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7afe21cc | 1 | /* Common subexpression elimination for GNU compiler. |
cbe34bb5 | 2 | Copyright (C) 1987-2017 Free Software Foundation, Inc. |
7afe21cc | 3 | |
1322177d | 4 | This file is part of GCC. |
7afe21cc | 5 | |
1322177d LB |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 8 | Software Foundation; either version 3, or (at your option) any later |
1322177d | 9 | version. |
7afe21cc | 10 | |
1322177d LB |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
7afe21cc RK |
15 | |
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
7afe21cc | 19 | |
7afe21cc | 20 | #include "config.h" |
670ee920 | 21 | #include "system.h" |
4977bab6 | 22 | #include "coretypes.h" |
c7131fb2 | 23 | #include "backend.h" |
957060b5 | 24 | #include "target.h" |
7afe21cc | 25 | #include "rtl.h" |
957060b5 AM |
26 | #include "tree.h" |
27 | #include "cfghooks.h" | |
c7131fb2 | 28 | #include "df.h" |
4d0cdd0c | 29 | #include "memmodel.h" |
6baf1cc8 | 30 | #include "tm_p.h" |
957060b5 | 31 | #include "insn-config.h" |
7932a3db | 32 | #include "regs.h" |
957060b5 AM |
33 | #include "emit-rtl.h" |
34 | #include "recog.h" | |
60393bbc AM |
35 | #include "cfgrtl.h" |
36 | #include "cfganal.h" | |
37 | #include "cfgcleanup.h" | |
36566b39 | 38 | #include "alias.h" |
50b2596f | 39 | #include "toplev.h" |
9bf8cfbf | 40 | #include "params.h" |
2f93eea8 | 41 | #include "rtlhooks-def.h" |
ef330312 | 42 | #include "tree-pass.h" |
6fb5fa3c | 43 | #include "dbgcnt.h" |
e89b312e | 44 | #include "rtl-iter.h" |
7afe21cc RK |
45 | |
46 | /* The basic idea of common subexpression elimination is to go | |
47 | through the code, keeping a record of expressions that would | |
48 | have the same value at the current scan point, and replacing | |
49 | expressions encountered with the cheapest equivalent expression. | |
50 | ||
51 | It is too complicated to keep track of the different possibilities | |
e48a7fbe JL |
52 | when control paths merge in this code; so, at each label, we forget all |
53 | that is known and start fresh. This can be described as processing each | |
54 | extended basic block separately. We have a separate pass to perform | |
55 | global CSE. | |
56 | ||
57 | Note CSE can turn a conditional or computed jump into a nop or | |
58 | an unconditional jump. When this occurs we arrange to run the jump | |
59 | optimizer after CSE to delete the unreachable code. | |
7afe21cc RK |
60 | |
61 | We use two data structures to record the equivalent expressions: | |
1bb98cec DM |
62 | a hash table for most expressions, and a vector of "quantity |
63 | numbers" to record equivalent (pseudo) registers. | |
7afe21cc RK |
64 | |
65 | The use of the special data structure for registers is desirable | |
66 | because it is faster. It is possible because registers references | |
67 | contain a fairly small number, the register number, taken from | |
68 | a contiguously allocated series, and two register references are | |
69 | identical if they have the same number. General expressions | |
70 | do not have any such thing, so the only way to retrieve the | |
71 | information recorded on an expression other than a register | |
72 | is to keep it in a hash table. | |
73 | ||
74 | Registers and "quantity numbers": | |
278a83b2 | 75 | |
7afe21cc RK |
76 | At the start of each basic block, all of the (hardware and pseudo) |
77 | registers used in the function are given distinct quantity | |
78 | numbers to indicate their contents. During scan, when the code | |
79 | copies one register into another, we copy the quantity number. | |
80 | When a register is loaded in any other way, we allocate a new | |
81 | quantity number to describe the value generated by this operation. | |
459281be | 82 | `REG_QTY (N)' records what quantity register N is currently thought |
7afe21cc RK |
83 | of as containing. |
84 | ||
08a69267 | 85 | All real quantity numbers are greater than or equal to zero. |
459281be | 86 | If register N has not been assigned a quantity, `REG_QTY (N)' will |
08a69267 | 87 | equal -N - 1, which is always negative. |
7afe21cc | 88 | |
08a69267 RS |
89 | Quantity numbers below zero do not exist and none of the `qty_table' |
90 | entries should be referenced with a negative index. | |
7afe21cc RK |
91 | |
92 | We also maintain a bidirectional chain of registers for each | |
1bb98cec DM |
93 | quantity number. The `qty_table` members `first_reg' and `last_reg', |
94 | and `reg_eqv_table' members `next' and `prev' hold these chains. | |
7afe21cc RK |
95 | |
96 | The first register in a chain is the one whose lifespan is least local. | |
97 | Among equals, it is the one that was seen first. | |
98 | We replace any equivalent register with that one. | |
99 | ||
100 | If two registers have the same quantity number, it must be true that | |
1bb98cec | 101 | REG expressions with qty_table `mode' must be in the hash table for both |
7afe21cc RK |
102 | registers and must be in the same class. |
103 | ||
104 | The converse is not true. Since hard registers may be referenced in | |
105 | any mode, two REG expressions might be equivalent in the hash table | |
106 | but not have the same quantity number if the quantity number of one | |
107 | of the registers is not the same mode as those expressions. | |
278a83b2 | 108 | |
7afe21cc RK |
109 | Constants and quantity numbers |
110 | ||
111 | When a quantity has a known constant value, that value is stored | |
1bb98cec | 112 | in the appropriate qty_table `const_rtx'. This is in addition to |
7afe21cc RK |
113 | putting the constant in the hash table as is usual for non-regs. |
114 | ||
d45cf215 | 115 | Whether a reg or a constant is preferred is determined by the configuration |
7afe21cc RK |
116 | macro CONST_COSTS and will often depend on the constant value. In any |
117 | event, expressions containing constants can be simplified, by fold_rtx. | |
118 | ||
119 | When a quantity has a known nearly constant value (such as an address | |
1bb98cec DM |
120 | of a stack slot), that value is stored in the appropriate qty_table |
121 | `const_rtx'. | |
7afe21cc RK |
122 | |
123 | Integer constants don't have a machine mode. However, cse | |
124 | determines the intended machine mode from the destination | |
125 | of the instruction that moves the constant. The machine mode | |
126 | is recorded in the hash table along with the actual RTL | |
127 | constant expression so that different modes are kept separate. | |
128 | ||
129 | Other expressions: | |
130 | ||
131 | To record known equivalences among expressions in general | |
132 | we use a hash table called `table'. It has a fixed number of buckets | |
133 | that contain chains of `struct table_elt' elements for expressions. | |
134 | These chains connect the elements whose expressions have the same | |
135 | hash codes. | |
136 | ||
137 | Other chains through the same elements connect the elements which | |
138 | currently have equivalent values. | |
139 | ||
140 | Register references in an expression are canonicalized before hashing | |
1bb98cec | 141 | the expression. This is done using `reg_qty' and qty_table `first_reg'. |
7afe21cc RK |
142 | The hash code of a register reference is computed using the quantity |
143 | number, not the register number. | |
144 | ||
145 | When the value of an expression changes, it is necessary to remove from the | |
146 | hash table not just that expression but all expressions whose values | |
147 | could be different as a result. | |
148 | ||
149 | 1. If the value changing is in memory, except in special cases | |
150 | ANYTHING referring to memory could be changed. That is because | |
151 | nobody knows where a pointer does not point. | |
152 | The function `invalidate_memory' removes what is necessary. | |
153 | ||
154 | The special cases are when the address is constant or is | |
155 | a constant plus a fixed register such as the frame pointer | |
156 | or a static chain pointer. When such addresses are stored in, | |
157 | we can tell exactly which other such addresses must be invalidated | |
158 | due to overlap. `invalidate' does this. | |
159 | All expressions that refer to non-constant | |
160 | memory addresses are also invalidated. `invalidate_memory' does this. | |
161 | ||
162 | 2. If the value changing is a register, all expressions | |
163 | containing references to that register, and only those, | |
164 | must be removed. | |
165 | ||
166 | Because searching the entire hash table for expressions that contain | |
167 | a register is very slow, we try to figure out when it isn't necessary. | |
168 | Precisely, this is necessary only when expressions have been | |
169 | entered in the hash table using this register, and then the value has | |
170 | changed, and then another expression wants to be added to refer to | |
171 | the register's new value. This sequence of circumstances is rare | |
172 | within any one basic block. | |
173 | ||
459281be KH |
174 | `REG_TICK' and `REG_IN_TABLE', accessors for members of |
175 | cse_reg_info, are used to detect this case. REG_TICK (i) is | |
176 | incremented whenever a value is stored in register i. | |
177 | REG_IN_TABLE (i) holds -1 if no references to register i have been | |
178 | entered in the table; otherwise, it contains the value REG_TICK (i) | |
179 | had when the references were entered. If we want to enter a | |
180 | reference and REG_IN_TABLE (i) != REG_TICK (i), we must scan and | |
181 | remove old references. Until we want to enter a new entry, the | |
182 | mere fact that the two vectors don't match makes the entries be | |
183 | ignored if anyone tries to match them. | |
7afe21cc RK |
184 | |
185 | Registers themselves are entered in the hash table as well as in | |
459281be KH |
186 | the equivalent-register chains. However, `REG_TICK' and |
187 | `REG_IN_TABLE' do not apply to expressions which are simple | |
7afe21cc RK |
188 | register references. These expressions are removed from the table |
189 | immediately when they become invalid, and this can be done even if | |
190 | we do not immediately search for all the expressions that refer to | |
191 | the register. | |
192 | ||
193 | A CLOBBER rtx in an instruction invalidates its operand for further | |
194 | reuse. A CLOBBER or SET rtx whose operand is a MEM:BLK | |
195 | invalidates everything that resides in memory. | |
196 | ||
197 | Related expressions: | |
198 | ||
199 | Constant expressions that differ only by an additive integer | |
200 | are called related. When a constant expression is put in | |
201 | the table, the related expression with no constant term | |
202 | is also entered. These are made to point at each other | |
203 | so that it is possible to find out if there exists any | |
204 | register equivalent to an expression related to a given expression. */ | |
278a83b2 | 205 | |
1bb98cec DM |
206 | /* Length of qty_table vector. We know in advance we will not need |
207 | a quantity number this big. */ | |
7afe21cc RK |
208 | |
209 | static int max_qty; | |
210 | ||
211 | /* Next quantity number to be allocated. | |
212 | This is 1 + the largest number needed so far. */ | |
213 | ||
214 | static int next_qty; | |
215 | ||
1bb98cec | 216 | /* Per-qty information tracking. |
7afe21cc | 217 | |
1bb98cec DM |
218 | `first_reg' and `last_reg' track the head and tail of the |
219 | chain of registers which currently contain this quantity. | |
7afe21cc | 220 | |
1bb98cec | 221 | `mode' contains the machine mode of this quantity. |
7afe21cc | 222 | |
1bb98cec DM |
223 | `const_rtx' holds the rtx of the constant value of this |
224 | quantity, if known. A summations of the frame/arg pointer | |
225 | and a constant can also be entered here. When this holds | |
226 | a known value, `const_insn' is the insn which stored the | |
227 | constant value. | |
7afe21cc | 228 | |
1bb98cec DM |
229 | `comparison_{code,const,qty}' are used to track when a |
230 | comparison between a quantity and some constant or register has | |
231 | been passed. In such a case, we know the results of the comparison | |
232 | in case we see it again. These members record a comparison that | |
233 | is known to be true. `comparison_code' holds the rtx code of such | |
234 | a comparison, else it is set to UNKNOWN and the other two | |
235 | comparison members are undefined. `comparison_const' holds | |
236 | the constant being compared against, or zero if the comparison | |
237 | is not against a constant. `comparison_qty' holds the quantity | |
238 | being compared against when the result is known. If the comparison | |
239 | is not with a register, `comparison_qty' is -1. */ | |
7afe21cc | 240 | |
1bb98cec DM |
241 | struct qty_table_elem |
242 | { | |
243 | rtx const_rtx; | |
20468884 | 244 | rtx_insn *const_insn; |
1bb98cec DM |
245 | rtx comparison_const; |
246 | int comparison_qty; | |
770ae6cc | 247 | unsigned int first_reg, last_reg; |
496324d0 DN |
248 | /* The sizes of these fields should match the sizes of the |
249 | code and mode fields of struct rtx_def (see rtl.h). */ | |
250 | ENUM_BITFIELD(rtx_code) comparison_code : 16; | |
251 | ENUM_BITFIELD(machine_mode) mode : 8; | |
1bb98cec | 252 | }; |
7afe21cc | 253 | |
1bb98cec DM |
254 | /* The table of all qtys, indexed by qty number. */ |
255 | static struct qty_table_elem *qty_table; | |
7afe21cc | 256 | |
7afe21cc RK |
257 | /* For machines that have a CC0, we do not record its value in the hash |
258 | table since its use is guaranteed to be the insn immediately following | |
259 | its definition and any other insn is presumed to invalidate it. | |
260 | ||
96fb470d SB |
261 | Instead, we store below the current and last value assigned to CC0. |
262 | If it should happen to be a constant, it is stored in preference | |
263 | to the actual assigned value. In case it is a constant, we store | |
264 | the mode in which the constant should be interpreted. */ | |
7afe21cc | 265 | |
96fb470d | 266 | static rtx this_insn_cc0, prev_insn_cc0; |
ef4bddc2 | 267 | static machine_mode this_insn_cc0_mode, prev_insn_cc0_mode; |
7afe21cc RK |
268 | |
269 | /* Insn being scanned. */ | |
270 | ||
20468884 | 271 | static rtx_insn *this_insn; |
f40751dd | 272 | static bool optimize_this_for_speed_p; |
7afe21cc | 273 | |
71d306d1 DE |
274 | /* Index by register number, gives the number of the next (or |
275 | previous) register in the chain of registers sharing the same | |
7afe21cc RK |
276 | value. |
277 | ||
278 | Or -1 if this register is at the end of the chain. | |
279 | ||
459281be | 280 | If REG_QTY (N) == -N - 1, reg_eqv_table[N].next is undefined. */ |
1bb98cec DM |
281 | |
282 | /* Per-register equivalence chain. */ | |
283 | struct reg_eqv_elem | |
284 | { | |
285 | int next, prev; | |
286 | }; | |
7afe21cc | 287 | |
1bb98cec DM |
288 | /* The table of all register equivalence chains. */ |
289 | static struct reg_eqv_elem *reg_eqv_table; | |
7afe21cc | 290 | |
14a774a9 RK |
291 | struct cse_reg_info |
292 | { | |
bc5e3b54 KH |
293 | /* The timestamp at which this register is initialized. */ |
294 | unsigned int timestamp; | |
9b1549b8 DM |
295 | |
296 | /* The quantity number of the register's current contents. */ | |
297 | int reg_qty; | |
298 | ||
299 | /* The number of times the register has been altered in the current | |
300 | basic block. */ | |
301 | int reg_tick; | |
302 | ||
30f72379 MM |
303 | /* The REG_TICK value at which rtx's containing this register are |
304 | valid in the hash table. If this does not equal the current | |
305 | reg_tick value, such expressions existing in the hash table are | |
306 | invalid. */ | |
307 | int reg_in_table; | |
46081bb3 SH |
308 | |
309 | /* The SUBREG that was set when REG_TICK was last incremented. Set | |
310 | to -1 if the last store was to the whole register, not a subreg. */ | |
5dd78e9a | 311 | unsigned int subreg_ticked; |
30f72379 | 312 | }; |
7afe21cc | 313 | |
bc5e3b54 | 314 | /* A table of cse_reg_info indexed by register numbers. */ |
f00822b2 | 315 | static struct cse_reg_info *cse_reg_info_table; |
c1edba58 | 316 | |
bc5e3b54 KH |
317 | /* The size of the above table. */ |
318 | static unsigned int cse_reg_info_table_size; | |
9b1549b8 | 319 | |
bc5e3b54 KH |
320 | /* The index of the first entry that has not been initialized. */ |
321 | static unsigned int cse_reg_info_table_first_uninitialized; | |
7afe21cc | 322 | |
bc5e3b54 | 323 | /* The timestamp at the beginning of the current run of |
932ad4d9 SB |
324 | cse_extended_basic_block. We increment this variable at the beginning of |
325 | the current run of cse_extended_basic_block. The timestamp field of a | |
bc5e3b54 KH |
326 | cse_reg_info entry matches the value of this variable if and only |
327 | if the entry has been initialized during the current run of | |
932ad4d9 | 328 | cse_extended_basic_block. */ |
bc5e3b54 | 329 | static unsigned int cse_reg_info_timestamp; |
7afe21cc | 330 | |
278a83b2 | 331 | /* A HARD_REG_SET containing all the hard registers for which there is |
7afe21cc RK |
332 | currently a REG expression in the hash table. Note the difference |
333 | from the above variables, which indicate if the REG is mentioned in some | |
334 | expression in the table. */ | |
335 | ||
336 | static HARD_REG_SET hard_regs_in_table; | |
337 | ||
2aac3a01 EB |
338 | /* True if CSE has altered the CFG. */ |
339 | static bool cse_cfg_altered; | |
7afe21cc | 340 | |
2aac3a01 EB |
341 | /* True if CSE has altered conditional jump insns in such a way |
342 | that jump optimization should be redone. */ | |
343 | static bool cse_jumps_altered; | |
7afe21cc | 344 | |
2aac3a01 EB |
345 | /* True if we put a LABEL_REF into the hash table for an INSN |
346 | without a REG_LABEL_OPERAND, we have to rerun jump after CSE | |
347 | to put in the note. */ | |
348 | static bool recorded_label_ref; | |
a5dfb4ee | 349 | |
7afe21cc RK |
350 | /* canon_hash stores 1 in do_not_record |
351 | if it notices a reference to CC0, PC, or some other volatile | |
352 | subexpression. */ | |
353 | ||
354 | static int do_not_record; | |
355 | ||
356 | /* canon_hash stores 1 in hash_arg_in_memory | |
357 | if it notices a reference to memory within the expression being hashed. */ | |
358 | ||
359 | static int hash_arg_in_memory; | |
360 | ||
7afe21cc RK |
361 | /* The hash table contains buckets which are chains of `struct table_elt's, |
362 | each recording one expression's information. | |
363 | That expression is in the `exp' field. | |
364 | ||
db048faf MM |
365 | The canon_exp field contains a canonical (from the point of view of |
366 | alias analysis) version of the `exp' field. | |
367 | ||
7afe21cc RK |
368 | Those elements with the same hash code are chained in both directions |
369 | through the `next_same_hash' and `prev_same_hash' fields. | |
370 | ||
371 | Each set of expressions with equivalent values | |
372 | are on a two-way chain through the `next_same_value' | |
373 | and `prev_same_value' fields, and all point with | |
374 | the `first_same_value' field at the first element in | |
375 | that chain. The chain is in order of increasing cost. | |
376 | Each element's cost value is in its `cost' field. | |
377 | ||
378 | The `in_memory' field is nonzero for elements that | |
379 | involve any reference to memory. These elements are removed | |
380 | whenever a write is done to an unidentified location in memory. | |
381 | To be safe, we assume that a memory address is unidentified unless | |
382 | the address is either a symbol constant or a constant plus | |
383 | the frame pointer or argument pointer. | |
384 | ||
7afe21cc RK |
385 | The `related_value' field is used to connect related expressions |
386 | (that differ by adding an integer). | |
387 | The related expressions are chained in a circular fashion. | |
388 | `related_value' is zero for expressions for which this | |
389 | chain is not useful. | |
390 | ||
391 | The `cost' field stores the cost of this element's expression. | |
630c79be BS |
392 | The `regcost' field stores the value returned by approx_reg_cost for |
393 | this element's expression. | |
7afe21cc RK |
394 | |
395 | The `is_const' flag is set if the element is a constant (including | |
396 | a fixed address). | |
397 | ||
398 | The `flag' field is used as a temporary during some search routines. | |
399 | ||
400 | The `mode' field is usually the same as GET_MODE (`exp'), but | |
401 | if `exp' is a CONST_INT and has no machine mode then the `mode' | |
402 | field is the mode it was being used as. Each constant is | |
403 | recorded separately for each mode it is used with. */ | |
404 | ||
7afe21cc RK |
405 | struct table_elt |
406 | { | |
407 | rtx exp; | |
db048faf | 408 | rtx canon_exp; |
7afe21cc RK |
409 | struct table_elt *next_same_hash; |
410 | struct table_elt *prev_same_hash; | |
411 | struct table_elt *next_same_value; | |
412 | struct table_elt *prev_same_value; | |
413 | struct table_elt *first_same_value; | |
414 | struct table_elt *related_value; | |
415 | int cost; | |
630c79be | 416 | int regcost; |
496324d0 DN |
417 | /* The size of this field should match the size |
418 | of the mode field of struct rtx_def (see rtl.h). */ | |
419 | ENUM_BITFIELD(machine_mode) mode : 8; | |
7afe21cc | 420 | char in_memory; |
7afe21cc RK |
421 | char is_const; |
422 | char flag; | |
423 | }; | |
424 | ||
7afe21cc RK |
425 | /* We don't want a lot of buckets, because we rarely have very many |
426 | things stored in the hash table, and a lot of buckets slows | |
427 | down a lot of loops that happen frequently. */ | |
9b1549b8 DM |
428 | #define HASH_SHIFT 5 |
429 | #define HASH_SIZE (1 << HASH_SHIFT) | |
430 | #define HASH_MASK (HASH_SIZE - 1) | |
7afe21cc RK |
431 | |
432 | /* Compute hash code of X in mode M. Special-case case where X is a pseudo | |
433 | register (hard registers may require `do_not_record' to be set). */ | |
434 | ||
435 | #define HASH(X, M) \ | |
f8cfc6aa | 436 | ((REG_P (X) && REGNO (X) >= FIRST_PSEUDO_REGISTER \ |
9b1549b8 DM |
437 | ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X))) \ |
438 | : canon_hash (X, M)) & HASH_MASK) | |
7afe21cc | 439 | |
0516f6fe SB |
440 | /* Like HASH, but without side-effects. */ |
441 | #define SAFE_HASH(X, M) \ | |
442 | ((REG_P (X) && REGNO (X) >= FIRST_PSEUDO_REGISTER \ | |
443 | ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X))) \ | |
444 | : safe_hash (X, M)) & HASH_MASK) | |
445 | ||
630c79be BS |
446 | /* Determine whether register number N is considered a fixed register for the |
447 | purpose of approximating register costs. | |
7afe21cc RK |
448 | It is desirable to replace other regs with fixed regs, to reduce need for |
449 | non-fixed hard regs. | |
553687c9 | 450 | A reg wins if it is either the frame pointer or designated as fixed. */ |
7afe21cc | 451 | #define FIXED_REGNO_P(N) \ |
8bc169f2 | 452 | ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \ |
6ab832bc | 453 | || fixed_regs[N] || global_regs[N]) |
7afe21cc RK |
454 | |
455 | /* Compute cost of X, as stored in the `cost' field of a table_elt. Fixed | |
ac07e066 RK |
456 | hard registers and pointers into the frame are the cheapest with a cost |
457 | of 0. Next come pseudos with a cost of one and other hard registers with | |
458 | a cost of 2. Aside from these special cases, call `rtx_cost'. */ | |
459 | ||
d67fb775 | 460 | #define CHEAP_REGNO(N) \ |
c3284718 | 461 | (REGNO_PTR_FRAME_P (N) \ |
d67fb775 | 462 | || (HARD_REGISTER_NUM_P (N) \ |
e7bb59fa | 463 | && FIXED_REGNO_P (N) && REGNO_REG_CLASS (N) != NO_REGS)) |
7afe21cc | 464 | |
e548c9df AM |
465 | #define COST(X, MODE) \ |
466 | (REG_P (X) ? 0 : notreg_cost (X, MODE, SET, 1)) | |
467 | #define COST_IN(X, MODE, OUTER, OPNO) \ | |
468 | (REG_P (X) ? 0 : notreg_cost (X, MODE, OUTER, OPNO)) | |
7afe21cc | 469 | |
30f72379 MM |
470 | /* Get the number of times this register has been updated in this |
471 | basic block. */ | |
472 | ||
bc5e3b54 | 473 | #define REG_TICK(N) (get_cse_reg_info (N)->reg_tick) |
30f72379 MM |
474 | |
475 | /* Get the point at which REG was recorded in the table. */ | |
476 | ||
bc5e3b54 | 477 | #define REG_IN_TABLE(N) (get_cse_reg_info (N)->reg_in_table) |
30f72379 | 478 | |
46081bb3 SH |
479 | /* Get the SUBREG set at the last increment to REG_TICK (-1 if not a |
480 | SUBREG). */ | |
481 | ||
bc5e3b54 | 482 | #define SUBREG_TICKED(N) (get_cse_reg_info (N)->subreg_ticked) |
46081bb3 | 483 | |
30f72379 MM |
484 | /* Get the quantity number for REG. */ |
485 | ||
bc5e3b54 | 486 | #define REG_QTY(N) (get_cse_reg_info (N)->reg_qty) |
30f72379 | 487 | |
7afe21cc | 488 | /* Determine if the quantity number for register X represents a valid index |
1bb98cec | 489 | into the qty_table. */ |
7afe21cc | 490 | |
08a69267 | 491 | #define REGNO_QTY_VALID_P(N) (REG_QTY (N) >= 0) |
7afe21cc | 492 | |
2c5bfdf7 AN |
493 | /* Compare table_elt X and Y and return true iff X is cheaper than Y. */ |
494 | ||
495 | #define CHEAPER(X, Y) \ | |
496 | (preferable ((X)->cost, (X)->regcost, (Y)->cost, (Y)->regcost) < 0) | |
497 | ||
9b1549b8 | 498 | static struct table_elt *table[HASH_SIZE]; |
7afe21cc RK |
499 | |
500 | /* Chain of `struct table_elt's made so far for this function | |
501 | but currently removed from the table. */ | |
502 | ||
503 | static struct table_elt *free_element_chain; | |
504 | ||
7afe21cc RK |
505 | /* Set to the cost of a constant pool reference if one was found for a |
506 | symbolic constant. If this was found, it means we should try to | |
507 | convert constants into constant pool entries if they don't fit in | |
508 | the insn. */ | |
509 | ||
510 | static int constant_pool_entries_cost; | |
dd0ba281 | 511 | static int constant_pool_entries_regcost; |
7afe21cc | 512 | |
24b97832 ILT |
513 | /* Trace a patch through the CFG. */ |
514 | ||
515 | struct branch_path | |
516 | { | |
517 | /* The basic block for this path entry. */ | |
518 | basic_block bb; | |
519 | }; | |
520 | ||
932ad4d9 SB |
521 | /* This data describes a block that will be processed by |
522 | cse_extended_basic_block. */ | |
6cd4575e | 523 | |
14a774a9 RK |
524 | struct cse_basic_block_data |
525 | { | |
6cd4575e RK |
526 | /* Total number of SETs in block. */ |
527 | int nsets; | |
6cd4575e RK |
528 | /* Size of current branch path, if any. */ |
529 | int path_size; | |
932ad4d9 | 530 | /* Current path, indicating which basic_blocks will be processed. */ |
24b97832 | 531 | struct branch_path *path; |
6cd4575e RK |
532 | }; |
533 | ||
6fb5fa3c DB |
534 | |
535 | /* Pointers to the live in/live out bitmaps for the boundaries of the | |
536 | current EBB. */ | |
537 | static bitmap cse_ebb_live_in, cse_ebb_live_out; | |
538 | ||
932ad4d9 SB |
539 | /* A simple bitmap to track which basic blocks have been visited |
540 | already as part of an already processed extended basic block. */ | |
541 | static sbitmap cse_visited_basic_blocks; | |
542 | ||
7080f735 | 543 | static bool fixed_base_plus_p (rtx x); |
e548c9df | 544 | static int notreg_cost (rtx, machine_mode, enum rtx_code, int); |
56ae04af | 545 | static int preferable (int, int, int, int); |
7080f735 | 546 | static void new_basic_block (void); |
ef4bddc2 | 547 | static void make_new_qty (unsigned int, machine_mode); |
7080f735 AJ |
548 | static void make_regs_eqv (unsigned int, unsigned int); |
549 | static void delete_reg_equiv (unsigned int); | |
550 | static int mention_regs (rtx); | |
551 | static int insert_regs (rtx, struct table_elt *, int); | |
552 | static void remove_from_table (struct table_elt *, unsigned); | |
d556d181 | 553 | static void remove_pseudo_from_table (rtx, unsigned); |
ef4bddc2 RS |
554 | static struct table_elt *lookup (rtx, unsigned, machine_mode); |
555 | static struct table_elt *lookup_for_remove (rtx, unsigned, machine_mode); | |
7080f735 | 556 | static rtx lookup_as_function (rtx, enum rtx_code); |
2c5bfdf7 | 557 | static struct table_elt *insert_with_costs (rtx, struct table_elt *, unsigned, |
ef4bddc2 | 558 | machine_mode, int, int); |
7080f735 | 559 | static struct table_elt *insert (rtx, struct table_elt *, unsigned, |
ef4bddc2 | 560 | machine_mode); |
7080f735 | 561 | static void merge_equiv_classes (struct table_elt *, struct table_elt *); |
ef4bddc2 | 562 | static void invalidate (rtx, machine_mode); |
7080f735 AJ |
563 | static void remove_invalid_refs (unsigned int); |
564 | static void remove_invalid_subreg_refs (unsigned int, unsigned int, | |
ef4bddc2 | 565 | machine_mode); |
7080f735 AJ |
566 | static void rehash_using_reg (rtx); |
567 | static void invalidate_memory (void); | |
568 | static void invalidate_for_call (void); | |
569 | static rtx use_related_value (rtx, struct table_elt *); | |
0516f6fe | 570 | |
ef4bddc2 RS |
571 | static inline unsigned canon_hash (rtx, machine_mode); |
572 | static inline unsigned safe_hash (rtx, machine_mode); | |
e855c69d | 573 | static inline unsigned hash_rtx_string (const char *); |
0516f6fe | 574 | |
20468884 | 575 | static rtx canon_reg (rtx, rtx_insn *); |
7080f735 | 576 | static enum rtx_code find_comparison_args (enum rtx_code, rtx *, rtx *, |
ef4bddc2 RS |
577 | machine_mode *, |
578 | machine_mode *); | |
20468884 | 579 | static rtx fold_rtx (rtx, rtx_insn *); |
7080f735 | 580 | static rtx equiv_constant (rtx); |
20468884 | 581 | static void record_jump_equiv (rtx_insn *, bool); |
ef4bddc2 | 582 | static void record_jump_cond (enum rtx_code, machine_mode, rtx, rtx, |
7080f735 | 583 | int); |
20468884 | 584 | static void cse_insn (rtx_insn *); |
932ad4d9 | 585 | static void cse_prescan_path (struct cse_basic_block_data *); |
20468884 DM |
586 | static void invalidate_from_clobbers (rtx_insn *); |
587 | static void invalidate_from_sets_and_clobbers (rtx_insn *); | |
6fb5fa3c | 588 | static rtx cse_process_notes (rtx, rtx, bool *); |
932ad4d9 | 589 | static void cse_extended_basic_block (struct cse_basic_block_data *); |
7080f735 | 590 | extern void dump_class (struct table_elt*); |
bc5e3b54 KH |
591 | static void get_cse_reg_info_1 (unsigned int regno); |
592 | static struct cse_reg_info * get_cse_reg_info (unsigned int regno); | |
7080f735 AJ |
593 | |
594 | static void flush_hash_table (void); | |
20468884 DM |
595 | static bool insn_live_p (rtx_insn *, int *); |
596 | static bool set_live_p (rtx, rtx_insn *, int *); | |
20468884 DM |
597 | static void cse_change_cc_mode_insn (rtx_insn *, rtx); |
598 | static void cse_change_cc_mode_insns (rtx_insn *, rtx_insn *, rtx); | |
ef4bddc2 | 599 | static machine_mode cse_cc_succs (basic_block, basic_block, rtx, rtx, |
31e9ebaf | 600 | bool); |
7afe21cc | 601 | \f |
2f93eea8 PB |
602 | |
603 | #undef RTL_HOOKS_GEN_LOWPART | |
604 | #define RTL_HOOKS_GEN_LOWPART gen_lowpart_if_possible | |
605 | ||
606 | static const struct rtl_hooks cse_rtl_hooks = RTL_HOOKS_INITIALIZER; | |
607 | \f | |
6399c0ab | 608 | /* Nonzero if X has the form (PLUS frame-pointer integer). */ |
4977bab6 ZW |
609 | |
610 | static bool | |
7080f735 | 611 | fixed_base_plus_p (rtx x) |
4977bab6 ZW |
612 | { |
613 | switch (GET_CODE (x)) | |
614 | { | |
615 | case REG: | |
616 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx) | |
617 | return true; | |
618 | if (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
619 | return true; | |
4977bab6 ZW |
620 | return false; |
621 | ||
622 | case PLUS: | |
481683e1 | 623 | if (!CONST_INT_P (XEXP (x, 1))) |
4977bab6 ZW |
624 | return false; |
625 | return fixed_base_plus_p (XEXP (x, 0)); | |
626 | ||
4977bab6 ZW |
627 | default: |
628 | return false; | |
629 | } | |
630 | } | |
631 | ||
a4c6502a MM |
632 | /* Dump the expressions in the equivalence class indicated by CLASSP. |
633 | This function is used only for debugging. */ | |
711417cd | 634 | DEBUG_FUNCTION void |
7080f735 | 635 | dump_class (struct table_elt *classp) |
a4c6502a MM |
636 | { |
637 | struct table_elt *elt; | |
638 | ||
639 | fprintf (stderr, "Equivalence chain for "); | |
640 | print_rtl (stderr, classp->exp); | |
641 | fprintf (stderr, ": \n"); | |
278a83b2 | 642 | |
a4c6502a MM |
643 | for (elt = classp->first_same_value; elt; elt = elt->next_same_value) |
644 | { | |
645 | print_rtl (stderr, elt->exp); | |
646 | fprintf (stderr, "\n"); | |
647 | } | |
648 | } | |
649 | ||
e89b312e RS |
650 | /* Return an estimate of the cost of the registers used in an rtx. |
651 | This is mostly the number of different REG expressions in the rtx; | |
652 | however for some exceptions like fixed registers we use a cost of | |
653 | 0. If any other hard register reference occurs, return MAX_COST. */ | |
be8ac49a | 654 | |
630c79be | 655 | static int |
e89b312e | 656 | approx_reg_cost (const_rtx x) |
630c79be | 657 | { |
e89b312e RS |
658 | int cost = 0; |
659 | subrtx_iterator::array_type array; | |
660 | FOR_EACH_SUBRTX (iter, array, x, NONCONST) | |
c863f8c2 | 661 | { |
e89b312e RS |
662 | const_rtx x = *iter; |
663 | if (REG_P (x)) | |
c863f8c2 | 664 | { |
e89b312e RS |
665 | unsigned int regno = REGNO (x); |
666 | if (!CHEAP_REGNO (regno)) | |
c863f8c2 | 667 | { |
e89b312e RS |
668 | if (regno < FIRST_PSEUDO_REGISTER) |
669 | { | |
670 | if (targetm.small_register_classes_for_mode_p (GET_MODE (x))) | |
671 | return MAX_COST; | |
672 | cost += 2; | |
673 | } | |
674 | else | |
675 | cost += 1; | |
c863f8c2 | 676 | } |
c863f8c2 DM |
677 | } |
678 | } | |
c863f8c2 | 679 | return cost; |
630c79be BS |
680 | } |
681 | ||
682 | /* Return a negative value if an rtx A, whose costs are given by COST_A | |
683 | and REGCOST_A, is more desirable than an rtx B. | |
684 | Return a positive value if A is less desirable, or 0 if the two are | |
685 | equally good. */ | |
686 | static int | |
56ae04af | 687 | preferable (int cost_a, int regcost_a, int cost_b, int regcost_b) |
630c79be | 688 | { |
423adbb9 | 689 | /* First, get rid of cases involving expressions that are entirely |
f1c1dfc3 BS |
690 | unwanted. */ |
691 | if (cost_a != cost_b) | |
692 | { | |
693 | if (cost_a == MAX_COST) | |
694 | return 1; | |
695 | if (cost_b == MAX_COST) | |
696 | return -1; | |
697 | } | |
698 | ||
699 | /* Avoid extending lifetimes of hardregs. */ | |
700 | if (regcost_a != regcost_b) | |
701 | { | |
702 | if (regcost_a == MAX_COST) | |
703 | return 1; | |
704 | if (regcost_b == MAX_COST) | |
705 | return -1; | |
706 | } | |
707 | ||
708 | /* Normal operation costs take precedence. */ | |
630c79be BS |
709 | if (cost_a != cost_b) |
710 | return cost_a - cost_b; | |
f1c1dfc3 | 711 | /* Only if these are identical consider effects on register pressure. */ |
630c79be BS |
712 | if (regcost_a != regcost_b) |
713 | return regcost_a - regcost_b; | |
714 | return 0; | |
715 | } | |
716 | ||
954a5693 RK |
717 | /* Internal function, to compute cost when X is not a register; called |
718 | from COST macro to keep it simple. */ | |
719 | ||
720 | static int | |
e548c9df | 721 | notreg_cost (rtx x, machine_mode mode, enum rtx_code outer, int opno) |
954a5693 RK |
722 | { |
723 | return ((GET_CODE (x) == SUBREG | |
f8cfc6aa | 724 | && REG_P (SUBREG_REG (x)) |
e548c9df | 725 | && GET_MODE_CLASS (mode) == MODE_INT |
954a5693 | 726 | && GET_MODE_CLASS (GET_MODE (SUBREG_REG (x))) == MODE_INT |
e548c9df | 727 | && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))) |
954a5693 | 728 | && subreg_lowpart_p (x) |
e548c9df | 729 | && TRULY_NOOP_TRUNCATION_MODES_P (mode, GET_MODE (SUBREG_REG (x)))) |
630c79be | 730 | ? 0 |
e548c9df | 731 | : rtx_cost (x, mode, outer, opno, optimize_this_for_speed_p) * 2); |
954a5693 RK |
732 | } |
733 | ||
01329426 | 734 | \f |
bc5e3b54 | 735 | /* Initialize CSE_REG_INFO_TABLE. */ |
9b1549b8 | 736 | |
bc5e3b54 KH |
737 | static void |
738 | init_cse_reg_info (unsigned int nregs) | |
739 | { | |
740 | /* Do we need to grow the table? */ | |
741 | if (nregs > cse_reg_info_table_size) | |
30f72379 | 742 | { |
bc5e3b54 KH |
743 | unsigned int new_size; |
744 | ||
745 | if (cse_reg_info_table_size < 2048) | |
30f72379 | 746 | { |
bc5e3b54 KH |
747 | /* Compute a new size that is a power of 2 and no smaller |
748 | than the large of NREGS and 64. */ | |
749 | new_size = (cse_reg_info_table_size | |
750 | ? cse_reg_info_table_size : 64); | |
751 | ||
752 | while (new_size < nregs) | |
753 | new_size *= 2; | |
30f72379 MM |
754 | } |
755 | else | |
1590d0d4 | 756 | { |
bc5e3b54 KH |
757 | /* If we need a big table, allocate just enough to hold |
758 | NREGS registers. */ | |
759 | new_size = nregs; | |
1590d0d4 | 760 | } |
9b1549b8 | 761 | |
bc5e3b54 | 762 | /* Reallocate the table with NEW_SIZE entries. */ |
04695783 | 763 | free (cse_reg_info_table); |
5ed6ace5 | 764 | cse_reg_info_table = XNEWVEC (struct cse_reg_info, new_size); |
bc5e3b54 | 765 | cse_reg_info_table_size = new_size; |
a811c672 | 766 | cse_reg_info_table_first_uninitialized = 0; |
bc5e3b54 KH |
767 | } |
768 | ||
769 | /* Do we have all of the first NREGS entries initialized? */ | |
770 | if (cse_reg_info_table_first_uninitialized < nregs) | |
771 | { | |
772 | unsigned int old_timestamp = cse_reg_info_timestamp - 1; | |
773 | unsigned int i; | |
774 | ||
775 | /* Put the old timestamp on newly allocated entries so that they | |
776 | will all be considered out of date. We do not touch those | |
777 | entries beyond the first NREGS entries to be nice to the | |
778 | virtual memory. */ | |
779 | for (i = cse_reg_info_table_first_uninitialized; i < nregs; i++) | |
780 | cse_reg_info_table[i].timestamp = old_timestamp; | |
30f72379 | 781 | |
bc5e3b54 | 782 | cse_reg_info_table_first_uninitialized = nregs; |
30f72379 | 783 | } |
bc5e3b54 KH |
784 | } |
785 | ||
a52aff23 | 786 | /* Given REGNO, initialize the cse_reg_info entry for REGNO. */ |
bc5e3b54 KH |
787 | |
788 | static void | |
789 | get_cse_reg_info_1 (unsigned int regno) | |
790 | { | |
791 | /* Set TIMESTAMP field to CSE_REG_INFO_TIMESTAMP so that this | |
792 | entry will be considered to have been initialized. */ | |
793 | cse_reg_info_table[regno].timestamp = cse_reg_info_timestamp; | |
794 | ||
795 | /* Initialize the rest of the entry. */ | |
796 | cse_reg_info_table[regno].reg_tick = 1; | |
797 | cse_reg_info_table[regno].reg_in_table = -1; | |
798 | cse_reg_info_table[regno].subreg_ticked = -1; | |
799 | cse_reg_info_table[regno].reg_qty = -regno - 1; | |
800 | } | |
801 | ||
802 | /* Find a cse_reg_info entry for REGNO. */ | |
30f72379 | 803 | |
bc5e3b54 KH |
804 | static inline struct cse_reg_info * |
805 | get_cse_reg_info (unsigned int regno) | |
806 | { | |
807 | struct cse_reg_info *p = &cse_reg_info_table[regno]; | |
808 | ||
782c0a3e KH |
809 | /* If this entry has not been initialized, go ahead and initialize |
810 | it. */ | |
bc5e3b54 KH |
811 | if (p->timestamp != cse_reg_info_timestamp) |
812 | get_cse_reg_info_1 (regno); | |
30f72379 | 813 | |
9b1549b8 | 814 | return p; |
30f72379 MM |
815 | } |
816 | ||
7afe21cc RK |
817 | /* Clear the hash table and initialize each register with its own quantity, |
818 | for a new basic block. */ | |
819 | ||
820 | static void | |
7080f735 | 821 | new_basic_block (void) |
7afe21cc | 822 | { |
b3694847 | 823 | int i; |
7afe21cc | 824 | |
08a69267 | 825 | next_qty = 0; |
7afe21cc | 826 | |
a52aff23 | 827 | /* Invalidate cse_reg_info_table. */ |
bc5e3b54 | 828 | cse_reg_info_timestamp++; |
7afe21cc | 829 | |
bc5e3b54 | 830 | /* Clear out hash table state for this pass. */ |
7afe21cc RK |
831 | CLEAR_HARD_REG_SET (hard_regs_in_table); |
832 | ||
833 | /* The per-quantity values used to be initialized here, but it is | |
834 | much faster to initialize each as it is made in `make_new_qty'. */ | |
835 | ||
9b1549b8 | 836 | for (i = 0; i < HASH_SIZE; i++) |
7afe21cc | 837 | { |
9b1549b8 DM |
838 | struct table_elt *first; |
839 | ||
840 | first = table[i]; | |
841 | if (first != NULL) | |
7afe21cc | 842 | { |
9b1549b8 DM |
843 | struct table_elt *last = first; |
844 | ||
845 | table[i] = NULL; | |
846 | ||
847 | while (last->next_same_hash != NULL) | |
848 | last = last->next_same_hash; | |
849 | ||
850 | /* Now relink this hash entire chain into | |
851 | the free element list. */ | |
852 | ||
853 | last->next_same_hash = free_element_chain; | |
854 | free_element_chain = first; | |
7afe21cc RK |
855 | } |
856 | } | |
857 | ||
7afe21cc | 858 | prev_insn_cc0 = 0; |
7afe21cc RK |
859 | } |
860 | ||
1bb98cec DM |
861 | /* Say that register REG contains a quantity in mode MODE not in any |
862 | register before and initialize that quantity. */ | |
7afe21cc RK |
863 | |
864 | static void | |
ef4bddc2 | 865 | make_new_qty (unsigned int reg, machine_mode mode) |
7afe21cc | 866 | { |
b3694847 SS |
867 | int q; |
868 | struct qty_table_elem *ent; | |
869 | struct reg_eqv_elem *eqv; | |
7afe21cc | 870 | |
