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1 | /* Forward propagation of expressions for single use variables. | |
2 | Copyright (C) 2004-2017 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 3, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GCC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GCC; see the file COPYING3. If not see | |
18 | <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
23 | #include "backend.h" | |
24 | #include "rtl.h" | |
25 | #include "tree.h" | |
26 | #include "gimple.h" | |
27 | #include "cfghooks.h" | |
28 | #include "tree-pass.h" | |
29 | #include "ssa.h" | |
30 | #include "expmed.h" | |
31 | #include "optabs-query.h" | |
32 | #include "gimple-pretty-print.h" | |
33 | #include "fold-const.h" | |
34 | #include "stor-layout.h" | |
35 | #include "gimple-fold.h" | |
36 | #include "tree-eh.h" | |
37 | #include "gimplify.h" | |
38 | #include "gimple-iterator.h" | |
39 | #include "gimplify-me.h" | |
40 | #include "tree-cfg.h" | |
41 | #include "expr.h" | |
42 | #include "tree-dfa.h" | |
43 | #include "tree-ssa-propagate.h" | |
44 | #include "tree-ssa-dom.h" | |
45 | #include "builtins.h" | |
46 | #include "tree-cfgcleanup.h" | |
47 | #include "cfganal.h" | |
48 | #include "optabs-tree.h" | |
49 | ||
50 | /* This pass propagates the RHS of assignment statements into use | |
51 | sites of the LHS of the assignment. It's basically a specialized | |
52 | form of tree combination. It is hoped all of this can disappear | |
53 | when we have a generalized tree combiner. | |
54 | ||
55 | One class of common cases we handle is forward propagating a single use | |
56 | variable into a COND_EXPR. | |
57 | ||
58 | bb0: | |
59 | x = a COND b; | |
60 | if (x) goto ... else goto ... | |
61 | ||
62 | Will be transformed into: | |
63 | ||
64 | bb0: | |
65 | if (a COND b) goto ... else goto ... | |
66 | ||
67 | Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1). | |
68 | ||
69 | Or (assuming c1 and c2 are constants): | |
70 | ||
71 | bb0: | |
72 | x = a + c1; | |
73 | if (x EQ/NEQ c2) goto ... else goto ... | |
74 | ||
75 | Will be transformed into: | |
76 | ||
77 | bb0: | |
78 | if (a EQ/NEQ (c2 - c1)) goto ... else goto ... | |
79 | ||
80 | Similarly for x = a - c1. | |
81 | ||
82 | Or | |
83 | ||
84 | bb0: | |
85 | x = !a | |
86 | if (x) goto ... else goto ... | |
87 | ||
88 | Will be transformed into: | |
89 | ||
90 | bb0: | |
91 | if (a == 0) goto ... else goto ... | |
92 | ||
93 | Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1). | |
94 | For these cases, we propagate A into all, possibly more than one, | |
95 | COND_EXPRs that use X. | |
96 | ||
97 | Or | |
98 | ||
99 | bb0: | |
100 | x = (typecast) a | |
101 | if (x) goto ... else goto ... | |
102 | ||
103 | Will be transformed into: | |
104 | ||
105 | bb0: | |
106 | if (a != 0) goto ... else goto ... | |
107 | ||
108 | (Assuming a is an integral type and x is a boolean or x is an | |
109 | integral and a is a boolean.) | |
110 | ||
111 | Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1). | |
112 | For these cases, we propagate A into all, possibly more than one, | |
113 | COND_EXPRs that use X. | |
114 | ||
115 | In addition to eliminating the variable and the statement which assigns | |
116 | a value to the variable, we may be able to later thread the jump without | |
117 | adding insane complexity in the dominator optimizer. | |
118 | ||
119 | Also note these transformations can cascade. We handle this by having | |
120 | a worklist of COND_EXPR statements to examine. As we make a change to | |
121 | a statement, we put it back on the worklist to examine on the next | |
122 | iteration of the main loop. | |
123 | ||
124 | A second class of propagation opportunities arises for ADDR_EXPR | |
125 | nodes. | |
126 | ||
127 | ptr = &x->y->z; | |
128 | res = *ptr; | |
129 | ||
130 | Will get turned into | |
131 | ||
132 | res = x->y->z; | |
133 | ||
134 | Or | |
135 | ptr = (type1*)&type2var; | |
136 | res = *ptr | |
137 | ||
138 | Will get turned into (if type1 and type2 are the same size | |
139 | and neither have volatile on them): | |
140 | res = VIEW_CONVERT_EXPR<type1>(type2var) | |
141 | ||
142 | Or | |
143 | ||
144 | ptr = &x[0]; | |
145 | ptr2 = ptr + <constant>; | |
146 | ||
147 | Will get turned into | |
148 | ||
149 | ptr2 = &x[constant/elementsize]; | |
150 | ||
151 | Or | |
152 | ||
153 | ptr = &x[0]; | |
154 | offset = index * element_size; | |
155 | offset_p = (pointer) offset; | |
156 | ptr2 = ptr + offset_p | |
157 | ||
158 | Will get turned into: | |
159 | ||
160 | ptr2 = &x[index]; | |
161 | ||
162 | Or | |
163 | ssa = (int) decl | |
164 | res = ssa & 1 | |
165 | ||
166 | Provided that decl has known alignment >= 2, will get turned into | |
167 | ||
168 | res = 0 | |
169 | ||
170 | We also propagate casts into SWITCH_EXPR and COND_EXPR conditions to | |
171 | allow us to remove the cast and {NOT_EXPR,NEG_EXPR} into a subsequent | |
172 | {NOT_EXPR,NEG_EXPR}. | |
173 | ||
174 | This will (of course) be extended as other needs arise. */ | |
175 | ||
176 | static bool forward_propagate_addr_expr (tree, tree, bool); | |
177 | ||
178 | /* Set to true if we delete dead edges during the optimization. */ | |
179 | static bool cfg_changed; | |
180 | ||
181 | static tree rhs_to_tree (tree type, gimple *stmt); | |
182 | ||
183 | static bitmap to_purge; | |
184 | ||
185 | /* Const-and-copy lattice. */ | |
186 | static vec<tree> lattice; | |
187 | ||
188 | /* Set the lattice entry for NAME to VAL. */ | |
189 | static void | |
190 | fwprop_set_lattice_val (tree name, tree val) | |
191 | { | |
192 | if (TREE_CODE (name) == SSA_NAME) | |
193 | { | |
194 | if (SSA_NAME_VERSION (name) >= lattice.length ()) | |
195 | { | |
196 | lattice.reserve (num_ssa_names - lattice.length ()); | |
197 | lattice.quick_grow_cleared (num_ssa_names); | |
198 | } | |
199 | lattice[SSA_NAME_VERSION (name)] = val; | |
200 | } | |
201 | } | |
202 | ||
203 | /* Invalidate the lattice entry for NAME, done when releasing SSA names. */ | |
204 | static void | |
205 | fwprop_invalidate_lattice (tree name) | |
206 | { | |
207 | if (name | |
208 | && TREE_CODE (name) == SSA_NAME | |
209 | && SSA_NAME_VERSION (name) < lattice.length ()) | |
210 | lattice[SSA_NAME_VERSION (name)] = NULL_TREE; | |
211 | } | |
212 | ||
213 | ||
214 | /* Get the statement we can propagate from into NAME skipping | |
215 | trivial copies. Returns the statement which defines the | |
216 | propagation source or NULL_TREE if there is no such one. | |
217 | If SINGLE_USE_ONLY is set considers only sources which have | |
218 | a single use chain up to NAME. If SINGLE_USE_P is non-null, | |
219 | it is set to whether the chain to NAME is a single use chain | |
220 | or not. SINGLE_USE_P is not written to if SINGLE_USE_ONLY is set. */ | |
221 | ||
222 | static gimple * | |
223 | get_prop_source_stmt (tree name, bool single_use_only, bool *single_use_p) | |
224 | { | |
225 | bool single_use = true; | |
226 | ||
227 | do { | |
228 | gimple *def_stmt = SSA_NAME_DEF_STMT (name); | |
229 | ||
230 | if (!has_single_use (name)) | |
231 | { | |
232 | single_use = false; | |
233 | if (single_use_only) | |
234 | return NULL; | |
235 | } | |
236 | ||
237 | /* If name is defined by a PHI node or is the default def, bail out. */ | |
238 | if (!is_gimple_assign (def_stmt)) | |
239 | return NULL; | |
240 | ||
241 | /* If def_stmt is a simple copy, continue looking. */ | |
242 | if (gimple_assign_rhs_code (def_stmt) == SSA_NAME) | |
243 | name = gimple_assign_rhs1 (def_stmt); | |
244 | else | |
245 | { | |
246 | if (!single_use_only && single_use_p) | |
247 | *single_use_p = single_use; | |
248 | ||
249 | return def_stmt; | |
250 | } | |
251 | } while (1); | |
252 | } | |
253 | ||
254 | /* Checks if the destination ssa name in DEF_STMT can be used as | |
255 | propagation source. Returns true if so, otherwise false. */ | |
256 | ||
257 | static bool | |
258 | can_propagate_from (gimple *def_stmt) | |
259 | { | |
260 | gcc_assert (is_gimple_assign (def_stmt)); | |
261 | ||
262 | /* If the rhs has side-effects we cannot propagate from it. */ | |
263 | if (gimple_has_volatile_ops (def_stmt)) | |
264 | return false; | |
265 | ||
266 | /* If the rhs is a load we cannot propagate from it. */ | |
267 | if (TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_reference | |
268 | || TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_declaration) | |
269 | return false; | |
270 | ||
271 | /* Constants can be always propagated. */ | |
272 | if (gimple_assign_single_p (def_stmt) | |
273 | && is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt))) | |
274 | return true; | |
275 | ||
276 | /* We cannot propagate ssa names that occur in abnormal phi nodes. */ | |
277 | if (stmt_references_abnormal_ssa_name (def_stmt)) | |
278 | return false; | |
279 | ||
280 | /* If the definition is a conversion of a pointer to a function type, | |
281 | then we can not apply optimizations as some targets require | |
282 | function pointers to be canonicalized and in this case this | |
283 | optimization could eliminate a necessary canonicalization. */ | |
284 | if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))) | |
285 | { | |
286 | tree rhs = gimple_assign_rhs1 (def_stmt); | |
287 | if (POINTER_TYPE_P (TREE_TYPE (rhs)) | |
288 | && TREE_CODE (TREE_TYPE (TREE_TYPE (rhs))) == FUNCTION_TYPE) | |
289 | return false; | |
290 | } | |
291 | ||
292 | return true; | |
293 | } | |
294 | ||
295 | /* Remove a chain of dead statements starting at the definition of | |
296 | NAME. The chain is linked via the first operand of the defining statements. | |
297 | If NAME was replaced in its only use then this function can be used | |
298 | to clean up dead stmts. The function handles already released SSA | |
299 | names gracefully. | |
300 | Returns true if cleanup-cfg has to run. */ | |
301 | ||
302 | static bool | |
303 | remove_prop_source_from_use (tree name) | |
304 | { | |
305 | gimple_stmt_iterator gsi; | |
306 | gimple *stmt; | |
307 | bool cfg_changed = false; | |
308 | ||
309 | do { | |
310 | basic_block bb; | |
311 | ||
312 | if (SSA_NAME_IN_FREE_LIST (name) | |
313 | || SSA_NAME_IS_DEFAULT_DEF (name) | |
314 | || !has_zero_uses (name)) | |
315 | return cfg_changed; | |
316 | ||
317 | stmt = SSA_NAME_DEF_STMT (name); | |
318 | if (gimple_code (stmt) == GIMPLE_PHI | |
319 | || gimple_has_side_effects (stmt)) | |
320 | return cfg_changed; | |
321 | ||
322 | bb = gimple_bb (stmt); | |
323 | gsi = gsi_for_stmt (stmt); | |
324 | unlink_stmt_vdef (stmt); | |
325 | if (gsi_remove (&gsi, true)) | |
326 | bitmap_set_bit (to_purge, bb->index); | |
327 | fwprop_invalidate_lattice (gimple_get_lhs (stmt)); | |
328 | release_defs (stmt); | |
329 | ||
330 | name = is_gimple_assign (stmt) ? gimple_assign_rhs1 (stmt) : NULL_TREE; | |
331 | } while (name && TREE_CODE (name) == SSA_NAME); | |
332 | ||
333 | return cfg_changed; | |
334 | } | |
335 | ||
336 | /* Return the rhs of a gassign *STMT in a form of a single tree, | |
337 | converted to type TYPE. | |
338 | ||
339 | This should disappear, but is needed so we can combine expressions and use | |
340 | the fold() interfaces. Long term, we need to develop folding and combine | |
341 | routines that deal with gimple exclusively . */ | |
342 | ||
343 | static tree | |
344 | rhs_to_tree (tree type, gimple *stmt) | |
345 | { | |
346 | location_t loc = gimple_location (stmt); | |
347 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
348 | if (get_gimple_rhs_class (code) == GIMPLE_TERNARY_RHS) | |
349 | return fold_build3_loc (loc, code, type, gimple_assign_rhs1 (stmt), | |
350 | gimple_assign_rhs2 (stmt), | |
351 | gimple_assign_rhs3 (stmt)); | |
352 | else if (get_gimple_rhs_class (code) == GIMPLE_BINARY_RHS) | |
353 | return fold_build2_loc (loc, code, type, gimple_assign_rhs1 (stmt), | |
