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6fb5fa3c | 1 | /* RTL dead store elimination. |
1b6fa860 | 2 | Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
457eeaae | 3 | Free Software Foundation, Inc. |
6fb5fa3c DB |
4 | |
5 | Contributed by Richard Sandiford <rsandifor@codesourcery.com> | |
6 | and Kenneth Zadeck <zadeck@naturalbridge.com> | |
7 | ||
8 | This file is part of GCC. | |
9 | ||
10 | GCC is free software; you can redistribute it and/or modify it under | |
11 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 12 | Software Foundation; either version 3, or (at your option) any later |
6fb5fa3c DB |
13 | version. |
14 | ||
15 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
16 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
17 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
18 | for more details. | |
19 | ||
20 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
21 | along with GCC; see the file COPYING3. If not see |
22 | <http://www.gnu.org/licenses/>. */ | |
6fb5fa3c DB |
23 | |
24 | #undef BASELINE | |
25 | ||
26 | #include "config.h" | |
27 | #include "system.h" | |
28 | #include "coretypes.h" | |
29 | #include "hashtab.h" | |
30 | #include "tm.h" | |
31 | #include "rtl.h" | |
32 | #include "tree.h" | |
18b526e8 | 33 | #include "tm_p.h" |
6fb5fa3c DB |
34 | #include "regs.h" |
35 | #include "hard-reg-set.h" | |
36 | #include "flags.h" | |
37 | #include "df.h" | |
38 | #include "cselib.h" | |
39 | #include "timevar.h" | |
40 | #include "tree-pass.h" | |
41 | #include "alloc-pool.h" | |
42 | #include "alias.h" | |
43 | #include "insn-config.h" | |
44 | #include "expr.h" | |
45 | #include "recog.h" | |
46 | #include "dse.h" | |
8660aaae | 47 | #include "optabs.h" |
6fb5fa3c | 48 | #include "dbgcnt.h" |
67d0afe9 | 49 | #include "target.h" |
dabd47e7 | 50 | #include "params.h" |
d26c7090 | 51 | #include "tree-flow.h" |
6fb5fa3c DB |
52 | |
53 | /* This file contains three techniques for performing Dead Store | |
b8698a0f | 54 | Elimination (dse). |
6fb5fa3c DB |
55 | |
56 | * The first technique performs dse locally on any base address. It | |
57 | is based on the cselib which is a local value numbering technique. | |
58 | This technique is local to a basic block but deals with a fairly | |
59 | general addresses. | |
b8698a0f | 60 | |
6fb5fa3c DB |
61 | * The second technique performs dse globally but is restricted to |
62 | base addresses that are either constant or are relative to the | |
63 | frame_pointer. | |
64 | ||
65 | * The third technique, (which is only done after register allocation) | |
66 | processes the spill spill slots. This differs from the second | |
67 | technique because it takes advantage of the fact that spilling is | |
68 | completely free from the effects of aliasing. | |
69 | ||
70 | Logically, dse is a backwards dataflow problem. A store can be | |
71 | deleted if it if cannot be reached in the backward direction by any | |
72 | use of the value being stored. However, the local technique uses a | |
73 | forwards scan of the basic block because cselib requires that the | |
74 | block be processed in that order. | |
75 | ||
76 | The pass is logically broken into 7 steps: | |
77 | ||
78 | 0) Initialization. | |
79 | ||
80 | 1) The local algorithm, as well as scanning the insns for the two | |
81 | global algorithms. | |
82 | ||
83 | 2) Analysis to see if the global algs are necessary. In the case | |
84 | of stores base on a constant address, there must be at least two | |
85 | stores to that address, to make it possible to delete some of the | |
86 | stores. In the case of stores off of the frame or spill related | |
87 | stores, only one store to an address is necessary because those | |
88 | stores die at the end of the function. | |
89 | ||
b8698a0f | 90 | 3) Set up the global dataflow equations based on processing the |
6fb5fa3c DB |
91 | info parsed in the first step. |
92 | ||
93 | 4) Solve the dataflow equations. | |
94 | ||
95 | 5) Delete the insns that the global analysis has indicated are | |
96 | unnecessary. | |
97 | ||
8dd5516b JJ |
98 | 6) Delete insns that store the same value as preceeding store |
99 | where the earlier store couldn't be eliminated. | |
100 | ||
101 | 7) Cleanup. | |
6fb5fa3c DB |
102 | |
103 | This step uses cselib and canon_rtx to build the largest expression | |
104 | possible for each address. This pass is a forwards pass through | |
105 | each basic block. From the point of view of the global technique, | |
106 | the first pass could examine a block in either direction. The | |
0d52bcc1 | 107 | forwards ordering is to accommodate cselib. |
6fb5fa3c DB |
108 | |
109 | We a simplifying assumption: addresses fall into four broad | |
110 | categories: | |
111 | ||
112 | 1) base has rtx_varies_p == false, offset is constant. | |
113 | 2) base has rtx_varies_p == false, offset variable. | |
114 | 3) base has rtx_varies_p == true, offset constant. | |
115 | 4) base has rtx_varies_p == true, offset variable. | |
116 | ||
117 | The local passes are able to process all 4 kinds of addresses. The | |
118 | global pass only handles (1). | |
119 | ||
120 | The global problem is formulated as follows: | |
121 | ||
122 | A store, S1, to address A, where A is not relative to the stack | |
123 | frame, can be eliminated if all paths from S1 to the end of the | |
124 | of the function contain another store to A before a read to A. | |
125 | ||
126 | If the address A is relative to the stack frame, a store S2 to A | |
127 | can be eliminated if there are no paths from S1 that reach the | |
128 | end of the function that read A before another store to A. In | |
129 | this case S2 can be deleted if there are paths to from S2 to the | |
130 | end of the function that have no reads or writes to A. This | |
131 | second case allows stores to the stack frame to be deleted that | |
132 | would otherwise die when the function returns. This cannot be | |
133 | done if stores_off_frame_dead_at_return is not true. See the doc | |
134 | for that variable for when this variable is false. | |
135 | ||
136 | The global problem is formulated as a backwards set union | |
137 | dataflow problem where the stores are the gens and reads are the | |
138 | kills. Set union problems are rare and require some special | |
139 | handling given our representation of bitmaps. A straightforward | |
140 | implementation of requires a lot of bitmaps filled with 1s. | |
141 | These are expensive and cumbersome in our bitmap formulation so | |
142 | care has been taken to avoid large vectors filled with 1s. See | |
143 | the comments in bb_info and in the dataflow confluence functions | |
b8698a0f | 144 | for details. |
6fb5fa3c DB |
145 | |
146 | There are two places for further enhancements to this algorithm: | |
b8698a0f | 147 | |
6fb5fa3c DB |
148 | 1) The original dse which was embedded in a pass called flow also |
149 | did local address forwarding. For example in | |
150 | ||
151 | A <- r100 | |
152 | ... <- A | |
153 | ||
154 | flow would replace the right hand side of the second insn with a | |
6ed3da00 | 155 | reference to r100. Most of the information is available to add this |
6fb5fa3c DB |
156 | to this pass. It has not done it because it is a lot of work in |
157 | the case that either r100 is assigned to between the first and | |
158 | second insn and/or the second insn is a load of part of the value | |
159 | stored by the first insn. | |
160 | ||
161 | insn 5 in gcc.c-torture/compile/990203-1.c simple case. | |
162 | insn 15 in gcc.c-torture/execute/20001017-2.c simple case. | |
163 | insn 25 in gcc.c-torture/execute/20001026-1.c simple case. | |
164 | insn 44 in gcc.c-torture/execute/20010910-1.c simple case. | |
165 | ||
166 | 2) The cleaning up of spill code is quite profitable. It currently | |
167 | depends on reading tea leaves and chicken entrails left by reload. | |
168 | This pass depends on reload creating a singleton alias set for each | |
169 | spill slot and telling the next dse pass which of these alias sets | |
170 | are the singletons. Rather than analyze the addresses of the | |
171 | spills, dse's spill processing just does analysis of the loads and | |
172 | stores that use those alias sets. There are three cases where this | |
173 | falls short: | |
174 | ||
175 | a) Reload sometimes creates the slot for one mode of access, and | |
176 | then inserts loads and/or stores for a smaller mode. In this | |
177 | case, the current code just punts on the slot. The proper thing | |
178 | to do is to back out and use one bit vector position for each | |
179 | byte of the entity associated with the slot. This depends on | |
180 | KNOWING that reload always generates the accesses for each of the | |
181 | bytes in some canonical (read that easy to understand several | |
182 | passes after reload happens) way. | |
183 | ||
184 | b) Reload sometimes decides that spill slot it allocated was not | |
185 | large enough for the mode and goes back and allocates more slots | |
186 | with the same mode and alias set. The backout in this case is a | |
187 | little more graceful than (a). In this case the slot is unmarked | |
188 | as being a spill slot and if final address comes out to be based | |
b8698a0f | 189 | off the frame pointer, the global algorithm handles this slot. |
6fb5fa3c DB |
190 | |
191 | c) For any pass that may prespill, there is currently no | |
192 | mechanism to tell the dse pass that the slot being used has the | |
193 | special properties that reload uses. It may be that all that is | |
0d52bcc1 | 194 | required is to have those passes make the same calls that reload |
6fb5fa3c DB |
195 | does, assuming that the alias sets can be manipulated in the same |
196 | way. */ | |
197 | ||
198 | /* There are limits to the size of constant offsets we model for the | |
199 | global problem. There are certainly test cases, that exceed this | |
200 | limit, however, it is unlikely that there are important programs | |
201 | that really have constant offsets this size. */ | |
202 | #define MAX_OFFSET (64 * 1024) | |
203 | ||
204 | ||
205 | static bitmap scratch = NULL; | |
206 | struct insn_info; | |
207 | ||
208 | /* This structure holds information about a candidate store. */ | |
b8698a0f | 209 | struct store_info |
6fb5fa3c DB |
210 | { |
211 | ||
212 | /* False means this is a clobber. */ | |
213 | bool is_set; | |
214 | ||
8dd5516b JJ |
215 | /* False if a single HOST_WIDE_INT bitmap is used for positions_needed. */ |
216 | bool is_large; | |
217 | ||
6fb5fa3c DB |
218 | /* The id of the mem group of the base address. If rtx_varies_p is |
219 | true, this is -1. Otherwise, it is the index into the group | |
220 | table. */ | |
221 | int group_id; | |
b8698a0f | 222 | |
6fb5fa3c DB |
223 | /* This is the cselib value. */ |
224 | cselib_val *cse_base; | |
225 | ||
226 | /* This canonized mem. */ | |
227 | rtx mem; | |
228 | ||
6216f94e | 229 | /* Canonized MEM address for use by canon_true_dependence. */ |
6fb5fa3c DB |
230 | rtx mem_addr; |
231 | ||
232 | /* If this is non-zero, it is the alias set of a spill location. */ | |
4862826d | 233 | alias_set_type alias_set; |
6fb5fa3c DB |
234 | |
235 | /* The offset of the first and byte before the last byte associated | |
236 | with the operation. */ | |
8dd5516b JJ |
237 | HOST_WIDE_INT begin, end; |
238 | ||
239 | union | |
240 | { | |
241 | /* A bitmask as wide as the number of bytes in the word that | |
242 | contains a 1 if the byte may be needed. The store is unused if | |
243 | all of the bits are 0. This is used if IS_LARGE is false. */ | |
244 | unsigned HOST_WIDE_INT small_bitmask; | |
245 | ||
246 | struct | |
247 | { | |
248 | /* A bitmap with one bit per byte. Cleared bit means the position | |
249 | is needed. Used if IS_LARGE is false. */ | |
dc491a25 | 250 | bitmap bmap; |
6fb5fa3c | 251 | |
8dd5516b JJ |
252 | /* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is |
253 | equal to END - BEGIN, the whole store is unused. */ | |
254 | int count; | |
255 | } large; | |
256 | } positions_needed; | |
6fb5fa3c DB |
257 | |
258 | /* The next store info for this insn. */ | |
259 | struct store_info *next; | |
260 | ||
261 | /* The right hand side of the store. This is used if there is a | |
262 | subsequent reload of the mems address somewhere later in the | |
263 | basic block. */ | |
8dd5516b JJ |
264 | rtx rhs; |
265 | ||
266 | /* If rhs is or holds a constant, this contains that constant, | |
267 | otherwise NULL. */ | |
268 | rtx const_rhs; | |
269 | ||
270 | /* Set if this store stores the same constant value as REDUNDANT_REASON | |
271 | insn stored. These aren't eliminated early, because doing that | |
272 | might prevent the earlier larger store to be eliminated. */ | |
273 | struct insn_info *redundant_reason; | |
6fb5fa3c DB |
274 | }; |
275 | ||
4fe663b0 L |
276 | /* Return a bitmask with the first N low bits set. */ |
277 | ||
278 | static unsigned HOST_WIDE_INT | |
279 | lowpart_bitmask (int n) | |
280 | { | |
281 | unsigned HOST_WIDE_INT mask = ~(unsigned HOST_WIDE_INT) 0; | |
282 | return mask >> (HOST_BITS_PER_WIDE_INT - n); | |
283 | } | |
284 | ||
6fb5fa3c DB |
285 | typedef struct store_info *store_info_t; |
286 | static alloc_pool cse_store_info_pool; | |
287 | static alloc_pool rtx_store_info_pool; | |
288 | ||
289 | /* This structure holds information about a load. These are only | |
290 | built for rtx bases. */ | |
b8698a0f | 291 | struct read_info |
6fb5fa3c DB |
292 | { |
293 | /* The id of the mem group of the base address. */ | |
294 | int group_id; | |
295 | ||
296 | /* If this is non-zero, it is the alias set of a spill location. */ | |
4862826d | 297 | alias_set_type alias_set; |
6fb5fa3c DB |
298 | |
299 | /* The offset of the first and byte after the last byte associated | |
300 | with the operation. If begin == end == 0, the read did not have | |
301 | a constant offset. */ | |
302 | int begin, end; | |
303 | ||
304 | /* The mem being read. */ | |
305 | rtx mem; | |
306 | ||
307 | /* The next read_info for this insn. */ | |
308 | struct read_info *next; | |
309 | }; | |
310 | typedef struct read_info *read_info_t; | |
311 | static alloc_pool read_info_pool; | |
312 | ||
313 | ||
314 | /* One of these records is created for each insn. */ | |
315 | ||
b8698a0f | 316 | struct insn_info |
6fb5fa3c DB |
317 | { |
318 | /* Set true if the insn contains a store but the insn itself cannot | |
319 | be deleted. This is set if the insn is a parallel and there is | |
320 | more than one non dead output or if the insn is in some way | |
321 | volatile. */ | |
322 | bool cannot_delete; | |
323 | ||
324 | /* This field is only used by the global algorithm. It is set true | |
325 | if the insn contains any read of mem except for a (1). This is | |
326 | also set if the insn is a call or has a clobber mem. If the insn | |
327 | contains a wild read, the use_rec will be null. */ | |
328 | bool wild_read; | |
329 | ||
d26c7090 ER |
330 | /* This is true only for CALL instructions which could potentially read |
331 | any non-frame memory location. This field is used by the global | |
332 | algorithm. */ | |
333 | bool non_frame_wild_read; | |
334 | ||
50f0f366 EB |
335 | /* This field is only used for the processing of const functions. |
336 | These functions cannot read memory, but they can read the stack | |
64520bdc EB |
337 | because that is where they may get their parms. We need to be |
338 | this conservative because, like the store motion pass, we don't | |
339 | consider CALL_INSN_FUNCTION_USAGE when processing call insns. | |
340 | Moreover, we need to distinguish two cases: | |
341 | 1. Before reload (register elimination), the stores related to | |
342 | outgoing arguments are stack pointer based and thus deemed | |
343 | of non-constant base in this pass. This requires special | |
344 | handling but also means that the frame pointer based stores | |
345 | need not be killed upon encountering a const function call. | |
346 | 2. After reload, the stores related to outgoing arguments can be | |
347 | either stack pointer or hard frame pointer based. This means | |
348 | that we have no other choice than also killing all the frame | |
349 | pointer based stores upon encountering a const function call. | |
350 | This field is set after reload for const function calls. Having | |
351 | this set is less severe than a wild read, it just means that all | |
352 | the frame related stores are killed rather than all the stores. */ | |
353 | bool frame_read; | |
354 | ||
355 | /* This field is only used for the processing of const functions. | |
356 | It is set if the insn may contain a stack pointer based store. */ | |
50f0f366 | 357 | bool stack_pointer_based; |
6fb5fa3c DB |
358 | |
359 | /* This is true if any of the sets within the store contains a | |
360 | cselib base. Such stores can only be deleted by the local | |
361 | algorithm. */ | |
362 | bool contains_cselib_groups; | |
363 | ||
364 | /* The insn. */ | |
365 | rtx insn; | |
366 | ||
367 | /* The list of mem sets or mem clobbers that are contained in this | |
368 | insn. If the insn is deletable, it contains only one mem set. | |
369 | But it could also contain clobbers. Insns that contain more than | |
370 | one mem set are not deletable, but each of those mems are here in | |
6ed3da00 | 371 | order to provide info to delete other insns. */ |
6fb5fa3c DB |
372 | store_info_t store_rec; |
373 | ||
374 | /* The linked list of mem uses in this insn. Only the reads from | |
375 | rtx bases are listed here. The reads to cselib bases are | |
376 | completely processed during the first scan and so are never | |
377 | created. */ | |
378 | read_info_t read_rec; | |
379 | ||
380 | /* The prev insn in the basic block. */ | |
381 | struct insn_info * prev_insn; | |
382 | ||
383 | /* The linked list of insns that are in consideration for removal in | |
384 | the forwards pass thru the basic block. This pointer may be | |
385 | trash as it is not cleared when a wild read occurs. The only | |
fa10beec | 386 | time it is guaranteed to be correct is when the traversal starts |
6fb5fa3c DB |
387 | at active_local_stores. */ |
388 | struct insn_info * next_local_store; | |
389 | }; | |
390 | ||
391 | typedef struct insn_info *insn_info_t; | |
392 | static alloc_pool insn_info_pool; | |
393 | ||
394 | /* The linked list of stores that are under consideration in this | |
b8698a0f | 395 | basic block. */ |
6fb5fa3c | 396 | static insn_info_t active_local_stores; |
dabd47e7 | 397 | static int active_local_stores_len; |
6fb5fa3c | 398 | |
b8698a0f | 399 | struct bb_info |
6fb5fa3c DB |
400 | { |
401 | ||
402 | /* Pointer to the insn info for the last insn in the block. These | |
403 | are linked so this is how all of the insns are reached. During | |
404 | scanning this is the current insn being scanned. */ | |
405 | insn_info_t last_insn; | |
406 | ||
407 | /* The info for the global dataflow problem. */ | |
408 | ||
409 | ||
410 | /* This is set if the transfer function should and in the wild_read | |
411 | bitmap before applying the kill and gen sets. That vector knocks | |
