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3072d30e | 1 | /* RTL dead store elimination. |
d353bf18 | 2 | Copyright (C) 2005-2015 Free Software Foundation, Inc. |
3072d30e | 3 | |
4 | Contributed by Richard Sandiford <rsandifor@codesourcery.com> | |
5 | and Kenneth Zadeck <zadeck@naturalbridge.com> | |
6 | ||
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it under | |
10 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 11 | Software Foundation; either version 3, or (at your option) any later |
3072d30e | 12 | version. |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
15 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
17 | for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
3072d30e | 22 | |
23 | #undef BASELINE | |
24 | ||
25 | #include "config.h" | |
26 | #include "system.h" | |
27 | #include "coretypes.h" | |
9ef16211 | 28 | #include "backend.h" |
7c29e30e | 29 | #include "target.h" |
30 | #include "rtl.h" | |
9ef16211 | 31 | #include "tree.h" |
32 | #include "gimple.h" | |
7c29e30e | 33 | #include "predict.h" |
9ef16211 | 34 | #include "df.h" |
7c29e30e | 35 | #include "tm_p.h" |
36 | #include "gimple-ssa.h" | |
37 | #include "expmed.h" | |
38 | #include "optabs.h" | |
39 | #include "regs.h" | |
40 | #include "emit-rtl.h" | |
41 | #include "recog.h" | |
b20a8bb4 | 42 | #include "alias.h" |
b20a8bb4 | 43 | #include "fold-const.h" |
9ed99284 | 44 | #include "stor-layout.h" |
3072d30e | 45 | #include "flags.h" |
94ea8568 | 46 | #include "cfgrtl.h" |
3072d30e | 47 | #include "cselib.h" |
3072d30e | 48 | #include "tree-pass.h" |
d53441c8 | 49 | #include "dojump.h" |
50 | #include "explow.h" | |
51 | #include "calls.h" | |
d53441c8 | 52 | #include "varasm.h" |
53 | #include "stmt.h" | |
3072d30e | 54 | #include "expr.h" |
3072d30e | 55 | #include "dbgcnt.h" |
1242bee6 | 56 | #include "params.h" |
bc61cadb | 57 | #include "internal-fn.h" |
ec1203cd | 58 | #include "rtl-iter.h" |
1f91a12d | 59 | #include "cfgcleanup.h" |
3072d30e | 60 | |
61 | /* This file contains three techniques for performing Dead Store | |
48e1416a | 62 | Elimination (dse). |
3072d30e | 63 | |
64 | * The first technique performs dse locally on any base address. It | |
65 | is based on the cselib which is a local value numbering technique. | |
66 | This technique is local to a basic block but deals with a fairly | |
67 | general addresses. | |
48e1416a | 68 | |
3072d30e | 69 | * The second technique performs dse globally but is restricted to |
70 | base addresses that are either constant or are relative to the | |
71 | frame_pointer. | |
72 | ||
73 | * The third technique, (which is only done after register allocation) | |
47ae02b7 | 74 | processes the spill slots. This differs from the second |
3072d30e | 75 | technique because it takes advantage of the fact that spilling is |
76 | completely free from the effects of aliasing. | |
77 | ||
78 | Logically, dse is a backwards dataflow problem. A store can be | |
79 | deleted if it if cannot be reached in the backward direction by any | |
80 | use of the value being stored. However, the local technique uses a | |
81 | forwards scan of the basic block because cselib requires that the | |
82 | block be processed in that order. | |
83 | ||
84 | The pass is logically broken into 7 steps: | |
85 | ||
86 | 0) Initialization. | |
87 | ||
88 | 1) The local algorithm, as well as scanning the insns for the two | |
89 | global algorithms. | |
90 | ||
91 | 2) Analysis to see if the global algs are necessary. In the case | |
92 | of stores base on a constant address, there must be at least two | |
93 | stores to that address, to make it possible to delete some of the | |
94 | stores. In the case of stores off of the frame or spill related | |
95 | stores, only one store to an address is necessary because those | |
96 | stores die at the end of the function. | |
97 | ||
48e1416a | 98 | 3) Set up the global dataflow equations based on processing the |
3072d30e | 99 | info parsed in the first step. |
100 | ||
101 | 4) Solve the dataflow equations. | |
102 | ||
103 | 5) Delete the insns that the global analysis has indicated are | |
104 | unnecessary. | |
105 | ||
9d75589a | 106 | 6) Delete insns that store the same value as preceding store |
aa140b76 | 107 | where the earlier store couldn't be eliminated. |
108 | ||
109 | 7) Cleanup. | |
3072d30e | 110 | |
111 | This step uses cselib and canon_rtx to build the largest expression | |
112 | possible for each address. This pass is a forwards pass through | |
113 | each basic block. From the point of view of the global technique, | |
114 | the first pass could examine a block in either direction. The | |
bef304b8 | 115 | forwards ordering is to accommodate cselib. |
3072d30e | 116 | |
2d0fd66d | 117 | We make a simplifying assumption: addresses fall into four broad |
3072d30e | 118 | categories: |
119 | ||
120 | 1) base has rtx_varies_p == false, offset is constant. | |
121 | 2) base has rtx_varies_p == false, offset variable. | |
122 | 3) base has rtx_varies_p == true, offset constant. | |
123 | 4) base has rtx_varies_p == true, offset variable. | |
124 | ||
125 | The local passes are able to process all 4 kinds of addresses. The | |
2d0fd66d | 126 | global pass only handles 1). |
3072d30e | 127 | |
128 | The global problem is formulated as follows: | |
129 | ||
130 | A store, S1, to address A, where A is not relative to the stack | |
131 | frame, can be eliminated if all paths from S1 to the end of the | |
2d0fd66d | 132 | function contain another store to A before a read to A. |
3072d30e | 133 | |
134 | If the address A is relative to the stack frame, a store S2 to A | |
2d0fd66d | 135 | can be eliminated if there are no paths from S2 that reach the |
3072d30e | 136 | end of the function that read A before another store to A. In |
2d0fd66d | 137 | this case S2 can be deleted if there are paths from S2 to the |
3072d30e | 138 | end of the function that have no reads or writes to A. This |
139 | second case allows stores to the stack frame to be deleted that | |
140 | would otherwise die when the function returns. This cannot be | |
141 | done if stores_off_frame_dead_at_return is not true. See the doc | |
142 | for that variable for when this variable is false. | |
143 | ||
144 | The global problem is formulated as a backwards set union | |
145 | dataflow problem where the stores are the gens and reads are the | |
146 | kills. Set union problems are rare and require some special | |
147 | handling given our representation of bitmaps. A straightforward | |
2d0fd66d | 148 | implementation requires a lot of bitmaps filled with 1s. |
3072d30e | 149 | These are expensive and cumbersome in our bitmap formulation so |
150 | care has been taken to avoid large vectors filled with 1s. See | |
151 | the comments in bb_info and in the dataflow confluence functions | |
48e1416a | 152 | for details. |
3072d30e | 153 | |
154 | There are two places for further enhancements to this algorithm: | |
48e1416a | 155 | |
3072d30e | 156 | 1) The original dse which was embedded in a pass called flow also |
157 | did local address forwarding. For example in | |
158 | ||
159 | A <- r100 | |
160 | ... <- A | |
161 | ||
162 | flow would replace the right hand side of the second insn with a | |
6dfdc153 | 163 | reference to r100. Most of the information is available to add this |
3072d30e | 164 | to this pass. It has not done it because it is a lot of work in |
165 | the case that either r100 is assigned to between the first and | |
166 | second insn and/or the second insn is a load of part of the value | |
167 | stored by the first insn. | |
168 | ||
169 | insn 5 in gcc.c-torture/compile/990203-1.c simple case. | |
170 | insn 15 in gcc.c-torture/execute/20001017-2.c simple case. | |
171 | insn 25 in gcc.c-torture/execute/20001026-1.c simple case. | |
172 | insn 44 in gcc.c-torture/execute/20010910-1.c simple case. | |
173 | ||
174 | 2) The cleaning up of spill code is quite profitable. It currently | |
175 | depends on reading tea leaves and chicken entrails left by reload. | |
176 | This pass depends on reload creating a singleton alias set for each | |
177 | spill slot and telling the next dse pass which of these alias sets | |
178 | are the singletons. Rather than analyze the addresses of the | |
179 | spills, dse's spill processing just does analysis of the loads and | |
180 | stores that use those alias sets. There are three cases where this | |
181 | falls short: | |
182 | ||
183 | a) Reload sometimes creates the slot for one mode of access, and | |
184 | then inserts loads and/or stores for a smaller mode. In this | |
185 | case, the current code just punts on the slot. The proper thing | |
186 | to do is to back out and use one bit vector position for each | |
187 | byte of the entity associated with the slot. This depends on | |
188 | KNOWING that reload always generates the accesses for each of the | |
189 | bytes in some canonical (read that easy to understand several | |
190 | passes after reload happens) way. | |
191 | ||
192 | b) Reload sometimes decides that spill slot it allocated was not | |
193 | large enough for the mode and goes back and allocates more slots | |
194 | with the same mode and alias set. The backout in this case is a | |
195 | little more graceful than (a). In this case the slot is unmarked | |
196 | as being a spill slot and if final address comes out to be based | |
48e1416a | 197 | off the frame pointer, the global algorithm handles this slot. |
3072d30e | 198 | |
199 | c) For any pass that may prespill, there is currently no | |
200 | mechanism to tell the dse pass that the slot being used has the | |
201 | special properties that reload uses. It may be that all that is | |
bef304b8 | 202 | required is to have those passes make the same calls that reload |
3072d30e | 203 | does, assuming that the alias sets can be manipulated in the same |
204 | way. */ | |
205 | ||
206 | /* There are limits to the size of constant offsets we model for the | |
207 | global problem. There are certainly test cases, that exceed this | |
208 | limit, however, it is unlikely that there are important programs | |
209 | that really have constant offsets this size. */ | |
210 | #define MAX_OFFSET (64 * 1024) | |
211 | ||
4fb07d00 | 212 | /* Obstack for the DSE dataflow bitmaps. We don't want to put these |
213 | on the default obstack because these bitmaps can grow quite large | |
214 | (~2GB for the small (!) test case of PR54146) and we'll hold on to | |
215 | all that memory until the end of the compiler run. | |
216 | As a bonus, delete_tree_live_info can destroy all the bitmaps by just | |
217 | releasing the whole obstack. */ | |
218 | static bitmap_obstack dse_bitmap_obstack; | |
219 | ||
220 | /* Obstack for other data. As for above: Kinda nice to be able to | |
221 | throw it all away at the end in one big sweep. */ | |
222 | static struct obstack dse_obstack; | |
223 | ||
224 | /* Scratch bitmap for cselib's cselib_expand_value_rtx. */ | |
3072d30e | 225 | static bitmap scratch = NULL; |
4fb07d00 | 226 | |
55c5ac9f | 227 | struct insn_info_type; |
3072d30e | 228 | |
229 | /* This structure holds information about a candidate store. */ | |
48e1416a | 230 | struct store_info |
3072d30e | 231 | { |
232 | ||
233 | /* False means this is a clobber. */ | |
234 | bool is_set; | |
235 | ||
aa140b76 | 236 | /* False if a single HOST_WIDE_INT bitmap is used for positions_needed. */ |
237 | bool is_large; | |
238 | ||
3072d30e | 239 | /* The id of the mem group of the base address. If rtx_varies_p is |
240 | true, this is -1. Otherwise, it is the index into the group | |
241 | table. */ | |
242 | int group_id; | |
48e1416a | 243 | |
3072d30e | 244 | /* This is the cselib value. */ |
245 | cselib_val *cse_base; | |
246 | ||
247 | /* This canonized mem. */ | |
248 | rtx mem; | |
249 | ||
82d2c88b | 250 | /* Canonized MEM address for use by canon_true_dependence. */ |
3072d30e | 251 | rtx mem_addr; |
252 | ||
253 | /* If this is non-zero, it is the alias set of a spill location. */ | |
32c2fdea | 254 | alias_set_type alias_set; |
3072d30e | 255 | |
256 | /* The offset of the first and byte before the last byte associated | |
257 | with the operation. */ | |
aa140b76 | 258 | HOST_WIDE_INT begin, end; |
259 | ||
260 | union | |
261 | { | |
262 | /* A bitmask as wide as the number of bytes in the word that | |
263 | contains a 1 if the byte may be needed. The store is unused if | |
264 | all of the bits are 0. This is used if IS_LARGE is false. */ | |
265 | unsigned HOST_WIDE_INT small_bitmask; | |
266 | ||
267 | struct | |
268 | { | |
269 | /* A bitmap with one bit per byte. Cleared bit means the position | |
270 | is needed. Used if IS_LARGE is false. */ | |
843bd2fa | 271 | bitmap bmap; |
3072d30e | 272 | |
aa140b76 | 273 | /* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is |
274 | equal to END - BEGIN, the whole store is unused. */ | |
275 | int count; | |
276 | } large; | |
277 | } positions_needed; | |
3072d30e | 278 | |
279 | /* The next store info for this insn. */ | |
280 | struct store_info *next; | |
281 | ||
282 | /* The right hand side of the store. This is used if there is a | |
283 | subsequent reload of the mems address somewhere later in the | |
284 | basic block. */ | |
aa140b76 | 285 | rtx rhs; |
286 | ||
287 | /* If rhs is or holds a constant, this contains that constant, | |
288 | otherwise NULL. */ | |
289 | rtx const_rhs; | |
290 | ||
291 | /* Set if this store stores the same constant value as REDUNDANT_REASON | |
292 | insn stored. These aren't eliminated early, because doing that | |
293 | might prevent the earlier larger store to be eliminated. */ | |
55c5ac9f | 294 | struct insn_info_type *redundant_reason; |
3072d30e | 295 | }; |
296 | ||
4e43e20a | 297 | /* Return a bitmask with the first N low bits set. */ |
298 | ||
299 | static unsigned HOST_WIDE_INT | |
300 | lowpart_bitmask (int n) | |
301 | { | |
302 | unsigned HOST_WIDE_INT mask = ~(unsigned HOST_WIDE_INT) 0; | |
303 | return mask >> (HOST_BITS_PER_WIDE_INT - n); | |
304 | } | |
305 | ||
1dc6c44d | 306 | static object_allocator<store_info> cse_store_info_pool ("cse_store_info_pool"); |
55c5ac9f | 307 | |
1dc6c44d | 308 | static object_allocator<store_info> rtx_store_info_pool ("rtx_store_info_pool"); |
3072d30e | 309 | |
310 | /* This structure holds information about a load. These are only | |
311 | built for rtx bases. */ | |
55c5ac9f | 312 | struct read_info_type |
3072d30e | 313 | { |
314 | /* The id of the mem group of the base address. */ | |
315 | int group_id; | |
316 | ||
317 | /* If this is non-zero, it is the alias set of a spill location. */ | |
32c2fdea | 318 | alias_set_type alias_set; |
3072d30e | 319 | |
320 | /* The offset of the first and byte after the last byte associated | |
321 | with the operation. If begin == end == 0, the read did not have | |
322 | a constant offset. */ | |
323 | int begin, end; | |
324 | ||
325 | /* The mem being read. */ | |
326 | rtx mem; | |
327 | ||
328 | /* The next read_info for this insn. */ | |
55c5ac9f | 329 | struct read_info_type *next; |
3072d30e | 330 | }; |
55c5ac9f | 331 | typedef struct read_info_type *read_info_t; |
3072d30e | 332 | |
1dc6c44d | 333 | static object_allocator<read_info_type> read_info_type_pool ("read_info_pool"); |
3072d30e | 334 | |
335 | /* One of these records is created for each insn. */ | |
336 | ||
55c5ac9f | 337 | struct insn_info_type |
3072d30e | 338 | { |
339 | /* Set true if the insn contains a store but the insn itself cannot | |
340 | be deleted. This is set if the insn is a parallel and there is | |
341 | more than one non dead output or if the insn is in some way | |
342 | volatile. */ | |
343 | bool cannot_delete; | |
344 | ||
345 | /* This field is only used by the global algorithm. It is set true | |
346 | if the insn contains any read of mem except for a (1). This is | |
347 | also set if the insn is a call or has a clobber mem. If the insn | |
348 | contains a wild read, the use_rec will be null. */ | |
349 | bool wild_read; | |
350 | ||
b4a708fb | 351 | /* This is true only for CALL instructions which could potentially read |
352 | any non-frame memory location. This field is used by the global | |
353 | algorithm. */ | |
354 | bool non_frame_wild_read; | |
355 | ||
17e1318c | 356 | /* This field is only used for the processing of const functions. |
357 | These functions cannot read memory, but they can read the stack | |
16bf64db | 358 | because that is where they may get their parms. We need to be |
359 | this conservative because, like the store motion pass, we don't | |
360 | consider CALL_INSN_FUNCTION_USAGE when processing call insns. | |
361 | Moreover, we need to distinguish two cases: | |
362 | 1. Before reload (register elimination), the stores related to | |
363 | outgoing arguments are stack pointer based and thus deemed | |
364 | of non-constant base in this pass. This requires special | |
365 | handling but also means that the frame pointer based stores | |
366 | need not be killed upon encountering a const function call. | |
367 | 2. After reload, the stores related to outgoing arguments can be | |
368 | either stack pointer or hard frame pointer based. This means | |
369 | that we have no other choice than also killing all the frame | |
370 | pointer based stores upon encountering a const function call. | |
17853422 | 371 | This field is set after reload for const function calls and before |
372 | reload for const tail function calls on targets where arg pointer | |
373 | is the frame pointer. Having this set is less severe than a wild | |
374 | read, it just means that all the frame related stores are killed | |
375 | rather than all the stores. */ | |
16bf64db | 376 | bool frame_read; |
377 | ||
378 | /* This field is only used for the processing of const functions. | |
379 | It is set if the insn may contain a stack pointer based store. */ | |
17e1318c | 380 | bool stack_pointer_based; |
3072d30e | 381 | |
382 | /* This is true if any of the sets within the store contains a | |
383 | cselib base. Such stores can only be deleted by the local | |
384 | algorithm. */ | |
385 | bool contains_cselib_groups; | |
386 | ||
387 | /* The insn. */ | |
ebabb7a3 | 388 | rtx_insn *insn; |
3072d30e | 389 | |
390 | /* The list of mem sets or mem clobbers that are contained in this | |
391 | insn. If the insn is deletable, it contains only one mem set. | |
392 | But it could also contain clobbers. Insns that contain more than | |
393 | one mem set are not deletable, but each of those mems are here in | |
6dfdc153 | 394 | order to provide info to delete other insns. */ |
c2eab334 | 395 | store_info *store_rec; |
3072d30e | 396 | |
