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6fb5fa3c | 1 | /* RTL dead store elimination. |
5624e564 | 2 | Copyright (C) 2005-2015 Free Software Foundation, Inc. |
6fb5fa3c DB |
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 | |
9dcd6f09 | 11 | Software Foundation; either version 3, or (at your option) any later |
6fb5fa3c DB |
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 | |
9dcd6f09 NC |
20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
6fb5fa3c DB |
22 | |
23 | #undef BASELINE | |
24 | ||
25 | #include "config.h" | |
26 | #include "system.h" | |
27 | #include "coretypes.h" | |
703c8606 | 28 | #include "hash-table.h" |
6fb5fa3c DB |
29 | #include "tm.h" |
30 | #include "rtl.h" | |
40e23961 MC |
31 | #include "hash-set.h" |
32 | #include "machmode.h" | |
33 | #include "vec.h" | |
34 | #include "double-int.h" | |
35 | #include "input.h" | |
36 | #include "alias.h" | |
37 | #include "symtab.h" | |
38 | #include "wide-int.h" | |
39 | #include "inchash.h" | |
40 | #include "real.h" | |
6fb5fa3c | 41 | #include "tree.h" |
40e23961 | 42 | #include "fold-const.h" |
d8a2d370 | 43 | #include "stor-layout.h" |
18b526e8 | 44 | #include "tm_p.h" |
6fb5fa3c DB |
45 | #include "regs.h" |
46 | #include "hard-reg-set.h" | |
9e582b1d | 47 | #include "regset.h" |
6fb5fa3c | 48 | #include "flags.h" |
60393bbc AM |
49 | #include "dominance.h" |
50 | #include "cfg.h" | |
51 | #include "cfgrtl.h" | |
52 | #include "predict.h" | |
53 | #include "basic-block.h" | |
6fb5fa3c DB |
54 | #include "df.h" |
55 | #include "cselib.h" | |
6fb5fa3c DB |
56 | #include "tree-pass.h" |
57 | #include "alloc-pool.h" | |
6fb5fa3c | 58 | #include "insn-config.h" |
36566b39 PK |
59 | #include "hashtab.h" |
60 | #include "function.h" | |
61 | #include "statistics.h" | |
62 | #include "fixed-value.h" | |
63 | #include "expmed.h" | |
64 | #include "dojump.h" | |
65 | #include "explow.h" | |
66 | #include "calls.h" | |
67 | #include "emit-rtl.h" | |
68 | #include "varasm.h" | |
69 | #include "stmt.h" | |
6fb5fa3c DB |
70 | #include "expr.h" |
71 | #include "recog.h" | |
b0710fe1 | 72 | #include "insn-codes.h" |
8660aaae | 73 | #include "optabs.h" |
6fb5fa3c | 74 | #include "dbgcnt.h" |
67d0afe9 | 75 | #include "target.h" |
dabd47e7 | 76 | #include "params.h" |
2fb9a547 AM |
77 | #include "tree-ssa-alias.h" |
78 | #include "internal-fn.h" | |
79 | #include "gimple-expr.h" | |
80 | #include "is-a.h" | |
442b4905 AM |
81 | #include "gimple.h" |
82 | #include "gimple-ssa.h" | |
d7111da8 | 83 | #include "rtl-iter.h" |
6c5ed3f1 | 84 | #include "cfgcleanup.h" |
6fb5fa3c DB |
85 | |
86 | /* This file contains three techniques for performing Dead Store | |
b8698a0f | 87 | Elimination (dse). |
6fb5fa3c DB |
88 | |
89 | * The first technique performs dse locally on any base address. It | |
90 | is based on the cselib which is a local value numbering technique. | |
91 | This technique is local to a basic block but deals with a fairly | |
92 | general addresses. | |
b8698a0f | 93 | |
6fb5fa3c DB |
94 | * The second technique performs dse globally but is restricted to |
95 | base addresses that are either constant or are relative to the | |
96 | frame_pointer. | |
97 | ||
98 | * The third technique, (which is only done after register allocation) | |
99 | processes the spill spill slots. This differs from the second | |
100 | technique because it takes advantage of the fact that spilling is | |
101 | completely free from the effects of aliasing. | |
102 | ||
103 | Logically, dse is a backwards dataflow problem. A store can be | |
104 | deleted if it if cannot be reached in the backward direction by any | |
105 | use of the value being stored. However, the local technique uses a | |
106 | forwards scan of the basic block because cselib requires that the | |
107 | block be processed in that order. | |
108 | ||
109 | The pass is logically broken into 7 steps: | |
110 | ||
111 | 0) Initialization. | |
112 | ||
113 | 1) The local algorithm, as well as scanning the insns for the two | |
114 | global algorithms. | |
115 | ||
116 | 2) Analysis to see if the global algs are necessary. In the case | |
117 | of stores base on a constant address, there must be at least two | |
118 | stores to that address, to make it possible to delete some of the | |
119 | stores. In the case of stores off of the frame or spill related | |
120 | stores, only one store to an address is necessary because those | |
121 | stores die at the end of the function. | |
122 | ||
b8698a0f | 123 | 3) Set up the global dataflow equations based on processing the |
6fb5fa3c DB |
124 | info parsed in the first step. |
125 | ||
126 | 4) Solve the dataflow equations. | |
127 | ||
128 | 5) Delete the insns that the global analysis has indicated are | |
129 | unnecessary. | |
130 | ||
073a8998 | 131 | 6) Delete insns that store the same value as preceding store |
8dd5516b JJ |
132 | where the earlier store couldn't be eliminated. |
133 | ||
134 | 7) Cleanup. | |
6fb5fa3c DB |
135 | |
136 | This step uses cselib and canon_rtx to build the largest expression | |
137 | possible for each address. This pass is a forwards pass through | |
138 | each basic block. From the point of view of the global technique, | |
139 | the first pass could examine a block in either direction. The | |
0d52bcc1 | 140 | forwards ordering is to accommodate cselib. |
6fb5fa3c | 141 | |
5ef0b50d | 142 | We make a simplifying assumption: addresses fall into four broad |
6fb5fa3c DB |
143 | categories: |
144 | ||
145 | 1) base has rtx_varies_p == false, offset is constant. | |
146 | 2) base has rtx_varies_p == false, offset variable. | |
147 | 3) base has rtx_varies_p == true, offset constant. | |
148 | 4) base has rtx_varies_p == true, offset variable. | |
149 | ||
150 | The local passes are able to process all 4 kinds of addresses. The | |
5ef0b50d | 151 | global pass only handles 1). |
6fb5fa3c DB |
152 | |
153 | The global problem is formulated as follows: | |
154 | ||
155 | A store, S1, to address A, where A is not relative to the stack | |
156 | frame, can be eliminated if all paths from S1 to the end of the | |
5ef0b50d | 157 | function contain another store to A before a read to A. |
6fb5fa3c DB |
158 | |
159 | If the address A is relative to the stack frame, a store S2 to A | |
5ef0b50d | 160 | can be eliminated if there are no paths from S2 that reach the |
6fb5fa3c | 161 | end of the function that read A before another store to A. In |
5ef0b50d | 162 | this case S2 can be deleted if there are paths from S2 to the |
6fb5fa3c DB |
163 | end of the function that have no reads or writes to A. This |
164 | second case allows stores to the stack frame to be deleted that | |
165 | would otherwise die when the function returns. This cannot be | |
166 | done if stores_off_frame_dead_at_return is not true. See the doc | |
167 | for that variable for when this variable is false. | |
168 | ||
169 | The global problem is formulated as a backwards set union | |
170 | dataflow problem where the stores are the gens and reads are the | |
171 | kills. Set union problems are rare and require some special | |
172 | handling given our representation of bitmaps. A straightforward | |
5ef0b50d | 173 | implementation requires a lot of bitmaps filled with 1s. |
6fb5fa3c DB |
174 | These are expensive and cumbersome in our bitmap formulation so |
175 | care has been taken to avoid large vectors filled with 1s. See | |
176 | the comments in bb_info and in the dataflow confluence functions | |
b8698a0f | 177 | for details. |
6fb5fa3c DB |
178 | |
179 | There are two places for further enhancements to this algorithm: | |
b8698a0f | 180 | |
6fb5fa3c DB |
181 | 1) The original dse which was embedded in a pass called flow also |
182 | did local address forwarding. For example in | |
183 | ||
184 | A <- r100 | |
185 | ... <- A | |
186 | ||
187 | flow would replace the right hand side of the second insn with a | |
6ed3da00 | 188 | reference to r100. Most of the information is available to add this |
6fb5fa3c DB |
189 | to this pass. It has not done it because it is a lot of work in |
190 | the case that either r100 is assigned to between the first and | |
191 | second insn and/or the second insn is a load of part of the value | |
192 | stored by the first insn. | |
193 | ||
194 | insn 5 in gcc.c-torture/compile/990203-1.c simple case. | |
195 | insn 15 in gcc.c-torture/execute/20001017-2.c simple case. | |
196 | insn 25 in gcc.c-torture/execute/20001026-1.c simple case. | |
197 | insn 44 in gcc.c-torture/execute/20010910-1.c simple case. | |
198 | ||
199 | 2) The cleaning up of spill code is quite profitable. It currently | |
200 | depends on reading tea leaves and chicken entrails left by reload. | |
201 | This pass depends on reload creating a singleton alias set for each | |
202 | spill slot and telling the next dse pass which of these alias sets | |
203 | are the singletons. Rather than analyze the addresses of the | |
204 | spills, dse's spill processing just does analysis of the loads and | |
205 | stores that use those alias sets. There are three cases where this | |
206 | falls short: | |
207 | ||
208 | a) Reload sometimes creates the slot for one mode of access, and | |
209 | then inserts loads and/or stores for a smaller mode. In this | |
210 | case, the current code just punts on the slot. The proper thing | |
211 | to do is to back out and use one bit vector position for each | |
212 | byte of the entity associated with the slot. This depends on | |
213 | KNOWING that reload always generates the accesses for each of the | |
214 | bytes in some canonical (read that easy to understand several | |
215 | passes after reload happens) way. | |
216 | ||
217 | b) Reload sometimes decides that spill slot it allocated was not | |
218 | large enough for the mode and goes back and allocates more slots | |
219 | with the same mode and alias set. The backout in this case is a | |
220 | little more graceful than (a). In this case the slot is unmarked | |
221 | as being a spill slot and if final address comes out to be based | |
b8698a0f | 222 | off the frame pointer, the global algorithm handles this slot. |
6fb5fa3c DB |
223 | |
224 | c) For any pass that may prespill, there is currently no | |
225 | mechanism to tell the dse pass that the slot being used has the | |
226 | special properties that reload uses. It may be that all that is | |
0d52bcc1 | 227 | required is to have those passes make the same calls that reload |
6fb5fa3c DB |
228 | does, assuming that the alias sets can be manipulated in the same |
229 | way. */ | |
230 | ||
231 | /* There are limits to the size of constant offsets we model for the | |
232 | global problem. There are certainly test cases, that exceed this | |
233 | limit, however, it is unlikely that there are important programs | |
234 | that really have constant offsets this size. */ | |
235 | #define MAX_OFFSET (64 * 1024) | |
236 | ||
3f9b14ff SB |
237 | /* Obstack for the DSE dataflow bitmaps. We don't want to put these |
238 | on the default obstack because these bitmaps can grow quite large | |
239 | (~2GB for the small (!) test case of PR54146) and we'll hold on to | |
240 | all that memory until the end of the compiler run. | |
241 | As a bonus, delete_tree_live_info can destroy all the bitmaps by just | |
242 | releasing the whole obstack. */ | |
243 | static bitmap_obstack dse_bitmap_obstack; | |
244 | ||
245 | /* Obstack for other data. As for above: Kinda nice to be able to | |
246 | throw it all away at the end in one big sweep. */ | |
247 | static struct obstack dse_obstack; | |
248 | ||
249 | /* Scratch bitmap for cselib's cselib_expand_value_rtx. */ | |
6fb5fa3c | 250 | static bitmap scratch = NULL; |
3f9b14ff | 251 | |
6fb5fa3c DB |
252 | struct insn_info; |
253 | ||
254 | /* This structure holds information about a candidate store. */ | |
b8698a0f | 255 | struct store_info |
6fb5fa3c DB |
256 | { |
257 | ||
258 | /* False means this is a clobber. */ | |
259 | bool is_set; | |
260 | ||
8dd5516b JJ |
261 | /* False if a single HOST_WIDE_INT bitmap is used for positions_needed. */ |
262 | bool is_large; | |
263 | ||
6fb5fa3c DB |
264 | /* The id of the mem group of the base address. If rtx_varies_p is |
265 | true, this is -1. Otherwise, it is the index into the group | |
266 | table. */ | |
267 | int group_id; | |
b8698a0f | 268 | |
6fb5fa3c DB |
269 | /* This is the cselib value. */ |
270 | cselib_val *cse_base; | |
271 | ||
272 | /* This canonized mem. */ | |
273 | rtx mem; | |
274 | ||
6216f94e | 275 | /* Canonized MEM address for use by canon_true_dependence. */ |
6fb5fa3c DB |
276 | rtx mem_addr; |
277 | ||
278 | /* If this is non-zero, it is the alias set of a spill location. */ | |
4862826d | 279 | alias_set_type alias_set; |
6fb5fa3c DB |
280 | |
281 | /* The offset of the first and byte before the last byte associated | |
282 | with the operation. */ | |
8dd5516b JJ |
283 | HOST_WIDE_INT begin, end; |
284 | ||
285 | union | |
286 | { | |
287 | /* A bitmask as wide as the number of bytes in the word that | |
288 | contains a 1 if the byte may be needed. The store is unused if | |
289 | all of the bits are 0. This is used if IS_LARGE is false. */ | |
290 | unsigned HOST_WIDE_INT small_bitmask; | |
291 | ||
292 | struct | |
293 | { | |
294 | /* A bitmap with one bit per byte. Cleared bit means the position | |
295 | is needed. Used if IS_LARGE is false. */ | |
dc491a25 | 296 | bitmap bmap; |
6fb5fa3c | 297 | |
8dd5516b JJ |
298 | /* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is |
299 | equal to END - BEGIN, the whole store is unused. */ | |
300 | int count; | |
301 | } large; | |
302 | } positions_needed; | |
6fb5fa3c DB |
303 | |
304 | /* The next store info for this insn. */ | |
305 | struct store_info *next; | |
306 | ||
307 | /* The right hand side of the store. This is used if there is a | |
308 | subsequent reload of the mems address somewhere later in the | |
309 | basic block. */ | |
8dd5516b JJ |
310 | rtx rhs; |
311 | ||
312 | /* If rhs is or holds a constant, this contains that constant, | |
313 | otherwise NULL. */ | |
314 | rtx const_rhs; | |
315 | ||
316 | /* Set if this store stores the same constant value as REDUNDANT_REASON | |
317 | insn stored. These aren't eliminated early, because doing that | |
318 | might prevent the earlier larger store to be eliminated. */ | |
319 | struct insn_info *redundant_reason; | |
6fb5fa3c DB |
320 | }; |
321 | ||
4fe663b0 L |
322 | /* Return a bitmask with the first N low bits set. */ |
323 | ||
324 | static unsigned HOST_WIDE_INT | |
325 | lowpart_bitmask (int n) | |
326 | { | |
327 | unsigned HOST_WIDE_INT mask = ~(unsigned HOST_WIDE_INT) 0; | |
328 | return mask >> (HOST_BITS_PER_WIDE_INT - n); | |
329 | } | |
330 | ||
6fb5fa3c DB |
331 | typedef struct store_info *store_info_t; |
332 | static alloc_pool cse_store_info_pool; | |
333 | static alloc_pool rtx_store_info_pool; | |
334 | ||
335 | /* This structure holds information about a load. These are only | |
336 | built for rtx bases. */ | |
b8698a0f | 337 | struct read_info |
6fb5fa3c DB |
338 | { |
339 | /* The id of the mem group of the base address. */ | |
340 | int group_id; | |
341 | ||
342 | /* If this is non-zero, it is the alias set of a spill location. */ | |
4862826d | 343 | alias_set_type alias_set; |
6fb5fa3c DB |
344 | |
345 | /* The offset of the first and byte after the last byte associated | |
346 | with the operation. If begin == end == 0, the read did not have | |
347 | a constant offset. */ | |
348 | int begin, end; | |
349 | ||
350 | /* The mem being read. */ | |
351 | rtx mem; | |
352 | ||
353 | /* The next read_info for this insn. */ | |
354 | struct read_info *next; | |
355 | }; | |
356 | typedef struct read_info *read_info_t; | |
357 | static alloc_pool read_info_pool; | |
358 | ||
359 | ||
360 | /* One of these records is created for each insn. */ | |
361 | ||
b8698a0f | 362 | struct insn_info |
6fb5fa3c DB |
363 | { |
364 | /* Set true if the insn contains a store but the insn itself cannot | |
365 | be deleted. This is set if the insn is a parallel and there is | |
366 | more than one non dead output or if the insn is in some way | |
367 | volatile. */ | |
368 | bool cannot_delete; | |
369 | ||
370 | /* This field is only used by the global algorithm. It is set true | |
371 | if the insn contains any read of mem except for a (1). This is | |
372 | also set if the insn is a call or has a clobber mem. If the insn | |
373 | contains a wild read, the use_rec will be null. */ | |
374 | bool wild_read; | |
375 | ||
d26c7090 ER |
376 | /* This is true only for CALL instructions which could potentially read |
377 | any non-frame memory location. This field is used by the global | |
378 | algorithm. */ | |
379 | bool non_frame_wild_read; | |
380 | ||
50f0f366 EB |
381 | /* This field is only used for the processing of const functions. |
382 | These functions cannot read memory, but they can read the stack | |
64520bdc EB |
383 | because that is where they may get their parms. We need to be |
384 | this conservative because, like the store motion pass, we don't | |
385 | consider CALL_INSN_FUNCTION_USAGE when processing call insns. | |
386 | Moreover, we need to distinguish two cases: | |
387 | 1. Before reload (register elimination), the stores related to | |
388 | outgoing arguments are stack pointer based and thus deemed | |
389 | of non-constant base in this pass. This requires special | |
390 | handling but also means that the frame pointer based stores | |
391 | need not be killed upon encountering a const function call. | |
392 | 2. After reload, the stores related to outgoing arguments can be | |
393 | either stack pointer or hard frame pointer based. This means | |
394 | that we have no other choice than also killing all the frame | |
395 | pointer based stores upon encountering a const function call. | |
57534689 JJ |
396 | This field is set after reload for const function calls and before |
397 | reload for const tail function calls on targets where arg pointer | |
398 | is the frame pointer. Having this set is less severe than a wild | |
399 | read, it just means that all the frame related stores are killed | |
400 | rather than all the stores. */ | |
64520bdc EB |
401 | bool frame_read; |
402 | ||
403 | /* This field is only used for the processing of const functions. | |
404 | It is set if the insn may contain a stack pointer based store. */ | |
50f0f366 | 405 | bool stack_pointer_based; |
6fb5fa3c DB |
406 | |
407 | /* This is true if any of the sets within the store contains a | |
408 | cselib base. Such stores can only be deleted by the local | |
409 | algorithm. */ | |
410 | bool contains_cselib_groups; | |
411 | ||
412 | /* The insn. */ | |
dd60a84c | 413 | rtx_insn *insn; |
6fb5fa3c DB |
414 | |
415 | /* The list of mem sets or mem clobbers that are contained in this | |
416 | insn. If the insn is deletable, it contains only one mem set. | |
417 | But it could also contain clobbers. Insns that contain more than | |
