 6254 | qty_comparison_code[REG_QTY (REGNO (op0))] = code; |
7afe21cc RK |
6255 | if (GET_CODE (op1) == REG) |
6256 | { | |
5d5ea909 | 6257 | /* Look it up again--in case op0 and op1 are the same. */ |
2197a88a | 6258 | op1_elt = lookup (op1, op1_hash, mode); |
5d5ea909 | 6259 | |
7afe21cc RK |
6260 | /* Put OP1 in the hash table so it gets a new quantity number. */ |
6261 | if (op1_elt == 0) | |
6262 | { | |
906c4e36 | 6263 | if (insert_regs (op1, NULL_PTR, 0)) |
7afe21cc RK |
6264 | { |
6265 | rehash_using_reg (op1); | |
2197a88a | 6266 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
6267 | } |
6268 | ||
2197a88a | 6269 | op1_elt = insert (op1, NULL_PTR, op1_hash, mode); |
7afe21cc RK |
6270 | op1_elt->in_memory = op1_in_memory; |
6271 | op1_elt->in_struct = op1_in_struct; | |
6272 | } | |
6273 | ||
30f72379 MM |
6274 | qty_comparison_qty[REG_QTY (REGNO (op0))] = REG_QTY (REGNO (op1)); |
6275 | qty_comparison_const[REG_QTY (REGNO (op0))] = 0; | |
7afe21cc RK |
6276 | } |
6277 | else | |
6278 | { | |
30f72379 MM |
6279 | qty_comparison_qty[REG_QTY (REGNO (op0))] = -1; |
6280 | qty_comparison_const[REG_QTY (REGNO (op0))] = op1; | |
7afe21cc RK |
6281 | } |
6282 | ||
6283 | return; | |
6284 | } | |
6285 | ||
eb5ad42a RS |
6286 | /* If either side is still missing an equivalence, make it now, |
6287 | then merge the equivalences. */ | |
7afe21cc | 6288 | |
7afe21cc RK |
6289 | if (op0_elt == 0) |
6290 | { | |
eb5ad42a | 6291 | if (insert_regs (op0, NULL_PTR, 0)) |
7afe21cc RK |
6292 | { |
6293 | rehash_using_reg (op0); | |
2197a88a | 6294 | op0_hash = HASH (op0, mode); |
7afe21cc RK |
6295 | } |
6296 | ||
2197a88a | 6297 | op0_elt = insert (op0, NULL_PTR, op0_hash, mode); |
7afe21cc RK |
6298 | op0_elt->in_memory = op0_in_memory; |
6299 | op0_elt->in_struct = op0_in_struct; | |
7afe21cc RK |
6300 | } |
6301 | ||
6302 | if (op1_elt == 0) | |
6303 | { | |
eb5ad42a | 6304 | if (insert_regs (op1, NULL_PTR, 0)) |
7afe21cc RK |
6305 | { |
6306 | rehash_using_reg (op1); | |
2197a88a | 6307 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
6308 | } |
6309 | ||
2197a88a | 6310 | op1_elt = insert (op1, NULL_PTR, op1_hash, mode); |
7afe21cc RK |
6311 | op1_elt->in_memory = op1_in_memory; |
6312 | op1_elt->in_struct = op1_in_struct; | |
7afe21cc | 6313 | } |
eb5ad42a RS |
6314 | |
6315 | merge_equiv_classes (op0_elt, op1_elt); | |
6316 | last_jump_equiv_class = op0_elt; | |
7afe21cc RK |
6317 | } |
6318 | \f | |
6319 | /* CSE processing for one instruction. | |
6320 | First simplify sources and addresses of all assignments | |
6321 | in the instruction, using previously-computed equivalents values. | |
6322 | Then install the new sources and destinations in the table | |
6323 | of available values. | |
6324 | ||
1ed0205e VM |
6325 | If LIBCALL_INSN is nonzero, don't record any equivalence made in |
6326 | the insn. It means that INSN is inside libcall block. In this | |
6327 | case LIBCALL_INSN is the corresponding insn with REG_LIBCALL. */ | |
7afe21cc RK |
6328 | |
6329 | /* Data on one SET contained in the instruction. */ | |
6330 | ||
6331 | struct set | |
6332 | { | |
6333 | /* The SET rtx itself. */ | |
6334 | rtx rtl; | |
6335 | /* The SET_SRC of the rtx (the original value, if it is changing). */ | |
6336 | rtx src; | |
6337 | /* The hash-table element for the SET_SRC of the SET. */ | |
6338 | struct table_elt *src_elt; | |
2197a88a RK |
6339 | /* Hash value for the SET_SRC. */ |
6340 | unsigned src_hash; | |
6341 | /* Hash value for the SET_DEST. */ | |
6342 | unsigned dest_hash; | |
7afe21cc RK |
6343 | /* The SET_DEST, with SUBREG, etc., stripped. */ |
6344 | rtx inner_dest; | |
6345 | /* Place where the pointer to the INNER_DEST was found. */ | |
6346 | rtx *inner_dest_loc; | |
6347 | /* Nonzero if the SET_SRC is in memory. */ | |
6348 | char src_in_memory; | |
6349 | /* Nonzero if the SET_SRC is in a structure. */ | |
6350 | char src_in_struct; | |
6351 | /* Nonzero if the SET_SRC contains something | |
6352 | whose value cannot be predicted and understood. */ | |
6353 | char src_volatile; | |
6354 | /* Original machine mode, in case it becomes a CONST_INT. */ | |
6355 | enum machine_mode mode; | |
6356 | /* A constant equivalent for SET_SRC, if any. */ | |
6357 | rtx src_const; | |
2197a88a RK |
6358 | /* Hash value of constant equivalent for SET_SRC. */ |
6359 | unsigned src_const_hash; | |
7afe21cc RK |
6360 | /* Table entry for constant equivalent for SET_SRC, if any. */ |
6361 | struct table_elt *src_const_elt; | |
6362 | }; | |
6363 | ||
6364 | static void | |
7bd8b2a8 | 6365 | cse_insn (insn, libcall_insn) |
7afe21cc | 6366 | rtx insn; |
7bd8b2a8 | 6367 | rtx libcall_insn; |
7afe21cc RK |
6368 | { |
6369 | register rtx x = PATTERN (insn); | |
7afe21cc | 6370 | register int i; |
92f9aa51 | 6371 | rtx tem; |
7afe21cc RK |
6372 | register int n_sets = 0; |
6373 | ||
2d8b0f3a | 6374 | #ifdef HAVE_cc0 |
7afe21cc RK |
6375 | /* Records what this insn does to set CC0. */ |
6376 | rtx this_insn_cc0 = 0; | |
135d84b8 | 6377 | enum machine_mode this_insn_cc0_mode = VOIDmode; |
2d8b0f3a | 6378 | #endif |
7afe21cc RK |
6379 | |
6380 | rtx src_eqv = 0; | |
6381 | struct table_elt *src_eqv_elt = 0; | |
6382 | int src_eqv_volatile; | |
6383 | int src_eqv_in_memory; | |
6384 | int src_eqv_in_struct; | |
2197a88a | 6385 | unsigned src_eqv_hash; |
7afe21cc RK |
6386 | |
6387 | struct set *sets; | |
6388 | ||
6389 | this_insn = insn; | |
7afe21cc RK |
6390 | |
6391 | /* Find all the SETs and CLOBBERs in this instruction. | |
6392 | Record all the SETs in the array `set' and count them. | |
6393 | Also determine whether there is a CLOBBER that invalidates | |
6394 | all memory references, or all references at varying addresses. */ | |
6395 | ||
f1e7c95f RK |
6396 | if (GET_CODE (insn) == CALL_INSN) |
6397 | { | |
6398 | for (tem = CALL_INSN_FUNCTION_USAGE (insn); tem; tem = XEXP (tem, 1)) | |
6399 | if (GET_CODE (XEXP (tem, 0)) == CLOBBER) | |
bb4034b3 | 6400 | invalidate (SET_DEST (XEXP (tem, 0)), VOIDmode); |
f1e7c95f RK |
6401 | } |
6402 | ||
7afe21cc RK |
6403 | if (GET_CODE (x) == SET) |
6404 | { | |
6405 | sets = (struct set *) alloca (sizeof (struct set)); | |
6406 | sets[0].rtl = x; | |
6407 | ||
6408 | /* Ignore SETs that are unconditional jumps. | |
6409 | They never need cse processing, so this does not hurt. | |
6410 | The reason is not efficiency but rather | |
6411 | so that we can test at the end for instructions | |
6412 | that have been simplified to unconditional jumps | |
6413 | and not be misled by unchanged instructions | |
6414 | that were unconditional jumps to begin with. */ | |
6415 | if (SET_DEST (x) == pc_rtx | |
6416 | && GET_CODE (SET_SRC (x)) == LABEL_REF) | |
6417 | ; | |
6418 | ||
6419 | /* Don't count call-insns, (set (reg 0) (call ...)), as a set. | |
6420 | The hard function value register is used only once, to copy to | |
6421 | someplace else, so it isn't worth cse'ing (and on 80386 is unsafe)! | |
6422 | Ensure we invalidate the destination register. On the 80386 no | |
7722328e | 6423 | other code would invalidate it since it is a fixed_reg. |
0f41302f | 6424 | We need not check the return of apply_change_group; see canon_reg. */ |
7afe21cc RK |
6425 | |
6426 | else if (GET_CODE (SET_SRC (x)) == CALL) | |
6427 | { | |
6428 | canon_reg (SET_SRC (x), insn); | |
77fa0940 | 6429 | apply_change_group (); |
7afe21cc | 6430 | fold_rtx (SET_SRC (x), insn); |
bb4034b3 | 6431 | invalidate (SET_DEST (x), VOIDmode); |
7afe21cc RK |
6432 | } |
6433 | else | |
6434 | n_sets = 1; | |
6435 | } | |
6436 | else if (GET_CODE (x) == PARALLEL) | |
6437 | { | |
6438 | register int lim = XVECLEN (x, 0); | |
6439 | ||
6440 | sets = (struct set *) alloca (lim * sizeof (struct set)); | |
6441 | ||
6442 | /* Find all regs explicitly clobbered in this insn, | |
6443 | and ensure they are not replaced with any other regs | |
6444 | elsewhere in this insn. | |
6445 | When a reg that is clobbered is also used for input, | |
6446 | we should presume that that is for a reason, | |
6447 | and we should not substitute some other register | |
6448 | which is not supposed to be clobbered. | |
6449 | Therefore, this loop cannot be merged into the one below | |
830a38ee | 6450 | because a CALL may precede a CLOBBER and refer to the |
7afe21cc RK |
6451 | value clobbered. We must not let a canonicalization do |
6452 | anything in that case. */ | |
6453 | for (i = 0; i < lim; i++) | |
6454 | { | |
6455 | register rtx y = XVECEXP (x, 0, i); | |
2708da92 RS |
6456 | if (GET_CODE (y) == CLOBBER) |
6457 | { | |
6458 | rtx clobbered = XEXP (y, 0); | |
6459 | ||
6460 | if (GET_CODE (clobbered) == REG | |
6461 | || GET_CODE (clobbered) == SUBREG) | |
bb4034b3 | 6462 | invalidate (clobbered, VOIDmode); |
2708da92 RS |
6463 | else if (GET_CODE (clobbered) == STRICT_LOW_PART |
6464 | || GET_CODE (clobbered) == ZERO_EXTRACT) | |
bb4034b3 | 6465 | invalidate (XEXP (clobbered, 0), GET_MODE (clobbered)); |
2708da92 | 6466 | } |
7afe21cc RK |
6467 | } |
6468 | ||
6469 | for (i = 0; i < lim; i++) | |
6470 | { | |
6471 | register rtx y = XVECEXP (x, 0, i); | |
6472 | if (GET_CODE (y) == SET) | |
6473 | { | |
7722328e RK |
6474 | /* As above, we ignore unconditional jumps and call-insns and |
6475 | ignore the result of apply_change_group. */ | |
7afe21cc RK |
6476 | if (GET_CODE (SET_SRC (y)) == CALL) |
6477 | { | |
6478 | canon_reg (SET_SRC (y), insn); | |
77fa0940 | 6479 | apply_change_group (); |
7afe21cc | 6480 | fold_rtx (SET_SRC (y), insn); |
bb4034b3 | 6481 | invalidate (SET_DEST (y), VOIDmode); |
7afe21cc RK |
6482 | } |
6483 | else if (SET_DEST (y) == pc_rtx | |
6484 | && GET_CODE (SET_SRC (y)) == LABEL_REF) | |
6485 | ; | |
6486 | else | |
6487 | sets[n_sets++].rtl = y; | |
6488 | } | |
6489 | else if (GET_CODE (y) == CLOBBER) | |
6490 | { | |
9ae8ffe7 | 6491 | /* If we clobber memory, canon the address. |
7afe21cc RK |
6492 | This does nothing when a register is clobbered |
6493 | because we have already invalidated the reg. */ | |
6494 | if (GET_CODE (XEXP (y, 0)) == MEM) | |
9ae8ffe7 | 6495 | canon_reg (XEXP (y, 0), NULL_RTX); |
7afe21cc RK |
6496 | } |
6497 | else if (GET_CODE (y) == USE | |
6498 | && ! (GET_CODE (XEXP (y, 0)) == REG | |
6499 | && REGNO (XEXP (y, 0)) < FIRST_PSEUDO_REGISTER)) | |
906c4e36 | 6500 | canon_reg (y, NULL_RTX); |
7afe21cc RK |
6501 | else if (GET_CODE (y) == CALL) |
6502 | { | |
7722328e RK |
6503 | /* The result of apply_change_group can be ignored; see |
6504 | canon_reg. */ | |
7afe21cc | 6505 | canon_reg (y, insn); |
77fa0940 | 6506 | apply_change_group (); |
7afe21cc RK |
6507 | fold_rtx (y, insn); |
6508 | } | |
6509 | } | |
6510 | } | |
6511 | else if (GET_CODE (x) == CLOBBER) | |
6512 | { | |
6513 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
9ae8ffe7 | 6514 | canon_reg (XEXP (x, 0), NULL_RTX); |
7afe21cc RK |
6515 | } |
6516 | ||
6517 | /* Canonicalize a USE of a pseudo register or memory location. */ | |
6518 | else if (GET_CODE (x) == USE | |
6519 | && ! (GET_CODE (XEXP (x, 0)) == REG | |
6520 | && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)) | |
906c4e36 | 6521 | canon_reg (XEXP (x, 0), NULL_RTX); |
7afe21cc RK |
6522 | else if (GET_CODE (x) == CALL) |
6523 | { | |
7722328e | 6524 | /* The result of apply_change_group can be ignored; see canon_reg. */ |
7afe21cc | 6525 | canon_reg (x, insn); |
77fa0940 | 6526 | apply_change_group (); |
7afe21cc RK |
6527 | fold_rtx (x, insn); |
6528 | } | |
6529 | ||
7b3ab05e JW |
6530 | /* Store the equivalent value in SRC_EQV, if different, or if the DEST |
6531 | is a STRICT_LOW_PART. The latter condition is necessary because SRC_EQV | |
6532 | is handled specially for this case, and if it isn't set, then there will | |
9faa82d8 | 6533 | be no equivalence for the destination. */ |
92f9aa51 RK |
6534 | if (n_sets == 1 && REG_NOTES (insn) != 0 |
6535 | && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0 | |
7b3ab05e JW |
6536 | && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl)) |
6537 | || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART)) | |
92f9aa51 | 6538 | src_eqv = canon_reg (XEXP (tem, 0), NULL_RTX); |
7afe21cc RK |
6539 | |
6540 | /* Canonicalize sources and addresses of destinations. | |
6541 | We do this in a separate pass to avoid problems when a MATCH_DUP is | |
6542 | present in the insn pattern. In that case, we want to ensure that | |
6543 | we don't break the duplicate nature of the pattern. So we will replace | |
6544 | both operands at the same time. Otherwise, we would fail to find an | |
6545 | equivalent substitution in the loop calling validate_change below. | |
7afe21cc RK |
6546 | |
6547 | We used to suppress canonicalization of DEST if it appears in SRC, | |
77fa0940 | 6548 | but we don't do this any more. */ |
7afe21cc RK |
6549 | |
6550 | for (i = 0; i < n_sets; i++) | |
6551 | { | |
6552 | rtx dest = SET_DEST (sets[i].rtl); | |
6553 | rtx src = SET_SRC (sets[i].rtl); | |
6554 | rtx new = canon_reg (src, insn); | |
58873255 | 6555 | int insn_code; |
7afe21cc | 6556 | |
77fa0940 RK |
6557 | if ((GET_CODE (new) == REG && GET_CODE (src) == REG |
6558 | && ((REGNO (new) < FIRST_PSEUDO_REGISTER) | |
6559 | != (REGNO (src) < FIRST_PSEUDO_REGISTER))) | |
58873255 RK |
6560 | || (insn_code = recog_memoized (insn)) < 0 |
6561 | || insn_n_dups[insn_code] > 0) | |
77fa0940 | 6562 | validate_change (insn, &SET_SRC (sets[i].rtl), new, 1); |
7afe21cc RK |
6563 | else |
6564 | SET_SRC (sets[i].rtl) = new; | |
6565 | ||
6566 | if (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
6567 | { | |
6568 | validate_change (insn, &XEXP (dest, 1), | |
77fa0940 | 6569 | canon_reg (XEXP (dest, 1), insn), 1); |
7afe21cc | 6570 | validate_change (insn, &XEXP (dest, 2), |
77fa0940 | 6571 | canon_reg (XEXP (dest, 2), insn), 1); |
7afe21cc RK |
6572 | } |
6573 | ||
6574 | while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART | |
6575 | || GET_CODE (dest) == ZERO_EXTRACT | |
6576 | || GET_CODE (dest) == SIGN_EXTRACT) | |
6577 | dest = XEXP (dest, 0); | |
6578 | ||
6579 | if (GET_CODE (dest) == MEM) | |
6580 | canon_reg (dest, insn); | |
6581 | } | |
6582 | ||
77fa0940 RK |
6583 | /* Now that we have done all the replacements, we can apply the change |
6584 | group and see if they all work. Note that this will cause some | |
6585 | canonicalizations that would have worked individually not to be applied | |
6586 | because some other canonicalization didn't work, but this should not | |
7722328e RK |
6587 | occur often. |
6588 | ||
6589 | The result of apply_change_group can be ignored; see canon_reg. */ | |
77fa0940 RK |
6590 | |
6591 | apply_change_group (); | |
6592 | ||
7afe21cc RK |
6593 | /* Set sets[i].src_elt to the class each source belongs to. |
6594 | Detect assignments from or to volatile things | |
6595 | and set set[i] to zero so they will be ignored | |
6596 | in the rest of this function. | |
6597 | ||
6598 | Nothing in this loop changes the hash table or the register chains. */ | |
6599 | ||
6600 | for (i = 0; i < n_sets; i++) | |
6601 | { | |
6602 | register rtx src, dest; | |
6603 | register rtx src_folded; | |
6604 | register struct table_elt *elt = 0, *p; | |
6605 | enum machine_mode mode; | |
6606 | rtx src_eqv_here; | |
6607 | rtx src_const = 0; | |
6608 | rtx src_related = 0; | |
6609 | struct table_elt *src_const_elt = 0; | |
6610 | int src_cost = 10000, src_eqv_cost = 10000, src_folded_cost = 10000; | |
6611 | int src_related_cost = 10000, src_elt_cost = 10000; | |
6612 | /* Set non-zero if we need to call force_const_mem on with the | |
6613 | contents of src_folded before using it. */ | |
6614 | int src_folded_force_flag = 0; | |
6615 | ||
6616 | dest = SET_DEST (sets[i].rtl); | |
6617 | src = SET_SRC (sets[i].rtl); | |
6618 | ||
6619 | /* If SRC is a constant that has no machine mode, | |
6620 | hash it with the destination's machine mode. | |
