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1 : : /* SSA Dominator optimizations for trees
2 : : Copyright (C) 2001-2024 Free Software Foundation, Inc.
3 : : Contributed by Diego Novillo <dnovillo@redhat.com>
4 : :
5 : : This file is part of GCC.
6 : :
7 : : GCC is free software; you can redistribute it and/or modify
8 : : it under the terms of the GNU General Public License as published by
9 : : the Free Software Foundation; either version 3, or (at your option)
10 : : any later version.
11 : :
12 : : GCC is distributed in the hope that it will be useful,
13 : : but WITHOUT ANY WARRANTY; without even the implied warranty of
14 : : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 : : GNU General Public License for more details.
16 : :
17 : : You should have received a copy of the GNU General Public License
18 : : along with GCC; see the file COPYING3. If not see
19 : : <http://www.gnu.org/licenses/>. */
20 : :
21 : : #include "config.h"
22 : : #include "system.h"
23 : : #include "coretypes.h"
24 : : #include "backend.h"
25 : : #include "tree.h"
26 : : #include "gimple.h"
27 : : #include "tree-pass.h"
28 : : #include "ssa.h"
29 : : #include "gimple-pretty-print.h"
30 : : #include "fold-const.h"
31 : : #include "cfganal.h"
32 : : #include "cfgloop.h"
33 : : #include "gimple-iterator.h"
34 : : #include "gimple-fold.h"
35 : : #include "tree-eh.h"
36 : : #include "tree-inline.h"
37 : : #include "tree-cfg.h"
38 : : #include "tree-into-ssa.h"
39 : : #include "domwalk.h"
40 : : #include "tree-ssa-propagate.h"
41 : : #include "tree-ssa-threadupdate.h"
42 : : #include "tree-ssa-scopedtables.h"
43 : : #include "tree-ssa-threadedge.h"
44 : : #include "tree-ssa-dom.h"
45 : : #include "gimplify.h"
46 : : #include "tree-cfgcleanup.h"
47 : : #include "dbgcnt.h"
48 : : #include "alloc-pool.h"
49 : : #include "tree-vrp.h"
50 : : #include "vr-values.h"
51 : : #include "gimple-range.h"
52 : : #include "gimple-range-path.h"
53 : : #include "alias.h"
54 : :
55 : : /* This file implements optimizations on the dominator tree. */
56 : :
57 : : /* Structure for recording edge equivalences.
58 : :
59 : : Computing and storing the edge equivalences instead of creating
60 : : them on-demand can save significant amounts of time, particularly
61 : : for pathological cases involving switch statements.
62 : :
63 : : These structures live for a single iteration of the dominator
64 : : optimizer in the edge's AUX field. At the end of an iteration we
65 : : free each of these structures. */
66 : : class edge_info
67 : : {
68 : : public:
69 : : typedef std::pair <tree, tree> equiv_pair;
70 : : edge_info (edge);
71 : : ~edge_info ();
72 : :
73 : : /* Record a simple LHS = RHS equivalence. This may trigger
74 : : calls to derive_equivalences. */
75 : : void record_simple_equiv (tree, tree);
76 : :
77 : : /* If traversing this edge creates simple equivalences, we store
78 : : them as LHS/RHS pairs within this vector. */
79 : : vec<equiv_pair> simple_equivalences;
80 : :
81 : : /* Traversing an edge may also indicate one or more particular conditions
82 : : are true or false. */
83 : : vec<cond_equivalence> cond_equivalences;
84 : :
85 : : private:
86 : : /* Derive equivalences by walking the use-def chains. */
87 : : void derive_equivalences (tree, tree, int);
88 : : };
89 : :
90 : : /* Track whether or not we have changed the control flow graph. */
91 : : static bool cfg_altered;
92 : :
93 : : /* Bitmap of blocks that have had EH statements cleaned. We should
94 : : remove their dead edges eventually. */
95 : : static bitmap need_eh_cleanup;
96 : : static vec<gimple *> need_noreturn_fixup;
97 : :
98 : : /* Statistics for dominator optimizations. */
99 : : struct opt_stats_d
100 : : {
101 : : long num_stmts;
102 : : long num_exprs_considered;
103 : : long num_re;
104 : : long num_const_prop;
105 : : long num_copy_prop;
106 : : };
107 : :
108 : : static struct opt_stats_d opt_stats;
109 : :
110 : : /* Local functions. */
111 : : static void record_equality (tree, tree, class const_and_copies *);
112 : : static void record_equivalences_from_phis (basic_block);
113 : : static void record_equivalences_from_incoming_edge (basic_block,
114 : : class const_and_copies *,
115 : : class avail_exprs_stack *,
116 : : bitmap blocks_on_stack);
117 : : static void eliminate_redundant_computations (gimple_stmt_iterator *,
118 : : class const_and_copies *,
119 : : class avail_exprs_stack *);
120 : : static void record_equivalences_from_stmt (gimple *, int,
121 : : class avail_exprs_stack *);
122 : : static void dump_dominator_optimization_stats (FILE *file,
123 : : hash_table<expr_elt_hasher> *);
124 : : static void record_temporary_equivalences (edge, class const_and_copies *,
125 : : class avail_exprs_stack *, bitmap);
126 : :
127 : : /* Constructor for EDGE_INFO. An EDGE_INFO instance is always
128 : : associated with an edge E. */
129 : :
130 : 33074769 : edge_info::edge_info (edge e)
131 : : {
132 : : /* Free the old one associated with E, if it exists and
133 : : associate our new object with E. */
134 : 33074769 : free_dom_edge_info (e);
135 : 33074769 : e->aux = this;
136 : :
137 : : /* And initialize the embedded vectors. */
138 : 33074769 : simple_equivalences = vNULL;
139 : 33074769 : cond_equivalences = vNULL;
140 : 33074769 : }
141 : :
142 : : /* Destructor just needs to release the vectors. */
143 : :
144 : 33074769 : edge_info::~edge_info (void)
145 : : {
146 : 33074769 : this->cond_equivalences.release ();
147 : 33074769 : this->simple_equivalences.release ();
148 : 33074769 : }
149 : :
150 : : /* NAME is known to have the value VALUE, which must be a constant.
151 : :
152 : : Walk through its use-def chain to see if there are other equivalences
153 : : we might be able to derive.
154 : :
155 : : RECURSION_LIMIT controls how far back we recurse through the use-def
156 : : chains. */
157 : :
158 : : void
159 : 12452432 : edge_info::derive_equivalences (tree name, tree value, int recursion_limit)
160 : : {
161 : 14315909 : if (TREE_CODE (name) != SSA_NAME || TREE_CODE (value) != INTEGER_CST)
162 : : return;
163 : :
164 : : /* This records the equivalence for the toplevel object. Do
165 : : this before checking the recursion limit. */
166 : 14315685 : simple_equivalences.safe_push (equiv_pair (name, value));
167 : :
168 : : /* Limit how far up the use-def chains we are willing to walk. */
169 : 14315685 : if (recursion_limit == 0)
170 : : return;
171 : :
172 : : /* We can walk up the use-def chains to potentially find more
173 : : equivalences. */
174 : 14301426 : gimple *def_stmt = SSA_NAME_DEF_STMT (name);
175 : 14301426 : if (is_gimple_assign (def_stmt))
176 : : {
177 : 9245349 : enum tree_code code = gimple_assign_rhs_code (def_stmt);
178 : 9245349 : switch (code)
179 : : {
180 : : /* If the result of an OR is zero, then its operands are, too. */
181 : 600679 : case BIT_IOR_EXPR:
182 : 600679 : if (integer_zerop (value))
183 : : {
184 : 329571 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
185 : 329571 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
186 : :
187 : 329571 : value = build_zero_cst (TREE_TYPE (rhs1));
188 : 329571 : derive_equivalences (rhs1, value, recursion_limit - 1);
189 : 329571 : value = build_zero_cst (TREE_TYPE (rhs2));
190 : 329571 : derive_equivalences (rhs2, value, recursion_limit - 1);
191 : : }
192 : : break;
193 : :
194 : : /* If the result of an AND is nonzero, then its operands are, too. */
195 : 1029098 : case BIT_AND_EXPR:
196 : 1029098 : if (!integer_zerop (value))
197 : : {
198 : 421395 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
199 : 421395 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
200 : :
201 : : /* If either operand has a boolean range, then we
202 : : know its value must be one, otherwise we just know it
203 : : is nonzero. The former is clearly useful, I haven't
204 : : seen cases where the latter is helpful yet. */
205 : 421395 : if (TREE_CODE (rhs1) == SSA_NAME)
206 : : {
207 : 421395 : if (ssa_name_has_boolean_range (rhs1))
208 : : {
209 : 263036 : value = build_one_cst (TREE_TYPE (rhs1));
210 : 263036 : derive_equivalences (rhs1, value, recursion_limit - 1);
211 : : }
212 : : }
213 : 421395 : if (TREE_CODE (rhs2) == SSA_NAME)
214 : : {
215 : 265050 : if (ssa_name_has_boolean_range (rhs2))
216 : : {
217 : 262796 : value = build_one_cst (TREE_TYPE (rhs2));
218 : 262796 : derive_equivalences (rhs2, value, recursion_limit - 1);
219 : : }
220 : : }
221 : : }
222 : : break;
223 : :
224 : : /* If LHS is an SSA_NAME and RHS is a constant integer and LHS was
225 : : set via a widening type conversion, then we may be able to record
226 : : additional equivalences. */
227 : 375406 : CASE_CONVERT:
228 : 375406 : {
229 : 375406 : tree rhs = gimple_assign_rhs1 (def_stmt);
230 : 375406 : tree rhs_type = TREE_TYPE (rhs);
231 : 375406 : if (INTEGRAL_TYPE_P (rhs_type)
232 : 373399 : && (TYPE_PRECISION (TREE_TYPE (name))
233 : 373399 : >= TYPE_PRECISION (rhs_type))
234 : 556681 : && int_fits_type_p (value, rhs_type))
235 : 172950 : derive_equivalences (rhs,
236 : : fold_convert (rhs_type, value),
237 : : recursion_limit - 1);
238 : : break;
239 : : }
240 : :
241 : : /* We can invert the operation of these codes trivially if
242 : : one of the RHS operands is a constant to produce a known
243 : : value for the other RHS operand. */
244 : 924253 : case POINTER_PLUS_EXPR:
245 : 924253 : case PLUS_EXPR:
246 : 924253 : {
247 : 924253 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
248 : 924253 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
249 : :
250 : : /* If either argument is a constant, then we can compute
251 : : a constant value for the nonconstant argument. */
252 : 924253 : if (TREE_CODE (rhs1) == INTEGER_CST
253 : 0 : && TREE_CODE (rhs2) == SSA_NAME)
254 : 0 : derive_equivalences (rhs2,
255 : 0 : fold_binary (MINUS_EXPR, TREE_TYPE (rhs1),
256 : : value, rhs1),
257 : : recursion_limit - 1);
258 : 924253 : else if (TREE_CODE (rhs2) == INTEGER_CST
259 : 880380 : && TREE_CODE (rhs1) == SSA_NAME)
260 : 880380 : derive_equivalences (rhs1,
261 : 880380 : fold_binary (MINUS_EXPR, TREE_TYPE (rhs1),
262 : : value, rhs2),
263 : : recursion_limit - 1);
264 : : break;
265 : : }
266 : :
267 : : /* If one of the operands is a constant, then we can compute
268 : : the value of the other operand. If both operands are
269 : : SSA_NAMEs, then they must be equal if the result is zero. */
270 : 64866 : case MINUS_EXPR:
271 : 64866 : {
272 : 64866 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
273 : 64866 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
274 : :
275 : : /* If either argument is a constant, then we can compute
276 : : a constant value for the nonconstant argument. */
277 : 64866 : if (TREE_CODE (rhs1) == INTEGER_CST
278 : 392 : && TREE_CODE (rhs2) == SSA_NAME)
279 : 392 : derive_equivalences (rhs2,
280 : 392 : fold_binary (MINUS_EXPR, TREE_TYPE (rhs1),
281 : : rhs1, value),
282 : : recursion_limit - 1);
283 : 64474 : else if (TREE_CODE (rhs2) == INTEGER_CST
284 : 26886 : && TREE_CODE (rhs1) == SSA_NAME)
285 : 26886 : derive_equivalences (rhs1,
286 : 26886 : fold_binary (PLUS_EXPR, TREE_TYPE (rhs1),
287 : : value, rhs2),
288 : : recursion_limit - 1);
289 : 37588 : else if (integer_zerop (value))
290 : : {
291 : 16609 : tree cond = build2 (EQ_EXPR, boolean_type_node,
292 : : gimple_assign_rhs1 (def_stmt),
293 : : gimple_assign_rhs2 (def_stmt));
294 : 16609 : tree inverted = invert_truthvalue (cond);
295 : 16609 : record_conditions (&this->cond_equivalences, cond, inverted);
296 : : }
297 : : break;
298 : : }
299 : :
300 : 672481 : case EQ_EXPR:
301 : 672481 : case NE_EXPR:
302 : 672481 : {
303 : 276573 : if ((code == EQ_EXPR && integer_onep (value))
304 : 804266 : || (code == NE_EXPR && integer_zerop (value)))
305 : : {
306 : 396519 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
307 : 396519 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
308 : :
309 : : /* If either argument is a constant, then record the
310 : : other argument as being the same as that constant.
