Line data Source code
1 : /* SSA Dominator optimizations for trees
2 : Copyright (C) 2001-2026 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 "tree-cfgcleanup.h"
46 : #include "dbgcnt.h"
47 : #include "alloc-pool.h"
48 : #include "tree-vrp.h"
49 : #include "vr-values.h"
50 : #include "gimple-range.h"
51 : #include "gimple-range-path.h"
52 : #include "alias.h"
53 :
54 : /* This file implements optimizations on the dominator tree. */
55 :
56 : /* Structure for recording edge equivalences.
57 :
58 : Computing and storing the edge equivalences instead of creating
59 : them on-demand can save significant amounts of time, particularly
60 : for pathological cases involving switch statements.
61 :
62 : These structures live for a single iteration of the dominator
63 : optimizer in the edge's AUX field. At the end of an iteration we
64 : free each of these structures. */
65 : class edge_info
66 : {
67 : public:
68 : typedef std::pair <tree, tree> equiv_pair;
69 : edge_info (edge);
70 : ~edge_info ();
71 :
72 : /* Record a simple LHS = RHS equivalence. This may trigger
73 : calls to derive_equivalences. */
74 : void record_simple_equiv (tree, tree);
75 :
76 : /* If traversing this edge creates simple equivalences, we store
77 : them as LHS/RHS pairs within this vector. */
78 : vec<equiv_pair> simple_equivalences;
79 :
80 : /* Traversing an edge may also indicate one or more particular conditions
81 : are true or false. */
82 : vec<cond_equivalence> cond_equivalences;
83 :
84 : private:
85 : /* Derive equivalences by walking the use-def chains. */
86 : void derive_equivalences (tree, tree, int);
87 : };
88 :
89 : /* Track whether or not we have changed the control flow graph. */
90 : static bool cfg_altered;
91 :
92 : /* Bitmap of blocks that have had EH statements cleaned. We should
93 : remove their dead edges eventually. */
94 : static bitmap need_eh_cleanup;
95 : static vec<gimple *> need_noreturn_fixup;
96 :
97 : /* Bitmap of SSA names that have no use in an assignment or call that
98 : defines an SSA name, so back_propagate_equivalences has nothing to do
99 : for them. A bit is cleared when DOM adds such a use. */
100 : static bitmap names_without_foldable_uses;
101 :
102 : /* Statistics for dominator optimizations. */
103 : struct opt_stats_d
104 : {
105 : long num_stmts;
106 : long num_exprs_considered;
107 : long num_re;
108 : long num_const_prop;
109 : long num_copy_prop;
110 : };
111 :
112 : static struct opt_stats_d opt_stats;
113 :
114 : /* Local functions. */
115 : static void record_equality (tree, tree, class const_and_copies *);
116 : static void record_equivalences_from_phis (basic_block);
117 : static void dump_dominator_optimization_stats (FILE *file,
118 : hash_table<expr_elt_hasher> *);
119 : static void record_temporary_equivalences (edge, class const_and_copies *,
120 : class avail_exprs_stack *, bitmap);
121 :
122 : /* Constructor for EDGE_INFO. An EDGE_INFO instance is always
123 : associated with an edge E. */
124 :
125 37361231 : edge_info::edge_info (edge e)
126 : {
127 : /* Free the old one associated with E, if it exists and
128 : associate our new object with E. */
129 37361231 : free_dom_edge_info (e);
130 37361231 : e->aux = this;
131 :
132 : /* And initialize the embedded vectors. */
133 37361231 : simple_equivalences = vNULL;
134 37361231 : cond_equivalences = vNULL;
135 37361231 : }
136 :
137 : /* Destructor just needs to release the vectors. */
138 :
139 37361231 : edge_info::~edge_info (void)
140 : {
141 37361231 : this->cond_equivalences.release ();
142 37361231 : this->simple_equivalences.release ();
143 37361231 : }
144 :
145 : /* NAME is known to have the value VALUE, which must be a constant.
146 :
147 : Walk through its use-def chain to see if there are other equivalences
148 : we might be able to derive.
149 :
150 : RECURSION_LIMIT controls how far back we recurse through the use-def
151 : chains. */
152 :
153 : void
154 13537486 : edge_info::derive_equivalences (tree name, tree value, int recursion_limit)
155 : {
156 15682432 : if (TREE_CODE (name) != SSA_NAME || TREE_CODE (value) != INTEGER_CST)
157 : return;
158 :
159 : /* This records the equivalence for the toplevel object. Do
160 : this before checking the recursion limit. */
161 15682140 : simple_equivalences.safe_push (equiv_pair (name, value));
162 :
163 : /* Limit how far up the use-def chains we are willing to walk. */
164 15682140 : if (recursion_limit == 0)
165 : return;
166 :
167 : /* We can walk up the use-def chains to potentially find more
168 : equivalences. */
169 15669304 : gimple *def_stmt = SSA_NAME_DEF_STMT (name);
170 15669304 : if (is_gimple_assign (def_stmt))
171 : {
172 10250761 : enum tree_code code = gimple_assign_rhs_code (def_stmt);
173 10250761 : switch (code)
174 : {
175 : /* If the result of an OR is zero, then its operands are, too. */
176 588838 : case BIT_IOR_EXPR:
177 588838 : if (integer_zerop (value))
178 : {
179 323273 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
180 323273 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
181 :
182 323273 : value = build_zero_cst (TREE_TYPE (rhs1));
183 323273 : derive_equivalences (rhs1, value, recursion_limit - 1);
184 323273 : value = build_zero_cst (TREE_TYPE (rhs2));
185 323273 : derive_equivalences (rhs2, value, recursion_limit - 1);
186 : }
187 : break;
188 :
189 : /* If the result of an AND is nonzero, then its operands are, too. */
190 1101883 : case BIT_AND_EXPR:
191 1101883 : if (!integer_zerop (value))
192 : {
193 465179 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
194 465179 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
195 :
196 : /* If either operand has a boolean range, then we
197 : know its value must be one, otherwise we just know it
198 : is nonzero. The former is clearly useful, I haven't
199 : seen cases where the latter is helpful yet. */
200 465179 : if (TREE_CODE (rhs1) == SSA_NAME)
201 : {
202 465179 : if (ssa_name_has_boolean_range (rhs1))
203 : {
204 291749 : value = build_one_cst (TREE_TYPE (rhs1));
205 291749 : derive_equivalences (rhs1, value, recursion_limit - 1);
206 : }
207 : }
208 465179 : if (TREE_CODE (rhs2) == SSA_NAME)
209 : {
210 294382 : if (ssa_name_has_boolean_range (rhs2))
211 : {
212 291466 : value = build_one_cst (TREE_TYPE (rhs2));
213 291466 : derive_equivalences (rhs2, value, recursion_limit - 1);
214 : }
215 : }
216 : }
217 : break;
218 :
219 : /* If LHS is an SSA_NAME and RHS is a constant integer and LHS was
220 : set via a widening type conversion, then we may be able to record
221 : additional equivalences. */
222 450965 : CASE_CONVERT:
223 450965 : {
224 450965 : tree rhs = gimple_assign_rhs1 (def_stmt);
225 450965 : tree rhs_type = TREE_TYPE (rhs);
226 450965 : if (INTEGRAL_TYPE_P (rhs_type)
227 447980 : && (TYPE_PRECISION (TREE_TYPE (name))
228 447980 : >= TYPE_PRECISION (rhs_type))
229 700957 : && int_fits_type_p (value, rhs_type))
230 238166 : derive_equivalences (rhs,
231 : fold_convert (rhs_type, value),
232 : recursion_limit - 1);
233 : break;
234 : }
235 :
236 : /* We can invert the operation of these codes trivially if
237 : one of the RHS operands is a constant to produce a known
238 : value for the other RHS operand. */
239 1058274 : case POINTER_PLUS_EXPR:
240 1058274 : case PLUS_EXPR:
241 1058274 : {
242 1058274 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
243 1058274 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
244 :
245 : /* If the second argument is a constant, then we can compute
246 : a constant value for the first one. */
247 1058274 : if (TREE_CODE (rhs2) == INTEGER_CST
248 1003968 : && TREE_CODE (rhs1) == SSA_NAME)
249 1003966 : derive_equivalences (rhs1,
250 1003966 : fold_binary (MINUS_EXPR, TREE_TYPE (rhs1),
251 : value, rhs2),
252 : recursion_limit - 1);
253 : break;
254 : }
255 :
256 : /* If one of the operands is a constant, then we can compute
257 : the value of the other operand. If both operands are
258 : SSA_NAMEs, then they must be equal if the result is zero. */
259 75962 : case MINUS_EXPR:
260 75962 : {
261 75962 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
262 75962 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
263 :
264 : /* If either argument is a constant, then we can compute
265 : a constant value for the nonconstant argument. */
266 75962 : if (TREE_CODE (rhs1) == INTEGER_CST
267 666 : && TREE_CODE (rhs2) == SSA_NAME)
268 666 : derive_equivalences (rhs2,
269 666 : fold_binary (MINUS_EXPR, TREE_TYPE (rhs1),
270 : rhs1, value),
271 : recursion_limit - 1);
272 75296 : else if (TREE_CODE (rhs2) == INTEGER_CST
273 30230 : && TREE_CODE (rhs1) == SSA_NAME)
274 30230 : derive_equivalences (rhs1,
275 30230 : fold_binary (PLUS_EXPR, TREE_TYPE (rhs1),
276 : value, rhs2),
277 : recursion_limit - 1);
278 45066 : else if (integer_zerop (value))
279 : {
280 16351 : tree cond = build2 (EQ_EXPR, boolean_type_node,
281 : gimple_assign_rhs1 (def_stmt),
282 : gimple_assign_rhs2 (def_stmt));
283 16351 : tree inverted = invert_truthvalue (cond);
284 16351 : record_conditions (&this->cond_equivalences, cond, inverted);
285 : }
286 : break;
287 : }
288 :
289 761138 : case EQ_EXPR:
290 761138 : case NE_EXPR:
291 761138 : {
292 347631 : if ((code == EQ_EXPR && integer_onep (value))
293 904939 : || (code == NE_EXPR && integer_zerop (value)))
294 : {
295 465690 : tree rhs1 = gimple_assign_rhs1 (def_stmt);
296 465690 : tree rhs2 = gimple_assign_rhs2 (def_stmt);
297 :
298 : /* If the second argument is a constant, then record the
299 : first argument as being the same as that constant.
300 :
301 : If neither operand is a constant, then we have a
302 : conditional name == name equivalence. */
303 465690 : if (TREE_CODE (rhs2) == INTEGER_CST)
304 242869 : derive_equivalences (rhs1, rhs2, recursion_limit - 1);
305 : }
306 : else
307 : {
308 295448 : tree cond = build2 (code, boolean_type_node,
309 : gimple_assign_rhs1 (def_stmt),
310 295448 : gimple_assign_rhs2 (def_stmt));
311 295448 : tree inverted = invert_truthvalue (cond);
312 295448 : if (integer_zerop (value))
313 143801 : std::swap (cond, inverted);
314 295448 : record_conditions (&this->cond_equivalences, cond, inverted);
315 : }
316 : break;
317 : }
318 :
319 : /* For BIT_NOT and NEGATE, we can just apply the operation to the
320 : VALUE to get the new equivalence. It will always be a constant
321 : so we can recurse. */
322 14310 : case BIT_NOT_EXPR:
323 14310 : case NEGATE_EXPR:
324 14310 : {
325 14310 : tree rhs = gimple_assign_rhs1 (def_stmt);
326 14310 : tree res;
327 : /* If this is a NOT and the operand has a boolean range, then we
328 : know its value must be zero or one. We are not supposed to
329 : have a BIT_NOT_EXPR for boolean types with precision > 1 in
330 : the general case, see e.g. the handling of TRUTH_NOT_EXPR in
331 : the gimplifier, but it can be generated by match.pd out of
332 : a BIT_XOR_EXPR wrapped in a BIT_AND_EXPR. Now the handling
333 : of BIT_AND_EXPR above already forces a specific semantics for
334 : boolean types with precision > 1 so we must do the same here,
335 : otherwise we could change the semantics of TRUTH_NOT_EXPR for
336 : boolean types with precision > 1. */
337 14310 : if (code == BIT_NOT_EXPR
338 14055 : && TREE_CODE (rhs) == SSA_NAME
339 28365 : && ssa_name_has_boolean_range (rhs))
340 : {
341 13602 : if ((TREE_INT_CST_LOW (value) & 1) == 0)
342 6188 : res = build_one_cst (TREE_TYPE (rhs));
343 : else
344 7414 : res = build_zero_cst (TREE_TYPE (rhs));
345 : }
346 : else
347 708 : res = fold_build1 (code, TREE_TYPE (rhs), value);
348 14310 : derive_equivalences (rhs, res, recursion_limit - 1);
349 14310 : break;
350 : }
351 :
352 6199391 : default:
353 6199391 : {
354 6199391 : if (TREE_CODE_CLASS (code) == tcc_comparison)
355 : {
356 531628 : tree cond = build2 (code, boolean_type_node,
357 : gimple_assign_rhs1 (def_stmt),
358 531628 : gimple_assign_rhs2 (def_stmt));
359 531628 : tree inverted = invert_truthvalue (cond);
360 531628 : if (integer_zerop (value))
361 225999 : std::swap (cond, inverted);
362 531628 : record_conditions (&this->cond_equivalences, cond, inverted);
363 531628 : break;
364 : }
365 : break;
366 : }
367 : }
368 : }
369 : }
370 :
371 : void
372 16291732 : edge_info::record_simple_equiv (tree lhs, tree rhs)
373 : {
374 : /* If the RHS is a constant, then we may be able to derive
375 : further equivalences. Else just record the name = name
376 : equivalence. */
377 16291732 : if (TREE_CODE (rhs) == INTEGER_CST)
378 12922464 : derive_equivalences (lhs, rhs, 4);
379 : else
380 3369268 : simple_equivalences.safe_push (equiv_pair (lhs, rhs));
381 16291732 : }
382 :
383 : /* Free the edge_info data attached to E, if it exists and
384 : clear e->aux. */
385 :
386 : void
387 135338283 : free_dom_edge_info (edge e)
388 : {
389 135338283 : class edge_info *edge_info = (class edge_info *)e->aux;
390 :
391 135338283 : if (edge_info)
392 37361231 : delete edge_info;
393 135338283 : e->aux = NULL;
394 135338283 : }
395 :
396 : /* Free all EDGE_INFO structures associated with edges in the CFG.
