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6fb5fa3c | 1 | /* RTL dead store elimination. |
5624e564 | 2 | Copyright (C) 2005-2015 Free Software Foundation, Inc. |
6fb5fa3c DB |
3 | |
4 | Contributed by Richard Sandiford <rsandifor@codesourcery.com> | |
5 | and Kenneth Zadeck <zadeck@naturalbridge.com> | |
6 | ||
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it under | |
10 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 11 | Software Foundation; either version 3, or (at your option) any later |
6fb5fa3c DB |
12 | version. |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
15 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
17 | for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
6fb5fa3c DB |
22 | |
23 | #undef BASELINE | |
24 | ||
25 | #include "config.h" | |
26 | #include "system.h" | |
27 | #include "coretypes.h" | |
c7131fb2 | 28 | #include "backend.h" |
9fdcd34e | 29 | #include "predict.h" |
c7131fb2 AM |
30 | #include "tree.h" |
31 | #include "gimple.h" | |
6fb5fa3c | 32 | #include "rtl.h" |
c7131fb2 | 33 | #include "df.h" |
40e23961 | 34 | #include "alias.h" |
40e23961 | 35 | #include "fold-const.h" |
d8a2d370 | 36 | #include "stor-layout.h" |
18b526e8 | 37 | #include "tm_p.h" |
6fb5fa3c | 38 | #include "regs.h" |
9e582b1d | 39 | #include "regset.h" |
6fb5fa3c | 40 | #include "flags.h" |
60393bbc | 41 | #include "cfgrtl.h" |
6fb5fa3c | 42 | #include "cselib.h" |
6fb5fa3c DB |
43 | #include "tree-pass.h" |
44 | #include "alloc-pool.h" | |
6fb5fa3c | 45 | #include "insn-config.h" |
36566b39 PK |
46 | #include "expmed.h" |
47 | #include "dojump.h" | |
48 | #include "explow.h" | |
49 | #include "calls.h" | |
50 | #include "emit-rtl.h" | |
51 | #include "varasm.h" | |
52 | #include "stmt.h" | |
6fb5fa3c DB |
53 | #include "expr.h" |
54 | #include "recog.h" | |
b0710fe1 | 55 | #include "insn-codes.h" |
8660aaae | 56 | #include "optabs.h" |
6fb5fa3c | 57 | #include "dbgcnt.h" |
67d0afe9 | 58 | #include "target.h" |
dabd47e7 | 59 | #include "params.h" |
2fb9a547 | 60 | #include "internal-fn.h" |
442b4905 | 61 | #include "gimple-ssa.h" |
d7111da8 | 62 | #include "rtl-iter.h" |
6c5ed3f1 | 63 | #include "cfgcleanup.h" |
6fb5fa3c DB |
64 | |
65 | /* This file contains three techniques for performing Dead Store | |
b8698a0f | 66 | Elimination (dse). |
6fb5fa3c DB |
67 | |
68 | * The first technique performs dse locally on any base address. It | |
69 | is based on the cselib which is a local value numbering technique. | |
70 | This technique is local to a basic block but deals with a fairly | |
71 | general addresses. | |
b8698a0f | 72 | |
6fb5fa3c DB |
73 | * The second technique performs dse globally but is restricted to |
74 | base addresses that are either constant or are relative to the | |
75 | frame_pointer. | |
76 | ||
77 | * The third technique, (which is only done after register allocation) | |
026c3cfd | 78 | processes the spill slots. This differs from the second |
6fb5fa3c DB |
79 | technique because it takes advantage of the fact that spilling is |
80 | completely free from the effects of aliasing. | |
81 | ||
82 | Logically, dse is a backwards dataflow problem. A store can be | |
83 | deleted if it if cannot be reached in the backward direction by any | |
84 | use of the value being stored. However, the local technique uses a | |
85 | forwards scan of the basic block because cselib requires that the | |
86 | block be processed in that order. | |
87 | ||
88 | The pass is logically broken into 7 steps: | |
89 | ||
90 | 0) Initialization. | |
91 | ||
92 | 1) The local algorithm, as well as scanning the insns for the two | |
93 | global algorithms. | |
94 | ||
95 | 2) Analysis to see if the global algs are necessary. In the case | |
96 | of stores base on a constant address, there must be at least two | |
97 | stores to that address, to make it possible to delete some of the | |
98 | stores. In the case of stores off of the frame or spill related | |
99 | stores, only one store to an address is necessary because those | |
100 | stores die at the end of the function. | |
101 | ||
b8698a0f | 102 | 3) Set up the global dataflow equations based on processing the |
6fb5fa3c DB |
103 | info parsed in the first step. |
104 | ||
105 | 4) Solve the dataflow equations. | |
106 | ||
107 | 5) Delete the insns that the global analysis has indicated are | |
108 | unnecessary. | |
109 | ||
073a8998 | 110 | 6) Delete insns that store the same value as preceding store |
8dd5516b JJ |
111 | where the earlier store couldn't be eliminated. |
112 | ||
113 | 7) Cleanup. | |
6fb5fa3c DB |
114 | |
115 | This step uses cselib and canon_rtx to build the largest expression | |
116 | possible for each address. This pass is a forwards pass through | |
117 | each basic block. From the point of view of the global technique, | |
118 | the first pass could examine a block in either direction. The | |
0d52bcc1 | 119 | forwards ordering is to accommodate cselib. |
6fb5fa3c | 120 | |
5ef0b50d | 121 | We make a simplifying assumption: addresses fall into four broad |
6fb5fa3c DB |
122 | categories: |
123 | ||
124 | 1) base has rtx_varies_p == false, offset is constant. | |
125 | 2) base has rtx_varies_p == false, offset variable. | |
126 | 3) base has rtx_varies_p == true, offset constant. | |
127 | 4) base has rtx_varies_p == true, offset variable. | |
128 | ||
129 | The local passes are able to process all 4 kinds of addresses. The | |
5ef0b50d | 130 | global pass only handles 1). |
6fb5fa3c DB |
131 | |
132 | The global problem is formulated as follows: | |
133 | ||
134 | A store, S1, to address A, where A is not relative to the stack | |
135 | frame, can be eliminated if all paths from S1 to the end of the | |
5ef0b50d | 136 | function contain another store to A before a read to A. |
6fb5fa3c DB |
137 | |
138 | If the address A is relative to the stack frame, a store S2 to A | |
5ef0b50d | 139 | can be eliminated if there are no paths from S2 that reach the |
6fb5fa3c | 140 | end of the function that read A before another store to A. In |
5ef0b50d | 141 | this case S2 can be deleted if there are paths from S2 to the |
6fb5fa3c DB |
142 | end of the function that have no reads or writes to A. This |
143 | second case allows stores to the stack frame to be deleted that | |
144 | would otherwise die when the function returns. This cannot be | |
145 | done if stores_off_frame_dead_at_return is not true. See the doc | |
146 | for that variable for when this variable is false. | |
147 | ||
148 | The global problem is formulated as a backwards set union | |
149 | dataflow problem where the stores are the gens and reads are the | |
150 | kills. Set union problems are rare and require some special | |
151 | handling given our representation of bitmaps. A straightforward | |
5ef0b50d | 152 | implementation requires a lot of bitmaps filled with 1s. |
6fb5fa3c DB |
153 | These are expensive and cumbersome in our bitmap formulation so |
154 | care has been taken to avoid large vectors filled with 1s. See | |
155 | the comments in bb_info and in the dataflow confluence functions | |
b8698a0f | 156 | for details. |
6fb5fa3c DB |
157 | |
158 | There are two places for further enhancements to this algorithm: | |
b8698a0f | 159 | |
6fb5fa3c DB |
160 | 1) The original dse which was embedded in a pass called flow also |
161 | did local address forwarding. For example in | |
162 | ||
163 | A <- r100 | |
164 | ... <- A | |
165 | ||
166 | flow would replace the right hand side of the second insn with a | |
6ed3da00 | 167 | reference to r100. Most of the information is available to add this |
6fb5fa3c DB |
168 | to this pass. It has not done it because it is a lot of work in |
169 | the case that either r100 is assigned to between the first and | |
170 | second insn and/or the second insn is a load of part of the value | |
171 | stored by the first insn. | |
172 | ||
173 | insn 5 in gcc.c-torture/compile/990203-1.c simple case. | |
174 | insn 15 in gcc.c-torture/execute/20001017-2.c simple case. | |
175 | insn 25 in gcc.c-torture/execute/20001026-1.c simple case. | |
176 | insn 44 in gcc.c-torture/execute/20010910-1.c simple case. | |
177 | ||
178 | 2) The cleaning up of spill code is quite profitable. It currently | |
179 | depends on reading tea leaves and chicken entrails left by reload. | |
180 | This pass depends on reload creating a singleton alias set for each | |
181 | spill slot and telling the next dse pass which of these alias sets | |
182 | are the singletons. Rather than analyze the addresses of the | |
183 | spills, dse's spill processing just does analysis of the loads and | |
184 | stores that use those alias sets. There are three cases where this | |
185 | falls short: | |
186 | ||
187 | a) Reload sometimes creates the slot for one mode of access, and | |
188 | then inserts loads and/or stores for a smaller mode. In this | |
189 | case, the current code just punts on the slot. The proper thing | |
190 | to do is to back out and use one bit vector position for each | |
191 | byte of the entity associated with the slot. This depends on | |
192 | KNOWING that reload always generates the accesses for each of the | |
193 | bytes in some canonical (read that easy to understand several | |
194 | passes after reload happens) way. | |
195 | ||
196 | b) Reload sometimes decides that spill slot it allocated was not | |
197 | large enough for the mode and goes back and allocates more slots | |
198 | with the same mode and alias set. The backout in this case is a | |
199 | little more graceful than (a). In this case the slot is unmarked | |
200 | as being a spill slot and if final address comes out to be based | |
b8698a0f | 201 | off the frame pointer, the global algorithm handles this slot. |
6fb5fa3c DB |
202 | |
203 | c) For any pass that may prespill, there is currently no | |
204 | mechanism to tell the dse pass that the slot being used has the | |
205 | special properties that reload uses. It may be that all that is | |
0d52bcc1 | 206 | required is to have those passes make the same calls that reload |
6fb5fa3c DB |
207 | does, assuming that the alias sets can be manipulated in the same |
208 | way. */ | |
209 | ||
210 | /* There are limits to the size of constant offsets we model for the | |
211 | global problem. There are certainly test cases, that exceed this | |
212 | limit, however, it is unlikely that there are important programs | |
213 | that really have constant offsets this size. */ | |
214 | #define MAX_OFFSET (64 * 1024) | |
215 | ||
3f9b14ff SB |
216 | /* Obstack for the DSE dataflow bitmaps. We don't want to put these |
217 | on the default obstack because these bitmaps can grow quite large | |
218 | (~2GB for the small (!) test case of PR54146) and we'll hold on to | |
219 | all that memory until the end of the compiler run. | |
220 | As a bonus, delete_tree_live_info can destroy all the bitmaps by just | |
221 | releasing the whole obstack. */ | |
222 | static bitmap_obstack dse_bitmap_obstack; | |
223 | ||
224 | /* Obstack for other data. As for above: Kinda nice to be able to | |
225 | throw it all away at the end in one big sweep. */ | |
226 | static struct obstack dse_obstack; | |
227 | ||
228 | /* Scratch bitmap for cselib's cselib_expand_value_rtx. */ | |
6fb5fa3c | 229 | static bitmap scratch = NULL; |
3f9b14ff | 230 | |
da6603c6 | 231 | struct insn_info_type; |
6fb5fa3c DB |
232 | |
233 | /* This structure holds information about a candidate store. */ | |
b8698a0f | 234 | struct store_info |
6fb5fa3c DB |
235 | { |
236 | ||
237 | /* False means this is a clobber. */ | |
238 | bool is_set; | |
239 | ||
8dd5516b JJ |
240 | /* False if a single HOST_WIDE_INT bitmap is used for positions_needed. */ |
241 | bool is_large; | |
242 | ||
6fb5fa3c DB |
243 | /* The id of the mem group of the base address. If rtx_varies_p is |
244 | true, this is -1. Otherwise, it is the index into the group | |
245 | table. */ | |
246 | int group_id; | |
b8698a0f | 247 | |
6fb5fa3c DB |
248 | /* This is the cselib value. */ |
249 | cselib_val *cse_base; | |
250 | ||
251 | /* This canonized mem. */ | |
252 | rtx mem; | |
253 | ||
6216f94e | 254 | /* Canonized MEM address for use by canon_true_dependence. */ |
6fb5fa3c DB |
255 | rtx mem_addr; |
256 | ||
257 | /* If this is non-zero, it is the alias set of a spill location. */ | |
4862826d | 258 | alias_set_type alias_set; |
6fb5fa3c DB |
259 | |
260 | /* The offset of the first and byte before the last byte associated | |
261 | with the operation. */ | |
8dd5516b JJ |
262 | HOST_WIDE_INT begin, end; |
263 | ||
264 | union | |
265 | { | |
266 | /* A bitmask as wide as the number of bytes in the word that | |
267 | contains a 1 if the byte may be needed. The store is unused if | |
268 | all of the bits are 0. This is used if IS_LARGE is false. */ | |
269 | unsigned HOST_WIDE_INT small_bitmask; | |
270 | ||
271 | struct | |
272 | { | |
273 | /* A bitmap with one bit per byte. Cleared bit means the position | |
274 | is needed. Used if IS_LARGE is false. */ | |
dc491a25 | 275 | bitmap bmap; |
6fb5fa3c | 276 | |
8dd5516b JJ |
277 | /* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is |
278 | equal to END - BEGIN, the whole store is unused. */ | |
279 | int count; | |
280 | } large; | |
281 | } positions_needed; | |
6fb5fa3c DB |
282 | |
283 | /* The next store info for this insn. */ | |
284 | struct store_info *next; | |
285 | ||
286 | /* The right hand side of the store. This is used if there is a | |
287 | subsequent reload of the mems address somewhere later in the | |
288 | basic block. */ | |
8dd5516b JJ |
289 | rtx rhs; |
290 | ||
291 | /* If rhs is or holds a constant, this contains that constant, | |
292 | otherwise NULL. */ | |
293 | rtx const_rhs; | |
294 | ||
295 | /* Set if this store stores the same constant value as REDUNDANT_REASON | |
296 | insn stored. These aren't eliminated early, because doing that | |
297 | might prevent the earlier larger store to be eliminated. */ | |
da6603c6 | 298 | struct insn_info_type *redundant_reason; |
6fb5fa3c DB |
299 | }; |
300 | ||
4fe663b0 L |
301 | /* Return a bitmask with the first N low bits set. */ |
302 | ||
303 | static unsigned HOST_WIDE_INT | |
304 | lowpart_bitmask (int n) | |
305 | { | |
306 | unsigned HOST_WIDE_INT mask = ~(unsigned HOST_WIDE_INT) 0; | |
307 | return mask >> (HOST_BITS_PER_WIDE_INT - n); | |
308 | } | |
309 | ||
fcb87c50 | 310 | static object_allocator<store_info> cse_store_info_pool ("cse_store_info_pool"); |
da6603c6 | 311 | |
fcb87c50 | 312 | static object_allocator<store_info> rtx_store_info_pool ("rtx_store_info_pool"); |
6fb5fa3c DB |
313 | |
314 | /* This structure holds information about a load. These are only | |
315 | built for rtx bases. */ | |
da6603c6 | 316 | struct read_info_type |
6fb5fa3c DB |
317 | { |
318 | /* The id of the mem group of the base address. */ | |
319 | int group_id; | |
320 | ||
321 | /* If this is non-zero, it is the alias set of a spill location. */ | |
4862826d | 322 | alias_set_type alias_set; |
6fb5fa3c DB |
323 | |
324 | /* The offset of the first and byte after the last byte associated | |
325 | with the operation. If begin == end == 0, the read did not have | |
326 | a constant offset. */ | |
327 | int begin, end; | |
328 | ||
329 | /* The mem being read. */ | |
330 | rtx mem; | |
331 | ||
332 | /* The next read_info for this insn. */ | |
da6603c6 | 333 | struct read_info_type *next; |
6fb5fa3c | 334 | }; |
da6603c6 | 335 | typedef struct read_info_type *read_info_t; |
6fb5fa3c | 336 | |
fcb87c50 | 337 | static object_allocator<read_info_type> read_info_type_pool ("read_info_pool"); |
6fb5fa3c DB |
338 | |
339 | /* One of these records is created for each insn. */ | |
340 | ||
da6603c6 | 341 | struct insn_info_type |
6fb5fa3c DB |
342 | { |
343 | /* Set true if the insn contains a store but the insn itself cannot | |
344 | be deleted. This is set if the insn is a parallel and there is | |
345 | more than one non dead output or if the insn is in some way | |
346 | volatile. */ | |
347 | bool cannot_delete; | |
348 | ||
349 | /* This field is only used by the global algorithm. It is set true | |
350 | if the insn contains any read of mem except for a (1). This is | |
351 | also set if the insn is a call or has a clobber mem. If the insn | |
352 | contains a wild read, the use_rec will be null. */ | |
353 | bool wild_read; | |
354 | ||
d26c7090 ER |
355 | /* This is true only for CALL instructions which could potentially read |
356 | any non-frame memory location. This field is used by the global | |
357 | algorithm. */ | |
358 | bool non_frame_wild_read; | |
359 | ||
50f0f366 EB |
360 | /* This field is only used for the processing of const functions. |
361 | These functions cannot read memory, but they can read the stack | |
64520bdc EB |
362 | because that is where they may get their parms. We need to be |
363 | this conservative because, like the store motion pass, we don't | |
364 | consider CALL_INSN_FUNCTION_USAGE when processing call insns. | |
365 | Moreover, we need to distinguish two cases: | |
366 | 1. Before reload (register elimination), the stores related to | |
367 | outgoing arguments are stack pointer based and thus deemed | |
368 | of non-constant base in this pass. This requires special | |
369 | handling but also means that the frame pointer based stores | |
370 | need not be killed upon encountering a const function call. | |
371 | 2. After reload, the stores related to outgoing arguments can be | |
372 | either stack pointer or hard frame pointer based. This means | |
373 | that we have no other choice than also killing all the frame | |
374 | pointer based stores upon encountering a const function call. | |
57534689 JJ |
375 | This field is set after reload for const function calls and before |
376 | reload for const tail function calls on targets where arg pointer | |
377 | is the frame pointer. Having this set is less severe than a wild | |
378 | read, it just means that all the frame related stores are killed | |
379 | rather than all the stores. */ | |
64520bdc EB |
380 | bool frame_read; |
381 | ||
382 | /* This field is only used for the processing of const functions. | |
383 | It is set if the insn may contain a stack pointer based store. */ | |
50f0f366 | 384 | bool stack_pointer_based; |
6fb5fa3c DB |
385 | |
386 | /* This is true if any of the sets within the store contains a | |
387 | cselib base. Such stores can only be deleted by the local | |
388 | algorithm. */ | |
389 | bool contains_cselib_groups; | |
390 | ||
391 | /* The insn. */ | |
dd60a84c | 392 | rtx_insn *insn; |
6fb5fa3c DB |
393 | |
394 | /* The list of mem sets or mem clobbers that are contained in this | |
395 | insn. If the insn is deletable, it contains only one mem set. | |
396 | But it could also contain clobbers. Insns that contain more than | |
397 | one mem set are not deletable, but each of those mems are here in | |
