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7afe21cc | 1 | /* Common subexpression elimination for GNU compiler. |
5e7b4e25 | 2 | Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998 |
7e7e28c7 AO |
3 | 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
4 | Free Software Foundation, Inc. | |
7afe21cc | 5 | |
1322177d | 6 | This file is part of GCC. |
7afe21cc | 7 | |
1322177d LB |
8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 2, or (at your option) any later | |
11 | version. | |
7afe21cc | 12 | |
1322177d LB |
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
7afe21cc RK |
17 | |
18 | You should have received a copy of the GNU General Public License | |
1322177d | 19 | along with GCC; see the file COPYING. If not, write to the Free |
366ccddb KC |
20 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
21 | 02110-1301, USA. */ | |
7afe21cc | 22 | |
7afe21cc | 23 | #include "config.h" |
670ee920 KG |
24 | /* stdio.h must precede rtl.h for FFS. */ |
25 | #include "system.h" | |
4977bab6 ZW |
26 | #include "coretypes.h" |
27 | #include "tm.h" | |
7afe21cc | 28 | #include "rtl.h" |
6baf1cc8 | 29 | #include "tm_p.h" |
7afe21cc | 30 | #include "hard-reg-set.h" |
7932a3db | 31 | #include "regs.h" |
630c79be | 32 | #include "basic-block.h" |
7afe21cc RK |
33 | #include "flags.h" |
34 | #include "real.h" | |
35 | #include "insn-config.h" | |
36 | #include "recog.h" | |
49ad7cfa | 37 | #include "function.h" |
956d6950 | 38 | #include "expr.h" |
50b2596f KG |
39 | #include "toplev.h" |
40 | #include "output.h" | |
1497faf6 | 41 | #include "ggc.h" |
3dec4024 | 42 | #include "timevar.h" |
26771da7 | 43 | #include "except.h" |
3c50106f | 44 | #include "target.h" |
9bf8cfbf | 45 | #include "params.h" |
2f93eea8 | 46 | #include "rtlhooks-def.h" |
ef330312 | 47 | #include "tree-pass.h" |
7afe21cc RK |
48 | |
49 | /* The basic idea of common subexpression elimination is to go | |
50 | through the code, keeping a record of expressions that would | |
51 | have the same value at the current scan point, and replacing | |
52 | expressions encountered with the cheapest equivalent expression. | |
53 | ||
54 | It is too complicated to keep track of the different possibilities | |
e48a7fbe JL |
55 | when control paths merge in this code; so, at each label, we forget all |
56 | that is known and start fresh. This can be described as processing each | |
57 | extended basic block separately. We have a separate pass to perform | |
58 | global CSE. | |
59 | ||
60 | Note CSE can turn a conditional or computed jump into a nop or | |
61 | an unconditional jump. When this occurs we arrange to run the jump | |
62 | optimizer after CSE to delete the unreachable code. | |
7afe21cc RK |
63 | |
64 | We use two data structures to record the equivalent expressions: | |
1bb98cec DM |
65 | a hash table for most expressions, and a vector of "quantity |
66 | numbers" to record equivalent (pseudo) registers. | |
7afe21cc RK |
67 | |
68 | The use of the special data structure for registers is desirable | |
69 | because it is faster. It is possible because registers references | |
70 | contain a fairly small number, the register number, taken from | |
71 | a contiguously allocated series, and two register references are | |
72 | identical if they have the same number. General expressions | |
73 | do not have any such thing, so the only way to retrieve the | |
74 | information recorded on an expression other than a register | |
75 | is to keep it in a hash table. | |
76 | ||
77 | Registers and "quantity numbers": | |
278a83b2 | 78 | |
7afe21cc RK |
79 | At the start of each basic block, all of the (hardware and pseudo) |
80 | registers used in the function are given distinct quantity | |
81 | numbers to indicate their contents. During scan, when the code | |
82 | copies one register into another, we copy the quantity number. | |
83 | When a register is loaded in any other way, we allocate a new | |
84 | quantity number to describe the value generated by this operation. | |
459281be | 85 | `REG_QTY (N)' records what quantity register N is currently thought |
7afe21cc RK |
86 | of as containing. |
87 | ||
08a69267 | 88 | All real quantity numbers are greater than or equal to zero. |
459281be | 89 | If register N has not been assigned a quantity, `REG_QTY (N)' will |
08a69267 | 90 | equal -N - 1, which is always negative. |
7afe21cc | 91 | |
08a69267 RS |
92 | Quantity numbers below zero do not exist and none of the `qty_table' |
93 | entries should be referenced with a negative index. | |
7afe21cc RK |
94 | |
95 | We also maintain a bidirectional chain of registers for each | |
1bb98cec DM |
96 | quantity number. The `qty_table` members `first_reg' and `last_reg', |
97 | and `reg_eqv_table' members `next' and `prev' hold these chains. | |
7afe21cc RK |
98 | |
99 | The first register in a chain is the one whose lifespan is least local. | |
100 | Among equals, it is the one that was seen first. | |
101 | We replace any equivalent register with that one. | |
102 | ||
103 | If two registers have the same quantity number, it must be true that | |
1bb98cec | 104 | REG expressions with qty_table `mode' must be in the hash table for both |
7afe21cc RK |
105 | registers and must be in the same class. |
106 | ||
107 | The converse is not true. Since hard registers may be referenced in | |
108 | any mode, two REG expressions might be equivalent in the hash table | |
109 | but not have the same quantity number if the quantity number of one | |
110 | of the registers is not the same mode as those expressions. | |
278a83b2 | 111 | |
7afe21cc RK |
112 | Constants and quantity numbers |
113 | ||
114 | When a quantity has a known constant value, that value is stored | |
1bb98cec | 115 | in the appropriate qty_table `const_rtx'. This is in addition to |
7afe21cc RK |
116 | putting the constant in the hash table as is usual for non-regs. |
117 | ||
d45cf215 | 118 | Whether a reg or a constant is preferred is determined by the configuration |
7afe21cc RK |
119 | macro CONST_COSTS and will often depend on the constant value. In any |
120 | event, expressions containing constants can be simplified, by fold_rtx. | |
121 | ||
122 | When a quantity has a known nearly constant value (such as an address | |
1bb98cec DM |
123 | of a stack slot), that value is stored in the appropriate qty_table |
124 | `const_rtx'. | |
7afe21cc RK |
125 | |
126 | Integer constants don't have a machine mode. However, cse | |
127 | determines the intended machine mode from the destination | |
128 | of the instruction that moves the constant. The machine mode | |
129 | is recorded in the hash table along with the actual RTL | |
130 | constant expression so that different modes are kept separate. | |
131 | ||
132 | Other expressions: | |
133 | ||
134 | To record known equivalences among expressions in general | |
135 | we use a hash table called `table'. It has a fixed number of buckets | |
136 | that contain chains of `struct table_elt' elements for expressions. | |
137 | These chains connect the elements whose expressions have the same | |
138 | hash codes. | |
139 | ||
140 | Other chains through the same elements connect the elements which | |
141 | currently have equivalent values. | |
142 | ||
143 | Register references in an expression are canonicalized before hashing | |
1bb98cec | 144 | the expression. This is done using `reg_qty' and qty_table `first_reg'. |
7afe21cc RK |
145 | The hash code of a register reference is computed using the quantity |
146 | number, not the register number. | |
147 | ||
148 | When the value of an expression changes, it is necessary to remove from the | |
149 | hash table not just that expression but all expressions whose values | |
150 | could be different as a result. | |
151 | ||
152 | 1. If the value changing is in memory, except in special cases | |
153 | ANYTHING referring to memory could be changed. That is because | |
154 | nobody knows where a pointer does not point. | |
155 | The function `invalidate_memory' removes what is necessary. | |
156 | ||
157 | The special cases are when the address is constant or is | |
158 | a constant plus a fixed register such as the frame pointer | |
159 | or a static chain pointer. When such addresses are stored in, | |
160 | we can tell exactly which other such addresses must be invalidated | |
161 | due to overlap. `invalidate' does this. | |
162 | All expressions that refer to non-constant | |
163 | memory addresses are also invalidated. `invalidate_memory' does this. | |
164 | ||
165 | 2. If the value changing is a register, all expressions | |
166 | containing references to that register, and only those, | |
167 | must be removed. | |
168 | ||
169 | Because searching the entire hash table for expressions that contain | |
170 | a register is very slow, we try to figure out when it isn't necessary. | |
171 | Precisely, this is necessary only when expressions have been | |
172 | entered in the hash table using this register, and then the value has | |
173 | changed, and then another expression wants to be added to refer to | |
174 | the register's new value. This sequence of circumstances is rare | |
175 | within any one basic block. | |
176 | ||
459281be KH |
177 | `REG_TICK' and `REG_IN_TABLE', accessors for members of |
178 | cse_reg_info, are used to detect this case. REG_TICK (i) is | |
179 | incremented whenever a value is stored in register i. | |
180 | REG_IN_TABLE (i) holds -1 if no references to register i have been | |
181 | entered in the table; otherwise, it contains the value REG_TICK (i) | |
182 | had when the references were entered. If we want to enter a | |
183 | reference and REG_IN_TABLE (i) != REG_TICK (i), we must scan and | |
184 | remove old references. Until we want to enter a new entry, the | |
185 | mere fact that the two vectors don't match makes the entries be | |
186 | ignored if anyone tries to match them. | |
7afe21cc RK |
187 | |
188 | Registers themselves are entered in the hash table as well as in | |
459281be KH |
189 | the equivalent-register chains. However, `REG_TICK' and |
190 | `REG_IN_TABLE' do not apply to expressions which are simple | |
7afe21cc RK |
191 | register references. These expressions are removed from the table |
192 | immediately when they become invalid, and this can be done even if | |
193 | we do not immediately search for all the expressions that refer to | |
194 | the register. | |
195 | ||
196 | A CLOBBER rtx in an instruction invalidates its operand for further | |
197 | reuse. A CLOBBER or SET rtx whose operand is a MEM:BLK | |
198 | invalidates everything that resides in memory. | |
199 | ||
200 | Related expressions: | |
201 | ||
202 | Constant expressions that differ only by an additive integer | |
203 | are called related. When a constant expression is put in | |
204 | the table, the related expression with no constant term | |
205 | is also entered. These are made to point at each other | |
206 | so that it is possible to find out if there exists any | |
207 | register equivalent to an expression related to a given expression. */ | |
278a83b2 | 208 | |
1bb98cec DM |
209 | /* Length of qty_table vector. We know in advance we will not need |
210 | a quantity number this big. */ | |
7afe21cc RK |
211 | |
212 | static int max_qty; | |
213 | ||
214 | /* Next quantity number to be allocated. | |
215 | This is 1 + the largest number needed so far. */ | |
216 | ||
217 | static int next_qty; | |
218 | ||
1bb98cec | 219 | /* Per-qty information tracking. |
7afe21cc | 220 | |
1bb98cec DM |
221 | `first_reg' and `last_reg' track the head and tail of the |
222 | chain of registers which currently contain this quantity. | |
7afe21cc | 223 | |
1bb98cec | 224 | `mode' contains the machine mode of this quantity. |
7afe21cc | 225 | |
1bb98cec DM |
226 | `const_rtx' holds the rtx of the constant value of this |
227 | quantity, if known. A summations of the frame/arg pointer | |
228 | and a constant can also be entered here. When this holds | |
229 | a known value, `const_insn' is the insn which stored the | |
230 | constant value. | |
7afe21cc | 231 | |
1bb98cec DM |
232 | `comparison_{code,const,qty}' are used to track when a |
233 | comparison between a quantity and some constant or register has | |
234 | been passed. In such a case, we know the results of the comparison | |
235 | in case we see it again. These members record a comparison that | |
236 | is known to be true. `comparison_code' holds the rtx code of such | |
237 | a comparison, else it is set to UNKNOWN and the other two | |
238 | comparison members are undefined. `comparison_const' holds | |
239 | the constant being compared against, or zero if the comparison | |
240 | is not against a constant. `comparison_qty' holds the quantity | |
241 | being compared against when the result is known. If the comparison | |
242 | is not with a register, `comparison_qty' is -1. */ | |
7afe21cc | 243 | |
1bb98cec DM |
244 | struct qty_table_elem |
245 | { | |
246 | rtx const_rtx; | |
247 | rtx const_insn; | |
248 | rtx comparison_const; | |
249 | int comparison_qty; | |
770ae6cc | 250 | unsigned int first_reg, last_reg; |
496324d0 DN |
251 | /* The sizes of these fields should match the sizes of the |
252 | code and mode fields of struct rtx_def (see rtl.h). */ | |
253 | ENUM_BITFIELD(rtx_code) comparison_code : 16; | |
254 | ENUM_BITFIELD(machine_mode) mode : 8; | |
1bb98cec | 255 | }; |
7afe21cc | 256 | |
1bb98cec DM |
257 | /* The table of all qtys, indexed by qty number. */ |
258 | static struct qty_table_elem *qty_table; | |
7afe21cc | 259 | |
fc188d37 AK |
260 | /* Structure used to pass arguments via for_each_rtx to function |
261 | cse_change_cc_mode. */ | |
262 | struct change_cc_mode_args | |
263 | { | |
264 | rtx insn; | |
265 | rtx newreg; | |
266 | }; | |
267 | ||
7afe21cc RK |
268 | #ifdef HAVE_cc0 |
269 | /* For machines that have a CC0, we do not record its value in the hash | |
270 | table since its use is guaranteed to be the insn immediately following | |
271 | its definition and any other insn is presumed to invalidate it. | |
272 | ||
96fb470d SB |
273 | Instead, we store below the current and last value assigned to CC0. |
274 | If it should happen to be a constant, it is stored in preference | |
275 | to the actual assigned value. In case it is a constant, we store | |
276 | the mode in which the constant should be interpreted. */ | |
7afe21cc | 277 | |
96fb470d SB |
278 | static rtx this_insn_cc0, prev_insn_cc0; |
279 | static enum machine_mode this_insn_cc0_mode, prev_insn_cc0_mode; | |
4977bab6 | 280 | #endif |
7afe21cc RK |
281 | |
282 | /* Insn being scanned. */ | |
283 | ||
284 | static rtx this_insn; | |
285 | ||
71d306d1 DE |
286 | /* Index by register number, gives the number of the next (or |
287 | previous) register in the chain of registers sharing the same | |
7afe21cc RK |
288 | value. |
289 | ||
290 | Or -1 if this register is at the end of the chain. | |
291 | ||
459281be | 292 | If REG_QTY (N) == -N - 1, reg_eqv_table[N].next is undefined. */ |
1bb98cec DM |
293 | |
294 | /* Per-register equivalence chain. */ | |
295 | struct reg_eqv_elem | |
296 | { | |
297 | int next, prev; | |
298 | }; | |
7afe21cc | 299 | |
1bb98cec DM |
300 | /* The table of all register equivalence chains. */ |
301 | static struct reg_eqv_elem *reg_eqv_table; | |
7afe21cc | 302 | |
14a774a9 RK |
303 | struct cse_reg_info |
304 | { | |
bc5e3b54 KH |
305 | /* The timestamp at which this register is initialized. */ |
306 | unsigned int timestamp; | |
9b1549b8 DM |
307 | |
308 | /* The quantity number of the register's current contents. */ | |
309 | int reg_qty; | |
310 | ||
311 | /* The number of times the register has been altered in the current | |
312 | basic block. */ | |
313 | int reg_tick; | |
314 | ||
30f72379 MM |
315 | /* The REG_TICK value at which rtx's containing this register are |
316 | valid in the hash table. If this does not equal the current | |
317 | reg_tick value, such expressions existing in the hash table are | |
318 | invalid. */ | |
319 | int reg_in_table; | |
46081bb3 SH |
320 | |
321 | /* The SUBREG that was set when REG_TICK was last incremented. Set | |
322 | to -1 if the last store was to the whole register, not a subreg. */ | |
5dd78e9a | 323 | unsigned int subreg_ticked; |
30f72379 | 324 | }; |
7afe21cc | 325 | |
bc5e3b54 | 326 | /* A table of cse_reg_info indexed by register numbers. */ |
f00822b2 | 327 | static struct cse_reg_info *cse_reg_info_table; |
c1edba58 | 328 | |
bc5e3b54 KH |
329 | /* The size of the above table. */ |
330 | static unsigned int cse_reg_info_table_size; | |
9b1549b8 | 331 | |
bc5e3b54 KH |
332 | /* The index of the first entry that has not been initialized. */ |
333 | static unsigned int cse_reg_info_table_first_uninitialized; | |
7afe21cc | 334 | |
bc5e3b54 | 335 | /* The timestamp at the beginning of the current run of |
932ad4d9 SB |
336 | cse_extended_basic_block. We increment this variable at the beginning of |
337 | the current run of cse_extended_basic_block. The timestamp field of a | |
bc5e3b54 KH |
338 | cse_reg_info entry matches the value of this variable if and only |
339 | if the entry has been initialized during the current run of | |
932ad4d9 | 340 | cse_extended_basic_block. */ |
bc5e3b54 | 341 | static unsigned int cse_reg_info_timestamp; |
7afe21cc | 342 | |
278a83b2 | 343 | /* A HARD_REG_SET containing all the hard registers for which there is |
7afe21cc RK |
344 | currently a REG expression in the hash table. Note the difference |
345 | from the above variables, which indicate if the REG is mentioned in some | |
346 | expression in the table. */ | |
347 | ||
348 | static HARD_REG_SET hard_regs_in_table; | |
349 | ||
7afe21cc RK |
350 | /* CUID of insn that starts the basic block currently being cse-processed. */ |
351 | ||
352 | static int cse_basic_block_start; | |
353 | ||
354 | /* CUID of insn that ends the basic block currently being cse-processed. */ | |
355 | ||
356 | static int cse_basic_block_end; | |
357 | ||
358 | /* Vector mapping INSN_UIDs to cuids. | |
d45cf215 | 359 | The cuids are like uids but increase monotonically always. |
7afe21cc RK |
360 | We use them to see whether a reg is used outside a given basic block. */ |
361 | ||
906c4e36 | 362 | static int *uid_cuid; |
7afe21cc | 363 | |
164c8956 RK |
364 | /* Highest UID in UID_CUID. */ |
365 | static int max_uid; | |
366 | ||
7afe21cc RK |
367 | /* Get the cuid of an insn. */ |
368 | ||
369 | #define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)]) | |
370 | ||
371 | /* Nonzero if cse has altered conditional jump insns | |
372 | in such a way that jump optimization should be redone. */ | |
373 | ||
374 | static int cse_jumps_altered; | |
375 | ||
f85cc4cb RK |
376 | /* Nonzero if we put a LABEL_REF into the hash table for an INSN without a |
377 | REG_LABEL, we have to rerun jump after CSE to put in the note. */ | |
a5dfb4ee RK |
378 | static int recorded_label_ref; |
379 | ||
7afe21cc RK |
380 | /* canon_hash stores 1 in do_not_record |
381 | if it notices a reference to CC0, PC, or some other volatile | |
382 | subexpression. */ | |
383 | ||
384 | static int do_not_record; | |
385 | ||
386 | /* canon_hash stores 1 in hash_arg_in_memory | |
387 | if it notices a reference to memory within the expression being hashed. */ | |
388 | ||
389 | static int hash_arg_in_memory; | |
390 | ||
7afe21cc RK |
391 | /* The hash table contains buckets which are chains of `struct table_elt's, |
392 | each recording one expression's information. | |
393 | That expression is in the `exp' field. | |
394 | ||
db048faf MM |
395 | The canon_exp field contains a canonical (from the point of view of |
396 | alias analysis) version of the `exp' field. | |
397 | ||
7afe21cc RK |
398 | Those elements with the same hash code are chained in both directions |
399 | through the `next_same_hash' and `prev_same_hash' fields. | |
400 | ||
401 | Each set of expressions with equivalent values | |
402 | are on a two-way chain through the `next_same_value' | |
403 | and `prev_same_value' fields, and all point with | |
404 | the `first_same_value' field at the first element in | |
405 | that chain. The chain is in order of increasing cost. | |
406 | Each element's cost value is in its `cost' field. | |
407 | ||
408 | The `in_memory' field is nonzero for elements that | |
409 | involve any reference to memory. These elements are removed | |
410 | whenever a write is done to an unidentified location in memory. | |
411 | To be safe, we assume that a memory address is unidentified unless | |
412 | the address is either a symbol constant or a constant plus | |
413 | the frame pointer or argument pointer. | |
414 | ||
7afe21cc RK |
415 | The `related_value' field is used to connect related expressions |
416 | (that differ by adding an integer). | |
417 | The related expressions are chained in a circular fashion. | |
418 | `related_value' is zero for expressions for which this | |
419 | chain is not useful. | |
420 | ||
421 | The `cost' field stores the cost of this element's expression. | |
630c79be BS |
422 | The `regcost' field stores the value returned by approx_reg_cost for |
423 | this element's expression. | |
7afe21cc RK |
424 | |
425 | The `is_const' flag is set if the element is a constant (including | |
426 | a fixed address). | |
427 | ||
428 | The `flag' field is used as a temporary during some search routines. | |
429 | ||
430 | The `mode' field is usually the same as GET_MODE (`exp'), but | |
431 | if `exp' is a CONST_INT and has no machine mode then the `mode' | |
432 | field is the mode it was being used as. Each constant is | |
433 | recorded separately for each mode it is used with. */ | |
434 | ||
7afe21cc RK |
435 | struct table_elt |
436 | { | |
437 | rtx exp; | |
db048faf | 438 | rtx canon_exp; |
7afe21cc RK |
439 | struct table_elt *next_same_hash; |
440 | struct table_elt *prev_same_hash; | |
441 | struct table_elt *next_same_value; | |
442 | struct table_elt *prev_same_value; | |
443 | struct table_elt *first_same_value; | |
444 | struct table_elt *related_value; | |
445 | int cost; | |
630c79be | 446 | int regcost; |
496324d0 DN |
447 | /* The size of this field should match the size |
448 | of the mode field of struct rtx_def (see rtl.h). */ | |
449 | ENUM_BITFIELD(machine_mode) mode : 8; | |
7afe21cc | 450 | char in_memory; |
7afe21cc RK |
451 | char is_const; |
452 | char flag; | |
453 | }; | |
454 | ||
7afe21cc RK |
455 | /* We don't want a lot of buckets, because we rarely have very many |
456 | things stored in the hash table, and a lot of buckets slows | |
457 | down a lot of loops that happen frequently. */ | |
9b1549b8 DM |
458 | #define HASH_SHIFT 5 |
459 | #define HASH_SIZE (1 << HASH_SHIFT) | |
460 | #define HASH_MASK (HASH_SIZE - 1) | |
7afe21cc RK |
461 | |
462 | /* Compute hash code of X in mode M. Special-case case where X is a pseudo | |
463 | register (hard registers may require `do_not_record' to be set). */ | |
464 | ||
465 | #define HASH(X, M) \ | |
f8cfc6aa | 466 | ((REG_P (X) && REGNO (X) >= FIRST_PSEUDO_REGISTER \ |
9b1549b8 DM |
467 | ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X))) \ |
468 | : canon_hash (X, M)) & HASH_MASK) | |
7afe21cc | 469 | |
0516f6fe SB |
470 | /* Like HASH, but without side-effects. */ |
471 | #define SAFE_HASH(X, M) \ | |
472 | ((REG_P (X) && REGNO (X) >= FIRST_PSEUDO_REGISTER \ | |
473 | ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X))) \ | |
474 | : safe_hash (X, M)) & HASH_MASK) | |
475 | ||
630c79be BS |
476 | /* Determine whether register number N is considered a fixed register for the |
477 | purpose of approximating register costs. | |
7afe21cc RK |
478 | It is desirable to replace other regs with fixed regs, to reduce need for |
479 | non-fixed hard regs. | |
553687c9 | 480 | A reg wins if it is either the frame pointer or designated as fixed. */ |
7afe21cc | 481 | #define FIXED_REGNO_P(N) \ |
8bc169f2 | 482 | ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \ |
6ab832bc | 483 | || fixed_regs[N] || global_regs[N]) |
7afe21cc RK |
484 | |
485 | /* Compute cost of X, as stored in the `cost' field of a table_elt. Fixed | |
ac07e066 RK |
486 | hard registers and pointers into the frame are the cheapest with a cost |
487 | of 0. Next come pseudos with a cost of one and other hard registers with | |
488 | a cost of 2. Aside from these special cases, call `rtx_cost'. */ | |
489 | ||
d67fb775 SB |
490 | #define CHEAP_REGNO(N) \ |
491 | (REGNO_PTR_FRAME_P(N) \ | |
492 | || (HARD_REGISTER_NUM_P (N) \ | |
e7bb59fa | 493 | && FIXED_REGNO_P (N) && REGNO_REG_CLASS (N) != NO_REGS)) |
7afe21cc | 494 | |
f8cfc6aa JQ |
495 | #define COST(X) (REG_P (X) ? 0 : notreg_cost (X, SET)) |
496 | #define COST_IN(X,OUTER) (REG_P (X) ? 0 : notreg_cost (X, OUTER)) | |
7afe21cc | 497 | |
30f72379 MM |
498 | /* Get the number of times this register has been updated in this |
499 | basic block. */ | |
500 | ||
bc5e3b54 | 501 | #define REG_TICK(N) (get_cse_reg_info (N)->reg_tick) |
30f72379 MM |
502 | |
503 | /* Get the point at which REG was recorded in the table. */ | |
504 | ||
bc5e3b54 | 505 | #define REG_IN_TABLE(N) (get_cse_reg_info (N)->reg_in_table) |
30f72379 | 506 | |
46081bb3 SH |
507 | /* Get the SUBREG set at the last increment to REG_TICK (-1 if not a |
508 | SUBREG). */ | |
509 | ||
bc5e3b54 | 510 | #define SUBREG_TICKED(N) (get_cse_reg_info (N)->subreg_ticked) |
46081bb3 | 511 | |
30f72379 MM |
512 | /* Get the quantity number for REG. */ |
513 | ||
bc5e3b54 | 514 | #define REG_QTY(N) (get_cse_reg_info (N)->reg_qty) |
30f72379 | 515 | |
7afe21cc | 516 | /* Determine if the quantity number for register X represents a valid index |
1bb98cec | 517 | into the qty_table. */ |
7afe21cc | 518 | |
08a69267 | 519 | #define REGNO_QTY_VALID_P(N) (REG_QTY (N) >= 0) |
7afe21cc | 520 | |
9b1549b8 | 521 | static struct table_elt *table[HASH_SIZE]; |
7afe21cc RK |
522 | |
523 | /* Chain of `struct table_elt's made so far for this function | |
524 | but currently removed from the table. */ | |
525 | ||
526 | static struct table_elt *free_element_chain; | |
527 | ||
7afe21cc RK |
528 | /* Set to the cost of a constant pool reference if one was found for a |
529 | symbolic constant. If this was found, it means we should try to | |
530 | convert constants into constant pool entries if they don't fit in | |
531 | the insn. */ | |
532 | ||
533 | static int constant_pool_entries_cost; | |
dd0ba281 | 534 | static int constant_pool_entries_regcost; |
7afe21cc | 535 | |
932ad4d9 SB |
536 | /* This data describes a block that will be processed by |
537 | cse_extended_basic_block. */ | |
6cd4575e | 538 | |
14a774a9 RK |
539 | struct cse_basic_block_data |
540 | { | |
6cd4575e RK |
541 | /* Lowest CUID value of insns in block. */ |
542 | int low_cuid; | |
543 | /* Highest CUID value of insns in block. */ | |
544 | int high_cuid; | |
545 | /* Total number of SETs in block. */ | |
546 | int nsets; | |
6cd4575e RK |
547 | /* Size of current branch path, if any. */ |
548 | int path_size; | |
932ad4d9 | 549 | /* Current path, indicating which basic_blocks will be processed. */ |
14a774a9 RK |
550 | struct branch_path |
551 | { | |
932ad4d9 SB |
552 | /* The basic block for this path entry. */ |
553 | basic_block bb; | |
9bf8cfbf | 554 | } *path; |
6cd4575e RK |
555 | }; |
556 | ||
932ad4d9 SB |
557 | /* A simple bitmap to track which basic blocks have been visited |
558 | already as part of an already processed extended basic block. */ | |
559 | static sbitmap cse_visited_basic_blocks; | |
560 | ||
7080f735 AJ |
561 | static bool fixed_base_plus_p (rtx x); |
562 | static int notreg_cost (rtx, enum rtx_code); | |
563 | static int approx_reg_cost_1 (rtx *, void *); | |
564 | static int approx_reg_cost (rtx); | |
56ae04af | 565 | static int preferable (int, int, int, int); |
7080f735 AJ |
566 | static void new_basic_block (void); |
567 | static void make_new_qty (unsigned int, enum machine_mode); | |
568 | static void make_regs_eqv (unsigned int, unsigned int); | |
569 | static void delete_reg_equiv (unsigned int); | |
570 | static int mention_regs (rtx); | |
571 | static int insert_regs (rtx, struct table_elt *, int); | |
572 | static void remove_from_table (struct table_elt *, unsigned); | |
573 | static struct table_elt *lookup (rtx, unsigned, enum machine_mode); | |
574 | static struct table_elt *lookup_for_remove (rtx, unsigned, enum machine_mode); | |
575 | static rtx lookup_as_function (rtx, enum rtx_code); | |
576 | static struct table_elt *insert (rtx, struct table_elt *, unsigned, | |
577 | enum machine_mode); | |
578 | static void merge_equiv_classes (struct table_elt *, struct table_elt *); | |
579 | static void invalidate (rtx, enum machine_mode); | |
580 | static int cse_rtx_varies_p (rtx, int); | |
581 | static void remove_invalid_refs (unsigned int); | |
582 | static void remove_invalid_subreg_refs (unsigned int, unsigned int, | |
583 | enum machine_mode); | |
584 | static void rehash_using_reg (rtx); | |
585 | static void invalidate_memory (void); | |
586 | static void invalidate_for_call (void); | |
587 | static rtx use_related_value (rtx, struct table_elt *); | |
0516f6fe SB |
588 | |
589 | static inline unsigned canon_hash (rtx, enum machine_mode); | |
590 | static inline unsigned safe_hash (rtx, enum machine_mode); | |
591 | static unsigned hash_rtx_string (const char *); | |
592 | ||
7080f735 | 593 | static rtx canon_reg (rtx, rtx); |
7080f735 AJ |
594 | static enum rtx_code find_comparison_args (enum rtx_code, rtx *, rtx *, |
595 | enum machine_mode *, | |
596 | enum machine_mode *); | |
597 | static rtx fold_rtx (rtx, rtx); | |
598 | static rtx equiv_constant (rtx); | |
0129d079 | 599 | static void record_jump_equiv (rtx, bool); |
7080f735 AJ |
600 | static void record_jump_cond (enum rtx_code, enum machine_mode, rtx, rtx, |
601 | int); | |
602 | static void cse_insn (rtx, rtx); | |
932ad4d9 | 603 | static void cse_prescan_path (struct cse_basic_block_data *); |
7080f735 AJ |
604 | static void invalidate_from_clobbers (rtx); |
605 | static rtx cse_process_notes (rtx, rtx); | |
932ad4d9 | 606 | static void cse_extended_basic_block (struct cse_basic_block_data *); |
b92ba6ff | 607 | static void count_reg_usage (rtx, int *, rtx, int); |
7080f735 AJ |
608 | static int check_for_label_ref (rtx *, void *); |
609 | extern void dump_class (struct table_elt*); | |
bc5e3b54 KH |
610 | static void get_cse_reg_info_1 (unsigned int regno); |
611 | static struct cse_reg_info * get_cse_reg_info (unsigned int regno); | |
7080f735 AJ |
612 | static int check_dependence (rtx *, void *); |
613 | ||
614 | static void flush_hash_table (void); | |
615 | static bool insn_live_p (rtx, int *); | |
616 | static bool set_live_p (rtx, rtx, int *); | |
617 | static bool dead_libcall_p (rtx, int *); | |
e129d93a | 618 | static int cse_change_cc_mode (rtx *, void *); |
fc188d37 | 619 | static void cse_change_cc_mode_insn (rtx, rtx); |
e129d93a ILT |
620 | static void cse_change_cc_mode_insns (rtx, rtx, rtx); |
621 | static enum machine_mode cse_cc_succs (basic_block, rtx, rtx, bool); | |
7afe21cc | 622 | \f |
2f93eea8 PB |
623 | |
624 | #undef RTL_HOOKS_GEN_LOWPART | |
625 | #define RTL_HOOKS_GEN_LOWPART gen_lowpart_if_possible | |
626 | ||
627 | static const struct rtl_hooks cse_rtl_hooks = RTL_HOOKS_INITIALIZER; | |
628 | \f | |
4977bab6 ZW |
629 | /* Nonzero if X has the form (PLUS frame-pointer integer). We check for |
630 | virtual regs here because the simplify_*_operation routines are called | |
631 | by integrate.c, which is called before virtual register instantiation. */ | |
632 | ||
633 | static bool | |
7080f735 | 634 | fixed_base_plus_p (rtx x) |
4977bab6 ZW |
635 | { |
636 | switch (GET_CODE (x)) | |
637 | { | |
638 | case REG: | |
639 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx) | |
640 | return true; | |
641 | if (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
642 | return true; | |
643 | if (REGNO (x) >= FIRST_VIRTUAL_REGISTER | |
644 | && REGNO (x) <= LAST_VIRTUAL_REGISTER) | |
645 | return true; | |
646 | return false; | |
647 | ||
648 | case PLUS: | |
649 | if (GET_CODE (XEXP (x, 1)) != CONST_INT) | |
650 | return false; | |
651 | return fixed_base_plus_p (XEXP (x, 0)); | |
652 | ||
4977bab6 ZW |
653 | default: |
654 | return false; | |
655 | } | |
656 | } | |
657 | ||
a4c6502a MM |
658 | /* Dump the expressions in the equivalence class indicated by CLASSP. |
659 | This function is used only for debugging. */ | |
a0153051 | 660 | void |
7080f735 | 661 | dump_class (struct table_elt *classp) |
a4c6502a MM |
662 | { |
663 | struct table_elt *elt; | |
664 | ||
665 | fprintf (stderr, "Equivalence chain for "); | |
666 | print_rtl (stderr, classp->exp); | |
667 | fprintf (stderr, ": \n"); | |
278a83b2 | 668 | |
a4c6502a MM |
669 | for (elt = classp->first_same_value; elt; elt = elt->next_same_value) |
670 | { | |
671 | print_rtl (stderr, elt->exp); | |
672 | fprintf (stderr, "\n"); | |
673 | } | |
674 | } | |
675 | ||
630c79be | 676 | /* Subroutine of approx_reg_cost; called through for_each_rtx. */ |
be8ac49a | 677 | |
630c79be | 678 | static int |
7080f735 | 679 | approx_reg_cost_1 (rtx *xp, void *data) |
630c79be BS |
680 | { |
681 | rtx x = *xp; | |
c863f8c2 | 682 | int *cost_p = data; |
630c79be | 683 | |
f8cfc6aa | 684 | if (x && REG_P (x)) |
c863f8c2 DM |
685 | { |
686 | unsigned int regno = REGNO (x); | |
687 | ||
688 | if (! CHEAP_REGNO (regno)) | |
689 | { | |
690 | if (regno < FIRST_PSEUDO_REGISTER) | |
691 | { | |
692 | if (SMALL_REGISTER_CLASSES) | |
693 | return 1; | |
694 | *cost_p += 2; | |
695 | } | |
696 | else | |
697 | *cost_p += 1; | |
698 | } | |
699 | } | |
700 | ||
630c79be BS |
701 | return 0; |
702 | } | |
703 | ||
704 | /* Return an estimate of the cost of the registers used in an rtx. | |
705 | This is mostly the number of different REG expressions in the rtx; | |
a1f300c0 | 706 | however for some exceptions like fixed registers we use a cost of |
f1c1dfc3 | 707 | 0. If any other hard register reference occurs, return MAX_COST. */ |
630c79be BS |
708 | |
709 | static int | |
7080f735 | 710 | approx_reg_cost (rtx x) |
630c79be | 711 | { |
630c79be | 712 | int cost = 0; |
f1c1dfc3 | 713 | |
c863f8c2 DM |
714 | if (for_each_rtx (&x, approx_reg_cost_1, (void *) &cost)) |
715 | return MAX_COST; | |
630c79be | 716 | |
c863f8c2 | 717 | return cost; |
630c79be BS |
718 | } |
719 | ||
720 | /* Return a negative value if an rtx A, whose costs are given by COST_A | |
721 | and REGCOST_A, is more desirable than an rtx B. | |
722 | Return a positive value if A is less desirable, or 0 if the two are | |
723 | equally good. */ | |
724 | static int | |
56ae04af | 725 | preferable (int cost_a, int regcost_a, int cost_b, int regcost_b) |
630c79be | 726 | { |
423adbb9 | 727 | /* First, get rid of cases involving expressions that are entirely |
f1c1dfc3 BS |
728 | unwanted. */ |
729 | if (cost_a != cost_b) | |
730 | { | |
731 | if (cost_a == MAX_COST) | |
732 | return 1; | |
733 | if (cost_b == MAX_COST) | |
734 | return -1; | |
735 | } | |
736 | ||
737 | /* Avoid extending lifetimes of hardregs. */ | |
738 | if (regcost_a != regcost_b) | |
739 | { | |
740 | if (regcost_a == MAX_COST) | |
741 | return 1; | |
742 | if (regcost_b == MAX_COST) | |
743 | return -1; | |
744 | } | |
745 | ||
746 | /* Normal operation costs take precedence. */ | |
630c79be BS |
747 | if (cost_a != cost_b) |
748 | return cost_a - cost_b; | |
f1c1dfc3 | 749 | /* Only if these are identical consider effects on register pressure. */ |
630c79be BS |
750 | if (regcost_a != regcost_b) |
751 | return regcost_a - regcost_b; | |
752 | return 0; | |
753 | } | |
754 | ||
954a5693 RK |
755 | /* Internal function, to compute cost when X is not a register; called |
756 | from COST macro to keep it simple. */ | |
757 | ||
758 | static int | |
7080f735 | 759 | notreg_cost (rtx x, enum rtx_code outer) |
954a5693 RK |
760 | { |
761 | return ((GET_CODE (x) == SUBREG | |
f8cfc6aa | 762 | && REG_P (SUBREG_REG (x)) |
954a5693 RK |
763 | && GET_MODE_CLASS (GET_MODE (x)) == MODE_INT |
764 | && GET_MODE_CLASS (GET_MODE (SUBREG_REG (x))) == MODE_INT | |
765 | && (GET_MODE_SIZE (GET_MODE (x)) | |
766 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) | |
767 | && subreg_lowpart_p (x) | |
768 | && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (x)), | |
769 | GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))))) | |
630c79be | 770 | ? 0 |
f2fa288f | 771 | : rtx_cost (x, outer) * 2); |
954a5693 RK |
772 | } |
773 | ||
01329426 | 774 | \f |
bc5e3b54 | 775 | /* Initialize CSE_REG_INFO_TABLE. */ |
9b1549b8 | 776 | |
bc5e3b54 KH |
777 | static void |
778 | init_cse_reg_info (unsigned int nregs) | |
779 | { | |
780 | /* Do we need to grow the table? */ | |
781 | if (nregs > cse_reg_info_table_size) | |
30f72379 | 782 | { |
bc5e3b54 KH |
783 | unsigned int new_size; |
