1 /* Forward propagation of expressions for single use variables.
2 Copyright (C) 2004-2014 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
22 #include "coretypes.h"
25 #include "stor-layout.h"
27 #include "basic-block.h"
28 #include "gimple-pretty-print.h"
29 #include "tree-ssa-alias.h"
30 #include "internal-fn.h"
31 #include "gimple-fold.h"
33 #include "gimple-expr.h"
37 #include "gimple-iterator.h"
38 #include "gimplify-me.h"
39 #include "gimple-ssa.h"
41 #include "tree-phinodes.h"
42 #include "ssa-iterators.h"
43 #include "stringpool.h"
44 #include "tree-ssanames.h"
47 #include "tree-pass.h"
48 #include "langhooks.h"
53 #include "tree-ssa-propagate.h"
54 #include "tree-ssa-dom.h"
56 /* This pass propagates the RHS of assignment statements into use
57 sites of the LHS of the assignment. It's basically a specialized
58 form of tree combination. It is hoped all of this can disappear
59 when we have a generalized tree combiner.
61 One class of common cases we handle is forward propagating a single use
62 variable into a COND_EXPR.
66 if (x) goto ... else goto ...
68 Will be transformed into:
71 if (a COND b) goto ... else goto ...
73 Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1).
75 Or (assuming c1 and c2 are constants):
79 if (x EQ/NEQ c2) goto ... else goto ...
81 Will be transformed into:
84 if (a EQ/NEQ (c2 - c1)) goto ... else goto ...
86 Similarly for x = a - c1.
92 if (x) goto ... else goto ...
94 Will be transformed into:
97 if (a == 0) goto ... else goto ...
99 Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1).
100 For these cases, we propagate A into all, possibly more than one,
101 COND_EXPRs that use X.
107 if (x) goto ... else goto ...
109 Will be transformed into:
112 if (a != 0) goto ... else goto ...
114 (Assuming a is an integral type and x is a boolean or x is an
115 integral and a is a boolean.)
117 Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1).
118 For these cases, we propagate A into all, possibly more than one,
119 COND_EXPRs that use X.
121 In addition to eliminating the variable and the statement which assigns
122 a value to the variable, we may be able to later thread the jump without
123 adding insane complexity in the dominator optimizer.
125 Also note these transformations can cascade. We handle this by having
126 a worklist of COND_EXPR statements to examine. As we make a change to
127 a statement, we put it back on the worklist to examine on the next
128 iteration of the main loop.
130 A second class of propagation opportunities arises for ADDR_EXPR
141 ptr = (type1*)&type2var;
144 Will get turned into (if type1 and type2 are the same size
145 and neither have volatile on them):
146 res = VIEW_CONVERT_EXPR<type1>(type2var)
151 ptr2 = ptr + <constant>;
155 ptr2 = &x[constant/elementsize];
160 offset = index * element_size;
161 offset_p = (pointer) offset;
162 ptr2 = ptr + offset_p
164 Will get turned into:
172 Provided that decl has known alignment >= 2, will get turned into
176 We also propagate casts into SWITCH_EXPR and COND_EXPR conditions to
177 allow us to remove the cast and {NOT_EXPR,NEG_EXPR} into a subsequent
180 This will (of course) be extended as other needs arise. */
182 static bool forward_propagate_addr_expr (tree, tree, bool);
184 /* Set to true if we delete dead edges during the optimization. */
185 static bool cfg_changed;
187 static tree rhs_to_tree (tree type, gimple stmt);
189 /* Get the next statement we can propagate NAME's value into skipping
190 trivial copies. Returns the statement that is suitable as a
191 propagation destination or NULL_TREE if there is no such one.
192 This only returns destinations in a single-use chain. FINAL_NAME_P
193 if non-NULL is written to the ssa name that represents the use. */
196 get_prop_dest_stmt (tree name, tree *final_name_p)
202 /* If name has multiple uses, bail out. */
203 if (!single_imm_use (name, &use, &use_stmt))
206 /* If this is not a trivial copy, we found it. */
207 if (!gimple_assign_ssa_name_copy_p (use_stmt)
208 || gimple_assign_rhs1 (use_stmt) != name)
211 /* Continue searching uses of the copy destination. */
212 name = gimple_assign_lhs (use_stmt);
216 *final_name_p = name;
221 /* Get the statement we can propagate from into NAME skipping
222 trivial copies. Returns the statement which defines the
223 propagation source or NULL_TREE if there is no such one.
224 If SINGLE_USE_ONLY is set considers only sources which have
225 a single use chain up to NAME. If SINGLE_USE_P is non-null,
226 it is set to whether the chain to NAME is a single use chain
227 or not. SINGLE_USE_P is not written to if SINGLE_USE_ONLY is set. */
230 get_prop_source_stmt (tree name, bool single_use_only, bool *single_use_p)
232 bool single_use = true;
235 gimple def_stmt = SSA_NAME_DEF_STMT (name);
237 if (!has_single_use (name))
244 /* If name is defined by a PHI node or is the default def, bail out. */
245 if (!is_gimple_assign (def_stmt))
248 /* If def_stmt is a simple copy, continue looking. */
249 if (gimple_assign_rhs_code (def_stmt) == SSA_NAME)
250 name = gimple_assign_rhs1 (def_stmt);
253 if (!single_use_only && single_use_p)
254 *single_use_p = single_use;
261 /* Checks if the destination ssa name in DEF_STMT can be used as
262 propagation source. Returns true if so, otherwise false. */
265 can_propagate_from (gimple def_stmt)
267 gcc_assert (is_gimple_assign (def_stmt));
269 /* If the rhs has side-effects we cannot propagate from it. */
270 if (gimple_has_volatile_ops (def_stmt))
273 /* If the rhs is a load we cannot propagate from it. */
274 if (TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_reference
275 || TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_declaration)
278 /* Constants can be always propagated. */
279 if (gimple_assign_single_p (def_stmt)
280 && is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt)))
283 /* We cannot propagate ssa names that occur in abnormal phi nodes. */
284 if (stmt_references_abnormal_ssa_name (def_stmt))
287 /* If the definition is a conversion of a pointer to a function type,
288 then we can not apply optimizations as some targets require
289 function pointers to be canonicalized and in this case this
290 optimization could eliminate a necessary canonicalization. */
291 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
293 tree rhs = gimple_assign_rhs1 (def_stmt);
294 if (POINTER_TYPE_P (TREE_TYPE (rhs))
295 && TREE_CODE (TREE_TYPE (TREE_TYPE (rhs))) == FUNCTION_TYPE)
302 /* Remove a chain of dead statements starting at the definition of
303 NAME. The chain is linked via the first operand of the defining statements.
304 If NAME was replaced in its only use then this function can be used
305 to clean up dead stmts. The function handles already released SSA
307 Returns true if cleanup-cfg has to run. */
310 remove_prop_source_from_use (tree name)
312 gimple_stmt_iterator gsi;
314 bool cfg_changed = false;
319 if (SSA_NAME_IN_FREE_LIST (name)
320 || SSA_NAME_IS_DEFAULT_DEF (name)
321 || !has_zero_uses (name))
324 stmt = SSA_NAME_DEF_STMT (name);
325 if (gimple_code (stmt) == GIMPLE_PHI
326 || gimple_has_side_effects (stmt))
329 bb = gimple_bb (stmt);
330 gsi = gsi_for_stmt (stmt);
331 unlink_stmt_vdef (stmt);
332 if (gsi_remove (&gsi, true))
333 cfg_changed |= gimple_purge_dead_eh_edges (bb);
336 name = is_gimple_assign (stmt) ? gimple_assign_rhs1 (stmt) : NULL_TREE;
337 } while (name && TREE_CODE (name) == SSA_NAME);
342 /* Return the rhs of a gimple_assign STMT in a form of a single tree,
343 converted to type TYPE.
345 This should disappear, but is needed so we can combine expressions and use
346 the fold() interfaces. Long term, we need to develop folding and combine
347 routines that deal with gimple exclusively . */
350 rhs_to_tree (tree type, gimple stmt)
352 location_t loc = gimple_location (stmt);
353 enum tree_code code = gimple_assign_rhs_code (stmt);
354 if (get_gimple_rhs_class (code) == GIMPLE_TERNARY_RHS)
355 return fold_build3_loc (loc, code, type, gimple_assign_rhs1 (stmt),
356 gimple_assign_rhs2 (stmt),
357 gimple_assign_rhs3 (stmt));
358 else if (get_gimple_rhs_class (code) == GIMPLE_BINARY_RHS)
359 return fold_build2_loc (loc, code, type, gimple_assign_rhs1 (stmt),
360 gimple_assign_rhs2 (stmt));
361 else if (get_gimple_rhs_class (code) == GIMPLE_UNARY_RHS)
362 return build1 (code, type, gimple_assign_rhs1 (stmt));
363 else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
364 return gimple_assign_rhs1 (stmt);
369 /* Combine OP0 CODE OP1 in the context of a COND_EXPR. Returns
370 the folded result in a form suitable for COND_EXPR_COND or
371 NULL_TREE, if there is no suitable simplified form. If
372 INVARIANT_ONLY is true only gimple_min_invariant results are
373 considered simplified. */
376 combine_cond_expr_cond (gimple stmt, enum tree_code code, tree type,
377 tree op0, tree op1, bool invariant_only)
381 gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison);
383 fold_defer_overflow_warnings ();
384 t = fold_binary_loc (gimple_location (stmt), code, type, op0, op1);
387 fold_undefer_overflow_warnings (false, NULL, 0);
391 /* Require that we got a boolean type out if we put one in. */
392 gcc_assert (TREE_CODE (TREE_TYPE (t)) == TREE_CODE (type));
394 /* Canonicalize the combined condition for use in a COND_EXPR. */
395 t = canonicalize_cond_expr_cond (t);
397 /* Bail out if we required an invariant but didn't get one. */
398 if (!t || (invariant_only && !is_gimple_min_invariant (t)))
400 fold_undefer_overflow_warnings (false, NULL, 0);
404 fold_undefer_overflow_warnings (!gimple_no_warning_p (stmt), stmt, 0);
409 /* Combine the comparison OP0 CODE OP1 at LOC with the defining statements
410 of its operand. Return a new comparison tree or NULL_TREE if there
411 were no simplifying combines. */
414 forward_propagate_into_comparison_1 (gimple stmt,
415 enum tree_code code, tree type,
418 tree tmp = NULL_TREE;
419 tree rhs0 = NULL_TREE, rhs1 = NULL_TREE;
420 bool single_use0_p = false, single_use1_p = false;
422 /* For comparisons use the first operand, that is likely to
423 simplify comparisons against constants. */
424 if (TREE_CODE (op0) == SSA_NAME)
426 gimple def_stmt = get_prop_source_stmt (op0, false, &single_use0_p);
427 if (def_stmt && can_propagate_from (def_stmt))
429 rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt);
430 tmp = combine_cond_expr_cond (stmt, code, type,
431 rhs0, op1, !single_use0_p);
437 /* If that wasn't successful, try the second operand. */
438 if (TREE_CODE (op1) == SSA_NAME)
440 gimple def_stmt = get_prop_source_stmt (op1, false, &single_use1_p);
441 if (def_stmt && can_propagate_from (def_stmt))
443 rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt);
444 tmp = combine_cond_expr_cond (stmt, code, type,
445 op0, rhs1, !single_use1_p);
451 /* If that wasn't successful either, try both operands. */
452 if (rhs0 != NULL_TREE
453 && rhs1 != NULL_TREE)
454 tmp = combine_cond_expr_cond (stmt, code, type,
456 !(single_use0_p && single_use1_p));
461 /* Propagate from the ssa name definition statements of the assignment
462 from a comparison at *GSI into the conditional if that simplifies it.