6ed3da00 | 398 | order to provide info to delete other insns. */ |
fd6daec9 | 399 | store_info *store_rec; |
6fb5fa3c DB |
400 | |
401 | /* The linked list of mem uses in this insn. Only the reads from | |
402 | rtx bases are listed here. The reads to cselib bases are | |
403 | completely processed during the first scan and so are never | |
404 | created. */ | |
405 | read_info_t read_rec; | |
406 | ||
9e582b1d JR |
407 | /* The live fixed registers. We assume only fixed registers can |
408 | cause trouble by being clobbered from an expanded pattern; | |
409 | storing only the live fixed registers (rather than all registers) | |
410 | means less memory needs to be allocated / copied for the individual | |
411 | stores. */ | |
412 | regset fixed_regs_live; | |
413 | ||
6fb5fa3c | 414 | /* The prev insn in the basic block. */ |
da6603c6 | 415 | struct insn_info_type * prev_insn; |
6fb5fa3c DB |
416 | |
417 | /* The linked list of insns that are in consideration for removal in | |
073a8998 | 418 | the forwards pass through the basic block. This pointer may be |
6fb5fa3c | 419 | trash as it is not cleared when a wild read occurs. The only |
fa10beec | 420 | time it is guaranteed to be correct is when the traversal starts |
6fb5fa3c | 421 | at active_local_stores. */ |
da6603c6 | 422 | struct insn_info_type * next_local_store; |
6fb5fa3c | 423 | }; |
da6603c6 | 424 | typedef struct insn_info_type *insn_info_t; |
6fb5fa3c | 425 | |
fcb87c50 | 426 | static object_allocator<insn_info_type> insn_info_type_pool ("insn_info_pool"); |
6fb5fa3c DB |
427 | |
428 | /* The linked list of stores that are under consideration in this | |
b8698a0f | 429 | basic block. */ |
6fb5fa3c | 430 | static insn_info_t active_local_stores; |
dabd47e7 | 431 | static int active_local_stores_len; |
6fb5fa3c | 432 | |
da6603c6 | 433 | struct dse_bb_info_type |
6fb5fa3c | 434 | { |
6fb5fa3c DB |
435 | /* Pointer to the insn info for the last insn in the block. These |
436 | are linked so this is how all of the insns are reached. During | |
437 | scanning this is the current insn being scanned. */ | |
438 | insn_info_t last_insn; | |
439 | ||
440 | /* The info for the global dataflow problem. */ | |
441 | ||
442 | ||
443 | /* This is set if the transfer function should and in the wild_read | |
444 | bitmap before applying the kill and gen sets. That vector knocks | |
445 | out most of the bits in the bitmap and thus speeds up the | |
446 | operations. */ | |
447 | bool apply_wild_read; | |
448 | ||
02b47899 KZ |
449 | /* The following 4 bitvectors hold information about which positions |
450 | of which stores are live or dead. They are indexed by | |
451 | get_bitmap_index. */ | |
452 | ||
6fb5fa3c DB |
453 | /* The set of store positions that exist in this block before a wild read. */ |
454 | bitmap gen; | |
b8698a0f | 455 | |
6fb5fa3c DB |
456 | /* The set of load positions that exist in this block above the |
457 | same position of a store. */ | |
458 | bitmap kill; | |
459 | ||
460 | /* The set of stores that reach the top of the block without being | |
461 | killed by a read. | |
462 | ||
463 | Do not represent the in if it is all ones. Note that this is | |
464 | what the bitvector should logically be initialized to for a set | |
465 | intersection problem. However, like the kill set, this is too | |
466 | expensive. So initially, the in set will only be created for the | |
467 | exit block and any block that contains a wild read. */ | |
468 | bitmap in; | |
469 | ||
470 | /* The set of stores that reach the bottom of the block from it's | |
471 | successors. | |
472 | ||
473 | Do not represent the in if it is all ones. Note that this is | |
474 | what the bitvector should logically be initialized to for a set | |
475 | intersection problem. However, like the kill and in set, this is | |
476 | too expensive. So what is done is that the confluence operator | |
477 | just initializes the vector from one of the out sets of the | |
478 | successors of the block. */ | |
479 | bitmap out; | |
02b47899 KZ |
480 | |
481 | /* The following bitvector is indexed by the reg number. It | |
482 | contains the set of regs that are live at the current instruction | |
483 | being processed. While it contains info for all of the | |
9e582b1d JR |
484 | registers, only the hard registers are actually examined. It is used |
485 | to assure that shift and/or add sequences that are inserted do not | |
073a8998 | 486 | accidentally clobber live hard regs. */ |
02b47899 | 487 | bitmap regs_live; |
6fb5fa3c DB |
488 | }; |
489 | ||
da6603c6 | 490 | typedef struct dse_bb_info_type *bb_info_t; |
fb0b2914 ML |
491 | |
492 | static object_allocator<dse_bb_info_type> dse_bb_info_type_pool | |
fcb87c50 | 493 | ("bb_info_pool"); |
6fb5fa3c DB |
494 | |
495 | /* Table to hold all bb_infos. */ | |
496 | static bb_info_t *bb_table; | |
497 | ||
498 | /* There is a group_info for each rtx base that is used to reference | |
499 | memory. There are also not many of the rtx bases because they are | |
500 | very limited in scope. */ | |
501 | ||
b8698a0f | 502 | struct group_info |
6fb5fa3c DB |
503 | { |
504 | /* The actual base of the address. */ | |
505 | rtx rtx_base; | |
506 | ||
507 | /* The sequential id of the base. This allows us to have a | |
508 | canonical ordering of these that is not based on addresses. */ | |
509 | int id; | |
510 | ||
8f5929e1 JJ |
511 | /* True if there are any positions that are to be processed |
512 | globally. */ | |
513 | bool process_globally; | |
514 | ||
515 | /* True if the base of this group is either the frame_pointer or | |
516 | hard_frame_pointer. */ | |
517 | bool frame_related; | |
518 | ||
d32f725a OH |
519 | /* A mem wrapped around the base pointer for the group in order to do |
520 | read dependency. It must be given BLKmode in order to encompass all | |
521 | the possible offsets from the base. */ | |
6fb5fa3c | 522 | rtx base_mem; |
b8698a0f | 523 | |
6216f94e JJ |
524 | /* Canonized version of base_mem's address. */ |
525 | rtx canon_base_addr; | |
6fb5fa3c DB |
526 | |
527 | /* These two sets of two bitmaps are used to keep track of how many | |
6ed3da00 | 528 | stores are actually referencing that position from this base. We |
6fb5fa3c | 529 | only do this for rtx bases as this will be used to assign |
6ed3da00 | 530 | positions in the bitmaps for the global problem. Bit N is set in |
6fb5fa3c DB |
531 | store1 on the first store for offset N. Bit N is set in store2 |
532 | for the second store to offset N. This is all we need since we | |
533 | only care about offsets that have two or more stores for them. | |
534 | ||
535 | The "_n" suffix is for offsets less than 0 and the "_p" suffix is | |
536 | for 0 and greater offsets. | |
537 | ||
538 | There is one special case here, for stores into the stack frame, | |
539 | we will or store1 into store2 before deciding which stores look | |
540 | at globally. This is because stores to the stack frame that have | |
541 | no other reads before the end of the function can also be | |
542 | deleted. */ | |
543 | bitmap store1_n, store1_p, store2_n, store2_p; | |
544 | ||
d26c7090 ER |
545 | /* These bitmaps keep track of offsets in this group escape this function. |
546 | An offset escapes if it corresponds to a named variable whose | |
547 | addressable flag is set. */ | |
548 | bitmap escaped_n, escaped_p; | |
549 | ||
6ed3da00 | 550 | /* The positions in this bitmap have the same assignments as the in, |
6fb5fa3c | 551 | out, gen and kill bitmaps. This bitmap is all zeros except for |
6ed3da00 | 552 | the positions that are occupied by stores for this group. */ |
6fb5fa3c DB |
553 | bitmap group_kill; |
554 | ||
6fb5fa3c | 555 | /* The offset_map is used to map the offsets from this base into |
6ed3da00 | 556 | positions in the global bitmaps. It is only created after all of |
6fb5fa3c DB |
557 | the all of stores have been scanned and we know which ones we |
558 | care about. */ | |
b8698a0f L |
559 | int *offset_map_n, *offset_map_p; |
560 | int offset_map_size_n, offset_map_size_p; | |
6fb5fa3c | 561 | }; |
da6603c6 | 562 | |
fcb87c50 | 563 | static object_allocator<group_info> group_info_pool ("rtx_group_info_pool"); |
6fb5fa3c | 564 | |
6fb5fa3c DB |
565 | /* Index into the rtx_group_vec. */ |
566 | static int rtx_group_next_id; | |
567 | ||
6fb5fa3c | 568 | |
fd6daec9 | 569 | static vec<group_info *> rtx_group_vec; |
6fb5fa3c DB |
570 | |
571 | ||
572 | /* This structure holds the set of changes that are being deferred | |
573 | when removing read operation. See replace_read. */ | |
b8698a0f | 574 | struct deferred_change |
6fb5fa3c DB |
575 | { |
576 | ||
577 | /* The mem that is being replaced. */ | |
578 | rtx *loc; | |
579 | ||
580 | /* The reg it is being replaced with. */ | |
581 | rtx reg; | |
582 | ||
583 | struct deferred_change *next; | |
584 | }; | |
585 | ||
fb0b2914 | 586 | static object_allocator<deferred_change> deferred_change_pool |
fcb87c50 | 587 | ("deferred_change_pool"); |
6fb5fa3c | 588 | |
fd6daec9 | 589 | static deferred_change *deferred_change_list = NULL; |
6fb5fa3c | 590 | |
6fb5fa3c | 591 | /* The group that holds all of the clear_alias_sets. */ |
fd6daec9 | 592 | static group_info *clear_alias_group; |
6fb5fa3c DB |
593 | |
594 | /* The modes of the clear_alias_sets. */ | |
595 | static htab_t clear_alias_mode_table; | |
596 | ||
597 | /* Hash table element to look up the mode for an alias set. */ | |
598 | struct clear_alias_mode_holder | |
599 | { | |
4862826d | 600 | alias_set_type alias_set; |
ef4bddc2 | 601 | machine_mode mode; |
6fb5fa3c DB |
602 | }; |
603 | ||
e3b5732b | 604 | /* This is true except if cfun->stdarg -- i.e. we cannot do |
9dd9bf80 | 605 | this for vararg functions because they play games with the frame. */ |
6fb5fa3c DB |
606 | static bool stores_off_frame_dead_at_return; |
607 | ||
608 | /* Counter for stats. */ | |
b8698a0f L |
609 | static int globally_deleted; |
610 | static int locally_deleted; | |
611 | static int spill_deleted; | |
612 | ||
6fb5fa3c DB |
613 | static bitmap all_blocks; |
614 | ||
d26c7090 ER |
615 | /* Locations that are killed by calls in the global phase. */ |
616 | static bitmap kill_on_calls; | |
617 | ||
6fb5fa3c DB |
618 | /* The number of bits used in the global bitmaps. */ |
619 | static unsigned int current_position; | |
6fb5fa3c DB |
620 | \f |
621 | /*---------------------------------------------------------------------------- | |
622 | Zeroth step. | |
623 | ||
b8698a0f | 624 | Initialization. |
6fb5fa3c DB |
625 | ----------------------------------------------------------------------------*/ |
626 | ||
6fb5fa3c DB |
627 | |
628 | /* Find the entry associated with ALIAS_SET. */ | |
629 | ||
630 | static struct clear_alias_mode_holder * | |
4862826d | 631 | clear_alias_set_lookup (alias_set_type alias_set) |
6fb5fa3c DB |
632 | { |
633 | struct clear_alias_mode_holder tmp_holder; | |
634 | void **slot; | |
b8698a0f | 635 | |
6fb5fa3c DB |
636 | tmp_holder.alias_set = alias_set; |
637 | slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, NO_INSERT); | |
638 | gcc_assert (*slot); | |
b8698a0f | 639 | |
f883e0a7 | 640 | return (struct clear_alias_mode_holder *) *slot; |
6fb5fa3c DB |
641 | } |
642 | ||
643 | ||
644 | /* Hashtable callbacks for maintaining the "bases" field of | |
645 | store_group_info, given that the addresses are function invariants. */ | |
646 | ||
8d67ee55 | 647 | struct invariant_group_base_hasher : nofree_ptr_hash <group_info> |
703c8606 | 648 | { |
67f58944 TS |
649 | static inline hashval_t hash (const group_info *); |
650 | static inline bool equal (const group_info *, const group_info *); | |
703c8606 LC |
651 | }; |
652 | ||
653 | inline bool | |
67f58944 TS |
654 | invariant_group_base_hasher::equal (const group_info *gi1, |
655 | const group_info *gi2) | |
6fb5fa3c | 656 | { |
6fb5fa3c DB |
657 | return rtx_equal_p (gi1->rtx_base, gi2->rtx_base); |
658 | } | |
659 | ||
703c8606 | 660 | inline hashval_t |
67f58944 | 661 | invariant_group_base_hasher::hash (const group_info *gi) |
6fb5fa3c | 662 | { |
6fb5fa3c DB |
663 | int do_not_record; |
664 | return hash_rtx (gi->rtx_base, Pmode, &do_not_record, NULL, false); | |
665 | } | |
666 | ||
703c8606 | 667 | /* Tables of group_info structures, hashed by base value. */ |
c203e8a7 | 668 | static hash_table<invariant_group_base_hasher> *rtx_group_table; |
703c8606 | 669 | |
6fb5fa3c DB |
670 | |
671 | /* Get the GROUP for BASE. Add a new group if it is not there. */ | |
672 | ||
fd6daec9 | 673 | static group_info * |
6fb5fa3c DB |
674 | get_group_info (rtx base) |
675 | { | |
b8698a0f | 676 | struct group_info tmp_gi; |
fd6daec9 | 677 | group_info *gi; |
703c8606 | 678 | group_info **slot; |
6fb5fa3c DB |
679 | |
680 | if (base) | |
681 | { | |
682 | /* Find the store_base_info structure for BASE, creating a new one | |
683 | if necessary. */ | |
684 | tmp_gi.rtx_base = base; | |
c203e8a7 | 685 | slot = rtx_group_table->find_slot (&tmp_gi, INSERT); |
fd6daec9 | 686 | gi = *slot; |
6fb5fa3c DB |
687 | } |
688 | else | |
689 | { | |
690 | if (!clear_alias_group) | |
691 | { | |
fb0b2914 | 692 | clear_alias_group = gi = group_info_pool.allocate (); |
6fb5fa3c DB |
693 | memset (gi, 0, sizeof (struct group_info)); |
694 | gi->id = rtx_group_next_id++; | |
3f9b14ff SB |
695 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
696 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
697 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
698 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
699 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
700 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
701 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c DB |
702 | gi->process_globally = false; |
703 | gi->offset_map_size_n = 0; | |
704 | gi->offset_map_size_p = 0; | |
705 | gi->offset_map_n = NULL; | |
706 | gi->offset_map_p = NULL; | |
9771b263 | 707 | rtx_group_vec.safe_push (gi); |
6fb5fa3c DB |
708 | } |
709 | return clear_alias_group; | |
710 | } | |
711 | ||
712 | if (gi == NULL) | |
713 | { | |
fb0b2914 | 714 | *slot = gi = group_info_pool.allocate (); |
6fb5fa3c DB |
715 | gi->rtx_base = base; |
716 | gi->id = rtx_group_next_id++; | |
d32f725a | 717 | gi->base_mem = gen_rtx_MEM (BLKmode, base); |
6216f94e | 718 | gi->canon_base_addr = canon_rtx (base); |
3f9b14ff SB |
719 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
720 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
721 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
722 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
723 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
724 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
725 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c | 726 | gi->process_globally = false; |
b8698a0f | 727 | gi->frame_related = |
6fb5fa3c DB |
728 | (base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx); |
729 | gi->offset_map_size_n = 0; | |
730 | gi->offset_map_size_p = 0; | |
731 | gi->offset_map_n = NULL; | |
732 | gi->offset_map_p = NULL; | |
9771b263 | 733 | rtx_group_vec.safe_push (gi); |
6fb5fa3c DB |
734 | } |
735 | ||
736 | return gi; | |
737 | } | |
738 | ||
739 | ||
740 | /* Initialization of data structures. */ | |
741 | ||
742 | static void | |
743 | dse_step0 (void) | |
744 | { | |
745 | locally_deleted = 0; | |
746 | globally_deleted = 0; | |
747 | spill_deleted = 0; | |
748 | ||
3f9b14ff SB |
749 | bitmap_obstack_initialize (&dse_bitmap_obstack); |
750 | gcc_obstack_init (&dse_obstack); | |
751 | ||
752 | scratch = BITMAP_ALLOC (®_obstack); | |
753 | kill_on_calls = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c | 754 | |
6fb5fa3c | 755 | |
c203e8a7 | 756 | rtx_group_table = new hash_table<invariant_group_base_hasher> (11); |
6fb5fa3c | 757 | |
8b1c6fd7 | 758 | bb_table = XNEWVEC (bb_info_t, last_basic_block_for_fn (cfun)); |
6fb5fa3c DB |
759 | rtx_group_next_id = 0; |
760 | ||
e3b5732b | 761 | stores_off_frame_dead_at_return = !cfun->stdarg; |
6fb5fa3c DB |
762 | |
763 | init_alias_analysis (); | |
b8698a0f | 764 | |
4b943a49 | 765 | clear_alias_group = NULL; |
6fb5fa3c DB |
766 | } |
767 | ||
768 | ||
769 | \f | |
770 | /*---------------------------------------------------------------------------- | |
771 | First step. | |
772 | ||
773 | Scan all of the insns. Any random ordering of the blocks is fine. | |
0d52bcc1 | 774 | Each block is scanned in forward order to accommodate cselib which |
6fb5fa3c DB |
775 | is used to remove stores with non-constant bases. |
776 | ----------------------------------------------------------------------------*/ | |
777 | ||
778 | /* Delete all of the store_info recs from INSN_INFO. */ | |
779 | ||
b8698a0f | 780 | static void |
6fb5fa3c DB |
781 | free_store_info (insn_info_t insn_info) |
782 | { | |
fd6daec9 TS |
783 | store_info *cur = insn_info->store_rec; |
784 | while (cur) | |
6fb5fa3c | 785 | { |
fd6daec9 TS |
786 | store_info *next = cur->next; |
787 | if (cur->is_large) | |
788 | BITMAP_FREE (cur->positions_needed.large.bmap); | |
789 | if (cur->cse_base) | |
790 | cse_store_info_pool.remove (cur); | |
6fb5fa3c | 791 | else |
fd6daec9 TS |
792 | rtx_store_info_pool.remove (cur); |
793 | cur = next; | |
6fb5fa3c DB |
794 | } |
795 | ||
796 | insn_info->cannot_delete = true; | |
797 | insn_info->contains_cselib_groups = false; | |
798 | insn_info->store_rec = NULL; | |
799 | } | |
800 | ||
a79683d5 | 801 | struct note_add_store_info |
9e582b1d | 802 | { |
dc01c3d1 | 803 | rtx_insn *first, *current; |
9e582b1d JR |
804 | regset fixed_regs_live; |
805 | bool failure; | |
a79683d5 | 806 | }; |
9e582b1d JR |
807 | |
808 | /* Callback for emit_inc_dec_insn_before via note_stores. | |
809 | Check if a register is clobbered which is live afterwards. */ | |
810 | ||
811 | static void | |
812 | note_add_store (rtx loc, const_rtx expr ATTRIBUTE_UNUSED, void *data) | |
813 | { | |
dc01c3d1 | 814 | rtx_insn *insn; |
9e582b1d | 815 | note_add_store_info *info = (note_add_store_info *) data; |
9e582b1d JR |
816 | |
817 | if (!REG_P (loc)) | |
818 | return; | |
819 | ||
820 | /* If this register is referenced by the current or an earlier insn, | |
821 | that's OK. E.g. this applies to the register that is being incremented | |
822 | with this addition. */ | |
823 | for (insn = info->first; | |
824 | insn != NEXT_INSN (info->current); | |
825 | insn = NEXT_INSN (insn)) | |
826 | if (reg_referenced_p (loc, PATTERN (insn))) | |
827 | return; | |
828 | ||
829 | /* If we come here, we have a clobber of a register that's only OK | |
830 | if that register is not live. If we don't have liveness information | |
831 | available, fail now. */ | |
832 | if (!info->fixed_regs_live) | |
833 | { | |
53d1bae9 | 834 | info->failure = true; |
9e582b1d JR |
835 | return; |
836 | } | |
837 | /* Now check if this is a live fixed register. */ | |
53d1bae9 RS |
838 | unsigned int end_regno = END_REGNO (loc); |
