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6fb5fa3c | 1 | /* RTL dead store elimination. |
757e8ba2 | 2 | Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 |
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" | |
703c8606 | 29 | #include "hash-table.h" |
6fb5fa3c DB |
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" | |
9e582b1d | 36 | #include "regset.h" |
6fb5fa3c DB |
37 | #include "flags.h" |
38 | #include "df.h" | |
39 | #include "cselib.h" | |
6fb5fa3c DB |
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" | |
8660aaae | 46 | #include "optabs.h" |
6fb5fa3c | 47 | #include "dbgcnt.h" |
67d0afe9 | 48 | #include "target.h" |
dabd47e7 | 49 | #include "params.h" |
6f4185d7 | 50 | #include "tree-flow.h" /* for may_be_aliased */ |
6fb5fa3c DB |
51 | |
52 | /* This file contains three techniques for performing Dead Store | |
b8698a0f | 53 | Elimination (dse). |
6fb5fa3c DB |
54 | |
55 | * The first technique performs dse locally on any base address. It | |
56 | is based on the cselib which is a local value numbering technique. | |
57 | This technique is local to a basic block but deals with a fairly | |
58 | general addresses. | |
b8698a0f | 59 | |
6fb5fa3c DB |
60 | * The second technique performs dse globally but is restricted to |
61 | base addresses that are either constant or are relative to the | |
62 | frame_pointer. | |
63 | ||
64 | * The third technique, (which is only done after register allocation) | |
65 | processes the spill spill slots. This differs from the second | |
66 | technique because it takes advantage of the fact that spilling is | |
67 | completely free from the effects of aliasing. | |
68 | ||
69 | Logically, dse is a backwards dataflow problem. A store can be | |
70 | deleted if it if cannot be reached in the backward direction by any | |
71 | use of the value being stored. However, the local technique uses a | |
72 | forwards scan of the basic block because cselib requires that the | |
73 | block be processed in that order. | |
74 | ||
75 | The pass is logically broken into 7 steps: | |
76 | ||
77 | 0) Initialization. | |
78 | ||
79 | 1) The local algorithm, as well as scanning the insns for the two | |
80 | global algorithms. | |
81 | ||
82 | 2) Analysis to see if the global algs are necessary. In the case | |
83 | of stores base on a constant address, there must be at least two | |
84 | stores to that address, to make it possible to delete some of the | |
85 | stores. In the case of stores off of the frame or spill related | |
86 | stores, only one store to an address is necessary because those | |
87 | stores die at the end of the function. | |
88 | ||
b8698a0f | 89 | 3) Set up the global dataflow equations based on processing the |
6fb5fa3c DB |
90 | info parsed in the first step. |
91 | ||
92 | 4) Solve the dataflow equations. | |
93 | ||
94 | 5) Delete the insns that the global analysis has indicated are | |
95 | unnecessary. | |
96 | ||
073a8998 | 97 | 6) Delete insns that store the same value as preceding store |
8dd5516b JJ |
98 | where the earlier store couldn't be eliminated. |
99 | ||
100 | 7) Cleanup. | |
6fb5fa3c DB |
101 | |
102 | This step uses cselib and canon_rtx to build the largest expression | |
103 | possible for each address. This pass is a forwards pass through | |
104 | each basic block. From the point of view of the global technique, | |
105 | the first pass could examine a block in either direction. The | |
0d52bcc1 | 106 | forwards ordering is to accommodate cselib. |
6fb5fa3c | 107 | |
5ef0b50d | 108 | We make a simplifying assumption: addresses fall into four broad |
6fb5fa3c DB |
109 | categories: |
110 | ||
111 | 1) base has rtx_varies_p == false, offset is constant. | |
112 | 2) base has rtx_varies_p == false, offset variable. | |
113 | 3) base has rtx_varies_p == true, offset constant. | |
114 | 4) base has rtx_varies_p == true, offset variable. | |
115 | ||
116 | The local passes are able to process all 4 kinds of addresses. The | |
5ef0b50d | 117 | global pass only handles 1). |
6fb5fa3c DB |
118 | |
119 | The global problem is formulated as follows: | |
120 | ||
121 | A store, S1, to address A, where A is not relative to the stack | |
122 | frame, can be eliminated if all paths from S1 to the end of the | |
5ef0b50d | 123 | function contain another store to A before a read to A. |
6fb5fa3c DB |
124 | |
125 | If the address A is relative to the stack frame, a store S2 to A | |
5ef0b50d | 126 | can be eliminated if there are no paths from S2 that reach the |
6fb5fa3c | 127 | end of the function that read A before another store to A. In |
5ef0b50d | 128 | this case S2 can be deleted if there are paths from S2 to the |
6fb5fa3c DB |
129 | end of the function that have no reads or writes to A. This |
130 | second case allows stores to the stack frame to be deleted that | |
131 | would otherwise die when the function returns. This cannot be | |
132 | done if stores_off_frame_dead_at_return is not true. See the doc | |
133 | for that variable for when this variable is false. | |
134 | ||
135 | The global problem is formulated as a backwards set union | |
136 | dataflow problem where the stores are the gens and reads are the | |
137 | kills. Set union problems are rare and require some special | |
138 | handling given our representation of bitmaps. A straightforward | |
5ef0b50d | 139 | implementation requires a lot of bitmaps filled with 1s. |
6fb5fa3c DB |
140 | These are expensive and cumbersome in our bitmap formulation so |
141 | care has been taken to avoid large vectors filled with 1s. See | |
142 | the comments in bb_info and in the dataflow confluence functions | |
b8698a0f | 143 | for details. |
6fb5fa3c DB |
144 | |
145 | There are two places for further enhancements to this algorithm: | |
b8698a0f | 146 | |
6fb5fa3c DB |
147 | 1) The original dse which was embedded in a pass called flow also |
148 | did local address forwarding. For example in | |
149 | ||
150 | A <- r100 | |
151 | ... <- A | |
152 | ||
153 | flow would replace the right hand side of the second insn with a | |
6ed3da00 | 154 | reference to r100. Most of the information is available to add this |
6fb5fa3c DB |
155 | to this pass. It has not done it because it is a lot of work in |
156 | the case that either r100 is assigned to between the first and | |
157 | second insn and/or the second insn is a load of part of the value | |
158 | stored by the first insn. | |
159 | ||
160 | insn 5 in gcc.c-torture/compile/990203-1.c simple case. | |
161 | insn 15 in gcc.c-torture/execute/20001017-2.c simple case. | |
162 | insn 25 in gcc.c-torture/execute/20001026-1.c simple case. | |
163 | insn 44 in gcc.c-torture/execute/20010910-1.c simple case. | |
164 | ||
165 | 2) The cleaning up of spill code is quite profitable. It currently | |
166 | depends on reading tea leaves and chicken entrails left by reload. | |
167 | This pass depends on reload creating a singleton alias set for each | |
168 | spill slot and telling the next dse pass which of these alias sets | |
169 | are the singletons. Rather than analyze the addresses of the | |
170 | spills, dse's spill processing just does analysis of the loads and | |
171 | stores that use those alias sets. There are three cases where this | |
172 | falls short: | |
173 | ||
174 | a) Reload sometimes creates the slot for one mode of access, and | |
175 | then inserts loads and/or stores for a smaller mode. In this | |
176 | case, the current code just punts on the slot. The proper thing | |
177 | to do is to back out and use one bit vector position for each | |
178 | byte of the entity associated with the slot. This depends on | |
179 | KNOWING that reload always generates the accesses for each of the | |
180 | bytes in some canonical (read that easy to understand several | |
181 | passes after reload happens) way. | |
182 | ||
183 | b) Reload sometimes decides that spill slot it allocated was not | |
184 | large enough for the mode and goes back and allocates more slots | |
185 | with the same mode and alias set. The backout in this case is a | |
186 | little more graceful than (a). In this case the slot is unmarked | |
187 | as being a spill slot and if final address comes out to be based | |
b8698a0f | 188 | off the frame pointer, the global algorithm handles this slot. |
6fb5fa3c DB |
189 | |
190 | c) For any pass that may prespill, there is currently no | |
191 | mechanism to tell the dse pass that the slot being used has the | |
192 | special properties that reload uses. It may be that all that is | |
0d52bcc1 | 193 | required is to have those passes make the same calls that reload |
6fb5fa3c DB |
194 | does, assuming that the alias sets can be manipulated in the same |
195 | way. */ | |
196 | ||
197 | /* There are limits to the size of constant offsets we model for the | |
198 | global problem. There are certainly test cases, that exceed this | |
199 | limit, however, it is unlikely that there are important programs | |
200 | that really have constant offsets this size. */ | |
201 | #define MAX_OFFSET (64 * 1024) | |
202 | ||
3f9b14ff SB |
203 | /* Obstack for the DSE dataflow bitmaps. We don't want to put these |
204 | on the default obstack because these bitmaps can grow quite large | |
205 | (~2GB for the small (!) test case of PR54146) and we'll hold on to | |
206 | all that memory until the end of the compiler run. | |
207 | As a bonus, delete_tree_live_info can destroy all the bitmaps by just | |
208 | releasing the whole obstack. */ | |
209 | static bitmap_obstack dse_bitmap_obstack; | |
210 | ||
211 | /* Obstack for other data. As for above: Kinda nice to be able to | |
212 | throw it all away at the end in one big sweep. */ | |
213 | static struct obstack dse_obstack; | |
214 | ||
215 | /* Scratch bitmap for cselib's cselib_expand_value_rtx. */ | |
6fb5fa3c | 216 | static bitmap scratch = NULL; |
3f9b14ff | 217 | |
6fb5fa3c DB |
218 | struct insn_info; |
219 | ||
220 | /* This structure holds information about a candidate store. */ | |
b8698a0f | 221 | struct store_info |
6fb5fa3c DB |
222 | { |
223 | ||
224 | /* False means this is a clobber. */ | |
225 | bool is_set; | |
226 | ||
8dd5516b JJ |
227 | /* False if a single HOST_WIDE_INT bitmap is used for positions_needed. */ |
228 | bool is_large; | |
229 | ||
6fb5fa3c DB |
230 | /* The id of the mem group of the base address. If rtx_varies_p is |
231 | true, this is -1. Otherwise, it is the index into the group | |
232 | table. */ | |
233 | int group_id; | |
b8698a0f | 234 | |
6fb5fa3c DB |
235 | /* This is the cselib value. */ |
236 | cselib_val *cse_base; | |
237 | ||
238 | /* This canonized mem. */ | |
239 | rtx mem; | |
240 | ||
6216f94e | 241 | /* Canonized MEM address for use by canon_true_dependence. */ |
6fb5fa3c DB |
242 | rtx mem_addr; |
243 | ||
244 | /* If this is non-zero, it is the alias set of a spill location. */ | |
4862826d | 245 | alias_set_type alias_set; |
6fb5fa3c DB |
246 | |
247 | /* The offset of the first and byte before the last byte associated | |
248 | with the operation. */ | |
8dd5516b JJ |
249 | HOST_WIDE_INT begin, end; |
250 | ||
251 | union | |
252 | { | |
253 | /* A bitmask as wide as the number of bytes in the word that | |
254 | contains a 1 if the byte may be needed. The store is unused if | |
255 | all of the bits are 0. This is used if IS_LARGE is false. */ | |
256 | unsigned HOST_WIDE_INT small_bitmask; | |
257 | ||
258 | struct | |
259 | { | |
260 | /* A bitmap with one bit per byte. Cleared bit means the position | |
261 | is needed. Used if IS_LARGE is false. */ | |
dc491a25 | 262 | bitmap bmap; |
6fb5fa3c | 263 | |
8dd5516b JJ |
264 | /* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is |
265 | equal to END - BEGIN, the whole store is unused. */ | |
266 | int count; | |
267 | } large; | |
268 | } positions_needed; | |
6fb5fa3c DB |
269 | |
270 | /* The next store info for this insn. */ | |
271 | struct store_info *next; | |
272 | ||
273 | /* The right hand side of the store. This is used if there is a | |
274 | subsequent reload of the mems address somewhere later in the | |
275 | basic block. */ | |
8dd5516b JJ |
276 | rtx rhs; |
277 | ||
278 | /* If rhs is or holds a constant, this contains that constant, | |
279 | otherwise NULL. */ | |
280 | rtx const_rhs; | |
281 | ||
282 | /* Set if this store stores the same constant value as REDUNDANT_REASON | |
283 | insn stored. These aren't eliminated early, because doing that | |
284 | might prevent the earlier larger store to be eliminated. */ | |
285 | struct insn_info *redundant_reason; | |
6fb5fa3c DB |
286 | }; |
287 | ||
4fe663b0 L |
288 | /* Return a bitmask with the first N low bits set. */ |
289 | ||
290 | static unsigned HOST_WIDE_INT | |
291 | lowpart_bitmask (int n) | |
292 | { | |
293 | unsigned HOST_WIDE_INT mask = ~(unsigned HOST_WIDE_INT) 0; | |
294 | return mask >> (HOST_BITS_PER_WIDE_INT - n); | |
295 | } | |
296 | ||
6fb5fa3c DB |
297 | typedef struct store_info *store_info_t; |
298 | static alloc_pool cse_store_info_pool; | |
299 | static alloc_pool rtx_store_info_pool; | |
300 | ||
301 | /* This structure holds information about a load. These are only | |
302 | built for rtx bases. */ | |
b8698a0f | 303 | struct read_info |
6fb5fa3c DB |
304 | { |
305 | /* The id of the mem group of the base address. */ | |
306 | int group_id; | |
307 | ||
308 | /* If this is non-zero, it is the alias set of a spill location. */ | |
4862826d | 309 | alias_set_type alias_set; |
6fb5fa3c DB |
310 | |
311 | /* The offset of the first and byte after the last byte associated | |
312 | with the operation. If begin == end == 0, the read did not have | |
313 | a constant offset. */ | |
314 | int begin, end; | |
315 | ||
316 | /* The mem being read. */ | |
317 | rtx mem; | |
318 | ||
319 | /* The next read_info for this insn. */ | |
320 | struct read_info *next; | |
321 | }; | |
322 | typedef struct read_info *read_info_t; | |
323 | static alloc_pool read_info_pool; | |
324 | ||
325 | ||
326 | /* One of these records is created for each insn. */ | |
327 | ||
b8698a0f | 328 | struct insn_info |
6fb5fa3c DB |
329 | { |
330 | /* Set true if the insn contains a store but the insn itself cannot | |
331 | be deleted. This is set if the insn is a parallel and there is | |
332 | more than one non dead output or if the insn is in some way | |
333 | volatile. */ | |
334 | bool cannot_delete; | |
335 | ||
336 | /* This field is only used by the global algorithm. It is set true | |
337 | if the insn contains any read of mem except for a (1). This is | |
338 | also set if the insn is a call or has a clobber mem. If the insn | |
339 | contains a wild read, the use_rec will be null. */ | |
340 | bool wild_read; | |
341 | ||
d26c7090 ER |
342 | /* This is true only for CALL instructions which could potentially read |
343 | any non-frame memory location. This field is used by the global | |
344 | algorithm. */ | |
345 | bool non_frame_wild_read; | |
346 | ||
50f0f366 EB |
347 | /* This field is only used for the processing of const functions. |
348 | These functions cannot read memory, but they can read the stack | |
64520bdc EB |
349 | because that is where they may get their parms. We need to be |
350 | this conservative because, like the store motion pass, we don't | |
351 | consider CALL_INSN_FUNCTION_USAGE when processing call insns. | |
352 | Moreover, we need to distinguish two cases: | |
353 | 1. Before reload (register elimination), the stores related to | |
354 | outgoing arguments are stack pointer based and thus deemed | |
355 | of non-constant base in this pass. This requires special | |
356 | handling but also means that the frame pointer based stores | |
357 | need not be killed upon encountering a const function call. | |
358 | 2. After reload, the stores related to outgoing arguments can be | |
359 | either stack pointer or hard frame pointer based. This means | |
360 | that we have no other choice than also killing all the frame | |
361 | pointer based stores upon encountering a const function call. | |
362 | This field is set after reload for const function calls. Having | |
363 | this set is less severe than a wild read, it just means that all | |
364 | the frame related stores are killed rather than all the stores. */ | |
365 | bool frame_read; | |
366 | ||
367 | /* This field is only used for the processing of const functions. | |
368 | It is set if the insn may contain a stack pointer based store. */ | |
50f0f366 | 369 | bool stack_pointer_based; |
6fb5fa3c DB |
370 | |
371 | /* This is true if any of the sets within the store contains a | |
372 | cselib base. Such stores can only be deleted by the local | |
373 | algorithm. */ | |
374 | bool contains_cselib_groups; | |
375 | ||
376 | /* The insn. */ | |
377 | rtx insn; | |
378 | ||
379 | /* The list of mem sets or mem clobbers that are contained in this | |
380 | insn. If the insn is deletable, it contains only one mem set. | |
381 | But it could also contain clobbers. Insns that contain more than | |
382 | one mem set are not deletable, but each of those mems are here in | |
6ed3da00 | 383 | order to provide info to delete other insns. */ |
6fb5fa3c DB |
384 | store_info_t store_rec; |
385 | ||
386 | /* The linked list of mem uses in this insn. Only the reads from | |
387 | rtx bases are listed here. The reads to cselib bases are | |
388 | completely processed during the first scan and so are never | |
389 | created. */ | |
390 | read_info_t read_rec; | |
391 | ||
9e582b1d JR |
392 | /* The live fixed registers. We assume only fixed registers can |
393 | cause trouble by being clobbered from an expanded pattern; | |
394 | storing only the live fixed registers (rather than all registers) | |
395 | means less memory needs to be allocated / copied for the individual | |
396 | stores. */ | |
397 | regset fixed_regs_live; | |
398 | ||
6fb5fa3c DB |
399 | /* The prev insn in the basic block. */ |
400 | struct insn_info * prev_insn; | |
401 | ||
402 | /* The linked list of insns that are in consideration for removal in | |
073a8998 | 403 | the forwards pass through the basic block. This pointer may be |
6fb5fa3c | 404 | trash as it is not cleared when a wild read occurs. The only |
fa10beec | 405 | time it is guaranteed to be correct is when the traversal starts |
6fb5fa3c DB |
406 | at active_local_stores. */ |
407 | struct insn_info * next_local_store; | |
408 | }; | |
409 | ||
410 | typedef struct insn_info *insn_info_t; | |
411 | static alloc_pool insn_info_pool; | |
412 | ||
413 | /* The linked list of stores that are under consideration in this | |
b8698a0f | 414 | basic block. */ |
6fb5fa3c | 415 | static insn_info_t active_local_stores; |
dabd47e7 | 416 | static int active_local_stores_len; |
6fb5fa3c | 417 | |
b8698a0f | 418 | struct bb_info |
6fb5fa3c DB |
419 | { |
420 | ||
421 | /* Pointer to the insn info for the last insn in the block. These | |
422 | are linked so this is how all of the insns are reached. During | |
423 | scanning this is the current insn being scanned. */ | |