463 Returns 1 if the stmt was modified and 2 if the CFG needs cleanup,
464 otherwise returns 0. */
467 forward_propagate_into_comparison (gimple_stmt_iterator *gsi)
469 gimple stmt = gsi_stmt (*gsi);
471 bool cfg_changed = false;
472 tree type = TREE_TYPE (gimple_assign_lhs (stmt));
473 tree rhs1 = gimple_assign_rhs1 (stmt);
474 tree rhs2 = gimple_assign_rhs2 (stmt);
476 /* Combine the comparison with defining statements. */
477 tmp = forward_propagate_into_comparison_1 (stmt,
478 gimple_assign_rhs_code (stmt),
480 if (tmp && useless_type_conversion_p (type, TREE_TYPE (tmp)))
482 gimple_assign_set_rhs_from_tree (gsi, tmp);
484 update_stmt (gsi_stmt (*gsi));
486 if (TREE_CODE (rhs1) == SSA_NAME)
487 cfg_changed |= remove_prop_source_from_use (rhs1);
488 if (TREE_CODE (rhs2) == SSA_NAME)
489 cfg_changed |= remove_prop_source_from_use (rhs2);
490 return cfg_changed ? 2 : 1;
496 /* Propagate from the ssa name definition statements of COND_EXPR
497 in GIMPLE_COND statement STMT into the conditional if that simplifies it.
498 Returns zero if no statement was changed, one if there were
499 changes and two if cfg_cleanup needs to run.
501 This must be kept in sync with forward_propagate_into_cond. */
504 forward_propagate_into_gimple_cond (gimple stmt)
507 enum tree_code code = gimple_cond_code (stmt);
508 bool cfg_changed = false;
509 tree rhs1 = gimple_cond_lhs (stmt);
510 tree rhs2 = gimple_cond_rhs (stmt);
512 /* We can do tree combining on SSA_NAME and comparison expressions. */
513 if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison)
516 tmp = forward_propagate_into_comparison_1 (stmt, code,
521 if (dump_file && tmp)
523 fprintf (dump_file, " Replaced '");
524 print_gimple_expr (dump_file, stmt, 0, 0);
525 fprintf (dump_file, "' with '");
526 print_generic_expr (dump_file, tmp, 0);
527 fprintf (dump_file, "'\n");
530 gimple_cond_set_condition_from_tree (stmt, unshare_expr (tmp));
533 if (TREE_CODE (rhs1) == SSA_NAME)
534 cfg_changed |= remove_prop_source_from_use (rhs1);
535 if (TREE_CODE (rhs2) == SSA_NAME)
536 cfg_changed |= remove_prop_source_from_use (rhs2);
537 return (cfg_changed || is_gimple_min_invariant (tmp)) ? 2 : 1;
540 /* Canonicalize _Bool == 0 and _Bool != 1 to _Bool != 0 by swapping edges. */
541 if ((TREE_CODE (TREE_TYPE (rhs1)) == BOOLEAN_TYPE
542 || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
543 && TYPE_PRECISION (TREE_TYPE (rhs1)) == 1))
545 && integer_zerop (rhs2))
547 && integer_onep (rhs2))))
549 basic_block bb = gimple_bb (stmt);
550 gimple_cond_set_code (stmt, NE_EXPR);
551 gimple_cond_set_rhs (stmt, build_zero_cst (TREE_TYPE (rhs1)));
552 EDGE_SUCC (bb, 0)->flags ^= (EDGE_TRUE_VALUE|EDGE_FALSE_VALUE);
553 EDGE_SUCC (bb, 1)->flags ^= (EDGE_TRUE_VALUE|EDGE_FALSE_VALUE);
561 /* Propagate from the ssa name definition statements of COND_EXPR
562 in the rhs of statement STMT into the conditional if that simplifies it.
563 Returns true zero if the stmt was changed. */
566 forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
568 gimple stmt = gsi_stmt (*gsi_p);
569 tree tmp = NULL_TREE;
570 tree cond = gimple_assign_rhs1 (stmt);
571 enum tree_code code = gimple_assign_rhs_code (stmt);
574 /* We can do tree combining on SSA_NAME and comparison expressions. */
575 if (COMPARISON_CLASS_P (cond))
576 tmp = forward_propagate_into_comparison_1 (stmt, TREE_CODE (cond),
578 TREE_OPERAND (cond, 0),
579 TREE_OPERAND (cond, 1));
580 else if (TREE_CODE (cond) == SSA_NAME)
582 enum tree_code def_code;
584 gimple def_stmt = get_prop_source_stmt (name, true, NULL);
585 if (!def_stmt || !can_propagate_from (def_stmt))
588 def_code = gimple_assign_rhs_code (def_stmt);
589 if (TREE_CODE_CLASS (def_code) == tcc_comparison)
590 tmp = fold_build2_loc (gimple_location (def_stmt),
593 gimple_assign_rhs1 (def_stmt),
594 gimple_assign_rhs2 (def_stmt));
595 else if (code == COND_EXPR
596 && ((def_code == BIT_NOT_EXPR
597 && TYPE_PRECISION (TREE_TYPE (cond)) == 1)
598 || (def_code == BIT_XOR_EXPR
599 && integer_onep (gimple_assign_rhs2 (def_stmt)))))
601 tmp = gimple_assign_rhs1 (def_stmt);
607 && is_gimple_condexpr (tmp))
609 if (dump_file && tmp)
611 fprintf (dump_file, " Replaced '");
612 print_generic_expr (dump_file, cond, 0);
613 fprintf (dump_file, "' with '");
614 print_generic_expr (dump_file, tmp, 0);
615 fprintf (dump_file, "'\n");
618 if ((code == VEC_COND_EXPR) ? integer_all_onesp (tmp)
619 : integer_onep (tmp))
620 gimple_assign_set_rhs_from_tree (gsi_p, gimple_assign_rhs2 (stmt));
621 else if (integer_zerop (tmp))
622 gimple_assign_set_rhs_from_tree (gsi_p, gimple_assign_rhs3 (stmt));
625 gimple_assign_set_rhs1 (stmt, unshare_expr (tmp));
628 tree t = gimple_assign_rhs2 (stmt);
629 gimple_assign_set_rhs2 (stmt, gimple_assign_rhs3 (stmt));
630 gimple_assign_set_rhs3 (stmt, t);
633 stmt = gsi_stmt (*gsi_p);
642 /* Propagate from the ssa name definition statements of COND_EXPR
643 values in the rhs of statement STMT into the conditional arms
644 if that simplifies it.
645 Returns true if the stmt was changed. */
648 combine_cond_exprs (gimple_stmt_iterator *gsi_p)
650 gimple stmt = gsi_stmt (*gsi_p);
651 tree cond, val1, val2;
652 bool changed = false;
654 cond = gimple_assign_rhs1 (stmt);
655 val1 = gimple_assign_rhs2 (stmt);
656 if (TREE_CODE (val1) == SSA_NAME)
658 gimple def_stmt = SSA_NAME_DEF_STMT (val1);
659 if (is_gimple_assign (def_stmt)
660 && gimple_assign_rhs_code (def_stmt) == gimple_assign_rhs_code (stmt)
661 && operand_equal_p (gimple_assign_rhs1 (def_stmt), cond, 0))
663 val1 = unshare_expr (gimple_assign_rhs2 (def_stmt));
664 gimple_assign_set_rhs2 (stmt, val1);
668 val2 = gimple_assign_rhs3 (stmt);
669 if (TREE_CODE (val2) == SSA_NAME)
671 gimple def_stmt = SSA_NAME_DEF_STMT (val2);
672 if (is_gimple_assign (def_stmt)
673 && gimple_assign_rhs_code (def_stmt) == gimple_assign_rhs_code (stmt)
674 && operand_equal_p (gimple_assign_rhs1 (def_stmt), cond, 0))
676 val2 = unshare_expr (gimple_assign_rhs3 (def_stmt));
677 gimple_assign_set_rhs3 (stmt, val2);
681 if (operand_equal_p (val1, val2, 0))
683 gimple_assign_set_rhs_from_tree (gsi_p, val1);
684 stmt = gsi_stmt (*gsi_p);
694 /* We've just substituted an ADDR_EXPR into stmt. Update all the
695 relevant data structures to match. */
698 tidy_after_forward_propagate_addr (gimple stmt)
700 /* We may have turned a trapping insn into a non-trapping insn. */
701 if (maybe_clean_or_replace_eh_stmt (stmt, stmt)
702 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
705 if (TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR)
706 recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt));
709 /* NAME is a SSA_NAME representing DEF_RHS which is of the form
710 ADDR_EXPR <whatever>.
712 Try to forward propagate the ADDR_EXPR into the use USE_STMT.
713 Often this will allow for removal of an ADDR_EXPR and INDIRECT_REF
714 node or for recovery of array indexing from pointer arithmetic.