418 | one mem set are not deletable, but each of those mems are here in | |
6ed3da00 | 419 | order to provide info to delete other insns. */ |
6fb5fa3c DB |
420 | store_info_t store_rec; |
421 | ||
422 | /* The linked list of mem uses in this insn. Only the reads from | |
423 | rtx bases are listed here. The reads to cselib bases are | |
424 | completely processed during the first scan and so are never | |
425 | created. */ | |
426 | read_info_t read_rec; | |
427 | ||
9e582b1d JR |
428 | /* The live fixed registers. We assume only fixed registers can |
429 | cause trouble by being clobbered from an expanded pattern; | |
430 | storing only the live fixed registers (rather than all registers) | |
431 | means less memory needs to be allocated / copied for the individual | |
432 | stores. */ | |
433 | regset fixed_regs_live; | |
434 | ||
6fb5fa3c DB |
435 | /* The prev insn in the basic block. */ |
436 | struct insn_info * prev_insn; | |
437 | ||
438 | /* The linked list of insns that are in consideration for removal in | |
073a8998 | 439 | the forwards pass through the basic block. This pointer may be |
6fb5fa3c | 440 | trash as it is not cleared when a wild read occurs. The only |
fa10beec | 441 | time it is guaranteed to be correct is when the traversal starts |
6fb5fa3c DB |
442 | at active_local_stores. */ |
443 | struct insn_info * next_local_store; | |
444 | }; | |
445 | ||
446 | typedef struct insn_info *insn_info_t; | |
447 | static alloc_pool insn_info_pool; | |
448 | ||
449 | /* The linked list of stores that are under consideration in this | |
b8698a0f | 450 | basic block. */ |
6fb5fa3c | 451 | static insn_info_t active_local_stores; |
dabd47e7 | 452 | static int active_local_stores_len; |
6fb5fa3c | 453 | |
11478306 | 454 | struct dse_bb_info |
6fb5fa3c DB |
455 | { |
456 | ||
457 | /* Pointer to the insn info for the last insn in the block. These | |
458 | are linked so this is how all of the insns are reached. During | |
459 | scanning this is the current insn being scanned. */ | |
460 | insn_info_t last_insn; | |
461 | ||
462 | /* The info for the global dataflow problem. */ | |
463 | ||
464 | ||
465 | /* This is set if the transfer function should and in the wild_read | |
466 | bitmap before applying the kill and gen sets. That vector knocks | |
467 | out most of the bits in the bitmap and thus speeds up the | |
468 | operations. */ | |
469 | bool apply_wild_read; | |
470 | ||
02b47899 KZ |
471 | /* The following 4 bitvectors hold information about which positions |
472 | of which stores are live or dead. They are indexed by | |
473 | get_bitmap_index. */ | |
474 | ||
6fb5fa3c DB |
475 | /* The set of store positions that exist in this block before a wild read. */ |
476 | bitmap gen; | |
b8698a0f | 477 | |
6fb5fa3c DB |
478 | /* The set of load positions that exist in this block above the |
479 | same position of a store. */ | |
480 | bitmap kill; | |
481 | ||
482 | /* The set of stores that reach the top of the block without being | |
483 | killed by a read. | |
484 | ||
485 | Do not represent the in if it is all ones. Note that this is | |
486 | what the bitvector should logically be initialized to for a set | |
487 | intersection problem. However, like the kill set, this is too | |
488 | expensive. So initially, the in set will only be created for the | |
489 | exit block and any block that contains a wild read. */ | |
490 | bitmap in; | |
491 | ||
492 | /* The set of stores that reach the bottom of the block from it's | |
493 | successors. | |
494 | ||
495 | Do not represent the in if it is all ones. Note that this is | |
496 | what the bitvector should logically be initialized to for a set | |
497 | intersection problem. However, like the kill and in set, this is | |
498 | too expensive. So what is done is that the confluence operator | |
499 | just initializes the vector from one of the out sets of the | |
500 | successors of the block. */ | |
501 | bitmap out; | |
02b47899 KZ |
502 | |
503 | /* The following bitvector is indexed by the reg number. It | |
504 | contains the set of regs that are live at the current instruction | |
505 | being processed. While it contains info for all of the | |
9e582b1d JR |
506 | registers, only the hard registers are actually examined. It is used |
507 | to assure that shift and/or add sequences that are inserted do not | |
073a8998 | 508 | accidentally clobber live hard regs. */ |
02b47899 | 509 | bitmap regs_live; |
6fb5fa3c DB |
510 | }; |
511 | ||
11478306 | 512 | typedef struct dse_bb_info *bb_info_t; |
6fb5fa3c DB |
513 | static alloc_pool bb_info_pool; |
514 | ||
515 | /* Table to hold all bb_infos. */ | |
516 | static bb_info_t *bb_table; | |
517 | ||
518 | /* There is a group_info for each rtx base that is used to reference | |
519 | memory. There are also not many of the rtx bases because they are | |
520 | very limited in scope. */ | |
521 | ||
b8698a0f | 522 | struct group_info |
6fb5fa3c DB |
523 | { |
524 | /* The actual base of the address. */ | |
525 | rtx rtx_base; | |
526 | ||
527 | /* The sequential id of the base. This allows us to have a | |
528 | canonical ordering of these that is not based on addresses. */ | |
529 | int id; | |
530 | ||
8f5929e1 JJ |
531 | /* True if there are any positions that are to be processed |
532 | globally. */ | |
533 | bool process_globally; | |
534 | ||
535 | /* True if the base of this group is either the frame_pointer or | |
536 | hard_frame_pointer. */ | |
537 | bool frame_related; | |
538 | ||
d32f725a OH |
539 | /* A mem wrapped around the base pointer for the group in order to do |
540 | read dependency. It must be given BLKmode in order to encompass all | |
541 | the possible offsets from the base. */ | |
6fb5fa3c | 542 | rtx base_mem; |
b8698a0f | 543 | |
6216f94e JJ |
544 | /* Canonized version of base_mem's address. */ |
545 | rtx canon_base_addr; | |
6fb5fa3c DB |
546 | |
547 | /* These two sets of two bitmaps are used to keep track of how many | |
6ed3da00 | 548 | stores are actually referencing that position from this base. We |
6fb5fa3c | 549 | only do this for rtx bases as this will be used to assign |
6ed3da00 | 550 | positions in the bitmaps for the global problem. Bit N is set in |
6fb5fa3c DB |
551 | store1 on the first store for offset N. Bit N is set in store2 |
552 | for the second store to offset N. This is all we need since we | |
553 | only care about offsets that have two or more stores for them. | |
554 | ||
555 | The "_n" suffix is for offsets less than 0 and the "_p" suffix is | |
556 | for 0 and greater offsets. | |
557 | ||
558 | There is one special case here, for stores into the stack frame, | |
559 | we will or store1 into store2 before deciding which stores look | |
560 | at globally. This is because stores to the stack frame that have | |
561 | no other reads before the end of the function can also be | |
562 | deleted. */ | |
563 | bitmap store1_n, store1_p, store2_n, store2_p; | |
564 | ||
d26c7090 ER |
565 | /* These bitmaps keep track of offsets in this group escape this function. |
566 | An offset escapes if it corresponds to a named variable whose | |
567 | addressable flag is set. */ | |
568 | bitmap escaped_n, escaped_p; | |
569 | ||
6ed3da00 | 570 | /* The positions in this bitmap have the same assignments as the in, |
6fb5fa3c | 571 | out, gen and kill bitmaps. This bitmap is all zeros except for |
6ed3da00 | 572 | the positions that are occupied by stores for this group. */ |
6fb5fa3c DB |
573 | bitmap group_kill; |
574 | ||
6fb5fa3c | 575 | /* The offset_map is used to map the offsets from this base into |
6ed3da00 | 576 | positions in the global bitmaps. It is only created after all of |
6fb5fa3c DB |
577 | the all of stores have been scanned and we know which ones we |
578 | care about. */ | |
b8698a0f L |
579 | int *offset_map_n, *offset_map_p; |
580 | int offset_map_size_n, offset_map_size_p; | |
6fb5fa3c DB |
581 | }; |
582 | typedef struct group_info *group_info_t; | |
5f754896 | 583 | typedef const struct group_info *const_group_info_t; |
6fb5fa3c DB |
584 | static alloc_pool rtx_group_info_pool; |
585 | ||
6fb5fa3c DB |
586 | /* Index into the rtx_group_vec. */ |
587 | static int rtx_group_next_id; | |
588 | ||
6fb5fa3c | 589 | |
9771b263 | 590 | static vec<group_info_t> rtx_group_vec; |
6fb5fa3c DB |
591 | |
592 | ||
593 | /* This structure holds the set of changes that are being deferred | |
594 | when removing read operation. See replace_read. */ | |
b8698a0f | 595 | struct deferred_change |
6fb5fa3c DB |
596 | { |
597 | ||
598 | /* The mem that is being replaced. */ | |
599 | rtx *loc; | |
600 | ||
601 | /* The reg it is being replaced with. */ | |
602 | rtx reg; | |
603 | ||
604 | struct deferred_change *next; | |
605 | }; | |
606 | ||
607 | typedef struct deferred_change *deferred_change_t; | |
608 | static alloc_pool deferred_change_pool; | |
609 | ||
610 | static deferred_change_t deferred_change_list = NULL; | |
611 | ||
6fb5fa3c DB |
612 | /* The group that holds all of the clear_alias_sets. */ |
613 | static group_info_t clear_alias_group; | |
614 | ||
615 | /* The modes of the clear_alias_sets. */ | |
616 | static htab_t clear_alias_mode_table; | |
617 | ||
618 | /* Hash table element to look up the mode for an alias set. */ | |
619 | struct clear_alias_mode_holder | |
620 | { | |
4862826d | 621 | alias_set_type alias_set; |
ef4bddc2 | 622 | machine_mode mode; |
6fb5fa3c DB |
623 | }; |
624 | ||
e3b5732b | 625 | /* This is true except if cfun->stdarg -- i.e. we cannot do |
9dd9bf80 | 626 | this for vararg functions because they play games with the frame. */ |
6fb5fa3c DB |
627 | static bool stores_off_frame_dead_at_return; |
628 | ||
629 | /* Counter for stats. */ | |
b8698a0f L |
630 | static int globally_deleted; |
631 | static int locally_deleted; | |
632 | static int spill_deleted; | |
633 | ||
6fb5fa3c DB |
634 | static bitmap all_blocks; |
635 | ||
d26c7090 ER |
636 | /* Locations that are killed by calls in the global phase. */ |
637 | static bitmap kill_on_calls; | |
638 | ||
6fb5fa3c DB |
639 | /* The number of bits used in the global bitmaps. */ |
640 | static unsigned int current_position; | |
6fb5fa3c DB |
641 | \f |
642 | /*---------------------------------------------------------------------------- | |
643 | Zeroth step. | |
644 | ||
b8698a0f | 645 | Initialization. |
6fb5fa3c DB |
646 | ----------------------------------------------------------------------------*/ |
647 | ||
6fb5fa3c DB |
648 | |
649 | /* Find the entry associated with ALIAS_SET. */ | |
650 | ||
651 | static struct clear_alias_mode_holder * | |
4862826d | 652 | clear_alias_set_lookup (alias_set_type alias_set) |
6fb5fa3c DB |
653 | { |
654 | struct clear_alias_mode_holder tmp_holder; | |
655 | void **slot; | |
b8698a0f | 656 | |
6fb5fa3c DB |
657 | tmp_holder.alias_set = alias_set; |
658 | slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, NO_INSERT); | |
659 | gcc_assert (*slot); | |
b8698a0f | 660 | |
f883e0a7 | 661 | return (struct clear_alias_mode_holder *) *slot; |
6fb5fa3c DB |
662 | } |
663 | ||
664 | ||
665 | /* Hashtable callbacks for maintaining the "bases" field of | |
666 | store_group_info, given that the addresses are function invariants. */ | |
667 | ||
703c8606 LC |
668 | struct invariant_group_base_hasher : typed_noop_remove <group_info> |
669 | { | |
67f58944 TS |
670 | typedef group_info *value_type; |
671 | typedef group_info *compare_type; | |
672 | static inline hashval_t hash (const group_info *); | |
673 | static inline bool equal (const group_info *, const group_info *); | |
703c8606 LC |
674 | }; |
675 | ||
676 | inline bool | |
67f58944 TS |
677 | invariant_group_base_hasher::equal (const group_info *gi1, |
678 | const group_info *gi2) | |
6fb5fa3c | 679 | { |
6fb5fa3c DB |
680 | return rtx_equal_p (gi1->rtx_base, gi2->rtx_base); |
681 | } | |
682 | ||
703c8606 | 683 | inline hashval_t |
67f58944 | 684 | invariant_group_base_hasher::hash (const group_info *gi) |
6fb5fa3c | 685 | { |
6fb5fa3c DB |
686 | int do_not_record; |
687 | return hash_rtx (gi->rtx_base, Pmode, &do_not_record, NULL, false); | |
688 | } | |
689 | ||
703c8606 | 690 | /* Tables of group_info structures, hashed by base value. */ |
c203e8a7 | 691 | static hash_table<invariant_group_base_hasher> *rtx_group_table; |
703c8606 | 692 | |
6fb5fa3c DB |
693 | |
694 | /* Get the GROUP for BASE. Add a new group if it is not there. */ | |
695 | ||
696 | static group_info_t | |
697 | get_group_info (rtx base) | |
698 | { | |
b8698a0f L |
699 | struct group_info tmp_gi; |
700 | group_info_t gi; | |
703c8606 | 701 | group_info **slot; |
6fb5fa3c DB |
702 | |
703 | if (base) | |
704 | { | |
705 | /* Find the store_base_info structure for BASE, creating a new one | |
706 | if necessary. */ | |
707 | tmp_gi.rtx_base = base; | |
c203e8a7 | 708 | slot = rtx_group_table->find_slot (&tmp_gi, INSERT); |
6fb5fa3c DB |
709 | gi = (group_info_t) *slot; |
710 | } | |
711 | else | |
712 | { | |
713 | if (!clear_alias_group) | |
714 | { | |
f883e0a7 KG |
715 | clear_alias_group = gi = |
716 | (group_info_t) pool_alloc (rtx_group_info_pool); | |
6fb5fa3c DB |
717 | memset (gi, 0, sizeof (struct group_info)); |
718 | gi->id = rtx_group_next_id++; | |
3f9b14ff SB |
719 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
720 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
721 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
722 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
723 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
724 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
725 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c DB |
726 | gi->process_globally = false; |
727 | gi->offset_map_size_n = 0; | |
728 | gi->offset_map_size_p = 0; | |
729 | gi->offset_map_n = NULL; | |
730 | gi->offset_map_p = NULL; | |
9771b263 | 731 | rtx_group_vec.safe_push (gi); |
6fb5fa3c DB |
732 | } |
733 | return clear_alias_group; | |
734 | } | |
735 | ||
736 | if (gi == NULL) | |
737 | { | |
f883e0a7 | 738 | *slot = gi = (group_info_t) pool_alloc (rtx_group_info_pool); |
6fb5fa3c DB |
739 | gi->rtx_base = base; |
740 | gi->id = rtx_group_next_id++; | |
d32f725a | 741 | gi->base_mem = gen_rtx_MEM (BLKmode, base); |
6216f94e | 742 | gi->canon_base_addr = canon_rtx (base); |
3f9b14ff SB |
743 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
744 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
745 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
746 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
747 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
748 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
749 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c | 750 | gi->process_globally = false; |
b8698a0f | 751 | gi->frame_related = |
6fb5fa3c DB |
752 | (base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx); |
753 | gi->offset_map_size_n = 0; | |
754 | gi->offset_map_size_p = 0; | |
755 | gi->offset_map_n = NULL; | |
756 | gi->offset_map_p = NULL; | |
9771b263 | 757 | rtx_group_vec.safe_push (gi); |
6fb5fa3c DB |
758 | } |
759 | ||
760 | return gi; | |
761 | } | |
762 | ||
763 | ||
764 | /* Initialization of data structures. */ | |
765 | ||
766 | static void | |
767 | dse_step0 (void) | |
768 | { | |
769 | locally_deleted = 0; | |
770 | globally_deleted = 0; | |
771 | spill_deleted = 0; | |
772 | ||
3f9b14ff SB |
773 | bitmap_obstack_initialize (&dse_bitmap_obstack); |
774 | gcc_obstack_init (&dse_obstack); | |
775 | ||
776 | scratch = BITMAP_ALLOC (®_obstack); | |
777 | kill_on_calls = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c DB |
778 | |
779 | rtx_store_info_pool | |
b8698a0f | 780 | = create_alloc_pool ("rtx_store_info_pool", |
6fb5fa3c DB |
781 | sizeof (struct store_info), 100); |
782 | read_info_pool | |
b8698a0f | 783 | = create_alloc_pool ("read_info_pool", |
6fb5fa3c DB |
784 | sizeof (struct read_info), 100); |
785 | insn_info_pool | |
b8698a0f | 786 | = create_alloc_pool ("insn_info_pool", |
6fb5fa3c DB |
787 | sizeof (struct insn_info), 100); |
788 | bb_info_pool | |
b8698a0f | 789 | = create_alloc_pool ("bb_info_pool", |
11478306 | 790 | sizeof (struct dse_bb_info), 100); |
6fb5fa3c | 791 | rtx_group_info_pool |
b8698a0f | 792 | = create_alloc_pool ("rtx_group_info_pool", |
6fb5fa3c DB |
793 | sizeof (struct group_info), 100); |
794 | deferred_change_pool | |
b8698a0f | 795 | = create_alloc_pool ("deferred_change_pool", |
6fb5fa3c DB |
796 | sizeof (struct deferred_change), 10); |
797 | ||
c203e8a7 | 798 | rtx_group_table = new hash_table<invariant_group_base_hasher> (11); |
6fb5fa3c | 799 | |
8b1c6fd7 | 800 | bb_table = XNEWVEC (bb_info_t, last_basic_block_for_fn (cfun)); |
6fb5fa3c DB |
801 | rtx_group_next_id = 0; |
802 | ||
e3b5732b | 803 | stores_off_frame_dead_at_return = !cfun->stdarg; |
6fb5fa3c DB |
804 | |
805 | init_alias_analysis (); | |
b8698a0f | 806 | |
4b943a49 | 807 | clear_alias_group = NULL; |
6fb5fa3c DB |
808 | } |
809 | ||
810 | ||
811 | \f | |
812 | /*---------------------------------------------------------------------------- | |
813 | First step. | |
814 | ||
815 | Scan all of the insns. Any random ordering of the blocks is fine. | |
0d52bcc1 | 816 | Each block is scanned in forward order to accommodate cselib which |
6fb5fa3c DB |
817 | is used to remove stores with non-constant bases. |
818 | ----------------------------------------------------------------------------*/ | |
819 | ||
820 | /* Delete all of the store_info recs from INSN_INFO. */ | |
821 | ||
b8698a0f | 822 | static void |
6fb5fa3c DB |
823 | free_store_info (insn_info_t insn_info) |
824 | { | |
825 | store_info_t store_info = insn_info->store_rec; | |
826 | while (store_info) | |
827 | { | |
828 | store_info_t next = store_info->next; | |
8dd5516b | 829 | if (store_info->is_large) |
dc491a25 | 830 | BITMAP_FREE (store_info->positions_needed.large.bmap); |
6fb5fa3c DB |
831 | if (store_info->cse_base) |
832 | pool_free (cse_store_info_pool, store_info); | |
833 | else | |
834 | pool_free (rtx_store_info_pool, store_info); | |
835 | store_info = next; | |
836 | } | |
837 | ||
838 | insn_info->cannot_delete = true; | |
839 | insn_info->contains_cselib_groups = false; | |
840 | insn_info->store_rec = NULL; | |
841 | } | |
842 | ||
9e582b1d JR |
843 | typedef struct |
844 | { | |
dc01c3d1 | 845 | rtx_insn *first, *current; |
9e582b1d JR |
846 | regset fixed_regs_live; |
847 | bool failure; | |
848 | } note_add_store_info; | |
849 | ||
850 | /* Callback for emit_inc_dec_insn_before via note_stores. | |
851 | Check if a register is clobbered which is live afterwards. */ | |
852 | ||
853 | static void | |
854 | note_add_store (rtx loc, const_rtx expr ATTRIBUTE_UNUSED, void *data) | |
855 | { | |
dc01c3d1 | 856 | rtx_insn *insn; |
9e582b1d JR |
857 | note_add_store_info *info = (note_add_store_info *) data; |
858 | int r, n; | |
859 | ||
860 | if (!REG_P (loc)) | |
861 | return; | |
862 | ||
863 | /* If this register is referenced by the current or an earlier insn, | |