424 | insn_info_t last_insn; | |
425 | ||
426 | /* The info for the global dataflow problem. */ | |
427 | ||
428 | ||
429 | /* This is set if the transfer function should and in the wild_read | |
430 | bitmap before applying the kill and gen sets. That vector knocks | |
431 | out most of the bits in the bitmap and thus speeds up the | |
432 | operations. */ | |
433 | bool apply_wild_read; | |
434 | ||
02b47899 KZ |
435 | /* The following 4 bitvectors hold information about which positions |
436 | of which stores are live or dead. They are indexed by | |
437 | get_bitmap_index. */ | |
438 | ||
6fb5fa3c DB |
439 | /* The set of store positions that exist in this block before a wild read. */ |
440 | bitmap gen; | |
b8698a0f | 441 | |
6fb5fa3c DB |
442 | /* The set of load positions that exist in this block above the |
443 | same position of a store. */ | |
444 | bitmap kill; | |
445 | ||
446 | /* The set of stores that reach the top of the block without being | |
447 | killed by a read. | |
448 | ||
449 | Do not represent the in if it is all ones. Note that this is | |
450 | what the bitvector should logically be initialized to for a set | |
451 | intersection problem. However, like the kill set, this is too | |
452 | expensive. So initially, the in set will only be created for the | |
453 | exit block and any block that contains a wild read. */ | |
454 | bitmap in; | |
455 | ||
456 | /* The set of stores that reach the bottom of the block from it's | |
457 | successors. | |
458 | ||
459 | Do not represent the in if it is all ones. Note that this is | |
460 | what the bitvector should logically be initialized to for a set | |
461 | intersection problem. However, like the kill and in set, this is | |
462 | too expensive. So what is done is that the confluence operator | |
463 | just initializes the vector from one of the out sets of the | |
464 | successors of the block. */ | |
465 | bitmap out; | |
02b47899 KZ |
466 | |
467 | /* The following bitvector is indexed by the reg number. It | |
468 | contains the set of regs that are live at the current instruction | |
469 | being processed. While it contains info for all of the | |
9e582b1d JR |
470 | registers, only the hard registers are actually examined. It is used |
471 | to assure that shift and/or add sequences that are inserted do not | |
073a8998 | 472 | accidentally clobber live hard regs. */ |
02b47899 | 473 | bitmap regs_live; |
6fb5fa3c DB |
474 | }; |
475 | ||
476 | typedef struct bb_info *bb_info_t; | |
477 | static alloc_pool bb_info_pool; | |
478 | ||
479 | /* Table to hold all bb_infos. */ | |
480 | static bb_info_t *bb_table; | |
481 | ||
482 | /* There is a group_info for each rtx base that is used to reference | |
483 | memory. There are also not many of the rtx bases because they are | |
484 | very limited in scope. */ | |
485 | ||
b8698a0f | 486 | struct group_info |
6fb5fa3c DB |
487 | { |
488 | /* The actual base of the address. */ | |
489 | rtx rtx_base; | |
490 | ||
491 | /* The sequential id of the base. This allows us to have a | |
492 | canonical ordering of these that is not based on addresses. */ | |
493 | int id; | |
494 | ||
8f5929e1 JJ |
495 | /* True if there are any positions that are to be processed |
496 | globally. */ | |
497 | bool process_globally; | |
498 | ||
499 | /* True if the base of this group is either the frame_pointer or | |
500 | hard_frame_pointer. */ | |
501 | bool frame_related; | |
502 | ||
d32f725a OH |
503 | /* A mem wrapped around the base pointer for the group in order to do |
504 | read dependency. It must be given BLKmode in order to encompass all | |
505 | the possible offsets from the base. */ | |
6fb5fa3c | 506 | rtx base_mem; |
b8698a0f | 507 | |
6216f94e JJ |
508 | /* Canonized version of base_mem's address. */ |
509 | rtx canon_base_addr; | |
6fb5fa3c DB |
510 | |
511 | /* These two sets of two bitmaps are used to keep track of how many | |
6ed3da00 | 512 | stores are actually referencing that position from this base. We |
6fb5fa3c | 513 | only do this for rtx bases as this will be used to assign |
6ed3da00 | 514 | positions in the bitmaps for the global problem. Bit N is set in |
6fb5fa3c DB |
515 | store1 on the first store for offset N. Bit N is set in store2 |
516 | for the second store to offset N. This is all we need since we | |
517 | only care about offsets that have two or more stores for them. | |
518 | ||
519 | The "_n" suffix is for offsets less than 0 and the "_p" suffix is | |
520 | for 0 and greater offsets. | |
521 | ||
522 | There is one special case here, for stores into the stack frame, | |
523 | we will or store1 into store2 before deciding which stores look | |
524 | at globally. This is because stores to the stack frame that have | |
525 | no other reads before the end of the function can also be | |
526 | deleted. */ | |
527 | bitmap store1_n, store1_p, store2_n, store2_p; | |
528 | ||
d26c7090 ER |
529 | /* These bitmaps keep track of offsets in this group escape this function. |
530 | An offset escapes if it corresponds to a named variable whose | |
531 | addressable flag is set. */ | |
532 | bitmap escaped_n, escaped_p; | |
533 | ||
6ed3da00 | 534 | /* The positions in this bitmap have the same assignments as the in, |
6fb5fa3c | 535 | out, gen and kill bitmaps. This bitmap is all zeros except for |
6ed3da00 | 536 | the positions that are occupied by stores for this group. */ |
6fb5fa3c DB |
537 | bitmap group_kill; |
538 | ||
6fb5fa3c | 539 | /* The offset_map is used to map the offsets from this base into |
6ed3da00 | 540 | positions in the global bitmaps. It is only created after all of |
6fb5fa3c DB |
541 | the all of stores have been scanned and we know which ones we |
542 | care about. */ | |
b8698a0f L |
543 | int *offset_map_n, *offset_map_p; |
544 | int offset_map_size_n, offset_map_size_p; | |
6fb5fa3c DB |
545 | }; |
546 | typedef struct group_info *group_info_t; | |
5f754896 | 547 | typedef const struct group_info *const_group_info_t; |
6fb5fa3c DB |
548 | static alloc_pool rtx_group_info_pool; |
549 | ||
6fb5fa3c DB |
550 | /* Index into the rtx_group_vec. */ |
551 | static int rtx_group_next_id; | |
552 | ||
553 | DEF_VEC_P(group_info_t); | |
554 | DEF_VEC_ALLOC_P(group_info_t,heap); | |
555 | ||
556 | static VEC(group_info_t,heap) *rtx_group_vec; | |
557 | ||
558 | ||
559 | /* This structure holds the set of changes that are being deferred | |
560 | when removing read operation. See replace_read. */ | |
b8698a0f | 561 | struct deferred_change |
6fb5fa3c DB |
562 | { |
563 | ||
564 | /* The mem that is being replaced. */ | |
565 | rtx *loc; | |
566 | ||
567 | /* The reg it is being replaced with. */ | |
568 | rtx reg; | |
569 | ||
570 | struct deferred_change *next; | |
571 | }; | |
572 | ||
573 | typedef struct deferred_change *deferred_change_t; | |
574 | static alloc_pool deferred_change_pool; | |
575 | ||
576 | static deferred_change_t deferred_change_list = NULL; | |
577 | ||
578 | /* This are used to hold the alias sets of spill variables. Since | |
579 | these are never aliased and there may be a lot of them, it makes | |
580 | sense to treat them specially. This bitvector is only allocated in | |
581 | calls from dse_record_singleton_alias_set which currently is only | |
582 | made during reload1. So when dse is called before reload this | |
583 | mechanism does nothing. */ | |
584 | ||
585 | static bitmap clear_alias_sets = NULL; | |
586 | ||
587 | /* The set of clear_alias_sets that have been disqualified because | |
588 | there are loads or stores using a different mode than the alias set | |
b8698a0f | 589 | was registered with. */ |
6fb5fa3c DB |
590 | static bitmap disqualified_clear_alias_sets = NULL; |
591 | ||
592 | /* The group that holds all of the clear_alias_sets. */ | |
593 | static group_info_t clear_alias_group; | |
594 | ||
595 | /* The modes of the clear_alias_sets. */ | |
596 | static htab_t clear_alias_mode_table; | |
597 | ||
598 | /* Hash table element to look up the mode for an alias set. */ | |
599 | struct clear_alias_mode_holder | |
600 | { | |
4862826d | 601 | alias_set_type alias_set; |
6fb5fa3c DB |
602 | enum machine_mode mode; |
603 | }; | |
604 | ||
605 | static alloc_pool clear_alias_mode_pool; | |
606 | ||
e3b5732b | 607 | /* This is true except if cfun->stdarg -- i.e. we cannot do |
9dd9bf80 | 608 | this for vararg functions because they play games with the frame. */ |
6fb5fa3c DB |
609 | static bool stores_off_frame_dead_at_return; |
610 | ||
611 | /* Counter for stats. */ | |
b8698a0f L |
612 | static int globally_deleted; |
613 | static int locally_deleted; | |
614 | static int spill_deleted; | |
615 | ||
6fb5fa3c DB |
616 | static bitmap all_blocks; |
617 | ||
d26c7090 ER |
618 | /* Locations that are killed by calls in the global phase. */ |
619 | static bitmap kill_on_calls; | |
620 | ||
6fb5fa3c DB |
621 | /* The number of bits used in the global bitmaps. */ |
622 | static unsigned int current_position; | |
623 | ||
624 | ||
7d817ebc DE |
625 | static bool gate_dse1 (void); |
626 | static bool gate_dse2 (void); | |
6fb5fa3c DB |
627 | |
628 | \f | |
629 | /*---------------------------------------------------------------------------- | |
630 | Zeroth step. | |
631 | ||
b8698a0f | 632 | Initialization. |
6fb5fa3c DB |
633 | ----------------------------------------------------------------------------*/ |
634 | ||
6fb5fa3c DB |
635 | |
636 | /* Find the entry associated with ALIAS_SET. */ | |
637 | ||
638 | static struct clear_alias_mode_holder * | |
4862826d | 639 | clear_alias_set_lookup (alias_set_type alias_set) |
6fb5fa3c DB |
640 | { |
641 | struct clear_alias_mode_holder tmp_holder; | |
642 | void **slot; | |
b8698a0f | 643 | |
6fb5fa3c DB |
644 | tmp_holder.alias_set = alias_set; |
645 | slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, NO_INSERT); | |
646 | gcc_assert (*slot); | |
b8698a0f | 647 | |
f883e0a7 | 648 | return (struct clear_alias_mode_holder *) *slot; |
6fb5fa3c DB |
649 | } |
650 | ||
651 | ||
652 | /* Hashtable callbacks for maintaining the "bases" field of | |
653 | store_group_info, given that the addresses are function invariants. */ | |
654 | ||
703c8606 LC |
655 | struct invariant_group_base_hasher : typed_noop_remove <group_info> |
656 | { | |
657 | typedef group_info T; | |
658 | static inline hashval_t hash (const T *); | |
659 | static inline bool equal (const T *, const T *); | |
660 | }; | |
661 | ||
662 | inline bool | |
663 | invariant_group_base_hasher::equal (const T *gi1, const T *gi2) | |
6fb5fa3c | 664 | { |
6fb5fa3c DB |
665 | return rtx_equal_p (gi1->rtx_base, gi2->rtx_base); |
666 | } | |
667 | ||
703c8606 LC |
668 | inline hashval_t |
669 | invariant_group_base_hasher::hash (const T *gi) | |
6fb5fa3c | 670 | { |
6fb5fa3c DB |
671 | int do_not_record; |
672 | return hash_rtx (gi->rtx_base, Pmode, &do_not_record, NULL, false); | |
673 | } | |
674 | ||
703c8606 LC |
675 | /* Tables of group_info structures, hashed by base value. */ |
676 | static hash_table <invariant_group_base_hasher> rtx_group_table; | |
677 | ||
6fb5fa3c DB |
678 | |
679 | /* Get the GROUP for BASE. Add a new group if it is not there. */ | |
680 | ||
681 | static group_info_t | |
682 | get_group_info (rtx base) | |
683 | { | |
b8698a0f L |
684 | struct group_info tmp_gi; |
685 | group_info_t gi; | |
703c8606 | 686 | group_info **slot; |
6fb5fa3c DB |
687 | |
688 | if (base) | |
689 | { | |
690 | /* Find the store_base_info structure for BASE, creating a new one | |
691 | if necessary. */ | |
692 | tmp_gi.rtx_base = base; | |
703c8606 | 693 | slot = rtx_group_table.find_slot (&tmp_gi, INSERT); |
6fb5fa3c DB |
694 | gi = (group_info_t) *slot; |
695 | } | |
696 | else | |
697 | { | |
698 | if (!clear_alias_group) | |
699 | { | |
f883e0a7 KG |
700 | clear_alias_group = gi = |
701 | (group_info_t) pool_alloc (rtx_group_info_pool); | |
6fb5fa3c DB |
702 | memset (gi, 0, sizeof (struct group_info)); |
703 | gi->id = rtx_group_next_id++; | |
3f9b14ff SB |
704 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
705 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
706 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
707 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
708 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
709 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
710 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c DB |
711 | gi->process_globally = false; |
712 | gi->offset_map_size_n = 0; | |
713 | gi->offset_map_size_p = 0; | |
714 | gi->offset_map_n = NULL; | |
715 | gi->offset_map_p = NULL; | |
716 | VEC_safe_push (group_info_t, heap, rtx_group_vec, gi); | |
717 | } | |
718 | return clear_alias_group; | |
719 | } | |
720 | ||
721 | if (gi == NULL) | |
722 | { | |
f883e0a7 | 723 | *slot = gi = (group_info_t) pool_alloc (rtx_group_info_pool); |
6fb5fa3c DB |
724 | gi->rtx_base = base; |
725 | gi->id = rtx_group_next_id++; | |
d32f725a | 726 | gi->base_mem = gen_rtx_MEM (BLKmode, base); |
6216f94e | 727 | gi->canon_base_addr = canon_rtx (base); |
3f9b14ff SB |
728 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
729 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
730 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
731 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
732 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
733 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
734 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c | 735 | gi->process_globally = false; |
b8698a0f | 736 | gi->frame_related = |
6fb5fa3c DB |
737 | (base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx); |
738 | gi->offset_map_size_n = 0; | |
739 | gi->offset_map_size_p = 0; | |
740 | gi->offset_map_n = NULL; | |
741 | gi->offset_map_p = NULL; | |
742 | VEC_safe_push (group_info_t, heap, rtx_group_vec, gi); | |
743 | } | |
744 | ||
745 | return gi; | |
746 | } | |
747 | ||
748 | ||
749 | /* Initialization of data structures. */ | |
750 | ||
751 | static void | |
752 | dse_step0 (void) | |
753 | { | |
754 | locally_deleted = 0; | |
755 | globally_deleted = 0; | |
756 | spill_deleted = 0; | |
757 | ||
3f9b14ff SB |
758 | bitmap_obstack_initialize (&dse_bitmap_obstack); |
759 | gcc_obstack_init (&dse_obstack); | |
760 | ||
761 | scratch = BITMAP_ALLOC (®_obstack); | |
762 | kill_on_calls = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c DB |
763 | |
764 | rtx_store_info_pool | |
b8698a0f | 765 | = create_alloc_pool ("rtx_store_info_pool", |
6fb5fa3c DB |
766 | sizeof (struct store_info), 100); |
767 | read_info_pool | |
b8698a0f | 768 | = create_alloc_pool ("read_info_pool", |
6fb5fa3c DB |
769 | sizeof (struct read_info), 100); |
770 | insn_info_pool | |
b8698a0f | 771 | = create_alloc_pool ("insn_info_pool", |
6fb5fa3c DB |
772 | sizeof (struct insn_info), 100); |
773 | bb_info_pool | |
b8698a0f | 774 | = create_alloc_pool ("bb_info_pool", |
6fb5fa3c DB |
775 | sizeof (struct bb_info), 100); |
776 | rtx_group_info_pool | |
b8698a0f | 777 | = create_alloc_pool ("rtx_group_info_pool", |
6fb5fa3c DB |
778 | sizeof (struct group_info), 100); |
779 | deferred_change_pool | |
b8698a0f | 780 | = create_alloc_pool ("deferred_change_pool", |
6fb5fa3c DB |
781 | sizeof (struct deferred_change), 10); |
782 | ||
703c8606 | 783 | rtx_group_table.create (11); |
6fb5fa3c | 784 | |
3f9b14ff | 785 | bb_table = XNEWVEC (bb_info_t, last_basic_block); |
6fb5fa3c DB |
786 | rtx_group_next_id = 0; |
787 | ||
e3b5732b | 788 | stores_off_frame_dead_at_return = !cfun->stdarg; |
6fb5fa3c DB |
789 | |
790 | init_alias_analysis (); | |
b8698a0f | 791 | |
6fb5fa3c DB |
792 | if (clear_alias_sets) |
793 | clear_alias_group = get_group_info (NULL); | |
794 | else | |
795 | clear_alias_group = NULL; | |
796 | } | |
797 | ||
798 | ||
799 | \f | |
800 | /*---------------------------------------------------------------------------- | |
801 | First step. | |
802 | ||
803 | Scan all of the insns. Any random ordering of the blocks is fine. | |
0d52bcc1 | 804 | Each block is scanned in forward order to accommodate cselib which |
6fb5fa3c DB |
805 | is used to remove stores with non-constant bases. |
806 | ----------------------------------------------------------------------------*/ | |
807 | ||
808 | /* Delete all of the store_info recs from INSN_INFO. */ | |
809 | ||
b8698a0f | 810 | static void |
6fb5fa3c DB |
811 | free_store_info (insn_info_t insn_info) |
812 | { | |
813 | store_info_t store_info = insn_info->store_rec; | |
814 | while (store_info) | |
815 | { | |
816 | store_info_t next = store_info->next; | |
8dd5516b | 817 | if (store_info->is_large) |
dc491a25 | 818 | BITMAP_FREE (store_info->positions_needed.large.bmap); |
6fb5fa3c DB |
819 | if (store_info->cse_base) |
820 | pool_free (cse_store_info_pool, store_info); | |
821 | else | |
822 | pool_free (rtx_store_info_pool, store_info); | |
823 | store_info = next; | |
824 | } | |
825 | ||
826 | insn_info->cannot_delete = true; | |
827 | insn_info->contains_cselib_groups = false; | |
828 | insn_info->store_rec = NULL; | |
829 | } | |
830 | ||
9e582b1d JR |
831 | typedef struct |
832 | { | |
833 | rtx first, current; | |
834 | regset fixed_regs_live; | |
835 | bool failure; | |
836 | } note_add_store_info; | |
837 | ||
838 | /* Callback for emit_inc_dec_insn_before via note_stores. | |
839 | Check if a register is clobbered which is live afterwards. */ | |
840 | ||
841 | static void | |
842 | note_add_store (rtx loc, const_rtx expr ATTRIBUTE_UNUSED, void *data) | |
843 | { | |
844 | rtx insn; | |
845 | note_add_store_info *info = (note_add_store_info *) data; | |
846 | int r, n; | |
847 | ||
848 | if (!REG_P (loc)) | |
849 | return; | |
850 | ||
851 | /* If this register is referenced by the current or an earlier insn, | |
852 | that's OK. E.g. this applies to the register that is being incremented | |
853 | with this addition. */ | |
854 | for (insn = info->first; | |
855 | insn != NEXT_INSN (info->current); | |
856 | insn = NEXT_INSN (insn)) | |
857 | if (reg_referenced_p (loc, PATTERN (insn))) | |
858 | return; | |
859 | ||
860 | /* If we come here, we have a clobber of a register that's only OK | |
861 | if that register is not live. If we don't have liveness information | |
862 | available, fail now. */ | |
863 | if (!info->fixed_regs_live) | |
864 | { | |
865 | info->failure = true; | |
866 | return; | |
867 | } | |
868 | /* Now check if this is a live fixed register. */ | |
869 | r = REGNO (loc); | |
870 | n = hard_regno_nregs[r][GET_MODE (loc)]; | |
871 | while (--n >= 0) | |
872 | if (REGNO_REG_SET_P (info->fixed_regs_live, r+n)) | |
873 | info->failure = true; | |
874 | } | |
875 | ||
4deef538 AO |
876 | /* Callback for for_each_inc_dec that emits an INSN that sets DEST to |
877 | SRC + SRCOFF before insn ARG. */ | |
6fb5fa3c DB |
878 | |
879 | static int | |
4deef538 AO |
880 | emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED, |
881 | rtx op ATTRIBUTE_UNUSED, | |
882 | rtx dest, rtx src, rtx srcoff, void *arg) | |