311 : :
312 : : If neither operand is a constant, then we have a
313 : : conditional name == name equivalence. */
314 : 396519 : if (TREE_CODE (rhs1) == INTEGER_CST)
315 : 0 : derive_equivalences (rhs2, rhs1, recursion_limit - 1);
316 : 396519 : else if (TREE_CODE (rhs2) == INTEGER_CST)
317 : 175256 : derive_equivalences (rhs1, rhs2, recursion_limit - 1);
318 : : }
319 : : else
320 : : {
321 : 275962 : tree cond = build2 (code, boolean_type_node,
322 : : gimple_assign_rhs1 (def_stmt),
323 : 275962 : gimple_assign_rhs2 (def_stmt));
324 : 275962 : tree inverted = invert_truthvalue (cond);
325 : 275962 : if (integer_zerop (value))
326 : 131785 : std::swap (cond, inverted);
327 : 275962 : record_conditions (&this->cond_equivalences, cond, inverted);
328 : : }
329 : : break;
330 : : }
331 : :
332 : : /* For BIT_NOT and NEGATE, we can just apply the operation to the
333 : : VALUE to get the new equivalence. It will always be a constant
334 : : so we can recurse. */
335 : 15246 : case BIT_NOT_EXPR:
336 : 15246 : case NEGATE_EXPR:
337 : 15246 : {
338 : 15246 : tree rhs = gimple_assign_rhs1 (def_stmt);
339 : 15246 : tree res;
340 : : /* If this is a NOT and the operand has a boolean range, then we
341 : : know its value must be zero or one. We are not supposed to
342 : : have a BIT_NOT_EXPR for boolean types with precision > 1 in
343 : : the general case, see e.g. the handling of TRUTH_NOT_EXPR in
344 : : the gimplifier, but it can be generated by match.pd out of
345 : : a BIT_XOR_EXPR wrapped in a BIT_AND_EXPR. Now the handling
346 : : of BIT_AND_EXPR above already forces a specific semantics for
347 : : boolean types with precision > 1 so we must do the same here,
348 : : otherwise we could change the semantics of TRUTH_NOT_EXPR for
349 : : boolean types with precision > 1. */
350 : 15246 : if (code == BIT_NOT_EXPR
351 : 15063 : && TREE_CODE (rhs) == SSA_NAME
352 : 30309 : && ssa_name_has_boolean_range (rhs))
353 : : {
354 : 14691 : if ((TREE_INT_CST_LOW (value) & 1) == 0)
355 : 7779 : res = build_one_cst (TREE_TYPE (rhs));
356 : : else
357 : 6912 : res = build_zero_cst (TREE_TYPE (rhs));
358 : : }
359 : : else
360 : 555 : res = fold_build1 (code, TREE_TYPE (rhs), value);
361 : 15246 : derive_equivalences (rhs, res, recursion_limit - 1);
362 : 15246 : break;
363 : : }
364 : :
365 : 5563320 : default:
366 : 5563320 : {
367 : 5563320 : if (TREE_CODE_CLASS (code) == tcc_comparison)
368 : : {
369 : 545066 : tree cond = build2 (code, boolean_type_node,
370 : : gimple_assign_rhs1 (def_stmt),
371 : 545066 : gimple_assign_rhs2 (def_stmt));
372 : 545066 : tree inverted = invert_truthvalue (cond);
373 : 545066 : if (integer_zerop (value))
374 : 245189 : std::swap (cond, inverted);
375 : 545066 : record_conditions (&this->cond_equivalences, cond, inverted);
376 : 545066 : break;
377 : : }
378 : : break;
379 : : }
380 : : }
381 : : }
382 : : }
383 : :
384 : : void
385 : 14648061 : edge_info::record_simple_equiv (tree lhs, tree rhs)
386 : : {
387 : : /* If the RHS is a constant, then we may be able to derive
388 : : further equivalences. Else just record the name = name
389 : : equivalence. */
390 : 14648061 : if (TREE_CODE (rhs) == INTEGER_CST)
391 : 11859825 : derive_equivalences (lhs, rhs, 4);
392 : : else
393 : 2788236 : simple_equivalences.safe_push (equiv_pair (lhs, rhs));
394 : 14648061 : }
395 : :
396 : : /* Free the edge_info data attached to E, if it exists and
397 : : clear e->aux. */
398 : :
399 : : void
400 : 121766191 : free_dom_edge_info (edge e)
401 : : {
402 : 121766191 : class edge_info *edge_info = (class edge_info *)e->aux;
403 : :
404 : 121766191 : if (edge_info)
405 : 33074769 : delete edge_info;
406 : 121766191 : e->aux = NULL;
407 : 121766191 : }
408 : :
409 : : /* Free all EDGE_INFO structures associated with edges in the CFG.
410 : : If a particular edge can be threaded, copy the redirection
411 : : target from the EDGE_INFO structure into the edge's AUX field
412 : : as required by code to update the CFG and SSA graph for
413 : : jump threading. */
414 : :
415 : : static void
416 : 1992625 : free_all_edge_infos (void)
417 : : {
418 : 1992625 : basic_block bb;
419 : 1992625 : edge_iterator ei;
420 : 1992625 : edge e;
421 : :
422 : 22161299 : FOR_EACH_BB_FN (bb, cfun)
423 : : {
424 : 48622313 : FOR_EACH_EDGE (e, ei, bb->preds)
425 : 28453639 : free_dom_edge_info (e);
426 : : }
427 : 1992625 : }
428 : :
429 : : /* Return TRUE if BB has precisely two preds, one of which
430 : : is a backedge from a forwarder block where the forwarder
431 : : block is a direct successor of BB. Being a forwarder
432 : : block, it has no side effects other than transfer of
433 : : control. Otherwise return FALSE. */
434 : :
435 : : static bool
436 : 16526612 : single_block_loop_p (basic_block bb)
437 : : {
438 : : /* Two preds. */
439 : 16526612 : if (EDGE_COUNT (bb->preds) != 2)
440 : : return false;
441 : :
442 : : /* One and only one of the edges must be marked with
443 : : EDGE_DFS_BACK. */
444 : 4844361 : basic_block pred = NULL;
445 : 4844361 : unsigned int count = 0;
446 : 4844361 : if (EDGE_PRED (bb, 0)->flags & EDGE_DFS_BACK)
447 : : {
448 : 1674193 : pred = EDGE_PRED (bb, 0)->src;
449 : 1674193 : count++;
450 : : }
451 : 4844361 : if (EDGE_PRED (bb, 1)->flags & EDGE_DFS_BACK)
452 : : {
453 : 390195 : pred = EDGE_PRED (bb, 1)->src;
454 : 390195 : count++;
455 : : }
456 : :
457 : 4844361 : if (count != 1)
458 : : return false;
459 : :
460 : : /* Now examine PRED. It should have a single predecessor which
461 : : is BB and a single successor that is also BB. */
462 : 2064388 : if (EDGE_COUNT (pred->preds) != 1
463 : 17571888 : || EDGE_COUNT (pred->succs) != 1
464 : 1996922 : || EDGE_PRED (pred, 0)->src != bb
465 : 3084977 : || EDGE_SUCC (pred, 0)->dest != bb)
466 : : return false;
467 : :
468 : : /* This looks good from a CFG standpoint. Now look at the guts
469 : : of PRED. Basically we want to verify there are no PHI nodes
470 : : and no real statements. */
471 : 1020589 : if (! gimple_seq_empty_p (phi_nodes (pred)))
472 : : return false;
473 : :
474 : 1015489 : gimple_stmt_iterator gsi;
475 : 2084152 : for (gsi = gsi_last_bb (pred); !gsi_end_p (gsi); gsi_prev (&gsi))
476 : : {
477 : 90430 : gimple *stmt = gsi_stmt (gsi);
478 : :
479 : 90430 : switch (gimple_code (stmt))
480 : : {
481 : 0 : case GIMPLE_LABEL:
482 : 0 : if (DECL_NONLOCAL (gimple_label_label (as_a <glabel *> (stmt))))
483 : : return false;
484 : : break;
485 : :
486 : : case GIMPLE_DEBUG:
487 : : break;
488 : :
489 : : default:
490 : : return false;
491 : : }
492 : : }
493 : :
494 : : return true;
495 : : }
496 : :
497 : : /* We have finished optimizing BB, record any information implied by
498 : : taking a specific outgoing edge from BB. */
499 : :
500 : : static void
501 : 42279842 : record_edge_info (basic_block bb)
502 : : {
503 : 42279842 : gimple_stmt_iterator gsi = gsi_last_bb (bb);
504 : 42279842 : class edge_info *edge_info;
505 : :
506 : : /* Free all the outgoing edge info data associated with
507 : : BB's outgoing edges. */
508 : 42279842 : edge e;
509 : 42279842 : edge_iterator ei;
510 : 101050045 : FOR_EACH_EDGE (e, ei, bb->succs)
511 : 58770203 : free_dom_edge_info (e);
512 : :
513 : 42279842 : if (! gsi_end_p (gsi))
514 : : {
515 : 36224752 : gimple *stmt = gsi_stmt (gsi);
516 : 36224752 : location_t loc = gimple_location (stmt);
517 : :
518 : 36224752 : if (gimple_code (stmt) == GIMPLE_SWITCH)
519 : : {
520 : 64746 : gswitch *switch_stmt = as_a <gswitch *> (stmt);
521 : 64746 : tree index = gimple_switch_index (switch_stmt);
522 : :
523 : 64746 : if (TREE_CODE (index) == SSA_NAME)
524 : : {
525 : 64734 : int i;
526 : 64734 : int n_labels = gimple_switch_num_labels (switch_stmt);
527 : 64734 : tree *info = XCNEWVEC (tree, last_basic_block_for_fn (cfun));
528 : :
529 : 564044 : for (i = 0; i < n_labels; i++)
530 : : {
531 : 499310 : tree label = gimple_switch_label (switch_stmt, i);
532 : 499310 : basic_block target_bb
533 : 499310 : = label_to_block (cfun, CASE_LABEL (label));
534 : 499310 : if (CASE_HIGH (label)
535 : 468563 : || !CASE_LOW (label)
536 : 903139 : || info[target_bb->index])
537 : 149469 : info[target_bb->index] = error_mark_node;
538 : : else
539 : 349841 : info[target_bb->index] = label;
540 : : }
541 : :
542 : 502886 : FOR_EACH_EDGE (e, ei, bb->succs)
543 : : {
544 : 438152 : basic_block target_bb = e->dest;
545 : 438152 : tree label = info[target_bb->index];
546 : :
547 : 438152 : if (label != NULL && label != error_mark_node)
548 : : {
549 : 640446 : tree x = fold_convert_loc (loc, TREE_TYPE (index),
550 : 320223 : CASE_LOW (label));
551 : 320223 : edge_info = new class edge_info (e);
552 : 320223 : edge_info->record_simple_equiv (index, x);
553 : : }
554 : : }
555 : 64734 : free (info);
556 : : }
557 : : }
558 : :
559 : : /* A COND_EXPR may create equivalences too. */
560 : 36224752 : if (gimple_code (stmt) == GIMPLE_COND)
561 : : {
562 : 16526612 : edge true_edge;
563 : 16526612 : edge false_edge;
564 : :
565 : 16526612 : tree op0 = gimple_cond_lhs (stmt);
566 : 16526612 : tree op1 = gimple_cond_rhs (stmt);
567 : 16526612 : enum tree_code code = gimple_cond_code (stmt);
568 : :
569 : 16526612 : extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
570 : :
571 : : /* Special case comparing booleans against a constant as we
572 : : know the value of OP0 on both arms of the branch. i.e., we
573 : : can record an equivalence for OP0 rather than COND.
574 : :
575 : : However, don't do this if the constant isn't zero or one.
576 : : Such conditionals will get optimized more thoroughly during
577 : : the domwalk. */
578 : 16526612 : if ((code == EQ_EXPR || code == NE_EXPR)
579 : 12768257 : && TREE_CODE (op0) == SSA_NAME
580 : 12327840 : && ssa_name_has_boolean_range (op0)
581 : 1965044 : && is_gimple_min_invariant (op1)
582 : 18432055 : && (integer_zerop (op1) || integer_onep (op1)))
583 : : {
584 : 1905443 : tree true_val = constant_boolean_node (true, TREE_TYPE (op0));
585 : 1905443 : tree false_val = constant_boolean_node (false, TREE_TYPE (op0));
586 : :
587 : 1905443 : if (code == EQ_EXPR)
588 : : {
589 : 77299 : edge_info = new class edge_info (true_edge);
590 : 115538 : edge_info->record_simple_equiv (op0,
591 : 77299 : (integer_zerop (op1)
592 : : ? false_val : true_val));
593 : 77299 : edge_info = new class edge_info (false_edge);
594 : 115538 : edge_info->record_simple_equiv (op0,
595 : 77299 : (integer_zerop (op1)
596 : : ? true_val : false_val));
597 : : }
598 : : else
599 : : {
600 : 1828144 : edge_info = new class edge_info (true_edge);
601 : 1849000 : edge_info->record_simple_equiv (op0,
602 : 1828144 : (integer_zerop (op1)
603 : : ? true_val : false_val));
604 : 1828144 : edge_info = new class edge_info (false_edge);
605 : 1849000 : edge_info->record_simple_equiv (op0,
606 : 1828144 : (integer_zerop (op1)
607 : : ? false_val : true_val));
608 : : }
609 : : }
610 : : /* This can show up in the IL as a result of copy propagation
611 : : it will eventually be canonicalized, but we have to cope
612 : : with this case within the pass. */
613 : 14621169 : else if (is_gimple_min_invariant (op0)
614 : 14621169 : && TREE_CODE (op1) == SSA_NAME)
615 : : {
616 : 299163 : tree cond = build2 (code, boolean_type_node, op0, op1);
617 : 299163 : tree inverted = invert_truthvalue_loc (loc, cond);
618 : 299163 : bool can_infer_simple_equiv
619 : 299163 : = !(HONOR_SIGNED_ZEROS (op0) && real_maybe_zerop (op0))
620 : 299163 : && !DECIMAL_FLOAT_MODE_P (element_mode (TREE_TYPE (op0)));
621 : 299163 : class edge_info *edge_info;
622 : :
623 : 299163 : edge_info = new class edge_info (true_edge);
624 : 299163 : record_conditions (&edge_info->cond_equivalences, cond, inverted);
625 : :
626 : 299163 : if (can_infer_simple_equiv && code == EQ_EXPR)
627 : 235148 : edge_info->record_simple_equiv (op1, op0);
628 : :
629 : 299163 : edge_info = new class edge_info (false_edge);
630 : 299163 : record_conditions (&edge_info->cond_equivalences, inverted, cond);
631 : :
632 : 299163 : if (can_infer_simple_equiv && TREE_CODE (inverted) == EQ_EXPR)
633 : 56084 : edge_info->record_simple_equiv (op1, op0);
634 : : }
635 : :
636 : 14322006 : else if (TREE_CODE (op0) == SSA_NAME
637 : 14322006 : && (TREE_CODE (op1) == SSA_NAME
638 : 10599760 : || is_gimple_min_invariant (op1)))
639 : : {
640 : 14172311 : tree cond = build2 (code, boolean_type_node, op0, op1);
641 : 14172311 : tree inverted = invert_truthvalue_loc (loc, cond);
642 : 14172311 : bool can_infer_simple_equiv
643 : 14849591 : = !(HONOR_SIGNED_ZEROS (op1) && real_maybe_zerop (op1))
644 : 14564786 : && !DECIMAL_FLOAT_MODE_P (element_mode (TREE_TYPE (op1)));
645 : 14172311 : class edge_info *edge_info;
646 : :
647 : 14172311 : edge_info = new class edge_info (true_edge);
648 : 14172311 : record_conditions (&edge_info->cond_equivalences, cond, inverted);
649 : :
650 : 14172311 : if (can_infer_simple_equiv && code == EQ_EXPR)
651 : 4577598 : edge_info->record_simple_equiv (op0, op1);
652 : :
653 : 14172311 : edge_info = new class edge_info (false_edge);
654 : 14172311 : record_conditions (&edge_info->cond_equivalences, inverted, cond);
655 : :
656 : 14172311 : if (can_infer_simple_equiv && TREE_CODE (inverted) == EQ_EXPR)
657 : 5646504 : edge_info->record_simple_equiv (op0, op1);
658 : : }
659 : :
660 : : /* If this block is a single block loop, then we may be able to
661 : : record some equivalences on the loop's exit edge. */
662 : 16526612 : if (single_block_loop_p (bb))
663 : : {
664 : : /* We know it's a single block loop. Now look at the loop
665 : : exit condition. What we're looking for is whether or not
666 : : the exit condition is loop invariant which we can detect