6621 | This way we can keep different modes separate. */ | |
6622 | ||
6623 | mode = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src); | |
6624 | sets[i].mode = mode; | |
6625 | ||
6626 | if (src_eqv) | |
6627 | { | |
6628 | enum machine_mode eqvmode = mode; | |
6629 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
6630 | eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0))); | |
6631 | do_not_record = 0; | |
6632 | hash_arg_in_memory = 0; | |
6633 | hash_arg_in_struct = 0; | |
6634 | src_eqv = fold_rtx (src_eqv, insn); | |
2197a88a | 6635 | src_eqv_hash = HASH (src_eqv, eqvmode); |
7afe21cc RK |
6636 | |
6637 | /* Find the equivalence class for the equivalent expression. */ | |
6638 | ||
6639 | if (!do_not_record) | |
2197a88a | 6640 | src_eqv_elt = lookup (src_eqv, src_eqv_hash, eqvmode); |
7afe21cc RK |
6641 | |
6642 | src_eqv_volatile = do_not_record; | |
6643 | src_eqv_in_memory = hash_arg_in_memory; | |
6644 | src_eqv_in_struct = hash_arg_in_struct; | |
6645 | } | |
6646 | ||
6647 | /* If this is a STRICT_LOW_PART assignment, src_eqv corresponds to the | |
6648 | value of the INNER register, not the destination. So it is not | |
3826a3da | 6649 | a valid substitution for the source. But save it for later. */ |
7afe21cc RK |
6650 | if (GET_CODE (dest) == STRICT_LOW_PART) |
6651 | src_eqv_here = 0; | |
6652 | else | |
6653 | src_eqv_here = src_eqv; | |
6654 | ||
6655 | /* Simplify and foldable subexpressions in SRC. Then get the fully- | |
6656 | simplified result, which may not necessarily be valid. */ | |
6657 | src_folded = fold_rtx (src, insn); | |
6658 | ||
e6a125a0 RK |
6659 | #if 0 |
6660 | /* ??? This caused bad code to be generated for the m68k port with -O2. | |
6661 | Suppose src is (CONST_INT -1), and that after truncation src_folded | |
6662 | is (CONST_INT 3). Suppose src_folded is then used for src_const. | |
6663 | At the end we will add src and src_const to the same equivalence | |
6664 | class. We now have 3 and -1 on the same equivalence class. This | |
6665 | causes later instructions to be mis-optimized. */ | |
7afe21cc RK |
6666 | /* If storing a constant in a bitfield, pre-truncate the constant |
6667 | so we will be able to record it later. */ | |
6668 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT | |
6669 | || GET_CODE (SET_DEST (sets[i].rtl)) == SIGN_EXTRACT) | |
6670 | { | |
6671 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
6672 | ||
6673 | if (GET_CODE (src) == CONST_INT | |
6674 | && GET_CODE (width) == CONST_INT | |
906c4e36 RK |
6675 | && INTVAL (width) < HOST_BITS_PER_WIDE_INT |
6676 | && (INTVAL (src) & ((HOST_WIDE_INT) (-1) << INTVAL (width)))) | |
6677 | src_folded | |
6678 | = GEN_INT (INTVAL (src) & (((HOST_WIDE_INT) 1 | |
6679 | << INTVAL (width)) - 1)); | |
7afe21cc | 6680 | } |
e6a125a0 | 6681 | #endif |
7afe21cc RK |
6682 | |
6683 | /* Compute SRC's hash code, and also notice if it | |
6684 | should not be recorded at all. In that case, | |
6685 | prevent any further processing of this assignment. */ | |
6686 | do_not_record = 0; | |
6687 | hash_arg_in_memory = 0; | |
6688 | hash_arg_in_struct = 0; | |
6689 | ||
6690 | sets[i].src = src; | |
2197a88a | 6691 | sets[i].src_hash = HASH (src, mode); |
7afe21cc RK |
6692 | sets[i].src_volatile = do_not_record; |
6693 | sets[i].src_in_memory = hash_arg_in_memory; | |
6694 | sets[i].src_in_struct = hash_arg_in_struct; | |
6695 | ||
50196afa RK |
6696 | /* If SRC is a MEM, there is a REG_EQUIV note for SRC, and DEST is |
6697 | a pseudo that is set more than once, do not record SRC. Using | |
6698 | SRC as a replacement for anything else will be incorrect in that | |
6699 | situation. Note that this usually occurs only for stack slots, | |
956d6950 | 6700 | in which case all the RTL would be referring to SRC, so we don't |
50196afa RK |
6701 | lose any optimization opportunities by not having SRC in the |
6702 | hash table. */ | |
6703 | ||
6704 | if (GET_CODE (src) == MEM | |
6705 | && find_reg_note (insn, REG_EQUIV, src) != 0 | |
6706 | && GET_CODE (dest) == REG | |
6707 | && REGNO (dest) >= FIRST_PSEUDO_REGISTER | |
b1f21e0a | 6708 | && REG_N_SETS (REGNO (dest)) != 1) |
50196afa RK |
6709 | sets[i].src_volatile = 1; |
6710 | ||
0dadecf6 RK |
6711 | #if 0 |
6712 | /* It is no longer clear why we used to do this, but it doesn't | |
6713 | appear to still be needed. So let's try without it since this | |
6714 | code hurts cse'ing widened ops. */ | |
7afe21cc RK |
6715 | /* If source is a perverse subreg (such as QI treated as an SI), |
6716 | treat it as volatile. It may do the work of an SI in one context | |
6717 | where the extra bits are not being used, but cannot replace an SI | |
6718 | in general. */ | |
6719 | if (GET_CODE (src) == SUBREG | |
6720 | && (GET_MODE_SIZE (GET_MODE (src)) | |
6721 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))))) | |
6722 | sets[i].src_volatile = 1; | |
0dadecf6 | 6723 | #endif |
7afe21cc RK |
6724 | |
6725 | /* Locate all possible equivalent forms for SRC. Try to replace | |
6726 | SRC in the insn with each cheaper equivalent. | |
6727 | ||
6728 | We have the following types of equivalents: SRC itself, a folded | |
6729 | version, a value given in a REG_EQUAL note, or a value related | |
6730 | to a constant. | |
6731 | ||
6732 | Each of these equivalents may be part of an additional class | |
6733 | of equivalents (if more than one is in the table, they must be in | |
6734 | the same class; we check for this). | |
6735 | ||
6736 | If the source is volatile, we don't do any table lookups. | |
6737 | ||
6738 | We note any constant equivalent for possible later use in a | |
6739 | REG_NOTE. */ | |
6740 | ||
6741 | if (!sets[i].src_volatile) | |
2197a88a | 6742 | elt = lookup (src, sets[i].src_hash, mode); |
7afe21cc RK |
6743 | |
6744 | sets[i].src_elt = elt; | |
6745 | ||
6746 | if (elt && src_eqv_here && src_eqv_elt) | |
6747 | { | |
6748 | if (elt->first_same_value != src_eqv_elt->first_same_value) | |
6749 | { | |
6750 | /* The REG_EQUAL is indicating that two formerly distinct | |
6751 | classes are now equivalent. So merge them. */ | |
6752 | merge_equiv_classes (elt, src_eqv_elt); | |
2197a88a RK |
6753 | src_eqv_hash = HASH (src_eqv, elt->mode); |
6754 | src_eqv_elt = lookup (src_eqv, src_eqv_hash, elt->mode); | |
7afe21cc RK |
6755 | } |
6756 | ||
6757 | src_eqv_here = 0; | |
6758 | } | |
6759 | ||
6760 | else if (src_eqv_elt) | |
6761 | elt = src_eqv_elt; | |
6762 | ||
6763 | /* Try to find a constant somewhere and record it in `src_const'. | |
6764 | Record its table element, if any, in `src_const_elt'. Look in | |
6765 | any known equivalences first. (If the constant is not in the | |
2197a88a | 6766 | table, also set `sets[i].src_const_hash'). */ |
7afe21cc RK |
6767 | if (elt) |
6768 | for (p = elt->first_same_value; p; p = p->next_same_value) | |
6769 | if (p->is_const) | |
6770 | { | |
6771 | src_const = p->exp; | |
6772 | src_const_elt = elt; | |
6773 | break; | |
6774 | } | |
6775 | ||
6776 | if (src_const == 0 | |
6777 | && (CONSTANT_P (src_folded) | |
6778 | /* Consider (minus (label_ref L1) (label_ref L2)) as | |
6779 | "constant" here so we will record it. This allows us | |
6780 | to fold switch statements when an ADDR_DIFF_VEC is used. */ | |
6781 | || (GET_CODE (src_folded) == MINUS | |
6782 | && GET_CODE (XEXP (src_folded, 0)) == LABEL_REF | |
6783 | && GET_CODE (XEXP (src_folded, 1)) == LABEL_REF))) | |
6784 | src_const = src_folded, src_const_elt = elt; | |
6785 | else if (src_const == 0 && src_eqv_here && CONSTANT_P (src_eqv_here)) | |
6786 | src_const = src_eqv_here, src_const_elt = src_eqv_elt; | |
6787 | ||
6788 | /* If we don't know if the constant is in the table, get its | |
6789 | hash code and look it up. */ | |
6790 | if (src_const && src_const_elt == 0) | |
6791 | { | |
2197a88a RK |
6792 | sets[i].src_const_hash = HASH (src_const, mode); |
6793 | src_const_elt = lookup (src_const, sets[i].src_const_hash, mode); | |
7afe21cc RK |
6794 | } |
6795 | ||
6796 | sets[i].src_const = src_const; | |
6797 | sets[i].src_const_elt = src_const_elt; | |
6798 | ||
6799 | /* If the constant and our source are both in the table, mark them as | |
6800 | equivalent. Otherwise, if a constant is in the table but the source | |
6801 | isn't, set ELT to it. */ | |
6802 | if (src_const_elt && elt | |
6803 | && src_const_elt->first_same_value != elt->first_same_value) | |
6804 | merge_equiv_classes (elt, src_const_elt); | |
6805 | else if (src_const_elt && elt == 0) | |
6806 | elt = src_const_elt; | |
6807 | ||
6808 | /* See if there is a register linearly related to a constant | |
6809 | equivalent of SRC. */ | |
6810 | if (src_const | |
6811 | && (GET_CODE (src_const) == CONST | |
6812 | || (src_const_elt && src_const_elt->related_value != 0))) | |
6813 | { | |
6814 | src_related = use_related_value (src_const, src_const_elt); | |
6815 | if (src_related) | |
6816 | { | |
6817 | struct table_elt *src_related_elt | |
6818 | = lookup (src_related, HASH (src_related, mode), mode); | |
6819 | if (src_related_elt && elt) | |
6820 | { | |
6821 | if (elt->first_same_value | |
6822 | != src_related_elt->first_same_value) | |
6823 | /* This can occur when we previously saw a CONST | |
6824 | involving a SYMBOL_REF and then see the SYMBOL_REF | |
6825 | twice. Merge the involved classes. */ | |
6826 | merge_equiv_classes (elt, src_related_elt); | |
6827 | ||
6828 | src_related = 0; | |
6829 | src_related_elt = 0; | |
6830 | } | |
6831 | else if (src_related_elt && elt == 0) | |
6832 | elt = src_related_elt; | |
6833 | } | |
6834 | } | |
6835 | ||
e4600702 RK |
6836 | /* See if we have a CONST_INT that is already in a register in a |
6837 | wider mode. */ | |
6838 | ||
6839 | if (src_const && src_related == 0 && GET_CODE (src_const) == CONST_INT | |
6840 | && GET_MODE_CLASS (mode) == MODE_INT | |
6841 | && GET_MODE_BITSIZE (mode) < BITS_PER_WORD) | |
6842 | { | |
6843 | enum machine_mode wider_mode; | |
6844 | ||
6845 | for (wider_mode = GET_MODE_WIDER_MODE (mode); | |
6846 | GET_MODE_BITSIZE (wider_mode) <= BITS_PER_WORD | |
6847 | && src_related == 0; | |
6848 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
6849 | { | |
6850 | struct table_elt *const_elt | |
6851 | = lookup (src_const, HASH (src_const, wider_mode), wider_mode); | |
6852 | ||
6853 | if (const_elt == 0) | |
6854 | continue; | |
6855 | ||
6856 | for (const_elt = const_elt->first_same_value; | |
6857 | const_elt; const_elt = const_elt->next_same_value) | |
6858 | if (GET_CODE (const_elt->exp) == REG) | |
6859 | { | |
6860 | src_related = gen_lowpart_if_possible (mode, | |
6861 | const_elt->exp); | |
6862 | break; | |
6863 | } | |
6864 | } | |
6865 | } | |
6866 | ||
d45cf215 RS |
6867 | /* Another possibility is that we have an AND with a constant in |
6868 | a mode narrower than a word. If so, it might have been generated | |
6869 | as part of an "if" which would narrow the AND. If we already | |
6870 | have done the AND in a wider mode, we can use a SUBREG of that | |
6871 | value. */ | |
6872 | ||
6873 | if (flag_expensive_optimizations && ! src_related | |
6874 | && GET_CODE (src) == AND && GET_CODE (XEXP (src, 1)) == CONST_INT | |
6875 | && GET_MODE_SIZE (mode) < UNITS_PER_WORD) | |
6876 | { | |
6877 | enum machine_mode tmode; | |
38a448ca | 6878 | rtx new_and = gen_rtx_AND (VOIDmode, NULL_RTX, XEXP (src, 1)); |
d45cf215 RS |
6879 | |
6880 | for (tmode = GET_MODE_WIDER_MODE (mode); | |
6881 | GET_MODE_SIZE (tmode) <= UNITS_PER_WORD; | |
6882 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
6883 | { | |
6884 | rtx inner = gen_lowpart_if_possible (tmode, XEXP (src, 0)); | |
6885 | struct table_elt *larger_elt; | |
6886 | ||
6887 | if (inner) | |
6888 | { | |
6889 | PUT_MODE (new_and, tmode); | |
6890 | XEXP (new_and, 0) = inner; | |
6891 | larger_elt = lookup (new_and, HASH (new_and, tmode), tmode); | |
6892 | if (larger_elt == 0) | |
6893 | continue; | |
6894 | ||
6895 | for (larger_elt = larger_elt->first_same_value; | |
6896 | larger_elt; larger_elt = larger_elt->next_same_value) | |
6897 | if (GET_CODE (larger_elt->exp) == REG) | |
6898 | { | |
6899 | src_related | |
6900 | = gen_lowpart_if_possible (mode, larger_elt->exp); | |
6901 | break; | |
6902 | } | |
6903 | ||
6904 | if (src_related) | |
6905 | break; | |
6906 | } | |
6907 | } | |
6908 | } | |
7bac1be0 RK |
6909 | |
6910 | #ifdef LOAD_EXTEND_OP | |
6911 | /* See if a MEM has already been loaded with a widening operation; | |
6912 | if it has, we can use a subreg of that. Many CISC machines | |
6913 | also have such operations, but this is only likely to be | |
6914 | beneficial these machines. */ | |
6915 | ||
6916 | if (flag_expensive_optimizations && src_related == 0 | |
6917 | && (GET_MODE_SIZE (mode) < UNITS_PER_WORD) | |
6918 | && GET_MODE_CLASS (mode) == MODE_INT | |
6919 | && GET_CODE (src) == MEM && ! do_not_record | |
6920 | && LOAD_EXTEND_OP (mode) != NIL) | |
6921 | { | |
6922 | enum machine_mode tmode; | |
6923 | ||
6924 | /* Set what we are trying to extend and the operation it might | |
6925 | have been extended with. */ | |
6926 | PUT_CODE (memory_extend_rtx, LOAD_EXTEND_OP (mode)); | |
6927 | XEXP (memory_extend_rtx, 0) = src; | |
6928 | ||
6929 | for (tmode = GET_MODE_WIDER_MODE (mode); | |
6930 | GET_MODE_SIZE (tmode) <= UNITS_PER_WORD; | |
6931 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
6932 | { | |
6933 | struct table_elt *larger_elt; | |
6934 | ||
6935 | PUT_MODE (memory_extend_rtx, tmode); | |
6936 | larger_elt = lookup (memory_extend_rtx, | |
6937 | HASH (memory_extend_rtx, tmode), tmode); | |
6938 | if (larger_elt == 0) | |
6939 | continue; | |
6940 | ||
6941 | for (larger_elt = larger_elt->first_same_value; | |
6942 | larger_elt; larger_elt = larger_elt->next_same_value) | |
6943 | if (GET_CODE (larger_elt->exp) == REG) | |
6944 | { | |
6945 | src_related = gen_lowpart_if_possible (mode, | |
6946 | larger_elt->exp); | |
6947 | break; | |
6948 | } | |
6949 | ||
6950 | if (src_related) | |
6951 | break; | |
6952 | } | |
6953 | } | |
6954 | #endif /* LOAD_EXTEND_OP */ | |
6955 | ||
7afe21cc RK |
6956 | if (src == src_folded) |
6957 | src_folded = 0; | |
6958 | ||
6959 | /* At this point, ELT, if non-zero, points to a class of expressions | |
6960 | equivalent to the source of this SET and SRC, SRC_EQV, SRC_FOLDED, | |
6961 | and SRC_RELATED, if non-zero, each contain additional equivalent | |
6962 | expressions. Prune these latter expressions by deleting expressions | |
6963 | already in the equivalence class. | |
6964 | ||
6965 | Check for an equivalent identical to the destination. If found, | |
6966 | this is the preferred equivalent since it will likely lead to | |
6967 | elimination of the insn. Indicate this by placing it in | |
6968 | `src_related'. */ | |
6969 | ||
6970 | if (elt) elt = elt->first_same_value; | |
6971 | for (p = elt; p; p = p->next_same_value) | |
6972 | { | |
6973 | enum rtx_code code = GET_CODE (p->exp); | |
6974 | ||
6975 | /* If the expression is not valid, ignore it. Then we do not | |
6976 | have to check for validity below. In most cases, we can use | |
6977 | `rtx_equal_p', since canonicalization has already been done. */ | |
6978 | if (code != REG && ! exp_equiv_p (p->exp, p->exp, 1, 0)) | |
6979 | continue; | |
6980 | ||
5a03c8c4 RK |
6981 | /* Also skip paradoxical subregs, unless that's what we're |
6982 | looking for. */ | |
6983 | if (code == SUBREG | |
6984 | && (GET_MODE_SIZE (GET_MODE (p->exp)) | |
6985 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp)))) | |
6986 | && ! (src != 0 | |
6987 | && GET_CODE (src) == SUBREG | |
6988 | && GET_MODE (src) == GET_MODE (p->exp) | |
6989 | && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))) | |
6990 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp)))))) | |
6991 | continue; | |
6992 | ||
7afe21cc RK |
6993 | if (src && GET_CODE (src) == code && rtx_equal_p (src, p->exp)) |