6fb5fa3c | 883 | { |
9e582b1d JR |
884 | insn_info_t insn_info = (insn_info_t) arg; |
885 | rtx insn = insn_info->insn, new_insn, cur; | |
886 | note_add_store_info info; | |
b8698a0f | 887 | |
4deef538 AO |
888 | /* We can reuse all operands without copying, because we are about |
889 | to delete the insn that contained it. */ | |
9e582b1d | 890 | if (srcoff) |
ed079c4b JJ |
891 | { |
892 | start_sequence (); | |
893 | emit_insn (gen_add3_insn (dest, src, srcoff)); | |
894 | new_insn = get_insns (); | |
895 | end_sequence (); | |
896 | } | |
9e582b1d JR |
897 | else |
898 | new_insn = gen_move_insn (dest, src); | |
899 | info.first = new_insn; | |
900 | info.fixed_regs_live = insn_info->fixed_regs_live; | |
901 | info.failure = false; | |
902 | for (cur = new_insn; cur; cur = NEXT_INSN (cur)) | |
903 | { | |
904 | info.current = cur; | |
905 | note_stores (PATTERN (cur), note_add_store, &info); | |
906 | } | |
6fb5fa3c | 907 | |
9e582b1d JR |
908 | /* If a failure was flagged above, return 1 so that for_each_inc_dec will |
909 | return it immediately, communicating the failure to its caller. */ | |
910 | if (info.failure) | |
911 | return 1; | |
912 | ||
913 | emit_insn_before (new_insn, insn); | |
6fb5fa3c | 914 | |
4deef538 | 915 | return -1; |
6fb5fa3c DB |
916 | } |
917 | ||
9e582b1d JR |
918 | /* Before we delete INSN_INFO->INSN, make sure that the auto inc/dec, if it |
919 | is there, is split into a separate insn. | |
920 | Return true on success (or if there was nothing to do), false on failure. */ | |
6fb5fa3c | 921 | |
9e582b1d JR |
922 | static bool |
923 | check_for_inc_dec_1 (insn_info_t insn_info) | |
6fb5fa3c | 924 | { |
9e582b1d | 925 | rtx insn = insn_info->insn; |
6fb5fa3c DB |
926 | rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
927 | if (note) | |
9e582b1d JR |
928 | return for_each_inc_dec (&insn, emit_inc_dec_insn_before, insn_info) == 0; |
929 | return true; | |
6fb5fa3c DB |
930 | } |
931 | ||
932 | ||
9e582b1d JR |
933 | /* Entry point for postreload. If you work on reload_cse, or you need this |
934 | anywhere else, consider if you can provide register liveness information | |
935 | and add a parameter to this function so that it can be passed down in | |
936 | insn_info.fixed_regs_live. */ | |
937 | bool | |
938 | check_for_inc_dec (rtx insn) | |
939 | { | |
940 | struct insn_info insn_info; | |
941 | rtx note; | |
942 | ||
943 | insn_info.insn = insn; | |
944 | insn_info.fixed_regs_live = NULL; | |
945 | note = find_reg_note (insn, REG_INC, NULL_RTX); | |
946 | if (note) | |
947 | return for_each_inc_dec (&insn, emit_inc_dec_insn_before, &insn_info) == 0; | |
948 | return true; | |
949 | } | |
950 | ||
b8698a0f | 951 | /* Delete the insn and free all of the fields inside INSN_INFO. */ |
6fb5fa3c DB |
952 | |
953 | static void | |
954 | delete_dead_store_insn (insn_info_t insn_info) | |
955 | { | |
956 | read_info_t read_info; | |
957 | ||
958 | if (!dbg_cnt (dse)) | |
959 | return; | |
960 | ||
9e582b1d JR |
961 | if (!check_for_inc_dec_1 (insn_info)) |
962 | return; | |
6fb5fa3c DB |
963 | if (dump_file) |
964 | { | |
b8698a0f | 965 | fprintf (dump_file, "Locally deleting insn %d ", |
6fb5fa3c DB |
966 | INSN_UID (insn_info->insn)); |
967 | if (insn_info->store_rec->alias_set) | |
b8698a0f | 968 | fprintf (dump_file, "alias set %d\n", |
4862826d | 969 | (int) insn_info->store_rec->alias_set); |
6fb5fa3c DB |
970 | else |
971 | fprintf (dump_file, "\n"); | |
972 | } | |
973 | ||
974 | free_store_info (insn_info); | |
975 | read_info = insn_info->read_rec; | |
b8698a0f | 976 | |
6fb5fa3c DB |
977 | while (read_info) |
978 | { | |
979 | read_info_t next = read_info->next; | |
980 | pool_free (read_info_pool, read_info); | |
981 | read_info = next; | |
982 | } | |
983 | insn_info->read_rec = NULL; | |
984 | ||
985 | delete_insn (insn_info->insn); | |
986 | locally_deleted++; | |
987 | insn_info->insn = NULL; | |
988 | ||
989 | insn_info->wild_read = false; | |
990 | } | |
991 | ||
d26c7090 ER |
992 | /* Check if EXPR can possibly escape the current function scope. */ |
993 | static bool | |
994 | can_escape (tree expr) | |
995 | { | |
996 | tree base; | |
997 | if (!expr) | |
998 | return true; | |
999 | base = get_base_address (expr); | |
1000 | if (DECL_P (base) | |
1001 | && !may_be_aliased (base)) | |
1002 | return false; | |
1003 | return true; | |
1004 | } | |
6fb5fa3c DB |
1005 | |
1006 | /* Set the store* bitmaps offset_map_size* fields in GROUP based on | |
1007 | OFFSET and WIDTH. */ | |
1008 | ||
1009 | static void | |
d26c7090 ER |
1010 | set_usage_bits (group_info_t group, HOST_WIDE_INT offset, HOST_WIDE_INT width, |
1011 | tree expr) | |
6fb5fa3c DB |
1012 | { |
1013 | HOST_WIDE_INT i; | |
d26c7090 | 1014 | bool expr_escapes = can_escape (expr); |
8dd5516b | 1015 | if (offset > -MAX_OFFSET && offset + width < MAX_OFFSET) |
6fb5fa3c DB |
1016 | for (i=offset; i<offset+width; i++) |
1017 | { | |
1018 | bitmap store1; | |
1019 | bitmap store2; | |
d26c7090 | 1020 | bitmap escaped; |
6fb5fa3c DB |
1021 | int ai; |
1022 | if (i < 0) | |
1023 | { | |
1024 | store1 = group->store1_n; | |
1025 | store2 = group->store2_n; | |
d26c7090 | 1026 | escaped = group->escaped_n; |
6fb5fa3c DB |
1027 | ai = -i; |
1028 | } | |
1029 | else | |
1030 | { | |
1031 | store1 = group->store1_p; | |
1032 | store2 = group->store2_p; | |
d26c7090 | 1033 | escaped = group->escaped_p; |
6fb5fa3c DB |
1034 | ai = i; |
1035 | } | |
b8698a0f | 1036 | |
fcaa4ca4 | 1037 | if (!bitmap_set_bit (store1, ai)) |
6fb5fa3c | 1038 | bitmap_set_bit (store2, ai); |
b8698a0f | 1039 | else |
6fb5fa3c | 1040 | { |
6fb5fa3c DB |
1041 | if (i < 0) |
1042 | { | |
1043 | if (group->offset_map_size_n < ai) | |
1044 | group->offset_map_size_n = ai; | |
1045 | } | |
1046 | else | |
1047 | { | |
1048 | if (group->offset_map_size_p < ai) | |
1049 | group->offset_map_size_p = ai; | |
1050 | } | |
1051 | } | |
d26c7090 ER |
1052 | if (expr_escapes) |
1053 | bitmap_set_bit (escaped, ai); | |
6fb5fa3c DB |
1054 | } |
1055 | } | |
1056 | ||
d26c7090 ER |
1057 | static void |
1058 | reset_active_stores (void) | |
1059 | { | |
1060 | active_local_stores = NULL; | |
1061 | active_local_stores_len = 0; | |
1062 | } | |
6fb5fa3c | 1063 | |
d26c7090 | 1064 | /* Free all READ_REC of the LAST_INSN of BB_INFO. */ |
6fb5fa3c DB |
1065 | |
1066 | static void | |
d26c7090 | 1067 | free_read_records (bb_info_t bb_info) |
6fb5fa3c DB |
1068 | { |
1069 | insn_info_t insn_info = bb_info->last_insn; | |
1070 | read_info_t *ptr = &insn_info->read_rec; | |
6fb5fa3c DB |
1071 | while (*ptr) |
1072 | { | |
1073 | read_info_t next = (*ptr)->next; | |
4862826d | 1074 | if ((*ptr)->alias_set == 0) |
6fb5fa3c DB |
1075 | { |
1076 | pool_free (read_info_pool, *ptr); | |
1077 | *ptr = next; | |
d26c7090 | 1078 | } |
b8698a0f | 1079 | else |
d26c7090 | 1080 | ptr = &(*ptr)->next; |
6fb5fa3c | 1081 | } |
d26c7090 ER |
1082 | } |
1083 | ||
1084 | /* Set the BB_INFO so that the last insn is marked as a wild read. */ | |
1085 | ||
1086 | static void | |
1087 | add_wild_read (bb_info_t bb_info) | |
1088 | { | |
1089 | insn_info_t insn_info = bb_info->last_insn; | |
6fb5fa3c | 1090 | insn_info->wild_read = true; |
d26c7090 ER |
1091 | free_read_records (bb_info); |
1092 | reset_active_stores (); | |
6fb5fa3c DB |
1093 | } |
1094 | ||
d26c7090 ER |
1095 | /* Set the BB_INFO so that the last insn is marked as a wild read of |
1096 | non-frame locations. */ | |
1097 | ||
1098 | static void | |
1099 | add_non_frame_wild_read (bb_info_t bb_info) | |
1100 | { | |
1101 | insn_info_t insn_info = bb_info->last_insn; | |
1102 | insn_info->non_frame_wild_read = true; | |
1103 | free_read_records (bb_info); | |
1104 | reset_active_stores (); | |
1105 | } | |
6fb5fa3c | 1106 | |
50f0f366 EB |
1107 | /* Return true if X is a constant or one of the registers that behave |
1108 | as a constant over the life of a function. This is equivalent to | |
1109 | !rtx_varies_p for memory addresses. */ | |
6fb5fa3c DB |
1110 | |
1111 | static bool | |
1112 | const_or_frame_p (rtx x) | |
1113 | { | |
d8116890 KZ |
1114 | if (CONSTANT_P (x)) |
1115 | return true; | |
1116 | ||
1117 | if (GET_CODE (x) == REG) | |
6fb5fa3c | 1118 | { |
6fb5fa3c DB |
1119 | /* Note that we have to test for the actual rtx used for the frame |
1120 | and arg pointers and not just the register number in case we have | |
1121 | eliminated the frame and/or arg pointer and are using it | |
1122 | for pseudos. */ | |
1123 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx | |
1124 | /* The arg pointer varies if it is not a fixed register. */ | |
1125 | || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
1126 | || x == pic_offset_table_rtx) | |
1127 | return true; | |
1128 | return false; | |
6fb5fa3c | 1129 | } |
d8116890 KZ |
1130 | |
1131 | return false; | |
6fb5fa3c DB |
1132 | } |
1133 | ||
b8698a0f L |
1134 | /* Take all reasonable action to put the address of MEM into the form |
1135 | that we can do analysis on. | |
6fb5fa3c DB |
1136 | |
1137 | The gold standard is to get the address into the form: address + | |
1138 | OFFSET where address is something that rtx_varies_p considers a | |
1139 | constant. When we can get the address in this form, we can do | |
1140 | global analysis on it. Note that for constant bases, address is | |
1141 | not actually returned, only the group_id. The address can be | |
1142 | obtained from that. | |
1143 | ||
1144 | If that fails, we try cselib to get a value we can at least use | |
b8698a0f L |
1145 | locally. If that fails we return false. |
1146 | ||
6fb5fa3c DB |
1147 | The GROUP_ID is set to -1 for cselib bases and the index of the |
1148 | group for non_varying bases. | |
1149 | ||
1150 | FOR_READ is true if this is a mem read and false if not. */ | |
1151 | ||
1152 | static bool | |
1153 | canon_address (rtx mem, | |
4862826d | 1154 | alias_set_type *alias_set_out, |
6fb5fa3c | 1155 | int *group_id, |
b8698a0f | 1156 | HOST_WIDE_INT *offset, |
6fb5fa3c DB |
1157 | cselib_val **base) |
1158 | { | |
372d6395 | 1159 | enum machine_mode address_mode = get_address_mode (mem); |
6fb5fa3c DB |
1160 | rtx mem_address = XEXP (mem, 0); |
1161 | rtx expanded_address, address; | |
403c7520 JJ |
1162 | int expanded; |
1163 | ||
6fb5fa3c DB |
1164 | /* Make sure that cselib is has initialized all of the operands of |
1165 | the address before asking it to do the subst. */ | |
1166 | ||
1167 | if (clear_alias_sets) | |
1168 | { | |
1169 | /* If this is a spill, do not do any further processing. */ | |
4862826d | 1170 | alias_set_type alias_set = MEM_ALIAS_SET (mem); |
6fb5fa3c | 1171 | if (dump_file) |
4862826d | 1172 | fprintf (dump_file, "found alias set %d\n", (int) alias_set); |
6fb5fa3c DB |
1173 | if (bitmap_bit_p (clear_alias_sets, alias_set)) |
1174 | { | |
b8698a0f | 1175 | struct clear_alias_mode_holder *entry |
6fb5fa3c DB |
1176 | = clear_alias_set_lookup (alias_set); |
1177 | ||
1178 | /* If the modes do not match, we cannot process this set. */ | |
1179 | if (entry->mode != GET_MODE (mem)) | |
1180 | { | |
1181 | if (dump_file) | |
b8698a0f L |
1182 | fprintf (dump_file, |
1183 | "disqualifying alias set %d, (%s) != (%s)\n", | |
1184 | (int) alias_set, GET_MODE_NAME (entry->mode), | |
6fb5fa3c | 1185 | GET_MODE_NAME (GET_MODE (mem))); |
b8698a0f | 1186 | |
6fb5fa3c DB |
1187 | bitmap_set_bit (disqualified_clear_alias_sets, alias_set); |
1188 | return false; | |
1189 | } | |
1190 | ||
1191 | *alias_set_out = alias_set; | |
1192 | *group_id = clear_alias_group->id; | |
1193 | return true; | |
1194 | } | |
1195 | } | |
1196 | ||
1197 | *alias_set_out = 0; | |
1198 | ||
4deef538 | 1199 | cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem)); |
6fb5fa3c DB |
1200 | |
1201 | if (dump_file) | |
1202 | { | |
1203 | fprintf (dump_file, " mem: "); | |
1204 | print_inline_rtx (dump_file, mem_address, 0); | |
1205 | fprintf (dump_file, "\n"); | |
1206 | } | |
1207 | ||
403c7520 JJ |
1208 | /* First see if just canon_rtx (mem_address) is const or frame, |
1209 | if not, try cselib_expand_value_rtx and call canon_rtx on that. */ | |
1210 | address = NULL_RTX; | |
1211 | for (expanded = 0; expanded < 2; expanded++) | |
1212 | { | |
1213 | if (expanded) | |
1214 | { | |
1215 | /* Use cselib to replace all of the reg references with the full | |
b8698a0f | 1216 | expression. This will take care of the case where we have |
6fb5fa3c | 1217 | |
403c7520 JJ |
1218 | r_x = base + offset; |
1219 | val = *r_x; | |
b8698a0f L |
1220 | |
1221 | by making it into | |
6fb5fa3c | 1222 | |
403c7520 | 1223 | val = *(base + offset); */ |
6fb5fa3c | 1224 | |
403c7520 JJ |
1225 | expanded_address = cselib_expand_value_rtx (mem_address, |
1226 | scratch, 5); | |
6fb5fa3c | 1227 | |
403c7520 JJ |
1228 | /* If this fails, just go with the address from first |
1229 | iteration. */ | |
1230 | if (!expanded_address) | |
1231 | break; | |
1232 | } | |
1233 | else | |
1234 | expanded_address = mem_address; | |
6fb5fa3c | 1235 | |
403c7520 JJ |
1236 | /* Split the address into canonical BASE + OFFSET terms. */ |
1237 | address = canon_rtx (expanded_address); | |
6fb5fa3c | 1238 | |
403c7520 | 1239 | *offset = 0; |
6fb5fa3c | 1240 | |
403c7520 JJ |
1241 | if (dump_file) |
1242 | { | |
1243 | if (expanded) | |
1244 | { | |
1245 | fprintf (dump_file, "\n after cselib_expand address: "); | |
1246 | print_inline_rtx (dump_file, expanded_address, 0); | |
1247 | fprintf (dump_file, "\n"); | |
1248 | } | |
6fb5fa3c | 1249 | |
403c7520 JJ |
1250 | fprintf (dump_file, "\n after canon_rtx address: "); |
1251 | print_inline_rtx (dump_file, address, 0); | |
1252 | fprintf (dump_file, "\n"); | |
1253 | } | |
6fb5fa3c | 1254 | |
403c7520 JJ |
1255 | if (GET_CODE (address) == CONST) |
1256 | address = XEXP (address, 0); | |
6fb5fa3c | 1257 | |
403c7520 JJ |
1258 | if (GET_CODE (address) == PLUS |
1259 | && CONST_INT_P (XEXP (address, 1))) | |
1260 | { | |
1261 | *offset = INTVAL (XEXP (address, 1)); | |
1262 | address = XEXP (address, 0); | |
1263 | } | |
6fb5fa3c | 1264 | |
09e881c9 BE |
1265 | if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem)) |
1266 | && const_or_frame_p (address)) | |
6fb5fa3c | 1267 | { |
403c7520 JJ |
1268 | group_info_t group = get_group_info (address); |
1269 | ||
6fb5fa3c | 1270 | if (dump_file) |
403c7520 JJ |
1271 | fprintf (dump_file, " gid=%d offset=%d \n", |
1272 | group->id, (int)*offset); | |
1273 | *base = NULL; | |
1274 | *group_id = group->id; | |
1275 | return true; | |
6fb5fa3c | 1276 | } |
403c7520 JJ |
1277 | } |
1278 | ||
4deef538 | 1279 | *base = cselib_lookup (address, address_mode, true, GET_MODE (mem)); |
403c7520 JJ |
1280 | *group_id = -1; |
1281 | ||
1282 | if (*base == NULL) | |
1283 | { | |
6fb5fa3c | 1284 | if (dump_file) |
403c7520 JJ |
1285 | fprintf (dump_file, " no cselib val - should be a wild read.\n"); |
1286 | return false; | |
6fb5fa3c | 1287 | } |
403c7520 | 1288 | if (dump_file) |
5440c0e7 AO |
1289 | fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n", |
1290 | (*base)->uid, (*base)->hash, (int)*offset); | |
6fb5fa3c DB |
1291 | return true; |
1292 | } | |
1293 | ||
1294 | ||
1295 | /* Clear the rhs field from the active_local_stores array. */ | |
1296 | ||
1297 | static void | |
1298 | clear_rhs_from_active_local_stores (void) | |
1299 | { | |
1300 | insn_info_t ptr = active_local_stores; | |
1301 | ||
1302 | while (ptr) | |
1303 | { | |
1304 | store_info_t store_info = ptr->store_rec; | |
1305 | /* Skip the clobbers. */ | |
1306 | while (!store_info->is_set) | |
1307 | store_info = store_info->next; | |
1308 | ||
1309 | store_info->rhs = NULL; | |
8dd5516b | 1310 | store_info->const_rhs = NULL; |
6fb5fa3c DB |
1311 | |
1312 | ptr = ptr->next_local_store; | |
1313 | } | |
1314 | } | |
1315 | ||
1316 | ||
8dd5516b JJ |
1317 | /* Mark byte POS bytes from the beginning of store S_INFO as unneeded. */ |
1318 | ||
1319 | static inline void | |
1320 | set_position_unneeded (store_info_t s_info, int pos) | |
1321 | { | |
1322 | if (__builtin_expect (s_info->is_large, false)) | |
1323 | { | |
fcaa4ca4 NF |
1324 | if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos)) |
1325 | s_info->positions_needed.large.count++; | |
8dd5516b JJ |
1326 | } |
1327 | else | |
1328 | s_info->positions_needed.small_bitmask | |
1329 | &= ~(((unsigned HOST_WIDE_INT) 1) << pos); | |
1330 | } | |
1331 | ||
1332 | /* Mark the whole store S_INFO as unneeded. */ | |
1333 | ||
1334 | static inline void | |
1335 | set_all_positions_unneeded (store_info_t s_info) | |
1336 | { | |
1337 | if (__builtin_expect (s_info->is_large, false)) | |
1338 | { | |
1339 | int pos, end = s_info->end - s_info->begin; | |
1340 | for (pos = 0; pos < end; pos++) | |
dc491a25 | 1341 | bitmap_set_bit (s_info->positions_needed.large.bmap, pos); |
8dd5516b JJ |
1342 | s_info->positions_needed.large.count = end; |
1343 | } | |
1344 | else | |
1345 | s_info->positions_needed.small_bitmask = (unsigned HOST_WIDE_INT) 0; | |
1346 | } | |
1347 | ||
1348 | /* Return TRUE if any bytes from S_INFO store are needed. */ | |
1349 | ||
1350 | static inline bool | |
1351 | any_positions_needed_p (store_info_t s_info) | |
1352 | { | |
1353 | if (__builtin_expect (s_info->is_large, false)) | |
1354 | return (s_info->positions_needed.large.count | |
1355 | < s_info->end - s_info->begin); | |
1356 | else | |
1357 | return (s_info->positions_needed.small_bitmask | |
1358 | != (unsigned HOST_WIDE_INT) 0); | |
1359 | } | |
1360 | ||
1361 | /* Return TRUE if all bytes START through START+WIDTH-1 from S_INFO | |
1362 | store are needed. */ | |
1363 | ||
1364 | static inline bool | |
1365 | all_positions_needed_p (store_info_t s_info, int start, int width) | |
1366 | { | |
1367 | if (__builtin_expect (s_info->is_large, false)) | |
1368 | { | |
1369 | int end = start + width; | |
1370 | while (start < end) | |
dc491a25 | 1371 | if (bitmap_bit_p (s_info->positions_needed.large.bmap, start++)) |
8dd5516b JJ |
1372 | return false; |
1373 | return true; | |
1374 | } | |
1375 | else | |
1376 | { | |
1377 | unsigned HOST_WIDE_INT mask = lowpart_bitmask (width) << start; | |
1378 | return (s_info->positions_needed.small_bitmask & mask) == mask; | |
1379 | } | |
1380 | } | |
1381 | ||
1382 | ||
1383 | static rtx get_stored_val (store_info_t, enum machine_mode, HOST_WIDE_INT, | |
1384 | HOST_WIDE_INT, basic_block, bool); | |
1385 | ||
1386 | ||
6fb5fa3c DB |
1387 | /* BODY is an instruction pattern that belongs to INSN. Return 1 if |
1388 | there is a candidate store, after adding it to the appropriate | |
1389 | local store group if so. */ | |
1390 | ||
1391 | static int | |
1392 | record_store (rtx body, bb_info_t bb_info) | |
1393 | { | |
6216f94e | 1394 | rtx mem, rhs, const_rhs, mem_addr; |
6fb5fa3c DB |
1395 | HOST_WIDE_INT offset = 0; |
1396 | HOST_WIDE_INT width = 0; | |
4862826d | 1397 | alias_set_type spill_alias_set; |
6fb5fa3c DB |
1398 | insn_info_t insn_info = bb_info->last_insn; |
1399 | store_info_t store_info = NULL; | |
1400 | int group_id; | |