667 : : by checking if all the SSA_NAMEs referenced are defined
668 : : outside the loop. */
669 : 951646 : if ((TREE_CODE (op0) != SSA_NAME
670 : 945616 : || gimple_bb (SSA_NAME_DEF_STMT (op0)) != bb)
671 : 1092933 : && (TREE_CODE (op1) != SSA_NAME
672 : 145024 : || gimple_bb (SSA_NAME_DEF_STMT (op1)) != bb))
673 : : {
674 : : /* At this point we know the exit condition is loop
675 : : invariant. The only way to get out of the loop is
676 : : if it never traverses the backedge to begin with. This
677 : : implies that any PHI nodes create equivalances that we
678 : : can attach to the loop exit edge. */
679 : 2412 : bool alternative
680 : 2412 : = (EDGE_PRED (bb, 0)->flags & EDGE_DFS_BACK) ? 1 : 0;
681 : :
682 : 2412 : gphi_iterator gsi;
683 : 2412 : for (gsi = gsi_start_phis (bb);
684 : 4274 : !gsi_end_p (gsi);
685 : 1862 : gsi_next (&gsi))
686 : : {
687 : : /* Now get the EDGE_INFO class so we can append
688 : : it to our list. We want the successor edge
689 : : where the destination is not the source of
690 : : an incoming edge. */
691 : 1862 : gphi *phi = gsi.phi ();
692 : 1862 : tree src = PHI_ARG_DEF (phi, alternative);
693 : 1862 : tree dst = PHI_RESULT (phi);
694 : :
695 : : /* If the other alternative is the same as the result,
696 : : then this is a degenerate and can be ignored. */
697 : 1862 : if (dst == PHI_ARG_DEF (phi, !alternative))
698 : 244 : continue;
699 : :
700 : 1618 : if (EDGE_SUCC (bb, 0)->dest
701 : 1618 : != EDGE_PRED (bb, !alternative)->src)
702 : 276 : edge_info = (class edge_info *)EDGE_SUCC (bb, 0)->aux;
703 : : else
704 : 1342 : edge_info = (class edge_info *)EDGE_SUCC (bb, 1)->aux;
705 : :
706 : : /* Note that since this processing is done independently
707 : : of other edge equivalency processing, we may not
708 : : have an EDGE_INFO structure set up yet. */
709 : 1618 : if (edge_info == NULL)
710 : 712 : edge_info = new class edge_info (false_edge);
711 : 1618 : edge_info->record_simple_equiv (dst, src);
712 : : }
713 : : }
714 : : }
715 : : }
716 : : }
717 : 42279842 : }
718 : :
719 : : class dom_jt_state : public jt_state
720 : : {
721 : : public:
722 : 1992625 : dom_jt_state (const_and_copies *copies, avail_exprs_stack *avails)
723 : 1992625 : : m_copies (copies), m_avails (avails)
724 : : {
725 : 1992625 : bitmap_tree_view (m_blocks_on_stack);
726 : 1992625 : }
727 : 15812358 : void push (edge e) override
728 : : {
729 : 15812358 : m_copies->push_marker ();
730 : 15812358 : m_avails->push_marker ();
731 : 15812358 : jt_state::push (e);
732 : 15812358 : }
733 : 15812358 : void pop () override
734 : : {
735 : 15812358 : m_copies->pop_to_marker ();
736 : 15812358 : m_avails->pop_to_marker ();
737 : 15812358 : jt_state::pop ();
738 : 15812358 : }
739 : 14682472 : void register_equivs_edge (edge e) override
740 : : {
741 : 14682472 : record_temporary_equivalences (e, m_copies, m_avails, m_blocks_on_stack);
742 : 14682472 : }
743 : : void register_equiv (tree dest, tree src, bool update) override;
744 : 66333504 : bitmap get_blocks_on_stack () { return m_blocks_on_stack; }
745 : : private:
746 : : const_and_copies *m_copies;
747 : : avail_exprs_stack *m_avails;
748 : : /* Set of blocks on the stack, to be used for medium-fast
749 : : dominance queries in back_propagate_equivalences. */
750 : : auto_bitmap m_blocks_on_stack;
751 : : };
752 : :
753 : : void
754 : 20508446 : dom_jt_state::register_equiv (tree dest, tree src, bool)
755 : : {
756 : 20508446 : m_copies->record_const_or_copy (dest, src);
757 : 20508446 : }
758 : :
759 : 1992625 : class dom_jt_simplifier : public hybrid_jt_simplifier
760 : : {
761 : : public:
762 : 1992625 : dom_jt_simplifier (avail_exprs_stack *avails, gimple_ranger *ranger,
763 : : path_range_query *query)
764 : 3985250 : : hybrid_jt_simplifier (ranger, query), m_avails (avails) { }
765 : :
766 : : private:
767 : : tree simplify (gimple *, gimple *, basic_block, jt_state *) override;
768 : : avail_exprs_stack *m_avails;
769 : : };
770 : :
771 : : tree
772 : 27967581 : dom_jt_simplifier::simplify (gimple *stmt, gimple *within_stmt,
773 : : basic_block bb, jt_state *state)
774 : : {
775 : : /* First see if the conditional is in the hash table. */
776 : 27967581 : tree cached_lhs = m_avails->lookup_avail_expr (stmt, false, true);
777 : 27967581 : if (cached_lhs)
778 : : return cached_lhs;
779 : :
780 : : /* Otherwise call the ranger if possible. */
781 : 27312314 : if (state)
782 : 7523588 : return hybrid_jt_simplifier::simplify (stmt, within_stmt, bb, state);
783 : :
784 : : return NULL;
785 : : }
786 : :
787 : 3985250 : class dom_opt_dom_walker : public dom_walker
788 : : {
789 : : public:
790 : 1992625 : dom_opt_dom_walker (cdi_direction direction,
791 : : jump_threader *threader,
792 : : dom_jt_state *state,
793 : : gimple_ranger *ranger,
794 : : const_and_copies *const_and_copies,
795 : : avail_exprs_stack *avail_exprs_stack)
796 : 1992625 : : dom_walker (direction, REACHABLE_BLOCKS)
797 : : {
798 : 1992625 : m_ranger = ranger;
799 : 1992625 : m_state = state;
800 : 1992625 : m_dummy_cond = gimple_build_cond (NE_EXPR, integer_zero_node,
801 : : integer_zero_node, NULL, NULL);
802 : 1992625 : m_const_and_copies = const_and_copies;
803 : 1992625 : m_avail_exprs_stack = avail_exprs_stack;
804 : 1992625 : m_threader = threader;
805 : 1992625 : }
806 : :
807 : : edge before_dom_children (basic_block) final override;
808 : : void after_dom_children (basic_block) final override;
809 : :
810 : : private:
811 : :
812 : : /* Unwindable equivalences, both const/copy and expression varieties. */
813 : : class const_and_copies *m_const_and_copies;
814 : : class avail_exprs_stack *m_avail_exprs_stack;
815 : :
816 : : /* Dummy condition to avoid creating lots of throw away statements. */
817 : : gcond *m_dummy_cond;
818 : :
819 : : /* Optimize a single statement within a basic block using the
820 : : various tables mantained by DOM. Returns the taken edge if
821 : : the statement is a conditional with a statically determined
822 : : value. */
823 : : edge optimize_stmt (basic_block, gimple_stmt_iterator *, bool *);
824 : :
825 : : void set_global_ranges_from_unreachable_edges (basic_block);
826 : :
827 : : void test_for_singularity (gimple *, avail_exprs_stack *);
828 : : edge fold_cond (gcond *cond);
829 : :
830 : : jump_threader *m_threader;
831 : : gimple_ranger *m_ranger;
832 : : dom_jt_state *m_state;
833 : : };
834 : :
835 : : /* Jump threading, redundancy elimination and const/copy propagation.
836 : :
837 : : This pass may expose new symbols that need to be renamed into SSA. For
838 : : every new symbol exposed, its corresponding bit will be set in
839 : : VARS_TO_RENAME. */
840 : :
841 : : namespace {
842 : :
843 : : const pass_data pass_data_dominator =
844 : : {
845 : : GIMPLE_PASS, /* type */
846 : : "dom", /* name */
847 : : OPTGROUP_NONE, /* optinfo_flags */
848 : : TV_TREE_SSA_DOMINATOR_OPTS, /* tv_id */
849 : : ( PROP_cfg | PROP_ssa ), /* properties_required */
850 : : 0, /* properties_provided */
851 : : 0, /* properties_destroyed */
852 : : 0, /* todo_flags_start */
853 : : ( TODO_cleanup_cfg | TODO_update_ssa ), /* todo_flags_finish */
854 : : };
855 : :
856 : : class pass_dominator : public gimple_opt_pass
857 : : {
858 : : public:
859 : 840342 : pass_dominator (gcc::context *ctxt)
860 : 840342 : : gimple_opt_pass (pass_data_dominator, ctxt),
861 : 1680684 : may_peel_loop_headers_p (false)
862 : : {}
863 : :
864 : : /* opt_pass methods: */
865 : 560228 : opt_pass * clone () final override { return new pass_dominator (m_ctxt); }
866 : 840342 : void set_pass_param (unsigned int n, bool param) final override
867 : : {
868 : 840342 : gcc_assert (n == 0);
869 : 840342 : may_peel_loop_headers_p = param;
870 : 840342 : }
871 : 1993323 : bool gate (function *) final override { return flag_tree_dom != 0; }
872 : : unsigned int execute (function *) final override;
873 : :
874 : : private:
875 : : /* This flag is used to prevent loops from being peeled repeatedly in jump
876 : : threading; it will be removed once we preserve loop structures throughout
877 : : the compilation -- we will be able to mark the affected loops directly in
878 : : jump threading, and avoid peeling them next time. */
879 : : bool may_peel_loop_headers_p;
880 : : }; // class pass_dominator
881 : :
882 : : unsigned int
883 : 1992625 : pass_dominator::execute (function *fun)
884 : : {
885 : 1992625 : memset (&opt_stats, 0, sizeof (opt_stats));
886 : :
887 : : /* Create our hash tables. */
888 : 1992625 : hash_table<expr_elt_hasher> *avail_exprs
889 : 1992625 : = new hash_table<expr_elt_hasher> (1024);
890 : 1992625 : class avail_exprs_stack *avail_exprs_stack
891 : 1992625 : = new class avail_exprs_stack (avail_exprs);
892 : 1992625 : class const_and_copies *const_and_copies = new class const_and_copies ();
893 : 1992625 : need_eh_cleanup = BITMAP_ALLOC (NULL);
894 : 1992625 : need_noreturn_fixup.create (0);
895 : :
896 : 1992625 : calculate_dominance_info (CDI_DOMINATORS);
897 : 1992625 : cfg_altered = false;
898 : :
899 : : /* We need to know loop structures in order to avoid destroying them
900 : : in jump threading. Note that we still can e.g. thread through loop
901 : : headers to an exit edge, or through loop header to the loop body, assuming
902 : : that we update the loop info.
903 : :
904 : : TODO: We don't need to set LOOPS_HAVE_PREHEADERS generally, but due
905 : : to several overly conservative bail-outs in jump threading, case
906 : : gcc.dg/tree-ssa/pr21417.c can't be threaded if loop preheader is
907 : : missing. We should improve jump threading in future then
908 : : LOOPS_HAVE_PREHEADERS won't be needed here. */
909 : 1992625 : loop_optimizer_init (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES
910 : : | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS);
911 : :
912 : : /* We need accurate information regarding back edges in the CFG
913 : : for jump threading; this may include back edges that are not part of
914 : : a single loop. */
915 : 1992625 : mark_dfs_back_edges ();
916 : :
917 : : /* We want to create the edge info structures before the dominator walk
918 : : so that they'll be in place for the jump threader, particularly when
919 : : threading through a join block.
920 : :
921 : : The conditions will be lazily updated with global equivalences as
922 : : we reach them during the dominator walk. */
923 : 1992625 : basic_block bb;
924 : 22161299 : FOR_EACH_BB_FN (bb, fun)
925 : 20168674 : record_edge_info (bb);
926 : :
927 : : /* Recursively walk the dominator tree optimizing statements. */
928 : 1992625 : gimple_ranger *ranger = enable_ranger (fun);
929 : 1992625 : path_range_query path_query (*ranger);
930 : 1992625 : dom_jt_simplifier simplifier (avail_exprs_stack, ranger, &path_query);
931 : 1992625 : dom_jt_state state (const_and_copies, avail_exprs_stack);
932 : 1992625 : jump_threader threader (&simplifier, &state);
933 : 1992625 : dom_opt_dom_walker walker (CDI_DOMINATORS,
934 : : &threader,
935 : : &state,
936 : : ranger,
937 : : const_and_copies,
938 : 1992625 : avail_exprs_stack);
939 : 1992625 : walker.walk (fun->cfg->x_entry_block_ptr);
940 : :
941 : 1992625 : ranger->export_global_ranges ();
942 : 1992625 : disable_ranger (fun);
943 : :
944 : : /* Look for blocks where we cleared EDGE_EXECUTABLE on an outgoing
945 : : edge. When found, remove jump threads which contain any outgoing
946 : : edge from the affected block. */
947 : 1992625 : if (cfg_altered)
948 : : {
949 : 3739635 : FOR_EACH_BB_FN (bb, fun)
950 : : {
951 : 3689228 : edge_iterator ei;
952 : 3689228 : edge e;
953 : :
954 : : /* First see if there are any edges without EDGE_EXECUTABLE
955 : : set. */
956 : 3689228 : bool found = false;
957 : 8842983 : FOR_EACH_EDGE (e, ei, bb->succs)
958 : : {
959 : 5328281 : if ((e->flags & EDGE_EXECUTABLE) == 0)
960 : : {
961 : : found = true;
962 : : break;
963 : : }
964 : : }
965 : :
966 : : /* If there were any such edges found, then remove jump threads
967 : : containing any edge leaving BB. */
968 : 3689228 : if (found)
969 : 507251 : FOR_EACH_EDGE (e, ei, bb->succs)
970 : 332725 : threader.remove_jump_threads_including (e);
971 : : }
972 : : }
973 : :
974 : 1992625 : {
975 : 1992625 : gimple_stmt_iterator gsi;
976 : 1992625 : basic_block bb;
977 : 22161299 : FOR_EACH_BB_FN (bb, fun)
978 : : {
979 : 189418115 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
980 : 149080767 : update_stmt_if_modified (gsi_stmt (gsi));
981 : : }
982 : : }
983 : :
984 : : /* If we exposed any new variables, go ahead and put them into
985 : : SSA form now, before we handle jump threading. This simplifies
986 : : interactions between rewriting of _DECL nodes into SSA form
987 : : and rewriting SSA_NAME nodes into SSA form after block
988 : : duplication and CFG manipulation. */
989 : 1992625 : update_ssa (TODO_update_ssa);
990 : :
991 : 1992625 : free_all_edge_infos ();
992 : :
993 : : /* Thread jumps, creating duplicate blocks as needed. */
994 : 1992625 : cfg_altered |= threader.thread_through_all_blocks (may_peel_loop_headers_p);
995 : :
996 : 1992625 : if (cfg_altered)
997 : 122554 : free_dominance_info (CDI_DOMINATORS);
998 : :
999 : : /* Removal of statements may make some EH edges dead. Purge
1000 : : such edges from the CFG as needed. */
1001 : 1992625 : if (!bitmap_empty_p (need_eh_cleanup))
1002 : : {
1003 : 777 : unsigned i;
1004 : 777 : bitmap_iterator bi;
1005 : :
1006 : : /* Jump threading may have created forwarder blocks from blocks
1007 : : needing EH cleanup; the new successor of these blocks, which
1008 : : has inherited from the original block, needs the cleanup.