354 | gimple_assign_rhs2 (stmt)); | |
355 | else if (get_gimple_rhs_class (code) == GIMPLE_UNARY_RHS) | |
356 | return build1 (code, type, gimple_assign_rhs1 (stmt)); | |
357 | else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS) | |
358 | return gimple_assign_rhs1 (stmt); | |
359 | else | |
360 | gcc_unreachable (); | |
361 | } | |
362 | ||
363 | /* Combine OP0 CODE OP1 in the context of a COND_EXPR. Returns | |
364 | the folded result in a form suitable for COND_EXPR_COND or | |
365 | NULL_TREE, if there is no suitable simplified form. If | |
366 | INVARIANT_ONLY is true only gimple_min_invariant results are | |
367 | considered simplified. */ | |
368 | ||
369 | static tree | |
370 | combine_cond_expr_cond (gimple *stmt, enum tree_code code, tree type, | |
371 | tree op0, tree op1, bool invariant_only) | |
372 | { | |
373 | tree t; | |
374 | ||
375 | gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison); | |
376 | ||
377 | fold_defer_overflow_warnings (); | |
378 | t = fold_binary_loc (gimple_location (stmt), code, type, op0, op1); | |
379 | if (!t) | |
380 | { | |
381 | fold_undefer_overflow_warnings (false, NULL, 0); | |
382 | return NULL_TREE; | |
383 | } | |
384 | ||
385 | /* Require that we got a boolean type out if we put one in. */ | |
386 | gcc_assert (TREE_CODE (TREE_TYPE (t)) == TREE_CODE (type)); | |
387 | ||
388 | /* Canonicalize the combined condition for use in a COND_EXPR. */ | |
389 | t = canonicalize_cond_expr_cond (t); | |
390 | ||
391 | /* Bail out if we required an invariant but didn't get one. */ | |
392 | if (!t || (invariant_only && !is_gimple_min_invariant (t))) | |
393 | { | |
394 | fold_undefer_overflow_warnings (false, NULL, 0); | |
395 | return NULL_TREE; | |
396 | } | |
397 | ||
398 | fold_undefer_overflow_warnings (!gimple_no_warning_p (stmt), stmt, 0); | |
399 | ||
400 | return t; | |
401 | } | |
402 | ||
403 | /* Combine the comparison OP0 CODE OP1 at LOC with the defining statements | |
404 | of its operand. Return a new comparison tree or NULL_TREE if there | |
405 | were no simplifying combines. */ | |
406 | ||
407 | static tree | |
408 | forward_propagate_into_comparison_1 (gimple *stmt, | |
409 | enum tree_code code, tree type, | |
410 | tree op0, tree op1) | |
411 | { | |
412 | tree tmp = NULL_TREE; | |
413 | tree rhs0 = NULL_TREE, rhs1 = NULL_TREE; | |
414 | bool single_use0_p = false, single_use1_p = false; | |
415 | ||
416 | /* For comparisons use the first operand, that is likely to | |
417 | simplify comparisons against constants. */ | |
418 | if (TREE_CODE (op0) == SSA_NAME) | |
419 | { | |
420 | gimple *def_stmt = get_prop_source_stmt (op0, false, &single_use0_p); | |
421 | if (def_stmt && can_propagate_from (def_stmt)) | |
422 | { | |
423 | enum tree_code def_code = gimple_assign_rhs_code (def_stmt); | |
424 | bool invariant_only_p = !single_use0_p; | |
425 | ||
426 | rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt); | |
427 | ||
428 | /* Always combine comparisons or conversions from booleans. */ | |
429 | if (TREE_CODE (op1) == INTEGER_CST | |
430 | && ((CONVERT_EXPR_CODE_P (def_code) | |
431 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (rhs0, 0))) | |
432 | == BOOLEAN_TYPE) | |
433 | || TREE_CODE_CLASS (def_code) == tcc_comparison)) | |
434 | invariant_only_p = false; | |
435 | ||
436 | tmp = combine_cond_expr_cond (stmt, code, type, | |
437 | rhs0, op1, invariant_only_p); | |
438 | if (tmp) | |
439 | return tmp; | |
440 | } | |
441 | } | |
442 | ||
443 | /* If that wasn't successful, try the second operand. */ | |
444 | if (TREE_CODE (op1) == SSA_NAME) | |
445 | { | |
446 | gimple *def_stmt = get_prop_source_stmt (op1, false, &single_use1_p); | |
447 | if (def_stmt && can_propagate_from (def_stmt)) | |
448 | { | |
449 | rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt); | |
450 | tmp = combine_cond_expr_cond (stmt, code, type, | |
451 | op0, rhs1, !single_use1_p); | |
452 | if (tmp) | |
453 | return tmp; | |
454 | } | |
455 | } | |
456 | ||
457 | /* If that wasn't successful either, try both operands. */ | |
458 | if (rhs0 != NULL_TREE | |
459 | && rhs1 != NULL_TREE) | |
460 | tmp = combine_cond_expr_cond (stmt, code, type, | |
461 | rhs0, rhs1, | |
462 | !(single_use0_p && single_use1_p)); | |
463 | ||
464 | return tmp; | |
465 | } | |
466 | ||
467 | /* Propagate from the ssa name definition statements of the assignment | |
468 | from a comparison at *GSI into the conditional if that simplifies it. | |
469 | Returns 1 if the stmt was modified and 2 if the CFG needs cleanup, | |
470 | otherwise returns 0. */ | |
471 | ||
472 | static int | |
473 | forward_propagate_into_comparison (gimple_stmt_iterator *gsi) | |
474 | { | |
475 | gimple *stmt = gsi_stmt (*gsi); | |
476 | tree tmp; | |
477 | bool cfg_changed = false; | |
478 | tree type = TREE_TYPE (gimple_assign_lhs (stmt)); | |
479 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
480 | tree rhs2 = gimple_assign_rhs2 (stmt); | |
481 | ||
482 | /* Combine the comparison with defining statements. */ | |
483 | tmp = forward_propagate_into_comparison_1 (stmt, | |
484 | gimple_assign_rhs_code (stmt), | |
485 | type, rhs1, rhs2); | |
486 | if (tmp && useless_type_conversion_p (type, TREE_TYPE (tmp))) | |
487 | { | |
488 | gimple_assign_set_rhs_from_tree (gsi, tmp); | |
489 | fold_stmt (gsi); | |
490 | update_stmt (gsi_stmt (*gsi)); | |
491 | ||
492 | if (TREE_CODE (rhs1) == SSA_NAME) | |
493 | cfg_changed |= remove_prop_source_from_use (rhs1); | |
494 | if (TREE_CODE (rhs2) == SSA_NAME) | |
495 | cfg_changed |= remove_prop_source_from_use (rhs2); | |
496 | return cfg_changed ? 2 : 1; | |
497 | } | |
498 | ||
499 | return 0; | |
500 | } | |
501 | ||
502 | /* Propagate from the ssa name definition statements of COND_EXPR | |
503 | in GIMPLE_COND statement STMT into the conditional if that simplifies it. | |
504 | Returns zero if no statement was changed, one if there were | |
505 | changes and two if cfg_cleanup needs to run. | |
506 | ||
507 | This must be kept in sync with forward_propagate_into_cond. */ | |
508 | ||
509 | static int | |
510 | forward_propagate_into_gimple_cond (gcond *stmt) | |
511 | { | |
512 | tree tmp; | |
513 | enum tree_code code = gimple_cond_code (stmt); | |
514 | bool cfg_changed = false; | |
515 | tree rhs1 = gimple_cond_lhs (stmt); | |
516 | tree rhs2 = gimple_cond_rhs (stmt); | |
517 | ||
518 | /* We can do tree combining on SSA_NAME and comparison expressions. */ | |
519 | if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison) | |
520 | return 0; | |
521 | ||
522 | tmp = forward_propagate_into_comparison_1 (stmt, code, | |
523 | boolean_type_node, | |
524 | rhs1, rhs2); | |
525 | if (tmp) | |
526 | { | |
527 | if (dump_file && tmp) | |
528 | { | |
529 | fprintf (dump_file, " Replaced '"); | |
530 | print_gimple_expr (dump_file, stmt, 0, 0); | |
531 | fprintf (dump_file, "' with '"); | |
532 | print_generic_expr (dump_file, tmp, 0); | |
533 | fprintf (dump_file, "'\n"); | |
534 | } | |
535 | ||
536 | gimple_cond_set_condition_from_tree (stmt, unshare_expr (tmp)); | |
537 | update_stmt (stmt); | |
538 | ||
539 | if (TREE_CODE (rhs1) == SSA_NAME) | |
540 | cfg_changed |= remove_prop_source_from_use (rhs1); | |
541 | if (TREE_CODE (rhs2) == SSA_NAME) | |
542 | cfg_changed |= remove_prop_source_from_use (rhs2); | |
543 | return (cfg_changed || is_gimple_min_invariant (tmp)) ? 2 : 1; | |
544 | } | |
545 | ||
546 | /* Canonicalize _Bool == 0 and _Bool != 1 to _Bool != 0 by swapping edges. */ | |
547 | if ((TREE_CODE (TREE_TYPE (rhs1)) == BOOLEAN_TYPE | |
548 | || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
549 | && TYPE_PRECISION (TREE_TYPE (rhs1)) == 1)) | |
550 | && ((code == EQ_EXPR | |
551 | && integer_zerop (rhs2)) | |
552 | || (code == NE_EXPR | |
553 | && integer_onep (rhs2)))) | |
554 | { | |
555 | basic_block bb = gimple_bb (stmt); | |
556 | gimple_cond_set_code (stmt, NE_EXPR); | |
557 | gimple_cond_set_rhs (stmt, build_zero_cst (TREE_TYPE (rhs1))); | |
558 | EDGE_SUCC (bb, 0)->flags ^= (EDGE_TRUE_VALUE|EDGE_FALSE_VALUE); | |
559 | EDGE_SUCC (bb, 1)->flags ^= (EDGE_TRUE_VALUE|EDGE_FALSE_VALUE); | |
560 | return 1; | |
561 | } | |
562 | ||
563 | return 0; | |
564 | } | |
565 | ||
566 | ||
567 | /* Propagate from the ssa name definition statements of COND_EXPR | |
568 | in the rhs of statement STMT into the conditional if that simplifies it. | |
569 | Returns true zero if the stmt was changed. */ | |
570 | ||
571 | static bool | |
572 | forward_propagate_into_cond (gimple_stmt_iterator *gsi_p) | |
573 | { | |
574 | gimple *stmt = gsi_stmt (*gsi_p); | |
575 | tree tmp = NULL_TREE; | |
576 | tree cond = gimple_assign_rhs1 (stmt); | |
577 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
578 | ||
579 | /* We can do tree combining on SSA_NAME and comparison expressions. */ | |
580 | if (COMPARISON_CLASS_P (cond)) | |
581 | tmp = forward_propagate_into_comparison_1 (stmt, TREE_CODE (cond), | |
582 | TREE_TYPE (cond), | |
583 | TREE_OPERAND (cond, 0), | |
584 | TREE_OPERAND (cond, 1)); | |
585 | else if (TREE_CODE (cond) == SSA_NAME) | |
586 | { | |
587 | enum tree_code def_code; | |
588 | tree name = cond; | |
589 | gimple *def_stmt = get_prop_source_stmt (name, true, NULL); | |
590 | if (!def_stmt || !can_propagate_from (def_stmt)) | |
591 | return 0; | |
592 | ||
593 | def_code = gimple_assign_rhs_code (def_stmt); | |
594 | if (TREE_CODE_CLASS (def_code) == tcc_comparison) | |
595 | tmp = fold_build2_loc (gimple_location (def_stmt), | |
596 | def_code, | |
597 | TREE_TYPE (cond), | |
598 | gimple_assign_rhs1 (def_stmt), | |
599 | gimple_assign_rhs2 (def_stmt)); | |
600 | } | |
601 | ||
602 | if (tmp | |
603 | && is_gimple_condexpr (tmp)) | |
604 | { | |
605 | if (dump_file && tmp) | |
606 | { | |
607 | fprintf (dump_file, " Replaced '"); | |
608 | print_generic_expr (dump_file, cond, 0); | |
609 | fprintf (dump_file, "' with '"); | |
610 | print_generic_expr (dump_file, tmp, 0); | |
611 | fprintf (dump_file, "'\n"); | |
612 | } | |
613 | ||
614 | if ((code == VEC_COND_EXPR) ? integer_all_onesp (tmp) | |
615 | : integer_onep (tmp)) | |
616 | gimple_assign_set_rhs_from_tree (gsi_p, gimple_assign_rhs2 (stmt)); | |
617 | else if (integer_zerop (tmp)) | |
618 | gimple_assign_set_rhs_from_tree (gsi_p, gimple_assign_rhs3 (stmt)); | |
619 | else | |
620 | gimple_assign_set_rhs1 (stmt, unshare_expr (tmp)); | |
621 | stmt = gsi_stmt (*gsi_p); | |
622 | update_stmt (stmt); | |
623 | ||
624 | return true; | |
625 | } | |
626 | ||
627 | return 0; | |
628 | } | |
629 | ||
630 | /* We've just substituted an ADDR_EXPR into stmt. Update all the | |
631 | relevant data structures to match. */ | |
632 | ||
633 | static void | |
634 | tidy_after_forward_propagate_addr (gimple *stmt) | |
635 | { | |
636 | /* We may have turned a trapping insn into a non-trapping insn. */ | |
637 | if (maybe_clean_or_replace_eh_stmt (stmt, stmt)) | |
638 | bitmap_set_bit (to_purge, gimple_bb (stmt)->index); | |
639 | ||
640 | if (TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR) | |
641 | recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt)); | |
642 | } | |
643 | ||
644 | /* NAME is a SSA_NAME representing DEF_RHS which is of the form | |
645 | ADDR_EXPR <whatever>. | |
646 | ||
647 | Try to forward propagate the ADDR_EXPR into the use USE_STMT. | |
648 | Often this will allow for removal of an ADDR_EXPR and INDIRECT_REF | |
649 | node or for recovery of array indexing from pointer arithmetic. | |
650 | ||
651 | Return true if the propagation was successful (the propagation can | |
652 | be not totally successful, yet things may have been changed). */ | |
653 | ||
654 | static bool | |
655 | forward_propagate_addr_expr_1 (tree name, tree def_rhs, | |
656 | gimple_stmt_iterator *use_stmt_gsi, | |
657 | bool single_use_p) | |
658 | { | |
659 | tree lhs, rhs, rhs2, array_ref; | |
660 | gimple *use_stmt = gsi_stmt (*use_stmt_gsi); | |