397 : If a particular edge can be threaded, copy the redirection
398 : target from the EDGE_INFO structure into the edge's AUX field
399 : as required by code to update the CFG and SSA graph for
400 : jump threading. */
401 :
402 : static void
403 2136688 : free_all_edge_infos (void)
404 : {
405 2136688 : basic_block bb;
406 2136688 : edge_iterator ei;
407 2136688 : edge e;
408 :
409 24366268 : FOR_EACH_BB_FN (bb, cfun)
410 : {
411 53641136 : FOR_EACH_EDGE (e, ei, bb->preds)
412 31411556 : free_dom_edge_info (e);
413 : }
414 2136688 : }
415 :
416 : /* We have finished optimizing BB, record any information implied by
417 : taking a specific outgoing edge from BB. */
418 :
419 : static void
420 46511505 : record_edge_info (basic_block bb)
421 : {
422 46511505 : gimple_stmt_iterator gsi = gsi_last_bb (bb);
423 46511505 : class edge_info *edge_info;
424 :
425 : /* Free all the outgoing edge info data associated with
426 : BB's outgoing edges. */
427 46511505 : edge e;
428 46511505 : edge_iterator ei;
429 111275394 : FOR_EACH_EDGE (e, ei, bb->succs)
430 64763889 : free_dom_edge_info (e);
431 :
432 46511505 : if (! gsi_end_p (gsi))
433 : {
434 40185904 : gimple *stmt = gsi_stmt (gsi);
435 40185904 : location_t loc = gimple_location (stmt);
436 :
437 40185904 : if (gimple_code (stmt) == GIMPLE_SWITCH)
438 : {
439 72103 : gswitch *switch_stmt = as_a <gswitch *> (stmt);
440 72103 : tree index = gimple_switch_index (switch_stmt);
441 :
442 72103 : if (TREE_CODE (index) == SSA_NAME)
443 : {
444 72088 : int i;
445 72088 : int n_labels = gimple_switch_num_labels (switch_stmt);
446 : /* info contains NULL, error_mark_node or a value.
447 : error_mark signifies there are multiple values already.
448 : A NULL signifies there it is uninitialized.
449 : A value signifies that is the only value on that edge
450 : to that bb. */
451 72088 : tree *info = XCNEWVEC (tree, last_basic_block_for_fn (cfun));
452 :
453 679188 : for (i = 0; i < n_labels; i++)
454 : {
455 535012 : tree label = gimple_switch_label (switch_stmt, i);
456 535012 : basic_block target_bb
457 535012 : = label_to_block (cfun, CASE_LABEL (label));
458 : /* The default case is a case with multiple values.
459 : If the value is already set then it has multiple values. */
460 535012 : if (CASE_HIGH (label)
461 510710 : || !CASE_LOW (label)
462 973634 : || info[target_bb->index])
463 145408 : info[target_bb->index] = error_mark_node;
464 : else
465 : /* Record the one value that can be on that edge to the
466 : target_bb. */
467 389604 : info[target_bb->index] = CASE_LOW (label);
468 : }
469 :
470 551040 : FOR_EACH_EDGE (e, ei, bb->succs)
471 : {
472 478952 : basic_block target_bb = e->dest;
473 478952 : tree value = info[target_bb->index];
474 :
475 478952 : if (value != NULL && value != error_mark_node)
476 : {
477 364433 : tree x = fold_convert_loc (loc, TREE_TYPE (index),
478 : value);
479 364433 : edge_info = new class edge_info (e);
480 364433 : edge_info->record_simple_equiv (index, x);
481 : }
482 : }
483 72088 : free (info);
484 : }
485 : }
486 :
487 : /* A COND_EXPR may create equivalences too. */
488 40185904 : if (gimple_code (stmt) == GIMPLE_COND)
489 : {
490 18689764 : edge true_edge;
491 18689764 : edge false_edge;
492 :
493 18689764 : tree op0 = gimple_cond_lhs (stmt);
494 18689764 : tree op1 = gimple_cond_rhs (stmt);
495 18689764 : enum tree_code code = gimple_cond_code (stmt);
496 :
497 18689764 : extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
498 :
499 : /* Special case comparing booleans against a constant as we
500 : know the value of OP0 on both arms of the branch. i.e., we
501 : can record an equivalence for OP0 rather than COND.
502 :
503 : However, don't do this if the constant isn't zero or one.
504 : Such conditionals will get optimized more thoroughly during
505 : the domwalk. */
506 18689764 : if ((code == EQ_EXPR || code == NE_EXPR)
507 14318654 : && TREE_CODE (op0) == SSA_NAME
508 14127819 : && ssa_name_has_boolean_range (op0)
509 2073880 : && is_gimple_min_invariant (op1)
510 20698584 : && (integer_zerop (op1) || integer_onep (op1)))
511 : {
512 2008820 : tree true_val = constant_boolean_node (true, TREE_TYPE (op0));
513 2008820 : tree false_val = constant_boolean_node (false, TREE_TYPE (op0));
514 :
515 2008820 : if (code == EQ_EXPR)
516 : {
517 77925 : edge_info = new class edge_info (true_edge);
518 116174 : edge_info->record_simple_equiv (op0,
519 77925 : (integer_zerop (op1)
520 : ? false_val : true_val));
521 77925 : edge_info = new class edge_info (false_edge);
522 116174 : edge_info->record_simple_equiv (op0,
523 77925 : (integer_zerop (op1)
524 : ? true_val : false_val));
525 : }
526 : else
527 : {
528 1930895 : edge_info = new class edge_info (true_edge);
529 1934248 : edge_info->record_simple_equiv (op0,
530 1930895 : (integer_zerop (op1)
531 : ? true_val : false_val));
532 1930895 : edge_info = new class edge_info (false_edge);
533 1934248 : edge_info->record_simple_equiv (op0,
534 1930895 : (integer_zerop (op1)
535 : ? false_val : true_val));
536 : }
537 : }
538 16680944 : else if (TREE_CODE (op0) == SSA_NAME
539 16680944 : && (TREE_CODE (op1) == SSA_NAME
540 12288749 : || is_gimple_min_invariant (op1)))
541 : {
542 16489579 : tree cond = build2 (code, boolean_type_node, op0, op1);
543 16489579 : tree inverted = invert_truthvalue_loc (loc, cond);
544 16489579 : bool can_infer_simple_equiv
545 17201863 : = !(HONOR_SIGNED_ZEROS (op1) && real_maybe_zerop (op1))
546 16896458 : && !DECIMAL_FLOAT_MODE_P (element_mode (TREE_TYPE (op1)));
547 16489579 : class edge_info *edge_info;
548 :
549 16489579 : edge_info = new class edge_info (true_edge);
550 16489579 : record_conditions (&edge_info->cond_equivalences, cond, inverted);
551 :
552 16489579 : if (can_infer_simple_equiv && code == EQ_EXPR)
553 5585093 : edge_info->record_simple_equiv (op0, op1);
554 :
555 16489579 : edge_info = new class edge_info (false_edge);
556 16489579 : record_conditions (&edge_info->cond_equivalences, inverted, cond);
557 :
558 16489579 : if (can_infer_simple_equiv && TREE_CODE (inverted) == EQ_EXPR)
559 6324566 : edge_info->record_simple_equiv (op0, op1);
560 : }
561 : }
562 : }
563 46511505 : }
564 :
565 : class dom_jt_state : public jt_state
566 : {
567 : public:
568 2136688 : dom_jt_state (const_and_copies *copies, avail_exprs_stack *avails)
569 2136688 : : m_copies (copies), m_avails (avails)
570 : {
571 2136688 : bitmap_tree_view (m_blocks_on_stack);
572 2136688 : }
573 17279832 : void push (edge e) override
574 : {
575 17279832 : m_copies->push_marker ();
576 17279832 : m_avails->push_marker ();
577 17279832 : jt_state::push (e);
578 17279832 : }
579 17279832 : void pop () override
580 : {
581 17279832 : m_copies->pop_to_marker ();
582 17279832 : m_avails->pop_to_marker ();
583 17279832 : jt_state::pop ();
584 17279832 : }
585 16012996 : void register_equivs_edge (edge e) override
586 : {
587 16012996 : record_temporary_equivalences (e, m_copies, m_avails, m_blocks_on_stack);
588 16012996 : }
589 : void register_equiv (tree dest, tree src, bool update) override;
590 66646228 : bitmap get_blocks_on_stack () { return m_blocks_on_stack; }
591 : private:
592 : const_and_copies *m_copies;
593 : avail_exprs_stack *m_avails;
594 : /* Set of blocks on the stack, to be used for medium-fast
595 : dominance queries in back_propagate_equivalences. */
596 : auto_bitmap m_blocks_on_stack;
597 : };
598 :
599 : void
600 21715237 : dom_jt_state::register_equiv (tree dest, tree src, bool)
601 : {
602 21715237 : m_copies->record_const_or_copy (dest, src);
603 21715237 : }
604 :
605 2136688 : class dom_jt_simplifier : public hybrid_jt_simplifier
606 : {
607 : public:
608 2136688 : dom_jt_simplifier (avail_exprs_stack *avails, gimple_ranger *ranger,
609 : path_range_query *query)
610 4273376 : : hybrid_jt_simplifier (ranger, query), m_avails (avails) { }
611 :
612 : private:
613 : tree simplify (gimple *, gimple *, basic_block, jt_state *) override;
614 : avail_exprs_stack *m_avails;
615 : };
616 :
617 : tree
618 32207204 : dom_jt_simplifier::simplify (gimple *stmt, gimple *within_stmt,
619 : basic_block bb, jt_state *state)
620 : {
621 : /* First see if the conditional is in the hash table. */
622 32207204 : tree cached_lhs = m_avails->lookup_avail_expr (stmt, false, true);
623 32207204 : if (cached_lhs)
624 : return cached_lhs;
625 :
626 : /* Otherwise call the ranger if possible. */
627 31364705 : if (state)
628 8895092 : return hybrid_jt_simplifier::simplify (stmt, within_stmt, bb, state);
629 :
630 : return NULL;
631 : }
632 :
633 4273376 : class dom_opt_dom_walker : public dom_walker
634 : {
635 : public:
636 2136688 : dom_opt_dom_walker (cdi_direction direction,
637 : jump_threader *threader,
638 : dom_jt_state *state,
639 : gimple_ranger *ranger,
640 : const_and_copies *const_and_copies,
641 : avail_exprs_stack *avail_exprs_stack)
642 4273376 : : dom_walker (direction, REACHABLE_BLOCKS)
643 : {
644 2136688 : m_ranger = ranger;
645 2136688 : m_state = state;
646 2136688 : m_const_and_copies = const_and_copies;
647 2136688 : m_avail_exprs_stack = avail_exprs_stack;
648 2136688 : m_threader = threader;
649 : }
650 :
651 : edge before_dom_children (basic_block) final override;
652 : void after_dom_children (basic_block) final override;
653 :
654 : private:
655 :
656 : /* Unwindable equivalences, both const/copy and expression varieties. */
657 : class const_and_copies *m_const_and_copies;
658 : class avail_exprs_stack *m_avail_exprs_stack;
659 :
660 : /* Optimize a single statement within a basic block using the
661 : various tables maintained by DOM. Returns the taken edge if
662 : the statement is a conditional with a statically determined
663 : value. */
664 : edge optimize_stmt (basic_block, gimple_stmt_iterator *, bool *);
665 :
666 : void set_global_ranges_from_unreachable_edges (basic_block);
667 :
668 : void fold_cond (gimple *);
669 : void record_equivalences_from_incoming_edge (basic_block);
670 : void eliminate_redundant_computations (gimple_stmt_iterator *);
671 : void record_equivalences_from_stmt (gimple *, int);
672 : tree const_or_copy_of_stmt (gimple *);
673 :
674 : jump_threader *m_threader;
675 : gimple_ranger *m_ranger;
676 : dom_jt_state *m_state;
677 : };
678 :
679 : /* Jump threading, redundancy elimination and const/copy propagation.