784 | ||
785 | if (cse_reg_info_table_size < 2048) | |
30f72379 | 786 | { |
bc5e3b54 KH |
787 | /* Compute a new size that is a power of 2 and no smaller |
788 | than the large of NREGS and 64. */ | |
789 | new_size = (cse_reg_info_table_size | |
790 | ? cse_reg_info_table_size : 64); | |
791 | ||
792 | while (new_size < nregs) | |
793 | new_size *= 2; | |
30f72379 MM |
794 | } |
795 | else | |
1590d0d4 | 796 | { |
bc5e3b54 KH |
797 | /* If we need a big table, allocate just enough to hold |
798 | NREGS registers. */ | |
799 | new_size = nregs; | |
1590d0d4 | 800 | } |
9b1549b8 | 801 | |
bc5e3b54 | 802 | /* Reallocate the table with NEW_SIZE entries. */ |
a811c672 KH |
803 | if (cse_reg_info_table) |
804 | free (cse_reg_info_table); | |
5ed6ace5 | 805 | cse_reg_info_table = XNEWVEC (struct cse_reg_info, new_size); |
bc5e3b54 | 806 | cse_reg_info_table_size = new_size; |
a811c672 | 807 | cse_reg_info_table_first_uninitialized = 0; |
bc5e3b54 KH |
808 | } |
809 | ||
810 | /* Do we have all of the first NREGS entries initialized? */ | |
811 | if (cse_reg_info_table_first_uninitialized < nregs) | |
812 | { | |
813 | unsigned int old_timestamp = cse_reg_info_timestamp - 1; | |
814 | unsigned int i; | |
815 | ||
816 | /* Put the old timestamp on newly allocated entries so that they | |
817 | will all be considered out of date. We do not touch those | |
818 | entries beyond the first NREGS entries to be nice to the | |
819 | virtual memory. */ | |
820 | for (i = cse_reg_info_table_first_uninitialized; i < nregs; i++) | |
821 | cse_reg_info_table[i].timestamp = old_timestamp; | |
30f72379 | 822 | |
bc5e3b54 | 823 | cse_reg_info_table_first_uninitialized = nregs; |
30f72379 | 824 | } |
bc5e3b54 KH |
825 | } |
826 | ||
a52aff23 | 827 | /* Given REGNO, initialize the cse_reg_info entry for REGNO. */ |
bc5e3b54 KH |
828 | |
829 | static void | |
830 | get_cse_reg_info_1 (unsigned int regno) | |
831 | { | |
832 | /* Set TIMESTAMP field to CSE_REG_INFO_TIMESTAMP so that this | |
833 | entry will be considered to have been initialized. */ | |
834 | cse_reg_info_table[regno].timestamp = cse_reg_info_timestamp; | |
835 | ||
836 | /* Initialize the rest of the entry. */ | |
837 | cse_reg_info_table[regno].reg_tick = 1; | |
838 | cse_reg_info_table[regno].reg_in_table = -1; | |
839 | cse_reg_info_table[regno].subreg_ticked = -1; | |
840 | cse_reg_info_table[regno].reg_qty = -regno - 1; | |
841 | } | |
842 | ||
843 | /* Find a cse_reg_info entry for REGNO. */ | |
30f72379 | 844 | |
bc5e3b54 KH |
845 | static inline struct cse_reg_info * |
846 | get_cse_reg_info (unsigned int regno) | |
847 | { | |
848 | struct cse_reg_info *p = &cse_reg_info_table[regno]; | |
849 | ||
782c0a3e KH |
850 | /* If this entry has not been initialized, go ahead and initialize |
851 | it. */ | |
bc5e3b54 KH |
852 | if (p->timestamp != cse_reg_info_timestamp) |
853 | get_cse_reg_info_1 (regno); | |
30f72379 | 854 | |
9b1549b8 | 855 | return p; |
30f72379 MM |
856 | } |
857 | ||
7afe21cc RK |
858 | /* Clear the hash table and initialize each register with its own quantity, |
859 | for a new basic block. */ | |
860 | ||
861 | static void | |
7080f735 | 862 | new_basic_block (void) |
7afe21cc | 863 | { |
b3694847 | 864 | int i; |
7afe21cc | 865 | |
08a69267 | 866 | next_qty = 0; |
7afe21cc | 867 | |
a52aff23 | 868 | /* Invalidate cse_reg_info_table. */ |
bc5e3b54 | 869 | cse_reg_info_timestamp++; |
7afe21cc | 870 | |
bc5e3b54 | 871 | /* Clear out hash table state for this pass. */ |
7afe21cc RK |
872 | CLEAR_HARD_REG_SET (hard_regs_in_table); |
873 | ||
874 | /* The per-quantity values used to be initialized here, but it is | |
875 | much faster to initialize each as it is made in `make_new_qty'. */ | |
876 | ||
9b1549b8 | 877 | for (i = 0; i < HASH_SIZE; i++) |
7afe21cc | 878 | { |
9b1549b8 DM |
879 | struct table_elt *first; |
880 | ||
881 | first = table[i]; | |
882 | if (first != NULL) | |
7afe21cc | 883 | { |
9b1549b8 DM |
884 | struct table_elt *last = first; |
885 | ||
886 | table[i] = NULL; | |
887 | ||
888 | while (last->next_same_hash != NULL) | |
889 | last = last->next_same_hash; | |
890 | ||
891 | /* Now relink this hash entire chain into | |
892 | the free element list. */ | |
893 | ||
894 | last->next_same_hash = free_element_chain; | |
895 | free_element_chain = first; | |
7afe21cc RK |
896 | } |
897 | } | |
898 | ||
7afe21cc RK |
899 | #ifdef HAVE_cc0 |
900 | prev_insn_cc0 = 0; | |
901 | #endif | |
902 | } | |
903 | ||
1bb98cec DM |
904 | /* Say that register REG contains a quantity in mode MODE not in any |
905 | register before and initialize that quantity. */ | |
7afe21cc RK |
906 | |
907 | static void | |
7080f735 | 908 | make_new_qty (unsigned int reg, enum machine_mode mode) |
7afe21cc | 909 | { |
b3694847 SS |
910 | int q; |
911 | struct qty_table_elem *ent; | |
912 | struct reg_eqv_elem *eqv; | |
7afe21cc | 913 | |
341c100f | 914 | gcc_assert (next_qty < max_qty); |
7afe21cc | 915 | |
30f72379 | 916 | q = REG_QTY (reg) = next_qty++; |
1bb98cec DM |
917 | ent = &qty_table[q]; |
918 | ent->first_reg = reg; | |
919 | ent->last_reg = reg; | |
920 | ent->mode = mode; | |
921 | ent->const_rtx = ent->const_insn = NULL_RTX; | |
922 | ent->comparison_code = UNKNOWN; | |
923 | ||
924 | eqv = ®_eqv_table[reg]; | |
925 | eqv->next = eqv->prev = -1; | |
7afe21cc RK |
926 | } |
927 | ||
928 | /* Make reg NEW equivalent to reg OLD. | |
929 | OLD is not changing; NEW is. */ | |
930 | ||
931 | static void | |
7080f735 | 932 | make_regs_eqv (unsigned int new, unsigned int old) |
7afe21cc | 933 | { |
770ae6cc RK |
934 | unsigned int lastr, firstr; |
935 | int q = REG_QTY (old); | |
936 | struct qty_table_elem *ent; | |
1bb98cec DM |
937 | |
938 | ent = &qty_table[q]; | |
7afe21cc RK |
939 | |
940 | /* Nothing should become eqv until it has a "non-invalid" qty number. */ | |
341c100f | 941 | gcc_assert (REGNO_QTY_VALID_P (old)); |
7afe21cc | 942 | |
30f72379 | 943 | REG_QTY (new) = q; |
1bb98cec DM |
944 | firstr = ent->first_reg; |
945 | lastr = ent->last_reg; | |
7afe21cc RK |
946 | |
947 | /* Prefer fixed hard registers to anything. Prefer pseudo regs to other | |
948 | hard regs. Among pseudos, if NEW will live longer than any other reg | |
949 | of the same qty, and that is beyond the current basic block, | |
950 | make it the new canonical replacement for this qty. */ | |
951 | if (! (firstr < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (firstr)) | |
952 | /* Certain fixed registers might be of the class NO_REGS. This means | |
953 | that not only can they not be allocated by the compiler, but | |
830a38ee | 954 | they cannot be used in substitutions or canonicalizations |
7afe21cc RK |
955 | either. */ |
956 | && (new >= FIRST_PSEUDO_REGISTER || REGNO_REG_CLASS (new) != NO_REGS) | |
957 | && ((new < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (new)) | |
958 | || (new >= FIRST_PSEUDO_REGISTER | |
959 | && (firstr < FIRST_PSEUDO_REGISTER | |
b1f21e0a MM |
960 | || ((uid_cuid[REGNO_LAST_UID (new)] > cse_basic_block_end |
961 | || (uid_cuid[REGNO_FIRST_UID (new)] | |
7afe21cc | 962 | < cse_basic_block_start)) |
b1f21e0a MM |
963 | && (uid_cuid[REGNO_LAST_UID (new)] |
964 | > uid_cuid[REGNO_LAST_UID (firstr)])))))) | |
7afe21cc | 965 | { |
1bb98cec DM |
966 | reg_eqv_table[firstr].prev = new; |
967 | reg_eqv_table[new].next = firstr; | |
968 | reg_eqv_table[new].prev = -1; | |
969 | ent->first_reg = new; | |
7afe21cc RK |
970 | } |
971 | else | |
972 | { | |
973 | /* If NEW is a hard reg (known to be non-fixed), insert at end. | |
974 | Otherwise, insert before any non-fixed hard regs that are at the | |
975 | end. Registers of class NO_REGS cannot be used as an | |
976 | equivalent for anything. */ | |
1bb98cec | 977 | while (lastr < FIRST_PSEUDO_REGISTER && reg_eqv_table[lastr].prev >= 0 |
7afe21cc RK |
978 | && (REGNO_REG_CLASS (lastr) == NO_REGS || ! FIXED_REGNO_P (lastr)) |
979 | && new >= FIRST_PSEUDO_REGISTER) | |
1bb98cec DM |
980 | lastr = reg_eqv_table[lastr].prev; |
981 | reg_eqv_table[new].next = reg_eqv_table[lastr].next; | |
982 | if (reg_eqv_table[lastr].next >= 0) | |
983 | reg_eqv_table[reg_eqv_table[lastr].next].prev = new; | |
7afe21cc | 984 | else |
1bb98cec DM |
985 | qty_table[q].last_reg = new; |
986 | reg_eqv_table[lastr].next = new; | |
987 | reg_eqv_table[new].prev = lastr; | |
7afe21cc RK |
988 | } |
989 | } | |
990 | ||
991 | /* Remove REG from its equivalence class. */ | |
992 | ||
993 | static void | |
7080f735 | 994 | delete_reg_equiv (unsigned int reg) |
7afe21cc | 995 | { |
b3694847 SS |
996 | struct qty_table_elem *ent; |
997 | int q = REG_QTY (reg); | |
998 | int p, n; | |
7afe21cc | 999 | |
a4e262bc | 1000 | /* If invalid, do nothing. */ |
08a69267 | 1001 | if (! REGNO_QTY_VALID_P (reg)) |
7afe21cc RK |
1002 | return; |
1003 | ||
1bb98cec DM |
1004 | ent = &qty_table[q]; |
1005 | ||
1006 | p = reg_eqv_table[reg].prev; | |
1007 | n = reg_eqv_table[reg].next; | |
a4e262bc | 1008 | |
7afe21cc | 1009 | if (n != -1) |
1bb98cec | 1010 | reg_eqv_table[n].prev = p; |
7afe21cc | 1011 | else |
1bb98cec | 1012 | ent->last_reg = p; |
7afe21cc | 1013 | if (p != -1) |
1bb98cec | 1014 | reg_eqv_table[p].next = n; |
7afe21cc | 1015 | else |
1bb98cec | 1016 | ent->first_reg = n; |
7afe21cc | 1017 | |
08a69267 | 1018 | REG_QTY (reg) = -reg - 1; |
7afe21cc RK |
1019 | } |
1020 | ||
1021 | /* Remove any invalid expressions from the hash table | |
1022 | that refer to any of the registers contained in expression X. | |
1023 | ||
1024 | Make sure that newly inserted references to those registers | |
1025 | as subexpressions will be considered valid. | |
1026 | ||
1027 | mention_regs is not called when a register itself | |
1028 | is being stored in the table. | |
1029 | ||
1030 | Return 1 if we have done something that may have changed the hash code | |
1031 | of X. */ | |
1032 | ||
1033 | static int | |
7080f735 | 1034 | mention_regs (rtx x) |
7afe21cc | 1035 | { |
b3694847 SS |
1036 | enum rtx_code code; |
1037 | int i, j; | |
1038 | const char *fmt; | |
1039 | int changed = 0; | |
7afe21cc RK |
1040 | |
1041 | if (x == 0) | |
e5f6a288 | 1042 | return 0; |
7afe21cc RK |
1043 | |
1044 | code = GET_CODE (x); | |
1045 | if (code == REG) | |
1046 | { | |
770ae6cc RK |
1047 | unsigned int regno = REGNO (x); |
1048 | unsigned int endregno | |
7afe21cc | 1049 | = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1 |
66fd46b6 | 1050 | : hard_regno_nregs[regno][GET_MODE (x)]); |
770ae6cc | 1051 | unsigned int i; |
7afe21cc RK |
1052 | |
1053 | for (i = regno; i < endregno; i++) | |
1054 | { | |
30f72379 | 1055 | if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i)) |
7afe21cc RK |
1056 | remove_invalid_refs (i); |
1057 | ||
30f72379 | 1058 | REG_IN_TABLE (i) = REG_TICK (i); |
46081bb3 | 1059 | SUBREG_TICKED (i) = -1; |
7afe21cc RK |
1060 | } |
1061 | ||
1062 | return 0; | |
1063 | } | |
1064 | ||
34c73909 R |
1065 | /* If this is a SUBREG, we don't want to discard other SUBREGs of the same |
1066 | pseudo if they don't use overlapping words. We handle only pseudos | |
1067 | here for simplicity. */ | |
f8cfc6aa | 1068 | if (code == SUBREG && REG_P (SUBREG_REG (x)) |
34c73909 R |
1069 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER) |
1070 | { | |
770ae6cc | 1071 | unsigned int i = REGNO (SUBREG_REG (x)); |
34c73909 | 1072 | |
30f72379 | 1073 | if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i)) |
34c73909 | 1074 | { |
46081bb3 SH |
1075 | /* If REG_IN_TABLE (i) differs from REG_TICK (i) by one, and |
1076 | the last store to this register really stored into this | |
1077 | subreg, then remove the memory of this subreg. | |
1078 | Otherwise, remove any memory of the entire register and | |
1079 | all its subregs from the table. */ | |
1080 | if (REG_TICK (i) - REG_IN_TABLE (i) > 1 | |
5dd78e9a | 1081 | || SUBREG_TICKED (i) != REGNO (SUBREG_REG (x))) |
34c73909 R |
1082 | remove_invalid_refs (i); |
1083 | else | |
ddef6bc7 | 1084 | remove_invalid_subreg_refs (i, SUBREG_BYTE (x), GET_MODE (x)); |
34c73909 R |
1085 | } |
1086 | ||
30f72379 | 1087 | REG_IN_TABLE (i) = REG_TICK (i); |
5dd78e9a | 1088 | SUBREG_TICKED (i) = REGNO (SUBREG_REG (x)); |
34c73909 R |
1089 | return 0; |
1090 | } | |
1091 | ||
7afe21cc RK |
1092 | /* If X is a comparison or a COMPARE and either operand is a register |
1093 | that does not have a quantity, give it one. This is so that a later | |
1094 | call to record_jump_equiv won't cause X to be assigned a different | |
1095 | hash code and not found in the table after that call. | |
1096 | ||
1097 | It is not necessary to do this here, since rehash_using_reg can | |
1098 | fix up the table later, but doing this here eliminates the need to | |
1099 | call that expensive function in the most common case where the only | |
1100 | use of the register is in the comparison. */ | |
1101 | ||
ec8e098d | 1102 | if (code == COMPARE || COMPARISON_P (x)) |
7afe21cc | 1103 | { |
f8cfc6aa | 1104 | if (REG_P (XEXP (x, 0)) |
7afe21cc | 1105 | && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 0)))) |
9714cf43 | 1106 | if (insert_regs (XEXP (x, 0), NULL, 0)) |
7afe21cc RK |
1107 | { |
1108 | rehash_using_reg (XEXP (x, 0)); | |
1109 | changed = 1; | |
1110 | } | |
1111 | ||
f8cfc6aa | 1112 | if (REG_P (XEXP (x, 1)) |
7afe21cc | 1113 | && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 1)))) |
9714cf43 | 1114 | if (insert_regs (XEXP (x, 1), NULL, 0)) |
7afe21cc RK |
1115 | { |
1116 | rehash_using_reg (XEXP (x, 1)); | |
1117 | changed = 1; | |
1118 | } | |
1119 | } | |
1120 | ||
1121 | fmt = GET_RTX_FORMAT (code); | |
1122 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1123 | if (fmt[i] == 'e') | |
1124 | changed |= mention_regs (XEXP (x, i)); | |
1125 | else if (fmt[i] == 'E') | |
1126 | for (j = 0; j < XVECLEN (x, i); j++) | |
1127 | changed |= mention_regs (XVECEXP (x, i, j)); | |
1128 | ||
1129 | return changed; | |
1130 | } | |
1131 | ||
1132 | /* Update the register quantities for inserting X into the hash table | |
1133 | with a value equivalent to CLASSP. | |
1134 | (If the class does not contain a REG, it is irrelevant.) | |
1135 | If MODIFIED is nonzero, X is a destination; it is being modified. | |
1136 | Note that delete_reg_equiv should be called on a register | |
1137 | before insert_regs is done on that register with MODIFIED != 0. | |
1138 | ||
1139 | Nonzero value means that elements of reg_qty have changed | |
1140 | so X's hash code may be different. */ | |
1141 | ||
1142 | static int | |
7080f735 | 1143 | insert_regs (rtx x, struct table_elt *classp, int modified) |
7afe21cc | 1144 | { |
f8cfc6aa | 1145 | if (REG_P (x)) |
7afe21cc | 1146 | { |
770ae6cc RK |
1147 | unsigned int regno = REGNO (x); |
1148 | int qty_valid; | |
7afe21cc | 1149 | |
1ff0c00d RK |
1150 | /* If REGNO is in the equivalence table already but is of the |
1151 | wrong mode for that equivalence, don't do anything here. */ | |
1152 | ||
1bb98cec DM |
1153 | qty_valid = REGNO_QTY_VALID_P (regno); |
1154 | if (qty_valid) | |
1155 | { | |
1156 | struct qty_table_elem *ent = &qty_table[REG_QTY (regno)]; | |
1ff0c00d | 1157 | |
1bb98cec DM |
1158 | if (ent->mode != GET_MODE (x)) |
1159 | return 0; | |
1160 | } | |
1161 | ||
1162 | if (modified || ! qty_valid) | |
7afe21cc RK |
1163 | { |
1164 | if (classp) | |
1165 | for (classp = classp->first_same_value; | |
1166 | classp != 0; | |
1167 | classp = classp->next_same_value) | |
f8cfc6aa | 1168 | if (REG_P (classp->exp) |
7afe21cc RK |
1169 | && GET_MODE (classp->exp) == GET_MODE (x)) |
1170 | { | |
cd928652 ZD |
1171 | unsigned c_regno = REGNO (classp->exp); |
1172 | ||
1173 | gcc_assert (REGNO_QTY_VALID_P (c_regno)); | |
1174 | ||
1175 | /* Suppose that 5 is hard reg and 100 and 101 are | |
1176 | pseudos. Consider | |
1177 | ||
1178 | (set (reg:si 100) (reg:si 5)) | |
1179 | (set (reg:si 5) (reg:si 100)) | |
1180 | (set (reg:di 101) (reg:di 5)) | |
1181 | ||
1182 | We would now set REG_QTY (101) = REG_QTY (5), but the | |
1183 | entry for 5 is in SImode. When we use this later in | |
1184 | copy propagation, we get the register in wrong mode. */ | |
1185 | if (qty_table[REG_QTY (c_regno)].mode != GET_MODE (x)) | |
1186 | continue; | |
1187 | ||
1188 | make_regs_eqv (regno, c_regno); | |
7afe21cc RK |
1189 | return 1; |
1190 | } | |
1191 | ||
d9f20424 R |
1192 | /* Mention_regs for a SUBREG checks if REG_TICK is exactly one larger |
1193 | than REG_IN_TABLE to find out if there was only a single preceding | |
1194 | invalidation - for the SUBREG - or another one, which would be | |
1195 | for the full register. However, if we find here that REG_TICK | |
1196 | indicates that the register is invalid, it means that it has | |
1197 | been invalidated in a separate operation. The SUBREG might be used | |
1198 | now (then this is a recursive call), or we might use the full REG | |
1199 | now and a SUBREG of it later. So bump up REG_TICK so that | |
1200 | mention_regs will do the right thing. */ | |
1201 | if (! modified | |
1202 | && REG_IN_TABLE (regno) >= 0 | |
1203 | && REG_TICK (regno) == REG_IN_TABLE (regno) + 1) | |
1204 | REG_TICK (regno)++; | |
1bb98cec | 1205 | make_new_qty (regno, GET_MODE (x)); |
7afe21cc RK |
1206 | return 1; |
1207 | } | |
cdf4112f TG |
1208 | |
1209 | return 0; | |
7afe21cc | 1210 | } |
c610adec RK |
1211 | |
1212 | /* If X is a SUBREG, we will likely be inserting the inner register in the | |
1213 | table. If that register doesn't have an assigned quantity number at | |
1214 | this point but does later, the insertion that we will be doing now will | |
1215 | not be accessible because its hash code will have changed. So assign | |
1216 | a quantity number now. */ | |
1217 | ||
f8cfc6aa | 1218 | else if (GET_CODE (x) == SUBREG && REG_P (SUBREG_REG (x)) |
c610adec RK |
1219 | && ! REGNO_QTY_VALID_P (REGNO (SUBREG_REG (x)))) |
1220 | { | |
9714cf43 | 1221 | insert_regs (SUBREG_REG (x), NULL, 0); |
34c73909 | 1222 | mention_regs (x); |
c610adec RK |
1223 | return 1; |
1224 | } | |
7afe21cc RK |
1225 | else |
1226 | return mention_regs (x); | |
1227 | } | |
1228 | \f | |
1229 | /* Look in or update the hash table. */ | |
1230 | ||
7afe21cc RK |
1231 | /* Remove table element ELT from use in the table. |
1232 | HASH is its hash code, made using the HASH macro. | |
1233 | It's an argument because often that is known in advance | |
1234 | and we save much time not recomputing it. */ | |
1235 | ||
1236 | static void | |
7080f735 | 1237 | remove_from_table (struct table_elt *elt, unsigned int hash) |
7afe21cc RK |
1238 | { |
1239 | if (elt == 0) | |
1240 | return; | |
1241 | ||
1242 | /* Mark this element as removed. See cse_insn. */ | |
1243 | elt->first_same_value = 0; | |
1244 | ||
1245 | /* Remove the table element from its equivalence class. */ | |
278a83b2 | 1246 | |
7afe21cc | 1247 | { |
b3694847 SS |
1248 | struct table_elt *prev = elt->prev_same_value; |
1249 | struct table_elt *next = elt->next_same_value; | |
7afe21cc | 1250 | |
278a83b2 KH |
1251 | if (next) |
1252 | next->prev_same_value = prev; | |
7afe21cc RK |
1253 | |
1254 | if (prev) | |
1255 | prev->next_same_value = next; | |
1256 | else | |
1257 | { | |
b3694847 | 1258 | struct table_elt *newfirst = next; |
7afe21cc RK |
1259 | while (next) |
1260 | { | |
1261 | next->first_same_value = newfirst; | |
1262 | next = next->next_same_value; | |
1263 | } | |
1264 | } | |
1265 | } | |
1266 | ||
1267 | /* Remove the table element from its hash bucket. */ | |
1268 | ||
1269 | { | |
b3694847 SS |
1270 | struct table_elt *prev = elt->prev_same_hash; |
1271 | struct table_elt *next = elt->next_same_hash; | |
7afe21cc | 1272 | |
278a83b2 KH |
1273 | if (next) |
1274 | next->prev_same_hash = prev; | |
7afe21cc RK |
1275 | |
1276 | if (prev) | |
1277 | prev->next_same_hash = next; | |
1278 | else if (table[hash] == elt) | |
1279 | table[hash] = next; | |
1280 | else | |
1281 | { | |
1282 | /* This entry is not in the proper hash bucket. This can happen | |
1283 | when two classes were merged by `merge_equiv_classes'. Search | |
1284 | for the hash bucket that it heads. This happens only very | |
1285 | rarely, so the cost is acceptable. */ | |
9b1549b8 | 1286 | for (hash = 0; hash < HASH_SIZE; hash++) |
7afe21cc RK |
1287 | if (table[hash] == elt) |
1288 | table[hash] = next; | |
1289 | } | |
1290 | } | |
1291 | ||
1292 | /* Remove the table element from its related-value circular chain. */ | |
1293 | ||
1294 | if (elt->related_value != 0 && elt->related_value != elt) | |
1295 | { | |
b3694847 | 1296 | struct table_elt *p = elt->related_value; |
770ae6cc | 1297 | |
7afe21cc RK |
1298 | while (p->related_value != elt) |
1299 | p = p->related_value; | |
1300 | p->related_value = elt->related_value; | |
1301 | if (p->related_value == p) | |
1302 | p->related_value = 0; | |
1303 | } | |
1304 | ||
9b1549b8 DM |
1305 | /* Now add it to the free element chain. */ |
1306 | elt->next_same_hash = free_element_chain; | |
1307 | free_element_chain = elt; | |
7afe21cc RK |
1308 | } |
1309 | ||
1310 | /* Look up X in the hash table and return its table element, | |
1311 | or 0 if X is not in the table. | |
1312 | ||
1313 | MODE is the machine-mode of X, or if X is an integer constant | |
1314 | with VOIDmode then MODE is the mode with which X will be used. | |
1315 | ||
1316 | Here we are satisfied to find an expression whose tree structure | |
1317 | looks like X. */ | |
1318 | ||
1319 | static struct table_elt * | |
7080f735 | 1320 | lookup (rtx x, unsigned int hash, enum machine_mode mode) |
7afe21cc | 1321 | { |
b3694847 | 1322 | struct table_elt *p; |
7afe21cc RK |
1323 | |
1324 | for (p = table[hash]; p; p = p->next_same_hash) | |
f8cfc6aa | 1325 | if (mode == p->mode && ((x == p->exp && REG_P (x)) |
0516f6fe | 1326 | || exp_equiv_p (x, p->exp, !REG_P (x), false))) |
7afe21cc RK |
1327 | return p; |
1328 | ||
1329 | return 0; | |
1330 | } | |
1331 | ||
1332 | /* Like `lookup' but don't care whether the table element uses invalid regs. | |
1333 | Also ignore discrepancies in the machine mode of a register. */ | |
1334 | ||
1335 | static struct table_elt * | |
7080f735 | 1336 | lookup_for_remove (rtx x, unsigned int hash, enum machine_mode mode) |
7afe21cc | 1337 | { |
b3694847 | 1338 | struct table_elt *p; |
7afe21cc | 1339 | |
f8cfc6aa | 1340 | if (REG_P (x)) |
7afe21cc | 1341 | { |
770ae6cc RK |
1342 | unsigned int regno = REGNO (x); |
1343 | ||
7afe21cc RK |
1344 | /* Don't check the machine mode when comparing registers; |
1345 | invalidating (REG:SI 0) also invalidates (REG:DF 0). */ | |
1346 | for (p = table[hash]; p; p = p->next_same_hash) | |
f8cfc6aa | 1347 | if (REG_P (p->exp) |
7afe21cc RK |
1348 | && REGNO (p->exp) == regno) |
1349 | return p; | |
1350 | } | |
1351 | else | |
1352 | { | |
1353 | for (p = table[hash]; p; p = p->next_same_hash) | |
0516f6fe SB |
1354 | if (mode == p->mode |
1355 | && (x == p->exp || exp_equiv_p (x, p->exp, 0, false))) | |
7afe21cc RK |
1356 | return p; |
1357 | } | |
1358 | ||
1359 | return 0; | |
1360 | } | |
1361 | ||
1362 | /* Look for an expression equivalent to X and with code CODE. | |
1363 | If one is found, return that expression. */ | |
1364 | ||
1365 | static rtx | |
7080f735 | 1366 | lookup_as_function (rtx x, enum rtx_code code) |
7afe21cc | 1367 | { |
b3694847 | 1368 | struct table_elt *p |
0516f6fe | 1369 | = lookup (x, SAFE_HASH (x, VOIDmode), GET_MODE (x)); |
770ae6cc | 1370 | |
34c73909 R |
1371 | /* If we are looking for a CONST_INT, the mode doesn't really matter, as |
1372 | long as we are narrowing. So if we looked in vain for a mode narrower | |
1373 | than word_mode before, look for word_mode now. */ | |
1374 | if (p == 0 && code == CONST_INT | |
1375 | && GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (word_mode)) | |
1376 | { | |
1377 | x = copy_rtx (x); | |
1378 | PUT_MODE (x, word_mode); | |
0516f6fe | 1379 | p = lookup (x, SAFE_HASH (x, VOIDmode), word_mode); |
34c73909 R |
1380 | } |
1381 | ||
7afe21cc RK |
1382 | if (p == 0) |
1383 | return 0; | |
1384 | ||
1385 | for (p = p->first_same_value; p; p = p->next_same_value) | |
770ae6cc RK |
1386 | if (GET_CODE (p->exp) == code |
1387 | /* Make sure this is a valid entry in the table. */ | |
0516f6fe | 1388 | && exp_equiv_p (p->exp, p->exp, 1, false)) |
770ae6cc | 1389 | return p->exp; |
278a83b2 | 1390 | |
7afe21cc RK |
1391 | return 0; |
1392 | } | |
1393 | ||
1394 | /* Insert X in the hash table, assuming HASH is its hash code | |
1395 | and CLASSP is an element of the class it should go in | |
1396 | (or 0 if a new class should be made). | |
1397 | It is inserted at the proper position to keep the class in | |
1398 | the order cheapest first. | |
1399 | ||
1400 | MODE is the machine-mode of X, or if X is an integer constant | |
1401 | with VOIDmode then MODE is the mode with which X will be used. | |
1402 | ||
1403 | For elements of equal cheapness, the most recent one | |
1404 | goes in front, except that the first element in the list | |
1405 | remains first unless a cheaper element is added. The order of | |
1406 | pseudo-registers does not matter, as canon_reg will be called to | |
830a38ee | 1407 | find the cheapest when a register is retrieved from the table. |
7afe21cc RK |
1408 | |
1409 | The in_memory field in the hash table element is set to 0. | |
1410 | The caller must set it nonzero if appropriate. | |
1411 | ||
1412 | You should call insert_regs (X, CLASSP, MODIFY) before calling here, | |
1413 | and if insert_regs returns a nonzero value | |
1414 | you must then recompute its hash code before calling here. | |
1415 | ||
1416 | If necessary, update table showing constant values of quantities. */ | |
1417 | ||
630c79be | 1418 | #define CHEAPER(X, Y) \ |
56ae04af | 1419 | (preferable ((X)->cost, (X)->regcost, (Y)->cost, (Y)->regcost) < 0) |
7afe21cc RK |
1420 | |
1421 | static struct table_elt * | |
7080f735 | 1422 | insert (rtx x, struct table_elt *classp, unsigned int hash, enum machine_mode mode) |
7afe21cc | 1423 | { |
b3694847 | 1424 | struct table_elt *elt; |
7afe21cc RK |
1425 | |
1426 | /* If X is a register and we haven't made a quantity for it, | |
1427 | something is wrong. */ | |
341c100f | 1428 | gcc_assert (!REG_P (x) || REGNO_QTY_VALID_P (REGNO (x))); |
7afe21cc RK |
1429 | |
1430 | /* If X is a hard register, show it is being put in the table. */ | |
f8cfc6aa | 1431 | if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER) |
7afe21cc | 1432 | { |
770ae6cc | 1433 | unsigned int regno = REGNO (x); |
66fd46b6 | 1434 | unsigned int endregno = regno + hard_regno_nregs[regno][GET_MODE (x)]; |
770ae6cc | 1435 | unsigned int i; |
7afe21cc RK |
1436 | |
1437 | for (i = regno; i < endregno; i++) | |
770ae6cc | 1438 | SET_HARD_REG_BIT (hard_regs_in_table, i); |
7afe21cc RK |
1439 | } |
1440 | ||
7afe21cc RK |
1441 | /* Put an element for X into the right hash bucket. */ |
1442 | ||
9b1549b8 DM |
1443 | elt = free_element_chain; |
1444 | if (elt) | |
770ae6cc | 1445 | free_element_chain = elt->next_same_hash; |
9b1549b8 | 1446 | else |
5ed6ace5 | 1447 | elt = XNEW (struct table_elt); |
9b1549b8 | 1448 | |
7afe21cc | 1449 | elt->exp = x; |
db048faf | 1450 | elt->canon_exp = NULL_RTX; |
7afe21cc | 1451 | elt->cost = COST (x); |
630c79be | 1452 | elt->regcost = approx_reg_cost (x); |
7afe21cc RK |
1453 | elt->next_same_value = 0; |
1454 | elt->prev_same_value = 0; | |
1455 | elt->next_same_hash = table[hash]; | |
1456 | elt->prev_same_hash = 0; | |
1457 | elt->related_value = 0; | |
1458 | elt->in_memory = 0; | |
1459 | elt->mode = mode; | |
389fdba0 | 1460 | elt->is_const = (CONSTANT_P (x) || fixed_base_plus_p (x)); |
7afe21cc RK |
1461 | |
1462 | if (table[hash]) | |
1463 | table[hash]->prev_same_hash = elt; | |
1464 | table[hash] = elt; | |
1465 | ||
1466 | /* Put it into the proper value-class. */ | |
1467 | if (classp) | |
1468 | { | |
1469 | classp = classp->first_same_value; | |
1470 | if (CHEAPER (elt, classp)) | |
f9da5064 | 1471 | /* Insert at the head of the class. */ |
7afe21cc | 1472 | { |
b3694847 | 1473 | struct table_elt *p; |
7afe21cc RK |
1474 | elt->next_same_value = classp; |
1475 | classp->prev_same_value = elt; | |
1476 | elt->first_same_value = elt; | |
1477 | ||
1478 | for (p = classp; p; p = p->next_same_value) | |
1479 | p->first_same_value = elt; | |
1480 | } | |
1481 | else | |
1482 | { | |
1483 | /* Insert not at head of the class. */ | |
1484 | /* Put it after the last element cheaper than X. */ | |
b3694847 | 1485 | struct table_elt *p, *next; |
770ae6cc | 1486 | |
7afe21cc RK |
1487 | for (p = classp; (next = p->next_same_value) && CHEAPER (next, elt); |
1488 | p = next); | |
770ae6cc | 1489 | |
7afe21cc RK |
1490 | /* Put it after P and before NEXT. */ |
1491 | elt->next_same_value = next; | |
1492 | if (next) | |
1493 | next->prev_same_value = elt; | |
770ae6cc | 1494 | |
7afe21cc RK |
1495 | elt->prev_same_value = p; |
1496 | p->next_same_value = elt; | |
1497 | elt->first_same_value = classp; | |
1498 | } | |
1499 | } | |
1500 | else | |
1501 | elt->first_same_value = elt; | |
1502 | ||
1503 | /* If this is a constant being set equivalent to a register or a register | |
1504 | being set equivalent to a constant, note the constant equivalence. | |
1505 | ||
1506 | If this is a constant, it cannot be equivalent to a different constant, | |
1507 | and a constant is the only thing that can be cheaper than a register. So | |
1508 | we know the register is the head of the class (before the constant was | |
1509 | inserted). | |
1510 | ||
1511 | If this is a register that is not already known equivalent to a | |
1512 | constant, we must check the entire class. | |
1513 | ||
1514 | If this is a register that is already known equivalent to an insn, | |
1bb98cec | 1515 | update the qtys `const_insn' to show that `this_insn' is the latest |
7afe21cc RK |
1516 | insn making that quantity equivalent to the constant. */ |
1517 | ||
f8cfc6aa JQ |
1518 | if (elt->is_const && classp && REG_P (classp->exp) |
1519 | && !REG_P (x)) | |
7afe21cc | 1520 | { |
1bb98cec DM |
1521 | int exp_q = REG_QTY (REGNO (classp->exp)); |
1522 | struct qty_table_elem *exp_ent = &qty_table[exp_q]; | |
1523 | ||
4de249d9 | 1524 | exp_ent->const_rtx = gen_lowpart (exp_ent->mode, x); |
1bb98cec | 1525 | exp_ent->const_insn = this_insn; |
7afe21cc RK |
1526 | } |
1527 | ||
f8cfc6aa | 1528 | else if (REG_P (x) |
1bb98cec DM |
1529 | && classp |
1530 | && ! qty_table[REG_QTY (REGNO (x))].const_rtx | |
f353588a | 1531 | && ! elt->is_const) |
7afe21cc | 1532 | { |
b3694847 | 1533 | struct table_elt *p; |
7afe21cc RK |
1534 | |
1535 | for (p = classp; p != 0; p = p->next_same_value) | |
1536 | { | |
f8cfc6aa | 1537 | if (p->is_const && !REG_P (p->exp)) |
7afe21cc | 1538 | { |
1bb98cec DM |
1539 | int x_q = REG_QTY (REGNO (x)); |
1540 | struct qty_table_elem *x_ent = &qty_table[x_q]; | |
1541 | ||
770ae6cc | 1542 | x_ent->const_rtx |
4de249d9 | 1543 | = gen_lowpart (GET_MODE (x), p->exp); |
1bb98cec | 1544 | x_ent->const_insn = this_insn; |
7afe21cc RK |
1545 | break; |
1546 | } | |
1547 | } | |
1548 | } | |
1549 | ||
f8cfc6aa | 1550 | else if (REG_P (x) |
1bb98cec DM |
1551 | && qty_table[REG_QTY (REGNO (x))].const_rtx |
1552 | && GET_MODE (x) == qty_table[REG_QTY (REGNO (x))].mode) | |
1553 | qty_table[REG_QTY (REGNO (x))].const_insn = this_insn; | |
7afe21cc RK |
1554 | |
1555 | /* If this is a constant with symbolic value, | |
1556 | and it has a term with an explicit integer value, | |
1557 | link it up with related expressions. */ | |
1558 | if (GET_CODE (x) == CONST) | |
1559 | { | |
1560 | rtx subexp = get_related_value (x); | |
2197a88a | 1561 | unsigned subhash; |
7afe21cc RK |
1562 | struct table_elt *subelt, *subelt_prev; |
1563 | ||
1564 | if (subexp != 0) | |
1565 | { | |
1566 | /* Get the integer-free subexpression in the hash table. */ | |
0516f6fe | 1567 | subhash = SAFE_HASH (subexp, mode); |
7afe21cc RK |
1568 | subelt = lookup (subexp, subhash, mode); |
1569 | if (subelt == 0) | |
9714cf43 | 1570 | subelt = insert (subexp, NULL, subhash, mode); |
7afe21cc RK |
1571 | /* Initialize SUBELT's circular chain if it has none. */ |
1572 | if (subelt->related_value == 0) | |
1573 | subelt->related_value = subelt; | |
1574 | /* Find the element in the circular chain that precedes SUBELT. */ | |
1575 | subelt_prev = subelt; | |
1576 | while (subelt_prev->related_value != subelt) | |
1577 | subelt_prev = subelt_prev->related_value; | |
1578 | /* Put new ELT into SUBELT's circular chain just before SUBELT. | |
1579 | This way the element that follows SUBELT is the oldest one. */ | |
1580 | elt->related_value = subelt_prev->related_value; | |
1581 | subelt_prev->related_value = elt; | |
1582 | } | |
1583 | } | |
1584 | ||
1585 | return elt; | |
1586 | } | |
1587 | \f | |
1588 | /* Given two equivalence classes, CLASS1 and CLASS2, put all the entries from | |
1589 | CLASS2 into CLASS1. This is done when we have reached an insn which makes | |
1590 | the two classes equivalent. | |
1591 | ||
1592 | CLASS1 will be the surviving class; CLASS2 should not be used after this | |
1593 | call. | |
1594 | ||
1595 | Any invalid entries in CLASS2 will not be copied. */ | |
1596 | ||
1597 | static void | |
7080f735 | 1598 | merge_equiv_classes (struct table_elt *class1, struct table_elt *class2) |
7afe21cc RK |
1599 | { |
1600 | struct table_elt *elt, *next, *new; | |
1601 | ||
1602 | /* Ensure we start with the head of the classes. */ | |
1603 | class1 = class1->first_same_value; | |
1604 | class2 = class2->first_same_value; | |
1605 | ||
1606 | /* If they were already equal, forget it. */ | |
1607 | if (class1 == class2) | |
1608 | return; | |
1609 | ||
1610 | for (elt = class2; elt; elt = next) | |
1611 | { | |
770ae6cc | 1612 | unsigned int hash; |
7afe21cc RK |
1613 | rtx exp = elt->exp; |
1614 | enum machine_mode mode = elt->mode; | |
1615 | ||
1616 | next = elt->next_same_value; | |
1617 | ||
1618 | /* Remove old entry, make a new one in CLASS1's class. | |
1619 | Don't do this for invalid entries as we cannot find their | |
0f41302f | 1620 | hash code (it also isn't necessary). */ |
0516f6fe | 1621 | if (REG_P (exp) || exp_equiv_p (exp, exp, 1, false)) |
7afe21cc | 1622 | { |
a90fc8e0 RH |
1623 | bool need_rehash = false; |
1624 | ||
7afe21cc | 1625 | hash_arg_in_memory = 0; |
7afe21cc | 1626 | hash = HASH (exp, mode); |
278a83b2 | 1627 | |
f8cfc6aa | 1628 | if (REG_P (exp)) |
a90fc8e0 | 1629 | { |
08a69267 | 1630 | need_rehash = REGNO_QTY_VALID_P (REGNO (exp)); |
a90fc8e0 RH |
1631 | delete_reg_equiv (REGNO (exp)); |
1632 | } | |
278a83b2 | 1633 | |
7afe21cc RK |
1634 | remove_from_table (elt, hash); |
1635 | ||
a90fc8e0 | 1636 | if (insert_regs (exp, class1, 0) || need_rehash) |
8ae2b8f6 JW |
1637 | { |
1638 | rehash_using_reg (exp); | |
1639 | hash = HASH (exp, mode); | |
1640 | } | |
7afe21cc RK |
1641 | new = insert (exp, class1, hash, mode); |
1642 | new->in_memory = hash_arg_in_memory; | |
7afe21cc RK |
1643 | } |
1644 | } | |
1645 | } | |
1646 | \f | |
01e752d3 JL |
1647 | /* Flush the entire hash table. */ |
1648 | ||
1649 | static void | |
7080f735 | 1650 | flush_hash_table (void) |
01e752d3 JL |
1651 | { |
1652 | int i; | |
1653 | struct table_elt *p; | |
1654 | ||
9b1549b8 | 1655 | for (i = 0; i < HASH_SIZE; i++) |
01e752d3 JL |
1656 | for (p = table[i]; p; p = table[i]) |
1657 | { | |
1658 | /* Note that invalidate can remove elements | |
1659 | after P in the current hash chain. */ | |
f8cfc6aa | 1660 | if (REG_P (p->exp)) |
524e3576 | 1661 | invalidate (p->exp, VOIDmode); |
01e752d3 JL |
1662 | else |
1663 | remove_from_table (p, i); | |
1664 | } | |
1665 | } | |
14a774a9 | 1666 | \f |
2ce6dc2f JH |
1667 | /* Function called for each rtx to check whether true dependence exist. */ |
1668 | struct check_dependence_data | |
1669 | { | |
1670 | enum machine_mode mode; | |
1671 | rtx exp; | |
9ddb66ca | 1672 | rtx addr; |
2ce6dc2f | 1673 | }; |
be8ac49a | 1674 | |
2ce6dc2f | 1675 | static int |
7080f735 | 1676 | check_dependence (rtx *x, void *data) |
2ce6dc2f JH |
1677 | { |
1678 | struct check_dependence_data *d = (struct check_dependence_data *) data; | |
3c0cb5de | 1679 | if (*x && MEM_P (*x)) |
9ddb66ca JH |
1680 | return canon_true_dependence (d->exp, d->mode, d->addr, *x, |
1681 | cse_rtx_varies_p); | |
2ce6dc2f JH |
1682 | else |
1683 | return 0; | |
1684 | } | |
1685 | \f | |
14a774a9 RK |
1686 | /* Remove from the hash table, or mark as invalid, all expressions whose |
1687 | values could be altered by storing in X. X is a register, a subreg, or | |
1688 | a memory reference with nonvarying address (because, when a memory | |
1689 | reference with a varying address is stored in, all memory references are | |
1690 | removed by invalidate_memory so specific invalidation is superfluous). | |
1691 | FULL_MODE, if not VOIDmode, indicates that this much should be | |
1692 | invalidated instead of just the amount indicated by the mode of X. This | |