716 Return true if the propagation was successful (the propagation can
717 be not totally successful, yet things may have been changed). */
720 forward_propagate_addr_expr_1 (tree name, tree def_rhs,
721 gimple_stmt_iterator *use_stmt_gsi,
724 tree lhs, rhs, rhs2, array_ref;
725 gimple use_stmt = gsi_stmt (*use_stmt_gsi);
726 enum tree_code rhs_code;
729 gcc_assert (TREE_CODE (def_rhs) == ADDR_EXPR);
731 lhs = gimple_assign_lhs (use_stmt);
732 rhs_code = gimple_assign_rhs_code (use_stmt);
733 rhs = gimple_assign_rhs1 (use_stmt);
735 /* Do not perform copy-propagation but recurse through copy chains. */
736 if (TREE_CODE (lhs) == SSA_NAME
737 && rhs_code == SSA_NAME)
738 return forward_propagate_addr_expr (lhs, def_rhs, single_use_p);
740 /* The use statement could be a conversion. Recurse to the uses of the
741 lhs as copyprop does not copy through pointer to integer to pointer
742 conversions and FRE does not catch all cases either.
743 Treat the case of a single-use name and
744 a conversion to def_rhs type separate, though. */
745 if (TREE_CODE (lhs) == SSA_NAME
746 && CONVERT_EXPR_CODE_P (rhs_code))
748 /* If there is a point in a conversion chain where the types match
749 so we can remove a conversion re-materialize the address here
752 && useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs)))
754 gimple_assign_set_rhs1 (use_stmt, unshare_expr (def_rhs));
755 gimple_assign_set_rhs_code (use_stmt, TREE_CODE (def_rhs));
759 /* Else recurse if the conversion preserves the address value. */
760 if ((INTEGRAL_TYPE_P (TREE_TYPE (lhs))
761 || POINTER_TYPE_P (TREE_TYPE (lhs)))
762 && (TYPE_PRECISION (TREE_TYPE (lhs))
763 >= TYPE_PRECISION (TREE_TYPE (def_rhs))))
764 return forward_propagate_addr_expr (lhs, def_rhs, single_use_p);
769 /* If this isn't a conversion chain from this on we only can propagate
770 into compatible pointer contexts. */
771 if (!types_compatible_p (TREE_TYPE (name), TREE_TYPE (def_rhs)))
774 /* Propagate through constant pointer adjustments. */
775 if (TREE_CODE (lhs) == SSA_NAME
776 && rhs_code == POINTER_PLUS_EXPR
778 && TREE_CODE (gimple_assign_rhs2 (use_stmt)) == INTEGER_CST)
781 /* As we come here with non-invariant addresses in def_rhs we need
782 to make sure we can build a valid constant offsetted address
783 for further propagation. Simply rely on fold building that
784 and check after the fact. */
785 new_def_rhs = fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (rhs)),
787 fold_convert (ptr_type_node,
788 gimple_assign_rhs2 (use_stmt)));
789 if (TREE_CODE (new_def_rhs) == MEM_REF
790 && !is_gimple_mem_ref_addr (TREE_OPERAND (new_def_rhs, 0)))
792 new_def_rhs = build_fold_addr_expr_with_type (new_def_rhs,
795 /* Recurse. If we could propagate into all uses of lhs do not
796 bother to replace into the current use but just pretend we did. */
797 if (TREE_CODE (new_def_rhs) == ADDR_EXPR
798 && forward_propagate_addr_expr (lhs, new_def_rhs, single_use_p))
801 if (useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (new_def_rhs)))
802 gimple_assign_set_rhs_with_ops (use_stmt_gsi, TREE_CODE (new_def_rhs),
803 new_def_rhs, NULL_TREE);
804 else if (is_gimple_min_invariant (new_def_rhs))
805 gimple_assign_set_rhs_with_ops (use_stmt_gsi, NOP_EXPR,
806 new_def_rhs, NULL_TREE);
809 gcc_assert (gsi_stmt (*use_stmt_gsi) == use_stmt);
810 update_stmt (use_stmt);
814 /* Now strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS.
815 ADDR_EXPR will not appear on the LHS. */
816 tree *lhsp = gimple_assign_lhs_ptr (use_stmt);
817 while (handled_component_p (*lhsp))
818 lhsp = &TREE_OPERAND (*lhsp, 0);
821 /* Now see if the LHS node is a MEM_REF using NAME. If so,
822 propagate the ADDR_EXPR into the use of NAME and fold the result. */
823 if (TREE_CODE (lhs) == MEM_REF
824 && TREE_OPERAND (lhs, 0) == name)
827 HOST_WIDE_INT def_rhs_offset;
828 /* If the address is invariant we can always fold it. */
829 if ((def_rhs_base = get_addr_base_and_unit_offset (TREE_OPERAND (def_rhs, 0),
832 double_int off = mem_ref_offset (lhs);
834 off += double_int::from_shwi (def_rhs_offset);
835 if (TREE_CODE (def_rhs_base) == MEM_REF)
837 off += mem_ref_offset (def_rhs_base);
838 new_ptr = TREE_OPERAND (def_rhs_base, 0);
841 new_ptr = build_fold_addr_expr (def_rhs_base);
842 TREE_OPERAND (lhs, 0) = new_ptr;
843 TREE_OPERAND (lhs, 1)
844 = double_int_to_tree (TREE_TYPE (TREE_OPERAND (lhs, 1)), off);
845 tidy_after_forward_propagate_addr (use_stmt);
846 /* Continue propagating into the RHS if this was not the only use. */
850 /* If the LHS is a plain dereference and the value type is the same as
851 that of the pointed-to type of the address we can put the
852 dereferenced address on the LHS preserving the original alias-type. */
853 else if (integer_zerop (TREE_OPERAND (lhs, 1))
854 && ((gimple_assign_lhs (use_stmt) == lhs
855 && useless_type_conversion_p
856 (TREE_TYPE (TREE_OPERAND (def_rhs, 0)),
857 TREE_TYPE (gimple_assign_rhs1 (use_stmt))))
858 || types_compatible_p (TREE_TYPE (lhs),
859 TREE_TYPE (TREE_OPERAND (def_rhs, 0))))
860 /* Don't forward anything into clobber stmts if it would result
861 in the lhs no longer being a MEM_REF. */
862 && (!gimple_clobber_p (use_stmt)
863 || TREE_CODE (TREE_OPERAND (def_rhs, 0)) == MEM_REF))
865 tree *def_rhs_basep = &TREE_OPERAND (def_rhs, 0);
866 tree new_offset, new_base, saved, new_lhs;
867 while (handled_component_p (*def_rhs_basep))
868 def_rhs_basep = &TREE_OPERAND (*def_rhs_basep, 0);
869 saved = *def_rhs_basep;
870 if (TREE_CODE (*def_rhs_basep) == MEM_REF)
872 new_base = TREE_OPERAND (*def_rhs_basep, 0);
873 new_offset = fold_convert (TREE_TYPE (TREE_OPERAND (lhs, 1)),
874 TREE_OPERAND (*def_rhs_basep, 1));
878 new_base = build_fold_addr_expr (*def_rhs_basep);
879 new_offset = TREE_OPERAND (lhs, 1);
881 *def_rhs_basep = build2 (MEM_REF, TREE_TYPE (*def_rhs_basep),
882 new_base, new_offset);
883 TREE_THIS_VOLATILE (*def_rhs_basep) = TREE_THIS_VOLATILE (lhs);
884 TREE_SIDE_EFFECTS (*def_rhs_basep) = TREE_SIDE_EFFECTS (lhs);
885 TREE_THIS_NOTRAP (*def_rhs_basep) = TREE_THIS_NOTRAP (lhs);
886 new_lhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
888 TREE_THIS_VOLATILE (new_lhs) = TREE_THIS_VOLATILE (lhs);
889 TREE_SIDE_EFFECTS (new_lhs) = TREE_SIDE_EFFECTS (lhs);
890 *def_rhs_basep = saved;
891 tidy_after_forward_propagate_addr (use_stmt);
892 /* Continue propagating into the RHS if this was not the
898 /* We can have a struct assignment dereferencing our name twice.
