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6fb5fa3c | 1 | /* RTL dead store elimination. |
cbe34bb5 | 2 | Copyright (C) 2005-2017 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" |
957060b5 AM |
29 | #include "target.h" |
30 | #include "rtl.h" | |
c7131fb2 AM |
31 | #include "tree.h" |
32 | #include "gimple.h" | |
957060b5 | 33 | #include "predict.h" |
c7131fb2 | 34 | #include "df.h" |
4d0cdd0c | 35 | #include "memmodel.h" |
957060b5 AM |
36 | #include "tm_p.h" |
37 | #include "gimple-ssa.h" | |
38 | #include "expmed.h" | |
39 | #include "optabs.h" | |
957060b5 AM |
40 | #include "emit-rtl.h" |
41 | #include "recog.h" | |
40e23961 | 42 | #include "alias.h" |
d8a2d370 | 43 | #include "stor-layout.h" |
60393bbc | 44 | #include "cfgrtl.h" |
6fb5fa3c | 45 | #include "cselib.h" |
6fb5fa3c | 46 | #include "tree-pass.h" |
36566b39 | 47 | #include "explow.h" |
6fb5fa3c | 48 | #include "expr.h" |
6fb5fa3c | 49 | #include "dbgcnt.h" |
dabd47e7 | 50 | #include "params.h" |
d7111da8 | 51 | #include "rtl-iter.h" |
6c5ed3f1 | 52 | #include "cfgcleanup.h" |
6fb5fa3c DB |
53 | |
54 | /* This file contains three techniques for performing Dead Store | |
b8698a0f | 55 | Elimination (dse). |
6fb5fa3c DB |
56 | |
57 | * The first technique performs dse locally on any base address. It | |
58 | is based on the cselib which is a local value numbering technique. | |
59 | This technique is local to a basic block but deals with a fairly | |
60 | general addresses. | |
b8698a0f | 61 | |
6fb5fa3c DB |
62 | * The second technique performs dse globally but is restricted to |
63 | base addresses that are either constant or are relative to the | |
64 | frame_pointer. | |
65 | ||
66 | * The third technique, (which is only done after register allocation) | |
026c3cfd | 67 | processes the spill slots. This differs from the second |
6fb5fa3c DB |
68 | technique because it takes advantage of the fact that spilling is |
69 | completely free from the effects of aliasing. | |
70 | ||
71 | Logically, dse is a backwards dataflow problem. A store can be | |
72 | deleted if it if cannot be reached in the backward direction by any | |
73 | use of the value being stored. However, the local technique uses a | |
74 | forwards scan of the basic block because cselib requires that the | |
75 | block be processed in that order. | |
76 | ||
77 | The pass is logically broken into 7 steps: | |
78 | ||
79 | 0) Initialization. | |
80 | ||
81 | 1) The local algorithm, as well as scanning the insns for the two | |
82 | global algorithms. | |
83 | ||
84 | 2) Analysis to see if the global algs are necessary. In the case | |
85 | of stores base on a constant address, there must be at least two | |
86 | stores to that address, to make it possible to delete some of the | |
87 | stores. In the case of stores off of the frame or spill related | |
88 | stores, only one store to an address is necessary because those | |
89 | stores die at the end of the function. | |
90 | ||
b8698a0f | 91 | 3) Set up the global dataflow equations based on processing the |
6fb5fa3c DB |
92 | info parsed in the first step. |
93 | ||
94 | 4) Solve the dataflow equations. | |
95 | ||
96 | 5) Delete the insns that the global analysis has indicated are | |
97 | unnecessary. | |
98 | ||
073a8998 | 99 | 6) Delete insns that store the same value as preceding store |
8dd5516b JJ |
100 | where the earlier store couldn't be eliminated. |
101 | ||
102 | 7) Cleanup. | |
6fb5fa3c DB |
103 | |
104 | This step uses cselib and canon_rtx to build the largest expression | |
105 | possible for each address. This pass is a forwards pass through | |
106 | each basic block. From the point of view of the global technique, | |
107 | the first pass could examine a block in either direction. The | |
0d52bcc1 | 108 | forwards ordering is to accommodate cselib. |
6fb5fa3c | 109 | |
5ef0b50d | 110 | We make a simplifying assumption: addresses fall into four broad |
6fb5fa3c DB |
111 | categories: |
112 | ||
113 | 1) base has rtx_varies_p == false, offset is constant. | |
114 | 2) base has rtx_varies_p == false, offset variable. | |
115 | 3) base has rtx_varies_p == true, offset constant. | |
116 | 4) base has rtx_varies_p == true, offset variable. | |
117 | ||
118 | The local passes are able to process all 4 kinds of addresses. The | |
5ef0b50d | 119 | global pass only handles 1). |
6fb5fa3c DB |
120 | |
121 | The global problem is formulated as follows: | |
122 | ||
123 | A store, S1, to address A, where A is not relative to the stack | |
124 | frame, can be eliminated if all paths from S1 to the end of the | |
5ef0b50d | 125 | function contain another store to A before a read to A. |
6fb5fa3c DB |
126 | |
127 | If the address A is relative to the stack frame, a store S2 to A | |
5ef0b50d | 128 | can be eliminated if there are no paths from S2 that reach the |
6fb5fa3c | 129 | end of the function that read A before another store to A. In |
5ef0b50d | 130 | this case S2 can be deleted if there are paths from S2 to the |
6fb5fa3c DB |
131 | end of the function that have no reads or writes to A. This |
132 | second case allows stores to the stack frame to be deleted that | |
133 | would otherwise die when the function returns. This cannot be | |
134 | done if stores_off_frame_dead_at_return is not true. See the doc | |
135 | for that variable for when this variable is false. | |
136 | ||
137 | The global problem is formulated as a backwards set union | |
138 | dataflow problem where the stores are the gens and reads are the | |
139 | kills. Set union problems are rare and require some special | |
140 | handling given our representation of bitmaps. A straightforward | |
5ef0b50d | 141 | implementation requires a lot of bitmaps filled with 1s. |
6fb5fa3c DB |
142 | These are expensive and cumbersome in our bitmap formulation so |
143 | care has been taken to avoid large vectors filled with 1s. See | |
144 | the comments in bb_info and in the dataflow confluence functions | |
b8698a0f | 145 | for details. |
6fb5fa3c DB |
146 | |
147 | There are two places for further enhancements to this algorithm: | |
b8698a0f | 148 | |
6fb5fa3c DB |
149 | 1) The original dse which was embedded in a pass called flow also |
150 | did local address forwarding. For example in | |
151 | ||
152 | A <- r100 | |
153 | ... <- A | |
154 | ||
155 | flow would replace the right hand side of the second insn with a | |
6ed3da00 | 156 | reference to r100. Most of the information is available to add this |
6fb5fa3c DB |
157 | to this pass. It has not done it because it is a lot of work in |
158 | the case that either r100 is assigned to between the first and | |
159 | second insn and/or the second insn is a load of part of the value | |
160 | stored by the first insn. | |
161 | ||
162 | insn 5 in gcc.c-torture/compile/990203-1.c simple case. | |
163 | insn 15 in gcc.c-torture/execute/20001017-2.c simple case. | |
164 | insn 25 in gcc.c-torture/execute/20001026-1.c simple case. | |
165 | insn 44 in gcc.c-torture/execute/20010910-1.c simple case. | |
166 | ||
167 | 2) The cleaning up of spill code is quite profitable. It currently | |
168 | depends on reading tea leaves and chicken entrails left by reload. | |
169 | This pass depends on reload creating a singleton alias set for each | |
170 | spill slot and telling the next dse pass which of these alias sets | |
171 | are the singletons. Rather than analyze the addresses of the | |
172 | spills, dse's spill processing just does analysis of the loads and | |
173 | stores that use those alias sets. There are three cases where this | |
174 | falls short: | |
175 | ||
176 | a) Reload sometimes creates the slot for one mode of access, and | |
177 | then inserts loads and/or stores for a smaller mode. In this | |
178 | case, the current code just punts on the slot. The proper thing | |
179 | to do is to back out and use one bit vector position for each | |
180 | byte of the entity associated with the slot. This depends on | |
181 | KNOWING that reload always generates the accesses for each of the | |
182 | bytes in some canonical (read that easy to understand several | |
183 | passes after reload happens) way. | |
184 | ||
185 | b) Reload sometimes decides that spill slot it allocated was not | |
186 | large enough for the mode and goes back and allocates more slots | |
187 | with the same mode and alias set. The backout in this case is a | |
188 | little more graceful than (a). In this case the slot is unmarked | |
189 | as being a spill slot and if final address comes out to be based | |
b8698a0f | 190 | off the frame pointer, the global algorithm handles this slot. |
6fb5fa3c DB |
191 | |
192 | c) For any pass that may prespill, there is currently no | |
193 | mechanism to tell the dse pass that the slot being used has the | |
194 | special properties that reload uses. It may be that all that is | |
0d52bcc1 | 195 | required is to have those passes make the same calls that reload |
6fb5fa3c DB |
196 | does, assuming that the alias sets can be manipulated in the same |
197 | way. */ | |
198 | ||
199 | /* There are limits to the size of constant offsets we model for the | |
200 | global problem. There are certainly test cases, that exceed this | |
201 | limit, however, it is unlikely that there are important programs | |
202 | that really have constant offsets this size. */ | |
203 | #define MAX_OFFSET (64 * 1024) | |
204 | ||
3f9b14ff SB |
205 | /* Obstack for the DSE dataflow bitmaps. We don't want to put these |
206 | on the default obstack because these bitmaps can grow quite large | |
207 | (~2GB for the small (!) test case of PR54146) and we'll hold on to | |
208 | all that memory until the end of the compiler run. | |
209 | As a bonus, delete_tree_live_info can destroy all the bitmaps by just | |
210 | releasing the whole obstack. */ | |
211 | static bitmap_obstack dse_bitmap_obstack; | |
212 | ||
213 | /* Obstack for other data. As for above: Kinda nice to be able to | |
214 | throw it all away at the end in one big sweep. */ | |
215 | static struct obstack dse_obstack; | |
216 | ||
217 | /* Scratch bitmap for cselib's cselib_expand_value_rtx. */ | |
6fb5fa3c | 218 | static bitmap scratch = NULL; |
3f9b14ff | 219 | |
da6603c6 | 220 | struct insn_info_type; |
6fb5fa3c DB |
221 | |
222 | /* This structure holds information about a candidate store. */ | |
b8698a0f | 223 | struct store_info |
6fb5fa3c DB |
224 | { |
225 | ||
226 | /* False means this is a clobber. */ | |
227 | bool is_set; | |
228 | ||
8dd5516b JJ |
229 | /* False if a single HOST_WIDE_INT bitmap is used for positions_needed. */ |
230 | bool is_large; | |
231 | ||
6fb5fa3c DB |
232 | /* The id of the mem group of the base address. If rtx_varies_p is |
233 | true, this is -1. Otherwise, it is the index into the group | |
234 | table. */ | |
235 | int group_id; | |
b8698a0f | 236 | |
6fb5fa3c DB |
237 | /* This is the cselib value. */ |
238 | cselib_val *cse_base; | |
239 | ||
240 | /* This canonized mem. */ | |
241 | rtx mem; | |
242 | ||
6216f94e | 243 | /* Canonized MEM address for use by canon_true_dependence. */ |
6fb5fa3c DB |
244 | rtx mem_addr; |
245 | ||
71d6a386 RS |
246 | /* The offset of the first byte associated with the operation. */ |
247 | HOST_WIDE_INT offset; | |
248 | ||
249 | /* The number of bytes covered by the operation. This is always exact | |
250 | and known (rather than -1). */ | |
251 | HOST_WIDE_INT width; | |
8dd5516b JJ |
252 | |
253 | union | |
254 | { | |
255 | /* A bitmask as wide as the number of bytes in the word that | |
256 | contains a 1 if the byte may be needed. The store is unused if | |
257 | all of the bits are 0. This is used if IS_LARGE is false. */ | |
258 | unsigned HOST_WIDE_INT small_bitmask; | |
259 | ||
260 | struct | |
261 | { | |
262 | /* A bitmap with one bit per byte. Cleared bit means the position | |
263 | is needed. Used if IS_LARGE is false. */ | |
dc491a25 | 264 | bitmap bmap; |
6fb5fa3c | 265 | |
8dd5516b | 266 | /* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is |
71d6a386 | 267 | equal to WIDTH, the whole store is unused. */ |
8dd5516b JJ |
268 | int count; |
269 | } large; | |
270 | } positions_needed; | |
6fb5fa3c DB |
271 | |
272 | /* The next store info for this insn. */ | |
273 | struct store_info *next; | |
274 | ||
275 | /* The right hand side of the store. This is used if there is a | |
276 | subsequent reload of the mems address somewhere later in the | |
277 | basic block. */ | |
8dd5516b JJ |
278 | rtx rhs; |
279 | ||
280 | /* If rhs is or holds a constant, this contains that constant, | |
281 | otherwise NULL. */ | |
282 | rtx const_rhs; | |
283 | ||
284 | /* Set if this store stores the same constant value as REDUNDANT_REASON | |
285 | insn stored. These aren't eliminated early, because doing that | |
286 | might prevent the earlier larger store to be eliminated. */ | |
da6603c6 | 287 | struct insn_info_type *redundant_reason; |
6fb5fa3c DB |
288 | }; |
289 | ||
4fe663b0 L |
290 | /* Return a bitmask with the first N low bits set. */ |
291 | ||
292 | static unsigned HOST_WIDE_INT | |
293 | lowpart_bitmask (int n) | |
294 | { | |
dd4786fe | 295 | unsigned HOST_WIDE_INT mask = HOST_WIDE_INT_M1U; |
4fe663b0 L |
296 | return mask >> (HOST_BITS_PER_WIDE_INT - n); |
297 | } | |
298 | ||
fcb87c50 | 299 | static object_allocator<store_info> cse_store_info_pool ("cse_store_info_pool"); |
da6603c6 | 300 | |
fcb87c50 | 301 | static object_allocator<store_info> rtx_store_info_pool ("rtx_store_info_pool"); |
6fb5fa3c DB |
302 | |
303 | /* This structure holds information about a load. These are only | |
304 | built for rtx bases. */ | |
da6603c6 | 305 | struct read_info_type |
6fb5fa3c DB |
306 | { |
307 | /* The id of the mem group of the base address. */ | |
308 | int group_id; | |
309 | ||
71d6a386 RS |
310 | /* The offset of the first byte associated with the operation. */ |
311 | HOST_WIDE_INT offset; | |
312 | ||
313 | /* The number of bytes covered by the operation, or -1 if not known. */ | |
314 | HOST_WIDE_INT width; | |
6fb5fa3c DB |
315 | |
316 | /* The mem being read. */ | |
317 | rtx mem; | |
318 | ||
319 | /* The next read_info for this insn. */ | |
da6603c6 | 320 | struct read_info_type *next; |
6fb5fa3c | 321 | }; |
da6603c6 | 322 | typedef struct read_info_type *read_info_t; |
6fb5fa3c | 323 | |
fcb87c50 | 324 | static object_allocator<read_info_type> read_info_type_pool ("read_info_pool"); |
6fb5fa3c DB |
325 | |
326 | /* One of these records is created for each insn. */ | |
327 | ||
da6603c6 | 328 | struct insn_info_type |
6fb5fa3c DB |
329 | { |
330 | /* Set true if the insn contains a store but the insn itself cannot | |
331 | be deleted. This is set if the insn is a parallel and there is | |
332 | more than one non dead output or if the insn is in some way | |
333 | volatile. */ | |
334 | bool cannot_delete; | |
335 | ||
336 | /* This field is only used by the global algorithm. It is set true | |
337 | if the insn contains any read of mem except for a (1). This is | |
338 | also set if the insn is a call or has a clobber mem. If the insn | |
339 | contains a wild read, the use_rec will be null. */ | |
340 | bool wild_read; | |
341 | ||
d26c7090 ER |
342 | /* This is true only for CALL instructions which could potentially read |
343 | any non-frame memory location. This field is used by the global | |
344 | algorithm. */ | |
345 | bool non_frame_wild_read; | |
346 | ||
50f0f366 EB |
347 | /* This field is only used for the processing of const functions. |
348 | These functions cannot read memory, but they can read the stack | |
64520bdc EB |
349 | because that is where they may get their parms. We need to be |
350 | this conservative because, like the store motion pass, we don't | |
351 | consider CALL_INSN_FUNCTION_USAGE when processing call insns. | |
352 | Moreover, we need to distinguish two cases: | |
353 | 1. Before reload (register elimination), the stores related to | |
354 | outgoing arguments are stack pointer based and thus deemed | |
355 | of non-constant base in this pass. This requires special | |
356 | handling but also means that the frame pointer based stores | |
357 | need not be killed upon encountering a const function call. | |
358 | 2. After reload, the stores related to outgoing arguments can be | |
359 | either stack pointer or hard frame pointer based. This means | |
360 | that we have no other choice than also killing all the frame | |
361 | pointer based stores upon encountering a const function call. | |
57534689 JJ |
362 | This field is set after reload for const function calls and before |
363 | reload for const tail function calls on targets where arg pointer | |
364 | is the frame pointer. Having this set is less severe than a wild | |
365 | read, it just means that all the frame related stores are killed | |
366 | rather than all the stores. */ | |
64520bdc EB |
367 | bool frame_read; |
368 | ||
369 | /* This field is only used for the processing of const functions. | |
370 | It is set if the insn may contain a stack pointer based store. */ | |
50f0f366 | 371 | bool stack_pointer_based; |
6fb5fa3c DB |
372 | |
373 | /* This is true if any of the sets within the store contains a | |
374 | cselib base. Such stores can only be deleted by the local | |
375 | algorithm. */ | |
376 | bool contains_cselib_groups; | |
377 | ||
378 | /* The insn. */ | |
dd60a84c | 379 | rtx_insn *insn; |
6fb5fa3c DB |
380 | |
381 | /* The list of mem sets or mem clobbers that are contained in this | |
382 | insn. If the insn is deletable, it contains only one mem set. | |
383 | But it could also contain clobbers. Insns that contain more than | |
384 | one mem set are not deletable, but each of those mems are here in | |
6ed3da00 | 385 | order to provide info to delete other insns. */ |
fd6daec9 | 386 | store_info *store_rec; |
6fb5fa3c DB |
387 | |
388 | /* The linked list of mem uses in this insn. Only the reads from | |