864 | that's OK. E.g. this applies to the register that is being incremented | |
865 | with this addition. */ | |
866 | for (insn = info->first; | |
867 | insn != NEXT_INSN (info->current); | |
868 | insn = NEXT_INSN (insn)) | |
869 | if (reg_referenced_p (loc, PATTERN (insn))) | |
870 | return; | |
871 | ||
872 | /* If we come here, we have a clobber of a register that's only OK | |
873 | if that register is not live. If we don't have liveness information | |
874 | available, fail now. */ | |
875 | if (!info->fixed_regs_live) | |
876 | { | |
877 | info->failure = true; | |
878 | return; | |
879 | } | |
880 | /* Now check if this is a live fixed register. */ | |
881 | r = REGNO (loc); | |
882 | n = hard_regno_nregs[r][GET_MODE (loc)]; | |
883 | while (--n >= 0) | |
884 | if (REGNO_REG_SET_P (info->fixed_regs_live, r+n)) | |
885 | info->failure = true; | |
886 | } | |
887 | ||
4deef538 AO |
888 | /* Callback for for_each_inc_dec that emits an INSN that sets DEST to |
889 | SRC + SRCOFF before insn ARG. */ | |
6fb5fa3c DB |
890 | |
891 | static int | |
4deef538 AO |
892 | emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED, |
893 | rtx op ATTRIBUTE_UNUSED, | |
894 | rtx dest, rtx src, rtx srcoff, void *arg) | |
6fb5fa3c | 895 | { |
9e582b1d | 896 | insn_info_t insn_info = (insn_info_t) arg; |
dc01c3d1 | 897 | rtx_insn *insn = insn_info->insn, *new_insn, *cur; |
9e582b1d | 898 | note_add_store_info info; |
b8698a0f | 899 | |
4deef538 AO |
900 | /* We can reuse all operands without copying, because we are about |
901 | to delete the insn that contained it. */ | |
9e582b1d | 902 | if (srcoff) |
ed079c4b JJ |
903 | { |
904 | start_sequence (); | |
905 | emit_insn (gen_add3_insn (dest, src, srcoff)); | |
906 | new_insn = get_insns (); | |
907 | end_sequence (); | |
908 | } | |
9e582b1d | 909 | else |
dc01c3d1 | 910 | new_insn = as_a <rtx_insn *> (gen_move_insn (dest, src)); |
9e582b1d JR |
911 | info.first = new_insn; |
912 | info.fixed_regs_live = insn_info->fixed_regs_live; | |
913 | info.failure = false; | |
914 | for (cur = new_insn; cur; cur = NEXT_INSN (cur)) | |
915 | { | |
916 | info.current = cur; | |
917 | note_stores (PATTERN (cur), note_add_store, &info); | |
918 | } | |
6fb5fa3c | 919 | |
9e582b1d JR |
920 | /* If a failure was flagged above, return 1 so that for_each_inc_dec will |
921 | return it immediately, communicating the failure to its caller. */ | |
922 | if (info.failure) | |
923 | return 1; | |
924 | ||
925 | emit_insn_before (new_insn, insn); | |
6fb5fa3c | 926 | |
8d8e205b | 927 | return 0; |
6fb5fa3c DB |
928 | } |
929 | ||
9e582b1d JR |
930 | /* Before we delete INSN_INFO->INSN, make sure that the auto inc/dec, if it |
931 | is there, is split into a separate insn. | |
932 | Return true on success (or if there was nothing to do), false on failure. */ | |
6fb5fa3c | 933 | |
9e582b1d JR |
934 | static bool |
935 | check_for_inc_dec_1 (insn_info_t insn_info) | |
6fb5fa3c | 936 | { |
dd60a84c | 937 | rtx_insn *insn = insn_info->insn; |
6fb5fa3c DB |
938 | rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
939 | if (note) | |
8d8e205b RS |
940 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
941 | insn_info) == 0; | |
9e582b1d | 942 | return true; |
6fb5fa3c DB |
943 | } |
944 | ||
945 | ||
9e582b1d JR |
946 | /* Entry point for postreload. If you work on reload_cse, or you need this |
947 | anywhere else, consider if you can provide register liveness information | |
948 | and add a parameter to this function so that it can be passed down in | |
949 | insn_info.fixed_regs_live. */ | |
950 | bool | |
dd60a84c | 951 | check_for_inc_dec (rtx_insn *insn) |
9e582b1d JR |
952 | { |
953 | struct insn_info insn_info; | |
954 | rtx note; | |
955 | ||
956 | insn_info.insn = insn; | |
957 | insn_info.fixed_regs_live = NULL; | |
958 | note = find_reg_note (insn, REG_INC, NULL_RTX); | |
959 | if (note) | |
8d8e205b RS |
960 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
961 | &insn_info) == 0; | |
9e582b1d JR |
962 | return true; |
963 | } | |
964 | ||
b8698a0f | 965 | /* Delete the insn and free all of the fields inside INSN_INFO. */ |
6fb5fa3c DB |
966 | |
967 | static void | |
968 | delete_dead_store_insn (insn_info_t insn_info) | |
969 | { | |
970 | read_info_t read_info; | |
971 | ||
972 | if (!dbg_cnt (dse)) | |
973 | return; | |
974 | ||
9e582b1d JR |
975 | if (!check_for_inc_dec_1 (insn_info)) |
976 | return; | |
456610d3 | 977 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 978 | { |
b8698a0f | 979 | fprintf (dump_file, "Locally deleting insn %d ", |
6fb5fa3c DB |
980 | INSN_UID (insn_info->insn)); |
981 | if (insn_info->store_rec->alias_set) | |
b8698a0f | 982 | fprintf (dump_file, "alias set %d\n", |
4862826d | 983 | (int) insn_info->store_rec->alias_set); |
6fb5fa3c DB |
984 | else |
985 | fprintf (dump_file, "\n"); | |
986 | } | |
987 | ||
988 | free_store_info (insn_info); | |
989 | read_info = insn_info->read_rec; | |
b8698a0f | 990 | |
6fb5fa3c DB |
991 | while (read_info) |
992 | { | |
993 | read_info_t next = read_info->next; | |
994 | pool_free (read_info_pool, read_info); | |
995 | read_info = next; | |
996 | } | |
997 | insn_info->read_rec = NULL; | |
998 | ||
999 | delete_insn (insn_info->insn); | |
1000 | locally_deleted++; | |
1001 | insn_info->insn = NULL; | |
1002 | ||
1003 | insn_info->wild_read = false; | |
1004 | } | |
1005 | ||
88d8330d EB |
1006 | /* Return whether DECL, a local variable, can possibly escape the current |
1007 | function scope. */ | |
1008 | ||
1009 | static bool | |
1010 | local_variable_can_escape (tree decl) | |
1011 | { | |
1012 | if (TREE_ADDRESSABLE (decl)) | |
1013 | return true; | |
1014 | ||
1015 | /* If this is a partitioned variable, we need to consider all the variables | |
1016 | in the partition. This is necessary because a store into one of them can | |
1017 | be replaced with a store into another and this may not change the outcome | |
1018 | of the escape analysis. */ | |
1019 | if (cfun->gimple_df->decls_to_pointers != NULL) | |
1020 | { | |
39c8aaa4 | 1021 | tree *namep = cfun->gimple_df->decls_to_pointers->get (decl); |
88d8330d | 1022 | if (namep) |
39c8aaa4 | 1023 | return TREE_ADDRESSABLE (*namep); |
88d8330d EB |
1024 | } |
1025 | ||
1026 | return false; | |
1027 | } | |
1028 | ||
1029 | /* Return whether EXPR can possibly escape the current function scope. */ | |
1030 | ||
d26c7090 ER |
1031 | static bool |
1032 | can_escape (tree expr) | |
1033 | { | |
1034 | tree base; | |
1035 | if (!expr) | |
1036 | return true; | |
1037 | base = get_base_address (expr); | |
1038 | if (DECL_P (base) | |
88d8330d EB |
1039 | && !may_be_aliased (base) |
1040 | && !(TREE_CODE (base) == VAR_DECL | |
1041 | && !DECL_EXTERNAL (base) | |
1042 | && !TREE_STATIC (base) | |
1043 | && local_variable_can_escape (base))) | |
d26c7090 ER |
1044 | return false; |
1045 | return true; | |
1046 | } | |
6fb5fa3c DB |
1047 | |
1048 | /* Set the store* bitmaps offset_map_size* fields in GROUP based on | |
1049 | OFFSET and WIDTH. */ | |
1050 | ||
1051 | static void | |
d26c7090 ER |
1052 | set_usage_bits (group_info_t group, HOST_WIDE_INT offset, HOST_WIDE_INT width, |
1053 | tree expr) | |
6fb5fa3c DB |
1054 | { |
1055 | HOST_WIDE_INT i; | |
d26c7090 | 1056 | bool expr_escapes = can_escape (expr); |
8dd5516b | 1057 | if (offset > -MAX_OFFSET && offset + width < MAX_OFFSET) |
6fb5fa3c DB |
1058 | for (i=offset; i<offset+width; i++) |
1059 | { | |
1060 | bitmap store1; | |
1061 | bitmap store2; | |
d26c7090 | 1062 | bitmap escaped; |
6fb5fa3c DB |
1063 | int ai; |
1064 | if (i < 0) | |
1065 | { | |
1066 | store1 = group->store1_n; | |
1067 | store2 = group->store2_n; | |
d26c7090 | 1068 | escaped = group->escaped_n; |
6fb5fa3c DB |
1069 | ai = -i; |
1070 | } | |
1071 | else | |
1072 | { | |
1073 | store1 = group->store1_p; | |
1074 | store2 = group->store2_p; | |
d26c7090 | 1075 | escaped = group->escaped_p; |
6fb5fa3c DB |
1076 | ai = i; |
1077 | } | |
b8698a0f | 1078 | |
fcaa4ca4 | 1079 | if (!bitmap_set_bit (store1, ai)) |
6fb5fa3c | 1080 | bitmap_set_bit (store2, ai); |
b8698a0f | 1081 | else |
6fb5fa3c | 1082 | { |
6fb5fa3c DB |
1083 | if (i < 0) |
1084 | { | |
1085 | if (group->offset_map_size_n < ai) | |
1086 | group->offset_map_size_n = ai; | |
1087 | } | |
1088 | else | |
1089 | { | |
1090 | if (group->offset_map_size_p < ai) | |
1091 | group->offset_map_size_p = ai; | |
1092 | } | |
1093 | } | |
d26c7090 ER |
1094 | if (expr_escapes) |
1095 | bitmap_set_bit (escaped, ai); | |
6fb5fa3c DB |
1096 | } |
1097 | } | |
1098 | ||
d26c7090 ER |
1099 | static void |
1100 | reset_active_stores (void) | |
1101 | { | |
1102 | active_local_stores = NULL; | |
1103 | active_local_stores_len = 0; | |
1104 | } | |
6fb5fa3c | 1105 | |
d26c7090 | 1106 | /* Free all READ_REC of the LAST_INSN of BB_INFO. */ |
6fb5fa3c DB |
1107 | |
1108 | static void | |
d26c7090 | 1109 | free_read_records (bb_info_t bb_info) |
6fb5fa3c DB |
1110 | { |
1111 | insn_info_t insn_info = bb_info->last_insn; | |
1112 | read_info_t *ptr = &insn_info->read_rec; | |
6fb5fa3c DB |
1113 | while (*ptr) |
1114 | { | |
1115 | read_info_t next = (*ptr)->next; | |
4862826d | 1116 | if ((*ptr)->alias_set == 0) |
6fb5fa3c DB |
1117 | { |
1118 | pool_free (read_info_pool, *ptr); | |
1119 | *ptr = next; | |
d26c7090 | 1120 | } |
b8698a0f | 1121 | else |
d26c7090 | 1122 | ptr = &(*ptr)->next; |
6fb5fa3c | 1123 | } |
d26c7090 ER |
1124 | } |
1125 | ||
1126 | /* Set the BB_INFO so that the last insn is marked as a wild read. */ | |
1127 | ||
1128 | static void | |
1129 | add_wild_read (bb_info_t bb_info) | |
1130 | { | |
1131 | insn_info_t insn_info = bb_info->last_insn; | |
6fb5fa3c | 1132 | insn_info->wild_read = true; |
d26c7090 ER |
1133 | free_read_records (bb_info); |
1134 | reset_active_stores (); | |
6fb5fa3c DB |
1135 | } |
1136 | ||
d26c7090 ER |
1137 | /* Set the BB_INFO so that the last insn is marked as a wild read of |
1138 | non-frame locations. */ | |
1139 | ||
1140 | static void | |
1141 | add_non_frame_wild_read (bb_info_t bb_info) | |
1142 | { | |
1143 | insn_info_t insn_info = bb_info->last_insn; | |
1144 | insn_info->non_frame_wild_read = true; | |
1145 | free_read_records (bb_info); | |
1146 | reset_active_stores (); | |
1147 | } | |
6fb5fa3c | 1148 | |
50f0f366 EB |
1149 | /* Return true if X is a constant or one of the registers that behave |
1150 | as a constant over the life of a function. This is equivalent to | |
1151 | !rtx_varies_p for memory addresses. */ | |
6fb5fa3c DB |
1152 | |
1153 | static bool | |
1154 | const_or_frame_p (rtx x) | |
1155 | { | |
d8116890 KZ |
1156 | if (CONSTANT_P (x)) |
1157 | return true; | |
1158 | ||
1159 | if (GET_CODE (x) == REG) | |
6fb5fa3c | 1160 | { |
6fb5fa3c DB |
1161 | /* Note that we have to test for the actual rtx used for the frame |
1162 | and arg pointers and not just the register number in case we have | |
1163 | eliminated the frame and/or arg pointer and are using it | |
1164 | for pseudos. */ | |
1165 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx | |
1166 | /* The arg pointer varies if it is not a fixed register. */ | |
1167 | || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
1168 | || x == pic_offset_table_rtx) | |
1169 | return true; | |
1170 | return false; | |
6fb5fa3c | 1171 | } |
d8116890 KZ |
1172 | |
1173 | return false; | |
6fb5fa3c DB |
1174 | } |
1175 | ||
b8698a0f L |
1176 | /* Take all reasonable action to put the address of MEM into the form |
1177 | that we can do analysis on. | |
6fb5fa3c DB |
1178 | |
1179 | The gold standard is to get the address into the form: address + | |
1180 | OFFSET where address is something that rtx_varies_p considers a | |
1181 | constant. When we can get the address in this form, we can do | |
1182 | global analysis on it. Note that for constant bases, address is | |
1183 | not actually returned, only the group_id. The address can be | |
1184 | obtained from that. | |
1185 | ||
1186 | If that fails, we try cselib to get a value we can at least use | |
b8698a0f L |
1187 | locally. If that fails we return false. |
1188 | ||
6fb5fa3c DB |
1189 | The GROUP_ID is set to -1 for cselib bases and the index of the |
1190 | group for non_varying bases. | |
1191 | ||
1192 | FOR_READ is true if this is a mem read and false if not. */ | |
1193 | ||
1194 | static bool | |
1195 | canon_address (rtx mem, | |
4862826d | 1196 | alias_set_type *alias_set_out, |
6fb5fa3c | 1197 | int *group_id, |
b8698a0f | 1198 | HOST_WIDE_INT *offset, |
6fb5fa3c DB |
1199 | cselib_val **base) |
1200 | { | |
ef4bddc2 | 1201 | machine_mode address_mode = get_address_mode (mem); |
6fb5fa3c DB |
1202 | rtx mem_address = XEXP (mem, 0); |
1203 | rtx expanded_address, address; | |
403c7520 JJ |
1204 | int expanded; |
1205 | ||
6fb5fa3c DB |
1206 | *alias_set_out = 0; |
1207 | ||
4deef538 | 1208 | cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem)); |
6fb5fa3c | 1209 | |
456610d3 | 1210 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1211 | { |
1212 | fprintf (dump_file, " mem: "); | |
1213 | print_inline_rtx (dump_file, mem_address, 0); | |
1214 | fprintf (dump_file, "\n"); | |
1215 | } | |
1216 | ||
403c7520 JJ |
1217 | /* First see if just canon_rtx (mem_address) is const or frame, |
1218 | if not, try cselib_expand_value_rtx and call canon_rtx on that. */ | |
1219 | address = NULL_RTX; | |
1220 | for (expanded = 0; expanded < 2; expanded++) | |
1221 | { | |
1222 | if (expanded) | |
1223 | { | |
1224 | /* Use cselib to replace all of the reg references with the full | |
b8698a0f | 1225 | expression. This will take care of the case where we have |
6fb5fa3c | 1226 | |
403c7520 JJ |
1227 | r_x = base + offset; |
1228 | val = *r_x; | |
b8698a0f L |
1229 | |
1230 | by making it into | |
6fb5fa3c | 1231 | |
403c7520 | 1232 | val = *(base + offset); */ |
6fb5fa3c | 1233 | |
403c7520 JJ |
1234 | expanded_address = cselib_expand_value_rtx (mem_address, |
1235 | scratch, 5); | |
6fb5fa3c | 1236 | |
403c7520 JJ |
1237 | /* If this fails, just go with the address from first |
1238 | iteration. */ | |
1239 | if (!expanded_address) | |
1240 | break; | |
1241 | } | |
1242 | else | |
1243 | expanded_address = mem_address; | |
6fb5fa3c | 1244 | |
403c7520 JJ |
1245 | /* Split the address into canonical BASE + OFFSET terms. */ |
1246 | address = canon_rtx (expanded_address); | |
6fb5fa3c | 1247 | |
403c7520 | 1248 | *offset = 0; |
6fb5fa3c | 1249 | |
456610d3 | 1250 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1251 | { |
1252 | if (expanded) | |
1253 | { | |
1254 | fprintf (dump_file, "\n after cselib_expand address: "); | |
1255 | print_inline_rtx (dump_file, expanded_address, 0); | |
1256 | fprintf (dump_file, "\n"); | |
1257 | } | |
6fb5fa3c | 1258 | |
403c7520 JJ |
1259 | fprintf (dump_file, "\n after canon_rtx address: "); |
1260 | print_inline_rtx (dump_file, address, 0); | |
1261 | fprintf (dump_file, "\n"); | |
1262 | } | |
6fb5fa3c | 1263 | |
403c7520 JJ |
1264 | if (GET_CODE (address) == CONST) |
1265 | address = XEXP (address, 0); | |
6fb5fa3c | 1266 | |
403c7520 JJ |
1267 | if (GET_CODE (address) == PLUS |
1268 | && CONST_INT_P (XEXP (address, 1))) | |
1269 | { | |
1270 | *offset = INTVAL (XEXP (address, 1)); | |
1271 | address = XEXP (address, 0); | |
1272 | } | |
6fb5fa3c | 1273 | |
09e881c9 BE |
1274 | if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem)) |
1275 | && const_or_frame_p (address)) | |
6fb5fa3c | 1276 | { |
403c7520 JJ |
1277 | group_info_t group = get_group_info (address); |
1278 | ||
456610d3 | 1279 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1280 | fprintf (dump_file, " gid=%d offset=%d \n", |
1281 | group->id, (int)*offset); | |
1282 | *base = NULL; | |
1283 | *group_id = group->id; | |
1284 | return true; | |
6fb5fa3c | 1285 | } |
403c7520 JJ |
1286 | } |
1287 | ||
4deef538 | 1288 | *base = cselib_lookup (address, address_mode, true, GET_MODE (mem)); |
403c7520 JJ |
1289 | *group_id = -1; |
1290 | ||
1291 | if (*base == NULL) | |
1292 | { | |
456610d3 | 1293 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1294 | fprintf (dump_file, " no cselib val - should be a wild read.\n"); |
1295 | return false; | |
6fb5fa3c | 1296 | } |
456610d3 | 1297 | if (dump_file && (dump_flags & TDF_DETAILS)) |
5440c0e7 AO |
1298 | fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n", |
1299 | (*base)->uid, (*base)->hash, (int)*offset); | |
6fb5fa3c DB |
1300 | return true; |
1301 | } | |
1302 | ||
1303 | ||
1304 | /* Clear the rhs field from the active_local_stores array. */ | |
1305 | ||
1306 | static void | |
1307 | clear_rhs_from_active_local_stores (void) | |
1308 | { | |
1309 | insn_info_t ptr = active_local_stores; | |
1310 | ||
1311 | while (ptr) | |
1312 | { | |
1313 | store_info_t store_info = ptr->store_rec; | |
1314 | /* Skip the clobbers. */ | |
1315 | while (!store_info->is_set) | |
1316 | store_info = store_info->next; | |
1317 | ||
1318 | store_info->rhs = NULL; | |
8dd5516b | 1319 | store_info->const_rhs = NULL; |
6fb5fa3c DB |
1320 | |
1321 | ptr = ptr->next_local_store; | |
1322 | } | |
1323 | } | |
1324 | ||
1325 | ||
8dd5516b JJ |
1326 | /* Mark byte POS bytes from the beginning of store S_INFO as unneeded. */ |
1327 | ||
1328 | static inline void | |
1329 | set_position_unneeded (store_info_t s_info, int pos) | |
1330 | { | |
1331 | if (__builtin_expect (s_info->is_large, false)) | |
1332 | { | |
fcaa4ca4 NF |
1333 | if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos)) |
1334 | s_info->positions_needed.large.count++; | |
8dd5516b JJ |
1335 | } |
1336 | else | |
1337 | s_info->positions_needed.small_bitmask | |
1338 | &= ~(((unsigned HOST_WIDE_INT) 1) << pos); | |
1339 | } | |
1340 | ||
1341 | /* Mark the whole store S_INFO as unneeded. */ | |
1342 | ||
1343 | static inline void | |
1344 | set_all_positions_unneeded (store_info_t s_info) | |
1345 | { | |
1346 | if (__builtin_expect (s_info->is_large, false)) | |
1347 | { | |
1348 | int pos, end = s_info->end - s_info->begin; | |
1349 | for (pos = 0; pos < end; pos++) | |
dc491a25 | 1350 | bitmap_set_bit (s_info->positions_needed.large.bmap, pos); |
8dd5516b JJ |
1351 | s_info->positions_needed.large.count = end; |
1352 | } | |
1353 | else | |
1354 | s_info->positions_needed.small_bitmask = (unsigned HOST_WIDE_INT) 0; | |
1355 | } | |
1356 | ||
1357 | /* Return TRUE if any bytes from S_INFO store are needed. */ | |
1358 | ||
1359 | static inline bool | |
1360 | any_positions_needed_p (store_info_t s_info) | |
1361 | { | |
1362 | if (__builtin_expect (s_info->is_large, false)) | |
1363 | return (s_info->positions_needed.large.count | |
1364 | < s_info->end - s_info->begin); | |
1365 | else | |
1366 | return (s_info->positions_needed.small_bitmask | |
1367 | != (unsigned HOST_WIDE_INT) 0); | |
1368 | } | |
1369 | ||
1370 | /* Return TRUE if all bytes START through START+WIDTH-1 from S_INFO | |
1371 | store are needed. */ | |
1372 | ||
1373 | static inline bool | |
1374 | all_positions_needed_p (store_info_t s_info, int start, int width) | |