341c100f | 871 | gcc_assert (next_qty < max_qty); |
7afe21cc | 872 | |
30f72379 | 873 | q = REG_QTY (reg) = next_qty++; |
1bb98cec DM |
874 | ent = &qty_table[q]; |
875 | ent->first_reg = reg; | |
876 | ent->last_reg = reg; | |
877 | ent->mode = mode; | |
20468884 | 878 | ent->const_rtx = ent->const_insn = NULL; |
1bb98cec DM |
879 | ent->comparison_code = UNKNOWN; |
880 | ||
881 | eqv = ®_eqv_table[reg]; | |
882 | eqv->next = eqv->prev = -1; | |
7afe21cc RK |
883 | } |
884 | ||
885 | /* Make reg NEW equivalent to reg OLD. | |
886 | OLD is not changing; NEW is. */ | |
887 | ||
888 | static void | |
32e9fa48 | 889 | make_regs_eqv (unsigned int new_reg, unsigned int old_reg) |
7afe21cc | 890 | { |
770ae6cc | 891 | unsigned int lastr, firstr; |
32e9fa48 | 892 | int q = REG_QTY (old_reg); |
770ae6cc | 893 | struct qty_table_elem *ent; |
1bb98cec DM |
894 | |
895 | ent = &qty_table[q]; | |
7afe21cc RK |
896 | |
897 | /* Nothing should become eqv until it has a "non-invalid" qty number. */ | |
32e9fa48 | 898 | gcc_assert (REGNO_QTY_VALID_P (old_reg)); |
7afe21cc | 899 | |
32e9fa48 | 900 | REG_QTY (new_reg) = q; |
1bb98cec DM |
901 | firstr = ent->first_reg; |
902 | lastr = ent->last_reg; | |
7afe21cc RK |
903 | |
904 | /* Prefer fixed hard registers to anything. Prefer pseudo regs to other | |
905 | hard regs. Among pseudos, if NEW will live longer than any other reg | |
906 | of the same qty, and that is beyond the current basic block, | |
907 | make it the new canonical replacement for this qty. */ | |
908 | if (! (firstr < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (firstr)) | |
909 | /* Certain fixed registers might be of the class NO_REGS. This means | |
910 | that not only can they not be allocated by the compiler, but | |
830a38ee | 911 | they cannot be used in substitutions or canonicalizations |
7afe21cc | 912 | either. */ |
32e9fa48 KG |
913 | && (new_reg >= FIRST_PSEUDO_REGISTER || REGNO_REG_CLASS (new_reg) != NO_REGS) |
914 | && ((new_reg < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (new_reg)) | |
915 | || (new_reg >= FIRST_PSEUDO_REGISTER | |
7afe21cc | 916 | && (firstr < FIRST_PSEUDO_REGISTER |
32e9fa48 | 917 | || (bitmap_bit_p (cse_ebb_live_out, new_reg) |
6fb5fa3c | 918 | && !bitmap_bit_p (cse_ebb_live_out, firstr)) |
32e9fa48 | 919 | || (bitmap_bit_p (cse_ebb_live_in, new_reg) |
6fb5fa3c | 920 | && !bitmap_bit_p (cse_ebb_live_in, firstr)))))) |
7afe21cc | 921 | { |
32e9fa48 KG |
922 | reg_eqv_table[firstr].prev = new_reg; |
923 | reg_eqv_table[new_reg].next = firstr; | |
924 | reg_eqv_table[new_reg].prev = -1; | |
925 | ent->first_reg = new_reg; | |
7afe21cc RK |
926 | } |
927 | else | |
928 | { | |
929 | /* If NEW is a hard reg (known to be non-fixed), insert at end. | |
930 | Otherwise, insert before any non-fixed hard regs that are at the | |
931 | end. Registers of class NO_REGS cannot be used as an | |
932 | equivalent for anything. */ | |
1bb98cec | 933 | while (lastr < FIRST_PSEUDO_REGISTER && reg_eqv_table[lastr].prev >= 0 |
7afe21cc | 934 | && (REGNO_REG_CLASS (lastr) == NO_REGS || ! FIXED_REGNO_P (lastr)) |
32e9fa48 | 935 | && new_reg >= FIRST_PSEUDO_REGISTER) |
1bb98cec | 936 | lastr = reg_eqv_table[lastr].prev; |
32e9fa48 | 937 | reg_eqv_table[new_reg].next = reg_eqv_table[lastr].next; |
1bb98cec | 938 | if (reg_eqv_table[lastr].next >= 0) |
32e9fa48 | 939 | reg_eqv_table[reg_eqv_table[lastr].next].prev = new_reg; |
7afe21cc | 940 | else |
32e9fa48 KG |
941 | qty_table[q].last_reg = new_reg; |
942 | reg_eqv_table[lastr].next = new_reg; | |
943 | reg_eqv_table[new_reg].prev = lastr; | |
7afe21cc RK |
944 | } |
945 | } | |
946 | ||
947 | /* Remove REG from its equivalence class. */ | |
948 | ||
949 | static void | |
7080f735 | 950 | delete_reg_equiv (unsigned int reg) |
7afe21cc | 951 | { |
b3694847 SS |
952 | struct qty_table_elem *ent; |
953 | int q = REG_QTY (reg); | |
954 | int p, n; | |
7afe21cc | 955 | |
a4e262bc | 956 | /* If invalid, do nothing. */ |
08a69267 | 957 | if (! REGNO_QTY_VALID_P (reg)) |
7afe21cc RK |
958 | return; |
959 | ||
1bb98cec DM |
960 | ent = &qty_table[q]; |
961 | ||
962 | p = reg_eqv_table[reg].prev; | |
963 | n = reg_eqv_table[reg].next; | |
a4e262bc | 964 | |
7afe21cc | 965 | if (n != -1) |
1bb98cec | 966 | reg_eqv_table[n].prev = p; |
7afe21cc | 967 | else |
1bb98cec | 968 | ent->last_reg = p; |
7afe21cc | 969 | if (p != -1) |
1bb98cec | 970 | reg_eqv_table[p].next = n; |
7afe21cc | 971 | else |
1bb98cec | 972 | ent->first_reg = n; |
7afe21cc | 973 | |
08a69267 | 974 | REG_QTY (reg) = -reg - 1; |
7afe21cc RK |
975 | } |
976 | ||
977 | /* Remove any invalid expressions from the hash table | |
978 | that refer to any of the registers contained in expression X. | |
979 | ||
980 | Make sure that newly inserted references to those registers | |
981 | as subexpressions will be considered valid. | |
982 | ||
983 | mention_regs is not called when a register itself | |
984 | is being stored in the table. | |
985 | ||
986 | Return 1 if we have done something that may have changed the hash code | |
987 | of X. */ | |
988 | ||
989 | static int | |
7080f735 | 990 | mention_regs (rtx x) |
7afe21cc | 991 | { |
b3694847 SS |
992 | enum rtx_code code; |
993 | int i, j; | |
994 | const char *fmt; | |
995 | int changed = 0; | |
7afe21cc RK |
996 | |
997 | if (x == 0) | |
e5f6a288 | 998 | return 0; |
7afe21cc RK |
999 | |
1000 | code = GET_CODE (x); | |
1001 | if (code == REG) | |
1002 | { | |
770ae6cc | 1003 | unsigned int regno = REGNO (x); |
09e18274 | 1004 | unsigned int endregno = END_REGNO (x); |
770ae6cc | 1005 | unsigned int i; |
7afe21cc RK |
1006 | |
1007 | for (i = regno; i < endregno; i++) | |
1008 | { | |
30f72379 | 1009 | if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i)) |
7afe21cc RK |
1010 | remove_invalid_refs (i); |
1011 | ||
30f72379 | 1012 | REG_IN_TABLE (i) = REG_TICK (i); |
46081bb3 | 1013 | SUBREG_TICKED (i) = -1; |
7afe21cc RK |
1014 | } |
1015 | ||
1016 | return 0; | |
1017 | } | |
1018 | ||
34c73909 R |
1019 | /* If this is a SUBREG, we don't want to discard other SUBREGs of the same |
1020 | pseudo if they don't use overlapping words. We handle only pseudos | |
1021 | here for simplicity. */ | |
f8cfc6aa | 1022 | if (code == SUBREG && REG_P (SUBREG_REG (x)) |
34c73909 R |
1023 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER) |
1024 | { | |
770ae6cc | 1025 | unsigned int i = REGNO (SUBREG_REG (x)); |
34c73909 | 1026 | |
30f72379 | 1027 | if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i)) |
34c73909 | 1028 | { |
46081bb3 SH |
1029 | /* If REG_IN_TABLE (i) differs from REG_TICK (i) by one, and |
1030 | the last store to this register really stored into this | |
1031 | subreg, then remove the memory of this subreg. | |
1032 | Otherwise, remove any memory of the entire register and | |
1033 | all its subregs from the table. */ | |
1034 | if (REG_TICK (i) - REG_IN_TABLE (i) > 1 | |
5dd78e9a | 1035 | || SUBREG_TICKED (i) != REGNO (SUBREG_REG (x))) |
34c73909 R |
1036 | remove_invalid_refs (i); |
1037 | else | |
ddef6bc7 | 1038 | remove_invalid_subreg_refs (i, SUBREG_BYTE (x), GET_MODE (x)); |
34c73909 R |
1039 | } |
1040 | ||
30f72379 | 1041 | REG_IN_TABLE (i) = REG_TICK (i); |
5dd78e9a | 1042 | SUBREG_TICKED (i) = REGNO (SUBREG_REG (x)); |
34c73909 R |
1043 | return 0; |
1044 | } | |
1045 | ||
7afe21cc RK |
1046 | /* If X is a comparison or a COMPARE and either operand is a register |
1047 | that does not have a quantity, give it one. This is so that a later | |
1048 | call to record_jump_equiv won't cause X to be assigned a different | |
1049 | hash code and not found in the table after that call. | |
1050 | ||
1051 | It is not necessary to do this here, since rehash_using_reg can | |
1052 | fix up the table later, but doing this here eliminates the need to | |
1053 | call that expensive function in the most common case where the only | |
1054 | use of the register is in the comparison. */ | |
1055 | ||
ec8e098d | 1056 | if (code == COMPARE || COMPARISON_P (x)) |
7afe21cc | 1057 | { |
f8cfc6aa | 1058 | if (REG_P (XEXP (x, 0)) |
7afe21cc | 1059 | && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 0)))) |
9714cf43 | 1060 | if (insert_regs (XEXP (x, 0), NULL, 0)) |
7afe21cc RK |
1061 | { |
1062 | rehash_using_reg (XEXP (x, 0)); | |
1063 | changed = 1; | |
1064 | } | |
1065 | ||
f8cfc6aa | 1066 | if (REG_P (XEXP (x, 1)) |
7afe21cc | 1067 | && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 1)))) |
9714cf43 | 1068 | if (insert_regs (XEXP (x, 1), NULL, 0)) |
7afe21cc RK |
1069 | { |
1070 | rehash_using_reg (XEXP (x, 1)); | |
1071 | changed = 1; | |
1072 | } | |
1073 | } | |
1074 | ||
1075 | fmt = GET_RTX_FORMAT (code); | |
1076 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1077 | if (fmt[i] == 'e') | |
1078 | changed |= mention_regs (XEXP (x, i)); | |
1079 | else if (fmt[i] == 'E') | |
1080 | for (j = 0; j < XVECLEN (x, i); j++) | |
1081 | changed |= mention_regs (XVECEXP (x, i, j)); | |
1082 | ||
1083 | return changed; | |
1084 | } | |
1085 | ||
1086 | /* Update the register quantities for inserting X into the hash table | |
1087 | with a value equivalent to CLASSP. | |
1088 | (If the class does not contain a REG, it is irrelevant.) | |
1089 | If MODIFIED is nonzero, X is a destination; it is being modified. | |
1090 | Note that delete_reg_equiv should be called on a register | |
1091 | before insert_regs is done on that register with MODIFIED != 0. | |
1092 | ||
1093 | Nonzero value means that elements of reg_qty have changed | |
1094 | so X's hash code may be different. */ | |
1095 | ||
1096 | static int | |
7080f735 | 1097 | insert_regs (rtx x, struct table_elt *classp, int modified) |
7afe21cc | 1098 | { |
f8cfc6aa | 1099 | if (REG_P (x)) |
7afe21cc | 1100 | { |
770ae6cc RK |
1101 | unsigned int regno = REGNO (x); |
1102 | int qty_valid; | |
7afe21cc | 1103 | |
1ff0c00d RK |
1104 | /* If REGNO is in the equivalence table already but is of the |
1105 | wrong mode for that equivalence, don't do anything here. */ | |
1106 | ||
1bb98cec DM |
1107 | qty_valid = REGNO_QTY_VALID_P (regno); |
1108 | if (qty_valid) | |
1109 | { | |
1110 | struct qty_table_elem *ent = &qty_table[REG_QTY (regno)]; | |
1ff0c00d | 1111 | |
1bb98cec DM |
1112 | if (ent->mode != GET_MODE (x)) |
1113 | return 0; | |
1114 | } | |
1115 | ||
1116 | if (modified || ! qty_valid) | |
7afe21cc RK |
1117 | { |
1118 | if (classp) | |
1119 | for (classp = classp->first_same_value; | |
1120 | classp != 0; | |
1121 | classp = classp->next_same_value) | |
f8cfc6aa | 1122 | if (REG_P (classp->exp) |
7afe21cc RK |
1123 | && GET_MODE (classp->exp) == GET_MODE (x)) |
1124 | { | |
cd928652 ZD |
1125 | unsigned c_regno = REGNO (classp->exp); |
1126 | ||
1127 | gcc_assert (REGNO_QTY_VALID_P (c_regno)); | |
1128 | ||
1129 | /* Suppose that 5 is hard reg and 100 and 101 are | |
1130 | pseudos. Consider | |
1131 | ||
1132 | (set (reg:si 100) (reg:si 5)) | |
1133 | (set (reg:si 5) (reg:si 100)) | |
1134 | (set (reg:di 101) (reg:di 5)) | |
1135 | ||
1136 | We would now set REG_QTY (101) = REG_QTY (5), but the | |
1137 | entry for 5 is in SImode. When we use this later in | |
1138 | copy propagation, we get the register in wrong mode. */ | |
1139 | if (qty_table[REG_QTY (c_regno)].mode != GET_MODE (x)) | |
1140 | continue; | |
1141 | ||
1142 | make_regs_eqv (regno, c_regno); | |
7afe21cc RK |
1143 | return 1; |
1144 | } | |
1145 | ||
d9f20424 R |
1146 | /* Mention_regs for a SUBREG checks if REG_TICK is exactly one larger |
1147 | than REG_IN_TABLE to find out if there was only a single preceding | |
1148 | invalidation - for the SUBREG - or another one, which would be | |
1149 | for the full register. However, if we find here that REG_TICK | |
1150 | indicates that the register is invalid, it means that it has | |
1151 | been invalidated in a separate operation. The SUBREG might be used | |
1152 | now (then this is a recursive call), or we might use the full REG | |
1153 | now and a SUBREG of it later. So bump up REG_TICK so that | |
1154 | mention_regs will do the right thing. */ | |
1155 | if (! modified | |
1156 | && REG_IN_TABLE (regno) >= 0 | |
1157 | && REG_TICK (regno) == REG_IN_TABLE (regno) + 1) | |
1158 | REG_TICK (regno)++; | |
1bb98cec | 1159 | make_new_qty (regno, GET_MODE (x)); |
7afe21cc RK |
1160 | return 1; |
1161 | } | |
cdf4112f TG |
1162 | |
1163 | return 0; | |
7afe21cc | 1164 | } |
c610adec RK |
1165 | |
1166 | /* If X is a SUBREG, we will likely be inserting the inner register in the | |
1167 | table. If that register doesn't have an assigned quantity number at | |
1168 | this point but does later, the insertion that we will be doing now will | |
1169 | not be accessible because its hash code will have changed. So assign | |
1170 | a quantity number now. */ | |
1171 | ||
f8cfc6aa | 1172 | else if (GET_CODE (x) == SUBREG && REG_P (SUBREG_REG (x)) |
c610adec RK |
1173 | && ! REGNO_QTY_VALID_P (REGNO (SUBREG_REG (x)))) |
1174 | { | |
9714cf43 | 1175 | insert_regs (SUBREG_REG (x), NULL, 0); |
34c73909 | 1176 | mention_regs (x); |
c610adec RK |
1177 | return 1; |
1178 | } | |
7afe21cc RK |
1179 | else |
1180 | return mention_regs (x); | |
1181 | } | |
1182 | \f | |
2c5bfdf7 AN |
1183 | |
1184 | /* Compute upper and lower anchors for CST. Also compute the offset of CST | |
1185 | from these anchors/bases such that *_BASE + *_OFFS = CST. Return false iff | |
1186 | CST is equal to an anchor. */ | |
1187 | ||
1188 | static bool | |
1189 | compute_const_anchors (rtx cst, | |
1190 | HOST_WIDE_INT *lower_base, HOST_WIDE_INT *lower_offs, | |
1191 | HOST_WIDE_INT *upper_base, HOST_WIDE_INT *upper_offs) | |
1192 | { | |
1193 | HOST_WIDE_INT n = INTVAL (cst); | |
1194 | ||
1195 | *lower_base = n & ~(targetm.const_anchor - 1); | |
1196 | if (*lower_base == n) | |
1197 | return false; | |
1198 | ||
1199 | *upper_base = | |
1200 | (n + (targetm.const_anchor - 1)) & ~(targetm.const_anchor - 1); | |
1201 | *upper_offs = n - *upper_base; | |
1202 | *lower_offs = n - *lower_base; | |
1203 | return true; | |
1204 | } | |
1205 | ||
1206 | /* Insert the equivalence between ANCHOR and (REG + OFF) in mode MODE. */ | |
1207 | ||
1208 | static void | |
1209 | insert_const_anchor (HOST_WIDE_INT anchor, rtx reg, HOST_WIDE_INT offs, | |
ef4bddc2 | 1210 | machine_mode mode) |
2c5bfdf7 AN |
1211 | { |
1212 | struct table_elt *elt; | |
1213 | unsigned hash; | |
1214 | rtx anchor_exp; | |
1215 | rtx exp; | |
1216 | ||
1217 | anchor_exp = GEN_INT (anchor); | |
1218 | hash = HASH (anchor_exp, mode); | |
1219 | elt = lookup (anchor_exp, hash, mode); | |
1220 | if (!elt) | |
1221 | elt = insert (anchor_exp, NULL, hash, mode); | |
1222 | ||
0a81f074 | 1223 | exp = plus_constant (mode, reg, offs); |
2c5bfdf7 AN |
1224 | /* REG has just been inserted and the hash codes recomputed. */ |
1225 | mention_regs (exp); | |
1226 | hash = HASH (exp, mode); | |
1227 | ||
1228 | /* Use the cost of the register rather than the whole expression. When | |
1229 | looking up constant anchors we will further offset the corresponding | |
1230 | expression therefore it does not make sense to prefer REGs over | |
1231 | reg-immediate additions. Prefer instead the oldest expression. Also | |
1232 | don't prefer pseudos over hard regs so that we derive constants in | |
1233 | argument registers from other argument registers rather than from the | |
1234 | original pseudo that was used to synthesize the constant. */ | |
e548c9df | 1235 | insert_with_costs (exp, elt, hash, mode, COST (reg, mode), 1); |
2c5bfdf7 AN |
1236 | } |
1237 | ||
1238 | /* The constant CST is equivalent to the register REG. Create | |
1239 | equivalences between the two anchors of CST and the corresponding | |
1240 | register-offset expressions using REG. */ | |
1241 | ||
1242 | static void | |
ef4bddc2 | 1243 | insert_const_anchors (rtx reg, rtx cst, machine_mode mode) |
2c5bfdf7 AN |
1244 | { |
1245 | HOST_WIDE_INT lower_base, lower_offs, upper_base, upper_offs; | |
1246 | ||
1247 | if (!compute_const_anchors (cst, &lower_base, &lower_offs, | |
1248 | &upper_base, &upper_offs)) | |
1249 | return; | |
1250 | ||
1251 | /* Ignore anchors of value 0. Constants accessible from zero are | |
1252 | simple. */ | |
1253 | if (lower_base != 0) | |
1254 | insert_const_anchor (lower_base, reg, -lower_offs, mode); | |
1255 | ||
1256 | if (upper_base != 0) | |
1257 | insert_const_anchor (upper_base, reg, -upper_offs, mode); | |
1258 | } | |
1259 | ||
1260 | /* We need to express ANCHOR_ELT->exp + OFFS. Walk the equivalence list of | |
1261 | ANCHOR_ELT and see if offsetting any of the entries by OFFS would create a | |
1262 | valid expression. Return the cheapest and oldest of such expressions. In | |
1263 | *OLD, return how old the resulting expression is compared to the other | |
1264 | equivalent expressions. */ | |
1265 | ||
1266 | static rtx | |
1267 | find_reg_offset_for_const (struct table_elt *anchor_elt, HOST_WIDE_INT offs, | |
1268 | unsigned *old) | |
1269 | { | |
1270 | struct table_elt *elt; | |
1271 | unsigned idx; | |
1272 | struct table_elt *match_elt; | |
1273 | rtx match; | |
1274 | ||
1275 | /* Find the cheapest and *oldest* expression to maximize the chance of | |
1276 | reusing the same pseudo. */ | |
1277 | ||
1278 | match_elt = NULL; | |
1279 | match = NULL_RTX; | |
1280 | for (elt = anchor_elt->first_same_value, idx = 0; | |
1281 | elt; | |
1282 | elt = elt->next_same_value, idx++) | |
1283 | { | |
1284 | if (match_elt && CHEAPER (match_elt, elt)) | |
1285 | return match; | |
1286 | ||
1287 | if (REG_P (elt->exp) | |
1288 | || (GET_CODE (elt->exp) == PLUS | |
1289 | && REG_P (XEXP (elt->exp, 0)) | |
1290 | && GET_CODE (XEXP (elt->exp, 1)) == CONST_INT)) | |
1291 | { | |
1292 | rtx x; | |
1293 | ||
1294 | /* Ignore expressions that are no longer valid. */ | |
1295 | if (!REG_P (elt->exp) && !exp_equiv_p (elt->exp, elt->exp, 1, false)) | |
1296 | continue; | |
1297 | ||
0a81f074 | 1298 | x = plus_constant (GET_MODE (elt->exp), elt->exp, offs); |
2c5bfdf7 AN |
1299 | if (REG_P (x) |
1300 | || (GET_CODE (x) == PLUS | |
1301 | && IN_RANGE (INTVAL (XEXP (x, 1)), | |
1302 | -targetm.const_anchor, | |
1303 | targetm.const_anchor - 1))) | |
1304 | { | |
1305 | match = x; | |
1306 | match_elt = elt; | |
1307 | *old = idx; | |
1308 | } | |
1309 | } | |
1310 | } | |
1311 | ||
1312 | return match; | |
1313 | } | |
1314 | ||
1315 | /* Try to express the constant SRC_CONST using a register+offset expression | |
1316 | derived from a constant anchor. Return it if successful or NULL_RTX, | |
1317 | otherwise. */ | |
1318 | ||
1319 | static rtx | |
ef4bddc2 | 1320 | try_const_anchors (rtx src_const, machine_mode mode) |
2c5bfdf7 AN |
1321 | { |
1322 | struct table_elt *lower_elt, *upper_elt; | |
1323 | HOST_WIDE_INT lower_base, lower_offs, upper_base, upper_offs; | |
1324 | rtx lower_anchor_rtx, upper_anchor_rtx; | |
1325 | rtx lower_exp = NULL_RTX, upper_exp = NULL_RTX; | |
1326 | unsigned lower_old, upper_old; | |
1327 | ||
40dbb05c RS |
1328 | /* CONST_INT is used for CC modes, but we should leave those alone. */ |
1329 | if (GET_MODE_CLASS (mode) == MODE_CC) | |
1330 | return NULL_RTX; | |
1331 | ||
1332 | gcc_assert (SCALAR_INT_MODE_P (mode)); | |
2c5bfdf7 AN |
1333 | if (!compute_const_anchors (src_const, &lower_base, &lower_offs, |
1334 | &upper_base, &upper_offs)) | |
1335 | return NULL_RTX; | |
1336 | ||
1337 | lower_anchor_rtx = GEN_INT (lower_base); | |
1338 | upper_anchor_rtx = GEN_INT (upper_base); | |
1339 | lower_elt = lookup (lower_anchor_rtx, HASH (lower_anchor_rtx, mode), mode); | |
1340 | upper_elt = lookup (upper_anchor_rtx, HASH (upper_anchor_rtx, mode), mode); | |
1341 | ||
1342 | if (lower_elt) | |
1343 | lower_exp = find_reg_offset_for_const (lower_elt, lower_offs, &lower_old); | |
1344 | if (upper_elt) | |
1345 | upper_exp = find_reg_offset_for_const (upper_elt, upper_offs, &upper_old); | |
1346 | ||
1347 | if (!lower_exp) | |
1348 | return upper_exp; | |
1349 | if (!upper_exp) | |
1350 | return lower_exp; | |
1351 | ||
1352 | /* Return the older expression. */ | |
1353 | return (upper_old > lower_old ? upper_exp : lower_exp); | |
1354 | } | |
1355 | \f | |
7afe21cc RK |
1356 | /* Look in or update the hash table. */ |
1357 | ||
7afe21cc RK |
1358 | /* Remove table element ELT from use in the table. |
1359 | HASH is its hash code, made using the HASH macro. | |
1360 | It's an argument because often that is known in advance | |
1361 | and we save much time not recomputing it. */ | |
1362 | ||
1363 | static void | |
7080f735 | 1364 | remove_from_table (struct table_elt *elt, unsigned int hash) |
7afe21cc RK |
1365 | { |
1366 | if (elt == 0) | |
1367 | return; | |
1368 | ||
1369 | /* Mark this element as removed. See cse_insn. */ | |
1370 | elt->first_same_value = 0; | |
1371 | ||
1372 | /* Remove the table element from its equivalence class. */ | |
278a83b2 | 1373 | |
7afe21cc | 1374 | { |
b3694847 SS |
1375 | struct table_elt *prev = elt->prev_same_value; |
1376 | struct table_elt *next = elt->next_same_value; | |
7afe21cc | 1377 | |
278a83b2 KH |
1378 | if (next) |
1379 | next->prev_same_value = prev; | |
7afe21cc RK |
1380 | |
1381 | if (prev) | |
1382 | prev->next_same_value = next; | |
1383 | else | |
1384 | { | |
b3694847 | 1385 | struct table_elt *newfirst = next; |
7afe21cc RK |
1386 | while (next) |
1387 | { | |
1388 | next->first_same_value = newfirst; | |
1389 | next = next->next_same_value; | |
1390 | } | |
1391 | } | |
1392 | } | |
1393 | ||
1394 | /* Remove the table element from its hash bucket. */ | |
1395 | ||
1396 | { | |
b3694847 SS |
1397 | struct table_elt *prev = elt->prev_same_hash; |
1398 | struct table_elt *next = elt->next_same_hash; | |
7afe21cc | 1399 | |
278a83b2 KH |
1400 | if (next) |
1401 | next->prev_same_hash = prev; | |
7afe21cc RK |
1402 | |
1403 | if (prev) | |
1404 | prev->next_same_hash = next; | |
1405 | else if (table[hash] == elt) | |
1406 | table[hash] = next; | |
1407 | else | |
1408 | { | |
1409 | /* This entry is not in the proper hash bucket. This can happen | |
1410 | when two classes were merged by `merge_equiv_classes'. Search | |
1411 | for the hash bucket that it heads. This happens only very | |
1412 | rarely, so the cost is acceptable. */ | |
9b1549b8 | 1413 | for (hash = 0; hash < HASH_SIZE; hash++) |
7afe21cc RK |
1414 | if (table[hash] == elt) |
1415 | table[hash] = next; | |
1416 | } | |
1417 | } | |
1418 | ||
1419 | /* Remove the table element from its related-value circular chain. */ | |
1420 | ||
1421 | if (elt->related_value != 0 && elt->related_value != elt) | |
1422 | { | |
b3694847 | 1423 | struct table_elt *p = elt->related_value; |
770ae6cc | 1424 | |
7afe21cc RK |
1425 | while (p->related_value != elt) |
1426 | p = p->related_value; | |
1427 | p->related_value = elt->related_value; | |
1428 | if (p->related_value == p) | |
1429 | p->related_value = 0; | |
1430 | } | |
1431 | ||
9b1549b8 DM |
1432 | /* Now add it to the free element chain. */ |
1433 | elt->next_same_hash = free_element_chain; | |
1434 | free_element_chain = elt; | |
7afe21cc RK |
1435 | } |
1436 | ||
d556d181 EB |
1437 | /* Same as above, but X is a pseudo-register. */ |
1438 | ||
1439 | static void | |
1440 | remove_pseudo_from_table (rtx x, unsigned int hash) | |
1441 | { | |
1442 | struct table_elt *elt; | |
1443 | ||
1444 | /* Because a pseudo-register can be referenced in more than one | |
1445 | mode, we might have to remove more than one table entry. */ | |
1446 | while ((elt = lookup_for_remove (x, hash, VOIDmode))) | |
1447 | remove_from_table (elt, hash); | |
1448 | } | |
1449 | ||
7afe21cc RK |
1450 | /* Look up X in the hash table and return its table element, |
1451 | or 0 if X is not in the table. | |
1452 | ||
1453 | MODE is the machine-mode of X, or if X is an integer constant | |
1454 | with VOIDmode then MODE is the mode with which X will be used. | |
1455 | ||
1456 | Here we are satisfied to find an expression whose tree structure | |
1457 | looks like X. */ | |
1458 | ||
1459 | static struct table_elt * | |
ef4bddc2 | 1460 | lookup (rtx x, unsigned int hash, machine_mode mode) |
7afe21cc | 1461 | { |
b3694847 | 1462 | struct table_elt *p; |
7afe21cc RK |
1463 | |
1464 | for (p = table[hash]; p; p = p->next_same_hash) | |
f8cfc6aa | 1465 | if (mode == p->mode && ((x == p->exp && REG_P (x)) |
0516f6fe | 1466 | || exp_equiv_p (x, p->exp, !REG_P (x), false))) |
7afe21cc RK |
1467 | return p; |
1468 | ||
1469 | return 0; | |
1470 | } | |
1471 | ||
1472 | /* Like `lookup' but don't care whether the table element uses invalid regs. | |
1473 | Also ignore discrepancies in the machine mode of a register. */ | |
1474 | ||
1475 | static struct table_elt * | |
ef4bddc2 | 1476 | lookup_for_remove (rtx x, unsigned int hash, machine_mode mode) |
7afe21cc | 1477 | { |
b3694847 | 1478 | struct table_elt *p; |
7afe21cc | 1479 | |
f8cfc6aa | 1480 | if (REG_P (x)) |
7afe21cc | 1481 | { |
770ae6cc RK |
1482 | unsigned int regno = REGNO (x); |
1483 | ||
7afe21cc RK |
1484 | /* Don't check the machine mode when comparing registers; |
1485 | invalidating (REG:SI 0) also invalidates (REG:DF 0). */ | |
1486 | for (p = table[hash]; p; p = p->next_same_hash) | |
f8cfc6aa | 1487 | if (REG_P (p->exp) |
7afe21cc RK |
1488 | && REGNO (p->exp) == regno) |
1489 | return p; | |
1490 | } | |
1491 | else | |
1492 | { | |
1493 | for (p = table[hash]; p; p = p->next_same_hash) | |
0516f6fe SB |
1494 | if (mode == p->mode |
1495 | && (x == p->exp || exp_equiv_p (x, p->exp, 0, false))) | |
7afe21cc RK |
1496 | return p; |
1497 | } | |
1498 | ||
1499 | return 0; | |
1500 | } | |
1501 | ||
1502 | /* Look for an expression equivalent to X and with code CODE. | |
1503 | If one is found, return that expression. */ | |
1504 | ||
1505 | static rtx | |
7080f735 | 1506 | lookup_as_function (rtx x, enum rtx_code code) |
7afe21cc | 1507 | { |
b3694847 | 1508 | struct table_elt *p |
0516f6fe | 1509 | = lookup (x, SAFE_HASH (x, VOIDmode), GET_MODE (x)); |
770ae6cc | 1510 | |
7afe21cc RK |
1511 | if (p == 0) |
1512 | return 0; | |
1513 | ||
1514 | for (p = p->first_same_value; p; p = p->next_same_value) | |
770ae6cc RK |
1515 | if (GET_CODE (p->exp) == code |
1516 | /* Make sure this is a valid entry in the table. */ | |
0516f6fe | 1517 | && exp_equiv_p (p->exp, p->exp, 1, false)) |
770ae6cc | 1518 | return p->exp; |
278a83b2 | 1519 | |
7afe21cc RK |
1520 | return 0; |
1521 | } | |
1522 | ||
2c5bfdf7 AN |
1523 | /* Insert X in the hash table, assuming HASH is its hash code and |
1524 | CLASSP is an element of the class it should go in (or 0 if a new | |
1525 | class should be made). COST is the code of X and reg_cost is the | |
1526 | cost of registers in X. It is inserted at the proper position to | |
1527 | keep the class in the order cheapest first. | |
7afe21cc RK |
1528 | |
1529 | MODE is the machine-mode of X, or if X is an integer constant | |
1530 | with VOIDmode then MODE is the mode with which X will be used. | |
1531 | ||
1532 | For elements of equal cheapness, the most recent one | |
1533 | goes in front, except that the first element in the list | |
1534 | remains first unless a cheaper element is added. The order of | |
1535 | pseudo-registers does not matter, as canon_reg will be called to | |
830a38ee | 1536 | find the cheapest when a register is retrieved from the table. |
7afe21cc RK |
1537 | |
1538 | The in_memory field in the hash table element is set to 0. | |
1539 | The caller must set it nonzero if appropriate. | |
1540 | ||
1541 | You should call insert_regs (X, CLASSP, MODIFY) before calling here, | |
1542 | and if insert_regs returns a nonzero value | |
1543 | you must then recompute its hash code before calling here. | |
1544 | ||
1545 | If necessary, update table showing constant values of quantities. */ | |
1546 | ||
7afe21cc | 1547 | static struct table_elt * |
2c5bfdf7 | 1548 | insert_with_costs (rtx x, struct table_elt *classp, unsigned int hash, |
ef4bddc2 | 1549 | machine_mode mode, int cost, int reg_cost) |
7afe21cc | 1550 | { |
b3694847 | 1551 | struct table_elt *elt; |
7afe21cc RK |
1552 | |
1553 | /* If X is a register and we haven't made a quantity for it, | |
1554 | something is wrong. */ | |
341c100f | 1555 | gcc_assert (!REG_P (x) || REGNO_QTY_VALID_P (REGNO (x))); |
7afe21cc RK |
1556 | |
1557 | /* If X is a hard register, show it is being put in the table. */ | |
f8cfc6aa | 1558 | if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER) |
09e18274 | 1559 | add_to_hard_reg_set (&hard_regs_in_table, GET_MODE (x), REGNO (x)); |
7afe21cc | 1560 | |
7afe21cc RK |
1561 | /* Put an element for X into the right hash bucket. */ |
1562 | ||
9b1549b8 DM |
1563 | elt = free_element_chain; |
1564 | if (elt) | |
770ae6cc | 1565 | free_element_chain = elt->next_same_hash; |
9b1549b8 | 1566 | else |
5ed6ace5 | 1567 | elt = XNEW (struct table_elt); |
9b1549b8 | 1568 | |
7afe21cc | 1569 | elt->exp = x; |
db048faf | 1570 | elt->canon_exp = NULL_RTX; |
2c5bfdf7 AN |
1571 | elt->cost = cost; |
1572 | elt->regcost = reg_cost; | |
7afe21cc RK |
1573 | elt->next_same_value = 0; |
1574 | elt->prev_same_value = 0; | |
1575 | elt->next_same_hash = table[hash]; | |
1576 | elt->prev_same_hash = 0; | |
1577 | elt->related_value = 0; | |
1578 | elt->in_memory = 0; | |
1579 | elt->mode = mode; | |
389fdba0 | 1580 | elt->is_const = (CONSTANT_P (x) || fixed_base_plus_p (x)); |
7afe21cc RK |
1581 | |
1582 | if (table[hash]) | |
1583 | table[hash]->prev_same_hash = elt; | |
1584 | table[hash] = elt; | |
1585 | ||
1586 | /* Put it into the proper value-class. */ | |
1587 | if (classp) | |
1588 | { | |
1589 | classp = classp->first_same_value; | |
1590 | if (CHEAPER (elt, classp)) | |
f9da5064 | 1591 | /* Insert at the head of the class. */ |
7afe21cc | 1592 | { |
b3694847 | 1593 | struct table_elt *p; |
7afe21cc RK |
1594 | elt->next_same_value = classp; |
1595 | classp->prev_same_value = elt; | |
1596 | elt->first_same_value = elt; | |
1597 | ||
1598 | for (p = classp; p; p = p->next_same_value) | |
1599 | p->first_same_value = elt; | |
1600 | } | |
1601 | else | |
1602 | { | |
1603 | /* Insert not at head of the class. */ | |
1604 | /* Put it after the last element cheaper than X. */ | |
b3694847 | 1605 | struct table_elt *p, *next; |
770ae6cc | 1606 | |
e84a58ff EB |
1607 | for (p = classp; |
1608 | (next = p->next_same_value) && CHEAPER (next, elt); | |
1609 | p = next) | |
1610 | ; | |
770ae6cc | 1611 | |
7afe21cc RK |
1612 | /* Put it after P and before NEXT. */ |
1613 | elt->next_same_value = next; | |
1614 | if (next) | |
1615 | next->prev_same_value = elt; | |
770ae6cc | 1616 | |
7afe21cc RK |
1617 | elt->prev_same_value = p; |
1618 | p->next_same_value = elt; | |
1619 | elt->first_same_value = classp; | |
1620 | } | |
1621 | } | |
1622 | else | |
1623 | elt->first_same_value = elt; | |
1624 | ||
1625 | /* If this is a constant being set equivalent to a register or a register | |
1626 | being set equivalent to a constant, note the constant equivalence. | |
1627 | ||
1628 | If this is a constant, it cannot be equivalent to a different constant, | |
1629 | and a constant is the only thing that can be cheaper than a register. So | |
1630 | we know the register is the head of the class (before the constant was | |
1631 | inserted). | |
1632 | ||
1633 | If this is a register that is not already known equivalent to a | |
1634 | constant, we must check the entire class. | |
1635 | ||
1636 | If this is a register that is already known equivalent to an insn, | |
1bb98cec | 1637 | update the qtys `const_insn' to show that `this_insn' is the latest |
7afe21cc RK |
1638 | insn making that quantity equivalent to the constant. */ |
1639 | ||
f8cfc6aa JQ |
1640 | if (elt->is_const && classp && REG_P (classp->exp) |
1641 | && !REG_P (x)) | |
7afe21cc | 1642 | { |
1bb98cec DM |
1643 | int exp_q = REG_QTY (REGNO (classp->exp)); |
1644 | struct qty_table_elem *exp_ent = &qty_table[exp_q]; | |
1645 | ||
4de249d9 | 1646 | exp_ent->const_rtx = gen_lowpart (exp_ent->mode, x); |
1bb98cec | 1647 | exp_ent->const_insn = this_insn; |
7afe21cc RK |
1648 | } |
1649 | ||
f8cfc6aa | 1650 | else if (REG_P (x) |
1bb98cec DM |
1651 | && classp |
1652 | && ! qty_table[REG_QTY (REGNO (x))].const_rtx | |
f353588a | 1653 | && ! elt->is_const) |
7afe21cc | 1654 | { |
b3694847 | 1655 | struct table_elt *p; |
7afe21cc RK |
1656 | |
1657 | for (p = classp; p != 0; p = p->next_same_value) | |
1658 | { | |
f8cfc6aa | 1659 | if (p->is_const && !REG_P (p->exp)) |
7afe21cc | 1660 | { |
1bb98cec DM |
1661 | int x_q = REG_QTY (REGNO (x)); |
1662 | struct qty_table_elem *x_ent = &qty_table[x_q]; | |
1663 | ||
770ae6cc | 1664 | x_ent->const_rtx |
4de249d9 | 1665 | = gen_lowpart (GET_MODE (x), p->exp); |
1bb98cec | 1666 | x_ent->const_insn = this_insn; |
7afe21cc RK |
1667 | break; |
1668 | } | |
1669 | } | |
1670 | } | |
1671 | ||
f8cfc6aa | 1672 | else if (REG_P (x) |
1bb98cec DM |
1673 | && qty_table[REG_QTY (REGNO (x))].const_rtx |
1674 | && GET_MODE (x) == qty_table[REG_QTY (REGNO (x))].mode) | |
1675 | qty_table[REG_QTY (REGNO (x))].const_insn = this_insn; | |
7afe21cc RK |
1676 | |
1677 | /* If this is a constant with symbolic value, | |
1678 | and it has a term with an explicit integer value, | |
1679 | link it up with related expressions. */ | |
1680 | if (GET_CODE (x) == CONST) | |
1681 | { | |
1682 | rtx subexp = get_related_value (x); | |
2197a88a | 1683 | unsigned subhash; |
7afe21cc RK |
1684 | struct table_elt *subelt, *subelt_prev; |
1685 | ||
1686 | if (subexp != 0) | |
1687 | { | |
1688 | /* Get the integer-free subexpression in the hash table. */ | |
0516f6fe | 1689 | subhash = SAFE_HASH (subexp, mode); |
7afe21cc RK |
1690 | subelt = lookup (subexp, subhash, mode); |
1691 | if (subelt == 0) | |
9714cf43 | 1692 | subelt = insert (subexp, NULL, subhash, mode); |
7afe21cc RK |
1693 | /* Initialize SUBELT's circular chain if it has none. */ |
1694 | if (subelt->related_value == 0) | |
1695 | subelt->related_value = subelt; | |
1696 | /* Find the element in the circular chain that precedes SUBELT. */ | |
1697 | subelt_prev = subelt; | |
1698 | while (subelt_prev->related_value != subelt) | |
1699 | subelt_prev = subelt_prev->related_value; | |
1700 | /* Put new ELT into SUBELT's circular chain just before SUBELT. | |
1701 | This way the element that follows SUBELT is the oldest one. */ | |
1702 | elt->related_value = subelt_prev->related_value; | |
1703 | subelt_prev->related_value = elt; | |
1704 | } | |
1705 | } | |
1706 | ||
1707 | return elt; | |
1708 | } | |
2c5bfdf7 AN |
1709 | |
1710 | /* Wrap insert_with_costs by passing the default costs. */ | |
1711 | ||
1712 | static struct table_elt * | |
1713 | insert (rtx x, struct table_elt *classp, unsigned int hash, | |
ef4bddc2 | 1714 | machine_mode mode) |
2c5bfdf7 | 1715 | { |
e548c9df AM |
1716 | return insert_with_costs (x, classp, hash, mode, |
1717 | COST (x, mode), approx_reg_cost (x)); | |
2c5bfdf7 AN |
1718 | } |
1719 | ||
7afe21cc RK |
1720 | \f |
1721 | /* Given two equivalence classes, CLASS1 and CLASS2, put all the entries from | |
1722 | CLASS2 into CLASS1. This is done when we have reached an insn which makes | |
1723 | the two classes equivalent. | |
1724 | ||
1725 | CLASS1 will be the surviving class; CLASS2 should not be used after this | |
1726 | call. | |
1727 | ||
1728 | Any invalid entries in CLASS2 will not be copied. */ | |
1729 | ||
1730 | static void | |
7080f735 | 1731 | merge_equiv_classes (struct table_elt *class1, struct table_elt *class2) |
7afe21cc | 1732 | { |
32e9fa48 | 1733 | struct table_elt *elt, *next, *new_elt; |
7afe21cc RK |
1734 | |
1735 | /* Ensure we start with the head of the classes. */ | |
1736 | class1 = class1->first_same_value; | |
1737 | class2 = class2->first_same_value; | |
1738 | ||
1739 | /* If they were already equal, forget it. */ | |
1740 | if (class1 == class2) | |
1741 | return; | |
1742 | ||
1743 | for (elt = class2; elt; elt = next) | |
1744 | { | |
770ae6cc | 1745 | unsigned int hash; |
7afe21cc | 1746 | rtx exp = elt->exp; |
ef4bddc2 | 1747 | machine_mode mode = elt->mode; |
7afe21cc RK |
1748 | |
1749 | next = elt->next_same_value; | |
1750 | ||
1751 | /* Remove old entry, make a new one in CLASS1's class. | |
1752 | Don't do this for invalid entries as we cannot find their | |
0f41302f | 1753 | hash code (it also isn't necessary). */ |
0516f6fe | 1754 | if (REG_P (exp) || exp_equiv_p (exp, exp, 1, false)) |
7afe21cc | 1755 | { |
a90fc8e0 RH |
1756 | bool need_rehash = false; |
1757 | ||
7afe21cc | 1758 | hash_arg_in_memory = 0; |
7afe21cc | 1759 | hash = HASH (exp, mode); |
278a83b2 | 1760 | |
f8cfc6aa | 1761 | if (REG_P (exp)) |
a90fc8e0 | 1762 | { |
08a69267 | 1763 | need_rehash = REGNO_QTY_VALID_P (REGNO (exp)); |
a90fc8e0 RH |
1764 | delete_reg_equiv (REGNO (exp)); |
1765 | } | |
278a83b2 | 1766 | |
d556d181 EB |
1767 | if (REG_P (exp) && REGNO (exp) >= FIRST_PSEUDO_REGISTER) |
1768 | remove_pseudo_from_table (exp, hash); | |
1769 | else | |
1770 | remove_from_table (elt, hash); | |
7afe21cc | 1771 | |
a90fc8e0 | 1772 | if (insert_regs (exp, class1, 0) || need_rehash) |
8ae2b8f6 JW |
1773 | { |
1774 | rehash_using_reg (exp); | |
1775 | hash = HASH (exp, mode); | |
1776 | } | |
32e9fa48 KG |
1777 | new_elt = insert (exp, class1, hash, mode); |
1778 | new_elt->in_memory = hash_arg_in_memory; | |
6c4d60f8 JJ |
1779 | if (GET_CODE (exp) == ASM_OPERANDS && elt->cost == MAX_COST) |
1780 | new_elt->cost = MAX_COST; | |
7afe21cc RK |
1781 | } |
1782 | } | |
1783 | } | |
1784 | \f | |
01e752d3 JL |
1785 | /* Flush the entire hash table. */ |
1786 | ||
1787 | static void | |
7080f735 | 1788 | flush_hash_table (void) |
01e752d3 JL |
1789 | { |
1790 | int i; | |
1791 | struct table_elt *p; | |
1792 | ||
9b1549b8 | 1793 | for (i = 0; i < HASH_SIZE; i++) |
01e752d3 JL |
1794 | for (p = table[i]; p; p = table[i]) |
1795 | { | |
1796 | /* Note that invalidate can remove elements | |
1797 | after P in the current hash chain. */ | |
f8cfc6aa | 1798 | if (REG_P (p->exp)) |
524e3576 | 1799 | invalidate (p->exp, VOIDmode); |
01e752d3 JL |
1800 | else |
1801 | remove_from_table (p, i); | |
1802 | } | |
1803 | } | |
14a774a9 | 1804 | \f |
c992c066 RS |
1805 | /* Check whether an anti dependence exists between X and EXP. MODE and |
1806 | ADDR are as for canon_anti_dependence. */ | |
be8ac49a | 1807 | |
c992c066 | 1808 | static bool |
ef4bddc2 | 1809 | check_dependence (const_rtx x, rtx exp, machine_mode mode, rtx addr) |
2ce6dc2f | 1810 | { |
c992c066 RS |
1811 | subrtx_iterator::array_type array; |
1812 | FOR_EACH_SUBRTX (iter, array, x, NONCONST) | |
1813 | { | |
1814 | const_rtx x = *iter; | |
1815 | if (MEM_P (x) && canon_anti_dependence (x, true, exp, mode, addr)) | |
1816 | return true; | |
1817 | } | |
1818 | return false; | |
2ce6dc2f JH |
1819 | } |
1820 | \f | |
14a774a9 RK |
1821 | /* Remove from the hash table, or mark as invalid, all expressions whose |
1822 | values could be altered by storing in X. X is a register, a subreg, or | |
1823 | a memory reference with nonvarying address (because, when a memory | |
1824 | reference with a varying address is stored in, all memory references are | |
1825 | removed by invalidate_memory so specific invalidation is superfluous). | |
1826 | FULL_MODE, if not VOIDmode, indicates that this much should be | |
1827 | invalidated instead of just the amount indicated by the mode of X. This | |
1828 | is only used for bitfield stores into memory. | |
1829 | ||
1830 | A nonvarying address may be just a register or just a symbol reference, | |
1831 | or it may be either of those plus a numeric offset. */ | |
7afe21cc RK |
1832 | |
1833 | static void | |
ef4bddc2 | 1834 | invalidate (rtx x, machine_mode full_mode) |
7afe21cc | 1835 | { |
b3694847 SS |
1836 | int i; |
1837 | struct table_elt *p; | |
9ddb66ca | 1838 | rtx addr; |
7afe21cc | 1839 | |
14a774a9 | 1840 | switch (GET_CODE (x)) |
7afe21cc | 1841 | { |
14a774a9 RK |
1842 | case REG: |
1843 | { | |
1844 | /* If X is a register, dependencies on its contents are recorded | |
1845 | through the qty number mechanism. Just change the qty number of | |
1846 | the register, mark it as invalid for expressions that refer to it, | |
1847 | and remove it itself. */ | |
770ae6cc RK |
1848 | unsigned int regno = REGNO (x); |
1849 | unsigned int hash = HASH (x, GET_MODE (x)); | |
7afe21cc | 1850 | |
14a774a9 RK |
1851 | /* Remove REGNO from any quantity list it might be on and indicate |
1852 | that its value might have changed. If it is a pseudo, remove its | |
1853 | entry from the hash table. | |
7afe21cc | 1854 | |
14a774a9 RK |
1855 | For a hard register, we do the first two actions above for any |