397 | /* The linked list of mem uses in this insn. Only the reads from | |
398 | rtx bases are listed here. The reads to cselib bases are | |
399 | completely processed during the first scan and so are never | |
400 | created. */ | |
401 | read_info_t read_rec; | |
402 | ||
5a9ecd4a | 403 | /* The live fixed registers. We assume only fixed registers can |
404 | cause trouble by being clobbered from an expanded pattern; | |
405 | storing only the live fixed registers (rather than all registers) | |
406 | means less memory needs to be allocated / copied for the individual | |
407 | stores. */ | |
408 | regset fixed_regs_live; | |
409 | ||
3072d30e | 410 | /* The prev insn in the basic block. */ |
55c5ac9f | 411 | struct insn_info_type * prev_insn; |
3072d30e | 412 | |
413 | /* The linked list of insns that are in consideration for removal in | |
9d75589a | 414 | the forwards pass through the basic block. This pointer may be |
3072d30e | 415 | trash as it is not cleared when a wild read occurs. The only |
f0b5f617 | 416 | time it is guaranteed to be correct is when the traversal starts |
3072d30e | 417 | at active_local_stores. */ |
55c5ac9f | 418 | struct insn_info_type * next_local_store; |
3072d30e | 419 | }; |
55c5ac9f | 420 | typedef struct insn_info_type *insn_info_t; |
3072d30e | 421 | |
1dc6c44d | 422 | static object_allocator<insn_info_type> insn_info_type_pool ("insn_info_pool"); |
3072d30e | 423 | |
424 | /* The linked list of stores that are under consideration in this | |
48e1416a | 425 | basic block. */ |
3072d30e | 426 | static insn_info_t active_local_stores; |
1242bee6 | 427 | static int active_local_stores_len; |
3072d30e | 428 | |
55c5ac9f | 429 | struct dse_bb_info_type |
3072d30e | 430 | { |
3072d30e | 431 | /* Pointer to the insn info for the last insn in the block. These |
432 | are linked so this is how all of the insns are reached. During | |
433 | scanning this is the current insn being scanned. */ | |
434 | insn_info_t last_insn; | |
435 | ||
436 | /* The info for the global dataflow problem. */ | |
437 | ||
438 | ||
439 | /* This is set if the transfer function should and in the wild_read | |
440 | bitmap before applying the kill and gen sets. That vector knocks | |
441 | out most of the bits in the bitmap and thus speeds up the | |
442 | operations. */ | |
443 | bool apply_wild_read; | |
444 | ||
a1b0a968 | 445 | /* The following 4 bitvectors hold information about which positions |
446 | of which stores are live or dead. They are indexed by | |
447 | get_bitmap_index. */ | |
448 | ||
3072d30e | 449 | /* The set of store positions that exist in this block before a wild read. */ |
450 | bitmap gen; | |
48e1416a | 451 | |
3072d30e | 452 | /* The set of load positions that exist in this block above the |
453 | same position of a store. */ | |
454 | bitmap kill; | |
455 | ||
456 | /* The set of stores that reach the top of the block without being | |
457 | killed by a read. | |
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 set, this is too | |
462 | expensive. So initially, the in set will only be created for the | |
463 | exit block and any block that contains a wild read. */ | |
464 | bitmap in; | |
465 | ||
466 | /* The set of stores that reach the bottom of the block from it's | |
467 | successors. | |
468 | ||
469 | Do not represent the in if it is all ones. Note that this is | |
470 | what the bitvector should logically be initialized to for a set | |
471 | intersection problem. However, like the kill and in set, this is | |
472 | too expensive. So what is done is that the confluence operator | |
473 | just initializes the vector from one of the out sets of the | |
474 | successors of the block. */ | |
475 | bitmap out; | |
a1b0a968 | 476 | |
477 | /* The following bitvector is indexed by the reg number. It | |
478 | contains the set of regs that are live at the current instruction | |
479 | being processed. While it contains info for all of the | |
5a9ecd4a | 480 | registers, only the hard registers are actually examined. It is used |
481 | to assure that shift and/or add sequences that are inserted do not | |
9d75589a | 482 | accidentally clobber live hard regs. */ |
a1b0a968 | 483 | bitmap regs_live; |
3072d30e | 484 | }; |
485 | ||
55c5ac9f | 486 | typedef struct dse_bb_info_type *bb_info_t; |
e16712b1 | 487 | |
488 | static object_allocator<dse_bb_info_type> dse_bb_info_type_pool | |
1dc6c44d | 489 | ("bb_info_pool"); |
3072d30e | 490 | |
491 | /* Table to hold all bb_infos. */ | |
492 | static bb_info_t *bb_table; | |
493 | ||
494 | /* There is a group_info for each rtx base that is used to reference | |
495 | memory. There are also not many of the rtx bases because they are | |
496 | very limited in scope. */ | |
497 | ||
48e1416a | 498 | struct group_info |
3072d30e | 499 | { |
500 | /* The actual base of the address. */ | |
501 | rtx rtx_base; | |
502 | ||
503 | /* The sequential id of the base. This allows us to have a | |
504 | canonical ordering of these that is not based on addresses. */ | |
505 | int id; | |
506 | ||
0ac758f7 | 507 | /* True if there are any positions that are to be processed |
508 | globally. */ | |
509 | bool process_globally; | |
510 | ||
511 | /* True if the base of this group is either the frame_pointer or | |
512 | hard_frame_pointer. */ | |
513 | bool frame_related; | |
514 | ||
ec410bf1 | 515 | /* A mem wrapped around the base pointer for the group in order to do |
516 | read dependency. It must be given BLKmode in order to encompass all | |
517 | the possible offsets from the base. */ | |
3072d30e | 518 | rtx base_mem; |
48e1416a | 519 | |
82d2c88b | 520 | /* Canonized version of base_mem's address. */ |
521 | rtx canon_base_addr; | |
3072d30e | 522 | |
523 | /* These two sets of two bitmaps are used to keep track of how many | |
6dfdc153 | 524 | stores are actually referencing that position from this base. We |
3072d30e | 525 | only do this for rtx bases as this will be used to assign |
6dfdc153 | 526 | positions in the bitmaps for the global problem. Bit N is set in |
3072d30e | 527 | store1 on the first store for offset N. Bit N is set in store2 |
528 | for the second store to offset N. This is all we need since we | |
529 | only care about offsets that have two or more stores for them. | |
530 | ||
531 | The "_n" suffix is for offsets less than 0 and the "_p" suffix is | |
532 | for 0 and greater offsets. | |
533 | ||
534 | There is one special case here, for stores into the stack frame, | |
535 | we will or store1 into store2 before deciding which stores look | |
536 | at globally. This is because stores to the stack frame that have | |
537 | no other reads before the end of the function can also be | |
538 | deleted. */ | |
539 | bitmap store1_n, store1_p, store2_n, store2_p; | |
540 | ||
b4a708fb | 541 | /* These bitmaps keep track of offsets in this group escape this function. |
542 | An offset escapes if it corresponds to a named variable whose | |
543 | addressable flag is set. */ | |
544 | bitmap escaped_n, escaped_p; | |
545 | ||
6dfdc153 | 546 | /* The positions in this bitmap have the same assignments as the in, |
3072d30e | 547 | out, gen and kill bitmaps. This bitmap is all zeros except for |
6dfdc153 | 548 | the positions that are occupied by stores for this group. */ |
3072d30e | 549 | bitmap group_kill; |
550 | ||
3072d30e | 551 | /* The offset_map is used to map the offsets from this base into |
6dfdc153 | 552 | positions in the global bitmaps. It is only created after all of |
3072d30e | 553 | the all of stores have been scanned and we know which ones we |
554 | care about. */ | |
48e1416a | 555 | int *offset_map_n, *offset_map_p; |
556 | int offset_map_size_n, offset_map_size_p; | |
3072d30e | 557 | }; |
55c5ac9f | 558 | |
1dc6c44d | 559 | static object_allocator<group_info> group_info_pool ("rtx_group_info_pool"); |
3072d30e | 560 | |
3072d30e | 561 | /* Index into the rtx_group_vec. */ |
562 | static int rtx_group_next_id; | |
563 | ||
3072d30e | 564 | |
c2eab334 | 565 | static vec<group_info *> rtx_group_vec; |
3072d30e | 566 | |
567 | ||
568 | /* This structure holds the set of changes that are being deferred | |
569 | when removing read operation. See replace_read. */ | |
48e1416a | 570 | struct deferred_change |
3072d30e | 571 | { |
572 | ||
573 | /* The mem that is being replaced. */ | |
574 | rtx *loc; | |
575 | ||
576 | /* The reg it is being replaced with. */ | |
577 | rtx reg; | |
578 | ||
579 | struct deferred_change *next; | |
580 | }; | |
581 | ||
e16712b1 | 582 | static object_allocator<deferred_change> deferred_change_pool |
1dc6c44d | 583 | ("deferred_change_pool"); |
3072d30e | 584 | |
c2eab334 | 585 | static deferred_change *deferred_change_list = NULL; |
3072d30e | 586 | |
3072d30e | 587 | /* The group that holds all of the clear_alias_sets. */ |
c2eab334 | 588 | static group_info *clear_alias_group; |
3072d30e | 589 | |
590 | /* The modes of the clear_alias_sets. */ | |
591 | static htab_t clear_alias_mode_table; | |
592 | ||
593 | /* Hash table element to look up the mode for an alias set. */ | |
594 | struct clear_alias_mode_holder | |
595 | { | |
32c2fdea | 596 | alias_set_type alias_set; |
3754d046 | 597 | machine_mode mode; |
3072d30e | 598 | }; |
599 | ||
18d50ae6 | 600 | /* This is true except if cfun->stdarg -- i.e. we cannot do |
ff3ae375 | 601 | this for vararg functions because they play games with the frame. */ |
3072d30e | 602 | static bool stores_off_frame_dead_at_return; |
603 | ||
604 | /* Counter for stats. */ | |
48e1416a | 605 | static int globally_deleted; |
606 | static int locally_deleted; | |
607 | static int spill_deleted; | |
608 | ||
3072d30e | 609 | static bitmap all_blocks; |
610 | ||
b4a708fb | 611 | /* Locations that are killed by calls in the global phase. */ |
612 | static bitmap kill_on_calls; | |
613 | ||
3072d30e | 614 | /* The number of bits used in the global bitmaps. */ |
615 | static unsigned int current_position; | |
3072d30e | 616 | \f |
617 | /*---------------------------------------------------------------------------- | |
618 | Zeroth step. | |
619 | ||
48e1416a | 620 | Initialization. |
3072d30e | 621 | ----------------------------------------------------------------------------*/ |
622 | ||
3072d30e | 623 | |
624 | /* Find the entry associated with ALIAS_SET. */ | |
625 | ||
626 | static struct clear_alias_mode_holder * | |
32c2fdea | 627 | clear_alias_set_lookup (alias_set_type alias_set) |
3072d30e | 628 | { |
629 | struct clear_alias_mode_holder tmp_holder; | |
630 | void **slot; | |
48e1416a | 631 | |
3072d30e | 632 | tmp_holder.alias_set = alias_set; |
633 | slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, NO_INSERT); | |
634 | gcc_assert (*slot); | |
48e1416a | 635 | |
364c0c59 | 636 | return (struct clear_alias_mode_holder *) *slot; |
3072d30e | 637 | } |
638 | ||
639 | ||
640 | /* Hashtable callbacks for maintaining the "bases" field of | |
641 | store_group_info, given that the addresses are function invariants. */ | |
642 | ||
770ff93b | 643 | struct invariant_group_base_hasher : nofree_ptr_hash <group_info> |
d1455aa3 | 644 | { |
9969c043 | 645 | static inline hashval_t hash (const group_info *); |
646 | static inline bool equal (const group_info *, const group_info *); | |
d1455aa3 | 647 | }; |
648 | ||
649 | inline bool | |
9969c043 | 650 | invariant_group_base_hasher::equal (const group_info *gi1, |
651 | const group_info *gi2) | |
3072d30e | 652 | { |
3072d30e | 653 | return rtx_equal_p (gi1->rtx_base, gi2->rtx_base); |
654 | } | |
655 | ||
d1455aa3 | 656 | inline hashval_t |
9969c043 | 657 | invariant_group_base_hasher::hash (const group_info *gi) |
3072d30e | 658 | { |
3072d30e | 659 | int do_not_record; |
660 | return hash_rtx (gi->rtx_base, Pmode, &do_not_record, NULL, false); | |
661 | } | |
662 | ||
d1455aa3 | 663 | /* Tables of group_info structures, hashed by base value. */ |
c1f445d2 | 664 | static hash_table<invariant_group_base_hasher> *rtx_group_table; |
d1455aa3 | 665 | |
3072d30e | 666 | |
667 | /* Get the GROUP for BASE. Add a new group if it is not there. */ | |
668 | ||
c2eab334 | 669 | static group_info * |
3072d30e | 670 | get_group_info (rtx base) |
671 | { | |
48e1416a | 672 | struct group_info tmp_gi; |
c2eab334 | 673 | group_info *gi; |
d1455aa3 | 674 | group_info **slot; |
3072d30e | 675 | |
676 | if (base) | |
677 | { | |
678 | /* Find the store_base_info structure for BASE, creating a new one | |
679 | if necessary. */ | |
680 | tmp_gi.rtx_base = base; | |
c1f445d2 | 681 | slot = rtx_group_table->find_slot (&tmp_gi, INSERT); |
c2eab334 | 682 | gi = *slot; |
3072d30e | 683 | } |
684 | else | |
685 | { | |
686 | if (!clear_alias_group) | |
687 | { | |
e16712b1 | 688 | clear_alias_group = gi = group_info_pool.allocate (); |
3072d30e | 689 | memset (gi, 0, sizeof (struct group_info)); |
690 | gi->id = rtx_group_next_id++; | |
4fb07d00 | 691 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
692 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
693 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
694 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
695 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
696 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
697 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
3072d30e | 698 | gi->process_globally = false; |
699 | gi->offset_map_size_n = 0; | |
700 | gi->offset_map_size_p = 0; | |
701 | gi->offset_map_n = NULL; | |
702 | gi->offset_map_p = NULL; | |
f1f41a6c | 703 | rtx_group_vec.safe_push (gi); |
3072d30e | 704 | } |
705 | return clear_alias_group; | |
706 | } | |
707 | ||
708 | if (gi == NULL) | |
709 | { | |
e16712b1 | 710 | *slot = gi = group_info_pool.allocate (); |
3072d30e | 711 | gi->rtx_base = base; |
712 | gi->id = rtx_group_next_id++; | |
ec410bf1 | 713 | gi->base_mem = gen_rtx_MEM (BLKmode, base); |
82d2c88b | 714 | gi->canon_base_addr = canon_rtx (base); |
4fb07d00 | 715 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
716 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
717 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
718 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
719 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
720 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
721 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
3072d30e | 722 | gi->process_globally = false; |
48e1416a | 723 | gi->frame_related = |
3072d30e | 724 | (base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx); |
725 | gi->offset_map_size_n = 0; | |
726 | gi->offset_map_size_p = 0; | |
727 | gi->offset_map_n = NULL; | |
728 | gi->offset_map_p = NULL; | |
f1f41a6c | 729 | rtx_group_vec.safe_push (gi); |
3072d30e | 730 | } |
731 | ||
732 | return gi; | |
733 | } | |
734 | ||
735 | ||
736 | /* Initialization of data structures. */ | |
737 | ||
738 | static void | |
739 | dse_step0 (void) | |
740 | { | |
741 | locally_deleted = 0; | |
742 | globally_deleted = 0; | |
743 | spill_deleted = 0; | |
744 | ||
4fb07d00 | 745 | bitmap_obstack_initialize (&dse_bitmap_obstack); |
746 | gcc_obstack_init (&dse_obstack); | |
747 | ||
748 | scratch = BITMAP_ALLOC (®_obstack); | |
749 | kill_on_calls = BITMAP_ALLOC (&dse_bitmap_obstack); | |
3072d30e | 750 | |
3072d30e | 751 | |
c1f445d2 | 752 | rtx_group_table = new hash_table<invariant_group_base_hasher> (11); |
3072d30e | 753 | |
fe672ac0 | 754 | bb_table = XNEWVEC (bb_info_t, last_basic_block_for_fn (cfun)); |
3072d30e | 755 | rtx_group_next_id = 0; |
756 | ||
18d50ae6 | 757 | stores_off_frame_dead_at_return = !cfun->stdarg; |
3072d30e | 758 | |
759 | init_alias_analysis (); | |
48e1416a | 760 | |
e85eaec5 | 761 | clear_alias_group = NULL; |
3072d30e | 762 | } |
763 | ||
764 | ||
765 | \f | |
766 | /*---------------------------------------------------------------------------- | |
767 | First step. | |
768 | ||
769 | Scan all of the insns. Any random ordering of the blocks is fine. | |
bef304b8 | 770 | Each block is scanned in forward order to accommodate cselib which |
3072d30e | 771 | is used to remove stores with non-constant bases. |
772 | ----------------------------------------------------------------------------*/ | |
773 | ||
774 | /* Delete all of the store_info recs from INSN_INFO. */ | |
775 | ||
48e1416a | 776 | static void |
3072d30e | 777 | free_store_info (insn_info_t insn_info) |
778 | { | |
c2eab334 | 779 | store_info *cur = insn_info->store_rec; |
780 | while (cur) | |
3072d30e | 781 | { |
c2eab334 | 782 | store_info *next = cur->next; |
783 | if (cur->is_large) | |
784 | BITMAP_FREE (cur->positions_needed.large.bmap); | |
785 | if (cur->cse_base) | |
786 | cse_store_info_pool.remove (cur); | |
3072d30e | 787 | else |
c2eab334 | 788 | rtx_store_info_pool.remove (cur); |
789 | cur = next; | |
3072d30e | 790 | } |
791 | ||
792 | insn_info->cannot_delete = true; | |
793 | insn_info->contains_cselib_groups = false; | |
794 | insn_info->store_rec = NULL; | |
795 | } | |
796 | ||
6dc50383 | 797 | struct note_add_store_info |
5a9ecd4a | 798 | { |
4cd001d5 | 799 | rtx_insn *first, *current; |
5a9ecd4a | 800 | regset fixed_regs_live; |
801 | bool failure; | |
6dc50383 | 802 | }; |
5a9ecd4a | 803 | |
804 | /* Callback for emit_inc_dec_insn_before via note_stores. | |
805 | Check if a register is clobbered which is live afterwards. */ | |
806 | ||
807 | static void | |
808 | note_add_store (rtx loc, const_rtx expr ATTRIBUTE_UNUSED, void *data) | |
809 | { | |
4cd001d5 | 810 | rtx_insn *insn; |
5a9ecd4a | 811 | note_add_store_info *info = (note_add_store_info *) data; |
5a9ecd4a | 812 | |
813 | if (!REG_P (loc)) | |
814 | return; | |
815 | ||
816 | /* If this register is referenced by the current or an earlier insn, | |
817 | that's OK. E.g. this applies to the register that is being incremented | |
818 | with this addition. */ | |
819 | for (insn = info->first; | |
820 | insn != NEXT_INSN (info->current); | |
821 | insn = NEXT_INSN (insn)) | |
822 | if (reg_referenced_p (loc, PATTERN (insn))) | |
823 | return; | |
824 | ||
825 | /* If we come here, we have a clobber of a register that's only OK | |
826 | if that register is not live. If we don't have liveness information | |
827 | available, fail now. */ | |
828 | if (!info->fixed_regs_live) | |
829 | { | |
6a298741 | 830 | info->failure = true; |
5a9ecd4a | 831 | return; |
832 | } | |
833 | /* Now check if this is a live fixed register. */ | |
6a298741 | 834 | unsigned int end_regno = END_REGNO (loc); |
835 | for (unsigned int regno = REGNO (loc); regno < end_regno; ++regno) | |
836 | if (REGNO_REG_SET_P (info->fixed_regs_live, regno)) | |
837 | info->failure = true; | |
5a9ecd4a | 838 | } |
839 | ||
1f864115 | 840 | /* Callback for for_each_inc_dec that emits an INSN that sets DEST to |
