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3072d30e | 1 | /* RTL dead store elimination. |
d353bf18 | 2 | Copyright (C) 2005-2015 Free Software Foundation, Inc. |
3072d30e | 3 | |
4 | Contributed by Richard Sandiford <rsandifor@codesourcery.com> | |
5 | and Kenneth Zadeck <zadeck@naturalbridge.com> | |
6 | ||
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it under | |
10 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 11 | Software Foundation; either version 3, or (at your option) any later |
3072d30e | 12 | version. |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
15 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
17 | for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
3072d30e | 22 | |
23 | #undef BASELINE | |
24 | ||
25 | #include "config.h" | |
26 | #include "system.h" | |
27 | #include "coretypes.h" | |
9ef16211 | 28 | #include "backend.h" |
d040a5b0 | 29 | #include "predict.h" |
9ef16211 | 30 | #include "tree.h" |
31 | #include "gimple.h" | |
3072d30e | 32 | #include "rtl.h" |
9ef16211 | 33 | #include "df.h" |
b20a8bb4 | 34 | #include "alias.h" |
b20a8bb4 | 35 | #include "fold-const.h" |
9ed99284 | 36 | #include "stor-layout.h" |
10d4de0e | 37 | #include "tm_p.h" |
3072d30e | 38 | #include "regs.h" |
5a9ecd4a | 39 | #include "regset.h" |
3072d30e | 40 | #include "flags.h" |
94ea8568 | 41 | #include "cfgrtl.h" |
3072d30e | 42 | #include "cselib.h" |
3072d30e | 43 | #include "tree-pass.h" |
44 | #include "alloc-pool.h" | |
3072d30e | 45 | #include "insn-config.h" |
d53441c8 | 46 | #include "expmed.h" |
47 | #include "dojump.h" | |
48 | #include "explow.h" | |
49 | #include "calls.h" | |
50 | #include "emit-rtl.h" | |
51 | #include "varasm.h" | |
52 | #include "stmt.h" | |
3072d30e | 53 | #include "expr.h" |
54 | #include "recog.h" | |
34517c64 | 55 | #include "insn-codes.h" |
5c9051a4 | 56 | #include "optabs.h" |
3072d30e | 57 | #include "dbgcnt.h" |
9311ed8a | 58 | #include "target.h" |
1242bee6 | 59 | #include "params.h" |
bc61cadb | 60 | #include "internal-fn.h" |
073c1fd5 | 61 | #include "gimple-ssa.h" |
ec1203cd | 62 | #include "rtl-iter.h" |
1f91a12d | 63 | #include "cfgcleanup.h" |
3072d30e | 64 | |
65 | /* This file contains three techniques for performing Dead Store | |
48e1416a | 66 | Elimination (dse). |
3072d30e | 67 | |
68 | * The first technique performs dse locally on any base address. It | |
69 | is based on the cselib which is a local value numbering technique. | |
70 | This technique is local to a basic block but deals with a fairly | |
71 | general addresses. | |
48e1416a | 72 | |
3072d30e | 73 | * The second technique performs dse globally but is restricted to |
74 | base addresses that are either constant or are relative to the | |
75 | frame_pointer. | |
76 | ||
77 | * The third technique, (which is only done after register allocation) | |
47ae02b7 | 78 | processes the spill slots. This differs from the second |
3072d30e | 79 | technique because it takes advantage of the fact that spilling is |
80 | completely free from the effects of aliasing. | |
81 | ||
82 | Logically, dse is a backwards dataflow problem. A store can be | |
83 | deleted if it if cannot be reached in the backward direction by any | |
84 | use of the value being stored. However, the local technique uses a | |
85 | forwards scan of the basic block because cselib requires that the | |
86 | block be processed in that order. | |
87 | ||
88 | The pass is logically broken into 7 steps: | |
89 | ||
90 | 0) Initialization. | |
91 | ||
92 | 1) The local algorithm, as well as scanning the insns for the two | |
93 | global algorithms. | |
94 | ||
95 | 2) Analysis to see if the global algs are necessary. In the case | |
96 | of stores base on a constant address, there must be at least two | |
97 | stores to that address, to make it possible to delete some of the | |
98 | stores. In the case of stores off of the frame or spill related | |
99 | stores, only one store to an address is necessary because those | |
100 | stores die at the end of the function. | |
101 | ||
48e1416a | 102 | 3) Set up the global dataflow equations based on processing the |
3072d30e | 103 | info parsed in the first step. |
104 | ||
105 | 4) Solve the dataflow equations. | |
106 | ||
107 | 5) Delete the insns that the global analysis has indicated are | |
108 | unnecessary. | |
109 | ||
9d75589a | 110 | 6) Delete insns that store the same value as preceding store |
aa140b76 | 111 | where the earlier store couldn't be eliminated. |
112 | ||
113 | 7) Cleanup. | |
3072d30e | 114 | |
115 | This step uses cselib and canon_rtx to build the largest expression | |
116 | possible for each address. This pass is a forwards pass through | |
117 | each basic block. From the point of view of the global technique, | |
118 | the first pass could examine a block in either direction. The | |
bef304b8 | 119 | forwards ordering is to accommodate cselib. |
3072d30e | 120 | |
2d0fd66d | 121 | We make a simplifying assumption: addresses fall into four broad |
3072d30e | 122 | categories: |
123 | ||
124 | 1) base has rtx_varies_p == false, offset is constant. | |
125 | 2) base has rtx_varies_p == false, offset variable. | |
126 | 3) base has rtx_varies_p == true, offset constant. | |
127 | 4) base has rtx_varies_p == true, offset variable. | |
128 | ||
129 | The local passes are able to process all 4 kinds of addresses. The | |
2d0fd66d | 130 | global pass only handles 1). |
3072d30e | 131 | |
132 | The global problem is formulated as follows: | |
133 | ||
134 | A store, S1, to address A, where A is not relative to the stack | |
135 | frame, can be eliminated if all paths from S1 to the end of the | |
2d0fd66d | 136 | function contain another store to A before a read to A. |
3072d30e | 137 | |
138 | If the address A is relative to the stack frame, a store S2 to A | |
2d0fd66d | 139 | can be eliminated if there are no paths from S2 that reach the |
3072d30e | 140 | end of the function that read A before another store to A. In |
2d0fd66d | 141 | this case S2 can be deleted if there are paths from S2 to the |
3072d30e | 142 | end of the function that have no reads or writes to A. This |
143 | second case allows stores to the stack frame to be deleted that | |
144 | would otherwise die when the function returns. This cannot be | |
145 | done if stores_off_frame_dead_at_return is not true. See the doc | |
146 | for that variable for when this variable is false. | |
147 | ||
148 | The global problem is formulated as a backwards set union | |
149 | dataflow problem where the stores are the gens and reads are the | |
150 | kills. Set union problems are rare and require some special | |
151 | handling given our representation of bitmaps. A straightforward | |
2d0fd66d | 152 | implementation requires a lot of bitmaps filled with 1s. |
3072d30e | 153 | These are expensive and cumbersome in our bitmap formulation so |
154 | care has been taken to avoid large vectors filled with 1s. See | |
155 | the comments in bb_info and in the dataflow confluence functions | |
48e1416a | 156 | for details. |
3072d30e | 157 | |
158 | There are two places for further enhancements to this algorithm: | |
48e1416a | 159 | |
3072d30e | 160 | 1) The original dse which was embedded in a pass called flow also |
161 | did local address forwarding. For example in | |
162 | ||
163 | A <- r100 | |
164 | ... <- A | |
165 | ||
166 | flow would replace the right hand side of the second insn with a | |
6dfdc153 | 167 | reference to r100. Most of the information is available to add this |
3072d30e | 168 | to this pass. It has not done it because it is a lot of work in |
169 | the case that either r100 is assigned to between the first and | |
170 | second insn and/or the second insn is a load of part of the value | |
171 | stored by the first insn. | |
172 | ||
173 | insn 5 in gcc.c-torture/compile/990203-1.c simple case. | |
174 | insn 15 in gcc.c-torture/execute/20001017-2.c simple case. | |
175 | insn 25 in gcc.c-torture/execute/20001026-1.c simple case. | |
176 | insn 44 in gcc.c-torture/execute/20010910-1.c simple case. | |
177 | ||
178 | 2) The cleaning up of spill code is quite profitable. It currently | |
179 | depends on reading tea leaves and chicken entrails left by reload. | |
180 | This pass depends on reload creating a singleton alias set for each | |
181 | spill slot and telling the next dse pass which of these alias sets | |
182 | are the singletons. Rather than analyze the addresses of the | |
183 | spills, dse's spill processing just does analysis of the loads and | |
184 | stores that use those alias sets. There are three cases where this | |
185 | falls short: | |
186 | ||
187 | a) Reload sometimes creates the slot for one mode of access, and | |
188 | then inserts loads and/or stores for a smaller mode. In this | |
189 | case, the current code just punts on the slot. The proper thing | |
190 | to do is to back out and use one bit vector position for each | |
191 | byte of the entity associated with the slot. This depends on | |
192 | KNOWING that reload always generates the accesses for each of the | |
193 | bytes in some canonical (read that easy to understand several | |
194 | passes after reload happens) way. | |
195 | ||
196 | b) Reload sometimes decides that spill slot it allocated was not | |
197 | large enough for the mode and goes back and allocates more slots | |
198 | with the same mode and alias set. The backout in this case is a | |
199 | little more graceful than (a). In this case the slot is unmarked | |
200 | as being a spill slot and if final address comes out to be based | |
48e1416a | 201 | off the frame pointer, the global algorithm handles this slot. |
3072d30e | 202 | |
203 | c) For any pass that may prespill, there is currently no | |
204 | mechanism to tell the dse pass that the slot being used has the | |
205 | special properties that reload uses. It may be that all that is | |
bef304b8 | 206 | required is to have those passes make the same calls that reload |
3072d30e | 207 | does, assuming that the alias sets can be manipulated in the same |
208 | way. */ | |
209 | ||
210 | /* There are limits to the size of constant offsets we model for the | |
211 | global problem. There are certainly test cases, that exceed this | |
212 | limit, however, it is unlikely that there are important programs | |
213 | that really have constant offsets this size. */ | |
214 | #define MAX_OFFSET (64 * 1024) | |
215 | ||
4fb07d00 | 216 | /* Obstack for the DSE dataflow bitmaps. We don't want to put these |
217 | on the default obstack because these bitmaps can grow quite large | |
218 | (~2GB for the small (!) test case of PR54146) and we'll hold on to | |
219 | all that memory until the end of the compiler run. | |
220 | As a bonus, delete_tree_live_info can destroy all the bitmaps by just | |
221 | releasing the whole obstack. */ | |
222 | static bitmap_obstack dse_bitmap_obstack; | |
223 | ||
224 | /* Obstack for other data. As for above: Kinda nice to be able to | |
225 | throw it all away at the end in one big sweep. */ | |
226 | static struct obstack dse_obstack; | |
227 | ||
228 | /* Scratch bitmap for cselib's cselib_expand_value_rtx. */ | |
3072d30e | 229 | static bitmap scratch = NULL; |
4fb07d00 | 230 | |
55c5ac9f | 231 | struct insn_info_type; |
3072d30e | 232 | |
233 | /* This structure holds information about a candidate store. */ | |
48e1416a | 234 | struct store_info |
3072d30e | 235 | { |
236 | ||
237 | /* False means this is a clobber. */ | |
238 | bool is_set; | |
239 | ||
aa140b76 | 240 | /* False if a single HOST_WIDE_INT bitmap is used for positions_needed. */ |
241 | bool is_large; | |
242 | ||
3072d30e | 243 | /* The id of the mem group of the base address. If rtx_varies_p is |
244 | true, this is -1. Otherwise, it is the index into the group | |
245 | table. */ | |
246 | int group_id; | |
48e1416a | 247 | |
3072d30e | 248 | /* This is the cselib value. */ |
249 | cselib_val *cse_base; | |
250 | ||
251 | /* This canonized mem. */ | |
252 | rtx mem; | |
253 | ||
82d2c88b | 254 | /* Canonized MEM address for use by canon_true_dependence. */ |
3072d30e | 255 | rtx mem_addr; |
256 | ||
257 | /* If this is non-zero, it is the alias set of a spill location. */ | |
32c2fdea | 258 | alias_set_type alias_set; |
3072d30e | 259 | |
260 | /* The offset of the first and byte before the last byte associated | |
261 | with the operation. */ | |
aa140b76 | 262 | HOST_WIDE_INT begin, end; |
263 | ||
264 | union | |
265 | { | |
266 | /* A bitmask as wide as the number of bytes in the word that | |
267 | contains a 1 if the byte may be needed. The store is unused if | |
268 | all of the bits are 0. This is used if IS_LARGE is false. */ | |
269 | unsigned HOST_WIDE_INT small_bitmask; | |
270 | ||
271 | struct | |
272 | { | |
273 | /* A bitmap with one bit per byte. Cleared bit means the position | |
274 | is needed. Used if IS_LARGE is false. */ | |
843bd2fa | 275 | bitmap bmap; |
3072d30e | 276 | |
aa140b76 | 277 | /* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is |
278 | equal to END - BEGIN, the whole store is unused. */ | |
279 | int count; | |
280 | } large; | |
281 | } positions_needed; | |
3072d30e | 282 | |
283 | /* The next store info for this insn. */ | |
284 | struct store_info *next; | |
285 | ||
286 | /* The right hand side of the store. This is used if there is a | |
287 | subsequent reload of the mems address somewhere later in the | |
288 | basic block. */ | |
aa140b76 | 289 | rtx rhs; |
290 | ||
291 | /* If rhs is or holds a constant, this contains that constant, | |
292 | otherwise NULL. */ | |
293 | rtx const_rhs; | |
294 | ||
295 | /* Set if this store stores the same constant value as REDUNDANT_REASON | |
296 | insn stored. These aren't eliminated early, because doing that | |
297 | might prevent the earlier larger store to be eliminated. */ | |
55c5ac9f | 298 | struct insn_info_type *redundant_reason; |
3072d30e | 299 | }; |
300 | ||
4e43e20a | 301 | /* Return a bitmask with the first N low bits set. */ |
302 | ||
303 | static unsigned HOST_WIDE_INT | |
304 | lowpart_bitmask (int n) | |
305 | { | |
306 | unsigned HOST_WIDE_INT mask = ~(unsigned HOST_WIDE_INT) 0; | |
307 | return mask >> (HOST_BITS_PER_WIDE_INT - n); | |
308 | } | |
309 | ||
3072d30e | 310 | typedef struct store_info *store_info_t; |
e16712b1 | 311 | static object_allocator<store_info> cse_store_info_pool ("cse_store_info_pool", |
55c5ac9f | 312 | 100); |
313 | ||
e16712b1 | 314 | static object_allocator<store_info> rtx_store_info_pool ("rtx_store_info_pool", |
55c5ac9f | 315 | 100); |
3072d30e | 316 | |
317 | /* This structure holds information about a load. These are only | |
318 | built for rtx bases. */ | |
55c5ac9f | 319 | struct read_info_type |
3072d30e | 320 | { |
321 | /* The id of the mem group of the base address. */ | |
322 | int group_id; | |
323 | ||
324 | /* If this is non-zero, it is the alias set of a spill location. */ | |
32c2fdea | 325 | alias_set_type alias_set; |
3072d30e | 326 | |
327 | /* The offset of the first and byte after the last byte associated | |
328 | with the operation. If begin == end == 0, the read did not have | |
329 | a constant offset. */ | |
330 | int begin, end; | |
331 | ||
332 | /* The mem being read. */ | |
333 | rtx mem; | |
334 | ||
335 | /* The next read_info for this insn. */ | |
55c5ac9f | 336 | struct read_info_type *next; |
3072d30e | 337 | }; |
55c5ac9f | 338 | typedef struct read_info_type *read_info_t; |
3072d30e | 339 | |
e16712b1 | 340 | static object_allocator<read_info_type> read_info_type_pool |
341 | ("read_info_pool", 100); | |
3072d30e | 342 | |
343 | /* One of these records is created for each insn. */ | |
344 | ||
55c5ac9f | 345 | struct insn_info_type |
3072d30e | 346 | { |
347 | /* Set true if the insn contains a store but the insn itself cannot | |
348 | be deleted. This is set if the insn is a parallel and there is | |
349 | more than one non dead output or if the insn is in some way | |
350 | volatile. */ | |
351 | bool cannot_delete; | |
352 | ||
353 | /* This field is only used by the global algorithm. It is set true | |
354 | if the insn contains any read of mem except for a (1). This is | |
355 | also set if the insn is a call or has a clobber mem. If the insn | |
356 | contains a wild read, the use_rec will be null. */ | |
357 | bool wild_read; | |
358 | ||
b4a708fb | 359 | /* This is true only for CALL instructions which could potentially read |
360 | any non-frame memory location. This field is used by the global | |
361 | algorithm. */ | |
362 | bool non_frame_wild_read; | |
363 | ||
17e1318c | 364 | /* This field is only used for the processing of const functions. |
365 | These functions cannot read memory, but they can read the stack | |
16bf64db | 366 | because that is where they may get their parms. We need to be |
367 | this conservative because, like the store motion pass, we don't | |
368 | consider CALL_INSN_FUNCTION_USAGE when processing call insns. | |
369 | Moreover, we need to distinguish two cases: | |
370 | 1. Before reload (register elimination), the stores related to | |
371 | outgoing arguments are stack pointer based and thus deemed | |
372 | of non-constant base in this pass. This requires special | |
373 | handling but also means that the frame pointer based stores | |
374 | need not be killed upon encountering a const function call. | |
375 | 2. After reload, the stores related to outgoing arguments can be | |
376 | either stack pointer or hard frame pointer based. This means | |
377 | that we have no other choice than also killing all the frame | |
378 | pointer based stores upon encountering a const function call. | |
17853422 | 379 | This field is set after reload for const function calls and before |
380 | reload for const tail function calls on targets where arg pointer | |
381 | is the frame pointer. Having this set is less severe than a wild | |
382 | read, it just means that all the frame related stores are killed | |
383 | rather than all the stores. */ | |
16bf64db | 384 | bool frame_read; |
385 | ||
386 | /* This field is only used for the processing of const functions. | |
387 | It is set if the insn may contain a stack pointer based store. */ | |
17e1318c | 388 | bool stack_pointer_based; |
3072d30e | 389 | |
390 | /* This is true if any of the sets within the store contains a | |
391 | cselib base. Such stores can only be deleted by the local | |
392 | algorithm. */ | |
393 | bool contains_cselib_groups; | |
394 | ||
395 | /* The insn. */ | |
ebabb7a3 | 396 | rtx_insn *insn; |
3072d30e | 397 | |
398 | /* The list of mem sets or mem clobbers that are contained in this | |
399 | insn. If the insn is deletable, it contains only one mem set. | |