6994 | src = 0; | |
6995 | else if (src_folded && GET_CODE (src_folded) == code | |
6996 | && rtx_equal_p (src_folded, p->exp)) | |
6997 | src_folded = 0; | |
6998 | else if (src_eqv_here && GET_CODE (src_eqv_here) == code | |
6999 | && rtx_equal_p (src_eqv_here, p->exp)) | |
7000 | src_eqv_here = 0; | |
7001 | else if (src_related && GET_CODE (src_related) == code | |
7002 | && rtx_equal_p (src_related, p->exp)) | |
7003 | src_related = 0; | |
7004 | ||
7005 | /* This is the same as the destination of the insns, we want | |
7006 | to prefer it. Copy it to src_related. The code below will | |
7007 | then give it a negative cost. */ | |
7008 | if (GET_CODE (dest) == code && rtx_equal_p (p->exp, dest)) | |
7009 | src_related = dest; | |
7010 | ||
7011 | } | |
7012 | ||
7013 | /* Find the cheapest valid equivalent, trying all the available | |
7014 | possibilities. Prefer items not in the hash table to ones | |
7015 | that are when they are equal cost. Note that we can never | |
7016 | worsen an insn as the current contents will also succeed. | |
05c33dd8 | 7017 | If we find an equivalent identical to the destination, use it as best, |
0f41302f | 7018 | since this insn will probably be eliminated in that case. */ |
7afe21cc RK |
7019 | if (src) |
7020 | { | |
7021 | if (rtx_equal_p (src, dest)) | |
7022 | src_cost = -1; | |
7023 | else | |
7024 | src_cost = COST (src); | |
7025 | } | |
7026 | ||
7027 | if (src_eqv_here) | |
7028 | { | |
7029 | if (rtx_equal_p (src_eqv_here, dest)) | |
7030 | src_eqv_cost = -1; | |
7031 | else | |
7032 | src_eqv_cost = COST (src_eqv_here); | |
7033 | } | |
7034 | ||
7035 | if (src_folded) | |
7036 | { | |
7037 | if (rtx_equal_p (src_folded, dest)) | |
7038 | src_folded_cost = -1; | |
7039 | else | |
7040 | src_folded_cost = COST (src_folded); | |
7041 | } | |
7042 | ||
7043 | if (src_related) | |
7044 | { | |
7045 | if (rtx_equal_p (src_related, dest)) | |
7046 | src_related_cost = -1; | |
7047 | else | |
7048 | src_related_cost = COST (src_related); | |
7049 | } | |
7050 | ||
7051 | /* If this was an indirect jump insn, a known label will really be | |
7052 | cheaper even though it looks more expensive. */ | |
7053 | if (dest == pc_rtx && src_const && GET_CODE (src_const) == LABEL_REF) | |
7054 | src_folded = src_const, src_folded_cost = -1; | |
7055 | ||
7056 | /* Terminate loop when replacement made. This must terminate since | |
7057 | the current contents will be tested and will always be valid. */ | |
7058 | while (1) | |
7059 | { | |
7bd8b2a8 | 7060 | rtx trial, old_src; |
7afe21cc RK |
7061 | |
7062 | /* Skip invalid entries. */ | |
7063 | while (elt && GET_CODE (elt->exp) != REG | |
7064 | && ! exp_equiv_p (elt->exp, elt->exp, 1, 0)) | |
7065 | elt = elt->next_same_value; | |
5a03c8c4 RK |
7066 | |
7067 | /* A paradoxical subreg would be bad here: it'll be the right | |
7068 | size, but later may be adjusted so that the upper bits aren't | |
7069 | what we want. So reject it. */ | |
7070 | if (elt != 0 | |
7071 | && GET_CODE (elt->exp) == SUBREG | |
7072 | && (GET_MODE_SIZE (GET_MODE (elt->exp)) | |
7073 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp)))) | |
7074 | /* It is okay, though, if the rtx we're trying to match | |
7075 | will ignore any of the bits we can't predict. */ | |
7076 | && ! (src != 0 | |
7077 | && GET_CODE (src) == SUBREG | |
7078 | && GET_MODE (src) == GET_MODE (elt->exp) | |
7079 | && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))) | |
7080 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp)))))) | |
7081 | { | |
7082 | elt = elt->next_same_value; | |
7083 | continue; | |
7084 | } | |
7afe21cc RK |
7085 | |
7086 | if (elt) src_elt_cost = elt->cost; | |
7087 | ||
7088 | /* Find cheapest and skip it for the next time. For items | |
7089 | of equal cost, use this order: | |
7090 | src_folded, src, src_eqv, src_related and hash table entry. */ | |
7091 | if (src_folded_cost <= src_cost | |
7092 | && src_folded_cost <= src_eqv_cost | |
7093 | && src_folded_cost <= src_related_cost | |
7094 | && src_folded_cost <= src_elt_cost) | |
7095 | { | |
7096 | trial = src_folded, src_folded_cost = 10000; | |
7097 | if (src_folded_force_flag) | |
7098 | trial = force_const_mem (mode, trial); | |
7099 | } | |
7100 | else if (src_cost <= src_eqv_cost | |
7101 | && src_cost <= src_related_cost | |
7102 | && src_cost <= src_elt_cost) | |
7103 | trial = src, src_cost = 10000; | |
7104 | else if (src_eqv_cost <= src_related_cost | |
7105 | && src_eqv_cost <= src_elt_cost) | |
0af62b41 | 7106 | trial = copy_rtx (src_eqv_here), src_eqv_cost = 10000; |
7afe21cc | 7107 | else if (src_related_cost <= src_elt_cost) |
0af62b41 | 7108 | trial = copy_rtx (src_related), src_related_cost = 10000; |
7afe21cc RK |
7109 | else |
7110 | { | |
05c33dd8 | 7111 | trial = copy_rtx (elt->exp); |
7afe21cc RK |
7112 | elt = elt->next_same_value; |
7113 | src_elt_cost = 10000; | |
7114 | } | |
7115 | ||
7116 | /* We don't normally have an insn matching (set (pc) (pc)), so | |
7117 | check for this separately here. We will delete such an | |
7118 | insn below. | |
7119 | ||
7120 | Tablejump insns contain a USE of the table, so simply replacing | |
7121 | the operand with the constant won't match. This is simply an | |
7122 | unconditional branch, however, and is therefore valid. Just | |
7123 | insert the substitution here and we will delete and re-emit | |
7124 | the insn later. */ | |
7125 | ||
7bd8b2a8 JL |
7126 | /* Keep track of the original SET_SRC so that we can fix notes |
7127 | on libcall instructions. */ | |
7128 | old_src = SET_SRC (sets[i].rtl); | |
7129 | ||
7afe21cc RK |
7130 | if (n_sets == 1 && dest == pc_rtx |
7131 | && (trial == pc_rtx | |
7132 | || (GET_CODE (trial) == LABEL_REF | |
7133 | && ! condjump_p (insn)))) | |
7134 | { | |
7135 | /* If TRIAL is a label in front of a jump table, we are | |
7136 | really falling through the switch (this is how casesi | |
7137 | insns work), so we must branch around the table. */ | |
7138 | if (GET_CODE (trial) == CODE_LABEL | |
7139 | && NEXT_INSN (trial) != 0 | |
7140 | && GET_CODE (NEXT_INSN (trial)) == JUMP_INSN | |
7141 | && (GET_CODE (PATTERN (NEXT_INSN (trial))) == ADDR_DIFF_VEC | |
7142 | || GET_CODE (PATTERN (NEXT_INSN (trial))) == ADDR_VEC)) | |
7143 | ||
38a448ca | 7144 | trial = gen_rtx_LABEL_REF (Pmode, get_label_after (trial)); |
7afe21cc RK |
7145 | |
7146 | SET_SRC (sets[i].rtl) = trial; | |
44333223 | 7147 | cse_jumps_altered = 1; |
7afe21cc RK |
7148 | break; |
7149 | } | |
7150 | ||
7151 | /* Look for a substitution that makes a valid insn. */ | |
7152 | else if (validate_change (insn, &SET_SRC (sets[i].rtl), trial, 0)) | |
05c33dd8 | 7153 | { |
7bd8b2a8 JL |
7154 | /* If we just made a substitution inside a libcall, then we |
7155 | need to make the same substitution in any notes attached | |
7156 | to the RETVAL insn. */ | |
1ed0205e VM |
7157 | if (libcall_insn |
7158 | && (GET_CODE (old_src) == REG | |
7159 | || GET_CODE (old_src) == SUBREG | |
7160 | || GET_CODE (old_src) == MEM)) | |
7bd8b2a8 JL |
7161 | replace_rtx (REG_NOTES (libcall_insn), old_src, |
7162 | canon_reg (SET_SRC (sets[i].rtl), insn)); | |
7163 | ||
7722328e RK |
7164 | /* The result of apply_change_group can be ignored; see |
7165 | canon_reg. */ | |
7166 | ||
7167 | validate_change (insn, &SET_SRC (sets[i].rtl), | |
7168 | canon_reg (SET_SRC (sets[i].rtl), insn), | |
7169 | 1); | |
6702af89 | 7170 | apply_change_group (); |
05c33dd8 RK |
7171 | break; |
7172 | } | |
7afe21cc RK |
7173 | |
7174 | /* If we previously found constant pool entries for | |
7175 | constants and this is a constant, try making a | |
7176 | pool entry. Put it in src_folded unless we already have done | |
7177 | this since that is where it likely came from. */ | |
7178 | ||
7179 | else if (constant_pool_entries_cost | |
7180 | && CONSTANT_P (trial) | |
1bbd065b RK |
7181 | && ! (GET_CODE (trial) == CONST |
7182 | && GET_CODE (XEXP (trial, 0)) == TRUNCATE) | |
7183 | && (src_folded == 0 | |
7184 | || (GET_CODE (src_folded) != MEM | |
7185 | && ! src_folded_force_flag)) | |
9ae8ffe7 JL |
7186 | && GET_MODE_CLASS (mode) != MODE_CC |
7187 | && mode != VOIDmode) | |
7afe21cc RK |
7188 | { |
7189 | src_folded_force_flag = 1; | |
7190 | src_folded = trial; | |
7191 | src_folded_cost = constant_pool_entries_cost; | |
7192 | } | |
7193 | } | |
7194 | ||
7195 | src = SET_SRC (sets[i].rtl); | |
7196 | ||
7197 | /* In general, it is good to have a SET with SET_SRC == SET_DEST. | |
7198 | However, there is an important exception: If both are registers | |
7199 | that are not the head of their equivalence class, replace SET_SRC | |
7200 | with the head of the class. If we do not do this, we will have | |
7201 | both registers live over a portion of the basic block. This way, | |
7202 | their lifetimes will likely abut instead of overlapping. */ | |
7203 | if (GET_CODE (dest) == REG | |
7204 | && REGNO_QTY_VALID_P (REGNO (dest)) | |
30f72379 MM |
7205 | && qty_mode[REG_QTY (REGNO (dest))] == GET_MODE (dest) |
7206 | && qty_first_reg[REG_QTY (REGNO (dest))] != REGNO (dest) | |
7afe21cc RK |
7207 | && GET_CODE (src) == REG && REGNO (src) == REGNO (dest) |
7208 | /* Don't do this if the original insn had a hard reg as | |
7209 | SET_SRC. */ | |
7210 | && (GET_CODE (sets[i].src) != REG | |
7211 | || REGNO (sets[i].src) >= FIRST_PSEUDO_REGISTER)) | |
7212 | /* We can't call canon_reg here because it won't do anything if | |
7213 | SRC is a hard register. */ | |
7214 | { | |
30f72379 | 7215 | int first = qty_first_reg[REG_QTY (REGNO (src))]; |
759bd8b7 R |
7216 | rtx new_src |
7217 | = (first >= FIRST_PSEUDO_REGISTER | |
7218 | ? regno_reg_rtx[first] : gen_rtx_REG (GET_MODE (src), first)); | |
7219 | ||
7220 | /* We must use validate-change even for this, because this | |
7221 | might be a special no-op instruction, suitable only to | |
7222 | tag notes onto. */ | |
7223 | if (validate_change (insn, &SET_SRC (sets[i].rtl), new_src, 0)) | |
7224 | { | |
7225 | src = new_src; | |
7226 | /* If we had a constant that is cheaper than what we are now | |
7227 | setting SRC to, use that constant. We ignored it when we | |
7228 | thought we could make this into a no-op. */ | |
7229 | if (src_const && COST (src_const) < COST (src) | |
7230 | && validate_change (insn, &SET_SRC (sets[i].rtl), src_const, | |
7231 | 0)) | |
7232 | src = src_const; | |
7233 | } | |
7afe21cc RK |
7234 | } |
7235 | ||
7236 | /* If we made a change, recompute SRC values. */ | |
7237 | if (src != sets[i].src) | |
7238 | { | |
7239 | do_not_record = 0; | |
7240 | hash_arg_in_memory = 0; | |
7241 | hash_arg_in_struct = 0; | |
7242 | sets[i].src = src; | |
2197a88a | 7243 | sets[i].src_hash = HASH (src, mode); |
7afe21cc RK |
7244 | sets[i].src_volatile = do_not_record; |
7245 | sets[i].src_in_memory = hash_arg_in_memory; | |
7246 | sets[i].src_in_struct = hash_arg_in_struct; | |
2197a88a | 7247 | sets[i].src_elt = lookup (src, sets[i].src_hash, mode); |
7afe21cc RK |
7248 | } |
7249 | ||
7250 | /* If this is a single SET, we are setting a register, and we have an | |
7251 | equivalent constant, we want to add a REG_NOTE. We don't want | |
7252 | to write a REG_EQUAL note for a constant pseudo since verifying that | |
d45cf215 | 7253 | that pseudo hasn't been eliminated is a pain. Such a note also |
ac7ef8d5 FS |
7254 | won't help anything. |
7255 | ||
7256 | Avoid a REG_EQUAL note for (CONST (MINUS (LABEL_REF) (LABEL_REF))) | |
7257 | which can be created for a reference to a compile time computable | |
7258 | entry in a jump table. */ | |
7259 | ||
7afe21cc | 7260 | if (n_sets == 1 && src_const && GET_CODE (dest) == REG |
ac7ef8d5 FS |
7261 | && GET_CODE (src_const) != REG |
7262 | && ! (GET_CODE (src_const) == CONST | |
7263 | && GET_CODE (XEXP (src_const, 0)) == MINUS | |
7264 | && GET_CODE (XEXP (XEXP (src_const, 0), 0)) == LABEL_REF | |
7265 | && GET_CODE (XEXP (XEXP (src_const, 0), 1)) == LABEL_REF)) | |
7afe21cc | 7266 | { |
92f9aa51 | 7267 | tem = find_reg_note (insn, REG_EQUAL, NULL_RTX); |
7afe21cc | 7268 | |
51e2a951 AS |
7269 | /* Make sure that the rtx is not shared with any other insn. */ |
7270 | src_const = copy_rtx (src_const); | |
7271 | ||
7afe21cc RK |
7272 | /* Record the actual constant value in a REG_EQUAL note, making |
7273 | a new one if one does not already exist. */ | |
7274 | if (tem) | |
7275 | XEXP (tem, 0) = src_const; | |
7276 | else | |
38a448ca RH |
7277 | REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, |
7278 | src_const, REG_NOTES (insn)); | |
7afe21cc RK |
7279 | |
7280 | /* If storing a constant value in a register that | |
7281 | previously held the constant value 0, | |
7282 | record this fact with a REG_WAS_0 note on this insn. | |
7283 | ||
7284 | Note that the *register* is required to have previously held 0, | |
7285 | not just any register in the quantity and we must point to the | |
7286 | insn that set that register to zero. | |
7287 | ||
7288 | Rather than track each register individually, we just see if | |
7289 | the last set for this quantity was for this register. */ | |
7290 | ||
7291 | if (REGNO_QTY_VALID_P (REGNO (dest)) | |
30f72379 | 7292 | && qty_const[REG_QTY (REGNO (dest))] == const0_rtx) |
7afe21cc RK |
7293 | { |
7294 | /* See if we previously had a REG_WAS_0 note. */ | |
906c4e36 | 7295 | rtx note = find_reg_note (insn, REG_WAS_0, NULL_RTX); |
30f72379 | 7296 | rtx const_insn = qty_const_insn[REG_QTY (REGNO (dest))]; |
7afe21cc RK |
7297 | |
7298 | if ((tem = single_set (const_insn)) != 0 | |
7299 | && rtx_equal_p (SET_DEST (tem), dest)) | |
7300 | { | |
7301 | if (note) | |
7302 | XEXP (note, 0) = const_insn; | |
7303 | else | |
38a448ca RH |
7304 | REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_WAS_0, |
7305 | const_insn, | |
7306 | REG_NOTES (insn)); | |
7afe21cc RK |
7307 | } |
7308 | } | |
7309 | } | |
7310 | ||
7311 | /* Now deal with the destination. */ | |
7312 | do_not_record = 0; | |
7313 | sets[i].inner_dest_loc = &SET_DEST (sets[0].rtl); | |
7314 | ||
7315 | /* Look within any SIGN_EXTRACT or ZERO_EXTRACT | |
7316 | to the MEM or REG within it. */ | |
7317 | while (GET_CODE (dest) == SIGN_EXTRACT | |
7318 | || GET_CODE (dest) == ZERO_EXTRACT | |
7319 | || GET_CODE (dest) == SUBREG | |
7320 | || GET_CODE (dest) == STRICT_LOW_PART) | |
7321 | { | |
7322 | sets[i].inner_dest_loc = &XEXP (dest, 0); | |
7323 | dest = XEXP (dest, 0); | |
7324 | } | |
7325 | ||
7326 | sets[i].inner_dest = dest; | |
7327 | ||
7328 | if (GET_CODE (dest) == MEM) | |
7329 | { | |
9ae8ffe7 JL |
7330 | #ifdef PUSH_ROUNDING |
7331 | /* Stack pushes invalidate the stack pointer. */ | |
7332 | rtx addr = XEXP (dest, 0); | |
7333 | if ((GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC | |
7334 | || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC) | |
7335 | && XEXP (addr, 0) == stack_pointer_rtx) | |
7336 | invalidate (stack_pointer_rtx, Pmode); | |
7337 | #endif | |
7afe21cc | 7338 | dest = fold_rtx (dest, insn); |
7afe21cc RK |
7339 | } |
7340 | ||
7341 | /* Compute the hash code of the destination now, | |
7342 | before the effects of this instruction are recorded, | |
7343 | since the register values used in the address computation | |
7344 | are those before this instruction. */ | |
2197a88a | 7345 | sets[i].dest_hash = HASH (dest, mode); |
7afe21cc RK |
7346 | |
7347 | /* Don't enter a bit-field in the hash table | |
7348 | because the value in it after the store | |
7349 | may not equal what was stored, due to truncation. */ | |
7350 | ||
7351 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT | |
7352 | || GET_CODE (SET_DEST (sets[i].rtl)) == SIGN_EXTRACT) | |
7353 | { | |
7354 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
7355 | ||
7356 | if (src_const != 0 && GET_CODE (src_const) == CONST_INT | |
7357 | && GET_CODE (width) == CONST_INT | |
906c4e36 RK |
7358 | && INTVAL (width) < HOST_BITS_PER_WIDE_INT |
