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6fb5fa3c | 1 | /* RTL dead store elimination. |
818ab71a | 2 | Copyright (C) 2005-2016 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" |
957060b5 AM |
35 | #include "tm_p.h" |
36 | #include "gimple-ssa.h" | |
37 | #include "expmed.h" | |
38 | #include "optabs.h" | |
957060b5 AM |
39 | #include "emit-rtl.h" |
40 | #include "recog.h" | |
40e23961 | 41 | #include "alias.h" |
d8a2d370 | 42 | #include "stor-layout.h" |
60393bbc | 43 | #include "cfgrtl.h" |
6fb5fa3c | 44 | #include "cselib.h" |
6fb5fa3c | 45 | #include "tree-pass.h" |
36566b39 | 46 | #include "explow.h" |
6fb5fa3c | 47 | #include "expr.h" |
6fb5fa3c | 48 | #include "dbgcnt.h" |
dabd47e7 | 49 | #include "params.h" |
d7111da8 | 50 | #include "rtl-iter.h" |
6c5ed3f1 | 51 | #include "cfgcleanup.h" |
6fb5fa3c DB |
52 | |
53 | /* This file contains three techniques for performing Dead Store | |
b8698a0f | 54 | Elimination (dse). |
6fb5fa3c DB |
55 | |
56 | * The first technique performs dse locally on any base address. It | |
57 | is based on the cselib which is a local value numbering technique. | |
58 | This technique is local to a basic block but deals with a fairly | |
59 | general addresses. | |
b8698a0f | 60 | |
6fb5fa3c DB |
61 | * The second technique performs dse globally but is restricted to |
62 | base addresses that are either constant or are relative to the | |
63 | frame_pointer. | |
64 | ||
65 | * The third technique, (which is only done after register allocation) | |
026c3cfd | 66 | processes the spill slots. This differs from the second |
6fb5fa3c DB |
67 | technique because it takes advantage of the fact that spilling is |
68 | completely free from the effects of aliasing. | |
69 | ||
70 | Logically, dse is a backwards dataflow problem. A store can be | |
71 | deleted if it if cannot be reached in the backward direction by any | |
72 | use of the value being stored. However, the local technique uses a | |
73 | forwards scan of the basic block because cselib requires that the | |
74 | block be processed in that order. | |
75 | ||
76 | The pass is logically broken into 7 steps: | |
77 | ||
78 | 0) Initialization. | |
79 | ||
80 | 1) The local algorithm, as well as scanning the insns for the two | |
81 | global algorithms. | |
82 | ||
83 | 2) Analysis to see if the global algs are necessary. In the case | |
84 | of stores base on a constant address, there must be at least two | |
85 | stores to that address, to make it possible to delete some of the | |
86 | stores. In the case of stores off of the frame or spill related | |
87 | stores, only one store to an address is necessary because those | |
88 | stores die at the end of the function. | |
89 | ||
b8698a0f | 90 | 3) Set up the global dataflow equations based on processing the |
6fb5fa3c DB |
91 | info parsed in the first step. |
92 | ||
93 | 4) Solve the dataflow equations. | |
94 | ||
95 | 5) Delete the insns that the global analysis has indicated are | |
96 | unnecessary. | |
97 | ||
073a8998 | 98 | 6) Delete insns that store the same value as preceding store |
8dd5516b JJ |
99 | where the earlier store couldn't be eliminated. |
100 | ||
101 | 7) Cleanup. | |
6fb5fa3c DB |
102 | |
103 | This step uses cselib and canon_rtx to build the largest expression | |
104 | possible for each address. This pass is a forwards pass through | |
105 | each basic block. From the point of view of the global technique, | |
106 | the first pass could examine a block in either direction. The | |
0d52bcc1 | 107 | forwards ordering is to accommodate cselib. |
6fb5fa3c | 108 | |
5ef0b50d | 109 | We make a simplifying assumption: addresses fall into four broad |
6fb5fa3c DB |
110 | categories: |
111 | ||
112 | 1) base has rtx_varies_p == false, offset is constant. | |
113 | 2) base has rtx_varies_p == false, offset variable. | |
114 | 3) base has rtx_varies_p == true, offset constant. | |
115 | 4) base has rtx_varies_p == true, offset variable. | |
116 | ||
117 | The local passes are able to process all 4 kinds of addresses. The | |
5ef0b50d | 118 | global pass only handles 1). |
6fb5fa3c DB |
119 | |
120 | The global problem is formulated as follows: | |
121 | ||
122 | A store, S1, to address A, where A is not relative to the stack | |
123 | frame, can be eliminated if all paths from S1 to the end of the | |
5ef0b50d | 124 | function contain another store to A before a read to A. |
6fb5fa3c DB |
125 | |
126 | If the address A is relative to the stack frame, a store S2 to A | |
5ef0b50d | 127 | can be eliminated if there are no paths from S2 that reach the |
6fb5fa3c | 128 | end of the function that read A before another store to A. In |
5ef0b50d | 129 | this case S2 can be deleted if there are paths from S2 to the |
6fb5fa3c DB |
130 | end of the function that have no reads or writes to A. This |
131 | second case allows stores to the stack frame to be deleted that | |
132 | would otherwise die when the function returns. This cannot be | |
133 | done if stores_off_frame_dead_at_return is not true. See the doc | |
134 | for that variable for when this variable is false. | |
135 | ||
136 | The global problem is formulated as a backwards set union | |
137 | dataflow problem where the stores are the gens and reads are the | |
138 | kills. Set union problems are rare and require some special | |
139 | handling given our representation of bitmaps. A straightforward | |
5ef0b50d | 140 | implementation requires a lot of bitmaps filled with 1s. |
6fb5fa3c DB |
141 | These are expensive and cumbersome in our bitmap formulation so |
142 | care has been taken to avoid large vectors filled with 1s. See | |
143 | the comments in bb_info and in the dataflow confluence functions | |
b8698a0f | 144 | for details. |
6fb5fa3c DB |
145 | |
146 | There are two places for further enhancements to this algorithm: | |
b8698a0f | 147 | |
6fb5fa3c DB |
148 | 1) The original dse which was embedded in a pass called flow also |
149 | did local address forwarding. For example in | |
150 | ||
151 | A <- r100 | |
152 | ... <- A | |
153 | ||
154 | flow would replace the right hand side of the second insn with a | |
6ed3da00 | 155 | reference to r100. Most of the information is available to add this |
6fb5fa3c DB |
156 | to this pass. It has not done it because it is a lot of work in |
157 | the case that either r100 is assigned to between the first and | |
158 | second insn and/or the second insn is a load of part of the value | |
159 | stored by the first insn. | |
160 | ||
161 | insn 5 in gcc.c-torture/compile/990203-1.c simple case. | |
162 | insn 15 in gcc.c-torture/execute/20001017-2.c simple case. | |
163 | insn 25 in gcc.c-torture/execute/20001026-1.c simple case. | |
164 | insn 44 in gcc.c-torture/execute/20010910-1.c simple case. | |
165 | ||
166 | 2) The cleaning up of spill code is quite profitable. It currently | |
167 | depends on reading tea leaves and chicken entrails left by reload. | |
168 | This pass depends on reload creating a singleton alias set for each | |
169 | spill slot and telling the next dse pass which of these alias sets | |
170 | are the singletons. Rather than analyze the addresses of the | |
171 | spills, dse's spill processing just does analysis of the loads and | |
172 | stores that use those alias sets. There are three cases where this | |
173 | falls short: | |
174 | ||
175 | a) Reload sometimes creates the slot for one mode of access, and | |
176 | then inserts loads and/or stores for a smaller mode. In this | |
177 | case, the current code just punts on the slot. The proper thing | |
178 | to do is to back out and use one bit vector position for each | |
179 | byte of the entity associated with the slot. This depends on | |
180 | KNOWING that reload always generates the accesses for each of the | |
181 | bytes in some canonical (read that easy to understand several | |
182 | passes after reload happens) way. | |
183 | ||
184 | b) Reload sometimes decides that spill slot it allocated was not | |
185 | large enough for the mode and goes back and allocates more slots | |
186 | with the same mode and alias set. The backout in this case is a | |
187 | little more graceful than (a). In this case the slot is unmarked | |
188 | as being a spill slot and if final address comes out to be based | |
b8698a0f | 189 | off the frame pointer, the global algorithm handles this slot. |
6fb5fa3c DB |
190 | |
191 | c) For any pass that may prespill, there is currently no | |
192 | mechanism to tell the dse pass that the slot being used has the | |
193 | special properties that reload uses. It may be that all that is | |
0d52bcc1 | 194 | required is to have those passes make the same calls that reload |
6fb5fa3c DB |
195 | does, assuming that the alias sets can be manipulated in the same |
196 | way. */ | |
197 | ||
198 | /* There are limits to the size of constant offsets we model for the | |
199 | global problem. There are certainly test cases, that exceed this | |
200 | limit, however, it is unlikely that there are important programs | |
201 | that really have constant offsets this size. */ | |
202 | #define MAX_OFFSET (64 * 1024) | |
203 | ||
3f9b14ff SB |
204 | /* Obstack for the DSE dataflow bitmaps. We don't want to put these |
205 | on the default obstack because these bitmaps can grow quite large | |
206 | (~2GB for the small (!) test case of PR54146) and we'll hold on to | |
207 | all that memory until the end of the compiler run. | |
208 | As a bonus, delete_tree_live_info can destroy all the bitmaps by just | |
209 | releasing the whole obstack. */ | |
210 | static bitmap_obstack dse_bitmap_obstack; | |
211 | ||
212 | /* Obstack for other data. As for above: Kinda nice to be able to | |
213 | throw it all away at the end in one big sweep. */ | |
214 | static struct obstack dse_obstack; | |
215 | ||
216 | /* Scratch bitmap for cselib's cselib_expand_value_rtx. */ | |
6fb5fa3c | 217 | static bitmap scratch = NULL; |
3f9b14ff | 218 | |
da6603c6 | 219 | struct insn_info_type; |
6fb5fa3c DB |
220 | |
221 | /* This structure holds information about a candidate store. */ | |
b8698a0f | 222 | struct store_info |
6fb5fa3c DB |
223 | { |
224 | ||
225 | /* False means this is a clobber. */ | |
226 | bool is_set; | |
227 | ||
8dd5516b JJ |
228 | /* False if a single HOST_WIDE_INT bitmap is used for positions_needed. */ |
229 | bool is_large; | |
230 | ||
6fb5fa3c DB |
231 | /* The id of the mem group of the base address. If rtx_varies_p is |
232 | true, this is -1. Otherwise, it is the index into the group | |
233 | table. */ | |
234 | int group_id; | |
b8698a0f | 235 | |
6fb5fa3c DB |
236 | /* This is the cselib value. */ |
237 | cselib_val *cse_base; | |
238 | ||
239 | /* This canonized mem. */ | |
240 | rtx mem; | |
241 | ||
6216f94e | 242 | /* Canonized MEM address for use by canon_true_dependence. */ |
6fb5fa3c DB |
243 | rtx mem_addr; |
244 | ||
6fb5fa3c DB |
245 | /* The offset of the first and byte before the last byte associated |
246 | with the operation. */ | |
8dd5516b JJ |
247 | HOST_WIDE_INT begin, end; |
248 | ||
249 | union | |
250 | { | |
251 | /* A bitmask as wide as the number of bytes in the word that | |
252 | contains a 1 if the byte may be needed. The store is unused if | |
253 | all of the bits are 0. This is used if IS_LARGE is false. */ | |
254 | unsigned HOST_WIDE_INT small_bitmask; | |
255 | ||
256 | struct | |
257 | { | |
258 | /* A bitmap with one bit per byte. Cleared bit means the position | |
259 | is needed. Used if IS_LARGE is false. */ | |
dc491a25 | 260 | bitmap bmap; |
6fb5fa3c | 261 | |
8dd5516b JJ |
262 | /* Number of set bits (i.e. unneeded bytes) in BITMAP. If it is |
263 | equal to END - BEGIN, the whole store is unused. */ | |
264 | int count; | |
265 | } large; | |
266 | } positions_needed; | |
6fb5fa3c DB |
267 | |
268 | /* The next store info for this insn. */ | |
269 | struct store_info *next; | |
270 | ||
271 | /* The right hand side of the store. This is used if there is a | |
272 | subsequent reload of the mems address somewhere later in the | |
273 | basic block. */ | |
8dd5516b JJ |
274 | rtx rhs; |
275 | ||
276 | /* If rhs is or holds a constant, this contains that constant, | |
277 | otherwise NULL. */ | |
278 | rtx const_rhs; | |
279 | ||
280 | /* Set if this store stores the same constant value as REDUNDANT_REASON | |
281 | insn stored. These aren't eliminated early, because doing that | |
282 | might prevent the earlier larger store to be eliminated. */ | |
da6603c6 | 283 | struct insn_info_type *redundant_reason; |
6fb5fa3c DB |
284 | }; |
285 | ||
4fe663b0 L |
286 | /* Return a bitmask with the first N low bits set. */ |
287 | ||
288 | static unsigned HOST_WIDE_INT | |
289 | lowpart_bitmask (int n) | |
290 | { | |
dd4786fe | 291 | unsigned HOST_WIDE_INT mask = HOST_WIDE_INT_M1U; |
4fe663b0 L |
292 | return mask >> (HOST_BITS_PER_WIDE_INT - n); |
293 | } | |
294 | ||
fcb87c50 | 295 | static object_allocator<store_info> cse_store_info_pool ("cse_store_info_pool"); |
da6603c6 | 296 | |
fcb87c50 | 297 | static object_allocator<store_info> rtx_store_info_pool ("rtx_store_info_pool"); |
6fb5fa3c DB |
298 | |
299 | /* This structure holds information about a load. These are only | |
300 | built for rtx bases. */ | |
da6603c6 | 301 | struct read_info_type |
6fb5fa3c DB |
302 | { |
303 | /* The id of the mem group of the base address. */ | |
304 | int group_id; | |
305 | ||
6fb5fa3c DB |
306 | /* The offset of the first and byte after the last byte associated |
307 | with the operation. If begin == end == 0, the read did not have | |
308 | a constant offset. */ | |
309 | int begin, end; | |
310 | ||
311 | /* The mem being read. */ | |
312 | rtx mem; | |
313 | ||
314 | /* The next read_info for this insn. */ | |
da6603c6 | 315 | struct read_info_type *next; |
6fb5fa3c | 316 | }; |
da6603c6 | 317 | typedef struct read_info_type *read_info_t; |
6fb5fa3c | 318 | |
fcb87c50 | 319 | static object_allocator<read_info_type> read_info_type_pool ("read_info_pool"); |
6fb5fa3c DB |
320 | |
321 | /* One of these records is created for each insn. */ | |
322 | ||
da6603c6 | 323 | struct insn_info_type |
6fb5fa3c DB |
324 | { |
325 | /* Set true if the insn contains a store but the insn itself cannot | |
326 | be deleted. This is set if the insn is a parallel and there is | |
327 | more than one non dead output or if the insn is in some way | |
328 | volatile. */ | |
329 | bool cannot_delete; | |
330 | ||
331 | /* This field is only used by the global algorithm. It is set true | |
332 | if the insn contains any read of mem except for a (1). This is | |
333 | also set if the insn is a call or has a clobber mem. If the insn | |
334 | contains a wild read, the use_rec will be null. */ | |
335 | bool wild_read; | |
336 | ||
d26c7090 ER |
337 | /* This is true only for CALL instructions which could potentially read |
338 | any non-frame memory location. This field is used by the global | |
339 | algorithm. */ | |
340 | bool non_frame_wild_read; | |
341 | ||
50f0f366 EB |
342 | /* This field is only used for the processing of const functions. |
343 | These functions cannot read memory, but they can read the stack | |
64520bdc EB |
344 | because that is where they may get their parms. We need to be |
345 | this conservative because, like the store motion pass, we don't | |
346 | consider CALL_INSN_FUNCTION_USAGE when processing call insns. | |
347 | Moreover, we need to distinguish two cases: | |
348 | 1. Before reload (register elimination), the stores related to | |
349 | outgoing arguments are stack pointer based and thus deemed | |
350 | of non-constant base in this pass. This requires special | |
351 | handling but also means that the frame pointer based stores | |
352 | need not be killed upon encountering a const function call. | |
353 | 2. After reload, the stores related to outgoing arguments can be | |
354 | either stack pointer or hard frame pointer based. This means | |
355 | that we have no other choice than also killing all the frame | |
356 | pointer based stores upon encountering a const function call. | |
57534689 JJ |
357 | This field is set after reload for const function calls and before |
358 | reload for const tail function calls on targets where arg pointer | |
359 | is the frame pointer. Having this set is less severe than a wild | |
360 | read, it just means that all the frame related stores are killed | |
361 | rather than all the stores. */ | |
64520bdc EB |
362 | bool frame_read; |
363 | ||
364 | /* This field is only used for the processing of const functions. | |
365 | It is set if the insn may contain a stack pointer based store. */ | |
50f0f366 | 366 | bool stack_pointer_based; |
6fb5fa3c DB |
367 | |
368 | /* This is true if any of the sets within the store contains a | |
369 | cselib base. Such stores can only be deleted by the local | |
370 | algorithm. */ | |
371 | bool contains_cselib_groups; | |
372 | ||
373 | /* The insn. */ | |
dd60a84c | 374 | rtx_insn *insn; |
6fb5fa3c DB |
375 | |
376 | /* The list of mem sets or mem clobbers that are contained in this | |
377 | insn. If the insn is deletable, it contains only one mem set. | |
378 | But it could also contain clobbers. Insns that contain more than | |
379 | one mem set are not deletable, but each of those mems are here in | |
6ed3da00 | 380 | order to provide info to delete other insns. */ |
fd6daec9 | 381 | store_info *store_rec; |
6fb5fa3c DB |
382 | |
383 | /* The linked list of mem uses in this insn. Only the reads from | |
384 | rtx bases are listed here. The reads to cselib bases are | |
