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dda118e3 JM |
1 | /* Reassociation for trees. |
2 | Copyright (C) 2005-2015 Free Software Foundation, Inc. | |
3 | Contributed by Daniel Berlin <dan@dberlin.org> | |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "hash-table.h" | |
25 | #include "tm.h" | |
26 | #include "rtl.h" | |
27 | #include "tm_p.h" | |
28 | #include "hash-set.h" | |
29 | #include "machmode.h" | |
30 | #include "vec.h" | |
31 | #include "double-int.h" | |
32 | #include "input.h" | |
33 | #include "alias.h" | |
34 | #include "symtab.h" | |
35 | #include "wide-int.h" | |
36 | #include "inchash.h" | |
37 | #include "tree.h" | |
38 | #include "fold-const.h" | |
39 | #include "stor-layout.h" | |
40 | #include "predict.h" | |
41 | #include "hard-reg-set.h" | |
42 | #include "function.h" | |
43 | #include "dominance.h" | |
44 | #include "cfg.h" | |
45 | #include "cfganal.h" | |
46 | #include "basic-block.h" | |
47 | #include "gimple-pretty-print.h" | |
48 | #include "tree-inline.h" | |
49 | #include "hash-map.h" | |
50 | #include "tree-ssa-alias.h" | |
51 | #include "internal-fn.h" | |
52 | #include "gimple-fold.h" | |
53 | #include "tree-eh.h" | |
54 | #include "gimple-expr.h" | |
55 | #include "is-a.h" | |
56 | #include "gimple.h" | |
57 | #include "gimple-iterator.h" | |
58 | #include "gimplify-me.h" | |
59 | #include "gimple-ssa.h" | |
60 | #include "tree-cfg.h" | |
61 | #include "tree-phinodes.h" | |
62 | #include "ssa-iterators.h" | |
63 | #include "stringpool.h" | |
64 | #include "tree-ssanames.h" | |
65 | #include "tree-ssa-loop-niter.h" | |
66 | #include "tree-ssa-loop.h" | |
67 | #include "hashtab.h" | |
68 | #include "flags.h" | |
69 | #include "statistics.h" | |
70 | #include "real.h" | |
71 | #include "fixed-value.h" | |
72 | #include "insn-config.h" | |
73 | #include "expmed.h" | |
74 | #include "dojump.h" | |
75 | #include "explow.h" | |
76 | #include "calls.h" | |
77 | #include "emit-rtl.h" | |
78 | #include "varasm.h" | |
79 | #include "stmt.h" | |
80 | #include "expr.h" | |
81 | #include "tree-dfa.h" | |
82 | #include "tree-ssa.h" | |
83 | #include "tree-iterator.h" | |
84 | #include "tree-pass.h" | |
85 | #include "alloc-pool.h" | |
86 | #include "langhooks.h" | |
87 | #include "cfgloop.h" | |
88 | #include "target.h" | |
89 | #include "params.h" | |
90 | #include "diagnostic-core.h" | |
91 | #include "builtins.h" | |
92 | #include "gimplify.h" | |
93 | #include "insn-codes.h" | |
94 | #include "optabs.h" | |
95 | ||
96 | /* This is a simple global reassociation pass. It is, in part, based | |
97 | on the LLVM pass of the same name (They do some things more/less | |
98 | than we do, in different orders, etc). | |
99 | ||
100 | It consists of five steps: | |
101 | ||
102 | 1. Breaking up subtract operations into addition + negate, where | |
103 | it would promote the reassociation of adds. | |
104 | ||
105 | 2. Left linearization of the expression trees, so that (A+B)+(C+D) | |
106 | becomes (((A+B)+C)+D), which is easier for us to rewrite later. | |
107 | During linearization, we place the operands of the binary | |
108 | expressions into a vector of operand_entry_t | |
109 | ||
110 | 3. Optimization of the operand lists, eliminating things like a + | |
111 | -a, a & a, etc. | |
112 | ||
113 | 3a. Combine repeated factors with the same occurrence counts | |
114 | into a __builtin_powi call that will later be optimized into | |
115 | an optimal number of multiplies. | |
116 | ||
117 | 4. Rewrite the expression trees we linearized and optimized so | |
118 | they are in proper rank order. | |
119 | ||
120 | 5. Repropagate negates, as nothing else will clean it up ATM. | |
121 | ||
122 | A bit of theory on #4, since nobody seems to write anything down | |
123 | about why it makes sense to do it the way they do it: | |
124 | ||
125 | We could do this much nicer theoretically, but don't (for reasons | |
126 | explained after how to do it theoretically nice :P). | |
127 | ||
128 | In order to promote the most redundancy elimination, you want | |
129 | binary expressions whose operands are the same rank (or | |
130 | preferably, the same value) exposed to the redundancy eliminator, | |
131 | for possible elimination. | |
132 | ||
133 | So the way to do this if we really cared, is to build the new op | |
134 | tree from the leaves to the roots, merging as you go, and putting the | |
135 | new op on the end of the worklist, until you are left with one | |
136 | thing on the worklist. | |
137 | ||
138 | IE if you have to rewrite the following set of operands (listed with | |
139 | rank in parentheses), with opcode PLUS_EXPR: | |
140 | ||
141 | a (1), b (1), c (1), d (2), e (2) | |
142 | ||
143 | ||
144 | We start with our merge worklist empty, and the ops list with all of | |
145 | those on it. | |
146 | ||
147 | You want to first merge all leaves of the same rank, as much as | |
148 | possible. | |
149 | ||
150 | So first build a binary op of | |
151 | ||
152 | mergetmp = a + b, and put "mergetmp" on the merge worklist. | |
153 | ||
154 | Because there is no three operand form of PLUS_EXPR, c is not going to | |
155 | be exposed to redundancy elimination as a rank 1 operand. | |
156 | ||
157 | So you might as well throw it on the merge worklist (you could also | |
158 | consider it to now be a rank two operand, and merge it with d and e, | |
159 | but in this case, you then have evicted e from a binary op. So at | |
160 | least in this situation, you can't win.) | |
161 | ||
162 | Then build a binary op of d + e | |
163 | mergetmp2 = d + e | |
164 | ||
165 | and put mergetmp2 on the merge worklist. | |
166 | ||
167 | so merge worklist = {mergetmp, c, mergetmp2} | |
168 | ||
169 | Continue building binary ops of these operations until you have only | |
170 | one operation left on the worklist. | |
171 | ||
172 | So we have | |
173 | ||
174 | build binary op | |
175 | mergetmp3 = mergetmp + c | |
176 | ||
177 | worklist = {mergetmp2, mergetmp3} | |
178 | ||
179 | mergetmp4 = mergetmp2 + mergetmp3 | |
180 | ||
181 | worklist = {mergetmp4} | |
182 | ||
183 | because we have one operation left, we can now just set the original | |
184 | statement equal to the result of that operation. | |
185 | ||
186 | This will at least expose a + b and d + e to redundancy elimination | |
187 | as binary operations. | |
188 | ||
189 | For extra points, you can reuse the old statements to build the | |
190 | mergetmps, since you shouldn't run out. | |
191 | ||
192 | So why don't we do this? | |
193 | ||
194 | Because it's expensive, and rarely will help. Most trees we are | |
195 | reassociating have 3 or less ops. If they have 2 ops, they already | |
196 | will be written into a nice single binary op. If you have 3 ops, a | |
197 | single simple check suffices to tell you whether the first two are of the | |
198 | same rank. If so, you know to order it | |
199 | ||
200 | mergetmp = op1 + op2 | |
201 | newstmt = mergetmp + op3 | |
202 | ||
203 | instead of | |
204 | mergetmp = op2 + op3 | |
205 | newstmt = mergetmp + op1 | |
206 | ||
207 | If all three are of the same rank, you can't expose them all in a | |
208 | single binary operator anyway, so the above is *still* the best you | |
209 | can do. | |
210 | ||
211 | Thus, this is what we do. When we have three ops left, we check to see | |
212 | what order to put them in, and call it a day. As a nod to vector sum | |
213 | reduction, we check if any of the ops are really a phi node that is a | |
214 | destructive update for the associating op, and keep the destructive | |
215 | update together for vector sum reduction recognition. */ | |
216 | ||
217 | ||
218 | /* Statistics */ | |
219 | static struct | |
220 | { | |
221 | int linearized; | |
222 | int constants_eliminated; | |
223 | int ops_eliminated; | |
224 | int rewritten; | |
225 | int pows_encountered; | |
226 | int pows_created; | |
227 | } reassociate_stats; | |
228 | ||
229 | /* Operator, rank pair. */ | |
230 | typedef struct operand_entry | |
231 | { | |
232 | unsigned int rank; | |
233 | int id; | |
234 | tree op; | |
235 | unsigned int count; | |
236 | } *operand_entry_t; | |
237 | ||
238 | static alloc_pool operand_entry_pool; | |
239 | ||
240 | /* This is used to assign a unique ID to each struct operand_entry | |
241 | so that qsort results are identical on different hosts. */ | |
242 | static int next_operand_entry_id; | |
243 | ||
244 | /* Starting rank number for a given basic block, so that we can rank | |
245 | operations using unmovable instructions in that BB based on the bb | |
246 | depth. */ | |
247 | static long *bb_rank; | |
248 | ||
249 | /* Operand->rank hashtable. */ | |
250 | static hash_map<tree, long> *operand_rank; | |
251 | ||
252 | /* Vector of SSA_NAMEs on which after reassociate_bb is done with | |
253 | all basic blocks the CFG should be adjusted - basic blocks | |
254 | split right after that SSA_NAME's definition statement and before | |
255 | the only use, which must be a bit ior. */ | |
256 | static vec<tree> reassoc_branch_fixups; | |
257 | ||
258 | /* Forward decls. */ | |
259 | static long get_rank (tree); | |
260 | static bool reassoc_stmt_dominates_stmt_p (gimple, gimple); | |
261 | ||
262 | /* Wrapper around gsi_remove, which adjusts gimple_uid of debug stmts | |
263 | possibly added by gsi_remove. */ | |
264 | ||
265 | bool | |
266 | reassoc_remove_stmt (gimple_stmt_iterator *gsi) | |
267 | { | |
268 | gimple stmt = gsi_stmt (*gsi); | |
269 | ||
270 | if (!MAY_HAVE_DEBUG_STMTS || gimple_code (stmt) == GIMPLE_PHI) | |
271 | return gsi_remove (gsi, true); | |
272 | ||
273 | gimple_stmt_iterator prev = *gsi; | |
274 | gsi_prev (&prev); | |
275 | unsigned uid = gimple_uid (stmt); | |
276 | basic_block bb = gimple_bb (stmt); | |
277 | bool ret = gsi_remove (gsi, true); | |
278 | if (!gsi_end_p (prev)) | |
279 | gsi_next (&prev); | |
280 | else | |
281 | prev = gsi_start_bb (bb); | |
282 | gimple end_stmt = gsi_stmt (*gsi); | |
283 | while ((stmt = gsi_stmt (prev)) != end_stmt) | |
284 | { | |
285 | gcc_assert (stmt && is_gimple_debug (stmt) && gimple_uid (stmt) == 0); | |
286 | gimple_set_uid (stmt, uid); | |
287 | gsi_next (&prev); | |
288 | } | |
289 | return ret; | |
290 | } | |
291 | ||
292 | /* Bias amount for loop-carried phis. We want this to be larger than | |
293 | the depth of any reassociation tree we can see, but not larger than | |
294 | the rank difference between two blocks. */ | |
295 | #define PHI_LOOP_BIAS (1 << 15) | |
296 | ||
297 | /* Rank assigned to a phi statement. If STMT is a loop-carried phi of | |
298 | an innermost loop, and the phi has only a single use which is inside | |
299 | the loop, then the rank is the block rank of the loop latch plus an | |
300 | extra bias for the loop-carried dependence. This causes expressions | |
301 | calculated into an accumulator variable to be independent for each | |
302 | iteration of the loop. If STMT is some other phi, the rank is the | |
303 | block rank of its containing block. */ | |
304 | static long | |
305 | phi_rank (gimple stmt) | |
306 | { | |
307 | basic_block bb = gimple_bb (stmt); | |
308 | struct loop *father = bb->loop_father; | |
309 | tree res; | |
310 | unsigned i; | |
311 | use_operand_p use; | |
312 | gimple use_stmt; | |
313 | ||
314 | /* We only care about real loops (those with a latch). */ | |
315 | if (!father->latch) | |
316 | return bb_rank[bb->index]; | |
317 | ||
318 | /* Interesting phis must be in headers of innermost loops. */ | |
319 | if (bb != father->header | |
320 | || father->inner) | |
321 | return bb_rank[bb->index]; | |
322 | ||
323 | /* Ignore virtual SSA_NAMEs. */ | |
324 | res = gimple_phi_result (stmt); | |
325 | if (virtual_operand_p (res)) | |
326 | return bb_rank[bb->index]; | |
327 | ||
328 | /* The phi definition must have a single use, and that use must be | |
329 | within the loop. Otherwise this isn't an accumulator pattern. */ | |
330 | if (!single_imm_use (res, &use, &use_stmt) | |
331 | || gimple_bb (use_stmt)->loop_father != father) | |
332 | return bb_rank[bb->index]; | |
333 | ||
334 | /* Look for phi arguments from within the loop. If found, bias this phi. */ | |
335 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
336 | { | |
337 | tree arg = gimple_phi_arg_def (stmt, i); | |
338 | if (TREE_CODE (arg) == SSA_NAME | |
339 | && !SSA_NAME_IS_DEFAULT_DEF (arg)) | |
340 | { | |
341 | gimple def_stmt = SSA_NAME_DEF_STMT (arg); | |
342 | if (gimple_bb (def_stmt)->loop_father == father) | |
343 | return bb_rank[father->latch->index] + PHI_LOOP_BIAS; | |
344 | } | |
345 | } | |
346 | ||
347 | /* Must be an uninteresting phi. */ | |
348 | return bb_rank[bb->index]; | |
349 | } | |
350 | ||
351 | /* If EXP is an SSA_NAME defined by a PHI statement that represents a | |
352 | loop-carried dependence of an innermost loop, return TRUE; else | |
353 | return FALSE. */ | |
354 | static bool | |
355 | loop_carried_phi (tree exp) | |
356 | { | |
357 | gimple phi_stmt; | |
358 | long block_rank; | |
359 | ||
360 | if (TREE_CODE (exp) != SSA_NAME | |
361 | || SSA_NAME_IS_DEFAULT_DEF (exp)) | |
362 | return false; | |
363 | ||
364 | phi_stmt = SSA_NAME_DEF_STMT (exp); | |
365 | ||
366 | if (gimple_code (SSA_NAME_DEF_STMT (exp)) != GIMPLE_PHI) | |
367 | return false; | |
368 | ||
369 | /* Non-loop-carried phis have block rank. Loop-carried phis have | |
370 | an additional bias added in. If this phi doesn't have block rank, | |
371 | it's biased and should not be propagated. */ | |
372 | block_rank = bb_rank[gimple_bb (phi_stmt)->index]; | |
373 | ||
374 | if (phi_rank (phi_stmt) != block_rank) | |
375 | return true; | |
376 | ||
377 | return false; | |
378 | } | |
379 | ||
380 | /* Return the maximum of RANK and the rank that should be propagated | |
381 | from expression OP. For most operands, this is just the rank of OP. | |
382 | For loop-carried phis, the value is zero to avoid undoing the bias | |
383 | in favor of the phi. */ | |
384 | static long | |
385 | propagate_rank (long rank, tree op) | |
386 | { | |
387 | long op_rank; | |
388 | ||
389 | if (loop_carried_phi (op)) | |
390 | return rank; | |
391 | ||
392 | op_rank = get_rank (op); | |
393 | ||
394 | return MAX (rank, op_rank); | |
395 | } | |
396 | ||
397 | /* Look up the operand rank structure for expression E. */ | |
398 | ||
399 | static inline long | |
400 | find_operand_rank (tree e) | |
401 | { | |
402 | long *slot = operand_rank->get (e); | |
403 | return slot ? *slot : -1; | |
404 | } | |
405 | ||
406 | /* Insert {E,RANK} into the operand rank hashtable. */ | |
407 | ||
408 | static inline void | |
409 | insert_operand_rank (tree e, long rank) | |
410 | { | |
411 | gcc_assert (rank > 0); | |
412 | gcc_assert (!operand_rank->put (e, rank)); | |
413 | } | |
414 | ||
415 | /* Given an expression E, return the rank of the expression. */ | |
416 | ||
417 | static long | |
418 | get_rank (tree e) | |
419 | { | |
420 | /* Constants have rank 0. */ | |
421 | if (is_gimple_min_invariant (e)) | |
422 | return 0; | |
423 | ||
424 | /* SSA_NAME's have the rank of the expression they are the result | |
425 | of. | |
426 | For globals and uninitialized values, the rank is 0. | |
427 | For function arguments, use the pre-setup rank. | |
428 | For PHI nodes, stores, asm statements, etc, we use the rank of | |
429 | the BB. | |
430 | For simple operations, the rank is the maximum rank of any of | |
431 | its operands, or the bb_rank, whichever is less. | |
432 | I make no claims that this is optimal, however, it gives good | |
433 | results. */ | |
434 | ||
435 | /* We make an exception to the normal ranking system to break | |
436 | dependences of accumulator variables in loops. Suppose we | |
437 | have a simple one-block loop containing: | |
438 | ||
439 | x_1 = phi(x_0, x_2) | |
440 | b = a + x_1 | |
441 | c = b + d | |
442 | x_2 = c + e | |
443 | ||
444 | As shown, each iteration of the calculation into x is fully | |
445 | dependent upon the iteration before it. We would prefer to | |
446 | see this in the form: | |
447 | ||
448 | x_1 = phi(x_0, x_2) | |
449 | b = a + d | |
450 | c = b + e | |
451 | x_2 = c + x_1 | |
452 | ||
453 | If the loop is unrolled, the calculations of b and c from | |
454 | different iterations can be interleaved. | |
455 | ||
456 | To obtain this result during reassociation, we bias the rank | |
457 | of the phi definition x_1 upward, when it is recognized as an | |
458 | accumulator pattern. The artificial rank causes it to be | |
459 | added last, providing the desired independence. */ | |
460 | ||
461 | if (TREE_CODE (e) == SSA_NAME) | |
462 | { | |
463 | gimple stmt; | |
464 | long rank; | |
465 | int i, n; | |
466 | tree op; | |
467 | ||
468 | if (SSA_NAME_IS_DEFAULT_DEF (e)) | |
469 | return find_operand_rank (e); | |
470 | ||
471 | stmt = SSA_NAME_DEF_STMT (e); | |
472 | if (gimple_code (stmt) == GIMPLE_PHI) | |
473 | return phi_rank (stmt); | |
474 | ||
475 | if (!is_gimple_assign (stmt) | |
476 | || gimple_vdef (stmt)) | |
477 | return bb_rank[gimple_bb (stmt)->index]; | |
478 | ||
479 | /* If we already have a rank for this expression, use that. */ | |
480 | rank = find_operand_rank (e); | |
481 | if (rank != -1) | |
482 | return rank; | |
483 | ||
484 | /* Otherwise, find the maximum rank for the operands. As an | |
485 | exception, remove the bias from loop-carried phis when propagating | |
486 | the rank so that dependent operations are not also biased. */ | |
487 | rank = 0; | |
488 | if (gimple_assign_single_p (stmt)) | |
489 | { | |
490 | tree rhs = gimple_assign_rhs1 (stmt); | |
491 | n = TREE_OPERAND_LENGTH (rhs); | |
492 | if (n == 0) | |
493 | rank = propagate_rank (rank, rhs); | |
494 | else | |
495 | { | |
496 | for (i = 0; i < n; i++) | |
497 | { | |
498 | op = TREE_OPERAND (rhs, i); | |
499 | ||
500 | if (op != NULL_TREE) | |
501 | rank = propagate_rank (rank, op); | |
502 | } | |
503 | } | |
504 | } | |
505 | else | |
506 | { | |
507 | n = gimple_num_ops (stmt); | |
508 | for (i = 1; i < n; i++) | |
509 | { | |
510 | op = gimple_op (stmt, i); | |
511 | gcc_assert (op); | |
512 | rank = propagate_rank (rank, op); | |
513 | } | |
514 | } | |
515 | ||
516 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
517 | { | |
518 | fprintf (dump_file, "Rank for "); | |
519 | print_generic_expr (dump_file, e, 0); | |
520 | fprintf (dump_file, " is %ld\n", (rank + 1)); | |
521 | } | |
522 | ||
523 | /* Note the rank in the hashtable so we don't recompute it. */ | |
524 | insert_operand_rank (e, (rank + 1)); | |
525 | return (rank + 1); | |
526 | } | |
527 | ||
528 | /* Globals, etc, are rank 0 */ | |
529 | return 0; | |
530 | } | |
531 | ||
532 | ||
533 | /* We want integer ones to end up last no matter what, since they are | |
534 | the ones we can do the most with. */ | |
535 | #define INTEGER_CONST_TYPE 1 << 3 | |
536 | #define FLOAT_CONST_TYPE 1 << 2 | |
537 | #define OTHER_CONST_TYPE 1 << 1 | |
538 | ||
539 | /* Classify an invariant tree into integer, float, or other, so that | |
540 | we can sort them to be near other constants of the same type. */ | |
541 | static inline int | |
542 | constant_type (tree t) | |
543 | { | |
544 | if (INTEGRAL_TYPE_P (TREE_TYPE (t))) | |
545 | return INTEGER_CONST_TYPE; | |
546 | else if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (t))) | |
547 | return FLOAT_CONST_TYPE; | |
548 | else | |
549 | return OTHER_CONST_TYPE; | |
550 | } | |
551 | ||
552 | /* qsort comparison function to sort operand entries PA and PB by rank | |
553 | so that the sorted array is ordered by rank in decreasing order. */ | |
554 | static int | |
555 | sort_by_operand_rank (const void *pa, const void *pb) | |
556 | { | |
557 | const operand_entry_t oea = *(const operand_entry_t *)pa; | |
558 | const operand_entry_t oeb = *(const operand_entry_t *)pb; | |
559 | ||
560 | /* It's nicer for optimize_expression if constants that are likely | |
561 | to fold when added/multiplied//whatever are put next to each | |
562 | other. Since all constants have rank 0, order them by type. */ | |
563 | if (oeb->rank == 0 && oea->rank == 0) | |
564 | { | |
565 | if (constant_type (oeb->op) != constant_type (oea->op)) | |
566 | return constant_type (oeb->op) - constant_type (oea->op); | |
567 | else | |
568 | /* To make sorting result stable, we use unique IDs to determine | |
569 | order. */ | |
570 | return oeb->id - oea->id; | |
571 | } | |
572 | ||
573 | /* Lastly, make sure the versions that are the same go next to each | |
574 | other. */ | |
575 | if ((oeb->rank - oea->rank == 0) | |
576 | && TREE_CODE (oea->op) == SSA_NAME | |
577 | && TREE_CODE (oeb->op) == SSA_NAME) | |
578 | { | |
579 | /* As SSA_NAME_VERSION is assigned pretty randomly, because we reuse | |
580 | versions of removed SSA_NAMEs, so if possible, prefer to sort | |
581 | based on basic block and gimple_uid of the SSA_NAME_DEF_STMT. | |
582 | See PR60418. */ | |
583 | if (!SSA_NAME_IS_DEFAULT_DEF (oea->op) | |
584 | && !SSA_NAME_IS_DEFAULT_DEF (oeb->op) | |
585 | && SSA_NAME_VERSION (oeb->op) != SSA_NAME_VERSION (oea->op)) | |
586 | { | |
587 | gimple stmta = SSA_NAME_DEF_STMT (oea->op); | |
588 | gimple stmtb = SSA_NAME_DEF_STMT (oeb->op); | |
589 | basic_block bba = gimple_bb (stmta); | |
590 | basic_block bbb = gimple_bb (stmtb); | |
591 | if (bbb != bba) | |
592 | { | |
593 | if (bb_rank[bbb->index] != bb_rank[bba->index]) | |
594 | return bb_rank[bbb->index] - bb_rank[bba->index]; | |
595 | } | |
596 | else | |
597 | { | |
598 | bool da = reassoc_stmt_dominates_stmt_p (stmta, stmtb); | |
599 | bool db = reassoc_stmt_dominates_stmt_p (stmtb, stmta); | |
600 | if (da != db) | |
601 | return da ? 1 : -1; | |
602 | } | |
603 | } | |
604 | ||
605 | if (SSA_NAME_VERSION (oeb->op) != SSA_NAME_VERSION (oea->op)) | |
606 | return SSA_NAME_VERSION (oeb->op) - SSA_NAME_VERSION (oea->op); | |
607 | else | |
608 | return oeb->id - oea->id; | |
609 | } | |
610 | ||
611 | if (oeb->rank != oea->rank) | |
612 | return oeb->rank - oea->rank; | |
613 | else | |
614 | return oeb->id - oea->id; | |
615 | } | |
616 | ||
617 | /* Add an operand entry to *OPS for the tree operand OP. */ | |
618 | ||
619 | static void | |
620 | add_to_ops_vec (vec<operand_entry_t> *ops, tree op) | |
621 | { | |
622 | operand_entry_t oe = (operand_entry_t) pool_alloc (operand_entry_pool); | |
623 | ||
624 | oe->op = op; | |
625 | oe->rank = get_rank (op); | |
626 | oe->id = next_operand_entry_id++; | |
627 | oe->count = 1; | |
628 | ops->safe_push (oe); | |
629 | } | |
630 | ||
631 | /* Add an operand entry to *OPS for the tree operand OP with repeat | |
632 | count REPEAT. */ | |
633 | ||
634 | static void | |
635 | add_repeat_to_ops_vec (vec<operand_entry_t> *ops, tree op, | |
636 | HOST_WIDE_INT repeat) | |
637 | { | |
638 | operand_entry_t oe = (operand_entry_t) pool_alloc (operand_entry_pool); | |
639 | ||
640 | oe->op = op; | |
641 | oe->rank = get_rank (op); | |
642 | oe->id = next_operand_entry_id++; | |
643 | oe->count = repeat; | |
644 | ops->safe_push (oe); | |
645 | ||
646 | reassociate_stats.pows_encountered++; | |
647 | } | |
648 | ||
649 | /* Return true if STMT is reassociable operation containing a binary | |
650 | operation with tree code CODE, and is inside LOOP. */ | |
651 | ||
652 | static bool | |
653 | is_reassociable_op (gimple stmt, enum tree_code code, struct loop *loop) | |
654 | { | |
655 | basic_block bb = gimple_bb (stmt); | |
656 | ||
657 | if (gimple_bb (stmt) == NULL) | |
658 | return false; | |