841 | SRC + SRCOFF before insn ARG. */ | |
3072d30e | 842 | |
843 | static int | |
1f864115 | 844 | emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED, |
845 | rtx op ATTRIBUTE_UNUSED, | |
846 | rtx dest, rtx src, rtx srcoff, void *arg) | |
3072d30e | 847 | { |
5a9ecd4a | 848 | insn_info_t insn_info = (insn_info_t) arg; |
4cd001d5 | 849 | rtx_insn *insn = insn_info->insn, *new_insn, *cur; |
5a9ecd4a | 850 | note_add_store_info info; |
48e1416a | 851 | |
1f864115 | 852 | /* We can reuse all operands without copying, because we are about |
853 | to delete the insn that contained it. */ | |
5a9ecd4a | 854 | if (srcoff) |
a280a5da | 855 | { |
856 | start_sequence (); | |
857 | emit_insn (gen_add3_insn (dest, src, srcoff)); | |
858 | new_insn = get_insns (); | |
859 | end_sequence (); | |
860 | } | |
5a9ecd4a | 861 | else |
f9a00e9e | 862 | new_insn = gen_move_insn (dest, src); |
5a9ecd4a | 863 | info.first = new_insn; |
864 | info.fixed_regs_live = insn_info->fixed_regs_live; | |
865 | info.failure = false; | |
866 | for (cur = new_insn; cur; cur = NEXT_INSN (cur)) | |
867 | { | |
868 | info.current = cur; | |
869 | note_stores (PATTERN (cur), note_add_store, &info); | |
870 | } | |
3072d30e | 871 | |
5a9ecd4a | 872 | /* If a failure was flagged above, return 1 so that for_each_inc_dec will |
873 | return it immediately, communicating the failure to its caller. */ | |
874 | if (info.failure) | |
875 | return 1; | |
876 | ||
877 | emit_insn_before (new_insn, insn); | |
3072d30e | 878 | |
623ad592 | 879 | return 0; |
3072d30e | 880 | } |
881 | ||
5a9ecd4a | 882 | /* Before we delete INSN_INFO->INSN, make sure that the auto inc/dec, if it |
883 | is there, is split into a separate insn. | |
884 | Return true on success (or if there was nothing to do), false on failure. */ | |
3072d30e | 885 | |
5a9ecd4a | 886 | static bool |
887 | check_for_inc_dec_1 (insn_info_t insn_info) | |
3072d30e | 888 | { |
ebabb7a3 | 889 | rtx_insn *insn = insn_info->insn; |
3072d30e | 890 | rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
891 | if (note) | |
623ad592 | 892 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
893 | insn_info) == 0; | |
5a9ecd4a | 894 | return true; |
3072d30e | 895 | } |
896 | ||
897 | ||
5a9ecd4a | 898 | /* Entry point for postreload. If you work on reload_cse, or you need this |
899 | anywhere else, consider if you can provide register liveness information | |
900 | and add a parameter to this function so that it can be passed down in | |
901 | insn_info.fixed_regs_live. */ | |
902 | bool | |
ebabb7a3 | 903 | check_for_inc_dec (rtx_insn *insn) |
5a9ecd4a | 904 | { |
55c5ac9f | 905 | insn_info_type insn_info; |
5a9ecd4a | 906 | rtx note; |
907 | ||
908 | insn_info.insn = insn; | |
909 | insn_info.fixed_regs_live = NULL; | |
910 | note = find_reg_note (insn, REG_INC, NULL_RTX); | |
911 | if (note) | |
623ad592 | 912 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
913 | &insn_info) == 0; | |
5a9ecd4a | 914 | return true; |
915 | } | |
916 | ||
48e1416a | 917 | /* Delete the insn and free all of the fields inside INSN_INFO. */ |
3072d30e | 918 | |
919 | static void | |
920 | delete_dead_store_insn (insn_info_t insn_info) | |
921 | { | |
922 | read_info_t read_info; | |
923 | ||
924 | if (!dbg_cnt (dse)) | |
925 | return; | |
926 | ||
5a9ecd4a | 927 | if (!check_for_inc_dec_1 (insn_info)) |
928 | return; | |
1ca59310 | 929 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 930 | { |
48e1416a | 931 | fprintf (dump_file, "Locally deleting insn %d ", |
3072d30e | 932 | INSN_UID (insn_info->insn)); |
933 | if (insn_info->store_rec->alias_set) | |
48e1416a | 934 | fprintf (dump_file, "alias set %d\n", |
32c2fdea | 935 | (int) insn_info->store_rec->alias_set); |
3072d30e | 936 | else |
937 | fprintf (dump_file, "\n"); | |
938 | } | |
939 | ||
940 | free_store_info (insn_info); | |
941 | read_info = insn_info->read_rec; | |
48e1416a | 942 | |
3072d30e | 943 | while (read_info) |
944 | { | |
945 | read_info_t next = read_info->next; | |
e16712b1 | 946 | read_info_type_pool.remove (read_info); |
3072d30e | 947 | read_info = next; |
948 | } | |
949 | insn_info->read_rec = NULL; | |
950 | ||
951 | delete_insn (insn_info->insn); | |
952 | locally_deleted++; | |
953 | insn_info->insn = NULL; | |
954 | ||
955 | insn_info->wild_read = false; | |
956 | } | |
957 | ||
f7b5f694 | 958 | /* Return whether DECL, a local variable, can possibly escape the current |
959 | function scope. */ | |
960 | ||
961 | static bool | |
962 | local_variable_can_escape (tree decl) | |
963 | { | |
964 | if (TREE_ADDRESSABLE (decl)) | |
965 | return true; | |
966 | ||
967 | /* If this is a partitioned variable, we need to consider all the variables | |
968 | in the partition. This is necessary because a store into one of them can | |
969 | be replaced with a store into another and this may not change the outcome | |
970 | of the escape analysis. */ | |
971 | if (cfun->gimple_df->decls_to_pointers != NULL) | |
972 | { | |
5f8841a5 | 973 | tree *namep = cfun->gimple_df->decls_to_pointers->get (decl); |
f7b5f694 | 974 | if (namep) |
5f8841a5 | 975 | return TREE_ADDRESSABLE (*namep); |
f7b5f694 | 976 | } |
977 | ||
978 | return false; | |
979 | } | |
980 | ||
981 | /* Return whether EXPR can possibly escape the current function scope. */ | |
982 | ||
b4a708fb | 983 | static bool |
984 | can_escape (tree expr) | |
985 | { | |
986 | tree base; | |
987 | if (!expr) | |
988 | return true; | |
989 | base = get_base_address (expr); | |
990 | if (DECL_P (base) | |
f7b5f694 | 991 | && !may_be_aliased (base) |
992 | && !(TREE_CODE (base) == VAR_DECL | |
993 | && !DECL_EXTERNAL (base) | |
994 | && !TREE_STATIC (base) | |
995 | && local_variable_can_escape (base))) | |
b4a708fb | 996 | return false; |
997 | return true; | |
998 | } | |
3072d30e | 999 | |
1000 | /* Set the store* bitmaps offset_map_size* fields in GROUP based on | |
1001 | OFFSET and WIDTH. */ | |
1002 | ||
1003 | static void | |
c2eab334 | 1004 | set_usage_bits (group_info *group, HOST_WIDE_INT offset, HOST_WIDE_INT width, |
b4a708fb | 1005 | tree expr) |
3072d30e | 1006 | { |
1007 | HOST_WIDE_INT i; | |
b4a708fb | 1008 | bool expr_escapes = can_escape (expr); |
aa140b76 | 1009 | if (offset > -MAX_OFFSET && offset + width < MAX_OFFSET) |
3072d30e | 1010 | for (i=offset; i<offset+width; i++) |
1011 | { | |
1012 | bitmap store1; | |
1013 | bitmap store2; | |
b4a708fb | 1014 | bitmap escaped; |
3072d30e | 1015 | int ai; |
1016 | if (i < 0) | |
1017 | { | |
1018 | store1 = group->store1_n; | |
1019 | store2 = group->store2_n; | |
b4a708fb | 1020 | escaped = group->escaped_n; |
3072d30e | 1021 | ai = -i; |
1022 | } | |
1023 | else | |
1024 | { | |
1025 | store1 = group->store1_p; | |
1026 | store2 = group->store2_p; | |
b4a708fb | 1027 | escaped = group->escaped_p; |
3072d30e | 1028 | ai = i; |
1029 | } | |
48e1416a | 1030 | |
6ef9bbe0 | 1031 | if (!bitmap_set_bit (store1, ai)) |
3072d30e | 1032 | bitmap_set_bit (store2, ai); |
48e1416a | 1033 | else |
3072d30e | 1034 | { |
3072d30e | 1035 | if (i < 0) |
1036 | { | |
1037 | if (group->offset_map_size_n < ai) | |
1038 | group->offset_map_size_n = ai; | |
1039 | } | |
1040 | else | |
1041 | { | |
1042 | if (group->offset_map_size_p < ai) | |
1043 | group->offset_map_size_p = ai; | |
1044 | } | |
1045 | } | |
b4a708fb | 1046 | if (expr_escapes) |
1047 | bitmap_set_bit (escaped, ai); | |
3072d30e | 1048 | } |
1049 | } | |
1050 | ||
b4a708fb | 1051 | static void |
1052 | reset_active_stores (void) | |
1053 | { | |
1054 | active_local_stores = NULL; | |
1055 | active_local_stores_len = 0; | |
1056 | } | |
3072d30e | 1057 | |
b4a708fb | 1058 | /* Free all READ_REC of the LAST_INSN of BB_INFO. */ |
3072d30e | 1059 | |
1060 | static void | |
b4a708fb | 1061 | free_read_records (bb_info_t bb_info) |
3072d30e | 1062 | { |
1063 | insn_info_t insn_info = bb_info->last_insn; | |
1064 | read_info_t *ptr = &insn_info->read_rec; | |
3072d30e | 1065 | while (*ptr) |
1066 | { | |
1067 | read_info_t next = (*ptr)->next; | |
32c2fdea | 1068 | if ((*ptr)->alias_set == 0) |
3072d30e | 1069 | { |
e16712b1 | 1070 | read_info_type_pool.remove (*ptr); |
3072d30e | 1071 | *ptr = next; |
b4a708fb | 1072 | } |
48e1416a | 1073 | else |
b4a708fb | 1074 | ptr = &(*ptr)->next; |
3072d30e | 1075 | } |
b4a708fb | 1076 | } |
1077 | ||
1078 | /* Set the BB_INFO so that the last insn is marked as a wild read. */ | |
1079 | ||
1080 | static void | |
1081 | add_wild_read (bb_info_t bb_info) | |
1082 | { | |
1083 | insn_info_t insn_info = bb_info->last_insn; | |
3072d30e | 1084 | insn_info->wild_read = true; |
b4a708fb | 1085 | free_read_records (bb_info); |
1086 | reset_active_stores (); | |
3072d30e | 1087 | } |
1088 | ||
b4a708fb | 1089 | /* Set the BB_INFO so that the last insn is marked as a wild read of |
1090 | non-frame locations. */ | |
1091 | ||
1092 | static void | |
1093 | add_non_frame_wild_read (bb_info_t bb_info) | |
1094 | { | |
1095 | insn_info_t insn_info = bb_info->last_insn; | |
1096 | insn_info->non_frame_wild_read = true; | |
1097 | free_read_records (bb_info); | |
1098 | reset_active_stores (); | |
1099 | } | |
3072d30e | 1100 | |
17e1318c | 1101 | /* Return true if X is a constant or one of the registers that behave |
1102 | as a constant over the life of a function. This is equivalent to | |
1103 | !rtx_varies_p for memory addresses. */ | |
3072d30e | 1104 | |
1105 | static bool | |
1106 | const_or_frame_p (rtx x) | |
1107 | { | |
0349edce | 1108 | if (CONSTANT_P (x)) |
1109 | return true; | |
1110 | ||
1111 | if (GET_CODE (x) == REG) | |
3072d30e | 1112 | { |
3072d30e | 1113 | /* Note that we have to test for the actual rtx used for the frame |
1114 | and arg pointers and not just the register number in case we have | |
1115 | eliminated the frame and/or arg pointer and are using it | |
1116 | for pseudos. */ | |
1117 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx | |
1118 | /* The arg pointer varies if it is not a fixed register. */ | |
1119 | || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
1120 | || x == pic_offset_table_rtx) | |
1121 | return true; | |
1122 | return false; | |
3072d30e | 1123 | } |
55c5ac9f | 1124 | |
0349edce | 1125 | return false; |
3072d30e | 1126 | } |
1127 | ||
48e1416a | 1128 | /* Take all reasonable action to put the address of MEM into the form |
1129 | that we can do analysis on. | |
3072d30e | 1130 | |
1131 | The gold standard is to get the address into the form: address + | |
1132 | OFFSET where address is something that rtx_varies_p considers a | |
1133 | constant. When we can get the address in this form, we can do | |
1134 | global analysis on it. Note that for constant bases, address is | |
1135 | not actually returned, only the group_id. The address can be | |
1136 | obtained from that. | |
1137 | ||
1138 | If that fails, we try cselib to get a value we can at least use | |
48e1416a | 1139 | locally. If that fails we return false. |
1140 | ||
3072d30e | 1141 | The GROUP_ID is set to -1 for cselib bases and the index of the |
1142 | group for non_varying bases. | |
1143 | ||
1144 | FOR_READ is true if this is a mem read and false if not. */ | |
1145 | ||
1146 | static bool | |
1147 | canon_address (rtx mem, | |
32c2fdea | 1148 | alias_set_type *alias_set_out, |
3072d30e | 1149 | int *group_id, |
48e1416a | 1150 | HOST_WIDE_INT *offset, |
3072d30e | 1151 | cselib_val **base) |
1152 | { | |
3754d046 | 1153 | machine_mode address_mode = get_address_mode (mem); |
3072d30e | 1154 | rtx mem_address = XEXP (mem, 0); |
1155 | rtx expanded_address, address; | |
627540ce | 1156 | int expanded; |
1157 | ||
3072d30e | 1158 | *alias_set_out = 0; |
1159 | ||
1f864115 | 1160 | cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem)); |
3072d30e | 1161 | |
1ca59310 | 1162 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1163 | { |
1164 | fprintf (dump_file, " mem: "); | |
1165 | print_inline_rtx (dump_file, mem_address, 0); | |
1166 | fprintf (dump_file, "\n"); | |
1167 | } | |
1168 | ||
627540ce | 1169 | /* First see if just canon_rtx (mem_address) is const or frame, |
1170 | if not, try cselib_expand_value_rtx and call canon_rtx on that. */ | |
1171 | address = NULL_RTX; | |
1172 | for (expanded = 0; expanded < 2; expanded++) | |
1173 | { | |
1174 | if (expanded) | |
1175 | { | |
1176 | /* Use cselib to replace all of the reg references with the full | |
48e1416a | 1177 | expression. This will take care of the case where we have |
3072d30e | 1178 | |
627540ce | 1179 | r_x = base + offset; |
1180 | val = *r_x; | |
48e1416a | 1181 | |
1182 | by making it into | |
3072d30e | 1183 | |
627540ce | 1184 | val = *(base + offset); */ |
3072d30e | 1185 | |
627540ce | 1186 | expanded_address = cselib_expand_value_rtx (mem_address, |
1187 | scratch, 5); | |
3072d30e | 1188 | |
627540ce | 1189 | /* If this fails, just go with the address from first |
1190 | iteration. */ | |
1191 | if (!expanded_address) | |
1192 | break; | |
1193 | } | |
1194 | else | |
1195 | expanded_address = mem_address; | |
3072d30e | 1196 | |
627540ce | 1197 | /* Split the address into canonical BASE + OFFSET terms. */ |
1198 | address = canon_rtx (expanded_address); | |
3072d30e | 1199 | |
627540ce | 1200 | *offset = 0; |
3072d30e | 1201 | |
1ca59310 | 1202 | if (dump_file && (dump_flags & TDF_DETAILS)) |
627540ce | 1203 | { |
1204 | if (expanded) | |
1205 | { | |
1206 | fprintf (dump_file, "\n after cselib_expand address: "); | |
1207 | print_inline_rtx (dump_file, expanded_address, 0); | |
1208 | fprintf (dump_file, "\n"); | |
1209 | } | |
3072d30e | 1210 | |
627540ce | 1211 | fprintf (dump_file, "\n after canon_rtx address: "); |
1212 | print_inline_rtx (dump_file, address, 0); | |
1213 | fprintf (dump_file, "\n"); | |
1214 | } | |
3072d30e | 1215 | |
627540ce | 1216 | if (GET_CODE (address) == CONST) |
1217 | address = XEXP (address, 0); | |
3072d30e | 1218 | |
627540ce | 1219 | if (GET_CODE (address) == PLUS |
1220 | && CONST_INT_P (XEXP (address, 1))) | |
1221 | { | |
1222 | *offset = INTVAL (XEXP (address, 1)); | |
1223 | address = XEXP (address, 0); | |
1224 | } | |
3072d30e | 1225 | |
bd1a81f7 | 1226 | if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem)) |
1227 | && const_or_frame_p (address)) | |
3072d30e | 1228 | { |
c2eab334 | 1229 | group_info *group = get_group_info (address); |
627540ce | 1230 | |
1ca59310 | 1231 | if (dump_file && (dump_flags & TDF_DETAILS)) |
627540ce | 1232 | fprintf (dump_file, " gid=%d offset=%d \n", |
1233 | group->id, (int)*offset); | |
1234 | *base = NULL; | |
1235 | *group_id = group->id; | |
1236 | return true; | |
3072d30e | 1237 | } |
627540ce | 1238 | } |
1239 | ||
1f864115 | 1240 | *base = cselib_lookup (address, address_mode, true, GET_MODE (mem)); |
627540ce | 1241 | *group_id = -1; |
1242 | ||
1243 | if (*base == NULL) | |
1244 | { | |
1ca59310 | 1245 | if (dump_file && (dump_flags & TDF_DETAILS)) |
627540ce | 1246 | fprintf (dump_file, " no cselib val - should be a wild read.\n"); |
1247 | return false; | |
3072d30e | 1248 | } |
1ca59310 | 1249 | if (dump_file && (dump_flags & TDF_DETAILS)) |
01df1184 | 1250 | fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n", |
1251 | (*base)->uid, (*base)->hash, (int)*offset); | |
3072d30e | 1252 | return true; |
1253 | } | |
1254 | ||
1255 | ||
1256 | /* Clear the rhs field from the active_local_stores array. */ | |
1257 | ||
1258 | static void | |
1259 | clear_rhs_from_active_local_stores (void) | |
1260 | { | |
1261 | insn_info_t ptr = active_local_stores; | |
1262 | ||
1263 | while (ptr) | |
1264 | { | |
c2eab334 | 1265 | store_info *store_info = ptr->store_rec; |
3072d30e | 1266 | /* Skip the clobbers. */ |
1267 | while (!store_info->is_set) | |
1268 | store_info = store_info->next; | |
1269 | ||
1270 | store_info->rhs = NULL; | |
aa140b76 | 1271 | store_info->const_rhs = NULL; |
3072d30e | 1272 | |
1273 | ptr = ptr->next_local_store; | |
1274 | } | |
1275 | } | |
1276 | ||
1277 | ||
aa140b76 | 1278 | /* Mark byte POS bytes from the beginning of store S_INFO as unneeded. */ |
1279 | ||
1280 | static inline void | |
c2eab334 | 1281 | set_position_unneeded (store_info *s_info, int pos) |
aa140b76 | 1282 | { |
1283 | if (__builtin_expect (s_info->is_large, false)) | |
1284 | { | |
6ef9bbe0 | 1285 | if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos)) |
1286 | s_info->positions_needed.large.count++; | |
aa140b76 | 1287 | } |
1288 | else | |
1289 | s_info->positions_needed.small_bitmask | |
1290 | &= ~(((unsigned HOST_WIDE_INT) 1) << pos); | |
1291 | } | |
1292 | ||
1293 | /* Mark the whole store S_INFO as unneeded. */ | |
1294 | ||
1295 | static inline void | |
c2eab334 | 1296 | set_all_positions_unneeded (store_info *s_info) |
aa140b76 | 1297 | { |
1298 | if (__builtin_expect (s_info->is_large, false)) | |
1299 | { | |
1300 | int pos, end = s_info->end - s_info->begin; | |
1301 | for (pos = 0; pos < end; pos++) | |
843bd2fa | 1302 | bitmap_set_bit (s_info->positions_needed.large.bmap, pos); |
aa140b76 | 1303 | s_info->positions_needed.large.count = end; |
1304 | } | |
1305 | else | |
1306 | s_info->positions_needed.small_bitmask = (unsigned HOST_WIDE_INT) 0; | |
1307 | } | |
1308 | ||
1309 | /* Return TRUE if any bytes from S_INFO store are needed. */ | |
1310 | ||
1311 | static inline bool | |
c2eab334 | 1312 | any_positions_needed_p (store_info *s_info) |
aa140b76 | 1313 | { |
1314 | if (__builtin_expect (s_info->is_large, false)) | |
1315 | return (s_info->positions_needed.large.count | |
1316 | < s_info->end - s_info->begin); | |
1317 | else | |
1318 | return (s_info->positions_needed.small_bitmask | |
1319 | != (unsigned HOST_WIDE_INT) 0); | |
1320 | } | |
1321 | ||
1322 | /* Return TRUE if all bytes START through START+WIDTH-1 from S_INFO | |
1323 | store are needed. */ | |
1324 | ||
1325 | static inline bool | |
c2eab334 | 1326 | all_positions_needed_p (store_info *s_info, int start, int width) |
aa140b76 | 1327 | { |
1328 | if (__builtin_expect (s_info->is_large, false)) | |
1329 | { | |
1330 | int end = start + width; | |
1331 | while (start < end) | |
843bd2fa | 1332 | if (bitmap_bit_p (s_info->positions_needed.large.bmap, start++)) |
aa140b76 | 1333 | return false; |
1334 | return true; | |
1335 | } | |
1336 | else | |
1337 | { | |
1338 | unsigned HOST_WIDE_INT mask = lowpart_bitmask (width) << start; | |
1339 | return (s_info->positions_needed.small_bitmask & mask) == mask; | |
1340 | } | |
1341 | } | |
1342 | ||
1343 | ||
c2eab334 | 1344 | static rtx get_stored_val (store_info *, machine_mode, HOST_WIDE_INT, |
aa140b76 | 1345 | HOST_WIDE_INT, basic_block, bool); |
1346 | ||
1347 | ||
3072d30e | 1348 | /* BODY is an instruction pattern that belongs to INSN. Return 1 if |