389 | rtx bases are listed here. The reads to cselib bases are | |
390 | completely processed during the first scan and so are never | |
391 | created. */ | |
392 | read_info_t read_rec; | |
393 | ||
9e582b1d JR |
394 | /* The live fixed registers. We assume only fixed registers can |
395 | cause trouble by being clobbered from an expanded pattern; | |
396 | storing only the live fixed registers (rather than all registers) | |
397 | means less memory needs to be allocated / copied for the individual | |
398 | stores. */ | |
399 | regset fixed_regs_live; | |
400 | ||
6fb5fa3c | 401 | /* The prev insn in the basic block. */ |
da6603c6 | 402 | struct insn_info_type * prev_insn; |
6fb5fa3c DB |
403 | |
404 | /* The linked list of insns that are in consideration for removal in | |
073a8998 | 405 | the forwards pass through the basic block. This pointer may be |
6fb5fa3c | 406 | trash as it is not cleared when a wild read occurs. The only |
fa10beec | 407 | time it is guaranteed to be correct is when the traversal starts |
6fb5fa3c | 408 | at active_local_stores. */ |
da6603c6 | 409 | struct insn_info_type * next_local_store; |
6fb5fa3c | 410 | }; |
da6603c6 | 411 | typedef struct insn_info_type *insn_info_t; |
6fb5fa3c | 412 | |
fcb87c50 | 413 | static object_allocator<insn_info_type> insn_info_type_pool ("insn_info_pool"); |
6fb5fa3c DB |
414 | |
415 | /* The linked list of stores that are under consideration in this | |
b8698a0f | 416 | basic block. */ |
6fb5fa3c | 417 | static insn_info_t active_local_stores; |
dabd47e7 | 418 | static int active_local_stores_len; |
6fb5fa3c | 419 | |
da6603c6 | 420 | struct dse_bb_info_type |
6fb5fa3c | 421 | { |
6fb5fa3c DB |
422 | /* Pointer to the insn info for the last insn in the block. These |
423 | are linked so this is how all of the insns are reached. During | |
424 | scanning this is the current insn being scanned. */ | |
425 | insn_info_t last_insn; | |
426 | ||
427 | /* The info for the global dataflow problem. */ | |
428 | ||
429 | ||
430 | /* This is set if the transfer function should and in the wild_read | |
431 | bitmap before applying the kill and gen sets. That vector knocks | |
432 | out most of the bits in the bitmap and thus speeds up the | |
433 | operations. */ | |
434 | bool apply_wild_read; | |
435 | ||
02b47899 KZ |
436 | /* The following 4 bitvectors hold information about which positions |
437 | of which stores are live or dead. They are indexed by | |
438 | get_bitmap_index. */ | |
439 | ||
6fb5fa3c DB |
440 | /* The set of store positions that exist in this block before a wild read. */ |
441 | bitmap gen; | |
b8698a0f | 442 | |
6fb5fa3c DB |
443 | /* The set of load positions that exist in this block above the |
444 | same position of a store. */ | |
445 | bitmap kill; | |
446 | ||
447 | /* The set of stores that reach the top of the block without being | |
448 | killed by a read. | |
449 | ||
450 | Do not represent the in if it is all ones. Note that this is | |
451 | what the bitvector should logically be initialized to for a set | |
452 | intersection problem. However, like the kill set, this is too | |
453 | expensive. So initially, the in set will only be created for the | |
454 | exit block and any block that contains a wild read. */ | |
455 | bitmap in; | |
456 | ||
457 | /* The set of stores that reach the bottom of the block from it's | |
458 | successors. | |
459 | ||
460 | Do not represent the in if it is all ones. Note that this is | |
461 | what the bitvector should logically be initialized to for a set | |
462 | intersection problem. However, like the kill and in set, this is | |
463 | too expensive. So what is done is that the confluence operator | |
464 | just initializes the vector from one of the out sets of the | |
465 | successors of the block. */ | |
466 | bitmap out; | |
02b47899 KZ |
467 | |
468 | /* The following bitvector is indexed by the reg number. It | |
469 | contains the set of regs that are live at the current instruction | |
470 | being processed. While it contains info for all of the | |
9e582b1d JR |
471 | registers, only the hard registers are actually examined. It is used |
472 | to assure that shift and/or add sequences that are inserted do not | |
073a8998 | 473 | accidentally clobber live hard regs. */ |
02b47899 | 474 | bitmap regs_live; |
6fb5fa3c DB |
475 | }; |
476 | ||
da6603c6 | 477 | typedef struct dse_bb_info_type *bb_info_t; |
fb0b2914 ML |
478 | |
479 | static object_allocator<dse_bb_info_type> dse_bb_info_type_pool | |
fcb87c50 | 480 | ("bb_info_pool"); |
6fb5fa3c DB |
481 | |
482 | /* Table to hold all bb_infos. */ | |
483 | static bb_info_t *bb_table; | |
484 | ||
485 | /* There is a group_info for each rtx base that is used to reference | |
486 | memory. There are also not many of the rtx bases because they are | |
487 | very limited in scope. */ | |
488 | ||
b8698a0f | 489 | struct group_info |
6fb5fa3c DB |
490 | { |
491 | /* The actual base of the address. */ | |
492 | rtx rtx_base; | |
493 | ||
494 | /* The sequential id of the base. This allows us to have a | |
495 | canonical ordering of these that is not based on addresses. */ | |
496 | int id; | |
497 | ||
8f5929e1 JJ |
498 | /* True if there are any positions that are to be processed |
499 | globally. */ | |
500 | bool process_globally; | |
501 | ||
502 | /* True if the base of this group is either the frame_pointer or | |
503 | hard_frame_pointer. */ | |
504 | bool frame_related; | |
505 | ||
d32f725a OH |
506 | /* A mem wrapped around the base pointer for the group in order to do |
507 | read dependency. It must be given BLKmode in order to encompass all | |
508 | the possible offsets from the base. */ | |
6fb5fa3c | 509 | rtx base_mem; |
b8698a0f | 510 | |
6216f94e JJ |
511 | /* Canonized version of base_mem's address. */ |
512 | rtx canon_base_addr; | |
6fb5fa3c DB |
513 | |
514 | /* These two sets of two bitmaps are used to keep track of how many | |
6ed3da00 | 515 | stores are actually referencing that position from this base. We |
6fb5fa3c | 516 | only do this for rtx bases as this will be used to assign |
6ed3da00 | 517 | positions in the bitmaps for the global problem. Bit N is set in |
6fb5fa3c DB |
518 | store1 on the first store for offset N. Bit N is set in store2 |
519 | for the second store to offset N. This is all we need since we | |
520 | only care about offsets that have two or more stores for them. | |
521 | ||
522 | The "_n" suffix is for offsets less than 0 and the "_p" suffix is | |
523 | for 0 and greater offsets. | |
524 | ||
525 | There is one special case here, for stores into the stack frame, | |
526 | we will or store1 into store2 before deciding which stores look | |
527 | at globally. This is because stores to the stack frame that have | |
528 | no other reads before the end of the function can also be | |
529 | deleted. */ | |
530 | bitmap store1_n, store1_p, store2_n, store2_p; | |
531 | ||
d26c7090 ER |
532 | /* These bitmaps keep track of offsets in this group escape this function. |
533 | An offset escapes if it corresponds to a named variable whose | |
534 | addressable flag is set. */ | |
535 | bitmap escaped_n, escaped_p; | |
536 | ||
6ed3da00 | 537 | /* The positions in this bitmap have the same assignments as the in, |
6fb5fa3c | 538 | out, gen and kill bitmaps. This bitmap is all zeros except for |
6ed3da00 | 539 | the positions that are occupied by stores for this group. */ |
6fb5fa3c DB |
540 | bitmap group_kill; |
541 | ||
6fb5fa3c | 542 | /* The offset_map is used to map the offsets from this base into |
6ed3da00 | 543 | positions in the global bitmaps. It is only created after all of |
6fb5fa3c DB |
544 | the all of stores have been scanned and we know which ones we |
545 | care about. */ | |
b8698a0f L |
546 | int *offset_map_n, *offset_map_p; |
547 | int offset_map_size_n, offset_map_size_p; | |
6fb5fa3c | 548 | }; |
da6603c6 | 549 | |
fcb87c50 | 550 | static object_allocator<group_info> group_info_pool ("rtx_group_info_pool"); |
6fb5fa3c | 551 | |
6fb5fa3c DB |
552 | /* Index into the rtx_group_vec. */ |
553 | static int rtx_group_next_id; | |
554 | ||
6fb5fa3c | 555 | |
fd6daec9 | 556 | static vec<group_info *> rtx_group_vec; |
6fb5fa3c DB |
557 | |
558 | ||
559 | /* This structure holds the set of changes that are being deferred | |
560 | when removing read operation. See replace_read. */ | |
b8698a0f | 561 | struct deferred_change |
6fb5fa3c DB |
562 | { |
563 | ||
564 | /* The mem that is being replaced. */ | |
565 | rtx *loc; | |
566 | ||
567 | /* The reg it is being replaced with. */ | |
568 | rtx reg; | |
569 | ||
570 | struct deferred_change *next; | |
571 | }; | |
572 | ||
fb0b2914 | 573 | static object_allocator<deferred_change> deferred_change_pool |
fcb87c50 | 574 | ("deferred_change_pool"); |
6fb5fa3c | 575 | |
fd6daec9 | 576 | static deferred_change *deferred_change_list = NULL; |
6fb5fa3c | 577 | |
e3b5732b | 578 | /* This is true except if cfun->stdarg -- i.e. we cannot do |
9dd9bf80 | 579 | this for vararg functions because they play games with the frame. */ |
6fb5fa3c DB |
580 | static bool stores_off_frame_dead_at_return; |
581 | ||
582 | /* Counter for stats. */ | |
b8698a0f L |
583 | static int globally_deleted; |
584 | static int locally_deleted; | |
b8698a0f | 585 | |
6fb5fa3c DB |
586 | static bitmap all_blocks; |
587 | ||
d26c7090 ER |
588 | /* Locations that are killed by calls in the global phase. */ |
589 | static bitmap kill_on_calls; | |
590 | ||
6fb5fa3c DB |
591 | /* The number of bits used in the global bitmaps. */ |
592 | static unsigned int current_position; | |
71d6a386 RS |
593 | |
594 | /* Print offset range [OFFSET, OFFSET + WIDTH) to FILE. */ | |
595 | ||
596 | static void | |
597 | print_range (FILE *file, poly_int64 offset, poly_int64 width) | |
598 | { | |
599 | fprintf (file, "["); | |
600 | print_dec (offset, file, SIGNED); | |
601 | fprintf (file, ".."); | |
602 | print_dec (offset + width, file, SIGNED); | |
603 | fprintf (file, ")"); | |
604 | } | |
6fb5fa3c DB |
605 | \f |
606 | /*---------------------------------------------------------------------------- | |
607 | Zeroth step. | |
608 | ||
b8698a0f | 609 | Initialization. |
6fb5fa3c DB |
610 | ----------------------------------------------------------------------------*/ |
611 | ||
6fb5fa3c | 612 | |
6fb5fa3c DB |
613 | /* Hashtable callbacks for maintaining the "bases" field of |
614 | store_group_info, given that the addresses are function invariants. */ | |
615 | ||
8d67ee55 | 616 | struct invariant_group_base_hasher : nofree_ptr_hash <group_info> |
703c8606 | 617 | { |
67f58944 TS |
618 | static inline hashval_t hash (const group_info *); |
619 | static inline bool equal (const group_info *, const group_info *); | |
703c8606 LC |
620 | }; |
621 | ||
622 | inline bool | |
67f58944 TS |
623 | invariant_group_base_hasher::equal (const group_info *gi1, |
624 | const group_info *gi2) | |
6fb5fa3c | 625 | { |
6fb5fa3c DB |
626 | return rtx_equal_p (gi1->rtx_base, gi2->rtx_base); |
627 | } | |
628 | ||
703c8606 | 629 | inline hashval_t |
67f58944 | 630 | invariant_group_base_hasher::hash (const group_info *gi) |
6fb5fa3c | 631 | { |
6fb5fa3c DB |
632 | int do_not_record; |
633 | return hash_rtx (gi->rtx_base, Pmode, &do_not_record, NULL, false); | |
634 | } | |
635 | ||
703c8606 | 636 | /* Tables of group_info structures, hashed by base value. */ |
c203e8a7 | 637 | static hash_table<invariant_group_base_hasher> *rtx_group_table; |
703c8606 | 638 | |
6fb5fa3c DB |
639 | |
640 | /* Get the GROUP for BASE. Add a new group if it is not there. */ | |
641 | ||
fd6daec9 | 642 | static group_info * |
6fb5fa3c DB |
643 | get_group_info (rtx base) |
644 | { | |
b8698a0f | 645 | struct group_info tmp_gi; |
fd6daec9 | 646 | group_info *gi; |
703c8606 | 647 | group_info **slot; |
6fb5fa3c | 648 | |
ac6929b5 RB |
649 | gcc_assert (base != NULL_RTX); |
650 | ||
651 | /* Find the store_base_info structure for BASE, creating a new one | |
652 | if necessary. */ | |
653 | tmp_gi.rtx_base = base; | |
654 | slot = rtx_group_table->find_slot (&tmp_gi, INSERT); | |
655 | gi = *slot; | |
6fb5fa3c DB |
656 | |
657 | if (gi == NULL) | |
658 | { | |
fb0b2914 | 659 | *slot = gi = group_info_pool.allocate (); |
6fb5fa3c DB |
660 | gi->rtx_base = base; |
661 | gi->id = rtx_group_next_id++; | |
d32f725a | 662 | gi->base_mem = gen_rtx_MEM (BLKmode, base); |
6216f94e | 663 | gi->canon_base_addr = canon_rtx (base); |
3f9b14ff SB |
664 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
665 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
666 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
667 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
668 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
669 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
670 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c | 671 | gi->process_globally = false; |
b8698a0f | 672 | gi->frame_related = |
6fb5fa3c DB |
673 | (base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx); |
674 | gi->offset_map_size_n = 0; | |
675 | gi->offset_map_size_p = 0; | |
676 | gi->offset_map_n = NULL; | |
677 | gi->offset_map_p = NULL; | |
9771b263 | 678 | rtx_group_vec.safe_push (gi); |
6fb5fa3c DB |
679 | } |
680 | ||
681 | return gi; | |
682 | } | |
683 | ||
684 | ||
685 | /* Initialization of data structures. */ | |
686 | ||
687 | static void | |
688 | dse_step0 (void) | |
689 | { | |
690 | locally_deleted = 0; | |
691 | globally_deleted = 0; | |
6fb5fa3c | 692 | |
3f9b14ff SB |
693 | bitmap_obstack_initialize (&dse_bitmap_obstack); |
694 | gcc_obstack_init (&dse_obstack); | |
695 | ||
696 | scratch = BITMAP_ALLOC (®_obstack); | |
697 | kill_on_calls = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c | 698 | |
6fb5fa3c | 699 | |
c203e8a7 | 700 | rtx_group_table = new hash_table<invariant_group_base_hasher> (11); |
6fb5fa3c | 701 | |
8b1c6fd7 | 702 | bb_table = XNEWVEC (bb_info_t, last_basic_block_for_fn (cfun)); |
6fb5fa3c DB |
703 | rtx_group_next_id = 0; |
704 | ||
e3b5732b | 705 | stores_off_frame_dead_at_return = !cfun->stdarg; |
6fb5fa3c DB |
706 | |
707 | init_alias_analysis (); | |
6fb5fa3c DB |
708 | } |
709 | ||
710 | ||
711 | \f | |
712 | /*---------------------------------------------------------------------------- | |
713 | First step. | |
714 | ||
715 | Scan all of the insns. Any random ordering of the blocks is fine. | |
0d52bcc1 | 716 | Each block is scanned in forward order to accommodate cselib which |
6fb5fa3c DB |
717 | is used to remove stores with non-constant bases. |
718 | ----------------------------------------------------------------------------*/ | |
719 | ||
720 | /* Delete all of the store_info recs from INSN_INFO. */ | |
721 | ||
b8698a0f | 722 | static void |
6fb5fa3c DB |
723 | free_store_info (insn_info_t insn_info) |
724 | { | |
fd6daec9 TS |
725 | store_info *cur = insn_info->store_rec; |
726 | while (cur) | |
6fb5fa3c | 727 | { |
fd6daec9 TS |
728 | store_info *next = cur->next; |
729 | if (cur->is_large) | |
730 | BITMAP_FREE (cur->positions_needed.large.bmap); | |
731 | if (cur->cse_base) | |
732 | cse_store_info_pool.remove (cur); | |
6fb5fa3c | 733 | else |
fd6daec9 TS |
734 | rtx_store_info_pool.remove (cur); |
735 | cur = next; | |
6fb5fa3c DB |
736 | } |
737 | ||
738 | insn_info->cannot_delete = true; | |
739 | insn_info->contains_cselib_groups = false; | |
740 | insn_info->store_rec = NULL; | |
741 | } | |
742 | ||
a79683d5 | 743 | struct note_add_store_info |
9e582b1d | 744 | { |
dc01c3d1 | 745 | rtx_insn *first, *current; |
9e582b1d JR |
746 | regset fixed_regs_live; |
747 | bool failure; | |
a79683d5 | 748 | }; |
9e582b1d JR |
749 | |
750 | /* Callback for emit_inc_dec_insn_before via note_stores. | |
751 | Check if a register is clobbered which is live afterwards. */ | |
752 | ||
753 | static void | |
754 | note_add_store (rtx loc, const_rtx expr ATTRIBUTE_UNUSED, void *data) | |
755 | { | |
dc01c3d1 | 756 | rtx_insn *insn; |
9e582b1d | 757 | note_add_store_info *info = (note_add_store_info *) data; |
9e582b1d JR |
758 | |
759 | if (!REG_P (loc)) | |
760 | return; | |
761 | ||
762 | /* If this register is referenced by the current or an earlier insn, | |
763 | that's OK. E.g. this applies to the register that is being incremented | |
764 | with this addition. */ | |
765 | for (insn = info->first; | |
766 | insn != NEXT_INSN (info->current); | |
767 | insn = NEXT_INSN (insn)) | |
768 | if (reg_referenced_p (loc, PATTERN (insn))) | |
769 | return; | |
770 | ||
771 | /* If we come here, we have a clobber of a register that's only OK | |
772 | if that register is not live. If we don't have liveness information | |
773 | available, fail now. */ | |
774 | if (!info->fixed_regs_live) | |
775 | { | |
53d1bae9 | 776 | info->failure = true; |
9e582b1d JR |
777 | return; |
778 | } | |
779 | /* Now check if this is a live fixed register. */ | |
53d1bae9 RS |
780 | unsigned int end_regno = END_REGNO (loc); |
781 | for (unsigned int regno = REGNO (loc); regno < end_regno; ++regno) | |
782 | if (REGNO_REG_SET_P (info->fixed_regs_live, regno)) | |
783 | info->failure = true; | |
9e582b1d JR |
784 | } |
785 | ||
4deef538 AO |
786 | /* Callback for for_each_inc_dec that emits an INSN that sets DEST to |
787 | SRC + SRCOFF before insn ARG. */ | |
6fb5fa3c DB |
788 | |
789 | static int | |
4deef538 AO |
790 | emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED, |
791 | rtx op ATTRIBUTE_UNUSED, | |
792 | rtx dest, rtx src, rtx srcoff, void *arg) | |
6fb5fa3c | 793 | { |
9e582b1d | 794 | insn_info_t insn_info = (insn_info_t) arg; |
dc01c3d1 | 795 | rtx_insn *insn = insn_info->insn, *new_insn, *cur; |
9e582b1d | 796 | note_add_store_info info; |
b8698a0f | 797 | |
4deef538 AO |
798 | /* We can reuse all operands without copying, because we are about |
799 | to delete the insn that contained it. */ | |
9e582b1d | 800 | if (srcoff) |
ed079c4b JJ |
801 | { |
802 | start_sequence (); | |
803 | emit_insn (gen_add3_insn (dest, src, srcoff)); | |