661 | enum tree_code rhs_code; | |
662 | bool res = true; | |
663 | ||
664 | gcc_assert (TREE_CODE (def_rhs) == ADDR_EXPR); | |
665 | ||
666 | lhs = gimple_assign_lhs (use_stmt); | |
667 | rhs_code = gimple_assign_rhs_code (use_stmt); | |
668 | rhs = gimple_assign_rhs1 (use_stmt); | |
669 | ||
670 | /* Do not perform copy-propagation but recurse through copy chains. */ | |
671 | if (TREE_CODE (lhs) == SSA_NAME | |
672 | && rhs_code == SSA_NAME) | |
673 | return forward_propagate_addr_expr (lhs, def_rhs, single_use_p); | |
674 | ||
675 | /* The use statement could be a conversion. Recurse to the uses of the | |
676 | lhs as copyprop does not copy through pointer to integer to pointer | |
677 | conversions and FRE does not catch all cases either. | |
678 | Treat the case of a single-use name and | |
679 | a conversion to def_rhs type separate, though. */ | |
680 | if (TREE_CODE (lhs) == SSA_NAME | |
681 | && CONVERT_EXPR_CODE_P (rhs_code)) | |
682 | { | |
683 | /* If there is a point in a conversion chain where the types match | |
684 | so we can remove a conversion re-materialize the address here | |
685 | and stop. */ | |
686 | if (single_use_p | |
687 | && useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs))) | |
688 | { | |
689 | gimple_assign_set_rhs1 (use_stmt, unshare_expr (def_rhs)); | |
690 | gimple_assign_set_rhs_code (use_stmt, TREE_CODE (def_rhs)); | |
691 | return true; | |
692 | } | |
693 | ||
694 | /* Else recurse if the conversion preserves the address value. */ | |
695 | if ((INTEGRAL_TYPE_P (TREE_TYPE (lhs)) | |
696 | || POINTER_TYPE_P (TREE_TYPE (lhs))) | |
697 | && (TYPE_PRECISION (TREE_TYPE (lhs)) | |
698 | >= TYPE_PRECISION (TREE_TYPE (def_rhs)))) | |
699 | return forward_propagate_addr_expr (lhs, def_rhs, single_use_p); | |
700 | ||
701 | return false; | |
702 | } | |
703 | ||
704 | /* If this isn't a conversion chain from this on we only can propagate | |
705 | into compatible pointer contexts. */ | |
706 | if (!types_compatible_p (TREE_TYPE (name), TREE_TYPE (def_rhs))) | |
707 | return false; | |
708 | ||
709 | /* Propagate through constant pointer adjustments. */ | |
710 | if (TREE_CODE (lhs) == SSA_NAME | |
711 | && rhs_code == POINTER_PLUS_EXPR | |
712 | && rhs == name | |
713 | && TREE_CODE (gimple_assign_rhs2 (use_stmt)) == INTEGER_CST) | |
714 | { | |
715 | tree new_def_rhs; | |
716 | /* As we come here with non-invariant addresses in def_rhs we need | |
717 | to make sure we can build a valid constant offsetted address | |
718 | for further propagation. Simply rely on fold building that | |
719 | and check after the fact. */ | |
720 | new_def_rhs = fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (rhs)), | |
721 | def_rhs, | |
722 | fold_convert (ptr_type_node, | |
723 | gimple_assign_rhs2 (use_stmt))); | |
724 | if (TREE_CODE (new_def_rhs) == MEM_REF | |
725 | && !is_gimple_mem_ref_addr (TREE_OPERAND (new_def_rhs, 0))) | |
726 | return false; | |
727 | new_def_rhs = build_fold_addr_expr_with_type (new_def_rhs, | |
728 | TREE_TYPE (rhs)); | |
729 | ||
730 | /* Recurse. If we could propagate into all uses of lhs do not | |
731 | bother to replace into the current use but just pretend we did. */ | |
732 | if (TREE_CODE (new_def_rhs) == ADDR_EXPR | |
733 | && forward_propagate_addr_expr (lhs, new_def_rhs, single_use_p)) | |
734 | return true; | |
735 | ||
736 | if (useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (new_def_rhs))) | |
737 | gimple_assign_set_rhs_with_ops (use_stmt_gsi, TREE_CODE (new_def_rhs), | |
738 | new_def_rhs); | |
739 | else if (is_gimple_min_invariant (new_def_rhs)) | |
740 | gimple_assign_set_rhs_with_ops (use_stmt_gsi, NOP_EXPR, new_def_rhs); | |
741 | else | |
742 | return false; | |
743 | gcc_assert (gsi_stmt (*use_stmt_gsi) == use_stmt); | |
744 | update_stmt (use_stmt); | |
745 | return true; | |
746 | } | |
747 | ||
748 | /* Now strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS. | |
749 | ADDR_EXPR will not appear on the LHS. */ | |
750 | tree *lhsp = gimple_assign_lhs_ptr (use_stmt); | |
751 | while (handled_component_p (*lhsp)) | |
752 | lhsp = &TREE_OPERAND (*lhsp, 0); | |
753 | lhs = *lhsp; | |
754 | ||
755 | /* Now see if the LHS node is a MEM_REF using NAME. If so, | |
756 | propagate the ADDR_EXPR into the use of NAME and fold the result. */ | |
757 | if (TREE_CODE (lhs) == MEM_REF | |
758 | && TREE_OPERAND (lhs, 0) == name) | |
759 | { | |
760 | tree def_rhs_base; | |
761 | HOST_WIDE_INT def_rhs_offset; | |
762 | /* If the address is invariant we can always fold it. */ | |
763 | if ((def_rhs_base = get_addr_base_and_unit_offset (TREE_OPERAND (def_rhs, 0), | |
764 | &def_rhs_offset))) | |
765 | { | |
766 | offset_int off = mem_ref_offset (lhs); | |
767 | tree new_ptr; | |
768 | off += def_rhs_offset; | |
769 | if (TREE_CODE (def_rhs_base) == MEM_REF) | |
770 | { | |
771 | off += mem_ref_offset (def_rhs_base); | |
772 | new_ptr = TREE_OPERAND (def_rhs_base, 0); | |
773 | } | |
774 | else | |
775 | new_ptr = build_fold_addr_expr (def_rhs_base); | |
776 | TREE_OPERAND (lhs, 0) = new_ptr; | |
777 | TREE_OPERAND (lhs, 1) | |
778 | = wide_int_to_tree (TREE_TYPE (TREE_OPERAND (lhs, 1)), off); | |
779 | tidy_after_forward_propagate_addr (use_stmt); | |
780 | /* Continue propagating into the RHS if this was not the only use. */ | |
781 | if (single_use_p) | |
782 | return true; | |
783 | } | |
784 | /* If the LHS is a plain dereference and the value type is the same as | |
785 | that of the pointed-to type of the address we can put the | |
786 | dereferenced address on the LHS preserving the original alias-type. */ | |
787 | else if (integer_zerop (TREE_OPERAND (lhs, 1)) | |
788 | && ((gimple_assign_lhs (use_stmt) == lhs | |
789 | && useless_type_conversion_p | |
790 | (TREE_TYPE (TREE_OPERAND (def_rhs, 0)), | |
791 | TREE_TYPE (gimple_assign_rhs1 (use_stmt)))) | |
792 | || types_compatible_p (TREE_TYPE (lhs), | |
793 | TREE_TYPE (TREE_OPERAND (def_rhs, 0)))) | |
794 | /* Don't forward anything into clobber stmts if it would result | |
795 | in the lhs no longer being a MEM_REF. */ | |
796 | && (!gimple_clobber_p (use_stmt) | |
797 | || TREE_CODE (TREE_OPERAND (def_rhs, 0)) == MEM_REF)) | |
798 | { | |
799 | tree *def_rhs_basep = &TREE_OPERAND (def_rhs, 0); | |
800 | tree new_offset, new_base, saved, new_lhs; | |
801 | while (handled_component_p (*def_rhs_basep)) | |
802 | def_rhs_basep = &TREE_OPERAND (*def_rhs_basep, 0); | |
803 | saved = *def_rhs_basep; | |
804 | if (TREE_CODE (*def_rhs_basep) == MEM_REF) | |
805 | { | |
806 | new_base = TREE_OPERAND (*def_rhs_basep, 0); | |
807 | new_offset = fold_convert (TREE_TYPE (TREE_OPERAND (lhs, 1)), | |
808 | TREE_OPERAND (*def_rhs_basep, 1)); | |
809 | } | |
810 | else | |
811 | { | |
812 | new_base = build_fold_addr_expr (*def_rhs_basep); | |
813 | new_offset = TREE_OPERAND (lhs, 1); | |
814 | } | |
815 | *def_rhs_basep = build2 (MEM_REF, TREE_TYPE (*def_rhs_basep), | |
816 | new_base, new_offset); | |
817 | TREE_THIS_VOLATILE (*def_rhs_basep) = TREE_THIS_VOLATILE (lhs); | |
818 | TREE_SIDE_EFFECTS (*def_rhs_basep) = TREE_SIDE_EFFECTS (lhs); | |
819 | TREE_THIS_NOTRAP (*def_rhs_basep) = TREE_THIS_NOTRAP (lhs); | |
820 | new_lhs = unshare_expr (TREE_OPERAND (def_rhs, 0)); | |
821 | *lhsp = new_lhs; | |
822 | TREE_THIS_VOLATILE (new_lhs) = TREE_THIS_VOLATILE (lhs); | |
823 | TREE_SIDE_EFFECTS (new_lhs) = TREE_SIDE_EFFECTS (lhs); | |
824 | *def_rhs_basep = saved; | |
825 | tidy_after_forward_propagate_addr (use_stmt); | |
826 | /* Continue propagating into the RHS if this was not the | |
827 | only use. */ | |
828 | if (single_use_p) | |
829 | return true; | |
830 | } | |
831 | else | |
832 | /* We can have a struct assignment dereferencing our name twice. | |
833 | Note that we didn't propagate into the lhs to not falsely | |
834 | claim we did when propagating into the rhs. */ | |
835 | res = false; | |
836 | } | |
837 | ||
838 | /* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR | |
839 | nodes from the RHS. */ | |
840 | tree *rhsp = gimple_assign_rhs1_ptr (use_stmt); | |
841 | if (TREE_CODE (*rhsp) == ADDR_EXPR) | |
842 | rhsp = &TREE_OPERAND (*rhsp, 0); | |
843 | while (handled_component_p (*rhsp)) | |
844 | rhsp = &TREE_OPERAND (*rhsp, 0); | |
845 | rhs = *rhsp; | |
846 | ||
847 | /* Now see if the RHS node is a MEM_REF using NAME. If so, | |
848 | propagate the ADDR_EXPR into the use of NAME and fold the result. */ | |
849 | if (TREE_CODE (rhs) == MEM_REF | |
850 | && TREE_OPERAND (rhs, 0) == name) | |
851 | { | |
852 | tree def_rhs_base; | |
853 | HOST_WIDE_INT def_rhs_offset; | |
854 | if ((def_rhs_base = get_addr_base_and_unit_offset (TREE_OPERAND (def_rhs, 0), | |
855 | &def_rhs_offset))) | |
856 | { | |
857 | offset_int off = mem_ref_offset (rhs); | |
858 | tree new_ptr; | |
859 | off += def_rhs_offset; | |
860 | if (TREE_CODE (def_rhs_base) == MEM_REF) | |
861 | { | |
862 | off += mem_ref_offset (def_rhs_base); | |
863 | new_ptr = TREE_OPERAND (def_rhs_base, 0); | |
864 | } | |
865 | else | |
866 | new_ptr = build_fold_addr_expr (def_rhs_base); | |
867 | TREE_OPERAND (rhs, 0) = new_ptr; | |
868 | TREE_OPERAND (rhs, 1) | |
869 | = wide_int_to_tree (TREE_TYPE (TREE_OPERAND (rhs, 1)), off); | |
870 | fold_stmt_inplace (use_stmt_gsi); | |
871 | tidy_after_forward_propagate_addr (use_stmt); | |
872 | return res; | |
873 | } | |
874 | /* If the RHS is a plain dereference and the value type is the same as | |
875 | that of the pointed-to type of the address we can put the | |
876 | dereferenced address on the RHS preserving the original alias-type. */ | |
877 | else if (integer_zerop (TREE_OPERAND (rhs, 1)) | |
878 | && ((gimple_assign_rhs1 (use_stmt) == rhs | |
879 | && useless_type_conversion_p | |
880 | (TREE_TYPE (gimple_assign_lhs (use_stmt)), | |
881 | TREE_TYPE (TREE_OPERAND (def_rhs, 0)))) | |
882 | || types_compatible_p (TREE_TYPE (rhs), | |
883 | TREE_TYPE (TREE_OPERAND (def_rhs, 0))))) | |
884 | { | |
885 | tree *def_rhs_basep = &TREE_OPERAND (def_rhs, 0); | |
886 | tree new_offset, new_base, saved, new_rhs; | |
887 | while (handled_component_p (*def_rhs_basep)) | |
888 | def_rhs_basep = &TREE_OPERAND (*def_rhs_basep, 0); | |
889 | saved = *def_rhs_basep; | |
890 | if (TREE_CODE (*def_rhs_basep) == MEM_REF) | |
891 | { | |
892 | new_base = TREE_OPERAND (*def_rhs_basep, 0); | |
893 | new_offset = fold_convert (TREE_TYPE (TREE_OPERAND (rhs, 1)), | |
894 | TREE_OPERAND (*def_rhs_basep, 1)); | |
895 | } | |
896 | else | |
897 | { | |
898 | new_base = build_fold_addr_expr (*def_rhs_basep); | |
899 | new_offset = TREE_OPERAND (rhs, 1); | |
900 | } | |
901 | *def_rhs_basep = build2 (MEM_REF, TREE_TYPE (*def_rhs_basep), | |
902 | new_base, new_offset); | |
903 | TREE_THIS_VOLATILE (*def_rhs_basep) = TREE_THIS_VOLATILE (rhs); | |
904 | TREE_SIDE_EFFECTS (*def_rhs_basep) = TREE_SIDE_EFFECTS (rhs); | |
905 | TREE_THIS_NOTRAP (*def_rhs_basep) = TREE_THIS_NOTRAP (rhs); | |
906 | new_rhs = unshare_expr (TREE_OPERAND (def_rhs, 0)); | |
907 | *rhsp = new_rhs; | |
908 | TREE_THIS_VOLATILE (new_rhs) = TREE_THIS_VOLATILE (rhs); | |
909 | TREE_SIDE_EFFECTS (new_rhs) = TREE_SIDE_EFFECTS (rhs); | |
910 | *def_rhs_basep = saved; | |
911 | fold_stmt_inplace (use_stmt_gsi); | |
912 | tidy_after_forward_propagate_addr (use_stmt); | |
913 | return res; | |
914 | } | |
915 | } | |
916 | ||
917 | /* If the use of the ADDR_EXPR is not a POINTER_PLUS_EXPR, there | |
918 | is nothing to do. */ | |
919 | if (gimple_assign_rhs_code (use_stmt) != POINTER_PLUS_EXPR | |
920 | || gimple_assign_rhs1 (use_stmt) != name) | |
921 | return false; | |
922 | ||
923 | /* The remaining cases are all for turning pointer arithmetic into | |
924 | array indexing. They only apply when we have the address of | |
925 | element zero in an array. If that is not the case then there | |
926 | is nothing to do. */ | |
927 | array_ref = TREE_OPERAND (def_rhs, 0); | |