839 | for (unsigned int regno = REGNO (loc); regno < end_regno; ++regno) | |
840 | if (REGNO_REG_SET_P (info->fixed_regs_live, regno)) | |
841 | info->failure = true; | |
9e582b1d JR |
842 | } |
843 | ||
4deef538 AO |
844 | /* Callback for for_each_inc_dec that emits an INSN that sets DEST to |
845 | SRC + SRCOFF before insn ARG. */ | |
6fb5fa3c DB |
846 | |
847 | static int | |
4deef538 AO |
848 | emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED, |
849 | rtx op ATTRIBUTE_UNUSED, | |
850 | rtx dest, rtx src, rtx srcoff, void *arg) | |
6fb5fa3c | 851 | { |
9e582b1d | 852 | insn_info_t insn_info = (insn_info_t) arg; |
dc01c3d1 | 853 | rtx_insn *insn = insn_info->insn, *new_insn, *cur; |
9e582b1d | 854 | note_add_store_info info; |
b8698a0f | 855 | |
4deef538 AO |
856 | /* We can reuse all operands without copying, because we are about |
857 | to delete the insn that contained it. */ | |
9e582b1d | 858 | if (srcoff) |
ed079c4b JJ |
859 | { |
860 | start_sequence (); | |
861 | emit_insn (gen_add3_insn (dest, src, srcoff)); | |
862 | new_insn = get_insns (); | |
863 | end_sequence (); | |
864 | } | |
9e582b1d | 865 | else |
1476d1bd | 866 | new_insn = gen_move_insn (dest, src); |
9e582b1d JR |
867 | info.first = new_insn; |
868 | info.fixed_regs_live = insn_info->fixed_regs_live; | |
869 | info.failure = false; | |
870 | for (cur = new_insn; cur; cur = NEXT_INSN (cur)) | |
871 | { | |
872 | info.current = cur; | |
873 | note_stores (PATTERN (cur), note_add_store, &info); | |
874 | } | |
6fb5fa3c | 875 | |
9e582b1d JR |
876 | /* If a failure was flagged above, return 1 so that for_each_inc_dec will |
877 | return it immediately, communicating the failure to its caller. */ | |
878 | if (info.failure) | |
879 | return 1; | |
880 | ||
881 | emit_insn_before (new_insn, insn); | |
6fb5fa3c | 882 | |
8d8e205b | 883 | return 0; |
6fb5fa3c DB |
884 | } |
885 | ||
9e582b1d JR |
886 | /* Before we delete INSN_INFO->INSN, make sure that the auto inc/dec, if it |
887 | is there, is split into a separate insn. | |
888 | Return true on success (or if there was nothing to do), false on failure. */ | |
6fb5fa3c | 889 | |
9e582b1d JR |
890 | static bool |
891 | check_for_inc_dec_1 (insn_info_t insn_info) | |
6fb5fa3c | 892 | { |
dd60a84c | 893 | rtx_insn *insn = insn_info->insn; |
6fb5fa3c DB |
894 | rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
895 | if (note) | |
8d8e205b RS |
896 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
897 | insn_info) == 0; | |
9e582b1d | 898 | return true; |
6fb5fa3c DB |
899 | } |
900 | ||
901 | ||
9e582b1d JR |
902 | /* Entry point for postreload. If you work on reload_cse, or you need this |
903 | anywhere else, consider if you can provide register liveness information | |
904 | and add a parameter to this function so that it can be passed down in | |
905 | insn_info.fixed_regs_live. */ | |
906 | bool | |
dd60a84c | 907 | check_for_inc_dec (rtx_insn *insn) |
9e582b1d | 908 | { |
da6603c6 | 909 | insn_info_type insn_info; |
9e582b1d JR |
910 | rtx note; |
911 | ||
912 | insn_info.insn = insn; | |
913 | insn_info.fixed_regs_live = NULL; | |
914 | note = find_reg_note (insn, REG_INC, NULL_RTX); | |
915 | if (note) | |
8d8e205b RS |
916 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
917 | &insn_info) == 0; | |
9e582b1d JR |
918 | return true; |
919 | } | |
920 | ||
b8698a0f | 921 | /* Delete the insn and free all of the fields inside INSN_INFO. */ |
6fb5fa3c DB |
922 | |
923 | static void | |
924 | delete_dead_store_insn (insn_info_t insn_info) | |
925 | { | |
926 | read_info_t read_info; | |
927 | ||
928 | if (!dbg_cnt (dse)) | |
929 | return; | |
930 | ||
9e582b1d JR |
931 | if (!check_for_inc_dec_1 (insn_info)) |
932 | return; | |
456610d3 | 933 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 934 | { |
b8698a0f | 935 | fprintf (dump_file, "Locally deleting insn %d ", |
6fb5fa3c DB |
936 | INSN_UID (insn_info->insn)); |
937 | if (insn_info->store_rec->alias_set) | |
b8698a0f | 938 | fprintf (dump_file, "alias set %d\n", |
4862826d | 939 | (int) insn_info->store_rec->alias_set); |
6fb5fa3c DB |
940 | else |
941 | fprintf (dump_file, "\n"); | |
942 | } | |
943 | ||
944 | free_store_info (insn_info); | |
945 | read_info = insn_info->read_rec; | |
b8698a0f | 946 | |
6fb5fa3c DB |
947 | while (read_info) |
948 | { | |
949 | read_info_t next = read_info->next; | |
fb0b2914 | 950 | read_info_type_pool.remove (read_info); |
6fb5fa3c DB |
951 | read_info = next; |
952 | } | |
953 | insn_info->read_rec = NULL; | |
954 | ||
955 | delete_insn (insn_info->insn); | |
956 | locally_deleted++; | |
957 | insn_info->insn = NULL; | |
958 | ||
959 | insn_info->wild_read = false; | |
960 | } | |
961 | ||
88d8330d EB |
962 | /* Return whether DECL, a local variable, can possibly escape the current |
963 | function scope. */ | |
964 | ||
965 | static bool | |
966 | local_variable_can_escape (tree decl) | |
967 | { | |
968 | if (TREE_ADDRESSABLE (decl)) | |
969 | return true; | |
970 | ||
971 | /* If this is a partitioned variable, we need to consider all the variables | |
972 | in the partition. This is necessary because a store into one of them can | |
973 | be replaced with a store into another and this may not change the outcome | |
974 | of the escape analysis. */ | |
975 | if (cfun->gimple_df->decls_to_pointers != NULL) | |
976 | { | |
39c8aaa4 | 977 | tree *namep = cfun->gimple_df->decls_to_pointers->get (decl); |
88d8330d | 978 | if (namep) |
39c8aaa4 | 979 | return TREE_ADDRESSABLE (*namep); |
88d8330d EB |
980 | } |
981 | ||
982 | return false; | |
983 | } | |
984 | ||
985 | /* Return whether EXPR can possibly escape the current function scope. */ | |
986 | ||
d26c7090 ER |
987 | static bool |
988 | can_escape (tree expr) | |
989 | { | |
990 | tree base; | |
991 | if (!expr) | |
992 | return true; | |
993 | base = get_base_address (expr); | |
994 | if (DECL_P (base) | |
88d8330d EB |
995 | && !may_be_aliased (base) |
996 | && !(TREE_CODE (base) == VAR_DECL | |
997 | && !DECL_EXTERNAL (base) | |
998 | && !TREE_STATIC (base) | |
999 | && local_variable_can_escape (base))) | |
d26c7090 ER |
1000 | return false; |
1001 | return true; | |
1002 | } | |
6fb5fa3c DB |
1003 | |
1004 | /* Set the store* bitmaps offset_map_size* fields in GROUP based on | |
1005 | OFFSET and WIDTH. */ | |
1006 | ||
1007 | static void | |
fd6daec9 | 1008 | set_usage_bits (group_info *group, HOST_WIDE_INT offset, HOST_WIDE_INT width, |
d26c7090 | 1009 | tree expr) |
6fb5fa3c DB |
1010 | { |
1011 | HOST_WIDE_INT i; | |
d26c7090 | 1012 | bool expr_escapes = can_escape (expr); |
8dd5516b | 1013 | if (offset > -MAX_OFFSET && offset + width < MAX_OFFSET) |
6fb5fa3c DB |
1014 | for (i=offset; i<offset+width; i++) |
1015 | { | |
1016 | bitmap store1; | |
1017 | bitmap store2; | |
d26c7090 | 1018 | bitmap escaped; |
6fb5fa3c DB |
1019 | int ai; |
1020 | if (i < 0) | |
1021 | { | |
1022 | store1 = group->store1_n; | |
1023 | store2 = group->store2_n; | |
d26c7090 | 1024 | escaped = group->escaped_n; |
6fb5fa3c DB |
1025 | ai = -i; |
1026 | } | |
1027 | else | |
1028 | { | |
1029 | store1 = group->store1_p; | |
1030 | store2 = group->store2_p; | |
d26c7090 | 1031 | escaped = group->escaped_p; |
6fb5fa3c DB |
1032 | ai = i; |
1033 | } | |
b8698a0f | 1034 | |
fcaa4ca4 | 1035 | if (!bitmap_set_bit (store1, ai)) |
6fb5fa3c | 1036 | bitmap_set_bit (store2, ai); |
b8698a0f | 1037 | else |
6fb5fa3c | 1038 | { |
6fb5fa3c DB |
1039 | if (i < 0) |
1040 | { | |
1041 | if (group->offset_map_size_n < ai) | |
1042 | group->offset_map_size_n = ai; | |
1043 | } | |
1044 | else | |
1045 | { | |
1046 | if (group->offset_map_size_p < ai) | |
1047 | group->offset_map_size_p = ai; | |
1048 | } | |
1049 | } | |
d26c7090 ER |
1050 | if (expr_escapes) |
1051 | bitmap_set_bit (escaped, ai); | |
6fb5fa3c DB |
1052 | } |
1053 | } | |
1054 | ||
d26c7090 ER |
1055 | static void |
1056 | reset_active_stores (void) | |
1057 | { | |
1058 | active_local_stores = NULL; | |
1059 | active_local_stores_len = 0; | |
1060 | } | |
6fb5fa3c | 1061 | |
d26c7090 | 1062 | /* Free all READ_REC of the LAST_INSN of BB_INFO. */ |
6fb5fa3c DB |
1063 | |
1064 | static void | |
d26c7090 | 1065 | free_read_records (bb_info_t bb_info) |
6fb5fa3c DB |
1066 | { |
1067 | insn_info_t insn_info = bb_info->last_insn; | |
1068 | read_info_t *ptr = &insn_info->read_rec; | |
6fb5fa3c DB |
1069 | while (*ptr) |
1070 | { | |
1071 | read_info_t next = (*ptr)->next; | |
4862826d | 1072 | if ((*ptr)->alias_set == 0) |
6fb5fa3c | 1073 | { |
fb0b2914 | 1074 | read_info_type_pool.remove (*ptr); |
6fb5fa3c | 1075 | *ptr = next; |
d26c7090 | 1076 | } |
b8698a0f | 1077 | else |
d26c7090 | 1078 | ptr = &(*ptr)->next; |
6fb5fa3c | 1079 | } |
d26c7090 ER |
1080 | } |
1081 | ||
1082 | /* Set the BB_INFO so that the last insn is marked as a wild read. */ | |
1083 | ||
1084 | static void | |
1085 | add_wild_read (bb_info_t bb_info) | |
1086 | { | |
1087 | insn_info_t insn_info = bb_info->last_insn; | |
6fb5fa3c | 1088 | insn_info->wild_read = true; |
d26c7090 ER |
1089 | free_read_records (bb_info); |
1090 | reset_active_stores (); | |
6fb5fa3c DB |
1091 | } |
1092 | ||
d26c7090 ER |
1093 | /* Set the BB_INFO so that the last insn is marked as a wild read of |
1094 | non-frame locations. */ | |
1095 | ||
1096 | static void | |
1097 | add_non_frame_wild_read (bb_info_t bb_info) | |
1098 | { | |
1099 | insn_info_t insn_info = bb_info->last_insn; | |
1100 | insn_info->non_frame_wild_read = true; | |
1101 | free_read_records (bb_info); | |
1102 | reset_active_stores (); | |
1103 | } | |
6fb5fa3c | 1104 | |
50f0f366 EB |
1105 | /* Return true if X is a constant or one of the registers that behave |
1106 | as a constant over the life of a function. This is equivalent to | |
1107 | !rtx_varies_p for memory addresses. */ | |
6fb5fa3c DB |
1108 | |
1109 | static bool | |
1110 | const_or_frame_p (rtx x) | |
1111 | { | |
d8116890 KZ |
1112 | if (CONSTANT_P (x)) |
1113 | return true; | |
1114 | ||
1115 | if (GET_CODE (x) == REG) | |
6fb5fa3c | 1116 | { |
6fb5fa3c DB |
1117 | /* Note that we have to test for the actual rtx used for the frame |
1118 | and arg pointers and not just the register number in case we have | |
1119 | eliminated the frame and/or arg pointer and are using it | |
1120 | for pseudos. */ | |
1121 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx | |
1122 | /* The arg pointer varies if it is not a fixed register. */ | |
1123 | || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
1124 | || x == pic_offset_table_rtx) | |
1125 | return true; | |
1126 | return false; | |
6fb5fa3c | 1127 | } |
da6603c6 | 1128 | |
d8116890 | 1129 | return false; |
6fb5fa3c DB |
1130 | } |
1131 | ||
b8698a0f L |
1132 | /* Take all reasonable action to put the address of MEM into the form |
1133 | that we can do analysis on. | |
6fb5fa3c DB |
1134 | |
1135 | The gold standard is to get the address into the form: address + | |
1136 | OFFSET where address is something that rtx_varies_p considers a | |
1137 | constant. When we can get the address in this form, we can do | |
1138 | global analysis on it. Note that for constant bases, address is | |
1139 | not actually returned, only the group_id. The address can be | |
1140 | obtained from that. | |
1141 | ||
1142 | If that fails, we try cselib to get a value we can at least use | |
b8698a0f L |
1143 | locally. If that fails we return false. |
1144 | ||
6fb5fa3c DB |
1145 | The GROUP_ID is set to -1 for cselib bases and the index of the |
1146 | group for non_varying bases. | |
1147 | ||
1148 | FOR_READ is true if this is a mem read and false if not. */ | |
1149 | ||
1150 | static bool | |
1151 | canon_address (rtx mem, | |
4862826d | 1152 | alias_set_type *alias_set_out, |
6fb5fa3c | 1153 | int *group_id, |
b8698a0f | 1154 | HOST_WIDE_INT *offset, |
6fb5fa3c DB |
1155 | cselib_val **base) |
1156 | { | |
ef4bddc2 | 1157 | machine_mode address_mode = get_address_mode (mem); |
6fb5fa3c DB |
1158 | rtx mem_address = XEXP (mem, 0); |
1159 | rtx expanded_address, address; | |
403c7520 JJ |
1160 | int expanded; |
1161 | ||
6fb5fa3c DB |
1162 | *alias_set_out = 0; |
1163 | ||
4deef538 | 1164 | cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem)); |
6fb5fa3c | 1165 | |
456610d3 | 1166 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1167 | { |
1168 | fprintf (dump_file, " mem: "); | |
1169 | print_inline_rtx (dump_file, mem_address, 0); | |
1170 | fprintf (dump_file, "\n"); | |
1171 | } | |
1172 | ||
403c7520 JJ |
1173 | /* First see if just canon_rtx (mem_address) is const or frame, |
1174 | if not, try cselib_expand_value_rtx and call canon_rtx on that. */ | |
1175 | address = NULL_RTX; | |
1176 | for (expanded = 0; expanded < 2; expanded++) | |
1177 | { | |
1178 | if (expanded) | |
1179 | { | |
1180 | /* Use cselib to replace all of the reg references with the full | |
b8698a0f | 1181 | expression. This will take care of the case where we have |
6fb5fa3c | 1182 | |
403c7520 JJ |
1183 | r_x = base + offset; |
1184 | val = *r_x; | |
b8698a0f L |
1185 | |
1186 | by making it into | |
6fb5fa3c | 1187 | |
403c7520 | 1188 | val = *(base + offset); */ |
6fb5fa3c | 1189 | |
403c7520 JJ |
1190 | expanded_address = cselib_expand_value_rtx (mem_address, |
1191 | scratch, 5); | |
6fb5fa3c | 1192 | |
403c7520 JJ |
1193 | /* If this fails, just go with the address from first |
1194 | iteration. */ | |
1195 | if (!expanded_address) | |
1196 | break; | |
1197 | } | |
1198 | else | |
1199 | expanded_address = mem_address; | |
6fb5fa3c | 1200 | |
403c7520 JJ |
1201 | /* Split the address into canonical BASE + OFFSET terms. */ |
1202 | address = canon_rtx (expanded_address); | |
6fb5fa3c | 1203 | |
403c7520 | 1204 | *offset = 0; |
6fb5fa3c | 1205 | |
456610d3 | 1206 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1207 | { |
1208 | if (expanded) | |
1209 | { | |
1210 | fprintf (dump_file, "\n after cselib_expand address: "); | |
1211 | print_inline_rtx (dump_file, expanded_address, 0); | |
1212 | fprintf (dump_file, "\n"); | |
1213 | } | |
6fb5fa3c | 1214 | |
403c7520 JJ |
1215 | fprintf (dump_file, "\n after canon_rtx address: "); |
1216 | print_inline_rtx (dump_file, address, 0); | |
1217 | fprintf (dump_file, "\n"); | |
1218 | } | |
6fb5fa3c | 1219 | |
403c7520 JJ |
1220 | if (GET_CODE (address) == CONST) |
1221 | address = XEXP (address, 0); | |
6fb5fa3c | 1222 | |
403c7520 JJ |
1223 | if (GET_CODE (address) == PLUS |
1224 | && CONST_INT_P (XEXP (address, 1))) | |
1225 | { | |
1226 | *offset = INTVAL (XEXP (address, 1)); | |
1227 | address = XEXP (address, 0); | |
1228 | } | |
6fb5fa3c | 1229 | |
09e881c9 BE |
1230 | if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem)) |
1231 | && const_or_frame_p (address)) | |
6fb5fa3c | 1232 | { |
fd6daec9 | 1233 | group_info *group = get_group_info (address); |
403c7520 | 1234 | |
456610d3 | 1235 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1236 | fprintf (dump_file, " gid=%d offset=%d \n", |
1237 | group->id, (int)*offset); | |
1238 | *base = NULL; | |
1239 | *group_id = group->id; | |
1240 | return true; | |
6fb5fa3c | 1241 | } |
403c7520 JJ |
1242 | } |
1243 | ||
4deef538 | 1244 | *base = cselib_lookup (address, address_mode, true, GET_MODE (mem)); |
403c7520 JJ |
1245 | *group_id = -1; |
1246 | ||
1247 | if (*base == NULL) | |
1248 | { | |
456610d3 | 1249 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1250 | fprintf (dump_file, " no cselib val - should be a wild read.\n"); |
1251 | return false; | |
6fb5fa3c | 1252 | } |
456610d3 | 1253 | if (dump_file && (dump_flags & TDF_DETAILS)) |
5440c0e7 AO |
1254 | fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n", |
1255 | (*base)->uid, (*base)->hash, (int)*offset); | |
6fb5fa3c DB |
1256 | return true; |
1257 | } | |
1258 | ||
1259 | ||
1260 | /* Clear the rhs field from the active_local_stores array. */ | |
1261 | ||
1262 | static void | |
1263 | clear_rhs_from_active_local_stores (void) | |
1264 | { | |
1265 | insn_info_t ptr = active_local_stores; | |
1266 | ||
1267 | while (ptr) | |
1268 | { | |
fd6daec9 | 1269 | store_info *store_info = ptr->store_rec; |
6fb5fa3c DB |
1270 | /* Skip the clobbers. */ |
1271 | while (!store_info->is_set) | |
1272 | store_info = store_info->next; | |
1273 | ||
1274 | store_info->rhs = NULL; | |
8dd5516b | 1275 | store_info->const_rhs = NULL; |
6fb5fa3c DB |
1276 | |
1277 | ptr = ptr->next_local_store; | |
1278 | } | |
1279 | } | |
1280 | ||
1281 | ||
8dd5516b JJ |
1282 | /* Mark byte POS bytes from the beginning of store S_INFO as unneeded. */ |
1283 | ||
1284 | static inline void | |
fd6daec9 | 1285 | set_position_unneeded (store_info *s_info, int pos) |
8dd5516b JJ |
1286 | { |
1287 | if (__builtin_expect (s_info->is_large, false)) | |
1288 | { | |
fcaa4ca4 NF |
1289 | if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos)) |
1290 | s_info->positions_needed.large.count++; | |
8dd5516b JJ |
1291 | } |
1292 | else | |
1293 | s_info->positions_needed.small_bitmask | |
1294 | &= ~(((unsigned HOST_WIDE_INT) 1) << pos); | |
1295 | } | |
1296 | ||
1297 | /* Mark the whole store S_INFO as unneeded. */ | |
1298 | ||
1299 | static inline void | |
fd6daec9 | 1300 | set_all_positions_unneeded (store_info *s_info) |
8dd5516b JJ |
1301 | { |
1302 | if (__builtin_expect (s_info->is_large, false)) | |
1303 | { | |
1304 | int pos, end = s_info->end - s_info->begin; | |
1305 | for (pos = 0; pos < end; pos++) | |
dc491a25 | 1306 | bitmap_set_bit (s_info->positions_needed.large.bmap, pos); |
8dd5516b JJ |
1307 | s_info->positions_needed.large.count = end; |
1308 | } | |
1309 | else | |
1310 | s_info->positions_needed.small_bitmask = (unsigned HOST_WIDE_INT) 0; | |
1311 | } | |
1312 | ||
1313 | /* Return TRUE if any bytes from S_INFO store are needed. */ | |
1314 | ||
1315 | static inline bool | |
fd6daec9 | 1316 | any_positions_needed_p (store_info *s_info) |
8dd5516b JJ |
1317 | { |
1318 | if (__builtin_expect (s_info->is_large, false)) | |
1319 | return (s_info->positions_needed.large.count | |
1320 | < s_info->end - s_info->begin); | |
1321 | else | |
1322 | return (s_info->positions_needed.small_bitmask | |
1323 | != (unsigned HOST_WIDE_INT) 0); | |
1324 | } | |
1325 | ||
1326 | /* Return TRUE if all bytes START through START+WIDTH-1 from S_INFO | |
1327 | store are needed. */ | |
1328 | ||
1329 | static inline bool | |
fd6daec9 | 1330 | all_positions_needed_p (store_info *s_info, int start, int width) |
8dd5516b JJ |
1331 | { |
1332 | if (__builtin_expect (s_info->is_large, false)) | |
1333 | { | |
1334 | int end = start + width; | |
1335 | while (start < end) | |
dc491a25 | 1336 | if (bitmap_bit_p (s_info->positions_needed.large.bmap, start++)) |
8dd5516b JJ |
1337 | return false; |
1338 | return true; | |
1339 | } | |
1340 | else | |
1341 | { | |
1342 | unsigned HOST_WIDE_INT mask = lowpart_bitmask (width) << start; | |
1343 | return (s_info->positions_needed.small_bitmask & mask) == mask; | |
1344 | } | |
1345 | } | |