1009 : : Don't clear bits in the bitmap, as that can break the bitmap
1010 : : iterator. */
1011 : 2340 : EXECUTE_IF_SET_IN_BITMAP (need_eh_cleanup, 0, i, bi)
1012 : : {
1013 : 1563 : basic_block bb = BASIC_BLOCK_FOR_FN (fun, i);
1014 : 1563 : if (bb == NULL)
1015 : 0 : continue;
1016 : 3160 : while (single_succ_p (bb)
1017 : 1611 : && (single_succ_edge (bb)->flags
1018 : 49 : & (EDGE_EH|EDGE_DFS_BACK)) == 0)
1019 : 48 : bb = single_succ (bb);
1020 : 1563 : if (bb == EXIT_BLOCK_PTR_FOR_FN (fun))
1021 : 14 : continue;
1022 : 1549 : if ((unsigned) bb->index != i)
1023 : 27 : bitmap_set_bit (need_eh_cleanup, bb->index);
1024 : : }
1025 : :
1026 : 777 : gimple_purge_all_dead_eh_edges (need_eh_cleanup);
1027 : 777 : bitmap_clear (need_eh_cleanup);
1028 : : }
1029 : :
1030 : : /* Fixup stmts that became noreturn calls. This may require splitting
1031 : : blocks and thus isn't possible during the dominator walk or before
1032 : : jump threading finished. Do this in reverse order so we don't
1033 : : inadvertedly remove a stmt we want to fixup by visiting a dominating
1034 : : now noreturn call first. */
1035 : 1992630 : while (!need_noreturn_fixup.is_empty ())
1036 : : {
1037 : 5 : gimple *stmt = need_noreturn_fixup.pop ();
1038 : 5 : if (dump_file && dump_flags & TDF_DETAILS)
1039 : : {
1040 : 0 : fprintf (dump_file, "Fixing up noreturn call ");
1041 : 0 : print_gimple_stmt (dump_file, stmt, 0);
1042 : 0 : fprintf (dump_file, "\n");
1043 : : }
1044 : 5 : fixup_noreturn_call (stmt);
1045 : : }
1046 : :
1047 : 1992625 : statistics_counter_event (fun, "Redundant expressions eliminated",
1048 : 1992625 : opt_stats.num_re);
1049 : 1992625 : statistics_counter_event (fun, "Constants propagated",
1050 : 1992625 : opt_stats.num_const_prop);
1051 : 1992625 : statistics_counter_event (fun, "Copies propagated",
1052 : 1992625 : opt_stats.num_copy_prop);
1053 : :
1054 : : /* Debugging dumps. */
1055 : 1992625 : if (dump_file && (dump_flags & TDF_STATS))
1056 : 35 : dump_dominator_optimization_stats (dump_file, avail_exprs);
1057 : :
1058 : 1992625 : loop_optimizer_finalize ();
1059 : :
1060 : : /* Delete our main hashtable. */
1061 : 1992625 : delete avail_exprs;
1062 : 1992625 : avail_exprs = NULL;
1063 : :
1064 : : /* Free asserted bitmaps and stacks. */
1065 : 1992625 : BITMAP_FREE (need_eh_cleanup);
1066 : 1992625 : need_noreturn_fixup.release ();
1067 : 1992625 : delete avail_exprs_stack;
1068 : 1992625 : delete const_and_copies;
1069 : :
1070 : 1992625 : return 0;
1071 : 1992625 : }
1072 : :
1073 : : } // anon namespace
1074 : :
1075 : : gimple_opt_pass *
1076 : 280114 : make_pass_dominator (gcc::context *ctxt)
1077 : : {
1078 : 280114 : return new pass_dominator (ctxt);
1079 : : }
1080 : :
1081 : : /* Valueize hook for gimple_fold_stmt_to_constant_1. */
1082 : :
1083 : : static tree
1084 : 31984428 : dom_valueize (tree t)
1085 : : {
1086 : 31984428 : if (TREE_CODE (t) == SSA_NAME)
1087 : : {
1088 : 22996369 : tree tem = SSA_NAME_VALUE (t);
1089 : 18171941 : if (tem)
1090 : 2829116 : return tem;
1091 : : }
1092 : : return t;
1093 : : }
1094 : :
1095 : : /* We have just found an equivalence for LHS on an edge E.
1096 : : Look backwards to other uses of LHS and see if we can derive
1097 : : additional equivalences that are valid on edge E. */
1098 : : static void
1099 : 11195502 : back_propagate_equivalences (tree lhs, edge e,
1100 : : class const_and_copies *const_and_copies,
1101 : : bitmap domby)
1102 : : {
1103 : 11195502 : use_operand_p use_p;
1104 : 11195502 : imm_use_iterator iter;
1105 : 11195502 : basic_block dest = e->dest;
1106 : 11195502 : bool domok = (dom_info_state (CDI_DOMINATORS) == DOM_OK);
1107 : :
1108 : : /* Iterate over the uses of LHS to see if any dominate E->dest.
1109 : : If so, they may create useful equivalences too.
1110 : :
1111 : : ??? If the code gets re-organized to a worklist to catch more
1112 : : indirect opportunities and it is made to handle PHIs then this
1113 : : should only consider use_stmts in basic-blocks we have already visited. */
1114 : 46145837 : FOR_EACH_IMM_USE_FAST (use_p, iter, lhs)
1115 : : {
1116 : 34950335 : gimple *use_stmt = USE_STMT (use_p);
1117 : :
1118 : : /* Often the use is in DEST, which we trivially know we can't use.
1119 : : This is cheaper than the dominator set tests below. */
1120 : 34950335 : if (dest == gimple_bb (use_stmt))
1121 : 361805 : continue;
1122 : :
1123 : : /* Filter out statements that can never produce a useful
1124 : : equivalence. */
1125 : 34588530 : tree lhs2 = gimple_get_lhs (use_stmt);
1126 : 34588530 : if (!lhs2 || TREE_CODE (lhs2) != SSA_NAME)
1127 : 25389855 : continue;
1128 : :
1129 : 9198675 : if (domok)
1130 : : {
1131 : 5652477 : if (!dominated_by_p (CDI_DOMINATORS, dest, gimple_bb (use_stmt)))
1132 : 2930699 : continue;
1133 : : }
1134 : : else
1135 : : {
1136 : : /* We can use the set of BBs on the stack from a domwalk
1137 : : for a medium fast way to query dominance. Profiling
1138 : : has shown non-fast query dominance tests here can be fairly
1139 : : expensive. */
1140 : : /* This tests if USE_STMT does not dominate DEST. */
1141 : 3546198 : if (!bitmap_bit_p (domby, gimple_bb (use_stmt)->index))
1142 : 2627527 : continue;
1143 : : }
1144 : :
1145 : : /* At this point USE_STMT dominates DEST and may result in a
1146 : : useful equivalence. Try to simplify its RHS to a constant
1147 : : or SSA_NAME. */
1148 : 3640449 : tree res = gimple_fold_stmt_to_constant_1 (use_stmt, dom_valueize,
1149 : : no_follow_ssa_edges);
1150 : 3640449 : if (res && (TREE_CODE (res) == SSA_NAME || is_gimple_min_invariant (res)))
1151 : 2183226 : record_equality (lhs2, res, const_and_copies);
1152 : : }
1153 : 11195502 : }
1154 : :
1155 : : /* Record into CONST_AND_COPIES and AVAIL_EXPRS_STACK any equivalences implied
1156 : : by traversing edge E (which are cached in E->aux).
1157 : :
1158 : : Callers are responsible for managing the unwinding markers. */
1159 : : static void
1160 : 31037277 : record_temporary_equivalences (edge e,
1161 : : class const_and_copies *const_and_copies,
1162 : : class avail_exprs_stack *avail_exprs_stack,
1163 : : bitmap blocks_on_stack)
1164 : : {
1165 : 31037277 : int i;
1166 : 31037277 : class edge_info *edge_info = (class edge_info *) e->aux;
1167 : :
1168 : : /* If we have info associated with this edge, record it into
1169 : : our equivalence tables. */
1170 : 31037277 : if (edge_info)
1171 : : {
1172 : : cond_equivalence *eq;
1173 : : /* If we have 0 = COND or 1 = COND equivalences, record them
1174 : : into our expression hash tables. */
1175 : 82729504 : for (i = 0; edge_info->cond_equivalences.iterate (i, &eq); ++i)
1176 : 61077851 : avail_exprs_stack->record_cond (eq);
1177 : :
1178 : : edge_info::equiv_pair *seq;
1179 : 32847155 : for (i = 0; edge_info->simple_equivalences.iterate (i, &seq); ++i)
1180 : : {
1181 : 11195502 : tree lhs = seq->first;
1182 : 11195502 : if (!lhs || TREE_CODE (lhs) != SSA_NAME)
1183 : 0 : continue;
1184 : :
1185 : : /* Record the simple NAME = VALUE equivalence. */
1186 : 11195502 : tree rhs = seq->second;
1187 : :
1188 : : /* If this is a SSA_NAME = SSA_NAME equivalence and one operand is
1189 : : cheaper to compute than the other, then set up the equivalence
1190 : : such that we replace the expensive one with the cheap one.
1191 : :
1192 : : If they are the same cost to compute, then do not record
1193 : : anything. */
1194 : 11195502 : if (TREE_CODE (lhs) == SSA_NAME && TREE_CODE (rhs) == SSA_NAME)
1195 : : {
1196 : 1454742 : gimple *rhs_def = SSA_NAME_DEF_STMT (rhs);
1197 : 1454742 : int rhs_cost = estimate_num_insns (rhs_def, &eni_size_weights);
1198 : :
1199 : 1454742 : gimple *lhs_def = SSA_NAME_DEF_STMT (lhs);
1200 : 1454742 : int lhs_cost = estimate_num_insns (lhs_def, &eni_size_weights);
1201 : :
1202 : 1454742 : if (rhs_cost > lhs_cost)
1203 : 153490 : record_equality (rhs, lhs, const_and_copies);
1204 : 1301252 : else if (rhs_cost < lhs_cost)
1205 : 359310 : record_equality (lhs, rhs, const_and_copies);
1206 : : }
1207 : : else
1208 : 9740760 : record_equality (lhs, rhs, const_and_copies);
1209 : :
1210 : :
1211 : : /* Any equivalence found for LHS may result in additional
1212 : : equivalences for other uses of LHS that we have already
1213 : : processed. */
1214 : 11195502 : back_propagate_equivalences (lhs, e, const_and_copies,
1215 : : blocks_on_stack);
1216 : : }
1217 : : }
1218 : 31037277 : }
1219 : :
1220 : : /* PHI nodes can create equivalences too.
1221 : :
1222 : : Ignoring any alternatives which are the same as the result, if
1223 : : all the alternatives are equal, then the PHI node creates an
1224 : : equivalence. */
1225 : :
1226 : : static void
1227 : 22111168 : record_equivalences_from_phis (basic_block bb)
1228 : : {
1229 : 22111168 : gphi_iterator gsi;
1230 : :
1231 : 30828092 : for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
1232 : : {
1233 : 8716924 : gphi *phi = gsi.phi ();
1234 : :
1235 : : /* We might eliminate the PHI, so advance GSI now. */
1236 : 8716924 : gsi_next (&gsi);
1237 : :
1238 : 8716924 : tree lhs = gimple_phi_result (phi);
1239 : 8716924 : tree rhs = NULL;
1240 : 8716924 : size_t i;
1241 : :
1242 : 15845095 : for (i = 0; i < gimple_phi_num_args (phi); i++)
1243 : : {
1244 : 14870125 : tree t = gimple_phi_arg_def (phi, i);
1245 : :
1246 : : /* Ignore alternatives which are the same as our LHS. Since
1247 : : LHS is a PHI_RESULT, it is known to be a SSA_NAME, so we
1248 : : can simply compare pointers. */
1249 : 14870125 : if (lhs == t)
1250 : 26476 : continue;
1251 : :
1252 : : /* If the associated edge is not marked as executable, then it
1253 : : can be ignored. */
1254 : 14843649 : if ((gimple_phi_arg_edge (phi, i)->flags & EDGE_EXECUTABLE) == 0)
1255 : 91551 : continue;
1256 : :
1257 : 14752098 : t = dom_valueize (t);
1258 : :
1259 : : /* If T is an SSA_NAME and its associated edge is a backedge,
1260 : : then quit as we cannot utilize this equivalence. */
1261 : 14752098 : if (TREE_CODE (t) == SSA_NAME
1262 : 14752098 : && (gimple_phi_arg_edge (phi, i)->flags & EDGE_DFS_BACK))
1263 : : break;
1264 : :
1265 : : /* If we have not processed an alternative yet, then set
1266 : : RHS to this alternative. */
1267 : 11991458 : if (rhs == NULL)
1268 : : rhs = t;
1269 : : /* If we have processed an alternative (stored in RHS), then
1270 : : see if it is equal to this one. If it isn't, then stop
1271 : : the search. */
1272 : 5522808 : else if (! operand_equal_for_phi_arg_p (rhs, t))
1273 : : break;
1274 : : }
1275 : :
1276 : : /* If we had no interesting alternatives, then all the RHS alternatives
1277 : : must have been the same as LHS. */
1278 : 8716924 : if (!rhs)
1279 : 2248274 : rhs = lhs;
1280 : :
1281 : : /* If we managed to iterate through each PHI alternative without
1282 : : breaking out of the loop, then we have a PHI which may create
1283 : : a useful equivalence. We do not need to record unwind data for
1284 : : this, since this is a true assignment and not an equivalence
1285 : : inferred from a comparison. All uses of this ssa name are dominated
1286 : : by this assignment, so unwinding just costs time and space. */
1287 : 8716924 : if (i == gimple_phi_num_args (phi))
1288 : : {
1289 : 974970 : if (may_propagate_copy (lhs, rhs))
1290 : 541741 : set_ssa_name_value (lhs, rhs);
1291 : 866458 : else if (virtual_operand_p (lhs))
1292 : : {
1293 : 432982 : gimple *use_stmt;
1294 : 432982 : imm_use_iterator iter;
1295 : 432982 : use_operand_p use_p;
1296 : : /* For virtual operands we have to propagate into all uses as
1297 : : otherwise we will create overlapping life-ranges. */
1298 : 1228119 : FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
1299 : 2429641 : FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1300 : 1250234 : SET_USE (use_p, rhs);
1301 : 432982 : if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
1302 : 68 : SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs) = 1;
1303 : 432982 : gimple_stmt_iterator tmp_gsi = gsi_for_stmt (phi);
1304 : 432982 : remove_phi_node (&tmp_gsi, true);
1305 : : }
1306 : : }
1307 : : }
1308 : 22111168 : }
1309 : :
1310 : : /* Return true if all uses of NAME are dominated by STMT or feed STMT
1311 : : via a chain of single immediate uses. */
1312 : :
1313 : : static bool
1314 : 273312 : all_uses_feed_or_dominated_by_stmt (tree name, gimple *stmt)
1315 : : {
1316 : 273312 : use_operand_p use_p, use2_p;
1317 : 273312 : imm_use_iterator iter;
1318 : 273312 : basic_block stmt_bb = gimple_bb (stmt);
1319 : :
1320 : 1078780 : FOR_EACH_IMM_USE_FAST (use_p, iter, name)
1321 : : {
1322 : 915714 : gimple *use_stmt = USE_STMT (use_p), *use_stmt2;
1323 : 1717976 : if (use_stmt == stmt
1324 : 805048 : || is_gimple_debug (use_stmt)
1325 : 1372219 : || (gimple_bb (use_stmt) != stmt_bb
1326 : 380581 : && dominated_by_p (CDI_DOMINATORS,
1327 : 380581 : gimple_bb (use_stmt), stmt_bb)))
1328 : 802262 : continue;
1329 : : while (use_stmt != stmt
1330 : 220494 : && is_gimple_assign (use_stmt)
1331 : 186391 : && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME
1332 : 406476 : && single_imm_use (gimple_assign_lhs (use_stmt),
1333 : : &use2_p, &use_stmt2))
1334 : 110248 : use_stmt = use_stmt2;
1335 : 113452 : if (use_stmt != stmt)
1336 : 110246 : return false;
1337 : : }
1338 : : return true;
1339 : : }
1340 : :
1341 : : /* Handle
1342 : : _4 = x_3 & 31;
1343 : : if (_4 != 0)
1344 : : goto <bb 6>;
1345 : : else
1346 : : goto <bb 7>;
1347 : : <bb 6>:
1348 : : __builtin_unreachable ();
1349 : : <bb 7>:
1350 : :
1351 : : If x_3 has no other immediate uses (checked by caller), var is the
1352 : : x_3 var, we can clear low 5 bits from the non-zero bitmask. */
1353 : :
1354 : : static void
1355 : 153263 : maybe_set_nonzero_bits (edge e, tree var)
1356 : : {
1357 : 153263 : basic_block cond_bb = e->src;
1358 : 306526 : gcond *cond = safe_dyn_cast <gcond *> (*gsi_last_bb (cond_bb));
1359 : 153263 : tree cst;
1360 : :
1361 : 153263 : if (cond == NULL
1362 : 153263 : || gimple_cond_code (cond) != ((e->flags & EDGE_TRUE_VALUE)
1363 : 153263 : ? EQ_EXPR : NE_EXPR)
1364 : 53838 : || TREE_CODE (gimple_cond_lhs (cond)) != SSA_NAME
1365 : 1518 : || !integer_zerop (gimple_cond_rhs (cond)))
1366 : 151842 : return;
1367 : :
1368 : 1421 : gimple *stmt = SSA_NAME_DEF_STMT (gimple_cond_lhs (cond));
1369 : 1421 : if (!is_gimple_assign (stmt)
1370 : 1396 : || gimple_assign_rhs_code (stmt) != BIT_AND_EXPR
1371 : 1438 : || TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST)
1372 : : return;
1373 : 1 : if (gimple_assign_rhs1 (stmt) != var)
1374 : : {
1375 : 1 : gimple *stmt2;
1376 : :
1377 : 1 : if (TREE_CODE (gimple_assign_rhs1 (stmt)) != SSA_NAME)
1378 : : return;
1379 : 1 : stmt2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
1380 : 1 : if (!gimple_assign_cast_p (stmt2)
1381 : 0 : || gimple_assign_rhs1 (stmt2) != var
1382 : 0 : || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt2))
1383 : 1 : || (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (stmt)))
1384 : 0 : != TYPE_PRECISION (TREE_TYPE (var))))
1385 : : return;
1386 : : }
1387 : 0 : cst = gimple_assign_rhs2 (stmt);
1388 : 0 : if (POINTER_TYPE_P (TREE_TYPE (var)))
1389 : : {
1390 : 0 : struct ptr_info_def *pi = SSA_NAME_PTR_INFO (var);
1391 : 0 : if (pi && pi->misalign)
1392 : 0 : return;
1393 : 0 : wide_int w = wi::bit_not (wi::to_wide (cst));
1394 : 0 : unsigned int bits = wi::ctz (w);
1395 : 0 : if (bits == 0 || bits >= HOST_BITS_PER_INT)
1396 : 0 : return;
1397 : 0 : unsigned int align = 1U << bits;
1398 : 0 : if (pi == NULL || pi->align < align)
1399 : 0 : set_ptr_info_alignment (get_ptr_info (var), align, 0);
1400 : 0 : }
1401 : : else
1402 : 0 : set_nonzero_bits (var, wi::bit_and_not (get_nonzero_bits (var),
1403 : 0 : wi::to_wide (cst)));
1404 : : }
1405 : :
1406 : : /* Set global ranges that can be determined from the C->M edge:
1407 : :
1408 : : <bb C>:
1409 : : ...