1349 | there is a candidate store, after adding it to the appropriate | |
1350 | local store group if so. */ | |
1351 | ||
1352 | static int | |
1353 | record_store (rtx body, bb_info_t bb_info) | |
1354 | { | |
82d2c88b | 1355 | rtx mem, rhs, const_rhs, mem_addr; |
3072d30e | 1356 | HOST_WIDE_INT offset = 0; |
1357 | HOST_WIDE_INT width = 0; | |
32c2fdea | 1358 | alias_set_type spill_alias_set; |
3072d30e | 1359 | insn_info_t insn_info = bb_info->last_insn; |
c2eab334 | 1360 | store_info *store_info = NULL; |
3072d30e | 1361 | int group_id; |
1362 | cselib_val *base = NULL; | |
aa140b76 | 1363 | insn_info_t ptr, last, redundant_reason; |
3072d30e | 1364 | bool store_is_unused; |
1365 | ||
1366 | if (GET_CODE (body) != SET && GET_CODE (body) != CLOBBER) | |
1367 | return 0; | |
1368 | ||
aa140b76 | 1369 | mem = SET_DEST (body); |
1370 | ||
3072d30e | 1371 | /* If this is not used, then this cannot be used to keep the insn |
1372 | from being deleted. On the other hand, it does provide something | |
1373 | that can be used to prove that another store is dead. */ | |
1374 | store_is_unused | |
aa140b76 | 1375 | = (find_reg_note (insn_info->insn, REG_UNUSED, mem) != NULL); |
3072d30e | 1376 | |
1377 | /* Check whether that value is a suitable memory location. */ | |
3072d30e | 1378 | if (!MEM_P (mem)) |
1379 | { | |
1380 | /* If the set or clobber is unused, then it does not effect our | |
1381 | ability to get rid of the entire insn. */ | |
1382 | if (!store_is_unused) | |
1383 | insn_info->cannot_delete = true; | |
1384 | return 0; | |
1385 | } | |
1386 | ||
1387 | /* At this point we know mem is a mem. */ | |
1388 | if (GET_MODE (mem) == BLKmode) | |
1389 | { | |
1390 | if (GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
1391 | { | |
1ca59310 | 1392 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1393 | fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n"); |
1394 | add_wild_read (bb_info); | |
1395 | insn_info->cannot_delete = true; | |
aa140b76 | 1396 | return 0; |
3072d30e | 1397 | } |
aa140b76 | 1398 | /* Handle (set (mem:BLK (addr) [... S36 ...]) (const_int 0)) |
1399 | as memset (addr, 0, 36); */ | |
5b2a69fa | 1400 | else if (!MEM_SIZE_KNOWN_P (mem) |
1401 | || MEM_SIZE (mem) <= 0 | |
1402 | || MEM_SIZE (mem) > MAX_OFFSET | |
aa140b76 | 1403 | || GET_CODE (body) != SET |
aa140b76 | 1404 | || !CONST_INT_P (SET_SRC (body))) |
3072d30e | 1405 | { |
aa140b76 | 1406 | if (!store_is_unused) |
1407 | { | |
1408 | /* If the set or clobber is unused, then it does not effect our | |
1409 | ability to get rid of the entire insn. */ | |
1410 | insn_info->cannot_delete = true; | |
1411 | clear_rhs_from_active_local_stores (); | |
1412 | } | |
1413 | return 0; | |
3072d30e | 1414 | } |
3072d30e | 1415 | } |
1416 | ||
1417 | /* We can still process a volatile mem, we just cannot delete it. */ | |
1418 | if (MEM_VOLATILE_P (mem)) | |
aa140b76 | 1419 | insn_info->cannot_delete = true; |
3072d30e | 1420 | |
1421 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
1422 | { | |
1423 | clear_rhs_from_active_local_stores (); | |
1424 | return 0; | |
1425 | } | |
1426 | ||
aa140b76 | 1427 | if (GET_MODE (mem) == BLKmode) |
5b2a69fa | 1428 | width = MEM_SIZE (mem); |
aa140b76 | 1429 | else |
e4209874 | 1430 | width = GET_MODE_SIZE (GET_MODE (mem)); |
3072d30e | 1431 | |
1432 | if (spill_alias_set) | |
1433 | { | |
1434 | bitmap store1 = clear_alias_group->store1_p; | |
1435 | bitmap store2 = clear_alias_group->store2_p; | |
aa140b76 | 1436 | |
1437 | gcc_assert (GET_MODE (mem) != BLKmode); | |
48e1416a | 1438 | |
6ef9bbe0 | 1439 | if (!bitmap_set_bit (store1, spill_alias_set)) |
3072d30e | 1440 | bitmap_set_bit (store2, spill_alias_set); |
48e1416a | 1441 | |
3072d30e | 1442 | if (clear_alias_group->offset_map_size_p < spill_alias_set) |
1443 | clear_alias_group->offset_map_size_p = spill_alias_set; | |
48e1416a | 1444 | |
55c5ac9f | 1445 | store_info = rtx_store_info_pool.allocate (); |
3072d30e | 1446 | |
1ca59310 | 1447 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1448 | fprintf (dump_file, " processing spill store %d(%s)\n", |
32c2fdea | 1449 | (int) spill_alias_set, GET_MODE_NAME (GET_MODE (mem))); |
3072d30e | 1450 | } |
1451 | else if (group_id >= 0) | |
1452 | { | |
1453 | /* In the restrictive case where the base is a constant or the | |
1454 | frame pointer we can do global analysis. */ | |
48e1416a | 1455 | |
c2eab334 | 1456 | group_info *group |
f1f41a6c | 1457 | = rtx_group_vec[group_id]; |
b4a708fb | 1458 | tree expr = MEM_EXPR (mem); |
48e1416a | 1459 | |
55c5ac9f | 1460 | store_info = rtx_store_info_pool.allocate (); |
b4a708fb | 1461 | set_usage_bits (group, offset, width, expr); |
3072d30e | 1462 | |
1ca59310 | 1463 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1464 | fprintf (dump_file, " processing const base store gid=%d[%d..%d)\n", |
1465 | group_id, (int)offset, (int)(offset+width)); | |
1466 | } | |
1467 | else | |
1468 | { | |
86e87ef6 | 1469 | if (may_be_sp_based_p (XEXP (mem, 0))) |
17e1318c | 1470 | insn_info->stack_pointer_based = true; |
3072d30e | 1471 | insn_info->contains_cselib_groups = true; |
17e1318c | 1472 | |
55c5ac9f | 1473 | store_info = cse_store_info_pool.allocate (); |
3072d30e | 1474 | group_id = -1; |
1475 | ||
1ca59310 | 1476 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1477 | fprintf (dump_file, " processing cselib store [%d..%d)\n", |
1478 | (int)offset, (int)(offset+width)); | |
1479 | } | |
1480 | ||
aa140b76 | 1481 | const_rhs = rhs = NULL_RTX; |
1482 | if (GET_CODE (body) == SET | |
1483 | /* No place to keep the value after ra. */ | |
1484 | && !reload_completed | |
1485 | && (REG_P (SET_SRC (body)) | |
1486 | || GET_CODE (SET_SRC (body)) == SUBREG | |
1487 | || CONSTANT_P (SET_SRC (body))) | |
1488 | && !MEM_VOLATILE_P (mem) | |
1489 | /* Sometimes the store and reload is used for truncation and | |
1490 | rounding. */ | |
1491 | && !(FLOAT_MODE_P (GET_MODE (mem)) && (flag_float_store))) | |
1492 | { | |
1493 | rhs = SET_SRC (body); | |
1494 | if (CONSTANT_P (rhs)) | |
1495 | const_rhs = rhs; | |
1496 | else if (body == PATTERN (insn_info->insn)) | |
1497 | { | |
1498 | rtx tem = find_reg_note (insn_info->insn, REG_EQUAL, NULL_RTX); | |
1499 | if (tem && CONSTANT_P (XEXP (tem, 0))) | |
1500 | const_rhs = XEXP (tem, 0); | |
1501 | } | |
1502 | if (const_rhs == NULL_RTX && REG_P (rhs)) | |
1503 | { | |
1504 | rtx tem = cselib_expand_value_rtx (rhs, scratch, 5); | |
1505 | ||
1506 | if (tem && CONSTANT_P (tem)) | |
1507 | const_rhs = tem; | |
1508 | } | |
1509 | } | |
1510 | ||
3072d30e | 1511 | /* Check to see if this stores causes some other stores to be |
1512 | dead. */ | |
1513 | ptr = active_local_stores; | |
1514 | last = NULL; | |
aa140b76 | 1515 | redundant_reason = NULL; |
82d2c88b | 1516 | mem = canon_rtx (mem); |
1517 | /* For alias_set != 0 canon_true_dependence should be never called. */ | |
1518 | if (spill_alias_set) | |
1519 | mem_addr = NULL_RTX; | |
1520 | else | |
1521 | { | |
1522 | if (group_id < 0) | |
1523 | mem_addr = base->val_rtx; | |
1524 | else | |
1525 | { | |
c2eab334 | 1526 | group_info *group |
f1f41a6c | 1527 | = rtx_group_vec[group_id]; |
82d2c88b | 1528 | mem_addr = group->canon_base_addr; |
1529 | } | |
90f3e775 | 1530 | /* get_addr can only handle VALUE but cannot handle expr like: |
1531 | VALUE + OFFSET, so call get_addr to get original addr for | |
1532 | mem_addr before plus_constant. */ | |
1533 | mem_addr = get_addr (mem_addr); | |
82d2c88b | 1534 | if (offset) |
87cf5753 | 1535 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
82d2c88b | 1536 | } |
3072d30e | 1537 | |
1538 | while (ptr) | |
1539 | { | |
1540 | insn_info_t next = ptr->next_local_store; | |
c2eab334 | 1541 | struct store_info *s_info = ptr->store_rec; |
9ce37fa7 | 1542 | bool del = true; |
3072d30e | 1543 | |
1544 | /* Skip the clobbers. We delete the active insn if this insn | |
6dfdc153 | 1545 | shadows the set. To have been put on the active list, it |
3072d30e | 1546 | has exactly on set. */ |
1547 | while (!s_info->is_set) | |
1548 | s_info = s_info->next; | |
1549 | ||
1550 | if (s_info->alias_set != spill_alias_set) | |
9ce37fa7 | 1551 | del = false; |
3072d30e | 1552 | else if (s_info->alias_set) |
1553 | { | |
48e1416a | 1554 | struct clear_alias_mode_holder *entry |
3072d30e | 1555 | = clear_alias_set_lookup (s_info->alias_set); |
1556 | /* Generally, spills cannot be processed if and of the | |
1557 | references to the slot have a different mode. But if | |
1558 | we are in the same block and mode is exactly the same | |
1559 | between this store and one before in the same block, | |
1560 | we can still delete it. */ | |
1561 | if ((GET_MODE (mem) == GET_MODE (s_info->mem)) | |
1562 | && (GET_MODE (mem) == entry->mode)) | |
1563 | { | |
9ce37fa7 | 1564 | del = true; |
aa140b76 | 1565 | set_all_positions_unneeded (s_info); |
3072d30e | 1566 | } |
1ca59310 | 1567 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1568 | fprintf (dump_file, " trying spill store in insn=%d alias_set=%d\n", |
32c2fdea | 1569 | INSN_UID (ptr->insn), (int) s_info->alias_set); |
3072d30e | 1570 | } |
48e1416a | 1571 | else if ((s_info->group_id == group_id) |
3072d30e | 1572 | && (s_info->cse_base == base)) |
1573 | { | |
1574 | HOST_WIDE_INT i; | |
1ca59310 | 1575 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 1576 | fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n", |
48e1416a | 1577 | INSN_UID (ptr->insn), s_info->group_id, |
3072d30e | 1578 | (int)s_info->begin, (int)s_info->end); |
aa140b76 | 1579 | |
1580 | /* Even if PTR won't be eliminated as unneeded, if both | |
1581 | PTR and this insn store the same constant value, we might | |
1582 | eliminate this insn instead. */ | |
1583 | if (s_info->const_rhs | |
1584 | && const_rhs | |
1585 | && offset >= s_info->begin | |
1586 | && offset + width <= s_info->end | |
1587 | && all_positions_needed_p (s_info, offset - s_info->begin, | |
1588 | width)) | |
1589 | { | |
1590 | if (GET_MODE (mem) == BLKmode) | |
1591 | { | |
1592 | if (GET_MODE (s_info->mem) == BLKmode | |
1593 | && s_info->const_rhs == const_rhs) | |
1594 | redundant_reason = ptr; | |
1595 | } | |
1596 | else if (s_info->const_rhs == const0_rtx | |
1597 | && const_rhs == const0_rtx) | |
1598 | redundant_reason = ptr; | |
1599 | else | |
1600 | { | |
1601 | rtx val; | |
1602 | start_sequence (); | |
1603 | val = get_stored_val (s_info, GET_MODE (mem), | |
1604 | offset, offset + width, | |
1605 | BLOCK_FOR_INSN (insn_info->insn), | |
1606 | true); | |
1607 | if (get_insns () != NULL) | |
1608 | val = NULL_RTX; | |
1609 | end_sequence (); | |
1610 | if (val && rtx_equal_p (val, const_rhs)) | |
1611 | redundant_reason = ptr; | |
1612 | } | |
1613 | } | |
1614 | ||
1615 | for (i = MAX (offset, s_info->begin); | |
1616 | i < offset + width && i < s_info->end; | |
1617 | i++) | |
1618 | set_position_unneeded (s_info, i - s_info->begin); | |
3072d30e | 1619 | } |
1620 | else if (s_info->rhs) | |
1621 | /* Need to see if it is possible for this store to overwrite | |
1622 | the value of store_info. If it is, set the rhs to NULL to | |
1623 | keep it from being used to remove a load. */ | |
1624 | { | |
48e1416a | 1625 | if (canon_true_dependence (s_info->mem, |
3072d30e | 1626 | GET_MODE (s_info->mem), |
1627 | s_info->mem_addr, | |
376a287d | 1628 | mem, mem_addr)) |
aa140b76 | 1629 | { |
1630 | s_info->rhs = NULL; | |
1631 | s_info->const_rhs = NULL; | |
1632 | } | |
3072d30e | 1633 | } |
82d2c88b | 1634 | |
3072d30e | 1635 | /* An insn can be deleted if every position of every one of |
1636 | its s_infos is zero. */ | |
c75be2fe | 1637 | if (any_positions_needed_p (s_info)) |
9ce37fa7 | 1638 | del = false; |
aa140b76 | 1639 | |
9ce37fa7 | 1640 | if (del) |
3072d30e | 1641 | { |
1642 | insn_info_t insn_to_delete = ptr; | |
48e1416a | 1643 | |
1242bee6 | 1644 | active_local_stores_len--; |
3072d30e | 1645 | if (last) |
1646 | last->next_local_store = ptr->next_local_store; | |
1647 | else | |
1648 | active_local_stores = ptr->next_local_store; | |
48e1416a | 1649 | |
c75be2fe | 1650 | if (!insn_to_delete->cannot_delete) |
1651 | delete_dead_store_insn (insn_to_delete); | |
3072d30e | 1652 | } |
1653 | else | |
1654 | last = ptr; | |
48e1416a | 1655 | |
3072d30e | 1656 | ptr = next; |
1657 | } | |
48e1416a | 1658 | |
3072d30e | 1659 | /* Finish filling in the store_info. */ |
1660 | store_info->next = insn_info->store_rec; | |
1661 | insn_info->store_rec = store_info; | |
82d2c88b | 1662 | store_info->mem = mem; |
3072d30e | 1663 | store_info->alias_set = spill_alias_set; |
82d2c88b | 1664 | store_info->mem_addr = mem_addr; |
3072d30e | 1665 | store_info->cse_base = base; |
aa140b76 | 1666 | if (width > HOST_BITS_PER_WIDE_INT) |
1667 | { | |
1668 | store_info->is_large = true; | |
1669 | store_info->positions_needed.large.count = 0; | |
4fb07d00 | 1670 | store_info->positions_needed.large.bmap = BITMAP_ALLOC (&dse_bitmap_obstack); |
aa140b76 | 1671 | } |
1672 | else | |
1673 | { | |
1674 | store_info->is_large = false; | |
1675 | store_info->positions_needed.small_bitmask = lowpart_bitmask (width); | |
1676 | } | |
3072d30e | 1677 | store_info->group_id = group_id; |
1678 | store_info->begin = offset; | |
1679 | store_info->end = offset + width; | |
1680 | store_info->is_set = GET_CODE (body) == SET; | |
aa140b76 | 1681 | store_info->rhs = rhs; |
1682 | store_info->const_rhs = const_rhs; | |
1683 | store_info->redundant_reason = redundant_reason; | |
3072d30e | 1684 | |
3072d30e | 1685 | /* If this is a clobber, we return 0. We will only be able to |
1686 | delete this insn if there is only one store USED store, but we | |
1687 | can use the clobber to delete other stores earlier. */ | |
1688 | return store_info->is_set ? 1 : 0; | |
1689 | } | |
1690 | ||
1691 | ||
1692 | static void | |
1693 | dump_insn_info (const char * start, insn_info_t insn_info) | |
1694 | { | |
48e1416a | 1695 | fprintf (dump_file, "%s insn=%d %s\n", start, |
3072d30e | 1696 | INSN_UID (insn_info->insn), |
1697 | insn_info->store_rec ? "has store" : "naked"); | |
1698 | } | |
1699 | ||
1700 | ||
5c9051a4 | 1701 | /* If the modes are different and the value's source and target do not |
1702 | line up, we need to extract the value from lower part of the rhs of | |
1703 | the store, shift it, and then put it into a form that can be shoved | |
1704 | into the read_insn. This function generates a right SHIFT of a | |
1705 | value that is at least ACCESS_SIZE bytes wide of READ_MODE. The | |
1706 | shift sequence is returned or NULL if we failed to find a | |
1707 | shift. */ | |
1708 | ||
1709 | static rtx | |
10d4de0e | 1710 | find_shift_sequence (int access_size, |
c2eab334 | 1711 | store_info *store_info, |
3754d046 | 1712 | machine_mode read_mode, |
aa140b76 | 1713 | int shift, bool speed, bool require_cst) |
5c9051a4 | 1714 | { |
3754d046 | 1715 | machine_mode store_mode = GET_MODE (store_info->mem); |
1716 | machine_mode new_mode; | |
10d4de0e | 1717 | rtx read_reg = NULL; |
5c9051a4 | 1718 | |
1719 | /* Some machines like the x86 have shift insns for each size of | |
1720 | operand. Other machines like the ppc or the ia-64 may only have | |
1721 | shift insns that shift values within 32 or 64 bit registers. | |
1722 | This loop tries to find the smallest shift insn that will right | |
1723 | justify the value we want to read but is available in one insn on | |
1724 | the machine. */ | |
1725 | ||
10d4de0e | 1726 | for (new_mode = smallest_mode_for_size (access_size * BITS_PER_UNIT, |
1727 | MODE_INT); | |
1728 | GET_MODE_BITSIZE (new_mode) <= BITS_PER_WORD; | |
1729 | new_mode = GET_MODE_WIDER_MODE (new_mode)) | |
5c9051a4 | 1730 | { |
4cd001d5 | 1731 | rtx target, new_reg, new_lhs; |
1732 | rtx_insn *shift_seq, *insn; | |
171557e8 | 1733 | int cost; |
af97461e | 1734 | |
4ed4afb9 | 1735 | /* If a constant was stored into memory, try to simplify it here, |
1736 | otherwise the cost of the shift might preclude this optimization | |
1737 | e.g. at -Os, even when no actual shift will be needed. */ | |
aa140b76 | 1738 | if (store_info->const_rhs) |
4ed4afb9 | 1739 | { |
1740 | unsigned int byte = subreg_lowpart_offset (new_mode, store_mode); | |
aa140b76 | 1741 | rtx ret = simplify_subreg (new_mode, store_info->const_rhs, |
1742 | store_mode, byte); | |
4ed4afb9 | 1743 | if (ret && CONSTANT_P (ret)) |
1744 | { | |
1745 | ret = simplify_const_binary_operation (LSHIFTRT, new_mode, | |
1746 | ret, GEN_INT (shift)); | |
1747 | if (ret && CONSTANT_P (ret)) | |
1748 | { | |
1749 | byte = subreg_lowpart_offset (read_mode, new_mode); | |
1750 | ret = simplify_subreg (read_mode, ret, new_mode, byte); | |
1751 | if (ret && CONSTANT_P (ret) | |
5ae4887d | 1752 | && (set_src_cost (ret, read_mode, speed) |
1753 | <= COSTS_N_INSNS (1))) | |
4ed4afb9 | 1754 | return ret; |
1755 | } | |
1756 | } | |
1757 | } | |
1758 | ||
aa140b76 | 1759 | if (require_cst) |
1760 | return NULL_RTX; | |
1761 | ||
10d4de0e | 1762 | /* Try a wider mode if truncating the store mode to NEW_MODE |
1763 | requires a real instruction. */ | |
1764 | if (GET_MODE_BITSIZE (new_mode) < GET_MODE_BITSIZE (store_mode) | |
396f2130 | 1765 | && !TRULY_NOOP_TRUNCATION_MODES_P (new_mode, store_mode)) |
af97461e | 1766 | continue; |
1767 | ||
10d4de0e | 1768 | /* Also try a wider mode if the necessary punning is either not |
1769 | desirable or not possible. */ | |
1770 | if (!CONSTANT_P (store_info->rhs) | |
1771 | && !MODES_TIEABLE_P (new_mode, store_mode)) | |
1772 | continue; | |
10d4de0e | 1773 | |
af97461e | 1774 | new_reg = gen_reg_rtx (new_mode); |
5c9051a4 | 1775 | |
1776 | start_sequence (); | |
1777 | ||
1778 | /* In theory we could also check for an ashr. Ian Taylor knows | |
1779 | of one dsp where the cost of these two was not the same. But | |
1780 | this really is a rare case anyway. */ | |
1781 | target = expand_binop (new_mode, lshr_optab, new_reg, | |
1782 | GEN_INT (shift), new_reg, 1, OPTAB_DIRECT); | |
1783 | ||
597d5470 | 1784 | shift_seq = get_insns (); |
1785 | end_sequence (); | |
5c9051a4 | 1786 | |
597d5470 | 1787 | if (target != new_reg || shift_seq == NULL) |
1788 | continue; | |
1789 | ||
1790 | cost = 0; | |
1791 | for (insn = shift_seq; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
1792 | if (INSN_P (insn)) | |
f529eb25 | 1793 | cost += insn_rtx_cost (PATTERN (insn), speed); |
597d5470 | 1794 | |
1795 | /* The computation up to here is essentially independent | |
1796 | of the arguments and could be precomputed. It may | |
1797 | not be worth doing so. We could precompute if | |
1798 | worthwhile or at least cache the results. The result | |
5133fd21 | 1799 | technically depends on both SHIFT and ACCESS_SIZE, |
1800 | but in practice the answer will depend only on ACCESS_SIZE. */ | |