412 | out most of the bits in the bitmap and thus speeds up the | |
413 | operations. */ | |
414 | bool apply_wild_read; | |
415 | ||
02b47899 KZ |
416 | /* The following 4 bitvectors hold information about which positions |
417 | of which stores are live or dead. They are indexed by | |
418 | get_bitmap_index. */ | |
419 | ||
6fb5fa3c DB |
420 | /* The set of store positions that exist in this block before a wild read. */ |
421 | bitmap gen; | |
b8698a0f | 422 | |
6fb5fa3c DB |
423 | /* The set of load positions that exist in this block above the |
424 | same position of a store. */ | |
425 | bitmap kill; | |
426 | ||
427 | /* The set of stores that reach the top of the block without being | |
428 | killed by a read. | |
429 | ||
430 | Do not represent the in if it is all ones. Note that this is | |
431 | what the bitvector should logically be initialized to for a set | |
432 | intersection problem. However, like the kill set, this is too | |
433 | expensive. So initially, the in set will only be created for the | |
434 | exit block and any block that contains a wild read. */ | |
435 | bitmap in; | |
436 | ||
437 | /* The set of stores that reach the bottom of the block from it's | |
438 | successors. | |
439 | ||
440 | Do not represent the in if it is all ones. Note that this is | |
441 | what the bitvector should logically be initialized to for a set | |
442 | intersection problem. However, like the kill and in set, this is | |
443 | too expensive. So what is done is that the confluence operator | |
444 | just initializes the vector from one of the out sets of the | |
445 | successors of the block. */ | |
446 | bitmap out; | |
02b47899 KZ |
447 | |
448 | /* The following bitvector is indexed by the reg number. It | |
449 | contains the set of regs that are live at the current instruction | |
450 | being processed. While it contains info for all of the | |
451 | registers, only the pseudos are actually examined. It is used to | |
452 | assure that shift sequences that are inserted do not accidently | |
453 | clobber live hard regs. */ | |
454 | bitmap regs_live; | |
6fb5fa3c DB |
455 | }; |
456 | ||
457 | typedef struct bb_info *bb_info_t; | |
458 | static alloc_pool bb_info_pool; | |
459 | ||
460 | /* Table to hold all bb_infos. */ | |
461 | static bb_info_t *bb_table; | |
462 | ||
463 | /* There is a group_info for each rtx base that is used to reference | |
464 | memory. There are also not many of the rtx bases because they are | |
465 | very limited in scope. */ | |
466 | ||
b8698a0f | 467 | struct group_info |
6fb5fa3c DB |
468 | { |
469 | /* The actual base of the address. */ | |
470 | rtx rtx_base; | |
471 | ||
472 | /* The sequential id of the base. This allows us to have a | |
473 | canonical ordering of these that is not based on addresses. */ | |
474 | int id; | |
475 | ||
8f5929e1 JJ |
476 | /* True if there are any positions that are to be processed |
477 | globally. */ | |
478 | bool process_globally; | |
479 | ||
480 | /* True if the base of this group is either the frame_pointer or | |
481 | hard_frame_pointer. */ | |
482 | bool frame_related; | |
483 | ||
d32f725a OH |
484 | /* A mem wrapped around the base pointer for the group in order to do |
485 | read dependency. It must be given BLKmode in order to encompass all | |
486 | the possible offsets from the base. */ | |
6fb5fa3c | 487 | rtx base_mem; |
b8698a0f | 488 | |
6216f94e JJ |
489 | /* Canonized version of base_mem's address. */ |
490 | rtx canon_base_addr; | |
6fb5fa3c DB |
491 | |
492 | /* These two sets of two bitmaps are used to keep track of how many | |
6ed3da00 | 493 | stores are actually referencing that position from this base. We |
6fb5fa3c | 494 | only do this for rtx bases as this will be used to assign |
6ed3da00 | 495 | positions in the bitmaps for the global problem. Bit N is set in |
6fb5fa3c DB |
496 | store1 on the first store for offset N. Bit N is set in store2 |
497 | for the second store to offset N. This is all we need since we | |
498 | only care about offsets that have two or more stores for them. | |
499 | ||
500 | The "_n" suffix is for offsets less than 0 and the "_p" suffix is | |
501 | for 0 and greater offsets. | |
502 | ||
503 | There is one special case here, for stores into the stack frame, | |
504 | we will or store1 into store2 before deciding which stores look | |
505 | at globally. This is because stores to the stack frame that have | |
506 | no other reads before the end of the function can also be | |
507 | deleted. */ | |
508 | bitmap store1_n, store1_p, store2_n, store2_p; | |
509 | ||
d26c7090 ER |
510 | /* These bitmaps keep track of offsets in this group escape this function. |
511 | An offset escapes if it corresponds to a named variable whose | |
512 | addressable flag is set. */ | |
513 | bitmap escaped_n, escaped_p; | |
514 | ||
6ed3da00 | 515 | /* The positions in this bitmap have the same assignments as the in, |
6fb5fa3c | 516 | out, gen and kill bitmaps. This bitmap is all zeros except for |
6ed3da00 | 517 | the positions that are occupied by stores for this group. */ |
6fb5fa3c DB |
518 | bitmap group_kill; |
519 | ||
6fb5fa3c | 520 | /* The offset_map is used to map the offsets from this base into |
6ed3da00 | 521 | positions in the global bitmaps. It is only created after all of |
6fb5fa3c DB |
522 | the all of stores have been scanned and we know which ones we |
523 | care about. */ | |
b8698a0f L |
524 | int *offset_map_n, *offset_map_p; |
525 | int offset_map_size_n, offset_map_size_p; | |
6fb5fa3c DB |
526 | }; |
527 | typedef struct group_info *group_info_t; | |
5f754896 | 528 | typedef const struct group_info *const_group_info_t; |
6fb5fa3c DB |
529 | static alloc_pool rtx_group_info_pool; |
530 | ||
531 | /* Tables of group_info structures, hashed by base value. */ | |
532 | static htab_t rtx_group_table; | |
533 | ||
534 | /* Index into the rtx_group_vec. */ | |
535 | static int rtx_group_next_id; | |
536 | ||
537 | DEF_VEC_P(group_info_t); | |
538 | DEF_VEC_ALLOC_P(group_info_t,heap); | |
539 | ||
540 | static VEC(group_info_t,heap) *rtx_group_vec; | |
541 | ||
542 | ||
543 | /* This structure holds the set of changes that are being deferred | |
544 | when removing read operation. See replace_read. */ | |
b8698a0f | 545 | struct deferred_change |
6fb5fa3c DB |
546 | { |
547 | ||
548 | /* The mem that is being replaced. */ | |
549 | rtx *loc; | |
550 | ||
551 | /* The reg it is being replaced with. */ | |
552 | rtx reg; | |
553 | ||
554 | struct deferred_change *next; | |
555 | }; | |
556 | ||
557 | typedef struct deferred_change *deferred_change_t; | |
558 | static alloc_pool deferred_change_pool; | |
559 | ||
560 | static deferred_change_t deferred_change_list = NULL; | |
561 | ||
562 | /* This are used to hold the alias sets of spill variables. Since | |
563 | these are never aliased and there may be a lot of them, it makes | |
564 | sense to treat them specially. This bitvector is only allocated in | |
565 | calls from dse_record_singleton_alias_set which currently is only | |
566 | made during reload1. So when dse is called before reload this | |
567 | mechanism does nothing. */ | |
568 | ||
569 | static bitmap clear_alias_sets = NULL; | |
570 | ||
571 | /* The set of clear_alias_sets that have been disqualified because | |
572 | there are loads or stores using a different mode than the alias set | |
b8698a0f | 573 | was registered with. */ |
6fb5fa3c DB |
574 | static bitmap disqualified_clear_alias_sets = NULL; |
575 | ||
576 | /* The group that holds all of the clear_alias_sets. */ | |
577 | static group_info_t clear_alias_group; | |
578 | ||
579 | /* The modes of the clear_alias_sets. */ | |
580 | static htab_t clear_alias_mode_table; | |
581 | ||
582 | /* Hash table element to look up the mode for an alias set. */ | |
583 | struct clear_alias_mode_holder | |
584 | { | |
4862826d | 585 | alias_set_type alias_set; |
6fb5fa3c DB |
586 | enum machine_mode mode; |
587 | }; | |
588 | ||
589 | static alloc_pool clear_alias_mode_pool; | |
590 | ||
e3b5732b | 591 | /* This is true except if cfun->stdarg -- i.e. we cannot do |
9dd9bf80 | 592 | this for vararg functions because they play games with the frame. */ |
6fb5fa3c DB |
593 | static bool stores_off_frame_dead_at_return; |
594 | ||
595 | /* Counter for stats. */ | |
b8698a0f L |
596 | static int globally_deleted; |
597 | static int locally_deleted; | |
598 | static int spill_deleted; | |
599 | ||
6fb5fa3c DB |
600 | static bitmap all_blocks; |
601 | ||
d26c7090 ER |
602 | /* Locations that are killed by calls in the global phase. */ |
603 | static bitmap kill_on_calls; | |
604 | ||
6fb5fa3c DB |
605 | /* The number of bits used in the global bitmaps. */ |
606 | static unsigned int current_position; | |
607 | ||
608 | ||
609 | static bool gate_dse (void); | |
7d817ebc DE |
610 | static bool gate_dse1 (void); |
611 | static bool gate_dse2 (void); | |
6fb5fa3c DB |
612 | |
613 | \f | |
614 | /*---------------------------------------------------------------------------- | |
615 | Zeroth step. | |
616 | ||
b8698a0f | 617 | Initialization. |
6fb5fa3c DB |
618 | ----------------------------------------------------------------------------*/ |
619 | ||
620 | /* Hashtable callbacks for maintaining the "bases" field of | |
621 | store_group_info, given that the addresses are function invariants. */ | |
622 | ||
623 | static int | |
624 | clear_alias_mode_eq (const void *p1, const void *p2) | |
625 | { | |
b8698a0f | 626 | const struct clear_alias_mode_holder * h1 |
6fb5fa3c | 627 | = (const struct clear_alias_mode_holder *) p1; |
b8698a0f | 628 | const struct clear_alias_mode_holder * h2 |
6fb5fa3c DB |
629 | = (const struct clear_alias_mode_holder *) p2; |
630 | return h1->alias_set == h2->alias_set; | |
631 | } | |
632 | ||
633 | ||
634 | static hashval_t | |
635 | clear_alias_mode_hash (const void *p) | |
636 | { | |
b8698a0f | 637 | const struct clear_alias_mode_holder *holder |
6fb5fa3c DB |
638 | = (const struct clear_alias_mode_holder *) p; |
639 | return holder->alias_set; | |
640 | } | |
641 | ||
642 | ||
643 | /* Find the entry associated with ALIAS_SET. */ | |
644 | ||
645 | static struct clear_alias_mode_holder * | |
4862826d | 646 | clear_alias_set_lookup (alias_set_type alias_set) |
6fb5fa3c DB |
647 | { |
648 | struct clear_alias_mode_holder tmp_holder; | |
649 | void **slot; | |
b8698a0f | 650 | |
6fb5fa3c DB |
651 | tmp_holder.alias_set = alias_set; |
652 | slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, NO_INSERT); | |
653 | gcc_assert (*slot); | |
b8698a0f | 654 | |
f883e0a7 | 655 | return (struct clear_alias_mode_holder *) *slot; |
6fb5fa3c DB |
656 | } |
657 | ||
658 | ||
659 | /* Hashtable callbacks for maintaining the "bases" field of | |
660 | store_group_info, given that the addresses are function invariants. */ | |
661 | ||
662 | static int | |
663 | invariant_group_base_eq (const void *p1, const void *p2) | |
664 | { | |
5f754896 KG |
665 | const_group_info_t gi1 = (const_group_info_t) p1; |
666 | const_group_info_t gi2 = (const_group_info_t) p2; | |
6fb5fa3c DB |
667 | return rtx_equal_p (gi1->rtx_base, gi2->rtx_base); |
668 | } | |
669 | ||
670 | ||
671 | static hashval_t | |
672 | invariant_group_base_hash (const void *p) | |
673 | { | |
5f754896 | 674 | const_group_info_t gi = (const_group_info_t) p; |
6fb5fa3c DB |
675 | int do_not_record; |
676 | return hash_rtx (gi->rtx_base, Pmode, &do_not_record, NULL, false); | |
677 | } | |
678 | ||
679 | ||
680 | /* Get the GROUP for BASE. Add a new group if it is not there. */ | |
681 | ||
682 | static group_info_t | |
683 | get_group_info (rtx base) | |
684 | { | |
b8698a0f L |
685 | struct group_info tmp_gi; |
686 | group_info_t gi; | |
6fb5fa3c DB |
687 | void **slot; |
688 | ||
689 | if (base) | |
690 | { | |
691 | /* Find the store_base_info structure for BASE, creating a new one | |
692 | if necessary. */ | |
693 | tmp_gi.rtx_base = base; | |
694 | slot = htab_find_slot (rtx_group_table, &tmp_gi, INSERT); | |
695 | gi = (group_info_t) *slot; | |
696 | } | |
697 | else | |
698 | { | |
699 | if (!clear_alias_group) | |
700 | { | |
f883e0a7 KG |
701 | clear_alias_group = gi = |
702 | (group_info_t) pool_alloc (rtx_group_info_pool); | |
6fb5fa3c DB |
703 | memset (gi, 0, sizeof (struct group_info)); |
704 | gi->id = rtx_group_next_id++; | |
705 | gi->store1_n = BITMAP_ALLOC (NULL); | |
706 | gi->store1_p = BITMAP_ALLOC (NULL); | |
707 | gi->store2_n = BITMAP_ALLOC (NULL); | |
708 | gi->store2_p = BITMAP_ALLOC (NULL); | |
d26c7090 ER |
709 | gi->escaped_p = BITMAP_ALLOC (NULL); |
710 | gi->escaped_n = BITMAP_ALLOC (NULL); | |
6fb5fa3c DB |
711 | gi->group_kill = BITMAP_ALLOC (NULL); |
712 | gi->process_globally = false; | |
713 | gi->offset_map_size_n = 0; | |
714 | gi->offset_map_size_p = 0; | |
715 | gi->offset_map_n = NULL; | |
716 | gi->offset_map_p = NULL; | |
717 | VEC_safe_push (group_info_t, heap, rtx_group_vec, gi); | |
718 | } | |
719 | return clear_alias_group; | |
720 | } | |
721 | ||
722 | if (gi == NULL) | |
723 | { | |
f883e0a7 | 724 | *slot = gi = (group_info_t) pool_alloc (rtx_group_info_pool); |
6fb5fa3c DB |
725 | gi->rtx_base = base; |
726 | gi->id = rtx_group_next_id++; | |
d32f725a | 727 | gi->base_mem = gen_rtx_MEM (BLKmode, base); |
6216f94e | 728 | gi->canon_base_addr = canon_rtx (base); |
6fb5fa3c DB |
729 | gi->store1_n = BITMAP_ALLOC (NULL); |
730 | gi->store1_p = BITMAP_ALLOC (NULL); | |
731 | gi->store2_n = BITMAP_ALLOC (NULL); | |
732 | gi->store2_p = BITMAP_ALLOC (NULL); | |
d26c7090 ER |
733 | gi->escaped_p = BITMAP_ALLOC (NULL); |
734 | gi->escaped_n = BITMAP_ALLOC (NULL); | |
6fb5fa3c DB |
735 | gi->group_kill = BITMAP_ALLOC (NULL); |
736 | gi->process_globally = false; | |
b8698a0f | 737 | gi->frame_related = |
6fb5fa3c DB |
738 | (base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx); |
739 | gi->offset_map_size_n = 0; | |
740 | gi->offset_map_size_p = 0; | |
741 | gi->offset_map_n = NULL; | |
742 | gi->offset_map_p = NULL; | |
743 | VEC_safe_push (group_info_t, heap, rtx_group_vec, gi); | |
744 | } | |
745 | ||
746 | return gi; | |
747 | } | |
748 | ||
749 | ||
750 | /* Initialization of data structures. */ | |
751 | ||
752 | static void | |
753 | dse_step0 (void) | |
754 | { | |
755 | locally_deleted = 0; | |
756 | globally_deleted = 0; | |
757 | spill_deleted = 0; | |
758 | ||
759 | scratch = BITMAP_ALLOC (NULL); | |
d26c7090 | 760 | kill_on_calls = BITMAP_ALLOC (NULL); |
6fb5fa3c DB |
761 | |
762 | rtx_store_info_pool | |
b8698a0f | 763 | = create_alloc_pool ("rtx_store_info_pool", |
6fb5fa3c DB |
764 | sizeof (struct store_info), 100); |
765 | read_info_pool | |
b8698a0f | 766 | = create_alloc_pool ("read_info_pool", |
6fb5fa3c DB |
767 | sizeof (struct read_info), 100); |
768 | insn_info_pool | |
b8698a0f | 769 | = create_alloc_pool ("insn_info_pool", |
6fb5fa3c DB |
770 | sizeof (struct insn_info), 100); |
771 | bb_info_pool | |
b8698a0f | 772 | = create_alloc_pool ("bb_info_pool", |
6fb5fa3c DB |
773 | sizeof (struct bb_info), 100); |
774 | rtx_group_info_pool | |
b8698a0f | 775 | = create_alloc_pool ("rtx_group_info_pool", |
6fb5fa3c DB |
776 | sizeof (struct group_info), 100); |
777 | deferred_change_pool | |
b8698a0f | 778 | = create_alloc_pool ("deferred_change_pool", |
6fb5fa3c DB |
779 | sizeof (struct deferred_change), 10); |
780 | ||
781 | rtx_group_table = htab_create (11, invariant_group_base_hash, | |
782 | invariant_group_base_eq, NULL); | |
783 | ||
784 | bb_table = XCNEWVEC (bb_info_t, last_basic_block); | |
785 | rtx_group_next_id = 0; | |
786 | ||
e3b5732b | 787 | stores_off_frame_dead_at_return = !cfun->stdarg; |
6fb5fa3c DB |
788 | |
789 | init_alias_analysis (); | |
b8698a0f | 790 | |
6fb5fa3c DB |
791 | if (clear_alias_sets) |
792 | clear_alias_group = get_group_info (NULL); | |
793 | else | |
794 | clear_alias_group = NULL; | |
795 | } | |
796 | ||
797 | ||
798 | \f | |
799 | /*---------------------------------------------------------------------------- | |
800 | First step. | |
801 | ||
802 | Scan all of the insns. Any random ordering of the blocks is fine. | |
0d52bcc1 | 803 | Each block is scanned in forward order to accommodate cselib which |
6fb5fa3c DB |
804 | is used to remove stores with non-constant bases. |
805 | ----------------------------------------------------------------------------*/ | |
806 | ||
807 | /* Delete all of the store_info recs from INSN_INFO. */ | |
808 | ||
b8698a0f | 809 | static void |
6fb5fa3c DB |
810 | free_store_info (insn_info_t insn_info) |
811 | { | |
812 | store_info_t store_info = insn_info->store_rec; | |
813 | while (store_info) | |
814 | { | |
815 | store_info_t next = store_info->next; | |
8dd5516b | 816 | if (store_info->is_large) |
dc491a25 | 817 | BITMAP_FREE (store_info->positions_needed.large.bmap); |
6fb5fa3c DB |
818 | if (store_info->cse_base) |
819 | pool_free (cse_store_info_pool, store_info); | |
820 | else | |
821 | pool_free (rtx_store_info_pool, store_info); | |
822 | store_info = next; | |
823 | } | |
824 | ||
825 | insn_info->cannot_delete = true; | |
826 | insn_info->contains_cselib_groups = false; | |
827 | insn_info->store_rec = NULL; | |
828 | } | |
829 | ||
4deef538 AO |
830 | /* Callback for for_each_inc_dec that emits an INSN that sets DEST to |
831 | SRC + SRCOFF before insn ARG. */ | |
6fb5fa3c DB |
832 | |
833 | static int | |
4deef538 AO |
834 | emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED, |
835 | rtx op ATTRIBUTE_UNUSED, | |
836 | rtx dest, rtx src, rtx srcoff, void *arg) | |
6fb5fa3c | 837 | { |
4deef538 | 838 | rtx insn = (rtx)arg; |
b8698a0f | 839 | |
4deef538 AO |
840 | if (srcoff) |
841 | src = gen_rtx_PLUS (GET_MODE (src), src, srcoff); | |
b8698a0f | 842 | |
4deef538 AO |
843 | /* We can reuse all operands without copying, because we are about |
844 | to delete the insn that contained it. */ | |
6fb5fa3c | 845 | |
4deef538 | 846 | emit_insn_before (gen_rtx_SET (VOIDmode, dest, src), insn); |
6fb5fa3c | 847 | |
4deef538 | 848 | return -1; |
6fb5fa3c DB |
849 | } |
850 | ||
851 | /* Before we delete INSN, make sure that the auto inc/dec, if it is | |
852 | there, is split into a separate insn. */ | |
853 | ||
3f82421f | 854 | void |
6fb5fa3c DB |
855 | check_for_inc_dec (rtx insn) |
856 | { | |
857 | rtx note = find_reg_note (insn, REG_INC, NULL_RTX); | |
858 | if (note) | |
4deef538 | 859 | for_each_inc_dec (&insn, emit_inc_dec_insn_before, insn); |
6fb5fa3c DB |
860 | } |
861 | ||
862 | ||
b8698a0f | 863 | /* Delete the insn and free all of the fields inside INSN_INFO. */ |
6fb5fa3c DB |
864 | |
865 | static void | |
866 | delete_dead_store_insn (insn_info_t insn_info) | |
867 | { | |
868 | read_info_t read_info; | |
869 | ||
870 | if (!dbg_cnt (dse)) | |
871 | return; | |
872 | ||
873 | check_for_inc_dec (insn_info->insn); | |
874 | if (dump_file) | |
875 | { | |
b8698a0f | 876 | fprintf (dump_file, "Locally deleting insn %d ", |
6fb5fa3c DB |
877 | INSN_UID (insn_info->insn)); |
878 | if (insn_info->store_rec->alias_set) | |
b8698a0f | 879 | fprintf (dump_file, "alias set %d\n", |