928 | if ((TREE_CODE (array_ref) != ARRAY_REF | |
929 | || TREE_CODE (TREE_TYPE (TREE_OPERAND (array_ref, 0))) != ARRAY_TYPE | |
930 | || TREE_CODE (TREE_OPERAND (array_ref, 1)) != INTEGER_CST) | |
931 | && TREE_CODE (TREE_TYPE (array_ref)) != ARRAY_TYPE) | |
932 | return false; | |
933 | ||
934 | rhs2 = gimple_assign_rhs2 (use_stmt); | |
935 | /* Optimize &x[C1] p+ C2 to &x p+ C3 with C3 = C1 * element_size + C2. */ | |
936 | if (TREE_CODE (rhs2) == INTEGER_CST) | |
937 | { | |
938 | tree new_rhs = build1_loc (gimple_location (use_stmt), | |
939 | ADDR_EXPR, TREE_TYPE (def_rhs), | |
940 | fold_build2 (MEM_REF, | |
941 | TREE_TYPE (TREE_TYPE (def_rhs)), | |
942 | unshare_expr (def_rhs), | |
943 | fold_convert (ptr_type_node, | |
944 | rhs2))); | |
945 | gimple_assign_set_rhs_from_tree (use_stmt_gsi, new_rhs); | |
946 | use_stmt = gsi_stmt (*use_stmt_gsi); | |
947 | update_stmt (use_stmt); | |
948 | tidy_after_forward_propagate_addr (use_stmt); | |
949 | return true; | |
950 | } | |
951 | ||
952 | return false; | |
953 | } | |
954 | ||
955 | /* STMT is a statement of the form SSA_NAME = ADDR_EXPR <whatever>. | |
956 | ||
957 | Try to forward propagate the ADDR_EXPR into all uses of the SSA_NAME. | |
958 | Often this will allow for removal of an ADDR_EXPR and INDIRECT_REF | |
959 | node or for recovery of array indexing from pointer arithmetic. | |
960 | ||
961 | PARENT_SINGLE_USE_P tells if, when in a recursive invocation, NAME was | |
962 | the single use in the previous invocation. Pass true when calling | |
963 | this as toplevel. | |
964 | ||
965 | Returns true, if all uses have been propagated into. */ | |
966 | ||
967 | static bool | |
968 | forward_propagate_addr_expr (tree name, tree rhs, bool parent_single_use_p) | |
969 | { | |
970 | imm_use_iterator iter; | |
971 | gimple *use_stmt; | |
972 | bool all = true; | |
973 | bool single_use_p = parent_single_use_p && has_single_use (name); | |
974 | ||
975 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, name) | |
976 | { | |
977 | bool result; | |
978 | tree use_rhs; | |
979 | ||
980 | /* If the use is not in a simple assignment statement, then | |
981 | there is nothing we can do. */ | |
982 | if (!is_gimple_assign (use_stmt)) | |
983 | { | |
984 | if (!is_gimple_debug (use_stmt)) | |
985 | all = false; | |
986 | continue; | |
987 | } | |
988 | ||
989 | gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt); | |
990 | result = forward_propagate_addr_expr_1 (name, rhs, &gsi, | |
991 | single_use_p); | |
992 | /* If the use has moved to a different statement adjust | |
993 | the update machinery for the old statement too. */ | |
994 | if (use_stmt != gsi_stmt (gsi)) | |
995 | { | |
996 | update_stmt (use_stmt); | |
997 | use_stmt = gsi_stmt (gsi); | |
998 | } | |
999 | update_stmt (use_stmt); | |
1000 | all &= result; | |
1001 | ||
1002 | /* Remove intermediate now unused copy and conversion chains. */ | |
1003 | use_rhs = gimple_assign_rhs1 (use_stmt); | |
1004 | if (result | |
1005 | && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME | |
1006 | && TREE_CODE (use_rhs) == SSA_NAME | |
1007 | && has_zero_uses (gimple_assign_lhs (use_stmt))) | |
1008 | { | |
1009 | gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt); | |
1010 | fwprop_invalidate_lattice (gimple_get_lhs (use_stmt)); | |
1011 | release_defs (use_stmt); | |
1012 | gsi_remove (&gsi, true); | |
1013 | } | |
1014 | } | |
1015 | ||
1016 | return all && has_zero_uses (name); | |
1017 | } | |
1018 | ||
1019 | ||
1020 | /* Helper function for simplify_gimple_switch. Remove case labels that | |
1021 | have values outside the range of the new type. */ | |
1022 | ||
1023 | static void | |
1024 | simplify_gimple_switch_label_vec (gswitch *stmt, tree index_type) | |
1025 | { | |
1026 | unsigned int branch_num = gimple_switch_num_labels (stmt); | |
1027 | auto_vec<tree> labels (branch_num); | |
1028 | unsigned int i, len; | |
1029 | ||
1030 | /* Collect the existing case labels in a VEC, and preprocess it as if | |
1031 | we are gimplifying a GENERIC SWITCH_EXPR. */ | |
1032 | for (i = 1; i < branch_num; i++) | |
1033 | labels.quick_push (gimple_switch_label (stmt, i)); | |
1034 | preprocess_case_label_vec_for_gimple (labels, index_type, NULL); | |
1035 | ||
1036 | /* If any labels were removed, replace the existing case labels | |
1037 | in the GIMPLE_SWITCH statement with the correct ones. | |
1038 | Note that the type updates were done in-place on the case labels, | |
1039 | so we only have to replace the case labels in the GIMPLE_SWITCH | |
1040 | if the number of labels changed. */ | |
1041 | len = labels.length (); | |
1042 | if (len < branch_num - 1) | |
1043 | { | |
1044 | bitmap target_blocks; | |
1045 | edge_iterator ei; | |
1046 | edge e; | |
1047 | ||
1048 | /* Corner case: *all* case labels have been removed as being | |
1049 | out-of-range for INDEX_TYPE. Push one label and let the | |
1050 | CFG cleanups deal with this further. */ | |
1051 | if (len == 0) | |
1052 | { | |
1053 | tree label, elt; | |
1054 | ||
1055 | label = CASE_LABEL (gimple_switch_default_label (stmt)); | |
1056 | elt = build_case_label (build_int_cst (index_type, 0), NULL, label); | |
1057 | labels.quick_push (elt); | |
1058 | len = 1; | |
1059 | } | |
1060 | ||
1061 | for (i = 0; i < labels.length (); i++) | |
1062 | gimple_switch_set_label (stmt, i + 1, labels[i]); | |
1063 | for (i++ ; i < branch_num; i++) | |
1064 | gimple_switch_set_label (stmt, i, NULL_TREE); | |
1065 | gimple_switch_set_num_labels (stmt, len + 1); | |
1066 | ||
1067 | /* Cleanup any edges that are now dead. */ | |
1068 | target_blocks = BITMAP_ALLOC (NULL); | |
1069 | for (i = 0; i < gimple_switch_num_labels (stmt); i++) | |
1070 | { | |
1071 | tree elt = gimple_switch_label (stmt, i); | |
1072 | basic_block target = label_to_block (CASE_LABEL (elt)); | |
1073 | bitmap_set_bit (target_blocks, target->index); | |
1074 | } | |
1075 | for (ei = ei_start (gimple_bb (stmt)->succs); (e = ei_safe_edge (ei)); ) | |
1076 | { | |
1077 | if (! bitmap_bit_p (target_blocks, e->dest->index)) | |
1078 | { | |
1079 | remove_edge (e); | |
1080 | cfg_changed = true; | |
1081 | free_dominance_info (CDI_DOMINATORS); | |
1082 | } | |
1083 | else | |
1084 | ei_next (&ei); | |
1085 | } | |
1086 | BITMAP_FREE (target_blocks); | |
1087 | } | |
1088 | } | |
1089 | ||
1090 | /* STMT is a SWITCH_EXPR for which we attempt to find equivalent forms of | |
1091 | the condition which we may be able to optimize better. */ | |
1092 | ||
1093 | static bool | |
1094 | simplify_gimple_switch (gswitch *stmt) | |
1095 | { | |
1096 | /* The optimization that we really care about is removing unnecessary | |
1097 | casts. That will let us do much better in propagating the inferred | |
1098 | constant at the switch target. */ | |
1099 | tree cond = gimple_switch_index (stmt); | |
1100 | if (TREE_CODE (cond) == SSA_NAME) | |
1101 | { | |
1102 | gimple *def_stmt = SSA_NAME_DEF_STMT (cond); | |
1103 | if (gimple_assign_cast_p (def_stmt)) | |
1104 | { | |
1105 | tree def = gimple_assign_rhs1 (def_stmt); | |
1106 | if (TREE_CODE (def) != SSA_NAME) | |
1107 | return false; | |
1108 | ||
1109 | /* If we have an extension or sign-change that preserves the | |
1110 | values we check against then we can copy the source value into | |
1111 | the switch. */ | |
1112 | tree ti = TREE_TYPE (def); | |
1113 | if (INTEGRAL_TYPE_P (ti) | |
1114 | && TYPE_PRECISION (ti) <= TYPE_PRECISION (TREE_TYPE (cond))) | |
1115 | { | |
1116 | size_t n = gimple_switch_num_labels (stmt); | |
1117 | tree min = NULL_TREE, max = NULL_TREE; | |
1118 | if (n > 1) | |
1119 | { | |
1120 | min = CASE_LOW (gimple_switch_label (stmt, 1)); | |
1121 | if (CASE_HIGH (gimple_switch_label (stmt, n - 1))) | |
1122 | max = CASE_HIGH (gimple_switch_label (stmt, n - 1)); | |
1123 | else | |
1124 | max = CASE_LOW (gimple_switch_label (stmt, n - 1)); | |
1125 | } | |
1126 | if ((!min || int_fits_type_p (min, ti)) | |
1127 | && (!max || int_fits_type_p (max, ti))) | |
1128 | { | |
1129 | gimple_switch_set_index (stmt, def); | |
1130 | simplify_gimple_switch_label_vec (stmt, ti); | |
1131 | update_stmt (stmt); | |
1132 | return true; | |
1133 | } | |
1134 | } | |
1135 | } | |
1136 | } | |
1137 | ||
1138 | return false; | |
1139 | } | |
1140 | ||
1141 | /* For pointers p2 and p1 return p2 - p1 if the | |
1142 | difference is known and constant, otherwise return NULL. */ | |
1143 | ||
1144 | static tree | |
1145 | constant_pointer_difference (tree p1, tree p2) | |
1146 | { | |
1147 | int i, j; | |
1148 | #define CPD_ITERATIONS 5 | |
1149 | tree exps[2][CPD_ITERATIONS]; | |
1150 | tree offs[2][CPD_ITERATIONS]; | |
1151 | int cnt[2]; | |
1152 | ||
1153 | for (i = 0; i < 2; i++) | |
1154 | { | |
1155 | tree p = i ? p1 : p2; | |
1156 | tree off = size_zero_node; | |
1157 | gimple *stmt; | |
1158 | enum tree_code code; | |
1159 | ||
1160 | /* For each of p1 and p2 we need to iterate at least | |
1161 | twice, to handle ADDR_EXPR directly in p1/p2, | |
1162 | SSA_NAME with ADDR_EXPR or POINTER_PLUS_EXPR etc. | |
1163 | on definition's stmt RHS. Iterate a few extra times. */ | |
1164 | j = 0; | |
1165 | do | |
1166 | { | |
1167 | if (!POINTER_TYPE_P (TREE_TYPE (p))) | |
1168 | break; | |
1169 | if (TREE_CODE (p) == ADDR_EXPR) | |
1170 | { | |
1171 | tree q = TREE_OPERAND (p, 0); | |
1172 | HOST_WIDE_INT offset; | |
1173 | tree base = get_addr_base_and_unit_offset (q, &offset); | |
1174 | if (base) | |
1175 | { | |
1176 | q = base; | |
1177 | if (offset) | |
1178 | off = size_binop (PLUS_EXPR, off, size_int (offset)); | |
1179 | } | |
1180 | if (TREE_CODE (q) == MEM_REF | |
1181 | && TREE_CODE (TREE_OPERAND (q, 0)) == SSA_NAME) | |
1182 | { | |
1183 | p = TREE_OPERAND (q, 0); | |
1184 | off = size_binop (PLUS_EXPR, off, | |
1185 | wide_int_to_tree (sizetype, | |
1186 | mem_ref_offset (q))); | |
1187 | } | |
1188 | else | |
1189 | { | |
1190 | exps[i][j] = q; | |
1191 | offs[i][j++] = off; | |
1192 | break; | |
1193 | } | |
1194 | } | |
1195 | if (TREE_CODE (p) != SSA_NAME) | |
1196 | break; | |
1197 | exps[i][j] = p; | |
1198 | offs[i][j++] = off; | |
1199 | if (j == CPD_ITERATIONS) | |
1200 | break; | |
1201 | stmt = SSA_NAME_DEF_STMT (p); | |
1202 | if (!is_gimple_assign (stmt) || gimple_assign_lhs (stmt) != p) | |
1203 | break; | |
1204 | code = gimple_assign_rhs_code (stmt); | |
1205 | if (code == POINTER_PLUS_EXPR) | |
1206 | { | |
1207 | if (TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST) | |
1208 | break; | |
1209 | off = size_binop (PLUS_EXPR, off, gimple_assign_rhs2 (stmt)); | |
1210 | p = gimple_assign_rhs1 (stmt); | |
1211 | } | |
1212 | else if (code == ADDR_EXPR || CONVERT_EXPR_CODE_P (code)) | |
1213 | p = gimple_assign_rhs1 (stmt); | |
1214 | else | |
1215 | break; | |
1216 | } | |
1217 | while (1); | |
1218 | cnt[i] = j; | |
1219 | } | |
1220 | ||
1221 | for (i = 0; i < cnt[0]; i++) | |
1222 | for (j = 0; j < cnt[1]; j++) | |
1223 | if (exps[0][i] == exps[1][j]) | |
1224 | return size_binop (MINUS_EXPR, offs[0][i], offs[1][j]); | |
1225 | ||
1226 | return NULL_TREE; | |
1227 | } | |
1228 | ||
1229 | /* *GSI_P is a GIMPLE_CALL to a builtin function. | |
1230 | Optimize | |
1231 | memcpy (p, "abcd", 4); | |
1232 | memset (p + 4, ' ', 3); | |
1233 | into | |
1234 | memcpy (p, "abcd ", 7); | |
1235 | call if the latter can be stored by pieces during expansion. */ | |
1236 | ||
1237 | static bool | |
1238 | simplify_builtin_call (gimple_stmt_iterator *gsi_p, tree callee2) | |
1239 | { | |
1240 | gimple *stmt1, *stmt2 = gsi_stmt (*gsi_p); | |
1241 | tree vuse = gimple_vuse (stmt2); | |
1242 | if (vuse == NULL) | |
1243 | return false; | |
1244 | stmt1 = SSA_NAME_DEF_STMT (vuse); | |
1245 | ||
1246 | switch (DECL_FUNCTION_CODE (callee2)) | |
1247 | { | |
1248 | case BUILT_IN_MEMSET: | |
1249 | if (gimple_call_num_args (stmt2) != 3 | |