659 | ||
660 | if (!flow_bb_inside_loop_p (loop, bb)) | |
661 | return false; | |
662 | ||
663 | if (is_gimple_assign (stmt) | |
664 | && gimple_assign_rhs_code (stmt) == code | |
665 | && has_single_use (gimple_assign_lhs (stmt))) | |
666 | return true; | |
667 | ||
668 | return false; | |
669 | } | |
670 | ||
671 | ||
672 | /* Given NAME, if NAME is defined by a unary operation OPCODE, return the | |
673 | operand of the negate operation. Otherwise, return NULL. */ | |
674 | ||
675 | static tree | |
676 | get_unary_op (tree name, enum tree_code opcode) | |
677 | { | |
678 | gimple stmt = SSA_NAME_DEF_STMT (name); | |
679 | ||
680 | if (!is_gimple_assign (stmt)) | |
681 | return NULL_TREE; | |
682 | ||
683 | if (gimple_assign_rhs_code (stmt) == opcode) | |
684 | return gimple_assign_rhs1 (stmt); | |
685 | return NULL_TREE; | |
686 | } | |
687 | ||
688 | /* If CURR and LAST are a pair of ops that OPCODE allows us to | |
689 | eliminate through equivalences, do so, remove them from OPS, and | |
690 | return true. Otherwise, return false. */ | |
691 | ||
692 | static bool | |
693 | eliminate_duplicate_pair (enum tree_code opcode, | |
694 | vec<operand_entry_t> *ops, | |
695 | bool *all_done, | |
696 | unsigned int i, | |
697 | operand_entry_t curr, | |
698 | operand_entry_t last) | |
699 | { | |
700 | ||
701 | /* If we have two of the same op, and the opcode is & |, min, or max, | |
702 | we can eliminate one of them. | |
703 | If we have two of the same op, and the opcode is ^, we can | |
704 | eliminate both of them. */ | |
705 | ||
706 | if (last && last->op == curr->op) | |
707 | { | |
708 | switch (opcode) | |
709 | { | |
710 | case MAX_EXPR: | |
711 | case MIN_EXPR: | |
712 | case BIT_IOR_EXPR: | |
713 | case BIT_AND_EXPR: | |
714 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
715 | { | |
716 | fprintf (dump_file, "Equivalence: "); | |
717 | print_generic_expr (dump_file, curr->op, 0); | |
718 | fprintf (dump_file, " [&|minmax] "); | |
719 | print_generic_expr (dump_file, last->op, 0); | |
720 | fprintf (dump_file, " -> "); | |
721 | print_generic_stmt (dump_file, last->op, 0); | |
722 | } | |
723 | ||
724 | ops->ordered_remove (i); | |
725 | reassociate_stats.ops_eliminated ++; | |
726 | ||
727 | return true; | |
728 | ||
729 | case BIT_XOR_EXPR: | |
730 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
731 | { | |
732 | fprintf (dump_file, "Equivalence: "); | |
733 | print_generic_expr (dump_file, curr->op, 0); | |
734 | fprintf (dump_file, " ^ "); | |
735 | print_generic_expr (dump_file, last->op, 0); | |
736 | fprintf (dump_file, " -> nothing\n"); | |
737 | } | |
738 | ||
739 | reassociate_stats.ops_eliminated += 2; | |
740 | ||
741 | if (ops->length () == 2) | |
742 | { | |
743 | ops->create (0); | |
744 | add_to_ops_vec (ops, build_zero_cst (TREE_TYPE (last->op))); | |
745 | *all_done = true; | |
746 | } | |
747 | else | |
748 | { | |
749 | ops->ordered_remove (i-1); | |
750 | ops->ordered_remove (i-1); | |
751 | } | |
752 | ||
753 | return true; | |
754 | ||
755 | default: | |
756 | break; | |
757 | } | |
758 | } | |
759 | return false; | |
760 | } | |
761 | ||
762 | static vec<tree> plus_negates; | |
763 | ||
764 | /* If OPCODE is PLUS_EXPR, CURR->OP is a negate expression or a bitwise not | |
765 | expression, look in OPS for a corresponding positive operation to cancel | |
766 | it out. If we find one, remove the other from OPS, replace | |
767 | OPS[CURRINDEX] with 0 or -1, respectively, and return true. Otherwise, | |
768 | return false. */ | |
769 | ||
770 | static bool | |
771 | eliminate_plus_minus_pair (enum tree_code opcode, | |
772 | vec<operand_entry_t> *ops, | |
773 | unsigned int currindex, | |
774 | operand_entry_t curr) | |
775 | { | |
776 | tree negateop; | |
777 | tree notop; | |
778 | unsigned int i; | |
779 | operand_entry_t oe; | |
780 | ||
781 | if (opcode != PLUS_EXPR || TREE_CODE (curr->op) != SSA_NAME) | |
782 | return false; | |
783 | ||
784 | negateop = get_unary_op (curr->op, NEGATE_EXPR); | |
785 | notop = get_unary_op (curr->op, BIT_NOT_EXPR); | |
786 | if (negateop == NULL_TREE && notop == NULL_TREE) | |
787 | return false; | |
788 | ||
789 | /* Any non-negated version will have a rank that is one less than | |
790 | the current rank. So once we hit those ranks, if we don't find | |
791 | one, we can stop. */ | |
792 | ||
793 | for (i = currindex + 1; | |
794 | ops->iterate (i, &oe) | |
795 | && oe->rank >= curr->rank - 1 ; | |
796 | i++) | |
797 | { | |
798 | if (oe->op == negateop) | |
799 | { | |
800 | ||
801 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
802 | { | |
803 | fprintf (dump_file, "Equivalence: "); | |
804 | print_generic_expr (dump_file, negateop, 0); | |
805 | fprintf (dump_file, " + -"); | |
806 | print_generic_expr (dump_file, oe->op, 0); | |
807 | fprintf (dump_file, " -> 0\n"); | |
808 | } | |
809 | ||
810 | ops->ordered_remove (i); | |
811 | add_to_ops_vec (ops, build_zero_cst (TREE_TYPE (oe->op))); | |
812 | ops->ordered_remove (currindex); | |
813 | reassociate_stats.ops_eliminated ++; | |
814 | ||
815 | return true; | |
816 | } | |
817 | else if (oe->op == notop) | |
818 | { | |
819 | tree op_type = TREE_TYPE (oe->op); | |
820 | ||
821 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
822 | { | |
823 | fprintf (dump_file, "Equivalence: "); | |
824 | print_generic_expr (dump_file, notop, 0); | |
825 | fprintf (dump_file, " + ~"); | |
826 | print_generic_expr (dump_file, oe->op, 0); | |
827 | fprintf (dump_file, " -> -1\n"); | |
828 | } | |
829 | ||
830 | ops->ordered_remove (i); | |
831 | add_to_ops_vec (ops, build_int_cst_type (op_type, -1)); | |
832 | ops->ordered_remove (currindex); | |
833 | reassociate_stats.ops_eliminated ++; | |
834 | ||
835 | return true; | |
836 | } | |
837 | } | |
838 | ||
839 | /* CURR->OP is a negate expr in a plus expr: save it for later | |
840 | inspection in repropagate_negates(). */ | |
841 | if (negateop != NULL_TREE) | |
842 | plus_negates.safe_push (curr->op); | |
843 | ||
844 | return false; | |
845 | } | |
846 | ||
847 | /* If OPCODE is BIT_IOR_EXPR, BIT_AND_EXPR, and, CURR->OP is really a | |
848 | bitwise not expression, look in OPS for a corresponding operand to | |
849 | cancel it out. If we find one, remove the other from OPS, replace | |
850 | OPS[CURRINDEX] with 0, and return true. Otherwise, return | |
851 | false. */ | |
852 | ||
853 | static bool | |
854 | eliminate_not_pairs (enum tree_code opcode, | |
855 | vec<operand_entry_t> *ops, | |
856 | unsigned int currindex, | |
857 | operand_entry_t curr) | |
858 | { | |
859 | tree notop; | |
860 | unsigned int i; | |
861 | operand_entry_t oe; | |
862 | ||
863 | if ((opcode != BIT_IOR_EXPR && opcode != BIT_AND_EXPR) | |
864 | || TREE_CODE (curr->op) != SSA_NAME) | |
865 | return false; | |
866 | ||
867 | notop = get_unary_op (curr->op, BIT_NOT_EXPR); | |
868 | if (notop == NULL_TREE) | |
869 | return false; | |
870 | ||
871 | /* Any non-not version will have a rank that is one less than | |
872 | the current rank. So once we hit those ranks, if we don't find | |
873 | one, we can stop. */ | |
874 | ||
875 | for (i = currindex + 1; | |
876 | ops->iterate (i, &oe) | |
877 | && oe->rank >= curr->rank - 1; | |
878 | i++) | |
879 | { | |
880 | if (oe->op == notop) | |
881 | { | |
882 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
883 | { | |
884 | fprintf (dump_file, "Equivalence: "); | |
885 | print_generic_expr (dump_file, notop, 0); | |
886 | if (opcode == BIT_AND_EXPR) | |
887 | fprintf (dump_file, " & ~"); | |
888 | else if (opcode == BIT_IOR_EXPR) | |
889 | fprintf (dump_file, " | ~"); | |
890 | print_generic_expr (dump_file, oe->op, 0); | |
891 | if (opcode == BIT_AND_EXPR) | |
892 | fprintf (dump_file, " -> 0\n"); | |
893 | else if (opcode == BIT_IOR_EXPR) | |
894 | fprintf (dump_file, " -> -1\n"); | |
895 | } | |
896 | ||
897 | if (opcode == BIT_AND_EXPR) | |
898 | oe->op = build_zero_cst (TREE_TYPE (oe->op)); | |
899 | else if (opcode == BIT_IOR_EXPR) | |
900 | oe->op = build_all_ones_cst (TREE_TYPE (oe->op)); | |
901 | ||
902 | reassociate_stats.ops_eliminated += ops->length () - 1; | |
903 | ops->truncate (0); | |
904 | ops->quick_push (oe); | |
905 | return true; | |
906 | } | |
907 | } | |
908 | ||
909 | return false; | |
910 | } | |
911 | ||
912 | /* Use constant value that may be present in OPS to try to eliminate | |
913 | operands. Note that this function is only really used when we've | |
914 | eliminated ops for other reasons, or merged constants. Across | |
915 | single statements, fold already does all of this, plus more. There | |
916 | is little point in duplicating logic, so I've only included the | |
917 | identities that I could ever construct testcases to trigger. */ | |
918 | ||
919 | static void | |
920 | eliminate_using_constants (enum tree_code opcode, | |
921 | vec<operand_entry_t> *ops) | |
922 | { | |
923 | operand_entry_t oelast = ops->last (); | |
924 | tree type = TREE_TYPE (oelast->op); | |
925 | ||
926 | if (oelast->rank == 0 | |
927 | && (INTEGRAL_TYPE_P (type) || FLOAT_TYPE_P (type))) | |
928 | { | |
929 | switch (opcode) | |
930 | { | |
931 | case BIT_AND_EXPR: | |
932 | if (integer_zerop (oelast->op)) | |
933 | { | |
934 | if (ops->length () != 1) | |
935 | { | |
936 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
937 | fprintf (dump_file, "Found & 0, removing all other ops\n"); | |
938 | ||
939 | reassociate_stats.ops_eliminated += ops->length () - 1; | |
940 | ||
941 | ops->truncate (0); | |
942 | ops->quick_push (oelast); | |
943 | return; | |
944 | } | |
945 | } | |
946 | else if (integer_all_onesp (oelast->op)) | |
947 | { | |
948 | if (ops->length () != 1) | |
949 | { | |
950 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
951 | fprintf (dump_file, "Found & -1, removing\n"); | |
952 | ops->pop (); | |
953 | reassociate_stats.ops_eliminated++; | |
954 | } | |
955 | } | |
956 | break; | |
957 | case BIT_IOR_EXPR: | |
958 | if (integer_all_onesp (oelast->op)) | |
959 | { | |
960 | if (ops->length () != 1) | |
961 | { | |
962 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
963 | fprintf (dump_file, "Found | -1, removing all other ops\n"); | |
964 | ||
965 | reassociate_stats.ops_eliminated += ops->length () - 1; | |
966 | ||
967 | ops->truncate (0); | |
968 | ops->quick_push (oelast); | |
969 | return; | |
970 | } | |
971 | } | |
972 | else if (integer_zerop (oelast->op)) | |
973 | { | |
974 | if (ops->length () != 1) | |
975 | { | |
976 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
977 | fprintf (dump_file, "Found | 0, removing\n"); | |
978 | ops->pop (); | |
979 | reassociate_stats.ops_eliminated++; | |
980 | } | |
981 | } | |
982 | break; | |
983 | case MULT_EXPR: | |
984 | if (integer_zerop (oelast->op) | |
985 | || (FLOAT_TYPE_P (type) | |
986 | && !HONOR_NANS (type) | |
987 | && !HONOR_SIGNED_ZEROS (type) | |
988 | && real_zerop (oelast->op))) | |
989 | { | |
990 | if (ops->length () != 1) | |
991 | { | |
992 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
993 | fprintf (dump_file, "Found * 0, removing all other ops\n"); | |
994 | ||
995 | reassociate_stats.ops_eliminated += ops->length () - 1; | |
996 | ops->truncate (1); | |
997 | ops->quick_push (oelast); | |
998 | return; | |
999 | } | |
1000 | } | |
1001 | else if (integer_onep (oelast->op) | |
1002 | || (FLOAT_TYPE_P (type) | |
1003 | && !HONOR_SNANS (type) | |
1004 | && real_onep (oelast->op))) | |
1005 | { | |
1006 | if (ops->length () != 1) | |
1007 | { | |
1008 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1009 | fprintf (dump_file, "Found * 1, removing\n"); | |
1010 | ops->pop (); | |
1011 | reassociate_stats.ops_eliminated++; | |
1012 | return; | |
1013 | } | |
1014 | } | |
1015 | break; | |
1016 | case BIT_XOR_EXPR: | |
1017 | case PLUS_EXPR: | |
1018 | case MINUS_EXPR: | |
1019 | if (integer_zerop (oelast->op) | |
1020 | || (FLOAT_TYPE_P (type) | |
1021 | && (opcode == PLUS_EXPR || opcode == MINUS_EXPR) | |
1022 | && fold_real_zero_addition_p (type, oelast->op, | |
1023 | opcode == MINUS_EXPR))) | |
1024 | { | |
1025 | if (ops->length () != 1) | |
1026 | { | |
1027 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1028 | fprintf (dump_file, "Found [|^+] 0, removing\n"); | |
1029 | ops->pop (); | |
1030 | reassociate_stats.ops_eliminated++; | |
1031 | return; | |
1032 | } | |
1033 | } | |
1034 | break; | |
1035 | default: | |
1036 | break; | |
1037 | } | |
1038 | } | |
1039 | } | |
1040 | ||
1041 | ||
1042 | static void linearize_expr_tree (vec<operand_entry_t> *, gimple, | |
1043 | bool, bool); | |
1044 | ||
1045 | /* Structure for tracking and counting operands. */ | |
1046 | typedef struct oecount_s { | |
1047 | int cnt; | |
1048 | int id; | |
1049 | enum tree_code oecode; | |
1050 | tree op; | |
1051 | } oecount; | |
1052 | ||
1053 | ||
1054 | /* The heap for the oecount hashtable and the sorted list of operands. */ | |
1055 | static vec<oecount> cvec; | |
1056 | ||
1057 | ||
1058 | /* Oecount hashtable helpers. */ | |
1059 | ||
1060 | struct oecount_hasher | |
1061 | { | |
1062 | typedef int value_type; | |
1063 | typedef int compare_type; | |
1064 | typedef int store_values_directly; | |
1065 | static inline hashval_t hash (const value_type &); | |
1066 | static inline bool equal (const value_type &, const compare_type &); | |
1067 | static bool is_deleted (int &v) { return v == 1; } | |
1068 | static void mark_deleted (int &e) { e = 1; } | |
1069 | static bool is_empty (int &v) { return v == 0; } | |
1070 | static void mark_empty (int &e) { e = 0; } | |
1071 | static void remove (int &) {} | |
1072 | }; | |
1073 | ||
1074 | /* Hash function for oecount. */ | |
1075 | ||
1076 | inline hashval_t | |
1077 | oecount_hasher::hash (const value_type &p) | |
1078 | { | |
1079 | const oecount *c = &cvec[p - 42]; | |
1080 | return htab_hash_pointer (c->op) ^ (hashval_t)c->oecode; | |
1081 | } | |
1082 | ||
1083 | /* Comparison function for oecount. */ | |
1084 | ||
1085 | inline bool | |
1086 | oecount_hasher::equal (const value_type &p1, const compare_type &p2) | |
1087 | { | |
1088 | const oecount *c1 = &cvec[p1 - 42]; | |
1089 | const oecount *c2 = &cvec[p2 - 42]; | |
1090 | return (c1->oecode == c2->oecode | |
1091 | && c1->op == c2->op); | |
1092 | } | |
1093 | ||
1094 | /* Comparison function for qsort sorting oecount elements by count. */ | |
1095 | ||
1096 | static int | |
1097 | oecount_cmp (const void *p1, const void *p2) | |
1098 | { | |
1099 | const oecount *c1 = (const oecount *)p1; | |
1100 | const oecount *c2 = (const oecount *)p2; | |
1101 | if (c1->cnt != c2->cnt) | |
1102 | return c1->cnt - c2->cnt; | |
1103 | else | |
1104 | /* If counts are identical, use unique IDs to stabilize qsort. */ | |
1105 | return c1->id - c2->id; | |
1106 | } | |
1107 | ||
1108 | /* Return TRUE iff STMT represents a builtin call that raises OP | |
1109 | to some exponent. */ | |
1110 | ||
1111 | static bool | |
1112 | stmt_is_power_of_op (gimple stmt, tree op) | |
1113 | { | |
1114 | tree fndecl; | |
1115 | ||
1116 | if (!is_gimple_call (stmt)) | |
1117 | return false; | |
1118 | ||
1119 | fndecl = gimple_call_fndecl (stmt); | |
1120 | ||
1121 | if (!fndecl | |
1122 | || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL) | |
1123 | return false; | |
1124 | ||
1125 | switch (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))) | |
1126 | { | |
1127 | CASE_FLT_FN (BUILT_IN_POW): | |
1128 | CASE_FLT_FN (BUILT_IN_POWI): | |
1129 | return (operand_equal_p (gimple_call_arg (stmt, 0), op, 0)); | |
1130 | ||
1131 | default: | |
1132 | return false; | |
1133 | } | |
1134 | } | |
1135 | ||
1136 | /* Given STMT which is a __builtin_pow* call, decrement its exponent | |
1137 | in place and return the result. Assumes that stmt_is_power_of_op | |
1138 | was previously called for STMT and returned TRUE. */ | |
1139 | ||
1140 | static HOST_WIDE_INT | |
1141 | decrement_power (gimple stmt) | |
1142 | { | |
1143 | REAL_VALUE_TYPE c, cint; | |
1144 | HOST_WIDE_INT power; | |
1145 | tree arg1; | |
1146 | ||
1147 | switch (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt))) | |
1148 | { | |
1149 | CASE_FLT_FN (BUILT_IN_POW): | |
1150 | arg1 = gimple_call_arg (stmt, 1); | |
1151 | c = TREE_REAL_CST (arg1); | |
1152 | power = real_to_integer (&c) - 1; | |
1153 | real_from_integer (&cint, VOIDmode, power, SIGNED); | |
1154 | gimple_call_set_arg (stmt, 1, build_real (TREE_TYPE (arg1), cint)); | |
1155 | return power; | |
1156 | ||
1157 | CASE_FLT_FN (BUILT_IN_POWI): | |
1158 | arg1 = gimple_call_arg (stmt, 1); | |
1159 | power = TREE_INT_CST_LOW (arg1) - 1; | |
1160 | gimple_call_set_arg (stmt, 1, build_int_cst (TREE_TYPE (arg1), power)); | |
1161 | return power; | |
1162 | ||
1163 | default: | |
1164 | gcc_unreachable (); | |
1165 | } | |
1166 | } | |
1167 | ||
1168 | /* Find the single immediate use of STMT's LHS, and replace it | |
1169 | with OP. Remove STMT. If STMT's LHS is the same as *DEF, | |
1170 | replace *DEF with OP as well. */ | |
1171 | ||
1172 | static void | |
1173 | propagate_op_to_single_use (tree op, gimple stmt, tree *def) | |
1174 | { | |
1175 | tree lhs; | |
1176 | gimple use_stmt; | |
1177 | use_operand_p use; | |
1178 | gimple_stmt_iterator gsi; | |
1179 | ||
1180 | if (is_gimple_call (stmt)) | |
1181 | lhs = gimple_call_lhs (stmt); | |
1182 | else | |
1183 | lhs = gimple_assign_lhs (stmt); | |
1184 | ||
1185 | gcc_assert (has_single_use (lhs)); | |
1186 | single_imm_use (lhs, &use, &use_stmt); | |
1187 | if (lhs == *def) | |
1188 | *def = op; | |
1189 | SET_USE (use, op); | |
1190 | if (TREE_CODE (op) != SSA_NAME) | |
1191 | update_stmt (use_stmt); | |
1192 | gsi = gsi_for_stmt (stmt); | |
1193 | unlink_stmt_vdef (stmt); | |
1194 | reassoc_remove_stmt (&gsi); | |
1195 | release_defs (stmt); | |
1196 | } | |
1197 | ||
1198 | /* Walks the linear chain with result *DEF searching for an operation | |
1199 | with operand OP and code OPCODE removing that from the chain. *DEF | |
1200 | is updated if there is only one operand but no operation left. */ | |
1201 | ||
1202 | static void | |
1203 | zero_one_operation (tree *def, enum tree_code opcode, tree op) | |
1204 | { | |
1205 | gimple stmt = SSA_NAME_DEF_STMT (*def); | |
1206 | ||
1207 | do | |
1208 | { | |
1209 | tree name; | |
1210 | ||
1211 | if (opcode == MULT_EXPR | |
1212 | && stmt_is_power_of_op (stmt, op)) | |
1213 | { | |
1214 | if (decrement_power (stmt) == 1) | |
1215 | propagate_op_to_single_use (op, stmt, def); | |
1216 | return; | |
1217 | } | |
1218 | ||
1219 | name = gimple_assign_rhs1 (stmt); | |
1220 | ||
1221 | /* If this is the operation we look for and one of the operands | |
1222 | is ours simply propagate the other operand into the stmts | |
1223 | single use. */ | |
1224 | if (gimple_assign_rhs_code (stmt) == opcode | |
1225 | && (name == op | |
1226 | || gimple_assign_rhs2 (stmt) == op)) | |
1227 | { | |
1228 | if (name == op) | |
1229 | name = gimple_assign_rhs2 (stmt); | |
1230 | propagate_op_to_single_use (name, stmt, def); | |
1231 | return; | |
1232 | } | |
1233 | ||
1234 | /* We might have a multiply of two __builtin_pow* calls, and | |
1235 | the operand might be hiding in the rightmost one. */ | |
1236 | if (opcode == MULT_EXPR | |
1237 | && gimple_assign_rhs_code (stmt) == opcode | |
1238 | && TREE_CODE (gimple_assign_rhs2 (stmt)) == SSA_NAME | |
1239 | && has_single_use (gimple_assign_rhs2 (stmt))) | |
1240 | { | |
1241 | gimple stmt2 = SSA_NAME_DEF_STMT (gimple_assign_rhs2 (stmt)); | |
1242 | if (stmt_is_power_of_op (stmt2, op)) | |
1243 | { | |
1244 | if (decrement_power (stmt2) == 1) | |
1245 | propagate_op_to_single_use (op, stmt2, def); | |
1246 | return; | |
1247 | } | |
1248 | } | |
1249 | ||
1250 | /* Continue walking the chain. */ | |
1251 | gcc_assert (name != op | |
1252 | && TREE_CODE (name) == SSA_NAME); | |
1253 | stmt = SSA_NAME_DEF_STMT (name); | |
1254 | } | |
1255 | while (1); | |
1256 | } | |
1257 | ||
1258 | /* Returns true if statement S1 dominates statement S2. Like | |
1259 | stmt_dominates_stmt_p, but uses stmt UIDs to optimize. */ | |
1260 | ||
1261 | static bool | |
1262 | reassoc_stmt_dominates_stmt_p (gimple s1, gimple s2) | |
1263 | { | |
1264 | basic_block bb1 = gimple_bb (s1), bb2 = gimple_bb (s2); | |
1265 | ||
1266 | /* If bb1 is NULL, it should be a GIMPLE_NOP def stmt of an (D) | |
1267 | SSA_NAME. Assume it lives at the beginning of function and | |
1268 | thus dominates everything. */ | |
1269 | if (!bb1 || s1 == s2) | |
1270 | return true; | |
1271 | ||
1272 | /* If bb2 is NULL, it doesn't dominate any stmt with a bb. */ | |
1273 | if (!bb2) | |
1274 | return false; | |
1275 | ||
1276 | if (bb1 == bb2) | |
1277 | { | |
1278 | /* PHIs in the same basic block are assumed to be | |
1279 | executed all in parallel, if only one stmt is a PHI, | |
1280 | it dominates the other stmt in the same basic block. */ | |
1281 | if (gimple_code (s1) == GIMPLE_PHI) | |
1282 | return true; | |
1283 | ||
1284 | if (gimple_code (s2) == GIMPLE_PHI) | |
1285 | return false; | |
1286 | ||
1287 | gcc_assert (gimple_uid (s1) && gimple_uid (s2)); | |
1288 | ||
1289 | if (gimple_uid (s1) < gimple_uid (s2)) | |
1290 | return true; | |
1291 | ||
1292 | if (gimple_uid (s1) > gimple_uid (s2)) | |
1293 | return false; | |
1294 | ||
1295 | gimple_stmt_iterator gsi = gsi_for_stmt (s1); | |
1296 | unsigned int uid = gimple_uid (s1); | |
1297 | for (gsi_next (&gsi); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1298 | { | |
1299 | gimple s = gsi_stmt (gsi); | |
1300 | if (gimple_uid (s) != uid) | |
1301 | break; | |
1302 | if (s == s2) | |
1303 | return true; | |
1304 | } | |
1305 | ||
1306 | return false; | |
1307 | } | |
1308 | ||
1309 | return dominated_by_p (CDI_DOMINATORS, bb2, bb1); | |
1310 | } | |
1311 | ||
1312 | /* Insert STMT after INSERT_POINT. */ | |
1313 | ||
1314 | static void | |
1315 | insert_stmt_after (gimple stmt, gimple insert_point) | |
1316 | { | |
1317 | gimple_stmt_iterator gsi; | |
1318 | basic_block bb; | |
1319 | ||
1320 | if (gimple_code (insert_point) == GIMPLE_PHI) | |
1321 | bb = gimple_bb (insert_point); | |
1322 | else if (!stmt_ends_bb_p (insert_point)) | |
1323 | { | |
1324 | gsi = gsi_for_stmt (insert_point); | |
1325 | gimple_set_uid (stmt, gimple_uid (insert_point)); | |
1326 | gsi_insert_after (&gsi, stmt, GSI_NEW_STMT); | |
1327 | return; | |
1328 | } | |
1329 | else | |
1330 | /* We assume INSERT_POINT is a SSA_NAME_DEF_STMT of some SSA_NAME, | |
1331 | thus if it must end a basic block, it should be a call that can | |
1332 | throw, or some assignment that can throw. If it throws, the LHS | |
1333 | of it will not be initialized though, so only valid places using | |
1334 | the SSA_NAME should be dominated by the fallthru edge. */ | |
1335 | bb = find_fallthru_edge (gimple_bb (insert_point)->succs)->dest; | |
1336 | gsi = gsi_after_labels (bb); | |
1337 | if (gsi_end_p (gsi)) | |
1338 | { | |
1339 | gimple_stmt_iterator gsi2 = gsi_last_bb (bb); | |
1340 | gimple_set_uid (stmt, | |
1341 | gsi_end_p (gsi2) ? 1 : gimple_uid (gsi_stmt (gsi2))); | |
1342 | } | |
1343 | else | |
1344 | gimple_set_uid (stmt, gimple_uid (gsi_stmt (gsi))); | |
1345 | gsi_insert_before (&gsi, stmt, GSI_SAME_STMT); | |
1346 | } | |
1347 | ||
1348 | /* Builds one statement performing OP1 OPCODE OP2 using TMPVAR for | |
1349 | the result. Places the statement after the definition of either | |
1350 | OP1 or OP2. Returns the new statement. */ | |
1351 | ||
1352 | static gimple | |