385 | completely processed during the first scan and so are never | |
386 | created. */ | |
387 | read_info_t read_rec; | |
388 | ||
9e582b1d JR |
389 | /* The live fixed registers. We assume only fixed registers can |
390 | cause trouble by being clobbered from an expanded pattern; | |
391 | storing only the live fixed registers (rather than all registers) | |
392 | means less memory needs to be allocated / copied for the individual | |
393 | stores. */ | |
394 | regset fixed_regs_live; | |
395 | ||
6fb5fa3c | 396 | /* The prev insn in the basic block. */ |
da6603c6 | 397 | struct insn_info_type * prev_insn; |
6fb5fa3c DB |
398 | |
399 | /* The linked list of insns that are in consideration for removal in | |
073a8998 | 400 | the forwards pass through the basic block. This pointer may be |
6fb5fa3c | 401 | trash as it is not cleared when a wild read occurs. The only |
fa10beec | 402 | time it is guaranteed to be correct is when the traversal starts |
6fb5fa3c | 403 | at active_local_stores. */ |
da6603c6 | 404 | struct insn_info_type * next_local_store; |
6fb5fa3c | 405 | }; |
da6603c6 | 406 | typedef struct insn_info_type *insn_info_t; |
6fb5fa3c | 407 | |
fcb87c50 | 408 | static object_allocator<insn_info_type> insn_info_type_pool ("insn_info_pool"); |
6fb5fa3c DB |
409 | |
410 | /* The linked list of stores that are under consideration in this | |
b8698a0f | 411 | basic block. */ |
6fb5fa3c | 412 | static insn_info_t active_local_stores; |
dabd47e7 | 413 | static int active_local_stores_len; |
6fb5fa3c | 414 | |
da6603c6 | 415 | struct dse_bb_info_type |
6fb5fa3c | 416 | { |
6fb5fa3c DB |
417 | /* Pointer to the insn info for the last insn in the block. These |
418 | are linked so this is how all of the insns are reached. During | |
419 | scanning this is the current insn being scanned. */ | |
420 | insn_info_t last_insn; | |
421 | ||
422 | /* The info for the global dataflow problem. */ | |
423 | ||
424 | ||
425 | /* This is set if the transfer function should and in the wild_read | |
426 | bitmap before applying the kill and gen sets. That vector knocks | |
427 | out most of the bits in the bitmap and thus speeds up the | |
428 | operations. */ | |
429 | bool apply_wild_read; | |
430 | ||
02b47899 KZ |
431 | /* The following 4 bitvectors hold information about which positions |
432 | of which stores are live or dead. They are indexed by | |
433 | get_bitmap_index. */ | |
434 | ||
6fb5fa3c DB |
435 | /* The set of store positions that exist in this block before a wild read. */ |
436 | bitmap gen; | |
b8698a0f | 437 | |
6fb5fa3c DB |
438 | /* The set of load positions that exist in this block above the |
439 | same position of a store. */ | |
440 | bitmap kill; | |
441 | ||
442 | /* The set of stores that reach the top of the block without being | |
443 | killed by a read. | |
444 | ||
445 | Do not represent the in if it is all ones. Note that this is | |
446 | what the bitvector should logically be initialized to for a set | |
447 | intersection problem. However, like the kill set, this is too | |
448 | expensive. So initially, the in set will only be created for the | |
449 | exit block and any block that contains a wild read. */ | |
450 | bitmap in; | |
451 | ||
452 | /* The set of stores that reach the bottom of the block from it's | |
453 | successors. | |
454 | ||
455 | Do not represent the in if it is all ones. Note that this is | |
456 | what the bitvector should logically be initialized to for a set | |
457 | intersection problem. However, like the kill and in set, this is | |
458 | too expensive. So what is done is that the confluence operator | |
459 | just initializes the vector from one of the out sets of the | |
460 | successors of the block. */ | |
461 | bitmap out; | |
02b47899 KZ |
462 | |
463 | /* The following bitvector is indexed by the reg number. It | |
464 | contains the set of regs that are live at the current instruction | |
465 | being processed. While it contains info for all of the | |
9e582b1d JR |
466 | registers, only the hard registers are actually examined. It is used |
467 | to assure that shift and/or add sequences that are inserted do not | |
073a8998 | 468 | accidentally clobber live hard regs. */ |
02b47899 | 469 | bitmap regs_live; |
6fb5fa3c DB |
470 | }; |
471 | ||
da6603c6 | 472 | typedef struct dse_bb_info_type *bb_info_t; |
fb0b2914 ML |
473 | |
474 | static object_allocator<dse_bb_info_type> dse_bb_info_type_pool | |
fcb87c50 | 475 | ("bb_info_pool"); |
6fb5fa3c DB |
476 | |
477 | /* Table to hold all bb_infos. */ | |
478 | static bb_info_t *bb_table; | |
479 | ||
480 | /* There is a group_info for each rtx base that is used to reference | |
481 | memory. There are also not many of the rtx bases because they are | |
482 | very limited in scope. */ | |
483 | ||
b8698a0f | 484 | struct group_info |
6fb5fa3c DB |
485 | { |
486 | /* The actual base of the address. */ | |
487 | rtx rtx_base; | |
488 | ||
489 | /* The sequential id of the base. This allows us to have a | |
490 | canonical ordering of these that is not based on addresses. */ | |
491 | int id; | |
492 | ||
8f5929e1 JJ |
493 | /* True if there are any positions that are to be processed |
494 | globally. */ | |
495 | bool process_globally; | |
496 | ||
497 | /* True if the base of this group is either the frame_pointer or | |
498 | hard_frame_pointer. */ | |
499 | bool frame_related; | |
500 | ||
d32f725a OH |
501 | /* A mem wrapped around the base pointer for the group in order to do |
502 | read dependency. It must be given BLKmode in order to encompass all | |
503 | the possible offsets from the base. */ | |
6fb5fa3c | 504 | rtx base_mem; |
b8698a0f | 505 | |
6216f94e JJ |
506 | /* Canonized version of base_mem's address. */ |
507 | rtx canon_base_addr; | |
6fb5fa3c DB |
508 | |
509 | /* These two sets of two bitmaps are used to keep track of how many | |
6ed3da00 | 510 | stores are actually referencing that position from this base. We |
6fb5fa3c | 511 | only do this for rtx bases as this will be used to assign |
6ed3da00 | 512 | positions in the bitmaps for the global problem. Bit N is set in |
6fb5fa3c DB |
513 | store1 on the first store for offset N. Bit N is set in store2 |
514 | for the second store to offset N. This is all we need since we | |
515 | only care about offsets that have two or more stores for them. | |
516 | ||
517 | The "_n" suffix is for offsets less than 0 and the "_p" suffix is | |
518 | for 0 and greater offsets. | |
519 | ||
520 | There is one special case here, for stores into the stack frame, | |
521 | we will or store1 into store2 before deciding which stores look | |
522 | at globally. This is because stores to the stack frame that have | |
523 | no other reads before the end of the function can also be | |
524 | deleted. */ | |
525 | bitmap store1_n, store1_p, store2_n, store2_p; | |
526 | ||
d26c7090 ER |
527 | /* These bitmaps keep track of offsets in this group escape this function. |
528 | An offset escapes if it corresponds to a named variable whose | |
529 | addressable flag is set. */ | |
530 | bitmap escaped_n, escaped_p; | |
531 | ||
6ed3da00 | 532 | /* The positions in this bitmap have the same assignments as the in, |
6fb5fa3c | 533 | out, gen and kill bitmaps. This bitmap is all zeros except for |
6ed3da00 | 534 | the positions that are occupied by stores for this group. */ |
6fb5fa3c DB |
535 | bitmap group_kill; |
536 | ||
6fb5fa3c | 537 | /* The offset_map is used to map the offsets from this base into |
6ed3da00 | 538 | positions in the global bitmaps. It is only created after all of |
6fb5fa3c DB |
539 | the all of stores have been scanned and we know which ones we |
540 | care about. */ | |
b8698a0f L |
541 | int *offset_map_n, *offset_map_p; |
542 | int offset_map_size_n, offset_map_size_p; | |
6fb5fa3c | 543 | }; |
da6603c6 | 544 | |
fcb87c50 | 545 | static object_allocator<group_info> group_info_pool ("rtx_group_info_pool"); |
6fb5fa3c | 546 | |
6fb5fa3c DB |
547 | /* Index into the rtx_group_vec. */ |
548 | static int rtx_group_next_id; | |
549 | ||
6fb5fa3c | 550 | |
fd6daec9 | 551 | static vec<group_info *> rtx_group_vec; |
6fb5fa3c DB |
552 | |
553 | ||
554 | /* This structure holds the set of changes that are being deferred | |
555 | when removing read operation. See replace_read. */ | |
b8698a0f | 556 | struct deferred_change |
6fb5fa3c DB |
557 | { |
558 | ||
559 | /* The mem that is being replaced. */ | |
560 | rtx *loc; | |
561 | ||
562 | /* The reg it is being replaced with. */ | |
563 | rtx reg; | |
564 | ||
565 | struct deferred_change *next; | |
566 | }; | |
567 | ||
fb0b2914 | 568 | static object_allocator<deferred_change> deferred_change_pool |
fcb87c50 | 569 | ("deferred_change_pool"); |
6fb5fa3c | 570 | |
fd6daec9 | 571 | static deferred_change *deferred_change_list = NULL; |
6fb5fa3c | 572 | |
e3b5732b | 573 | /* This is true except if cfun->stdarg -- i.e. we cannot do |
9dd9bf80 | 574 | this for vararg functions because they play games with the frame. */ |
6fb5fa3c DB |
575 | static bool stores_off_frame_dead_at_return; |
576 | ||
577 | /* Counter for stats. */ | |
b8698a0f L |
578 | static int globally_deleted; |
579 | static int locally_deleted; | |
b8698a0f | 580 | |
6fb5fa3c DB |
581 | static bitmap all_blocks; |
582 | ||
d26c7090 ER |
583 | /* Locations that are killed by calls in the global phase. */ |
584 | static bitmap kill_on_calls; | |
585 | ||
6fb5fa3c DB |
586 | /* The number of bits used in the global bitmaps. */ |
587 | static unsigned int current_position; | |
6fb5fa3c DB |
588 | \f |
589 | /*---------------------------------------------------------------------------- | |
590 | Zeroth step. | |
591 | ||
b8698a0f | 592 | Initialization. |
6fb5fa3c DB |
593 | ----------------------------------------------------------------------------*/ |
594 | ||
6fb5fa3c | 595 | |
6fb5fa3c DB |
596 | /* Hashtable callbacks for maintaining the "bases" field of |
597 | store_group_info, given that the addresses are function invariants. */ | |
598 | ||
8d67ee55 | 599 | struct invariant_group_base_hasher : nofree_ptr_hash <group_info> |
703c8606 | 600 | { |
67f58944 TS |
601 | static inline hashval_t hash (const group_info *); |
602 | static inline bool equal (const group_info *, const group_info *); | |
703c8606 LC |
603 | }; |
604 | ||
605 | inline bool | |
67f58944 TS |
606 | invariant_group_base_hasher::equal (const group_info *gi1, |
607 | const group_info *gi2) | |
6fb5fa3c | 608 | { |
6fb5fa3c DB |
609 | return rtx_equal_p (gi1->rtx_base, gi2->rtx_base); |
610 | } | |
611 | ||
703c8606 | 612 | inline hashval_t |
67f58944 | 613 | invariant_group_base_hasher::hash (const group_info *gi) |
6fb5fa3c | 614 | { |
6fb5fa3c DB |
615 | int do_not_record; |
616 | return hash_rtx (gi->rtx_base, Pmode, &do_not_record, NULL, false); | |
617 | } | |
618 | ||
703c8606 | 619 | /* Tables of group_info structures, hashed by base value. */ |
c203e8a7 | 620 | static hash_table<invariant_group_base_hasher> *rtx_group_table; |
703c8606 | 621 | |
6fb5fa3c DB |
622 | |
623 | /* Get the GROUP for BASE. Add a new group if it is not there. */ | |
624 | ||
fd6daec9 | 625 | static group_info * |
6fb5fa3c DB |
626 | get_group_info (rtx base) |
627 | { | |
b8698a0f | 628 | struct group_info tmp_gi; |
fd6daec9 | 629 | group_info *gi; |
703c8606 | 630 | group_info **slot; |
6fb5fa3c | 631 | |
ac6929b5 RB |
632 | gcc_assert (base != NULL_RTX); |
633 | ||
634 | /* Find the store_base_info structure for BASE, creating a new one | |
635 | if necessary. */ | |
636 | tmp_gi.rtx_base = base; | |
637 | slot = rtx_group_table->find_slot (&tmp_gi, INSERT); | |
638 | gi = *slot; | |
6fb5fa3c DB |
639 | |
640 | if (gi == NULL) | |
641 | { | |
fb0b2914 | 642 | *slot = gi = group_info_pool.allocate (); |
6fb5fa3c DB |
643 | gi->rtx_base = base; |
644 | gi->id = rtx_group_next_id++; | |
d32f725a | 645 | gi->base_mem = gen_rtx_MEM (BLKmode, base); |
6216f94e | 646 | gi->canon_base_addr = canon_rtx (base); |
3f9b14ff SB |
647 | gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack); |
648 | gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
649 | gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
650 | gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
651 | gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack); | |
652 | gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack); | |
653 | gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c | 654 | gi->process_globally = false; |
b8698a0f | 655 | gi->frame_related = |
6fb5fa3c DB |
656 | (base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx); |
657 | gi->offset_map_size_n = 0; | |
658 | gi->offset_map_size_p = 0; | |
659 | gi->offset_map_n = NULL; | |
660 | gi->offset_map_p = NULL; | |
9771b263 | 661 | rtx_group_vec.safe_push (gi); |
6fb5fa3c DB |
662 | } |
663 | ||
664 | return gi; | |
665 | } | |
666 | ||
667 | ||
668 | /* Initialization of data structures. */ | |
669 | ||
670 | static void | |
671 | dse_step0 (void) | |
672 | { | |
673 | locally_deleted = 0; | |
674 | globally_deleted = 0; | |
6fb5fa3c | 675 | |
3f9b14ff SB |
676 | bitmap_obstack_initialize (&dse_bitmap_obstack); |
677 | gcc_obstack_init (&dse_obstack); | |
678 | ||
679 | scratch = BITMAP_ALLOC (®_obstack); | |
680 | kill_on_calls = BITMAP_ALLOC (&dse_bitmap_obstack); | |
6fb5fa3c | 681 | |
6fb5fa3c | 682 | |
c203e8a7 | 683 | rtx_group_table = new hash_table<invariant_group_base_hasher> (11); |
6fb5fa3c | 684 | |
8b1c6fd7 | 685 | bb_table = XNEWVEC (bb_info_t, last_basic_block_for_fn (cfun)); |
6fb5fa3c DB |
686 | rtx_group_next_id = 0; |
687 | ||
e3b5732b | 688 | stores_off_frame_dead_at_return = !cfun->stdarg; |
6fb5fa3c DB |
689 | |
690 | init_alias_analysis (); | |
6fb5fa3c DB |
691 | } |
692 | ||
693 | ||
694 | \f | |
695 | /*---------------------------------------------------------------------------- | |
696 | First step. | |
697 | ||
698 | Scan all of the insns. Any random ordering of the blocks is fine. | |
0d52bcc1 | 699 | Each block is scanned in forward order to accommodate cselib which |
6fb5fa3c DB |
700 | is used to remove stores with non-constant bases. |
701 | ----------------------------------------------------------------------------*/ | |
702 | ||
703 | /* Delete all of the store_info recs from INSN_INFO. */ | |
704 | ||
b8698a0f | 705 | static void |
6fb5fa3c DB |
706 | free_store_info (insn_info_t insn_info) |
707 | { | |
fd6daec9 TS |
708 | store_info *cur = insn_info->store_rec; |
709 | while (cur) | |
6fb5fa3c | 710 | { |
fd6daec9 TS |
711 | store_info *next = cur->next; |
712 | if (cur->is_large) | |
713 | BITMAP_FREE (cur->positions_needed.large.bmap); | |
714 | if (cur->cse_base) | |
715 | cse_store_info_pool.remove (cur); | |
6fb5fa3c | 716 | else |
fd6daec9 TS |
717 | rtx_store_info_pool.remove (cur); |
718 | cur = next; | |
6fb5fa3c DB |
719 | } |
720 | ||
721 | insn_info->cannot_delete = true; | |
722 | insn_info->contains_cselib_groups = false; | |
723 | insn_info->store_rec = NULL; | |
724 | } | |
725 | ||
a79683d5 | 726 | struct note_add_store_info |
9e582b1d | 727 | { |
dc01c3d1 | 728 | rtx_insn *first, *current; |
9e582b1d JR |
729 | regset fixed_regs_live; |
730 | bool failure; | |
a79683d5 | 731 | }; |
9e582b1d JR |
732 | |
733 | /* Callback for emit_inc_dec_insn_before via note_stores. | |
734 | Check if a register is clobbered which is live afterwards. */ | |
735 | ||
736 | static void | |
737 | note_add_store (rtx loc, const_rtx expr ATTRIBUTE_UNUSED, void *data) | |
738 | { | |
dc01c3d1 | 739 | rtx_insn *insn; |
9e582b1d | 740 | note_add_store_info *info = (note_add_store_info *) data; |
9e582b1d JR |
741 | |
742 | if (!REG_P (loc)) | |
743 | return; | |
744 | ||
745 | /* If this register is referenced by the current or an earlier insn, | |
746 | that's OK. E.g. this applies to the register that is being incremented | |
747 | with this addition. */ | |
748 | for (insn = info->first; | |
749 | insn != NEXT_INSN (info->current); | |
750 | insn = NEXT_INSN (insn)) | |
751 | if (reg_referenced_p (loc, PATTERN (insn))) | |
752 | return; | |
753 | ||
754 | /* If we come here, we have a clobber of a register that's only OK | |
755 | if that register is not live. If we don't have liveness information | |
756 | available, fail now. */ | |
757 | if (!info->fixed_regs_live) | |
758 | { | |
53d1bae9 | 759 | info->failure = true; |
9e582b1d JR |
760 | return; |
761 | } | |
762 | /* Now check if this is a live fixed register. */ | |
53d1bae9 RS |
763 | unsigned int end_regno = END_REGNO (loc); |
764 | for (unsigned int regno = REGNO (loc); regno < end_regno; ++regno) | |
765 | if (REGNO_REG_SET_P (info->fixed_regs_live, regno)) | |
766 | info->failure = true; | |
9e582b1d JR |
767 | } |
768 | ||
4deef538 AO |
769 | /* Callback for for_each_inc_dec that emits an INSN that sets DEST to |
770 | SRC + SRCOFF before insn ARG. */ | |
6fb5fa3c DB |
771 | |
772 | static int | |
4deef538 AO |
773 | emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED, |
774 | rtx op ATTRIBUTE_UNUSED, | |
775 | rtx dest, rtx src, rtx srcoff, void *arg) | |
6fb5fa3c | 776 | { |
9e582b1d | 777 | insn_info_t insn_info = (insn_info_t) arg; |
dc01c3d1 | 778 | rtx_insn *insn = insn_info->insn, *new_insn, *cur; |
9e582b1d | 779 | note_add_store_info info; |
b8698a0f | 780 | |
4deef538 AO |
781 | /* We can reuse all operands without copying, because we are about |
782 | to delete the insn that contained it. */ | |
9e582b1d | 783 | if (srcoff) |
ed079c4b JJ |
784 | { |
785 | start_sequence (); | |
786 | emit_insn (gen_add3_insn (dest, src, srcoff)); | |
787 | new_insn = get_insns (); | |
788 | end_sequence (); | |