1250 | || gimple_call_lhs (stmt2) | |
1251 | || CHAR_BIT != 8 | |
1252 | || BITS_PER_UNIT != 8) | |
1253 | break; | |
1254 | else | |
1255 | { | |
1256 | tree callee1; | |
1257 | tree ptr1, src1, str1, off1, len1, lhs1; | |
1258 | tree ptr2 = gimple_call_arg (stmt2, 0); | |
1259 | tree val2 = gimple_call_arg (stmt2, 1); | |
1260 | tree len2 = gimple_call_arg (stmt2, 2); | |
1261 | tree diff, vdef, new_str_cst; | |
1262 | gimple *use_stmt; | |
1263 | unsigned int ptr1_align; | |
1264 | unsigned HOST_WIDE_INT src_len; | |
1265 | char *src_buf; | |
1266 | use_operand_p use_p; | |
1267 | ||
1268 | if (!tree_fits_shwi_p (val2) | |
1269 | || !tree_fits_uhwi_p (len2) | |
1270 | || compare_tree_int (len2, 1024) == 1) | |
1271 | break; | |
1272 | if (is_gimple_call (stmt1)) | |
1273 | { | |
1274 | /* If first stmt is a call, it needs to be memcpy | |
1275 | or mempcpy, with string literal as second argument and | |
1276 | constant length. */ | |
1277 | callee1 = gimple_call_fndecl (stmt1); | |
1278 | if (callee1 == NULL_TREE | |
1279 | || DECL_BUILT_IN_CLASS (callee1) != BUILT_IN_NORMAL | |
1280 | || gimple_call_num_args (stmt1) != 3) | |
1281 | break; | |
1282 | if (DECL_FUNCTION_CODE (callee1) != BUILT_IN_MEMCPY | |
1283 | && DECL_FUNCTION_CODE (callee1) != BUILT_IN_MEMPCPY) | |
1284 | break; | |
1285 | ptr1 = gimple_call_arg (stmt1, 0); | |
1286 | src1 = gimple_call_arg (stmt1, 1); | |
1287 | len1 = gimple_call_arg (stmt1, 2); | |
1288 | lhs1 = gimple_call_lhs (stmt1); | |
1289 | if (!tree_fits_uhwi_p (len1)) | |
1290 | break; | |
1291 | str1 = string_constant (src1, &off1); | |
1292 | if (str1 == NULL_TREE) | |
1293 | break; | |
1294 | if (!tree_fits_uhwi_p (off1) | |
1295 | || compare_tree_int (off1, TREE_STRING_LENGTH (str1) - 1) > 0 | |
1296 | || compare_tree_int (len1, TREE_STRING_LENGTH (str1) | |
1297 | - tree_to_uhwi (off1)) > 0 | |
1298 | || TREE_CODE (TREE_TYPE (str1)) != ARRAY_TYPE | |
1299 | || TYPE_MODE (TREE_TYPE (TREE_TYPE (str1))) | |
1300 | != TYPE_MODE (char_type_node)) | |
1301 | break; | |
1302 | } | |
1303 | else if (gimple_assign_single_p (stmt1)) | |
1304 | { | |
1305 | /* Otherwise look for length 1 memcpy optimized into | |
1306 | assignment. */ | |
1307 | ptr1 = gimple_assign_lhs (stmt1); | |
1308 | src1 = gimple_assign_rhs1 (stmt1); | |
1309 | if (TREE_CODE (ptr1) != MEM_REF | |
1310 | || TYPE_MODE (TREE_TYPE (ptr1)) != TYPE_MODE (char_type_node) | |
1311 | || !tree_fits_shwi_p (src1)) | |
1312 | break; | |
1313 | ptr1 = build_fold_addr_expr (ptr1); | |
1314 | callee1 = NULL_TREE; | |
1315 | len1 = size_one_node; | |
1316 | lhs1 = NULL_TREE; | |
1317 | off1 = size_zero_node; | |
1318 | str1 = NULL_TREE; | |
1319 | } | |
1320 | else | |
1321 | break; | |
1322 | ||
1323 | diff = constant_pointer_difference (ptr1, ptr2); | |
1324 | if (diff == NULL && lhs1 != NULL) | |
1325 | { | |
1326 | diff = constant_pointer_difference (lhs1, ptr2); | |
1327 | if (DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY | |
1328 | && diff != NULL) | |
1329 | diff = size_binop (PLUS_EXPR, diff, | |
1330 | fold_convert (sizetype, len1)); | |
1331 | } | |
1332 | /* If the difference between the second and first destination pointer | |
1333 | is not constant, or is bigger than memcpy length, bail out. */ | |
1334 | if (diff == NULL | |
1335 | || !tree_fits_uhwi_p (diff) | |
1336 | || tree_int_cst_lt (len1, diff) | |
1337 | || compare_tree_int (diff, 1024) == 1) | |
1338 | break; | |
1339 | ||
1340 | /* Use maximum of difference plus memset length and memcpy length | |
1341 | as the new memcpy length, if it is too big, bail out. */ | |
1342 | src_len = tree_to_uhwi (diff); | |
1343 | src_len += tree_to_uhwi (len2); | |
1344 | if (src_len < tree_to_uhwi (len1)) | |
1345 | src_len = tree_to_uhwi (len1); | |
1346 | if (src_len > 1024) | |
1347 | break; | |
1348 | ||
1349 | /* If mempcpy value is used elsewhere, bail out, as mempcpy | |
1350 | with bigger length will return different result. */ | |
1351 | if (lhs1 != NULL_TREE | |
1352 | && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY | |
1353 | && (TREE_CODE (lhs1) != SSA_NAME | |
1354 | || !single_imm_use (lhs1, &use_p, &use_stmt) | |
1355 | || use_stmt != stmt2)) | |
1356 | break; | |
1357 | ||
1358 | /* If anything reads memory in between memcpy and memset | |
1359 | call, the modified memcpy call might change it. */ | |
1360 | vdef = gimple_vdef (stmt1); | |
1361 | if (vdef != NULL | |
1362 | && (!single_imm_use (vdef, &use_p, &use_stmt) | |
1363 | || use_stmt != stmt2)) | |
1364 | break; | |
1365 | ||
1366 | ptr1_align = get_pointer_alignment (ptr1); | |
1367 | /* Construct the new source string literal. */ | |
1368 | src_buf = XALLOCAVEC (char, src_len + 1); | |
1369 | if (callee1) | |
1370 | memcpy (src_buf, | |
1371 | TREE_STRING_POINTER (str1) + tree_to_uhwi (off1), | |
1372 | tree_to_uhwi (len1)); | |
1373 | else | |
1374 | src_buf[0] = tree_to_shwi (src1); | |
1375 | memset (src_buf + tree_to_uhwi (diff), | |
1376 | tree_to_shwi (val2), tree_to_uhwi (len2)); | |
1377 | src_buf[src_len] = '\0'; | |
1378 | /* Neither builtin_strncpy_read_str nor builtin_memcpy_read_str | |
1379 | handle embedded '\0's. */ | |
1380 | if (strlen (src_buf) != src_len) | |
1381 | break; | |
1382 | rtl_profile_for_bb (gimple_bb (stmt2)); | |
1383 | /* If the new memcpy wouldn't be emitted by storing the literal | |
1384 | by pieces, this optimization might enlarge .rodata too much, | |
1385 | as commonly used string literals couldn't be shared any | |
1386 | longer. */ | |
1387 | if (!can_store_by_pieces (src_len, | |
1388 | builtin_strncpy_read_str, | |
1389 | src_buf, ptr1_align, false)) | |
1390 | break; | |
1391 | ||
1392 | new_str_cst = build_string_literal (src_len, src_buf); | |
1393 | if (callee1) | |
1394 | { | |
1395 | /* If STMT1 is a mem{,p}cpy call, adjust it and remove | |
1396 | memset call. */ | |
1397 | if (lhs1 && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY) | |
1398 | gimple_call_set_lhs (stmt1, NULL_TREE); | |
1399 | gimple_call_set_arg (stmt1, 1, new_str_cst); | |
1400 | gimple_call_set_arg (stmt1, 2, | |
1401 | build_int_cst (TREE_TYPE (len1), src_len)); | |
1402 | update_stmt (stmt1); | |
1403 | unlink_stmt_vdef (stmt2); | |
1404 | gsi_remove (gsi_p, true); | |
1405 | fwprop_invalidate_lattice (gimple_get_lhs (stmt2)); | |
1406 | release_defs (stmt2); | |
1407 | if (lhs1 && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY) | |
1408 | { | |
1409 | fwprop_invalidate_lattice (lhs1); | |
1410 | release_ssa_name (lhs1); | |
1411 | } | |
1412 | return true; | |
1413 | } | |
1414 | else | |
1415 | { | |
1416 | /* Otherwise, if STMT1 is length 1 memcpy optimized into | |
1417 | assignment, remove STMT1 and change memset call into | |
1418 | memcpy call. */ | |
1419 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt1); | |
1420 | ||
1421 | if (!is_gimple_val (ptr1)) | |
1422 | ptr1 = force_gimple_operand_gsi (gsi_p, ptr1, true, NULL_TREE, | |
1423 | true, GSI_SAME_STMT); | |
1424 | gimple_call_set_fndecl (stmt2, | |
1425 | builtin_decl_explicit (BUILT_IN_MEMCPY)); | |
1426 | gimple_call_set_arg (stmt2, 0, ptr1); | |
1427 | gimple_call_set_arg (stmt2, 1, new_str_cst); | |
1428 | gimple_call_set_arg (stmt2, 2, | |
1429 | build_int_cst (TREE_TYPE (len2), src_len)); | |
1430 | unlink_stmt_vdef (stmt1); | |
1431 | gsi_remove (&gsi, true); | |
1432 | fwprop_invalidate_lattice (gimple_get_lhs (stmt1)); | |
1433 | release_defs (stmt1); | |
1434 | update_stmt (stmt2); | |
1435 | return false; | |
1436 | } | |
1437 | } | |
1438 | break; | |
1439 | default: | |
1440 | break; | |
1441 | } | |
1442 | return false; | |
1443 | } | |
1444 | ||
1445 | /* Given a ssa_name in NAME see if it was defined by an assignment and | |
1446 | set CODE to be the code and ARG1 to the first operand on the rhs and ARG2 | |
1447 | to the second operand on the rhs. */ | |
1448 | ||
1449 | static inline void | |
1450 | defcodefor_name (tree name, enum tree_code *code, tree *arg1, tree *arg2) | |
1451 | { | |
1452 | gimple *def; | |
1453 | enum tree_code code1; | |
1454 | tree arg11; | |
1455 | tree arg21; | |
1456 | tree arg31; | |
1457 | enum gimple_rhs_class grhs_class; | |
1458 | ||
1459 | code1 = TREE_CODE (name); | |
1460 | arg11 = name; | |
1461 | arg21 = NULL_TREE; | |
1462 | arg31 = NULL_TREE; | |
1463 | grhs_class = get_gimple_rhs_class (code1); | |
1464 | ||
1465 | if (code1 == SSA_NAME) | |
1466 | { | |
1467 | def = SSA_NAME_DEF_STMT (name); | |
1468 | ||
1469 | if (def && is_gimple_assign (def) | |
1470 | && can_propagate_from (def)) | |
1471 | { | |
1472 | code1 = gimple_assign_rhs_code (def); | |
1473 | arg11 = gimple_assign_rhs1 (def); | |
1474 | arg21 = gimple_assign_rhs2 (def); | |
1475 | arg31 = gimple_assign_rhs3 (def); | |
1476 | } | |
1477 | } | |
1478 | else if (grhs_class != GIMPLE_SINGLE_RHS) | |
1479 | code1 = ERROR_MARK; | |
1480 | ||
1481 | *code = code1; | |
1482 | *arg1 = arg11; | |
1483 | if (arg2) | |
1484 | *arg2 = arg21; | |
1485 | if (arg31) | |
1486 | *code = ERROR_MARK; | |
1487 | } | |
1488 | ||
1489 | ||
1490 | /* Recognize rotation patterns. Return true if a transformation | |
1491 | applied, otherwise return false. | |
1492 | ||
1493 | We are looking for X with unsigned type T with bitsize B, OP being | |
1494 | +, | or ^, some type T2 wider than T and | |
1495 | (X << CNT1) OP (X >> CNT2) iff CNT1 + CNT2 == B | |
1496 | ((T) ((T2) X << CNT1)) OP ((T) ((T2) X >> CNT2)) iff CNT1 + CNT2 == B | |
1497 | (X << Y) OP (X >> (B - Y)) | |
1498 | (X << (int) Y) OP (X >> (int) (B - Y)) | |
1499 | ((T) ((T2) X << Y)) OP ((T) ((T2) X >> (B - Y))) | |
1500 | ((T) ((T2) X << (int) Y)) OP ((T) ((T2) X >> (int) (B - Y))) | |
1501 | (X << Y) | (X >> ((-Y) & (B - 1))) | |
1502 | (X << (int) Y) | (X >> (int) ((-Y) & (B - 1))) | |
1503 | ((T) ((T2) X << Y)) | ((T) ((T2) X >> ((-Y) & (B - 1)))) | |
1504 | ((T) ((T2) X << (int) Y)) | ((T) ((T2) X >> (int) ((-Y) & (B - 1)))) | |
1505 | ||
1506 | and transform these into: | |
1507 | X r<< CNT1 | |
1508 | X r<< Y | |
1509 | ||
1510 | Note, in the patterns with T2 type, the type of OP operands | |
1511 | might be even a signed type, but should have precision B. */ | |
1512 | ||
1513 | static bool | |
1514 | simplify_rotate (gimple_stmt_iterator *gsi) | |
1515 | { | |
1516 | gimple *stmt = gsi_stmt (*gsi); | |
1517 | tree arg[2], rtype, rotcnt = NULL_TREE; | |
1518 | tree def_arg1[2], def_arg2[2]; | |
1519 | enum tree_code def_code[2]; | |
1520 | tree lhs; | |
1521 | int i; | |
1522 | bool swapped_p = false; | |
1523 | gimple *g; | |
1524 | ||
1525 | arg[0] = gimple_assign_rhs1 (stmt); | |
1526 | arg[1] = gimple_assign_rhs2 (stmt); | |
1527 | rtype = TREE_TYPE (arg[0]); | |
1528 | ||
1529 | /* Only create rotates in complete modes. Other cases are not | |
1530 | expanded properly. */ | |
1531 | if (!INTEGRAL_TYPE_P (rtype) | |
1532 | || TYPE_PRECISION (rtype) != GET_MODE_PRECISION (TYPE_MODE (rtype))) | |
1533 | return false; | |
1534 | ||
1535 | for (i = 0; i < 2; i++) | |
1536 | defcodefor_name (arg[i], &def_code[i], &def_arg1[i], &def_arg2[i]); | |
1537 | ||
1538 | /* Look through narrowing conversions. */ | |
1539 | if (CONVERT_EXPR_CODE_P (def_code[0]) | |
1540 | && CONVERT_EXPR_CODE_P (def_code[1]) | |
1541 | && INTEGRAL_TYPE_P (TREE_TYPE (def_arg1[0])) | |
1542 | && INTEGRAL_TYPE_P (TREE_TYPE (def_arg1[1])) | |
1543 | && TYPE_PRECISION (TREE_TYPE (def_arg1[0])) | |
1544 | == TYPE_PRECISION (TREE_TYPE (def_arg1[1])) | |
1545 | && TYPE_PRECISION (TREE_TYPE (def_arg1[0])) > TYPE_PRECISION (rtype) | |
1546 | && has_single_use (arg[0]) | |
1547 | && has_single_use (arg[1])) | |
1548 | { | |
1549 | for (i = 0; i < 2; i++) | |
1550 | { | |
1551 | arg[i] = def_arg1[i]; | |
1552 | defcodefor_name (arg[i], &def_code[i], &def_arg1[i], &def_arg2[i]); | |
1553 | } | |
1554 | } | |
1555 | ||
1556 | /* One operand has to be LSHIFT_EXPR and one RSHIFT_EXPR. */ | |