1353 | build_and_add_sum (tree type, tree op1, tree op2, enum tree_code opcode) | |
1354 | { | |
1355 | gimple op1def = NULL, op2def = NULL; | |
1356 | gimple_stmt_iterator gsi; | |
1357 | tree op; | |
1358 | gassign *sum; | |
1359 | ||
1360 | /* Create the addition statement. */ | |
1361 | op = make_ssa_name (type); | |
1362 | sum = gimple_build_assign (op, opcode, op1, op2); | |
1363 | ||
1364 | /* Find an insertion place and insert. */ | |
1365 | if (TREE_CODE (op1) == SSA_NAME) | |
1366 | op1def = SSA_NAME_DEF_STMT (op1); | |
1367 | if (TREE_CODE (op2) == SSA_NAME) | |
1368 | op2def = SSA_NAME_DEF_STMT (op2); | |
1369 | if ((!op1def || gimple_nop_p (op1def)) | |
1370 | && (!op2def || gimple_nop_p (op2def))) | |
1371 | { | |
1372 | gsi = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))); | |
1373 | if (gsi_end_p (gsi)) | |
1374 | { | |
1375 | gimple_stmt_iterator gsi2 | |
1376 | = gsi_last_bb (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))); | |
1377 | gimple_set_uid (sum, | |
1378 | gsi_end_p (gsi2) ? 1 : gimple_uid (gsi_stmt (gsi2))); | |
1379 | } | |
1380 | else | |
1381 | gimple_set_uid (sum, gimple_uid (gsi_stmt (gsi))); | |
1382 | gsi_insert_before (&gsi, sum, GSI_NEW_STMT); | |
1383 | } | |
1384 | else | |
1385 | { | |
1386 | gimple insert_point; | |
1387 | if ((!op1def || gimple_nop_p (op1def)) | |
1388 | || (op2def && !gimple_nop_p (op2def) | |
1389 | && reassoc_stmt_dominates_stmt_p (op1def, op2def))) | |
1390 | insert_point = op2def; | |
1391 | else | |
1392 | insert_point = op1def; | |
1393 | insert_stmt_after (sum, insert_point); | |
1394 | } | |
1395 | update_stmt (sum); | |
1396 | ||
1397 | return sum; | |
1398 | } | |
1399 | ||
1400 | /* Perform un-distribution of divisions and multiplications. | |
1401 | A * X + B * X is transformed into (A + B) * X and A / X + B / X | |
1402 | to (A + B) / X for real X. | |
1403 | ||
1404 | The algorithm is organized as follows. | |
1405 | ||
1406 | - First we walk the addition chain *OPS looking for summands that | |
1407 | are defined by a multiplication or a real division. This results | |
1408 | in the candidates bitmap with relevant indices into *OPS. | |
1409 | ||
1410 | - Second we build the chains of multiplications or divisions for | |
1411 | these candidates, counting the number of occurrences of (operand, code) | |
1412 | pairs in all of the candidates chains. | |
1413 | ||
1414 | - Third we sort the (operand, code) pairs by number of occurrence and | |
1415 | process them starting with the pair with the most uses. | |
1416 | ||
1417 | * For each such pair we walk the candidates again to build a | |
1418 | second candidate bitmap noting all multiplication/division chains | |
1419 | that have at least one occurrence of (operand, code). | |
1420 | ||
1421 | * We build an alternate addition chain only covering these | |
1422 | candidates with one (operand, code) operation removed from their | |
1423 | multiplication/division chain. | |
1424 | ||
1425 | * The first candidate gets replaced by the alternate addition chain | |
1426 | multiplied/divided by the operand. | |
1427 | ||
1428 | * All candidate chains get disabled for further processing and | |
1429 | processing of (operand, code) pairs continues. | |
1430 | ||
1431 | The alternate addition chains built are re-processed by the main | |
1432 | reassociation algorithm which allows optimizing a * x * y + b * y * x | |
1433 | to (a + b ) * x * y in one invocation of the reassociation pass. */ | |
1434 | ||
1435 | static bool | |
1436 | undistribute_ops_list (enum tree_code opcode, | |
1437 | vec<operand_entry_t> *ops, struct loop *loop) | |
1438 | { | |
1439 | unsigned int length = ops->length (); | |
1440 | operand_entry_t oe1; | |
1441 | unsigned i, j; | |
1442 | sbitmap candidates, candidates2; | |
1443 | unsigned nr_candidates, nr_candidates2; | |
1444 | sbitmap_iterator sbi0; | |
1445 | vec<operand_entry_t> *subops; | |
1446 | bool changed = false; | |
1447 | int next_oecount_id = 0; | |
1448 | ||
1449 | if (length <= 1 | |
1450 | || opcode != PLUS_EXPR) | |
1451 | return false; | |
1452 | ||
1453 | /* Build a list of candidates to process. */ | |
1454 | candidates = sbitmap_alloc (length); | |
1455 | bitmap_clear (candidates); | |
1456 | nr_candidates = 0; | |
1457 | FOR_EACH_VEC_ELT (*ops, i, oe1) | |
1458 | { | |
1459 | enum tree_code dcode; | |
1460 | gimple oe1def; | |
1461 | ||
1462 | if (TREE_CODE (oe1->op) != SSA_NAME) | |
1463 | continue; | |
1464 | oe1def = SSA_NAME_DEF_STMT (oe1->op); | |
1465 | if (!is_gimple_assign (oe1def)) | |
1466 | continue; | |
1467 | dcode = gimple_assign_rhs_code (oe1def); | |
1468 | if ((dcode != MULT_EXPR | |
1469 | && dcode != RDIV_EXPR) | |
1470 | || !is_reassociable_op (oe1def, dcode, loop)) | |
1471 | continue; | |
1472 | ||
1473 | bitmap_set_bit (candidates, i); | |
1474 | nr_candidates++; | |
1475 | } | |
1476 | ||
1477 | if (nr_candidates < 2) | |
1478 | { | |
1479 | sbitmap_free (candidates); | |
1480 | return false; | |
1481 | } | |
1482 | ||
1483 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1484 | { | |
1485 | fprintf (dump_file, "searching for un-distribute opportunities "); | |
1486 | print_generic_expr (dump_file, | |
1487 | (*ops)[bitmap_first_set_bit (candidates)]->op, 0); | |
1488 | fprintf (dump_file, " %d\n", nr_candidates); | |
1489 | } | |
1490 | ||
1491 | /* Build linearized sub-operand lists and the counting table. */ | |
1492 | cvec.create (0); | |
1493 | ||
1494 | hash_table<oecount_hasher> ctable (15); | |
1495 | ||
1496 | /* ??? Macro arguments cannot have multi-argument template types in | |
1497 | them. This typedef is needed to workaround that limitation. */ | |
1498 | typedef vec<operand_entry_t> vec_operand_entry_t_heap; | |
1499 | subops = XCNEWVEC (vec_operand_entry_t_heap, ops->length ()); | |
1500 | EXECUTE_IF_SET_IN_BITMAP (candidates, 0, i, sbi0) | |
1501 | { | |
1502 | gimple oedef; | |
1503 | enum tree_code oecode; | |
1504 | unsigned j; | |
1505 | ||
1506 | oedef = SSA_NAME_DEF_STMT ((*ops)[i]->op); | |
1507 | oecode = gimple_assign_rhs_code (oedef); | |
1508 | linearize_expr_tree (&subops[i], oedef, | |
1509 | associative_tree_code (oecode), false); | |
1510 | ||
1511 | FOR_EACH_VEC_ELT (subops[i], j, oe1) | |
1512 | { | |
1513 | oecount c; | |
1514 | int *slot; | |
1515 | int idx; | |
1516 | c.oecode = oecode; | |
1517 | c.cnt = 1; | |
1518 | c.id = next_oecount_id++; | |
1519 | c.op = oe1->op; | |
1520 | cvec.safe_push (c); | |
1521 | idx = cvec.length () + 41; | |
1522 | slot = ctable.find_slot (idx, INSERT); | |
1523 | if (!*slot) | |
1524 | { | |
1525 | *slot = idx; | |
1526 | } | |
1527 | else | |
1528 | { | |
1529 | cvec.pop (); | |
1530 | cvec[*slot - 42].cnt++; | |
1531 | } | |
1532 | } | |
1533 | } | |
1534 | ||
1535 | /* Sort the counting table. */ | |
1536 | cvec.qsort (oecount_cmp); | |
1537 | ||
1538 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1539 | { | |
1540 | oecount *c; | |
1541 | fprintf (dump_file, "Candidates:\n"); | |
1542 | FOR_EACH_VEC_ELT (cvec, j, c) | |
1543 | { | |
1544 | fprintf (dump_file, " %u %s: ", c->cnt, | |
1545 | c->oecode == MULT_EXPR | |
1546 | ? "*" : c->oecode == RDIV_EXPR ? "/" : "?"); | |
1547 | print_generic_expr (dump_file, c->op, 0); | |
1548 | fprintf (dump_file, "\n"); | |
1549 | } | |
1550 | } | |
1551 | ||
1552 | /* Process the (operand, code) pairs in order of most occurrence. */ | |
1553 | candidates2 = sbitmap_alloc (length); | |
1554 | while (!cvec.is_empty ()) | |
1555 | { | |
1556 | oecount *c = &cvec.last (); | |
1557 | if (c->cnt < 2) | |
1558 | break; | |
1559 | ||
1560 | /* Now collect the operands in the outer chain that contain | |
1561 | the common operand in their inner chain. */ | |
1562 | bitmap_clear (candidates2); | |
1563 | nr_candidates2 = 0; | |
1564 | EXECUTE_IF_SET_IN_BITMAP (candidates, 0, i, sbi0) | |
1565 | { | |
1566 | gimple oedef; | |
1567 | enum tree_code oecode; | |
1568 | unsigned j; | |
1569 | tree op = (*ops)[i]->op; | |
1570 | ||
1571 | /* If we undistributed in this chain already this may be | |
1572 | a constant. */ | |
1573 | if (TREE_CODE (op) != SSA_NAME) | |
1574 | continue; | |
1575 | ||
1576 | oedef = SSA_NAME_DEF_STMT (op); | |
1577 | oecode = gimple_assign_rhs_code (oedef); | |
1578 | if (oecode != c->oecode) | |
1579 | continue; | |
1580 | ||
1581 | FOR_EACH_VEC_ELT (subops[i], j, oe1) | |
1582 | { | |
1583 | if (oe1->op == c->op) | |
1584 | { | |
1585 | bitmap_set_bit (candidates2, i); | |
1586 | ++nr_candidates2; | |
1587 | break; | |
1588 | } | |
1589 | } | |
1590 | } | |
1591 | ||
1592 | if (nr_candidates2 >= 2) | |
1593 | { | |
1594 | operand_entry_t oe1, oe2; | |
1595 | gimple prod; | |
1596 | int first = bitmap_first_set_bit (candidates2); | |
1597 | ||
1598 | /* Build the new addition chain. */ | |
1599 | oe1 = (*ops)[first]; | |
1600 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1601 | { | |
1602 | fprintf (dump_file, "Building ("); | |
1603 | print_generic_expr (dump_file, oe1->op, 0); | |
1604 | } | |
1605 | zero_one_operation (&oe1->op, c->oecode, c->op); | |
1606 | EXECUTE_IF_SET_IN_BITMAP (candidates2, first+1, i, sbi0) | |
1607 | { | |
1608 | gimple sum; | |
1609 | oe2 = (*ops)[i]; | |
1610 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1611 | { | |
1612 | fprintf (dump_file, " + "); | |
1613 | print_generic_expr (dump_file, oe2->op, 0); | |
1614 | } | |
1615 | zero_one_operation (&oe2->op, c->oecode, c->op); | |
1616 | sum = build_and_add_sum (TREE_TYPE (oe1->op), | |
1617 | oe1->op, oe2->op, opcode); | |
1618 | oe2->op = build_zero_cst (TREE_TYPE (oe2->op)); | |
1619 | oe2->rank = 0; | |
1620 | oe1->op = gimple_get_lhs (sum); | |
1621 | } | |
1622 | ||
1623 | /* Apply the multiplication/division. */ | |
1624 | prod = build_and_add_sum (TREE_TYPE (oe1->op), | |
1625 | oe1->op, c->op, c->oecode); | |
1626 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1627 | { | |
1628 | fprintf (dump_file, ") %s ", c->oecode == MULT_EXPR ? "*" : "/"); | |
1629 | print_generic_expr (dump_file, c->op, 0); | |
1630 | fprintf (dump_file, "\n"); | |
1631 | } | |
1632 | ||
1633 | /* Record it in the addition chain and disable further | |
1634 | undistribution with this op. */ | |
1635 | oe1->op = gimple_assign_lhs (prod); | |
1636 | oe1->rank = get_rank (oe1->op); | |
1637 | subops[first].release (); | |
1638 | ||
1639 | changed = true; | |
1640 | } | |
1641 | ||
1642 | cvec.pop (); | |
1643 | } | |
1644 | ||
1645 | for (i = 0; i < ops->length (); ++i) | |
1646 | subops[i].release (); | |
1647 | free (subops); | |
1648 | cvec.release (); | |
1649 | sbitmap_free (candidates); | |
1650 | sbitmap_free (candidates2); | |
1651 | ||
1652 | return changed; | |
1653 | } | |
1654 | ||
1655 | /* If OPCODE is BIT_IOR_EXPR or BIT_AND_EXPR and CURR is a comparison | |
1656 | expression, examine the other OPS to see if any of them are comparisons | |
1657 | of the same values, which we may be able to combine or eliminate. | |
1658 | For example, we can rewrite (a < b) | (a == b) as (a <= b). */ | |
1659 | ||
1660 | static bool | |
1661 | eliminate_redundant_comparison (enum tree_code opcode, | |
1662 | vec<operand_entry_t> *ops, | |
1663 | unsigned int currindex, | |
1664 | operand_entry_t curr) | |
1665 | { | |
1666 | tree op1, op2; | |
1667 | enum tree_code lcode, rcode; | |
1668 | gimple def1, def2; | |
1669 | int i; | |
1670 | operand_entry_t oe; | |
1671 | ||
1672 | if (opcode != BIT_IOR_EXPR && opcode != BIT_AND_EXPR) | |
1673 | return false; | |
1674 | ||
1675 | /* Check that CURR is a comparison. */ | |
1676 | if (TREE_CODE (curr->op) != SSA_NAME) | |
1677 | return false; | |
1678 | def1 = SSA_NAME_DEF_STMT (curr->op); | |
1679 | if (!is_gimple_assign (def1)) | |
1680 | return false; | |
1681 | lcode = gimple_assign_rhs_code (def1); | |
1682 | if (TREE_CODE_CLASS (lcode) != tcc_comparison) | |
1683 | return false; | |
1684 | op1 = gimple_assign_rhs1 (def1); | |
1685 | op2 = gimple_assign_rhs2 (def1); | |
1686 | ||
1687 | /* Now look for a similar comparison in the remaining OPS. */ | |
1688 | for (i = currindex + 1; ops->iterate (i, &oe); i++) | |
1689 | { | |
1690 | tree t; | |
1691 | ||
1692 | if (TREE_CODE (oe->op) != SSA_NAME) | |
1693 | continue; | |
1694 | def2 = SSA_NAME_DEF_STMT (oe->op); | |
1695 | if (!is_gimple_assign (def2)) | |
1696 | continue; | |
1697 | rcode = gimple_assign_rhs_code (def2); | |
1698 | if (TREE_CODE_CLASS (rcode) != tcc_comparison) | |
1699 | continue; | |
1700 | ||
1701 | /* If we got here, we have a match. See if we can combine the | |
1702 | two comparisons. */ | |
1703 | if (opcode == BIT_IOR_EXPR) | |
1704 | t = maybe_fold_or_comparisons (lcode, op1, op2, | |
1705 | rcode, gimple_assign_rhs1 (def2), | |
1706 | gimple_assign_rhs2 (def2)); | |
1707 | else | |
1708 | t = maybe_fold_and_comparisons (lcode, op1, op2, | |
1709 | rcode, gimple_assign_rhs1 (def2), | |
1710 | gimple_assign_rhs2 (def2)); | |
1711 | if (!t) | |
1712 | continue; | |
1713 | ||
1714 | /* maybe_fold_and_comparisons and maybe_fold_or_comparisons | |
1715 | always give us a boolean_type_node value back. If the original | |
1716 | BIT_AND_EXPR or BIT_IOR_EXPR was of a wider integer type, | |
1717 | we need to convert. */ | |
1718 | if (!useless_type_conversion_p (TREE_TYPE (curr->op), TREE_TYPE (t))) | |
1719 | t = fold_convert (TREE_TYPE (curr->op), t); | |
1720 | ||
1721 | if (TREE_CODE (t) != INTEGER_CST | |
1722 | && !operand_equal_p (t, curr->op, 0)) | |
1723 | { | |
1724 | enum tree_code subcode; | |
1725 | tree newop1, newop2; | |
1726 | if (!COMPARISON_CLASS_P (t)) | |
1727 | continue; | |
1728 | extract_ops_from_tree (t, &subcode, &newop1, &newop2); | |
1729 | STRIP_USELESS_TYPE_CONVERSION (newop1); | |
1730 | STRIP_USELESS_TYPE_CONVERSION (newop2); | |
1731 | if (!is_gimple_val (newop1) || !is_gimple_val (newop2)) | |
1732 | continue; | |
1733 | } | |
1734 | ||
1735 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1736 | { | |
1737 | fprintf (dump_file, "Equivalence: "); | |
1738 | print_generic_expr (dump_file, curr->op, 0); | |
1739 | fprintf (dump_file, " %s ", op_symbol_code (opcode)); | |
1740 | print_generic_expr (dump_file, oe->op, 0); | |
1741 | fprintf (dump_file, " -> "); | |
1742 | print_generic_expr (dump_file, t, 0); | |
1743 | fprintf (dump_file, "\n"); | |
1744 | } | |
1745 | ||
1746 | /* Now we can delete oe, as it has been subsumed by the new combined | |
1747 | expression t. */ | |
1748 | ops->ordered_remove (i); | |
1749 | reassociate_stats.ops_eliminated ++; | |
1750 | ||
1751 | /* If t is the same as curr->op, we're done. Otherwise we must | |
1752 | replace curr->op with t. Special case is if we got a constant | |
1753 | back, in which case we add it to the end instead of in place of | |
1754 | the current entry. */ | |
1755 | if (TREE_CODE (t) == INTEGER_CST) | |
1756 | { | |
1757 | ops->ordered_remove (currindex); | |
1758 | add_to_ops_vec (ops, t); | |
1759 | } | |
1760 | else if (!operand_equal_p (t, curr->op, 0)) | |
1761 | { | |
1762 | gimple sum; | |
1763 | enum tree_code subcode; | |
1764 | tree newop1; | |
1765 | tree newop2; | |
1766 | gcc_assert (COMPARISON_CLASS_P (t)); | |
1767 | extract_ops_from_tree (t, &subcode, &newop1, &newop2); | |
1768 | STRIP_USELESS_TYPE_CONVERSION (newop1); | |
1769 | STRIP_USELESS_TYPE_CONVERSION (newop2); | |
1770 | gcc_checking_assert (is_gimple_val (newop1) | |
1771 | && is_gimple_val (newop2)); | |
1772 | sum = build_and_add_sum (TREE_TYPE (t), newop1, newop2, subcode); | |
1773 | curr->op = gimple_get_lhs (sum); | |
1774 | } | |
1775 | return true; | |
1776 | } | |
1777 | ||
1778 | return false; | |
1779 | } | |
1780 | ||
1781 | /* Perform various identities and other optimizations on the list of | |
1782 | operand entries, stored in OPS. The tree code for the binary | |
1783 | operation between all the operands is OPCODE. */ | |
1784 | ||
1785 | static void | |
1786 | optimize_ops_list (enum tree_code opcode, | |
1787 | vec<operand_entry_t> *ops) | |
1788 | { | |
1789 | unsigned int length = ops->length (); | |
1790 | unsigned int i; | |
1791 | operand_entry_t oe; | |
1792 | operand_entry_t oelast = NULL; | |
1793 | bool iterate = false; | |
1794 | ||
1795 | if (length == 1) | |
1796 | return; | |
1797 | ||
1798 | oelast = ops->last (); | |
1799 | ||
1800 | /* If the last two are constants, pop the constants off, merge them | |
1801 | and try the next two. */ | |
1802 | if (oelast->rank == 0 && is_gimple_min_invariant (oelast->op)) | |
1803 | { | |
1804 | operand_entry_t oelm1 = (*ops)[length - 2]; | |
1805 | ||
1806 | if (oelm1->rank == 0 | |
1807 | && is_gimple_min_invariant (oelm1->op) | |
1808 | && useless_type_conversion_p (TREE_TYPE (oelm1->op), | |
1809 | TREE_TYPE (oelast->op))) | |
1810 | { | |
1811 | tree folded = fold_binary (opcode, TREE_TYPE (oelm1->op), | |
1812 | oelm1->op, oelast->op); | |
1813 | ||
1814 | if (folded && is_gimple_min_invariant (folded)) | |
1815 | { | |
1816 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1817 | fprintf (dump_file, "Merging constants\n"); | |
1818 | ||
1819 | ops->pop (); | |
1820 | ops->pop (); | |
1821 | ||
1822 | add_to_ops_vec (ops, folded); | |
1823 | reassociate_stats.constants_eliminated++; | |
1824 | ||
1825 | optimize_ops_list (opcode, ops); | |
1826 | return; | |
1827 | } | |
1828 | } | |
1829 | } | |
1830 | ||
1831 | eliminate_using_constants (opcode, ops); | |
1832 | oelast = NULL; | |
1833 | ||
1834 | for (i = 0; ops->iterate (i, &oe);) | |
1835 | { | |
1836 | bool done = false; | |
1837 | ||
1838 | if (eliminate_not_pairs (opcode, ops, i, oe)) | |
1839 | return; | |
1840 | if (eliminate_duplicate_pair (opcode, ops, &done, i, oe, oelast) | |
1841 | || (!done && eliminate_plus_minus_pair (opcode, ops, i, oe)) | |
1842 | || (!done && eliminate_redundant_comparison (opcode, ops, i, oe))) | |
1843 | { | |
1844 | if (done) | |
1845 | return; | |
1846 | iterate = true; | |
1847 | oelast = NULL; | |
1848 | continue; | |
1849 | } | |
1850 | oelast = oe; | |
1851 | i++; | |
1852 | } | |
1853 | ||
1854 | length = ops->length (); | |
1855 | oelast = ops->last (); | |
1856 | ||
1857 | if (iterate) | |
1858 | optimize_ops_list (opcode, ops); | |
1859 | } | |
1860 | ||
1861 | /* The following functions are subroutines to optimize_range_tests and allow | |
1862 | it to try to change a logical combination of comparisons into a range | |
1863 | test. | |
1864 | ||
1865 | For example, both | |
1866 | X == 2 || X == 5 || X == 3 || X == 4 | |
1867 | and | |
1868 | X >= 2 && X <= 5 | |
1869 | are converted to | |
1870 | (unsigned) (X - 2) <= 3 | |
1871 | ||
1872 | For more information see comments above fold_test_range in fold-const.c, | |
1873 | this implementation is for GIMPLE. */ | |
1874 | ||
1875 | struct range_entry | |
1876 | { | |
1877 | tree exp; | |
1878 | tree low; | |
1879 | tree high; | |
1880 | bool in_p; | |
1881 | bool strict_overflow_p; | |
1882 | unsigned int idx, next; | |
1883 | }; | |
1884 | ||
1885 | /* This is similar to make_range in fold-const.c, but on top of | |
1886 | GIMPLE instead of trees. If EXP is non-NULL, it should be | |
1887 | an SSA_NAME and STMT argument is ignored, otherwise STMT | |
1888 | argument should be a GIMPLE_COND. */ | |
1889 | ||
1890 | static void | |
1891 | init_range_entry (struct range_entry *r, tree exp, gimple stmt) | |
1892 | { | |
1893 | int in_p; | |
1894 | tree low, high; | |
1895 | bool is_bool, strict_overflow_p; | |
1896 | ||
1897 | r->exp = NULL_TREE; | |
1898 | r->in_p = false; | |
1899 | r->strict_overflow_p = false; | |
1900 | r->low = NULL_TREE; | |
1901 | r->high = NULL_TREE; | |
1902 | if (exp != NULL_TREE | |
1903 | && (TREE_CODE (exp) != SSA_NAME || !INTEGRAL_TYPE_P (TREE_TYPE (exp)))) | |
1904 | return; | |
1905 | ||
1906 | /* Start with simply saying "EXP != 0" and then look at the code of EXP | |
1907 | and see if we can refine the range. Some of the cases below may not | |
1908 | happen, but it doesn't seem worth worrying about this. We "continue" | |
1909 | the outer loop when we've changed something; otherwise we "break" | |
1910 | the switch, which will "break" the while. */ | |
1911 | low = exp ? build_int_cst (TREE_TYPE (exp), 0) : boolean_false_node; | |
1912 | high = low; | |
1913 | in_p = 0; | |
1914 | strict_overflow_p = false; | |
1915 | is_bool = false; | |
1916 | if (exp == NULL_TREE) | |
1917 | is_bool = true; | |
1918 | else if (TYPE_PRECISION (TREE_TYPE (exp)) == 1) | |
1919 | { | |
1920 | if (TYPE_UNSIGNED (TREE_TYPE (exp))) | |
1921 | is_bool = true; | |
1922 | else | |
1923 | return; | |
1924 | } | |
1925 | else if (TREE_CODE (TREE_TYPE (exp)) == BOOLEAN_TYPE) | |
1926 | is_bool = true; | |
1927 | ||
1928 | while (1) | |
1929 | { | |
1930 | enum tree_code code; | |
1931 | tree arg0, arg1, exp_type; | |
1932 | tree nexp; | |
1933 | location_t loc; | |
1934 | ||
1935 | if (exp != NULL_TREE) | |
1936 | { | |
1937 | if (TREE_CODE (exp) != SSA_NAME | |
1938 | || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp)) | |
1939 | break; | |
1940 | ||
1941 | stmt = SSA_NAME_DEF_STMT (exp); | |
1942 | if (!is_gimple_assign (stmt)) | |
1943 | break; | |
1944 | ||
1945 | code = gimple_assign_rhs_code (stmt); | |
1946 | arg0 = gimple_assign_rhs1 (stmt); | |
1947 | arg1 = gimple_assign_rhs2 (stmt); | |
1948 | exp_type = TREE_TYPE (exp); | |
1949 | } | |
1950 | else | |
1951 | { | |
1952 | code = gimple_cond_code (stmt); | |
1953 | arg0 = gimple_cond_lhs (stmt); | |
1954 | arg1 = gimple_cond_rhs (stmt); | |
1955 | exp_type = boolean_type_node; | |
1956 | } | |
1957 | ||
1958 | if (TREE_CODE (arg0) != SSA_NAME) | |
1959 | break; | |
1960 | loc = gimple_location (stmt); | |
1961 | switch (code) | |
1962 | { | |
1963 | case BIT_NOT_EXPR: | |
1964 | if (TREE_CODE (TREE_TYPE (exp)) == BOOLEAN_TYPE | |
1965 | /* Ensure the range is either +[-,0], +[0,0], | |
1966 | -[-,0], -[0,0] or +[1,-], +[1,1], -[1,-] or | |
1967 | -[1,1]. If it is e.g. +[-,-] or -[-,-] | |
1968 | or similar expression of unconditional true or | |
1969 | false, it should not be negated. */ | |
1970 | && ((high && integer_zerop (high)) | |
1971 | || (low && integer_onep (low)))) | |
1972 | { | |
1973 | in_p = !in_p; | |
1974 | exp = arg0; | |
1975 | continue; | |
1976 | } | |
1977 | break; | |
1978 | case SSA_NAME: | |
1979 | exp = arg0; | |
1980 | continue; | |
1981 | CASE_CONVERT: | |
1982 | if (is_bool) | |
1983 | goto do_default; | |
1984 | if (TYPE_PRECISION (TREE_TYPE (arg0)) == 1) | |
1985 | { | |
1986 | if (TYPE_UNSIGNED (TREE_TYPE (arg0))) | |
1987 | is_bool = true; | |
1988 | else | |
1989 | return; | |
1990 | } | |
1991 | else if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE) | |
1992 | is_bool = true; | |
1993 | goto do_default; | |
1994 | case EQ_EXPR: | |
1995 | case NE_EXPR: | |
1996 | case LT_EXPR: | |
1997 | case LE_EXPR: | |
1998 | case GE_EXPR: | |
1999 | case GT_EXPR: | |
2000 | is_bool = true; | |
2001 | /* FALLTHRU */ | |
2002 | default: | |
2003 | if (!is_bool) | |
2004 | return; | |
2005 | do_default: | |
2006 | nexp = make_range_step (loc, code, arg0, arg1, exp_type, | |
2007 | &low, &high, &in_p, | |
2008 | &strict_overflow_p); | |
2009 | if (nexp != NULL_TREE) | |
2010 | { | |
2011 | exp = nexp; | |
2012 | gcc_assert (TREE_CODE (exp) == SSA_NAME); | |
2013 | continue; | |
2014 | } | |
2015 | break; | |
2016 | } | |
2017 | break; | |
2018 | } | |
2019 | if (is_bool) | |
2020 | { | |
2021 | r->exp = exp; | |
2022 | r->in_p = in_p; | |
2023 | r->low = low; | |
2024 | r->high = high; | |