804 | new_insn = get_insns (); | |
805 | end_sequence (); | |
806 | } | |
9e582b1d | 807 | else |
1476d1bd | 808 | new_insn = gen_move_insn (dest, src); |
9e582b1d JR |
809 | info.first = new_insn; |
810 | info.fixed_regs_live = insn_info->fixed_regs_live; | |
811 | info.failure = false; | |
812 | for (cur = new_insn; cur; cur = NEXT_INSN (cur)) | |
813 | { | |
814 | info.current = cur; | |
815 | note_stores (PATTERN (cur), note_add_store, &info); | |
816 | } | |
6fb5fa3c | 817 | |
9e582b1d JR |
818 | /* If a failure was flagged above, return 1 so that for_each_inc_dec will |
819 | return it immediately, communicating the failure to its caller. */ | |
820 | if (info.failure) | |
821 | return 1; | |
822 | ||
823 | emit_insn_before (new_insn, insn); | |
6fb5fa3c | 824 | |
8d8e205b | 825 | return 0; |
6fb5fa3c DB |
826 | } |
827 | ||
9e582b1d JR |
828 | /* Before we delete INSN_INFO->INSN, make sure that the auto inc/dec, if it |
829 | is there, is split into a separate insn. | |
830 | Return true on success (or if there was nothing to do), false on failure. */ | |
6fb5fa3c | 831 | |
9e582b1d JR |
832 | static bool |
833 | check_for_inc_dec_1 (insn_info_t insn_info) | |
6fb5fa3c | 834 | { |
dd60a84c | 835 | rtx_insn *insn = insn_info->insn; |
6fb5fa3c DB |
836 | rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
837 | if (note) | |
8d8e205b RS |
838 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
839 | insn_info) == 0; | |
9e582b1d | 840 | return true; |
6fb5fa3c DB |
841 | } |
842 | ||
843 | ||
9e582b1d JR |
844 | /* Entry point for postreload. If you work on reload_cse, or you need this |
845 | anywhere else, consider if you can provide register liveness information | |
846 | and add a parameter to this function so that it can be passed down in | |
847 | insn_info.fixed_regs_live. */ | |
848 | bool | |
dd60a84c | 849 | check_for_inc_dec (rtx_insn *insn) |
9e582b1d | 850 | { |
da6603c6 | 851 | insn_info_type insn_info; |
9e582b1d JR |
852 | rtx note; |
853 | ||
854 | insn_info.insn = insn; | |
855 | insn_info.fixed_regs_live = NULL; | |
856 | note = find_reg_note (insn, REG_INC, NULL_RTX); | |
857 | if (note) | |
8d8e205b RS |
858 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
859 | &insn_info) == 0; | |
9e582b1d JR |
860 | return true; |
861 | } | |
862 | ||
b8698a0f | 863 | /* Delete the insn and free all of the fields inside INSN_INFO. */ |
6fb5fa3c DB |
864 | |
865 | static void | |
866 | delete_dead_store_insn (insn_info_t insn_info) | |
867 | { | |
868 | read_info_t read_info; | |
869 | ||
870 | if (!dbg_cnt (dse)) | |
871 | return; | |
872 | ||
9e582b1d JR |
873 | if (!check_for_inc_dec_1 (insn_info)) |
874 | return; | |
456610d3 | 875 | if (dump_file && (dump_flags & TDF_DETAILS)) |
ac6929b5 RB |
876 | fprintf (dump_file, "Locally deleting insn %d\n", |
877 | INSN_UID (insn_info->insn)); | |
6fb5fa3c DB |
878 | |
879 | free_store_info (insn_info); | |
880 | read_info = insn_info->read_rec; | |
b8698a0f | 881 | |
6fb5fa3c DB |
882 | while (read_info) |
883 | { | |
884 | read_info_t next = read_info->next; | |
fb0b2914 | 885 | read_info_type_pool.remove (read_info); |
6fb5fa3c DB |
886 | read_info = next; |
887 | } | |
888 | insn_info->read_rec = NULL; | |
889 | ||
890 | delete_insn (insn_info->insn); | |
891 | locally_deleted++; | |
892 | insn_info->insn = NULL; | |
893 | ||
894 | insn_info->wild_read = false; | |
895 | } | |
896 | ||
88d8330d EB |
897 | /* Return whether DECL, a local variable, can possibly escape the current |
898 | function scope. */ | |
899 | ||
900 | static bool | |
901 | local_variable_can_escape (tree decl) | |
902 | { | |
903 | if (TREE_ADDRESSABLE (decl)) | |
904 | return true; | |
905 | ||
906 | /* If this is a partitioned variable, we need to consider all the variables | |
907 | in the partition. This is necessary because a store into one of them can | |
908 | be replaced with a store into another and this may not change the outcome | |
909 | of the escape analysis. */ | |
910 | if (cfun->gimple_df->decls_to_pointers != NULL) | |
911 | { | |
39c8aaa4 | 912 | tree *namep = cfun->gimple_df->decls_to_pointers->get (decl); |
88d8330d | 913 | if (namep) |
39c8aaa4 | 914 | return TREE_ADDRESSABLE (*namep); |
88d8330d EB |
915 | } |
916 | ||
917 | return false; | |
918 | } | |
919 | ||
920 | /* Return whether EXPR can possibly escape the current function scope. */ | |
921 | ||
d26c7090 ER |
922 | static bool |
923 | can_escape (tree expr) | |
924 | { | |
925 | tree base; | |
926 | if (!expr) | |
927 | return true; | |
928 | base = get_base_address (expr); | |
929 | if (DECL_P (base) | |
88d8330d | 930 | && !may_be_aliased (base) |
8813a647 | 931 | && !(VAR_P (base) |
88d8330d EB |
932 | && !DECL_EXTERNAL (base) |
933 | && !TREE_STATIC (base) | |
934 | && local_variable_can_escape (base))) | |
d26c7090 ER |
935 | return false; |
936 | return true; | |
937 | } | |
6fb5fa3c DB |
938 | |
939 | /* Set the store* bitmaps offset_map_size* fields in GROUP based on | |
940 | OFFSET and WIDTH. */ | |
941 | ||
942 | static void | |
fd6daec9 | 943 | set_usage_bits (group_info *group, HOST_WIDE_INT offset, HOST_WIDE_INT width, |
d26c7090 | 944 | tree expr) |
6fb5fa3c DB |
945 | { |
946 | HOST_WIDE_INT i; | |
d26c7090 | 947 | bool expr_escapes = can_escape (expr); |
8dd5516b | 948 | if (offset > -MAX_OFFSET && offset + width < MAX_OFFSET) |
6fb5fa3c DB |
949 | for (i=offset; i<offset+width; i++) |
950 | { | |
951 | bitmap store1; | |
952 | bitmap store2; | |
d26c7090 | 953 | bitmap escaped; |
6fb5fa3c DB |
954 | int ai; |
955 | if (i < 0) | |
956 | { | |
957 | store1 = group->store1_n; | |
958 | store2 = group->store2_n; | |
d26c7090 | 959 | escaped = group->escaped_n; |
6fb5fa3c DB |
960 | ai = -i; |
961 | } | |
962 | else | |
963 | { | |
964 | store1 = group->store1_p; | |
965 | store2 = group->store2_p; | |
d26c7090 | 966 | escaped = group->escaped_p; |
6fb5fa3c DB |
967 | ai = i; |
968 | } | |
b8698a0f | 969 | |
fcaa4ca4 | 970 | if (!bitmap_set_bit (store1, ai)) |
6fb5fa3c | 971 | bitmap_set_bit (store2, ai); |
b8698a0f | 972 | else |
6fb5fa3c | 973 | { |
6fb5fa3c DB |
974 | if (i < 0) |
975 | { | |
976 | if (group->offset_map_size_n < ai) | |
977 | group->offset_map_size_n = ai; | |
978 | } | |
979 | else | |
980 | { | |
981 | if (group->offset_map_size_p < ai) | |
982 | group->offset_map_size_p = ai; | |
983 | } | |
984 | } | |
d26c7090 ER |
985 | if (expr_escapes) |
986 | bitmap_set_bit (escaped, ai); | |
6fb5fa3c DB |
987 | } |
988 | } | |
989 | ||
d26c7090 ER |
990 | static void |
991 | reset_active_stores (void) | |
992 | { | |
993 | active_local_stores = NULL; | |
994 | active_local_stores_len = 0; | |
995 | } | |
6fb5fa3c | 996 | |
d26c7090 | 997 | /* Free all READ_REC of the LAST_INSN of BB_INFO. */ |
6fb5fa3c DB |
998 | |
999 | static void | |
d26c7090 | 1000 | free_read_records (bb_info_t bb_info) |
6fb5fa3c DB |
1001 | { |
1002 | insn_info_t insn_info = bb_info->last_insn; | |
1003 | read_info_t *ptr = &insn_info->read_rec; | |
6fb5fa3c DB |
1004 | while (*ptr) |
1005 | { | |
1006 | read_info_t next = (*ptr)->next; | |
ac6929b5 RB |
1007 | read_info_type_pool.remove (*ptr); |
1008 | *ptr = next; | |
6fb5fa3c | 1009 | } |
d26c7090 ER |
1010 | } |
1011 | ||
1012 | /* Set the BB_INFO so that the last insn is marked as a wild read. */ | |
1013 | ||
1014 | static void | |
1015 | add_wild_read (bb_info_t bb_info) | |
1016 | { | |
1017 | insn_info_t insn_info = bb_info->last_insn; | |
6fb5fa3c | 1018 | insn_info->wild_read = true; |
d26c7090 ER |
1019 | free_read_records (bb_info); |
1020 | reset_active_stores (); | |
6fb5fa3c DB |
1021 | } |
1022 | ||
d26c7090 ER |
1023 | /* Set the BB_INFO so that the last insn is marked as a wild read of |
1024 | non-frame locations. */ | |
1025 | ||
1026 | static void | |
1027 | add_non_frame_wild_read (bb_info_t bb_info) | |
1028 | { | |
1029 | insn_info_t insn_info = bb_info->last_insn; | |
1030 | insn_info->non_frame_wild_read = true; | |
1031 | free_read_records (bb_info); | |
1032 | reset_active_stores (); | |
1033 | } | |
6fb5fa3c | 1034 | |
50f0f366 EB |
1035 | /* Return true if X is a constant or one of the registers that behave |
1036 | as a constant over the life of a function. This is equivalent to | |
1037 | !rtx_varies_p for memory addresses. */ | |
6fb5fa3c DB |
1038 | |
1039 | static bool | |
1040 | const_or_frame_p (rtx x) | |
1041 | { | |
d8116890 KZ |
1042 | if (CONSTANT_P (x)) |
1043 | return true; | |
1044 | ||
1045 | if (GET_CODE (x) == REG) | |
6fb5fa3c | 1046 | { |
6fb5fa3c DB |
1047 | /* Note that we have to test for the actual rtx used for the frame |
1048 | and arg pointers and not just the register number in case we have | |
1049 | eliminated the frame and/or arg pointer and are using it | |
1050 | for pseudos. */ | |
1051 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx | |
1052 | /* The arg pointer varies if it is not a fixed register. */ | |
1053 | || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
1054 | || x == pic_offset_table_rtx) | |
1055 | return true; | |
1056 | return false; | |
6fb5fa3c | 1057 | } |
da6603c6 | 1058 | |
d8116890 | 1059 | return false; |
6fb5fa3c DB |
1060 | } |
1061 | ||
b8698a0f L |
1062 | /* Take all reasonable action to put the address of MEM into the form |
1063 | that we can do analysis on. | |
6fb5fa3c DB |
1064 | |
1065 | The gold standard is to get the address into the form: address + | |
1066 | OFFSET where address is something that rtx_varies_p considers a | |
1067 | constant. When we can get the address in this form, we can do | |
1068 | global analysis on it. Note that for constant bases, address is | |
1069 | not actually returned, only the group_id. The address can be | |
1070 | obtained from that. | |
1071 | ||
1072 | If that fails, we try cselib to get a value we can at least use | |
b8698a0f L |
1073 | locally. If that fails we return false. |
1074 | ||
6fb5fa3c DB |
1075 | The GROUP_ID is set to -1 for cselib bases and the index of the |
1076 | group for non_varying bases. | |
1077 | ||
1078 | FOR_READ is true if this is a mem read and false if not. */ | |
1079 | ||
1080 | static bool | |
1081 | canon_address (rtx mem, | |
6fb5fa3c | 1082 | int *group_id, |
b8698a0f | 1083 | HOST_WIDE_INT *offset, |
6fb5fa3c DB |
1084 | cselib_val **base) |
1085 | { | |
ef4bddc2 | 1086 | machine_mode address_mode = get_address_mode (mem); |
6fb5fa3c DB |
1087 | rtx mem_address = XEXP (mem, 0); |
1088 | rtx expanded_address, address; | |
403c7520 JJ |
1089 | int expanded; |
1090 | ||
4deef538 | 1091 | cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem)); |
6fb5fa3c | 1092 | |
456610d3 | 1093 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1094 | { |
1095 | fprintf (dump_file, " mem: "); | |
1096 | print_inline_rtx (dump_file, mem_address, 0); | |
1097 | fprintf (dump_file, "\n"); | |
1098 | } | |
1099 | ||
403c7520 JJ |
1100 | /* First see if just canon_rtx (mem_address) is const or frame, |
1101 | if not, try cselib_expand_value_rtx and call canon_rtx on that. */ | |
1102 | address = NULL_RTX; | |
1103 | for (expanded = 0; expanded < 2; expanded++) | |
1104 | { | |
1105 | if (expanded) | |
1106 | { | |
1107 | /* Use cselib to replace all of the reg references with the full | |
b8698a0f | 1108 | expression. This will take care of the case where we have |
6fb5fa3c | 1109 | |
403c7520 JJ |
1110 | r_x = base + offset; |
1111 | val = *r_x; | |
b8698a0f L |
1112 | |
1113 | by making it into | |
6fb5fa3c | 1114 | |
403c7520 | 1115 | val = *(base + offset); */ |
6fb5fa3c | 1116 | |
403c7520 JJ |
1117 | expanded_address = cselib_expand_value_rtx (mem_address, |
1118 | scratch, 5); | |
6fb5fa3c | 1119 | |
403c7520 JJ |
1120 | /* If this fails, just go with the address from first |
1121 | iteration. */ | |
1122 | if (!expanded_address) | |
1123 | break; | |
1124 | } | |
1125 | else | |
1126 | expanded_address = mem_address; | |
6fb5fa3c | 1127 | |
403c7520 JJ |
1128 | /* Split the address into canonical BASE + OFFSET terms. */ |
1129 | address = canon_rtx (expanded_address); | |
6fb5fa3c | 1130 | |
403c7520 | 1131 | *offset = 0; |
6fb5fa3c | 1132 | |
456610d3 | 1133 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1134 | { |
1135 | if (expanded) | |
1136 | { | |
1137 | fprintf (dump_file, "\n after cselib_expand address: "); | |
1138 | print_inline_rtx (dump_file, expanded_address, 0); | |
1139 | fprintf (dump_file, "\n"); | |
1140 | } | |
6fb5fa3c | 1141 | |
403c7520 JJ |
1142 | fprintf (dump_file, "\n after canon_rtx address: "); |
1143 | print_inline_rtx (dump_file, address, 0); | |
1144 | fprintf (dump_file, "\n"); | |
1145 | } | |
6fb5fa3c | 1146 | |
403c7520 JJ |
1147 | if (GET_CODE (address) == CONST) |
1148 | address = XEXP (address, 0); | |
6fb5fa3c | 1149 | |
403c7520 JJ |
1150 | if (GET_CODE (address) == PLUS |
1151 | && CONST_INT_P (XEXP (address, 1))) | |
1152 | { | |
1153 | *offset = INTVAL (XEXP (address, 1)); | |
1154 | address = XEXP (address, 0); | |
1155 | } | |
6fb5fa3c | 1156 | |
09e881c9 BE |
1157 | if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem)) |
1158 | && const_or_frame_p (address)) | |
6fb5fa3c | 1159 | { |
fd6daec9 | 1160 | group_info *group = get_group_info (address); |
403c7520 | 1161 | |
456610d3 | 1162 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1163 | fprintf (dump_file, " gid=%d offset=%d \n", |
1164 | group->id, (int)*offset); | |
1165 | *base = NULL; | |
1166 | *group_id = group->id; | |
1167 | return true; | |
6fb5fa3c | 1168 | } |
403c7520 JJ |
1169 | } |
1170 | ||
4deef538 | 1171 | *base = cselib_lookup (address, address_mode, true, GET_MODE (mem)); |
403c7520 JJ |
1172 | *group_id = -1; |
1173 | ||
1174 | if (*base == NULL) | |
1175 | { | |
456610d3 | 1176 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1177 | fprintf (dump_file, " no cselib val - should be a wild read.\n"); |
1178 | return false; | |
6fb5fa3c | 1179 | } |
456610d3 | 1180 | if (dump_file && (dump_flags & TDF_DETAILS)) |
5440c0e7 AO |
1181 | fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n", |
1182 | (*base)->uid, (*base)->hash, (int)*offset); | |
6fb5fa3c DB |
1183 | return true; |
1184 | } | |
1185 | ||
1186 | ||
1187 | /* Clear the rhs field from the active_local_stores array. */ | |
1188 | ||
1189 | static void | |
1190 | clear_rhs_from_active_local_stores (void) | |
1191 | { | |
1192 | insn_info_t ptr = active_local_stores; | |
1193 | ||
1194 | while (ptr) | |
1195 | { | |
fd6daec9 | 1196 | store_info *store_info = ptr->store_rec; |
6fb5fa3c DB |
1197 | /* Skip the clobbers. */ |
1198 | while (!store_info->is_set) | |
1199 | store_info = store_info->next; | |
1200 | ||
1201 | store_info->rhs = NULL; | |
8dd5516b | 1202 | store_info->const_rhs = NULL; |
6fb5fa3c DB |
1203 | |
1204 | ptr = ptr->next_local_store; | |
1205 | } | |
1206 | } | |
1207 | ||
1208 | ||
8dd5516b JJ |
1209 | /* Mark byte POS bytes from the beginning of store S_INFO as unneeded. */ |
1210 | ||
1211 | static inline void | |
fd6daec9 | 1212 | set_position_unneeded (store_info *s_info, int pos) |
8dd5516b JJ |
1213 | { |
1214 | if (__builtin_expect (s_info->is_large, false)) | |
1215 | { | |
fcaa4ca4 NF |
1216 | if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos)) |
1217 | s_info->positions_needed.large.count++; | |
8dd5516b JJ |
1218 | } |
1219 | else | |
1220 | s_info->positions_needed.small_bitmask | |
fecfbfa4 | 1221 | &= ~(HOST_WIDE_INT_1U << pos); |
8dd5516b JJ |
1222 | } |
1223 | ||
1224 | /* Mark the whole store S_INFO as unneeded. */ | |
1225 | ||
1226 | static inline void | |
fd6daec9 | 1227 | set_all_positions_unneeded (store_info *s_info) |
8dd5516b JJ |
1228 | { |
1229 | if (__builtin_expect (s_info->is_large, false)) | |
1230 | { | |
71d6a386 RS |
1231 | bitmap_set_range (s_info->positions_needed.large.bmap, |
1232 | 0, s_info->width); | |
1233 | s_info->positions_needed.large.count = s_info->width; | |
8dd5516b JJ |
1234 | } |
1235 | else | |
07e96250 | 1236 | s_info->positions_needed.small_bitmask = HOST_WIDE_INT_0U; |
8dd5516b JJ |
1237 | } |
1238 | ||
1239 | /* Return TRUE if any bytes from S_INFO store are needed. */ | |
1240 | ||
1241 | static inline bool | |
fd6daec9 | 1242 | any_positions_needed_p (store_info *s_info) |
8dd5516b JJ |
1243 | { |
1244 | if (__builtin_expect (s_info->is_large, false)) | |
71d6a386 | 1245 | return s_info->positions_needed.large.count < s_info->width; |
8dd5516b | 1246 | else |
07e96250 | 1247 | return (s_info->positions_needed.small_bitmask != HOST_WIDE_INT_0U); |
8dd5516b JJ |
1248 | } |
1249 | ||
1250 | /* Return TRUE if all bytes START through START+WIDTH-1 from S_INFO | |
1251 | store are needed. */ | |
1252 | ||
1253 | static inline bool | |
fd6daec9 | 1254 | all_positions_needed_p (store_info *s_info, int start, int width) |
8dd5516b JJ |
1255 | { |
1256 | if (__builtin_expect (s_info->is_large, false)) | |
1257 | { | |
1258 | int end = start + width; | |
1259 | while (start < end) | |
dc491a25 | 1260 | if (bitmap_bit_p (s_info->positions_needed.large.bmap, start++)) |
8dd5516b JJ |
1261 | return false; |
1262 | return true; | |
1263 | } | |
1264 | else | |
1265 | { | |
1266 | unsigned HOST_WIDE_INT mask = lowpart_bitmask (width) << start; | |
1267 | return (s_info->positions_needed.small_bitmask & mask) == mask; | |
1268 | } | |
1269 | } | |
1270 | ||
1271 | ||
fd6daec9 | 1272 | static rtx get_stored_val (store_info *, machine_mode, HOST_WIDE_INT, |
8dd5516b JJ |
1273 | HOST_WIDE_INT, basic_block, bool); |
1274 | ||
1275 | ||
6fb5fa3c DB |
1276 | /* BODY is an instruction pattern that belongs to INSN. Return 1 if |
1277 | there is a candidate store, after adding it to the appropriate | |
1278 | local store group if so. */ | |
1279 | ||
1280 | static int | |
1281 | record_store (rtx body, bb_info_t bb_info) | |
1282 | { | |
6216f94e | 1283 | rtx mem, rhs, const_rhs, mem_addr; |
6fb5fa3c DB |
1284 | HOST_WIDE_INT offset = 0; |
1285 | HOST_WIDE_INT width = 0; | |
6fb5fa3c | 1286 | insn_info_t insn_info = bb_info->last_insn; |