1401 | cselib_val *base = NULL; | |
8dd5516b | 1402 | insn_info_t ptr, last, redundant_reason; |
6fb5fa3c DB |
1403 | bool store_is_unused; |
1404 | ||
1405 | if (GET_CODE (body) != SET && GET_CODE (body) != CLOBBER) | |
1406 | return 0; | |
1407 | ||
8dd5516b JJ |
1408 | mem = SET_DEST (body); |
1409 | ||
6fb5fa3c DB |
1410 | /* If this is not used, then this cannot be used to keep the insn |
1411 | from being deleted. On the other hand, it does provide something | |
1412 | that can be used to prove that another store is dead. */ | |
1413 | store_is_unused | |
8dd5516b | 1414 | = (find_reg_note (insn_info->insn, REG_UNUSED, mem) != NULL); |
6fb5fa3c DB |
1415 | |
1416 | /* Check whether that value is a suitable memory location. */ | |
6fb5fa3c DB |
1417 | if (!MEM_P (mem)) |
1418 | { | |
1419 | /* If the set or clobber is unused, then it does not effect our | |
1420 | ability to get rid of the entire insn. */ | |
1421 | if (!store_is_unused) | |
1422 | insn_info->cannot_delete = true; | |
1423 | return 0; | |
1424 | } | |
1425 | ||
1426 | /* At this point we know mem is a mem. */ | |
1427 | if (GET_MODE (mem) == BLKmode) | |
1428 | { | |
1429 | if (GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
1430 | { | |
b8698a0f | 1431 | if (dump_file) |
6fb5fa3c DB |
1432 | fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n"); |
1433 | add_wild_read (bb_info); | |
1434 | insn_info->cannot_delete = true; | |
8dd5516b | 1435 | return 0; |
6fb5fa3c | 1436 | } |
8dd5516b JJ |
1437 | /* Handle (set (mem:BLK (addr) [... S36 ...]) (const_int 0)) |
1438 | as memset (addr, 0, 36); */ | |
f5541398 RS |
1439 | else if (!MEM_SIZE_KNOWN_P (mem) |
1440 | || MEM_SIZE (mem) <= 0 | |
1441 | || MEM_SIZE (mem) > MAX_OFFSET | |
8dd5516b | 1442 | || GET_CODE (body) != SET |
8dd5516b | 1443 | || !CONST_INT_P (SET_SRC (body))) |
6fb5fa3c | 1444 | { |
8dd5516b JJ |
1445 | if (!store_is_unused) |
1446 | { | |
1447 | /* If the set or clobber is unused, then it does not effect our | |
1448 | ability to get rid of the entire insn. */ | |
1449 | insn_info->cannot_delete = true; | |
1450 | clear_rhs_from_active_local_stores (); | |
1451 | } | |
1452 | return 0; | |
6fb5fa3c | 1453 | } |
6fb5fa3c DB |
1454 | } |
1455 | ||
1456 | /* We can still process a volatile mem, we just cannot delete it. */ | |
1457 | if (MEM_VOLATILE_P (mem)) | |
8dd5516b | 1458 | insn_info->cannot_delete = true; |
6fb5fa3c DB |
1459 | |
1460 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
1461 | { | |
1462 | clear_rhs_from_active_local_stores (); | |
1463 | return 0; | |
1464 | } | |
1465 | ||
8dd5516b | 1466 | if (GET_MODE (mem) == BLKmode) |
f5541398 | 1467 | width = MEM_SIZE (mem); |
8dd5516b JJ |
1468 | else |
1469 | { | |
1470 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
1471 | gcc_assert ((unsigned) width <= HOST_BITS_PER_WIDE_INT); | |
1472 | } | |
6fb5fa3c DB |
1473 | |
1474 | if (spill_alias_set) | |
1475 | { | |
1476 | bitmap store1 = clear_alias_group->store1_p; | |
1477 | bitmap store2 = clear_alias_group->store2_p; | |
8dd5516b JJ |
1478 | |
1479 | gcc_assert (GET_MODE (mem) != BLKmode); | |
b8698a0f | 1480 | |
fcaa4ca4 | 1481 | if (!bitmap_set_bit (store1, spill_alias_set)) |
6fb5fa3c | 1482 | bitmap_set_bit (store2, spill_alias_set); |
b8698a0f | 1483 | |
6fb5fa3c DB |
1484 | if (clear_alias_group->offset_map_size_p < spill_alias_set) |
1485 | clear_alias_group->offset_map_size_p = spill_alias_set; | |
b8698a0f | 1486 | |
f883e0a7 | 1487 | store_info = (store_info_t) pool_alloc (rtx_store_info_pool); |
6fb5fa3c DB |
1488 | |
1489 | if (dump_file) | |
1490 | fprintf (dump_file, " processing spill store %d(%s)\n", | |
4862826d | 1491 | (int) spill_alias_set, GET_MODE_NAME (GET_MODE (mem))); |
6fb5fa3c DB |
1492 | } |
1493 | else if (group_id >= 0) | |
1494 | { | |
1495 | /* In the restrictive case where the base is a constant or the | |
1496 | frame pointer we can do global analysis. */ | |
b8698a0f L |
1497 | |
1498 | group_info_t group | |
6fb5fa3c | 1499 | = VEC_index (group_info_t, rtx_group_vec, group_id); |
d26c7090 | 1500 | tree expr = MEM_EXPR (mem); |
b8698a0f | 1501 | |
f883e0a7 | 1502 | store_info = (store_info_t) pool_alloc (rtx_store_info_pool); |
d26c7090 | 1503 | set_usage_bits (group, offset, width, expr); |
6fb5fa3c DB |
1504 | |
1505 | if (dump_file) | |
1506 | fprintf (dump_file, " processing const base store gid=%d[%d..%d)\n", | |
1507 | group_id, (int)offset, (int)(offset+width)); | |
1508 | } | |
1509 | else | |
1510 | { | |
9e412ca3 | 1511 | if (may_be_sp_based_p (XEXP (mem, 0))) |
50f0f366 | 1512 | insn_info->stack_pointer_based = true; |
6fb5fa3c | 1513 | insn_info->contains_cselib_groups = true; |
50f0f366 | 1514 | |
f883e0a7 | 1515 | store_info = (store_info_t) pool_alloc (cse_store_info_pool); |
6fb5fa3c DB |
1516 | group_id = -1; |
1517 | ||
1518 | if (dump_file) | |
1519 | fprintf (dump_file, " processing cselib store [%d..%d)\n", | |
1520 | (int)offset, (int)(offset+width)); | |
1521 | } | |
1522 | ||
8dd5516b JJ |
1523 | const_rhs = rhs = NULL_RTX; |
1524 | if (GET_CODE (body) == SET | |
1525 | /* No place to keep the value after ra. */ | |
1526 | && !reload_completed | |
1527 | && (REG_P (SET_SRC (body)) | |
1528 | || GET_CODE (SET_SRC (body)) == SUBREG | |
1529 | || CONSTANT_P (SET_SRC (body))) | |
1530 | && !MEM_VOLATILE_P (mem) | |
1531 | /* Sometimes the store and reload is used for truncation and | |
1532 | rounding. */ | |
1533 | && !(FLOAT_MODE_P (GET_MODE (mem)) && (flag_float_store))) | |
1534 | { | |
1535 | rhs = SET_SRC (body); | |
1536 | if (CONSTANT_P (rhs)) | |
1537 | const_rhs = rhs; | |
1538 | else if (body == PATTERN (insn_info->insn)) | |
1539 | { | |
1540 | rtx tem = find_reg_note (insn_info->insn, REG_EQUAL, NULL_RTX); | |
1541 | if (tem && CONSTANT_P (XEXP (tem, 0))) | |
1542 | const_rhs = XEXP (tem, 0); | |
1543 | } | |
1544 | if (const_rhs == NULL_RTX && REG_P (rhs)) | |
1545 | { | |
1546 | rtx tem = cselib_expand_value_rtx (rhs, scratch, 5); | |
1547 | ||
1548 | if (tem && CONSTANT_P (tem)) | |
1549 | const_rhs = tem; | |
1550 | } | |
1551 | } | |
1552 | ||
6fb5fa3c DB |
1553 | /* Check to see if this stores causes some other stores to be |
1554 | dead. */ | |
1555 | ptr = active_local_stores; | |
1556 | last = NULL; | |
8dd5516b | 1557 | redundant_reason = NULL; |
6216f94e JJ |
1558 | mem = canon_rtx (mem); |
1559 | /* For alias_set != 0 canon_true_dependence should be never called. */ | |
1560 | if (spill_alias_set) | |
1561 | mem_addr = NULL_RTX; | |
1562 | else | |
1563 | { | |
1564 | if (group_id < 0) | |
1565 | mem_addr = base->val_rtx; | |
1566 | else | |
1567 | { | |
1568 | group_info_t group | |
1569 | = VEC_index (group_info_t, rtx_group_vec, group_id); | |
1570 | mem_addr = group->canon_base_addr; | |
1571 | } | |
1572 | if (offset) | |
372d6395 | 1573 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
6216f94e | 1574 | } |
6fb5fa3c DB |
1575 | |
1576 | while (ptr) | |
1577 | { | |
1578 | insn_info_t next = ptr->next_local_store; | |
1579 | store_info_t s_info = ptr->store_rec; | |
60564289 | 1580 | bool del = true; |
6fb5fa3c DB |
1581 | |
1582 | /* Skip the clobbers. We delete the active insn if this insn | |
6ed3da00 | 1583 | shadows the set. To have been put on the active list, it |
6fb5fa3c DB |
1584 | has exactly on set. */ |
1585 | while (!s_info->is_set) | |
1586 | s_info = s_info->next; | |
1587 | ||
1588 | if (s_info->alias_set != spill_alias_set) | |
60564289 | 1589 | del = false; |
6fb5fa3c DB |
1590 | else if (s_info->alias_set) |
1591 | { | |
b8698a0f | 1592 | struct clear_alias_mode_holder *entry |
6fb5fa3c DB |
1593 | = clear_alias_set_lookup (s_info->alias_set); |
1594 | /* Generally, spills cannot be processed if and of the | |
1595 | references to the slot have a different mode. But if | |
1596 | we are in the same block and mode is exactly the same | |
1597 | between this store and one before in the same block, | |
1598 | we can still delete it. */ | |
1599 | if ((GET_MODE (mem) == GET_MODE (s_info->mem)) | |
1600 | && (GET_MODE (mem) == entry->mode)) | |
1601 | { | |
60564289 | 1602 | del = true; |
8dd5516b | 1603 | set_all_positions_unneeded (s_info); |
6fb5fa3c DB |
1604 | } |
1605 | if (dump_file) | |
1606 | fprintf (dump_file, " trying spill store in insn=%d alias_set=%d\n", | |
4862826d | 1607 | INSN_UID (ptr->insn), (int) s_info->alias_set); |
6fb5fa3c | 1608 | } |
b8698a0f | 1609 | else if ((s_info->group_id == group_id) |
6fb5fa3c DB |
1610 | && (s_info->cse_base == base)) |
1611 | { | |
1612 | HOST_WIDE_INT i; | |
1613 | if (dump_file) | |
1614 | fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n", | |
b8698a0f | 1615 | INSN_UID (ptr->insn), s_info->group_id, |
6fb5fa3c | 1616 | (int)s_info->begin, (int)s_info->end); |
8dd5516b JJ |
1617 | |
1618 | /* Even if PTR won't be eliminated as unneeded, if both | |
1619 | PTR and this insn store the same constant value, we might | |
1620 | eliminate this insn instead. */ | |
1621 | if (s_info->const_rhs | |
1622 | && const_rhs | |
1623 | && offset >= s_info->begin | |
1624 | && offset + width <= s_info->end | |
1625 | && all_positions_needed_p (s_info, offset - s_info->begin, | |
1626 | width)) | |
1627 | { | |
1628 | if (GET_MODE (mem) == BLKmode) | |
1629 | { | |
1630 | if (GET_MODE (s_info->mem) == BLKmode | |
1631 | && s_info->const_rhs == const_rhs) | |
1632 | redundant_reason = ptr; | |
1633 | } | |
1634 | else if (s_info->const_rhs == const0_rtx | |
1635 | && const_rhs == const0_rtx) | |
1636 | redundant_reason = ptr; | |
1637 | else | |
1638 | { | |
1639 | rtx val; | |
1640 | start_sequence (); | |
1641 | val = get_stored_val (s_info, GET_MODE (mem), | |
1642 | offset, offset + width, | |
1643 | BLOCK_FOR_INSN (insn_info->insn), | |
1644 | true); | |
1645 | if (get_insns () != NULL) | |
1646 | val = NULL_RTX; | |
1647 | end_sequence (); | |
1648 | if (val && rtx_equal_p (val, const_rhs)) | |
1649 | redundant_reason = ptr; | |
1650 | } | |
1651 | } | |
1652 | ||
1653 | for (i = MAX (offset, s_info->begin); | |
1654 | i < offset + width && i < s_info->end; | |
1655 | i++) | |
1656 | set_position_unneeded (s_info, i - s_info->begin); | |
6fb5fa3c DB |
1657 | } |
1658 | else if (s_info->rhs) | |
1659 | /* Need to see if it is possible for this store to overwrite | |
1660 | the value of store_info. If it is, set the rhs to NULL to | |
1661 | keep it from being used to remove a load. */ | |
1662 | { | |
b8698a0f | 1663 | if (canon_true_dependence (s_info->mem, |
6fb5fa3c DB |
1664 | GET_MODE (s_info->mem), |
1665 | s_info->mem_addr, | |
53d9622b | 1666 | mem, mem_addr)) |
8dd5516b JJ |
1667 | { |
1668 | s_info->rhs = NULL; | |
1669 | s_info->const_rhs = NULL; | |
1670 | } | |
6fb5fa3c | 1671 | } |
6216f94e | 1672 | |
6fb5fa3c DB |
1673 | /* An insn can be deleted if every position of every one of |
1674 | its s_infos is zero. */ | |
1b6fa860 | 1675 | if (any_positions_needed_p (s_info)) |
60564289 | 1676 | del = false; |
8dd5516b | 1677 | |
60564289 | 1678 | if (del) |
6fb5fa3c DB |
1679 | { |
1680 | insn_info_t insn_to_delete = ptr; | |
b8698a0f | 1681 | |
dabd47e7 | 1682 | active_local_stores_len--; |
6fb5fa3c DB |
1683 | if (last) |
1684 | last->next_local_store = ptr->next_local_store; | |
1685 | else | |
1686 | active_local_stores = ptr->next_local_store; | |
b8698a0f | 1687 | |
1b6fa860 JJ |
1688 | if (!insn_to_delete->cannot_delete) |
1689 | delete_dead_store_insn (insn_to_delete); | |
6fb5fa3c DB |
1690 | } |
1691 | else | |
1692 | last = ptr; | |
b8698a0f | 1693 | |
6fb5fa3c DB |
1694 | ptr = next; |
1695 | } | |
b8698a0f | 1696 | |
6fb5fa3c DB |
1697 | /* Finish filling in the store_info. */ |
1698 | store_info->next = insn_info->store_rec; | |
1699 | insn_info->store_rec = store_info; | |
6216f94e | 1700 | store_info->mem = mem; |
6fb5fa3c | 1701 | store_info->alias_set = spill_alias_set; |
6216f94e | 1702 | store_info->mem_addr = mem_addr; |
6fb5fa3c | 1703 | store_info->cse_base = base; |
8dd5516b JJ |
1704 | if (width > HOST_BITS_PER_WIDE_INT) |
1705 | { | |
1706 | store_info->is_large = true; | |
1707 | store_info->positions_needed.large.count = 0; | |
3f9b14ff | 1708 | store_info->positions_needed.large.bmap = BITMAP_ALLOC (&dse_bitmap_obstack); |
8dd5516b JJ |
1709 | } |
1710 | else | |
1711 | { | |
1712 | store_info->is_large = false; | |
1713 | store_info->positions_needed.small_bitmask = lowpart_bitmask (width); | |
1714 | } | |
6fb5fa3c DB |
1715 | store_info->group_id = group_id; |
1716 | store_info->begin = offset; | |
1717 | store_info->end = offset + width; | |
1718 | store_info->is_set = GET_CODE (body) == SET; | |
8dd5516b JJ |
1719 | store_info->rhs = rhs; |
1720 | store_info->const_rhs = const_rhs; | |
1721 | store_info->redundant_reason = redundant_reason; | |
6fb5fa3c | 1722 | |
6fb5fa3c DB |
1723 | /* If this is a clobber, we return 0. We will only be able to |
1724 | delete this insn if there is only one store USED store, but we | |
1725 | can use the clobber to delete other stores earlier. */ | |
1726 | return store_info->is_set ? 1 : 0; | |
1727 | } | |
1728 | ||
1729 | ||
1730 | static void | |
1731 | dump_insn_info (const char * start, insn_info_t insn_info) | |
1732 | { | |
b8698a0f | 1733 | fprintf (dump_file, "%s insn=%d %s\n", start, |
6fb5fa3c DB |
1734 | INSN_UID (insn_info->insn), |
1735 | insn_info->store_rec ? "has store" : "naked"); | |
1736 | } | |
1737 | ||
1738 | ||
8660aaae EC |
1739 | /* If the modes are different and the value's source and target do not |
1740 | line up, we need to extract the value from lower part of the rhs of | |
1741 | the store, shift it, and then put it into a form that can be shoved | |
1742 | into the read_insn. This function generates a right SHIFT of a | |
1743 | value that is at least ACCESS_SIZE bytes wide of READ_MODE. The | |
1744 | shift sequence is returned or NULL if we failed to find a | |
1745 | shift. */ | |
1746 | ||
1747 | static rtx | |
18b526e8 | 1748 | find_shift_sequence (int access_size, |
8660aaae | 1749 | store_info_t store_info, |
8dd5516b JJ |
1750 | enum machine_mode read_mode, |
1751 | int shift, bool speed, bool require_cst) | |
8660aaae EC |
1752 | { |
1753 | enum machine_mode store_mode = GET_MODE (store_info->mem); | |
18b526e8 RS |
1754 | enum machine_mode new_mode; |
1755 | rtx read_reg = NULL; | |
8660aaae EC |
1756 | |
1757 | /* Some machines like the x86 have shift insns for each size of | |
1758 | operand. Other machines like the ppc or the ia-64 may only have | |
1759 | shift insns that shift values within 32 or 64 bit registers. | |
1760 | This loop tries to find the smallest shift insn that will right | |
1761 | justify the value we want to read but is available in one insn on | |
1762 | the machine. */ | |
1763 | ||
18b526e8 RS |
1764 | for (new_mode = smallest_mode_for_size (access_size * BITS_PER_UNIT, |
1765 | MODE_INT); | |
1766 | GET_MODE_BITSIZE (new_mode) <= BITS_PER_WORD; | |
1767 | new_mode = GET_MODE_WIDER_MODE (new_mode)) | |
8660aaae | 1768 | { |
18b526e8 | 1769 | rtx target, new_reg, shift_seq, insn, new_lhs; |
d898d29b | 1770 | int cost; |
348eea5f | 1771 | |
72a2609f JJ |
1772 | /* If a constant was stored into memory, try to simplify it here, |
1773 | otherwise the cost of the shift might preclude this optimization | |
1774 | e.g. at -Os, even when no actual shift will be needed. */ | |
8dd5516b | 1775 | if (store_info->const_rhs) |
72a2609f JJ |
1776 | { |
1777 | unsigned int byte = subreg_lowpart_offset (new_mode, store_mode); | |
8dd5516b JJ |
1778 | rtx ret = simplify_subreg (new_mode, store_info->const_rhs, |
1779 | store_mode, byte); | |
72a2609f JJ |
1780 | if (ret && CONSTANT_P (ret)) |
1781 | { | |
1782 | ret = simplify_const_binary_operation (LSHIFTRT, new_mode, | |
1783 | ret, GEN_INT (shift)); | |
1784 | if (ret && CONSTANT_P (ret)) | |
1785 | { | |
1786 | byte = subreg_lowpart_offset (read_mode, new_mode); | |
1787 | ret = simplify_subreg (read_mode, ret, new_mode, byte); | |
1788 | if (ret && CONSTANT_P (ret) | |
5e8f01f4 | 1789 | && set_src_cost (ret, speed) <= COSTS_N_INSNS (1)) |
72a2609f JJ |
1790 | return ret; |
1791 | } | |
1792 | } | |
1793 | } | |
1794 | ||
8dd5516b JJ |
1795 | if (require_cst) |
1796 | return NULL_RTX; | |
1797 | ||
18b526e8 RS |
1798 | /* Try a wider mode if truncating the store mode to NEW_MODE |
1799 | requires a real instruction. */ | |
1800 | if (GET_MODE_BITSIZE (new_mode) < GET_MODE_BITSIZE (store_mode) | |
d0edd768 | 1801 | && !TRULY_NOOP_TRUNCATION_MODES_P (new_mode, store_mode)) |
348eea5f RS |
1802 | continue; |
1803 | ||
18b526e8 RS |
1804 | /* Also try a wider mode if the necessary punning is either not |
1805 | desirable or not possible. */ | |
1806 | if (!CONSTANT_P (store_info->rhs) | |
1807 | && !MODES_TIEABLE_P (new_mode, store_mode)) | |
1808 | continue; | |
18b526e8 | 1809 | |
348eea5f | 1810 | new_reg = gen_reg_rtx (new_mode); |
8660aaae EC |
1811 | |
1812 | start_sequence (); | |
1813 | ||
1814 | /* In theory we could also check for an ashr. Ian Taylor knows | |
1815 | of one dsp where the cost of these two was not the same. But | |
1816 | this really is a rare case anyway. */ | |
1817 | target = expand_binop (new_mode, lshr_optab, new_reg, | |
1818 | GEN_INT (shift), new_reg, 1, OPTAB_DIRECT); | |
1819 | ||
c6f3019a RS |
1820 | shift_seq = get_insns (); |
1821 | end_sequence (); | |
8660aaae | 1822 | |
c6f3019a RS |
1823 | if (target != new_reg || shift_seq == NULL) |
1824 | continue; | |
1825 | ||
1826 | cost = 0; | |
1827 | for (insn = shift_seq; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
1828 | if (INSN_P (insn)) | |
f40751dd | 1829 | cost += insn_rtx_cost (PATTERN (insn), speed); |
c6f3019a RS |
1830 | |
1831 | /* The computation up to here is essentially independent | |
1832 | of the arguments and could be precomputed. It may | |
1833 | not be worth doing so. We could precompute if | |
1834 | worthwhile or at least cache the results. The result | |
06acf7d0 RS |
1835 | technically depends on both SHIFT and ACCESS_SIZE, |
1836 | but in practice the answer will depend only on ACCESS_SIZE. */ | |
c6f3019a RS |
1837 | |
1838 | if (cost > COSTS_N_INSNS (1)) | |
1839 | continue; | |
1840 | ||
d898d29b JJ |
1841 | new_lhs = extract_low_bits (new_mode, store_mode, |
1842 | copy_rtx (store_info->rhs)); | |
1843 | if (new_lhs == NULL_RTX) | |
1844 | continue; | |
1845 | ||
c6f3019a RS |
1846 | /* We found an acceptable shift. Generate a move to |
1847 | take the value from the store and put it into the | |
1848 | shift pseudo, then shift it, then generate another | |
1849 | move to put in into the target of the read. */ | |
18b526e8 | 1850 | emit_move_insn (new_reg, new_lhs); |
c6f3019a | 1851 | emit_insn (shift_seq); |
18b526e8 | 1852 | read_reg = extract_low_bits (read_mode, new_mode, new_reg); |
c6f3019a | 1853 | break; |
8660aaae EC |
1854 | } |
1855 | ||
18b526e8 | 1856 | return read_reg; |
8660aaae EC |
1857 | } |
1858 | ||
1859 | ||
02b47899 KZ |
1860 | /* Call back for note_stores to find the hard regs set or clobbered by |