597d5470 | 1801 | |
1802 | if (cost > COSTS_N_INSNS (1)) | |
1803 | continue; | |
1804 | ||
171557e8 | 1805 | new_lhs = extract_low_bits (new_mode, store_mode, |
1806 | copy_rtx (store_info->rhs)); | |
1807 | if (new_lhs == NULL_RTX) | |
1808 | continue; | |
1809 | ||
597d5470 | 1810 | /* We found an acceptable shift. Generate a move to |
1811 | take the value from the store and put it into the | |
1812 | shift pseudo, then shift it, then generate another | |
1813 | move to put in into the target of the read. */ | |
10d4de0e | 1814 | emit_move_insn (new_reg, new_lhs); |
597d5470 | 1815 | emit_insn (shift_seq); |
10d4de0e | 1816 | read_reg = extract_low_bits (read_mode, new_mode, new_reg); |
597d5470 | 1817 | break; |
5c9051a4 | 1818 | } |
1819 | ||
10d4de0e | 1820 | return read_reg; |
5c9051a4 | 1821 | } |
1822 | ||
1823 | ||
a1b0a968 | 1824 | /* Call back for note_stores to find the hard regs set or clobbered by |
1825 | insn. Data is a bitmap of the hardregs set so far. */ | |
1826 | ||
1827 | static void | |
1828 | look_for_hardregs (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) | |
1829 | { | |
1830 | bitmap regs_set = (bitmap) data; | |
1831 | ||
1832 | if (REG_P (x) | |
771d4616 | 1833 | && HARD_REGISTER_P (x)) |
0933f1d9 | 1834 | bitmap_set_range (regs_set, REGNO (x), REG_NREGS (x)); |
a1b0a968 | 1835 | } |
1836 | ||
aa140b76 | 1837 | /* Helper function for replace_read and record_store. |
1838 | Attempt to return a value stored in STORE_INFO, from READ_BEGIN | |
1839 | to one before READ_END bytes read in READ_MODE. Return NULL | |
1840 | if not successful. If REQUIRE_CST is true, return always constant. */ | |
1841 | ||
1842 | static rtx | |
c2eab334 | 1843 | get_stored_val (store_info *store_info, machine_mode read_mode, |
aa140b76 | 1844 | HOST_WIDE_INT read_begin, HOST_WIDE_INT read_end, |
1845 | basic_block bb, bool require_cst) | |
1846 | { | |
3754d046 | 1847 | machine_mode store_mode = GET_MODE (store_info->mem); |
aa140b76 | 1848 | int shift; |
1849 | int access_size; /* In bytes. */ | |
1850 | rtx read_reg; | |
1851 | ||
1852 | /* To get here the read is within the boundaries of the write so | |
1853 | shift will never be negative. Start out with the shift being in | |
1854 | bytes. */ | |
1855 | if (store_mode == BLKmode) | |
1856 | shift = 0; | |
1857 | else if (BYTES_BIG_ENDIAN) | |
1858 | shift = store_info->end - read_end; | |
1859 | else | |
1860 | shift = read_begin - store_info->begin; | |
1861 | ||
1862 | access_size = shift + GET_MODE_SIZE (read_mode); | |
1863 | ||
1864 | /* From now on it is bits. */ | |
1865 | shift *= BITS_PER_UNIT; | |
1866 | ||
1867 | if (shift) | |
1868 | read_reg = find_shift_sequence (access_size, store_info, read_mode, shift, | |
1869 | optimize_bb_for_speed_p (bb), | |
1870 | require_cst); | |
1871 | else if (store_mode == BLKmode) | |
1872 | { | |
1873 | /* The store is a memset (addr, const_val, const_size). */ | |
1874 | gcc_assert (CONST_INT_P (store_info->rhs)); | |
1875 | store_mode = int_mode_for_mode (read_mode); | |
1876 | if (store_mode == BLKmode) | |
1877 | read_reg = NULL_RTX; | |
1878 | else if (store_info->rhs == const0_rtx) | |
1879 | read_reg = extract_low_bits (read_mode, store_mode, const0_rtx); | |
1880 | else if (GET_MODE_BITSIZE (store_mode) > HOST_BITS_PER_WIDE_INT | |
1881 | || BITS_PER_UNIT >= HOST_BITS_PER_WIDE_INT) | |
1882 | read_reg = NULL_RTX; | |
1883 | else | |
1884 | { | |
1885 | unsigned HOST_WIDE_INT c | |
1886 | = INTVAL (store_info->rhs) | |
1887 | & (((HOST_WIDE_INT) 1 << BITS_PER_UNIT) - 1); | |
1888 | int shift = BITS_PER_UNIT; | |
1889 | while (shift < HOST_BITS_PER_WIDE_INT) | |
1890 | { | |
1891 | c |= (c << shift); | |
1892 | shift <<= 1; | |
1893 | } | |
f62058c3 | 1894 | read_reg = gen_int_mode (c, store_mode); |
aa140b76 | 1895 | read_reg = extract_low_bits (read_mode, store_mode, read_reg); |
1896 | } | |
1897 | } | |
1898 | else if (store_info->const_rhs | |
1899 | && (require_cst | |
1900 | || GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))) | |
1901 | read_reg = extract_low_bits (read_mode, store_mode, | |
1902 | copy_rtx (store_info->const_rhs)); | |
1903 | else | |
1904 | read_reg = extract_low_bits (read_mode, store_mode, | |
1905 | copy_rtx (store_info->rhs)); | |
1906 | if (require_cst && read_reg && !CONSTANT_P (read_reg)) | |
1907 | read_reg = NULL_RTX; | |
1908 | return read_reg; | |
1909 | } | |
a1b0a968 | 1910 | |
3072d30e | 1911 | /* Take a sequence of: |
1912 | A <- r1 | |
1913 | ... | |
1914 | ... <- A | |
1915 | ||
48e1416a | 1916 | and change it into |
3072d30e | 1917 | r2 <- r1 |
1918 | A <- r1 | |
1919 | ... | |
1920 | ... <- r2 | |
1921 | ||
5c9051a4 | 1922 | or |
1923 | ||
1924 | r3 <- extract (r1) | |
1925 | r3 <- r3 >> shift | |
1926 | r2 <- extract (r3) | |
1927 | ... <- r2 | |
1928 | ||
1929 | or | |
1930 | ||
1931 | r2 <- extract (r1) | |
1932 | ... <- r2 | |
1933 | ||
1934 | Depending on the alignment and the mode of the store and | |
1935 | subsequent load. | |
1936 | ||
1937 | ||
1938 | The STORE_INFO and STORE_INSN are for the store and READ_INFO | |
3072d30e | 1939 | and READ_INSN are for the read. Return true if the replacement |
1940 | went ok. */ | |
1941 | ||
1942 | static bool | |
c2eab334 | 1943 | replace_read (store_info *store_info, insn_info_t store_insn, |
aa140b76 | 1944 | read_info_t read_info, insn_info_t read_insn, rtx *loc, |
1945 | bitmap regs_live) | |
3072d30e | 1946 | { |
3754d046 | 1947 | machine_mode store_mode = GET_MODE (store_info->mem); |
1948 | machine_mode read_mode = GET_MODE (read_info->mem); | |
4cd001d5 | 1949 | rtx_insn *insns, *this_insn; |
1950 | rtx read_reg; | |
aa140b76 | 1951 | basic_block bb; |
5c9051a4 | 1952 | |
3072d30e | 1953 | if (!dbg_cnt (dse)) |
1954 | return false; | |
1955 | ||
10d4de0e | 1956 | /* Create a sequence of instructions to set up the read register. |
1957 | This sequence goes immediately before the store and its result | |
1958 | is read by the load. | |
1959 | ||
1960 | We need to keep this in perspective. We are replacing a read | |
5c9051a4 | 1961 | with a sequence of insns, but the read will almost certainly be |
1962 | in cache, so it is not going to be an expensive one. Thus, we | |
1963 | are not willing to do a multi insn shift or worse a subroutine | |
1964 | call to get rid of the read. */ | |
1ca59310 | 1965 | if (dump_file && (dump_flags & TDF_DETAILS)) |
10d4de0e | 1966 | fprintf (dump_file, "trying to replace %smode load in insn %d" |
1967 | " from %smode store in insn %d\n", | |
1968 | GET_MODE_NAME (read_mode), INSN_UID (read_insn->insn), | |
1969 | GET_MODE_NAME (store_mode), INSN_UID (store_insn->insn)); | |
1970 | start_sequence (); | |
aa140b76 | 1971 | bb = BLOCK_FOR_INSN (read_insn->insn); |
1972 | read_reg = get_stored_val (store_info, | |
1973 | read_mode, read_info->begin, read_info->end, | |
1974 | bb, false); | |
10d4de0e | 1975 | if (read_reg == NULL_RTX) |
5c9051a4 | 1976 | { |
10d4de0e | 1977 | end_sequence (); |
1ca59310 | 1978 | if (dump_file && (dump_flags & TDF_DETAILS)) |
10d4de0e | 1979 | fprintf (dump_file, " -- could not extract bits of stored value\n"); |
1980 | return false; | |
5c9051a4 | 1981 | } |
10d4de0e | 1982 | /* Force the value into a new register so that it won't be clobbered |
1983 | between the store and the load. */ | |
1984 | read_reg = copy_to_mode_reg (read_mode, read_reg); | |
1985 | insns = get_insns (); | |
1986 | end_sequence (); | |
5c9051a4 | 1987 | |
a1b0a968 | 1988 | if (insns != NULL_RTX) |
1989 | { | |
1990 | /* Now we have to scan the set of new instructions to see if the | |
1991 | sequence contains and sets of hardregs that happened to be | |
1992 | live at this point. For instance, this can happen if one of | |
1993 | the insns sets the CC and the CC happened to be live at that | |
1994 | point. This does occasionally happen, see PR 37922. */ | |
4fb07d00 | 1995 | bitmap regs_set = BITMAP_ALLOC (®_obstack); |
a1b0a968 | 1996 | |
1997 | for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn)) | |
1998 | note_stores (PATTERN (this_insn), look_for_hardregs, regs_set); | |
48e1416a | 1999 | |
a1b0a968 | 2000 | bitmap_and_into (regs_set, regs_live); |
2001 | if (!bitmap_empty_p (regs_set)) | |
2002 | { | |
1ca59310 | 2003 | if (dump_file && (dump_flags & TDF_DETAILS)) |
a1b0a968 | 2004 | { |
48e1416a | 2005 | fprintf (dump_file, |
a1b0a968 | 2006 | "abandoning replacement because sequence clobbers live hardregs:"); |
2007 | df_print_regset (dump_file, regs_set); | |
2008 | } | |
48e1416a | 2009 | |
a1b0a968 | 2010 | BITMAP_FREE (regs_set); |
2011 | return false; | |
2012 | } | |
2013 | BITMAP_FREE (regs_set); | |
2014 | } | |
2015 | ||
5c9051a4 | 2016 | if (validate_change (read_insn->insn, loc, read_reg, 0)) |
3072d30e | 2017 | { |
c2eab334 | 2018 | deferred_change *change = deferred_change_pool.allocate (); |
48e1416a | 2019 | |
5c9051a4 | 2020 | /* Insert this right before the store insn where it will be safe |
2021 | from later insns that might change it before the read. */ | |
2022 | emit_insn_before (insns, store_insn->insn); | |
48e1416a | 2023 | |
5c9051a4 | 2024 | /* And now for the kludge part: cselib croaks if you just |
2025 | return at this point. There are two reasons for this: | |
48e1416a | 2026 | |
5c9051a4 | 2027 | 1) Cselib has an idea of how many pseudos there are and |
2028 | that does not include the new ones we just added. | |
48e1416a | 2029 | |
5c9051a4 | 2030 | 2) Cselib does not know about the move insn we added |
2031 | above the store_info, and there is no way to tell it | |
2032 | about it, because it has "moved on". | |
48e1416a | 2033 | |
5c9051a4 | 2034 | Problem (1) is fixable with a certain amount of engineering. |
2035 | Problem (2) is requires starting the bb from scratch. This | |
2036 | could be expensive. | |
48e1416a | 2037 | |
5c9051a4 | 2038 | So we are just going to have to lie. The move/extraction |
2039 | insns are not really an issue, cselib did not see them. But | |
2040 | the use of the new pseudo read_insn is a real problem because | |
2041 | cselib has not scanned this insn. The way that we solve this | |
2042 | problem is that we are just going to put the mem back for now | |
2043 | and when we are finished with the block, we undo this. We | |
2044 | keep a table of mems to get rid of. At the end of the basic | |
2045 | block we can put them back. */ | |
48e1416a | 2046 | |
5c9051a4 | 2047 | *loc = read_info->mem; |
55c5ac9f | 2048 | change->next = deferred_change_list; |
2049 | deferred_change_list = change; | |
2050 | change->loc = loc; | |
2051 | change->reg = read_reg; | |
48e1416a | 2052 | |
5c9051a4 | 2053 | /* Get rid of the read_info, from the point of view of the |
2054 | rest of dse, play like this read never happened. */ | |
2055 | read_insn->read_rec = read_info->next; | |
e16712b1 | 2056 | read_info_type_pool.remove (read_info); |
1ca59310 | 2057 | if (dump_file && (dump_flags & TDF_DETAILS)) |
10d4de0e | 2058 | { |
2059 | fprintf (dump_file, " -- replaced the loaded MEM with "); | |
2060 | print_simple_rtl (dump_file, read_reg); | |
2061 | fprintf (dump_file, "\n"); | |
2062 | } | |
5c9051a4 | 2063 | return true; |
3072d30e | 2064 | } |
48e1416a | 2065 | else |
3072d30e | 2066 | { |
1ca59310 | 2067 | if (dump_file && (dump_flags & TDF_DETAILS)) |
10d4de0e | 2068 | { |
2069 | fprintf (dump_file, " -- replacing the loaded MEM with "); | |
2070 | print_simple_rtl (dump_file, read_reg); | |
2071 | fprintf (dump_file, " led to an invalid instruction\n"); | |
2072 | } | |
3072d30e | 2073 | return false; |
2074 | } | |
2075 | } | |
2076 | ||
ec1203cd | 2077 | /* Check the address of MEM *LOC and kill any appropriate stores that may |
2078 | be active. */ | |
3072d30e | 2079 | |
ec1203cd | 2080 | static void |
2081 | check_mem_read_rtx (rtx *loc, bb_info_t bb_info) | |
3072d30e | 2082 | { |
82d2c88b | 2083 | rtx mem = *loc, mem_addr; |
3072d30e | 2084 | insn_info_t insn_info; |
2085 | HOST_WIDE_INT offset = 0; | |
2086 | HOST_WIDE_INT width = 0; | |
32c2fdea | 2087 | alias_set_type spill_alias_set = 0; |
48e1416a | 2088 | cselib_val *base = NULL; |
3072d30e | 2089 | int group_id; |
2090 | read_info_t read_info; | |
2091 | ||
3072d30e | 2092 | insn_info = bb_info->last_insn; |
2093 | ||
2094 | if ((MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2095 | || (MEM_VOLATILE_P (mem))) | |
2096 | { | |
1ca59310 | 2097 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2098 | fprintf (dump_file, " adding wild read, volatile or barrier.\n"); |
2099 | add_wild_read (bb_info); | |
2100 | insn_info->cannot_delete = true; | |
ec1203cd | 2101 | return; |
3072d30e | 2102 | } |
2103 | ||
2104 | /* If it is reading readonly mem, then there can be no conflict with | |
2105 | another write. */ | |
2106 | if (MEM_READONLY_P (mem)) | |
ec1203cd | 2107 | return; |
3072d30e | 2108 | |
2109 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
2110 | { | |
1ca59310 | 2111 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2112 | fprintf (dump_file, " adding wild read, canon_address failure.\n"); |
2113 | add_wild_read (bb_info); | |
ec1203cd | 2114 | return; |
3072d30e | 2115 | } |
2116 | ||
2117 | if (GET_MODE (mem) == BLKmode) | |
2118 | width = -1; | |
2119 | else | |
2120 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
2121 | ||
e16712b1 | 2122 | read_info = read_info_type_pool.allocate (); |
3072d30e | 2123 | read_info->group_id = group_id; |
2124 | read_info->mem = mem; | |
2125 | read_info->alias_set = spill_alias_set; | |
2126 | read_info->begin = offset; | |
2127 | read_info->end = offset + width; | |
2128 | read_info->next = insn_info->read_rec; | |
2129 | insn_info->read_rec = read_info; | |
82d2c88b | 2130 | /* For alias_set != 0 canon_true_dependence should be never called. */ |
2131 | if (spill_alias_set) | |
2132 | mem_addr = NULL_RTX; | |
2133 | else | |
2134 | { | |
2135 | if (group_id < 0) | |
2136 | mem_addr = base->val_rtx; | |
2137 | else | |
2138 | { | |
c2eab334 | 2139 | group_info *group |
f1f41a6c | 2140 | = rtx_group_vec[group_id]; |
82d2c88b | 2141 | mem_addr = group->canon_base_addr; |
2142 | } | |
90f3e775 | 2143 | /* get_addr can only handle VALUE but cannot handle expr like: |
2144 | VALUE + OFFSET, so call get_addr to get original addr for | |
2145 | mem_addr before plus_constant. */ | |
2146 | mem_addr = get_addr (mem_addr); | |
82d2c88b | 2147 | if (offset) |
87cf5753 | 2148 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
82d2c88b | 2149 | } |
3072d30e | 2150 | |
bef304b8 | 2151 | /* We ignore the clobbers in store_info. The is mildly aggressive, |
3072d30e | 2152 | but there really should not be a clobber followed by a read. */ |
2153 | ||
2154 | if (spill_alias_set) | |
2155 | { | |
2156 | insn_info_t i_ptr = active_local_stores; | |
2157 | insn_info_t last = NULL; | |
2158 | ||
1ca59310 | 2159 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2160 | fprintf (dump_file, " processing spill load %d\n", |
32c2fdea | 2161 | (int) spill_alias_set); |
3072d30e | 2162 | |
2163 | while (i_ptr) | |
2164 | { | |
c2eab334 | 2165 | store_info *store_info = i_ptr->store_rec; |
3072d30e | 2166 | |
2167 | /* Skip the clobbers. */ | |
2168 | while (!store_info->is_set) | |
2169 | store_info = store_info->next; | |
48e1416a | 2170 | |
3072d30e | 2171 | if (store_info->alias_set == spill_alias_set) |
2172 | { | |
1ca59310 | 2173 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2174 | dump_insn_info ("removing from active", i_ptr); |
2175 | ||
1242bee6 | 2176 | active_local_stores_len--; |
3072d30e | 2177 | if (last) |
2178 | last->next_local_store = i_ptr->next_local_store; | |
2179 | else | |
2180 | active_local_stores = i_ptr->next_local_store; | |
2181 | } | |
2182 | else | |
2183 | last = i_ptr; | |
2184 | i_ptr = i_ptr->next_local_store; | |
2185 | } | |
2186 | } | |
2187 | else if (group_id >= 0) | |
2188 | { | |
2189 | /* This is the restricted case where the base is a constant or | |
2190 | the frame pointer and offset is a constant. */ | |
2191 | insn_info_t i_ptr = active_local_stores; | |
2192 | insn_info_t last = NULL; | |
48e1416a | 2193 | |
1ca59310 | 2194 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2195 | { |
2196 | if (width == -1) | |
2197 | fprintf (dump_file, " processing const load gid=%d[BLK]\n", | |
2198 | group_id); | |
2199 | else | |
2200 | fprintf (dump_file, " processing const load gid=%d[%d..%d)\n", | |
2201 | group_id, (int)offset, (int)(offset+width)); | |
2202 | } | |
2203 | ||
2204 | while (i_ptr) | |
2205 | { | |
2206 | bool remove = false; | |
c2eab334 | 2207 | store_info *store_info = i_ptr->store_rec; |
48e1416a | 2208 | |
3072d30e | 2209 | /* Skip the clobbers. */ |
2210 | while (!store_info->is_set) | |
2211 | store_info = store_info->next; | |
48e1416a | 2212 | |
3072d30e | 2213 | /* There are three cases here. */ |
2214 | if (store_info->group_id < 0) | |
2215 | /* We have a cselib store followed by a read from a | |
2216 | const base. */ | |
48e1416a | 2217 | remove |
2218 | = canon_true_dependence (store_info->mem, | |
3072d30e | 2219 | GET_MODE (store_info->mem), |
2220 | store_info->mem_addr, | |
376a287d | 2221 | mem, mem_addr); |
48e1416a | 2222 | |
3072d30e | 2223 | else if (group_id == store_info->group_id) |
2224 | { | |
2225 | /* This is a block mode load. We may get lucky and | |
2226 | canon_true_dependence may save the day. */ | |
2227 | if (width == -1) | |
48e1416a | 2228 | remove |
2229 | = canon_true_dependence (store_info->mem, | |
3072d30e | 2230 | GET_MODE (store_info->mem), |
2231 | store_info->mem_addr, | |
376a287d | 2232 | mem, mem_addr); |
48e1416a | 2233 | |
3072d30e | 2234 | /* If this read is just reading back something that we just |
2235 | stored, rewrite the read. */ | |
48e1416a | 2236 | else |
3072d30e | 2237 | { |
2238 | if (store_info->rhs | |
aa140b76 | 2239 | && offset >= store_info->begin |
2240 | && offset + width <= store_info->end | |
2241 | && all_positions_needed_p (store_info, | |
2242 | offset - store_info->begin, | |
2243 | width) | |
2244 | && replace_read (store_info, i_ptr, read_info, | |
2245 | insn_info, loc, bb_info->regs_live)) | |
ec1203cd | 2246 | return; |
aa140b76 | 2247 | |
3072d30e | 2248 | /* The bases are the same, just see if the offsets |
2249 | overlap. */ | |
48e1416a | 2250 | if ((offset < store_info->end) |
3072d30e | 2251 | && (offset + width > store_info->begin)) |
2252 | remove = true; | |
2253 | } | |
2254 | } | |
48e1416a | 2255 | |
2256 | /* else | |
3072d30e | 2257 | The else case that is missing here is that the |
2258 | bases are constant but different. There is nothing | |
2259 | to do here because there is no overlap. */ | |
48e1416a | 2260 | |
3072d30e | 2261 | if (remove) |