1856 | additional hard registers corresponding to X. Then, if any of these | |
1857 | registers are in the table, we must remove any REG entries that | |
1858 | overlap these registers. */ | |
7afe21cc | 1859 | |
14a774a9 RK |
1860 | delete_reg_equiv (regno); |
1861 | REG_TICK (regno)++; | |
46081bb3 | 1862 | SUBREG_TICKED (regno) = -1; |
85e4d983 | 1863 | |
14a774a9 | 1864 | if (regno >= FIRST_PSEUDO_REGISTER) |
d556d181 | 1865 | remove_pseudo_from_table (x, hash); |
14a774a9 RK |
1866 | else |
1867 | { | |
1868 | HOST_WIDE_INT in_table | |
1869 | = TEST_HARD_REG_BIT (hard_regs_in_table, regno); | |
72d19505 | 1870 | unsigned int endregno = END_REGNO (x); |
770ae6cc | 1871 | unsigned int tregno, tendregno, rn; |
b3694847 | 1872 | struct table_elt *p, *next; |
7afe21cc | 1873 | |
14a774a9 | 1874 | CLEAR_HARD_REG_BIT (hard_regs_in_table, regno); |
7afe21cc | 1875 | |
770ae6cc | 1876 | for (rn = regno + 1; rn < endregno; rn++) |
14a774a9 | 1877 | { |
770ae6cc RK |
1878 | in_table |= TEST_HARD_REG_BIT (hard_regs_in_table, rn); |
1879 | CLEAR_HARD_REG_BIT (hard_regs_in_table, rn); | |
1880 | delete_reg_equiv (rn); | |
1881 | REG_TICK (rn)++; | |
46081bb3 | 1882 | SUBREG_TICKED (rn) = -1; |
14a774a9 | 1883 | } |
7afe21cc | 1884 | |
14a774a9 | 1885 | if (in_table) |
9b1549b8 | 1886 | for (hash = 0; hash < HASH_SIZE; hash++) |
14a774a9 RK |
1887 | for (p = table[hash]; p; p = next) |
1888 | { | |
1889 | next = p->next_same_hash; | |
7afe21cc | 1890 | |
f8cfc6aa | 1891 | if (!REG_P (p->exp) |
278a83b2 KH |
1892 | || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) |
1893 | continue; | |
1894 | ||
14a774a9 | 1895 | tregno = REGNO (p->exp); |
72d19505 | 1896 | tendregno = END_REGNO (p->exp); |
14a774a9 RK |
1897 | if (tendregno > regno && tregno < endregno) |
1898 | remove_from_table (p, hash); | |
1899 | } | |
1900 | } | |
1901 | } | |
7afe21cc | 1902 | return; |
7afe21cc | 1903 | |
14a774a9 | 1904 | case SUBREG: |
bb4034b3 | 1905 | invalidate (SUBREG_REG (x), VOIDmode); |
7afe21cc | 1906 | return; |
aac5cc16 | 1907 | |
14a774a9 | 1908 | case PARALLEL: |
278a83b2 | 1909 | for (i = XVECLEN (x, 0) - 1; i >= 0; --i) |
aac5cc16 RH |
1910 | invalidate (XVECEXP (x, 0, i), VOIDmode); |
1911 | return; | |
aac5cc16 | 1912 | |
14a774a9 RK |
1913 | case EXPR_LIST: |
1914 | /* This is part of a disjoint return value; extract the location in | |
1915 | question ignoring the offset. */ | |
aac5cc16 RH |
1916 | invalidate (XEXP (x, 0), VOIDmode); |
1917 | return; | |
7afe21cc | 1918 | |
14a774a9 | 1919 | case MEM: |
9ddb66ca | 1920 | addr = canon_rtx (get_addr (XEXP (x, 0))); |
db048faf MM |
1921 | /* Calculate the canonical version of X here so that |
1922 | true_dependence doesn't generate new RTL for X on each call. */ | |
1923 | x = canon_rtx (x); | |
1924 | ||
14a774a9 RK |
1925 | /* Remove all hash table elements that refer to overlapping pieces of |
1926 | memory. */ | |
1927 | if (full_mode == VOIDmode) | |
1928 | full_mode = GET_MODE (x); | |
bb4034b3 | 1929 | |
9b1549b8 | 1930 | for (i = 0; i < HASH_SIZE; i++) |
7afe21cc | 1931 | { |
b3694847 | 1932 | struct table_elt *next; |
14a774a9 RK |
1933 | |
1934 | for (p = table[i]; p; p = next) | |
1935 | { | |
1936 | next = p->next_same_hash; | |
db048faf MM |
1937 | if (p->in_memory) |
1938 | { | |
2ce6dc2f JH |
1939 | /* Just canonicalize the expression once; |
1940 | otherwise each time we call invalidate | |
1941 | true_dependence will canonicalize the | |
1942 | expression again. */ | |
1943 | if (!p->canon_exp) | |
1944 | p->canon_exp = canon_rtx (p->exp); | |
c992c066 | 1945 | if (check_dependence (p->canon_exp, x, full_mode, addr)) |
db048faf | 1946 | remove_from_table (p, i); |
db048faf | 1947 | } |
14a774a9 | 1948 | } |
7afe21cc | 1949 | } |
14a774a9 RK |
1950 | return; |
1951 | ||
1952 | default: | |
341c100f | 1953 | gcc_unreachable (); |
7afe21cc RK |
1954 | } |
1955 | } | |
2a1d78d8 JJ |
1956 | |
1957 | /* Invalidate DEST. Used when DEST is not going to be added | |
1958 | into the hash table for some reason, e.g. do_not_record | |
1959 | flagged on it. */ | |
1960 | ||
1961 | static void | |
1962 | invalidate_dest (rtx dest) | |
1963 | { | |
1964 | if (REG_P (dest) | |
1965 | || GET_CODE (dest) == SUBREG | |
1966 | || MEM_P (dest)) | |
1967 | invalidate (dest, VOIDmode); | |
1968 | else if (GET_CODE (dest) == STRICT_LOW_PART | |
1969 | || GET_CODE (dest) == ZERO_EXTRACT) | |
1970 | invalidate (XEXP (dest, 0), GET_MODE (dest)); | |
1971 | } | |
14a774a9 | 1972 | \f |
7afe21cc RK |
1973 | /* Remove all expressions that refer to register REGNO, |
1974 | since they are already invalid, and we are about to | |
1975 | mark that register valid again and don't want the old | |
1976 | expressions to reappear as valid. */ | |
1977 | ||
1978 | static void | |
7080f735 | 1979 | remove_invalid_refs (unsigned int regno) |
7afe21cc | 1980 | { |
770ae6cc RK |
1981 | unsigned int i; |
1982 | struct table_elt *p, *next; | |
7afe21cc | 1983 | |
9b1549b8 | 1984 | for (i = 0; i < HASH_SIZE; i++) |
7afe21cc RK |
1985 | for (p = table[i]; p; p = next) |
1986 | { | |
1987 | next = p->next_same_hash; | |
c9bd6bcd | 1988 | if (!REG_P (p->exp) && refers_to_regno_p (regno, p->exp)) |
7afe21cc RK |
1989 | remove_from_table (p, i); |
1990 | } | |
1991 | } | |
34c73909 | 1992 | |
ddef6bc7 JJ |
1993 | /* Likewise for a subreg with subreg_reg REGNO, subreg_byte OFFSET, |
1994 | and mode MODE. */ | |
34c73909 | 1995 | static void |
7080f735 | 1996 | remove_invalid_subreg_refs (unsigned int regno, unsigned int offset, |
ef4bddc2 | 1997 | machine_mode mode) |
34c73909 | 1998 | { |
770ae6cc RK |
1999 | unsigned int i; |
2000 | struct table_elt *p, *next; | |
ddef6bc7 | 2001 | unsigned int end = offset + (GET_MODE_SIZE (mode) - 1); |
34c73909 | 2002 | |
9b1549b8 | 2003 | for (i = 0; i < HASH_SIZE; i++) |
34c73909 R |
2004 | for (p = table[i]; p; p = next) |
2005 | { | |
ddef6bc7 | 2006 | rtx exp = p->exp; |
34c73909 | 2007 | next = p->next_same_hash; |
278a83b2 | 2008 | |
f8cfc6aa | 2009 | if (!REG_P (exp) |
34c73909 | 2010 | && (GET_CODE (exp) != SUBREG |
f8cfc6aa | 2011 | || !REG_P (SUBREG_REG (exp)) |
34c73909 | 2012 | || REGNO (SUBREG_REG (exp)) != regno |
ddef6bc7 JJ |
2013 | || (((SUBREG_BYTE (exp) |
2014 | + (GET_MODE_SIZE (GET_MODE (exp)) - 1)) >= offset) | |
2015 | && SUBREG_BYTE (exp) <= end)) | |
c9bd6bcd | 2016 | && refers_to_regno_p (regno, p->exp)) |
34c73909 R |
2017 | remove_from_table (p, i); |
2018 | } | |
2019 | } | |
7afe21cc RK |
2020 | \f |
2021 | /* Recompute the hash codes of any valid entries in the hash table that | |
2022 | reference X, if X is a register, or SUBREG_REG (X) if X is a SUBREG. | |
2023 | ||
2024 | This is called when we make a jump equivalence. */ | |
2025 | ||
2026 | static void | |
7080f735 | 2027 | rehash_using_reg (rtx x) |
7afe21cc | 2028 | { |
973838fd | 2029 | unsigned int i; |
7afe21cc | 2030 | struct table_elt *p, *next; |
2197a88a | 2031 | unsigned hash; |
7afe21cc RK |
2032 | |
2033 | if (GET_CODE (x) == SUBREG) | |
2034 | x = SUBREG_REG (x); | |
2035 | ||
2036 | /* If X is not a register or if the register is known not to be in any | |
2037 | valid entries in the table, we have no work to do. */ | |
2038 | ||
f8cfc6aa | 2039 | if (!REG_P (x) |
30f72379 MM |
2040 | || REG_IN_TABLE (REGNO (x)) < 0 |
2041 | || REG_IN_TABLE (REGNO (x)) != REG_TICK (REGNO (x))) | |
7afe21cc RK |
2042 | return; |
2043 | ||
2044 | /* Scan all hash chains looking for valid entries that mention X. | |
a90fc8e0 | 2045 | If we find one and it is in the wrong hash chain, move it. */ |
7afe21cc | 2046 | |
9b1549b8 | 2047 | for (i = 0; i < HASH_SIZE; i++) |
7afe21cc RK |
2048 | for (p = table[i]; p; p = next) |
2049 | { | |
2050 | next = p->next_same_hash; | |
a90fc8e0 | 2051 | if (reg_mentioned_p (x, p->exp) |
0516f6fe SB |
2052 | && exp_equiv_p (p->exp, p->exp, 1, false) |
2053 | && i != (hash = SAFE_HASH (p->exp, p->mode))) | |
7afe21cc RK |
2054 | { |
2055 | if (p->next_same_hash) | |
2056 | p->next_same_hash->prev_same_hash = p->prev_same_hash; | |
2057 | ||
2058 | if (p->prev_same_hash) | |
2059 | p->prev_same_hash->next_same_hash = p->next_same_hash; | |
2060 | else | |
2061 | table[i] = p->next_same_hash; | |
2062 | ||
2063 | p->next_same_hash = table[hash]; | |
2064 | p->prev_same_hash = 0; | |
2065 | if (table[hash]) | |
2066 | table[hash]->prev_same_hash = p; | |
2067 | table[hash] = p; | |
2068 | } | |
2069 | } | |
2070 | } | |
2071 | \f | |
7afe21cc RK |
2072 | /* Remove from the hash table any expression that is a call-clobbered |
2073 | register. Also update their TICK values. */ | |
2074 | ||
2075 | static void | |
7080f735 | 2076 | invalidate_for_call (void) |
7afe21cc | 2077 | { |
770ae6cc RK |
2078 | unsigned int regno, endregno; |
2079 | unsigned int i; | |
2197a88a | 2080 | unsigned hash; |
7afe21cc RK |
2081 | struct table_elt *p, *next; |
2082 | int in_table = 0; | |
c7fb4c7a | 2083 | hard_reg_set_iterator hrsi; |
7afe21cc RK |
2084 | |
2085 | /* Go through all the hard registers. For each that is clobbered in | |
2086 | a CALL_INSN, remove the register from quantity chains and update | |
2087 | reg_tick if defined. Also see if any of these registers is currently | |
2088 | in the table. */ | |
c7fb4c7a SB |
2089 | EXECUTE_IF_SET_IN_HARD_REG_SET (regs_invalidated_by_call, 0, regno, hrsi) |
2090 | { | |
2091 | delete_reg_equiv (regno); | |
2092 | if (REG_TICK (regno) >= 0) | |
2093 | { | |
2094 | REG_TICK (regno)++; | |
2095 | SUBREG_TICKED (regno) = -1; | |
2096 | } | |
2097 | in_table |= (TEST_HARD_REG_BIT (hard_regs_in_table, regno) != 0); | |
2098 | } | |
7afe21cc RK |
2099 | |
2100 | /* In the case where we have no call-clobbered hard registers in the | |
2101 | table, we are done. Otherwise, scan the table and remove any | |
2102 | entry that overlaps a call-clobbered register. */ | |
2103 | ||
2104 | if (in_table) | |
9b1549b8 | 2105 | for (hash = 0; hash < HASH_SIZE; hash++) |
7afe21cc RK |
2106 | for (p = table[hash]; p; p = next) |
2107 | { | |
2108 | next = p->next_same_hash; | |
2109 | ||
f8cfc6aa | 2110 | if (!REG_P (p->exp) |
7afe21cc RK |
2111 | || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) |
2112 | continue; | |
2113 | ||
2114 | regno = REGNO (p->exp); | |
72d19505 | 2115 | endregno = END_REGNO (p->exp); |
7afe21cc RK |
2116 | |
2117 | for (i = regno; i < endregno; i++) | |
2118 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)) | |
2119 | { | |
2120 | remove_from_table (p, hash); | |
2121 | break; | |
2122 | } | |
2123 | } | |
2124 | } | |
2125 | \f | |
2126 | /* Given an expression X of type CONST, | |
2127 | and ELT which is its table entry (or 0 if it | |
2128 | is not in the hash table), | |
2129 | return an alternate expression for X as a register plus integer. | |
2130 | If none can be found, return 0. */ | |
2131 | ||
2132 | static rtx | |
7080f735 | 2133 | use_related_value (rtx x, struct table_elt *elt) |
7afe21cc | 2134 | { |
b3694847 SS |
2135 | struct table_elt *relt = 0; |
2136 | struct table_elt *p, *q; | |
906c4e36 | 2137 | HOST_WIDE_INT offset; |
7afe21cc RK |
2138 | |
2139 | /* First, is there anything related known? | |
2140 | If we have a table element, we can tell from that. | |
2141 | Otherwise, must look it up. */ | |
2142 | ||
2143 | if (elt != 0 && elt->related_value != 0) | |
2144 | relt = elt; | |
2145 | else if (elt == 0 && GET_CODE (x) == CONST) | |
2146 | { | |
2147 | rtx subexp = get_related_value (x); | |
2148 | if (subexp != 0) | |
2149 | relt = lookup (subexp, | |
0516f6fe | 2150 | SAFE_HASH (subexp, GET_MODE (subexp)), |
7afe21cc RK |
2151 | GET_MODE (subexp)); |
2152 | } | |
2153 | ||
2154 | if (relt == 0) | |
2155 | return 0; | |
2156 | ||
2157 | /* Search all related table entries for one that has an | |
2158 | equivalent register. */ | |
2159 | ||
2160 | p = relt; | |
2161 | while (1) | |
2162 | { | |
2163 | /* This loop is strange in that it is executed in two different cases. | |
2164 | The first is when X is already in the table. Then it is searching | |
2165 | the RELATED_VALUE list of X's class (RELT). The second case is when | |
2166 | X is not in the table. Then RELT points to a class for the related | |
2167 | value. | |
2168 | ||
2169 | Ensure that, whatever case we are in, that we ignore classes that have | |
2170 | the same value as X. */ | |
2171 | ||
2172 | if (rtx_equal_p (x, p->exp)) | |
2173 | q = 0; | |
2174 | else | |
2175 | for (q = p->first_same_value; q; q = q->next_same_value) | |
f8cfc6aa | 2176 | if (REG_P (q->exp)) |
7afe21cc RK |
2177 | break; |
2178 | ||
2179 | if (q) | |
2180 | break; | |
2181 | ||
2182 | p = p->related_value; | |
2183 | ||
2184 | /* We went all the way around, so there is nothing to be found. | |
2185 | Alternatively, perhaps RELT was in the table for some other reason | |
2186 | and it has no related values recorded. */ | |
2187 | if (p == relt || p == 0) | |
2188 | break; | |
2189 | } | |
2190 | ||
2191 | if (q == 0) | |
2192 | return 0; | |
2193 | ||
2194 | offset = (get_integer_term (x) - get_integer_term (p->exp)); | |
2195 | /* Note: OFFSET may be 0 if P->xexp and X are related by commutativity. */ | |
0a81f074 | 2196 | return plus_constant (q->mode, q->exp, offset); |
7afe21cc RK |
2197 | } |
2198 | \f | |
e855c69d | 2199 | |
6462bb43 AO |
2200 | /* Hash a string. Just add its bytes up. */ |
2201 | static inline unsigned | |
0516f6fe | 2202 | hash_rtx_string (const char *ps) |
6462bb43 AO |
2203 | { |
2204 | unsigned hash = 0; | |
68252e27 KH |
2205 | const unsigned char *p = (const unsigned char *) ps; |
2206 | ||
6462bb43 AO |
2207 | if (p) |
2208 | while (*p) | |
2209 | hash += *p++; | |
2210 | ||
2211 | return hash; | |
2212 | } | |
2213 | ||
b8698a0f | 2214 | /* Same as hash_rtx, but call CB on each rtx if it is not NULL. |
e855c69d | 2215 | When the callback returns true, we continue with the new rtx. */ |
7afe21cc | 2216 | |
0516f6fe | 2217 | unsigned |
ef4bddc2 | 2218 | hash_rtx_cb (const_rtx x, machine_mode mode, |
e855c69d AB |
2219 | int *do_not_record_p, int *hash_arg_in_memory_p, |
2220 | bool have_reg_qty, hash_rtx_callback_function cb) | |
7afe21cc | 2221 | { |
b3694847 SS |
2222 | int i, j; |
2223 | unsigned hash = 0; | |
2224 | enum rtx_code code; | |
2225 | const char *fmt; | |
ef4bddc2 | 2226 | machine_mode newmode; |
e855c69d | 2227 | rtx newx; |
7afe21cc | 2228 | |
0516f6fe SB |
2229 | /* Used to turn recursion into iteration. We can't rely on GCC's |
2230 | tail-recursion elimination since we need to keep accumulating values | |
2231 | in HASH. */ | |
7afe21cc RK |
2232 | repeat: |
2233 | if (x == 0) | |
2234 | return hash; | |
2235 | ||
e855c69d | 2236 | /* Invoke the callback first. */ |
b8698a0f | 2237 | if (cb != NULL |
e855c69d AB |
2238 | && ((*cb) (x, mode, &newx, &newmode))) |
2239 | { | |
2240 | hash += hash_rtx_cb (newx, newmode, do_not_record_p, | |
2241 | hash_arg_in_memory_p, have_reg_qty, cb); | |
2242 | return hash; | |
2243 | } | |
2244 | ||
7afe21cc RK |
2245 | code = GET_CODE (x); |
2246 | switch (code) | |
2247 | { | |
2248 | case REG: | |
2249 | { | |
770ae6cc | 2250 | unsigned int regno = REGNO (x); |
7afe21cc | 2251 | |
e855c69d | 2252 | if (do_not_record_p && !reload_completed) |
7afe21cc | 2253 | { |
0516f6fe SB |
2254 | /* On some machines, we can't record any non-fixed hard register, |
2255 | because extending its life will cause reload problems. We | |
2256 | consider ap, fp, sp, gp to be fixed for this purpose. | |
2257 | ||
2258 | We also consider CCmode registers to be fixed for this purpose; | |
2259 | failure to do so leads to failure to simplify 0<100 type of | |
2260 | conditionals. | |
2261 | ||
2262 | On all machines, we can't record any global registers. | |
2263 | Nor should we record any register that is in a small | |
07b8f0a8 | 2264 | class, as defined by TARGET_CLASS_LIKELY_SPILLED_P. */ |
0516f6fe SB |
2265 | bool record; |
2266 | ||
2267 | if (regno >= FIRST_PSEUDO_REGISTER) | |
2268 | record = true; | |
2269 | else if (x == frame_pointer_rtx | |
2270 | || x == hard_frame_pointer_rtx | |
2271 | || x == arg_pointer_rtx | |
2272 | || x == stack_pointer_rtx | |
2273 | || x == pic_offset_table_rtx) | |
2274 | record = true; | |
2275 | else if (global_regs[regno]) | |
2276 | record = false; | |
2277 | else if (fixed_regs[regno]) | |
2278 | record = true; | |
2279 | else if (GET_MODE_CLASS (GET_MODE (x)) == MODE_CC) | |
2280 | record = true; | |
42db504c | 2281 | else if (targetm.small_register_classes_for_mode_p (GET_MODE (x))) |
0516f6fe | 2282 | record = false; |
07b8f0a8 | 2283 | else if (targetm.class_likely_spilled_p (REGNO_REG_CLASS (regno))) |
0516f6fe SB |
2284 | record = false; |
2285 | else | |
2286 | record = true; | |
2287 | ||
2288 | if (!record) | |
2289 | { | |
2290 | *do_not_record_p = 1; | |
2291 | return 0; | |
2292 | } | |
7afe21cc | 2293 | } |
770ae6cc | 2294 | |
0516f6fe SB |
2295 | hash += ((unsigned int) REG << 7); |
2296 | hash += (have_reg_qty ? (unsigned) REG_QTY (regno) : regno); | |
2197a88a | 2297 | return hash; |
7afe21cc RK |
2298 | } |
2299 | ||
34c73909 R |
2300 | /* We handle SUBREG of a REG specially because the underlying |
2301 | reg changes its hash value with every value change; we don't | |
2302 | want to have to forget unrelated subregs when one subreg changes. */ | |
2303 | case SUBREG: | |
2304 | { | |
f8cfc6aa | 2305 | if (REG_P (SUBREG_REG (x))) |
34c73909 | 2306 | { |
0516f6fe | 2307 | hash += (((unsigned int) SUBREG << 7) |
ddef6bc7 JJ |
2308 | + REGNO (SUBREG_REG (x)) |
2309 | + (SUBREG_BYTE (x) / UNITS_PER_WORD)); | |
34c73909 R |
2310 | return hash; |
2311 | } | |
2312 | break; | |
2313 | } | |
2314 | ||
7afe21cc | 2315 | case CONST_INT: |
0516f6fe SB |
2316 | hash += (((unsigned int) CONST_INT << 7) + (unsigned int) mode |
2317 | + (unsigned int) INTVAL (x)); | |
2318 | return hash; | |
7afe21cc | 2319 | |
807e902e KZ |
2320 | case CONST_WIDE_INT: |
2321 | for (i = 0; i < CONST_WIDE_INT_NUNITS (x); i++) | |
2322 | hash += CONST_WIDE_INT_ELT (x, i); | |
2323 | return hash; | |
2324 | ||
7afe21cc RK |
2325 | case CONST_DOUBLE: |
2326 | /* This is like the general case, except that it only counts | |
2327 | the integers representing the constant. */ | |
0516f6fe | 2328 | hash += (unsigned int) code + (unsigned int) GET_MODE (x); |
807e902e | 2329 | if (TARGET_SUPPORTS_WIDE_INT == 0 && GET_MODE (x) == VOIDmode) |
0516f6fe SB |
2330 | hash += ((unsigned int) CONST_DOUBLE_LOW (x) |
2331 | + (unsigned int) CONST_DOUBLE_HIGH (x)); | |
807e902e KZ |
2332 | else |
2333 | hash += real_hash (CONST_DOUBLE_REAL_VALUE (x)); | |
7afe21cc RK |
2334 | return hash; |
2335 | ||
091a3ac7 CF |
2336 | case CONST_FIXED: |
2337 | hash += (unsigned int) code + (unsigned int) GET_MODE (x); | |
2338 | hash += fixed_hash (CONST_FIXED_VALUE (x)); | |
2339 | return hash; | |
2340 | ||
69ef87e2 AH |
2341 | case CONST_VECTOR: |
2342 | { | |
2343 | int units; | |
2344 | rtx elt; | |
2345 | ||
2346 | units = CONST_VECTOR_NUNITS (x); | |
2347 | ||
2348 | for (i = 0; i < units; ++i) | |
2349 | { | |
2350 | elt = CONST_VECTOR_ELT (x, i); | |
e855c69d | 2351 | hash += hash_rtx_cb (elt, GET_MODE (elt), |
b8698a0f | 2352 | do_not_record_p, hash_arg_in_memory_p, |
e855c69d | 2353 | have_reg_qty, cb); |
69ef87e2 AH |
2354 | } |
2355 | ||
2356 | return hash; | |
2357 | } | |
2358 | ||
7afe21cc RK |
2359 | /* Assume there is only one rtx object for any given label. */ |
2360 | case LABEL_REF: | |
0516f6fe SB |
2361 | /* We don't hash on the address of the CODE_LABEL to avoid bootstrap |
2362 | differences and differences between each stage's debugging dumps. */ | |
2363 | hash += (((unsigned int) LABEL_REF << 7) | |
04a121a7 | 2364 | + CODE_LABEL_NUMBER (label_ref_label (x))); |
2197a88a | 2365 | return hash; |
7afe21cc RK |
2366 | |
2367 | case SYMBOL_REF: | |
0516f6fe SB |
2368 | { |
2369 | /* Don't hash on the symbol's address to avoid bootstrap differences. | |
2370 | Different hash values may cause expressions to be recorded in | |
2371 | different orders and thus different registers to be used in the | |
2372 | final assembler. This also avoids differences in the dump files | |
2373 | between various stages. */ | |
2374 | unsigned int h = 0; | |
2375 | const unsigned char *p = (const unsigned char *) XSTR (x, 0); | |
2376 | ||
2377 | while (*p) | |
2378 | h += (h << 7) + *p++; /* ??? revisit */ | |
2379 | ||
2380 | hash += ((unsigned int) SYMBOL_REF << 7) + h; | |
2381 | return hash; | |
2382 | } | |
7afe21cc RK |
2383 | |
2384 | case MEM: | |
14a774a9 RK |
2385 | /* We don't record if marked volatile or if BLKmode since we don't |
2386 | know the size of the move. */ | |
e855c69d | 2387 | if (do_not_record_p && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode)) |
7afe21cc | 2388 | { |
0516f6fe | 2389 | *do_not_record_p = 1; |
7afe21cc RK |
2390 | return 0; |
2391 | } | |
0516f6fe SB |
2392 | if (hash_arg_in_memory_p && !MEM_READONLY_P (x)) |
2393 | *hash_arg_in_memory_p = 1; | |
4977bab6 | 2394 | |
7afe21cc RK |
2395 | /* Now that we have already found this special case, |
2396 | might as well speed it up as much as possible. */ | |
2197a88a | 2397 | hash += (unsigned) MEM; |
7afe21cc RK |
2398 | x = XEXP (x, 0); |
2399 | goto repeat; | |
2400 | ||
bb07060a JW |
2401 | case USE: |
2402 | /* A USE that mentions non-volatile memory needs special | |
2403 | handling since the MEM may be BLKmode which normally | |
2404 | prevents an entry from being made. Pure calls are | |
0516f6fe SB |
2405 | marked by a USE which mentions BLKmode memory. |
2406 | See calls.c:emit_call_1. */ | |
3c0cb5de | 2407 | if (MEM_P (XEXP (x, 0)) |
bb07060a JW |
2408 | && ! MEM_VOLATILE_P (XEXP (x, 0))) |
2409 | { | |
68252e27 | 2410 | hash += (unsigned) USE; |
bb07060a JW |
2411 | x = XEXP (x, 0); |
2412 | ||
0516f6fe SB |
2413 | if (hash_arg_in_memory_p && !MEM_READONLY_P (x)) |
2414 | *hash_arg_in_memory_p = 1; | |
bb07060a JW |
2415 | |
2416 | /* Now that we have already found this special case, | |
2417 | might as well speed it up as much as possible. */ | |
2418 | hash += (unsigned) MEM; | |
2419 | x = XEXP (x, 0); | |
2420 | goto repeat; | |
2421 | } | |
2422 | break; | |
2423 | ||
7afe21cc RK |
2424 | case PRE_DEC: |
2425 | case PRE_INC: | |
2426 | case POST_DEC: | |
2427 | case POST_INC: | |
4b983fdc RH |
2428 | case PRE_MODIFY: |
2429 | case POST_MODIFY: | |
7afe21cc RK |
2430 | case PC: |
2431 | case CC0: | |
2432 | case CALL: | |
2433 | case UNSPEC_VOLATILE: | |
e855c69d AB |
2434 | if (do_not_record_p) { |
2435 | *do_not_record_p = 1; | |
2436 | return 0; | |
2437 | } | |
2438 | else | |
2439 | return hash; | |
2440 | break; | |
7afe21cc RK |
2441 | |
2442 | case ASM_OPERANDS: | |
e855c69d | 2443 | if (do_not_record_p && MEM_VOLATILE_P (x)) |
7afe21cc | 2444 | { |
0516f6fe | 2445 | *do_not_record_p = 1; |
7afe21cc RK |
2446 | return 0; |
2447 | } | |
6462bb43 AO |
2448 | else |
2449 | { | |
2450 | /* We don't want to take the filename and line into account. */ | |
2451 | hash += (unsigned) code + (unsigned) GET_MODE (x) | |
0516f6fe SB |
2452 | + hash_rtx_string (ASM_OPERANDS_TEMPLATE (x)) |
2453 | + hash_rtx_string (ASM_OPERANDS_OUTPUT_CONSTRAINT (x)) | |
6462bb43 AO |
2454 | + (unsigned) ASM_OPERANDS_OUTPUT_IDX (x); |
2455 | ||
2456 | if (ASM_OPERANDS_INPUT_LENGTH (x)) | |
2457 | { | |
2458 | for (i = 1; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) | |
2459 | { | |
e855c69d AB |
2460 | hash += (hash_rtx_cb (ASM_OPERANDS_INPUT (x, i), |
2461 | GET_MODE (ASM_OPERANDS_INPUT (x, i)), | |
2462 | do_not_record_p, hash_arg_in_memory_p, | |
2463 | have_reg_qty, cb) | |
0516f6fe | 2464 | + hash_rtx_string |
e855c69d | 2465 | (ASM_OPERANDS_INPUT_CONSTRAINT (x, i))); |
6462bb43 AO |
2466 | } |
2467 | ||
0516f6fe | 2468 | hash += hash_rtx_string (ASM_OPERANDS_INPUT_CONSTRAINT (x, 0)); |
6462bb43 AO |
2469 | x = ASM_OPERANDS_INPUT (x, 0); |
2470 | mode = GET_MODE (x); | |
2471 | goto repeat; | |
2472 | } | |
2473 | ||
2474 | return hash; | |
2475 | } | |
e9a25f70 | 2476 | break; |
278a83b2 | 2477 | |
e9a25f70 JL |
2478 | default: |
2479 | break; | |
7afe21cc RK |
2480 | } |
2481 | ||
2482 | i = GET_RTX_LENGTH (code) - 1; | |
2197a88a | 2483 | hash += (unsigned) code + (unsigned) GET_MODE (x); |
7afe21cc RK |
2484 | fmt = GET_RTX_FORMAT (code); |
2485 | for (; i >= 0; i--) | |
2486 | { | |
341c100f | 2487 | switch (fmt[i]) |
7afe21cc | 2488 | { |
341c100f | 2489 | case 'e': |
7afe21cc RK |
2490 | /* If we are about to do the last recursive call |
2491 | needed at this level, change it into iteration. | |
2492 | This function is called enough to be worth it. */ | |
2493 | if (i == 0) | |
2494 | { | |
0516f6fe | 2495 | x = XEXP (x, i); |
7afe21cc RK |
2496 | goto repeat; |
2497 | } | |
b8698a0f | 2498 | |
bbbbb16a | 2499 | hash += hash_rtx_cb (XEXP (x, i), VOIDmode, do_not_record_p, |
e855c69d AB |
2500 | hash_arg_in_memory_p, |
2501 | have_reg_qty, cb); | |
341c100f | 2502 | break; |
0516f6fe | 2503 | |
341c100f NS |
2504 | case 'E': |
2505 | for (j = 0; j < XVECLEN (x, i); j++) | |
bbbbb16a | 2506 | hash += hash_rtx_cb (XVECEXP (x, i, j), VOIDmode, do_not_record_p, |
e855c69d AB |
2507 | hash_arg_in_memory_p, |
2508 | have_reg_qty, cb); | |
341c100f | 2509 | break; |
0516f6fe | 2510 | |
341c100f NS |
2511 | case 's': |
2512 | hash += hash_rtx_string (XSTR (x, i)); | |
2513 | break; | |
2514 | ||
2515 | case 'i': | |
2516 | hash += (unsigned int) XINT (x, i); | |
2517 | break; | |
2518 | ||
2519 | case '0': case 't': | |
2520 | /* Unused. */ | |
2521 | break; | |
2522 | ||
2523 | default: | |
2524 | gcc_unreachable (); | |
2525 | } | |
7afe21cc | 2526 | } |
0516f6fe | 2527 | |
7afe21cc RK |
2528 | return hash; |
2529 | } | |
2530 | ||
e855c69d AB |
2531 | /* Hash an rtx. We are careful to make sure the value is never negative. |
2532 | Equivalent registers hash identically. | |
2533 | MODE is used in hashing for CONST_INTs only; | |
2534 | otherwise the mode of X is used. | |
2535 | ||
2536 | Store 1 in DO_NOT_RECORD_P if any subexpression is volatile. | |
2537 | ||
2538 | If HASH_ARG_IN_MEMORY_P is not NULL, store 1 in it if X contains | |
3e55d79b | 2539 | a MEM rtx which does not have the MEM_READONLY_P flag set. |
e855c69d AB |
2540 | |
2541 | Note that cse_insn knows that the hash code of a MEM expression | |
2542 | is just (int) MEM plus the hash code of the address. */ | |
2543 | ||
2544 | unsigned | |
ef4bddc2 | 2545 | hash_rtx (const_rtx x, machine_mode mode, int *do_not_record_p, |
e855c69d AB |
2546 | int *hash_arg_in_memory_p, bool have_reg_qty) |
2547 | { | |
2548 | return hash_rtx_cb (x, mode, do_not_record_p, | |
2549 | hash_arg_in_memory_p, have_reg_qty, NULL); | |
2550 | } | |
2551 | ||
0516f6fe SB |
2552 | /* Hash an rtx X for cse via hash_rtx. |
2553 | Stores 1 in do_not_record if any subexpression is volatile. | |
2554 | Stores 1 in hash_arg_in_memory if X contains a mem rtx which | |
3e55d79b | 2555 | does not have the MEM_READONLY_P flag set. */ |
0516f6fe SB |
2556 | |
2557 | static inline unsigned | |
ef4bddc2 | 2558 | canon_hash (rtx x, machine_mode mode) |
0516f6fe SB |
2559 | { |
2560 | return hash_rtx (x, mode, &do_not_record, &hash_arg_in_memory, true); | |
2561 | } | |
2562 | ||
2563 | /* Like canon_hash but with no side effects, i.e. do_not_record | |
2564 | and hash_arg_in_memory are not changed. */ | |
7afe21cc | 2565 | |
0516f6fe | 2566 | static inline unsigned |
ef4bddc2 | 2567 | safe_hash (rtx x, machine_mode mode) |
7afe21cc | 2568 | { |
0516f6fe SB |
2569 | int dummy_do_not_record; |
2570 | return hash_rtx (x, mode, &dummy_do_not_record, NULL, true); | |
7afe21cc RK |
2571 | } |
2572 | \f | |
2573 | /* Return 1 iff X and Y would canonicalize into the same thing, | |
2574 | without actually constructing the canonicalization of either one. | |
2575 | If VALIDATE is nonzero, | |
2576 | we assume X is an expression being processed from the rtl | |
2577 | and Y was found in the hash table. We check register refs | |
2578 | in Y for being marked as valid. | |
2579 | ||
0516f6fe | 2580 | If FOR_GCSE is true, we compare X and Y for equivalence for GCSE. */ |
7afe21cc | 2581 | |
0516f6fe | 2582 | int |
4f588890 | 2583 | exp_equiv_p (const_rtx x, const_rtx y, int validate, bool for_gcse) |
7afe21cc | 2584 | { |
b3694847 SS |
2585 | int i, j; |
2586 | enum rtx_code code; | |
2587 | const char *fmt; | |
7afe21cc RK |
2588 | |
2589 | /* Note: it is incorrect to assume an expression is equivalent to itself | |
2590 | if VALIDATE is nonzero. */ | |
2591 | if (x == y && !validate) | |
2592 | return 1; | |
0516f6fe | 2593 | |
7afe21cc RK |
2594 | if (x == 0 || y == 0) |
2595 | return x == y; | |
2596 | ||
2597 | code = GET_CODE (x); | |
2598 | if (code != GET_CODE (y)) | |
0516f6fe | 2599 | return 0; |
7afe21cc RK |
2600 | |
2601 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
2602 | if (GET_MODE (x) != GET_MODE (y)) | |
2603 | return 0; | |
2604 | ||
5932a4d4 | 2605 | /* MEMs referring to different address space are not equivalent. */ |
09e881c9 BE |
2606 | if (code == MEM && MEM_ADDR_SPACE (x) != MEM_ADDR_SPACE (y)) |
2607 | return 0; | |
2608 | ||
7afe21cc RK |
2609 | switch (code) |
2610 | { | |
2611 | case PC: | |
2612 | case CC0: | |
d8116890 | 2613 | CASE_CONST_UNIQUE: |
c13e8210 | 2614 | return x == y; |
7afe21cc RK |
2615 | |
2616 | case LABEL_REF: | |
04a121a7 | 2617 | return label_ref_label (x) == label_ref_label (y); |
7afe21cc | 2618 | |
f54d4924 RK |
2619 | case SYMBOL_REF: |
2620 | return XSTR (x, 0) == XSTR (y, 0); | |
2621 | ||
7afe21cc | 2622 | case REG: |
0516f6fe SB |
2623 | if (for_gcse) |
2624 | return REGNO (x) == REGNO (y); | |
2625 | else | |
2626 | { | |
2627 | unsigned int regno = REGNO (y); | |
2628 | unsigned int i; | |
09e18274 | 2629 | unsigned int endregno = END_REGNO (y); |
7afe21cc | 2630 | |
0516f6fe SB |
2631 | /* If the quantities are not the same, the expressions are not |
2632 | equivalent. If there are and we are not to validate, they | |
2633 | are equivalent. Otherwise, ensure all regs are up-to-date. */ | |
7afe21cc | 2634 | |
0516f6fe SB |
2635 | if (REG_QTY (REGNO (x)) != REG_QTY (regno)) |
2636 | return 0; | |
2637 | ||
2638 | if (! validate) | |
2639 | return 1; | |
2640 | ||
2641 | for (i = regno; i < endregno; i++) | |
2642 | if (REG_IN_TABLE (i) != REG_TICK (i)) | |
2643 | return 0; | |
7afe21cc | 2644 | |
7afe21cc | 2645 | return 1; |
0516f6fe | 2646 | } |
7afe21cc | 2647 | |
0516f6fe SB |
2648 | case MEM: |
2649 | if (for_gcse) | |
2650 | { | |
0516f6fe SB |
2651 | /* A volatile mem should not be considered equivalent to any |
2652 | other. */ | |
2653 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
2654 | return 0; | |
8a76c4a0 JJ |
2655 | |
2656 | /* Can't merge two expressions in different alias sets, since we | |
2657 | can decide that the expression is transparent in a block when | |
2658 | it isn't, due to it being set with the different alias set. | |
2659 | ||
2660 | Also, can't merge two expressions with different MEM_ATTRS. | |
2661 | They could e.g. be two different entities allocated into the | |
2662 | same space on the stack (see e.g. PR25130). In that case, the | |
2663 | MEM addresses can be the same, even though the two MEMs are | |
2664 | absolutely not equivalent. | |
2665 | ||
2666 | But because really all MEM attributes should be the same for | |
2667 | equivalent MEMs, we just use the invariant that MEMs that have | |
2668 | the same attributes share the same mem_attrs data structure. */ | |
96b3c03f | 2669 | if (!mem_attrs_eq_p (MEM_ATTRS (x), MEM_ATTRS (y))) |
8a76c4a0 | 2670 | return 0; |
e304caa4 EB |
2671 | |
2672 | /* If we are handling exceptions, we cannot consider two expressions | |
2673 | with different trapping status as equivalent, because simple_mem | |
2674 | might accept one and reject the other. */ | |
2675 | if (cfun->can_throw_non_call_exceptions | |
2676 | && (MEM_NOTRAP_P (x) != MEM_NOTRAP_P (y))) | |
2677 | return 0; | |
0516f6fe SB |
2678 | } |
2679 | break; | |
7afe21cc RK |
2680 | |
2681 | /* For commutative operations, check both orders. */ | |
2682 | case PLUS: | |
2683 | case MULT: | |
2684 | case AND: | |
2685 | case IOR: | |
2686 | case XOR: | |
2687 | case NE: | |
2688 | case EQ: | |
0516f6fe SB |
2689 | return ((exp_equiv_p (XEXP (x, 0), XEXP (y, 0), |
2690 | validate, for_gcse) | |
7afe21cc | 2691 | && exp_equiv_p (XEXP (x, 1), XEXP (y, 1), |
0516f6fe | 2692 | validate, for_gcse)) |
7afe21cc | 2693 | || (exp_equiv_p (XEXP (x, 0), XEXP (y, 1), |
0516f6fe | 2694 | validate, for_gcse) |
7afe21cc | 2695 | && exp_equiv_p (XEXP (x, 1), XEXP (y, 0), |
0516f6fe | 2696 | validate, for_gcse))); |
278a83b2 | 2697 | |
6462bb43 AO |
2698 | case ASM_OPERANDS: |
2699 | /* We don't use the generic code below because we want to | |
2700 | disregard filename and line numbers. */ | |
2701 | ||
2702 | /* A volatile asm isn't equivalent to any other. */ | |
2703 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
2704 | return 0; | |
2705 | ||
2706 | if (GET_MODE (x) != GET_MODE (y) | |
2707 | || strcmp (ASM_OPERANDS_TEMPLATE (x), ASM_OPERANDS_TEMPLATE (y)) | |
2708 | || strcmp (ASM_OPERANDS_OUTPUT_CONSTRAINT (x), | |
2709 | ASM_OPERANDS_OUTPUT_CONSTRAINT (y)) | |
2710 | || ASM_OPERANDS_OUTPUT_IDX (x) != ASM_OPERANDS_OUTPUT_IDX (y) | |
2711 | || ASM_OPERANDS_INPUT_LENGTH (x) != ASM_OPERANDS_INPUT_LENGTH (y)) | |
2712 | return 0; | |
2713 | ||
2714 | if (ASM_OPERANDS_INPUT_LENGTH (x)) | |
2715 | { | |
2716 | for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
2717 | if (! exp_equiv_p (ASM_OPERANDS_INPUT (x, i), | |
2718 | ASM_OPERANDS_INPUT (y, i), | |
0516f6fe | 2719 | validate, for_gcse) |
6462bb43 AO |
2720 | || strcmp (ASM_OPERANDS_INPUT_CONSTRAINT (x, i), |
2721 | ASM_OPERANDS_INPUT_CONSTRAINT (y, i))) | |
2722 | return 0; | |
2723 | } | |
2724 | ||
2725 | return 1; | |
2726 | ||
e9a25f70 JL |
2727 | default: |
2728 | break; | |
7afe21cc RK |
2729 | } |
2730 | ||
2731 | /* Compare the elements. If any pair of corresponding elements | |
0516f6fe | 2732 | fail to match, return 0 for the whole thing. */ |
7afe21cc RK |
2733 | |
2734 | fmt = GET_RTX_FORMAT (code); | |
2735 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2736 | { | |
906c4e36 | 2737 | switch (fmt[i]) |
7afe21cc | 2738 | { |
906c4e36 | 2739 | case 'e': |
0516f6fe SB |
2740 | if (! exp_equiv_p (XEXP (x, i), XEXP (y, i), |
2741 | validate, for_gcse)) | |
7afe21cc | 2742 | return 0; |
906c4e36 RK |
2743 | break; |
2744 | ||
2745 | case 'E': | |
7afe21cc RK |
2746 | if (XVECLEN (x, i) != XVECLEN (y, i)) |
2747 | return 0; | |
2748 | for (j = 0; j < XVECLEN (x, i); j++) | |
2749 | if (! exp_equiv_p (XVECEXP (x, i, j), XVECEXP (y, i, j), | |
0516f6fe | 2750 | validate, for_gcse)) |
7afe21cc | 2751 | return 0; |
906c4e36 RK |
2752 | break; |
2753 | ||
2754 | case 's': | |
7afe21cc RK |
2755 | if (strcmp (XSTR (x, i), XSTR (y, i))) |
2756 | return 0; | |
906c4e36 RK |
2757 | break; |
2758 | ||
2759 | case 'i': | |
7afe21cc RK |
2760 | if (XINT (x, i) != XINT (y, i)) |
2761 | return 0; | |
906c4e36 RK |
2762 | break; |
2763 | ||
2764 | case 'w': | |
2765 | if (XWINT (x, i) != XWINT (y, i)) | |
2766 | return 0; | |
278a83b2 | 2767 | break; |
906c4e36 RK |
2768 | |
2769 | case '0': | |
8f985ec4 | 2770 | case 't': |
906c4e36 RK |
2771 | break; |
2772 | ||
2773 | default: | |
341c100f | 2774 | gcc_unreachable (); |
7afe21cc | 2775 | } |
278a83b2 | 2776 | } |
906c4e36 | 2777 | |
7afe21cc RK |
2778 | return 1; |
2779 | } | |
2780 | \f | |
eef3c949 RS |
2781 | /* Subroutine of canon_reg. Pass *XLOC through canon_reg, and validate |
2782 | the result if necessary. INSN is as for canon_reg. */ | |
2783 | ||
2784 | static void | |
20468884 | 2785 | validate_canon_reg (rtx *xloc, rtx_insn *insn) |
eef3c949 | 2786 | { |
6fb5fa3c DB |
2787 | if (*xloc) |
2788 | { | |
32e9fa48 | 2789 | rtx new_rtx = canon_reg (*xloc, insn); |
eef3c949 | 2790 | |
6fb5fa3c DB |
2791 | /* If replacing pseudo with hard reg or vice versa, ensure the |
2792 | insn remains valid. Likewise if the insn has MATCH_DUPs. */ | |
32e9fa48 KG |
2793 | gcc_assert (insn && new_rtx); |
2794 | validate_change (insn, xloc, new_rtx, 1); | |
6fb5fa3c | 2795 | } |
eef3c949 RS |
2796 | } |
2797 | ||
7afe21cc RK |
2798 | /* Canonicalize an expression: |
2799 | replace each register reference inside it | |
2800 | with the "oldest" equivalent register. | |
2801 | ||
67e0a632 | 2802 | If INSN is nonzero validate_change is used to ensure that INSN remains valid |
da7d8304 | 2803 | after we make our substitution. The calls are made with IN_GROUP nonzero |
7722328e RK |
2804 | so apply_change_group must be called upon the outermost return from this |
2805 | function (unless INSN is zero). The result of apply_change_group can | |
2806 | generally be discarded since the changes we are making are optional. */ | |
7afe21cc RK |
2807 | |
2808 | static rtx | |
20468884 | 2809 | canon_reg (rtx x, rtx_insn *insn) |
7afe21cc | 2810 | { |
b3694847 SS |
2811 | int i; |
2812 | enum rtx_code code; | |
2813 | const char *fmt; | |
7afe21cc RK |
2814 | |
2815 | if (x == 0) | |
2816 | return x; | |
2817 | ||
2818 | code = GET_CODE (x); | |
2819 | switch (code) | |
2820 | { | |
2821 | case PC: | |
2822 | case CC0: | |
2823 | case CONST: | |
d8116890 | 2824 | CASE_CONST_ANY: |
7afe21cc RK |
2825 | case SYMBOL_REF: |
2826 | case LABEL_REF: | |
2827 | case ADDR_VEC: | |
2828 | case ADDR_DIFF_VEC: | |
2829 | return x; | |
2830 | ||
2831 | case REG: | |
2832 | { | |
b3694847 SS |
2833 | int first; |
2834 | int q; | |
2835 | struct qty_table_elem *ent; | |
7afe21cc RK |
2836 | |
2837 | /* Never replace a hard reg, because hard regs can appear | |
2838 | in more than one machine mode, and we must preserve the mode | |
2839 | of each occurrence. Also, some hard regs appear in | |
2840 | MEMs that are shared and mustn't be altered. Don't try to | |
2841 | replace any reg that maps to a reg of class NO_REGS. */ | |
2842 | if (REGNO (x) < FIRST_PSEUDO_REGISTER | |
2843 | || ! REGNO_QTY_VALID_P (REGNO (x))) | |
2844 | return x; | |
2845 | ||
278a83b2 | 2846 | q = REG_QTY (REGNO (x)); |
1bb98cec DM |
2847 | ent = &qty_table[q]; |
2848 | first = ent->first_reg; | |
7afe21cc RK |
2849 | return (first >= FIRST_PSEUDO_REGISTER ? regno_reg_rtx[first] |
2850 | : REGNO_REG_CLASS (first) == NO_REGS ? x | |
1bb98cec | 2851 | : gen_rtx_REG (ent->mode, first)); |
7afe21cc | 2852 | } |
278a83b2 | 2853 | |
e9a25f70 JL |
2854 | default: |
2855 | break; | |
7afe21cc RK |
2856 | } |
2857 | ||
2858 | fmt = GET_RTX_FORMAT (code); | |
2859 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2860 | { | |
b3694847 | 2861 | int j; |
7afe21cc RK |
2862 | |
2863 | if (fmt[i] == 'e') | |
eef3c949 | 2864 | validate_canon_reg (&XEXP (x, i), insn); |
7afe21cc RK |
2865 | else if (fmt[i] == 'E') |
2866 | for (j = 0; j < XVECLEN (x, i); j++) | |
eef3c949 | 2867 | validate_canon_reg (&XVECEXP (x, i, j), insn); |
7afe21cc RK |
2868 | } |
2869 | ||
2870 | return x; | |
2871 | } | |
2872 | \f | |
bca05d20 RK |
2873 | /* Given an operation (CODE, *PARG1, *PARG2), where code is a comparison |
2874 | operation (EQ, NE, GT, etc.), follow it back through the hash table and | |
2875 | what values are being compared. | |
1a87eea2 | 2876 | |
bca05d20 RK |
2877 | *PARG1 and *PARG2 are updated to contain the rtx representing the values |
2878 | actually being compared. For example, if *PARG1 was (cc0) and *PARG2 | |
2879 | was (const_int 0), *PARG1 and *PARG2 will be set to the objects that were | |
2880 | compared to produce cc0. | |
a432f20d | 2881 | |
bca05d20 RK |
2882 | The return value is the comparison operator and is either the code of |
2883 | A or the code corresponding to the inverse of the comparison. */ | |
7afe21cc | 2884 | |
0cedb36c | 2885 | static enum rtx_code |
7080f735 | 2886 | find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2, |
ef4bddc2 | 2887 | machine_mode *pmode1, machine_mode *pmode2) |
7afe21cc | 2888 | { |
0cedb36c | 2889 | rtx arg1, arg2; |
6e2830c3 | 2890 | hash_set<rtx> *visited = NULL; |
27ec0502 AJ |
2891 | /* Set nonzero when we find something of interest. */ |
2892 | rtx x = NULL; | |
1a87eea2 | 2893 | |
0cedb36c | 2894 | arg1 = *parg1, arg2 = *parg2; |
7afe21cc | 2895 | |
0cedb36c | 2896 | /* If ARG2 is const0_rtx, see what ARG1 is equivalent to. */ |
7afe21cc | 2897 | |
0cedb36c | 2898 | while (arg2 == CONST0_RTX (GET_MODE (arg1))) |
a432f20d | 2899 | { |
0cedb36c JL |
2900 | int reverse_code = 0; |
2901 | struct table_elt *p = 0; | |
6076248a | 2902 | |
27ec0502 AJ |
2903 | /* Remember state from previous iteration. */ |
2904 | if (x) | |
2905 | { | |
2906 | if (!visited) | |
6e2830c3 TS |
2907 | visited = new hash_set<rtx>; |
2908 | visited->add (x); | |