1375 | { | |
1376 | if (__builtin_expect (s_info->is_large, false)) | |
1377 | { | |
1378 | int end = start + width; | |
1379 | while (start < end) | |
dc491a25 | 1380 | if (bitmap_bit_p (s_info->positions_needed.large.bmap, start++)) |
8dd5516b JJ |
1381 | return false; |
1382 | return true; | |
1383 | } | |
1384 | else | |
1385 | { | |
1386 | unsigned HOST_WIDE_INT mask = lowpart_bitmask (width) << start; | |
1387 | return (s_info->positions_needed.small_bitmask & mask) == mask; | |
1388 | } | |
1389 | } | |
1390 | ||
1391 | ||
ef4bddc2 | 1392 | static rtx get_stored_val (store_info_t, machine_mode, HOST_WIDE_INT, |
8dd5516b JJ |
1393 | HOST_WIDE_INT, basic_block, bool); |
1394 | ||
1395 | ||
6fb5fa3c DB |
1396 | /* BODY is an instruction pattern that belongs to INSN. Return 1 if |
1397 | there is a candidate store, after adding it to the appropriate | |
1398 | local store group if so. */ | |
1399 | ||
1400 | static int | |
1401 | record_store (rtx body, bb_info_t bb_info) | |
1402 | { | |
6216f94e | 1403 | rtx mem, rhs, const_rhs, mem_addr; |
6fb5fa3c DB |
1404 | HOST_WIDE_INT offset = 0; |
1405 | HOST_WIDE_INT width = 0; | |
4862826d | 1406 | alias_set_type spill_alias_set; |
6fb5fa3c DB |
1407 | insn_info_t insn_info = bb_info->last_insn; |
1408 | store_info_t store_info = NULL; | |
1409 | int group_id; | |
1410 | cselib_val *base = NULL; | |
8dd5516b | 1411 | insn_info_t ptr, last, redundant_reason; |
6fb5fa3c DB |
1412 | bool store_is_unused; |
1413 | ||
1414 | if (GET_CODE (body) != SET && GET_CODE (body) != CLOBBER) | |
1415 | return 0; | |
1416 | ||
8dd5516b JJ |
1417 | mem = SET_DEST (body); |
1418 | ||
6fb5fa3c DB |
1419 | /* If this is not used, then this cannot be used to keep the insn |
1420 | from being deleted. On the other hand, it does provide something | |
1421 | that can be used to prove that another store is dead. */ | |
1422 | store_is_unused | |
8dd5516b | 1423 | = (find_reg_note (insn_info->insn, REG_UNUSED, mem) != NULL); |
6fb5fa3c DB |
1424 | |
1425 | /* Check whether that value is a suitable memory location. */ | |
6fb5fa3c DB |
1426 | if (!MEM_P (mem)) |
1427 | { | |
1428 | /* If the set or clobber is unused, then it does not effect our | |
1429 | ability to get rid of the entire insn. */ | |
1430 | if (!store_is_unused) | |
1431 | insn_info->cannot_delete = true; | |
1432 | return 0; | |
1433 | } | |
1434 | ||
1435 | /* At this point we know mem is a mem. */ | |
1436 | if (GET_MODE (mem) == BLKmode) | |
1437 | { | |
1438 | if (GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
1439 | { | |
456610d3 | 1440 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1441 | fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n"); |
1442 | add_wild_read (bb_info); | |
1443 | insn_info->cannot_delete = true; | |
8dd5516b | 1444 | return 0; |
6fb5fa3c | 1445 | } |
8dd5516b JJ |
1446 | /* Handle (set (mem:BLK (addr) [... S36 ...]) (const_int 0)) |
1447 | as memset (addr, 0, 36); */ | |
f5541398 RS |
1448 | else if (!MEM_SIZE_KNOWN_P (mem) |
1449 | || MEM_SIZE (mem) <= 0 | |
1450 | || MEM_SIZE (mem) > MAX_OFFSET | |
8dd5516b | 1451 | || GET_CODE (body) != SET |
8dd5516b | 1452 | || !CONST_INT_P (SET_SRC (body))) |
6fb5fa3c | 1453 | { |
8dd5516b JJ |
1454 | if (!store_is_unused) |
1455 | { | |
1456 | /* If the set or clobber is unused, then it does not effect our | |
1457 | ability to get rid of the entire insn. */ | |
1458 | insn_info->cannot_delete = true; | |
1459 | clear_rhs_from_active_local_stores (); | |
1460 | } | |
1461 | return 0; | |
6fb5fa3c | 1462 | } |
6fb5fa3c DB |
1463 | } |
1464 | ||
1465 | /* We can still process a volatile mem, we just cannot delete it. */ | |
1466 | if (MEM_VOLATILE_P (mem)) | |
8dd5516b | 1467 | insn_info->cannot_delete = true; |
6fb5fa3c DB |
1468 | |
1469 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
1470 | { | |
1471 | clear_rhs_from_active_local_stores (); | |
1472 | return 0; | |
1473 | } | |
1474 | ||
8dd5516b | 1475 | if (GET_MODE (mem) == BLKmode) |
f5541398 | 1476 | width = MEM_SIZE (mem); |
8dd5516b | 1477 | else |
6f557e0e | 1478 | width = GET_MODE_SIZE (GET_MODE (mem)); |
6fb5fa3c DB |
1479 | |
1480 | if (spill_alias_set) | |
1481 | { | |
1482 | bitmap store1 = clear_alias_group->store1_p; | |
1483 | bitmap store2 = clear_alias_group->store2_p; | |
8dd5516b JJ |
1484 | |
1485 | gcc_assert (GET_MODE (mem) != BLKmode); | |
b8698a0f | 1486 | |
fcaa4ca4 | 1487 | if (!bitmap_set_bit (store1, spill_alias_set)) |
6fb5fa3c | 1488 | bitmap_set_bit (store2, spill_alias_set); |
b8698a0f | 1489 | |
6fb5fa3c DB |
1490 | if (clear_alias_group->offset_map_size_p < spill_alias_set) |
1491 | clear_alias_group->offset_map_size_p = spill_alias_set; | |
b8698a0f | 1492 | |
f883e0a7 | 1493 | store_info = (store_info_t) pool_alloc (rtx_store_info_pool); |
6fb5fa3c | 1494 | |
456610d3 | 1495 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 1496 | fprintf (dump_file, " processing spill store %d(%s)\n", |
4862826d | 1497 | (int) spill_alias_set, GET_MODE_NAME (GET_MODE (mem))); |
6fb5fa3c DB |
1498 | } |
1499 | else if (group_id >= 0) | |
1500 | { | |
1501 | /* In the restrictive case where the base is a constant or the | |
1502 | frame pointer we can do global analysis. */ | |
b8698a0f L |
1503 | |
1504 | group_info_t group | |
9771b263 | 1505 | = rtx_group_vec[group_id]; |
d26c7090 | 1506 | tree expr = MEM_EXPR (mem); |
b8698a0f | 1507 | |
f883e0a7 | 1508 | store_info = (store_info_t) pool_alloc (rtx_store_info_pool); |
d26c7090 | 1509 | set_usage_bits (group, offset, width, expr); |
6fb5fa3c | 1510 | |
456610d3 | 1511 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1512 | fprintf (dump_file, " processing const base store gid=%d[%d..%d)\n", |
1513 | group_id, (int)offset, (int)(offset+width)); | |
1514 | } | |
1515 | else | |
1516 | { | |
9e412ca3 | 1517 | if (may_be_sp_based_p (XEXP (mem, 0))) |
50f0f366 | 1518 | insn_info->stack_pointer_based = true; |
6fb5fa3c | 1519 | insn_info->contains_cselib_groups = true; |
50f0f366 | 1520 | |
f883e0a7 | 1521 | store_info = (store_info_t) pool_alloc (cse_store_info_pool); |
6fb5fa3c DB |
1522 | group_id = -1; |
1523 | ||
456610d3 | 1524 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1525 | fprintf (dump_file, " processing cselib store [%d..%d)\n", |
1526 | (int)offset, (int)(offset+width)); | |
1527 | } | |
1528 | ||
8dd5516b JJ |
1529 | const_rhs = rhs = NULL_RTX; |
1530 | if (GET_CODE (body) == SET | |
1531 | /* No place to keep the value after ra. */ | |
1532 | && !reload_completed | |
1533 | && (REG_P (SET_SRC (body)) | |
1534 | || GET_CODE (SET_SRC (body)) == SUBREG | |
1535 | || CONSTANT_P (SET_SRC (body))) | |
1536 | && !MEM_VOLATILE_P (mem) | |
1537 | /* Sometimes the store and reload is used for truncation and | |
1538 | rounding. */ | |
1539 | && !(FLOAT_MODE_P (GET_MODE (mem)) && (flag_float_store))) | |
1540 | { | |
1541 | rhs = SET_SRC (body); | |
1542 | if (CONSTANT_P (rhs)) | |
1543 | const_rhs = rhs; | |
1544 | else if (body == PATTERN (insn_info->insn)) | |
1545 | { | |
1546 | rtx tem = find_reg_note (insn_info->insn, REG_EQUAL, NULL_RTX); | |
1547 | if (tem && CONSTANT_P (XEXP (tem, 0))) | |
1548 | const_rhs = XEXP (tem, 0); | |
1549 | } | |
1550 | if (const_rhs == NULL_RTX && REG_P (rhs)) | |
1551 | { | |
1552 | rtx tem = cselib_expand_value_rtx (rhs, scratch, 5); | |
1553 | ||
1554 | if (tem && CONSTANT_P (tem)) | |
1555 | const_rhs = tem; | |
1556 | } | |
1557 | } | |
1558 | ||
6fb5fa3c DB |
1559 | /* Check to see if this stores causes some other stores to be |
1560 | dead. */ | |
1561 | ptr = active_local_stores; | |
1562 | last = NULL; | |
8dd5516b | 1563 | redundant_reason = NULL; |
6216f94e JJ |
1564 | mem = canon_rtx (mem); |
1565 | /* For alias_set != 0 canon_true_dependence should be never called. */ | |
1566 | if (spill_alias_set) | |
1567 | mem_addr = NULL_RTX; | |
1568 | else | |
1569 | { | |
1570 | if (group_id < 0) | |
1571 | mem_addr = base->val_rtx; | |
1572 | else | |
1573 | { | |
1574 | group_info_t group | |
9771b263 | 1575 | = rtx_group_vec[group_id]; |
6216f94e JJ |
1576 | mem_addr = group->canon_base_addr; |
1577 | } | |
ff1803c1 WM |
1578 | /* get_addr can only handle VALUE but cannot handle expr like: |
1579 | VALUE + OFFSET, so call get_addr to get original addr for | |
1580 | mem_addr before plus_constant. */ | |
1581 | mem_addr = get_addr (mem_addr); | |
6216f94e | 1582 | if (offset) |
372d6395 | 1583 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
6216f94e | 1584 | } |
6fb5fa3c DB |
1585 | |
1586 | while (ptr) | |
1587 | { | |
1588 | insn_info_t next = ptr->next_local_store; | |
1589 | store_info_t s_info = ptr->store_rec; | |
60564289 | 1590 | bool del = true; |
6fb5fa3c DB |
1591 | |
1592 | /* Skip the clobbers. We delete the active insn if this insn | |
6ed3da00 | 1593 | shadows the set. To have been put on the active list, it |
6fb5fa3c DB |
1594 | has exactly on set. */ |
1595 | while (!s_info->is_set) | |
1596 | s_info = s_info->next; | |
1597 | ||
1598 | if (s_info->alias_set != spill_alias_set) | |
60564289 | 1599 | del = false; |
6fb5fa3c DB |
1600 | else if (s_info->alias_set) |
1601 | { | |
b8698a0f | 1602 | struct clear_alias_mode_holder *entry |
6fb5fa3c DB |
1603 | = clear_alias_set_lookup (s_info->alias_set); |
1604 | /* Generally, spills cannot be processed if and of the | |
1605 | references to the slot have a different mode. But if | |
1606 | we are in the same block and mode is exactly the same | |
1607 | between this store and one before in the same block, | |
1608 | we can still delete it. */ | |
1609 | if ((GET_MODE (mem) == GET_MODE (s_info->mem)) | |
1610 | && (GET_MODE (mem) == entry->mode)) | |
1611 | { | |
60564289 | 1612 | del = true; |
8dd5516b | 1613 | set_all_positions_unneeded (s_info); |
6fb5fa3c | 1614 | } |
456610d3 | 1615 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 1616 | fprintf (dump_file, " trying spill store in insn=%d alias_set=%d\n", |
4862826d | 1617 | INSN_UID (ptr->insn), (int) s_info->alias_set); |
6fb5fa3c | 1618 | } |
b8698a0f | 1619 | else if ((s_info->group_id == group_id) |
6fb5fa3c DB |
1620 | && (s_info->cse_base == base)) |
1621 | { | |
1622 | HOST_WIDE_INT i; | |
456610d3 | 1623 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 1624 | fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n", |
b8698a0f | 1625 | INSN_UID (ptr->insn), s_info->group_id, |
6fb5fa3c | 1626 | (int)s_info->begin, (int)s_info->end); |
8dd5516b JJ |
1627 | |
1628 | /* Even if PTR won't be eliminated as unneeded, if both | |
1629 | PTR and this insn store the same constant value, we might | |
1630 | eliminate this insn instead. */ | |
1631 | if (s_info->const_rhs | |
1632 | && const_rhs | |
1633 | && offset >= s_info->begin | |
1634 | && offset + width <= s_info->end | |
1635 | && all_positions_needed_p (s_info, offset - s_info->begin, | |
1636 | width)) | |
1637 | { | |
1638 | if (GET_MODE (mem) == BLKmode) | |
1639 | { | |
1640 | if (GET_MODE (s_info->mem) == BLKmode | |
1641 | && s_info->const_rhs == const_rhs) | |
1642 | redundant_reason = ptr; | |
1643 | } | |
1644 | else if (s_info->const_rhs == const0_rtx | |
1645 | && const_rhs == const0_rtx) | |
1646 | redundant_reason = ptr; | |
1647 | else | |
1648 | { | |
1649 | rtx val; | |
1650 | start_sequence (); | |
1651 | val = get_stored_val (s_info, GET_MODE (mem), | |
1652 | offset, offset + width, | |
1653 | BLOCK_FOR_INSN (insn_info->insn), | |
1654 | true); | |
1655 | if (get_insns () != NULL) | |
1656 | val = NULL_RTX; | |
1657 | end_sequence (); | |
1658 | if (val && rtx_equal_p (val, const_rhs)) | |
1659 | redundant_reason = ptr; | |
1660 | } | |
1661 | } | |
1662 | ||
1663 | for (i = MAX (offset, s_info->begin); | |
1664 | i < offset + width && i < s_info->end; | |
1665 | i++) | |
1666 | set_position_unneeded (s_info, i - s_info->begin); | |
6fb5fa3c DB |
1667 | } |
1668 | else if (s_info->rhs) | |
1669 | /* Need to see if it is possible for this store to overwrite | |
1670 | the value of store_info. If it is, set the rhs to NULL to | |
1671 | keep it from being used to remove a load. */ | |
1672 | { | |
b8698a0f | 1673 | if (canon_true_dependence (s_info->mem, |
6fb5fa3c DB |
1674 | GET_MODE (s_info->mem), |
1675 | s_info->mem_addr, | |
53d9622b | 1676 | mem, mem_addr)) |
8dd5516b JJ |
1677 | { |
1678 | s_info->rhs = NULL; | |
1679 | s_info->const_rhs = NULL; | |
1680 | } | |
6fb5fa3c | 1681 | } |
6216f94e | 1682 | |
6fb5fa3c DB |
1683 | /* An insn can be deleted if every position of every one of |
1684 | its s_infos is zero. */ | |
1b6fa860 | 1685 | if (any_positions_needed_p (s_info)) |
60564289 | 1686 | del = false; |
8dd5516b | 1687 | |
60564289 | 1688 | if (del) |
6fb5fa3c DB |
1689 | { |
1690 | insn_info_t insn_to_delete = ptr; | |
b8698a0f | 1691 | |
dabd47e7 | 1692 | active_local_stores_len--; |
6fb5fa3c DB |
1693 | if (last) |
1694 | last->next_local_store = ptr->next_local_store; | |
1695 | else | |
1696 | active_local_stores = ptr->next_local_store; | |
b8698a0f | 1697 | |
1b6fa860 JJ |
1698 | if (!insn_to_delete->cannot_delete) |
1699 | delete_dead_store_insn (insn_to_delete); | |
6fb5fa3c DB |
1700 | } |
1701 | else | |
1702 | last = ptr; | |
b8698a0f | 1703 | |
6fb5fa3c DB |
1704 | ptr = next; |
1705 | } | |
b8698a0f | 1706 | |
6fb5fa3c DB |
1707 | /* Finish filling in the store_info. */ |
1708 | store_info->next = insn_info->store_rec; | |
1709 | insn_info->store_rec = store_info; | |
6216f94e | 1710 | store_info->mem = mem; |
6fb5fa3c | 1711 | store_info->alias_set = spill_alias_set; |
6216f94e | 1712 | store_info->mem_addr = mem_addr; |
6fb5fa3c | 1713 | store_info->cse_base = base; |
8dd5516b JJ |
1714 | if (width > HOST_BITS_PER_WIDE_INT) |
1715 | { | |
1716 | store_info->is_large = true; | |
1717 | store_info->positions_needed.large.count = 0; | |
3f9b14ff | 1718 | store_info->positions_needed.large.bmap = BITMAP_ALLOC (&dse_bitmap_obstack); |
8dd5516b JJ |
1719 | } |
1720 | else | |
1721 | { | |
1722 | store_info->is_large = false; | |
1723 | store_info->positions_needed.small_bitmask = lowpart_bitmask (width); | |
1724 | } | |
6fb5fa3c DB |
1725 | store_info->group_id = group_id; |
1726 | store_info->begin = offset; | |
1727 | store_info->end = offset + width; | |
1728 | store_info->is_set = GET_CODE (body) == SET; | |
8dd5516b JJ |
1729 | store_info->rhs = rhs; |
1730 | store_info->const_rhs = const_rhs; | |
1731 | store_info->redundant_reason = redundant_reason; | |
6fb5fa3c | 1732 | |
6fb5fa3c DB |
1733 | /* If this is a clobber, we return 0. We will only be able to |
1734 | delete this insn if there is only one store USED store, but we | |
1735 | can use the clobber to delete other stores earlier. */ | |
1736 | return store_info->is_set ? 1 : 0; | |
1737 | } | |
1738 | ||
1739 | ||
1740 | static void | |
1741 | dump_insn_info (const char * start, insn_info_t insn_info) | |
1742 | { | |
b8698a0f | 1743 | fprintf (dump_file, "%s insn=%d %s\n", start, |
6fb5fa3c DB |
1744 | INSN_UID (insn_info->insn), |
1745 | insn_info->store_rec ? "has store" : "naked"); | |
1746 | } | |
1747 | ||
1748 | ||
8660aaae EC |
1749 | /* If the modes are different and the value's source and target do not |
1750 | line up, we need to extract the value from lower part of the rhs of | |
1751 | the store, shift it, and then put it into a form that can be shoved | |
1752 | into the read_insn. This function generates a right SHIFT of a | |
1753 | value that is at least ACCESS_SIZE bytes wide of READ_MODE. The | |
1754 | shift sequence is returned or NULL if we failed to find a | |
1755 | shift. */ | |
1756 | ||
1757 | static rtx | |
18b526e8 | 1758 | find_shift_sequence (int access_size, |
8660aaae | 1759 | store_info_t store_info, |
ef4bddc2 | 1760 | machine_mode read_mode, |
8dd5516b | 1761 | int shift, bool speed, bool require_cst) |
8660aaae | 1762 | { |
ef4bddc2 RS |
1763 | machine_mode store_mode = GET_MODE (store_info->mem); |
1764 | machine_mode new_mode; | |
18b526e8 | 1765 | rtx read_reg = NULL; |
8660aaae EC |
1766 | |
1767 | /* Some machines like the x86 have shift insns for each size of | |
1768 | operand. Other machines like the ppc or the ia-64 may only have | |
1769 | shift insns that shift values within 32 or 64 bit registers. | |
1770 | This loop tries to find the smallest shift insn that will right | |
1771 | justify the value we want to read but is available in one insn on | |
1772 | the machine. */ | |
1773 | ||
18b526e8 RS |
1774 | for (new_mode = smallest_mode_for_size (access_size * BITS_PER_UNIT, |
1775 | MODE_INT); | |
1776 | GET_MODE_BITSIZE (new_mode) <= BITS_PER_WORD; | |
1777 | new_mode = GET_MODE_WIDER_MODE (new_mode)) | |
8660aaae | 1778 | { |
dc01c3d1 DM |
1779 | rtx target, new_reg, new_lhs; |
1780 | rtx_insn *shift_seq, *insn; | |
d898d29b | 1781 | int cost; |
348eea5f | 1782 | |
72a2609f JJ |
1783 | /* If a constant was stored into memory, try to simplify it here, |
1784 | otherwise the cost of the shift might preclude this optimization | |
1785 | e.g. at -Os, even when no actual shift will be needed. */ | |
8dd5516b | 1786 | if (store_info->const_rhs) |
72a2609f JJ |
1787 | { |
1788 | unsigned int byte = subreg_lowpart_offset (new_mode, store_mode); | |
8dd5516b JJ |
1789 | rtx ret = simplify_subreg (new_mode, store_info->const_rhs, |
1790 | store_mode, byte); | |
72a2609f JJ |
1791 | if (ret && CONSTANT_P (ret)) |
1792 | { | |
1793 | ret = simplify_const_binary_operation (LSHIFTRT, new_mode, | |
1794 | ret, GEN_INT (shift)); | |
1795 | if (ret && CONSTANT_P (ret)) | |
1796 | { | |
1797 | byte = subreg_lowpart_offset (read_mode, new_mode); | |
1798 | ret = simplify_subreg (read_mode, ret, new_mode, byte); | |
1799 | if (ret && CONSTANT_P (ret) | |
5e8f01f4 | 1800 | && set_src_cost (ret, speed) <= COSTS_N_INSNS (1)) |
72a2609f JJ |
1801 | return ret; |
1802 | } | |
1803 | } | |
1804 | } | |
1805 | ||
8dd5516b JJ |
1806 | if (require_cst) |
1807 | return NULL_RTX; | |
1808 | ||
18b526e8 RS |
1809 | /* Try a wider mode if truncating the store mode to NEW_MODE |
1810 | requires a real instruction. */ | |
1811 | if (GET_MODE_BITSIZE (new_mode) < GET_MODE_BITSIZE (store_mode) | |
d0edd768 | 1812 | && !TRULY_NOOP_TRUNCATION_MODES_P (new_mode, store_mode)) |
348eea5f RS |
1813 | continue; |
1814 | ||
18b526e8 RS |
1815 | /* Also try a wider mode if the necessary punning is either not |
1816 | desirable or not possible. */ | |
1817 | if (!CONSTANT_P (store_info->rhs) | |
1818 | && !MODES_TIEABLE_P (new_mode, store_mode)) | |
1819 | continue; | |
18b526e8 | 1820 | |
348eea5f | 1821 | new_reg = gen_reg_rtx (new_mode); |
8660aaae EC |
1822 | |
1823 | start_sequence (); | |
1824 | ||
1825 | /* In theory we could also check for an ashr. Ian Taylor knows | |
1826 | of one dsp where the cost of these two was not the same. But | |
1827 | this really is a rare case anyway. */ | |
1828 | target = expand_binop (new_mode, lshr_optab, new_reg, | |
1829 | GEN_INT (shift), new_reg, 1, OPTAB_DIRECT); | |
1830 | ||
c6f3019a RS |
1831 | shift_seq = get_insns (); |