2262 | { | |
1ca59310 | 2263 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2264 | dump_insn_info ("removing from active", i_ptr); |
2265 | ||
1242bee6 | 2266 | active_local_stores_len--; |
3072d30e | 2267 | if (last) |
2268 | last->next_local_store = i_ptr->next_local_store; | |
2269 | else | |
2270 | active_local_stores = i_ptr->next_local_store; | |
2271 | } | |
2272 | else | |
2273 | last = i_ptr; | |
2274 | i_ptr = i_ptr->next_local_store; | |
2275 | } | |
2276 | } | |
48e1416a | 2277 | else |
3072d30e | 2278 | { |
2279 | insn_info_t i_ptr = active_local_stores; | |
2280 | insn_info_t last = NULL; | |
1ca59310 | 2281 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2282 | { |
2283 | fprintf (dump_file, " processing cselib load mem:"); | |
2284 | print_inline_rtx (dump_file, mem, 0); | |
2285 | fprintf (dump_file, "\n"); | |
2286 | } | |
2287 | ||
2288 | while (i_ptr) | |
2289 | { | |
2290 | bool remove = false; | |
c2eab334 | 2291 | store_info *store_info = i_ptr->store_rec; |
48e1416a | 2292 | |
1ca59310 | 2293 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2294 | fprintf (dump_file, " processing cselib load against insn %d\n", |
2295 | INSN_UID (i_ptr->insn)); | |
2296 | ||
2297 | /* Skip the clobbers. */ | |
2298 | while (!store_info->is_set) | |
2299 | store_info = store_info->next; | |
2300 | ||
2301 | /* If this read is just reading back something that we just | |
2302 | stored, rewrite the read. */ | |
2303 | if (store_info->rhs | |
2304 | && store_info->group_id == -1 | |
2305 | && store_info->cse_base == base | |
2ffe5515 | 2306 | && width != -1 |
aa140b76 | 2307 | && offset >= store_info->begin |
2308 | && offset + width <= store_info->end | |
2309 | && all_positions_needed_p (store_info, | |
2310 | offset - store_info->begin, width) | |
2311 | && replace_read (store_info, i_ptr, read_info, insn_info, loc, | |
2312 | bb_info->regs_live)) | |
ec1203cd | 2313 | return; |
3072d30e | 2314 | |
2315 | if (!store_info->alias_set) | |
48e1416a | 2316 | remove = canon_true_dependence (store_info->mem, |
3072d30e | 2317 | GET_MODE (store_info->mem), |
2318 | store_info->mem_addr, | |
376a287d | 2319 | mem, mem_addr); |
48e1416a | 2320 | |
3072d30e | 2321 | if (remove) |
2322 | { | |
1ca59310 | 2323 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2324 | dump_insn_info ("removing from active", i_ptr); |
48e1416a | 2325 | |
1242bee6 | 2326 | active_local_stores_len--; |
3072d30e | 2327 | if (last) |
2328 | last->next_local_store = i_ptr->next_local_store; | |
2329 | else | |
2330 | active_local_stores = i_ptr->next_local_store; | |
2331 | } | |
2332 | else | |
2333 | last = i_ptr; | |
2334 | i_ptr = i_ptr->next_local_store; | |
2335 | } | |
2336 | } | |
3072d30e | 2337 | } |
2338 | ||
ec1203cd | 2339 | /* A note_uses callback in which DATA points the INSN_INFO for |
3072d30e | 2340 | as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns |
2341 | true for any part of *LOC. */ | |
2342 | ||
2343 | static void | |
2344 | check_mem_read_use (rtx *loc, void *data) | |
2345 | { | |
ec1203cd | 2346 | subrtx_ptr_iterator::array_type array; |
2347 | FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST) | |
2348 | { | |
2349 | rtx *loc = *iter; | |
2350 | if (MEM_P (*loc)) | |
2351 | check_mem_read_rtx (loc, (bb_info_t) data); | |
2352 | } | |
3072d30e | 2353 | } |
2354 | ||
aa140b76 | 2355 | |
2356 | /* Get arguments passed to CALL_INSN. Return TRUE if successful. | |
2357 | So far it only handles arguments passed in registers. */ | |
2358 | ||
2359 | static bool | |
2360 | get_call_args (rtx call_insn, tree fn, rtx *args, int nargs) | |
2361 | { | |
39cba157 | 2362 | CUMULATIVE_ARGS args_so_far_v; |
2363 | cumulative_args_t args_so_far; | |
aa140b76 | 2364 | tree arg; |
2365 | int idx; | |
2366 | ||
39cba157 | 2367 | INIT_CUMULATIVE_ARGS (args_so_far_v, TREE_TYPE (fn), NULL_RTX, 0, 3); |
2368 | args_so_far = pack_cumulative_args (&args_so_far_v); | |
aa140b76 | 2369 | |
2370 | arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2371 | for (idx = 0; | |
2372 | arg != void_list_node && idx < nargs; | |
2373 | arg = TREE_CHAIN (arg), idx++) | |
2374 | { | |
3754d046 | 2375 | machine_mode mode = TYPE_MODE (TREE_VALUE (arg)); |
f387af4f | 2376 | rtx reg, link, tmp; |
39cba157 | 2377 | reg = targetm.calls.function_arg (args_so_far, mode, NULL_TREE, true); |
aa140b76 | 2378 | if (!reg || !REG_P (reg) || GET_MODE (reg) != mode |
2379 | || GET_MODE_CLASS (mode) != MODE_INT) | |
2380 | return false; | |
2381 | ||
2382 | for (link = CALL_INSN_FUNCTION_USAGE (call_insn); | |
2383 | link; | |
2384 | link = XEXP (link, 1)) | |
2385 | if (GET_CODE (XEXP (link, 0)) == USE) | |
2386 | { | |
2387 | args[idx] = XEXP (XEXP (link, 0), 0); | |
2388 | if (REG_P (args[idx]) | |
2389 | && REGNO (args[idx]) == REGNO (reg) | |
2390 | && (GET_MODE (args[idx]) == mode | |
2391 | || (GET_MODE_CLASS (GET_MODE (args[idx])) == MODE_INT | |
2392 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2393 | <= UNITS_PER_WORD) | |
2394 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2395 | > GET_MODE_SIZE (mode))))) | |
2396 | break; | |
2397 | } | |
2398 | if (!link) | |
2399 | return false; | |
2400 | ||
2401 | tmp = cselib_expand_value_rtx (args[idx], scratch, 5); | |
2402 | if (GET_MODE (args[idx]) != mode) | |
2403 | { | |
2404 | if (!tmp || !CONST_INT_P (tmp)) | |
2405 | return false; | |
f62058c3 | 2406 | tmp = gen_int_mode (INTVAL (tmp), mode); |
aa140b76 | 2407 | } |
2408 | if (tmp) | |
2409 | args[idx] = tmp; | |
2410 | ||
39cba157 | 2411 | targetm.calls.function_arg_advance (args_so_far, mode, NULL_TREE, true); |
aa140b76 | 2412 | } |
2413 | if (arg != void_list_node || idx != nargs) | |
2414 | return false; | |
2415 | return true; | |
2416 | } | |
2417 | ||
5a9ecd4a | 2418 | /* Return a bitmap of the fixed registers contained in IN. */ |
2419 | ||
2420 | static bitmap | |
2421 | copy_fixed_regs (const_bitmap in) | |
2422 | { | |
2423 | bitmap ret; | |
2424 | ||
2425 | ret = ALLOC_REG_SET (NULL); | |
2426 | bitmap_and (ret, in, fixed_reg_set_regset); | |
2427 | return ret; | |
2428 | } | |
aa140b76 | 2429 | |
3072d30e | 2430 | /* Apply record_store to all candidate stores in INSN. Mark INSN |
2431 | if some part of it is not a candidate store and assigns to a | |
2432 | non-register target. */ | |
2433 | ||
2434 | static void | |
ebabb7a3 | 2435 | scan_insn (bb_info_t bb_info, rtx_insn *insn) |
3072d30e | 2436 | { |
2437 | rtx body; | |
e16712b1 | 2438 | insn_info_type *insn_info = insn_info_type_pool.allocate (); |
3072d30e | 2439 | int mems_found = 0; |
55c5ac9f | 2440 | memset (insn_info, 0, sizeof (struct insn_info_type)); |
3072d30e | 2441 | |
1ca59310 | 2442 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2443 | fprintf (dump_file, "\n**scanning insn=%d\n", |
2444 | INSN_UID (insn)); | |
2445 | ||
2446 | insn_info->prev_insn = bb_info->last_insn; | |
2447 | insn_info->insn = insn; | |
2448 | bb_info->last_insn = insn_info; | |
48e1416a | 2449 | |
9845d120 | 2450 | if (DEBUG_INSN_P (insn)) |
2451 | { | |
2452 | insn_info->cannot_delete = true; | |
2453 | return; | |
2454 | } | |
3072d30e | 2455 | |
3072d30e | 2456 | /* Look at all of the uses in the insn. */ |
2457 | note_uses (&PATTERN (insn), check_mem_read_use, bb_info); | |
2458 | ||
2459 | if (CALL_P (insn)) | |
2460 | { | |
aa140b76 | 2461 | bool const_call; |
2462 | tree memset_call = NULL_TREE; | |
2463 | ||
3072d30e | 2464 | insn_info->cannot_delete = true; |
17e1318c | 2465 | |
3072d30e | 2466 | /* Const functions cannot do anything bad i.e. read memory, |
17e1318c | 2467 | however, they can read their parameters which may have |
aa140b76 | 2468 | been pushed onto the stack. |
2469 | memset and bzero don't read memory either. */ | |
2470 | const_call = RTL_CONST_CALL_P (insn); | |
2471 | if (!const_call) | |
2472 | { | |
cf7fb72d | 2473 | rtx call = get_call_rtx_from (insn); |
2474 | if (call && GET_CODE (XEXP (XEXP (call, 0), 0)) == SYMBOL_REF) | |
aa140b76 | 2475 | { |
2476 | rtx symbol = XEXP (XEXP (call, 0), 0); | |
2477 | if (SYMBOL_REF_DECL (symbol) | |
2478 | && TREE_CODE (SYMBOL_REF_DECL (symbol)) == FUNCTION_DECL) | |
2479 | { | |
2480 | if ((DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (symbol)) | |
2481 | == BUILT_IN_NORMAL | |
2482 | && (DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol)) | |
2483 | == BUILT_IN_MEMSET)) | |
2484 | || SYMBOL_REF_DECL (symbol) == block_clear_fn) | |
2485 | memset_call = SYMBOL_REF_DECL (symbol); | |
2486 | } | |
2487 | } | |
2488 | } | |
2489 | if (const_call || memset_call) | |
3072d30e | 2490 | { |
2491 | insn_info_t i_ptr = active_local_stores; | |
2492 | insn_info_t last = NULL; | |
2493 | ||
1ca59310 | 2494 | if (dump_file && (dump_flags & TDF_DETAILS)) |
aa140b76 | 2495 | fprintf (dump_file, "%s call %d\n", |
2496 | const_call ? "const" : "memset", INSN_UID (insn)); | |
3072d30e | 2497 | |
16bf64db | 2498 | /* See the head comment of the frame_read field. */ |
17853422 | 2499 | if (reload_completed |
2500 | /* Tail calls are storing their arguments using | |
2501 | arg pointer. If it is a frame pointer on the target, | |
2502 | even before reload we need to kill frame pointer based | |
2503 | stores. */ | |
2504 | || (SIBLING_CALL_P (insn) | |
2505 | && HARD_FRAME_POINTER_IS_ARG_POINTER)) | |
16bf64db | 2506 | insn_info->frame_read = true; |
2507 | ||
2508 | /* Loop over the active stores and remove those which are | |
2509 | killed by the const function call. */ | |
3072d30e | 2510 | while (i_ptr) |
2511 | { | |
16bf64db | 2512 | bool remove_store = false; |
2513 | ||
2514 | /* The stack pointer based stores are always killed. */ | |
17e1318c | 2515 | if (i_ptr->stack_pointer_based) |
16bf64db | 2516 | remove_store = true; |
2517 | ||
2518 | /* If the frame is read, the frame related stores are killed. */ | |
2519 | else if (insn_info->frame_read) | |
2520 | { | |
c2eab334 | 2521 | store_info *store_info = i_ptr->store_rec; |
16bf64db | 2522 | |
2523 | /* Skip the clobbers. */ | |
2524 | while (!store_info->is_set) | |
2525 | store_info = store_info->next; | |
2526 | ||
2527 | if (store_info->group_id >= 0 | |
f1f41a6c | 2528 | && rtx_group_vec[store_info->group_id]->frame_related) |
16bf64db | 2529 | remove_store = true; |
2530 | } | |
2531 | ||
2532 | if (remove_store) | |
3072d30e | 2533 | { |
1ca59310 | 2534 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2535 | dump_insn_info ("removing from active", i_ptr); |
48e1416a | 2536 | |
1242bee6 | 2537 | active_local_stores_len--; |
3072d30e | 2538 | if (last) |
2539 | last->next_local_store = i_ptr->next_local_store; | |
2540 | else | |
2541 | active_local_stores = i_ptr->next_local_store; | |
2542 | } | |
2543 | else | |
2544 | last = i_ptr; | |
16bf64db | 2545 | |
3072d30e | 2546 | i_ptr = i_ptr->next_local_store; |
2547 | } | |
aa140b76 | 2548 | |
2549 | if (memset_call) | |
2550 | { | |
2551 | rtx args[3]; | |
2552 | if (get_call_args (insn, memset_call, args, 3) | |
2553 | && CONST_INT_P (args[1]) | |
2554 | && CONST_INT_P (args[2]) | |
2555 | && INTVAL (args[2]) > 0) | |
2556 | { | |
2557 | rtx mem = gen_rtx_MEM (BLKmode, args[0]); | |
5b2a69fa | 2558 | set_mem_size (mem, INTVAL (args[2])); |
d1f9b275 | 2559 | body = gen_rtx_SET (mem, args[1]); |
aa140b76 | 2560 | mems_found += record_store (body, bb_info); |
1ca59310 | 2561 | if (dump_file && (dump_flags & TDF_DETAILS)) |
aa140b76 | 2562 | fprintf (dump_file, "handling memset as BLKmode store\n"); |
2563 | if (mems_found == 1) | |
2564 | { | |
1242bee6 | 2565 | if (active_local_stores_len++ |
2566 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2567 | { | |
2568 | active_local_stores_len = 1; | |
2569 | active_local_stores = NULL; | |
2570 | } | |
5a9ecd4a | 2571 | insn_info->fixed_regs_live |
2572 | = copy_fixed_regs (bb_info->regs_live); | |
aa140b76 | 2573 | insn_info->next_local_store = active_local_stores; |
2574 | active_local_stores = insn_info; | |
2575 | } | |
2576 | } | |
2577 | } | |
3072d30e | 2578 | } |
17853422 | 2579 | else if (SIBLING_CALL_P (insn) && reload_completed) |
2580 | /* Arguments for a sibling call that are pushed to memory are passed | |
2581 | using the incoming argument pointer of the current function. After | |
2582 | reload that might be (and likely is) frame pointer based. */ | |
2583 | add_wild_read (bb_info); | |
17e1318c | 2584 | else |
b4a708fb | 2585 | /* Every other call, including pure functions, may read any memory |
2586 | that is not relative to the frame. */ | |
2587 | add_non_frame_wild_read (bb_info); | |
17e1318c | 2588 | |
3072d30e | 2589 | return; |
2590 | } | |
2591 | ||
2592 | /* Assuming that there are sets in these insns, we cannot delete | |
2593 | them. */ | |
2594 | if ((GET_CODE (PATTERN (insn)) == CLOBBER) | |
4aafe72f | 2595 | || volatile_refs_p (PATTERN (insn)) |
bc0dfc8d | 2596 | || (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) |
3072d30e | 2597 | || (RTX_FRAME_RELATED_P (insn)) |
2598 | || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX)) | |
2599 | insn_info->cannot_delete = true; | |
48e1416a | 2600 | |
3072d30e | 2601 | body = PATTERN (insn); |
2602 | if (GET_CODE (body) == PARALLEL) | |
2603 | { | |
2604 | int i; | |
2605 | for (i = 0; i < XVECLEN (body, 0); i++) | |
2606 | mems_found += record_store (XVECEXP (body, 0, i), bb_info); | |
2607 | } | |
2608 | else | |
2609 | mems_found += record_store (body, bb_info); | |
2610 | ||
1ca59310 | 2611 | if (dump_file && (dump_flags & TDF_DETAILS)) |
48e1416a | 2612 | fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n", |
3072d30e | 2613 | mems_found, insn_info->cannot_delete ? "true" : "false"); |
2614 | ||
aa140b76 | 2615 | /* If we found some sets of mems, add it into the active_local_stores so |
2616 | that it can be locally deleted if found dead or used for | |
2617 | replace_read and redundant constant store elimination. Otherwise mark | |
2618 | it as cannot delete. This simplifies the processing later. */ | |
2619 | if (mems_found == 1) | |
3072d30e | 2620 | { |
1242bee6 | 2621 | if (active_local_stores_len++ |
2622 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2623 | { | |
2624 | active_local_stores_len = 1; | |
2625 | active_local_stores = NULL; | |
2626 | } | |
5a9ecd4a | 2627 | insn_info->fixed_regs_live = copy_fixed_regs (bb_info->regs_live); |
3072d30e | 2628 | insn_info->next_local_store = active_local_stores; |
2629 | active_local_stores = insn_info; | |
2630 | } | |
2631 | else | |
2632 | insn_info->cannot_delete = true; | |
2633 | } | |
2634 | ||
2635 | ||
2636 | /* Remove BASE from the set of active_local_stores. This is a | |
2637 | callback from cselib that is used to get rid of the stores in | |
2638 | active_local_stores. */ | |
2639 | ||
2640 | static void | |
2641 | remove_useless_values (cselib_val *base) | |
2642 | { | |
2643 | insn_info_t insn_info = active_local_stores; | |
2644 | insn_info_t last = NULL; | |
2645 | ||
2646 | while (insn_info) | |
2647 | { | |
c2eab334 | 2648 | store_info *store_info = insn_info->store_rec; |
9ce37fa7 | 2649 | bool del = false; |
3072d30e | 2650 | |
2651 | /* If ANY of the store_infos match the cselib group that is | |
2652 | being deleted, then the insn can not be deleted. */ | |
2653 | while (store_info) | |
2654 | { | |
48e1416a | 2655 | if ((store_info->group_id == -1) |
3072d30e | 2656 | && (store_info->cse_base == base)) |
2657 | { | |
9ce37fa7 | 2658 | del = true; |
3072d30e | 2659 | break; |
2660 | } | |
2661 | store_info = store_info->next; | |
2662 | } | |
2663 | ||
9ce37fa7 | 2664 | if (del) |
3072d30e | 2665 | { |
1242bee6 | 2666 | active_local_stores_len--; |
3072d30e | 2667 | if (last) |
2668 | last->next_local_store = insn_info->next_local_store; | |
2669 | else | |
2670 | active_local_stores = insn_info->next_local_store; | |
2671 | free_store_info (insn_info); | |
2672 | } | |
2673 | else | |
2674 | last = insn_info; | |
48e1416a | 2675 | |
3072d30e | 2676 | insn_info = insn_info->next_local_store; |
2677 | } | |
2678 | } | |
2679 | ||
2680 | ||
2681 | /* Do all of step 1. */ | |
2682 | ||
2683 | static void | |
2684 | dse_step1 (void) | |
2685 | { | |
2686 | basic_block bb; | |
4fb07d00 | 2687 | bitmap regs_live = BITMAP_ALLOC (®_obstack); |
48e1416a | 2688 | |
35af0188 | 2689 | cselib_init (0); |
3072d30e | 2690 | all_blocks = BITMAP_ALLOC (NULL); |
2691 | bitmap_set_bit (all_blocks, ENTRY_BLOCK); | |
2692 | bitmap_set_bit (all_blocks, EXIT_BLOCK); | |
2693 | ||
ed7d889a | 2694 | FOR_ALL_BB_FN (bb, cfun) |
3072d30e | 2695 | { |
2696 | insn_info_t ptr; | |
e16712b1 | 2697 | bb_info_t bb_info = dse_bb_info_type_pool.allocate (); |
3072d30e | 2698 | |
55c5ac9f | 2699 | memset (bb_info, 0, sizeof (dse_bb_info_type)); |
3072d30e | 2700 | bitmap_set_bit (all_blocks, bb->index); |
a1b0a968 | 2701 | bb_info->regs_live = regs_live; |
2702 | ||
2703 | bitmap_copy (regs_live, DF_LR_IN (bb)); | |
2704 | df_simulate_initialize_forwards (bb, regs_live); | |
3072d30e | 2705 | |
2706 | bb_table[bb->index] = bb_info; | |
2707 | cselib_discard_hook = remove_useless_values; | |
2708 | ||
2709 | if (bb->index >= NUM_FIXED_BLOCKS) | |
2710 | { | |
ebabb7a3 | 2711 | rtx_insn *insn; |
3072d30e | 2712 | |
3072d30e | 2713 | active_local_stores = NULL; |
1242bee6 | 2714 | active_local_stores_len = 0; |
3072d30e | 2715 | cselib_clear_table (); |
48e1416a | 2716 | |
3072d30e | 2717 | /* Scan the insns. */ |
2718 | FOR_BB_INSNS (bb, insn) | |
2719 | { | |
2720 | if (INSN_P (insn)) | |
2721 | scan_insn (bb_info, insn); | |
2722 | cselib_process_insn (insn); | |
a1b0a968 | 2723 | if (INSN_P (insn)) |
2724 | df_simulate_one_insn_forwards (bb, insn, regs_live); | |
3072d30e | 2725 | } |
48e1416a | 2726 | |
3072d30e | 2727 | /* This is something of a hack, because the global algorithm |
2728 | is supposed to take care of the case where stores go dead | |
2729 | at the end of the function. However, the global | |
2730 | algorithm must take a more conservative view of block | |
2731 | mode reads than the local alg does. So to get the case | |
2732 | where you have a store to the frame followed by a non | |
bef304b8 | 2733 | overlapping block more read, we look at the active local |
3072d30e | 2734 | stores at the end of the function and delete all of the |
2735 | frame and spill based ones. */ | |
2736 | if (stores_off_frame_dead_at_return | |
2737 | && (EDGE_COUNT (bb->succs) == 0 | |
2738 | || (single_succ_p (bb) | |
34154e27 | 2739 | && single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (cfun) |
18d50ae6 | 2740 | && ! crtl->calls_eh_return))) |
3072d30e | 2741 | { |
2742 | insn_info_t i_ptr = active_local_stores; | |
2743 | while (i_ptr) | |
2744 | { | |
c2eab334 | 2745 | store_info *store_info = i_ptr->store_rec; |
3072d30e | 2746 | |