1693 | is only used for bitfield stores into memory. | |
1694 | ||
1695 | A nonvarying address may be just a register or just a symbol reference, | |
1696 | or it may be either of those plus a numeric offset. */ | |
7afe21cc RK |
1697 | |
1698 | static void | |
7080f735 | 1699 | invalidate (rtx x, enum machine_mode full_mode) |
7afe21cc | 1700 | { |
b3694847 SS |
1701 | int i; |
1702 | struct table_elt *p; | |
9ddb66ca | 1703 | rtx addr; |
7afe21cc | 1704 | |
14a774a9 | 1705 | switch (GET_CODE (x)) |
7afe21cc | 1706 | { |
14a774a9 RK |
1707 | case REG: |
1708 | { | |
1709 | /* If X is a register, dependencies on its contents are recorded | |
1710 | through the qty number mechanism. Just change the qty number of | |
1711 | the register, mark it as invalid for expressions that refer to it, | |
1712 | and remove it itself. */ | |
770ae6cc RK |
1713 | unsigned int regno = REGNO (x); |
1714 | unsigned int hash = HASH (x, GET_MODE (x)); | |
7afe21cc | 1715 | |
14a774a9 RK |
1716 | /* Remove REGNO from any quantity list it might be on and indicate |
1717 | that its value might have changed. If it is a pseudo, remove its | |
1718 | entry from the hash table. | |
7afe21cc | 1719 | |
14a774a9 RK |
1720 | For a hard register, we do the first two actions above for any |
1721 | additional hard registers corresponding to X. Then, if any of these | |
1722 | registers are in the table, we must remove any REG entries that | |
1723 | overlap these registers. */ | |
7afe21cc | 1724 | |
14a774a9 RK |
1725 | delete_reg_equiv (regno); |
1726 | REG_TICK (regno)++; | |
46081bb3 | 1727 | SUBREG_TICKED (regno) = -1; |
85e4d983 | 1728 | |
14a774a9 RK |
1729 | if (regno >= FIRST_PSEUDO_REGISTER) |
1730 | { | |
1731 | /* Because a register can be referenced in more than one mode, | |
1732 | we might have to remove more than one table entry. */ | |
1733 | struct table_elt *elt; | |
85e4d983 | 1734 | |
14a774a9 RK |
1735 | while ((elt = lookup_for_remove (x, hash, GET_MODE (x)))) |
1736 | remove_from_table (elt, hash); | |
1737 | } | |
1738 | else | |
1739 | { | |
1740 | HOST_WIDE_INT in_table | |
1741 | = TEST_HARD_REG_BIT (hard_regs_in_table, regno); | |
770ae6cc | 1742 | unsigned int endregno |
66fd46b6 | 1743 | = regno + hard_regno_nregs[regno][GET_MODE (x)]; |
770ae6cc | 1744 | unsigned int tregno, tendregno, rn; |
b3694847 | 1745 | struct table_elt *p, *next; |
7afe21cc | 1746 | |
14a774a9 | 1747 | CLEAR_HARD_REG_BIT (hard_regs_in_table, regno); |
7afe21cc | 1748 | |
770ae6cc | 1749 | for (rn = regno + 1; rn < endregno; rn++) |
14a774a9 | 1750 | { |
770ae6cc RK |
1751 | in_table |= TEST_HARD_REG_BIT (hard_regs_in_table, rn); |
1752 | CLEAR_HARD_REG_BIT (hard_regs_in_table, rn); | |
1753 | delete_reg_equiv (rn); | |
1754 | REG_TICK (rn)++; | |
46081bb3 | 1755 | SUBREG_TICKED (rn) = -1; |
14a774a9 | 1756 | } |
7afe21cc | 1757 | |
14a774a9 | 1758 | if (in_table) |
9b1549b8 | 1759 | for (hash = 0; hash < HASH_SIZE; hash++) |
14a774a9 RK |
1760 | for (p = table[hash]; p; p = next) |
1761 | { | |
1762 | next = p->next_same_hash; | |
7afe21cc | 1763 | |
f8cfc6aa | 1764 | if (!REG_P (p->exp) |
278a83b2 KH |
1765 | || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) |
1766 | continue; | |
1767 | ||
14a774a9 RK |
1768 | tregno = REGNO (p->exp); |
1769 | tendregno | |
66fd46b6 | 1770 | = tregno + hard_regno_nregs[tregno][GET_MODE (p->exp)]; |
14a774a9 RK |
1771 | if (tendregno > regno && tregno < endregno) |
1772 | remove_from_table (p, hash); | |
1773 | } | |
1774 | } | |
1775 | } | |
7afe21cc | 1776 | return; |
7afe21cc | 1777 | |
14a774a9 | 1778 | case SUBREG: |
bb4034b3 | 1779 | invalidate (SUBREG_REG (x), VOIDmode); |
7afe21cc | 1780 | return; |
aac5cc16 | 1781 | |
14a774a9 | 1782 | case PARALLEL: |
278a83b2 | 1783 | for (i = XVECLEN (x, 0) - 1; i >= 0; --i) |
aac5cc16 RH |
1784 | invalidate (XVECEXP (x, 0, i), VOIDmode); |
1785 | return; | |
aac5cc16 | 1786 | |
14a774a9 RK |
1787 | case EXPR_LIST: |
1788 | /* This is part of a disjoint return value; extract the location in | |
1789 | question ignoring the offset. */ | |
aac5cc16 RH |
1790 | invalidate (XEXP (x, 0), VOIDmode); |
1791 | return; | |
7afe21cc | 1792 | |
14a774a9 | 1793 | case MEM: |
9ddb66ca | 1794 | addr = canon_rtx (get_addr (XEXP (x, 0))); |
db048faf MM |
1795 | /* Calculate the canonical version of X here so that |
1796 | true_dependence doesn't generate new RTL for X on each call. */ | |
1797 | x = canon_rtx (x); | |
1798 | ||
14a774a9 RK |
1799 | /* Remove all hash table elements that refer to overlapping pieces of |
1800 | memory. */ | |
1801 | if (full_mode == VOIDmode) | |
1802 | full_mode = GET_MODE (x); | |
bb4034b3 | 1803 | |
9b1549b8 | 1804 | for (i = 0; i < HASH_SIZE; i++) |
7afe21cc | 1805 | { |
b3694847 | 1806 | struct table_elt *next; |
14a774a9 RK |
1807 | |
1808 | for (p = table[i]; p; p = next) | |
1809 | { | |
1810 | next = p->next_same_hash; | |
db048faf MM |
1811 | if (p->in_memory) |
1812 | { | |
2ce6dc2f JH |
1813 | struct check_dependence_data d; |
1814 | ||
1815 | /* Just canonicalize the expression once; | |
1816 | otherwise each time we call invalidate | |
1817 | true_dependence will canonicalize the | |
1818 | expression again. */ | |
1819 | if (!p->canon_exp) | |
1820 | p->canon_exp = canon_rtx (p->exp); | |
1821 | d.exp = x; | |
9ddb66ca | 1822 | d.addr = addr; |
2ce6dc2f JH |
1823 | d.mode = full_mode; |
1824 | if (for_each_rtx (&p->canon_exp, check_dependence, &d)) | |
db048faf | 1825 | remove_from_table (p, i); |
db048faf | 1826 | } |
14a774a9 | 1827 | } |
7afe21cc | 1828 | } |
14a774a9 RK |
1829 | return; |
1830 | ||
1831 | default: | |
341c100f | 1832 | gcc_unreachable (); |
7afe21cc RK |
1833 | } |
1834 | } | |
14a774a9 | 1835 | \f |
7afe21cc RK |
1836 | /* Remove all expressions that refer to register REGNO, |
1837 | since they are already invalid, and we are about to | |
1838 | mark that register valid again and don't want the old | |
1839 | expressions to reappear as valid. */ | |
1840 | ||
1841 | static void | |
7080f735 | 1842 | remove_invalid_refs (unsigned int regno) |
7afe21cc | 1843 | { |
770ae6cc RK |
1844 | unsigned int i; |
1845 | struct table_elt *p, *next; | |
7afe21cc | 1846 | |
9b1549b8 | 1847 | for (i = 0; i < HASH_SIZE; i++) |
7afe21cc RK |
1848 | for (p = table[i]; p; p = next) |
1849 | { | |
1850 | next = p->next_same_hash; | |
f8cfc6aa | 1851 | if (!REG_P (p->exp) |
68252e27 | 1852 | && refers_to_regno_p (regno, regno + 1, p->exp, (rtx *) 0)) |
7afe21cc RK |
1853 | remove_from_table (p, i); |
1854 | } | |
1855 | } | |
34c73909 | 1856 | |
ddef6bc7 JJ |
1857 | /* Likewise for a subreg with subreg_reg REGNO, subreg_byte OFFSET, |
1858 | and mode MODE. */ | |
34c73909 | 1859 | static void |
7080f735 AJ |
1860 | remove_invalid_subreg_refs (unsigned int regno, unsigned int offset, |
1861 | enum machine_mode mode) | |
34c73909 | 1862 | { |
770ae6cc RK |
1863 | unsigned int i; |
1864 | struct table_elt *p, *next; | |
ddef6bc7 | 1865 | unsigned int end = offset + (GET_MODE_SIZE (mode) - 1); |
34c73909 | 1866 | |
9b1549b8 | 1867 | for (i = 0; i < HASH_SIZE; i++) |
34c73909 R |
1868 | for (p = table[i]; p; p = next) |
1869 | { | |
ddef6bc7 | 1870 | rtx exp = p->exp; |
34c73909 | 1871 | next = p->next_same_hash; |
278a83b2 | 1872 | |
f8cfc6aa | 1873 | if (!REG_P (exp) |
34c73909 | 1874 | && (GET_CODE (exp) != SUBREG |
f8cfc6aa | 1875 | || !REG_P (SUBREG_REG (exp)) |
34c73909 | 1876 | || REGNO (SUBREG_REG (exp)) != regno |
ddef6bc7 JJ |
1877 | || (((SUBREG_BYTE (exp) |
1878 | + (GET_MODE_SIZE (GET_MODE (exp)) - 1)) >= offset) | |
1879 | && SUBREG_BYTE (exp) <= end)) | |
68252e27 | 1880 | && refers_to_regno_p (regno, regno + 1, p->exp, (rtx *) 0)) |
34c73909 R |
1881 | remove_from_table (p, i); |
1882 | } | |
1883 | } | |
7afe21cc RK |
1884 | \f |
1885 | /* Recompute the hash codes of any valid entries in the hash table that | |
1886 | reference X, if X is a register, or SUBREG_REG (X) if X is a SUBREG. | |
1887 | ||
1888 | This is called when we make a jump equivalence. */ | |
1889 | ||
1890 | static void | |
7080f735 | 1891 | rehash_using_reg (rtx x) |
7afe21cc | 1892 | { |
973838fd | 1893 | unsigned int i; |
7afe21cc | 1894 | struct table_elt *p, *next; |
2197a88a | 1895 | unsigned hash; |
7afe21cc RK |
1896 | |
1897 | if (GET_CODE (x) == SUBREG) | |
1898 | x = SUBREG_REG (x); | |
1899 | ||
1900 | /* If X is not a register or if the register is known not to be in any | |
1901 | valid entries in the table, we have no work to do. */ | |
1902 | ||
f8cfc6aa | 1903 | if (!REG_P (x) |
30f72379 MM |
1904 | || REG_IN_TABLE (REGNO (x)) < 0 |
1905 | || REG_IN_TABLE (REGNO (x)) != REG_TICK (REGNO (x))) | |
7afe21cc RK |
1906 | return; |
1907 | ||
1908 | /* Scan all hash chains looking for valid entries that mention X. | |
a90fc8e0 | 1909 | If we find one and it is in the wrong hash chain, move it. */ |
7afe21cc | 1910 | |
9b1549b8 | 1911 | for (i = 0; i < HASH_SIZE; i++) |
7afe21cc RK |
1912 | for (p = table[i]; p; p = next) |
1913 | { | |
1914 | next = p->next_same_hash; | |
a90fc8e0 | 1915 | if (reg_mentioned_p (x, p->exp) |
0516f6fe SB |
1916 | && exp_equiv_p (p->exp, p->exp, 1, false) |
1917 | && i != (hash = SAFE_HASH (p->exp, p->mode))) | |
7afe21cc RK |
1918 | { |
1919 | if (p->next_same_hash) | |
1920 | p->next_same_hash->prev_same_hash = p->prev_same_hash; | |
1921 | ||
1922 | if (p->prev_same_hash) | |
1923 | p->prev_same_hash->next_same_hash = p->next_same_hash; | |
1924 | else | |
1925 | table[i] = p->next_same_hash; | |
1926 | ||
1927 | p->next_same_hash = table[hash]; | |
1928 | p->prev_same_hash = 0; | |
1929 | if (table[hash]) | |
1930 | table[hash]->prev_same_hash = p; | |
1931 | table[hash] = p; | |
1932 | } | |
1933 | } | |
1934 | } | |
1935 | \f | |
7afe21cc RK |
1936 | /* Remove from the hash table any expression that is a call-clobbered |
1937 | register. Also update their TICK values. */ | |
1938 | ||
1939 | static void | |
7080f735 | 1940 | invalidate_for_call (void) |
7afe21cc | 1941 | { |
770ae6cc RK |
1942 | unsigned int regno, endregno; |
1943 | unsigned int i; | |
2197a88a | 1944 | unsigned hash; |
7afe21cc RK |
1945 | struct table_elt *p, *next; |
1946 | int in_table = 0; | |
1947 | ||
1948 | /* Go through all the hard registers. For each that is clobbered in | |
1949 | a CALL_INSN, remove the register from quantity chains and update | |
1950 | reg_tick if defined. Also see if any of these registers is currently | |
1951 | in the table. */ | |
1952 | ||
1953 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
1954 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) | |
1955 | { | |
1956 | delete_reg_equiv (regno); | |
30f72379 | 1957 | if (REG_TICK (regno) >= 0) |
46081bb3 SH |
1958 | { |
1959 | REG_TICK (regno)++; | |
1960 | SUBREG_TICKED (regno) = -1; | |
1961 | } | |
7afe21cc | 1962 | |
0e227018 | 1963 | in_table |= (TEST_HARD_REG_BIT (hard_regs_in_table, regno) != 0); |
7afe21cc RK |
1964 | } |
1965 | ||
1966 | /* In the case where we have no call-clobbered hard registers in the | |
1967 | table, we are done. Otherwise, scan the table and remove any | |
1968 | entry that overlaps a call-clobbered register. */ | |
1969 | ||
1970 | if (in_table) | |
9b1549b8 | 1971 | for (hash = 0; hash < HASH_SIZE; hash++) |
7afe21cc RK |
1972 | for (p = table[hash]; p; p = next) |
1973 | { | |
1974 | next = p->next_same_hash; | |
1975 | ||
f8cfc6aa | 1976 | if (!REG_P (p->exp) |
7afe21cc RK |
1977 | || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) |
1978 | continue; | |
1979 | ||
1980 | regno = REGNO (p->exp); | |
66fd46b6 | 1981 | endregno = regno + hard_regno_nregs[regno][GET_MODE (p->exp)]; |
7afe21cc RK |
1982 | |
1983 | for (i = regno; i < endregno; i++) | |
1984 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)) | |
1985 | { | |
1986 | remove_from_table (p, hash); | |
1987 | break; | |
1988 | } | |
1989 | } | |
1990 | } | |
1991 | \f | |
1992 | /* Given an expression X of type CONST, | |
1993 | and ELT which is its table entry (or 0 if it | |
1994 | is not in the hash table), | |
1995 | return an alternate expression for X as a register plus integer. | |
1996 | If none can be found, return 0. */ | |
1997 | ||
1998 | static rtx | |
7080f735 | 1999 | use_related_value (rtx x, struct table_elt *elt) |
7afe21cc | 2000 | { |
b3694847 SS |
2001 | struct table_elt *relt = 0; |
2002 | struct table_elt *p, *q; | |
906c4e36 | 2003 | HOST_WIDE_INT offset; |
7afe21cc RK |
2004 | |
2005 | /* First, is there anything related known? | |
2006 | If we have a table element, we can tell from that. | |
2007 | Otherwise, must look it up. */ | |
2008 | ||
2009 | if (elt != 0 && elt->related_value != 0) | |
2010 | relt = elt; | |
2011 | else if (elt == 0 && GET_CODE (x) == CONST) | |
2012 | { | |
2013 | rtx subexp = get_related_value (x); | |
2014 | if (subexp != 0) | |
2015 | relt = lookup (subexp, | |
0516f6fe | 2016 | SAFE_HASH (subexp, GET_MODE (subexp)), |
7afe21cc RK |
2017 | GET_MODE (subexp)); |
2018 | } | |
2019 | ||
2020 | if (relt == 0) | |
2021 | return 0; | |
2022 | ||
2023 | /* Search all related table entries for one that has an | |
2024 | equivalent register. */ | |
2025 | ||
2026 | p = relt; | |
2027 | while (1) | |
2028 | { | |
2029 | /* This loop is strange in that it is executed in two different cases. | |
2030 | The first is when X is already in the table. Then it is searching | |
2031 | the RELATED_VALUE list of X's class (RELT). The second case is when | |
2032 | X is not in the table. Then RELT points to a class for the related | |
2033 | value. | |
2034 | ||
2035 | Ensure that, whatever case we are in, that we ignore classes that have | |
2036 | the same value as X. */ | |
2037 | ||
2038 | if (rtx_equal_p (x, p->exp)) | |
2039 | q = 0; | |
2040 | else | |
2041 | for (q = p->first_same_value; q; q = q->next_same_value) | |
f8cfc6aa | 2042 | if (REG_P (q->exp)) |
7afe21cc RK |
2043 | break; |
2044 | ||
2045 | if (q) | |
2046 | break; | |
2047 | ||
2048 | p = p->related_value; | |
2049 | ||
2050 | /* We went all the way around, so there is nothing to be found. | |
2051 | Alternatively, perhaps RELT was in the table for some other reason | |
2052 | and it has no related values recorded. */ | |
2053 | if (p == relt || p == 0) | |
2054 | break; | |
2055 | } | |
2056 | ||
2057 | if (q == 0) | |
2058 | return 0; | |
2059 | ||
2060 | offset = (get_integer_term (x) - get_integer_term (p->exp)); | |
2061 | /* Note: OFFSET may be 0 if P->xexp and X are related by commutativity. */ | |
2062 | return plus_constant (q->exp, offset); | |
2063 | } | |
2064 | \f | |
6462bb43 AO |
2065 | /* Hash a string. Just add its bytes up. */ |
2066 | static inline unsigned | |
0516f6fe | 2067 | hash_rtx_string (const char *ps) |
6462bb43 AO |
2068 | { |
2069 | unsigned hash = 0; | |
68252e27 KH |
2070 | const unsigned char *p = (const unsigned char *) ps; |
2071 | ||
6462bb43 AO |
2072 | if (p) |
2073 | while (*p) | |
2074 | hash += *p++; | |
2075 | ||
2076 | return hash; | |
2077 | } | |
2078 | ||
7afe21cc RK |
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 | ||
0516f6fe | 2084 | Store 1 in DO_NOT_RECORD_P if any subexpression is volatile. |
7afe21cc | 2085 | |
0516f6fe SB |
2086 | If HASH_ARG_IN_MEMORY_P is not NULL, store 1 in it if X contains |
2087 | a MEM rtx which does not have the RTX_UNCHANGING_P bit set. | |
7afe21cc RK |
2088 | |
2089 | Note that cse_insn knows that the hash code of a MEM expression | |
2090 | is just (int) MEM plus the hash code of the address. */ | |
2091 | ||
0516f6fe SB |
2092 | unsigned |
2093 | hash_rtx (rtx x, enum machine_mode mode, int *do_not_record_p, | |
2094 | int *hash_arg_in_memory_p, bool have_reg_qty) | |
7afe21cc | 2095 | { |
b3694847 SS |
2096 | int i, j; |
2097 | unsigned hash = 0; | |
2098 | enum rtx_code code; | |
2099 | const char *fmt; | |
7afe21cc | 2100 | |
0516f6fe SB |
2101 | /* Used to turn recursion into iteration. We can't rely on GCC's |
2102 | tail-recursion elimination since we need to keep accumulating values | |
2103 | in HASH. */ | |
7afe21cc RK |
2104 | repeat: |
2105 | if (x == 0) | |
2106 | return hash; | |
2107 | ||
2108 | code = GET_CODE (x); | |
2109 | switch (code) | |
2110 | { | |
2111 | case REG: | |
2112 | { | |
770ae6cc | 2113 | unsigned int regno = REGNO (x); |
7afe21cc | 2114 | |
0516f6fe | 2115 | if (!reload_completed) |
7afe21cc | 2116 | { |
0516f6fe SB |
2117 | /* On some machines, we can't record any non-fixed hard register, |
2118 | because extending its life will cause reload problems. We | |
2119 | consider ap, fp, sp, gp to be fixed for this purpose. | |
2120 | ||
2121 | We also consider CCmode registers to be fixed for this purpose; | |
2122 | failure to do so leads to failure to simplify 0<100 type of | |
2123 | conditionals. | |
2124 | ||
2125 | On all machines, we can't record any global registers. | |
2126 | Nor should we record any register that is in a small | |
2127 | class, as defined by CLASS_LIKELY_SPILLED_P. */ | |
2128 | bool record; | |
2129 | ||
2130 | if (regno >= FIRST_PSEUDO_REGISTER) | |
2131 | record = true; | |
2132 | else if (x == frame_pointer_rtx | |
2133 | || x == hard_frame_pointer_rtx | |
2134 | || x == arg_pointer_rtx | |
2135 | || x == stack_pointer_rtx | |
2136 | || x == pic_offset_table_rtx) | |
2137 | record = true; | |
2138 | else if (global_regs[regno]) | |
2139 | record = false; | |
2140 | else if (fixed_regs[regno]) | |
2141 | record = true; | |
2142 | else if (GET_MODE_CLASS (GET_MODE (x)) == MODE_CC) | |
2143 | record = true; | |
2144 | else if (SMALL_REGISTER_CLASSES) | |
2145 | record = false; | |
2146 | else if (CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (regno))) | |
2147 | record = false; | |
2148 | else | |
2149 | record = true; | |
2150 | ||
2151 | if (!record) | |
2152 | { | |
2153 | *do_not_record_p = 1; | |
2154 | return 0; | |
2155 | } | |
7afe21cc | 2156 | } |
770ae6cc | 2157 | |
0516f6fe SB |
2158 | hash += ((unsigned int) REG << 7); |
2159 | hash += (have_reg_qty ? (unsigned) REG_QTY (regno) : regno); | |
2197a88a | 2160 | return hash; |
7afe21cc RK |
2161 | } |
2162 | ||
34c73909 R |
2163 | /* We handle SUBREG of a REG specially because the underlying |
2164 | reg changes its hash value with every value change; we don't | |
2165 | want to have to forget unrelated subregs when one subreg changes. */ | |
2166 | case SUBREG: | |
2167 | { | |
f8cfc6aa | 2168 | if (REG_P (SUBREG_REG (x))) |
34c73909 | 2169 | { |
0516f6fe | 2170 | hash += (((unsigned int) SUBREG << 7) |
ddef6bc7 JJ |
2171 | + REGNO (SUBREG_REG (x)) |
2172 | + (SUBREG_BYTE (x) / UNITS_PER_WORD)); | |
34c73909 R |
2173 | return hash; |
2174 | } | |
2175 | break; | |
2176 | } | |
2177 | ||
7afe21cc | 2178 | case CONST_INT: |
0516f6fe SB |
2179 | hash += (((unsigned int) CONST_INT << 7) + (unsigned int) mode |
2180 | + (unsigned int) INTVAL (x)); | |
2181 | return hash; | |
7afe21cc RK |
2182 | |
2183 | case CONST_DOUBLE: | |
2184 | /* This is like the general case, except that it only counts | |
2185 | the integers representing the constant. */ | |
0516f6fe | 2186 | hash += (unsigned int) code + (unsigned int) GET_MODE (x); |
969c8517 | 2187 | if (GET_MODE (x) != VOIDmode) |
46b33600 | 2188 | hash += real_hash (CONST_DOUBLE_REAL_VALUE (x)); |
969c8517 | 2189 | else |
0516f6fe SB |
2190 | hash += ((unsigned int) CONST_DOUBLE_LOW (x) |
2191 | + (unsigned int) CONST_DOUBLE_HIGH (x)); | |
7afe21cc RK |
2192 | return hash; |
2193 | ||
69ef87e2 AH |
2194 | case CONST_VECTOR: |
2195 | { | |
2196 | int units; | |
2197 | rtx elt; | |
2198 | ||
2199 | units = CONST_VECTOR_NUNITS (x); | |
2200 | ||
2201 | for (i = 0; i < units; ++i) | |
2202 | { | |
2203 | elt = CONST_VECTOR_ELT (x, i); | |
0516f6fe SB |
2204 | hash += hash_rtx (elt, GET_MODE (elt), do_not_record_p, |
2205 | hash_arg_in_memory_p, have_reg_qty); | |
69ef87e2 AH |
2206 | } |
2207 | ||
2208 | return hash; | |
2209 | } | |
2210 | ||
7afe21cc RK |
2211 | /* Assume there is only one rtx object for any given label. */ |
2212 | case LABEL_REF: | |
0516f6fe SB |
2213 | /* We don't hash on the address of the CODE_LABEL to avoid bootstrap |
2214 | differences and differences between each stage's debugging dumps. */ | |
2215 | hash += (((unsigned int) LABEL_REF << 7) | |
2216 | + CODE_LABEL_NUMBER (XEXP (x, 0))); | |
2197a88a | 2217 | return hash; |
7afe21cc RK |
2218 | |
2219 | case SYMBOL_REF: | |
0516f6fe SB |
2220 | { |
2221 | /* Don't hash on the symbol's address to avoid bootstrap differences. | |
2222 | Different hash values may cause expressions to be recorded in | |
2223 | different orders and thus different registers to be used in the | |
2224 | final assembler. This also avoids differences in the dump files | |
2225 | between various stages. */ | |
2226 | unsigned int h = 0; | |
2227 | const unsigned char *p = (const unsigned char *) XSTR (x, 0); | |
2228 | ||
2229 | while (*p) | |
2230 | h += (h << 7) + *p++; /* ??? revisit */ | |
2231 | ||
2232 | hash += ((unsigned int) SYMBOL_REF << 7) + h; | |
2233 | return hash; | |
2234 | } | |
7afe21cc RK |
2235 | |
2236 | case MEM: | |
14a774a9 RK |
2237 | /* We don't record if marked volatile or if BLKmode since we don't |
2238 | know the size of the move. */ | |
2239 | if (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode) | |
7afe21cc | 2240 | { |
0516f6fe | 2241 | *do_not_record_p = 1; |
7afe21cc RK |
2242 | return 0; |
2243 | } | |
0516f6fe SB |
2244 | if (hash_arg_in_memory_p && !MEM_READONLY_P (x)) |
2245 | *hash_arg_in_memory_p = 1; | |
4977bab6 | 2246 | |
7afe21cc RK |
2247 | /* Now that we have already found this special case, |
2248 | might as well speed it up as much as possible. */ | |
2197a88a | 2249 | hash += (unsigned) MEM; |
7afe21cc RK |
2250 | x = XEXP (x, 0); |
2251 | goto repeat; | |
2252 | ||
bb07060a JW |
2253 | case USE: |
2254 | /* A USE that mentions non-volatile memory needs special | |
2255 | handling since the MEM may be BLKmode which normally | |
2256 | prevents an entry from being made. Pure calls are | |
0516f6fe SB |
2257 | marked by a USE which mentions BLKmode memory. |
2258 | See calls.c:emit_call_1. */ | |
3c0cb5de | 2259 | if (MEM_P (XEXP (x, 0)) |
bb07060a JW |
2260 | && ! MEM_VOLATILE_P (XEXP (x, 0))) |
2261 | { | |
68252e27 | 2262 | hash += (unsigned) USE; |
bb07060a JW |
2263 | x = XEXP (x, 0); |
2264 | ||
0516f6fe SB |
2265 | if (hash_arg_in_memory_p && !MEM_READONLY_P (x)) |
2266 | *hash_arg_in_memory_p = 1; | |
bb07060a JW |
2267 | |
2268 | /* Now that we have already found this special case, | |
2269 | might as well speed it up as much as possible. */ | |
2270 | hash += (unsigned) MEM; | |
2271 | x = XEXP (x, 0); | |
2272 | goto repeat; | |
2273 | } | |
2274 | break; | |
2275 | ||
7afe21cc RK |
2276 | case PRE_DEC: |
2277 | case PRE_INC: | |
2278 | case POST_DEC: | |
2279 | case POST_INC: | |
4b983fdc RH |
2280 | case PRE_MODIFY: |
2281 | case POST_MODIFY: | |
7afe21cc RK |
2282 | case PC: |
2283 | case CC0: | |
2284 | case CALL: | |
2285 | case UNSPEC_VOLATILE: | |
0516f6fe | 2286 | *do_not_record_p = 1; |
7afe21cc RK |
2287 | return 0; |
2288 | ||
2289 | case ASM_OPERANDS: | |
2290 | if (MEM_VOLATILE_P (x)) | |
2291 | { | |
0516f6fe | 2292 | *do_not_record_p = 1; |
7afe21cc RK |
2293 | return 0; |
2294 | } | |
6462bb43 AO |
2295 | else |
2296 | { | |
2297 | /* We don't want to take the filename and line into account. */ | |
2298 | hash += (unsigned) code + (unsigned) GET_MODE (x) | |
0516f6fe SB |
2299 | + hash_rtx_string (ASM_OPERANDS_TEMPLATE (x)) |
2300 | + hash_rtx_string (ASM_OPERANDS_OUTPUT_CONSTRAINT (x)) | |
6462bb43 AO |
2301 | + (unsigned) ASM_OPERANDS_OUTPUT_IDX (x); |
2302 | ||
2303 | if (ASM_OPERANDS_INPUT_LENGTH (x)) | |
2304 | { | |
2305 | for (i = 1; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) | |
2306 | { | |
0516f6fe SB |
2307 | hash += (hash_rtx (ASM_OPERANDS_INPUT (x, i), |
2308 | GET_MODE (ASM_OPERANDS_INPUT (x, i)), | |
2309 | do_not_record_p, hash_arg_in_memory_p, | |
2310 | have_reg_qty) | |
2311 | + hash_rtx_string | |
2312 | (ASM_OPERANDS_INPUT_CONSTRAINT (x, i))); | |
6462bb43 AO |
2313 | } |
2314 | ||
0516f6fe | 2315 | hash += hash_rtx_string (ASM_OPERANDS_INPUT_CONSTRAINT (x, 0)); |
6462bb43 AO |
2316 | x = ASM_OPERANDS_INPUT (x, 0); |
2317 | mode = GET_MODE (x); | |
2318 | goto repeat; | |
2319 | } | |
2320 | ||
2321 | return hash; | |
2322 | } | |
e9a25f70 | 2323 | break; |
278a83b2 | 2324 | |
e9a25f70 JL |
2325 | default: |
2326 | break; | |
7afe21cc RK |
2327 | } |
2328 | ||
2329 | i = GET_RTX_LENGTH (code) - 1; | |
2197a88a | 2330 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
7afe21cc RK |
2331 | fmt = GET_RTX_FORMAT (code); |
2332 | for (; i >= 0; i--) | |
2333 | { | |
341c100f | 2334 | switch (fmt[i]) |
7afe21cc | 2335 | { |
341c100f | 2336 | case 'e': |
7afe21cc RK |
2337 | /* If we are about to do the last recursive call |
2338 | needed at this level, change it into iteration. | |
2339 | This function is called enough to be worth it. */ | |
2340 | if (i == 0) | |
2341 | { | |
0516f6fe | 2342 | x = XEXP (x, i); |
7afe21cc RK |
2343 | goto repeat; |
2344 | } | |
0516f6fe SB |
2345 | |
2346 | hash += hash_rtx (XEXP (x, i), 0, do_not_record_p, | |
2347 | hash_arg_in_memory_p, have_reg_qty); | |
341c100f | 2348 | break; |
0516f6fe | 2349 | |
341c100f NS |
2350 | case 'E': |
2351 | for (j = 0; j < XVECLEN (x, i); j++) | |
0516f6fe SB |
2352 | hash += hash_rtx (XVECEXP (x, i, j), 0, do_not_record_p, |
2353 | hash_arg_in_memory_p, have_reg_qty); | |
341c100f | 2354 | break; |
0516f6fe | 2355 | |
341c100f NS |
2356 | case 's': |
2357 | hash += hash_rtx_string (XSTR (x, i)); | |
2358 | break; | |
2359 | ||
2360 | case 'i': | |
2361 | hash += (unsigned int) XINT (x, i); | |
2362 | break; | |
2363 | ||
2364 | case '0': case 't': | |
2365 | /* Unused. */ | |
2366 | break; | |
2367 | ||
2368 | default: | |
2369 | gcc_unreachable (); | |
2370 | } | |
7afe21cc | 2371 | } |
0516f6fe | 2372 | |
7afe21cc RK |
2373 | return hash; |
2374 | } | |
2375 | ||
0516f6fe SB |
2376 | /* Hash an rtx X for cse via hash_rtx. |
2377 | Stores 1 in do_not_record if any subexpression is volatile. | |
2378 | Stores 1 in hash_arg_in_memory if X contains a mem rtx which | |
2379 | does not have the RTX_UNCHANGING_P bit set. */ | |
2380 | ||
2381 | static inline unsigned | |
2382 | canon_hash (rtx x, enum machine_mode mode) | |
2383 | { | |
2384 | return hash_rtx (x, mode, &do_not_record, &hash_arg_in_memory, true); | |
2385 | } | |
2386 | ||
2387 | /* Like canon_hash but with no side effects, i.e. do_not_record | |
2388 | and hash_arg_in_memory are not changed. */ | |
7afe21cc | 2389 | |
0516f6fe | 2390 | static inline unsigned |
7080f735 | 2391 | safe_hash (rtx x, enum machine_mode mode) |
7afe21cc | 2392 | { |
0516f6fe SB |
2393 | int dummy_do_not_record; |
2394 | return hash_rtx (x, mode, &dummy_do_not_record, NULL, true); | |
7afe21cc RK |
2395 | } |
2396 | \f | |
2397 | /* Return 1 iff X and Y would canonicalize into the same thing, | |
2398 | without actually constructing the canonicalization of either one. | |
2399 | If VALIDATE is nonzero, | |
2400 | we assume X is an expression being processed from the rtl | |
2401 | and Y was found in the hash table. We check register refs | |
2402 | in Y for being marked as valid. | |
2403 | ||
0516f6fe | 2404 | If FOR_GCSE is true, we compare X and Y for equivalence for GCSE. */ |
7afe21cc | 2405 | |
0516f6fe SB |
2406 | int |
2407 | exp_equiv_p (rtx x, rtx y, int validate, bool for_gcse) | |
7afe21cc | 2408 | { |
b3694847 SS |
2409 | int i, j; |
2410 | enum rtx_code code; | |
2411 | const char *fmt; | |
7afe21cc RK |
2412 | |
2413 | /* Note: it is incorrect to assume an expression is equivalent to itself | |
2414 | if VALIDATE is nonzero. */ | |
2415 | if (x == y && !validate) | |
2416 | return 1; | |
0516f6fe | 2417 | |
7afe21cc RK |
2418 | if (x == 0 || y == 0) |
2419 | return x == y; | |
2420 | ||
2421 | code = GET_CODE (x); | |
2422 | if (code != GET_CODE (y)) | |
0516f6fe | 2423 | return 0; |
7afe21cc RK |
2424 | |
2425 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
2426 | if (GET_MODE (x) != GET_MODE (y)) | |
2427 | return 0; | |
2428 | ||
2429 | switch (code) | |
2430 | { | |
2431 | case PC: | |
2432 | case CC0: | |
7afe21cc | 2433 | case CONST_INT: |
37cf6116 | 2434 | case CONST_DOUBLE: |
c13e8210 | 2435 | return x == y; |
7afe21cc RK |
2436 | |
2437 | case LABEL_REF: | |
7afe21cc RK |
2438 | return XEXP (x, 0) == XEXP (y, 0); |
2439 | ||
f54d4924 RK |
2440 | case SYMBOL_REF: |
2441 | return XSTR (x, 0) == XSTR (y, 0); | |
2442 | ||
7afe21cc | 2443 | case REG: |
0516f6fe SB |
2444 | if (for_gcse) |
2445 | return REGNO (x) == REGNO (y); | |
2446 | else | |
2447 | { | |
2448 | unsigned int regno = REGNO (y); | |
2449 | unsigned int i; | |
2450 | unsigned int endregno | |
2451 | = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1 | |
2452 | : hard_regno_nregs[regno][GET_MODE (y)]); | |
7afe21cc | 2453 | |
0516f6fe SB |
2454 | /* If the quantities are not the same, the expressions are not |
2455 | equivalent. If there are and we are not to validate, they | |
2456 | are equivalent. Otherwise, ensure all regs are up-to-date. */ | |
7afe21cc | 2457 | |
0516f6fe SB |
2458 | if (REG_QTY (REGNO (x)) != REG_QTY (regno)) |
2459 | return 0; | |
2460 | ||
2461 | if (! validate) | |
2462 | return 1; | |
2463 | ||
2464 | for (i = regno; i < endregno; i++) | |
2465 | if (REG_IN_TABLE (i) != REG_TICK (i)) | |
2466 | return 0; | |
7afe21cc | 2467 | |
7afe21cc | 2468 | return 1; |
0516f6fe | 2469 | } |
7afe21cc | 2470 | |
0516f6fe SB |
2471 | case MEM: |
2472 | if (for_gcse) | |
2473 | { | |
0516f6fe SB |
2474 | /* A volatile mem should not be considered equivalent to any |
2475 | other. */ | |
2476 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
2477 | return 0; | |
78b76d08 SB |
2478 | |
2479 | /* Can't merge two expressions in different alias sets, since we | |
2480 | can decide that the expression is transparent in a block when | |
2481 | it isn't, due to it being set with the different alias set. | |
2482 | ||
2483 | Also, can't merge two expressions with different MEM_ATTRS. | |
2484 | They could e.g. be two different entities allocated into the | |
2485 | same space on the stack (see e.g. PR25130). In that case, the | |
2486 | MEM addresses can be the same, even though the two MEMs are | |
2487 | absolutely not equivalent. | |
2488 | ||
2489 | But because really all MEM attributes should be the same for | |
2490 | equivalent MEMs, we just use the invariant that MEMs that have | |
2491 | the same attributes share the same mem_attrs data structure. */ | |
2492 | if (MEM_ATTRS (x) != MEM_ATTRS (y)) | |
2493 | return 0; | |
0516f6fe SB |
2494 | } |
2495 | break; | |
7afe21cc RK |
2496 | |
2497 | /* For commutative operations, check both orders. */ | |
2498 | case PLUS: | |
2499 | case MULT: | |
2500 | case AND: | |
2501 | case IOR: | |
2502 | case XOR: | |
2503 | case NE: | |
2504 | case EQ: | |
0516f6fe SB |
2505 | return ((exp_equiv_p (XEXP (x, 0), XEXP (y, 0), |
2506 | validate, for_gcse) | |
7afe21cc | 2507 | && exp_equiv_p (XEXP (x, 1), XEXP (y, 1), |
0516f6fe | 2508 | validate, for_gcse)) |
7afe21cc | 2509 | || (exp_equiv_p (XEXP (x, 0), XEXP (y, 1), |
0516f6fe | 2510 | validate, for_gcse) |
7afe21cc | 2511 | && exp_equiv_p (XEXP (x, 1), XEXP (y, 0), |
0516f6fe | 2512 | validate, for_gcse))); |
278a83b2 | 2513 | |
6462bb43 AO |
2514 | case ASM_OPERANDS: |
2515 | /* We don't use the generic code below because we want to | |
2516 | disregard filename and line numbers. */ | |
2517 | ||
2518 | /* A volatile asm isn't equivalent to any other. */ | |
2519 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
2520 | return 0; | |
2521 | ||
2522 | if (GET_MODE (x) != GET_MODE (y) | |
2523 | || strcmp (ASM_OPERANDS_TEMPLATE (x), ASM_OPERANDS_TEMPLATE (y)) | |
2524 | || strcmp (ASM_OPERANDS_OUTPUT_CONSTRAINT (x), | |
2525 | ASM_OPERANDS_OUTPUT_CONSTRAINT (y)) | |
2526 | || ASM_OPERANDS_OUTPUT_IDX (x) != ASM_OPERANDS_OUTPUT_IDX (y) | |
2527 | || ASM_OPERANDS_INPUT_LENGTH (x) != ASM_OPERANDS_INPUT_LENGTH (y)) | |
2528 | return 0; | |
2529 | ||
2530 | if (ASM_OPERANDS_INPUT_LENGTH (x)) | |
2531 | { | |
2532 | for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
2533 | if (! exp_equiv_p (ASM_OPERANDS_INPUT (x, i), | |
2534 | ASM_OPERANDS_INPUT (y, i), | |
0516f6fe | 2535 | validate, for_gcse) |
6462bb43 AO |
2536 | || strcmp (ASM_OPERANDS_INPUT_CONSTRAINT (x, i), |
2537 | ASM_OPERANDS_INPUT_CONSTRAINT (y, i))) | |
2538 | return 0; | |
2539 | } | |
2540 | ||
2541 | return 1; | |
2542 | ||
e9a25f70 JL |
2543 | default: |
2544 | break; | |
7afe21cc RK |
2545 | } |
2546 | ||
2547 | /* Compare the elements. If any pair of corresponding elements | |
0516f6fe | 2548 | fail to match, return 0 for the whole thing. */ |
7afe21cc RK |
2549 | |
2550 | fmt = GET_RTX_FORMAT (code); | |
2551 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2552 | { | |
906c4e36 | 2553 | switch (fmt[i]) |
7afe21cc | 2554 | { |
906c4e36 | 2555 | case 'e': |
0516f6fe SB |
2556 | if (! exp_equiv_p (XEXP (x, i), XEXP (y, i), |
2557 | validate, for_gcse)) | |
7afe21cc | 2558 | return 0; |
906c4e36 RK |
2559 | break; |
2560 | ||
2561 | case 'E': | |
7afe21cc RK |
2562 | if (XVECLEN (x, i) != XVECLEN (y, i)) |
2563 | return 0; | |
2564 | for (j = 0; j < XVECLEN (x, i); j++) | |
2565 | if (! exp_equiv_p (XVECEXP (x, i, j), XVECEXP (y, i, j), | |
0516f6fe | 2566 | validate, for_gcse)) |
7afe21cc | 2567 | return 0; |
906c4e36 RK |
2568 | break; |
2569 | ||
2570 | case 's': | |
7afe21cc RK |
2571 | if (strcmp (XSTR (x, i), XSTR (y, i))) |
2572 | return 0; | |
906c4e36 RK |
2573 | break; |
2574 | ||
2575 | case 'i': | |
7afe21cc RK |
2576 | if (XINT (x, i) != XINT (y, i)) |
2577 | return 0; | |
906c4e36 RK |
2578 | break; |
2579 | ||
2580 | case 'w': | |
2581 | if (XWINT (x, i) != XWINT (y, i)) | |
2582 | return 0; | |
278a83b2 | 2583 | break; |
906c4e36 RK |
2584 | |
2585 | case '0': | |
8f985ec4 | 2586 | case 't': |
906c4e36 RK |
2587 | break; |
2588 | ||
2589 | default: | |
341c100f | 2590 | gcc_unreachable (); |
7afe21cc | 2591 | } |
278a83b2 | 2592 | } |
906c4e36 | 2593 | |
7afe21cc RK |
2594 | return 1; |
2595 | } | |
2596 | \f | |
9ae8ffe7 JL |
2597 | /* Return 1 if X has a value that can vary even between two |
2598 | executions of the program. 0 means X can be compared reliably | |
2599 | against certain constants or near-constants. */ | |
7afe21cc RK |
2600 | |
2601 | static int | |
7080f735 | 2602 | cse_rtx_varies_p (rtx x, int from_alias) |
7afe21cc RK |
2603 | { |
2604 | /* We need not check for X and the equivalence class being of the same | |
2605 | mode because if X is equivalent to a constant in some mode, it | |
2606 | doesn't vary in any mode. */ | |
2607 | ||
f8cfc6aa | 2608 | if (REG_P (x) |
1bb98cec DM |
2609 | && REGNO_QTY_VALID_P (REGNO (x))) |
2610 | { | |
2611 | int x_q = REG_QTY (REGNO (x)); | |
2612 | struct qty_table_elem *x_ent = &qty_table[x_q]; | |
2613 | ||
2614 | if (GET_MODE (x) == x_ent->mode | |
2615 | && x_ent->const_rtx != NULL_RTX) | |
2616 | return 0; | |
2617 | } | |
7afe21cc | 2618 | |
9ae8ffe7 JL |
2619 | if (GET_CODE (x) == PLUS |
2620 | && GET_CODE (XEXP (x, 1)) == CONST_INT | |
f8cfc6aa | 2621 | && REG_P (XEXP (x, 0)) |
1bb98cec DM |
2622 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0)))) |
2623 | { | |
2624 | int x0_q = REG_QTY (REGNO (XEXP (x, 0))); | |
2625 | struct qty_table_elem *x0_ent = &qty_table[x0_q]; | |
2626 | ||
2627 | if ((GET_MODE (XEXP (x, 0)) == x0_ent->mode) | |
2628 | && x0_ent->const_rtx != NULL_RTX) | |
2629 | return 0; | |
2630 | } | |
7afe21cc | 2631 | |
9c6b0bae RK |
2632 | /* This can happen as the result of virtual register instantiation, if |
2633 | the initial constant is too large to be a valid address. This gives | |
2634 | us a three instruction sequence, load large offset into a register, | |
2635 | load fp minus a constant into a register, then a MEM which is the | |
2636 | sum of the two `constant' registers. */ | |
9ae8ffe7 | 2637 | if (GET_CODE (x) == PLUS |
f8cfc6aa JQ |
2638 | && REG_P (XEXP (x, 0)) |
2639 | && REG_P (XEXP (x, 1)) | |
9ae8ffe7 | 2640 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))) |
1bb98cec DM |
2641 | && REGNO_QTY_VALID_P (REGNO (XEXP (x, 1)))) |
2642 | { | |
2643 | int x0_q = REG_QTY (REGNO (XEXP (x, 0))); | |
2644 | int x1_q = REG_QTY (REGNO (XEXP (x, 1))); | |
2645 | struct qty_table_elem *x0_ent = &qty_table[x0_q]; | |
2646 | struct qty_table_elem *x1_ent = &qty_table[x1_q]; | |
2647 | ||
2648 | if ((GET_MODE (XEXP (x, 0)) == x0_ent->mode) | |
2649 | && x0_ent->const_rtx != NULL_RTX | |
2650 | && (GET_MODE (XEXP (x, 1)) == x1_ent->mode) | |
2651 | && x1_ent->const_rtx != NULL_RTX) | |
2652 | return 0; | |
2653 | } | |
9c6b0bae | 2654 | |
2be28ee2 | 2655 | return rtx_varies_p (x, from_alias); |
7afe21cc RK |
2656 | } |
2657 | \f | |
eef3c949 RS |
2658 | /* Subroutine of canon_reg. Pass *XLOC through canon_reg, and validate |