1346 | ||
1347 | ||
fd6daec9 | 1348 | static rtx get_stored_val (store_info *, machine_mode, HOST_WIDE_INT, |
8dd5516b JJ |
1349 | HOST_WIDE_INT, basic_block, bool); |
1350 | ||
1351 | ||
6fb5fa3c DB |
1352 | /* BODY is an instruction pattern that belongs to INSN. Return 1 if |
1353 | there is a candidate store, after adding it to the appropriate | |
1354 | local store group if so. */ | |
1355 | ||
1356 | static int | |
1357 | record_store (rtx body, bb_info_t bb_info) | |
1358 | { | |
6216f94e | 1359 | rtx mem, rhs, const_rhs, mem_addr; |
6fb5fa3c DB |
1360 | HOST_WIDE_INT offset = 0; |
1361 | HOST_WIDE_INT width = 0; | |
4862826d | 1362 | alias_set_type spill_alias_set; |
6fb5fa3c | 1363 | insn_info_t insn_info = bb_info->last_insn; |
fd6daec9 | 1364 | store_info *store_info = NULL; |
6fb5fa3c DB |
1365 | int group_id; |
1366 | cselib_val *base = NULL; | |
8dd5516b | 1367 | insn_info_t ptr, last, redundant_reason; |
6fb5fa3c DB |
1368 | bool store_is_unused; |
1369 | ||
1370 | if (GET_CODE (body) != SET && GET_CODE (body) != CLOBBER) | |
1371 | return 0; | |
1372 | ||
8dd5516b JJ |
1373 | mem = SET_DEST (body); |
1374 | ||
6fb5fa3c DB |
1375 | /* If this is not used, then this cannot be used to keep the insn |
1376 | from being deleted. On the other hand, it does provide something | |
1377 | that can be used to prove that another store is dead. */ | |
1378 | store_is_unused | |
8dd5516b | 1379 | = (find_reg_note (insn_info->insn, REG_UNUSED, mem) != NULL); |
6fb5fa3c DB |
1380 | |
1381 | /* Check whether that value is a suitable memory location. */ | |
6fb5fa3c DB |
1382 | if (!MEM_P (mem)) |
1383 | { | |
1384 | /* If the set or clobber is unused, then it does not effect our | |
1385 | ability to get rid of the entire insn. */ | |
1386 | if (!store_is_unused) | |
1387 | insn_info->cannot_delete = true; | |
1388 | return 0; | |
1389 | } | |
1390 | ||
1391 | /* At this point we know mem is a mem. */ | |
1392 | if (GET_MODE (mem) == BLKmode) | |
1393 | { | |
1394 | if (GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
1395 | { | |
456610d3 | 1396 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1397 | fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n"); |
1398 | add_wild_read (bb_info); | |
1399 | insn_info->cannot_delete = true; | |
8dd5516b | 1400 | return 0; |
6fb5fa3c | 1401 | } |
8dd5516b JJ |
1402 | /* Handle (set (mem:BLK (addr) [... S36 ...]) (const_int 0)) |
1403 | as memset (addr, 0, 36); */ | |
f5541398 RS |
1404 | else if (!MEM_SIZE_KNOWN_P (mem) |
1405 | || MEM_SIZE (mem) <= 0 | |
1406 | || MEM_SIZE (mem) > MAX_OFFSET | |
8dd5516b | 1407 | || GET_CODE (body) != SET |
8dd5516b | 1408 | || !CONST_INT_P (SET_SRC (body))) |
6fb5fa3c | 1409 | { |
8dd5516b JJ |
1410 | if (!store_is_unused) |
1411 | { | |
1412 | /* If the set or clobber is unused, then it does not effect our | |
1413 | ability to get rid of the entire insn. */ | |
1414 | insn_info->cannot_delete = true; | |
1415 | clear_rhs_from_active_local_stores (); | |
1416 | } | |
1417 | return 0; | |
6fb5fa3c | 1418 | } |
6fb5fa3c DB |
1419 | } |
1420 | ||
1421 | /* We can still process a volatile mem, we just cannot delete it. */ | |
1422 | if (MEM_VOLATILE_P (mem)) | |
8dd5516b | 1423 | insn_info->cannot_delete = true; |
6fb5fa3c DB |
1424 | |
1425 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
1426 | { | |
1427 | clear_rhs_from_active_local_stores (); | |
1428 | return 0; | |
1429 | } | |
1430 | ||
8dd5516b | 1431 | if (GET_MODE (mem) == BLKmode) |
f5541398 | 1432 | width = MEM_SIZE (mem); |
8dd5516b | 1433 | else |
6f557e0e | 1434 | width = GET_MODE_SIZE (GET_MODE (mem)); |
6fb5fa3c DB |
1435 | |
1436 | if (spill_alias_set) | |
1437 | { | |
1438 | bitmap store1 = clear_alias_group->store1_p; | |
1439 | bitmap store2 = clear_alias_group->store2_p; | |
8dd5516b JJ |
1440 | |
1441 | gcc_assert (GET_MODE (mem) != BLKmode); | |
b8698a0f | 1442 | |
fcaa4ca4 | 1443 | if (!bitmap_set_bit (store1, spill_alias_set)) |
6fb5fa3c | 1444 | bitmap_set_bit (store2, spill_alias_set); |
b8698a0f | 1445 | |
6fb5fa3c DB |
1446 | if (clear_alias_group->offset_map_size_p < spill_alias_set) |
1447 | clear_alias_group->offset_map_size_p = spill_alias_set; | |
b8698a0f | 1448 | |
da6603c6 | 1449 | store_info = rtx_store_info_pool.allocate (); |
6fb5fa3c | 1450 | |
456610d3 | 1451 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 1452 | fprintf (dump_file, " processing spill store %d(%s)\n", |
4862826d | 1453 | (int) spill_alias_set, GET_MODE_NAME (GET_MODE (mem))); |
6fb5fa3c DB |
1454 | } |
1455 | else if (group_id >= 0) | |
1456 | { | |
1457 | /* In the restrictive case where the base is a constant or the | |
1458 | frame pointer we can do global analysis. */ | |
b8698a0f | 1459 | |
fd6daec9 | 1460 | group_info *group |
9771b263 | 1461 | = rtx_group_vec[group_id]; |
d26c7090 | 1462 | tree expr = MEM_EXPR (mem); |
b8698a0f | 1463 | |
da6603c6 | 1464 | store_info = rtx_store_info_pool.allocate (); |
d26c7090 | 1465 | set_usage_bits (group, offset, width, expr); |
6fb5fa3c | 1466 | |
456610d3 | 1467 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1468 | fprintf (dump_file, " processing const base store gid=%d[%d..%d)\n", |
1469 | group_id, (int)offset, (int)(offset+width)); | |
1470 | } | |
1471 | else | |
1472 | { | |
9e412ca3 | 1473 | if (may_be_sp_based_p (XEXP (mem, 0))) |
50f0f366 | 1474 | insn_info->stack_pointer_based = true; |
6fb5fa3c | 1475 | insn_info->contains_cselib_groups = true; |
50f0f366 | 1476 | |
da6603c6 | 1477 | store_info = cse_store_info_pool.allocate (); |
6fb5fa3c DB |
1478 | group_id = -1; |
1479 | ||
456610d3 | 1480 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1481 | fprintf (dump_file, " processing cselib store [%d..%d)\n", |
1482 | (int)offset, (int)(offset+width)); | |
1483 | } | |
1484 | ||
8dd5516b JJ |
1485 | const_rhs = rhs = NULL_RTX; |
1486 | if (GET_CODE (body) == SET | |
1487 | /* No place to keep the value after ra. */ | |
1488 | && !reload_completed | |
1489 | && (REG_P (SET_SRC (body)) | |
1490 | || GET_CODE (SET_SRC (body)) == SUBREG | |
1491 | || CONSTANT_P (SET_SRC (body))) | |
1492 | && !MEM_VOLATILE_P (mem) | |
1493 | /* Sometimes the store and reload is used for truncation and | |
1494 | rounding. */ | |
1495 | && !(FLOAT_MODE_P (GET_MODE (mem)) && (flag_float_store))) | |
1496 | { | |
1497 | rhs = SET_SRC (body); | |
1498 | if (CONSTANT_P (rhs)) | |
1499 | const_rhs = rhs; | |
1500 | else if (body == PATTERN (insn_info->insn)) | |
1501 | { | |
1502 | rtx tem = find_reg_note (insn_info->insn, REG_EQUAL, NULL_RTX); | |
1503 | if (tem && CONSTANT_P (XEXP (tem, 0))) | |
1504 | const_rhs = XEXP (tem, 0); | |
1505 | } | |
1506 | if (const_rhs == NULL_RTX && REG_P (rhs)) | |
1507 | { | |
1508 | rtx tem = cselib_expand_value_rtx (rhs, scratch, 5); | |
1509 | ||
1510 | if (tem && CONSTANT_P (tem)) | |
1511 | const_rhs = tem; | |
1512 | } | |
1513 | } | |
1514 | ||
6fb5fa3c DB |
1515 | /* Check to see if this stores causes some other stores to be |
1516 | dead. */ | |
1517 | ptr = active_local_stores; | |
1518 | last = NULL; | |
8dd5516b | 1519 | redundant_reason = NULL; |
6216f94e JJ |
1520 | mem = canon_rtx (mem); |
1521 | /* For alias_set != 0 canon_true_dependence should be never called. */ | |
1522 | if (spill_alias_set) | |
1523 | mem_addr = NULL_RTX; | |
1524 | else | |
1525 | { | |
1526 | if (group_id < 0) | |
1527 | mem_addr = base->val_rtx; | |
1528 | else | |
1529 | { | |
fd6daec9 | 1530 | group_info *group |
9771b263 | 1531 | = rtx_group_vec[group_id]; |
6216f94e JJ |
1532 | mem_addr = group->canon_base_addr; |
1533 | } | |
ff1803c1 WM |
1534 | /* get_addr can only handle VALUE but cannot handle expr like: |
1535 | VALUE + OFFSET, so call get_addr to get original addr for | |
1536 | mem_addr before plus_constant. */ | |
1537 | mem_addr = get_addr (mem_addr); | |
6216f94e | 1538 | if (offset) |
372d6395 | 1539 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
6216f94e | 1540 | } |
6fb5fa3c DB |
1541 | |
1542 | while (ptr) | |
1543 | { | |
1544 | insn_info_t next = ptr->next_local_store; | |
fd6daec9 | 1545 | struct store_info *s_info = ptr->store_rec; |
60564289 | 1546 | bool del = true; |
6fb5fa3c DB |
1547 | |
1548 | /* Skip the clobbers. We delete the active insn if this insn | |
6ed3da00 | 1549 | shadows the set. To have been put on the active list, it |
6fb5fa3c DB |
1550 | has exactly on set. */ |
1551 | while (!s_info->is_set) | |
1552 | s_info = s_info->next; | |
1553 | ||
1554 | if (s_info->alias_set != spill_alias_set) | |
60564289 | 1555 | del = false; |
6fb5fa3c DB |
1556 | else if (s_info->alias_set) |
1557 | { | |
b8698a0f | 1558 | struct clear_alias_mode_holder *entry |
6fb5fa3c DB |
1559 | = clear_alias_set_lookup (s_info->alias_set); |
1560 | /* Generally, spills cannot be processed if and of the | |
1561 | references to the slot have a different mode. But if | |
1562 | we are in the same block and mode is exactly the same | |
1563 | between this store and one before in the same block, | |
1564 | we can still delete it. */ | |
1565 | if ((GET_MODE (mem) == GET_MODE (s_info->mem)) | |
1566 | && (GET_MODE (mem) == entry->mode)) | |
1567 | { | |
60564289 | 1568 | del = true; |
8dd5516b | 1569 | set_all_positions_unneeded (s_info); |
6fb5fa3c | 1570 | } |
456610d3 | 1571 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 1572 | fprintf (dump_file, " trying spill store in insn=%d alias_set=%d\n", |
4862826d | 1573 | INSN_UID (ptr->insn), (int) s_info->alias_set); |
6fb5fa3c | 1574 | } |
b8698a0f | 1575 | else if ((s_info->group_id == group_id) |
6fb5fa3c DB |
1576 | && (s_info->cse_base == base)) |
1577 | { | |
1578 | HOST_WIDE_INT i; | |
456610d3 | 1579 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 1580 | fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n", |
b8698a0f | 1581 | INSN_UID (ptr->insn), s_info->group_id, |
6fb5fa3c | 1582 | (int)s_info->begin, (int)s_info->end); |
8dd5516b JJ |
1583 | |
1584 | /* Even if PTR won't be eliminated as unneeded, if both | |
1585 | PTR and this insn store the same constant value, we might | |
1586 | eliminate this insn instead. */ | |
1587 | if (s_info->const_rhs | |
1588 | && const_rhs | |
1589 | && offset >= s_info->begin | |
1590 | && offset + width <= s_info->end | |
1591 | && all_positions_needed_p (s_info, offset - s_info->begin, | |
1592 | width)) | |
1593 | { | |
1594 | if (GET_MODE (mem) == BLKmode) | |
1595 | { | |
1596 | if (GET_MODE (s_info->mem) == BLKmode | |
1597 | && s_info->const_rhs == const_rhs) | |
1598 | redundant_reason = ptr; | |
1599 | } | |
1600 | else if (s_info->const_rhs == const0_rtx | |
1601 | && const_rhs == const0_rtx) | |
1602 | redundant_reason = ptr; | |
1603 | else | |
1604 | { | |
1605 | rtx val; | |
1606 | start_sequence (); | |
1607 | val = get_stored_val (s_info, GET_MODE (mem), | |
1608 | offset, offset + width, | |
1609 | BLOCK_FOR_INSN (insn_info->insn), | |
1610 | true); | |
1611 | if (get_insns () != NULL) | |
1612 | val = NULL_RTX; | |
1613 | end_sequence (); | |
1614 | if (val && rtx_equal_p (val, const_rhs)) | |
1615 | redundant_reason = ptr; | |
1616 | } | |
1617 | } | |
1618 | ||
1619 | for (i = MAX (offset, s_info->begin); | |
1620 | i < offset + width && i < s_info->end; | |
1621 | i++) | |
1622 | set_position_unneeded (s_info, i - s_info->begin); | |
6fb5fa3c DB |
1623 | } |
1624 | else if (s_info->rhs) | |
1625 | /* Need to see if it is possible for this store to overwrite | |
1626 | the value of store_info. If it is, set the rhs to NULL to | |
1627 | keep it from being used to remove a load. */ | |
1628 | { | |
b8698a0f | 1629 | if (canon_true_dependence (s_info->mem, |
6fb5fa3c DB |
1630 | GET_MODE (s_info->mem), |
1631 | s_info->mem_addr, | |
53d9622b | 1632 | mem, mem_addr)) |
8dd5516b JJ |
1633 | { |
1634 | s_info->rhs = NULL; | |
1635 | s_info->const_rhs = NULL; | |
1636 | } | |
6fb5fa3c | 1637 | } |
6216f94e | 1638 | |
6fb5fa3c DB |
1639 | /* An insn can be deleted if every position of every one of |
1640 | its s_infos is zero. */ | |
1b6fa860 | 1641 | if (any_positions_needed_p (s_info)) |
60564289 | 1642 | del = false; |
8dd5516b | 1643 | |
60564289 | 1644 | if (del) |
6fb5fa3c DB |
1645 | { |
1646 | insn_info_t insn_to_delete = ptr; | |
b8698a0f | 1647 | |
dabd47e7 | 1648 | active_local_stores_len--; |
6fb5fa3c DB |
1649 | if (last) |
1650 | last->next_local_store = ptr->next_local_store; | |
1651 | else | |
1652 | active_local_stores = ptr->next_local_store; | |
b8698a0f | 1653 | |
1b6fa860 JJ |
1654 | if (!insn_to_delete->cannot_delete) |
1655 | delete_dead_store_insn (insn_to_delete); | |
6fb5fa3c DB |
1656 | } |
1657 | else | |
1658 | last = ptr; | |
b8698a0f | 1659 | |
6fb5fa3c DB |
1660 | ptr = next; |
1661 | } | |
b8698a0f | 1662 | |
6fb5fa3c DB |
1663 | /* Finish filling in the store_info. */ |
1664 | store_info->next = insn_info->store_rec; | |
1665 | insn_info->store_rec = store_info; | |
6216f94e | 1666 | store_info->mem = mem; |
6fb5fa3c | 1667 | store_info->alias_set = spill_alias_set; |
6216f94e | 1668 | store_info->mem_addr = mem_addr; |
6fb5fa3c | 1669 | store_info->cse_base = base; |
8dd5516b JJ |
1670 | if (width > HOST_BITS_PER_WIDE_INT) |
1671 | { | |
1672 | store_info->is_large = true; | |
1673 | store_info->positions_needed.large.count = 0; | |
3f9b14ff | 1674 | store_info->positions_needed.large.bmap = BITMAP_ALLOC (&dse_bitmap_obstack); |
8dd5516b JJ |
1675 | } |
1676 | else | |
1677 | { | |
1678 | store_info->is_large = false; | |
1679 | store_info->positions_needed.small_bitmask = lowpart_bitmask (width); | |
1680 | } | |
6fb5fa3c DB |
1681 | store_info->group_id = group_id; |
1682 | store_info->begin = offset; | |
1683 | store_info->end = offset + width; | |
1684 | store_info->is_set = GET_CODE (body) == SET; | |
8dd5516b JJ |
1685 | store_info->rhs = rhs; |
1686 | store_info->const_rhs = const_rhs; | |
1687 | store_info->redundant_reason = redundant_reason; | |
6fb5fa3c | 1688 | |
6fb5fa3c DB |
1689 | /* If this is a clobber, we return 0. We will only be able to |
1690 | delete this insn if there is only one store USED store, but we | |
1691 | can use the clobber to delete other stores earlier. */ | |
1692 | return store_info->is_set ? 1 : 0; | |
1693 | } | |
1694 | ||
1695 | ||
1696 | static void | |
1697 | dump_insn_info (const char * start, insn_info_t insn_info) | |
1698 | { | |
b8698a0f | 1699 | fprintf (dump_file, "%s insn=%d %s\n", start, |
6fb5fa3c DB |
1700 | INSN_UID (insn_info->insn), |
1701 | insn_info->store_rec ? "has store" : "naked"); | |
1702 | } | |
1703 | ||
1704 | ||
8660aaae EC |
1705 | /* If the modes are different and the value's source and target do not |
1706 | line up, we need to extract the value from lower part of the rhs of | |
1707 | the store, shift it, and then put it into a form that can be shoved | |
1708 | into the read_insn. This function generates a right SHIFT of a | |
1709 | value that is at least ACCESS_SIZE bytes wide of READ_MODE. The | |
1710 | shift sequence is returned or NULL if we failed to find a | |
1711 | shift. */ | |
1712 | ||
1713 | static rtx | |
18b526e8 | 1714 | find_shift_sequence (int access_size, |
fd6daec9 | 1715 | store_info *store_info, |
ef4bddc2 | 1716 | machine_mode read_mode, |
8dd5516b | 1717 | int shift, bool speed, bool require_cst) |
8660aaae | 1718 | { |
ef4bddc2 RS |
1719 | machine_mode store_mode = GET_MODE (store_info->mem); |
1720 | machine_mode new_mode; | |
18b526e8 | 1721 | rtx read_reg = NULL; |
8660aaae EC |
1722 | |
1723 | /* Some machines like the x86 have shift insns for each size of | |
1724 | operand. Other machines like the ppc or the ia-64 may only have | |
1725 | shift insns that shift values within 32 or 64 bit registers. | |
1726 | This loop tries to find the smallest shift insn that will right | |
1727 | justify the value we want to read but is available in one insn on | |
1728 | the machine. */ | |
1729 | ||
18b526e8 RS |
1730 | for (new_mode = smallest_mode_for_size (access_size * BITS_PER_UNIT, |
1731 | MODE_INT); | |
1732 | GET_MODE_BITSIZE (new_mode) <= BITS_PER_WORD; | |
1733 | new_mode = GET_MODE_WIDER_MODE (new_mode)) | |
8660aaae | 1734 | { |
dc01c3d1 DM |
1735 | rtx target, new_reg, new_lhs; |
1736 | rtx_insn *shift_seq, *insn; | |
d898d29b | 1737 | int cost; |
348eea5f | 1738 | |
72a2609f JJ |
1739 | /* If a constant was stored into memory, try to simplify it here, |
1740 | otherwise the cost of the shift might preclude this optimization | |
1741 | e.g. at -Os, even when no actual shift will be needed. */ | |
8dd5516b | 1742 | if (store_info->const_rhs) |
72a2609f JJ |
1743 | { |
1744 | unsigned int byte = subreg_lowpart_offset (new_mode, store_mode); | |
8dd5516b JJ |
1745 | rtx ret = simplify_subreg (new_mode, store_info->const_rhs, |
1746 | store_mode, byte); | |
72a2609f JJ |
1747 | if (ret && CONSTANT_P (ret)) |
1748 | { | |
1749 | ret = simplify_const_binary_operation (LSHIFTRT, new_mode, | |
1750 | ret, GEN_INT (shift)); | |
1751 | if (ret && CONSTANT_P (ret)) | |
1752 | { | |
1753 | byte = subreg_lowpart_offset (read_mode, new_mode); | |
1754 | ret = simplify_subreg (read_mode, ret, new_mode, byte); | |
1755 | if (ret && CONSTANT_P (ret) | |
e548c9df AM |
1756 | && (set_src_cost (ret, read_mode, speed) |
1757 | <= COSTS_N_INSNS (1))) | |
72a2609f JJ |
1758 | return ret; |
1759 | } | |
1760 | } | |
1761 | } | |
1762 | ||
8dd5516b JJ |
1763 | if (require_cst) |
1764 | return NULL_RTX; | |
1765 | ||
18b526e8 RS |
1766 | /* Try a wider mode if truncating the store mode to NEW_MODE |
1767 | requires a real instruction. */ | |
1768 | if (GET_MODE_BITSIZE (new_mode) < GET_MODE_BITSIZE (store_mode) | |
d0edd768 | 1769 | && !TRULY_NOOP_TRUNCATION_MODES_P (new_mode, store_mode)) |
348eea5f RS |
1770 | continue; |
1771 | ||
18b526e8 RS |
1772 | /* Also try a wider mode if the necessary punning is either not |
1773 | desirable or not possible. */ | |
1774 | if (!CONSTANT_P (store_info->rhs) | |
1775 | && !MODES_TIEABLE_P (new_mode, store_mode)) | |
1776 | continue; | |
18b526e8 | 1777 | |
348eea5f | 1778 | new_reg = gen_reg_rtx (new_mode); |
8660aaae EC |
1779 | |
1780 | start_sequence (); | |
1781 | ||
1782 | /* In theory we could also check for an ashr. Ian Taylor knows | |
1783 | of one dsp where the cost of these two was not the same. But | |
1784 | this really is a rare case anyway. */ | |
1785 | target = expand_binop (new_mode, lshr_optab, new_reg, | |
1786 | GEN_INT (shift), new_reg, 1, OPTAB_DIRECT); | |
1787 | ||
c6f3019a RS |
1788 | shift_seq = get_insns (); |
1789 | end_sequence (); | |
8660aaae | 1790 | |
c6f3019a RS |
1791 | if (target != new_reg || shift_seq == NULL) |
1792 | continue; | |
1793 | ||
1794 | cost = 0; | |
1795 | for (insn = shift_seq; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
1796 | if (INSN_P (insn)) | |
f40751dd | 1797 | cost += insn_rtx_cost (PATTERN (insn), speed); |
c6f3019a RS |
1798 | |
1799 | /* The computation up to here is essentially independent | |