4862826d | 880 | (int) insn_info->store_rec->alias_set); |
6fb5fa3c DB |
881 | else |
882 | fprintf (dump_file, "\n"); | |
883 | } | |
884 | ||
885 | free_store_info (insn_info); | |
886 | read_info = insn_info->read_rec; | |
b8698a0f | 887 | |
6fb5fa3c DB |
888 | while (read_info) |
889 | { | |
890 | read_info_t next = read_info->next; | |
891 | pool_free (read_info_pool, read_info); | |
892 | read_info = next; | |
893 | } | |
894 | insn_info->read_rec = NULL; | |
895 | ||
896 | delete_insn (insn_info->insn); | |
897 | locally_deleted++; | |
898 | insn_info->insn = NULL; | |
899 | ||
900 | insn_info->wild_read = false; | |
901 | } | |
902 | ||
d26c7090 ER |
903 | /* Check if EXPR can possibly escape the current function scope. */ |
904 | static bool | |
905 | can_escape (tree expr) | |
906 | { | |
907 | tree base; | |
908 | if (!expr) | |
909 | return true; | |
910 | base = get_base_address (expr); | |
911 | if (DECL_P (base) | |
912 | && !may_be_aliased (base)) | |
913 | return false; | |
914 | return true; | |
915 | } | |
6fb5fa3c DB |
916 | |
917 | /* Set the store* bitmaps offset_map_size* fields in GROUP based on | |
918 | OFFSET and WIDTH. */ | |
919 | ||
920 | static void | |
d26c7090 ER |
921 | set_usage_bits (group_info_t group, HOST_WIDE_INT offset, HOST_WIDE_INT width, |
922 | tree expr) | |
6fb5fa3c DB |
923 | { |
924 | HOST_WIDE_INT i; | |
d26c7090 | 925 | bool expr_escapes = can_escape (expr); |
8dd5516b | 926 | if (offset > -MAX_OFFSET && offset + width < MAX_OFFSET) |
6fb5fa3c DB |
927 | for (i=offset; i<offset+width; i++) |
928 | { | |
929 | bitmap store1; | |
930 | bitmap store2; | |
d26c7090 | 931 | bitmap escaped; |
6fb5fa3c DB |
932 | int ai; |
933 | if (i < 0) | |
934 | { | |
935 | store1 = group->store1_n; | |
936 | store2 = group->store2_n; | |
d26c7090 | 937 | escaped = group->escaped_n; |
6fb5fa3c DB |
938 | ai = -i; |
939 | } | |
940 | else | |
941 | { | |
942 | store1 = group->store1_p; | |
943 | store2 = group->store2_p; | |
d26c7090 | 944 | escaped = group->escaped_p; |
6fb5fa3c DB |
945 | ai = i; |
946 | } | |
b8698a0f | 947 | |
fcaa4ca4 | 948 | if (!bitmap_set_bit (store1, ai)) |
6fb5fa3c | 949 | bitmap_set_bit (store2, ai); |
b8698a0f | 950 | else |
6fb5fa3c | 951 | { |
6fb5fa3c DB |
952 | if (i < 0) |
953 | { | |
954 | if (group->offset_map_size_n < ai) | |
955 | group->offset_map_size_n = ai; | |
956 | } | |
957 | else | |
958 | { | |
959 | if (group->offset_map_size_p < ai) | |
960 | group->offset_map_size_p = ai; | |
961 | } | |
962 | } | |
d26c7090 ER |
963 | if (expr_escapes) |
964 | bitmap_set_bit (escaped, ai); | |
6fb5fa3c DB |
965 | } |
966 | } | |
967 | ||
d26c7090 ER |
968 | static void |
969 | reset_active_stores (void) | |
970 | { | |
971 | active_local_stores = NULL; | |
972 | active_local_stores_len = 0; | |
973 | } | |
6fb5fa3c | 974 | |
d26c7090 | 975 | /* Free all READ_REC of the LAST_INSN of BB_INFO. */ |
6fb5fa3c DB |
976 | |
977 | static void | |
d26c7090 | 978 | free_read_records (bb_info_t bb_info) |
6fb5fa3c DB |
979 | { |
980 | insn_info_t insn_info = bb_info->last_insn; | |
981 | read_info_t *ptr = &insn_info->read_rec; | |
6fb5fa3c DB |
982 | while (*ptr) |
983 | { | |
984 | read_info_t next = (*ptr)->next; | |
4862826d | 985 | if ((*ptr)->alias_set == 0) |
6fb5fa3c DB |
986 | { |
987 | pool_free (read_info_pool, *ptr); | |
988 | *ptr = next; | |
d26c7090 | 989 | } |
b8698a0f | 990 | else |
d26c7090 | 991 | ptr = &(*ptr)->next; |
6fb5fa3c | 992 | } |
d26c7090 ER |
993 | } |
994 | ||
995 | /* Set the BB_INFO so that the last insn is marked as a wild read. */ | |
996 | ||
997 | static void | |
998 | add_wild_read (bb_info_t bb_info) | |
999 | { | |
1000 | insn_info_t insn_info = bb_info->last_insn; | |
6fb5fa3c | 1001 | insn_info->wild_read = true; |
d26c7090 ER |
1002 | free_read_records (bb_info); |
1003 | reset_active_stores (); | |
6fb5fa3c DB |
1004 | } |
1005 | ||
d26c7090 ER |
1006 | /* Set the BB_INFO so that the last insn is marked as a wild read of |
1007 | non-frame locations. */ | |
1008 | ||
1009 | static void | |
1010 | add_non_frame_wild_read (bb_info_t bb_info) | |
1011 | { | |
1012 | insn_info_t insn_info = bb_info->last_insn; | |
1013 | insn_info->non_frame_wild_read = true; | |
1014 | free_read_records (bb_info); | |
1015 | reset_active_stores (); | |
1016 | } | |
6fb5fa3c | 1017 | |
50f0f366 EB |
1018 | /* Return true if X is a constant or one of the registers that behave |
1019 | as a constant over the life of a function. This is equivalent to | |
1020 | !rtx_varies_p for memory addresses. */ | |
6fb5fa3c DB |
1021 | |
1022 | static bool | |
1023 | const_or_frame_p (rtx x) | |
1024 | { | |
1025 | switch (GET_CODE (x)) | |
1026 | { | |
6fb5fa3c DB |
1027 | case CONST: |
1028 | case CONST_INT: | |
1029 | case CONST_DOUBLE: | |
1030 | case CONST_VECTOR: | |
1031 | case SYMBOL_REF: | |
1032 | case LABEL_REF: | |
1033 | return true; | |
1034 | ||
1035 | case REG: | |
1036 | /* Note that we have to test for the actual rtx used for the frame | |
1037 | and arg pointers and not just the register number in case we have | |
1038 | eliminated the frame and/or arg pointer and are using it | |
1039 | for pseudos. */ | |
1040 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx | |
1041 | /* The arg pointer varies if it is not a fixed register. */ | |
1042 | || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
1043 | || x == pic_offset_table_rtx) | |
1044 | return true; | |
1045 | return false; | |
1046 | ||
1047 | default: | |
1048 | return false; | |
1049 | } | |
1050 | } | |
1051 | ||
b8698a0f L |
1052 | /* Take all reasonable action to put the address of MEM into the form |
1053 | that we can do analysis on. | |
6fb5fa3c DB |
1054 | |
1055 | The gold standard is to get the address into the form: address + | |
1056 | OFFSET where address is something that rtx_varies_p considers a | |
1057 | constant. When we can get the address in this form, we can do | |
1058 | global analysis on it. Note that for constant bases, address is | |
1059 | not actually returned, only the group_id. The address can be | |
1060 | obtained from that. | |
1061 | ||
1062 | If that fails, we try cselib to get a value we can at least use | |
b8698a0f L |
1063 | locally. If that fails we return false. |
1064 | ||
6fb5fa3c DB |
1065 | The GROUP_ID is set to -1 for cselib bases and the index of the |
1066 | group for non_varying bases. | |
1067 | ||
1068 | FOR_READ is true if this is a mem read and false if not. */ | |
1069 | ||
1070 | static bool | |
1071 | canon_address (rtx mem, | |
4862826d | 1072 | alias_set_type *alias_set_out, |
6fb5fa3c | 1073 | int *group_id, |
b8698a0f | 1074 | HOST_WIDE_INT *offset, |
6fb5fa3c DB |
1075 | cselib_val **base) |
1076 | { | |
d4ebfa65 BE |
1077 | enum machine_mode address_mode |
1078 | = targetm.addr_space.address_mode (MEM_ADDR_SPACE (mem)); | |
6fb5fa3c DB |
1079 | rtx mem_address = XEXP (mem, 0); |
1080 | rtx expanded_address, address; | |
403c7520 JJ |
1081 | int expanded; |
1082 | ||
6fb5fa3c DB |
1083 | /* Make sure that cselib is has initialized all of the operands of |
1084 | the address before asking it to do the subst. */ | |
1085 | ||
1086 | if (clear_alias_sets) | |
1087 | { | |
1088 | /* If this is a spill, do not do any further processing. */ | |
4862826d | 1089 | alias_set_type alias_set = MEM_ALIAS_SET (mem); |
6fb5fa3c | 1090 | if (dump_file) |
4862826d | 1091 | fprintf (dump_file, "found alias set %d\n", (int) alias_set); |
6fb5fa3c DB |
1092 | if (bitmap_bit_p (clear_alias_sets, alias_set)) |
1093 | { | |
b8698a0f | 1094 | struct clear_alias_mode_holder *entry |
6fb5fa3c DB |
1095 | = clear_alias_set_lookup (alias_set); |
1096 | ||
1097 | /* If the modes do not match, we cannot process this set. */ | |
1098 | if (entry->mode != GET_MODE (mem)) | |
1099 | { | |
1100 | if (dump_file) | |
b8698a0f L |
1101 | fprintf (dump_file, |
1102 | "disqualifying alias set %d, (%s) != (%s)\n", | |
1103 | (int) alias_set, GET_MODE_NAME (entry->mode), | |
6fb5fa3c | 1104 | GET_MODE_NAME (GET_MODE (mem))); |
b8698a0f | 1105 | |
6fb5fa3c DB |
1106 | bitmap_set_bit (disqualified_clear_alias_sets, alias_set); |
1107 | return false; | |
1108 | } | |
1109 | ||
1110 | *alias_set_out = alias_set; | |
1111 | *group_id = clear_alias_group->id; | |
1112 | return true; | |
1113 | } | |
1114 | } | |
1115 | ||
1116 | *alias_set_out = 0; | |
1117 | ||
4deef538 | 1118 | cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem)); |
6fb5fa3c DB |
1119 | |
1120 | if (dump_file) | |
1121 | { | |
1122 | fprintf (dump_file, " mem: "); | |
1123 | print_inline_rtx (dump_file, mem_address, 0); | |
1124 | fprintf (dump_file, "\n"); | |
1125 | } | |
1126 | ||
403c7520 JJ |
1127 | /* First see if just canon_rtx (mem_address) is const or frame, |
1128 | if not, try cselib_expand_value_rtx and call canon_rtx on that. */ | |
1129 | address = NULL_RTX; | |
1130 | for (expanded = 0; expanded < 2; expanded++) | |
1131 | { | |
1132 | if (expanded) | |
1133 | { | |
1134 | /* Use cselib to replace all of the reg references with the full | |
b8698a0f | 1135 | expression. This will take care of the case where we have |
6fb5fa3c | 1136 | |
403c7520 JJ |
1137 | r_x = base + offset; |
1138 | val = *r_x; | |
b8698a0f L |
1139 | |
1140 | by making it into | |
6fb5fa3c | 1141 | |
403c7520 | 1142 | val = *(base + offset); */ |
6fb5fa3c | 1143 | |
403c7520 JJ |
1144 | expanded_address = cselib_expand_value_rtx (mem_address, |
1145 | scratch, 5); | |
6fb5fa3c | 1146 | |
403c7520 JJ |
1147 | /* If this fails, just go with the address from first |
1148 | iteration. */ | |
1149 | if (!expanded_address) | |
1150 | break; | |
1151 | } | |
1152 | else | |
1153 | expanded_address = mem_address; | |
6fb5fa3c | 1154 | |
403c7520 JJ |
1155 | /* Split the address into canonical BASE + OFFSET terms. */ |
1156 | address = canon_rtx (expanded_address); | |
6fb5fa3c | 1157 | |
403c7520 | 1158 | *offset = 0; |
6fb5fa3c | 1159 | |
403c7520 JJ |
1160 | if (dump_file) |
1161 | { | |
1162 | if (expanded) | |
1163 | { | |
1164 | fprintf (dump_file, "\n after cselib_expand address: "); | |
1165 | print_inline_rtx (dump_file, expanded_address, 0); | |
1166 | fprintf (dump_file, "\n"); | |
1167 | } | |
6fb5fa3c | 1168 | |
403c7520 JJ |
1169 | fprintf (dump_file, "\n after canon_rtx address: "); |
1170 | print_inline_rtx (dump_file, address, 0); | |
1171 | fprintf (dump_file, "\n"); | |
1172 | } | |
6fb5fa3c | 1173 | |
403c7520 JJ |
1174 | if (GET_CODE (address) == CONST) |
1175 | address = XEXP (address, 0); | |
6fb5fa3c | 1176 | |
403c7520 JJ |
1177 | if (GET_CODE (address) == PLUS |
1178 | && CONST_INT_P (XEXP (address, 1))) | |
1179 | { | |
1180 | *offset = INTVAL (XEXP (address, 1)); | |
1181 | address = XEXP (address, 0); | |
1182 | } | |
6fb5fa3c | 1183 | |
09e881c9 BE |
1184 | if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem)) |
1185 | && const_or_frame_p (address)) | |
6fb5fa3c | 1186 | { |
403c7520 JJ |
1187 | group_info_t group = get_group_info (address); |
1188 | ||
6fb5fa3c | 1189 | if (dump_file) |
403c7520 JJ |
1190 | fprintf (dump_file, " gid=%d offset=%d \n", |
1191 | group->id, (int)*offset); | |
1192 | *base = NULL; | |
1193 | *group_id = group->id; | |
1194 | return true; | |
6fb5fa3c | 1195 | } |
403c7520 JJ |
1196 | } |
1197 | ||
4deef538 | 1198 | *base = cselib_lookup (address, address_mode, true, GET_MODE (mem)); |
403c7520 JJ |
1199 | *group_id = -1; |
1200 | ||
1201 | if (*base == NULL) | |
1202 | { | |
6fb5fa3c | 1203 | if (dump_file) |
403c7520 JJ |
1204 | fprintf (dump_file, " no cselib val - should be a wild read.\n"); |
1205 | return false; | |
6fb5fa3c | 1206 | } |
403c7520 | 1207 | if (dump_file) |
5440c0e7 AO |
1208 | fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n", |
1209 | (*base)->uid, (*base)->hash, (int)*offset); | |
6fb5fa3c DB |
1210 | return true; |
1211 | } | |
1212 | ||
1213 | ||
1214 | /* Clear the rhs field from the active_local_stores array. */ | |
1215 | ||
1216 | static void | |
1217 | clear_rhs_from_active_local_stores (void) | |
1218 | { | |
1219 | insn_info_t ptr = active_local_stores; | |
1220 | ||
1221 | while (ptr) | |
1222 | { | |
1223 | store_info_t store_info = ptr->store_rec; | |
1224 | /* Skip the clobbers. */ | |
1225 | while (!store_info->is_set) | |
1226 | store_info = store_info->next; | |
1227 | ||
1228 | store_info->rhs = NULL; | |
8dd5516b | 1229 | store_info->const_rhs = NULL; |
6fb5fa3c DB |
1230 | |
1231 | ptr = ptr->next_local_store; | |
1232 | } | |
1233 | } | |
1234 | ||
1235 | ||
8dd5516b JJ |
1236 | /* Mark byte POS bytes from the beginning of store S_INFO as unneeded. */ |
1237 | ||
1238 | static inline void | |
1239 | set_position_unneeded (store_info_t s_info, int pos) | |
1240 | { | |
1241 | if (__builtin_expect (s_info->is_large, false)) | |
1242 | { | |
fcaa4ca4 NF |
1243 | if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos)) |
1244 | s_info->positions_needed.large.count++; | |
8dd5516b JJ |
1245 | } |
1246 | else | |
1247 | s_info->positions_needed.small_bitmask | |
1248 | &= ~(((unsigned HOST_WIDE_INT) 1) << pos); | |
1249 | } | |
1250 | ||
1251 | /* Mark the whole store S_INFO as unneeded. */ | |
1252 | ||
1253 | static inline void | |
1254 | set_all_positions_unneeded (store_info_t s_info) | |
1255 | { | |
1256 | if (__builtin_expect (s_info->is_large, false)) | |
1257 | { | |
1258 | int pos, end = s_info->end - s_info->begin; | |
1259 | for (pos = 0; pos < end; pos++) | |
dc491a25 | 1260 | bitmap_set_bit (s_info->positions_needed.large.bmap, pos); |
8dd5516b JJ |
1261 | s_info->positions_needed.large.count = end; |
1262 | } | |
1263 | else | |
1264 | s_info->positions_needed.small_bitmask = (unsigned HOST_WIDE_INT) 0; | |
1265 | } | |
1266 | ||
1267 | /* Return TRUE if any bytes from S_INFO store are needed. */ | |
1268 | ||
1269 | static inline bool | |
1270 | any_positions_needed_p (store_info_t s_info) | |
1271 | { | |
1272 | if (__builtin_expect (s_info->is_large, false)) | |
1273 | return (s_info->positions_needed.large.count | |
1274 | < s_info->end - s_info->begin); | |
1275 | else | |
1276 | return (s_info->positions_needed.small_bitmask | |
1277 | != (unsigned HOST_WIDE_INT) 0); | |
1278 | } | |
1279 | ||
1280 | /* Return TRUE if all bytes START through START+WIDTH-1 from S_INFO | |
1281 | store are needed. */ | |
1282 | ||
1283 | static inline bool | |
1284 | all_positions_needed_p (store_info_t s_info, int start, int width) | |
1285 | { | |
1286 | if (__builtin_expect (s_info->is_large, false)) | |
1287 | { | |
1288 | int end = start + width; | |
1289 | while (start < end) | |
dc491a25 | 1290 | if (bitmap_bit_p (s_info->positions_needed.large.bmap, start++)) |
8dd5516b JJ |
1291 | return false; |
1292 | return true; | |
1293 | } | |
1294 | else | |
1295 | { | |
1296 | unsigned HOST_WIDE_INT mask = lowpart_bitmask (width) << start; | |
1297 | return (s_info->positions_needed.small_bitmask & mask) == mask; | |
1298 | } | |
1299 | } | |
1300 | ||
1301 | ||
1302 | static rtx get_stored_val (store_info_t, enum machine_mode, HOST_WIDE_INT, | |
1303 | HOST_WIDE_INT, basic_block, bool); | |
1304 | ||
1305 | ||
6fb5fa3c DB |
1306 | /* BODY is an instruction pattern that belongs to INSN. Return 1 if |
1307 | there is a candidate store, after adding it to the appropriate | |
1308 | local store group if so. */ | |
1309 | ||
1310 | static int | |
1311 | record_store (rtx body, bb_info_t bb_info) | |
1312 | { | |
6216f94e | 1313 | rtx mem, rhs, const_rhs, mem_addr; |
6fb5fa3c DB |
1314 | HOST_WIDE_INT offset = 0; |
1315 | HOST_WIDE_INT width = 0; | |
4862826d | 1316 | alias_set_type spill_alias_set; |
6fb5fa3c DB |
1317 | insn_info_t insn_info = bb_info->last_insn; |
1318 | store_info_t store_info = NULL; | |
1319 | int group_id; | |
1320 | cselib_val *base = NULL; | |
8dd5516b | 1321 | insn_info_t ptr, last, redundant_reason; |
6fb5fa3c DB |
1322 | bool store_is_unused; |
1323 | ||
1324 | if (GET_CODE (body) != SET && GET_CODE (body) != CLOBBER) | |
1325 | return 0; | |
1326 | ||
8dd5516b JJ |
1327 | mem = SET_DEST (body); |
1328 | ||
6fb5fa3c DB |
1329 | /* If this is not used, then this cannot be used to keep the insn |
1330 | from being deleted. On the other hand, it does provide something | |
1331 | that can be used to prove that another store is dead. */ | |
1332 | store_is_unused | |
8dd5516b | 1333 | = (find_reg_note (insn_info->insn, REG_UNUSED, mem) != NULL); |
6fb5fa3c DB |
1334 | |
1335 | /* Check whether that value is a suitable memory location. */ | |
6fb5fa3c DB |
1336 | if (!MEM_P (mem)) |
1337 | { | |
1338 | /* If the set or clobber is unused, then it does not effect our | |
1339 | ability to get rid of the entire insn. */ | |
1340 | if (!store_is_unused) | |
1341 | insn_info->cannot_delete = true; | |
1342 | return 0; | |
1343 | } | |
1344 | ||
1345 | /* At this point we know mem is a mem. */ | |
1346 | if (GET_MODE (mem) == BLKmode) | |
1347 | { | |
1348 | if (GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
1349 | { | |
b8698a0f | 1350 | if (dump_file) |
6fb5fa3c DB |
1351 | fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n"); |
1352 | add_wild_read (bb_info); | |
1353 | insn_info->cannot_delete = true; | |
8dd5516b | 1354 | return 0; |
6fb5fa3c | 1355 | } |
8dd5516b JJ |
1356 | /* Handle (set (mem:BLK (addr) [... S36 ...]) (const_int 0)) |
1357 | as memset (addr, 0, 36); */ | |
1358 | else if (!MEM_SIZE (mem) | |
1359 | || !CONST_INT_P (MEM_SIZE (mem)) | |
1360 | || GET_CODE (body) != SET | |
1361 | || INTVAL (MEM_SIZE (mem)) <= 0 | |
1362 | || INTVAL (MEM_SIZE (mem)) > MAX_OFFSET | |
1363 | || !CONST_INT_P (SET_SRC (body))) | |
6fb5fa3c | 1364 | { |
8dd5516b JJ |
1365 | if (!store_is_unused) |
1366 | { | |
1367 | /* If the set or clobber is unused, then it does not effect our | |
1368 | ability to get rid of the entire insn. */ | |
1369 | insn_info->cannot_delete = true; | |
1370 | clear_rhs_from_active_local_stores (); | |
1371 | } | |
1372 | return 0; | |
6fb5fa3c | 1373 | } |
6fb5fa3c DB |
1374 | } |
1375 | ||
1376 | /* We can still process a volatile mem, we just cannot delete it. */ | |
1377 | if (MEM_VOLATILE_P (mem)) | |
8dd5516b | 1378 | insn_info->cannot_delete = true; |
6fb5fa3c DB |
1379 | |
1380 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
1381 | { | |
1382 | clear_rhs_from_active_local_stores (); | |
1383 | return 0; | |
1384 | } | |
1385 | ||
8dd5516b JJ |
1386 | if (GET_MODE (mem) == BLKmode) |
1387 | width = INTVAL (MEM_SIZE (mem)); | |
1388 | else | |
1389 | { | |
1390 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
1391 | gcc_assert ((unsigned) width <= HOST_BITS_PER_WIDE_INT); | |
1392 | } | |
6fb5fa3c DB |
1393 | |
1394 | if (spill_alias_set) | |
1395 | { | |
1396 | bitmap store1 = clear_alias_group->store1_p; | |
1397 | bitmap store2 = clear_alias_group->store2_p; | |
8dd5516b JJ |
1398 | |
1399 | gcc_assert (GET_MODE (mem) != BLKmode); | |
b8698a0f | 1400 | |
fcaa4ca4 | 1401 | if (!bitmap_set_bit (store1, spill_alias_set)) |
6fb5fa3c | 1402 | bitmap_set_bit (store2, spill_alias_set); |
b8698a0f | 1403 | |
6fb5fa3c DB |
1404 | if (clear_alias_group->offset_map_size_p < spill_alias_set) |