899 Note that we didn't propagate into the lhs to not falsely
900 claim we did when propagating into the rhs. */
904 /* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR
905 nodes from the RHS. */
906 tree *rhsp = gimple_assign_rhs1_ptr (use_stmt);
907 if (TREE_CODE (*rhsp) == ADDR_EXPR)
908 rhsp = &TREE_OPERAND (*rhsp, 0);
909 while (handled_component_p (*rhsp))
910 rhsp = &TREE_OPERAND (*rhsp, 0);
913 /* Now see if the RHS node is a MEM_REF using NAME. If so,
914 propagate the ADDR_EXPR into the use of NAME and fold the result. */
915 if (TREE_CODE (rhs) == MEM_REF
916 && TREE_OPERAND (rhs, 0) == name)
919 HOST_WIDE_INT def_rhs_offset;
920 if ((def_rhs_base = get_addr_base_and_unit_offset (TREE_OPERAND (def_rhs, 0),
923 double_int off = mem_ref_offset (rhs);
925 off += double_int::from_shwi (def_rhs_offset);
926 if (TREE_CODE (def_rhs_base) == MEM_REF)
928 off += mem_ref_offset (def_rhs_base);
929 new_ptr = TREE_OPERAND (def_rhs_base, 0);
932 new_ptr = build_fold_addr_expr (def_rhs_base);
933 TREE_OPERAND (rhs, 0) = new_ptr;
934 TREE_OPERAND (rhs, 1)
935 = double_int_to_tree (TREE_TYPE (TREE_OPERAND (rhs, 1)), off);
936 fold_stmt_inplace (use_stmt_gsi);
937 tidy_after_forward_propagate_addr (use_stmt);
940 /* If the RHS is a plain dereference and the value type is the same as
941 that of the pointed-to type of the address we can put the
942 dereferenced address on the RHS preserving the original alias-type. */
943 else if (integer_zerop (TREE_OPERAND (rhs, 1))
944 && ((gimple_assign_rhs1 (use_stmt) == rhs
945 && useless_type_conversion_p
946 (TREE_TYPE (gimple_assign_lhs (use_stmt)),
947 TREE_TYPE (TREE_OPERAND (def_rhs, 0))))
948 || types_compatible_p (TREE_TYPE (rhs),
949 TREE_TYPE (TREE_OPERAND (def_rhs, 0)))))
951 tree *def_rhs_basep = &TREE_OPERAND (def_rhs, 0);
952 tree new_offset, new_base, saved, new_rhs;
953 while (handled_component_p (*def_rhs_basep))
954 def_rhs_basep = &TREE_OPERAND (*def_rhs_basep, 0);
955 saved = *def_rhs_basep;
956 if (TREE_CODE (*def_rhs_basep) == MEM_REF)
958 new_base = TREE_OPERAND (*def_rhs_basep, 0);
959 new_offset = fold_convert (TREE_TYPE (TREE_OPERAND (rhs, 1)),
960 TREE_OPERAND (*def_rhs_basep, 1));
964 new_base = build_fold_addr_expr (*def_rhs_basep);
965 new_offset = TREE_OPERAND (rhs, 1);
967 *def_rhs_basep = build2 (MEM_REF, TREE_TYPE (*def_rhs_basep),
968 new_base, new_offset);
969 TREE_THIS_VOLATILE (*def_rhs_basep) = TREE_THIS_VOLATILE (rhs);
970 TREE_SIDE_EFFECTS (*def_rhs_basep) = TREE_SIDE_EFFECTS (rhs);
971 TREE_THIS_NOTRAP (*def_rhs_basep) = TREE_THIS_NOTRAP (rhs);
972 new_rhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
974 TREE_THIS_VOLATILE (new_rhs) = TREE_THIS_VOLATILE (rhs);
975 TREE_SIDE_EFFECTS (new_rhs) = TREE_SIDE_EFFECTS (rhs);
976 *def_rhs_basep = saved;
977 fold_stmt_inplace (use_stmt_gsi);
978 tidy_after_forward_propagate_addr (use_stmt);
983 /* If the use of the ADDR_EXPR is not a POINTER_PLUS_EXPR, there
985 if (gimple_assign_rhs_code (use_stmt) != POINTER_PLUS_EXPR
986 || gimple_assign_rhs1 (use_stmt) != name)
989 /* The remaining cases are all for turning pointer arithmetic into
990 array indexing. They only apply when we have the address of
991 element zero in an array. If that is not the case then there
993 array_ref = TREE_OPERAND (def_rhs, 0);
994 if ((TREE_CODE (array_ref) != ARRAY_REF
995 || TREE_CODE (TREE_TYPE (TREE_OPERAND (array_ref, 0))) != ARRAY_TYPE
996 || TREE_CODE (TREE_OPERAND (array_ref, 1)) != INTEGER_CST)
997 && TREE_CODE (TREE_TYPE (array_ref)) != ARRAY_TYPE)
1000 rhs2 = gimple_assign_rhs2 (use_stmt);
1001 /* Optimize &x[C1] p+ C2 to &x p+ C3 with C3 = C1 * element_size + C2. */
1002 if (TREE_CODE (rhs2) == INTEGER_CST)
1004 tree new_rhs = build1_loc (gimple_location (use_stmt),
1005 ADDR_EXPR, TREE_TYPE (def_rhs),
1006 fold_build2 (MEM_REF,
1007 TREE_TYPE (TREE_TYPE (def_rhs)),
1008 unshare_expr (def_rhs),
1009 fold_convert (ptr_type_node,
1011 gimple_assign_set_rhs_from_tree (use_stmt_gsi, new_rhs);
1012 use_stmt = gsi_stmt (*use_stmt_gsi);
1013 update_stmt (use_stmt);
1014 tidy_after_forward_propagate_addr (use_stmt);
1021 /* STMT is a statement of the form SSA_NAME = ADDR_EXPR <whatever>.
1023 Try to forward propagate the ADDR_EXPR into all uses of the SSA_NAME.
1024 Often this will allow for removal of an ADDR_EXPR and INDIRECT_REF
1025 node or for recovery of array indexing from pointer arithmetic.
1027 PARENT_SINGLE_USE_P tells if, when in a recursive invocation, NAME was
1028 the single use in the previous invocation. Pass true when calling
1031 Returns true, if all uses have been propagated into. */
1034 forward_propagate_addr_expr (tree name, tree rhs, bool parent_single_use_p)
1036 imm_use_iterator iter;
1039 bool single_use_p = parent_single_use_p && has_single_use (name);
1041 FOR_EACH_IMM_USE_STMT (use_stmt, iter, name)
1046 /* If the use is not in a simple assignment statement, then
1047 there is nothing we can do. */
1048 if (!is_gimple_assign (use_stmt))
1050 if (!is_gimple_debug (use_stmt))
1055 gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
1056 result = forward_propagate_addr_expr_1 (name, rhs, &gsi,
1058 /* If the use has moved to a different statement adjust
1059 the update machinery for the old statement too. */
1060 if (use_stmt != gsi_stmt (gsi))
1062 update_stmt (use_stmt);
1063 use_stmt = gsi_stmt (gsi);
1065 update_stmt (use_stmt);
1068 /* Remove intermediate now unused copy and conversion chains. */
1069 use_rhs = gimple_assign_rhs1 (use_stmt);
1071 && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME
1072 && TREE_CODE (use_rhs) == SSA_NAME
1073 && has_zero_uses (gimple_assign_lhs (use_stmt)))
1075 gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
1076 release_defs (use_stmt);
1077 gsi_remove (&gsi, true);
1081 return all && has_zero_uses (name);
1085 /* Forward propagate the comparison defined in *DEFGSI like
1086 cond_1 = x CMP y to uses of the form
1090 Returns true if stmt is now unused. Advance DEFGSI to the next
1094 forward_propagate_comparison (gimple_stmt_iterator *defgsi)
1096 gimple stmt = gsi_stmt (*defgsi);
1097 tree name = gimple_assign_lhs (stmt);
1099 tree tmp = NULL_TREE;
1100 gimple_stmt_iterator gsi;
1101 enum tree_code code;
1104 /* Don't propagate ssa names that occur in abnormal phis. */
1105 if ((TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
1106 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs1 (stmt)))
1107 || (TREE_CODE (gimple_assign_rhs2 (stmt)) == SSA_NAME
1108 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs2 (stmt))))
1111 /* Do not un-cse comparisons. But propagate through copies. */
1112 use_stmt = get_prop_dest_stmt (name, &name);
1114 || !is_gimple_assign (use_stmt))
1117 code = gimple_assign_rhs_code (use_stmt);
1118 lhs = gimple_assign_lhs (use_stmt);
1119 if (!INTEGRAL_TYPE_P (TREE_TYPE (lhs)))
1122 /* We can propagate the condition into a statement that
1123 computes the logical negation of the comparison result. */
1124 if ((code == BIT_NOT_EXPR
1125 && TYPE_PRECISION (TREE_TYPE (lhs)) == 1)
1126 || (code == BIT_XOR_EXPR
1127 && integer_onep (gimple_assign_rhs2 (use_stmt))))
1129 tree type = TREE_TYPE (gimple_assign_rhs1 (stmt));
1130 bool nans = HONOR_NANS (TYPE_MODE (type));
1131 enum tree_code inv_code;
1132 inv_code = invert_tree_comparison (gimple_assign_rhs_code (stmt), nans);
1133 if (inv_code == ERROR_MARK)
1136 tmp = build2 (inv_code, TREE_TYPE (lhs), gimple_assign_rhs1 (stmt),
1137 gimple_assign_rhs2 (stmt));
1142 gsi = gsi_for_stmt (use_stmt);
1143 gimple_assign_set_rhs_from_tree (&gsi, unshare_expr (tmp));
1144 use_stmt = gsi_stmt (gsi);
1145 update_stmt (use_stmt);
1147 if (dump_file && (dump_flags & TDF_DETAILS))
1149 fprintf (dump_file, " Replaced '");
1150 print_gimple_expr (dump_file, stmt, 0, dump_flags);
1151 fprintf (dump_file, "' with '");
1152 print_gimple_expr (dump_file, use_stmt, 0, dump_flags);
1153 fprintf (dump_file, "'\n");
1156 /* When we remove stmt now the iterator defgsi goes off it's current
1157 sequence, hence advance it now. */
1160 /* Remove defining statements. */
1161 return remove_prop_source_from_use (name);
1169 /* GSI_P points to a statement which performs a narrowing integral
1172 Look for cases like:
1182 If T is narrower than X's type and C merely masks off bits outside
1183 of (T) and nothing else.
1185 Normally we'd let DCE remove the dead statement. But no DCE runs
1186 after the last forwprop/combine pass, so we remove the obviously
1187 dead code ourselves.