400 | But it could also contain clobbers. Insns that contain more than | |
401 | one mem set are not deletable, but each of those mems are here in | |
6dfdc153 | 402 | order to provide info to delete other insns. */ |
3072d30e | 403 | store_info_t store_rec; |
404 | ||
405 | /* The linked list of mem uses in this insn. Only the reads from | |
406 | rtx bases are listed here. The reads to cselib bases are | |
407 | completely processed during the first scan and so are never | |
408 | created. */ | |
409 | read_info_t read_rec; | |
410 | ||
5a9ecd4a | 411 | /* The live fixed registers. We assume only fixed registers can |
412 | cause trouble by being clobbered from an expanded pattern; | |
413 | storing only the live fixed registers (rather than all registers) | |
414 | means less memory needs to be allocated / copied for the individual | |
415 | stores. */ | |
416 | regset fixed_regs_live; | |
417 | ||
3072d30e | 418 | /* The prev insn in the basic block. */ |
55c5ac9f | 419 | struct insn_info_type * prev_insn; |
3072d30e | 420 | |
421 | /* The linked list of insns that are in consideration for removal in | |
9d75589a | 422 | the forwards pass through the basic block. This pointer may be |
3072d30e | 423 | trash as it is not cleared when a wild read occurs. The only |
f0b5f617 | 424 | time it is guaranteed to be correct is when the traversal starts |
3072d30e | 425 | at active_local_stores. */ |
55c5ac9f | 426 | struct insn_info_type * next_local_store; |
3072d30e | 427 | }; |
55c5ac9f | 428 | typedef struct insn_info_type *insn_info_t; |
3072d30e | 429 | |
e16712b1 | 430 | static object_allocator<insn_info_type> insn_info_type_pool |
431 | ("insn_info_pool", 100); | |
3072d30e | 432 | |
433 | /* The linked list of stores that are under consideration in this | |
48e1416a | 434 | basic block. */ |
3072d30e | 435 | static insn_info_t active_local_stores; |
1242bee6 | 436 | static int active_local_stores_len; |
3072d30e | 437 | |
55c5ac9f | 438 | struct dse_bb_info_type |
3072d30e | 439 | { |
3072d30e | 440 | /* Pointer to the insn info for the last insn in the block. These |
441 | are linked so this is how all of the insns are reached. During | |
442 | scanning this is the current insn being scanned. */ | |
443 | insn_info_t last_insn; | |
444 | ||
445 | /* The info for the global dataflow problem. */ | |
446 | ||
447 | ||
448 | /* This is set if the transfer function should and in the wild_read | |
449 | bitmap before applying the kill and gen sets. That vector knocks | |
450 | out most of the bits in the bitmap and thus speeds up the | |
451 | operations. */ | |
452 | bool apply_wild_read; | |
453 | ||
a1b0a968 | 454 | /* The following 4 bitvectors hold information about which positions |
455 | of which stores are live or dead. They are indexed by | |
456 | get_bitmap_index. */ | |
457 | ||
3072d30e | 458 | /* The set of store positions that exist in this block before a wild read. */ |
459 | bitmap gen; | |
48e1416a | 460 | |
3072d30e | 461 | /* The set of load positions that exist in this block above the |
462 | same position of a store. */ | |
463 | bitmap kill; | |
464 | ||
465 | /* The set of stores that reach the top of the block without being | |
466 | killed by a read. | |
467 | ||
468 | Do not represent the in if it is all ones. Note that this is | |
469 | what the bitvector should logically be initialized to for a set | |
470 | intersection problem. However, like the kill set, this is too | |
471 | expensive. So initially, the in set will only be created for the | |
472 | exit block and any block that contains a wild read. */ | |
473 | bitmap in; | |
474 | ||
475 | /* The set of stores that reach the bottom of the block from it's | |
476 | successors. | |
477 | ||
478 | Do not represent the in if it is all ones. Note that this is | |
479 | what the bitvector should logically be initialized to for a set | |
480 | intersection problem. However, like the kill and in set, this is | |
481 | too expensive. So what is done is that the confluence operator | |
482 | just initializes the vector from one of the out sets of the | |
483 | successors of the block. */ | |
484 | bitmap out; | |
a1b0a968 | 485 | |
486 | /* The following bitvector is indexed by the reg number. It | |
487 | contains the set of regs that are live at the current instruction | |
488 | being processed. While it contains info for all of the | |
5a9ecd4a | 489 | registers, only the hard registers are actually examined. It is used |
490 | to assure that shift and/or add sequences that are inserted do not | |
9d75589a | 491 | accidentally clobber live hard regs. */ |
a1b0a968 | 492 | bitmap regs_live; |
3072d30e | 493 | }; |
494 | ||
55c5ac9f | 495 | typedef struct dse_bb_info_type *bb_info_t; |
e16712b1 | 496 | |
497 | static object_allocator<dse_bb_info_type> dse_bb_info_type_pool | |
498 | ("bb_info_pool", 100); | |
3072d30e | 499 | |
500 | /* Table to hold all bb_infos. */ | |
501 | static bb_info_t *bb_table; | |
502 | ||
503 | /* There is a group_info for each rtx base that is used to reference | |
504 | memory. There are also not many of the rtx bases because they are | |
505 | very limited in scope. */ | |
506 | ||
48e1416a | 507 | struct group_info |
3072d30e | 508 | { |
509 | /* The actual base of the address. */ | |
510 | rtx rtx_base; | |
511 | ||
512 | /* The sequential id of the base. This allows us to have a | |
513 | canonical ordering of these that is not based on addresses. */ | |
514 | int id; | |
515 | ||
0ac758f7 | 516 | /* True if there are any positions that are to be processed |
517 | globally. */ | |
518 | bool process_globally; | |
519 | ||
520 | /* True if the base of this group is either the frame_pointer or | |
521 | hard_frame_pointer. */ | |
522 | bool frame_related; | |
523 | ||
ec410bf1 | 524 | /* A mem wrapped around the base pointer for the group in order to do |
525 | read dependency. It must be given BLKmode in order to encompass all | |
526 | the possible offsets from the base. */ | |
3072d30e | 527 | rtx base_mem; |
48e1416a | 528 | |
82d2c88b | 529 | /* Canonized version of base_mem's address. */ |
530 | rtx canon_base_addr; | |
3072d30e | 531 | |
532 | /* These two sets of two bitmaps are used to keep track of how many | |
6dfdc153 | 533 | stores are actually referencing that position from this base. We |
3072d30e | 534 | only do this for rtx bases as this will be used to assign |
6dfdc153 | 535 | positions in the bitmaps for the global problem. Bit N is set in |
3072d30e | 536 | store1 on the first store for offset N. Bit N is set in store2 |
537 | for the second store to offset N. This is all we need since we | |
538 | only care about offsets that have two or more stores for them. | |
539 | ||
540 | The "_n" suffix is for offsets less than 0 and the "_p" suffix is | |
541 | for 0 and greater offsets. | |
542 | ||
543 | There is one special case here, for stores into the stack frame, | |
544 | we will or store1 into store2 before deciding which stores look | |
545 | at globally. This is because stores to the stack frame that have | |
546 | no other reads before the end of the function can also be | |
547 | deleted. */ | |
548 | bitmap store1_n, store1_p, store2_n, store2_p; | |
549 | ||
b4a708fb | 550 | /* These bitmaps keep track of offsets in this group escape this function. |
551 | An offset escapes if it corresponds to a named variable whose | |
552 | addressable flag is set. */ | |
553 | bitmap escaped_n, escaped_p; | |
554 | ||
6dfdc153 | 555 | /* The positions in this bitmap have the same assignments as the in, |
3072d30e | 556 | out, gen and kill bitmaps. This bitmap is all zeros except for |
6dfdc153 | 557 | the positions that are occupied by stores for this group. */ |
3072d30e | 558 | bitmap group_kill; |
559 | ||
3072d30e | 560 | /* The offset_map is used to map the offsets from this base into |
6dfdc153 | 561 | positions in the global bitmaps. It is only created after all of |
3072d30e | 562 | the all of stores have been scanned and we know which ones we |
563 | care about. */ | |
48e1416a | 564 | int *offset_map_n, *offset_map_p; |
565 | int offset_map_size_n, offset_map_size_p; | |
3072d30e | 566 | }; |
567 | typedef struct group_info *group_info_t; | |
c1fdef8e | 568 | typedef const struct group_info *const_group_info_t; |
55c5ac9f | 569 | |
e16712b1 | 570 | static object_allocator<group_info> group_info_pool |
571 | ("rtx_group_info_pool", 100); | |
3072d30e | 572 | |
3072d30e | 573 | /* Index into the rtx_group_vec. */ |
574 | static int rtx_group_next_id; | |
575 | ||
3072d30e | 576 | |
f1f41a6c | 577 | static vec<group_info_t> rtx_group_vec; |
3072d30e | 578 | |
579 | ||
580 | /* This structure holds the set of changes that are being deferred | |
581 | when removing read operation. See replace_read. */ | |
48e1416a | 582 | struct deferred_change |
3072d30e | 583 | { |
584 | ||
585 | /* The mem that is being replaced. */ | |
586 | rtx *loc; | |
587 | ||
588 | /* The reg it is being replaced with. */ | |
589 | rtx reg; | |
590 | ||
591 | struct deferred_change *next; | |
592 | }; | |
593 | ||
594 | typedef struct deferred_change *deferred_change_t; | |
55c5ac9f | 595 | |
e16712b1 | 596 | static object_allocator<deferred_change> deferred_change_pool |
55c5ac9f | 597 | ("deferred_change_pool", 10); |
3072d30e | 598 | |
599 | static deferred_change_t deferred_change_list = NULL; | |
600 | ||
3072d30e | 601 | /* The group that holds all of the clear_alias_sets. */ |
602 | static group_info_t clear_alias_group; | |
603 | ||
604 | /* The modes of the clear_alias_sets. */ | |
605 | static htab_t clear_alias_mode_table; | |
606 | ||
607 | /* Hash table element to look up the mode for an alias set. */ | |
608 | struct clear_alias_mode_holder | |
609 | { | |
32c2fdea | 610 | alias_set_type alias_set; |
3754d046 | 611 | machine_mode mode; |
3072d30e | 612 | }; |
613 | ||
18d50ae6 | 614 | /* This is true except if cfun->stdarg -- i.e. we cannot do |
ff3ae375 | 615 | this for vararg functions because they play games with the frame. */ |
3072d30e | 616 | static bool stores_off_frame_dead_at_return; |
617 | ||
618 | /* Counter for stats. */ | |
48e1416a | 619 | static int globally_deleted; |
620 | static int locally_deleted; | |
621 | static int spill_deleted; | |
622 | ||
3072d30e | 623 | static bitmap all_blocks; |
624 | ||
b4a708fb | 625 | /* Locations that are killed by calls in the global phase. */ |
626 | static bitmap kill_on_calls; | |
627 | ||
3072d30e | 628 | /* The number of bits used in the global bitmaps. */ |
629 | static unsigned int current_position; | |
3072d30e | 630 | \f |
631 | /*---------------------------------------------------------------------------- | |
632 | Zeroth step. | |
633 | ||
48e1416a | 634 | Initialization. |
3072d30e | 635 | ----------------------------------------------------------------------------*/ |
636 | ||
3072d30e | 637 | |
638 | /* Find the entry associated with ALIAS_SET. */ | |
639 | ||
640 | static struct clear_alias_mode_holder * | |
32c2fdea | 641 | clear_alias_set_lookup (alias_set_type alias_set) |
3072d30e | 642 | { |
643 | struct clear_alias_mode_holder tmp_holder; | |
644 | void **slot; | |
48e1416a | 645 | |
3072d30e | 646 | tmp_holder.alias_set = alias_set; |
647 | slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, NO_INSERT); | |
648 | gcc_assert (*slot); | |
48e1416a | 649 | |
364c0c59 | 650 | return (struct clear_alias_mode_holder *) *slot; |
3072d30e | 651 | } |
652 | ||
653 | ||
654 | /* Hashtable callbacks for maintaining the "bases" field of | |
655 | store_group_info, given that the addresses are function invariants. */ | |
656 | ||
770ff93b | 657 | struct invariant_group_base_hasher : nofree_ptr_hash <group_info> |
d1455aa3 | 658 | { |
9969c043 | 659 | static inline hashval_t hash (const group_info *); |
660 | static inline bool equal (const group_info *, const group_info *); | |
d1455aa3 | 661 | }; |
662 | ||
663 | inline bool | |
9969c043 | 664 | invariant_group_base_hasher::equal (const group_info *gi1, |
665 | const group_info *gi2) | |
3072d30e | 666 | { |
3072d30e | 667 | return rtx_equal_p (gi1->rtx_base, gi2->rtx_base); |
668 | } | |
669 | ||
d1455aa3 | 670 | inline hashval_t |
9969c043 | 671 | invariant_group_base_hasher::hash (const group_info *gi) |
3072d30e | 672 | { |
3072d30e | 673 | int do_not_record; |
674 | return hash_rtx (gi->rtx_base, Pmode, &do_not_record, NULL, false); | |
675 | } | |
676 | ||
d1455aa3 | 677 | /* Tables of group_info structures, hashed by base value. */ |
c1f445d2 | 678 | static hash_table<invariant_group_base_hasher> *rtx_group_table; |
d1455aa3 | 679 | |
3072d30e | 680 | |
681 | /* Get the GROUP for BASE. Add a new group if it is not there. */ | |
682 | ||
683 | static group_info_t | |
684 | get_group_info (rtx base) | |
685 | { | |
48e1416a | 686 | struct group_info tmp_gi; |
687 | group_info_t gi; | |
d1455aa3 | 688 | group_info **slot; |
3072d30e | 689 | |
690 | if (base) | |
691 | { | |
692 | /* Find the store_base_info structure for BASE, creating a new one | |
693 | if necessary. */ | |
694 | tmp_gi.rtx_base = base; | |
c1f445d2 | 695 | slot = rtx_group_table->find_slot (&tmp_gi, INSERT); |
3072d30e | 696 | gi = (group_info_t) *slot; |
697 | } | |
698 | else | |
699 | { | |
700 | if (!clear_alias_group) | |
701 | { | |
e16712b1 | 702 | clear_alias_group = gi = group_info_pool.allocate (); |
3072d30e | 703 | memset (gi, 0, sizeof (struct group_info)); |
704 | gi->id = rtx_group_next_id++; | |
4fb07d00 | 705 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
706 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
707 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
708 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
709 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
710 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
711 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
3072d30e | 712 | gi->process_globally = false; |
713 | gi->offset_map_size_n = 0; | |
714 | gi->offset_map_size_p = 0; | |
715 | gi->offset_map_n = NULL; | |
716 | gi->offset_map_p = NULL; | |
f1f41a6c | 717 | rtx_group_vec.safe_push (gi); |
3072d30e | 718 | } |
719 | return clear_alias_group; | |
720 | } | |
721 | ||
722 | if (gi == NULL) | |
723 | { | |
e16712b1 | 724 | *slot = gi = group_info_pool.allocate (); |
3072d30e | 725 | gi->rtx_base = base; |
726 | gi->id = rtx_group_next_id++; | |
ec410bf1 | 727 | gi->base_mem = gen_rtx_MEM (BLKmode, base); |
82d2c88b | 728 | gi->canon_base_addr = canon_rtx (base); |
4fb07d00 | 729 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
730 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
731 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
732 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
733 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
734 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
735 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
3072d30e | 736 | gi->process_globally = false; |
48e1416a | 737 | gi->frame_related = |
3072d30e | 738 | (base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx); |
739 | gi->offset_map_size_n = 0; | |
740 | gi->offset_map_size_p = 0; | |
741 | gi->offset_map_n = NULL; | |
742 | gi->offset_map_p = NULL; | |
f1f41a6c | 743 | rtx_group_vec.safe_push (gi); |
3072d30e | 744 | } |
745 | ||
746 | return gi; | |
747 | } | |
748 | ||
749 | ||
750 | /* Initialization of data structures. */ | |
751 | ||
752 | static void | |
753 | dse_step0 (void) | |
754 | { | |
755 | locally_deleted = 0; | |
756 | globally_deleted = 0; | |
757 | spill_deleted = 0; | |
758 | ||
4fb07d00 | 759 | bitmap_obstack_initialize (&dse_bitmap_obstack); |
760 | gcc_obstack_init (&dse_obstack); | |
761 | ||
762 | scratch = BITMAP_ALLOC (®_obstack); | |
763 | kill_on_calls = BITMAP_ALLOC (&dse_bitmap_obstack); | |
3072d30e | 764 | |
3072d30e | 765 | |
c1f445d2 | 766 | rtx_group_table = new hash_table<invariant_group_base_hasher> (11); |
3072d30e | 767 | |
fe672ac0 | 768 | bb_table = XNEWVEC (bb_info_t, last_basic_block_for_fn (cfun)); |
3072d30e | 769 | rtx_group_next_id = 0; |
770 | ||
18d50ae6 | 771 | stores_off_frame_dead_at_return = !cfun->stdarg; |
3072d30e | 772 | |
773 | init_alias_analysis (); | |
48e1416a | 774 | |
e85eaec5 | 775 | clear_alias_group = NULL; |
3072d30e | 776 | } |
777 | ||
778 | ||
779 | \f | |
780 | /*---------------------------------------------------------------------------- | |
781 | First step. | |
782 | ||
783 | Scan all of the insns. Any random ordering of the blocks is fine. | |
bef304b8 | 784 | Each block is scanned in forward order to accommodate cselib which |
3072d30e | 785 | is used to remove stores with non-constant bases. |
786 | ----------------------------------------------------------------------------*/ | |
787 | ||
788 | /* Delete all of the store_info recs from INSN_INFO. */ | |
789 | ||
48e1416a | 790 | static void |
3072d30e | 791 | free_store_info (insn_info_t insn_info) |
792 | { | |
793 | store_info_t store_info = insn_info->store_rec; | |
794 | while (store_info) | |
795 | { | |
796 | store_info_t next = store_info->next; | |
aa140b76 | 797 | if (store_info->is_large) |
843bd2fa | 798 | BITMAP_FREE (store_info->positions_needed.large.bmap); |
3072d30e | 799 | if (store_info->cse_base) |
55c5ac9f | 800 | cse_store_info_pool.remove (store_info); |
3072d30e | 801 | else |
55c5ac9f | 802 | rtx_store_info_pool.remove (store_info); |
3072d30e | 803 | store_info = next; |
804 | } | |
805 | ||
806 | insn_info->cannot_delete = true; | |
807 | insn_info->contains_cselib_groups = false; | |
808 | insn_info->store_rec = NULL; | |
809 | } | |
810 | ||
5a9ecd4a | 811 | typedef struct |
812 | { | |
4cd001d5 | 813 | rtx_insn *first, *current; |
5a9ecd4a | 814 | regset fixed_regs_live; |
815 | bool failure; | |
816 | } note_add_store_info; | |
817 | ||
818 | /* Callback for emit_inc_dec_insn_before via note_stores. | |
819 | Check if a register is clobbered which is live afterwards. */ | |
820 | ||
821 | static void | |
822 | note_add_store (rtx loc, const_rtx expr ATTRIBUTE_UNUSED, void *data) | |
823 | { | |
4cd001d5 | 824 | rtx_insn *insn; |
5a9ecd4a | 825 | note_add_store_info *info = (note_add_store_info *) data; |
5a9ecd4a | 826 | |
827 | if (!REG_P (loc)) | |
828 | return; | |
829 | ||
830 | /* If this register is referenced by the current or an earlier insn, | |
831 | that's OK. E.g. this applies to the register that is being incremented | |
832 | with this addition. */ | |
833 | for (insn = info->first; | |
834 | insn != NEXT_INSN (info->current); | |
835 | insn = NEXT_INSN (insn)) | |
836 | if (reg_referenced_p (loc, PATTERN (insn))) | |
837 | return; | |
838 | ||
839 | /* If we come here, we have a clobber of a register that's only OK | |