2747 | /* Skip the clobbers. */ | |
2748 | while (!store_info->is_set) | |
2749 | store_info = store_info->next; | |
aa140b76 | 2750 | if (store_info->alias_set && !i_ptr->cannot_delete) |
3072d30e | 2751 | delete_dead_store_insn (i_ptr); |
48e1416a | 2752 | else |
3072d30e | 2753 | if (store_info->group_id >= 0) |
2754 | { | |
c2eab334 | 2755 | group_info *group |
f1f41a6c | 2756 | = rtx_group_vec[store_info->group_id]; |
aa140b76 | 2757 | if (group->frame_related && !i_ptr->cannot_delete) |
3072d30e | 2758 | delete_dead_store_insn (i_ptr); |
2759 | } | |
2760 | ||
2761 | i_ptr = i_ptr->next_local_store; | |
2762 | } | |
2763 | } | |
2764 | ||
2765 | /* Get rid of the loads that were discovered in | |
2766 | replace_read. Cselib is finished with this block. */ | |
2767 | while (deferred_change_list) | |
2768 | { | |
c2eab334 | 2769 | deferred_change *next = deferred_change_list->next; |
3072d30e | 2770 | |
2771 | /* There is no reason to validate this change. That was | |
2772 | done earlier. */ | |
2773 | *deferred_change_list->loc = deferred_change_list->reg; | |
e16712b1 | 2774 | deferred_change_pool.remove (deferred_change_list); |
3072d30e | 2775 | deferred_change_list = next; |
2776 | } | |
2777 | ||
2778 | /* Get rid of all of the cselib based store_infos in this | |
2779 | block and mark the containing insns as not being | |
2780 | deletable. */ | |
2781 | ptr = bb_info->last_insn; | |
2782 | while (ptr) | |
2783 | { | |
2784 | if (ptr->contains_cselib_groups) | |
aa140b76 | 2785 | { |
c2eab334 | 2786 | store_info *s_info = ptr->store_rec; |
aa140b76 | 2787 | while (s_info && !s_info->is_set) |
2788 | s_info = s_info->next; | |
2789 | if (s_info | |
2790 | && s_info->redundant_reason | |
2791 | && s_info->redundant_reason->insn | |
2792 | && !ptr->cannot_delete) | |
2793 | { | |
1ca59310 | 2794 | if (dump_file && (dump_flags & TDF_DETAILS)) |
aa140b76 | 2795 | fprintf (dump_file, "Locally deleting insn %d " |
2796 | "because insn %d stores the " | |
2797 | "same value and couldn't be " | |
2798 | "eliminated\n", | |
2799 | INSN_UID (ptr->insn), | |
2800 | INSN_UID (s_info->redundant_reason->insn)); | |
2801 | delete_dead_store_insn (ptr); | |
2802 | } | |
aa140b76 | 2803 | free_store_info (ptr); |
2804 | } | |
2805 | else | |
2806 | { | |
c2eab334 | 2807 | store_info *s_info; |
aa140b76 | 2808 | |
2809 | /* Free at least positions_needed bitmaps. */ | |
2810 | for (s_info = ptr->store_rec; s_info; s_info = s_info->next) | |
2811 | if (s_info->is_large) | |
2812 | { | |
843bd2fa | 2813 | BITMAP_FREE (s_info->positions_needed.large.bmap); |
aa140b76 | 2814 | s_info->is_large = false; |
2815 | } | |
2816 | } | |
3072d30e | 2817 | ptr = ptr->prev_insn; |
2818 | } | |
2819 | ||
55c5ac9f | 2820 | cse_store_info_pool.release (); |
3072d30e | 2821 | } |
a1b0a968 | 2822 | bb_info->regs_live = NULL; |
3072d30e | 2823 | } |
2824 | ||
a1b0a968 | 2825 | BITMAP_FREE (regs_live); |
3072d30e | 2826 | cselib_finish (); |
c1f445d2 | 2827 | rtx_group_table->empty (); |
3072d30e | 2828 | } |
2829 | ||
2830 | \f | |
2831 | /*---------------------------------------------------------------------------- | |
2832 | Second step. | |
2833 | ||
2834 | Assign each byte position in the stores that we are going to | |
2835 | analyze globally to a position in the bitmaps. Returns true if | |
6dfdc153 | 2836 | there are any bit positions assigned. |
3072d30e | 2837 | ----------------------------------------------------------------------------*/ |
2838 | ||
2839 | static void | |
2840 | dse_step2_init (void) | |
2841 | { | |
2842 | unsigned int i; | |
c2eab334 | 2843 | group_info *group; |
3072d30e | 2844 | |
f1f41a6c | 2845 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
3072d30e | 2846 | { |
2847 | /* For all non stack related bases, we only consider a store to | |
2848 | be deletable if there are two or more stores for that | |
2849 | position. This is because it takes one store to make the | |
2850 | other store redundant. However, for the stores that are | |
2851 | stack related, we consider them if there is only one store | |
2852 | for the position. We do this because the stack related | |
2853 | stores can be deleted if their is no read between them and | |
2854 | the end of the function. | |
48e1416a | 2855 | |
3072d30e | 2856 | To make this work in the current framework, we take the stack |
2857 | related bases add all of the bits from store1 into store2. | |
2858 | This has the effect of making the eligible even if there is | |
2859 | only one store. */ | |
2860 | ||
2861 | if (stores_off_frame_dead_at_return && group->frame_related) | |
2862 | { | |
2863 | bitmap_ior_into (group->store2_n, group->store1_n); | |
2864 | bitmap_ior_into (group->store2_p, group->store1_p); | |
1ca59310 | 2865 | if (dump_file && (dump_flags & TDF_DETAILS)) |
48e1416a | 2866 | fprintf (dump_file, "group %d is frame related ", i); |
3072d30e | 2867 | } |
2868 | ||
2869 | group->offset_map_size_n++; | |
4fb07d00 | 2870 | group->offset_map_n = XOBNEWVEC (&dse_obstack, int, |
2871 | group->offset_map_size_n); | |
3072d30e | 2872 | group->offset_map_size_p++; |
4fb07d00 | 2873 | group->offset_map_p = XOBNEWVEC (&dse_obstack, int, |
2874 | group->offset_map_size_p); | |
3072d30e | 2875 | group->process_globally = false; |
1ca59310 | 2876 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 2877 | { |
48e1416a | 2878 | fprintf (dump_file, "group %d(%d+%d): ", i, |
3072d30e | 2879 | (int)bitmap_count_bits (group->store2_n), |
2880 | (int)bitmap_count_bits (group->store2_p)); | |
2881 | bitmap_print (dump_file, group->store2_n, "n ", " "); | |
2882 | bitmap_print (dump_file, group->store2_p, "p ", "\n"); | |
2883 | } | |
2884 | } | |
2885 | } | |
2886 | ||
2887 | ||
2888 | /* Init the offset tables for the normal case. */ | |
2889 | ||
2890 | static bool | |
2891 | dse_step2_nospill (void) | |
2892 | { | |
2893 | unsigned int i; | |
c2eab334 | 2894 | group_info *group; |
3072d30e | 2895 | /* Position 0 is unused because 0 is used in the maps to mean |
2896 | unused. */ | |
2897 | current_position = 1; | |
f1f41a6c | 2898 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
3072d30e | 2899 | { |
2900 | bitmap_iterator bi; | |
2901 | unsigned int j; | |
2902 | ||
2903 | if (group == clear_alias_group) | |
2904 | continue; | |
2905 | ||
9af5ce0c | 2906 | memset (group->offset_map_n, 0, sizeof (int) * group->offset_map_size_n); |
2907 | memset (group->offset_map_p, 0, sizeof (int) * group->offset_map_size_p); | |
3072d30e | 2908 | bitmap_clear (group->group_kill); |
2909 | ||
2910 | EXECUTE_IF_SET_IN_BITMAP (group->store2_n, 0, j, bi) | |
2911 | { | |
2912 | bitmap_set_bit (group->group_kill, current_position); | |
b4a708fb | 2913 | if (bitmap_bit_p (group->escaped_n, j)) |
2914 | bitmap_set_bit (kill_on_calls, current_position); | |
3072d30e | 2915 | group->offset_map_n[j] = current_position++; |
2916 | group->process_globally = true; | |
2917 | } | |
2918 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2919 | { | |
48e1416a | 2920 | bitmap_set_bit (group->group_kill, current_position); |
b4a708fb | 2921 | if (bitmap_bit_p (group->escaped_p, j)) |
2922 | bitmap_set_bit (kill_on_calls, current_position); | |
3072d30e | 2923 | group->offset_map_p[j] = current_position++; |
2924 | group->process_globally = true; | |
2925 | } | |
2926 | } | |
2927 | return current_position != 1; | |
2928 | } | |
2929 | ||
2930 | ||
3072d30e | 2931 | \f |
2932 | /*---------------------------------------------------------------------------- | |
2933 | Third step. | |
48e1416a | 2934 | |
3072d30e | 2935 | Build the bit vectors for the transfer functions. |
2936 | ----------------------------------------------------------------------------*/ | |
2937 | ||
2938 | ||
3072d30e | 2939 | /* Look up the bitmap index for OFFSET in GROUP_INFO. If it is not |
2940 | there, return 0. */ | |
2941 | ||
2942 | static int | |
c2eab334 | 2943 | get_bitmap_index (group_info *group_info, HOST_WIDE_INT offset) |
3072d30e | 2944 | { |
2945 | if (offset < 0) | |
2946 | { | |
2947 | HOST_WIDE_INT offset_p = -offset; | |
2948 | if (offset_p >= group_info->offset_map_size_n) | |
2949 | return 0; | |
2950 | return group_info->offset_map_n[offset_p]; | |
2951 | } | |
2952 | else | |
2953 | { | |
2954 | if (offset >= group_info->offset_map_size_p) | |
2955 | return 0; | |
2956 | return group_info->offset_map_p[offset]; | |
2957 | } | |
2958 | } | |
2959 | ||
2960 | ||
2961 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
2962 | may be NULL. */ | |
2963 | ||
48e1416a | 2964 | static void |
c2eab334 | 2965 | scan_stores_nospill (store_info *store_info, bitmap gen, bitmap kill) |
3072d30e | 2966 | { |
2967 | while (store_info) | |
2968 | { | |
2969 | HOST_WIDE_INT i; | |
c2eab334 | 2970 | group_info *group_info |
f1f41a6c | 2971 | = rtx_group_vec[store_info->group_id]; |
3072d30e | 2972 | if (group_info->process_globally) |
2973 | for (i = store_info->begin; i < store_info->end; i++) | |
2974 | { | |
2975 | int index = get_bitmap_index (group_info, i); | |
2976 | if (index != 0) | |
2977 | { | |
2978 | bitmap_set_bit (gen, index); | |
2979 | if (kill) | |
2980 | bitmap_clear_bit (kill, index); | |
2981 | } | |
2982 | } | |
2983 | store_info = store_info->next; | |
2984 | } | |
2985 | } | |
2986 | ||
2987 | ||
2988 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
2989 | may be NULL. */ | |
2990 | ||
48e1416a | 2991 | static void |
c2eab334 | 2992 | scan_stores_spill (store_info *store_info, bitmap gen, bitmap kill) |
3072d30e | 2993 | { |
2994 | while (store_info) | |
2995 | { | |
2996 | if (store_info->alias_set) | |
2997 | { | |
48e1416a | 2998 | int index = get_bitmap_index (clear_alias_group, |
3072d30e | 2999 | store_info->alias_set); |
3000 | if (index != 0) | |
3001 | { | |
3002 | bitmap_set_bit (gen, index); | |
3003 | if (kill) | |
3004 | bitmap_clear_bit (kill, index); | |
3005 | } | |
3006 | } | |
3007 | store_info = store_info->next; | |
3008 | } | |
3009 | } | |
3010 | ||
3011 | ||
3012 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3013 | may be NULL. */ | |
3014 | ||
3015 | static void | |
3016 | scan_reads_nospill (insn_info_t insn_info, bitmap gen, bitmap kill) | |
3017 | { | |
3018 | read_info_t read_info = insn_info->read_rec; | |
3019 | int i; | |
c2eab334 | 3020 | group_info *group; |
3072d30e | 3021 | |
16bf64db | 3022 | /* If this insn reads the frame, kill all the frame related stores. */ |
3023 | if (insn_info->frame_read) | |
3024 | { | |
f1f41a6c | 3025 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
16bf64db | 3026 | if (group->process_globally && group->frame_related) |
3027 | { | |
3028 | if (kill) | |
3029 | bitmap_ior_into (kill, group->group_kill); | |
48e1416a | 3030 | bitmap_and_compl_into (gen, group->group_kill); |
16bf64db | 3031 | } |
3032 | } | |
b4a708fb | 3033 | if (insn_info->non_frame_wild_read) |
3034 | { | |
3035 | /* Kill all non-frame related stores. Kill all stores of variables that | |
3036 | escape. */ | |
3037 | if (kill) | |
3038 | bitmap_ior_into (kill, kill_on_calls); | |
3039 | bitmap_and_compl_into (gen, kill_on_calls); | |
f1f41a6c | 3040 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
b4a708fb | 3041 | if (group->process_globally && !group->frame_related) |
3042 | { | |
3043 | if (kill) | |
3044 | bitmap_ior_into (kill, group->group_kill); | |
3045 | bitmap_and_compl_into (gen, group->group_kill); | |
3046 | } | |
3047 | } | |
3072d30e | 3048 | while (read_info) |
3049 | { | |
f1f41a6c | 3050 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
3072d30e | 3051 | { |
3052 | if (group->process_globally) | |
3053 | { | |
3054 | if (i == read_info->group_id) | |
3055 | { | |
3056 | if (read_info->begin > read_info->end) | |
3057 | { | |
3058 | /* Begin > end for block mode reads. */ | |
3059 | if (kill) | |
3060 | bitmap_ior_into (kill, group->group_kill); | |
3061 | bitmap_and_compl_into (gen, group->group_kill); | |
3062 | } | |
3063 | else | |
3064 | { | |
3065 | /* The groups are the same, just process the | |
3066 | offsets. */ | |
3067 | HOST_WIDE_INT j; | |
3068 | for (j = read_info->begin; j < read_info->end; j++) | |
3069 | { | |
3070 | int index = get_bitmap_index (group, j); | |
3071 | if (index != 0) | |
3072 | { | |
3073 | if (kill) | |
3074 | bitmap_set_bit (kill, index); | |
3075 | bitmap_clear_bit (gen, index); | |
3076 | } | |
3077 | } | |
3078 | } | |
3079 | } | |
3080 | else | |
3081 | { | |
3082 | /* The groups are different, if the alias sets | |
3083 | conflict, clear the entire group. We only need | |
3084 | to apply this test if the read_info is a cselib | |
3085 | read. Anything with a constant base cannot alias | |
3086 | something else with a different constant | |
3087 | base. */ | |
3088 | if ((read_info->group_id < 0) | |
48e1416a | 3089 | && canon_true_dependence (group->base_mem, |
ec410bf1 | 3090 | GET_MODE (group->base_mem), |
82d2c88b | 3091 | group->canon_base_addr, |
376a287d | 3092 | read_info->mem, NULL_RTX)) |
3072d30e | 3093 | { |
3094 | if (kill) | |
3095 | bitmap_ior_into (kill, group->group_kill); | |
3096 | bitmap_and_compl_into (gen, group->group_kill); | |
3097 | } | |
3098 | } | |
3099 | } | |
3100 | } | |
48e1416a | 3101 | |
3072d30e | 3102 | read_info = read_info->next; |
3103 | } | |
3104 | } | |
3105 | ||
3106 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3107 | may be NULL. */ | |
3108 | ||
3109 | static void | |
3110 | scan_reads_spill (read_info_t read_info, bitmap gen, bitmap kill) | |
3111 | { | |
3112 | while (read_info) | |
3113 | { | |
3114 | if (read_info->alias_set) | |
3115 | { | |
48e1416a | 3116 | int index = get_bitmap_index (clear_alias_group, |
3072d30e | 3117 | read_info->alias_set); |
3118 | if (index != 0) | |
3119 | { | |
3120 | if (kill) | |
3121 | bitmap_set_bit (kill, index); | |
3122 | bitmap_clear_bit (gen, index); | |
3123 | } | |
3124 | } | |
48e1416a | 3125 | |
3072d30e | 3126 | read_info = read_info->next; |
3127 | } | |
3128 | } | |
3129 | ||
3130 | ||
3131 | /* Return the insn in BB_INFO before the first wild read or if there | |
3132 | are no wild reads in the block, return the last insn. */ | |
3133 | ||
3134 | static insn_info_t | |
3135 | find_insn_before_first_wild_read (bb_info_t bb_info) | |
3136 | { | |
3137 | insn_info_t insn_info = bb_info->last_insn; | |
3138 | insn_info_t last_wild_read = NULL; | |
3139 | ||
3140 | while (insn_info) | |
3141 | { | |
3142 | if (insn_info->wild_read) | |
3143 | { | |
3144 | last_wild_read = insn_info->prev_insn; | |
3145 | /* Block starts with wild read. */ | |
3146 | if (!last_wild_read) | |
3147 | return NULL; | |
3148 | } | |
3149 | ||
3150 | insn_info = insn_info->prev_insn; | |
3151 | } | |
3152 | ||
3153 | if (last_wild_read) | |
3154 | return last_wild_read; | |
3155 | else | |
3156 | return bb_info->last_insn; | |
3157 | } | |
3158 | ||
3159 | ||
3160 | /* Scan the insns in BB_INFO starting at PTR and going to the top of | |
3161 | the block in order to build the gen and kill sets for the block. | |
3162 | We start at ptr which may be the last insn in the block or may be | |
3163 | the first insn with a wild read. In the latter case we are able to | |
3164 | skip the rest of the block because it just does not matter: | |
3165 | anything that happens is hidden by the wild read. */ | |
3166 | ||
3167 | static void | |
3168 | dse_step3_scan (bool for_spills, basic_block bb) | |
3169 | { | |
3170 | bb_info_t bb_info = bb_table[bb->index]; | |
3171 | insn_info_t insn_info; | |
3172 | ||
3173 | if (for_spills) | |
3174 | /* There are no wild reads in the spill case. */ | |
3175 | insn_info = bb_info->last_insn; | |
3176 | else | |
3177 | insn_info = find_insn_before_first_wild_read (bb_info); | |
48e1416a | 3178 | |
3072d30e | 3179 | /* In the spill case or in the no_spill case if there is no wild |
3180 | read in the block, we will need a kill set. */ | |
3181 | if (insn_info == bb_info->last_insn) | |
3182 | { | |
3183 | if (bb_info->kill) | |
3184 | bitmap_clear (bb_info->kill); | |
3185 | else | |
4fb07d00 | 3186 | bb_info->kill = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3187 | } |
48e1416a | 3188 | else |
3072d30e | 3189 | if (bb_info->kill) |
3190 | BITMAP_FREE (bb_info->kill); | |
3191 | ||
3192 | while (insn_info) | |
3193 | { | |
3194 | /* There may have been code deleted by the dce pass run before | |
3195 | this phase. */ | |
3196 | if (insn_info->insn && INSN_P (insn_info->insn)) | |
3197 | { | |
48e1416a | 3198 | /* Process the read(s) last. */ |
3072d30e | 3199 | if (for_spills) |
3200 | { | |
3201 | scan_stores_spill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3202 | scan_reads_spill (insn_info->read_rec, bb_info->gen, bb_info->kill); | |
3203 | } | |
3204 | else | |
3205 | { | |
3206 | scan_stores_nospill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3207 | scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill); | |
3208 | } | |
48e1416a | 3209 | } |
3072d30e | 3210 | |
3211 | insn_info = insn_info->prev_insn; | |
3212 | } | |
3213 | } | |
3214 | ||
3215 | ||
3216 | /* Set the gen set of the exit block, and also any block with no | |
3217 | successors that does not have a wild read. */ | |
3218 | ||
3219 | static void | |
3220 | dse_step3_exit_block_scan (bb_info_t bb_info) | |
3221 | { | |
3222 | /* The gen set is all 0's for the exit block except for the | |
3223 | frame_pointer_group. */ | |
48e1416a | 3224 | |
3072d30e | 3225 | if (stores_off_frame_dead_at_return) |
3226 | { | |
3227 | unsigned int i; | |
c2eab334 | 3228 | group_info *group; |
48e1416a | 3229 | |
f1f41a6c | 3230 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
3072d30e | 3231 | { |
3232 | if (group->process_globally && group->frame_related) | |
3233 | bitmap_ior_into (bb_info->gen, group->group_kill); | |
3234 | } | |
3235 | } | |
3236 | } | |
3237 | ||
3238 | ||
3239 | /* Find all of the blocks that are not backwards reachable from the | |
3240 | exit block or any block with no successors (BB). These are the | |
3241 | infinite loops or infinite self loops. These blocks will still | |
3242 | have their bits set in UNREACHABLE_BLOCKS. */ | |
3243 | ||
3244 | static void | |
3245 | mark_reachable_blocks (sbitmap unreachable_blocks, basic_block bb) | |
3246 | { | |
3247 | edge e; | |
3248 | edge_iterator ei; | |
3249 | ||
08b7917c | 3250 | if (bitmap_bit_p (unreachable_blocks, bb->index)) |
3072d30e | 3251 | { |
08b7917c | 3252 | bitmap_clear_bit (unreachable_blocks, bb->index); |
3072d30e | 3253 | FOR_EACH_EDGE (e, ei, bb->preds) |
48e1416a | 3254 | { |
3072d30e | 3255 | mark_reachable_blocks (unreachable_blocks, e->src); |
48e1416a | 3256 | } |
3072d30e | 3257 | } |
3258 | } | |
3259 | ||
3260 | /* Build the transfer functions for the function. */ | |