7359 | && ! (INTVAL (src_const) | |
7360 | & ((HOST_WIDE_INT) (-1) << INTVAL (width)))) | |
7afe21cc RK |
7361 | /* Exception: if the value is constant, |
7362 | and it won't be truncated, record it. */ | |
7363 | ; | |
7364 | else | |
7365 | { | |
7366 | /* This is chosen so that the destination will be invalidated | |
7367 | but no new value will be recorded. | |
7368 | We must invalidate because sometimes constant | |
7369 | values can be recorded for bitfields. */ | |
7370 | sets[i].src_elt = 0; | |
7371 | sets[i].src_volatile = 1; | |
7372 | src_eqv = 0; | |
7373 | src_eqv_elt = 0; | |
7374 | } | |
7375 | } | |
7376 | ||
7377 | /* If only one set in a JUMP_INSN and it is now a no-op, we can delete | |
7378 | the insn. */ | |
7379 | else if (n_sets == 1 && dest == pc_rtx && src == pc_rtx) | |
7380 | { | |
7381 | PUT_CODE (insn, NOTE); | |
7382 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
7383 | NOTE_SOURCE_FILE (insn) = 0; | |
7384 | cse_jumps_altered = 1; | |
7385 | /* One less use of the label this insn used to jump to. */ | |
85c3ba60 JL |
7386 | if (JUMP_LABEL (insn) != 0) |
7387 | --LABEL_NUSES (JUMP_LABEL (insn)); | |
7afe21cc RK |
7388 | /* No more processing for this set. */ |
7389 | sets[i].rtl = 0; | |
7390 | } | |
7391 | ||
7392 | /* If this SET is now setting PC to a label, we know it used to | |
7393 | be a conditional or computed branch. So we see if we can follow | |
7394 | it. If it was a computed branch, delete it and re-emit. */ | |
7395 | else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF) | |
7396 | { | |
7397 | rtx p; | |
7398 | ||
7399 | /* If this is not in the format for a simple branch and | |
7400 | we are the only SET in it, re-emit it. */ | |
7401 | if (! simplejump_p (insn) && n_sets == 1) | |
7402 | { | |
7403 | rtx new = emit_jump_insn_before (gen_jump (XEXP (src, 0)), insn); | |
7404 | JUMP_LABEL (new) = XEXP (src, 0); | |
7405 | LABEL_NUSES (XEXP (src, 0))++; | |
7406 | delete_insn (insn); | |
7407 | insn = new; | |
7408 | } | |
31dcf83f RS |
7409 | else |
7410 | /* Otherwise, force rerecognition, since it probably had | |
7411 | a different pattern before. | |
7412 | This shouldn't really be necessary, since whatever | |
7413 | changed the source value above should have done this. | |
7414 | Until the right place is found, might as well do this here. */ | |
7415 | INSN_CODE (insn) = -1; | |
7afe21cc RK |
7416 | |
7417 | /* Now that we've converted this jump to an unconditional jump, | |
7418 | there is dead code after it. Delete the dead code until we | |
7419 | reach a BARRIER, the end of the function, or a label. Do | |
7420 | not delete NOTEs except for NOTE_INSN_DELETED since later | |
7421 | phases assume these notes are retained. */ | |
7422 | ||
312f6255 GK |
7423 | never_reached_warning (insn); |
7424 | ||
7afe21cc RK |
7425 | p = insn; |
7426 | ||
7427 | while (NEXT_INSN (p) != 0 | |
7428 | && GET_CODE (NEXT_INSN (p)) != BARRIER | |
7429 | && GET_CODE (NEXT_INSN (p)) != CODE_LABEL) | |
7430 | { | |
eec9ef57 JL |
7431 | /* Note, we must update P with the return value from |
7432 | delete_insn, otherwise we could get an infinite loop | |
7433 | if NEXT_INSN (p) had INSN_DELETED_P set. */ | |
7afe21cc RK |
7434 | if (GET_CODE (NEXT_INSN (p)) != NOTE |
7435 | || NOTE_LINE_NUMBER (NEXT_INSN (p)) == NOTE_INSN_DELETED) | |
778e0677 | 7436 | p = PREV_INSN (delete_insn (NEXT_INSN (p))); |
7afe21cc RK |
7437 | else |
7438 | p = NEXT_INSN (p); | |
7439 | } | |
7440 | ||
7441 | /* If we don't have a BARRIER immediately after INSN, put one there. | |
7442 | Much code assumes that there are no NOTEs between a JUMP_INSN and | |
7443 | BARRIER. */ | |
7444 | ||
7445 | if (NEXT_INSN (insn) == 0 | |
7446 | || GET_CODE (NEXT_INSN (insn)) != BARRIER) | |
783e5bca | 7447 | emit_barrier_before (NEXT_INSN (insn)); |
7afe21cc RK |
7448 | |
7449 | /* We might have two BARRIERs separated by notes. Delete the second | |
7450 | one if so. */ | |
7451 | ||
538b78e7 RS |
7452 | if (p != insn && NEXT_INSN (p) != 0 |
7453 | && GET_CODE (NEXT_INSN (p)) == BARRIER) | |
7afe21cc RK |
7454 | delete_insn (NEXT_INSN (p)); |
7455 | ||
7456 | cse_jumps_altered = 1; | |
7457 | sets[i].rtl = 0; | |
7458 | } | |
7459 | ||
c2a47e48 RK |
7460 | /* If destination is volatile, invalidate it and then do no further |
7461 | processing for this assignment. */ | |
7afe21cc RK |
7462 | |
7463 | else if (do_not_record) | |
c2a47e48 RK |
7464 | { |
7465 | if (GET_CODE (dest) == REG || GET_CODE (dest) == SUBREG | |
7466 | || GET_CODE (dest) == MEM) | |
bb4034b3 | 7467 | invalidate (dest, VOIDmode); |
2708da92 RS |
7468 | else if (GET_CODE (dest) == STRICT_LOW_PART |
7469 | || GET_CODE (dest) == ZERO_EXTRACT) | |
bb4034b3 | 7470 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
c2a47e48 RK |
7471 | sets[i].rtl = 0; |
7472 | } | |
7afe21cc RK |
7473 | |
7474 | if (sets[i].rtl != 0 && dest != SET_DEST (sets[i].rtl)) | |
2197a88a | 7475 | sets[i].dest_hash = HASH (SET_DEST (sets[i].rtl), mode); |
7afe21cc RK |
7476 | |
7477 | #ifdef HAVE_cc0 | |
7478 | /* If setting CC0, record what it was set to, or a constant, if it | |
7479 | is equivalent to a constant. If it is being set to a floating-point | |
7480 | value, make a COMPARE with the appropriate constant of 0. If we | |
7481 | don't do this, later code can interpret this as a test against | |
7482 | const0_rtx, which can cause problems if we try to put it into an | |
7483 | insn as a floating-point operand. */ | |
7484 | if (dest == cc0_rtx) | |
7485 | { | |
7486 | this_insn_cc0 = src_const && mode != VOIDmode ? src_const : src; | |
7487 | this_insn_cc0_mode = mode; | |
cbf6a543 | 7488 | if (FLOAT_MODE_P (mode)) |
38a448ca RH |
7489 | this_insn_cc0 = gen_rtx_COMPARE (VOIDmode, this_insn_cc0, |
7490 | CONST0_RTX (mode)); | |
7afe21cc RK |
7491 | } |
7492 | #endif | |
7493 | } | |
7494 | ||
7495 | /* Now enter all non-volatile source expressions in the hash table | |
7496 | if they are not already present. | |
7497 | Record their equivalence classes in src_elt. | |
7498 | This way we can insert the corresponding destinations into | |
7499 | the same classes even if the actual sources are no longer in them | |
7500 | (having been invalidated). */ | |
7501 | ||
7502 | if (src_eqv && src_eqv_elt == 0 && sets[0].rtl != 0 && ! src_eqv_volatile | |
7503 | && ! rtx_equal_p (src_eqv, SET_DEST (sets[0].rtl))) | |
7504 | { | |
7505 | register struct table_elt *elt; | |
7506 | register struct table_elt *classp = sets[0].src_elt; | |
7507 | rtx dest = SET_DEST (sets[0].rtl); | |
7508 | enum machine_mode eqvmode = GET_MODE (dest); | |
7509 | ||
7510 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
7511 | { | |
7512 | eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0))); | |
7513 | classp = 0; | |
7514 | } | |
7515 | if (insert_regs (src_eqv, classp, 0)) | |
8ae2b8f6 JW |
7516 | { |
7517 | rehash_using_reg (src_eqv); | |
7518 | src_eqv_hash = HASH (src_eqv, eqvmode); | |
7519 | } | |
2197a88a | 7520 | elt = insert (src_eqv, classp, src_eqv_hash, eqvmode); |
7afe21cc RK |
7521 | elt->in_memory = src_eqv_in_memory; |
7522 | elt->in_struct = src_eqv_in_struct; | |
7523 | src_eqv_elt = elt; | |
f7911249 JW |
7524 | |
7525 | /* Check to see if src_eqv_elt is the same as a set source which | |
7526 | does not yet have an elt, and if so set the elt of the set source | |
7527 | to src_eqv_elt. */ | |
7528 | for (i = 0; i < n_sets; i++) | |
7529 | if (sets[i].rtl && sets[i].src_elt == 0 | |
7530 | && rtx_equal_p (SET_SRC (sets[i].rtl), src_eqv)) | |
7531 | sets[i].src_elt = src_eqv_elt; | |
7afe21cc RK |
7532 | } |
7533 | ||
7534 | for (i = 0; i < n_sets; i++) | |
7535 | if (sets[i].rtl && ! sets[i].src_volatile | |
7536 | && ! rtx_equal_p (SET_SRC (sets[i].rtl), SET_DEST (sets[i].rtl))) | |
7537 | { | |
7538 | if (GET_CODE (SET_DEST (sets[i].rtl)) == STRICT_LOW_PART) | |
7539 | { | |
7540 | /* REG_EQUAL in setting a STRICT_LOW_PART | |
7541 | gives an equivalent for the entire destination register, | |
7542 | not just for the subreg being stored in now. | |
7543 | This is a more interesting equivalence, so we arrange later | |
7544 | to treat the entire reg as the destination. */ | |
7545 | sets[i].src_elt = src_eqv_elt; | |
2197a88a | 7546 | sets[i].src_hash = src_eqv_hash; |
7afe21cc RK |
7547 | } |
7548 | else | |
7549 | { | |
7550 | /* Insert source and constant equivalent into hash table, if not | |
7551 | already present. */ | |
7552 | register struct table_elt *classp = src_eqv_elt; | |
7553 | register rtx src = sets[i].src; | |
7554 | register rtx dest = SET_DEST (sets[i].rtl); | |
7555 | enum machine_mode mode | |
7556 | = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src); | |
7557 | ||
15c68354 R |
7558 | /* Don't put a hard register source into the table if this is |
7559 | the last insn of a libcall. */ | |
7560 | if (sets[i].src_elt == 0 | |
7561 | && (GET_CODE (src) != REG | |
7562 | || REGNO (src) >= FIRST_PSEUDO_REGISTER | |
7563 | || ! find_reg_note (insn, REG_RETVAL, NULL_RTX))) | |
7afe21cc RK |
7564 | { |
7565 | register struct table_elt *elt; | |
7566 | ||
7567 | /* Note that these insert_regs calls cannot remove | |
7568 | any of the src_elt's, because they would have failed to | |
7569 | match if not still valid. */ | |
7570 | if (insert_regs (src, classp, 0)) | |
8ae2b8f6 JW |
7571 | { |
7572 | rehash_using_reg (src); | |
7573 | sets[i].src_hash = HASH (src, mode); | |
7574 | } | |
2197a88a | 7575 | elt = insert (src, classp, sets[i].src_hash, mode); |
7afe21cc RK |
7576 | elt->in_memory = sets[i].src_in_memory; |
7577 | elt->in_struct = sets[i].src_in_struct; | |
7578 | sets[i].src_elt = classp = elt; | |
7579 | } | |
7580 | ||
7581 | if (sets[i].src_const && sets[i].src_const_elt == 0 | |
7582 | && src != sets[i].src_const | |
7583 | && ! rtx_equal_p (sets[i].src_const, src)) | |
7584 | sets[i].src_elt = insert (sets[i].src_const, classp, | |
2197a88a | 7585 | sets[i].src_const_hash, mode); |
7afe21cc RK |
7586 | } |
7587 | } | |
7588 | else if (sets[i].src_elt == 0) | |
7589 | /* If we did not insert the source into the hash table (e.g., it was | |
7590 | volatile), note the equivalence class for the REG_EQUAL value, if any, | |
7591 | so that the destination goes into that class. */ | |
7592 | sets[i].src_elt = src_eqv_elt; | |
7593 | ||
9ae8ffe7 | 7594 | invalidate_from_clobbers (x); |
77fa0940 RK |
7595 | |
7596 | /* Some registers are invalidated by subroutine calls. Memory is | |
7597 | invalidated by non-constant calls. */ | |
7598 | ||
7afe21cc RK |
7599 | if (GET_CODE (insn) == CALL_INSN) |
7600 | { | |
77fa0940 | 7601 | if (! CONST_CALL_P (insn)) |
9ae8ffe7 | 7602 | invalidate_memory (); |
7afe21cc RK |
7603 | invalidate_for_call (); |
7604 | } | |
7605 | ||
7606 | /* Now invalidate everything set by this instruction. | |
7607 | If a SUBREG or other funny destination is being set, | |
7608 | sets[i].rtl is still nonzero, so here we invalidate the reg | |
7609 | a part of which is being set. */ | |
7610 | ||
7611 | for (i = 0; i < n_sets; i++) | |
7612 | if (sets[i].rtl) | |
7613 | { | |
bb4034b3 JW |
7614 | /* We can't use the inner dest, because the mode associated with |
7615 | a ZERO_EXTRACT is significant. */ | |
7616 | register rtx dest = SET_DEST (sets[i].rtl); | |
7afe21cc RK |
7617 | |
7618 | /* Needed for registers to remove the register from its | |
7619 | previous quantity's chain. | |
7620 | Needed for memory if this is a nonvarying address, unless | |
7621 | we have just done an invalidate_memory that covers even those. */ | |
7622 | if (GET_CODE (dest) == REG || GET_CODE (dest) == SUBREG | |
9ae8ffe7 | 7623 | || GET_CODE (dest) == MEM) |
bb4034b3 | 7624 | invalidate (dest, VOIDmode); |
2708da92 RS |
7625 | else if (GET_CODE (dest) == STRICT_LOW_PART |
7626 | || GET_CODE (dest) == ZERO_EXTRACT) | |
bb4034b3 | 7627 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
7afe21cc RK |
7628 | } |
7629 | ||
01e752d3 JL |
7630 | /* A volatile ASM invalidates everything. */ |
7631 | if (GET_CODE (insn) == INSN | |
7632 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
7633 | && MEM_VOLATILE_P (PATTERN (insn))) | |
7634 | flush_hash_table (); | |
7635 | ||
7afe21cc RK |
7636 | /* Make sure registers mentioned in destinations |
7637 | are safe for use in an expression to be inserted. | |
7638 | This removes from the hash table | |
7639 | any invalid entry that refers to one of these registers. | |
7640 | ||
7641 | We don't care about the return value from mention_regs because | |
7642 | we are going to hash the SET_DEST values unconditionally. */ | |
7643 | ||
7644 | for (i = 0; i < n_sets; i++) | |
34c73909 R |
7645 | { |
7646 | if (sets[i].rtl) | |
7647 | { | |
7648 | rtx x = SET_DEST (sets[i].rtl); | |
7649 | ||
7650 | if (GET_CODE (x) != REG) | |
7651 | mention_regs (x); | |
7652 | else | |
7653 | { | |
7654 | /* We used to rely on all references to a register becoming | |
7655 | inaccessible when a register changes to a new quantity, | |
7656 | since that changes the hash code. However, that is not | |
7657 | safe, since after NBUCKETS new quantities we get a | |
7658 | hash 'collision' of a register with its own invalid | |
7659 | entries. And since SUBREGs have been changed not to | |
7660 | change their hash code with the hash code of the register, | |
7661 | it wouldn't work any longer at all. So we have to check | |
7662 | for any invalid references lying around now. | |
7663 | This code is similar to the REG case in mention_regs, | |
7664 | but it knows that reg_tick has been incremented, and | |
7665 | it leaves reg_in_table as -1 . */ | |
7666 | register int regno = REGNO (x); | |
7667 | register int endregno | |
7668 | = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1 | |
7669 | : HARD_REGNO_NREGS (regno, GET_MODE (x))); | |
7670 | int i; | |
7671 | ||
7672 | for (i = regno; i < endregno; i++) | |
7673 | { | |
30f72379 | 7674 | if (REG_IN_TABLE (i) >= 0) |
34c73909 R |
7675 | { |
7676 | remove_invalid_refs (i); | |
30f72379 | 7677 | REG_IN_TABLE (i) = -1; |
34c73909 R |
7678 | } |
7679 | } | |
7680 | } | |
7681 | } | |
7682 | } | |
7afe21cc RK |
7683 | |
7684 | /* We may have just removed some of the src_elt's from the hash table. | |
7685 | So replace each one with the current head of the same class. */ | |
7686 | ||
7687 | for (i = 0; i < n_sets; i++) | |
7688 | if (sets[i].rtl) | |
7689 | { | |
7690 | if (sets[i].src_elt && sets[i].src_elt->first_same_value == 0) | |
7691 | /* If elt was removed, find current head of same class, | |
7692 | or 0 if nothing remains of that class. */ | |
7693 | { | |
7694 | register struct table_elt *elt = sets[i].src_elt; | |
7695 | ||
7696 | while (elt && elt->prev_same_value) | |
7697 | elt = elt->prev_same_value; | |
7698 | ||
7699 | while (elt && elt->first_same_value == 0) | |
7700 | elt = elt->next_same_value; | |
7701 | sets[i].src_elt = elt ? elt->first_same_value : 0; | |
7702 | } | |
7703 | } | |
7704 | ||
7705 | /* Now insert the destinations into their equivalence classes. */ | |
7706 | ||
7707 | for (i = 0; i < n_sets; i++) | |
7708 | if (sets[i].rtl) | |
7709 | { | |
7710 | register rtx dest = SET_DEST (sets[i].rtl); | |
9de2c71a | 7711 | rtx inner_dest = sets[i].inner_dest; |
7afe21cc RK |
7712 | register struct table_elt *elt; |
7713 | ||
7714 | /* Don't record value if we are not supposed to risk allocating | |
7715 | floating-point values in registers that might be wider than | |
7716 | memory. */ | |
7717 | if ((flag_float_store | |
7718 | && GET_CODE (dest) == MEM | |
cbf6a543 | 7719 | && FLOAT_MODE_P (GET_MODE (dest))) |
bc4ddc77 JW |
7720 | /* Don't record BLKmode values, because we don't know the |
7721 | size of it, and can't be sure that other BLKmode values | |
7722 | have the same or smaller size. */ | |
7723 | || GET_MODE (dest) == BLKmode | |
7afe21cc RK |