840 | if that register is not live. If we don't have liveness information | |
841 | available, fail now. */ | |
842 | if (!info->fixed_regs_live) | |
843 | { | |
6a298741 | 844 | info->failure = true; |
5a9ecd4a | 845 | return; |
846 | } | |
847 | /* Now check if this is a live fixed register. */ | |
6a298741 | 848 | unsigned int end_regno = END_REGNO (loc); |
849 | for (unsigned int regno = REGNO (loc); regno < end_regno; ++regno) | |
850 | if (REGNO_REG_SET_P (info->fixed_regs_live, regno)) | |
851 | info->failure = true; | |
5a9ecd4a | 852 | } |
853 | ||
1f864115 | 854 | /* Callback for for_each_inc_dec that emits an INSN that sets DEST to |
855 | SRC + SRCOFF before insn ARG. */ | |
3072d30e | 856 | |
857 | static int | |
1f864115 | 858 | emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED, |
859 | rtx op ATTRIBUTE_UNUSED, | |
860 | rtx dest, rtx src, rtx srcoff, void *arg) | |
3072d30e | 861 | { |
5a9ecd4a | 862 | insn_info_t insn_info = (insn_info_t) arg; |
4cd001d5 | 863 | rtx_insn *insn = insn_info->insn, *new_insn, *cur; |
5a9ecd4a | 864 | note_add_store_info info; |
48e1416a | 865 | |
1f864115 | 866 | /* We can reuse all operands without copying, because we are about |
867 | to delete the insn that contained it. */ | |
5a9ecd4a | 868 | if (srcoff) |
a280a5da | 869 | { |
870 | start_sequence (); | |
871 | emit_insn (gen_add3_insn (dest, src, srcoff)); | |
872 | new_insn = get_insns (); | |
873 | end_sequence (); | |
874 | } | |
5a9ecd4a | 875 | else |
f9a00e9e | 876 | new_insn = gen_move_insn (dest, src); |
5a9ecd4a | 877 | info.first = new_insn; |
878 | info.fixed_regs_live = insn_info->fixed_regs_live; | |
879 | info.failure = false; | |
880 | for (cur = new_insn; cur; cur = NEXT_INSN (cur)) | |
881 | { | |
882 | info.current = cur; | |
883 | note_stores (PATTERN (cur), note_add_store, &info); | |
884 | } | |
3072d30e | 885 | |
5a9ecd4a | 886 | /* If a failure was flagged above, return 1 so that for_each_inc_dec will |
887 | return it immediately, communicating the failure to its caller. */ | |
888 | if (info.failure) | |
889 | return 1; | |
890 | ||
891 | emit_insn_before (new_insn, insn); | |
3072d30e | 892 | |
623ad592 | 893 | return 0; |
3072d30e | 894 | } |
895 | ||
5a9ecd4a | 896 | /* Before we delete INSN_INFO->INSN, make sure that the auto inc/dec, if it |
897 | is there, is split into a separate insn. | |
898 | Return true on success (or if there was nothing to do), false on failure. */ | |
3072d30e | 899 | |
5a9ecd4a | 900 | static bool |
901 | check_for_inc_dec_1 (insn_info_t insn_info) | |
3072d30e | 902 | { |
ebabb7a3 | 903 | rtx_insn *insn = insn_info->insn; |
3072d30e | 904 | rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
905 | if (note) | |
623ad592 | 906 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
907 | insn_info) == 0; | |
5a9ecd4a | 908 | return true; |
3072d30e | 909 | } |
910 | ||
911 | ||
5a9ecd4a | 912 | /* Entry point for postreload. If you work on reload_cse, or you need this |
913 | anywhere else, consider if you can provide register liveness information | |
914 | and add a parameter to this function so that it can be passed down in | |
915 | insn_info.fixed_regs_live. */ | |
916 | bool | |
ebabb7a3 | 917 | check_for_inc_dec (rtx_insn *insn) |
5a9ecd4a | 918 | { |
55c5ac9f | 919 | insn_info_type insn_info; |
5a9ecd4a | 920 | rtx note; |
921 | ||
922 | insn_info.insn = insn; | |
923 | insn_info.fixed_regs_live = NULL; | |
924 | note = find_reg_note (insn, REG_INC, NULL_RTX); | |
925 | if (note) | |
623ad592 | 926 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
927 | &insn_info) == 0; | |
5a9ecd4a | 928 | return true; |
929 | } | |
930 | ||
48e1416a | 931 | /* Delete the insn and free all of the fields inside INSN_INFO. */ |
3072d30e | 932 | |
933 | static void | |
934 | delete_dead_store_insn (insn_info_t insn_info) | |
935 | { | |
936 | read_info_t read_info; | |
937 | ||
938 | if (!dbg_cnt (dse)) | |
939 | return; | |
940 | ||
5a9ecd4a | 941 | if (!check_for_inc_dec_1 (insn_info)) |
942 | return; | |
1ca59310 | 943 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 944 | { |
48e1416a | 945 | fprintf (dump_file, "Locally deleting insn %d ", |
3072d30e | 946 | INSN_UID (insn_info->insn)); |
947 | if (insn_info->store_rec->alias_set) | |
48e1416a | 948 | fprintf (dump_file, "alias set %d\n", |
32c2fdea | 949 | (int) insn_info->store_rec->alias_set); |
3072d30e | 950 | else |
951 | fprintf (dump_file, "\n"); | |
952 | } | |
953 | ||
954 | free_store_info (insn_info); | |
955 | read_info = insn_info->read_rec; | |
48e1416a | 956 | |
3072d30e | 957 | while (read_info) |
958 | { | |
959 | read_info_t next = read_info->next; | |
e16712b1 | 960 | read_info_type_pool.remove (read_info); |
3072d30e | 961 | read_info = next; |
962 | } | |
963 | insn_info->read_rec = NULL; | |
964 | ||
965 | delete_insn (insn_info->insn); | |
966 | locally_deleted++; | |
967 | insn_info->insn = NULL; | |
968 | ||
969 | insn_info->wild_read = false; | |
970 | } | |
971 | ||
f7b5f694 | 972 | /* Return whether DECL, a local variable, can possibly escape the current |
973 | function scope. */ | |
974 | ||
975 | static bool | |
976 | local_variable_can_escape (tree decl) | |
977 | { | |
978 | if (TREE_ADDRESSABLE (decl)) | |
979 | return true; | |
980 | ||
981 | /* If this is a partitioned variable, we need to consider all the variables | |
982 | in the partition. This is necessary because a store into one of them can | |
983 | be replaced with a store into another and this may not change the outcome | |
984 | of the escape analysis. */ | |
985 | if (cfun->gimple_df->decls_to_pointers != NULL) | |
986 | { | |
5f8841a5 | 987 | tree *namep = cfun->gimple_df->decls_to_pointers->get (decl); |
f7b5f694 | 988 | if (namep) |
5f8841a5 | 989 | return TREE_ADDRESSABLE (*namep); |
f7b5f694 | 990 | } |
991 | ||
992 | return false; | |
993 | } | |
994 | ||
995 | /* Return whether EXPR can possibly escape the current function scope. */ | |
996 | ||
b4a708fb | 997 | static bool |
998 | can_escape (tree expr) | |
999 | { | |
1000 | tree base; | |
1001 | if (!expr) | |
1002 | return true; | |
1003 | base = get_base_address (expr); | |
1004 | if (DECL_P (base) | |
f7b5f694 | 1005 | && !may_be_aliased (base) |
1006 | && !(TREE_CODE (base) == VAR_DECL | |
1007 | && !DECL_EXTERNAL (base) | |
1008 | && !TREE_STATIC (base) | |
1009 | && local_variable_can_escape (base))) | |
b4a708fb | 1010 | return false; |
1011 | return true; | |
1012 | } | |
3072d30e | 1013 | |
1014 | /* Set the store* bitmaps offset_map_size* fields in GROUP based on | |
1015 | OFFSET and WIDTH. */ | |
1016 | ||
1017 | static void | |
b4a708fb | 1018 | set_usage_bits (group_info_t group, HOST_WIDE_INT offset, HOST_WIDE_INT width, |
1019 | tree expr) | |
3072d30e | 1020 | { |
1021 | HOST_WIDE_INT i; | |
b4a708fb | 1022 | bool expr_escapes = can_escape (expr); |
aa140b76 | 1023 | if (offset > -MAX_OFFSET && offset + width < MAX_OFFSET) |
3072d30e | 1024 | for (i=offset; i<offset+width; i++) |
1025 | { | |
1026 | bitmap store1; | |
1027 | bitmap store2; | |
b4a708fb | 1028 | bitmap escaped; |
3072d30e | 1029 | int ai; |
1030 | if (i < 0) | |
1031 | { | |
1032 | store1 = group->store1_n; | |
1033 | store2 = group->store2_n; | |
b4a708fb | 1034 | escaped = group->escaped_n; |
3072d30e | 1035 | ai = -i; |
1036 | } | |
1037 | else | |
1038 | { | |
1039 | store1 = group->store1_p; | |
1040 | store2 = group->store2_p; | |
b4a708fb | 1041 | escaped = group->escaped_p; |
3072d30e | 1042 | ai = i; |
1043 | } | |
48e1416a | 1044 | |
6ef9bbe0 | 1045 | if (!bitmap_set_bit (store1, ai)) |
3072d30e | 1046 | bitmap_set_bit (store2, ai); |
48e1416a | 1047 | else |
3072d30e | 1048 | { |
3072d30e | 1049 | if (i < 0) |
1050 | { | |
1051 | if (group->offset_map_size_n < ai) | |
1052 | group->offset_map_size_n = ai; | |
1053 | } | |
1054 | else | |
1055 | { | |
1056 | if (group->offset_map_size_p < ai) | |
1057 | group->offset_map_size_p = ai; | |
1058 | } | |
1059 | } | |
b4a708fb | 1060 | if (expr_escapes) |
1061 | bitmap_set_bit (escaped, ai); | |
3072d30e | 1062 | } |
1063 | } | |
1064 | ||
b4a708fb | 1065 | static void |
1066 | reset_active_stores (void) | |
1067 | { | |
1068 | active_local_stores = NULL; | |
1069 | active_local_stores_len = 0; | |
1070 | } | |
3072d30e | 1071 | |
b4a708fb | 1072 | /* Free all READ_REC of the LAST_INSN of BB_INFO. */ |
3072d30e | 1073 | |
1074 | static void | |
b4a708fb | 1075 | free_read_records (bb_info_t bb_info) |
3072d30e | 1076 | { |
1077 | insn_info_t insn_info = bb_info->last_insn; | |
1078 | read_info_t *ptr = &insn_info->read_rec; | |
3072d30e | 1079 | while (*ptr) |
1080 | { | |
1081 | read_info_t next = (*ptr)->next; | |
32c2fdea | 1082 | if ((*ptr)->alias_set == 0) |
3072d30e | 1083 | { |
e16712b1 | 1084 | read_info_type_pool.remove (*ptr); |
3072d30e | 1085 | *ptr = next; |
b4a708fb | 1086 | } |
48e1416a | 1087 | else |
b4a708fb | 1088 | ptr = &(*ptr)->next; |
3072d30e | 1089 | } |
b4a708fb | 1090 | } |
1091 | ||
1092 | /* Set the BB_INFO so that the last insn is marked as a wild read. */ | |
1093 | ||
1094 | static void | |
1095 | add_wild_read (bb_info_t bb_info) | |
1096 | { | |
1097 | insn_info_t insn_info = bb_info->last_insn; | |
3072d30e | 1098 | insn_info->wild_read = true; |
b4a708fb | 1099 | free_read_records (bb_info); |
1100 | reset_active_stores (); | |
3072d30e | 1101 | } |
1102 | ||
b4a708fb | 1103 | /* Set the BB_INFO so that the last insn is marked as a wild read of |
1104 | non-frame locations. */ | |
1105 | ||
1106 | static void | |
1107 | add_non_frame_wild_read (bb_info_t bb_info) | |
1108 | { | |
1109 | insn_info_t insn_info = bb_info->last_insn; | |
1110 | insn_info->non_frame_wild_read = true; | |
1111 | free_read_records (bb_info); | |
1112 | reset_active_stores (); | |
1113 | } | |
3072d30e | 1114 | |
17e1318c | 1115 | /* Return true if X is a constant or one of the registers that behave |
1116 | as a constant over the life of a function. This is equivalent to | |
1117 | !rtx_varies_p for memory addresses. */ | |
3072d30e | 1118 | |
1119 | static bool | |
1120 | const_or_frame_p (rtx x) | |
1121 | { | |
0349edce | 1122 | if (CONSTANT_P (x)) |
1123 | return true; | |
1124 | ||
1125 | if (GET_CODE (x) == REG) | |
3072d30e | 1126 | { |
3072d30e | 1127 | /* Note that we have to test for the actual rtx used for the frame |
1128 | and arg pointers and not just the register number in case we have | |
1129 | eliminated the frame and/or arg pointer and are using it | |
1130 | for pseudos. */ | |
1131 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx | |
1132 | /* The arg pointer varies if it is not a fixed register. */ | |
1133 | || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
1134 | || x == pic_offset_table_rtx) | |
1135 | return true; | |
1136 | return false; | |
3072d30e | 1137 | } |
55c5ac9f | 1138 | |
0349edce | 1139 | return false; |
3072d30e | 1140 | } |
1141 | ||
48e1416a | 1142 | /* Take all reasonable action to put the address of MEM into the form |
1143 | that we can do analysis on. | |
3072d30e | 1144 | |
1145 | The gold standard is to get the address into the form: address + | |
1146 | OFFSET where address is something that rtx_varies_p considers a | |
1147 | constant. When we can get the address in this form, we can do | |
1148 | global analysis on it. Note that for constant bases, address is | |
1149 | not actually returned, only the group_id. The address can be | |
1150 | obtained from that. | |
1151 | ||
1152 | If that fails, we try cselib to get a value we can at least use | |
48e1416a | 1153 | locally. If that fails we return false. |
1154 | ||
3072d30e | 1155 | The GROUP_ID is set to -1 for cselib bases and the index of the |
1156 | group for non_varying bases. | |
1157 | ||
1158 | FOR_READ is true if this is a mem read and false if not. */ | |
1159 | ||
1160 | static bool | |
1161 | canon_address (rtx mem, | |
32c2fdea | 1162 | alias_set_type *alias_set_out, |
3072d30e | 1163 | int *group_id, |
48e1416a | 1164 | HOST_WIDE_INT *offset, |
3072d30e | 1165 | cselib_val **base) |
1166 | { | |
3754d046 | 1167 | machine_mode address_mode = get_address_mode (mem); |
3072d30e | 1168 | rtx mem_address = XEXP (mem, 0); |
1169 | rtx expanded_address, address; | |
627540ce | 1170 | int expanded; |
1171 | ||
3072d30e | 1172 | *alias_set_out = 0; |
1173 | ||
1f864115 | 1174 | cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem)); |
3072d30e | 1175 | |
1ca59310 | 1176 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1177 | { |
1178 | fprintf (dump_file, " mem: "); | |
1179 | print_inline_rtx (dump_file, mem_address, 0); | |
1180 | fprintf (dump_file, "\n"); | |
1181 | } | |
1182 | ||
627540ce | 1183 | /* First see if just canon_rtx (mem_address) is const or frame, |
1184 | if not, try cselib_expand_value_rtx and call canon_rtx on that. */ | |
1185 | address = NULL_RTX; | |
1186 | for (expanded = 0; expanded < 2; expanded++) | |
1187 | { | |
1188 | if (expanded) | |
1189 | { | |
1190 | /* Use cselib to replace all of the reg references with the full | |
48e1416a | 1191 | expression. This will take care of the case where we have |
3072d30e | 1192 | |
627540ce | 1193 | r_x = base + offset; |
1194 | val = *r_x; | |
48e1416a | 1195 | |
1196 | by making it into | |
3072d30e | 1197 | |
627540ce | 1198 | val = *(base + offset); */ |
3072d30e | 1199 | |
627540ce | 1200 | expanded_address = cselib_expand_value_rtx (mem_address, |
1201 | scratch, 5); | |
3072d30e | 1202 | |
627540ce | 1203 | /* If this fails, just go with the address from first |
1204 | iteration. */ | |
1205 | if (!expanded_address) | |
1206 | break; | |
1207 | } | |
1208 | else | |
1209 | expanded_address = mem_address; | |
3072d30e | 1210 | |
627540ce | 1211 | /* Split the address into canonical BASE + OFFSET terms. */ |
1212 | address = canon_rtx (expanded_address); | |
3072d30e | 1213 | |
627540ce | 1214 | *offset = 0; |
3072d30e | 1215 | |
1ca59310 | 1216 | if (dump_file && (dump_flags & TDF_DETAILS)) |
627540ce | 1217 | { |
1218 | if (expanded) | |
1219 | { | |
1220 | fprintf (dump_file, "\n after cselib_expand address: "); | |
1221 | print_inline_rtx (dump_file, expanded_address, 0); | |
1222 | fprintf (dump_file, "\n"); | |
1223 | } | |
3072d30e | 1224 | |
627540ce | 1225 | fprintf (dump_file, "\n after canon_rtx address: "); |
1226 | print_inline_rtx (dump_file, address, 0); | |
1227 | fprintf (dump_file, "\n"); | |
1228 | } | |
3072d30e | 1229 | |
627540ce | 1230 | if (GET_CODE (address) == CONST) |
1231 | address = XEXP (address, 0); | |
3072d30e | 1232 | |
627540ce | 1233 | if (GET_CODE (address) == PLUS |
1234 | && CONST_INT_P (XEXP (address, 1))) | |
1235 | { | |
1236 | *offset = INTVAL (XEXP (address, 1)); | |
1237 | address = XEXP (address, 0); | |
1238 | } | |
3072d30e | 1239 | |
bd1a81f7 | 1240 | if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem)) |
1241 | && const_or_frame_p (address)) | |
3072d30e | 1242 | { |
627540ce | 1243 | group_info_t group = get_group_info (address); |
1244 | ||
1ca59310 | 1245 | if (dump_file && (dump_flags & TDF_DETAILS)) |
627540ce | 1246 | fprintf (dump_file, " gid=%d offset=%d \n", |
1247 | group->id, (int)*offset); | |
1248 | *base = NULL; | |
1249 | *group_id = group->id; | |
1250 | return true; | |
3072d30e | 1251 | } |
627540ce | 1252 | } |
1253 | ||
1f864115 | 1254 | *base = cselib_lookup (address, address_mode, true, GET_MODE (mem)); |
627540ce | 1255 | *group_id = -1; |
1256 | ||
1257 | if (*base == NULL) | |
1258 | { | |
1ca59310 | 1259 | if (dump_file && (dump_flags & TDF_DETAILS)) |
627540ce | 1260 | fprintf (dump_file, " no cselib val - should be a wild read.\n"); |
1261 | return false; | |
3072d30e | 1262 | } |
1ca59310 | 1263 | if (dump_file && (dump_flags & TDF_DETAILS)) |
01df1184 | 1264 | fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n", |
1265 | (*base)->uid, (*base)->hash, (int)*offset); | |
3072d30e | 1266 | return true; |
1267 | } | |
1268 | ||
1269 | ||
1270 | /* Clear the rhs field from the active_local_stores array. */ | |
1271 | ||
1272 | static void | |
1273 | clear_rhs_from_active_local_stores (void) | |
1274 | { | |
1275 | insn_info_t ptr = active_local_stores; | |
1276 | ||
1277 | while (ptr) | |
1278 | { | |
1279 | store_info_t store_info = ptr->store_rec; | |
1280 | /* Skip the clobbers. */ | |
1281 | while (!store_info->is_set) | |
1282 | store_info = store_info->next; | |
1283 | ||
1284 | store_info->rhs = NULL; | |
aa140b76 | 1285 | store_info->const_rhs = NULL; |
3072d30e | 1286 | |
1287 | ptr = ptr->next_local_store; | |
1288 | } | |
1289 | } | |
1290 | ||
1291 | ||
aa140b76 | 1292 | /* Mark byte POS bytes from the beginning of store S_INFO as unneeded. */ |
1293 | ||
1294 | static inline void | |
1295 | set_position_unneeded (store_info_t s_info, int pos) | |
1296 | { | |
1297 | if (__builtin_expect (s_info->is_large, false)) | |
1298 | { | |
6ef9bbe0 | 1299 | if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos)) |
1300 | s_info->positions_needed.large.count++; | |
aa140b76 | 1301 | } |
1302 | else | |
1303 | s_info->positions_needed.small_bitmask | |
1304 | &= ~(((unsigned HOST_WIDE_INT) 1) << pos); | |
1305 | } | |
1306 | ||
1307 | /* Mark the whole store S_INFO as unneeded. */ | |
1308 | ||
1309 | static inline void | |
1310 | set_all_positions_unneeded (store_info_t s_info) | |
1311 | { | |
1312 | if (__builtin_expect (s_info->is_large, false)) | |
1313 | { | |
1314 | int pos, end = s_info->end - s_info->begin; | |
1315 | for (pos = 0; pos < end; pos++) | |
843bd2fa | 1316 | bitmap_set_bit (s_info->positions_needed.large.bmap, pos); |
aa140b76 | 1317 | s_info->positions_needed.large.count = end; |
1318 | } | |
1319 | else | |
1320 | s_info->positions_needed.small_bitmask = (unsigned HOST_WIDE_INT) 0; | |
1321 | } | |
1322 | ||
1323 | /* Return TRUE if any bytes from S_INFO store are needed. */ | |
1324 | ||
1325 | static inline bool | |
1326 | any_positions_needed_p (store_info_t s_info) | |
1327 | { | |
1328 | if (__builtin_expect (s_info->is_large, false)) | |
1329 | return (s_info->positions_needed.large.count | |
1330 | < s_info->end - s_info->begin); | |
1331 | else | |
1332 | return (s_info->positions_needed.small_bitmask | |
1333 | != (unsigned HOST_WIDE_INT) 0); | |
1334 | } | |
1335 | ||
1336 | /* Return TRUE if all bytes START through START+WIDTH-1 from S_INFO | |
1337 | store are needed. */ | |
1338 | ||
1339 | static inline bool | |
1340 | all_positions_needed_p (store_info_t s_info, int start, int width) | |
1341 | { | |
1342 | if (__builtin_expect (s_info->is_large, false)) | |
1343 | { | |
1344 | int end = start + width; | |
1345 | while (start < end) | |
843bd2fa | 1346 | if (bitmap_bit_p (s_info->positions_needed.large.bmap, start++)) |
aa140b76 | 1347 | return false; |