1410 : : if (something)
1411 : : goto <bb N>;
1412 : : else
1413 : : goto <bb M>;
1414 : : <bb N>:
1415 : : __builtin_unreachable ();
1416 : : <bb M>:
1417 : : */
1418 : :
1419 : : void
1420 : 22111168 : dom_opt_dom_walker::set_global_ranges_from_unreachable_edges (basic_block bb)
1421 : : {
1422 : 22111168 : edge pred_e = single_pred_edge_ignoring_loop_edges (bb, false);
1423 : 22111168 : if (!pred_e)
1424 : : return;
1425 : :
1426 : 16351211 : gimple *stmt = *gsi_last_bb (pred_e->src);
1427 : 16351211 : if (!stmt
1428 : 13708277 : || gimple_code (stmt) != GIMPLE_COND
1429 : 27466637 : || !assert_unreachable_fallthru_edge_p (pred_e))
1430 : 16166715 : return;
1431 : :
1432 : 184496 : tree name;
1433 : 457808 : FOR_EACH_GORI_EXPORT_NAME (m_ranger->gori_ssa (), pred_e->src, name)
1434 : 273312 : if (all_uses_feed_or_dominated_by_stmt (name, stmt)
1435 : : // The condition must post-dominate the definition point.
1436 : 436378 : && (SSA_NAME_IS_DEFAULT_DEF (name)
1437 : 162623 : || (gimple_bb (SSA_NAME_DEF_STMT (name))
1438 : 162623 : == pred_e->src)))
1439 : : {
1440 : 160085 : value_range r (TREE_TYPE (name));
1441 : :
1442 : 160085 : if (m_ranger->range_on_edge (r, pred_e, name)
1443 : 160085 : && !r.varying_p ()
1444 : 313370 : && !r.undefined_p ())
1445 : : {
1446 : 153263 : set_range_info (name, r);
1447 : 153263 : maybe_set_nonzero_bits (pred_e, name);
1448 : : }
1449 : 160085 : }
1450 : : }
1451 : :
1452 : : /* Record any equivalences created by the incoming edge to BB into
1453 : : CONST_AND_COPIES and AVAIL_EXPRS_STACK. If BB has more than one
1454 : : incoming edge, then no equivalence is created. */
1455 : :
1456 : : static void
1457 : 22111168 : record_equivalences_from_incoming_edge (basic_block bb,
1458 : : class const_and_copies *const_and_copies,
1459 : : class avail_exprs_stack *avail_exprs_stack,
1460 : : bitmap blocks_on_stack)
1461 : : {
1462 : 22111168 : edge e;
1463 : 22111168 : basic_block parent;
1464 : :
1465 : : /* If our parent block ended with a control statement, then we may be
1466 : : able to record some equivalences based on which outgoing edge from
1467 : : the parent was followed. */
1468 : 22111168 : parent = get_immediate_dominator (CDI_DOMINATORS, bb);
1469 : :
1470 : 22111168 : e = single_pred_edge_ignoring_loop_edges (bb, true);
1471 : :
1472 : : /* If we had a single incoming edge from our parent block, then enter
1473 : : any data associated with the edge into our tables. */
1474 : 22111168 : if (e && e->src == parent)
1475 : 16354805 : record_temporary_equivalences (e, const_and_copies, avail_exprs_stack,
1476 : : blocks_on_stack);
1477 : 22111168 : }
1478 : :
1479 : : /* Dump statistics for the hash table HTAB. */
1480 : :
1481 : : static void
1482 : 35 : htab_statistics (FILE *file, const hash_table<expr_elt_hasher> &htab)
1483 : : {
1484 : 66 : fprintf (file, "size " HOST_SIZE_T_PRINT_DEC ", " HOST_SIZE_T_PRINT_DEC
1485 : : " elements, %f collision/search ratio\n",
1486 : 35 : (fmt_size_t) htab.size (),
1487 : 35 : (fmt_size_t) htab.elements (),
1488 : : htab.collisions ());
1489 : 35 : }
1490 : :
1491 : : /* Dump SSA statistics on FILE. */
1492 : :
1493 : : static void
1494 : 35 : dump_dominator_optimization_stats (FILE *file,
1495 : : hash_table<expr_elt_hasher> *avail_exprs)
1496 : : {
1497 : 35 : fprintf (file, "Total number of statements: %6ld\n\n",
1498 : : opt_stats.num_stmts);
1499 : 35 : fprintf (file, "Exprs considered for dominator optimizations: %6ld\n",
1500 : : opt_stats.num_exprs_considered);
1501 : :
1502 : 35 : fprintf (file, "\nHash table statistics:\n");
1503 : :
1504 : 35 : fprintf (file, " avail_exprs: ");
1505 : 35 : htab_statistics (file, *avail_exprs);
1506 : 35 : }
1507 : :
1508 : :
1509 : : /* Similarly, but assume that X and Y are the two operands of an EQ_EXPR.
1510 : : This constrains the cases in which we may treat this as assignment. */
1511 : :
1512 : : static void
1513 : 12436786 : record_equality (tree x, tree y, class const_and_copies *const_and_copies)
1514 : : {
1515 : 12436786 : tree prev_x = NULL, prev_y = NULL;
1516 : :
1517 : 12436786 : if (tree_swap_operands_p (x, y))
1518 : 806460 : std::swap (x, y);
1519 : :
1520 : : /* Most of the time tree_swap_operands_p does what we want. But there
1521 : : are cases where we know one operand is better for copy propagation than
1522 : : the other. Given no other code cares about ordering of equality
1523 : : comparison operators for that purpose, we just handle the special cases
1524 : : here. */
1525 : 12436786 : if (TREE_CODE (x) == SSA_NAME && TREE_CODE (y) == SSA_NAME)
1526 : : {
1527 : : /* If one operand is a single use operand, then make it
1528 : : X. This will preserve its single use properly and if this
1529 : : conditional is eliminated, the computation of X can be
1530 : : eliminated as well. */
1531 : 959733 : if (has_single_use (y) && ! has_single_use (x))
1532 : : std::swap (x, y);
1533 : : }
1534 : 12436786 : if (TREE_CODE (x) == SSA_NAME)
1535 : 12181142 : prev_x = SSA_NAME_VALUE (x);
1536 : 12436786 : if (TREE_CODE (y) == SSA_NAME)
1537 : 1215377 : prev_y = SSA_NAME_VALUE (y);
1538 : :
1539 : : /* If one of the previous values is invariant, or invariant in more loops
1540 : : (by depth), then use that.
1541 : : Otherwise it doesn't matter which value we choose, just so
1542 : : long as we canonicalize on one value. */
1543 : 12436786 : if (is_gimple_min_invariant (y))
1544 : : ;
1545 : 1215377 : else if (is_gimple_min_invariant (x))
1546 : : prev_x = x, x = y, y = prev_x, prev_x = prev_y;
1547 : 959733 : else if (prev_x && is_gimple_min_invariant (prev_x))
1548 : : x = y, y = prev_x, prev_x = prev_y;
1549 : 865238 : else if (prev_y)
1550 : 12436786 : y = prev_y;
1551 : :
1552 : : /* After the swapping, we must have one SSA_NAME. */
1553 : 12436786 : if (TREE_CODE (x) != SSA_NAME)
1554 : : return;
1555 : :
1556 : : /* For IEEE, -0.0 == 0.0, so we don't necessarily know the sign of a
1557 : : variable compared against zero. If we're honoring signed zeros,
1558 : : then we cannot record this value unless we know that the value is
1559 : : nonzero. */
1560 : 12436786 : if (HONOR_SIGNED_ZEROS (x)
1561 : 12436786 : && (TREE_CODE (y) != REAL_CST
1562 : 168141 : || real_equal (&dconst0, &TREE_REAL_CST (y))))
1563 : 523 : return;
1564 : :
1565 : 12436263 : const_and_copies->record_const_or_copy (x, y, prev_x);
1566 : : }
1567 : :
1568 : : /* Returns true when STMT is a simple iv increment. It detects the
1569 : : following situation:
1570 : :
1571 : : i_1 = phi (..., i_k)
1572 : : [...]
1573 : : i_j = i_{j-1} for each j : 2 <= j <= k-1
1574 : : [...]
1575 : : i_k = i_{k-1} +/- ... */
1576 : :
1577 : : bool
1578 : 40054892 : simple_iv_increment_p (gimple *stmt)
1579 : : {
1580 : 40054892 : enum tree_code code;
1581 : 40054892 : tree lhs, preinc;
1582 : 40054892 : gimple *phi;
1583 : 40054892 : size_t i;
1584 : :
1585 : 40054892 : if (gimple_code (stmt) != GIMPLE_ASSIGN)
1586 : : return false;
1587 : :
1588 : 30628239 : lhs = gimple_assign_lhs (stmt);
1589 : 30628239 : if (TREE_CODE (lhs) != SSA_NAME)
1590 : : return false;
1591 : :
1592 : 30628239 : code = gimple_assign_rhs_code (stmt);
1593 : 30628239 : if (code != PLUS_EXPR
1594 : 30628239 : && code != MINUS_EXPR
1595 : 30628239 : && code != POINTER_PLUS_EXPR)
1596 : : return false;
1597 : :
1598 : 7166552 : preinc = gimple_assign_rhs1 (stmt);
1599 : 7166552 : if (TREE_CODE (preinc) != SSA_NAME)
1600 : : return false;
1601 : :
1602 : 6909143 : phi = SSA_NAME_DEF_STMT (preinc);
1603 : 6929994 : while (gimple_code (phi) != GIMPLE_PHI)
1604 : : {
1605 : : /* Follow trivial copies, but not the DEF used in a back edge,
1606 : : so that we don't prevent coalescing. */
1607 : 4689291 : if (!gimple_assign_ssa_name_copy_p (phi))
1608 : : return false;
1609 : 20851 : preinc = gimple_assign_rhs1 (phi);
1610 : 20851 : phi = SSA_NAME_DEF_STMT (preinc);
1611 : : }
1612 : :
1613 : 4384153 : for (i = 0; i < gimple_phi_num_args (phi); i++)
1614 : 3553614 : if (gimple_phi_arg_def (phi, i) == lhs)
1615 : : return true;
1616 : :
1617 : : return false;
1618 : : }
1619 : :
1620 : : /* Propagate know values from SSA_NAME_VALUE into the PHI nodes of the
1621 : : successors of BB. */
1622 : :
1623 : : static void
1624 : 22111168 : cprop_into_successor_phis (basic_block bb,
1625 : : class const_and_copies *const_and_copies)
1626 : : {
1627 : 22111168 : edge e;
1628 : 22111168 : edge_iterator ei;
1629 : :
1630 : 52473838 : FOR_EACH_EDGE (e, ei, bb->succs)
1631 : : {
1632 : 30362670 : int indx;
1633 : 30362670 : gphi_iterator gsi;
1634 : :
1635 : : /* If this is an abnormal edge, then we do not want to copy propagate
1636 : : into the PHI alternative associated with this edge. */
1637 : 30362670 : if (e->flags & EDGE_ABNORMAL)
1638 : 17973846 : continue;
1639 : :
1640 : 30349482 : gsi = gsi_start_phis (e->dest);
1641 : 30349482 : if (gsi_end_p (gsi))
1642 : 17960658 : continue;
1643 : :
1644 : : /* We may have an equivalence associated with this edge. While
1645 : : we cannot propagate it into non-dominated blocks, we can
1646 : : propagate them into PHIs in non-dominated blocks. */
1647 : :
1648 : : /* Push the unwind marker so we can reset the const and copies
1649 : : table back to its original state after processing this edge. */
1650 : 12388824 : const_and_copies->push_marker ();
1651 : :
1652 : : /* Extract and record any simple NAME = VALUE equivalences.