27ec0502 AJ |
2909 | x = 0; |
2910 | } | |
2911 | ||
0cedb36c JL |
2912 | /* If arg1 is a COMPARE, extract the comparison arguments from it. |
2913 | On machines with CC0, this is the only case that can occur, since | |
2914 | fold_rtx will return the COMPARE or item being compared with zero | |
2915 | when given CC0. */ | |
6076248a | 2916 | |
0cedb36c JL |
2917 | if (GET_CODE (arg1) == COMPARE && arg2 == const0_rtx) |
2918 | x = arg1; | |
6076248a | 2919 | |
0cedb36c JL |
2920 | /* If ARG1 is a comparison operator and CODE is testing for |
2921 | STORE_FLAG_VALUE, get the inner arguments. */ | |
a432f20d | 2922 | |
ec8e098d | 2923 | else if (COMPARISON_P (arg1)) |
7afe21cc | 2924 | { |
efdc7e19 RH |
2925 | #ifdef FLOAT_STORE_FLAG_VALUE |
2926 | REAL_VALUE_TYPE fsfv; | |
2927 | #endif | |
2928 | ||
0cedb36c JL |
2929 | if (code == NE |
2930 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT | |
2931 | && code == LT && STORE_FLAG_VALUE == -1) | |
2932 | #ifdef FLOAT_STORE_FLAG_VALUE | |
9b92bf04 | 2933 | || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1)) |
efdc7e19 RH |
2934 | && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)), |
2935 | REAL_VALUE_NEGATIVE (fsfv))) | |
7afe21cc | 2936 | #endif |
a432f20d | 2937 | ) |
0cedb36c JL |
2938 | x = arg1; |
2939 | else if (code == EQ | |
2940 | || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT | |
2941 | && code == GE && STORE_FLAG_VALUE == -1) | |
2942 | #ifdef FLOAT_STORE_FLAG_VALUE | |
9b92bf04 | 2943 | || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1)) |
efdc7e19 RH |
2944 | && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)), |
2945 | REAL_VALUE_NEGATIVE (fsfv))) | |
0cedb36c JL |
2946 | #endif |
2947 | ) | |
2948 | x = arg1, reverse_code = 1; | |
7afe21cc RK |
2949 | } |
2950 | ||
0cedb36c | 2951 | /* ??? We could also check for |
7afe21cc | 2952 | |
0cedb36c | 2953 | (ne (and (eq (...) (const_int 1))) (const_int 0)) |
7afe21cc | 2954 | |
0cedb36c | 2955 | and related forms, but let's wait until we see them occurring. */ |
7afe21cc | 2956 | |
0cedb36c JL |
2957 | if (x == 0) |
2958 | /* Look up ARG1 in the hash table and see if it has an equivalence | |
2959 | that lets us see what is being compared. */ | |
0516f6fe | 2960 | p = lookup (arg1, SAFE_HASH (arg1, GET_MODE (arg1)), GET_MODE (arg1)); |
278a83b2 | 2961 | if (p) |
8b03b984 R |
2962 | { |
2963 | p = p->first_same_value; | |
2964 | ||
2965 | /* If what we compare is already known to be constant, that is as | |
2966 | good as it gets. | |
2967 | We need to break the loop in this case, because otherwise we | |
2968 | can have an infinite loop when looking at a reg that is known | |
2969 | to be a constant which is the same as a comparison of a reg | |
2970 | against zero which appears later in the insn stream, which in | |
2971 | turn is constant and the same as the comparison of the first reg | |
2972 | against zero... */ | |
2973 | if (p->is_const) | |
2974 | break; | |
2975 | } | |
7afe21cc | 2976 | |
0cedb36c | 2977 | for (; p; p = p->next_same_value) |
7afe21cc | 2978 | { |
ef4bddc2 | 2979 | machine_mode inner_mode = GET_MODE (p->exp); |
efdc7e19 RH |
2980 | #ifdef FLOAT_STORE_FLAG_VALUE |
2981 | REAL_VALUE_TYPE fsfv; | |
2982 | #endif | |
7afe21cc | 2983 | |
0cedb36c | 2984 | /* If the entry isn't valid, skip it. */ |
0516f6fe | 2985 | if (! exp_equiv_p (p->exp, p->exp, 1, false)) |
0cedb36c | 2986 | continue; |
f76b9db2 | 2987 | |
27ec0502 | 2988 | /* If it's a comparison we've used before, skip it. */ |
6e2830c3 | 2989 | if (visited && visited->contains (p->exp)) |
8f1ad6b6 SL |
2990 | continue; |
2991 | ||
bca05d20 RK |
2992 | if (GET_CODE (p->exp) == COMPARE |
2993 | /* Another possibility is that this machine has a compare insn | |
2994 | that includes the comparison code. In that case, ARG1 would | |
2995 | be equivalent to a comparison operation that would set ARG1 to | |
2996 | either STORE_FLAG_VALUE or zero. If this is an NE operation, | |
2997 | ORIG_CODE is the actual comparison being done; if it is an EQ, | |
2998 | we must reverse ORIG_CODE. On machine with a negative value | |
2999 | for STORE_FLAG_VALUE, also look at LT and GE operations. */ | |
3000 | || ((code == NE | |
3001 | || (code == LT | |
2d0c270f BS |
3002 | && val_signbit_known_set_p (inner_mode, |
3003 | STORE_FLAG_VALUE)) | |
0cedb36c | 3004 | #ifdef FLOAT_STORE_FLAG_VALUE |
bca05d20 | 3005 | || (code == LT |
3d8bf70f | 3006 | && SCALAR_FLOAT_MODE_P (inner_mode) |
efdc7e19 RH |
3007 | && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)), |
3008 | REAL_VALUE_NEGATIVE (fsfv))) | |
0cedb36c | 3009 | #endif |
bca05d20 | 3010 | ) |
ec8e098d | 3011 | && COMPARISON_P (p->exp))) |
7afe21cc | 3012 | { |
0cedb36c JL |
3013 | x = p->exp; |
3014 | break; | |
3015 | } | |
3016 | else if ((code == EQ | |
3017 | || (code == GE | |
2d0c270f BS |
3018 | && val_signbit_known_set_p (inner_mode, |
3019 | STORE_FLAG_VALUE)) | |
0cedb36c JL |
3020 | #ifdef FLOAT_STORE_FLAG_VALUE |
3021 | || (code == GE | |
3d8bf70f | 3022 | && SCALAR_FLOAT_MODE_P (inner_mode) |
efdc7e19 RH |
3023 | && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)), |
3024 | REAL_VALUE_NEGATIVE (fsfv))) | |
0cedb36c JL |
3025 | #endif |
3026 | ) | |
ec8e098d | 3027 | && COMPARISON_P (p->exp)) |
0cedb36c JL |
3028 | { |
3029 | reverse_code = 1; | |
3030 | x = p->exp; | |
3031 | break; | |
7afe21cc RK |
3032 | } |
3033 | ||
4977bab6 ZW |
3034 | /* If this non-trapping address, e.g. fp + constant, the |
3035 | equivalent is a better operand since it may let us predict | |
3036 | the value of the comparison. */ | |
3037 | else if (!rtx_addr_can_trap_p (p->exp)) | |
0cedb36c JL |
3038 | { |
3039 | arg1 = p->exp; | |
3040 | continue; | |
3041 | } | |
7afe21cc | 3042 | } |
7afe21cc | 3043 | |
0cedb36c JL |
3044 | /* If we didn't find a useful equivalence for ARG1, we are done. |
3045 | Otherwise, set up for the next iteration. */ | |
3046 | if (x == 0) | |
3047 | break; | |
7afe21cc | 3048 | |
026c3cfd | 3049 | /* If we need to reverse the comparison, make sure that is |
78192b09 RH |
3050 | possible -- we can't necessarily infer the value of GE from LT |
3051 | with floating-point operands. */ | |
0cedb36c | 3052 | if (reverse_code) |
261efdef | 3053 | { |
c9b0a227 | 3054 | enum rtx_code reversed = reversed_comparison_code (x, NULL); |
261efdef JH |
3055 | if (reversed == UNKNOWN) |
3056 | break; | |
68252e27 KH |
3057 | else |
3058 | code = reversed; | |
261efdef | 3059 | } |
ec8e098d | 3060 | else if (COMPARISON_P (x)) |
261efdef JH |
3061 | code = GET_CODE (x); |
3062 | arg1 = XEXP (x, 0), arg2 = XEXP (x, 1); | |
7afe21cc RK |
3063 | } |
3064 | ||
0cedb36c JL |
3065 | /* Return our results. Return the modes from before fold_rtx |
3066 | because fold_rtx might produce const_int, and then it's too late. */ | |
3067 | *pmode1 = GET_MODE (arg1), *pmode2 = GET_MODE (arg2); | |
3068 | *parg1 = fold_rtx (arg1, 0), *parg2 = fold_rtx (arg2, 0); | |
3069 | ||
27ec0502 | 3070 | if (visited) |
6e2830c3 | 3071 | delete visited; |
0cedb36c | 3072 | return code; |
7afe21cc RK |
3073 | } |
3074 | \f | |
a52b023a PB |
3075 | /* If X is a nontrivial arithmetic operation on an argument for which |
3076 | a constant value can be determined, return the result of operating | |
3077 | on that value, as a constant. Otherwise, return X, possibly with | |
3078 | one or more operands changed to a forward-propagated constant. | |
25910ca4 | 3079 | |
a52b023a PB |
3080 | If X is a register whose contents are known, we do NOT return |
3081 | those contents here; equiv_constant is called to perform that task. | |
3082 | For SUBREGs and MEMs, we do that both here and in equiv_constant. | |
7afe21cc RK |
3083 | |
3084 | INSN is the insn that we may be modifying. If it is 0, make a copy | |
3085 | of X before modifying it. */ | |
3086 | ||
3087 | static rtx | |
20468884 | 3088 | fold_rtx (rtx x, rtx_insn *insn) |
7afe21cc | 3089 | { |
b3694847 | 3090 | enum rtx_code code; |
ef4bddc2 | 3091 | machine_mode mode; |
b3694847 SS |
3092 | const char *fmt; |
3093 | int i; | |
32e9fa48 | 3094 | rtx new_rtx = 0; |
a52b023a | 3095 | int changed = 0; |
7afe21cc | 3096 | |
a52b023a | 3097 | /* Operands of X. */ |
e54bd4ab JJ |
3098 | /* Workaround -Wmaybe-uninitialized false positive during |
3099 | profiledbootstrap by initializing them. */ | |
3100 | rtx folded_arg0 = NULL_RTX; | |
3101 | rtx folded_arg1 = NULL_RTX; | |
7afe21cc RK |
3102 | |
3103 | /* Constant equivalents of first three operands of X; | |
3104 | 0 when no such equivalent is known. */ | |
3105 | rtx const_arg0; | |
3106 | rtx const_arg1; | |
3107 | rtx const_arg2; | |
3108 | ||
3109 | /* The mode of the first operand of X. We need this for sign and zero | |
3110 | extends. */ | |
ef4bddc2 | 3111 | machine_mode mode_arg0; |
7afe21cc RK |
3112 | |
3113 | if (x == 0) | |
3114 | return x; | |
3115 | ||
a52b023a | 3116 | /* Try to perform some initial simplifications on X. */ |
7afe21cc RK |
3117 | code = GET_CODE (x); |
3118 | switch (code) | |
3119 | { | |
a52b023a PB |
3120 | case MEM: |
3121 | case SUBREG: | |
5141ed42 JL |
3122 | /* The first operand of a SIGN/ZERO_EXTRACT has a different meaning |
3123 | than it would in other contexts. Basically its mode does not | |
3124 | signify the size of the object read. That information is carried | |
3125 | by size operand. If we happen to have a MEM of the appropriate | |
3126 | mode in our tables with a constant value we could simplify the | |
3127 | extraction incorrectly if we allowed substitution of that value | |
3128 | for the MEM. */ | |
3129 | case ZERO_EXTRACT: | |
3130 | case SIGN_EXTRACT: | |
32e9fa48 KG |
3131 | if ((new_rtx = equiv_constant (x)) != NULL_RTX) |
3132 | return new_rtx; | |
a52b023a PB |
3133 | return x; |
3134 | ||
7afe21cc | 3135 | case CONST: |
d8116890 | 3136 | CASE_CONST_ANY: |
7afe21cc RK |
3137 | case SYMBOL_REF: |
3138 | case LABEL_REF: | |
3139 | case REG: | |
01aa1d43 | 3140 | case PC: |
7afe21cc RK |
3141 | /* No use simplifying an EXPR_LIST |
3142 | since they are used only for lists of args | |
3143 | in a function call's REG_EQUAL note. */ | |
3144 | case EXPR_LIST: | |
3145 | return x; | |
3146 | ||
7afe21cc RK |
3147 | case CC0: |
3148 | return prev_insn_cc0; | |
7afe21cc | 3149 | |
9255709c | 3150 | case ASM_OPERANDS: |
6c667859 AB |
3151 | if (insn) |
3152 | { | |
3153 | for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
3154 | validate_change (insn, &ASM_OPERANDS_INPUT (x, i), | |
3155 | fold_rtx (ASM_OPERANDS_INPUT (x, i), insn), 0); | |
3156 | } | |
a52b023a PB |
3157 | return x; |
3158 | ||
a52b023a | 3159 | case CALL: |
1e8552c2 | 3160 | if (NO_FUNCTION_CSE && CONSTANT_P (XEXP (XEXP (x, 0), 0))) |
a52b023a | 3161 | return x; |
9255709c | 3162 | break; |
278a83b2 | 3163 | |
a52b023a | 3164 | /* Anything else goes through the loop below. */ |
e9a25f70 JL |
3165 | default: |
3166 | break; | |
7afe21cc RK |
3167 | } |
3168 | ||
a52b023a | 3169 | mode = GET_MODE (x); |
7afe21cc RK |
3170 | const_arg0 = 0; |
3171 | const_arg1 = 0; | |
3172 | const_arg2 = 0; | |
3173 | mode_arg0 = VOIDmode; | |
3174 | ||
3175 | /* Try folding our operands. | |
3176 | Then see which ones have constant values known. */ | |
3177 | ||
3178 | fmt = GET_RTX_FORMAT (code); | |
3179 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
3180 | if (fmt[i] == 'e') | |
3181 | { | |
a52b023a | 3182 | rtx folded_arg = XEXP (x, i), const_arg; |
ef4bddc2 | 3183 | machine_mode mode_arg = GET_MODE (folded_arg); |
7e7e28c7 AO |
3184 | |
3185 | switch (GET_CODE (folded_arg)) | |
3186 | { | |
3187 | case MEM: | |
3188 | case REG: | |
3189 | case SUBREG: | |
3190 | const_arg = equiv_constant (folded_arg); | |
3191 | break; | |
3192 | ||
3193 | case CONST: | |
d8116890 | 3194 | CASE_CONST_ANY: |
7e7e28c7 AO |
3195 | case SYMBOL_REF: |
3196 | case LABEL_REF: | |
7e7e28c7 AO |
3197 | const_arg = folded_arg; |
3198 | break; | |
3199 | ||
7e7e28c7 | 3200 | case CC0: |
728acca0 MP |
3201 | /* The cc0-user and cc0-setter may be in different blocks if |
3202 | the cc0-setter potentially traps. In that case PREV_INSN_CC0 | |
3203 | will have been cleared as we exited the block with the | |
3204 | setter. | |
3205 | ||
3206 | While we could potentially track cc0 in this case, it just | |
3207 | doesn't seem to be worth it given that cc0 targets are not | |
3208 | terribly common or important these days and trapping math | |
3209 | is rarely used. The combination of those two conditions | |
3210 | necessary to trip this situation is exceedingly rare in the | |
3211 | real world. */ | |
3212 | if (!prev_insn_cc0) | |
3213 | { | |
3214 | const_arg = NULL_RTX; | |
3215 | } | |
3216 | else | |
3217 | { | |
3218 | folded_arg = prev_insn_cc0; | |
3219 | mode_arg = prev_insn_cc0_mode; | |
3220 | const_arg = equiv_constant (folded_arg); | |
3221 | } | |
7e7e28c7 | 3222 | break; |
7e7e28c7 AO |
3223 | |
3224 | default: | |
3225 | folded_arg = fold_rtx (folded_arg, insn); | |
3226 | const_arg = equiv_constant (folded_arg); | |
3227 | break; | |
3228 | } | |
7afe21cc RK |
3229 | |
3230 | /* For the first three operands, see if the operand | |
3231 | is constant or equivalent to a constant. */ | |
3232 | switch (i) | |
3233 | { | |
3234 | case 0: | |
3235 | folded_arg0 = folded_arg; | |
3236 | const_arg0 = const_arg; | |
3237 | mode_arg0 = mode_arg; | |
3238 | break; | |
3239 | case 1: | |
3240 | folded_arg1 = folded_arg; | |
3241 | const_arg1 = const_arg; | |
3242 | break; | |
3243 | case 2: | |
3244 | const_arg2 = const_arg; | |
3245 | break; | |
3246 | } | |
3247 | ||
a52b023a PB |
3248 | /* Pick the least expensive of the argument and an equivalent constant |
3249 | argument. */ | |
3250 | if (const_arg != 0 | |
3251 | && const_arg != folded_arg | |
e548c9df AM |
3252 | && (COST_IN (const_arg, mode_arg, code, i) |
3253 | <= COST_IN (folded_arg, mode_arg, code, i)) | |
f2fa288f | 3254 | |
8cce3d04 RS |
3255 | /* It's not safe to substitute the operand of a conversion |
3256 | operator with a constant, as the conversion's identity | |
f652d14b | 3257 | depends upon the mode of its operand. This optimization |
8cce3d04 | 3258 | is handled by the call to simplify_unary_operation. */ |
a52b023a PB |
3259 | && (GET_RTX_CLASS (code) != RTX_UNARY |
3260 | || GET_MODE (const_arg) == mode_arg0 | |
3261 | || (code != ZERO_EXTEND | |
3262 | && code != SIGN_EXTEND | |
3263 | && code != TRUNCATE | |
3264 | && code != FLOAT_TRUNCATE | |
3265 | && code != FLOAT_EXTEND | |
3266 | && code != FLOAT | |
3267 | && code != FIX | |
3268 | && code != UNSIGNED_FLOAT | |
3269 | && code != UNSIGNED_FIX))) | |
3270 | folded_arg = const_arg; | |
3271 | ||
3272 | if (folded_arg == XEXP (x, i)) | |
3273 | continue; | |
7afe21cc | 3274 | |
a52b023a PB |
3275 | if (insn == NULL_RTX && !changed) |
3276 | x = copy_rtx (x); | |
3277 | changed = 1; | |
b8b89e7c | 3278 | validate_unshare_change (insn, &XEXP (x, i), folded_arg, 1); |
2d8b0f3a | 3279 | } |
7afe21cc | 3280 | |
a52b023a | 3281 | if (changed) |
7afe21cc | 3282 | { |
a52b023a PB |
3283 | /* Canonicalize X if necessary, and keep const_argN and folded_argN |
3284 | consistent with the order in X. */ | |
3285 | if (canonicalize_change_group (insn, x)) | |
7afe21cc | 3286 | { |
4e1952ab KT |
3287 | std::swap (const_arg0, const_arg1); |
3288 | std::swap (folded_arg0, folded_arg1); | |
7afe21cc | 3289 | } |
a52b023a PB |
3290 | |
3291 | apply_change_group (); | |
7afe21cc RK |
3292 | } |
3293 | ||
3294 | /* If X is an arithmetic operation, see if we can simplify it. */ | |
3295 | ||
3296 | switch (GET_RTX_CLASS (code)) | |
3297 | { | |
ec8e098d | 3298 | case RTX_UNARY: |
67a37737 | 3299 | { |
67a37737 RK |
3300 | /* We can't simplify extension ops unless we know the |
3301 | original mode. */ | |
3302 | if ((code == ZERO_EXTEND || code == SIGN_EXTEND) | |
3303 | && mode_arg0 == VOIDmode) | |
3304 | break; | |
3305 | ||
32e9fa48 | 3306 | new_rtx = simplify_unary_operation (code, mode, |
696d76a5 MS |
3307 | const_arg0 ? const_arg0 : folded_arg0, |
3308 | mode_arg0); | |
67a37737 | 3309 | } |
7afe21cc | 3310 | break; |
278a83b2 | 3311 | |
ec8e098d PB |
3312 | case RTX_COMPARE: |
3313 | case RTX_COMM_COMPARE: | |
7afe21cc RK |
3314 | /* See what items are actually being compared and set FOLDED_ARG[01] |
3315 | to those values and CODE to the actual comparison code. If any are | |
3316 | constant, set CONST_ARG0 and CONST_ARG1 appropriately. We needn't | |
3317 | do anything if both operands are already known to be constant. */ | |
3318 | ||
21e5076a UB |
3319 | /* ??? Vector mode comparisons are not supported yet. */ |
3320 | if (VECTOR_MODE_P (mode)) | |
3321 | break; | |
3322 | ||
7afe21cc RK |
3323 | if (const_arg0 == 0 || const_arg1 == 0) |
3324 | { | |
3325 | struct table_elt *p0, *p1; | |
9e6a14a4 | 3326 | rtx true_rtx, false_rtx; |
ef4bddc2 | 3327 | machine_mode mode_arg1; |
c610adec | 3328 | |
9b92bf04 | 3329 | if (SCALAR_FLOAT_MODE_P (mode)) |
c610adec | 3330 | { |
9e6a14a4 | 3331 | #ifdef FLOAT_STORE_FLAG_VALUE |
555affd7 | 3332 | true_rtx = (const_double_from_real_value |
68252e27 | 3333 | (FLOAT_STORE_FLAG_VALUE (mode), mode)); |
9e6a14a4 L |
3334 | #else |
3335 | true_rtx = NULL_RTX; | |
3336 | #endif | |
d6edb99e | 3337 | false_rtx = CONST0_RTX (mode); |
c610adec | 3338 | } |
9e6a14a4 L |
3339 | else |
3340 | { | |
3341 | true_rtx = const_true_rtx; | |
3342 | false_rtx = const0_rtx; | |
3343 | } | |
7afe21cc | 3344 | |
13c9910f RS |
3345 | code = find_comparison_args (code, &folded_arg0, &folded_arg1, |
3346 | &mode_arg0, &mode_arg1); | |
7afe21cc | 3347 | |
13c9910f RS |
3348 | /* If the mode is VOIDmode or a MODE_CC mode, we don't know |
3349 | what kinds of things are being compared, so we can't do | |
3350 | anything with this comparison. */ | |
7afe21cc RK |
3351 | |
3352 | if (mode_arg0 == VOIDmode || GET_MODE_CLASS (mode_arg0) == MODE_CC) | |
3353 | break; | |
3354 | ||
75335440 KH |
3355 | const_arg0 = equiv_constant (folded_arg0); |
3356 | const_arg1 = equiv_constant (folded_arg1); | |
3357 | ||
0f41302f MS |
3358 | /* If we do not now have two constants being compared, see |
3359 | if we can nevertheless deduce some things about the | |
3360 | comparison. */ | |
7afe21cc RK |
3361 | if (const_arg0 == 0 || const_arg1 == 0) |
3362 | { | |
08678f51 HPN |
3363 | if (const_arg1 != NULL) |
3364 | { | |
3365 | rtx cheapest_simplification; | |
3366 | int cheapest_cost; | |
3367 | rtx simp_result; | |
3368 | struct table_elt *p; | |
3369 | ||
3370 | /* See if we can find an equivalent of folded_arg0 | |
3371 | that gets us a cheaper expression, possibly a | |
3372 | constant through simplifications. */ | |
3373 | p = lookup (folded_arg0, SAFE_HASH (folded_arg0, mode_arg0), | |
3374 | mode_arg0); | |
b8698a0f | 3375 | |
08678f51 HPN |
3376 | if (p != NULL) |
3377 | { | |
3378 | cheapest_simplification = x; | |
e548c9df | 3379 | cheapest_cost = COST (x, mode); |
08678f51 HPN |
3380 | |
3381 | for (p = p->first_same_value; p != NULL; p = p->next_same_value) | |
3382 | { | |
3383 | int cost; | |
3384 | ||
3385 | /* If the entry isn't valid, skip it. */ | |
3386 | if (! exp_equiv_p (p->exp, p->exp, 1, false)) | |
3387 | continue; | |
3388 | ||
3389 | /* Try to simplify using this equivalence. */ | |
3390 | simp_result | |
3391 | = simplify_relational_operation (code, mode, | |
3392 | mode_arg0, | |
3393 | p->exp, | |
3394 | const_arg1); | |
3395 | ||
3396 | if (simp_result == NULL) | |
3397 | continue; | |
3398 | ||
e548c9df | 3399 | cost = COST (simp_result, mode); |
08678f51 HPN |
3400 | if (cost < cheapest_cost) |
3401 | { | |
3402 | cheapest_cost = cost; | |
3403 | cheapest_simplification = simp_result; | |
3404 | } | |
3405 | } | |
3406 | ||
3407 | /* If we have a cheaper expression now, use that | |
3408 | and try folding it further, from the top. */ | |
3409 | if (cheapest_simplification != x) | |
7903b3e5 JH |
3410 | return fold_rtx (copy_rtx (cheapest_simplification), |
3411 | insn); | |
08678f51 HPN |
3412 | } |
3413 | } | |
3414 | ||
fd13313f JH |
3415 | /* See if the two operands are the same. */ |
3416 | ||
39641489 PB |
3417 | if ((REG_P (folded_arg0) |
3418 | && REG_P (folded_arg1) | |
3419 | && (REG_QTY (REGNO (folded_arg0)) | |
3420 | == REG_QTY (REGNO (folded_arg1)))) | |
fd13313f | 3421 | || ((p0 = lookup (folded_arg0, |
0516f6fe SB |
3422 | SAFE_HASH (folded_arg0, mode_arg0), |
3423 | mode_arg0)) | |
fd13313f | 3424 | && (p1 = lookup (folded_arg1, |
0516f6fe SB |
3425 | SAFE_HASH (folded_arg1, mode_arg0), |
3426 | mode_arg0)) | |
fd13313f | 3427 | && p0->first_same_value == p1->first_same_value)) |
39641489 | 3428 | folded_arg1 = folded_arg0; |
7afe21cc RK |
3429 | |
3430 | /* If FOLDED_ARG0 is a register, see if the comparison we are | |
3431 | doing now is either the same as we did before or the reverse | |
3432 | (we only check the reverse if not floating-point). */ | |
f8cfc6aa | 3433 | else if (REG_P (folded_arg0)) |
7afe21cc | 3434 | { |
30f72379 | 3435 | int qty = REG_QTY (REGNO (folded_arg0)); |
7afe21cc | 3436 | |
1bb98cec DM |
3437 | if (REGNO_QTY_VALID_P (REGNO (folded_arg0))) |
3438 | { | |
3439 | struct qty_table_elem *ent = &qty_table[qty]; | |
3440 | ||
3441 | if ((comparison_dominates_p (ent->comparison_code, code) | |
1eb8759b RH |
3442 | || (! FLOAT_MODE_P (mode_arg0) |
3443 | && comparison_dominates_p (ent->comparison_code, | |
3444 | reverse_condition (code)))) | |
1bb98cec DM |
3445 | && (rtx_equal_p (ent->comparison_const, folded_arg1) |
3446 | || (const_arg1 | |
3447 | && rtx_equal_p (ent->comparison_const, | |
3448 | const_arg1)) | |
f8cfc6aa | 3449 | || (REG_P (folded_arg1) |
1bb98cec | 3450 | && (REG_QTY (REGNO (folded_arg1)) == ent->comparison_qty)))) |
9e6a14a4 L |
3451 | { |
3452 | if (comparison_dominates_p (ent->comparison_code, code)) | |
3453 | { | |
3454 | if (true_rtx) | |
3455 | return true_rtx; | |
3456 | else | |
3457 | break; | |
3458 | } | |
3459 | else | |
3460 | return false_rtx; | |
3461 | } | |
1bb98cec | 3462 | } |
7afe21cc RK |
3463 | } |
3464 | } | |
3465 | } | |
3466 | ||
3467 | /* If we are comparing against zero, see if the first operand is | |
3468 | equivalent to an IOR with a constant. If so, we may be able to | |
3469 | determine the result of this comparison. */ | |
39641489 | 3470 | if (const_arg1 == const0_rtx && !const_arg0) |
7afe21cc RK |
3471 | { |
3472 | rtx y = lookup_as_function (folded_arg0, IOR); | |
3473 | rtx inner_const; | |
3474 | ||
3475 | if (y != 0 | |
3476 | && (inner_const = equiv_constant (XEXP (y, 1))) != 0 | |
481683e1 | 3477 | && CONST_INT_P (inner_const) |
7afe21cc | 3478 | && INTVAL (inner_const) != 0) |
39641489 | 3479 | folded_arg0 = gen_rtx_IOR (mode_arg0, XEXP (y, 0), inner_const); |
7afe21cc RK |
3480 | } |
3481 | ||
c6fb08ad | 3482 | { |
bca3cc97 JJ |
3483 | rtx op0 = const_arg0 ? const_arg0 : copy_rtx (folded_arg0); |
3484 | rtx op1 = const_arg1 ? const_arg1 : copy_rtx (folded_arg1); | |
3485 | new_rtx = simplify_relational_operation (code, mode, mode_arg0, | |
3486 | op0, op1); | |
c6fb08ad | 3487 | } |
7afe21cc RK |
3488 | break; |
3489 | ||
ec8e098d PB |
3490 | case RTX_BIN_ARITH: |
3491 | case RTX_COMM_ARITH: | |
7afe21cc RK |
3492 | switch (code) |
3493 | { | |
3494 | case PLUS: | |
3495 | /* If the second operand is a LABEL_REF, see if the first is a MINUS | |
3496 | with that LABEL_REF as its second operand. If so, the result is | |
3497 | the first operand of that MINUS. This handles switches with an | |
3498 | ADDR_DIFF_VEC table. */ | |
3499 | if (const_arg1 && GET_CODE (const_arg1) == LABEL_REF) | |
3500 | { | |
e650cbda RK |
3501 | rtx y |
3502 | = GET_CODE (folded_arg0) == MINUS ? folded_arg0 | |
ddc356e8 | 3503 | : lookup_as_function (folded_arg0, MINUS); |
7afe21cc RK |
3504 | |
3505 | if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF | |
04a121a7 | 3506 | && label_ref_label (XEXP (y, 1)) == label_ref_label (const_arg1)) |
7afe21cc | 3507 | return XEXP (y, 0); |
67a37737 RK |
3508 | |
3509 | /* Now try for a CONST of a MINUS like the above. */ | |
e650cbda RK |
3510 | if ((y = (GET_CODE (folded_arg0) == CONST ? folded_arg0 |
3511 | : lookup_as_function (folded_arg0, CONST))) != 0 | |
67a37737 RK |
3512 | && GET_CODE (XEXP (y, 0)) == MINUS |
3513 | && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF | |
04a121a7 | 3514 | && label_ref_label (XEXP (XEXP (y, 0), 1)) == label_ref_label (const_arg1)) |
67a37737 | 3515 | return XEXP (XEXP (y, 0), 0); |
7afe21cc | 3516 | } |
c2cc0778 | 3517 | |
e650cbda RK |
3518 | /* Likewise if the operands are in the other order. */ |
3519 | if (const_arg0 && GET_CODE (const_arg0) == LABEL_REF) | |
3520 | { | |
3521 | rtx y | |
3522 | = GET_CODE (folded_arg1) == MINUS ? folded_arg1 | |
ddc356e8 | 3523 | : lookup_as_function (folded_arg1, MINUS); |
e650cbda RK |
3524 | |
3525 | if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF | |
04a121a7 | 3526 | && label_ref_label (XEXP (y, 1)) == label_ref_label (const_arg0)) |
e650cbda RK |
3527 | return XEXP (y, 0); |
3528 | ||
3529 | /* Now try for a CONST of a MINUS like the above. */ | |
3530 | if ((y = (GET_CODE (folded_arg1) == CONST ? folded_arg1 | |
3531 | : lookup_as_function (folded_arg1, CONST))) != 0 | |
3532 | && GET_CODE (XEXP (y, 0)) == MINUS | |
3533 | && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF | |
04a121a7 | 3534 | && label_ref_label (XEXP (XEXP (y, 0), 1)) == label_ref_label (const_arg0)) |
e650cbda RK |
3535 | return XEXP (XEXP (y, 0), 0); |
3536 | } | |
3537 | ||
c2cc0778 RK |
3538 | /* If second operand is a register equivalent to a negative |
3539 | CONST_INT, see if we can find a register equivalent to the | |
3540 | positive constant. Make a MINUS if so. Don't do this for | |
5d595063 | 3541 | a non-negative constant since we might then alternate between |
a1f300c0 | 3542 | choosing positive and negative constants. Having the positive |
5d595063 RK |
3543 | constant previously-used is the more common case. Be sure |
3544 | the resulting constant is non-negative; if const_arg1 were | |
3545 | the smallest negative number this would overflow: depending | |
3546 | on the mode, this would either just be the same value (and | |
3547 | hence not save anything) or be incorrect. */ | |
481683e1 | 3548 | if (const_arg1 != 0 && CONST_INT_P (const_arg1) |
5d595063 | 3549 | && INTVAL (const_arg1) < 0 |
4741f6ad JL |
3550 | /* This used to test |
3551 | ||
ddc356e8 | 3552 | -INTVAL (const_arg1) >= 0 |
4741f6ad JL |
3553 | |
3554 | But The Sun V5.0 compilers mis-compiled that test. So | |
3555 | instead we test for the problematic value in a more direct | |
3556 | manner and hope the Sun compilers get it correct. */ | |
5c45a8ac | 3557 | && INTVAL (const_arg1) != |
fecfbfa4 | 3558 | (HOST_WIDE_INT_1 << (HOST_BITS_PER_WIDE_INT - 1)) |
f8cfc6aa | 3559 | && REG_P (folded_arg1)) |
c2cc0778 | 3560 | { |
ddc356e8 | 3561 | rtx new_const = GEN_INT (-INTVAL (const_arg1)); |
c2cc0778 | 3562 | struct table_elt *p |
0516f6fe | 3563 | = lookup (new_const, SAFE_HASH (new_const, mode), mode); |
c2cc0778 RK |
3564 | |
3565 | if (p) | |
3566 | for (p = p->first_same_value; p; p = p->next_same_value) | |
f8cfc6aa | 3567 | if (REG_P (p->exp)) |
0cedb36c | 3568 | return simplify_gen_binary (MINUS, mode, folded_arg0, |
20468884 | 3569 | canon_reg (p->exp, NULL)); |
c2cc0778 | 3570 | } |
13c9910f RS |
3571 | goto from_plus; |
3572 | ||
3573 | case MINUS: | |
3574 | /* If we have (MINUS Y C), see if Y is known to be (PLUS Z C2). | |
3575 | If so, produce (PLUS Z C2-C). */ | |
481683e1 | 3576 | if (const_arg1 != 0 && CONST_INT_P (const_arg1)) |
13c9910f RS |
3577 | { |
3578 | rtx y = lookup_as_function (XEXP (x, 0), PLUS); | |
481683e1 | 3579 | if (y && CONST_INT_P (XEXP (y, 1))) |
0a81f074 | 3580 | return fold_rtx (plus_constant (mode, copy_rtx (y), |
f3becefd | 3581 | -INTVAL (const_arg1)), |
20468884 | 3582 | NULL); |
13c9910f | 3583 | } |
7afe21cc | 3584 | |
ddc356e8 | 3585 | /* Fall through. */ |
7afe21cc | 3586 | |
13c9910f | 3587 | from_plus: |
7afe21cc RK |
3588 | case SMIN: case SMAX: case UMIN: case UMAX: |
3589 | case IOR: case AND: case XOR: | |
f930bfd0 | 3590 | case MULT: |
7afe21cc RK |
3591 | case ASHIFT: case LSHIFTRT: case ASHIFTRT: |
3592 | /* If we have (<op> <reg> <const_int>) for an associative OP and REG | |
3593 | is known to be of similar form, we may be able to replace the | |
3594 | operation with a combined operation. This may eliminate the | |
3595 | intermediate operation if every use is simplified in this way. | |
3596 | Note that the similar optimization done by combine.c only works | |
3597 | if the intermediate operation's result has only one reference. */ | |
3598 | ||
f8cfc6aa | 3599 | if (REG_P (folded_arg0) |
481683e1 | 3600 | && const_arg1 && CONST_INT_P (const_arg1)) |
7afe21cc RK |
3601 | { |
3602 | int is_shift | |
3603 | = (code == ASHIFT || code == ASHIFTRT || code == LSHIFTRT); | |
5bb51e1d | 3604 | rtx y, inner_const, new_const; |
39b2ac74 | 3605 | rtx canon_const_arg1 = const_arg1; |
7afe21cc | 3606 | enum rtx_code associate_code; |
7afe21cc | 3607 | |
824a4527 | 3608 | if (is_shift |
5511bc5a | 3609 | && (INTVAL (const_arg1) >= GET_MODE_PRECISION (mode) |
824a4527 JDA |
3610 | || INTVAL (const_arg1) < 0)) |
3611 | { | |
3612 | if (SHIFT_COUNT_TRUNCATED) | |
39b2ac74 JJ |
3613 | canon_const_arg1 = GEN_INT (INTVAL (const_arg1) |
3614 | & (GET_MODE_BITSIZE (mode) | |
3615 | - 1)); | |
824a4527 JDA |
3616 | else |
3617 | break; | |
3618 | } | |
3619 | ||
5bb51e1d | 3620 | y = lookup_as_function (folded_arg0, code); |
824a4527 JDA |
3621 | if (y == 0) |
3622 | break; | |
824a4527 JDA |
3623 | |
3624 | /* If we have compiled a statement like | |
3625 | "if (x == (x & mask1))", and now are looking at | |
3626 | "x & mask2", we will have a case where the first operand | |
3627 | of Y is the same as our first operand. Unless we detect | |
3628 | this case, an infinite loop will result. */ | |
3629 | if (XEXP (y, 0) == folded_arg0) | |
7afe21cc RK |
3630 | break; |
3631 | ||
5bb51e1d | 3632 | inner_const = equiv_constant (fold_rtx (XEXP (y, 1), 0)); |
481683e1 | 3633 | if (!inner_const || !CONST_INT_P (inner_const)) |
5bb51e1d EB |
3634 | break; |
3635 | ||
7afe21cc RK |
3636 | /* Don't associate these operations if they are a PLUS with the |
3637 | same constant and it is a power of two. These might be doable | |
3638 | with a pre- or post-increment. Similarly for two subtracts of | |
3639 | identical powers of two with post decrement. */ | |
3640 | ||
213d5fbc | 3641 | if (code == PLUS && const_arg1 == inner_const |
940da324 | 3642 | && ((HAVE_PRE_INCREMENT |
146ec50f | 3643 | && pow2p_hwi (INTVAL (const_arg1))) |
940da324 | 3644 | || (HAVE_POST_INCREMENT |
146ec50f | 3645 | && pow2p_hwi (INTVAL (const_arg1))) |
940da324 | 3646 | || (HAVE_PRE_DECREMENT |
146ec50f | 3647 | && pow2p_hwi (- INTVAL (const_arg1))) |
940da324 | 3648 | || (HAVE_POST_DECREMENT |
146ec50f | 3649 | && pow2p_hwi (- INTVAL (const_arg1))))) |
7afe21cc RK |
3650 | break; |
3651 | ||
88057dc8 UB |
3652 | /* ??? Vector mode shifts by scalar |
3653 | shift operand are not supported yet. */ | |
3654 | if (is_shift && VECTOR_MODE_P (mode)) | |
3655 | break; | |
3656 | ||
824a4527 | 3657 | if (is_shift |
5511bc5a | 3658 | && (INTVAL (inner_const) >= GET_MODE_PRECISION (mode) |
824a4527 JDA |
3659 | || INTVAL (inner_const) < 0)) |
3660 | { | |
3661 | if (SHIFT_COUNT_TRUNCATED) | |
3662 | inner_const = GEN_INT (INTVAL (inner_const) | |
3663 | & (GET_MODE_BITSIZE (mode) - 1)); | |
3664 | else | |
3665 | break; | |
3666 | } | |
3667 | ||
7afe21cc | 3668 | /* Compute the code used to compose the constants. For example, |
f930bfd0 | 3669 | A-C1-C2 is A-(C1 + C2), so if CODE == MINUS, we want PLUS. */ |
7afe21cc | 3670 | |
f930bfd0 | 3671 | associate_code = (is_shift || code == MINUS ? PLUS : code); |
7afe21cc RK |
3672 | |
3673 | new_const = simplify_binary_operation (associate_code, mode, | |
39b2ac74 JJ |
3674 | canon_const_arg1, |
3675 | inner_const); | |
7afe21cc RK |
3676 | |
3677 | if (new_const == 0) | |
3678 | break; | |
3679 | ||
3680 | /* If we are associating shift operations, don't let this | |
4908e508 RS |
3681 | produce a shift of the size of the object or larger. |
3682 | This could occur when we follow a sign-extend by a right | |
3683 | shift on a machine that does a sign-extend as a pair | |
3684 | of shifts. */ | |
7afe21cc | 3685 | |
824a4527 | 3686 | if (is_shift |
481683e1 | 3687 | && CONST_INT_P (new_const) |
5511bc5a | 3688 | && INTVAL (new_const) >= GET_MODE_PRECISION (mode)) |
4908e508 RS |
3689 | { |
3690 | /* As an exception, we can turn an ASHIFTRT of this | |
3691 | form into a shift of the number of bits - 1. */ | |
3692 | if (code == ASHIFTRT) | |
3693 | new_const = GEN_INT (GET_MODE_BITSIZE (mode) - 1); | |
824a4527 JDA |
3694 | else if (!side_effects_p (XEXP (y, 0))) |
3695 | return CONST0_RTX (mode); | |
4908e508 RS |
3696 | else |
3697 | break; | |
3698 | } | |
7afe21cc RK |
3699 | |
3700 | y = copy_rtx (XEXP (y, 0)); | |
3701 | ||
3702 | /* If Y contains our first operand (the most common way this | |
3703 | can happen is if Y is a MEM), we would do into an infinite | |
3704 | loop if we tried to fold it. So don't in that case. */ | |
3705 | ||
3706 | if (! reg_mentioned_p (folded_arg0, y)) | |
3707 | y = fold_rtx (y, insn); | |
3708 | ||
0cedb36c | 3709 | return simplify_gen_binary (code, mode, y, new_const); |
7afe21cc | 3710 | } |
e9a25f70 JL |
3711 | break; |
3712 | ||
f930bfd0 JW |
3713 | case DIV: case UDIV: |
3714 | /* ??? The associative optimization performed immediately above is | |
3715 | also possible for DIV and UDIV using associate_code of MULT. | |
3716 | However, we would need extra code to verify that the | |
3717 | multiplication does not overflow, that is, there is no overflow | |
3718 | in the calculation of new_const. */ | |
3719 | break; | |
3720 | ||
e9a25f70 JL |
3721 | default: |
3722 | break; | |
7afe21cc RK |
3723 | } |
3724 | ||
32e9fa48 | 3725 | new_rtx = simplify_binary_operation (code, mode, |
7afe21cc RK |
3726 | const_arg0 ? const_arg0 : folded_arg0, |
3727 | const_arg1 ? const_arg1 : folded_arg1); | |
3728 | break; | |
3729 | ||
ec8e098d | 3730 | case RTX_OBJ: |
7afe21cc RK |
3731 | /* (lo_sum (high X) X) is simply X. */ |
3732 | if (code == LO_SUM && const_arg0 != 0 | |
3733 | && GET_CODE (const_arg0) == HIGH | |
3734 | && rtx_equal_p (XEXP (const_arg0, 0), const_arg1)) | |
3735 | return const_arg1; | |
3736 | break; | |
3737 | ||
ec8e098d PB |
3738 | case RTX_TERNARY: |
3739 | case RTX_BITFIELD_OPS: | |
32e9fa48 | 3740 | new_rtx = simplify_ternary_operation (code, mode, mode_arg0, |
7afe21cc RK |
3741 | const_arg0 ? const_arg0 : folded_arg0, |
3742 | const_arg1 ? const_arg1 : folded_arg1, | |
3743 | const_arg2 ? const_arg2 : XEXP (x, 2)); | |
3744 | break; | |
ee5332b8 | 3745 | |
ec8e098d PB |
3746 | default: |
3747 | break; | |
7afe21cc RK |
3748 | } |
3749 | ||
32e9fa48 | 3750 | return new_rtx ? new_rtx : x; |
7afe21cc RK |
3751 | } |
3752 | \f | |
3753 | /* Return a constant value currently equivalent to X. | |
3754 | Return 0 if we don't know one. */ | |
3755 | ||
3756 | static rtx | |
7080f735 | 3757 | equiv_constant (rtx x) |
7afe21cc | 3758 | { |
f8cfc6aa | 3759 | if (REG_P (x) |
1bb98cec DM |
3760 | && REGNO_QTY_VALID_P (REGNO (x))) |
3761 | { | |
3762 | int x_q = REG_QTY (REGNO (x)); | |
3763 | struct qty_table_elem *x_ent = &qty_table[x_q]; | |
3764 | ||
3765 | if (x_ent->const_rtx) | |
4de249d9 | 3766 | x = gen_lowpart (GET_MODE (x), x_ent->const_rtx); |
1bb98cec | 3767 | } |
7afe21cc | 3768 | |
2ce5e1b4 | 3769 | if (x == 0 || CONSTANT_P (x)) |
7afe21cc RK |
3770 | return x; |
3771 | ||
a52b023a PB |
3772 | if (GET_CODE (x) == SUBREG) |
3773 | { | |
ef4bddc2 RS |
3774 | machine_mode mode = GET_MODE (x); |
3775 | machine_mode imode = GET_MODE (SUBREG_REG (x)); | |
32e9fa48 | 3776 | rtx new_rtx; |
a52b023a PB |
3777 | |
3778 | /* See if we previously assigned a constant value to this SUBREG. */ | |
32e9fa48 | 3779 | if ((new_rtx = lookup_as_function (x, CONST_INT)) != 0 |
807e902e | 3780 | || (new_rtx = lookup_as_function (x, CONST_WIDE_INT)) != 0 |
32e9fa48 KG |
3781 | || (new_rtx = lookup_as_function (x, CONST_DOUBLE)) != 0 |
3782 | || (new_rtx = lookup_as_function (x, CONST_FIXED)) != 0) | |
3783 | return new_rtx; | |
a52b023a | 3784 | |
f5f8d79d EB |
3785 | /* If we didn't and if doing so makes sense, see if we previously |
3786 | assigned a constant value to the enclosing word mode SUBREG. */ | |
3787 | if (GET_MODE_SIZE (mode) < GET_MODE_SIZE (word_mode) | |
3788 | && GET_MODE_SIZE (word_mode) < GET_MODE_SIZE (imode)) | |
3789 | { | |
3790 | int byte = SUBREG_BYTE (x) - subreg_lowpart_offset (mode, word_mode); | |
3791 | if (byte >= 0 && (byte % UNITS_PER_WORD) == 0) | |
3792 | { | |
3793 | rtx y = gen_rtx_SUBREG (word_mode, SUBREG_REG (x), byte); | |
3794 | new_rtx = lookup_as_function (y, CONST_INT); | |
3795 | if (new_rtx) | |
3796 | return gen_lowpart (mode, new_rtx); | |
3797 | } | |
3798 | } | |
3799 | ||
7cb6668a MI |
3800 | /* Otherwise see if we already have a constant for the inner REG, |
3801 | and if that is enough to calculate an equivalent constant for | |
3802 | the subreg. Note that the upper bits of paradoxical subregs | |
3803 | are undefined, so they cannot be said to equal anything. */ | |
a52b023a | 3804 | if (REG_P (SUBREG_REG (x)) |
03a95621 | 3805 | && !paradoxical_subreg_p (x) |
32e9fa48 | 3806 | && (new_rtx = equiv_constant (SUBREG_REG (x))) != 0) |
f5f8d79d | 3807 | return simplify_subreg (mode, new_rtx, imode, SUBREG_BYTE (x)); |
a52b023a PB |
3808 | |
3809 | return 0; | |
3810 | } | |
3811 | ||
3812 | /* If X is a MEM, see if it is a constant-pool reference, or look it up in | |
3813 | the hash table in case its value was seen before. */ | |
fc3ffe83 | 3814 | |
3c0cb5de | 3815 | if (MEM_P (x)) |
fc3ffe83 RK |
3816 | { |
3817 | struct table_elt *elt; | |
3818 | ||
a52b023a | 3819 | x = avoid_constant_pool_reference (x); |
fc3ffe83 RK |
3820 | if (CONSTANT_P (x)) |
3821 | return x; | |
3822 | ||
0516f6fe | 3823 | elt = lookup (x, SAFE_HASH (x, GET_MODE (x)), GET_MODE (x)); |
fc3ffe83 RK |
3824 | if (elt == 0) |
3825 | return 0; | |
3826 | ||
3827 | for (elt = elt->first_same_value; elt; elt = elt->next_same_value) | |
3828 | if (elt->is_const && CONSTANT_P (elt->exp)) | |
3829 | return elt->exp; | |
3830 | } | |
3831 | ||
7afe21cc RK |
3832 | return 0; |
3833 | } | |
3834 | \f | |
0129d079 SB |
3835 | /* Given INSN, a jump insn, TAKEN indicates if we are following the |
3836 | "taken" branch. | |
7afe21cc RK |
3837 | |
3838 | In certain cases, this can cause us to add an equivalence. For example, | |
278a83b2 | 3839 | if we are following the taken case of |
7080f735 | 3840 | if (i == 2) |
7afe21cc RK |
3841 | we can add the fact that `i' and '2' are now equivalent. |
3842 | ||
3843 | In any case, we can record that this comparison was passed. If the same | |
3844 | comparison is seen later, we will know its value. */ | |
3845 | ||
3846 | static void | |
20468884 | 3847 | record_jump_equiv (rtx_insn *insn, bool taken) |
7afe21cc RK |
3848 | { |
3849 | int cond_known_true; | |
3850 | rtx op0, op1; | |
7f1c097d | 3851 | rtx set; |
ef4bddc2 | 3852 | machine_mode mode, mode0, mode1; |
7afe21cc RK |
3853 | int reversed_nonequality = 0; |
3854 | enum rtx_code code; | |
3855 | ||
3856 | /* Ensure this is the right kind of insn. */ | |
0129d079 SB |
3857 | gcc_assert (any_condjump_p (insn)); |
3858 | ||
7f1c097d | 3859 | set = pc_set (insn); |
7afe21cc RK |
3860 | |
3861 | /* See if this jump condition is known true or false. */ | |
3862 | if (taken) | |
7f1c097d | 3863 | cond_known_true = (XEXP (SET_SRC (set), 2) == pc_rtx); |
7afe21cc | 3864 | else |
7f1c097d | 3865 | cond_known_true = (XEXP (SET_SRC (set), 1) == pc_rtx); |
7afe21cc RK |
3866 | |
3867 | /* Get the type of comparison being done and the operands being compared. | |
3868 | If we had to reverse a non-equality condition, record that fact so we | |
3869 | know that it isn't valid for floating-point. */ | |
7f1c097d JH |
3870 | code = GET_CODE (XEXP (SET_SRC (set), 0)); |
3871 | op0 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 0), insn); | |
3872 | op1 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 1), insn); | |
7afe21cc | 3873 | |
3f1d32a5 JL |
3874 | /* On a cc0 target the cc0-setter and cc0-user may end up in different |
3875 | blocks. When that happens the tracking of the cc0-setter via | |
3876 | PREV_INSN_CC0 is spoiled. That means that fold_rtx may return | |
3877 | NULL_RTX. In those cases, there's nothing to record. */ | |
3878 | if (op0 == NULL_RTX || op1 == NULL_RTX) | |
3879 | return; | |
3880 | ||