2025 | r->strict_overflow_p = strict_overflow_p; | |
2026 | } | |
2027 | } | |
2028 | ||
2029 | /* Comparison function for qsort. Sort entries | |
2030 | without SSA_NAME exp first, then with SSA_NAMEs sorted | |
2031 | by increasing SSA_NAME_VERSION, and for the same SSA_NAMEs | |
2032 | by increasing ->low and if ->low is the same, by increasing | |
2033 | ->high. ->low == NULL_TREE means minimum, ->high == NULL_TREE | |
2034 | maximum. */ | |
2035 | ||
2036 | static int | |
2037 | range_entry_cmp (const void *a, const void *b) | |
2038 | { | |
2039 | const struct range_entry *p = (const struct range_entry *) a; | |
2040 | const struct range_entry *q = (const struct range_entry *) b; | |
2041 | ||
2042 | if (p->exp != NULL_TREE && TREE_CODE (p->exp) == SSA_NAME) | |
2043 | { | |
2044 | if (q->exp != NULL_TREE && TREE_CODE (q->exp) == SSA_NAME) | |
2045 | { | |
2046 | /* Group range_entries for the same SSA_NAME together. */ | |
2047 | if (SSA_NAME_VERSION (p->exp) < SSA_NAME_VERSION (q->exp)) | |
2048 | return -1; | |
2049 | else if (SSA_NAME_VERSION (p->exp) > SSA_NAME_VERSION (q->exp)) | |
2050 | return 1; | |
2051 | /* If ->low is different, NULL low goes first, then by | |
2052 | ascending low. */ | |
2053 | if (p->low != NULL_TREE) | |
2054 | { | |
2055 | if (q->low != NULL_TREE) | |
2056 | { | |
2057 | tree tem = fold_binary (LT_EXPR, boolean_type_node, | |
2058 | p->low, q->low); | |
2059 | if (tem && integer_onep (tem)) | |
2060 | return -1; | |
2061 | tem = fold_binary (GT_EXPR, boolean_type_node, | |
2062 | p->low, q->low); | |
2063 | if (tem && integer_onep (tem)) | |
2064 | return 1; | |
2065 | } | |
2066 | else | |
2067 | return 1; | |
2068 | } | |
2069 | else if (q->low != NULL_TREE) | |
2070 | return -1; | |
2071 | /* If ->high is different, NULL high goes last, before that by | |
2072 | ascending high. */ | |
2073 | if (p->high != NULL_TREE) | |
2074 | { | |
2075 | if (q->high != NULL_TREE) | |
2076 | { | |
2077 | tree tem = fold_binary (LT_EXPR, boolean_type_node, | |
2078 | p->high, q->high); | |
2079 | if (tem && integer_onep (tem)) | |
2080 | return -1; | |
2081 | tem = fold_binary (GT_EXPR, boolean_type_node, | |
2082 | p->high, q->high); | |
2083 | if (tem && integer_onep (tem)) | |
2084 | return 1; | |
2085 | } | |
2086 | else | |
2087 | return -1; | |
2088 | } | |
2089 | else if (q->high != NULL_TREE) | |
2090 | return 1; | |
2091 | /* If both ranges are the same, sort below by ascending idx. */ | |
2092 | } | |
2093 | else | |
2094 | return 1; | |
2095 | } | |
2096 | else if (q->exp != NULL_TREE && TREE_CODE (q->exp) == SSA_NAME) | |
2097 | return -1; | |
2098 | ||
2099 | if (p->idx < q->idx) | |
2100 | return -1; | |
2101 | else | |
2102 | { | |
2103 | gcc_checking_assert (p->idx > q->idx); | |
2104 | return 1; | |
2105 | } | |
2106 | } | |
2107 | ||
2108 | /* Helper routine of optimize_range_test. | |
2109 | [EXP, IN_P, LOW, HIGH, STRICT_OVERFLOW_P] is a merged range for | |
2110 | RANGE and OTHERRANGE through OTHERRANGE + COUNT - 1 ranges, | |
2111 | OPCODE and OPS are arguments of optimize_range_tests. If OTHERRANGE | |
2112 | is NULL, OTHERRANGEP should not be and then OTHERRANGEP points to | |
2113 | an array of COUNT pointers to other ranges. Return | |
2114 | true if the range merge has been successful. | |
2115 | If OPCODE is ERROR_MARK, this is called from within | |
2116 | maybe_optimize_range_tests and is performing inter-bb range optimization. | |
2117 | In that case, whether an op is BIT_AND_EXPR or BIT_IOR_EXPR is found in | |
2118 | oe->rank. */ | |
2119 | ||
2120 | static bool | |
2121 | update_range_test (struct range_entry *range, struct range_entry *otherrange, | |
2122 | struct range_entry **otherrangep, | |
2123 | unsigned int count, enum tree_code opcode, | |
2124 | vec<operand_entry_t> *ops, tree exp, gimple_seq seq, | |
2125 | bool in_p, tree low, tree high, bool strict_overflow_p) | |
2126 | { | |
2127 | operand_entry_t oe = (*ops)[range->idx]; | |
2128 | tree op = oe->op; | |
2129 | gimple stmt = op ? SSA_NAME_DEF_STMT (op) : | |
2130 | last_stmt (BASIC_BLOCK_FOR_FN (cfun, oe->id)); | |
2131 | location_t loc = gimple_location (stmt); | |
2132 | tree optype = op ? TREE_TYPE (op) : boolean_type_node; | |
2133 | tree tem = build_range_check (loc, optype, unshare_expr (exp), | |
2134 | in_p, low, high); | |
2135 | enum warn_strict_overflow_code wc = WARN_STRICT_OVERFLOW_COMPARISON; | |
2136 | gimple_stmt_iterator gsi; | |
2137 | unsigned int i; | |
2138 | ||
2139 | if (tem == NULL_TREE) | |
2140 | return false; | |
2141 | ||
2142 | if (strict_overflow_p && issue_strict_overflow_warning (wc)) | |
2143 | warning_at (loc, OPT_Wstrict_overflow, | |
2144 | "assuming signed overflow does not occur " | |
2145 | "when simplifying range test"); | |
2146 | ||
2147 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2148 | { | |
2149 | struct range_entry *r; | |
2150 | fprintf (dump_file, "Optimizing range tests "); | |
2151 | print_generic_expr (dump_file, range->exp, 0); | |
2152 | fprintf (dump_file, " %c[", range->in_p ? '+' : '-'); | |
2153 | print_generic_expr (dump_file, range->low, 0); | |
2154 | fprintf (dump_file, ", "); | |
2155 | print_generic_expr (dump_file, range->high, 0); | |
2156 | fprintf (dump_file, "]"); | |
2157 | for (i = 0; i < count; i++) | |
2158 | { | |
2159 | if (otherrange) | |
2160 | r = otherrange + i; | |
2161 | else | |
2162 | r = otherrangep[i]; | |
2163 | fprintf (dump_file, " and %c[", r->in_p ? '+' : '-'); | |
2164 | print_generic_expr (dump_file, r->low, 0); | |
2165 | fprintf (dump_file, ", "); | |
2166 | print_generic_expr (dump_file, r->high, 0); | |
2167 | fprintf (dump_file, "]"); | |
2168 | } | |
2169 | fprintf (dump_file, "\n into "); | |
2170 | print_generic_expr (dump_file, tem, 0); | |
2171 | fprintf (dump_file, "\n"); | |
2172 | } | |
2173 | ||
2174 | if (opcode == BIT_IOR_EXPR | |
2175 | || (opcode == ERROR_MARK && oe->rank == BIT_IOR_EXPR)) | |
2176 | tem = invert_truthvalue_loc (loc, tem); | |
2177 | ||
2178 | tem = fold_convert_loc (loc, optype, tem); | |
2179 | gsi = gsi_for_stmt (stmt); | |
f4d9d362 | 2180 | unsigned int uid = gimple_uid (stmt); |
dda118e3 JM |
2181 | /* In rare cases range->exp can be equal to lhs of stmt. |
2182 | In that case we have to insert after the stmt rather then before | |
f4d9d362 JM |
2183 | it. If stmt is a PHI, insert it at the start of the basic block. */ |
2184 | if (op != range->exp) | |
2185 | { | |
2186 | gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT); | |
2187 | tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, true, | |
2188 | GSI_SAME_STMT); | |
2189 | gsi_prev (&gsi); | |
2190 | } | |
2191 | else if (gimple_code (stmt) != GIMPLE_PHI) | |
dda118e3 JM |
2192 | { |
2193 | gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING); | |
2194 | tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, false, | |
2195 | GSI_CONTINUE_LINKING); | |
2196 | } | |
2197 | else | |
2198 | { | |
f4d9d362 JM |
2199 | gsi = gsi_after_labels (gimple_bb (stmt)); |
2200 | if (!gsi_end_p (gsi)) | |
2201 | uid = gimple_uid (gsi_stmt (gsi)); | |
2202 | else | |
2203 | { | |
2204 | gsi = gsi_start_bb (gimple_bb (stmt)); | |
2205 | uid = 1; | |
2206 | while (!gsi_end_p (gsi)) | |
2207 | { | |
2208 | uid = gimple_uid (gsi_stmt (gsi)); | |
2209 | gsi_next (&gsi); | |
2210 | } | |
2211 | } | |
dda118e3 JM |
2212 | gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT); |
2213 | tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, true, | |
2214 | GSI_SAME_STMT); | |
f4d9d362 JM |
2215 | if (gsi_end_p (gsi)) |
2216 | gsi = gsi_last_bb (gimple_bb (stmt)); | |
2217 | else | |
2218 | gsi_prev (&gsi); | |
dda118e3 JM |
2219 | } |
2220 | for (; !gsi_end_p (gsi); gsi_prev (&gsi)) | |
2221 | if (gimple_uid (gsi_stmt (gsi))) | |
2222 | break; | |
2223 | else | |
f4d9d362 | 2224 | gimple_set_uid (gsi_stmt (gsi), uid); |
dda118e3 JM |
2225 | |
2226 | oe->op = tem; | |
2227 | range->exp = exp; | |
2228 | range->low = low; | |
2229 | range->high = high; | |
2230 | range->in_p = in_p; | |
2231 | range->strict_overflow_p = false; | |
2232 | ||
2233 | for (i = 0; i < count; i++) | |
2234 | { | |
2235 | if (otherrange) | |
2236 | range = otherrange + i; | |
2237 | else | |
2238 | range = otherrangep[i]; | |
2239 | oe = (*ops)[range->idx]; | |
2240 | /* Now change all the other range test immediate uses, so that | |
2241 | those tests will be optimized away. */ | |
2242 | if (opcode == ERROR_MARK) | |
2243 | { | |
2244 | if (oe->op) | |
2245 | oe->op = build_int_cst (TREE_TYPE (oe->op), | |
2246 | oe->rank == BIT_IOR_EXPR ? 0 : 1); | |
2247 | else | |
2248 | oe->op = (oe->rank == BIT_IOR_EXPR | |
2249 | ? boolean_false_node : boolean_true_node); | |
2250 | } | |
2251 | else | |
2252 | oe->op = error_mark_node; | |
2253 | range->exp = NULL_TREE; | |
2254 | } | |
2255 | return true; | |
2256 | } | |
2257 | ||
2258 | /* Optimize X == CST1 || X == CST2 | |
2259 | if popcount (CST1 ^ CST2) == 1 into | |
2260 | (X & ~(CST1 ^ CST2)) == (CST1 & ~(CST1 ^ CST2)). | |
2261 | Similarly for ranges. E.g. | |
2262 | X != 2 && X != 3 && X != 10 && X != 11 | |
2263 | will be transformed by the previous optimization into | |
2264 | !((X - 2U) <= 1U || (X - 10U) <= 1U) | |
2265 | and this loop can transform that into | |
2266 | !(((X & ~8) - 2U) <= 1U). */ | |
2267 | ||
2268 | static bool | |
2269 | optimize_range_tests_xor (enum tree_code opcode, tree type, | |
2270 | tree lowi, tree lowj, tree highi, tree highj, | |
2271 | vec<operand_entry_t> *ops, | |
2272 | struct range_entry *rangei, | |
2273 | struct range_entry *rangej) | |
2274 | { | |
2275 | tree lowxor, highxor, tem, exp; | |
2276 | /* Check lowi ^ lowj == highi ^ highj and | |
2277 | popcount (lowi ^ lowj) == 1. */ | |
2278 | lowxor = fold_binary (BIT_XOR_EXPR, type, lowi, lowj); | |
2279 | if (lowxor == NULL_TREE || TREE_CODE (lowxor) != INTEGER_CST) | |
2280 | return false; | |
2281 | if (!integer_pow2p (lowxor)) | |
2282 | return false; | |
2283 | highxor = fold_binary (BIT_XOR_EXPR, type, highi, highj); | |
2284 | if (!tree_int_cst_equal (lowxor, highxor)) | |
2285 | return false; | |
2286 | ||
2287 | tem = fold_build1 (BIT_NOT_EXPR, type, lowxor); | |
2288 | exp = fold_build2 (BIT_AND_EXPR, type, rangei->exp, tem); | |
2289 | lowj = fold_build2 (BIT_AND_EXPR, type, lowi, tem); | |
2290 | highj = fold_build2 (BIT_AND_EXPR, type, highi, tem); | |
2291 | if (update_range_test (rangei, rangej, NULL, 1, opcode, ops, exp, | |
2292 | NULL, rangei->in_p, lowj, highj, | |
2293 | rangei->strict_overflow_p | |
2294 | || rangej->strict_overflow_p)) | |
2295 | return true; | |
2296 | return false; | |
2297 | } | |
2298 | ||
2299 | /* Optimize X == CST1 || X == CST2 | |
2300 | if popcount (CST2 - CST1) == 1 into | |
2301 | ((X - CST1) & ~(CST2 - CST1)) == 0. | |
2302 | Similarly for ranges. E.g. | |
2303 | X == 43 || X == 76 || X == 44 || X == 78 || X == 77 || X == 46 | |
2304 | || X == 75 || X == 45 | |
2305 | will be transformed by the previous optimization into | |
2306 | (X - 43U) <= 3U || (X - 75U) <= 3U | |
2307 | and this loop can transform that into | |
2308 | ((X - 43U) & ~(75U - 43U)) <= 3U. */ | |
2309 | static bool | |
2310 | optimize_range_tests_diff (enum tree_code opcode, tree type, | |
2311 | tree lowi, tree lowj, tree highi, tree highj, | |
2312 | vec<operand_entry_t> *ops, | |
2313 | struct range_entry *rangei, | |
2314 | struct range_entry *rangej) | |
2315 | { | |
2316 | tree tem1, tem2, mask; | |
2317 | /* Check highi - lowi == highj - lowj. */ | |
2318 | tem1 = fold_binary (MINUS_EXPR, type, highi, lowi); | |
2319 | if (tem1 == NULL_TREE || TREE_CODE (tem1) != INTEGER_CST) | |
2320 | return false; | |
2321 | tem2 = fold_binary (MINUS_EXPR, type, highj, lowj); | |
2322 | if (!tree_int_cst_equal (tem1, tem2)) | |
2323 | return false; | |
2324 | /* Check popcount (lowj - lowi) == 1. */ | |
2325 | tem1 = fold_binary (MINUS_EXPR, type, lowj, lowi); | |
2326 | if (tem1 == NULL_TREE || TREE_CODE (tem1) != INTEGER_CST) | |
2327 | return false; | |
2328 | if (!integer_pow2p (tem1)) | |
2329 | return false; | |
2330 | ||
2331 | type = unsigned_type_for (type); | |
2332 | tem1 = fold_convert (type, tem1); | |
2333 | tem2 = fold_convert (type, tem2); | |
2334 | lowi = fold_convert (type, lowi); | |
2335 | mask = fold_build1 (BIT_NOT_EXPR, type, tem1); | |
2336 | tem1 = fold_binary (MINUS_EXPR, type, | |
2337 | fold_convert (type, rangei->exp), lowi); | |
2338 | tem1 = fold_build2 (BIT_AND_EXPR, type, tem1, mask); | |
2339 | lowj = build_int_cst (type, 0); | |
2340 | if (update_range_test (rangei, rangej, NULL, 1, opcode, ops, tem1, | |
2341 | NULL, rangei->in_p, lowj, tem2, | |
2342 | rangei->strict_overflow_p | |
2343 | || rangej->strict_overflow_p)) | |
2344 | return true; | |
2345 | return false; | |
2346 | } | |
2347 | ||
2348 | /* It does some common checks for function optimize_range_tests_xor and | |
2349 | optimize_range_tests_diff. | |
2350 | If OPTIMIZE_XOR is TRUE, it calls optimize_range_tests_xor. | |
2351 | Else it calls optimize_range_tests_diff. */ | |
2352 | ||
2353 | static bool | |
2354 | optimize_range_tests_1 (enum tree_code opcode, int first, int length, | |
2355 | bool optimize_xor, vec<operand_entry_t> *ops, | |
2356 | struct range_entry *ranges) | |
2357 | { | |
2358 | int i, j; | |
2359 | bool any_changes = false; | |
2360 | for (i = first; i < length; i++) | |
2361 | { | |
2362 | tree lowi, highi, lowj, highj, type, tem; | |
2363 | ||
2364 | if (ranges[i].exp == NULL_TREE || ranges[i].in_p) | |
2365 | continue; | |
2366 | type = TREE_TYPE (ranges[i].exp); | |
2367 | if (!INTEGRAL_TYPE_P (type)) | |
2368 | continue; | |
2369 | lowi = ranges[i].low; | |
2370 | if (lowi == NULL_TREE) | |
2371 | lowi = TYPE_MIN_VALUE (type); | |
2372 | highi = ranges[i].high; | |
2373 | if (highi == NULL_TREE) | |
2374 | continue; | |
2375 | for (j = i + 1; j < length && j < i + 64; j++) | |
2376 | { | |
2377 | bool changes; | |
2378 | if (ranges[i].exp != ranges[j].exp || ranges[j].in_p) | |
2379 | continue; | |
2380 | lowj = ranges[j].low; | |
2381 | if (lowj == NULL_TREE) | |
2382 | continue; | |
2383 | highj = ranges[j].high; | |
2384 | if (highj == NULL_TREE) | |
2385 | highj = TYPE_MAX_VALUE (type); | |
2386 | /* Check lowj > highi. */ | |
2387 | tem = fold_binary (GT_EXPR, boolean_type_node, | |
2388 | lowj, highi); | |
2389 | if (tem == NULL_TREE || !integer_onep (tem)) | |
2390 | continue; | |
2391 | if (optimize_xor) | |
2392 | changes = optimize_range_tests_xor (opcode, type, lowi, lowj, | |
2393 | highi, highj, ops, | |
2394 | ranges + i, ranges + j); | |
2395 | else | |
2396 | changes = optimize_range_tests_diff (opcode, type, lowi, lowj, | |
2397 | highi, highj, ops, | |
2398 | ranges + i, ranges + j); | |
2399 | if (changes) | |
2400 | { | |
2401 | any_changes = true; | |
2402 | break; | |
2403 | } | |
2404 | } | |
2405 | } | |
2406 | return any_changes; | |
2407 | } | |
2408 | ||
2409 | /* Helper function of optimize_range_tests_to_bit_test. Handle a single | |
2410 | range, EXP, LOW, HIGH, compute bit mask of bits to test and return | |
2411 | EXP on success, NULL otherwise. */ | |
2412 | ||
2413 | static tree | |
2414 | extract_bit_test_mask (tree exp, int prec, tree totallow, tree low, tree high, | |
2415 | wide_int *mask, tree *totallowp) | |
2416 | { | |
2417 | tree tem = int_const_binop (MINUS_EXPR, high, low); | |
2418 | if (tem == NULL_TREE | |
2419 | || TREE_CODE (tem) != INTEGER_CST | |
2420 | || TREE_OVERFLOW (tem) | |
2421 | || tree_int_cst_sgn (tem) == -1 | |
2422 | || compare_tree_int (tem, prec) != -1) | |
2423 | return NULL_TREE; | |
2424 | ||
2425 | unsigned HOST_WIDE_INT max = tree_to_uhwi (tem) + 1; | |
2426 | *mask = wi::shifted_mask (0, max, false, prec); | |
2427 | if (TREE_CODE (exp) == BIT_AND_EXPR | |
2428 | && TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST) | |
2429 | { | |
2430 | widest_int msk = wi::to_widest (TREE_OPERAND (exp, 1)); | |
2431 | msk = wi::zext (~msk, TYPE_PRECISION (TREE_TYPE (exp))); | |
2432 | if (wi::popcount (msk) == 1 | |
2433 | && wi::ltu_p (msk, prec - max)) | |
2434 | { | |
2435 | *mask |= wi::shifted_mask (msk.to_uhwi (), max, false, prec); | |
2436 | max += msk.to_uhwi (); | |
2437 | exp = TREE_OPERAND (exp, 0); | |
2438 | if (integer_zerop (low) | |
2439 | && TREE_CODE (exp) == PLUS_EXPR | |
2440 | && TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST) | |
2441 | { | |
38c0c85b JM |
2442 | tree ret = TREE_OPERAND (exp, 0); |
2443 | STRIP_NOPS (ret); | |
dda118e3 JM |
2444 | widest_int bias |
2445 | = wi::neg (wi::sext (wi::to_widest (TREE_OPERAND (exp, 1)), | |
2446 | TYPE_PRECISION (TREE_TYPE (low)))); | |
38c0c85b | 2447 | tree tbias = wide_int_to_tree (TREE_TYPE (ret), bias); |
dda118e3 JM |
2448 | if (totallowp) |
2449 | { | |
2450 | *totallowp = tbias; | |
38c0c85b | 2451 | return ret; |
dda118e3 JM |
2452 | } |
2453 | else if (!tree_int_cst_lt (totallow, tbias)) | |
2454 | return NULL_TREE; | |
38c0c85b | 2455 | bias = wi::to_widest (tbias); |
dda118e3 JM |
2456 | bias -= wi::to_widest (totallow); |
2457 | if (wi::ges_p (bias, 0) && wi::lts_p (bias, prec - max)) | |
2458 | { | |
2459 | *mask = wi::lshift (*mask, bias); | |
38c0c85b | 2460 | return ret; |
dda118e3 JM |
2461 | } |
2462 | } | |
2463 | } | |
2464 | } | |
2465 | if (totallowp) | |
2466 | return exp; | |
2467 | if (!tree_int_cst_lt (totallow, low)) | |
2468 | return exp; | |
2469 | tem = int_const_binop (MINUS_EXPR, low, totallow); | |
2470 | if (tem == NULL_TREE | |
2471 | || TREE_CODE (tem) != INTEGER_CST | |
2472 | || TREE_OVERFLOW (tem) | |
2473 | || compare_tree_int (tem, prec - max) == 1) | |
2474 | return NULL_TREE; | |
2475 | ||
2476 | *mask = wi::lshift (*mask, wi::to_widest (tem)); | |
2477 | return exp; | |
2478 | } | |
2479 | ||
2480 | /* Attempt to optimize small range tests using bit test. | |
2481 | E.g. | |
2482 | X != 43 && X != 76 && X != 44 && X != 78 && X != 49 | |
2483 | && X != 77 && X != 46 && X != 75 && X != 45 && X != 82 | |
2484 | has been by earlier optimizations optimized into: | |
2485 | ((X - 43U) & ~32U) > 3U && X != 49 && X != 82 | |
2486 | As all the 43 through 82 range is less than 64 numbers, | |
2487 | for 64-bit word targets optimize that into: | |
2488 | (X - 43U) > 40U && ((1 << (X - 43U)) & 0x8F0000004FULL) == 0 */ | |
2489 | ||
2490 | static bool | |
2491 | optimize_range_tests_to_bit_test (enum tree_code opcode, int first, int length, | |
2492 | vec<operand_entry_t> *ops, | |
2493 | struct range_entry *ranges) | |
2494 | { | |
2495 | int i, j; | |
2496 | bool any_changes = false; | |
2497 | int prec = GET_MODE_BITSIZE (word_mode); | |
2498 | auto_vec<struct range_entry *, 64> candidates; | |
2499 | ||
2500 | for (i = first; i < length - 2; i++) | |
2501 | { | |
2502 | tree lowi, highi, lowj, highj, type; | |
2503 | ||
2504 | if (ranges[i].exp == NULL_TREE || ranges[i].in_p) | |
2505 | continue; | |
2506 | type = TREE_TYPE (ranges[i].exp); | |
2507 | if (!INTEGRAL_TYPE_P (type)) | |
2508 | continue; | |
2509 | lowi = ranges[i].low; | |
2510 | if (lowi == NULL_TREE) | |
2511 | lowi = TYPE_MIN_VALUE (type); | |
2512 | highi = ranges[i].high; | |
2513 | if (highi == NULL_TREE) | |
2514 | continue; | |
2515 | wide_int mask; | |
2516 | tree exp = extract_bit_test_mask (ranges[i].exp, prec, lowi, lowi, | |
2517 | highi, &mask, &lowi); | |
2518 | if (exp == NULL_TREE) | |
2519 | continue; | |
2520 | bool strict_overflow_p = ranges[i].strict_overflow_p; | |
2521 | candidates.truncate (0); | |
2522 | int end = MIN (i + 64, length); | |
2523 | for (j = i + 1; j < end; j++) | |
2524 | { | |
2525 | tree exp2; | |
2526 | if (ranges[j].exp == NULL_TREE || ranges[j].in_p) | |
2527 | continue; | |
2528 | if (ranges[j].exp == exp) | |
2529 | ; | |
2530 | else if (TREE_CODE (ranges[j].exp) == BIT_AND_EXPR) | |
2531 | { | |
2532 | exp2 = TREE_OPERAND (ranges[j].exp, 0); | |
2533 | if (exp2 == exp) | |
2534 | ; | |
2535 | else if (TREE_CODE (exp2) == PLUS_EXPR) | |
2536 | { | |
2537 | exp2 = TREE_OPERAND (exp2, 0); | |
2538 | STRIP_NOPS (exp2); | |
2539 | if (exp2 != exp) | |
2540 | continue; | |
2541 | } | |
2542 | else | |
2543 | continue; | |
2544 | } | |
2545 | else | |
2546 | continue; | |
2547 | lowj = ranges[j].low; | |
2548 | if (lowj == NULL_TREE) | |
2549 | continue; | |
2550 | highj = ranges[j].high; | |
2551 | if (highj == NULL_TREE) | |
2552 | highj = TYPE_MAX_VALUE (type); | |
2553 | wide_int mask2; | |
2554 | exp2 = extract_bit_test_mask (ranges[j].exp, prec, lowi, lowj, | |
2555 | highj, &mask2, NULL); | |
2556 | if (exp2 != exp) | |
2557 | continue; | |
2558 | mask |= mask2; | |
2559 | strict_overflow_p |= ranges[j].strict_overflow_p; | |
2560 | candidates.safe_push (&ranges[j]); | |
2561 | } | |
2562 | ||
2563 | /* If we need otherwise 3 or more comparisons, use a bit test. */ | |
2564 | if (candidates.length () >= 2) | |
2565 | { | |
2566 | tree high = wide_int_to_tree (TREE_TYPE (lowi), | |
2567 | wi::to_widest (lowi) | |
2568 | + prec - 1 - wi::clz (mask)); | |
2569 | operand_entry_t oe = (*ops)[ranges[i].idx]; | |
2570 | tree op = oe->op; | |
2571 | gimple stmt = op ? SSA_NAME_DEF_STMT (op) | |
2572 | : last_stmt (BASIC_BLOCK_FOR_FN (cfun, oe->id)); | |
2573 | location_t loc = gimple_location (stmt); | |
2574 | tree optype = op ? TREE_TYPE (op) : boolean_type_node; | |
2575 | ||
2576 | /* See if it isn't cheaper to pretend the minimum value of the | |
2577 | range is 0, if maximum value is small enough. | |
2578 | We can avoid then subtraction of the minimum value, but the | |
2579 | mask constant could be perhaps more expensive. */ | |
2580 | if (compare_tree_int (lowi, 0) > 0 | |
2581 | && compare_tree_int (high, prec) < 0) | |
2582 | { | |
2583 | int cost_diff; | |
2584 | HOST_WIDE_INT m = tree_to_uhwi (lowi); | |
2585 | rtx reg = gen_raw_REG (word_mode, 10000); | |
2586 | bool speed_p = optimize_bb_for_speed_p (gimple_bb (stmt)); | |
2587 | cost_diff = set_rtx_cost (gen_rtx_PLUS (word_mode, reg, | |
2588 | GEN_INT (-m)), speed_p); | |
2589 | rtx r = immed_wide_int_const (mask, word_mode); | |
2590 | cost_diff += set_src_cost (gen_rtx_AND (word_mode, reg, r), | |
2591 | speed_p); | |
2592 | r = immed_wide_int_const (wi::lshift (mask, m), word_mode); | |
2593 | cost_diff -= set_src_cost (gen_rtx_AND (word_mode, reg, r), | |
2594 | speed_p); | |
2595 | if (cost_diff > 0) | |
2596 | { | |
2597 | mask = wi::lshift (mask, m); | |
2598 | lowi = build_zero_cst (TREE_TYPE (lowi)); | |
2599 | } | |
2600 | } | |
2601 | ||
2602 | tree tem = build_range_check (loc, optype, unshare_expr (exp), | |
2603 | false, lowi, high); | |
2604 | if (tem == NULL_TREE || is_gimple_val (tem)) | |
2605 | continue; | |
2606 | tree etype = unsigned_type_for (TREE_TYPE (exp)); | |
2607 | exp = fold_build2_loc (loc, MINUS_EXPR, etype, | |
2608 | fold_convert_loc (loc, etype, exp), | |
2609 | fold_convert_loc (loc, etype, lowi)); | |
2610 | exp = fold_convert_loc (loc, integer_type_node, exp); | |
2611 | tree word_type = lang_hooks.types.type_for_mode (word_mode, 1); | |
2612 | exp = fold_build2_loc (loc, LSHIFT_EXPR, word_type, | |
2613 | build_int_cst (word_type, 1), exp); | |
2614 | exp = fold_build2_loc (loc, BIT_AND_EXPR, word_type, exp, | |
2615 | wide_int_to_tree (word_type, mask)); | |
2616 | exp = fold_build2_loc (loc, EQ_EXPR, optype, exp, | |
2617 | build_zero_cst (word_type)); | |
2618 | if (is_gimple_val (exp)) | |
2619 | continue; | |
2620 | ||
2621 | /* The shift might have undefined behavior if TEM is true, | |