1405 | clear_alias_group->offset_map_size_p = spill_alias_set; | |
b8698a0f | 1406 | |
f883e0a7 | 1407 | store_info = (store_info_t) pool_alloc (rtx_store_info_pool); |
6fb5fa3c DB |
1408 | |
1409 | if (dump_file) | |
1410 | fprintf (dump_file, " processing spill store %d(%s)\n", | |
4862826d | 1411 | (int) spill_alias_set, GET_MODE_NAME (GET_MODE (mem))); |
6fb5fa3c DB |
1412 | } |
1413 | else if (group_id >= 0) | |
1414 | { | |
1415 | /* In the restrictive case where the base is a constant or the | |
1416 | frame pointer we can do global analysis. */ | |
b8698a0f L |
1417 | |
1418 | group_info_t group | |
6fb5fa3c | 1419 | = VEC_index (group_info_t, rtx_group_vec, group_id); |
d26c7090 | 1420 | tree expr = MEM_EXPR (mem); |
b8698a0f | 1421 | |
f883e0a7 | 1422 | store_info = (store_info_t) pool_alloc (rtx_store_info_pool); |
d26c7090 | 1423 | set_usage_bits (group, offset, width, expr); |
6fb5fa3c DB |
1424 | |
1425 | if (dump_file) | |
1426 | fprintf (dump_file, " processing const base store gid=%d[%d..%d)\n", | |
1427 | group_id, (int)offset, (int)(offset+width)); | |
1428 | } | |
1429 | else | |
1430 | { | |
50f0f366 EB |
1431 | rtx base_term = find_base_term (XEXP (mem, 0)); |
1432 | if (!base_term | |
1433 | || (GET_CODE (base_term) == ADDRESS | |
1434 | && GET_MODE (base_term) == Pmode | |
1435 | && XEXP (base_term, 0) == stack_pointer_rtx)) | |
1436 | insn_info->stack_pointer_based = true; | |
6fb5fa3c | 1437 | insn_info->contains_cselib_groups = true; |
50f0f366 | 1438 | |
f883e0a7 | 1439 | store_info = (store_info_t) pool_alloc (cse_store_info_pool); |
6fb5fa3c DB |
1440 | group_id = -1; |
1441 | ||
1442 | if (dump_file) | |
1443 | fprintf (dump_file, " processing cselib store [%d..%d)\n", | |
1444 | (int)offset, (int)(offset+width)); | |
1445 | } | |
1446 | ||
8dd5516b JJ |
1447 | const_rhs = rhs = NULL_RTX; |
1448 | if (GET_CODE (body) == SET | |
1449 | /* No place to keep the value after ra. */ | |
1450 | && !reload_completed | |
1451 | && (REG_P (SET_SRC (body)) | |
1452 | || GET_CODE (SET_SRC (body)) == SUBREG | |
1453 | || CONSTANT_P (SET_SRC (body))) | |
1454 | && !MEM_VOLATILE_P (mem) | |
1455 | /* Sometimes the store and reload is used for truncation and | |
1456 | rounding. */ | |
1457 | && !(FLOAT_MODE_P (GET_MODE (mem)) && (flag_float_store))) | |
1458 | { | |
1459 | rhs = SET_SRC (body); | |
1460 | if (CONSTANT_P (rhs)) | |
1461 | const_rhs = rhs; | |
1462 | else if (body == PATTERN (insn_info->insn)) | |
1463 | { | |
1464 | rtx tem = find_reg_note (insn_info->insn, REG_EQUAL, NULL_RTX); | |
1465 | if (tem && CONSTANT_P (XEXP (tem, 0))) | |
1466 | const_rhs = XEXP (tem, 0); | |
1467 | } | |
1468 | if (const_rhs == NULL_RTX && REG_P (rhs)) | |
1469 | { | |
1470 | rtx tem = cselib_expand_value_rtx (rhs, scratch, 5); | |
1471 | ||
1472 | if (tem && CONSTANT_P (tem)) | |
1473 | const_rhs = tem; | |
1474 | } | |
1475 | } | |
1476 | ||
6fb5fa3c DB |
1477 | /* Check to see if this stores causes some other stores to be |
1478 | dead. */ | |
1479 | ptr = active_local_stores; | |
1480 | last = NULL; | |
8dd5516b | 1481 | redundant_reason = NULL; |
6216f94e JJ |
1482 | mem = canon_rtx (mem); |
1483 | /* For alias_set != 0 canon_true_dependence should be never called. */ | |
1484 | if (spill_alias_set) | |
1485 | mem_addr = NULL_RTX; | |
1486 | else | |
1487 | { | |
1488 | if (group_id < 0) | |
1489 | mem_addr = base->val_rtx; | |
1490 | else | |
1491 | { | |
1492 | group_info_t group | |
1493 | = VEC_index (group_info_t, rtx_group_vec, group_id); | |
1494 | mem_addr = group->canon_base_addr; | |
1495 | } | |
1496 | if (offset) | |
1497 | mem_addr = plus_constant (mem_addr, offset); | |
1498 | } | |
6fb5fa3c DB |
1499 | |
1500 | while (ptr) | |
1501 | { | |
1502 | insn_info_t next = ptr->next_local_store; | |
1503 | store_info_t s_info = ptr->store_rec; | |
60564289 | 1504 | bool del = true; |
6fb5fa3c DB |
1505 | |
1506 | /* Skip the clobbers. We delete the active insn if this insn | |
6ed3da00 | 1507 | shadows the set. To have been put on the active list, it |
6fb5fa3c DB |
1508 | has exactly on set. */ |
1509 | while (!s_info->is_set) | |
1510 | s_info = s_info->next; | |
1511 | ||
1512 | if (s_info->alias_set != spill_alias_set) | |
60564289 | 1513 | del = false; |
6fb5fa3c DB |
1514 | else if (s_info->alias_set) |
1515 | { | |
b8698a0f | 1516 | struct clear_alias_mode_holder *entry |
6fb5fa3c DB |
1517 | = clear_alias_set_lookup (s_info->alias_set); |
1518 | /* Generally, spills cannot be processed if and of the | |
1519 | references to the slot have a different mode. But if | |
1520 | we are in the same block and mode is exactly the same | |
1521 | between this store and one before in the same block, | |
1522 | we can still delete it. */ | |
1523 | if ((GET_MODE (mem) == GET_MODE (s_info->mem)) | |
1524 | && (GET_MODE (mem) == entry->mode)) | |
1525 | { | |
60564289 | 1526 | del = true; |
8dd5516b | 1527 | set_all_positions_unneeded (s_info); |
6fb5fa3c DB |
1528 | } |
1529 | if (dump_file) | |
1530 | fprintf (dump_file, " trying spill store in insn=%d alias_set=%d\n", | |
4862826d | 1531 | INSN_UID (ptr->insn), (int) s_info->alias_set); |
6fb5fa3c | 1532 | } |
b8698a0f | 1533 | else if ((s_info->group_id == group_id) |
6fb5fa3c DB |
1534 | && (s_info->cse_base == base)) |
1535 | { | |
1536 | HOST_WIDE_INT i; | |
1537 | if (dump_file) | |
1538 | fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n", | |
b8698a0f | 1539 | INSN_UID (ptr->insn), s_info->group_id, |
6fb5fa3c | 1540 | (int)s_info->begin, (int)s_info->end); |
8dd5516b JJ |
1541 | |
1542 | /* Even if PTR won't be eliminated as unneeded, if both | |
1543 | PTR and this insn store the same constant value, we might | |
1544 | eliminate this insn instead. */ | |
1545 | if (s_info->const_rhs | |
1546 | && const_rhs | |
1547 | && offset >= s_info->begin | |
1548 | && offset + width <= s_info->end | |
1549 | && all_positions_needed_p (s_info, offset - s_info->begin, | |
1550 | width)) | |
1551 | { | |
1552 | if (GET_MODE (mem) == BLKmode) | |
1553 | { | |
1554 | if (GET_MODE (s_info->mem) == BLKmode | |
1555 | && s_info->const_rhs == const_rhs) | |
1556 | redundant_reason = ptr; | |
1557 | } | |
1558 | else if (s_info->const_rhs == const0_rtx | |
1559 | && const_rhs == const0_rtx) | |
1560 | redundant_reason = ptr; | |
1561 | else | |
1562 | { | |
1563 | rtx val; | |
1564 | start_sequence (); | |
1565 | val = get_stored_val (s_info, GET_MODE (mem), | |
1566 | offset, offset + width, | |
1567 | BLOCK_FOR_INSN (insn_info->insn), | |
1568 | true); | |
1569 | if (get_insns () != NULL) | |
1570 | val = NULL_RTX; | |
1571 | end_sequence (); | |
1572 | if (val && rtx_equal_p (val, const_rhs)) | |
1573 | redundant_reason = ptr; | |
1574 | } | |
1575 | } | |
1576 | ||
1577 | for (i = MAX (offset, s_info->begin); | |
1578 | i < offset + width && i < s_info->end; | |
1579 | i++) | |
1580 | set_position_unneeded (s_info, i - s_info->begin); | |
6fb5fa3c DB |
1581 | } |
1582 | else if (s_info->rhs) | |
1583 | /* Need to see if it is possible for this store to overwrite | |
1584 | the value of store_info. If it is, set the rhs to NULL to | |
1585 | keep it from being used to remove a load. */ | |
1586 | { | |
b8698a0f | 1587 | if (canon_true_dependence (s_info->mem, |
6fb5fa3c DB |
1588 | GET_MODE (s_info->mem), |
1589 | s_info->mem_addr, | |
6216f94e | 1590 | mem, mem_addr, rtx_varies_p)) |
8dd5516b JJ |
1591 | { |
1592 | s_info->rhs = NULL; | |
1593 | s_info->const_rhs = NULL; | |
1594 | } | |
6fb5fa3c | 1595 | } |
6216f94e | 1596 | |
6fb5fa3c DB |
1597 | /* An insn can be deleted if every position of every one of |
1598 | its s_infos is zero. */ | |
1b6fa860 | 1599 | if (any_positions_needed_p (s_info)) |
60564289 | 1600 | del = false; |
8dd5516b | 1601 | |
60564289 | 1602 | if (del) |
6fb5fa3c DB |
1603 | { |
1604 | insn_info_t insn_to_delete = ptr; | |
b8698a0f | 1605 | |
dabd47e7 | 1606 | active_local_stores_len--; |
6fb5fa3c DB |
1607 | if (last) |
1608 | last->next_local_store = ptr->next_local_store; | |
1609 | else | |
1610 | active_local_stores = ptr->next_local_store; | |
b8698a0f | 1611 | |
1b6fa860 JJ |
1612 | if (!insn_to_delete->cannot_delete) |
1613 | delete_dead_store_insn (insn_to_delete); | |
6fb5fa3c DB |
1614 | } |
1615 | else | |
1616 | last = ptr; | |
b8698a0f | 1617 | |
6fb5fa3c DB |
1618 | ptr = next; |
1619 | } | |
b8698a0f | 1620 | |
6fb5fa3c DB |
1621 | /* Finish filling in the store_info. */ |
1622 | store_info->next = insn_info->store_rec; | |
1623 | insn_info->store_rec = store_info; | |
6216f94e | 1624 | store_info->mem = mem; |
6fb5fa3c | 1625 | store_info->alias_set = spill_alias_set; |
6216f94e | 1626 | store_info->mem_addr = mem_addr; |
6fb5fa3c | 1627 | store_info->cse_base = base; |
8dd5516b JJ |
1628 | if (width > HOST_BITS_PER_WIDE_INT) |
1629 | { | |
1630 | store_info->is_large = true; | |
1631 | store_info->positions_needed.large.count = 0; | |
dc491a25 | 1632 | store_info->positions_needed.large.bmap = BITMAP_ALLOC (NULL); |
8dd5516b JJ |
1633 | } |
1634 | else | |
1635 | { | |
1636 | store_info->is_large = false; | |
1637 | store_info->positions_needed.small_bitmask = lowpart_bitmask (width); | |
1638 | } | |
6fb5fa3c DB |
1639 | store_info->group_id = group_id; |
1640 | store_info->begin = offset; | |
1641 | store_info->end = offset + width; | |
1642 | store_info->is_set = GET_CODE (body) == SET; | |
8dd5516b JJ |
1643 | store_info->rhs = rhs; |
1644 | store_info->const_rhs = const_rhs; | |
1645 | store_info->redundant_reason = redundant_reason; | |
6fb5fa3c | 1646 | |
6fb5fa3c DB |
1647 | /* If this is a clobber, we return 0. We will only be able to |
1648 | delete this insn if there is only one store USED store, but we | |
1649 | can use the clobber to delete other stores earlier. */ | |
1650 | return store_info->is_set ? 1 : 0; | |
1651 | } | |
1652 | ||
1653 | ||
1654 | static void | |
1655 | dump_insn_info (const char * start, insn_info_t insn_info) | |
1656 | { | |
b8698a0f | 1657 | fprintf (dump_file, "%s insn=%d %s\n", start, |
6fb5fa3c DB |
1658 | INSN_UID (insn_info->insn), |
1659 | insn_info->store_rec ? "has store" : "naked"); | |
1660 | } | |
1661 | ||
1662 | ||
8660aaae EC |
1663 | /* If the modes are different and the value's source and target do not |
1664 | line up, we need to extract the value from lower part of the rhs of | |
1665 | the store, shift it, and then put it into a form that can be shoved | |
1666 | into the read_insn. This function generates a right SHIFT of a | |
1667 | value that is at least ACCESS_SIZE bytes wide of READ_MODE. The | |
1668 | shift sequence is returned or NULL if we failed to find a | |
1669 | shift. */ | |
1670 | ||
1671 | static rtx | |
18b526e8 | 1672 | find_shift_sequence (int access_size, |
8660aaae | 1673 | store_info_t store_info, |
8dd5516b JJ |
1674 | enum machine_mode read_mode, |
1675 | int shift, bool speed, bool require_cst) | |
8660aaae EC |
1676 | { |
1677 | enum machine_mode store_mode = GET_MODE (store_info->mem); | |
18b526e8 RS |
1678 | enum machine_mode new_mode; |
1679 | rtx read_reg = NULL; | |
8660aaae EC |
1680 | |
1681 | /* Some machines like the x86 have shift insns for each size of | |
1682 | operand. Other machines like the ppc or the ia-64 may only have | |
1683 | shift insns that shift values within 32 or 64 bit registers. | |
1684 | This loop tries to find the smallest shift insn that will right | |
1685 | justify the value we want to read but is available in one insn on | |
1686 | the machine. */ | |
1687 | ||
18b526e8 RS |
1688 | for (new_mode = smallest_mode_for_size (access_size * BITS_PER_UNIT, |
1689 | MODE_INT); | |
1690 | GET_MODE_BITSIZE (new_mode) <= BITS_PER_WORD; | |
1691 | new_mode = GET_MODE_WIDER_MODE (new_mode)) | |
8660aaae | 1692 | { |
18b526e8 | 1693 | rtx target, new_reg, shift_seq, insn, new_lhs; |
d898d29b | 1694 | int cost; |
348eea5f | 1695 | |
72a2609f JJ |
1696 | /* If a constant was stored into memory, try to simplify it here, |
1697 | otherwise the cost of the shift might preclude this optimization | |
1698 | e.g. at -Os, even when no actual shift will be needed. */ | |
8dd5516b | 1699 | if (store_info->const_rhs) |
72a2609f JJ |
1700 | { |
1701 | unsigned int byte = subreg_lowpart_offset (new_mode, store_mode); | |
8dd5516b JJ |
1702 | rtx ret = simplify_subreg (new_mode, store_info->const_rhs, |
1703 | store_mode, byte); | |
72a2609f JJ |
1704 | if (ret && CONSTANT_P (ret)) |
1705 | { | |
1706 | ret = simplify_const_binary_operation (LSHIFTRT, new_mode, | |
1707 | ret, GEN_INT (shift)); | |
1708 | if (ret && CONSTANT_P (ret)) | |
1709 | { | |
1710 | byte = subreg_lowpart_offset (read_mode, new_mode); | |
1711 | ret = simplify_subreg (read_mode, ret, new_mode, byte); | |
1712 | if (ret && CONSTANT_P (ret) | |
1713 | && rtx_cost (ret, SET, speed) <= COSTS_N_INSNS (1)) | |
1714 | return ret; | |
1715 | } | |
1716 | } | |
1717 | } | |
1718 | ||
8dd5516b JJ |
1719 | if (require_cst) |
1720 | return NULL_RTX; | |
1721 | ||
18b526e8 RS |
1722 | /* Try a wider mode if truncating the store mode to NEW_MODE |
1723 | requires a real instruction. */ | |
1724 | if (GET_MODE_BITSIZE (new_mode) < GET_MODE_BITSIZE (store_mode) | |
1725 | && !TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (new_mode), | |
348eea5f RS |
1726 | GET_MODE_BITSIZE (store_mode))) |
1727 | continue; | |
1728 | ||
18b526e8 RS |
1729 | /* Also try a wider mode if the necessary punning is either not |
1730 | desirable or not possible. */ | |
1731 | if (!CONSTANT_P (store_info->rhs) | |
1732 | && !MODES_TIEABLE_P (new_mode, store_mode)) | |
1733 | continue; | |
18b526e8 | 1734 | |
348eea5f | 1735 | new_reg = gen_reg_rtx (new_mode); |
8660aaae EC |
1736 | |
1737 | start_sequence (); | |
1738 | ||
1739 | /* In theory we could also check for an ashr. Ian Taylor knows | |
1740 | of one dsp where the cost of these two was not the same. But | |
1741 | this really is a rare case anyway. */ | |
1742 | target = expand_binop (new_mode, lshr_optab, new_reg, | |
1743 | GEN_INT (shift), new_reg, 1, OPTAB_DIRECT); | |
1744 | ||
c6f3019a RS |
1745 | shift_seq = get_insns (); |
1746 | end_sequence (); | |
8660aaae | 1747 | |
c6f3019a RS |
1748 | if (target != new_reg || shift_seq == NULL) |
1749 | continue; | |
1750 | ||
1751 | cost = 0; | |
1752 | for (insn = shift_seq; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
1753 | if (INSN_P (insn)) | |
f40751dd | 1754 | cost += insn_rtx_cost (PATTERN (insn), speed); |
c6f3019a RS |
1755 | |
1756 | /* The computation up to here is essentially independent | |
1757 | of the arguments and could be precomputed. It may | |
1758 | not be worth doing so. We could precompute if | |
1759 | worthwhile or at least cache the results. The result | |
06acf7d0 RS |
1760 | technically depends on both SHIFT and ACCESS_SIZE, |
1761 | but in practice the answer will depend only on ACCESS_SIZE. */ | |
c6f3019a RS |
1762 | |
1763 | if (cost > COSTS_N_INSNS (1)) | |
1764 | continue; | |
1765 | ||
d898d29b JJ |
1766 | new_lhs = extract_low_bits (new_mode, store_mode, |
1767 | copy_rtx (store_info->rhs)); | |
1768 | if (new_lhs == NULL_RTX) | |
1769 | continue; | |
1770 | ||
c6f3019a RS |
1771 | /* We found an acceptable shift. Generate a move to |
1772 | take the value from the store and put it into the | |
1773 | shift pseudo, then shift it, then generate another | |
1774 | move to put in into the target of the read. */ | |
18b526e8 | 1775 | emit_move_insn (new_reg, new_lhs); |
c6f3019a | 1776 | emit_insn (shift_seq); |
18b526e8 | 1777 | read_reg = extract_low_bits (read_mode, new_mode, new_reg); |
c6f3019a | 1778 | break; |
8660aaae EC |
1779 | } |
1780 | ||
18b526e8 | 1781 | return read_reg; |
8660aaae EC |
1782 | } |
1783 | ||
1784 | ||
02b47899 KZ |
1785 | /* Call back for note_stores to find the hard regs set or clobbered by |
1786 | insn. Data is a bitmap of the hardregs set so far. */ | |
1787 | ||
1788 | static void | |
1789 | look_for_hardregs (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) | |
1790 | { | |
1791 | bitmap regs_set = (bitmap) data; | |
1792 | ||
1793 | if (REG_P (x) | |
f773c2bd | 1794 | && HARD_REGISTER_P (x)) |
02b47899 | 1795 | { |
f773c2bd AS |
1796 | unsigned int regno = REGNO (x); |
1797 | bitmap_set_range (regs_set, regno, | |
1798 | hard_regno_nregs[regno][GET_MODE (x)]); | |
02b47899 KZ |
1799 | } |
1800 | } | |
1801 | ||
8dd5516b JJ |
1802 | /* Helper function for replace_read and record_store. |
1803 | Attempt to return a value stored in STORE_INFO, from READ_BEGIN | |
1804 | to one before READ_END bytes read in READ_MODE. Return NULL | |
1805 | if not successful. If REQUIRE_CST is true, return always constant. */ | |
1806 | ||
1807 | static rtx | |
1808 | get_stored_val (store_info_t store_info, enum machine_mode read_mode, | |
1809 | HOST_WIDE_INT read_begin, HOST_WIDE_INT read_end, | |
1810 | basic_block bb, bool require_cst) | |
1811 | { | |
1812 | enum machine_mode store_mode = GET_MODE (store_info->mem); | |
1813 | int shift; | |
1814 | int access_size; /* In bytes. */ | |
1815 | rtx read_reg; | |
1816 | ||
1817 | /* To get here the read is within the boundaries of the write so | |
1818 | shift will never be negative. Start out with the shift being in | |
1819 | bytes. */ | |
1820 | if (store_mode == BLKmode) | |
1821 | shift = 0; | |
1822 | else if (BYTES_BIG_ENDIAN) | |
1823 | shift = store_info->end - read_end; | |
1824 | else | |
1825 | shift = read_begin - store_info->begin; | |
1826 | ||
1827 | access_size = shift + GET_MODE_SIZE (read_mode); | |
1828 | ||
1829 | /* From now on it is bits. */ | |
1830 | shift *= BITS_PER_UNIT; | |
1831 | ||
1832 | if (shift) | |
1833 | read_reg = find_shift_sequence (access_size, store_info, read_mode, shift, | |
1834 | optimize_bb_for_speed_p (bb), | |
1835 | require_cst); | |
1836 | else if (store_mode == BLKmode) | |
1837 | { | |
1838 | /* The store is a memset (addr, const_val, const_size). */ | |
1839 | gcc_assert (CONST_INT_P (store_info->rhs)); | |
1840 | store_mode = int_mode_for_mode (read_mode); | |
1841 | if (store_mode == BLKmode) | |
1842 | read_reg = NULL_RTX; | |
1843 | else if (store_info->rhs == const0_rtx) | |
1844 | read_reg = extract_low_bits (read_mode, store_mode, const0_rtx); | |
1845 | else if (GET_MODE_BITSIZE (store_mode) > HOST_BITS_PER_WIDE_INT | |
1846 | || BITS_PER_UNIT >= HOST_BITS_PER_WIDE_INT) | |
1847 | read_reg = NULL_RTX; | |
1848 | else | |
1849 | { | |
1850 | unsigned HOST_WIDE_INT c | |
1851 | = INTVAL (store_info->rhs) | |
1852 | & (((HOST_WIDE_INT) 1 << BITS_PER_UNIT) - 1); | |
1853 | int shift = BITS_PER_UNIT; | |
1854 | while (shift < HOST_BITS_PER_WIDE_INT) | |
1855 | { | |
1856 | c |= (c << shift); | |
1857 | shift <<= 1; | |
1858 | } | |
1859 | read_reg = GEN_INT (trunc_int_for_mode (c, store_mode)); | |
1860 | read_reg = extract_low_bits (read_mode, store_mode, read_reg); | |
1861 | } | |
1862 | } | |
1863 | else if (store_info->const_rhs | |
1864 | && (require_cst | |
1865 | || GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))) | |
1866 | read_reg = extract_low_bits (read_mode, store_mode, | |
1867 | copy_rtx (store_info->const_rhs)); | |