fd6daec9 | 1287 | store_info *store_info = NULL; |
6fb5fa3c DB |
1288 | int group_id; |
1289 | cselib_val *base = NULL; | |
8dd5516b | 1290 | insn_info_t ptr, last, redundant_reason; |
6fb5fa3c DB |
1291 | bool store_is_unused; |
1292 | ||
1293 | if (GET_CODE (body) != SET && GET_CODE (body) != CLOBBER) | |
1294 | return 0; | |
1295 | ||
8dd5516b JJ |
1296 | mem = SET_DEST (body); |
1297 | ||
6fb5fa3c DB |
1298 | /* If this is not used, then this cannot be used to keep the insn |
1299 | from being deleted. On the other hand, it does provide something | |
1300 | that can be used to prove that another store is dead. */ | |
1301 | store_is_unused | |
8dd5516b | 1302 | = (find_reg_note (insn_info->insn, REG_UNUSED, mem) != NULL); |
6fb5fa3c DB |
1303 | |
1304 | /* Check whether that value is a suitable memory location. */ | |
6fb5fa3c DB |
1305 | if (!MEM_P (mem)) |
1306 | { | |
1307 | /* If the set or clobber is unused, then it does not effect our | |
1308 | ability to get rid of the entire insn. */ | |
1309 | if (!store_is_unused) | |
1310 | insn_info->cannot_delete = true; | |
1311 | return 0; | |
1312 | } | |
1313 | ||
1314 | /* At this point we know mem is a mem. */ | |
1315 | if (GET_MODE (mem) == BLKmode) | |
1316 | { | |
1317 | if (GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
1318 | { | |
456610d3 | 1319 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1320 | fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n"); |
1321 | add_wild_read (bb_info); | |
1322 | insn_info->cannot_delete = true; | |
8dd5516b | 1323 | return 0; |
6fb5fa3c | 1324 | } |
8dd5516b JJ |
1325 | /* Handle (set (mem:BLK (addr) [... S36 ...]) (const_int 0)) |
1326 | as memset (addr, 0, 36); */ | |
f5541398 RS |
1327 | else if (!MEM_SIZE_KNOWN_P (mem) |
1328 | || MEM_SIZE (mem) <= 0 | |
1329 | || MEM_SIZE (mem) > MAX_OFFSET | |
8dd5516b | 1330 | || GET_CODE (body) != SET |
8dd5516b | 1331 | || !CONST_INT_P (SET_SRC (body))) |
6fb5fa3c | 1332 | { |
8dd5516b JJ |
1333 | if (!store_is_unused) |
1334 | { | |
1335 | /* If the set or clobber is unused, then it does not effect our | |
1336 | ability to get rid of the entire insn. */ | |
1337 | insn_info->cannot_delete = true; | |
1338 | clear_rhs_from_active_local_stores (); | |
1339 | } | |
1340 | return 0; | |
6fb5fa3c | 1341 | } |
6fb5fa3c DB |
1342 | } |
1343 | ||
1344 | /* We can still process a volatile mem, we just cannot delete it. */ | |
1345 | if (MEM_VOLATILE_P (mem)) | |
8dd5516b | 1346 | insn_info->cannot_delete = true; |
6fb5fa3c | 1347 | |
ac6929b5 | 1348 | if (!canon_address (mem, &group_id, &offset, &base)) |
6fb5fa3c DB |
1349 | { |
1350 | clear_rhs_from_active_local_stores (); | |
1351 | return 0; | |
1352 | } | |
1353 | ||
8dd5516b | 1354 | if (GET_MODE (mem) == BLKmode) |
f5541398 | 1355 | width = MEM_SIZE (mem); |
8dd5516b | 1356 | else |
6f557e0e | 1357 | width = GET_MODE_SIZE (GET_MODE (mem)); |
6fb5fa3c | 1358 | |
213ffde2 JJ |
1359 | if (offset > HOST_WIDE_INT_MAX - width) |
1360 | { | |
1361 | clear_rhs_from_active_local_stores (); | |
1362 | return 0; | |
1363 | } | |
1364 | ||
ac6929b5 | 1365 | if (group_id >= 0) |
6fb5fa3c DB |
1366 | { |
1367 | /* In the restrictive case where the base is a constant or the | |
1368 | frame pointer we can do global analysis. */ | |
b8698a0f | 1369 | |
fd6daec9 | 1370 | group_info *group |
9771b263 | 1371 | = rtx_group_vec[group_id]; |
d26c7090 | 1372 | tree expr = MEM_EXPR (mem); |
b8698a0f | 1373 | |
da6603c6 | 1374 | store_info = rtx_store_info_pool.allocate (); |
d26c7090 | 1375 | set_usage_bits (group, offset, width, expr); |
6fb5fa3c | 1376 | |
456610d3 | 1377 | if (dump_file && (dump_flags & TDF_DETAILS)) |
71d6a386 RS |
1378 | { |
1379 | fprintf (dump_file, " processing const base store gid=%d", | |
1380 | group_id); | |
1381 | print_range (dump_file, offset, width); | |
1382 | fprintf (dump_file, "\n"); | |
1383 | } | |
6fb5fa3c DB |
1384 | } |
1385 | else | |
1386 | { | |
9e412ca3 | 1387 | if (may_be_sp_based_p (XEXP (mem, 0))) |
50f0f366 | 1388 | insn_info->stack_pointer_based = true; |
6fb5fa3c | 1389 | insn_info->contains_cselib_groups = true; |
50f0f366 | 1390 | |
da6603c6 | 1391 | store_info = cse_store_info_pool.allocate (); |
6fb5fa3c DB |
1392 | group_id = -1; |
1393 | ||
456610d3 | 1394 | if (dump_file && (dump_flags & TDF_DETAILS)) |
71d6a386 RS |
1395 | { |
1396 | fprintf (dump_file, " processing cselib store "); | |
1397 | print_range (dump_file, offset, width); | |
1398 | fprintf (dump_file, "\n"); | |
1399 | } | |
6fb5fa3c DB |
1400 | } |
1401 | ||
8dd5516b JJ |
1402 | const_rhs = rhs = NULL_RTX; |
1403 | if (GET_CODE (body) == SET | |
1404 | /* No place to keep the value after ra. */ | |
1405 | && !reload_completed | |
1406 | && (REG_P (SET_SRC (body)) | |
1407 | || GET_CODE (SET_SRC (body)) == SUBREG | |
1408 | || CONSTANT_P (SET_SRC (body))) | |
1409 | && !MEM_VOLATILE_P (mem) | |
1410 | /* Sometimes the store and reload is used for truncation and | |
1411 | rounding. */ | |
1412 | && !(FLOAT_MODE_P (GET_MODE (mem)) && (flag_float_store))) | |
1413 | { | |
1414 | rhs = SET_SRC (body); | |
1415 | if (CONSTANT_P (rhs)) | |
1416 | const_rhs = rhs; | |
1417 | else if (body == PATTERN (insn_info->insn)) | |
1418 | { | |
1419 | rtx tem = find_reg_note (insn_info->insn, REG_EQUAL, NULL_RTX); | |
1420 | if (tem && CONSTANT_P (XEXP (tem, 0))) | |
1421 | const_rhs = XEXP (tem, 0); | |
1422 | } | |
1423 | if (const_rhs == NULL_RTX && REG_P (rhs)) | |
1424 | { | |
1425 | rtx tem = cselib_expand_value_rtx (rhs, scratch, 5); | |
1426 | ||
1427 | if (tem && CONSTANT_P (tem)) | |
1428 | const_rhs = tem; | |
1429 | } | |
1430 | } | |
1431 | ||
6fb5fa3c DB |
1432 | /* Check to see if this stores causes some other stores to be |
1433 | dead. */ | |
1434 | ptr = active_local_stores; | |
1435 | last = NULL; | |
8dd5516b | 1436 | redundant_reason = NULL; |
6216f94e | 1437 | mem = canon_rtx (mem); |
ac6929b5 RB |
1438 | |
1439 | if (group_id < 0) | |
1440 | mem_addr = base->val_rtx; | |
6216f94e JJ |
1441 | else |
1442 | { | |
ac6929b5 RB |
1443 | group_info *group = rtx_group_vec[group_id]; |
1444 | mem_addr = group->canon_base_addr; | |
6216f94e | 1445 | } |
ac6929b5 RB |
1446 | if (offset) |
1447 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); | |
6fb5fa3c DB |
1448 | |
1449 | while (ptr) | |
1450 | { | |
1451 | insn_info_t next = ptr->next_local_store; | |
fd6daec9 | 1452 | struct store_info *s_info = ptr->store_rec; |
60564289 | 1453 | bool del = true; |
6fb5fa3c DB |
1454 | |
1455 | /* Skip the clobbers. We delete the active insn if this insn | |
6ed3da00 | 1456 | shadows the set. To have been put on the active list, it |
6fb5fa3c DB |
1457 | has exactly on set. */ |
1458 | while (!s_info->is_set) | |
1459 | s_info = s_info->next; | |
1460 | ||
ac6929b5 | 1461 | if (s_info->group_id == group_id && s_info->cse_base == base) |
6fb5fa3c DB |
1462 | { |
1463 | HOST_WIDE_INT i; | |
456610d3 | 1464 | if (dump_file && (dump_flags & TDF_DETAILS)) |
71d6a386 RS |
1465 | { |
1466 | fprintf (dump_file, " trying store in insn=%d gid=%d", | |
1467 | INSN_UID (ptr->insn), s_info->group_id); | |
1468 | print_range (dump_file, s_info->offset, s_info->width); | |
1469 | fprintf (dump_file, "\n"); | |
1470 | } | |
8dd5516b JJ |
1471 | |
1472 | /* Even if PTR won't be eliminated as unneeded, if both | |
1473 | PTR and this insn store the same constant value, we might | |
1474 | eliminate this insn instead. */ | |
1475 | if (s_info->const_rhs | |
1476 | && const_rhs | |
71d6a386 RS |
1477 | && known_subrange_p (offset, width, |
1478 | s_info->offset, s_info->width) | |
1479 | && all_positions_needed_p (s_info, offset - s_info->offset, | |
8dd5516b JJ |
1480 | width)) |
1481 | { | |
1482 | if (GET_MODE (mem) == BLKmode) | |
1483 | { | |
1484 | if (GET_MODE (s_info->mem) == BLKmode | |
1485 | && s_info->const_rhs == const_rhs) | |
1486 | redundant_reason = ptr; | |
1487 | } | |
1488 | else if (s_info->const_rhs == const0_rtx | |
1489 | && const_rhs == const0_rtx) | |
1490 | redundant_reason = ptr; | |
1491 | else | |
1492 | { | |
1493 | rtx val; | |
1494 | start_sequence (); | |
71d6a386 | 1495 | val = get_stored_val (s_info, GET_MODE (mem), offset, width, |
8dd5516b JJ |
1496 | BLOCK_FOR_INSN (insn_info->insn), |
1497 | true); | |
1498 | if (get_insns () != NULL) | |
1499 | val = NULL_RTX; | |
1500 | end_sequence (); | |
1501 | if (val && rtx_equal_p (val, const_rhs)) | |
1502 | redundant_reason = ptr; | |
1503 | } | |
1504 | } | |
1505 | ||
71d6a386 RS |
1506 | if (known_subrange_p (s_info->offset, s_info->width, offset, width)) |
1507 | /* The new store touches every byte that S_INFO does. */ | |
1508 | set_all_positions_unneeded (s_info); | |
1509 | else | |
1510 | { | |
1511 | HOST_WIDE_INT begin_unneeded = offset - s_info->offset; | |
1512 | HOST_WIDE_INT end_unneeded = begin_unneeded + width; | |
1513 | begin_unneeded = MAX (begin_unneeded, 0); | |
1514 | end_unneeded = MIN (end_unneeded, s_info->width); | |
1515 | for (i = begin_unneeded; i < end_unneeded; ++i) | |
1516 | set_position_unneeded (s_info, i); | |
1517 | } | |
6fb5fa3c DB |
1518 | } |
1519 | else if (s_info->rhs) | |
1520 | /* Need to see if it is possible for this store to overwrite | |
1521 | the value of store_info. If it is, set the rhs to NULL to | |
1522 | keep it from being used to remove a load. */ | |
1523 | { | |
43b9f499 RB |
1524 | if (canon_output_dependence (s_info->mem, true, |
1525 | mem, GET_MODE (mem), | |
1526 | mem_addr)) | |
8dd5516b JJ |
1527 | { |
1528 | s_info->rhs = NULL; | |
1529 | s_info->const_rhs = NULL; | |
1530 | } | |
6fb5fa3c | 1531 | } |
6216f94e | 1532 | |
6fb5fa3c DB |
1533 | /* An insn can be deleted if every position of every one of |
1534 | its s_infos is zero. */ | |
1b6fa860 | 1535 | if (any_positions_needed_p (s_info)) |
60564289 | 1536 | del = false; |
8dd5516b | 1537 | |
60564289 | 1538 | if (del) |
6fb5fa3c DB |
1539 | { |
1540 | insn_info_t insn_to_delete = ptr; | |
b8698a0f | 1541 | |
dabd47e7 | 1542 | active_local_stores_len--; |
6fb5fa3c DB |
1543 | if (last) |
1544 | last->next_local_store = ptr->next_local_store; | |
1545 | else | |
1546 | active_local_stores = ptr->next_local_store; | |
b8698a0f | 1547 | |
1b6fa860 JJ |
1548 | if (!insn_to_delete->cannot_delete) |
1549 | delete_dead_store_insn (insn_to_delete); | |
6fb5fa3c DB |
1550 | } |
1551 | else | |
1552 | last = ptr; | |
b8698a0f | 1553 | |
6fb5fa3c DB |
1554 | ptr = next; |
1555 | } | |
b8698a0f | 1556 | |
6fb5fa3c DB |
1557 | /* Finish filling in the store_info. */ |
1558 | store_info->next = insn_info->store_rec; | |
1559 | insn_info->store_rec = store_info; | |
6216f94e | 1560 | store_info->mem = mem; |
6216f94e | 1561 | store_info->mem_addr = mem_addr; |
6fb5fa3c | 1562 | store_info->cse_base = base; |
8dd5516b JJ |
1563 | if (width > HOST_BITS_PER_WIDE_INT) |
1564 | { | |
1565 | store_info->is_large = true; | |
1566 | store_info->positions_needed.large.count = 0; | |
3f9b14ff | 1567 | store_info->positions_needed.large.bmap = BITMAP_ALLOC (&dse_bitmap_obstack); |
8dd5516b JJ |
1568 | } |
1569 | else | |
1570 | { | |
1571 | store_info->is_large = false; | |
1572 | store_info->positions_needed.small_bitmask = lowpart_bitmask (width); | |
1573 | } | |
6fb5fa3c | 1574 | store_info->group_id = group_id; |
71d6a386 RS |
1575 | store_info->offset = offset; |
1576 | store_info->width = width; | |
6fb5fa3c | 1577 | store_info->is_set = GET_CODE (body) == SET; |
8dd5516b JJ |
1578 | store_info->rhs = rhs; |
1579 | store_info->const_rhs = const_rhs; | |
1580 | store_info->redundant_reason = redundant_reason; | |
6fb5fa3c | 1581 | |
6fb5fa3c DB |
1582 | /* If this is a clobber, we return 0. We will only be able to |
1583 | delete this insn if there is only one store USED store, but we | |
1584 | can use the clobber to delete other stores earlier. */ | |
1585 | return store_info->is_set ? 1 : 0; | |
1586 | } | |
1587 | ||
1588 | ||
1589 | static void | |
1590 | dump_insn_info (const char * start, insn_info_t insn_info) | |
1591 | { | |
b8698a0f | 1592 | fprintf (dump_file, "%s insn=%d %s\n", start, |
6fb5fa3c DB |
1593 | INSN_UID (insn_info->insn), |
1594 | insn_info->store_rec ? "has store" : "naked"); | |
1595 | } | |
1596 | ||
1597 | ||
8660aaae EC |
1598 | /* If the modes are different and the value's source and target do not |
1599 | line up, we need to extract the value from lower part of the rhs of | |
1600 | the store, shift it, and then put it into a form that can be shoved | |
1601 | into the read_insn. This function generates a right SHIFT of a | |
1602 | value that is at least ACCESS_SIZE bytes wide of READ_MODE. The | |
1603 | shift sequence is returned or NULL if we failed to find a | |
1604 | shift. */ | |
1605 | ||
1606 | static rtx | |
18b526e8 | 1607 | find_shift_sequence (int access_size, |
fd6daec9 | 1608 | store_info *store_info, |
ef4bddc2 | 1609 | machine_mode read_mode, |
8dd5516b | 1610 | int shift, bool speed, bool require_cst) |
8660aaae | 1611 | { |
ef4bddc2 | 1612 | machine_mode store_mode = GET_MODE (store_info->mem); |
f67f4dff | 1613 | scalar_int_mode new_mode; |
18b526e8 | 1614 | rtx read_reg = NULL; |
8660aaae EC |
1615 | |
1616 | /* Some machines like the x86 have shift insns for each size of | |
1617 | operand. Other machines like the ppc or the ia-64 may only have | |
1618 | shift insns that shift values within 32 or 64 bit registers. | |
1619 | This loop tries to find the smallest shift insn that will right | |
1620 | justify the value we want to read but is available in one insn on | |
1621 | the machine. */ | |
1622 | ||
f67f4dff RS |
1623 | opt_scalar_int_mode new_mode_iter; |
1624 | FOR_EACH_MODE_FROM (new_mode_iter, | |
1625 | smallest_int_mode_for_size (access_size * BITS_PER_UNIT)) | |
8660aaae | 1626 | { |
dc01c3d1 DM |
1627 | rtx target, new_reg, new_lhs; |
1628 | rtx_insn *shift_seq, *insn; | |
d898d29b | 1629 | int cost; |
348eea5f | 1630 | |
f67f4dff | 1631 | new_mode = new_mode_iter.require (); |
c94843d2 RS |
1632 | if (GET_MODE_BITSIZE (new_mode) > BITS_PER_WORD) |
1633 | break; | |
1634 | ||
72a2609f JJ |
1635 | /* If a constant was stored into memory, try to simplify it here, |
1636 | otherwise the cost of the shift might preclude this optimization | |
1637 | e.g. at -Os, even when no actual shift will be needed. */ | |
8dd5516b | 1638 | if (store_info->const_rhs) |
72a2609f JJ |
1639 | { |
1640 | unsigned int byte = subreg_lowpart_offset (new_mode, store_mode); | |
8dd5516b JJ |
1641 | rtx ret = simplify_subreg (new_mode, store_info->const_rhs, |
1642 | store_mode, byte); | |
72a2609f JJ |
1643 | if (ret && CONSTANT_P (ret)) |
1644 | { | |
1645 | ret = simplify_const_binary_operation (LSHIFTRT, new_mode, | |
b4ddce36 | 1646 | ret, GEN_INT (shift)); |
72a2609f JJ |
1647 | if (ret && CONSTANT_P (ret)) |
1648 | { | |
1649 | byte = subreg_lowpart_offset (read_mode, new_mode); | |
1650 | ret = simplify_subreg (read_mode, ret, new_mode, byte); | |
1651 | if (ret && CONSTANT_P (ret) | |
e548c9df AM |
1652 | && (set_src_cost (ret, read_mode, speed) |
1653 | <= COSTS_N_INSNS (1))) | |
72a2609f JJ |
1654 | return ret; |
1655 | } | |
1656 | } | |
1657 | } | |
1658 | ||
8dd5516b JJ |
1659 | if (require_cst) |
1660 | return NULL_RTX; | |
1661 | ||
18b526e8 RS |
1662 | /* Try a wider mode if truncating the store mode to NEW_MODE |
1663 | requires a real instruction. */ | |
1664 | if (GET_MODE_BITSIZE (new_mode) < GET_MODE_BITSIZE (store_mode) | |
d0edd768 | 1665 | && !TRULY_NOOP_TRUNCATION_MODES_P (new_mode, store_mode)) |
348eea5f RS |
1666 | continue; |
1667 | ||
18b526e8 RS |
1668 | /* Also try a wider mode if the necessary punning is either not |
1669 | desirable or not possible. */ | |
1670 | if (!CONSTANT_P (store_info->rhs) | |
99e1629f | 1671 | && !targetm.modes_tieable_p (new_mode, store_mode)) |
18b526e8 | 1672 | continue; |
18b526e8 | 1673 | |
348eea5f | 1674 | new_reg = gen_reg_rtx (new_mode); |
8660aaae EC |
1675 | |
1676 | start_sequence (); | |
1677 | ||
1678 | /* In theory we could also check for an ashr. Ian Taylor knows | |
1679 | of one dsp where the cost of these two was not the same. But | |
1680 | this really is a rare case anyway. */ | |
1681 | target = expand_binop (new_mode, lshr_optab, new_reg, | |
b4ddce36 | 1682 | GEN_INT (shift), new_reg, 1, OPTAB_DIRECT); |
8660aaae | 1683 | |
c6f3019a RS |
1684 | shift_seq = get_insns (); |
1685 | end_sequence (); | |
8660aaae | 1686 | |
c6f3019a RS |
1687 | if (target != new_reg || shift_seq == NULL) |
1688 | continue; | |
1689 | ||
1690 | cost = 0; | |
1691 | for (insn = shift_seq; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
1692 | if (INSN_P (insn)) | |
d09e78e8 | 1693 | cost += insn_cost (insn, speed); |
c6f3019a RS |
1694 | |
1695 | /* The computation up to here is essentially independent | |
1696 | of the arguments and could be precomputed. It may | |
1697 | not be worth doing so. We could precompute if | |
1698 | worthwhile or at least cache the results. The result | |
06acf7d0 RS |
1699 | technically depends on both SHIFT and ACCESS_SIZE, |
1700 | but in practice the answer will depend only on ACCESS_SIZE. */ | |
c6f3019a RS |
1701 | |
1702 | if (cost > COSTS_N_INSNS (1)) | |
1703 | continue; | |
1704 | ||
d898d29b JJ |
1705 | new_lhs = extract_low_bits (new_mode, store_mode, |
1706 | copy_rtx (store_info->rhs)); | |
1707 | if (new_lhs == NULL_RTX) | |
1708 | continue; | |
1709 | ||
c6f3019a RS |
1710 | /* We found an acceptable shift. Generate a move to |
1711 | take the value from the store and put it into the | |
1712 | shift pseudo, then shift it, then generate another | |
1713 | move to put in into the target of the read. */ | |
18b526e8 | 1714 | emit_move_insn (new_reg, new_lhs); |
c6f3019a | 1715 | emit_insn (shift_seq); |
18b526e8 | 1716 | read_reg = extract_low_bits (read_mode, new_mode, new_reg); |
c6f3019a | 1717 | break; |
8660aaae EC |
1718 | } |
1719 | ||
18b526e8 | 1720 | return read_reg; |
8660aaae EC |
1721 | } |