2659 | the result if necessary. INSN is as for canon_reg. */ | |
2660 | ||
2661 | static void | |
2662 | validate_canon_reg (rtx *xloc, rtx insn) | |
2663 | { | |
2664 | rtx new = canon_reg (*xloc, insn); | |
eef3c949 RS |
2665 | |
2666 | /* If replacing pseudo with hard reg or vice versa, ensure the | |
2667 | insn remains valid. Likewise if the insn has MATCH_DUPs. */ | |
67e0a632 | 2668 | if (insn != 0 && new != 0) |
eef3c949 RS |
2669 | validate_change (insn, xloc, new, 1); |
2670 | else | |
2671 | *xloc = new; | |
2672 | } | |
2673 | ||
7afe21cc RK |
2674 | /* Canonicalize an expression: |
2675 | replace each register reference inside it | |
2676 | with the "oldest" equivalent register. | |
2677 | ||
67e0a632 | 2678 | If INSN is nonzero validate_change is used to ensure that INSN remains valid |
da7d8304 | 2679 | after we make our substitution. The calls are made with IN_GROUP nonzero |
7722328e RK |
2680 | so apply_change_group must be called upon the outermost return from this |
2681 | function (unless INSN is zero). The result of apply_change_group can | |
2682 | generally be discarded since the changes we are making are optional. */ | |
7afe21cc RK |
2683 | |
2684 | static rtx | |
7080f735 | 2685 | canon_reg (rtx x, rtx insn) |
7afe21cc | 2686 | { |
b3694847 SS |
2687 | int i; |
2688 | enum rtx_code code; | |
2689 | const char *fmt; | |
7afe21cc RK |
2690 | |
2691 | if (x == 0) | |
2692 | return x; | |
2693 | ||
2694 | code = GET_CODE (x); | |
2695 | switch (code) | |
2696 | { | |
2697 | case PC: | |
2698 | case CC0: | |
2699 | case CONST: | |
2700 | case CONST_INT: | |
2701 | case CONST_DOUBLE: | |
69ef87e2 | 2702 | case CONST_VECTOR: |
7afe21cc RK |
2703 | case SYMBOL_REF: |
2704 | case LABEL_REF: | |
2705 | case ADDR_VEC: | |
2706 | case ADDR_DIFF_VEC: | |
2707 | return x; | |
2708 | ||
2709 | case REG: | |
2710 | { | |
b3694847 SS |
2711 | int first; |
2712 | int q; | |
2713 | struct qty_table_elem *ent; | |
7afe21cc RK |
2714 | |
2715 | /* Never replace a hard reg, because hard regs can appear | |
2716 | in more than one machine mode, and we must preserve the mode | |
2717 | of each occurrence. Also, some hard regs appear in | |
2718 | MEMs that are shared and mustn't be altered. Don't try to | |
2719 | replace any reg that maps to a reg of class NO_REGS. */ | |
2720 | if (REGNO (x) < FIRST_PSEUDO_REGISTER | |
2721 | || ! REGNO_QTY_VALID_P (REGNO (x))) | |
2722 | return x; | |
2723 | ||
278a83b2 | 2724 | q = REG_QTY (REGNO (x)); |
1bb98cec DM |
2725 | ent = &qty_table[q]; |
2726 | first = ent->first_reg; | |
7afe21cc RK |
2727 | return (first >= FIRST_PSEUDO_REGISTER ? regno_reg_rtx[first] |
2728 | : REGNO_REG_CLASS (first) == NO_REGS ? x | |
1bb98cec | 2729 | : gen_rtx_REG (ent->mode, first)); |
7afe21cc | 2730 | } |
278a83b2 | 2731 | |
e9a25f70 JL |
2732 | default: |
2733 | break; | |
7afe21cc RK |
2734 | } |
2735 | ||
2736 | fmt = GET_RTX_FORMAT (code); | |
2737 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2738 | { | |
b3694847 | 2739 | int j; |
7afe21cc RK |
2740 | |
2741 | if (fmt[i] == 'e') | |
eef3c949 | 2742 | validate_canon_reg (&XEXP (x, i), insn); |
7afe21cc RK |
2743 | else if (fmt[i] == 'E') |
2744 | for (j = 0; j < XVECLEN (x, i); j++) | |
eef3c949 | 2745 | validate_canon_reg (&XVECEXP (x, i, j), insn); |
7afe21cc RK |
2746 | } |
2747 | ||
2748 | return x; | |
2749 | } | |
2750 | \f | |
bca05d20 RK |
2751 | /* Given an operation (CODE, *PARG1, *PARG2), where code is a comparison |
2752 | operation (EQ, NE, GT, etc.), follow it back through the hash table and | |
2753 | what values are being compared. | |
1a87eea2 | 2754 | |
bca05d20 RK |
2755 | *PARG1 and *PARG2 are updated to contain the rtx representing the values |
2756 | actually being compared. For example, if *PARG1 was (cc0) and *PARG2 | |
2757 | was (const_int 0), *PARG1 and *PARG2 will be set to the objects that were | |
2758 | compared to produce cc0. | |
a432f20d | 2759 | |
bca05d20 RK |
2760 | The return value is the comparison operator and is either the code of |
2761 | A or the code corresponding to the inverse of the comparison. */ | |
7afe21cc | 2762 | |
0cedb36c | 2763 | static enum rtx_code |
7080f735 AJ |
2764 | find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2, |
2765 | enum machine_mode *pmode1, enum machine_mode *pmode2) | |
7afe21cc | 2766 | { |
0cedb36c | 2767 | rtx arg1, arg2; |
1a87eea2 | 2768 | |
0cedb36c | 2769 | arg1 = *parg1, arg2 = *parg2; |
7afe21cc | 2770 | |
0cedb36c | 2771 | /* If ARG2 is const0_rtx, see what ARG1 is equivalent to. */ |
7afe21cc | 2772 | |
0cedb36c | 2773 | while (arg2 == CONST0_RTX (GET_MODE (arg1))) |
a432f20d | 2774 | { |
da7d8304 | 2775 | /* Set nonzero when we find something of interest. */ |
0cedb36c JL |
2776 | rtx x = 0; |
2777 | int reverse_code = 0; | |
2778 | struct table_elt *p = 0; | |
6076248a | 2779 | |
0cedb36c JL |
2780 | /* If arg1 is a COMPARE, extract the comparison arguments from it. |
2781 | On machines with CC0, this is the only case that can occur, since | |
2782 | fold_rtx will return the COMPARE or item being compared with zero | |
2783 | when given CC0. */ | |
6076248a | 2784 | |
0cedb36c JL |
2785 | if (GET_CODE (arg1) == COMPARE && arg2 == const0_rtx) |
2786 | x = arg1; | |
6076248a | 2787 | |
0cedb36c JL |
2788 | /* If ARG1 is a comparison operator and CODE is testing for |
2789 | STORE_FLAG_VALUE, get the inner arguments. */ | |
a432f20d | 2790 | |
ec8e098d | 2791 | else if (COMPARISON_P (arg1)) |
7afe21cc | 2792 | { |
efdc7e19 RH |
2793 | #ifdef FLOAT_STORE_FLAG_VALUE |
2794 | REAL_VALUE_TYPE fsfv; | |
2795 | #endif | |
2796 | ||
0cedb36c JL |
2797 | if (code == NE |
2798 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT | |
2799 | && code == LT && STORE_FLAG_VALUE == -1) | |
2800 | #ifdef FLOAT_STORE_FLAG_VALUE | |
9b92bf04 | 2801 | || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1)) |
efdc7e19 RH |
2802 | && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)), |
2803 | REAL_VALUE_NEGATIVE (fsfv))) | |
7afe21cc | 2804 | #endif |
a432f20d | 2805 | ) |
0cedb36c JL |
2806 | x = arg1; |
2807 | else if (code == EQ | |
2808 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT | |
2809 | && code == GE && STORE_FLAG_VALUE == -1) | |
2810 | #ifdef FLOAT_STORE_FLAG_VALUE | |
9b92bf04 | 2811 | || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1)) |
efdc7e19 RH |
2812 | && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)), |
2813 | REAL_VALUE_NEGATIVE (fsfv))) | |
0cedb36c JL |
2814 | #endif |
2815 | ) | |
2816 | x = arg1, reverse_code = 1; | |
7afe21cc RK |
2817 | } |
2818 | ||
0cedb36c | 2819 | /* ??? We could also check for |
7afe21cc | 2820 | |
0cedb36c | 2821 | (ne (and (eq (...) (const_int 1))) (const_int 0)) |
7afe21cc | 2822 | |
0cedb36c | 2823 | and related forms, but let's wait until we see them occurring. */ |
7afe21cc | 2824 | |
0cedb36c JL |
2825 | if (x == 0) |
2826 | /* Look up ARG1 in the hash table and see if it has an equivalence | |
2827 | that lets us see what is being compared. */ | |
0516f6fe | 2828 | p = lookup (arg1, SAFE_HASH (arg1, GET_MODE (arg1)), GET_MODE (arg1)); |
278a83b2 | 2829 | if (p) |
8b03b984 R |
2830 | { |
2831 | p = p->first_same_value; | |
2832 | ||
2833 | /* If what we compare is already known to be constant, that is as | |
2834 | good as it gets. | |
2835 | We need to break the loop in this case, because otherwise we | |
2836 | can have an infinite loop when looking at a reg that is known | |
2837 | to be a constant which is the same as a comparison of a reg | |
2838 | against zero which appears later in the insn stream, which in | |
2839 | turn is constant and the same as the comparison of the first reg | |
2840 | against zero... */ | |
2841 | if (p->is_const) | |
2842 | break; | |
2843 | } | |
7afe21cc | 2844 | |
0cedb36c | 2845 | for (; p; p = p->next_same_value) |
7afe21cc | 2846 | { |
0cedb36c | 2847 | enum machine_mode inner_mode = GET_MODE (p->exp); |
efdc7e19 RH |
2848 | #ifdef FLOAT_STORE_FLAG_VALUE |
2849 | REAL_VALUE_TYPE fsfv; | |
2850 | #endif | |
7afe21cc | 2851 | |
0cedb36c | 2852 | /* If the entry isn't valid, skip it. */ |
0516f6fe | 2853 | if (! exp_equiv_p (p->exp, p->exp, 1, false)) |
0cedb36c | 2854 | continue; |
f76b9db2 | 2855 | |
bca05d20 RK |
2856 | if (GET_CODE (p->exp) == COMPARE |
2857 | /* Another possibility is that this machine has a compare insn | |
2858 | that includes the comparison code. In that case, ARG1 would | |
2859 | be equivalent to a comparison operation that would set ARG1 to | |
2860 | either STORE_FLAG_VALUE or zero. If this is an NE operation, | |
2861 | ORIG_CODE is the actual comparison being done; if it is an EQ, | |
2862 | we must reverse ORIG_CODE. On machine with a negative value | |
2863 | for STORE_FLAG_VALUE, also look at LT and GE operations. */ | |
2864 | || ((code == NE | |
2865 | || (code == LT | |
2866 | && GET_MODE_CLASS (inner_mode) == MODE_INT | |
2867 | && (GET_MODE_BITSIZE (inner_mode) | |
2868 | <= HOST_BITS_PER_WIDE_INT) | |
2869 | && (STORE_FLAG_VALUE | |
2870 | & ((HOST_WIDE_INT) 1 | |
2871 | << (GET_MODE_BITSIZE (inner_mode) - 1)))) | |
0cedb36c | 2872 | #ifdef FLOAT_STORE_FLAG_VALUE |
bca05d20 | 2873 | || (code == LT |
3d8bf70f | 2874 | && SCALAR_FLOAT_MODE_P (inner_mode) |
efdc7e19 RH |
2875 | && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)), |
2876 | REAL_VALUE_NEGATIVE (fsfv))) | |
0cedb36c | 2877 | #endif |
bca05d20 | 2878 | ) |
ec8e098d | 2879 | && COMPARISON_P (p->exp))) |
7afe21cc | 2880 | { |
0cedb36c JL |
2881 | x = p->exp; |
2882 | break; | |
2883 | } | |
2884 | else if ((code == EQ | |
2885 | || (code == GE | |
2886 | && GET_MODE_CLASS (inner_mode) == MODE_INT | |
2887 | && (GET_MODE_BITSIZE (inner_mode) | |
2888 | <= HOST_BITS_PER_WIDE_INT) | |
2889 | && (STORE_FLAG_VALUE | |
2890 | & ((HOST_WIDE_INT) 1 | |
2891 | << (GET_MODE_BITSIZE (inner_mode) - 1)))) | |
2892 | #ifdef FLOAT_STORE_FLAG_VALUE | |
2893 | || (code == GE | |
3d8bf70f | 2894 | && SCALAR_FLOAT_MODE_P (inner_mode) |
efdc7e19 RH |
2895 | && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)), |
2896 | REAL_VALUE_NEGATIVE (fsfv))) | |
0cedb36c JL |
2897 | #endif |
2898 | ) | |
ec8e098d | 2899 | && COMPARISON_P (p->exp)) |
0cedb36c JL |
2900 | { |
2901 | reverse_code = 1; | |
2902 | x = p->exp; | |
2903 | break; | |
7afe21cc RK |
2904 | } |
2905 | ||
4977bab6 ZW |
2906 | /* If this non-trapping address, e.g. fp + constant, the |
2907 | equivalent is a better operand since it may let us predict | |
2908 | the value of the comparison. */ | |
2909 | else if (!rtx_addr_can_trap_p (p->exp)) | |
0cedb36c JL |
2910 | { |
2911 | arg1 = p->exp; | |
2912 | continue; | |
2913 | } | |
7afe21cc | 2914 | } |
7afe21cc | 2915 | |
0cedb36c JL |
2916 | /* If we didn't find a useful equivalence for ARG1, we are done. |
2917 | Otherwise, set up for the next iteration. */ | |
2918 | if (x == 0) | |
2919 | break; | |
7afe21cc | 2920 | |
78192b09 RH |
2921 | /* If we need to reverse the comparison, make sure that that is |
2922 | possible -- we can't necessarily infer the value of GE from LT | |
2923 | with floating-point operands. */ | |
0cedb36c | 2924 | if (reverse_code) |
261efdef JH |
2925 | { |
2926 | enum rtx_code reversed = reversed_comparison_code (x, NULL_RTX); | |
2927 | if (reversed == UNKNOWN) | |
2928 | break; | |
68252e27 KH |
2929 | else |
2930 | code = reversed; | |
261efdef | 2931 | } |
ec8e098d | 2932 | else if (COMPARISON_P (x)) |
261efdef JH |
2933 | code = GET_CODE (x); |
2934 | arg1 = XEXP (x, 0), arg2 = XEXP (x, 1); | |
7afe21cc RK |
2935 | } |
2936 | ||
0cedb36c JL |
2937 | /* Return our results. Return the modes from before fold_rtx |
2938 | because fold_rtx might produce const_int, and then it's too late. */ | |
2939 | *pmode1 = GET_MODE (arg1), *pmode2 = GET_MODE (arg2); | |
2940 | *parg1 = fold_rtx (arg1, 0), *parg2 = fold_rtx (arg2, 0); | |
2941 | ||
2942 | return code; | |
7afe21cc RK |
2943 | } |
2944 | \f | |
a52b023a PB |
2945 | /* If X is a nontrivial arithmetic operation on an argument for which |
2946 | a constant value can be determined, return the result of operating | |
2947 | on that value, as a constant. Otherwise, return X, possibly with | |
2948 | one or more operands changed to a forward-propagated constant. | |
25910ca4 | 2949 | |
a52b023a PB |
2950 | If X is a register whose contents are known, we do NOT return |
2951 | those contents here; equiv_constant is called to perform that task. | |
2952 | For SUBREGs and MEMs, we do that both here and in equiv_constant. | |
7afe21cc RK |
2953 | |
2954 | INSN is the insn that we may be modifying. If it is 0, make a copy | |
2955 | of X before modifying it. */ | |
2956 | ||
2957 | static rtx | |
7080f735 | 2958 | fold_rtx (rtx x, rtx insn) |
7afe21cc | 2959 | { |
b3694847 SS |
2960 | enum rtx_code code; |
2961 | enum machine_mode mode; | |
2962 | const char *fmt; | |
2963 | int i; | |
7afe21cc | 2964 | rtx new = 0; |
a52b023a | 2965 | int changed = 0; |
7afe21cc | 2966 | |
a52b023a | 2967 | /* Operands of X. */ |
7afe21cc RK |
2968 | rtx folded_arg0; |
2969 | rtx folded_arg1; | |
2970 | ||
2971 | /* Constant equivalents of first three operands of X; | |
2972 | 0 when no such equivalent is known. */ | |
2973 | rtx const_arg0; | |
2974 | rtx const_arg1; | |
2975 | rtx const_arg2; | |
2976 | ||
2977 | /* The mode of the first operand of X. We need this for sign and zero | |
2978 | extends. */ | |
2979 | enum machine_mode mode_arg0; | |
2980 | ||
2981 | if (x == 0) | |
2982 | return x; | |
2983 | ||
a52b023a | 2984 | /* Try to perform some initial simplifications on X. */ |
7afe21cc RK |
2985 | code = GET_CODE (x); |
2986 | switch (code) | |
2987 | { | |
a52b023a PB |
2988 | case MEM: |
2989 | case SUBREG: | |
2990 | if ((new = equiv_constant (x)) != NULL_RTX) | |
2991 | return new; | |
2992 | return x; | |
2993 | ||
7afe21cc RK |
2994 | case CONST: |
2995 | case CONST_INT: | |
2996 | case CONST_DOUBLE: | |
69ef87e2 | 2997 | case CONST_VECTOR: |
7afe21cc RK |
2998 | case SYMBOL_REF: |
2999 | case LABEL_REF: | |
3000 | case REG: | |
01aa1d43 | 3001 | case PC: |
7afe21cc RK |
3002 | /* No use simplifying an EXPR_LIST |
3003 | since they are used only for lists of args | |
3004 | in a function call's REG_EQUAL note. */ | |
3005 | case EXPR_LIST: | |
3006 | return x; | |
3007 | ||
3008 | #ifdef HAVE_cc0 | |
3009 | case CC0: | |
3010 | return prev_insn_cc0; | |
3011 | #endif | |
3012 | ||
9255709c | 3013 | case ASM_OPERANDS: |
6c667859 AB |
3014 | if (insn) |
3015 | { | |
3016 | for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
3017 | validate_change (insn, &ASM_OPERANDS_INPUT (x, i), | |
3018 | fold_rtx (ASM_OPERANDS_INPUT (x, i), insn), 0); | |
3019 | } | |
a52b023a PB |
3020 | return x; |
3021 | ||
3022 | #ifdef NO_FUNCTION_CSE | |
3023 | case CALL: | |
3024 | if (CONSTANT_P (XEXP (XEXP (x, 0), 0))) | |
3025 | return x; | |
9255709c | 3026 | break; |
a52b023a | 3027 | #endif |
278a83b2 | 3028 | |
a52b023a | 3029 | /* Anything else goes through the loop below. */ |
e9a25f70 JL |
3030 | default: |
3031 | break; | |
7afe21cc RK |
3032 | } |
3033 | ||
a52b023a | 3034 | mode = GET_MODE (x); |
7afe21cc RK |
3035 | const_arg0 = 0; |
3036 | const_arg1 = 0; | |
3037 | const_arg2 = 0; | |
3038 | mode_arg0 = VOIDmode; | |
3039 | ||
3040 | /* Try folding our operands. | |
3041 | Then see which ones have constant values known. */ | |
3042 | ||
3043 | fmt = GET_RTX_FORMAT (code); | |
3044 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
3045 | if (fmt[i] == 'e') | |
3046 | { | |
a52b023a PB |
3047 | rtx folded_arg = XEXP (x, i), const_arg; |
3048 | enum machine_mode mode_arg = GET_MODE (folded_arg); | |
7e7e28c7 AO |
3049 | |
3050 | switch (GET_CODE (folded_arg)) | |
3051 | { | |
3052 | case MEM: | |
3053 | case REG: | |
3054 | case SUBREG: | |
3055 | const_arg = equiv_constant (folded_arg); | |
3056 | break; | |
3057 | ||
3058 | case CONST: | |
3059 | case CONST_INT: | |
3060 | case SYMBOL_REF: | |
3061 | case LABEL_REF: | |
3062 | case CONST_DOUBLE: | |
3063 | case CONST_VECTOR: | |
3064 | const_arg = folded_arg; | |
3065 | break; | |
3066 | ||
7afe21cc | 3067 | #ifdef HAVE_cc0 |
7e7e28c7 AO |
3068 | case CC0: |
3069 | folded_arg = prev_insn_cc0; | |
3070 | mode_arg = prev_insn_cc0_mode; | |
3071 | const_arg = equiv_constant (folded_arg); | |
3072 | break; | |
7afe21cc | 3073 | #endif |
7e7e28c7 AO |
3074 | |
3075 | default: | |
3076 | folded_arg = fold_rtx (folded_arg, insn); | |
3077 | const_arg = equiv_constant (folded_arg); | |
3078 | break; | |
3079 | } | |
7afe21cc RK |
3080 | |
3081 | /* For the first three operands, see if the operand | |
3082 | is constant or equivalent to a constant. */ | |
3083 | switch (i) | |
3084 | { | |
3085 | case 0: | |
3086 | folded_arg0 = folded_arg; | |
3087 | const_arg0 = const_arg; | |
3088 | mode_arg0 = mode_arg; | |
3089 | break; | |
3090 | case 1: | |
3091 | folded_arg1 = folded_arg; | |
3092 | const_arg1 = const_arg; | |
3093 | break; | |
3094 | case 2: | |
3095 | const_arg2 = const_arg; | |
3096 | break; | |
3097 | } | |
3098 | ||
a52b023a PB |
3099 | /* Pick the least expensive of the argument and an equivalent constant |
3100 | argument. */ | |
3101 | if (const_arg != 0 | |
3102 | && const_arg != folded_arg | |
3103 | && COST_IN (const_arg, code) <= COST_IN (folded_arg, code) | |
f2fa288f | 3104 | |
8cce3d04 RS |
3105 | /* It's not safe to substitute the operand of a conversion |
3106 | operator with a constant, as the conversion's identity | |
f652d14b | 3107 | depends upon the mode of its operand. This optimization |
8cce3d04 | 3108 | is handled by the call to simplify_unary_operation. */ |
a52b023a PB |
3109 | && (GET_RTX_CLASS (code) != RTX_UNARY |
3110 | || GET_MODE (const_arg) == mode_arg0 | |
3111 | || (code != ZERO_EXTEND | |
3112 | && code != SIGN_EXTEND | |
3113 | && code != TRUNCATE | |
3114 | && code != FLOAT_TRUNCATE | |
3115 | && code != FLOAT_EXTEND | |
3116 | && code != FLOAT | |
3117 | && code != FIX | |
3118 | && code != UNSIGNED_FLOAT | |
3119 | && code != UNSIGNED_FIX))) | |
3120 | folded_arg = const_arg; | |
3121 | ||
3122 | if (folded_arg == XEXP (x, i)) | |
3123 | continue; | |
7afe21cc | 3124 | |
a52b023a PB |
3125 | if (insn == NULL_RTX && !changed) |
3126 | x = copy_rtx (x); | |
3127 | changed = 1; | |
3128 | validate_change (insn, &XEXP (x, i), folded_arg, 1); | |
2d8b0f3a | 3129 | } |
7afe21cc | 3130 | |
a52b023a | 3131 | if (changed) |
7afe21cc | 3132 | { |
a52b023a PB |
3133 | /* Canonicalize X if necessary, and keep const_argN and folded_argN |
3134 | consistent with the order in X. */ | |
3135 | if (canonicalize_change_group (insn, x)) | |
7afe21cc | 3136 | { |
a52b023a PB |
3137 | rtx tem; |
3138 | tem = const_arg0, const_arg0 = const_arg1, const_arg1 = tem; | |
3139 | tem = folded_arg0, folded_arg0 = folded_arg1, folded_arg1 = tem; | |
7afe21cc | 3140 | } |
a52b023a PB |
3141 | |
3142 | apply_change_group (); | |
7afe21cc RK |
3143 | } |
3144 | ||
3145 | /* If X is an arithmetic operation, see if we can simplify it. */ | |
3146 | ||
3147 | switch (GET_RTX_CLASS (code)) | |
3148 | { | |
ec8e098d | 3149 | case RTX_UNARY: |
67a37737 RK |
3150 | { |
3151 | int is_const = 0; | |
3152 | ||
3153 | /* We can't simplify extension ops unless we know the | |
3154 | original mode. */ | |
3155 | if ((code == ZERO_EXTEND || code == SIGN_EXTEND) | |
3156 | && mode_arg0 == VOIDmode) | |
3157 | break; | |
3158 | ||
3159 | /* If we had a CONST, strip it off and put it back later if we | |
3160 | fold. */ | |
3161 | if (const_arg0 != 0 && GET_CODE (const_arg0) == CONST) | |
3162 | is_const = 1, const_arg0 = XEXP (const_arg0, 0); | |
3163 | ||
3164 | new = simplify_unary_operation (code, mode, | |
3165 | const_arg0 ? const_arg0 : folded_arg0, | |
3166 | mode_arg0); | |
ec666d23 JH |
3167 | /* NEG of PLUS could be converted into MINUS, but that causes |
3168 | expressions of the form | |
3169 | (CONST (MINUS (CONST_INT) (SYMBOL_REF))) | |
3170 | which many ports mistakenly treat as LEGITIMATE_CONSTANT_P. | |
3171 | FIXME: those ports should be fixed. */ | |
3172 | if (new != 0 && is_const | |
3173 | && GET_CODE (new) == PLUS | |
3174 | && (GET_CODE (XEXP (new, 0)) == SYMBOL_REF | |
3175 | || GET_CODE (XEXP (new, 0)) == LABEL_REF) | |
3176 | && GET_CODE (XEXP (new, 1)) == CONST_INT) | |
38a448ca | 3177 | new = gen_rtx_CONST (mode, new); |
67a37737 | 3178 | } |
7afe21cc | 3179 | break; |
278a83b2 | 3180 | |
ec8e098d PB |
3181 | case RTX_COMPARE: |
3182 | case RTX_COMM_COMPARE: | |
7afe21cc RK |
3183 | /* See what items are actually being compared and set FOLDED_ARG[01] |
3184 | to those values and CODE to the actual comparison code. If any are | |
3185 | constant, set CONST_ARG0 and CONST_ARG1 appropriately. We needn't | |
3186 | do anything if both operands are already known to be constant. */ | |
3187 | ||
21e5076a UB |
3188 | /* ??? Vector mode comparisons are not supported yet. */ |
3189 | if (VECTOR_MODE_P (mode)) | |
3190 | break; | |
3191 | ||
7afe21cc RK |
3192 | if (const_arg0 == 0 || const_arg1 == 0) |
3193 | { | |
3194 | struct table_elt *p0, *p1; | |
d6edb99e | 3195 | rtx true_rtx = const_true_rtx, false_rtx = const0_rtx; |
13c9910f | 3196 | enum machine_mode mode_arg1; |
c610adec RK |
3197 | |
3198 | #ifdef FLOAT_STORE_FLAG_VALUE | |
9b92bf04 | 3199 | if (SCALAR_FLOAT_MODE_P (mode)) |
c610adec | 3200 | { |
d6edb99e | 3201 | true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE |
68252e27 | 3202 | (FLOAT_STORE_FLAG_VALUE (mode), mode)); |
d6edb99e | 3203 | false_rtx = CONST0_RTX (mode); |
c610adec RK |
3204 | } |
3205 | #endif | |
7afe21cc | 3206 | |
13c9910f RS |
3207 | code = find_comparison_args (code, &folded_arg0, &folded_arg1, |
3208 | &mode_arg0, &mode_arg1); | |
7afe21cc | 3209 | |
13c9910f RS |
3210 | /* If the mode is VOIDmode or a MODE_CC mode, we don't know |
3211 | what kinds of things are being compared, so we can't do | |
3212 | anything with this comparison. */ | |
7afe21cc RK |
3213 | |
3214 | if (mode_arg0 == VOIDmode || GET_MODE_CLASS (mode_arg0) == MODE_CC) | |
3215 | break; | |
3216 | ||
75335440 KH |
3217 | const_arg0 = equiv_constant (folded_arg0); |
3218 | const_arg1 = equiv_constant (folded_arg1); | |
3219 | ||
0f41302f MS |
3220 | /* If we do not now have two constants being compared, see |
3221 | if we can nevertheless deduce some things about the | |
3222 | comparison. */ | |
7afe21cc RK |
3223 | if (const_arg0 == 0 || const_arg1 == 0) |
3224 | { | |
08678f51 HPN |
3225 | if (const_arg1 != NULL) |
3226 | { | |
3227 | rtx cheapest_simplification; | |
3228 | int cheapest_cost; | |
3229 | rtx simp_result; | |
3230 | struct table_elt *p; | |
3231 | ||
3232 | /* See if we can find an equivalent of folded_arg0 | |
3233 | that gets us a cheaper expression, possibly a | |
3234 | constant through simplifications. */ | |
3235 | p = lookup (folded_arg0, SAFE_HASH (folded_arg0, mode_arg0), | |
3236 | mode_arg0); | |
3237 | ||
3238 | if (p != NULL) | |
3239 | { | |
3240 | cheapest_simplification = x; | |
3241 | cheapest_cost = COST (x); | |
3242 | ||
3243 | for (p = p->first_same_value; p != NULL; p = p->next_same_value) | |
3244 | { | |
3245 | int cost; | |
3246 | ||
3247 | /* If the entry isn't valid, skip it. */ | |
3248 | if (! exp_equiv_p (p->exp, p->exp, 1, false)) | |
3249 | continue; | |
3250 | ||
3251 | /* Try to simplify using this equivalence. */ | |
3252 | simp_result | |
3253 | = simplify_relational_operation (code, mode, | |
3254 | mode_arg0, | |
3255 | p->exp, | |
3256 | const_arg1); | |
3257 | ||
3258 | if (simp_result == NULL) | |
3259 | continue; | |
3260 | ||
3261 | cost = COST (simp_result); | |
3262 | if (cost < cheapest_cost) | |
3263 | { | |
3264 | cheapest_cost = cost; | |
3265 | cheapest_simplification = simp_result; | |
3266 | } | |
3267 | } | |
3268 | ||
3269 | /* If we have a cheaper expression now, use that | |
3270 | and try folding it further, from the top. */ | |
3271 | if (cheapest_simplification != x) | |
3272 | return fold_rtx (cheapest_simplification, insn); | |
3273 | } | |
3274 | } | |
3275 | ||
4977bab6 ZW |
3276 | /* Some addresses are known to be nonzero. We don't know |
3277 | their sign, but equality comparisons are known. */ | |
7afe21cc | 3278 | if (const_arg1 == const0_rtx |
4977bab6 | 3279 | && nonzero_address_p (folded_arg0)) |
7afe21cc RK |
3280 | { |
3281 | if (code == EQ) | |
d6edb99e | 3282 | return false_rtx; |
7afe21cc | 3283 | else if (code == NE) |
d6edb99e | 3284 | return true_rtx; |
7afe21cc RK |
3285 | } |
3286 | ||
fd13313f JH |
3287 | /* See if the two operands are the same. */ |
3288 | ||
3289 | if (folded_arg0 == folded_arg1 | |
f8cfc6aa JQ |
3290 | || (REG_P (folded_arg0) |
3291 | && REG_P (folded_arg1) | |
fd13313f JH |
3292 | && (REG_QTY (REGNO (folded_arg0)) |
3293 | == REG_QTY (REGNO (folded_arg1)))) | |
3294 | || ((p0 = lookup (folded_arg0, | |
0516f6fe SB |
3295 | SAFE_HASH (folded_arg0, mode_arg0), |
3296 | mode_arg0)) | |
fd13313f | 3297 | && (p1 = lookup (folded_arg1, |
0516f6fe SB |
3298 | SAFE_HASH (folded_arg1, mode_arg0), |
3299 | mode_arg0)) | |
fd13313f JH |
3300 | && p0->first_same_value == p1->first_same_value)) |
3301 | { | |
71925bc0 RS |
3302 | /* Sadly two equal NaNs are not equivalent. */ |
3303 | if (!HONOR_NANS (mode_arg0)) | |
3304 | return ((code == EQ || code == LE || code == GE | |
3305 | || code == LEU || code == GEU || code == UNEQ | |
3306 | || code == UNLE || code == UNGE | |
3307 | || code == ORDERED) | |
3308 | ? true_rtx : false_rtx); | |
3309 | /* Take care for the FP compares we can resolve. */ | |
3310 | if (code == UNEQ || code == UNLE || code == UNGE) | |
3311 | return true_rtx; | |
3312 | if (code == LTGT || code == LT || code == GT) | |
3313 | return false_rtx; | |
fd13313f | 3314 | } |
7afe21cc RK |
3315 | |
3316 | /* If FOLDED_ARG0 is a register, see if the comparison we are | |
3317 | doing now is either the same as we did before or the reverse | |
3318 | (we only check the reverse if not floating-point). */ | |
f8cfc6aa | 3319 | else if (REG_P (folded_arg0)) |
7afe21cc | 3320 | { |
30f72379 | 3321 | int qty = REG_QTY (REGNO (folded_arg0)); |
7afe21cc | 3322 | |
1bb98cec DM |
3323 | if (REGNO_QTY_VALID_P (REGNO (folded_arg0))) |
3324 | { | |
3325 | struct qty_table_elem *ent = &qty_table[qty]; | |
3326 | ||
3327 | if ((comparison_dominates_p (ent->comparison_code, code) | |
1eb8759b RH |
3328 | || (! FLOAT_MODE_P (mode_arg0) |
3329 | && comparison_dominates_p (ent->comparison_code, | |
3330 | reverse_condition (code)))) | |
1bb98cec DM |
3331 | && (rtx_equal_p (ent->comparison_const, folded_arg1) |
3332 | || (const_arg1 | |
3333 | && rtx_equal_p (ent->comparison_const, | |
3334 | const_arg1)) | |
f8cfc6aa | 3335 | || (REG_P (folded_arg1) |
1bb98cec DM |
3336 | && (REG_QTY (REGNO (folded_arg1)) == ent->comparison_qty)))) |
3337 | return (comparison_dominates_p (ent->comparison_code, code) | |
d6edb99e | 3338 | ? true_rtx : false_rtx); |
1bb98cec | 3339 | } |
7afe21cc RK |
3340 | } |
3341 | } | |
3342 | } | |
3343 | ||
3344 | /* If we are comparing against zero, see if the first operand is | |
3345 | equivalent to an IOR with a constant. If so, we may be able to | |
3346 | determine the result of this comparison. */ | |
3347 | ||
3348 | if (const_arg1 == const0_rtx) | |
3349 | { | |
3350 | rtx y = lookup_as_function (folded_arg0, IOR); | |
3351 | rtx inner_const; | |
3352 | ||
3353 | if (y != 0 | |
3354 | && (inner_const = equiv_constant (XEXP (y, 1))) != 0 | |
3355 | && GET_CODE (inner_const) == CONST_INT | |
3356 | && INTVAL (inner_const) != 0) | |
3357 | { | |
3358 | int sign_bitnum = GET_MODE_BITSIZE (mode_arg0) - 1; | |
906c4e36 RK |
3359 | int has_sign = (HOST_BITS_PER_WIDE_INT >= sign_bitnum |
3360 | && (INTVAL (inner_const) | |
3361 | & ((HOST_WIDE_INT) 1 << sign_bitnum))); | |
d6edb99e | 3362 | rtx true_rtx = const_true_rtx, false_rtx = const0_rtx; |
c610adec RK |
3363 | |
3364 | #ifdef FLOAT_STORE_FLAG_VALUE | |
3d8bf70f | 3365 | if (SCALAR_FLOAT_MODE_P (mode)) |
c610adec | 3366 | { |
d6edb99e | 3367 | true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE |
12530dbe | 3368 | (FLOAT_STORE_FLAG_VALUE (mode), mode)); |
d6edb99e | 3369 | false_rtx = CONST0_RTX (mode); |
c610adec RK |
3370 | } |
3371 | #endif | |
7afe21cc RK |
3372 | |
3373 | switch (code) | |
3374 | { | |
3375 | case EQ: | |
d6edb99e | 3376 | return false_rtx; |
7afe21cc | 3377 | case NE: |
d6edb99e | 3378 | return true_rtx; |
7afe21cc RK |
3379 | case LT: case LE: |
3380 | if (has_sign) | |
d6edb99e | 3381 | return true_rtx; |
7afe21cc RK |
3382 | break; |
3383 | case GT: case GE: | |
3384 | if (has_sign) | |
d6edb99e | 3385 | return false_rtx; |
7afe21cc | 3386 | break; |
e9a25f70 JL |
3387 | default: |
3388 | break; | |
7afe21cc RK |
3389 | } |
3390 | } | |
3391 | } | |
3392 | ||
c6fb08ad PB |
3393 | { |
3394 | rtx op0 = const_arg0 ? const_arg0 : folded_arg0; | |
3395 | rtx op1 = const_arg1 ? const_arg1 : folded_arg1; | |
3396 | new = simplify_relational_operation (code, mode, mode_arg0, op0, op1); | |
3397 | } | |
7afe21cc RK |
3398 | break; |
3399 | ||
ec8e098d PB |
3400 | case RTX_BIN_ARITH: |
3401 | case RTX_COMM_ARITH: | |
7afe21cc RK |
3402 | switch (code) |
3403 | { | |
3404 | case PLUS: | |
3405 | /* If the second operand is a LABEL_REF, see if the first is a MINUS | |
3406 | with that LABEL_REF as its second operand. If so, the result is | |
3407 | the first operand of that MINUS. This handles switches with an | |
3408 | ADDR_DIFF_VEC table. */ | |
3409 | if (const_arg1 && GET_CODE (const_arg1) == LABEL_REF) | |
3410 | { | |
e650cbda RK |
3411 | rtx y |
3412 | = GET_CODE (folded_arg0) == MINUS ? folded_arg0 | |
ddc356e8 | 3413 | : lookup_as_function (folded_arg0, MINUS); |
7afe21cc RK |
3414 | |
3415 | if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF | |
3416 | && XEXP (XEXP (y, 1), 0) == XEXP (const_arg1, 0)) | |
3417 | return XEXP (y, 0); | |
67a37737 RK |
3418 | |
3419 | /* Now try for a CONST of a MINUS like the above. */ | |
e650cbda RK |
3420 | if ((y = (GET_CODE (folded_arg0) == CONST ? folded_arg0 |
3421 | : lookup_as_function (folded_arg0, CONST))) != 0 | |
67a37737 RK |
3422 | && GET_CODE (XEXP (y, 0)) == MINUS |
3423 | && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF | |
ddc356e8 | 3424 | && XEXP (XEXP (XEXP (y, 0), 1), 0) == XEXP (const_arg1, 0)) |
67a37737 | 3425 | return XEXP (XEXP (y, 0), 0); |
7afe21cc | 3426 | } |
c2cc0778 | 3427 | |
e650cbda RK |
3428 | /* Likewise if the operands are in the other order. */ |
3429 | if (const_arg0 && GET_CODE (const_arg0) == LABEL_REF) | |
3430 | { | |
3431 | rtx y | |
3432 | = GET_CODE (folded_arg1) == MINUS ? folded_arg1 | |
ddc356e8 | 3433 | : lookup_as_function (folded_arg1, MINUS); |
e650cbda RK |
3434 | |
3435 | if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF | |
3436 | && XEXP (XEXP (y, 1), 0) == XEXP (const_arg0, 0)) | |
3437 | return XEXP (y, 0); | |
3438 | ||
3439 | /* Now try for a CONST of a MINUS like the above. */ | |
3440 | if ((y = (GET_CODE (folded_arg1) == CONST ? folded_arg1 | |
3441 | : lookup_as_function (folded_arg1, CONST))) != 0 | |
3442 | && GET_CODE (XEXP (y, 0)) == MINUS | |
3443 | && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF | |
ddc356e8 | 3444 | && XEXP (XEXP (XEXP (y, 0), 1), 0) == XEXP (const_arg0, 0)) |
e650cbda RK |
3445 | return XEXP (XEXP (y, 0), 0); |
3446 | } | |
3447 | ||
c2cc0778 RK |
3448 | /* If second operand is a register equivalent to a negative |
3449 | CONST_INT, see if we can find a register equivalent to the | |
3450 | positive constant. Make a MINUS if so. Don't do this for | |
5d595063 | 3451 | a non-negative constant since we might then alternate between |
a1f300c0 | 3452 | choosing positive and negative constants. Having the positive |
5d595063 RK |
3453 | constant previously-used is the more common case. Be sure |
3454 | the resulting constant is non-negative; if const_arg1 were | |
3455 | the smallest negative number this would overflow: depending | |
3456 | on the mode, this would either just be the same value (and | |
3457 | hence not save anything) or be incorrect. */ | |
3458 | if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT | |
3459 | && INTVAL (const_arg1) < 0 | |
4741f6ad JL |
3460 | /* This used to test |
3461 | ||
ddc356e8 | 3462 | -INTVAL (const_arg1) >= 0 |
4741f6ad JL |
3463 | |
3464 | But The Sun V5.0 compilers mis-compiled that test. So | |
3465 | instead we test for the problematic value in a more direct | |
3466 | manner and hope the Sun compilers get it correct. */ | |
5c45a8ac KG |
3467 | && INTVAL (const_arg1) != |
3468 | ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)) | |
f8cfc6aa | 3469 | && REG_P (folded_arg1)) |
c2cc0778 | 3470 | { |
ddc356e8 | 3471 | rtx new_const = GEN_INT (-INTVAL (const_arg1)); |
c2cc0778 | 3472 | struct table_elt *p |
0516f6fe | 3473 | = lookup (new_const, SAFE_HASH (new_const, mode), mode); |
c2cc0778 RK |
3474 | |
3475 | if (p) | |
3476 | for (p = p->first_same_value; p; p = p->next_same_value) | |
f8cfc6aa | 3477 | if (REG_P (p->exp)) |
0cedb36c JL |
3478 | return simplify_gen_binary (MINUS, mode, folded_arg0, |
3479 | canon_reg (p->exp, NULL_RTX)); | |
c2cc0778 | 3480 | } |
13c9910f RS |
3481 | goto from_plus; |
3482 | ||
3483 | case MINUS: | |
3484 | /* If we have (MINUS Y C), see if Y is known to be (PLUS Z C2). | |
3485 | If so, produce (PLUS Z C2-C). */ | |
3486 | if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT) | |
3487 | { | |
3488 | rtx y = lookup_as_function (XEXP (x, 0), PLUS); | |
3489 | if (y && GET_CODE (XEXP (y, 1)) == CONST_INT) | |
f3becefd RK |
3490 | return fold_rtx (plus_constant (copy_rtx (y), |
3491 | -INTVAL (const_arg1)), | |
a3b5c94a | 3492 | NULL_RTX); |
13c9910f | 3493 | } |
7afe21cc | 3494 | |
ddc356e8 | 3495 | /* Fall through. */ |
7afe21cc | 3496 | |
13c9910f | 3497 | from_plus: |
7afe21cc RK |
3498 | case SMIN: case SMAX: case UMIN: case UMAX: |
3499 | case IOR: case AND: case XOR: | |
f930bfd0 | 3500 | case MULT: |
7afe21cc RK |
3501 | case ASHIFT: case LSHIFTRT: case ASHIFTRT: |
3502 | /* If we have (<op> <reg> <const_int>) for an associative OP and REG | |
3503 | is known to be of similar form, we may be able to replace the | |
3504 | operation with a combined operation. This may eliminate the | |
3505 | intermediate operation if every use is simplified in this way. | |
3506 | Note that the similar optimization done by combine.c only works | |
3507 | if the intermediate operation's result has only one reference. */ | |
3508 | ||
f8cfc6aa | 3509 | if (REG_P (folded_arg0) |
7afe21cc RK |
3510 | && const_arg1 && GET_CODE (const_arg1) == CONST_INT) |
3511 | { | |
3512 | int is_shift | |
3513 | = (code == ASHIFT || code == ASHIFTRT || code == LSHIFTRT); | |
5bb51e1d | 3514 | rtx y, inner_const, new_const; |
7afe21cc | 3515 | enum rtx_code associate_code; |
7afe21cc | 3516 | |
824a4527 JDA |
3517 | if (is_shift |
3518 | && (INTVAL (const_arg1) >= GET_MODE_BITSIZE (mode) | |
3519 | || INTVAL (const_arg1) < 0)) | |
3520 | { | |
3521 | if (SHIFT_COUNT_TRUNCATED) | |
3522 | const_arg1 = GEN_INT (INTVAL (const_arg1) | |
3523 | & (GET_MODE_BITSIZE (mode) - 1)); | |
3524 | else | |
3525 | break; | |
3526 | } | |
3527 | ||
5bb51e1d | 3528 | y = lookup_as_function (folded_arg0, code); |
824a4527 JDA |
3529 | if (y == 0) |
3530 | break; | |
824a4527 JDA |
3531 | |
3532 | /* If we have compiled a statement like | |
3533 | "if (x == (x & mask1))", and now are looking at | |
3534 | "x & mask2", we will have a case where the first operand | |
3535 | of Y is the same as our first operand. Unless we detect | |
3536 | this case, an infinite loop will result. */ | |
3537 | if (XEXP (y, 0) == folded_arg0) | |
7afe21cc RK |
3538 | break; |
3539 | ||
5bb51e1d EB |
3540 | inner_const = equiv_constant (fold_rtx (XEXP (y, 1), 0)); |
3541 | if (!inner_const || GET_CODE (inner_const) != CONST_INT) | |
3542 | break; | |
3543 | ||
7afe21cc RK |
3544 | /* Don't associate these operations if they are a PLUS with the |
3545 | same constant and it is a power of two. These might be doable | |
3546 | with a pre- or post-increment. Similarly for two subtracts of | |
3547 | identical powers of two with post decrement. */ | |
3548 | ||
213d5fbc | 3549 | if (code == PLUS && const_arg1 == inner_const |
940da324 JL |
3550 | && ((HAVE_PRE_INCREMENT |
3551 | && exact_log2 (INTVAL (const_arg1)) >= 0) | |
3552 | || (HAVE_POST_INCREMENT | |
3553 | && exact_log2 (INTVAL (const_arg1)) >= 0) | |
3554 | || (HAVE_PRE_DECREMENT | |
3555 | && exact_log2 (- INTVAL (const_arg1)) >= 0) | |
3556 | || (HAVE_POST_DECREMENT | |
3557 | && exact_log2 (- INTVAL (const_arg1)) >= 0))) | |
7afe21cc RK |
3558 | break; |
3559 | ||
824a4527 JDA |
3560 | if (is_shift |
3561 | && (INTVAL (inner_const) >= GET_MODE_BITSIZE (mode) | |
3562 | || INTVAL (inner_const) < 0)) | |
3563 | { | |
3564 | if (SHIFT_COUNT_TRUNCATED) | |
3565 | inner_const = GEN_INT (INTVAL (inner_const) | |