789 | } | |
9e582b1d | 790 | else |
1476d1bd | 791 | new_insn = gen_move_insn (dest, src); |
9e582b1d JR |
792 | info.first = new_insn; |
793 | info.fixed_regs_live = insn_info->fixed_regs_live; | |
794 | info.failure = false; | |
795 | for (cur = new_insn; cur; cur = NEXT_INSN (cur)) | |
796 | { | |
797 | info.current = cur; | |
798 | note_stores (PATTERN (cur), note_add_store, &info); | |
799 | } | |
6fb5fa3c | 800 | |
9e582b1d JR |
801 | /* If a failure was flagged above, return 1 so that for_each_inc_dec will |
802 | return it immediately, communicating the failure to its caller. */ | |
803 | if (info.failure) | |
804 | return 1; | |
805 | ||
806 | emit_insn_before (new_insn, insn); | |
6fb5fa3c | 807 | |
8d8e205b | 808 | return 0; |
6fb5fa3c DB |
809 | } |
810 | ||
9e582b1d JR |
811 | /* Before we delete INSN_INFO->INSN, make sure that the auto inc/dec, if it |
812 | is there, is split into a separate insn. | |
813 | Return true on success (or if there was nothing to do), false on failure. */ | |
6fb5fa3c | 814 | |
9e582b1d JR |
815 | static bool |
816 | check_for_inc_dec_1 (insn_info_t insn_info) | |
6fb5fa3c | 817 | { |
dd60a84c | 818 | rtx_insn *insn = insn_info->insn; |
6fb5fa3c DB |
819 | rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
820 | if (note) | |
8d8e205b RS |
821 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
822 | insn_info) == 0; | |
9e582b1d | 823 | return true; |
6fb5fa3c DB |
824 | } |
825 | ||
826 | ||
9e582b1d JR |
827 | /* Entry point for postreload. If you work on reload_cse, or you need this |
828 | anywhere else, consider if you can provide register liveness information | |
829 | and add a parameter to this function so that it can be passed down in | |
830 | insn_info.fixed_regs_live. */ | |
831 | bool | |
dd60a84c | 832 | check_for_inc_dec (rtx_insn *insn) |
9e582b1d | 833 | { |
da6603c6 | 834 | insn_info_type insn_info; |
9e582b1d JR |
835 | rtx note; |
836 | ||
837 | insn_info.insn = insn; | |
838 | insn_info.fixed_regs_live = NULL; | |
839 | note = find_reg_note (insn, REG_INC, NULL_RTX); | |
840 | if (note) | |
8d8e205b RS |
841 | return for_each_inc_dec (PATTERN (insn), emit_inc_dec_insn_before, |
842 | &insn_info) == 0; | |
9e582b1d JR |
843 | return true; |
844 | } | |
845 | ||
b8698a0f | 846 | /* Delete the insn and free all of the fields inside INSN_INFO. */ |
6fb5fa3c DB |
847 | |
848 | static void | |
849 | delete_dead_store_insn (insn_info_t insn_info) | |
850 | { | |
851 | read_info_t read_info; | |
852 | ||
853 | if (!dbg_cnt (dse)) | |
854 | return; | |
855 | ||
9e582b1d JR |
856 | if (!check_for_inc_dec_1 (insn_info)) |
857 | return; | |
456610d3 | 858 | if (dump_file && (dump_flags & TDF_DETAILS)) |
ac6929b5 RB |
859 | fprintf (dump_file, "Locally deleting insn %d\n", |
860 | INSN_UID (insn_info->insn)); | |
6fb5fa3c DB |
861 | |
862 | free_store_info (insn_info); | |
863 | read_info = insn_info->read_rec; | |
b8698a0f | 864 | |
6fb5fa3c DB |
865 | while (read_info) |
866 | { | |
867 | read_info_t next = read_info->next; | |
fb0b2914 | 868 | read_info_type_pool.remove (read_info); |
6fb5fa3c DB |
869 | read_info = next; |
870 | } | |
871 | insn_info->read_rec = NULL; | |
872 | ||
873 | delete_insn (insn_info->insn); | |
874 | locally_deleted++; | |
875 | insn_info->insn = NULL; | |
876 | ||
877 | insn_info->wild_read = false; | |
878 | } | |
879 | ||
88d8330d EB |
880 | /* Return whether DECL, a local variable, can possibly escape the current |
881 | function scope. */ | |
882 | ||
883 | static bool | |
884 | local_variable_can_escape (tree decl) | |
885 | { | |
886 | if (TREE_ADDRESSABLE (decl)) | |
887 | return true; | |
888 | ||
889 | /* If this is a partitioned variable, we need to consider all the variables | |
890 | in the partition. This is necessary because a store into one of them can | |
891 | be replaced with a store into another and this may not change the outcome | |
892 | of the escape analysis. */ | |
893 | if (cfun->gimple_df->decls_to_pointers != NULL) | |
894 | { | |
39c8aaa4 | 895 | tree *namep = cfun->gimple_df->decls_to_pointers->get (decl); |
88d8330d | 896 | if (namep) |
39c8aaa4 | 897 | return TREE_ADDRESSABLE (*namep); |
88d8330d EB |
898 | } |
899 | ||
900 | return false; | |
901 | } | |
902 | ||
903 | /* Return whether EXPR can possibly escape the current function scope. */ | |
904 | ||
d26c7090 ER |
905 | static bool |
906 | can_escape (tree expr) | |
907 | { | |
908 | tree base; | |
909 | if (!expr) | |
910 | return true; | |
911 | base = get_base_address (expr); | |
912 | if (DECL_P (base) | |
88d8330d EB |
913 | && !may_be_aliased (base) |
914 | && !(TREE_CODE (base) == VAR_DECL | |
915 | && !DECL_EXTERNAL (base) | |
916 | && !TREE_STATIC (base) | |
917 | && local_variable_can_escape (base))) | |
d26c7090 ER |
918 | return false; |
919 | return true; | |
920 | } | |
6fb5fa3c DB |
921 | |
922 | /* Set the store* bitmaps offset_map_size* fields in GROUP based on | |
923 | OFFSET and WIDTH. */ | |
924 | ||
925 | static void | |
fd6daec9 | 926 | set_usage_bits (group_info *group, HOST_WIDE_INT offset, HOST_WIDE_INT width, |
d26c7090 | 927 | tree expr) |
6fb5fa3c DB |
928 | { |
929 | HOST_WIDE_INT i; | |
d26c7090 | 930 | bool expr_escapes = can_escape (expr); |
8dd5516b | 931 | if (offset > -MAX_OFFSET && offset + width < MAX_OFFSET) |
6fb5fa3c DB |
932 | for (i=offset; i<offset+width; i++) |
933 | { | |
934 | bitmap store1; | |
935 | bitmap store2; | |
d26c7090 | 936 | bitmap escaped; |
6fb5fa3c DB |
937 | int ai; |
938 | if (i < 0) | |
939 | { | |
940 | store1 = group->store1_n; | |
941 | store2 = group->store2_n; | |
d26c7090 | 942 | escaped = group->escaped_n; |
6fb5fa3c DB |
943 | ai = -i; |
944 | } | |
945 | else | |
946 | { | |
947 | store1 = group->store1_p; | |
948 | store2 = group->store2_p; | |
d26c7090 | 949 | escaped = group->escaped_p; |
6fb5fa3c DB |
950 | ai = i; |
951 | } | |
b8698a0f | 952 | |
fcaa4ca4 | 953 | if (!bitmap_set_bit (store1, ai)) |
6fb5fa3c | 954 | bitmap_set_bit (store2, ai); |
b8698a0f | 955 | else |
6fb5fa3c | 956 | { |
6fb5fa3c DB |
957 | if (i < 0) |
958 | { | |
959 | if (group->offset_map_size_n < ai) | |
960 | group->offset_map_size_n = ai; | |
961 | } | |
962 | else | |
963 | { | |
964 | if (group->offset_map_size_p < ai) | |
965 | group->offset_map_size_p = ai; | |
966 | } | |
967 | } | |
d26c7090 ER |
968 | if (expr_escapes) |
969 | bitmap_set_bit (escaped, ai); | |
6fb5fa3c DB |
970 | } |
971 | } | |
972 | ||
d26c7090 ER |
973 | static void |
974 | reset_active_stores (void) | |
975 | { | |
976 | active_local_stores = NULL; | |
977 | active_local_stores_len = 0; | |
978 | } | |
6fb5fa3c | 979 | |
d26c7090 | 980 | /* Free all READ_REC of the LAST_INSN of BB_INFO. */ |
6fb5fa3c DB |
981 | |
982 | static void | |
d26c7090 | 983 | free_read_records (bb_info_t bb_info) |
6fb5fa3c DB |
984 | { |
985 | insn_info_t insn_info = bb_info->last_insn; | |
986 | read_info_t *ptr = &insn_info->read_rec; | |
6fb5fa3c DB |
987 | while (*ptr) |
988 | { | |
989 | read_info_t next = (*ptr)->next; | |
ac6929b5 RB |
990 | read_info_type_pool.remove (*ptr); |
991 | *ptr = next; | |
6fb5fa3c | 992 | } |
d26c7090 ER |
993 | } |
994 | ||
995 | /* Set the BB_INFO so that the last insn is marked as a wild read. */ | |
996 | ||
997 | static void | |
998 | add_wild_read (bb_info_t bb_info) | |
999 | { | |
1000 | insn_info_t insn_info = bb_info->last_insn; | |
6fb5fa3c | 1001 | insn_info->wild_read = true; |
d26c7090 ER |
1002 | free_read_records (bb_info); |
1003 | reset_active_stores (); | |
6fb5fa3c DB |
1004 | } |
1005 | ||
d26c7090 ER |
1006 | /* Set the BB_INFO so that the last insn is marked as a wild read of |
1007 | non-frame locations. */ | |
1008 | ||
1009 | static void | |
1010 | add_non_frame_wild_read (bb_info_t bb_info) | |
1011 | { | |
1012 | insn_info_t insn_info = bb_info->last_insn; | |
1013 | insn_info->non_frame_wild_read = true; | |
1014 | free_read_records (bb_info); | |
1015 | reset_active_stores (); | |
1016 | } | |
6fb5fa3c | 1017 | |
50f0f366 EB |
1018 | /* Return true if X is a constant or one of the registers that behave |
1019 | as a constant over the life of a function. This is equivalent to | |
1020 | !rtx_varies_p for memory addresses. */ | |
6fb5fa3c DB |
1021 | |
1022 | static bool | |
1023 | const_or_frame_p (rtx x) | |
1024 | { | |
d8116890 KZ |
1025 | if (CONSTANT_P (x)) |
1026 | return true; | |
1027 | ||
1028 | if (GET_CODE (x) == REG) | |
6fb5fa3c | 1029 | { |
6fb5fa3c DB |
1030 | /* Note that we have to test for the actual rtx used for the frame |
1031 | and arg pointers and not just the register number in case we have | |
1032 | eliminated the frame and/or arg pointer and are using it | |
1033 | for pseudos. */ | |
1034 | if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx | |
1035 | /* The arg pointer varies if it is not a fixed register. */ | |
1036 | || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) | |
1037 | || x == pic_offset_table_rtx) | |
1038 | return true; | |
1039 | return false; | |
6fb5fa3c | 1040 | } |
da6603c6 | 1041 | |
d8116890 | 1042 | return false; |
6fb5fa3c DB |
1043 | } |
1044 | ||
b8698a0f L |
1045 | /* Take all reasonable action to put the address of MEM into the form |
1046 | that we can do analysis on. | |
6fb5fa3c DB |
1047 | |
1048 | The gold standard is to get the address into the form: address + | |
1049 | OFFSET where address is something that rtx_varies_p considers a | |
1050 | constant. When we can get the address in this form, we can do | |
1051 | global analysis on it. Note that for constant bases, address is | |
1052 | not actually returned, only the group_id. The address can be | |
1053 | obtained from that. | |
1054 | ||
1055 | If that fails, we try cselib to get a value we can at least use | |
b8698a0f L |
1056 | locally. If that fails we return false. |
1057 | ||
6fb5fa3c DB |
1058 | The GROUP_ID is set to -1 for cselib bases and the index of the |
1059 | group for non_varying bases. | |
1060 | ||
1061 | FOR_READ is true if this is a mem read and false if not. */ | |
1062 | ||
1063 | static bool | |
1064 | canon_address (rtx mem, | |
6fb5fa3c | 1065 | int *group_id, |
b8698a0f | 1066 | HOST_WIDE_INT *offset, |
6fb5fa3c DB |
1067 | cselib_val **base) |
1068 | { | |
ef4bddc2 | 1069 | machine_mode address_mode = get_address_mode (mem); |
6fb5fa3c DB |
1070 | rtx mem_address = XEXP (mem, 0); |
1071 | rtx expanded_address, address; | |
403c7520 JJ |
1072 | int expanded; |
1073 | ||
4deef538 | 1074 | cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem)); |
6fb5fa3c | 1075 | |
456610d3 | 1076 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1077 | { |
1078 | fprintf (dump_file, " mem: "); | |
1079 | print_inline_rtx (dump_file, mem_address, 0); | |
1080 | fprintf (dump_file, "\n"); | |
1081 | } | |
1082 | ||
403c7520 JJ |
1083 | /* First see if just canon_rtx (mem_address) is const or frame, |
1084 | if not, try cselib_expand_value_rtx and call canon_rtx on that. */ | |
1085 | address = NULL_RTX; | |
1086 | for (expanded = 0; expanded < 2; expanded++) | |
1087 | { | |
1088 | if (expanded) | |
1089 | { | |
1090 | /* Use cselib to replace all of the reg references with the full | |
b8698a0f | 1091 | expression. This will take care of the case where we have |
6fb5fa3c | 1092 | |
403c7520 JJ |
1093 | r_x = base + offset; |
1094 | val = *r_x; | |
b8698a0f L |
1095 | |
1096 | by making it into | |
6fb5fa3c | 1097 | |
403c7520 | 1098 | val = *(base + offset); */ |
6fb5fa3c | 1099 | |
403c7520 JJ |
1100 | expanded_address = cselib_expand_value_rtx (mem_address, |
1101 | scratch, 5); | |
6fb5fa3c | 1102 | |
403c7520 JJ |
1103 | /* If this fails, just go with the address from first |
1104 | iteration. */ | |
1105 | if (!expanded_address) | |
1106 | break; | |
1107 | } | |
1108 | else | |
1109 | expanded_address = mem_address; | |
6fb5fa3c | 1110 | |
403c7520 JJ |
1111 | /* Split the address into canonical BASE + OFFSET terms. */ |
1112 | address = canon_rtx (expanded_address); | |
6fb5fa3c | 1113 | |
403c7520 | 1114 | *offset = 0; |
6fb5fa3c | 1115 | |
456610d3 | 1116 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1117 | { |
1118 | if (expanded) | |
1119 | { | |
1120 | fprintf (dump_file, "\n after cselib_expand address: "); | |
1121 | print_inline_rtx (dump_file, expanded_address, 0); | |
1122 | fprintf (dump_file, "\n"); | |
1123 | } | |
6fb5fa3c | 1124 | |
403c7520 JJ |
1125 | fprintf (dump_file, "\n after canon_rtx address: "); |
1126 | print_inline_rtx (dump_file, address, 0); | |
1127 | fprintf (dump_file, "\n"); | |
1128 | } | |
6fb5fa3c | 1129 | |
403c7520 JJ |
1130 | if (GET_CODE (address) == CONST) |
1131 | address = XEXP (address, 0); | |
6fb5fa3c | 1132 | |
403c7520 JJ |
1133 | if (GET_CODE (address) == PLUS |
1134 | && CONST_INT_P (XEXP (address, 1))) | |
1135 | { | |
1136 | *offset = INTVAL (XEXP (address, 1)); | |
1137 | address = XEXP (address, 0); | |
1138 | } | |
6fb5fa3c | 1139 | |
09e881c9 BE |
1140 | if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem)) |
1141 | && const_or_frame_p (address)) | |
6fb5fa3c | 1142 | { |
fd6daec9 | 1143 | group_info *group = get_group_info (address); |
403c7520 | 1144 | |
456610d3 | 1145 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1146 | fprintf (dump_file, " gid=%d offset=%d \n", |
1147 | group->id, (int)*offset); | |
1148 | *base = NULL; | |
1149 | *group_id = group->id; | |
1150 | return true; | |
6fb5fa3c | 1151 | } |
403c7520 JJ |
1152 | } |
1153 | ||
4deef538 | 1154 | *base = cselib_lookup (address, address_mode, true, GET_MODE (mem)); |
403c7520 JJ |
1155 | *group_id = -1; |
1156 | ||
1157 | if (*base == NULL) | |
1158 | { | |
456610d3 | 1159 | if (dump_file && (dump_flags & TDF_DETAILS)) |
403c7520 JJ |
1160 | fprintf (dump_file, " no cselib val - should be a wild read.\n"); |
1161 | return false; | |
6fb5fa3c | 1162 | } |
456610d3 | 1163 | if (dump_file && (dump_flags & TDF_DETAILS)) |
5440c0e7 AO |
1164 | fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n", |
1165 | (*base)->uid, (*base)->hash, (int)*offset); | |
6fb5fa3c DB |
1166 | return true; |
1167 | } | |
1168 | ||
1169 | ||
1170 | /* Clear the rhs field from the active_local_stores array. */ | |
1171 | ||
1172 | static void | |
1173 | clear_rhs_from_active_local_stores (void) | |
1174 | { | |
1175 | insn_info_t ptr = active_local_stores; | |
1176 | ||
1177 | while (ptr) | |
1178 | { | |
fd6daec9 | 1179 | store_info *store_info = ptr->store_rec; |
6fb5fa3c DB |
1180 | /* Skip the clobbers. */ |
1181 | while (!store_info->is_set) | |
1182 | store_info = store_info->next; | |
1183 | ||
1184 | store_info->rhs = NULL; | |
8dd5516b | 1185 | store_info->const_rhs = NULL; |
6fb5fa3c DB |
1186 | |
1187 | ptr = ptr->next_local_store; | |
1188 | } | |
1189 | } | |
1190 | ||
1191 | ||
8dd5516b JJ |
1192 | /* Mark byte POS bytes from the beginning of store S_INFO as unneeded. */ |
1193 | ||
1194 | static inline void | |
fd6daec9 | 1195 | set_position_unneeded (store_info *s_info, int pos) |
8dd5516b JJ |
1196 | { |
1197 | if (__builtin_expect (s_info->is_large, false)) | |
1198 | { | |
fcaa4ca4 NF |
1199 | if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos)) |
1200 | s_info->positions_needed.large.count++; | |
8dd5516b JJ |
1201 | } |
1202 | else | |
1203 | s_info->positions_needed.small_bitmask | |
fecfbfa4 | 1204 | &= ~(HOST_WIDE_INT_1U << pos); |
8dd5516b JJ |
1205 | } |
1206 | ||
1207 | /* Mark the whole store S_INFO as unneeded. */ | |
1208 | ||
1209 | static inline void | |
fd6daec9 | 1210 | set_all_positions_unneeded (store_info *s_info) |
8dd5516b JJ |
1211 | { |
1212 | if (__builtin_expect (s_info->is_large, false)) | |
1213 | { | |
1214 | int pos, end = s_info->end - s_info->begin; | |
1215 | for (pos = 0; pos < end; pos++) | |
dc491a25 | 1216 | bitmap_set_bit (s_info->positions_needed.large.bmap, pos); |
8dd5516b JJ |
1217 | s_info->positions_needed.large.count = end; |
1218 | } | |
1219 | else | |
07e96250 | 1220 | s_info->positions_needed.small_bitmask = HOST_WIDE_INT_0U; |
8dd5516b JJ |
1221 | } |
1222 | ||
1223 | /* Return TRUE if any bytes from S_INFO store are needed. */ | |
1224 | ||
1225 | static inline bool | |
fd6daec9 | 1226 | any_positions_needed_p (store_info *s_info) |
8dd5516b JJ |
1227 | { |
1228 | if (__builtin_expect (s_info->is_large, false)) | |
1229 | return (s_info->positions_needed.large.count | |
1230 | < s_info->end - s_info->begin); | |
1231 | else | |
07e96250 | 1232 | return (s_info->positions_needed.small_bitmask != HOST_WIDE_INT_0U); |
8dd5516b JJ |
1233 | } |
1234 | ||
1235 | /* Return TRUE if all bytes START through START+WIDTH-1 from S_INFO | |
1236 | store are needed. */ | |
1237 | ||
1238 | static inline bool | |
fd6daec9 | 1239 | all_positions_needed_p (store_info *s_info, int start, int width) |
8dd5516b JJ |
1240 | { |
1241 | if (__builtin_expect (s_info->is_large, false)) | |
1242 | { | |
1243 | int end = start + width; | |
1244 | while (start < end) | |
dc491a25 | 1245 | if (bitmap_bit_p (s_info->positions_needed.large.bmap, start++)) |
8dd5516b JJ |
1246 | return false; |
1247 | return true; | |
1248 | } | |
1249 | else | |
1250 | { | |
1251 | unsigned HOST_WIDE_INT mask = lowpart_bitmask (width) << start; | |
1252 | return (s_info->positions_needed.small_bitmask & mask) == mask; | |
1253 | } | |
1254 | } | |
1255 | ||
1256 | ||
fd6daec9 | 1257 | static rtx get_stored_val (store_info *, machine_mode, HOST_WIDE_INT, |
8dd5516b JJ |
1258 | HOST_WIDE_INT, basic_block, bool); |
1259 | ||
1260 | ||
6fb5fa3c DB |
1261 | /* BODY is an instruction pattern that belongs to INSN. Return 1 if |