680 :
681 : This pass may expose new symbols that need to be renamed into SSA. For
682 : every new symbol exposed, its corresponding bit will be set in
683 : VARS_TO_RENAME. */
684 :
685 : namespace {
686 :
687 : const pass_data pass_data_dominator =
688 : {
689 : GIMPLE_PASS, /* type */
690 : "dom", /* name */
691 : OPTGROUP_NONE, /* optinfo_flags */
692 : TV_TREE_SSA_DOMINATOR_OPTS, /* tv_id */
693 : ( PROP_cfg | PROP_ssa ), /* properties_required */
694 : 0, /* properties_provided */
695 : 0, /* properties_destroyed */
696 : 0, /* todo_flags_start */
697 : ( TODO_cleanup_cfg | TODO_update_ssa ), /* todo_flags_finish */
698 : };
699 :
700 : class pass_dominator : public gimple_opt_pass
701 : {
702 : public:
703 883608 : pass_dominator (gcc::context *ctxt)
704 : : gimple_opt_pass (pass_data_dominator, ctxt),
705 1767216 : may_peel_loop_headers_p (false)
706 : {}
707 :
708 : /* opt_pass methods: */
709 589072 : opt_pass * clone () final override { return new pass_dominator (m_ctxt); }
710 883608 : void set_pass_param (unsigned int n, bool param) final override
711 : {
712 883608 : gcc_assert (n == 0);
713 883608 : may_peel_loop_headers_p = param;
714 883608 : }
715 2137479 : bool gate (function *) final override { return flag_tree_dom != 0; }
716 : unsigned int execute (function *) final override;
717 :
718 : private:
719 : /* This flag is used to prevent loops from being peeled repeatedly in jump
720 : threading; it will be removed once we preserve loop structures throughout
721 : the compilation -- we will be able to mark the affected loops directly in
722 : jump threading, and avoid peeling them next time. */
723 : bool may_peel_loop_headers_p;
724 : }; // class pass_dominator
725 :
726 : unsigned int
727 2136688 : pass_dominator::execute (function *fun)
728 : {
729 2136688 : memset (&opt_stats, 0, sizeof (opt_stats));
730 :
731 : /* Create our hash tables. */
732 2136688 : hash_table<expr_elt_hasher> *avail_exprs
733 2136688 : = new hash_table<expr_elt_hasher> (1024);
734 2136688 : class avail_exprs_stack *avail_exprs_stack
735 2136688 : = new class avail_exprs_stack (avail_exprs);
736 2136688 : class const_and_copies *const_and_copies = new class const_and_copies ();
737 2136688 : need_eh_cleanup = BITMAP_ALLOC (NULL);
738 2136688 : need_noreturn_fixup.create (0);
739 2136688 : names_without_foldable_uses = BITMAP_ALLOC (NULL);
740 2136688 : bitmap_tree_view (names_without_foldable_uses);
741 :
742 2136688 : calculate_dominance_info (CDI_DOMINATORS);
743 2136688 : cfg_altered = false;
744 :
745 : /* We need to know loop structures in order to avoid destroying them
746 : in jump threading. Note that we still can e.g. thread through loop
747 : headers to an exit edge, or through loop header to the loop body, assuming
748 : that we update the loop info.
749 :
750 : TODO: We don't need to set LOOPS_HAVE_PREHEADERS generally, but due
751 : to several overly conservative bail-outs in jump threading, case
752 : gcc.dg/tree-ssa/pr21417.c can't be threaded if loop preheader is
753 : missing. We should improve jump threading in future then
754 : LOOPS_HAVE_PREHEADERS won't be needed here. */
755 2136688 : loop_optimizer_init (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES
756 : | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS);
757 :
758 : /* We need accurate information regarding back edges in the CFG
759 : for jump threading; this may include back edges that are not part of
760 : a single loop. */
761 2136688 : mark_dfs_back_edges ();
762 :
763 : /* We want to create the edge info structures before the dominator walk
764 : so that they'll be in place for the jump threader, particularly when
765 : threading through a join block.
766 :
767 : The conditions will be lazily updated with global equivalences as
768 : we reach them during the dominator walk. */
769 2136688 : basic_block bb;
770 24366268 : FOR_EACH_BB_FN (bb, fun)
771 22229580 : record_edge_info (bb);
772 :
773 : /* Recursively walk the dominator tree optimizing statements. */
774 2136688 : gimple_ranger *ranger = enable_ranger (fun);
775 2136688 : path_range_query path_query (*ranger);
776 2136688 : dom_jt_simplifier simplifier (avail_exprs_stack, ranger, &path_query);
777 2136688 : dom_jt_state state (const_and_copies, avail_exprs_stack);
778 2136688 : jump_threader threader (&simplifier, &state);
779 2136688 : dom_opt_dom_walker walker (CDI_DOMINATORS,
780 : &threader,
781 : &state,
782 : ranger,
783 : const_and_copies,
784 2136688 : avail_exprs_stack);
785 2136688 : walker.walk (fun->cfg->x_entry_block_ptr);
786 :
787 2136688 : ranger->export_global_ranges ();
788 2136688 : disable_ranger (fun);
789 :
790 : /* Look for blocks where we cleared EDGE_EXECUTABLE on an outgoing
791 : edge. When found, remove jump threads which contain any outgoing
792 : edge from the affected block. */
793 2136688 : if (cfg_altered)
794 : {
795 5121677 : FOR_EACH_BB_FN (bb, fun)
796 : {
797 5056657 : edge_iterator ei;
798 5056657 : edge e;
799 :
800 : /* First see if there are any edges without EDGE_EXECUTABLE
801 : set. */
802 5056657 : bool found = false;
803 12134383 : FOR_EACH_EDGE (e, ei, bb->succs)
804 : {
805 7321056 : if ((e->flags & EDGE_EXECUTABLE) == 0)
806 : {
807 : found = true;
808 : break;
809 : }
810 : }
811 :
812 : /* If there were any such edges found, then remove jump threads
813 : containing any edge leaving BB. */
814 5056657 : if (found)
815 710755 : FOR_EACH_EDGE (e, ei, bb->succs)
816 467425 : threader.remove_jump_threads_including (e);
817 : }
818 : }
819 :
820 2136688 : {
821 2136688 : gimple_stmt_iterator gsi;
822 2136688 : basic_block bb;
823 24366268 : FOR_EACH_BB_FN (bb, fun)
824 : {
825 231836769 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
826 187377609 : update_stmt_if_modified (gsi_stmt (gsi));
827 : }
828 : }
829 :
830 : /* If we exposed any new variables, go ahead and put them into
831 : SSA form now, before we handle jump threading. This simplifies
832 : interactions between rewriting of _DECL nodes into SSA form
833 : and rewriting SSA_NAME nodes into SSA form after block
834 : duplication and CFG manipulation. */
835 2136688 : update_ssa (TODO_update_ssa);
836 :
837 2136688 : free_all_edge_infos ();
838 :
839 : /* Thread jumps, creating duplicate blocks as needed. */
840 2136688 : cfg_altered |= threader.thread_through_all_blocks (may_peel_loop_headers_p);
841 :
842 2136688 : if (cfg_altered)
843 125639 : free_dominance_info (CDI_DOMINATORS);
844 :
845 : /* Removal of statements may make some EH edges dead. Purge
846 : such edges from the CFG as needed. */
847 2136688 : if (!bitmap_empty_p (need_eh_cleanup))
848 : {
849 558 : unsigned i;
850 558 : bitmap_iterator bi;
851 :
852 : /* Jump threading may have created forwarder blocks from blocks
853 : needing EH cleanup; the new successor of these blocks, which
854 : has inherited from the original block, needs the cleanup.
855 : Don't clear bits in the bitmap, as that can break the bitmap
856 : iterator. */
857 1801 : EXECUTE_IF_SET_IN_BITMAP (need_eh_cleanup, 0, i, bi)
858 : {
859 1243 : basic_block bb = BASIC_BLOCK_FOR_FN (fun, i);
860 1243 : if (bb == NULL)
861 0 : continue;
862 2565 : while (single_succ_p (bb)
863 1377 : && (single_succ_edge (bb)->flags
864 151 : & (EDGE_EH|EDGE_DFS_BACK)) == 0)
865 134 : bb = single_succ (bb);
866 1243 : if (bb == EXIT_BLOCK_PTR_FOR_FN (fun))
867 55 : continue;
868 1188 : if ((unsigned) bb->index != i)
869 59 : bitmap_set_bit (need_eh_cleanup, bb->index);
870 : }
871 :
872 558 : gimple_purge_all_dead_eh_edges (need_eh_cleanup);
873 558 : bitmap_clear (need_eh_cleanup);
874 : }
875 :
876 : /* Fixup stmts that became noreturn calls. This may require splitting
877 : blocks and thus isn't possible during the dominator walk or before
878 : jump threading finished. Do this in reverse order so we don't
879 : inadvertently remove a stmt we want to fixup by visiting a dominating
880 : now noreturn call first. */
881 2136691 : while (!need_noreturn_fixup.is_empty ())
882 : {
883 3 : gimple *stmt = need_noreturn_fixup.pop ();
884 3 : if (dump_file && dump_flags & TDF_DETAILS)
885 : {
886 0 : fprintf (dump_file, "Fixing up noreturn call ");
887 0 : print_gimple_stmt (dump_file, stmt, 0);
888 0 : fprintf (dump_file, "\n");
889 : }
890 3 : fixup_noreturn_call (stmt);
891 : }
892 :
893 2136688 : statistics_counter_event (fun, "Redundant expressions eliminated",
894 2136688 : opt_stats.num_re);
895 2136688 : statistics_counter_event (fun, "Constants propagated",
896 2136688 : opt_stats.num_const_prop);
897 2136688 : statistics_counter_event (fun, "Copies propagated",
898 2136688 : opt_stats.num_copy_prop);
899 :
900 : /* Debugging dumps. */
901 2136688 : if (dump_file && (dump_flags & TDF_STATS))
902 36 : dump_dominator_optimization_stats (dump_file, avail_exprs);
903 :
904 2136688 : loop_optimizer_finalize ();
905 :
906 : /* Delete our main hashtable. */
907 2136688 : delete avail_exprs;
908 2136688 : avail_exprs = NULL;
909 :
910 : /* Free asserted bitmaps and stacks. */
911 2136688 : BITMAP_FREE (need_eh_cleanup);
912 2136688 : need_noreturn_fixup.release ();
913 2136688 : BITMAP_FREE (names_without_foldable_uses);
914 2136688 : delete avail_exprs_stack;
915 2136688 : delete const_and_copies;
916 :
917 2136688 : return 0;
918 2136688 : }
919 :
920 : } // anon namespace
921 :
922 : gimple_opt_pass *
923 294536 : make_pass_dominator (gcc::context *ctxt)
924 : {
925 294536 : return new pass_dominator (ctxt);
926 : }
927 :
928 : /* Valueize hook for gimple_fold_stmt_to_constant_1. */
929 :
930 : static tree
931 35332731 : dom_valueize (tree t)
932 : {
933 35332731 : if (TREE_CODE (t) == SSA_NAME)
934 : {
935 25382475 : tree tem = SSA_NAME_VALUE (t);
936 20171843 : if (tem)
937 3183733 : return tem;
938 : }
939 : return t;
940 : }
941 :
942 : /* We have just found an equivalence for LHS on an edge E.