1348 | return true; | |
1349 | } | |
1350 | else | |
1351 | { | |
1352 | unsigned HOST_WIDE_INT mask = lowpart_bitmask (width) << start; | |
1353 | return (s_info->positions_needed.small_bitmask & mask) == mask; | |
1354 | } | |
1355 | } | |
1356 | ||
1357 | ||
3754d046 | 1358 | static rtx get_stored_val (store_info_t, machine_mode, HOST_WIDE_INT, |
aa140b76 | 1359 | HOST_WIDE_INT, basic_block, bool); |
1360 | ||
1361 | ||
3072d30e | 1362 | /* BODY is an instruction pattern that belongs to INSN. Return 1 if |
1363 | there is a candidate store, after adding it to the appropriate | |
1364 | local store group if so. */ | |
1365 | ||
1366 | static int | |
1367 | record_store (rtx body, bb_info_t bb_info) | |
1368 | { | |
82d2c88b | 1369 | rtx mem, rhs, const_rhs, mem_addr; |
3072d30e | 1370 | HOST_WIDE_INT offset = 0; |
1371 | HOST_WIDE_INT width = 0; | |
32c2fdea | 1372 | alias_set_type spill_alias_set; |
3072d30e | 1373 | insn_info_t insn_info = bb_info->last_insn; |
1374 | store_info_t store_info = NULL; | |
1375 | int group_id; | |
1376 | cselib_val *base = NULL; | |
aa140b76 | 1377 | insn_info_t ptr, last, redundant_reason; |
3072d30e | 1378 | bool store_is_unused; |
1379 | ||
1380 | if (GET_CODE (body) != SET && GET_CODE (body) != CLOBBER) | |
1381 | return 0; | |
1382 | ||
aa140b76 | 1383 | mem = SET_DEST (body); |
1384 | ||
3072d30e | 1385 | /* If this is not used, then this cannot be used to keep the insn |
1386 | from being deleted. On the other hand, it does provide something | |
1387 | that can be used to prove that another store is dead. */ | |
1388 | store_is_unused | |
aa140b76 | 1389 | = (find_reg_note (insn_info->insn, REG_UNUSED, mem) != NULL); |
3072d30e | 1390 | |
1391 | /* Check whether that value is a suitable memory location. */ | |
3072d30e | 1392 | if (!MEM_P (mem)) |
1393 | { | |
1394 | /* If the set or clobber is unused, then it does not effect our | |
1395 | ability to get rid of the entire insn. */ | |
1396 | if (!store_is_unused) | |
1397 | insn_info->cannot_delete = true; | |
1398 | return 0; | |
1399 | } | |
1400 | ||
1401 | /* At this point we know mem is a mem. */ | |
1402 | if (GET_MODE (mem) == BLKmode) | |
1403 | { | |
1404 | if (GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
1405 | { | |
1ca59310 | 1406 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1407 | fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n"); |
1408 | add_wild_read (bb_info); | |
1409 | insn_info->cannot_delete = true; | |
aa140b76 | 1410 | return 0; |
3072d30e | 1411 | } |
aa140b76 | 1412 | /* Handle (set (mem:BLK (addr) [... S36 ...]) (const_int 0)) |
1413 | as memset (addr, 0, 36); */ | |
5b2a69fa | 1414 | else if (!MEM_SIZE_KNOWN_P (mem) |
1415 | || MEM_SIZE (mem) <= 0 | |
1416 | || MEM_SIZE (mem) > MAX_OFFSET | |
aa140b76 | 1417 | || GET_CODE (body) != SET |
aa140b76 | 1418 | || !CONST_INT_P (SET_SRC (body))) |
3072d30e | 1419 | { |
aa140b76 | 1420 | if (!store_is_unused) |
1421 | { | |
1422 | /* If the set or clobber is unused, then it does not effect our | |
1423 | ability to get rid of the entire insn. */ | |
1424 | insn_info->cannot_delete = true; | |
1425 | clear_rhs_from_active_local_stores (); | |
1426 | } | |
1427 | return 0; | |
3072d30e | 1428 | } |
3072d30e | 1429 | } |
1430 | ||
1431 | /* We can still process a volatile mem, we just cannot delete it. */ | |
1432 | if (MEM_VOLATILE_P (mem)) | |
aa140b76 | 1433 | insn_info->cannot_delete = true; |
3072d30e | 1434 | |
1435 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
1436 | { | |
1437 | clear_rhs_from_active_local_stores (); | |
1438 | return 0; | |
1439 | } | |
1440 | ||
aa140b76 | 1441 | if (GET_MODE (mem) == BLKmode) |
5b2a69fa | 1442 | width = MEM_SIZE (mem); |
aa140b76 | 1443 | else |
e4209874 | 1444 | width = GET_MODE_SIZE (GET_MODE (mem)); |
3072d30e | 1445 | |
1446 | if (spill_alias_set) | |
1447 | { | |
1448 | bitmap store1 = clear_alias_group->store1_p; | |
1449 | bitmap store2 = clear_alias_group->store2_p; | |
aa140b76 | 1450 | |
1451 | gcc_assert (GET_MODE (mem) != BLKmode); | |
48e1416a | 1452 | |
6ef9bbe0 | 1453 | if (!bitmap_set_bit (store1, spill_alias_set)) |
3072d30e | 1454 | bitmap_set_bit (store2, spill_alias_set); |
48e1416a | 1455 | |
3072d30e | 1456 | if (clear_alias_group->offset_map_size_p < spill_alias_set) |
1457 | clear_alias_group->offset_map_size_p = spill_alias_set; | |
48e1416a | 1458 | |
55c5ac9f | 1459 | store_info = rtx_store_info_pool.allocate (); |
3072d30e | 1460 | |
1ca59310 | 1461 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1462 | fprintf (dump_file, " processing spill store %d(%s)\n", |
32c2fdea | 1463 | (int) spill_alias_set, GET_MODE_NAME (GET_MODE (mem))); |
3072d30e | 1464 | } |
1465 | else if (group_id >= 0) | |
1466 | { | |
1467 | /* In the restrictive case where the base is a constant or the | |
1468 | frame pointer we can do global analysis. */ | |
48e1416a | 1469 | |
1470 | group_info_t group | |
f1f41a6c | 1471 | = rtx_group_vec[group_id]; |
b4a708fb | 1472 | tree expr = MEM_EXPR (mem); |
48e1416a | 1473 | |
55c5ac9f | 1474 | store_info = rtx_store_info_pool.allocate (); |
b4a708fb | 1475 | set_usage_bits (group, offset, width, expr); |
3072d30e | 1476 | |
1ca59310 | 1477 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1478 | fprintf (dump_file, " processing const base store gid=%d[%d..%d)\n", |
1479 | group_id, (int)offset, (int)(offset+width)); | |
1480 | } | |
1481 | else | |
1482 | { | |
86e87ef6 | 1483 | if (may_be_sp_based_p (XEXP (mem, 0))) |
17e1318c | 1484 | insn_info->stack_pointer_based = true; |
3072d30e | 1485 | insn_info->contains_cselib_groups = true; |
17e1318c | 1486 | |
55c5ac9f | 1487 | store_info = cse_store_info_pool.allocate (); |
3072d30e | 1488 | group_id = -1; |
1489 | ||
1ca59310 | 1490 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1491 | fprintf (dump_file, " processing cselib store [%d..%d)\n", |
1492 | (int)offset, (int)(offset+width)); | |
1493 | } | |
1494 | ||
aa140b76 | 1495 | const_rhs = rhs = NULL_RTX; |
1496 | if (GET_CODE (body) == SET | |
1497 | /* No place to keep the value after ra. */ | |
1498 | && !reload_completed | |
1499 | && (REG_P (SET_SRC (body)) | |
1500 | || GET_CODE (SET_SRC (body)) == SUBREG | |
1501 | || CONSTANT_P (SET_SRC (body))) | |
1502 | && !MEM_VOLATILE_P (mem) | |
1503 | /* Sometimes the store and reload is used for truncation and | |
1504 | rounding. */ | |
1505 | && !(FLOAT_MODE_P (GET_MODE (mem)) && (flag_float_store))) | |
1506 | { | |
1507 | rhs = SET_SRC (body); | |
1508 | if (CONSTANT_P (rhs)) | |
1509 | const_rhs = rhs; | |
1510 | else if (body == PATTERN (insn_info->insn)) | |
1511 | { | |
1512 | rtx tem = find_reg_note (insn_info->insn, REG_EQUAL, NULL_RTX); | |
1513 | if (tem && CONSTANT_P (XEXP (tem, 0))) | |
1514 | const_rhs = XEXP (tem, 0); | |
1515 | } | |
1516 | if (const_rhs == NULL_RTX && REG_P (rhs)) | |
1517 | { | |
1518 | rtx tem = cselib_expand_value_rtx (rhs, scratch, 5); | |
1519 | ||
1520 | if (tem && CONSTANT_P (tem)) | |
1521 | const_rhs = tem; | |
1522 | } | |
1523 | } | |
1524 | ||
3072d30e | 1525 | /* Check to see if this stores causes some other stores to be |
1526 | dead. */ | |
1527 | ptr = active_local_stores; | |
1528 | last = NULL; | |
aa140b76 | 1529 | redundant_reason = NULL; |
82d2c88b | 1530 | mem = canon_rtx (mem); |
1531 | /* For alias_set != 0 canon_true_dependence should be never called. */ | |
1532 | if (spill_alias_set) | |
1533 | mem_addr = NULL_RTX; | |
1534 | else | |
1535 | { | |
1536 | if (group_id < 0) | |
1537 | mem_addr = base->val_rtx; | |
1538 | else | |
1539 | { | |
1540 | group_info_t group | |
f1f41a6c | 1541 | = rtx_group_vec[group_id]; |
82d2c88b | 1542 | mem_addr = group->canon_base_addr; |
1543 | } | |
90f3e775 | 1544 | /* get_addr can only handle VALUE but cannot handle expr like: |
1545 | VALUE + OFFSET, so call get_addr to get original addr for | |
1546 | mem_addr before plus_constant. */ | |
1547 | mem_addr = get_addr (mem_addr); | |
82d2c88b | 1548 | if (offset) |
87cf5753 | 1549 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
82d2c88b | 1550 | } |
3072d30e | 1551 | |
1552 | while (ptr) | |
1553 | { | |
1554 | insn_info_t next = ptr->next_local_store; | |
1555 | store_info_t s_info = ptr->store_rec; | |
9ce37fa7 | 1556 | bool del = true; |
3072d30e | 1557 | |
1558 | /* Skip the clobbers. We delete the active insn if this insn | |
6dfdc153 | 1559 | shadows the set. To have been put on the active list, it |
3072d30e | 1560 | has exactly on set. */ |
1561 | while (!s_info->is_set) | |
1562 | s_info = s_info->next; | |
1563 | ||
1564 | if (s_info->alias_set != spill_alias_set) | |
9ce37fa7 | 1565 | del = false; |
3072d30e | 1566 | else if (s_info->alias_set) |
1567 | { | |
48e1416a | 1568 | struct clear_alias_mode_holder *entry |
3072d30e | 1569 | = clear_alias_set_lookup (s_info->alias_set); |
1570 | /* Generally, spills cannot be processed if and of the | |
1571 | references to the slot have a different mode. But if | |
1572 | we are in the same block and mode is exactly the same | |
1573 | between this store and one before in the same block, | |
1574 | we can still delete it. */ | |
1575 | if ((GET_MODE (mem) == GET_MODE (s_info->mem)) | |
1576 | && (GET_MODE (mem) == entry->mode)) | |
1577 | { | |
9ce37fa7 | 1578 | del = true; |
aa140b76 | 1579 | set_all_positions_unneeded (s_info); |
3072d30e | 1580 | } |
1ca59310 | 1581 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1582 | fprintf (dump_file, " trying spill store in insn=%d alias_set=%d\n", |
32c2fdea | 1583 | INSN_UID (ptr->insn), (int) s_info->alias_set); |
3072d30e | 1584 | } |
48e1416a | 1585 | else if ((s_info->group_id == group_id) |
3072d30e | 1586 | && (s_info->cse_base == base)) |
1587 | { | |
1588 | HOST_WIDE_INT i; | |
1ca59310 | 1589 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1590 | fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n", |
48e1416a | 1591 | INSN_UID (ptr->insn), s_info->group_id, |
3072d30e | 1592 | (int)s_info->begin, (int)s_info->end); |
aa140b76 | 1593 | |
1594 | /* Even if PTR won't be eliminated as unneeded, if both | |
1595 | PTR and this insn store the same constant value, we might | |
1596 | eliminate this insn instead. */ | |
1597 | if (s_info->const_rhs | |
1598 | && const_rhs | |
1599 | && offset >= s_info->begin | |
1600 | && offset + width <= s_info->end | |
1601 | && all_positions_needed_p (s_info, offset - s_info->begin, | |
1602 | width)) | |
1603 | { | |
1604 | if (GET_MODE (mem) == BLKmode) | |
1605 | { | |
1606 | if (GET_MODE (s_info->mem) == BLKmode | |
1607 | && s_info->const_rhs == const_rhs) | |
1608 | redundant_reason = ptr; | |
1609 | } | |
1610 | else if (s_info->const_rhs == const0_rtx | |
1611 | && const_rhs == const0_rtx) | |
1612 | redundant_reason = ptr; | |
1613 | else | |
1614 | { | |
1615 | rtx val; | |
1616 | start_sequence (); | |
1617 | val = get_stored_val (s_info, GET_MODE (mem), | |
1618 | offset, offset + width, | |
1619 | BLOCK_FOR_INSN (insn_info->insn), | |
1620 | true); | |
1621 | if (get_insns () != NULL) | |
1622 | val = NULL_RTX; | |
1623 | end_sequence (); | |
1624 | if (val && rtx_equal_p (val, const_rhs)) | |
1625 | redundant_reason = ptr; | |
1626 | } | |
1627 | } | |
1628 | ||
1629 | for (i = MAX (offset, s_info->begin); | |
1630 | i < offset + width && i < s_info->end; | |
1631 | i++) | |
1632 | set_position_unneeded (s_info, i - s_info->begin); | |
3072d30e | 1633 | } |
1634 | else if (s_info->rhs) | |
1635 | /* Need to see if it is possible for this store to overwrite | |
1636 | the value of store_info. If it is, set the rhs to NULL to | |
1637 | keep it from being used to remove a load. */ | |
1638 | { | |
48e1416a | 1639 | if (canon_true_dependence (s_info->mem, |
3072d30e | 1640 | GET_MODE (s_info->mem), |
1641 | s_info->mem_addr, | |
376a287d | 1642 | mem, mem_addr)) |
aa140b76 | 1643 | { |
1644 | s_info->rhs = NULL; | |
1645 | s_info->const_rhs = NULL; | |
1646 | } | |
3072d30e | 1647 | } |
82d2c88b | 1648 | |
3072d30e | 1649 | /* An insn can be deleted if every position of every one of |
1650 | its s_infos is zero. */ | |
c75be2fe | 1651 | if (any_positions_needed_p (s_info)) |
9ce37fa7 | 1652 | del = false; |
aa140b76 | 1653 | |
9ce37fa7 | 1654 | if (del) |
3072d30e | 1655 | { |
1656 | insn_info_t insn_to_delete = ptr; | |
48e1416a | 1657 | |
1242bee6 | 1658 | active_local_stores_len--; |
3072d30e | 1659 | if (last) |
1660 | last->next_local_store = ptr->next_local_store; | |
1661 | else | |
1662 | active_local_stores = ptr->next_local_store; | |
48e1416a | 1663 | |
c75be2fe | 1664 | if (!insn_to_delete->cannot_delete) |
1665 | delete_dead_store_insn (insn_to_delete); | |
3072d30e | 1666 | } |
1667 | else | |
1668 | last = ptr; | |
48e1416a | 1669 | |
3072d30e | 1670 | ptr = next; |
1671 | } | |
48e1416a | 1672 | |
3072d30e | 1673 | /* Finish filling in the store_info. */ |
1674 | store_info->next = insn_info->store_rec; | |
1675 | insn_info->store_rec = store_info; | |
82d2c88b | 1676 | store_info->mem = mem; |
3072d30e | 1677 | store_info->alias_set = spill_alias_set; |
82d2c88b | 1678 | store_info->mem_addr = mem_addr; |
3072d30e | 1679 | store_info->cse_base = base; |
aa140b76 | 1680 | if (width > HOST_BITS_PER_WIDE_INT) |
1681 | { | |
1682 | store_info->is_large = true; | |
1683 | store_info->positions_needed.large.count = 0; | |
4fb07d00 | 1684 | store_info->positions_needed.large.bmap = BITMAP_ALLOC (&dse_bitmap_obstack); |
aa140b76 | 1685 | } |
1686 | else | |
1687 | { | |
1688 | store_info->is_large = false; | |
1689 | store_info->positions_needed.small_bitmask = lowpart_bitmask (width); | |
1690 | } | |
3072d30e | 1691 | store_info->group_id = group_id; |
1692 | store_info->begin = offset; | |
1693 | store_info->end = offset + width; | |
1694 | store_info->is_set = GET_CODE (body) == SET; | |
aa140b76 | 1695 | store_info->rhs = rhs; |
1696 | store_info->const_rhs = const_rhs; | |
1697 | store_info->redundant_reason = redundant_reason; | |
3072d30e | 1698 | |
3072d30e | 1699 | /* If this is a clobber, we return 0. We will only be able to |
1700 | delete this insn if there is only one store USED store, but we | |
1701 | can use the clobber to delete other stores earlier. */ | |
1702 | return store_info->is_set ? 1 : 0; | |
1703 | } | |
1704 | ||
1705 | ||
1706 | static void | |
1707 | dump_insn_info (const char * start, insn_info_t insn_info) | |
1708 | { | |
48e1416a | 1709 | fprintf (dump_file, "%s insn=%d %s\n", start, |
3072d30e | 1710 | INSN_UID (insn_info->insn), |
1711 | insn_info->store_rec ? "has store" : "naked"); | |
1712 | } | |
1713 | ||
1714 | ||
5c9051a4 | 1715 | /* If the modes are different and the value's source and target do not |
1716 | line up, we need to extract the value from lower part of the rhs of | |
1717 | the store, shift it, and then put it into a form that can be shoved | |
1718 | into the read_insn. This function generates a right SHIFT of a | |
1719 | value that is at least ACCESS_SIZE bytes wide of READ_MODE. The | |
1720 | shift sequence is returned or NULL if we failed to find a | |
1721 | shift. */ | |
1722 | ||
1723 | static rtx | |
10d4de0e | 1724 | find_shift_sequence (int access_size, |
5c9051a4 | 1725 | store_info_t store_info, |
3754d046 | 1726 | machine_mode read_mode, |
aa140b76 | 1727 | int shift, bool speed, bool require_cst) |
5c9051a4 | 1728 | { |
3754d046 | 1729 | machine_mode store_mode = GET_MODE (store_info->mem); |
1730 | machine_mode new_mode; | |
10d4de0e | 1731 | rtx read_reg = NULL; |
5c9051a4 | 1732 | |
1733 | /* Some machines like the x86 have shift insns for each size of | |
1734 | operand. Other machines like the ppc or the ia-64 may only have | |
1735 | shift insns that shift values within 32 or 64 bit registers. | |
1736 | This loop tries to find the smallest shift insn that will right | |
1737 | justify the value we want to read but is available in one insn on | |
1738 | the machine. */ | |
1739 | ||
10d4de0e | 1740 | for (new_mode = smallest_mode_for_size (access_size * BITS_PER_UNIT, |
1741 | MODE_INT); | |
1742 | GET_MODE_BITSIZE (new_mode) <= BITS_PER_WORD; | |
1743 | new_mode = GET_MODE_WIDER_MODE (new_mode)) | |
5c9051a4 | 1744 | { |
4cd001d5 | 1745 | rtx target, new_reg, new_lhs; |
1746 | rtx_insn *shift_seq, *insn; | |
171557e8 | 1747 | int cost; |
af97461e | 1748 | |
4ed4afb9 | 1749 | /* If a constant was stored into memory, try to simplify it here, |
1750 | otherwise the cost of the shift might preclude this optimization | |
1751 | e.g. at -Os, even when no actual shift will be needed. */ | |
aa140b76 | 1752 | if (store_info->const_rhs) |
4ed4afb9 | 1753 | { |
1754 | unsigned int byte = subreg_lowpart_offset (new_mode, store_mode); | |
aa140b76 | 1755 | rtx ret = simplify_subreg (new_mode, store_info->const_rhs, |
1756 | store_mode, byte); | |
4ed4afb9 | 1757 | if (ret && CONSTANT_P (ret)) |
1758 | { | |
1759 | ret = simplify_const_binary_operation (LSHIFTRT, new_mode, | |
1760 | ret, GEN_INT (shift)); | |
1761 | if (ret && CONSTANT_P (ret)) | |
1762 | { | |
1763 | byte = subreg_lowpart_offset (read_mode, new_mode); | |
1764 | ret = simplify_subreg (read_mode, ret, new_mode, byte); | |
1765 | if (ret && CONSTANT_P (ret) | |
5ae4887d | 1766 | && (set_src_cost (ret, read_mode, speed) |
1767 | <= COSTS_N_INSNS (1))) | |
4ed4afb9 | 1768 | return ret; |
1769 | } | |
1770 | } | |
1771 | } | |
1772 | ||
aa140b76 | 1773 | if (require_cst) |
1774 | return NULL_RTX; | |
1775 | ||
10d4de0e | 1776 | /* Try a wider mode if truncating the store mode to NEW_MODE |
1777 | requires a real instruction. */ | |
1778 | if (GET_MODE_BITSIZE (new_mode) < GET_MODE_BITSIZE (store_mode) | |
396f2130 | 1779 | && !TRULY_NOOP_TRUNCATION_MODES_P (new_mode, store_mode)) |
af97461e | 1780 | continue; |
1781 | ||
10d4de0e | 1782 | /* Also try a wider mode if the necessary punning is either not |
1783 | desirable or not possible. */ | |
1784 | if (!CONSTANT_P (store_info->rhs) | |
1785 | && !MODES_TIEABLE_P (new_mode, store_mode)) | |
1786 | continue; | |
10d4de0e | 1787 | |
af97461e | 1788 | new_reg = gen_reg_rtx (new_mode); |
5c9051a4 | 1789 | |
1790 | start_sequence (); | |
1791 | ||
1792 | /* In theory we could also check for an ashr. Ian Taylor knows | |
1793 | of one dsp where the cost of these two was not the same. But | |
1794 | this really is a rare case anyway. */ | |
1795 | target = expand_binop (new_mode, lshr_optab, new_reg, | |
1796 | GEN_INT (shift), new_reg, 1, OPTAB_DIRECT); | |
1797 | ||
597d5470 | 1798 | shift_seq = get_insns (); |
1799 | end_sequence (); | |
5c9051a4 | 1800 | |
597d5470 | 1801 | if (target != new_reg || shift_seq == NULL) |
1802 | continue; | |
1803 | ||
1804 | cost = 0; | |
1805 | for (insn = shift_seq; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
1806 | if (INSN_P (insn)) | |