1262 | there is a candidate store, after adding it to the appropriate | |
1263 | local store group if so. */ | |
1264 | ||
1265 | static int | |
1266 | record_store (rtx body, bb_info_t bb_info) | |
1267 | { | |
6216f94e | 1268 | rtx mem, rhs, const_rhs, mem_addr; |
6fb5fa3c DB |
1269 | HOST_WIDE_INT offset = 0; |
1270 | HOST_WIDE_INT width = 0; | |
6fb5fa3c | 1271 | insn_info_t insn_info = bb_info->last_insn; |
fd6daec9 | 1272 | store_info *store_info = NULL; |
6fb5fa3c DB |
1273 | int group_id; |
1274 | cselib_val *base = NULL; | |
8dd5516b | 1275 | insn_info_t ptr, last, redundant_reason; |
6fb5fa3c DB |
1276 | bool store_is_unused; |
1277 | ||
1278 | if (GET_CODE (body) != SET && GET_CODE (body) != CLOBBER) | |
1279 | return 0; | |
1280 | ||
8dd5516b JJ |
1281 | mem = SET_DEST (body); |
1282 | ||
6fb5fa3c DB |
1283 | /* If this is not used, then this cannot be used to keep the insn |
1284 | from being deleted. On the other hand, it does provide something | |
1285 | that can be used to prove that another store is dead. */ | |
1286 | store_is_unused | |
8dd5516b | 1287 | = (find_reg_note (insn_info->insn, REG_UNUSED, mem) != NULL); |
6fb5fa3c DB |
1288 | |
1289 | /* Check whether that value is a suitable memory location. */ | |
6fb5fa3c DB |
1290 | if (!MEM_P (mem)) |
1291 | { | |
1292 | /* If the set or clobber is unused, then it does not effect our | |
1293 | ability to get rid of the entire insn. */ | |
1294 | if (!store_is_unused) | |
1295 | insn_info->cannot_delete = true; | |
1296 | return 0; | |
1297 | } | |
1298 | ||
1299 | /* At this point we know mem is a mem. */ | |
1300 | if (GET_MODE (mem) == BLKmode) | |
1301 | { | |
1302 | if (GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
1303 | { | |
456610d3 | 1304 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1305 | fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n"); |
1306 | add_wild_read (bb_info); | |
1307 | insn_info->cannot_delete = true; | |
8dd5516b | 1308 | return 0; |
6fb5fa3c | 1309 | } |
8dd5516b JJ |
1310 | /* Handle (set (mem:BLK (addr) [... S36 ...]) (const_int 0)) |
1311 | as memset (addr, 0, 36); */ | |
f5541398 RS |
1312 | else if (!MEM_SIZE_KNOWN_P (mem) |
1313 | || MEM_SIZE (mem) <= 0 | |
1314 | || MEM_SIZE (mem) > MAX_OFFSET | |
8dd5516b | 1315 | || GET_CODE (body) != SET |
8dd5516b | 1316 | || !CONST_INT_P (SET_SRC (body))) |
6fb5fa3c | 1317 | { |
8dd5516b JJ |
1318 | if (!store_is_unused) |
1319 | { | |
1320 | /* If the set or clobber is unused, then it does not effect our | |
1321 | ability to get rid of the entire insn. */ | |
1322 | insn_info->cannot_delete = true; | |
1323 | clear_rhs_from_active_local_stores (); | |
1324 | } | |
1325 | return 0; | |
6fb5fa3c | 1326 | } |
6fb5fa3c DB |
1327 | } |
1328 | ||
1329 | /* We can still process a volatile mem, we just cannot delete it. */ | |
1330 | if (MEM_VOLATILE_P (mem)) | |
8dd5516b | 1331 | insn_info->cannot_delete = true; |
6fb5fa3c | 1332 | |
ac6929b5 | 1333 | if (!canon_address (mem, &group_id, &offset, &base)) |
6fb5fa3c DB |
1334 | { |
1335 | clear_rhs_from_active_local_stores (); | |
1336 | return 0; | |
1337 | } | |
1338 | ||
8dd5516b | 1339 | if (GET_MODE (mem) == BLKmode) |
f5541398 | 1340 | width = MEM_SIZE (mem); |
8dd5516b | 1341 | else |
6f557e0e | 1342 | width = GET_MODE_SIZE (GET_MODE (mem)); |
6fb5fa3c | 1343 | |
ac6929b5 | 1344 | if (group_id >= 0) |
6fb5fa3c DB |
1345 | { |
1346 | /* In the restrictive case where the base is a constant or the | |
1347 | frame pointer we can do global analysis. */ | |
b8698a0f | 1348 | |
fd6daec9 | 1349 | group_info *group |
9771b263 | 1350 | = rtx_group_vec[group_id]; |
d26c7090 | 1351 | tree expr = MEM_EXPR (mem); |
b8698a0f | 1352 | |
da6603c6 | 1353 | store_info = rtx_store_info_pool.allocate (); |
d26c7090 | 1354 | set_usage_bits (group, offset, width, expr); |
6fb5fa3c | 1355 | |
456610d3 | 1356 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1357 | fprintf (dump_file, " processing const base store gid=%d[%d..%d)\n", |
1358 | group_id, (int)offset, (int)(offset+width)); | |
1359 | } | |
1360 | else | |
1361 | { | |
9e412ca3 | 1362 | if (may_be_sp_based_p (XEXP (mem, 0))) |
50f0f366 | 1363 | insn_info->stack_pointer_based = true; |
6fb5fa3c | 1364 | insn_info->contains_cselib_groups = true; |
50f0f366 | 1365 | |
da6603c6 | 1366 | store_info = cse_store_info_pool.allocate (); |
6fb5fa3c DB |
1367 | group_id = -1; |
1368 | ||
456610d3 | 1369 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1370 | fprintf (dump_file, " processing cselib store [%d..%d)\n", |
1371 | (int)offset, (int)(offset+width)); | |
1372 | } | |
1373 | ||
8dd5516b JJ |
1374 | const_rhs = rhs = NULL_RTX; |
1375 | if (GET_CODE (body) == SET | |
1376 | /* No place to keep the value after ra. */ | |
1377 | && !reload_completed | |
1378 | && (REG_P (SET_SRC (body)) | |
1379 | || GET_CODE (SET_SRC (body)) == SUBREG | |
1380 | || CONSTANT_P (SET_SRC (body))) | |
1381 | && !MEM_VOLATILE_P (mem) | |
1382 | /* Sometimes the store and reload is used for truncation and | |
1383 | rounding. */ | |
1384 | && !(FLOAT_MODE_P (GET_MODE (mem)) && (flag_float_store))) | |
1385 | { | |
1386 | rhs = SET_SRC (body); | |
1387 | if (CONSTANT_P (rhs)) | |
1388 | const_rhs = rhs; | |
1389 | else if (body == PATTERN (insn_info->insn)) | |
1390 | { | |
1391 | rtx tem = find_reg_note (insn_info->insn, REG_EQUAL, NULL_RTX); | |
1392 | if (tem && CONSTANT_P (XEXP (tem, 0))) | |
1393 | const_rhs = XEXP (tem, 0); | |
1394 | } | |
1395 | if (const_rhs == NULL_RTX && REG_P (rhs)) | |
1396 | { | |
1397 | rtx tem = cselib_expand_value_rtx (rhs, scratch, 5); | |
1398 | ||
1399 | if (tem && CONSTANT_P (tem)) | |
1400 | const_rhs = tem; | |
1401 | } | |
1402 | } | |
1403 | ||
6fb5fa3c DB |
1404 | /* Check to see if this stores causes some other stores to be |
1405 | dead. */ | |
1406 | ptr = active_local_stores; | |
1407 | last = NULL; | |
8dd5516b | 1408 | redundant_reason = NULL; |
6216f94e | 1409 | mem = canon_rtx (mem); |
ac6929b5 RB |
1410 | |
1411 | if (group_id < 0) | |
1412 | mem_addr = base->val_rtx; | |
6216f94e JJ |
1413 | else |
1414 | { | |
ac6929b5 RB |
1415 | group_info *group = rtx_group_vec[group_id]; |
1416 | mem_addr = group->canon_base_addr; | |
6216f94e | 1417 | } |
ac6929b5 RB |
1418 | if (offset) |
1419 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); | |
6fb5fa3c DB |
1420 | |
1421 | while (ptr) | |
1422 | { | |
1423 | insn_info_t next = ptr->next_local_store; | |
fd6daec9 | 1424 | struct store_info *s_info = ptr->store_rec; |
60564289 | 1425 | bool del = true; |
6fb5fa3c DB |
1426 | |
1427 | /* Skip the clobbers. We delete the active insn if this insn | |
6ed3da00 | 1428 | shadows the set. To have been put on the active list, it |
6fb5fa3c DB |
1429 | has exactly on set. */ |
1430 | while (!s_info->is_set) | |
1431 | s_info = s_info->next; | |
1432 | ||
ac6929b5 | 1433 | if (s_info->group_id == group_id && s_info->cse_base == base) |
6fb5fa3c DB |
1434 | { |
1435 | HOST_WIDE_INT i; | |
456610d3 | 1436 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 1437 | fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n", |
b8698a0f | 1438 | INSN_UID (ptr->insn), s_info->group_id, |
6fb5fa3c | 1439 | (int)s_info->begin, (int)s_info->end); |
8dd5516b JJ |
1440 | |
1441 | /* Even if PTR won't be eliminated as unneeded, if both | |
1442 | PTR and this insn store the same constant value, we might | |
1443 | eliminate this insn instead. */ | |
1444 | if (s_info->const_rhs | |
1445 | && const_rhs | |
1446 | && offset >= s_info->begin | |
1447 | && offset + width <= s_info->end | |
1448 | && all_positions_needed_p (s_info, offset - s_info->begin, | |
1449 | width)) | |
1450 | { | |
1451 | if (GET_MODE (mem) == BLKmode) | |
1452 | { | |
1453 | if (GET_MODE (s_info->mem) == BLKmode | |
1454 | && s_info->const_rhs == const_rhs) | |
1455 | redundant_reason = ptr; | |
1456 | } | |
1457 | else if (s_info->const_rhs == const0_rtx | |
1458 | && const_rhs == const0_rtx) | |
1459 | redundant_reason = ptr; | |
1460 | else | |
1461 | { | |
1462 | rtx val; | |
1463 | start_sequence (); | |
1464 | val = get_stored_val (s_info, GET_MODE (mem), | |
1465 | offset, offset + width, | |
1466 | BLOCK_FOR_INSN (insn_info->insn), | |
1467 | true); | |
1468 | if (get_insns () != NULL) | |
1469 | val = NULL_RTX; | |
1470 | end_sequence (); | |
1471 | if (val && rtx_equal_p (val, const_rhs)) | |
1472 | redundant_reason = ptr; | |
1473 | } | |
1474 | } | |
1475 | ||
1476 | for (i = MAX (offset, s_info->begin); | |
1477 | i < offset + width && i < s_info->end; | |
1478 | i++) | |
1479 | set_position_unneeded (s_info, i - s_info->begin); | |
6fb5fa3c DB |
1480 | } |
1481 | else if (s_info->rhs) | |
1482 | /* Need to see if it is possible for this store to overwrite | |
1483 | the value of store_info. If it is, set the rhs to NULL to | |
1484 | keep it from being used to remove a load. */ | |
1485 | { | |
43b9f499 RB |
1486 | if (canon_output_dependence (s_info->mem, true, |
1487 | mem, GET_MODE (mem), | |
1488 | mem_addr)) | |
8dd5516b JJ |
1489 | { |
1490 | s_info->rhs = NULL; | |
1491 | s_info->const_rhs = NULL; | |
1492 | } | |
6fb5fa3c | 1493 | } |
6216f94e | 1494 | |
6fb5fa3c DB |
1495 | /* An insn can be deleted if every position of every one of |
1496 | its s_infos is zero. */ | |
1b6fa860 | 1497 | if (any_positions_needed_p (s_info)) |
60564289 | 1498 | del = false; |
8dd5516b | 1499 | |
60564289 | 1500 | if (del) |
6fb5fa3c DB |
1501 | { |
1502 | insn_info_t insn_to_delete = ptr; | |
b8698a0f | 1503 | |
dabd47e7 | 1504 | active_local_stores_len--; |
6fb5fa3c DB |
1505 | if (last) |
1506 | last->next_local_store = ptr->next_local_store; | |
1507 | else | |
1508 | active_local_stores = ptr->next_local_store; | |
b8698a0f | 1509 | |
1b6fa860 JJ |
1510 | if (!insn_to_delete->cannot_delete) |
1511 | delete_dead_store_insn (insn_to_delete); | |
6fb5fa3c DB |
1512 | } |
1513 | else | |
1514 | last = ptr; | |
b8698a0f | 1515 | |
6fb5fa3c DB |
1516 | ptr = next; |
1517 | } | |
b8698a0f | 1518 | |
6fb5fa3c DB |
1519 | /* Finish filling in the store_info. */ |
1520 | store_info->next = insn_info->store_rec; | |
1521 | insn_info->store_rec = store_info; | |
6216f94e | 1522 | store_info->mem = mem; |
6216f94e | 1523 | store_info->mem_addr = mem_addr; |
6fb5fa3c | 1524 | store_info->cse_base = base; |
8dd5516b JJ |
1525 | if (width > HOST_BITS_PER_WIDE_INT) |
1526 | { | |
1527 | store_info->is_large = true; | |
1528 | store_info->positions_needed.large.count = 0; | |
3f9b14ff | 1529 | store_info->positions_needed.large.bmap = BITMAP_ALLOC (&dse_bitmap_obstack); |
8dd5516b JJ |
1530 | } |
1531 | else | |
1532 | { | |
1533 | store_info->is_large = false; | |
1534 | store_info->positions_needed.small_bitmask = lowpart_bitmask (width); | |
1535 | } | |
6fb5fa3c DB |
1536 | store_info->group_id = group_id; |
1537 | store_info->begin = offset; | |
1538 | store_info->end = offset + width; | |
1539 | store_info->is_set = GET_CODE (body) == SET; | |
8dd5516b JJ |
1540 | store_info->rhs = rhs; |
1541 | store_info->const_rhs = const_rhs; | |
1542 | store_info->redundant_reason = redundant_reason; | |
6fb5fa3c | 1543 | |
6fb5fa3c DB |
1544 | /* If this is a clobber, we return 0. We will only be able to |
1545 | delete this insn if there is only one store USED store, but we | |
1546 | can use the clobber to delete other stores earlier. */ | |
1547 | return store_info->is_set ? 1 : 0; | |
1548 | } | |
1549 | ||
1550 | ||
1551 | static void | |
1552 | dump_insn_info (const char * start, insn_info_t insn_info) | |
1553 | { | |
b8698a0f | 1554 | fprintf (dump_file, "%s insn=%d %s\n", start, |
6fb5fa3c DB |
1555 | INSN_UID (insn_info->insn), |
1556 | insn_info->store_rec ? "has store" : "naked"); | |
1557 | } | |
1558 | ||
1559 | ||
8660aaae EC |
1560 | /* If the modes are different and the value's source and target do not |
1561 | line up, we need to extract the value from lower part of the rhs of | |
1562 | the store, shift it, and then put it into a form that can be shoved | |
1563 | into the read_insn. This function generates a right SHIFT of a | |
1564 | value that is at least ACCESS_SIZE bytes wide of READ_MODE. The | |
1565 | shift sequence is returned or NULL if we failed to find a | |
1566 | shift. */ | |
1567 | ||
1568 | static rtx | |
18b526e8 | 1569 | find_shift_sequence (int access_size, |
fd6daec9 | 1570 | store_info *store_info, |
ef4bddc2 | 1571 | machine_mode read_mode, |
8dd5516b | 1572 | int shift, bool speed, bool require_cst) |
8660aaae | 1573 | { |
ef4bddc2 RS |
1574 | machine_mode store_mode = GET_MODE (store_info->mem); |
1575 | machine_mode new_mode; | |
18b526e8 | 1576 | rtx read_reg = NULL; |
8660aaae EC |
1577 | |
1578 | /* Some machines like the x86 have shift insns for each size of | |
1579 | operand. Other machines like the ppc or the ia-64 may only have | |
1580 | shift insns that shift values within 32 or 64 bit registers. | |
1581 | This loop tries to find the smallest shift insn that will right | |
1582 | justify the value we want to read but is available in one insn on | |
1583 | the machine. */ | |
1584 | ||
18b526e8 RS |
1585 | for (new_mode = smallest_mode_for_size (access_size * BITS_PER_UNIT, |
1586 | MODE_INT); | |
1587 | GET_MODE_BITSIZE (new_mode) <= BITS_PER_WORD; | |
1588 | new_mode = GET_MODE_WIDER_MODE (new_mode)) | |
8660aaae | 1589 | { |
dc01c3d1 DM |
1590 | rtx target, new_reg, new_lhs; |
1591 | rtx_insn *shift_seq, *insn; | |
d898d29b | 1592 | int cost; |
348eea5f | 1593 | |
72a2609f JJ |
1594 | /* If a constant was stored into memory, try to simplify it here, |
1595 | otherwise the cost of the shift might preclude this optimization | |
1596 | e.g. at -Os, even when no actual shift will be needed. */ | |
8dd5516b | 1597 | if (store_info->const_rhs) |
72a2609f JJ |
1598 | { |
1599 | unsigned int byte = subreg_lowpart_offset (new_mode, store_mode); | |
8dd5516b JJ |
1600 | rtx ret = simplify_subreg (new_mode, store_info->const_rhs, |
1601 | store_mode, byte); | |
72a2609f JJ |
1602 | if (ret && CONSTANT_P (ret)) |
1603 | { | |
1604 | ret = simplify_const_binary_operation (LSHIFTRT, new_mode, | |
1605 | ret, GEN_INT (shift)); | |
1606 | if (ret && CONSTANT_P (ret)) | |
1607 | { | |
1608 | byte = subreg_lowpart_offset (read_mode, new_mode); | |
1609 | ret = simplify_subreg (read_mode, ret, new_mode, byte); | |
1610 | if (ret && CONSTANT_P (ret) | |
e548c9df AM |
1611 | && (set_src_cost (ret, read_mode, speed) |
1612 | <= COSTS_N_INSNS (1))) | |
72a2609f JJ |
1613 | return ret; |
1614 | } | |
1615 | } | |
1616 | } | |
1617 | ||
8dd5516b JJ |
1618 | if (require_cst) |
1619 | return NULL_RTX; | |
1620 | ||
18b526e8 RS |
1621 | /* Try a wider mode if truncating the store mode to NEW_MODE |
1622 | requires a real instruction. */ | |
1623 | if (GET_MODE_BITSIZE (new_mode) < GET_MODE_BITSIZE (store_mode) | |
d0edd768 | 1624 | && !TRULY_NOOP_TRUNCATION_MODES_P (new_mode, store_mode)) |
348eea5f RS |
1625 | continue; |
1626 | ||
18b526e8 RS |
1627 | /* Also try a wider mode if the necessary punning is either not |
1628 | desirable or not possible. */ | |
1629 | if (!CONSTANT_P (store_info->rhs) | |
1630 | && !MODES_TIEABLE_P (new_mode, store_mode)) | |
1631 | continue; | |
18b526e8 | 1632 | |
348eea5f | 1633 | new_reg = gen_reg_rtx (new_mode); |
8660aaae EC |
1634 | |
1635 | start_sequence (); | |
1636 | ||
1637 | /* In theory we could also check for an ashr. Ian Taylor knows | |
1638 | of one dsp where the cost of these two was not the same. But | |
1639 | this really is a rare case anyway. */ | |
1640 | target = expand_binop (new_mode, lshr_optab, new_reg, | |
1641 | GEN_INT (shift), new_reg, 1, OPTAB_DIRECT); | |
1642 | ||
c6f3019a RS |
1643 | shift_seq = get_insns (); |
1644 | end_sequence (); | |
8660aaae | 1645 | |
c6f3019a RS |
1646 | if (target != new_reg || shift_seq == NULL) |
1647 | continue; | |
1648 | ||
1649 | cost = 0; | |
1650 | for (insn = shift_seq; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
1651 | if (INSN_P (insn)) | |
f40751dd | 1652 | cost += insn_rtx_cost (PATTERN (insn), speed); |
c6f3019a RS |
1653 | |
1654 | /* The computation up to here is essentially independent | |
1655 | of the arguments and could be precomputed. It may | |
1656 | not be worth doing so. We could precompute if | |
1657 | worthwhile or at least cache the results. The result | |
06acf7d0 RS |
1658 | technically depends on both SHIFT and ACCESS_SIZE, |
1659 | but in practice the answer will depend only on ACCESS_SIZE. */ | |
c6f3019a RS |
1660 | |
1661 | if (cost > COSTS_N_INSNS (1)) | |
1662 | continue; | |
1663 | ||
d898d29b JJ |
1664 | new_lhs = extract_low_bits (new_mode, store_mode, |
1665 | copy_rtx (store_info->rhs)); | |
1666 | if (new_lhs == NULL_RTX) | |
1667 | continue; | |
1668 | ||
c6f3019a RS |
1669 | /* We found an acceptable shift. Generate a move to |
1670 | take the value from the store and put it into the | |
1671 | shift pseudo, then shift it, then generate another | |
1672 | move to put in into the target of the read. */ | |
18b526e8 | 1673 | emit_move_insn (new_reg, new_lhs); |
c6f3019a | 1674 | emit_insn (shift_seq); |
18b526e8 | 1675 | read_reg = extract_low_bits (read_mode, new_mode, new_reg); |
c6f3019a | 1676 | break; |
8660aaae EC |
1677 | } |
1678 | ||
18b526e8 | 1679 | return read_reg; |
8660aaae EC |
1680 | } |
1681 | ||
1682 | ||
02b47899 KZ |
1683 | /* Call back for note_stores to find the hard regs set or clobbered by |
1684 | insn. Data is a bitmap of the hardregs set so far. */ | |
1685 | ||
1686 | static void | |
1687 | look_for_hardregs (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) | |