1800 | of the arguments and could be precomputed. It may | |
1801 | not be worth doing so. We could precompute if | |
1802 | worthwhile or at least cache the results. The result | |
06acf7d0 RS |
1803 | technically depends on both SHIFT and ACCESS_SIZE, |
1804 | but in practice the answer will depend only on ACCESS_SIZE. */ | |
c6f3019a RS |
1805 | |
1806 | if (cost > COSTS_N_INSNS (1)) | |
1807 | continue; | |
1808 | ||
d898d29b JJ |
1809 | new_lhs = extract_low_bits (new_mode, store_mode, |
1810 | copy_rtx (store_info->rhs)); | |
1811 | if (new_lhs == NULL_RTX) | |
1812 | continue; | |
1813 | ||
c6f3019a RS |
1814 | /* We found an acceptable shift. Generate a move to |
1815 | take the value from the store and put it into the | |
1816 | shift pseudo, then shift it, then generate another | |
1817 | move to put in into the target of the read. */ | |
18b526e8 | 1818 | emit_move_insn (new_reg, new_lhs); |
c6f3019a | 1819 | emit_insn (shift_seq); |
18b526e8 | 1820 | read_reg = extract_low_bits (read_mode, new_mode, new_reg); |
c6f3019a | 1821 | break; |
8660aaae EC |
1822 | } |
1823 | ||
18b526e8 | 1824 | return read_reg; |
8660aaae EC |
1825 | } |
1826 | ||
1827 | ||
02b47899 KZ |
1828 | /* Call back for note_stores to find the hard regs set or clobbered by |
1829 | insn. Data is a bitmap of the hardregs set so far. */ | |
1830 | ||
1831 | static void | |
1832 | look_for_hardregs (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) | |
1833 | { | |
1834 | bitmap regs_set = (bitmap) data; | |
1835 | ||
1836 | if (REG_P (x) | |
f773c2bd | 1837 | && HARD_REGISTER_P (x)) |
dc8afb70 | 1838 | bitmap_set_range (regs_set, REGNO (x), REG_NREGS (x)); |
02b47899 KZ |
1839 | } |
1840 | ||
8dd5516b JJ |
1841 | /* Helper function for replace_read and record_store. |
1842 | Attempt to return a value stored in STORE_INFO, from READ_BEGIN | |
1843 | to one before READ_END bytes read in READ_MODE. Return NULL | |
1844 | if not successful. If REQUIRE_CST is true, return always constant. */ | |
1845 | ||
1846 | static rtx | |
fd6daec9 | 1847 | get_stored_val (store_info *store_info, machine_mode read_mode, |
8dd5516b JJ |
1848 | HOST_WIDE_INT read_begin, HOST_WIDE_INT read_end, |
1849 | basic_block bb, bool require_cst) | |
1850 | { | |
ef4bddc2 | 1851 | machine_mode store_mode = GET_MODE (store_info->mem); |
8dd5516b JJ |
1852 | int shift; |
1853 | int access_size; /* In bytes. */ | |
1854 | rtx read_reg; | |
1855 | ||
1856 | /* To get here the read is within the boundaries of the write so | |
1857 | shift will never be negative. Start out with the shift being in | |
1858 | bytes. */ | |
1859 | if (store_mode == BLKmode) | |
1860 | shift = 0; | |
1861 | else if (BYTES_BIG_ENDIAN) | |
1862 | shift = store_info->end - read_end; | |
1863 | else | |
1864 | shift = read_begin - store_info->begin; | |
1865 | ||
1866 | access_size = shift + GET_MODE_SIZE (read_mode); | |
1867 | ||
1868 | /* From now on it is bits. */ | |
1869 | shift *= BITS_PER_UNIT; | |
1870 | ||
1871 | if (shift) | |
1872 | read_reg = find_shift_sequence (access_size, store_info, read_mode, shift, | |
1873 | optimize_bb_for_speed_p (bb), | |
1874 | require_cst); | |
1875 | else if (store_mode == BLKmode) | |
1876 | { | |
1877 | /* The store is a memset (addr, const_val, const_size). */ | |
1878 | gcc_assert (CONST_INT_P (store_info->rhs)); | |
1879 | store_mode = int_mode_for_mode (read_mode); | |
1880 | if (store_mode == BLKmode) | |
1881 | read_reg = NULL_RTX; | |
1882 | else if (store_info->rhs == const0_rtx) | |
1883 | read_reg = extract_low_bits (read_mode, store_mode, const0_rtx); | |
1884 | else if (GET_MODE_BITSIZE (store_mode) > HOST_BITS_PER_WIDE_INT | |
1885 | || BITS_PER_UNIT >= HOST_BITS_PER_WIDE_INT) | |
1886 | read_reg = NULL_RTX; | |
1887 | else | |
1888 | { | |
1889 | unsigned HOST_WIDE_INT c | |
1890 | = INTVAL (store_info->rhs) | |
1891 | & (((HOST_WIDE_INT) 1 << BITS_PER_UNIT) - 1); | |
1892 | int shift = BITS_PER_UNIT; | |
1893 | while (shift < HOST_BITS_PER_WIDE_INT) | |
1894 | { | |
1895 | c |= (c << shift); | |
1896 | shift <<= 1; | |
1897 | } | |
6d26322f | 1898 | read_reg = gen_int_mode (c, store_mode); |
8dd5516b JJ |
1899 | read_reg = extract_low_bits (read_mode, store_mode, read_reg); |
1900 | } | |
1901 | } | |
1902 | else if (store_info->const_rhs | |
1903 | && (require_cst | |
1904 | || GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))) | |
1905 | read_reg = extract_low_bits (read_mode, store_mode, | |
1906 | copy_rtx (store_info->const_rhs)); | |
1907 | else | |
1908 | read_reg = extract_low_bits (read_mode, store_mode, | |
1909 | copy_rtx (store_info->rhs)); | |
1910 | if (require_cst && read_reg && !CONSTANT_P (read_reg)) | |
1911 | read_reg = NULL_RTX; | |
1912 | return read_reg; | |
1913 | } | |
02b47899 | 1914 | |
6fb5fa3c DB |
1915 | /* Take a sequence of: |
1916 | A <- r1 | |
1917 | ... | |
1918 | ... <- A | |
1919 | ||
b8698a0f | 1920 | and change it into |
6fb5fa3c DB |
1921 | r2 <- r1 |
1922 | A <- r1 | |
1923 | ... | |
1924 | ... <- r2 | |
1925 | ||
8660aaae EC |
1926 | or |
1927 | ||
1928 | r3 <- extract (r1) | |
1929 | r3 <- r3 >> shift | |
1930 | r2 <- extract (r3) | |
1931 | ... <- r2 | |
1932 | ||
1933 | or | |
1934 | ||
1935 | r2 <- extract (r1) | |
1936 | ... <- r2 | |
1937 | ||
1938 | Depending on the alignment and the mode of the store and | |
1939 | subsequent load. | |
1940 | ||
1941 | ||
1942 | The STORE_INFO and STORE_INSN are for the store and READ_INFO | |
6fb5fa3c DB |
1943 | and READ_INSN are for the read. Return true if the replacement |
1944 | went ok. */ | |
1945 | ||
1946 | static bool | |
fd6daec9 | 1947 | replace_read (store_info *store_info, insn_info_t store_insn, |
8dd5516b JJ |
1948 | read_info_t read_info, insn_info_t read_insn, rtx *loc, |
1949 | bitmap regs_live) | |
6fb5fa3c | 1950 | { |
ef4bddc2 RS |
1951 | machine_mode store_mode = GET_MODE (store_info->mem); |
1952 | machine_mode read_mode = GET_MODE (read_info->mem); | |
dc01c3d1 DM |
1953 | rtx_insn *insns, *this_insn; |
1954 | rtx read_reg; | |
8dd5516b | 1955 | basic_block bb; |
8660aaae | 1956 | |
6fb5fa3c DB |
1957 | if (!dbg_cnt (dse)) |
1958 | return false; | |
1959 | ||
18b526e8 RS |
1960 | /* Create a sequence of instructions to set up the read register. |
1961 | This sequence goes immediately before the store and its result | |
1962 | is read by the load. | |
1963 | ||
1964 | We need to keep this in perspective. We are replacing a read | |
8660aaae EC |
1965 | with a sequence of insns, but the read will almost certainly be |
1966 | in cache, so it is not going to be an expensive one. Thus, we | |
1967 | are not willing to do a multi insn shift or worse a subroutine | |
1968 | call to get rid of the read. */ | |
456610d3 | 1969 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1970 | fprintf (dump_file, "trying to replace %smode load in insn %d" |
1971 | " from %smode store in insn %d\n", | |
1972 | GET_MODE_NAME (read_mode), INSN_UID (read_insn->insn), | |
1973 | GET_MODE_NAME (store_mode), INSN_UID (store_insn->insn)); | |
1974 | start_sequence (); | |
8dd5516b JJ |
1975 | bb = BLOCK_FOR_INSN (read_insn->insn); |
1976 | read_reg = get_stored_val (store_info, | |
1977 | read_mode, read_info->begin, read_info->end, | |
1978 | bb, false); | |
18b526e8 | 1979 | if (read_reg == NULL_RTX) |
8660aaae | 1980 | { |
18b526e8 | 1981 | end_sequence (); |
456610d3 | 1982 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1983 | fprintf (dump_file, " -- could not extract bits of stored value\n"); |
1984 | return false; | |
8660aaae | 1985 | } |
18b526e8 RS |
1986 | /* Force the value into a new register so that it won't be clobbered |
1987 | between the store and the load. */ | |
1988 | read_reg = copy_to_mode_reg (read_mode, read_reg); | |
1989 | insns = get_insns (); | |
1990 | end_sequence (); | |
8660aaae | 1991 | |
02b47899 KZ |
1992 | if (insns != NULL_RTX) |
1993 | { | |
1994 | /* Now we have to scan the set of new instructions to see if the | |
1995 | sequence contains and sets of hardregs that happened to be | |
1996 | live at this point. For instance, this can happen if one of | |
1997 | the insns sets the CC and the CC happened to be live at that | |
1998 | point. This does occasionally happen, see PR 37922. */ | |
3f9b14ff | 1999 | bitmap regs_set = BITMAP_ALLOC (®_obstack); |
02b47899 KZ |
2000 | |
2001 | for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn)) | |
2002 | note_stores (PATTERN (this_insn), look_for_hardregs, regs_set); | |
b8698a0f | 2003 | |
02b47899 KZ |
2004 | bitmap_and_into (regs_set, regs_live); |
2005 | if (!bitmap_empty_p (regs_set)) | |
2006 | { | |
456610d3 | 2007 | if (dump_file && (dump_flags & TDF_DETAILS)) |
02b47899 | 2008 | { |
b8698a0f | 2009 | fprintf (dump_file, |
02b47899 KZ |
2010 | "abandoning replacement because sequence clobbers live hardregs:"); |
2011 | df_print_regset (dump_file, regs_set); | |
2012 | } | |
b8698a0f | 2013 | |
02b47899 KZ |
2014 | BITMAP_FREE (regs_set); |
2015 | return false; | |
2016 | } | |
2017 | BITMAP_FREE (regs_set); | |
2018 | } | |
2019 | ||
8660aaae | 2020 | if (validate_change (read_insn->insn, loc, read_reg, 0)) |
6fb5fa3c | 2021 | { |
fd6daec9 | 2022 | deferred_change *change = deferred_change_pool.allocate (); |
b8698a0f | 2023 | |
8660aaae EC |
2024 | /* Insert this right before the store insn where it will be safe |
2025 | from later insns that might change it before the read. */ | |
2026 | emit_insn_before (insns, store_insn->insn); | |
b8698a0f | 2027 | |
8660aaae EC |
2028 | /* And now for the kludge part: cselib croaks if you just |
2029 | return at this point. There are two reasons for this: | |
b8698a0f | 2030 | |
8660aaae EC |
2031 | 1) Cselib has an idea of how many pseudos there are and |
2032 | that does not include the new ones we just added. | |
b8698a0f | 2033 | |
8660aaae EC |
2034 | 2) Cselib does not know about the move insn we added |
2035 | above the store_info, and there is no way to tell it | |
2036 | about it, because it has "moved on". | |
b8698a0f | 2037 | |
8660aaae EC |
2038 | Problem (1) is fixable with a certain amount of engineering. |
2039 | Problem (2) is requires starting the bb from scratch. This | |
2040 | could be expensive. | |
b8698a0f | 2041 | |
8660aaae EC |
2042 | So we are just going to have to lie. The move/extraction |
2043 | insns are not really an issue, cselib did not see them. But | |
2044 | the use of the new pseudo read_insn is a real problem because | |
2045 | cselib has not scanned this insn. The way that we solve this | |
2046 | problem is that we are just going to put the mem back for now | |
2047 | and when we are finished with the block, we undo this. We | |
2048 | keep a table of mems to get rid of. At the end of the basic | |
2049 | block we can put them back. */ | |
b8698a0f | 2050 | |
8660aaae | 2051 | *loc = read_info->mem; |
da6603c6 ML |
2052 | change->next = deferred_change_list; |
2053 | deferred_change_list = change; | |
2054 | change->loc = loc; | |
2055 | change->reg = read_reg; | |
b8698a0f | 2056 | |
8660aaae EC |
2057 | /* Get rid of the read_info, from the point of view of the |
2058 | rest of dse, play like this read never happened. */ | |
2059 | read_insn->read_rec = read_info->next; | |
fb0b2914 | 2060 | read_info_type_pool.remove (read_info); |
456610d3 | 2061 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
2062 | { |
2063 | fprintf (dump_file, " -- replaced the loaded MEM with "); | |
2064 | print_simple_rtl (dump_file, read_reg); | |
2065 | fprintf (dump_file, "\n"); | |
2066 | } | |
8660aaae | 2067 | return true; |
6fb5fa3c | 2068 | } |
b8698a0f | 2069 | else |
6fb5fa3c | 2070 | { |
456610d3 | 2071 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
2072 | { |
2073 | fprintf (dump_file, " -- replacing the loaded MEM with "); | |
2074 | print_simple_rtl (dump_file, read_reg); | |
2075 | fprintf (dump_file, " led to an invalid instruction\n"); | |
2076 | } | |
6fb5fa3c DB |
2077 | return false; |
2078 | } | |
2079 | } | |
2080 | ||
d7111da8 RS |
2081 | /* Check the address of MEM *LOC and kill any appropriate stores that may |
2082 | be active. */ | |
6fb5fa3c | 2083 | |
d7111da8 RS |
2084 | static void |
2085 | check_mem_read_rtx (rtx *loc, bb_info_t bb_info) | |
6fb5fa3c | 2086 | { |
6216f94e | 2087 | rtx mem = *loc, mem_addr; |
6fb5fa3c DB |
2088 | insn_info_t insn_info; |
2089 | HOST_WIDE_INT offset = 0; | |
2090 | HOST_WIDE_INT width = 0; | |
4862826d | 2091 | alias_set_type spill_alias_set = 0; |
b8698a0f | 2092 | cselib_val *base = NULL; |
6fb5fa3c DB |
2093 | int group_id; |
2094 | read_info_t read_info; | |
2095 | ||
6fb5fa3c DB |
2096 | insn_info = bb_info->last_insn; |
2097 | ||
2098 | if ((MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2099 | || (MEM_VOLATILE_P (mem))) | |
2100 | { | |
456610d3 | 2101 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2102 | fprintf (dump_file, " adding wild read, volatile or barrier.\n"); |
2103 | add_wild_read (bb_info); | |
2104 | insn_info->cannot_delete = true; | |
d7111da8 | 2105 | return; |
6fb5fa3c DB |
2106 | } |
2107 | ||
2108 | /* If it is reading readonly mem, then there can be no conflict with | |
2109 | another write. */ | |
2110 | if (MEM_READONLY_P (mem)) | |
d7111da8 | 2111 | return; |
6fb5fa3c DB |
2112 | |
2113 | if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base)) | |
2114 | { | |
456610d3 | 2115 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2116 | fprintf (dump_file, " adding wild read, canon_address failure.\n"); |
2117 | add_wild_read (bb_info); | |
d7111da8 | 2118 | return; |
6fb5fa3c DB |
2119 | } |
2120 | ||
2121 | if (GET_MODE (mem) == BLKmode) | |
2122 | width = -1; | |
2123 | else | |
2124 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
2125 | ||
fb0b2914 | 2126 | read_info = read_info_type_pool.allocate (); |
6fb5fa3c DB |
2127 | read_info->group_id = group_id; |
2128 | read_info->mem = mem; | |
2129 | read_info->alias_set = spill_alias_set; | |
2130 | read_info->begin = offset; | |
2131 | read_info->end = offset + width; | |
2132 | read_info->next = insn_info->read_rec; | |
2133 | insn_info->read_rec = read_info; | |
6216f94e JJ |
2134 | /* For alias_set != 0 canon_true_dependence should be never called. */ |
2135 | if (spill_alias_set) | |
2136 | mem_addr = NULL_RTX; | |
2137 | else | |
2138 | { | |
2139 | if (group_id < 0) | |
2140 | mem_addr = base->val_rtx; | |
2141 | else | |
2142 | { | |
fd6daec9 | 2143 | group_info *group |
9771b263 | 2144 | = rtx_group_vec[group_id]; |
6216f94e JJ |
2145 | mem_addr = group->canon_base_addr; |
2146 | } | |
ff1803c1 WM |
2147 | /* get_addr can only handle VALUE but cannot handle expr like: |
2148 | VALUE + OFFSET, so call get_addr to get original addr for | |
2149 | mem_addr before plus_constant. */ | |
2150 | mem_addr = get_addr (mem_addr); | |
6216f94e | 2151 | if (offset) |
372d6395 | 2152 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); |
6216f94e | 2153 | } |
6fb5fa3c | 2154 | |
0d52bcc1 | 2155 | /* We ignore the clobbers in store_info. The is mildly aggressive, |
6fb5fa3c DB |
2156 | but there really should not be a clobber followed by a read. */ |
2157 | ||
2158 | if (spill_alias_set) | |
2159 | { | |
2160 | insn_info_t i_ptr = active_local_stores; | |
2161 | insn_info_t last = NULL; | |
2162 | ||
456610d3 | 2163 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2164 | fprintf (dump_file, " processing spill load %d\n", |
4862826d | 2165 | (int) spill_alias_set); |
6fb5fa3c DB |
2166 | |
2167 | while (i_ptr) | |
2168 | { | |
fd6daec9 | 2169 | store_info *store_info = i_ptr->store_rec; |
6fb5fa3c DB |
2170 | |
2171 | /* Skip the clobbers. */ | |
2172 | while (!store_info->is_set) | |
2173 | store_info = store_info->next; | |
b8698a0f | 2174 | |
6fb5fa3c DB |
2175 | if (store_info->alias_set == spill_alias_set) |
2176 | { | |
456610d3 | 2177 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2178 | dump_insn_info ("removing from active", i_ptr); |
2179 | ||
dabd47e7 | 2180 | active_local_stores_len--; |
6fb5fa3c DB |
2181 | if (last) |
2182 | last->next_local_store = i_ptr->next_local_store; | |
2183 | else | |
2184 | active_local_stores = i_ptr->next_local_store; | |
2185 | } | |
2186 | else | |
2187 | last = i_ptr; | |
2188 | i_ptr = i_ptr->next_local_store; | |
2189 | } | |
2190 | } | |
2191 | else if (group_id >= 0) | |
2192 | { | |
2193 | /* This is the restricted case where the base is a constant or | |
2194 | the frame pointer and offset is a constant. */ | |
2195 | insn_info_t i_ptr = active_local_stores; | |
2196 | insn_info_t last = NULL; | |
b8698a0f | 2197 | |
456610d3 | 2198 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2199 | { |
2200 | if (width == -1) | |
2201 | fprintf (dump_file, " processing const load gid=%d[BLK]\n", | |
2202 | group_id); | |
2203 | else | |
2204 | fprintf (dump_file, " processing const load gid=%d[%d..%d)\n", | |
2205 | group_id, (int)offset, (int)(offset+width)); | |
2206 | } | |
2207 | ||
2208 | while (i_ptr) | |
2209 | { | |
2210 | bool remove = false; | |
fd6daec9 | 2211 | store_info *store_info = i_ptr->store_rec; |
b8698a0f | 2212 | |
6fb5fa3c DB |
2213 | /* Skip the clobbers. */ |
2214 | while (!store_info->is_set) | |
2215 | store_info = store_info->next; | |
b8698a0f | 2216 | |
6fb5fa3c DB |
2217 | /* There are three cases here. */ |
2218 | if (store_info->group_id < 0) | |
2219 | /* We have a cselib store followed by a read from a | |
2220 | const base. */ | |
b8698a0f L |
2221 | remove |
2222 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2223 | GET_MODE (store_info->mem), |
2224 | store_info->mem_addr, | |
53d9622b | 2225 | mem, mem_addr); |
b8698a0f | 2226 | |
6fb5fa3c DB |
2227 | else if (group_id == store_info->group_id) |
2228 | { | |
2229 | /* This is a block mode load. We may get lucky and | |
2230 | canon_true_dependence may save the day. */ | |
2231 | if (width == -1) | |
b8698a0f L |
2232 | remove |
2233 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2234 | GET_MODE (store_info->mem), |
2235 | store_info->mem_addr, | |
53d9622b | 2236 | mem, mem_addr); |
b8698a0f | 2237 | |
6fb5fa3c DB |
2238 | /* If this read is just reading back something that we just |
2239 | stored, rewrite the read. */ | |
b8698a0f | 2240 | else |
6fb5fa3c DB |
2241 | { |
2242 | if (store_info->rhs | |
8dd5516b JJ |
2243 | && offset >= store_info->begin |
2244 | && offset + width <= store_info->end | |
2245 | && all_positions_needed_p (store_info, | |
2246 | offset - store_info->begin, | |
2247 | width) | |
2248 | && replace_read (store_info, i_ptr, read_info, | |
2249 | insn_info, loc, bb_info->regs_live)) | |
d7111da8 | 2250 | return; |
8dd5516b | 2251 | |
6fb5fa3c DB |
2252 | /* The bases are the same, just see if the offsets |
2253 | overlap. */ | |
b8698a0f | 2254 | if ((offset < store_info->end) |
6fb5fa3c DB |
2255 | && (offset + width > store_info->begin)) |
2256 | remove = true; | |
2257 | } | |
2258 | } | |
b8698a0f L |
2259 | |