1557 | for (i = 0; i < 2; i++) | |
1558 | if (def_code[i] != LSHIFT_EXPR && def_code[i] != RSHIFT_EXPR) | |
1559 | return false; | |
1560 | else if (!has_single_use (arg[i])) | |
1561 | return false; | |
1562 | if (def_code[0] == def_code[1]) | |
1563 | return false; | |
1564 | ||
1565 | /* If we've looked through narrowing conversions before, look through | |
1566 | widening conversions from unsigned type with the same precision | |
1567 | as rtype here. */ | |
1568 | if (TYPE_PRECISION (TREE_TYPE (def_arg1[0])) != TYPE_PRECISION (rtype)) | |
1569 | for (i = 0; i < 2; i++) | |
1570 | { | |
1571 | tree tem; | |
1572 | enum tree_code code; | |
1573 | defcodefor_name (def_arg1[i], &code, &tem, NULL); | |
1574 | if (!CONVERT_EXPR_CODE_P (code) | |
1575 | || !INTEGRAL_TYPE_P (TREE_TYPE (tem)) | |
1576 | || TYPE_PRECISION (TREE_TYPE (tem)) != TYPE_PRECISION (rtype)) | |
1577 | return false; | |
1578 | def_arg1[i] = tem; | |
1579 | } | |
1580 | /* Both shifts have to use the same first operand. */ | |
1581 | if (TREE_CODE (def_arg1[0]) != SSA_NAME || def_arg1[0] != def_arg1[1]) | |
1582 | return false; | |
1583 | if (!TYPE_UNSIGNED (TREE_TYPE (def_arg1[0]))) | |
1584 | return false; | |
1585 | ||
1586 | /* CNT1 + CNT2 == B case above. */ | |
1587 | if (tree_fits_uhwi_p (def_arg2[0]) | |
1588 | && tree_fits_uhwi_p (def_arg2[1]) | |
1589 | && tree_to_uhwi (def_arg2[0]) | |
1590 | + tree_to_uhwi (def_arg2[1]) == TYPE_PRECISION (rtype)) | |
1591 | rotcnt = def_arg2[0]; | |
1592 | else if (TREE_CODE (def_arg2[0]) != SSA_NAME | |
1593 | || TREE_CODE (def_arg2[1]) != SSA_NAME) | |
1594 | return false; | |
1595 | else | |
1596 | { | |
1597 | tree cdef_arg1[2], cdef_arg2[2], def_arg2_alt[2]; | |
1598 | enum tree_code cdef_code[2]; | |
1599 | /* Look through conversion of the shift count argument. | |
1600 | The C/C++ FE cast any shift count argument to integer_type_node. | |
1601 | The only problem might be if the shift count type maximum value | |
1602 | is equal or smaller than number of bits in rtype. */ | |
1603 | for (i = 0; i < 2; i++) | |
1604 | { | |
1605 | def_arg2_alt[i] = def_arg2[i]; | |
1606 | defcodefor_name (def_arg2[i], &cdef_code[i], | |
1607 | &cdef_arg1[i], &cdef_arg2[i]); | |
1608 | if (CONVERT_EXPR_CODE_P (cdef_code[i]) | |
1609 | && INTEGRAL_TYPE_P (TREE_TYPE (cdef_arg1[i])) | |
1610 | && TYPE_PRECISION (TREE_TYPE (cdef_arg1[i])) | |
1611 | > floor_log2 (TYPE_PRECISION (rtype)) | |
1612 | && TYPE_PRECISION (TREE_TYPE (cdef_arg1[i])) | |
1613 | == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (cdef_arg1[i])))) | |
1614 | { | |
1615 | def_arg2_alt[i] = cdef_arg1[i]; | |
1616 | defcodefor_name (def_arg2_alt[i], &cdef_code[i], | |
1617 | &cdef_arg1[i], &cdef_arg2[i]); | |
1618 | } | |
1619 | } | |
1620 | for (i = 0; i < 2; i++) | |
1621 | /* Check for one shift count being Y and the other B - Y, | |
1622 | with optional casts. */ | |
1623 | if (cdef_code[i] == MINUS_EXPR | |
1624 | && tree_fits_shwi_p (cdef_arg1[i]) | |
1625 | && tree_to_shwi (cdef_arg1[i]) == TYPE_PRECISION (rtype) | |
1626 | && TREE_CODE (cdef_arg2[i]) == SSA_NAME) | |
1627 | { | |
1628 | tree tem; | |
1629 | enum tree_code code; | |
1630 | ||
1631 | if (cdef_arg2[i] == def_arg2[1 - i] | |
1632 | || cdef_arg2[i] == def_arg2_alt[1 - i]) | |
1633 | { | |
1634 | rotcnt = cdef_arg2[i]; | |
1635 | break; | |
1636 | } | |
1637 | defcodefor_name (cdef_arg2[i], &code, &tem, NULL); | |
1638 | if (CONVERT_EXPR_CODE_P (code) | |
1639 | && INTEGRAL_TYPE_P (TREE_TYPE (tem)) | |
1640 | && TYPE_PRECISION (TREE_TYPE (tem)) | |
1641 | > floor_log2 (TYPE_PRECISION (rtype)) | |
1642 | && TYPE_PRECISION (TREE_TYPE (tem)) | |
1643 | == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem))) | |
1644 | && (tem == def_arg2[1 - i] | |
1645 | || tem == def_arg2_alt[1 - i])) | |
1646 | { | |
1647 | rotcnt = tem; | |
1648 | break; | |
1649 | } | |
1650 | } | |
1651 | /* The above sequence isn't safe for Y being 0, | |
1652 | because then one of the shifts triggers undefined behavior. | |
1653 | This alternative is safe even for rotation count of 0. | |
1654 | One shift count is Y and the other (-Y) & (B - 1). */ | |
1655 | else if (cdef_code[i] == BIT_AND_EXPR | |
1656 | && tree_fits_shwi_p (cdef_arg2[i]) | |
1657 | && tree_to_shwi (cdef_arg2[i]) | |
1658 | == TYPE_PRECISION (rtype) - 1 | |
1659 | && TREE_CODE (cdef_arg1[i]) == SSA_NAME | |
1660 | && gimple_assign_rhs_code (stmt) == BIT_IOR_EXPR) | |
1661 | { | |
1662 | tree tem; | |
1663 | enum tree_code code; | |
1664 | ||
1665 | defcodefor_name (cdef_arg1[i], &code, &tem, NULL); | |
1666 | if (CONVERT_EXPR_CODE_P (code) | |
1667 | && INTEGRAL_TYPE_P (TREE_TYPE (tem)) | |
1668 | && TYPE_PRECISION (TREE_TYPE (tem)) | |
1669 | > floor_log2 (TYPE_PRECISION (rtype)) | |
1670 | && TYPE_PRECISION (TREE_TYPE (tem)) | |
1671 | == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem)))) | |
1672 | defcodefor_name (tem, &code, &tem, NULL); | |
1673 | ||
1674 | if (code == NEGATE_EXPR) | |
1675 | { | |
1676 | if (tem == def_arg2[1 - i] || tem == def_arg2_alt[1 - i]) | |
1677 | { | |
1678 | rotcnt = tem; | |
1679 | break; | |
1680 | } | |
1681 | defcodefor_name (tem, &code, &tem, NULL); | |
1682 | if (CONVERT_EXPR_CODE_P (code) | |
1683 | && INTEGRAL_TYPE_P (TREE_TYPE (tem)) | |
1684 | && TYPE_PRECISION (TREE_TYPE (tem)) | |
1685 | > floor_log2 (TYPE_PRECISION (rtype)) | |
1686 | && TYPE_PRECISION (TREE_TYPE (tem)) | |
1687 | == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem))) | |
1688 | && (tem == def_arg2[1 - i] | |
1689 | || tem == def_arg2_alt[1 - i])) | |
1690 | { | |
1691 | rotcnt = tem; | |
1692 | break; | |
1693 | } | |
1694 | } | |
1695 | } | |
1696 | if (rotcnt == NULL_TREE) | |
1697 | return false; | |
1698 | swapped_p = i != 1; | |
1699 | } | |
1700 | ||
1701 | if (!useless_type_conversion_p (TREE_TYPE (def_arg2[0]), | |
1702 | TREE_TYPE (rotcnt))) | |
1703 | { | |
1704 | g = gimple_build_assign (make_ssa_name (TREE_TYPE (def_arg2[0])), | |
1705 | NOP_EXPR, rotcnt); | |
1706 | gsi_insert_before (gsi, g, GSI_SAME_STMT); | |
1707 | rotcnt = gimple_assign_lhs (g); | |
1708 | } | |
1709 | lhs = gimple_assign_lhs (stmt); | |
1710 | if (!useless_type_conversion_p (rtype, TREE_TYPE (def_arg1[0]))) | |
1711 | lhs = make_ssa_name (TREE_TYPE (def_arg1[0])); | |
1712 | g = gimple_build_assign (lhs, | |
1713 | ((def_code[0] == LSHIFT_EXPR) ^ swapped_p) | |
1714 | ? LROTATE_EXPR : RROTATE_EXPR, def_arg1[0], rotcnt); | |
1715 | if (!useless_type_conversion_p (rtype, TREE_TYPE (def_arg1[0]))) | |
1716 | { | |
1717 | gsi_insert_before (gsi, g, GSI_SAME_STMT); | |
1718 | g = gimple_build_assign (gimple_assign_lhs (stmt), NOP_EXPR, lhs); | |
1719 | } | |
1720 | gsi_replace (gsi, g, false); | |
1721 | return true; | |
1722 | } | |
1723 | ||
1724 | /* Combine an element access with a shuffle. Returns true if there were | |
1725 | any changes made, else it returns false. */ | |
1726 | ||
1727 | static bool | |
1728 | simplify_bitfield_ref (gimple_stmt_iterator *gsi) | |
1729 | { | |
1730 | gimple *stmt = gsi_stmt (*gsi); | |
1731 | gimple *def_stmt; | |
1732 | tree op, op0, op1, op2; | |
1733 | tree elem_type; | |
1734 | unsigned idx, n, size; | |
1735 | enum tree_code code; | |
1736 | ||
1737 | op = gimple_assign_rhs1 (stmt); | |
1738 | gcc_checking_assert (TREE_CODE (op) == BIT_FIELD_REF); | |
1739 | ||
1740 | op0 = TREE_OPERAND (op, 0); | |
1741 | if (TREE_CODE (op0) != SSA_NAME | |
1742 | || TREE_CODE (TREE_TYPE (op0)) != VECTOR_TYPE) | |
1743 | return false; | |
1744 | ||
1745 | def_stmt = get_prop_source_stmt (op0, false, NULL); | |
1746 | if (!def_stmt || !can_propagate_from (def_stmt)) | |
1747 | return false; | |
1748 | ||
1749 | op1 = TREE_OPERAND (op, 1); | |
1750 | op2 = TREE_OPERAND (op, 2); | |
1751 | code = gimple_assign_rhs_code (def_stmt); | |
1752 | ||
1753 | if (code == CONSTRUCTOR) | |
1754 | { | |
1755 | tree tem = fold_ternary (BIT_FIELD_REF, TREE_TYPE (op), | |
1756 | gimple_assign_rhs1 (def_stmt), op1, op2); | |
1757 | if (!tem || !valid_gimple_rhs_p (tem)) | |
1758 | return false; | |
1759 | gimple_assign_set_rhs_from_tree (gsi, tem); | |
1760 | update_stmt (gsi_stmt (*gsi)); | |
1761 | return true; | |
1762 | } | |
1763 | ||
1764 | elem_type = TREE_TYPE (TREE_TYPE (op0)); | |
1765 | if (TREE_TYPE (op) != elem_type) | |
1766 | return false; | |
1767 | ||
1768 | size = TREE_INT_CST_LOW (TYPE_SIZE (elem_type)); | |
1769 | n = TREE_INT_CST_LOW (op1) / size; | |
1770 | if (n != 1) | |
1771 | return false; | |
1772 | idx = TREE_INT_CST_LOW (op2) / size; | |
1773 | ||
1774 | if (code == VEC_PERM_EXPR) | |
1775 | { | |
1776 | tree p, m, tem; | |
1777 | unsigned nelts; | |
1778 | m = gimple_assign_rhs3 (def_stmt); | |
1779 | if (TREE_CODE (m) != VECTOR_CST) | |
1780 | return false; | |
1781 | nelts = VECTOR_CST_NELTS (m); | |
1782 | idx = TREE_INT_CST_LOW (VECTOR_CST_ELT (m, idx)); | |
1783 | idx %= 2 * nelts; | |
1784 | if (idx < nelts) | |
1785 | { | |
1786 | p = gimple_assign_rhs1 (def_stmt); | |
1787 | } | |
1788 | else | |
1789 | { | |
1790 | p = gimple_assign_rhs2 (def_stmt); | |
1791 | idx -= nelts; | |
1792 | } | |
1793 | tem = build3 (BIT_FIELD_REF, TREE_TYPE (op), | |
1794 | unshare_expr (p), op1, bitsize_int (idx * size)); | |
1795 | gimple_assign_set_rhs1 (stmt, tem); | |
1796 | fold_stmt (gsi); | |
1797 | update_stmt (gsi_stmt (*gsi)); | |
1798 | return true; | |
1799 | } | |
1800 | ||
1801 | return false; | |
1802 | } | |
1803 | ||
1804 | /* Determine whether applying the 2 permutations (mask1 then mask2) | |
1805 | gives back one of the input. */ | |
1806 | ||
1807 | static int | |
1808 | is_combined_permutation_identity (tree mask1, tree mask2) | |
1809 | { | |
1810 | tree mask; | |
1811 | unsigned int nelts, i, j; | |
1812 | bool maybe_identity1 = true; | |
1813 | bool maybe_identity2 = true; | |
1814 | ||
1815 | gcc_checking_assert (TREE_CODE (mask1) == VECTOR_CST | |
1816 | && TREE_CODE (mask2) == VECTOR_CST); | |
1817 | mask = fold_ternary (VEC_PERM_EXPR, TREE_TYPE (mask1), mask1, mask1, mask2); | |
1818 | gcc_assert (TREE_CODE (mask) == VECTOR_CST); | |
1819 | ||
1820 | nelts = VECTOR_CST_NELTS (mask); | |
1821 | for (i = 0; i < nelts; i++) | |
1822 | { | |
1823 | tree val = VECTOR_CST_ELT (mask, i); | |
1824 | gcc_assert (TREE_CODE (val) == INTEGER_CST); | |
1825 | j = TREE_INT_CST_LOW (val) & (2 * nelts - 1); | |
1826 | if (j == i) | |
1827 | maybe_identity2 = false; | |
1828 | else if (j == i + nelts) | |
1829 | maybe_identity1 = false; | |
1830 | else | |
1831 | return 0; | |
1832 | } | |
1833 | return maybe_identity1 ? 1 : maybe_identity2 ? 2 : 0; | |
1834 | } | |
1835 | ||
1836 | /* Combine a shuffle with its arguments. Returns 1 if there were any | |
1837 | changes made, 2 if cfg-cleanup needs to run. Else it returns 0. */ | |
1838 | ||
1839 | static int | |
1840 | simplify_permutation (gimple_stmt_iterator *gsi) | |
1841 | { | |
1842 | gimple *stmt = gsi_stmt (*gsi); | |
1843 | gimple *def_stmt; | |
1844 | tree op0, op1, op2, op3, arg0, arg1; | |
1845 | enum tree_code code; | |
1846 | bool single_use_op0 = false; | |
1847 | ||
1848 | gcc_checking_assert (gimple_assign_rhs_code (stmt) == VEC_PERM_EXPR); | |
1849 | ||
1850 | op0 = gimple_assign_rhs1 (stmt); | |
1851 | op1 = gimple_assign_rhs2 (stmt); | |
1852 | op2 = gimple_assign_rhs3 (stmt); | |
1853 | ||
1854 | if (TREE_CODE (op2) != VECTOR_CST) | |
1855 | return 0; | |
1856 | ||
1857 | if (TREE_CODE (op0) == VECTOR_CST) | |
1858 | { | |
1859 | code = VECTOR_CST; | |
1860 | arg0 = op0; | |
1861 | } | |
1862 | else if (TREE_CODE (op0) == SSA_NAME) | |
1863 | { | |
1864 | def_stmt = get_prop_source_stmt (op0, false, &single_use_op0); | |
1865 | if (!def_stmt || !can_propagate_from (def_stmt)) | |
1866 | return 0; | |
1867 | ||
1868 | code = gimple_assign_rhs_code (def_stmt); | |
1869 | arg0 = gimple_assign_rhs1 (def_stmt); | |
1870 | } | |
1871 | else | |
1872 | return 0; | |