1688 | { | |
1689 | bitmap regs_set = (bitmap) data; | |
1690 | ||
1691 | if (REG_P (x) | |
f773c2bd | 1692 | && HARD_REGISTER_P (x)) |
dc8afb70 | 1693 | bitmap_set_range (regs_set, REGNO (x), REG_NREGS (x)); |
02b47899 KZ |
1694 | } |
1695 | ||
8dd5516b JJ |
1696 | /* Helper function for replace_read and record_store. |
1697 | Attempt to return a value stored in STORE_INFO, from READ_BEGIN | |
1698 | to one before READ_END bytes read in READ_MODE. Return NULL | |
1699 | if not successful. If REQUIRE_CST is true, return always constant. */ | |
1700 | ||
1701 | static rtx | |
fd6daec9 | 1702 | get_stored_val (store_info *store_info, machine_mode read_mode, |
8dd5516b JJ |
1703 | HOST_WIDE_INT read_begin, HOST_WIDE_INT read_end, |
1704 | basic_block bb, bool require_cst) | |
1705 | { | |
ef4bddc2 | 1706 | machine_mode store_mode = GET_MODE (store_info->mem); |
8dd5516b JJ |
1707 | int shift; |
1708 | int access_size; /* In bytes. */ | |
1709 | rtx read_reg; | |
1710 | ||
1711 | /* To get here the read is within the boundaries of the write so | |
1712 | shift will never be negative. Start out with the shift being in | |
1713 | bytes. */ | |
1714 | if (store_mode == BLKmode) | |
1715 | shift = 0; | |
1716 | else if (BYTES_BIG_ENDIAN) | |
1717 | shift = store_info->end - read_end; | |
1718 | else | |
1719 | shift = read_begin - store_info->begin; | |
1720 | ||
1721 | access_size = shift + GET_MODE_SIZE (read_mode); | |
1722 | ||
1723 | /* From now on it is bits. */ | |
1724 | shift *= BITS_PER_UNIT; | |
1725 | ||
1726 | if (shift) | |
1727 | read_reg = find_shift_sequence (access_size, store_info, read_mode, shift, | |
1728 | optimize_bb_for_speed_p (bb), | |
1729 | require_cst); | |
1730 | else if (store_mode == BLKmode) | |
1731 | { | |
1732 | /* The store is a memset (addr, const_val, const_size). */ | |
1733 | gcc_assert (CONST_INT_P (store_info->rhs)); | |
1734 | store_mode = int_mode_for_mode (read_mode); | |
1735 | if (store_mode == BLKmode) | |
1736 | read_reg = NULL_RTX; | |
1737 | else if (store_info->rhs == const0_rtx) | |
1738 | read_reg = extract_low_bits (read_mode, store_mode, const0_rtx); | |
1739 | else if (GET_MODE_BITSIZE (store_mode) > HOST_BITS_PER_WIDE_INT | |
1740 | || BITS_PER_UNIT >= HOST_BITS_PER_WIDE_INT) | |
1741 | read_reg = NULL_RTX; | |
1742 | else | |
1743 | { | |
1744 | unsigned HOST_WIDE_INT c | |
1745 | = INTVAL (store_info->rhs) | |
fecfbfa4 | 1746 | & ((HOST_WIDE_INT_1 << BITS_PER_UNIT) - 1); |
8dd5516b JJ |
1747 | int shift = BITS_PER_UNIT; |
1748 | while (shift < HOST_BITS_PER_WIDE_INT) | |
1749 | { | |
1750 | c |= (c << shift); | |
1751 | shift <<= 1; | |
1752 | } | |
6d26322f | 1753 | read_reg = gen_int_mode (c, store_mode); |
8dd5516b JJ |
1754 | read_reg = extract_low_bits (read_mode, store_mode, read_reg); |
1755 | } | |
1756 | } | |
1757 | else if (store_info->const_rhs | |
1758 | && (require_cst | |
1759 | || GET_MODE_CLASS (read_mode) != GET_MODE_CLASS (store_mode))) | |
1760 | read_reg = extract_low_bits (read_mode, store_mode, | |
1761 | copy_rtx (store_info->const_rhs)); | |
1762 | else | |
1763 | read_reg = extract_low_bits (read_mode, store_mode, | |
1764 | copy_rtx (store_info->rhs)); | |
1765 | if (require_cst && read_reg && !CONSTANT_P (read_reg)) | |
1766 | read_reg = NULL_RTX; | |
1767 | return read_reg; | |
1768 | } | |
02b47899 | 1769 | |
6fb5fa3c DB |
1770 | /* Take a sequence of: |
1771 | A <- r1 | |
1772 | ... | |
1773 | ... <- A | |
1774 | ||
b8698a0f | 1775 | and change it into |
6fb5fa3c DB |
1776 | r2 <- r1 |
1777 | A <- r1 | |
1778 | ... | |
1779 | ... <- r2 | |
1780 | ||
8660aaae EC |
1781 | or |
1782 | ||
1783 | r3 <- extract (r1) | |
1784 | r3 <- r3 >> shift | |
1785 | r2 <- extract (r3) | |
1786 | ... <- r2 | |
1787 | ||
1788 | or | |
1789 | ||
1790 | r2 <- extract (r1) | |
1791 | ... <- r2 | |
1792 | ||
1793 | Depending on the alignment and the mode of the store and | |
1794 | subsequent load. | |
1795 | ||
1796 | ||
1797 | The STORE_INFO and STORE_INSN are for the store and READ_INFO | |
6fb5fa3c DB |
1798 | and READ_INSN are for the read. Return true if the replacement |
1799 | went ok. */ | |
1800 | ||
1801 | static bool | |
fd6daec9 | 1802 | replace_read (store_info *store_info, insn_info_t store_insn, |
8dd5516b JJ |
1803 | read_info_t read_info, insn_info_t read_insn, rtx *loc, |
1804 | bitmap regs_live) | |
6fb5fa3c | 1805 | { |
ef4bddc2 RS |
1806 | machine_mode store_mode = GET_MODE (store_info->mem); |
1807 | machine_mode read_mode = GET_MODE (read_info->mem); | |
dc01c3d1 DM |
1808 | rtx_insn *insns, *this_insn; |
1809 | rtx read_reg; | |
8dd5516b | 1810 | basic_block bb; |
8660aaae | 1811 | |
6fb5fa3c DB |
1812 | if (!dbg_cnt (dse)) |
1813 | return false; | |
1814 | ||
18b526e8 RS |
1815 | /* Create a sequence of instructions to set up the read register. |
1816 | This sequence goes immediately before the store and its result | |
1817 | is read by the load. | |
1818 | ||
1819 | We need to keep this in perspective. We are replacing a read | |
8660aaae EC |
1820 | with a sequence of insns, but the read will almost certainly be |
1821 | in cache, so it is not going to be an expensive one. Thus, we | |
1822 | are not willing to do a multi insn shift or worse a subroutine | |
1823 | call to get rid of the read. */ | |
456610d3 | 1824 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1825 | fprintf (dump_file, "trying to replace %smode load in insn %d" |
1826 | " from %smode store in insn %d\n", | |
1827 | GET_MODE_NAME (read_mode), INSN_UID (read_insn->insn), | |
1828 | GET_MODE_NAME (store_mode), INSN_UID (store_insn->insn)); | |
1829 | start_sequence (); | |
8dd5516b JJ |
1830 | bb = BLOCK_FOR_INSN (read_insn->insn); |
1831 | read_reg = get_stored_val (store_info, | |
1832 | read_mode, read_info->begin, read_info->end, | |
1833 | bb, false); | |
18b526e8 | 1834 | if (read_reg == NULL_RTX) |
8660aaae | 1835 | { |
18b526e8 | 1836 | end_sequence (); |
456610d3 | 1837 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1838 | fprintf (dump_file, " -- could not extract bits of stored value\n"); |
1839 | return false; | |
8660aaae | 1840 | } |
18b526e8 RS |
1841 | /* Force the value into a new register so that it won't be clobbered |
1842 | between the store and the load. */ | |
1843 | read_reg = copy_to_mode_reg (read_mode, read_reg); | |
1844 | insns = get_insns (); | |
1845 | end_sequence (); | |
8660aaae | 1846 | |
02b47899 KZ |
1847 | if (insns != NULL_RTX) |
1848 | { | |
1849 | /* Now we have to scan the set of new instructions to see if the | |
1850 | sequence contains and sets of hardregs that happened to be | |
1851 | live at this point. For instance, this can happen if one of | |
1852 | the insns sets the CC and the CC happened to be live at that | |
1853 | point. This does occasionally happen, see PR 37922. */ | |
3f9b14ff | 1854 | bitmap regs_set = BITMAP_ALLOC (®_obstack); |
02b47899 KZ |
1855 | |
1856 | for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn)) | |
1857 | note_stores (PATTERN (this_insn), look_for_hardregs, regs_set); | |
b8698a0f | 1858 | |
02b47899 KZ |
1859 | bitmap_and_into (regs_set, regs_live); |
1860 | if (!bitmap_empty_p (regs_set)) | |
1861 | { | |
456610d3 | 1862 | if (dump_file && (dump_flags & TDF_DETAILS)) |
02b47899 | 1863 | { |
b8698a0f | 1864 | fprintf (dump_file, |
02b47899 KZ |
1865 | "abandoning replacement because sequence clobbers live hardregs:"); |
1866 | df_print_regset (dump_file, regs_set); | |
1867 | } | |
b8698a0f | 1868 | |
02b47899 KZ |
1869 | BITMAP_FREE (regs_set); |
1870 | return false; | |
1871 | } | |
1872 | BITMAP_FREE (regs_set); | |
1873 | } | |
1874 | ||
8660aaae | 1875 | if (validate_change (read_insn->insn, loc, read_reg, 0)) |
6fb5fa3c | 1876 | { |
fd6daec9 | 1877 | deferred_change *change = deferred_change_pool.allocate (); |
b8698a0f | 1878 | |
8660aaae EC |
1879 | /* Insert this right before the store insn where it will be safe |
1880 | from later insns that might change it before the read. */ | |
1881 | emit_insn_before (insns, store_insn->insn); | |
b8698a0f | 1882 | |
8660aaae EC |
1883 | /* And now for the kludge part: cselib croaks if you just |
1884 | return at this point. There are two reasons for this: | |
b8698a0f | 1885 | |
8660aaae EC |
1886 | 1) Cselib has an idea of how many pseudos there are and |
1887 | that does not include the new ones we just added. | |
b8698a0f | 1888 | |
8660aaae EC |
1889 | 2) Cselib does not know about the move insn we added |
1890 | above the store_info, and there is no way to tell it | |
1891 | about it, because it has "moved on". | |
b8698a0f | 1892 | |
8660aaae EC |
1893 | Problem (1) is fixable with a certain amount of engineering. |
1894 | Problem (2) is requires starting the bb from scratch. This | |
1895 | could be expensive. | |
b8698a0f | 1896 | |
8660aaae EC |
1897 | So we are just going to have to lie. The move/extraction |
1898 | insns are not really an issue, cselib did not see them. But | |
1899 | the use of the new pseudo read_insn is a real problem because | |
1900 | cselib has not scanned this insn. The way that we solve this | |
1901 | problem is that we are just going to put the mem back for now | |
1902 | and when we are finished with the block, we undo this. We | |
1903 | keep a table of mems to get rid of. At the end of the basic | |
1904 | block we can put them back. */ | |
b8698a0f | 1905 | |
8660aaae | 1906 | *loc = read_info->mem; |
da6603c6 ML |
1907 | change->next = deferred_change_list; |
1908 | deferred_change_list = change; | |
1909 | change->loc = loc; | |
1910 | change->reg = read_reg; | |
b8698a0f | 1911 | |
8660aaae EC |
1912 | /* Get rid of the read_info, from the point of view of the |
1913 | rest of dse, play like this read never happened. */ | |
1914 | read_insn->read_rec = read_info->next; | |
fb0b2914 | 1915 | read_info_type_pool.remove (read_info); |
456610d3 | 1916 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1917 | { |
1918 | fprintf (dump_file, " -- replaced the loaded MEM with "); | |
1919 | print_simple_rtl (dump_file, read_reg); | |
1920 | fprintf (dump_file, "\n"); | |
1921 | } | |
8660aaae | 1922 | return true; |
6fb5fa3c | 1923 | } |
b8698a0f | 1924 | else |
6fb5fa3c | 1925 | { |
456610d3 | 1926 | if (dump_file && (dump_flags & TDF_DETAILS)) |
18b526e8 RS |
1927 | { |
1928 | fprintf (dump_file, " -- replacing the loaded MEM with "); | |
1929 | print_simple_rtl (dump_file, read_reg); | |
1930 | fprintf (dump_file, " led to an invalid instruction\n"); | |
1931 | } | |
6fb5fa3c DB |
1932 | return false; |
1933 | } | |
1934 | } | |
1935 | ||
d7111da8 RS |
1936 | /* Check the address of MEM *LOC and kill any appropriate stores that may |
1937 | be active. */ | |
6fb5fa3c | 1938 | |
d7111da8 RS |
1939 | static void |
1940 | check_mem_read_rtx (rtx *loc, bb_info_t bb_info) | |
6fb5fa3c | 1941 | { |
6216f94e | 1942 | rtx mem = *loc, mem_addr; |
6fb5fa3c DB |
1943 | insn_info_t insn_info; |
1944 | HOST_WIDE_INT offset = 0; | |
1945 | HOST_WIDE_INT width = 0; | |
b8698a0f | 1946 | cselib_val *base = NULL; |
6fb5fa3c DB |
1947 | int group_id; |
1948 | read_info_t read_info; | |
1949 | ||
6fb5fa3c DB |
1950 | insn_info = bb_info->last_insn; |
1951 | ||
1952 | if ((MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
1953 | || (MEM_VOLATILE_P (mem))) | |
1954 | { | |
456610d3 | 1955 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1956 | fprintf (dump_file, " adding wild read, volatile or barrier.\n"); |
1957 | add_wild_read (bb_info); | |
1958 | insn_info->cannot_delete = true; | |
d7111da8 | 1959 | return; |
6fb5fa3c DB |
1960 | } |
1961 | ||
1962 | /* If it is reading readonly mem, then there can be no conflict with | |
1963 | another write. */ | |
1964 | if (MEM_READONLY_P (mem)) | |
d7111da8 | 1965 | return; |
6fb5fa3c | 1966 | |
ac6929b5 | 1967 | if (!canon_address (mem, &group_id, &offset, &base)) |
6fb5fa3c | 1968 | { |
456610d3 | 1969 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
1970 | fprintf (dump_file, " adding wild read, canon_address failure.\n"); |
1971 | add_wild_read (bb_info); | |
d7111da8 | 1972 | return; |
6fb5fa3c DB |
1973 | } |
1974 | ||
1975 | if (GET_MODE (mem) == BLKmode) | |
1976 | width = -1; | |
1977 | else | |
1978 | width = GET_MODE_SIZE (GET_MODE (mem)); | |
1979 | ||
fb0b2914 | 1980 | read_info = read_info_type_pool.allocate (); |
6fb5fa3c DB |
1981 | read_info->group_id = group_id; |
1982 | read_info->mem = mem; | |
6fb5fa3c DB |
1983 | read_info->begin = offset; |
1984 | read_info->end = offset + width; | |
1985 | read_info->next = insn_info->read_rec; | |
1986 | insn_info->read_rec = read_info; | |
ac6929b5 RB |
1987 | if (group_id < 0) |
1988 | mem_addr = base->val_rtx; | |
6216f94e JJ |
1989 | else |
1990 | { | |
ac6929b5 RB |
1991 | group_info *group = rtx_group_vec[group_id]; |
1992 | mem_addr = group->canon_base_addr; | |
6216f94e | 1993 | } |
ac6929b5 RB |
1994 | if (offset) |
1995 | mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset); | |
6fb5fa3c | 1996 | |
ac6929b5 | 1997 | if (group_id >= 0) |
6fb5fa3c DB |
1998 | { |
1999 | /* This is the restricted case where the base is a constant or | |
2000 | the frame pointer and offset is a constant. */ | |
2001 | insn_info_t i_ptr = active_local_stores; | |
2002 | insn_info_t last = NULL; | |
b8698a0f | 2003 | |
456610d3 | 2004 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2005 | { |
2006 | if (width == -1) | |
2007 | fprintf (dump_file, " processing const load gid=%d[BLK]\n", | |
2008 | group_id); | |
2009 | else | |
2010 | fprintf (dump_file, " processing const load gid=%d[%d..%d)\n", | |
2011 | group_id, (int)offset, (int)(offset+width)); | |
2012 | } | |
2013 | ||
2014 | while (i_ptr) | |
2015 | { | |
2016 | bool remove = false; | |
fd6daec9 | 2017 | store_info *store_info = i_ptr->store_rec; |
b8698a0f | 2018 | |
6fb5fa3c DB |
2019 | /* Skip the clobbers. */ |
2020 | while (!store_info->is_set) | |
2021 | store_info = store_info->next; | |
b8698a0f | 2022 | |
6fb5fa3c DB |
2023 | /* There are three cases here. */ |
2024 | if (store_info->group_id < 0) | |
2025 | /* We have a cselib store followed by a read from a | |
2026 | const base. */ | |
b8698a0f L |
2027 | remove |
2028 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2029 | GET_MODE (store_info->mem), |
2030 | store_info->mem_addr, | |
53d9622b | 2031 | mem, mem_addr); |
b8698a0f | 2032 | |
6fb5fa3c DB |
2033 | else if (group_id == store_info->group_id) |
2034 | { | |
2035 | /* This is a block mode load. We may get lucky and | |
2036 | canon_true_dependence may save the day. */ | |
2037 | if (width == -1) | |
b8698a0f L |
2038 | remove |
2039 | = canon_true_dependence (store_info->mem, | |
6fb5fa3c DB |
2040 | GET_MODE (store_info->mem), |
2041 | store_info->mem_addr, | |
53d9622b | 2042 | mem, mem_addr); |
b8698a0f | 2043 | |
6fb5fa3c DB |
2044 | /* If this read is just reading back something that we just |
2045 | stored, rewrite the read. */ | |
b8698a0f | 2046 | else |
6fb5fa3c DB |
2047 | { |
2048 | if (store_info->rhs | |
8dd5516b JJ |
2049 | && offset >= store_info->begin |
2050 | && offset + width <= store_info->end | |
2051 | && all_positions_needed_p (store_info, | |
2052 | offset - store_info->begin, | |
2053 | width) | |
2054 | && replace_read (store_info, i_ptr, read_info, | |
2055 | insn_info, loc, bb_info->regs_live)) | |
d7111da8 | 2056 | return; |
8dd5516b | 2057 | |
6fb5fa3c DB |
2058 | /* The bases are the same, just see if the offsets |
2059 | overlap. */ | |
b8698a0f | 2060 | if ((offset < store_info->end) |
6fb5fa3c DB |
2061 | && (offset + width > store_info->begin)) |
2062 | remove = true; | |
2063 | } | |
2064 | } | |
b8698a0f L |
2065 | |
2066 | /* else | |
6fb5fa3c DB |
2067 | The else case that is missing here is that the |
2068 | bases are constant but different. There is nothing | |
2069 | to do here because there is no overlap. */ | |
b8698a0f | 2070 | |
6fb5fa3c DB |
2071 | if (remove) |
2072 | { | |
456610d3 | 2073 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2074 | dump_insn_info ("removing from active", i_ptr); |
2075 | ||
dabd47e7 | 2076 | active_local_stores_len--; |
6fb5fa3c DB |
2077 | if (last) |
2078 | last->next_local_store = i_ptr->next_local_store; | |
2079 | else | |
2080 | active_local_stores = i_ptr->next_local_store; | |
2081 | } | |
2082 | else | |
2083 | last = i_ptr; | |
2084 | i_ptr = i_ptr->next_local_store; | |
2085 | } | |
2086 | } | |
b8698a0f | 2087 | else |
6fb5fa3c DB |
2088 | { |
2089 | insn_info_t i_ptr = active_local_stores; | |
2090 | insn_info_t last = NULL; | |
456610d3 | 2091 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2092 | { |
2093 | fprintf (dump_file, " processing cselib load mem:"); | |
2094 | print_inline_rtx (dump_file, mem, 0); | |
2095 | fprintf (dump_file, "\n"); | |
2096 | } | |
2097 | ||
2098 | while (i_ptr) | |
2099 | { | |
2100 | bool remove = false; | |
fd6daec9 | 2101 | store_info *store_info = i_ptr->store_rec; |
b8698a0f | 2102 | |
456610d3 | 2103 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2104 | fprintf (dump_file, " processing cselib load against insn %d\n", |
2105 | INSN_UID (i_ptr->insn)); | |
2106 | ||
2107 | /* Skip the clobbers. */ | |
2108 | while (!store_info->is_set) | |
2109 | store_info = store_info->next; | |
2110 | ||
2111 | /* If this read is just reading back something that we just | |
2112 | stored, rewrite the read. */ | |
2113 | if (store_info->rhs | |
2114 | && store_info->group_id == -1 | |
2115 | && store_info->cse_base == base | |
efc3527a | 2116 | && width != -1 |
8dd5516b JJ |
2117 | && offset >= store_info->begin |