1722 | ||
1723 | ||
02b47899 KZ |
1724 | /* Call back for note_stores to find the hard regs set or clobbered by |
1725 | insn. Data is a bitmap of the hardregs set so far. */ | |
1726 | ||
1727 | static void | |
1728 | look_for_hardregs (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) | |
1729 | { | |
1730 | bitmap regs_set = (bitmap) data; | |
1731 | ||
1732 | if (REG_P (x) | |
f773c2bd | 1733 | && HARD_REGISTER_P (x)) |
dc8afb70 | 1734 | bitmap_set_range (regs_set, REGNO (x), REG_NREGS (x)); |
02b47899 KZ |
1735 | } |
1736 | ||
8dd5516b | 1737 | /* Helper function for replace_read and record_store. |
71d6a386 RS |
1738 | Attempt to return a value of mode READ_MODE stored in STORE_INFO, |
1739 | consisting of READ_WIDTH bytes starting from READ_OFFSET. Return NULL | |
8dd5516b JJ |
1740 | if not successful. If REQUIRE_CST is true, return always constant. */ |
1741 | ||
1742 | static rtx | |
fd6daec9 | 1743 | get_stored_val (store_info *store_info, machine_mode read_mode, |
71d6a386 | 1744 | HOST_WIDE_INT read_offset, HOST_WIDE_INT read_width, |
8dd5516b JJ |
1745 | basic_block bb, bool require_cst) |
1746 | { | |
ef4bddc2 | 1747 | machine_mode store_mode = GET_MODE (store_info->mem); |
71d6a386 | 1748 | HOST_WIDE_INT gap; |
8dd5516b JJ |
1749 | rtx read_reg; |
1750 | ||
1751 | /* To get here the read is within the boundaries of the write so | |
1752 | shift will never be negative. Start out with the shift being in | |
1753 | bytes. */ | |
1754 | if (store_mode == BLKmode) | |
71d6a386 | 1755 | gap = 0; |
8dd5516b | 1756 | else if (BYTES_BIG_ENDIAN) |
71d6a386 RS |
1757 | gap = ((store_info->offset + store_info->width) |
1758 | - (read_offset + read_width)); | |
8dd5516b | 1759 | else |
71d6a386 | 1760 | gap = read_offset - store_info->offset; |
8dd5516b | 1761 | |
71d6a386 RS |
1762 | if (gap != 0) |
1763 | { | |
1764 | HOST_WIDE_INT shift = gap * BITS_PER_UNIT; | |
1765 | HOST_WIDE_INT access_size = GET_MODE_SIZE (read_mode) + gap; | |
1766 | read_reg = find_shift_sequence (access_size, store_info, read_mode, | |
1767 | shift, optimize_bb_for_speed_p (bb), | |
1768 | require_cst); | |
1769 | } | |
8dd5516b JJ |
1770 | else if (store_mode == BLKmode) |
1771 | { | |
1772 | /* The store is a memset (addr, const_val, const_size). */ | |
1773 | gcc_assert (CONST_INT_P (store_info->rhs)); | |
304b9962 RS |
1774 | scalar_int_mode int_store_mode; |
1775 | if (!int_mode_for_mode (read_mode).exists (&int_store_mode)) | |
8dd5516b JJ |
1776 | read_reg = NULL_RTX; |
1777 | else if (store_info->rhs == const0_rtx) | |
304b9962 RS |
1778 | read_reg = extract_low_bits (read_mode, int_store_mode, const0_rtx); |
1779 | else if (GET_MODE_BITSIZE (int_store_mode) > HOST_BITS_PER_WIDE_INT | |
8dd5516b JJ |
1780 | || BITS_PER_UNIT >= HOST_BITS_PER_WIDE_INT) |
1781 | read_reg = NULL_RTX; | |
1782 | else | |
1783 | { | |
1784 | unsigned HOST_WIDE_INT c | |
1785 | = INTVAL (store_info->rhs) | |
fecfbfa4 | 1786 | & ((HOST_WIDE_INT_1 << BITS_PER_UNIT) - 1); |
8dd5516b JJ |
1787 | int shift = BITS_PER_UNIT; |
1788 | while (shift < HOST_BITS_PER_WIDE_INT) | |
1789 | { | |
1790 | c |= (c << shift); | |
1791 | shift <<= 1; | |
1792 | } | |
304b9962 RS |
1793 | read_reg = gen_int_mode (c, int_store_mode); |
1794 | read_reg = extract_low_bits (read_mode, int_store_mode, read_reg); | |
8dd5516b JJ |
1795 | } |
1796 | } | |
1797 | else if (store_info->const_rhs | |
1798 | && (require_cst | |
1799 | || GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))) | |
1800 | read_reg = extract_low_bits (read_mode, store_mode, | |
1801 | copy_rtx (store_info->const_rhs)); | |
1802 | else | |
1803 | read_reg = extract_low_bits (read_mode, store_mode, | |
1804 | copy_rtx (store_info->rhs)); | |
1805 | if (require_cst && read_reg && !CONSTANT_P (read_reg)) | |
1806 | read_reg = NULL_RTX; | |
1807 | return read_reg; | |
1808 | } | |
02b47899 | 1809 | |
6fb5fa3c DB |
1810 | /* Take a sequence of: |
1811 | A <- r1 | |
1812 | ... | |
1813 | ... <- A | |
1814 | ||
b8698a0f | 1815 | and change it into |
6fb5fa3c DB |
1816 | r2 <- r1 |
1817 | A <- r1 | |
1818 | ... | |
1819 | ... <- r2 | |
1820 | ||
8660aaae EC |
1821 | or |
1822 | ||
1823 | r3 <- extract (r1) | |
1824 | r3 <- r3 >> shift | |
1825 | r2 <- extract (r3) | |
1826 | ... <- r2 | |
1827 | ||
1828 | or | |
1829 | ||
1830 | r2 <- extract (r1) | |
1831 | ... <- r2 | |
1832 | ||
1833 | Depending on the alignment and the mode of the store and | |
1834 | subsequent load. | |
1835 | ||
1836 | ||
1837 | The STORE_INFO and STORE_INSN are for the store and READ_INFO | |
6fb5fa3c DB |
1838 | and READ_INSN are for the read. Return true if the replacement |
1839 | went ok. */ | |
1840 | ||
1841 | static bool | |
fd6daec9 | 1842 | replace_read (store_info *store_info, insn_info_t store_insn, |
8dd5516b JJ |
1843 | read_info_t read_info, insn_info_t read_insn, rtx *loc, |
1844 | bitmap regs_live) | |
6fb5fa3c | 1845 | { |
ef4bddc2 RS |
1846 | machine_mode store_mode = GET_MODE (store_info->mem); |
1847 | machine_mode read_mode = GET_MODE (read_info->mem); | |
dc01c3d1 DM |
1848 | rtx_insn *insns, *this_insn; |
1849 | rtx read_reg; | |
8dd5516b | 1850 | basic_block bb; |
8660aaae | 1851 | |
6fb5fa3c DB |
1852 | if (!dbg_cnt (dse)) |
1853 | return false; | |
1854 | ||
18b526e8 RS |
1855 | /* Create a sequence of instructions to set up the read register. |
1856 | This sequence goes immediately before the store and its result | |
1857 | is read by the load. | |
1858 | ||
1859 | We need to keep this in perspective. We are replacing a read | |
8660aaae EC |
1860 | with a sequence of insns, but the read will almost certainly be |
1861 | in cache, so it is not going to be an expensive one. Thus, we | |
1862 | are not willing to do a multi insn shift or worse a subroutine | |
1863 | call to get rid of the read. */ | |
456610d3 | 1864 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1865 | fprintf (dump_file, "trying to replace %smode load in insn %d" |
1866 | " from %smode store in insn %d\n", | |
1867 | GET_MODE_NAME (read_mode), INSN_UID (read_insn->insn), | |
1868 | GET_MODE_NAME (store_mode), INSN_UID (store_insn->insn)); | |
1869 | start_sequence (); | |
8dd5516b JJ |
1870 | bb = BLOCK_FOR_INSN (read_insn->insn); |
1871 | read_reg = get_stored_val (store_info, | |
71d6a386 | 1872 | read_mode, read_info->offset, read_info->width, |
8dd5516b | 1873 | bb, false); |
18b526e8 | 1874 | if (read_reg == NULL_RTX) |
8660aaae | 1875 | { |
18b526e8 | 1876 | end_sequence (); |
456610d3 | 1877 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1878 | fprintf (dump_file, " -- could not extract bits of stored value\n"); |
1879 | return false; | |
8660aaae | 1880 | } |
18b526e8 RS |
1881 | /* Force the value into a new register so that it won't be clobbered |
1882 | between the store and the load. */ | |
1883 | read_reg = copy_to_mode_reg (read_mode, read_reg); | |
1884 | insns = get_insns (); | |
1885 | end_sequence (); | |
8660aaae | 1886 | |
02b47899 KZ |
1887 | if (insns != NULL_RTX) |
1888 | { | |
1889 | /* Now we have to scan the set of new instructions to see if the | |
1890 | sequence contains and sets of hardregs that happened to be | |
1891 | live at this point. For instance, this can happen if one of | |
1892 | the insns sets the CC and the CC happened to be live at that | |
1893 | point. This does occasionally happen, see PR 37922. */ | |
3f9b14ff | 1894 | bitmap regs_set = BITMAP_ALLOC (®_obstack); |
02b47899 KZ |
1895 | |
1896 | for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn)) | |
1897 | note_stores (PATTERN (this_insn), look_for_hardregs, regs_set); | |
b8698a0f | 1898 | |
02b47899 KZ |
1899 | bitmap_and_into (regs_set, regs_live); |
1900 | if (!bitmap_empty_p (regs_set)) | |
1901 | { | |
456610d3 | 1902 | if (dump_file && (dump_flags & TDF_DETAILS)) |
02b47899 | 1903 | { |
b8698a0f | 1904 | fprintf (dump_file, |
02b47899 KZ |
1905 | "abandoning replacement because sequence clobbers live hardregs:"); |
1906 | df_print_regset (dump_file, regs_set); | |
1907 | } | |
b8698a0f | 1908 | |
02b47899 KZ |
1909 | BITMAP_FREE (regs_set); |
1910 | return false; | |
1911 | } | |
1912 | BITMAP_FREE (regs_set); | |
1913 | } | |
1914 | ||
8660aaae | 1915 | if (validate_change (read_insn->insn, loc, read_reg, 0)) |
6fb5fa3c | 1916 | { |
fd6daec9 | 1917 | deferred_change *change = deferred_change_pool.allocate (); |
b8698a0f | 1918 | |
8660aaae EC |
1919 | /* Insert this right before the store insn where it will be safe |
1920 | from later insns that might change it before the read. */ | |
1921 | emit_insn_before (insns, store_insn->insn); | |
b8698a0f | 1922 | |
8660aaae EC |
1923 | /* And now for the kludge part: cselib croaks if you just |
1924 | return at this point. There are two reasons for this: | |
b8698a0f | 1925 | |
8660aaae EC |
1926 | 1) Cselib has an idea of how many pseudos there are and |
1927 | that does not include the new ones we just added. | |
b8698a0f | 1928 | |
8660aaae EC |
1929 | 2) Cselib does not know about the move insn we added |
1930 | above the store_info, and there is no way to tell it | |
1931 | about it, because it has "moved on". | |
b8698a0f | 1932 | |
8660aaae EC |
1933 | Problem (1) is fixable with a certain amount of engineering. |
1934 | Problem (2) is requires starting the bb from scratch. This | |
1935 | could be expensive. | |
b8698a0f | 1936 | |
8660aaae EC |
1937 | So we are just going to have to lie. The move/extraction |
1938 | insns are not really an issue, cselib did not see them. But | |
1939 | the use of the new pseudo read_insn is a real problem because | |
1940 | cselib has not scanned this insn. The way that we solve this | |
1941 | problem is that we are just going to put the mem back for now | |
1942 | and when we are finished with the block, we undo this. We | |
1943 | keep a table of mems to get rid of. At the end of the basic | |
1944 | block we can put them back. */ | |
b8698a0f | 1945 | |
8660aaae | 1946 | *loc = read_info->mem; |
da6603c6 ML |
1947 | change->next = deferred_change_list; |
1948 | deferred_change_list = change; | |
1949 | change->loc = loc; | |
1950 | change->reg = read_reg; | |
b8698a0f | 1951 | |
8660aaae EC |
1952 | /* Get rid of the read_info, from the point of view of the |
1953 | rest of dse, play like this read never happened. */ | |
1954 | read_insn->read_rec = read_info->next; | |
fb0b2914 | 1955 | read_info_type_pool.remove (read_info); |
456610d3 | 1956 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1957 | { |
1958 | fprintf (dump_file, " -- replaced the loaded MEM with "); | |
1959 | print_simple_rtl (dump_file, read_reg); | |
1960 | fprintf (dump_file, "\n"); | |
1961 | } | |
8660aaae | 1962 | return true; |
6fb5fa3c | 1963 | } |
b8698a0f | 1964 | else |
6fb5fa3c | 1965 | { |
456610d3 | 1966 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1967 | { |
1968 | fprintf (dump_file, " -- replacing the loaded MEM with "); | |
1969 | print_simple_rtl (dump_file, read_reg); | |
1970 | fprintf (dump_file, " led to an invalid instruction\n"); | |
1971 | } | |
6fb5fa3c DB |
1972 | return false; |
1973 | } | |
1974 | } | |
1975 | ||
d7111da8 RS |
1976 | /* Check the address of MEM *LOC and kill any appropriate stores that may |
1977 | be active. */ | |
6fb5fa3c | 1978 | |
d7111da8 RS |
1979 | static void |
1980 | check_mem_read_rtx (rtx *loc, bb_info_t bb_info) | |
6fb5fa3c | 1981 | { |
6216f94e | 1982 | rtx mem = *loc, mem_addr; |
6fb5fa3c DB |
1983 | insn_info_t insn_info; |
1984 | HOST_WIDE_INT offset = 0; | |
1985 | HOST_WIDE_INT width = 0; | |
b8698a0f | 1986 | cselib_val *base = NULL; |
6fb5fa3c DB |
1987 | int group_id; |
1988 | read_info_t read_info; | |
1989 | ||
6fb5fa3c DB |
1990 | insn_info = bb_info->last_insn; |
1991 | ||
1992 | if ((MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
1993 | || (MEM_VOLATILE_P (mem))) | |
1994 | { | |
456610d3 | 1995 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1996 | fprintf (dump_file, " adding wild read, volatile or barrier.\n"); |
1997 | add_wild_read (bb_info); | |
1998 | insn_info->cannot_delete = true; | |
d7111da8 | 1999 | return; |
6fb5fa3c DB |
2000 | } |
2001 | ||
2002 | /* If it is reading readonly mem, then there can be no conflict with | |
2003 | another write. */ | |
2004 | if (MEM_READONLY_P (mem)) | |
d7111da8 | 2005 | return; |
6fb5fa3c | 2006 | |
ac6929b5 | 2007 | if (!canon_address (mem, &group_id, &offset, &base)) |
6fb5fa3c | 2008 | { |
456610d3 | 2009 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2010 | fprintf (dump_file, " adding wild read, canon_address failure.\n"); |
2011 | add_wild_read (bb_info); | |
d7111da8 | 2012 | return; |
6fb5fa3c DB |
2013 | } |
2014 | ||
2015 | if (GET_MODE (mem) == BLKmode) | |
2016 | width = -1; | |
2017 | else | |
2018 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
2019 | ||
213ffde2 JJ |
2020 | if (width == -1 |
2021 | ? offset == HOST_WIDE_INT_MIN | |
2022 | : offset > HOST_WIDE_INT_MAX - width) | |
938f9248 | 2023 | { |
213ffde2 JJ |
2024 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2025 | fprintf (dump_file, " adding wild read, due to overflow.\n"); | |
2026 | add_wild_read (bb_info); | |
938f9248 ML |
2027 | return; |
2028 | } | |
2029 | ||
fb0b2914 | 2030 | read_info = read_info_type_pool.allocate (); |
6fb5fa3c DB |
2031 | read_info->group_id = group_id; |
2032 | read_info->mem = mem; | |
71d6a386 RS |
2033 | read_info->offset = offset; |
2034 | read_info->width = width; | |
6fb5fa3c DB |
2035 | read_info->next = insn_info->read_rec; |
2036 | insn_info->read_rec = read_info; | |
ac6929b5 RB |
2037 | if (group_id < 0) |
2038 | mem_addr = base->val_rtx; | |
6216f94e JJ |
2039 | else |
2040 | { | |
ac6929b5 RB |
2041 | group_info *group = rtx_group_vec[group_id]; |
2042 | mem_addr = group->canon_base_addr; | |
6216f94e | 2043 | } |
ac6929b5 RB |
2044 | if (offset) |
2045 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); | |
6fb5fa3c | 2046 | |
ac6929b5 | 2047 | if (group_id >= 0) |
6fb5fa3c DB |
2048 | { |
2049 | /* This is the restricted case where the base is a constant or | |
2050 | the frame pointer and offset is a constant. */ | |
2051 | insn_info_t i_ptr = active_local_stores; | |
2052 | insn_info_t last = NULL; | |
b8698a0f | 2053 | |
456610d3 | 2054 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2055 | { |
2056 | if (width == -1) | |
2057 | fprintf (dump_file, " processing const load gid=%d[BLK]\n", | |
2058 | group_id); | |
2059 | else | |
71d6a386 RS |
2060 | { |
2061 | fprintf (dump_file, " processing const load gid=%d", group_id); | |
2062 | print_range (dump_file, offset, width); | |
2063 | fprintf (dump_file, "\n"); | |
2064 | } | |
6fb5fa3c DB |
2065 | } |
2066 | ||
2067 | while (i_ptr) | |
2068 | { | |
2069 | bool remove = false; | |
fd6daec9 | 2070 | store_info *store_info = i_ptr->store_rec; |
b8698a0f | 2071 | |
6fb5fa3c DB |
2072 | /* Skip the clobbers. */ |
2073 | while (!store_info->is_set) | |
2074 | store_info = store_info->next; | |
b8698a0f | 2075 | |
6fb5fa3c DB |
2076 | /* There are three cases here. */ |
2077 | if (store_info->group_id < 0) | |
2078 | /* We have a cselib store followed by a read from a | |
2079 | const base. */ | |
b8698a0f L |
2080 | remove |
2081 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2082 | GET_MODE (store_info->mem), |
2083 | store_info->mem_addr, | |
53d9622b | 2084 | mem, mem_addr); |
b8698a0f | 2085 | |
6fb5fa3c DB |
2086 | else if (group_id == store_info->group_id) |
2087 | { | |
2088 | /* This is a block mode load. We may get lucky and | |
2089 | canon_true_dependence may save the day. */ | |
2090 | if (width == -1) | |
b8698a0f L |
2091 | remove |
2092 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2093 | GET_MODE (store_info->mem), |
2094 | store_info->mem_addr, | |
53d9622b | 2095 | mem, mem_addr); |
b8698a0f | 2096 | |
6fb5fa3c DB |
2097 | /* If this read is just reading back something that we just |
2098 | stored, rewrite the read. */ | |
b8698a0f | 2099 | else |
6fb5fa3c DB |
2100 | { |
2101 | if (store_info->rhs | |
71d6a386 RS |
2102 | && known_subrange_p (offset, width, store_info->offset, |
2103 | store_info->width) | |
8dd5516b | 2104 | && all_positions_needed_p (store_info, |
71d6a386 | 2105 | offset - store_info->offset, |
8dd5516b JJ |
2106 | width) |
2107 | && replace_read (store_info, i_ptr, read_info, | |
2108 | insn_info, loc, bb_info->regs_live)) | |
d7111da8 | 2109 | return; |
8dd5516b | 2110 | |
6fb5fa3c | 2111 | /* The bases are the same, just see if the offsets |
71d6a386 RS |
2112 | could overlap. */ |
2113 | if (ranges_maybe_overlap_p (offset, width, | |
2114 | store_info->offset, | |
2115 | store_info->width)) | |
6fb5fa3c DB |
2116 | remove = true; |
2117 | } | |
2118 | } | |
b8698a0f L |
2119 | |
2120 | /* else | |
6fb5fa3c DB |
2121 | The else case that is missing here is that the |
2122 | bases are constant but different. There is nothing | |
2123 | to do here because there is no overlap. */ | |
b8698a0f | 2124 | |
6fb5fa3c DB |
2125 | if (remove) |
2126 | { | |
456610d3 | 2127 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2128 | dump_insn_info ("removing from active", i_ptr); |
2129 | ||
dabd47e7 | 2130 | active_local_stores_len--; |
6fb5fa3c DB |
2131 | if (last) |
2132 | last->next_local_store = i_ptr->next_local_store; | |
2133 | else | |
2134 | active_local_stores = i_ptr->next_local_store; | |
2135 | } | |
2136 | else | |
2137 | last = i_ptr; | |
2138 | i_ptr = i_ptr->next_local_store; | |
2139 | } | |
2140 | } | |
b8698a0f | 2141 | else |
6fb5fa3c DB |
2142 | { |
2143 | insn_info_t i_ptr = active_local_stores; | |
2144 | insn_info_t last = NULL; | |
456610d3 | 2145 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2146 | { |
2147 | fprintf (dump_file, " processing cselib load mem:"); | |
2148 | print_inline_rtx (dump_file, mem, 0); | |
2149 | fprintf (dump_file, "\n"); | |
2150 | } | |
2151 | ||
2152 | while (i_ptr) | |
2153 | { | |
2154 | bool remove = false; | |