1653 : :
1654 : : Don't bother with [01] = COND equivalences, they're not useful
1655 : : here. */
1656 : 12388824 : class edge_info *edge_info = (class edge_info *) e->aux;
1657 : :
1658 : 12388824 : if (edge_info)
1659 : : {
1660 : : edge_info::equiv_pair *seq;
1661 : 7564623 : for (int i = 0; edge_info->simple_equivalences.iterate (i, &seq); ++i)
1662 : : {
1663 : 2878008 : tree lhs = seq->first;
1664 : 2878008 : tree rhs = seq->second;
1665 : :
1666 : 2878008 : if (lhs && TREE_CODE (lhs) == SSA_NAME)
1667 : 2878008 : const_and_copies->record_const_or_copy (lhs, rhs);
1668 : : }
1669 : :
1670 : : }
1671 : :
1672 : 12388824 : indx = e->dest_idx;
1673 : 33511402 : for ( ; !gsi_end_p (gsi); gsi_next (&gsi))
1674 : : {
1675 : 21122578 : tree new_val;
1676 : 21122578 : use_operand_p orig_p;
1677 : 21122578 : tree orig_val;
1678 : 21122578 : gphi *phi = gsi.phi ();
1679 : :
1680 : : /* The alternative may be associated with a constant, so verify
1681 : : it is an SSA_NAME before doing anything with it. */
1682 : 21122578 : orig_p = gimple_phi_arg_imm_use_ptr (phi, indx);
1683 : 21122578 : orig_val = get_use_from_ptr (orig_p);
1684 : 21122578 : if (TREE_CODE (orig_val) != SSA_NAME)
1685 : 2931734 : continue;
1686 : :
1687 : : /* If we have *ORIG_P in our constant/copy table, then replace
1688 : : ORIG_P with its value in our constant/copy table. */
1689 : 18190844 : new_val = SSA_NAME_VALUE (orig_val);
1690 : 18190844 : if (new_val
1691 : 18190844 : && new_val != orig_val
1692 : 18190844 : && may_propagate_copy (orig_val, new_val))
1693 : 1002160 : propagate_value (orig_p, new_val);
1694 : : }
1695 : :
1696 : 12388824 : const_and_copies->pop_to_marker ();
1697 : : }
1698 : 22111168 : }
1699 : :
1700 : : edge
1701 : 22111168 : dom_opt_dom_walker::before_dom_children (basic_block bb)
1702 : : {
1703 : 22111168 : gimple_stmt_iterator gsi;
1704 : :
1705 : 22111168 : if (dump_file && (dump_flags & TDF_DETAILS))
1706 : 721 : fprintf (dump_file, "\n\nOptimizing block #%d\n\n", bb->index);
1707 : :
1708 : : /* Push a marker on the stacks of local information so that we know how
1709 : : far to unwind when we finalize this block. */
1710 : 22111168 : m_avail_exprs_stack->push_marker ();
1711 : 22111168 : m_const_and_copies->push_marker ();
1712 : 22111168 : bitmap_set_bit (m_state->get_blocks_on_stack (), bb->index);
1713 : :
1714 : 22111168 : record_equivalences_from_incoming_edge (bb, m_const_and_copies,
1715 : : m_avail_exprs_stack,
1716 : 22111168 : m_state->get_blocks_on_stack ());
1717 : 22111168 : set_global_ranges_from_unreachable_edges (bb);
1718 : :
1719 : : /* PHI nodes can create equivalences too. */
1720 : 22111168 : record_equivalences_from_phis (bb);
1721 : :
1722 : : /* Create equivalences from redundant PHIs. PHIs are only truly
1723 : : redundant when they exist in the same block, so push another
1724 : : marker and unwind right afterwards. */
1725 : 22111168 : m_avail_exprs_stack->push_marker ();
1726 : 30395110 : for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1727 : 8283942 : eliminate_redundant_computations (&gsi, m_const_and_copies,
1728 : : m_avail_exprs_stack);
1729 : 22111168 : m_avail_exprs_stack->pop_to_marker ();
1730 : :
1731 : 22111168 : edge taken_edge = NULL;
1732 : : /* Initialize visited flag ahead of us, it has undefined state on
1733 : : pass entry. */
1734 : 192765640 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1735 : 148543304 : gimple_set_visited (gsi_stmt (gsi), false);
1736 : 319124109 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
1737 : : {
1738 : : /* Do not optimize a stmt twice, substitution might end up with
1739 : : _3 = _3 which is not valid. */
1740 : 297012941 : if (gimple_visited_p (gsi_stmt (gsi)))
1741 : : {
1742 : 148469498 : gsi_next (&gsi);
1743 : 148469498 : continue;
1744 : : }
1745 : :
1746 : 148543443 : bool removed_p = false;
1747 : 148543443 : taken_edge = this->optimize_stmt (bb, &gsi, &removed_p);
1748 : 148543443 : if (!removed_p)
1749 : 148469498 : gimple_set_visited (gsi_stmt (gsi), true);
1750 : :
1751 : : /* Go back and visit stmts inserted by folding after substituting
1752 : : into the stmt at gsi. */
1753 : 148543443 : if (gsi_end_p (gsi))
1754 : : {
1755 : 1891 : gcc_checking_assert (removed_p);
1756 : 1891 : gsi = gsi_last_bb (bb);
1757 : 3425 : while (!gsi_end_p (gsi) && !gimple_visited_p (gsi_stmt (gsi)))
1758 : 1891 : gsi_prev (&gsi);
1759 : : }
1760 : : else
1761 : : {
1762 : 148541691 : do
1763 : : {
1764 : 148541691 : gsi_prev (&gsi);
1765 : : }
1766 : 297083243 : while (!gsi_end_p (gsi) && !gimple_visited_p (gsi_stmt (gsi)));
1767 : : }
1768 : 148543443 : if (gsi_end_p (gsi))
1769 : 36206470 : gsi = gsi_start_bb (bb);
1770 : : else
1771 : 130440208 : gsi_next (&gsi);
1772 : : }
1773 : :
1774 : : /* Now prepare to process dominated blocks. */
1775 : 22111168 : record_edge_info (bb);
1776 : 22111168 : cprop_into_successor_phis (bb, m_const_and_copies);
1777 : 22111168 : if (taken_edge && !dbg_cnt (dom_unreachable_edges))
1778 : : return NULL;
1779 : :
1780 : : return taken_edge;
1781 : : }
1782 : :
1783 : : /* We have finished processing the dominator children of BB, perform
1784 : : any finalization actions in preparation for leaving this node in
1785 : : the dominator tree. */
1786 : :
1787 : : void
1788 : 22111168 : dom_opt_dom_walker::after_dom_children (basic_block bb)
1789 : : {
1790 : 22111168 : m_threader->thread_outgoing_edges (bb);
1791 : 22111168 : bitmap_clear_bit (m_state->get_blocks_on_stack (), bb->index);
1792 : 22111168 : m_avail_exprs_stack->pop_to_marker ();
1793 : 22111168 : m_const_and_copies->pop_to_marker ();
1794 : 22111168 : }
1795 : :
1796 : : /* Search for redundant computations in STMT. If any are found, then
1797 : : replace them with the variable holding the result of the computation.
1798 : :
1799 : : If safe, record this expression into AVAIL_EXPRS_STACK and
1800 : : CONST_AND_COPIES. */
1801 : :
1802 : : static void
1803 : 58996394 : eliminate_redundant_computations (gimple_stmt_iterator* gsi,
1804 : : class const_and_copies *const_and_copies,
1805 : : class avail_exprs_stack *avail_exprs_stack)
1806 : : {
1807 : 58996394 : tree expr_type;
1808 : 58996394 : tree cached_lhs;
1809 : 58996394 : tree def;
1810 : 58996394 : bool insert = true;
1811 : 58996394 : bool assigns_var_p = false;
1812 : :
1813 : 58996394 : gimple *stmt = gsi_stmt (*gsi);
1814 : :
1815 : 58996394 : if (gimple_code (stmt) == GIMPLE_PHI)
1816 : 8283942 : def = gimple_phi_result (stmt);
1817 : : else
1818 : 50712452 : def = gimple_get_lhs (stmt);
1819 : :
1820 : : /* Certain expressions on the RHS can be optimized away, but cannot
1821 : : themselves be entered into the hash tables. */
1822 : 58996394 : if (! def
1823 : 50801695 : || TREE_CODE (def) != SSA_NAME
1824 : 39094165 : || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def)
1825 : 30808998 : || gimple_vdef (stmt)
1826 : : /* Do not record equivalences for increments of ivs. This would create
1827 : : overlapping live ranges for a very questionable gain. */
1828 : 98080746 : || simple_iv_increment_p (stmt))
1829 : : insert = false;
1830 : :
1831 : : /* Check if the expression has been computed before. */
1832 : 58996394 : cached_lhs = avail_exprs_stack->lookup_avail_expr (stmt, insert, true);
1833 : :
1834 : 58996394 : opt_stats.num_exprs_considered++;
1835 : :
1836 : : /* Get the type of the expression we are trying to optimize. */
1837 : 58996394 : if (is_gimple_assign (stmt))
1838 : : {
1839 : 41348822 : expr_type = TREE_TYPE (gimple_assign_lhs (stmt));
1840 : 41348822 : assigns_var_p = true;
1841 : : }
1842 : 17647572 : else if (gimple_code (stmt) == GIMPLE_COND)
1843 : 8162333 : expr_type = boolean_type_node;
1844 : 9485239 : else if (is_gimple_call (stmt))
1845 : : {
1846 : 1168931 : gcc_assert (gimple_call_lhs (stmt));
1847 : 1168931 : expr_type = TREE_TYPE (gimple_call_lhs (stmt));
1848 : 1168931 : assigns_var_p = true;
1849 : : }
1850 : 8316308 : else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt))
1851 : 32366 : expr_type = TREE_TYPE (gimple_switch_index (swtch_stmt));
1852 : 8283942 : else if (gimple_code (stmt) == GIMPLE_PHI)
1853 : : /* We can't propagate into a phi, so the logic below doesn't apply.
1854 : : Instead record an equivalence between the cached LHS and the
1855 : : PHI result of this statement, provided they are in the same block.
1856 : : This should be sufficient to kill the redundant phi. */
1857 : : {
1858 : 8283942 : if (def && cached_lhs)
1859 : 18347 : const_and_copies->record_const_or_copy (def, cached_lhs);
1860 : 8283942 : return;
1861 : : }
1862 : : else
1863 : 0 : gcc_unreachable ();
1864 : :
1865 : 50712452 : if (!cached_lhs)
1866 : : return;
1867 : :
1868 : : /* It is safe to ignore types here since we have already done
1869 : : type checking in the hashing and equality routines. In fact
1870 : : type checking here merely gets in the way of constant
1871 : : propagation. Also, make sure that it is safe to propagate
1872 : : CACHED_LHS into the expression in STMT. */
1873 : 326197 : if ((TREE_CODE (cached_lhs) != SSA_NAME
1874 : 36392 : && (assigns_var_p
1875 : 4737 : || useless_type_conversion_p (expr_type, TREE_TYPE (cached_lhs))))
1876 : 326197 : || may_propagate_copy_into_stmt (stmt, cached_lhs))
1877 : : {
1878 : 326169 : gcc_checking_assert (TREE_CODE (cached_lhs) == SSA_NAME
1879 : : || is_gimple_min_invariant (cached_lhs));
1880 : :
1881 : 326169 : if (dump_file && (dump_flags & TDF_DETAILS))
1882 : : {
1883 : 16 : fprintf (dump_file, " Replaced redundant expr '");
1884 : 16 : print_gimple_expr (dump_file, stmt, 0, dump_flags);
1885 : 16 : fprintf (dump_file, "' with '");
1886 : 16 : print_generic_expr (dump_file, cached_lhs, dump_flags);
1887 : 16 : fprintf (dump_file, "'\n");
1888 : : }
1889 : :
1890 : 326169 : opt_stats.num_re++;
1891 : :
1892 : 326169 : if (assigns_var_p
1893 : 326169 : && !useless_type_conversion_p (expr_type, TREE_TYPE (cached_lhs)))
1894 : 0 : cached_lhs = fold_convert (expr_type, cached_lhs);
1895 : :
1896 : 326169 : propagate_tree_value_into_stmt (gsi, cached_lhs);
1897 : :
1898 : : /* Since it is always necessary to mark the result as modified,
1899 : : perhaps we should move this into propagate_tree_value_into_stmt
1900 : : itself. */
1901 : 326169 : gimple_set_modified (gsi_stmt (*gsi), true);
1902 : : }
1903 : : }
1904 : :
1905 : : /* STMT, a GIMPLE_ASSIGN, may create certain equivalences, in either
1906 : : the available expressions table or the const_and_copies table.
1907 : : Detect and record those equivalences into AVAIL_EXPRS_STACK.