1873 | ||
1874 | /* Two consecutive shuffles. */ | |
1875 | if (code == VEC_PERM_EXPR) | |
1876 | { | |
1877 | tree orig; | |
1878 | int ident; | |
1879 | ||
1880 | if (op0 != op1) | |
1881 | return 0; | |
1882 | op3 = gimple_assign_rhs3 (def_stmt); | |
1883 | if (TREE_CODE (op3) != VECTOR_CST) | |
1884 | return 0; | |
1885 | ident = is_combined_permutation_identity (op3, op2); | |
1886 | if (!ident) | |
1887 | return 0; | |
1888 | orig = (ident == 1) ? gimple_assign_rhs1 (def_stmt) | |
1889 | : gimple_assign_rhs2 (def_stmt); | |
1890 | gimple_assign_set_rhs1 (stmt, unshare_expr (orig)); | |
1891 | gimple_assign_set_rhs_code (stmt, TREE_CODE (orig)); | |
1892 | gimple_set_num_ops (stmt, 2); | |
1893 | update_stmt (stmt); | |
1894 | return remove_prop_source_from_use (op0) ? 2 : 1; | |
1895 | } | |
1896 | ||
1897 | /* Shuffle of a constructor. */ | |
1898 | else if (code == CONSTRUCTOR || code == VECTOR_CST) | |
1899 | { | |
1900 | tree opt; | |
1901 | bool ret = false; | |
1902 | if (op0 != op1) | |
1903 | { | |
1904 | if (TREE_CODE (op0) == SSA_NAME && !single_use_op0) | |
1905 | return 0; | |
1906 | ||
1907 | if (TREE_CODE (op1) == VECTOR_CST) | |
1908 | arg1 = op1; | |
1909 | else if (TREE_CODE (op1) == SSA_NAME) | |
1910 | { | |
1911 | enum tree_code code2; | |
1912 | ||
1913 | gimple *def_stmt2 = get_prop_source_stmt (op1, true, NULL); | |
1914 | if (!def_stmt2 || !can_propagate_from (def_stmt2)) | |
1915 | return 0; | |
1916 | ||
1917 | code2 = gimple_assign_rhs_code (def_stmt2); | |
1918 | if (code2 != CONSTRUCTOR && code2 != VECTOR_CST) | |
1919 | return 0; | |
1920 | arg1 = gimple_assign_rhs1 (def_stmt2); | |
1921 | } | |
1922 | else | |
1923 | return 0; | |
1924 | } | |
1925 | else | |
1926 | { | |
1927 | /* Already used twice in this statement. */ | |
1928 | if (TREE_CODE (op0) == SSA_NAME && num_imm_uses (op0) > 2) | |
1929 | return 0; | |
1930 | arg1 = arg0; | |
1931 | } | |
1932 | opt = fold_ternary (VEC_PERM_EXPR, TREE_TYPE (op0), arg0, arg1, op2); | |
1933 | if (!opt | |
1934 | || (TREE_CODE (opt) != CONSTRUCTOR && TREE_CODE (opt) != VECTOR_CST)) | |
1935 | return 0; | |
1936 | gimple_assign_set_rhs_from_tree (gsi, opt); | |
1937 | update_stmt (gsi_stmt (*gsi)); | |
1938 | if (TREE_CODE (op0) == SSA_NAME) | |
1939 | ret = remove_prop_source_from_use (op0); | |
1940 | if (op0 != op1 && TREE_CODE (op1) == SSA_NAME) | |
1941 | ret |= remove_prop_source_from_use (op1); | |
1942 | return ret ? 2 : 1; | |
1943 | } | |
1944 | ||
1945 | return 0; | |
1946 | } | |
1947 | ||
1948 | /* Recognize a VEC_PERM_EXPR. Returns true if there were any changes. */ | |
1949 | ||
1950 | static bool | |
1951 | simplify_vector_constructor (gimple_stmt_iterator *gsi) | |
1952 | { | |
1953 | gimple *stmt = gsi_stmt (*gsi); | |
1954 | gimple *def_stmt; | |
1955 | tree op, op2, orig, type, elem_type; | |
1956 | unsigned elem_size, nelts, i; | |
1957 | enum tree_code code, conv_code; | |
1958 | constructor_elt *elt; | |
1959 | unsigned char *sel; | |
1960 | bool maybe_ident; | |
1961 | ||
1962 | gcc_checking_assert (gimple_assign_rhs_code (stmt) == CONSTRUCTOR); | |
1963 | ||
1964 | op = gimple_assign_rhs1 (stmt); | |
1965 | type = TREE_TYPE (op); | |
1966 | gcc_checking_assert (TREE_CODE (type) == VECTOR_TYPE); | |
1967 | ||
1968 | nelts = TYPE_VECTOR_SUBPARTS (type); | |
1969 | elem_type = TREE_TYPE (type); | |
1970 | elem_size = TREE_INT_CST_LOW (TYPE_SIZE (elem_type)); | |
1971 | ||
1972 | sel = XALLOCAVEC (unsigned char, nelts); | |
1973 | orig = NULL; | |
1974 | conv_code = ERROR_MARK; | |
1975 | maybe_ident = true; | |
1976 | FOR_EACH_VEC_SAFE_ELT (CONSTRUCTOR_ELTS (op), i, elt) | |
1977 | { | |
1978 | tree ref, op1; | |
1979 | ||
1980 | if (i >= nelts) | |
1981 | return false; | |
1982 | ||
1983 | if (TREE_CODE (elt->value) != SSA_NAME) | |
1984 | return false; | |
1985 | def_stmt = get_prop_source_stmt (elt->value, false, NULL); | |
1986 | if (!def_stmt) | |
1987 | return false; | |
1988 | code = gimple_assign_rhs_code (def_stmt); | |
1989 | if (code == FLOAT_EXPR | |
1990 | || code == FIX_TRUNC_EXPR) | |
1991 | { | |
1992 | op1 = gimple_assign_rhs1 (def_stmt); | |
1993 | if (conv_code == ERROR_MARK) | |
1994 | { | |
1995 | if (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (elt->value))) | |
1996 | != GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))) | |
1997 | return false; | |
1998 | conv_code = code; | |
1999 | } | |
2000 | else if (conv_code != code) | |
2001 | return false; | |
2002 | if (TREE_CODE (op1) != SSA_NAME) | |
2003 | return false; | |
2004 | def_stmt = SSA_NAME_DEF_STMT (op1); | |
2005 | if (! is_gimple_assign (def_stmt)) | |
2006 | return false; | |
2007 | code = gimple_assign_rhs_code (def_stmt); | |
2008 | } | |
2009 | if (code != BIT_FIELD_REF) | |
2010 | return false; | |
2011 | op1 = gimple_assign_rhs1 (def_stmt); | |
2012 | ref = TREE_OPERAND (op1, 0); | |
2013 | if (orig) | |
2014 | { | |
2015 | if (ref != orig) | |
2016 | return false; | |
2017 | } | |
2018 | else | |
2019 | { | |
2020 | if (TREE_CODE (ref) != SSA_NAME) | |
2021 | return false; | |
2022 | if (! VECTOR_TYPE_P (TREE_TYPE (ref)) | |
2023 | || ! useless_type_conversion_p (TREE_TYPE (op1), | |
2024 | TREE_TYPE (TREE_TYPE (ref)))) | |
2025 | return false; | |
2026 | orig = ref; | |
2027 | } | |
2028 | if (TREE_INT_CST_LOW (TREE_OPERAND (op1, 1)) != elem_size) | |
2029 | return false; | |
2030 | sel[i] = TREE_INT_CST_LOW (TREE_OPERAND (op1, 2)) / elem_size; | |
2031 | if (sel[i] != i) maybe_ident = false; | |
2032 | } | |
2033 | if (i < nelts) | |
2034 | return false; | |
2035 | ||
2036 | if (! VECTOR_TYPE_P (TREE_TYPE (orig)) | |
2037 | || (TYPE_VECTOR_SUBPARTS (type) | |
2038 | != TYPE_VECTOR_SUBPARTS (TREE_TYPE (orig)))) | |
2039 | return false; | |
2040 | ||
2041 | tree tem; | |
2042 | if (conv_code != ERROR_MARK | |
2043 | && (! supportable_convert_operation (conv_code, type, TREE_TYPE (orig), | |
2044 | &tem, &conv_code) | |
2045 | || conv_code == CALL_EXPR)) | |
2046 | return false; | |
2047 | ||
2048 | if (maybe_ident) | |
2049 | { | |
2050 | if (conv_code == ERROR_MARK) | |
2051 | gimple_assign_set_rhs_from_tree (gsi, orig); | |
2052 | else | |
2053 | gimple_assign_set_rhs_with_ops (gsi, conv_code, orig, | |
2054 | NULL_TREE, NULL_TREE); | |
2055 | } | |
2056 | else | |
2057 | { | |
2058 | tree mask_type, *mask_elts; | |
2059 | ||
2060 | if (!can_vec_perm_p (TYPE_MODE (type), false, sel)) | |
2061 | return false; | |
2062 | mask_type | |
2063 | = build_vector_type (build_nonstandard_integer_type (elem_size, 1), | |
2064 | nelts); | |
2065 | if (GET_MODE_CLASS (TYPE_MODE (mask_type)) != MODE_VECTOR_INT | |
2066 | || GET_MODE_SIZE (TYPE_MODE (mask_type)) | |
2067 | != GET_MODE_SIZE (TYPE_MODE (type))) | |
2068 | return false; | |
2069 | mask_elts = XALLOCAVEC (tree, nelts); | |
2070 | for (i = 0; i < nelts; i++) | |
2071 | mask_elts[i] = build_int_cst (TREE_TYPE (mask_type), sel[i]); | |
2072 | op2 = build_vector (mask_type, mask_elts); | |
2073 | if (conv_code == ERROR_MARK) | |
2074 | gimple_assign_set_rhs_with_ops (gsi, VEC_PERM_EXPR, orig, orig, op2); | |
2075 | else | |
2076 | { | |
2077 | gimple *perm | |
2078 | = gimple_build_assign (make_ssa_name (TREE_TYPE (orig)), | |
2079 | VEC_PERM_EXPR, orig, orig, op2); | |
2080 | orig = gimple_assign_lhs (perm); | |
2081 | gsi_insert_before (gsi, perm, GSI_SAME_STMT); | |
2082 | gimple_assign_set_rhs_with_ops (gsi, conv_code, orig, | |
2083 | NULL_TREE, NULL_TREE); | |
2084 | } | |
2085 | } | |
2086 | update_stmt (gsi_stmt (*gsi)); | |
2087 | return true; | |
2088 | } | |
2089 | ||
2090 | ||
2091 | /* Primitive "lattice" function for gimple_simplify. */ | |
2092 | ||
2093 | static tree | |
2094 | fwprop_ssa_val (tree name) | |
2095 | { | |
2096 | /* First valueize NAME. */ | |
2097 | if (TREE_CODE (name) == SSA_NAME | |
2098 | && SSA_NAME_VERSION (name) < lattice.length ()) | |
2099 | { | |
2100 | tree val = lattice[SSA_NAME_VERSION (name)]; | |
2101 | if (val) | |
2102 | name = val; | |
2103 | } | |
2104 | /* We continue matching along SSA use-def edges for SSA names | |
2105 | that are not single-use. Currently there are no patterns | |
2106 | that would cause any issues with that. */ | |
2107 | return name; | |
2108 | } | |
2109 | ||
2110 | /* Main entry point for the forward propagation and statement combine | |
2111 | optimizer. */ | |
2112 | ||
2113 | namespace { | |
2114 | ||
2115 | const pass_data pass_data_forwprop = | |
2116 | { | |
2117 | GIMPLE_PASS, /* type */ | |
2118 | "forwprop", /* name */ | |
2119 | OPTGROUP_NONE, /* optinfo_flags */ | |
2120 | TV_TREE_FORWPROP, /* tv_id */ | |
2121 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2122 | 0, /* properties_provided */ | |
2123 | 0, /* properties_destroyed */ | |
2124 | 0, /* todo_flags_start */ | |
2125 | TODO_update_ssa, /* todo_flags_finish */ | |
2126 | }; | |
2127 | ||
2128 | class pass_forwprop : public gimple_opt_pass | |
2129 | { | |
2130 | public: | |
2131 | pass_forwprop (gcc::context *ctxt) | |
2132 | : gimple_opt_pass (pass_data_forwprop, ctxt) | |
2133 | {} | |
2134 | ||
2135 | /* opt_pass methods: */ | |
2136 | opt_pass * clone () { return new pass_forwprop (m_ctxt); } | |
2137 | virtual bool gate (function *) { return flag_tree_forwprop; } | |
2138 | virtual unsigned int execute (function *); | |
2139 | ||
2140 | }; // class pass_forwprop | |
2141 | ||
2142 | unsigned int | |
2143 | pass_forwprop::execute (function *fun) | |
2144 | { | |
2145 | unsigned int todoflags = 0; | |
2146 | ||
2147 | cfg_changed = false; | |
2148 | ||
2149 | /* Combine stmts with the stmts defining their operands. Do that | |
2150 | in an order that guarantees visiting SSA defs before SSA uses. */ | |
2151 | lattice.create (num_ssa_names); | |
2152 | lattice.quick_grow_cleared (num_ssa_names); | |
2153 | int *postorder = XNEWVEC (int, n_basic_blocks_for_fn (fun)); | |
2154 | int postorder_num = pre_and_rev_post_order_compute_fn (cfun, NULL, | |
2155 | postorder, false); | |
2156 | auto_vec<gimple *, 4> to_fixup; | |
2157 | to_purge = BITMAP_ALLOC (NULL); | |
2158 | for (int i = 0; i < postorder_num; ++i) | |
2159 | { | |
2160 | gimple_stmt_iterator gsi; | |
2161 | basic_block bb = BASIC_BLOCK_FOR_FN (fun, postorder[i]); | |
2162 | ||
2163 | /* Propagate into PHIs and record degenerate ones in the lattice. */ | |
2164 | for (gphi_iterator si = gsi_start_phis (bb); !gsi_end_p (si); | |
2165 | gsi_next (&si)) | |
2166 | { | |
2167 | gphi *phi = si.phi (); | |
2168 | tree res = gimple_phi_result (phi); | |
2169 | if (virtual_operand_p (res)) | |
2170 | continue; | |
2171 | ||
2172 | use_operand_p use_p; | |
2173 | ssa_op_iter it; | |
2174 | tree first = NULL_TREE; | |
2175 | bool all_same = true; | |
2176 | FOR_EACH_PHI_ARG (use_p, phi, it, SSA_OP_USE) | |
2177 | { | |
2178 | tree use = USE_FROM_PTR (use_p); | |
2179 | tree tem = fwprop_ssa_val (use); | |
2180 | if (! first) | |
2181 | first = tem; | |
2182 | else if (! operand_equal_p (first, tem, 0)) | |
2183 | all_same = false; | |
2184 | if (tem != use | |
2185 | && may_propagate_copy (use, tem)) | |
2186 | propagate_value (use_p, tem); | |
2187 | } | |
2188 | if (all_same) | |
2189 | fwprop_set_lattice_val (res, first); | |
2190 | } | |
2191 | ||
2192 | /* Apply forward propagation to all stmts in the basic-block. | |
2193 | Note we update GSI within the loop as necessary. */ | |
2194 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) | |
2195 | { | |
2196 | gimple *stmt = gsi_stmt (gsi); | |
2197 | tree lhs, rhs; | |
2198 | enum tree_code code; | |
2199 | ||
2200 | if (!is_gimple_assign (stmt)) | |
2201 | { | |
2202 | gsi_next (&gsi); | |
2203 | continue; | |
2204 | } | |
2205 | ||
2206 | lhs = gimple_assign_lhs (stmt); | |
2207 | rhs = gimple_assign_rhs1 (stmt); | |
2208 | code = gimple_assign_rhs_code (stmt); | |
2209 | if (TREE_CODE (lhs) != SSA_NAME | |
2210 | || has_zero_uses (lhs)) | |