2260 | /* else | |
6fb5fa3c DB |
2261 | The else case that is missing here is that the |
2262 | bases are constant but different. There is nothing | |
2263 | to do here because there is no overlap. */ | |
b8698a0f | 2264 | |
6fb5fa3c DB |
2265 | if (remove) |
2266 | { | |
456610d3 | 2267 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2268 | dump_insn_info ("removing from active", i_ptr); |
2269 | ||
dabd47e7 | 2270 | active_local_stores_len--; |
6fb5fa3c DB |
2271 | if (last) |
2272 | last->next_local_store = i_ptr->next_local_store; | |
2273 | else | |
2274 | active_local_stores = i_ptr->next_local_store; | |
2275 | } | |
2276 | else | |
2277 | last = i_ptr; | |
2278 | i_ptr = i_ptr->next_local_store; | |
2279 | } | |
2280 | } | |
b8698a0f | 2281 | else |
6fb5fa3c DB |
2282 | { |
2283 | insn_info_t i_ptr = active_local_stores; | |
2284 | insn_info_t last = NULL; | |
456610d3 | 2285 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2286 | { |
2287 | fprintf (dump_file, " processing cselib load mem:"); | |
2288 | print_inline_rtx (dump_file, mem, 0); | |
2289 | fprintf (dump_file, "\n"); | |
2290 | } | |
2291 | ||
2292 | while (i_ptr) | |
2293 | { | |
2294 | bool remove = false; | |
fd6daec9 | 2295 | store_info *store_info = i_ptr->store_rec; |
b8698a0f | 2296 | |
456610d3 | 2297 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2298 | fprintf (dump_file, " processing cselib load against insn %d\n", |
2299 | INSN_UID (i_ptr->insn)); | |
2300 | ||
2301 | /* Skip the clobbers. */ | |
2302 | while (!store_info->is_set) | |
2303 | store_info = store_info->next; | |
2304 | ||
2305 | /* If this read is just reading back something that we just | |
2306 | stored, rewrite the read. */ | |
2307 | if (store_info->rhs | |
2308 | && store_info->group_id == -1 | |
2309 | && store_info->cse_base == base | |
efc3527a | 2310 | && width != -1 |
8dd5516b JJ |
2311 | && offset >= store_info->begin |
2312 | && offset + width <= store_info->end | |
2313 | && all_positions_needed_p (store_info, | |
2314 | offset - store_info->begin, width) | |
2315 | && replace_read (store_info, i_ptr, read_info, insn_info, loc, | |
2316 | bb_info->regs_live)) | |
d7111da8 | 2317 | return; |
6fb5fa3c DB |
2318 | |
2319 | if (!store_info->alias_set) | |
b8698a0f | 2320 | remove = canon_true_dependence (store_info->mem, |
6fb5fa3c DB |
2321 | GET_MODE (store_info->mem), |
2322 | store_info->mem_addr, | |
53d9622b | 2323 | mem, mem_addr); |
b8698a0f | 2324 | |
6fb5fa3c DB |
2325 | if (remove) |
2326 | { | |
456610d3 | 2327 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2328 | dump_insn_info ("removing from active", i_ptr); |
b8698a0f | 2329 | |
dabd47e7 | 2330 | active_local_stores_len--; |
6fb5fa3c DB |
2331 | if (last) |
2332 | last->next_local_store = i_ptr->next_local_store; | |
2333 | else | |
2334 | active_local_stores = i_ptr->next_local_store; | |
2335 | } | |
2336 | else | |
2337 | last = i_ptr; | |
2338 | i_ptr = i_ptr->next_local_store; | |
2339 | } | |
2340 | } | |
6fb5fa3c DB |
2341 | } |
2342 | ||
d7111da8 | 2343 | /* A note_uses callback in which DATA points the INSN_INFO for |
6fb5fa3c DB |
2344 | as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns |
2345 | true for any part of *LOC. */ | |
2346 | ||
2347 | static void | |
2348 | check_mem_read_use (rtx *loc, void *data) | |
2349 | { | |
d7111da8 RS |
2350 | subrtx_ptr_iterator::array_type array; |
2351 | FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST) | |
2352 | { | |
2353 | rtx *loc = *iter; | |
2354 | if (MEM_P (*loc)) | |
2355 | check_mem_read_rtx (loc, (bb_info_t) data); | |
2356 | } | |
6fb5fa3c DB |
2357 | } |
2358 | ||
8dd5516b JJ |
2359 | |
2360 | /* Get arguments passed to CALL_INSN. Return TRUE if successful. | |
2361 | So far it only handles arguments passed in registers. */ | |
2362 | ||
2363 | static bool | |
2364 | get_call_args (rtx call_insn, tree fn, rtx *args, int nargs) | |
2365 | { | |
d5cc9181 JR |
2366 | CUMULATIVE_ARGS args_so_far_v; |
2367 | cumulative_args_t args_so_far; | |
8dd5516b JJ |
2368 | tree arg; |
2369 | int idx; | |
2370 | ||
d5cc9181 JR |
2371 | INIT_CUMULATIVE_ARGS (args_so_far_v, TREE_TYPE (fn), NULL_RTX, 0, 3); |
2372 | args_so_far = pack_cumulative_args (&args_so_far_v); | |
8dd5516b JJ |
2373 | |
2374 | arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2375 | for (idx = 0; | |
2376 | arg != void_list_node && idx < nargs; | |
2377 | arg = TREE_CHAIN (arg), idx++) | |
2378 | { | |
ef4bddc2 | 2379 | machine_mode mode = TYPE_MODE (TREE_VALUE (arg)); |
3c07301f | 2380 | rtx reg, link, tmp; |
d5cc9181 | 2381 | reg = targetm.calls.function_arg (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2382 | if (!reg || !REG_P (reg) || GET_MODE (reg) != mode |
2383 | || GET_MODE_CLASS (mode) != MODE_INT) | |
2384 | return false; | |
2385 | ||
2386 | for (link = CALL_INSN_FUNCTION_USAGE (call_insn); | |
2387 | link; | |
2388 | link = XEXP (link, 1)) | |
2389 | if (GET_CODE (XEXP (link, 0)) == USE) | |
2390 | { | |
2391 | args[idx] = XEXP (XEXP (link, 0), 0); | |
2392 | if (REG_P (args[idx]) | |
2393 | && REGNO (args[idx]) == REGNO (reg) | |
2394 | && (GET_MODE (args[idx]) == mode | |
2395 | || (GET_MODE_CLASS (GET_MODE (args[idx])) == MODE_INT | |
2396 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2397 | <= UNITS_PER_WORD) | |
2398 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2399 | > GET_MODE_SIZE (mode))))) | |
2400 | break; | |
2401 | } | |
2402 | if (!link) | |
2403 | return false; | |
2404 | ||
2405 | tmp = cselib_expand_value_rtx (args[idx], scratch, 5); | |
2406 | if (GET_MODE (args[idx]) != mode) | |
2407 | { | |
2408 | if (!tmp || !CONST_INT_P (tmp)) | |
2409 | return false; | |
6d26322f | 2410 | tmp = gen_int_mode (INTVAL (tmp), mode); |
8dd5516b JJ |
2411 | } |
2412 | if (tmp) | |
2413 | args[idx] = tmp; | |
2414 | ||
d5cc9181 | 2415 | targetm.calls.function_arg_advance (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2416 | } |
2417 | if (arg != void_list_node || idx != nargs) | |
2418 | return false; | |
2419 | return true; | |
2420 | } | |
2421 | ||
9e582b1d JR |
2422 | /* Return a bitmap of the fixed registers contained in IN. */ |
2423 | ||
2424 | static bitmap | |
2425 | copy_fixed_regs (const_bitmap in) | |
2426 | { | |
2427 | bitmap ret; | |
2428 | ||
2429 | ret = ALLOC_REG_SET (NULL); | |
2430 | bitmap_and (ret, in, fixed_reg_set_regset); | |
2431 | return ret; | |
2432 | } | |
8dd5516b | 2433 | |
6fb5fa3c DB |
2434 | /* Apply record_store to all candidate stores in INSN. Mark INSN |
2435 | if some part of it is not a candidate store and assigns to a | |
2436 | non-register target. */ | |
2437 | ||
2438 | static void | |
dd60a84c | 2439 | scan_insn (bb_info_t bb_info, rtx_insn *insn) |
6fb5fa3c DB |
2440 | { |
2441 | rtx body; | |
fb0b2914 | 2442 | insn_info_type *insn_info = insn_info_type_pool.allocate (); |
6fb5fa3c | 2443 | int mems_found = 0; |
da6603c6 | 2444 | memset (insn_info, 0, sizeof (struct insn_info_type)); |
6fb5fa3c | 2445 | |
456610d3 | 2446 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2447 | fprintf (dump_file, "\n**scanning insn=%d\n", |
2448 | INSN_UID (insn)); | |
2449 | ||
2450 | insn_info->prev_insn = bb_info->last_insn; | |
2451 | insn_info->insn = insn; | |
2452 | bb_info->last_insn = insn_info; | |
b8698a0f | 2453 | |
b5b8b0ac AO |
2454 | if (DEBUG_INSN_P (insn)) |
2455 | { | |
2456 | insn_info->cannot_delete = true; | |
2457 | return; | |
2458 | } | |
6fb5fa3c | 2459 | |
6fb5fa3c DB |
2460 | /* Look at all of the uses in the insn. */ |
2461 | note_uses (&PATTERN (insn), check_mem_read_use, bb_info); | |
2462 | ||
2463 | if (CALL_P (insn)) | |
2464 | { | |
8dd5516b JJ |
2465 | bool const_call; |
2466 | tree memset_call = NULL_TREE; | |
2467 | ||
6fb5fa3c | 2468 | insn_info->cannot_delete = true; |
50f0f366 | 2469 | |
6fb5fa3c | 2470 | /* Const functions cannot do anything bad i.e. read memory, |
50f0f366 | 2471 | however, they can read their parameters which may have |
8dd5516b JJ |
2472 | been pushed onto the stack. |
2473 | memset and bzero don't read memory either. */ | |
2474 | const_call = RTL_CONST_CALL_P (insn); | |
2475 | if (!const_call) | |
2476 | { | |
da4fdf2d SB |
2477 | rtx call = get_call_rtx_from (insn); |
2478 | if (call && GET_CODE (XEXP (XEXP (call, 0), 0)) == SYMBOL_REF) | |
8dd5516b JJ |
2479 | { |
2480 | rtx symbol = XEXP (XEXP (call, 0), 0); | |
2481 | if (SYMBOL_REF_DECL (symbol) | |
2482 | && TREE_CODE (SYMBOL_REF_DECL (symbol)) == FUNCTION_DECL) | |
2483 | { | |
2484 | if ((DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (symbol)) | |
2485 | == BUILT_IN_NORMAL | |
2486 | && (DECL_FUNCTION_CODE (SYMBOL_REF_DECL (symbol)) | |
2487 | == BUILT_IN_MEMSET)) | |
2488 | || SYMBOL_REF_DECL (symbol) == block_clear_fn) | |
2489 | memset_call = SYMBOL_REF_DECL (symbol); | |
2490 | } | |
2491 | } | |
2492 | } | |
2493 | if (const_call || memset_call) | |
6fb5fa3c DB |
2494 | { |
2495 | insn_info_t i_ptr = active_local_stores; | |
2496 | insn_info_t last = NULL; | |
2497 | ||
456610d3 | 2498 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2499 | fprintf (dump_file, "%s call %d\n", |
2500 | const_call ? "const" : "memset", INSN_UID (insn)); | |
6fb5fa3c | 2501 | |
64520bdc | 2502 | /* See the head comment of the frame_read field. */ |
57534689 JJ |
2503 | if (reload_completed |
2504 | /* Tail calls are storing their arguments using | |
2505 | arg pointer. If it is a frame pointer on the target, | |
2506 | even before reload we need to kill frame pointer based | |
2507 | stores. */ | |
2508 | || (SIBLING_CALL_P (insn) | |
2509 | && HARD_FRAME_POINTER_IS_ARG_POINTER)) | |
64520bdc EB |
2510 | insn_info->frame_read = true; |
2511 | ||
2512 | /* Loop over the active stores and remove those which are | |
2513 | killed by the const function call. */ | |
6fb5fa3c DB |
2514 | while (i_ptr) |
2515 | { | |
64520bdc EB |
2516 | bool remove_store = false; |
2517 | ||
2518 | /* The stack pointer based stores are always killed. */ | |
50f0f366 | 2519 | if (i_ptr->stack_pointer_based) |
64520bdc EB |
2520 | remove_store = true; |
2521 | ||
2522 | /* If the frame is read, the frame related stores are killed. */ | |
2523 | else if (insn_info->frame_read) | |
2524 | { | |
fd6daec9 | 2525 | store_info *store_info = i_ptr->store_rec; |
64520bdc EB |
2526 | |
2527 | /* Skip the clobbers. */ | |
2528 | while (!store_info->is_set) | |
2529 | store_info = store_info->next; | |
2530 | ||
2531 | if (store_info->group_id >= 0 | |
9771b263 | 2532 | && rtx_group_vec[store_info->group_id]->frame_related) |
64520bdc EB |
2533 | remove_store = true; |
2534 | } | |
2535 | ||
2536 | if (remove_store) | |
6fb5fa3c | 2537 | { |
456610d3 | 2538 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2539 | dump_insn_info ("removing from active", i_ptr); |
b8698a0f | 2540 | |
dabd47e7 | 2541 | active_local_stores_len--; |
6fb5fa3c DB |
2542 | if (last) |
2543 | last->next_local_store = i_ptr->next_local_store; | |
2544 | else | |
2545 | active_local_stores = i_ptr->next_local_store; | |
2546 | } | |
2547 | else | |
2548 | last = i_ptr; | |
64520bdc | 2549 | |
6fb5fa3c DB |
2550 | i_ptr = i_ptr->next_local_store; |
2551 | } | |
8dd5516b JJ |
2552 | |
2553 | if (memset_call) | |
2554 | { | |
2555 | rtx args[3]; | |
2556 | if (get_call_args (insn, memset_call, args, 3) | |
2557 | && CONST_INT_P (args[1]) | |
2558 | && CONST_INT_P (args[2]) | |
2559 | && INTVAL (args[2]) > 0) | |
2560 | { | |
2561 | rtx mem = gen_rtx_MEM (BLKmode, args[0]); | |
f5541398 | 2562 | set_mem_size (mem, INTVAL (args[2])); |
f7df4a84 | 2563 | body = gen_rtx_SET (mem, args[1]); |
8dd5516b | 2564 | mems_found += record_store (body, bb_info); |
456610d3 | 2565 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2566 | fprintf (dump_file, "handling memset as BLKmode store\n"); |
2567 | if (mems_found == 1) | |
2568 | { | |
dabd47e7 JJ |
2569 | if (active_local_stores_len++ |
2570 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2571 | { | |
2572 | active_local_stores_len = 1; | |
2573 | active_local_stores = NULL; | |
2574 | } | |
9e582b1d JR |
2575 | insn_info->fixed_regs_live |
2576 | = copy_fixed_regs (bb_info->regs_live); | |
8dd5516b JJ |
2577 | insn_info->next_local_store = active_local_stores; |
2578 | active_local_stores = insn_info; | |
2579 | } | |
2580 | } | |
2581 | } | |
6fb5fa3c | 2582 | } |
57534689 JJ |
2583 | else if (SIBLING_CALL_P (insn) && reload_completed) |
2584 | /* Arguments for a sibling call that are pushed to memory are passed | |
2585 | using the incoming argument pointer of the current function. After | |
2586 | reload that might be (and likely is) frame pointer based. */ | |
2587 | add_wild_read (bb_info); | |
50f0f366 | 2588 | else |
d26c7090 ER |
2589 | /* Every other call, including pure functions, may read any memory |
2590 | that is not relative to the frame. */ | |
2591 | add_non_frame_wild_read (bb_info); | |
50f0f366 | 2592 | |
6fb5fa3c DB |
2593 | return; |
2594 | } | |
2595 | ||
2596 | /* Assuming that there are sets in these insns, we cannot delete | |
2597 | them. */ | |
2598 | if ((GET_CODE (PATTERN (insn)) == CLOBBER) | |
0a64eeca | 2599 | || volatile_refs_p (PATTERN (insn)) |
2da02156 | 2600 | || (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) |
6fb5fa3c DB |
2601 | || (RTX_FRAME_RELATED_P (insn)) |
2602 | || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX)) | |
2603 | insn_info->cannot_delete = true; | |
b8698a0f | 2604 | |
6fb5fa3c DB |
2605 | body = PATTERN (insn); |
2606 | if (GET_CODE (body) == PARALLEL) | |
2607 | { | |
2608 | int i; | |
2609 | for (i = 0; i < XVECLEN (body, 0); i++) | |
2610 | mems_found += record_store (XVECEXP (body, 0, i), bb_info); | |
2611 | } | |
2612 | else | |
2613 | mems_found += record_store (body, bb_info); | |
2614 | ||
456610d3 | 2615 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 2616 | fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n", |
6fb5fa3c DB |
2617 | mems_found, insn_info->cannot_delete ? "true" : "false"); |
2618 | ||
8dd5516b JJ |
2619 | /* If we found some sets of mems, add it into the active_local_stores so |
2620 | that it can be locally deleted if found dead or used for | |
2621 | replace_read and redundant constant store elimination. Otherwise mark | |
2622 | it as cannot delete. This simplifies the processing later. */ | |
2623 | if (mems_found == 1) | |
6fb5fa3c | 2624 | { |
dabd47e7 JJ |
2625 | if (active_local_stores_len++ |
2626 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2627 | { | |
2628 | active_local_stores_len = 1; | |
2629 | active_local_stores = NULL; | |
2630 | } | |
9e582b1d | 2631 | insn_info->fixed_regs_live = copy_fixed_regs (bb_info->regs_live); |
6fb5fa3c DB |
2632 | insn_info->next_local_store = active_local_stores; |
2633 | active_local_stores = insn_info; | |
2634 | } | |
2635 | else | |
2636 | insn_info->cannot_delete = true; | |
2637 | } | |
2638 | ||
2639 | ||
2640 | /* Remove BASE from the set of active_local_stores. This is a | |
2641 | callback from cselib that is used to get rid of the stores in | |
2642 | active_local_stores. */ | |
2643 | ||
2644 | static void | |
2645 | remove_useless_values (cselib_val *base) | |
2646 | { | |
2647 | insn_info_t insn_info = active_local_stores; | |
2648 | insn_info_t last = NULL; | |
2649 | ||
2650 | while (insn_info) | |
2651 | { | |
fd6daec9 | 2652 | store_info *store_info = insn_info->store_rec; |
60564289 | 2653 | bool del = false; |
6fb5fa3c DB |
2654 | |
2655 | /* If ANY of the store_infos match the cselib group that is | |
2656 | being deleted, then the insn can not be deleted. */ | |
2657 | while (store_info) | |
2658 | { | |
b8698a0f | 2659 | if ((store_info->group_id == -1) |
6fb5fa3c DB |
2660 | && (store_info->cse_base == base)) |
2661 | { | |
60564289 | 2662 | del = true; |
6fb5fa3c DB |
2663 | break; |
2664 | } | |
2665 | store_info = store_info->next; | |
2666 | } | |
2667 | ||
60564289 | 2668 | if (del) |
6fb5fa3c | 2669 | { |
dabd47e7 | 2670 | active_local_stores_len--; |
6fb5fa3c DB |
2671 | if (last) |
2672 | last->next_local_store = insn_info->next_local_store; | |
2673 | else | |
2674 | active_local_stores = insn_info->next_local_store; | |
2675 | free_store_info (insn_info); | |
2676 | } | |
2677 | else | |
2678 | last = insn_info; | |
b8698a0f | 2679 | |
6fb5fa3c DB |
2680 | insn_info = insn_info->next_local_store; |
2681 | } | |
2682 | } | |
2683 | ||
2684 | ||
2685 | /* Do all of step 1. */ | |
2686 | ||
2687 | static void | |
2688 | dse_step1 (void) | |
2689 | { | |
2690 | basic_block bb; | |
3f9b14ff | 2691 | bitmap regs_live = BITMAP_ALLOC (®_obstack); |
b8698a0f | 2692 | |
457eeaae | 2693 | cselib_init (0); |
6fb5fa3c DB |
2694 | all_blocks = BITMAP_ALLOC (NULL); |
2695 | bitmap_set_bit (all_blocks, ENTRY_BLOCK); | |
2696 | bitmap_set_bit (all_blocks, EXIT_BLOCK); | |
2697 | ||
04a90bec | 2698 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
2699 | { |
2700 | insn_info_t ptr; | |
fb0b2914 | 2701 | bb_info_t bb_info = dse_bb_info_type_pool.allocate (); |
6fb5fa3c | 2702 | |
da6603c6 | 2703 | memset (bb_info, 0, sizeof (dse_bb_info_type)); |
6fb5fa3c | 2704 | bitmap_set_bit (all_blocks, bb->index); |
02b47899 KZ |
2705 | bb_info->regs_live = regs_live; |
2706 | ||
2707 | bitmap_copy (regs_live, DF_LR_IN (bb)); | |
2708 | df_simulate_initialize_forwards (bb, regs_live); | |
6fb5fa3c DB |
2709 | |
2710 | bb_table[bb->index] = bb_info; | |
2711 | cselib_discard_hook = remove_useless_values; | |
2712 | ||
2713 | if (bb->index >= NUM_FIXED_BLOCKS) | |
2714 | { | |
dd60a84c | 2715 | rtx_insn *insn; |
6fb5fa3c | 2716 | |
6fb5fa3c | 2717 | active_local_stores = NULL; |
dabd47e7 | 2718 | active_local_stores_len = 0; |
6fb5fa3c | 2719 | cselib_clear_table (); |
b8698a0f | 2720 | |
6fb5fa3c DB |
2721 | /* Scan the insns. */ |
2722 | FOR_BB_INSNS (bb, insn) | |
2723 | { | |
2724 | if (INSN_P (insn)) | |
2725 | scan_insn (bb_info, insn); | |
2726 | cselib_process_insn (insn); | |
02b47899 KZ |
2727 | if (INSN_P (insn)) |
2728 | df_simulate_one_insn_forwards (bb, insn, regs_live); | |
6fb5fa3c | 2729 | } |
b8698a0f | 2730 | |
6fb5fa3c DB |
2731 | /* This is something of a hack, because the global algorithm |
2732 | is supposed to take care of the case where stores go dead | |
2733 | at the end of the function. However, the global | |
2734 | algorithm must take a more conservative view of block | |
2735 | mode reads than the local alg does. So to get the case | |
2736 | where you have a store to the frame followed by a non | |
0d52bcc1 | 2737 | overlapping block more read, we look at the active local |
6fb5fa3c DB |
2738 | stores at the end of the function and delete all of the |
2739 | frame and spill based ones. */ | |
2740 | if (stores_off_frame_dead_at_return | |
2741 | && (EDGE_COUNT (bb->succs) == 0 | |
2742 | || (single_succ_p (bb) | |
fefa31b5 | 2743 | && single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (cfun) |
e3b5732b | 2744 | && ! crtl->calls_eh_return))) |