943 : Look backwards to other uses of LHS and see if we can derive
944 : additional equivalences that are valid on edge E. */
945 : static void
946 12387014 : back_propagate_equivalences (tree lhs, edge e,
947 : class const_and_copies *const_and_copies,
948 : bitmap domby)
949 : {
950 12387014 : use_operand_p use_p;
951 12387014 : imm_use_iterator iter;
952 12387014 : basic_block dest = e->dest;
953 12387014 : bool domok = (dom_info_state (CDI_DOMINATORS) == DOM_OK);
954 12387014 : unsigned version = SSA_NAME_VERSION (lhs);
955 :
956 : /* If an earlier walk found no use of LHS that can produce an
957 : equivalence, there is nothing to do. With checking enabled, walk
958 : the uses anyway to verify that no such use has been added. */
959 12387014 : bool cached_p = bitmap_bit_p (names_without_foldable_uses, version);
960 12387014 : if (cached_p && !flag_checking)
961 49 : return;
962 :
963 : /* Iterate over the uses of LHS to see if any dominate E->dest.
964 : If so, they may create useful equivalences too.
965 :
966 : ??? If the code gets re-organized to a worklist to catch more
967 : indirect opportunities and it is made to handle PHIs then this
968 : should only consider use_stmts in basic-blocks we have already visited. */
969 12386965 : bool foldable_use_p = false;
970 53422662 : FOR_EACH_IMM_USE_FAST (use_p, iter, lhs)
971 : {
972 41035697 : gimple *use_stmt = USE_STMT (use_p);
973 :
974 : /* Filter out statements that can never produce a useful
975 : equivalence. gimple_fold_stmt_to_constant_1 does not fold
976 : PHI nodes. */
977 41035697 : if (gimple_code (use_stmt) == GIMPLE_PHI)
978 3498073 : continue;
979 37537624 : tree lhs2 = gimple_get_lhs (use_stmt);
980 37537624 : if (!lhs2 || TREE_CODE (lhs2) != SSA_NAME)
981 29930665 : continue;
982 :
983 7606959 : gcc_checking_assert (!cached_p);
984 7606959 : foldable_use_p = true;
985 :
986 : /* Often the use is in DEST, which we trivially know we can't use.
987 : This is cheaper than the dominator set tests below. */
988 7606959 : if (dest == gimple_bb (use_stmt))
989 114906 : continue;
990 :
991 7492053 : if (domok)
992 : {
993 4358163 : if (!dominated_by_p (CDI_DOMINATORS, dest, gimple_bb (use_stmt)))
994 2205554 : continue;
995 : }
996 : else
997 : {
998 : /* We can use the set of BBs on the stack from a domwalk
999 : for a medium fast way to query dominance. Profiling
1000 : has shown non-fast query dominance tests here can be fairly
1001 : expensive. */
1002 : /* This tests if USE_STMT does not dominate DEST. */
1003 3133890 : if (!bitmap_bit_p (domby, gimple_bb (use_stmt)->index))
1004 2158867 : continue;
1005 : }
1006 :
1007 : /* At this point USE_STMT dominates DEST and may result in a
1008 : useful equivalence. Try to simplify its RHS to a constant
1009 : or SSA_NAME. */
1010 3127632 : tree res = gimple_fold_stmt_to_constant_1 (use_stmt, dom_valueize,
1011 : no_follow_ssa_edges);
1012 3127632 : if (res && (TREE_CODE (res) == SSA_NAME || is_gimple_min_invariant (res)))
1013 2464965 : record_equality (lhs2, res, const_and_copies);
1014 12386965 : }
1015 :
1016 12386965 : if (!foldable_use_p)
1017 8809339 : bitmap_set_bit (names_without_foldable_uses, version);
1018 : }
1019 :
1020 : /* Record into CONST_AND_COPIES and AVAIL_EXPRS_STACK any equivalences implied
1021 : by traversing edge E (which are cached in E->aux).
1022 :
1023 : Callers are responsible for managing the unwinding markers. */
1024 : static void
1025 34095374 : record_temporary_equivalences (edge e,
1026 : class const_and_copies *const_and_copies,
1027 : class avail_exprs_stack *avail_exprs_stack,
1028 : bitmap blocks_on_stack)
1029 : {
1030 34095374 : int i;
1031 34095374 : class edge_info *edge_info = (class edge_info *) e->aux;
1032 :
1033 : /* If we have info associated with this edge, record it into
1034 : our equivalence tables. */
1035 34095374 : if (edge_info)
1036 : {
1037 : cond_equivalence *eq;
1038 : /* If we have 0 = COND or 1 = COND equivalences, record them
1039 : into our expression hash tables. */
1040 68797527 : for (i = 0; edge_info->cond_equivalences.iterate (i, &eq); ++i)
1041 44270072 : avail_exprs_stack->record_cond (eq);
1042 :
1043 : edge_info::equiv_pair *seq;
1044 36914469 : for (i = 0; edge_info->simple_equivalences.iterate (i, &seq); ++i)
1045 : {
1046 12387014 : tree lhs = seq->first;
1047 12387014 : if (!lhs || TREE_CODE (lhs) != SSA_NAME)
1048 0 : continue;
1049 :
1050 : /* Record the simple NAME = VALUE equivalence. */
1051 12387014 : tree rhs = seq->second;
1052 :
1053 : /* If this is a SSA_NAME = SSA_NAME equivalence and one operand is
1054 : cheaper to compute than the other, then set up the equivalence
1055 : such that we replace the expensive one with the cheap one.
1056 :
1057 : If they are the same cost to compute, then do not record
1058 : anything. */
1059 12387014 : if (TREE_CODE (lhs) == SSA_NAME && TREE_CODE (rhs) == SSA_NAME)
1060 : {
1061 1788489 : gimple *rhs_def = SSA_NAME_DEF_STMT (rhs);
1062 1788489 : int rhs_cost = estimate_num_insns (rhs_def, &eni_size_weights);
1063 :
1064 1788489 : gimple *lhs_def = SSA_NAME_DEF_STMT (lhs);
1065 1788489 : int lhs_cost = estimate_num_insns (lhs_def, &eni_size_weights);
1066 :
1067 1788489 : if (rhs_cost > lhs_cost)
1068 198034 : record_equality (rhs, lhs, const_and_copies);
1069 1590455 : else if (rhs_cost < lhs_cost)
1070 482348 : record_equality (lhs, rhs, const_and_copies);
1071 : }
1072 : else
1073 10598525 : record_equality (lhs, rhs, const_and_copies);
1074 :
1075 :
1076 : /* Any equivalence found for LHS may result in additional
1077 : equivalences for other uses of LHS that we have already
1078 : processed. */
1079 12387014 : back_propagate_equivalences (lhs, e, const_and_copies,
1080 : blocks_on_stack);
1081 : }
1082 : }
1083 34095374 : }
1084 :
1085 : /* PHI nodes can create equivalences too.
1086 :
1087 : Ignoring any alternatives which are the same as the result, if
1088 : all the alternatives are equal, then the PHI node creates an
1089 : equivalence. */
1090 :
1091 : static void
1092 24281925 : record_equivalences_from_phis (basic_block bb)
1093 : {
1094 24281925 : gphi_iterator gsi;
1095 :
1096 33843609 : for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
1097 : {
1098 9561684 : gphi *phi = gsi.phi ();
1099 :
1100 : /* We might eliminate the PHI, so advance GSI now. */
1101 9561684 : gsi_next (&gsi);
1102 :
1103 9561684 : tree lhs = gimple_phi_result (phi);
1104 9561684 : tree rhs = NULL;
1105 9561684 : size_t i;
1106 :
1107 17265526 : for (i = 0; i < gimple_phi_num_args (phi); i++)
1108 : {
1109 16166284 : tree t = gimple_phi_arg_def (phi, i);
1110 :
1111 : /* Ignore alternatives which are the same as our LHS. Since
1112 : LHS is a PHI_RESULT, it is known to be a SSA_NAME, so we
1113 : can simply compare pointers. */
1114 16166284 : if (lhs == t)
1115 31657 : continue;
1116 :
1117 : /* If the associated edge is not marked as executable, then it
1118 : can be ignored. */
1119 16134627 : if ((gimple_phi_arg_edge (phi, i)->flags & EDGE_EXECUTABLE) == 0)
1120 135677 : continue;
1121 :
1122 15998950 : t = dom_valueize (t);
1123 :
1124 : /* If T is an SSA_NAME and its associated edge is a backedge,
1125 : then quit as we cannot utilize this equivalence. */
1126 15998950 : if (TREE_CODE (t) == SSA_NAME
1127 15998950 : && (gimple_phi_arg_edge (phi, i)->flags & EDGE_DFS_BACK))
1128 : break;
1129 :
1130 : /* If we have not processed an alternative yet, then set
1131 : RHS to this alternative. */
1132 12892253 : if (rhs == NULL)
1133 : rhs = t;
1134 : /* If we have processed an alternative (stored in RHS), then
1135 : see if it is equal to this one. If it isn't, then stop
1136 : the search. */
1137 5927438 : else if (! operand_equal_for_phi_arg_p (rhs, t))
1138 : break;
1139 : }
1140 :
1141 : /* If we had no interesting alternatives, then all the RHS alternatives
1142 : must have been the same as LHS. */
1143 9561684 : if (!rhs)
1144 2596869 : rhs = lhs;
1145 :
1146 : /* If we managed to iterate through each PHI alternative without
1147 : breaking out of the loop, then we have a PHI which may create
1148 : a useful equivalence. We do not need to record unwind data for
1149 : this, since this is a true assignment and not an equivalence
1150 : inferred from a comparison. All uses of this ssa name are dominated
1151 : by this assignment, so unwinding just costs time and space. */
1152 9561684 : if (i == gimple_phi_num_args (phi))
1153 : {
1154 1099242 : if (may_propagate_copy (lhs, rhs))
1155 608480 : set_ssa_name_value (lhs, rhs);
1156 981524 : else if (virtual_operand_p (lhs))
1157 : {
1158 490318 : gimple *use_stmt;
1159 490318 : imm_use_iterator iter;
1160 490318 : use_operand_p use_p;
1161 : /* For virtual operands we have to propagate into all uses as
1162 : otherwise we will create overlapping life-ranges. */
1163 1477805 : FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
1164 2042538 : FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1165 1021269 : SET_USE (use_p, rhs);
1166 490318 : if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
1167 70 : SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs) = 1;
1168 490318 : gimple_stmt_iterator tmp_gsi = gsi_for_stmt (phi);
1169 490318 : remove_phi_node (&tmp_gsi, true);
1170 : }
1171 : }
1172 : }
1173 24281925 : }
1174 :
1175 : /* Return true if all uses of NAME are dominated by STMT or feed STMT
1176 : via a chain of single immediate uses. */
1177 :
1178 : static bool
1179 430351 : all_uses_feed_or_dominated_by_stmt (tree name, gimple *stmt)
1180 : {
1181 430351 : use_operand_p use_p, use2_p;
1182 430351 : imm_use_iterator iter;
1183 430351 : basic_block stmt_bb = gimple_bb (stmt);
1184 :
1185 1786234 : FOR_EACH_IMM_USE_FAST (use_p, iter, name)
1186 : {
1187 1585599 : gimple *use_stmt = USE_STMT (use_p), *use_stmt2;
1188 2932797 : if (use_stmt == stmt
1189 1439463 : || is_gimple_debug (use_stmt)
1190 2364628 : || (gimple_bb (use_stmt) != stmt_bb
1191 612089 : && dominated_by_p (CDI_DOMINATORS,
1192 612089 : gimple_bb (use_stmt), stmt_bb)))
1193 1347198 : continue;
1194 : while (use_stmt != stmt
1195 446378 : && is_gimple_assign (use_stmt)
1196 389879 : && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME
1197 829952 : && single_imm_use (gimple_assign_lhs (use_stmt),
1198 : &use2_p, &use_stmt2))
1199 216662 : use_stmt = use_stmt2;
1200 238401 : if (use_stmt != stmt)
1201 229716 : return false;
1202 229716 : }
1203 200635 : return true;
1204 : }
1205 :
1206 : /* Handle
1207 : _4 = x_3 & 31;
1208 : if (_4 != 0)
1209 : goto <bb 6>;
1210 : else
1211 : goto <bb 7>;
1212 : <bb 6>:
1213 : __builtin_unreachable ();
1214 : <bb 7>:
1215 :
1216 : If x_3 has no other immediate uses (checked by caller), var is the
1217 : x_3 var, we can clear low 5 bits from the non-zero bitmask. */
1218 :
1219 : static void
1220 179445 : maybe_set_nonzero_bits (edge e, tree var)
1221 : {
1222 179445 : basic_block cond_bb = e->src;
1223 358890 : gcond *cond = safe_dyn_cast <gcond *> (*gsi_last_bb (cond_bb));
1224 179445 : tree cst;
1225 :
1226 179445 : if (cond == NULL
1227 179445 : || gimple_cond_code (cond) != ((e->flags & EDGE_TRUE_VALUE)
1228 179445 : ? EQ_EXPR : NE_EXPR)
1229 53256 : || TREE_CODE (gimple_cond_lhs (cond)) != SSA_NAME
1230 2062 : || !integer_zerop (gimple_cond_rhs (cond)))
1231 : return;
1232 :
1233 1987 : gimple *stmt = SSA_NAME_DEF_STMT (gimple_cond_lhs (cond));
1234 1987 : if (!is_gimple_assign (stmt)
1235 1965 : || gimple_assign_rhs_code (stmt) != BIT_AND_EXPR
1236 2014 : || TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST)
1237 : return;
1238 1 : if (gimple_assign_rhs1 (stmt) != var)
1239 : {
1240 1 : gimple *stmt2;
1241 :
1242 1 : if (TREE_CODE (gimple_assign_rhs1 (stmt)) != SSA_NAME)
1243 : return;
1244 1 : stmt2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
1245 1 : if (!gimple_assign_cast_p (stmt2)
1246 0 : || gimple_assign_rhs1 (stmt2) != var
1247 0 : || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt2))
1248 1 : || (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (stmt)))
1249 0 : != TYPE_PRECISION (TREE_TYPE (var))))
1250 : return;
1251 : }
1252 0 : cst = gimple_assign_rhs2 (stmt);
1253 0 : if (POINTER_TYPE_P (TREE_TYPE (var)))
1254 : {
1255 0 : struct ptr_info_def *pi = SSA_NAME_PTR_INFO (var);
1256 0 : if (pi && pi->misalign)
1257 0 : return;
1258 0 : wide_int w = wi::bit_not (wi::to_wide (cst));
1259 0 : unsigned int bits = wi::ctz (w);
1260 0 : if (bits == 0 || bits >= HOST_BITS_PER_INT)
1261 0 : return;
1262 0 : unsigned int align = 1U << bits;
1263 0 : if (pi == NULL || pi->align < align)
1264 0 : set_ptr_info_alignment (get_ptr_info (var), align, 0);
1265 0 : }
1266 : else
1267 0 : set_nonzero_bits (var, wi::bit_and_not (get_nonzero_bits (var),
1268 0 : wi::to_wide (cst)));
1269 : }
1270 :
1271 : /* Set global ranges that can be determined from the C->M edge:
1272 :
1273 : <bb C>:
1274 : ...