1189 Return TRUE if a change was made, FALSE otherwise. */
1192 simplify_conversion_from_bitmask (gimple_stmt_iterator *gsi_p)
1194 gimple stmt = gsi_stmt (*gsi_p);
1195 gimple rhs_def_stmt = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
1197 /* See if the input for the conversion was set via a BIT_AND_EXPR and
1198 the only use of the BIT_AND_EXPR result is the conversion. */
1199 if (is_gimple_assign (rhs_def_stmt)
1200 && gimple_assign_rhs_code (rhs_def_stmt) == BIT_AND_EXPR
1201 && has_single_use (gimple_assign_lhs (rhs_def_stmt)))
1203 tree rhs_def_operand1 = gimple_assign_rhs1 (rhs_def_stmt);
1204 tree rhs_def_operand2 = gimple_assign_rhs2 (rhs_def_stmt);
1205 tree lhs_type = TREE_TYPE (gimple_assign_lhs (stmt));
1207 /* Now verify suitability of the BIT_AND_EXPR's operands.
1208 The first must be an SSA_NAME that we can propagate and the
1209 second must be an integer constant that masks out all the
1210 bits outside the final result's type, but nothing else. */
1211 if (TREE_CODE (rhs_def_operand1) == SSA_NAME
1212 && ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs_def_operand1)
1213 && TREE_CODE (rhs_def_operand2) == INTEGER_CST
1214 && operand_equal_p (rhs_def_operand2,
1215 build_low_bits_mask (TREE_TYPE (rhs_def_operand2),
1216 TYPE_PRECISION (lhs_type)),
1219 /* This is an optimizable case. Replace the source operand
1220 in the conversion with the first source operand of the
1222 gimple_assign_set_rhs1 (stmt, rhs_def_operand1);
1223 stmt = gsi_stmt (*gsi_p);
1226 /* There is no DCE after the last forwprop pass. It's
1227 easy to clean up the first order effects here. */
1228 gimple_stmt_iterator si;
1229 si = gsi_for_stmt (rhs_def_stmt);
1230 gsi_remove (&si, true);
1231 release_defs (rhs_def_stmt);
1240 /* If we have lhs = ~x (STMT), look and see if earlier we had x = ~y.
1241 If so, we can change STMT into lhs = y which can later be copy
1242 propagated. Similarly for negation.
1244 This could trivially be formulated as a forward propagation
1245 to immediate uses. However, we already had an implementation
1246 from DOM which used backward propagation via the use-def links.
1248 It turns out that backward propagation is actually faster as
1249 there's less work to do for each NOT/NEG expression we find.
1250 Backwards propagation needs to look at the statement in a single
1251 backlink. Forward propagation needs to look at potentially more
1252 than one forward link.
1254 Returns true when the statement was changed. */
1257 simplify_not_neg_expr (gimple_stmt_iterator *gsi_p)
1259 gimple stmt = gsi_stmt (*gsi_p);
1260 tree rhs = gimple_assign_rhs1 (stmt);
1261 gimple rhs_def_stmt = SSA_NAME_DEF_STMT (rhs);
1263 /* See if the RHS_DEF_STMT has the same form as our statement. */
1264 if (is_gimple_assign (rhs_def_stmt)
1265 && gimple_assign_rhs_code (rhs_def_stmt) == gimple_assign_rhs_code (stmt))
1267 tree rhs_def_operand = gimple_assign_rhs1 (rhs_def_stmt);
1269 /* Verify that RHS_DEF_OPERAND is a suitable SSA_NAME. */
1270 if (TREE_CODE (rhs_def_operand) == SSA_NAME
1271 && ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs_def_operand))
1273 gimple_assign_set_rhs_from_tree (gsi_p, rhs_def_operand);
1274 stmt = gsi_stmt (*gsi_p);
1283 /* Helper function for simplify_gimple_switch. Remove case labels that
1284 have values outside the range of the new type. */
1287 simplify_gimple_switch_label_vec (gimple stmt, tree index_type)
1289 unsigned int branch_num = gimple_switch_num_labels (stmt);
1290 auto_vec<tree> labels (branch_num);
1291 unsigned int i, len;
1293 /* Collect the existing case labels in a VEC, and preprocess it as if
1294 we are gimplifying a GENERIC SWITCH_EXPR. */
1295 for (i = 1; i < branch_num; i++)
1296 labels.quick_push (gimple_switch_label (stmt, i));
1297 preprocess_case_label_vec_for_gimple (labels, index_type, NULL);
1299 /* If any labels were removed, replace the existing case labels
1300 in the GIMPLE_SWITCH statement with the correct ones.
1301 Note that the type updates were done in-place on the case labels,
1302 so we only have to replace the case labels in the GIMPLE_SWITCH
1303 if the number of labels changed. */
1304 len = labels.length ();
1305 if (len < branch_num - 1)
1307 bitmap target_blocks;
1311 /* Corner case: *all* case labels have been removed as being
1312 out-of-range for INDEX_TYPE. Push one label and let the
1313 CFG cleanups deal with this further. */
1318 label = CASE_LABEL (gimple_switch_default_label (stmt));
1319 elt = build_case_label (build_int_cst (index_type, 0), NULL, label);
1320 labels.quick_push (elt);
1324 for (i = 0; i < labels.length (); i++)
1325 gimple_switch_set_label (stmt, i + 1, labels[i]);
1326 for (i++ ; i < branch_num; i++)
1327 gimple_switch_set_label (stmt, i, NULL_TREE);
1328 gimple_switch_set_num_labels (stmt, len + 1);
1330 /* Cleanup any edges that are now dead. */
1331 target_blocks = BITMAP_ALLOC (NULL);
1332 for (i = 0; i < gimple_switch_num_labels (stmt); i++)
1334 tree elt = gimple_switch_label (stmt, i);
1335 basic_block target = label_to_block (CASE_LABEL (elt));
1336 bitmap_set_bit (target_blocks, target->index);
1338 for (ei = ei_start (gimple_bb (stmt)->succs); (e = ei_safe_edge (ei)); )
1340 if (! bitmap_bit_p (target_blocks, e->dest->index))
1344 free_dominance_info (CDI_DOMINATORS);
1349 BITMAP_FREE (target_blocks);
1353 /* STMT is a SWITCH_EXPR for which we attempt to find equivalent forms of
1354 the condition which we may be able to optimize better. */
1357 simplify_gimple_switch (gimple stmt)
1359 tree cond = gimple_switch_index (stmt);
1363 /* The optimization that we really care about is removing unnecessary
1364 casts. That will let us do much better in propagating the inferred
1365 constant at the switch target. */
1366 if (TREE_CODE (cond) == SSA_NAME)
1368 def_stmt = SSA_NAME_DEF_STMT (cond);
1369 if (is_gimple_assign (def_stmt))
1371 if (gimple_assign_rhs_code (def_stmt) == NOP_EXPR)
1376 def = gimple_assign_rhs1 (def_stmt);
1378 to = TREE_TYPE (cond);
1379 ti = TREE_TYPE (def);
1381 /* If we have an extension that preserves value, then we
1382 can copy the source value into the switch. */
1384 need_precision = TYPE_PRECISION (ti);
1386 if (! INTEGRAL_TYPE_P (ti))
1388 else if (TYPE_UNSIGNED (to) && !TYPE_UNSIGNED (ti))
1390 else if (!TYPE_UNSIGNED (to) && TYPE_UNSIGNED (ti))
1391 need_precision += 1;
1392 if (TYPE_PRECISION (to) < need_precision)
1397 gimple_switch_set_index (stmt, def);
1398 simplify_gimple_switch_label_vec (stmt, ti);
1409 /* For pointers p2 and p1 return p2 - p1 if the
1410 difference is known and constant, otherwise return NULL. */
1413 constant_pointer_difference (tree p1, tree p2)
1416 #define CPD_ITERATIONS 5
1417 tree exps[2][CPD_ITERATIONS];
1418 tree offs[2][CPD_ITERATIONS];
1421 for (i = 0; i < 2; i++)
1423 tree p = i ? p1 : p2;
1424 tree off = size_zero_node;
1426 enum tree_code code;
1428 /* For each of p1 and p2 we need to iterate at least
1429 twice, to handle ADDR_EXPR directly in p1/p2,
1430 SSA_NAME with ADDR_EXPR or POINTER_PLUS_EXPR etc.
1431 on definition's stmt RHS. Iterate a few extra times. */
1435 if (!POINTER_TYPE_P (TREE_TYPE (p)))
1437 if (TREE_CODE (p) == ADDR_EXPR)
1439 tree q = TREE_OPERAND (p, 0);
1440 HOST_WIDE_INT offset;
1441 tree base = get_addr_base_and_unit_offset (q, &offset);
1446 off = size_binop (PLUS_EXPR, off, size_int (offset));
1448 if (TREE_CODE (q) == MEM_REF
1449 && TREE_CODE (TREE_OPERAND (q, 0)) == SSA_NAME)
1451 p = TREE_OPERAND (q, 0);
1452 off = size_binop (PLUS_EXPR, off,
1453 double_int_to_tree (sizetype,
1454 mem_ref_offset (q)));
1463 if (TREE_CODE (p) != SSA_NAME)
1467 if (j == CPD_ITERATIONS)
1469 stmt = SSA_NAME_DEF_STMT (p);
1470 if (!is_gimple_assign (stmt) || gimple_assign_lhs (stmt) != p)
1472 code = gimple_assign_rhs_code (stmt);
1473 if (code == POINTER_PLUS_EXPR)
1475 if (TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST)
1477 off = size_binop (PLUS_EXPR, off, gimple_assign_rhs2 (stmt));
1478 p = gimple_assign_rhs1 (stmt);
1480 else if (code == ADDR_EXPR || code == NOP_EXPR)
1481 p = gimple_assign_rhs1 (stmt);
1489 for (i = 0; i < cnt[0]; i++)
1490 for (j = 0; j < cnt[1]; j++)
1491 if (exps[0][i] == exps[1][j])
1492 return size_binop (MINUS_EXPR, offs[0][i], offs[1][j]);
1497 /* *GSI_P is a GIMPLE_CALL to a builtin function.