1861 | insn. Data is a bitmap of the hardregs set so far. */ | |
1862 | ||
1863 | static void | |
1864 | look_for_hardregs (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) | |
1865 | { | |
1866 | bitmap regs_set = (bitmap) data; | |
1867 | ||
1868 | if (REG_P (x) | |
f773c2bd | 1869 | && HARD_REGISTER_P (x)) |
02b47899 | 1870 | { |
f773c2bd AS |
1871 | unsigned int regno = REGNO (x); |
1872 | bitmap_set_range (regs_set, regno, | |
1873 | hard_regno_nregs[regno][GET_MODE (x)]); | |
02b47899 KZ |
1874 | } |
1875 | } | |
1876 | ||
8dd5516b JJ |
1877 | /* Helper function for replace_read and record_store. |
1878 | Attempt to return a value stored in STORE_INFO, from READ_BEGIN | |
1879 | to one before READ_END bytes read in READ_MODE. Return NULL | |
1880 | if not successful. If REQUIRE_CST is true, return always constant. */ | |
1881 | ||
1882 | static rtx | |
1883 | get_stored_val (store_info_t store_info, enum machine_mode read_mode, | |
1884 | HOST_WIDE_INT read_begin, HOST_WIDE_INT read_end, | |
1885 | basic_block bb, bool require_cst) | |
1886 | { | |
1887 | enum machine_mode store_mode = GET_MODE (store_info->mem); | |
1888 | int shift; | |
1889 | int access_size; /* In bytes. */ | |
1890 | rtx read_reg; | |
1891 | ||
1892 | /* To get here the read is within the boundaries of the write so | |
1893 | shift will never be negative. Start out with the shift being in | |
1894 | bytes. */ | |
1895 | if (store_mode == BLKmode) | |
1896 | shift = 0; | |
1897 | else if (BYTES_BIG_ENDIAN) | |
1898 | shift = store_info->end - read_end; | |
1899 | else | |
1900 | shift = read_begin - store_info->begin; | |
1901 | ||
1902 | access_size = shift + GET_MODE_SIZE (read_mode); | |
1903 | ||
1904 | /* From now on it is bits. */ | |
1905 | shift *= BITS_PER_UNIT; | |
1906 | ||
1907 | if (shift) | |
1908 | read_reg = find_shift_sequence (access_size, store_info, read_mode, shift, | |
1909 | optimize_bb_for_speed_p (bb), | |
1910 | require_cst); | |
1911 | else if (store_mode == BLKmode) | |
1912 | { | |
1913 | /* The store is a memset (addr, const_val, const_size). */ | |
1914 | gcc_assert (CONST_INT_P (store_info->rhs)); | |
1915 | store_mode = int_mode_for_mode (read_mode); | |
1916 | if (store_mode == BLKmode) | |
1917 | read_reg = NULL_RTX; | |
1918 | else if (store_info->rhs == const0_rtx) | |
1919 | read_reg = extract_low_bits (read_mode, store_mode, const0_rtx); | |
1920 | else if (GET_MODE_BITSIZE (store_mode) > HOST_BITS_PER_WIDE_INT | |
1921 | || BITS_PER_UNIT >= HOST_BITS_PER_WIDE_INT) | |
1922 | read_reg = NULL_RTX; | |
1923 | else | |
1924 | { | |
1925 | unsigned HOST_WIDE_INT c | |
1926 | = INTVAL (store_info->rhs) | |
1927 | & (((HOST_WIDE_INT) 1 << BITS_PER_UNIT) - 1); | |
1928 | int shift = BITS_PER_UNIT; | |
1929 | while (shift < HOST_BITS_PER_WIDE_INT) | |
1930 | { | |
1931 | c |= (c << shift); | |
1932 | shift <<= 1; | |
1933 | } | |
6d26322f | 1934 | read_reg = gen_int_mode (c, store_mode); |
8dd5516b JJ |
1935 | read_reg = extract_low_bits (read_mode, store_mode, read_reg); |
1936 | } | |
1937 | } | |
1938 | else if (store_info->const_rhs | |
1939 | && (require_cst | |
1940 | || GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))) | |
1941 | read_reg = extract_low_bits (read_mode, store_mode, | |
1942 | copy_rtx (store_info->const_rhs)); | |
1943 | else | |
1944 | read_reg = extract_low_bits (read_mode, store_mode, | |
1945 | copy_rtx (store_info->rhs)); | |
1946 | if (require_cst && read_reg && !CONSTANT_P (read_reg)) | |
1947 | read_reg = NULL_RTX; | |
1948 | return read_reg; | |
1949 | } | |
02b47899 | 1950 | |
6fb5fa3c DB |
1951 | /* Take a sequence of: |
1952 | A <- r1 | |
1953 | ... | |
1954 | ... <- A | |
1955 | ||
b8698a0f | 1956 | and change it into |
6fb5fa3c DB |
1957 | r2 <- r1 |
1958 | A <- r1 | |
1959 | ... | |
1960 | ... <- r2 | |
1961 | ||
8660aaae EC |
1962 | or |
1963 | ||
1964 | r3 <- extract (r1) | |
1965 | r3 <- r3 >> shift | |
1966 | r2 <- extract (r3) | |
1967 | ... <- r2 | |
1968 | ||
1969 | or | |
1970 | ||
1971 | r2 <- extract (r1) | |
1972 | ... <- r2 | |
1973 | ||
1974 | Depending on the alignment and the mode of the store and | |
1975 | subsequent load. | |
1976 | ||
1977 | ||
1978 | The STORE_INFO and STORE_INSN are for the store and READ_INFO | |
6fb5fa3c DB |
1979 | and READ_INSN are for the read. Return true if the replacement |
1980 | went ok. */ | |
1981 | ||
1982 | static bool | |
b8698a0f | 1983 | replace_read (store_info_t store_info, insn_info_t store_insn, |
8dd5516b JJ |
1984 | read_info_t read_info, insn_info_t read_insn, rtx *loc, |
1985 | bitmap regs_live) | |
6fb5fa3c | 1986 | { |
8660aaae EC |
1987 | enum machine_mode store_mode = GET_MODE (store_info->mem); |
1988 | enum machine_mode read_mode = GET_MODE (read_info->mem); | |
02b47899 | 1989 | rtx insns, this_insn, read_reg; |
8dd5516b | 1990 | basic_block bb; |
8660aaae | 1991 | |
6fb5fa3c DB |
1992 | if (!dbg_cnt (dse)) |
1993 | return false; | |
1994 | ||
18b526e8 RS |
1995 | /* Create a sequence of instructions to set up the read register. |
1996 | This sequence goes immediately before the store and its result | |
1997 | is read by the load. | |
1998 | ||
1999 | We need to keep this in perspective. We are replacing a read | |
8660aaae EC |
2000 | with a sequence of insns, but the read will almost certainly be |
2001 | in cache, so it is not going to be an expensive one. Thus, we | |
2002 | are not willing to do a multi insn shift or worse a subroutine | |
2003 | call to get rid of the read. */ | |
18b526e8 RS |
2004 | if (dump_file) |
2005 | fprintf (dump_file, "trying to replace %smode load in insn %d" | |
2006 | " from %smode store in insn %d\n", | |
2007 | GET_MODE_NAME (read_mode), INSN_UID (read_insn->insn), | |
2008 | GET_MODE_NAME (store_mode), INSN_UID (store_insn->insn)); | |
2009 | start_sequence (); | |
8dd5516b JJ |
2010 | bb = BLOCK_FOR_INSN (read_insn->insn); |
2011 | read_reg = get_stored_val (store_info, | |
2012 | read_mode, read_info->begin, read_info->end, | |
2013 | bb, false); | |
18b526e8 | 2014 | if (read_reg == NULL_RTX) |
8660aaae | 2015 | { |
18b526e8 RS |
2016 | end_sequence (); |
2017 | if (dump_file) | |
2018 | fprintf (dump_file, " -- could not extract bits of stored value\n"); | |
2019 | return false; | |
8660aaae | 2020 | } |
18b526e8 RS |
2021 | /* Force the value into a new register so that it won't be clobbered |
2022 | between the store and the load. */ | |
2023 | read_reg = copy_to_mode_reg (read_mode, read_reg); | |
2024 | insns = get_insns (); | |
2025 | end_sequence (); | |
8660aaae | 2026 | |
02b47899 KZ |
2027 | if (insns != NULL_RTX) |
2028 | { | |
2029 | /* Now we have to scan the set of new instructions to see if the | |
2030 | sequence contains and sets of hardregs that happened to be | |
2031 | live at this point. For instance, this can happen if one of | |
2032 | the insns sets the CC and the CC happened to be live at that | |
2033 | point. This does occasionally happen, see PR 37922. */ | |
3f9b14ff | 2034 | bitmap regs_set = BITMAP_ALLOC (®_obstack); |
02b47899 KZ |
2035 | |
2036 | for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn)) | |
2037 | note_stores (PATTERN (this_insn), look_for_hardregs, regs_set); | |
b8698a0f | 2038 | |
02b47899 KZ |
2039 | bitmap_and_into (regs_set, regs_live); |
2040 | if (!bitmap_empty_p (regs_set)) | |
2041 | { | |
2042 | if (dump_file) | |
2043 | { | |
b8698a0f | 2044 | fprintf (dump_file, |
02b47899 KZ |
2045 | "abandoning replacement because sequence clobbers live hardregs:"); |
2046 | df_print_regset (dump_file, regs_set); | |
2047 | } | |
b8698a0f | 2048 | |
02b47899 KZ |
2049 | BITMAP_FREE (regs_set); |
2050 | return false; | |
2051 | } | |
2052 | BITMAP_FREE (regs_set); | |
2053 | } | |
2054 | ||
8660aaae | 2055 | if (validate_change (read_insn->insn, loc, read_reg, 0)) |
6fb5fa3c | 2056 | { |
f883e0a7 KG |
2057 | deferred_change_t deferred_change = |
2058 | (deferred_change_t) pool_alloc (deferred_change_pool); | |
b8698a0f | 2059 | |
8660aaae EC |
2060 | /* Insert this right before the store insn where it will be safe |
2061 | from later insns that might change it before the read. */ | |
2062 | emit_insn_before (insns, store_insn->insn); | |
b8698a0f | 2063 | |
8660aaae EC |
2064 | /* And now for the kludge part: cselib croaks if you just |
2065 | return at this point. There are two reasons for this: | |
b8698a0f | 2066 | |
8660aaae EC |
2067 | 1) Cselib has an idea of how many pseudos there are and |
2068 | that does not include the new ones we just added. | |
b8698a0f | 2069 | |
8660aaae EC |
2070 | 2) Cselib does not know about the move insn we added |
2071 | above the store_info, and there is no way to tell it | |
2072 | about it, because it has "moved on". | |
b8698a0f | 2073 | |
8660aaae EC |
2074 | Problem (1) is fixable with a certain amount of engineering. |
2075 | Problem (2) is requires starting the bb from scratch. This | |
2076 | could be expensive. | |
b8698a0f | 2077 | |
8660aaae EC |
2078 | So we are just going to have to lie. The move/extraction |
2079 | insns are not really an issue, cselib did not see them. But | |
2080 | the use of the new pseudo read_insn is a real problem because | |
2081 | cselib has not scanned this insn. The way that we solve this | |
2082 | problem is that we are just going to put the mem back for now | |
2083 | and when we are finished with the block, we undo this. We | |
2084 | keep a table of mems to get rid of. At the end of the basic | |
2085 | block we can put them back. */ | |
b8698a0f | 2086 | |
8660aaae EC |
2087 | *loc = read_info->mem; |
2088 | deferred_change->next = deferred_change_list; | |
2089 | deferred_change_list = deferred_change; | |
2090 | deferred_change->loc = loc; | |
2091 | deferred_change->reg = read_reg; | |
b8698a0f | 2092 | |
8660aaae EC |
2093 | /* Get rid of the read_info, from the point of view of the |
2094 | rest of dse, play like this read never happened. */ | |
2095 | read_insn->read_rec = read_info->next; | |
2096 | pool_free (read_info_pool, read_info); | |
18b526e8 RS |
2097 | if (dump_file) |
2098 | { | |
2099 | fprintf (dump_file, " -- replaced the loaded MEM with "); | |
2100 | print_simple_rtl (dump_file, read_reg); | |
2101 | fprintf (dump_file, "\n"); | |
2102 | } | |
8660aaae | 2103 | return true; |
6fb5fa3c | 2104 | } |
b8698a0f | 2105 | else |
6fb5fa3c | 2106 | { |
6fb5fa3c | 2107 | if (dump_file) |
18b526e8 RS |
2108 | { |
2109 | fprintf (dump_file, " -- replacing the loaded MEM with "); | |
2110 | print_simple_rtl (dump_file, read_reg); | |
2111 | fprintf (dump_file, " led to an invalid instruction\n"); | |
2112 | } | |
6fb5fa3c DB |
2113 | return false; |
2114 | } | |
2115 | } | |
2116 | ||
6fb5fa3c DB |
2117 | /* A for_each_rtx callback in which DATA is the bb_info. Check to see |
2118 | if LOC is a mem and if it is look at the address and kill any | |
2119 | appropriate stores that may be active. */ | |
2120 | ||
2121 | static int | |
2122 | check_mem_read_rtx (rtx *loc, void *data) | |
2123 | { | |
6216f94e | 2124 | rtx mem = *loc, mem_addr; |
6fb5fa3c DB |
2125 | bb_info_t bb_info; |
2126 | insn_info_t insn_info; | |
2127 | HOST_WIDE_INT offset = 0; | |
2128 | HOST_WIDE_INT width = 0; | |
4862826d | 2129 | alias_set_type spill_alias_set = 0; |
b8698a0f | 2130 | cselib_val *base = NULL; |
6fb5fa3c DB |
2131 | int group_id; |
2132 | read_info_t read_info; | |
2133 | ||
2134 | if (!mem || !MEM_P (mem)) | |
2135 | return 0; | |
2136 | ||
2137 | bb_info = (bb_info_t) data; | |
2138 | insn_info = bb_info->last_insn; | |
2139 | ||
2140 | if ((MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2141 | || (MEM_VOLATILE_P (mem))) | |
2142 | { | |
2143 | if (dump_file) | |
2144 | fprintf (dump_file, " adding wild read, volatile or barrier.\n"); | |
2145 | add_wild_read (bb_info); | |
2146 | insn_info->cannot_delete = true; | |
2147 | return 0; | |
2148 | } | |
2149 | ||
2150 | /* If it is reading readonly mem, then there can be no conflict with | |
2151 | another write. */ | |
2152 | if (MEM_READONLY_P (mem)) | |
2153 | return 0; | |
2154 | ||
2155 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
2156 | { | |
2157 | if (dump_file) | |
2158 | fprintf (dump_file, " adding wild read, canon_address failure.\n"); | |
2159 | add_wild_read (bb_info); | |
2160 | return 0; | |
2161 | } | |
2162 | ||
2163 | if (GET_MODE (mem) == BLKmode) | |
2164 | width = -1; | |
2165 | else | |
2166 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
2167 | ||
f883e0a7 | 2168 | read_info = (read_info_t) pool_alloc (read_info_pool); |
6fb5fa3c DB |
2169 | read_info->group_id = group_id; |
2170 | read_info->mem = mem; | |
2171 | read_info->alias_set = spill_alias_set; | |
2172 | read_info->begin = offset; | |
2173 | read_info->end = offset + width; | |
2174 | read_info->next = insn_info->read_rec; | |
2175 | insn_info->read_rec = read_info; | |
6216f94e JJ |
2176 | /* For alias_set != 0 canon_true_dependence should be never called. */ |
2177 | if (spill_alias_set) | |
2178 | mem_addr = NULL_RTX; | |
2179 | else | |
2180 | { | |
2181 | if (group_id < 0) | |
2182 | mem_addr = base->val_rtx; | |
2183 | else | |
2184 | { | |
2185 | group_info_t group | |
2186 | = VEC_index (group_info_t, rtx_group_vec, group_id); | |
2187 | mem_addr = group->canon_base_addr; | |
2188 | } | |
2189 | if (offset) | |
372d6395 | 2190 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
6216f94e | 2191 | } |
6fb5fa3c | 2192 | |
0d52bcc1 | 2193 | /* We ignore the clobbers in store_info. The is mildly aggressive, |
6fb5fa3c DB |
2194 | but there really should not be a clobber followed by a read. */ |
2195 | ||
2196 | if (spill_alias_set) | |
2197 | { | |
2198 | insn_info_t i_ptr = active_local_stores; | |
2199 | insn_info_t last = NULL; | |
2200 | ||
2201 | if (dump_file) | |
2202 | fprintf (dump_file, " processing spill load %d\n", | |
4862826d | 2203 | (int) spill_alias_set); |
6fb5fa3c DB |
2204 | |
2205 | while (i_ptr) | |
2206 | { | |
2207 | store_info_t store_info = i_ptr->store_rec; | |
2208 | ||
2209 | /* Skip the clobbers. */ | |
2210 | while (!store_info->is_set) | |
2211 | store_info = store_info->next; | |
b8698a0f | 2212 | |
6fb5fa3c DB |
2213 | if (store_info->alias_set == spill_alias_set) |
2214 | { | |
2215 | if (dump_file) | |
2216 | dump_insn_info ("removing from active", i_ptr); | |
2217 | ||
dabd47e7 | 2218 | active_local_stores_len--; |
6fb5fa3c DB |
2219 | if (last) |
2220 | last->next_local_store = i_ptr->next_local_store; | |
2221 | else | |
2222 | active_local_stores = i_ptr->next_local_store; | |
2223 | } | |
2224 | else | |
2225 | last = i_ptr; | |
2226 | i_ptr = i_ptr->next_local_store; | |
2227 | } | |
2228 | } | |
2229 | else if (group_id >= 0) | |
2230 | { | |
2231 | /* This is the restricted case where the base is a constant or | |
2232 | the frame pointer and offset is a constant. */ | |
2233 | insn_info_t i_ptr = active_local_stores; | |
2234 | insn_info_t last = NULL; | |
b8698a0f | 2235 | |
6fb5fa3c DB |
2236 | if (dump_file) |
2237 | { | |
2238 | if (width == -1) | |
2239 | fprintf (dump_file, " processing const load gid=%d[BLK]\n", | |
2240 | group_id); | |
2241 | else | |
2242 | fprintf (dump_file, " processing const load gid=%d[%d..%d)\n", | |
2243 | group_id, (int)offset, (int)(offset+width)); | |
2244 | } | |
2245 | ||
2246 | while (i_ptr) | |
2247 | { | |
2248 | bool remove = false; | |
2249 | store_info_t store_info = i_ptr->store_rec; | |
b8698a0f | 2250 | |
6fb5fa3c DB |
2251 | /* Skip the clobbers. */ |
2252 | while (!store_info->is_set) | |
2253 | store_info = store_info->next; | |
b8698a0f | 2254 | |
6fb5fa3c DB |
2255 | /* There are three cases here. */ |
2256 | if (store_info->group_id < 0) | |
2257 | /* We have a cselib store followed by a read from a | |
2258 | const base. */ | |
b8698a0f L |
2259 | remove |
2260 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2261 | GET_MODE (store_info->mem), |
2262 | store_info->mem_addr, | |
53d9622b | 2263 | mem, mem_addr); |
b8698a0f | 2264 | |
6fb5fa3c DB |
2265 | else if (group_id == store_info->group_id) |
2266 | { | |
2267 | /* This is a block mode load. We may get lucky and | |
2268 | canon_true_dependence may save the day. */ | |
2269 | if (width == -1) | |
b8698a0f L |
2270 | remove |
2271 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2272 | GET_MODE (store_info->mem), |
2273 | store_info->mem_addr, | |
53d9622b | 2274 | mem, mem_addr); |
b8698a0f | 2275 | |
6fb5fa3c DB |
2276 | /* If this read is just reading back something that we just |
2277 | stored, rewrite the read. */ | |
b8698a0f | 2278 | else |
6fb5fa3c DB |
2279 | { |
2280 | if (store_info->rhs | |
8dd5516b JJ |
2281 | && offset >= store_info->begin |
2282 | && offset + width <= store_info->end | |
2283 | && all_positions_needed_p (store_info, | |
2284 | offset - store_info->begin, | |
2285 | width) | |
2286 | && replace_read (store_info, i_ptr, read_info, | |
2287 | insn_info, loc, bb_info->regs_live)) | |
2288 | return 0; | |
2289 | ||
6fb5fa3c DB |
2290 | /* The bases are the same, just see if the offsets |
2291 | overlap. */ | |
b8698a0f | 2292 | if ((offset < store_info->end) |
6fb5fa3c DB |
2293 | && (offset + width > store_info->begin)) |
2294 | remove = true; | |
2295 | } | |
2296 | } | |
b8698a0f L |
2297 | |
2298 | /* else | |
6fb5fa3c DB |
2299 | The else case that is missing here is that the |
2300 | bases are constant but different. There is nothing | |
2301 | to do here because there is no overlap. */ | |
b8698a0f | 2302 | |
6fb5fa3c DB |
2303 | if (remove) |
2304 | { | |
2305 | if (dump_file) | |
2306 | dump_insn_info ("removing from active", i_ptr); | |
2307 | ||
dabd47e7 | 2308 | active_local_stores_len--; |
6fb5fa3c DB |
2309 | if (last) |
2310 | last->next_local_store = i_ptr->next_local_store; | |
2311 | else | |
2312 | active_local_stores = i_ptr->next_local_store; | |
2313 | } | |
2314 | else | |
2315 | last = i_ptr; | |
2316 | i_ptr = i_ptr->next_local_store; | |
2317 | } | |
2318 | } | |
b8698a0f | 2319 | else |
6fb5fa3c DB |
2320 | { |
2321 | insn_info_t i_ptr = active_local_stores; | |
2322 | insn_info_t last = NULL; | |
2323 | if (dump_file) | |
2324 | { | |
2325 | fprintf (dump_file, " processing cselib load mem:"); | |
2326 | print_inline_rtx (dump_file, mem, 0); | |
2327 | fprintf (dump_file, "\n"); | |
2328 | } | |
2329 | ||
2330 | while (i_ptr) | |
2331 | { | |
2332 | bool remove = false; | |
2333 | store_info_t store_info = i_ptr->store_rec; | |
b8698a0f | 2334 | |
6fb5fa3c DB |
2335 | if (dump_file) |
2336 | fprintf (dump_file, " processing cselib load against insn %d\n", | |
2337 | INSN_UID (i_ptr->insn)); | |
2338 | ||
2339 | /* Skip the clobbers. */ | |
2340 | while (!store_info->is_set) | |
2341 | store_info = store_info->next; | |
2342 | ||
2343 | /* If this read is just reading back something that we just | |
2344 | stored, rewrite the read. */ | |
2345 | if (store_info->rhs | |
2346 | && store_info->group_id == -1 | |
2347 | && store_info->cse_base == base | |
efc3527a | 2348 | && width != -1 |
8dd5516b JJ |