1275 : if (something)
1276 : goto <bb N>;
1277 : else
1278 : goto <bb M>;
1279 : <bb N>:
1280 : __builtin_unreachable ();
1281 : <bb M>:
1282 : */
1283 :
1284 : void
1285 24281925 : dom_opt_dom_walker::set_global_ranges_from_unreachable_edges (basic_block bb)
1286 : {
1287 24281925 : edge pred_e = single_pred_edge_ignoring_loop_edges (bb, false);
1288 24281925 : if (!pred_e)
1289 : return;
1290 :
1291 18076765 : gimple *stmt = *gsi_last_bb (pred_e->src);
1292 18076765 : if (!stmt
1293 15227836 : || gimple_code (stmt) != GIMPLE_COND
1294 30571316 : || !assert_unreachable_fallthru_edge_p (pred_e))
1295 : return;
1296 :
1297 : // Bail if the condition leading to the unreachable edge has 2 ssa-names.
1298 : // See PR 125501.
1299 243760 : if ((TREE_CODE (gimple_cond_lhs (stmt)) == SSA_NAME
1300 243760 : && TREE_CODE (gimple_cond_rhs (stmt)) == SSA_NAME))
1301 : return;
1302 :
1303 240933 : tree name;
1304 671284 : FOR_EACH_GORI_EXPORT_NAME (m_ranger->gori_ssa (), pred_e->src, name)
1305 430351 : if (all_uses_feed_or_dominated_by_stmt (name, stmt)
1306 : // The condition must post-dominate the definition point.
1307 630986 : && (SSA_NAME_IS_DEFAULT_DEF (name)
1308 200511 : || (gimple_bb (SSA_NAME_DEF_STMT (name))
1309 200511 : == pred_e->src)))
1310 : {
1311 194109 : value_range r (TREE_TYPE (name));
1312 :
1313 194109 : if (m_ranger->range_on_edge (r, pred_e, name)
1314 194109 : && !r.varying_p ()
1315 373623 : && !r.undefined_p ())
1316 : {
1317 179445 : set_range_info (name, r);
1318 179445 : maybe_set_nonzero_bits (pred_e, name);
1319 : }
1320 194109 : }
1321 : }
1322 :
1323 : /* Record any equivalences created by the incoming edge to BB. If BB
1324 : has more than one incoming edge, then no equivalence is created. */
1325 :
1326 : void
1327 24281925 : dom_opt_dom_walker::record_equivalences_from_incoming_edge (basic_block bb)
1328 : {
1329 24281925 : edge e;
1330 24281925 : basic_block parent;
1331 :
1332 : /* If our parent block ended with a control statement, then we may be
1333 : able to record some equivalences based on which outgoing edge from
1334 : the parent was followed. */
1335 24281925 : parent = get_immediate_dominator (CDI_DOMINATORS, bb);
1336 :
1337 24281925 : e = single_pred_edge_ignoring_loop_edges (bb, true);
1338 :
1339 : /* If we had a single incoming edge from our parent block, then enter
1340 : any data associated with the edge into our tables. */
1341 24281925 : if (e && e->src == parent)
1342 18082378 : record_temporary_equivalences (e, m_const_and_copies, m_avail_exprs_stack,
1343 18082378 : m_state->get_blocks_on_stack ());
1344 24281925 : }
1345 :
1346 : /* Dump statistics for the hash table HTAB. */
1347 :
1348 : static void
1349 36 : htab_statistics (FILE *file, const hash_table<expr_elt_hasher> &htab)
1350 : {
1351 68 : fprintf (file, "size " HOST_SIZE_T_PRINT_DEC ", " HOST_SIZE_T_PRINT_DEC
1352 : " elements, %f collision/search ratio\n",
1353 36 : (fmt_size_t) htab.size (),
1354 36 : (fmt_size_t) htab.elements (),
1355 : htab.collisions ());
1356 36 : }
1357 :
1358 : /* Dump SSA statistics on FILE. */
1359 :
1360 : static void
1361 36 : dump_dominator_optimization_stats (FILE *file,
1362 : hash_table<expr_elt_hasher> *avail_exprs)
1363 : {
1364 36 : fprintf (file, "Total number of statements: %6ld\n\n",
1365 : opt_stats.num_stmts);
1366 36 : fprintf (file, "Exprs considered for dominator optimizations: %6ld\n",
1367 : opt_stats.num_exprs_considered);
1368 :
1369 36 : fprintf (file, "\nHash table statistics:\n");
1370 :
1371 36 : fprintf (file, " avail_exprs: ");
1372 36 : htab_statistics (file, *avail_exprs);
1373 36 : }
1374 :
1375 :
1376 : /* Similarly, but assume that X and Y are the two operands of an EQ_EXPR.
1377 : This constrains the cases in which we may treat this as assignment. */
1378 :
1379 : static void
1380 13743872 : record_equality (tree x, tree y, class const_and_copies *const_and_copies)
1381 : {
1382 13743872 : tree prev_x = NULL, prev_y = NULL;
1383 :
1384 13743872 : if (tree_swap_operands_p (x, y))
1385 622442 : std::swap (x, y);
1386 :
1387 : /* Most of the time tree_swap_operands_p does what we want. But there
1388 : are cases where we know one operand is better for copy propagation than
1389 : the other. Given no other code cares about ordering of equality
1390 : comparison operators for that purpose, we just handle the special cases
1391 : here. */
1392 13743872 : if (TREE_CODE (x) == SSA_NAME && TREE_CODE (y) == SSA_NAME)
1393 : {
1394 : /* If one operand is a single use operand, then make it
1395 : X. This will preserve its single use properly and if this
1396 : conditional is eliminated, the computation of X can be
1397 : eliminated as well. */
1398 1153557 : if (has_single_use (y) && ! has_single_use (x))
1399 : std::swap (x, y);
1400 : }
1401 13743872 : if (TREE_CODE (x) == SSA_NAME)
1402 13743872 : prev_x = SSA_NAME_VALUE (x);
1403 13743872 : if (TREE_CODE (y) == SSA_NAME)
1404 1153557 : prev_y = SSA_NAME_VALUE (y);
1405 :
1406 : /* If one of the previous values is invariant, or invariant in more loops
1407 : (by depth), then use that.
1408 : Otherwise it doesn't matter which value we choose, just so
1409 : long as we canonicalize on one value. */
1410 13743872 : if (is_gimple_min_invariant (y))
1411 : ;
1412 1153557 : else if (is_gimple_min_invariant (x))
1413 : prev_x = x, x = y, y = prev_x, prev_x = prev_y;
1414 1153557 : else if (prev_x && is_gimple_min_invariant (prev_x))
1415 : x = y, y = prev_x, prev_x = prev_y;
1416 1062491 : else if (prev_y)
1417 13743872 : y = prev_y;
1418 :
1419 : /* After the swapping, we must have one SSA_NAME. */
1420 13743872 : if (TREE_CODE (x) != SSA_NAME)
1421 : return;
1422 :
1423 : /* For IEEE, -0.0 == 0.0, so we don't necessarily know the sign of a
1424 : variable compared against zero. If we're honoring signed zeros,
1425 : then we cannot record this value unless we know that the value is
1426 : nonzero. */
1427 13743872 : if (HONOR_SIGNED_ZEROS (x)
1428 13743872 : && (TREE_CODE (y) != REAL_CST
1429 172132 : || real_equal (&dconst0, &TREE_REAL_CST (y))))
1430 : return;
1431 :
1432 13743534 : const_and_copies->record_const_or_copy (x, y, prev_x);
1433 : }
1434 :
1435 : /* Returns true when STMT is a simple iv increment. It detects the
1436 : following situation:
1437 :
1438 : i_1 = phi (..., i_k)
1439 : [...]
1440 : i_j = i_{j-1} for each j : 2 <= j <= k-1
1441 : [...]
1442 : i_k = i_{k-1} +/- ... */
1443 :
1444 : bool
1445 44211461 : simple_iv_increment_p (gimple *stmt)
1446 : {
1447 44211461 : enum tree_code code;
1448 44211461 : tree lhs, preinc;
1449 44211461 : gimple *phi;
1450 44211461 : size_t i;
1451 :
1452 44211461 : if (gimple_code (stmt) != GIMPLE_ASSIGN)
1453 : return false;
1454 :
1455 33932857 : lhs = gimple_assign_lhs (stmt);
1456 33932857 : if (TREE_CODE (lhs) != SSA_NAME)
1457 : return false;
1458 :
1459 33932857 : code = gimple_assign_rhs_code (stmt);
1460 33932857 : if (code != PLUS_EXPR
1461 33932857 : && code != MINUS_EXPR
1462 33932857 : && code != POINTER_PLUS_EXPR)
1463 : return false;
1464 :
1465 8131974 : preinc = gimple_assign_rhs1 (stmt);
1466 8131974 : if (TREE_CODE (preinc) != SSA_NAME)
1467 : return false;
1468 :
1469 7850214 : phi = SSA_NAME_DEF_STMT (preinc);
1470 7876131 : while (gimple_code (phi) != GIMPLE_PHI)
1471 : {
1472 : /* Follow trivial copies, but not the DEF used in a back edge,
1473 : so that we don't prevent coalescing. */
1474 5326308 : if (!gimple_assign_ssa_name_copy_p (phi))
1475 : return false;
1476 25917 : preinc = gimple_assign_rhs1 (phi);
1477 25917 : phi = SSA_NAME_DEF_STMT (preinc);
1478 : }
1479 :
1480 5004195 : for (i = 0; i < gimple_phi_num_args (phi); i++)
1481 4056125 : if (gimple_phi_arg_def (phi, i) == lhs)
1482 : return true;
1483 :
1484 : return false;
1485 : }
1486 :
1487 : /* Propagate know values from SSA_NAME_VALUE into the PHI nodes of the
1488 : successors of BB. */
1489 :
1490 : static void
1491 24281925 : cprop_into_successor_phis (basic_block bb,
1492 : class const_and_copies *const_and_copies)
1493 : {
1494 24281925 : edge e;
1495 24281925 : edge_iterator ei;
1496 :
1497 57687473 : FOR_EACH_EDGE (e, ei, bb->succs)
1498 : {
1499 33405548 : int indx;
1500 33405548 : gphi_iterator gsi;
1501 :
1502 : /* If this is an abnormal edge, then we do not want to copy propagate
1503 : into the PHI alternative associated with this edge. */
1504 33405548 : if (e->flags & EDGE_ABNORMAL)
1505 19669194 : continue;
1506 :
1507 33391505 : gsi = gsi_start_phis (e->dest);
1508 33391505 : if (gsi_end_p (gsi))
1509 19655151 : continue;
1510 :
1511 : /* We may have an equivalence associated with this edge. While
1512 : we cannot propagate it into non-dominated blocks, we can
1513 : propagate them into PHIs in non-dominated blocks. */
1514 :
1515 : /* Push the unwind marker so we can reset the const and copies
1516 : table back to its original state after processing this edge. */
1517 13736354 : const_and_copies->push_marker ();
1518 :
1519 : /* Extract and record any simple NAME = VALUE equivalences.