3566 | & (GET_MODE_BITSIZE (mode) - 1)); | |
3567 | else | |
3568 | break; | |
3569 | } | |
3570 | ||
7afe21cc | 3571 | /* Compute the code used to compose the constants. For example, |
f930bfd0 | 3572 | A-C1-C2 is A-(C1 + C2), so if CODE == MINUS, we want PLUS. */ |
7afe21cc | 3573 | |
f930bfd0 | 3574 | associate_code = (is_shift || code == MINUS ? PLUS : code); |
7afe21cc RK |
3575 | |
3576 | new_const = simplify_binary_operation (associate_code, mode, | |
3577 | const_arg1, inner_const); | |
3578 | ||
3579 | if (new_const == 0) | |
3580 | break; | |
3581 | ||
3582 | /* If we are associating shift operations, don't let this | |
4908e508 RS |
3583 | produce a shift of the size of the object or larger. |
3584 | This could occur when we follow a sign-extend by a right | |
3585 | shift on a machine that does a sign-extend as a pair | |
3586 | of shifts. */ | |
7afe21cc | 3587 | |
824a4527 JDA |
3588 | if (is_shift |
3589 | && GET_CODE (new_const) == CONST_INT | |
4908e508 RS |
3590 | && INTVAL (new_const) >= GET_MODE_BITSIZE (mode)) |
3591 | { | |
3592 | /* As an exception, we can turn an ASHIFTRT of this | |
3593 | form into a shift of the number of bits - 1. */ | |
3594 | if (code == ASHIFTRT) | |
3595 | new_const = GEN_INT (GET_MODE_BITSIZE (mode) - 1); | |
824a4527 JDA |
3596 | else if (!side_effects_p (XEXP (y, 0))) |
3597 | return CONST0_RTX (mode); | |
4908e508 RS |
3598 | else |
3599 | break; | |
3600 | } | |
7afe21cc RK |
3601 | |
3602 | y = copy_rtx (XEXP (y, 0)); | |
3603 | ||
3604 | /* If Y contains our first operand (the most common way this | |
3605 | can happen is if Y is a MEM), we would do into an infinite | |
3606 | loop if we tried to fold it. So don't in that case. */ | |
3607 | ||
3608 | if (! reg_mentioned_p (folded_arg0, y)) | |
3609 | y = fold_rtx (y, insn); | |
3610 | ||
0cedb36c | 3611 | return simplify_gen_binary (code, mode, y, new_const); |
7afe21cc | 3612 | } |
e9a25f70 JL |
3613 | break; |
3614 | ||
f930bfd0 JW |
3615 | case DIV: case UDIV: |
3616 | /* ??? The associative optimization performed immediately above is | |
3617 | also possible for DIV and UDIV using associate_code of MULT. | |
3618 | However, we would need extra code to verify that the | |
3619 | multiplication does not overflow, that is, there is no overflow | |
3620 | in the calculation of new_const. */ | |
3621 | break; | |
3622 | ||
e9a25f70 JL |
3623 | default: |
3624 | break; | |
7afe21cc RK |
3625 | } |
3626 | ||
3627 | new = simplify_binary_operation (code, mode, | |
3628 | const_arg0 ? const_arg0 : folded_arg0, | |
3629 | const_arg1 ? const_arg1 : folded_arg1); | |
3630 | break; | |
3631 | ||
ec8e098d | 3632 | case RTX_OBJ: |
7afe21cc RK |
3633 | /* (lo_sum (high X) X) is simply X. */ |
3634 | if (code == LO_SUM && const_arg0 != 0 | |
3635 | && GET_CODE (const_arg0) == HIGH | |
3636 | && rtx_equal_p (XEXP (const_arg0, 0), const_arg1)) | |
3637 | return const_arg1; | |
3638 | break; | |
3639 | ||
ec8e098d PB |
3640 | case RTX_TERNARY: |
3641 | case RTX_BITFIELD_OPS: | |
7afe21cc RK |
3642 | new = simplify_ternary_operation (code, mode, mode_arg0, |
3643 | const_arg0 ? const_arg0 : folded_arg0, | |
3644 | const_arg1 ? const_arg1 : folded_arg1, | |
3645 | const_arg2 ? const_arg2 : XEXP (x, 2)); | |
3646 | break; | |
ee5332b8 | 3647 | |
ec8e098d PB |
3648 | default: |
3649 | break; | |
7afe21cc RK |
3650 | } |
3651 | ||
3652 | return new ? new : x; | |
3653 | } | |
3654 | \f | |
3655 | /* Return a constant value currently equivalent to X. | |
3656 | Return 0 if we don't know one. */ | |
3657 | ||
3658 | static rtx | |
7080f735 | 3659 | equiv_constant (rtx x) |
7afe21cc | 3660 | { |
f8cfc6aa | 3661 | if (REG_P (x) |
1bb98cec DM |
3662 | && REGNO_QTY_VALID_P (REGNO (x))) |
3663 | { | |
3664 | int x_q = REG_QTY (REGNO (x)); | |
3665 | struct qty_table_elem *x_ent = &qty_table[x_q]; | |
3666 | ||
3667 | if (x_ent->const_rtx) | |
4de249d9 | 3668 | x = gen_lowpart (GET_MODE (x), x_ent->const_rtx); |
1bb98cec | 3669 | } |
7afe21cc | 3670 | |
2ce5e1b4 | 3671 | if (x == 0 || CONSTANT_P (x)) |
7afe21cc RK |
3672 | return x; |
3673 | ||
a52b023a PB |
3674 | if (GET_CODE (x) == SUBREG) |
3675 | { | |
3676 | rtx new; | |
3677 | ||
3678 | /* See if we previously assigned a constant value to this SUBREG. */ | |
3679 | if ((new = lookup_as_function (x, CONST_INT)) != 0 | |
3680 | || (new = lookup_as_function (x, CONST_DOUBLE)) != 0) | |
3681 | return new; | |
3682 | ||
3683 | if (REG_P (SUBREG_REG (x)) | |
3684 | && (new = equiv_constant (SUBREG_REG (x))) != 0) | |
3685 | return simplify_subreg (GET_MODE (x), SUBREG_REG (x), | |
3686 | GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x)); | |
3687 | ||
3688 | return 0; | |
3689 | } | |
3690 | ||
3691 | /* If X is a MEM, see if it is a constant-pool reference, or look it up in | |
3692 | the hash table in case its value was seen before. */ | |
fc3ffe83 | 3693 | |
3c0cb5de | 3694 | if (MEM_P (x)) |
fc3ffe83 RK |
3695 | { |
3696 | struct table_elt *elt; | |
3697 | ||
a52b023a | 3698 | x = avoid_constant_pool_reference (x); |
fc3ffe83 RK |
3699 | if (CONSTANT_P (x)) |
3700 | return x; | |
3701 | ||
0516f6fe | 3702 | elt = lookup (x, SAFE_HASH (x, GET_MODE (x)), GET_MODE (x)); |
fc3ffe83 RK |
3703 | if (elt == 0) |
3704 | return 0; | |
3705 | ||
3706 | for (elt = elt->first_same_value; elt; elt = elt->next_same_value) | |
3707 | if (elt->is_const && CONSTANT_P (elt->exp)) | |
3708 | return elt->exp; | |
3709 | } | |
3710 | ||
7afe21cc RK |
3711 | return 0; |
3712 | } | |
3713 | \f | |
0129d079 SB |
3714 | /* Given INSN, a jump insn, TAKEN indicates if we are following the |
3715 | "taken" branch. | |
7afe21cc RK |
3716 | |
3717 | In certain cases, this can cause us to add an equivalence. For example, | |
278a83b2 | 3718 | if we are following the taken case of |
7080f735 | 3719 | if (i == 2) |
7afe21cc RK |
3720 | we can add the fact that `i' and '2' are now equivalent. |
3721 | ||
3722 | In any case, we can record that this comparison was passed. If the same | |
3723 | comparison is seen later, we will know its value. */ | |
3724 | ||
3725 | static void | |
0129d079 | 3726 | record_jump_equiv (rtx insn, bool taken) |
7afe21cc RK |
3727 | { |
3728 | int cond_known_true; | |
3729 | rtx op0, op1; | |
7f1c097d | 3730 | rtx set; |
13c9910f | 3731 | enum machine_mode mode, mode0, mode1; |
7afe21cc RK |
3732 | int reversed_nonequality = 0; |
3733 | enum rtx_code code; | |
3734 | ||
3735 | /* Ensure this is the right kind of insn. */ | |
0129d079 SB |
3736 | gcc_assert (any_condjump_p (insn)); |
3737 | ||
7f1c097d | 3738 | set = pc_set (insn); |
7afe21cc RK |
3739 | |
3740 | /* See if this jump condition is known true or false. */ | |
3741 | if (taken) | |
7f1c097d | 3742 | cond_known_true = (XEXP (SET_SRC (set), 2) == pc_rtx); |
7afe21cc | 3743 | else |
7f1c097d | 3744 | cond_known_true = (XEXP (SET_SRC (set), 1) == pc_rtx); |
7afe21cc RK |
3745 | |
3746 | /* Get the type of comparison being done and the operands being compared. | |
3747 | If we had to reverse a non-equality condition, record that fact so we | |
3748 | know that it isn't valid for floating-point. */ | |
7f1c097d JH |
3749 | code = GET_CODE (XEXP (SET_SRC (set), 0)); |
3750 | op0 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 0), insn); | |
3751 | op1 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 1), insn); | |
7afe21cc | 3752 | |
13c9910f | 3753 | code = find_comparison_args (code, &op0, &op1, &mode0, &mode1); |
7afe21cc RK |
3754 | if (! cond_known_true) |
3755 | { | |
261efdef | 3756 | code = reversed_comparison_code_parts (code, op0, op1, insn); |
1eb8759b RH |
3757 | |
3758 | /* Don't remember if we can't find the inverse. */ | |
3759 | if (code == UNKNOWN) | |
3760 | return; | |
7afe21cc RK |
3761 | } |
3762 | ||
3763 | /* The mode is the mode of the non-constant. */ | |
13c9910f RS |
3764 | mode = mode0; |
3765 | if (mode1 != VOIDmode) | |
3766 | mode = mode1; | |
7afe21cc RK |
3767 | |
3768 | record_jump_cond (code, mode, op0, op1, reversed_nonequality); | |
3769 | } | |
3770 | ||
794693c0 RH |
3771 | /* Yet another form of subreg creation. In this case, we want something in |
3772 | MODE, and we should assume OP has MODE iff it is naturally modeless. */ | |
3773 | ||
3774 | static rtx | |
3775 | record_jump_cond_subreg (enum machine_mode mode, rtx op) | |
3776 | { | |
3777 | enum machine_mode op_mode = GET_MODE (op); | |
3778 | if (op_mode == mode || op_mode == VOIDmode) | |
3779 | return op; | |
3780 | return lowpart_subreg (mode, op, op_mode); | |
3781 | } | |
3782 | ||
7afe21cc RK |
3783 | /* We know that comparison CODE applied to OP0 and OP1 in MODE is true. |
3784 | REVERSED_NONEQUALITY is nonzero if CODE had to be swapped. | |
3785 | Make any useful entries we can with that information. Called from | |
3786 | above function and called recursively. */ | |
3787 | ||
3788 | static void | |
7080f735 AJ |
3789 | record_jump_cond (enum rtx_code code, enum machine_mode mode, rtx op0, |
3790 | rtx op1, int reversed_nonequality) | |
7afe21cc | 3791 | { |
2197a88a | 3792 | unsigned op0_hash, op1_hash; |
e428d738 | 3793 | int op0_in_memory, op1_in_memory; |
7afe21cc RK |
3794 | struct table_elt *op0_elt, *op1_elt; |
3795 | ||
3796 | /* If OP0 and OP1 are known equal, and either is a paradoxical SUBREG, | |
3797 | we know that they are also equal in the smaller mode (this is also | |
3798 | true for all smaller modes whether or not there is a SUBREG, but | |
ac7ef8d5 | 3799 | is not worth testing for with no SUBREG). */ |
7afe21cc | 3800 | |
2e794ee8 | 3801 | /* Note that GET_MODE (op0) may not equal MODE. */ |
7afe21cc | 3802 | if (code == EQ && GET_CODE (op0) == SUBREG |
2e794ee8 RS |
3803 | && (GET_MODE_SIZE (GET_MODE (op0)) |
3804 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) | |
7afe21cc RK |
3805 | { |
3806 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); | |
794693c0 RH |
3807 | rtx tem = record_jump_cond_subreg (inner_mode, op1); |
3808 | if (tem) | |
3809 | record_jump_cond (code, mode, SUBREG_REG (op0), tem, | |
3810 | reversed_nonequality); | |
7afe21cc RK |
3811 | } |
3812 | ||
3813 | if (code == EQ && GET_CODE (op1) == SUBREG | |
2e794ee8 RS |
3814 | && (GET_MODE_SIZE (GET_MODE (op1)) |
3815 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) | |
7afe21cc RK |
3816 | { |
3817 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); | |
794693c0 RH |
3818 | rtx tem = record_jump_cond_subreg (inner_mode, op0); |
3819 | if (tem) | |
3820 | record_jump_cond (code, mode, SUBREG_REG (op1), tem, | |
3821 | reversed_nonequality); | |
7afe21cc RK |
3822 | } |
3823 | ||
278a83b2 | 3824 | /* Similarly, if this is an NE comparison, and either is a SUBREG |
7afe21cc RK |
3825 | making a smaller mode, we know the whole thing is also NE. */ |
3826 | ||
2e794ee8 RS |
3827 | /* Note that GET_MODE (op0) may not equal MODE; |
3828 | if we test MODE instead, we can get an infinite recursion | |
3829 | alternating between two modes each wider than MODE. */ | |
3830 | ||
7afe21cc RK |
3831 | if (code == NE && GET_CODE (op0) == SUBREG |
3832 | && subreg_lowpart_p (op0) | |
2e794ee8 RS |
3833 | && (GET_MODE_SIZE (GET_MODE (op0)) |
3834 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) | |
7afe21cc RK |
3835 | { |
3836 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); | |
794693c0 RH |
3837 | rtx tem = record_jump_cond_subreg (inner_mode, op1); |
3838 | if (tem) | |
3839 | record_jump_cond (code, mode, SUBREG_REG (op0), tem, | |
3840 | reversed_nonequality); | |
7afe21cc RK |
3841 | } |
3842 | ||
3843 | if (code == NE && GET_CODE (op1) == SUBREG | |
3844 | && subreg_lowpart_p (op1) | |
2e794ee8 RS |
3845 | && (GET_MODE_SIZE (GET_MODE (op1)) |
3846 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) | |
7afe21cc RK |
3847 | { |
3848 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); | |
794693c0 RH |
3849 | rtx tem = record_jump_cond_subreg (inner_mode, op0); |
3850 | if (tem) | |
3851 | record_jump_cond (code, mode, SUBREG_REG (op1), tem, | |
3852 | reversed_nonequality); | |
7afe21cc RK |
3853 | } |
3854 | ||
3855 | /* Hash both operands. */ | |
3856 | ||
3857 | do_not_record = 0; | |
3858 | hash_arg_in_memory = 0; | |
2197a88a | 3859 | op0_hash = HASH (op0, mode); |
7afe21cc | 3860 | op0_in_memory = hash_arg_in_memory; |
7afe21cc RK |
3861 | |
3862 | if (do_not_record) | |
3863 | return; | |
3864 | ||
3865 | do_not_record = 0; | |
3866 | hash_arg_in_memory = 0; | |
2197a88a | 3867 | op1_hash = HASH (op1, mode); |
7afe21cc | 3868 | op1_in_memory = hash_arg_in_memory; |
278a83b2 | 3869 | |
7afe21cc RK |
3870 | if (do_not_record) |
3871 | return; | |
3872 | ||
3873 | /* Look up both operands. */ | |
2197a88a RK |
3874 | op0_elt = lookup (op0, op0_hash, mode); |
3875 | op1_elt = lookup (op1, op1_hash, mode); | |
7afe21cc | 3876 | |
af3869c1 RK |
3877 | /* If both operands are already equivalent or if they are not in the |
3878 | table but are identical, do nothing. */ | |
3879 | if ((op0_elt != 0 && op1_elt != 0 | |
3880 | && op0_elt->first_same_value == op1_elt->first_same_value) | |
3881 | || op0 == op1 || rtx_equal_p (op0, op1)) | |
3882 | return; | |
3883 | ||
7afe21cc | 3884 | /* If we aren't setting two things equal all we can do is save this |
b2796a4b RK |
3885 | comparison. Similarly if this is floating-point. In the latter |
3886 | case, OP1 might be zero and both -0.0 and 0.0 are equal to it. | |
3887 | If we record the equality, we might inadvertently delete code | |
3888 | whose intent was to change -0 to +0. */ | |
3889 | ||
cbf6a543 | 3890 | if (code != EQ || FLOAT_MODE_P (GET_MODE (op0))) |
7afe21cc | 3891 | { |
1bb98cec DM |
3892 | struct qty_table_elem *ent; |
3893 | int qty; | |
3894 | ||
7afe21cc RK |
3895 | /* If we reversed a floating-point comparison, if OP0 is not a |
3896 | register, or if OP1 is neither a register or constant, we can't | |
3897 | do anything. */ | |
3898 | ||
f8cfc6aa | 3899 | if (!REG_P (op1)) |
7afe21cc RK |
3900 | op1 = equiv_constant (op1); |
3901 | ||
cbf6a543 | 3902 | if ((reversed_nonequality && FLOAT_MODE_P (mode)) |
f8cfc6aa | 3903 | || !REG_P (op0) || op1 == 0) |
7afe21cc RK |
3904 | return; |
3905 | ||
3906 | /* Put OP0 in the hash table if it isn't already. This gives it a | |
3907 | new quantity number. */ | |
3908 | if (op0_elt == 0) | |
3909 | { | |
9714cf43 | 3910 | if (insert_regs (op0, NULL, 0)) |
7afe21cc RK |
3911 | { |
3912 | rehash_using_reg (op0); | |
2197a88a | 3913 | op0_hash = HASH (op0, mode); |
2bb81c86 RK |
3914 | |
3915 | /* If OP0 is contained in OP1, this changes its hash code | |
3916 | as well. Faster to rehash than to check, except | |
3917 | for the simple case of a constant. */ | |
3918 | if (! CONSTANT_P (op1)) | |
2197a88a | 3919 | op1_hash = HASH (op1,mode); |
7afe21cc RK |
3920 | } |
3921 | ||
9714cf43 | 3922 | op0_elt = insert (op0, NULL, op0_hash, mode); |
7afe21cc | 3923 | op0_elt->in_memory = op0_in_memory; |
7afe21cc RK |
3924 | } |
3925 | ||
1bb98cec DM |
3926 | qty = REG_QTY (REGNO (op0)); |
3927 | ent = &qty_table[qty]; | |
3928 | ||
3929 | ent->comparison_code = code; | |
f8cfc6aa | 3930 | if (REG_P (op1)) |
7afe21cc | 3931 | { |
5d5ea909 | 3932 | /* Look it up again--in case op0 and op1 are the same. */ |
2197a88a | 3933 | op1_elt = lookup (op1, op1_hash, mode); |
5d5ea909 | 3934 | |
7afe21cc RK |
3935 | /* Put OP1 in the hash table so it gets a new quantity number. */ |
3936 | if (op1_elt == 0) | |
3937 | { | |
9714cf43 | 3938 | if (insert_regs (op1, NULL, 0)) |
7afe21cc RK |
3939 | { |
3940 | rehash_using_reg (op1); | |
2197a88a | 3941 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
3942 | } |
3943 | ||
9714cf43 | 3944 | op1_elt = insert (op1, NULL, op1_hash, mode); |
7afe21cc | 3945 | op1_elt->in_memory = op1_in_memory; |
7afe21cc RK |
3946 | } |
3947 | ||
1bb98cec DM |
3948 | ent->comparison_const = NULL_RTX; |
3949 | ent->comparison_qty = REG_QTY (REGNO (op1)); | |
7afe21cc RK |
3950 | } |
3951 | else | |
3952 | { | |
1bb98cec DM |
3953 | ent->comparison_const = op1; |
3954 | ent->comparison_qty = -1; | |
7afe21cc RK |
3955 | } |
3956 | ||
3957 | return; | |
3958 | } | |
3959 | ||
eb5ad42a RS |
3960 | /* If either side is still missing an equivalence, make it now, |
3961 | then merge the equivalences. */ | |
7afe21cc | 3962 | |
7afe21cc RK |
3963 | if (op0_elt == 0) |
3964 | { | |
9714cf43 | 3965 | if (insert_regs (op0, NULL, 0)) |
7afe21cc RK |
3966 | { |
3967 | rehash_using_reg (op0); | |
2197a88a | 3968 | op0_hash = HASH (op0, mode); |
7afe21cc RK |
3969 | } |
3970 | ||
9714cf43 | 3971 | op0_elt = insert (op0, NULL, op0_hash, mode); |
7afe21cc | 3972 | op0_elt->in_memory = op0_in_memory; |
7afe21cc RK |
3973 | } |
3974 | ||
3975 | if (op1_elt == 0) | |
3976 | { | |
9714cf43 | 3977 | if (insert_regs (op1, NULL, 0)) |
7afe21cc RK |
3978 | { |
3979 | rehash_using_reg (op1); | |
2197a88a | 3980 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
3981 | } |
3982 | ||
9714cf43 | 3983 | op1_elt = insert (op1, NULL, op1_hash, mode); |
7afe21cc | 3984 | op1_elt->in_memory = op1_in_memory; |
7afe21cc | 3985 | } |
eb5ad42a RS |
3986 | |
3987 | merge_equiv_classes (op0_elt, op1_elt); | |
7afe21cc RK |
3988 | } |
3989 | \f | |
3990 | /* CSE processing for one instruction. | |
3991 | First simplify sources and addresses of all assignments | |
3992 | in the instruction, using previously-computed equivalents values. | |
3993 | Then install the new sources and destinations in the table | |
278a83b2 | 3994 | of available values. |
7afe21cc | 3995 | |
1ed0205e VM |
3996 | If LIBCALL_INSN is nonzero, don't record any equivalence made in |
3997 | the insn. It means that INSN is inside libcall block. In this | |
ddc356e8 | 3998 | case LIBCALL_INSN is the corresponding insn with REG_LIBCALL. */ |
7afe21cc RK |
3999 | |
4000 | /* Data on one SET contained in the instruction. */ | |
4001 | ||
4002 | struct set | |
4003 | { | |
4004 | /* The SET rtx itself. */ | |
4005 | rtx rtl; | |
4006 | /* The SET_SRC of the rtx (the original value, if it is changing). */ | |
4007 | rtx src; | |
4008 | /* The hash-table element for the SET_SRC of the SET. */ | |
4009 | struct table_elt *src_elt; | |
2197a88a RK |
4010 | /* Hash value for the SET_SRC. */ |
4011 | unsigned src_hash; | |
4012 | /* Hash value for the SET_DEST. */ | |
4013 | unsigned dest_hash; | |
7afe21cc RK |
4014 | /* The SET_DEST, with SUBREG, etc., stripped. */ |
4015 | rtx inner_dest; | |
278a83b2 | 4016 | /* Nonzero if the SET_SRC is in memory. */ |
7afe21cc | 4017 | char src_in_memory; |
7afe21cc RK |
4018 | /* Nonzero if the SET_SRC contains something |
4019 | whose value cannot be predicted and understood. */ | |
4020 | char src_volatile; | |
496324d0 DN |
4021 | /* Original machine mode, in case it becomes a CONST_INT. |
4022 | The size of this field should match the size of the mode | |
4023 | field of struct rtx_def (see rtl.h). */ | |
4024 | ENUM_BITFIELD(machine_mode) mode : 8; | |
7afe21cc RK |
4025 | /* A constant equivalent for SET_SRC, if any. */ |
4026 | rtx src_const; | |
47841d1b JJ |
4027 | /* Original SET_SRC value used for libcall notes. */ |
4028 | rtx orig_src; | |
2197a88a RK |
4029 | /* Hash value of constant equivalent for SET_SRC. */ |
4030 | unsigned src_const_hash; | |
7afe21cc RK |
4031 | /* Table entry for constant equivalent for SET_SRC, if any. */ |
4032 | struct table_elt *src_const_elt; | |
05c433f3 PB |
4033 | /* Table entry for the destination address. */ |
4034 | struct table_elt *dest_addr_elt; | |
7afe21cc RK |
4035 | }; |
4036 | ||
4037 | static void | |
7080f735 | 4038 | cse_insn (rtx insn, rtx libcall_insn) |
7afe21cc | 4039 | { |
b3694847 SS |
4040 | rtx x = PATTERN (insn); |
4041 | int i; | |
92f9aa51 | 4042 | rtx tem; |
b3694847 | 4043 | int n_sets = 0; |
7afe21cc | 4044 | |
7afe21cc RK |
4045 | rtx src_eqv = 0; |
4046 | struct table_elt *src_eqv_elt = 0; | |
6a651371 KG |
4047 | int src_eqv_volatile = 0; |
4048 | int src_eqv_in_memory = 0; | |
6a651371 | 4049 | unsigned src_eqv_hash = 0; |
7afe21cc | 4050 | |
9714cf43 | 4051 | struct set *sets = (struct set *) 0; |
7afe21cc RK |
4052 | |
4053 | this_insn = insn; | |
192232e2 RS |
4054 | #ifdef HAVE_cc0 |
4055 | /* Records what this insn does to set CC0. */ | |
4056 | this_insn_cc0 = 0; | |
4057 | this_insn_cc0_mode = VOIDmode; | |
4058 | #endif | |
7afe21cc RK |
4059 | |
4060 | /* Find all the SETs and CLOBBERs in this instruction. | |
4061 | Record all the SETs in the array `set' and count them. | |
4062 | Also determine whether there is a CLOBBER that invalidates | |
4063 | all memory references, or all references at varying addresses. */ | |
4064 | ||
4b4bf941 | 4065 | if (CALL_P (insn)) |
f1e7c95f RK |
4066 | { |
4067 | for (tem = CALL_INSN_FUNCTION_USAGE (insn); tem; tem = XEXP (tem, 1)) | |
f474c6f8 AO |
4068 | { |
4069 | if (GET_CODE (XEXP (tem, 0)) == CLOBBER) | |
4070 | invalidate (SET_DEST (XEXP (tem, 0)), VOIDmode); | |
4071 | XEXP (tem, 0) = canon_reg (XEXP (tem, 0), insn); | |
4072 | } | |
f1e7c95f RK |
4073 | } |
4074 | ||
7afe21cc RK |
4075 | if (GET_CODE (x) == SET) |
4076 | { | |
703ad42b | 4077 | sets = alloca (sizeof (struct set)); |
7afe21cc RK |
4078 | sets[0].rtl = x; |
4079 | ||
4080 | /* Ignore SETs that are unconditional jumps. | |
4081 | They never need cse processing, so this does not hurt. | |
4082 | The reason is not efficiency but rather | |
4083 | so that we can test at the end for instructions | |
4084 | that have been simplified to unconditional jumps | |
4085 | and not be misled by unchanged instructions | |
4086 | that were unconditional jumps to begin with. */ | |
4087 | if (SET_DEST (x) == pc_rtx | |
4088 | && GET_CODE (SET_SRC (x)) == LABEL_REF) | |
4089 | ; | |
4090 | ||
4091 | /* Don't count call-insns, (set (reg 0) (call ...)), as a set. | |
4092 | The hard function value register is used only once, to copy to | |
4093 | someplace else, so it isn't worth cse'ing (and on 80386 is unsafe)! | |
4094 | Ensure we invalidate the destination register. On the 80386 no | |
7722328e | 4095 | other code would invalidate it since it is a fixed_reg. |
0f41302f | 4096 | We need not check the return of apply_change_group; see canon_reg. */ |
7afe21cc RK |
4097 | |
4098 | else if (GET_CODE (SET_SRC (x)) == CALL) | |
4099 | { | |
4100 | canon_reg (SET_SRC (x), insn); | |
77fa0940 | 4101 | apply_change_group (); |
7afe21cc | 4102 | fold_rtx (SET_SRC (x), insn); |
bb4034b3 | 4103 | invalidate (SET_DEST (x), VOIDmode); |
7afe21cc RK |
4104 | } |
4105 | else | |
4106 | n_sets = 1; | |
4107 | } | |
4108 | else if (GET_CODE (x) == PARALLEL) | |
4109 | { | |
b3694847 | 4110 | int lim = XVECLEN (x, 0); |
7afe21cc | 4111 | |
703ad42b | 4112 | sets = alloca (lim * sizeof (struct set)); |
7afe21cc RK |
4113 | |
4114 | /* Find all regs explicitly clobbered in this insn, | |
4115 | and ensure they are not replaced with any other regs | |
4116 | elsewhere in this insn. | |
4117 | When a reg that is clobbered is also used for input, | |
4118 | we should presume that that is for a reason, | |
4119 | and we should not substitute some other register | |
4120 | which is not supposed to be clobbered. | |
4121 | Therefore, this loop cannot be merged into the one below | |
830a38ee | 4122 | because a CALL may precede a CLOBBER and refer to the |
7afe21cc RK |
4123 | value clobbered. We must not let a canonicalization do |
4124 | anything in that case. */ | |
4125 | for (i = 0; i < lim; i++) | |
4126 | { | |
b3694847 | 4127 | rtx y = XVECEXP (x, 0, i); |
2708da92 RS |
4128 | if (GET_CODE (y) == CLOBBER) |
4129 | { | |
4130 | rtx clobbered = XEXP (y, 0); | |
4131 | ||
f8cfc6aa | 4132 | if (REG_P (clobbered) |
2708da92 | 4133 | || GET_CODE (clobbered) == SUBREG) |
bb4034b3 | 4134 | invalidate (clobbered, VOIDmode); |
2708da92 RS |
4135 | else if (GET_CODE (clobbered) == STRICT_LOW_PART |
4136 | || GET_CODE (clobbered) == ZERO_EXTRACT) | |
bb4034b3 | 4137 | invalidate (XEXP (clobbered, 0), GET_MODE (clobbered)); |
2708da92 | 4138 | } |
7afe21cc | 4139 | } |
278a83b2 | 4140 | |
7afe21cc RK |
4141 | for (i = 0; i < lim; i++) |
4142 | { | |
b3694847 | 4143 | rtx y = XVECEXP (x, 0, i); |
7afe21cc RK |
4144 | if (GET_CODE (y) == SET) |
4145 | { | |
7722328e RK |
4146 | /* As above, we ignore unconditional jumps and call-insns and |
4147 | ignore the result of apply_change_group. */ | |
7afe21cc RK |
4148 | if (GET_CODE (SET_SRC (y)) == CALL) |
4149 | { | |
4150 | canon_reg (SET_SRC (y), insn); | |
77fa0940 | 4151 | apply_change_group (); |
7afe21cc | 4152 | fold_rtx (SET_SRC (y), insn); |
bb4034b3 | 4153 | invalidate (SET_DEST (y), VOIDmode); |
7afe21cc RK |
4154 | } |
4155 | else if (SET_DEST (y) == pc_rtx | |
4156 | && GET_CODE (SET_SRC (y)) == LABEL_REF) | |
4157 | ; | |
4158 | else | |
4159 | sets[n_sets++].rtl = y; | |
4160 | } | |
4161 | else if (GET_CODE (y) == CLOBBER) | |
4162 | { | |
9ae8ffe7 | 4163 | /* If we clobber memory, canon the address. |
7afe21cc RK |
4164 | This does nothing when a register is clobbered |
4165 | because we have already invalidated the reg. */ | |
3c0cb5de | 4166 | if (MEM_P (XEXP (y, 0))) |
9ae8ffe7 | 4167 | canon_reg (XEXP (y, 0), NULL_RTX); |
7afe21cc RK |
4168 | } |
4169 | else if (GET_CODE (y) == USE | |
f8cfc6aa | 4170 | && ! (REG_P (XEXP (y, 0)) |
7afe21cc | 4171 | && REGNO (XEXP (y, 0)) < FIRST_PSEUDO_REGISTER)) |
906c4e36 | 4172 | canon_reg (y, NULL_RTX); |
7afe21cc RK |
4173 | else if (GET_CODE (y) == CALL) |
4174 | { | |
7722328e RK |
4175 | /* The result of apply_change_group can be ignored; see |
4176 | canon_reg. */ | |
7afe21cc | 4177 | canon_reg (y, insn); |
77fa0940 | 4178 | apply_change_group (); |
7afe21cc RK |
4179 | fold_rtx (y, insn); |
4180 | } | |
4181 | } | |
4182 | } | |
4183 | else if (GET_CODE (x) == CLOBBER) | |
4184 | { | |
3c0cb5de | 4185 | if (MEM_P (XEXP (x, 0))) |
9ae8ffe7 | 4186 | canon_reg (XEXP (x, 0), NULL_RTX); |
7afe21cc RK |
4187 | } |
4188 | ||
4189 | /* Canonicalize a USE of a pseudo register or memory location. */ | |
4190 | else if (GET_CODE (x) == USE | |
f8cfc6aa | 4191 | && ! (REG_P (XEXP (x, 0)) |
7afe21cc | 4192 | && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)) |
906c4e36 | 4193 | canon_reg (XEXP (x, 0), NULL_RTX); |
7afe21cc RK |
4194 | else if (GET_CODE (x) == CALL) |
4195 | { | |
7722328e | 4196 | /* The result of apply_change_group can be ignored; see canon_reg. */ |
7afe21cc | 4197 | canon_reg (x, insn); |
77fa0940 | 4198 | apply_change_group (); |
7afe21cc RK |
4199 | fold_rtx (x, insn); |
4200 | } | |
4201 | ||
7b3ab05e JW |
4202 | /* Store the equivalent value in SRC_EQV, if different, or if the DEST |
4203 | is a STRICT_LOW_PART. The latter condition is necessary because SRC_EQV | |
4204 | is handled specially for this case, and if it isn't set, then there will | |
9faa82d8 | 4205 | be no equivalence for the destination. */ |
92f9aa51 RK |
4206 | if (n_sets == 1 && REG_NOTES (insn) != 0 |
4207 | && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0 | |
7b3ab05e JW |
4208 | && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl)) |
4209 | || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART)) | |
7b668f9e JJ |
4210 | { |
4211 | src_eqv = fold_rtx (canon_reg (XEXP (tem, 0), NULL_RTX), insn); | |
4212 | XEXP (tem, 0) = src_eqv; | |
4213 | } | |
7afe21cc RK |
4214 | |
4215 | /* Canonicalize sources and addresses of destinations. | |
4216 | We do this in a separate pass to avoid problems when a MATCH_DUP is | |
4217 | present in the insn pattern. In that case, we want to ensure that | |
4218 | we don't break the duplicate nature of the pattern. So we will replace | |
4219 | both operands at the same time. Otherwise, we would fail to find an | |
4220 | equivalent substitution in the loop calling validate_change below. | |
7afe21cc RK |
4221 | |
4222 | We used to suppress canonicalization of DEST if it appears in SRC, | |
77fa0940 | 4223 | but we don't do this any more. */ |
7afe21cc RK |
4224 | |
4225 | for (i = 0; i < n_sets; i++) | |
4226 | { | |
4227 | rtx dest = SET_DEST (sets[i].rtl); | |
4228 | rtx src = SET_SRC (sets[i].rtl); | |
4229 | rtx new = canon_reg (src, insn); | |
4230 | ||
47841d1b | 4231 | sets[i].orig_src = src; |
67e0a632 | 4232 | validate_change (insn, &SET_SRC (sets[i].rtl), new, 1); |
7afe21cc | 4233 | |
46d096a3 | 4234 | if (GET_CODE (dest) == ZERO_EXTRACT) |
7afe21cc RK |
4235 | { |
4236 | validate_change (insn, &XEXP (dest, 1), | |
77fa0940 | 4237 | canon_reg (XEXP (dest, 1), insn), 1); |
7afe21cc | 4238 | validate_change (insn, &XEXP (dest, 2), |
77fa0940 | 4239 | canon_reg (XEXP (dest, 2), insn), 1); |
7afe21cc RK |
4240 | } |
4241 | ||
46d096a3 | 4242 | while (GET_CODE (dest) == SUBREG |
7afe21cc | 4243 | || GET_CODE (dest) == ZERO_EXTRACT |
46d096a3 | 4244 | || GET_CODE (dest) == STRICT_LOW_PART) |
7afe21cc RK |
4245 | dest = XEXP (dest, 0); |
4246 | ||
3c0cb5de | 4247 | if (MEM_P (dest)) |
7afe21cc RK |
4248 | canon_reg (dest, insn); |
4249 | } | |
4250 | ||
77fa0940 RK |
4251 | /* Now that we have done all the replacements, we can apply the change |
4252 | group and see if they all work. Note that this will cause some | |
4253 | canonicalizations that would have worked individually not to be applied | |
4254 | because some other canonicalization didn't work, but this should not | |
278a83b2 | 4255 | occur often. |
7722328e RK |
4256 | |
4257 | The result of apply_change_group can be ignored; see canon_reg. */ | |
77fa0940 RK |
4258 | |
4259 | apply_change_group (); | |
4260 | ||
7afe21cc RK |
4261 | /* Set sets[i].src_elt to the class each source belongs to. |
4262 | Detect assignments from or to volatile things | |
4263 | and set set[i] to zero so they will be ignored | |
4264 | in the rest of this function. | |
4265 | ||
4266 | Nothing in this loop changes the hash table or the register chains. */ | |
4267 | ||
4268 | for (i = 0; i < n_sets; i++) | |
4269 | { | |
b3694847 SS |
4270 | rtx src, dest; |
4271 | rtx src_folded; | |
4272 | struct table_elt *elt = 0, *p; | |
7afe21cc RK |
4273 | enum machine_mode mode; |
4274 | rtx src_eqv_here; | |
4275 | rtx src_const = 0; | |
4276 | rtx src_related = 0; | |
4277 | struct table_elt *src_const_elt = 0; | |
99a9c946 GS |
4278 | int src_cost = MAX_COST; |
4279 | int src_eqv_cost = MAX_COST; | |
4280 | int src_folded_cost = MAX_COST; | |
4281 | int src_related_cost = MAX_COST; | |
4282 | int src_elt_cost = MAX_COST; | |
4283 | int src_regcost = MAX_COST; | |
4284 | int src_eqv_regcost = MAX_COST; | |
4285 | int src_folded_regcost = MAX_COST; | |
4286 | int src_related_regcost = MAX_COST; | |
4287 | int src_elt_regcost = MAX_COST; | |
da7d8304 | 4288 | /* Set nonzero if we need to call force_const_mem on with the |
7afe21cc RK |
4289 | contents of src_folded before using it. */ |
4290 | int src_folded_force_flag = 0; | |
4291 | ||
4292 | dest = SET_DEST (sets[i].rtl); | |
4293 | src = SET_SRC (sets[i].rtl); | |
4294 | ||
4295 | /* If SRC is a constant that has no machine mode, | |
4296 | hash it with the destination's machine mode. | |
4297 | This way we can keep different modes separate. */ | |
4298 | ||
4299 | mode = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src); | |
4300 | sets[i].mode = mode; | |
4301 | ||
4302 | if (src_eqv) | |
4303 | { | |
4304 | enum machine_mode eqvmode = mode; | |
4305 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
4306 | eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0))); | |
4307 | do_not_record = 0; | |
4308 | hash_arg_in_memory = 0; | |
2197a88a | 4309 | src_eqv_hash = HASH (src_eqv, eqvmode); |
7afe21cc RK |
4310 | |
4311 | /* Find the equivalence class for the equivalent expression. */ | |
4312 | ||
4313 | if (!do_not_record) | |
2197a88a | 4314 | src_eqv_elt = lookup (src_eqv, src_eqv_hash, eqvmode); |
7afe21cc RK |
4315 | |
4316 | src_eqv_volatile = do_not_record; | |
4317 | src_eqv_in_memory = hash_arg_in_memory; | |
7afe21cc RK |
4318 | } |
4319 | ||
4320 | /* If this is a STRICT_LOW_PART assignment, src_eqv corresponds to the | |
4321 | value of the INNER register, not the destination. So it is not | |
3826a3da | 4322 | a valid substitution for the source. But save it for later. */ |
7afe21cc RK |
4323 | if (GET_CODE (dest) == STRICT_LOW_PART) |
4324 | src_eqv_here = 0; | |
4325 | else | |
4326 | src_eqv_here = src_eqv; | |
4327 | ||
4328 | /* Simplify and foldable subexpressions in SRC. Then get the fully- | |
4329 | simplified result, which may not necessarily be valid. */ | |
4330 | src_folded = fold_rtx (src, insn); | |
4331 | ||
e6a125a0 RK |
4332 | #if 0 |
4333 | /* ??? This caused bad code to be generated for the m68k port with -O2. | |
4334 | Suppose src is (CONST_INT -1), and that after truncation src_folded | |
4335 | is (CONST_INT 3). Suppose src_folded is then used for src_const. | |
4336 | At the end we will add src and src_const to the same equivalence | |
4337 | class. We now have 3 and -1 on the same equivalence class. This | |
4338 | causes later instructions to be mis-optimized. */ | |
7afe21cc RK |
4339 | /* If storing a constant in a bitfield, pre-truncate the constant |
4340 | so we will be able to record it later. */ | |
46d096a3 | 4341 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT) |
7afe21cc RK |
4342 | { |
4343 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
4344 | ||
4345 | if (GET_CODE (src) == CONST_INT | |
4346 | && GET_CODE (width) == CONST_INT | |
906c4e36 RK |
4347 | && INTVAL (width) < HOST_BITS_PER_WIDE_INT |
4348 | && (INTVAL (src) & ((HOST_WIDE_INT) (-1) << INTVAL (width)))) | |
4349 | src_folded | |
4350 | = GEN_INT (INTVAL (src) & (((HOST_WIDE_INT) 1 | |
4351 | << INTVAL (width)) - 1)); | |
7afe21cc | 4352 | } |
e6a125a0 | 4353 | #endif |
7afe21cc RK |
4354 | |
4355 | /* Compute SRC's hash code, and also notice if it | |
4356 | should not be recorded at all. In that case, | |
4357 | prevent any further processing of this assignment. */ | |
4358 | do_not_record = 0; | |
4359 | hash_arg_in_memory = 0; | |
7afe21cc RK |
4360 | |
4361 | sets[i].src = src; | |
2197a88a | 4362 | sets[i].src_hash = HASH (src, mode); |
7afe21cc RK |
4363 | sets[i].src_volatile = do_not_record; |
4364 | sets[i].src_in_memory = hash_arg_in_memory; | |
7afe21cc | 4365 | |
50196afa | 4366 | /* If SRC is a MEM, there is a REG_EQUIV note for SRC, and DEST is |
43e72072 JJ |
4367 | a pseudo, do not record SRC. Using SRC as a replacement for |
4368 | anything else will be incorrect in that situation. Note that | |
4369 | this usually occurs only for stack slots, in which case all the | |
4370 | RTL would be referring to SRC, so we don't lose any optimization | |
4371 | opportunities by not having SRC in the hash table. */ | |
50196afa | 4372 | |
3c0cb5de | 4373 | if (MEM_P (src) |
43e72072 | 4374 | && find_reg_note (insn, REG_EQUIV, NULL_RTX) != 0 |
f8cfc6aa | 4375 | && REG_P (dest) |
43e72072 | 4376 | && REGNO (dest) >= FIRST_PSEUDO_REGISTER) |
50196afa RK |
4377 | sets[i].src_volatile = 1; |
4378 | ||
0dadecf6 RK |
4379 | #if 0 |
4380 | /* It is no longer clear why we used to do this, but it doesn't | |
4381 | appear to still be needed. So let's try without it since this | |
4382 | code hurts cse'ing widened ops. */ | |
9a5a17f3 | 4383 | /* If source is a paradoxical subreg (such as QI treated as an SI), |
7afe21cc RK |
4384 | treat it as volatile. It may do the work of an SI in one context |
4385 | where the extra bits are not being used, but cannot replace an SI | |
4386 | in general. */ | |
4387 | if (GET_CODE (src) == SUBREG | |
4388 | && (GET_MODE_SIZE (GET_MODE (src)) | |
4389 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))))) | |
4390 | sets[i].src_volatile = 1; | |
0dadecf6 | 4391 | #endif |
7afe21cc RK |
4392 | |
4393 | /* Locate all possible equivalent forms for SRC. Try to replace | |
4394 | SRC in the insn with each cheaper equivalent. | |
4395 | ||
4396 | We have the following types of equivalents: SRC itself, a folded | |
4397 | version, a value given in a REG_EQUAL note, or a value related | |
4398 | to a constant. | |
4399 | ||
4400 | Each of these equivalents may be part of an additional class | |
4401 | of equivalents (if more than one is in the table, they must be in | |
4402 | the same class; we check for this). | |
4403 | ||
4404 | If the source is volatile, we don't do any table lookups. | |
4405 | ||
4406 | We note any constant equivalent for possible later use in a | |
4407 | REG_NOTE. */ | |
4408 | ||
4409 | if (!sets[i].src_volatile) | |
2197a88a | 4410 | elt = lookup (src, sets[i].src_hash, mode); |
7afe21cc RK |
4411 | |
4412 | sets[i].src_elt = elt; | |
4413 | ||
4414 | if (elt && src_eqv_here && src_eqv_elt) | |
278a83b2 KH |
4415 | { |
4416 | if (elt->first_same_value != src_eqv_elt->first_same_value) | |
7afe21cc RK |
4417 | { |
4418 | /* The REG_EQUAL is indicating that two formerly distinct | |
4419 | classes are now equivalent. So merge them. */ | |
4420 | merge_equiv_classes (elt, src_eqv_elt); | |
2197a88a RK |
4421 | src_eqv_hash = HASH (src_eqv, elt->mode); |