1868 | else | |
1869 | read_reg = extract_low_bits (read_mode, store_mode, | |
1870 | copy_rtx (store_info->rhs)); | |
1871 | if (require_cst && read_reg && !CONSTANT_P (read_reg)) | |
1872 | read_reg = NULL_RTX; | |
1873 | return read_reg; | |
1874 | } | |
02b47899 | 1875 | |
6fb5fa3c DB |
1876 | /* Take a sequence of: |
1877 | A <- r1 | |
1878 | ... | |
1879 | ... <- A | |
1880 | ||
b8698a0f | 1881 | and change it into |
6fb5fa3c DB |
1882 | r2 <- r1 |
1883 | A <- r1 | |
1884 | ... | |
1885 | ... <- r2 | |
1886 | ||
8660aaae EC |
1887 | or |
1888 | ||
1889 | r3 <- extract (r1) | |
1890 | r3 <- r3 >> shift | |
1891 | r2 <- extract (r3) | |
1892 | ... <- r2 | |
1893 | ||
1894 | or | |
1895 | ||
1896 | r2 <- extract (r1) | |
1897 | ... <- r2 | |
1898 | ||
1899 | Depending on the alignment and the mode of the store and | |
1900 | subsequent load. | |
1901 | ||
1902 | ||
1903 | The STORE_INFO and STORE_INSN are for the store and READ_INFO | |
6fb5fa3c DB |
1904 | and READ_INSN are for the read. Return true if the replacement |
1905 | went ok. */ | |
1906 | ||
1907 | static bool | |
b8698a0f | 1908 | replace_read (store_info_t store_info, insn_info_t store_insn, |
8dd5516b JJ |
1909 | read_info_t read_info, insn_info_t read_insn, rtx *loc, |
1910 | bitmap regs_live) | |
6fb5fa3c | 1911 | { |
8660aaae EC |
1912 | enum machine_mode store_mode = GET_MODE (store_info->mem); |
1913 | enum machine_mode read_mode = GET_MODE (read_info->mem); | |
02b47899 | 1914 | rtx insns, this_insn, read_reg; |
8dd5516b | 1915 | basic_block bb; |
8660aaae | 1916 | |
6fb5fa3c DB |
1917 | if (!dbg_cnt (dse)) |
1918 | return false; | |
1919 | ||
18b526e8 RS |
1920 | /* Create a sequence of instructions to set up the read register. |
1921 | This sequence goes immediately before the store and its result | |
1922 | is read by the load. | |
1923 | ||
1924 | We need to keep this in perspective. We are replacing a read | |
8660aaae EC |
1925 | with a sequence of insns, but the read will almost certainly be |
1926 | in cache, so it is not going to be an expensive one. Thus, we | |
1927 | are not willing to do a multi insn shift or worse a subroutine | |
1928 | call to get rid of the read. */ | |
18b526e8 RS |
1929 | if (dump_file) |
1930 | fprintf (dump_file, "trying to replace %smode load in insn %d" | |
1931 | " from %smode store in insn %d\n", | |
1932 | GET_MODE_NAME (read_mode), INSN_UID (read_insn->insn), | |
1933 | GET_MODE_NAME (store_mode), INSN_UID (store_insn->insn)); | |
1934 | start_sequence (); | |
8dd5516b JJ |
1935 | bb = BLOCK_FOR_INSN (read_insn->insn); |
1936 | read_reg = get_stored_val (store_info, | |
1937 | read_mode, read_info->begin, read_info->end, | |
1938 | bb, false); | |
18b526e8 | 1939 | if (read_reg == NULL_RTX) |
8660aaae | 1940 | { |
18b526e8 RS |
1941 | end_sequence (); |
1942 | if (dump_file) | |
1943 | fprintf (dump_file, " -- could not extract bits of stored value\n"); | |
1944 | return false; | |
8660aaae | 1945 | } |
18b526e8 RS |
1946 | /* Force the value into a new register so that it won't be clobbered |
1947 | between the store and the load. */ | |
1948 | read_reg = copy_to_mode_reg (read_mode, read_reg); | |
1949 | insns = get_insns (); | |
1950 | end_sequence (); | |
8660aaae | 1951 | |
02b47899 KZ |
1952 | if (insns != NULL_RTX) |
1953 | { | |
1954 | /* Now we have to scan the set of new instructions to see if the | |
1955 | sequence contains and sets of hardregs that happened to be | |
1956 | live at this point. For instance, this can happen if one of | |
1957 | the insns sets the CC and the CC happened to be live at that | |
1958 | point. This does occasionally happen, see PR 37922. */ | |
1959 | bitmap regs_set = BITMAP_ALLOC (NULL); | |
1960 | ||
1961 | for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn)) | |
1962 | note_stores (PATTERN (this_insn), look_for_hardregs, regs_set); | |
b8698a0f | 1963 | |
02b47899 KZ |
1964 | bitmap_and_into (regs_set, regs_live); |
1965 | if (!bitmap_empty_p (regs_set)) | |
1966 | { | |
1967 | if (dump_file) | |
1968 | { | |
b8698a0f | 1969 | fprintf (dump_file, |
02b47899 KZ |
1970 | "abandoning replacement because sequence clobbers live hardregs:"); |
1971 | df_print_regset (dump_file, regs_set); | |
1972 | } | |
b8698a0f | 1973 | |
02b47899 KZ |
1974 | BITMAP_FREE (regs_set); |
1975 | return false; | |
1976 | } | |
1977 | BITMAP_FREE (regs_set); | |
1978 | } | |
1979 | ||
8660aaae | 1980 | if (validate_change (read_insn->insn, loc, read_reg, 0)) |
6fb5fa3c | 1981 | { |
f883e0a7 KG |
1982 | deferred_change_t deferred_change = |
1983 | (deferred_change_t) pool_alloc (deferred_change_pool); | |
b8698a0f | 1984 | |
8660aaae EC |
1985 | /* Insert this right before the store insn where it will be safe |
1986 | from later insns that might change it before the read. */ | |
1987 | emit_insn_before (insns, store_insn->insn); | |
b8698a0f | 1988 | |
8660aaae EC |
1989 | /* And now for the kludge part: cselib croaks if you just |
1990 | return at this point. There are two reasons for this: | |
b8698a0f | 1991 | |
8660aaae EC |
1992 | 1) Cselib has an idea of how many pseudos there are and |
1993 | that does not include the new ones we just added. | |
b8698a0f | 1994 | |
8660aaae EC |
1995 | 2) Cselib does not know about the move insn we added |
1996 | above the store_info, and there is no way to tell it | |
1997 | about it, because it has "moved on". | |
b8698a0f | 1998 | |
8660aaae EC |
1999 | Problem (1) is fixable with a certain amount of engineering. |
2000 | Problem (2) is requires starting the bb from scratch. This | |
2001 | could be expensive. | |
b8698a0f | 2002 | |
8660aaae EC |
2003 | So we are just going to have to lie. The move/extraction |
2004 | insns are not really an issue, cselib did not see them. But | |
2005 | the use of the new pseudo read_insn is a real problem because | |
2006 | cselib has not scanned this insn. The way that we solve this | |
2007 | problem is that we are just going to put the mem back for now | |
2008 | and when we are finished with the block, we undo this. We | |
2009 | keep a table of mems to get rid of. At the end of the basic | |
2010 | block we can put them back. */ | |
b8698a0f | 2011 | |
8660aaae EC |
2012 | *loc = read_info->mem; |
2013 | deferred_change->next = deferred_change_list; | |
2014 | deferred_change_list = deferred_change; | |
2015 | deferred_change->loc = loc; | |
2016 | deferred_change->reg = read_reg; | |
b8698a0f | 2017 | |
8660aaae EC |
2018 | /* Get rid of the read_info, from the point of view of the |
2019 | rest of dse, play like this read never happened. */ | |
2020 | read_insn->read_rec = read_info->next; | |
2021 | pool_free (read_info_pool, read_info); | |
18b526e8 RS |
2022 | if (dump_file) |
2023 | { | |
2024 | fprintf (dump_file, " -- replaced the loaded MEM with "); | |
2025 | print_simple_rtl (dump_file, read_reg); | |
2026 | fprintf (dump_file, "\n"); | |
2027 | } | |
8660aaae | 2028 | return true; |
6fb5fa3c | 2029 | } |
b8698a0f | 2030 | else |
6fb5fa3c | 2031 | { |
6fb5fa3c | 2032 | if (dump_file) |
18b526e8 RS |
2033 | { |
2034 | fprintf (dump_file, " -- replacing the loaded MEM with "); | |
2035 | print_simple_rtl (dump_file, read_reg); | |
2036 | fprintf (dump_file, " led to an invalid instruction\n"); | |
2037 | } | |
6fb5fa3c DB |
2038 | return false; |
2039 | } | |
2040 | } | |
2041 | ||
6fb5fa3c DB |
2042 | /* A for_each_rtx callback in which DATA is the bb_info. Check to see |
2043 | if LOC is a mem and if it is look at the address and kill any | |
2044 | appropriate stores that may be active. */ | |
2045 | ||
2046 | static int | |
2047 | check_mem_read_rtx (rtx *loc, void *data) | |
2048 | { | |
6216f94e | 2049 | rtx mem = *loc, mem_addr; |
6fb5fa3c DB |
2050 | bb_info_t bb_info; |
2051 | insn_info_t insn_info; | |
2052 | HOST_WIDE_INT offset = 0; | |
2053 | HOST_WIDE_INT width = 0; | |
4862826d | 2054 | alias_set_type spill_alias_set = 0; |
b8698a0f | 2055 | cselib_val *base = NULL; |
6fb5fa3c DB |
2056 | int group_id; |
2057 | read_info_t read_info; | |
2058 | ||
2059 | if (!mem || !MEM_P (mem)) | |
2060 | return 0; | |
2061 | ||
2062 | bb_info = (bb_info_t) data; | |
2063 | insn_info = bb_info->last_insn; | |
2064 | ||
2065 | if ((MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2066 | || (MEM_VOLATILE_P (mem))) | |
2067 | { | |
2068 | if (dump_file) | |
2069 | fprintf (dump_file, " adding wild read, volatile or barrier.\n"); | |
2070 | add_wild_read (bb_info); | |
2071 | insn_info->cannot_delete = true; | |
2072 | return 0; | |
2073 | } | |
2074 | ||
2075 | /* If it is reading readonly mem, then there can be no conflict with | |
2076 | another write. */ | |
2077 | if (MEM_READONLY_P (mem)) | |
2078 | return 0; | |
2079 | ||
2080 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
2081 | { | |
2082 | if (dump_file) | |
2083 | fprintf (dump_file, " adding wild read, canon_address failure.\n"); | |
2084 | add_wild_read (bb_info); | |
2085 | return 0; | |
2086 | } | |
2087 | ||
2088 | if (GET_MODE (mem) == BLKmode) | |
2089 | width = -1; | |
2090 | else | |
2091 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
2092 | ||
f883e0a7 | 2093 | read_info = (read_info_t) pool_alloc (read_info_pool); |
6fb5fa3c DB |
2094 | read_info->group_id = group_id; |
2095 | read_info->mem = mem; | |
2096 | read_info->alias_set = spill_alias_set; | |
2097 | read_info->begin = offset; | |
2098 | read_info->end = offset + width; | |
2099 | read_info->next = insn_info->read_rec; | |
2100 | insn_info->read_rec = read_info; | |
6216f94e JJ |
2101 | /* For alias_set != 0 canon_true_dependence should be never called. */ |
2102 | if (spill_alias_set) | |
2103 | mem_addr = NULL_RTX; | |
2104 | else | |
2105 | { | |
2106 | if (group_id < 0) | |
2107 | mem_addr = base->val_rtx; | |
2108 | else | |
2109 | { | |
2110 | group_info_t group | |
2111 | = VEC_index (group_info_t, rtx_group_vec, group_id); | |
2112 | mem_addr = group->canon_base_addr; | |
2113 | } | |
2114 | if (offset) | |
2115 | mem_addr = plus_constant (mem_addr, offset); | |
2116 | } | |
6fb5fa3c | 2117 | |
0d52bcc1 | 2118 | /* We ignore the clobbers in store_info. The is mildly aggressive, |
6fb5fa3c DB |
2119 | but there really should not be a clobber followed by a read. */ |
2120 | ||
2121 | if (spill_alias_set) | |
2122 | { | |
2123 | insn_info_t i_ptr = active_local_stores; | |
2124 | insn_info_t last = NULL; | |
2125 | ||
2126 | if (dump_file) | |
2127 | fprintf (dump_file, " processing spill load %d\n", | |
4862826d | 2128 | (int) spill_alias_set); |
6fb5fa3c DB |
2129 | |
2130 | while (i_ptr) | |
2131 | { | |
2132 | store_info_t store_info = i_ptr->store_rec; | |
2133 | ||
2134 | /* Skip the clobbers. */ | |
2135 | while (!store_info->is_set) | |
2136 | store_info = store_info->next; | |
b8698a0f | 2137 | |
6fb5fa3c DB |
2138 | if (store_info->alias_set == spill_alias_set) |
2139 | { | |
2140 | if (dump_file) | |
2141 | dump_insn_info ("removing from active", i_ptr); | |
2142 | ||
dabd47e7 | 2143 | active_local_stores_len--; |
6fb5fa3c DB |
2144 | if (last) |
2145 | last->next_local_store = i_ptr->next_local_store; | |
2146 | else | |
2147 | active_local_stores = i_ptr->next_local_store; | |
2148 | } | |
2149 | else | |
2150 | last = i_ptr; | |
2151 | i_ptr = i_ptr->next_local_store; | |
2152 | } | |
2153 | } | |
2154 | else if (group_id >= 0) | |
2155 | { | |
2156 | /* This is the restricted case where the base is a constant or | |
2157 | the frame pointer and offset is a constant. */ | |
2158 | insn_info_t i_ptr = active_local_stores; | |
2159 | insn_info_t last = NULL; | |
b8698a0f | 2160 | |
6fb5fa3c DB |
2161 | if (dump_file) |
2162 | { | |
2163 | if (width == -1) | |
2164 | fprintf (dump_file, " processing const load gid=%d[BLK]\n", | |
2165 | group_id); | |
2166 | else | |
2167 | fprintf (dump_file, " processing const load gid=%d[%d..%d)\n", | |
2168 | group_id, (int)offset, (int)(offset+width)); | |
2169 | } | |
2170 | ||
2171 | while (i_ptr) | |
2172 | { | |
2173 | bool remove = false; | |
2174 | store_info_t store_info = i_ptr->store_rec; | |
b8698a0f | 2175 | |
6fb5fa3c DB |
2176 | /* Skip the clobbers. */ |
2177 | while (!store_info->is_set) | |
2178 | store_info = store_info->next; | |
b8698a0f | 2179 | |
6fb5fa3c DB |
2180 | /* There are three cases here. */ |
2181 | if (store_info->group_id < 0) | |
2182 | /* We have a cselib store followed by a read from a | |
2183 | const base. */ | |
b8698a0f L |
2184 | remove |
2185 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2186 | GET_MODE (store_info->mem), |
2187 | store_info->mem_addr, | |
6216f94e | 2188 | mem, mem_addr, rtx_varies_p); |
b8698a0f | 2189 | |
6fb5fa3c DB |
2190 | else if (group_id == store_info->group_id) |
2191 | { | |
2192 | /* This is a block mode load. We may get lucky and | |
2193 | canon_true_dependence may save the day. */ | |
2194 | if (width == -1) | |
b8698a0f L |
2195 | remove |
2196 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2197 | GET_MODE (store_info->mem), |
2198 | store_info->mem_addr, | |
6216f94e | 2199 | mem, mem_addr, rtx_varies_p); |
b8698a0f | 2200 | |
6fb5fa3c DB |
2201 | /* If this read is just reading back something that we just |
2202 | stored, rewrite the read. */ | |
b8698a0f | 2203 | else |
6fb5fa3c DB |
2204 | { |
2205 | if (store_info->rhs | |
8dd5516b JJ |
2206 | && offset >= store_info->begin |
2207 | && offset + width <= store_info->end | |
2208 | && all_positions_needed_p (store_info, | |
2209 | offset - store_info->begin, | |
2210 | width) | |
2211 | && replace_read (store_info, i_ptr, read_info, | |
2212 | insn_info, loc, bb_info->regs_live)) | |
2213 | return 0; | |
2214 | ||
6fb5fa3c DB |
2215 | /* The bases are the same, just see if the offsets |
2216 | overlap. */ | |
b8698a0f | 2217 | if ((offset < store_info->end) |
6fb5fa3c DB |
2218 | && (offset + width > store_info->begin)) |
2219 | remove = true; | |
2220 | } | |
2221 | } | |
b8698a0f L |
2222 | |
2223 | /* else | |
6fb5fa3c DB |
2224 | The else case that is missing here is that the |
2225 | bases are constant but different. There is nothing | |
2226 | to do here because there is no overlap. */ | |
b8698a0f | 2227 | |
6fb5fa3c DB |
2228 | if (remove) |
2229 | { | |
2230 | if (dump_file) | |
2231 | dump_insn_info ("removing from active", i_ptr); | |
2232 | ||
dabd47e7 | 2233 | active_local_stores_len--; |
6fb5fa3c DB |
2234 | if (last) |
2235 | last->next_local_store = i_ptr->next_local_store; | |
2236 | else | |
2237 | active_local_stores = i_ptr->next_local_store; | |
2238 | } | |
2239 | else | |
2240 | last = i_ptr; | |
2241 | i_ptr = i_ptr->next_local_store; | |
2242 | } | |
2243 | } | |
b8698a0f | 2244 | else |
6fb5fa3c DB |
2245 | { |
2246 | insn_info_t i_ptr = active_local_stores; | |
2247 | insn_info_t last = NULL; | |
2248 | if (dump_file) | |
2249 | { | |
2250 | fprintf (dump_file, " processing cselib load mem:"); | |
2251 | print_inline_rtx (dump_file, mem, 0); | |
2252 | fprintf (dump_file, "\n"); | |
2253 | } | |
2254 | ||
2255 | while (i_ptr) | |
2256 | { | |
2257 | bool remove = false; | |
2258 | store_info_t store_info = i_ptr->store_rec; | |
b8698a0f | 2259 | |
6fb5fa3c DB |
2260 | if (dump_file) |
2261 | fprintf (dump_file, " processing cselib load against insn %d\n", | |
2262 | INSN_UID (i_ptr->insn)); | |
2263 | ||
2264 | /* Skip the clobbers. */ | |
2265 | while (!store_info->is_set) | |
2266 | store_info = store_info->next; | |
2267 | ||
2268 | /* If this read is just reading back something that we just | |
2269 | stored, rewrite the read. */ | |
2270 | if (store_info->rhs | |
2271 | && store_info->group_id == -1 | |
2272 | && store_info->cse_base == base | |
efc3527a | 2273 | && width != -1 |
8dd5516b JJ |
2274 | && offset >= store_info->begin |
2275 | && offset + width <= store_info->end | |
2276 | && all_positions_needed_p (store_info, | |
2277 | offset - store_info->begin, width) | |
2278 | && replace_read (store_info, i_ptr, read_info, insn_info, loc, | |
2279 | bb_info->regs_live)) | |
2280 | return 0; | |
6fb5fa3c DB |
2281 | |
2282 | if (!store_info->alias_set) | |
b8698a0f | 2283 | remove = canon_true_dependence (store_info->mem, |
6fb5fa3c DB |
2284 | GET_MODE (store_info->mem), |
2285 | store_info->mem_addr, | |
6216f94e | 2286 | mem, mem_addr, rtx_varies_p); |
b8698a0f | 2287 | |
6fb5fa3c DB |
2288 | if (remove) |
2289 | { | |
2290 | if (dump_file) | |
2291 | dump_insn_info ("removing from active", i_ptr); | |
b8698a0f | 2292 | |
dabd47e7 | 2293 | active_local_stores_len--; |
6fb5fa3c DB |
2294 | if (last) |
2295 | last->next_local_store = i_ptr->next_local_store; | |
2296 | else | |
2297 | active_local_stores = i_ptr->next_local_store; | |
2298 | } | |
2299 | else | |
2300 | last = i_ptr; | |
2301 | i_ptr = i_ptr->next_local_store; | |
2302 | } | |
2303 | } | |
2304 | return 0; | |
2305 | } | |
2306 | ||
b8698a0f | 2307 | /* A for_each_rtx callback in which DATA points the INSN_INFO for |
6fb5fa3c DB |
2308 | as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns |
2309 | true for any part of *LOC. */ | |
2310 | ||
2311 | static void | |
2312 | check_mem_read_use (rtx *loc, void *data) | |
2313 | { | |
2314 | for_each_rtx (loc, check_mem_read_rtx, data); | |
2315 | } | |
2316 | ||
8dd5516b JJ |
2317 | |
2318 | /* Get arguments passed to CALL_INSN. Return TRUE if successful. | |
2319 | So far it only handles arguments passed in registers. */ | |
2320 | ||
2321 | static bool | |
2322 | get_call_args (rtx call_insn, tree fn, rtx *args, int nargs) | |
2323 | { | |
d5cc9181 JR |
2324 | CUMULATIVE_ARGS args_so_far_v; |
2325 | cumulative_args_t args_so_far; | |
8dd5516b JJ |
2326 | tree arg; |
2327 | int idx; | |
2328 | ||
d5cc9181 JR |
2329 | INIT_CUMULATIVE_ARGS (args_so_far_v, TREE_TYPE (fn), NULL_RTX, 0, 3); |
2330 | args_so_far = pack_cumulative_args (&args_so_far_v); | |
8dd5516b JJ |
2331 | |
2332 | arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2333 | for (idx = 0; | |
2334 | arg != void_list_node && idx < nargs; | |
2335 | arg = TREE_CHAIN (arg), idx++) | |
2336 | { | |
2337 | enum machine_mode mode = TYPE_MODE (TREE_VALUE (arg)); | |
3c07301f | 2338 | rtx reg, link, tmp; |
d5cc9181 | 2339 | reg = targetm.calls.function_arg (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2340 | if (!reg || !REG_P (reg) || GET_MODE (reg) != mode |
2341 | || GET_MODE_CLASS (mode) != MODE_INT) | |
2342 | return false; | |
2343 | ||
2344 | for (link = CALL_INSN_FUNCTION_USAGE (call_insn); | |
2345 | link; | |
2346 | link = XEXP (link, 1)) | |
2347 | if (GET_CODE (XEXP (link, 0)) == USE) | |
2348 | { | |
2349 | args[idx] = XEXP (XEXP (link, 0), 0); | |
2350 | if (REG_P (args[idx]) | |
2351 | && REGNO (args[idx]) == REGNO (reg) | |
2352 | && (GET_MODE (args[idx]) == mode | |
2353 | || (GET_MODE_CLASS (GET_MODE (args[idx])) == MODE_INT | |
2354 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2355 | <= UNITS_PER_WORD) | |
2356 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2357 | > GET_MODE_SIZE (mode))))) | |
2358 | break; | |
2359 | } | |
2360 | if (!link) | |
2361 | return false; | |
2362 | ||
2363 | tmp = cselib_expand_value_rtx (args[idx], scratch, 5); | |