1520 :
1521 : Don't bother with [01] = COND equivalences, they're not useful
1522 : here. */
1523 13736354 : class edge_info *edge_info = (class edge_info *) e->aux;
1524 :
1525 13736354 : if (edge_info)
1526 : {
1527 : edge_info::equiv_pair *seq;
1528 8624772 : for (int i = 0; edge_info->simple_equivalences.iterate (i, &seq); ++i)
1529 : {
1530 3314913 : tree lhs = seq->first;
1531 3314913 : tree rhs = seq->second;
1532 :
1533 3314913 : if (lhs && TREE_CODE (lhs) == SSA_NAME)
1534 3314913 : const_and_copies->record_const_or_copy (lhs, rhs);
1535 : }
1536 :
1537 : }
1538 :
1539 13736354 : indx = e->dest_idx;
1540 37862691 : for ( ; !gsi_end_p (gsi); gsi_next (&gsi))
1541 : {
1542 24126337 : tree new_val;
1543 24126337 : use_operand_p orig_p;
1544 24126337 : tree orig_val;
1545 24126337 : gphi *phi = gsi.phi ();
1546 :
1547 : /* The alternative may be associated with a constant, so verify
1548 : it is an SSA_NAME before doing anything with it. */
1549 24126337 : orig_p = gimple_phi_arg_imm_use_ptr (phi, indx);
1550 24126337 : orig_val = get_use_from_ptr (orig_p);
1551 24126337 : if (TREE_CODE (orig_val) != SSA_NAME)
1552 3258767 : continue;
1553 :
1554 : /* If we have *ORIG_P in our constant/copy table, then replace
1555 : ORIG_P with its value in our constant/copy table. */
1556 20867570 : new_val = SSA_NAME_VALUE (orig_val);
1557 20867570 : if (new_val
1558 20867570 : && new_val != orig_val
1559 20867570 : && may_propagate_copy (orig_val, new_val))
1560 1215685 : propagate_value (orig_p, new_val);
1561 : }
1562 :
1563 13736354 : const_and_copies->pop_to_marker ();
1564 : }
1565 24281925 : }
1566 :
1567 : edge
1568 24281925 : dom_opt_dom_walker::before_dom_children (basic_block bb)
1569 : {
1570 24281925 : gimple_stmt_iterator gsi;
1571 :
1572 24281925 : if (dump_file && (dump_flags & TDF_DETAILS))
1573 764 : fprintf (dump_file, "\n\nOptimizing block #%d\n\n", bb->index);
1574 :
1575 : /* Push a marker on the stacks of local information so that we know how
1576 : far to unwind when we finalize this block. */
1577 24281925 : m_avail_exprs_stack->push_marker ();
1578 24281925 : m_const_and_copies->push_marker ();
1579 24281925 : bitmap_set_bit (m_state->get_blocks_on_stack (), bb->index);
1580 :
1581 24281925 : record_equivalences_from_incoming_edge (bb);
1582 24281925 : set_global_ranges_from_unreachable_edges (bb);
1583 :
1584 : /* PHI nodes can create equivalences too. */
1585 24281925 : record_equivalences_from_phis (bb);
1586 :
1587 : /* Create equivalences from redundant PHIs. PHIs are only truly
1588 : redundant when they exist in the same block, so push another
1589 : marker and unwind right afterwards. */
1590 24281925 : m_avail_exprs_stack->push_marker ();
1591 33353291 : for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1592 9071366 : eliminate_redundant_computations (&gsi);
1593 24281925 : m_avail_exprs_stack->pop_to_marker ();
1594 :
1595 24281925 : edge taken_edge = NULL;
1596 : /* Initialize visited flag ahead of us, it has undefined state on
1597 : pass entry. */
1598 234858804 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1599 186294954 : gimple_set_visited (gsi_stmt (gsi), false);
1600 396747670 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
1601 : {
1602 : /* Do not optimize a stmt twice, substitution might end up with
1603 : _3 = _3 which is not valid. */
1604 372465745 : if (gimple_visited_p (gsi_stmt (gsi)))
1605 : {
1606 186170632 : gsi_next (&gsi);
1607 186170632 : continue;
1608 : }
1609 :
1610 186295113 : bool removed_p = false;
1611 186295113 : taken_edge = this->optimize_stmt (bb, &gsi, &removed_p);
1612 186295113 : if (!removed_p)
1613 : {
1614 186170632 : gimple *stmt = gsi_stmt (gsi);
1615 186170632 : gimple_set_visited (stmt, true);
1616 :
1617 : /* Propagation and folding may have added uses to STMT, which
1618 : back_propagate_equivalences has to consider. */
1619 186170632 : tree lhs = gimple_get_lhs (stmt);
1620 186170632 : if (lhs && TREE_CODE (lhs) == SSA_NAME)
1621 : {
1622 36880523 : ssa_op_iter iter;
1623 36880523 : tree use;
1624 72736313 : FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
1625 35855790 : bitmap_clear_bit (names_without_foldable_uses,
1626 35855790 : SSA_NAME_VERSION (use));
1627 : }
1628 : }
1629 :
1630 : /* Go back and visit stmts inserted by folding after substituting
1631 : into the stmt at gsi. */
1632 186295113 : if (gsi_end_p (gsi))
1633 : {
1634 2819 : gcc_checking_assert (removed_p);
1635 2819 : gsi = gsi_last_bb (bb);
1636 2819 : while (!gsi_end_p (gsi) && !gimple_visited_p (gsi_stmt (gsi)))
1637 0 : gsi_prev (&gsi);
1638 : }
1639 : else
1640 : {
1641 186292453 : do
1642 : {
1643 186292453 : gsi_prev (&gsi);
1644 : }
1645 372584747 : while (!gsi_end_p (gsi) && !gimple_visited_p (gsi_stmt (gsi)));
1646 : }
1647 186295113 : if (gsi_end_p (gsi))
1648 40136954 : gsi = gsi_start_bb (bb);
1649 : else
1650 166226636 : gsi_next (&gsi);
1651 : }
1652 :
1653 : /* Now prepare to process dominated blocks. */
1654 24281925 : record_edge_info (bb);
1655 24281925 : cprop_into_successor_phis (bb, m_const_and_copies);
1656 24281925 : if (taken_edge && !dbg_cnt (dom_unreachable_edges))
1657 0 : return NULL;
1658 :
1659 : return taken_edge;
1660 : }
1661 :
1662 : /* We have finished processing the dominator children of BB, perform
1663 : any finalization actions in preparation for leaving this node in
1664 : the dominator tree. */
1665 :
1666 : void
1667 24281925 : dom_opt_dom_walker::after_dom_children (basic_block bb)
1668 : {
1669 24281925 : if (param_dom_jump_threading)
1670 24281176 : m_threader->thread_outgoing_edges (bb);
1671 24281925 : bitmap_clear_bit (m_state->get_blocks_on_stack (), bb->index);
1672 24281925 : m_avail_exprs_stack->pop_to_marker ();
1673 24281925 : m_const_and_copies->pop_to_marker ();
1674 24281925 : }
1675 :
1676 : /* Return the constant STMT computes, and barring that, an operand its
1677 : result is equivalent to. NULL if neither. */
1678 :
1679 : tree
1680 65023174 : dom_opt_dom_walker::const_or_copy_of_stmt (gimple *stmt)
1681 : {
1682 65023174 : if (tree val = m_ranger->value_of_stmt (stmt))
1683 : return val;
1684 :
1685 : /* We could remove this gate, but we'd end up with tons of useless
1686 : replacements (casts, copies, etc). Best to keep it to binops, which is
1687 : what the original code did. */
1688 64301023 : if (!is_gimple_assign (stmt)
1689 109209253 : || gimple_assign_rhs_class (stmt) != GIMPLE_BINARY_RHS)
1690 : return NULL_TREE;
1691 :
1692 11925266 : tree lhs = gimple_assign_lhs (stmt);
1693 11925266 : tree rhs1 = gimple_assign_rhs1 (stmt);
1694 11925266 : tree rhs2 = gimple_assign_rhs2 (stmt);
1695 11925266 : if (m_ranger->relation ().query (stmt, lhs, rhs1) == VREL_EQ)
1696 : return rhs1;
1697 11921836 : if (m_ranger->relation ().query (stmt, lhs, rhs2) == VREL_EQ)
1698 43 : return rhs2;
1699 :
1700 : return NULL_TREE;
1701 : }
1702 :
1703 : /* Search for redundant computations in STMT. If any are found, then
1704 : replace them with the variable holding the result of the computation.
1705 :
1706 : If safe, record this expression into the tables. */
1707 :
1708 : void
1709 65509960 : dom_opt_dom_walker::eliminate_redundant_computations (gimple_stmt_iterator *gsi)
1710 : {
1711 65509960 : tree expr_type;
1712 65509960 : tree cached_lhs;
1713 65509960 : tree def;
1714 65509960 : bool insert = true;
1715 65509960 : bool assigns_var_p = false;
1716 :
1717 65509960 : gimple *stmt = gsi_stmt (*gsi);
1718 :
1719 65509960 : if (gimple_code (stmt) == GIMPLE_PHI)
1720 9071366 : def = gimple_phi_result (stmt);
1721 : else
1722 56438594 : def = gimple_get_lhs (stmt);
1723 :
1724 : /* Certain expressions on the RHS can be optimized away, but cannot
1725 : themselves be entered into the hash tables. */
1726 65509960 : if (! def
1727 56146118 : || TREE_CODE (def) != SSA_NAME
1728 43072559 : || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def)
1729 33999913 : || gimple_vdef (stmt)
1730 : /* Do not record equivalences for increments of ivs. This would create
1731 : overlapping live ranges for a very questionable gain. */
1732 108571833 : || simple_iv_increment_p (stmt))
1733 : insert = false;
1734 :
1735 : /* Check if the expression has been computed before. */
1736 65509960 : cached_lhs = m_avail_exprs_stack->lookup_avail_expr (stmt, insert, true);
1737 :
1738 : /* Otherwise, ask the ranger. */
1739 65509960 : if (!cached_lhs)
1740 65023174 : cached_lhs = const_or_copy_of_stmt (stmt);
1741 :
1742 65509960 : opt_stats.num_exprs_considered++;
1743 :
1744 : /* Get the type of the expression we are trying to optimize. */
1745 65509960 : if (is_gimple_assign (stmt))
1746 : {
1747 45795821 : expr_type = TREE_TYPE (gimple_assign_lhs (stmt));
1748 45795821 : assigns_var_p = true;
1749 : }
1750 19714139 : else if (gimple_code (stmt) == GIMPLE_COND)
1751 9327798 : expr_type = boolean_type_node;
1752 10386341 : else if (is_gimple_call (stmt))
1753 : {
1754 1278931 : gcc_assert (gimple_call_lhs (stmt));
1755 1278931 : expr_type = TREE_TYPE (gimple_call_lhs (stmt));
1756 1278931 : assigns_var_p = true;
1757 : }
1758 9107410 : else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt))
1759 36044 : expr_type = TREE_TYPE (gimple_switch_index (swtch_stmt));
1760 9071366 : else if (gimple_code (stmt) == GIMPLE_PHI)
1761 : /* We can't propagate into a phi, so the logic below doesn't apply.
1762 : Instead record an equivalence between the cached LHS and the
1763 : PHI result of this statement, provided they are in the same block.