4422 | src_eqv_elt = lookup (src_eqv, src_eqv_hash, elt->mode); | |
7afe21cc RK |
4423 | } |
4424 | ||
278a83b2 KH |
4425 | src_eqv_here = 0; |
4426 | } | |
7afe21cc RK |
4427 | |
4428 | else if (src_eqv_elt) | |
278a83b2 | 4429 | elt = src_eqv_elt; |
7afe21cc RK |
4430 | |
4431 | /* Try to find a constant somewhere and record it in `src_const'. | |
4432 | Record its table element, if any, in `src_const_elt'. Look in | |
4433 | any known equivalences first. (If the constant is not in the | |
2197a88a | 4434 | table, also set `sets[i].src_const_hash'). */ |
7afe21cc | 4435 | if (elt) |
278a83b2 | 4436 | for (p = elt->first_same_value; p; p = p->next_same_value) |
7afe21cc RK |
4437 | if (p->is_const) |
4438 | { | |
4439 | src_const = p->exp; | |
4440 | src_const_elt = elt; | |
4441 | break; | |
4442 | } | |
4443 | ||
4444 | if (src_const == 0 | |
4445 | && (CONSTANT_P (src_folded) | |
278a83b2 | 4446 | /* Consider (minus (label_ref L1) (label_ref L2)) as |
7afe21cc RK |
4447 | "constant" here so we will record it. This allows us |
4448 | to fold switch statements when an ADDR_DIFF_VEC is used. */ | |
4449 | || (GET_CODE (src_folded) == MINUS | |
4450 | && GET_CODE (XEXP (src_folded, 0)) == LABEL_REF | |
4451 | && GET_CODE (XEXP (src_folded, 1)) == LABEL_REF))) | |
4452 | src_const = src_folded, src_const_elt = elt; | |
4453 | else if (src_const == 0 && src_eqv_here && CONSTANT_P (src_eqv_here)) | |
4454 | src_const = src_eqv_here, src_const_elt = src_eqv_elt; | |
4455 | ||
4456 | /* If we don't know if the constant is in the table, get its | |
4457 | hash code and look it up. */ | |
4458 | if (src_const && src_const_elt == 0) | |
4459 | { | |
2197a88a RK |
4460 | sets[i].src_const_hash = HASH (src_const, mode); |
4461 | src_const_elt = lookup (src_const, sets[i].src_const_hash, mode); | |
7afe21cc RK |
4462 | } |
4463 | ||
4464 | sets[i].src_const = src_const; | |
4465 | sets[i].src_const_elt = src_const_elt; | |
4466 | ||
4467 | /* If the constant and our source are both in the table, mark them as | |
4468 | equivalent. Otherwise, if a constant is in the table but the source | |
4469 | isn't, set ELT to it. */ | |
4470 | if (src_const_elt && elt | |
4471 | && src_const_elt->first_same_value != elt->first_same_value) | |
4472 | merge_equiv_classes (elt, src_const_elt); | |
4473 | else if (src_const_elt && elt == 0) | |
4474 | elt = src_const_elt; | |
4475 | ||
4476 | /* See if there is a register linearly related to a constant | |
4477 | equivalent of SRC. */ | |
4478 | if (src_const | |
4479 | && (GET_CODE (src_const) == CONST | |
4480 | || (src_const_elt && src_const_elt->related_value != 0))) | |
278a83b2 KH |
4481 | { |
4482 | src_related = use_related_value (src_const, src_const_elt); | |
4483 | if (src_related) | |
4484 | { | |
7afe21cc | 4485 | struct table_elt *src_related_elt |
278a83b2 | 4486 | = lookup (src_related, HASH (src_related, mode), mode); |
7afe21cc | 4487 | if (src_related_elt && elt) |
278a83b2 | 4488 | { |
7afe21cc RK |
4489 | if (elt->first_same_value |
4490 | != src_related_elt->first_same_value) | |
278a83b2 | 4491 | /* This can occur when we previously saw a CONST |
7afe21cc RK |
4492 | involving a SYMBOL_REF and then see the SYMBOL_REF |
4493 | twice. Merge the involved classes. */ | |
4494 | merge_equiv_classes (elt, src_related_elt); | |
4495 | ||
278a83b2 | 4496 | src_related = 0; |
7afe21cc | 4497 | src_related_elt = 0; |
278a83b2 KH |
4498 | } |
4499 | else if (src_related_elt && elt == 0) | |
4500 | elt = src_related_elt; | |
7afe21cc | 4501 | } |
278a83b2 | 4502 | } |
7afe21cc | 4503 | |
e4600702 RK |
4504 | /* See if we have a CONST_INT that is already in a register in a |
4505 | wider mode. */ | |
4506 | ||
4507 | if (src_const && src_related == 0 && GET_CODE (src_const) == CONST_INT | |
4508 | && GET_MODE_CLASS (mode) == MODE_INT | |
4509 | && GET_MODE_BITSIZE (mode) < BITS_PER_WORD) | |
4510 | { | |
4511 | enum machine_mode wider_mode; | |
4512 | ||
4513 | for (wider_mode = GET_MODE_WIDER_MODE (mode); | |
4514 | GET_MODE_BITSIZE (wider_mode) <= BITS_PER_WORD | |
4515 | && src_related == 0; | |
4516 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
4517 | { | |
4518 | struct table_elt *const_elt | |
4519 | = lookup (src_const, HASH (src_const, wider_mode), wider_mode); | |
4520 | ||
4521 | if (const_elt == 0) | |
4522 | continue; | |
4523 | ||
4524 | for (const_elt = const_elt->first_same_value; | |
4525 | const_elt; const_elt = const_elt->next_same_value) | |
f8cfc6aa | 4526 | if (REG_P (const_elt->exp)) |
e4600702 | 4527 | { |
73ca11ed | 4528 | src_related = gen_lowpart (mode, const_elt->exp); |
e4600702 RK |
4529 | break; |
4530 | } | |
4531 | } | |
4532 | } | |
4533 | ||
d45cf215 RS |
4534 | /* Another possibility is that we have an AND with a constant in |
4535 | a mode narrower than a word. If so, it might have been generated | |
4536 | as part of an "if" which would narrow the AND. If we already | |
4537 | have done the AND in a wider mode, we can use a SUBREG of that | |
4538 | value. */ | |
4539 | ||
4540 | if (flag_expensive_optimizations && ! src_related | |
4541 | && GET_CODE (src) == AND && GET_CODE (XEXP (src, 1)) == CONST_INT | |
4542 | && GET_MODE_SIZE (mode) < UNITS_PER_WORD) | |
4543 | { | |
4544 | enum machine_mode tmode; | |
38a448ca | 4545 | rtx new_and = gen_rtx_AND (VOIDmode, NULL_RTX, XEXP (src, 1)); |
d45cf215 RS |
4546 | |
4547 | for (tmode = GET_MODE_WIDER_MODE (mode); | |
4548 | GET_MODE_SIZE (tmode) <= UNITS_PER_WORD; | |
4549 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
4550 | { | |
4de249d9 | 4551 | rtx inner = gen_lowpart (tmode, XEXP (src, 0)); |
d45cf215 RS |
4552 | struct table_elt *larger_elt; |
4553 | ||
4554 | if (inner) | |
4555 | { | |
4556 | PUT_MODE (new_and, tmode); | |
4557 | XEXP (new_and, 0) = inner; | |
4558 | larger_elt = lookup (new_and, HASH (new_and, tmode), tmode); | |
4559 | if (larger_elt == 0) | |
4560 | continue; | |
4561 | ||
4562 | for (larger_elt = larger_elt->first_same_value; | |
4563 | larger_elt; larger_elt = larger_elt->next_same_value) | |
f8cfc6aa | 4564 | if (REG_P (larger_elt->exp)) |
d45cf215 RS |
4565 | { |
4566 | src_related | |
4de249d9 | 4567 | = gen_lowpart (mode, larger_elt->exp); |
d45cf215 RS |
4568 | break; |
4569 | } | |
4570 | ||
4571 | if (src_related) | |
4572 | break; | |
4573 | } | |
4574 | } | |
4575 | } | |
7bac1be0 RK |
4576 | |
4577 | #ifdef LOAD_EXTEND_OP | |
4578 | /* See if a MEM has already been loaded with a widening operation; | |
4579 | if it has, we can use a subreg of that. Many CISC machines | |
4580 | also have such operations, but this is only likely to be | |
71cc389b | 4581 | beneficial on these machines. */ |
278a83b2 | 4582 | |
ddc356e8 | 4583 | if (flag_expensive_optimizations && src_related == 0 |
7bac1be0 RK |
4584 | && (GET_MODE_SIZE (mode) < UNITS_PER_WORD) |
4585 | && GET_MODE_CLASS (mode) == MODE_INT | |
3c0cb5de | 4586 | && MEM_P (src) && ! do_not_record |
f822d252 | 4587 | && LOAD_EXTEND_OP (mode) != UNKNOWN) |
7bac1be0 | 4588 | { |
9d80ef7c RH |
4589 | struct rtx_def memory_extend_buf; |
4590 | rtx memory_extend_rtx = &memory_extend_buf; | |
7bac1be0 | 4591 | enum machine_mode tmode; |
278a83b2 | 4592 | |
7bac1be0 RK |
4593 | /* Set what we are trying to extend and the operation it might |
4594 | have been extended with. */ | |
9d80ef7c | 4595 | memset (memory_extend_rtx, 0, sizeof(*memory_extend_rtx)); |
7bac1be0 RK |
4596 | PUT_CODE (memory_extend_rtx, LOAD_EXTEND_OP (mode)); |
4597 | XEXP (memory_extend_rtx, 0) = src; | |
278a83b2 | 4598 | |
7bac1be0 RK |
4599 | for (tmode = GET_MODE_WIDER_MODE (mode); |
4600 | GET_MODE_SIZE (tmode) <= UNITS_PER_WORD; | |
4601 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
4602 | { | |
4603 | struct table_elt *larger_elt; | |
278a83b2 | 4604 | |
7bac1be0 | 4605 | PUT_MODE (memory_extend_rtx, tmode); |
278a83b2 | 4606 | larger_elt = lookup (memory_extend_rtx, |
7bac1be0 RK |
4607 | HASH (memory_extend_rtx, tmode), tmode); |
4608 | if (larger_elt == 0) | |
4609 | continue; | |
278a83b2 | 4610 | |
7bac1be0 RK |
4611 | for (larger_elt = larger_elt->first_same_value; |
4612 | larger_elt; larger_elt = larger_elt->next_same_value) | |
f8cfc6aa | 4613 | if (REG_P (larger_elt->exp)) |
7bac1be0 | 4614 | { |
73ca11ed | 4615 | src_related = gen_lowpart (mode, larger_elt->exp); |
7bac1be0 RK |
4616 | break; |
4617 | } | |
278a83b2 | 4618 | |
7bac1be0 RK |
4619 | if (src_related) |
4620 | break; | |
4621 | } | |
4622 | } | |
4623 | #endif /* LOAD_EXTEND_OP */ | |
278a83b2 | 4624 | |
7afe21cc | 4625 | if (src == src_folded) |
278a83b2 | 4626 | src_folded = 0; |
7afe21cc | 4627 | |
da7d8304 | 4628 | /* At this point, ELT, if nonzero, points to a class of expressions |
7afe21cc | 4629 | equivalent to the source of this SET and SRC, SRC_EQV, SRC_FOLDED, |
da7d8304 | 4630 | and SRC_RELATED, if nonzero, each contain additional equivalent |
7afe21cc RK |
4631 | expressions. Prune these latter expressions by deleting expressions |
4632 | already in the equivalence class. | |
4633 | ||
4634 | Check for an equivalent identical to the destination. If found, | |
4635 | this is the preferred equivalent since it will likely lead to | |
4636 | elimination of the insn. Indicate this by placing it in | |
4637 | `src_related'. */ | |
4638 | ||
278a83b2 KH |
4639 | if (elt) |
4640 | elt = elt->first_same_value; | |
7afe21cc | 4641 | for (p = elt; p; p = p->next_same_value) |
278a83b2 | 4642 | { |
7afe21cc RK |
4643 | enum rtx_code code = GET_CODE (p->exp); |
4644 | ||
4645 | /* If the expression is not valid, ignore it. Then we do not | |
4646 | have to check for validity below. In most cases, we can use | |
4647 | `rtx_equal_p', since canonicalization has already been done. */ | |
0516f6fe | 4648 | if (code != REG && ! exp_equiv_p (p->exp, p->exp, 1, false)) |
7afe21cc RK |
4649 | continue; |
4650 | ||
5a03c8c4 RK |
4651 | /* Also skip paradoxical subregs, unless that's what we're |
4652 | looking for. */ | |
4653 | if (code == SUBREG | |
4654 | && (GET_MODE_SIZE (GET_MODE (p->exp)) | |
4655 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp)))) | |
4656 | && ! (src != 0 | |
4657 | && GET_CODE (src) == SUBREG | |
4658 | && GET_MODE (src) == GET_MODE (p->exp) | |
4659 | && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))) | |
4660 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp)))))) | |
4661 | continue; | |
4662 | ||
278a83b2 | 4663 | if (src && GET_CODE (src) == code && rtx_equal_p (src, p->exp)) |
7afe21cc | 4664 | src = 0; |
278a83b2 | 4665 | else if (src_folded && GET_CODE (src_folded) == code |
7afe21cc RK |
4666 | && rtx_equal_p (src_folded, p->exp)) |
4667 | src_folded = 0; | |
278a83b2 | 4668 | else if (src_eqv_here && GET_CODE (src_eqv_here) == code |
7afe21cc RK |
4669 | && rtx_equal_p (src_eqv_here, p->exp)) |
4670 | src_eqv_here = 0; | |
278a83b2 | 4671 | else if (src_related && GET_CODE (src_related) == code |
7afe21cc RK |
4672 | && rtx_equal_p (src_related, p->exp)) |
4673 | src_related = 0; | |
4674 | ||
4675 | /* This is the same as the destination of the insns, we want | |
4676 | to prefer it. Copy it to src_related. The code below will | |
4677 | then give it a negative cost. */ | |
4678 | if (GET_CODE (dest) == code && rtx_equal_p (p->exp, dest)) | |
4679 | src_related = dest; | |
278a83b2 | 4680 | } |
7afe21cc RK |
4681 | |
4682 | /* Find the cheapest valid equivalent, trying all the available | |
4683 | possibilities. Prefer items not in the hash table to ones | |
4684 | that are when they are equal cost. Note that we can never | |
4685 | worsen an insn as the current contents will also succeed. | |
05c33dd8 | 4686 | If we find an equivalent identical to the destination, use it as best, |
0f41302f | 4687 | since this insn will probably be eliminated in that case. */ |
7afe21cc RK |
4688 | if (src) |
4689 | { | |
4690 | if (rtx_equal_p (src, dest)) | |
f1c1dfc3 | 4691 | src_cost = src_regcost = -1; |
7afe21cc | 4692 | else |
630c79be BS |
4693 | { |
4694 | src_cost = COST (src); | |
4695 | src_regcost = approx_reg_cost (src); | |
4696 | } | |
7afe21cc RK |
4697 | } |
4698 | ||
4699 | if (src_eqv_here) | |
4700 | { | |
4701 | if (rtx_equal_p (src_eqv_here, dest)) | |
f1c1dfc3 | 4702 | src_eqv_cost = src_eqv_regcost = -1; |
7afe21cc | 4703 | else |
630c79be BS |
4704 | { |
4705 | src_eqv_cost = COST (src_eqv_here); | |
4706 | src_eqv_regcost = approx_reg_cost (src_eqv_here); | |
4707 | } | |
7afe21cc RK |
4708 | } |
4709 | ||
4710 | if (src_folded) | |
4711 | { | |
4712 | if (rtx_equal_p (src_folded, dest)) | |
f1c1dfc3 | 4713 | src_folded_cost = src_folded_regcost = -1; |
7afe21cc | 4714 | else |
630c79be BS |
4715 | { |
4716 | src_folded_cost = COST (src_folded); | |
4717 | src_folded_regcost = approx_reg_cost (src_folded); | |
4718 | } | |
7afe21cc RK |
4719 | } |
4720 | ||
4721 | if (src_related) | |
4722 | { | |
4723 | if (rtx_equal_p (src_related, dest)) | |
f1c1dfc3 | 4724 | src_related_cost = src_related_regcost = -1; |
7afe21cc | 4725 | else |
630c79be BS |
4726 | { |
4727 | src_related_cost = COST (src_related); | |
4728 | src_related_regcost = approx_reg_cost (src_related); | |
4729 | } | |
7afe21cc RK |
4730 | } |
4731 | ||
4732 | /* If this was an indirect jump insn, a known label will really be | |
4733 | cheaper even though it looks more expensive. */ | |
4734 | if (dest == pc_rtx && src_const && GET_CODE (src_const) == LABEL_REF) | |
99a9c946 | 4735 | src_folded = src_const, src_folded_cost = src_folded_regcost = -1; |
278a83b2 | 4736 | |
7afe21cc RK |
4737 | /* Terminate loop when replacement made. This must terminate since |
4738 | the current contents will be tested and will always be valid. */ | |
4739 | while (1) | |
278a83b2 KH |
4740 | { |
4741 | rtx trial; | |
7afe21cc | 4742 | |
278a83b2 | 4743 | /* Skip invalid entries. */ |
f8cfc6aa | 4744 | while (elt && !REG_P (elt->exp) |
0516f6fe | 4745 | && ! exp_equiv_p (elt->exp, elt->exp, 1, false)) |
278a83b2 | 4746 | elt = elt->next_same_value; |
5a03c8c4 RK |
4747 | |
4748 | /* A paradoxical subreg would be bad here: it'll be the right | |
4749 | size, but later may be adjusted so that the upper bits aren't | |
4750 | what we want. So reject it. */ | |
4751 | if (elt != 0 | |
4752 | && GET_CODE (elt->exp) == SUBREG | |
4753 | && (GET_MODE_SIZE (GET_MODE (elt->exp)) | |
4754 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp)))) | |
4755 | /* It is okay, though, if the rtx we're trying to match | |
4756 | will ignore any of the bits we can't predict. */ | |
4757 | && ! (src != 0 | |
4758 | && GET_CODE (src) == SUBREG | |
4759 | && GET_MODE (src) == GET_MODE (elt->exp) | |
4760 | && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))) | |
4761 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp)))))) | |
4762 | { | |
4763 | elt = elt->next_same_value; | |
4764 | continue; | |
4765 | } | |
278a83b2 | 4766 | |
68252e27 | 4767 | if (elt) |
630c79be BS |
4768 | { |
4769 | src_elt_cost = elt->cost; | |
4770 | src_elt_regcost = elt->regcost; | |
4771 | } | |
7afe21cc | 4772 | |
68252e27 | 4773 | /* Find cheapest and skip it for the next time. For items |
7afe21cc RK |
4774 | of equal cost, use this order: |
4775 | src_folded, src, src_eqv, src_related and hash table entry. */ | |
99a9c946 | 4776 | if (src_folded |
56ae04af KH |
4777 | && preferable (src_folded_cost, src_folded_regcost, |
4778 | src_cost, src_regcost) <= 0 | |
4779 | && preferable (src_folded_cost, src_folded_regcost, | |
4780 | src_eqv_cost, src_eqv_regcost) <= 0 | |
4781 | && preferable (src_folded_cost, src_folded_regcost, | |
4782 | src_related_cost, src_related_regcost) <= 0 | |
4783 | && preferable (src_folded_cost, src_folded_regcost, | |
4784 | src_elt_cost, src_elt_regcost) <= 0) | |
7afe21cc | 4785 | { |
f1c1dfc3 | 4786 | trial = src_folded, src_folded_cost = MAX_COST; |
7afe21cc | 4787 | if (src_folded_force_flag) |
9d8de1de EB |
4788 | { |
4789 | rtx forced = force_const_mem (mode, trial); | |
4790 | if (forced) | |
4791 | trial = forced; | |
4792 | } | |
7afe21cc | 4793 | } |
99a9c946 | 4794 | else if (src |
56ae04af KH |
4795 | && preferable (src_cost, src_regcost, |
4796 | src_eqv_cost, src_eqv_regcost) <= 0 | |
4797 | && preferable (src_cost, src_regcost, | |
4798 | src_related_cost, src_related_regcost) <= 0 | |
4799 | && preferable (src_cost, src_regcost, | |
4800 | src_elt_cost, src_elt_regcost) <= 0) | |
f1c1dfc3 | 4801 | trial = src, src_cost = MAX_COST; |
99a9c946 | 4802 | else if (src_eqv_here |
56ae04af KH |
4803 | && preferable (src_eqv_cost, src_eqv_regcost, |
4804 | src_related_cost, src_related_regcost) <= 0 | |
4805 | && preferable (src_eqv_cost, src_eqv_regcost, | |
4806 | src_elt_cost, src_elt_regcost) <= 0) | |
f1c1dfc3 | 4807 | trial = copy_rtx (src_eqv_here), src_eqv_cost = MAX_COST; |
99a9c946 | 4808 | else if (src_related |
56ae04af KH |
4809 | && preferable (src_related_cost, src_related_regcost, |
4810 | src_elt_cost, src_elt_regcost) <= 0) | |
68252e27 | 4811 | trial = copy_rtx (src_related), src_related_cost = MAX_COST; |
278a83b2 | 4812 | else |
7afe21cc | 4813 | { |
05c33dd8 | 4814 | trial = copy_rtx (elt->exp); |
7afe21cc | 4815 | elt = elt->next_same_value; |
f1c1dfc3 | 4816 | src_elt_cost = MAX_COST; |
7afe21cc RK |
4817 | } |
4818 | ||
4819 | /* We don't normally have an insn matching (set (pc) (pc)), so | |
4820 | check for this separately here. We will delete such an | |
4821 | insn below. | |
4822 | ||
d466c016 JL |
4823 | For other cases such as a table jump or conditional jump |
4824 | where we know the ultimate target, go ahead and replace the | |
4825 | operand. While that may not make a valid insn, we will | |
4826 | reemit the jump below (and also insert any necessary | |
4827 | barriers). */ | |
7afe21cc RK |
4828 | if (n_sets == 1 && dest == pc_rtx |
4829 | && (trial == pc_rtx | |
4830 | || (GET_CODE (trial) == LABEL_REF | |
4831 | && ! condjump_p (insn)))) | |
4832 | { | |
2f39b6ca UW |
4833 | /* Don't substitute non-local labels, this confuses CFG. */ |
4834 | if (GET_CODE (trial) == LABEL_REF | |
4835 | && LABEL_REF_NONLOCAL_P (trial)) | |
4836 | continue; | |
4837 | ||
d466c016 | 4838 | SET_SRC (sets[i].rtl) = trial; |
602c4c0d | 4839 | cse_jumps_altered = 1; |
7afe21cc RK |
4840 | break; |
4841 | } | |
278a83b2 | 4842 | |
1ef6855c KH |
4843 | /* Reject certain invalid forms of CONST that we create. */ |
4844 | else if (CONSTANT_P (trial) | |
4845 | && GET_CODE (trial) == CONST | |
4846 | /* Reject cases that will cause decode_rtx_const to | |
4847 | die. On the alpha when simplifying a switch, we | |
4848 | get (const (truncate (minus (label_ref) | |
4849 | (label_ref)))). */ | |
4850 | && (GET_CODE (XEXP (trial, 0)) == TRUNCATE | |
4851 | /* Likewise on IA-64, except without the | |
4852 | truncate. */ | |
4853 | || (GET_CODE (XEXP (trial, 0)) == MINUS | |
4854 | && GET_CODE (XEXP (XEXP (trial, 0), 0)) == LABEL_REF | |
4855 | && GET_CODE (XEXP (XEXP (trial, 0), 1)) == LABEL_REF))) | |
4856 | /* Do nothing for this case. */ | |
4857 | ; | |
4858 | ||
7afe21cc | 4859 | /* Look for a substitution that makes a valid insn. */ |
ddc356e8 | 4860 | else if (validate_change (insn, &SET_SRC (sets[i].rtl), trial, 0)) |
05c33dd8 | 4861 | { |
dbaff908 RS |
4862 | rtx new = canon_reg (SET_SRC (sets[i].rtl), insn); |
4863 | ||
7bd8b2a8 JL |
4864 | /* If we just made a substitution inside a libcall, then we |
4865 | need to make the same substitution in any notes attached | |
4866 | to the RETVAL insn. */ | |
1ed0205e | 4867 | if (libcall_insn |
f8cfc6aa | 4868 | && (REG_P (sets[i].orig_src) |
47841d1b | 4869 | || GET_CODE (sets[i].orig_src) == SUBREG |
3c0cb5de | 4870 | || MEM_P (sets[i].orig_src))) |
d8b7ec41 RS |
4871 | { |
4872 | rtx note = find_reg_equal_equiv_note (libcall_insn); | |
4873 | if (note != 0) | |
4874 | XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0), | |
4875 | sets[i].orig_src, | |
4876 | copy_rtx (new)); | |
4877 | } | |
7bd8b2a8 | 4878 | |
7722328e RK |
4879 | /* The result of apply_change_group can be ignored; see |
4880 | canon_reg. */ | |
4881 | ||
dbaff908 | 4882 | validate_change (insn, &SET_SRC (sets[i].rtl), new, 1); |
6702af89 | 4883 | apply_change_group (); |
932ad4d9 | 4884 | |
05c33dd8 RK |
4885 | break; |
4886 | } | |
7afe21cc | 4887 | |
278a83b2 | 4888 | /* If we previously found constant pool entries for |
7afe21cc RK |
4889 | constants and this is a constant, try making a |
4890 | pool entry. Put it in src_folded unless we already have done | |
4891 | this since that is where it likely came from. */ | |
4892 | ||
4893 | else if (constant_pool_entries_cost | |
4894 | && CONSTANT_P (trial) | |
1bbd065b | 4895 | && (src_folded == 0 |
3c0cb5de | 4896 | || (!MEM_P (src_folded) |
1bbd065b | 4897 | && ! src_folded_force_flag)) |
9ae8ffe7 JL |
4898 | && GET_MODE_CLASS (mode) != MODE_CC |
4899 | && mode != VOIDmode) | |
7afe21cc RK |
4900 | { |
4901 | src_folded_force_flag = 1; | |
4902 | src_folded = trial; | |
4903 | src_folded_cost = constant_pool_entries_cost; | |
dd0ba281 | 4904 | src_folded_regcost = constant_pool_entries_regcost; |
7afe21cc | 4905 | } |
278a83b2 | 4906 | } |
7afe21cc RK |
4907 | |
4908 | src = SET_SRC (sets[i].rtl); | |
4909 | ||
4910 | /* In general, it is good to have a SET with SET_SRC == SET_DEST. | |
4911 | However, there is an important exception: If both are registers | |
4912 | that are not the head of their equivalence class, replace SET_SRC | |
4913 | with the head of the class. If we do not do this, we will have | |
4914 | both registers live over a portion of the basic block. This way, | |
4915 | their lifetimes will likely abut instead of overlapping. */ | |
f8cfc6aa | 4916 | if (REG_P (dest) |
1bb98cec | 4917 | && REGNO_QTY_VALID_P (REGNO (dest))) |
7afe21cc | 4918 | { |
1bb98cec DM |
4919 | int dest_q = REG_QTY (REGNO (dest)); |
4920 | struct qty_table_elem *dest_ent = &qty_table[dest_q]; | |
4921 | ||
4922 | if (dest_ent->mode == GET_MODE (dest) | |
4923 | && dest_ent->first_reg != REGNO (dest) | |
f8cfc6aa | 4924 | && REG_P (src) && REGNO (src) == REGNO (dest) |
1bb98cec DM |
4925 | /* Don't do this if the original insn had a hard reg as |
4926 | SET_SRC or SET_DEST. */ | |
f8cfc6aa | 4927 | && (!REG_P (sets[i].src) |
1bb98cec | 4928 | || REGNO (sets[i].src) >= FIRST_PSEUDO_REGISTER) |
f8cfc6aa | 4929 | && (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER)) |
1bb98cec DM |
4930 | /* We can't call canon_reg here because it won't do anything if |
4931 | SRC is a hard register. */ | |
759bd8b7 | 4932 | { |
1bb98cec DM |
4933 | int src_q = REG_QTY (REGNO (src)); |
4934 | struct qty_table_elem *src_ent = &qty_table[src_q]; | |
4935 | int first = src_ent->first_reg; | |
4936 | rtx new_src | |
4937 | = (first >= FIRST_PSEUDO_REGISTER | |
4938 | ? regno_reg_rtx[first] : gen_rtx_REG (GET_MODE (src), first)); | |
4939 | ||
4940 | /* We must use validate-change even for this, because this | |
4941 | might be a special no-op instruction, suitable only to | |
4942 | tag notes onto. */ | |
4943 | if (validate_change (insn, &SET_SRC (sets[i].rtl), new_src, 0)) | |
4944 | { | |
4945 | src = new_src; | |
4946 | /* If we had a constant that is cheaper than what we are now | |
4947 | setting SRC to, use that constant. We ignored it when we | |
4948 | thought we could make this into a no-op. */ | |
4949 | if (src_const && COST (src_const) < COST (src) | |
278a83b2 KH |
4950 | && validate_change (insn, &SET_SRC (sets[i].rtl), |
4951 | src_const, 0)) | |
1bb98cec DM |
4952 | src = src_const; |
4953 | } | |
759bd8b7 | 4954 | } |
7afe21cc RK |
4955 | } |
4956 | ||
4957 | /* If we made a change, recompute SRC values. */ | |
4958 | if (src != sets[i].src) | |
278a83b2 | 4959 | { |
278a83b2 KH |
4960 | do_not_record = 0; |
4961 | hash_arg_in_memory = 0; | |
7afe21cc | 4962 | sets[i].src = src; |
278a83b2 KH |
4963 | sets[i].src_hash = HASH (src, mode); |
4964 | sets[i].src_volatile = do_not_record; | |
4965 | sets[i].src_in_memory = hash_arg_in_memory; | |
4966 | sets[i].src_elt = lookup (src, sets[i].src_hash, mode); | |
4967 | } | |
7afe21cc RK |
4968 | |
4969 | /* If this is a single SET, we are setting a register, and we have an | |
4970 | equivalent constant, we want to add a REG_NOTE. We don't want | |
4971 | to write a REG_EQUAL note for a constant pseudo since verifying that | |
d45cf215 | 4972 | that pseudo hasn't been eliminated is a pain. Such a note also |
278a83b2 | 4973 | won't help anything. |
ac7ef8d5 FS |
4974 | |
4975 | Avoid a REG_EQUAL note for (CONST (MINUS (LABEL_REF) (LABEL_REF))) | |
4976 | which can be created for a reference to a compile time computable | |
4977 | entry in a jump table. */ | |
4978 | ||
f8cfc6aa JQ |
4979 | if (n_sets == 1 && src_const && REG_P (dest) |
4980 | && !REG_P (src_const) | |
ac7ef8d5 FS |
4981 | && ! (GET_CODE (src_const) == CONST |
4982 | && GET_CODE (XEXP (src_const, 0)) == MINUS | |
4983 | && GET_CODE (XEXP (XEXP (src_const, 0), 0)) == LABEL_REF | |
4984 | && GET_CODE (XEXP (XEXP (src_const, 0), 1)) == LABEL_REF)) | |
7afe21cc | 4985 | { |
a77b7e32 RS |
4986 | /* We only want a REG_EQUAL note if src_const != src. */ |
4987 | if (! rtx_equal_p (src, src_const)) | |
4988 | { | |
4989 | /* Make sure that the rtx is not shared. */ | |
4990 | src_const = copy_rtx (src_const); | |
51e2a951 | 4991 | |
a77b7e32 RS |
4992 | /* Record the actual constant value in a REG_EQUAL note, |
4993 | making a new one if one does not already exist. */ | |
4994 | set_unique_reg_note (insn, REG_EQUAL, src_const); | |
4995 | } | |
7afe21cc RK |
4996 | } |
4997 | ||
4998 | /* Now deal with the destination. */ | |
4999 | do_not_record = 0; | |
7afe21cc | 5000 | |
46d096a3 SB |
5001 | /* Look within any ZERO_EXTRACT to the MEM or REG within it. */ |
5002 | while (GET_CODE (dest) == SUBREG | |
7afe21cc | 5003 | || GET_CODE (dest) == ZERO_EXTRACT |
7afe21cc | 5004 | || GET_CODE (dest) == STRICT_LOW_PART) |
0339ce7e | 5005 | dest = XEXP (dest, 0); |
7afe21cc RK |
5006 | |
5007 | sets[i].inner_dest = dest; | |
5008 | ||
3c0cb5de | 5009 | if (MEM_P (dest)) |
7afe21cc | 5010 | { |
9ae8ffe7 JL |
5011 | #ifdef PUSH_ROUNDING |
5012 | /* Stack pushes invalidate the stack pointer. */ | |
5013 | rtx addr = XEXP (dest, 0); | |
ec8e098d | 5014 | if (GET_RTX_CLASS (GET_CODE (addr)) == RTX_AUTOINC |
9ae8ffe7 | 5015 | && XEXP (addr, 0) == stack_pointer_rtx) |
524e3576 | 5016 | invalidate (stack_pointer_rtx, VOIDmode); |
9ae8ffe7 | 5017 | #endif |
7afe21cc | 5018 | dest = fold_rtx (dest, insn); |
7afe21cc RK |
5019 | } |
5020 | ||
5021 | /* Compute the hash code of the destination now, | |
5022 | before the effects of this instruction are recorded, | |
5023 | since the register values used in the address computation | |
5024 | are those before this instruction. */ | |
2197a88a | 5025 | sets[i].dest_hash = HASH (dest, mode); |
7afe21cc RK |
5026 | |
5027 | /* Don't enter a bit-field in the hash table | |
5028 | because the value in it after the store | |
5029 | may not equal what was stored, due to truncation. */ | |
5030 | ||
46d096a3 | 5031 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT) |
7afe21cc RK |
5032 | { |
5033 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
5034 | ||
5035 | if (src_const != 0 && GET_CODE (src_const) == CONST_INT | |
5036 | && GET_CODE (width) == CONST_INT | |
906c4e36 RK |
5037 | && INTVAL (width) < HOST_BITS_PER_WIDE_INT |
5038 | && ! (INTVAL (src_const) | |
5039 | & ((HOST_WIDE_INT) (-1) << INTVAL (width)))) | |
7afe21cc RK |
5040 | /* Exception: if the value is constant, |
5041 | and it won't be truncated, record it. */ | |
5042 | ; | |
5043 | else | |
5044 | { | |
5045 | /* This is chosen so that the destination will be invalidated | |
5046 | but no new value will be recorded. | |
5047 | We must invalidate because sometimes constant | |
5048 | values can be recorded for bitfields. */ | |
5049 | sets[i].src_elt = 0; | |
5050 | sets[i].src_volatile = 1; | |
5051 | src_eqv = 0; | |
5052 | src_eqv_elt = 0; | |
5053 | } | |
5054 | } | |
5055 | ||
5056 | /* If only one set in a JUMP_INSN and it is now a no-op, we can delete | |
5057 | the insn. */ | |
5058 | else if (n_sets == 1 && dest == pc_rtx && src == pc_rtx) | |
5059 | { | |
ef178af3 | 5060 | /* One less use of the label this insn used to jump to. */ |
0129d079 | 5061 | delete_insn_and_edges (insn); |
7afe21cc | 5062 | cse_jumps_altered = 1; |
7afe21cc RK |
5063 | /* No more processing for this set. */ |
5064 | sets[i].rtl = 0; | |
5065 | } | |
5066 | ||
5067 | /* If this SET is now setting PC to a label, we know it used to | |
d466c016 | 5068 | be a conditional or computed branch. */ |
8f235343 JH |
5069 | else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF |
5070 | && !LABEL_REF_NONLOCAL_P (src)) | |
7afe21cc | 5071 | { |
8fb1e50e GS |
5072 | /* Now emit a BARRIER after the unconditional jump. */ |
5073 | if (NEXT_INSN (insn) == 0 | |
4b4bf941 | 5074 | || !BARRIER_P (NEXT_INSN (insn))) |
8fb1e50e GS |
5075 | emit_barrier_after (insn); |
5076 | ||
d466c016 JL |
5077 | /* We reemit the jump in as many cases as possible just in |
5078 | case the form of an unconditional jump is significantly | |
5079 | different than a computed jump or conditional jump. | |
5080 | ||
5081 | If this insn has multiple sets, then reemitting the | |
5082 | jump is nontrivial. So instead we just force rerecognition | |
5083 | and hope for the best. */ | |
5084 | if (n_sets == 1) | |
7afe21cc | 5085 | { |
9dcb4381 | 5086 | rtx new, note; |
8fb1e50e | 5087 | |
0129d079 | 5088 | new = emit_jump_insn_before (gen_jump (XEXP (src, 0)), insn); |
7afe21cc RK |
5089 | JUMP_LABEL (new) = XEXP (src, 0); |
5090 | LABEL_NUSES (XEXP (src, 0))++; | |
9dcb4381 RH |
5091 | |
5092 | /* Make sure to copy over REG_NON_LOCAL_GOTO. */ | |
5093 | note = find_reg_note (insn, REG_NON_LOCAL_GOTO, 0); | |
5094 | if (note) | |
5095 | { | |
5096 | XEXP (note, 1) = NULL_RTX; | |
5097 | REG_NOTES (new) = note; | |
5098 | } | |
5099 | ||
0129d079 | 5100 | delete_insn_and_edges (insn); |
7afe21cc | 5101 | insn = new; |
8fb1e50e GS |
5102 | |
5103 | /* Now emit a BARRIER after the unconditional jump. */ | |
5104 | if (NEXT_INSN (insn) == 0 | |
4b4bf941 | 5105 | || !BARRIER_P (NEXT_INSN (insn))) |
8fb1e50e | 5106 | emit_barrier_after (insn); |
7afe21cc | 5107 | } |
31dcf83f | 5108 | else |
31dcf83f | 5109 | INSN_CODE (insn) = -1; |
7afe21cc | 5110 | |
8fb1e50e GS |
5111 | /* Do not bother deleting any unreachable code, |
5112 | let jump/flow do that. */ | |
7afe21cc RK |
5113 | |
5114 | cse_jumps_altered = 1; | |
5115 | sets[i].rtl = 0; | |
5116 | } | |
5117 | ||
c2a47e48 RK |
5118 | /* If destination is volatile, invalidate it and then do no further |
5119 | processing for this assignment. */ | |
7afe21cc RK |
5120 | |
5121 | else if (do_not_record) | |
c2a47e48 | 5122 | { |
f8cfc6aa | 5123 | if (REG_P (dest) || GET_CODE (dest) == SUBREG) |
bb4034b3 | 5124 | invalidate (dest, VOIDmode); |
3c0cb5de | 5125 | else if (MEM_P (dest)) |
32fab725 | 5126 | invalidate (dest, VOIDmode); |
2708da92 RS |
5127 | else if (GET_CODE (dest) == STRICT_LOW_PART |
5128 | || GET_CODE (dest) == ZERO_EXTRACT) | |
bb4034b3 | 5129 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
c2a47e48 RK |
5130 | sets[i].rtl = 0; |
5131 | } | |
7afe21cc RK |
5132 | |
5133 | if (sets[i].rtl != 0 && dest != SET_DEST (sets[i].rtl)) | |
2197a88a | 5134 | sets[i].dest_hash = HASH (SET_DEST (sets[i].rtl), mode); |
7afe21cc RK |
5135 | |
5136 | #ifdef HAVE_cc0 | |
5137 | /* If setting CC0, record what it was set to, or a constant, if it | |
5138 | is equivalent to a constant. If it is being set to a floating-point | |
5139 | value, make a COMPARE with the appropriate constant of 0. If we | |
5140 | don't do this, later code can interpret this as a test against | |
5141 | const0_rtx, which can cause problems if we try to put it into an | |
5142 | insn as a floating-point operand. */ | |
5143 | if (dest == cc0_rtx) | |
5144 | { | |
5145 | this_insn_cc0 = src_const && mode != VOIDmode ? src_const : src; | |
5146 | this_insn_cc0_mode = mode; | |
cbf6a543 | 5147 | if (FLOAT_MODE_P (mode)) |
38a448ca RH |
5148 | this_insn_cc0 = gen_rtx_COMPARE (VOIDmode, this_insn_cc0, |
5149 | CONST0_RTX (mode)); | |
7afe21cc RK |
5150 | } |
5151 | #endif | |
5152 | } | |
5153 | ||
5154 | /* Now enter all non-volatile source expressions in the hash table | |
5155 | if they are not already present. | |
5156 | Record their equivalence classes in src_elt. | |
5157 | This way we can insert the corresponding destinations into | |
5158 | the same classes even if the actual sources are no longer in them | |
5159 | (having been invalidated). */ | |
5160 | ||
5161 | if (src_eqv && src_eqv_elt == 0 && sets[0].rtl != 0 && ! src_eqv_volatile | |
5162 | && ! rtx_equal_p (src_eqv, SET_DEST (sets[0].rtl))) | |
5163 | { | |
b3694847 SS |
5164 | struct table_elt *elt; |
5165 | struct table_elt *classp = sets[0].src_elt; | |
7afe21cc RK |
5166 | rtx dest = SET_DEST (sets[0].rtl); |
5167 | enum machine_mode eqvmode = GET_MODE (dest); | |
5168 | ||
5169 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
5170 | { | |
5171 | eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0))); | |
5172 | classp = 0; | |
5173 | } | |
5174 | if (insert_regs (src_eqv, classp, 0)) | |
8ae2b8f6 JW |
5175 | { |
5176 | rehash_using_reg (src_eqv); | |
5177 | src_eqv_hash = HASH (src_eqv, eqvmode); | |
5178 | } | |
2197a88a | 5179 | elt = insert (src_eqv, classp, src_eqv_hash, eqvmode); |
7afe21cc | 5180 | elt->in_memory = src_eqv_in_memory; |
7afe21cc | 5181 | src_eqv_elt = elt; |
f7911249 JW |
5182 | |
5183 | /* Check to see if src_eqv_elt is the same as a set source which | |
5184 | does not yet have an elt, and if so set the elt of the set source | |
5185 | to src_eqv_elt. */ | |
5186 | for (i = 0; i < n_sets; i++) | |
26132f71 JW |
5187 | if (sets[i].rtl && sets[i].src_elt == 0 |
5188 | && rtx_equal_p (SET_SRC (sets[i].rtl), src_eqv)) | |
f7911249 | 5189 | sets[i].src_elt = src_eqv_elt; |
7afe21cc RK |
5190 | } |
5191 | ||
5192 | for (i = 0; i < n_sets; i++) | |
5193 | if (sets[i].rtl && ! sets[i].src_volatile | |
5194 | && ! rtx_equal_p (SET_SRC (sets[i].rtl), SET_DEST (sets[i].rtl))) | |
5195 | { | |
5196 | if (GET_CODE (SET_DEST (sets[i].rtl)) == STRICT_LOW_PART) | |
5197 | { | |
5198 | /* REG_EQUAL in setting a STRICT_LOW_PART | |
5199 | gives an equivalent for the entire destination register, | |
5200 | not just for the subreg being stored in now. | |
5201 | This is a more interesting equivalence, so we arrange later | |
5202 | to treat the entire reg as the destination. */ | |
5203 | sets[i].src_elt = src_eqv_elt; | |
2197a88a | 5204 | sets[i].src_hash = src_eqv_hash; |
7afe21cc RK |
5205 | } |
5206 | else | |
5207 | { | |
5208 | /* Insert source and constant equivalent into hash table, if not | |
5209 | already present. */ | |
b3694847 SS |
5210 | struct table_elt *classp = src_eqv_elt; |
5211 | rtx src = sets[i].src; | |
5212 | rtx dest = SET_DEST (sets[i].rtl); | |
7afe21cc RK |
5213 | enum machine_mode mode |
5214 | = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src); | |
5215 | ||
1fcc57f1 AM |
5216 | /* It's possible that we have a source value known to be |
5217 | constant but don't have a REG_EQUAL note on the insn. | |
5218 | Lack of a note will mean src_eqv_elt will be NULL. This | |
5219 | can happen where we've generated a SUBREG to access a | |
5220 | CONST_INT that is already in a register in a wider mode. | |
5221 | Ensure that the source expression is put in the proper | |
5222 | constant class. */ | |
5223 | if (!classp) | |
5224 | classp = sets[i].src_const_elt; | |
5225 | ||
26132f71 | 5226 | if (sets[i].src_elt == 0) |
7afe21cc | 5227 | { |
26132f71 JW |
5228 | /* Don't put a hard register source into the table if this is |
5229 | the last insn of a libcall. In this case, we only need | |
5230 | to put src_eqv_elt in src_elt. */ | |
db4a8254 | 5231 | if (! find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
8ae2b8f6 | 5232 | { |
b3694847 | 5233 | struct table_elt *elt; |
26132f71 JW |
5234 | |
5235 | /* Note that these insert_regs calls cannot remove | |
5236 | any of the src_elt's, because they would have failed to | |
5237 | match if not still valid. */ | |
5238 | if (insert_regs (src, classp, 0)) | |
5239 | { | |
5240 | rehash_using_reg (src); | |
5241 | sets[i].src_hash = HASH (src, mode); | |
5242 | } | |
5243 | elt = insert (src, classp, sets[i].src_hash, mode); | |
5244 | elt->in_memory = sets[i].src_in_memory; | |
26132f71 | 5245 | sets[i].src_elt = classp = elt; |
8ae2b8f6 | 5246 | } |
26132f71 JW |
5247 | else |
5248 | sets[i].src_elt = classp; | |
7afe21cc | 5249 | } |
7afe21cc RK |
5250 | if (sets[i].src_const && sets[i].src_const_elt == 0 |
5251 | && src != sets[i].src_const | |
5252 | && ! rtx_equal_p (sets[i].src_const, src)) | |
5253 | sets[i].src_elt = insert (sets[i].src_const, classp, | |
2197a88a | 5254 | sets[i].src_const_hash, mode); |
7afe21cc RK |