2622 | but reassociate_bb isn't prepared to have basic blocks | |
2623 | split when it is running. So, temporarily emit a code | |
2624 | with BIT_IOR_EXPR instead of &&, and fix it up in | |
2625 | branch_fixup. */ | |
2626 | gimple_seq seq; | |
2627 | tem = force_gimple_operand (tem, &seq, true, NULL_TREE); | |
2628 | gcc_assert (TREE_CODE (tem) == SSA_NAME); | |
2629 | gimple_set_visited (SSA_NAME_DEF_STMT (tem), true); | |
2630 | gimple_seq seq2; | |
2631 | exp = force_gimple_operand (exp, &seq2, true, NULL_TREE); | |
2632 | gimple_seq_add_seq_without_update (&seq, seq2); | |
2633 | gcc_assert (TREE_CODE (exp) == SSA_NAME); | |
2634 | gimple_set_visited (SSA_NAME_DEF_STMT (exp), true); | |
2635 | gimple g = gimple_build_assign (make_ssa_name (optype), | |
2636 | BIT_IOR_EXPR, tem, exp); | |
2637 | gimple_set_location (g, loc); | |
2638 | gimple_seq_add_stmt_without_update (&seq, g); | |
2639 | exp = gimple_assign_lhs (g); | |
2640 | tree val = build_zero_cst (optype); | |
2641 | if (update_range_test (&ranges[i], NULL, candidates.address (), | |
2642 | candidates.length (), opcode, ops, exp, | |
2643 | seq, false, val, val, strict_overflow_p)) | |
2644 | { | |
2645 | any_changes = true; | |
2646 | reassoc_branch_fixups.safe_push (tem); | |
2647 | } | |
2648 | else | |
2649 | gimple_seq_discard (seq); | |
2650 | } | |
2651 | } | |
2652 | return any_changes; | |
2653 | } | |
2654 | ||
2655 | /* Optimize range tests, similarly how fold_range_test optimizes | |
2656 | it on trees. The tree code for the binary | |
2657 | operation between all the operands is OPCODE. | |
2658 | If OPCODE is ERROR_MARK, optimize_range_tests is called from within | |
2659 | maybe_optimize_range_tests for inter-bb range optimization. | |
2660 | In that case if oe->op is NULL, oe->id is bb->index whose | |
2661 | GIMPLE_COND is && or ||ed into the test, and oe->rank says | |
2662 | the actual opcode. */ | |
2663 | ||
2664 | static bool | |
2665 | optimize_range_tests (enum tree_code opcode, | |
2666 | vec<operand_entry_t> *ops) | |
2667 | { | |
2668 | unsigned int length = ops->length (), i, j, first; | |
2669 | operand_entry_t oe; | |
2670 | struct range_entry *ranges; | |
2671 | bool any_changes = false; | |
2672 | ||
2673 | if (length == 1) | |
2674 | return false; | |
2675 | ||
2676 | ranges = XNEWVEC (struct range_entry, length); | |
2677 | for (i = 0; i < length; i++) | |
2678 | { | |
2679 | oe = (*ops)[i]; | |
2680 | ranges[i].idx = i; | |
2681 | init_range_entry (ranges + i, oe->op, | |
2682 | oe->op ? NULL : | |
2683 | last_stmt (BASIC_BLOCK_FOR_FN (cfun, oe->id))); | |
2684 | /* For | invert it now, we will invert it again before emitting | |
2685 | the optimized expression. */ | |
2686 | if (opcode == BIT_IOR_EXPR | |
2687 | || (opcode == ERROR_MARK && oe->rank == BIT_IOR_EXPR)) | |
2688 | ranges[i].in_p = !ranges[i].in_p; | |
2689 | } | |
2690 | ||
2691 | qsort (ranges, length, sizeof (*ranges), range_entry_cmp); | |
2692 | for (i = 0; i < length; i++) | |
2693 | if (ranges[i].exp != NULL_TREE && TREE_CODE (ranges[i].exp) == SSA_NAME) | |
2694 | break; | |
2695 | ||
2696 | /* Try to merge ranges. */ | |
2697 | for (first = i; i < length; i++) | |
2698 | { | |
2699 | tree low = ranges[i].low; | |
2700 | tree high = ranges[i].high; | |
2701 | int in_p = ranges[i].in_p; | |
2702 | bool strict_overflow_p = ranges[i].strict_overflow_p; | |
2703 | int update_fail_count = 0; | |
2704 | ||
2705 | for (j = i + 1; j < length; j++) | |
2706 | { | |
2707 | if (ranges[i].exp != ranges[j].exp) | |
2708 | break; | |
2709 | if (!merge_ranges (&in_p, &low, &high, in_p, low, high, | |
2710 | ranges[j].in_p, ranges[j].low, ranges[j].high)) | |
2711 | break; | |
2712 | strict_overflow_p |= ranges[j].strict_overflow_p; | |
2713 | } | |
2714 | ||
2715 | if (j == i + 1) | |
2716 | continue; | |
2717 | ||
2718 | if (update_range_test (ranges + i, ranges + i + 1, NULL, j - i - 1, | |
2719 | opcode, ops, ranges[i].exp, NULL, in_p, | |
2720 | low, high, strict_overflow_p)) | |
2721 | { | |
2722 | i = j - 1; | |
2723 | any_changes = true; | |
2724 | } | |
2725 | /* Avoid quadratic complexity if all merge_ranges calls would succeed, | |
2726 | while update_range_test would fail. */ | |
2727 | else if (update_fail_count == 64) | |
2728 | i = j - 1; | |
2729 | else | |
2730 | ++update_fail_count; | |
2731 | } | |
2732 | ||
2733 | any_changes |= optimize_range_tests_1 (opcode, first, length, true, | |
2734 | ops, ranges); | |
2735 | ||
2736 | if (BRANCH_COST (optimize_function_for_speed_p (cfun), false) >= 2) | |
2737 | any_changes |= optimize_range_tests_1 (opcode, first, length, false, | |
2738 | ops, ranges); | |
2739 | if (lshift_cheap_p (optimize_function_for_speed_p (cfun))) | |
2740 | any_changes |= optimize_range_tests_to_bit_test (opcode, first, length, | |
2741 | ops, ranges); | |
2742 | ||
2743 | if (any_changes && opcode != ERROR_MARK) | |
2744 | { | |
2745 | j = 0; | |
2746 | FOR_EACH_VEC_ELT (*ops, i, oe) | |
2747 | { | |
2748 | if (oe->op == error_mark_node) | |
2749 | continue; | |
2750 | else if (i != j) | |
2751 | (*ops)[j] = oe; | |
2752 | j++; | |
2753 | } | |
2754 | ops->truncate (j); | |
2755 | } | |
2756 | ||
2757 | XDELETEVEC (ranges); | |
2758 | return any_changes; | |
2759 | } | |
2760 | ||
2761 | /* Return true if STMT is a cast like: | |
2762 | <bb N>: | |
2763 | ... | |
2764 | _123 = (int) _234; | |
2765 | ||
2766 | <bb M>: | |
2767 | # _345 = PHI <_123(N), 1(...), 1(...)> | |
2768 | where _234 has bool type, _123 has single use and | |
2769 | bb N has a single successor M. This is commonly used in | |
2770 | the last block of a range test. */ | |
2771 | ||
2772 | static bool | |
2773 | final_range_test_p (gimple stmt) | |
2774 | { | |
2775 | basic_block bb, rhs_bb; | |
2776 | edge e; | |
2777 | tree lhs, rhs; | |
2778 | use_operand_p use_p; | |
2779 | gimple use_stmt; | |
2780 | ||
2781 | if (!gimple_assign_cast_p (stmt)) | |
2782 | return false; | |
2783 | bb = gimple_bb (stmt); | |
2784 | if (!single_succ_p (bb)) | |
2785 | return false; | |
2786 | e = single_succ_edge (bb); | |
2787 | if (e->flags & EDGE_COMPLEX) | |
2788 | return false; | |
2789 | ||
2790 | lhs = gimple_assign_lhs (stmt); | |
2791 | rhs = gimple_assign_rhs1 (stmt); | |
2792 | if (!INTEGRAL_TYPE_P (TREE_TYPE (lhs)) | |
2793 | || TREE_CODE (rhs) != SSA_NAME | |
2794 | || TREE_CODE (TREE_TYPE (rhs)) != BOOLEAN_TYPE) | |
2795 | return false; | |
2796 | ||
2797 | /* Test whether lhs is consumed only by a PHI in the only successor bb. */ | |
2798 | if (!single_imm_use (lhs, &use_p, &use_stmt)) | |
2799 | return false; | |
2800 | ||
2801 | if (gimple_code (use_stmt) != GIMPLE_PHI | |
2802 | || gimple_bb (use_stmt) != e->dest) | |
2803 | return false; | |
2804 | ||
2805 | /* And that the rhs is defined in the same loop. */ | |
2806 | rhs_bb = gimple_bb (SSA_NAME_DEF_STMT (rhs)); | |
2807 | if (rhs_bb == NULL | |
2808 | || !flow_bb_inside_loop_p (loop_containing_stmt (stmt), rhs_bb)) | |
2809 | return false; | |
2810 | ||
2811 | return true; | |
2812 | } | |
2813 | ||
2814 | /* Return true if BB is suitable basic block for inter-bb range test | |
2815 | optimization. If BACKWARD is true, BB should be the only predecessor | |
2816 | of TEST_BB, and *OTHER_BB is either NULL and filled by the routine, | |
2817 | or compared with to find a common basic block to which all conditions | |
2818 | branch to if true resp. false. If BACKWARD is false, TEST_BB should | |
2819 | be the only predecessor of BB. */ | |
2820 | ||
2821 | static bool | |
2822 | suitable_cond_bb (basic_block bb, basic_block test_bb, basic_block *other_bb, | |
2823 | bool backward) | |
2824 | { | |
2825 | edge_iterator ei, ei2; | |
2826 | edge e, e2; | |
2827 | gimple stmt; | |
2828 | gphi_iterator gsi; | |
2829 | bool other_edge_seen = false; | |
2830 | bool is_cond; | |
2831 | ||
2832 | if (test_bb == bb) | |
2833 | return false; | |
2834 | /* Check last stmt first. */ | |
2835 | stmt = last_stmt (bb); | |
2836 | if (stmt == NULL | |
2837 | || (gimple_code (stmt) != GIMPLE_COND | |
2838 | && (backward || !final_range_test_p (stmt))) | |
2839 | || gimple_visited_p (stmt) | |
2840 | || stmt_could_throw_p (stmt) | |
2841 | || *other_bb == bb) | |
2842 | return false; | |
2843 | is_cond = gimple_code (stmt) == GIMPLE_COND; | |
2844 | if (is_cond) | |
2845 | { | |
2846 | /* If last stmt is GIMPLE_COND, verify that one of the succ edges | |
2847 | goes to the next bb (if BACKWARD, it is TEST_BB), and the other | |
2848 | to *OTHER_BB (if not set yet, try to find it out). */ | |
2849 | if (EDGE_COUNT (bb->succs) != 2) | |
2850 | return false; | |
2851 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2852 | { | |
2853 | if (!(e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))) | |
2854 | return false; | |
2855 | if (e->dest == test_bb) | |
2856 | { | |
2857 | if (backward) | |
2858 | continue; | |
2859 | else | |
2860 | return false; | |
2861 | } | |
2862 | if (e->dest == bb) | |
2863 | return false; | |
2864 | if (*other_bb == NULL) | |
2865 | { | |
2866 | FOR_EACH_EDGE (e2, ei2, test_bb->succs) | |
2867 | if (!(e2->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))) | |
2868 | return false; | |
2869 | else if (e->dest == e2->dest) | |
2870 | *other_bb = e->dest; | |
2871 | if (*other_bb == NULL) | |
2872 | return false; | |
2873 | } | |
2874 | if (e->dest == *other_bb) | |
2875 | other_edge_seen = true; | |
2876 | else if (backward) | |
2877 | return false; | |
2878 | } | |
2879 | if (*other_bb == NULL || !other_edge_seen) | |
2880 | return false; | |
2881 | } | |
2882 | else if (single_succ (bb) != *other_bb) | |
2883 | return false; | |
2884 | ||
2885 | /* Now check all PHIs of *OTHER_BB. */ | |
2886 | e = find_edge (bb, *other_bb); | |
2887 | e2 = find_edge (test_bb, *other_bb); | |
2888 | for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2889 | { | |
2890 | gphi *phi = gsi.phi (); | |
2891 | /* If both BB and TEST_BB end with GIMPLE_COND, all PHI arguments | |
2892 | corresponding to BB and TEST_BB predecessor must be the same. */ | |
2893 | if (!operand_equal_p (gimple_phi_arg_def (phi, e->dest_idx), | |
2894 | gimple_phi_arg_def (phi, e2->dest_idx), 0)) | |
2895 | { | |
2896 | /* Otherwise, if one of the blocks doesn't end with GIMPLE_COND, | |
2897 | one of the PHIs should have the lhs of the last stmt in | |
2898 | that block as PHI arg and that PHI should have 0 or 1 | |
2899 | corresponding to it in all other range test basic blocks | |
2900 | considered. */ | |
2901 | if (!is_cond) | |
2902 | { | |
2903 | if (gimple_phi_arg_def (phi, e->dest_idx) | |
2904 | == gimple_assign_lhs (stmt) | |
2905 | && (integer_zerop (gimple_phi_arg_def (phi, e2->dest_idx)) | |
2906 | || integer_onep (gimple_phi_arg_def (phi, | |
2907 | e2->dest_idx)))) | |
2908 | continue; | |
2909 | } | |
2910 | else | |
2911 | { | |
2912 | gimple test_last = last_stmt (test_bb); | |
2913 | if (gimple_code (test_last) != GIMPLE_COND | |
2914 | && gimple_phi_arg_def (phi, e2->dest_idx) | |
2915 | == gimple_assign_lhs (test_last) | |
2916 | && (integer_zerop (gimple_phi_arg_def (phi, e->dest_idx)) | |
2917 | || integer_onep (gimple_phi_arg_def (phi, e->dest_idx)))) | |
2918 | continue; | |
2919 | } | |
2920 | ||
2921 | return false; | |
2922 | } | |
2923 | } | |
2924 | return true; | |
2925 | } | |
2926 | ||
2927 | /* Return true if BB doesn't have side-effects that would disallow | |
2928 | range test optimization, all SSA_NAMEs set in the bb are consumed | |
2929 | in the bb and there are no PHIs. */ | |
2930 | ||
2931 | static bool | |
2932 | no_side_effect_bb (basic_block bb) | |
2933 | { | |
2934 | gimple_stmt_iterator gsi; | |
2935 | gimple last; | |
2936 | ||
2937 | if (!gimple_seq_empty_p (phi_nodes (bb))) | |
2938 | return false; | |
2939 | last = last_stmt (bb); | |
2940 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2941 | { | |
2942 | gimple stmt = gsi_stmt (gsi); | |
2943 | tree lhs; | |
2944 | imm_use_iterator imm_iter; | |
2945 | use_operand_p use_p; | |
2946 | ||
2947 | if (is_gimple_debug (stmt)) | |
2948 | continue; | |
2949 | if (gimple_has_side_effects (stmt)) | |
2950 | return false; | |
2951 | if (stmt == last) | |
2952 | return true; | |
2953 | if (!is_gimple_assign (stmt)) | |
2954 | return false; | |
2955 | lhs = gimple_assign_lhs (stmt); | |
2956 | if (TREE_CODE (lhs) != SSA_NAME) | |
2957 | return false; | |
2958 | if (gimple_assign_rhs_could_trap_p (stmt)) | |
2959 | return false; | |
2960 | FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs) | |
2961 | { | |
2962 | gimple use_stmt = USE_STMT (use_p); | |
2963 | if (is_gimple_debug (use_stmt)) | |
2964 | continue; | |
2965 | if (gimple_bb (use_stmt) != bb) | |
2966 | return false; | |
2967 | } | |
2968 | } | |
2969 | return false; | |
2970 | } | |
2971 | ||
2972 | /* If VAR is set by CODE (BIT_{AND,IOR}_EXPR) which is reassociable, | |
2973 | return true and fill in *OPS recursively. */ | |
2974 | ||
2975 | static bool | |
2976 | get_ops (tree var, enum tree_code code, vec<operand_entry_t> *ops, | |
2977 | struct loop *loop) | |
2978 | { | |
2979 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
2980 | tree rhs[2]; | |
2981 | int i; | |
2982 | ||
2983 | if (!is_reassociable_op (stmt, code, loop)) | |
2984 | return false; | |
2985 | ||
2986 | rhs[0] = gimple_assign_rhs1 (stmt); | |
2987 | rhs[1] = gimple_assign_rhs2 (stmt); | |
2988 | gimple_set_visited (stmt, true); | |
2989 | for (i = 0; i < 2; i++) | |
2990 | if (TREE_CODE (rhs[i]) == SSA_NAME | |
2991 | && !get_ops (rhs[i], code, ops, loop) | |
2992 | && has_single_use (rhs[i])) | |
2993 | { | |
2994 | operand_entry_t oe = (operand_entry_t) pool_alloc (operand_entry_pool); | |
2995 | ||
2996 | oe->op = rhs[i]; | |
2997 | oe->rank = code; | |
2998 | oe->id = 0; | |
2999 | oe->count = 1; | |
3000 | ops->safe_push (oe); | |
3001 | } | |
3002 | return true; | |
3003 | } | |
3004 | ||
3005 | /* Find the ops that were added by get_ops starting from VAR, see if | |
3006 | they were changed during update_range_test and if yes, create new | |
3007 | stmts. */ | |
3008 | ||
3009 | static tree | |
3010 | update_ops (tree var, enum tree_code code, vec<operand_entry_t> ops, | |
3011 | unsigned int *pidx, struct loop *loop) | |
3012 | { | |
3013 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
3014 | tree rhs[4]; | |
3015 | int i; | |
3016 | ||
3017 | if (!is_reassociable_op (stmt, code, loop)) | |
3018 | return NULL; | |
3019 | ||
3020 | rhs[0] = gimple_assign_rhs1 (stmt); | |
3021 | rhs[1] = gimple_assign_rhs2 (stmt); | |
3022 | rhs[2] = rhs[0]; | |
3023 | rhs[3] = rhs[1]; | |
3024 | for (i = 0; i < 2; i++) | |
3025 | if (TREE_CODE (rhs[i]) == SSA_NAME) | |
3026 | { | |
3027 | rhs[2 + i] = update_ops (rhs[i], code, ops, pidx, loop); | |
3028 | if (rhs[2 + i] == NULL_TREE) | |
3029 | { | |
3030 | if (has_single_use (rhs[i])) | |
3031 | rhs[2 + i] = ops[(*pidx)++]->op; | |
3032 | else | |
3033 | rhs[2 + i] = rhs[i]; | |
3034 | } | |
3035 | } | |
3036 | if ((rhs[2] != rhs[0] || rhs[3] != rhs[1]) | |
3037 | && (rhs[2] != rhs[1] || rhs[3] != rhs[0])) | |
3038 | { | |
3039 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); | |
3040 | var = make_ssa_name (TREE_TYPE (var)); | |
3041 | gassign *g = gimple_build_assign (var, gimple_assign_rhs_code (stmt), | |
3042 | rhs[2], rhs[3]); | |
3043 | gimple_set_uid (g, gimple_uid (stmt)); | |
3044 | gimple_set_visited (g, true); | |
3045 | gsi_insert_before (&gsi, g, GSI_SAME_STMT); | |
3046 | } | |
3047 | return var; | |
3048 | } | |
3049 | ||
3050 | /* Structure to track the initial value passed to get_ops and | |
3051 | the range in the ops vector for each basic block. */ | |
3052 | ||
3053 | struct inter_bb_range_test_entry | |
3054 | { | |
3055 | tree op; | |
3056 | unsigned int first_idx, last_idx; | |
3057 | }; | |
3058 | ||
3059 | /* Inter-bb range test optimization. */ | |
3060 | ||
3061 | static void | |
3062 | maybe_optimize_range_tests (gimple stmt) | |
3063 | { | |
3064 | basic_block first_bb = gimple_bb (stmt); | |
3065 | basic_block last_bb = first_bb; | |
3066 | basic_block other_bb = NULL; | |
3067 | basic_block bb; | |
3068 | edge_iterator ei; | |
3069 | edge e; | |
3070 | auto_vec<operand_entry_t> ops; | |
3071 | auto_vec<inter_bb_range_test_entry> bbinfo; | |
3072 | bool any_changes = false; | |
3073 | ||
3074 | /* Consider only basic blocks that end with GIMPLE_COND or | |
3075 | a cast statement satisfying final_range_test_p. All | |
3076 | but the last bb in the first_bb .. last_bb range | |
3077 | should end with GIMPLE_COND. */ | |
3078 | if (gimple_code (stmt) == GIMPLE_COND) | |
3079 | { | |
3080 | if (EDGE_COUNT (first_bb->succs) != 2) | |
3081 | return; | |
3082 | } | |
3083 | else if (final_range_test_p (stmt)) | |
3084 | other_bb = single_succ (first_bb); | |
3085 | else | |
3086 | return; | |
3087 | ||
3088 | if (stmt_could_throw_p (stmt)) | |
3089 | return; | |
3090 | ||
3091 | /* As relative ordering of post-dominator sons isn't fixed, | |
3092 | maybe_optimize_range_tests can be called first on any | |
3093 | bb in the range we want to optimize. So, start searching | |
3094 | backwards, if first_bb can be set to a predecessor. */ | |
3095 | while (single_pred_p (first_bb)) | |
3096 | { | |
3097 | basic_block pred_bb = single_pred (first_bb); | |
3098 | if (!suitable_cond_bb (pred_bb, first_bb, &other_bb, true)) | |
3099 | break; | |
3100 | if (!no_side_effect_bb (first_bb)) | |
3101 | break; | |
3102 | first_bb = pred_bb; | |
3103 | } | |
3104 | /* If first_bb is last_bb, other_bb hasn't been computed yet. | |
3105 | Before starting forward search in last_bb successors, find | |
3106 | out the other_bb. */ | |
3107 | if (first_bb == last_bb) | |
3108 | { | |
3109 | other_bb = NULL; | |
3110 | /* As non-GIMPLE_COND last stmt always terminates the range, | |
3111 | if forward search didn't discover anything, just give up. */ | |
3112 | if (gimple_code (stmt) != GIMPLE_COND) | |
3113 | return; | |
3114 | /* Look at both successors. Either it ends with a GIMPLE_COND | |
3115 | and satisfies suitable_cond_bb, or ends with a cast and | |
3116 | other_bb is that cast's successor. */ | |
3117 | FOR_EACH_EDGE (e, ei, first_bb->succs) | |
3118 | if (!(e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)) | |
3119 | || e->dest == first_bb) | |
3120 | return; | |
3121 | else if (single_pred_p (e->dest)) | |
3122 | { | |
3123 | stmt = last_stmt (e->dest); | |
3124 | if (stmt | |
3125 | && gimple_code (stmt) == GIMPLE_COND | |
3126 | && EDGE_COUNT (e->dest->succs) == 2) | |
3127 | { | |
3128 | if (suitable_cond_bb (first_bb, e->dest, &other_bb, true)) | |
3129 | break; | |
3130 | else | |
3131 | other_bb = NULL; | |
3132 | } | |
3133 | else if (stmt | |
3134 | && final_range_test_p (stmt) | |
3135 | && find_edge (first_bb, single_succ (e->dest))) | |
3136 | { | |
3137 | other_bb = single_succ (e->dest); | |
3138 | if (other_bb == first_bb) | |
3139 | other_bb = NULL; | |
3140 | } | |
3141 | } | |
3142 | if (other_bb == NULL) | |
3143 | return; | |
3144 | } | |
3145 | /* Now do the forward search, moving last_bb to successor bbs | |
3146 | that aren't other_bb. */ | |
3147 | while (EDGE_COUNT (last_bb->succs) == 2) | |
3148 | { | |
3149 | FOR_EACH_EDGE (e, ei, last_bb->succs) | |
3150 | if (e->dest != other_bb) | |
3151 | break; | |
3152 | if (e == NULL) | |
3153 | break; | |
3154 | if (!single_pred_p (e->dest)) | |
3155 | break; | |
3156 | if (!suitable_cond_bb (e->dest, last_bb, &other_bb, false)) | |
3157 | break; | |
3158 | if (!no_side_effect_bb (e->dest)) | |
3159 | break; | |
3160 | last_bb = e->dest; | |
3161 | } | |
3162 | if (first_bb == last_bb) | |
3163 | return; | |
3164 | /* Here basic blocks first_bb through last_bb's predecessor | |
3165 | end with GIMPLE_COND, all of them have one of the edges to | |
3166 | other_bb and another to another block in the range, | |
3167 | all blocks except first_bb don't have side-effects and | |
3168 | last_bb ends with either GIMPLE_COND, or cast satisfying | |
3169 | final_range_test_p. */ | |
3170 | for (bb = last_bb; ; bb = single_pred (bb)) | |
3171 | { | |
3172 | enum tree_code code; | |
3173 | tree lhs, rhs; | |
3174 | inter_bb_range_test_entry bb_ent; | |
3175 | ||
3176 | bb_ent.op = NULL_TREE; | |
3177 | bb_ent.first_idx = ops.length (); | |
3178 | bb_ent.last_idx = bb_ent.first_idx; | |
3179 | e = find_edge (bb, other_bb); | |
3180 | stmt = last_stmt (bb); | |
3181 | gimple_set_visited (stmt, true); | |
3182 | if (gimple_code (stmt) != GIMPLE_COND) | |
3183 | { | |
3184 | use_operand_p use_p; | |
3185 | gimple phi; | |
3186 | edge e2; | |
3187 | unsigned int d; | |
3188 | ||
3189 | lhs = gimple_assign_lhs (stmt); | |
3190 | rhs = gimple_assign_rhs1 (stmt); | |
3191 | gcc_assert (bb == last_bb); | |
3192 | ||
3193 | /* stmt is | |
3194 | _123 = (int) _234; | |
3195 | ||
3196 | followed by: | |
3197 | <bb M>: | |
3198 | # _345 = PHI <_123(N), 1(...), 1(...)> | |
3199 | ||
3200 | or 0 instead of 1. If it is 0, the _234 | |
3201 | range test is anded together with all the | |
3202 | other range tests, if it is 1, it is ored with | |
3203 | them. */ | |
3204 | single_imm_use (lhs, &use_p, &phi); | |
3205 | gcc_assert (gimple_code (phi) == GIMPLE_PHI); | |
3206 | e2 = find_edge (first_bb, other_bb); | |
3207 | d = e2->dest_idx; | |
3208 | gcc_assert (gimple_phi_arg_def (phi, e->dest_idx) == lhs); | |
3209 | if (integer_zerop (gimple_phi_arg_def (phi, d))) | |
3210 | code = BIT_AND_EXPR; | |
3211 | else | |
3212 | { | |
3213 | gcc_checking_assert (integer_onep (gimple_phi_arg_def (phi, d))); | |
3214 | code = BIT_IOR_EXPR; | |
3215 | } | |
3216 | ||
3217 | /* If _234 SSA_NAME_DEF_STMT is | |
3218 | _234 = _567 | _789; | |
3219 | (or &, corresponding to 1/0 in the phi arguments, | |
3220 | push into ops the individual range test arguments | |
3221 | of the bitwise or resp. and, recursively. */ | |
3222 | if (!get_ops (rhs, code, &ops, | |
3223 | loop_containing_stmt (stmt)) | |
3224 | && has_single_use (rhs)) | |
3225 | { | |
3226 | /* Otherwise, push the _234 range test itself. */ | |
3227 | operand_entry_t oe | |
3228 | = (operand_entry_t) pool_alloc (operand_entry_pool); | |
3229 | ||
3230 | oe->op = rhs; | |
3231 | oe->rank = code; | |
3232 | oe->id = 0; | |
3233 | oe->count = 1; | |
3234 | ops.safe_push (oe); | |
3235 | bb_ent.last_idx++; | |
3236 | } | |
3237 | else | |
3238 | bb_ent.last_idx = ops.length (); | |
3239 | bb_ent.op = rhs; | |
3240 | bbinfo.safe_push (bb_ent); | |
3241 | continue; | |
3242 | } | |
3243 | /* Otherwise stmt is GIMPLE_COND. */ | |
3244 | code = gimple_cond_code (stmt); | |
3245 | lhs = gimple_cond_lhs (stmt); | |
3246 | rhs = gimple_cond_rhs (stmt); | |
3247 | if (TREE_CODE (lhs) == SSA_NAME | |
3248 | && INTEGRAL_TYPE_P (TREE_TYPE (lhs)) | |
3249 | && ((code != EQ_EXPR && code != NE_EXPR) | |
3250 | || rhs != boolean_false_node | |
3251 | /* Either push into ops the individual bitwise | |
3252 | or resp. and operands, depending on which | |
3253 | edge is other_bb. */ | |
3254 | || !get_ops (lhs, (((e->flags & EDGE_TRUE_VALUE) == 0) | |
3255 | ^ (code == EQ_EXPR)) | |
3256 | ? BIT_AND_EXPR : BIT_IOR_EXPR, &ops, | |
3257 | loop_containing_stmt (stmt)))) | |
3258 | { | |
3259 | /* Or push the GIMPLE_COND stmt itself. */ | |
3260 | operand_entry_t oe | |
3261 | = (operand_entry_t) pool_alloc (operand_entry_pool); | |
3262 | ||
3263 | oe->op = NULL; | |
3264 | oe->rank = (e->flags & EDGE_TRUE_VALUE) | |
3265 | ? BIT_IOR_EXPR : BIT_AND_EXPR; | |