1764 : This should be sufficient to kill the redundant phi. */
1765 : {
1766 9071366 : if (def && cached_lhs)
1767 257653 : m_const_and_copies->record_const_or_copy (def, cached_lhs);
1768 : return;
1769 : }
1770 : else
1771 0 : gcc_unreachable ();
1772 :
1773 56438594 : if (!cached_lhs)
1774 : return;
1775 :
1776 : /* It is safe to ignore types here since we have already done
1777 : type checking in the hashing and equality routines. In fact
1778 : type checking here merely gets in the way of constant
1779 : propagation. Also, make sure that it is safe to propagate
1780 : CACHED_LHS into the expression in STMT. */
1781 954757 : if ((TREE_CODE (cached_lhs) != SSA_NAME
1782 559154 : && (assigns_var_p
1783 33704 : || useless_type_conversion_p (expr_type, TREE_TYPE (cached_lhs))))
1784 954757 : || may_propagate_copy_into_stmt (stmt, cached_lhs))
1785 : {
1786 940007 : gcc_checking_assert (TREE_CODE (cached_lhs) == SSA_NAME
1787 : || is_gimple_min_invariant (cached_lhs));
1788 :
1789 940007 : if (dump_file && (dump_flags & TDF_DETAILS))
1790 : {
1791 19 : fprintf (dump_file, " Replaced redundant expr '");
1792 19 : print_gimple_expr (dump_file, stmt, 0, dump_flags);
1793 19 : fprintf (dump_file, "' with '");
1794 19 : print_generic_expr (dump_file, cached_lhs, dump_flags);
1795 19 : fprintf (dump_file, "'\n");
1796 : }
1797 :
1798 940007 : opt_stats.num_re++;
1799 :
1800 940007 : if (assigns_var_p
1801 940007 : && !useless_type_conversion_p (expr_type, TREE_TYPE (cached_lhs)))
1802 0 : cached_lhs = fold_convert (expr_type, cached_lhs);
1803 :
1804 940007 : propagate_tree_value_into_stmt (gsi, cached_lhs);
1805 :
1806 : /* Since it is always necessary to mark the result as modified,
1807 : perhaps we should move this into propagate_tree_value_into_stmt
1808 : itself. */
1809 940007 : gimple_set_modified (gsi_stmt (*gsi), true);
1810 : }
1811 : }
1812 :
1813 : /* STMT, a GIMPLE_ASSIGN, may create certain equivalences, in either
1814 : the available expressions table or the const_and_copies table.
1815 : Detect and record those equivalences.
1816 :
1817 : We handle only very simple copy equivalences here. The heavy
1818 : lifing is done by eliminate_redundant_computations. */
1819 :
1820 : void
1821 49423572 : dom_opt_dom_walker::record_equivalences_from_stmt (gimple *stmt,
1822 : int may_optimize_p)
1823 : {
1824 49423572 : tree lhs;
1825 49423572 : enum tree_code lhs_code;
1826 :
1827 49423572 : gcc_assert (is_gimple_assign (stmt));
1828 :
1829 49423572 : lhs = gimple_assign_lhs (stmt);
1830 49423572 : lhs_code = TREE_CODE (lhs);
1831 :
1832 49423572 : if (lhs_code == SSA_NAME
1833 49423572 : && gimple_assign_single_p (stmt))
1834 : {
1835 16273541 : tree rhs = gimple_assign_rhs1 (stmt);
1836 :
1837 : /* If the RHS of the assignment is a constant or another variable that
1838 : may be propagated, register it in the CONST_AND_COPIES table. We
1839 : do not need to record unwind data for this, since this is a true
1840 : assignment and not an equivalence inferred from a comparison. All
1841 : uses of this ssa name are dominated by this assignment, so unwinding
1842 : just costs time and space. */
1843 16273541 : if (may_optimize_p
1844 16273541 : && (TREE_CODE (rhs) == SSA_NAME
1845 14178433 : || is_gimple_min_invariant (rhs)))
1846 : {
1847 2113002 : rhs = dom_valueize (rhs);
1848 :
1849 2113002 : if (dump_file && (dump_flags & TDF_DETAILS))
1850 : {
1851 73 : fprintf (dump_file, "==== ASGN ");
1852 73 : print_generic_expr (dump_file, lhs);
1853 73 : fprintf (dump_file, " = ");
1854 73 : print_generic_expr (dump_file, rhs);
1855 73 : fprintf (dump_file, "\n");
1856 : }
1857 :
1858 2113002 : set_ssa_name_value (lhs, rhs);
1859 : }
1860 : }
1861 :
1862 : /* Make sure we can propagate &x + CST. */
1863 49423572 : if (lhs_code == SSA_NAME
1864 33377209 : && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
1865 1685705 : && TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR
1866 49625285 : && TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST)
1867 : {
1868 7310 : tree op0 = gimple_assign_rhs1 (stmt);
1869 7310 : tree op1 = gimple_assign_rhs2 (stmt);
1870 7310 : tree new_rhs
1871 14620 : = build1 (ADDR_EXPR, TREE_TYPE (op0),
1872 7310 : fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (op0)),
1873 : unshare_expr (op0), fold_convert (ptr_type_node,
1874 : op1)));
1875 7310 : if (dump_file && (dump_flags & TDF_DETAILS))
1876 : {
1877 0 : fprintf (dump_file, "==== ASGN ");
1878 0 : print_generic_expr (dump_file, lhs);
1879 0 : fprintf (dump_file, " = ");
1880 0 : print_generic_expr (dump_file, new_rhs);
1881 0 : fprintf (dump_file, "\n");
1882 : }
1883 :
1884 7310 : set_ssa_name_value (lhs, new_rhs);
1885 : }
1886 :
1887 : /* A memory store, even an aliased store, creates a useful
1888 : equivalence. By exchanging the LHS and RHS, creating suitable
1889 : vops and recording the result in the available expression table,
1890 : we may be able to expose more redundant loads. */
1891 95103379 : if (!gimple_has_volatile_ops (stmt)
1892 74258016 : && gimple_references_memory_p (stmt)
1893 24834444 : && gimple_assign_single_p (stmt)
1894 24834444 : && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
1895 19419016 : || is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
1896 61324080 : && !is_gimple_reg (lhs))
1897 : {
1898 11731707 : tree rhs = gimple_assign_rhs1 (stmt);
1899 11731707 : gassign *new_stmt;
1900 :
1901 : /* Build a new statement with the RHS and LHS exchanged. */
1902 11731707 : if (TREE_CODE (rhs) == SSA_NAME)
1903 : {
1904 : /* NOTE tuples. The call to gimple_build_assign below replaced
1905 : a call to build_gimple_modify_stmt, which did not set the
1906 : SSA_NAME_DEF_STMT on the LHS of the assignment. Doing so
1907 : may cause an SSA validation failure, as the LHS may be a
1908 : default-initialized name and should have no definition. I'm
1909 : a bit dubious of this, as the artificial statement that we
1910 : generate here may in fact be ill-formed, but it is simply
1911 : used as an internal device in this pass, and never becomes
1912 : part of the CFG. */
1913 5279300 : gimple *defstmt = SSA_NAME_DEF_STMT (rhs);
1914 5279300 : new_stmt = gimple_build_assign (rhs, lhs);
1915 5279300 : SSA_NAME_DEF_STMT (rhs) = defstmt;
1916 : }
1917 : else
1918 6452407 : new_stmt = gimple_build_assign (rhs, lhs);
1919 :
1920 23463414 : gimple_set_vuse (new_stmt, gimple_vdef (stmt));
1921 :
1922 : /* Finally enter the statement into the available expression
1923 : table. */
1924 11731707 : m_avail_exprs_stack->lookup_avail_expr (new_stmt, true, true);
1925 : }
1926 49423572 : }
1927 :
1928 : /* Replace *OP_P in STMT with any known equivalent value for *OP_P from
1929 : CONST_AND_COPIES. */
1930 :
1931 : static void
1932 83245231 : cprop_operand (gimple *stmt, use_operand_p op_p, range_query *query)
1933 : {
1934 83245231 : tree val;
1935 83245231 : tree op = USE_FROM_PTR (op_p);
1936 :
1937 : /* If the operand has a known constant value or it is known to be a
1938 : copy of some other variable, use the value or copy stored in
1939 : CONST_AND_COPIES. */
1940 83245231 : val = SSA_NAME_VALUE (op);
1941 56568832 : if (!val)
1942 : {
1943 79111570 : value_range r (TREE_TYPE (op));
1944 79111570 : tree single;
1945 155778763 : if (query->range_of_expr (r, op, stmt) && r.singleton_p (&single))
1946 10584 : val = single;
1947 79111570 : }
1948 :
1949 83245231 : if (val && val != op)
1950 : {
1951 : /* Certain operands are not allowed to be copy propagated due
1952 : to their interaction with exception handling and some GCC
1953 : extensions. */
1954 4142410 : if (!may_propagate_copy (op, val))
1955 : return;
1956 :
1957 : /* Do not propagate copies into BIVs.
1958 : See PR23821 and PR62217 for how this can disturb IV and
1959 : number of iteration analysis. */
1960 4140864 : if (TREE_CODE (val) != INTEGER_CST)
1961 : {
1962 3347317 : gimple *def = SSA_NAME_DEF_STMT (op);
1963 3347317 : if (gimple_code (def) == GIMPLE_PHI
1964 3347317 : && gimple_bb (def)->loop_father->header == gimple_bb (def))
1965 : return;
1966 : }
1967 :
1968 : /* Dump details. */
1969 4129453 : if (dump_file && (dump_flags & TDF_DETAILS))
1970 : {
1971 76 : fprintf (dump_file, " Replaced '");
1972 76 : print_generic_expr (dump_file, op, dump_flags);
1973 76 : fprintf (dump_file, "' with %s '",
1974 76 : (TREE_CODE (val) != SSA_NAME ? "constant" : "variable"));
1975 76 : print_generic_expr (dump_file, val, dump_flags);
1976 76 : fprintf (dump_file, "'\n");
1977 : }
1978 :
1979 4129453 : if (TREE_CODE (val) != SSA_NAME)
1980 977050 : opt_stats.num_const_prop++;
1981 : else
1982 3152403 : opt_stats.num_copy_prop++;
1983 :
1984 4129453 : propagate_value (op_p, val);
1985 :
1986 : /* And note that we modified this statement. This is now
1987 : safe, even if we changed virtual operands since we will
1988 : rescan the statement and rewrite its operands again. */
1989 4129453 : gimple_set_modified (stmt, true);
1990 : }
1991 : }
1992 :
1993 : /* Fold the conditional STMT with range info. */
1994 :
1995 : void
1996 55374106 : dom_opt_dom_walker::fold_cond (gimple *stmt)
1997 : {
1998 55374106 : gcond *cond = dyn_cast <gcond *> (stmt);
1999 55374106 : if (!cond)
2000 46101534 : return;
2001 :
2002 9272572 : simplify_using_ranges simplify (m_ranger);
2003 9272572 : if (simplify.fold_cond (cond))
2004 86902 : gimple_set_modified (cond, true);
2005 9272572 : }
2006 :
2007 : /* CONST_AND_COPIES is a table which maps an SSA_NAME to the current
2008 : known value for that SSA_NAME (or NULL if no value is known).
2009 :
2010 : Propagate values from CONST_AND_COPIES into the uses, vuses and
2011 : vdef_ops of STMT. */
2012 :
2013 : static void
2014 186295113 : cprop_into_stmt (gimple *stmt, range_query *query)
2015 : {
2016 186295113 : use_operand_p op_p;
2017 186295113 : ssa_op_iter iter;
2018 186295113 : tree last_copy_propagated_op = NULL;
2019 :
2020 269541025 : FOR_EACH_SSA_USE_OPERAND (op_p, stmt, iter, SSA_OP_USE)
2021 : {
2022 83245912 : tree old_op = USE_FROM_PTR (op_p);
2023 :
2024 : /* If we have A = B and B = A in the copy propagation tables
2025 : (due to an equality comparison), avoid substituting B for A
2026 : then A for B in the trivially discovered cases. This allows
2027 : optimization of statements were A and B appear as input
2028 : operands. */
2029 83245912 : if (old_op != last_copy_propagated_op)
2030 : {
2031 83245231 : cprop_operand (stmt, op_p, query);
2032 :
2033 83245231 : tree new_op = USE_FROM_PTR (op_p);
2034 83245231 : if (new_op != old_op && TREE_CODE (new_op) == SSA_NAME)
2035 83245912 : last_copy_propagated_op = new_op;
2036 : }
2037 : }
2038 186295113 : }
2039 :
2040 : /* If STMT is a comparison of two uniform vectors reduce it to a comparison
2041 : of scalar objects, otherwise leave STMT unchanged. */
2042 :
2043 : static void
2044 186295113 : reduce_vector_comparison_to_scalar_comparison (gimple *stmt)
2045 : {
2046 186295113 : if (gimple_code (stmt) == GIMPLE_COND)
2047 : {
2048 9327798 : tree lhs = gimple_cond_lhs (stmt);
2049 9327798 : tree rhs = gimple_cond_rhs (stmt);
2050 :
2051 : /* We may have a vector comparison where both arms are uniform
2052 : vectors. If so, we can simplify the vector comparison down
2053 : to a scalar comparison. */
2054 9327798 : if (VECTOR_TYPE_P (TREE_TYPE (lhs))
2055 9327798 : && VECTOR_TYPE_P (TREE_TYPE (rhs)))
2056 : {
2057 : /* If either operand is an SSA_NAME, then look back to its
2058 : defining statement to try and get at a suitable source. */
2059 2490 : if (TREE_CODE (rhs) == SSA_NAME)
2060 : {
2061 0 : gimple *def_stmt = SSA_NAME_DEF_STMT (rhs);
2062 0 : if (gimple_assign_single_p (def_stmt))
2063 0 : rhs = gimple_assign_rhs1 (def_stmt);
2064 : }
2065 :
2066 2490 : if (TREE_CODE (lhs) == SSA_NAME)
2067 : {
2068 2490 : gimple *def_stmt = SSA_NAME_DEF_STMT (lhs);
2069 2490 : if (gimple_assign_single_p (def_stmt))
2070 4 : lhs = gimple_assign_rhs1 (def_stmt);
2071 : }
2072 :
2073 : /* Now see if they are both uniform vectors and if so replace
2074 : the vector comparison with a scalar comparison. */
2075 2490 : tree rhs_elem = rhs ? uniform_vector_p (rhs) : NULL_TREE;
2076 2490 : tree lhs_elem = lhs ? uniform_vector_p (lhs) : NULL_TREE;
2077 2490 : if (rhs_elem && lhs_elem)
2078 : {
2079 3 : if (dump_file && dump_flags & TDF_DETAILS)
2080 : {
2081 0 : fprintf (dump_file, "Reducing vector comparison: ");
2082 0 : print_gimple_stmt (dump_file, stmt, 0);
2083 : }
2084 :
2085 3 : gimple_cond_set_rhs (as_a <gcond *>(stmt), rhs_elem);
2086 3 : gimple_cond_set_lhs (as_a <gcond *>(stmt), lhs_elem);
2087 3 : gimple_set_modified (stmt, true);
2088 :
2089 3 : if (dump_file && dump_flags & TDF_DETAILS)
2090 : {
2091 0 : fprintf (dump_file, "To scalar equivalent: ");
2092 0 : print_gimple_stmt (dump_file, stmt, 0);
2093 0 : fprintf (dump_file, "\n");
2094 : }
2095 : }
2096 : }
2097 : }
2098 186295113 : }
2099 :
2100 : /* Optimize the statement in block BB pointed to by iterator SI.