fd6daec9 | 2155 | store_info *store_info = i_ptr->store_rec; |
b8698a0f | 2156 | |
456610d3 | 2157 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2158 | fprintf (dump_file, " processing cselib load against insn %d\n", |
2159 | INSN_UID (i_ptr->insn)); | |
2160 | ||
2161 | /* Skip the clobbers. */ | |
2162 | while (!store_info->is_set) | |
2163 | store_info = store_info->next; | |
2164 | ||
2165 | /* If this read is just reading back something that we just | |
2166 | stored, rewrite the read. */ | |
2167 | if (store_info->rhs | |
2168 | && store_info->group_id == -1 | |
2169 | && store_info->cse_base == base | |
71d6a386 RS |
2170 | && known_subrange_p (offset, width, store_info->offset, |
2171 | store_info->width) | |
8dd5516b | 2172 | && all_positions_needed_p (store_info, |
71d6a386 | 2173 | offset - store_info->offset, width) |
8dd5516b JJ |
2174 | && replace_read (store_info, i_ptr, read_info, insn_info, loc, |
2175 | bb_info->regs_live)) | |
d7111da8 | 2176 | return; |
6fb5fa3c | 2177 | |
ac6929b5 RB |
2178 | remove = canon_true_dependence (store_info->mem, |
2179 | GET_MODE (store_info->mem), | |
2180 | store_info->mem_addr, | |
2181 | mem, mem_addr); | |
b8698a0f | 2182 | |
6fb5fa3c DB |
2183 | if (remove) |
2184 | { | |
456610d3 | 2185 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2186 | dump_insn_info ("removing from active", i_ptr); |
b8698a0f | 2187 | |
dabd47e7 | 2188 | active_local_stores_len--; |
6fb5fa3c DB |
2189 | if (last) |
2190 | last->next_local_store = i_ptr->next_local_store; | |
2191 | else | |
2192 | active_local_stores = i_ptr->next_local_store; | |
2193 | } | |
2194 | else | |
2195 | last = i_ptr; | |
2196 | i_ptr = i_ptr->next_local_store; | |
2197 | } | |
2198 | } | |
6fb5fa3c DB |
2199 | } |
2200 | ||
d7111da8 | 2201 | /* A note_uses callback in which DATA points the INSN_INFO for |
6fb5fa3c DB |
2202 | as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns |
2203 | true for any part of *LOC. */ | |
2204 | ||
2205 | static void | |
2206 | check_mem_read_use (rtx *loc, void *data) | |
2207 | { | |
d7111da8 RS |
2208 | subrtx_ptr_iterator::array_type array; |
2209 | FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST) | |
2210 | { | |
2211 | rtx *loc = *iter; | |
2212 | if (MEM_P (*loc)) | |
2213 | check_mem_read_rtx (loc, (bb_info_t) data); | |
2214 | } | |
6fb5fa3c DB |
2215 | } |
2216 | ||
8dd5516b JJ |
2217 | |
2218 | /* Get arguments passed to CALL_INSN. Return TRUE if successful. | |
2219 | So far it only handles arguments passed in registers. */ | |
2220 | ||
2221 | static bool | |
2222 | get_call_args (rtx call_insn, tree fn, rtx *args, int nargs) | |
2223 | { | |
d5cc9181 JR |
2224 | CUMULATIVE_ARGS args_so_far_v; |
2225 | cumulative_args_t args_so_far; | |
8dd5516b JJ |
2226 | tree arg; |
2227 | int idx; | |
2228 | ||
d5cc9181 JR |
2229 | INIT_CUMULATIVE_ARGS (args_so_far_v, TREE_TYPE (fn), NULL_RTX, 0, 3); |
2230 | args_so_far = pack_cumulative_args (&args_so_far_v); | |
8dd5516b JJ |
2231 | |
2232 | arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2233 | for (idx = 0; | |
2234 | arg != void_list_node && idx < nargs; | |
2235 | arg = TREE_CHAIN (arg), idx++) | |
2236 | { | |
b4206259 | 2237 | scalar_int_mode mode; |
3c07301f | 2238 | rtx reg, link, tmp; |
b4206259 RS |
2239 | |
2240 | if (!is_int_mode (TYPE_MODE (TREE_VALUE (arg)), &mode)) | |
2241 | return false; | |
2242 | ||
d5cc9181 | 2243 | reg = targetm.calls.function_arg (args_so_far, mode, NULL_TREE, true); |
b4206259 | 2244 | if (!reg || !REG_P (reg) || GET_MODE (reg) != mode) |
8dd5516b JJ |
2245 | return false; |
2246 | ||
2247 | for (link = CALL_INSN_FUNCTION_USAGE (call_insn); | |
2248 | link; | |
2249 | link = XEXP (link, 1)) | |
2250 | if (GET_CODE (XEXP (link, 0)) == USE) | |
2251 | { | |
b4206259 | 2252 | scalar_int_mode arg_mode; |
8dd5516b JJ |
2253 | args[idx] = XEXP (XEXP (link, 0), 0); |
2254 | if (REG_P (args[idx]) | |
2255 | && REGNO (args[idx]) == REGNO (reg) | |
2256 | && (GET_MODE (args[idx]) == mode | |
b4206259 RS |
2257 | || (is_int_mode (GET_MODE (args[idx]), &arg_mode) |
2258 | && (GET_MODE_SIZE (arg_mode) <= UNITS_PER_WORD) | |
2259 | && (GET_MODE_SIZE (arg_mode) > GET_MODE_SIZE (mode))))) | |
8dd5516b JJ |
2260 | break; |
2261 | } | |
2262 | if (!link) | |
2263 | return false; | |
2264 | ||
2265 | tmp = cselib_expand_value_rtx (args[idx], scratch, 5); | |
2266 | if (GET_MODE (args[idx]) != mode) | |
2267 | { | |
2268 | if (!tmp || !CONST_INT_P (tmp)) | |
2269 | return false; | |
6d26322f | 2270 | tmp = gen_int_mode (INTVAL (tmp), mode); |
8dd5516b JJ |
2271 | } |
2272 | if (tmp) | |
2273 | args[idx] = tmp; | |
2274 | ||
d5cc9181 | 2275 | targetm.calls.function_arg_advance (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2276 | } |
2277 | if (arg != void_list_node || idx != nargs) | |
2278 | return false; | |
2279 | return true; | |
2280 | } | |
2281 | ||
9e582b1d JR |
2282 | /* Return a bitmap of the fixed registers contained in IN. */ |
2283 | ||
2284 | static bitmap | |
2285 | copy_fixed_regs (const_bitmap in) | |
2286 | { | |
2287 | bitmap ret; | |
2288 | ||
2289 | ret = ALLOC_REG_SET (NULL); | |
2290 | bitmap_and (ret, in, fixed_reg_set_regset); | |
2291 | return ret; | |
2292 | } | |
8dd5516b | 2293 | |
6fb5fa3c DB |
2294 | /* Apply record_store to all candidate stores in INSN. Mark INSN |
2295 | if some part of it is not a candidate store and assigns to a | |
2296 | non-register target. */ | |
2297 | ||
2298 | static void | |
dd60a84c | 2299 | scan_insn (bb_info_t bb_info, rtx_insn *insn) |
6fb5fa3c DB |
2300 | { |
2301 | rtx body; | |
fb0b2914 | 2302 | insn_info_type *insn_info = insn_info_type_pool.allocate (); |
6fb5fa3c | 2303 | int mems_found = 0; |
da6603c6 | 2304 | memset (insn_info, 0, sizeof (struct insn_info_type)); |
6fb5fa3c | 2305 | |
456610d3 | 2306 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2307 | fprintf (dump_file, "\n**scanning insn=%d\n", |
2308 | INSN_UID (insn)); | |
2309 | ||
2310 | insn_info->prev_insn = bb_info->last_insn; | |
2311 | insn_info->insn = insn; | |
2312 | bb_info->last_insn = insn_info; | |
b8698a0f | 2313 | |
b5b8b0ac AO |
2314 | if (DEBUG_INSN_P (insn)) |
2315 | { | |
2316 | insn_info->cannot_delete = true; | |
2317 | return; | |
2318 | } | |
6fb5fa3c | 2319 | |
6fb5fa3c DB |
2320 | /* Look at all of the uses in the insn. */ |
2321 | note_uses (&PATTERN (insn), check_mem_read_use, bb_info); | |
2322 | ||
2323 | if (CALL_P (insn)) | |
2324 | { | |
8dd5516b | 2325 | bool const_call; |
ee516de9 | 2326 | rtx call, sym; |
8dd5516b JJ |
2327 | tree memset_call = NULL_TREE; |
2328 | ||
6fb5fa3c | 2329 | insn_info->cannot_delete = true; |
50f0f366 | 2330 | |
6fb5fa3c | 2331 | /* Const functions cannot do anything bad i.e. read memory, |
50f0f366 | 2332 | however, they can read their parameters which may have |
8dd5516b JJ |
2333 | been pushed onto the stack. |
2334 | memset and bzero don't read memory either. */ | |
2335 | const_call = RTL_CONST_CALL_P (insn); | |
ee516de9 EB |
2336 | if (!const_call |
2337 | && (call = get_call_rtx_from (insn)) | |
2338 | && (sym = XEXP (XEXP (call, 0), 0)) | |
2339 | && GET_CODE (sym) == SYMBOL_REF | |
2340 | && SYMBOL_REF_DECL (sym) | |
2341 | && TREE_CODE (SYMBOL_REF_DECL (sym)) == FUNCTION_DECL | |
2342 | && DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (sym)) == BUILT_IN_NORMAL | |
2343 | && DECL_FUNCTION_CODE (SYMBOL_REF_DECL (sym)) == BUILT_IN_MEMSET) | |
2344 | memset_call = SYMBOL_REF_DECL (sym); | |
2345 | ||
8dd5516b | 2346 | if (const_call || memset_call) |
6fb5fa3c DB |
2347 | { |
2348 | insn_info_t i_ptr = active_local_stores; | |
2349 | insn_info_t last = NULL; | |
2350 | ||
456610d3 | 2351 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2352 | fprintf (dump_file, "%s call %d\n", |
2353 | const_call ? "const" : "memset", INSN_UID (insn)); | |
6fb5fa3c | 2354 | |
64520bdc | 2355 | /* See the head comment of the frame_read field. */ |
57534689 JJ |
2356 | if (reload_completed |
2357 | /* Tail calls are storing their arguments using | |
2358 | arg pointer. If it is a frame pointer on the target, | |
2359 | even before reload we need to kill frame pointer based | |
2360 | stores. */ | |
2361 | || (SIBLING_CALL_P (insn) | |
2362 | && HARD_FRAME_POINTER_IS_ARG_POINTER)) | |
64520bdc EB |
2363 | insn_info->frame_read = true; |
2364 | ||
2365 | /* Loop over the active stores and remove those which are | |
2366 | killed by the const function call. */ | |
6fb5fa3c DB |
2367 | while (i_ptr) |
2368 | { | |
64520bdc EB |
2369 | bool remove_store = false; |
2370 | ||
2371 | /* The stack pointer based stores are always killed. */ | |
50f0f366 | 2372 | if (i_ptr->stack_pointer_based) |
64520bdc EB |
2373 | remove_store = true; |
2374 | ||
2375 | /* If the frame is read, the frame related stores are killed. */ | |
2376 | else if (insn_info->frame_read) | |
2377 | { | |
fd6daec9 | 2378 | store_info *store_info = i_ptr->store_rec; |
64520bdc EB |
2379 | |
2380 | /* Skip the clobbers. */ | |
2381 | while (!store_info->is_set) | |
2382 | store_info = store_info->next; | |
2383 | ||
2384 | if (store_info->group_id >= 0 | |
9771b263 | 2385 | && rtx_group_vec[store_info->group_id]->frame_related) |
64520bdc EB |
2386 | remove_store = true; |
2387 | } | |
2388 | ||
2389 | if (remove_store) | |
6fb5fa3c | 2390 | { |
456610d3 | 2391 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2392 | dump_insn_info ("removing from active", i_ptr); |
b8698a0f | 2393 | |
dabd47e7 | 2394 | active_local_stores_len--; |
6fb5fa3c DB |
2395 | if (last) |
2396 | last->next_local_store = i_ptr->next_local_store; | |
2397 | else | |
2398 | active_local_stores = i_ptr->next_local_store; | |
2399 | } | |
2400 | else | |
2401 | last = i_ptr; | |
64520bdc | 2402 | |
6fb5fa3c DB |
2403 | i_ptr = i_ptr->next_local_store; |
2404 | } | |
8dd5516b JJ |
2405 | |
2406 | if (memset_call) | |
2407 | { | |
2408 | rtx args[3]; | |
2409 | if (get_call_args (insn, memset_call, args, 3) | |
2410 | && CONST_INT_P (args[1]) | |
2411 | && CONST_INT_P (args[2]) | |
2412 | && INTVAL (args[2]) > 0) | |
2413 | { | |
2414 | rtx mem = gen_rtx_MEM (BLKmode, args[0]); | |
f5541398 | 2415 | set_mem_size (mem, INTVAL (args[2])); |
f7df4a84 | 2416 | body = gen_rtx_SET (mem, args[1]); |
8dd5516b | 2417 | mems_found += record_store (body, bb_info); |
456610d3 | 2418 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2419 | fprintf (dump_file, "handling memset as BLKmode store\n"); |
2420 | if (mems_found == 1) | |
2421 | { | |
dabd47e7 JJ |
2422 | if (active_local_stores_len++ |
2423 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2424 | { | |
2425 | active_local_stores_len = 1; | |
2426 | active_local_stores = NULL; | |
2427 | } | |
9e582b1d JR |
2428 | insn_info->fixed_regs_live |
2429 | = copy_fixed_regs (bb_info->regs_live); | |
8dd5516b JJ |
2430 | insn_info->next_local_store = active_local_stores; |
2431 | active_local_stores = insn_info; | |
2432 | } | |
2433 | } | |
a2ad54a0 JJ |
2434 | else |
2435 | clear_rhs_from_active_local_stores (); | |
8dd5516b | 2436 | } |
6fb5fa3c | 2437 | } |
57534689 JJ |
2438 | else if (SIBLING_CALL_P (insn) && reload_completed) |
2439 | /* Arguments for a sibling call that are pushed to memory are passed | |
2440 | using the incoming argument pointer of the current function. After | |
2441 | reload that might be (and likely is) frame pointer based. */ | |
2442 | add_wild_read (bb_info); | |
50f0f366 | 2443 | else |
d26c7090 ER |
2444 | /* Every other call, including pure functions, may read any memory |
2445 | that is not relative to the frame. */ | |
2446 | add_non_frame_wild_read (bb_info); | |
50f0f366 | 2447 | |
6fb5fa3c DB |
2448 | return; |
2449 | } | |
2450 | ||
2451 | /* Assuming that there are sets in these insns, we cannot delete | |
2452 | them. */ | |
2453 | if ((GET_CODE (PATTERN (insn)) == CLOBBER) | |
0a64eeca | 2454 | || volatile_refs_p (PATTERN (insn)) |
2da02156 | 2455 | || (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) |
6fb5fa3c DB |
2456 | || (RTX_FRAME_RELATED_P (insn)) |
2457 | || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX)) | |
2458 | insn_info->cannot_delete = true; | |
b8698a0f | 2459 | |
6fb5fa3c DB |
2460 | body = PATTERN (insn); |
2461 | if (GET_CODE (body) == PARALLEL) | |
2462 | { | |
2463 | int i; | |
2464 | for (i = 0; i < XVECLEN (body, 0); i++) | |
2465 | mems_found += record_store (XVECEXP (body, 0, i), bb_info); | |
2466 | } | |
2467 | else | |
2468 | mems_found += record_store (body, bb_info); | |
2469 | ||
456610d3 | 2470 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 2471 | fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n", |
6fb5fa3c DB |
2472 | mems_found, insn_info->cannot_delete ? "true" : "false"); |
2473 | ||
8dd5516b JJ |
2474 | /* If we found some sets of mems, add it into the active_local_stores so |
2475 | that it can be locally deleted if found dead or used for | |
2476 | replace_read and redundant constant store elimination. Otherwise mark | |
2477 | it as cannot delete. This simplifies the processing later. */ | |
2478 | if (mems_found == 1) | |
6fb5fa3c | 2479 | { |
dabd47e7 JJ |
2480 | if (active_local_stores_len++ |
2481 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2482 | { | |
2483 | active_local_stores_len = 1; | |
2484 | active_local_stores = NULL; | |
2485 | } | |
9e582b1d | 2486 | insn_info->fixed_regs_live = copy_fixed_regs (bb_info->regs_live); |
6fb5fa3c DB |
2487 | insn_info->next_local_store = active_local_stores; |
2488 | active_local_stores = insn_info; | |
2489 | } | |
2490 | else | |
2491 | insn_info->cannot_delete = true; | |
2492 | } | |
2493 | ||
2494 | ||
2495 | /* Remove BASE from the set of active_local_stores. This is a | |
2496 | callback from cselib that is used to get rid of the stores in | |
2497 | active_local_stores. */ | |
2498 | ||
2499 | static void | |
2500 | remove_useless_values (cselib_val *base) | |
2501 | { | |
2502 | insn_info_t insn_info = active_local_stores; | |
2503 | insn_info_t last = NULL; | |
2504 | ||
2505 | while (insn_info) | |
2506 | { | |
fd6daec9 | 2507 | store_info *store_info = insn_info->store_rec; |
60564289 | 2508 | bool del = false; |
6fb5fa3c DB |
2509 | |
2510 | /* If ANY of the store_infos match the cselib group that is | |
2511 | being deleted, then the insn can not be deleted. */ | |
2512 | while (store_info) | |
2513 | { | |
b8698a0f | 2514 | if ((store_info->group_id == -1) |
6fb5fa3c DB |
2515 | && (store_info->cse_base == base)) |
2516 | { | |
60564289 | 2517 | del = true; |
6fb5fa3c DB |
2518 | break; |
2519 | } | |
2520 | store_info = store_info->next; | |
2521 | } | |
2522 | ||
60564289 | 2523 | if (del) |
6fb5fa3c | 2524 | { |
dabd47e7 | 2525 | active_local_stores_len--; |
6fb5fa3c DB |
2526 | if (last) |
2527 | last->next_local_store = insn_info->next_local_store; | |
2528 | else | |
2529 | active_local_stores = insn_info->next_local_store; | |
2530 | free_store_info (insn_info); | |
2531 | } | |
2532 | else | |
2533 | last = insn_info; | |
b8698a0f | 2534 | |
6fb5fa3c DB |
2535 | insn_info = insn_info->next_local_store; |
2536 | } | |
2537 | } | |
2538 | ||
2539 | ||
2540 | /* Do all of step 1. */ | |
2541 | ||
2542 | static void | |
2543 | dse_step1 (void) | |
2544 | { | |
2545 | basic_block bb; | |
3f9b14ff | 2546 | bitmap regs_live = BITMAP_ALLOC (®_obstack); |
b8698a0f | 2547 | |
457eeaae | 2548 | cselib_init (0); |
6fb5fa3c DB |
2549 | all_blocks = BITMAP_ALLOC (NULL); |
2550 | bitmap_set_bit (all_blocks, ENTRY_BLOCK); | |
2551 | bitmap_set_bit (all_blocks, EXIT_BLOCK); | |
2552 | ||
04a90bec | 2553 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
2554 | { |
2555 | insn_info_t ptr; | |
fb0b2914 | 2556 | bb_info_t bb_info = dse_bb_info_type_pool.allocate (); |
6fb5fa3c | 2557 | |
da6603c6 | 2558 | memset (bb_info, 0, sizeof (dse_bb_info_type)); |
6fb5fa3c | 2559 | bitmap_set_bit (all_blocks, bb->index); |
02b47899 KZ |
2560 | bb_info->regs_live = regs_live; |
2561 | ||
2562 | bitmap_copy (regs_live, DF_LR_IN (bb)); | |
2563 | df_simulate_initialize_forwards (bb, regs_live); | |
6fb5fa3c DB |
2564 | |
2565 | bb_table[bb->index] = bb_info; | |
2566 | cselib_discard_hook = remove_useless_values; | |
2567 | ||
2568 | if (bb->index >= NUM_FIXED_BLOCKS) | |
2569 | { | |
dd60a84c | 2570 | rtx_insn *insn; |
6fb5fa3c | 2571 | |
6fb5fa3c | 2572 | active_local_stores = NULL; |
dabd47e7 | 2573 | active_local_stores_len = 0; |
6fb5fa3c | 2574 | cselib_clear_table (); |
b8698a0f | 2575 | |
6fb5fa3c DB |
2576 | /* Scan the insns. */ |
2577 | FOR_BB_INSNS (bb, insn) | |
2578 | { | |
2579 | if (INSN_P (insn)) | |
2580 | scan_insn (bb_info, insn); | |
2581 | cselib_process_insn (insn); | |
02b47899 KZ |
2582 | if (INSN_P (insn)) |
2583 | df_simulate_one_insn_forwards (bb, insn, regs_live); | |
6fb5fa3c | 2584 | } |
b8698a0f | 2585 | |
6fb5fa3c DB |
2586 | /* This is something of a hack, because the global algorithm |
2587 | is supposed to take care of the case where stores go dead | |
2588 | at the end of the function. However, the global | |
2589 | algorithm must take a more conservative view of block | |
2590 | mode reads than the local alg does. So to get the case | |
2591 | where you have a store to the frame followed by a non | |
0d52bcc1 | 2592 | overlapping block more read, we look at the active local |
6fb5fa3c DB |
2593 | stores at the end of the function and delete all of the |
2594 | frame and spill based ones. */ | |
2595 | if (stores_off_frame_dead_at_return | |
2596 | && (EDGE_COUNT (bb->succs) == 0 | |
2597 | || (single_succ_p (bb) | |
fefa31b5 | 2598 | && single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (cfun) |
e3b5732b | 2599 | && ! crtl->calls_eh_return))) |
6fb5fa3c DB |
2600 | { |
2601 | insn_info_t i_ptr = active_local_stores; | |
2602 | while (i_ptr) | |
2603 | { | |
fd6daec9 | 2604 | store_info *store_info = i_ptr->store_rec; |
6fb5fa3c DB |
2605 | |
2606 | /* Skip the clobbers. */ | |
2607 | while (!store_info->is_set) | |