13c9910f | 3881 | code = find_comparison_args (code, &op0, &op1, &mode0, &mode1); |
7afe21cc RK |
3882 | if (! cond_known_true) |
3883 | { | |
261efdef | 3884 | code = reversed_comparison_code_parts (code, op0, op1, insn); |
1eb8759b RH |
3885 | |
3886 | /* Don't remember if we can't find the inverse. */ | |
3887 | if (code == UNKNOWN) | |
3888 | return; | |
7afe21cc RK |
3889 | } |
3890 | ||
3891 | /* The mode is the mode of the non-constant. */ | |
13c9910f RS |
3892 | mode = mode0; |
3893 | if (mode1 != VOIDmode) | |
3894 | mode = mode1; | |
7afe21cc RK |
3895 | |
3896 | record_jump_cond (code, mode, op0, op1, reversed_nonequality); | |
3897 | } | |
3898 | ||
794693c0 RH |
3899 | /* Yet another form of subreg creation. In this case, we want something in |
3900 | MODE, and we should assume OP has MODE iff it is naturally modeless. */ | |
3901 | ||
3902 | static rtx | |
ef4bddc2 | 3903 | record_jump_cond_subreg (machine_mode mode, rtx op) |
794693c0 | 3904 | { |
ef4bddc2 | 3905 | machine_mode op_mode = GET_MODE (op); |
794693c0 RH |
3906 | if (op_mode == mode || op_mode == VOIDmode) |
3907 | return op; | |
3908 | return lowpart_subreg (mode, op, op_mode); | |
3909 | } | |
3910 | ||
7afe21cc RK |
3911 | /* We know that comparison CODE applied to OP0 and OP1 in MODE is true. |
3912 | REVERSED_NONEQUALITY is nonzero if CODE had to be swapped. | |
3913 | Make any useful entries we can with that information. Called from | |
3914 | above function and called recursively. */ | |
3915 | ||
3916 | static void | |
ef4bddc2 | 3917 | record_jump_cond (enum rtx_code code, machine_mode mode, rtx op0, |
7080f735 | 3918 | rtx op1, int reversed_nonequality) |
7afe21cc | 3919 | { |
2197a88a | 3920 | unsigned op0_hash, op1_hash; |
e428d738 | 3921 | int op0_in_memory, op1_in_memory; |
7afe21cc RK |
3922 | struct table_elt *op0_elt, *op1_elt; |
3923 | ||
3924 | /* If OP0 and OP1 are known equal, and either is a paradoxical SUBREG, | |
3925 | we know that they are also equal in the smaller mode (this is also | |
3926 | true for all smaller modes whether or not there is a SUBREG, but | |
ac7ef8d5 | 3927 | is not worth testing for with no SUBREG). */ |
7afe21cc | 3928 | |
2e794ee8 | 3929 | /* Note that GET_MODE (op0) may not equal MODE. */ |
6a4bdc79 | 3930 | if (code == EQ && paradoxical_subreg_p (op0)) |
7afe21cc | 3931 | { |
ef4bddc2 | 3932 | machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); |
794693c0 RH |
3933 | rtx tem = record_jump_cond_subreg (inner_mode, op1); |
3934 | if (tem) | |
3935 | record_jump_cond (code, mode, SUBREG_REG (op0), tem, | |
3936 | reversed_nonequality); | |
7afe21cc RK |
3937 | } |
3938 | ||
6a4bdc79 | 3939 | if (code == EQ && paradoxical_subreg_p (op1)) |
7afe21cc | 3940 | { |
ef4bddc2 | 3941 | machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); |
794693c0 RH |
3942 | rtx tem = record_jump_cond_subreg (inner_mode, op0); |
3943 | if (tem) | |
3944 | record_jump_cond (code, mode, SUBREG_REG (op1), tem, | |
3945 | reversed_nonequality); | |
7afe21cc RK |
3946 | } |
3947 | ||
278a83b2 | 3948 | /* Similarly, if this is an NE comparison, and either is a SUBREG |
7afe21cc RK |
3949 | making a smaller mode, we know the whole thing is also NE. */ |
3950 | ||
2e794ee8 RS |
3951 | /* Note that GET_MODE (op0) may not equal MODE; |
3952 | if we test MODE instead, we can get an infinite recursion | |
3953 | alternating between two modes each wider than MODE. */ | |
3954 | ||
7afe21cc RK |
3955 | if (code == NE && GET_CODE (op0) == SUBREG |
3956 | && subreg_lowpart_p (op0) | |
2e794ee8 RS |
3957 | && (GET_MODE_SIZE (GET_MODE (op0)) |
3958 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) | |
7afe21cc | 3959 | { |
ef4bddc2 | 3960 | machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); |
794693c0 RH |
3961 | rtx tem = record_jump_cond_subreg (inner_mode, op1); |
3962 | if (tem) | |
3963 | record_jump_cond (code, mode, SUBREG_REG (op0), tem, | |
3964 | reversed_nonequality); | |
7afe21cc RK |
3965 | } |
3966 | ||
3967 | if (code == NE && GET_CODE (op1) == SUBREG | |
3968 | && subreg_lowpart_p (op1) | |
2e794ee8 RS |
3969 | && (GET_MODE_SIZE (GET_MODE (op1)) |
3970 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) | |
7afe21cc | 3971 | { |
ef4bddc2 | 3972 | machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); |
794693c0 RH |
3973 | rtx tem = record_jump_cond_subreg (inner_mode, op0); |
3974 | if (tem) | |
3975 | record_jump_cond (code, mode, SUBREG_REG (op1), tem, | |
3976 | reversed_nonequality); | |
7afe21cc RK |
3977 | } |
3978 | ||
3979 | /* Hash both operands. */ | |
3980 | ||
3981 | do_not_record = 0; | |
3982 | hash_arg_in_memory = 0; | |
2197a88a | 3983 | op0_hash = HASH (op0, mode); |
7afe21cc | 3984 | op0_in_memory = hash_arg_in_memory; |
7afe21cc RK |
3985 | |
3986 | if (do_not_record) | |
3987 | return; | |
3988 | ||
3989 | do_not_record = 0; | |
3990 | hash_arg_in_memory = 0; | |
2197a88a | 3991 | op1_hash = HASH (op1, mode); |
7afe21cc | 3992 | op1_in_memory = hash_arg_in_memory; |
278a83b2 | 3993 | |
7afe21cc RK |
3994 | if (do_not_record) |
3995 | return; | |
3996 | ||
3997 | /* Look up both operands. */ | |
2197a88a RK |
3998 | op0_elt = lookup (op0, op0_hash, mode); |
3999 | op1_elt = lookup (op1, op1_hash, mode); | |
7afe21cc | 4000 | |
af3869c1 RK |
4001 | /* If both operands are already equivalent or if they are not in the |
4002 | table but are identical, do nothing. */ | |
4003 | if ((op0_elt != 0 && op1_elt != 0 | |
4004 | && op0_elt->first_same_value == op1_elt->first_same_value) | |
4005 | || op0 == op1 || rtx_equal_p (op0, op1)) | |
4006 | return; | |
4007 | ||
7afe21cc | 4008 | /* If we aren't setting two things equal all we can do is save this |
b2796a4b RK |
4009 | comparison. Similarly if this is floating-point. In the latter |
4010 | case, OP1 might be zero and both -0.0 and 0.0 are equal to it. | |
4011 | If we record the equality, we might inadvertently delete code | |
4012 | whose intent was to change -0 to +0. */ | |
4013 | ||
cbf6a543 | 4014 | if (code != EQ || FLOAT_MODE_P (GET_MODE (op0))) |
7afe21cc | 4015 | { |
1bb98cec DM |
4016 | struct qty_table_elem *ent; |
4017 | int qty; | |
4018 | ||
7afe21cc RK |
4019 | /* If we reversed a floating-point comparison, if OP0 is not a |
4020 | register, or if OP1 is neither a register or constant, we can't | |
4021 | do anything. */ | |
4022 | ||
f8cfc6aa | 4023 | if (!REG_P (op1)) |
7afe21cc RK |
4024 | op1 = equiv_constant (op1); |
4025 | ||
cbf6a543 | 4026 | if ((reversed_nonequality && FLOAT_MODE_P (mode)) |
f8cfc6aa | 4027 | || !REG_P (op0) || op1 == 0) |
7afe21cc RK |
4028 | return; |
4029 | ||
4030 | /* Put OP0 in the hash table if it isn't already. This gives it a | |
4031 | new quantity number. */ | |
4032 | if (op0_elt == 0) | |
4033 | { | |
9714cf43 | 4034 | if (insert_regs (op0, NULL, 0)) |
7afe21cc RK |
4035 | { |
4036 | rehash_using_reg (op0); | |
2197a88a | 4037 | op0_hash = HASH (op0, mode); |
2bb81c86 RK |
4038 | |
4039 | /* If OP0 is contained in OP1, this changes its hash code | |
4040 | as well. Faster to rehash than to check, except | |
4041 | for the simple case of a constant. */ | |
4042 | if (! CONSTANT_P (op1)) | |
2197a88a | 4043 | op1_hash = HASH (op1,mode); |
7afe21cc RK |
4044 | } |
4045 | ||
9714cf43 | 4046 | op0_elt = insert (op0, NULL, op0_hash, mode); |
7afe21cc | 4047 | op0_elt->in_memory = op0_in_memory; |
7afe21cc RK |
4048 | } |
4049 | ||
1bb98cec DM |
4050 | qty = REG_QTY (REGNO (op0)); |
4051 | ent = &qty_table[qty]; | |
4052 | ||
4053 | ent->comparison_code = code; | |
f8cfc6aa | 4054 | if (REG_P (op1)) |
7afe21cc | 4055 | { |
5d5ea909 | 4056 | /* Look it up again--in case op0 and op1 are the same. */ |
2197a88a | 4057 | op1_elt = lookup (op1, op1_hash, mode); |
5d5ea909 | 4058 | |
7afe21cc RK |
4059 | /* Put OP1 in the hash table so it gets a new quantity number. */ |
4060 | if (op1_elt == 0) | |
4061 | { | |
9714cf43 | 4062 | if (insert_regs (op1, NULL, 0)) |
7afe21cc RK |
4063 | { |
4064 | rehash_using_reg (op1); | |
2197a88a | 4065 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
4066 | } |
4067 | ||
9714cf43 | 4068 | op1_elt = insert (op1, NULL, op1_hash, mode); |
7afe21cc | 4069 | op1_elt->in_memory = op1_in_memory; |
7afe21cc RK |
4070 | } |
4071 | ||
1bb98cec DM |
4072 | ent->comparison_const = NULL_RTX; |
4073 | ent->comparison_qty = REG_QTY (REGNO (op1)); | |
7afe21cc RK |
4074 | } |
4075 | else | |
4076 | { | |
1bb98cec DM |
4077 | ent->comparison_const = op1; |
4078 | ent->comparison_qty = -1; | |
7afe21cc RK |
4079 | } |
4080 | ||
4081 | return; | |
4082 | } | |
4083 | ||
eb5ad42a RS |
4084 | /* If either side is still missing an equivalence, make it now, |
4085 | then merge the equivalences. */ | |
7afe21cc | 4086 | |
7afe21cc RK |
4087 | if (op0_elt == 0) |
4088 | { | |
9714cf43 | 4089 | if (insert_regs (op0, NULL, 0)) |
7afe21cc RK |
4090 | { |
4091 | rehash_using_reg (op0); | |
2197a88a | 4092 | op0_hash = HASH (op0, mode); |
7afe21cc RK |
4093 | } |
4094 | ||
9714cf43 | 4095 | op0_elt = insert (op0, NULL, op0_hash, mode); |
7afe21cc | 4096 | op0_elt->in_memory = op0_in_memory; |
7afe21cc RK |
4097 | } |
4098 | ||
4099 | if (op1_elt == 0) | |
4100 | { | |
9714cf43 | 4101 | if (insert_regs (op1, NULL, 0)) |
7afe21cc RK |
4102 | { |
4103 | rehash_using_reg (op1); | |
2197a88a | 4104 | op1_hash = HASH (op1, mode); |
7afe21cc RK |
4105 | } |
4106 | ||
9714cf43 | 4107 | op1_elt = insert (op1, NULL, op1_hash, mode); |
7afe21cc | 4108 | op1_elt->in_memory = op1_in_memory; |
7afe21cc | 4109 | } |
eb5ad42a RS |
4110 | |
4111 | merge_equiv_classes (op0_elt, op1_elt); | |
7afe21cc RK |
4112 | } |
4113 | \f | |
4114 | /* CSE processing for one instruction. | |
7b02f4e0 SB |
4115 | |
4116 | Most "true" common subexpressions are mostly optimized away in GIMPLE, | |
4117 | but the few that "leak through" are cleaned up by cse_insn, and complex | |
4118 | addressing modes are often formed here. | |
4119 | ||
4120 | The main function is cse_insn, and between here and that function | |
4121 | a couple of helper functions is defined to keep the size of cse_insn | |
4122 | within reasonable proportions. | |
4123 | ||
4124 | Data is shared between the main and helper functions via STRUCT SET, | |
4125 | that contains all data related for every set in the instruction that | |
4126 | is being processed. | |
4127 | ||
4128 | Note that cse_main processes all sets in the instruction. Most | |
4129 | passes in GCC only process simple SET insns or single_set insns, but | |
4130 | CSE processes insns with multiple sets as well. */ | |
7afe21cc RK |
4131 | |
4132 | /* Data on one SET contained in the instruction. */ | |
4133 | ||
4134 | struct set | |
4135 | { | |
4136 | /* The SET rtx itself. */ | |
4137 | rtx rtl; | |
4138 | /* The SET_SRC of the rtx (the original value, if it is changing). */ | |
4139 | rtx src; | |
4140 | /* The hash-table element for the SET_SRC of the SET. */ | |
4141 | struct table_elt *src_elt; | |
2197a88a RK |
4142 | /* Hash value for the SET_SRC. */ |
4143 | unsigned src_hash; | |
4144 | /* Hash value for the SET_DEST. */ | |
4145 | unsigned dest_hash; | |
7afe21cc RK |
4146 | /* The SET_DEST, with SUBREG, etc., stripped. */ |
4147 | rtx inner_dest; | |
278a83b2 | 4148 | /* Nonzero if the SET_SRC is in memory. */ |
7afe21cc | 4149 | char src_in_memory; |
7afe21cc RK |
4150 | /* Nonzero if the SET_SRC contains something |
4151 | whose value cannot be predicted and understood. */ | |
4152 | char src_volatile; | |
496324d0 DN |
4153 | /* Original machine mode, in case it becomes a CONST_INT. |
4154 | The size of this field should match the size of the mode | |
4155 | field of struct rtx_def (see rtl.h). */ | |
4156 | ENUM_BITFIELD(machine_mode) mode : 8; | |
2197a88a RK |
4157 | /* Hash value of constant equivalent for SET_SRC. */ |
4158 | unsigned src_const_hash; | |
34e82342 RB |
4159 | /* A constant equivalent for SET_SRC, if any. */ |
4160 | rtx src_const; | |
7afe21cc RK |
4161 | /* Table entry for constant equivalent for SET_SRC, if any. */ |
4162 | struct table_elt *src_const_elt; | |
05c433f3 PB |
4163 | /* Table entry for the destination address. */ |
4164 | struct table_elt *dest_addr_elt; | |
7afe21cc | 4165 | }; |
7b02f4e0 SB |
4166 | \f |
4167 | /* Special handling for (set REG0 REG1) where REG0 is the | |
4168 | "cheapest", cheaper than REG1. After cse, REG1 will probably not | |
4169 | be used in the sequel, so (if easily done) change this insn to | |
4170 | (set REG1 REG0) and replace REG1 with REG0 in the previous insn | |
4171 | that computed their value. Then REG1 will become a dead store | |
4172 | and won't cloud the situation for later optimizations. | |
4173 | ||
4174 | Do not make this change if REG1 is a hard register, because it will | |
4175 | then be used in the sequel and we may be changing a two-operand insn | |
4176 | into a three-operand insn. | |
4177 | ||
4178 | This is the last transformation that cse_insn will try to do. */ | |
7afe21cc RK |
4179 | |
4180 | static void | |
20468884 | 4181 | try_back_substitute_reg (rtx set, rtx_insn *insn) |
7afe21cc | 4182 | { |
7b02f4e0 SB |
4183 | rtx dest = SET_DEST (set); |
4184 | rtx src = SET_SRC (set); | |
7afe21cc | 4185 | |
7b02f4e0 SB |
4186 | if (REG_P (dest) |
4187 | && REG_P (src) && ! HARD_REGISTER_P (src) | |
4188 | && REGNO_QTY_VALID_P (REGNO (src))) | |
4189 | { | |
4190 | int src_q = REG_QTY (REGNO (src)); | |
4191 | struct qty_table_elem *src_ent = &qty_table[src_q]; | |
7afe21cc | 4192 | |
7b02f4e0 SB |
4193 | if (src_ent->first_reg == REGNO (dest)) |
4194 | { | |
4195 | /* Scan for the previous nonnote insn, but stop at a basic | |
4196 | block boundary. */ | |
20468884 DM |
4197 | rtx_insn *prev = insn; |
4198 | rtx_insn *bb_head = BB_HEAD (BLOCK_FOR_INSN (insn)); | |
7b02f4e0 SB |
4199 | do |
4200 | { | |
4201 | prev = PREV_INSN (prev); | |
4202 | } | |
4203 | while (prev != bb_head && (NOTE_P (prev) || DEBUG_INSN_P (prev))); | |
7afe21cc | 4204 | |
7b02f4e0 SB |
4205 | /* Do not swap the registers around if the previous instruction |
4206 | attaches a REG_EQUIV note to REG1. | |
7afe21cc | 4207 | |
7b02f4e0 SB |
4208 | ??? It's not entirely clear whether we can transfer a REG_EQUIV |
4209 | from the pseudo that originally shadowed an incoming argument | |
4210 | to another register. Some uses of REG_EQUIV might rely on it | |
4211 | being attached to REG1 rather than REG2. | |
7afe21cc | 4212 | |
7b02f4e0 SB |
4213 | This section previously turned the REG_EQUIV into a REG_EQUAL |
4214 | note. We cannot do that because REG_EQUIV may provide an | |
4215 | uninitialized stack slot when REG_PARM_STACK_SPACE is used. */ | |
4216 | if (NONJUMP_INSN_P (prev) | |
4217 | && GET_CODE (PATTERN (prev)) == SET | |
4218 | && SET_DEST (PATTERN (prev)) == src | |
4219 | && ! find_reg_note (prev, REG_EQUIV, NULL_RTX)) | |
4220 | { | |
4221 | rtx note; | |
4222 | ||
4223 | validate_change (prev, &SET_DEST (PATTERN (prev)), dest, 1); | |
4224 | validate_change (insn, &SET_DEST (set), src, 1); | |
4225 | validate_change (insn, &SET_SRC (set), dest, 1); | |
4226 | apply_change_group (); | |
4227 | ||
4228 | /* If INSN has a REG_EQUAL note, and this note mentions | |
4229 | REG0, then we must delete it, because the value in | |
4230 | REG0 has changed. If the note's value is REG1, we must | |
4231 | also delete it because that is now this insn's dest. */ | |
4232 | note = find_reg_note (insn, REG_EQUAL, NULL_RTX); | |
4233 | if (note != 0 | |
4234 | && (reg_mentioned_p (dest, XEXP (note, 0)) | |
4235 | || rtx_equal_p (src, XEXP (note, 0)))) | |
4236 | remove_note (insn, note); | |
4237 | } | |
f474c6f8 | 4238 | } |
f1e7c95f | 4239 | } |
7b02f4e0 SB |
4240 | } |
4241 | \f | |
4242 | /* Record all the SETs in this instruction into SETS_PTR, | |
4243 | and return the number of recorded sets. */ | |
4244 | static int | |
20468884 | 4245 | find_sets_in_insn (rtx_insn *insn, struct set **psets) |
7b02f4e0 SB |
4246 | { |
4247 | struct set *sets = *psets; | |
4248 | int n_sets = 0; | |
4249 | rtx x = PATTERN (insn); | |
f1e7c95f | 4250 | |
7afe21cc RK |
4251 | if (GET_CODE (x) == SET) |
4252 | { | |
7afe21cc RK |
4253 | /* Ignore SETs that are unconditional jumps. |
4254 | They never need cse processing, so this does not hurt. | |
4255 | The reason is not efficiency but rather | |
4256 | so that we can test at the end for instructions | |
4257 | that have been simplified to unconditional jumps | |
4258 | and not be misled by unchanged instructions | |
4259 | that were unconditional jumps to begin with. */ | |
4260 | if (SET_DEST (x) == pc_rtx | |
4261 | && GET_CODE (SET_SRC (x)) == LABEL_REF) | |
4262 | ; | |
7afe21cc RK |
4263 | /* Don't count call-insns, (set (reg 0) (call ...)), as a set. |
4264 | The hard function value register is used only once, to copy to | |
7b02f4e0 | 4265 | someplace else, so it isn't worth cse'ing. */ |
7afe21cc | 4266 | else if (GET_CODE (SET_SRC (x)) == CALL) |
7b02f4e0 | 4267 | ; |
7afe21cc | 4268 | else |
7b02f4e0 | 4269 | sets[n_sets++].rtl = x; |
7afe21cc RK |
4270 | } |
4271 | else if (GET_CODE (x) == PARALLEL) | |
4272 | { | |
7b02f4e0 | 4273 | int i, lim = XVECLEN (x, 0); |
278a83b2 | 4274 | |
6c4d60f8 | 4275 | /* Go over the expressions of the PARALLEL in forward order, to |
7b02f4e0 | 4276 | put them in the same order in the SETS array. */ |
7afe21cc RK |
4277 | for (i = 0; i < lim; i++) |
4278 | { | |
b3694847 | 4279 | rtx y = XVECEXP (x, 0, i); |
7afe21cc RK |
4280 | if (GET_CODE (y) == SET) |
4281 | { | |
7722328e RK |
4282 | /* As above, we ignore unconditional jumps and call-insns and |
4283 | ignore the result of apply_change_group. */ | |
7b02f4e0 SB |
4284 | if (SET_DEST (y) == pc_rtx |
4285 | && GET_CODE (SET_SRC (y)) == LABEL_REF) | |
4286 | ; | |
4287 | else if (GET_CODE (SET_SRC (y)) == CALL) | |
7afe21cc RK |
4288 | ; |
4289 | else | |
4290 | sets[n_sets++].rtl = y; | |
4291 | } | |
7afe21cc RK |
4292 | } |
4293 | } | |
7b02f4e0 SB |
4294 | |
4295 | return n_sets; | |
4296 | } | |
4297 | \f | |
6380a82e EB |
4298 | /* Subroutine of canonicalize_insn. X is an ASM_OPERANDS in INSN. */ |
4299 | ||
4300 | static void | |
4301 | canon_asm_operands (rtx x, rtx_insn *insn) | |
4302 | { | |
4303 | for (int i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
4304 | { | |
4305 | rtx input = ASM_OPERANDS_INPUT (x, i); | |
4306 | if (!(REG_P (input) && HARD_REGISTER_P (input))) | |
4307 | { | |
4308 | input = canon_reg (input, insn); | |
4309 | validate_change (insn, &ASM_OPERANDS_INPUT (x, i), input, 1); | |
4310 | } | |
4311 | } | |
4312 | } | |
4313 | ||
7b02f4e0 | 4314 | /* Where possible, substitute every register reference in the N_SETS |
026c3cfd | 4315 | number of SETS in INSN with the canonical register. |
7b02f4e0 SB |
4316 | |
4317 | Register canonicalization propagatest the earliest register (i.e. | |
4318 | one that is set before INSN) with the same value. This is a very | |
4319 | useful, simple form of CSE, to clean up warts from expanding GIMPLE | |
4320 | to RTL. For instance, a CONST for an address is usually expanded | |
4321 | multiple times to loads into different registers, thus creating many | |
4322 | subexpressions of the form: | |
4323 | ||
4324 | (set (reg1) (some_const)) | |
4325 | (set (mem (... reg1 ...) (thing))) | |
4326 | (set (reg2) (some_const)) | |
4327 | (set (mem (... reg2 ...) (thing))) | |
4328 | ||
4329 | After canonicalizing, the code takes the following form: | |
4330 | ||
4331 | (set (reg1) (some_const)) | |
4332 | (set (mem (... reg1 ...) (thing))) | |
4333 | (set (reg2) (some_const)) | |
4334 | (set (mem (... reg1 ...) (thing))) | |
4335 | ||
4336 | The set to reg2 is now trivially dead, and the memory reference (or | |
4337 | address, or whatever) may be a candidate for further CSEing. | |
4338 | ||
4339 | In this function, the result of apply_change_group can be ignored; | |
4340 | see canon_reg. */ | |
4341 | ||
4342 | static void | |
20468884 | 4343 | canonicalize_insn (rtx_insn *insn, struct set **psets, int n_sets) |
7b02f4e0 SB |
4344 | { |
4345 | struct set *sets = *psets; | |
4346 | rtx tem; | |
4347 | rtx x = PATTERN (insn); | |
4348 | int i; | |
4349 | ||
4350 | if (CALL_P (insn)) | |
4351 | { | |
4352 | for (tem = CALL_INSN_FUNCTION_USAGE (insn); tem; tem = XEXP (tem, 1)) | |
e384e6b5 BS |
4353 | if (GET_CODE (XEXP (tem, 0)) != SET) |
4354 | XEXP (tem, 0) = canon_reg (XEXP (tem, 0), insn); | |
7b02f4e0 SB |
4355 | } |
4356 | ||
4357 | if (GET_CODE (x) == SET && GET_CODE (SET_SRC (x)) == CALL) | |
4358 | { | |
4359 | canon_reg (SET_SRC (x), insn); | |
4360 | apply_change_group (); | |
4361 | fold_rtx (SET_SRC (x), insn); | |
4362 | } | |
7afe21cc RK |
4363 | else if (GET_CODE (x) == CLOBBER) |
4364 | { | |
7b02f4e0 SB |
4365 | /* If we clobber memory, canon the address. |
4366 | This does nothing when a register is clobbered | |
4367 | because we have already invalidated the reg. */ | |
3c0cb5de | 4368 | if (MEM_P (XEXP (x, 0))) |
6fb5fa3c | 4369 | canon_reg (XEXP (x, 0), insn); |
7afe21cc | 4370 | } |
7afe21cc | 4371 | else if (GET_CODE (x) == USE |
f8cfc6aa | 4372 | && ! (REG_P (XEXP (x, 0)) |
7afe21cc | 4373 | && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)) |
7b02f4e0 | 4374 | /* Canonicalize a USE of a pseudo register or memory location. */ |
b1ba284c EB |
4375 | canon_reg (x, insn); |
4376 | else if (GET_CODE (x) == ASM_OPERANDS) | |
6380a82e | 4377 | canon_asm_operands (x, insn); |
7afe21cc RK |
4378 | else if (GET_CODE (x) == CALL) |
4379 | { | |
4380 | canon_reg (x, insn); | |
77fa0940 | 4381 | apply_change_group (); |
7afe21cc RK |
4382 | fold_rtx (x, insn); |
4383 | } | |
b5b8b0ac AO |
4384 | else if (DEBUG_INSN_P (insn)) |
4385 | canon_reg (PATTERN (insn), insn); | |
7b02f4e0 SB |
4386 | else if (GET_CODE (x) == PARALLEL) |
4387 | { | |
4388 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
4389 | { | |
4390 | rtx y = XVECEXP (x, 0, i); | |
4391 | if (GET_CODE (y) == SET && GET_CODE (SET_SRC (y)) == CALL) | |
4392 | { | |
4393 | canon_reg (SET_SRC (y), insn); | |
4394 | apply_change_group (); | |
4395 | fold_rtx (SET_SRC (y), insn); | |
4396 | } | |
4397 | else if (GET_CODE (y) == CLOBBER) | |
4398 | { | |
4399 | if (MEM_P (XEXP (y, 0))) | |
4400 | canon_reg (XEXP (y, 0), insn); | |
4401 | } | |
4402 | else if (GET_CODE (y) == USE | |
4403 | && ! (REG_P (XEXP (y, 0)) | |
4404 | && REGNO (XEXP (y, 0)) < FIRST_PSEUDO_REGISTER)) | |
4405 | canon_reg (y, insn); | |
6380a82e EB |
4406 | else if (GET_CODE (y) == ASM_OPERANDS) |
4407 | canon_asm_operands (y, insn); | |
7b02f4e0 SB |
4408 | else if (GET_CODE (y) == CALL) |
4409 | { | |
4410 | canon_reg (y, insn); | |
4411 | apply_change_group (); | |
4412 | fold_rtx (y, insn); | |
4413 | } | |
4414 | } | |
4415 | } | |
7afe21cc | 4416 | |
92f9aa51 | 4417 | if (n_sets == 1 && REG_NOTES (insn) != 0 |
7b02f4e0 | 4418 | && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0) |
7b668f9e | 4419 | { |
7b02f4e0 SB |
4420 | /* We potentially will process this insn many times. Therefore, |
4421 | drop the REG_EQUAL note if it is equal to the SET_SRC of the | |
4422 | unique set in INSN. | |
4423 | ||
4424 | Do not do so if the REG_EQUAL note is for a STRICT_LOW_PART, | |
4425 | because cse_insn handles those specially. */ | |
4426 | if (GET_CODE (SET_DEST (sets[0].rtl)) != STRICT_LOW_PART | |
4427 | && rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl))) | |
4428 | remove_note (insn, tem); | |
4429 | else | |
4430 | { | |
4431 | canon_reg (XEXP (tem, 0), insn); | |
4432 | apply_change_group (); | |
4433 | XEXP (tem, 0) = fold_rtx (XEXP (tem, 0), insn); | |
4434 | df_notes_rescan (insn); | |
4435 | } | |
7b668f9e | 4436 | } |
7afe21cc RK |
4437 | |
4438 | /* Canonicalize sources and addresses of destinations. | |
4439 | We do this in a separate pass to avoid problems when a MATCH_DUP is | |
4440 | present in the insn pattern. In that case, we want to ensure that | |
4441 | we don't break the duplicate nature of the pattern. So we will replace | |
4442 | both operands at the same time. Otherwise, we would fail to find an | |
4443 | equivalent substitution in the loop calling validate_change below. | |
7afe21cc RK |
4444 | |
4445 | We used to suppress canonicalization of DEST if it appears in SRC, | |
77fa0940 | 4446 | but we don't do this any more. */ |
7afe21cc RK |
4447 | |
4448 | for (i = 0; i < n_sets; i++) | |
4449 | { | |
4450 | rtx dest = SET_DEST (sets[i].rtl); | |
4451 | rtx src = SET_SRC (sets[i].rtl); | |
32e9fa48 | 4452 | rtx new_rtx = canon_reg (src, insn); |
7afe21cc | 4453 | |
32e9fa48 | 4454 | validate_change (insn, &SET_SRC (sets[i].rtl), new_rtx, 1); |
7afe21cc | 4455 | |
46d096a3 | 4456 | if (GET_CODE (dest) == ZERO_EXTRACT) |
7afe21cc RK |
4457 | { |
4458 | validate_change (insn, &XEXP (dest, 1), | |
77fa0940 | 4459 | canon_reg (XEXP (dest, 1), insn), 1); |
7afe21cc | 4460 | validate_change (insn, &XEXP (dest, 2), |
77fa0940 | 4461 | canon_reg (XEXP (dest, 2), insn), 1); |
7afe21cc RK |
4462 | } |
4463 | ||
46d096a3 | 4464 | while (GET_CODE (dest) == SUBREG |
7afe21cc | 4465 | || GET_CODE (dest) == ZERO_EXTRACT |
46d096a3 | 4466 | || GET_CODE (dest) == STRICT_LOW_PART) |
7afe21cc RK |
4467 | dest = XEXP (dest, 0); |
4468 | ||
3c0cb5de | 4469 | if (MEM_P (dest)) |
7afe21cc RK |
4470 | canon_reg (dest, insn); |
4471 | } | |
4472 | ||
77fa0940 RK |
4473 | /* Now that we have done all the replacements, we can apply the change |
4474 | group and see if they all work. Note that this will cause some | |
4475 | canonicalizations that would have worked individually not to be applied | |
4476 | because some other canonicalization didn't work, but this should not | |
278a83b2 | 4477 | occur often. |
7722328e RK |
4478 | |
4479 | The result of apply_change_group can be ignored; see canon_reg. */ | |
77fa0940 RK |
4480 | |
4481 | apply_change_group (); | |
7b02f4e0 SB |
4482 | } |
4483 | \f | |
4484 | /* Main function of CSE. | |
4485 | First simplify sources and addresses of all assignments | |
4486 | in the instruction, using previously-computed equivalents values. | |
4487 | Then install the new sources and destinations in the table | |
4488 | of available values. */ | |
4489 | ||
4490 | static void | |
20468884 | 4491 | cse_insn (rtx_insn *insn) |
7b02f4e0 SB |
4492 | { |
4493 | rtx x = PATTERN (insn); | |
4494 | int i; | |
4495 | rtx tem; | |
4496 | int n_sets = 0; | |
4497 | ||
4498 | rtx src_eqv = 0; | |
4499 | struct table_elt *src_eqv_elt = 0; | |
4500 | int src_eqv_volatile = 0; | |
4501 | int src_eqv_in_memory = 0; | |
4502 | unsigned src_eqv_hash = 0; | |
4503 | ||
4504 | struct set *sets = (struct set *) 0; | |
4505 | ||
4506 | if (GET_CODE (x) == SET) | |
4507 | sets = XALLOCA (struct set); | |
4508 | else if (GET_CODE (x) == PARALLEL) | |
4509 | sets = XALLOCAVEC (struct set, XVECLEN (x, 0)); | |
4510 | ||
4511 | this_insn = insn; | |
7b02f4e0 SB |
4512 | /* Records what this insn does to set CC0. */ |
4513 | this_insn_cc0 = 0; | |
4514 | this_insn_cc0_mode = VOIDmode; | |
7b02f4e0 SB |
4515 | |
4516 | /* Find all regs explicitly clobbered in this insn, | |
4517 | to ensure they are not replaced with any other regs | |
4518 | elsewhere in this insn. */ | |
4519 | invalidate_from_sets_and_clobbers (insn); | |
4520 | ||
4521 | /* Record all the SETs in this instruction. */ | |
4522 | n_sets = find_sets_in_insn (insn, &sets); | |
4523 | ||
4524 | /* Substitute the canonical register where possible. */ | |
4525 | canonicalize_insn (insn, &sets, n_sets); | |
4526 | ||
4527 | /* If this insn has a REG_EQUAL note, store the equivalent value in SRC_EQV, | |
7f7379f6 KV |
4528 | if different, or if the DEST is a STRICT_LOW_PART/ZERO_EXTRACT. The |
4529 | latter condition is necessary because SRC_EQV is handled specially for | |
4530 | this case, and if it isn't set, then there will be no equivalence | |
4531 | for the destination. */ | |
7b02f4e0 | 4532 | if (n_sets == 1 && REG_NOTES (insn) != 0 |
1e928e07 | 4533 | && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0) |
7f7379f6 | 4534 | { |
7f7379f6 | 4535 | |
1e928e07 KV |
4536 | if (GET_CODE (SET_DEST (sets[0].rtl)) != ZERO_EXTRACT |
4537 | && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl)) | |
4538 | || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART)) | |
4539 | src_eqv = copy_rtx (XEXP (tem, 0)); | |
7f7379f6 KV |
4540 | /* If DEST is of the form ZERO_EXTACT, as in: |
4541 | (set (zero_extract:SI (reg:SI 119) | |
4542 | (const_int 16 [0x10]) | |
4543 | (const_int 16 [0x10])) | |
4544 | (const_int 51154 [0xc7d2])) | |
4545 | REG_EQUAL note will specify the value of register (reg:SI 119) at this | |
4546 | point. Note that this is different from SRC_EQV. We can however | |
4547 | calculate SRC_EQV with the position and width of ZERO_EXTRACT. */ | |
4548 | else if (GET_CODE (SET_DEST (sets[0].rtl)) == ZERO_EXTRACT | |
fa24123b | 4549 | && CONST_INT_P (XEXP (tem, 0)) |
7f7379f6 KV |
4550 | && CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 1)) |
4551 | && CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 2))) | |
4552 | { | |
4553 | rtx dest_reg = XEXP (SET_DEST (sets[0].rtl), 0); | |
4554 | rtx width = XEXP (SET_DEST (sets[0].rtl), 1); | |
4555 | rtx pos = XEXP (SET_DEST (sets[0].rtl), 2); | |
fa24123b | 4556 | HOST_WIDE_INT val = INTVAL (XEXP (tem, 0)); |
7f7379f6 KV |
4557 | HOST_WIDE_INT mask; |
4558 | unsigned int shift; | |
4559 | if (BITS_BIG_ENDIAN) | |
4560 | shift = GET_MODE_PRECISION (GET_MODE (dest_reg)) | |
4561 | - INTVAL (pos) - INTVAL (width); | |
4562 | else | |
4563 | shift = INTVAL (pos); | |
4564 | if (INTVAL (width) == HOST_BITS_PER_WIDE_INT) | |
dd4786fe | 4565 | mask = HOST_WIDE_INT_M1; |
7f7379f6 | 4566 | else |
fecfbfa4 | 4567 | mask = (HOST_WIDE_INT_1 << INTVAL (width)) - 1; |
7f7379f6 KV |
4568 | val = (val >> shift) & mask; |
4569 | src_eqv = GEN_INT (val); | |
4570 | } | |
4571 | } | |
77fa0940 | 4572 | |
7afe21cc RK |
4573 | /* Set sets[i].src_elt to the class each source belongs to. |
4574 | Detect assignments from or to volatile things | |
4575 | and set set[i] to zero so they will be ignored | |
4576 | in the rest of this function. | |
4577 | ||
4578 | Nothing in this loop changes the hash table or the register chains. */ | |
4579 | ||
4580 | for (i = 0; i < n_sets; i++) | |
4581 | { | |
b4ab701f | 4582 | bool repeat = false; |
dd77684f | 4583 | bool mem_noop_insn = false; |
b3694847 SS |
4584 | rtx src, dest; |
4585 | rtx src_folded; | |
4586 | struct table_elt *elt = 0, *p; | |
ef4bddc2 | 4587 | machine_mode mode; |
7afe21cc RK |
4588 | rtx src_eqv_here; |
4589 | rtx src_const = 0; | |
4590 | rtx src_related = 0; | |
2c5bfdf7 | 4591 | bool src_related_is_const_anchor = false; |
7afe21cc | 4592 | struct table_elt *src_const_elt = 0; |
99a9c946 GS |
4593 | int src_cost = MAX_COST; |
4594 | int src_eqv_cost = MAX_COST; | |
4595 | int src_folded_cost = MAX_COST; | |
4596 | int src_related_cost = MAX_COST; | |
4597 | int src_elt_cost = MAX_COST; | |
4598 | int src_regcost = MAX_COST; | |
4599 | int src_eqv_regcost = MAX_COST; | |
4600 | int src_folded_regcost = MAX_COST; | |
4601 | int src_related_regcost = MAX_COST; | |
4602 | int src_elt_regcost = MAX_COST; | |
da7d8304 | 4603 | /* Set nonzero if we need to call force_const_mem on with the |
7afe21cc RK |
4604 | contents of src_folded before using it. */ |
4605 | int src_folded_force_flag = 0; | |
4606 | ||
4607 | dest = SET_DEST (sets[i].rtl); | |
4608 | src = SET_SRC (sets[i].rtl); | |
4609 | ||
4610 | /* If SRC is a constant that has no machine mode, | |
4611 | hash it with the destination's machine mode. | |
4612 | This way we can keep different modes separate. */ | |
4613 | ||
4614 | mode = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src); | |
4615 | sets[i].mode = mode; | |
4616 | ||
4617 | if (src_eqv) | |
4618 | { | |
ef4bddc2 | 4619 | machine_mode eqvmode = mode; |
7afe21cc RK |
4620 | if (GET_CODE (dest) == STRICT_LOW_PART) |
4621 | eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0))); | |
4622 | do_not_record = 0; | |
4623 | hash_arg_in_memory = 0; | |
2197a88a | 4624 | src_eqv_hash = HASH (src_eqv, eqvmode); |
7afe21cc RK |
4625 | |
4626 | /* Find the equivalence class for the equivalent expression. */ | |
4627 | ||
4628 | if (!do_not_record) | |
2197a88a | 4629 | src_eqv_elt = lookup (src_eqv, src_eqv_hash, eqvmode); |
7afe21cc RK |
4630 | |
4631 | src_eqv_volatile = do_not_record; | |
4632 | src_eqv_in_memory = hash_arg_in_memory; | |
7afe21cc RK |
4633 | } |
4634 | ||
4635 | /* If this is a STRICT_LOW_PART assignment, src_eqv corresponds to the | |
4636 | value of the INNER register, not the destination. So it is not | |
3826a3da | 4637 | a valid substitution for the source. But save it for later. */ |
7afe21cc RK |
4638 | if (GET_CODE (dest) == STRICT_LOW_PART) |
4639 | src_eqv_here = 0; | |
4640 | else | |
4641 | src_eqv_here = src_eqv; | |
4642 | ||
4643 | /* Simplify and foldable subexpressions in SRC. Then get the fully- | |
4644 | simplified result, which may not necessarily be valid. */ | |
625d55af | 4645 | src_folded = fold_rtx (src, NULL); |
7afe21cc | 4646 | |
e6a125a0 RK |
4647 | #if 0 |
4648 | /* ??? This caused bad code to be generated for the m68k port with -O2. | |
4649 | Suppose src is (CONST_INT -1), and that after truncation src_folded | |
4650 | is (CONST_INT 3). Suppose src_folded is then used for src_const. | |
4651 | At the end we will add src and src_const to the same equivalence | |
4652 | class. We now have 3 and -1 on the same equivalence class. This | |
4653 | causes later instructions to be mis-optimized. */ | |
7afe21cc RK |
4654 | /* If storing a constant in a bitfield, pre-truncate the constant |
4655 | so we will be able to record it later. */ | |
46d096a3 | 4656 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT) |
7afe21cc RK |
4657 | { |
4658 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
4659 | ||
481683e1 SZ |
4660 | if (CONST_INT_P (src) |
4661 | && CONST_INT_P (width) | |
906c4e36 RK |
4662 | && INTVAL (width) < HOST_BITS_PER_WIDE_INT |
4663 | && (INTVAL (src) & ((HOST_WIDE_INT) (-1) << INTVAL (width)))) | |
4664 | src_folded | |
fecfbfa4 | 4665 | = GEN_INT (INTVAL (src) & ((HOST_WIDE_INT_1 |
906c4e36 | 4666 | << INTVAL (width)) - 1)); |
7afe21cc | 4667 | } |
e6a125a0 | 4668 | #endif |
7afe21cc RK |
4669 | |
4670 | /* Compute SRC's hash code, and also notice if it | |
4671 | should not be recorded at all. In that case, | |
4672 | prevent any further processing of this assignment. */ | |
4673 | do_not_record = 0; | |
4674 | hash_arg_in_memory = 0; | |
7afe21cc RK |
4675 | |
4676 | sets[i].src = src; | |
2197a88a | 4677 | sets[i].src_hash = HASH (src, mode); |
7afe21cc RK |
4678 | sets[i].src_volatile = do_not_record; |
4679 | sets[i].src_in_memory = hash_arg_in_memory; | |
7afe21cc | 4680 | |
50196afa | 4681 | /* If SRC is a MEM, there is a REG_EQUIV note for SRC, and DEST is |
43e72072 JJ |
4682 | a pseudo, do not record SRC. Using SRC as a replacement for |
4683 | anything else will be incorrect in that situation. Note that | |
4684 | this usually occurs only for stack slots, in which case all the | |
4685 | RTL would be referring to SRC, so we don't lose any optimization | |
4686 | opportunities by not having SRC in the hash table. */ | |
50196afa | 4687 | |
3c0cb5de | 4688 | if (MEM_P (src) |
43e72072 | 4689 | && find_reg_note (insn, REG_EQUIV, NULL_RTX) != 0 |
f8cfc6aa | 4690 | && REG_P (dest) |
43e72072 | 4691 | && REGNO (dest) >= FIRST_PSEUDO_REGISTER) |
50196afa RK |
4692 | sets[i].src_volatile = 1; |
4693 | ||
d8d6ea53 JJ |
4694 | else if (GET_CODE (src) == ASM_OPERANDS |
4695 | && GET_CODE (x) == PARALLEL) | |
6c4d60f8 JJ |
4696 | { |
4697 | /* Do not record result of a non-volatile inline asm with | |
4698 | more than one result. */ | |
4699 | if (n_sets > 1) | |
4700 | sets[i].src_volatile = 1; | |
4701 | ||
4702 | int j, lim = XVECLEN (x, 0); | |
4703 | for (j = 0; j < lim; j++) | |
4704 | { | |
4705 | rtx y = XVECEXP (x, 0, j); | |
4706 | /* And do not record result of a non-volatile inline asm | |
4707 | with "memory" clobber. */ | |
4708 | if (GET_CODE (y) == CLOBBER && MEM_P (XEXP (y, 0))) | |
4709 | { | |
4710 | sets[i].src_volatile = 1; | |
4711 | break; | |
4712 | } | |
4713 | } | |
4714 | } | |
d8d6ea53 | 4715 | |
0dadecf6 RK |
4716 | #if 0 |
4717 | /* It is no longer clear why we used to do this, but it doesn't | |
4718 | appear to still be needed. So let's try without it since this | |
4719 | code hurts cse'ing widened ops. */ | |
9a5a17f3 | 4720 | /* If source is a paradoxical subreg (such as QI treated as an SI), |
7afe21cc RK |
4721 | treat it as volatile. It may do the work of an SI in one context |
4722 | where the extra bits are not being used, but cannot replace an SI | |
4723 | in general. */ | |
6a4bdc79 | 4724 | if (paradoxical_subreg_p (src)) |
7afe21cc | 4725 | sets[i].src_volatile = 1; |
0dadecf6 | 4726 | #endif |
7afe21cc RK |
4727 | |
4728 | /* Locate all possible equivalent forms for SRC. Try to replace | |
4729 | SRC in the insn with each cheaper equivalent. | |
4730 | ||
4731 | We have the following types of equivalents: SRC itself, a folded | |
4732 | version, a value given in a REG_EQUAL note, or a value related | |
4733 | to a constant. | |
4734 | ||
4735 | Each of these equivalents may be part of an additional class | |
4736 | of equivalents (if more than one is in the table, they must be in | |
4737 | the same class; we check for this). | |
4738 | ||
4739 | If the source is volatile, we don't do any table lookups. | |
4740 | ||
4741 | We note any constant equivalent for possible later use in a | |
4742 | REG_NOTE. */ | |
4743 | ||
4744 | if (!sets[i].src_volatile) | |
2197a88a | 4745 | elt = lookup (src, sets[i].src_hash, mode); |
7afe21cc RK |
4746 | |
4747 | sets[i].src_elt = elt; | |
4748 | ||
4749 | if (elt && src_eqv_here && src_eqv_elt) | |
278a83b2 KH |
4750 | { |
4751 | if (elt->first_same_value != src_eqv_elt->first_same_value) | |
7afe21cc RK |
4752 | { |
4753 | /* The REG_EQUAL is indicating that two formerly distinct | |
4754 | classes are now equivalent. So merge them. */ | |
4755 | merge_equiv_classes (elt, src_eqv_elt); | |
2197a88a RK |
4756 | src_eqv_hash = HASH (src_eqv, elt->mode); |
4757 | src_eqv_elt = lookup (src_eqv, src_eqv_hash, elt->mode); | |
7afe21cc RK |
4758 | } |
4759 | ||
278a83b2 KH |
4760 | src_eqv_here = 0; |
4761 | } | |
7afe21cc RK |
4762 | |
4763 | else if (src_eqv_elt) | |
278a83b2 | 4764 | elt = src_eqv_elt; |
7afe21cc RK |
4765 | |
4766 | /* Try to find a constant somewhere and record it in `src_const'. | |
4767 | Record its table element, if any, in `src_const_elt'. Look in | |
4768 | any known equivalences first. (If the constant is not in the | |
2197a88a | 4769 | table, also set `sets[i].src_const_hash'). */ |
7afe21cc | 4770 | if (elt) |
278a83b2 | 4771 | for (p = elt->first_same_value; p; p = p->next_same_value) |
7afe21cc RK |
4772 | if (p->is_const) |
4773 | { | |
4774 | src_const = p->exp; | |
4775 | src_const_elt = elt; | |
4776 | break; | |
4777 | } | |
4778 | ||
4779 | if (src_const == 0 | |
4780 | && (CONSTANT_P (src_folded) | |
278a83b2 | 4781 | /* Consider (minus (label_ref L1) (label_ref L2)) as |
7afe21cc RK |
4782 | "constant" here so we will record it. This allows us |
4783 | to fold switch statements when an ADDR_DIFF_VEC is used. */ | |
4784 | || (GET_CODE (src_folded) == MINUS | |
4785 | && GET_CODE (XEXP (src_folded, 0)) == LABEL_REF | |
4786 | && GET_CODE (XEXP (src_folded, 1)) == LABEL_REF))) | |
4787 | src_const = src_folded, src_const_elt = elt; | |
4788 | else if (src_const == 0 && src_eqv_here && CONSTANT_P (src_eqv_here)) | |
4789 | src_const = src_eqv_here, src_const_elt = src_eqv_elt; | |
4790 | ||
4791 | /* If we don't know if the constant is in the table, get its | |
4792 | hash code and look it up. */ | |
4793 | if (src_const && src_const_elt == 0) | |
4794 | { | |
2197a88a RK |
4795 | sets[i].src_const_hash = HASH (src_const, mode); |
4796 | src_const_elt = lookup (src_const, sets[i].src_const_hash, mode); | |
7afe21cc RK |
4797 | } |
4798 | ||
4799 | sets[i].src_const = src_const; | |
4800 | sets[i].src_const_elt = src_const_elt; | |
4801 | ||
4802 | /* If the constant and our source are both in the table, mark them as | |
4803 | equivalent. Otherwise, if a constant is in the table but the source | |
4804 | isn't, set ELT to it. */ | |
4805 | if (src_const_elt && elt | |
4806 | && src_const_elt->first_same_value != elt->first_same_value) | |
4807 | merge_equiv_classes (elt, src_const_elt); | |
4808 | else if (src_const_elt && elt == 0) | |
4809 | elt = src_const_elt; | |
4810 | ||