2211 | { | |
2212 | gsi_next (&gsi); | |
2213 | continue; | |
2214 | } | |
2215 | ||
2216 | /* If this statement sets an SSA_NAME to an address, | |
2217 | try to propagate the address into the uses of the SSA_NAME. */ | |
2218 | if (code == ADDR_EXPR | |
2219 | /* Handle pointer conversions on invariant addresses | |
2220 | as well, as this is valid gimple. */ | |
2221 | || (CONVERT_EXPR_CODE_P (code) | |
2222 | && TREE_CODE (rhs) == ADDR_EXPR | |
2223 | && POINTER_TYPE_P (TREE_TYPE (lhs)))) | |
2224 | { | |
2225 | tree base = get_base_address (TREE_OPERAND (rhs, 0)); | |
2226 | if ((!base | |
2227 | || !DECL_P (base) | |
2228 | || decl_address_invariant_p (base)) | |
2229 | && !stmt_references_abnormal_ssa_name (stmt) | |
2230 | && forward_propagate_addr_expr (lhs, rhs, true)) | |
2231 | { | |
2232 | fwprop_invalidate_lattice (gimple_get_lhs (stmt)); | |
2233 | release_defs (stmt); | |
2234 | gsi_remove (&gsi, true); | |
2235 | } | |
2236 | else | |
2237 | gsi_next (&gsi); | |
2238 | } | |
2239 | else if (code == POINTER_PLUS_EXPR) | |
2240 | { | |
2241 | tree off = gimple_assign_rhs2 (stmt); | |
2242 | if (TREE_CODE (off) == INTEGER_CST | |
2243 | && can_propagate_from (stmt) | |
2244 | && !simple_iv_increment_p (stmt) | |
2245 | /* ??? Better adjust the interface to that function | |
2246 | instead of building new trees here. */ | |
2247 | && forward_propagate_addr_expr | |
2248 | (lhs, | |
2249 | build1_loc (gimple_location (stmt), | |
2250 | ADDR_EXPR, TREE_TYPE (rhs), | |
2251 | fold_build2 (MEM_REF, | |
2252 | TREE_TYPE (TREE_TYPE (rhs)), | |
2253 | rhs, | |
2254 | fold_convert (ptr_type_node, | |
2255 | off))), true)) | |
2256 | { | |
2257 | fwprop_invalidate_lattice (gimple_get_lhs (stmt)); | |
2258 | release_defs (stmt); | |
2259 | gsi_remove (&gsi, true); | |
2260 | } | |
2261 | else if (is_gimple_min_invariant (rhs)) | |
2262 | { | |
2263 | /* Make sure to fold &a[0] + off_1 here. */ | |
2264 | fold_stmt_inplace (&gsi); | |
2265 | update_stmt (stmt); | |
2266 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
2267 | gsi_next (&gsi); | |
2268 | } | |
2269 | else | |
2270 | gsi_next (&gsi); | |
2271 | } | |
2272 | else if (TREE_CODE (TREE_TYPE (lhs)) == COMPLEX_TYPE | |
2273 | && gimple_assign_load_p (stmt) | |
2274 | && !gimple_has_volatile_ops (stmt) | |
2275 | && (TREE_CODE (gimple_assign_rhs1 (stmt)) | |
2276 | != TARGET_MEM_REF) | |
2277 | && !stmt_can_throw_internal (stmt)) | |
2278 | { | |
2279 | /* Rewrite loads used only in real/imagpart extractions to | |
2280 | component-wise loads. */ | |
2281 | use_operand_p use_p; | |
2282 | imm_use_iterator iter; | |
2283 | bool rewrite = true; | |
2284 | FOR_EACH_IMM_USE_FAST (use_p, iter, lhs) | |
2285 | { | |
2286 | gimple *use_stmt = USE_STMT (use_p); | |
2287 | if (is_gimple_debug (use_stmt)) | |
2288 | continue; | |
2289 | if (!is_gimple_assign (use_stmt) | |
2290 | || (gimple_assign_rhs_code (use_stmt) != REALPART_EXPR | |
2291 | && gimple_assign_rhs_code (use_stmt) != IMAGPART_EXPR)) | |
2292 | { | |
2293 | rewrite = false; | |
2294 | break; | |
2295 | } | |
2296 | } | |
2297 | if (rewrite) | |
2298 | { | |
2299 | gimple *use_stmt; | |
2300 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) | |
2301 | { | |
2302 | if (is_gimple_debug (use_stmt)) | |
2303 | { | |
2304 | if (gimple_debug_bind_p (use_stmt)) | |
2305 | { | |
2306 | gimple_debug_bind_reset_value (use_stmt); | |
2307 | update_stmt (use_stmt); | |
2308 | } | |
2309 | continue; | |
2310 | } | |
2311 | ||
2312 | tree new_rhs = build1 (gimple_assign_rhs_code (use_stmt), | |
2313 | TREE_TYPE (TREE_TYPE (rhs)), | |
2314 | unshare_expr (rhs)); | |
2315 | gimple *new_stmt | |
2316 | = gimple_build_assign (gimple_assign_lhs (use_stmt), | |
2317 | new_rhs); | |
2318 | ||
2319 | location_t loc = gimple_location (use_stmt); | |
2320 | gimple_set_location (new_stmt, loc); | |
2321 | gimple_stmt_iterator gsi2 = gsi_for_stmt (use_stmt); | |
2322 | unlink_stmt_vdef (use_stmt); | |
2323 | gsi_remove (&gsi2, true); | |
2324 | ||
2325 | gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT); | |
2326 | } | |
2327 | ||
2328 | release_defs (stmt); | |
2329 | gsi_remove (&gsi, true); | |
2330 | } | |
2331 | else | |
2332 | gsi_next (&gsi); | |
2333 | } | |
2334 | else if (code == COMPLEX_EXPR) | |
2335 | { | |
2336 | /* Rewrite stores of a single-use complex build expression | |
2337 | to component-wise stores. */ | |
2338 | use_operand_p use_p; | |
2339 | gimple *use_stmt; | |
2340 | if (single_imm_use (lhs, &use_p, &use_stmt) | |
2341 | && gimple_store_p (use_stmt) | |
2342 | && !gimple_has_volatile_ops (use_stmt) | |
2343 | && is_gimple_assign (use_stmt) | |
2344 | && (TREE_CODE (gimple_assign_lhs (use_stmt)) | |
2345 | != TARGET_MEM_REF)) | |
2346 | { | |
2347 | tree use_lhs = gimple_assign_lhs (use_stmt); | |
2348 | tree new_lhs = build1 (REALPART_EXPR, | |
2349 | TREE_TYPE (TREE_TYPE (use_lhs)), | |
2350 | unshare_expr (use_lhs)); | |
2351 | gimple *new_stmt = gimple_build_assign (new_lhs, rhs); | |
2352 | location_t loc = gimple_location (use_stmt); | |
2353 | gimple_set_location (new_stmt, loc); | |
2354 | gimple_set_vuse (new_stmt, gimple_vuse (use_stmt)); | |
2355 | gimple_set_vdef (new_stmt, make_ssa_name (gimple_vop (cfun))); | |
2356 | SSA_NAME_DEF_STMT (gimple_vdef (new_stmt)) = new_stmt; | |
2357 | gimple_set_vuse (use_stmt, gimple_vdef (new_stmt)); | |
2358 | gimple_stmt_iterator gsi2 = gsi_for_stmt (use_stmt); | |
2359 | gsi_insert_before (&gsi2, new_stmt, GSI_SAME_STMT); | |
2360 | ||
2361 | new_lhs = build1 (IMAGPART_EXPR, | |
2362 | TREE_TYPE (TREE_TYPE (use_lhs)), | |
2363 | unshare_expr (use_lhs)); | |
2364 | gimple_assign_set_lhs (use_stmt, new_lhs); | |
2365 | gimple_assign_set_rhs1 (use_stmt, gimple_assign_rhs2 (stmt)); | |
2366 | update_stmt (use_stmt); | |
2367 | ||
2368 | release_defs (stmt); | |
2369 | gsi_remove (&gsi, true); | |
2370 | } | |
2371 | else | |
2372 | gsi_next (&gsi); | |
2373 | } | |
2374 | else | |
2375 | gsi_next (&gsi); | |
2376 | } | |
2377 | ||
2378 | /* Combine stmts with the stmts defining their operands. | |
2379 | Note we update GSI within the loop as necessary. */ | |
2380 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);) | |
2381 | { | |
2382 | gimple *stmt = gsi_stmt (gsi); | |
2383 | gimple *orig_stmt = stmt; | |
2384 | bool changed = false; | |
2385 | bool was_noreturn = (is_gimple_call (stmt) | |
2386 | && gimple_call_noreturn_p (stmt)); | |
2387 | ||
2388 | /* Mark stmt as potentially needing revisiting. */ | |
2389 | gimple_set_plf (stmt, GF_PLF_1, false); | |
2390 | ||
2391 | if (fold_stmt (&gsi, fwprop_ssa_val)) | |
2392 | { | |
2393 | changed = true; | |
2394 | stmt = gsi_stmt (gsi); | |
2395 | if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt)) | |
2396 | bitmap_set_bit (to_purge, bb->index); | |
2397 | if (!was_noreturn | |
2398 | && is_gimple_call (stmt) && gimple_call_noreturn_p (stmt)) | |
2399 | to_fixup.safe_push (stmt); | |
2400 | /* Cleanup the CFG if we simplified a condition to | |
2401 | true or false. */ | |
2402 | if (gcond *cond = dyn_cast <gcond *> (stmt)) | |
2403 | if (gimple_cond_true_p (cond) | |
2404 | || gimple_cond_false_p (cond)) | |
2405 | cfg_changed = true; | |
2406 | update_stmt (stmt); | |
2407 | } | |
2408 | ||
2409 | switch (gimple_code (stmt)) | |
2410 | { | |
2411 | case GIMPLE_ASSIGN: | |
2412 | { | |
2413 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
2414 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
2415 | ||
2416 | if (code == COND_EXPR | |
2417 | || code == VEC_COND_EXPR) | |
2418 | { | |
2419 | /* In this case the entire COND_EXPR is in rhs1. */ | |
2420 | if (forward_propagate_into_cond (&gsi)) | |
2421 | { | |
2422 | changed = true; | |
2423 | stmt = gsi_stmt (gsi); | |
2424 | } | |
2425 | } | |
2426 | else if (TREE_CODE_CLASS (code) == tcc_comparison) | |
2427 | { | |
2428 | int did_something; | |
2429 | did_something = forward_propagate_into_comparison (&gsi); | |
2430 | if (did_something == 2) | |
2431 | cfg_changed = true; | |
2432 | changed = did_something != 0; | |
2433 | } | |
2434 | else if ((code == PLUS_EXPR | |
2435 | || code == BIT_IOR_EXPR | |
2436 | || code == BIT_XOR_EXPR) | |
2437 | && simplify_rotate (&gsi)) | |
2438 | changed = true; | |
2439 | else if (code == VEC_PERM_EXPR) | |
2440 | { | |
2441 | int did_something = simplify_permutation (&gsi); | |
2442 | if (did_something == 2) | |
2443 | cfg_changed = true; | |
2444 | changed = did_something != 0; | |
2445 | } | |
2446 | else if (code == BIT_FIELD_REF) | |
2447 | changed = simplify_bitfield_ref (&gsi); | |
2448 | else if (code == CONSTRUCTOR | |
2449 | && TREE_CODE (TREE_TYPE (rhs1)) == VECTOR_TYPE) | |
2450 | changed = simplify_vector_constructor (&gsi); | |
2451 | break; | |
2452 | } | |
2453 | ||
2454 | case GIMPLE_SWITCH: | |
2455 | changed = simplify_gimple_switch (as_a <gswitch *> (stmt)); | |
2456 | break; | |
2457 | ||
2458 | case GIMPLE_COND: | |
2459 | { | |
2460 | int did_something | |
2461 | = forward_propagate_into_gimple_cond (as_a <gcond *> (stmt)); | |
2462 | if (did_something == 2) | |
2463 | cfg_changed = true; | |
2464 | changed = did_something != 0; | |
2465 | break; | |
2466 | } | |
2467 | ||
2468 | case GIMPLE_CALL: | |
2469 | { | |
2470 | tree callee = gimple_call_fndecl (stmt); | |
2471 | if (callee != NULL_TREE | |
2472 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
2473 | changed = simplify_builtin_call (&gsi, callee); | |
2474 | break; | |
2475 | } | |
2476 | ||
2477 | default:; | |
2478 | } | |
2479 | ||
2480 | if (changed) | |
2481 | { | |
2482 | /* If the stmt changed then re-visit it and the statements | |
2483 | inserted before it. */ | |
2484 | for (; !gsi_end_p (gsi); gsi_prev (&gsi)) | |
2485 | if (gimple_plf (gsi_stmt (gsi), GF_PLF_1)) | |
2486 | break; | |
2487 | if (gsi_end_p (gsi)) | |
2488 | gsi = gsi_start_bb (bb); | |
2489 | else | |
2490 | gsi_next (&gsi); | |
2491 | } | |
2492 | else | |
2493 | { | |
2494 | /* Stmt no longer needs to be revisited. */ | |
2495 | gimple_set_plf (stmt, GF_PLF_1, true); | |
2496 | ||
2497 | /* Fill up the lattice. */ | |
2498 | if (gimple_assign_single_p (stmt)) | |
2499 | { | |
2500 | tree lhs = gimple_assign_lhs (stmt); | |
2501 | tree rhs = gimple_assign_rhs1 (stmt); | |
2502 | if (TREE_CODE (lhs) == SSA_NAME) | |
2503 | { | |
2504 | tree val = lhs; | |
2505 | if (TREE_CODE (rhs) == SSA_NAME) | |
2506 | val = fwprop_ssa_val (rhs); | |
2507 | else if (is_gimple_min_invariant (rhs)) | |
2508 | val = rhs; | |
2509 | fwprop_set_lattice_val (lhs, val); | |
2510 | } | |
2511 | } | |
2512 | ||
2513 | gsi_next (&gsi); | |
2514 | } | |
2515 | } | |
2516 | } | |
2517 | free (postorder); | |
2518 | lattice.release (); | |
2519 | ||
2520 | /* Fixup stmts that became noreturn calls. This may require splitting | |
2521 | blocks and thus isn't possible during the walk. Do this | |
2522 | in reverse order so we don't inadvertedly remove a stmt we want to | |
2523 | fixup by visiting a dominating now noreturn call first. */ | |
2524 | while (!to_fixup.is_empty ()) | |
2525 | { | |
2526 | gimple *stmt = to_fixup.pop (); | |
2527 | if (dump_file && dump_flags & TDF_DETAILS) | |
2528 | { | |
2529 | fprintf (dump_file, "Fixing up noreturn call "); | |
2530 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
2531 | fprintf (dump_file, "\n"); | |
2532 | } | |
2533 | cfg_changed |= fixup_noreturn_call (stmt); | |
2534 | } | |
2535 | ||
2536 | cfg_changed |= gimple_purge_all_dead_eh_edges (to_purge); | |
2537 | BITMAP_FREE (to_purge); | |
2538 | ||
2539 | if (cfg_changed) | |
2540 | todoflags |= TODO_cleanup_cfg; | |
2541 | ||
2542 | return todoflags; | |
2543 | } | |
2544 | ||
2545 | } // anon namespace | |
2546 | ||
2547 | gimple_opt_pass * | |
2548 | make_pass_forwprop (gcc::context *ctxt) | |
2549 | { | |
2550 | return new pass_forwprop (ctxt); | |
2551 | } |