5255 | } |
5256 | } | |
5257 | else if (sets[i].src_elt == 0) | |
5258 | /* If we did not insert the source into the hash table (e.g., it was | |
5259 | volatile), note the equivalence class for the REG_EQUAL value, if any, | |
5260 | so that the destination goes into that class. */ | |
5261 | sets[i].src_elt = src_eqv_elt; | |
5262 | ||
05c433f3 PB |
5263 | /* Record destination addresses in the hash table. This allows us to |
5264 | check if they are invalidated by other sets. */ | |
5265 | for (i = 0; i < n_sets; i++) | |
5266 | { | |
5267 | if (sets[i].rtl) | |
5268 | { | |
5269 | rtx x = sets[i].inner_dest; | |
5270 | struct table_elt *elt; | |
5271 | enum machine_mode mode; | |
5272 | unsigned hash; | |
5273 | ||
5274 | if (MEM_P (x)) | |
5275 | { | |
5276 | x = XEXP (x, 0); | |
5277 | mode = GET_MODE (x); | |
5278 | hash = HASH (x, mode); | |
5279 | elt = lookup (x, hash, mode); | |
5280 | if (!elt) | |
5281 | { | |
5282 | if (insert_regs (x, NULL, 0)) | |
5283 | { | |
7e7e28c7 AO |
5284 | rtx dest = SET_DEST (sets[i].rtl); |
5285 | ||
05c433f3 PB |
5286 | rehash_using_reg (x); |
5287 | hash = HASH (x, mode); | |
7e7e28c7 | 5288 | sets[i].dest_hash = HASH (dest, GET_MODE (dest)); |
05c433f3 PB |
5289 | } |
5290 | elt = insert (x, NULL, hash, mode); | |
5291 | } | |
5292 | ||
5293 | sets[i].dest_addr_elt = elt; | |
5294 | } | |
5295 | else | |
5296 | sets[i].dest_addr_elt = NULL; | |
5297 | } | |
5298 | } | |
5299 | ||
9ae8ffe7 | 5300 | invalidate_from_clobbers (x); |
77fa0940 | 5301 | |
278a83b2 | 5302 | /* Some registers are invalidated by subroutine calls. Memory is |
77fa0940 RK |
5303 | invalidated by non-constant calls. */ |
5304 | ||
4b4bf941 | 5305 | if (CALL_P (insn)) |
7afe21cc | 5306 | { |
24a28584 | 5307 | if (! CONST_OR_PURE_CALL_P (insn)) |
9ae8ffe7 | 5308 | invalidate_memory (); |
7afe21cc RK |
5309 | invalidate_for_call (); |
5310 | } | |
5311 | ||
5312 | /* Now invalidate everything set by this instruction. | |
5313 | If a SUBREG or other funny destination is being set, | |
5314 | sets[i].rtl is still nonzero, so here we invalidate the reg | |
5315 | a part of which is being set. */ | |
5316 | ||
5317 | for (i = 0; i < n_sets; i++) | |
5318 | if (sets[i].rtl) | |
5319 | { | |
bb4034b3 JW |
5320 | /* We can't use the inner dest, because the mode associated with |
5321 | a ZERO_EXTRACT is significant. */ | |
b3694847 | 5322 | rtx dest = SET_DEST (sets[i].rtl); |
7afe21cc RK |
5323 | |
5324 | /* Needed for registers to remove the register from its | |
5325 | previous quantity's chain. | |
5326 | Needed for memory if this is a nonvarying address, unless | |
5327 | we have just done an invalidate_memory that covers even those. */ | |
f8cfc6aa | 5328 | if (REG_P (dest) || GET_CODE (dest) == SUBREG) |
bb4034b3 | 5329 | invalidate (dest, VOIDmode); |
3c0cb5de | 5330 | else if (MEM_P (dest)) |
32fab725 | 5331 | invalidate (dest, VOIDmode); |
2708da92 RS |
5332 | else if (GET_CODE (dest) == STRICT_LOW_PART |
5333 | || GET_CODE (dest) == ZERO_EXTRACT) | |
bb4034b3 | 5334 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
7afe21cc RK |
5335 | } |
5336 | ||
01e752d3 | 5337 | /* A volatile ASM invalidates everything. */ |
4b4bf941 | 5338 | if (NONJUMP_INSN_P (insn) |
01e752d3 JL |
5339 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS |
5340 | && MEM_VOLATILE_P (PATTERN (insn))) | |
5341 | flush_hash_table (); | |
5342 | ||
932ad4d9 SB |
5343 | /* Don't cse over a call to setjmp; on some machines (eg VAX) |
5344 | the regs restored by the longjmp come from a later time | |
5345 | than the setjmp. */ | |
5346 | if (CALL_P (insn) && find_reg_note (insn, REG_SETJMP, NULL)) | |
5347 | { | |
5348 | flush_hash_table (); | |
5349 | goto done; | |
5350 | } | |
5351 | ||
7afe21cc RK |
5352 | /* Make sure registers mentioned in destinations |
5353 | are safe for use in an expression to be inserted. | |
5354 | This removes from the hash table | |
5355 | any invalid entry that refers to one of these registers. | |
5356 | ||
5357 | We don't care about the return value from mention_regs because | |
5358 | we are going to hash the SET_DEST values unconditionally. */ | |
5359 | ||
5360 | for (i = 0; i < n_sets; i++) | |
34c73909 R |
5361 | { |
5362 | if (sets[i].rtl) | |
5363 | { | |
5364 | rtx x = SET_DEST (sets[i].rtl); | |
5365 | ||
f8cfc6aa | 5366 | if (!REG_P (x)) |
34c73909 R |
5367 | mention_regs (x); |
5368 | else | |
5369 | { | |
5370 | /* We used to rely on all references to a register becoming | |
5371 | inaccessible when a register changes to a new quantity, | |
5372 | since that changes the hash code. However, that is not | |
9b1549b8 | 5373 | safe, since after HASH_SIZE new quantities we get a |
34c73909 R |
5374 | hash 'collision' of a register with its own invalid |
5375 | entries. And since SUBREGs have been changed not to | |
5376 | change their hash code with the hash code of the register, | |
5377 | it wouldn't work any longer at all. So we have to check | |
5378 | for any invalid references lying around now. | |
5379 | This code is similar to the REG case in mention_regs, | |
5380 | but it knows that reg_tick has been incremented, and | |
5381 | it leaves reg_in_table as -1 . */ | |
770ae6cc RK |
5382 | unsigned int regno = REGNO (x); |
5383 | unsigned int endregno | |
34c73909 | 5384 | = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1 |
66fd46b6 | 5385 | : hard_regno_nregs[regno][GET_MODE (x)]); |
770ae6cc | 5386 | unsigned int i; |
34c73909 R |
5387 | |
5388 | for (i = regno; i < endregno; i++) | |
5389 | { | |
30f72379 | 5390 | if (REG_IN_TABLE (i) >= 0) |
34c73909 R |
5391 | { |
5392 | remove_invalid_refs (i); | |
30f72379 | 5393 | REG_IN_TABLE (i) = -1; |
34c73909 R |
5394 | } |
5395 | } | |
5396 | } | |
5397 | } | |
5398 | } | |
7afe21cc RK |
5399 | |
5400 | /* We may have just removed some of the src_elt's from the hash table. | |
05c433f3 PB |
5401 | So replace each one with the current head of the same class. |
5402 | Also check if destination addresses have been removed. */ | |
7afe21cc RK |
5403 | |
5404 | for (i = 0; i < n_sets; i++) | |
5405 | if (sets[i].rtl) | |
5406 | { | |
05c433f3 PB |
5407 | if (sets[i].dest_addr_elt |
5408 | && sets[i].dest_addr_elt->first_same_value == 0) | |
5409 | { | |
e67b81d1 | 5410 | /* The elt was removed, which means this destination is not |
05c433f3 PB |
5411 | valid after this instruction. */ |
5412 | sets[i].rtl = NULL_RTX; | |
5413 | } | |
5414 | else if (sets[i].src_elt && sets[i].src_elt->first_same_value == 0) | |
7afe21cc RK |
5415 | /* If elt was removed, find current head of same class, |
5416 | or 0 if nothing remains of that class. */ | |
5417 | { | |
b3694847 | 5418 | struct table_elt *elt = sets[i].src_elt; |
7afe21cc RK |
5419 | |
5420 | while (elt && elt->prev_same_value) | |
5421 | elt = elt->prev_same_value; | |
5422 | ||
5423 | while (elt && elt->first_same_value == 0) | |
5424 | elt = elt->next_same_value; | |
5425 | sets[i].src_elt = elt ? elt->first_same_value : 0; | |
5426 | } | |
5427 | } | |
5428 | ||
5429 | /* Now insert the destinations into their equivalence classes. */ | |
5430 | ||
5431 | for (i = 0; i < n_sets; i++) | |
5432 | if (sets[i].rtl) | |
5433 | { | |
b3694847 | 5434 | rtx dest = SET_DEST (sets[i].rtl); |
b3694847 | 5435 | struct table_elt *elt; |
7afe21cc RK |
5436 | |
5437 | /* Don't record value if we are not supposed to risk allocating | |
5438 | floating-point values in registers that might be wider than | |
5439 | memory. */ | |
5440 | if ((flag_float_store | |
3c0cb5de | 5441 | && MEM_P (dest) |
cbf6a543 | 5442 | && FLOAT_MODE_P (GET_MODE (dest))) |
bc4ddc77 JW |
5443 | /* Don't record BLKmode values, because we don't know the |
5444 | size of it, and can't be sure that other BLKmode values | |
5445 | have the same or smaller size. */ | |
5446 | || GET_MODE (dest) == BLKmode | |
7afe21cc RK |
5447 | /* Don't record values of destinations set inside a libcall block |
5448 | since we might delete the libcall. Things should have been set | |
5449 | up so we won't want to reuse such a value, but we play it safe | |
5450 | here. */ | |
7bd8b2a8 | 5451 | || libcall_insn |
7afe21cc RK |
5452 | /* If we didn't put a REG_EQUAL value or a source into the hash |
5453 | table, there is no point is recording DEST. */ | |
1a8e9a8e RK |
5454 | || sets[i].src_elt == 0 |
5455 | /* If DEST is a paradoxical SUBREG and SRC is a ZERO_EXTEND | |
5456 | or SIGN_EXTEND, don't record DEST since it can cause | |
5457 | some tracking to be wrong. | |
5458 | ||
5459 | ??? Think about this more later. */ | |
5460 | || (GET_CODE (dest) == SUBREG | |
5461 | && (GET_MODE_SIZE (GET_MODE (dest)) | |
5462 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))) | |
5463 | && (GET_CODE (sets[i].src) == SIGN_EXTEND | |
5464 | || GET_CODE (sets[i].src) == ZERO_EXTEND))) | |
7afe21cc RK |
5465 | continue; |
5466 | ||
5467 | /* STRICT_LOW_PART isn't part of the value BEING set, | |
5468 | and neither is the SUBREG inside it. | |
5469 | Note that in this case SETS[I].SRC_ELT is really SRC_EQV_ELT. */ | |
5470 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
5471 | dest = SUBREG_REG (XEXP (dest, 0)); | |
5472 | ||
f8cfc6aa | 5473 | if (REG_P (dest) || GET_CODE (dest) == SUBREG) |
7afe21cc RK |
5474 | /* Registers must also be inserted into chains for quantities. */ |
5475 | if (insert_regs (dest, sets[i].src_elt, 1)) | |
8ae2b8f6 JW |
5476 | { |
5477 | /* If `insert_regs' changes something, the hash code must be | |
5478 | recalculated. */ | |
5479 | rehash_using_reg (dest); | |
5480 | sets[i].dest_hash = HASH (dest, GET_MODE (dest)); | |
5481 | } | |
7afe21cc | 5482 | |
8fff4fc1 RH |
5483 | elt = insert (dest, sets[i].src_elt, |
5484 | sets[i].dest_hash, GET_MODE (dest)); | |
9de2c71a | 5485 | |
3c0cb5de | 5486 | elt->in_memory = (MEM_P (sets[i].inner_dest) |
389fdba0 | 5487 | && !MEM_READONLY_P (sets[i].inner_dest)); |
c256df0b | 5488 | |
fc3ffe83 RK |
5489 | /* If we have (set (subreg:m1 (reg:m2 foo) 0) (bar:m1)), M1 is no |
5490 | narrower than M2, and both M1 and M2 are the same number of words, | |
5491 | we are also doing (set (reg:m2 foo) (subreg:m2 (bar:m1) 0)) so | |
5492 | make that equivalence as well. | |
7afe21cc | 5493 | |
4de249d9 PB |
5494 | However, BAR may have equivalences for which gen_lowpart |
5495 | will produce a simpler value than gen_lowpart applied to | |
7afe21cc | 5496 | BAR (e.g., if BAR was ZERO_EXTENDed from M2), so we will scan all |
278a83b2 | 5497 | BAR's equivalences. If we don't get a simplified form, make |
7afe21cc RK |
5498 | the SUBREG. It will not be used in an equivalence, but will |
5499 | cause two similar assignments to be detected. | |
5500 | ||
5501 | Note the loop below will find SUBREG_REG (DEST) since we have | |
5502 | already entered SRC and DEST of the SET in the table. */ | |
5503 | ||
5504 | if (GET_CODE (dest) == SUBREG | |
6cdbaec4 RK |
5505 | && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) - 1) |
5506 | / UNITS_PER_WORD) | |
278a83b2 | 5507 | == (GET_MODE_SIZE (GET_MODE (dest)) - 1) / UNITS_PER_WORD) |
7afe21cc RK |
5508 | && (GET_MODE_SIZE (GET_MODE (dest)) |
5509 | >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))) | |
5510 | && sets[i].src_elt != 0) | |
5511 | { | |
5512 | enum machine_mode new_mode = GET_MODE (SUBREG_REG (dest)); | |
5513 | struct table_elt *elt, *classp = 0; | |
5514 | ||
5515 | for (elt = sets[i].src_elt->first_same_value; elt; | |
5516 | elt = elt->next_same_value) | |
5517 | { | |
5518 | rtx new_src = 0; | |
2197a88a | 5519 | unsigned src_hash; |
7afe21cc | 5520 | struct table_elt *src_elt; |
ff27a429 | 5521 | int byte = 0; |
7afe21cc RK |
5522 | |
5523 | /* Ignore invalid entries. */ | |
f8cfc6aa | 5524 | if (!REG_P (elt->exp) |
0516f6fe | 5525 | && ! exp_equiv_p (elt->exp, elt->exp, 1, false)) |
7afe21cc RK |
5526 | continue; |
5527 | ||
9beb7d20 RH |
5528 | /* We may have already been playing subreg games. If the |
5529 | mode is already correct for the destination, use it. */ | |
5530 | if (GET_MODE (elt->exp) == new_mode) | |
5531 | new_src = elt->exp; | |
5532 | else | |
5533 | { | |
5534 | /* Calculate big endian correction for the SUBREG_BYTE. | |
5535 | We have already checked that M1 (GET_MODE (dest)) | |
5536 | is not narrower than M2 (new_mode). */ | |
5537 | if (BYTES_BIG_ENDIAN) | |
5538 | byte = (GET_MODE_SIZE (GET_MODE (dest)) | |
5539 | - GET_MODE_SIZE (new_mode)); | |
5540 | ||
5541 | new_src = simplify_gen_subreg (new_mode, elt->exp, | |
5542 | GET_MODE (dest), byte); | |
5543 | } | |
5544 | ||
ff27a429 R |
5545 | /* The call to simplify_gen_subreg fails if the value |
5546 | is VOIDmode, yet we can't do any simplification, e.g. | |
5547 | for EXPR_LISTs denoting function call results. | |
5548 | It is invalid to construct a SUBREG with a VOIDmode | |
5549 | SUBREG_REG, hence a zero new_src means we can't do | |
5550 | this substitution. */ | |
5551 | if (! new_src) | |
5552 | continue; | |
7afe21cc RK |
5553 | |
5554 | src_hash = HASH (new_src, new_mode); | |
5555 | src_elt = lookup (new_src, src_hash, new_mode); | |
5556 | ||
5557 | /* Put the new source in the hash table is if isn't | |
5558 | already. */ | |
5559 | if (src_elt == 0) | |
5560 | { | |
5561 | if (insert_regs (new_src, classp, 0)) | |
8ae2b8f6 JW |
5562 | { |
5563 | rehash_using_reg (new_src); | |
5564 | src_hash = HASH (new_src, new_mode); | |
5565 | } | |
7afe21cc RK |
5566 | src_elt = insert (new_src, classp, src_hash, new_mode); |
5567 | src_elt->in_memory = elt->in_memory; | |
7afe21cc RK |
5568 | } |
5569 | else if (classp && classp != src_elt->first_same_value) | |
278a83b2 | 5570 | /* Show that two things that we've seen before are |
7afe21cc RK |
5571 | actually the same. */ |
5572 | merge_equiv_classes (src_elt, classp); | |
5573 | ||
5574 | classp = src_elt->first_same_value; | |
da932f04 JL |
5575 | /* Ignore invalid entries. */ |
5576 | while (classp | |
f8cfc6aa | 5577 | && !REG_P (classp->exp) |
0516f6fe | 5578 | && ! exp_equiv_p (classp->exp, classp->exp, 1, false)) |
da932f04 | 5579 | classp = classp->next_same_value; |
7afe21cc RK |
5580 | } |
5581 | } | |
5582 | } | |
5583 | ||
403e25d0 RK |
5584 | /* Special handling for (set REG0 REG1) where REG0 is the |
5585 | "cheapest", cheaper than REG1. After cse, REG1 will probably not | |
5586 | be used in the sequel, so (if easily done) change this insn to | |
5587 | (set REG1 REG0) and replace REG1 with REG0 in the previous insn | |
5588 | that computed their value. Then REG1 will become a dead store | |
5589 | and won't cloud the situation for later optimizations. | |
7afe21cc RK |
5590 | |
5591 | Do not make this change if REG1 is a hard register, because it will | |
5592 | then be used in the sequel and we may be changing a two-operand insn | |
5593 | into a three-operand insn. | |
5594 | ||
50270076 R |
5595 | Also do not do this if we are operating on a copy of INSN. |
5596 | ||
5597 | Also don't do this if INSN ends a libcall; this would cause an unrelated | |
5598 | register to be set in the middle of a libcall, and we then get bad code | |
5599 | if the libcall is deleted. */ | |
7afe21cc | 5600 | |
f8cfc6aa | 5601 | if (n_sets == 1 && sets[0].rtl && REG_P (SET_DEST (sets[0].rtl)) |
7afe21cc | 5602 | && NEXT_INSN (PREV_INSN (insn)) == insn |
f8cfc6aa | 5603 | && REG_P (SET_SRC (sets[0].rtl)) |
7afe21cc | 5604 | && REGNO (SET_SRC (sets[0].rtl)) >= FIRST_PSEUDO_REGISTER |
1bb98cec | 5605 | && REGNO_QTY_VALID_P (REGNO (SET_SRC (sets[0].rtl)))) |
7afe21cc | 5606 | { |
1bb98cec DM |
5607 | int src_q = REG_QTY (REGNO (SET_SRC (sets[0].rtl))); |
5608 | struct qty_table_elem *src_ent = &qty_table[src_q]; | |
7afe21cc | 5609 | |
1bb98cec DM |
5610 | if ((src_ent->first_reg == REGNO (SET_DEST (sets[0].rtl))) |
5611 | && ! find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
7afe21cc | 5612 | { |
3e25353e AH |
5613 | /* Scan for the previous nonnote insn, but stop at a basic |
5614 | block boundary. */ | |
932ad4d9 SB |
5615 | rtx prev = insn; |
5616 | rtx bb_head = BB_HEAD (BLOCK_FOR_INSN (insn)); | |
3e25353e AH |
5617 | do |
5618 | { | |
5619 | prev = PREV_INSN (prev); | |
5620 | } | |
932ad4d9 | 5621 | while (prev != bb_head && NOTE_P (prev)); |
7080f735 | 5622 | |
58ecb5e2 RS |
5623 | /* Do not swap the registers around if the previous instruction |
5624 | attaches a REG_EQUIV note to REG1. | |
5625 | ||
5626 | ??? It's not entirely clear whether we can transfer a REG_EQUIV | |
5627 | from the pseudo that originally shadowed an incoming argument | |
5628 | to another register. Some uses of REG_EQUIV might rely on it | |
5629 | being attached to REG1 rather than REG2. | |
5630 | ||
5631 | This section previously turned the REG_EQUIV into a REG_EQUAL | |
5632 | note. We cannot do that because REG_EQUIV may provide an | |
4912a07c | 5633 | uninitialized stack slot when REG_PARM_STACK_SPACE is used. */ |
932ad4d9 | 5634 | if (NONJUMP_INSN_P (prev) |
403e25d0 | 5635 | && GET_CODE (PATTERN (prev)) == SET |
58ecb5e2 RS |
5636 | && SET_DEST (PATTERN (prev)) == SET_SRC (sets[0].rtl) |
5637 | && ! find_reg_note (prev, REG_EQUIV, NULL_RTX)) | |
1bb98cec DM |
5638 | { |
5639 | rtx dest = SET_DEST (sets[0].rtl); | |
403e25d0 | 5640 | rtx src = SET_SRC (sets[0].rtl); |
58ecb5e2 | 5641 | rtx note; |
7afe21cc | 5642 | |
278a83b2 KH |
5643 | validate_change (prev, &SET_DEST (PATTERN (prev)), dest, 1); |
5644 | validate_change (insn, &SET_DEST (sets[0].rtl), src, 1); | |
5645 | validate_change (insn, &SET_SRC (sets[0].rtl), dest, 1); | |
1bb98cec | 5646 | apply_change_group (); |
7afe21cc | 5647 | |
403e25d0 RK |
5648 | /* If INSN has a REG_EQUAL note, and this note mentions |
5649 | REG0, then we must delete it, because the value in | |
5650 | REG0 has changed. If the note's value is REG1, we must | |
5651 | also delete it because that is now this insn's dest. */ | |
1bb98cec | 5652 | note = find_reg_note (insn, REG_EQUAL, NULL_RTX); |
403e25d0 RK |
5653 | if (note != 0 |
5654 | && (reg_mentioned_p (dest, XEXP (note, 0)) | |
5655 | || rtx_equal_p (src, XEXP (note, 0)))) | |
1bb98cec DM |
5656 | remove_note (insn, note); |
5657 | } | |
7afe21cc RK |
5658 | } |
5659 | } | |
5660 | ||
932ad4d9 | 5661 | done:; |
7afe21cc RK |
5662 | } |
5663 | \f | |
a4c6502a | 5664 | /* Remove from the hash table all expressions that reference memory. */ |
14a774a9 | 5665 | |
7afe21cc | 5666 | static void |
7080f735 | 5667 | invalidate_memory (void) |
7afe21cc | 5668 | { |
b3694847 SS |
5669 | int i; |
5670 | struct table_elt *p, *next; | |
7afe21cc | 5671 | |
9b1549b8 | 5672 | for (i = 0; i < HASH_SIZE; i++) |
9ae8ffe7 JL |
5673 | for (p = table[i]; p; p = next) |
5674 | { | |
5675 | next = p->next_same_hash; | |
5676 | if (p->in_memory) | |
5677 | remove_from_table (p, i); | |
5678 | } | |
5679 | } | |
5680 | ||
7afe21cc RK |
5681 | /* Perform invalidation on the basis of everything about an insn |
5682 | except for invalidating the actual places that are SET in it. | |
5683 | This includes the places CLOBBERed, and anything that might | |
5684 | alias with something that is SET or CLOBBERed. | |
5685 | ||
7afe21cc RK |
5686 | X is the pattern of the insn. */ |
5687 | ||
5688 | static void | |
7080f735 | 5689 | invalidate_from_clobbers (rtx x) |
7afe21cc | 5690 | { |
7afe21cc RK |
5691 | if (GET_CODE (x) == CLOBBER) |
5692 | { | |
5693 | rtx ref = XEXP (x, 0); | |
9ae8ffe7 JL |
5694 | if (ref) |
5695 | { | |
f8cfc6aa | 5696 | if (REG_P (ref) || GET_CODE (ref) == SUBREG |
3c0cb5de | 5697 | || MEM_P (ref)) |
9ae8ffe7 JL |
5698 | invalidate (ref, VOIDmode); |
5699 | else if (GET_CODE (ref) == STRICT_LOW_PART | |
5700 | || GET_CODE (ref) == ZERO_EXTRACT) | |
5701 | invalidate (XEXP (ref, 0), GET_MODE (ref)); | |
5702 | } | |
7afe21cc RK |
5703 | } |
5704 | else if (GET_CODE (x) == PARALLEL) | |
5705 | { | |
b3694847 | 5706 | int i; |
7afe21cc RK |
5707 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) |
5708 | { | |
b3694847 | 5709 | rtx y = XVECEXP (x, 0, i); |
7afe21cc RK |
5710 | if (GET_CODE (y) == CLOBBER) |
5711 | { | |
5712 | rtx ref = XEXP (y, 0); | |
f8cfc6aa | 5713 | if (REG_P (ref) || GET_CODE (ref) == SUBREG |
3c0cb5de | 5714 | || MEM_P (ref)) |
9ae8ffe7 JL |
5715 | invalidate (ref, VOIDmode); |
5716 | else if (GET_CODE (ref) == STRICT_LOW_PART | |
5717 | || GET_CODE (ref) == ZERO_EXTRACT) | |
5718 | invalidate (XEXP (ref, 0), GET_MODE (ref)); | |
7afe21cc RK |
5719 | } |
5720 | } | |
5721 | } | |
5722 | } | |
5723 | \f | |
5724 | /* Process X, part of the REG_NOTES of an insn. Look at any REG_EQUAL notes | |
5725 | and replace any registers in them with either an equivalent constant | |
5726 | or the canonical form of the register. If we are inside an address, | |
5727 | only do this if the address remains valid. | |
5728 | ||
5729 | OBJECT is 0 except when within a MEM in which case it is the MEM. | |
5730 | ||
5731 | Return the replacement for X. */ | |
5732 | ||
5733 | static rtx | |
7080f735 | 5734 | cse_process_notes (rtx x, rtx object) |
7afe21cc RK |
5735 | { |
5736 | enum rtx_code code = GET_CODE (x); | |
6f7d635c | 5737 | const char *fmt = GET_RTX_FORMAT (code); |
7afe21cc RK |
5738 | int i; |
5739 | ||
5740 | switch (code) | |
5741 | { | |
5742 | case CONST_INT: | |
5743 | case CONST: | |
5744 | case SYMBOL_REF: | |
5745 | case LABEL_REF: | |
5746 | case CONST_DOUBLE: | |
69ef87e2 | 5747 | case CONST_VECTOR: |
7afe21cc RK |
5748 | case PC: |
5749 | case CC0: | |
5750 | case LO_SUM: | |
5751 | return x; | |
5752 | ||
5753 | case MEM: | |
c96208fa DC |
5754 | validate_change (x, &XEXP (x, 0), |
5755 | cse_process_notes (XEXP (x, 0), x), 0); | |
7afe21cc RK |
5756 | return x; |
5757 | ||
5758 | case EXPR_LIST: | |
5759 | case INSN_LIST: | |
5760 | if (REG_NOTE_KIND (x) == REG_EQUAL) | |
906c4e36 | 5761 | XEXP (x, 0) = cse_process_notes (XEXP (x, 0), NULL_RTX); |
7afe21cc | 5762 | if (XEXP (x, 1)) |
906c4e36 | 5763 | XEXP (x, 1) = cse_process_notes (XEXP (x, 1), NULL_RTX); |
7afe21cc RK |
5764 | return x; |
5765 | ||
e4890d45 RS |
5766 | case SIGN_EXTEND: |
5767 | case ZERO_EXTEND: | |
0b0ee36c | 5768 | case SUBREG: |
e4890d45 RS |
5769 | { |
5770 | rtx new = cse_process_notes (XEXP (x, 0), object); | |
5771 | /* We don't substitute VOIDmode constants into these rtx, | |
5772 | since they would impede folding. */ | |
5773 | if (GET_MODE (new) != VOIDmode) | |
5774 | validate_change (object, &XEXP (x, 0), new, 0); | |
5775 | return x; | |
5776 | } | |
5777 | ||
7afe21cc | 5778 | case REG: |
30f72379 | 5779 | i = REG_QTY (REGNO (x)); |
7afe21cc RK |
5780 | |
5781 | /* Return a constant or a constant register. */ | |
1bb98cec | 5782 | if (REGNO_QTY_VALID_P (REGNO (x))) |
7afe21cc | 5783 | { |
1bb98cec DM |
5784 | struct qty_table_elem *ent = &qty_table[i]; |
5785 | ||
5786 | if (ent->const_rtx != NULL_RTX | |
5787 | && (CONSTANT_P (ent->const_rtx) | |
f8cfc6aa | 5788 | || REG_P (ent->const_rtx))) |
1bb98cec | 5789 | { |
4de249d9 | 5790 | rtx new = gen_lowpart (GET_MODE (x), ent->const_rtx); |
1bb98cec | 5791 | if (new) |
3e916873 | 5792 | return copy_rtx (new); |
1bb98cec | 5793 | } |
7afe21cc RK |
5794 | } |
5795 | ||
5796 | /* Otherwise, canonicalize this register. */ | |
906c4e36 | 5797 | return canon_reg (x, NULL_RTX); |
278a83b2 | 5798 | |
e9a25f70 JL |
5799 | default: |
5800 | break; | |
7afe21cc RK |
5801 | } |
5802 | ||
5803 | for (i = 0; i < GET_RTX_LENGTH (code); i++) | |
5804 | if (fmt[i] == 'e') | |
5805 | validate_change (object, &XEXP (x, i), | |
7fe34fdf | 5806 | cse_process_notes (XEXP (x, i), object), 0); |
7afe21cc RK |
5807 | |
5808 | return x; | |
5809 | } | |
5810 | \f | |
932ad4d9 | 5811 | /* Find a path in the CFG, starting with FIRST_BB to perform CSE on. |
7afe21cc | 5812 | |
932ad4d9 SB |
5813 | DATA is a pointer to a struct cse_basic_block_data, that is used to |
5814 | describe the path. | |
5815 | It is filled with a queue of basic blocks, starting with FIRST_BB | |
5816 | and following a trace through the CFG. | |
5817 | ||
5818 | If all paths starting at FIRST_BB have been followed, or no new path | |
5819 | starting at FIRST_BB can be constructed, this function returns FALSE. | |
5820 | Otherwise, DATA->path is filled and the function returns TRUE indicating | |
5821 | that a path to follow was found. | |
7afe21cc | 5822 | |
2e226e66 | 5823 | If FOLLOW_JUMPS is false, the maximum path length is 1 and the only |
932ad4d9 | 5824 | block in the path will be FIRST_BB. */ |
7afe21cc | 5825 | |
932ad4d9 SB |
5826 | static bool |
5827 | cse_find_path (basic_block first_bb, struct cse_basic_block_data *data, | |
5828 | int follow_jumps) | |
7afe21cc | 5829 | { |
932ad4d9 SB |
5830 | basic_block bb; |
5831 | edge e; | |
5832 | int path_size; | |
5833 | ||
5834 | SET_BIT (cse_visited_basic_blocks, first_bb->index); | |
7afe21cc | 5835 | |
932ad4d9 SB |
5836 | /* See if there is a previous path. */ |
5837 | path_size = data->path_size; | |
5838 | ||
5839 | /* There is a previous path. Make sure it started with FIRST_BB. */ | |
5840 | if (path_size) | |
5841 | gcc_assert (data->path[0].bb == first_bb); | |
5842 | ||
5843 | /* There was only one basic block in the last path. Clear the path and | |
5844 | return, so that paths starting at another basic block can be tried. */ | |
5845 | if (path_size == 1) | |
5846 | { | |
5847 | path_size = 0; | |
5848 | goto done; | |
5849 | } | |
5850 | ||
5851 | /* If the path was empty from the beginning, construct a new path. */ | |
5852 | if (path_size == 0) | |
5853 | data->path[path_size++].bb = first_bb; | |
5854 | else | |
7afe21cc | 5855 | { |
932ad4d9 SB |
5856 | /* Otherwise, path_size must be equal to or greater than 2, because |
5857 | a previous path exists that is at least two basic blocks long. | |
5858 | ||
5859 | Update the previous branch path, if any. If the last branch was | |
5860 | previously along the branch edge, take the fallthrough edge now. */ | |
5861 | while (path_size >= 2) | |
7afe21cc | 5862 | { |
932ad4d9 SB |
5863 | basic_block last_bb_in_path, previous_bb_in_path; |
5864 | edge e; | |
5865 | ||
5866 | --path_size; | |
5867 | last_bb_in_path = data->path[path_size].bb; | |
5868 | previous_bb_in_path = data->path[path_size - 1].bb; | |
5869 | ||
5870 | /* If we previously followed a path along the branch edge, try | |
5871 | the fallthru edge now. */ | |
5872 | if (EDGE_COUNT (previous_bb_in_path->succs) == 2 | |
5873 | && any_condjump_p (BB_END (previous_bb_in_path)) | |
5874 | && (e = find_edge (previous_bb_in_path, last_bb_in_path)) | |
5875 | && e == BRANCH_EDGE (previous_bb_in_path)) | |
5876 | { | |
5877 | bb = FALLTHRU_EDGE (previous_bb_in_path)->dest; | |
5878 | if (bb != EXIT_BLOCK_PTR | |
5879 | && single_pred_p (bb)) | |
5880 | { | |
5881 | #if ENABLE_CHECKING | |
5882 | /* We should only see blocks here that we have not | |
5883 | visited yet. */ | |
5884 | gcc_assert (!TEST_BIT (cse_visited_basic_blocks, bb->index)); | |
5885 | #endif | |
5886 | SET_BIT (cse_visited_basic_blocks, bb->index); | |
5887 | data->path[path_size++].bb = bb; | |
5888 | break; | |
5889 | } | |
5890 | } | |
5891 | ||
5892 | data->path[path_size].bb = NULL; | |
5893 | } | |
5894 | ||
5895 | /* If only one block remains in the path, bail. */ | |
5896 | if (path_size == 1) | |
5897 | { | |
5898 | path_size = 0; | |
5899 | goto done; | |
7afe21cc | 5900 | } |
7afe21cc RK |
5901 | } |
5902 | ||
932ad4d9 SB |
5903 | /* Extend the path if possible. */ |
5904 | if (follow_jumps) | |
7afe21cc | 5905 | { |
932ad4d9 SB |
5906 | bb = data->path[path_size - 1].bb; |
5907 | while (bb && path_size < PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH)) | |
5908 | { | |
5909 | if (single_succ_p (bb)) | |
5910 | e = single_succ_edge (bb); | |
5911 | else if (EDGE_COUNT (bb->succs) == 2 | |
5912 | && any_condjump_p (BB_END (bb))) | |
5913 | { | |
5914 | /* First try to follow the branch. If that doesn't lead | |
5915 | to a useful path, follow the fallthru edge. */ | |
5916 | e = BRANCH_EDGE (bb); | |
5917 | if (!single_pred_p (e->dest)) | |
5918 | e = FALLTHRU_EDGE (bb); | |
5919 | } | |
5920 | else | |
5921 | e = NULL; | |
7afe21cc | 5922 | |
932ad4d9 SB |
5923 | if (e && e->dest != EXIT_BLOCK_PTR |
5924 | && single_pred_p (e->dest)) | |
5925 | { | |
5926 | basic_block bb2 = e->dest; | |
278a83b2 | 5927 | |
932ad4d9 SB |
5928 | /* We should only see blocks here that we have not |
5929 | visited yet. */ | |
5930 | gcc_assert (!TEST_BIT (cse_visited_basic_blocks, bb2->index)); | |
27511c65 | 5931 | |
932ad4d9 SB |
5932 | SET_BIT (cse_visited_basic_blocks, bb2->index); |
5933 | data->path[path_size++].bb = bb2; | |
5934 | bb = bb2; | |
5935 | } | |
5936 | else | |
5937 | bb = NULL; | |
5938 | } | |
5939 | } | |
5940 | ||
5941 | done: | |
5942 | data->path_size = path_size; | |
5943 | return path_size != 0; | |
5944 | } | |
5945 | \f | |
5946 | /* Dump the path in DATA to file F. NSETS is the number of sets | |
5947 | in the path. */ | |
5948 | ||
5949 | static void | |
5950 | cse_dump_path (struct cse_basic_block_data *data, int nsets, FILE *f) | |
5951 | { | |
5952 | int path_entry; | |
5953 | ||
5954 | fprintf (f, ";; Following path with %d sets: ", nsets); | |
5955 | for (path_entry = 0; path_entry < data->path_size; path_entry++) | |
5956 | fprintf (f, "%d ", (data->path[path_entry].bb)->index); | |
5957 | fputc ('\n', dump_file); | |
5958 | fflush (f); | |
5959 | } | |
5960 | ||
a7582f7c SB |
5961 | \f |
5962 | /* Return true if BB has exception handling successor edges. */ | |
5963 | ||
5964 | static bool | |
5965 | have_eh_succ_edges (basic_block bb) | |
5966 | { | |
5967 | edge e; | |
5968 | edge_iterator ei; | |
5969 | ||
5970 | FOR_EACH_EDGE (e, ei, bb->succs) | |
5971 | if (e->flags & EDGE_EH) | |
5972 | return true; | |
5973 | ||
5974 | return false; | |
5975 | } | |
5976 | ||
932ad4d9 SB |
5977 | \f |
5978 | /* Scan to the end of the path described by DATA. Return an estimate of | |
5979 | the total number of SETs, and the lowest and highest insn CUID, of all | |
5980 | insns in the path. */ | |
5981 | ||
5982 | static void | |
5983 | cse_prescan_path (struct cse_basic_block_data *data) | |
5984 | { | |
5985 | int nsets = 0; | |
5986 | int low_cuid = -1, high_cuid = -1; /* FIXME low_cuid not computed correctly */ | |
5987 | int path_size = data->path_size; | |
5988 | int path_entry; | |
5989 | ||
5990 | /* Scan to end of each basic block in the path. */ | |
5991 | for (path_entry = 0; path_entry < path_size; path_entry++) | |
5992 | { | |
5993 | basic_block bb; | |
5994 | rtx insn; | |
164c8956 | 5995 | |
932ad4d9 | 5996 | bb = data->path[path_entry].bb; |
7afe21cc | 5997 | |
932ad4d9 | 5998 | FOR_BB_INSNS (bb, insn) |
7afe21cc | 5999 | { |
932ad4d9 SB |
6000 | if (!INSN_P (insn)) |
6001 | continue; | |
278a83b2 | 6002 | |
932ad4d9 SB |
6003 | /* A PARALLEL can have lots of SETs in it, |
6004 | especially if it is really an ASM_OPERANDS. */ | |
6005 | if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
6006 | nsets += XVECLEN (PATTERN (insn), 0); | |
6007 | else | |
6008 | nsets += 1; | |
6009 | ||
6010 | /* Ignore insns made by CSE in a previous traversal of this | |
6011 | basic block. They cannot affect the boundaries of the | |
6012 | basic block. | |
6013 | FIXME: When we only visit each basic block at most once, | |
6014 | this can go away. */ | |
6015 | if (INSN_UID (insn) <= max_uid && INSN_CUID (insn) > high_cuid) | |
6016 | high_cuid = INSN_CUID (insn); | |
6017 | if (INSN_UID (insn) <= max_uid && INSN_CUID (insn) < low_cuid) | |
6018 | low_cuid = INSN_CUID (insn); | |
7afe21cc | 6019 | } |
932ad4d9 SB |
6020 | } |
6021 | ||
6022 | data->low_cuid = low_cuid; | |
6023 | data->high_cuid = high_cuid; | |
6024 | data->nsets = nsets; | |
6025 | } | |
6026 | \f | |
6027 | /* Process a single extended basic block described by EBB_DATA. */ | |
7afe21cc | 6028 | |
932ad4d9 SB |
6029 | static void |
6030 | cse_extended_basic_block (struct cse_basic_block_data *ebb_data) | |
6031 | { | |
6032 | int path_size = ebb_data->path_size; | |
6033 | int path_entry; | |
6034 | int num_insns = 0; | |
6035 | ||
6036 | /* Allocate the space needed by qty_table. */ | |
6037 | qty_table = XNEWVEC (struct qty_table_elem, max_qty); | |
6038 | ||
6039 | new_basic_block (); | |
6040 | for (path_entry = 0; path_entry < path_size; path_entry++) | |
6041 | { | |
6042 | basic_block bb; | |
6043 | rtx insn; | |
6044 | rtx libcall_insn = NULL_RTX; | |
6045 | int no_conflict = 0; | |
6046 | ||
6047 | bb = ebb_data->path[path_entry].bb; | |
6048 | FOR_BB_INSNS (bb, insn) | |
7afe21cc | 6049 | { |
932ad4d9 SB |
6050 | /* If we have processed 1,000 insns, flush the hash table to |
6051 | avoid extreme quadratic behavior. We must not include NOTEs | |
6052 | in the count since there may be more of them when generating | |
6053 | debugging information. If we clear the table at different | |
6054 | times, code generated with -g -O might be different than code | |
6055 | generated with -O but not -g. | |
6056 | ||
6057 | FIXME: This is a real kludge and needs to be done some other | |
6058 | way. */ | |
6059 | if (INSN_P (insn) | |
6060 | && num_insns++ > PARAM_VALUE (PARAM_MAX_CSE_INSNS)) | |
6061 | { | |
6062 | flush_hash_table (); | |
6063 | num_insns = 0; | |
6064 | } | |
7afe21cc | 6065 | |
932ad4d9 | 6066 | if (INSN_P (insn)) |
7afe21cc | 6067 | { |
932ad4d9 SB |
6068 | /* Process notes first so we have all notes in canonical forms |
6069 | when looking for duplicate operations. */ | |
6070 | if (REG_NOTES (insn)) | |
6071 | REG_NOTES (insn) = cse_process_notes (REG_NOTES (insn), | |
6072 | NULL_RTX); | |
6073 | ||
6074 | /* Track when we are inside in LIBCALL block. Inside such | |
6075 | a block we do not want to record destinations. The last | |
6076 | insn of a LIBCALL block is not considered to be part of | |
6077 | the block, since its destination is the result of the | |
6078 | block and hence should be recorded. */ | |
6079 | if (REG_NOTES (insn) != 0) | |
fc3ffe83 | 6080 | { |
932ad4d9 SB |
6081 | rtx p; |
6082 | ||
6083 | if ((p = find_reg_note (insn, REG_LIBCALL, NULL_RTX))) | |
6084 | libcall_insn = XEXP (p, 0); | |
6085 | else if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
6086 | { | |
6087 | /* Keep libcall_insn for the last SET insn of | |
6088 | a no-conflict block to prevent changing the | |
6089 | destination. */ | |
6090 | if (!no_conflict) | |
6091 | libcall_insn = NULL_RTX; | |
6092 | else | |
6093 | no_conflict = -1; | |
6094 | } | |
6095 | else if (find_reg_note (insn, REG_NO_CONFLICT, NULL_RTX)) | |
6096 | no_conflict = 1; | |
fc3ffe83 | 6097 | } |
7afe21cc | 6098 | |
932ad4d9 | 6099 | cse_insn (insn, libcall_insn); |
7afe21cc | 6100 | |
932ad4d9 SB |
6101 | /* If we kept libcall_insn for a no-conflict bock, |
6102 | clear it here. */ | |
6103 | if (no_conflict == -1) | |
6104 | { | |
6105 | libcall_insn = NULL_RTX; | |
6106 | no_conflict = 0; | |
6107 | } | |
6108 | ||
6109 | /* If we haven't already found an insn where we added a LABEL_REF, | |
6110 | check this one. */ | |
6111 | if (NONJUMP_INSN_P (insn) && ! recorded_label_ref | |
6112 | && for_each_rtx (&PATTERN (insn), check_for_label_ref, | |
6113 | (void *) insn)) | |
6114 | recorded_label_ref = 1; | |
96fb470d SB |
6115 | |
6116 | #ifdef HAVE_cc0 | |
6117 | /* If the previous insn set CC0 and this insn no longer | |
6118 | references CC0, delete the previous insn. Here we use | |
6119 | fact that nothing expects CC0 to be valid over an insn, | |
6120 | which is true until the final pass. */ | |
6121 | { | |
6122 | rtx prev_insn, tem; | |
6123 | ||
6124 | prev_insn = PREV_INSN (insn); | |
6125 | if (prev_insn && NONJUMP_INSN_P (prev_insn) | |
6126 | && (tem = single_set (prev_insn)) != 0 | |
6127 | && SET_DEST (tem) == cc0_rtx | |
6128 | && ! reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
6129 | delete_insn (prev_insn); | |
6130 | } | |
6131 | ||
6132 | /* If this insn is not the last insn in the basic block, | |
6133 | it will be PREV_INSN(insn) in the next iteration. If | |
6134 | we recorded any CC0-related information for this insn, | |
6135 | remember it. */ | |
6136 | if (insn != BB_END (bb)) | |
6137 | { | |
6138 | prev_insn_cc0 = this_insn_cc0; | |
6139 | prev_insn_cc0_mode = this_insn_cc0_mode; | |
6140 | } | |
6141 | #endif | |
932ad4d9 SB |
6142 | } |
6143 | } | |
7afe21cc | 6144 | |
932ad4d9 SB |
6145 | /* Make sure that libcalls don't span multiple basic blocks. */ |
6146 | gcc_assert (libcall_insn == NULL_RTX); | |
7afe21cc | 6147 | |
a7582f7c SB |
6148 | /* With non-call exceptions, we are not always able to update |
6149 | the CFG properly inside cse_insn. So clean up possibly | |
6150 | redundant EH edges here. */ | |
6151 | if (flag_non_call_exceptions && have_eh_succ_edges (bb)) | |
6152 | purge_dead_edges (bb); | |
6153 | ||
932ad4d9 SB |
6154 | /* If we changed a conditional jump, we may have terminated |
6155 | the path we are following. Check that by verifying that | |
6156 | the edge we would take still exists. If the edge does | |