1832 | end_sequence (); | |
8660aaae | 1833 | |
c6f3019a RS |
1834 | if (target != new_reg || shift_seq == NULL) |
1835 | continue; | |
1836 | ||
1837 | cost = 0; | |
1838 | for (insn = shift_seq; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
1839 | if (INSN_P (insn)) | |
f40751dd | 1840 | cost += insn_rtx_cost (PATTERN (insn), speed); |
c6f3019a RS |
1841 | |
1842 | /* The computation up to here is essentially independent | |
1843 | of the arguments and could be precomputed. It may | |
1844 | not be worth doing so. We could precompute if | |
1845 | worthwhile or at least cache the results. The result | |
06acf7d0 RS |
1846 | technically depends on both SHIFT and ACCESS_SIZE, |
1847 | but in practice the answer will depend only on ACCESS_SIZE. */ | |
c6f3019a RS |
1848 | |
1849 | if (cost > COSTS_N_INSNS (1)) | |
1850 | continue; | |
1851 | ||
d898d29b JJ |
1852 | new_lhs = extract_low_bits (new_mode, store_mode, |
1853 | copy_rtx (store_info->rhs)); | |
1854 | if (new_lhs == NULL_RTX) | |
1855 | continue; | |
1856 | ||
c6f3019a RS |
1857 | /* We found an acceptable shift. Generate a move to |
1858 | take the value from the store and put it into the | |
1859 | shift pseudo, then shift it, then generate another | |
1860 | move to put in into the target of the read. */ | |
18b526e8 | 1861 | emit_move_insn (new_reg, new_lhs); |
c6f3019a | 1862 | emit_insn (shift_seq); |
18b526e8 | 1863 | read_reg = extract_low_bits (read_mode, new_mode, new_reg); |
c6f3019a | 1864 | break; |
8660aaae EC |
1865 | } |
1866 | ||
18b526e8 | 1867 | return read_reg; |
8660aaae EC |
1868 | } |
1869 | ||
1870 | ||
02b47899 KZ |
1871 | /* Call back for note_stores to find the hard regs set or clobbered by |
1872 | insn. Data is a bitmap of the hardregs set so far. */ | |
1873 | ||
1874 | static void | |
1875 | look_for_hardregs (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) | |
1876 | { | |
1877 | bitmap regs_set = (bitmap) data; | |
1878 | ||
1879 | if (REG_P (x) | |
f773c2bd | 1880 | && HARD_REGISTER_P (x)) |
02b47899 | 1881 | { |
f773c2bd AS |
1882 | unsigned int regno = REGNO (x); |
1883 | bitmap_set_range (regs_set, regno, | |
1884 | hard_regno_nregs[regno][GET_MODE (x)]); | |
02b47899 KZ |
1885 | } |
1886 | } | |
1887 | ||
8dd5516b JJ |
1888 | /* Helper function for replace_read and record_store. |
1889 | Attempt to return a value stored in STORE_INFO, from READ_BEGIN | |
1890 | to one before READ_END bytes read in READ_MODE. Return NULL | |
1891 | if not successful. If REQUIRE_CST is true, return always constant. */ | |
1892 | ||
1893 | static rtx | |
ef4bddc2 | 1894 | get_stored_val (store_info_t store_info, machine_mode read_mode, |
8dd5516b JJ |
1895 | HOST_WIDE_INT read_begin, HOST_WIDE_INT read_end, |
1896 | basic_block bb, bool require_cst) | |
1897 | { | |
ef4bddc2 | 1898 | machine_mode store_mode = GET_MODE (store_info->mem); |
8dd5516b JJ |
1899 | int shift; |
1900 | int access_size; /* In bytes. */ | |
1901 | rtx read_reg; | |
1902 | ||
1903 | /* To get here the read is within the boundaries of the write so | |
1904 | shift will never be negative. Start out with the shift being in | |
1905 | bytes. */ | |
1906 | if (store_mode == BLKmode) | |
1907 | shift = 0; | |
1908 | else if (BYTES_BIG_ENDIAN) | |
1909 | shift = store_info->end - read_end; | |
1910 | else | |
1911 | shift = read_begin - store_info->begin; | |
1912 | ||
1913 | access_size = shift + GET_MODE_SIZE (read_mode); | |
1914 | ||
1915 | /* From now on it is bits. */ | |
1916 | shift *= BITS_PER_UNIT; | |
1917 | ||
1918 | if (shift) | |
1919 | read_reg = find_shift_sequence (access_size, store_info, read_mode, shift, | |
1920 | optimize_bb_for_speed_p (bb), | |
1921 | require_cst); | |
1922 | else if (store_mode == BLKmode) | |
1923 | { | |
1924 | /* The store is a memset (addr, const_val, const_size). */ | |
1925 | gcc_assert (CONST_INT_P (store_info->rhs)); | |
1926 | store_mode = int_mode_for_mode (read_mode); | |
1927 | if (store_mode == BLKmode) | |
1928 | read_reg = NULL_RTX; | |
1929 | else if (store_info->rhs == const0_rtx) | |
1930 | read_reg = extract_low_bits (read_mode, store_mode, const0_rtx); | |
1931 | else if (GET_MODE_BITSIZE (store_mode) > HOST_BITS_PER_WIDE_INT | |
1932 | || BITS_PER_UNIT >= HOST_BITS_PER_WIDE_INT) | |
1933 | read_reg = NULL_RTX; | |
1934 | else | |
1935 | { | |
1936 | unsigned HOST_WIDE_INT c | |
1937 | = INTVAL (store_info->rhs) | |
1938 | & (((HOST_WIDE_INT) 1 << BITS_PER_UNIT) - 1); | |
1939 | int shift = BITS_PER_UNIT; | |
1940 | while (shift < HOST_BITS_PER_WIDE_INT) | |
1941 | { | |
1942 | c |= (c << shift); | |
1943 | shift <<= 1; | |
1944 | } | |
6d26322f | 1945 | read_reg = gen_int_mode (c, store_mode); |
8dd5516b JJ |
1946 | read_reg = extract_low_bits (read_mode, store_mode, read_reg); |
1947 | } | |
1948 | } | |
1949 | else if (store_info->const_rhs | |
1950 | && (require_cst | |
1951 | || GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))) | |
1952 | read_reg = extract_low_bits (read_mode, store_mode, | |
1953 | copy_rtx (store_info->const_rhs)); | |
1954 | else | |
1955 | read_reg = extract_low_bits (read_mode, store_mode, | |
1956 | copy_rtx (store_info->rhs)); | |
1957 | if (require_cst && read_reg && !CONSTANT_P (read_reg)) | |
1958 | read_reg = NULL_RTX; | |
1959 | return read_reg; | |
1960 | } | |
02b47899 | 1961 | |
6fb5fa3c DB |
1962 | /* Take a sequence of: |
1963 | A <- r1 | |
1964 | ... | |
1965 | ... <- A | |
1966 | ||
b8698a0f | 1967 | and change it into |
6fb5fa3c DB |
1968 | r2 <- r1 |
1969 | A <- r1 | |
1970 | ... | |
1971 | ... <- r2 | |
1972 | ||
8660aaae EC |
1973 | or |
1974 | ||
1975 | r3 <- extract (r1) | |
1976 | r3 <- r3 >> shift | |
1977 | r2 <- extract (r3) | |
1978 | ... <- r2 | |
1979 | ||
1980 | or | |
1981 | ||
1982 | r2 <- extract (r1) | |
1983 | ... <- r2 | |
1984 | ||
1985 | Depending on the alignment and the mode of the store and | |
1986 | subsequent load. | |
1987 | ||
1988 | ||
1989 | The STORE_INFO and STORE_INSN are for the store and READ_INFO | |
6fb5fa3c DB |
1990 | and READ_INSN are for the read. Return true if the replacement |
1991 | went ok. */ | |
1992 | ||
1993 | static bool | |
b8698a0f | 1994 | replace_read (store_info_t store_info, insn_info_t store_insn, |
8dd5516b JJ |
1995 | read_info_t read_info, insn_info_t read_insn, rtx *loc, |
1996 | bitmap regs_live) | |
6fb5fa3c | 1997 | { |
ef4bddc2 RS |
1998 | machine_mode store_mode = GET_MODE (store_info->mem); |
1999 | machine_mode read_mode = GET_MODE (read_info->mem); | |
dc01c3d1 DM |
2000 | rtx_insn *insns, *this_insn; |
2001 | rtx read_reg; | |
8dd5516b | 2002 | basic_block bb; |
8660aaae | 2003 | |
6fb5fa3c DB |
2004 | if (!dbg_cnt (dse)) |
2005 | return false; | |
2006 | ||
18b526e8 RS |
2007 | /* Create a sequence of instructions to set up the read register. |
2008 | This sequence goes immediately before the store and its result | |
2009 | is read by the load. | |
2010 | ||
2011 | We need to keep this in perspective. We are replacing a read | |
8660aaae EC |
2012 | with a sequence of insns, but the read will almost certainly be |
2013 | in cache, so it is not going to be an expensive one. Thus, we | |
2014 | are not willing to do a multi insn shift or worse a subroutine | |
2015 | call to get rid of the read. */ | |
456610d3 | 2016 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
2017 | fprintf (dump_file, "trying to replace %smode load in insn %d" |
2018 | " from %smode store in insn %d\n", | |
2019 | GET_MODE_NAME (read_mode), INSN_UID (read_insn->insn), | |
2020 | GET_MODE_NAME (store_mode), INSN_UID (store_insn->insn)); | |
2021 | start_sequence (); | |
8dd5516b JJ |
2022 | bb = BLOCK_FOR_INSN (read_insn->insn); |
2023 | read_reg = get_stored_val (store_info, | |
2024 | read_mode, read_info->begin, read_info->end, | |
2025 | bb, false); | |
18b526e8 | 2026 | if (read_reg == NULL_RTX) |
8660aaae | 2027 | { |
18b526e8 | 2028 | end_sequence (); |
456610d3 | 2029 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
2030 | fprintf (dump_file, " -- could not extract bits of stored value\n"); |
2031 | return false; | |
8660aaae | 2032 | } |
18b526e8 RS |
2033 | /* Force the value into a new register so that it won't be clobbered |
2034 | between the store and the load. */ | |
2035 | read_reg = copy_to_mode_reg (read_mode, read_reg); | |
2036 | insns = get_insns (); | |
2037 | end_sequence (); | |
8660aaae | 2038 | |
02b47899 KZ |
2039 | if (insns != NULL_RTX) |
2040 | { | |
2041 | /* Now we have to scan the set of new instructions to see if the | |
2042 | sequence contains and sets of hardregs that happened to be | |
2043 | live at this point. For instance, this can happen if one of | |
2044 | the insns sets the CC and the CC happened to be live at that | |
2045 | point. This does occasionally happen, see PR 37922. */ | |
3f9b14ff | 2046 | bitmap regs_set = BITMAP_ALLOC (®_obstack); |
02b47899 KZ |
2047 | |
2048 | for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn)) | |
2049 | note_stores (PATTERN (this_insn), look_for_hardregs, regs_set); | |
b8698a0f | 2050 | |
02b47899 KZ |
2051 | bitmap_and_into (regs_set, regs_live); |
2052 | if (!bitmap_empty_p (regs_set)) | |
2053 | { | |
456610d3 | 2054 | if (dump_file && (dump_flags & TDF_DETAILS)) |
02b47899 | 2055 | { |
b8698a0f | 2056 | fprintf (dump_file, |
02b47899 KZ |
2057 | "abandoning replacement because sequence clobbers live hardregs:"); |
2058 | df_print_regset (dump_file, regs_set); | |
2059 | } | |
b8698a0f | 2060 | |
02b47899 KZ |
2061 | BITMAP_FREE (regs_set); |
2062 | return false; | |
2063 | } | |
2064 | BITMAP_FREE (regs_set); | |
2065 | } | |
2066 | ||
8660aaae | 2067 | if (validate_change (read_insn->insn, loc, read_reg, 0)) |
6fb5fa3c | 2068 | { |
f883e0a7 KG |
2069 | deferred_change_t deferred_change = |
2070 | (deferred_change_t) pool_alloc (deferred_change_pool); | |
b8698a0f | 2071 | |
8660aaae EC |
2072 | /* Insert this right before the store insn where it will be safe |
2073 | from later insns that might change it before the read. */ | |
2074 | emit_insn_before (insns, store_insn->insn); | |
b8698a0f | 2075 | |
8660aaae EC |
2076 | /* And now for the kludge part: cselib croaks if you just |
2077 | return at this point. There are two reasons for this: | |
b8698a0f | 2078 | |
8660aaae EC |
2079 | 1) Cselib has an idea of how many pseudos there are and |
2080 | that does not include the new ones we just added. | |
b8698a0f | 2081 | |
8660aaae EC |
2082 | 2) Cselib does not know about the move insn we added |
2083 | above the store_info, and there is no way to tell it | |
2084 | about it, because it has "moved on". | |
b8698a0f | 2085 | |
8660aaae EC |
2086 | Problem (1) is fixable with a certain amount of engineering. |
2087 | Problem (2) is requires starting the bb from scratch. This | |
2088 | could be expensive. | |
b8698a0f | 2089 | |
8660aaae EC |
2090 | So we are just going to have to lie. The move/extraction |
2091 | insns are not really an issue, cselib did not see them. But | |
2092 | the use of the new pseudo read_insn is a real problem because | |
2093 | cselib has not scanned this insn. The way that we solve this | |
2094 | problem is that we are just going to put the mem back for now | |
2095 | and when we are finished with the block, we undo this. We | |
2096 | keep a table of mems to get rid of. At the end of the basic | |
2097 | block we can put them back. */ | |
b8698a0f | 2098 | |
8660aaae EC |
2099 | *loc = read_info->mem; |
2100 | deferred_change->next = deferred_change_list; | |
2101 | deferred_change_list = deferred_change; | |
2102 | deferred_change->loc = loc; | |
2103 | deferred_change->reg = read_reg; | |
b8698a0f | 2104 | |
8660aaae EC |
2105 | /* Get rid of the read_info, from the point of view of the |
2106 | rest of dse, play like this read never happened. */ | |
2107 | read_insn->read_rec = read_info->next; | |
2108 | pool_free (read_info_pool, read_info); | |
456610d3 | 2109 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
2110 | { |
2111 | fprintf (dump_file, " -- replaced the loaded MEM with "); | |
2112 | print_simple_rtl (dump_file, read_reg); | |
2113 | fprintf (dump_file, "\n"); | |
2114 | } | |
8660aaae | 2115 | return true; |
6fb5fa3c | 2116 | } |
b8698a0f | 2117 | else |
6fb5fa3c | 2118 | { |
456610d3 | 2119 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
2120 | { |
2121 | fprintf (dump_file, " -- replacing the loaded MEM with "); | |
2122 | print_simple_rtl (dump_file, read_reg); | |
2123 | fprintf (dump_file, " led to an invalid instruction\n"); | |
2124 | } | |
6fb5fa3c DB |
2125 | return false; |
2126 | } | |
2127 | } | |
2128 | ||
d7111da8 RS |
2129 | /* Check the address of MEM *LOC and kill any appropriate stores that may |
2130 | be active. */ | |
6fb5fa3c | 2131 | |
d7111da8 RS |
2132 | static void |
2133 | check_mem_read_rtx (rtx *loc, bb_info_t bb_info) | |
6fb5fa3c | 2134 | { |
6216f94e | 2135 | rtx mem = *loc, mem_addr; |
6fb5fa3c DB |
2136 | insn_info_t insn_info; |
2137 | HOST_WIDE_INT offset = 0; | |
2138 | HOST_WIDE_INT width = 0; | |
4862826d | 2139 | alias_set_type spill_alias_set = 0; |
b8698a0f | 2140 | cselib_val *base = NULL; |
6fb5fa3c DB |
2141 | int group_id; |
2142 | read_info_t read_info; | |
2143 | ||
6fb5fa3c DB |
2144 | insn_info = bb_info->last_insn; |
2145 | ||
2146 | if ((MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2147 | || (MEM_VOLATILE_P (mem))) | |
2148 | { | |
456610d3 | 2149 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2150 | fprintf (dump_file, " adding wild read, volatile or barrier.\n"); |
2151 | add_wild_read (bb_info); | |
2152 | insn_info->cannot_delete = true; | |
d7111da8 | 2153 | return; |
6fb5fa3c DB |
2154 | } |
2155 | ||
2156 | /* If it is reading readonly mem, then there can be no conflict with | |
2157 | another write. */ | |
2158 | if (MEM_READONLY_P (mem)) | |
d7111da8 | 2159 | return; |
6fb5fa3c DB |
2160 | |
2161 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
2162 | { | |
456610d3 | 2163 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2164 | fprintf (dump_file, " adding wild read, canon_address failure.\n"); |
2165 | add_wild_read (bb_info); | |
d7111da8 | 2166 | return; |
6fb5fa3c DB |
2167 | } |
2168 | ||
2169 | if (GET_MODE (mem) == BLKmode) | |
2170 | width = -1; | |
2171 | else | |
2172 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
2173 | ||
f883e0a7 | 2174 | read_info = (read_info_t) pool_alloc (read_info_pool); |
6fb5fa3c DB |
2175 | read_info->group_id = group_id; |
2176 | read_info->mem = mem; | |
2177 | read_info->alias_set = spill_alias_set; | |
2178 | read_info->begin = offset; | |
2179 | read_info->end = offset + width; | |
2180 | read_info->next = insn_info->read_rec; | |
2181 | insn_info->read_rec = read_info; | |
6216f94e JJ |
2182 | /* For alias_set != 0 canon_true_dependence should be never called. */ |
2183 | if (spill_alias_set) | |
2184 | mem_addr = NULL_RTX; | |
2185 | else | |
2186 | { | |
2187 | if (group_id < 0) | |
2188 | mem_addr = base->val_rtx; | |
2189 | else | |
2190 | { | |
2191 | group_info_t group | |
9771b263 | 2192 | = rtx_group_vec[group_id]; |
6216f94e JJ |
2193 | mem_addr = group->canon_base_addr; |
2194 | } | |
ff1803c1 WM |
2195 | /* get_addr can only handle VALUE but cannot handle expr like: |
2196 | VALUE + OFFSET, so call get_addr to get original addr for | |
2197 | mem_addr before plus_constant. */ | |
2198 | mem_addr = get_addr (mem_addr); | |
6216f94e | 2199 | if (offset) |
372d6395 | 2200 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
6216f94e | 2201 | } |
6fb5fa3c | 2202 | |
0d52bcc1 | 2203 | /* We ignore the clobbers in store_info. The is mildly aggressive, |
6fb5fa3c DB |
2204 | but there really should not be a clobber followed by a read. */ |
2205 | ||
2206 | if (spill_alias_set) | |
2207 | { | |
2208 | insn_info_t i_ptr = active_local_stores; | |
2209 | insn_info_t last = NULL; | |
2210 | ||
456610d3 | 2211 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2212 | fprintf (dump_file, " processing spill load %d\n", |
4862826d | 2213 | (int) spill_alias_set); |
6fb5fa3c DB |
2214 | |
2215 | while (i_ptr) | |
2216 | { | |
2217 | store_info_t store_info = i_ptr->store_rec; | |
2218 | ||
2219 | /* Skip the clobbers. */ | |
2220 | while (!store_info->is_set) | |
2221 | store_info = store_info->next; | |
b8698a0f | 2222 | |
6fb5fa3c DB |
2223 | if (store_info->alias_set == spill_alias_set) |
2224 | { | |
456610d3 | 2225 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2226 | dump_insn_info ("removing from active", i_ptr); |
2227 | ||
dabd47e7 | 2228 | active_local_stores_len--; |
6fb5fa3c DB |
2229 | if (last) |
2230 | last->next_local_store = i_ptr->next_local_store; | |
2231 | else | |
2232 | active_local_stores = i_ptr->next_local_store; | |
2233 | } | |
2234 | else | |
2235 | last = i_ptr; | |
2236 | i_ptr = i_ptr->next_local_store; | |
2237 | } | |
2238 | } | |
2239 | else if (group_id >= 0) | |
2240 | { | |
2241 | /* This is the restricted case where the base is a constant or | |
2242 | the frame pointer and offset is a constant. */ | |
2243 | insn_info_t i_ptr = active_local_stores; | |
2244 | insn_info_t last = NULL; | |
b8698a0f | 2245 | |
456610d3 | 2246 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2247 | { |
2248 | if (width == -1) | |
2249 | fprintf (dump_file, " processing const load gid=%d[BLK]\n", | |
2250 | group_id); | |
2251 | else | |
2252 | fprintf (dump_file, " processing const load gid=%d[%d..%d)\n", | |
2253 | group_id, (int)offset, (int)(offset+width)); | |
2254 | } | |
2255 | ||
2256 | while (i_ptr) | |
2257 | { | |
2258 | bool remove = false; | |
2259 | store_info_t store_info = i_ptr->store_rec; | |
b8698a0f | 2260 | |
6fb5fa3c DB |
2261 | /* Skip the clobbers. */ |
2262 | while (!store_info->is_set) | |
2263 | store_info = store_info->next; | |
b8698a0f | 2264 | |
6fb5fa3c DB |
2265 | /* There are three cases here. */ |
2266 | if (store_info->group_id < 0) | |
2267 | /* We have a cselib store followed by a read from a | |
2268 | const base. */ | |
b8698a0f L |
2269 | remove |
2270 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2271 | GET_MODE (store_info->mem), |
2272 | store_info->mem_addr, | |
53d9622b | 2273 | mem, mem_addr); |
b8698a0f | 2274 | |
6fb5fa3c DB |
2275 | else if (group_id == store_info->group_id) |
2276 | { | |
2277 | /* This is a block mode load. We may get lucky and | |
2278 | canon_true_dependence may save the day. */ | |
2279 | if (width == -1) | |
b8698a0f L |
2280 | remove |
2281 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2282 | GET_MODE (store_info->mem), |
2283 | store_info->mem_addr, | |
53d9622b | 2284 | mem, mem_addr); |
b8698a0f | 2285 | |
6fb5fa3c DB |
2286 | /* If this read is just reading back something that we just |
2287 | stored, rewrite the read. */ | |
b8698a0f | 2288 | else |
6fb5fa3c DB |
2289 | { |
2290 | if (store_info->rhs | |
8dd5516b JJ |
2291 | && offset >= store_info->begin |
2292 | && offset + width <= store_info->end | |
2293 | && all_positions_needed_p (store_info, | |