2349 | && offset >= store_info->begin |
2350 | && offset + width <= store_info->end | |
2351 | && all_positions_needed_p (store_info, | |
2352 | offset - store_info->begin, width) | |
2353 | && replace_read (store_info, i_ptr, read_info, insn_info, loc, | |
2354 | bb_info->regs_live)) | |
2355 | return 0; | |
6fb5fa3c DB |
2356 | |
2357 | if (!store_info->alias_set) | |
b8698a0f | 2358 | remove = canon_true_dependence (store_info->mem, |
6fb5fa3c DB |
2359 | GET_MODE (store_info->mem), |
2360 | store_info->mem_addr, | |
53d9622b | 2361 | mem, mem_addr); |
b8698a0f | 2362 | |
6fb5fa3c DB |
2363 | if (remove) |
2364 | { | |
2365 | if (dump_file) | |
2366 | dump_insn_info ("removing from active", i_ptr); | |
b8698a0f | 2367 | |
dabd47e7 | 2368 | active_local_stores_len--; |
6fb5fa3c DB |
2369 | if (last) |
2370 | last->next_local_store = i_ptr->next_local_store; | |
2371 | else | |
2372 | active_local_stores = i_ptr->next_local_store; | |
2373 | } | |
2374 | else | |
2375 | last = i_ptr; | |
2376 | i_ptr = i_ptr->next_local_store; | |
2377 | } | |
2378 | } | |
2379 | return 0; | |
2380 | } | |
2381 | ||
b8698a0f | 2382 | /* A for_each_rtx callback in which DATA points the INSN_INFO for |
6fb5fa3c DB |
2383 | as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns |
2384 | true for any part of *LOC. */ | |
2385 | ||
2386 | static void | |
2387 | check_mem_read_use (rtx *loc, void *data) | |
2388 | { | |
2389 | for_each_rtx (loc, check_mem_read_rtx, data); | |
2390 | } | |
2391 | ||
8dd5516b JJ |
2392 | |
2393 | /* Get arguments passed to CALL_INSN. Return TRUE if successful. | |
2394 | So far it only handles arguments passed in registers. */ | |
2395 | ||
2396 | static bool | |
2397 | get_call_args (rtx call_insn, tree fn, rtx *args, int nargs) | |
2398 | { | |
d5cc9181 JR |
2399 | CUMULATIVE_ARGS args_so_far_v; |
2400 | cumulative_args_t args_so_far; | |
8dd5516b JJ |
2401 | tree arg; |
2402 | int idx; | |
2403 | ||
d5cc9181 JR |
2404 | INIT_CUMULATIVE_ARGS (args_so_far_v, TREE_TYPE (fn), NULL_RTX, 0, 3); |
2405 | args_so_far = pack_cumulative_args (&args_so_far_v); | |
8dd5516b JJ |
2406 | |
2407 | arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2408 | for (idx = 0; | |
2409 | arg != void_list_node && idx < nargs; | |
2410 | arg = TREE_CHAIN (arg), idx++) | |
2411 | { | |
2412 | enum machine_mode mode = TYPE_MODE (TREE_VALUE (arg)); | |
3c07301f | 2413 | rtx reg, link, tmp; |
d5cc9181 | 2414 | reg = targetm.calls.function_arg (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2415 | if (!reg || !REG_P (reg) || GET_MODE (reg) != mode |
2416 | || GET_MODE_CLASS (mode) != MODE_INT) | |
2417 | return false; | |
2418 | ||
2419 | for (link = CALL_INSN_FUNCTION_USAGE (call_insn); | |
2420 | link; | |
2421 | link = XEXP (link, 1)) | |
2422 | if (GET_CODE (XEXP (link, 0)) == USE) | |
2423 | { | |
2424 | args[idx] = XEXP (XEXP (link, 0), 0); | |
2425 | if (REG_P (args[idx]) | |
2426 | && REGNO (args[idx]) == REGNO (reg) | |
2427 | && (GET_MODE (args[idx]) == mode | |
2428 | || (GET_MODE_CLASS (GET_MODE (args[idx])) == MODE_INT | |
2429 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2430 | <= UNITS_PER_WORD) | |
2431 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2432 | > GET_MODE_SIZE (mode))))) | |
2433 | break; | |
2434 | } | |
2435 | if (!link) | |
2436 | return false; | |
2437 | ||
2438 | tmp = cselib_expand_value_rtx (args[idx], scratch, 5); | |
2439 | if (GET_MODE (args[idx]) != mode) | |
2440 | { | |
2441 | if (!tmp || !CONST_INT_P (tmp)) | |
2442 | return false; | |
6d26322f | 2443 | tmp = gen_int_mode (INTVAL (tmp), mode); |
8dd5516b JJ |
2444 | } |
2445 | if (tmp) | |
2446 | args[idx] = tmp; | |
2447 | ||
d5cc9181 | 2448 | targetm.calls.function_arg_advance (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2449 | } |
2450 | if (arg != void_list_node || idx != nargs) | |
2451 | return false; | |
2452 | return true; | |
2453 | } | |
2454 | ||
9e582b1d JR |
2455 | /* Return a bitmap of the fixed registers contained in IN. */ |
2456 | ||
2457 | static bitmap | |
2458 | copy_fixed_regs (const_bitmap in) | |
2459 | { | |
2460 | bitmap ret; | |
2461 | ||
2462 | ret = ALLOC_REG_SET (NULL); | |
2463 | bitmap_and (ret, in, fixed_reg_set_regset); | |
2464 | return ret; | |
2465 | } | |
8dd5516b | 2466 | |
6fb5fa3c DB |
2467 | /* Apply record_store to all candidate stores in INSN. Mark INSN |
2468 | if some part of it is not a candidate store and assigns to a | |
2469 | non-register target. */ | |
2470 | ||
2471 | static void | |
2472 | scan_insn (bb_info_t bb_info, rtx insn) | |
2473 | { | |
2474 | rtx body; | |
f883e0a7 | 2475 | insn_info_t insn_info = (insn_info_t) pool_alloc (insn_info_pool); |
6fb5fa3c DB |
2476 | int mems_found = 0; |
2477 | memset (insn_info, 0, sizeof (struct insn_info)); | |
2478 | ||
2479 | if (dump_file) | |
2480 | fprintf (dump_file, "\n**scanning insn=%d\n", | |
2481 | INSN_UID (insn)); | |
2482 | ||
2483 | insn_info->prev_insn = bb_info->last_insn; | |
2484 | insn_info->insn = insn; | |
2485 | bb_info->last_insn = insn_info; | |
b8698a0f | 2486 | |
b5b8b0ac AO |
2487 | if (DEBUG_INSN_P (insn)) |
2488 | { | |
2489 | insn_info->cannot_delete = true; | |
2490 | return; | |
2491 | } | |
6fb5fa3c | 2492 | |
0d52bcc1 | 2493 | /* Cselib clears the table for this case, so we have to essentially |
6fb5fa3c DB |
2494 | do the same. */ |
2495 | if (NONJUMP_INSN_P (insn) | |
2496 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2497 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2498 | { | |
2499 | add_wild_read (bb_info); | |
2500 | insn_info->cannot_delete = true; | |
2501 | return; | |
2502 | } | |
2503 | ||
2504 | /* Look at all of the uses in the insn. */ | |
2505 | note_uses (&PATTERN (insn), check_mem_read_use, bb_info); | |
2506 | ||
2507 | if (CALL_P (insn)) | |
2508 | { | |
8dd5516b JJ |
2509 | bool const_call; |
2510 | tree memset_call = NULL_TREE; | |
2511 | ||
6fb5fa3c | 2512 | insn_info->cannot_delete = true; |
50f0f366 | 2513 | |
6fb5fa3c | 2514 | /* Const functions cannot do anything bad i.e. read memory, |
50f0f366 | 2515 | however, they can read their parameters which may have |
8dd5516b JJ |
2516 | been pushed onto the stack. |
2517 | memset and bzero don't read memory either. */ | |
2518 | const_call = RTL_CONST_CALL_P (insn); | |
2519 | if (!const_call) | |
2520 | { | |
da4fdf2d SB |
2521 | rtx call = get_call_rtx_from (insn); |
2522 | if (call && GET_CODE (XEXP (XEXP (call, 0), 0)) == SYMBOL_REF) | |
8dd5516b JJ |
2523 | { |
2524 | rtx symbol = XEXP (XEXP (call, 0), 0); | |
2525 | if (SYMBOL_REF_DECL (symbol) | |
2526 | && TREE_CODE (SYMBOL_REF_DECL (symbol)) == FUNCTION_DECL) | |
2527 | { | |
2528 | if ((DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (symbol)) | |
2529 | == BUILT_IN_NORMAL | |
2530 | && (DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol)) | |
2531 | == BUILT_IN_MEMSET)) | |
2532 | || SYMBOL_REF_DECL (symbol) == block_clear_fn) | |
2533 | memset_call = SYMBOL_REF_DECL (symbol); | |
2534 | } | |
2535 | } | |
2536 | } | |
2537 | if (const_call || memset_call) | |
6fb5fa3c DB |
2538 | { |
2539 | insn_info_t i_ptr = active_local_stores; | |
2540 | insn_info_t last = NULL; | |
2541 | ||
2542 | if (dump_file) | |
8dd5516b JJ |
2543 | fprintf (dump_file, "%s call %d\n", |
2544 | const_call ? "const" : "memset", INSN_UID (insn)); | |
6fb5fa3c | 2545 | |
64520bdc EB |
2546 | /* See the head comment of the frame_read field. */ |
2547 | if (reload_completed) | |
2548 | insn_info->frame_read = true; | |
2549 | ||
2550 | /* Loop over the active stores and remove those which are | |
2551 | killed by the const function call. */ | |
6fb5fa3c DB |
2552 | while (i_ptr) |
2553 | { | |
64520bdc EB |
2554 | bool remove_store = false; |
2555 | ||
2556 | /* The stack pointer based stores are always killed. */ | |
50f0f366 | 2557 | if (i_ptr->stack_pointer_based) |
64520bdc EB |
2558 | remove_store = true; |
2559 | ||
2560 | /* If the frame is read, the frame related stores are killed. */ | |
2561 | else if (insn_info->frame_read) | |
2562 | { | |
2563 | store_info_t store_info = i_ptr->store_rec; | |
2564 | ||
2565 | /* Skip the clobbers. */ | |
2566 | while (!store_info->is_set) | |
2567 | store_info = store_info->next; | |
2568 | ||
2569 | if (store_info->group_id >= 0 | |
2570 | && VEC_index (group_info_t, rtx_group_vec, | |
2571 | store_info->group_id)->frame_related) | |
2572 | remove_store = true; | |
2573 | } | |
2574 | ||
2575 | if (remove_store) | |
6fb5fa3c DB |
2576 | { |
2577 | if (dump_file) | |
2578 | dump_insn_info ("removing from active", i_ptr); | |
b8698a0f | 2579 | |
dabd47e7 | 2580 | active_local_stores_len--; |
6fb5fa3c DB |
2581 | if (last) |
2582 | last->next_local_store = i_ptr->next_local_store; | |
2583 | else | |
2584 | active_local_stores = i_ptr->next_local_store; | |
2585 | } | |
2586 | else | |
2587 | last = i_ptr; | |
64520bdc | 2588 | |
6fb5fa3c DB |
2589 | i_ptr = i_ptr->next_local_store; |
2590 | } | |
8dd5516b JJ |
2591 | |
2592 | if (memset_call) | |
2593 | { | |
2594 | rtx args[3]; | |
2595 | if (get_call_args (insn, memset_call, args, 3) | |
2596 | && CONST_INT_P (args[1]) | |
2597 | && CONST_INT_P (args[2]) | |
2598 | && INTVAL (args[2]) > 0) | |
2599 | { | |
2600 | rtx mem = gen_rtx_MEM (BLKmode, args[0]); | |
f5541398 | 2601 | set_mem_size (mem, INTVAL (args[2])); |
8dd5516b JJ |
2602 | body = gen_rtx_SET (VOIDmode, mem, args[1]); |
2603 | mems_found += record_store (body, bb_info); | |
2604 | if (dump_file) | |
2605 | fprintf (dump_file, "handling memset as BLKmode store\n"); | |
2606 | if (mems_found == 1) | |
2607 | { | |
dabd47e7 JJ |
2608 | if (active_local_stores_len++ |
2609 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2610 | { | |
2611 | active_local_stores_len = 1; | |
2612 | active_local_stores = NULL; | |
2613 | } | |
9e582b1d JR |
2614 | insn_info->fixed_regs_live |
2615 | = copy_fixed_regs (bb_info->regs_live); | |
8dd5516b JJ |
2616 | insn_info->next_local_store = active_local_stores; |
2617 | active_local_stores = insn_info; | |
2618 | } | |
2619 | } | |
2620 | } | |
6fb5fa3c DB |
2621 | } |
2622 | ||
50f0f366 | 2623 | else |
d26c7090 ER |
2624 | /* Every other call, including pure functions, may read any memory |
2625 | that is not relative to the frame. */ | |
2626 | add_non_frame_wild_read (bb_info); | |
50f0f366 | 2627 | |
6fb5fa3c DB |
2628 | return; |
2629 | } | |
2630 | ||
2631 | /* Assuming that there are sets in these insns, we cannot delete | |
2632 | them. */ | |
2633 | if ((GET_CODE (PATTERN (insn)) == CLOBBER) | |
0a64eeca | 2634 | || volatile_refs_p (PATTERN (insn)) |
2da02156 | 2635 | || (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) |
6fb5fa3c DB |
2636 | || (RTX_FRAME_RELATED_P (insn)) |
2637 | || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX)) | |
2638 | insn_info->cannot_delete = true; | |
b8698a0f | 2639 | |
6fb5fa3c DB |
2640 | body = PATTERN (insn); |
2641 | if (GET_CODE (body) == PARALLEL) | |
2642 | { | |
2643 | int i; | |
2644 | for (i = 0; i < XVECLEN (body, 0); i++) | |
2645 | mems_found += record_store (XVECEXP (body, 0, i), bb_info); | |
2646 | } | |
2647 | else | |
2648 | mems_found += record_store (body, bb_info); | |
2649 | ||
2650 | if (dump_file) | |
b8698a0f | 2651 | fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n", |
6fb5fa3c DB |
2652 | mems_found, insn_info->cannot_delete ? "true" : "false"); |
2653 | ||
8dd5516b JJ |
2654 | /* If we found some sets of mems, add it into the active_local_stores so |
2655 | that it can be locally deleted if found dead or used for | |
2656 | replace_read and redundant constant store elimination. Otherwise mark | |
2657 | it as cannot delete. This simplifies the processing later. */ | |
2658 | if (mems_found == 1) | |
6fb5fa3c | 2659 | { |
dabd47e7 JJ |
2660 | if (active_local_stores_len++ |
2661 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2662 | { | |
2663 | active_local_stores_len = 1; | |
2664 | active_local_stores = NULL; | |
2665 | } | |
9e582b1d | 2666 | insn_info->fixed_regs_live = copy_fixed_regs (bb_info->regs_live); |
6fb5fa3c DB |
2667 | insn_info->next_local_store = active_local_stores; |
2668 | active_local_stores = insn_info; | |
2669 | } | |
2670 | else | |
2671 | insn_info->cannot_delete = true; | |
2672 | } | |
2673 | ||
2674 | ||
2675 | /* Remove BASE from the set of active_local_stores. This is a | |
2676 | callback from cselib that is used to get rid of the stores in | |
2677 | active_local_stores. */ | |
2678 | ||
2679 | static void | |
2680 | remove_useless_values (cselib_val *base) | |
2681 | { | |
2682 | insn_info_t insn_info = active_local_stores; | |
2683 | insn_info_t last = NULL; | |
2684 | ||
2685 | while (insn_info) | |
2686 | { | |
2687 | store_info_t store_info = insn_info->store_rec; | |
60564289 | 2688 | bool del = false; |
6fb5fa3c DB |
2689 | |
2690 | /* If ANY of the store_infos match the cselib group that is | |
2691 | being deleted, then the insn can not be deleted. */ | |
2692 | while (store_info) | |
2693 | { | |
b8698a0f | 2694 | if ((store_info->group_id == -1) |
6fb5fa3c DB |
2695 | && (store_info->cse_base == base)) |
2696 | { | |
60564289 | 2697 | del = true; |
6fb5fa3c DB |
2698 | break; |
2699 | } | |
2700 | store_info = store_info->next; | |
2701 | } | |
2702 | ||
60564289 | 2703 | if (del) |
6fb5fa3c | 2704 | { |
dabd47e7 | 2705 | active_local_stores_len--; |
6fb5fa3c DB |
2706 | if (last) |
2707 | last->next_local_store = insn_info->next_local_store; | |
2708 | else | |
2709 | active_local_stores = insn_info->next_local_store; | |
2710 | free_store_info (insn_info); | |
2711 | } | |
2712 | else | |
2713 | last = insn_info; | |
b8698a0f | 2714 | |
6fb5fa3c DB |
2715 | insn_info = insn_info->next_local_store; |
2716 | } | |
2717 | } | |
2718 | ||
2719 | ||
2720 | /* Do all of step 1. */ | |
2721 | ||
2722 | static void | |
2723 | dse_step1 (void) | |
2724 | { | |
2725 | basic_block bb; | |
3f9b14ff | 2726 | bitmap regs_live = BITMAP_ALLOC (®_obstack); |
b8698a0f | 2727 | |
457eeaae | 2728 | cselib_init (0); |
6fb5fa3c DB |
2729 | all_blocks = BITMAP_ALLOC (NULL); |
2730 | bitmap_set_bit (all_blocks, ENTRY_BLOCK); | |
2731 | bitmap_set_bit (all_blocks, EXIT_BLOCK); | |
2732 | ||
2733 | FOR_ALL_BB (bb) | |
2734 | { | |
2735 | insn_info_t ptr; | |
f883e0a7 | 2736 | bb_info_t bb_info = (bb_info_t) pool_alloc (bb_info_pool); |
6fb5fa3c DB |
2737 | |
2738 | memset (bb_info, 0, sizeof (struct bb_info)); | |
2739 | bitmap_set_bit (all_blocks, bb->index); | |
02b47899 KZ |
2740 | bb_info->regs_live = regs_live; |
2741 | ||
2742 | bitmap_copy (regs_live, DF_LR_IN (bb)); | |
2743 | df_simulate_initialize_forwards (bb, regs_live); | |
6fb5fa3c DB |
2744 | |
2745 | bb_table[bb->index] = bb_info; | |
2746 | cselib_discard_hook = remove_useless_values; | |
2747 | ||
2748 | if (bb->index >= NUM_FIXED_BLOCKS) | |
2749 | { | |
2750 | rtx insn; | |
2751 | ||
2752 | cse_store_info_pool | |
b8698a0f | 2753 | = create_alloc_pool ("cse_store_info_pool", |
6fb5fa3c DB |
2754 | sizeof (struct store_info), 100); |
2755 | active_local_stores = NULL; | |
dabd47e7 | 2756 | active_local_stores_len = 0; |
6fb5fa3c | 2757 | cselib_clear_table (); |
b8698a0f | 2758 | |
6fb5fa3c DB |
2759 | /* Scan the insns. */ |
2760 | FOR_BB_INSNS (bb, insn) | |
2761 | { | |
2762 | if (INSN_P (insn)) | |
2763 | scan_insn (bb_info, insn); | |
2764 | cselib_process_insn (insn); | |
02b47899 KZ |
2765 | if (INSN_P (insn)) |
2766 | df_simulate_one_insn_forwards (bb, insn, regs_live); | |
6fb5fa3c | 2767 | } |
b8698a0f | 2768 | |
6fb5fa3c DB |
2769 | /* This is something of a hack, because the global algorithm |
2770 | is supposed to take care of the case where stores go dead | |
2771 | at the end of the function. However, the global | |
2772 | algorithm must take a more conservative view of block | |
2773 | mode reads than the local alg does. So to get the case | |
2774 | where you have a store to the frame followed by a non | |
0d52bcc1 | 2775 | overlapping block more read, we look at the active local |
6fb5fa3c DB |
2776 | stores at the end of the function and delete all of the |
2777 | frame and spill based ones. */ | |
2778 | if (stores_off_frame_dead_at_return | |
2779 | && (EDGE_COUNT (bb->succs) == 0 | |
2780 | || (single_succ_p (bb) | |
2781 | && single_succ (bb) == EXIT_BLOCK_PTR | |
e3b5732b | 2782 | && ! crtl->calls_eh_return))) |
6fb5fa3c DB |
2783 | { |
2784 | insn_info_t i_ptr = active_local_stores; | |
2785 | while (i_ptr) | |
2786 | { | |
2787 | store_info_t store_info = i_ptr->store_rec; | |
2788 | ||
2789 | /* Skip the clobbers. */ | |
2790 | while (!store_info->is_set) | |
2791 | store_info = store_info->next; | |
8dd5516b | 2792 | if (store_info->alias_set && !i_ptr->cannot_delete) |
6fb5fa3c | 2793 | delete_dead_store_insn (i_ptr); |
b8698a0f | 2794 | else |
6fb5fa3c DB |
2795 | if (store_info->group_id >= 0) |
2796 | { | |
b8698a0f | 2797 | group_info_t group |
6fb5fa3c | 2798 | = VEC_index (group_info_t, rtx_group_vec, store_info->group_id); |
8dd5516b | 2799 | if (group->frame_related && !i_ptr->cannot_delete) |
6fb5fa3c DB |
2800 | delete_dead_store_insn (i_ptr); |
2801 | } | |
2802 | ||
2803 | i_ptr = i_ptr->next_local_store; | |
2804 | } | |
2805 | } | |
2806 | ||
2807 | /* Get rid of the loads that were discovered in | |
2808 | replace_read. Cselib is finished with this block. */ | |
2809 | while (deferred_change_list) | |
2810 | { | |
2811 | deferred_change_t next = deferred_change_list->next; | |
2812 | ||
2813 | /* There is no reason to validate this change. That was | |
2814 | done earlier. */ | |
2815 | *deferred_change_list->loc = deferred_change_list->reg; | |
2816 | pool_free (deferred_change_pool, deferred_change_list); | |
2817 | deferred_change_list = next; | |
2818 | } | |
2819 | ||
2820 | /* Get rid of all of the cselib based store_infos in this | |
2821 | block and mark the containing insns as not being | |
2822 | deletable. */ | |
2823 | ptr = bb_info->last_insn; | |
2824 | while (ptr) | |
2825 | { | |
2826 | if (ptr->contains_cselib_groups) | |
8dd5516b JJ |
2827 | { |
2828 | store_info_t s_info = ptr->store_rec; | |
2829 | while (s_info && !s_info->is_set) | |
2830 | s_info = s_info->next; | |
2831 | if (s_info | |
2832 | && s_info->redundant_reason | |
2833 | && s_info->redundant_reason->insn | |
2834 | && !ptr->cannot_delete) | |
2835 | { | |
2836 | if (dump_file) | |
2837 | fprintf (dump_file, "Locally deleting insn %d " | |
2838 | "because insn %d stores the " | |
2839 | "same value and couldn't be " | |
2840 | "eliminated\n", | |
2841 | INSN_UID (ptr->insn), | |
2842 | INSN_UID (s_info->redundant_reason->insn)); | |
2843 | delete_dead_store_insn (ptr); | |
2844 | } | |
2845 | if (s_info) | |
2846 | s_info->redundant_reason = NULL; | |
2847 | free_store_info (ptr); | |
2848 | } | |
2849 | else | |
2850 | { | |
2851 | store_info_t s_info; | |
2852 | ||
2853 | /* Free at least positions_needed bitmaps. */ | |
2854 | for (s_info = ptr->store_rec; s_info; s_info = s_info->next) | |