3266 | /* oe->op = NULL signs that there is no SSA_NAME | |
3267 | for the range test, and oe->id instead is the | |
3268 | basic block number, at which's end the GIMPLE_COND | |
3269 | is. */ | |
3270 | oe->id = bb->index; | |
3271 | oe->count = 1; | |
3272 | ops.safe_push (oe); | |
3273 | bb_ent.op = NULL; | |
3274 | bb_ent.last_idx++; | |
3275 | } | |
3276 | else if (ops.length () > bb_ent.first_idx) | |
3277 | { | |
3278 | bb_ent.op = lhs; | |
3279 | bb_ent.last_idx = ops.length (); | |
3280 | } | |
3281 | bbinfo.safe_push (bb_ent); | |
3282 | if (bb == first_bb) | |
3283 | break; | |
3284 | } | |
3285 | if (ops.length () > 1) | |
3286 | any_changes = optimize_range_tests (ERROR_MARK, &ops); | |
3287 | if (any_changes) | |
3288 | { | |
3289 | unsigned int idx; | |
3290 | /* update_ops relies on has_single_use predicates returning the | |
3291 | same values as it did during get_ops earlier. Additionally it | |
3292 | never removes statements, only adds new ones and it should walk | |
3293 | from the single imm use and check the predicate already before | |
3294 | making those changes. | |
3295 | On the other side, the handling of GIMPLE_COND directly can turn | |
3296 | previously multiply used SSA_NAMEs into single use SSA_NAMEs, so | |
3297 | it needs to be done in a separate loop afterwards. */ | |
3298 | for (bb = last_bb, idx = 0; ; bb = single_pred (bb), idx++) | |
3299 | { | |
3300 | if (bbinfo[idx].first_idx < bbinfo[idx].last_idx | |
3301 | && bbinfo[idx].op != NULL_TREE) | |
3302 | { | |
3303 | tree new_op; | |
3304 | ||
3305 | stmt = last_stmt (bb); | |
3306 | new_op = update_ops (bbinfo[idx].op, | |
3307 | (enum tree_code) | |
3308 | ops[bbinfo[idx].first_idx]->rank, | |
3309 | ops, &bbinfo[idx].first_idx, | |
3310 | loop_containing_stmt (stmt)); | |
3311 | if (new_op == NULL_TREE) | |
3312 | { | |
3313 | gcc_assert (bb == last_bb); | |
3314 | new_op = ops[bbinfo[idx].first_idx++]->op; | |
3315 | } | |
3316 | if (bbinfo[idx].op != new_op) | |
3317 | { | |
3318 | imm_use_iterator iter; | |
3319 | use_operand_p use_p; | |
3320 | gimple use_stmt, cast_stmt = NULL; | |
3321 | ||
3322 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, bbinfo[idx].op) | |
3323 | if (is_gimple_debug (use_stmt)) | |
3324 | continue; | |
3325 | else if (gimple_code (use_stmt) == GIMPLE_COND | |
3326 | || gimple_code (use_stmt) == GIMPLE_PHI) | |
3327 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
3328 | SET_USE (use_p, new_op); | |
3329 | else if (gimple_assign_cast_p (use_stmt)) | |
3330 | cast_stmt = use_stmt; | |
3331 | else | |
3332 | gcc_unreachable (); | |
3333 | if (cast_stmt) | |
3334 | { | |
3335 | gcc_assert (bb == last_bb); | |
3336 | tree lhs = gimple_assign_lhs (cast_stmt); | |
3337 | tree new_lhs = make_ssa_name (TREE_TYPE (lhs)); | |
3338 | enum tree_code rhs_code | |
3339 | = gimple_assign_rhs_code (cast_stmt); | |
3340 | gassign *g; | |
3341 | if (is_gimple_min_invariant (new_op)) | |
3342 | { | |
3343 | new_op = fold_convert (TREE_TYPE (lhs), new_op); | |
3344 | g = gimple_build_assign (new_lhs, new_op); | |
3345 | } | |
3346 | else | |
3347 | g = gimple_build_assign (new_lhs, rhs_code, new_op); | |
3348 | gimple_stmt_iterator gsi = gsi_for_stmt (cast_stmt); | |
3349 | gimple_set_uid (g, gimple_uid (cast_stmt)); | |
3350 | gimple_set_visited (g, true); | |
3351 | gsi_insert_before (&gsi, g, GSI_SAME_STMT); | |
3352 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) | |
3353 | if (is_gimple_debug (use_stmt)) | |
3354 | continue; | |
3355 | else if (gimple_code (use_stmt) == GIMPLE_COND | |
3356 | || gimple_code (use_stmt) == GIMPLE_PHI) | |
3357 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
3358 | SET_USE (use_p, new_lhs); | |
3359 | else | |
3360 | gcc_unreachable (); | |
3361 | } | |
3362 | } | |
3363 | } | |
3364 | if (bb == first_bb) | |
3365 | break; | |
3366 | } | |
3367 | for (bb = last_bb, idx = 0; ; bb = single_pred (bb), idx++) | |
3368 | { | |
3369 | if (bbinfo[idx].first_idx < bbinfo[idx].last_idx | |
3370 | && bbinfo[idx].op == NULL_TREE | |
3371 | && ops[bbinfo[idx].first_idx]->op != NULL_TREE) | |
3372 | { | |
3373 | gcond *cond_stmt = as_a <gcond *> (last_stmt (bb)); | |
3374 | if (integer_zerop (ops[bbinfo[idx].first_idx]->op)) | |
3375 | gimple_cond_make_false (cond_stmt); | |
3376 | else if (integer_onep (ops[bbinfo[idx].first_idx]->op)) | |
3377 | gimple_cond_make_true (cond_stmt); | |
3378 | else | |
3379 | { | |
3380 | gimple_cond_set_code (cond_stmt, NE_EXPR); | |
3381 | gimple_cond_set_lhs (cond_stmt, | |
3382 | ops[bbinfo[idx].first_idx]->op); | |
3383 | gimple_cond_set_rhs (cond_stmt, boolean_false_node); | |
3384 | } | |
3385 | update_stmt (cond_stmt); | |
3386 | } | |
3387 | if (bb == first_bb) | |
3388 | break; | |
3389 | } | |
3390 | } | |
3391 | } | |
3392 | ||
3393 | /* Return true if OPERAND is defined by a PHI node which uses the LHS | |
3394 | of STMT in it's operands. This is also known as a "destructive | |
3395 | update" operation. */ | |
3396 | ||
3397 | static bool | |
3398 | is_phi_for_stmt (gimple stmt, tree operand) | |
3399 | { | |
3400 | gimple def_stmt; | |
3401 | gphi *def_phi; | |
3402 | tree lhs; | |
3403 | use_operand_p arg_p; | |
3404 | ssa_op_iter i; | |
3405 | ||
3406 | if (TREE_CODE (operand) != SSA_NAME) | |
3407 | return false; | |
3408 | ||
3409 | lhs = gimple_assign_lhs (stmt); | |
3410 | ||
3411 | def_stmt = SSA_NAME_DEF_STMT (operand); | |
3412 | def_phi = dyn_cast <gphi *> (def_stmt); | |
3413 | if (!def_phi) | |
3414 | return false; | |
3415 | ||
3416 | FOR_EACH_PHI_ARG (arg_p, def_phi, i, SSA_OP_USE) | |
3417 | if (lhs == USE_FROM_PTR (arg_p)) | |
3418 | return true; | |
3419 | return false; | |
3420 | } | |
3421 | ||
3422 | /* Remove def stmt of VAR if VAR has zero uses and recurse | |
3423 | on rhs1 operand if so. */ | |
3424 | ||
3425 | static void | |
3426 | remove_visited_stmt_chain (tree var) | |
3427 | { | |
3428 | gimple stmt; | |
3429 | gimple_stmt_iterator gsi; | |
3430 | ||
3431 | while (1) | |
3432 | { | |
3433 | if (TREE_CODE (var) != SSA_NAME || !has_zero_uses (var)) | |
3434 | return; | |
3435 | stmt = SSA_NAME_DEF_STMT (var); | |
3436 | if (is_gimple_assign (stmt) && gimple_visited_p (stmt)) | |
3437 | { | |
3438 | var = gimple_assign_rhs1 (stmt); | |
3439 | gsi = gsi_for_stmt (stmt); | |
3440 | reassoc_remove_stmt (&gsi); | |
3441 | release_defs (stmt); | |
3442 | } | |
3443 | else | |
3444 | return; | |
3445 | } | |
3446 | } | |
3447 | ||
3448 | /* This function checks three consequtive operands in | |
3449 | passed operands vector OPS starting from OPINDEX and | |
3450 | swaps two operands if it is profitable for binary operation | |
3451 | consuming OPINDEX + 1 abnd OPINDEX + 2 operands. | |
3452 | ||
3453 | We pair ops with the same rank if possible. | |
3454 | ||
3455 | The alternative we try is to see if STMT is a destructive | |
3456 | update style statement, which is like: | |
3457 | b = phi (a, ...) | |
3458 | a = c + b; | |
3459 | In that case, we want to use the destructive update form to | |
3460 | expose the possible vectorizer sum reduction opportunity. | |
3461 | In that case, the third operand will be the phi node. This | |
3462 | check is not performed if STMT is null. | |
3463 | ||
3464 | We could, of course, try to be better as noted above, and do a | |
3465 | lot of work to try to find these opportunities in >3 operand | |
3466 | cases, but it is unlikely to be worth it. */ | |
3467 | ||
3468 | static void | |
3469 | swap_ops_for_binary_stmt (vec<operand_entry_t> ops, | |
3470 | unsigned int opindex, gimple stmt) | |
3471 | { | |
3472 | operand_entry_t oe1, oe2, oe3; | |
3473 | ||
3474 | oe1 = ops[opindex]; | |
3475 | oe2 = ops[opindex + 1]; | |
3476 | oe3 = ops[opindex + 2]; | |
3477 | ||
3478 | if ((oe1->rank == oe2->rank | |
3479 | && oe2->rank != oe3->rank) | |
3480 | || (stmt && is_phi_for_stmt (stmt, oe3->op) | |
3481 | && !is_phi_for_stmt (stmt, oe1->op) | |
3482 | && !is_phi_for_stmt (stmt, oe2->op))) | |
3483 | { | |
3484 | struct operand_entry temp = *oe3; | |
3485 | oe3->op = oe1->op; | |
3486 | oe3->rank = oe1->rank; | |
3487 | oe1->op = temp.op; | |
3488 | oe1->rank= temp.rank; | |
3489 | } | |
3490 | else if ((oe1->rank == oe3->rank | |
3491 | && oe2->rank != oe3->rank) | |
3492 | || (stmt && is_phi_for_stmt (stmt, oe2->op) | |
3493 | && !is_phi_for_stmt (stmt, oe1->op) | |
3494 | && !is_phi_for_stmt (stmt, oe3->op))) | |
3495 | { | |
3496 | struct operand_entry temp = *oe2; | |
3497 | oe2->op = oe1->op; | |
3498 | oe2->rank = oe1->rank; | |
3499 | oe1->op = temp.op; | |
3500 | oe1->rank = temp.rank; | |
3501 | } | |
3502 | } | |
3503 | ||
3504 | /* If definition of RHS1 or RHS2 dominates STMT, return the later of those | |
3505 | two definitions, otherwise return STMT. */ | |
3506 | ||
3507 | static inline gimple | |
3508 | find_insert_point (gimple stmt, tree rhs1, tree rhs2) | |
3509 | { | |
3510 | if (TREE_CODE (rhs1) == SSA_NAME | |
3511 | && reassoc_stmt_dominates_stmt_p (stmt, SSA_NAME_DEF_STMT (rhs1))) | |
3512 | stmt = SSA_NAME_DEF_STMT (rhs1); | |
3513 | if (TREE_CODE (rhs2) == SSA_NAME | |
3514 | && reassoc_stmt_dominates_stmt_p (stmt, SSA_NAME_DEF_STMT (rhs2))) | |
3515 | stmt = SSA_NAME_DEF_STMT (rhs2); | |
3516 | return stmt; | |
3517 | } | |
3518 | ||
3519 | /* Recursively rewrite our linearized statements so that the operators | |
3520 | match those in OPS[OPINDEX], putting the computation in rank | |
3521 | order. Return new lhs. */ | |
3522 | ||
3523 | static tree | |
3524 | rewrite_expr_tree (gimple stmt, unsigned int opindex, | |
3525 | vec<operand_entry_t> ops, bool changed) | |
3526 | { | |
3527 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
3528 | tree rhs2 = gimple_assign_rhs2 (stmt); | |
3529 | tree lhs = gimple_assign_lhs (stmt); | |
3530 | operand_entry_t oe; | |
3531 | ||
3532 | /* The final recursion case for this function is that you have | |
3533 | exactly two operations left. | |
224ceb26 | 3534 | If we had exactly one op in the entire list to start with, we |
dda118e3 JM |
3535 | would have never called this function, and the tail recursion |
3536 | rewrites them one at a time. */ | |
3537 | if (opindex + 2 == ops.length ()) | |
3538 | { | |
3539 | operand_entry_t oe1, oe2; | |
3540 | ||
3541 | oe1 = ops[opindex]; | |
3542 | oe2 = ops[opindex + 1]; | |
3543 | ||
3544 | if (rhs1 != oe1->op || rhs2 != oe2->op) | |
3545 | { | |
3546 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); | |
3547 | unsigned int uid = gimple_uid (stmt); | |
3548 | ||
3549 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3550 | { | |
3551 | fprintf (dump_file, "Transforming "); | |
3552 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
3553 | } | |
3554 | ||
224ceb26 JM |
3555 | /* Even when changed is false, reassociation could have e.g. removed |
3556 | some redundant operations, so unless we are just swapping the | |
3557 | arguments or unless there is no change at all (then we just | |
3558 | return lhs), force creation of a new SSA_NAME. */ | |
3559 | if (changed || ((rhs1 != oe2->op || rhs2 != oe1->op) && opindex)) | |
dda118e3 JM |
3560 | { |
3561 | gimple insert_point = find_insert_point (stmt, oe1->op, oe2->op); | |
3562 | lhs = make_ssa_name (TREE_TYPE (lhs)); | |
3563 | stmt | |
3564 | = gimple_build_assign (lhs, gimple_assign_rhs_code (stmt), | |
3565 | oe1->op, oe2->op); | |
3566 | gimple_set_uid (stmt, uid); | |
3567 | gimple_set_visited (stmt, true); | |
3568 | if (insert_point == gsi_stmt (gsi)) | |
3569 | gsi_insert_before (&gsi, stmt, GSI_SAME_STMT); | |
3570 | else | |
3571 | insert_stmt_after (stmt, insert_point); | |
3572 | } | |
3573 | else | |
3574 | { | |
3575 | gcc_checking_assert (find_insert_point (stmt, oe1->op, oe2->op) | |
3576 | == stmt); | |
3577 | gimple_assign_set_rhs1 (stmt, oe1->op); | |
3578 | gimple_assign_set_rhs2 (stmt, oe2->op); | |
3579 | update_stmt (stmt); | |
3580 | } | |
3581 | ||
3582 | if (rhs1 != oe1->op && rhs1 != oe2->op) | |
3583 | remove_visited_stmt_chain (rhs1); | |
3584 | ||
3585 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3586 | { | |
3587 | fprintf (dump_file, " into "); | |
3588 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
3589 | } | |
3590 | } | |
3591 | return lhs; | |
3592 | } | |
3593 | ||
3594 | /* If we hit here, we should have 3 or more ops left. */ | |
3595 | gcc_assert (opindex + 2 < ops.length ()); | |
3596 | ||
3597 | /* Rewrite the next operator. */ | |
3598 | oe = ops[opindex]; | |
3599 | ||
3600 | /* Recurse on the LHS of the binary operator, which is guaranteed to | |
3601 | be the non-leaf side. */ | |
3602 | tree new_rhs1 | |
3603 | = rewrite_expr_tree (SSA_NAME_DEF_STMT (rhs1), opindex + 1, ops, | |
3604 | changed || oe->op != rhs2); | |
3605 | ||
3606 | if (oe->op != rhs2 || new_rhs1 != rhs1) | |
3607 | { | |
3608 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3609 | { | |
3610 | fprintf (dump_file, "Transforming "); | |
3611 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
3612 | } | |
3613 | ||
3614 | /* If changed is false, this is either opindex == 0 | |
3615 | or all outer rhs2's were equal to corresponding oe->op, | |
3616 | and powi_result is NULL. | |
3617 | That means lhs is equivalent before and after reassociation. | |
3618 | Otherwise ensure the old lhs SSA_NAME is not reused and | |
3619 | create a new stmt as well, so that any debug stmts will be | |
3620 | properly adjusted. */ | |
3621 | if (changed) | |
3622 | { | |
3623 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); | |
3624 | unsigned int uid = gimple_uid (stmt); | |
3625 | gimple insert_point = find_insert_point (stmt, new_rhs1, oe->op); | |
3626 | ||
3627 | lhs = make_ssa_name (TREE_TYPE (lhs)); | |
3628 | stmt = gimple_build_assign (lhs, gimple_assign_rhs_code (stmt), | |
3629 | new_rhs1, oe->op); | |
3630 | gimple_set_uid (stmt, uid); | |
3631 | gimple_set_visited (stmt, true); | |
3632 | if (insert_point == gsi_stmt (gsi)) | |
3633 | gsi_insert_before (&gsi, stmt, GSI_SAME_STMT); | |
3634 | else | |
3635 | insert_stmt_after (stmt, insert_point); | |
3636 | } | |
3637 | else | |
3638 | { | |
3639 | gcc_checking_assert (find_insert_point (stmt, new_rhs1, oe->op) | |
3640 | == stmt); | |
3641 | gimple_assign_set_rhs1 (stmt, new_rhs1); | |
3642 | gimple_assign_set_rhs2 (stmt, oe->op); | |
3643 | update_stmt (stmt); | |
3644 | } | |
3645 | ||
3646 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3647 | { | |
3648 | fprintf (dump_file, " into "); | |
3649 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
3650 | } | |
3651 | } | |
3652 | return lhs; | |
3653 | } | |
3654 | ||
3655 | /* Find out how many cycles we need to compute statements chain. | |
3656 | OPS_NUM holds number os statements in a chain. CPU_WIDTH is a | |
3657 | maximum number of independent statements we may execute per cycle. */ | |
3658 | ||
3659 | static int | |
3660 | get_required_cycles (int ops_num, int cpu_width) | |
3661 | { | |
3662 | int res; | |
3663 | int elog; | |
3664 | unsigned int rest; | |
3665 | ||
3666 | /* While we have more than 2 * cpu_width operands | |
3667 | we may reduce number of operands by cpu_width | |
3668 | per cycle. */ | |
3669 | res = ops_num / (2 * cpu_width); | |
3670 | ||
3671 | /* Remained operands count may be reduced twice per cycle | |
3672 | until we have only one operand. */ | |
3673 | rest = (unsigned)(ops_num - res * cpu_width); | |
3674 | elog = exact_log2 (rest); | |
3675 | if (elog >= 0) | |
3676 | res += elog; | |
3677 | else | |
3678 | res += floor_log2 (rest) + 1; | |
3679 | ||
3680 | return res; | |
3681 | } | |
3682 | ||
3683 | /* Returns an optimal number of registers to use for computation of | |
3684 | given statements. */ | |
3685 | ||
3686 | static int | |
3687 | get_reassociation_width (int ops_num, enum tree_code opc, | |
3688 | machine_mode mode) | |
3689 | { | |
3690 | int param_width = PARAM_VALUE (PARAM_TREE_REASSOC_WIDTH); | |
3691 | int width; | |
3692 | int width_min; | |
3693 | int cycles_best; | |
3694 | ||
3695 | if (param_width > 0) | |
3696 | width = param_width; | |
3697 | else | |
3698 | width = targetm.sched.reassociation_width (opc, mode); | |
3699 | ||
3700 | if (width == 1) | |
3701 | return width; | |
3702 | ||
3703 | /* Get the minimal time required for sequence computation. */ | |
3704 | cycles_best = get_required_cycles (ops_num, width); | |
3705 | ||
3706 | /* Check if we may use less width and still compute sequence for | |
3707 | the same time. It will allow us to reduce registers usage. | |
3708 | get_required_cycles is monotonically increasing with lower width | |
3709 | so we can perform a binary search for the minimal width that still | |
3710 | results in the optimal cycle count. */ | |
3711 | width_min = 1; | |
3712 | while (width > width_min) | |
3713 | { | |
3714 | int width_mid = (width + width_min) / 2; | |
3715 | ||
3716 | if (get_required_cycles (ops_num, width_mid) == cycles_best) | |
3717 | width = width_mid; | |
3718 | else if (width_min < width_mid) | |
3719 | width_min = width_mid; | |
3720 | else | |
3721 | break; | |
3722 | } | |
3723 | ||
3724 | return width; | |
3725 | } | |
3726 | ||
3727 | /* Recursively rewrite our linearized statements so that the operators | |
3728 | match those in OPS[OPINDEX], putting the computation in rank | |
3729 | order and trying to allow operations to be executed in | |
3730 | parallel. */ | |
3731 | ||
3732 | static void | |
3733 | rewrite_expr_tree_parallel (gassign *stmt, int width, | |
3734 | vec<operand_entry_t> ops) | |
3735 | { | |
3736 | enum tree_code opcode = gimple_assign_rhs_code (stmt); | |
3737 | int op_num = ops.length (); | |
3738 | int stmt_num = op_num - 1; | |
3739 | gimple *stmts = XALLOCAVEC (gimple, stmt_num); | |
3740 | int op_index = op_num - 1; | |
3741 | int stmt_index = 0; | |
3742 | int ready_stmts_end = 0; | |
3743 | int i = 0; | |
3744 | tree last_rhs1 = gimple_assign_rhs1 (stmt); | |
3745 | ||
3746 | /* We start expression rewriting from the top statements. | |
3747 | So, in this loop we create a full list of statements | |
3748 | we will work with. */ | |
3749 | stmts[stmt_num - 1] = stmt; | |
3750 | for (i = stmt_num - 2; i >= 0; i--) | |
3751 | stmts[i] = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmts[i+1])); | |
3752 | ||
3753 | for (i = 0; i < stmt_num; i++) | |
3754 | { | |
3755 | tree op1, op2; | |
3756 | ||
3757 | /* Determine whether we should use results of | |
3758 | already handled statements or not. */ | |
3759 | if (ready_stmts_end == 0 | |
3760 | && (i - stmt_index >= width || op_index < 1)) | |
3761 | ready_stmts_end = i; | |
3762 | ||
3763 | /* Now we choose operands for the next statement. Non zero | |
3764 | value in ready_stmts_end means here that we should use | |
3765 | the result of already generated statements as new operand. */ | |
3766 | if (ready_stmts_end > 0) | |
3767 | { | |
3768 | op1 = gimple_assign_lhs (stmts[stmt_index++]); | |
3769 | if (ready_stmts_end > stmt_index) | |
3770 | op2 = gimple_assign_lhs (stmts[stmt_index++]); | |
3771 | else if (op_index >= 0) | |
3772 | op2 = ops[op_index--]->op; | |
3773 | else | |
3774 | { | |
3775 | gcc_assert (stmt_index < i); | |
3776 | op2 = gimple_assign_lhs (stmts[stmt_index++]); | |
3777 | } | |
3778 | ||
3779 | if (stmt_index >= ready_stmts_end) | |
3780 | ready_stmts_end = 0; | |
3781 | } | |
3782 | else | |
3783 | { | |
3784 | if (op_index > 1) | |
3785 | swap_ops_for_binary_stmt (ops, op_index - 2, NULL); | |
3786 | op2 = ops[op_index--]->op; | |
3787 | op1 = ops[op_index--]->op; | |
3788 | } | |
3789 | ||
3790 | /* If we emit the last statement then we should put | |
3791 | operands into the last statement. It will also | |
3792 | break the loop. */ | |
3793 | if (op_index < 0 && stmt_index == i) | |
3794 | i = stmt_num - 1; | |
3795 | ||
3796 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3797 | { | |
3798 | fprintf (dump_file, "Transforming "); | |
3799 | print_gimple_stmt (dump_file, stmts[i], 0, 0); | |
3800 | } | |
3801 | ||
3802 | /* We keep original statement only for the last one. All | |
3803 | others are recreated. */ | |
3804 | if (i == stmt_num - 1) | |
3805 | { | |
3806 | gimple_assign_set_rhs1 (stmts[i], op1); | |
3807 | gimple_assign_set_rhs2 (stmts[i], op2); | |
3808 | update_stmt (stmts[i]); | |
3809 | } | |
3810 | else | |
3811 | stmts[i] = build_and_add_sum (TREE_TYPE (last_rhs1), op1, op2, opcode); | |
3812 | ||
3813 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3814 | { | |
3815 | fprintf (dump_file, " into "); | |
3816 | print_gimple_stmt (dump_file, stmts[i], 0, 0); | |
3817 | } | |
3818 | } | |
3819 | ||
3820 | remove_visited_stmt_chain (last_rhs1); | |
3821 | } | |
3822 | ||
3823 | /* Transform STMT, which is really (A +B) + (C + D) into the left | |
3824 | linear form, ((A+B)+C)+D. | |
3825 | Recurse on D if necessary. */ | |
3826 | ||
3827 | static void | |
3828 | linearize_expr (gimple stmt) | |
3829 | { | |
3830 | gimple_stmt_iterator gsi; | |
3831 | gimple binlhs = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt)); | |
3832 | gimple binrhs = SSA_NAME_DEF_STMT (gimple_assign_rhs2 (stmt)); | |
3833 | gimple oldbinrhs = binrhs; | |
3834 | enum tree_code rhscode = gimple_assign_rhs_code (stmt); | |
3835 | gimple newbinrhs = NULL; | |
3836 | struct loop *loop = loop_containing_stmt (stmt); | |
3837 | tree lhs = gimple_assign_lhs (stmt); | |
3838 | ||
3839 | gcc_assert (is_reassociable_op (binlhs, rhscode, loop) | |
3840 | && is_reassociable_op (binrhs, rhscode, loop)); | |
3841 | ||
3842 | gsi = gsi_for_stmt (stmt); | |
3843 | ||
3844 | gimple_assign_set_rhs2 (stmt, gimple_assign_rhs1 (binrhs)); | |
3845 | binrhs = gimple_build_assign (make_ssa_name (TREE_TYPE (lhs)), | |
3846 | gimple_assign_rhs_code (binrhs), | |
3847 | gimple_assign_lhs (binlhs), | |
3848 | gimple_assign_rhs2 (binrhs)); | |
3849 | gimple_assign_set_rhs1 (stmt, gimple_assign_lhs (binrhs)); | |
3850 | gsi_insert_before (&gsi, binrhs, GSI_SAME_STMT); | |
3851 | gimple_set_uid (binrhs, gimple_uid (stmt)); | |
3852 | ||
3853 | if (TREE_CODE (gimple_assign_rhs2 (stmt)) == SSA_NAME) | |
3854 | newbinrhs = SSA_NAME_DEF_STMT (gimple_assign_rhs2 (stmt)); | |
3855 | ||
3856 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3857 | { | |
3858 | fprintf (dump_file, "Linearized: "); | |
3859 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
3860 | } | |
3861 | ||
3862 | reassociate_stats.linearized++; | |
3863 | update_stmt (stmt); | |
3864 | ||
3865 | gsi = gsi_for_stmt (oldbinrhs); | |
3866 | reassoc_remove_stmt (&gsi); | |
3867 | release_defs (oldbinrhs); | |
3868 | ||
3869 | gimple_set_visited (stmt, true); | |
3870 | gimple_set_visited (binlhs, true); | |
3871 | gimple_set_visited (binrhs, true); | |
3872 | ||
3873 | /* Tail recurse on the new rhs if it still needs reassociation. */ | |
3874 | if (newbinrhs && is_reassociable_op (newbinrhs, rhscode, loop)) | |
3875 | /* ??? This should probably be linearize_expr (newbinrhs) but I don't | |
3876 | want to change the algorithm while converting to tuples. */ | |
3877 | linearize_expr (stmt); | |
3878 | } | |
3879 | ||
3880 | /* If LHS has a single immediate use that is a GIMPLE_ASSIGN statement, return | |
3881 | it. Otherwise, return NULL. */ | |
3882 | ||
3883 | static gimple | |
3884 | get_single_immediate_use (tree lhs) | |
3885 | { | |
3886 | use_operand_p immuse; | |
3887 | gimple immusestmt; | |
3888 | ||
3889 | if (TREE_CODE (lhs) == SSA_NAME | |
3890 | && single_imm_use (lhs, &immuse, &immusestmt) | |