2294 | offset - store_info->begin, | |
2295 | width) | |
2296 | && replace_read (store_info, i_ptr, read_info, | |
2297 | insn_info, loc, bb_info->regs_live)) | |
d7111da8 | 2298 | return; |
8dd5516b | 2299 | |
6fb5fa3c DB |
2300 | /* The bases are the same, just see if the offsets |
2301 | overlap. */ | |
b8698a0f | 2302 | if ((offset < store_info->end) |
6fb5fa3c DB |
2303 | && (offset + width > store_info->begin)) |
2304 | remove = true; | |
2305 | } | |
2306 | } | |
b8698a0f L |
2307 | |
2308 | /* else | |
6fb5fa3c DB |
2309 | The else case that is missing here is that the |
2310 | bases are constant but different. There is nothing | |
2311 | to do here because there is no overlap. */ | |
b8698a0f | 2312 | |
6fb5fa3c DB |
2313 | if (remove) |
2314 | { | |
456610d3 | 2315 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2316 | dump_insn_info ("removing from active", i_ptr); |
2317 | ||
dabd47e7 | 2318 | active_local_stores_len--; |
6fb5fa3c DB |
2319 | if (last) |
2320 | last->next_local_store = i_ptr->next_local_store; | |
2321 | else | |
2322 | active_local_stores = i_ptr->next_local_store; | |
2323 | } | |
2324 | else | |
2325 | last = i_ptr; | |
2326 | i_ptr = i_ptr->next_local_store; | |
2327 | } | |
2328 | } | |
b8698a0f | 2329 | else |
6fb5fa3c DB |
2330 | { |
2331 | insn_info_t i_ptr = active_local_stores; | |
2332 | insn_info_t last = NULL; | |
456610d3 | 2333 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2334 | { |
2335 | fprintf (dump_file, " processing cselib load mem:"); | |
2336 | print_inline_rtx (dump_file, mem, 0); | |
2337 | fprintf (dump_file, "\n"); | |
2338 | } | |
2339 | ||
2340 | while (i_ptr) | |
2341 | { | |
2342 | bool remove = false; | |
2343 | store_info_t store_info = i_ptr->store_rec; | |
b8698a0f | 2344 | |
456610d3 | 2345 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2346 | fprintf (dump_file, " processing cselib load against insn %d\n", |
2347 | INSN_UID (i_ptr->insn)); | |
2348 | ||
2349 | /* Skip the clobbers. */ | |
2350 | while (!store_info->is_set) | |
2351 | store_info = store_info->next; | |
2352 | ||
2353 | /* If this read is just reading back something that we just | |
2354 | stored, rewrite the read. */ | |
2355 | if (store_info->rhs | |
2356 | && store_info->group_id == -1 | |
2357 | && store_info->cse_base == base | |
efc3527a | 2358 | && width != -1 |
8dd5516b JJ |
2359 | && offset >= store_info->begin |
2360 | && offset + width <= store_info->end | |
2361 | && all_positions_needed_p (store_info, | |
2362 | offset - store_info->begin, width) | |
2363 | && replace_read (store_info, i_ptr, read_info, insn_info, loc, | |
2364 | bb_info->regs_live)) | |
d7111da8 | 2365 | return; |
6fb5fa3c DB |
2366 | |
2367 | if (!store_info->alias_set) | |
b8698a0f | 2368 | remove = canon_true_dependence (store_info->mem, |
6fb5fa3c DB |
2369 | GET_MODE (store_info->mem), |
2370 | store_info->mem_addr, | |
53d9622b | 2371 | mem, mem_addr); |
b8698a0f | 2372 | |
6fb5fa3c DB |
2373 | if (remove) |
2374 | { | |
456610d3 | 2375 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2376 | dump_insn_info ("removing from active", i_ptr); |
b8698a0f | 2377 | |
dabd47e7 | 2378 | active_local_stores_len--; |
6fb5fa3c DB |
2379 | if (last) |
2380 | last->next_local_store = i_ptr->next_local_store; | |
2381 | else | |
2382 | active_local_stores = i_ptr->next_local_store; | |
2383 | } | |
2384 | else | |
2385 | last = i_ptr; | |
2386 | i_ptr = i_ptr->next_local_store; | |
2387 | } | |
2388 | } | |
6fb5fa3c DB |
2389 | } |
2390 | ||
d7111da8 | 2391 | /* A note_uses callback in which DATA points the INSN_INFO for |
6fb5fa3c DB |
2392 | as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns |
2393 | true for any part of *LOC. */ | |
2394 | ||
2395 | static void | |
2396 | check_mem_read_use (rtx *loc, void *data) | |
2397 | { | |
d7111da8 RS |
2398 | subrtx_ptr_iterator::array_type array; |
2399 | FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST) | |
2400 | { | |
2401 | rtx *loc = *iter; | |
2402 | if (MEM_P (*loc)) | |
2403 | check_mem_read_rtx (loc, (bb_info_t) data); | |
2404 | } | |
6fb5fa3c DB |
2405 | } |
2406 | ||
8dd5516b JJ |
2407 | |
2408 | /* Get arguments passed to CALL_INSN. Return TRUE if successful. | |
2409 | So far it only handles arguments passed in registers. */ | |
2410 | ||
2411 | static bool | |
2412 | get_call_args (rtx call_insn, tree fn, rtx *args, int nargs) | |
2413 | { | |
d5cc9181 JR |
2414 | CUMULATIVE_ARGS args_so_far_v; |
2415 | cumulative_args_t args_so_far; | |
8dd5516b JJ |
2416 | tree arg; |
2417 | int idx; | |
2418 | ||
d5cc9181 JR |
2419 | INIT_CUMULATIVE_ARGS (args_so_far_v, TREE_TYPE (fn), NULL_RTX, 0, 3); |
2420 | args_so_far = pack_cumulative_args (&args_so_far_v); | |
8dd5516b JJ |
2421 | |
2422 | arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2423 | for (idx = 0; | |
2424 | arg != void_list_node && idx < nargs; | |
2425 | arg = TREE_CHAIN (arg), idx++) | |
2426 | { | |
ef4bddc2 | 2427 | machine_mode mode = TYPE_MODE (TREE_VALUE (arg)); |
3c07301f | 2428 | rtx reg, link, tmp; |
d5cc9181 | 2429 | reg = targetm.calls.function_arg (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2430 | if (!reg || !REG_P (reg) || GET_MODE (reg) != mode |
2431 | || GET_MODE_CLASS (mode) != MODE_INT) | |
2432 | return false; | |
2433 | ||
2434 | for (link = CALL_INSN_FUNCTION_USAGE (call_insn); | |
2435 | link; | |
2436 | link = XEXP (link, 1)) | |
2437 | if (GET_CODE (XEXP (link, 0)) == USE) | |
2438 | { | |
2439 | args[idx] = XEXP (XEXP (link, 0), 0); | |
2440 | if (REG_P (args[idx]) | |
2441 | && REGNO (args[idx]) == REGNO (reg) | |
2442 | && (GET_MODE (args[idx]) == mode | |
2443 | || (GET_MODE_CLASS (GET_MODE (args[idx])) == MODE_INT | |
2444 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2445 | <= UNITS_PER_WORD) | |
2446 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2447 | > GET_MODE_SIZE (mode))))) | |
2448 | break; | |
2449 | } | |
2450 | if (!link) | |
2451 | return false; | |
2452 | ||
2453 | tmp = cselib_expand_value_rtx (args[idx], scratch, 5); | |
2454 | if (GET_MODE (args[idx]) != mode) | |
2455 | { | |
2456 | if (!tmp || !CONST_INT_P (tmp)) | |
2457 | return false; | |
6d26322f | 2458 | tmp = gen_int_mode (INTVAL (tmp), mode); |
8dd5516b JJ |
2459 | } |
2460 | if (tmp) | |
2461 | args[idx] = tmp; | |
2462 | ||
d5cc9181 | 2463 | targetm.calls.function_arg_advance (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2464 | } |
2465 | if (arg != void_list_node || idx != nargs) | |
2466 | return false; | |
2467 | return true; | |
2468 | } | |
2469 | ||
9e582b1d JR |
2470 | /* Return a bitmap of the fixed registers contained in IN. */ |
2471 | ||
2472 | static bitmap | |
2473 | copy_fixed_regs (const_bitmap in) | |
2474 | { | |
2475 | bitmap ret; | |
2476 | ||
2477 | ret = ALLOC_REG_SET (NULL); | |
2478 | bitmap_and (ret, in, fixed_reg_set_regset); | |
2479 | return ret; | |
2480 | } | |
8dd5516b | 2481 | |
6fb5fa3c DB |
2482 | /* Apply record_store to all candidate stores in INSN. Mark INSN |
2483 | if some part of it is not a candidate store and assigns to a | |
2484 | non-register target. */ | |
2485 | ||
2486 | static void | |
dd60a84c | 2487 | scan_insn (bb_info_t bb_info, rtx_insn *insn) |
6fb5fa3c DB |
2488 | { |
2489 | rtx body; | |
f883e0a7 | 2490 | insn_info_t insn_info = (insn_info_t) pool_alloc (insn_info_pool); |
6fb5fa3c DB |
2491 | int mems_found = 0; |
2492 | memset (insn_info, 0, sizeof (struct insn_info)); | |
2493 | ||
456610d3 | 2494 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2495 | fprintf (dump_file, "\n**scanning insn=%d\n", |
2496 | INSN_UID (insn)); | |
2497 | ||
2498 | insn_info->prev_insn = bb_info->last_insn; | |
2499 | insn_info->insn = insn; | |
2500 | bb_info->last_insn = insn_info; | |
b8698a0f | 2501 | |
b5b8b0ac AO |
2502 | if (DEBUG_INSN_P (insn)) |
2503 | { | |
2504 | insn_info->cannot_delete = true; | |
2505 | return; | |
2506 | } | |
6fb5fa3c | 2507 | |
6fb5fa3c DB |
2508 | /* Look at all of the uses in the insn. */ |
2509 | note_uses (&PATTERN (insn), check_mem_read_use, bb_info); | |
2510 | ||
2511 | if (CALL_P (insn)) | |
2512 | { | |
8dd5516b JJ |
2513 | bool const_call; |
2514 | tree memset_call = NULL_TREE; | |
2515 | ||
6fb5fa3c | 2516 | insn_info->cannot_delete = true; |
50f0f366 | 2517 | |
6fb5fa3c | 2518 | /* Const functions cannot do anything bad i.e. read memory, |
50f0f366 | 2519 | however, they can read their parameters which may have |
8dd5516b JJ |
2520 | been pushed onto the stack. |
2521 | memset and bzero don't read memory either. */ | |
2522 | const_call = RTL_CONST_CALL_P (insn); | |
2523 | if (!const_call) | |
2524 | { | |
da4fdf2d SB |
2525 | rtx call = get_call_rtx_from (insn); |
2526 | if (call && GET_CODE (XEXP (XEXP (call, 0), 0)) == SYMBOL_REF) | |
8dd5516b JJ |
2527 | { |
2528 | rtx symbol = XEXP (XEXP (call, 0), 0); | |
2529 | if (SYMBOL_REF_DECL (symbol) | |
2530 | && TREE_CODE (SYMBOL_REF_DECL (symbol)) == FUNCTION_DECL) | |
2531 | { | |
2532 | if ((DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (symbol)) | |
2533 | == BUILT_IN_NORMAL | |
2534 | && (DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol)) | |
2535 | == BUILT_IN_MEMSET)) | |
2536 | || SYMBOL_REF_DECL (symbol) == block_clear_fn) | |
2537 | memset_call = SYMBOL_REF_DECL (symbol); | |
2538 | } | |
2539 | } | |
2540 | } | |
2541 | if (const_call || memset_call) | |
6fb5fa3c DB |
2542 | { |
2543 | insn_info_t i_ptr = active_local_stores; | |
2544 | insn_info_t last = NULL; | |
2545 | ||
456610d3 | 2546 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2547 | fprintf (dump_file, "%s call %d\n", |
2548 | const_call ? "const" : "memset", INSN_UID (insn)); | |
6fb5fa3c | 2549 | |
64520bdc | 2550 | /* See the head comment of the frame_read field. */ |
57534689 JJ |
2551 | if (reload_completed |
2552 | /* Tail calls are storing their arguments using | |
2553 | arg pointer. If it is a frame pointer on the target, | |
2554 | even before reload we need to kill frame pointer based | |
2555 | stores. */ | |
2556 | || (SIBLING_CALL_P (insn) | |
2557 | && HARD_FRAME_POINTER_IS_ARG_POINTER)) | |
64520bdc EB |
2558 | insn_info->frame_read = true; |
2559 | ||
2560 | /* Loop over the active stores and remove those which are | |
2561 | killed by the const function call. */ | |
6fb5fa3c DB |
2562 | while (i_ptr) |
2563 | { | |
64520bdc EB |
2564 | bool remove_store = false; |
2565 | ||
2566 | /* The stack pointer based stores are always killed. */ | |
50f0f366 | 2567 | if (i_ptr->stack_pointer_based) |
64520bdc EB |
2568 | remove_store = true; |
2569 | ||
2570 | /* If the frame is read, the frame related stores are killed. */ | |
2571 | else if (insn_info->frame_read) | |
2572 | { | |
2573 | store_info_t store_info = i_ptr->store_rec; | |
2574 | ||
2575 | /* Skip the clobbers. */ | |
2576 | while (!store_info->is_set) | |
2577 | store_info = store_info->next; | |
2578 | ||
2579 | if (store_info->group_id >= 0 | |
9771b263 | 2580 | && rtx_group_vec[store_info->group_id]->frame_related) |
64520bdc EB |
2581 | remove_store = true; |
2582 | } | |
2583 | ||
2584 | if (remove_store) | |
6fb5fa3c | 2585 | { |
456610d3 | 2586 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2587 | dump_insn_info ("removing from active", i_ptr); |
b8698a0f | 2588 | |
dabd47e7 | 2589 | active_local_stores_len--; |
6fb5fa3c DB |
2590 | if (last) |
2591 | last->next_local_store = i_ptr->next_local_store; | |
2592 | else | |
2593 | active_local_stores = i_ptr->next_local_store; | |
2594 | } | |
2595 | else | |
2596 | last = i_ptr; | |
64520bdc | 2597 | |
6fb5fa3c DB |
2598 | i_ptr = i_ptr->next_local_store; |
2599 | } | |
8dd5516b JJ |
2600 | |
2601 | if (memset_call) | |
2602 | { | |
2603 | rtx args[3]; | |
2604 | if (get_call_args (insn, memset_call, args, 3) | |
2605 | && CONST_INT_P (args[1]) | |
2606 | && CONST_INT_P (args[2]) | |
2607 | && INTVAL (args[2]) > 0) | |
2608 | { | |
2609 | rtx mem = gen_rtx_MEM (BLKmode, args[0]); | |
f5541398 | 2610 | set_mem_size (mem, INTVAL (args[2])); |
f7df4a84 | 2611 | body = gen_rtx_SET (mem, args[1]); |
8dd5516b | 2612 | mems_found += record_store (body, bb_info); |
456610d3 | 2613 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2614 | fprintf (dump_file, "handling memset as BLKmode store\n"); |
2615 | if (mems_found == 1) | |
2616 | { | |
dabd47e7 JJ |
2617 | if (active_local_stores_len++ |
2618 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2619 | { | |
2620 | active_local_stores_len = 1; | |
2621 | active_local_stores = NULL; | |
2622 | } | |
9e582b1d JR |
2623 | insn_info->fixed_regs_live |
2624 | = copy_fixed_regs (bb_info->regs_live); | |
8dd5516b JJ |
2625 | insn_info->next_local_store = active_local_stores; |
2626 | active_local_stores = insn_info; | |
2627 | } | |
2628 | } | |
2629 | } | |
6fb5fa3c | 2630 | } |
57534689 JJ |
2631 | else if (SIBLING_CALL_P (insn) && reload_completed) |
2632 | /* Arguments for a sibling call that are pushed to memory are passed | |
2633 | using the incoming argument pointer of the current function. After | |
2634 | reload that might be (and likely is) frame pointer based. */ | |
2635 | add_wild_read (bb_info); | |
50f0f366 | 2636 | else |
d26c7090 ER |
2637 | /* Every other call, including pure functions, may read any memory |
2638 | that is not relative to the frame. */ | |
2639 | add_non_frame_wild_read (bb_info); | |
50f0f366 | 2640 | |
6fb5fa3c DB |
2641 | return; |
2642 | } | |
2643 | ||
2644 | /* Assuming that there are sets in these insns, we cannot delete | |
2645 | them. */ | |
2646 | if ((GET_CODE (PATTERN (insn)) == CLOBBER) | |
0a64eeca | 2647 | || volatile_refs_p (PATTERN (insn)) |
2da02156 | 2648 | || (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) |
6fb5fa3c DB |
2649 | || (RTX_FRAME_RELATED_P (insn)) |
2650 | || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX)) | |
2651 | insn_info->cannot_delete = true; | |
b8698a0f | 2652 | |
6fb5fa3c DB |
2653 | body = PATTERN (insn); |
2654 | if (GET_CODE (body) == PARALLEL) | |
2655 | { | |
2656 | int i; | |
2657 | for (i = 0; i < XVECLEN (body, 0); i++) | |
2658 | mems_found += record_store (XVECEXP (body, 0, i), bb_info); | |
2659 | } | |
2660 | else | |
2661 | mems_found += record_store (body, bb_info); | |
2662 | ||
456610d3 | 2663 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 2664 | fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n", |
6fb5fa3c DB |
2665 | mems_found, insn_info->cannot_delete ? "true" : "false"); |
2666 | ||
8dd5516b JJ |
2667 | /* If we found some sets of mems, add it into the active_local_stores so |
2668 | that it can be locally deleted if found dead or used for | |
2669 | replace_read and redundant constant store elimination. Otherwise mark | |
2670 | it as cannot delete. This simplifies the processing later. */ | |
2671 | if (mems_found == 1) | |
6fb5fa3c | 2672 | { |
dabd47e7 JJ |
2673 | if (active_local_stores_len++ |
2674 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2675 | { | |
2676 | active_local_stores_len = 1; | |
2677 | active_local_stores = NULL; | |
2678 | } | |
9e582b1d | 2679 | insn_info->fixed_regs_live = copy_fixed_regs (bb_info->regs_live); |
6fb5fa3c DB |
2680 | insn_info->next_local_store = active_local_stores; |
2681 | active_local_stores = insn_info; | |
2682 | } | |
2683 | else | |
2684 | insn_info->cannot_delete = true; | |
2685 | } | |
2686 | ||
2687 | ||
2688 | /* Remove BASE from the set of active_local_stores. This is a | |
2689 | callback from cselib that is used to get rid of the stores in | |
2690 | active_local_stores. */ | |
2691 | ||
2692 | static void | |
2693 | remove_useless_values (cselib_val *base) | |
2694 | { | |
2695 | insn_info_t insn_info = active_local_stores; | |
2696 | insn_info_t last = NULL; | |
2697 | ||
2698 | while (insn_info) | |
2699 | { | |
2700 | store_info_t store_info = insn_info->store_rec; | |
60564289 | 2701 | bool del = false; |
6fb5fa3c DB |
2702 | |
2703 | /* If ANY of the store_infos match the cselib group that is | |
2704 | being deleted, then the insn can not be deleted. */ | |
2705 | while (store_info) | |
2706 | { | |
b8698a0f | 2707 | if ((store_info->group_id == -1) |
6fb5fa3c DB |
2708 | && (store_info->cse_base == base)) |
2709 | { | |
60564289 | 2710 | del = true; |
6fb5fa3c DB |
2711 | break; |
2712 | } | |
2713 | store_info = store_info->next; | |
2714 | } | |
2715 | ||
60564289 | 2716 | if (del) |
6fb5fa3c | 2717 | { |
dabd47e7 | 2718 | active_local_stores_len--; |
6fb5fa3c DB |
2719 | if (last) |
2720 | last->next_local_store = insn_info->next_local_store; | |
2721 | else | |
2722 | active_local_stores = insn_info->next_local_store; | |
2723 | free_store_info (insn_info); | |
2724 | } | |
2725 | else | |
2726 | last = insn_info; | |
b8698a0f | 2727 | |
6fb5fa3c DB |
2728 | insn_info = insn_info->next_local_store; |
2729 | } | |
2730 | } | |
2731 | ||
2732 | ||
2733 | /* Do all of step 1. */ | |
2734 | ||
2735 | static void | |
2736 | dse_step1 (void) | |
2737 | { | |
2738 | basic_block bb; | |
3f9b14ff | 2739 | bitmap regs_live = BITMAP_ALLOC (®_obstack); |
b8698a0f | 2740 | |
457eeaae | 2741 | cselib_init (0); |
6fb5fa3c DB |
2742 | all_blocks = BITMAP_ALLOC (NULL); |
2743 | bitmap_set_bit (all_blocks, ENTRY_BLOCK); | |
2744 | bitmap_set_bit (all_blocks, EXIT_BLOCK); | |
2745 | ||
04a90bec | 2746 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
2747 | { |
2748 | insn_info_t ptr; | |
f883e0a7 | 2749 | bb_info_t bb_info = (bb_info_t) pool_alloc (bb_info_pool); |
6fb5fa3c | 2750 | |
11478306 | 2751 | memset (bb_info, 0, sizeof (struct dse_bb_info)); |
6fb5fa3c | 2752 | bitmap_set_bit (all_blocks, bb->index); |
02b47899 KZ |
2753 | bb_info->regs_live = regs_live; |
2754 | ||
2755 | bitmap_copy (regs_live, DF_LR_IN (bb)); | |
2756 | df_simulate_initialize_forwards (bb, regs_live); | |
6fb5fa3c DB |
2757 | |
2758 | bb_table[bb->index] = bb_info; | |
2759 | cselib_discard_hook = remove_useless_values; | |
2760 | ||
2761 | if (bb->index >= NUM_FIXED_BLOCKS) | |
2762 | { | |
dd60a84c | 2763 | rtx_insn *insn; |
6fb5fa3c DB |
2764 | |
2765 | cse_store_info_pool | |
b8698a0f | 2766 | = create_alloc_pool ("cse_store_info_pool", |
6fb5fa3c DB |
2767 | sizeof (struct store_info), 100); |
2768 | active_local_stores = NULL; | |
dabd47e7 | 2769 | active_local_stores_len = 0; |
6fb5fa3c | 2770 | cselib_clear_table (); |
b8698a0f | 2771 | |
6fb5fa3c DB |
2772 | /* Scan the insns. */ |
2773 | FOR_BB_INSNS (bb, insn) | |
2774 | { | |
2775 | if (INSN_P (insn)) | |
2776 | scan_insn (bb_info, insn); | |
2777 | cselib_process_insn (insn); | |
02b47899 KZ |
2778 | if (INSN_P (insn)) |
2779 | df_simulate_one_insn_forwards (bb, insn, regs_live); | |
6fb5fa3c | 2780 | } |
b8698a0f | 2781 | |
6fb5fa3c DB |
2782 | /* This is something of a hack, because the global algorithm |
2783 | is supposed to take care of the case where stores go dead | |
2784 | at the end of the function. However, the global | |
2785 | algorithm must take a more conservative view of block | |