2118 | && offset + width <= store_info->end | |
2119 | && all_positions_needed_p (store_info, | |
2120 | offset - store_info->begin, width) | |
2121 | && replace_read (store_info, i_ptr, read_info, insn_info, loc, | |
2122 | bb_info->regs_live)) | |
d7111da8 | 2123 | return; |
6fb5fa3c | 2124 | |
ac6929b5 RB |
2125 | remove = canon_true_dependence (store_info->mem, |
2126 | GET_MODE (store_info->mem), | |
2127 | store_info->mem_addr, | |
2128 | mem, mem_addr); | |
b8698a0f | 2129 | |
6fb5fa3c DB |
2130 | if (remove) |
2131 | { | |
456610d3 | 2132 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2133 | dump_insn_info ("removing from active", i_ptr); |
b8698a0f | 2134 | |
dabd47e7 | 2135 | active_local_stores_len--; |
6fb5fa3c DB |
2136 | if (last) |
2137 | last->next_local_store = i_ptr->next_local_store; | |
2138 | else | |
2139 | active_local_stores = i_ptr->next_local_store; | |
2140 | } | |
2141 | else | |
2142 | last = i_ptr; | |
2143 | i_ptr = i_ptr->next_local_store; | |
2144 | } | |
2145 | } | |
6fb5fa3c DB |
2146 | } |
2147 | ||
d7111da8 | 2148 | /* A note_uses callback in which DATA points the INSN_INFO for |
6fb5fa3c DB |
2149 | as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns |
2150 | true for any part of *LOC. */ | |
2151 | ||
2152 | static void | |
2153 | check_mem_read_use (rtx *loc, void *data) | |
2154 | { | |
d7111da8 RS |
2155 | subrtx_ptr_iterator::array_type array; |
2156 | FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST) | |
2157 | { | |
2158 | rtx *loc = *iter; | |
2159 | if (MEM_P (*loc)) | |
2160 | check_mem_read_rtx (loc, (bb_info_t) data); | |
2161 | } | |
6fb5fa3c DB |
2162 | } |
2163 | ||
8dd5516b JJ |
2164 | |
2165 | /* Get arguments passed to CALL_INSN. Return TRUE if successful. | |
2166 | So far it only handles arguments passed in registers. */ | |
2167 | ||
2168 | static bool | |
2169 | get_call_args (rtx call_insn, tree fn, rtx *args, int nargs) | |
2170 | { | |
d5cc9181 JR |
2171 | CUMULATIVE_ARGS args_so_far_v; |
2172 | cumulative_args_t args_so_far; | |
8dd5516b JJ |
2173 | tree arg; |
2174 | int idx; | |
2175 | ||
d5cc9181 JR |
2176 | INIT_CUMULATIVE_ARGS (args_so_far_v, TREE_TYPE (fn), NULL_RTX, 0, 3); |
2177 | args_so_far = pack_cumulative_args (&args_so_far_v); | |
8dd5516b JJ |
2178 | |
2179 | arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2180 | for (idx = 0; | |
2181 | arg != void_list_node && idx < nargs; | |
2182 | arg = TREE_CHAIN (arg), idx++) | |
2183 | { | |
ef4bddc2 | 2184 | machine_mode mode = TYPE_MODE (TREE_VALUE (arg)); |
3c07301f | 2185 | rtx reg, link, tmp; |
d5cc9181 | 2186 | reg = targetm.calls.function_arg (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2187 | if (!reg || !REG_P (reg) || GET_MODE (reg) != mode |
2188 | || GET_MODE_CLASS (mode) != MODE_INT) | |
2189 | return false; | |
2190 | ||
2191 | for (link = CALL_INSN_FUNCTION_USAGE (call_insn); | |
2192 | link; | |
2193 | link = XEXP (link, 1)) | |
2194 | if (GET_CODE (XEXP (link, 0)) == USE) | |
2195 | { | |
2196 | args[idx] = XEXP (XEXP (link, 0), 0); | |
2197 | if (REG_P (args[idx]) | |
2198 | && REGNO (args[idx]) == REGNO (reg) | |
2199 | && (GET_MODE (args[idx]) == mode | |
2200 | || (GET_MODE_CLASS (GET_MODE (args[idx])) == MODE_INT | |
2201 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2202 | <= UNITS_PER_WORD) | |
2203 | && (GET_MODE_SIZE (GET_MODE (args[idx])) | |
2204 | > GET_MODE_SIZE (mode))))) | |
2205 | break; | |
2206 | } | |
2207 | if (!link) | |
2208 | return false; | |
2209 | ||
2210 | tmp = cselib_expand_value_rtx (args[idx], scratch, 5); | |
2211 | if (GET_MODE (args[idx]) != mode) | |
2212 | { | |
2213 | if (!tmp || !CONST_INT_P (tmp)) | |
2214 | return false; | |
6d26322f | 2215 | tmp = gen_int_mode (INTVAL (tmp), mode); |
8dd5516b JJ |
2216 | } |
2217 | if (tmp) | |
2218 | args[idx] = tmp; | |
2219 | ||
d5cc9181 | 2220 | targetm.calls.function_arg_advance (args_so_far, mode, NULL_TREE, true); |
8dd5516b JJ |
2221 | } |
2222 | if (arg != void_list_node || idx != nargs) | |
2223 | return false; | |
2224 | return true; | |
2225 | } | |
2226 | ||
9e582b1d JR |
2227 | /* Return a bitmap of the fixed registers contained in IN. */ |
2228 | ||
2229 | static bitmap | |
2230 | copy_fixed_regs (const_bitmap in) | |
2231 | { | |
2232 | bitmap ret; | |
2233 | ||
2234 | ret = ALLOC_REG_SET (NULL); | |
2235 | bitmap_and (ret, in, fixed_reg_set_regset); | |
2236 | return ret; | |
2237 | } | |
8dd5516b | 2238 | |
6fb5fa3c DB |
2239 | /* Apply record_store to all candidate stores in INSN. Mark INSN |
2240 | if some part of it is not a candidate store and assigns to a | |
2241 | non-register target. */ | |
2242 | ||
2243 | static void | |
dd60a84c | 2244 | scan_insn (bb_info_t bb_info, rtx_insn *insn) |
6fb5fa3c DB |
2245 | { |
2246 | rtx body; | |
fb0b2914 | 2247 | insn_info_type *insn_info = insn_info_type_pool.allocate (); |
6fb5fa3c | 2248 | int mems_found = 0; |
da6603c6 | 2249 | memset (insn_info, 0, sizeof (struct insn_info_type)); |
6fb5fa3c | 2250 | |
456610d3 | 2251 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
2252 | fprintf (dump_file, "\n**scanning insn=%d\n", |
2253 | INSN_UID (insn)); | |
2254 | ||
2255 | insn_info->prev_insn = bb_info->last_insn; | |
2256 | insn_info->insn = insn; | |
2257 | bb_info->last_insn = insn_info; | |
b8698a0f | 2258 | |
b5b8b0ac AO |
2259 | if (DEBUG_INSN_P (insn)) |
2260 | { | |
2261 | insn_info->cannot_delete = true; | |
2262 | return; | |
2263 | } | |
6fb5fa3c | 2264 | |
6fb5fa3c DB |
2265 | /* Look at all of the uses in the insn. */ |
2266 | note_uses (&PATTERN (insn), check_mem_read_use, bb_info); | |
2267 | ||
2268 | if (CALL_P (insn)) | |
2269 | { | |
8dd5516b | 2270 | bool const_call; |
ee516de9 | 2271 | rtx call, sym; |
8dd5516b JJ |
2272 | tree memset_call = NULL_TREE; |
2273 | ||
6fb5fa3c | 2274 | insn_info->cannot_delete = true; |
50f0f366 | 2275 | |
6fb5fa3c | 2276 | /* Const functions cannot do anything bad i.e. read memory, |
50f0f366 | 2277 | however, they can read their parameters which may have |
8dd5516b JJ |
2278 | been pushed onto the stack. |
2279 | memset and bzero don't read memory either. */ | |
2280 | const_call = RTL_CONST_CALL_P (insn); | |
ee516de9 EB |
2281 | if (!const_call |
2282 | && (call = get_call_rtx_from (insn)) | |
2283 | && (sym = XEXP (XEXP (call, 0), 0)) | |
2284 | && GET_CODE (sym) == SYMBOL_REF | |
2285 | && SYMBOL_REF_DECL (sym) | |
2286 | && TREE_CODE (SYMBOL_REF_DECL (sym)) == FUNCTION_DECL | |
2287 | && DECL_BUILT_IN_CLASS (SYMBOL_REF_DECL (sym)) == BUILT_IN_NORMAL | |
2288 | && DECL_FUNCTION_CODE (SYMBOL_REF_DECL (sym)) == BUILT_IN_MEMSET) | |
2289 | memset_call = SYMBOL_REF_DECL (sym); | |
2290 | ||
8dd5516b | 2291 | if (const_call || memset_call) |
6fb5fa3c DB |
2292 | { |
2293 | insn_info_t i_ptr = active_local_stores; | |
2294 | insn_info_t last = NULL; | |
2295 | ||
456610d3 | 2296 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2297 | fprintf (dump_file, "%s call %d\n", |
2298 | const_call ? "const" : "memset", INSN_UID (insn)); | |
6fb5fa3c | 2299 | |
64520bdc | 2300 | /* See the head comment of the frame_read field. */ |
57534689 JJ |
2301 | if (reload_completed |
2302 | /* Tail calls are storing their arguments using | |
2303 | arg pointer. If it is a frame pointer on the target, | |
2304 | even before reload we need to kill frame pointer based | |
2305 | stores. */ | |
2306 | || (SIBLING_CALL_P (insn) | |
2307 | && HARD_FRAME_POINTER_IS_ARG_POINTER)) | |
64520bdc EB |
2308 | insn_info->frame_read = true; |
2309 | ||
2310 | /* Loop over the active stores and remove those which are | |
2311 | killed by the const function call. */ | |
6fb5fa3c DB |
2312 | while (i_ptr) |
2313 | { | |
64520bdc EB |
2314 | bool remove_store = false; |
2315 | ||
2316 | /* The stack pointer based stores are always killed. */ | |
50f0f366 | 2317 | if (i_ptr->stack_pointer_based) |
64520bdc EB |
2318 | remove_store = true; |
2319 | ||
2320 | /* If the frame is read, the frame related stores are killed. */ | |
2321 | else if (insn_info->frame_read) | |
2322 | { | |
fd6daec9 | 2323 | store_info *store_info = i_ptr->store_rec; |
64520bdc EB |
2324 | |
2325 | /* Skip the clobbers. */ | |
2326 | while (!store_info->is_set) | |
2327 | store_info = store_info->next; | |
2328 | ||
2329 | if (store_info->group_id >= 0 | |
9771b263 | 2330 | && rtx_group_vec[store_info->group_id]->frame_related) |
64520bdc EB |
2331 | remove_store = true; |
2332 | } | |
2333 | ||
2334 | if (remove_store) | |
6fb5fa3c | 2335 | { |
456610d3 | 2336 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2337 | dump_insn_info ("removing from active", i_ptr); |
b8698a0f | 2338 | |
dabd47e7 | 2339 | active_local_stores_len--; |
6fb5fa3c DB |
2340 | if (last) |
2341 | last->next_local_store = i_ptr->next_local_store; | |
2342 | else | |
2343 | active_local_stores = i_ptr->next_local_store; | |
2344 | } | |
2345 | else | |
2346 | last = i_ptr; | |
64520bdc | 2347 | |
6fb5fa3c DB |
2348 | i_ptr = i_ptr->next_local_store; |
2349 | } | |
8dd5516b JJ |
2350 | |
2351 | if (memset_call) | |
2352 | { | |
2353 | rtx args[3]; | |
2354 | if (get_call_args (insn, memset_call, args, 3) | |
2355 | && CONST_INT_P (args[1]) | |
2356 | && CONST_INT_P (args[2]) | |
2357 | && INTVAL (args[2]) > 0) | |
2358 | { | |
2359 | rtx mem = gen_rtx_MEM (BLKmode, args[0]); | |
f5541398 | 2360 | set_mem_size (mem, INTVAL (args[2])); |
f7df4a84 | 2361 | body = gen_rtx_SET (mem, args[1]); |
8dd5516b | 2362 | mems_found += record_store (body, bb_info); |
456610d3 | 2363 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2364 | fprintf (dump_file, "handling memset as BLKmode store\n"); |
2365 | if (mems_found == 1) | |
2366 | { | |
dabd47e7 JJ |
2367 | if (active_local_stores_len++ |
2368 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2369 | { | |
2370 | active_local_stores_len = 1; | |
2371 | active_local_stores = NULL; | |
2372 | } | |
9e582b1d JR |
2373 | insn_info->fixed_regs_live |
2374 | = copy_fixed_regs (bb_info->regs_live); | |
8dd5516b JJ |
2375 | insn_info->next_local_store = active_local_stores; |
2376 | active_local_stores = insn_info; | |
2377 | } | |
2378 | } | |
a2ad54a0 JJ |
2379 | else |
2380 | clear_rhs_from_active_local_stores (); | |
8dd5516b | 2381 | } |
6fb5fa3c | 2382 | } |
57534689 JJ |
2383 | else if (SIBLING_CALL_P (insn) && reload_completed) |
2384 | /* Arguments for a sibling call that are pushed to memory are passed | |
2385 | using the incoming argument pointer of the current function. After | |
2386 | reload that might be (and likely is) frame pointer based. */ | |
2387 | add_wild_read (bb_info); | |
50f0f366 | 2388 | else |
d26c7090 ER |
2389 | /* Every other call, including pure functions, may read any memory |
2390 | that is not relative to the frame. */ | |
2391 | add_non_frame_wild_read (bb_info); | |
50f0f366 | 2392 | |
6fb5fa3c DB |
2393 | return; |
2394 | } | |
2395 | ||
2396 | /* Assuming that there are sets in these insns, we cannot delete | |
2397 | them. */ | |
2398 | if ((GET_CODE (PATTERN (insn)) == CLOBBER) | |
0a64eeca | 2399 | || volatile_refs_p (PATTERN (insn)) |
2da02156 | 2400 | || (!cfun->can_delete_dead_exceptions && !insn_nothrow_p (insn)) |
6fb5fa3c DB |
2401 | || (RTX_FRAME_RELATED_P (insn)) |
2402 | || find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX)) | |
2403 | insn_info->cannot_delete = true; | |
b8698a0f | 2404 | |
6fb5fa3c DB |
2405 | body = PATTERN (insn); |
2406 | if (GET_CODE (body) == PARALLEL) | |
2407 | { | |
2408 | int i; | |
2409 | for (i = 0; i < XVECLEN (body, 0); i++) | |
2410 | mems_found += record_store (XVECEXP (body, 0, i), bb_info); | |
2411 | } | |
2412 | else | |
2413 | mems_found += record_store (body, bb_info); | |
2414 | ||
456610d3 | 2415 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 2416 | fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n", |
6fb5fa3c DB |
2417 | mems_found, insn_info->cannot_delete ? "true" : "false"); |
2418 | ||
8dd5516b JJ |
2419 | /* If we found some sets of mems, add it into the active_local_stores so |
2420 | that it can be locally deleted if found dead or used for | |
2421 | replace_read and redundant constant store elimination. Otherwise mark | |
2422 | it as cannot delete. This simplifies the processing later. */ | |
2423 | if (mems_found == 1) | |
6fb5fa3c | 2424 | { |
dabd47e7 JJ |
2425 | if (active_local_stores_len++ |
2426 | >= PARAM_VALUE (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)) | |
2427 | { | |
2428 | active_local_stores_len = 1; | |
2429 | active_local_stores = NULL; | |
2430 | } | |
9e582b1d | 2431 | insn_info->fixed_regs_live = copy_fixed_regs (bb_info->regs_live); |
6fb5fa3c DB |
2432 | insn_info->next_local_store = active_local_stores; |
2433 | active_local_stores = insn_info; | |
2434 | } | |
2435 | else | |
2436 | insn_info->cannot_delete = true; | |
2437 | } | |
2438 | ||
2439 | ||
2440 | /* Remove BASE from the set of active_local_stores. This is a | |
2441 | callback from cselib that is used to get rid of the stores in | |
2442 | active_local_stores. */ | |
2443 | ||
2444 | static void | |
2445 | remove_useless_values (cselib_val *base) | |
2446 | { | |
2447 | insn_info_t insn_info = active_local_stores; | |
2448 | insn_info_t last = NULL; | |
2449 | ||
2450 | while (insn_info) | |
2451 | { | |
fd6daec9 | 2452 | store_info *store_info = insn_info->store_rec; |
60564289 | 2453 | bool del = false; |
6fb5fa3c DB |
2454 | |
2455 | /* If ANY of the store_infos match the cselib group that is | |
2456 | being deleted, then the insn can not be deleted. */ | |
2457 | while (store_info) | |
2458 | { | |
b8698a0f | 2459 | if ((store_info->group_id == -1) |
6fb5fa3c DB |
2460 | && (store_info->cse_base == base)) |
2461 | { | |
60564289 | 2462 | del = true; |
6fb5fa3c DB |
2463 | break; |
2464 | } | |
2465 | store_info = store_info->next; | |
2466 | } | |
2467 | ||
60564289 | 2468 | if (del) |
6fb5fa3c | 2469 | { |
dabd47e7 | 2470 | active_local_stores_len--; |
6fb5fa3c DB |
2471 | if (last) |
2472 | last->next_local_store = insn_info->next_local_store; | |
2473 | else | |
2474 | active_local_stores = insn_info->next_local_store; | |
2475 | free_store_info (insn_info); | |
2476 | } | |
2477 | else | |
2478 | last = insn_info; | |
b8698a0f | 2479 | |
6fb5fa3c DB |
2480 | insn_info = insn_info->next_local_store; |
2481 | } | |
2482 | } | |
2483 | ||
2484 | ||
2485 | /* Do all of step 1. */ | |
2486 | ||
2487 | static void | |
2488 | dse_step1 (void) | |
2489 | { | |
2490 | basic_block bb; | |
3f9b14ff | 2491 | bitmap regs_live = BITMAP_ALLOC (®_obstack); |
b8698a0f | 2492 | |
457eeaae | 2493 | cselib_init (0); |
6fb5fa3c DB |
2494 | all_blocks = BITMAP_ALLOC (NULL); |
2495 | bitmap_set_bit (all_blocks, ENTRY_BLOCK); | |
2496 | bitmap_set_bit (all_blocks, EXIT_BLOCK); | |
2497 | ||
04a90bec | 2498 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
2499 | { |
2500 | insn_info_t ptr; | |
fb0b2914 | 2501 | bb_info_t bb_info = dse_bb_info_type_pool.allocate (); |
6fb5fa3c | 2502 | |
da6603c6 | 2503 | memset (bb_info, 0, sizeof (dse_bb_info_type)); |
6fb5fa3c | 2504 | bitmap_set_bit (all_blocks, bb->index); |
02b47899 KZ |
2505 | bb_info->regs_live = regs_live; |
2506 | ||
2507 | bitmap_copy (regs_live, DF_LR_IN (bb)); | |
2508 | df_simulate_initialize_forwards (bb, regs_live); | |
6fb5fa3c DB |
2509 | |
2510 | bb_table[bb->index] = bb_info; | |
2511 | cselib_discard_hook = remove_useless_values; | |
2512 | ||
2513 | if (bb->index >= NUM_FIXED_BLOCKS) | |
2514 | { | |
dd60a84c | 2515 | rtx_insn *insn; |
6fb5fa3c | 2516 | |
6fb5fa3c | 2517 | active_local_stores = NULL; |
dabd47e7 | 2518 | active_local_stores_len = 0; |
6fb5fa3c | 2519 | cselib_clear_table (); |
b8698a0f | 2520 | |
6fb5fa3c DB |
2521 | /* Scan the insns. */ |
2522 | FOR_BB_INSNS (bb, insn) | |
2523 | { | |
2524 | if (INSN_P (insn)) | |
2525 | scan_insn (bb_info, insn); | |
2526 | cselib_process_insn (insn); | |
02b47899 KZ |
2527 | if (INSN_P (insn)) |
2528 | df_simulate_one_insn_forwards (bb, insn, regs_live); | |
6fb5fa3c | 2529 | } |
b8698a0f | 2530 | |
6fb5fa3c DB |
2531 | /* This is something of a hack, because the global algorithm |
2532 | is supposed to take care of the case where stores go dead | |
2533 | at the end of the function. However, the global | |
2534 | algorithm must take a more conservative view of block | |
2535 | mode reads than the local alg does. So to get the case | |
2536 | where you have a store to the frame followed by a non | |
0d52bcc1 | 2537 | overlapping block more read, we look at the active local |
6fb5fa3c DB |
2538 | stores at the end of the function and delete all of the |
2539 | frame and spill based ones. */ | |
2540 | if (stores_off_frame_dead_at_return | |
2541 | && (EDGE_COUNT (bb->succs) == 0 | |
2542 | || (single_succ_p (bb) | |
fefa31b5 | 2543 | && single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (cfun) |
e3b5732b | 2544 | && ! crtl->calls_eh_return))) |
6fb5fa3c DB |
2545 | { |
2546 | insn_info_t i_ptr = active_local_stores; | |
2547 | while (i_ptr) | |
2548 | { | |
fd6daec9 | 2549 | store_info *store_info = i_ptr->store_rec; |
6fb5fa3c DB |
2550 | |
2551 | /* Skip the clobbers. */ | |
2552 | while (!store_info->is_set) | |
2553 | store_info = store_info->next; | |
ac6929b5 RB |
2554 | if (store_info->group_id >= 0) |
2555 | { | |
2556 | group_info *group = rtx_group_vec[store_info->group_id]; | |
2557 | if (group->frame_related && !i_ptr->cannot_delete) | |
2558 | delete_dead_store_insn (i_ptr); | |
2559 | } | |
6fb5fa3c DB |
2560 | |
2561 | i_ptr = i_ptr->next_local_store; | |
2562 | } | |
2563 | } | |
2564 | ||