3891 | && is_gimple_assign (immusestmt)) | |
3892 | return immusestmt; | |
3893 | ||
3894 | return NULL; | |
3895 | } | |
3896 | ||
3897 | /* Recursively negate the value of TONEGATE, and return the SSA_NAME | |
3898 | representing the negated value. Insertions of any necessary | |
3899 | instructions go before GSI. | |
3900 | This function is recursive in that, if you hand it "a_5" as the | |
3901 | value to negate, and a_5 is defined by "a_5 = b_3 + b_4", it will | |
3902 | transform b_3 + b_4 into a_5 = -b_3 + -b_4. */ | |
3903 | ||
3904 | static tree | |
3905 | negate_value (tree tonegate, gimple_stmt_iterator *gsip) | |
3906 | { | |
3907 | gimple negatedefstmt = NULL; | |
3908 | tree resultofnegate; | |
3909 | gimple_stmt_iterator gsi; | |
3910 | unsigned int uid; | |
3911 | ||
3912 | /* If we are trying to negate a name, defined by an add, negate the | |
3913 | add operands instead. */ | |
3914 | if (TREE_CODE (tonegate) == SSA_NAME) | |
3915 | negatedefstmt = SSA_NAME_DEF_STMT (tonegate); | |
3916 | if (TREE_CODE (tonegate) == SSA_NAME | |
3917 | && is_gimple_assign (negatedefstmt) | |
3918 | && TREE_CODE (gimple_assign_lhs (negatedefstmt)) == SSA_NAME | |
3919 | && has_single_use (gimple_assign_lhs (negatedefstmt)) | |
3920 | && gimple_assign_rhs_code (negatedefstmt) == PLUS_EXPR) | |
3921 | { | |
3922 | tree rhs1 = gimple_assign_rhs1 (negatedefstmt); | |
3923 | tree rhs2 = gimple_assign_rhs2 (negatedefstmt); | |
3924 | tree lhs = gimple_assign_lhs (negatedefstmt); | |
3925 | gimple g; | |
3926 | ||
3927 | gsi = gsi_for_stmt (negatedefstmt); | |
3928 | rhs1 = negate_value (rhs1, &gsi); | |
3929 | ||
3930 | gsi = gsi_for_stmt (negatedefstmt); | |
3931 | rhs2 = negate_value (rhs2, &gsi); | |
3932 | ||
3933 | gsi = gsi_for_stmt (negatedefstmt); | |
3934 | lhs = make_ssa_name (TREE_TYPE (lhs)); | |
3935 | gimple_set_visited (negatedefstmt, true); | |
3936 | g = gimple_build_assign (lhs, PLUS_EXPR, rhs1, rhs2); | |
3937 | gimple_set_uid (g, gimple_uid (negatedefstmt)); | |
3938 | gsi_insert_before (&gsi, g, GSI_SAME_STMT); | |
3939 | return lhs; | |
3940 | } | |
3941 | ||
3942 | tonegate = fold_build1 (NEGATE_EXPR, TREE_TYPE (tonegate), tonegate); | |
3943 | resultofnegate = force_gimple_operand_gsi (gsip, tonegate, true, | |
3944 | NULL_TREE, true, GSI_SAME_STMT); | |
3945 | gsi = *gsip; | |
3946 | uid = gimple_uid (gsi_stmt (gsi)); | |
3947 | for (gsi_prev (&gsi); !gsi_end_p (gsi); gsi_prev (&gsi)) | |
3948 | { | |
3949 | gimple stmt = gsi_stmt (gsi); | |
3950 | if (gimple_uid (stmt) != 0) | |
3951 | break; | |
3952 | gimple_set_uid (stmt, uid); | |
3953 | } | |
3954 | return resultofnegate; | |
3955 | } | |
3956 | ||
3957 | /* Return true if we should break up the subtract in STMT into an add | |
3958 | with negate. This is true when we the subtract operands are really | |
3959 | adds, or the subtract itself is used in an add expression. In | |
3960 | either case, breaking up the subtract into an add with negate | |
3961 | exposes the adds to reassociation. */ | |
3962 | ||
3963 | static bool | |
3964 | should_break_up_subtract (gimple stmt) | |
3965 | { | |
3966 | tree lhs = gimple_assign_lhs (stmt); | |
3967 | tree binlhs = gimple_assign_rhs1 (stmt); | |
3968 | tree binrhs = gimple_assign_rhs2 (stmt); | |
3969 | gimple immusestmt; | |
3970 | struct loop *loop = loop_containing_stmt (stmt); | |
3971 | ||
3972 | if (TREE_CODE (binlhs) == SSA_NAME | |
3973 | && is_reassociable_op (SSA_NAME_DEF_STMT (binlhs), PLUS_EXPR, loop)) | |
3974 | return true; | |
3975 | ||
3976 | if (TREE_CODE (binrhs) == SSA_NAME | |
3977 | && is_reassociable_op (SSA_NAME_DEF_STMT (binrhs), PLUS_EXPR, loop)) | |
3978 | return true; | |
3979 | ||
3980 | if (TREE_CODE (lhs) == SSA_NAME | |
3981 | && (immusestmt = get_single_immediate_use (lhs)) | |
3982 | && is_gimple_assign (immusestmt) | |
3983 | && (gimple_assign_rhs_code (immusestmt) == PLUS_EXPR | |
3984 | || gimple_assign_rhs_code (immusestmt) == MULT_EXPR)) | |
3985 | return true; | |
3986 | return false; | |
3987 | } | |
3988 | ||
3989 | /* Transform STMT from A - B into A + -B. */ | |
3990 | ||
3991 | static void | |
3992 | break_up_subtract (gimple stmt, gimple_stmt_iterator *gsip) | |
3993 | { | |
3994 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
3995 | tree rhs2 = gimple_assign_rhs2 (stmt); | |
3996 | ||
3997 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3998 | { | |
3999 | fprintf (dump_file, "Breaking up subtract "); | |
4000 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
4001 | } | |
4002 | ||
4003 | rhs2 = negate_value (rhs2, gsip); | |
4004 | gimple_assign_set_rhs_with_ops (gsip, PLUS_EXPR, rhs1, rhs2); | |
4005 | update_stmt (stmt); | |
4006 | } | |
4007 | ||
4008 | /* Determine whether STMT is a builtin call that raises an SSA name | |
4009 | to an integer power and has only one use. If so, and this is early | |
4010 | reassociation and unsafe math optimizations are permitted, place | |
4011 | the SSA name in *BASE and the exponent in *EXPONENT, and return TRUE. | |
4012 | If any of these conditions does not hold, return FALSE. */ | |
4013 | ||
4014 | static bool | |
4015 | acceptable_pow_call (gimple stmt, tree *base, HOST_WIDE_INT *exponent) | |
4016 | { | |
4017 | tree fndecl, arg1; | |
4018 | REAL_VALUE_TYPE c, cint; | |
4019 | ||
4020 | if (!first_pass_instance | |
4021 | || !flag_unsafe_math_optimizations | |
4022 | || !is_gimple_call (stmt) | |
4023 | || !has_single_use (gimple_call_lhs (stmt))) | |
4024 | return false; | |
4025 | ||
4026 | fndecl = gimple_call_fndecl (stmt); | |
4027 | ||
4028 | if (!fndecl | |
4029 | || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL) | |
4030 | return false; | |
4031 | ||
4032 | switch (DECL_FUNCTION_CODE (fndecl)) | |
4033 | { | |
4034 | CASE_FLT_FN (BUILT_IN_POW): | |
4035 | if (flag_errno_math) | |
4036 | return false; | |
4037 | ||
4038 | *base = gimple_call_arg (stmt, 0); | |
4039 | arg1 = gimple_call_arg (stmt, 1); | |
4040 | ||
4041 | if (TREE_CODE (arg1) != REAL_CST) | |
4042 | return false; | |
4043 | ||
4044 | c = TREE_REAL_CST (arg1); | |
4045 | ||
4046 | if (REAL_EXP (&c) > HOST_BITS_PER_WIDE_INT) | |
4047 | return false; | |
4048 | ||
4049 | *exponent = real_to_integer (&c); | |
4050 | real_from_integer (&cint, VOIDmode, *exponent, SIGNED); | |
4051 | if (!real_identical (&c, &cint)) | |
4052 | return false; | |
4053 | ||
4054 | break; | |
4055 | ||
4056 | CASE_FLT_FN (BUILT_IN_POWI): | |
4057 | *base = gimple_call_arg (stmt, 0); | |
4058 | arg1 = gimple_call_arg (stmt, 1); | |
4059 | ||
4060 | if (!tree_fits_shwi_p (arg1)) | |
4061 | return false; | |
4062 | ||
4063 | *exponent = tree_to_shwi (arg1); | |
4064 | break; | |
4065 | ||
4066 | default: | |
4067 | return false; | |
4068 | } | |
4069 | ||
4070 | /* Expanding negative exponents is generally unproductive, so we don't | |
4071 | complicate matters with those. Exponents of zero and one should | |
4072 | have been handled by expression folding. */ | |
4073 | if (*exponent < 2 || TREE_CODE (*base) != SSA_NAME) | |
4074 | return false; | |
4075 | ||
4076 | return true; | |
4077 | } | |
4078 | ||
4079 | /* Recursively linearize a binary expression that is the RHS of STMT. | |
4080 | Place the operands of the expression tree in the vector named OPS. */ | |
4081 | ||
4082 | static void | |
4083 | linearize_expr_tree (vec<operand_entry_t> *ops, gimple stmt, | |
4084 | bool is_associative, bool set_visited) | |
4085 | { | |
4086 | tree binlhs = gimple_assign_rhs1 (stmt); | |
4087 | tree binrhs = gimple_assign_rhs2 (stmt); | |
4088 | gimple binlhsdef = NULL, binrhsdef = NULL; | |
4089 | bool binlhsisreassoc = false; | |
4090 | bool binrhsisreassoc = false; | |
4091 | enum tree_code rhscode = gimple_assign_rhs_code (stmt); | |
4092 | struct loop *loop = loop_containing_stmt (stmt); | |
4093 | tree base = NULL_TREE; | |
4094 | HOST_WIDE_INT exponent = 0; | |
4095 | ||
4096 | if (set_visited) | |
4097 | gimple_set_visited (stmt, true); | |
4098 | ||
4099 | if (TREE_CODE (binlhs) == SSA_NAME) | |
4100 | { | |
4101 | binlhsdef = SSA_NAME_DEF_STMT (binlhs); | |
4102 | binlhsisreassoc = (is_reassociable_op (binlhsdef, rhscode, loop) | |
4103 | && !stmt_could_throw_p (binlhsdef)); | |
4104 | } | |
4105 | ||
4106 | if (TREE_CODE (binrhs) == SSA_NAME) | |
4107 | { | |
4108 | binrhsdef = SSA_NAME_DEF_STMT (binrhs); | |
4109 | binrhsisreassoc = (is_reassociable_op (binrhsdef, rhscode, loop) | |
4110 | && !stmt_could_throw_p (binrhsdef)); | |
4111 | } | |
4112 | ||
4113 | /* If the LHS is not reassociable, but the RHS is, we need to swap | |
4114 | them. If neither is reassociable, there is nothing we can do, so | |
4115 | just put them in the ops vector. If the LHS is reassociable, | |
4116 | linearize it. If both are reassociable, then linearize the RHS | |
4117 | and the LHS. */ | |
4118 | ||
4119 | if (!binlhsisreassoc) | |
4120 | { | |
4121 | tree temp; | |
4122 | ||
4123 | /* If this is not a associative operation like division, give up. */ | |
4124 | if (!is_associative) | |
4125 | { | |
4126 | add_to_ops_vec (ops, binrhs); | |
4127 | return; | |
4128 | } | |
4129 | ||
4130 | if (!binrhsisreassoc) | |
4131 | { | |
4132 | if (rhscode == MULT_EXPR | |
4133 | && TREE_CODE (binrhs) == SSA_NAME | |
4134 | && acceptable_pow_call (binrhsdef, &base, &exponent)) | |
4135 | { | |
4136 | add_repeat_to_ops_vec (ops, base, exponent); | |
4137 | gimple_set_visited (binrhsdef, true); | |
4138 | } | |
4139 | else | |
4140 | add_to_ops_vec (ops, binrhs); | |
4141 | ||
4142 | if (rhscode == MULT_EXPR | |
4143 | && TREE_CODE (binlhs) == SSA_NAME | |
4144 | && acceptable_pow_call (binlhsdef, &base, &exponent)) | |
4145 | { | |
4146 | add_repeat_to_ops_vec (ops, base, exponent); | |
4147 | gimple_set_visited (binlhsdef, true); | |
4148 | } | |
4149 | else | |
4150 | add_to_ops_vec (ops, binlhs); | |
4151 | ||
4152 | return; | |
4153 | } | |
4154 | ||
4155 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4156 | { | |
4157 | fprintf (dump_file, "swapping operands of "); | |
4158 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
4159 | } | |
4160 | ||
4161 | swap_ssa_operands (stmt, | |
4162 | gimple_assign_rhs1_ptr (stmt), | |
4163 | gimple_assign_rhs2_ptr (stmt)); | |
4164 | update_stmt (stmt); | |
4165 | ||
4166 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4167 | { | |
4168 | fprintf (dump_file, " is now "); | |
4169 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
4170 | } | |
4171 | ||
4172 | /* We want to make it so the lhs is always the reassociative op, | |
4173 | so swap. */ | |
4174 | temp = binlhs; | |
4175 | binlhs = binrhs; | |
4176 | binrhs = temp; | |
4177 | } | |
4178 | else if (binrhsisreassoc) | |
4179 | { | |
4180 | linearize_expr (stmt); | |
4181 | binlhs = gimple_assign_rhs1 (stmt); | |
4182 | binrhs = gimple_assign_rhs2 (stmt); | |
4183 | } | |
4184 | ||
4185 | gcc_assert (TREE_CODE (binrhs) != SSA_NAME | |
4186 | || !is_reassociable_op (SSA_NAME_DEF_STMT (binrhs), | |
4187 | rhscode, loop)); | |
4188 | linearize_expr_tree (ops, SSA_NAME_DEF_STMT (binlhs), | |
4189 | is_associative, set_visited); | |
4190 | ||
4191 | if (rhscode == MULT_EXPR | |
4192 | && TREE_CODE (binrhs) == SSA_NAME | |
4193 | && acceptable_pow_call (SSA_NAME_DEF_STMT (binrhs), &base, &exponent)) | |
4194 | { | |
4195 | add_repeat_to_ops_vec (ops, base, exponent); | |
4196 | gimple_set_visited (SSA_NAME_DEF_STMT (binrhs), true); | |
4197 | } | |
4198 | else | |
4199 | add_to_ops_vec (ops, binrhs); | |
4200 | } | |
4201 | ||
4202 | /* Repropagate the negates back into subtracts, since no other pass | |
4203 | currently does it. */ | |
4204 | ||
4205 | static void | |
4206 | repropagate_negates (void) | |
4207 | { | |
4208 | unsigned int i = 0; | |
4209 | tree negate; | |
4210 | ||
4211 | FOR_EACH_VEC_ELT (plus_negates, i, negate) | |
4212 | { | |
4213 | gimple user = get_single_immediate_use (negate); | |
4214 | ||
4215 | if (!user || !is_gimple_assign (user)) | |
4216 | continue; | |
4217 | ||
4218 | /* The negate operand can be either operand of a PLUS_EXPR | |
4219 | (it can be the LHS if the RHS is a constant for example). | |
4220 | ||
4221 | Force the negate operand to the RHS of the PLUS_EXPR, then | |
4222 | transform the PLUS_EXPR into a MINUS_EXPR. */ | |
4223 | if (gimple_assign_rhs_code (user) == PLUS_EXPR) | |
4224 | { | |
4225 | /* If the negated operand appears on the LHS of the | |
4226 | PLUS_EXPR, exchange the operands of the PLUS_EXPR | |
4227 | to force the negated operand to the RHS of the PLUS_EXPR. */ | |
4228 | if (gimple_assign_rhs1 (user) == negate) | |
4229 | { | |
4230 | swap_ssa_operands (user, | |
4231 | gimple_assign_rhs1_ptr (user), | |
4232 | gimple_assign_rhs2_ptr (user)); | |
4233 | } | |
4234 | ||
4235 | /* Now transform the PLUS_EXPR into a MINUS_EXPR and replace | |
4236 | the RHS of the PLUS_EXPR with the operand of the NEGATE_EXPR. */ | |
4237 | if (gimple_assign_rhs2 (user) == negate) | |
4238 | { | |
4239 | tree rhs1 = gimple_assign_rhs1 (user); | |
4240 | tree rhs2 = get_unary_op (negate, NEGATE_EXPR); | |
4241 | gimple_stmt_iterator gsi = gsi_for_stmt (user); | |
4242 | gimple_assign_set_rhs_with_ops (&gsi, MINUS_EXPR, rhs1, rhs2); | |
4243 | update_stmt (user); | |
4244 | } | |
4245 | } | |
4246 | else if (gimple_assign_rhs_code (user) == MINUS_EXPR) | |
4247 | { | |
4248 | if (gimple_assign_rhs1 (user) == negate) | |
4249 | { | |
4250 | /* We have | |
4251 | x = -a | |
4252 | y = x - b | |
4253 | which we transform into | |
4254 | x = a + b | |
4255 | y = -x . | |
4256 | This pushes down the negate which we possibly can merge | |
4257 | into some other operation, hence insert it into the | |
4258 | plus_negates vector. */ | |
4259 | gimple feed = SSA_NAME_DEF_STMT (negate); | |
4260 | tree a = gimple_assign_rhs1 (feed); | |
4261 | tree b = gimple_assign_rhs2 (user); | |
4262 | gimple_stmt_iterator gsi = gsi_for_stmt (feed); | |
4263 | gimple_stmt_iterator gsi2 = gsi_for_stmt (user); | |
4264 | tree x = make_ssa_name (TREE_TYPE (gimple_assign_lhs (feed))); | |
4265 | gimple g = gimple_build_assign (x, PLUS_EXPR, a, b); | |
4266 | gsi_insert_before (&gsi2, g, GSI_SAME_STMT); | |
4267 | gimple_assign_set_rhs_with_ops (&gsi2, NEGATE_EXPR, x); | |
4268 | user = gsi_stmt (gsi2); | |
4269 | update_stmt (user); | |
4270 | reassoc_remove_stmt (&gsi); | |
4271 | release_defs (feed); | |
4272 | plus_negates.safe_push (gimple_assign_lhs (user)); | |
4273 | } | |
4274 | else | |
4275 | { | |
4276 | /* Transform "x = -a; y = b - x" into "y = b + a", getting | |
4277 | rid of one operation. */ | |
4278 | gimple feed = SSA_NAME_DEF_STMT (negate); | |
4279 | tree a = gimple_assign_rhs1 (feed); | |
4280 | tree rhs1 = gimple_assign_rhs1 (user); | |
4281 | gimple_stmt_iterator gsi = gsi_for_stmt (user); | |
4282 | gimple_assign_set_rhs_with_ops (&gsi, PLUS_EXPR, rhs1, a); | |
4283 | update_stmt (gsi_stmt (gsi)); | |
4284 | } | |
4285 | } | |
4286 | } | |
4287 | } | |
4288 | ||
4289 | /* Returns true if OP is of a type for which we can do reassociation. | |
4290 | That is for integral or non-saturating fixed-point types, and for | |
4291 | floating point type when associative-math is enabled. */ | |
4292 | ||
4293 | static bool | |
4294 | can_reassociate_p (tree op) | |
4295 | { | |
4296 | tree type = TREE_TYPE (op); | |
4297 | if ((INTEGRAL_TYPE_P (type) && TYPE_OVERFLOW_WRAPS (type)) | |
4298 | || NON_SAT_FIXED_POINT_TYPE_P (type) | |
4299 | || (flag_associative_math && FLOAT_TYPE_P (type))) | |
4300 | return true; | |
4301 | return false; | |
4302 | } | |
4303 | ||
4304 | /* Break up subtract operations in block BB. | |
4305 | ||
4306 | We do this top down because we don't know whether the subtract is | |
4307 | part of a possible chain of reassociation except at the top. | |
4308 | ||
4309 | IE given | |
4310 | d = f + g | |
4311 | c = a + e | |
4312 | b = c - d | |
4313 | q = b - r | |
4314 | k = t - q | |
4315 | ||
4316 | we want to break up k = t - q, but we won't until we've transformed q | |
4317 | = b - r, which won't be broken up until we transform b = c - d. | |
4318 | ||
4319 | En passant, clear the GIMPLE visited flag on every statement | |
4320 | and set UIDs within each basic block. */ | |
4321 | ||
4322 | static void | |
4323 | break_up_subtract_bb (basic_block bb) | |
4324 | { | |
4325 | gimple_stmt_iterator gsi; | |
4326 | basic_block son; | |
4327 | unsigned int uid = 1; | |
4328 | ||
4329 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
4330 | { | |
4331 | gimple stmt = gsi_stmt (gsi); | |
4332 | gimple_set_visited (stmt, false); | |
4333 | gimple_set_uid (stmt, uid++); | |
4334 | ||
4335 | if (!is_gimple_assign (stmt) | |
4336 | || !can_reassociate_p (gimple_assign_lhs (stmt))) | |
4337 | continue; | |
4338 | ||
4339 | /* Look for simple gimple subtract operations. */ | |
4340 | if (gimple_assign_rhs_code (stmt) == MINUS_EXPR) | |
4341 | { | |
4342 | if (!can_reassociate_p (gimple_assign_rhs1 (stmt)) | |
4343 | || !can_reassociate_p (gimple_assign_rhs2 (stmt))) | |
4344 | continue; | |
4345 | ||
4346 | /* Check for a subtract used only in an addition. If this | |
4347 | is the case, transform it into add of a negate for better | |
4348 | reassociation. IE transform C = A-B into C = A + -B if C | |
4349 | is only used in an addition. */ | |
4350 | if (should_break_up_subtract (stmt)) | |
4351 | break_up_subtract (stmt, &gsi); | |
4352 | } | |
4353 | else if (gimple_assign_rhs_code (stmt) == NEGATE_EXPR | |
4354 | && can_reassociate_p (gimple_assign_rhs1 (stmt))) | |
4355 | plus_negates.safe_push (gimple_assign_lhs (stmt)); | |
4356 | } | |
4357 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
4358 | son; | |
4359 | son = next_dom_son (CDI_DOMINATORS, son)) | |
4360 | break_up_subtract_bb (son); | |
4361 | } | |
4362 | ||
4363 | /* Used for repeated factor analysis. */ | |
4364 | struct repeat_factor_d | |
4365 | { | |
4366 | /* An SSA name that occurs in a multiply chain. */ | |
4367 | tree factor; | |
4368 | ||
4369 | /* Cached rank of the factor. */ | |
4370 | unsigned rank; | |
4371 | ||
4372 | /* Number of occurrences of the factor in the chain. */ | |
4373 | HOST_WIDE_INT count; | |
4374 | ||
4375 | /* An SSA name representing the product of this factor and | |
4376 | all factors appearing later in the repeated factor vector. */ | |
4377 | tree repr; | |
4378 | }; | |
4379 | ||
4380 | typedef struct repeat_factor_d repeat_factor, *repeat_factor_t; | |
4381 | typedef const struct repeat_factor_d *const_repeat_factor_t; | |
4382 | ||
4383 | ||
4384 | static vec<repeat_factor> repeat_factor_vec; | |
4385 | ||
4386 | /* Used for sorting the repeat factor vector. Sort primarily by | |
4387 | ascending occurrence count, secondarily by descending rank. */ | |
4388 | ||
4389 | static int | |
4390 | compare_repeat_factors (const void *x1, const void *x2) | |
4391 | { | |
4392 | const_repeat_factor_t rf1 = (const_repeat_factor_t) x1; | |
4393 | const_repeat_factor_t rf2 = (const_repeat_factor_t) x2; | |
4394 | ||
4395 | if (rf1->count != rf2->count) | |
4396 | return rf1->count - rf2->count; | |
4397 | ||
4398 | return rf2->rank - rf1->rank; | |
4399 | } | |
4400 | ||
4401 | /* Look for repeated operands in OPS in the multiply tree rooted at | |
4402 | STMT. Replace them with an optimal sequence of multiplies and powi | |
4403 | builtin calls, and remove the used operands from OPS. Return an | |
4404 | SSA name representing the value of the replacement sequence. */ | |
4405 | ||
4406 | static tree | |
4407 | attempt_builtin_powi (gimple stmt, vec<operand_entry_t> *ops) | |
4408 | { | |
4409 | unsigned i, j, vec_len; | |
4410 | int ii; | |
4411 | operand_entry_t oe; | |
4412 | repeat_factor_t rf1, rf2; | |
4413 | repeat_factor rfnew; | |
4414 | tree result = NULL_TREE; | |
4415 | tree target_ssa, iter_result; | |
4416 | tree type = TREE_TYPE (gimple_get_lhs (stmt)); | |
4417 | tree powi_fndecl = mathfn_built_in (type, BUILT_IN_POWI); | |
4418 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); | |
4419 | gimple mul_stmt, pow_stmt; | |
4420 | ||
4421 | /* Nothing to do if BUILT_IN_POWI doesn't exist for this type and | |
4422 | target. */ | |
4423 | if (!powi_fndecl) | |
4424 | return NULL_TREE; | |
4425 | ||
4426 | /* Allocate the repeated factor vector. */ | |
4427 | repeat_factor_vec.create (10); | |
4428 | ||
4429 | /* Scan the OPS vector for all SSA names in the product and build | |
4430 | up a vector of occurrence counts for each factor. */ | |
4431 | FOR_EACH_VEC_ELT (*ops, i, oe) | |
4432 | { | |
4433 | if (TREE_CODE (oe->op) == SSA_NAME) | |
4434 | { | |
4435 | FOR_EACH_VEC_ELT (repeat_factor_vec, j, rf1) | |
4436 | { | |
4437 | if (rf1->factor == oe->op) | |
4438 | { | |
4439 | rf1->count += oe->count; | |
4440 | break; | |
4441 | } | |
4442 | } | |
4443 | ||
4444 | if (j >= repeat_factor_vec.length ()) | |
4445 | { | |
4446 | rfnew.factor = oe->op; | |
4447 | rfnew.rank = oe->rank; | |
4448 | rfnew.count = oe->count; | |
4449 | rfnew.repr = NULL_TREE; | |
4450 | repeat_factor_vec.safe_push (rfnew); | |
4451 | } | |
4452 | } | |
4453 | } | |
4454 | ||
4455 | /* Sort the repeated factor vector by (a) increasing occurrence count, | |
4456 | and (b) decreasing rank. */ | |
4457 | repeat_factor_vec.qsort (compare_repeat_factors); | |
4458 | ||
4459 | /* It is generally best to combine as many base factors as possible | |
4460 | into a product before applying __builtin_powi to the result. | |
4461 | However, the sort order chosen for the repeated factor vector | |
4462 | allows us to cache partial results for the product of the base | |
4463 | factors for subsequent use. When we already have a cached partial | |
4464 | result from a previous iteration, it is best to make use of it | |
4465 | before looking for another __builtin_pow opportunity. | |
4466 | ||
4467 | As an example, consider x * x * y * y * y * z * z * z * z. | |
4468 | We want to first compose the product x * y * z, raise it to the | |
4469 | second power, then multiply this by y * z, and finally multiply | |
4470 | by z. This can be done in 5 multiplies provided we cache y * z | |
4471 | for use in both expressions: | |
4472 | ||
4473 | t1 = y * z | |
4474 | t2 = t1 * x | |
4475 | t3 = t2 * t2 | |
4476 | t4 = t1 * t3 | |
4477 | result = t4 * z | |
4478 | ||
4479 | If we instead ignored the cached y * z and first multiplied by | |
4480 | the __builtin_pow opportunity z * z, we would get the inferior: | |
4481 | ||
4482 | t1 = y * z | |
4483 | t2 = t1 * x | |
4484 | t3 = t2 * t2 | |
4485 | t4 = z * z | |
4486 | t5 = t3 * t4 | |
4487 | result = t5 * y */ | |
4488 | ||
4489 | vec_len = repeat_factor_vec.length (); | |
4490 | ||
4491 | /* Repeatedly look for opportunities to create a builtin_powi call. */ | |
4492 | while (true) | |
4493 | { | |
4494 | HOST_WIDE_INT power; | |
4495 | ||
4496 | /* First look for the largest cached product of factors from | |
4497 | preceding iterations. If found, create a builtin_powi for | |
4498 | it if the minimum occurrence count for its factors is at | |
4499 | least 2, or just use this cached product as our next | |
4500 | multiplicand if the minimum occurrence count is 1. */ | |
4501 | FOR_EACH_VEC_ELT (repeat_factor_vec, j, rf1) | |
4502 | { | |
4503 | if (rf1->repr && rf1->count > 0) | |
4504 | break; | |
4505 | } | |
4506 | ||
4507 | if (j < vec_len) | |
4508 | { | |
4509 | power = rf1->count; | |
4510 | ||
4511 | if (power == 1) | |
4512 | { | |
4513 | iter_result = rf1->repr; | |
4514 | ||