2364 | if (GET_MODE (args[idx]) != mode) | |
2365 | { | |
2366 | if (!tmp || !CONST_INT_P (tmp)) | |
2367 | return false; | |
2368 | tmp = GEN_INT (trunc_int_for_mode (INTVAL (tmp), mode)); | |
2369 | } | |
2370 | if (tmp) | |
2371 | args[idx] = tmp; | |
2372 | ||
d5cc9181 | 2373 | targetm.calls.function_arg_advance (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2374 | } |
2375 | if (arg != void_list_node || idx != nargs) | |
2376 | return false; | |
2377 | return true; | |
2378 | } | |
2379 | ||
2380 | ||
6fb5fa3c DB |
2381 | /* Apply record_store to all candidate stores in INSN. Mark INSN |
2382 | if some part of it is not a candidate store and assigns to a | |
2383 | non-register target. */ | |
2384 | ||
2385 | static void | |
2386 | scan_insn (bb_info_t bb_info, rtx insn) | |
2387 | { | |
2388 | rtx body; | |
f883e0a7 | 2389 | insn_info_t insn_info = (insn_info_t) pool_alloc (insn_info_pool); |
6fb5fa3c DB |
2390 | int mems_found = 0; |
2391 | memset (insn_info, 0, sizeof (struct insn_info)); | |
2392 | ||
2393 | if (dump_file) | |
2394 | fprintf (dump_file, "\n**scanning insn=%d\n", | |
2395 | INSN_UID (insn)); | |
2396 | ||
2397 | insn_info->prev_insn = bb_info->last_insn; | |
2398 | insn_info->insn = insn; | |
2399 | bb_info->last_insn = insn_info; | |
b8698a0f | 2400 | |
b5b8b0ac AO |
2401 | if (DEBUG_INSN_P (insn)) |
2402 | { | |
2403 | insn_info->cannot_delete = true; | |
2404 | return; | |
2405 | } | |
6fb5fa3c | 2406 | |
0d52bcc1 | 2407 | /* Cselib clears the table for this case, so we have to essentially |
6fb5fa3c DB |
2408 | do the same. */ |
2409 | if (NONJUMP_INSN_P (insn) | |
2410 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2411 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2412 | { | |
2413 | add_wild_read (bb_info); | |
2414 | insn_info->cannot_delete = true; | |
2415 | return; | |
2416 | } | |
2417 | ||
2418 | /* Look at all of the uses in the insn. */ | |
2419 | note_uses (&PATTERN (insn), check_mem_read_use, bb_info); | |
2420 | ||
2421 | if (CALL_P (insn)) | |
2422 | { | |
8dd5516b JJ |
2423 | bool const_call; |
2424 | tree memset_call = NULL_TREE; | |
2425 | ||
6fb5fa3c | 2426 | insn_info->cannot_delete = true; |
50f0f366 | 2427 | |
6fb5fa3c | 2428 | /* Const functions cannot do anything bad i.e. read memory, |
50f0f366 | 2429 | however, they can read their parameters which may have |
8dd5516b JJ |
2430 | been pushed onto the stack. |
2431 | memset and bzero don't read memory either. */ | |
2432 | const_call = RTL_CONST_CALL_P (insn); | |
2433 | if (!const_call) | |
2434 | { | |
2435 | rtx call = PATTERN (insn); | |
2436 | if (GET_CODE (call) == PARALLEL) | |
2437 | call = XVECEXP (call, 0, 0); | |
2438 | if (GET_CODE (call) == SET) | |
2439 | call = SET_SRC (call); | |
2440 | if (GET_CODE (call) == CALL | |
2441 | && MEM_P (XEXP (call, 0)) | |
2442 | && GET_CODE (XEXP (XEXP (call, 0), 0)) == SYMBOL_REF) | |
2443 | { | |
2444 | rtx symbol = XEXP (XEXP (call, 0), 0); | |
2445 | if (SYMBOL_REF_DECL (symbol) | |
2446 | && TREE_CODE (SYMBOL_REF_DECL (symbol)) == FUNCTION_DECL) | |
2447 | { | |
2448 | if ((DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (symbol)) | |
2449 | == BUILT_IN_NORMAL | |
2450 | && (DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol)) | |
2451 | == BUILT_IN_MEMSET)) | |
2452 | || SYMBOL_REF_DECL (symbol) == block_clear_fn) | |
2453 | memset_call = SYMBOL_REF_DECL (symbol); | |
2454 | } | |
2455 | } | |
2456 | } | |
2457 | if (const_call || memset_call) | |
6fb5fa3c DB |
2458 | { |
2459 | insn_info_t i_ptr = active_local_stores; | |
2460 | insn_info_t last = NULL; | |
2461 | ||
2462 | if (dump_file) | |
8dd5516b JJ |
2463 | fprintf (dump_file, "%s call %d\n", |
2464 | const_call ? "const" : "memset", INSN_UID (insn)); | |
6fb5fa3c | 2465 | |
64520bdc EB |
2466 | /* See the head comment of the frame_read field. */ |
2467 | if (reload_completed) | |
2468 | insn_info->frame_read = true; | |
2469 | ||
2470 | /* Loop over the active stores and remove those which are | |
2471 | killed by the const function call. */ | |
6fb5fa3c DB |
2472 | while (i_ptr) |
2473 | { | |
64520bdc EB |
2474 | bool remove_store = false; |
2475 | ||
2476 | /* The stack pointer based stores are always killed. */ | |
50f0f366 | 2477 | if (i_ptr->stack_pointer_based) |
64520bdc EB |
2478 | remove_store = true; |
2479 | ||
2480 | /* If the frame is read, the frame related stores are killed. */ | |
2481 | else if (insn_info->frame_read) | |
2482 | { | |
2483 | store_info_t store_info = i_ptr->store_rec; | |
2484 | ||
2485 | /* Skip the clobbers. */ | |
2486 | while (!store_info->is_set) | |
2487 | store_info = store_info->next; | |
2488 | ||
2489 | if (store_info->group_id >= 0 | |
2490 | && VEC_index (group_info_t, rtx_group_vec, | |
2491 | store_info->group_id)->frame_related) | |
2492 | remove_store = true; | |
2493 | } | |
2494 | ||
2495 | if (remove_store) | |
6fb5fa3c DB |
2496 | { |
2497 | if (dump_file) | |
2498 | dump_insn_info ("removing from active", i_ptr); | |
b8698a0f | 2499 | |
dabd47e7 | 2500 | active_local_stores_len--; |
6fb5fa3c DB |
2501 | if (last) |
2502 | last->next_local_store = i_ptr->next_local_store; | |
2503 | else | |
2504 | active_local_stores = i_ptr->next_local_store; | |
2505 | } | |
2506 | else | |
2507 | last = i_ptr; | |
64520bdc | 2508 | |
6fb5fa3c DB |
2509 | i_ptr = i_ptr->next_local_store; |
2510 | } | |
8dd5516b JJ |
2511 | |
2512 | if (memset_call) | |
2513 | { | |
2514 | rtx args[3]; | |
2515 | if (get_call_args (insn, memset_call, args, 3) | |
2516 | && CONST_INT_P (args[1]) | |
2517 | && CONST_INT_P (args[2]) | |
2518 | && INTVAL (args[2]) > 0) | |
2519 | { | |
2520 | rtx mem = gen_rtx_MEM (BLKmode, args[0]); | |
2521 | set_mem_size (mem, args[2]); | |
2522 | body = gen_rtx_SET (VOIDmode, mem, args[1]); | |
2523 | mems_found += record_store (body, bb_info); | |
2524 | if (dump_file) | |
2525 | fprintf (dump_file, "handling memset as BLKmode store\n"); | |
2526 | if (mems_found == 1) | |
2527 | { | |
dabd47e7 JJ |
2528 | if (active_local_stores_len++ |
2529 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2530 | { | |
2531 | active_local_stores_len = 1; | |
2532 | active_local_stores = NULL; | |
2533 | } | |
8dd5516b JJ |
2534 | insn_info->next_local_store = active_local_stores; |
2535 | active_local_stores = insn_info; | |
2536 | } | |
2537 | } | |
2538 | } | |
6fb5fa3c DB |
2539 | } |
2540 | ||
50f0f366 | 2541 | else |
d26c7090 ER |
2542 | /* Every other call, including pure functions, may read any memory |
2543 | that is not relative to the frame. */ | |
2544 | add_non_frame_wild_read (bb_info); | |
50f0f366 | 2545 | |
6fb5fa3c DB |
2546 | return; |
2547 | } | |
2548 | ||
2549 | /* Assuming that there are sets in these insns, we cannot delete | |
2550 | them. */ | |
2551 | if ((GET_CODE (PATTERN (insn)) == CLOBBER) | |
0a64eeca | 2552 | || volatile_refs_p (PATTERN (insn)) |
1d65f45c | 2553 | || insn_could_throw_p (insn) |
6fb5fa3c DB |
2554 | || (RTX_FRAME_RELATED_P (insn)) |
2555 | || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX)) | |
2556 | insn_info->cannot_delete = true; | |
b8698a0f | 2557 | |
6fb5fa3c DB |
2558 | body = PATTERN (insn); |
2559 | if (GET_CODE (body) == PARALLEL) | |
2560 | { | |
2561 | int i; | |
2562 | for (i = 0; i < XVECLEN (body, 0); i++) | |
2563 | mems_found += record_store (XVECEXP (body, 0, i), bb_info); | |
2564 | } | |
2565 | else | |
2566 | mems_found += record_store (body, bb_info); | |
2567 | ||
2568 | if (dump_file) | |
b8698a0f | 2569 | fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n", |
6fb5fa3c DB |
2570 | mems_found, insn_info->cannot_delete ? "true" : "false"); |
2571 | ||
8dd5516b JJ |
2572 | /* If we found some sets of mems, add it into the active_local_stores so |
2573 | that it can be locally deleted if found dead or used for | |
2574 | replace_read and redundant constant store elimination. Otherwise mark | |
2575 | it as cannot delete. This simplifies the processing later. */ | |
2576 | if (mems_found == 1) | |
6fb5fa3c | 2577 | { |
dabd47e7 JJ |
2578 | if (active_local_stores_len++ |
2579 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2580 | { | |
2581 | active_local_stores_len = 1; | |
2582 | active_local_stores = NULL; | |
2583 | } | |
6fb5fa3c DB |
2584 | insn_info->next_local_store = active_local_stores; |
2585 | active_local_stores = insn_info; | |
2586 | } | |
2587 | else | |
2588 | insn_info->cannot_delete = true; | |
2589 | } | |
2590 | ||
2591 | ||
2592 | /* Remove BASE from the set of active_local_stores. This is a | |
2593 | callback from cselib that is used to get rid of the stores in | |
2594 | active_local_stores. */ | |
2595 | ||
2596 | static void | |
2597 | remove_useless_values (cselib_val *base) | |
2598 | { | |
2599 | insn_info_t insn_info = active_local_stores; | |
2600 | insn_info_t last = NULL; | |
2601 | ||
2602 | while (insn_info) | |
2603 | { | |
2604 | store_info_t store_info = insn_info->store_rec; | |
60564289 | 2605 | bool del = false; |
6fb5fa3c DB |
2606 | |
2607 | /* If ANY of the store_infos match the cselib group that is | |
2608 | being deleted, then the insn can not be deleted. */ | |
2609 | while (store_info) | |
2610 | { | |
b8698a0f | 2611 | if ((store_info->group_id == -1) |
6fb5fa3c DB |
2612 | && (store_info->cse_base == base)) |
2613 | { | |
60564289 | 2614 | del = true; |
6fb5fa3c DB |
2615 | break; |
2616 | } | |
2617 | store_info = store_info->next; | |
2618 | } | |
2619 | ||
60564289 | 2620 | if (del) |
6fb5fa3c | 2621 | { |
dabd47e7 | 2622 | active_local_stores_len--; |
6fb5fa3c DB |
2623 | if (last) |
2624 | last->next_local_store = insn_info->next_local_store; | |
2625 | else | |
2626 | active_local_stores = insn_info->next_local_store; | |
2627 | free_store_info (insn_info); | |
2628 | } | |
2629 | else | |
2630 | last = insn_info; | |
b8698a0f | 2631 | |
6fb5fa3c DB |
2632 | insn_info = insn_info->next_local_store; |
2633 | } | |
2634 | } | |
2635 | ||
2636 | ||
2637 | /* Do all of step 1. */ | |
2638 | ||
2639 | static void | |
2640 | dse_step1 (void) | |
2641 | { | |
2642 | basic_block bb; | |
02b47899 | 2643 | bitmap regs_live = BITMAP_ALLOC (NULL); |
b8698a0f | 2644 | |
457eeaae | 2645 | cselib_init (0); |
6fb5fa3c DB |
2646 | all_blocks = BITMAP_ALLOC (NULL); |
2647 | bitmap_set_bit (all_blocks, ENTRY_BLOCK); | |
2648 | bitmap_set_bit (all_blocks, EXIT_BLOCK); | |
2649 | ||
2650 | FOR_ALL_BB (bb) | |
2651 | { | |
2652 | insn_info_t ptr; | |
f883e0a7 | 2653 | bb_info_t bb_info = (bb_info_t) pool_alloc (bb_info_pool); |
6fb5fa3c DB |
2654 | |
2655 | memset (bb_info, 0, sizeof (struct bb_info)); | |
2656 | bitmap_set_bit (all_blocks, bb->index); | |
02b47899 KZ |
2657 | bb_info->regs_live = regs_live; |
2658 | ||
2659 | bitmap_copy (regs_live, DF_LR_IN (bb)); | |
2660 | df_simulate_initialize_forwards (bb, regs_live); | |
6fb5fa3c DB |
2661 | |
2662 | bb_table[bb->index] = bb_info; | |
2663 | cselib_discard_hook = remove_useless_values; | |
2664 | ||
2665 | if (bb->index >= NUM_FIXED_BLOCKS) | |
2666 | { | |
2667 | rtx insn; | |
2668 | ||
2669 | cse_store_info_pool | |
b8698a0f | 2670 | = create_alloc_pool ("cse_store_info_pool", |
6fb5fa3c DB |
2671 | sizeof (struct store_info), 100); |
2672 | active_local_stores = NULL; | |
dabd47e7 | 2673 | active_local_stores_len = 0; |
6fb5fa3c | 2674 | cselib_clear_table (); |
b8698a0f | 2675 | |
6fb5fa3c DB |
2676 | /* Scan the insns. */ |
2677 | FOR_BB_INSNS (bb, insn) | |
2678 | { | |
2679 | if (INSN_P (insn)) | |
2680 | scan_insn (bb_info, insn); | |
2681 | cselib_process_insn (insn); | |
02b47899 KZ |
2682 | if (INSN_P (insn)) |
2683 | df_simulate_one_insn_forwards (bb, insn, regs_live); | |
6fb5fa3c | 2684 | } |
b8698a0f | 2685 | |
6fb5fa3c DB |
2686 | /* This is something of a hack, because the global algorithm |
2687 | is supposed to take care of the case where stores go dead | |
2688 | at the end of the function. However, the global | |
2689 | algorithm must take a more conservative view of block | |
2690 | mode reads than the local alg does. So to get the case | |
2691 | where you have a store to the frame followed by a non | |
0d52bcc1 | 2692 | overlapping block more read, we look at the active local |
6fb5fa3c DB |
2693 | stores at the end of the function and delete all of the |
2694 | frame and spill based ones. */ | |
2695 | if (stores_off_frame_dead_at_return | |
2696 | && (EDGE_COUNT (bb->succs) == 0 | |
2697 | || (single_succ_p (bb) | |
2698 | && single_succ (bb) == EXIT_BLOCK_PTR | |
e3b5732b | 2699 | && ! crtl->calls_eh_return))) |
6fb5fa3c DB |
2700 | { |
2701 | insn_info_t i_ptr = active_local_stores; | |
2702 | while (i_ptr) | |
2703 | { | |
2704 | store_info_t store_info = i_ptr->store_rec; | |
2705 | ||
2706 | /* Skip the clobbers. */ | |
2707 | while (!store_info->is_set) | |
2708 | store_info = store_info->next; | |
8dd5516b | 2709 | if (store_info->alias_set && !i_ptr->cannot_delete) |
6fb5fa3c | 2710 | delete_dead_store_insn (i_ptr); |
b8698a0f | 2711 | else |
6fb5fa3c DB |
2712 | if (store_info->group_id >= 0) |
2713 | { | |
b8698a0f | 2714 | group_info_t group |
6fb5fa3c | 2715 | = VEC_index (group_info_t, rtx_group_vec, store_info->group_id); |
8dd5516b | 2716 | if (group->frame_related && !i_ptr->cannot_delete) |
6fb5fa3c DB |
2717 | delete_dead_store_insn (i_ptr); |
2718 | } | |
2719 | ||
2720 | i_ptr = i_ptr->next_local_store; | |
2721 | } | |
2722 | } | |
2723 | ||
2724 | /* Get rid of the loads that were discovered in | |
2725 | replace_read. Cselib is finished with this block. */ | |
2726 | while (deferred_change_list) | |
2727 | { | |
2728 | deferred_change_t next = deferred_change_list->next; | |
2729 | ||
2730 | /* There is no reason to validate this change. That was | |
2731 | done earlier. */ | |
2732 | *deferred_change_list->loc = deferred_change_list->reg; | |
2733 | pool_free (deferred_change_pool, deferred_change_list); | |
2734 | deferred_change_list = next; | |
2735 | } | |
2736 | ||
2737 | /* Get rid of all of the cselib based store_infos in this | |
2738 | block and mark the containing insns as not being | |
2739 | deletable. */ | |
2740 | ptr = bb_info->last_insn; | |
2741 | while (ptr) | |
2742 | { | |
2743 | if (ptr->contains_cselib_groups) | |
8dd5516b JJ |
2744 | { |
2745 | store_info_t s_info = ptr->store_rec; | |
2746 | while (s_info && !s_info->is_set) | |
2747 | s_info = s_info->next; | |
2748 | if (s_info | |
2749 | && s_info->redundant_reason | |
2750 | && s_info->redundant_reason->insn | |
2751 | && !ptr->cannot_delete) | |
2752 | { | |
2753 | if (dump_file) | |
2754 | fprintf (dump_file, "Locally deleting insn %d " | |
2755 | "because insn %d stores the " | |
2756 | "same value and couldn't be " | |
2757 | "eliminated\n", | |
2758 | INSN_UID (ptr->insn), | |
2759 | INSN_UID (s_info->redundant_reason->insn)); | |
2760 | delete_dead_store_insn (ptr); | |
2761 | } | |
2762 | if (s_info) | |
2763 | s_info->redundant_reason = NULL; | |
2764 | free_store_info (ptr); | |
2765 | } | |
2766 | else | |
2767 | { | |
2768 | store_info_t s_info; | |
2769 | ||
2770 | /* Free at least positions_needed bitmaps. */ | |
2771 | for (s_info = ptr->store_rec; s_info; s_info = s_info->next) | |
2772 | if (s_info->is_large) | |
2773 | { | |
dc491a25 | 2774 | BITMAP_FREE (s_info->positions_needed.large.bmap); |
8dd5516b JJ |
2775 | s_info->is_large = false; |
2776 | } | |
2777 | } | |
6fb5fa3c DB |
2778 | ptr = ptr->prev_insn; |
2779 | } | |
2780 | ||
2781 | free_alloc_pool (cse_store_info_pool); | |
2782 | } | |
02b47899 | 2783 | bb_info->regs_live = NULL; |
6fb5fa3c DB |
2784 | } |
2785 | ||
02b47899 | 2786 | BITMAP_FREE (regs_live); |
6fb5fa3c DB |
2787 | cselib_finish (); |
2788 | htab_empty (rtx_group_table); | |
2789 | } | |
2790 | ||
2791 | \f | |
2792 | /*---------------------------------------------------------------------------- | |
2793 | Second step. | |
2794 | ||
2795 | Assign each byte position in the stores that we are going to | |
2796 | analyze globally to a position in the bitmaps. Returns true if | |
6ed3da00 | 2797 | there are any bit positions assigned. |
6fb5fa3c DB |
2798 | ----------------------------------------------------------------------------*/ |
2799 | ||
2800 | static void | |
2801 | dse_step2_init (void) | |
2802 | { | |
2803 | unsigned int i; | |
2804 | group_info_t group; | |
2805 | ||
ac47786e | 2806 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c DB |
2807 | { |
2808 | /* For all non stack related bases, we only consider a store to | |
2809 | be deletable if there are two or more stores for that | |
2810 | position. This is because it takes one store to make the | |
2811 | other store redundant. However, for the stores that are | |
2812 | stack related, we consider them if there is only one store | |
2813 | for the position. We do this because the stack related | |
2814 | stores can be deleted if their is no read between them and | |
2815 | the end of the function. | |
b8698a0f | 2816 | |
6fb5fa3c DB |
2817 | To make this work in the current framework, we take the stack |
2818 | related bases add all of the bits from store1 into store2. | |
2819 | This has the effect of making the eligible even if there is | |
2820 | only one store. */ | |
2821 | ||
2822 | if (stores_off_frame_dead_at_return && group->frame_related) | |
2823 | { | |
2824 | bitmap_ior_into (group->store2_n, group->store1_n); | |
2825 | bitmap_ior_into (group->store2_p, group->store1_p); | |
2826 | if (dump_file) | |
b8698a0f | 2827 | fprintf (dump_file, "group %d is frame related ", i); |
6fb5fa3c DB |
2828 | } |
2829 | ||
2830 | group->offset_map_size_n++; | |
2831 | group->offset_map_n = XNEWVEC (int, group->offset_map_size_n); | |
2832 | group->offset_map_size_p++; | |
2833 | group->offset_map_p = XNEWVEC (int, group->offset_map_size_p); | |
2834 | group->process_globally = false; | |
2835 | if (dump_file) | |
2836 | { | |
b8698a0f | 2837 | fprintf (dump_file, "group %d(%d+%d): ", i, |
6fb5fa3c DB |
2838 | (int)bitmap_count_bits (group->store2_n), |
2839 | (int)bitmap_count_bits (group->store2_p)); | |
2840 | bitmap_print (dump_file, group->store2_n, "n ", " "); | |
2841 | bitmap_print (dump_file, group->store2_p, "p ", "\n"); | |
2842 | } | |
2843 | } | |
2844 | } | |
2845 | ||
2846 | ||
2847 | /* Init the offset tables for the normal case. */ | |
2848 | ||
2849 | static bool | |
2850 | dse_step2_nospill (void) | |
2851 | { | |
2852 | unsigned int i; | |
2853 | group_info_t group; | |
2854 | /* Position 0 is unused because 0 is used in the maps to mean | |
2855 | unused. */ | |
2856 | current_position = 1; | |
ac47786e | 2857 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c DB |
2858 | { |
2859 | bitmap_iterator bi; | |
2860 | unsigned int j; | |
2861 | ||
2862 | if (group == clear_alias_group) | |
2863 | continue; | |
2864 | ||
2865 | memset (group->offset_map_n, 0, sizeof(int) * group->offset_map_size_n); | |
2866 | memset (group->offset_map_p, 0, sizeof(int) * group->offset_map_size_p); | |
2867 | bitmap_clear (group->group_kill); | |
2868 | ||
2869 | EXECUTE_IF_SET_IN_BITMAP (group->store2_n, 0, j, bi) | |
2870 | { | |