7724 | /* Don't record values of destinations set inside a libcall block |
7725 | since we might delete the libcall. Things should have been set | |
7726 | up so we won't want to reuse such a value, but we play it safe | |
7727 | here. */ | |
7bd8b2a8 | 7728 | || libcall_insn |
7afe21cc RK |
7729 | /* If we didn't put a REG_EQUAL value or a source into the hash |
7730 | table, there is no point is recording DEST. */ | |
1a8e9a8e RK |
7731 | || sets[i].src_elt == 0 |
7732 | /* If DEST is a paradoxical SUBREG and SRC is a ZERO_EXTEND | |
7733 | or SIGN_EXTEND, don't record DEST since it can cause | |
7734 | some tracking to be wrong. | |
7735 | ||
7736 | ??? Think about this more later. */ | |
7737 | || (GET_CODE (dest) == SUBREG | |
7738 | && (GET_MODE_SIZE (GET_MODE (dest)) | |
7739 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))) | |
7740 | && (GET_CODE (sets[i].src) == SIGN_EXTEND | |
7741 | || GET_CODE (sets[i].src) == ZERO_EXTEND))) | |
7afe21cc RK |
7742 | continue; |
7743 | ||
7744 | /* STRICT_LOW_PART isn't part of the value BEING set, | |
7745 | and neither is the SUBREG inside it. | |
7746 | Note that in this case SETS[I].SRC_ELT is really SRC_EQV_ELT. */ | |
7747 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
7748 | dest = SUBREG_REG (XEXP (dest, 0)); | |
7749 | ||
c610adec | 7750 | if (GET_CODE (dest) == REG || GET_CODE (dest) == SUBREG) |
7afe21cc RK |
7751 | /* Registers must also be inserted into chains for quantities. */ |
7752 | if (insert_regs (dest, sets[i].src_elt, 1)) | |
8ae2b8f6 JW |
7753 | { |
7754 | /* If `insert_regs' changes something, the hash code must be | |
7755 | recalculated. */ | |
7756 | rehash_using_reg (dest); | |
7757 | sets[i].dest_hash = HASH (dest, GET_MODE (dest)); | |
7758 | } | |
7afe21cc | 7759 | |
9de2c71a MM |
7760 | if (GET_CODE (inner_dest) == MEM |
7761 | && GET_CODE (XEXP (inner_dest, 0)) == ADDRESSOF) | |
7762 | /* Given (SET (MEM (ADDRESSOF (X))) Y) we don't want to say | |
7763 | that (MEM (ADDRESSOF (X))) is equivalent to Y. | |
7764 | Consider the case in which the address of the MEM is | |
7765 | passed to a function, which alters the MEM. Then, if we | |
7766 | later use Y instead of the MEM we'll miss the update. */ | |
7767 | elt = insert (dest, 0, sets[i].dest_hash, GET_MODE (dest)); | |
7768 | else | |
7769 | elt = insert (dest, sets[i].src_elt, | |
7770 | sets[i].dest_hash, GET_MODE (dest)); | |
7771 | ||
c256df0b | 7772 | elt->in_memory = (GET_CODE (sets[i].inner_dest) == MEM |
9ad91d71 RK |
7773 | && (! RTX_UNCHANGING_P (sets[i].inner_dest) |
7774 | || FIXED_BASE_PLUS_P (XEXP (sets[i].inner_dest, | |
7775 | 0)))); | |
c256df0b | 7776 | |
7afe21cc RK |
7777 | if (elt->in_memory) |
7778 | { | |
7779 | /* This implicitly assumes a whole struct | |
7780 | need not have MEM_IN_STRUCT_P. | |
7781 | But a whole struct is *supposed* to have MEM_IN_STRUCT_P. */ | |
7782 | elt->in_struct = (MEM_IN_STRUCT_P (sets[i].inner_dest) | |
7783 | || sets[i].inner_dest != SET_DEST (sets[i].rtl)); | |
7784 | } | |
7785 | ||
fc3ffe83 RK |
7786 | /* If we have (set (subreg:m1 (reg:m2 foo) 0) (bar:m1)), M1 is no |
7787 | narrower than M2, and both M1 and M2 are the same number of words, | |
7788 | we are also doing (set (reg:m2 foo) (subreg:m2 (bar:m1) 0)) so | |
7789 | make that equivalence as well. | |
7afe21cc RK |
7790 | |
7791 | However, BAR may have equivalences for which gen_lowpart_if_possible | |
7792 | will produce a simpler value than gen_lowpart_if_possible applied to | |
7793 | BAR (e.g., if BAR was ZERO_EXTENDed from M2), so we will scan all | |
7794 | BAR's equivalences. If we don't get a simplified form, make | |
7795 | the SUBREG. It will not be used in an equivalence, but will | |
7796 | cause two similar assignments to be detected. | |
7797 | ||
7798 | Note the loop below will find SUBREG_REG (DEST) since we have | |
7799 | already entered SRC and DEST of the SET in the table. */ | |
7800 | ||
7801 | if (GET_CODE (dest) == SUBREG | |
6cdbaec4 RK |
7802 | && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) - 1) |
7803 | / UNITS_PER_WORD) | |
7804 | == (GET_MODE_SIZE (GET_MODE (dest)) - 1)/ UNITS_PER_WORD) | |
7afe21cc RK |
7805 | && (GET_MODE_SIZE (GET_MODE (dest)) |
7806 | >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))) | |
7807 | && sets[i].src_elt != 0) | |
7808 | { | |
7809 | enum machine_mode new_mode = GET_MODE (SUBREG_REG (dest)); | |
7810 | struct table_elt *elt, *classp = 0; | |
7811 | ||
7812 | for (elt = sets[i].src_elt->first_same_value; elt; | |
7813 | elt = elt->next_same_value) | |
7814 | { | |
7815 | rtx new_src = 0; | |
2197a88a | 7816 | unsigned src_hash; |
7afe21cc RK |
7817 | struct table_elt *src_elt; |
7818 | ||
7819 | /* Ignore invalid entries. */ | |
7820 | if (GET_CODE (elt->exp) != REG | |
7821 | && ! exp_equiv_p (elt->exp, elt->exp, 1, 0)) | |
7822 | continue; | |
7823 | ||
7824 | new_src = gen_lowpart_if_possible (new_mode, elt->exp); | |
7825 | if (new_src == 0) | |
38a448ca | 7826 | new_src = gen_rtx_SUBREG (new_mode, elt->exp, 0); |
7afe21cc RK |
7827 | |
7828 | src_hash = HASH (new_src, new_mode); | |
7829 | src_elt = lookup (new_src, src_hash, new_mode); | |
7830 | ||
7831 | /* Put the new source in the hash table is if isn't | |
7832 | already. */ | |
7833 | if (src_elt == 0) | |
7834 | { | |
7835 | if (insert_regs (new_src, classp, 0)) | |
8ae2b8f6 JW |
7836 | { |
7837 | rehash_using_reg (new_src); | |
7838 | src_hash = HASH (new_src, new_mode); | |
7839 | } | |
7afe21cc RK |
7840 | src_elt = insert (new_src, classp, src_hash, new_mode); |
7841 | src_elt->in_memory = elt->in_memory; | |
7842 | src_elt->in_struct = elt->in_struct; | |
7843 | } | |
7844 | else if (classp && classp != src_elt->first_same_value) | |
7845 | /* Show that two things that we've seen before are | |
7846 | actually the same. */ | |
7847 | merge_equiv_classes (src_elt, classp); | |
7848 | ||
7849 | classp = src_elt->first_same_value; | |
da932f04 JL |
7850 | /* Ignore invalid entries. */ |
7851 | while (classp | |
7852 | && GET_CODE (classp->exp) != REG | |
7853 | && ! exp_equiv_p (classp->exp, classp->exp, 1, 0)) | |
7854 | classp = classp->next_same_value; | |
7afe21cc RK |
7855 | } |
7856 | } | |
7857 | } | |
7858 | ||
7859 | /* Special handling for (set REG0 REG1) | |
7860 | where REG0 is the "cheapest", cheaper than REG1. | |
7861 | After cse, REG1 will probably not be used in the sequel, | |
7862 | so (if easily done) change this insn to (set REG1 REG0) and | |
7863 | replace REG1 with REG0 in the previous insn that computed their value. | |
7864 | Then REG1 will become a dead store and won't cloud the situation | |
7865 | for later optimizations. | |
7866 | ||
7867 | Do not make this change if REG1 is a hard register, because it will | |
7868 | then be used in the sequel and we may be changing a two-operand insn | |
7869 | into a three-operand insn. | |
7870 | ||
50270076 R |
7871 | Also do not do this if we are operating on a copy of INSN. |
7872 | ||
7873 | Also don't do this if INSN ends a libcall; this would cause an unrelated | |
7874 | register to be set in the middle of a libcall, and we then get bad code | |
7875 | if the libcall is deleted. */ | |
7afe21cc RK |
7876 | |
7877 | if (n_sets == 1 && sets[0].rtl && GET_CODE (SET_DEST (sets[0].rtl)) == REG | |
7878 | && NEXT_INSN (PREV_INSN (insn)) == insn | |
7879 | && GET_CODE (SET_SRC (sets[0].rtl)) == REG | |
7880 | && REGNO (SET_SRC (sets[0].rtl)) >= FIRST_PSEUDO_REGISTER | |
7881 | && REGNO_QTY_VALID_P (REGNO (SET_SRC (sets[0].rtl))) | |
30f72379 | 7882 | && (qty_first_reg[REG_QTY (REGNO (SET_SRC (sets[0].rtl)))] |
50270076 R |
7883 | == REGNO (SET_DEST (sets[0].rtl))) |
7884 | && ! find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
7afe21cc RK |
7885 | { |
7886 | rtx prev = PREV_INSN (insn); | |
7887 | while (prev && GET_CODE (prev) == NOTE) | |
7888 | prev = PREV_INSN (prev); | |
7889 | ||
7890 | if (prev && GET_CODE (prev) == INSN && GET_CODE (PATTERN (prev)) == SET | |
7891 | && SET_DEST (PATTERN (prev)) == SET_SRC (sets[0].rtl)) | |
7892 | { | |
7893 | rtx dest = SET_DEST (sets[0].rtl); | |
906c4e36 | 7894 | rtx note = find_reg_note (prev, REG_EQUIV, NULL_RTX); |
7afe21cc RK |
7895 | |
7896 | validate_change (prev, & SET_DEST (PATTERN (prev)), dest, 1); | |
7897 | validate_change (insn, & SET_DEST (sets[0].rtl), | |
7898 | SET_SRC (sets[0].rtl), 1); | |
7899 | validate_change (insn, & SET_SRC (sets[0].rtl), dest, 1); | |
7900 | apply_change_group (); | |
7901 | ||
7902 | /* If REG1 was equivalent to a constant, REG0 is not. */ | |
7903 | if (note) | |
7904 | PUT_REG_NOTE_KIND (note, REG_EQUAL); | |
7905 | ||
7906 | /* If there was a REG_WAS_0 note on PREV, remove it. Move | |
7907 | any REG_WAS_0 note on INSN to PREV. */ | |
906c4e36 | 7908 | note = find_reg_note (prev, REG_WAS_0, NULL_RTX); |
7afe21cc RK |
7909 | if (note) |
7910 | remove_note (prev, note); | |
7911 | ||
906c4e36 | 7912 | note = find_reg_note (insn, REG_WAS_0, NULL_RTX); |
7afe21cc RK |
7913 | if (note) |
7914 | { | |
7915 | remove_note (insn, note); | |
7916 | XEXP (note, 1) = REG_NOTES (prev); | |
7917 | REG_NOTES (prev) = note; | |
7918 | } | |
98369a0f RK |
7919 | |
7920 | /* If INSN has a REG_EQUAL note, and this note mentions REG0, | |
7921 | then we must delete it, because the value in REG0 has changed. */ | |
7922 | note = find_reg_note (insn, REG_EQUAL, NULL_RTX); | |
7923 | if (note && reg_mentioned_p (dest, XEXP (note, 0))) | |
7924 | remove_note (insn, note); | |
7afe21cc RK |
7925 | } |
7926 | } | |
7927 | ||
7928 | /* If this is a conditional jump insn, record any known equivalences due to | |
7929 | the condition being tested. */ | |
7930 | ||
7931 | last_jump_equiv_class = 0; | |
7932 | if (GET_CODE (insn) == JUMP_INSN | |
7933 | && n_sets == 1 && GET_CODE (x) == SET | |
7934 | && GET_CODE (SET_SRC (x)) == IF_THEN_ELSE) | |
7935 | record_jump_equiv (insn, 0); | |
7936 | ||
7937 | #ifdef HAVE_cc0 | |
7938 | /* If the previous insn set CC0 and this insn no longer references CC0, | |
7939 | delete the previous insn. Here we use the fact that nothing expects CC0 | |
7940 | to be valid over an insn, which is true until the final pass. */ | |
7941 | if (prev_insn && GET_CODE (prev_insn) == INSN | |
7942 | && (tem = single_set (prev_insn)) != 0 | |
7943 | && SET_DEST (tem) == cc0_rtx | |
7944 | && ! reg_mentioned_p (cc0_rtx, x)) | |
7945 | { | |
7946 | PUT_CODE (prev_insn, NOTE); | |
7947 | NOTE_LINE_NUMBER (prev_insn) = NOTE_INSN_DELETED; | |
7948 | NOTE_SOURCE_FILE (prev_insn) = 0; | |
7949 | } | |
7950 | ||
7951 | prev_insn_cc0 = this_insn_cc0; | |
7952 | prev_insn_cc0_mode = this_insn_cc0_mode; | |
7953 | #endif | |
7954 | ||
7955 | prev_insn = insn; | |
7956 | } | |
7957 | \f | |
a4c6502a | 7958 | /* Remove from the hash table all expressions that reference memory. */ |
7afe21cc | 7959 | static void |
9ae8ffe7 | 7960 | invalidate_memory () |
7afe21cc | 7961 | { |
9ae8ffe7 JL |
7962 | register int i; |
7963 | register struct table_elt *p, *next; | |
7afe21cc | 7964 | |
9ae8ffe7 JL |
7965 | for (i = 0; i < NBUCKETS; i++) |
7966 | for (p = table[i]; p; p = next) | |
7967 | { | |
7968 | next = p->next_same_hash; | |
7969 | if (p->in_memory) | |
7970 | remove_from_table (p, i); | |
7971 | } | |
7972 | } | |
7973 | ||
7974 | /* XXX ??? The name of this function bears little resemblance to | |
7975 | what this function actually does. FIXME. */ | |
7976 | static int | |
7977 | note_mem_written (addr) | |
7978 | register rtx addr; | |
7979 | { | |
7980 | /* Pushing or popping the stack invalidates just the stack pointer. */ | |
7981 | if ((GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC | |
7982 | || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC) | |
7983 | && GET_CODE (XEXP (addr, 0)) == REG | |
7984 | && REGNO (XEXP (addr, 0)) == STACK_POINTER_REGNUM) | |
7afe21cc | 7985 | { |
30f72379 MM |
7986 | if (REG_TICK (STACK_POINTER_REGNUM) >= 0) |
7987 | REG_TICK (STACK_POINTER_REGNUM)++; | |
9ae8ffe7 JL |
7988 | |
7989 | /* This should be *very* rare. */ | |
7990 | if (TEST_HARD_REG_BIT (hard_regs_in_table, STACK_POINTER_REGNUM)) | |
7991 | invalidate (stack_pointer_rtx, VOIDmode); | |
7992 | return 1; | |
7afe21cc | 7993 | } |
9ae8ffe7 | 7994 | return 0; |
7afe21cc RK |
7995 | } |
7996 | ||
7997 | /* Perform invalidation on the basis of everything about an insn | |
7998 | except for invalidating the actual places that are SET in it. | |
7999 | This includes the places CLOBBERed, and anything that might | |
8000 | alias with something that is SET or CLOBBERed. | |
8001 | ||
7afe21cc RK |
8002 | X is the pattern of the insn. */ |
8003 | ||
8004 | static void | |
9ae8ffe7 | 8005 | invalidate_from_clobbers (x) |
7afe21cc RK |
8006 | rtx x; |
8007 | { | |
7afe21cc RK |
8008 | if (GET_CODE (x) == CLOBBER) |
8009 | { | |
8010 | rtx ref = XEXP (x, 0); | |
9ae8ffe7 JL |
8011 | if (ref) |
8012 | { | |
8013 | if (GET_CODE (ref) == REG || GET_CODE (ref) == SUBREG | |
8014 | || GET_CODE (ref) == MEM) | |
8015 | invalidate (ref, VOIDmode); | |
8016 | else if (GET_CODE (ref) == STRICT_LOW_PART | |
8017 | || GET_CODE (ref) == ZERO_EXTRACT) | |
8018 | invalidate (XEXP (ref, 0), GET_MODE (ref)); | |
8019 | } | |
7afe21cc RK |
8020 | } |
8021 | else if (GET_CODE (x) == PARALLEL) | |
8022 | { | |
8023 | register int i; | |
8024 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
8025 | { | |
8026 | register rtx y = XVECEXP (x, 0, i); | |
8027 | if (GET_CODE (y) == CLOBBER) | |
8028 | { | |
8029 | rtx ref = XEXP (y, 0); | |
9ae8ffe7 JL |
8030 | if (GET_CODE (ref) == REG || GET_CODE (ref) == SUBREG |
8031 | || GET_CODE (ref) == MEM) | |
8032 | invalidate (ref, VOIDmode); | |
8033 | else if (GET_CODE (ref) == STRICT_LOW_PART | |
8034 | || GET_CODE (ref) == ZERO_EXTRACT) | |
8035 | invalidate (XEXP (ref, 0), GET_MODE (ref)); | |
7afe21cc RK |
8036 | } |
8037 | } | |
8038 | } | |
8039 | } | |
8040 | \f | |
8041 | /* Process X, part of the REG_NOTES of an insn. Look at any REG_EQUAL notes | |
8042 | and replace any registers in them with either an equivalent constant | |
8043 | or the canonical form of the register. If we are inside an address, | |
8044 | only do this if the address remains valid. | |
8045 | ||
8046 | OBJECT is 0 except when within a MEM in which case it is the MEM. | |
8047 | ||
8048 | Return the replacement for X. */ | |
8049 | ||
8050 | static rtx | |
8051 | cse_process_notes (x, object) | |
8052 | rtx x; | |
8053 | rtx object; | |
8054 | { | |
8055 | enum rtx_code code = GET_CODE (x); | |
8056 | char *fmt = GET_RTX_FORMAT (code); | |
7afe21cc RK |
8057 | int i; |
8058 | ||
8059 | switch (code) | |
8060 | { | |
8061 | case CONST_INT: | |
8062 | case CONST: | |
8063 | case SYMBOL_REF: | |
8064 | case LABEL_REF: | |
8065 | case CONST_DOUBLE: | |
8066 | case PC: | |
8067 | case CC0: | |
8068 | case LO_SUM: | |
8069 | return x; | |
8070 | ||
8071 | case MEM: | |
8072 | XEXP (x, 0) = cse_process_notes (XEXP (x, 0), x); | |
8073 | return x; | |
8074 | ||
8075 | case EXPR_LIST: | |
8076 | case INSN_LIST: | |
8077 | if (REG_NOTE_KIND (x) == REG_EQUAL) | |
906c4e36 | 8078 | XEXP (x, 0) = cse_process_notes (XEXP (x, 0), NULL_RTX); |
7afe21cc | 8079 | if (XEXP (x, 1)) |
906c4e36 | 8080 | XEXP (x, 1) = cse_process_notes (XEXP (x, 1), NULL_RTX); |
7afe21cc RK |
8081 | return x; |
8082 | ||
e4890d45 RS |
8083 | case SIGN_EXTEND: |
8084 | case ZERO_EXTEND: | |
0b0ee36c | 8085 | case SUBREG: |
e4890d45 RS |
8086 | { |
8087 | rtx new = cse_process_notes (XEXP (x, 0), object); | |
8088 | /* We don't substitute VOIDmode constants into these rtx, | |
8089 | since they would impede folding. */ | |
8090 | if (GET_MODE (new) != VOIDmode) | |
8091 | validate_change (object, &XEXP (x, 0), new, 0); | |
8092 | return x; | |
8093 | } | |
8094 | ||
7afe21cc | 8095 | case REG: |
30f72379 | 8096 | i = REG_QTY (REGNO (x)); |
7afe21cc RK |
8097 | |
8098 | /* Return a constant or a constant register. */ | |