4515 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4516 | { | |
4517 | unsigned elt; | |
4518 | repeat_factor_t rf; | |
4519 | fputs ("Multiplying by cached product ", dump_file); | |
4520 | for (elt = j; elt < vec_len; elt++) | |
4521 | { | |
4522 | rf = &repeat_factor_vec[elt]; | |
4523 | print_generic_expr (dump_file, rf->factor, 0); | |
4524 | if (elt < vec_len - 1) | |
4525 | fputs (" * ", dump_file); | |
4526 | } | |
4527 | fputs ("\n", dump_file); | |
4528 | } | |
4529 | } | |
4530 | else | |
4531 | { | |
4532 | iter_result = make_temp_ssa_name (type, NULL, "reassocpow"); | |
4533 | pow_stmt = gimple_build_call (powi_fndecl, 2, rf1->repr, | |
4534 | build_int_cst (integer_type_node, | |
4535 | power)); | |
4536 | gimple_call_set_lhs (pow_stmt, iter_result); | |
4537 | gimple_set_location (pow_stmt, gimple_location (stmt)); | |
7d4d0543 | 4538 | gimple_set_uid (pow_stmt, gimple_uid (stmt)); |
dda118e3 JM |
4539 | gsi_insert_before (&gsi, pow_stmt, GSI_SAME_STMT); |
4540 | ||
4541 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4542 | { | |
4543 | unsigned elt; | |
4544 | repeat_factor_t rf; | |
4545 | fputs ("Building __builtin_pow call for cached product (", | |
4546 | dump_file); | |
4547 | for (elt = j; elt < vec_len; elt++) | |
4548 | { | |
4549 | rf = &repeat_factor_vec[elt]; | |
4550 | print_generic_expr (dump_file, rf->factor, 0); | |
4551 | if (elt < vec_len - 1) | |
4552 | fputs (" * ", dump_file); | |
4553 | } | |
4554 | fprintf (dump_file, ")^"HOST_WIDE_INT_PRINT_DEC"\n", | |
4555 | power); | |
4556 | } | |
4557 | } | |
4558 | } | |
4559 | else | |
4560 | { | |
4561 | /* Otherwise, find the first factor in the repeated factor | |
4562 | vector whose occurrence count is at least 2. If no such | |
4563 | factor exists, there are no builtin_powi opportunities | |
4564 | remaining. */ | |
4565 | FOR_EACH_VEC_ELT (repeat_factor_vec, j, rf1) | |
4566 | { | |
4567 | if (rf1->count >= 2) | |
4568 | break; | |
4569 | } | |
4570 | ||
4571 | if (j >= vec_len) | |
4572 | break; | |
4573 | ||
4574 | power = rf1->count; | |
4575 | ||
4576 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4577 | { | |
4578 | unsigned elt; | |
4579 | repeat_factor_t rf; | |
4580 | fputs ("Building __builtin_pow call for (", dump_file); | |
4581 | for (elt = j; elt < vec_len; elt++) | |
4582 | { | |
4583 | rf = &repeat_factor_vec[elt]; | |
4584 | print_generic_expr (dump_file, rf->factor, 0); | |
4585 | if (elt < vec_len - 1) | |
4586 | fputs (" * ", dump_file); | |
4587 | } | |
4588 | fprintf (dump_file, ")^"HOST_WIDE_INT_PRINT_DEC"\n", power); | |
4589 | } | |
4590 | ||
4591 | reassociate_stats.pows_created++; | |
4592 | ||
4593 | /* Visit each element of the vector in reverse order (so that | |
4594 | high-occurrence elements are visited first, and within the | |
4595 | same occurrence count, lower-ranked elements are visited | |
4596 | first). Form a linear product of all elements in this order | |
4597 | whose occurrencce count is at least that of element J. | |
4598 | Record the SSA name representing the product of each element | |
4599 | with all subsequent elements in the vector. */ | |
4600 | if (j == vec_len - 1) | |
4601 | rf1->repr = rf1->factor; | |
4602 | else | |
4603 | { | |
4604 | for (ii = vec_len - 2; ii >= (int)j; ii--) | |
4605 | { | |
4606 | tree op1, op2; | |
4607 | ||
4608 | rf1 = &repeat_factor_vec[ii]; | |
4609 | rf2 = &repeat_factor_vec[ii + 1]; | |
4610 | ||
4611 | /* Init the last factor's representative to be itself. */ | |
4612 | if (!rf2->repr) | |
4613 | rf2->repr = rf2->factor; | |
4614 | ||
4615 | op1 = rf1->factor; | |
4616 | op2 = rf2->repr; | |
4617 | ||
4618 | target_ssa = make_temp_ssa_name (type, NULL, "reassocpow"); | |
4619 | mul_stmt = gimple_build_assign (target_ssa, MULT_EXPR, | |
4620 | op1, op2); | |
4621 | gimple_set_location (mul_stmt, gimple_location (stmt)); | |
7d4d0543 | 4622 | gimple_set_uid (mul_stmt, gimple_uid (stmt)); |
dda118e3 JM |
4623 | gsi_insert_before (&gsi, mul_stmt, GSI_SAME_STMT); |
4624 | rf1->repr = target_ssa; | |
4625 | ||
4626 | /* Don't reprocess the multiply we just introduced. */ | |
4627 | gimple_set_visited (mul_stmt, true); | |
4628 | } | |
4629 | } | |
4630 | ||
4631 | /* Form a call to __builtin_powi for the maximum product | |
4632 | just formed, raised to the power obtained earlier. */ | |
4633 | rf1 = &repeat_factor_vec[j]; | |
4634 | iter_result = make_temp_ssa_name (type, NULL, "reassocpow"); | |
4635 | pow_stmt = gimple_build_call (powi_fndecl, 2, rf1->repr, | |
4636 | build_int_cst (integer_type_node, | |
4637 | power)); | |
4638 | gimple_call_set_lhs (pow_stmt, iter_result); | |
4639 | gimple_set_location (pow_stmt, gimple_location (stmt)); | |
7d4d0543 | 4640 | gimple_set_uid (pow_stmt, gimple_uid (stmt)); |
dda118e3 JM |
4641 | gsi_insert_before (&gsi, pow_stmt, GSI_SAME_STMT); |
4642 | } | |
4643 | ||
4644 | /* If we previously formed at least one other builtin_powi call, | |
4645 | form the product of this one and those others. */ | |
4646 | if (result) | |
4647 | { | |
4648 | tree new_result = make_temp_ssa_name (type, NULL, "reassocpow"); | |
4649 | mul_stmt = gimple_build_assign (new_result, MULT_EXPR, | |
4650 | result, iter_result); | |
4651 | gimple_set_location (mul_stmt, gimple_location (stmt)); | |
7d4d0543 | 4652 | gimple_set_uid (mul_stmt, gimple_uid (stmt)); |
dda118e3 JM |
4653 | gsi_insert_before (&gsi, mul_stmt, GSI_SAME_STMT); |
4654 | gimple_set_visited (mul_stmt, true); | |
4655 | result = new_result; | |
4656 | } | |
4657 | else | |
4658 | result = iter_result; | |
4659 | ||
4660 | /* Decrement the occurrence count of each element in the product | |
4661 | by the count found above, and remove this many copies of each | |
4662 | factor from OPS. */ | |
4663 | for (i = j; i < vec_len; i++) | |
4664 | { | |
4665 | unsigned k = power; | |
4666 | unsigned n; | |
4667 | ||
4668 | rf1 = &repeat_factor_vec[i]; | |
4669 | rf1->count -= power; | |
4670 | ||
4671 | FOR_EACH_VEC_ELT_REVERSE (*ops, n, oe) | |
4672 | { | |
4673 | if (oe->op == rf1->factor) | |
4674 | { | |
4675 | if (oe->count <= k) | |
4676 | { | |
4677 | ops->ordered_remove (n); | |
4678 | k -= oe->count; | |
4679 | ||
4680 | if (k == 0) | |
4681 | break; | |
4682 | } | |
4683 | else | |
4684 | { | |
4685 | oe->count -= k; | |
4686 | break; | |
4687 | } | |
4688 | } | |
4689 | } | |
4690 | } | |
4691 | } | |
4692 | ||
4693 | /* At this point all elements in the repeated factor vector have a | |
4694 | remaining occurrence count of 0 or 1, and those with a count of 1 | |
4695 | don't have cached representatives. Re-sort the ops vector and | |
4696 | clean up. */ | |
4697 | ops->qsort (sort_by_operand_rank); | |
4698 | repeat_factor_vec.release (); | |
4699 | ||
4700 | /* Return the final product computed herein. Note that there may | |
4701 | still be some elements with single occurrence count left in OPS; | |
4702 | those will be handled by the normal reassociation logic. */ | |
4703 | return result; | |
4704 | } | |
4705 | ||
4706 | /* Transform STMT at *GSI into a copy by replacing its rhs with NEW_RHS. */ | |
4707 | ||
4708 | static void | |
4709 | transform_stmt_to_copy (gimple_stmt_iterator *gsi, gimple stmt, tree new_rhs) | |
4710 | { | |
4711 | tree rhs1; | |
4712 | ||
4713 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4714 | { | |
4715 | fprintf (dump_file, "Transforming "); | |
4716 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
4717 | } | |
4718 | ||
4719 | rhs1 = gimple_assign_rhs1 (stmt); | |
4720 | gimple_assign_set_rhs_from_tree (gsi, new_rhs); | |
4721 | update_stmt (stmt); | |
4722 | remove_visited_stmt_chain (rhs1); | |
4723 | ||
4724 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4725 | { | |
4726 | fprintf (dump_file, " into "); | |
4727 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
4728 | } | |
4729 | } | |
4730 | ||
4731 | /* Transform STMT at *GSI into a multiply of RHS1 and RHS2. */ | |
4732 | ||
4733 | static void | |
4734 | transform_stmt_to_multiply (gimple_stmt_iterator *gsi, gimple stmt, | |
4735 | tree rhs1, tree rhs2) | |
4736 | { | |
4737 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4738 | { | |
4739 | fprintf (dump_file, "Transforming "); | |
4740 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
4741 | } | |
4742 | ||
4743 | gimple_assign_set_rhs_with_ops (gsi, MULT_EXPR, rhs1, rhs2); | |
4744 | update_stmt (gsi_stmt (*gsi)); | |
4745 | remove_visited_stmt_chain (rhs1); | |
4746 | ||
4747 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4748 | { | |
4749 | fprintf (dump_file, " into "); | |
4750 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
4751 | } | |
4752 | } | |
4753 | ||
4754 | /* Reassociate expressions in basic block BB and its post-dominator as | |
4755 | children. */ | |
4756 | ||
4757 | static void | |
4758 | reassociate_bb (basic_block bb) | |
4759 | { | |
4760 | gimple_stmt_iterator gsi; | |
4761 | basic_block son; | |
4762 | gimple stmt = last_stmt (bb); | |
4763 | ||
4764 | if (stmt && !gimple_visited_p (stmt)) | |
4765 | maybe_optimize_range_tests (stmt); | |
4766 | ||
4767 | for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi)) | |
4768 | { | |
4769 | stmt = gsi_stmt (gsi); | |
4770 | ||
4771 | if (is_gimple_assign (stmt) | |
4772 | && !stmt_could_throw_p (stmt)) | |
4773 | { | |
4774 | tree lhs, rhs1, rhs2; | |
4775 | enum tree_code rhs_code = gimple_assign_rhs_code (stmt); | |
4776 | ||
4777 | /* If this is not a gimple binary expression, there is | |
4778 | nothing for us to do with it. */ | |
4779 | if (get_gimple_rhs_class (rhs_code) != GIMPLE_BINARY_RHS) | |
4780 | continue; | |
4781 | ||
4782 | /* If this was part of an already processed statement, | |
4783 | we don't need to touch it again. */ | |
4784 | if (gimple_visited_p (stmt)) | |
4785 | { | |
4786 | /* This statement might have become dead because of previous | |
4787 | reassociations. */ | |
4788 | if (has_zero_uses (gimple_get_lhs (stmt))) | |
4789 | { | |
4790 | reassoc_remove_stmt (&gsi); | |
4791 | release_defs (stmt); | |
4792 | /* We might end up removing the last stmt above which | |
4793 | places the iterator to the end of the sequence. | |
4794 | Reset it to the last stmt in this case which might | |
4795 | be the end of the sequence as well if we removed | |
4796 | the last statement of the sequence. In which case | |
4797 | we need to bail out. */ | |
4798 | if (gsi_end_p (gsi)) | |
4799 | { | |
4800 | gsi = gsi_last_bb (bb); | |
4801 | if (gsi_end_p (gsi)) | |
4802 | break; | |
4803 | } | |
4804 | } | |
4805 | continue; | |
4806 | } | |
4807 | ||
4808 | lhs = gimple_assign_lhs (stmt); | |
4809 | rhs1 = gimple_assign_rhs1 (stmt); | |
4810 | rhs2 = gimple_assign_rhs2 (stmt); | |
4811 | ||
4812 | /* For non-bit or min/max operations we can't associate | |
4813 | all types. Verify that here. */ | |
4814 | if (rhs_code != BIT_IOR_EXPR | |
4815 | && rhs_code != BIT_AND_EXPR | |
4816 | && rhs_code != BIT_XOR_EXPR | |
4817 | && rhs_code != MIN_EXPR | |
4818 | && rhs_code != MAX_EXPR | |
4819 | && (!can_reassociate_p (lhs) | |
4820 | || !can_reassociate_p (rhs1) | |
4821 | || !can_reassociate_p (rhs2))) | |
4822 | continue; | |
4823 | ||
4824 | if (associative_tree_code (rhs_code)) | |
4825 | { | |
4826 | auto_vec<operand_entry_t> ops; | |
4827 | tree powi_result = NULL_TREE; | |
4828 | ||
4829 | /* There may be no immediate uses left by the time we | |
4830 | get here because we may have eliminated them all. */ | |
4831 | if (TREE_CODE (lhs) == SSA_NAME && has_zero_uses (lhs)) | |
4832 | continue; | |
4833 | ||
4834 | gimple_set_visited (stmt, true); | |
4835 | linearize_expr_tree (&ops, stmt, true, true); | |
4836 | ops.qsort (sort_by_operand_rank); | |
4837 | optimize_ops_list (rhs_code, &ops); | |
4838 | if (undistribute_ops_list (rhs_code, &ops, | |
4839 | loop_containing_stmt (stmt))) | |
4840 | { | |
4841 | ops.qsort (sort_by_operand_rank); | |
4842 | optimize_ops_list (rhs_code, &ops); | |
4843 | } | |
4844 | ||
4845 | if (rhs_code == BIT_IOR_EXPR || rhs_code == BIT_AND_EXPR) | |
4846 | optimize_range_tests (rhs_code, &ops); | |
4847 | ||
4848 | if (first_pass_instance | |
4849 | && rhs_code == MULT_EXPR | |
4850 | && flag_unsafe_math_optimizations) | |
4851 | powi_result = attempt_builtin_powi (stmt, &ops); | |
4852 | ||
4853 | /* If the operand vector is now empty, all operands were | |
4854 | consumed by the __builtin_powi optimization. */ | |
4855 | if (ops.length () == 0) | |
4856 | transform_stmt_to_copy (&gsi, stmt, powi_result); | |
4857 | else if (ops.length () == 1) | |
4858 | { | |
4859 | tree last_op = ops.last ()->op; | |
4860 | ||
4861 | if (powi_result) | |
4862 | transform_stmt_to_multiply (&gsi, stmt, last_op, | |
4863 | powi_result); | |
4864 | else | |
4865 | transform_stmt_to_copy (&gsi, stmt, last_op); | |
4866 | } | |
4867 | else | |
4868 | { | |
4869 | machine_mode mode = TYPE_MODE (TREE_TYPE (lhs)); | |
4870 | int ops_num = ops.length (); | |
4871 | int width = get_reassociation_width (ops_num, rhs_code, mode); | |
4872 | tree new_lhs = lhs; | |
4873 | ||
4874 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4875 | fprintf (dump_file, | |
4876 | "Width = %d was chosen for reassociation\n", width); | |
4877 | ||
4878 | if (width > 1 | |
4879 | && ops.length () > 3) | |
4880 | rewrite_expr_tree_parallel (as_a <gassign *> (stmt), | |
4881 | width, ops); | |
4882 | else | |
4883 | { | |
4884 | /* When there are three operands left, we want | |
4885 | to make sure the ones that get the double | |
4886 | binary op are chosen wisely. */ | |
4887 | int len = ops.length (); | |
4888 | if (len >= 3) | |
4889 | swap_ops_for_binary_stmt (ops, len - 3, stmt); | |
4890 | ||
4891 | new_lhs = rewrite_expr_tree (stmt, 0, ops, | |
4892 | powi_result != NULL); | |
4893 | } | |
4894 | ||
4895 | /* If we combined some repeated factors into a | |
4896 | __builtin_powi call, multiply that result by the | |
4897 | reassociated operands. */ | |
4898 | if (powi_result) | |
4899 | { | |
4900 | gimple mul_stmt, lhs_stmt = SSA_NAME_DEF_STMT (lhs); | |
4901 | tree type = TREE_TYPE (lhs); | |
4902 | tree target_ssa = make_temp_ssa_name (type, NULL, | |
4903 | "reassocpow"); | |
4904 | gimple_set_lhs (lhs_stmt, target_ssa); | |
4905 | update_stmt (lhs_stmt); | |
4906 | if (lhs != new_lhs) | |
4907 | target_ssa = new_lhs; | |
4908 | mul_stmt = gimple_build_assign (lhs, MULT_EXPR, | |
4909 | powi_result, target_ssa); | |
4910 | gimple_set_location (mul_stmt, gimple_location (stmt)); | |
7d4d0543 | 4911 | gimple_set_uid (mul_stmt, gimple_uid (stmt)); |
dda118e3 JM |
4912 | gsi_insert_after (&gsi, mul_stmt, GSI_NEW_STMT); |
4913 | } | |
4914 | } | |
4915 | } | |
4916 | } | |
4917 | } | |
4918 | for (son = first_dom_son (CDI_POST_DOMINATORS, bb); | |
4919 | son; | |
4920 | son = next_dom_son (CDI_POST_DOMINATORS, son)) | |
4921 | reassociate_bb (son); | |
4922 | } | |
4923 | ||
4924 | /* Add jumps around shifts for range tests turned into bit tests. | |
4925 | For each SSA_NAME VAR we have code like: | |
4926 | VAR = ...; // final stmt of range comparison | |
4927 | // bit test here...; | |
4928 | OTHERVAR = ...; // final stmt of the bit test sequence | |
4929 | RES = VAR | OTHERVAR; | |
4930 | Turn the above into: | |
4931 | VAR = ...; | |
4932 | if (VAR != 0) | |
4933 | goto <l3>; | |
4934 | else | |
4935 | goto <l2>; | |
4936 | <l2>: | |
4937 | // bit test here...; | |
4938 | OTHERVAR = ...; | |
4939 | <l3>: | |
4940 | # RES = PHI<1(l1), OTHERVAR(l2)>; */ | |
4941 | ||
4942 | static void | |
4943 | branch_fixup (void) | |
4944 | { | |
4945 | tree var; | |
4946 | unsigned int i; | |
4947 | ||
4948 | FOR_EACH_VEC_ELT (reassoc_branch_fixups, i, var) | |
4949 | { | |
4950 | gimple def_stmt = SSA_NAME_DEF_STMT (var); | |
4951 | gimple use_stmt; | |
4952 | use_operand_p use; | |
4953 | bool ok = single_imm_use (var, &use, &use_stmt); | |
4954 | gcc_assert (ok | |
4955 | && is_gimple_assign (use_stmt) | |
4956 | && gimple_assign_rhs_code (use_stmt) == BIT_IOR_EXPR | |
4957 | && gimple_bb (def_stmt) == gimple_bb (use_stmt)); | |
4958 | ||
4959 | basic_block cond_bb = gimple_bb (def_stmt); | |
4960 | basic_block then_bb = split_block (cond_bb, def_stmt)->dest; | |
4961 | basic_block merge_bb = split_block (then_bb, use_stmt)->dest; | |
4962 | ||
4963 | gimple_stmt_iterator gsi = gsi_for_stmt (def_stmt); | |
4964 | gimple g = gimple_build_cond (NE_EXPR, var, | |
4965 | build_zero_cst (TREE_TYPE (var)), | |
4966 | NULL_TREE, NULL_TREE); | |
4967 | location_t loc = gimple_location (use_stmt); | |
4968 | gimple_set_location (g, loc); | |
4969 | gsi_insert_after (&gsi, g, GSI_NEW_STMT); | |
4970 | ||
4971 | edge etrue = make_edge (cond_bb, merge_bb, EDGE_TRUE_VALUE); | |
4972 | etrue->probability = REG_BR_PROB_BASE / 2; | |
4973 | etrue->count = cond_bb->count / 2; | |
4974 | edge efalse = find_edge (cond_bb, then_bb); | |
4975 | efalse->flags = EDGE_FALSE_VALUE; | |
4976 | efalse->probability -= etrue->probability; | |
4977 | efalse->count -= etrue->count; | |
4978 | then_bb->count -= etrue->count; | |
4979 | ||
4980 | tree othervar = NULL_TREE; | |
4981 | if (gimple_assign_rhs1 (use_stmt) == var) | |
4982 | othervar = gimple_assign_rhs2 (use_stmt); | |
4983 | else if (gimple_assign_rhs2 (use_stmt) == var) | |
4984 | othervar = gimple_assign_rhs1 (use_stmt); | |
4985 | else | |
4986 | gcc_unreachable (); | |
4987 | tree lhs = gimple_assign_lhs (use_stmt); | |
4988 | gphi *phi = create_phi_node (lhs, merge_bb); | |
4989 | add_phi_arg (phi, build_one_cst (TREE_TYPE (lhs)), etrue, loc); | |
4990 | add_phi_arg (phi, othervar, single_succ_edge (then_bb), loc); | |
4991 | gsi = gsi_for_stmt (use_stmt); | |
4992 | gsi_remove (&gsi, true); | |
4993 | ||
4994 | set_immediate_dominator (CDI_DOMINATORS, merge_bb, cond_bb); | |
4995 | set_immediate_dominator (CDI_POST_DOMINATORS, cond_bb, merge_bb); | |
4996 | } | |
4997 | reassoc_branch_fixups.release (); | |
4998 | } | |
4999 | ||
5000 | void dump_ops_vector (FILE *file, vec<operand_entry_t> ops); | |
5001 | void debug_ops_vector (vec<operand_entry_t> ops); | |
5002 | ||
5003 | /* Dump the operand entry vector OPS to FILE. */ | |
5004 | ||
5005 | void | |
5006 | dump_ops_vector (FILE *file, vec<operand_entry_t> ops) | |
5007 | { | |
5008 | operand_entry_t oe; | |
5009 | unsigned int i; | |
5010 | ||
5011 | FOR_EACH_VEC_ELT (ops, i, oe) | |
5012 | { | |
5013 | fprintf (file, "Op %d -> rank: %d, tree: ", i, oe->rank); | |
5014 | print_generic_expr (file, oe->op, 0); | |
5015 | } | |
5016 | } | |
5017 | ||
5018 | /* Dump the operand entry vector OPS to STDERR. */ | |
5019 | ||
5020 | DEBUG_FUNCTION void | |
5021 | debug_ops_vector (vec<operand_entry_t> ops) | |
5022 | { | |
5023 | dump_ops_vector (stderr, ops); | |
5024 | } | |
5025 | ||
5026 | static void | |
5027 | do_reassoc (void) | |
5028 | { | |
5029 | break_up_subtract_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
5030 | reassociate_bb (EXIT_BLOCK_PTR_FOR_FN (cfun)); | |
5031 | } | |
5032 | ||
5033 | /* Initialize the reassociation pass. */ | |
5034 | ||
5035 | static void | |
5036 | init_reassoc (void) | |
5037 | { | |
5038 | int i; | |
5039 | long rank = 2; | |
5040 | int *bbs = XNEWVEC (int, n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS); | |
5041 | ||
5042 | /* Find the loops, so that we can prevent moving calculations in | |
5043 | them. */ | |
5044 | loop_optimizer_init (AVOID_CFG_MODIFICATIONS); | |
5045 | ||
5046 | memset (&reassociate_stats, 0, sizeof (reassociate_stats)); | |
5047 | ||
5048 | operand_entry_pool = create_alloc_pool ("operand entry pool", | |
5049 | sizeof (struct operand_entry), 30); | |
5050 | next_operand_entry_id = 0; | |
5051 | ||
5052 | /* Reverse RPO (Reverse Post Order) will give us something where | |
5053 | deeper loops come later. */ | |
5054 | pre_and_rev_post_order_compute (NULL, bbs, false); | |
5055 | bb_rank = XCNEWVEC (long, last_basic_block_for_fn (cfun)); | |
5056 | operand_rank = new hash_map<tree, long>; | |
5057 | ||
5058 | /* Give each default definition a distinct rank. This includes | |
5059 | parameters and the static chain. Walk backwards over all | |
5060 | SSA names so that we get proper rank ordering according | |
5061 | to tree_swap_operands_p. */ | |
5062 | for (i = num_ssa_names - 1; i > 0; --i) | |
5063 | { | |
5064 | tree name = ssa_name (i); | |
5065 | if (name && SSA_NAME_IS_DEFAULT_DEF (name)) | |
5066 | insert_operand_rank (name, ++rank); | |
5067 | } | |
5068 | ||
5069 | /* Set up rank for each BB */ | |
5070 | for (i = 0; i < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; i++) | |
5071 | bb_rank[bbs[i]] = ++rank << 16; | |
5072 | ||
5073 | free (bbs); | |
5074 | calculate_dominance_info (CDI_POST_DOMINATORS); | |
5075 | plus_negates = vNULL; | |
5076 | } | |
5077 | ||
5078 | /* Cleanup after the reassociation pass, and print stats if | |
5079 | requested. */ | |
5080 | ||
5081 | static void | |
5082 | fini_reassoc (void) | |
5083 | { | |
5084 | statistics_counter_event (cfun, "Linearized", | |
5085 | reassociate_stats.linearized); | |
5086 | statistics_counter_event (cfun, "Constants eliminated", | |
5087 | reassociate_stats.constants_eliminated); | |
5088 | statistics_counter_event (cfun, "Ops eliminated", | |
5089 | reassociate_stats.ops_eliminated); | |
5090 | statistics_counter_event (cfun, "Statements rewritten", | |
5091 | reassociate_stats.rewritten); | |
5092 | statistics_counter_event (cfun, "Built-in pow[i] calls encountered", | |
5093 | reassociate_stats.pows_encountered); | |
5094 | statistics_counter_event (cfun, "Built-in powi calls created", | |
5095 | reassociate_stats.pows_created); | |
5096 | ||
5097 | delete operand_rank; | |
5098 | free_alloc_pool (operand_entry_pool); | |
5099 | free (bb_rank); | |
5100 | plus_negates.release (); | |
5101 | free_dominance_info (CDI_POST_DOMINATORS); | |
5102 | loop_optimizer_finalize (); | |
5103 | } | |
5104 | ||
5105 | /* Gate and execute functions for Reassociation. */ | |
5106 | ||
5107 | static unsigned int | |
5108 | execute_reassoc (void) | |
5109 | { | |
5110 | init_reassoc (); | |
5111 | ||
5112 | do_reassoc (); | |
5113 | repropagate_negates (); | |
5114 | branch_fixup (); | |
5115 | ||
5116 | fini_reassoc (); | |
5117 | return 0; | |
5118 | } | |
5119 | ||
5120 | namespace { | |
5121 | ||
5122 | const pass_data pass_data_reassoc = | |
5123 | { | |
5124 | GIMPLE_PASS, /* type */ | |
5125 | "reassoc", /* name */ | |
5126 | OPTGROUP_NONE, /* optinfo_flags */ | |
5127 | TV_TREE_REASSOC, /* tv_id */ | |
5128 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
5129 | 0, /* properties_provided */ | |
5130 | 0, /* properties_destroyed */ | |
5131 | 0, /* todo_flags_start */ | |
5132 | TODO_update_ssa_only_virtuals, /* todo_flags_finish */ | |
5133 | }; | |
5134 | ||
5135 | class pass_reassoc : public gimple_opt_pass | |
5136 | { | |
5137 | public: | |
5138 | pass_reassoc (gcc::context *ctxt) | |
5139 | : gimple_opt_pass (pass_data_reassoc, ctxt) | |
5140 | {} | |
5141 | ||
5142 | /* opt_pass methods: */ | |
5143 | opt_pass * clone () { return new pass_reassoc (m_ctxt); } | |
5144 | virtual bool gate (function *) { return flag_tree_reassoc != 0; } | |
5145 | virtual unsigned int execute (function *) { return execute_reassoc (); } | |
5146 | ||
5147 | }; // class pass_reassoc | |
5148 | ||
5149 | } // anon namespace | |
5150 | ||
5151 | gimple_opt_pass * | |
5152 | make_pass_reassoc (gcc::context *ctxt) | |
5153 | { | |
5154 | return new pass_reassoc (ctxt); | |
5155 | } |