2565 | /* Get rid of the loads that were discovered in | |
2566 | replace_read. Cselib is finished with this block. */ | |
2567 | while (deferred_change_list) | |
2568 | { | |
fd6daec9 | 2569 | deferred_change *next = deferred_change_list->next; |
6fb5fa3c DB |
2570 | |
2571 | /* There is no reason to validate this change. That was | |
2572 | done earlier. */ | |
2573 | *deferred_change_list->loc = deferred_change_list->reg; | |
fb0b2914 | 2574 | deferred_change_pool.remove (deferred_change_list); |
6fb5fa3c DB |
2575 | deferred_change_list = next; |
2576 | } | |
2577 | ||
2578 | /* Get rid of all of the cselib based store_infos in this | |
2579 | block and mark the containing insns as not being | |
2580 | deletable. */ | |
2581 | ptr = bb_info->last_insn; | |
2582 | while (ptr) | |
2583 | { | |
2584 | if (ptr->contains_cselib_groups) | |
8dd5516b | 2585 | { |
fd6daec9 | 2586 | store_info *s_info = ptr->store_rec; |
8dd5516b JJ |
2587 | while (s_info && !s_info->is_set) |
2588 | s_info = s_info->next; | |
2589 | if (s_info | |
2590 | && s_info->redundant_reason | |
2591 | && s_info->redundant_reason->insn | |
2592 | && !ptr->cannot_delete) | |
2593 | { | |
456610d3 | 2594 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
2595 | fprintf (dump_file, "Locally deleting insn %d " |
2596 | "because insn %d stores the " | |
2597 | "same value and couldn't be " | |
2598 | "eliminated\n", | |
2599 | INSN_UID (ptr->insn), | |
2600 | INSN_UID (s_info->redundant_reason->insn)); | |
2601 | delete_dead_store_insn (ptr); | |
2602 | } | |
8dd5516b JJ |
2603 | free_store_info (ptr); |
2604 | } | |
2605 | else | |
2606 | { | |
fd6daec9 | 2607 | store_info *s_info; |
8dd5516b JJ |
2608 | |
2609 | /* Free at least positions_needed bitmaps. */ | |
2610 | for (s_info = ptr->store_rec; s_info; s_info = s_info->next) | |
2611 | if (s_info->is_large) | |
2612 | { | |
dc491a25 | 2613 | BITMAP_FREE (s_info->positions_needed.large.bmap); |
8dd5516b JJ |
2614 | s_info->is_large = false; |
2615 | } | |
2616 | } | |
6fb5fa3c DB |
2617 | ptr = ptr->prev_insn; |
2618 | } | |
2619 | ||
da6603c6 | 2620 | cse_store_info_pool.release (); |
6fb5fa3c | 2621 | } |
02b47899 | 2622 | bb_info->regs_live = NULL; |
6fb5fa3c DB |
2623 | } |
2624 | ||
02b47899 | 2625 | BITMAP_FREE (regs_live); |
6fb5fa3c | 2626 | cselib_finish (); |
c203e8a7 | 2627 | rtx_group_table->empty (); |
6fb5fa3c DB |
2628 | } |
2629 | ||
2630 | \f | |
2631 | /*---------------------------------------------------------------------------- | |
2632 | Second step. | |
2633 | ||
2634 | Assign each byte position in the stores that we are going to | |
2635 | analyze globally to a position in the bitmaps. Returns true if | |
6ed3da00 | 2636 | there are any bit positions assigned. |
6fb5fa3c DB |
2637 | ----------------------------------------------------------------------------*/ |
2638 | ||
2639 | static void | |
2640 | dse_step2_init (void) | |
2641 | { | |
2642 | unsigned int i; | |
fd6daec9 | 2643 | group_info *group; |
6fb5fa3c | 2644 | |
9771b263 | 2645 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2646 | { |
2647 | /* For all non stack related bases, we only consider a store to | |
2648 | be deletable if there are two or more stores for that | |
2649 | position. This is because it takes one store to make the | |
2650 | other store redundant. However, for the stores that are | |
2651 | stack related, we consider them if there is only one store | |
2652 | for the position. We do this because the stack related | |
2653 | stores can be deleted if their is no read between them and | |
2654 | the end of the function. | |
b8698a0f | 2655 | |
6fb5fa3c DB |
2656 | To make this work in the current framework, we take the stack |
2657 | related bases add all of the bits from store1 into store2. | |
2658 | This has the effect of making the eligible even if there is | |
2659 | only one store. */ | |
2660 | ||
2661 | if (stores_off_frame_dead_at_return && group->frame_related) | |
2662 | { | |
2663 | bitmap_ior_into (group->store2_n, group->store1_n); | |
2664 | bitmap_ior_into (group->store2_p, group->store1_p); | |
456610d3 | 2665 | if (dump_file && (dump_flags & TDF_DETAILS)) |
b8698a0f | 2666 | fprintf (dump_file, "group %d is frame related ", i); |
6fb5fa3c DB |
2667 | } |
2668 | ||
2669 | group->offset_map_size_n++; | |
3f9b14ff SB |
2670 | group->offset_map_n = XOBNEWVEC (&dse_obstack, int, |
2671 | group->offset_map_size_n); | |
6fb5fa3c | 2672 | group->offset_map_size_p++; |
3f9b14ff SB |
2673 | group->offset_map_p = XOBNEWVEC (&dse_obstack, int, |
2674 | group->offset_map_size_p); | |
6fb5fa3c | 2675 | group->process_globally = false; |
456610d3 | 2676 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 2677 | { |
b8698a0f | 2678 | fprintf (dump_file, "group %d(%d+%d): ", i, |
6fb5fa3c DB |
2679 | (int)bitmap_count_bits (group->store2_n), |
2680 | (int)bitmap_count_bits (group->store2_p)); | |
2681 | bitmap_print (dump_file, group->store2_n, "n ", " "); | |
2682 | bitmap_print (dump_file, group->store2_p, "p ", "\n"); | |
2683 | } | |
2684 | } | |
2685 | } | |
2686 | ||
2687 | ||
ac6929b5 | 2688 | /* Init the offset tables. */ |
6fb5fa3c DB |
2689 | |
2690 | static bool | |
ac6929b5 | 2691 | dse_step2 (void) |
6fb5fa3c DB |
2692 | { |
2693 | unsigned int i; | |
fd6daec9 | 2694 | group_info *group; |
6fb5fa3c DB |
2695 | /* Position 0 is unused because 0 is used in the maps to mean |
2696 | unused. */ | |
2697 | current_position = 1; | |
9771b263 | 2698 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2699 | { |
2700 | bitmap_iterator bi; | |
2701 | unsigned int j; | |
2702 | ||
c3284718 RS |
2703 | memset (group->offset_map_n, 0, sizeof (int) * group->offset_map_size_n); |
2704 | memset (group->offset_map_p, 0, sizeof (int) * group->offset_map_size_p); | |
6fb5fa3c DB |
2705 | bitmap_clear (group->group_kill); |
2706 | ||
2707 | EXECUTE_IF_SET_IN_BITMAP (group->store2_n, 0, j, bi) | |
2708 | { | |
2709 | bitmap_set_bit (group->group_kill, current_position); | |
d26c7090 ER |
2710 | if (bitmap_bit_p (group->escaped_n, j)) |
2711 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2712 | group->offset_map_n[j] = current_position++; |
2713 | group->process_globally = true; | |
2714 | } | |
2715 | EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi) | |
2716 | { | |
b8698a0f | 2717 | bitmap_set_bit (group->group_kill, current_position); |
d26c7090 ER |
2718 | if (bitmap_bit_p (group->escaped_p, j)) |
2719 | bitmap_set_bit (kill_on_calls, current_position); | |
6fb5fa3c DB |
2720 | group->offset_map_p[j] = current_position++; |
2721 | group->process_globally = true; | |
2722 | } | |
2723 | } | |
2724 | return current_position != 1; | |
2725 | } | |
2726 | ||
2727 | ||
6fb5fa3c DB |
2728 | \f |
2729 | /*---------------------------------------------------------------------------- | |
2730 | Third step. | |
b8698a0f | 2731 | |
6fb5fa3c DB |
2732 | Build the bit vectors for the transfer functions. |
2733 | ----------------------------------------------------------------------------*/ | |
2734 | ||
2735 | ||
6fb5fa3c DB |
2736 | /* Look up the bitmap index for OFFSET in GROUP_INFO. If it is not |
2737 | there, return 0. */ | |
2738 | ||
2739 | static int | |
fd6daec9 | 2740 | get_bitmap_index (group_info *group_info, HOST_WIDE_INT offset) |
6fb5fa3c DB |
2741 | { |
2742 | if (offset < 0) | |
2743 | { | |
2744 | HOST_WIDE_INT offset_p = -offset; | |
2745 | if (offset_p >= group_info->offset_map_size_n) | |
2746 | return 0; | |
2747 | return group_info->offset_map_n[offset_p]; | |
2748 | } | |
2749 | else | |
2750 | { | |
2751 | if (offset >= group_info->offset_map_size_p) | |
2752 | return 0; | |
2753 | return group_info->offset_map_p[offset]; | |
2754 | } | |
2755 | } | |
2756 | ||
2757 | ||
2758 | /* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL | |
2759 | may be NULL. */ | |
2760 | ||
b8698a0f | 2761 | static void |
ac6929b5 | 2762 | scan_stores (store_info *store_info, bitmap gen, bitmap kill) |
6fb5fa3c DB |
2763 | { |
2764 | while (store_info) | |
2765 | { | |
2766 | HOST_WIDE_INT i; | |
fd6daec9 | 2767 | group_info *group_info |
9771b263 | 2768 | = rtx_group_vec[store_info->group_id]; |
6fb5fa3c DB |
2769 | if (group_info->process_globally) |
2770 | for (i = store_info->begin; i < store_info->end; i++) | |
2771 | { | |
2772 | int index = get_bitmap_index (group_info, i); | |
2773 | if (index != 0) | |
2774 | { | |
2775 | bitmap_set_bit (gen, index); | |
2776 | if (kill) | |
2777 | bitmap_clear_bit (kill, index); | |
2778 | } | |
2779 | } | |
2780 | store_info = store_info->next; | |
2781 | } | |
2782 | } | |
2783 | ||
2784 | ||
6fb5fa3c DB |
2785 | /* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL |
2786 | may be NULL. */ | |
2787 | ||
2788 | static void | |
ac6929b5 | 2789 | scan_reads (insn_info_t insn_info, bitmap gen, bitmap kill) |
6fb5fa3c DB |
2790 | { |
2791 | read_info_t read_info = insn_info->read_rec; | |
2792 | int i; | |
fd6daec9 | 2793 | group_info *group; |
6fb5fa3c | 2794 | |
64520bdc EB |
2795 | /* If this insn reads the frame, kill all the frame related stores. */ |
2796 | if (insn_info->frame_read) | |
2797 | { | |
9771b263 | 2798 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
64520bdc EB |
2799 | if (group->process_globally && group->frame_related) |
2800 | { | |
2801 | if (kill) | |
2802 | bitmap_ior_into (kill, group->group_kill); | |
b8698a0f | 2803 | bitmap_and_compl_into (gen, group->group_kill); |
64520bdc EB |
2804 | } |
2805 | } | |
d26c7090 ER |
2806 | if (insn_info->non_frame_wild_read) |
2807 | { | |
2808 | /* Kill all non-frame related stores. Kill all stores of variables that | |
2809 | escape. */ | |
2810 | if (kill) | |
2811 | bitmap_ior_into (kill, kill_on_calls); | |
2812 | bitmap_and_compl_into (gen, kill_on_calls); | |
9771b263 | 2813 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
d26c7090 ER |
2814 | if (group->process_globally && !group->frame_related) |
2815 | { | |
2816 | if (kill) | |
2817 | bitmap_ior_into (kill, group->group_kill); | |
2818 | bitmap_and_compl_into (gen, group->group_kill); | |
2819 | } | |
2820 | } | |
6fb5fa3c DB |
2821 | while (read_info) |
2822 | { | |
9771b263 | 2823 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2824 | { |
2825 | if (group->process_globally) | |
2826 | { | |
2827 | if (i == read_info->group_id) | |
2828 | { | |
2829 | if (read_info->begin > read_info->end) | |
2830 | { | |
2831 | /* Begin > end for block mode reads. */ | |
2832 | if (kill) | |
2833 | bitmap_ior_into (kill, group->group_kill); | |
2834 | bitmap_and_compl_into (gen, group->group_kill); | |
2835 | } | |
2836 | else | |
2837 | { | |
2838 | /* The groups are the same, just process the | |
2839 | offsets. */ | |
2840 | HOST_WIDE_INT j; | |
2841 | for (j = read_info->begin; j < read_info->end; j++) | |
2842 | { | |
2843 | int index = get_bitmap_index (group, j); | |
2844 | if (index != 0) | |
2845 | { | |
2846 | if (kill) | |
2847 | bitmap_set_bit (kill, index); | |
2848 | bitmap_clear_bit (gen, index); | |
2849 | } | |
2850 | } | |
2851 | } | |
2852 | } | |
2853 | else | |
2854 | { | |
2855 | /* The groups are different, if the alias sets | |
2856 | conflict, clear the entire group. We only need | |
2857 | to apply this test if the read_info is a cselib | |
2858 | read. Anything with a constant base cannot alias | |
2859 | something else with a different constant | |
2860 | base. */ | |
2861 | if ((read_info->group_id < 0) | |
b8698a0f | 2862 | && canon_true_dependence (group->base_mem, |
d32f725a | 2863 | GET_MODE (group->base_mem), |
6216f94e | 2864 | group->canon_base_addr, |
53d9622b | 2865 | read_info->mem, NULL_RTX)) |
6fb5fa3c DB |
2866 | { |
2867 | if (kill) | |
2868 | bitmap_ior_into (kill, group->group_kill); | |
2869 | bitmap_and_compl_into (gen, group->group_kill); | |
2870 | } | |
2871 | } | |
2872 | } | |
2873 | } | |
b8698a0f | 2874 | |
6fb5fa3c DB |
2875 | read_info = read_info->next; |
2876 | } | |
2877 | } | |
2878 | ||
6fb5fa3c DB |
2879 | |
2880 | /* Return the insn in BB_INFO before the first wild read or if there | |
2881 | are no wild reads in the block, return the last insn. */ | |
2882 | ||
2883 | static insn_info_t | |
2884 | find_insn_before_first_wild_read (bb_info_t bb_info) | |
2885 | { | |
2886 | insn_info_t insn_info = bb_info->last_insn; | |
2887 | insn_info_t last_wild_read = NULL; | |
2888 | ||
2889 | while (insn_info) | |
2890 | { | |
2891 | if (insn_info->wild_read) | |
2892 | { | |
2893 | last_wild_read = insn_info->prev_insn; | |
2894 | /* Block starts with wild read. */ | |
2895 | if (!last_wild_read) | |
2896 | return NULL; | |
2897 | } | |
2898 | ||
2899 | insn_info = insn_info->prev_insn; | |
2900 | } | |
2901 | ||
2902 | if (last_wild_read) | |
2903 | return last_wild_read; | |
2904 | else | |
2905 | return bb_info->last_insn; | |
2906 | } | |
2907 | ||
2908 | ||
2909 | /* Scan the insns in BB_INFO starting at PTR and going to the top of | |
2910 | the block in order to build the gen and kill sets for the block. | |
2911 | We start at ptr which may be the last insn in the block or may be | |
2912 | the first insn with a wild read. In the latter case we are able to | |
2913 | skip the rest of the block because it just does not matter: | |
2914 | anything that happens is hidden by the wild read. */ | |
2915 | ||
2916 | static void | |
ac6929b5 | 2917 | dse_step3_scan (basic_block bb) |
6fb5fa3c DB |
2918 | { |
2919 | bb_info_t bb_info = bb_table[bb->index]; | |
2920 | insn_info_t insn_info; | |
2921 | ||
ac6929b5 | 2922 | insn_info = find_insn_before_first_wild_read (bb_info); |
b8698a0f | 2923 | |
6fb5fa3c DB |
2924 | /* In the spill case or in the no_spill case if there is no wild |
2925 | read in the block, we will need a kill set. */ | |
2926 | if (insn_info == bb_info->last_insn) | |
2927 | { | |
2928 | if (bb_info->kill) | |
2929 | bitmap_clear (bb_info->kill); | |
2930 | else | |
3f9b14ff | 2931 | bb_info->kill = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c | 2932 | } |
b8698a0f | 2933 | else |
6fb5fa3c DB |
2934 | if (bb_info->kill) |
2935 | BITMAP_FREE (bb_info->kill); | |
2936 | ||
2937 | while (insn_info) | |
2938 | { | |
2939 | /* There may have been code deleted by the dce pass run before | |
2940 | this phase. */ | |
2941 | if (insn_info->insn && INSN_P (insn_info->insn)) | |
2942 | { | |
ac6929b5 RB |
2943 | scan_stores (insn_info->store_rec, bb_info->gen, bb_info->kill); |
2944 | scan_reads (insn_info, bb_info->gen, bb_info->kill); | |
b8698a0f | 2945 | } |
6fb5fa3c DB |
2946 | |
2947 | insn_info = insn_info->prev_insn; | |
2948 | } | |
2949 | } | |
2950 | ||
2951 | ||
2952 | /* Set the gen set of the exit block, and also any block with no | |
2953 | successors that does not have a wild read. */ | |
2954 | ||
2955 | static void | |
2956 | dse_step3_exit_block_scan (bb_info_t bb_info) | |
2957 | { | |
2958 | /* The gen set is all 0's for the exit block except for the | |
2959 | frame_pointer_group. */ | |
b8698a0f | 2960 | |
6fb5fa3c DB |
2961 | if (stores_off_frame_dead_at_return) |
2962 | { | |
2963 | unsigned int i; | |
fd6daec9 | 2964 | group_info *group; |
b8698a0f | 2965 | |
9771b263 | 2966 | FOR_EACH_VEC_ELT (rtx_group_vec, i, group) |
6fb5fa3c DB |
2967 | { |
2968 | if (group->process_globally && group->frame_related) | |
2969 | bitmap_ior_into (bb_info->gen, group->group_kill); | |
2970 | } | |
2971 | } | |
2972 | } | |
2973 | ||
2974 | ||
2975 | /* Find all of the blocks that are not backwards reachable from the | |
2976 | exit block or any block with no successors (BB). These are the | |
2977 | infinite loops or infinite self loops. These blocks will still | |
2978 | have their bits set in UNREACHABLE_BLOCKS. */ | |
2979 | ||
2980 | static void | |
2981 | mark_reachable_blocks (sbitmap unreachable_blocks, basic_block bb) | |
2982 | { | |
2983 | edge e; | |
2984 | edge_iterator ei; | |
2985 | ||
d7c028c0 | 2986 | if (bitmap_bit_p (unreachable_blocks, bb->index)) |
6fb5fa3c | 2987 | { |
d7c028c0 | 2988 | bitmap_clear_bit (unreachable_blocks, bb->index); |
6fb5fa3c | 2989 | FOR_EACH_EDGE (e, ei, bb->preds) |
b8698a0f | 2990 | { |
6fb5fa3c | 2991 | mark_reachable_blocks (unreachable_blocks, e->src); |
b8698a0f | 2992 | } |
6fb5fa3c DB |
2993 | } |
2994 | } | |
2995 | ||
2996 | /* Build the transfer functions for the function. */ | |
2997 | ||
2998 | static void | |
ac6929b5 | 2999 | dse_step3 () |
6fb5fa3c DB |
3000 | { |
3001 | basic_block bb; | |
8b1c6fd7 | 3002 | sbitmap unreachable_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
6fb5fa3c DB |
3003 | sbitmap_iterator sbi; |
3004 | bitmap all_ones = NULL; | |
3005 | unsigned int i; | |
b8698a0f | 3006 | |
f61e445a | 3007 | bitmap_ones (unreachable_blocks); |
6fb5fa3c | 3008 | |
04a90bec | 3009 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
3010 | { |
3011 | bb_info_t bb_info = bb_table[bb->index]; | |
3012 | if (bb_info->gen) | |
3013 | bitmap_clear (bb_info->gen); | |
3014 | else | |
3f9b14ff | 3015 | bb_info->gen = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3016 | |
3017 | if (bb->index == ENTRY_BLOCK) | |
3018 | ; | |
3019 | else if (bb->index == EXIT_BLOCK) | |
3020 | dse_step3_exit_block_scan (bb_info); | |
3021 | else | |
ac6929b5 | 3022 | dse_step3_scan (bb); |
6fb5fa3c DB |
3023 | if (EDGE_COUNT (bb->succs) == 0) |
3024 | mark_reachable_blocks (unreachable_blocks, bb); | |
3025 | ||
3026 | /* If this is the second time dataflow is run, delete the old | |
3027 | sets. */ | |
3028 | if (bb_info->in) | |
3029 | BITMAP_FREE (bb_info->in); | |
3030 | if (bb_info->out) | |
3031 | BITMAP_FREE (bb_info->out); | |