2608 | store_info = store_info->next; | |
ac6929b5 RB |
2609 | if (store_info->group_id >= 0) |
2610 | { | |
2611 | group_info *group = rtx_group_vec[store_info->group_id]; | |
2612 | if (group->frame_related && !i_ptr->cannot_delete) | |
2613 | delete_dead_store_insn (i_ptr); | |
2614 | } | |
6fb5fa3c DB |
2615 | |
2616 | i_ptr = i_ptr->next_local_store; | |
2617 | } | |
2618 | } | |
2619 | ||
2620 | /* Get rid of the loads that were discovered in | |
2621 | replace_read. Cselib is finished with this block. */ | |
2622 | while (deferred_change_list) | |
2623 | { | |
fd6daec9 | 2624 | deferred_change *next = deferred_change_list->next; |
6fb5fa3c DB |
2625 | |
2626 | /* There is no reason to validate this change. That was | |
2627 | done earlier. */ | |
2628 | *deferred_change_list->loc = deferred_change_list->reg; | |
fb0b2914 | 2629 | deferred_change_pool.remove (deferred_change_list); |
6fb5fa3c DB |
2630 | deferred_change_list = next; |
2631 | } | |
2632 | ||
2633 | /* Get rid of all of the cselib based store_infos in this | |
2634 | block and mark the containing insns as not being | |
2635 | deletable. */ | |
2636 | ptr = bb_info->last_insn; | |
2637 | while (ptr) | |
2638 | { | |
2639 | if (ptr->contains_cselib_groups) | |
8dd5516b | 2640 | { |
fd6daec9 | 2641 | store_info *s_info = ptr->store_rec; |
8dd5516b JJ |
2642 | while (s_info && !s_info->is_set) |
2643 | s_info = s_info->next; | |
2644 | if (s_info | |
2645 | && s_info->redundant_reason | |
2646 | && s_info->redundant_reason->insn | |
2647 | && !ptr->cannot_delete) | |
2648 | { | |
456610d3 | 2649 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2650 | fprintf (dump_file, "Locally deleting insn %d " |
2651 | "because insn %d stores the " | |
2652 | "same value and couldn't be " | |
2653 | "eliminated\n", | |
2654 | INSN_UID (ptr->insn), | |
2655 | INSN_UID (s_info->redundant_reason->insn)); | |
2656 | delete_dead_store_insn (ptr); | |
2657 | } | |
8dd5516b JJ |
2658 | free_store_info (ptr); |
2659 | } | |
2660 | else | |
2661 | { | |
fd6daec9 | 2662 | store_info *s_info; |
8dd5516b JJ |
2663 | |
2664 | /* Free at least positions_needed bitmaps. */ | |
2665 | for (s_info = ptr->store_rec; s_info; s_info = s_info->next) | |
2666 | if (s_info->is_large) | |
2667 | { | |
dc491a25 | 2668 | BITMAP_FREE (s_info->positions_needed.large.bmap); |
8dd5516b JJ |
2669 | s_info->is_large = false; |
2670 | } | |
2671 | } | |
6fb5fa3c DB |
2672 | ptr = ptr->prev_insn; |
2673 | } | |
2674 | ||
da6603c6 | 2675 | cse_store_info_pool.release (); |
6fb5fa3c | 2676 | } |
02b47899 | 2677 | bb_info->regs_live = NULL; |
6fb5fa3c DB |
2678 | } |
2679 | ||
02b47899 | 2680 | BITMAP_FREE (regs_live); |
6fb5fa3c | 2681 | cselib_finish (); |
c203e8a7 | 2682 | rtx_group_table->empty (); |
6fb5fa3c DB |
2683 | } |
2684 | ||
2685 | \f | |
2686 | /*---------------------------------------------------------------------------- | |
2687 | Second step. | |
2688 | ||
2689 | Assign each byte position in the stores that we are going to | |
2690 | analyze globally to a position in the bitmaps. Returns true if | |
6ed3da00 | 2691 | there are any bit positions assigned. |
6fb5fa3c DB |
2692 | ----------------------------------------------------------------------------*/ |
2693 | ||
2694 | static void | |
2695 | dse_step2_init (void) | |
2696 | { | |
2697 | unsigned int i; | |
fd6daec9 | 2698 | group_info *group; |
6fb5fa3c | 2699 | |
9771b263 | 2700 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2701 | { |
2702 | /* For all non stack related bases, we only consider a store to | |
2703 | be deletable if there are two or more stores for that | |
2704 | position. This is because it takes one store to make the | |
2705 | other store redundant. However, for the stores that are | |
2706 | stack related, we consider them if there is only one store | |
2707 | for the position. We do this because the stack related | |
2708 | stores can be deleted if their is no read between them and | |
2709 | the end of the function. | |
b8698a0f | 2710 | |
6fb5fa3c DB |
2711 | To make this work in the current framework, we take the stack |
2712 | related bases add all of the bits from store1 into store2. | |
2713 | This has the effect of making the eligible even if there is | |
2714 | only one store. */ | |
2715 | ||
2716 | if (stores_off_frame_dead_at_return && group->frame_related) | |
2717 | { | |
2718 | bitmap_ior_into (group->store2_n, group->store1_n); | |
2719 | bitmap_ior_into (group->store2_p, group->store1_p); | |
456610d3 | 2720 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 2721 | fprintf (dump_file, "group %d is frame related ", i); |
6fb5fa3c DB |
2722 | } |
2723 | ||
2724 | group->offset_map_size_n++; | |
3f9b14ff SB |
2725 | group->offset_map_n = XOBNEWVEC (&dse_obstack, int, |
2726 | group->offset_map_size_n); | |
6fb5fa3c | 2727 | group->offset_map_size_p++; |
3f9b14ff SB |
2728 | group->offset_map_p = XOBNEWVEC (&dse_obstack, int, |
2729 | group->offset_map_size_p); | |
6fb5fa3c | 2730 | group->process_globally = false; |
456610d3 | 2731 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2732 | { |
b8698a0f | 2733 | fprintf (dump_file, "group %d(%d+%d): ", i, |
6fb5fa3c DB |
2734 | (int)bitmap_count_bits (group->store2_n), |
2735 | (int)bitmap_count_bits (group->store2_p)); | |
2736 | bitmap_print (dump_file, group->store2_n, "n ", " "); | |
2737 | bitmap_print (dump_file, group->store2_p, "p ", "\n"); | |
2738 | } | |
2739 | } | |
2740 | } | |
2741 | ||
2742 | ||
ac6929b5 | 2743 | /* Init the offset tables. */ |
6fb5fa3c DB |
2744 | |
2745 | static bool | |
ac6929b5 | 2746 | dse_step2 (void) |
6fb5fa3c DB |
2747 | { |
2748 | unsigned int i; | |
fd6daec9 | 2749 | group_info *group; |
6fb5fa3c DB |
2750 | /* Position 0 is unused because 0 is used in the maps to mean |
2751 | unused. */ | |
2752 | current_position = 1; | |
9771b263 | 2753 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2754 | { |
2755 | bitmap_iterator bi; | |
2756 | unsigned int j; | |
2757 | ||
c3284718 RS |
2758 | memset (group->offset_map_n, 0, sizeof (int) * group->offset_map_size_n); |
2759 | memset (group->offset_map_p, 0, sizeof (int) * group->offset_map_size_p); | |
6fb5fa3c DB |
2760 | bitmap_clear (group->group_kill); |
2761 | ||
2762 | EXECUTE_IF_SET_IN_BITMAP (group->store2_n, 0, j, bi) | |
2763 | { | |
2764 | bitmap_set_bit (group->group_kill, current_position); | |
d26c7090 ER |
2765 | if (bitmap_bit_p (group->escaped_n, j)) |
2766 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2767 | group->offset_map_n[j] = current_position++; |
2768 | group->process_globally = true; | |
2769 | } | |
2770 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2771 | { | |
b8698a0f | 2772 | bitmap_set_bit (group->group_kill, current_position); |
d26c7090 ER |
2773 | if (bitmap_bit_p (group->escaped_p, j)) |
2774 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2775 | group->offset_map_p[j] = current_position++; |
2776 | group->process_globally = true; | |
2777 | } | |
2778 | } | |
2779 | return current_position != 1; | |
2780 | } | |
2781 | ||
2782 | ||
6fb5fa3c DB |
2783 | \f |
2784 | /*---------------------------------------------------------------------------- | |
2785 | Third step. | |
b8698a0f | 2786 | |
6fb5fa3c DB |
2787 | Build the bit vectors for the transfer functions. |
2788 | ----------------------------------------------------------------------------*/ | |
2789 | ||
2790 | ||
6fb5fa3c DB |
2791 | /* Look up the bitmap index for OFFSET in GROUP_INFO. If it is not |
2792 | there, return 0. */ | |
2793 | ||
2794 | static int | |
fd6daec9 | 2795 | get_bitmap_index (group_info *group_info, HOST_WIDE_INT offset) |
6fb5fa3c DB |
2796 | { |
2797 | if (offset < 0) | |
2798 | { | |
2799 | HOST_WIDE_INT offset_p = -offset; | |
2800 | if (offset_p >= group_info->offset_map_size_n) | |
2801 | return 0; | |
2802 | return group_info->offset_map_n[offset_p]; | |
2803 | } | |
2804 | else | |
2805 | { | |
2806 | if (offset >= group_info->offset_map_size_p) | |
2807 | return 0; | |
2808 | return group_info->offset_map_p[offset]; | |
2809 | } | |
2810 | } | |
2811 | ||
2812 | ||
2813 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
2814 | may be NULL. */ | |
2815 | ||
b8698a0f | 2816 | static void |
ac6929b5 | 2817 | scan_stores (store_info *store_info, bitmap gen, bitmap kill) |
6fb5fa3c DB |
2818 | { |
2819 | while (store_info) | |
2820 | { | |
2821 | HOST_WIDE_INT i; | |
fd6daec9 | 2822 | group_info *group_info |
9771b263 | 2823 | = rtx_group_vec[store_info->group_id]; |
6fb5fa3c | 2824 | if (group_info->process_globally) |
71d6a386 RS |
2825 | { |
2826 | HOST_WIDE_INT end = store_info->offset + store_info->width; | |
2827 | for (i = store_info->offset; i < end; i++) | |
2828 | { | |
2829 | int index = get_bitmap_index (group_info, i); | |
2830 | if (index != 0) | |
2831 | { | |
2832 | bitmap_set_bit (gen, index); | |
2833 | if (kill) | |
2834 | bitmap_clear_bit (kill, index); | |
2835 | } | |
2836 | } | |
2837 | } | |
6fb5fa3c DB |
2838 | store_info = store_info->next; |
2839 | } | |
2840 | } | |
2841 | ||
2842 | ||
6fb5fa3c DB |
2843 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL |
2844 | may be NULL. */ | |
2845 | ||
2846 | static void | |
ac6929b5 | 2847 | scan_reads (insn_info_t insn_info, bitmap gen, bitmap kill) |
6fb5fa3c DB |
2848 | { |
2849 | read_info_t read_info = insn_info->read_rec; | |
2850 | int i; | |
fd6daec9 | 2851 | group_info *group; |
6fb5fa3c | 2852 | |
64520bdc EB |
2853 | /* If this insn reads the frame, kill all the frame related stores. */ |
2854 | if (insn_info->frame_read) | |
2855 | { | |
9771b263 | 2856 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
64520bdc EB |
2857 | if (group->process_globally && group->frame_related) |
2858 | { | |
2859 | if (kill) | |
2860 | bitmap_ior_into (kill, group->group_kill); | |
b8698a0f | 2861 | bitmap_and_compl_into (gen, group->group_kill); |
64520bdc EB |
2862 | } |
2863 | } | |
d26c7090 ER |
2864 | if (insn_info->non_frame_wild_read) |
2865 | { | |
2866 | /* Kill all non-frame related stores. Kill all stores of variables that | |
2867 | escape. */ | |
2868 | if (kill) | |
2869 | bitmap_ior_into (kill, kill_on_calls); | |
2870 | bitmap_and_compl_into (gen, kill_on_calls); | |
9771b263 | 2871 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
d26c7090 ER |
2872 | if (group->process_globally && !group->frame_related) |
2873 | { | |
2874 | if (kill) | |
2875 | bitmap_ior_into (kill, group->group_kill); | |
2876 | bitmap_and_compl_into (gen, group->group_kill); | |
2877 | } | |
2878 | } | |
6fb5fa3c DB |
2879 | while (read_info) |
2880 | { | |
9771b263 | 2881 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2882 | { |
2883 | if (group->process_globally) | |
2884 | { | |
2885 | if (i == read_info->group_id) | |
2886 | { | |
71d6a386 | 2887 | if (!known_size_p (read_info->width)) |
6fb5fa3c | 2888 | { |
71d6a386 | 2889 | /* Handle block mode reads. */ |
6fb5fa3c DB |
2890 | if (kill) |
2891 | bitmap_ior_into (kill, group->group_kill); | |
2892 | bitmap_and_compl_into (gen, group->group_kill); | |
2893 | } | |
2894 | else | |
2895 | { | |
2896 | /* The groups are the same, just process the | |
2897 | offsets. */ | |
2898 | HOST_WIDE_INT j; | |
71d6a386 RS |
2899 | HOST_WIDE_INT end = read_info->offset + read_info->width; |
2900 | for (j = read_info->offset; j < end; j++) | |
6fb5fa3c DB |
2901 | { |
2902 | int index = get_bitmap_index (group, j); | |
2903 | if (index != 0) | |
2904 | { | |
2905 | if (kill) | |
2906 | bitmap_set_bit (kill, index); | |
2907 | bitmap_clear_bit (gen, index); | |
2908 | } | |
2909 | } | |
2910 | } | |
2911 | } | |
2912 | else | |
2913 | { | |
2914 | /* The groups are different, if the alias sets | |
2915 | conflict, clear the entire group. We only need | |
2916 | to apply this test if the read_info is a cselib | |
2917 | read. Anything with a constant base cannot alias | |
2918 | something else with a different constant | |
2919 | base. */ | |
2920 | if ((read_info->group_id < 0) | |
b8698a0f | 2921 | && canon_true_dependence (group->base_mem, |
d32f725a | 2922 | GET_MODE (group->base_mem), |
6216f94e | 2923 | group->canon_base_addr, |
53d9622b | 2924 | read_info->mem, NULL_RTX)) |
6fb5fa3c DB |
2925 | { |
2926 | if (kill) | |
2927 | bitmap_ior_into (kill, group->group_kill); | |
2928 | bitmap_and_compl_into (gen, group->group_kill); | |
2929 | } | |
2930 | } | |
2931 | } | |
2932 | } | |
b8698a0f | 2933 | |
6fb5fa3c DB |
2934 | read_info = read_info->next; |
2935 | } | |
2936 | } | |
2937 | ||
6fb5fa3c DB |
2938 | |
2939 | /* Return the insn in BB_INFO before the first wild read or if there | |
2940 | are no wild reads in the block, return the last insn. */ | |
2941 | ||
2942 | static insn_info_t | |
2943 | find_insn_before_first_wild_read (bb_info_t bb_info) | |
2944 | { | |
2945 | insn_info_t insn_info = bb_info->last_insn; | |
2946 | insn_info_t last_wild_read = NULL; | |
2947 | ||
2948 | while (insn_info) | |
2949 | { | |
2950 | if (insn_info->wild_read) | |
2951 | { | |
2952 | last_wild_read = insn_info->prev_insn; | |
2953 | /* Block starts with wild read. */ | |
2954 | if (!last_wild_read) | |
2955 | return NULL; | |
2956 | } | |
2957 | ||
2958 | insn_info = insn_info->prev_insn; | |
2959 | } | |
2960 | ||
2961 | if (last_wild_read) | |
2962 | return last_wild_read; | |
2963 | else | |
2964 | return bb_info->last_insn; | |
2965 | } | |
2966 | ||
2967 | ||
2968 | /* Scan the insns in BB_INFO starting at PTR and going to the top of | |
2969 | the block in order to build the gen and kill sets for the block. | |
2970 | We start at ptr which may be the last insn in the block or may be | |
2971 | the first insn with a wild read. In the latter case we are able to | |
2972 | skip the rest of the block because it just does not matter: | |
2973 | anything that happens is hidden by the wild read. */ | |
2974 | ||
2975 | static void | |
ac6929b5 | 2976 | dse_step3_scan (basic_block bb) |
6fb5fa3c DB |
2977 | { |
2978 | bb_info_t bb_info = bb_table[bb->index]; | |
2979 | insn_info_t insn_info; | |
2980 | ||
ac6929b5 | 2981 | insn_info = find_insn_before_first_wild_read (bb_info); |
b8698a0f | 2982 | |
6fb5fa3c DB |
2983 | /* In the spill case or in the no_spill case if there is no wild |
2984 | read in the block, we will need a kill set. */ | |
2985 | if (insn_info == bb_info->last_insn) | |
2986 | { | |
2987 | if (bb_info->kill) | |
2988 | bitmap_clear (bb_info->kill); | |
2989 | else | |
3f9b14ff | 2990 | bb_info->kill = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c | 2991 | } |
b8698a0f | 2992 | else |
6fb5fa3c DB |
2993 | if (bb_info->kill) |
2994 | BITMAP_FREE (bb_info->kill); | |
2995 | ||
2996 | while (insn_info) | |
2997 | { | |
2998 | /* There may have been code deleted by the dce pass run before | |
2999 | this phase. */ | |
3000 | if (insn_info->insn && INSN_P (insn_info->insn)) | |
3001 | { | |
ac6929b5 RB |
3002 | scan_stores (insn_info->store_rec, bb_info->gen, bb_info->kill); |
3003 | scan_reads (insn_info, bb_info->gen, bb_info->kill); | |
b8698a0f | 3004 | } |
6fb5fa3c DB |
3005 | |
3006 | insn_info = insn_info->prev_insn; | |
3007 | } | |
3008 | } | |
3009 | ||
3010 | ||
3011 | /* Set the gen set of the exit block, and also any block with no | |
3012 | successors that does not have a wild read. */ | |
3013 | ||
3014 | static void | |
3015 | dse_step3_exit_block_scan (bb_info_t bb_info) | |
3016 | { | |
3017 | /* The gen set is all 0's for the exit block except for the | |
3018 | frame_pointer_group. */ | |
b8698a0f | 3019 | |
6fb5fa3c DB |
3020 | if (stores_off_frame_dead_at_return) |
3021 | { | |
3022 | unsigned int i; | |
fd6daec9 | 3023 | group_info *group; |
b8698a0f | 3024 | |
9771b263 | 3025 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
3026 | { |
3027 | if (group->process_globally && group->frame_related) | |
3028 | bitmap_ior_into (bb_info->gen, group->group_kill); | |
3029 | } | |
3030 | } | |
3031 | } | |
3032 | ||
3033 | ||
3034 | /* Find all of the blocks that are not backwards reachable from the | |
3035 | exit block or any block with no successors (BB). These are the | |
3036 | infinite loops or infinite self loops. These blocks will still | |
3037 | have their bits set in UNREACHABLE_BLOCKS. */ | |
3038 | ||
3039 | static void | |
3040 | mark_reachable_blocks (sbitmap unreachable_blocks, basic_block bb) | |
3041 | { | |
3042 | edge e; | |
3043 | edge_iterator ei; | |
3044 | ||
d7c028c0 | 3045 | if (bitmap_bit_p (unreachable_blocks, bb->index)) |
6fb5fa3c | 3046 | { |
d7c028c0 | 3047 | bitmap_clear_bit (unreachable_blocks, bb->index); |
6fb5fa3c | 3048 | FOR_EACH_EDGE (e, ei, bb->preds) |
b8698a0f | 3049 | { |
6fb5fa3c | 3050 | mark_reachable_blocks (unreachable_blocks, e->src); |
b8698a0f | 3051 | } |
6fb5fa3c DB |
3052 | } |
3053 | } | |
3054 | ||
3055 | /* Build the transfer functions for the function. */ | |
3056 | ||
3057 | static void | |
ac6929b5 | 3058 | dse_step3 () |
6fb5fa3c DB |
3059 | { |
3060 | basic_block bb; | |
6fb5fa3c DB |
3061 | sbitmap_iterator sbi; |
3062 | bitmap all_ones = NULL; | |
3063 | unsigned int i; | |
b8698a0f | 3064 | |
7ba9e72d | 3065 | auto_sbitmap unreachable_blocks (last_basic_block_for_fn (cfun)); |
f61e445a | 3066 | bitmap_ones (unreachable_blocks); |
6fb5fa3c | 3067 | |
04a90bec | 3068 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
3069 | { |
3070 | bb_info_t bb_info = bb_table[bb->index]; | |
3071 | if (bb_info->gen) | |
3072 | bitmap_clear (bb_info->gen); | |
3073 | else | |
3f9b14ff | 3074 | bb_info->gen = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3075 | |
3076 | if (bb->index == ENTRY_BLOCK) | |
3077 | ; | |
3078 | else if (bb->index == EXIT_BLOCK) | |
3079 | dse_step3_exit_block_scan (bb_info); | |
3080 | else | |
ac6929b5 | 3081 | dse_step3_scan (bb); |
6fb5fa3c DB |
3082 | if (EDGE_COUNT (bb->succs) == 0) |
3083 | mark_reachable_blocks (unreachable_blocks, bb); | |
3084 | ||