2786 | mode reads than the local alg does. So to get the case | |
2787 | where you have a store to the frame followed by a non | |
0d52bcc1 | 2788 | overlapping block more read, we look at the active local |
6fb5fa3c DB |
2789 | stores at the end of the function and delete all of the |
2790 | frame and spill based ones. */ | |
2791 | if (stores_off_frame_dead_at_return | |
2792 | && (EDGE_COUNT (bb->succs) == 0 | |
2793 | || (single_succ_p (bb) | |
fefa31b5 | 2794 | && single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (cfun) |
e3b5732b | 2795 | && ! crtl->calls_eh_return))) |
6fb5fa3c DB |
2796 | { |
2797 | insn_info_t i_ptr = active_local_stores; | |
2798 | while (i_ptr) | |
2799 | { | |
2800 | store_info_t store_info = i_ptr->store_rec; | |
2801 | ||
2802 | /* Skip the clobbers. */ | |
2803 | while (!store_info->is_set) | |
2804 | store_info = store_info->next; | |
8dd5516b | 2805 | if (store_info->alias_set && !i_ptr->cannot_delete) |
6fb5fa3c | 2806 | delete_dead_store_insn (i_ptr); |
b8698a0f | 2807 | else |
6fb5fa3c DB |
2808 | if (store_info->group_id >= 0) |
2809 | { | |
b8698a0f | 2810 | group_info_t group |
9771b263 | 2811 | = rtx_group_vec[store_info->group_id]; |
8dd5516b | 2812 | if (group->frame_related && !i_ptr->cannot_delete) |
6fb5fa3c DB |
2813 | delete_dead_store_insn (i_ptr); |
2814 | } | |
2815 | ||
2816 | i_ptr = i_ptr->next_local_store; | |
2817 | } | |
2818 | } | |
2819 | ||
2820 | /* Get rid of the loads that were discovered in | |
2821 | replace_read. Cselib is finished with this block. */ | |
2822 | while (deferred_change_list) | |
2823 | { | |
2824 | deferred_change_t next = deferred_change_list->next; | |
2825 | ||
2826 | /* There is no reason to validate this change. That was | |
2827 | done earlier. */ | |
2828 | *deferred_change_list->loc = deferred_change_list->reg; | |
2829 | pool_free (deferred_change_pool, deferred_change_list); | |
2830 | deferred_change_list = next; | |
2831 | } | |
2832 | ||
2833 | /* Get rid of all of the cselib based store_infos in this | |
2834 | block and mark the containing insns as not being | |
2835 | deletable. */ | |
2836 | ptr = bb_info->last_insn; | |
2837 | while (ptr) | |
2838 | { | |
2839 | if (ptr->contains_cselib_groups) | |
8dd5516b JJ |
2840 | { |
2841 | store_info_t s_info = ptr->store_rec; | |
2842 | while (s_info && !s_info->is_set) | |
2843 | s_info = s_info->next; | |
2844 | if (s_info | |
2845 | && s_info->redundant_reason | |
2846 | && s_info->redundant_reason->insn | |
2847 | && !ptr->cannot_delete) | |
2848 | { | |
456610d3 | 2849 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2850 | fprintf (dump_file, "Locally deleting insn %d " |
2851 | "because insn %d stores the " | |
2852 | "same value and couldn't be " | |
2853 | "eliminated\n", | |
2854 | INSN_UID (ptr->insn), | |
2855 | INSN_UID (s_info->redundant_reason->insn)); | |
2856 | delete_dead_store_insn (ptr); | |
2857 | } | |
8dd5516b JJ |
2858 | free_store_info (ptr); |
2859 | } | |
2860 | else | |
2861 | { | |
2862 | store_info_t s_info; | |
2863 | ||
2864 | /* Free at least positions_needed bitmaps. */ | |
2865 | for (s_info = ptr->store_rec; s_info; s_info = s_info->next) | |
2866 | if (s_info->is_large) | |
2867 | { | |
dc491a25 | 2868 | BITMAP_FREE (s_info->positions_needed.large.bmap); |
8dd5516b JJ |
2869 | s_info->is_large = false; |
2870 | } | |
2871 | } | |
6fb5fa3c DB |
2872 | ptr = ptr->prev_insn; |
2873 | } | |
2874 | ||
2875 | free_alloc_pool (cse_store_info_pool); | |
2876 | } | |
02b47899 | 2877 | bb_info->regs_live = NULL; |
6fb5fa3c DB |
2878 | } |
2879 | ||
02b47899 | 2880 | BITMAP_FREE (regs_live); |
6fb5fa3c | 2881 | cselib_finish (); |
c203e8a7 | 2882 | rtx_group_table->empty (); |
6fb5fa3c DB |
2883 | } |
2884 | ||
2885 | \f | |
2886 | /*---------------------------------------------------------------------------- | |
2887 | Second step. | |
2888 | ||
2889 | Assign each byte position in the stores that we are going to | |
2890 | analyze globally to a position in the bitmaps. Returns true if | |
6ed3da00 | 2891 | there are any bit positions assigned. |
6fb5fa3c DB |
2892 | ----------------------------------------------------------------------------*/ |
2893 | ||
2894 | static void | |
2895 | dse_step2_init (void) | |
2896 | { | |
2897 | unsigned int i; | |
2898 | group_info_t group; | |
2899 | ||
9771b263 | 2900 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2901 | { |
2902 | /* For all non stack related bases, we only consider a store to | |
2903 | be deletable if there are two or more stores for that | |
2904 | position. This is because it takes one store to make the | |
2905 | other store redundant. However, for the stores that are | |
2906 | stack related, we consider them if there is only one store | |
2907 | for the position. We do this because the stack related | |
2908 | stores can be deleted if their is no read between them and | |
2909 | the end of the function. | |
b8698a0f | 2910 | |
6fb5fa3c DB |
2911 | To make this work in the current framework, we take the stack |
2912 | related bases add all of the bits from store1 into store2. | |
2913 | This has the effect of making the eligible even if there is | |
2914 | only one store. */ | |
2915 | ||
2916 | if (stores_off_frame_dead_at_return && group->frame_related) | |
2917 | { | |
2918 | bitmap_ior_into (group->store2_n, group->store1_n); | |
2919 | bitmap_ior_into (group->store2_p, group->store1_p); | |
456610d3 | 2920 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 2921 | fprintf (dump_file, "group %d is frame related ", i); |
6fb5fa3c DB |
2922 | } |
2923 | ||
2924 | group->offset_map_size_n++; | |
3f9b14ff SB |
2925 | group->offset_map_n = XOBNEWVEC (&dse_obstack, int, |
2926 | group->offset_map_size_n); | |
6fb5fa3c | 2927 | group->offset_map_size_p++; |
3f9b14ff SB |
2928 | group->offset_map_p = XOBNEWVEC (&dse_obstack, int, |
2929 | group->offset_map_size_p); | |
6fb5fa3c | 2930 | group->process_globally = false; |
456610d3 | 2931 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2932 | { |
b8698a0f | 2933 | fprintf (dump_file, "group %d(%d+%d): ", i, |
6fb5fa3c DB |
2934 | (int)bitmap_count_bits (group->store2_n), |
2935 | (int)bitmap_count_bits (group->store2_p)); | |
2936 | bitmap_print (dump_file, group->store2_n, "n ", " "); | |
2937 | bitmap_print (dump_file, group->store2_p, "p ", "\n"); | |
2938 | } | |
2939 | } | |
2940 | } | |
2941 | ||
2942 | ||
2943 | /* Init the offset tables for the normal case. */ | |
2944 | ||
2945 | static bool | |
2946 | dse_step2_nospill (void) | |
2947 | { | |
2948 | unsigned int i; | |
2949 | group_info_t group; | |
2950 | /* Position 0 is unused because 0 is used in the maps to mean | |
2951 | unused. */ | |
2952 | current_position = 1; | |
9771b263 | 2953 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2954 | { |
2955 | bitmap_iterator bi; | |
2956 | unsigned int j; | |
2957 | ||
2958 | if (group == clear_alias_group) | |
2959 | continue; | |
2960 | ||
c3284718 RS |
2961 | memset (group->offset_map_n, 0, sizeof (int) * group->offset_map_size_n); |
2962 | memset (group->offset_map_p, 0, sizeof (int) * group->offset_map_size_p); | |
6fb5fa3c DB |
2963 | bitmap_clear (group->group_kill); |
2964 | ||
2965 | EXECUTE_IF_SET_IN_BITMAP (group->store2_n, 0, j, bi) | |
2966 | { | |
2967 | bitmap_set_bit (group->group_kill, current_position); | |
d26c7090 ER |
2968 | if (bitmap_bit_p (group->escaped_n, j)) |
2969 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2970 | group->offset_map_n[j] = current_position++; |
2971 | group->process_globally = true; | |
2972 | } | |
2973 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2974 | { | |
b8698a0f | 2975 | bitmap_set_bit (group->group_kill, current_position); |
d26c7090 ER |
2976 | if (bitmap_bit_p (group->escaped_p, j)) |
2977 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2978 | group->offset_map_p[j] = current_position++; |
2979 | group->process_globally = true; | |
2980 | } | |
2981 | } | |
2982 | return current_position != 1; | |
2983 | } | |
2984 | ||
2985 | ||
6fb5fa3c DB |
2986 | \f |
2987 | /*---------------------------------------------------------------------------- | |
2988 | Third step. | |
b8698a0f | 2989 | |
6fb5fa3c DB |
2990 | Build the bit vectors for the transfer functions. |
2991 | ----------------------------------------------------------------------------*/ | |
2992 | ||
2993 | ||
6fb5fa3c DB |
2994 | /* Look up the bitmap index for OFFSET in GROUP_INFO. If it is not |
2995 | there, return 0. */ | |
2996 | ||
2997 | static int | |
2998 | get_bitmap_index (group_info_t group_info, HOST_WIDE_INT offset) | |
2999 | { | |
3000 | if (offset < 0) | |
3001 | { | |
3002 | HOST_WIDE_INT offset_p = -offset; | |
3003 | if (offset_p >= group_info->offset_map_size_n) | |
3004 | return 0; | |
3005 | return group_info->offset_map_n[offset_p]; | |
3006 | } | |
3007 | else | |
3008 | { | |
3009 | if (offset >= group_info->offset_map_size_p) | |
3010 | return 0; | |
3011 | return group_info->offset_map_p[offset]; | |
3012 | } | |
3013 | } | |
3014 | ||
3015 | ||
3016 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
3017 | may be NULL. */ | |
3018 | ||
b8698a0f | 3019 | static void |
6fb5fa3c DB |
3020 | scan_stores_nospill (store_info_t store_info, bitmap gen, bitmap kill) |
3021 | { | |
3022 | while (store_info) | |
3023 | { | |
3024 | HOST_WIDE_INT i; | |
b8698a0f | 3025 | group_info_t group_info |
9771b263 | 3026 | = rtx_group_vec[store_info->group_id]; |
6fb5fa3c DB |
3027 | if (group_info->process_globally) |
3028 | for (i = store_info->begin; i < store_info->end; i++) | |
3029 | { | |
3030 | int index = get_bitmap_index (group_info, i); | |
3031 | if (index != 0) | |
3032 | { | |
3033 | bitmap_set_bit (gen, index); | |
3034 | if (kill) | |
3035 | bitmap_clear_bit (kill, index); | |
3036 | } | |
3037 | } | |
3038 | store_info = store_info->next; | |
3039 | } | |
3040 | } | |
3041 | ||
3042 | ||
3043 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
3044 | may be NULL. */ | |
3045 | ||
b8698a0f | 3046 | static void |
6fb5fa3c DB |
3047 | scan_stores_spill (store_info_t store_info, bitmap gen, bitmap kill) |
3048 | { | |
3049 | while (store_info) | |
3050 | { | |
3051 | if (store_info->alias_set) | |
3052 | { | |
b8698a0f | 3053 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3054 | store_info->alias_set); |
3055 | if (index != 0) | |
3056 | { | |
3057 | bitmap_set_bit (gen, index); | |
3058 | if (kill) | |
3059 | bitmap_clear_bit (kill, index); | |
3060 | } | |
3061 | } | |
3062 | store_info = store_info->next; | |
3063 | } | |
3064 | } | |
3065 | ||
3066 | ||
3067 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3068 | may be NULL. */ | |
3069 | ||
3070 | static void | |
3071 | scan_reads_nospill (insn_info_t insn_info, bitmap gen, bitmap kill) | |
3072 | { | |
3073 | read_info_t read_info = insn_info->read_rec; | |
3074 | int i; | |
3075 | group_info_t group; | |
3076 | ||
64520bdc EB |
3077 | /* If this insn reads the frame, kill all the frame related stores. */ |
3078 | if (insn_info->frame_read) | |
3079 | { | |
9771b263 | 3080 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
64520bdc EB |
3081 | if (group->process_globally && group->frame_related) |
3082 | { | |
3083 | if (kill) | |
3084 | bitmap_ior_into (kill, group->group_kill); | |
b8698a0f | 3085 | bitmap_and_compl_into (gen, group->group_kill); |
64520bdc EB |
3086 | } |
3087 | } | |
d26c7090 ER |
3088 | if (insn_info->non_frame_wild_read) |
3089 | { | |
3090 | /* Kill all non-frame related stores. Kill all stores of variables that | |
3091 | escape. */ | |
3092 | if (kill) | |
3093 | bitmap_ior_into (kill, kill_on_calls); | |
3094 | bitmap_and_compl_into (gen, kill_on_calls); | |
9771b263 | 3095 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
d26c7090 ER |
3096 | if (group->process_globally && !group->frame_related) |
3097 | { | |
3098 | if (kill) | |
3099 | bitmap_ior_into (kill, group->group_kill); | |
3100 | bitmap_and_compl_into (gen, group->group_kill); | |
3101 | } | |
3102 | } | |
6fb5fa3c DB |
3103 | while (read_info) |
3104 | { | |
9771b263 | 3105 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
3106 | { |
3107 | if (group->process_globally) | |
3108 | { | |
3109 | if (i == read_info->group_id) | |
3110 | { | |
3111 | if (read_info->begin > read_info->end) | |
3112 | { | |
3113 | /* Begin > end for block mode reads. */ | |
3114 | if (kill) | |
3115 | bitmap_ior_into (kill, group->group_kill); | |
3116 | bitmap_and_compl_into (gen, group->group_kill); | |
3117 | } | |
3118 | else | |
3119 | { | |
3120 | /* The groups are the same, just process the | |
3121 | offsets. */ | |
3122 | HOST_WIDE_INT j; | |
3123 | for (j = read_info->begin; j < read_info->end; j++) | |
3124 | { | |
3125 | int index = get_bitmap_index (group, j); | |
3126 | if (index != 0) | |
3127 | { | |
3128 | if (kill) | |
3129 | bitmap_set_bit (kill, index); | |
3130 | bitmap_clear_bit (gen, index); | |
3131 | } | |
3132 | } | |
3133 | } | |
3134 | } | |
3135 | else | |
3136 | { | |
3137 | /* The groups are different, if the alias sets | |
3138 | conflict, clear the entire group. We only need | |
3139 | to apply this test if the read_info is a cselib | |
3140 | read. Anything with a constant base cannot alias | |
3141 | something else with a different constant | |
3142 | base. */ | |
3143 | if ((read_info->group_id < 0) | |
b8698a0f | 3144 | && canon_true_dependence (group->base_mem, |
d32f725a | 3145 | GET_MODE (group->base_mem), |
6216f94e | 3146 | group->canon_base_addr, |
53d9622b | 3147 | read_info->mem, NULL_RTX)) |
6fb5fa3c DB |
3148 | { |
3149 | if (kill) | |
3150 | bitmap_ior_into (kill, group->group_kill); | |
3151 | bitmap_and_compl_into (gen, group->group_kill); | |
3152 | } | |
3153 | } | |
3154 | } | |
3155 | } | |
b8698a0f | 3156 | |
6fb5fa3c DB |
3157 | read_info = read_info->next; |
3158 | } | |
3159 | } | |
3160 | ||
3161 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3162 | may be NULL. */ | |
3163 | ||
3164 | static void | |
3165 | scan_reads_spill (read_info_t read_info, bitmap gen, bitmap kill) | |
3166 | { | |
3167 | while (read_info) | |
3168 | { | |
3169 | if (read_info->alias_set) | |
3170 | { | |
b8698a0f | 3171 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3172 | read_info->alias_set); |
3173 | if (index != 0) | |
3174 | { | |
3175 | if (kill) | |
3176 | bitmap_set_bit (kill, index); | |
3177 | bitmap_clear_bit (gen, index); | |
3178 | } | |
3179 | } | |
b8698a0f | 3180 | |
6fb5fa3c DB |
3181 | read_info = read_info->next; |
3182 | } | |
3183 | } | |
3184 | ||
3185 | ||
3186 | /* Return the insn in BB_INFO before the first wild read or if there | |
3187 | are no wild reads in the block, return the last insn. */ | |
3188 | ||
3189 | static insn_info_t | |
3190 | find_insn_before_first_wild_read (bb_info_t bb_info) | |
3191 | { | |
3192 | insn_info_t insn_info = bb_info->last_insn; | |
3193 | insn_info_t last_wild_read = NULL; | |
3194 | ||
3195 | while (insn_info) | |
3196 | { | |
3197 | if (insn_info->wild_read) | |
3198 | { | |
3199 | last_wild_read = insn_info->prev_insn; | |
3200 | /* Block starts with wild read. */ | |
3201 | if (!last_wild_read) | |
3202 | return NULL; | |
3203 | } | |
3204 | ||
3205 | insn_info = insn_info->prev_insn; | |
3206 | } | |
3207 | ||
3208 | if (last_wild_read) | |
3209 | return last_wild_read; | |
3210 | else | |
3211 | return bb_info->last_insn; | |
3212 | } | |
3213 | ||
3214 | ||
3215 | /* Scan the insns in BB_INFO starting at PTR and going to the top of | |
3216 | the block in order to build the gen and kill sets for the block. | |
3217 | We start at ptr which may be the last insn in the block or may be | |
3218 | the first insn with a wild read. In the latter case we are able to | |
3219 | skip the rest of the block because it just does not matter: | |
3220 | anything that happens is hidden by the wild read. */ | |
3221 | ||
3222 | static void | |
3223 | dse_step3_scan (bool for_spills, basic_block bb) | |
3224 | { | |
3225 | bb_info_t bb_info = bb_table[bb->index]; | |
3226 | insn_info_t insn_info; | |
3227 | ||
3228 | if (for_spills) | |
3229 | /* There are no wild reads in the spill case. */ | |
3230 | insn_info = bb_info->last_insn; | |
3231 | else | |
3232 | insn_info = find_insn_before_first_wild_read (bb_info); | |
b8698a0f | 3233 | |
6fb5fa3c DB |
3234 | /* In the spill case or in the no_spill case if there is no wild |
3235 | read in the block, we will need a kill set. */ | |
3236 | if (insn_info == bb_info->last_insn) | |
3237 | { | |
3238 | if (bb_info->kill) | |
3239 | bitmap_clear (bb_info->kill); | |
3240 | else | |
3f9b14ff | 3241 | bb_info->kill = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c | 3242 | } |
b8698a0f | 3243 | else |
6fb5fa3c DB |
3244 | if (bb_info->kill) |
3245 | BITMAP_FREE (bb_info->kill); | |
3246 | ||
3247 | while (insn_info) | |
3248 | { | |
3249 | /* There may have been code deleted by the dce pass run before | |
3250 | this phase. */ | |
3251 | if (insn_info->insn && INSN_P (insn_info->insn)) | |
3252 | { | |
b8698a0f | 3253 | /* Process the read(s) last. */ |
6fb5fa3c DB |
3254 | if (for_spills) |
3255 | { | |
3256 | scan_stores_spill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3257 | scan_reads_spill (insn_info->read_rec, bb_info->gen, bb_info->kill); | |
3258 | } | |
3259 | else | |
3260 | { | |
3261 | scan_stores_nospill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3262 | scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill); | |
3263 | } | |
b8698a0f | 3264 | } |
6fb5fa3c DB |
3265 | |
3266 | insn_info = insn_info->prev_insn; | |
3267 | } | |
3268 | } | |
3269 | ||
3270 | ||
3271 | /* Set the gen set of the exit block, and also any block with no | |
3272 | successors that does not have a wild read. */ | |
3273 | ||
3274 | static void | |
3275 | dse_step3_exit_block_scan (bb_info_t bb_info) | |
3276 | { | |
3277 | /* The gen set is all 0's for the exit block except for the | |
3278 | frame_pointer_group. */ | |
b8698a0f | 3279 | |
6fb5fa3c DB |
3280 | if (stores_off_frame_dead_at_return) |
3281 | { | |
3282 | unsigned int i; | |
3283 | group_info_t group; | |
b8698a0f | 3284 | |
9771b263 | 3285 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
3286 | { |
3287 | if (group->process_globally && group->frame_related) | |
3288 | bitmap_ior_into (bb_info->gen, group->group_kill); | |
3289 | } | |
3290 | } | |
3291 | } | |
3292 | ||
3293 | ||
3294 | /* Find all of the blocks that are not backwards reachable from the | |
3295 | exit block or any block with no successors (BB). These are the | |
3296 | infinite loops or infinite self loops. These blocks will still | |
3297 | have their bits set in UNREACHABLE_BLOCKS. */ | |
3298 | ||
3299 | static void | |
3300 | mark_reachable_blocks (sbitmap unreachable_blocks, basic_block bb) | |
3301 | { | |
3302 | edge e; | |
3303 | edge_iterator ei; | |
3304 | ||
d7c028c0 | 3305 | if (bitmap_bit_p (unreachable_blocks, bb->index)) |
6fb5fa3c | 3306 | { |