4811 | /* See if there is a register linearly related to a constant | |
4812 | equivalent of SRC. */ | |
4813 | if (src_const | |
4814 | && (GET_CODE (src_const) == CONST | |
4815 | || (src_const_elt && src_const_elt->related_value != 0))) | |
278a83b2 KH |
4816 | { |
4817 | src_related = use_related_value (src_const, src_const_elt); | |
4818 | if (src_related) | |
4819 | { | |
7afe21cc | 4820 | struct table_elt *src_related_elt |
278a83b2 | 4821 | = lookup (src_related, HASH (src_related, mode), mode); |
7afe21cc | 4822 | if (src_related_elt && elt) |
278a83b2 | 4823 | { |
7afe21cc RK |
4824 | if (elt->first_same_value |
4825 | != src_related_elt->first_same_value) | |
278a83b2 | 4826 | /* This can occur when we previously saw a CONST |
7afe21cc RK |
4827 | involving a SYMBOL_REF and then see the SYMBOL_REF |
4828 | twice. Merge the involved classes. */ | |
4829 | merge_equiv_classes (elt, src_related_elt); | |
4830 | ||
278a83b2 | 4831 | src_related = 0; |
7afe21cc | 4832 | src_related_elt = 0; |
278a83b2 KH |
4833 | } |
4834 | else if (src_related_elt && elt == 0) | |
4835 | elt = src_related_elt; | |
7afe21cc | 4836 | } |
278a83b2 | 4837 | } |
7afe21cc | 4838 | |
e4600702 RK |
4839 | /* See if we have a CONST_INT that is already in a register in a |
4840 | wider mode. */ | |
4841 | ||
481683e1 | 4842 | if (src_const && src_related == 0 && CONST_INT_P (src_const) |
e4600702 | 4843 | && GET_MODE_CLASS (mode) == MODE_INT |
5511bc5a | 4844 | && GET_MODE_PRECISION (mode) < BITS_PER_WORD) |
e4600702 | 4845 | { |
ef4bddc2 | 4846 | machine_mode wider_mode; |
e4600702 RK |
4847 | |
4848 | for (wider_mode = GET_MODE_WIDER_MODE (mode); | |
1f3ad3f0 | 4849 | wider_mode != VOIDmode |
5511bc5a | 4850 | && GET_MODE_PRECISION (wider_mode) <= BITS_PER_WORD |
e4600702 RK |
4851 | && src_related == 0; |
4852 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
4853 | { | |
4854 | struct table_elt *const_elt | |
4855 | = lookup (src_const, HASH (src_const, wider_mode), wider_mode); | |
4856 | ||
4857 | if (const_elt == 0) | |
4858 | continue; | |
4859 | ||
4860 | for (const_elt = const_elt->first_same_value; | |
4861 | const_elt; const_elt = const_elt->next_same_value) | |
f8cfc6aa | 4862 | if (REG_P (const_elt->exp)) |
e4600702 | 4863 | { |
73ca11ed | 4864 | src_related = gen_lowpart (mode, const_elt->exp); |
e4600702 RK |
4865 | break; |
4866 | } | |
4867 | } | |
4868 | } | |
4869 | ||
d45cf215 RS |
4870 | /* Another possibility is that we have an AND with a constant in |
4871 | a mode narrower than a word. If so, it might have been generated | |
4872 | as part of an "if" which would narrow the AND. If we already | |
4873 | have done the AND in a wider mode, we can use a SUBREG of that | |
4874 | value. */ | |
4875 | ||
4876 | if (flag_expensive_optimizations && ! src_related | |
481683e1 | 4877 | && GET_CODE (src) == AND && CONST_INT_P (XEXP (src, 1)) |
d45cf215 RS |
4878 | && GET_MODE_SIZE (mode) < UNITS_PER_WORD) |
4879 | { | |
ef4bddc2 | 4880 | machine_mode tmode; |
38a448ca | 4881 | rtx new_and = gen_rtx_AND (VOIDmode, NULL_RTX, XEXP (src, 1)); |
d45cf215 RS |
4882 | |
4883 | for (tmode = GET_MODE_WIDER_MODE (mode); | |
4884 | GET_MODE_SIZE (tmode) <= UNITS_PER_WORD; | |
4885 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
4886 | { | |
4de249d9 | 4887 | rtx inner = gen_lowpart (tmode, XEXP (src, 0)); |
d45cf215 RS |
4888 | struct table_elt *larger_elt; |
4889 | ||
4890 | if (inner) | |
4891 | { | |
4892 | PUT_MODE (new_and, tmode); | |
4893 | XEXP (new_and, 0) = inner; | |
4894 | larger_elt = lookup (new_and, HASH (new_and, tmode), tmode); | |
4895 | if (larger_elt == 0) | |
4896 | continue; | |
4897 | ||
4898 | for (larger_elt = larger_elt->first_same_value; | |
4899 | larger_elt; larger_elt = larger_elt->next_same_value) | |
f8cfc6aa | 4900 | if (REG_P (larger_elt->exp)) |
d45cf215 RS |
4901 | { |
4902 | src_related | |
4de249d9 | 4903 | = gen_lowpart (mode, larger_elt->exp); |
d45cf215 RS |
4904 | break; |
4905 | } | |
4906 | ||
4907 | if (src_related) | |
4908 | break; | |
4909 | } | |
4910 | } | |
4911 | } | |
7bac1be0 | 4912 | |
7bac1be0 RK |
4913 | /* See if a MEM has already been loaded with a widening operation; |
4914 | if it has, we can use a subreg of that. Many CISC machines | |
4915 | also have such operations, but this is only likely to be | |
71cc389b | 4916 | beneficial on these machines. */ |
278a83b2 | 4917 | |
3712c7a3 | 4918 | rtx_code extend_op; |
ddc356e8 | 4919 | if (flag_expensive_optimizations && src_related == 0 |
3c0cb5de | 4920 | && MEM_P (src) && ! do_not_record |
3712c7a3 | 4921 | && (extend_op = load_extend_op (mode)) != UNKNOWN) |
7bac1be0 | 4922 | { |
9d80ef7c RH |
4923 | struct rtx_def memory_extend_buf; |
4924 | rtx memory_extend_rtx = &memory_extend_buf; | |
ef4bddc2 | 4925 | machine_mode tmode; |
278a83b2 | 4926 | |
7bac1be0 RK |
4927 | /* Set what we are trying to extend and the operation it might |
4928 | have been extended with. */ | |
c3284718 | 4929 | memset (memory_extend_rtx, 0, sizeof (*memory_extend_rtx)); |
3712c7a3 | 4930 | PUT_CODE (memory_extend_rtx, extend_op); |
7bac1be0 | 4931 | XEXP (memory_extend_rtx, 0) = src; |
278a83b2 | 4932 | |
7bac1be0 RK |
4933 | for (tmode = GET_MODE_WIDER_MODE (mode); |
4934 | GET_MODE_SIZE (tmode) <= UNITS_PER_WORD; | |
4935 | tmode = GET_MODE_WIDER_MODE (tmode)) | |
4936 | { | |
4937 | struct table_elt *larger_elt; | |
278a83b2 | 4938 | |
7bac1be0 | 4939 | PUT_MODE (memory_extend_rtx, tmode); |
278a83b2 | 4940 | larger_elt = lookup (memory_extend_rtx, |
7bac1be0 RK |
4941 | HASH (memory_extend_rtx, tmode), tmode); |
4942 | if (larger_elt == 0) | |
4943 | continue; | |
278a83b2 | 4944 | |
7bac1be0 RK |
4945 | for (larger_elt = larger_elt->first_same_value; |
4946 | larger_elt; larger_elt = larger_elt->next_same_value) | |
f8cfc6aa | 4947 | if (REG_P (larger_elt->exp)) |
7bac1be0 | 4948 | { |
73ca11ed | 4949 | src_related = gen_lowpart (mode, larger_elt->exp); |
7bac1be0 RK |
4950 | break; |
4951 | } | |
278a83b2 | 4952 | |
7bac1be0 RK |
4953 | if (src_related) |
4954 | break; | |
4955 | } | |
4956 | } | |
278a83b2 | 4957 | |
2c5bfdf7 AN |
4958 | /* Try to express the constant using a register+offset expression |
4959 | derived from a constant anchor. */ | |
4960 | ||
4961 | if (targetm.const_anchor | |
4962 | && !src_related | |
4963 | && src_const | |
4964 | && GET_CODE (src_const) == CONST_INT) | |
4965 | { | |
4966 | src_related = try_const_anchors (src_const, mode); | |
4967 | src_related_is_const_anchor = src_related != NULL_RTX; | |
4968 | } | |
4969 | ||
4970 | ||
7afe21cc | 4971 | if (src == src_folded) |
278a83b2 | 4972 | src_folded = 0; |
7afe21cc | 4973 | |
da7d8304 | 4974 | /* At this point, ELT, if nonzero, points to a class of expressions |
7afe21cc | 4975 | equivalent to the source of this SET and SRC, SRC_EQV, SRC_FOLDED, |
da7d8304 | 4976 | and SRC_RELATED, if nonzero, each contain additional equivalent |
7afe21cc RK |
4977 | expressions. Prune these latter expressions by deleting expressions |
4978 | already in the equivalence class. | |
4979 | ||
4980 | Check for an equivalent identical to the destination. If found, | |
4981 | this is the preferred equivalent since it will likely lead to | |
4982 | elimination of the insn. Indicate this by placing it in | |
4983 | `src_related'. */ | |
4984 | ||
278a83b2 KH |
4985 | if (elt) |
4986 | elt = elt->first_same_value; | |
7afe21cc | 4987 | for (p = elt; p; p = p->next_same_value) |
278a83b2 | 4988 | { |
7afe21cc RK |
4989 | enum rtx_code code = GET_CODE (p->exp); |
4990 | ||
4991 | /* If the expression is not valid, ignore it. Then we do not | |
4992 | have to check for validity below. In most cases, we can use | |
4993 | `rtx_equal_p', since canonicalization has already been done. */ | |
0516f6fe | 4994 | if (code != REG && ! exp_equiv_p (p->exp, p->exp, 1, false)) |
7afe21cc RK |
4995 | continue; |
4996 | ||
5a03c8c4 RK |
4997 | /* Also skip paradoxical subregs, unless that's what we're |
4998 | looking for. */ | |
6a4bdc79 | 4999 | if (paradoxical_subreg_p (p->exp) |
5a03c8c4 RK |
5000 | && ! (src != 0 |
5001 | && GET_CODE (src) == SUBREG | |
5002 | && GET_MODE (src) == GET_MODE (p->exp) | |
5003 | && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))) | |
5004 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp)))))) | |
5005 | continue; | |
5006 | ||
278a83b2 | 5007 | if (src && GET_CODE (src) == code && rtx_equal_p (src, p->exp)) |
7afe21cc | 5008 | src = 0; |
278a83b2 | 5009 | else if (src_folded && GET_CODE (src_folded) == code |
7afe21cc RK |
5010 | && rtx_equal_p (src_folded, p->exp)) |
5011 | src_folded = 0; | |
278a83b2 | 5012 | else if (src_eqv_here && GET_CODE (src_eqv_here) == code |
7afe21cc RK |
5013 | && rtx_equal_p (src_eqv_here, p->exp)) |
5014 | src_eqv_here = 0; | |
278a83b2 | 5015 | else if (src_related && GET_CODE (src_related) == code |
7afe21cc RK |
5016 | && rtx_equal_p (src_related, p->exp)) |
5017 | src_related = 0; | |
5018 | ||
5019 | /* This is the same as the destination of the insns, we want | |
5020 | to prefer it. Copy it to src_related. The code below will | |
5021 | then give it a negative cost. */ | |
5022 | if (GET_CODE (dest) == code && rtx_equal_p (p->exp, dest)) | |
5023 | src_related = dest; | |
278a83b2 | 5024 | } |
7afe21cc RK |
5025 | |
5026 | /* Find the cheapest valid equivalent, trying all the available | |
5027 | possibilities. Prefer items not in the hash table to ones | |
5028 | that are when they are equal cost. Note that we can never | |
5029 | worsen an insn as the current contents will also succeed. | |
05c33dd8 | 5030 | If we find an equivalent identical to the destination, use it as best, |
0f41302f | 5031 | since this insn will probably be eliminated in that case. */ |
7afe21cc RK |
5032 | if (src) |
5033 | { | |
5034 | if (rtx_equal_p (src, dest)) | |
f1c1dfc3 | 5035 | src_cost = src_regcost = -1; |
7afe21cc | 5036 | else |
630c79be | 5037 | { |
e548c9df | 5038 | src_cost = COST (src, mode); |
630c79be BS |
5039 | src_regcost = approx_reg_cost (src); |
5040 | } | |
7afe21cc RK |
5041 | } |
5042 | ||
5043 | if (src_eqv_here) | |
5044 | { | |
5045 | if (rtx_equal_p (src_eqv_here, dest)) | |
f1c1dfc3 | 5046 | src_eqv_cost = src_eqv_regcost = -1; |
7afe21cc | 5047 | else |
630c79be | 5048 | { |
e548c9df | 5049 | src_eqv_cost = COST (src_eqv_here, mode); |
630c79be BS |
5050 | src_eqv_regcost = approx_reg_cost (src_eqv_here); |
5051 | } | |
7afe21cc RK |
5052 | } |
5053 | ||
5054 | if (src_folded) | |
5055 | { | |
5056 | if (rtx_equal_p (src_folded, dest)) | |
f1c1dfc3 | 5057 | src_folded_cost = src_folded_regcost = -1; |
7afe21cc | 5058 | else |
630c79be | 5059 | { |
e548c9df | 5060 | src_folded_cost = COST (src_folded, mode); |
630c79be BS |
5061 | src_folded_regcost = approx_reg_cost (src_folded); |
5062 | } | |
7afe21cc RK |
5063 | } |
5064 | ||
5065 | if (src_related) | |
5066 | { | |
5067 | if (rtx_equal_p (src_related, dest)) | |
f1c1dfc3 | 5068 | src_related_cost = src_related_regcost = -1; |
7afe21cc | 5069 | else |
630c79be | 5070 | { |
e548c9df | 5071 | src_related_cost = COST (src_related, mode); |
630c79be | 5072 | src_related_regcost = approx_reg_cost (src_related); |
2c5bfdf7 AN |
5073 | |
5074 | /* If a const-anchor is used to synthesize a constant that | |
5075 | normally requires multiple instructions then slightly prefer | |
5076 | it over the original sequence. These instructions are likely | |
5077 | to become redundant now. We can't compare against the cost | |
5078 | of src_eqv_here because, on MIPS for example, multi-insn | |
5079 | constants have zero cost; they are assumed to be hoisted from | |
5080 | loops. */ | |
5081 | if (src_related_is_const_anchor | |
5082 | && src_related_cost == src_cost | |
5083 | && src_eqv_here) | |
5084 | src_related_cost--; | |
630c79be | 5085 | } |
7afe21cc RK |
5086 | } |
5087 | ||
5088 | /* If this was an indirect jump insn, a known label will really be | |
5089 | cheaper even though it looks more expensive. */ | |
5090 | if (dest == pc_rtx && src_const && GET_CODE (src_const) == LABEL_REF) | |
99a9c946 | 5091 | src_folded = src_const, src_folded_cost = src_folded_regcost = -1; |
278a83b2 | 5092 | |
7afe21cc RK |
5093 | /* Terminate loop when replacement made. This must terminate since |
5094 | the current contents will be tested and will always be valid. */ | |
5095 | while (1) | |
278a83b2 KH |
5096 | { |
5097 | rtx trial; | |
7afe21cc | 5098 | |
278a83b2 | 5099 | /* Skip invalid entries. */ |
f8cfc6aa | 5100 | while (elt && !REG_P (elt->exp) |
0516f6fe | 5101 | && ! exp_equiv_p (elt->exp, elt->exp, 1, false)) |
278a83b2 | 5102 | elt = elt->next_same_value; |
5a03c8c4 RK |
5103 | |
5104 | /* A paradoxical subreg would be bad here: it'll be the right | |
5105 | size, but later may be adjusted so that the upper bits aren't | |
5106 | what we want. So reject it. */ | |
5107 | if (elt != 0 | |
6a4bdc79 | 5108 | && paradoxical_subreg_p (elt->exp) |
5a03c8c4 RK |
5109 | /* It is okay, though, if the rtx we're trying to match |
5110 | will ignore any of the bits we can't predict. */ | |
5111 | && ! (src != 0 | |
5112 | && GET_CODE (src) == SUBREG | |
5113 | && GET_MODE (src) == GET_MODE (elt->exp) | |
5114 | && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))) | |
5115 | < GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp)))))) | |
5116 | { | |
5117 | elt = elt->next_same_value; | |
5118 | continue; | |
5119 | } | |
278a83b2 | 5120 | |
68252e27 | 5121 | if (elt) |
630c79be BS |
5122 | { |
5123 | src_elt_cost = elt->cost; | |
5124 | src_elt_regcost = elt->regcost; | |
5125 | } | |
7afe21cc | 5126 | |
68252e27 | 5127 | /* Find cheapest and skip it for the next time. For items |
7afe21cc RK |
5128 | of equal cost, use this order: |
5129 | src_folded, src, src_eqv, src_related and hash table entry. */ | |
99a9c946 | 5130 | if (src_folded |
56ae04af KH |
5131 | && preferable (src_folded_cost, src_folded_regcost, |
5132 | src_cost, src_regcost) <= 0 | |
5133 | && preferable (src_folded_cost, src_folded_regcost, | |
5134 | src_eqv_cost, src_eqv_regcost) <= 0 | |
5135 | && preferable (src_folded_cost, src_folded_regcost, | |
5136 | src_related_cost, src_related_regcost) <= 0 | |
5137 | && preferable (src_folded_cost, src_folded_regcost, | |
5138 | src_elt_cost, src_elt_regcost) <= 0) | |
7afe21cc | 5139 | { |
f1c1dfc3 | 5140 | trial = src_folded, src_folded_cost = MAX_COST; |
7afe21cc | 5141 | if (src_folded_force_flag) |
9d8de1de EB |
5142 | { |
5143 | rtx forced = force_const_mem (mode, trial); | |
5144 | if (forced) | |
5145 | trial = forced; | |
5146 | } | |
7afe21cc | 5147 | } |
99a9c946 | 5148 | else if (src |
56ae04af KH |
5149 | && preferable (src_cost, src_regcost, |
5150 | src_eqv_cost, src_eqv_regcost) <= 0 | |
5151 | && preferable (src_cost, src_regcost, | |
5152 | src_related_cost, src_related_regcost) <= 0 | |
5153 | && preferable (src_cost, src_regcost, | |
5154 | src_elt_cost, src_elt_regcost) <= 0) | |
f1c1dfc3 | 5155 | trial = src, src_cost = MAX_COST; |
99a9c946 | 5156 | else if (src_eqv_here |
56ae04af KH |
5157 | && preferable (src_eqv_cost, src_eqv_regcost, |
5158 | src_related_cost, src_related_regcost) <= 0 | |
5159 | && preferable (src_eqv_cost, src_eqv_regcost, | |
5160 | src_elt_cost, src_elt_regcost) <= 0) | |
a36b8a1e | 5161 | trial = src_eqv_here, src_eqv_cost = MAX_COST; |
99a9c946 | 5162 | else if (src_related |
56ae04af KH |
5163 | && preferable (src_related_cost, src_related_regcost, |
5164 | src_elt_cost, src_elt_regcost) <= 0) | |
a36b8a1e | 5165 | trial = src_related, src_related_cost = MAX_COST; |
278a83b2 | 5166 | else |
7afe21cc | 5167 | { |
a36b8a1e | 5168 | trial = elt->exp; |
7afe21cc | 5169 | elt = elt->next_same_value; |
f1c1dfc3 | 5170 | src_elt_cost = MAX_COST; |
7afe21cc RK |
5171 | } |
5172 | ||
2e4e39f6 | 5173 | /* Avoid creation of overlapping memory moves. */ |
dd77684f | 5174 | if (MEM_P (trial) && MEM_P (dest) && !rtx_equal_p (trial, dest)) |
2e4e39f6 AK |
5175 | { |
5176 | rtx src, dest; | |
5177 | ||
5178 | /* BLKmode moves are not handled by cse anyway. */ | |
5179 | if (GET_MODE (trial) == BLKmode) | |
5180 | break; | |
5181 | ||
5182 | src = canon_rtx (trial); | |
5183 | dest = canon_rtx (SET_DEST (sets[i].rtl)); | |
5184 | ||
5185 | if (!MEM_P (src) || !MEM_P (dest) | |
c6ea834c | 5186 | || !nonoverlapping_memrefs_p (src, dest, false)) |
2e4e39f6 AK |
5187 | break; |
5188 | } | |
5189 | ||
b4ab701f JJ |
5190 | /* Try to optimize |
5191 | (set (reg:M N) (const_int A)) | |
5192 | (set (reg:M2 O) (const_int B)) | |
5193 | (set (zero_extract:M2 (reg:M N) (const_int C) (const_int D)) | |
5194 | (reg:M2 O)). */ | |
5195 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT | |
5196 | && CONST_INT_P (trial) | |
5197 | && CONST_INT_P (XEXP (SET_DEST (sets[i].rtl), 1)) | |
5198 | && CONST_INT_P (XEXP (SET_DEST (sets[i].rtl), 2)) | |
5199 | && REG_P (XEXP (SET_DEST (sets[i].rtl), 0)) | |
5511bc5a | 5200 | && (GET_MODE_PRECISION (GET_MODE (SET_DEST (sets[i].rtl))) |
b4ab701f JJ |
5201 | >= INTVAL (XEXP (SET_DEST (sets[i].rtl), 1))) |
5202 | && ((unsigned) INTVAL (XEXP (SET_DEST (sets[i].rtl), 1)) | |
5203 | + (unsigned) INTVAL (XEXP (SET_DEST (sets[i].rtl), 2)) | |
5204 | <= HOST_BITS_PER_WIDE_INT)) | |
5205 | { | |
5206 | rtx dest_reg = XEXP (SET_DEST (sets[i].rtl), 0); | |
5207 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
5208 | rtx pos = XEXP (SET_DEST (sets[i].rtl), 2); | |
5209 | unsigned int dest_hash = HASH (dest_reg, GET_MODE (dest_reg)); | |
5210 | struct table_elt *dest_elt | |
5211 | = lookup (dest_reg, dest_hash, GET_MODE (dest_reg)); | |
5212 | rtx dest_cst = NULL; | |
5213 | ||
5214 | if (dest_elt) | |
5215 | for (p = dest_elt->first_same_value; p; p = p->next_same_value) | |
5216 | if (p->is_const && CONST_INT_P (p->exp)) | |
5217 | { | |
5218 | dest_cst = p->exp; | |
5219 | break; | |
5220 | } | |
5221 | if (dest_cst) | |
5222 | { | |
5223 | HOST_WIDE_INT val = INTVAL (dest_cst); | |
5224 | HOST_WIDE_INT mask; | |
5225 | unsigned int shift; | |
5226 | if (BITS_BIG_ENDIAN) | |
5511bc5a | 5227 | shift = GET_MODE_PRECISION (GET_MODE (dest_reg)) |
b4ab701f JJ |
5228 | - INTVAL (pos) - INTVAL (width); |
5229 | else | |
5230 | shift = INTVAL (pos); | |
5231 | if (INTVAL (width) == HOST_BITS_PER_WIDE_INT) | |
dd4786fe | 5232 | mask = HOST_WIDE_INT_M1; |
b4ab701f | 5233 | else |
fecfbfa4 | 5234 | mask = (HOST_WIDE_INT_1 << INTVAL (width)) - 1; |
b4ab701f JJ |
5235 | val &= ~(mask << shift); |
5236 | val |= (INTVAL (trial) & mask) << shift; | |
5237 | val = trunc_int_for_mode (val, GET_MODE (dest_reg)); | |
5238 | validate_unshare_change (insn, &SET_DEST (sets[i].rtl), | |
5239 | dest_reg, 1); | |
5240 | validate_unshare_change (insn, &SET_SRC (sets[i].rtl), | |
5241 | GEN_INT (val), 1); | |
5242 | if (apply_change_group ()) | |
5243 | { | |
5244 | rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX); | |
5245 | if (note) | |
5246 | { | |
5247 | remove_note (insn, note); | |
5248 | df_notes_rescan (insn); | |
5249 | } | |
5250 | src_eqv = NULL_RTX; | |
5251 | src_eqv_elt = NULL; | |
5252 | src_eqv_volatile = 0; | |
5253 | src_eqv_in_memory = 0; | |
5254 | src_eqv_hash = 0; | |
5255 | repeat = true; | |
5256 | break; | |
5257 | } | |
5258 | } | |
5259 | } | |
5260 | ||
7afe21cc RK |
5261 | /* We don't normally have an insn matching (set (pc) (pc)), so |
5262 | check for this separately here. We will delete such an | |
5263 | insn below. | |
5264 | ||
d466c016 JL |
5265 | For other cases such as a table jump or conditional jump |
5266 | where we know the ultimate target, go ahead and replace the | |
5267 | operand. While that may not make a valid insn, we will | |
5268 | reemit the jump below (and also insert any necessary | |
5269 | barriers). */ | |
7afe21cc RK |
5270 | if (n_sets == 1 && dest == pc_rtx |
5271 | && (trial == pc_rtx | |
5272 | || (GET_CODE (trial) == LABEL_REF | |
5273 | && ! condjump_p (insn)))) | |
5274 | { | |
2f39b6ca UW |
5275 | /* Don't substitute non-local labels, this confuses CFG. */ |
5276 | if (GET_CODE (trial) == LABEL_REF | |
5277 | && LABEL_REF_NONLOCAL_P (trial)) | |
5278 | continue; | |
5279 | ||
d466c016 | 5280 | SET_SRC (sets[i].rtl) = trial; |
2aac3a01 | 5281 | cse_jumps_altered = true; |
7afe21cc RK |
5282 | break; |
5283 | } | |
278a83b2 | 5284 | |
dd77684f JJ |
5285 | /* Similarly, lots of targets don't allow no-op |
5286 | (set (mem x) (mem x)) moves. */ | |
5287 | else if (n_sets == 1 | |
5288 | && MEM_P (trial) | |
5289 | && MEM_P (dest) | |
5290 | && rtx_equal_p (trial, dest) | |
5291 | && !side_effects_p (dest) | |
5292 | && (cfun->can_delete_dead_exceptions | |
5293 | || insn_nothrow_p (insn))) | |
5294 | { | |
5295 | SET_SRC (sets[i].rtl) = trial; | |
5296 | mem_noop_insn = true; | |
5297 | break; | |
5298 | } | |
5299 | ||
1ef6855c KH |
5300 | /* Reject certain invalid forms of CONST that we create. */ |
5301 | else if (CONSTANT_P (trial) | |
5302 | && GET_CODE (trial) == CONST | |
5303 | /* Reject cases that will cause decode_rtx_const to | |
5304 | die. On the alpha when simplifying a switch, we | |
5305 | get (const (truncate (minus (label_ref) | |
5306 | (label_ref)))). */ | |
5307 | && (GET_CODE (XEXP (trial, 0)) == TRUNCATE | |
5308 | /* Likewise on IA-64, except without the | |
5309 | truncate. */ | |
5310 | || (GET_CODE (XEXP (trial, 0)) == MINUS | |
5311 | && GET_CODE (XEXP (XEXP (trial, 0), 0)) == LABEL_REF | |
5312 | && GET_CODE (XEXP (XEXP (trial, 0), 1)) == LABEL_REF))) | |
5313 | /* Do nothing for this case. */ | |
5314 | ; | |
5315 | ||
7afe21cc | 5316 | /* Look for a substitution that makes a valid insn. */ |
6c4d60f8 JJ |
5317 | else if (validate_unshare_change (insn, &SET_SRC (sets[i].rtl), |
5318 | trial, 0)) | |
05c33dd8 | 5319 | { |
32e9fa48 | 5320 | rtx new_rtx = canon_reg (SET_SRC (sets[i].rtl), insn); |
dbaff908 | 5321 | |
7722328e RK |
5322 | /* The result of apply_change_group can be ignored; see |
5323 | canon_reg. */ | |
5324 | ||
32e9fa48 | 5325 | validate_change (insn, &SET_SRC (sets[i].rtl), new_rtx, 1); |
6702af89 | 5326 | apply_change_group (); |
932ad4d9 | 5327 | |
05c33dd8 RK |
5328 | break; |
5329 | } | |
7afe21cc | 5330 | |
278a83b2 | 5331 | /* If we previously found constant pool entries for |
7afe21cc RK |
5332 | constants and this is a constant, try making a |
5333 | pool entry. Put it in src_folded unless we already have done | |
5334 | this since that is where it likely came from. */ | |
5335 | ||
5336 | else if (constant_pool_entries_cost | |
5337 | && CONSTANT_P (trial) | |
1bbd065b | 5338 | && (src_folded == 0 |
3c0cb5de | 5339 | || (!MEM_P (src_folded) |
1bbd065b | 5340 | && ! src_folded_force_flag)) |
9ae8ffe7 JL |
5341 | && GET_MODE_CLASS (mode) != MODE_CC |
5342 | && mode != VOIDmode) | |
7afe21cc RK |
5343 | { |
5344 | src_folded_force_flag = 1; | |
5345 | src_folded = trial; | |
5346 | src_folded_cost = constant_pool_entries_cost; | |
dd0ba281 | 5347 | src_folded_regcost = constant_pool_entries_regcost; |
7afe21cc | 5348 | } |
278a83b2 | 5349 | } |
7afe21cc | 5350 | |
b4ab701f JJ |
5351 | /* If we changed the insn too much, handle this set from scratch. */ |
5352 | if (repeat) | |
5353 | { | |
5354 | i--; | |
5355 | continue; | |
5356 | } | |
5357 | ||
7afe21cc RK |
5358 | src = SET_SRC (sets[i].rtl); |
5359 | ||
5360 | /* In general, it is good to have a SET with SET_SRC == SET_DEST. | |
5361 | However, there is an important exception: If both are registers | |
5362 | that are not the head of their equivalence class, replace SET_SRC | |
5363 | with the head of the class. If we do not do this, we will have | |
5364 | both registers live over a portion of the basic block. This way, | |
5365 | their lifetimes will likely abut instead of overlapping. */ | |
f8cfc6aa | 5366 | if (REG_P (dest) |
1bb98cec | 5367 | && REGNO_QTY_VALID_P (REGNO (dest))) |
7afe21cc | 5368 | { |
1bb98cec DM |
5369 | int dest_q = REG_QTY (REGNO (dest)); |
5370 | struct qty_table_elem *dest_ent = &qty_table[dest_q]; | |
5371 | ||
5372 | if (dest_ent->mode == GET_MODE (dest) | |
5373 | && dest_ent->first_reg != REGNO (dest) | |
f8cfc6aa | 5374 | && REG_P (src) && REGNO (src) == REGNO (dest) |
1bb98cec DM |
5375 | /* Don't do this if the original insn had a hard reg as |
5376 | SET_SRC or SET_DEST. */ | |
f8cfc6aa | 5377 | && (!REG_P (sets[i].src) |
1bb98cec | 5378 | || REGNO (sets[i].src) >= FIRST_PSEUDO_REGISTER) |
f8cfc6aa | 5379 | && (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER)) |
1bb98cec DM |
5380 | /* We can't call canon_reg here because it won't do anything if |
5381 | SRC is a hard register. */ | |
759bd8b7 | 5382 | { |
1bb98cec DM |
5383 | int src_q = REG_QTY (REGNO (src)); |
5384 | struct qty_table_elem *src_ent = &qty_table[src_q]; | |
5385 | int first = src_ent->first_reg; | |
5386 | rtx new_src | |
5387 | = (first >= FIRST_PSEUDO_REGISTER | |
5388 | ? regno_reg_rtx[first] : gen_rtx_REG (GET_MODE (src), first)); | |
5389 | ||
5390 | /* We must use validate-change even for this, because this | |
5391 | might be a special no-op instruction, suitable only to | |
5392 | tag notes onto. */ | |
5393 | if (validate_change (insn, &SET_SRC (sets[i].rtl), new_src, 0)) | |
5394 | { | |
5395 | src = new_src; | |
5396 | /* If we had a constant that is cheaper than what we are now | |
5397 | setting SRC to, use that constant. We ignored it when we | |
5398 | thought we could make this into a no-op. */ | |
e548c9df | 5399 | if (src_const && COST (src_const, mode) < COST (src, mode) |
278a83b2 KH |
5400 | && validate_change (insn, &SET_SRC (sets[i].rtl), |
5401 | src_const, 0)) | |
1bb98cec DM |
5402 | src = src_const; |
5403 | } | |
759bd8b7 | 5404 | } |
7afe21cc RK |
5405 | } |
5406 | ||
5407 | /* If we made a change, recompute SRC values. */ | |
5408 | if (src != sets[i].src) | |
278a83b2 | 5409 | { |
278a83b2 KH |
5410 | do_not_record = 0; |
5411 | hash_arg_in_memory = 0; | |
7afe21cc | 5412 | sets[i].src = src; |
278a83b2 KH |
5413 | sets[i].src_hash = HASH (src, mode); |
5414 | sets[i].src_volatile = do_not_record; | |
5415 | sets[i].src_in_memory = hash_arg_in_memory; | |
5416 | sets[i].src_elt = lookup (src, sets[i].src_hash, mode); | |
5417 | } | |
7afe21cc RK |
5418 | |
5419 | /* If this is a single SET, we are setting a register, and we have an | |
73dd3123 EB |
5420 | equivalent constant, we want to add a REG_EQUAL note if the constant |
5421 | is different from the source. We don't want to do it for a constant | |
5422 | pseudo since verifying that this pseudo hasn't been eliminated is a | |
5423 | pain; moreover such a note won't help anything. | |
ac7ef8d5 FS |
5424 | |
5425 | Avoid a REG_EQUAL note for (CONST (MINUS (LABEL_REF) (LABEL_REF))) | |
5426 | which can be created for a reference to a compile time computable | |
5427 | entry in a jump table. */ | |
73dd3123 EB |
5428 | if (n_sets == 1 |
5429 | && REG_P (dest) | |
5430 | && src_const | |
f8cfc6aa | 5431 | && !REG_P (src_const) |
73dd3123 EB |
5432 | && !(GET_CODE (src_const) == SUBREG |
5433 | && REG_P (SUBREG_REG (src_const))) | |
5434 | && !(GET_CODE (src_const) == CONST | |
5435 | && GET_CODE (XEXP (src_const, 0)) == MINUS | |
5436 | && GET_CODE (XEXP (XEXP (src_const, 0), 0)) == LABEL_REF | |
5437 | && GET_CODE (XEXP (XEXP (src_const, 0), 1)) == LABEL_REF) | |
5438 | && !rtx_equal_p (src, src_const)) | |
7afe21cc | 5439 | { |
73dd3123 EB |
5440 | /* Make sure that the rtx is not shared. */ |
5441 | src_const = copy_rtx (src_const); | |
51e2a951 | 5442 | |
73dd3123 EB |
5443 | /* Record the actual constant value in a REG_EQUAL note, |
5444 | making a new one if one does not already exist. */ | |
5445 | set_unique_reg_note (insn, REG_EQUAL, src_const); | |
5446 | df_notes_rescan (insn); | |
7afe21cc RK |
5447 | } |
5448 | ||
5449 | /* Now deal with the destination. */ | |
5450 | do_not_record = 0; | |
7afe21cc | 5451 | |
46d096a3 SB |
5452 | /* Look within any ZERO_EXTRACT to the MEM or REG within it. */ |
5453 | while (GET_CODE (dest) == SUBREG | |
7afe21cc | 5454 | || GET_CODE (dest) == ZERO_EXTRACT |
7afe21cc | 5455 | || GET_CODE (dest) == STRICT_LOW_PART) |
0339ce7e | 5456 | dest = XEXP (dest, 0); |
7afe21cc RK |
5457 | |
5458 | sets[i].inner_dest = dest; | |
5459 | ||
3c0cb5de | 5460 | if (MEM_P (dest)) |
7afe21cc | 5461 | { |
9ae8ffe7 JL |
5462 | #ifdef PUSH_ROUNDING |
5463 | /* Stack pushes invalidate the stack pointer. */ | |
5464 | rtx addr = XEXP (dest, 0); | |
ec8e098d | 5465 | if (GET_RTX_CLASS (GET_CODE (addr)) == RTX_AUTOINC |
9ae8ffe7 | 5466 | && XEXP (addr, 0) == stack_pointer_rtx) |
524e3576 | 5467 | invalidate (stack_pointer_rtx, VOIDmode); |
9ae8ffe7 | 5468 | #endif |
7afe21cc | 5469 | dest = fold_rtx (dest, insn); |
7afe21cc RK |
5470 | } |
5471 | ||
5472 | /* Compute the hash code of the destination now, | |
5473 | before the effects of this instruction are recorded, | |
5474 | since the register values used in the address computation | |
5475 | are those before this instruction. */ | |
2197a88a | 5476 | sets[i].dest_hash = HASH (dest, mode); |
7afe21cc RK |
5477 | |
5478 | /* Don't enter a bit-field in the hash table | |
5479 | because the value in it after the store | |
5480 | may not equal what was stored, due to truncation. */ | |
5481 | ||
46d096a3 | 5482 | if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT) |
7afe21cc RK |
5483 | { |
5484 | rtx width = XEXP (SET_DEST (sets[i].rtl), 1); | |
5485 | ||
481683e1 SZ |
5486 | if (src_const != 0 && CONST_INT_P (src_const) |
5487 | && CONST_INT_P (width) | |
906c4e36 RK |
5488 | && INTVAL (width) < HOST_BITS_PER_WIDE_INT |
5489 | && ! (INTVAL (src_const) | |
0cadbfaa | 5490 | & (HOST_WIDE_INT_M1U << INTVAL (width)))) |
7afe21cc RK |
5491 | /* Exception: if the value is constant, |
5492 | and it won't be truncated, record it. */ | |
5493 | ; | |
5494 | else | |
5495 | { | |
5496 | /* This is chosen so that the destination will be invalidated | |
5497 | but no new value will be recorded. | |
5498 | We must invalidate because sometimes constant | |
5499 | values can be recorded for bitfields. */ | |
5500 | sets[i].src_elt = 0; | |
5501 | sets[i].src_volatile = 1; | |
5502 | src_eqv = 0; | |
5503 | src_eqv_elt = 0; | |
5504 | } | |
5505 | } | |
5506 | ||
5507 | /* If only one set in a JUMP_INSN and it is now a no-op, we can delete | |
5508 | the insn. */ | |
5509 | else if (n_sets == 1 && dest == pc_rtx && src == pc_rtx) | |
5510 | { | |
ef178af3 | 5511 | /* One less use of the label this insn used to jump to. */ |
98ccd1d7 | 5512 | cse_cfg_altered |= delete_insn_and_edges (insn); |
2aac3a01 | 5513 | cse_jumps_altered = true; |
7afe21cc RK |
5514 | /* No more processing for this set. */ |
5515 | sets[i].rtl = 0; | |
5516 | } | |
5517 | ||
dd77684f JJ |
5518 | /* Similarly for no-op MEM moves. */ |
5519 | else if (mem_noop_insn) | |
5520 | { | |
5521 | if (cfun->can_throw_non_call_exceptions && can_throw_internal (insn)) | |
5522 | cse_cfg_altered = true; | |
98ccd1d7 | 5523 | cse_cfg_altered |= delete_insn_and_edges (insn); |
dd77684f JJ |
5524 | /* No more processing for this set. */ |
5525 | sets[i].rtl = 0; | |
5526 | } | |
5527 | ||
7afe21cc | 5528 | /* If this SET is now setting PC to a label, we know it used to |
d466c016 | 5529 | be a conditional or computed branch. */ |
8f235343 JH |
5530 | else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF |
5531 | && !LABEL_REF_NONLOCAL_P (src)) | |
7afe21cc | 5532 | { |
d466c016 JL |
5533 | /* We reemit the jump in as many cases as possible just in |
5534 | case the form of an unconditional jump is significantly | |
5535 | different than a computed jump or conditional jump. | |
5536 | ||
5537 | If this insn has multiple sets, then reemitting the | |
5538 | jump is nontrivial. So instead we just force rerecognition | |
5539 | and hope for the best. */ | |
5540 | if (n_sets == 1) | |
7afe21cc | 5541 | { |
e67d1102 | 5542 | rtx_jump_insn *new_rtx; |
49506606 | 5543 | rtx note; |
8fb1e50e | 5544 | |
ec4a505f RS |
5545 | rtx_insn *seq = targetm.gen_jump (XEXP (src, 0)); |
5546 | new_rtx = emit_jump_insn_before (seq, insn); | |
32e9fa48 | 5547 | JUMP_LABEL (new_rtx) = XEXP (src, 0); |
7afe21cc | 5548 | LABEL_NUSES (XEXP (src, 0))++; |
9dcb4381 RH |
5549 | |
5550 | /* Make sure to copy over REG_NON_LOCAL_GOTO. */ | |
5551 | note = find_reg_note (insn, REG_NON_LOCAL_GOTO, 0); | |
5552 | if (note) | |
5553 | { | |
5554 | XEXP (note, 1) = NULL_RTX; | |
32e9fa48 | 5555 | REG_NOTES (new_rtx) = note; |
9dcb4381 RH |
5556 | } |
5557 | ||
98ccd1d7 | 5558 | cse_cfg_altered |= delete_insn_and_edges (insn); |
49506606 | 5559 | insn = new_rtx; |
7afe21cc | 5560 | } |
31dcf83f | 5561 | else |
31dcf83f | 5562 | INSN_CODE (insn) = -1; |
7afe21cc | 5563 | |
2aac3a01 EB |
5564 | /* Do not bother deleting any unreachable code, let jump do it. */ |
5565 | cse_jumps_altered = true; | |
7afe21cc RK |
5566 | sets[i].rtl = 0; |
5567 | } | |
5568 | ||
c2a47e48 RK |
5569 | /* If destination is volatile, invalidate it and then do no further |
5570 | processing for this assignment. */ | |
7afe21cc RK |
5571 | |
5572 | else if (do_not_record) | |
c2a47e48 | 5573 | { |
2a1d78d8 | 5574 | invalidate_dest (dest); |
c2a47e48 RK |
5575 | sets[i].rtl = 0; |
5576 | } | |
7afe21cc RK |
5577 | |
5578 | if (sets[i].rtl != 0 && dest != SET_DEST (sets[i].rtl)) | |
2a1d78d8 JJ |
5579 | { |
5580 | do_not_record = 0; | |
5581 | sets[i].dest_hash = HASH (SET_DEST (sets[i].rtl), mode); | |
5582 | if (do_not_record) | |
5583 | { | |
5584 | invalidate_dest (SET_DEST (sets[i].rtl)); | |
5585 | sets[i].rtl = 0; | |
5586 | } | |
5587 | } | |
7afe21cc | 5588 | |
7afe21cc RK |
5589 | /* If setting CC0, record what it was set to, or a constant, if it |
5590 | is equivalent to a constant. If it is being set to a floating-point | |
5591 | value, make a COMPARE with the appropriate constant of 0. If we | |
5592 | don't do this, later code can interpret this as a test against | |
5593 | const0_rtx, which can cause problems if we try to put it into an | |
5594 | insn as a floating-point operand. */ | |
5595 | if (dest == cc0_rtx) | |
5596 | { | |
5597 | this_insn_cc0 = src_const && mode != VOIDmode ? src_const : src; | |
5598 | this_insn_cc0_mode = mode; | |
cbf6a543 | 5599 | if (FLOAT_MODE_P (mode)) |
38a448ca RH |
5600 | this_insn_cc0 = gen_rtx_COMPARE (VOIDmode, this_insn_cc0, |
5601 | CONST0_RTX (mode)); | |
7afe21cc | 5602 | } |
7afe21cc RK |
5603 | } |
5604 | ||
5605 | /* Now enter all non-volatile source expressions in the hash table | |
5606 | if they are not already present. | |
5607 | Record their equivalence classes in src_elt. | |
5608 | This way we can insert the corresponding destinations into | |
5609 | the same classes even if the actual sources are no longer in them | |
5610 | (having been invalidated). */ | |
5611 | ||
5612 | if (src_eqv && src_eqv_elt == 0 && sets[0].rtl != 0 && ! src_eqv_volatile | |
5613 | && ! rtx_equal_p (src_eqv, SET_DEST (sets[0].rtl))) | |
5614 | { | |
b3694847 SS |
5615 | struct table_elt *elt; |
5616 | struct table_elt *classp = sets[0].src_elt; | |
7afe21cc | 5617 | rtx dest = SET_DEST (sets[0].rtl); |
ef4bddc2 | 5618 | machine_mode eqvmode = GET_MODE (dest); |
7afe21cc RK |
5619 | |
5620 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
5621 | { | |
5622 | eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0))); | |
5623 | classp = 0; | |
5624 | } | |
5625 | if (insert_regs (src_eqv, classp, 0)) | |
8ae2b8f6 JW |
5626 | { |
5627 | rehash_using_reg (src_eqv); | |
5628 | src_eqv_hash = HASH (src_eqv, eqvmode); | |
5629 | } | |
2197a88a | 5630 | elt = insert (src_eqv, classp, src_eqv_hash, eqvmode); |
7afe21cc | 5631 | elt->in_memory = src_eqv_in_memory; |
7afe21cc | 5632 | src_eqv_elt = elt; |
f7911249 JW |
5633 | |
5634 | /* Check to see if src_eqv_elt is the same as a set source which | |
5635 | does not yet have an elt, and if so set the elt of the set source | |
5636 | to src_eqv_elt. */ | |
5637 | for (i = 0; i < n_sets; i++) | |
26132f71 JW |
5638 | if (sets[i].rtl && sets[i].src_elt == 0 |
5639 | && rtx_equal_p (SET_SRC (sets[i].rtl), src_eqv)) | |
f7911249 | 5640 | sets[i].src_elt = src_eqv_elt; |
7afe21cc RK |
5641 | } |
5642 | ||
5643 | for (i = 0; i < n_sets; i++) | |
5644 | if (sets[i].rtl && ! sets[i].src_volatile | |
5645 | && ! rtx_equal_p (SET_SRC (sets[i].rtl), SET_DEST (sets[i].rtl))) | |
5646 | { | |
5647 | if (GET_CODE (SET_DEST (sets[i].rtl)) == STRICT_LOW_PART) | |
5648 | { | |
5649 | /* REG_EQUAL in setting a STRICT_LOW_PART | |
5650 | gives an equivalent for the entire destination register, | |
5651 | not just for the subreg being stored in now. | |
5652 | This is a more interesting equivalence, so we arrange later | |
5653 | to treat the entire reg as the destination. */ | |
5654 | sets[i].src_elt = src_eqv_elt; | |
2197a88a | 5655 | sets[i].src_hash = src_eqv_hash; |
7afe21cc RK |
5656 | } |
5657 | else | |
5658 | { | |
5659 | /* Insert source and constant equivalent into hash table, if not | |
5660 | already present. */ | |
b3694847 SS |
5661 | struct table_elt *classp = src_eqv_elt; |
5662 | rtx src = sets[i].src; | |
5663 | rtx dest = SET_DEST (sets[i].rtl); | |
ef4bddc2 | 5664 | machine_mode mode |
7afe21cc RK |
5665 | = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src); |
5666 | ||
1fcc57f1 AM |
5667 | /* It's possible that we have a source value known to be |
5668 | constant but don't have a REG_EQUAL note on the insn. | |
5669 | Lack of a note will mean src_eqv_elt will be NULL. This | |
5670 | can happen where we've generated a SUBREG to access a | |
5671 | CONST_INT that is already in a register in a wider mode. | |
5672 | Ensure that the source expression is put in the proper | |
5673 | constant class. */ | |
5674 | if (!classp) | |
5675 | classp = sets[i].src_const_elt; | |
5676 | ||
26132f71 | 5677 | if (sets[i].src_elt == 0) |
7afe21cc | 5678 | { |
4a8cae83 | 5679 | struct table_elt *elt; |
26132f71 | 5680 | |
4a8cae83 SB |
5681 | /* Note that these insert_regs calls cannot remove |
5682 | any of the src_elt's, because they would have failed to | |
5683 | match if not still valid. */ | |
5684 | if (insert_regs (src, classp, 0)) | |
5685 | { | |
5686 | rehash_using_reg (src); | |
5687 | sets[i].src_hash = HASH (src, mode); | |
8ae2b8f6 | 5688 | } |
4a8cae83 SB |
5689 | elt = insert (src, classp, sets[i].src_hash, mode); |
5690 | elt->in_memory = sets[i].src_in_memory; | |
6c4d60f8 JJ |
5691 | /* If inline asm has any clobbers, ensure we only reuse |
5692 | existing inline asms and never try to put the ASM_OPERANDS | |
5693 | into an insn that isn't inline asm. */ | |
5694 | if (GET_CODE (src) == ASM_OPERANDS | |
5695 | && GET_CODE (x) == PARALLEL) | |
5696 | elt->cost = MAX_COST; | |
4a8cae83 | 5697 | sets[i].src_elt = classp = elt; |
7afe21cc | 5698 | } |
7afe21cc RK |
5699 | if (sets[i].src_const && sets[i].src_const_elt == 0 |
5700 | && src != sets[i].src_const | |
5701 | && ! rtx_equal_p (sets[i].src_const, src)) | |
5702 | sets[i].src_elt = insert (sets[i].src_const, classp, | |
2197a88a | 5703 | sets[i].src_const_hash, mode); |
7afe21cc RK |
5704 | } |
5705 | } | |
5706 | else if (sets[i].src_elt == 0) | |
5707 | /* If we did not insert the source into the hash table (e.g., it was | |
5708 | volatile), note the equivalence class for the REG_EQUAL value, if any, | |
5709 | so that the destination goes into that class. */ | |
5710 | sets[i].src_elt = src_eqv_elt; | |
5711 | ||
05c433f3 PB |
5712 | /* Record destination addresses in the hash table. This allows us to |
5713 | check if they are invalidated by other sets. */ | |
5714 | for (i = 0; i < n_sets; i++) | |
5715 | { | |
5716 | if (sets[i].rtl) | |
5717 | { | |
5718 | rtx x = sets[i].inner_dest; | |
5719 | struct table_elt *elt; | |
ef4bddc2 | 5720 | machine_mode mode; |
05c433f3 PB |
5721 | unsigned hash; |
5722 | ||
5723 | if (MEM_P (x)) | |
5724 | { | |
5725 | x = XEXP (x, 0); | |
5726 | mode = GET_MODE (x); | |
5727 | hash = HASH (x, mode); | |
5728 | elt = lookup (x, hash, mode); | |
5729 | if (!elt) | |
5730 | { | |
5731 | if (insert_regs (x, NULL, 0)) | |
5732 | { | |
7e7e28c7 AO |
5733 | rtx dest = SET_DEST (sets[i].rtl); |
5734 | ||
05c433f3 PB |
5735 | rehash_using_reg (x); |
5736 | hash = HASH (x, mode); | |
7e7e28c7 | 5737 | sets[i].dest_hash = HASH (dest, GET_MODE (dest)); |
05c433f3 PB |
5738 | } |
5739 | elt = insert (x, NULL, hash, mode); | |
5740 | } | |
5741 | ||
5742 | sets[i].dest_addr_elt = elt; | |
5743 | } | |
5744 | else | |
5745 | sets[i].dest_addr_elt = NULL; | |
5746 | } | |
5747 | } | |
5748 | ||
7b02f4e0 | 5749 | invalidate_from_clobbers (insn); |
77fa0940 | 5750 | |
278a83b2 | 5751 | /* Some registers are invalidated by subroutine calls. Memory is |
77fa0940 RK |