f529eb25 | 1807 | cost += insn_rtx_cost (PATTERN (insn), speed); |
597d5470 | 1808 | |
1809 | /* The computation up to here is essentially independent | |
1810 | of the arguments and could be precomputed. It may | |
1811 | not be worth doing so. We could precompute if | |
1812 | worthwhile or at least cache the results. The result | |
5133fd21 | 1813 | technically depends on both SHIFT and ACCESS_SIZE, |
1814 | but in practice the answer will depend only on ACCESS_SIZE. */ | |
597d5470 | 1815 | |
1816 | if (cost > COSTS_N_INSNS (1)) | |
1817 | continue; | |
1818 | ||
171557e8 | 1819 | new_lhs = extract_low_bits (new_mode, store_mode, |
1820 | copy_rtx (store_info->rhs)); | |
1821 | if (new_lhs == NULL_RTX) | |
1822 | continue; | |
1823 | ||
597d5470 | 1824 | /* We found an acceptable shift. Generate a move to |
1825 | take the value from the store and put it into the | |
1826 | shift pseudo, then shift it, then generate another | |
1827 | move to put in into the target of the read. */ | |
10d4de0e | 1828 | emit_move_insn (new_reg, new_lhs); |
597d5470 | 1829 | emit_insn (shift_seq); |
10d4de0e | 1830 | read_reg = extract_low_bits (read_mode, new_mode, new_reg); |
597d5470 | 1831 | break; |
5c9051a4 | 1832 | } |
1833 | ||
10d4de0e | 1834 | return read_reg; |
5c9051a4 | 1835 | } |
1836 | ||
1837 | ||
a1b0a968 | 1838 | /* Call back for note_stores to find the hard regs set or clobbered by |
1839 | insn. Data is a bitmap of the hardregs set so far. */ | |
1840 | ||
1841 | static void | |
1842 | look_for_hardregs (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) | |
1843 | { | |
1844 | bitmap regs_set = (bitmap) data; | |
1845 | ||
1846 | if (REG_P (x) | |
771d4616 | 1847 | && HARD_REGISTER_P (x)) |
0933f1d9 | 1848 | bitmap_set_range (regs_set, REGNO (x), REG_NREGS (x)); |
a1b0a968 | 1849 | } |
1850 | ||
aa140b76 | 1851 | /* Helper function for replace_read and record_store. |
1852 | Attempt to return a value stored in STORE_INFO, from READ_BEGIN | |
1853 | to one before READ_END bytes read in READ_MODE. Return NULL | |
1854 | if not successful. If REQUIRE_CST is true, return always constant. */ | |
1855 | ||
1856 | static rtx | |
3754d046 | 1857 | get_stored_val (store_info_t store_info, machine_mode read_mode, |
aa140b76 | 1858 | HOST_WIDE_INT read_begin, HOST_WIDE_INT read_end, |
1859 | basic_block bb, bool require_cst) | |
1860 | { | |
3754d046 | 1861 | machine_mode store_mode = GET_MODE (store_info->mem); |
aa140b76 | 1862 | int shift; |
1863 | int access_size; /* In bytes. */ | |
1864 | rtx read_reg; | |
1865 | ||
1866 | /* To get here the read is within the boundaries of the write so | |
1867 | shift will never be negative. Start out with the shift being in | |
1868 | bytes. */ | |
1869 | if (store_mode == BLKmode) | |
1870 | shift = 0; | |
1871 | else if (BYTES_BIG_ENDIAN) | |
1872 | shift = store_info->end - read_end; | |
1873 | else | |
1874 | shift = read_begin - store_info->begin; | |
1875 | ||
1876 | access_size = shift + GET_MODE_SIZE (read_mode); | |
1877 | ||
1878 | /* From now on it is bits. */ | |
1879 | shift *= BITS_PER_UNIT; | |
1880 | ||
1881 | if (shift) | |
1882 | read_reg = find_shift_sequence (access_size, store_info, read_mode, shift, | |
1883 | optimize_bb_for_speed_p (bb), | |
1884 | require_cst); | |
1885 | else if (store_mode == BLKmode) | |
1886 | { | |
1887 | /* The store is a memset (addr, const_val, const_size). */ | |
1888 | gcc_assert (CONST_INT_P (store_info->rhs)); | |
1889 | store_mode = int_mode_for_mode (read_mode); | |
1890 | if (store_mode == BLKmode) | |
1891 | read_reg = NULL_RTX; | |
1892 | else if (store_info->rhs == const0_rtx) | |
1893 | read_reg = extract_low_bits (read_mode, store_mode, const0_rtx); | |
1894 | else if (GET_MODE_BITSIZE (store_mode) > HOST_BITS_PER_WIDE_INT | |
1895 | || BITS_PER_UNIT >= HOST_BITS_PER_WIDE_INT) | |
1896 | read_reg = NULL_RTX; | |
1897 | else | |
1898 | { | |
1899 | unsigned HOST_WIDE_INT c | |
1900 | = INTVAL (store_info->rhs) | |
1901 | & (((HOST_WIDE_INT) 1 << BITS_PER_UNIT) - 1); | |
1902 | int shift = BITS_PER_UNIT; | |
1903 | while (shift < HOST_BITS_PER_WIDE_INT) | |
1904 | { | |
1905 | c |= (c << shift); | |
1906 | shift <<= 1; | |
1907 | } | |
f62058c3 | 1908 | read_reg = gen_int_mode (c, store_mode); |
aa140b76 | 1909 | read_reg = extract_low_bits (read_mode, store_mode, read_reg); |
1910 | } | |
1911 | } | |
1912 | else if (store_info->const_rhs | |
1913 | && (require_cst | |
1914 | || GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))) | |
1915 | read_reg = extract_low_bits (read_mode, store_mode, | |
1916 | copy_rtx (store_info->const_rhs)); | |
1917 | else | |
1918 | read_reg = extract_low_bits (read_mode, store_mode, | |
1919 | copy_rtx (store_info->rhs)); | |
1920 | if (require_cst && read_reg && !CONSTANT_P (read_reg)) | |
1921 | read_reg = NULL_RTX; | |
1922 | return read_reg; | |
1923 | } | |
a1b0a968 | 1924 | |
3072d30e | 1925 | /* Take a sequence of: |
1926 | A <- r1 | |
1927 | ... | |
1928 | ... <- A | |
1929 | ||
48e1416a | 1930 | and change it into |
3072d30e | 1931 | r2 <- r1 |
1932 | A <- r1 | |
1933 | ... | |
1934 | ... <- r2 | |
1935 | ||
5c9051a4 | 1936 | or |
1937 | ||
1938 | r3 <- extract (r1) | |
1939 | r3 <- r3 >> shift | |
1940 | r2 <- extract (r3) | |
1941 | ... <- r2 | |
1942 | ||
1943 | or | |
1944 | ||
1945 | r2 <- extract (r1) | |
1946 | ... <- r2 | |
1947 | ||
1948 | Depending on the alignment and the mode of the store and | |
1949 | subsequent load. | |
1950 | ||
1951 | ||
1952 | The STORE_INFO and STORE_INSN are for the store and READ_INFO | |
3072d30e | 1953 | and READ_INSN are for the read. Return true if the replacement |
1954 | went ok. */ | |
1955 | ||
1956 | static bool | |
48e1416a | 1957 | replace_read (store_info_t store_info, insn_info_t store_insn, |
aa140b76 | 1958 | read_info_t read_info, insn_info_t read_insn, rtx *loc, |
1959 | bitmap regs_live) | |
3072d30e | 1960 | { |
3754d046 | 1961 | machine_mode store_mode = GET_MODE (store_info->mem); |
1962 | machine_mode read_mode = GET_MODE (read_info->mem); | |
4cd001d5 | 1963 | rtx_insn *insns, *this_insn; |
1964 | rtx read_reg; | |
aa140b76 | 1965 | basic_block bb; |
5c9051a4 | 1966 | |
3072d30e | 1967 | if (!dbg_cnt (dse)) |
1968 | return false; | |
1969 | ||
10d4de0e | 1970 | /* Create a sequence of instructions to set up the read register. |
1971 | This sequence goes immediately before the store and its result | |
1972 | is read by the load. | |
1973 | ||
1974 | We need to keep this in perspective. We are replacing a read | |
5c9051a4 | 1975 | with a sequence of insns, but the read will almost certainly be |
1976 | in cache, so it is not going to be an expensive one. Thus, we | |
1977 | are not willing to do a multi insn shift or worse a subroutine | |
1978 | call to get rid of the read. */ | |
1ca59310 | 1979 | if (dump_file && (dump_flags & TDF_DETAILS)) |
10d4de0e | 1980 | fprintf (dump_file, "trying to replace %smode load in insn %d" |
1981 | " from %smode store in insn %d\n", | |
1982 | GET_MODE_NAME (read_mode), INSN_UID (read_insn->insn), | |
1983 | GET_MODE_NAME (store_mode), INSN_UID (store_insn->insn)); | |
1984 | start_sequence (); | |
aa140b76 | 1985 | bb = BLOCK_FOR_INSN (read_insn->insn); |
1986 | read_reg = get_stored_val (store_info, | |
1987 | read_mode, read_info->begin, read_info->end, | |
1988 | bb, false); | |
10d4de0e | 1989 | if (read_reg == NULL_RTX) |
5c9051a4 | 1990 | { |
10d4de0e | 1991 | end_sequence (); |
1ca59310 | 1992 | if (dump_file && (dump_flags & TDF_DETAILS)) |
10d4de0e | 1993 | fprintf (dump_file, " -- could not extract bits of stored value\n"); |
1994 | return false; | |
5c9051a4 | 1995 | } |
10d4de0e | 1996 | /* Force the value into a new register so that it won't be clobbered |
1997 | between the store and the load. */ | |
1998 | read_reg = copy_to_mode_reg (read_mode, read_reg); | |
1999 | insns = get_insns (); | |
2000 | end_sequence (); | |
5c9051a4 | 2001 | |
a1b0a968 | 2002 | if (insns != NULL_RTX) |
2003 | { | |
2004 | /* Now we have to scan the set of new instructions to see if the | |
2005 | sequence contains and sets of hardregs that happened to be | |
2006 | live at this point. For instance, this can happen if one of | |
2007 | the insns sets the CC and the CC happened to be live at that | |
2008 | point. This does occasionally happen, see PR 37922. */ | |
4fb07d00 | 2009 | bitmap regs_set = BITMAP_ALLOC (®_obstack); |
a1b0a968 | 2010 | |
2011 | for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn)) | |
2012 | note_stores (PATTERN (this_insn), look_for_hardregs, regs_set); | |
48e1416a | 2013 | |
a1b0a968 | 2014 | bitmap_and_into (regs_set, regs_live); |
2015 | if (!bitmap_empty_p (regs_set)) | |
2016 | { | |
1ca59310 | 2017 | if (dump_file && (dump_flags & TDF_DETAILS)) |
a1b0a968 | 2018 | { |
48e1416a | 2019 | fprintf (dump_file, |
a1b0a968 | 2020 | "abandoning replacement because sequence clobbers live hardregs:"); |
2021 | df_print_regset (dump_file, regs_set); | |
2022 | } | |
48e1416a | 2023 | |
a1b0a968 | 2024 | BITMAP_FREE (regs_set); |
2025 | return false; | |
2026 | } | |
2027 | BITMAP_FREE (regs_set); | |
2028 | } | |
2029 | ||
5c9051a4 | 2030 | if (validate_change (read_insn->insn, loc, read_reg, 0)) |
3072d30e | 2031 | { |
e16712b1 | 2032 | deferred_change_t change = deferred_change_pool.allocate (); |
48e1416a | 2033 | |
5c9051a4 | 2034 | /* Insert this right before the store insn where it will be safe |
2035 | from later insns that might change it before the read. */ | |
2036 | emit_insn_before (insns, store_insn->insn); | |
48e1416a | 2037 | |
5c9051a4 | 2038 | /* And now for the kludge part: cselib croaks if you just |
2039 | return at this point. There are two reasons for this: | |
48e1416a | 2040 | |
5c9051a4 | 2041 | 1) Cselib has an idea of how many pseudos there are and |
2042 | that does not include the new ones we just added. | |
48e1416a | 2043 | |
5c9051a4 | 2044 | 2) Cselib does not know about the move insn we added |
2045 | above the store_info, and there is no way to tell it | |
2046 | about it, because it has "moved on". | |
48e1416a | 2047 | |
5c9051a4 | 2048 | Problem (1) is fixable with a certain amount of engineering. |
2049 | Problem (2) is requires starting the bb from scratch. This | |
2050 | could be expensive. | |
48e1416a | 2051 | |
5c9051a4 | 2052 | So we are just going to have to lie. The move/extraction |
2053 | insns are not really an issue, cselib did not see them. But | |
2054 | the use of the new pseudo read_insn is a real problem because | |
2055 | cselib has not scanned this insn. The way that we solve this | |
2056 | problem is that we are just going to put the mem back for now | |
2057 | and when we are finished with the block, we undo this. We | |
2058 | keep a table of mems to get rid of. At the end of the basic | |
2059 | block we can put them back. */ | |
48e1416a | 2060 | |
5c9051a4 | 2061 | *loc = read_info->mem; |
55c5ac9f | 2062 | change->next = deferred_change_list; |
2063 | deferred_change_list = change; | |
2064 | change->loc = loc; | |
2065 | change->reg = read_reg; | |
48e1416a | 2066 | |
5c9051a4 | 2067 | /* Get rid of the read_info, from the point of view of the |
2068 | rest of dse, play like this read never happened. */ | |
2069 | read_insn->read_rec = read_info->next; | |
e16712b1 | 2070 | read_info_type_pool.remove (read_info); |
1ca59310 | 2071 | if (dump_file && (dump_flags & TDF_DETAILS)) |
10d4de0e | 2072 | { |
2073 | fprintf (dump_file, " -- replaced the loaded MEM with "); | |
2074 | print_simple_rtl (dump_file, read_reg); | |
2075 | fprintf (dump_file, "\n"); | |
2076 | } | |
5c9051a4 | 2077 | return true; |
3072d30e | 2078 | } |
48e1416a | 2079 | else |
3072d30e | 2080 | { |
1ca59310 | 2081 | if (dump_file && (dump_flags & TDF_DETAILS)) |
10d4de0e | 2082 | { |
2083 | fprintf (dump_file, " -- replacing the loaded MEM with "); | |
2084 | print_simple_rtl (dump_file, read_reg); | |
2085 | fprintf (dump_file, " led to an invalid instruction\n"); | |
2086 | } | |
3072d30e | 2087 | return false; |
2088 | } | |
2089 | } | |
2090 | ||
ec1203cd | 2091 | /* Check the address of MEM *LOC and kill any appropriate stores that may |
2092 | be active. */ | |
3072d30e | 2093 | |
ec1203cd | 2094 | static void |
2095 | check_mem_read_rtx (rtx *loc, bb_info_t bb_info) | |
3072d30e | 2096 | { |
82d2c88b | 2097 | rtx mem = *loc, mem_addr; |
3072d30e | 2098 | insn_info_t insn_info; |
2099 | HOST_WIDE_INT offset = 0; | |
2100 | HOST_WIDE_INT width = 0; | |
32c2fdea | 2101 | alias_set_type spill_alias_set = 0; |
48e1416a | 2102 | cselib_val *base = NULL; |
3072d30e | 2103 | int group_id; |
2104 | read_info_t read_info; | |
2105 | ||
3072d30e | 2106 | insn_info = bb_info->last_insn; |
2107 | ||
2108 | if ((MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2109 | || (MEM_VOLATILE_P (mem))) | |
2110 | { | |
1ca59310 | 2111 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2112 | fprintf (dump_file, " adding wild read, volatile or barrier.\n"); |
2113 | add_wild_read (bb_info); | |
2114 | insn_info->cannot_delete = true; | |
ec1203cd | 2115 | return; |
3072d30e | 2116 | } |
2117 | ||
2118 | /* If it is reading readonly mem, then there can be no conflict with | |
2119 | another write. */ | |
2120 | if (MEM_READONLY_P (mem)) | |
ec1203cd | 2121 | return; |
3072d30e | 2122 | |
2123 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
2124 | { | |
1ca59310 | 2125 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2126 | fprintf (dump_file, " adding wild read, canon_address failure.\n"); |
2127 | add_wild_read (bb_info); | |
ec1203cd | 2128 | return; |
3072d30e | 2129 | } |
2130 | ||
2131 | if (GET_MODE (mem) == BLKmode) | |
2132 | width = -1; | |
2133 | else | |
2134 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
2135 | ||
e16712b1 | 2136 | read_info = read_info_type_pool.allocate (); |
3072d30e | 2137 | read_info->group_id = group_id; |
2138 | read_info->mem = mem; | |
2139 | read_info->alias_set = spill_alias_set; | |
2140 | read_info->begin = offset; | |
2141 | read_info->end = offset + width; | |
2142 | read_info->next = insn_info->read_rec; | |
2143 | insn_info->read_rec = read_info; | |
82d2c88b | 2144 | /* For alias_set != 0 canon_true_dependence should be never called. */ |
2145 | if (spill_alias_set) | |
2146 | mem_addr = NULL_RTX; | |
2147 | else | |
2148 | { | |
2149 | if (group_id < 0) | |
2150 | mem_addr = base->val_rtx; | |
2151 | else | |
2152 | { | |
2153 | group_info_t group | |
f1f41a6c | 2154 | = rtx_group_vec[group_id]; |
82d2c88b | 2155 | mem_addr = group->canon_base_addr; |
2156 | } | |
90f3e775 | 2157 | /* get_addr can only handle VALUE but cannot handle expr like: |
2158 | VALUE + OFFSET, so call get_addr to get original addr for | |
2159 | mem_addr before plus_constant. */ | |
2160 | mem_addr = get_addr (mem_addr); | |
82d2c88b | 2161 | if (offset) |
87cf5753 | 2162 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
82d2c88b | 2163 | } |
3072d30e | 2164 | |
bef304b8 | 2165 | /* We ignore the clobbers in store_info. The is mildly aggressive, |
3072d30e | 2166 | but there really should not be a clobber followed by a read. */ |
2167 | ||
2168 | if (spill_alias_set) | |
2169 | { | |
2170 | insn_info_t i_ptr = active_local_stores; | |
2171 | insn_info_t last = NULL; | |
2172 | ||
1ca59310 | 2173 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2174 | fprintf (dump_file, " processing spill load %d\n", |
32c2fdea | 2175 | (int) spill_alias_set); |
3072d30e | 2176 | |
2177 | while (i_ptr) | |
2178 | { | |
2179 | store_info_t store_info = i_ptr->store_rec; | |
2180 | ||
2181 | /* Skip the clobbers. */ | |
2182 | while (!store_info->is_set) | |
2183 | store_info = store_info->next; | |
48e1416a | 2184 | |
3072d30e | 2185 | if (store_info->alias_set == spill_alias_set) |
2186 | { | |
1ca59310 | 2187 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2188 | dump_insn_info ("removing from active", i_ptr); |
2189 | ||
1242bee6 | 2190 | active_local_stores_len--; |
3072d30e | 2191 | if (last) |
2192 | last->next_local_store = i_ptr->next_local_store; | |
2193 | else | |
2194 | active_local_stores = i_ptr->next_local_store; | |
2195 | } | |
2196 | else | |
2197 | last = i_ptr; | |
2198 | i_ptr = i_ptr->next_local_store; | |
2199 | } | |
2200 | } | |
2201 | else if (group_id >= 0) | |
2202 | { | |
2203 | /* This is the restricted case where the base is a constant or | |
2204 | the frame pointer and offset is a constant. */ | |
2205 | insn_info_t i_ptr = active_local_stores; | |
2206 | insn_info_t last = NULL; | |
48e1416a | 2207 | |
1ca59310 | 2208 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2209 | { |
2210 | if (width == -1) | |
2211 | fprintf (dump_file, " processing const load gid=%d[BLK]\n", | |
2212 | group_id); | |
2213 | else | |
2214 | fprintf (dump_file, " processing const load gid=%d[%d..%d)\n", | |
2215 | group_id, (int)offset, (int)(offset+width)); | |
2216 | } | |
2217 | ||
2218 | while (i_ptr) | |
2219 | { | |
2220 | bool remove = false; | |
2221 | store_info_t store_info = i_ptr->store_rec; | |
48e1416a | 2222 | |
3072d30e | 2223 | /* Skip the clobbers. */ |
2224 | while (!store_info->is_set) | |
2225 | store_info = store_info->next; | |
48e1416a | 2226 | |
3072d30e | 2227 | /* There are three cases here. */ |
2228 | if (store_info->group_id < 0) | |
2229 | /* We have a cselib store followed by a read from a | |
2230 | const base. */ | |
48e1416a | 2231 | remove |
2232 | = canon_true_dependence (store_info->mem, | |
3072d30e | 2233 | GET_MODE (store_info->mem), |
2234 | store_info->mem_addr, | |
376a287d | 2235 | mem, mem_addr); |
48e1416a | 2236 | |
3072d30e | 2237 | else if (group_id == store_info->group_id) |
2238 | { | |
2239 | /* This is a block mode load. We may get lucky and | |
2240 | canon_true_dependence may save the day. */ | |
2241 | if (width == -1) | |
48e1416a | 2242 | remove |
2243 | = canon_true_dependence (store_info->mem, | |
3072d30e | 2244 | GET_MODE (store_info->mem), |
2245 | store_info->mem_addr, | |
376a287d | 2246 | mem, mem_addr); |
48e1416a | 2247 | |
3072d30e | 2248 | /* If this read is just reading back something that we just |
2249 | stored, rewrite the read. */ | |
48e1416a | 2250 | else |
3072d30e | 2251 | { |
2252 | if (store_info->rhs | |
aa140b76 | 2253 | && offset >= store_info->begin |
2254 | && offset + width <= store_info->end | |
2255 | && all_positions_needed_p (store_info, | |
2256 | offset - store_info->begin, | |
2257 | width) | |
2258 | && replace_read (store_info, i_ptr, read_info, | |
2259 | insn_info, loc, bb_info->regs_live)) | |
ec1203cd | 2260 | return; |
aa140b76 | 2261 | |
3072d30e | 2262 | /* The bases are the same, just see if the offsets |
2263 | overlap. */ | |