2855 | if (s_info->is_large) | |
2856 | { | |
dc491a25 | 2857 | BITMAP_FREE (s_info->positions_needed.large.bmap); |
8dd5516b JJ |
2858 | s_info->is_large = false; |
2859 | } | |
2860 | } | |
6fb5fa3c DB |
2861 | ptr = ptr->prev_insn; |
2862 | } | |
2863 | ||
2864 | free_alloc_pool (cse_store_info_pool); | |
2865 | } | |
02b47899 | 2866 | bb_info->regs_live = NULL; |
6fb5fa3c DB |
2867 | } |
2868 | ||
02b47899 | 2869 | BITMAP_FREE (regs_live); |
6fb5fa3c | 2870 | cselib_finish (); |
703c8606 | 2871 | rtx_group_table.empty (); |
6fb5fa3c DB |
2872 | } |
2873 | ||
2874 | \f | |
2875 | /*---------------------------------------------------------------------------- | |
2876 | Second step. | |
2877 | ||
2878 | Assign each byte position in the stores that we are going to | |
2879 | analyze globally to a position in the bitmaps. Returns true if | |
6ed3da00 | 2880 | there are any bit positions assigned. |
6fb5fa3c DB |
2881 | ----------------------------------------------------------------------------*/ |
2882 | ||
2883 | static void | |
2884 | dse_step2_init (void) | |
2885 | { | |
2886 | unsigned int i; | |
2887 | group_info_t group; | |
2888 | ||
ac47786e | 2889 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c DB |
2890 | { |
2891 | /* For all non stack related bases, we only consider a store to | |
2892 | be deletable if there are two or more stores for that | |
2893 | position. This is because it takes one store to make the | |
2894 | other store redundant. However, for the stores that are | |
2895 | stack related, we consider them if there is only one store | |
2896 | for the position. We do this because the stack related | |
2897 | stores can be deleted if their is no read between them and | |
2898 | the end of the function. | |
b8698a0f | 2899 | |
6fb5fa3c DB |
2900 | To make this work in the current framework, we take the stack |
2901 | related bases add all of the bits from store1 into store2. | |
2902 | This has the effect of making the eligible even if there is | |
2903 | only one store. */ | |
2904 | ||
2905 | if (stores_off_frame_dead_at_return && group->frame_related) | |
2906 | { | |
2907 | bitmap_ior_into (group->store2_n, group->store1_n); | |
2908 | bitmap_ior_into (group->store2_p, group->store1_p); | |
2909 | if (dump_file) | |
b8698a0f | 2910 | fprintf (dump_file, "group %d is frame related ", i); |
6fb5fa3c DB |
2911 | } |
2912 | ||
2913 | group->offset_map_size_n++; | |
3f9b14ff SB |
2914 | group->offset_map_n = XOBNEWVEC (&dse_obstack, int, |
2915 | group->offset_map_size_n); | |
6fb5fa3c | 2916 | group->offset_map_size_p++; |
3f9b14ff SB |
2917 | group->offset_map_p = XOBNEWVEC (&dse_obstack, int, |
2918 | group->offset_map_size_p); | |
6fb5fa3c DB |
2919 | group->process_globally = false; |
2920 | if (dump_file) | |
2921 | { | |
b8698a0f | 2922 | fprintf (dump_file, "group %d(%d+%d): ", i, |
6fb5fa3c DB |
2923 | (int)bitmap_count_bits (group->store2_n), |
2924 | (int)bitmap_count_bits (group->store2_p)); | |
2925 | bitmap_print (dump_file, group->store2_n, "n ", " "); | |
2926 | bitmap_print (dump_file, group->store2_p, "p ", "\n"); | |
2927 | } | |
2928 | } | |
2929 | } | |
2930 | ||
2931 | ||
2932 | /* Init the offset tables for the normal case. */ | |
2933 | ||
2934 | static bool | |
2935 | dse_step2_nospill (void) | |
2936 | { | |
2937 | unsigned int i; | |
2938 | group_info_t group; | |
2939 | /* Position 0 is unused because 0 is used in the maps to mean | |
2940 | unused. */ | |
2941 | current_position = 1; | |
ac47786e | 2942 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c DB |
2943 | { |
2944 | bitmap_iterator bi; | |
2945 | unsigned int j; | |
2946 | ||
2947 | if (group == clear_alias_group) | |
2948 | continue; | |
2949 | ||
2950 | memset (group->offset_map_n, 0, sizeof(int) * group->offset_map_size_n); | |
2951 | memset (group->offset_map_p, 0, sizeof(int) * group->offset_map_size_p); | |
2952 | bitmap_clear (group->group_kill); | |
2953 | ||
2954 | EXECUTE_IF_SET_IN_BITMAP (group->store2_n, 0, j, bi) | |
2955 | { | |
2956 | bitmap_set_bit (group->group_kill, current_position); | |
d26c7090 ER |
2957 | if (bitmap_bit_p (group->escaped_n, j)) |
2958 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2959 | group->offset_map_n[j] = current_position++; |
2960 | group->process_globally = true; | |
2961 | } | |
2962 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2963 | { | |
b8698a0f | 2964 | bitmap_set_bit (group->group_kill, current_position); |
d26c7090 ER |
2965 | if (bitmap_bit_p (group->escaped_p, j)) |
2966 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2967 | group->offset_map_p[j] = current_position++; |
2968 | group->process_globally = true; | |
2969 | } | |
2970 | } | |
2971 | return current_position != 1; | |
2972 | } | |
2973 | ||
2974 | ||
2975 | /* Init the offset tables for the spill case. */ | |
2976 | ||
2977 | static bool | |
2978 | dse_step2_spill (void) | |
2979 | { | |
2980 | unsigned int j; | |
2981 | group_info_t group = clear_alias_group; | |
2982 | bitmap_iterator bi; | |
2983 | ||
2984 | /* Position 0 is unused because 0 is used in the maps to mean | |
2985 | unused. */ | |
2986 | current_position = 1; | |
2987 | ||
2988 | if (dump_file) | |
2989 | { | |
b8698a0f | 2990 | bitmap_print (dump_file, clear_alias_sets, |
6fb5fa3c | 2991 | "clear alias sets ", "\n"); |
b8698a0f | 2992 | bitmap_print (dump_file, disqualified_clear_alias_sets, |
6fb5fa3c DB |
2993 | "disqualified clear alias sets ", "\n"); |
2994 | } | |
2995 | ||
2996 | memset (group->offset_map_n, 0, sizeof(int) * group->offset_map_size_n); | |
2997 | memset (group->offset_map_p, 0, sizeof(int) * group->offset_map_size_p); | |
2998 | bitmap_clear (group->group_kill); | |
b8698a0f | 2999 | |
6fb5fa3c DB |
3000 | /* Remove the disqualified positions from the store2_p set. */ |
3001 | bitmap_and_compl_into (group->store2_p, disqualified_clear_alias_sets); | |
b8698a0f | 3002 | |
6fb5fa3c DB |
3003 | /* We do not need to process the store2_n set because |
3004 | alias_sets are always positive. */ | |
3005 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
3006 | { | |
b8698a0f | 3007 | bitmap_set_bit (group->group_kill, current_position); |
6fb5fa3c DB |
3008 | group->offset_map_p[j] = current_position++; |
3009 | group->process_globally = true; | |
3010 | } | |
3011 | ||
3012 | return current_position != 1; | |
3013 | } | |
3014 | ||
3015 | ||
3016 | \f | |
3017 | /*---------------------------------------------------------------------------- | |
3018 | Third step. | |
b8698a0f | 3019 | |
6fb5fa3c DB |
3020 | Build the bit vectors for the transfer functions. |
3021 | ----------------------------------------------------------------------------*/ | |
3022 | ||
3023 | ||
6fb5fa3c DB |
3024 | /* Look up the bitmap index for OFFSET in GROUP_INFO. If it is not |
3025 | there, return 0. */ | |
3026 | ||
3027 | static int | |
3028 | get_bitmap_index (group_info_t group_info, HOST_WIDE_INT offset) | |
3029 | { | |
3030 | if (offset < 0) | |
3031 | { | |
3032 | HOST_WIDE_INT offset_p = -offset; | |
3033 | if (offset_p >= group_info->offset_map_size_n) | |
3034 | return 0; | |
3035 | return group_info->offset_map_n[offset_p]; | |
3036 | } | |
3037 | else | |
3038 | { | |
3039 | if (offset >= group_info->offset_map_size_p) | |
3040 | return 0; | |
3041 | return group_info->offset_map_p[offset]; | |
3042 | } | |
3043 | } | |
3044 | ||
3045 | ||
3046 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
3047 | may be NULL. */ | |
3048 | ||
b8698a0f | 3049 | static void |
6fb5fa3c DB |
3050 | scan_stores_nospill (store_info_t store_info, bitmap gen, bitmap kill) |
3051 | { | |
3052 | while (store_info) | |
3053 | { | |
3054 | HOST_WIDE_INT i; | |
b8698a0f | 3055 | group_info_t group_info |
6fb5fa3c DB |
3056 | = VEC_index (group_info_t, rtx_group_vec, store_info->group_id); |
3057 | if (group_info->process_globally) | |
3058 | for (i = store_info->begin; i < store_info->end; i++) | |
3059 | { | |
3060 | int index = get_bitmap_index (group_info, i); | |
3061 | if (index != 0) | |
3062 | { | |
3063 | bitmap_set_bit (gen, index); | |
3064 | if (kill) | |
3065 | bitmap_clear_bit (kill, index); | |
3066 | } | |
3067 | } | |
3068 | store_info = store_info->next; | |
3069 | } | |
3070 | } | |
3071 | ||
3072 | ||
3073 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
3074 | may be NULL. */ | |
3075 | ||
b8698a0f | 3076 | static void |
6fb5fa3c DB |
3077 | scan_stores_spill (store_info_t store_info, bitmap gen, bitmap kill) |
3078 | { | |
3079 | while (store_info) | |
3080 | { | |
3081 | if (store_info->alias_set) | |
3082 | { | |
b8698a0f | 3083 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3084 | store_info->alias_set); |
3085 | if (index != 0) | |
3086 | { | |
3087 | bitmap_set_bit (gen, index); | |
3088 | if (kill) | |
3089 | bitmap_clear_bit (kill, index); | |
3090 | } | |
3091 | } | |
3092 | store_info = store_info->next; | |
3093 | } | |
3094 | } | |
3095 | ||
3096 | ||
3097 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3098 | may be NULL. */ | |
3099 | ||
3100 | static void | |
3101 | scan_reads_nospill (insn_info_t insn_info, bitmap gen, bitmap kill) | |
3102 | { | |
3103 | read_info_t read_info = insn_info->read_rec; | |
3104 | int i; | |
3105 | group_info_t group; | |
3106 | ||
64520bdc EB |
3107 | /* If this insn reads the frame, kill all the frame related stores. */ |
3108 | if (insn_info->frame_read) | |
3109 | { | |
ac47786e | 3110 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
64520bdc EB |
3111 | if (group->process_globally && group->frame_related) |
3112 | { | |
3113 | if (kill) | |
3114 | bitmap_ior_into (kill, group->group_kill); | |
b8698a0f | 3115 | bitmap_and_compl_into (gen, group->group_kill); |
64520bdc EB |
3116 | } |
3117 | } | |
d26c7090 ER |
3118 | if (insn_info->non_frame_wild_read) |
3119 | { | |
3120 | /* Kill all non-frame related stores. Kill all stores of variables that | |
3121 | escape. */ | |
3122 | if (kill) | |
3123 | bitmap_ior_into (kill, kill_on_calls); | |
3124 | bitmap_and_compl_into (gen, kill_on_calls); | |
3125 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) | |
3126 | if (group->process_globally && !group->frame_related) | |
3127 | { | |
3128 | if (kill) | |
3129 | bitmap_ior_into (kill, group->group_kill); | |
3130 | bitmap_and_compl_into (gen, group->group_kill); | |
3131 | } | |
3132 | } | |
6fb5fa3c DB |
3133 | while (read_info) |
3134 | { | |
ac47786e | 3135 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c DB |
3136 | { |
3137 | if (group->process_globally) | |
3138 | { | |
3139 | if (i == read_info->group_id) | |
3140 | { | |
3141 | if (read_info->begin > read_info->end) | |
3142 | { | |
3143 | /* Begin > end for block mode reads. */ | |
3144 | if (kill) | |
3145 | bitmap_ior_into (kill, group->group_kill); | |
3146 | bitmap_and_compl_into (gen, group->group_kill); | |
3147 | } | |
3148 | else | |
3149 | { | |
3150 | /* The groups are the same, just process the | |
3151 | offsets. */ | |
3152 | HOST_WIDE_INT j; | |
3153 | for (j = read_info->begin; j < read_info->end; j++) | |
3154 | { | |
3155 | int index = get_bitmap_index (group, j); | |
3156 | if (index != 0) | |
3157 | { | |
3158 | if (kill) | |
3159 | bitmap_set_bit (kill, index); | |
3160 | bitmap_clear_bit (gen, index); | |
3161 | } | |
3162 | } | |
3163 | } | |
3164 | } | |
3165 | else | |
3166 | { | |
3167 | /* The groups are different, if the alias sets | |
3168 | conflict, clear the entire group. We only need | |
3169 | to apply this test if the read_info is a cselib | |
3170 | read. Anything with a constant base cannot alias | |
3171 | something else with a different constant | |
3172 | base. */ | |
3173 | if ((read_info->group_id < 0) | |
b8698a0f | 3174 | && canon_true_dependence (group->base_mem, |
d32f725a | 3175 | GET_MODE (group->base_mem), |
6216f94e | 3176 | group->canon_base_addr, |
53d9622b | 3177 | read_info->mem, NULL_RTX)) |
6fb5fa3c DB |
3178 | { |
3179 | if (kill) | |
3180 | bitmap_ior_into (kill, group->group_kill); | |
3181 | bitmap_and_compl_into (gen, group->group_kill); | |
3182 | } | |
3183 | } | |
3184 | } | |
3185 | } | |
b8698a0f | 3186 | |
6fb5fa3c DB |
3187 | read_info = read_info->next; |
3188 | } | |
3189 | } | |
3190 | ||
3191 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3192 | may be NULL. */ | |
3193 | ||
3194 | static void | |
3195 | scan_reads_spill (read_info_t read_info, bitmap gen, bitmap kill) | |
3196 | { | |
3197 | while (read_info) | |
3198 | { | |
3199 | if (read_info->alias_set) | |
3200 | { | |
b8698a0f | 3201 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3202 | read_info->alias_set); |
3203 | if (index != 0) | |
3204 | { | |
3205 | if (kill) | |
3206 | bitmap_set_bit (kill, index); | |
3207 | bitmap_clear_bit (gen, index); | |
3208 | } | |
3209 | } | |
b8698a0f | 3210 | |
6fb5fa3c DB |
3211 | read_info = read_info->next; |
3212 | } | |
3213 | } | |
3214 | ||
3215 | ||
3216 | /* Return the insn in BB_INFO before the first wild read or if there | |
3217 | are no wild reads in the block, return the last insn. */ | |
3218 | ||
3219 | static insn_info_t | |
3220 | find_insn_before_first_wild_read (bb_info_t bb_info) | |
3221 | { | |
3222 | insn_info_t insn_info = bb_info->last_insn; | |
3223 | insn_info_t last_wild_read = NULL; | |
3224 | ||
3225 | while (insn_info) | |
3226 | { | |
3227 | if (insn_info->wild_read) | |
3228 | { | |
3229 | last_wild_read = insn_info->prev_insn; | |
3230 | /* Block starts with wild read. */ | |
3231 | if (!last_wild_read) | |
3232 | return NULL; | |
3233 | } | |
3234 | ||
3235 | insn_info = insn_info->prev_insn; | |
3236 | } | |
3237 | ||
3238 | if (last_wild_read) | |
3239 | return last_wild_read; | |
3240 | else | |
3241 | return bb_info->last_insn; | |
3242 | } | |
3243 | ||
3244 | ||
3245 | /* Scan the insns in BB_INFO starting at PTR and going to the top of | |
3246 | the block in order to build the gen and kill sets for the block. | |
3247 | We start at ptr which may be the last insn in the block or may be | |
3248 | the first insn with a wild read. In the latter case we are able to | |
3249 | skip the rest of the block because it just does not matter: | |
3250 | anything that happens is hidden by the wild read. */ | |
3251 | ||
3252 | static void | |
3253 | dse_step3_scan (bool for_spills, basic_block bb) | |
3254 | { | |
3255 | bb_info_t bb_info = bb_table[bb->index]; | |
3256 | insn_info_t insn_info; | |
3257 | ||
3258 | if (for_spills) | |
3259 | /* There are no wild reads in the spill case. */ | |
3260 | insn_info = bb_info->last_insn; | |
3261 | else | |
3262 | insn_info = find_insn_before_first_wild_read (bb_info); | |
b8698a0f | 3263 | |
6fb5fa3c DB |
3264 | /* In the spill case or in the no_spill case if there is no wild |
3265 | read in the block, we will need a kill set. */ | |
3266 | if (insn_info == bb_info->last_insn) | |
3267 | { | |
3268 | if (bb_info->kill) | |
3269 | bitmap_clear (bb_info->kill); | |
3270 | else | |
3f9b14ff | 3271 | bb_info->kill = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c | 3272 | } |
b8698a0f | 3273 | else |
6fb5fa3c DB |
3274 | if (bb_info->kill) |
3275 | BITMAP_FREE (bb_info->kill); | |
3276 | ||
3277 | while (insn_info) | |
3278 | { | |
3279 | /* There may have been code deleted by the dce pass run before | |
3280 | this phase. */ | |
3281 | if (insn_info->insn && INSN_P (insn_info->insn)) | |
3282 | { | |
b8698a0f | 3283 | /* Process the read(s) last. */ |
6fb5fa3c DB |
3284 | if (for_spills) |
3285 | { | |
3286 | scan_stores_spill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3287 | scan_reads_spill (insn_info->read_rec, bb_info->gen, bb_info->kill); | |
3288 | } | |
3289 | else | |
3290 | { | |
3291 | scan_stores_nospill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3292 | scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill); | |
3293 | } | |
b8698a0f | 3294 | } |
6fb5fa3c DB |
3295 | |
3296 | insn_info = insn_info->prev_insn; | |
3297 | } | |
3298 | } | |
3299 | ||
3300 | ||
3301 | /* Set the gen set of the exit block, and also any block with no | |
3302 | successors that does not have a wild read. */ | |
3303 | ||
3304 | static void | |
3305 | dse_step3_exit_block_scan (bb_info_t bb_info) | |
3306 | { | |
3307 | /* The gen set is all 0's for the exit block except for the | |
3308 | frame_pointer_group. */ | |
b8698a0f | 3309 | |
6fb5fa3c DB |
3310 | if (stores_off_frame_dead_at_return) |
3311 | { | |
3312 | unsigned int i; | |
3313 | group_info_t group; | |
b8698a0f | 3314 | |
ac47786e | 3315 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group) |
6fb5fa3c DB |
3316 | { |
3317 | if (group->process_globally && group->frame_related) | |
3318 | bitmap_ior_into (bb_info->gen, group->group_kill); | |
3319 | } | |
3320 | } | |
3321 | } | |
3322 | ||
3323 | ||
3324 | /* Find all of the blocks that are not backwards reachable from the | |
3325 | exit block or any block with no successors (BB). These are the | |
3326 | infinite loops or infinite self loops. These blocks will still | |
3327 | have their bits set in UNREACHABLE_BLOCKS. */ | |
3328 | ||
3329 | static void | |
3330 | mark_reachable_blocks (sbitmap unreachable_blocks, basic_block bb) | |
3331 | { | |
3332 | edge e; | |
3333 | edge_iterator ei; | |
3334 | ||
3335 | if (TEST_BIT (unreachable_blocks, bb->index)) | |
3336 | { | |
3337 | RESET_BIT (unreachable_blocks, bb->index); | |
3338 | FOR_EACH_EDGE (e, ei, bb->preds) | |
b8698a0f | 3339 | { |
6fb5fa3c | 3340 | mark_reachable_blocks (unreachable_blocks, e->src); |
b8698a0f | 3341 | } |
6fb5fa3c DB |
3342 | } |
3343 | } | |
3344 | ||
3345 | /* Build the transfer functions for the function. */ | |
3346 | ||
3347 | static void | |
3348 | dse_step3 (bool for_spills) | |
3349 | { | |
3350 | basic_block bb; | |
3351 | sbitmap unreachable_blocks = sbitmap_alloc (last_basic_block); | |
3352 | sbitmap_iterator sbi; | |
3353 | bitmap all_ones = NULL; | |
3354 | unsigned int i; | |
b8698a0f | 3355 | |
6fb5fa3c DB |
3356 | sbitmap_ones (unreachable_blocks); |
3357 | ||
3358 | FOR_ALL_BB (bb) | |
3359 | { | |
3360 | bb_info_t bb_info = bb_table[bb->index]; | |
3361 | if (bb_info->gen) | |
3362 | bitmap_clear (bb_info->gen); | |
3363 | else | |
3f9b14ff | 3364 | bb_info->gen = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3365 | |
3366 | if (bb->index == ENTRY_BLOCK) | |
3367 | ; | |
3368 | else if (bb->index == EXIT_BLOCK) | |
3369 | dse_step3_exit_block_scan (bb_info); | |
3370 | else | |
3371 | dse_step3_scan (for_spills, bb); | |
3372 | if (EDGE_COUNT (bb->succs) == 0) | |
3373 | mark_reachable_blocks (unreachable_blocks, bb); | |
3374 | ||
3375 | /* If this is the second time dataflow is run, delete the old | |
3376 | sets. */ | |
3377 | if (bb_info->in) | |
3378 | BITMAP_FREE (bb_info->in); | |
3379 | if (bb_info->out) | |
3380 | BITMAP_FREE (bb_info->out); | |
3381 | } | |
3382 | ||
3383 | /* For any block in an infinite loop, we must initialize the out set | |
3384 | to all ones. This could be expensive, but almost never occurs in | |