5752 | invalidated by non-constant calls. */ |
5753 | ||
4b4bf941 | 5754 | if (CALL_P (insn)) |
7afe21cc | 5755 | { |
becfd6e5 | 5756 | if (!(RTL_CONST_OR_PURE_CALL_P (insn))) |
9ae8ffe7 | 5757 | invalidate_memory (); |
67c25816 JJ |
5758 | else |
5759 | /* For const/pure calls, invalidate any argument slots, because | |
5760 | those are owned by the callee. */ | |
5761 | for (tem = CALL_INSN_FUNCTION_USAGE (insn); tem; tem = XEXP (tem, 1)) | |
5762 | if (GET_CODE (XEXP (tem, 0)) == USE | |
5763 | && MEM_P (XEXP (XEXP (tem, 0), 0))) | |
5764 | invalidate (XEXP (XEXP (tem, 0), 0), VOIDmode); | |
7afe21cc RK |
5765 | invalidate_for_call (); |
5766 | } | |
5767 | ||
5768 | /* Now invalidate everything set by this instruction. | |
5769 | If a SUBREG or other funny destination is being set, | |
5770 | sets[i].rtl is still nonzero, so here we invalidate the reg | |
5771 | a part of which is being set. */ | |
5772 | ||
5773 | for (i = 0; i < n_sets; i++) | |
5774 | if (sets[i].rtl) | |
5775 | { | |
bb4034b3 JW |
5776 | /* We can't use the inner dest, because the mode associated with |
5777 | a ZERO_EXTRACT is significant. */ | |
b3694847 | 5778 | rtx dest = SET_DEST (sets[i].rtl); |
7afe21cc RK |
5779 | |
5780 | /* Needed for registers to remove the register from its | |
5781 | previous quantity's chain. | |
5782 | Needed for memory if this is a nonvarying address, unless | |
5783 | we have just done an invalidate_memory that covers even those. */ | |
f8cfc6aa | 5784 | if (REG_P (dest) || GET_CODE (dest) == SUBREG) |
bb4034b3 | 5785 | invalidate (dest, VOIDmode); |
3c0cb5de | 5786 | else if (MEM_P (dest)) |
32fab725 | 5787 | invalidate (dest, VOIDmode); |
2708da92 RS |
5788 | else if (GET_CODE (dest) == STRICT_LOW_PART |
5789 | || GET_CODE (dest) == ZERO_EXTRACT) | |
bb4034b3 | 5790 | invalidate (XEXP (dest, 0), GET_MODE (dest)); |
7afe21cc RK |
5791 | } |
5792 | ||
932ad4d9 SB |
5793 | /* Don't cse over a call to setjmp; on some machines (eg VAX) |
5794 | the regs restored by the longjmp come from a later time | |
5795 | than the setjmp. */ | |
5796 | if (CALL_P (insn) && find_reg_note (insn, REG_SETJMP, NULL)) | |
5797 | { | |
5798 | flush_hash_table (); | |
5799 | goto done; | |
5800 | } | |
5801 | ||
7afe21cc RK |
5802 | /* Make sure registers mentioned in destinations |
5803 | are safe for use in an expression to be inserted. | |
5804 | This removes from the hash table | |
5805 | any invalid entry that refers to one of these registers. | |
5806 | ||
5807 | We don't care about the return value from mention_regs because | |
5808 | we are going to hash the SET_DEST values unconditionally. */ | |
5809 | ||
5810 | for (i = 0; i < n_sets; i++) | |
34c73909 R |
5811 | { |
5812 | if (sets[i].rtl) | |
5813 | { | |
5814 | rtx x = SET_DEST (sets[i].rtl); | |
5815 | ||
f8cfc6aa | 5816 | if (!REG_P (x)) |
34c73909 R |
5817 | mention_regs (x); |
5818 | else | |
5819 | { | |
5820 | /* We used to rely on all references to a register becoming | |
5821 | inaccessible when a register changes to a new quantity, | |
5822 | since that changes the hash code. However, that is not | |
9b1549b8 | 5823 | safe, since after HASH_SIZE new quantities we get a |
34c73909 R |
5824 | hash 'collision' of a register with its own invalid |
5825 | entries. And since SUBREGs have been changed not to | |
5826 | change their hash code with the hash code of the register, | |
5827 | it wouldn't work any longer at all. So we have to check | |
5828 | for any invalid references lying around now. | |
5829 | This code is similar to the REG case in mention_regs, | |
5830 | but it knows that reg_tick has been incremented, and | |
5831 | it leaves reg_in_table as -1 . */ | |
770ae6cc | 5832 | unsigned int regno = REGNO (x); |
09e18274 | 5833 | unsigned int endregno = END_REGNO (x); |
770ae6cc | 5834 | unsigned int i; |
34c73909 R |
5835 | |
5836 | for (i = regno; i < endregno; i++) | |
5837 | { | |
30f72379 | 5838 | if (REG_IN_TABLE (i) >= 0) |
34c73909 R |
5839 | { |
5840 | remove_invalid_refs (i); | |
30f72379 | 5841 | REG_IN_TABLE (i) = -1; |
34c73909 R |
5842 | } |
5843 | } | |
5844 | } | |
5845 | } | |
5846 | } | |
7afe21cc RK |
5847 | |
5848 | /* We may have just removed some of the src_elt's from the hash table. | |
05c433f3 PB |
5849 | So replace each one with the current head of the same class. |
5850 | Also check if destination addresses have been removed. */ | |
7afe21cc RK |
5851 | |
5852 | for (i = 0; i < n_sets; i++) | |
5853 | if (sets[i].rtl) | |
5854 | { | |
05c433f3 PB |
5855 | if (sets[i].dest_addr_elt |
5856 | && sets[i].dest_addr_elt->first_same_value == 0) | |
5857 | { | |
e67b81d1 | 5858 | /* The elt was removed, which means this destination is not |
05c433f3 PB |
5859 | valid after this instruction. */ |
5860 | sets[i].rtl = NULL_RTX; | |
5861 | } | |
5862 | else if (sets[i].src_elt && sets[i].src_elt->first_same_value == 0) | |
7afe21cc RK |
5863 | /* If elt was removed, find current head of same class, |
5864 | or 0 if nothing remains of that class. */ | |
5865 | { | |
b3694847 | 5866 | struct table_elt *elt = sets[i].src_elt; |
7afe21cc RK |
5867 | |
5868 | while (elt && elt->prev_same_value) | |
5869 | elt = elt->prev_same_value; | |
5870 | ||
5871 | while (elt && elt->first_same_value == 0) | |
5872 | elt = elt->next_same_value; | |
5873 | sets[i].src_elt = elt ? elt->first_same_value : 0; | |
5874 | } | |
5875 | } | |
5876 | ||
5877 | /* Now insert the destinations into their equivalence classes. */ | |
5878 | ||
5879 | for (i = 0; i < n_sets; i++) | |
5880 | if (sets[i].rtl) | |
5881 | { | |
b3694847 | 5882 | rtx dest = SET_DEST (sets[i].rtl); |
b3694847 | 5883 | struct table_elt *elt; |
7afe21cc RK |
5884 | |
5885 | /* Don't record value if we are not supposed to risk allocating | |
5886 | floating-point values in registers that might be wider than | |
5887 | memory. */ | |
5888 | if ((flag_float_store | |
3c0cb5de | 5889 | && MEM_P (dest) |
cbf6a543 | 5890 | && FLOAT_MODE_P (GET_MODE (dest))) |
bc4ddc77 JW |
5891 | /* Don't record BLKmode values, because we don't know the |
5892 | size of it, and can't be sure that other BLKmode values | |
5893 | have the same or smaller size. */ | |
5894 | || GET_MODE (dest) == BLKmode | |
7afe21cc RK |
5895 | /* If we didn't put a REG_EQUAL value or a source into the hash |
5896 | table, there is no point is recording DEST. */ | |
086ad22e | 5897 | || sets[i].src_elt == 0) |
7afe21cc RK |
5898 | continue; |
5899 | ||
5900 | /* STRICT_LOW_PART isn't part of the value BEING set, | |
5901 | and neither is the SUBREG inside it. | |
5902 | Note that in this case SETS[I].SRC_ELT is really SRC_EQV_ELT. */ | |
5903 | if (GET_CODE (dest) == STRICT_LOW_PART) | |
5904 | dest = SUBREG_REG (XEXP (dest, 0)); | |
5905 | ||
f8cfc6aa | 5906 | if (REG_P (dest) || GET_CODE (dest) == SUBREG) |
7afe21cc RK |
5907 | /* Registers must also be inserted into chains for quantities. */ |
5908 | if (insert_regs (dest, sets[i].src_elt, 1)) | |
8ae2b8f6 JW |
5909 | { |
5910 | /* If `insert_regs' changes something, the hash code must be | |
5911 | recalculated. */ | |
5912 | rehash_using_reg (dest); | |
5913 | sets[i].dest_hash = HASH (dest, GET_MODE (dest)); | |
5914 | } | |
7afe21cc | 5915 | |
086ad22e BE |
5916 | /* If DEST is a paradoxical SUBREG, don't record DEST since the bits |
5917 | outside the mode of GET_MODE (SUBREG_REG (dest)) are undefined. */ | |
5918 | if (paradoxical_subreg_p (dest)) | |
5919 | continue; | |
5920 | ||
8fff4fc1 RH |
5921 | elt = insert (dest, sets[i].src_elt, |
5922 | sets[i].dest_hash, GET_MODE (dest)); | |
9de2c71a | 5923 | |
2c5bfdf7 AN |
5924 | /* If this is a constant, insert the constant anchors with the |
5925 | equivalent register-offset expressions using register DEST. */ | |
5926 | if (targetm.const_anchor | |
5927 | && REG_P (dest) | |
5928 | && SCALAR_INT_MODE_P (GET_MODE (dest)) | |
5929 | && GET_CODE (sets[i].src_elt->exp) == CONST_INT) | |
5930 | insert_const_anchors (dest, sets[i].src_elt->exp, GET_MODE (dest)); | |
5931 | ||
3c0cb5de | 5932 | elt->in_memory = (MEM_P (sets[i].inner_dest) |
389fdba0 | 5933 | && !MEM_READONLY_P (sets[i].inner_dest)); |
c256df0b | 5934 | |
fc3ffe83 RK |
5935 | /* If we have (set (subreg:m1 (reg:m2 foo) 0) (bar:m1)), M1 is no |
5936 | narrower than M2, and both M1 and M2 are the same number of words, | |
5937 | we are also doing (set (reg:m2 foo) (subreg:m2 (bar:m1) 0)) so | |
5938 | make that equivalence as well. | |
7afe21cc | 5939 | |
4de249d9 PB |
5940 | However, BAR may have equivalences for which gen_lowpart |
5941 | will produce a simpler value than gen_lowpart applied to | |
7afe21cc | 5942 | BAR (e.g., if BAR was ZERO_EXTENDed from M2), so we will scan all |
278a83b2 | 5943 | BAR's equivalences. If we don't get a simplified form, make |
7afe21cc RK |
5944 | the SUBREG. It will not be used in an equivalence, but will |
5945 | cause two similar assignments to be detected. | |
5946 | ||
5947 | Note the loop below will find SUBREG_REG (DEST) since we have | |
5948 | already entered SRC and DEST of the SET in the table. */ | |
5949 | ||
5950 | if (GET_CODE (dest) == SUBREG | |
6cdbaec4 RK |
5951 | && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) - 1) |
5952 | / UNITS_PER_WORD) | |
278a83b2 | 5953 | == (GET_MODE_SIZE (GET_MODE (dest)) - 1) / UNITS_PER_WORD) |
7afe21cc RK |
5954 | && (GET_MODE_SIZE (GET_MODE (dest)) |
5955 | >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))) | |
5956 | && sets[i].src_elt != 0) | |
5957 | { | |
ef4bddc2 | 5958 | machine_mode new_mode = GET_MODE (SUBREG_REG (dest)); |
7afe21cc RK |
5959 | struct table_elt *elt, *classp = 0; |
5960 | ||
5961 | for (elt = sets[i].src_elt->first_same_value; elt; | |
5962 | elt = elt->next_same_value) | |
5963 | { | |
5964 | rtx new_src = 0; | |
2197a88a | 5965 | unsigned src_hash; |
7afe21cc | 5966 | struct table_elt *src_elt; |
ff27a429 | 5967 | int byte = 0; |
7afe21cc RK |
5968 | |
5969 | /* Ignore invalid entries. */ | |
f8cfc6aa | 5970 | if (!REG_P (elt->exp) |
0516f6fe | 5971 | && ! exp_equiv_p (elt->exp, elt->exp, 1, false)) |
7afe21cc RK |
5972 | continue; |
5973 | ||
9beb7d20 RH |
5974 | /* We may have already been playing subreg games. If the |
5975 | mode is already correct for the destination, use it. */ | |
5976 | if (GET_MODE (elt->exp) == new_mode) | |
5977 | new_src = elt->exp; | |
5978 | else | |
5979 | { | |
5980 | /* Calculate big endian correction for the SUBREG_BYTE. | |
5981 | We have already checked that M1 (GET_MODE (dest)) | |
5982 | is not narrower than M2 (new_mode). */ | |
5983 | if (BYTES_BIG_ENDIAN) | |
5984 | byte = (GET_MODE_SIZE (GET_MODE (dest)) | |
5985 | - GET_MODE_SIZE (new_mode)); | |
5986 | ||
5987 | new_src = simplify_gen_subreg (new_mode, elt->exp, | |
5988 | GET_MODE (dest), byte); | |
5989 | } | |
5990 | ||
ff27a429 R |
5991 | /* The call to simplify_gen_subreg fails if the value |
5992 | is VOIDmode, yet we can't do any simplification, e.g. | |
5993 | for EXPR_LISTs denoting function call results. | |
5994 | It is invalid to construct a SUBREG with a VOIDmode | |
5995 | SUBREG_REG, hence a zero new_src means we can't do | |
5996 | this substitution. */ | |
5997 | if (! new_src) | |
5998 | continue; | |
7afe21cc RK |
5999 | |
6000 | src_hash = HASH (new_src, new_mode); | |
6001 | src_elt = lookup (new_src, src_hash, new_mode); | |
6002 | ||
6003 | /* Put the new source in the hash table is if isn't | |
6004 | already. */ | |
6005 | if (src_elt == 0) | |
6006 | { | |
6007 | if (insert_regs (new_src, classp, 0)) | |
8ae2b8f6 JW |
6008 | { |
6009 | rehash_using_reg (new_src); | |
6010 | src_hash = HASH (new_src, new_mode); | |
6011 | } | |
7afe21cc RK |
6012 | src_elt = insert (new_src, classp, src_hash, new_mode); |
6013 | src_elt->in_memory = elt->in_memory; | |
6c4d60f8 JJ |
6014 | if (GET_CODE (new_src) == ASM_OPERANDS |
6015 | && elt->cost == MAX_COST) | |
6016 | src_elt->cost = MAX_COST; | |
7afe21cc RK |
6017 | } |
6018 | else if (classp && classp != src_elt->first_same_value) | |
278a83b2 | 6019 | /* Show that two things that we've seen before are |
7afe21cc RK |
6020 | actually the same. */ |
6021 | merge_equiv_classes (src_elt, classp); | |
6022 | ||
6023 | classp = src_elt->first_same_value; | |
da932f04 JL |
6024 | /* Ignore invalid entries. */ |
6025 | while (classp | |
f8cfc6aa | 6026 | && !REG_P (classp->exp) |
0516f6fe | 6027 | && ! exp_equiv_p (classp->exp, classp->exp, 1, false)) |
da932f04 | 6028 | classp = classp->next_same_value; |
7afe21cc RK |
6029 | } |
6030 | } | |
6031 | } | |
6032 | ||
403e25d0 RK |
6033 | /* Special handling for (set REG0 REG1) where REG0 is the |
6034 | "cheapest", cheaper than REG1. After cse, REG1 will probably not | |
6035 | be used in the sequel, so (if easily done) change this insn to | |
6036 | (set REG1 REG0) and replace REG1 with REG0 in the previous insn | |
6037 | that computed their value. Then REG1 will become a dead store | |
6038 | and won't cloud the situation for later optimizations. | |
7afe21cc RK |
6039 | |
6040 | Do not make this change if REG1 is a hard register, because it will | |
6041 | then be used in the sequel and we may be changing a two-operand insn | |
6042 | into a three-operand insn. | |
6043 | ||
4a8cae83 | 6044 | Also do not do this if we are operating on a copy of INSN. */ |
7afe21cc | 6045 | |
7b02f4e0 SB |
6046 | if (n_sets == 1 && sets[0].rtl) |
6047 | try_back_substitute_reg (sets[0].rtl, insn); | |
7afe21cc | 6048 | |
932ad4d9 | 6049 | done:; |
7afe21cc RK |
6050 | } |
6051 | \f | |
a4c6502a | 6052 | /* Remove from the hash table all expressions that reference memory. */ |
14a774a9 | 6053 | |
7afe21cc | 6054 | static void |
7080f735 | 6055 | invalidate_memory (void) |
7afe21cc | 6056 | { |
b3694847 SS |
6057 | int i; |
6058 | struct table_elt *p, *next; | |
7afe21cc | 6059 | |
9b1549b8 | 6060 | for (i = 0; i < HASH_SIZE; i++) |
9ae8ffe7 JL |
6061 | for (p = table[i]; p; p = next) |
6062 | { | |
6063 | next = p->next_same_hash; | |
6064 | if (p->in_memory) | |
6065 | remove_from_table (p, i); | |
6066 | } | |
6067 | } | |
6068 | ||
7b02f4e0 | 6069 | /* Perform invalidation on the basis of everything about INSN, |
7afe21cc RK |
6070 | except for invalidating the actual places that are SET in it. |
6071 | This includes the places CLOBBERed, and anything that might | |
7b02f4e0 | 6072 | alias with something that is SET or CLOBBERed. */ |
7afe21cc RK |
6073 | |
6074 | static void | |
20468884 | 6075 | invalidate_from_clobbers (rtx_insn *insn) |
7afe21cc | 6076 | { |
7b02f4e0 SB |
6077 | rtx x = PATTERN (insn); |
6078 | ||
7afe21cc RK |
6079 | if (GET_CODE (x) == CLOBBER) |
6080 | { | |
6081 | rtx ref = XEXP (x, 0); | |
9ae8ffe7 JL |
6082 | if (ref) |
6083 | { | |
f8cfc6aa | 6084 | if (REG_P (ref) || GET_CODE (ref) == SUBREG |
3c0cb5de | 6085 | || MEM_P (ref)) |
9ae8ffe7 JL |
6086 | invalidate (ref, VOIDmode); |
6087 | else if (GET_CODE (ref) == STRICT_LOW_PART | |
6088 | || GET_CODE (ref) == ZERO_EXTRACT) | |
6089 | invalidate (XEXP (ref, 0), GET_MODE (ref)); | |
6090 | } | |
7afe21cc RK |
6091 | } |
6092 | else if (GET_CODE (x) == PARALLEL) | |
6093 | { | |
b3694847 | 6094 | int i; |
7afe21cc RK |
6095 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) |
6096 | { | |
b3694847 | 6097 | rtx y = XVECEXP (x, 0, i); |
7afe21cc RK |
6098 | if (GET_CODE (y) == CLOBBER) |
6099 | { | |
6100 | rtx ref = XEXP (y, 0); | |
f8cfc6aa | 6101 | if (REG_P (ref) || GET_CODE (ref) == SUBREG |
3c0cb5de | 6102 | || MEM_P (ref)) |
9ae8ffe7 JL |
6103 | invalidate (ref, VOIDmode); |
6104 | else if (GET_CODE (ref) == STRICT_LOW_PART | |
6105 | || GET_CODE (ref) == ZERO_EXTRACT) | |
6106 | invalidate (XEXP (ref, 0), GET_MODE (ref)); | |
7afe21cc RK |
6107 | } |
6108 | } | |
6109 | } | |
6110 | } | |
6111 | \f | |
7b02f4e0 SB |
6112 | /* Perform invalidation on the basis of everything about INSN. |
6113 | This includes the places CLOBBERed, and anything that might | |
6114 | alias with something that is SET or CLOBBERed. */ | |
6115 | ||
6116 | static void | |
20468884 | 6117 | invalidate_from_sets_and_clobbers (rtx_insn *insn) |
7b02f4e0 SB |
6118 | { |
6119 | rtx tem; | |
6120 | rtx x = PATTERN (insn); | |
6121 | ||
6122 | if (CALL_P (insn)) | |
6123 | { | |
6124 | for (tem = CALL_INSN_FUNCTION_USAGE (insn); tem; tem = XEXP (tem, 1)) | |
6125 | if (GET_CODE (XEXP (tem, 0)) == CLOBBER) | |
6126 | invalidate (SET_DEST (XEXP (tem, 0)), VOIDmode); | |
6127 | } | |
6128 | ||
6129 | /* Ensure we invalidate the destination register of a CALL insn. | |
6130 | This is necessary for machines where this register is a fixed_reg, | |
6131 | because no other code would invalidate it. */ | |
6132 | if (GET_CODE (x) == SET && GET_CODE (SET_SRC (x)) == CALL) | |
6133 | invalidate (SET_DEST (x), VOIDmode); | |
6134 | ||
6135 | else if (GET_CODE (x) == PARALLEL) | |
6136 | { | |
6137 | int i; | |
6138 | ||
6139 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
6140 | { | |
6141 | rtx y = XVECEXP (x, 0, i); | |
6142 | if (GET_CODE (y) == CLOBBER) | |
6143 | { | |
6144 | rtx clobbered = XEXP (y, 0); | |
6145 | ||
6146 | if (REG_P (clobbered) | |
6147 | || GET_CODE (clobbered) == SUBREG) | |
6148 | invalidate (clobbered, VOIDmode); | |
6149 | else if (GET_CODE (clobbered) == STRICT_LOW_PART | |
6150 | || GET_CODE (clobbered) == ZERO_EXTRACT) | |
6151 | invalidate (XEXP (clobbered, 0), GET_MODE (clobbered)); | |
6152 | } | |
6153 | else if (GET_CODE (y) == SET && GET_CODE (SET_SRC (y)) == CALL) | |
6154 | invalidate (SET_DEST (y), VOIDmode); | |
6155 | } | |
6156 | } | |
6157 | } | |
6158 | \f | |
7afe21cc RK |
6159 | /* Process X, part of the REG_NOTES of an insn. Look at any REG_EQUAL notes |
6160 | and replace any registers in them with either an equivalent constant | |
6161 | or the canonical form of the register. If we are inside an address, | |
6162 | only do this if the address remains valid. | |
6163 | ||
6164 | OBJECT is 0 except when within a MEM in which case it is the MEM. | |
6165 | ||
6166 | Return the replacement for X. */ | |
6167 | ||
6168 | static rtx | |
6fb5fa3c | 6169 | cse_process_notes_1 (rtx x, rtx object, bool *changed) |
7afe21cc RK |
6170 | { |
6171 | enum rtx_code code = GET_CODE (x); | |
6f7d635c | 6172 | const char *fmt = GET_RTX_FORMAT (code); |
7afe21cc RK |
6173 | int i; |
6174 | ||
6175 | switch (code) | |
6176 | { | |
7afe21cc RK |
6177 | case CONST: |
6178 | case SYMBOL_REF: | |
6179 | case LABEL_REF: | |
d8116890 | 6180 | CASE_CONST_ANY: |
7afe21cc RK |
6181 | case PC: |
6182 | case CC0: | |
6183 | case LO_SUM: | |
6184 | return x; | |
6185 | ||
6186 | case MEM: | |
c96208fa | 6187 | validate_change (x, &XEXP (x, 0), |
6fb5fa3c | 6188 | cse_process_notes (XEXP (x, 0), x, changed), 0); |
7afe21cc RK |
6189 | return x; |
6190 | ||
6191 | case EXPR_LIST: | |
7afe21cc | 6192 | if (REG_NOTE_KIND (x) == REG_EQUAL) |
6fb5fa3c | 6193 | XEXP (x, 0) = cse_process_notes (XEXP (x, 0), NULL_RTX, changed); |
e5af9ddd RS |
6194 | /* Fall through. */ |
6195 | ||
6196 | case INSN_LIST: | |
6197 | case INT_LIST: | |
7afe21cc | 6198 | if (XEXP (x, 1)) |
6fb5fa3c | 6199 | XEXP (x, 1) = cse_process_notes (XEXP (x, 1), NULL_RTX, changed); |
7afe21cc RK |
6200 | return x; |
6201 | ||
e4890d45 RS |
6202 | case SIGN_EXTEND: |
6203 | case ZERO_EXTEND: | |
0b0ee36c | 6204 | case SUBREG: |
e4890d45 | 6205 | { |
32e9fa48 | 6206 | rtx new_rtx = cse_process_notes (XEXP (x, 0), object, changed); |
e4890d45 RS |
6207 | /* We don't substitute VOIDmode constants into these rtx, |
6208 | since they would impede folding. */ | |
32e9fa48 KG |
6209 | if (GET_MODE (new_rtx) != VOIDmode) |
6210 | validate_change (object, &XEXP (x, 0), new_rtx, 0); | |
e4890d45 RS |
6211 | return x; |
6212 | } | |
6213 | ||
dfebbdc6 JJ |
6214 | case UNSIGNED_FLOAT: |
6215 | { | |
6216 | rtx new_rtx = cse_process_notes (XEXP (x, 0), object, changed); | |
6217 | /* We don't substitute negative VOIDmode constants into these rtx, | |
6218 | since they would impede folding. */ | |
6219 | if (GET_MODE (new_rtx) != VOIDmode | |
6220 | || (CONST_INT_P (new_rtx) && INTVAL (new_rtx) >= 0) | |
6221 | || (CONST_DOUBLE_P (new_rtx) && CONST_DOUBLE_HIGH (new_rtx) >= 0)) | |
6222 | validate_change (object, &XEXP (x, 0), new_rtx, 0); | |
6223 | return x; | |
6224 | } | |
6225 | ||
7afe21cc | 6226 | case REG: |
30f72379 | 6227 | i = REG_QTY (REGNO (x)); |
7afe21cc RK |
6228 | |
6229 | /* Return a constant or a constant register. */ | |
1bb98cec | 6230 | if (REGNO_QTY_VALID_P (REGNO (x))) |
7afe21cc | 6231 | { |
1bb98cec DM |
6232 | struct qty_table_elem *ent = &qty_table[i]; |
6233 | ||
6234 | if (ent->const_rtx != NULL_RTX | |
6235 | && (CONSTANT_P (ent->const_rtx) | |
f8cfc6aa | 6236 | || REG_P (ent->const_rtx))) |
1bb98cec | 6237 | { |
32e9fa48 KG |
6238 | rtx new_rtx = gen_lowpart (GET_MODE (x), ent->const_rtx); |
6239 | if (new_rtx) | |
6240 | return copy_rtx (new_rtx); | |
1bb98cec | 6241 | } |
7afe21cc RK |
6242 | } |
6243 | ||
6244 | /* Otherwise, canonicalize this register. */ | |
20468884 | 6245 | return canon_reg (x, NULL); |
278a83b2 | 6246 | |
e9a25f70 JL |
6247 | default: |
6248 | break; | |
7afe21cc RK |
6249 | } |
6250 | ||
6251 | for (i = 0; i < GET_RTX_LENGTH (code); i++) | |
6252 | if (fmt[i] == 'e') | |
6253 | validate_change (object, &XEXP (x, i), | |
6fb5fa3c | 6254 | cse_process_notes (XEXP (x, i), object, changed), 0); |
7afe21cc RK |
6255 | |
6256 | return x; | |
6257 | } | |
6fb5fa3c DB |
6258 | |
6259 | static rtx | |
6260 | cse_process_notes (rtx x, rtx object, bool *changed) | |
6261 | { | |
32e9fa48 KG |
6262 | rtx new_rtx = cse_process_notes_1 (x, object, changed); |
6263 | if (new_rtx != x) | |
6fb5fa3c | 6264 | *changed = true; |
32e9fa48 | 6265 | return new_rtx; |
6fb5fa3c DB |
6266 | } |
6267 | ||
7afe21cc | 6268 | \f |
932ad4d9 | 6269 | /* Find a path in the CFG, starting with FIRST_BB to perform CSE on. |
7afe21cc | 6270 | |
932ad4d9 SB |
6271 | DATA is a pointer to a struct cse_basic_block_data, that is used to |
6272 | describe the path. | |
6273 | It is filled with a queue of basic blocks, starting with FIRST_BB | |
6274 | and following a trace through the CFG. | |
b8698a0f | 6275 | |
932ad4d9 SB |
6276 | If all paths starting at FIRST_BB have been followed, or no new path |
6277 | starting at FIRST_BB can be constructed, this function returns FALSE. | |
6278 | Otherwise, DATA->path is filled and the function returns TRUE indicating | |
6279 | that a path to follow was found. | |
7afe21cc | 6280 | |
2e226e66 | 6281 | If FOLLOW_JUMPS is false, the maximum path length is 1 and the only |
932ad4d9 | 6282 | block in the path will be FIRST_BB. */ |
7afe21cc | 6283 | |
932ad4d9 SB |
6284 | static bool |
6285 | cse_find_path (basic_block first_bb, struct cse_basic_block_data *data, | |
6286 | int follow_jumps) | |
7afe21cc | 6287 | { |
932ad4d9 SB |
6288 | basic_block bb; |
6289 | edge e; | |
6290 | int path_size; | |
b8698a0f | 6291 | |
d7c028c0 | 6292 | bitmap_set_bit (cse_visited_basic_blocks, first_bb->index); |
7afe21cc | 6293 | |
932ad4d9 SB |
6294 | /* See if there is a previous path. */ |
6295 | path_size = data->path_size; | |
6296 | ||
6297 | /* There is a previous path. Make sure it started with FIRST_BB. */ | |
6298 | if (path_size) | |
6299 | gcc_assert (data->path[0].bb == first_bb); | |
6300 | ||
6301 | /* There was only one basic block in the last path. Clear the path and | |
6302 | return, so that paths starting at another basic block can be tried. */ | |
6303 | if (path_size == 1) | |
6304 | { | |
6305 | path_size = 0; | |
6306 | goto done; | |
6307 | } | |
6308 | ||
6309 | /* If the path was empty from the beginning, construct a new path. */ | |
6310 | if (path_size == 0) | |
6311 | data->path[path_size++].bb = first_bb; | |
6312 | else | |
7afe21cc | 6313 | { |
932ad4d9 SB |
6314 | /* Otherwise, path_size must be equal to or greater than 2, because |
6315 | a previous path exists that is at least two basic blocks long. | |
6316 | ||
6317 | Update the previous branch path, if any. If the last branch was | |
6318 | previously along the branch edge, take the fallthrough edge now. */ | |
6319 | while (path_size >= 2) | |
7afe21cc | 6320 | { |
932ad4d9 SB |
6321 | basic_block last_bb_in_path, previous_bb_in_path; |
6322 | edge e; | |
6323 | ||
6324 | --path_size; | |
6325 | last_bb_in_path = data->path[path_size].bb; | |
6326 | previous_bb_in_path = data->path[path_size - 1].bb; | |
6327 | ||
6328 | /* If we previously followed a path along the branch edge, try | |
6329 | the fallthru edge now. */ | |
6330 | if (EDGE_COUNT (previous_bb_in_path->succs) == 2 | |
6331 | && any_condjump_p (BB_END (previous_bb_in_path)) | |
6332 | && (e = find_edge (previous_bb_in_path, last_bb_in_path)) | |
6333 | && e == BRANCH_EDGE (previous_bb_in_path)) | |
6334 | { | |
6335 | bb = FALLTHRU_EDGE (previous_bb_in_path)->dest; | |
fefa31b5 | 6336 | if (bb != EXIT_BLOCK_PTR_FOR_FN (cfun) |
481e0a49 AO |
6337 | && single_pred_p (bb) |
6338 | /* We used to assert here that we would only see blocks | |
6339 | that we have not visited yet. But we may end up | |
6340 | visiting basic blocks twice if the CFG has changed | |
6341 | in this run of cse_main, because when the CFG changes | |
6342 | the topological sort of the CFG also changes. A basic | |
6343 | blocks that previously had more than two predecessors | |
6344 | may now have a single predecessor, and become part of | |
6345 | a path that starts at another basic block. | |
6346 | ||
6347 | We still want to visit each basic block only once, so | |
6348 | halt the path here if we have already visited BB. */ | |
d7c028c0 | 6349 | && !bitmap_bit_p (cse_visited_basic_blocks, bb->index)) |
932ad4d9 | 6350 | { |
d7c028c0 | 6351 | bitmap_set_bit (cse_visited_basic_blocks, bb->index); |
932ad4d9 SB |
6352 | data->path[path_size++].bb = bb; |
6353 | break; | |
6354 | } | |
6355 | } | |
6356 | ||
6357 | data->path[path_size].bb = NULL; | |
6358 | } | |
6359 | ||
6360 | /* If only one block remains in the path, bail. */ | |
6361 | if (path_size == 1) | |
6362 | { | |
6363 | path_size = 0; | |
6364 | goto done; | |
7afe21cc | 6365 | } |
7afe21cc RK |
6366 | } |
6367 | ||
932ad4d9 SB |
6368 | /* Extend the path if possible. */ |
6369 | if (follow_jumps) | |
7afe21cc | 6370 | { |
932ad4d9 SB |
6371 | bb = data->path[path_size - 1].bb; |
6372 | while (bb && path_size < PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH)) | |
6373 | { | |
6374 | if (single_succ_p (bb)) | |
6375 | e = single_succ_edge (bb); | |
6376 | else if (EDGE_COUNT (bb->succs) == 2 | |
6377 | && any_condjump_p (BB_END (bb))) | |
6378 | { | |
6379 | /* First try to follow the branch. If that doesn't lead | |
6380 | to a useful path, follow the fallthru edge. */ | |
6381 | e = BRANCH_EDGE (bb); | |
6382 | if (!single_pred_p (e->dest)) | |
6383 | e = FALLTHRU_EDGE (bb); | |
6384 | } | |
6385 | else | |
6386 | e = NULL; | |
7afe21cc | 6387 | |
bc6d3f91 | 6388 | if (e |
76015c34 | 6389 | && !((e->flags & EDGE_ABNORMAL_CALL) && cfun->has_nonlocal_label) |
fefa31b5 | 6390 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
481e0a49 AO |
6391 | && single_pred_p (e->dest) |
6392 | /* Avoid visiting basic blocks twice. The large comment | |
6393 | above explains why this can happen. */ | |
d7c028c0 | 6394 | && !bitmap_bit_p (cse_visited_basic_blocks, e->dest->index)) |
932ad4d9 SB |
6395 | { |
6396 | basic_block bb2 = e->dest; | |
d7c028c0 | 6397 | bitmap_set_bit (cse_visited_basic_blocks, bb2->index); |
932ad4d9 SB |
6398 | data->path[path_size++].bb = bb2; |
6399 | bb = bb2; | |
6400 | } | |
6401 | else | |
6402 | bb = NULL; | |
6403 | } | |
6404 | } | |
6405 | ||
6406 | done: | |
6407 | data->path_size = path_size; | |
6408 | return path_size != 0; | |
6409 | } | |
6410 | \f | |
6411 | /* Dump the path in DATA to file F. NSETS is the number of sets | |
6412 | in the path. */ | |
6413 | ||
6414 | static void | |
6415 | cse_dump_path (struct cse_basic_block_data *data, int nsets, FILE *f) | |
6416 | { | |
6417 | int path_entry; | |
6418 | ||
6419 | fprintf (f, ";; Following path with %d sets: ", nsets); | |
6420 | for (path_entry = 0; path_entry < data->path_size; path_entry++) | |
6421 | fprintf (f, "%d ", (data->path[path_entry].bb)->index); | |
6422 | fputc ('\n', dump_file); | |
6423 | fflush (f); | |
6424 | } | |
6425 | ||
a7582f7c SB |
6426 | \f |
6427 | /* Return true if BB has exception handling successor edges. */ | |
6428 | ||
6429 | static bool | |
6430 | have_eh_succ_edges (basic_block bb) | |
6431 | { | |
6432 | edge e; | |
6433 | edge_iterator ei; | |
6434 | ||
6435 | FOR_EACH_EDGE (e, ei, bb->succs) | |
6436 | if (e->flags & EDGE_EH) | |
6437 | return true; | |
6438 | ||
6439 | return false; | |
6440 | } | |
6441 | ||
932ad4d9 SB |
6442 | \f |
6443 | /* Scan to the end of the path described by DATA. Return an estimate of | |
6fb5fa3c | 6444 | the total number of SETs of all insns in the path. */ |
932ad4d9 SB |
6445 | |
6446 | static void | |
6447 | cse_prescan_path (struct cse_basic_block_data *data) | |
6448 | { | |
6449 | int nsets = 0; | |
932ad4d9 SB |
6450 | int path_size = data->path_size; |
6451 | int path_entry; | |
6452 | ||
6453 | /* Scan to end of each basic block in the path. */ | |
b8698a0f | 6454 | for (path_entry = 0; path_entry < path_size; path_entry++) |
932ad4d9 SB |
6455 | { |
6456 | basic_block bb; | |
20468884 | 6457 | rtx_insn *insn; |
164c8956 | 6458 | |
932ad4d9 | 6459 | bb = data->path[path_entry].bb; |
7afe21cc | 6460 | |
932ad4d9 | 6461 | FOR_BB_INSNS (bb, insn) |
7afe21cc | 6462 | { |
932ad4d9 SB |
6463 | if (!INSN_P (insn)) |
6464 | continue; | |
278a83b2 | 6465 | |
932ad4d9 SB |
6466 | /* A PARALLEL can have lots of SETs in it, |
6467 | especially if it is really an ASM_OPERANDS. */ | |
6468 | if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
6469 | nsets += XVECLEN (PATTERN (insn), 0); | |
6470 | else | |
6471 | nsets += 1; | |
7afe21cc | 6472 | } |
932ad4d9 SB |
6473 | } |
6474 | ||
932ad4d9 SB |
6475 | data->nsets = nsets; |
6476 | } | |
6477 | \f | |
f0002948 RS |
6478 | /* Return true if the pattern of INSN uses a LABEL_REF for which |
6479 | there isn't a REG_LABEL_OPERAND note. */ | |
6480 | ||
6481 | static bool | |
6482 | check_for_label_ref (rtx_insn *insn) | |
6483 | { | |
6484 | /* If this insn uses a LABEL_REF and there isn't a REG_LABEL_OPERAND | |
6485 | note for it, we must rerun jump since it needs to place the note. If | |
6486 | this is a LABEL_REF for a CODE_LABEL that isn't in the insn chain, | |
6487 | don't do this since no REG_LABEL_OPERAND will be added. */ | |
6488 | subrtx_iterator::array_type array; | |
6489 | FOR_EACH_SUBRTX (iter, array, PATTERN (insn), ALL) | |
6490 | { | |
6491 | const_rtx x = *iter; | |
6492 | if (GET_CODE (x) == LABEL_REF | |
6493 | && !LABEL_REF_NONLOCAL_P (x) | |
6494 | && (!JUMP_P (insn) | |
04a121a7 TS |
6495 | || !label_is_jump_target_p (label_ref_label (x), insn)) |
6496 | && LABEL_P (label_ref_label (x)) | |
6497 | && INSN_UID (label_ref_label (x)) != 0 | |
6498 | && !find_reg_note (insn, REG_LABEL_OPERAND, label_ref_label (x))) | |
f0002948 RS |
6499 | return true; |
6500 | } | |
6501 | return false; | |
6502 | } | |
6503 | ||
932ad4d9 | 6504 | /* Process a single extended basic block described by EBB_DATA. */ |
7afe21cc | 6505 | |
932ad4d9 SB |
6506 | static void |
6507 | cse_extended_basic_block (struct cse_basic_block_data *ebb_data) | |
6508 | { | |
6509 | int path_size = ebb_data->path_size; | |
6510 | int path_entry; | |
6511 | int num_insns = 0; | |
6512 | ||
6513 | /* Allocate the space needed by qty_table. */ | |
6514 | qty_table = XNEWVEC (struct qty_table_elem, max_qty); | |
6515 | ||
6516 | new_basic_block (); | |
89a95777 KZ |
6517 | cse_ebb_live_in = df_get_live_in (ebb_data->path[0].bb); |
6518 | cse_ebb_live_out = df_get_live_out (ebb_data->path[path_size - 1].bb); | |
932ad4d9 SB |
6519 | for (path_entry = 0; path_entry < path_size; path_entry++) |
6520 | { | |
6521 | basic_block bb; | |
20468884 | 6522 | rtx_insn *insn; |
932ad4d9 SB |
6523 | |
6524 | bb = ebb_data->path[path_entry].bb; | |
e186ff69 AK |
6525 | |
6526 | /* Invalidate recorded information for eh regs if there is an EH | |
6527 | edge pointing to that bb. */ | |
6528 | if (bb_has_eh_pred (bb)) | |
6529 | { | |
292321a5 | 6530 | df_ref def; |
e186ff69 | 6531 | |
292321a5 RS |
6532 | FOR_EACH_ARTIFICIAL_DEF (def, bb->index) |
6533 | if (DF_REF_FLAGS (def) & DF_REF_AT_TOP) | |
6534 | invalidate (DF_REF_REG (def), GET_MODE (DF_REF_REG (def))); | |
e186ff69 AK |
6535 | } |
6536 | ||
9fcb01de | 6537 | optimize_this_for_speed_p = optimize_bb_for_speed_p (bb); |
ba4807a0 | 6538 | FOR_BB_INSNS (bb, insn) |
7afe21cc | 6539 | { |
932ad4d9 SB |
6540 | /* If we have processed 1,000 insns, flush the hash table to |
6541 | avoid extreme quadratic behavior. We must not include NOTEs | |
6542 | in the count since there may be more of them when generating | |
6543 | debugging information. If we clear the table at different | |
6544 | times, code generated with -g -O might be different than code | |
6545 | generated with -O but not -g. | |
6546 | ||
6547 | FIXME: This is a real kludge and needs to be done some other | |
6548 | way. */ | |
b5b8b0ac | 6549 | if (NONDEBUG_INSN_P (insn) |
932ad4d9 SB |
6550 | && num_insns++ > PARAM_VALUE (PARAM_MAX_CSE_INSNS)) |
6551 | { | |
6552 | flush_hash_table (); | |
6553 | num_insns = 0; | |
6554 | } | |
7afe21cc | 6555 | |
932ad4d9 | 6556 | if (INSN_P (insn)) |
7afe21cc | 6557 | { |
932ad4d9 SB |
6558 | /* Process notes first so we have all notes in canonical forms |
6559 | when looking for duplicate operations. */ | |
6560 | if (REG_NOTES (insn)) | |
6fb5fa3c DB |
6561 | { |
6562 | bool changed = false; | |
6563 | REG_NOTES (insn) = cse_process_notes (REG_NOTES (insn), | |
6564 | NULL_RTX, &changed); | |
6565 | if (changed) | |
6566 | df_notes_rescan (insn); | |
6567 | } | |
932ad4d9 | 6568 | |
4a8cae83 | 6569 | cse_insn (insn); |
932ad4d9 | 6570 | |
932ad4d9 SB |
6571 | /* If we haven't already found an insn where we added a LABEL_REF, |
6572 | check this one. */ | |
2aac3a01 | 6573 | if (INSN_P (insn) && !recorded_label_ref |
f0002948 | 6574 | && check_for_label_ref (insn)) |
2aac3a01 | 6575 | recorded_label_ref = true; |
96fb470d | 6576 | |
058eb3b0 | 6577 | if (HAVE_cc0 && NONDEBUG_INSN_P (insn)) |
96fb470d | 6578 | { |
5f262d13 AO |
6579 | /* If the previous insn sets CC0 and this insn no |
6580 | longer references CC0, delete the previous insn. | |
6581 | Here we use fact that nothing expects CC0 to be | |
6582 | valid over an insn, which is true until the final | |
6583 | pass. */ | |
20468884 DM |
6584 | rtx_insn *prev_insn; |
6585 | rtx tem; | |
5f262d13 AO |
6586 | |
6587 | prev_insn = prev_nonnote_nondebug_insn (insn); | |
6588 | if (prev_insn && NONJUMP_INSN_P (prev_insn) | |
6589 | && (tem = single_set (prev_insn)) != NULL_RTX | |
6590 | && SET_DEST (tem) == cc0_rtx | |
6591 | && ! reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
6592 | delete_insn (prev_insn); | |
6593 | ||
6594 | /* If this insn is not the last insn in the basic | |
6595 | block, it will be PREV_INSN(insn) in the next | |
6596 | iteration. If we recorded any CC0-related | |
6597 | information for this insn, remember it. */ | |
6598 | if (insn != BB_END (bb)) | |
6599 | { | |
6600 | prev_insn_cc0 = this_insn_cc0; | |
6601 | prev_insn_cc0_mode = this_insn_cc0_mode; | |
6602 | } | |
96fb470d | 6603 | } |
932ad4d9 SB |
6604 | } |
6605 | } | |
7afe21cc | 6606 | |
a7582f7c SB |
6607 | /* With non-call exceptions, we are not always able to update |
6608 | the CFG properly inside cse_insn. So clean up possibly | |
6609 | redundant EH edges here. */ | |
8f4f502f | 6610 | if (cfun->can_throw_non_call_exceptions && have_eh_succ_edges (bb)) |
2aac3a01 | 6611 | cse_cfg_altered |= purge_dead_edges (bb); |
a7582f7c | 6612 | |
932ad4d9 SB |
6613 | /* If we changed a conditional jump, we may have terminated |
6614 | the path we are following. Check that by verifying that | |
6615 | the edge we would take still exists. If the edge does | |
6616 | not exist anymore, purge the remainder of the path. | |
6617 | Note that this will cause us to return to the caller. */ | |
6618 | if (path_entry < path_size - 1) | |
6619 | { | |
6620 | basic_block next_bb = ebb_data->path[path_entry + 1].bb; | |
6621 | if (!find_edge (bb, next_bb)) | |
27511c65 SB |
6622 | { |
6623 | do | |
6624 | { | |
6625 | path_size--; | |
6626 | ||
6627 | /* If we truncate the path, we must also reset the | |
6628 | visited bit on the remaining blocks in the path, | |
6629 | or we will never visit them at all. */ | |
d7c028c0 | 6630 | bitmap_clear_bit (cse_visited_basic_blocks, |
27511c65 SB |
6631 | ebb_data->path[path_size].bb->index); |
6632 | ebb_data->path[path_size].bb = NULL; | |
6633 | } | |
6634 | while (path_size - 1 != path_entry); | |
6635 | ebb_data->path_size = path_size; | |
6636 | } | |
7afe21cc | 6637 | } |
7afe21cc | 6638 | |
932ad4d9 SB |
6639 | /* If this is a conditional jump insn, record any known |
6640 | equivalences due to the condition being tested. */ | |
6641 | insn = BB_END (bb); | |
6642 | if (path_entry < path_size - 1 | |
6643 | && JUMP_P (insn) | |
6644 | && single_set (insn) | |
6645 | && any_condjump_p (insn)) | |
6646 | { | |
6647 | basic_block next_bb = ebb_data->path[path_entry + 1].bb; | |
6648 | bool taken = (next_bb == BRANCH_EDGE (bb)->dest); | |
6649 | record_jump_equiv (insn, taken); | |
6650 | } | |
96fb470d | 6651 | |
96fb470d SB |
6652 | /* Clear the CC0-tracking related insns, they can't provide |
6653 | useful information across basic block boundaries. */ | |
6654 | prev_insn_cc0 = 0; | |
932ad4d9 | 6655 | } |
7afe21cc | 6656 | |
932ad4d9 | 6657 | gcc_assert (next_qty <= max_qty); |
7afe21cc | 6658 | |
932ad4d9 | 6659 | free (qty_table); |
7afe21cc | 6660 | } |
6fb5fa3c | 6661 | |
7afe21cc | 6662 | \f |
7afe21cc RK |
6663 | /* Perform cse on the instructions of a function. |
6664 | F is the first instruction. | |
6665 | NREGS is one plus the highest pseudo-reg number used in the instruction. | |
6666 | ||
2aac3a01 EB |
6667 | Return 2 if jump optimizations should be redone due to simplifications |
6668 | in conditional jump instructions. | |
6669 | Return 1 if the CFG should be cleaned up because it has been modified. | |
6670 | Return 0 otherwise. */ | |
7afe21cc | 6671 | |
711417cd | 6672 | static int |
20468884 | 6673 | cse_main (rtx_insn *f ATTRIBUTE_UNUSED, int nregs) |
7afe21cc | 6674 | { |
932ad4d9 SB |
6675 | struct cse_basic_block_data ebb_data; |
6676 | basic_block bb; | |
8b1c6fd7 | 6677 | int *rc_order = XNEWVEC (int, last_basic_block_for_fn (cfun)); |
932ad4d9 | 6678 | int i, n_blocks; |
7afe21cc | 6679 | |
afb72432 IE |
6680 | /* CSE doesn't use dominane info but can invalidate it in different ways. |
6681 | For simplicity free dominance info here. */ | |
6682 | free_dominance_info (CDI_DOMINATORS); | |
6683 | ||
6fb5fa3c | 6684 | df_set_flags (DF_LR_RUN_DCE); |
dca3da7a | 6685 | df_note_add_problem (); |
6fb5fa3c DB |
6686 | df_analyze (); |
6687 | df_set_flags (DF_DEFER_INSN_RESCAN); | |
6688 | ||
6689 | reg_scan (get_insns (), max_reg_num ()); | |
bc5e3b54 KH |
6690 | init_cse_reg_info (nregs); |
6691 | ||
932ad4d9 SB |
6692 | ebb_data.path = XNEWVEC (struct branch_path, |
6693 | PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH)); | |
9bf8cfbf | 6694 | |
2aac3a01 EB |
6695 | cse_cfg_altered = false; |
6696 | cse_jumps_altered = false; | |
6697 | recorded_label_ref = false; | |
7afe21cc | 6698 | constant_pool_entries_cost = 0; |
dd0ba281 | 6699 | constant_pool_entries_regcost = 0; |
932ad4d9 SB |
6700 | ebb_data.path_size = 0; |
6701 | ebb_data.nsets = 0; | |
2f93eea8 | 6702 | rtl_hooks = cse_rtl_hooks; |
7afe21cc RK |
6703 | |
6704 | init_recog (); | |
9ae8ffe7 | 6705 | init_alias_analysis (); |
7afe21cc | 6706 | |
5ed6ace5 | 6707 | reg_eqv_table = XNEWVEC (struct reg_eqv_elem, nregs); |
7afe21cc | 6708 | |
932ad4d9 | 6709 | /* Set up the table of already visited basic blocks. */ |
8b1c6fd7 | 6710 | cse_visited_basic_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
f61e445a | 6711 | bitmap_clear (cse_visited_basic_blocks); |
7afe21cc | 6712 | |
a7582f7c | 6713 | /* Loop over basic blocks in reverse completion order (RPO), |
932ad4d9 | 6714 | excluding the ENTRY and EXIT blocks. */ |
27511c65 | 6715 | n_blocks = pre_and_rev_post_order_compute (NULL, rc_order, false); |
932ad4d9 SB |
6716 | i = 0; |
6717 | while (i < n_blocks) | |
7afe21cc | 6718 | { |
a7582f7c | 6719 | /* Find the first block in the RPO queue that we have not yet |
932ad4d9 SB |
6720 | processed before. */ |
6721 | do | |
e9a25f70 | 6722 | { |
06e28de2 | 6723 | bb = BASIC_BLOCK_FOR_FN (cfun, rc_order[i++]); |