1499 memcpy (p, "abcd", 4);
1500 memset (p + 4, ' ', 3);
1502 memcpy (p, "abcd ", 7);
1503 call if the latter can be stored by pieces during expansion. */
1506 simplify_builtin_call (gimple_stmt_iterator *gsi_p, tree callee2)
1508 gimple stmt1, stmt2 = gsi_stmt (*gsi_p);
1509 tree vuse = gimple_vuse (stmt2);
1512 stmt1 = SSA_NAME_DEF_STMT (vuse);
1514 switch (DECL_FUNCTION_CODE (callee2))
1516 case BUILT_IN_MEMSET:
1517 if (gimple_call_num_args (stmt2) != 3
1518 || gimple_call_lhs (stmt2)
1520 || BITS_PER_UNIT != 8)
1525 tree ptr1, src1, str1, off1, len1, lhs1;
1526 tree ptr2 = gimple_call_arg (stmt2, 0);
1527 tree val2 = gimple_call_arg (stmt2, 1);
1528 tree len2 = gimple_call_arg (stmt2, 2);
1529 tree diff, vdef, new_str_cst;
1531 unsigned int ptr1_align;
1532 unsigned HOST_WIDE_INT src_len;
1534 use_operand_p use_p;
1536 if (!tree_fits_shwi_p (val2)
1537 || !tree_fits_uhwi_p (len2))
1539 if (is_gimple_call (stmt1))
1541 /* If first stmt is a call, it needs to be memcpy
1542 or mempcpy, with string literal as second argument and
1544 callee1 = gimple_call_fndecl (stmt1);
1545 if (callee1 == NULL_TREE
1546 || DECL_BUILT_IN_CLASS (callee1) != BUILT_IN_NORMAL
1547 || gimple_call_num_args (stmt1) != 3)
1549 if (DECL_FUNCTION_CODE (callee1) != BUILT_IN_MEMCPY
1550 && DECL_FUNCTION_CODE (callee1) != BUILT_IN_MEMPCPY)
1552 ptr1 = gimple_call_arg (stmt1, 0);
1553 src1 = gimple_call_arg (stmt1, 1);
1554 len1 = gimple_call_arg (stmt1, 2);
1555 lhs1 = gimple_call_lhs (stmt1);
1556 if (!tree_fits_uhwi_p (len1))
1558 str1 = string_constant (src1, &off1);
1559 if (str1 == NULL_TREE)
1561 if (!tree_fits_uhwi_p (off1)
1562 || compare_tree_int (off1, TREE_STRING_LENGTH (str1) - 1) > 0
1563 || compare_tree_int (len1, TREE_STRING_LENGTH (str1)
1564 - tree_to_uhwi (off1)) > 0
1565 || TREE_CODE (TREE_TYPE (str1)) != ARRAY_TYPE
1566 || TYPE_MODE (TREE_TYPE (TREE_TYPE (str1)))
1567 != TYPE_MODE (char_type_node))
1570 else if (gimple_assign_single_p (stmt1))
1572 /* Otherwise look for length 1 memcpy optimized into
1574 ptr1 = gimple_assign_lhs (stmt1);
1575 src1 = gimple_assign_rhs1 (stmt1);
1576 if (TREE_CODE (ptr1) != MEM_REF
1577 || TYPE_MODE (TREE_TYPE (ptr1)) != TYPE_MODE (char_type_node)
1578 || !tree_fits_shwi_p (src1))
1580 ptr1 = build_fold_addr_expr (ptr1);
1581 callee1 = NULL_TREE;
1582 len1 = size_one_node;
1584 off1 = size_zero_node;
1590 diff = constant_pointer_difference (ptr1, ptr2);
1591 if (diff == NULL && lhs1 != NULL)
1593 diff = constant_pointer_difference (lhs1, ptr2);
1594 if (DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY
1596 diff = size_binop (PLUS_EXPR, diff,
1597 fold_convert (sizetype, len1));
1599 /* If the difference between the second and first destination pointer
1600 is not constant, or is bigger than memcpy length, bail out. */
1602 || !tree_fits_uhwi_p (diff)
1603 || tree_int_cst_lt (len1, diff))
1606 /* Use maximum of difference plus memset length and memcpy length
1607 as the new memcpy length, if it is too big, bail out. */
1608 src_len = tree_to_uhwi (diff);
1609 src_len += tree_to_uhwi (len2);
1610 if (src_len < tree_to_uhwi (len1))
1611 src_len = tree_to_uhwi (len1);
1615 /* If mempcpy value is used elsewhere, bail out, as mempcpy
1616 with bigger length will return different result. */
1617 if (lhs1 != NULL_TREE
1618 && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY
1619 && (TREE_CODE (lhs1) != SSA_NAME
1620 || !single_imm_use (lhs1, &use_p, &use_stmt)
1621 || use_stmt != stmt2))
1624 /* If anything reads memory in between memcpy and memset
1625 call, the modified memcpy call might change it. */
1626 vdef = gimple_vdef (stmt1);
1628 && (!single_imm_use (vdef, &use_p, &use_stmt)
1629 || use_stmt != stmt2))
1632 ptr1_align = get_pointer_alignment (ptr1);
1633 /* Construct the new source string literal. */
1634 src_buf = XALLOCAVEC (char, src_len + 1);
1637 TREE_STRING_POINTER (str1) + tree_to_uhwi (off1),
1638 tree_to_uhwi (len1));
1640 src_buf[0] = tree_to_shwi (src1);
1641 memset (src_buf + tree_to_uhwi (diff),
1642 tree_to_shwi (val2), tree_to_uhwi (len2));
1643 src_buf[src_len] = '\0';
1644 /* Neither builtin_strncpy_read_str nor builtin_memcpy_read_str
1645 handle embedded '\0's. */
1646 if (strlen (src_buf) != src_len)
1648 rtl_profile_for_bb (gimple_bb (stmt2));
1649 /* If the new memcpy wouldn't be emitted by storing the literal
1650 by pieces, this optimization might enlarge .rodata too much,
1651 as commonly used string literals couldn't be shared any
1653 if (!can_store_by_pieces (src_len,
1654 builtin_strncpy_read_str,
1655 src_buf, ptr1_align, false))
1658 new_str_cst = build_string_literal (src_len, src_buf);
1661 /* If STMT1 is a mem{,p}cpy call, adjust it and remove
1663 if (lhs1 && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY)
1664 gimple_call_set_lhs (stmt1, NULL_TREE);
1665 gimple_call_set_arg (stmt1, 1, new_str_cst);
1666 gimple_call_set_arg (stmt1, 2,
1667 build_int_cst (TREE_TYPE (len1), src_len));
1668 update_stmt (stmt1);
1669 unlink_stmt_vdef (stmt2);
1670 gsi_remove (gsi_p, true);
1671 release_defs (stmt2);
1672 if (lhs1 && DECL_FUNCTION_CODE (callee1) == BUILT_IN_MEMPCPY)
1673 release_ssa_name (lhs1);
1678 /* Otherwise, if STMT1 is length 1 memcpy optimized into
1679 assignment, remove STMT1 and change memset call into
1681 gimple_stmt_iterator gsi = gsi_for_stmt (stmt1);
1683 if (!is_gimple_val (ptr1))
1684 ptr1 = force_gimple_operand_gsi (gsi_p, ptr1, true, NULL_TREE,
1685 true, GSI_SAME_STMT);
1686 gimple_call_set_fndecl (stmt2,
1687 builtin_decl_explicit (BUILT_IN_MEMCPY));
1688 gimple_call_set_arg (stmt2, 0, ptr1);
1689 gimple_call_set_arg (stmt2, 1, new_str_cst);
1690 gimple_call_set_arg (stmt2, 2,
1691 build_int_cst (TREE_TYPE (len2), src_len));
1692 unlink_stmt_vdef (stmt1);
1693 gsi_remove (&gsi, true);
1694 release_defs (stmt1);
1695 update_stmt (stmt2);
1706 /* Checks if expression has type of one-bit precision, or is a known
1707 truth-valued expression. */
1709 truth_valued_ssa_name (tree name)
1712 tree type = TREE_TYPE (name);
1714 if (!INTEGRAL_TYPE_P (type))
1716 /* Don't check here for BOOLEAN_TYPE as the precision isn't
1717 necessarily one and so ~X is not equal to !X. */
1718 if (TYPE_PRECISION (type) == 1)
1720 def = SSA_NAME_DEF_STMT (name);
1721 if (is_gimple_assign (def))
1722 return truth_value_p (gimple_assign_rhs_code (def));
1726 /* Helper routine for simplify_bitwise_binary_1 function.
1727 Return for the SSA name NAME the expression X if it mets condition
1728 NAME = !X. Otherwise return NULL_TREE.
1729 Detected patterns for NAME = !X are:
1730 !X and X == 0 for X with integral type.
1731 X ^ 1, X != 1,or ~X for X with integral type with precision of one. */
1733 lookup_logical_inverted_value (tree name)
1736 enum tree_code code;
1739 /* If name has none-intergal type, or isn't a SSA_NAME, then
1741 if (TREE_CODE (name) != SSA_NAME
1742 || !INTEGRAL_TYPE_P (TREE_TYPE (name)))
1744 def = SSA_NAME_DEF_STMT (name);
1745 if (!is_gimple_assign (def))
1748 code = gimple_assign_rhs_code (def);
1749 op1 = gimple_assign_rhs1 (def);
1752 /* Get for EQ_EXPR or BIT_XOR_EXPR operation the second operand.