2871 | bitmap_set_bit (group->group_kill, current_position); | |
d26c7090 ER |
2872 | if (bitmap_bit_p (group->escaped_n, j)) |
2873 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2874 | group->offset_map_n[j] = current_position++; |
2875 | group->process_globally = true; | |
2876 | } | |
2877 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2878 | { | |
b8698a0f | 2879 | bitmap_set_bit (group->group_kill, current_position); |
d26c7090 ER |
2880 | if (bitmap_bit_p (group->escaped_p, j)) |
2881 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2882 | group->offset_map_p[j] = current_position++; |
2883 | group->process_globally = true; | |
2884 | } | |
2885 | } | |
2886 | return current_position != 1; | |
2887 | } | |
2888 | ||
2889 | ||
2890 | /* Init the offset tables for the spill case. */ | |
2891 | ||
2892 | static bool | |
2893 | dse_step2_spill (void) | |
2894 | { | |
2895 | unsigned int j; | |
2896 | group_info_t group = clear_alias_group; | |
2897 | bitmap_iterator bi; | |
2898 | ||
2899 | /* Position 0 is unused because 0 is used in the maps to mean | |
2900 | unused. */ | |
2901 | current_position = 1; | |
2902 | ||
2903 | if (dump_file) | |
2904 | { | |
b8698a0f | 2905 | bitmap_print (dump_file, clear_alias_sets, |
6fb5fa3c | 2906 | "clear alias sets ", "\n"); |
b8698a0f | 2907 | bitmap_print (dump_file, disqualified_clear_alias_sets, |
6fb5fa3c DB |
2908 | "disqualified clear alias sets ", "\n"); |
2909 | } | |
2910 | ||
2911 | memset (group->offset_map_n, 0, sizeof(int) * group->offset_map_size_n); | |
2912 | memset (group->offset_map_p, 0, sizeof(int) * group->offset_map_size_p); | |
2913 | bitmap_clear (group->group_kill); | |
b8698a0f | 2914 | |
6fb5fa3c DB |
2915 | /* Remove the disqualified positions from the store2_p set. */ |
2916 | bitmap_and_compl_into (group->store2_p, disqualified_clear_alias_sets); | |
b8698a0f | 2917 | |
6fb5fa3c DB |
2918 | /* We do not need to process the store2_n set because |
2919 | alias_sets are always positive. */ | |
2920 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2921 | { | |
b8698a0f | 2922 | bitmap_set_bit (group->group_kill, current_position); |
6fb5fa3c DB |
2923 | group->offset_map_p[j] = current_position++; |
2924 | group->process_globally = true; | |
2925 | } | |
2926 | ||
2927 | return current_position != 1; | |
2928 | } | |
2929 | ||
2930 | ||
2931 | \f | |
2932 | /*---------------------------------------------------------------------------- | |
2933 | Third step. | |
b8698a0f | 2934 | |
6fb5fa3c DB |
2935 | Build the bit vectors for the transfer functions. |
2936 | ----------------------------------------------------------------------------*/ | |
2937 | ||
2938 | ||
2939 | /* Note that this is NOT a general purpose function. Any mem that has | |
2940 | an alias set registered here expected to be COMPLETELY unaliased: | |
b8698a0f | 2941 | i.e it's addresses are not and need not be examined. |
6fb5fa3c DB |
2942 | |
2943 | It is known that all references to this address will have this | |
2944 | alias set and there are NO other references to this address in the | |
b8698a0f | 2945 | function. |
6fb5fa3c DB |
2946 | |
2947 | Currently the only place that is known to be clean enough to use | |
b8698a0f | 2948 | this interface is the code that assigns the spill locations. |
6fb5fa3c DB |
2949 | |
2950 | All of the mems that have alias_sets registered are subjected to a | |
2951 | very powerful form of dse where function calls, volatile reads and | |
b8698a0f | 2952 | writes, and reads from random location are not taken into account. |
6fb5fa3c DB |
2953 | |
2954 | It is also assumed that these locations go dead when the function | |
2955 | returns. This assumption could be relaxed if there were found to | |
2956 | be places that this assumption was not correct. | |
2957 | ||
2958 | The MODE is passed in and saved. The mode of each load or store to | |
2959 | a mem with ALIAS_SET is checked against MEM. If the size of that | |
2960 | load or store is different from MODE, processing is halted on this | |
2961 | alias set. For the vast majority of aliases sets, all of the loads | |
2962 | and stores will use the same mode. But vectors are treated | |
2963 | differently: the alias set is established for the entire vector, | |
2964 | but reload will insert loads and stores for individual elements and | |
2965 | we do not necessarily have the information to track those separate | |
2966 | elements. So when we see a mode mismatch, we just bail. */ | |
2967 | ||
2968 | ||
b8698a0f L |
2969 | void |
2970 | dse_record_singleton_alias_set (alias_set_type alias_set, | |
6fb5fa3c DB |
2971 | enum machine_mode mode) |
2972 | { | |
2973 | struct clear_alias_mode_holder tmp_holder; | |
2974 | struct clear_alias_mode_holder *entry; | |
2975 | void **slot; | |
2976 | ||
2977 | /* If we are not going to run dse, we need to return now or there | |
2978 | will be problems with allocating the bitmaps. */ | |
2979 | if ((!gate_dse()) || !alias_set) | |
2980 | return; | |
2981 | ||
2982 | if (!clear_alias_sets) | |
2983 | { | |
2984 | clear_alias_sets = BITMAP_ALLOC (NULL); | |
2985 | disqualified_clear_alias_sets = BITMAP_ALLOC (NULL); | |
2986 | clear_alias_mode_table = htab_create (11, clear_alias_mode_hash, | |
2987 | clear_alias_mode_eq, NULL); | |
b8698a0f | 2988 | clear_alias_mode_pool = create_alloc_pool ("clear_alias_mode_pool", |
6fb5fa3c DB |
2989 | sizeof (struct clear_alias_mode_holder), 100); |
2990 | } | |
2991 | ||
2992 | bitmap_set_bit (clear_alias_sets, alias_set); | |
2993 | ||
2994 | tmp_holder.alias_set = alias_set; | |
2995 | ||
2996 | slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, INSERT); | |
2997 | gcc_assert (*slot == NULL); | |
2998 | ||
f883e0a7 KG |
2999 | *slot = entry = |
3000 | (struct clear_alias_mode_holder *) pool_alloc (clear_alias_mode_pool); | |
6fb5fa3c DB |
3001 | entry->alias_set = alias_set; |
3002 | entry->mode = mode; | |
3003 | } | |
3004 | ||
3005 | ||
3006 | /* Remove ALIAS_SET from the sets of stack slots being considered. */ | |
3007 | ||
b8698a0f | 3008 | void |
4862826d | 3009 | dse_invalidate_singleton_alias_set (alias_set_type alias_set) |
6fb5fa3c DB |
3010 | { |
3011 | if ((!gate_dse()) || !alias_set) | |
3012 | return; | |
3013 | ||
3014 | bitmap_clear_bit (clear_alias_sets, alias_set); | |
3015 | } | |
3016 | ||
3017 | ||
3018 | /* Look up the bitmap index for OFFSET in GROUP_INFO. If it is not | |
3019 | there, return 0. */ | |
3020 | ||
3021 | static int | |
3022 | get_bitmap_index (group_info_t group_info, HOST_WIDE_INT offset) | |
3023 | { | |
3024 | if (offset < 0) | |
3025 | { | |
3026 | HOST_WIDE_INT offset_p = -offset; | |
3027 | if (offset_p >= group_info->offset_map_size_n) | |
3028 | return 0; | |
3029 | return group_info->offset_map_n[offset_p]; | |
3030 | } | |
3031 | else | |
3032 | { | |
3033 | if (offset >= group_info->offset_map_size_p) | |
3034 | return 0; | |
3035 | return group_info->offset_map_p[offset]; | |
3036 | } | |
3037 | } | |
3038 | ||
3039 | ||
3040 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
3041 | may be NULL. */ | |
3042 | ||
b8698a0f | 3043 | static void |
6fb5fa3c DB |
3044 | scan_stores_nospill (store_info_t store_info, bitmap gen, bitmap kill) |
3045 | { | |
3046 | while (store_info) | |
3047 | { | |
3048 | HOST_WIDE_INT i; | |
b8698a0f | 3049 | group_info_t group_info |
6fb5fa3c DB |
3050 | = VEC_index (group_info_t, rtx_group_vec, store_info->group_id); |
3051 | if (group_info->process_globally) | |
3052 | for (i = store_info->begin; i < store_info->end; i++) | |
3053 | { | |
3054 | int index = get_bitmap_index (group_info, i); | |
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 STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
3068 | may be NULL. */ | |
3069 | ||
b8698a0f | 3070 | static void |
6fb5fa3c DB |
3071 | scan_stores_spill (store_info_t store_info, bitmap gen, bitmap kill) |
3072 | { | |
3073 | while (store_info) | |
3074 | { | |
3075 | if (store_info->alias_set) | |
3076 | { | |
b8698a0f | 3077 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3078 | store_info->alias_set); |
3079 | if (index != 0) | |
3080 | { | |
3081 | bitmap_set_bit (gen, index); | |
3082 | if (kill) | |
3083 | bitmap_clear_bit (kill, index); | |
3084 | } | |
3085 | } | |
3086 | store_info = store_info->next; | |
3087 | } | |
3088 | } | |
3089 | ||
3090 | ||
3091 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3092 | may be NULL. */ | |
3093 | ||
3094 | static void | |
3095 | scan_reads_nospill (insn_info_t insn_info, bitmap gen, bitmap kill) | |
3096 | { | |
3097 | read_info_t read_info = insn_info->read_rec; | |
3098 | int i; | |
3099 | group_info_t group; | |
3100 | ||
64520bdc EB |
3101 | /* If this insn reads the frame, kill all the frame related stores. */ |
3102 | if (insn_info->frame_read) | |
3103 | { | |
ac47786e | 3104 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
64520bdc EB |
3105 | if (group->process_globally && group->frame_related) |
3106 | { | |
3107 | if (kill) | |
3108 | bitmap_ior_into (kill, group->group_kill); | |
b8698a0f | 3109 | bitmap_and_compl_into (gen, group->group_kill); |
64520bdc EB |
3110 | } |
3111 | } | |
d26c7090 ER |
3112 | if (insn_info->non_frame_wild_read) |
3113 | { | |
3114 | /* Kill all non-frame related stores. Kill all stores of variables that | |
3115 | escape. */ | |
3116 | if (kill) | |
3117 | bitmap_ior_into (kill, kill_on_calls); | |
3118 | bitmap_and_compl_into (gen, kill_on_calls); | |
3119 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) | |
3120 | if (group->process_globally && !group->frame_related) | |
3121 | { | |
3122 | if (kill) | |
3123 | bitmap_ior_into (kill, group->group_kill); | |
3124 | bitmap_and_compl_into (gen, group->group_kill); | |
3125 | } | |
3126 | } | |
6fb5fa3c DB |
3127 | while (read_info) |
3128 | { | |
ac47786e | 3129 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c DB |
3130 | { |
3131 | if (group->process_globally) | |
3132 | { | |
3133 | if (i == read_info->group_id) | |
3134 | { | |
3135 | if (read_info->begin > read_info->end) | |
3136 | { | |
3137 | /* Begin > end for block mode reads. */ | |
3138 | if (kill) | |
3139 | bitmap_ior_into (kill, group->group_kill); | |
3140 | bitmap_and_compl_into (gen, group->group_kill); | |
3141 | } | |
3142 | else | |
3143 | { | |
3144 | /* The groups are the same, just process the | |
3145 | offsets. */ | |
3146 | HOST_WIDE_INT j; | |
3147 | for (j = read_info->begin; j < read_info->end; j++) | |
3148 | { | |
3149 | int index = get_bitmap_index (group, j); | |
3150 | if (index != 0) | |
3151 | { | |
3152 | if (kill) | |
3153 | bitmap_set_bit (kill, index); | |
3154 | bitmap_clear_bit (gen, index); | |
3155 | } | |
3156 | } | |
3157 | } | |
3158 | } | |
3159 | else | |
3160 | { | |
3161 | /* The groups are different, if the alias sets | |
3162 | conflict, clear the entire group. We only need | |
3163 | to apply this test if the read_info is a cselib | |
3164 | read. Anything with a constant base cannot alias | |
3165 | something else with a different constant | |
3166 | base. */ | |
3167 | if ((read_info->group_id < 0) | |
b8698a0f | 3168 | && canon_true_dependence (group->base_mem, |
d32f725a | 3169 | GET_MODE (group->base_mem), |
6216f94e JJ |
3170 | group->canon_base_addr, |
3171 | read_info->mem, NULL_RTX, | |
3172 | rtx_varies_p)) | |
6fb5fa3c DB |
3173 | { |
3174 | if (kill) | |
3175 | bitmap_ior_into (kill, group->group_kill); | |
3176 | bitmap_and_compl_into (gen, group->group_kill); | |
3177 | } | |
3178 | } | |
3179 | } | |
3180 | } | |
b8698a0f | 3181 | |
6fb5fa3c DB |
3182 | read_info = read_info->next; |
3183 | } | |
3184 | } | |
3185 | ||
3186 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3187 | may be NULL. */ | |
3188 | ||
3189 | static void | |
3190 | scan_reads_spill (read_info_t read_info, bitmap gen, bitmap kill) | |
3191 | { | |
3192 | while (read_info) | |
3193 | { | |
3194 | if (read_info->alias_set) | |
3195 | { | |
b8698a0f | 3196 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3197 | read_info->alias_set); |
3198 | if (index != 0) | |
3199 | { | |
3200 | if (kill) | |
3201 | bitmap_set_bit (kill, index); | |
3202 | bitmap_clear_bit (gen, index); | |
3203 | } | |
3204 | } | |
b8698a0f | 3205 | |
6fb5fa3c DB |
3206 | read_info = read_info->next; |
3207 | } | |
3208 | } | |
3209 | ||
3210 | ||
3211 | /* Return the insn in BB_INFO before the first wild read or if there | |
3212 | are no wild reads in the block, return the last insn. */ | |
3213 | ||
3214 | static insn_info_t | |
3215 | find_insn_before_first_wild_read (bb_info_t bb_info) | |
3216 | { | |
3217 | insn_info_t insn_info = bb_info->last_insn; | |
3218 | insn_info_t last_wild_read = NULL; | |
3219 | ||
3220 | while (insn_info) | |
3221 | { | |
3222 | if (insn_info->wild_read) | |
3223 | { | |
3224 | last_wild_read = insn_info->prev_insn; | |
3225 | /* Block starts with wild read. */ | |
3226 | if (!last_wild_read) | |
3227 | return NULL; | |
3228 | } | |
3229 | ||
3230 | insn_info = insn_info->prev_insn; | |
3231 | } | |
3232 | ||
3233 | if (last_wild_read) | |
3234 | return last_wild_read; | |
3235 | else | |
3236 | return bb_info->last_insn; | |
3237 | } | |
3238 | ||
3239 | ||
3240 | /* Scan the insns in BB_INFO starting at PTR and going to the top of | |
3241 | the block in order to build the gen and kill sets for the block. | |
3242 | We start at ptr which may be the last insn in the block or may be | |
3243 | the first insn with a wild read. In the latter case we are able to | |
3244 | skip the rest of the block because it just does not matter: | |
3245 | anything that happens is hidden by the wild read. */ | |
3246 | ||
3247 | static void | |
3248 | dse_step3_scan (bool for_spills, basic_block bb) | |
3249 | { | |
3250 | bb_info_t bb_info = bb_table[bb->index]; | |
3251 | insn_info_t insn_info; | |
3252 | ||
3253 | if (for_spills) | |
3254 | /* There are no wild reads in the spill case. */ | |
3255 | insn_info = bb_info->last_insn; | |
3256 | else | |
3257 | insn_info = find_insn_before_first_wild_read (bb_info); | |
b8698a0f | 3258 | |
6fb5fa3c DB |
3259 | /* In the spill case or in the no_spill case if there is no wild |
3260 | read in the block, we will need a kill set. */ | |
3261 | if (insn_info == bb_info->last_insn) | |
3262 | { | |
3263 | if (bb_info->kill) | |
3264 | bitmap_clear (bb_info->kill); | |
3265 | else | |
3266 | bb_info->kill = BITMAP_ALLOC (NULL); | |
3267 | } | |
b8698a0f | 3268 | else |
6fb5fa3c DB |
3269 | if (bb_info->kill) |
3270 | BITMAP_FREE (bb_info->kill); | |
3271 | ||
3272 | while (insn_info) | |
3273 | { | |
3274 | /* There may have been code deleted by the dce pass run before | |
3275 | this phase. */ | |
3276 | if (insn_info->insn && INSN_P (insn_info->insn)) | |
3277 | { | |
b8698a0f | 3278 | /* Process the read(s) last. */ |
6fb5fa3c DB |
3279 | if (for_spills) |
3280 | { | |
3281 | scan_stores_spill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3282 | scan_reads_spill (insn_info->read_rec, bb_info->gen, bb_info->kill); | |
3283 | } | |
3284 | else | |
3285 | { | |
3286 | scan_stores_nospill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3287 | scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill); | |
3288 | } | |
b8698a0f | 3289 | } |
6fb5fa3c DB |
3290 | |
3291 | insn_info = insn_info->prev_insn; | |
3292 | } | |
3293 | } | |
3294 | ||
3295 | ||
3296 | /* Set the gen set of the exit block, and also any block with no | |
3297 | successors that does not have a wild read. */ | |
3298 | ||
3299 | static void | |
3300 | dse_step3_exit_block_scan (bb_info_t bb_info) | |
3301 | { | |
3302 | /* The gen set is all 0's for the exit block except for the | |
3303 | frame_pointer_group. */ | |
b8698a0f | 3304 | |
6fb5fa3c DB |
3305 | if (stores_off_frame_dead_at_return) |
3306 | { | |
3307 | unsigned int i; | |
3308 | group_info_t group; | |
b8698a0f | 3309 | |
ac47786e | 3310 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c DB |
3311 | { |
3312 | if (group->process_globally && group->frame_related) | |
3313 | bitmap_ior_into (bb_info->gen, group->group_kill); | |
3314 | } | |
3315 | } | |
3316 | } | |
3317 | ||
3318 | ||
3319 | /* Find all of the blocks that are not backwards reachable from the | |
3320 | exit block or any block with no successors (BB). These are the | |
3321 | infinite loops or infinite self loops. These blocks will still | |
3322 | have their bits set in UNREACHABLE_BLOCKS. */ | |
3323 | ||
3324 | static void | |
3325 | mark_reachable_blocks (sbitmap unreachable_blocks, basic_block bb) | |
3326 | { | |
3327 | edge e; | |
3328 | edge_iterator ei; | |
3329 | ||
3330 | if (TEST_BIT (unreachable_blocks, bb->index)) | |
3331 | { | |
3332 | RESET_BIT (unreachable_blocks, bb->index); | |
3333 | FOR_EACH_EDGE (e, ei, bb->preds) | |
b8698a0f | 3334 | { |
6fb5fa3c | 3335 | mark_reachable_blocks (unreachable_blocks, e->src); |
b8698a0f | 3336 | } |
6fb5fa3c DB |
3337 | } |
3338 | } | |
3339 | ||
3340 | /* Build the transfer functions for the function. */ | |
3341 | ||
3342 | static void | |
3343 | dse_step3 (bool for_spills) | |
3344 | { | |
3345 | basic_block bb; | |
3346 | sbitmap unreachable_blocks = sbitmap_alloc (last_basic_block); | |
3347 | sbitmap_iterator sbi; | |
3348 | bitmap all_ones = NULL; | |
3349 | unsigned int i; | |
b8698a0f | 3350 | |
6fb5fa3c DB |
3351 | sbitmap_ones (unreachable_blocks); |
3352 | ||
3353 | FOR_ALL_BB (bb) | |
3354 | { | |
3355 | bb_info_t bb_info = bb_table[bb->index]; | |
3356 | if (bb_info->gen) | |
3357 | bitmap_clear (bb_info->gen); | |
3358 | else | |
3359 | bb_info->gen = BITMAP_ALLOC (NULL); | |
3360 | ||
3361 | if (bb->index == ENTRY_BLOCK) | |
3362 | ; | |
3363 | else if (bb->index == EXIT_BLOCK) | |
3364 | dse_step3_exit_block_scan (bb_info); | |
3365 | else | |
3366 | dse_step3_scan (for_spills, bb); | |
3367 | if (EDGE_COUNT (bb->succs) == 0) | |
3368 | mark_reachable_blocks (unreachable_blocks, bb); | |
3369 | ||
3370 | /* If this is the second time dataflow is run, delete the old | |
3371 | sets. */ | |
3372 | if (bb_info->in) | |
3373 | BITMAP_FREE (bb_info->in); | |
3374 | if (bb_info->out) | |
3375 | BITMAP_FREE (bb_info->out); | |
3376 | } | |
3377 | ||
3378 | /* For any block in an infinite loop, we must initialize the out set | |
3379 | to all ones. This could be expensive, but almost never occurs in | |
3380 | practice. However, it is common in regression tests. */ | |
3381 | EXECUTE_IF_SET_IN_SBITMAP (unreachable_blocks, 0, i, sbi) | |
3382 | { | |
3383 | if (bitmap_bit_p (all_blocks, i)) | |
3384 | { | |
3385 | bb_info_t bb_info = bb_table[i]; | |
3386 | if (!all_ones) | |
3387 | { | |
3388 | unsigned int j; | |
3389 | group_info_t group; | |
3390 | ||
3391 | all_ones = BITMAP_ALLOC (NULL); | |
ac47786e | 3392 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, j, group) |
6fb5fa3c DB |
3393 | bitmap_ior_into (all_ones, group->group_kill); |
3394 | } | |
3395 | if (!bb_info->out) | |
3396 | { | |
3397 | bb_info->out = BITMAP_ALLOC (NULL); | |
3398 | bitmap_copy (bb_info->out, all_ones); | |
3399 | } | |
3400 | } | |
3401 | } | |
3402 | ||
3403 | if (all_ones) | |