3085 | /* If this is the second time dataflow is run, delete the old | |
3086 | sets. */ | |
3087 | if (bb_info->in) | |
3088 | BITMAP_FREE (bb_info->in); | |
3089 | if (bb_info->out) | |
3090 | BITMAP_FREE (bb_info->out); | |
3091 | } | |
3092 | ||
3093 | /* For any block in an infinite loop, we must initialize the out set | |
3094 | to all ones. This could be expensive, but almost never occurs in | |
3095 | practice. However, it is common in regression tests. */ | |
d4ac4ce2 | 3096 | EXECUTE_IF_SET_IN_BITMAP (unreachable_blocks, 0, i, sbi) |
6fb5fa3c DB |
3097 | { |
3098 | if (bitmap_bit_p (all_blocks, i)) | |
3099 | { | |
3100 | bb_info_t bb_info = bb_table[i]; | |
3101 | if (!all_ones) | |
3102 | { | |
3103 | unsigned int j; | |
fd6daec9 | 3104 | group_info *group; |
6fb5fa3c | 3105 | |
3f9b14ff | 3106 | all_ones = BITMAP_ALLOC (&dse_bitmap_obstack); |
9771b263 | 3107 | FOR_EACH_VEC_ELT (rtx_group_vec, j, group) |
6fb5fa3c DB |
3108 | bitmap_ior_into (all_ones, group->group_kill); |
3109 | } | |
3110 | if (!bb_info->out) | |
3111 | { | |
3f9b14ff | 3112 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3113 | bitmap_copy (bb_info->out, all_ones); |
3114 | } | |
3115 | } | |
3116 | } | |
3117 | ||
3118 | if (all_ones) | |
3119 | BITMAP_FREE (all_ones); | |
6fb5fa3c DB |
3120 | } |
3121 | ||
3122 | ||
3123 | \f | |
3124 | /*---------------------------------------------------------------------------- | |
3125 | Fourth step. | |
3126 | ||
3127 | Solve the bitvector equations. | |
3128 | ----------------------------------------------------------------------------*/ | |
3129 | ||
3130 | ||
3131 | /* Confluence function for blocks with no successors. Create an out | |
3132 | set from the gen set of the exit block. This block logically has | |
3133 | the exit block as a successor. */ | |
3134 | ||
3135 | ||
3136 | ||
3137 | static void | |
3138 | dse_confluence_0 (basic_block bb) | |
3139 | { | |
3140 | bb_info_t bb_info = bb_table[bb->index]; | |
3141 | ||
3142 | if (bb->index == EXIT_BLOCK) | |
3143 | return; | |
3144 | ||
3145 | if (!bb_info->out) | |
3146 | { | |
3f9b14ff | 3147 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3148 | bitmap_copy (bb_info->out, bb_table[EXIT_BLOCK]->gen); |
3149 | } | |
3150 | } | |
3151 | ||
3152 | /* Propagate the information from the in set of the dest of E to the | |
3153 | out set of the src of E. If the various in or out sets are not | |
3154 | there, that means they are all ones. */ | |
3155 | ||
1a0f3fa1 | 3156 | static bool |
6fb5fa3c DB |
3157 | dse_confluence_n (edge e) |
3158 | { | |
3159 | bb_info_t src_info = bb_table[e->src->index]; | |
3160 | bb_info_t dest_info = bb_table[e->dest->index]; | |
3161 | ||
3162 | if (dest_info->in) | |
3163 | { | |
3164 | if (src_info->out) | |
3165 | bitmap_and_into (src_info->out, dest_info->in); | |
3166 | else | |
3167 | { | |
3f9b14ff | 3168 | src_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3169 | bitmap_copy (src_info->out, dest_info->in); |
3170 | } | |
3171 | } | |
1a0f3fa1 | 3172 | return true; |
6fb5fa3c DB |
3173 | } |
3174 | ||
3175 | ||
3176 | /* Propagate the info from the out to the in set of BB_INDEX's basic | |
b8698a0f | 3177 | block. There are three cases: |
6fb5fa3c DB |
3178 | |
3179 | 1) The block has no kill set. In this case the kill set is all | |
3180 | ones. It does not matter what the out set of the block is, none of | |
3181 | the info can reach the top. The only thing that reaches the top is | |
3182 | the gen set and we just copy the set. | |
3183 | ||
3184 | 2) There is a kill set but no out set and bb has successors. In | |
3185 | this case we just return. Eventually an out set will be created and | |
3186 | it is better to wait than to create a set of ones. | |
3187 | ||
3188 | 3) There is both a kill and out set. We apply the obvious transfer | |
3189 | function. | |
3190 | */ | |
3191 | ||
3192 | static bool | |
3193 | dse_transfer_function (int bb_index) | |
3194 | { | |
3195 | bb_info_t bb_info = bb_table[bb_index]; | |
3196 | ||
3197 | if (bb_info->kill) | |
3198 | { | |
3199 | if (bb_info->out) | |
3200 | { | |
3201 | /* Case 3 above. */ | |
3202 | if (bb_info->in) | |
b8698a0f | 3203 | return bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3204 | bb_info->out, bb_info->kill); |
3205 | else | |
3206 | { | |
3f9b14ff | 3207 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
b8698a0f | 3208 | bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3209 | bb_info->out, bb_info->kill); |
3210 | return true; | |
3211 | } | |
3212 | } | |
3213 | else | |
3214 | /* Case 2 above. */ | |
3215 | return false; | |
3216 | } | |
3217 | else | |
3218 | { | |
3219 | /* Case 1 above. If there is already an in set, nothing | |
3220 | happens. */ | |
3221 | if (bb_info->in) | |
3222 | return false; | |
3223 | else | |
3224 | { | |
3f9b14ff | 3225 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3226 | bitmap_copy (bb_info->in, bb_info->gen); |
3227 | return true; | |
3228 | } | |
3229 | } | |
3230 | } | |
3231 | ||
3232 | /* Solve the dataflow equations. */ | |
3233 | ||
3234 | static void | |
3235 | dse_step4 (void) | |
3236 | { | |
b8698a0f L |
3237 | df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0, |
3238 | dse_confluence_n, dse_transfer_function, | |
3239 | all_blocks, df_get_postorder (DF_BACKWARD), | |
6fb5fa3c | 3240 | df_get_n_blocks (DF_BACKWARD)); |
456610d3 | 3241 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3242 | { |
3243 | basic_block bb; | |
3244 | ||
3245 | fprintf (dump_file, "\n\n*** Global dataflow info after analysis.\n"); | |
04a90bec | 3246 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
3247 | { |
3248 | bb_info_t bb_info = bb_table[bb->index]; | |
3249 | ||
3250 | df_print_bb_index (bb, dump_file); | |
3251 | if (bb_info->in) | |
3252 | bitmap_print (dump_file, bb_info->in, " in: ", "\n"); | |
3253 | else | |
3254 | fprintf (dump_file, " in: *MISSING*\n"); | |
3255 | if (bb_info->gen) | |
3256 | bitmap_print (dump_file, bb_info->gen, " gen: ", "\n"); | |
3257 | else | |
3258 | fprintf (dump_file, " gen: *MISSING*\n"); | |
3259 | if (bb_info->kill) | |
3260 | bitmap_print (dump_file, bb_info->kill, " kill: ", "\n"); | |
3261 | else | |
3262 | fprintf (dump_file, " kill: *MISSING*\n"); | |
3263 | if (bb_info->out) | |
3264 | bitmap_print (dump_file, bb_info->out, " out: ", "\n"); | |
3265 | else | |
3266 | fprintf (dump_file, " out: *MISSING*\n\n"); | |
3267 | } | |
3268 | } | |
3269 | } | |
3270 | ||
3271 | ||
3272 | \f | |
3273 | /*---------------------------------------------------------------------------- | |
3274 | Fifth step. | |
3275 | ||
0d52bcc1 | 3276 | Delete the stores that can only be deleted using the global information. |
6fb5fa3c DB |
3277 | ----------------------------------------------------------------------------*/ |
3278 | ||
3279 | ||
3280 | static void | |
ac6929b5 | 3281 | dse_step5 (void) |
6fb5fa3c DB |
3282 | { |
3283 | basic_block bb; | |
11cd3bed | 3284 | FOR_EACH_BB_FN (bb, cfun) |
6fb5fa3c DB |
3285 | { |
3286 | bb_info_t bb_info = bb_table[bb->index]; | |
3287 | insn_info_t insn_info = bb_info->last_insn; | |
3288 | bitmap v = bb_info->out; | |
3289 | ||
3290 | while (insn_info) | |
3291 | { | |
3292 | bool deleted = false; | |
3293 | if (dump_file && insn_info->insn) | |
3294 | { | |
3295 | fprintf (dump_file, "starting to process insn %d\n", | |
3296 | INSN_UID (insn_info->insn)); | |
3297 | bitmap_print (dump_file, v, " v: ", "\n"); | |
3298 | } | |
3299 | ||
3300 | /* There may have been code deleted by the dce pass run before | |
3301 | this phase. */ | |
b8698a0f | 3302 | if (insn_info->insn |
6fb5fa3c DB |
3303 | && INSN_P (insn_info->insn) |
3304 | && (!insn_info->cannot_delete) | |
3305 | && (!bitmap_empty_p (v))) | |
3306 | { | |
fd6daec9 | 3307 | store_info *store_info = insn_info->store_rec; |
6fb5fa3c DB |
3308 | |
3309 | /* Try to delete the current insn. */ | |
3310 | deleted = true; | |
b8698a0f | 3311 | |
6fb5fa3c DB |
3312 | /* Skip the clobbers. */ |
3313 | while (!store_info->is_set) | |
3314 | store_info = store_info->next; | |
3315 | ||
ac6929b5 RB |
3316 | HOST_WIDE_INT i; |
3317 | group_info *group_info = rtx_group_vec[store_info->group_id]; | |
3318 | ||
71d6a386 RS |
3319 | HOST_WIDE_INT end = store_info->offset + store_info->width; |
3320 | for (i = store_info->offset; i < end; i++) | |
6fb5fa3c | 3321 | { |
ac6929b5 | 3322 | int index = get_bitmap_index (group_info, i); |
b8698a0f | 3323 | |
ac6929b5 RB |
3324 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3325 | fprintf (dump_file, "i = %d, index = %d\n", (int)i, index); | |
3326 | if (index == 0 || !bitmap_bit_p (v, index)) | |
6fb5fa3c | 3327 | { |
456610d3 | 3328 | if (dump_file && (dump_flags & TDF_DETAILS)) |
ac6929b5 RB |
3329 | fprintf (dump_file, "failing at i = %d\n", (int)i); |
3330 | deleted = false; | |
3331 | break; | |
6fb5fa3c DB |
3332 | } |
3333 | } | |
3334 | if (deleted) | |
3335 | { | |
9e582b1d JR |
3336 | if (dbg_cnt (dse) |
3337 | && check_for_inc_dec_1 (insn_info)) | |
6fb5fa3c | 3338 | { |
6fb5fa3c DB |
3339 | delete_insn (insn_info->insn); |
3340 | insn_info->insn = NULL; | |
3341 | globally_deleted++; | |
3342 | } | |
3343 | } | |
3344 | } | |
3345 | /* We do want to process the local info if the insn was | |
6ed3da00 | 3346 | deleted. For instance, if the insn did a wild read, we |
6fb5fa3c | 3347 | no longer need to trash the info. */ |
b8698a0f | 3348 | if (insn_info->insn |
6fb5fa3c DB |
3349 | && INSN_P (insn_info->insn) |
3350 | && (!deleted)) | |
3351 | { | |
ac6929b5 | 3352 | scan_stores (insn_info->store_rec, v, NULL); |
6fb5fa3c DB |
3353 | if (insn_info->wild_read) |
3354 | { | |
456610d3 | 3355 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3356 | fprintf (dump_file, "wild read\n"); |
3357 | bitmap_clear (v); | |
3358 | } | |
d26c7090 | 3359 | else if (insn_info->read_rec |
a8404b9a JJ |
3360 | || insn_info->non_frame_wild_read |
3361 | || insn_info->frame_read) | |
6fb5fa3c | 3362 | { |
a8404b9a JJ |
3363 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3364 | { | |
3365 | if (!insn_info->non_frame_wild_read | |
3366 | && !insn_info->frame_read) | |
3367 | fprintf (dump_file, "regular read\n"); | |
3368 | if (insn_info->non_frame_wild_read) | |
3369 | fprintf (dump_file, "non-frame wild read\n"); | |
3370 | if (insn_info->frame_read) | |
3371 | fprintf (dump_file, "frame read\n"); | |
3372 | } | |
ac6929b5 | 3373 | scan_reads (insn_info, v, NULL); |
6fb5fa3c DB |
3374 | } |
3375 | } | |
b8698a0f | 3376 | |
6fb5fa3c DB |
3377 | insn_info = insn_info->prev_insn; |
3378 | } | |
3379 | } | |
3380 | } | |
3381 | ||
3382 | ||
6fb5fa3c DB |
3383 | \f |
3384 | /*---------------------------------------------------------------------------- | |
3385 | Sixth step. | |
3386 | ||
8dd5516b JJ |
3387 | Delete stores made redundant by earlier stores (which store the same |
3388 | value) that couldn't be eliminated. | |
3389 | ----------------------------------------------------------------------------*/ | |
3390 | ||
3391 | static void | |
3392 | dse_step6 (void) | |
3393 | { | |
3394 | basic_block bb; | |
3395 | ||
04a90bec | 3396 | FOR_ALL_BB_FN (bb, cfun) |
8dd5516b JJ |
3397 | { |
3398 | bb_info_t bb_info = bb_table[bb->index]; | |
3399 | insn_info_t insn_info = bb_info->last_insn; | |
3400 | ||
3401 | while (insn_info) | |
3402 | { | |
3403 | /* There may have been code deleted by the dce pass run before | |
3404 | this phase. */ | |
3405 | if (insn_info->insn | |
3406 | && INSN_P (insn_info->insn) | |
3407 | && !insn_info->cannot_delete) | |
3408 | { | |
fd6daec9 | 3409 | store_info *s_info = insn_info->store_rec; |
8dd5516b JJ |
3410 | |
3411 | while (s_info && !s_info->is_set) | |
3412 | s_info = s_info->next; | |
3413 | if (s_info | |
3414 | && s_info->redundant_reason | |
3415 | && s_info->redundant_reason->insn | |
3416 | && INSN_P (s_info->redundant_reason->insn)) | |
3417 | { | |
eb92d49a | 3418 | rtx_insn *rinsn = s_info->redundant_reason->insn; |
456610d3 | 3419 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
3420 | fprintf (dump_file, "Locally deleting insn %d " |
3421 | "because insn %d stores the " | |
3422 | "same value and couldn't be " | |
3423 | "eliminated\n", | |
3424 | INSN_UID (insn_info->insn), | |
3425 | INSN_UID (rinsn)); | |
3426 | delete_dead_store_insn (insn_info); | |
3427 | } | |
3428 | } | |
3429 | insn_info = insn_info->prev_insn; | |
3430 | } | |
3431 | } | |
3432 | } | |
3433 | \f | |
3434 | /*---------------------------------------------------------------------------- | |
3435 | Seventh step. | |
3436 | ||
b8698a0f | 3437 | Destroy everything left standing. |
6fb5fa3c DB |
3438 | ----------------------------------------------------------------------------*/ |
3439 | ||
b8698a0f | 3440 | static void |
3f9b14ff | 3441 | dse_step7 (void) |
6fb5fa3c | 3442 | { |
3f9b14ff SB |
3443 | bitmap_obstack_release (&dse_bitmap_obstack); |
3444 | obstack_free (&dse_obstack, NULL); | |
370f38e8 | 3445 | |
6fb5fa3c DB |
3446 | end_alias_analysis (); |
3447 | free (bb_table); | |
c203e8a7 TS |
3448 | delete rtx_group_table; |
3449 | rtx_group_table = NULL; | |
9771b263 | 3450 | rtx_group_vec.release (); |
6fb5fa3c DB |
3451 | BITMAP_FREE (all_blocks); |
3452 | BITMAP_FREE (scratch); | |
3453 | ||
da6603c6 | 3454 | rtx_store_info_pool.release (); |
fb0b2914 ML |
3455 | read_info_type_pool.release (); |
3456 | insn_info_type_pool.release (); | |
3457 | dse_bb_info_type_pool.release (); | |
3458 | group_info_pool.release (); | |
3459 | deferred_change_pool.release (); | |
6fb5fa3c DB |
3460 | } |
3461 | ||
3462 | ||
6fb5fa3c DB |
3463 | /* ------------------------------------------------------------------------- |
3464 | DSE | |
3465 | ------------------------------------------------------------------------- */ | |
3466 | ||
3467 | /* Callback for running pass_rtl_dse. */ | |
3468 | ||
3469 | static unsigned int | |
3470 | rest_of_handle_dse (void) | |
3471 | { | |
6fb5fa3c DB |
3472 | df_set_flags (DF_DEFER_INSN_RESCAN); |
3473 | ||
02b47899 KZ |
3474 | /* Need the notes since we must track live hardregs in the forwards |
3475 | direction. */ | |
3476 | df_note_add_problem (); | |
3477 | df_analyze (); | |
3478 | ||
6fb5fa3c DB |
3479 | dse_step0 (); |
3480 | dse_step1 (); | |
3481 | dse_step2_init (); | |
ac6929b5 | 3482 | if (dse_step2 ()) |
6fb5fa3c DB |
3483 | { |
3484 | df_set_flags (DF_LR_RUN_DCE); | |
3485 | df_analyze (); | |
456610d3 | 3486 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 3487 | fprintf (dump_file, "doing global processing\n"); |
ac6929b5 | 3488 | dse_step3 (); |
6fb5fa3c | 3489 | dse_step4 (); |
ac6929b5 | 3490 | dse_step5 (); |
6fb5fa3c DB |
3491 | } |
3492 | ||
8dd5516b | 3493 | dse_step6 (); |
3f9b14ff | 3494 | dse_step7 (); |
6fb5fa3c DB |
3495 | |
3496 | if (dump_file) | |
ac6929b5 RB |
3497 | fprintf (dump_file, "dse: local deletions = %d, global deletions = %d\n", |
3498 | locally_deleted, globally_deleted); | |
6c5ed3f1 JJ |
3499 | |
3500 | /* DSE can eliminate potentially-trapping MEMs. | |
3501 | Remove any EH edges associated with them. */ | |
3502 | if ((locally_deleted || globally_deleted) | |
3503 | && cfun->can_throw_non_call_exceptions | |
3504 | && purge_all_dead_edges ()) | |
3505 | cleanup_cfg (0); | |
3506 | ||
6fb5fa3c DB |
3507 | return 0; |
3508 | } | |
3509 | ||
17795822 TS |
3510 | namespace { |
3511 | ||
3512 | const pass_data pass_data_rtl_dse1 = | |
27a4cd48 DM |
3513 | { |
3514 | RTL_PASS, /* type */ | |
3515 | "dse1", /* name */ | |
3516 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3517 | TV_DSE1, /* tv_id */ |
3518 | 0, /* properties_required */ | |
3519 | 0, /* properties_provided */ | |
3520 | 0, /* properties_destroyed */ | |
3521 | 0, /* todo_flags_start */ | |
3bea341f | 3522 | TODO_df_finish, /* todo_flags_finish */ |
6fb5fa3c DB |
3523 | }; |
3524 | ||
17795822 | 3525 | class pass_rtl_dse1 : public rtl_opt_pass |
27a4cd48 DM |
3526 | { |
3527 | public: | |
c3284718 RS |
3528 | pass_rtl_dse1 (gcc::context *ctxt) |
3529 | : rtl_opt_pass (pass_data_rtl_dse1, ctxt) | |
27a4cd48 DM |
3530 | {} |
3531 | ||
3532 | /* opt_pass methods: */ | |
1a3d085c TS |
3533 | virtual bool gate (function *) |
3534 | { | |
3535 | return optimize > 0 && flag_dse && dbg_cnt (dse1); | |
3536 | } | |
3537 | ||
be55bfe6 | 3538 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
27a4cd48 DM |
3539 | |
3540 | }; // class pass_rtl_dse1 | |
3541 | ||
17795822 TS |
3542 | } // anon namespace |
3543 | ||
27a4cd48 DM |
3544 | rtl_opt_pass * |
3545 | make_pass_rtl_dse1 (gcc::context *ctxt) | |
3546 | { | |
3547 | return new pass_rtl_dse1 (ctxt); | |
3548 | } | |
3549 | ||
17795822 TS |
3550 | namespace { |
3551 | ||
3552 | const pass_data pass_data_rtl_dse2 = | |
27a4cd48 DM |
3553 | { |
3554 | RTL_PASS, /* type */ | |
3555 | "dse2", /* name */ | |
3556 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3557 | TV_DSE2, /* tv_id */ |
3558 | 0, /* properties_required */ | |
3559 | 0, /* properties_provided */ | |
3560 | 0, /* properties_destroyed */ | |
3561 | 0, /* todo_flags_start */ | |
3bea341f | 3562 | TODO_df_finish, /* todo_flags_finish */ |
6fb5fa3c | 3563 | }; |
27a4cd48 | 3564 | |
17795822 | 3565 | class pass_rtl_dse2 : public rtl_opt_pass |
27a4cd48 DM |
3566 | { |
3567 | public: | |
c3284718 RS |
3568 | pass_rtl_dse2 (gcc::context *ctxt) |
3569 | : rtl_opt_pass (pass_data_rtl_dse2, ctxt) | |
27a4cd48 DM |
3570 | {} |
3571 | ||
3572 | /* opt_pass methods: */ | |
1a3d085c TS |
3573 | virtual bool gate (function *) |
3574 | { | |
3575 | return optimize > 0 && flag_dse && dbg_cnt (dse2); | |
3576 | } | |
3577 | ||
be55bfe6 | 3578 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
27a4cd48 DM |
3579 | |
3580 | }; // class pass_rtl_dse2 | |
3581 | ||
17795822 TS |
3582 | } // anon namespace |
3583 | ||
27a4cd48 DM |
3584 | rtl_opt_pass * |
3585 | make_pass_rtl_dse2 (gcc::context *ctxt) | |
3586 | { | |
3587 | return new pass_rtl_dse2 (ctxt); | |
3588 | } |