1908 : :
1909 : : We handle only very simple copy equivalences here. The heavy
1910 : : lifing is done by eliminate_redundant_computations. */
1911 : :
1912 : : static void
1913 : 44928606 : record_equivalences_from_stmt (gimple *stmt, int may_optimize_p,
1914 : : class avail_exprs_stack *avail_exprs_stack)
1915 : : {
1916 : 44928606 : tree lhs;
1917 : 44928606 : enum tree_code lhs_code;
1918 : :
1919 : 44928606 : gcc_assert (is_gimple_assign (stmt));
1920 : :
1921 : 44928606 : lhs = gimple_assign_lhs (stmt);
1922 : 44928606 : lhs_code = TREE_CODE (lhs);
1923 : :
1924 : 44928606 : if (lhs_code == SSA_NAME
1925 : 44928606 : && gimple_assign_single_p (stmt))
1926 : : {
1927 : 14775097 : tree rhs = gimple_assign_rhs1 (stmt);
1928 : :
1929 : : /* If the RHS of the assignment is a constant or another variable that
1930 : : may be propagated, register it in the CONST_AND_COPIES table. We
1931 : : do not need to record unwind data for this, since this is a true
1932 : : assignment and not an equivalence inferred from a comparison. All
1933 : : uses of this ssa name are dominated by this assignment, so unwinding
1934 : : just costs time and space. */
1935 : 14775097 : if (may_optimize_p
1936 : 14775097 : && (TREE_CODE (rhs) == SSA_NAME
1937 : 12880190 : || is_gimple_min_invariant (rhs)))
1938 : : {
1939 : 1804950 : rhs = dom_valueize (rhs);
1940 : :
1941 : 1804950 : if (dump_file && (dump_flags & TDF_DETAILS))
1942 : : {
1943 : 74 : fprintf (dump_file, "==== ASGN ");
1944 : 74 : print_generic_expr (dump_file, lhs);
1945 : 74 : fprintf (dump_file, " = ");
1946 : 74 : print_generic_expr (dump_file, rhs);
1947 : 74 : fprintf (dump_file, "\n");
1948 : : }
1949 : :
1950 : 1804950 : set_ssa_name_value (lhs, rhs);
1951 : : }
1952 : : }
1953 : :
1954 : : /* Make sure we can propagate &x + CST. */
1955 : 44928606 : if (lhs_code == SSA_NAME
1956 : 30234723 : && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
1957 : 1472464 : && TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR
1958 : 45113716 : && TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST)
1959 : : {
1960 : 4131 : tree op0 = gimple_assign_rhs1 (stmt);
1961 : 4131 : tree op1 = gimple_assign_rhs2 (stmt);
1962 : 4131 : tree new_rhs
1963 : 8262 : = build1 (ADDR_EXPR, TREE_TYPE (op0),
1964 : 4131 : fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (op0)),
1965 : : unshare_expr (op0), fold_convert (ptr_type_node,
1966 : : op1)));
1967 : 4131 : if (dump_file && (dump_flags & TDF_DETAILS))
1968 : : {
1969 : 0 : fprintf (dump_file, "==== ASGN ");
1970 : 0 : print_generic_expr (dump_file, lhs);
1971 : 0 : fprintf (dump_file, " = ");
1972 : 0 : print_generic_expr (dump_file, new_rhs);
1973 : 0 : fprintf (dump_file, "\n");
1974 : : }
1975 : :
1976 : 4131 : set_ssa_name_value (lhs, new_rhs);
1977 : : }
1978 : :
1979 : : /* A memory store, even an aliased store, creates a useful
1980 : : equivalence. By exchanging the LHS and RHS, creating suitable
1981 : : vops and recording the result in the available expression table,
1982 : : we may be able to expose more redundant loads. */
1983 : 86204076 : if (!gimple_has_volatile_ops (stmt)
1984 : 67429377 : && gimple_references_memory_p (stmt)
1985 : 22500771 : && gimple_assign_single_p (stmt)
1986 : 22500771 : && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
1987 : 17589116 : || is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
1988 : 55587255 : && !is_gimple_reg (lhs))
1989 : : {
1990 : 10514907 : tree rhs = gimple_assign_rhs1 (stmt);
1991 : 10514907 : gassign *new_stmt;
1992 : :
1993 : : /* Build a new statement with the RHS and LHS exchanged. */
1994 : 10514907 : if (TREE_CODE (rhs) == SSA_NAME)
1995 : : {
1996 : : /* NOTE tuples. The call to gimple_build_assign below replaced
1997 : : a call to build_gimple_modify_stmt, which did not set the
1998 : : SSA_NAME_DEF_STMT on the LHS of the assignment. Doing so
1999 : : may cause an SSA validation failure, as the LHS may be a
2000 : : default-initialized name and should have no definition. I'm
2001 : : a bit dubious of this, as the artificial statement that we
2002 : : generate here may in fact be ill-formed, but it is simply
2003 : : used as an internal device in this pass, and never becomes
2004 : : part of the CFG. */
2005 : 4794887 : gimple *defstmt = SSA_NAME_DEF_STMT (rhs);
2006 : 4794887 : new_stmt = gimple_build_assign (rhs, lhs);
2007 : 4794887 : SSA_NAME_DEF_STMT (rhs) = defstmt;
2008 : : }
2009 : : else
2010 : 5720020 : new_stmt = gimple_build_assign (rhs, lhs);
2011 : :
2012 : 21029814 : gimple_set_vuse (new_stmt, gimple_vdef (stmt));
2013 : :
2014 : : /* Finally enter the statement into the available expression
2015 : : table. */
2016 : 10514907 : avail_exprs_stack->lookup_avail_expr (new_stmt, true, true);
2017 : : }
2018 : 44928606 : }
2019 : :
2020 : : /* Replace *OP_P in STMT with any known equivalent value for *OP_P from
2021 : : CONST_AND_COPIES. */
2022 : :
2023 : : static void
2024 : 72357984 : cprop_operand (gimple *stmt, use_operand_p op_p, range_query *query)
2025 : : {
2026 : 72357984 : tree val;
2027 : 72357984 : tree op = USE_FROM_PTR (op_p);
2028 : :
2029 : : /* If the operand has a known constant value or it is known to be a
2030 : : copy of some other variable, use the value or copy stored in
2031 : : CONST_AND_COPIES. */
2032 : 72357984 : val = SSA_NAME_VALUE (op);
2033 : 47720600 : if (!val)
2034 : : {
2035 : 68822740 : value_range r (TREE_TYPE (op));
2036 : 68822740 : tree single;
2037 : 135510671 : if (query->range_of_expr (r, op, stmt) && r.singleton_p (&single))
2038 : 19422 : val = single;
2039 : 68822740 : }
2040 : :
2041 : 72357984 : if (val && val != op)
2042 : : {
2043 : : /* Do not replace hard register operands in asm statements. */
2044 : 3552823 : if (gimple_code (stmt) == GIMPLE_ASM
2045 : 3552823 : && !may_propagate_copy_into_asm (op))
2046 : : return;
2047 : :
2048 : : /* Certain operands are not allowed to be copy propagated due
2049 : : to their interaction with exception handling and some GCC
2050 : : extensions. */
2051 : 3552823 : if (!may_propagate_copy (op, val))
2052 : : return;
2053 : :
2054 : : /* Do not propagate copies into BIVs.
2055 : : See PR23821 and PR62217 for how this can disturb IV and
2056 : : number of iteration analysis. */
2057 : 3551335 : if (TREE_CODE (val) != INTEGER_CST)
2058 : : {
2059 : 2918134 : gimple *def = SSA_NAME_DEF_STMT (op);
2060 : 2918134 : if (gimple_code (def) == GIMPLE_PHI
2061 : 2918134 : && gimple_bb (def)->loop_father->header == gimple_bb (def))
2062 : : return;
2063 : : }
2064 : :
2065 : : /* Dump details. */
2066 : 3534255 : if (dump_file && (dump_flags & TDF_DETAILS))
2067 : : {
2068 : 76 : fprintf (dump_file, " Replaced '");
2069 : 76 : print_generic_expr (dump_file, op, dump_flags);
2070 : 76 : fprintf (dump_file, "' with %s '",
2071 : 76 : (TREE_CODE (val) != SSA_NAME ? "constant" : "variable"));
2072 : 76 : print_generic_expr (dump_file, val, dump_flags);
2073 : 76 : fprintf (dump_file, "'\n");
2074 : : }
2075 : :
2076 : 3534255 : if (TREE_CODE (val) != SSA_NAME)
2077 : 803494 : opt_stats.num_const_prop++;
2078 : : else
2079 : 2730761 : opt_stats.num_copy_prop++;
2080 : :
2081 : 3534255 : propagate_value (op_p, val);
2082 : :
2083 : : /* And note that we modified this statement. This is now
2084 : : safe, even if we changed virtual operands since we will
2085 : : rescan the statement and rewrite its operands again. */
2086 : 3534255 : gimple_set_modified (stmt, true);
2087 : : }
2088 : : }
2089 : :
2090 : : /* CONST_AND_COPIES is a table which maps an SSA_NAME to the current
2091 : : known value for that SSA_NAME (or NULL if no value is known).
2092 : :
2093 : : Propagate values from CONST_AND_COPIES into the uses, vuses and
2094 : : vdef_ops of STMT. */
2095 : :
2096 : : static void
2097 : 148543443 : cprop_into_stmt (gimple *stmt, range_query *query)
2098 : : {
2099 : 148543443 : use_operand_p op_p;
2100 : 148543443 : ssa_op_iter iter;
2101 : 148543443 : tree last_copy_propagated_op = NULL;
2102 : :
2103 : 220902033 : FOR_EACH_SSA_USE_OPERAND (op_p, stmt, iter, SSA_OP_USE)
2104 : : {
2105 : 72358590 : tree old_op = USE_FROM_PTR (op_p);
2106 : :
2107 : : /* If we have A = B and B = A in the copy propagation tables
2108 : : (due to an equality comparison), avoid substituting B for A
2109 : : then A for B in the trivially discovered cases. This allows
2110 : : optimization of statements were A and B appear as input
2111 : : operands. */
2112 : 72358590 : if (old_op != last_copy_propagated_op)
2113 : : {
2114 : 72357984 : cprop_operand (stmt, op_p, query);
2115 : :
2116 : 72357984 : tree new_op = USE_FROM_PTR (op_p);
2117 : 72357984 : if (new_op != old_op && TREE_CODE (new_op) == SSA_NAME)
2118 : 72358590 : last_copy_propagated_op = new_op;
2119 : : }
2120 : : }
2121 : 148543443 : }
2122 : :
2123 : : /* If STMT contains a relational test, try to convert it into an
2124 : : equality test if there is only a single value which can ever
2125 : : make the test true.
2126 : :
2127 : : For example, if the expression hash table contains:
2128 : :
2129 : : TRUE = (i <= 1)
2130 : :
2131 : : And we have a test within statement of i >= 1, then we can safely
2132 : : rewrite the test as i == 1 since there only a single value where
2133 : : the test is true.
2134 : :
2135 : : This is similar to code in VRP. */
2136 : :
2137 : : void
2138 : 50638507 : dom_opt_dom_walker::test_for_singularity (gimple *stmt,
2139 : : avail_exprs_stack *avail_exprs_stack)
2140 : : {
2141 : : /* We want to support gimple conditionals as well as assignments
2142 : : where the RHS contains a conditional. */
2143 : 50638507 : if (is_gimple_assign (stmt) || gimple_code (stmt) == GIMPLE_COND)
2144 : : {
2145 : 49437803 : enum tree_code code = ERROR_MARK;
2146 : 49437803 : tree lhs, rhs;
2147 : :
2148 : : /* Extract the condition of interest from both forms we support. */
2149 : 49437803 : if (is_gimple_assign (stmt))
2150 : : {
2151 : 41275470 : code = gimple_assign_rhs_code (stmt);
2152 : 41275470 : lhs = gimple_assign_rhs1 (stmt);
2153 : 41275470 : rhs = gimple_assign_rhs2 (stmt);
2154 : : }
2155 : 8162333 : else if (gimple_code (stmt) == GIMPLE_COND)
2156 : : {
2157 : 8162333 : code = gimple_cond_code (as_a <gcond *> (stmt));
2158 : 8162333 : lhs = gimple_cond_lhs (as_a <gcond *> (stmt));
2159 : 8162333 : rhs = gimple_cond_rhs (as_a <gcond *> (stmt));
2160 : : }
2161 : :
2162 : : /* We're looking for a relational test using LE/GE. Also note we can
2163 : : canonicalize LT/GT tests against constants into LE/GT tests. */
2164 : 49437803 : if (code == LE_EXPR || code == GE_EXPR
2165 : 48822013 : || ((code == LT_EXPR || code == GT_EXPR)
2166 : 1527183 : && TREE_CODE (rhs) == INTEGER_CST))
2167 : : {
2168 : : /* For LT_EXPR and GT_EXPR, canonicalize to LE_EXPR and GE_EXPR. */
2169 : 804431 : if (code == LT_EXPR)
2170 : 101616 : rhs = fold_build2 (MINUS_EXPR, TREE_TYPE (rhs),
2171 : : rhs, build_int_cst (TREE_TYPE (rhs), 1));
2172 : :
2173 : 1420221 : if (code == GT_EXPR)
2174 : 702815 : rhs = fold_build2 (PLUS_EXPR, TREE_TYPE (rhs),
2175 : : rhs, build_int_cst (TREE_TYPE (rhs), 1));
2176 : :
2177 : : /* Determine the code we want to check for in the hash table. */
2178 : 1420221 : enum tree_code test_code;
2179 : 1420221 : if (code == GE_EXPR || code == GT_EXPR)
2180 : : test_code = LE_EXPR;
2181 : : else
2182 : 476014 : test_code = GE_EXPR;
2183 : :
2184 : : /* Update the dummy statement so we can query the hash tables. */
2185 : 1420221 : gimple_cond_set_code (m_dummy_cond, test_code);
2186 : 1420221 : gimple_cond_set_lhs (m_dummy_cond, lhs);
2187 : 1420221 : gimple_cond_set_rhs (m_dummy_cond, rhs);
2188 : 1420221 : tree cached_lhs
2189 : 1420221 : = avail_exprs_stack->lookup_avail_expr (m_dummy_cond,
2190 : : false, false);
2191 : :
2192 : : /* If the lookup returned 1 (true), then the expression we
2193 : : queried was in the hash table. As a result there is only
2194 : : one value that makes the original conditional true. Update
2195 : : STMT accordingly. */
2196 : 1420221 : if (cached_lhs && integer_onep (cached_lhs))
2197 : : {
2198 : 1426 : if (is_gimple_assign (stmt))
2199 : : {
2200 : 100 : gimple_assign_set_rhs_code (stmt, EQ_EXPR);
2201 : 100 : gimple_assign_set_rhs2 (stmt, rhs);
2202 : 100 : gimple_set_modified (stmt, true);
2203 : : }
2204 : : else
2205 : : {
2206 : 1326 : gimple_set_modified (stmt, true);
2207 : 1326 : gimple_cond_set_code (as_a <gcond *> (stmt), EQ_EXPR);
2208 : 1326 : gimple_cond_set_rhs (as_a <gcond *> (stmt), rhs);
2209 : 1326 : gimple_set_modified (stmt, true);
2210 : : }
2211 : : }
2212 : : }
2213 : : }
2214 : 50638507 : }
2215 : :
2216 : : /* If STMT is a comparison of two uniform vectors reduce it to a comparison
2217 : : of scalar objects, otherwise leave STMT unchanged. */
2218 : :
2219 : : static void
2220 : 148543443 : reduce_vector_comparison_to_scalar_comparison (gimple *stmt)
2221 : : {
2222 : 148543443 : if (gimple_code (stmt) == GIMPLE_COND)
2223 : : {
2224 : 8258711 : tree lhs = gimple_cond_lhs (stmt);
2225 : 8258711 : tree rhs = gimple_cond_rhs (stmt);
2226 : :
2227 : : /* We may have a vector comparison where both arms are uniform
2228 : : vectors. If so, we can simplify the vector comparison down
2229 : : to a scalar comparison. */
2230 : 8258711 : if (VECTOR_TYPE_P (TREE_TYPE (lhs))
2231 : 8258711 : && VECTOR_TYPE_P (TREE_TYPE (rhs)))
2232 : : {
2233 : : /* If either operand is an SSA_NAME, then look back to its
2234 : : defining statement to try and get at a suitable source. */
2235 : 2000 : if (TREE_CODE (rhs) == SSA_NAME)
2236 : : {
2237 : 0 : gimple *def_stmt = SSA_NAME_DEF_STMT (rhs);
2238 : 0 : if (gimple_assign_single_p (def_stmt))
2239 : 0 : rhs = gimple_assign_rhs1 (def_stmt);
2240 : : }
2241 : :
2242 : 2000 : if (TREE_CODE (lhs) == SSA_NAME)
2243 : : {
2244 : 2000 : gimple *def_stmt = SSA_NAME_DEF_STMT (lhs);
2245 : 2000 : if (gimple_assign_single_p (def_stmt))
2246 : 3 : lhs = gimple_assign_rhs1 (def_stmt);
2247 : : }
2248 : :
2249 : : /* Now see if they are both uniform vectors and if so replace
2250 : : the vector comparison with a scalar comparison. */
2251 : 2000 : tree rhs_elem = rhs ? uniform_vector_p (rhs) : NULL_TREE;
2252 : 2000 : tree lhs_elem = lhs ? uniform_vector_p (lhs) : NULL_TREE;
2253 : 2000 : if (rhs_elem && lhs_elem)
2254 : : {
2255 : 1 : if (dump_file && dump_flags & TDF_DETAILS)
2256 : : {
2257 : 0 : fprintf (dump_file, "Reducing vector comparison: ");
2258 : 0 : print_gimple_stmt (dump_file, stmt, 0);
2259 : : }
2260 : :
2261 : 1 : gimple_cond_set_rhs (as_a <gcond *>(stmt), rhs_elem);
2262 : 1 : gimple_cond_set_lhs (as_a <gcond *>(stmt), lhs_elem);
2263 : 1 : gimple_set_modified (stmt, true);
2264 : :
2265 : 1 : if (dump_file && dump_flags & TDF_DETAILS)
2266 : : {
2267 : 0 : fprintf (dump_file, "To scalar equivalent: ");
2268 : 0 : print_gimple_stmt (dump_file, stmt, 0);
2269 : 0 : fprintf (dump_file, "\n");
2270 : : }
2271 : : }
2272 : : }
2273 : : }
2274 : 148543443 : }
2275 : :
2276 : : /* If possible, rewrite the conditional as TRUE or FALSE, and return
2277 : : the taken edge. Otherwise, return NULL. */
2278 : :
2279 : : edge
2280 : 8060993 : dom_opt_dom_walker::fold_cond (gcond *cond)
2281 : : {
2282 : 8060993 : simplify_using_ranges simplify (m_ranger);
2283 : 8060993 : if (simplify.fold_cond (cond))
2284 : : {
2285 : 96378 : basic_block bb = gimple_bb (cond);
2286 : 96378 : if (gimple_cond_true_p (cond))
2287 : 18656 : return find_taken_edge (bb, boolean_true_node);
2288 : 77722 : if (gimple_cond_false_p (cond))
2289 : 77722 : return find_taken_edge (bb, boolean_false_node);
2290 : : }
2291 : : return NULL;
2292 : 8060993 : }
2293 : :
2294 : : /* Optimize the statement in block BB pointed to by iterator SI.