3032 | } | |
3033 | ||
3034 | /* For any block in an infinite loop, we must initialize the out set | |
3035 | to all ones. This could be expensive, but almost never occurs in | |
3036 | practice. However, it is common in regression tests. */ | |
d4ac4ce2 | 3037 | EXECUTE_IF_SET_IN_BITMAP (unreachable_blocks, 0, i, sbi) |
6fb5fa3c DB |
3038 | { |
3039 | if (bitmap_bit_p (all_blocks, i)) | |
3040 | { | |
3041 | bb_info_t bb_info = bb_table[i]; | |
3042 | if (!all_ones) | |
3043 | { | |
3044 | unsigned int j; | |
fd6daec9 | 3045 | group_info *group; |
6fb5fa3c | 3046 | |
3f9b14ff | 3047 | all_ones = BITMAP_ALLOC (&dse_bitmap_obstack); |
9771b263 | 3048 | FOR_EACH_VEC_ELT (rtx_group_vec, j, group) |
6fb5fa3c DB |
3049 | bitmap_ior_into (all_ones, group->group_kill); |
3050 | } | |
3051 | if (!bb_info->out) | |
3052 | { | |
3f9b14ff | 3053 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3054 | bitmap_copy (bb_info->out, all_ones); |
3055 | } | |
3056 | } | |
3057 | } | |
3058 | ||
3059 | if (all_ones) | |
3060 | BITMAP_FREE (all_ones); | |
3061 | sbitmap_free (unreachable_blocks); | |
3062 | } | |
3063 | ||
3064 | ||
3065 | \f | |
3066 | /*---------------------------------------------------------------------------- | |
3067 | Fourth step. | |
3068 | ||
3069 | Solve the bitvector equations. | |
3070 | ----------------------------------------------------------------------------*/ | |
3071 | ||
3072 | ||
3073 | /* Confluence function for blocks with no successors. Create an out | |
3074 | set from the gen set of the exit block. This block logically has | |
3075 | the exit block as a successor. */ | |
3076 | ||
3077 | ||
3078 | ||
3079 | static void | |
3080 | dse_confluence_0 (basic_block bb) | |
3081 | { | |
3082 | bb_info_t bb_info = bb_table[bb->index]; | |
3083 | ||
3084 | if (bb->index == EXIT_BLOCK) | |
3085 | return; | |
3086 | ||
3087 | if (!bb_info->out) | |
3088 | { | |
3f9b14ff | 3089 | bb_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3090 | bitmap_copy (bb_info->out, bb_table[EXIT_BLOCK]->gen); |
3091 | } | |
3092 | } | |
3093 | ||
3094 | /* Propagate the information from the in set of the dest of E to the | |
3095 | out set of the src of E. If the various in or out sets are not | |
3096 | there, that means they are all ones. */ | |
3097 | ||
1a0f3fa1 | 3098 | static bool |
6fb5fa3c DB |
3099 | dse_confluence_n (edge e) |
3100 | { | |
3101 | bb_info_t src_info = bb_table[e->src->index]; | |
3102 | bb_info_t dest_info = bb_table[e->dest->index]; | |
3103 | ||
3104 | if (dest_info->in) | |
3105 | { | |
3106 | if (src_info->out) | |
3107 | bitmap_and_into (src_info->out, dest_info->in); | |
3108 | else | |
3109 | { | |
3f9b14ff | 3110 | src_info->out = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3111 | bitmap_copy (src_info->out, dest_info->in); |
3112 | } | |
3113 | } | |
1a0f3fa1 | 3114 | return true; |
6fb5fa3c DB |
3115 | } |
3116 | ||
3117 | ||
3118 | /* Propagate the info from the out to the in set of BB_INDEX's basic | |
b8698a0f | 3119 | block. There are three cases: |
6fb5fa3c DB |
3120 | |
3121 | 1) The block has no kill set. In this case the kill set is all | |
3122 | ones. It does not matter what the out set of the block is, none of | |
3123 | the info can reach the top. The only thing that reaches the top is | |
3124 | the gen set and we just copy the set. | |
3125 | ||
3126 | 2) There is a kill set but no out set and bb has successors. In | |
3127 | this case we just return. Eventually an out set will be created and | |
3128 | it is better to wait than to create a set of ones. | |
3129 | ||
3130 | 3) There is both a kill and out set. We apply the obvious transfer | |
3131 | function. | |
3132 | */ | |
3133 | ||
3134 | static bool | |
3135 | dse_transfer_function (int bb_index) | |
3136 | { | |
3137 | bb_info_t bb_info = bb_table[bb_index]; | |
3138 | ||
3139 | if (bb_info->kill) | |
3140 | { | |
3141 | if (bb_info->out) | |
3142 | { | |
3143 | /* Case 3 above. */ | |
3144 | if (bb_info->in) | |
b8698a0f | 3145 | return bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3146 | bb_info->out, bb_info->kill); |
3147 | else | |
3148 | { | |
3f9b14ff | 3149 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
b8698a0f | 3150 | bitmap_ior_and_compl (bb_info->in, bb_info->gen, |
6fb5fa3c DB |
3151 | bb_info->out, bb_info->kill); |
3152 | return true; | |
3153 | } | |
3154 | } | |
3155 | else | |
3156 | /* Case 2 above. */ | |
3157 | return false; | |
3158 | } | |
3159 | else | |
3160 | { | |
3161 | /* Case 1 above. If there is already an in set, nothing | |
3162 | happens. */ | |
3163 | if (bb_info->in) | |
3164 | return false; | |
3165 | else | |
3166 | { | |
3f9b14ff | 3167 | bb_info->in = BITMAP_ALLOC (&dse_bitmap_obstack); |
6fb5fa3c DB |
3168 | bitmap_copy (bb_info->in, bb_info->gen); |
3169 | return true; | |
3170 | } | |
3171 | } | |
3172 | } | |
3173 | ||
3174 | /* Solve the dataflow equations. */ | |
3175 | ||
3176 | static void | |
3177 | dse_step4 (void) | |
3178 | { | |
b8698a0f L |
3179 | df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0, |
3180 | dse_confluence_n, dse_transfer_function, | |
3181 | all_blocks, df_get_postorder (DF_BACKWARD), | |
6fb5fa3c | 3182 | df_get_n_blocks (DF_BACKWARD)); |
456610d3 | 3183 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3184 | { |
3185 | basic_block bb; | |
3186 | ||
3187 | fprintf (dump_file, "\n\n*** Global dataflow info after analysis.\n"); | |
04a90bec | 3188 | FOR_ALL_BB_FN (bb, cfun) |
6fb5fa3c DB |
3189 | { |
3190 | bb_info_t bb_info = bb_table[bb->index]; | |
3191 | ||
3192 | df_print_bb_index (bb, dump_file); | |
3193 | if (bb_info->in) | |
3194 | bitmap_print (dump_file, bb_info->in, " in: ", "\n"); | |
3195 | else | |
3196 | fprintf (dump_file, " in: *MISSING*\n"); | |
3197 | if (bb_info->gen) | |
3198 | bitmap_print (dump_file, bb_info->gen, " gen: ", "\n"); | |
3199 | else | |
3200 | fprintf (dump_file, " gen: *MISSING*\n"); | |
3201 | if (bb_info->kill) | |
3202 | bitmap_print (dump_file, bb_info->kill, " kill: ", "\n"); | |
3203 | else | |
3204 | fprintf (dump_file, " kill: *MISSING*\n"); | |
3205 | if (bb_info->out) | |
3206 | bitmap_print (dump_file, bb_info->out, " out: ", "\n"); | |
3207 | else | |
3208 | fprintf (dump_file, " out: *MISSING*\n\n"); | |
3209 | } | |
3210 | } | |
3211 | } | |
3212 | ||
3213 | ||
3214 | \f | |
3215 | /*---------------------------------------------------------------------------- | |
3216 | Fifth step. | |
3217 | ||
0d52bcc1 | 3218 | Delete the stores that can only be deleted using the global information. |
6fb5fa3c DB |
3219 | ----------------------------------------------------------------------------*/ |
3220 | ||
3221 | ||
3222 | static void | |
ac6929b5 | 3223 | dse_step5 (void) |
6fb5fa3c DB |
3224 | { |
3225 | basic_block bb; | |
11cd3bed | 3226 | FOR_EACH_BB_FN (bb, cfun) |
6fb5fa3c DB |
3227 | { |
3228 | bb_info_t bb_info = bb_table[bb->index]; | |
3229 | insn_info_t insn_info = bb_info->last_insn; | |
3230 | bitmap v = bb_info->out; | |
3231 | ||
3232 | while (insn_info) | |
3233 | { | |
3234 | bool deleted = false; | |
3235 | if (dump_file && insn_info->insn) | |
3236 | { | |
3237 | fprintf (dump_file, "starting to process insn %d\n", | |
3238 | INSN_UID (insn_info->insn)); | |
3239 | bitmap_print (dump_file, v, " v: ", "\n"); | |
3240 | } | |
3241 | ||
3242 | /* There may have been code deleted by the dce pass run before | |
3243 | this phase. */ | |
b8698a0f | 3244 | if (insn_info->insn |
6fb5fa3c DB |
3245 | && INSN_P (insn_info->insn) |
3246 | && (!insn_info->cannot_delete) | |
3247 | && (!bitmap_empty_p (v))) | |
3248 | { | |
fd6daec9 | 3249 | store_info *store_info = insn_info->store_rec; |
6fb5fa3c DB |
3250 | |
3251 | /* Try to delete the current insn. */ | |
3252 | deleted = true; | |
b8698a0f | 3253 | |
6fb5fa3c DB |
3254 | /* Skip the clobbers. */ |
3255 | while (!store_info->is_set) | |
3256 | store_info = store_info->next; | |
3257 | ||
ac6929b5 RB |
3258 | HOST_WIDE_INT i; |
3259 | group_info *group_info = rtx_group_vec[store_info->group_id]; | |
3260 | ||
3261 | for (i = store_info->begin; i < store_info->end; i++) | |
6fb5fa3c | 3262 | { |
ac6929b5 | 3263 | int index = get_bitmap_index (group_info, i); |
b8698a0f | 3264 | |
ac6929b5 RB |
3265 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3266 | fprintf (dump_file, "i = %d, index = %d\n", (int)i, index); | |
3267 | if (index == 0 || !bitmap_bit_p (v, index)) | |
6fb5fa3c | 3268 | { |
456610d3 | 3269 | if (dump_file && (dump_flags & TDF_DETAILS)) |
ac6929b5 RB |
3270 | fprintf (dump_file, "failing at i = %d\n", (int)i); |
3271 | deleted = false; | |
3272 | break; | |
6fb5fa3c DB |
3273 | } |
3274 | } | |
3275 | if (deleted) | |
3276 | { | |
9e582b1d JR |
3277 | if (dbg_cnt (dse) |
3278 | && check_for_inc_dec_1 (insn_info)) | |
6fb5fa3c | 3279 | { |
6fb5fa3c DB |
3280 | delete_insn (insn_info->insn); |
3281 | insn_info->insn = NULL; | |
3282 | globally_deleted++; | |
3283 | } | |
3284 | } | |
3285 | } | |
3286 | /* We do want to process the local info if the insn was | |
6ed3da00 | 3287 | deleted. For instance, if the insn did a wild read, we |
6fb5fa3c | 3288 | no longer need to trash the info. */ |
b8698a0f | 3289 | if (insn_info->insn |
6fb5fa3c DB |
3290 | && INSN_P (insn_info->insn) |
3291 | && (!deleted)) | |
3292 | { | |
ac6929b5 | 3293 | scan_stores (insn_info->store_rec, v, NULL); |
6fb5fa3c DB |
3294 | if (insn_info->wild_read) |
3295 | { | |
456610d3 | 3296 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c DB |
3297 | fprintf (dump_file, "wild read\n"); |
3298 | bitmap_clear (v); | |
3299 | } | |
d26c7090 ER |
3300 | else if (insn_info->read_rec |
3301 | || insn_info->non_frame_wild_read) | |
6fb5fa3c | 3302 | { |
d26c7090 | 3303 | if (dump_file && !insn_info->non_frame_wild_read) |
6fb5fa3c | 3304 | fprintf (dump_file, "regular read\n"); |
456610d3 | 3305 | else if (dump_file && (dump_flags & TDF_DETAILS)) |
d26c7090 | 3306 | fprintf (dump_file, "non-frame wild read\n"); |
ac6929b5 | 3307 | scan_reads (insn_info, v, NULL); |
6fb5fa3c DB |
3308 | } |
3309 | } | |
b8698a0f | 3310 | |
6fb5fa3c DB |
3311 | insn_info = insn_info->prev_insn; |
3312 | } | |
3313 | } | |
3314 | } | |
3315 | ||
3316 | ||
6fb5fa3c DB |
3317 | \f |
3318 | /*---------------------------------------------------------------------------- | |
3319 | Sixth step. | |
3320 | ||
8dd5516b JJ |
3321 | Delete stores made redundant by earlier stores (which store the same |
3322 | value) that couldn't be eliminated. | |
3323 | ----------------------------------------------------------------------------*/ | |
3324 | ||
3325 | static void | |
3326 | dse_step6 (void) | |
3327 | { | |
3328 | basic_block bb; | |
3329 | ||
04a90bec | 3330 | FOR_ALL_BB_FN (bb, cfun) |
8dd5516b JJ |
3331 | { |
3332 | bb_info_t bb_info = bb_table[bb->index]; | |
3333 | insn_info_t insn_info = bb_info->last_insn; | |
3334 | ||
3335 | while (insn_info) | |
3336 | { | |
3337 | /* There may have been code deleted by the dce pass run before | |
3338 | this phase. */ | |
3339 | if (insn_info->insn | |
3340 | && INSN_P (insn_info->insn) | |
3341 | && !insn_info->cannot_delete) | |
3342 | { | |
fd6daec9 | 3343 | store_info *s_info = insn_info->store_rec; |
8dd5516b JJ |
3344 | |
3345 | while (s_info && !s_info->is_set) | |
3346 | s_info = s_info->next; | |
3347 | if (s_info | |
3348 | && s_info->redundant_reason | |
3349 | && s_info->redundant_reason->insn | |
3350 | && INSN_P (s_info->redundant_reason->insn)) | |
3351 | { | |
eb92d49a | 3352 | rtx_insn *rinsn = s_info->redundant_reason->insn; |
456610d3 | 3353 | if (dump_file && (dump_flags & TDF_DETAILS)) |
8dd5516b JJ |
3354 | fprintf (dump_file, "Locally deleting insn %d " |
3355 | "because insn %d stores the " | |
3356 | "same value and couldn't be " | |
3357 | "eliminated\n", | |
3358 | INSN_UID (insn_info->insn), | |
3359 | INSN_UID (rinsn)); | |
3360 | delete_dead_store_insn (insn_info); | |
3361 | } | |
3362 | } | |
3363 | insn_info = insn_info->prev_insn; | |
3364 | } | |
3365 | } | |
3366 | } | |
3367 | \f | |
3368 | /*---------------------------------------------------------------------------- | |
3369 | Seventh step. | |
3370 | ||
b8698a0f | 3371 | Destroy everything left standing. |
6fb5fa3c DB |
3372 | ----------------------------------------------------------------------------*/ |
3373 | ||
b8698a0f | 3374 | static void |
3f9b14ff | 3375 | dse_step7 (void) |
6fb5fa3c | 3376 | { |
3f9b14ff SB |
3377 | bitmap_obstack_release (&dse_bitmap_obstack); |
3378 | obstack_free (&dse_obstack, NULL); | |
370f38e8 | 3379 | |
6fb5fa3c DB |
3380 | end_alias_analysis (); |
3381 | free (bb_table); | |
c203e8a7 TS |
3382 | delete rtx_group_table; |
3383 | rtx_group_table = NULL; | |
9771b263 | 3384 | rtx_group_vec.release (); |
6fb5fa3c DB |
3385 | BITMAP_FREE (all_blocks); |
3386 | BITMAP_FREE (scratch); | |
3387 | ||
da6603c6 | 3388 | rtx_store_info_pool.release (); |
fb0b2914 ML |
3389 | read_info_type_pool.release (); |
3390 | insn_info_type_pool.release (); | |
3391 | dse_bb_info_type_pool.release (); | |
3392 | group_info_pool.release (); | |
3393 | deferred_change_pool.release (); | |
6fb5fa3c DB |
3394 | } |
3395 | ||
3396 | ||
6fb5fa3c DB |
3397 | /* ------------------------------------------------------------------------- |
3398 | DSE | |
3399 | ------------------------------------------------------------------------- */ | |
3400 | ||
3401 | /* Callback for running pass_rtl_dse. */ | |
3402 | ||
3403 | static unsigned int | |
3404 | rest_of_handle_dse (void) | |
3405 | { | |
6fb5fa3c DB |
3406 | df_set_flags (DF_DEFER_INSN_RESCAN); |
3407 | ||
02b47899 KZ |
3408 | /* Need the notes since we must track live hardregs in the forwards |
3409 | direction. */ | |
3410 | df_note_add_problem (); | |
3411 | df_analyze (); | |
3412 | ||
6fb5fa3c DB |
3413 | dse_step0 (); |
3414 | dse_step1 (); | |
3415 | dse_step2_init (); | |
ac6929b5 | 3416 | if (dse_step2 ()) |
6fb5fa3c DB |
3417 | { |
3418 | df_set_flags (DF_LR_RUN_DCE); | |
3419 | df_analyze (); | |
456610d3 | 3420 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6fb5fa3c | 3421 | fprintf (dump_file, "doing global processing\n"); |
ac6929b5 | 3422 | dse_step3 (); |
6fb5fa3c | 3423 | dse_step4 (); |
ac6929b5 | 3424 | dse_step5 (); |
6fb5fa3c DB |
3425 | } |
3426 | ||
8dd5516b | 3427 | dse_step6 (); |
3f9b14ff | 3428 | dse_step7 (); |
6fb5fa3c DB |
3429 | |
3430 | if (dump_file) | |
ac6929b5 RB |
3431 | fprintf (dump_file, "dse: local deletions = %d, global deletions = %d\n", |
3432 | locally_deleted, globally_deleted); | |
6c5ed3f1 JJ |
3433 | |
3434 | /* DSE can eliminate potentially-trapping MEMs. | |
3435 | Remove any EH edges associated with them. */ | |
3436 | if ((locally_deleted || globally_deleted) | |
3437 | && cfun->can_throw_non_call_exceptions | |
3438 | && purge_all_dead_edges ()) | |
3439 | cleanup_cfg (0); | |
3440 | ||
6fb5fa3c DB |
3441 | return 0; |
3442 | } | |
3443 | ||
17795822 TS |
3444 | namespace { |
3445 | ||
3446 | const pass_data pass_data_rtl_dse1 = | |
27a4cd48 DM |
3447 | { |
3448 | RTL_PASS, /* type */ | |
3449 | "dse1", /* name */ | |
3450 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3451 | TV_DSE1, /* tv_id */ |
3452 | 0, /* properties_required */ | |
3453 | 0, /* properties_provided */ | |
3454 | 0, /* properties_destroyed */ | |
3455 | 0, /* todo_flags_start */ | |
3bea341f | 3456 | TODO_df_finish, /* todo_flags_finish */ |
6fb5fa3c DB |
3457 | }; |
3458 | ||
17795822 | 3459 | class pass_rtl_dse1 : public rtl_opt_pass |
27a4cd48 DM |
3460 | { |
3461 | public: | |
c3284718 RS |
3462 | pass_rtl_dse1 (gcc::context *ctxt) |
3463 | : rtl_opt_pass (pass_data_rtl_dse1, ctxt) | |
27a4cd48 DM |
3464 | {} |
3465 | ||
3466 | /* opt_pass methods: */ | |
1a3d085c TS |
3467 | virtual bool gate (function *) |
3468 | { | |
3469 | return optimize > 0 && flag_dse && dbg_cnt (dse1); | |
3470 | } | |
3471 | ||
be55bfe6 | 3472 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
27a4cd48 DM |
3473 | |
3474 | }; // class pass_rtl_dse1 | |
3475 | ||
17795822 TS |
3476 | } // anon namespace |
3477 | ||
27a4cd48 DM |
3478 | rtl_opt_pass * |
3479 | make_pass_rtl_dse1 (gcc::context *ctxt) | |
3480 | { | |
3481 | return new pass_rtl_dse1 (ctxt); | |
3482 | } | |
3483 | ||
17795822 TS |
3484 | namespace { |
3485 | ||
3486 | const pass_data pass_data_rtl_dse2 = | |
27a4cd48 DM |
3487 | { |
3488 | RTL_PASS, /* type */ | |
3489 | "dse2", /* name */ | |
3490 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3491 | TV_DSE2, /* tv_id */ |
3492 | 0, /* properties_required */ | |
3493 | 0, /* properties_provided */ | |
3494 | 0, /* properties_destroyed */ | |
3495 | 0, /* todo_flags_start */ | |
3bea341f | 3496 | TODO_df_finish, /* todo_flags_finish */ |
6fb5fa3c | 3497 | }; |
27a4cd48 | 3498 | |
17795822 | 3499 | class pass_rtl_dse2 : public rtl_opt_pass |
27a4cd48 DM |
3500 | { |
3501 | public: | |
c3284718 RS |
3502 | pass_rtl_dse2 (gcc::context *ctxt) |
3503 | : rtl_opt_pass (pass_data_rtl_dse2, ctxt) | |
27a4cd48 DM |
3504 | {} |
3505 | ||
3506 | /* opt_pass methods: */ | |
1a3d085c TS |
3507 | virtual bool gate (function *) |
3508 | { | |
3509 | return optimize > 0 && flag_dse && dbg_cnt (dse2); | |
3510 | } | |
3511 | ||
be55bfe6 | 3512 | virtual unsigned int execute (function *) { return rest_of_handle_dse (); } |
27a4cd48 DM |
3513 | |
3514 | }; // class pass_rtl_dse2 | |
3515 | ||
17795822 TS |
3516 | } // anon namespace |
3517 | ||
27a4cd48 DM |
3518 | rtl_opt_pass * |
3519 | make_pass_rtl_dse2 (gcc::context *ctxt) | |
3520 | { | |
3521 | return new pass_rtl_dse2 (ctxt); | |
3522 | } |