1753 If CODE isn't an EQ_EXPR, BIT_XOR_EXPR, or BIT_NOT_EXPR, then return. */
1754 if (code == EQ_EXPR || code == NE_EXPR
1755 || code == BIT_XOR_EXPR)
1756 op2 = gimple_assign_rhs2 (def);
1761 if (truth_valued_ssa_name (name))
1765 /* Check if we have X == 0 and X has an integral type. */
1766 if (!INTEGRAL_TYPE_P (TREE_TYPE (op1)))
1768 if (integer_zerop (op2))
1772 /* Check if we have X != 1 and X is a truth-valued. */
1773 if (!INTEGRAL_TYPE_P (TREE_TYPE (op1)))
1775 if (integer_onep (op2) && truth_valued_ssa_name (op1))
1779 /* Check if we have X ^ 1 and X is truth valued. */
1780 if (integer_onep (op2) && truth_valued_ssa_name (op1))
1790 /* Optimize ARG1 CODE ARG2 to a constant for bitwise binary
1791 operations CODE, if one operand has the logically inverted
1792 value of the other. */
1794 simplify_bitwise_binary_1 (enum tree_code code, tree type,
1795 tree arg1, tree arg2)
1799 /* If CODE isn't a bitwise binary operation, return NULL_TREE. */
1800 if (code != BIT_AND_EXPR && code != BIT_IOR_EXPR
1801 && code != BIT_XOR_EXPR)
1804 /* First check if operands ARG1 and ARG2 are equal. If so
1805 return NULL_TREE as this optimization is handled fold_stmt. */
1808 /* See if we have in arguments logical-not patterns. */
1809 if (((anot = lookup_logical_inverted_value (arg1)) == NULL_TREE
1811 && ((anot = lookup_logical_inverted_value (arg2)) == NULL_TREE
1816 if (code == BIT_AND_EXPR)
1817 return fold_convert (type, integer_zero_node);
1818 /* X | !X -> 1 and X ^ !X -> 1, if X is truth-valued. */
1819 if (truth_valued_ssa_name (anot))
1820 return fold_convert (type, integer_one_node);
1822 /* ??? Otherwise result is (X != 0 ? X : 1). not handled. */
1826 /* Given a ssa_name in NAME see if it was defined by an assignment and
1827 set CODE to be the code and ARG1 to the first operand on the rhs and ARG2
1828 to the second operand on the rhs. */
1831 defcodefor_name (tree name, enum tree_code *code, tree *arg1, tree *arg2)
1834 enum tree_code code1;
1838 enum gimple_rhs_class grhs_class;
1840 code1 = TREE_CODE (name);
1843 grhs_class = get_gimple_rhs_class (code1);
1845 if (code1 == SSA_NAME)
1847 def = SSA_NAME_DEF_STMT (name);
1849 if (def && is_gimple_assign (def)
1850 && can_propagate_from (def))
1852 code1 = gimple_assign_rhs_code (def);
1853 arg11 = gimple_assign_rhs1 (def);
1854 arg21 = gimple_assign_rhs2 (def);
1855 arg31 = gimple_assign_rhs2 (def);
1858 else if (grhs_class == GIMPLE_TERNARY_RHS
1859 || GIMPLE_BINARY_RHS
1861 || GIMPLE_SINGLE_RHS)
1862 extract_ops_from_tree_1 (name, &code1, &arg11, &arg21, &arg31);
1868 /* Ignore arg3 currently. */
1871 /* Return true if a conversion of an operand from type FROM to type TO
1872 should be applied after performing the operation instead. */
1875 hoist_conversion_for_bitop_p (tree to, tree from)
1877 /* That's a good idea if the conversion widens the operand, thus
1878 after hoisting the conversion the operation will be narrower. */
1879 if (TYPE_PRECISION (from) < TYPE_PRECISION (to))
1882 /* It's also a good idea if the conversion is to a non-integer mode. */
1883 if (GET_MODE_CLASS (TYPE_MODE (to)) != MODE_INT)
1886 /* Or if the precision of TO is not the same as the precision
1888 if (TYPE_PRECISION (to) != GET_MODE_PRECISION (TYPE_MODE (to)))
1894 /* GSI points to a statement of the form
1896 result = OP0 CODE OP1
1898 Where OP0 and OP1 are single bit SSA_NAMEs and CODE is either
1899 BIT_AND_EXPR or BIT_IOR_EXPR.
1901 If OP0 is fed by a bitwise negation of another single bit SSA_NAME,
1902 then we can simplify the two statements into a single LT_EXPR or LE_EXPR
1903 when code is BIT_AND_EXPR and BIT_IOR_EXPR respectively.
1905 If a simplification is made, return TRUE, else return FALSE. */
1907 simplify_bitwise_binary_boolean (gimple_stmt_iterator *gsi,
1908 enum tree_code code,
1911 gimple op0_def_stmt = SSA_NAME_DEF_STMT (op0);
1913 if (!is_gimple_assign (op0_def_stmt)
1914 || (gimple_assign_rhs_code (op0_def_stmt) != BIT_NOT_EXPR))
1917 tree x = gimple_assign_rhs1 (op0_def_stmt);
1918 if (TREE_CODE (x) == SSA_NAME
1919 && INTEGRAL_TYPE_P (TREE_TYPE (x))
1920 && TYPE_PRECISION (TREE_TYPE (x)) == 1
1921 && TYPE_UNSIGNED (TREE_TYPE (x)) == TYPE_UNSIGNED (TREE_TYPE (op1)))
1923 enum tree_code newcode;
1925 gimple stmt = gsi_stmt (*gsi);
1926 gimple_assign_set_rhs1 (stmt, x);
1927 gimple_assign_set_rhs2 (stmt, op1);
1928 if (code == BIT_AND_EXPR)
1929 newcode = TYPE_UNSIGNED (TREE_TYPE (x)) ? LT_EXPR : GT_EXPR;
1931 newcode = TYPE_UNSIGNED (TREE_TYPE (x)) ? LE_EXPR : GE_EXPR;
1932 gimple_assign_set_rhs_code (stmt, newcode);
1940 /* Simplify bitwise binary operations.
1941 Return true if a transformation applied, otherwise return false. */
1944 simplify_bitwise_binary (gimple_stmt_iterator *gsi)
1946 gimple stmt = gsi_stmt (*gsi);
1947 tree arg1 = gimple_assign_rhs1 (stmt);
1948 tree arg2 = gimple_assign_rhs2 (stmt);
1949 enum tree_code code = gimple_assign_rhs_code (stmt);
1951 tree def1_arg1, def1_arg2, def2_arg1, def2_arg2;
1952 enum tree_code def1_code, def2_code;
1954 defcodefor_name (arg1, &def1_code, &def1_arg1, &def1_arg2);
1955 defcodefor_name (arg2, &def2_code, &def2_arg1, &def2_arg2);
1957 /* Try to fold (type) X op CST -> (type) (X op ((type-x) CST))
1959 if (TREE_CODE (arg2) == INTEGER_CST
1960 && CONVERT_EXPR_CODE_P (def1_code)
1961 && hoist_conversion_for_bitop_p (TREE_TYPE (arg1), TREE_TYPE (def1_arg1))
1962 && INTEGRAL_TYPE_P (TREE_TYPE (def1_arg1))
1963 && int_fits_type_p (arg2, TREE_TYPE (def1_arg1)))
1966 tree tem = make_ssa_name (TREE_TYPE (def1_arg1), NULL);
1968 gimple_build_assign_with_ops (code, tem, def1_arg1,
1969 fold_convert_loc (gimple_location (stmt),
1970 TREE_TYPE (def1_arg1),
1972 gimple_set_location (newop, gimple_location (stmt));
1973 gsi_insert_before (gsi, newop, GSI_SAME_STMT);
1974 gimple_assign_set_rhs_with_ops_1 (gsi, NOP_EXPR,
1975 tem, NULL_TREE, NULL_TREE);
1976 update_stmt (gsi_stmt (*gsi));
1980 /* For bitwise binary operations apply operand conversions to the
1981 binary operation result instead of to the operands. This allows
1982 to combine successive conversions and bitwise binary operations. */
1983 if (CONVERT_EXPR_CODE_P (def1_code)
1984 && CONVERT_EXPR_CODE_P (def2_code)
1985 && types_compatible_p (TREE_TYPE (def1_arg1), TREE_TYPE (def2_arg1))
1986 && hoist_conversion_for_bitop_p (TREE_TYPE (arg1), TREE_TYPE (def1_arg1)))
1989 tree tem = make_ssa_name (TREE_TYPE (def1_arg1), NULL);
1990 newop = gimple_build_assign_with_ops (code, tem, def1_arg1, def2_arg1);
1991 gimple_set_location (newop, gimple_location (stmt));
1992 gsi_insert_before (gsi, newop, GSI_SAME_STMT);
1993 gimple_assign_set_rhs_with_ops_1 (gsi, NOP_EXPR,
1994 tem, NULL_TREE, NULL_TREE);
1995 update_stmt (gsi_stmt (*gsi));
2000 /* Simplify (A & B) OP0 (C & B) to (A OP0 C) & B. */
2001 if (def1_code == def2_code
2002 && def1_code == BIT_AND_EXPR
2003 && operand_equal_for_phi_arg_p (def1_arg2,
2009 tree inner = fold_build2 (code, TREE_TYPE (arg2), a, c);
2010 /* If A OP0 C (this usually means C is the same as A) is 0
2011 then fold it down correctly. */
2012 if (integer_zerop (inner))
2014 gimple_assign_set_rhs_from_tree (gsi, inner);
2018 /* If A OP0 C (this usually means C is the same as A) is a ssa_name
2019 then fold it down correctly. */
2020 else if (TREE_CODE (inner) == SSA_NAME)
2022 tree outer = fold_build2 (def1_code, TREE_TYPE (inner),