48e1416a | 2264 | if ((offset < store_info->end) |
3072d30e | 2265 | && (offset + width > store_info->begin)) |
2266 | remove = true; | |
2267 | } | |
2268 | } | |
48e1416a | 2269 | |
2270 | /* else | |
3072d30e | 2271 | The else case that is missing here is that the |
2272 | bases are constant but different. There is nothing | |
2273 | to do here because there is no overlap. */ | |
48e1416a | 2274 | |
3072d30e | 2275 | if (remove) |
2276 | { | |
1ca59310 | 2277 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2278 | dump_insn_info ("removing from active", i_ptr); |
2279 | ||
1242bee6 | 2280 | active_local_stores_len--; |
3072d30e | 2281 | if (last) |
2282 | last->next_local_store = i_ptr->next_local_store; | |
2283 | else | |
2284 | active_local_stores = i_ptr->next_local_store; | |
2285 | } | |
2286 | else | |
2287 | last = i_ptr; | |
2288 | i_ptr = i_ptr->next_local_store; | |
2289 | } | |
2290 | } | |
48e1416a | 2291 | else |
3072d30e | 2292 | { |
2293 | insn_info_t i_ptr = active_local_stores; | |
2294 | insn_info_t last = NULL; | |
1ca59310 | 2295 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2296 | { |
2297 | fprintf (dump_file, " processing cselib load mem:"); | |
2298 | print_inline_rtx (dump_file, mem, 0); | |
2299 | fprintf (dump_file, "\n"); | |
2300 | } | |
2301 | ||
2302 | while (i_ptr) | |
2303 | { | |
2304 | bool remove = false; | |
2305 | store_info_t store_info = i_ptr->store_rec; | |
48e1416a | 2306 | |
1ca59310 | 2307 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2308 | fprintf (dump_file, " processing cselib load against insn %d\n", |
2309 | INSN_UID (i_ptr->insn)); | |
2310 | ||
2311 | /* Skip the clobbers. */ | |
2312 | while (!store_info->is_set) | |
2313 | store_info = store_info->next; | |
2314 | ||
2315 | /* If this read is just reading back something that we just | |
2316 | stored, rewrite the read. */ | |
2317 | if (store_info->rhs | |
2318 | && store_info->group_id == -1 | |
2319 | && store_info->cse_base == base | |
2ffe5515 | 2320 | && width != -1 |
aa140b76 | 2321 | && offset >= store_info->begin |
2322 | && offset + width <= store_info->end | |
2323 | && all_positions_needed_p (store_info, | |
2324 | offset - store_info->begin, width) | |
2325 | && replace_read (store_info, i_ptr, read_info, insn_info, loc, | |
2326 | bb_info->regs_live)) | |
ec1203cd | 2327 | return; |
3072d30e | 2328 | |
2329 | if (!store_info->alias_set) | |
48e1416a | 2330 | remove = canon_true_dependence (store_info->mem, |
3072d30e | 2331 | GET_MODE (store_info->mem), |
2332 | store_info->mem_addr, | |
376a287d | 2333 | mem, mem_addr); |
48e1416a | 2334 | |
3072d30e | 2335 | if (remove) |
2336 | { | |
1ca59310 | 2337 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2338 | dump_insn_info ("removing from active", i_ptr); |
48e1416a | 2339 | |
1242bee6 | 2340 | active_local_stores_len--; |
3072d30e | 2341 | if (last) |
2342 | last->next_local_store = i_ptr->next_local_store; | |
2343 | else | |
2344 | active_local_stores = i_ptr->next_local_store; | |
2345 | } | |
2346 | else | |
2347 | last = i_ptr; | |
2348 | i_ptr = i_ptr->next_local_store; | |
2349 | } | |
2350 | } | |
3072d30e | 2351 | } |
2352 | ||
ec1203cd | 2353 | /* A note_uses callback in which DATA points the INSN_INFO for |
3072d30e | 2354 | as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns |
2355 | true for any part of *LOC. */ | |
2356 | ||
2357 | static void | |
2358 | check_mem_read_use (rtx *loc, void *data) | |
2359 | { | |
ec1203cd | 2360 | subrtx_ptr_iterator::array_type array; |
2361 | FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST) | |
2362 | { | |
2363 | rtx *loc = *iter; | |
2364 | if (MEM_P (*loc)) | |
2365 | check_mem_read_rtx (loc, (bb_info_t) data); | |
2366 | } | |
3072d30e | 2367 | } |
2368 | ||
aa140b76 | 2369 | |
2370 | /* Get arguments passed to CALL_INSN. Return TRUE if successful. | |
2371 | So far it only handles arguments passed in registers. */ | |
2372 | ||
2373 | static bool | |
2374 | get_call_args (rtx call_insn, tree fn, rtx *args, int nargs) | |
2375 | { | |
39cba157 | 2376 | CUMULATIVE_ARGS args_so_far_v; |
2377 | cumulative_args_t args_so_far; | |
aa140b76 | 2378 | tree arg; |
2379 | int idx; | |
2380 | ||
39cba157 | 2381 | INIT_CUMULATIVE_ARGS (args_so_far_v, TREE_TYPE (fn), NULL_RTX, 0, 3); |
2382 | args_so_far = pack_cumulative_args (&args_so_far_v); | |
aa140b76 | 2383 | |
2384 | arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2385 | for (idx = 0; | |
2386 | arg != void_list_node && idx < nargs; | |
2387 | arg = TREE_CHAIN (arg), idx++) | |
2388 | { | |
3754d046 | 2389 | machine_mode mode = TYPE_MODE (TREE_VALUE (arg)); |
f387af4f | 2390 | rtx reg, link, tmp; |
39cba157 | 2391 | reg = targetm.calls.function_arg (args_so_far, mode, NULL_TREE, true); |
aa140b76 | 2392 | if (!reg || !REG_P (reg) || GET_MODE (reg) != mode |
2393 | || GET_MODE_CLASS (mode) != MODE_INT) | |
2394 | return false; | |
2395 | ||
2396 | for (link = CALL_INSN_FUNCTION_USAGE (call_insn); | |
2397 | link; | |
2398 | link = XEXP (link, 1)) | |
2399 | if (GET_CODE (XEXP (link, 0)) == USE) | |
2400 | { | |
2401 | args[idx] = XEXP (XEXP (link, 0), 0); | |
2402 | if (REG_P (args[idx]) | |
2403 | && REGNO (args[idx]) == REGNO (reg) | |
2404 | && (GET_MODE (args[idx]) == mode | |
2405 | || (GET_MODE_CLASS (GET_MODE (args[idx])) == MODE_INT | |
2406 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2407 | <= UNITS_PER_WORD) | |
2408 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2409 | > GET_MODE_SIZE (mode))))) | |
2410 | break; | |
2411 | } | |
2412 | if (!link) | |
2413 | return false; | |
2414 | ||
2415 | tmp = cselib_expand_value_rtx (args[idx], scratch, 5); | |
2416 | if (GET_MODE (args[idx]) != mode) | |
2417 | { | |
2418 | if (!tmp || !CONST_INT_P (tmp)) | |
2419 | return false; | |
f62058c3 | 2420 | tmp = gen_int_mode (INTVAL (tmp), mode); |
aa140b76 | 2421 | } |
2422 | if (tmp) | |
2423 | args[idx] = tmp; | |
2424 | ||
39cba157 | 2425 | targetm.calls.function_arg_advance (args_so_far, mode, NULL_TREE, true); |
aa140b76 | 2426 | } |
2427 | if (arg != void_list_node || idx != nargs) | |
2428 | return false; | |
2429 | return true; | |
2430 | } | |
2431 | ||
5a9ecd4a | 2432 | /* Return a bitmap of the fixed registers contained in IN. */ |
2433 | ||
2434 | static bitmap | |
2435 | copy_fixed_regs (const_bitmap in) | |
2436 | { | |
2437 | bitmap ret; | |
2438 | ||
2439 | ret = ALLOC_REG_SET (NULL); | |
2440 | bitmap_and (ret, in, fixed_reg_set_regset); | |
2441 | return ret; | |
2442 | } | |
aa140b76 | 2443 | |
3072d30e | 2444 | /* Apply record_store to all candidate stores in INSN. Mark INSN |
2445 | if some part of it is not a candidate store and assigns to a | |
2446 | non-register target. */ | |
2447 | ||
2448 | static void | |
ebabb7a3 | 2449 | scan_insn (bb_info_t bb_info, rtx_insn *insn) |
3072d30e | 2450 | { |
2451 | rtx body; | |
e16712b1 | 2452 | insn_info_type *insn_info = insn_info_type_pool.allocate (); |
3072d30e | 2453 | int mems_found = 0; |
55c5ac9f | 2454 | memset (insn_info, 0, sizeof (struct insn_info_type)); |
3072d30e | 2455 | |
1ca59310 | 2456 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2457 | fprintf (dump_file, "\n**scanning insn=%d\n", |
2458 | INSN_UID (insn)); | |
2459 | ||
2460 | insn_info->prev_insn = bb_info->last_insn; | |
2461 | insn_info->insn = insn; | |
2462 | bb_info->last_insn = insn_info; | |
48e1416a | 2463 | |
9845d120 | 2464 | if (DEBUG_INSN_P (insn)) |
2465 | { | |
2466 | insn_info->cannot_delete = true; | |
2467 | return; | |
2468 | } | |
3072d30e | 2469 | |
3072d30e | 2470 | /* Look at all of the uses in the insn. */ |
2471 | note_uses (&PATTERN (insn), check_mem_read_use, bb_info); | |
2472 | ||
2473 | if (CALL_P (insn)) | |
2474 | { | |
aa140b76 | 2475 | bool const_call; |
2476 | tree memset_call = NULL_TREE; | |
2477 | ||
3072d30e | 2478 | insn_info->cannot_delete = true; |
17e1318c | 2479 | |
3072d30e | 2480 | /* Const functions cannot do anything bad i.e. read memory, |
17e1318c | 2481 | however, they can read their parameters which may have |
aa140b76 | 2482 | been pushed onto the stack. |
2483 | memset and bzero don't read memory either. */ | |
2484 | const_call = RTL_CONST_CALL_P (insn); | |
2485 | if (!const_call) | |
2486 | { | |
cf7fb72d | 2487 | rtx call = get_call_rtx_from (insn); |
2488 | if (call && GET_CODE (XEXP (XEXP (call, 0), 0)) == SYMBOL_REF) | |
aa140b76 | 2489 | { |
2490 | rtx symbol = XEXP (XEXP (call, 0), 0); | |
2491 | if (SYMBOL_REF_DECL (symbol) | |
2492 | && TREE_CODE (SYMBOL_REF_DECL (symbol)) == FUNCTION_DECL) | |
2493 | { | |
2494 | if ((DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (symbol)) | |
2495 | == BUILT_IN_NORMAL | |
2496 | && (DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol)) | |
2497 | == BUILT_IN_MEMSET)) | |
2498 | || SYMBOL_REF_DECL (symbol) == block_clear_fn) | |
2499 | memset_call = SYMBOL_REF_DECL (symbol); | |
2500 | } | |
2501 | } | |
2502 | } | |
2503 | if (const_call || memset_call) | |
3072d30e | 2504 | { |
2505 | insn_info_t i_ptr = active_local_stores; | |
2506 | insn_info_t last = NULL; | |
2507 | ||
1ca59310 | 2508 | if (dump_file && (dump_flags & TDF_DETAILS)) |
aa140b76 | 2509 | fprintf (dump_file, "%s call %d\n", |
2510 | const_call ? "const" : "memset", INSN_UID (insn)); | |
3072d30e | 2511 | |
16bf64db | 2512 | /* See the head comment of the frame_read field. */ |
17853422 | 2513 | if (reload_completed |
2514 | /* Tail calls are storing their arguments using | |
2515 | arg pointer. If it is a frame pointer on the target, | |
2516 | even before reload we need to kill frame pointer based | |
2517 | stores. */ | |
2518 | || (SIBLING_CALL_P (insn) | |
2519 | && HARD_FRAME_POINTER_IS_ARG_POINTER)) | |
16bf64db | 2520 | insn_info->frame_read = true; |
2521 | ||
2522 | /* Loop over the active stores and remove those which are | |
2523 | killed by the const function call. */ | |
3072d30e | 2524 | while (i_ptr) |
2525 | { | |
16bf64db | 2526 | bool remove_store = false; |
2527 | ||
2528 | /* The stack pointer based stores are always killed. */ | |
17e1318c | 2529 | if (i_ptr->stack_pointer_based) |
16bf64db | 2530 | remove_store = true; |
2531 | ||
2532 | /* If the frame is read, the frame related stores are killed. */ | |
2533 | else if (insn_info->frame_read) | |
2534 | { | |
2535 | store_info_t store_info = i_ptr->store_rec; | |
2536 | ||
2537 | /* Skip the clobbers. */ | |
2538 | while (!store_info->is_set) | |
2539 | store_info = store_info->next; | |
2540 | ||
2541 | if (store_info->group_id >= 0 | |
f1f41a6c | 2542 | && rtx_group_vec[store_info->group_id]->frame_related) |
16bf64db | 2543 | remove_store = true; |
2544 | } | |
2545 | ||
2546 | if (remove_store) | |
3072d30e | 2547 | { |
1ca59310 | 2548 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2549 | dump_insn_info ("removing from active", i_ptr); |
48e1416a | 2550 | |
1242bee6 | 2551 | active_local_stores_len--; |
3072d30e | 2552 | if (last) |
2553 | last->next_local_store = i_ptr->next_local_store; | |
2554 | else | |
2555 | active_local_stores = i_ptr->next_local_store; | |
2556 | } | |
2557 | else | |
2558 | last = i_ptr; | |
16bf64db | 2559 | |
3072d30e | 2560 | i_ptr = i_ptr->next_local_store; |
2561 | } | |
aa140b76 | 2562 | |
2563 | if (memset_call) | |
2564 | { | |
2565 | rtx args[3]; | |
2566 | if (get_call_args (insn, memset_call, args, 3) | |
2567 | && CONST_INT_P (args[1]) | |
2568 | && CONST_INT_P (args[2]) | |
2569 | && INTVAL (args[2]) > 0) | |
2570 | { | |
2571 | rtx mem = gen_rtx_MEM (BLKmode, args[0]); | |
5b2a69fa | 2572 | set_mem_size (mem, INTVAL (args[2])); |
d1f9b275 | 2573 | body = gen_rtx_SET (mem, args[1]); |
aa140b76 | 2574 | mems_found += record_store (body, bb_info); |
1ca59310 | 2575 | if (dump_file && (dump_flags & TDF_DETAILS)) |
aa140b76 | 2576 | fprintf (dump_file, "handling memset as BLKmode store\n"); |
2577 | if (mems_found == 1) | |
2578 | { | |
1242bee6 | 2579 | if (active_local_stores_len++ |
2580 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2581 | { | |
2582 | active_local_stores_len = 1; | |
2583 | active_local_stores = NULL; | |
2584 | } | |
5a9ecd4a | 2585 | insn_info->fixed_regs_live |
2586 | = copy_fixed_regs (bb_info->regs_live); | |
aa140b76 | 2587 | insn_info->next_local_store = active_local_stores; |
2588 | active_local_stores = insn_info; | |
2589 | } | |
2590 | } | |
2591 | } | |
3072d30e | 2592 | } |
17853422 | 2593 | else if (SIBLING_CALL_P (insn) && reload_completed) |
2594 | /* Arguments for a sibling call that are pushed to memory are passed | |
2595 | using the incoming argument pointer of the current function. After | |
2596 | reload that might be (and likely is) frame pointer based. */ | |
2597 | add_wild_read (bb_info); | |
17e1318c | 2598 | else |
b4a708fb | 2599 | /* Every other call, including pure functions, may read any memory |
2600 | that is not relative to the frame. */ | |
2601 | add_non_frame_wild_read (bb_info); | |
17e1318c | 2602 | |
3072d30e | 2603 | return; |
2604 | } | |
2605 | ||
2606 | /* Assuming that there are sets in these insns, we cannot delete | |
2607 | them. */ | |
2608 | if ((GET_CODE (PATTERN (insn)) == CLOBBER) | |
4aafe72f | 2609 | || volatile_refs_p (PATTERN (insn)) |
bc0dfc8d | 2610 | || (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) |
3072d30e | 2611 | || (RTX_FRAME_RELATED_P (insn)) |
2612 | || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX)) | |
2613 | insn_info->cannot_delete = true; | |
48e1416a | 2614 | |
3072d30e | 2615 | body = PATTERN (insn); |
2616 | if (GET_CODE (body) == PARALLEL) | |
2617 | { | |
2618 | int i; | |
2619 | for (i = 0; i < XVECLEN (body, 0); i++) | |
2620 | mems_found += record_store (XVECEXP (body, 0, i), bb_info); | |
2621 | } | |
2622 | else | |
2623 | mems_found += record_store (body, bb_info); | |
2624 | ||
1ca59310 | 2625 | if (dump_file && (dump_flags & TDF_DETAILS)) |
48e1416a | 2626 | fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n", |
3072d30e | 2627 | mems_found, insn_info->cannot_delete ? "true" : "false"); |
2628 | ||
aa140b76 | 2629 | /* If we found some sets of mems, add it into the active_local_stores so |
2630 | that it can be locally deleted if found dead or used for | |
2631 | replace_read and redundant constant store elimination. Otherwise mark | |
2632 | it as cannot delete. This simplifies the processing later. */ | |
2633 | if (mems_found == 1) | |
3072d30e | 2634 | { |
1242bee6 | 2635 | if (active_local_stores_len++ |
2636 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2637 | { | |
2638 | active_local_stores_len = 1; | |
2639 | active_local_stores = NULL; | |
2640 | } | |
5a9ecd4a | 2641 | insn_info->fixed_regs_live = copy_fixed_regs (bb_info->regs_live); |
3072d30e | 2642 | insn_info->next_local_store = active_local_stores; |
2643 | active_local_stores = insn_info; | |
2644 | } | |
2645 | else | |
2646 | insn_info->cannot_delete = true; | |
2647 | } | |
2648 | ||
2649 | ||
2650 | /* Remove BASE from the set of active_local_stores. This is a | |
2651 | callback from cselib that is used to get rid of the stores in | |
2652 | active_local_stores. */ | |
2653 | ||
2654 | static void | |
2655 | remove_useless_values (cselib_val *base) | |
2656 | { | |
2657 | insn_info_t insn_info = active_local_stores; | |
2658 | insn_info_t last = NULL; | |
2659 | ||
2660 | while (insn_info) | |
2661 | { | |
2662 | store_info_t store_info = insn_info->store_rec; | |
9ce37fa7 | 2663 | bool del = false; |
3072d30e | 2664 | |
2665 | /* If ANY of the store_infos match the cselib group that is | |
2666 | being deleted, then the insn can not be deleted. */ | |
2667 | while (store_info) | |
2668 | { | |
48e1416a | 2669 | if ((store_info->group_id == -1) |
3072d30e | 2670 | && (store_info->cse_base == base)) |
2671 | { | |
9ce37fa7 | 2672 | del = true; |
3072d30e | 2673 | break; |
2674 | } | |
2675 | store_info = store_info->next; | |
2676 | } | |
2677 | ||
9ce37fa7 | 2678 | if (del) |
3072d30e | 2679 | { |
1242bee6 | 2680 | active_local_stores_len--; |
3072d30e | 2681 | if (last) |
2682 | last->next_local_store = insn_info->next_local_store; | |
2683 | else | |
2684 | active_local_stores = insn_info->next_local_store; | |
2685 | free_store_info (insn_info); | |
2686 | } | |
2687 | else | |
2688 | last = insn_info; | |
48e1416a | 2689 | |
3072d30e | 2690 | insn_info = insn_info->next_local_store; |
2691 | } | |
2692 | } | |
2693 | ||
2694 | ||
2695 | /* Do all of step 1. */ | |
2696 | ||
2697 | static void | |
2698 | dse_step1 (void) | |
2699 | { | |
2700 | basic_block bb; | |
4fb07d00 | 2701 | bitmap regs_live = BITMAP_ALLOC (®_obstack); |
48e1416a | 2702 | |
35af0188 | 2703 | cselib_init (0); |
3072d30e | 2704 | all_blocks = BITMAP_ALLOC (NULL); |
2705 | bitmap_set_bit (all_blocks, ENTRY_BLOCK); | |
2706 | bitmap_set_bit (all_blocks, EXIT_BLOCK); | |
2707 | ||
ed7d889a | 2708 | FOR_ALL_BB_FN (bb, cfun) |
3072d30e | 2709 | { |
2710 | insn_info_t ptr; | |
e16712b1 | 2711 | bb_info_t bb_info = dse_bb_info_type_pool.allocate (); |
3072d30e | 2712 | |
55c5ac9f | 2713 | memset (bb_info, 0, sizeof (dse_bb_info_type)); |
3072d30e | 2714 | bitmap_set_bit (all_blocks, bb->index); |
a1b0a968 | 2715 | bb_info->regs_live = regs_live; |
2716 | ||
2717 | bitmap_copy (regs_live, DF_LR_IN (bb)); | |
2718 | df_simulate_initialize_forwards (bb, regs_live); | |
3072d30e | 2719 | |
2720 | bb_table[bb->index] = bb_info; | |
2721 | cselib_discard_hook = remove_useless_values; | |
2722 | ||
2723 | if (bb->index >= NUM_FIXED_BLOCKS) | |
2724 | { | |
ebabb7a3 | 2725 | rtx_insn *insn; |
3072d30e | 2726 | |
3072d30e | 2727 | active_local_stores = NULL; |
1242bee6 | 2728 | active_local_stores_len = 0; |
3072d30e | 2729 | cselib_clear_table (); |
48e1416a | 2730 | |
3072d30e | 2731 | /* Scan the insns. */ |
2732 | FOR_BB_INSNS (bb, insn) | |
2733 | { | |
2734 | if (INSN_P (insn)) | |
2735 | scan_insn (bb_info, insn); | |
2736 | cselib_process_insn (insn); | |
a1b0a968 | 2737 | if (INSN_P (insn)) |
2738 | df_simulate_one_insn_forwards (bb, insn, regs_live); | |
3072d30e | 2739 | } |
48e1416a | 2740 | |
3072d30e | 2741 | /* This is something of a hack, because the global algorithm |
2742 | is supposed to take care of the case where stores go dead | |
2743 | at the end of the function. However, the global | |
2744 | algorithm must take a more conservative view of block | |
2745 | mode reads than the local alg does. So to get the case | |
2746 | where you have a store to the frame followed by a non | |
bef304b8 | 2747 | overlapping block more read, we look at the active local |
3072d30e | 2748 | stores at the end of the function and delete all of the |
2749 | frame and spill based ones. */ | |
2750 | if (stores_off_frame_dead_at_return | |
2751 | && (EDGE_COUNT (bb->succs) == 0 | |