8099 | if (REGNO_QTY_VALID_P (REGNO (x)) | |
8100 | && qty_const[i] != 0 | |
8101 | && (CONSTANT_P (qty_const[i]) | |
8102 | || GET_CODE (qty_const[i]) == REG)) | |
8103 | { | |
8104 | rtx new = gen_lowpart_if_possible (GET_MODE (x), qty_const[i]); | |
8105 | if (new) | |
8106 | return new; | |
8107 | } | |
8108 | ||
8109 | /* Otherwise, canonicalize this register. */ | |
906c4e36 | 8110 | return canon_reg (x, NULL_RTX); |
e9a25f70 JL |
8111 | |
8112 | default: | |
8113 | break; | |
7afe21cc RK |
8114 | } |
8115 | ||
8116 | for (i = 0; i < GET_RTX_LENGTH (code); i++) | |
8117 | if (fmt[i] == 'e') | |
8118 | validate_change (object, &XEXP (x, i), | |
7fe34fdf | 8119 | cse_process_notes (XEXP (x, i), object), 0); |
7afe21cc RK |
8120 | |
8121 | return x; | |
8122 | } | |
8123 | \f | |
8124 | /* Find common subexpressions between the end test of a loop and the beginning | |
8125 | of the loop. LOOP_START is the CODE_LABEL at the start of a loop. | |
8126 | ||
8127 | Often we have a loop where an expression in the exit test is used | |
8128 | in the body of the loop. For example "while (*p) *q++ = *p++;". | |
8129 | Because of the way we duplicate the loop exit test in front of the loop, | |
8130 | however, we don't detect that common subexpression. This will be caught | |
8131 | when global cse is implemented, but this is a quite common case. | |
8132 | ||
8133 | This function handles the most common cases of these common expressions. | |
8134 | It is called after we have processed the basic block ending with the | |
8135 | NOTE_INSN_LOOP_END note that ends a loop and the previous JUMP_INSN | |
8136 | jumps to a label used only once. */ | |
8137 | ||
8138 | static void | |
8139 | cse_around_loop (loop_start) | |
8140 | rtx loop_start; | |
8141 | { | |
8142 | rtx insn; | |
8143 | int i; | |
8144 | struct table_elt *p; | |
8145 | ||
8146 | /* If the jump at the end of the loop doesn't go to the start, we don't | |
8147 | do anything. */ | |
8148 | for (insn = PREV_INSN (loop_start); | |
8149 | insn && (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) >= 0); | |
8150 | insn = PREV_INSN (insn)) | |
8151 | ; | |
8152 | ||
8153 | if (insn == 0 | |
8154 | || GET_CODE (insn) != NOTE | |
8155 | || NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_BEG) | |
8156 | return; | |
8157 | ||
8158 | /* If the last insn of the loop (the end test) was an NE comparison, | |
8159 | we will interpret it as an EQ comparison, since we fell through | |
f72aed24 | 8160 | the loop. Any equivalences resulting from that comparison are |
7afe21cc RK |
8161 | therefore not valid and must be invalidated. */ |
8162 | if (last_jump_equiv_class) | |
8163 | for (p = last_jump_equiv_class->first_same_value; p; | |
8164 | p = p->next_same_value) | |
51723711 KG |
8165 | { |
8166 | if (GET_CODE (p->exp) == MEM || GET_CODE (p->exp) == REG | |
8167 | || (GET_CODE (p->exp) == SUBREG | |
8168 | && GET_CODE (SUBREG_REG (p->exp)) == REG)) | |
8169 | invalidate (p->exp, VOIDmode); | |
8170 | else if (GET_CODE (p->exp) == STRICT_LOW_PART | |
8171 | || GET_CODE (p->exp) == ZERO_EXTRACT) | |
8172 | invalidate (XEXP (p->exp, 0), GET_MODE (p->exp)); | |
8173 | } | |
7afe21cc RK |
8174 | |
8175 | /* Process insns starting after LOOP_START until we hit a CALL_INSN or | |
8176 | a CODE_LABEL (we could handle a CALL_INSN, but it isn't worth it). | |
8177 | ||
8178 | The only thing we do with SET_DEST is invalidate entries, so we | |
8179 | can safely process each SET in order. It is slightly less efficient | |
556c714b JW |
8180 | to do so, but we only want to handle the most common cases. |
8181 | ||
8182 | The gen_move_insn call in cse_set_around_loop may create new pseudos. | |
8183 | These pseudos won't have valid entries in any of the tables indexed | |
8184 | by register number, such as reg_qty. We avoid out-of-range array | |
8185 | accesses by not processing any instructions created after cse started. */ | |
7afe21cc RK |
8186 | |
8187 | for (insn = NEXT_INSN (loop_start); | |
8188 | GET_CODE (insn) != CALL_INSN && GET_CODE (insn) != CODE_LABEL | |
556c714b | 8189 | && INSN_UID (insn) < max_insn_uid |
7afe21cc RK |
8190 | && ! (GET_CODE (insn) == NOTE |
8191 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END); | |
8192 | insn = NEXT_INSN (insn)) | |
8193 | { | |
8194 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
8195 | && (GET_CODE (PATTERN (insn)) == SET | |
8196 | || GET_CODE (PATTERN (insn)) == CLOBBER)) | |
8197 | cse_set_around_loop (PATTERN (insn), insn, loop_start); | |
8198 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
8199 | && GET_CODE (PATTERN (insn)) == PARALLEL) | |
8200 | for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) | |
8201 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET | |
8202 | || GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == CLOBBER) | |
8203 | cse_set_around_loop (XVECEXP (PATTERN (insn), 0, i), insn, | |
8204 | loop_start); | |
8205 | } | |
8206 | } | |
8207 | \f | |
8b3686ed RK |
8208 | /* Process one SET of an insn that was skipped. We ignore CLOBBERs |
8209 | since they are done elsewhere. This function is called via note_stores. */ | |
8210 | ||
8211 | static void | |
8212 | invalidate_skipped_set (dest, set) | |
8213 | rtx set; | |
8214 | rtx dest; | |
8215 | { | |
9ae8ffe7 JL |
8216 | enum rtx_code code = GET_CODE (dest); |
8217 | ||
8218 | if (code == MEM | |
8219 | && ! note_mem_written (dest) /* If this is not a stack push ... */ | |
8220 | /* There are times when an address can appear varying and be a PLUS | |
8221 | during this scan when it would be a fixed address were we to know | |
8222 | the proper equivalences. So invalidate all memory if there is | |
8223 | a BLKmode or nonscalar memory reference or a reference to a | |
8224 | variable address. */ | |
8225 | && (MEM_IN_STRUCT_P (dest) || GET_MODE (dest) == BLKmode | |
8226 | || cse_rtx_varies_p (XEXP (dest, 0)))) | |
8227 | { | |
8228 | invalidate_memory (); | |
8229 | return; | |
8230 | } | |
ffcf6393 | 8231 | |
f47c02fa RK |
8232 | if (GET_CODE (set) == CLOBBER |
8233 | #ifdef HAVE_cc0 | |
8234 | || dest == cc0_rtx | |
8235 | #endif | |
8236 | || dest == pc_rtx) | |
8237 | return; | |
8238 | ||
9ae8ffe7 | 8239 | if (code == STRICT_LOW_PART || code == ZERO_EXTRACT) |
bb4034b3 | 8240 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
9ae8ffe7 JL |
8241 | else if (code == REG || code == SUBREG || code == MEM) |
8242 | invalidate (dest, VOIDmode); | |
8b3686ed RK |
8243 | } |
8244 | ||
8245 | /* Invalidate all insns from START up to the end of the function or the | |
8246 | next label. This called when we wish to CSE around a block that is | |
8247 | conditionally executed. */ | |
8248 | ||
8249 | static void | |
8250 | invalidate_skipped_block (start) | |
8251 | rtx start; | |
8252 | { | |
8253 | rtx insn; | |
8b3686ed RK |
8254 | |
8255 | for (insn = start; insn && GET_CODE (insn) != CODE_LABEL; | |
8256 | insn = NEXT_INSN (insn)) | |
8257 | { | |
8258 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
8259 | continue; | |
8260 | ||
8b3686ed RK |
8261 | if (GET_CODE (insn) == CALL_INSN) |
8262 | { | |
9ae8ffe7 JL |
8263 | if (! CONST_CALL_P (insn)) |
8264 | invalidate_memory (); | |
8b3686ed | 8265 | invalidate_for_call (); |
8b3686ed RK |
8266 | } |
8267 | ||
97577254 | 8268 | invalidate_from_clobbers (PATTERN (insn)); |
8b3686ed | 8269 | note_stores (PATTERN (insn), invalidate_skipped_set); |
8b3686ed RK |
8270 | } |
8271 | } | |
8272 | \f | |
7afe21cc RK |
8273 | /* Used for communication between the following two routines; contains a |
8274 | value to be checked for modification. */ | |
8275 | ||
8276 | static rtx cse_check_loop_start_value; | |
8277 | ||
8278 | /* If modifying X will modify the value in CSE_CHECK_LOOP_START_VALUE, | |
8279 | indicate that fact by setting CSE_CHECK_LOOP_START_VALUE to 0. */ | |
8280 | ||
8281 | static void | |
8282 | cse_check_loop_start (x, set) | |
8283 | rtx x; | |
d6f4ec51 | 8284 | rtx set ATTRIBUTE_UNUSED; |
7afe21cc RK |
8285 | { |
8286 | if (cse_check_loop_start_value == 0 | |
8287 | || GET_CODE (x) == CC0 || GET_CODE (x) == PC) | |
8288 | return; | |
8289 | ||
8290 | if ((GET_CODE (x) == MEM && GET_CODE (cse_check_loop_start_value) == MEM) | |
8291 | || reg_overlap_mentioned_p (x, cse_check_loop_start_value)) | |
8292 | cse_check_loop_start_value = 0; | |
8293 | } | |
8294 | ||
8295 | /* X is a SET or CLOBBER contained in INSN that was found near the start of | |
8296 | a loop that starts with the label at LOOP_START. | |
8297 | ||
8298 | If X is a SET, we see if its SET_SRC is currently in our hash table. | |
8299 | If so, we see if it has a value equal to some register used only in the | |
8300 | loop exit code (as marked by jump.c). | |
8301 | ||
8302 | If those two conditions are true, we search backwards from the start of | |
8303 | the loop to see if that same value was loaded into a register that still | |
8304 | retains its value at the start of the loop. | |
8305 | ||
8306 | If so, we insert an insn after the load to copy the destination of that | |
8307 | load into the equivalent register and (try to) replace our SET_SRC with that | |
8308 | register. | |
8309 | ||
8310 | In any event, we invalidate whatever this SET or CLOBBER modifies. */ | |
8311 | ||
8312 | static void | |
8313 | cse_set_around_loop (x, insn, loop_start) | |
8314 | rtx x; | |
8315 | rtx insn; | |
8316 | rtx loop_start; | |
8317 | { | |
7afe21cc | 8318 | struct table_elt *src_elt; |
7afe21cc RK |
8319 | |
8320 | /* If this is a SET, see if we can replace SET_SRC, but ignore SETs that | |
8321 | are setting PC or CC0 or whose SET_SRC is already a register. */ | |
8322 | if (GET_CODE (x) == SET | |
8323 | && GET_CODE (SET_DEST (x)) != PC && GET_CODE (SET_DEST (x)) != CC0 | |
8324 | && GET_CODE (SET_SRC (x)) != REG) | |
8325 | { | |
8326 | src_elt = lookup (SET_SRC (x), | |
8327 | HASH (SET_SRC (x), GET_MODE (SET_DEST (x))), | |
8328 | GET_MODE (SET_DEST (x))); | |
8329 | ||
8330 | if (src_elt) | |
8331 | for (src_elt = src_elt->first_same_value; src_elt; | |
8332 | src_elt = src_elt->next_same_value) | |
8333 | if (GET_CODE (src_elt->exp) == REG && REG_LOOP_TEST_P (src_elt->exp) | |
8334 | && COST (src_elt->exp) < COST (SET_SRC (x))) | |
8335 | { | |
8336 | rtx p, set; | |
8337 | ||
8338 | /* Look for an insn in front of LOOP_START that sets | |
8339 | something in the desired mode to SET_SRC (x) before we hit | |
8340 | a label or CALL_INSN. */ | |
8341 | ||
8342 | for (p = prev_nonnote_insn (loop_start); | |
8343 | p && GET_CODE (p) != CALL_INSN | |
8344 | && GET_CODE (p) != CODE_LABEL; | |
8345 | p = prev_nonnote_insn (p)) | |
8346 | if ((set = single_set (p)) != 0 | |
8347 | && GET_CODE (SET_DEST (set)) == REG | |
8348 | && GET_MODE (SET_DEST (set)) == src_elt->mode | |
8349 | && rtx_equal_p (SET_SRC (set), SET_SRC (x))) | |
8350 | { | |
8351 | /* We now have to ensure that nothing between P | |
8352 | and LOOP_START modified anything referenced in | |
8353 | SET_SRC (x). We know that nothing within the loop | |
8354 | can modify it, or we would have invalidated it in | |
8355 | the hash table. */ | |
8356 | rtx q; | |
8357 | ||
8358 | cse_check_loop_start_value = SET_SRC (x); | |
8359 | for (q = p; q != loop_start; q = NEXT_INSN (q)) | |
8360 | if (GET_RTX_CLASS (GET_CODE (q)) == 'i') | |
8361 | note_stores (PATTERN (q), cse_check_loop_start); | |
8362 | ||
8363 | /* If nothing was changed and we can replace our | |
8364 | SET_SRC, add an insn after P to copy its destination | |
8365 | to what we will be replacing SET_SRC with. */ | |
8366 | if (cse_check_loop_start_value | |
8367 | && validate_change (insn, &SET_SRC (x), | |
8368 | src_elt->exp, 0)) | |
e89d3e6f R |
8369 | { |
8370 | /* If this creates new pseudos, this is unsafe, | |
8371 | because the regno of new pseudo is unsuitable | |
8372 | to index into reg_qty when cse_insn processes | |
8373 | the new insn. Therefore, if a new pseudo was | |
8374 | created, discard this optimization. */ | |
8375 | int nregs = max_reg_num (); | |
8376 | rtx move | |
8377 | = gen_move_insn (src_elt->exp, SET_DEST (set)); | |
8378 | if (nregs != max_reg_num ()) | |
8379 | { | |
8380 | if (! validate_change (insn, &SET_SRC (x), | |
8381 | SET_SRC (set), 0)) | |
8382 | abort (); | |
8383 | } | |
8384 | else | |
8385 | emit_insn_after (move, p); | |
8386 | } | |
7afe21cc RK |
8387 | break; |
8388 | } | |
8389 | } | |
8390 | } | |
8391 | ||
8392 | /* Now invalidate anything modified by X. */ | |
9ae8ffe7 | 8393 | note_mem_written (SET_DEST (x)); |
7afe21cc | 8394 | |
9ae8ffe7 | 8395 | /* See comment on similar code in cse_insn for explanation of these tests. */ |
7afe21cc | 8396 | if (GET_CODE (SET_DEST (x)) == REG || GET_CODE (SET_DEST (x)) == SUBREG |
9ae8ffe7 | 8397 | || GET_CODE (SET_DEST (x)) == MEM) |
bb4034b3 | 8398 | invalidate (SET_DEST (x), VOIDmode); |
2708da92 RS |
8399 | else if (GET_CODE (SET_DEST (x)) == STRICT_LOW_PART |
8400 | || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT) | |
bb4034b3 | 8401 | invalidate (XEXP (SET_DEST (x), 0), GET_MODE (SET_DEST (x))); |
7afe21cc RK |
8402 | } |
8403 | \f | |
8404 | /* Find the end of INSN's basic block and return its range, | |
8405 | the total number of SETs in all the insns of the block, the last insn of the | |
8406 | block, and the branch path. | |
8407 | ||
8408 | The branch path indicates which branches should be followed. If a non-zero | |
8409 | path size is specified, the block should be rescanned and a different set | |
8410 | of branches will be taken. The branch path is only used if | |
8b3686ed | 8411 | FLAG_CSE_FOLLOW_JUMPS or FLAG_CSE_SKIP_BLOCKS is non-zero. |
7afe21cc RK |
8412 | |
8413 | DATA is a pointer to a struct cse_basic_block_data, defined below, that is | |
8414 | used to describe the block. It is filled in with the information about | |
8415 | the current block. The incoming structure's branch path, if any, is used | |
8416 | to construct the output branch path. */ | |
8417 | ||
7afe21cc | 8418 | void |
8b3686ed | 8419 | cse_end_of_basic_block (insn, data, follow_jumps, after_loop, skip_blocks) |
7afe21cc RK |
8420 | rtx insn; |
8421 | struct cse_basic_block_data *data; | |
8422 | int follow_jumps; | |
8423 | int after_loop; | |
8b3686ed | 8424 | int skip_blocks; |
7afe21cc RK |
8425 | { |
8426 | rtx p = insn, q; | |
8427 | int nsets = 0; | |
8428 | int low_cuid = INSN_CUID (insn), high_cuid = INSN_CUID (insn); | |
fc3ffe83 | 8429 | rtx next = GET_RTX_CLASS (GET_CODE (insn)) == 'i' ? insn : next_real_insn (insn); |
7afe21cc RK |
8430 | int path_size = data->path_size; |
8431 | int path_entry = 0; | |
8432 | int i; | |
8433 | ||
8434 | /* Update the previous branch path, if any. If the last branch was | |
8435 | previously TAKEN, mark it NOT_TAKEN. If it was previously NOT_TAKEN, | |
8436 | shorten the path by one and look at the previous branch. We know that | |
8437 | at least one branch must have been taken if PATH_SIZE is non-zero. */ | |
8438 | while (path_size > 0) | |
8439 | { | |
8b3686ed | 8440 | if (data->path[path_size - 1].status != NOT_TAKEN) |
7afe21cc RK |
8441 | { |
8442 | data->path[path_size - 1].status = NOT_TAKEN; | |
8443 | break; | |
8444 | } | |
8445 | else | |
8446 | path_size--; | |
8447 | } | |
8448 | ||
8449 | /* Scan to end of this basic block. */ | |
8450 | while (p && GET_CODE (p) != CODE_LABEL) | |
8451 | { | |
8452 | /* Don't cse out the end of a loop. This makes a difference | |
8453 | only for the unusual loops that always execute at least once; | |
8454 | all other loops have labels there so we will stop in any case. | |
8455 | Cse'ing out the end of the loop is dangerous because it | |
8456 | might cause an invariant expression inside the loop | |
8457 | to be reused after the end of the loop. This would make it | |
8458 | hard to move the expression out of the loop in loop.c, | |