6fb5fa3c DB |
2745 | { |
2746 | insn_info_t i_ptr = active_local_stores; | |
2747 | while (i_ptr) | |
2748 | { | |
fd6daec9 | 2749 | store_info *store_info = i_ptr->store_rec; |
6fb5fa3c DB |
2750 | |
2751 | /* Skip the clobbers. */ | |
2752 | while (!store_info->is_set) | |
2753 | store_info = store_info->next; | |
8dd5516b | 2754 | if (store_info->alias_set && !i_ptr->cannot_delete) |
6fb5fa3c | 2755 | delete_dead_store_insn (i_ptr); |
b8698a0f | 2756 | else |
6fb5fa3c DB |
2757 | if (store_info->group_id >= 0) |
2758 | { | |
fd6daec9 | 2759 | group_info *group |
9771b263 | 2760 | = rtx_group_vec[store_info->group_id]; |
8dd5516b | 2761 | if (group->frame_related && !i_ptr->cannot_delete) |
6fb5fa3c DB |
2762 | delete_dead_store_insn (i_ptr); |
2763 | } | |
2764 | ||
2765 | i_ptr = i_ptr->next_local_store; | |
2766 | } | |
2767 | } | |
2768 | ||
2769 | /* Get rid of the loads that were discovered in | |
2770 | replace_read. Cselib is finished with this block. */ | |
2771 | while (deferred_change_list) | |
2772 | { | |
fd6daec9 | 2773 | deferred_change *next = deferred_change_list->next; |
6fb5fa3c DB |
2774 | |
2775 | /* There is no reason to validate this change. That was | |
2776 | done earlier. */ | |
2777 | *deferred_change_list->loc = deferred_change_list->reg; | |
fb0b2914 | 2778 | deferred_change_pool.remove (deferred_change_list); |
6fb5fa3c DB |
2779 | deferred_change_list = next; |
2780 | } | |
2781 | ||
2782 | /* Get rid of all of the cselib based store_infos in this | |
2783 | block and mark the containing insns as not being | |
2784 | deletable. */ | |
2785 | ptr = bb_info->last_insn; | |
2786 | while (ptr) | |
2787 | { | |
2788 | if (ptr->contains_cselib_groups) | |
8dd5516b | 2789 | { |
fd6daec9 | 2790 | store_info *s_info = ptr->store_rec; |
8dd5516b JJ |
2791 | while (s_info && !s_info->is_set) |
2792 | s_info = s_info->next; | |
2793 | if (s_info | |
2794 | && s_info->redundant_reason | |
2795 | && s_info->redundant_reason->insn | |
2796 | && !ptr->cannot_delete) | |
2797 | { | |
456610d3 | 2798 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2799 | fprintf (dump_file, "Locally deleting insn %d " |
2800 | "because insn %d stores the " | |
2801 | "same value and couldn't be " | |
2802 | "eliminated\n", | |
2803 | INSN_UID (ptr->insn), | |
2804 | INSN_UID (s_info->redundant_reason->insn)); | |
2805 | delete_dead_store_insn (ptr); | |
2806 | } | |
8dd5516b JJ |
2807 | free_store_info (ptr); |
2808 | } | |
2809 | else | |
2810 | { | |
fd6daec9 | 2811 | store_info *s_info; |
8dd5516b JJ |
2812 | |
2813 | /* Free at least positions_needed bitmaps. */ | |
2814 | for (s_info = ptr->store_rec; s_info; s_info = s_info->next) | |
2815 | if (s_info->is_large) | |
2816 | { | |
dc491a25 | 2817 | BITMAP_FREE (s_info->positions_needed.large.bmap); |
8dd5516b JJ |
2818 | s_info->is_large = false; |
2819 | } | |
2820 | } | |
6fb5fa3c DB |
2821 | ptr = ptr->prev_insn; |
2822 | } | |
2823 | ||
da6603c6 | 2824 | cse_store_info_pool.release (); |
6fb5fa3c | 2825 | } |
02b47899 | 2826 | bb_info->regs_live = NULL; |
6fb5fa3c DB |
2827 | } |
2828 | ||
02b47899 | 2829 | BITMAP_FREE (regs_live); |
6fb5fa3c | 2830 | cselib_finish (); |
c203e8a7 | 2831 | rtx_group_table->empty (); |
6fb5fa3c DB |
2832 | } |
2833 | ||
2834 | \f | |
2835 | /*---------------------------------------------------------------------------- | |
2836 | Second step. | |
2837 | ||
2838 | Assign each byte position in the stores that we are going to | |
2839 | analyze globally to a position in the bitmaps. Returns true if | |
6ed3da00 | 2840 | there are any bit positions assigned. |
6fb5fa3c DB |
2841 | ----------------------------------------------------------------------------*/ |
2842 | ||
2843 | static void | |
2844 | dse_step2_init (void) | |
2845 | { | |
2846 | unsigned int i; | |
fd6daec9 | 2847 | group_info *group; |
6fb5fa3c | 2848 | |
9771b263 | 2849 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2850 | { |
2851 | /* For all non stack related bases, we only consider a store to | |
2852 | be deletable if there are two or more stores for that | |
2853 | position. This is because it takes one store to make the | |
2854 | other store redundant. However, for the stores that are | |
2855 | stack related, we consider them if there is only one store | |
2856 | for the position. We do this because the stack related | |
2857 | stores can be deleted if their is no read between them and | |
2858 | the end of the function. | |
b8698a0f | 2859 | |
6fb5fa3c DB |
2860 | To make this work in the current framework, we take the stack |
2861 | related bases add all of the bits from store1 into store2. | |
2862 | This has the effect of making the eligible even if there is | |
2863 | only one store. */ | |
2864 | ||
2865 | if (stores_off_frame_dead_at_return && group->frame_related) | |
2866 | { | |
2867 | bitmap_ior_into (group->store2_n, group->store1_n); | |
2868 | bitmap_ior_into (group->store2_p, group->store1_p); | |
456610d3 | 2869 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 2870 | fprintf (dump_file, "group %d is frame related ", i); |
6fb5fa3c DB |
2871 | } |
2872 | ||
2873 | group->offset_map_size_n++; | |
3f9b14ff SB |
2874 | group->offset_map_n = XOBNEWVEC (&dse_obstack, int, |
2875 | group->offset_map_size_n); | |
6fb5fa3c | 2876 | group->offset_map_size_p++; |
3f9b14ff SB |
2877 | group->offset_map_p = XOBNEWVEC (&dse_obstack, int, |
2878 | group->offset_map_size_p); | |
6fb5fa3c | 2879 | group->process_globally = false; |
456610d3 | 2880 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2881 | { |
b8698a0f | 2882 | fprintf (dump_file, "group %d(%d+%d): ", i, |
6fb5fa3c DB |
2883 | (int)bitmap_count_bits (group->store2_n), |
2884 | (int)bitmap_count_bits (group->store2_p)); | |
2885 | bitmap_print (dump_file, group->store2_n, "n ", " "); | |
2886 | bitmap_print (dump_file, group->store2_p, "p ", "\n"); | |
2887 | } | |
2888 | } | |
2889 | } | |
2890 | ||
2891 | ||
2892 | /* Init the offset tables for the normal case. */ | |
2893 | ||
2894 | static bool | |
2895 | dse_step2_nospill (void) | |
2896 | { | |
2897 | unsigned int i; | |
fd6daec9 | 2898 | group_info *group; |
6fb5fa3c DB |
2899 | /* Position 0 is unused because 0 is used in the maps to mean |
2900 | unused. */ | |
2901 | current_position = 1; | |
9771b263 | 2902 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2903 | { |
2904 | bitmap_iterator bi; | |
2905 | unsigned int j; | |
2906 | ||
2907 | if (group == clear_alias_group) | |
2908 | continue; | |
2909 | ||
c3284718 RS |
2910 | memset (group->offset_map_n, 0, sizeof (int) * group->offset_map_size_n); |
2911 | memset (group->offset_map_p, 0, sizeof (int) * group->offset_map_size_p); | |
6fb5fa3c DB |
2912 | bitmap_clear (group->group_kill); |
2913 | ||
2914 | EXECUTE_IF_SET_IN_BITMAP (group->store2_n, 0, j, bi) | |
2915 | { | |
2916 | bitmap_set_bit (group->group_kill, current_position); | |
d26c7090 ER |
2917 | if (bitmap_bit_p (group->escaped_n, j)) |
2918 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2919 | group->offset_map_n[j] = current_position++; |
2920 | group->process_globally = true; | |
2921 | } | |
2922 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2923 | { | |
b8698a0f | 2924 | bitmap_set_bit (group->group_kill, current_position); |
d26c7090 ER |
2925 | if (bitmap_bit_p (group->escaped_p, j)) |
2926 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2927 | group->offset_map_p[j] = current_position++; |
2928 | group->process_globally = true; | |
2929 | } | |
2930 | } | |
2931 | return current_position != 1; | |
2932 | } | |
2933 | ||
2934 | ||
6fb5fa3c DB |
2935 | \f |
2936 | /*---------------------------------------------------------------------------- | |
2937 | Third step. | |
b8698a0f | 2938 | |
6fb5fa3c DB |
2939 | Build the bit vectors for the transfer functions. |
2940 | ----------------------------------------------------------------------------*/ | |
2941 | ||
2942 | ||
6fb5fa3c DB |
2943 | /* Look up the bitmap index for OFFSET in GROUP_INFO. If it is not |
2944 | there, return 0. */ | |
2945 | ||
2946 | static int | |
fd6daec9 | 2947 | get_bitmap_index (group_info *group_info, HOST_WIDE_INT offset) |
6fb5fa3c DB |
2948 | { |
2949 | if (offset < 0) | |
2950 | { | |
2951 | HOST_WIDE_INT offset_p = -offset; | |
2952 | if (offset_p >= group_info->offset_map_size_n) | |
2953 | return 0; | |
2954 | return group_info->offset_map_n[offset_p]; | |
2955 | } | |
2956 | else | |
2957 | { | |
2958 | if (offset >= group_info->offset_map_size_p) | |
2959 | return 0; | |
2960 | return group_info->offset_map_p[offset]; | |
2961 | } | |
2962 | } | |
2963 | ||
2964 | ||
2965 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
2966 | may be NULL. */ | |
2967 | ||
b8698a0f | 2968 | static void |
fd6daec9 | 2969 | scan_stores_nospill (store_info *store_info, bitmap gen, bitmap kill) |
6fb5fa3c DB |
2970 | { |
2971 | while (store_info) | |
2972 | { | |
2973 | HOST_WIDE_INT i; | |
fd6daec9 | 2974 | group_info *group_info |
9771b263 | 2975 | = rtx_group_vec[store_info->group_id]; |
6fb5fa3c DB |
2976 | if (group_info->process_globally) |
2977 | for (i = store_info->begin; i < store_info->end; i++) | |
2978 | { | |
2979 | int index = get_bitmap_index (group_info, i); | |
2980 | if (index != 0) | |
2981 | { | |
2982 | bitmap_set_bit (gen, index); | |
2983 | if (kill) | |
2984 | bitmap_clear_bit (kill, index); | |
2985 | } | |
2986 | } | |
2987 | store_info = store_info->next; | |
2988 | } | |
2989 | } | |
2990 | ||
2991 | ||
2992 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
2993 | may be NULL. */ | |
2994 | ||
b8698a0f | 2995 | static void |
fd6daec9 | 2996 | scan_stores_spill (store_info *store_info, bitmap gen, bitmap kill) |
6fb5fa3c DB |
2997 | { |
2998 | while (store_info) | |
2999 | { | |
3000 | if (store_info->alias_set) | |
3001 | { | |
b8698a0f | 3002 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3003 | store_info->alias_set); |
3004 | if (index != 0) | |
3005 | { | |
3006 | bitmap_set_bit (gen, index); | |
3007 | if (kill) | |
3008 | bitmap_clear_bit (kill, index); | |
3009 | } | |
3010 | } | |
3011 | store_info = store_info->next; | |
3012 | } | |
3013 | } | |
3014 | ||
3015 | ||
3016 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3017 | may be NULL. */ | |
3018 | ||
3019 | static void | |
3020 | scan_reads_nospill (insn_info_t insn_info, bitmap gen, bitmap kill) | |
3021 | { | |
3022 | read_info_t read_info = insn_info->read_rec; | |
3023 | int i; | |
fd6daec9 | 3024 | group_info *group; |
6fb5fa3c | 3025 | |
64520bdc EB |
3026 | /* If this insn reads the frame, kill all the frame related stores. */ |
3027 | if (insn_info->frame_read) | |
3028 | { | |
9771b263 | 3029 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
64520bdc EB |
3030 | if (group->process_globally && group->frame_related) |
3031 | { | |
3032 | if (kill) | |
3033 | bitmap_ior_into (kill, group->group_kill); | |
b8698a0f | 3034 | bitmap_and_compl_into (gen, group->group_kill); |
64520bdc EB |
3035 | } |
3036 | } | |
d26c7090 ER |
3037 | if (insn_info->non_frame_wild_read) |
3038 | { | |
3039 | /* Kill all non-frame related stores. Kill all stores of variables that | |
3040 | escape. */ | |
3041 | if (kill) | |
3042 | bitmap_ior_into (kill, kill_on_calls); | |
3043 | bitmap_and_compl_into (gen, kill_on_calls); | |
9771b263 | 3044 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
d26c7090 ER |
3045 | if (group->process_globally && !group->frame_related) |
3046 | { | |
3047 | if (kill) | |
3048 | bitmap_ior_into (kill, group->group_kill); | |
3049 | bitmap_and_compl_into (gen, group->group_kill); | |
3050 | } | |
3051 | } | |
6fb5fa3c DB |
3052 | while (read_info) |
3053 | { | |
9771b263 | 3054 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
3055 | { |
3056 | if (group->process_globally) | |
3057 | { | |
3058 | if (i == read_info->group_id) | |
3059 | { | |
3060 | if (read_info->begin > read_info->end) | |
3061 | { | |
3062 | /* Begin > end for block mode reads. */ | |
3063 | if (kill) | |
3064 | bitmap_ior_into (kill, group->group_kill); | |
3065 | bitmap_and_compl_into (gen, group->group_kill); | |
3066 | } | |
3067 | else | |
3068 | { | |
3069 | /* The groups are the same, just process the | |
3070 | offsets. */ | |
3071 | HOST_WIDE_INT j; | |
3072 | for (j = read_info->begin; j < read_info->end; j++) | |
3073 | { | |
3074 | int index = get_bitmap_index (group, j); | |
3075 | if (index != 0) | |
3076 | { | |
3077 | if (kill) | |
3078 | bitmap_set_bit (kill, index); | |
3079 | bitmap_clear_bit (gen, index); | |
3080 | } | |
3081 | } | |
3082 | } | |
3083 | } | |
3084 | else | |
3085 | { | |
3086 | /* The groups are different, if the alias sets | |
3087 | conflict, clear the entire group. We only need | |
3088 | to apply this test if the read_info is a cselib | |
3089 | read. Anything with a constant base cannot alias | |
3090 | something else with a different constant | |
3091 | base. */ | |
3092 | if ((read_info->group_id < 0) | |
b8698a0f | 3093 | && canon_true_dependence (group->base_mem, |
d32f725a | 3094 | GET_MODE (group->base_mem), |
6216f94e | 3095 | group->canon_base_addr, |
53d9622b | 3096 | read_info->mem, NULL_RTX)) |
6fb5fa3c DB |
3097 | { |
3098 | if (kill) | |
3099 | bitmap_ior_into (kill, group->group_kill); | |
3100 | bitmap_and_compl_into (gen, group->group_kill); | |
3101 | } | |
3102 | } | |
3103 | } | |
3104 | } | |
b8698a0f | 3105 | |
6fb5fa3c DB |
3106 | read_info = read_info->next; |
3107 | } | |
3108 | } | |
3109 | ||
3110 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL | |
3111 | may be NULL. */ | |
3112 | ||
3113 | static void | |
3114 | scan_reads_spill (read_info_t read_info, bitmap gen, bitmap kill) | |
3115 | { | |
3116 | while (read_info) | |
3117 | { | |
3118 | if (read_info->alias_set) | |
3119 | { | |
b8698a0f | 3120 | int index = get_bitmap_index (clear_alias_group, |
6fb5fa3c DB |
3121 | read_info->alias_set); |
3122 | if (index != 0) | |
3123 | { | |
3124 | if (kill) | |
3125 | bitmap_set_bit (kill, index); | |
3126 | bitmap_clear_bit (gen, index); | |
3127 | } | |
3128 | } | |
b8698a0f | 3129 | |
6fb5fa3c DB |
3130 | read_info = read_info->next; |
3131 | } | |
3132 | } | |
3133 | ||
3134 | ||
3135 | /* Return the insn in BB_INFO before the first wild read or if there | |
3136 | are no wild reads in the block, return the last insn. */ | |
3137 | ||
3138 | static insn_info_t | |
3139 | find_insn_before_first_wild_read (bb_info_t bb_info) | |
3140 | { | |
3141 | insn_info_t insn_info = bb_info->last_insn; | |
3142 | insn_info_t last_wild_read = NULL; | |
3143 | ||
3144 | while (insn_info) | |
3145 | { | |
3146 | if (insn_info->wild_read) | |
3147 | { | |
3148 | last_wild_read = insn_info->prev_insn; | |
3149 | /* Block starts with wild read. */ | |
3150 | if (!last_wild_read) | |
3151 | return NULL; | |
3152 | } | |
3153 | ||
3154 | insn_info = insn_info->prev_insn; | |
3155 | } | |
3156 | ||
3157 | if (last_wild_read) | |
3158 | return last_wild_read; | |
3159 | else | |
3160 | return bb_info->last_insn; | |
3161 | } | |
3162 | ||
3163 | ||
3164 | /* Scan the insns in BB_INFO starting at PTR and going to the top of | |
3165 | the block in order to build the gen and kill sets for the block. | |
3166 | We start at ptr which may be the last insn in the block or may be | |
3167 | the first insn with a wild read. In the latter case we are able to | |
3168 | skip the rest of the block because it just does not matter: | |
3169 | anything that happens is hidden by the wild read. */ | |
3170 | ||
3171 | static void | |
3172 | dse_step3_scan (bool for_spills, basic_block bb) | |
3173 | { | |
3174 | bb_info_t bb_info = bb_table[bb->index]; | |
3175 | insn_info_t insn_info; | |
3176 | ||
3177 | if (for_spills) | |
3178 | /* There are no wild reads in the spill case. */ | |
3179 | insn_info = bb_info->last_insn; | |
3180 | else | |
3181 | insn_info = find_insn_before_first_wild_read (bb_info); | |
b8698a0f | 3182 | |
6fb5fa3c DB |
3183 | /* In the spill case or in the no_spill case if there is no wild |
3184 | read in the block, we will need a kill set. */ | |
3185 | if (insn_info == bb_info->last_insn) | |
3186 | { | |
3187 | if (bb_info->kill) | |
3188 | bitmap_clear (bb_info->kill); | |
3189 | else | |
3f9b14ff | 3190 | bb_info->kill = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c | 3191 | } |
b8698a0f | 3192 | else |
6fb5fa3c DB |
3193 | if (bb_info->kill) |
3194 | BITMAP_FREE (bb_info->kill); | |
3195 | ||
3196 | while (insn_info) | |
3197 | { | |
3198 | /* There may have been code deleted by the dce pass run before | |
3199 | this phase. */ | |
3200 | if (insn_info->insn && INSN_P (insn_info->insn)) | |
3201 | { | |
b8698a0f | 3202 | /* Process the read(s) last. */ |
6fb5fa3c DB |
3203 | if (for_spills) |
3204 | { | |
3205 | scan_stores_spill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3206 | scan_reads_spill (insn_info->read_rec, bb_info->gen, bb_info->kill); | |
3207 | } | |
3208 | else | |
3209 | { | |
3210 | scan_stores_nospill (insn_info->store_rec, bb_info->gen, bb_info->kill); | |
3211 | scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill); | |
3212 | } | |
b8698a0f | 3213 | } |
6fb5fa3c DB |
3214 | |
3215 | insn_info = insn_info->prev_insn; | |
3216 | } | |
3217 | } | |
3218 | ||
3219 | ||
3220 | /* Set the gen set of the exit block, and also any block with no | |
3221 | successors that does not have a wild read. */ | |
3222 | ||
3223 | static void | |
3224 | dse_step3_exit_block_scan (bb_info_t bb_info) | |
3225 | { | |
3226 | /* The gen set is all 0's for the exit block except for the | |
3227 | frame_pointer_group. */ | |
b8698a0f | 3228 | |
6fb5fa3c DB |
3229 | if (stores_off_frame_dead_at_return) |
3230 | { | |
3231 | unsigned int i; | |
fd6daec9 | 3232 | group_info *group; |
b8698a0f | 3233 | |
9771b263 | 3234 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
3235 | { |
3236 | if (group->process_globally && group->frame_related) | |
3237 | bitmap_ior_into (bb_info->gen, group->group_kill); | |
3238 | } | |
3239 | } | |
3240 | } | |
3241 | ||
3242 | ||
3243 | /* Find all of the blocks that are not backwards reachable from the | |
3244 | exit block or any block with no successors (BB). These are the | |
3245 | infinite loops or infinite self loops. These blocks will still | |
3246 | have their bits set in UNREACHABLE_BLOCKS. */ | |
3247 | ||
3248 | static void | |
3249 | mark_reachable_blocks (sbitmap unreachable_blocks, basic_block bb) | |
3250 | { | |
3251 | edge e; | |
3252 | edge_iterator ei; | |
3253 | ||
d7c028c0 | 3254 | if (bitmap_bit_p (unreachable_blocks, bb->index)) |
6fb5fa3c | 3255 | { |
d7c028c0 | 3256 | bitmap_clear_bit (unreachable_blocks, bb->index); |
6fb5fa3c | 3257 | FOR_EACH_EDGE (e, ei, bb->preds) |
b8698a0f | 3258 | { |
6fb5fa3c | 3259 | mark_reachable_blocks (unreachable_blocks, e->src); |
b8698a0f | 3260 | } |
6fb5fa3c DB |
3261 | } |