2752 | || (single_succ_p (bb) | |
34154e27 | 2753 | && single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (cfun) |
18d50ae6 | 2754 | && ! crtl->calls_eh_return))) |
3072d30e | 2755 | { |
2756 | insn_info_t i_ptr = active_local_stores; | |
2757 | while (i_ptr) | |
2758 | { | |
2759 | store_info_t store_info = i_ptr->store_rec; | |
2760 | ||
2761 | /* Skip the clobbers. */ | |
2762 | while (!store_info->is_set) | |
2763 | store_info = store_info->next; | |
aa140b76 | 2764 | if (store_info->alias_set && !i_ptr->cannot_delete) |
3072d30e | 2765 | delete_dead_store_insn (i_ptr); |
48e1416a | 2766 | else |
3072d30e | 2767 | if (store_info->group_id >= 0) |
2768 | { | |
48e1416a | 2769 | group_info_t group |
f1f41a6c | 2770 | = rtx_group_vec[store_info->group_id]; |
aa140b76 | 2771 | if (group->frame_related && !i_ptr->cannot_delete) |
3072d30e | 2772 | delete_dead_store_insn (i_ptr); |
2773 | } | |
2774 | ||
2775 | i_ptr = i_ptr->next_local_store; | |
2776 | } | |
2777 | } | |
2778 | ||
2779 | /* Get rid of the loads that were discovered in | |
2780 | replace_read. Cselib is finished with this block. */ | |
2781 | while (deferred_change_list) | |
2782 | { | |
2783 | deferred_change_t next = deferred_change_list->next; | |
2784 | ||
2785 | /* There is no reason to validate this change. That was | |
2786 | done earlier. */ | |
2787 | *deferred_change_list->loc = deferred_change_list->reg; | |
e16712b1 | 2788 | deferred_change_pool.remove (deferred_change_list); |
3072d30e | 2789 | deferred_change_list = next; |
2790 | } | |
2791 | ||
2792 | /* Get rid of all of the cselib based store_infos in this | |
2793 | block and mark the containing insns as not being | |
2794 | deletable. */ | |
2795 | ptr = bb_info->last_insn; | |
2796 | while (ptr) | |
2797 | { | |
2798 | if (ptr->contains_cselib_groups) | |
aa140b76 | 2799 | { |
2800 | store_info_t s_info = ptr->store_rec; | |
2801 | while (s_info && !s_info->is_set) | |
2802 | s_info = s_info->next; | |
2803 | if (s_info | |
2804 | && s_info->redundant_reason | |
2805 | && s_info->redundant_reason->insn | |
2806 | && !ptr->cannot_delete) | |
2807 | { | |
1ca59310 | 2808 | if (dump_file && (dump_flags & TDF_DETAILS)) |
aa140b76 | 2809 | fprintf (dump_file, "Locally deleting insn %d " |
2810 | "because insn %d stores the " | |
2811 | "same value and couldn't be " | |
2812 | "eliminated\n", | |
2813 | INSN_UID (ptr->insn), | |
2814 | INSN_UID (s_info->redundant_reason->insn)); | |
2815 | delete_dead_store_insn (ptr); | |
2816 | } | |
aa140b76 | 2817 | free_store_info (ptr); |
2818 | } | |
2819 | else | |
2820 | { | |
2821 | store_info_t s_info; | |
2822 | ||
2823 | /* Free at least positions_needed bitmaps. */ | |
2824 | for (s_info = ptr->store_rec; s_info; s_info = s_info->next) | |
2825 | if (s_info->is_large) | |
2826 | { | |
843bd2fa | 2827 | BITMAP_FREE (s_info->positions_needed.large.bmap); |
aa140b76 | 2828 | s_info->is_large = false; |
2829 | } | |
2830 | } | |
3072d30e | 2831 | ptr = ptr->prev_insn; |
2832 | } | |
2833 | ||
55c5ac9f | 2834 | cse_store_info_pool.release (); |
3072d30e | 2835 | } |
a1b0a968 | 2836 | bb_info->regs_live = NULL; |
3072d30e | 2837 | } |
2838 | ||
a1b0a968 | 2839 | BITMAP_FREE (regs_live); |
3072d30e | 2840 | cselib_finish (); |
c1f445d2 | 2841 | rtx_group_table->empty (); |
3072d30e | 2842 | } |
2843 | ||
2844 | \f | |
2845 | /*---------------------------------------------------------------------------- | |
2846 | Second step. | |
2847 | ||
2848 | Assign each byte position in the stores that we are going to | |
2849 | analyze globally to a position in the bitmaps. Returns true if | |
6dfdc153 | 2850 | there are any bit positions assigned. |
3072d30e | 2851 | ----------------------------------------------------------------------------*/ |
2852 | ||
2853 | static void | |
2854 | dse_step2_init (void) | |
2855 | { | |
2856 | unsigned int i; | |
2857 | group_info_t group; | |
2858 | ||
f1f41a6c | 2859 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
3072d30e | 2860 | { |
2861 | /* For all non stack related bases, we only consider a store to | |
2862 | be deletable if there are two or more stores for that | |
2863 | position. This is because it takes one store to make the | |
2864 | other store redundant. However, for the stores that are | |
2865 | stack related, we consider them if there is only one store | |
2866 | for the position. We do this because the stack related | |
2867 | stores can be deleted if their is no read between them and | |
2868 | the end of the function. | |
48e1416a | 2869 | |
3072d30e | 2870 | To make this work in the current framework, we take the stack |
2871 | related bases add all of the bits from store1 into store2. | |
2872 | This has the effect of making the eligible even if there is | |
2873 | only one store. */ | |
2874 | ||
2875 | if (stores_off_frame_dead_at_return && group->frame_related) | |
2876 | { | |
2877 | bitmap_ior_into (group->store2_n, group->store1_n); | |
2878 | bitmap_ior_into (group->store2_p, group->store1_p); | |
1ca59310 | 2879 | if (dump_file && (dump_flags & TDF_DETAILS)) |
48e1416a | 2880 | fprintf (dump_file, "group %d is frame related ", i); |
3072d30e | 2881 | } |
2882 | ||
2883 | group->offset_map_size_n++; | |
4fb07d00 | 2884 | group->offset_map_n = XOBNEWVEC (&dse_obstack, int, |
2885 | group->offset_map_size_n); | |
3072d30e | 2886 | group->offset_map_size_p++; |
4fb07d00 | 2887 | group->offset_map_p = XOBNEWVEC (&dse_obstack, int, |
2888 | group->offset_map_size_p); | |
3072d30e | 2889 | group->process_globally = false; |
1ca59310 | 2890 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2891 | { |
48e1416a | 2892 | fprintf (dump_file, "group %d(%d+%d): ", i, |
3072d30e | 2893 | (int)bitmap_count_bits (group->store2_n), |
2894 | (int)bitmap_count_bits (group->store2_p)); | |
2895 | bitmap_print (dump_file, group->store2_n, "n ", " "); | |
2896 | bitmap_print (dump_file, group->store2_p, "p ", "\n"); | |
2897 | } | |
2898 | } | |
2899 | } | |
2900 | ||
2901 | ||
2902 | /* Init the offset tables for the normal case. */ | |
2903 | ||
2904 | static bool | |
2905 | dse_step2_nospill (void) | |
2906 | { | |
2907 | unsigned int i; | |
2908 | group_info_t group; | |
2909 | /* Position 0 is unused because 0 is used in the maps to mean | |
2910 | unused. */ | |
2911 | current_position = 1; | |
f1f41a6c | 2912 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
3072d30e | 2913 | { |
2914 | bitmap_iterator bi; | |
2915 | unsigned int j; | |
2916 | ||
2917 | if (group == clear_alias_group) | |
2918 | continue; | |
2919 | ||
9af5ce0c | 2920 | memset (group->offset_map_n, 0, sizeof (int) * group->offset_map_size_n); |
2921 | memset (group->offset_map_p, 0, sizeof (int) * group->offset_map_size_p); | |
3072d30e | 2922 | bitmap_clear (group->group_kill); |
2923 | ||
2924 | EXECUTE_IF_SET_IN_BITMAP (group->store2_n, 0, j, bi) | |
2925 | { | |
2926 | bitmap_set_bit (group->group_kill, current_position); | |
b4a708fb | 2927 | if (bitmap_bit_p (group->escaped_n, j)) |
2928 | bitmap_set_bit (kill_on_calls, current_position); | |
3072d30e | 2929 | group->offset_map_n[j] = current_position++; |
2930 | group->process_globally = true; | |
2931 | } | |
2932 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2933 | { | |
48e1416a | 2934 | bitmap_set_bit (group->group_kill, current_position); |
b4a708fb | 2935 | if (bitmap_bit_p (group->escaped_p, j)) |
2936 | bitmap_set_bit (kill_on_calls, current_position); | |
3072d30e | 2937 | group->offset_map_p[j] = current_position++; |
2938 | group->process_globally = true; | |
2939 | } | |
2940 | } | |
2941 | return current_position != 1; | |
2942 | } | |
2943 | ||
2944 | ||
3072d30e | 2945 | \f |
2946 | /*---------------------------------------------------------------------------- | |
2947 | Third step. | |
48e1416a | 2948 | |
3072d30e | 2949 | Build the bit vectors for the transfer functions. |
2950 | ----------------------------------------------------------------------------*/ | |
2951 | ||
2952 | ||
3072d30e | 2953 | /* Look up the bitmap index for OFFSET in GROUP_INFO. If it is not |
2954 | there, return 0. */ | |
2955 | ||
2956 | static int | |
2957 | get_bitmap_index (group_info_t group_info, HOST_WIDE_INT offset) | |
2958 | { | |
2959 | if (offset < 0) | |
2960 | { | |
2961 | HOST_WIDE_INT offset_p = -offset; | |
2962 | if (offset_p >= group_info->offset_map_size_n) | |
2963 | return 0; | |
2964 | return group_info->offset_map_n[offset_p]; | |
2965 | } | |
2966 | else | |
2967 | { | |
2968 | if (offset >= group_info->offset_map_size_p) | |
2969 | return 0; | |
2970 | return group_info->offset_map_p[offset]; | |
2971 | } | |
2972 | } | |
2973 | ||
2974 | ||
2975 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
2976 | may be NULL. */ | |
2977 | ||
48e1416a | 2978 | static void |
3072d30e | 2979 | scan_stores_nospill (store_info_t store_info, bitmap gen, bitmap kill) |
2980 | { | |
2981 | while (store_info) | |
2982 | { | |
2983 | HOST_WIDE_INT i; | |
48e1416a | 2984 | group_info_t group_info |
f1f41a6c | 2985 | = rtx_group_vec[store_info->group_id]; |
3072d30e | 2986 | if (group_info->process_globally) |
2987 | for (i = store_info->begin; i < store_info->end; i++) | |
2988 | { | |
2989 | int index = get_bitmap_index (group_info, i); | |
2990 | if (index != 0) | |
2991 | { | |
2992 | bitmap_set_bit (gen, index); | |
2993 | if (kill) | |
2994 | bitmap_clear_bit (kill, index); | |
2995 | } | |
2996 | } | |
2997 | store_info = store_info->next; | |
2998 | } | |
2999 | } | |
3000 | ||
3001 | ||
3002 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
3003 | may be NULL. */ | |
3004 | ||
48e1416a | 3005 | static void |
3072d30e | 3006 | scan_stores_spill (store_info_t store_info, bitmap gen, bitmap kill) |
3007 | { | |
3008 | while (store_info) | |
3009 | { | |
3010 | if (store_info->alias_set) | |
3011 | { | |
48e1416a | 3012 | int index = get_bitmap_index (clear_alias_group, |
3072d30e | 3013 | store_info->alias_set); |
3014 | if (index != 0) | |
3015 | { | |
3016 | bitmap_set_bit (gen, index); | |
3017 | if (kill) | |
3018 | bitmap_clear_bit (kill, index); | |
3019 | } | |
3020 | } | |
3021 | store_info = store_info->next; | |
3022 | } | |
3023 | } | |
3024 | ||
3025 | ||
3026 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3027 | may be NULL. */ | |
3028 | ||
3029 | static void | |
3030 | scan_reads_nospill (insn_info_t insn_info, bitmap gen, bitmap kill) | |
3031 | { | |
3032 | read_info_t read_info = insn_info->read_rec; | |
3033 | int i; | |
3034 | group_info_t group; | |
3035 | ||
16bf64db | 3036 | /* If this insn reads the frame, kill all the frame related stores. */ |
3037 | if (insn_info->frame_read) | |
3038 | { | |
f1f41a6c | 3039 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
16bf64db | 3040 | if (group->process_globally && group->frame_related) |
3041 | { | |
3042 | if (kill) | |
3043 | bitmap_ior_into (kill, group->group_kill); | |
48e1416a | 3044 | bitmap_and_compl_into (gen, group->group_kill); |
16bf64db | 3045 | } |
3046 | } | |
b4a708fb | 3047 | if (insn_info->non_frame_wild_read) |
3048 | { | |
3049 | /* Kill all non-frame related stores. Kill all stores of variables that | |
3050 | escape. */ | |
3051 | if (kill) | |
3052 | bitmap_ior_into (kill, kill_on_calls); | |
3053 | bitmap_and_compl_into (gen, kill_on_calls); | |
f1f41a6c | 3054 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
b4a708fb | 3055 | if (group->process_globally && !group->frame_related) |
3056 | { | |
3057 | if (kill) | |
3058 | bitmap_ior_into (kill, group->group_kill); | |
3059 | bitmap_and_compl_into (gen, group->group_kill); | |
3060 | } | |
3061 | } | |
3072d30e | 3062 | while (read_info) |
3063 | { | |
f1f41a6c | 3064 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
3072d30e | 3065 | { |
3066 | if (group->process_globally) | |
3067 | { | |
3068 | if (i == read_info->group_id) | |
3069 | { | |
3070 | if (read_info->begin > read_info->end) | |
3071 | { | |
3072 | /* Begin > end for block mode reads. */ | |
3073 | if (kill) | |
3074 | bitmap_ior_into (kill, group->group_kill); | |
3075 | bitmap_and_compl_into (gen, group->group_kill); | |
3076 | } | |
3077 | else | |
3078 | { | |
3079 | /* The groups are the same, just process the | |
3080 | offsets. */ | |
3081 | HOST_WIDE_INT j; | |
3082 | for (j = read_info->begin; j < read_info->end; j++) | |
3083 | { | |
3084 | int index = get_bitmap_index (group, j); | |
3085 | if (index != 0) | |
3086 | { | |
3087 | if (kill) | |
3088 | bitmap_set_bit (kill, index); | |
3089 | bitmap_clear_bit (gen, index); | |
3090 | } | |
3091 | } | |
3092 | } | |
3093 | } | |
3094 | else | |
3095 | { | |
3096 | /* The groups are different, if the alias sets | |
3097 | conflict, clear the entire group. We only need | |
3098 | to apply this test if the read_info is a cselib | |
3099 | read. Anything with a constant base cannot alias | |
3100 | something else with a different constant | |
3101 | base. */ | |
3102 | if ((read_info->group_id < 0) | |
48e1416a | 3103 | && canon_true_dependence (group->base_mem, |
ec410bf1 | 3104 | GET_MODE (group->base_mem), |
82d2c88b | 3105 | group->canon_base_addr, |
376a287d | 3106 | read_info->mem, NULL_RTX)) |
3072d30e | 3107 | { |
3108 | if (kill) | |
3109 | bitmap_ior_into (kill, group->group_kill); | |
3110 | bitmap_and_compl_into (gen, group->group_kill); | |
3111 | } | |
3112 | } | |
3113 | } | |
3114 | } | |
48e1416a | 3115 | |
3072d30e | 3116 | read_info = read_info->next; |
3117 | } | |
3118 | } | |
3119 | ||
3120 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3121 | may be NULL. */ | |
3122 | ||
3123 | static void | |
3124 | scan_reads_spill (read_info_t read_info, bitmap gen, bitmap kill) | |
3125 | { | |
3126 | while (read_info) | |
3127 | { | |
3128 | if (read_info->alias_set) | |
3129 | { | |
48e1416a | 3130 | int index = get_bitmap_index (clear_alias_group, |
3072d30e | 3131 | read_info->alias_set); |
3132 | if (index != 0) | |
3133 | { | |
3134 | if (kill) | |
3135 | bitmap_set_bit (kill, index); | |
3136 | bitmap_clear_bit (gen, index); | |
3137 | } | |
3138 | } | |
48e1416a | 3139 | |
3072d30e | 3140 | read_info = read_info->next; |
3141 | } | |
3142 | } | |
3143 | ||
3144 | ||
3145 | /* Return the insn in BB_INFO before the first wild read or if there | |
3146 | are no wild reads in the block, return the last insn. */ | |
3147 | ||
3148 | static insn_info_t | |
3149 | find_insn_before_first_wild_read (bb_info_t bb_info) | |
3150 | { | |
3151 | insn_info_t insn_info = bb_info->last_insn; | |
3152 | insn_info_t last_wild_read = NULL; | |
3153 | ||
3154 | while (insn_info) | |
3155 | { | |
3156 | if (insn_info->wild_read) | |
3157 | { | |
3158 | last_wild_read = insn_info->prev_insn; | |
3159 | /* Block starts with wild read. */ | |
3160 | if (!last_wild_read) | |
3161 | return NULL; | |
3162 | } | |
3163 | ||
3164 | insn_info = insn_info->prev_insn; | |
3165 | } | |
3166 | ||
3167 | if (last_wild_read) | |
3168 | return last_wild_read; | |
3169 | else | |
3170 | return bb_info->last_insn; | |
3171 | } | |
3172 | ||
3173 | ||
3174 | /* Scan the insns in BB_INFO starting at PTR and going to the top of | |
3175 | the block in order to build the gen and kill sets for the block. | |
3176 | We start at ptr which may be the last insn in the block or may be | |
3177 | the first insn with a wild read. In the latter case we are able to | |
3178 | skip the rest of the block because it just does not matter: | |
3179 | anything that happens is hidden by the wild read. */ | |
3180 | ||
3181 | static void | |
3182 | dse_step3_scan (bool for_spills, basic_block bb) | |
3183 | { | |
3184 | bb_info_t bb_info = bb_table[bb->index]; | |
3185 | insn_info_t insn_info; | |
3186 | ||
3187 | if (for_spills) | |
3188 | /* There are no wild reads in the spill case. */ | |
3189 | insn_info = bb_info->last_insn; | |
3190 | else | |
3191 | insn_info = find_insn_before_first_wild_read (bb_info); | |
48e1416a | 3192 | |
3072d30e | 3193 | /* In the spill case or in the no_spill case if there is no wild |
3194 | read in the block, we will need a kill set. */ | |
3195 | if (insn_info == bb_info->last_insn) | |
3196 | { | |
3197 | if (bb_info->kill) | |
3198 | bitmap_clear (bb_info->kill); | |
3199 | else | |
4fb07d00 | 3200 | bb_info->kill = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3201 | } |
48e1416a | 3202 | else |
3072d30e | 3203 | if (bb_info->kill) |
3204 | BITMAP_FREE (bb_info->kill); | |
3205 | ||
3206 | while (insn_info) | |
3207 | { | |
3208 | /* There may have been code deleted by the dce pass run before | |
3209 | this phase. */ | |
3210 | if (insn_info->insn && INSN_P (insn_info->insn)) | |
3211 | { | |
48e1416a | 3212 | /* Process the read(s) last. */ |
3072d30e | 3213 | if (for_spills) |
3214 | { | |
3215 | scan_stores_spill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3216 | scan_reads_spill (insn_info->read_rec, bb_info->gen, bb_info->kill); | |
3217 | } | |
3218 | else | |
3219 | { | |
3220 | scan_stores_nospill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3221 | scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill); | |
3222 | } | |
48e1416a | 3223 | } |
3072d30e | 3224 | |
3225 | insn_info = insn_info->prev_insn; | |
3226 | } | |
3227 | } | |
3228 | ||
3229 | ||
3230 | /* Set the gen set of the exit block, and also any block with no | |
3231 | successors that does not have a wild read. */ | |
3232 | ||
3233 | static void | |
3234 | dse_step3_exit_block_scan (bb_info_t bb_info) | |
3235 | { | |
3236 | /* The gen set is all 0's for the exit block except for the | |
3237 | frame_pointer_group. */ | |
48e1416a | 3238 | |
3072d30e | 3239 | if (stores_off_frame_dead_at_return) |
3240 | { | |
3241 | unsigned int i; | |
3242 | group_info_t group; | |
48e1416a | 3243 | |
f1f41a6c | 3244 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
3072d30e | 3245 | { |
3246 | if (group->process_globally && group->frame_related) | |
3247 | bitmap_ior_into (bb_info->gen, group->group_kill); | |
3248 | } | |
3249 | } | |
3250 | } | |
3251 | ||
3252 | ||
3253 | /* Find all of the blocks that are not backwards reachable from the | |
3254 | exit block or any block with no successors (BB). These are the | |
3255 | infinite loops or infinite self loops. These blocks will still | |
3256 | have their bits set in UNREACHABLE_BLOCKS. */ | |
3257 | ||
3258 | static void | |
3259 | mark_reachable_blocks (sbitmap unreachable_blocks, basic_block bb) | |
3260 | { | |
3261 | edge e; | |
3262 | edge_iterator ei; | |
3263 | ||
08b7917c | 3264 | if (bitmap_bit_p (unreachable_blocks, bb->index)) |
3072d30e | 3265 | { |
08b7917c | 3266 | bitmap_clear_bit (unreachable_blocks, bb->index); |
3072d30e | 3267 | FOR_EACH_EDGE (e, ei, bb->preds) |
48e1416a | 3268 | { |