8459 | especially if it is one of several equivalent expressions | |
8460 | and loop.c would like to eliminate it. | |
8461 | ||
8462 | If we are running after loop.c has finished, we can ignore | |
8463 | the NOTE_INSN_LOOP_END. */ | |
8464 | ||
8465 | if (! after_loop && GET_CODE (p) == NOTE | |
8466 | && NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END) | |
8467 | break; | |
8468 | ||
8469 | /* Don't cse over a call to setjmp; on some machines (eg vax) | |
8470 | the regs restored by the longjmp come from | |
8471 | a later time than the setjmp. */ | |
8472 | if (GET_CODE (p) == NOTE | |
8473 | && NOTE_LINE_NUMBER (p) == NOTE_INSN_SETJMP) | |
8474 | break; | |
8475 | ||
8476 | /* A PARALLEL can have lots of SETs in it, | |
8477 | especially if it is really an ASM_OPERANDS. */ | |
8478 | if (GET_RTX_CLASS (GET_CODE (p)) == 'i' | |
8479 | && GET_CODE (PATTERN (p)) == PARALLEL) | |
8480 | nsets += XVECLEN (PATTERN (p), 0); | |
8481 | else if (GET_CODE (p) != NOTE) | |
8482 | nsets += 1; | |
8483 | ||
164c8956 RK |
8484 | /* Ignore insns made by CSE; they cannot affect the boundaries of |
8485 | the basic block. */ | |
8486 | ||
8487 | if (INSN_UID (p) <= max_uid && INSN_CUID (p) > high_cuid) | |
8b3686ed | 8488 | high_cuid = INSN_CUID (p); |
164c8956 RK |
8489 | if (INSN_UID (p) <= max_uid && INSN_CUID (p) < low_cuid) |
8490 | low_cuid = INSN_CUID (p); | |
7afe21cc RK |
8491 | |
8492 | /* See if this insn is in our branch path. If it is and we are to | |
8493 | take it, do so. */ | |
8494 | if (path_entry < path_size && data->path[path_entry].branch == p) | |
8495 | { | |
8b3686ed | 8496 | if (data->path[path_entry].status != NOT_TAKEN) |
7afe21cc RK |
8497 | p = JUMP_LABEL (p); |
8498 | ||
8499 | /* Point to next entry in path, if any. */ | |
8500 | path_entry++; | |
8501 | } | |
8502 | ||
8503 | /* If this is a conditional jump, we can follow it if -fcse-follow-jumps | |
8504 | was specified, we haven't reached our maximum path length, there are | |
8505 | insns following the target of the jump, this is the only use of the | |
8b3686ed RK |
8506 | jump label, and the target label is preceded by a BARRIER. |
8507 | ||
8508 | Alternatively, we can follow the jump if it branches around a | |
8509 | block of code and there are no other branches into the block. | |
8510 | In this case invalidate_skipped_block will be called to invalidate any | |
8511 | registers set in the block when following the jump. */ | |
8512 | ||
8513 | else if ((follow_jumps || skip_blocks) && path_size < PATHLENGTH - 1 | |
7afe21cc RK |
8514 | && GET_CODE (p) == JUMP_INSN |
8515 | && GET_CODE (PATTERN (p)) == SET | |
8516 | && GET_CODE (SET_SRC (PATTERN (p))) == IF_THEN_ELSE | |
85c3ba60 | 8517 | && JUMP_LABEL (p) != 0 |
7afe21cc RK |
8518 | && LABEL_NUSES (JUMP_LABEL (p)) == 1 |
8519 | && NEXT_INSN (JUMP_LABEL (p)) != 0) | |
8520 | { | |
8521 | for (q = PREV_INSN (JUMP_LABEL (p)); q; q = PREV_INSN (q)) | |
8522 | if ((GET_CODE (q) != NOTE | |
8523 | || NOTE_LINE_NUMBER (q) == NOTE_INSN_LOOP_END | |
8524 | || NOTE_LINE_NUMBER (q) == NOTE_INSN_SETJMP) | |
8525 | && (GET_CODE (q) != CODE_LABEL || LABEL_NUSES (q) != 0)) | |
8526 | break; | |
8527 | ||
8528 | /* If we ran into a BARRIER, this code is an extension of the | |
8529 | basic block when the branch is taken. */ | |
8b3686ed | 8530 | if (follow_jumps && q != 0 && GET_CODE (q) == BARRIER) |
7afe21cc RK |
8531 | { |
8532 | /* Don't allow ourself to keep walking around an | |
8533 | always-executed loop. */ | |
fc3ffe83 RK |
8534 | if (next_real_insn (q) == next) |
8535 | { | |
8536 | p = NEXT_INSN (p); | |
8537 | continue; | |
8538 | } | |
7afe21cc RK |
8539 | |
8540 | /* Similarly, don't put a branch in our path more than once. */ | |
8541 | for (i = 0; i < path_entry; i++) | |
8542 | if (data->path[i].branch == p) | |
8543 | break; | |
8544 | ||
8545 | if (i != path_entry) | |
8546 | break; | |
8547 | ||
8548 | data->path[path_entry].branch = p; | |
8549 | data->path[path_entry++].status = TAKEN; | |
8550 | ||
8551 | /* This branch now ends our path. It was possible that we | |
8552 | didn't see this branch the last time around (when the | |
8553 | insn in front of the target was a JUMP_INSN that was | |
8554 | turned into a no-op). */ | |
8555 | path_size = path_entry; | |
8556 | ||
8557 | p = JUMP_LABEL (p); | |
8558 | /* Mark block so we won't scan it again later. */ | |
8559 | PUT_MODE (NEXT_INSN (p), QImode); | |
8560 | } | |
8b3686ed RK |
8561 | /* Detect a branch around a block of code. */ |
8562 | else if (skip_blocks && q != 0 && GET_CODE (q) != CODE_LABEL) | |
8563 | { | |
8564 | register rtx tmp; | |
8565 | ||
fc3ffe83 RK |
8566 | if (next_real_insn (q) == next) |
8567 | { | |
8568 | p = NEXT_INSN (p); | |
8569 | continue; | |
8570 | } | |
8b3686ed RK |
8571 | |
8572 | for (i = 0; i < path_entry; i++) | |
8573 | if (data->path[i].branch == p) | |
8574 | break; | |
8575 | ||
8576 | if (i != path_entry) | |
8577 | break; | |
8578 | ||
8579 | /* This is no_labels_between_p (p, q) with an added check for | |
8580 | reaching the end of a function (in case Q precedes P). */ | |
8581 | for (tmp = NEXT_INSN (p); tmp && tmp != q; tmp = NEXT_INSN (tmp)) | |
8582 | if (GET_CODE (tmp) == CODE_LABEL) | |
8583 | break; | |
8584 | ||
8585 | if (tmp == q) | |
8586 | { | |
8587 | data->path[path_entry].branch = p; | |
8588 | data->path[path_entry++].status = AROUND; | |
8589 | ||
8590 | path_size = path_entry; | |
8591 | ||
8592 | p = JUMP_LABEL (p); | |
8593 | /* Mark block so we won't scan it again later. */ | |
8594 | PUT_MODE (NEXT_INSN (p), QImode); | |
8595 | } | |
8596 | } | |
7afe21cc | 8597 | } |
7afe21cc RK |
8598 | p = NEXT_INSN (p); |
8599 | } | |
8600 | ||
8601 | data->low_cuid = low_cuid; | |
8602 | data->high_cuid = high_cuid; | |
8603 | data->nsets = nsets; | |
8604 | data->last = p; | |
8605 | ||
8606 | /* If all jumps in the path are not taken, set our path length to zero | |
8607 | so a rescan won't be done. */ | |
8608 | for (i = path_size - 1; i >= 0; i--) | |
8b3686ed | 8609 | if (data->path[i].status != NOT_TAKEN) |
7afe21cc RK |
8610 | break; |
8611 | ||
8612 | if (i == -1) | |
8613 | data->path_size = 0; | |
8614 | else | |
8615 | data->path_size = path_size; | |
8616 | ||
8617 | /* End the current branch path. */ | |
8618 | data->path[path_size].branch = 0; | |
8619 | } | |
8620 | \f | |
7afe21cc RK |
8621 | /* Perform cse on the instructions of a function. |
8622 | F is the first instruction. | |
8623 | NREGS is one plus the highest pseudo-reg number used in the instruction. | |
8624 | ||
8625 | AFTER_LOOP is 1 if this is the cse call done after loop optimization | |
8626 | (only if -frerun-cse-after-loop). | |
8627 | ||
8628 | Returns 1 if jump_optimize should be redone due to simplifications | |
8629 | in conditional jump instructions. */ | |
8630 | ||
8631 | int | |
8632 | cse_main (f, nregs, after_loop, file) | |
8633 | rtx f; | |
8634 | int nregs; | |
8635 | int after_loop; | |
8636 | FILE *file; | |
8637 | { | |
8638 | struct cse_basic_block_data val; | |
8639 | register rtx insn = f; | |
8640 | register int i; | |
8641 | ||
8642 | cse_jumps_altered = 0; | |
a5dfb4ee | 8643 | recorded_label_ref = 0; |
7afe21cc RK |
8644 | constant_pool_entries_cost = 0; |
8645 | val.path_size = 0; | |
8646 | ||
8647 | init_recog (); | |
9ae8ffe7 | 8648 | init_alias_analysis (); |
7afe21cc RK |
8649 | |
8650 | max_reg = nregs; | |
8651 | ||
556c714b JW |
8652 | max_insn_uid = get_max_uid (); |
8653 | ||
7afe21cc RK |
8654 | reg_next_eqv = (int *) alloca (nregs * sizeof (int)); |
8655 | reg_prev_eqv = (int *) alloca (nregs * sizeof (int)); | |
7afe21cc | 8656 | |
7bac1be0 RK |
8657 | #ifdef LOAD_EXTEND_OP |
8658 | ||
8659 | /* Allocate scratch rtl here. cse_insn will fill in the memory reference | |
8660 | and change the code and mode as appropriate. */ | |
38a448ca | 8661 | memory_extend_rtx = gen_rtx_ZERO_EXTEND (VOIDmode, NULL_RTX); |
7bac1be0 RK |
8662 | #endif |
8663 | ||
7afe21cc RK |
8664 | /* Discard all the free elements of the previous function |
8665 | since they are allocated in the temporarily obstack. */ | |
4c9a05bc | 8666 | bzero ((char *) table, sizeof table); |
7afe21cc RK |
8667 | free_element_chain = 0; |
8668 | n_elements_made = 0; | |
8669 | ||
8670 | /* Find the largest uid. */ | |
8671 | ||
164c8956 RK |
8672 | max_uid = get_max_uid (); |
8673 | uid_cuid = (int *) alloca ((max_uid + 1) * sizeof (int)); | |
4c9a05bc | 8674 | bzero ((char *) uid_cuid, (max_uid + 1) * sizeof (int)); |
7afe21cc RK |
8675 | |
8676 | /* Compute the mapping from uids to cuids. | |
8677 | CUIDs are numbers assigned to insns, like uids, | |
8678 | except that cuids increase monotonically through the code. | |
8679 | Don't assign cuids to line-number NOTEs, so that the distance in cuids | |
8680 | between two insns is not affected by -g. */ | |
8681 | ||
8682 | for (insn = f, i = 0; insn; insn = NEXT_INSN (insn)) | |
8683 | { | |
8684 | if (GET_CODE (insn) != NOTE | |
8685 | || NOTE_LINE_NUMBER (insn) < 0) | |
8686 | INSN_CUID (insn) = ++i; | |
8687 | else | |
8688 | /* Give a line number note the same cuid as preceding insn. */ | |
8689 | INSN_CUID (insn) = i; | |
8690 | } | |
8691 | ||
8692 | /* Initialize which registers are clobbered by calls. */ | |
8693 | ||
8694 | CLEAR_HARD_REG_SET (regs_invalidated_by_call); | |
8695 | ||
8696 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
8697 | if ((call_used_regs[i] | |
8698 | /* Used to check !fixed_regs[i] here, but that isn't safe; | |
8699 | fixed regs are still call-clobbered, and sched can get | |
8700 | confused if they can "live across calls". | |
8701 | ||
8702 | The frame pointer is always preserved across calls. The arg | |
8703 | pointer is if it is fixed. The stack pointer usually is, unless | |
8704 | RETURN_POPS_ARGS, in which case an explicit CLOBBER | |
8705 | will be present. If we are generating PIC code, the PIC offset | |
8706 | table register is preserved across calls. */ | |
8707 | ||
8708 | && i != STACK_POINTER_REGNUM | |
8709 | && i != FRAME_POINTER_REGNUM | |
8bc169f2 DE |
8710 | #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM |
8711 | && i != HARD_FRAME_POINTER_REGNUM | |
8712 | #endif | |
7afe21cc RK |
8713 | #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM |
8714 | && ! (i == ARG_POINTER_REGNUM && fixed_regs[i]) | |
8715 | #endif | |
be8fe470 | 8716 | #if defined (PIC_OFFSET_TABLE_REGNUM) && !defined (PIC_OFFSET_TABLE_REG_CALL_CLOBBERED) |
7afe21cc RK |
8717 | && ! (i == PIC_OFFSET_TABLE_REGNUM && flag_pic) |
8718 | #endif | |
8719 | ) | |
8720 | || global_regs[i]) | |
8721 | SET_HARD_REG_BIT (regs_invalidated_by_call, i); | |
8722 | ||
8723 | /* Loop over basic blocks. | |
8724 | Compute the maximum number of qty's needed for each basic block | |
8725 | (which is 2 for each SET). */ | |
8726 | insn = f; | |
8727 | while (insn) | |
8728 | { | |
8b3686ed RK |
8729 | cse_end_of_basic_block (insn, &val, flag_cse_follow_jumps, after_loop, |
8730 | flag_cse_skip_blocks); | |
7afe21cc RK |
8731 | |
8732 | /* If this basic block was already processed or has no sets, skip it. */ | |
8733 | if (val.nsets == 0 || GET_MODE (insn) == QImode) | |
8734 | { | |
8735 | PUT_MODE (insn, VOIDmode); | |
8736 | insn = (val.last ? NEXT_INSN (val.last) : 0); | |
8737 | val.path_size = 0; | |
8738 | continue; | |
8739 | } | |
8740 | ||
8741 | cse_basic_block_start = val.low_cuid; | |
8742 | cse_basic_block_end = val.high_cuid; | |
8743 | max_qty = val.nsets * 2; | |
8744 | ||
8745 | if (file) | |
ab87f8c8 | 8746 | fnotice (file, ";; Processing block from %d to %d, %d sets.\n", |
7afe21cc RK |
8747 | INSN_UID (insn), val.last ? INSN_UID (val.last) : 0, |
8748 | val.nsets); | |
8749 | ||
8750 | /* Make MAX_QTY bigger to give us room to optimize | |
8751 | past the end of this basic block, if that should prove useful. */ | |
8752 | if (max_qty < 500) | |
8753 | max_qty = 500; | |
8754 | ||
8755 | max_qty += max_reg; | |
8756 | ||
8757 | /* If this basic block is being extended by following certain jumps, | |
8758 | (see `cse_end_of_basic_block'), we reprocess the code from the start. | |
8759 | Otherwise, we start after this basic block. */ | |
8760 | if (val.path_size > 0) | |
8761 | cse_basic_block (insn, val.last, val.path, 0); | |
8762 | else | |
8763 | { | |
8764 | int old_cse_jumps_altered = cse_jumps_altered; | |
8765 | rtx temp; | |
8766 | ||
8767 | /* When cse changes a conditional jump to an unconditional | |
8768 | jump, we want to reprocess the block, since it will give | |
8769 | us a new branch path to investigate. */ | |
8770 | cse_jumps_altered = 0; | |
8771 | temp = cse_basic_block (insn, val.last, val.path, ! after_loop); | |
8b3686ed RK |
8772 | if (cse_jumps_altered == 0 |
8773 | || (flag_cse_follow_jumps == 0 && flag_cse_skip_blocks == 0)) | |
7afe21cc RK |
8774 | insn = temp; |
8775 | ||
8776 | cse_jumps_altered |= old_cse_jumps_altered; | |
8777 | } | |
8778 | ||
8779 | #ifdef USE_C_ALLOCA | |
8780 | alloca (0); | |
8781 | #endif | |
8782 | } | |
8783 | ||
8784 | /* Tell refers_to_mem_p that qty_const info is not available. */ | |
8785 | qty_const = 0; | |
8786 | ||
8787 | if (max_elements_made < n_elements_made) | |
8788 | max_elements_made = n_elements_made; | |
8789 | ||
a5dfb4ee | 8790 | return cse_jumps_altered || recorded_label_ref; |
7afe21cc RK |
8791 | } |
8792 | ||
8793 | /* Process a single basic block. FROM and TO and the limits of the basic | |
8794 | block. NEXT_BRANCH points to the branch path when following jumps or | |
8795 | a null path when not following jumps. | |
8796 | ||
8797 | AROUND_LOOP is non-zero if we are to try to cse around to the start of a | |
8798 | loop. This is true when we are being called for the last time on a | |
8799 | block and this CSE pass is before loop.c. */ | |
8800 | ||
8801 | static rtx | |
8802 | cse_basic_block (from, to, next_branch, around_loop) | |
8803 | register rtx from, to; | |
8804 | struct branch_path *next_branch; | |
8805 | int around_loop; | |
8806 | { | |
8807 | register rtx insn; | |
8808 | int to_usage = 0; | |
7bd8b2a8 | 8809 | rtx libcall_insn = NULL_RTX; |
e9a25f70 | 8810 | int num_insns = 0; |
7afe21cc RK |
8811 | |
8812 | /* Each of these arrays is undefined before max_reg, so only allocate | |
8813 | the space actually needed and adjust the start below. */ | |
8814 | ||
8815 | qty_first_reg = (int *) alloca ((max_qty - max_reg) * sizeof (int)); | |
8816 | qty_last_reg = (int *) alloca ((max_qty - max_reg) * sizeof (int)); | |
8817 | qty_mode= (enum machine_mode *) alloca ((max_qty - max_reg) * sizeof (enum machine_mode)); | |
8818 | qty_const = (rtx *) alloca ((max_qty - max_reg) * sizeof (rtx)); | |
8819 | qty_const_insn = (rtx *) alloca ((max_qty - max_reg) * sizeof (rtx)); | |
8820 | qty_comparison_code | |
8821 | = (enum rtx_code *) alloca ((max_qty - max_reg) * sizeof (enum rtx_code)); | |
8822 | qty_comparison_qty = (int *) alloca ((max_qty - max_reg) * sizeof (int)); | |
8823 | qty_comparison_const = (rtx *) alloca ((max_qty - max_reg) * sizeof (rtx)); | |
8824 | ||
8825 | qty_first_reg -= max_reg; | |
8826 | qty_last_reg -= max_reg; | |
8827 | qty_mode -= max_reg; | |
8828 | qty_const -= max_reg; | |
8829 | qty_const_insn -= max_reg; | |
8830 | qty_comparison_code -= max_reg; | |
8831 | qty_comparison_qty -= max_reg; | |
8832 | qty_comparison_const -= max_reg; | |
8833 | ||
8834 | new_basic_block (); | |
8835 | ||
8836 | /* TO might be a label. If so, protect it from being deleted. */ | |
8837 | if (to != 0 && GET_CODE (to) == CODE_LABEL) | |
8838 | ++LABEL_NUSES (to); | |
8839 | ||
8840 | for (insn = from; insn != to; insn = NEXT_INSN (insn)) | |
8841 | { | |
1d22a2c1 | 8842 | register enum rtx_code code = GET_CODE (insn); |
e9a25f70 | 8843 | |
1d22a2c1 MM |
8844 | /* If we have processed 1,000 insns, flush the hash table to |
8845 | avoid extreme quadratic behavior. We must not include NOTEs | |