3261 | ||
3262 | static void | |
3263 | dse_step3 (bool for_spills) | |
3264 | { | |
3265 | basic_block bb; | |
fe672ac0 | 3266 | sbitmap unreachable_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
3072d30e | 3267 | sbitmap_iterator sbi; |
3268 | bitmap all_ones = NULL; | |
3269 | unsigned int i; | |
48e1416a | 3270 | |
53c5d9d4 | 3271 | bitmap_ones (unreachable_blocks); |
3072d30e | 3272 | |
ed7d889a | 3273 | FOR_ALL_BB_FN (bb, cfun) |
3072d30e | 3274 | { |
3275 | bb_info_t bb_info = bb_table[bb->index]; | |
3276 | if (bb_info->gen) | |
3277 | bitmap_clear (bb_info->gen); | |
3278 | else | |
4fb07d00 | 3279 | bb_info->gen = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3280 | |
3281 | if (bb->index == ENTRY_BLOCK) | |
3282 | ; | |
3283 | else if (bb->index == EXIT_BLOCK) | |
3284 | dse_step3_exit_block_scan (bb_info); | |
3285 | else | |
3286 | dse_step3_scan (for_spills, bb); | |
3287 | if (EDGE_COUNT (bb->succs) == 0) | |
3288 | mark_reachable_blocks (unreachable_blocks, bb); | |
3289 | ||
3290 | /* If this is the second time dataflow is run, delete the old | |
3291 | sets. */ | |
3292 | if (bb_info->in) | |
3293 | BITMAP_FREE (bb_info->in); | |
3294 | if (bb_info->out) | |
3295 | BITMAP_FREE (bb_info->out); | |
3296 | } | |
3297 | ||
3298 | /* For any block in an infinite loop, we must initialize the out set | |
3299 | to all ones. This could be expensive, but almost never occurs in | |
3300 | practice. However, it is common in regression tests. */ | |
0d211963 | 3301 | EXECUTE_IF_SET_IN_BITMAP (unreachable_blocks, 0, i, sbi) |
3072d30e | 3302 | { |
3303 | if (bitmap_bit_p (all_blocks, i)) | |
3304 | { | |
3305 | bb_info_t bb_info = bb_table[i]; | |
3306 | if (!all_ones) | |
3307 | { | |
3308 | unsigned int j; | |
c2eab334 | 3309 | group_info *group; |
3072d30e | 3310 | |
4fb07d00 | 3311 | all_ones = BITMAP_ALLOC (&dse_bitmap_obstack); |
f1f41a6c | 3312 | FOR_EACH_VEC_ELT (rtx_group_vec, j, group) |
3072d30e | 3313 | bitmap_ior_into (all_ones, group->group_kill); |
3314 | } | |
3315 | if (!bb_info->out) | |
3316 | { | |
4fb07d00 | 3317 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3318 | bitmap_copy (bb_info->out, all_ones); |
3319 | } | |
3320 | } | |
3321 | } | |
3322 | ||
3323 | if (all_ones) | |
3324 | BITMAP_FREE (all_ones); | |
3325 | sbitmap_free (unreachable_blocks); | |
3326 | } | |
3327 | ||
3328 | ||
3329 | \f | |
3330 | /*---------------------------------------------------------------------------- | |
3331 | Fourth step. | |
3332 | ||
3333 | Solve the bitvector equations. | |
3334 | ----------------------------------------------------------------------------*/ | |
3335 | ||
3336 | ||
3337 | /* Confluence function for blocks with no successors. Create an out | |
3338 | set from the gen set of the exit block. This block logically has | |
3339 | the exit block as a successor. */ | |
3340 | ||
3341 | ||
3342 | ||
3343 | static void | |
3344 | dse_confluence_0 (basic_block bb) | |
3345 | { | |
3346 | bb_info_t bb_info = bb_table[bb->index]; | |
3347 | ||
3348 | if (bb->index == EXIT_BLOCK) | |
3349 | return; | |
3350 | ||
3351 | if (!bb_info->out) | |
3352 | { | |
4fb07d00 | 3353 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3354 | bitmap_copy (bb_info->out, bb_table[EXIT_BLOCK]->gen); |
3355 | } | |
3356 | } | |
3357 | ||
3358 | /* Propagate the information from the in set of the dest of E to the | |
3359 | out set of the src of E. If the various in or out sets are not | |
3360 | there, that means they are all ones. */ | |
3361 | ||
a703ca31 | 3362 | static bool |
3072d30e | 3363 | dse_confluence_n (edge e) |
3364 | { | |
3365 | bb_info_t src_info = bb_table[e->src->index]; | |
3366 | bb_info_t dest_info = bb_table[e->dest->index]; | |
3367 | ||
3368 | if (dest_info->in) | |
3369 | { | |
3370 | if (src_info->out) | |
3371 | bitmap_and_into (src_info->out, dest_info->in); | |
3372 | else | |
3373 | { | |
4fb07d00 | 3374 | src_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3375 | bitmap_copy (src_info->out, dest_info->in); |
3376 | } | |
3377 | } | |
a703ca31 | 3378 | return true; |
3072d30e | 3379 | } |
3380 | ||
3381 | ||
3382 | /* Propagate the info from the out to the in set of BB_INDEX's basic | |
48e1416a | 3383 | block. There are three cases: |
3072d30e | 3384 | |
3385 | 1) The block has no kill set. In this case the kill set is all | |
3386 | ones. It does not matter what the out set of the block is, none of | |
3387 | the info can reach the top. The only thing that reaches the top is | |
3388 | the gen set and we just copy the set. | |
3389 | ||
3390 | 2) There is a kill set but no out set and bb has successors. In | |
3391 | this case we just return. Eventually an out set will be created and | |
3392 | it is better to wait than to create a set of ones. | |
3393 | ||
3394 | 3) There is both a kill and out set. We apply the obvious transfer | |
3395 | function. | |
3396 | */ | |
3397 | ||
3398 | static bool | |
3399 | dse_transfer_function (int bb_index) | |
3400 | { | |
3401 | bb_info_t bb_info = bb_table[bb_index]; | |
3402 | ||
3403 | if (bb_info->kill) | |
3404 | { | |
3405 | if (bb_info->out) | |
3406 | { | |
3407 | /* Case 3 above. */ | |
3408 | if (bb_info->in) | |
48e1416a | 3409 | return bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
3072d30e | 3410 | bb_info->out, bb_info->kill); |
3411 | else | |
3412 | { | |
4fb07d00 | 3413 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
48e1416a | 3414 | bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
3072d30e | 3415 | bb_info->out, bb_info->kill); |
3416 | return true; | |
3417 | } | |
3418 | } | |
3419 | else | |
3420 | /* Case 2 above. */ | |
3421 | return false; | |
3422 | } | |
3423 | else | |
3424 | { | |
3425 | /* Case 1 above. If there is already an in set, nothing | |
3426 | happens. */ | |
3427 | if (bb_info->in) | |
3428 | return false; | |
3429 | else | |
3430 | { | |
4fb07d00 | 3431 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
3072d30e | 3432 | bitmap_copy (bb_info->in, bb_info->gen); |
3433 | return true; | |
3434 | } | |
3435 | } | |
3436 | } | |
3437 | ||
3438 | /* Solve the dataflow equations. */ | |
3439 | ||
3440 | static void | |
3441 | dse_step4 (void) | |
3442 | { | |
48e1416a | 3443 | df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0, |
3444 | dse_confluence_n, dse_transfer_function, | |
3445 | all_blocks, df_get_postorder (DF_BACKWARD), | |
3072d30e | 3446 | df_get_n_blocks (DF_BACKWARD)); |
1ca59310 | 3447 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 3448 | { |
3449 | basic_block bb; | |
3450 | ||
3451 | fprintf (dump_file, "\n\n*** Global dataflow info after analysis.\n"); | |
ed7d889a | 3452 | FOR_ALL_BB_FN (bb, cfun) |
3072d30e | 3453 | { |
3454 | bb_info_t bb_info = bb_table[bb->index]; | |
3455 | ||
3456 | df_print_bb_index (bb, dump_file); | |
3457 | if (bb_info->in) | |
3458 | bitmap_print (dump_file, bb_info->in, " in: ", "\n"); | |
3459 | else | |
3460 | fprintf (dump_file, " in: *MISSING*\n"); | |
3461 | if (bb_info->gen) | |
3462 | bitmap_print (dump_file, bb_info->gen, " gen: ", "\n"); | |
3463 | else | |
3464 | fprintf (dump_file, " gen: *MISSING*\n"); | |
3465 | if (bb_info->kill) | |
3466 | bitmap_print (dump_file, bb_info->kill, " kill: ", "\n"); | |
3467 | else | |
3468 | fprintf (dump_file, " kill: *MISSING*\n"); | |
3469 | if (bb_info->out) | |
3470 | bitmap_print (dump_file, bb_info->out, " out: ", "\n"); | |
3471 | else | |
3472 | fprintf (dump_file, " out: *MISSING*\n\n"); | |
3473 | } | |
3474 | } | |
3475 | } | |
3476 | ||
3477 | ||
3478 | \f | |
3479 | /*---------------------------------------------------------------------------- | |
3480 | Fifth step. | |
3481 | ||
bef304b8 | 3482 | Delete the stores that can only be deleted using the global information. |
3072d30e | 3483 | ----------------------------------------------------------------------------*/ |
3484 | ||
3485 | ||
3486 | static void | |
3487 | dse_step5_nospill (void) | |
3488 | { | |
3489 | basic_block bb; | |
fc00614f | 3490 | FOR_EACH_BB_FN (bb, cfun) |
3072d30e | 3491 | { |
3492 | bb_info_t bb_info = bb_table[bb->index]; | |
3493 | insn_info_t insn_info = bb_info->last_insn; | |
3494 | bitmap v = bb_info->out; | |
3495 | ||
3496 | while (insn_info) | |
3497 | { | |
3498 | bool deleted = false; | |
3499 | if (dump_file && insn_info->insn) | |
3500 | { | |
3501 | fprintf (dump_file, "starting to process insn %d\n", | |
3502 | INSN_UID (insn_info->insn)); | |
3503 | bitmap_print (dump_file, v, " v: ", "\n"); | |
3504 | } | |
3505 | ||
3506 | /* There may have been code deleted by the dce pass run before | |
3507 | this phase. */ | |
48e1416a | 3508 | if (insn_info->insn |
3072d30e | 3509 | && INSN_P (insn_info->insn) |
3510 | && (!insn_info->cannot_delete) | |
3511 | && (!bitmap_empty_p (v))) | |
3512 | { | |
c2eab334 | 3513 | store_info *store_info = insn_info->store_rec; |
3072d30e | 3514 | |
3515 | /* Try to delete the current insn. */ | |
3516 | deleted = true; | |
48e1416a | 3517 | |
3072d30e | 3518 | /* Skip the clobbers. */ |
3519 | while (!store_info->is_set) | |
3520 | store_info = store_info->next; | |
3521 | ||
3522 | if (store_info->alias_set) | |
3523 | deleted = false; | |
3524 | else | |
3525 | { | |
3526 | HOST_WIDE_INT i; | |
c2eab334 | 3527 | group_info *group_info |
f1f41a6c | 3528 | = rtx_group_vec[store_info->group_id]; |
48e1416a | 3529 | |
3072d30e | 3530 | for (i = store_info->begin; i < store_info->end; i++) |
3531 | { | |
3532 | int index = get_bitmap_index (group_info, i); | |
48e1416a | 3533 | |
1ca59310 | 3534 | if (dump_file && (dump_flags & TDF_DETAILS)) |
48e1416a | 3535 | fprintf (dump_file, "i = %d, index = %d\n", (int)i, index); |
3072d30e | 3536 | if (index == 0 || !bitmap_bit_p (v, index)) |
3537 | { | |
1ca59310 | 3538 | if (dump_file && (dump_flags & TDF_DETAILS)) |
48e1416a | 3539 | fprintf (dump_file, "failing at i = %d\n", (int)i); |
3072d30e | 3540 | deleted = false; |
3541 | break; | |
3542 | } | |
3543 | } | |
3544 | } | |
3545 | if (deleted) | |
3546 | { | |
5a9ecd4a | 3547 | if (dbg_cnt (dse) |
3548 | && check_for_inc_dec_1 (insn_info)) | |
3072d30e | 3549 | { |
3072d30e | 3550 | delete_insn (insn_info->insn); |
3551 | insn_info->insn = NULL; | |
3552 | globally_deleted++; | |
3553 | } | |
3554 | } | |
3555 | } | |
3556 | /* We do want to process the local info if the insn was | |
6dfdc153 | 3557 | deleted. For instance, if the insn did a wild read, we |
3072d30e | 3558 | no longer need to trash the info. */ |
48e1416a | 3559 | if (insn_info->insn |
3072d30e | 3560 | && INSN_P (insn_info->insn) |
3561 | && (!deleted)) | |
3562 | { | |
3563 | scan_stores_nospill (insn_info->store_rec, v, NULL); | |
3564 | if (insn_info->wild_read) | |
3565 | { | |
1ca59310 | 3566 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 3567 | fprintf (dump_file, "wild read\n"); |
3568 | bitmap_clear (v); | |
3569 | } | |
b4a708fb | 3570 | else if (insn_info->read_rec |
3571 | || insn_info->non_frame_wild_read) | |
3072d30e | 3572 | { |
b4a708fb | 3573 | if (dump_file && !insn_info->non_frame_wild_read) |
3072d30e | 3574 | fprintf (dump_file, "regular read\n"); |
1ca59310 | 3575 | else if (dump_file && (dump_flags & TDF_DETAILS)) |
b4a708fb | 3576 | fprintf (dump_file, "non-frame wild read\n"); |
3072d30e | 3577 | scan_reads_nospill (insn_info, v, NULL); |
3578 | } | |
3579 | } | |
48e1416a | 3580 | |
3072d30e | 3581 | insn_info = insn_info->prev_insn; |
3582 | } | |
3583 | } | |
3584 | } | |
3585 | ||
3586 | ||
3072d30e | 3587 | \f |
3588 | /*---------------------------------------------------------------------------- | |
3589 | Sixth step. | |
3590 | ||
aa140b76 | 3591 | Delete stores made redundant by earlier stores (which store the same |
3592 | value) that couldn't be eliminated. | |
3593 | ----------------------------------------------------------------------------*/ | |
3594 | ||
3595 | static void | |
3596 | dse_step6 (void) | |
3597 | { | |
3598 | basic_block bb; | |
3599 | ||
ed7d889a | 3600 | FOR_ALL_BB_FN (bb, cfun) |
aa140b76 | 3601 | { |
3602 | bb_info_t bb_info = bb_table[bb->index]; | |
3603 | insn_info_t insn_info = bb_info->last_insn; | |
3604 | ||
3605 | while (insn_info) | |
3606 | { | |
3607 | /* There may have been code deleted by the dce pass run before | |
3608 | this phase. */ | |
3609 | if (insn_info->insn | |
3610 | && INSN_P (insn_info->insn) | |
3611 | && !insn_info->cannot_delete) | |
3612 | { | |
c2eab334 | 3613 | store_info *s_info = insn_info->store_rec; |
aa140b76 | 3614 | |
3615 | while (s_info && !s_info->is_set) | |
3616 | s_info = s_info->next; | |
3617 | if (s_info | |
3618 | && s_info->redundant_reason | |
3619 | && s_info->redundant_reason->insn | |
3620 | && INSN_P (s_info->redundant_reason->insn)) | |
3621 | { | |
cccc26f6 | 3622 | rtx_insn *rinsn = s_info->redundant_reason->insn; |
1ca59310 | 3623 | if (dump_file && (dump_flags & TDF_DETAILS)) |
aa140b76 | 3624 | fprintf (dump_file, "Locally deleting insn %d " |
3625 | "because insn %d stores the " | |
3626 | "same value and couldn't be " | |
3627 | "eliminated\n", | |
3628 | INSN_UID (insn_info->insn), | |
3629 | INSN_UID (rinsn)); | |
3630 | delete_dead_store_insn (insn_info); | |
3631 | } | |
3632 | } | |
3633 | insn_info = insn_info->prev_insn; | |
3634 | } | |
3635 | } | |
3636 | } | |
3637 | \f | |
3638 | /*---------------------------------------------------------------------------- | |
3639 | Seventh step. | |
3640 | ||
48e1416a | 3641 | Destroy everything left standing. |
3072d30e | 3642 | ----------------------------------------------------------------------------*/ |
3643 | ||
48e1416a | 3644 | static void |
4fb07d00 | 3645 | dse_step7 (void) |
3072d30e | 3646 | { |
4fb07d00 | 3647 | bitmap_obstack_release (&dse_bitmap_obstack); |
3648 | obstack_free (&dse_obstack, NULL); | |
ce299759 | 3649 | |
3072d30e | 3650 | end_alias_analysis (); |
3651 | free (bb_table); | |
c1f445d2 | 3652 | delete rtx_group_table; |
3653 | rtx_group_table = NULL; | |
f1f41a6c | 3654 | rtx_group_vec.release (); |
3072d30e | 3655 | BITMAP_FREE (all_blocks); |
3656 | BITMAP_FREE (scratch); | |
3657 | ||
55c5ac9f | 3658 | rtx_store_info_pool.release (); |
e16712b1 | 3659 | read_info_type_pool.release (); |
3660 | insn_info_type_pool.release (); | |
3661 | dse_bb_info_type_pool.release (); | |
3662 | group_info_pool.release (); | |
3663 | deferred_change_pool.release (); | |
3072d30e | 3664 | } |
3665 | ||
3666 | ||
3072d30e | 3667 | /* ------------------------------------------------------------------------- |
3668 | DSE | |
3669 | ------------------------------------------------------------------------- */ | |
3670 | ||
3671 | /* Callback for running pass_rtl_dse. */ | |
3672 | ||
3673 | static unsigned int | |
3674 | rest_of_handle_dse (void) | |
3675 | { | |
3072d30e | 3676 | df_set_flags (DF_DEFER_INSN_RESCAN); |
3677 | ||
a1b0a968 | 3678 | /* Need the notes since we must track live hardregs in the forwards |
3679 | direction. */ | |
3680 | df_note_add_problem (); | |
3681 | df_analyze (); | |
3682 | ||
3072d30e | 3683 | dse_step0 (); |
3684 | dse_step1 (); | |
3685 | dse_step2_init (); | |
3686 | if (dse_step2_nospill ()) | |
3687 | { | |
3688 | df_set_flags (DF_LR_RUN_DCE); | |
3689 | df_analyze (); | |
1ca59310 | 3690 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3072d30e | 3691 | fprintf (dump_file, "doing global processing\n"); |
3692 | dse_step3 (false); | |
3693 | dse_step4 (); | |
3694 | dse_step5_nospill (); | |
3695 | } | |
3696 | ||
aa140b76 | 3697 | dse_step6 (); |
4fb07d00 | 3698 | dse_step7 (); |
3072d30e | 3699 | |
3700 | if (dump_file) | |
3701 | fprintf (dump_file, "dse: local deletions = %d, global deletions = %d, spill deletions = %d\n", | |
3702 | locally_deleted, globally_deleted, spill_deleted); | |
1f91a12d | 3703 | |
3704 | /* DSE can eliminate potentially-trapping MEMs. | |
3705 | Remove any EH edges associated with them. */ | |
3706 | if ((locally_deleted || globally_deleted) | |
3707 | && cfun->can_throw_non_call_exceptions | |
3708 | && purge_all_dead_edges ()) | |
3709 | cleanup_cfg (0); | |
3710 | ||
3072d30e | 3711 | return 0; |
3712 | } | |
3713 | ||
7620bc82 | 3714 | namespace { |
3715 | ||
3716 | const pass_data pass_data_rtl_dse1 = | |
cbe8bda8 | 3717 | { |
3718 | RTL_PASS, /* type */ | |
3719 | "dse1", /* name */ | |
3720 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3721 | TV_DSE1, /* tv_id */ |
3722 | 0, /* properties_required */ | |
3723 | 0, /* properties_provided */ | |
3724 | 0, /* properties_destroyed */ | |
3725 | 0, /* todo_flags_start */ | |
8b88439e | 3726 | TODO_df_finish, /* todo_flags_finish */ |
3072d30e | 3727 | }; |
3728 | ||
7620bc82 | 3729 | class pass_rtl_dse1 : public rtl_opt_pass |
cbe8bda8 | 3730 | { |
3731 | public: | |
9af5ce0c | 3732 | pass_rtl_dse1 (gcc::context *ctxt) |
3733 | : rtl_opt_pass (pass_data_rtl_dse1, ctxt) | |
cbe8bda8 | 3734 | {} |
3735 | ||
3736 | /* opt_pass methods: */ | |
31315c24 | 3737 | virtual bool gate (function *) |
3738 | { | |
3739 | return optimize > 0 && flag_dse && dbg_cnt (dse1); | |
3740 | } | |
3741 | ||
65b0537f | 3742 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
cbe8bda8 | 3743 | |
3744 | }; // class pass_rtl_dse1 | |
3745 | ||
7620bc82 | 3746 | } // anon namespace |
3747 | ||
cbe8bda8 | 3748 | rtl_opt_pass * |
3749 | make_pass_rtl_dse1 (gcc::context *ctxt) | |
3750 | { | |
3751 | return new pass_rtl_dse1 (ctxt); | |
3752 | } | |
3753 | ||
7620bc82 | 3754 | namespace { |
3755 | ||
3756 | const pass_data pass_data_rtl_dse2 = | |
cbe8bda8 | 3757 | { |
3758 | RTL_PASS, /* type */ | |
3759 | "dse2", /* name */ | |
3760 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3761 | TV_DSE2, /* tv_id */ |
3762 | 0, /* properties_required */ | |
3763 | 0, /* properties_provided */ | |
3764 | 0, /* properties_destroyed */ | |
3765 | 0, /* todo_flags_start */ | |
8b88439e | 3766 | TODO_df_finish, /* todo_flags_finish */ |
3072d30e | 3767 | }; |
cbe8bda8 | 3768 | |
7620bc82 | 3769 | class pass_rtl_dse2 : public rtl_opt_pass |
cbe8bda8 | 3770 | { |
3771 | public: | |
9af5ce0c | 3772 | pass_rtl_dse2 (gcc::context *ctxt) |
3773 | : rtl_opt_pass (pass_data_rtl_dse2, ctxt) | |
cbe8bda8 | 3774 | {} |
3775 | ||
3776 | /* opt_pass methods: */ | |
31315c24 | 3777 | virtual bool gate (function *) |
3778 | { | |
3779 | return optimize > 0 && flag_dse && dbg_cnt (dse2); | |
3780 | } | |
3781 | ||
65b0537f | 3782 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
cbe8bda8 | 3783 | |
3784 | }; // class pass_rtl_dse2 | |
3785 | ||
7620bc82 | 3786 | } // anon namespace |
3787 | ||
cbe8bda8 | 3788 | rtl_opt_pass * |
3789 | make_pass_rtl_dse2 (gcc::context *ctxt) | |
3790 | { | |
3791 | return new pass_rtl_dse2 (ctxt); | |
3792 | } |