3262 | } | |
3263 | ||
3264 | /* Build the transfer functions for the function. */ | |
3265 | ||
3266 | static void | |
3267 | dse_step3 (bool for_spills) | |
3268 | { | |
3269 | basic_block bb; | |
8b1c6fd7 | 3270 | sbitmap unreachable_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
6fb5fa3c DB |
3271 | sbitmap_iterator sbi; |
3272 | bitmap all_ones = NULL; | |
3273 | unsigned int i; | |
b8698a0f | 3274 | |
f61e445a | 3275 | bitmap_ones (unreachable_blocks); |
6fb5fa3c | 3276 | |
04a90bec | 3277 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
3278 | { |
3279 | bb_info_t bb_info = bb_table[bb->index]; | |
3280 | if (bb_info->gen) | |
3281 | bitmap_clear (bb_info->gen); | |
3282 | else | |
3f9b14ff | 3283 | bb_info->gen = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3284 | |
3285 | if (bb->index == ENTRY_BLOCK) | |
3286 | ; | |
3287 | else if (bb->index == EXIT_BLOCK) | |
3288 | dse_step3_exit_block_scan (bb_info); | |
3289 | else | |
3290 | dse_step3_scan (for_spills, bb); | |
3291 | if (EDGE_COUNT (bb->succs) == 0) | |
3292 | mark_reachable_blocks (unreachable_blocks, bb); | |
3293 | ||
3294 | /* If this is the second time dataflow is run, delete the old | |
3295 | sets. */ | |
3296 | if (bb_info->in) | |
3297 | BITMAP_FREE (bb_info->in); | |
3298 | if (bb_info->out) | |
3299 | BITMAP_FREE (bb_info->out); | |
3300 | } | |
3301 | ||
3302 | /* For any block in an infinite loop, we must initialize the out set | |
3303 | to all ones. This could be expensive, but almost never occurs in | |
3304 | practice. However, it is common in regression tests. */ | |
d4ac4ce2 | 3305 | EXECUTE_IF_SET_IN_BITMAP (unreachable_blocks, 0, i, sbi) |
6fb5fa3c DB |
3306 | { |
3307 | if (bitmap_bit_p (all_blocks, i)) | |
3308 | { | |
3309 | bb_info_t bb_info = bb_table[i]; | |
3310 | if (!all_ones) | |
3311 | { | |
3312 | unsigned int j; | |
fd6daec9 | 3313 | group_info *group; |
6fb5fa3c | 3314 | |
3f9b14ff | 3315 | all_ones = BITMAP_ALLOC (&dse_bitmap_obstack); |
9771b263 | 3316 | FOR_EACH_VEC_ELT (rtx_group_vec, j, group) |
6fb5fa3c DB |
3317 | bitmap_ior_into (all_ones, group->group_kill); |
3318 | } | |
3319 | if (!bb_info->out) | |
3320 | { | |
3f9b14ff | 3321 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3322 | bitmap_copy (bb_info->out, all_ones); |
3323 | } | |
3324 | } | |
3325 | } | |
3326 | ||
3327 | if (all_ones) | |
3328 | BITMAP_FREE (all_ones); | |
3329 | sbitmap_free (unreachable_blocks); | |
3330 | } | |
3331 | ||
3332 | ||
3333 | \f | |
3334 | /*---------------------------------------------------------------------------- | |
3335 | Fourth step. | |
3336 | ||
3337 | Solve the bitvector equations. | |
3338 | ----------------------------------------------------------------------------*/ | |
3339 | ||
3340 | ||
3341 | /* Confluence function for blocks with no successors. Create an out | |
3342 | set from the gen set of the exit block. This block logically has | |
3343 | the exit block as a successor. */ | |
3344 | ||
3345 | ||
3346 | ||
3347 | static void | |
3348 | dse_confluence_0 (basic_block bb) | |
3349 | { | |
3350 | bb_info_t bb_info = bb_table[bb->index]; | |
3351 | ||
3352 | if (bb->index == EXIT_BLOCK) | |
3353 | return; | |
3354 | ||
3355 | if (!bb_info->out) | |
3356 | { | |
3f9b14ff | 3357 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3358 | bitmap_copy (bb_info->out, bb_table[EXIT_BLOCK]->gen); |
3359 | } | |
3360 | } | |
3361 | ||
3362 | /* Propagate the information from the in set of the dest of E to the | |
3363 | out set of the src of E. If the various in or out sets are not | |
3364 | there, that means they are all ones. */ | |
3365 | ||
1a0f3fa1 | 3366 | static bool |
6fb5fa3c DB |
3367 | dse_confluence_n (edge e) |
3368 | { | |
3369 | bb_info_t src_info = bb_table[e->src->index]; | |
3370 | bb_info_t dest_info = bb_table[e->dest->index]; | |
3371 | ||
3372 | if (dest_info->in) | |
3373 | { | |
3374 | if (src_info->out) | |
3375 | bitmap_and_into (src_info->out, dest_info->in); | |
3376 | else | |
3377 | { | |
3f9b14ff | 3378 | src_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3379 | bitmap_copy (src_info->out, dest_info->in); |
3380 | } | |
3381 | } | |
1a0f3fa1 | 3382 | return true; |
6fb5fa3c DB |
3383 | } |
3384 | ||
3385 | ||
3386 | /* Propagate the info from the out to the in set of BB_INDEX's basic | |
b8698a0f | 3387 | block. There are three cases: |
6fb5fa3c DB |
3388 | |
3389 | 1) The block has no kill set. In this case the kill set is all | |
3390 | ones. It does not matter what the out set of the block is, none of | |
3391 | the info can reach the top. The only thing that reaches the top is | |
3392 | the gen set and we just copy the set. | |
3393 | ||
3394 | 2) There is a kill set but no out set and bb has successors. In | |
3395 | this case we just return. Eventually an out set will be created and | |
3396 | it is better to wait than to create a set of ones. | |
3397 | ||
3398 | 3) There is both a kill and out set. We apply the obvious transfer | |
3399 | function. | |
3400 | */ | |
3401 | ||
3402 | static bool | |
3403 | dse_transfer_function (int bb_index) | |
3404 | { | |
3405 | bb_info_t bb_info = bb_table[bb_index]; | |
3406 | ||
3407 | if (bb_info->kill) | |
3408 | { | |
3409 | if (bb_info->out) | |
3410 | { | |
3411 | /* Case 3 above. */ | |
3412 | if (bb_info->in) | |
b8698a0f | 3413 | return bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3414 | bb_info->out, bb_info->kill); |
3415 | else | |
3416 | { | |
3f9b14ff | 3417 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
b8698a0f | 3418 | bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3419 | bb_info->out, bb_info->kill); |
3420 | return true; | |
3421 | } | |
3422 | } | |
3423 | else | |
3424 | /* Case 2 above. */ | |
3425 | return false; | |
3426 | } | |
3427 | else | |
3428 | { | |
3429 | /* Case 1 above. If there is already an in set, nothing | |
3430 | happens. */ | |
3431 | if (bb_info->in) | |
3432 | return false; | |
3433 | else | |
3434 | { | |
3f9b14ff | 3435 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3436 | bitmap_copy (bb_info->in, bb_info->gen); |
3437 | return true; | |
3438 | } | |
3439 | } | |
3440 | } | |
3441 | ||
3442 | /* Solve the dataflow equations. */ | |
3443 | ||
3444 | static void | |
3445 | dse_step4 (void) | |
3446 | { | |
b8698a0f L |
3447 | df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0, |
3448 | dse_confluence_n, dse_transfer_function, | |
3449 | all_blocks, df_get_postorder (DF_BACKWARD), | |
6fb5fa3c | 3450 | df_get_n_blocks (DF_BACKWARD)); |
456610d3 | 3451 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3452 | { |
3453 | basic_block bb; | |
3454 | ||
3455 | fprintf (dump_file, "\n\n*** Global dataflow info after analysis.\n"); | |
04a90bec | 3456 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
3457 | { |
3458 | bb_info_t bb_info = bb_table[bb->index]; | |
3459 | ||
3460 | df_print_bb_index (bb, dump_file); | |
3461 | if (bb_info->in) | |
3462 | bitmap_print (dump_file, bb_info->in, " in: ", "\n"); | |
3463 | else | |
3464 | fprintf (dump_file, " in: *MISSING*\n"); | |
3465 | if (bb_info->gen) | |
3466 | bitmap_print (dump_file, bb_info->gen, " gen: ", "\n"); | |
3467 | else | |
3468 | fprintf (dump_file, " gen: *MISSING*\n"); | |
3469 | if (bb_info->kill) | |
3470 | bitmap_print (dump_file, bb_info->kill, " kill: ", "\n"); | |
3471 | else | |
3472 | fprintf (dump_file, " kill: *MISSING*\n"); | |
3473 | if (bb_info->out) | |
3474 | bitmap_print (dump_file, bb_info->out, " out: ", "\n"); | |
3475 | else | |
3476 | fprintf (dump_file, " out: *MISSING*\n\n"); | |
3477 | } | |
3478 | } | |
3479 | } | |
3480 | ||
3481 | ||
3482 | \f | |
3483 | /*---------------------------------------------------------------------------- | |
3484 | Fifth step. | |
3485 | ||
0d52bcc1 | 3486 | Delete the stores that can only be deleted using the global information. |
6fb5fa3c DB |
3487 | ----------------------------------------------------------------------------*/ |
3488 | ||
3489 | ||
3490 | static void | |
3491 | dse_step5_nospill (void) | |
3492 | { | |
3493 | basic_block bb; | |
11cd3bed | 3494 | FOR_EACH_BB_FN (bb, cfun) |
6fb5fa3c DB |
3495 | { |
3496 | bb_info_t bb_info = bb_table[bb->index]; | |
3497 | insn_info_t insn_info = bb_info->last_insn; | |
3498 | bitmap v = bb_info->out; | |
3499 | ||
3500 | while (insn_info) | |
3501 | { | |
3502 | bool deleted = false; | |
3503 | if (dump_file && insn_info->insn) | |
3504 | { | |
3505 | fprintf (dump_file, "starting to process insn %d\n", | |
3506 | INSN_UID (insn_info->insn)); | |
3507 | bitmap_print (dump_file, v, " v: ", "\n"); | |
3508 | } | |
3509 | ||
3510 | /* There may have been code deleted by the dce pass run before | |
3511 | this phase. */ | |
b8698a0f | 3512 | if (insn_info->insn |
6fb5fa3c DB |
3513 | && INSN_P (insn_info->insn) |
3514 | && (!insn_info->cannot_delete) | |
3515 | && (!bitmap_empty_p (v))) | |
3516 | { | |
fd6daec9 | 3517 | store_info *store_info = insn_info->store_rec; |
6fb5fa3c DB |
3518 | |
3519 | /* Try to delete the current insn. */ | |
3520 | deleted = true; | |
b8698a0f | 3521 | |
6fb5fa3c DB |
3522 | /* Skip the clobbers. */ |
3523 | while (!store_info->is_set) | |
3524 | store_info = store_info->next; | |
3525 | ||
3526 | if (store_info->alias_set) | |
3527 | deleted = false; | |
3528 | else | |
3529 | { | |
3530 | HOST_WIDE_INT i; | |
fd6daec9 | 3531 | group_info *group_info |
9771b263 | 3532 | = rtx_group_vec[store_info->group_id]; |
b8698a0f | 3533 | |
6fb5fa3c DB |
3534 | for (i = store_info->begin; i < store_info->end; i++) |
3535 | { | |
3536 | int index = get_bitmap_index (group_info, i); | |
b8698a0f | 3537 | |
456610d3 | 3538 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 3539 | fprintf (dump_file, "i = %d, index = %d\n", (int)i, index); |
6fb5fa3c DB |
3540 | if (index == 0 || !bitmap_bit_p (v, index)) |
3541 | { | |
456610d3 | 3542 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 3543 | fprintf (dump_file, "failing at i = %d\n", (int)i); |
6fb5fa3c DB |
3544 | deleted = false; |
3545 | break; | |
3546 | } | |
3547 | } | |
3548 | } | |
3549 | if (deleted) | |
3550 | { | |
9e582b1d JR |
3551 | if (dbg_cnt (dse) |
3552 | && check_for_inc_dec_1 (insn_info)) | |
6fb5fa3c | 3553 | { |
6fb5fa3c DB |
3554 | delete_insn (insn_info->insn); |
3555 | insn_info->insn = NULL; | |
3556 | globally_deleted++; | |
3557 | } | |
3558 | } | |
3559 | } | |
3560 | /* We do want to process the local info if the insn was | |
6ed3da00 | 3561 | deleted. For instance, if the insn did a wild read, we |
6fb5fa3c | 3562 | no longer need to trash the info. */ |
b8698a0f | 3563 | if (insn_info->insn |
6fb5fa3c DB |
3564 | && INSN_P (insn_info->insn) |
3565 | && (!deleted)) | |
3566 | { | |
3567 | scan_stores_nospill (insn_info->store_rec, v, NULL); | |
3568 | if (insn_info->wild_read) | |
3569 | { | |
456610d3 | 3570 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3571 | fprintf (dump_file, "wild read\n"); |
3572 | bitmap_clear (v); | |
3573 | } | |
d26c7090 ER |
3574 | else if (insn_info->read_rec |
3575 | || insn_info->non_frame_wild_read) | |
6fb5fa3c | 3576 | { |
d26c7090 | 3577 | if (dump_file && !insn_info->non_frame_wild_read) |
6fb5fa3c | 3578 | fprintf (dump_file, "regular read\n"); |
456610d3 | 3579 | else if (dump_file && (dump_flags & TDF_DETAILS)) |
d26c7090 | 3580 | fprintf (dump_file, "non-frame wild read\n"); |
6fb5fa3c DB |
3581 | scan_reads_nospill (insn_info, v, NULL); |
3582 | } | |
3583 | } | |
b8698a0f | 3584 | |
6fb5fa3c DB |
3585 | insn_info = insn_info->prev_insn; |
3586 | } | |
3587 | } | |
3588 | } | |
3589 | ||
3590 | ||
6fb5fa3c DB |
3591 | \f |
3592 | /*---------------------------------------------------------------------------- | |
3593 | Sixth step. | |
3594 | ||
8dd5516b JJ |
3595 | Delete stores made redundant by earlier stores (which store the same |
3596 | value) that couldn't be eliminated. | |
3597 | ----------------------------------------------------------------------------*/ | |
3598 | ||
3599 | static void | |
3600 | dse_step6 (void) | |
3601 | { | |
3602 | basic_block bb; | |
3603 | ||
04a90bec | 3604 | FOR_ALL_BB_FN (bb, cfun) |
8dd5516b JJ |
3605 | { |
3606 | bb_info_t bb_info = bb_table[bb->index]; | |
3607 | insn_info_t insn_info = bb_info->last_insn; | |
3608 | ||
3609 | while (insn_info) | |
3610 | { | |
3611 | /* There may have been code deleted by the dce pass run before | |
3612 | this phase. */ | |
3613 | if (insn_info->insn | |
3614 | && INSN_P (insn_info->insn) | |
3615 | && !insn_info->cannot_delete) | |
3616 | { | |
fd6daec9 | 3617 | store_info *s_info = insn_info->store_rec; |
8dd5516b JJ |
3618 | |
3619 | while (s_info && !s_info->is_set) | |
3620 | s_info = s_info->next; | |
3621 | if (s_info | |
3622 | && s_info->redundant_reason | |
3623 | && s_info->redundant_reason->insn | |
3624 | && INSN_P (s_info->redundant_reason->insn)) | |
3625 | { | |
eb92d49a | 3626 | rtx_insn *rinsn = s_info->redundant_reason->insn; |
456610d3 | 3627 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
3628 | fprintf (dump_file, "Locally deleting insn %d " |
3629 | "because insn %d stores the " | |
3630 | "same value and couldn't be " | |
3631 | "eliminated\n", | |
3632 | INSN_UID (insn_info->insn), | |
3633 | INSN_UID (rinsn)); | |
3634 | delete_dead_store_insn (insn_info); | |
3635 | } | |
3636 | } | |
3637 | insn_info = insn_info->prev_insn; | |
3638 | } | |
3639 | } | |
3640 | } | |
3641 | \f | |
3642 | /*---------------------------------------------------------------------------- | |
3643 | Seventh step. | |
3644 | ||
b8698a0f | 3645 | Destroy everything left standing. |
6fb5fa3c DB |
3646 | ----------------------------------------------------------------------------*/ |
3647 | ||
b8698a0f | 3648 | static void |
3f9b14ff | 3649 | dse_step7 (void) |
6fb5fa3c | 3650 | { |
3f9b14ff SB |
3651 | bitmap_obstack_release (&dse_bitmap_obstack); |
3652 | obstack_free (&dse_obstack, NULL); | |
370f38e8 | 3653 | |
6fb5fa3c DB |
3654 | end_alias_analysis (); |
3655 | free (bb_table); | |
c203e8a7 TS |
3656 | delete rtx_group_table; |
3657 | rtx_group_table = NULL; | |
9771b263 | 3658 | rtx_group_vec.release (); |
6fb5fa3c DB |
3659 | BITMAP_FREE (all_blocks); |
3660 | BITMAP_FREE (scratch); | |
3661 | ||
da6603c6 | 3662 | rtx_store_info_pool.release (); |
fb0b2914 ML |
3663 | read_info_type_pool.release (); |
3664 | insn_info_type_pool.release (); | |
3665 | dse_bb_info_type_pool.release (); | |
3666 | group_info_pool.release (); | |
3667 | deferred_change_pool.release (); | |
6fb5fa3c DB |
3668 | } |
3669 | ||
3670 | ||
6fb5fa3c DB |
3671 | /* ------------------------------------------------------------------------- |
3672 | DSE | |
3673 | ------------------------------------------------------------------------- */ | |
3674 | ||
3675 | /* Callback for running pass_rtl_dse. */ | |
3676 | ||
3677 | static unsigned int | |
3678 | rest_of_handle_dse (void) | |
3679 | { | |
6fb5fa3c DB |
3680 | df_set_flags (DF_DEFER_INSN_RESCAN); |
3681 | ||
02b47899 KZ |
3682 | /* Need the notes since we must track live hardregs in the forwards |
3683 | direction. */ | |
3684 | df_note_add_problem (); | |
3685 | df_analyze (); | |
3686 | ||
6fb5fa3c DB |
3687 | dse_step0 (); |
3688 | dse_step1 (); | |
3689 | dse_step2_init (); | |
3690 | if (dse_step2_nospill ()) | |
3691 | { | |
3692 | df_set_flags (DF_LR_RUN_DCE); | |
3693 | df_analyze (); | |
456610d3 | 3694 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3695 | fprintf (dump_file, "doing global processing\n"); |
3696 | dse_step3 (false); | |
3697 | dse_step4 (); | |
3698 | dse_step5_nospill (); | |
3699 | } | |
3700 | ||
8dd5516b | 3701 | dse_step6 (); |
3f9b14ff | 3702 | dse_step7 (); |
6fb5fa3c DB |
3703 | |
3704 | if (dump_file) | |
3705 | fprintf (dump_file, "dse: local deletions = %d, global deletions = %d, spill deletions = %d\n", | |
3706 | locally_deleted, globally_deleted, spill_deleted); | |
6c5ed3f1 JJ |
3707 | |
3708 | /* DSE can eliminate potentially-trapping MEMs. | |
3709 | Remove any EH edges associated with them. */ | |
3710 | if ((locally_deleted || globally_deleted) | |
3711 | && cfun->can_throw_non_call_exceptions | |
3712 | && purge_all_dead_edges ()) | |
3713 | cleanup_cfg (0); | |
3714 | ||
6fb5fa3c DB |
3715 | return 0; |
3716 | } | |
3717 | ||
17795822 TS |
3718 | namespace { |
3719 | ||
3720 | const pass_data pass_data_rtl_dse1 = | |
27a4cd48 DM |
3721 | { |
3722 | RTL_PASS, /* type */ | |
3723 | "dse1", /* name */ | |
3724 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3725 | TV_DSE1, /* tv_id */ |
3726 | 0, /* properties_required */ | |
3727 | 0, /* properties_provided */ | |
3728 | 0, /* properties_destroyed */ | |
3729 | 0, /* todo_flags_start */ | |
3bea341f | 3730 | TODO_df_finish, /* todo_flags_finish */ |
6fb5fa3c DB |
3731 | }; |
3732 | ||
17795822 | 3733 | class pass_rtl_dse1 : public rtl_opt_pass |
27a4cd48 DM |
3734 | { |
3735 | public: | |
c3284718 RS |
3736 | pass_rtl_dse1 (gcc::context *ctxt) |
3737 | : rtl_opt_pass (pass_data_rtl_dse1, ctxt) | |
27a4cd48 DM |
3738 | {} |
3739 | ||
3740 | /* opt_pass methods: */ | |
1a3d085c TS |
3741 | virtual bool gate (function *) |
3742 | { | |
3743 | return optimize > 0 && flag_dse && dbg_cnt (dse1); | |
3744 | } | |
3745 | ||
be55bfe6 | 3746 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
27a4cd48 DM |
3747 | |
3748 | }; // class pass_rtl_dse1 | |
3749 | ||
17795822 TS |
3750 | } // anon namespace |
3751 | ||
27a4cd48 DM |
3752 | rtl_opt_pass * |
3753 | make_pass_rtl_dse1 (gcc::context *ctxt) | |
3754 | { | |
3755 | return new pass_rtl_dse1 (ctxt); | |
3756 | } | |
3757 | ||
17795822 TS |
3758 | namespace { |
3759 | ||
3760 | const pass_data pass_data_rtl_dse2 = | |
27a4cd48 DM |
3761 | { |
3762 | RTL_PASS, /* type */ | |
3763 | "dse2", /* name */ | |
3764 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3765 | TV_DSE2, /* tv_id */ |
3766 | 0, /* properties_required */ | |
3767 | 0, /* properties_provided */ | |
3768 | 0, /* properties_destroyed */ | |
3769 | 0, /* todo_flags_start */ | |
3bea341f | 3770 | TODO_df_finish, /* todo_flags_finish */ |
6fb5fa3c | 3771 | }; |
27a4cd48 | 3772 | |
17795822 | 3773 | class pass_rtl_dse2 : public rtl_opt_pass |
27a4cd48 DM |
3774 | { |
3775 | public: | |
c3284718 RS |
3776 | pass_rtl_dse2 (gcc::context *ctxt) |
3777 | : rtl_opt_pass (pass_data_rtl_dse2, ctxt) | |
27a4cd48 DM |
3778 | {} |
3779 | ||
3780 | /* opt_pass methods: */ | |
1a3d085c TS |
3781 | virtual bool gate (function *) |
3782 | { | |
3783 | return optimize > 0 && flag_dse && dbg_cnt (dse2); | |
3784 | } | |
3785 | ||
be55bfe6 | 3786 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
27a4cd48 DM |
3787 | |
3788 | }; // class pass_rtl_dse2 | |
3789 | ||
17795822 TS |
3790 | } // anon namespace |
3791 | ||
27a4cd48 DM |
3792 | rtl_opt_pass * |
3793 | make_pass_rtl_dse2 (gcc::context *ctxt) | |
3794 | { | |
3795 | return new pass_rtl_dse2 (ctxt); | |
3796 | } |