3385 | practice. However, it is common in regression tests. */ | |
3386 | EXECUTE_IF_SET_IN_SBITMAP (unreachable_blocks, 0, i, sbi) | |
3387 | { | |
3388 | if (bitmap_bit_p (all_blocks, i)) | |
3389 | { | |
3390 | bb_info_t bb_info = bb_table[i]; | |
3391 | if (!all_ones) | |
3392 | { | |
3393 | unsigned int j; | |
3394 | group_info_t group; | |
3395 | ||
3f9b14ff | 3396 | all_ones = BITMAP_ALLOC (&dse_bitmap_obstack); |
ac47786e | 3397 | FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, j, group) |
6fb5fa3c DB |
3398 | bitmap_ior_into (all_ones, group->group_kill); |
3399 | } | |
3400 | if (!bb_info->out) | |
3401 | { | |
3f9b14ff | 3402 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3403 | bitmap_copy (bb_info->out, all_ones); |
3404 | } | |
3405 | } | |
3406 | } | |
3407 | ||
3408 | if (all_ones) | |
3409 | BITMAP_FREE (all_ones); | |
3410 | sbitmap_free (unreachable_blocks); | |
3411 | } | |
3412 | ||
3413 | ||
3414 | \f | |
3415 | /*---------------------------------------------------------------------------- | |
3416 | Fourth step. | |
3417 | ||
3418 | Solve the bitvector equations. | |
3419 | ----------------------------------------------------------------------------*/ | |
3420 | ||
3421 | ||
3422 | /* Confluence function for blocks with no successors. Create an out | |
3423 | set from the gen set of the exit block. This block logically has | |
3424 | the exit block as a successor. */ | |
3425 | ||
3426 | ||
3427 | ||
3428 | static void | |
3429 | dse_confluence_0 (basic_block bb) | |
3430 | { | |
3431 | bb_info_t bb_info = bb_table[bb->index]; | |
3432 | ||
3433 | if (bb->index == EXIT_BLOCK) | |
3434 | return; | |
3435 | ||
3436 | if (!bb_info->out) | |
3437 | { | |
3f9b14ff | 3438 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3439 | bitmap_copy (bb_info->out, bb_table[EXIT_BLOCK]->gen); |
3440 | } | |
3441 | } | |
3442 | ||
3443 | /* Propagate the information from the in set of the dest of E to the | |
3444 | out set of the src of E. If the various in or out sets are not | |
3445 | there, that means they are all ones. */ | |
3446 | ||
1a0f3fa1 | 3447 | static bool |
6fb5fa3c DB |
3448 | dse_confluence_n (edge e) |
3449 | { | |
3450 | bb_info_t src_info = bb_table[e->src->index]; | |
3451 | bb_info_t dest_info = bb_table[e->dest->index]; | |
3452 | ||
3453 | if (dest_info->in) | |
3454 | { | |
3455 | if (src_info->out) | |
3456 | bitmap_and_into (src_info->out, dest_info->in); | |
3457 | else | |
3458 | { | |
3f9b14ff | 3459 | src_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3460 | bitmap_copy (src_info->out, dest_info->in); |
3461 | } | |
3462 | } | |
1a0f3fa1 | 3463 | return true; |
6fb5fa3c DB |
3464 | } |
3465 | ||
3466 | ||
3467 | /* Propagate the info from the out to the in set of BB_INDEX's basic | |
b8698a0f | 3468 | block. There are three cases: |
6fb5fa3c DB |
3469 | |
3470 | 1) The block has no kill set. In this case the kill set is all | |
3471 | ones. It does not matter what the out set of the block is, none of | |
3472 | the info can reach the top. The only thing that reaches the top is | |
3473 | the gen set and we just copy the set. | |
3474 | ||
3475 | 2) There is a kill set but no out set and bb has successors. In | |
3476 | this case we just return. Eventually an out set will be created and | |
3477 | it is better to wait than to create a set of ones. | |
3478 | ||
3479 | 3) There is both a kill and out set. We apply the obvious transfer | |
3480 | function. | |
3481 | */ | |
3482 | ||
3483 | static bool | |
3484 | dse_transfer_function (int bb_index) | |
3485 | { | |
3486 | bb_info_t bb_info = bb_table[bb_index]; | |
3487 | ||
3488 | if (bb_info->kill) | |
3489 | { | |
3490 | if (bb_info->out) | |
3491 | { | |
3492 | /* Case 3 above. */ | |
3493 | if (bb_info->in) | |
b8698a0f | 3494 | return bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3495 | bb_info->out, bb_info->kill); |
3496 | else | |
3497 | { | |
3f9b14ff | 3498 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
b8698a0f | 3499 | bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3500 | bb_info->out, bb_info->kill); |
3501 | return true; | |
3502 | } | |
3503 | } | |
3504 | else | |
3505 | /* Case 2 above. */ | |
3506 | return false; | |
3507 | } | |
3508 | else | |
3509 | { | |
3510 | /* Case 1 above. If there is already an in set, nothing | |
3511 | happens. */ | |
3512 | if (bb_info->in) | |
3513 | return false; | |
3514 | else | |
3515 | { | |
3f9b14ff | 3516 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3517 | bitmap_copy (bb_info->in, bb_info->gen); |
3518 | return true; | |
3519 | } | |
3520 | } | |
3521 | } | |
3522 | ||
3523 | /* Solve the dataflow equations. */ | |
3524 | ||
3525 | static void | |
3526 | dse_step4 (void) | |
3527 | { | |
b8698a0f L |
3528 | df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0, |
3529 | dse_confluence_n, dse_transfer_function, | |
3530 | all_blocks, df_get_postorder (DF_BACKWARD), | |
6fb5fa3c DB |
3531 | df_get_n_blocks (DF_BACKWARD)); |
3532 | if (dump_file) | |
3533 | { | |
3534 | basic_block bb; | |
3535 | ||
3536 | fprintf (dump_file, "\n\n*** Global dataflow info after analysis.\n"); | |
3537 | FOR_ALL_BB (bb) | |
3538 | { | |
3539 | bb_info_t bb_info = bb_table[bb->index]; | |
3540 | ||
3541 | df_print_bb_index (bb, dump_file); | |
3542 | if (bb_info->in) | |
3543 | bitmap_print (dump_file, bb_info->in, " in: ", "\n"); | |
3544 | else | |
3545 | fprintf (dump_file, " in: *MISSING*\n"); | |
3546 | if (bb_info->gen) | |
3547 | bitmap_print (dump_file, bb_info->gen, " gen: ", "\n"); | |
3548 | else | |
3549 | fprintf (dump_file, " gen: *MISSING*\n"); | |
3550 | if (bb_info->kill) | |
3551 | bitmap_print (dump_file, bb_info->kill, " kill: ", "\n"); | |
3552 | else | |
3553 | fprintf (dump_file, " kill: *MISSING*\n"); | |
3554 | if (bb_info->out) | |
3555 | bitmap_print (dump_file, bb_info->out, " out: ", "\n"); | |
3556 | else | |
3557 | fprintf (dump_file, " out: *MISSING*\n\n"); | |
3558 | } | |
3559 | } | |
3560 | } | |
3561 | ||
3562 | ||
3563 | \f | |
3564 | /*---------------------------------------------------------------------------- | |
3565 | Fifth step. | |
3566 | ||
0d52bcc1 | 3567 | Delete the stores that can only be deleted using the global information. |
6fb5fa3c DB |
3568 | ----------------------------------------------------------------------------*/ |
3569 | ||
3570 | ||
3571 | static void | |
3572 | dse_step5_nospill (void) | |
3573 | { | |
3574 | basic_block bb; | |
3575 | FOR_EACH_BB (bb) | |
3576 | { | |
3577 | bb_info_t bb_info = bb_table[bb->index]; | |
3578 | insn_info_t insn_info = bb_info->last_insn; | |
3579 | bitmap v = bb_info->out; | |
3580 | ||
3581 | while (insn_info) | |
3582 | { | |
3583 | bool deleted = false; | |
3584 | if (dump_file && insn_info->insn) | |
3585 | { | |
3586 | fprintf (dump_file, "starting to process insn %d\n", | |
3587 | INSN_UID (insn_info->insn)); | |
3588 | bitmap_print (dump_file, v, " v: ", "\n"); | |
3589 | } | |
3590 | ||
3591 | /* There may have been code deleted by the dce pass run before | |
3592 | this phase. */ | |
b8698a0f | 3593 | if (insn_info->insn |
6fb5fa3c DB |
3594 | && INSN_P (insn_info->insn) |
3595 | && (!insn_info->cannot_delete) | |
3596 | && (!bitmap_empty_p (v))) | |
3597 | { | |
3598 | store_info_t store_info = insn_info->store_rec; | |
3599 | ||
3600 | /* Try to delete the current insn. */ | |
3601 | deleted = true; | |
b8698a0f | 3602 | |
6fb5fa3c DB |
3603 | /* Skip the clobbers. */ |
3604 | while (!store_info->is_set) | |
3605 | store_info = store_info->next; | |
3606 | ||
3607 | if (store_info->alias_set) | |
3608 | deleted = false; | |
3609 | else | |
3610 | { | |
3611 | HOST_WIDE_INT i; | |
b8698a0f | 3612 | group_info_t group_info |
6fb5fa3c | 3613 | = VEC_index (group_info_t, rtx_group_vec, store_info->group_id); |
b8698a0f | 3614 | |
6fb5fa3c DB |
3615 | for (i = store_info->begin; i < store_info->end; i++) |
3616 | { | |
3617 | int index = get_bitmap_index (group_info, i); | |
b8698a0f | 3618 | |
6fb5fa3c | 3619 | if (dump_file) |
b8698a0f | 3620 | fprintf (dump_file, "i = %d, index = %d\n", (int)i, index); |
6fb5fa3c DB |
3621 | if (index == 0 || !bitmap_bit_p (v, index)) |
3622 | { | |
3623 | if (dump_file) | |
b8698a0f | 3624 | fprintf (dump_file, "failing at i = %d\n", (int)i); |
6fb5fa3c DB |
3625 | deleted = false; |
3626 | break; | |
3627 | } | |
3628 | } | |
3629 | } | |
3630 | if (deleted) | |
3631 | { | |
9e582b1d JR |
3632 | if (dbg_cnt (dse) |
3633 | && check_for_inc_dec_1 (insn_info)) | |
6fb5fa3c | 3634 | { |
6fb5fa3c DB |
3635 | delete_insn (insn_info->insn); |
3636 | insn_info->insn = NULL; | |
3637 | globally_deleted++; | |
3638 | } | |
3639 | } | |
3640 | } | |
3641 | /* We do want to process the local info if the insn was | |
6ed3da00 | 3642 | deleted. For instance, if the insn did a wild read, we |
6fb5fa3c | 3643 | no longer need to trash the info. */ |
b8698a0f | 3644 | if (insn_info->insn |
6fb5fa3c DB |
3645 | && INSN_P (insn_info->insn) |
3646 | && (!deleted)) | |
3647 | { | |
3648 | scan_stores_nospill (insn_info->store_rec, v, NULL); | |
3649 | if (insn_info->wild_read) | |
3650 | { | |
3651 | if (dump_file) | |
3652 | fprintf (dump_file, "wild read\n"); | |
3653 | bitmap_clear (v); | |
3654 | } | |
d26c7090 ER |
3655 | else if (insn_info->read_rec |
3656 | || insn_info->non_frame_wild_read) | |
6fb5fa3c | 3657 | { |
d26c7090 | 3658 | if (dump_file && !insn_info->non_frame_wild_read) |
6fb5fa3c | 3659 | fprintf (dump_file, "regular read\n"); |
d26c7090 ER |
3660 | else if (dump_file) |
3661 | fprintf (dump_file, "non-frame wild read\n"); | |
6fb5fa3c DB |
3662 | scan_reads_nospill (insn_info, v, NULL); |
3663 | } | |
3664 | } | |
b8698a0f | 3665 | |
6fb5fa3c DB |
3666 | insn_info = insn_info->prev_insn; |
3667 | } | |
3668 | } | |
3669 | } | |
3670 | ||
3671 | ||
3672 | static void | |
3673 | dse_step5_spill (void) | |
3674 | { | |
3675 | basic_block bb; | |
3676 | FOR_EACH_BB (bb) | |
3677 | { | |
3678 | bb_info_t bb_info = bb_table[bb->index]; | |
3679 | insn_info_t insn_info = bb_info->last_insn; | |
3680 | bitmap v = bb_info->out; | |
3681 | ||
3682 | while (insn_info) | |
3683 | { | |
3684 | bool deleted = false; | |
3685 | /* There may have been code deleted by the dce pass run before | |
3686 | this phase. */ | |
b8698a0f | 3687 | if (insn_info->insn |
6fb5fa3c DB |
3688 | && INSN_P (insn_info->insn) |
3689 | && (!insn_info->cannot_delete) | |
3690 | && (!bitmap_empty_p (v))) | |
3691 | { | |
3692 | /* Try to delete the current insn. */ | |
3693 | store_info_t store_info = insn_info->store_rec; | |
3694 | deleted = true; | |
b8698a0f | 3695 | |
6fb5fa3c DB |
3696 | while (store_info) |
3697 | { | |
3698 | if (store_info->alias_set) | |
3699 | { | |
b8698a0f | 3700 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3701 | store_info->alias_set); |
3702 | if (index == 0 || !bitmap_bit_p (v, index)) | |
3703 | { | |
3704 | deleted = false; | |
3705 | break; | |
3706 | } | |
3707 | } | |
b8698a0f | 3708 | else |
6fb5fa3c DB |
3709 | deleted = false; |
3710 | store_info = store_info->next; | |
3711 | } | |
9e582b1d JR |
3712 | if (deleted && dbg_cnt (dse) |
3713 | && check_for_inc_dec_1 (insn_info)) | |
6fb5fa3c DB |
3714 | { |
3715 | if (dump_file) | |
b8698a0f | 3716 | fprintf (dump_file, "Spill deleting insn %d\n", |
6fb5fa3c | 3717 | INSN_UID (insn_info->insn)); |
6fb5fa3c DB |
3718 | delete_insn (insn_info->insn); |
3719 | spill_deleted++; | |
3720 | insn_info->insn = NULL; | |
3721 | } | |
3722 | } | |
b8698a0f L |
3723 | |
3724 | if (insn_info->insn | |
6fb5fa3c DB |
3725 | && INSN_P (insn_info->insn) |
3726 | && (!deleted)) | |
3727 | { | |
3728 | scan_stores_spill (insn_info->store_rec, v, NULL); | |
3729 | scan_reads_spill (insn_info->read_rec, v, NULL); | |
3730 | } | |
b8698a0f | 3731 | |
6fb5fa3c DB |
3732 | insn_info = insn_info->prev_insn; |
3733 | } | |
3734 | } | |
3735 | } | |
3736 | ||
3737 | ||
3738 | \f | |
3739 | /*---------------------------------------------------------------------------- | |
3740 | Sixth step. | |
3741 | ||
8dd5516b JJ |
3742 | Delete stores made redundant by earlier stores (which store the same |
3743 | value) that couldn't be eliminated. | |
3744 | ----------------------------------------------------------------------------*/ | |
3745 | ||
3746 | static void | |
3747 | dse_step6 (void) | |
3748 | { | |
3749 | basic_block bb; | |
3750 | ||
3751 | FOR_ALL_BB (bb) | |
3752 | { | |
3753 | bb_info_t bb_info = bb_table[bb->index]; | |
3754 | insn_info_t insn_info = bb_info->last_insn; | |
3755 | ||
3756 | while (insn_info) | |
3757 | { | |
3758 | /* There may have been code deleted by the dce pass run before | |
3759 | this phase. */ | |
3760 | if (insn_info->insn | |
3761 | && INSN_P (insn_info->insn) | |
3762 | && !insn_info->cannot_delete) | |
3763 | { | |
3764 | store_info_t s_info = insn_info->store_rec; | |
3765 | ||
3766 | while (s_info && !s_info->is_set) | |
3767 | s_info = s_info->next; | |
3768 | if (s_info | |
3769 | && s_info->redundant_reason | |
3770 | && s_info->redundant_reason->insn | |
3771 | && INSN_P (s_info->redundant_reason->insn)) | |
3772 | { | |
3773 | rtx rinsn = s_info->redundant_reason->insn; | |
3774 | if (dump_file) | |
3775 | fprintf (dump_file, "Locally deleting insn %d " | |
3776 | "because insn %d stores the " | |
3777 | "same value and couldn't be " | |
3778 | "eliminated\n", | |
3779 | INSN_UID (insn_info->insn), | |
3780 | INSN_UID (rinsn)); | |
3781 | delete_dead_store_insn (insn_info); | |
3782 | } | |
3783 | } | |
3784 | insn_info = insn_info->prev_insn; | |
3785 | } | |
3786 | } | |
3787 | } | |
3788 | \f | |
3789 | /*---------------------------------------------------------------------------- | |
3790 | Seventh step. | |
3791 | ||
b8698a0f | 3792 | Destroy everything left standing. |
6fb5fa3c DB |
3793 | ----------------------------------------------------------------------------*/ |
3794 | ||
b8698a0f | 3795 | static void |
3f9b14ff | 3796 | dse_step7 (void) |
6fb5fa3c | 3797 | { |
3f9b14ff SB |
3798 | bitmap_obstack_release (&dse_bitmap_obstack); |
3799 | obstack_free (&dse_obstack, NULL); | |
370f38e8 | 3800 | |
6fb5fa3c DB |
3801 | if (clear_alias_sets) |
3802 | { | |
3803 | BITMAP_FREE (clear_alias_sets); | |
3804 | BITMAP_FREE (disqualified_clear_alias_sets); | |
3805 | free_alloc_pool (clear_alias_mode_pool); | |
3806 | htab_delete (clear_alias_mode_table); | |
3807 | } | |
3808 | ||
3809 | end_alias_analysis (); | |
3810 | free (bb_table); | |
703c8606 | 3811 | rtx_group_table.dispose (); |
6fb5fa3c DB |
3812 | VEC_free (group_info_t, heap, rtx_group_vec); |
3813 | BITMAP_FREE (all_blocks); | |
3814 | BITMAP_FREE (scratch); | |
3815 | ||
3816 | free_alloc_pool (rtx_store_info_pool); | |
3817 | free_alloc_pool (read_info_pool); | |
3818 | free_alloc_pool (insn_info_pool); | |
3819 | free_alloc_pool (bb_info_pool); | |
3820 | free_alloc_pool (rtx_group_info_pool); | |
3821 | free_alloc_pool (deferred_change_pool); | |
3822 | } | |
3823 | ||
3824 | ||
6fb5fa3c DB |
3825 | /* ------------------------------------------------------------------------- |
3826 | DSE | |
3827 | ------------------------------------------------------------------------- */ | |
3828 | ||
3829 | /* Callback for running pass_rtl_dse. */ | |
3830 | ||
3831 | static unsigned int | |
3832 | rest_of_handle_dse (void) | |
3833 | { | |
3834 | bool did_global = false; | |
3835 | ||
3836 | df_set_flags (DF_DEFER_INSN_RESCAN); | |
3837 | ||
02b47899 KZ |
3838 | /* Need the notes since we must track live hardregs in the forwards |
3839 | direction. */ | |
3840 | df_note_add_problem (); | |
3841 | df_analyze (); | |
3842 | ||
6fb5fa3c DB |
3843 | dse_step0 (); |
3844 | dse_step1 (); | |
3845 | dse_step2_init (); | |
3846 | if (dse_step2_nospill ()) | |
3847 | { | |
3848 | df_set_flags (DF_LR_RUN_DCE); | |
3849 | df_analyze (); | |
3850 | did_global = true; | |
3851 | if (dump_file) | |
3852 | fprintf (dump_file, "doing global processing\n"); | |
3853 | dse_step3 (false); | |
3854 | dse_step4 (); | |
3855 | dse_step5_nospill (); | |
3856 | } | |
3857 | ||
3858 | /* For the instance of dse that runs after reload, we make a special | |
3859 | pass to process the spills. These are special in that they are | |
3860 | totally transparent, i.e, there is no aliasing issues that need | |
3861 | to be considered. This means that the wild reads that kill | |
b8698a0f | 3862 | everything else do not apply here. */ |
6fb5fa3c DB |
3863 | if (clear_alias_sets && dse_step2_spill ()) |
3864 | { | |
3865 | if (!did_global) | |
3866 | { | |
3867 | df_set_flags (DF_LR_RUN_DCE); | |
3868 | df_analyze (); | |
3869 | } | |
3870 | did_global = true; | |
3871 | if (dump_file) | |
3872 | fprintf (dump_file, "doing global spill processing\n"); | |
3873 | dse_step3 (true); | |
3874 | dse_step4 (); | |
3875 | dse_step5_spill (); | |
3876 | } | |
8dd5516b JJ |
3877 | |
3878 | dse_step6 (); | |
3f9b14ff | 3879 | dse_step7 (); |
6fb5fa3c DB |
3880 | |
3881 | if (dump_file) | |
3882 | fprintf (dump_file, "dse: local deletions = %d, global deletions = %d, spill deletions = %d\n", | |
3883 | locally_deleted, globally_deleted, spill_deleted); | |
3884 | return 0; | |
3885 | } | |
3886 | ||
7d817ebc DE |
3887 | static bool |
3888 | gate_dse1 (void) | |
3889 | { | |
3890 | return optimize > 0 && flag_dse | |
3891 | && dbg_cnt (dse1); | |
3892 | } | |
3893 | ||
3894 | static bool | |
3895 | gate_dse2 (void) | |
3896 | { | |
3897 | return optimize > 0 && flag_dse | |
3898 | && dbg_cnt (dse2); | |
6fb5fa3c DB |
3899 | } |
3900 | ||
8ddbbcae | 3901 | struct rtl_opt_pass pass_rtl_dse1 = |
6fb5fa3c | 3902 | { |
8ddbbcae JH |
3903 | { |
3904 | RTL_PASS, | |
6fb5fa3c | 3905 | "dse1", /* name */ |
7d817ebc | 3906 | gate_dse1, /* gate */ |
6fb5fa3c DB |
3907 | rest_of_handle_dse, /* execute */ |
3908 | NULL, /* sub */ | |
3909 | NULL, /* next */ | |
3910 | 0, /* static_pass_number */ | |
3911 | TV_DSE1, /* tv_id */ | |
3912 | 0, /* properties_required */ | |
3913 | 0, /* properties_provided */ | |
3914 | 0, /* properties_destroyed */ | |
3915 | 0, /* todo_flags_start */ | |
a36b8a1e | 3916 | TODO_df_finish | TODO_verify_rtl_sharing | |
8ddbbcae JH |
3917 | TODO_ggc_collect /* todo_flags_finish */ |
3918 | } | |
6fb5fa3c DB |
3919 | }; |
3920 | ||
8ddbbcae | 3921 | struct rtl_opt_pass pass_rtl_dse2 = |
6fb5fa3c | 3922 | { |
8ddbbcae JH |
3923 | { |
3924 | RTL_PASS, | |
6fb5fa3c | 3925 | "dse2", /* name */ |
7d817ebc | 3926 | gate_dse2, /* gate */ |
6fb5fa3c DB |
3927 | rest_of_handle_dse, /* execute */ |
3928 | NULL, /* sub */ | |
3929 | NULL, /* next */ | |
3930 | 0, /* static_pass_number */ | |
3931 | TV_DSE2, /* tv_id */ | |
3932 | 0, /* properties_required */ | |
3933 | 0, /* properties_provided */ | |
3934 | 0, /* properties_destroyed */ | |
3935 | 0, /* todo_flags_start */ | |
a36b8a1e | 3936 | TODO_df_finish | TODO_verify_rtl_sharing | |
8ddbbcae JH |
3937 | TODO_ggc_collect /* todo_flags_finish */ |
3938 | } | |
6fb5fa3c | 3939 | }; |