e9a25f70 | 6724 | } |
d7c028c0 | 6725 | while (bitmap_bit_p (cse_visited_basic_blocks, bb->index) |
932ad4d9 | 6726 | && i < n_blocks); |
7afe21cc | 6727 | |
932ad4d9 SB |
6728 | /* Find all paths starting with BB, and process them. */ |
6729 | while (cse_find_path (bb, &ebb_data, flag_cse_follow_jumps)) | |
7afe21cc | 6730 | { |
932ad4d9 SB |
6731 | /* Pre-scan the path. */ |
6732 | cse_prescan_path (&ebb_data); | |
7afe21cc | 6733 | |
932ad4d9 SB |
6734 | /* If this basic block has no sets, skip it. */ |
6735 | if (ebb_data.nsets == 0) | |
6736 | continue; | |
7afe21cc | 6737 | |
2e226e66 | 6738 | /* Get a reasonable estimate for the maximum number of qty's |
932ad4d9 SB |
6739 | needed for this path. For this, we take the number of sets |
6740 | and multiply that by MAX_RECOG_OPERANDS. */ | |
6741 | max_qty = ebb_data.nsets * MAX_RECOG_OPERANDS; | |
7afe21cc | 6742 | |
932ad4d9 SB |
6743 | /* Dump the path we're about to process. */ |
6744 | if (dump_file) | |
6745 | cse_dump_path (&ebb_data, ebb_data.nsets, dump_file); | |
6a5293dc | 6746 | |
932ad4d9 | 6747 | cse_extended_basic_block (&ebb_data); |
7afe21cc | 6748 | } |
7afe21cc RK |
6749 | } |
6750 | ||
932ad4d9 SB |
6751 | /* Clean up. */ |
6752 | end_alias_analysis (); | |
932ad4d9 SB |
6753 | free (reg_eqv_table); |
6754 | free (ebb_data.path); | |
6755 | sbitmap_free (cse_visited_basic_blocks); | |
27511c65 | 6756 | free (rc_order); |
932ad4d9 | 6757 | rtl_hooks = general_rtl_hooks; |
75c6bd46 | 6758 | |
2aac3a01 EB |
6759 | if (cse_jumps_altered || recorded_label_ref) |
6760 | return 2; | |
6761 | else if (cse_cfg_altered) | |
6762 | return 1; | |
6763 | else | |
6764 | return 0; | |
7afe21cc RK |
6765 | } |
6766 | \f | |
6767 | /* Count the number of times registers are used (not set) in X. | |
6768 | COUNTS is an array in which we accumulate the count, INCR is how much | |
b92ba6ff R |
6769 | we count each register usage. |
6770 | ||
6771 | Don't count a usage of DEST, which is the SET_DEST of a SET which | |
6772 | contains X in its SET_SRC. This is because such a SET does not | |
6773 | modify the liveness of DEST. | |
34161e98 RS |
6774 | DEST is set to pc_rtx for a trapping insn, or for an insn with side effects. |
6775 | We must then count uses of a SET_DEST regardless, because the insn can't be | |
6776 | deleted here. */ | |
7afe21cc RK |
6777 | |
6778 | static void | |
b92ba6ff | 6779 | count_reg_usage (rtx x, int *counts, rtx dest, int incr) |
7afe21cc | 6780 | { |
f1e7c95f | 6781 | enum rtx_code code; |
b17d5d7c | 6782 | rtx note; |
6f7d635c | 6783 | const char *fmt; |
7afe21cc RK |
6784 | int i, j; |
6785 | ||
f1e7c95f RK |
6786 | if (x == 0) |
6787 | return; | |
6788 | ||
6789 | switch (code = GET_CODE (x)) | |
7afe21cc RK |
6790 | { |
6791 | case REG: | |
b92ba6ff R |
6792 | if (x != dest) |
6793 | counts[REGNO (x)] += incr; | |
7afe21cc RK |
6794 | return; |
6795 | ||
6796 | case PC: | |
6797 | case CC0: | |
6798 | case CONST: | |
d8116890 | 6799 | CASE_CONST_ANY: |
7afe21cc RK |
6800 | case SYMBOL_REF: |
6801 | case LABEL_REF: | |
02e39abc JL |
6802 | return; |
6803 | ||
278a83b2 | 6804 | case CLOBBER: |
02e39abc JL |
6805 | /* If we are clobbering a MEM, mark any registers inside the address |
6806 | as being used. */ | |
3c0cb5de | 6807 | if (MEM_P (XEXP (x, 0))) |
b92ba6ff | 6808 | count_reg_usage (XEXP (XEXP (x, 0), 0), counts, NULL_RTX, incr); |
7afe21cc RK |
6809 | return; |
6810 | ||
6811 | case SET: | |
6812 | /* Unless we are setting a REG, count everything in SET_DEST. */ | |
f8cfc6aa | 6813 | if (!REG_P (SET_DEST (x))) |
b92ba6ff R |
6814 | count_reg_usage (SET_DEST (x), counts, NULL_RTX, incr); |
6815 | count_reg_usage (SET_SRC (x), counts, | |
6816 | dest ? dest : SET_DEST (x), | |
6817 | incr); | |
7afe21cc RK |
6818 | return; |
6819 | ||
b5b8b0ac AO |
6820 | case DEBUG_INSN: |
6821 | return; | |
6822 | ||
f1e7c95f | 6823 | case CALL_INSN: |
7afe21cc RK |
6824 | case INSN: |
6825 | case JUMP_INSN: | |
2da02156 | 6826 | /* We expect dest to be NULL_RTX here. If the insn may throw, |
34161e98 RS |
6827 | or if it cannot be deleted due to side-effects, mark this fact |
6828 | by setting DEST to pc_rtx. */ | |
2da02156 EB |
6829 | if ((!cfun->can_delete_dead_exceptions && !insn_nothrow_p (x)) |
6830 | || side_effects_p (PATTERN (x))) | |
b92ba6ff R |
6831 | dest = pc_rtx; |
6832 | if (code == CALL_INSN) | |
6833 | count_reg_usage (CALL_INSN_FUNCTION_USAGE (x), counts, dest, incr); | |
6834 | count_reg_usage (PATTERN (x), counts, dest, incr); | |
7afe21cc RK |
6835 | |
6836 | /* Things used in a REG_EQUAL note aren't dead since loop may try to | |
6837 | use them. */ | |
6838 | ||
b17d5d7c ZD |
6839 | note = find_reg_equal_equiv_note (x); |
6840 | if (note) | |
839844be R |
6841 | { |
6842 | rtx eqv = XEXP (note, 0); | |
6843 | ||
6844 | if (GET_CODE (eqv) == EXPR_LIST) | |
6845 | /* This REG_EQUAL note describes the result of a function call. | |
6846 | Process all the arguments. */ | |
6847 | do | |
6848 | { | |
b92ba6ff | 6849 | count_reg_usage (XEXP (eqv, 0), counts, dest, incr); |
839844be R |
6850 | eqv = XEXP (eqv, 1); |
6851 | } | |
6852 | while (eqv && GET_CODE (eqv) == EXPR_LIST); | |
6853 | else | |
b92ba6ff | 6854 | count_reg_usage (eqv, counts, dest, incr); |
839844be | 6855 | } |
7afe21cc RK |
6856 | return; |
6857 | ||
ee960939 OH |
6858 | case EXPR_LIST: |
6859 | if (REG_NOTE_KIND (x) == REG_EQUAL | |
6860 | || (REG_NOTE_KIND (x) != REG_NONNEG && GET_CODE (XEXP (x,0)) == USE) | |
6861 | /* FUNCTION_USAGE expression lists may include (CLOBBER (mem /u)), | |
6862 | involving registers in the address. */ | |
6863 | || GET_CODE (XEXP (x, 0)) == CLOBBER) | |
b92ba6ff | 6864 | count_reg_usage (XEXP (x, 0), counts, NULL_RTX, incr); |
ee960939 | 6865 | |
b92ba6ff | 6866 | count_reg_usage (XEXP (x, 1), counts, NULL_RTX, incr); |
ee960939 OH |
6867 | return; |
6868 | ||
a6c14a64 | 6869 | case ASM_OPERANDS: |
a6c14a64 RH |
6870 | /* Iterate over just the inputs, not the constraints as well. */ |
6871 | for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--) | |
b92ba6ff | 6872 | count_reg_usage (ASM_OPERANDS_INPUT (x, i), counts, dest, incr); |
a6c14a64 RH |
6873 | return; |
6874 | ||
7afe21cc | 6875 | case INSN_LIST: |
f91aec98 | 6876 | case INT_LIST: |
341c100f | 6877 | gcc_unreachable (); |
278a83b2 | 6878 | |
e9a25f70 JL |
6879 | default: |
6880 | break; | |
7afe21cc RK |
6881 | } |
6882 | ||
6883 | fmt = GET_RTX_FORMAT (code); | |
6884 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
6885 | { | |
6886 | if (fmt[i] == 'e') | |
b92ba6ff | 6887 | count_reg_usage (XEXP (x, i), counts, dest, incr); |
7afe21cc RK |
6888 | else if (fmt[i] == 'E') |
6889 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
b92ba6ff | 6890 | count_reg_usage (XVECEXP (x, i, j), counts, dest, incr); |
7afe21cc RK |
6891 | } |
6892 | } | |
6893 | \f | |
6699b754 | 6894 | /* Return true if X is a dead register. */ |
b5b8b0ac | 6895 | |
6699b754 | 6896 | static inline int |
a5b9bc17 | 6897 | is_dead_reg (const_rtx x, int *counts) |
b5b8b0ac | 6898 | { |
b5b8b0ac AO |
6899 | return (REG_P (x) |
6900 | && REGNO (x) >= FIRST_PSEUDO_REGISTER | |
6901 | && counts[REGNO (x)] == 0); | |
6902 | } | |
6903 | ||
4793dca1 JH |
6904 | /* Return true if set is live. */ |
6905 | static bool | |
20468884 | 6906 | set_live_p (rtx set, rtx_insn *insn ATTRIBUTE_UNUSED, /* Only used with HAVE_cc0. */ |
7080f735 | 6907 | int *counts) |
4793dca1 | 6908 | { |
e67d1102 | 6909 | rtx_insn *tem; |
4793dca1 JH |
6910 | |
6911 | if (set_noop_p (set)) | |
6912 | ; | |
6913 | ||
4793dca1 JH |
6914 | else if (GET_CODE (SET_DEST (set)) == CC0 |
6915 | && !side_effects_p (SET_SRC (set)) | |
5f262d13 | 6916 | && ((tem = next_nonnote_nondebug_insn (insn)) == NULL_RTX |
4793dca1 JH |
6917 | || !INSN_P (tem) |
6918 | || !reg_referenced_p (cc0_rtx, PATTERN (tem)))) | |
6919 | return false; | |
6699b754 | 6920 | else if (!is_dead_reg (SET_DEST (set), counts) |
8fff4fc1 | 6921 | || side_effects_p (SET_SRC (set))) |
4793dca1 JH |
6922 | return true; |
6923 | return false; | |
6924 | } | |
6925 | ||
6926 | /* Return true if insn is live. */ | |
6927 | ||
6928 | static bool | |
20468884 | 6929 | insn_live_p (rtx_insn *insn, int *counts) |
4793dca1 JH |
6930 | { |
6931 | int i; | |
2da02156 | 6932 | if (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) |
a646f6cc AH |
6933 | return true; |
6934 | else if (GET_CODE (PATTERN (insn)) == SET) | |
0021de69 | 6935 | return set_live_p (PATTERN (insn), insn, counts); |
4793dca1 | 6936 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) |
0021de69 DB |
6937 | { |
6938 | for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) | |
6939 | { | |
6940 | rtx elt = XVECEXP (PATTERN (insn), 0, i); | |
4793dca1 | 6941 | |
0021de69 DB |
6942 | if (GET_CODE (elt) == SET) |
6943 | { | |
6944 | if (set_live_p (elt, insn, counts)) | |
6945 | return true; | |
6946 | } | |
6947 | else if (GET_CODE (elt) != CLOBBER && GET_CODE (elt) != USE) | |
6948 | return true; | |
6949 | } | |
6950 | return false; | |
6951 | } | |
b5b8b0ac AO |
6952 | else if (DEBUG_INSN_P (insn)) |
6953 | { | |
20468884 | 6954 | rtx_insn *next; |
b5b8b0ac AO |
6955 | |
6956 | for (next = NEXT_INSN (insn); next; next = NEXT_INSN (next)) | |
6957 | if (NOTE_P (next)) | |
6958 | continue; | |
6959 | else if (!DEBUG_INSN_P (next)) | |
6960 | return true; | |
6961 | else if (INSN_VAR_LOCATION_DECL (insn) == INSN_VAR_LOCATION_DECL (next)) | |
6962 | return false; | |
6963 | ||
b5b8b0ac AO |
6964 | return true; |
6965 | } | |
4793dca1 JH |
6966 | else |
6967 | return true; | |
6968 | } | |
6969 | ||
6699b754 JJ |
6970 | /* Count the number of stores into pseudo. Callback for note_stores. */ |
6971 | ||
6972 | static void | |
6973 | count_stores (rtx x, const_rtx set ATTRIBUTE_UNUSED, void *data) | |
6974 | { | |
6975 | int *counts = (int *) data; | |
6976 | if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER) | |
6977 | counts[REGNO (x)]++; | |
6978 | } | |
6979 | ||
a5b9bc17 RS |
6980 | /* Return if DEBUG_INSN pattern PAT needs to be reset because some dead |
6981 | pseudo doesn't have a replacement. COUNTS[X] is zero if register X | |
6982 | is dead and REPLACEMENTS[X] is null if it has no replacemenet. | |
6983 | Set *SEEN_REPL to true if we see a dead register that does have | |
6984 | a replacement. */ | |
6699b754 | 6985 | |
a5b9bc17 RS |
6986 | static bool |
6987 | is_dead_debug_insn (const_rtx pat, int *counts, rtx *replacements, | |
6988 | bool *seen_repl) | |
6699b754 | 6989 | { |
a5b9bc17 RS |
6990 | subrtx_iterator::array_type array; |
6991 | FOR_EACH_SUBRTX (iter, array, pat, NONCONST) | |
6699b754 | 6992 | { |
a5b9bc17 RS |
6993 | const_rtx x = *iter; |
6994 | if (is_dead_reg (x, counts)) | |
6995 | { | |
6996 | if (replacements && replacements[REGNO (x)] != NULL_RTX) | |
6997 | *seen_repl = true; | |
6998 | else | |
6999 | return true; | |
7000 | } | |
6699b754 | 7001 | } |
a5b9bc17 | 7002 | return false; |
6699b754 JJ |
7003 | } |
7004 | ||
7005 | /* Replace a dead pseudo in a DEBUG_INSN with replacement DEBUG_EXPR. | |
7006 | Callback for simplify_replace_fn_rtx. */ | |
7007 | ||
7008 | static rtx | |
7009 | replace_dead_reg (rtx x, const_rtx old_rtx ATTRIBUTE_UNUSED, void *data) | |
7010 | { | |
7011 | rtx *replacements = (rtx *) data; | |
7012 | ||
7013 | if (REG_P (x) | |
7014 | && REGNO (x) >= FIRST_PSEUDO_REGISTER | |
7015 | && replacements[REGNO (x)] != NULL_RTX) | |
7016 | { | |
7017 | if (GET_MODE (x) == GET_MODE (replacements[REGNO (x)])) | |
7018 | return replacements[REGNO (x)]; | |
7019 | return lowpart_subreg (GET_MODE (x), replacements[REGNO (x)], | |
7020 | GET_MODE (replacements[REGNO (x)])); | |
7021 | } | |
7022 | return NULL_RTX; | |
7023 | } | |
7024 | ||
7afe21cc RK |
7025 | /* Scan all the insns and delete any that are dead; i.e., they store a register |
7026 | that is never used or they copy a register to itself. | |
7027 | ||
c6a26dc4 JL |
7028 | This is used to remove insns made obviously dead by cse, loop or other |
7029 | optimizations. It improves the heuristics in loop since it won't try to | |
7030 | move dead invariants out of loops or make givs for dead quantities. The | |
7031 | remaining passes of the compilation are also sped up. */ | |
7afe21cc | 7032 | |
3dec4024 | 7033 | int |
169d13f5 | 7034 | delete_trivially_dead_insns (rtx_insn *insns, int nreg) |
7afe21cc | 7035 | { |
4da896b2 | 7036 | int *counts; |
169d13f5 | 7037 | rtx_insn *insn, *prev; |
6699b754 | 7038 | rtx *replacements = NULL; |
65e9fa10 | 7039 | int ndead = 0; |
7afe21cc | 7040 | |
3dec4024 | 7041 | timevar_push (TV_DELETE_TRIVIALLY_DEAD); |
7afe21cc | 7042 | /* First count the number of times each register is used. */ |
6699b754 JJ |
7043 | if (MAY_HAVE_DEBUG_INSNS) |
7044 | { | |
7045 | counts = XCNEWVEC (int, nreg * 3); | |
7046 | for (insn = insns; insn; insn = NEXT_INSN (insn)) | |
7047 | if (DEBUG_INSN_P (insn)) | |
7048 | count_reg_usage (INSN_VAR_LOCATION_LOC (insn), counts + nreg, | |
7049 | NULL_RTX, 1); | |
7050 | else if (INSN_P (insn)) | |
7051 | { | |
7052 | count_reg_usage (insn, counts, NULL_RTX, 1); | |
7053 | note_stores (PATTERN (insn), count_stores, counts + nreg * 2); | |
7054 | } | |
7055 | /* If there can be debug insns, COUNTS are 3 consecutive arrays. | |
7056 | First one counts how many times each pseudo is used outside | |
7057 | of debug insns, second counts how many times each pseudo is | |
7058 | used in debug insns and third counts how many times a pseudo | |
7059 | is stored. */ | |
7060 | } | |
7061 | else | |
7062 | { | |
7063 | counts = XCNEWVEC (int, nreg); | |
7064 | for (insn = insns; insn; insn = NEXT_INSN (insn)) | |
7065 | if (INSN_P (insn)) | |
7066 | count_reg_usage (insn, counts, NULL_RTX, 1); | |
7067 | /* If no debug insns can be present, COUNTS is just an array | |
7068 | which counts how many times each pseudo is used. */ | |
7069 | } | |
56873e13 ES |
7070 | /* Pseudo PIC register should be considered as used due to possible |
7071 | new usages generated. */ | |
7072 | if (!reload_completed | |
7073 | && pic_offset_table_rtx | |
7074 | && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER) | |
7075 | counts[REGNO (pic_offset_table_rtx)]++; | |
65e9fa10 KH |
7076 | /* Go from the last insn to the first and delete insns that only set unused |
7077 | registers or copy a register to itself. As we delete an insn, remove | |
7078 | usage counts for registers it uses. | |
0cedb36c | 7079 | |
65e9fa10 KH |
7080 | The first jump optimization pass may leave a real insn as the last |
7081 | insn in the function. We must not skip that insn or we may end | |
6699b754 JJ |
7082 | up deleting code that is not really dead. |
7083 | ||
7084 | If some otherwise unused register is only used in DEBUG_INSNs, | |
7085 | try to create a DEBUG_EXPR temporary and emit a DEBUG_INSN before | |
7086 | the setter. Then go through DEBUG_INSNs and if a DEBUG_EXPR | |
7087 | has been created for the unused register, replace it with | |
7088 | the DEBUG_EXPR, otherwise reset the DEBUG_INSN. */ | |
03ce14db | 7089 | for (insn = get_last_insn (); insn; insn = prev) |
65e9fa10 KH |
7090 | { |
7091 | int live_insn = 0; | |
7afe21cc | 7092 | |
03ce14db KH |
7093 | prev = PREV_INSN (insn); |
7094 | if (!INSN_P (insn)) | |
7095 | continue; | |
7afe21cc | 7096 | |
4a8cae83 | 7097 | live_insn = insn_live_p (insn, counts); |
7afe21cc | 7098 | |
65e9fa10 KH |
7099 | /* If this is a dead insn, delete it and show registers in it aren't |
7100 | being used. */ | |
7afe21cc | 7101 | |
6fb5fa3c | 7102 | if (! live_insn && dbg_cnt (delete_trivial_dead)) |
65e9fa10 | 7103 | { |
6699b754 JJ |
7104 | if (DEBUG_INSN_P (insn)) |
7105 | count_reg_usage (INSN_VAR_LOCATION_LOC (insn), counts + nreg, | |
7106 | NULL_RTX, -1); | |
7107 | else | |
7108 | { | |
7109 | rtx set; | |
7110 | if (MAY_HAVE_DEBUG_INSNS | |
7111 | && (set = single_set (insn)) != NULL_RTX | |
7112 | && is_dead_reg (SET_DEST (set), counts) | |
7113 | /* Used at least once in some DEBUG_INSN. */ | |
7114 | && counts[REGNO (SET_DEST (set)) + nreg] > 0 | |
7115 | /* And set exactly once. */ | |
7116 | && counts[REGNO (SET_DEST (set)) + nreg * 2] == 1 | |
7117 | && !side_effects_p (SET_SRC (set)) | |
7118 | && asm_noperands (PATTERN (insn)) < 0) | |
7119 | { | |
b2908ba6 DM |
7120 | rtx dval, bind_var_loc; |
7121 | rtx_insn *bind; | |
6699b754 JJ |
7122 | |
7123 | /* Create DEBUG_EXPR (and DEBUG_EXPR_DECL). */ | |
7124 | dval = make_debug_expr_from_rtl (SET_DEST (set)); | |
7125 | ||
7126 | /* Emit a debug bind insn before the insn in which | |
7127 | reg dies. */ | |
b2908ba6 DM |
7128 | bind_var_loc = |
7129 | gen_rtx_VAR_LOCATION (GET_MODE (SET_DEST (set)), | |
7130 | DEBUG_EXPR_TREE_DECL (dval), | |
7131 | SET_SRC (set), | |
7132 | VAR_INIT_STATUS_INITIALIZED); | |
7133 | count_reg_usage (bind_var_loc, counts + nreg, NULL_RTX, 1); | |
7134 | ||
7135 | bind = emit_debug_insn_before (bind_var_loc, insn); | |
6699b754 JJ |
7136 | df_insn_rescan (bind); |
7137 | ||
7138 | if (replacements == NULL) | |
7139 | replacements = XCNEWVEC (rtx, nreg); | |
7140 | replacements[REGNO (SET_DEST (set))] = dval; | |
7141 | } | |
7142 | ||
7143 | count_reg_usage (insn, counts, NULL_RTX, -1); | |
7144 | ndead++; | |
7145 | } | |
98ccd1d7 | 7146 | cse_cfg_altered |= delete_insn_and_edges (insn); |
65e9fa10 | 7147 | } |
68252e27 | 7148 | } |
4da896b2 | 7149 | |
6699b754 JJ |
7150 | if (MAY_HAVE_DEBUG_INSNS) |
7151 | { | |
6699b754 JJ |
7152 | for (insn = get_last_insn (); insn; insn = PREV_INSN (insn)) |
7153 | if (DEBUG_INSN_P (insn)) | |
7154 | { | |
7155 | /* If this debug insn references a dead register that wasn't replaced | |
7156 | with an DEBUG_EXPR, reset the DEBUG_INSN. */ | |
a5b9bc17 RS |
7157 | bool seen_repl = false; |
7158 | if (is_dead_debug_insn (INSN_VAR_LOCATION_LOC (insn), | |
7159 | counts, replacements, &seen_repl)) | |
6699b754 JJ |
7160 | { |
7161 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); | |
7162 | df_insn_rescan (insn); | |
7163 | } | |
a5b9bc17 | 7164 | else if (seen_repl) |
6699b754 JJ |
7165 | { |
7166 | INSN_VAR_LOCATION_LOC (insn) | |
7167 | = simplify_replace_fn_rtx (INSN_VAR_LOCATION_LOC (insn), | |
7168 | NULL_RTX, replace_dead_reg, | |
7169 | replacements); | |
7170 | df_insn_rescan (insn); | |
7171 | } | |
7172 | } | |
04695783 | 7173 | free (replacements); |
6699b754 JJ |
7174 | } |
7175 | ||
c263766c | 7176 | if (dump_file && ndead) |
65e9fa10 KH |
7177 | fprintf (dump_file, "Deleted %i trivially dead insns\n", |
7178 | ndead); | |
4da896b2 MM |
7179 | /* Clean up. */ |
7180 | free (counts); | |
3dec4024 JH |
7181 | timevar_pop (TV_DELETE_TRIVIALLY_DEAD); |
7182 | return ndead; | |
7afe21cc | 7183 | } |
e129d93a | 7184 | |
a9052a40 RS |
7185 | /* If LOC contains references to NEWREG in a different mode, change them |
7186 | to use NEWREG instead. */ | |
e129d93a | 7187 | |
a9052a40 RS |
7188 | static void |
7189 | cse_change_cc_mode (subrtx_ptr_iterator::array_type &array, | |
88bdcd3d | 7190 | rtx *loc, rtx_insn *insn, rtx newreg) |
e129d93a | 7191 | { |
a9052a40 | 7192 | FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST) |
e129d93a | 7193 | { |
a9052a40 RS |
7194 | rtx *loc = *iter; |
7195 | rtx x = *loc; | |
7196 | if (x | |
7197 | && REG_P (x) | |
7198 | && REGNO (x) == REGNO (newreg) | |
7199 | && GET_MODE (x) != GET_MODE (newreg)) | |
7200 | { | |
7201 | validate_change (insn, loc, newreg, 1); | |
7202 | iter.skip_subrtxes (); | |
7203 | } | |
e129d93a | 7204 | } |
e129d93a ILT |
7205 | } |
7206 | ||
fc188d37 AK |
7207 | /* Change the mode of any reference to the register REGNO (NEWREG) to |
7208 | GET_MODE (NEWREG) in INSN. */ | |
7209 | ||
7210 | static void | |
20468884 | 7211 | cse_change_cc_mode_insn (rtx_insn *insn, rtx newreg) |
fc188d37 | 7212 | { |
fc188d37 AK |
7213 | int success; |
7214 | ||
7215 | if (!INSN_P (insn)) | |
7216 | return; | |
7217 | ||
a9052a40 RS |
7218 | subrtx_ptr_iterator::array_type array; |
7219 | cse_change_cc_mode (array, &PATTERN (insn), insn, newreg); | |
7220 | cse_change_cc_mode (array, ®_NOTES (insn), insn, newreg); | |
b8698a0f | 7221 | |
fc188d37 AK |
7222 | /* If the following assertion was triggered, there is most probably |
7223 | something wrong with the cc_modes_compatible back end function. | |
7224 | CC modes only can be considered compatible if the insn - with the mode | |
7225 | replaced by any of the compatible modes - can still be recognized. */ | |
7226 | success = apply_change_group (); | |
7227 | gcc_assert (success); | |
7228 | } | |
7229 | ||
e129d93a ILT |
7230 | /* Change the mode of any reference to the register REGNO (NEWREG) to |
7231 | GET_MODE (NEWREG), starting at START. Stop before END. Stop at | |
2e802a6f | 7232 | any instruction which modifies NEWREG. */ |
e129d93a ILT |
7233 | |
7234 | static void | |
20468884 | 7235 | cse_change_cc_mode_insns (rtx_insn *start, rtx_insn *end, rtx newreg) |
e129d93a | 7236 | { |
20468884 | 7237 | rtx_insn *insn; |
e129d93a ILT |
7238 | |
7239 | for (insn = start; insn != end; insn = NEXT_INSN (insn)) | |
7240 | { | |
7241 | if (! INSN_P (insn)) | |
7242 | continue; | |
7243 | ||
2e802a6f | 7244 | if (reg_set_p (newreg, insn)) |
e129d93a ILT |
7245 | return; |
7246 | ||
fc188d37 | 7247 | cse_change_cc_mode_insn (insn, newreg); |
e129d93a ILT |
7248 | } |
7249 | } | |
7250 | ||
7251 | /* BB is a basic block which finishes with CC_REG as a condition code | |
7252 | register which is set to CC_SRC. Look through the successors of BB | |
7253 | to find blocks which have a single predecessor (i.e., this one), | |
7254 | and look through those blocks for an assignment to CC_REG which is | |
7255 | equivalent to CC_SRC. CAN_CHANGE_MODE indicates whether we are | |
7256 | permitted to change the mode of CC_SRC to a compatible mode. This | |
7257 | returns VOIDmode if no equivalent assignments were found. | |
7258 | Otherwise it returns the mode which CC_SRC should wind up with. | |
31e9ebaf JJ |
7259 | ORIG_BB should be the same as BB in the outermost cse_cc_succs call, |
7260 | but is passed unmodified down to recursive calls in order to prevent | |
7261 | endless recursion. | |
e129d93a ILT |
7262 | |
7263 | The main complexity in this function is handling the mode issues. | |
7264 | We may have more than one duplicate which we can eliminate, and we | |
7265 | try to find a mode which will work for multiple duplicates. */ | |
7266 | ||
ef4bddc2 | 7267 | static machine_mode |
31e9ebaf JJ |
7268 | cse_cc_succs (basic_block bb, basic_block orig_bb, rtx cc_reg, rtx cc_src, |
7269 | bool can_change_mode) | |
e129d93a ILT |
7270 | { |
7271 | bool found_equiv; | |
ef4bddc2 | 7272 | machine_mode mode; |
e129d93a ILT |
7273 | unsigned int insn_count; |
7274 | edge e; | |
20468884 | 7275 | rtx_insn *insns[2]; |
ef4bddc2 | 7276 | machine_mode modes[2]; |
20468884 | 7277 | rtx_insn *last_insns[2]; |
e129d93a ILT |
7278 | unsigned int i; |
7279 | rtx newreg; | |
628f6a4e | 7280 | edge_iterator ei; |
e129d93a ILT |
7281 | |
7282 | /* We expect to have two successors. Look at both before picking | |
7283 | the final mode for the comparison. If we have more successors | |
7284 | (i.e., some sort of table jump, although that seems unlikely), | |
7285 | then we require all beyond the first two to use the same | |
7286 | mode. */ | |
7287 | ||
7288 | found_equiv = false; | |
7289 | mode = GET_MODE (cc_src); | |
7290 | insn_count = 0; | |
628f6a4e | 7291 | FOR_EACH_EDGE (e, ei, bb->succs) |
e129d93a | 7292 | { |
20468884 DM |
7293 | rtx_insn *insn; |
7294 | rtx_insn *end; | |
e129d93a ILT |
7295 | |
7296 | if (e->flags & EDGE_COMPLEX) | |
7297 | continue; | |
7298 | ||
628f6a4e | 7299 | if (EDGE_COUNT (e->dest->preds) != 1 |
fefa31b5 | 7300 | || e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
31e9ebaf JJ |
7301 | /* Avoid endless recursion on unreachable blocks. */ |
7302 | || e->dest == orig_bb) | |
e129d93a ILT |
7303 | continue; |
7304 | ||
7305 | end = NEXT_INSN (BB_END (e->dest)); | |
7306 | for (insn = BB_HEAD (e->dest); insn != end; insn = NEXT_INSN (insn)) | |
7307 | { | |
7308 | rtx set; | |
7309 | ||
7310 | if (! INSN_P (insn)) | |
7311 | continue; | |
7312 | ||
7313 | /* If CC_SRC is modified, we have to stop looking for | |
7314 | something which uses it. */ | |
7315 | if (modified_in_p (cc_src, insn)) | |
7316 | break; | |
7317 | ||
7318 | /* Check whether INSN sets CC_REG to CC_SRC. */ | |
7319 | set = single_set (insn); | |
7320 | if (set | |
f8cfc6aa | 7321 | && REG_P (SET_DEST (set)) |
e129d93a ILT |
7322 | && REGNO (SET_DEST (set)) == REGNO (cc_reg)) |
7323 | { | |
7324 | bool found; | |
ef4bddc2 RS |
7325 | machine_mode set_mode; |
7326 | machine_mode comp_mode; | |
e129d93a ILT |
7327 | |
7328 | found = false; | |
7329 | set_mode = GET_MODE (SET_SRC (set)); | |
7330 | comp_mode = set_mode; | |
7331 | if (rtx_equal_p (cc_src, SET_SRC (set))) | |
7332 | found = true; | |
7333 | else if (GET_CODE (cc_src) == COMPARE | |
7334 | && GET_CODE (SET_SRC (set)) == COMPARE | |
1f44254c | 7335 | && mode != set_mode |
e129d93a ILT |
7336 | && rtx_equal_p (XEXP (cc_src, 0), |
7337 | XEXP (SET_SRC (set), 0)) | |
7338 | && rtx_equal_p (XEXP (cc_src, 1), | |
7339 | XEXP (SET_SRC (set), 1))) | |
b8698a0f | 7340 | |
e129d93a | 7341 | { |
5fd9b178 | 7342 | comp_mode = targetm.cc_modes_compatible (mode, set_mode); |
e129d93a ILT |
7343 | if (comp_mode != VOIDmode |
7344 | && (can_change_mode || comp_mode == mode)) | |
7345 | found = true; | |
7346 | } | |
7347 | ||
7348 | if (found) | |
7349 | { | |
7350 | found_equiv = true; | |
1f44254c | 7351 | if (insn_count < ARRAY_SIZE (insns)) |
e129d93a ILT |
7352 | { |
7353 | insns[insn_count] = insn; | |
7354 | modes[insn_count] = set_mode; | |
7355 | last_insns[insn_count] = end; | |
7356 | ++insn_count; | |
7357 | ||
1f44254c ILT |
7358 | if (mode != comp_mode) |
7359 | { | |
341c100f | 7360 | gcc_assert (can_change_mode); |
1f44254c | 7361 | mode = comp_mode; |
fc188d37 AK |
7362 | |
7363 | /* The modified insn will be re-recognized later. */ | |
1f44254c ILT |
7364 | PUT_MODE (cc_src, mode); |
7365 | } | |
e129d93a ILT |
7366 | } |
7367 | else | |
7368 | { | |
7369 | if (set_mode != mode) | |
1f44254c ILT |
7370 | { |
7371 | /* We found a matching expression in the | |
7372 | wrong mode, but we don't have room to | |
7373 | store it in the array. Punt. This case | |
7374 | should be rare. */ | |
7375 | break; | |
7376 | } | |
e129d93a ILT |
7377 | /* INSN sets CC_REG to a value equal to CC_SRC |
7378 | with the right mode. We can simply delete | |
7379 | it. */ | |
7380 | delete_insn (insn); | |
7381 | } | |
7382 | ||
7383 | /* We found an instruction to delete. Keep looking, | |
7384 | in the hopes of finding a three-way jump. */ | |
7385 | continue; | |
7386 | } | |
7387 | ||
7388 | /* We found an instruction which sets the condition | |
7389 | code, so don't look any farther. */ | |
7390 | break; | |
7391 | } | |
7392 | ||
7393 | /* If INSN sets CC_REG in some other way, don't look any | |
7394 | farther. */ | |
7395 | if (reg_set_p (cc_reg, insn)) | |
7396 | break; | |
7397 | } | |
7398 | ||
7399 | /* If we fell off the bottom of the block, we can keep looking | |
7400 | through successors. We pass CAN_CHANGE_MODE as false because | |
7401 | we aren't prepared to handle compatibility between the | |
7402 | further blocks and this block. */ | |
7403 | if (insn == end) | |
7404 | { | |
ef4bddc2 | 7405 | machine_mode submode; |
1f44254c | 7406 | |
31e9ebaf | 7407 | submode = cse_cc_succs (e->dest, orig_bb, cc_reg, cc_src, false); |
1f44254c ILT |
7408 | if (submode != VOIDmode) |
7409 | { | |
341c100f | 7410 | gcc_assert (submode == mode); |
1f44254c ILT |
7411 | found_equiv = true; |
7412 | can_change_mode = false; | |
7413 | } | |
e129d93a ILT |
7414 | } |
7415 | } | |
7416 | ||
7417 | if (! found_equiv) | |
7418 | return VOIDmode; | |
7419 | ||
7420 | /* Now INSN_COUNT is the number of instructions we found which set | |
7421 | CC_REG to a value equivalent to CC_SRC. The instructions are in | |
7422 | INSNS. The modes used by those instructions are in MODES. */ | |
7423 | ||
7424 | newreg = NULL_RTX; | |
7425 | for (i = 0; i < insn_count; ++i) | |
7426 | { | |
7427 | if (modes[i] != mode) | |
7428 | { | |
7429 | /* We need to change the mode of CC_REG in INSNS[i] and | |
7430 | subsequent instructions. */ | |
7431 | if (! newreg) | |
7432 | { | |
7433 | if (GET_MODE (cc_reg) == mode) | |
7434 | newreg = cc_reg; | |
7435 | else | |
7436 | newreg = gen_rtx_REG (mode, REGNO (cc_reg)); | |
7437 | } | |
7438 | cse_change_cc_mode_insns (NEXT_INSN (insns[i]), last_insns[i], | |
7439 | newreg); | |
7440 | } | |
7441 | ||
98ccd1d7 | 7442 | cse_cfg_altered |= delete_insn_and_edges (insns[i]); |
e129d93a ILT |
7443 | } |
7444 | ||
7445 | return mode; | |
7446 | } | |
7447 | ||
7448 | /* If we have a fixed condition code register (or two), walk through | |
7449 | the instructions and try to eliminate duplicate assignments. */ | |
7450 | ||
cab2264d | 7451 | static void |
e129d93a ILT |
7452 | cse_condition_code_reg (void) |
7453 | { | |
7454 | unsigned int cc_regno_1; | |
7455 | unsigned int cc_regno_2; | |
7456 | rtx cc_reg_1; | |
7457 | rtx cc_reg_2; | |
7458 | basic_block bb; | |
7459 | ||
5fd9b178 | 7460 | if (! targetm.fixed_condition_code_regs (&cc_regno_1, &cc_regno_2)) |
e129d93a ILT |
7461 | return; |
7462 | ||
7463 | cc_reg_1 = gen_rtx_REG (CCmode, cc_regno_1); | |
7464 | if (cc_regno_2 != INVALID_REGNUM) | |
7465 | cc_reg_2 = gen_rtx_REG (CCmode, cc_regno_2); | |
7466 | else | |
7467 | cc_reg_2 = NULL_RTX; | |
7468 | ||
11cd3bed | 7469 | FOR_EACH_BB_FN (bb, cfun) |
e129d93a | 7470 | { |
20468884 | 7471 | rtx_insn *last_insn; |
e129d93a | 7472 | rtx cc_reg; |
20468884 DM |
7473 | rtx_insn *insn; |
7474 | rtx_insn *cc_src_insn; | |
e129d93a | 7475 | rtx cc_src; |
ef4bddc2 RS |
7476 | machine_mode mode; |
7477 | machine_mode orig_mode; | |
e129d93a ILT |
7478 | |
7479 | /* Look for blocks which end with a conditional jump based on a | |
7480 | condition code register. Then look for the instruction which | |
7481 | sets the condition code register. Then look through the | |
7482 | successor blocks for instructions which set the condition | |
7483 | code register to the same value. There are other possible | |
7484 | uses of the condition code register, but these are by far the | |
7485 | most common and the ones which we are most likely to be able | |
7486 | to optimize. */ | |
7487 | ||
7488 | last_insn = BB_END (bb); | |
4b4bf941 | 7489 | if (!JUMP_P (last_insn)) |
e129d93a ILT |
7490 | continue; |
7491 | ||
7492 | if (reg_referenced_p (cc_reg_1, PATTERN (last_insn))) | |
7493 | cc_reg = cc_reg_1; | |
7494 | else if (cc_reg_2 && reg_referenced_p (cc_reg_2, PATTERN (last_insn))) | |
7495 | cc_reg = cc_reg_2; | |
7496 | else | |
7497 | continue; | |
7498 | ||
20468884 | 7499 | cc_src_insn = NULL; |
e129d93a ILT |
7500 | cc_src = NULL_RTX; |
7501 | for (insn = PREV_INSN (last_insn); | |
7502 | insn && insn != PREV_INSN (BB_HEAD (bb)); | |
7503 | insn = PREV_INSN (insn)) | |
7504 | { | |
7505 | rtx set; | |
7506 | ||
7507 | if (! INSN_P (insn)) | |
7508 | continue; | |
7509 | set = single_set (insn); | |
7510 | if (set | |
f8cfc6aa | 7511 | && REG_P (SET_DEST (set)) |
e129d93a ILT |
7512 | && REGNO (SET_DEST (set)) == REGNO (cc_reg)) |
7513 | { | |
7514 | cc_src_insn = insn; | |
7515 | cc_src = SET_SRC (set); | |
7516 | break; | |
7517 | } | |
7518 | else if (reg_set_p (cc_reg, insn)) | |
7519 | break; | |
7520 | } | |
7521 | ||
7522 | if (! cc_src_insn) | |
7523 | continue; | |
7524 | ||
7525 | if (modified_between_p (cc_src, cc_src_insn, NEXT_INSN (last_insn))) | |
7526 | continue; | |
7527 | ||
7528 | /* Now CC_REG is a condition code register used for a | |
7529 | conditional jump at the end of the block, and CC_SRC, in | |
7530 | CC_SRC_INSN, is the value to which that condition code | |
7531 | register is set, and CC_SRC is still meaningful at the end of | |
7532 | the basic block. */ | |
7533 | ||
1f44254c | 7534 | orig_mode = GET_MODE (cc_src); |
31e9ebaf | 7535 | mode = cse_cc_succs (bb, bb, cc_reg, cc_src, true); |
1f44254c | 7536 | if (mode != VOIDmode) |
e129d93a | 7537 | { |
341c100f | 7538 | gcc_assert (mode == GET_MODE (cc_src)); |
1f44254c | 7539 | if (mode != orig_mode) |
2e802a6f KH |
7540 | { |
7541 | rtx newreg = gen_rtx_REG (mode, REGNO (cc_reg)); | |
7542 | ||
fc188d37 | 7543 | cse_change_cc_mode_insn (cc_src_insn, newreg); |
2e802a6f KH |
7544 | |
7545 | /* Do the same in the following insns that use the | |
7546 | current value of CC_REG within BB. */ | |
7547 | cse_change_cc_mode_insns (NEXT_INSN (cc_src_insn), | |
7548 | NEXT_INSN (last_insn), | |
7549 | newreg); | |
7550 | } | |
e129d93a ILT |
7551 | } |
7552 | } | |
7553 | } | |
ef330312 PB |
7554 | \f |
7555 | ||
7556 | /* Perform common subexpression elimination. Nonzero value from | |
7557 | `cse_main' means that jumps were simplified and some code may now | |
7558 | be unreachable, so do jump optimization again. */ | |
c2924966 | 7559 | static unsigned int |
ef330312 PB |
7560 | rest_of_handle_cse (void) |
7561 | { | |
7562 | int tem; | |
6fb5fa3c | 7563 | |
ef330312 | 7564 | if (dump_file) |
5b4fdb20 | 7565 | dump_flow_info (dump_file, dump_flags); |
ef330312 | 7566 | |
10d22567 | 7567 | tem = cse_main (get_insns (), max_reg_num ()); |
ef330312 PB |
7568 | |
7569 | /* If we are not running more CSE passes, then we are no longer | |
7570 | expecting CSE to be run. But always rerun it in a cheap mode. */ | |
7571 | cse_not_expected = !flag_rerun_cse_after_loop && !flag_gcse; | |
7572 | ||
2aac3a01 EB |
7573 | if (tem == 2) |
7574 | { | |
7575 | timevar_push (TV_JUMP); | |
7576 | rebuild_jump_labels (get_insns ()); | |
da7674f6 | 7577 | cse_cfg_altered |= cleanup_cfg (CLEANUP_CFG_CHANGED); |
2aac3a01 EB |
7578 | timevar_pop (TV_JUMP); |
7579 | } | |
7580 | else if (tem == 1 || optimize > 1) | |
da7674f6 | 7581 | cse_cfg_altered |= cleanup_cfg (0); |
932ad4d9 | 7582 | |
c2924966 | 7583 | return 0; |
ef330312 PB |
7584 | } |
7585 | ||
27a4cd48 DM |
7586 | namespace { |
7587 | ||
7588 | const pass_data pass_data_cse = | |
ef330312 | 7589 | { |
27a4cd48 DM |
7590 | RTL_PASS, /* type */ |
7591 | "cse1", /* name */ | |
7592 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
7593 | TV_CSE, /* tv_id */ |
7594 | 0, /* properties_required */ | |
7595 | 0, /* properties_provided */ | |
7596 | 0, /* properties_destroyed */ | |
7597 | 0, /* todo_flags_start */ | |
3bea341f | 7598 | TODO_df_finish, /* todo_flags_finish */ |
ef330312 PB |
7599 | }; |
7600 | ||
27a4cd48 DM |
7601 | class pass_cse : public rtl_opt_pass |
7602 | { | |
7603 | public: | |
c3284718 RS |
7604 | pass_cse (gcc::context *ctxt) |
7605 | : rtl_opt_pass (pass_data_cse, ctxt) | |
27a4cd48 DM |
7606 | {} |
7607 | ||
7608 | /* opt_pass methods: */ | |
1a3d085c | 7609 | virtual bool gate (function *) { return optimize > 0; } |
be55bfe6 | 7610 | virtual unsigned int execute (function *) { return rest_of_handle_cse (); } |
27a4cd48 DM |
7611 | |
7612 | }; // class pass_cse | |
7613 | ||
7614 | } // anon namespace | |
7615 | ||
7616 | rtl_opt_pass * | |
7617 | make_pass_cse (gcc::context *ctxt) | |
7618 | { | |
7619 | return new pass_cse (ctxt); | |
7620 | } | |
7621 | ||
ef330312 | 7622 | |
ef330312 | 7623 | /* Run second CSE pass after loop optimizations. */ |
c2924966 | 7624 | static unsigned int |
ef330312 PB |
7625 | rest_of_handle_cse2 (void) |
7626 | { | |
7627 | int tem; | |
7628 | ||
7629 | if (dump_file) | |
5b4fdb20 | 7630 | dump_flow_info (dump_file, dump_flags); |
ef330312 | 7631 | |
10d22567 | 7632 | tem = cse_main (get_insns (), max_reg_num ()); |
ef330312 PB |
7633 | |
7634 | /* Run a pass to eliminate duplicated assignments to condition code | |
7635 | registers. We have to run this after bypass_jumps, because it | |
7636 | makes it harder for that pass to determine whether a jump can be | |
7637 | bypassed safely. */ | |
7638 | cse_condition_code_reg (); | |
7639 | ||
ef330312 PB |
7640 | delete_trivially_dead_insns (get_insns (), max_reg_num ()); |
7641 | ||
2aac3a01 | 7642 | if (tem == 2) |
ef330312 PB |
7643 | { |
7644 | timevar_push (TV_JUMP); | |
7645 | rebuild_jump_labels (get_insns ()); | |
da7674f6 | 7646 | cse_cfg_altered |= cleanup_cfg (CLEANUP_CFG_CHANGED); |
ef330312 PB |
7647 | timevar_pop (TV_JUMP); |
7648 | } | |
2aac3a01 | 7649 | else if (tem == 1) |
da7674f6 | 7650 | cse_cfg_altered |= cleanup_cfg (0); |
2aac3a01 | 7651 | |
ef330312 | 7652 | cse_not_expected = 1; |
c2924966 | 7653 | return 0; |
ef330312 PB |
7654 | } |
7655 | ||
7656 | ||
27a4cd48 DM |
7657 | namespace { |
7658 | ||
7659 | const pass_data pass_data_cse2 = | |
ef330312 | 7660 | { |
27a4cd48 DM |
7661 | RTL_PASS, /* type */ |
7662 | "cse2", /* name */ | |
7663 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
7664 | TV_CSE2, /* tv_id */ |
7665 | 0, /* properties_required */ | |
7666 | 0, /* properties_provided */ | |
7667 | 0, /* properties_destroyed */ | |
7668 | 0, /* todo_flags_start */ | |
3bea341f | 7669 | TODO_df_finish, /* todo_flags_finish */ |
ef330312 | 7670 | }; |
5f39ad47 | 7671 | |
27a4cd48 DM |
7672 | class pass_cse2 : public rtl_opt_pass |
7673 | { | |
7674 | public: | |
c3284718 RS |
7675 | pass_cse2 (gcc::context *ctxt) |
7676 | : rtl_opt_pass (pass_data_cse2, ctxt) | |
27a4cd48 DM |
7677 | {} |
7678 | ||
7679 | /* opt_pass methods: */ | |
1a3d085c TS |
7680 | virtual bool gate (function *) |
7681 | { | |
7682 | return optimize > 0 && flag_rerun_cse_after_loop; | |
7683 | } | |
7684 | ||
be55bfe6 | 7685 | virtual unsigned int execute (function *) { return rest_of_handle_cse2 (); } |
27a4cd48 DM |
7686 | |
7687 | }; // class pass_cse2 | |
7688 | ||
7689 | } // anon namespace | |
7690 | ||
7691 | rtl_opt_pass * | |
7692 | make_pass_cse2 (gcc::context *ctxt) | |
7693 | { | |
7694 | return new pass_cse2 (ctxt); | |
7695 | } | |
7696 | ||
5f39ad47 SB |
7697 | /* Run second CSE pass after loop optimizations. */ |
7698 | static unsigned int | |
7699 | rest_of_handle_cse_after_global_opts (void) | |
7700 | { | |
7701 | int save_cfj; | |
7702 | int tem; | |
7703 | ||
7704 | /* We only want to do local CSE, so don't follow jumps. */ | |
7705 | save_cfj = flag_cse_follow_jumps; | |
7706 | flag_cse_follow_jumps = 0; | |
7707 | ||
7708 | rebuild_jump_labels (get_insns ()); | |
7709 | tem = cse_main (get_insns (), max_reg_num ()); | |
98ccd1d7 | 7710 | cse_cfg_altered |= purge_all_dead_edges (); |
5f39ad47 SB |
7711 | delete_trivially_dead_insns (get_insns (), max_reg_num ()); |
7712 | ||
7713 | cse_not_expected = !flag_rerun_cse_after_loop; | |
7714 | ||
7715 | /* If cse altered any jumps, rerun jump opts to clean things up. */ | |
7716 | if (tem == 2) | |
7717 | { | |
7718 | timevar_push (TV_JUMP); | |
7719 | rebuild_jump_labels (get_insns ()); | |
da7674f6 | 7720 | cse_cfg_altered |= cleanup_cfg (CLEANUP_CFG_CHANGED); |
5f39ad47 SB |
7721 | timevar_pop (TV_JUMP); |
7722 | } | |
7723 | else if (tem == 1) | |
da7674f6 | 7724 | cse_cfg_altered |= cleanup_cfg (0); |
5f39ad47 SB |
7725 | |
7726 | flag_cse_follow_jumps = save_cfj; | |
7727 | return 0; | |
7728 | } | |
7729 | ||
27a4cd48 DM |
7730 | namespace { |
7731 | ||
7732 | const pass_data pass_data_cse_after_global_opts = | |
5f39ad47 | 7733 | { |
27a4cd48 DM |
7734 | RTL_PASS, /* type */ |
7735 | "cse_local", /* name */ | |
7736 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
7737 | TV_CSE, /* tv_id */ |
7738 | 0, /* properties_required */ | |
7739 | 0, /* properties_provided */ | |
7740 | 0, /* properties_destroyed */ | |
7741 | 0, /* todo_flags_start */ | |
3bea341f | 7742 | TODO_df_finish, /* todo_flags_finish */ |
5f39ad47 | 7743 | }; |
27a4cd48 DM |
7744 | |
7745 | class pass_cse_after_global_opts : public rtl_opt_pass | |
7746 | { | |
7747 | public: | |
c3284718 RS |
7748 | pass_cse_after_global_opts (gcc::context *ctxt) |
7749 | : rtl_opt_pass (pass_data_cse_after_global_opts, ctxt) | |
27a4cd48 DM |
7750 | {} |
7751 | ||
7752 | /* opt_pass methods: */ | |
1a3d085c TS |
7753 | virtual bool gate (function *) |
7754 | { | |
7755 | return optimize > 0 && flag_rerun_cse_after_global_opts; | |
7756 | } | |
7757 | ||
be55bfe6 TS |
7758 | virtual unsigned int execute (function *) |
7759 | { | |
7760 | return rest_of_handle_cse_after_global_opts (); | |
7761 | } | |
27a4cd48 DM |
7762 | |
7763 | }; // class pass_cse_after_global_opts | |
7764 | ||
7765 | } // anon namespace | |
7766 | ||
7767 | rtl_opt_pass * | |
7768 | make_pass_cse_after_global_opts (gcc::context *ctxt) | |
7769 | { | |
7770 | return new pass_cse_after_global_opts (ctxt); | |
7771 | } |