2101 :
2102 : We try to perform some simplistic global redundancy elimination and
2103 : constant propagation:
2104 :
2105 : 1- To detect global redundancy, we keep track of expressions that have
2106 : been computed in this block and its dominators. If we find that the
2107 : same expression is computed more than once, we eliminate repeated
2108 : computations by using the target of the first one.
2109 :
2110 : 2- Constant values and copy assignments. This is used to do very
2111 : simplistic constant and copy propagation. When a constant or copy
2112 : assignment is found, we map the value on the RHS of the assignment to
2113 : the variable in the LHS in the CONST_AND_COPIES table.
2114 :
2115 : 3- Very simple redundant store elimination is performed.
2116 :
2117 : 4- We can simplify a condition to a constant or from a relational
2118 : condition to an equality condition. */
2119 :
2120 : edge
2121 186295113 : dom_opt_dom_walker::optimize_stmt (basic_block bb, gimple_stmt_iterator *si,
2122 : bool *removed_p)
2123 : {
2124 186295113 : gimple *stmt, *old_stmt;
2125 186295113 : bool may_optimize_p;
2126 186295113 : bool modified_p = false;
2127 186295113 : bool was_noreturn;
2128 186295113 : edge retval = NULL;
2129 :
2130 186295113 : old_stmt = stmt = gsi_stmt (*si);
2131 186295113 : was_noreturn = is_gimple_call (stmt) && gimple_call_noreturn_p (stmt);
2132 :
2133 186295113 : if (dump_file && (dump_flags & TDF_DETAILS))
2134 : {
2135 1623 : fprintf (dump_file, "Optimizing statement ");
2136 1623 : print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
2137 : }
2138 :
2139 : /* STMT may be a comparison of uniform vectors that we can simplify
2140 : down to a comparison of scalars. Do that transformation first
2141 : so that all the scalar optimizations from here onward apply. */
2142 186295113 : reduce_vector_comparison_to_scalar_comparison (stmt);
2143 :
2144 186295113 : update_stmt_if_modified (stmt);
2145 186295113 : opt_stats.num_stmts++;
2146 :
2147 : /* Const/copy propagate into USES, VUSES and the RHS of VDEFs. */
2148 186295113 : cprop_into_stmt (stmt, m_ranger);
2149 :
2150 : /* If the statement has been modified with constant replacements,
2151 : fold its RHS before checking for redundant computations. */
2152 372247664 : if (gimple_modified_p (stmt))
2153 : {
2154 3959265 : tree rhs = NULL;
2155 :
2156 : /* Try to fold the statement making sure that STMT is kept
2157 : up to date. */
2158 3959265 : if (fold_stmt (si))
2159 : {
2160 409958 : stmt = gsi_stmt (*si);
2161 409958 : gimple_set_modified (stmt, true);
2162 :
2163 409958 : if (dump_file && (dump_flags & TDF_DETAILS))
2164 : {
2165 10 : fprintf (dump_file, " Folded to: ");
2166 10 : print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
2167 : }
2168 : }
2169 :
2170 : /* We only need to consider cases that can yield a gimple operand. */
2171 3959265 : if (gimple_assign_single_p (stmt))
2172 1463890 : rhs = gimple_assign_rhs1 (stmt);
2173 2495375 : else if (gimple_code (stmt) == GIMPLE_GOTO)
2174 2 : rhs = gimple_goto_dest (stmt);
2175 186297056 : else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt))
2176 : /* This should never be an ADDR_EXPR. */
2177 1943 : rhs = gimple_switch_index (swtch_stmt);
2178 :
2179 1465835 : if (rhs && TREE_CODE (rhs) == ADDR_EXPR)
2180 83019 : recompute_tree_invariant_for_addr_expr (rhs);
2181 :
2182 : /* Indicate that maybe_clean_or_replace_eh_stmt needs to be called,
2183 : even if fold_stmt updated the stmt already and thus cleared
2184 : gimple_modified_p flag on it. */
2185 : modified_p = true;
2186 : }
2187 :
2188 : /* Check for redundant computations. Do this optimization only
2189 : for assignments that have no volatile ops and conditionals. */
2190 186295113 : may_optimize_p = (!gimple_has_side_effects (stmt)
2191 186295113 : && (is_gimple_assign (stmt)
2192 126761478 : || (is_gimple_call (stmt)
2193 1283289 : && gimple_call_lhs (stmt) != NULL_TREE)
2194 125478553 : || gimple_code (stmt) == GIMPLE_COND
2195 116150755 : || gimple_code (stmt) == GIMPLE_SWITCH));
2196 :
2197 : if (may_optimize_p)
2198 : {
2199 56438594 : if (gimple_code (stmt) == GIMPLE_CALL)
2200 : {
2201 : /* Resolve __builtin_constant_p. If it hasn't been
2202 : folded to integer_one_node by now, it's fairly
2203 : certain that the value simply isn't constant. */
2204 1282925 : tree callee = gimple_call_fndecl (stmt);
2205 1282925 : if (callee
2206 1282925 : && fndecl_built_in_p (callee, BUILT_IN_CONSTANT_P))
2207 : {
2208 3994 : propagate_tree_value_into_stmt (si, integer_zero_node);
2209 3994 : stmt = gsi_stmt (*si);
2210 : }
2211 : }
2212 :
2213 56438594 : update_stmt_if_modified (stmt);
2214 56438594 : eliminate_redundant_computations (si);
2215 56438594 : stmt = gsi_stmt (*si);
2216 :
2217 : /* Perform simple redundant store elimination. */
2218 56438594 : if (gimple_assign_single_p (stmt)
2219 28700620 : && TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME
2220 69449914 : && (TREE_CODE (gimple_assign_lhs (stmt)) != VAR_DECL
2221 1052499 : || !DECL_HARD_REGISTER (gimple_assign_lhs (stmt))))
2222 : {
2223 13009300 : tree lhs = gimple_assign_lhs (stmt);
2224 13009300 : tree rhs = gimple_assign_rhs1 (stmt);
2225 13009300 : tree cached_lhs;
2226 13009300 : gassign *new_stmt;
2227 13009300 : rhs = dom_valueize (rhs);
2228 : /* Build a new statement with the RHS and LHS exchanged. */
2229 13009300 : if (TREE_CODE (rhs) == SSA_NAME)
2230 : {
2231 5399901 : gimple *defstmt = SSA_NAME_DEF_STMT (rhs);
2232 5399901 : new_stmt = gimple_build_assign (rhs, lhs);
2233 5399901 : SSA_NAME_DEF_STMT (rhs) = defstmt;
2234 : }
2235 : else
2236 7609399 : new_stmt = gimple_build_assign (rhs, lhs);
2237 26018600 : gimple_set_vuse (new_stmt, gimple_vuse (stmt));
2238 13009300 : expr_hash_elt *elt = NULL;
2239 13009300 : cached_lhs = m_avail_exprs_stack->lookup_avail_expr (new_stmt, false,
2240 : false, &elt);
2241 13009300 : if (cached_lhs
2242 855564 : && operand_equal_p (rhs, cached_lhs, 0)
2243 13267382 : && refs_same_for_tbaa_p (elt->expr ()->kind == EXPR_SINGLE
2244 129041 : ? elt->expr ()->ops.single.rhs
2245 : : NULL_TREE, lhs))
2246 : {
2247 124481 : basic_block bb = gimple_bb (stmt);
2248 124481 : unlink_stmt_vdef (stmt);
2249 124481 : if (gsi_remove (si, true))
2250 : {
2251 0 : bitmap_set_bit (need_eh_cleanup, bb->index);
2252 0 : if (dump_file && (dump_flags & TDF_DETAILS))
2253 0 : fprintf (dump_file, " Flagged to clear EH edges.\n");
2254 : }
2255 124481 : release_defs (stmt);
2256 124481 : *removed_p = true;
2257 124481 : return retval;
2258 : }
2259 : }
2260 :
2261 : /* If this statement was not redundant, we may still be able to simplify
2262 : it, which may in turn allow other part of DOM or other passes to do
2263 : a better job. */
2264 112628226 : if (!gimple_modified_p (stmt))
2265 55374106 : fold_cond (stmt);
2266 : }
2267 :
2268 : /* Record any additional equivalences created by this statement. */
2269 186170632 : if (is_gimple_assign (stmt))
2270 49423572 : record_equivalences_from_stmt (stmt, may_optimize_p);
2271 :
2272 : /* If STMT is a COND_EXPR or SWITCH_EXPR and it was modified, then we may
2273 : know where it goes. */
2274 372341264 : if (gimple_modified_p (stmt) || modified_p)
2275 : {
2276 4582290 : tree val = NULL;
2277 :
2278 4582290 : if (gimple_code (stmt) == GIMPLE_COND)
2279 582926 : val = fold_binary_loc (gimple_location (stmt),
2280 : gimple_cond_code (stmt), boolean_type_node,
2281 : gimple_cond_lhs (stmt),
2282 : gimple_cond_rhs (stmt));
2283 3999364 : else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt))
2284 1943 : val = gimple_switch_index (swtch_stmt);
2285 :
2286 584869 : if (val && TREE_CODE (val) == INTEGER_CST)
2287 : {
2288 188941 : retval = find_taken_edge (bb, val);
2289 188941 : if (retval)
2290 : {
2291 : /* Fix the condition to be either true or false. */
2292 188941 : if (gimple_code (stmt) == GIMPLE_COND)
2293 : {
2294 188926 : if (integer_zerop (val))
2295 126782 : gimple_cond_make_false (as_a <gcond *> (stmt));
2296 62144 : else if (integer_onep (val))
2297 62144 : gimple_cond_make_true (as_a <gcond *> (stmt));
2298 : else
2299 0 : gcc_unreachable ();
2300 :
2301 188926 : gimple_set_modified (stmt, true);
2302 : }
2303 :
2304 : /* Further simplifications may be possible. */
2305 188941 : cfg_altered = true;
2306 : }
2307 : }
2308 :
2309 4582290 : update_stmt_if_modified (stmt);
2310 :
2311 : /* If we simplified a statement in such a way as to be shown that it
2312 : cannot trap, update the eh information and the cfg to match. */
2313 4582290 : if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
2314 : {
2315 1410 : bitmap_set_bit (need_eh_cleanup, bb->index);
2316 1410 : if (dump_file && (dump_flags & TDF_DETAILS))
2317 0 : fprintf (dump_file, " Flagged to clear EH edges.\n");
2318 : }
2319 :
2320 4582290 : if (!was_noreturn
2321 4582290 : && is_gimple_call (stmt) && gimple_call_noreturn_p (stmt))
2322 3 : need_noreturn_fixup.safe_push (stmt);
2323 : }
2324 : return retval;
2325 : }
|