8846 | in the count since there may be more or them when generating | |
8847 | debugging information. If we clear the table at different | |
8848 | times, code generated with -g -O might be different than code | |
8849 | generated with -O but not -g. | |
e9a25f70 JL |
8850 | |
8851 | ??? This is a real kludge and needs to be done some other way. | |
8852 | Perhaps for 2.9. */ | |
1d22a2c1 | 8853 | if (code != NOTE && num_insns++ > 1000) |
e9a25f70 | 8854 | { |
01e752d3 | 8855 | flush_hash_table (); |
e9a25f70 JL |
8856 | num_insns = 0; |
8857 | } | |
7afe21cc RK |
8858 | |
8859 | /* See if this is a branch that is part of the path. If so, and it is | |
8860 | to be taken, do so. */ | |
8861 | if (next_branch->branch == insn) | |
8862 | { | |
8b3686ed RK |
8863 | enum taken status = next_branch++->status; |
8864 | if (status != NOT_TAKEN) | |
7afe21cc | 8865 | { |
8b3686ed RK |
8866 | if (status == TAKEN) |
8867 | record_jump_equiv (insn, 1); | |
8868 | else | |
8869 | invalidate_skipped_block (NEXT_INSN (insn)); | |
8870 | ||
7afe21cc RK |
8871 | /* Set the last insn as the jump insn; it doesn't affect cc0. |
8872 | Then follow this branch. */ | |
8873 | #ifdef HAVE_cc0 | |
8874 | prev_insn_cc0 = 0; | |
8875 | #endif | |
8876 | prev_insn = insn; | |
8877 | insn = JUMP_LABEL (insn); | |
8878 | continue; | |
8879 | } | |
8880 | } | |
8881 | ||
7afe21cc RK |
8882 | if (GET_MODE (insn) == QImode) |
8883 | PUT_MODE (insn, VOIDmode); | |
8884 | ||
8885 | if (GET_RTX_CLASS (code) == 'i') | |
8886 | { | |
7bd8b2a8 JL |
8887 | rtx p; |
8888 | ||
7afe21cc RK |
8889 | /* Process notes first so we have all notes in canonical forms when |
8890 | looking for duplicate operations. */ | |
8891 | ||
8892 | if (REG_NOTES (insn)) | |
906c4e36 | 8893 | REG_NOTES (insn) = cse_process_notes (REG_NOTES (insn), NULL_RTX); |
7afe21cc RK |
8894 | |
8895 | /* Track when we are inside in LIBCALL block. Inside such a block, | |
8896 | we do not want to record destinations. The last insn of a | |
8897 | LIBCALL block is not considered to be part of the block, since | |
830a38ee | 8898 | its destination is the result of the block and hence should be |
7afe21cc RK |
8899 | recorded. */ |
8900 | ||
63be02db | 8901 | if ((p = find_reg_note (insn, REG_LIBCALL, NULL_RTX))) |
7bd8b2a8 | 8902 | libcall_insn = XEXP (p, 0); |
906c4e36 | 8903 | else if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
7bd8b2a8 | 8904 | libcall_insn = NULL_RTX; |
7afe21cc | 8905 | |
7bd8b2a8 | 8906 | cse_insn (insn, libcall_insn); |
7afe21cc RK |
8907 | } |
8908 | ||
8909 | /* If INSN is now an unconditional jump, skip to the end of our | |
8910 | basic block by pretending that we just did the last insn in the | |
8911 | basic block. If we are jumping to the end of our block, show | |
8912 | that we can have one usage of TO. */ | |
8913 | ||
8914 | if (simplejump_p (insn)) | |
8915 | { | |
8916 | if (to == 0) | |
8917 | return 0; | |
8918 | ||
8919 | if (JUMP_LABEL (insn) == to) | |
8920 | to_usage = 1; | |
8921 | ||
6a5293dc RS |
8922 | /* Maybe TO was deleted because the jump is unconditional. |
8923 | If so, there is nothing left in this basic block. */ | |
8924 | /* ??? Perhaps it would be smarter to set TO | |
8925 | to whatever follows this insn, | |
8926 | and pretend the basic block had always ended here. */ | |
8927 | if (INSN_DELETED_P (to)) | |
8928 | break; | |
8929 | ||
7afe21cc RK |
8930 | insn = PREV_INSN (to); |
8931 | } | |
8932 | ||
8933 | /* See if it is ok to keep on going past the label | |
8934 | which used to end our basic block. Remember that we incremented | |
d45cf215 | 8935 | the count of that label, so we decrement it here. If we made |
7afe21cc RK |
8936 | a jump unconditional, TO_USAGE will be one; in that case, we don't |
8937 | want to count the use in that jump. */ | |
8938 | ||
8939 | if (to != 0 && NEXT_INSN (insn) == to | |
8940 | && GET_CODE (to) == CODE_LABEL && --LABEL_NUSES (to) == to_usage) | |
8941 | { | |
8942 | struct cse_basic_block_data val; | |
146135d6 | 8943 | rtx prev; |
7afe21cc RK |
8944 | |
8945 | insn = NEXT_INSN (to); | |
8946 | ||
8947 | if (LABEL_NUSES (to) == 0) | |
146135d6 | 8948 | insn = delete_insn (to); |
7afe21cc | 8949 | |
146135d6 RK |
8950 | /* If TO was the last insn in the function, we are done. */ |
8951 | if (insn == 0) | |
7afe21cc RK |
8952 | return 0; |
8953 | ||
146135d6 RK |
8954 | /* If TO was preceded by a BARRIER we are done with this block |
8955 | because it has no continuation. */ | |
8956 | prev = prev_nonnote_insn (to); | |
8957 | if (prev && GET_CODE (prev) == BARRIER) | |
8958 | return insn; | |
8959 | ||
8960 | /* Find the end of the following block. Note that we won't be | |
8961 | following branches in this case. */ | |
7afe21cc RK |
8962 | to_usage = 0; |
8963 | val.path_size = 0; | |
8b3686ed | 8964 | cse_end_of_basic_block (insn, &val, 0, 0, 0); |
7afe21cc RK |
8965 | |
8966 | /* If the tables we allocated have enough space left | |
8967 | to handle all the SETs in the next basic block, | |
8968 | continue through it. Otherwise, return, | |
8969 | and that block will be scanned individually. */ | |
8970 | if (val.nsets * 2 + next_qty > max_qty) | |
8971 | break; | |
8972 | ||
8973 | cse_basic_block_start = val.low_cuid; | |
8974 | cse_basic_block_end = val.high_cuid; | |
8975 | to = val.last; | |
8976 | ||
8977 | /* Prevent TO from being deleted if it is a label. */ | |
8978 | if (to != 0 && GET_CODE (to) == CODE_LABEL) | |
8979 | ++LABEL_NUSES (to); | |
8980 | ||
8981 | /* Back up so we process the first insn in the extension. */ | |
8982 | insn = PREV_INSN (insn); | |
8983 | } | |
8984 | } | |
8985 | ||
8986 | if (next_qty > max_qty) | |
8987 | abort (); | |
8988 | ||
8989 | /* If we are running before loop.c, we stopped on a NOTE_INSN_LOOP_END, and | |
8990 | the previous insn is the only insn that branches to the head of a loop, | |
8991 | we can cse into the loop. Don't do this if we changed the jump | |
8992 | structure of a loop unless we aren't going to be following jumps. */ | |
8993 | ||
8b3686ed RK |
8994 | if ((cse_jumps_altered == 0 |
8995 | || (flag_cse_follow_jumps == 0 && flag_cse_skip_blocks == 0)) | |
7afe21cc RK |
8996 | && around_loop && to != 0 |
8997 | && GET_CODE (to) == NOTE && NOTE_LINE_NUMBER (to) == NOTE_INSN_LOOP_END | |
8998 | && GET_CODE (PREV_INSN (to)) == JUMP_INSN | |
8999 | && JUMP_LABEL (PREV_INSN (to)) != 0 | |
9000 | && LABEL_NUSES (JUMP_LABEL (PREV_INSN (to))) == 1) | |
9001 | cse_around_loop (JUMP_LABEL (PREV_INSN (to))); | |
9002 | ||
9003 | return to ? NEXT_INSN (to) : 0; | |
9004 | } | |
9005 | \f | |
9006 | /* Count the number of times registers are used (not set) in X. | |
9007 | COUNTS is an array in which we accumulate the count, INCR is how much | |
79644f06 RK |
9008 | we count each register usage. |
9009 | ||
9010 | Don't count a usage of DEST, which is the SET_DEST of a SET which | |
9011 | contains X in its SET_SRC. This is because such a SET does not | |
9012 | modify the liveness of DEST. */ | |
7afe21cc RK |
9013 | |
9014 | static void | |
79644f06 | 9015 | count_reg_usage (x, counts, dest, incr) |
7afe21cc RK |
9016 | rtx x; |
9017 | int *counts; | |
79644f06 | 9018 | rtx dest; |
7afe21cc RK |
9019 | int incr; |
9020 | { | |
f1e7c95f | 9021 | enum rtx_code code; |
7afe21cc RK |
9022 | char *fmt; |
9023 | int i, j; | |
9024 | ||
f1e7c95f RK |
9025 | if (x == 0) |
9026 | return; | |
9027 | ||
9028 | switch (code = GET_CODE (x)) | |
7afe21cc RK |
9029 | { |
9030 | case REG: | |
79644f06 RK |
9031 | if (x != dest) |
9032 | counts[REGNO (x)] += incr; | |
7afe21cc RK |
9033 | return; |
9034 | ||
9035 | case PC: | |
9036 | case CC0: | |
9037 | case CONST: | |
9038 | case CONST_INT: | |
9039 | case CONST_DOUBLE: | |
9040 | case SYMBOL_REF: | |
9041 | case LABEL_REF: | |
02e39abc JL |
9042 | return; |
9043 | ||
9044 | case CLOBBER: | |
9045 | /* If we are clobbering a MEM, mark any registers inside the address | |
9046 | as being used. */ | |
9047 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
9048 | count_reg_usage (XEXP (XEXP (x, 0), 0), counts, NULL_RTX, incr); | |
7afe21cc RK |
9049 | return; |
9050 | ||
9051 | case SET: | |
9052 | /* Unless we are setting a REG, count everything in SET_DEST. */ | |
9053 | if (GET_CODE (SET_DEST (x)) != REG) | |
79644f06 | 9054 | count_reg_usage (SET_DEST (x), counts, NULL_RTX, incr); |
9ff08f70 RK |
9055 | |
9056 | /* If SRC has side-effects, then we can't delete this insn, so the | |
9057 | usage of SET_DEST inside SRC counts. | |
9058 | ||
9059 | ??? Strictly-speaking, we might be preserving this insn | |
9060 | because some other SET has side-effects, but that's hard | |
9061 | to do and can't happen now. */ | |
9062 | count_reg_usage (SET_SRC (x), counts, | |
9063 | side_effects_p (SET_SRC (x)) ? NULL_RTX : SET_DEST (x), | |
9064 | incr); | |
7afe21cc RK |
9065 | return; |
9066 | ||
f1e7c95f RK |
9067 | case CALL_INSN: |
9068 | count_reg_usage (CALL_INSN_FUNCTION_USAGE (x), counts, NULL_RTX, incr); | |
9069 | ||
9070 | /* ... falls through ... */ | |
7afe21cc RK |
9071 | case INSN: |
9072 | case JUMP_INSN: | |
79644f06 | 9073 | count_reg_usage (PATTERN (x), counts, NULL_RTX, incr); |
7afe21cc RK |
9074 | |
9075 | /* Things used in a REG_EQUAL note aren't dead since loop may try to | |
9076 | use them. */ | |
9077 | ||
f1e7c95f | 9078 | count_reg_usage (REG_NOTES (x), counts, NULL_RTX, incr); |
7afe21cc RK |
9079 | return; |
9080 | ||
9081 | case EXPR_LIST: | |
9082 | case INSN_LIST: | |
f1e7c95f | 9083 | if (REG_NOTE_KIND (x) == REG_EQUAL |
c6a26dc4 | 9084 | || (REG_NOTE_KIND (x) != REG_NONNEG && GET_CODE (XEXP (x,0)) == USE)) |
79644f06 | 9085 | count_reg_usage (XEXP (x, 0), counts, NULL_RTX, incr); |
f1e7c95f | 9086 | count_reg_usage (XEXP (x, 1), counts, NULL_RTX, incr); |
7afe21cc | 9087 | return; |
e9a25f70 JL |
9088 | |
9089 | default: | |
9090 | break; | |
7afe21cc RK |
9091 | } |
9092 | ||
9093 | fmt = GET_RTX_FORMAT (code); | |
9094 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
9095 | { | |
9096 | if (fmt[i] == 'e') | |
79644f06 | 9097 | count_reg_usage (XEXP (x, i), counts, dest, incr); |
7afe21cc RK |
9098 | else if (fmt[i] == 'E') |
9099 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
79644f06 | 9100 | count_reg_usage (XVECEXP (x, i, j), counts, dest, incr); |
7afe21cc RK |
9101 | } |
9102 | } | |
9103 | \f | |
9104 | /* Scan all the insns and delete any that are dead; i.e., they store a register | |
9105 | that is never used or they copy a register to itself. | |
9106 | ||
c6a26dc4 JL |
9107 | This is used to remove insns made obviously dead by cse, loop or other |
9108 | optimizations. It improves the heuristics in loop since it won't try to | |
9109 | move dead invariants out of loops or make givs for dead quantities. The | |
9110 | remaining passes of the compilation are also sped up. */ | |
7afe21cc RK |
9111 | |
9112 | void | |
c6a26dc4 | 9113 | delete_trivially_dead_insns (insns, nreg) |
7afe21cc RK |
9114 | rtx insns; |
9115 | int nreg; | |
9116 | { | |
9117 | int *counts = (int *) alloca (nreg * sizeof (int)); | |
77fa0940 | 9118 | rtx insn, prev; |
51723711 | 9119 | #ifdef HAVE_cc0 |
d45cf215 | 9120 | rtx tem; |
51723711 | 9121 | #endif |
7afe21cc | 9122 | int i; |
614bb5d4 | 9123 | int in_libcall = 0, dead_libcall = 0; |
7afe21cc RK |
9124 | |
9125 | /* First count the number of times each register is used. */ | |
4c9a05bc | 9126 | bzero ((char *) counts, sizeof (int) * nreg); |
7afe21cc | 9127 | for (insn = next_real_insn (insns); insn; insn = next_real_insn (insn)) |
79644f06 | 9128 | count_reg_usage (insn, counts, NULL_RTX, 1); |
7afe21cc RK |
9129 | |
9130 | /* Go from the last insn to the first and delete insns that only set unused | |
9131 | registers or copy a register to itself. As we delete an insn, remove | |
9132 | usage counts for registers it uses. */ | |
77fa0940 | 9133 | for (insn = prev_real_insn (get_last_insn ()); insn; insn = prev) |
7afe21cc RK |
9134 | { |
9135 | int live_insn = 0; | |
614bb5d4 | 9136 | rtx note; |
7afe21cc | 9137 | |
77fa0940 RK |
9138 | prev = prev_real_insn (insn); |
9139 | ||
614bb5d4 JL |
9140 | /* Don't delete any insns that are part of a libcall block unless |
9141 | we can delete the whole libcall block. | |
9142 | ||
77fa0940 RK |
9143 | Flow or loop might get confused if we did that. Remember |
9144 | that we are scanning backwards. */ | |
906c4e36 | 9145 | if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
614bb5d4 JL |
9146 | { |
9147 | in_libcall = 1; | |
9148 | live_insn = 1; | |
9149 | dead_libcall = 0; | |
e4890d45 | 9150 | |
614bb5d4 JL |
9151 | /* See if there's a REG_EQUAL note on this insn and try to |
9152 | replace the source with the REG_EQUAL expression. | |
9153 | ||
9154 | We assume that insns with REG_RETVALs can only be reg->reg | |
9155 | copies at this point. */ | |
9156 | note = find_reg_note (insn, REG_EQUAL, NULL_RTX); | |
9157 | if (note) | |
9158 | { | |
9159 | rtx set = single_set (insn); | |
9160 | if (set | |
9161 | && validate_change (insn, &SET_SRC (set), XEXP (note, 0), 0)) | |
9162 | { | |
9163 | remove_note (insn, | |
9164 | find_reg_note (insn, REG_RETVAL, NULL_RTX)); | |
9165 | dead_libcall = 1; | |
9166 | } | |
9167 | } | |
9168 | } | |
9169 | else if (in_libcall) | |
9170 | live_insn = ! dead_libcall; | |
e4890d45 | 9171 | else if (GET_CODE (PATTERN (insn)) == SET) |
7afe21cc RK |
9172 | { |
9173 | if (GET_CODE (SET_DEST (PATTERN (insn))) == REG | |
9174 | && SET_DEST (PATTERN (insn)) == SET_SRC (PATTERN (insn))) | |
9175 | ; | |
9176 | ||
d45cf215 RS |
9177 | #ifdef HAVE_cc0 |
9178 | else if (GET_CODE (SET_DEST (PATTERN (insn))) == CC0 | |
9179 | && ! side_effects_p (SET_SRC (PATTERN (insn))) | |
9180 | && ((tem = next_nonnote_insn (insn)) == 0 | |
9181 | || GET_RTX_CLASS (GET_CODE (tem)) != 'i' | |
9182 | || ! reg_referenced_p (cc0_rtx, PATTERN (tem)))) | |
9183 | ; | |
9184 | #endif | |
7afe21cc RK |
9185 | else if (GET_CODE (SET_DEST (PATTERN (insn))) != REG |
9186 | || REGNO (SET_DEST (PATTERN (insn))) < FIRST_PSEUDO_REGISTER | |
9187 | || counts[REGNO (SET_DEST (PATTERN (insn)))] != 0 | |
9188 | || side_effects_p (SET_SRC (PATTERN (insn)))) | |
9189 | live_insn = 1; | |
9190 | } | |
9191 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
9192 | for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) | |
9193 | { | |
9194 | rtx elt = XVECEXP (PATTERN (insn), 0, i); | |
9195 | ||
9196 | if (GET_CODE (elt) == SET) | |
9197 | { | |
9198 | if (GET_CODE (SET_DEST (elt)) == REG | |
9199 | && SET_DEST (elt) == SET_SRC (elt)) | |
9200 | ; | |
9201 | ||
d45cf215 RS |
9202 | #ifdef HAVE_cc0 |
9203 | else if (GET_CODE (SET_DEST (elt)) == CC0 | |
9204 | && ! side_effects_p (SET_SRC (elt)) | |
9205 | && ((tem = next_nonnote_insn (insn)) == 0 | |
9206 | || GET_RTX_CLASS (GET_CODE (tem)) != 'i' | |
9207 | || ! reg_referenced_p (cc0_rtx, PATTERN (tem)))) | |
9208 | ; | |
9209 | #endif | |
7afe21cc RK |
9210 | else if (GET_CODE (SET_DEST (elt)) != REG |
9211 | || REGNO (SET_DEST (elt)) < FIRST_PSEUDO_REGISTER | |
9212 | || counts[REGNO (SET_DEST (elt))] != 0 | |
9213 | || side_effects_p (SET_SRC (elt))) | |
9214 | live_insn = 1; | |
9215 | } | |
9216 | else if (GET_CODE (elt) != CLOBBER && GET_CODE (elt) != USE) | |
9217 | live_insn = 1; | |
9218 | } | |
9219 | else | |
9220 | live_insn = 1; | |
9221 | ||
9222 | /* If this is a dead insn, delete it and show registers in it aren't | |
e4890d45 | 9223 | being used. */ |
7afe21cc | 9224 | |
e4890d45 | 9225 | if (! live_insn) |
7afe21cc | 9226 | { |
79644f06 | 9227 | count_reg_usage (insn, counts, NULL_RTX, -1); |
77fa0940 | 9228 | delete_insn (insn); |
7afe21cc | 9229 | } |
e4890d45 | 9230 | |
906c4e36 | 9231 | if (find_reg_note (insn, REG_LIBCALL, NULL_RTX)) |
614bb5d4 JL |
9232 | { |
9233 | in_libcall = 0; | |
9234 | dead_libcall = 0; | |
9235 | } | |
7afe21cc RK |
9236 | } |
9237 | } |