3072d30e | 3269 | mark_reachable_blocks (unreachable_blocks, e->src); |
48e1416a | 3270 | } |
3072d30e | 3271 | } |
3272 | } | |
3273 | ||
3274 | /* Build the transfer functions for the function. */ | |
3275 | ||
3276 | static void | |
3277 | dse_step3 (bool for_spills) | |
3278 | { | |
3279 | basic_block bb; | |
fe672ac0 | 3280 | sbitmap unreachable_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
3072d30e | 3281 | sbitmap_iterator sbi; |
3282 | bitmap all_ones = NULL; | |
3283 | unsigned int i; | |
48e1416a | 3284 | |
53c5d9d4 | 3285 | bitmap_ones (unreachable_blocks); |
3072d30e | 3286 | |
ed7d889a | 3287 | FOR_ALL_BB_FN (bb, cfun) |
3072d30e | 3288 | { |
3289 | bb_info_t bb_info = bb_table[bb->index]; | |
3290 | if (bb_info->gen) | |
3291 | bitmap_clear (bb_info->gen); | |
3292 | else | |
4fb07d00 | 3293 | bb_info->gen = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3294 | |
3295 | if (bb->index == ENTRY_BLOCK) | |
3296 | ; | |
3297 | else if (bb->index == EXIT_BLOCK) | |
3298 | dse_step3_exit_block_scan (bb_info); | |
3299 | else | |
3300 | dse_step3_scan (for_spills, bb); | |
3301 | if (EDGE_COUNT (bb->succs) == 0) | |
3302 | mark_reachable_blocks (unreachable_blocks, bb); | |
3303 | ||
3304 | /* If this is the second time dataflow is run, delete the old | |
3305 | sets. */ | |
3306 | if (bb_info->in) | |
3307 | BITMAP_FREE (bb_info->in); | |
3308 | if (bb_info->out) | |
3309 | BITMAP_FREE (bb_info->out); | |
3310 | } | |
3311 | ||
3312 | /* For any block in an infinite loop, we must initialize the out set | |
3313 | to all ones. This could be expensive, but almost never occurs in | |
3314 | practice. However, it is common in regression tests. */ | |
0d211963 | 3315 | EXECUTE_IF_SET_IN_BITMAP (unreachable_blocks, 0, i, sbi) |
3072d30e | 3316 | { |
3317 | if (bitmap_bit_p (all_blocks, i)) | |
3318 | { | |
3319 | bb_info_t bb_info = bb_table[i]; | |
3320 | if (!all_ones) | |
3321 | { | |
3322 | unsigned int j; | |
3323 | group_info_t group; | |
3324 | ||
4fb07d00 | 3325 | all_ones = BITMAP_ALLOC (&dse_bitmap_obstack); |
f1f41a6c | 3326 | FOR_EACH_VEC_ELT (rtx_group_vec, j, group) |
3072d30e | 3327 | bitmap_ior_into (all_ones, group->group_kill); |
3328 | } | |
3329 | if (!bb_info->out) | |
3330 | { | |
4fb07d00 | 3331 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3332 | bitmap_copy (bb_info->out, all_ones); |
3333 | } | |
3334 | } | |
3335 | } | |
3336 | ||
3337 | if (all_ones) | |
3338 | BITMAP_FREE (all_ones); | |
3339 | sbitmap_free (unreachable_blocks); | |
3340 | } | |
3341 | ||
3342 | ||
3343 | \f | |
3344 | /*---------------------------------------------------------------------------- | |
3345 | Fourth step. | |
3346 | ||
3347 | Solve the bitvector equations. | |
3348 | ----------------------------------------------------------------------------*/ | |
3349 | ||
3350 | ||
3351 | /* Confluence function for blocks with no successors. Create an out | |
3352 | set from the gen set of the exit block. This block logically has | |
3353 | the exit block as a successor. */ | |
3354 | ||
3355 | ||
3356 | ||
3357 | static void | |
3358 | dse_confluence_0 (basic_block bb) | |
3359 | { | |
3360 | bb_info_t bb_info = bb_table[bb->index]; | |
3361 | ||
3362 | if (bb->index == EXIT_BLOCK) | |
3363 | return; | |
3364 | ||
3365 | if (!bb_info->out) | |
3366 | { | |
4fb07d00 | 3367 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3368 | bitmap_copy (bb_info->out, bb_table[EXIT_BLOCK]->gen); |
3369 | } | |
3370 | } | |
3371 | ||
3372 | /* Propagate the information from the in set of the dest of E to the | |
3373 | out set of the src of E. If the various in or out sets are not | |
3374 | there, that means they are all ones. */ | |
3375 | ||
a703ca31 | 3376 | static bool |
3072d30e | 3377 | dse_confluence_n (edge e) |
3378 | { | |
3379 | bb_info_t src_info = bb_table[e->src->index]; | |
3380 | bb_info_t dest_info = bb_table[e->dest->index]; | |
3381 | ||
3382 | if (dest_info->in) | |
3383 | { | |
3384 | if (src_info->out) | |
3385 | bitmap_and_into (src_info->out, dest_info->in); | |
3386 | else | |
3387 | { | |
4fb07d00 | 3388 | src_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3389 | bitmap_copy (src_info->out, dest_info->in); |
3390 | } | |
3391 | } | |
a703ca31 | 3392 | return true; |
3072d30e | 3393 | } |
3394 | ||
3395 | ||
3396 | /* Propagate the info from the out to the in set of BB_INDEX's basic | |
48e1416a | 3397 | block. There are three cases: |
3072d30e | 3398 | |
3399 | 1) The block has no kill set. In this case the kill set is all | |
3400 | ones. It does not matter what the out set of the block is, none of | |
3401 | the info can reach the top. The only thing that reaches the top is | |
3402 | the gen set and we just copy the set. | |
3403 | ||
3404 | 2) There is a kill set but no out set and bb has successors. In | |
3405 | this case we just return. Eventually an out set will be created and | |
3406 | it is better to wait than to create a set of ones. | |
3407 | ||
3408 | 3) There is both a kill and out set. We apply the obvious transfer | |
3409 | function. | |
3410 | */ | |
3411 | ||
3412 | static bool | |
3413 | dse_transfer_function (int bb_index) | |
3414 | { | |
3415 | bb_info_t bb_info = bb_table[bb_index]; | |
3416 | ||
3417 | if (bb_info->kill) | |
3418 | { | |
3419 | if (bb_info->out) | |
3420 | { | |
3421 | /* Case 3 above. */ | |
3422 | if (bb_info->in) | |
48e1416a | 3423 | return bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
3072d30e | 3424 | bb_info->out, bb_info->kill); |
3425 | else | |
3426 | { | |
4fb07d00 | 3427 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
48e1416a | 3428 | bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
3072d30e | 3429 | bb_info->out, bb_info->kill); |
3430 | return true; | |
3431 | } | |
3432 | } | |
3433 | else | |
3434 | /* Case 2 above. */ | |
3435 | return false; | |
3436 | } | |
3437 | else | |
3438 | { | |
3439 | /* Case 1 above. If there is already an in set, nothing | |
3440 | happens. */ | |
3441 | if (bb_info->in) | |
3442 | return false; | |
3443 | else | |
3444 | { | |
4fb07d00 | 3445 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3446 | bitmap_copy (bb_info->in, bb_info->gen); |
3447 | return true; | |
3448 | } | |
3449 | } | |
3450 | } | |
3451 | ||
3452 | /* Solve the dataflow equations. */ | |
3453 | ||
3454 | static void | |
3455 | dse_step4 (void) | |
3456 | { | |
48e1416a | 3457 | df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0, |
3458 | dse_confluence_n, dse_transfer_function, | |
3459 | all_blocks, df_get_postorder (DF_BACKWARD), | |
3072d30e | 3460 | df_get_n_blocks (DF_BACKWARD)); |
1ca59310 | 3461 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 3462 | { |
3463 | basic_block bb; | |
3464 | ||
3465 | fprintf (dump_file, "\n\n*** Global dataflow info after analysis.\n"); | |
ed7d889a | 3466 | FOR_ALL_BB_FN (bb, cfun) |
3072d30e | 3467 | { |
3468 | bb_info_t bb_info = bb_table[bb->index]; | |
3469 | ||
3470 | df_print_bb_index (bb, dump_file); | |
3471 | if (bb_info->in) | |
3472 | bitmap_print (dump_file, bb_info->in, " in: ", "\n"); | |
3473 | else | |
3474 | fprintf (dump_file, " in: *MISSING*\n"); | |
3475 | if (bb_info->gen) | |
3476 | bitmap_print (dump_file, bb_info->gen, " gen: ", "\n"); | |
3477 | else | |
3478 | fprintf (dump_file, " gen: *MISSING*\n"); | |
3479 | if (bb_info->kill) | |
3480 | bitmap_print (dump_file, bb_info->kill, " kill: ", "\n"); | |
3481 | else | |
3482 | fprintf (dump_file, " kill: *MISSING*\n"); | |
3483 | if (bb_info->out) | |
3484 | bitmap_print (dump_file, bb_info->out, " out: ", "\n"); | |
3485 | else | |
3486 | fprintf (dump_file, " out: *MISSING*\n\n"); | |
3487 | } | |
3488 | } | |
3489 | } | |
3490 | ||
3491 | ||
3492 | \f | |
3493 | /*---------------------------------------------------------------------------- | |
3494 | Fifth step. | |
3495 | ||
bef304b8 | 3496 | Delete the stores that can only be deleted using the global information. |
3072d30e | 3497 | ----------------------------------------------------------------------------*/ |
3498 | ||
3499 | ||
3500 | static void | |
3501 | dse_step5_nospill (void) | |
3502 | { | |
3503 | basic_block bb; | |
fc00614f | 3504 | FOR_EACH_BB_FN (bb, cfun) |
3072d30e | 3505 | { |
3506 | bb_info_t bb_info = bb_table[bb->index]; | |
3507 | insn_info_t insn_info = bb_info->last_insn; | |
3508 | bitmap v = bb_info->out; | |
3509 | ||
3510 | while (insn_info) | |
3511 | { | |
3512 | bool deleted = false; | |
3513 | if (dump_file && insn_info->insn) | |
3514 | { | |
3515 | fprintf (dump_file, "starting to process insn %d\n", | |
3516 | INSN_UID (insn_info->insn)); | |
3517 | bitmap_print (dump_file, v, " v: ", "\n"); | |
3518 | } | |
3519 | ||
3520 | /* There may have been code deleted by the dce pass run before | |
3521 | this phase. */ | |
48e1416a | 3522 | if (insn_info->insn |
3072d30e | 3523 | && INSN_P (insn_info->insn) |
3524 | && (!insn_info->cannot_delete) | |
3525 | && (!bitmap_empty_p (v))) | |
3526 | { | |
3527 | store_info_t store_info = insn_info->store_rec; | |
3528 | ||
3529 | /* Try to delete the current insn. */ | |
3530 | deleted = true; | |
48e1416a | 3531 | |
3072d30e | 3532 | /* Skip the clobbers. */ |
3533 | while (!store_info->is_set) | |
3534 | store_info = store_info->next; | |
3535 | ||
3536 | if (store_info->alias_set) | |
3537 | deleted = false; | |
3538 | else | |
3539 | { | |
3540 | HOST_WIDE_INT i; | |
48e1416a | 3541 | group_info_t group_info |
f1f41a6c | 3542 | = rtx_group_vec[store_info->group_id]; |
48e1416a | 3543 | |
3072d30e | 3544 | for (i = store_info->begin; i < store_info->end; i++) |
3545 | { | |
3546 | int index = get_bitmap_index (group_info, i); | |
48e1416a | 3547 | |
1ca59310 | 3548 | if (dump_file && (dump_flags & TDF_DETAILS)) |
48e1416a | 3549 | fprintf (dump_file, "i = %d, index = %d\n", (int)i, index); |
3072d30e | 3550 | if (index == 0 || !bitmap_bit_p (v, index)) |
3551 | { | |
1ca59310 | 3552 | if (dump_file && (dump_flags & TDF_DETAILS)) |
48e1416a | 3553 | fprintf (dump_file, "failing at i = %d\n", (int)i); |
3072d30e | 3554 | deleted = false; |
3555 | break; | |
3556 | } | |
3557 | } | |
3558 | } | |
3559 | if (deleted) | |
3560 | { | |
5a9ecd4a | 3561 | if (dbg_cnt (dse) |
3562 | && check_for_inc_dec_1 (insn_info)) | |
3072d30e | 3563 | { |
3072d30e | 3564 | delete_insn (insn_info->insn); |
3565 | insn_info->insn = NULL; | |
3566 | globally_deleted++; | |
3567 | } | |
3568 | } | |
3569 | } | |
3570 | /* We do want to process the local info if the insn was | |
6dfdc153 | 3571 | deleted. For instance, if the insn did a wild read, we |
3072d30e | 3572 | no longer need to trash the info. */ |
48e1416a | 3573 | if (insn_info->insn |
3072d30e | 3574 | && INSN_P (insn_info->insn) |
3575 | && (!deleted)) | |
3576 | { | |
3577 | scan_stores_nospill (insn_info->store_rec, v, NULL); | |
3578 | if (insn_info->wild_read) | |
3579 | { | |
1ca59310 | 3580 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 3581 | fprintf (dump_file, "wild read\n"); |
3582 | bitmap_clear (v); | |
3583 | } | |
b4a708fb | 3584 | else if (insn_info->read_rec |
3585 | || insn_info->non_frame_wild_read) | |
3072d30e | 3586 | { |
b4a708fb | 3587 | if (dump_file && !insn_info->non_frame_wild_read) |
3072d30e | 3588 | fprintf (dump_file, "regular read\n"); |
1ca59310 | 3589 | else if (dump_file && (dump_flags & TDF_DETAILS)) |
b4a708fb | 3590 | fprintf (dump_file, "non-frame wild read\n"); |
3072d30e | 3591 | scan_reads_nospill (insn_info, v, NULL); |
3592 | } | |
3593 | } | |
48e1416a | 3594 | |
3072d30e | 3595 | insn_info = insn_info->prev_insn; |
3596 | } | |
3597 | } | |
3598 | } | |
3599 | ||
3600 | ||
3072d30e | 3601 | \f |
3602 | /*---------------------------------------------------------------------------- | |
3603 | Sixth step. | |
3604 | ||
aa140b76 | 3605 | Delete stores made redundant by earlier stores (which store the same |
3606 | value) that couldn't be eliminated. | |
3607 | ----------------------------------------------------------------------------*/ | |
3608 | ||
3609 | static void | |
3610 | dse_step6 (void) | |
3611 | { | |
3612 | basic_block bb; | |
3613 | ||
ed7d889a | 3614 | FOR_ALL_BB_FN (bb, cfun) |
aa140b76 | 3615 | { |
3616 | bb_info_t bb_info = bb_table[bb->index]; | |
3617 | insn_info_t insn_info = bb_info->last_insn; | |
3618 | ||
3619 | while (insn_info) | |
3620 | { | |
3621 | /* There may have been code deleted by the dce pass run before | |
3622 | this phase. */ | |
3623 | if (insn_info->insn | |
3624 | && INSN_P (insn_info->insn) | |
3625 | && !insn_info->cannot_delete) | |
3626 | { | |
3627 | store_info_t s_info = insn_info->store_rec; | |
3628 | ||
3629 | while (s_info && !s_info->is_set) | |
3630 | s_info = s_info->next; | |
3631 | if (s_info | |
3632 | && s_info->redundant_reason | |
3633 | && s_info->redundant_reason->insn | |
3634 | && INSN_P (s_info->redundant_reason->insn)) | |
3635 | { | |
cccc26f6 | 3636 | rtx_insn *rinsn = s_info->redundant_reason->insn; |
1ca59310 | 3637 | if (dump_file && (dump_flags & TDF_DETAILS)) |
aa140b76 | 3638 | fprintf (dump_file, "Locally deleting insn %d " |
3639 | "because insn %d stores the " | |
3640 | "same value and couldn't be " | |
3641 | "eliminated\n", | |
3642 | INSN_UID (insn_info->insn), | |
3643 | INSN_UID (rinsn)); | |
3644 | delete_dead_store_insn (insn_info); | |
3645 | } | |
3646 | } | |
3647 | insn_info = insn_info->prev_insn; | |
3648 | } | |
3649 | } | |
3650 | } | |
3651 | \f | |
3652 | /*---------------------------------------------------------------------------- | |
3653 | Seventh step. | |
3654 | ||
48e1416a | 3655 | Destroy everything left standing. |
3072d30e | 3656 | ----------------------------------------------------------------------------*/ |
3657 | ||
48e1416a | 3658 | static void |
4fb07d00 | 3659 | dse_step7 (void) |
3072d30e | 3660 | { |
4fb07d00 | 3661 | bitmap_obstack_release (&dse_bitmap_obstack); |
3662 | obstack_free (&dse_obstack, NULL); | |
ce299759 | 3663 | |
3072d30e | 3664 | end_alias_analysis (); |
3665 | free (bb_table); | |
c1f445d2 | 3666 | delete rtx_group_table; |
3667 | rtx_group_table = NULL; | |
f1f41a6c | 3668 | rtx_group_vec.release (); |
3072d30e | 3669 | BITMAP_FREE (all_blocks); |
3670 | BITMAP_FREE (scratch); | |
3671 | ||
55c5ac9f | 3672 | rtx_store_info_pool.release (); |
e16712b1 | 3673 | read_info_type_pool.release (); |
3674 | insn_info_type_pool.release (); | |
3675 | dse_bb_info_type_pool.release (); | |
3676 | group_info_pool.release (); | |
3677 | deferred_change_pool.release (); | |
3072d30e | 3678 | } |
3679 | ||
3680 | ||
3072d30e | 3681 | /* ------------------------------------------------------------------------- |
3682 | DSE | |
3683 | ------------------------------------------------------------------------- */ | |
3684 | ||
3685 | /* Callback for running pass_rtl_dse. */ | |
3686 | ||
3687 | static unsigned int | |
3688 | rest_of_handle_dse (void) | |
3689 | { | |
3072d30e | 3690 | df_set_flags (DF_DEFER_INSN_RESCAN); |
3691 | ||
a1b0a968 | 3692 | /* Need the notes since we must track live hardregs in the forwards |
3693 | direction. */ | |
3694 | df_note_add_problem (); | |
3695 | df_analyze (); | |
3696 | ||
3072d30e | 3697 | dse_step0 (); |
3698 | dse_step1 (); | |
3699 | dse_step2_init (); | |
3700 | if (dse_step2_nospill ()) | |
3701 | { | |
3702 | df_set_flags (DF_LR_RUN_DCE); | |
3703 | df_analyze (); | |
1ca59310 | 3704 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 3705 | fprintf (dump_file, "doing global processing\n"); |
3706 | dse_step3 (false); | |
3707 | dse_step4 (); | |
3708 | dse_step5_nospill (); | |
3709 | } | |
3710 | ||
aa140b76 | 3711 | dse_step6 (); |
4fb07d00 | 3712 | dse_step7 (); |
3072d30e | 3713 | |
3714 | if (dump_file) | |
3715 | fprintf (dump_file, "dse: local deletions = %d, global deletions = %d, spill deletions = %d\n", | |
3716 | locally_deleted, globally_deleted, spill_deleted); | |
1f91a12d | 3717 | |
3718 | /* DSE can eliminate potentially-trapping MEMs. | |
3719 | Remove any EH edges associated with them. */ | |
3720 | if ((locally_deleted || globally_deleted) | |
3721 | && cfun->can_throw_non_call_exceptions | |
3722 | && purge_all_dead_edges ()) | |
3723 | cleanup_cfg (0); | |
3724 | ||
3072d30e | 3725 | return 0; |
3726 | } | |
3727 | ||
cbe8bda8 | 3728 | namespace { |
3729 | ||
3730 | const pass_data pass_data_rtl_dse1 = | |
3731 | { | |
3732 | RTL_PASS, /* type */ | |
3733 | "dse1", /* name */ | |
3734 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3735 | TV_DSE1, /* tv_id */ |
3736 | 0, /* properties_required */ | |
3737 | 0, /* properties_provided */ | |
3738 | 0, /* properties_destroyed */ | |
3739 | 0, /* todo_flags_start */ | |
8b88439e | 3740 | TODO_df_finish, /* todo_flags_finish */ |
3072d30e | 3741 | }; |
3742 | ||
cbe8bda8 | 3743 | class pass_rtl_dse1 : public rtl_opt_pass |
3744 | { | |
3745 | public: | |
9af5ce0c | 3746 | pass_rtl_dse1 (gcc::context *ctxt) |
3747 | : rtl_opt_pass (pass_data_rtl_dse1, ctxt) | |
cbe8bda8 | 3748 | {} |
3749 | ||
3750 | /* opt_pass methods: */ | |
31315c24 | 3751 | virtual bool gate (function *) |
3752 | { | |
3753 | return optimize > 0 && flag_dse && dbg_cnt (dse1); | |
3754 | } | |
3755 | ||
65b0537f | 3756 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
cbe8bda8 | 3757 | |
3758 | }; // class pass_rtl_dse1 | |
3759 | ||
3760 | } // anon namespace | |
3761 | ||
3762 | rtl_opt_pass * | |
3763 | make_pass_rtl_dse1 (gcc::context *ctxt) | |
3764 | { | |
3765 | return new pass_rtl_dse1 (ctxt); | |
3766 | } | |
3767 | ||
3768 | namespace { | |
3769 | ||
3770 | const pass_data pass_data_rtl_dse2 = | |
3771 | { | |
3772 | RTL_PASS, /* type */ | |
3773 | "dse2", /* name */ | |
3774 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3775 | TV_DSE2, /* tv_id */ |
3776 | 0, /* properties_required */ | |
3777 | 0, /* properties_provided */ | |
3778 | 0, /* properties_destroyed */ | |
3779 | 0, /* todo_flags_start */ | |
8b88439e | 3780 | TODO_df_finish, /* todo_flags_finish */ |
3072d30e | 3781 | }; |
cbe8bda8 | 3782 | |
3783 | class pass_rtl_dse2 : public rtl_opt_pass | |
3784 | { | |
3785 | public: | |
9af5ce0c | 3786 | pass_rtl_dse2 (gcc::context *ctxt) |
3787 | : rtl_opt_pass (pass_data_rtl_dse2, ctxt) | |
cbe8bda8 | 3788 | {} |
3789 | ||
3790 | /* opt_pass methods: */ | |
31315c24 | 3791 | virtual bool gate (function *) |
3792 | { | |
3793 | return optimize > 0 && flag_dse && dbg_cnt (dse2); | |
3794 | } | |
3795 | ||
65b0537f | 3796 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
cbe8bda8 | 3797 | |
3798 | }; // class pass_rtl_dse2 | |
3799 | ||
3800 | } // anon namespace | |
3801 | ||
3802 | rtl_opt_pass * | |
3803 | make_pass_rtl_dse2 (gcc::context *ctxt) | |
3804 | { | |
3805 | return new pass_rtl_dse2 (ctxt); | |
3806 | } |