6157 | not exist anymore, purge the remainder of the path. | |
6158 | Note that this will cause us to return to the caller. */ | |
6159 | if (path_entry < path_size - 1) | |
6160 | { | |
6161 | basic_block next_bb = ebb_data->path[path_entry + 1].bb; | |
6162 | if (!find_edge (bb, next_bb)) | |
27511c65 SB |
6163 | { |
6164 | do | |
6165 | { | |
6166 | path_size--; | |
6167 | ||
6168 | /* If we truncate the path, we must also reset the | |
6169 | visited bit on the remaining blocks in the path, | |
6170 | or we will never visit them at all. */ | |
6171 | RESET_BIT (cse_visited_basic_blocks, | |
6172 | ebb_data->path[path_size].bb->index); | |
6173 | ebb_data->path[path_size].bb = NULL; | |
6174 | } | |
6175 | while (path_size - 1 != path_entry); | |
6176 | ebb_data->path_size = path_size; | |
6177 | } | |
7afe21cc | 6178 | } |
7afe21cc | 6179 | |
932ad4d9 SB |
6180 | /* If this is a conditional jump insn, record any known |
6181 | equivalences due to the condition being tested. */ | |
6182 | insn = BB_END (bb); | |
6183 | if (path_entry < path_size - 1 | |
6184 | && JUMP_P (insn) | |
6185 | && single_set (insn) | |
6186 | && any_condjump_p (insn)) | |
6187 | { | |
6188 | basic_block next_bb = ebb_data->path[path_entry + 1].bb; | |
6189 | bool taken = (next_bb == BRANCH_EDGE (bb)->dest); | |
6190 | record_jump_equiv (insn, taken); | |
6191 | } | |
96fb470d SB |
6192 | |
6193 | #ifdef HAVE_cc0 | |
6194 | /* Clear the CC0-tracking related insns, they can't provide | |
6195 | useful information across basic block boundaries. */ | |
6196 | prev_insn_cc0 = 0; | |
6197 | #endif | |
932ad4d9 | 6198 | } |
7afe21cc | 6199 | |
932ad4d9 | 6200 | gcc_assert (next_qty <= max_qty); |
7afe21cc | 6201 | |
932ad4d9 | 6202 | free (qty_table); |
7afe21cc RK |
6203 | } |
6204 | \f | |
7afe21cc RK |
6205 | /* Perform cse on the instructions of a function. |
6206 | F is the first instruction. | |
6207 | NREGS is one plus the highest pseudo-reg number used in the instruction. | |
6208 | ||
7afe21cc RK |
6209 | Returns 1 if jump_optimize should be redone due to simplifications |
6210 | in conditional jump instructions. */ | |
6211 | ||
6212 | int | |
932ad4d9 | 6213 | cse_main (rtx f ATTRIBUTE_UNUSED, int nregs) |
7afe21cc | 6214 | { |
932ad4d9 SB |
6215 | struct cse_basic_block_data ebb_data; |
6216 | basic_block bb; | |
27511c65 | 6217 | int *rc_order = XNEWVEC (int, last_basic_block); |
932ad4d9 | 6218 | int i, n_blocks; |
7afe21cc | 6219 | |
bc5e3b54 KH |
6220 | init_cse_reg_info (nregs); |
6221 | ||
932ad4d9 SB |
6222 | ebb_data.path = XNEWVEC (struct branch_path, |
6223 | PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH)); | |
9bf8cfbf | 6224 | |
7afe21cc | 6225 | cse_jumps_altered = 0; |
a5dfb4ee | 6226 | recorded_label_ref = 0; |
7afe21cc | 6227 | constant_pool_entries_cost = 0; |
dd0ba281 | 6228 | constant_pool_entries_regcost = 0; |
932ad4d9 SB |
6229 | ebb_data.path_size = 0; |
6230 | ebb_data.nsets = 0; | |
2f93eea8 | 6231 | rtl_hooks = cse_rtl_hooks; |
7afe21cc RK |
6232 | |
6233 | init_recog (); | |
9ae8ffe7 | 6234 | init_alias_analysis (); |
7afe21cc | 6235 | |
5ed6ace5 | 6236 | reg_eqv_table = XNEWVEC (struct reg_eqv_elem, nregs); |
7afe21cc | 6237 | |
932ad4d9 SB |
6238 | /* Set up the table of already visited basic blocks. */ |
6239 | cse_visited_basic_blocks = sbitmap_alloc (last_basic_block); | |
6240 | sbitmap_zero (cse_visited_basic_blocks); | |
7afe21cc | 6241 | |
932ad4d9 SB |
6242 | /* Compute the mapping from uids to cuids. |
6243 | CUIDs are numbers assigned to insns, like uids, except that | |
6244 | that cuids increase monotonically through the code. */ | |
164c8956 | 6245 | max_uid = get_max_uid (); |
5ed6ace5 | 6246 | uid_cuid = XCNEWVEC (int, max_uid + 1); |
932ad4d9 SB |
6247 | i = 0; |
6248 | FOR_EACH_BB (bb) | |
7afe21cc | 6249 | { |
932ad4d9 SB |
6250 | rtx insn; |
6251 | FOR_BB_INSNS (bb, insn) | |
6252 | INSN_CUID (insn) = ++i; | |
7afe21cc RK |
6253 | } |
6254 | ||
a7582f7c | 6255 | /* Loop over basic blocks in reverse completion order (RPO), |
932ad4d9 | 6256 | excluding the ENTRY and EXIT blocks. */ |
27511c65 | 6257 | n_blocks = pre_and_rev_post_order_compute (NULL, rc_order, false); |
932ad4d9 SB |
6258 | i = 0; |
6259 | while (i < n_blocks) | |
7afe21cc | 6260 | { |
a7582f7c | 6261 | /* Find the first block in the RPO queue that we have not yet |
932ad4d9 SB |
6262 | processed before. */ |
6263 | do | |
e9a25f70 | 6264 | { |
27511c65 | 6265 | bb = BASIC_BLOCK (rc_order[i++]); |
e9a25f70 | 6266 | } |
932ad4d9 SB |
6267 | while (TEST_BIT (cse_visited_basic_blocks, bb->index) |
6268 | && i < n_blocks); | |
7afe21cc | 6269 | |
932ad4d9 SB |
6270 | /* Find all paths starting with BB, and process them. */ |
6271 | while (cse_find_path (bb, &ebb_data, flag_cse_follow_jumps)) | |
7afe21cc | 6272 | { |
932ad4d9 SB |
6273 | /* Pre-scan the path. */ |
6274 | cse_prescan_path (&ebb_data); | |
7afe21cc | 6275 | |
932ad4d9 SB |
6276 | /* If this basic block has no sets, skip it. */ |
6277 | if (ebb_data.nsets == 0) | |
6278 | continue; | |
7afe21cc | 6279 | |
2e226e66 | 6280 | /* Get a reasonable estimate for the maximum number of qty's |
932ad4d9 SB |
6281 | needed for this path. For this, we take the number of sets |
6282 | and multiply that by MAX_RECOG_OPERANDS. */ | |
6283 | max_qty = ebb_data.nsets * MAX_RECOG_OPERANDS; | |
6284 | cse_basic_block_start = ebb_data.low_cuid; | |
6285 | cse_basic_block_end = ebb_data.high_cuid; | |
7afe21cc | 6286 | |
932ad4d9 SB |
6287 | /* Dump the path we're about to process. */ |
6288 | if (dump_file) | |
6289 | cse_dump_path (&ebb_data, ebb_data.nsets, dump_file); | |
6a5293dc | 6290 | |
932ad4d9 | 6291 | cse_extended_basic_block (&ebb_data); |
7afe21cc | 6292 | } |
7afe21cc RK |
6293 | } |
6294 | ||
932ad4d9 SB |
6295 | /* Clean up. */ |
6296 | end_alias_analysis (); | |
6297 | free (uid_cuid); | |
6298 | free (reg_eqv_table); | |
6299 | free (ebb_data.path); | |
6300 | sbitmap_free (cse_visited_basic_blocks); | |
27511c65 | 6301 | free (rc_order); |
932ad4d9 | 6302 | rtl_hooks = general_rtl_hooks; |
75c6bd46 | 6303 | |
932ad4d9 | 6304 | return cse_jumps_altered || recorded_label_ref; |
7afe21cc RK |
6305 | } |
6306 | \f | |
be8ac49a | 6307 | /* Called via for_each_rtx to see if an insn is using a LABEL_REF for which |
45c23566 | 6308 | there isn't a REG_LABEL note. Return one if so. DATA is the insn. */ |
be8ac49a RK |
6309 | |
6310 | static int | |
7080f735 | 6311 | check_for_label_ref (rtx *rtl, void *data) |
be8ac49a RK |
6312 | { |
6313 | rtx insn = (rtx) data; | |
6314 | ||
6315 | /* If this insn uses a LABEL_REF and there isn't a REG_LABEL note for it, | |
6316 | we must rerun jump since it needs to place the note. If this is a | |
6317 | LABEL_REF for a CODE_LABEL that isn't in the insn chain, don't do this | |
ec5c56db | 6318 | since no REG_LABEL will be added. */ |
be8ac49a | 6319 | return (GET_CODE (*rtl) == LABEL_REF |
45c23566 | 6320 | && ! LABEL_REF_NONLOCAL_P (*rtl) |
4838c5ee | 6321 | && LABEL_P (XEXP (*rtl, 0)) |
be8ac49a RK |
6322 | && INSN_UID (XEXP (*rtl, 0)) != 0 |
6323 | && ! find_reg_note (insn, REG_LABEL, XEXP (*rtl, 0))); | |
6324 | } | |
6325 | \f | |
7afe21cc RK |
6326 | /* Count the number of times registers are used (not set) in X. |
6327 | COUNTS is an array in which we accumulate the count, INCR is how much | |
b92ba6ff R |
6328 | we count each register usage. |
6329 | ||
6330 | Don't count a usage of DEST, which is the SET_DEST of a SET which | |
6331 | contains X in its SET_SRC. This is because such a SET does not | |
6332 | modify the liveness of DEST. | |
6333 | DEST is set to pc_rtx for a trapping insn, which means that we must count | |
6334 | uses of a SET_DEST regardless because the insn can't be deleted here. */ | |
7afe21cc RK |
6335 | |
6336 | static void | |
b92ba6ff | 6337 | count_reg_usage (rtx x, int *counts, rtx dest, int incr) |
7afe21cc | 6338 | { |
f1e7c95f | 6339 | enum rtx_code code; |
b17d5d7c | 6340 | rtx note; |
6f7d635c | 6341 | const char *fmt; |
7afe21cc RK |
6342 | int i, j; |
6343 | ||
f1e7c95f RK |
6344 | if (x == 0) |
6345 | return; | |
6346 | ||
6347 | switch (code = GET_CODE (x)) | |
7afe21cc RK |
6348 | { |
6349 | case REG: | |
b92ba6ff R |
6350 | if (x != dest) |
6351 | counts[REGNO (x)] += incr; | |
7afe21cc RK |
6352 | return; |
6353 | ||
6354 | case PC: | |
6355 | case CC0: | |
6356 | case CONST: | |
6357 | case CONST_INT: | |
6358 | case CONST_DOUBLE: | |
69ef87e2 | 6359 | case CONST_VECTOR: |
7afe21cc RK |
6360 | case SYMBOL_REF: |
6361 | case LABEL_REF: | |
02e39abc JL |
6362 | return; |
6363 | ||
278a83b2 | 6364 | case CLOBBER: |
02e39abc JL |
6365 | /* If we are clobbering a MEM, mark any registers inside the address |
6366 | as being used. */ | |
3c0cb5de | 6367 | if (MEM_P (XEXP (x, 0))) |
b92ba6ff | 6368 | count_reg_usage (XEXP (XEXP (x, 0), 0), counts, NULL_RTX, incr); |
7afe21cc RK |
6369 | return; |
6370 | ||
6371 | case SET: | |
6372 | /* Unless we are setting a REG, count everything in SET_DEST. */ | |
f8cfc6aa | 6373 | if (!REG_P (SET_DEST (x))) |
b92ba6ff R |
6374 | count_reg_usage (SET_DEST (x), counts, NULL_RTX, incr); |
6375 | count_reg_usage (SET_SRC (x), counts, | |
6376 | dest ? dest : SET_DEST (x), | |
6377 | incr); | |
7afe21cc RK |
6378 | return; |
6379 | ||
f1e7c95f | 6380 | case CALL_INSN: |
7afe21cc RK |
6381 | case INSN: |
6382 | case JUMP_INSN: | |
b92ba6ff R |
6383 | /* We expect dest to be NULL_RTX here. If the insn may trap, mark |
6384 | this fact by setting DEST to pc_rtx. */ | |
6385 | if (flag_non_call_exceptions && may_trap_p (PATTERN (x))) | |
6386 | dest = pc_rtx; | |
6387 | if (code == CALL_INSN) | |
6388 | count_reg_usage (CALL_INSN_FUNCTION_USAGE (x), counts, dest, incr); | |
6389 | count_reg_usage (PATTERN (x), counts, dest, incr); | |
7afe21cc RK |
6390 | |
6391 | /* Things used in a REG_EQUAL note aren't dead since loop may try to | |
6392 | use them. */ | |
6393 | ||
b17d5d7c ZD |
6394 | note = find_reg_equal_equiv_note (x); |
6395 | if (note) | |
839844be R |
6396 | { |
6397 | rtx eqv = XEXP (note, 0); | |
6398 | ||
6399 | if (GET_CODE (eqv) == EXPR_LIST) | |
6400 | /* This REG_EQUAL note describes the result of a function call. | |
6401 | Process all the arguments. */ | |
6402 | do | |
6403 | { | |
b92ba6ff | 6404 | count_reg_usage (XEXP (eqv, 0), counts, dest, incr); |
839844be R |
6405 | eqv = XEXP (eqv, 1); |
6406 | } | |
6407 | while (eqv && GET_CODE (eqv) == EXPR_LIST); | |
6408 | else | |
b92ba6ff | 6409 | count_reg_usage (eqv, counts, dest, incr); |
839844be | 6410 | } |
7afe21cc RK |
6411 | return; |
6412 | ||
ee960939 OH |
6413 | case EXPR_LIST: |
6414 | if (REG_NOTE_KIND (x) == REG_EQUAL | |
6415 | || (REG_NOTE_KIND (x) != REG_NONNEG && GET_CODE (XEXP (x,0)) == USE) | |
6416 | /* FUNCTION_USAGE expression lists may include (CLOBBER (mem /u)), | |
6417 | involving registers in the address. */ | |
6418 | || GET_CODE (XEXP (x, 0)) == CLOBBER) | |
b92ba6ff | 6419 | count_reg_usage (XEXP (x, 0), counts, NULL_RTX, incr); |
ee960939 | 6420 | |
b92ba6ff | 6421 | count_reg_usage (XEXP (x, 1), counts, NULL_RTX, incr); |
ee960939 OH |
6422 | return; |
6423 | ||
a6c14a64 | 6424 | case ASM_OPERANDS: |
b92ba6ff R |
6425 | /* If the asm is volatile, then this insn cannot be deleted, |
6426 | and so the inputs *must* be live. */ | |
6427 | if (MEM_VOLATILE_P (x)) | |
6428 | dest = NULL_RTX; | |
a6c14a64 RH |
6429 | /* Iterate over just the inputs, not the constraints as well. */ |
6430 | for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
b92ba6ff | 6431 | count_reg_usage (ASM_OPERANDS_INPUT (x, i), counts, dest, incr); |
a6c14a64 RH |
6432 | return; |
6433 | ||
7afe21cc | 6434 | case INSN_LIST: |
341c100f | 6435 | gcc_unreachable (); |
278a83b2 | 6436 | |
e9a25f70 JL |
6437 | default: |
6438 | break; | |
7afe21cc RK |
6439 | } |
6440 | ||
6441 | fmt = GET_RTX_FORMAT (code); | |
6442 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
6443 | { | |
6444 | if (fmt[i] == 'e') | |
b92ba6ff | 6445 | count_reg_usage (XEXP (x, i), counts, dest, incr); |
7afe21cc RK |
6446 | else if (fmt[i] == 'E') |
6447 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
b92ba6ff | 6448 | count_reg_usage (XVECEXP (x, i, j), counts, dest, incr); |
7afe21cc RK |
6449 | } |
6450 | } | |
6451 | \f | |
4793dca1 JH |
6452 | /* Return true if set is live. */ |
6453 | static bool | |
7080f735 AJ |
6454 | set_live_p (rtx set, rtx insn ATTRIBUTE_UNUSED, /* Only used with HAVE_cc0. */ |
6455 | int *counts) | |
4793dca1 JH |
6456 | { |
6457 | #ifdef HAVE_cc0 | |
6458 | rtx tem; | |
6459 | #endif | |
6460 | ||
6461 | if (set_noop_p (set)) | |
6462 | ; | |
6463 | ||
6464 | #ifdef HAVE_cc0 | |
6465 | else if (GET_CODE (SET_DEST (set)) == CC0 | |
6466 | && !side_effects_p (SET_SRC (set)) | |
6467 | && ((tem = next_nonnote_insn (insn)) == 0 | |
6468 | || !INSN_P (tem) | |
6469 | || !reg_referenced_p (cc0_rtx, PATTERN (tem)))) | |
6470 | return false; | |
6471 | #endif | |
f8cfc6aa | 6472 | else if (!REG_P (SET_DEST (set)) |
4793dca1 JH |
6473 | || REGNO (SET_DEST (set)) < FIRST_PSEUDO_REGISTER |
6474 | || counts[REGNO (SET_DEST (set))] != 0 | |
8fff4fc1 | 6475 | || side_effects_p (SET_SRC (set))) |
4793dca1 JH |
6476 | return true; |
6477 | return false; | |
6478 | } | |
6479 | ||
6480 | /* Return true if insn is live. */ | |
6481 | ||
6482 | static bool | |
7080f735 | 6483 | insn_live_p (rtx insn, int *counts) |
4793dca1 JH |
6484 | { |
6485 | int i; | |
a3745024 | 6486 | if (flag_non_call_exceptions && may_trap_p (PATTERN (insn))) |
a646f6cc AH |
6487 | return true; |
6488 | else if (GET_CODE (PATTERN (insn)) == SET) | |
0021de69 | 6489 | return set_live_p (PATTERN (insn), insn, counts); |
4793dca1 | 6490 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) |
0021de69 DB |
6491 | { |
6492 | for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) | |
6493 | { | |
6494 | rtx elt = XVECEXP (PATTERN (insn), 0, i); | |
4793dca1 | 6495 | |
0021de69 DB |
6496 | if (GET_CODE (elt) == SET) |
6497 | { | |
6498 | if (set_live_p (elt, insn, counts)) | |
6499 | return true; | |
6500 | } | |
6501 | else if (GET_CODE (elt) != CLOBBER && GET_CODE (elt) != USE) | |
6502 | return true; | |
6503 | } | |
6504 | return false; | |
6505 | } | |
4793dca1 JH |
6506 | else |
6507 | return true; | |
6508 | } | |
6509 | ||
6510 | /* Return true if libcall is dead as a whole. */ | |
6511 | ||
6512 | static bool | |
7080f735 | 6513 | dead_libcall_p (rtx insn, int *counts) |
4793dca1 | 6514 | { |
0c19a26f RS |
6515 | rtx note, set, new; |
6516 | ||
4793dca1 JH |
6517 | /* See if there's a REG_EQUAL note on this insn and try to |
6518 | replace the source with the REG_EQUAL expression. | |
6519 | ||
6520 | We assume that insns with REG_RETVALs can only be reg->reg | |
6521 | copies at this point. */ | |
6522 | note = find_reg_note (insn, REG_EQUAL, NULL_RTX); | |
0c19a26f RS |
6523 | if (!note) |
6524 | return false; | |
6525 | ||
6526 | set = single_set (insn); | |
6527 | if (!set) | |
6528 | return false; | |
4793dca1 | 6529 | |
0c19a26f RS |
6530 | new = simplify_rtx (XEXP (note, 0)); |
6531 | if (!new) | |
6532 | new = XEXP (note, 0); | |
4793dca1 | 6533 | |
0c19a26f | 6534 | /* While changing insn, we must update the counts accordingly. */ |
b92ba6ff | 6535 | count_reg_usage (insn, counts, NULL_RTX, -1); |
1e150f2c | 6536 | |
0c19a26f RS |
6537 | if (validate_change (insn, &SET_SRC (set), new, 0)) |
6538 | { | |
b92ba6ff | 6539 | count_reg_usage (insn, counts, NULL_RTX, 1); |
0c19a26f RS |
6540 | remove_note (insn, find_reg_note (insn, REG_RETVAL, NULL_RTX)); |
6541 | remove_note (insn, note); | |
6542 | return true; | |
6543 | } | |
6544 | ||
6545 | if (CONSTANT_P (new)) | |
6546 | { | |
6547 | new = force_const_mem (GET_MODE (SET_DEST (set)), new); | |
6548 | if (new && validate_change (insn, &SET_SRC (set), new, 0)) | |
4793dca1 | 6549 | { |
b92ba6ff | 6550 | count_reg_usage (insn, counts, NULL_RTX, 1); |
4793dca1 | 6551 | remove_note (insn, find_reg_note (insn, REG_RETVAL, NULL_RTX)); |
1e150f2c | 6552 | remove_note (insn, note); |
4793dca1 JH |
6553 | return true; |
6554 | } | |
6555 | } | |
7080f735 | 6556 | |
b92ba6ff | 6557 | count_reg_usage (insn, counts, NULL_RTX, 1); |
4793dca1 JH |
6558 | return false; |
6559 | } | |
6560 | ||
7afe21cc RK |
6561 | /* Scan all the insns and delete any that are dead; i.e., they store a register |
6562 | that is never used or they copy a register to itself. | |
6563 | ||
c6a26dc4 JL |
6564 | This is used to remove insns made obviously dead by cse, loop or other |
6565 | optimizations. It improves the heuristics in loop since it won't try to | |
6566 | move dead invariants out of loops or make givs for dead quantities. The | |
6567 | remaining passes of the compilation are also sped up. */ | |
7afe21cc | 6568 | |
3dec4024 | 6569 | int |
7080f735 | 6570 | delete_trivially_dead_insns (rtx insns, int nreg) |
7afe21cc | 6571 | { |
4da896b2 | 6572 | int *counts; |
77fa0940 | 6573 | rtx insn, prev; |
614bb5d4 | 6574 | int in_libcall = 0, dead_libcall = 0; |
65e9fa10 | 6575 | int ndead = 0; |
7afe21cc | 6576 | |
3dec4024 | 6577 | timevar_push (TV_DELETE_TRIVIALLY_DEAD); |
7afe21cc | 6578 | /* First count the number of times each register is used. */ |
5ed6ace5 | 6579 | counts = XCNEWVEC (int, nreg); |
03ce14db KH |
6580 | for (insn = insns; insn; insn = NEXT_INSN (insn)) |
6581 | if (INSN_P (insn)) | |
b92ba6ff | 6582 | count_reg_usage (insn, counts, NULL_RTX, 1); |
7afe21cc | 6583 | |
65e9fa10 KH |
6584 | /* Go from the last insn to the first and delete insns that only set unused |
6585 | registers or copy a register to itself. As we delete an insn, remove | |
6586 | usage counts for registers it uses. | |
0cedb36c | 6587 | |
65e9fa10 KH |
6588 | The first jump optimization pass may leave a real insn as the last |
6589 | insn in the function. We must not skip that insn or we may end | |
6590 | up deleting code that is not really dead. */ | |
03ce14db | 6591 | for (insn = get_last_insn (); insn; insn = prev) |
65e9fa10 KH |
6592 | { |
6593 | int live_insn = 0; | |
7afe21cc | 6594 | |
03ce14db KH |
6595 | prev = PREV_INSN (insn); |
6596 | if (!INSN_P (insn)) | |
6597 | continue; | |
7afe21cc | 6598 | |
65e9fa10 KH |
6599 | /* Don't delete any insns that are part of a libcall block unless |
6600 | we can delete the whole libcall block. | |
6601 | ||
6602 | Flow or loop might get confused if we did that. Remember | |
6603 | that we are scanning backwards. */ | |
6604 | if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
6605 | { | |
6606 | in_libcall = 1; | |
6607 | live_insn = 1; | |
6608 | dead_libcall = dead_libcall_p (insn, counts); | |
6609 | } | |
6610 | else if (in_libcall) | |
6611 | live_insn = ! dead_libcall; | |
6612 | else | |
6613 | live_insn = insn_live_p (insn, counts); | |
7afe21cc | 6614 | |
65e9fa10 KH |
6615 | /* If this is a dead insn, delete it and show registers in it aren't |
6616 | being used. */ | |
7afe21cc | 6617 | |
65e9fa10 KH |
6618 | if (! live_insn) |
6619 | { | |
b92ba6ff | 6620 | count_reg_usage (insn, counts, NULL_RTX, -1); |
65e9fa10 KH |
6621 | delete_insn_and_edges (insn); |
6622 | ndead++; | |
6623 | } | |
e4890d45 | 6624 | |
2b5936fd | 6625 | if (in_libcall && find_reg_note (insn, REG_LIBCALL, NULL_RTX)) |
65e9fa10 KH |
6626 | { |
6627 | in_libcall = 0; | |
6628 | dead_libcall = 0; | |
614bb5d4 | 6629 | } |
68252e27 | 6630 | } |
4da896b2 | 6631 | |
c263766c | 6632 | if (dump_file && ndead) |
65e9fa10 KH |
6633 | fprintf (dump_file, "Deleted %i trivially dead insns\n", |
6634 | ndead); | |
4da896b2 MM |
6635 | /* Clean up. */ |
6636 | free (counts); | |
3dec4024 JH |
6637 | timevar_pop (TV_DELETE_TRIVIALLY_DEAD); |
6638 | return ndead; | |
7afe21cc | 6639 | } |
e129d93a ILT |
6640 | |
6641 | /* This function is called via for_each_rtx. The argument, NEWREG, is | |
6642 | a condition code register with the desired mode. If we are looking | |
6643 | at the same register in a different mode, replace it with | |
6644 | NEWREG. */ | |
6645 | ||
6646 | static int | |
6647 | cse_change_cc_mode (rtx *loc, void *data) | |
6648 | { | |
fc188d37 | 6649 | struct change_cc_mode_args* args = (struct change_cc_mode_args*)data; |
e129d93a ILT |
6650 | |
6651 | if (*loc | |
f8cfc6aa | 6652 | && REG_P (*loc) |
fc188d37 AK |
6653 | && REGNO (*loc) == REGNO (args->newreg) |
6654 | && GET_MODE (*loc) != GET_MODE (args->newreg)) | |
e129d93a | 6655 | { |
fc188d37 AK |
6656 | validate_change (args->insn, loc, args->newreg, 1); |
6657 | ||
e129d93a ILT |
6658 | return -1; |
6659 | } | |
6660 | return 0; | |
6661 | } | |
6662 | ||
fc188d37 AK |
6663 | /* Change the mode of any reference to the register REGNO (NEWREG) to |
6664 | GET_MODE (NEWREG) in INSN. */ | |
6665 | ||
6666 | static void | |
6667 | cse_change_cc_mode_insn (rtx insn, rtx newreg) | |
6668 | { | |
6669 | struct change_cc_mode_args args; | |
6670 | int success; | |
6671 | ||
6672 | if (!INSN_P (insn)) | |
6673 | return; | |
6674 | ||
6675 | args.insn = insn; | |
6676 | args.newreg = newreg; | |
6677 | ||
6678 | for_each_rtx (&PATTERN (insn), cse_change_cc_mode, &args); | |
6679 | for_each_rtx (®_NOTES (insn), cse_change_cc_mode, &args); | |
6680 | ||
6681 | /* If the following assertion was triggered, there is most probably | |
6682 | something wrong with the cc_modes_compatible back end function. | |
6683 | CC modes only can be considered compatible if the insn - with the mode | |
6684 | replaced by any of the compatible modes - can still be recognized. */ | |
6685 | success = apply_change_group (); | |
6686 | gcc_assert (success); | |
6687 | } | |
6688 | ||
e129d93a ILT |
6689 | /* Change the mode of any reference to the register REGNO (NEWREG) to |
6690 | GET_MODE (NEWREG), starting at START. Stop before END. Stop at | |
2e802a6f | 6691 | any instruction which modifies NEWREG. */ |
e129d93a ILT |
6692 | |
6693 | static void | |
6694 | cse_change_cc_mode_insns (rtx start, rtx end, rtx newreg) | |
6695 | { | |
6696 | rtx insn; | |
6697 | ||
6698 | for (insn = start; insn != end; insn = NEXT_INSN (insn)) | |
6699 | { | |
6700 | if (! INSN_P (insn)) | |
6701 | continue; | |
6702 | ||
2e802a6f | 6703 | if (reg_set_p (newreg, insn)) |
e129d93a ILT |
6704 | return; |
6705 | ||
fc188d37 | 6706 | cse_change_cc_mode_insn (insn, newreg); |
e129d93a ILT |
6707 | } |
6708 | } | |
6709 | ||
6710 | /* BB is a basic block which finishes with CC_REG as a condition code | |
6711 | register which is set to CC_SRC. Look through the successors of BB | |
6712 | to find blocks which have a single predecessor (i.e., this one), | |
6713 | and look through those blocks for an assignment to CC_REG which is | |
6714 | equivalent to CC_SRC. CAN_CHANGE_MODE indicates whether we are | |
6715 | permitted to change the mode of CC_SRC to a compatible mode. This | |
6716 | returns VOIDmode if no equivalent assignments were found. | |
6717 | Otherwise it returns the mode which CC_SRC should wind up with. | |
6718 | ||
6719 | The main complexity in this function is handling the mode issues. | |
6720 | We may have more than one duplicate which we can eliminate, and we | |
6721 | try to find a mode which will work for multiple duplicates. */ | |
6722 | ||
6723 | static enum machine_mode | |
6724 | cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode) | |
6725 | { | |
6726 | bool found_equiv; | |
6727 | enum machine_mode mode; | |
6728 | unsigned int insn_count; | |
6729 | edge e; | |
6730 | rtx insns[2]; | |
6731 | enum machine_mode modes[2]; | |
6732 | rtx last_insns[2]; | |
6733 | unsigned int i; | |
6734 | rtx newreg; | |
628f6a4e | 6735 | edge_iterator ei; |
e129d93a ILT |
6736 | |
6737 | /* We expect to have two successors. Look at both before picking | |
6738 | the final mode for the comparison. If we have more successors | |
6739 | (i.e., some sort of table jump, although that seems unlikely), | |
6740 | then we require all beyond the first two to use the same | |
6741 | mode. */ | |
6742 | ||
6743 | found_equiv = false; | |
6744 | mode = GET_MODE (cc_src); | |
6745 | insn_count = 0; | |
628f6a4e | 6746 | FOR_EACH_EDGE (e, ei, bb->succs) |
e129d93a ILT |
6747 | { |
6748 | rtx insn; | |
6749 | rtx end; | |
6750 | ||
6751 | if (e->flags & EDGE_COMPLEX) | |
6752 | continue; | |
6753 | ||
628f6a4e | 6754 | if (EDGE_COUNT (e->dest->preds) != 1 |
e129d93a ILT |
6755 | || e->dest == EXIT_BLOCK_PTR) |
6756 | continue; | |
6757 | ||
6758 | end = NEXT_INSN (BB_END (e->dest)); | |
6759 | for (insn = BB_HEAD (e->dest); insn != end; insn = NEXT_INSN (insn)) | |
6760 | { | |
6761 | rtx set; | |
6762 | ||
6763 | if (! INSN_P (insn)) | |
6764 | continue; | |
6765 | ||
6766 | /* If CC_SRC is modified, we have to stop looking for | |
6767 | something which uses it. */ | |
6768 | if (modified_in_p (cc_src, insn)) | |
6769 | break; | |
6770 | ||
6771 | /* Check whether INSN sets CC_REG to CC_SRC. */ | |
6772 | set = single_set (insn); | |
6773 | if (set | |
f8cfc6aa | 6774 | && REG_P (SET_DEST (set)) |
e129d93a ILT |
6775 | && REGNO (SET_DEST (set)) == REGNO (cc_reg)) |
6776 | { | |
6777 | bool found; | |
6778 | enum machine_mode set_mode; | |
6779 | enum machine_mode comp_mode; | |
6780 | ||
6781 | found = false; | |
6782 | set_mode = GET_MODE (SET_SRC (set)); | |
6783 | comp_mode = set_mode; | |
6784 | if (rtx_equal_p (cc_src, SET_SRC (set))) | |
6785 | found = true; | |
6786 | else if (GET_CODE (cc_src) == COMPARE | |
6787 | && GET_CODE (SET_SRC (set)) == COMPARE | |
1f44254c | 6788 | && mode != set_mode |
e129d93a ILT |
6789 | && rtx_equal_p (XEXP (cc_src, 0), |
6790 | XEXP (SET_SRC (set), 0)) | |
6791 | && rtx_equal_p (XEXP (cc_src, 1), | |
6792 | XEXP (SET_SRC (set), 1))) | |
6793 | ||
6794 | { | |
5fd9b178 | 6795 | comp_mode = targetm.cc_modes_compatible (mode, set_mode); |
e129d93a ILT |
6796 | if (comp_mode != VOIDmode |
6797 | && (can_change_mode || comp_mode == mode)) | |
6798 | found = true; | |
6799 | } | |
6800 | ||
6801 | if (found) | |
6802 | { | |
6803 | found_equiv = true; | |
1f44254c | 6804 | if (insn_count < ARRAY_SIZE (insns)) |
e129d93a ILT |
6805 | { |
6806 | insns[insn_count] = insn; | |
6807 | modes[insn_count] = set_mode; | |
6808 | last_insns[insn_count] = end; | |
6809 | ++insn_count; | |
6810 | ||
1f44254c ILT |
6811 | if (mode != comp_mode) |
6812 | { | |
341c100f | 6813 | gcc_assert (can_change_mode); |
1f44254c | 6814 | mode = comp_mode; |
fc188d37 AK |
6815 | |
6816 | /* The modified insn will be re-recognized later. */ | |
1f44254c ILT |
6817 | PUT_MODE (cc_src, mode); |
6818 | } | |
e129d93a ILT |
6819 | } |
6820 | else | |
6821 | { | |
6822 | if (set_mode != mode) | |
1f44254c ILT |
6823 | { |
6824 | /* We found a matching expression in the | |
6825 | wrong mode, but we don't have room to | |
6826 | store it in the array. Punt. This case | |
6827 | should be rare. */ | |
6828 | break; | |
6829 | } | |
e129d93a ILT |
6830 | /* INSN sets CC_REG to a value equal to CC_SRC |
6831 | with the right mode. We can simply delete | |
6832 | it. */ | |
6833 | delete_insn (insn); | |
6834 | } | |
6835 | ||
6836 | /* We found an instruction to delete. Keep looking, | |
6837 | in the hopes of finding a three-way jump. */ | |
6838 | continue; | |
6839 | } | |
6840 | ||
6841 | /* We found an instruction which sets the condition | |
6842 | code, so don't look any farther. */ | |
6843 | break; | |
6844 | } | |
6845 | ||
6846 | /* If INSN sets CC_REG in some other way, don't look any | |
6847 | farther. */ | |
6848 | if (reg_set_p (cc_reg, insn)) | |
6849 | break; | |
6850 | } | |
6851 | ||
6852 | /* If we fell off the bottom of the block, we can keep looking | |
6853 | through successors. We pass CAN_CHANGE_MODE as false because | |
6854 | we aren't prepared to handle compatibility between the | |
6855 | further blocks and this block. */ | |
6856 | if (insn == end) | |
6857 | { | |
1f44254c ILT |
6858 | enum machine_mode submode; |
6859 | ||
6860 | submode = cse_cc_succs (e->dest, cc_reg, cc_src, false); | |
6861 | if (submode != VOIDmode) | |
6862 | { | |
341c100f | 6863 | gcc_assert (submode == mode); |
1f44254c ILT |
6864 | found_equiv = true; |
6865 | can_change_mode = false; | |
6866 | } | |
e129d93a ILT |
6867 | } |
6868 | } | |
6869 | ||
6870 | if (! found_equiv) | |
6871 | return VOIDmode; | |
6872 | ||
6873 | /* Now INSN_COUNT is the number of instructions we found which set | |
6874 | CC_REG to a value equivalent to CC_SRC. The instructions are in | |
6875 | INSNS. The modes used by those instructions are in MODES. */ | |
6876 | ||
6877 | newreg = NULL_RTX; | |
6878 | for (i = 0; i < insn_count; ++i) | |
6879 | { | |
6880 | if (modes[i] != mode) | |
6881 | { | |
6882 | /* We need to change the mode of CC_REG in INSNS[i] and | |
6883 | subsequent instructions. */ | |
6884 | if (! newreg) | |
6885 | { | |
6886 | if (GET_MODE (cc_reg) == mode) | |
6887 | newreg = cc_reg; | |
6888 | else | |
6889 | newreg = gen_rtx_REG (mode, REGNO (cc_reg)); | |
6890 | } | |
6891 | cse_change_cc_mode_insns (NEXT_INSN (insns[i]), last_insns[i], | |
6892 | newreg); | |
6893 | } | |
6894 | ||
6895 | delete_insn (insns[i]); | |
6896 | } | |
6897 | ||
6898 | return mode; | |
6899 | } | |
6900 | ||
6901 | /* If we have a fixed condition code register (or two), walk through | |
6902 | the instructions and try to eliminate duplicate assignments. */ | |
6903 | ||
cab2264d | 6904 | static void |
e129d93a ILT |
6905 | cse_condition_code_reg (void) |
6906 | { | |
6907 | unsigned int cc_regno_1; | |
6908 | unsigned int cc_regno_2; | |
6909 | rtx cc_reg_1; | |
6910 | rtx cc_reg_2; | |
6911 | basic_block bb; | |
6912 | ||
5fd9b178 | 6913 | if (! targetm.fixed_condition_code_regs (&cc_regno_1, &cc_regno_2)) |
e129d93a ILT |
6914 | return; |
6915 | ||
6916 | cc_reg_1 = gen_rtx_REG (CCmode, cc_regno_1); | |
6917 | if (cc_regno_2 != INVALID_REGNUM) | |
6918 | cc_reg_2 = gen_rtx_REG (CCmode, cc_regno_2); | |
6919 | else | |
6920 | cc_reg_2 = NULL_RTX; | |
6921 | ||
6922 | FOR_EACH_BB (bb) | |
6923 | { | |
6924 | rtx last_insn; | |
6925 | rtx cc_reg; | |
6926 | rtx insn; | |
6927 | rtx cc_src_insn; | |
6928 | rtx cc_src; | |
6929 | enum machine_mode mode; | |
1f44254c | 6930 | enum machine_mode orig_mode; |
e129d93a ILT |
6931 | |
6932 | /* Look for blocks which end with a conditional jump based on a | |
6933 | condition code register. Then look for the instruction which | |
6934 | sets the condition code register. Then look through the | |
6935 | successor blocks for instructions which set the condition | |
6936 | code register to the same value. There are other possible | |
6937 | uses of the condition code register, but these are by far the | |
6938 | most common and the ones which we are most likely to be able | |
6939 | to optimize. */ | |
6940 | ||
6941 | last_insn = BB_END (bb); | |
4b4bf941 | 6942 | if (!JUMP_P (last_insn)) |
e129d93a ILT |
6943 | continue; |
6944 | ||
6945 | if (reg_referenced_p (cc_reg_1, PATTERN (last_insn))) | |
6946 | cc_reg = cc_reg_1; | |
6947 | else if (cc_reg_2 && reg_referenced_p (cc_reg_2, PATTERN (last_insn))) | |
6948 | cc_reg = cc_reg_2; | |
6949 | else | |
6950 | continue; | |
6951 | ||
6952 | cc_src_insn = NULL_RTX; | |
6953 | cc_src = NULL_RTX; | |
6954 | for (insn = PREV_INSN (last_insn); | |
6955 | insn && insn != PREV_INSN (BB_HEAD (bb)); | |
6956 | insn = PREV_INSN (insn)) | |
6957 | { | |
6958 | rtx set; | |
6959 | ||
6960 | if (! INSN_P (insn)) | |
6961 | continue; | |
6962 | set = single_set (insn); | |
6963 | if (set | |
f8cfc6aa | 6964 | && REG_P (SET_DEST (set)) |
e129d93a ILT |
6965 | && REGNO (SET_DEST (set)) == REGNO (cc_reg)) |
6966 | { | |
6967 | cc_src_insn = insn; | |
6968 | cc_src = SET_SRC (set); | |
6969 | break; | |
6970 | } | |
6971 | else if (reg_set_p (cc_reg, insn)) | |
6972 | break; | |
6973 | } | |
6974 | ||
6975 | if (! cc_src_insn) | |
6976 | continue; | |
6977 | ||
6978 | if (modified_between_p (cc_src, cc_src_insn, NEXT_INSN (last_insn))) | |
6979 | continue; | |
6980 | ||
6981 | /* Now CC_REG is a condition code register used for a | |
6982 | conditional jump at the end of the block, and CC_SRC, in | |
6983 | CC_SRC_INSN, is the value to which that condition code | |
6984 | register is set, and CC_SRC is still meaningful at the end of | |
6985 | the basic block. */ | |
6986 | ||
1f44254c | 6987 | orig_mode = GET_MODE (cc_src); |
e129d93a | 6988 | mode = cse_cc_succs (bb, cc_reg, cc_src, true); |
1f44254c | 6989 | if (mode != VOIDmode) |
e129d93a | 6990 | { |
341c100f | 6991 | gcc_assert (mode == GET_MODE (cc_src)); |
1f44254c | 6992 | if (mode != orig_mode) |
2e802a6f KH |
6993 | { |
6994 | rtx newreg = gen_rtx_REG (mode, REGNO (cc_reg)); | |
6995 | ||
fc188d37 | 6996 | cse_change_cc_mode_insn (cc_src_insn, newreg); |
2e802a6f KH |
6997 | |
6998 | /* Do the same in the following insns that use the | |
6999 | current value of CC_REG within BB. */ | |
7000 | cse_change_cc_mode_insns (NEXT_INSN (cc_src_insn), | |
7001 | NEXT_INSN (last_insn), | |
7002 | newreg); | |
7003 | } | |
e129d93a ILT |
7004 | } |
7005 | } | |
7006 | } | |
ef330312 PB |
7007 | \f |
7008 | ||
7009 | /* Perform common subexpression elimination. Nonzero value from | |
7010 | `cse_main' means that jumps were simplified and some code may now | |
7011 | be unreachable, so do jump optimization again. */ | |
7012 | static bool | |
7013 | gate_handle_cse (void) | |
7014 | { | |
7015 | return optimize > 0; | |
7016 | } | |
7017 | ||
c2924966 | 7018 | static unsigned int |
ef330312 PB |
7019 | rest_of_handle_cse (void) |
7020 | { | |
7021 | int tem; | |
ef330312 | 7022 | if (dump_file) |
5b4fdb20 | 7023 | dump_flow_info (dump_file, dump_flags); |
ef330312 PB |
7024 | |
7025 | reg_scan (get_insns (), max_reg_num ()); | |
7026 | ||
10d22567 | 7027 | tem = cse_main (get_insns (), max_reg_num ()); |
ef330312 PB |
7028 | |
7029 | /* If we are not running more CSE passes, then we are no longer | |
7030 | expecting CSE to be run. But always rerun it in a cheap mode. */ | |
7031 | cse_not_expected = !flag_rerun_cse_after_loop && !flag_gcse; | |
7032 | ||
7033 | if (tem) | |
932ad4d9 | 7034 | rebuild_jump_labels (get_insns ()); |
ef330312 PB |
7035 | |
7036 | if (tem || optimize > 1) | |
59994160 | 7037 | cleanup_cfg (CLEANUP_EXPENSIVE); |
932ad4d9 | 7038 | |
c2924966 | 7039 | return 0; |
ef330312 PB |
7040 | } |
7041 | ||
7042 | struct tree_opt_pass pass_cse = | |
7043 | { | |
7044 | "cse1", /* name */ | |
7045 | gate_handle_cse, /* gate */ | |
7046 | rest_of_handle_cse, /* execute */ | |
7047 | NULL, /* sub */ | |
7048 | NULL, /* next */ | |
7049 | 0, /* static_pass_number */ | |
7050 | TV_CSE, /* tv_id */ | |
7051 | 0, /* properties_required */ | |
7052 | 0, /* properties_provided */ | |
7053 | 0, /* properties_destroyed */ | |
7054 | 0, /* todo_flags_start */ | |
7055 | TODO_dump_func | | |
932ad4d9 SB |
7056 | TODO_ggc_collect | |
7057 | TODO_verify_flow, /* todo_flags_finish */ | |
ef330312 PB |
7058 | 's' /* letter */ |
7059 | }; | |
7060 | ||
7061 | ||
7062 | static bool | |
7063 | gate_handle_cse2 (void) | |
7064 | { | |
7065 | return optimize > 0 && flag_rerun_cse_after_loop; | |
7066 | } | |
7067 | ||
7068 | /* Run second CSE pass after loop optimizations. */ | |
c2924966 | 7069 | static unsigned int |
ef330312 PB |
7070 | rest_of_handle_cse2 (void) |
7071 | { | |
7072 | int tem; | |
7073 | ||
7074 | if (dump_file) | |
5b4fdb20 | 7075 | dump_flow_info (dump_file, dump_flags); |
ef330312 | 7076 | |
10d22567 | 7077 | tem = cse_main (get_insns (), max_reg_num ()); |
ef330312 PB |
7078 | |
7079 | /* Run a pass to eliminate duplicated assignments to condition code | |
7080 | registers. We have to run this after bypass_jumps, because it | |
7081 | makes it harder for that pass to determine whether a jump can be | |
7082 | bypassed safely. */ | |
7083 | cse_condition_code_reg (); | |
7084 | ||
ef330312 PB |
7085 | delete_trivially_dead_insns (get_insns (), max_reg_num ()); |
7086 | ||
7087 | if (tem) | |
7088 | { | |
7089 | timevar_push (TV_JUMP); | |
7090 | rebuild_jump_labels (get_insns ()); | |
7091 | delete_dead_jumptables (); | |
7092 | cleanup_cfg (CLEANUP_EXPENSIVE); | |
7093 | timevar_pop (TV_JUMP); | |
7094 | } | |
7095 | reg_scan (get_insns (), max_reg_num ()); | |
7096 | cse_not_expected = 1; | |
c2924966 | 7097 | return 0; |
ef330312 PB |
7098 | } |
7099 | ||
7100 | ||
7101 | struct tree_opt_pass pass_cse2 = | |
7102 | { | |
7103 | "cse2", /* name */ | |
7104 | gate_handle_cse2, /* gate */ | |
7105 | rest_of_handle_cse2, /* execute */ | |
7106 | NULL, /* sub */ | |
7107 | NULL, /* next */ | |
7108 | 0, /* static_pass_number */ | |
7109 | TV_CSE2, /* tv_id */ | |
7110 | 0, /* properties_required */ | |
7111 | 0, /* properties_provided */ | |
7112 | 0, /* properties_destroyed */ | |
7113 | 0, /* todo_flags_start */ | |
7114 | TODO_dump_func | | |
932ad4d9 SB |
7115 | TODO_ggc_collect | |
7116 | TODO_verify_flow, /* todo_flags_finish */ | |
ef330312 PB |
7117 | 't' /* letter */ |
7118 | }; | |
7119 |