3404 | BITMAP_FREE (all_ones); | |
3405 | sbitmap_free (unreachable_blocks); | |
3406 | } | |
3407 | ||
3408 | ||
3409 | \f | |
3410 | /*---------------------------------------------------------------------------- | |
3411 | Fourth step. | |
3412 | ||
3413 | Solve the bitvector equations. | |
3414 | ----------------------------------------------------------------------------*/ | |
3415 | ||
3416 | ||
3417 | /* Confluence function for blocks with no successors. Create an out | |
3418 | set from the gen set of the exit block. This block logically has | |
3419 | the exit block as a successor. */ | |
3420 | ||
3421 | ||
3422 | ||
3423 | static void | |
3424 | dse_confluence_0 (basic_block bb) | |
3425 | { | |
3426 | bb_info_t bb_info = bb_table[bb->index]; | |
3427 | ||
3428 | if (bb->index == EXIT_BLOCK) | |
3429 | return; | |
3430 | ||
3431 | if (!bb_info->out) | |
3432 | { | |
3433 | bb_info->out = BITMAP_ALLOC (NULL); | |
3434 | bitmap_copy (bb_info->out, bb_table[EXIT_BLOCK]->gen); | |
3435 | } | |
3436 | } | |
3437 | ||
3438 | /* Propagate the information from the in set of the dest of E to the | |
3439 | out set of the src of E. If the various in or out sets are not | |
3440 | there, that means they are all ones. */ | |
3441 | ||
1a0f3fa1 | 3442 | static bool |
6fb5fa3c DB |
3443 | dse_confluence_n (edge e) |
3444 | { | |
3445 | bb_info_t src_info = bb_table[e->src->index]; | |
3446 | bb_info_t dest_info = bb_table[e->dest->index]; | |
3447 | ||
3448 | if (dest_info->in) | |
3449 | { | |
3450 | if (src_info->out) | |
3451 | bitmap_and_into (src_info->out, dest_info->in); | |
3452 | else | |
3453 | { | |
3454 | src_info->out = BITMAP_ALLOC (NULL); | |
3455 | bitmap_copy (src_info->out, dest_info->in); | |
3456 | } | |
3457 | } | |
1a0f3fa1 | 3458 | return true; |
6fb5fa3c DB |
3459 | } |
3460 | ||
3461 | ||
3462 | /* Propagate the info from the out to the in set of BB_INDEX's basic | |
b8698a0f | 3463 | block. There are three cases: |
6fb5fa3c DB |
3464 | |
3465 | 1) The block has no kill set. In this case the kill set is all | |
3466 | ones. It does not matter what the out set of the block is, none of | |
3467 | the info can reach the top. The only thing that reaches the top is | |
3468 | the gen set and we just copy the set. | |
3469 | ||
3470 | 2) There is a kill set but no out set and bb has successors. In | |
3471 | this case we just return. Eventually an out set will be created and | |
3472 | it is better to wait than to create a set of ones. | |
3473 | ||
3474 | 3) There is both a kill and out set. We apply the obvious transfer | |
3475 | function. | |
3476 | */ | |
3477 | ||
3478 | static bool | |
3479 | dse_transfer_function (int bb_index) | |
3480 | { | |
3481 | bb_info_t bb_info = bb_table[bb_index]; | |
3482 | ||
3483 | if (bb_info->kill) | |
3484 | { | |
3485 | if (bb_info->out) | |
3486 | { | |
3487 | /* Case 3 above. */ | |
3488 | if (bb_info->in) | |
b8698a0f | 3489 | return bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3490 | bb_info->out, bb_info->kill); |
3491 | else | |
3492 | { | |
3493 | bb_info->in = BITMAP_ALLOC (NULL); | |
b8698a0f | 3494 | bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3495 | bb_info->out, bb_info->kill); |
3496 | return true; | |
3497 | } | |
3498 | } | |
3499 | else | |
3500 | /* Case 2 above. */ | |
3501 | return false; | |
3502 | } | |
3503 | else | |
3504 | { | |
3505 | /* Case 1 above. If there is already an in set, nothing | |
3506 | happens. */ | |
3507 | if (bb_info->in) | |
3508 | return false; | |
3509 | else | |
3510 | { | |
3511 | bb_info->in = BITMAP_ALLOC (NULL); | |
3512 | bitmap_copy (bb_info->in, bb_info->gen); | |
3513 | return true; | |
3514 | } | |
3515 | } | |
3516 | } | |
3517 | ||
3518 | /* Solve the dataflow equations. */ | |
3519 | ||
3520 | static void | |
3521 | dse_step4 (void) | |
3522 | { | |
b8698a0f L |
3523 | df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0, |
3524 | dse_confluence_n, dse_transfer_function, | |
3525 | all_blocks, df_get_postorder (DF_BACKWARD), | |
6fb5fa3c DB |
3526 | df_get_n_blocks (DF_BACKWARD)); |
3527 | if (dump_file) | |
3528 | { | |
3529 | basic_block bb; | |
3530 | ||
3531 | fprintf (dump_file, "\n\n*** Global dataflow info after analysis.\n"); | |
3532 | FOR_ALL_BB (bb) | |
3533 | { | |
3534 | bb_info_t bb_info = bb_table[bb->index]; | |
3535 | ||
3536 | df_print_bb_index (bb, dump_file); | |
3537 | if (bb_info->in) | |
3538 | bitmap_print (dump_file, bb_info->in, " in: ", "\n"); | |
3539 | else | |
3540 | fprintf (dump_file, " in: *MISSING*\n"); | |
3541 | if (bb_info->gen) | |
3542 | bitmap_print (dump_file, bb_info->gen, " gen: ", "\n"); | |
3543 | else | |
3544 | fprintf (dump_file, " gen: *MISSING*\n"); | |
3545 | if (bb_info->kill) | |
3546 | bitmap_print (dump_file, bb_info->kill, " kill: ", "\n"); | |
3547 | else | |
3548 | fprintf (dump_file, " kill: *MISSING*\n"); | |
3549 | if (bb_info->out) | |
3550 | bitmap_print (dump_file, bb_info->out, " out: ", "\n"); | |
3551 | else | |
3552 | fprintf (dump_file, " out: *MISSING*\n\n"); | |
3553 | } | |
3554 | } | |
3555 | } | |
3556 | ||
3557 | ||
3558 | \f | |
3559 | /*---------------------------------------------------------------------------- | |
3560 | Fifth step. | |
3561 | ||
0d52bcc1 | 3562 | Delete the stores that can only be deleted using the global information. |
6fb5fa3c DB |
3563 | ----------------------------------------------------------------------------*/ |
3564 | ||
3565 | ||
3566 | static void | |
3567 | dse_step5_nospill (void) | |
3568 | { | |
3569 | basic_block bb; | |
3570 | FOR_EACH_BB (bb) | |
3571 | { | |
3572 | bb_info_t bb_info = bb_table[bb->index]; | |
3573 | insn_info_t insn_info = bb_info->last_insn; | |
3574 | bitmap v = bb_info->out; | |
3575 | ||
3576 | while (insn_info) | |
3577 | { | |
3578 | bool deleted = false; | |
3579 | if (dump_file && insn_info->insn) | |
3580 | { | |
3581 | fprintf (dump_file, "starting to process insn %d\n", | |
3582 | INSN_UID (insn_info->insn)); | |
3583 | bitmap_print (dump_file, v, " v: ", "\n"); | |
3584 | } | |
3585 | ||
3586 | /* There may have been code deleted by the dce pass run before | |
3587 | this phase. */ | |
b8698a0f | 3588 | if (insn_info->insn |
6fb5fa3c DB |
3589 | && INSN_P (insn_info->insn) |
3590 | && (!insn_info->cannot_delete) | |
3591 | && (!bitmap_empty_p (v))) | |
3592 | { | |
3593 | store_info_t store_info = insn_info->store_rec; | |
3594 | ||
3595 | /* Try to delete the current insn. */ | |
3596 | deleted = true; | |
b8698a0f | 3597 | |
6fb5fa3c DB |
3598 | /* Skip the clobbers. */ |
3599 | while (!store_info->is_set) | |
3600 | store_info = store_info->next; | |
3601 | ||
3602 | if (store_info->alias_set) | |
3603 | deleted = false; | |
3604 | else | |
3605 | { | |
3606 | HOST_WIDE_INT i; | |
b8698a0f | 3607 | group_info_t group_info |
6fb5fa3c | 3608 | = VEC_index (group_info_t, rtx_group_vec, store_info->group_id); |
b8698a0f | 3609 | |
6fb5fa3c DB |
3610 | for (i = store_info->begin; i < store_info->end; i++) |
3611 | { | |
3612 | int index = get_bitmap_index (group_info, i); | |
b8698a0f | 3613 | |
6fb5fa3c | 3614 | if (dump_file) |
b8698a0f | 3615 | fprintf (dump_file, "i = %d, index = %d\n", (int)i, index); |
6fb5fa3c DB |
3616 | if (index == 0 || !bitmap_bit_p (v, index)) |
3617 | { | |
3618 | if (dump_file) | |
b8698a0f | 3619 | fprintf (dump_file, "failing at i = %d\n", (int)i); |
6fb5fa3c DB |
3620 | deleted = false; |
3621 | break; | |
3622 | } | |
3623 | } | |
3624 | } | |
3625 | if (deleted) | |
3626 | { | |
3627 | if (dbg_cnt (dse)) | |
3628 | { | |
3629 | check_for_inc_dec (insn_info->insn); | |
3630 | delete_insn (insn_info->insn); | |
3631 | insn_info->insn = NULL; | |
3632 | globally_deleted++; | |
3633 | } | |
3634 | } | |
3635 | } | |
3636 | /* We do want to process the local info if the insn was | |
6ed3da00 | 3637 | deleted. For instance, if the insn did a wild read, we |
6fb5fa3c | 3638 | no longer need to trash the info. */ |
b8698a0f | 3639 | if (insn_info->insn |
6fb5fa3c DB |
3640 | && INSN_P (insn_info->insn) |
3641 | && (!deleted)) | |
3642 | { | |
3643 | scan_stores_nospill (insn_info->store_rec, v, NULL); | |
3644 | if (insn_info->wild_read) | |
3645 | { | |
3646 | if (dump_file) | |
3647 | fprintf (dump_file, "wild read\n"); | |
3648 | bitmap_clear (v); | |
3649 | } | |
d26c7090 ER |
3650 | else if (insn_info->read_rec |
3651 | || insn_info->non_frame_wild_read) | |
6fb5fa3c | 3652 | { |
d26c7090 | 3653 | if (dump_file && !insn_info->non_frame_wild_read) |
6fb5fa3c | 3654 | fprintf (dump_file, "regular read\n"); |
d26c7090 ER |
3655 | else if (dump_file) |
3656 | fprintf (dump_file, "non-frame wild read\n"); | |
6fb5fa3c DB |
3657 | scan_reads_nospill (insn_info, v, NULL); |
3658 | } | |
3659 | } | |
b8698a0f | 3660 | |
6fb5fa3c DB |
3661 | insn_info = insn_info->prev_insn; |
3662 | } | |
3663 | } | |
3664 | } | |
3665 | ||
3666 | ||
3667 | static void | |
3668 | dse_step5_spill (void) | |
3669 | { | |
3670 | basic_block bb; | |
3671 | FOR_EACH_BB (bb) | |
3672 | { | |
3673 | bb_info_t bb_info = bb_table[bb->index]; | |
3674 | insn_info_t insn_info = bb_info->last_insn; | |
3675 | bitmap v = bb_info->out; | |
3676 | ||
3677 | while (insn_info) | |
3678 | { | |
3679 | bool deleted = false; | |
3680 | /* There may have been code deleted by the dce pass run before | |
3681 | this phase. */ | |
b8698a0f | 3682 | if (insn_info->insn |
6fb5fa3c DB |
3683 | && INSN_P (insn_info->insn) |
3684 | && (!insn_info->cannot_delete) | |
3685 | && (!bitmap_empty_p (v))) | |
3686 | { | |
3687 | /* Try to delete the current insn. */ | |
3688 | store_info_t store_info = insn_info->store_rec; | |
3689 | deleted = true; | |
b8698a0f | 3690 | |
6fb5fa3c DB |
3691 | while (store_info) |
3692 | { | |
3693 | if (store_info->alias_set) | |
3694 | { | |
b8698a0f | 3695 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3696 | store_info->alias_set); |
3697 | if (index == 0 || !bitmap_bit_p (v, index)) | |
3698 | { | |
3699 | deleted = false; | |
3700 | break; | |
3701 | } | |
3702 | } | |
b8698a0f | 3703 | else |
6fb5fa3c DB |
3704 | deleted = false; |
3705 | store_info = store_info->next; | |
3706 | } | |
3707 | if (deleted && dbg_cnt (dse)) | |
3708 | { | |
3709 | if (dump_file) | |
b8698a0f | 3710 | fprintf (dump_file, "Spill deleting insn %d\n", |
6fb5fa3c DB |
3711 | INSN_UID (insn_info->insn)); |
3712 | check_for_inc_dec (insn_info->insn); | |
3713 | delete_insn (insn_info->insn); | |
3714 | spill_deleted++; | |
3715 | insn_info->insn = NULL; | |
3716 | } | |
3717 | } | |
b8698a0f L |
3718 | |
3719 | if (insn_info->insn | |
6fb5fa3c DB |
3720 | && INSN_P (insn_info->insn) |
3721 | && (!deleted)) | |
3722 | { | |
3723 | scan_stores_spill (insn_info->store_rec, v, NULL); | |
3724 | scan_reads_spill (insn_info->read_rec, v, NULL); | |
3725 | } | |
b8698a0f | 3726 | |
6fb5fa3c DB |
3727 | insn_info = insn_info->prev_insn; |
3728 | } | |
3729 | } | |
3730 | } | |
3731 | ||
3732 | ||
3733 | \f | |
3734 | /*---------------------------------------------------------------------------- | |
3735 | Sixth step. | |
3736 | ||
8dd5516b JJ |
3737 | Delete stores made redundant by earlier stores (which store the same |
3738 | value) that couldn't be eliminated. | |
3739 | ----------------------------------------------------------------------------*/ | |
3740 | ||
3741 | static void | |
3742 | dse_step6 (void) | |
3743 | { | |
3744 | basic_block bb; | |
3745 | ||
3746 | FOR_ALL_BB (bb) | |
3747 | { | |
3748 | bb_info_t bb_info = bb_table[bb->index]; | |
3749 | insn_info_t insn_info = bb_info->last_insn; | |
3750 | ||
3751 | while (insn_info) | |
3752 | { | |
3753 | /* There may have been code deleted by the dce pass run before | |
3754 | this phase. */ | |
3755 | if (insn_info->insn | |
3756 | && INSN_P (insn_info->insn) | |
3757 | && !insn_info->cannot_delete) | |
3758 | { | |
3759 | store_info_t s_info = insn_info->store_rec; | |
3760 | ||
3761 | while (s_info && !s_info->is_set) | |
3762 | s_info = s_info->next; | |
3763 | if (s_info | |
3764 | && s_info->redundant_reason | |
3765 | && s_info->redundant_reason->insn | |
3766 | && INSN_P (s_info->redundant_reason->insn)) | |
3767 | { | |
3768 | rtx rinsn = s_info->redundant_reason->insn; | |
3769 | if (dump_file) | |
3770 | fprintf (dump_file, "Locally deleting insn %d " | |
3771 | "because insn %d stores the " | |
3772 | "same value and couldn't be " | |
3773 | "eliminated\n", | |
3774 | INSN_UID (insn_info->insn), | |
3775 | INSN_UID (rinsn)); | |
3776 | delete_dead_store_insn (insn_info); | |
3777 | } | |
3778 | } | |
3779 | insn_info = insn_info->prev_insn; | |
3780 | } | |
3781 | } | |
3782 | } | |
3783 | \f | |
3784 | /*---------------------------------------------------------------------------- | |
3785 | Seventh step. | |
3786 | ||
b8698a0f | 3787 | Destroy everything left standing. |
6fb5fa3c DB |
3788 | ----------------------------------------------------------------------------*/ |
3789 | ||
b8698a0f | 3790 | static void |
8dd5516b | 3791 | dse_step7 (bool global_done) |
6fb5fa3c DB |
3792 | { |
3793 | unsigned int i; | |
3794 | group_info_t group; | |
3795 | basic_block bb; | |
b8698a0f | 3796 | |
ac47786e | 3797 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c | 3798 | { |
370f38e8 KZ |
3799 | free (group->offset_map_n); |
3800 | free (group->offset_map_p); | |
3801 | BITMAP_FREE (group->store1_n); | |
3802 | BITMAP_FREE (group->store1_p); | |
3803 | BITMAP_FREE (group->store2_n); | |
3804 | BITMAP_FREE (group->store2_p); | |
d26c7090 ER |
3805 | BITMAP_FREE (group->escaped_n); |
3806 | BITMAP_FREE (group->escaped_p); | |
370f38e8 | 3807 | BITMAP_FREE (group->group_kill); |
6fb5fa3c DB |
3808 | } |
3809 | ||
370f38e8 KZ |
3810 | if (global_done) |
3811 | FOR_ALL_BB (bb) | |
3812 | { | |
3813 | bb_info_t bb_info = bb_table[bb->index]; | |
3814 | BITMAP_FREE (bb_info->gen); | |
3815 | if (bb_info->kill) | |
3816 | BITMAP_FREE (bb_info->kill); | |
3817 | if (bb_info->in) | |
3818 | BITMAP_FREE (bb_info->in); | |
3819 | if (bb_info->out) | |
3820 | BITMAP_FREE (bb_info->out); | |
3821 | } | |
3822 | ||
6fb5fa3c DB |
3823 | if (clear_alias_sets) |
3824 | { | |
3825 | BITMAP_FREE (clear_alias_sets); | |
3826 | BITMAP_FREE (disqualified_clear_alias_sets); | |
3827 | free_alloc_pool (clear_alias_mode_pool); | |
3828 | htab_delete (clear_alias_mode_table); | |
3829 | } | |
3830 | ||
3831 | end_alias_analysis (); | |
3832 | free (bb_table); | |
3833 | htab_delete (rtx_group_table); | |
3834 | VEC_free (group_info_t, heap, rtx_group_vec); | |
3835 | BITMAP_FREE (all_blocks); | |
3836 | BITMAP_FREE (scratch); | |
d26c7090 | 3837 | BITMAP_FREE (kill_on_calls); |
6fb5fa3c DB |
3838 | |
3839 | free_alloc_pool (rtx_store_info_pool); | |
3840 | free_alloc_pool (read_info_pool); | |
3841 | free_alloc_pool (insn_info_pool); | |
3842 | free_alloc_pool (bb_info_pool); | |
3843 | free_alloc_pool (rtx_group_info_pool); | |
3844 | free_alloc_pool (deferred_change_pool); | |
3845 | } | |
3846 | ||
3847 | ||
6fb5fa3c DB |
3848 | /* ------------------------------------------------------------------------- |
3849 | DSE | |
3850 | ------------------------------------------------------------------------- */ | |
3851 | ||
3852 | /* Callback for running pass_rtl_dse. */ | |
3853 | ||
3854 | static unsigned int | |
3855 | rest_of_handle_dse (void) | |
3856 | { | |
3857 | bool did_global = false; | |
3858 | ||
3859 | df_set_flags (DF_DEFER_INSN_RESCAN); | |
3860 | ||
02b47899 KZ |
3861 | /* Need the notes since we must track live hardregs in the forwards |
3862 | direction. */ | |
3863 | df_note_add_problem (); | |
3864 | df_analyze (); | |
3865 | ||
6fb5fa3c DB |
3866 | dse_step0 (); |
3867 | dse_step1 (); | |
3868 | dse_step2_init (); | |
3869 | if (dse_step2_nospill ()) | |
3870 | { | |
3871 | df_set_flags (DF_LR_RUN_DCE); | |
3872 | df_analyze (); | |
3873 | did_global = true; | |
3874 | if (dump_file) | |
3875 | fprintf (dump_file, "doing global processing\n"); | |
3876 | dse_step3 (false); | |
3877 | dse_step4 (); | |
3878 | dse_step5_nospill (); | |
3879 | } | |
3880 | ||
3881 | /* For the instance of dse that runs after reload, we make a special | |
3882 | pass to process the spills. These are special in that they are | |
3883 | totally transparent, i.e, there is no aliasing issues that need | |
3884 | to be considered. This means that the wild reads that kill | |
b8698a0f | 3885 | everything else do not apply here. */ |
6fb5fa3c DB |
3886 | if (clear_alias_sets && dse_step2_spill ()) |
3887 | { | |
3888 | if (!did_global) | |
3889 | { | |
3890 | df_set_flags (DF_LR_RUN_DCE); | |
3891 | df_analyze (); | |
3892 | } | |
3893 | did_global = true; | |
3894 | if (dump_file) | |
3895 | fprintf (dump_file, "doing global spill processing\n"); | |
3896 | dse_step3 (true); | |
3897 | dse_step4 (); | |
3898 | dse_step5_spill (); | |
3899 | } | |
8dd5516b JJ |
3900 | |
3901 | dse_step6 (); | |
3902 | dse_step7 (did_global); | |
6fb5fa3c DB |
3903 | |
3904 | if (dump_file) | |
3905 | fprintf (dump_file, "dse: local deletions = %d, global deletions = %d, spill deletions = %d\n", | |
3906 | locally_deleted, globally_deleted, spill_deleted); | |
3907 | return 0; | |
3908 | } | |
3909 | ||
3910 | static bool | |
3911 | gate_dse (void) | |
3912 | { | |
7d817ebc DE |
3913 | return gate_dse1 () || gate_dse2 (); |
3914 | } | |
3915 | ||
3916 | static bool | |
3917 | gate_dse1 (void) | |
3918 | { | |
3919 | return optimize > 0 && flag_dse | |
3920 | && dbg_cnt (dse1); | |
3921 | } | |
3922 | ||
3923 | static bool | |
3924 | gate_dse2 (void) | |
3925 | { | |
3926 | return optimize > 0 && flag_dse | |
3927 | && dbg_cnt (dse2); | |
6fb5fa3c DB |
3928 | } |
3929 | ||
8ddbbcae | 3930 | struct rtl_opt_pass pass_rtl_dse1 = |
6fb5fa3c | 3931 | { |
8ddbbcae JH |
3932 | { |
3933 | RTL_PASS, | |
6fb5fa3c | 3934 | "dse1", /* name */ |
7d817ebc | 3935 | gate_dse1, /* gate */ |
6fb5fa3c DB |
3936 | rest_of_handle_dse, /* execute */ |
3937 | NULL, /* sub */ | |
3938 | NULL, /* next */ | |
3939 | 0, /* static_pass_number */ | |
3940 | TV_DSE1, /* tv_id */ | |
3941 | 0, /* properties_required */ | |
3942 | 0, /* properties_provided */ | |
3943 | 0, /* properties_destroyed */ | |
3944 | 0, /* todo_flags_start */ | |
a36b8a1e | 3945 | TODO_df_finish | TODO_verify_rtl_sharing | |
8ddbbcae JH |
3946 | TODO_ggc_collect /* todo_flags_finish */ |
3947 | } | |
6fb5fa3c DB |
3948 | }; |
3949 | ||
8ddbbcae | 3950 | struct rtl_opt_pass pass_rtl_dse2 = |
6fb5fa3c | 3951 | { |
8ddbbcae JH |
3952 | { |
3953 | RTL_PASS, | |
6fb5fa3c | 3954 | "dse2", /* name */ |
7d817ebc | 3955 | gate_dse2, /* gate */ |
6fb5fa3c DB |
3956 | rest_of_handle_dse, /* execute */ |
3957 | NULL, /* sub */ | |
3958 | NULL, /* next */ | |
3959 | 0, /* static_pass_number */ | |
3960 | TV_DSE2, /* tv_id */ | |
3961 | 0, /* properties_required */ | |
3962 | 0, /* properties_provided */ | |
3963 | 0, /* properties_destroyed */ | |
3964 | 0, /* todo_flags_start */ | |
a36b8a1e | 3965 | TODO_df_finish | TODO_verify_rtl_sharing | |
8ddbbcae JH |
3966 | TODO_ggc_collect /* todo_flags_finish */ |
3967 | } | |
6fb5fa3c | 3968 | }; |