2295 : :
2296 : : We try to perform some simplistic global redundancy elimination and
2297 : : constant propagation:
2298 : :
2299 : : 1- To detect global redundancy, we keep track of expressions that have
2300 : : been computed in this block and its dominators. If we find that the
2301 : : same expression is computed more than once, we eliminate repeated
2302 : : computations by using the target of the first one.
2303 : :
2304 : : 2- Constant values and copy assignments. This is used to do very
2305 : : simplistic constant and copy propagation. When a constant or copy
2306 : : assignment is found, we map the value on the RHS of the assignment to
2307 : : the variable in the LHS in the CONST_AND_COPIES table.
2308 : :
2309 : : 3- Very simple redundant store elimination is performed.
2310 : :
2311 : : 4- We can simplify a condition to a constant or from a relational
2312 : : condition to an equality condition. */
2313 : :
2314 : : edge
2315 : 148543443 : dom_opt_dom_walker::optimize_stmt (basic_block bb, gimple_stmt_iterator *si,
2316 : : bool *removed_p)
2317 : : {
2318 : 148543443 : gimple *stmt, *old_stmt;
2319 : 148543443 : bool may_optimize_p;
2320 : 148543443 : bool modified_p = false;
2321 : 148543443 : bool was_noreturn;
2322 : 148543443 : edge retval = NULL;
2323 : :
2324 : 148543443 : old_stmt = stmt = gsi_stmt (*si);
2325 : 148543443 : was_noreturn = is_gimple_call (stmt) && gimple_call_noreturn_p (stmt);
2326 : :
2327 : 148543443 : if (dump_file && (dump_flags & TDF_DETAILS))
2328 : : {
2329 : 1579 : fprintf (dump_file, "Optimizing statement ");
2330 : 1579 : print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
2331 : : }
2332 : :
2333 : : /* STMT may be a comparison of uniform vectors that we can simplify
2334 : : down to a comparison of scalars. Do that transformation first
2335 : : so that all the scalar optimizations from here onward apply. */
2336 : 148543443 : reduce_vector_comparison_to_scalar_comparison (stmt);
2337 : :
2338 : 148543443 : update_stmt_if_modified (stmt);
2339 : 148543443 : opt_stats.num_stmts++;
2340 : :
2341 : : /* Const/copy propagate into USES, VUSES and the RHS of VDEFs. */
2342 : 148543443 : cprop_into_stmt (stmt, m_ranger);
2343 : :
2344 : : /* If the statement has been modified with constant replacements,
2345 : : fold its RHS before checking for redundant computations. */
2346 : 296790616 : if (gimple_modified_p (stmt))
2347 : : {
2348 : 3402725 : tree rhs = NULL;
2349 : :
2350 : : /* Try to fold the statement making sure that STMT is kept
2351 : : up to date. */
2352 : 3402725 : if (fold_stmt (si))
2353 : : {
2354 : 345121 : stmt = gsi_stmt (*si);
2355 : 345121 : gimple_set_modified (stmt, true);
2356 : :
2357 : 345121 : if (dump_file && (dump_flags & TDF_DETAILS))
2358 : : {
2359 : 12 : fprintf (dump_file, " Folded to: ");
2360 : 12 : print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
2361 : : }
2362 : : }
2363 : :
2364 : : /* We only need to consider cases that can yield a gimple operand. */
2365 : 3402725 : if (gimple_assign_single_p (stmt))
2366 : 1311642 : rhs = gimple_assign_rhs1 (stmt);
2367 : 2091083 : else if (gimple_code (stmt) == GIMPLE_GOTO)
2368 : 1 : rhs = gimple_goto_dest (stmt);
2369 : 150634525 : else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt))
2370 : : /* This should never be an ADDR_EXPR. */
2371 : 2030 : rhs = gimple_switch_index (swtch_stmt);
2372 : :
2373 : 1313673 : if (rhs && TREE_CODE (rhs) == ADDR_EXPR)
2374 : 87196 : recompute_tree_invariant_for_addr_expr (rhs);
2375 : :
2376 : : /* Indicate that maybe_clean_or_replace_eh_stmt needs to be called,
2377 : : even if fold_stmt updated the stmt already and thus cleared
2378 : : gimple_modified_p flag on it. */
2379 : : modified_p = true;
2380 : : }
2381 : :
2382 : : /* Check for redundant computations. Do this optimization only
2383 : : for assignments that have no volatile ops and conditionals. */
2384 : 148543443 : may_optimize_p = (!gimple_has_side_effects (stmt)
2385 : 148543443 : && (is_gimple_assign (stmt)
2386 : 94501292 : || (is_gimple_call (stmt)
2387 : 1169207 : && gimple_call_lhs (stmt) != NULL_TREE)
2388 : 93332311 : || gimple_code (stmt) == GIMPLE_COND
2389 : 85073600 : || gimple_code (stmt) == GIMPLE_SWITCH));
2390 : :
2391 : 50808830 : if (may_optimize_p)
2392 : : {
2393 : 50808830 : if (gimple_code (stmt) == GIMPLE_CALL)
2394 : : {
2395 : : /* Resolve __builtin_constant_p. If it hasn't been
2396 : : folded to integer_one_node by now, it's fairly
2397 : : certain that the value simply isn't constant. */
2398 : 1168981 : tree callee = gimple_call_fndecl (stmt);
2399 : 1168981 : if (callee
2400 : 1168981 : && fndecl_built_in_p (callee, BUILT_IN_CONSTANT_P))
2401 : : {
2402 : 50 : propagate_tree_value_into_stmt (si, integer_zero_node);
2403 : 50 : stmt = gsi_stmt (*si);
2404 : : }
2405 : : }
2406 : :
2407 : 50808830 : if (gimple_code (stmt) == GIMPLE_COND)
2408 : : {
2409 : 8258711 : tree lhs = gimple_cond_lhs (stmt);
2410 : 8258711 : tree rhs = gimple_cond_rhs (stmt);
2411 : :
2412 : : /* If the LHS has a range [0..1] and the RHS has a range ~[0..1],
2413 : : then this conditional is computable at compile time. We can just
2414 : : shove either 0 or 1 into the LHS, mark the statement as modified
2415 : : and all the right things will just happen below.
2416 : :
2417 : : Note this would apply to any case where LHS has a range
2418 : : narrower than its type implies and RHS is outside that
2419 : : narrower range. Future work. */
2420 : 8258711 : if (TREE_CODE (lhs) == SSA_NAME
2421 : 8061020 : && ssa_name_has_boolean_range (lhs)
2422 : 962817 : && TREE_CODE (rhs) == INTEGER_CST
2423 : 9191914 : && ! (integer_zerop (rhs) || integer_onep (rhs)))
2424 : : {
2425 : 27 : gimple_cond_set_lhs (as_a <gcond *> (stmt),
2426 : 27 : fold_convert (TREE_TYPE (lhs),
2427 : : integer_zero_node));
2428 : 27 : gimple_set_modified (stmt, true);
2429 : : }
2430 : 8258684 : else if (TREE_CODE (lhs) == SSA_NAME)
2431 : : {
2432 : : /* Exploiting EVRP data is not yet fully integrated into DOM
2433 : : but we need to do something for this case to avoid regressing
2434 : : udr4.f90 and new1.C which have unexecutable blocks with
2435 : : undefined behavior that get diagnosed if they're left in the
2436 : : IL because we've attached range information to new
2437 : : SSA_NAMES. */
2438 : 8060993 : update_stmt_if_modified (stmt);
2439 : 8060993 : edge taken_edge = fold_cond (as_a <gcond *> (stmt));
2440 : 8060993 : if (taken_edge)
2441 : : {
2442 : 96378 : gimple_set_modified (stmt, true);
2443 : 96378 : update_stmt (stmt);
2444 : 96378 : cfg_altered = true;
2445 : 96378 : return taken_edge;
2446 : : }
2447 : : }
2448 : : }
2449 : :
2450 : 50712452 : update_stmt_if_modified (stmt);
2451 : 50712452 : eliminate_redundant_computations (si, m_const_and_copies,
2452 : : m_avail_exprs_stack);
2453 : 50712452 : stmt = gsi_stmt (*si);
2454 : :
2455 : : /* Perform simple redundant store elimination. */
2456 : 50712452 : if (gimple_assign_single_p (stmt)
2457 : 50712452 : && TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
2458 : : {
2459 : 11689946 : tree lhs = gimple_assign_lhs (stmt);
2460 : 11689946 : tree rhs = gimple_assign_rhs1 (stmt);
2461 : 11689946 : tree cached_lhs;
2462 : 11689946 : gassign *new_stmt;
2463 : 11689946 : rhs = dom_valueize (rhs);
2464 : : /* Build a new statement with the RHS and LHS exchanged. */
2465 : 11689946 : if (TREE_CODE (rhs) == SSA_NAME)
2466 : : {
2467 : 4867002 : gimple *defstmt = SSA_NAME_DEF_STMT (rhs);
2468 : 4867002 : new_stmt = gimple_build_assign (rhs, lhs);
2469 : 4867002 : SSA_NAME_DEF_STMT (rhs) = defstmt;
2470 : : }
2471 : : else
2472 : 6822944 : new_stmt = gimple_build_assign (rhs, lhs);
2473 : 23379892 : gimple_set_vuse (new_stmt, gimple_vuse (stmt));
2474 : 11689946 : expr_hash_elt *elt = NULL;
2475 : 11689946 : cached_lhs = m_avail_exprs_stack->lookup_avail_expr (new_stmt, false,
2476 : : false, &elt);
2477 : 11689946 : if (cached_lhs
2478 : 695387 : && operand_equal_p (rhs, cached_lhs, 0)
2479 : 11838804 : && refs_same_for_tbaa_p (elt->expr ()->kind == EXPR_SINGLE
2480 : 74429 : ? elt->expr ()->ops.single.rhs
2481 : : : NULL_TREE, lhs))
2482 : : {
2483 : 73945 : basic_block bb = gimple_bb (stmt);
2484 : 73945 : unlink_stmt_vdef (stmt);
2485 : 73945 : if (gsi_remove (si, true))
2486 : : {
2487 : 0 : bitmap_set_bit (need_eh_cleanup, bb->index);
2488 : 0 : if (dump_file && (dump_flags & TDF_DETAILS))
2489 : 0 : fprintf (dump_file, " Flagged to clear EH edges.\n");
2490 : : }
2491 : 73945 : release_defs (stmt);
2492 : 73945 : *removed_p = true;
2493 : 73945 : return retval;
2494 : : }
2495 : : }
2496 : :
2497 : : /* If this statement was not redundant, we may still be able to simplify
2498 : : it, which may in turn allow other part of DOM or other passes to do
2499 : : a better job. */
2500 : 50638507 : test_for_singularity (stmt, m_avail_exprs_stack);
2501 : : }
2502 : :
2503 : : /* Record any additional equivalences created by this statement. */
2504 : 148373120 : if (is_gimple_assign (stmt))
2505 : 44928606 : record_equivalences_from_stmt (stmt, may_optimize_p, m_avail_exprs_stack);
2506 : :
2507 : : /* If STMT is a COND_EXPR or SWITCH_EXPR and it was modified, then we may
2508 : : know where it goes. */
2509 : 296746240 : if (gimple_modified_p (stmt) || modified_p)
2510 : : {
2511 : 3630106 : tree val = NULL;
2512 : :
2513 : 3630106 : if (gimple_code (stmt) == GIMPLE_COND)
2514 : 399894 : val = fold_binary_loc (gimple_location (stmt),
2515 : : gimple_cond_code (stmt), boolean_type_node,
2516 : : gimple_cond_lhs (stmt),
2517 : : gimple_cond_rhs (stmt));
2518 : 3230212 : else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt))
2519 : 2030 : val = gimple_switch_index (swtch_stmt);
2520 : :
2521 : 401924 : if (val && TREE_CODE (val) == INTEGER_CST)
2522 : : {
2523 : 51231 : retval = find_taken_edge (bb, val);
2524 : 51231 : if (retval)
2525 : : {
2526 : : /* Fix the condition to be either true or false. */
2527 : 51231 : if (gimple_code (stmt) == GIMPLE_COND)
2528 : : {
2529 : 51219 : if (integer_zerop (val))
2530 : 26897 : gimple_cond_make_false (as_a <gcond *> (stmt));
2531 : 24322 : else if (integer_onep (val))
2532 : 24322 : gimple_cond_make_true (as_a <gcond *> (stmt));
2533 : : else
2534 : 0 : gcc_unreachable ();
2535 : :
2536 : 51219 : gimple_set_modified (stmt, true);
2537 : : }
2538 : :
2539 : : /* Further simplifications may be possible. */
2540 : 51231 : cfg_altered = true;
2541 : : }
2542 : : }
2543 : :
2544 : 3630106 : update_stmt_if_modified (stmt);
2545 : :
2546 : : /* If we simplified a statement in such a way as to be shown that it
2547 : : cannot trap, update the eh information and the cfg to match. */
2548 : 3630106 : if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
2549 : : {
2550 : 1605 : bitmap_set_bit (need_eh_cleanup, bb->index);
2551 : 1605 : if (dump_file && (dump_flags & TDF_DETAILS))
2552 : 0 : fprintf (dump_file, " Flagged to clear EH edges.\n");
2553 : : }
2554 : :
2555 : 3630106 : if (!was_noreturn
2556 : 3630106 : && is_gimple_call (stmt) && gimple_call_noreturn_p (stmt))
2557 : 5 : need_noreturn_fixup.safe_push (stmt);
2558 : : }
2559 : : return retval;
2560 : : }
|