d7c028c0 | 3307 | bitmap_clear_bit (unreachable_blocks, bb->index); |
6fb5fa3c | 3308 | FOR_EACH_EDGE (e, ei, bb->preds) |
b8698a0f | 3309 | { |
6fb5fa3c | 3310 | mark_reachable_blocks (unreachable_blocks, e->src); |
b8698a0f | 3311 | } |
6fb5fa3c DB |
3312 | } |
3313 | } | |
3314 | ||
3315 | /* Build the transfer functions for the function. */ | |
3316 | ||
3317 | static void | |
3318 | dse_step3 (bool for_spills) | |
3319 | { | |
3320 | basic_block bb; | |
8b1c6fd7 | 3321 | sbitmap unreachable_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
6fb5fa3c DB |
3322 | sbitmap_iterator sbi; |
3323 | bitmap all_ones = NULL; | |
3324 | unsigned int i; | |
b8698a0f | 3325 | |
f61e445a | 3326 | bitmap_ones (unreachable_blocks); |
6fb5fa3c | 3327 | |
04a90bec | 3328 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
3329 | { |
3330 | bb_info_t bb_info = bb_table[bb->index]; | |
3331 | if (bb_info->gen) | |
3332 | bitmap_clear (bb_info->gen); | |
3333 | else | |
3f9b14ff | 3334 | bb_info->gen = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3335 | |
3336 | if (bb->index == ENTRY_BLOCK) | |
3337 | ; | |
3338 | else if (bb->index == EXIT_BLOCK) | |
3339 | dse_step3_exit_block_scan (bb_info); | |
3340 | else | |
3341 | dse_step3_scan (for_spills, bb); | |
3342 | if (EDGE_COUNT (bb->succs) == 0) | |
3343 | mark_reachable_blocks (unreachable_blocks, bb); | |
3344 | ||
3345 | /* If this is the second time dataflow is run, delete the old | |
3346 | sets. */ | |
3347 | if (bb_info->in) | |
3348 | BITMAP_FREE (bb_info->in); | |
3349 | if (bb_info->out) | |
3350 | BITMAP_FREE (bb_info->out); | |
3351 | } | |
3352 | ||
3353 | /* For any block in an infinite loop, we must initialize the out set | |
3354 | to all ones. This could be expensive, but almost never occurs in | |
3355 | practice. However, it is common in regression tests. */ | |
d4ac4ce2 | 3356 | EXECUTE_IF_SET_IN_BITMAP (unreachable_blocks, 0, i, sbi) |
6fb5fa3c DB |
3357 | { |
3358 | if (bitmap_bit_p (all_blocks, i)) | |
3359 | { | |
3360 | bb_info_t bb_info = bb_table[i]; | |
3361 | if (!all_ones) | |
3362 | { | |
3363 | unsigned int j; | |
3364 | group_info_t group; | |
3365 | ||
3f9b14ff | 3366 | all_ones = BITMAP_ALLOC (&dse_bitmap_obstack); |
9771b263 | 3367 | FOR_EACH_VEC_ELT (rtx_group_vec, j, group) |
6fb5fa3c DB |
3368 | bitmap_ior_into (all_ones, group->group_kill); |
3369 | } | |
3370 | if (!bb_info->out) | |
3371 | { | |
3f9b14ff | 3372 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3373 | bitmap_copy (bb_info->out, all_ones); |
3374 | } | |
3375 | } | |
3376 | } | |
3377 | ||
3378 | if (all_ones) | |
3379 | BITMAP_FREE (all_ones); | |
3380 | sbitmap_free (unreachable_blocks); | |
3381 | } | |
3382 | ||
3383 | ||
3384 | \f | |
3385 | /*---------------------------------------------------------------------------- | |
3386 | Fourth step. | |
3387 | ||
3388 | Solve the bitvector equations. | |
3389 | ----------------------------------------------------------------------------*/ | |
3390 | ||
3391 | ||
3392 | /* Confluence function for blocks with no successors. Create an out | |
3393 | set from the gen set of the exit block. This block logically has | |
3394 | the exit block as a successor. */ | |
3395 | ||
3396 | ||
3397 | ||
3398 | static void | |
3399 | dse_confluence_0 (basic_block bb) | |
3400 | { | |
3401 | bb_info_t bb_info = bb_table[bb->index]; | |
3402 | ||
3403 | if (bb->index == EXIT_BLOCK) | |
3404 | return; | |
3405 | ||
3406 | if (!bb_info->out) | |
3407 | { | |
3f9b14ff | 3408 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3409 | bitmap_copy (bb_info->out, bb_table[EXIT_BLOCK]->gen); |
3410 | } | |
3411 | } | |
3412 | ||
3413 | /* Propagate the information from the in set of the dest of E to the | |
3414 | out set of the src of E. If the various in or out sets are not | |
3415 | there, that means they are all ones. */ | |
3416 | ||
1a0f3fa1 | 3417 | static bool |
6fb5fa3c DB |
3418 | dse_confluence_n (edge e) |
3419 | { | |
3420 | bb_info_t src_info = bb_table[e->src->index]; | |
3421 | bb_info_t dest_info = bb_table[e->dest->index]; | |
3422 | ||
3423 | if (dest_info->in) | |
3424 | { | |
3425 | if (src_info->out) | |
3426 | bitmap_and_into (src_info->out, dest_info->in); | |
3427 | else | |
3428 | { | |
3f9b14ff | 3429 | src_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3430 | bitmap_copy (src_info->out, dest_info->in); |
3431 | } | |
3432 | } | |
1a0f3fa1 | 3433 | return true; |
6fb5fa3c DB |
3434 | } |
3435 | ||
3436 | ||
3437 | /* Propagate the info from the out to the in set of BB_INDEX's basic | |
b8698a0f | 3438 | block. There are three cases: |
6fb5fa3c DB |
3439 | |
3440 | 1) The block has no kill set. In this case the kill set is all | |
3441 | ones. It does not matter what the out set of the block is, none of | |
3442 | the info can reach the top. The only thing that reaches the top is | |
3443 | the gen set and we just copy the set. | |
3444 | ||
3445 | 2) There is a kill set but no out set and bb has successors. In | |
3446 | this case we just return. Eventually an out set will be created and | |
3447 | it is better to wait than to create a set of ones. | |
3448 | ||
3449 | 3) There is both a kill and out set. We apply the obvious transfer | |
3450 | function. | |
3451 | */ | |
3452 | ||
3453 | static bool | |
3454 | dse_transfer_function (int bb_index) | |
3455 | { | |
3456 | bb_info_t bb_info = bb_table[bb_index]; | |
3457 | ||
3458 | if (bb_info->kill) | |
3459 | { | |
3460 | if (bb_info->out) | |
3461 | { | |
3462 | /* Case 3 above. */ | |
3463 | if (bb_info->in) | |
b8698a0f | 3464 | return bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3465 | bb_info->out, bb_info->kill); |
3466 | else | |
3467 | { | |
3f9b14ff | 3468 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
b8698a0f | 3469 | bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3470 | bb_info->out, bb_info->kill); |
3471 | return true; | |
3472 | } | |
3473 | } | |
3474 | else | |
3475 | /* Case 2 above. */ | |
3476 | return false; | |
3477 | } | |
3478 | else | |
3479 | { | |
3480 | /* Case 1 above. If there is already an in set, nothing | |
3481 | happens. */ | |
3482 | if (bb_info->in) | |
3483 | return false; | |
3484 | else | |
3485 | { | |
3f9b14ff | 3486 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3487 | bitmap_copy (bb_info->in, bb_info->gen); |
3488 | return true; | |
3489 | } | |
3490 | } | |
3491 | } | |
3492 | ||
3493 | /* Solve the dataflow equations. */ | |
3494 | ||
3495 | static void | |
3496 | dse_step4 (void) | |
3497 | { | |
b8698a0f L |
3498 | df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0, |
3499 | dse_confluence_n, dse_transfer_function, | |
3500 | all_blocks, df_get_postorder (DF_BACKWARD), | |
6fb5fa3c | 3501 | df_get_n_blocks (DF_BACKWARD)); |
456610d3 | 3502 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3503 | { |
3504 | basic_block bb; | |
3505 | ||
3506 | fprintf (dump_file, "\n\n*** Global dataflow info after analysis.\n"); | |
04a90bec | 3507 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
3508 | { |
3509 | bb_info_t bb_info = bb_table[bb->index]; | |
3510 | ||
3511 | df_print_bb_index (bb, dump_file); | |
3512 | if (bb_info->in) | |
3513 | bitmap_print (dump_file, bb_info->in, " in: ", "\n"); | |
3514 | else | |
3515 | fprintf (dump_file, " in: *MISSING*\n"); | |
3516 | if (bb_info->gen) | |
3517 | bitmap_print (dump_file, bb_info->gen, " gen: ", "\n"); | |
3518 | else | |
3519 | fprintf (dump_file, " gen: *MISSING*\n"); | |
3520 | if (bb_info->kill) | |
3521 | bitmap_print (dump_file, bb_info->kill, " kill: ", "\n"); | |
3522 | else | |
3523 | fprintf (dump_file, " kill: *MISSING*\n"); | |
3524 | if (bb_info->out) | |
3525 | bitmap_print (dump_file, bb_info->out, " out: ", "\n"); | |
3526 | else | |
3527 | fprintf (dump_file, " out: *MISSING*\n\n"); | |
3528 | } | |
3529 | } | |
3530 | } | |
3531 | ||
3532 | ||
3533 | \f | |
3534 | /*---------------------------------------------------------------------------- | |
3535 | Fifth step. | |
3536 | ||
0d52bcc1 | 3537 | Delete the stores that can only be deleted using the global information. |
6fb5fa3c DB |
3538 | ----------------------------------------------------------------------------*/ |
3539 | ||
3540 | ||
3541 | static void | |
3542 | dse_step5_nospill (void) | |
3543 | { | |
3544 | basic_block bb; | |
11cd3bed | 3545 | FOR_EACH_BB_FN (bb, cfun) |
6fb5fa3c DB |
3546 | { |
3547 | bb_info_t bb_info = bb_table[bb->index]; | |
3548 | insn_info_t insn_info = bb_info->last_insn; | |
3549 | bitmap v = bb_info->out; | |
3550 | ||
3551 | while (insn_info) | |
3552 | { | |
3553 | bool deleted = false; | |
3554 | if (dump_file && insn_info->insn) | |
3555 | { | |
3556 | fprintf (dump_file, "starting to process insn %d\n", | |
3557 | INSN_UID (insn_info->insn)); | |
3558 | bitmap_print (dump_file, v, " v: ", "\n"); | |
3559 | } | |
3560 | ||
3561 | /* There may have been code deleted by the dce pass run before | |
3562 | this phase. */ | |
b8698a0f | 3563 | if (insn_info->insn |
6fb5fa3c DB |
3564 | && INSN_P (insn_info->insn) |
3565 | && (!insn_info->cannot_delete) | |
3566 | && (!bitmap_empty_p (v))) | |
3567 | { | |
3568 | store_info_t store_info = insn_info->store_rec; | |
3569 | ||
3570 | /* Try to delete the current insn. */ | |
3571 | deleted = true; | |
b8698a0f | 3572 | |
6fb5fa3c DB |
3573 | /* Skip the clobbers. */ |
3574 | while (!store_info->is_set) | |
3575 | store_info = store_info->next; | |
3576 | ||
3577 | if (store_info->alias_set) | |
3578 | deleted = false; | |
3579 | else | |
3580 | { | |
3581 | HOST_WIDE_INT i; | |
b8698a0f | 3582 | group_info_t group_info |
9771b263 | 3583 | = rtx_group_vec[store_info->group_id]; |
b8698a0f | 3584 | |
6fb5fa3c DB |
3585 | for (i = store_info->begin; i < store_info->end; i++) |
3586 | { | |
3587 | int index = get_bitmap_index (group_info, i); | |
b8698a0f | 3588 | |
456610d3 | 3589 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 3590 | fprintf (dump_file, "i = %d, index = %d\n", (int)i, index); |
6fb5fa3c DB |
3591 | if (index == 0 || !bitmap_bit_p (v, index)) |
3592 | { | |
456610d3 | 3593 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 3594 | fprintf (dump_file, "failing at i = %d\n", (int)i); |
6fb5fa3c DB |
3595 | deleted = false; |
3596 | break; | |
3597 | } | |
3598 | } | |
3599 | } | |
3600 | if (deleted) | |
3601 | { | |
9e582b1d JR |
3602 | if (dbg_cnt (dse) |
3603 | && check_for_inc_dec_1 (insn_info)) | |
6fb5fa3c | 3604 | { |
6fb5fa3c DB |
3605 | delete_insn (insn_info->insn); |
3606 | insn_info->insn = NULL; | |
3607 | globally_deleted++; | |
3608 | } | |
3609 | } | |
3610 | } | |
3611 | /* We do want to process the local info if the insn was | |
6ed3da00 | 3612 | deleted. For instance, if the insn did a wild read, we |
6fb5fa3c | 3613 | no longer need to trash the info. */ |
b8698a0f | 3614 | if (insn_info->insn |
6fb5fa3c DB |
3615 | && INSN_P (insn_info->insn) |
3616 | && (!deleted)) | |
3617 | { | |
3618 | scan_stores_nospill (insn_info->store_rec, v, NULL); | |
3619 | if (insn_info->wild_read) | |
3620 | { | |
456610d3 | 3621 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3622 | fprintf (dump_file, "wild read\n"); |
3623 | bitmap_clear (v); | |
3624 | } | |
d26c7090 ER |
3625 | else if (insn_info->read_rec |
3626 | || insn_info->non_frame_wild_read) | |
6fb5fa3c | 3627 | { |
d26c7090 | 3628 | if (dump_file && !insn_info->non_frame_wild_read) |
6fb5fa3c | 3629 | fprintf (dump_file, "regular read\n"); |
456610d3 | 3630 | else if (dump_file && (dump_flags & TDF_DETAILS)) |
d26c7090 | 3631 | fprintf (dump_file, "non-frame wild read\n"); |
6fb5fa3c DB |
3632 | scan_reads_nospill (insn_info, v, NULL); |
3633 | } | |
3634 | } | |
b8698a0f | 3635 | |
6fb5fa3c DB |
3636 | insn_info = insn_info->prev_insn; |
3637 | } | |
3638 | } | |
3639 | } | |
3640 | ||
3641 | ||
6fb5fa3c DB |
3642 | \f |
3643 | /*---------------------------------------------------------------------------- | |
3644 | Sixth step. | |
3645 | ||
8dd5516b JJ |
3646 | Delete stores made redundant by earlier stores (which store the same |
3647 | value) that couldn't be eliminated. | |
3648 | ----------------------------------------------------------------------------*/ | |
3649 | ||
3650 | static void | |
3651 | dse_step6 (void) | |
3652 | { | |
3653 | basic_block bb; | |
3654 | ||
04a90bec | 3655 | FOR_ALL_BB_FN (bb, cfun) |
8dd5516b JJ |
3656 | { |
3657 | bb_info_t bb_info = bb_table[bb->index]; | |
3658 | insn_info_t insn_info = bb_info->last_insn; | |
3659 | ||
3660 | while (insn_info) | |
3661 | { | |
3662 | /* There may have been code deleted by the dce pass run before | |
3663 | this phase. */ | |
3664 | if (insn_info->insn | |
3665 | && INSN_P (insn_info->insn) | |
3666 | && !insn_info->cannot_delete) | |
3667 | { | |
3668 | store_info_t s_info = insn_info->store_rec; | |
3669 | ||
3670 | while (s_info && !s_info->is_set) | |
3671 | s_info = s_info->next; | |
3672 | if (s_info | |
3673 | && s_info->redundant_reason | |
3674 | && s_info->redundant_reason->insn | |
3675 | && INSN_P (s_info->redundant_reason->insn)) | |
3676 | { | |
eb92d49a | 3677 | rtx_insn *rinsn = s_info->redundant_reason->insn; |
456610d3 | 3678 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
3679 | fprintf (dump_file, "Locally deleting insn %d " |
3680 | "because insn %d stores the " | |
3681 | "same value and couldn't be " | |
3682 | "eliminated\n", | |
3683 | INSN_UID (insn_info->insn), | |
3684 | INSN_UID (rinsn)); | |
3685 | delete_dead_store_insn (insn_info); | |
3686 | } | |
3687 | } | |
3688 | insn_info = insn_info->prev_insn; | |
3689 | } | |
3690 | } | |
3691 | } | |
3692 | \f | |
3693 | /*---------------------------------------------------------------------------- | |
3694 | Seventh step. | |
3695 | ||
b8698a0f | 3696 | Destroy everything left standing. |
6fb5fa3c DB |
3697 | ----------------------------------------------------------------------------*/ |
3698 | ||
b8698a0f | 3699 | static void |
3f9b14ff | 3700 | dse_step7 (void) |
6fb5fa3c | 3701 | { |
3f9b14ff SB |
3702 | bitmap_obstack_release (&dse_bitmap_obstack); |
3703 | obstack_free (&dse_obstack, NULL); | |
370f38e8 | 3704 | |
6fb5fa3c DB |
3705 | end_alias_analysis (); |
3706 | free (bb_table); | |
c203e8a7 TS |
3707 | delete rtx_group_table; |
3708 | rtx_group_table = NULL; | |
9771b263 | 3709 | rtx_group_vec.release (); |
6fb5fa3c DB |
3710 | BITMAP_FREE (all_blocks); |
3711 | BITMAP_FREE (scratch); | |
3712 | ||
3713 | free_alloc_pool (rtx_store_info_pool); | |
3714 | free_alloc_pool (read_info_pool); | |
3715 | free_alloc_pool (insn_info_pool); | |
3716 | free_alloc_pool (bb_info_pool); | |
3717 | free_alloc_pool (rtx_group_info_pool); | |
3718 | free_alloc_pool (deferred_change_pool); | |
3719 | } | |
3720 | ||
3721 | ||
6fb5fa3c DB |
3722 | /* ------------------------------------------------------------------------- |
3723 | DSE | |
3724 | ------------------------------------------------------------------------- */ | |
3725 | ||
3726 | /* Callback for running pass_rtl_dse. */ | |
3727 | ||
3728 | static unsigned int | |
3729 | rest_of_handle_dse (void) | |
3730 | { | |
6fb5fa3c DB |
3731 | df_set_flags (DF_DEFER_INSN_RESCAN); |
3732 | ||
02b47899 KZ |
3733 | /* Need the notes since we must track live hardregs in the forwards |
3734 | direction. */ | |
3735 | df_note_add_problem (); | |
3736 | df_analyze (); | |
3737 | ||
6fb5fa3c DB |
3738 | dse_step0 (); |
3739 | dse_step1 (); | |
3740 | dse_step2_init (); | |
3741 | if (dse_step2_nospill ()) | |
3742 | { | |
3743 | df_set_flags (DF_LR_RUN_DCE); | |
3744 | df_analyze (); | |
456610d3 | 3745 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3746 | fprintf (dump_file, "doing global processing\n"); |
3747 | dse_step3 (false); | |
3748 | dse_step4 (); | |
3749 | dse_step5_nospill (); | |
3750 | } | |
3751 | ||
8dd5516b | 3752 | dse_step6 (); |
3f9b14ff | 3753 | dse_step7 (); |
6fb5fa3c DB |
3754 | |
3755 | if (dump_file) | |
3756 | fprintf (dump_file, "dse: local deletions = %d, global deletions = %d, spill deletions = %d\n", | |
3757 | locally_deleted, globally_deleted, spill_deleted); | |
6c5ed3f1 JJ |
3758 | |
3759 | /* DSE can eliminate potentially-trapping MEMs. | |
3760 | Remove any EH edges associated with them. */ | |
3761 | if ((locally_deleted || globally_deleted) | |
3762 | && cfun->can_throw_non_call_exceptions | |
3763 | && purge_all_dead_edges ()) | |
3764 | cleanup_cfg (0); | |
3765 | ||
6fb5fa3c DB |
3766 | return 0; |
3767 | } | |
3768 | ||
27a4cd48 DM |
3769 | namespace { |
3770 | ||
3771 | const pass_data pass_data_rtl_dse1 = | |
3772 | { | |
3773 | RTL_PASS, /* type */ | |
3774 | "dse1", /* name */ | |
3775 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3776 | TV_DSE1, /* tv_id */ |
3777 | 0, /* properties_required */ | |
3778 | 0, /* properties_provided */ | |
3779 | 0, /* properties_destroyed */ | |
3780 | 0, /* todo_flags_start */ | |
3bea341f | 3781 | TODO_df_finish, /* todo_flags_finish */ |
6fb5fa3c DB |
3782 | }; |
3783 | ||
27a4cd48 DM |
3784 | class pass_rtl_dse1 : public rtl_opt_pass |
3785 | { | |
3786 | public: | |
c3284718 RS |
3787 | pass_rtl_dse1 (gcc::context *ctxt) |
3788 | : rtl_opt_pass (pass_data_rtl_dse1, ctxt) | |
27a4cd48 DM |
3789 | {} |
3790 | ||
3791 | /* opt_pass methods: */ | |
1a3d085c TS |
3792 | virtual bool gate (function *) |
3793 | { | |
3794 | return optimize > 0 && flag_dse && dbg_cnt (dse1); | |
3795 | } | |
3796 | ||
be55bfe6 | 3797 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
27a4cd48 DM |
3798 | |
3799 | }; // class pass_rtl_dse1 | |
3800 | ||
3801 | } // anon namespace | |
3802 | ||
3803 | rtl_opt_pass * | |
3804 | make_pass_rtl_dse1 (gcc::context *ctxt) | |
3805 | { | |
3806 | return new pass_rtl_dse1 (ctxt); | |
3807 | } | |
3808 | ||
3809 | namespace { | |
3810 | ||
3811 | const pass_data pass_data_rtl_dse2 = | |
3812 | { | |
3813 | RTL_PASS, /* type */ | |
3814 | "dse2", /* name */ | |
3815 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3816 | TV_DSE2, /* tv_id */ |
3817 | 0, /* properties_required */ | |
3818 | 0, /* properties_provided */ | |
3819 | 0, /* properties_destroyed */ | |
3820 | 0, /* todo_flags_start */ | |
3bea341f | 3821 | TODO_df_finish, /* todo_flags_finish */ |
6fb5fa3c | 3822 | }; |
27a4cd48 DM |
3823 | |
3824 | class pass_rtl_dse2 : public rtl_opt_pass | |
3825 | { | |
3826 | public: | |
c3284718 RS |
3827 | pass_rtl_dse2 (gcc::context *ctxt) |
3828 | : rtl_opt_pass (pass_data_rtl_dse2, ctxt) | |
27a4cd48 DM |
3829 | {} |
3830 | ||
3831 | /* opt_pass methods: */ | |
1a3d085c TS |
3832 | virtual bool gate (function *) |
3833 | { | |
3834 | return optimize > 0 && flag_dse && dbg_cnt (dse2); | |
3835 | } | |
3836 | ||
be55bfe6 | 3837 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
27a4cd48 DM |
3838 | |
3839 | }; // class pass_rtl_dse2 | |
3840 | ||
3841 | } // anon namespace | |
3842 | ||
3843 | rtl_opt_pass * | |
3844 | make_pass_rtl_dse2 (gcc::context *ctxt) | |
3845 | { | |
3846 | return new pass_rtl_dse2 (ctxt); | |
3847 | } |