2024 gimple_assign_set_rhs_from_tree (gsi, outer);
2032 tem = make_ssa_name (TREE_TYPE (arg2), NULL);
2033 newop = gimple_build_assign_with_ops (code, tem, a, c);
2034 gimple_set_location (newop, gimple_location (stmt));
2035 /* Make sure to re-process the new stmt as it's walking upwards. */
2036 gsi_insert_before (gsi, newop, GSI_NEW_STMT);
2037 gimple_assign_set_rhs1 (stmt, tem);
2038 gimple_assign_set_rhs2 (stmt, b);
2039 gimple_assign_set_rhs_code (stmt, def1_code);
2045 /* (a | CST1) & CST2 -> (a & CST2) | (CST1 & CST2). */
2046 if (code == BIT_AND_EXPR
2047 && def1_code == BIT_IOR_EXPR
2048 && CONSTANT_CLASS_P (arg2)
2049 && CONSTANT_CLASS_P (def1_arg2))
2051 tree cst = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg2),
2055 if (integer_zerop (cst))
2057 gimple_assign_set_rhs1 (stmt, def1_arg1);
2061 tem = make_ssa_name (TREE_TYPE (arg2), NULL);
2062 newop = gimple_build_assign_with_ops (BIT_AND_EXPR,
2063 tem, def1_arg1, arg2);
2064 gimple_set_location (newop, gimple_location (stmt));
2065 /* Make sure to re-process the new stmt as it's walking upwards. */
2066 gsi_insert_before (gsi, newop, GSI_NEW_STMT);
2067 gimple_assign_set_rhs1 (stmt, tem);
2068 gimple_assign_set_rhs2 (stmt, cst);
2069 gimple_assign_set_rhs_code (stmt, BIT_IOR_EXPR);
2074 /* Combine successive equal operations with constants. */
2075 if ((code == BIT_AND_EXPR
2076 || code == BIT_IOR_EXPR
2077 || code == BIT_XOR_EXPR)
2078 && def1_code == code
2079 && CONSTANT_CLASS_P (arg2)
2080 && CONSTANT_CLASS_P (def1_arg2))
2082 tree cst = fold_build2 (code, TREE_TYPE (arg2),
2084 gimple_assign_set_rhs1 (stmt, def1_arg1);
2085 gimple_assign_set_rhs2 (stmt, cst);
2090 /* Canonicalize X ^ ~0 to ~X. */
2091 if (code == BIT_XOR_EXPR
2092 && integer_all_onesp (arg2))
2094 gimple_assign_set_rhs_with_ops (gsi, BIT_NOT_EXPR, arg1, NULL_TREE);
2095 gcc_assert (gsi_stmt (*gsi) == stmt);
2100 /* Try simple folding for X op !X, and X op X. */
2101 res = simplify_bitwise_binary_1 (code, TREE_TYPE (arg1), arg1, arg2);
2102 if (res != NULL_TREE)
2104 gimple_assign_set_rhs_from_tree (gsi, res);
2105 update_stmt (gsi_stmt (*gsi));
2109 if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR)
2111 enum tree_code ocode = code == BIT_AND_EXPR ? BIT_IOR_EXPR : BIT_AND_EXPR;
2112 if (def1_code == ocode)
2115 enum tree_code coden;
2117 /* ( X | Y) & X -> X */
2118 /* ( X & Y) | X -> X */
2122 gimple_assign_set_rhs_from_tree (gsi, x);
2123 update_stmt (gsi_stmt (*gsi));
2127 defcodefor_name (def1_arg1, &coden, &a1, &a2);
2128 /* (~X | Y) & X -> X & Y */
2129 /* (~X & Y) | X -> X | Y */
2130 if (coden == BIT_NOT_EXPR && a1 == x)
2132 gimple_assign_set_rhs_with_ops (gsi, code,
2134 gcc_assert (gsi_stmt (*gsi) == stmt);
2138 defcodefor_name (def1_arg2, &coden, &a1, &a2);
2139 /* (Y | ~X) & X -> X & Y */
2140 /* (Y & ~X) | X -> X | Y */
2141 if (coden == BIT_NOT_EXPR && a1 == x)
2143 gimple_assign_set_rhs_with_ops (gsi, code,
2145 gcc_assert (gsi_stmt (*gsi) == stmt);
2150 if (def2_code == ocode)
2152 enum tree_code coden;
2155 /* X & ( X | Y) -> X */
2156 /* X | ( X & Y) -> X */
2160 gimple_assign_set_rhs_from_tree (gsi, x);
2161 update_stmt (gsi_stmt (*gsi));
2164 defcodefor_name (def2_arg1, &coden, &a1, NULL);
2165 /* (~X | Y) & X -> X & Y */
2166 /* (~X & Y) | X -> X | Y */
2167 if (coden == BIT_NOT_EXPR && a1 == x)
2169 gimple_assign_set_rhs_with_ops (gsi, code,
2171 gcc_assert (gsi_stmt (*gsi) == stmt);
2175 defcodefor_name (def2_arg2, &coden, &a1, NULL);
2176 /* (Y | ~X) & X -> X & Y */
2177 /* (Y & ~X) | X -> X | Y */
2178 if (coden == BIT_NOT_EXPR && a1 == x)
2180 gimple_assign_set_rhs_with_ops (gsi, code,
2182 gcc_assert (gsi_stmt (*gsi) == stmt);
2188 /* If arg1 and arg2 are booleans (or any single bit type)
2189 then try to simplify:
2196 But only do this if our result feeds into a comparison as
2197 this transformation is not always a win, particularly on
2198 targets with and-not instructions. */
2199 if (TREE_CODE (arg1) == SSA_NAME
2200 && TREE_CODE (arg2) == SSA_NAME
2201 && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
2202 && TYPE_PRECISION (TREE_TYPE (arg1)) == 1
2203 && TYPE_PRECISION (TREE_TYPE (arg2)) == 1
2204 && (TYPE_UNSIGNED (TREE_TYPE (arg1))
2205 == TYPE_UNSIGNED (TREE_TYPE (arg2))))
2207 use_operand_p use_p;
2210 if (single_imm_use (gimple_assign_lhs (stmt), &use_p, &use_stmt))
2212 if (gimple_code (use_stmt) == GIMPLE_COND
2213 && gimple_cond_lhs (use_stmt) == gimple_assign_lhs (stmt)
2214 && integer_zerop (gimple_cond_rhs (use_stmt))
2215 && gimple_cond_code (use_stmt) == NE_EXPR)
2217 if (simplify_bitwise_binary_boolean (gsi, code, arg1, arg2))
2219 if (simplify_bitwise_binary_boolean (gsi, code, arg2, arg1))
2229 /* Recognize rotation patterns. Return true if a transformation
2230 applied, otherwise return false.
2232 We are looking for X with unsigned type T with bitsize B, OP being
2233 +, | or ^, some type T2 wider than T and
2234 (X << CNT1) OP (X >> CNT2) iff CNT1 + CNT2 == B
2235 ((T) ((T2) X << CNT1)) OP ((T) ((T2) X >> CNT2)) iff CNT1 + CNT2 == B
2236 (X << Y) OP (X >> (B - Y))
2237 (X << (int) Y) OP (X >> (int) (B - Y))
2238 ((T) ((T2) X << Y)) OP ((T) ((T2) X >> (B - Y)))
2239 ((T) ((T2) X << (int) Y)) OP ((T) ((T2) X >> (int) (B - Y)))
2240 (X << Y) | (X >> ((-Y) & (B - 1)))
2241 (X << (int) Y) | (X >> (int) ((-Y) & (B - 1)))
2242 ((T) ((T2) X << Y)) | ((T) ((T2) X >> ((-Y) & (B - 1))))
2243 ((T) ((T2) X << (int) Y)) | ((T) ((T2) X >> (int) ((-Y) & (B - 1))))
2245 and transform these into:
2249 Note, in the patterns with T2 type, the type of OP operands
2250 might be even a signed type, but should have precision B. */
2253 simplify_rotate (gimple_stmt_iterator *gsi)
2255 gimple stmt = gsi_stmt (*gsi);
2256 tree arg[2], rtype, rotcnt = NULL_TREE;
2257 tree def_arg1[2], def_arg2[2];
2258 enum tree_code def_code[2];
2261 bool swapped_p = false;
2264 arg[0] = gimple_assign_rhs1 (stmt);
2265 arg[1] = gimple_assign_rhs2 (stmt);
2266 rtype = TREE_TYPE (arg[0]);
2268 /* Only create rotates in complete modes. Other cases are not
2269 expanded properly. */
2270 if (!INTEGRAL_TYPE_P (rtype)
2271 || TYPE_PRECISION (rtype) != GET_MODE_PRECISION (TYPE_MODE (rtype)))
2274 for (i = 0; i < 2; i++)
2275 defcodefor_name (arg[i], &def_code[i], &def_arg1[i], &def_arg2[i]);
2277 /* Look through narrowing conversions. */
2278 if (CONVERT_EXPR_CODE_P (def_code[0])
2279 && CONVERT_EXPR_CODE_P (def_code[1])
2280 && INTEGRAL_TYPE_P (TREE_TYPE (def_arg1[0]))
2281 && INTEGRAL_TYPE_P (TREE_TYPE (def_arg1[1]))
2282 && TYPE_PRECISION (TREE_TYPE (def_arg1[0]))
2283 == TYPE_PRECISION (TREE_TYPE (def_arg1[1]))
2284 && TYPE_PRECISION (TREE_TYPE (def_arg1[0])) > TYPE_PRECISION (rtype)
2285 && has_single_use (arg[0])
2286 && has_single_use (arg[1]))
2288 for (i = 0; i < 2; i++)
2290 arg[i] = def_arg1[i];
2291 defcodefor_name (arg[i], &def_code[i], &def_arg1[i], &def_arg2[i]);
2295 /* One operand has to be LSHIFT_EXPR and one RSHIFT_EXPR. */
2296 for (i = 0; i < 2; i++)
2297 if (def_code[i] != LSHIFT_EXPR && def_code[i] != RSHIFT_EXPR)
2299 else if (!has_single_use (arg[i]))
2301 if (def_code[0] == def_code[1])
2304 /* If we've looked through narrowing conversions before, look through
2305 widening conversions from unsigned type with the same precision
2307 if (TYPE_PRECISION (TREE_TYPE (def_arg1[0])) != TYPE_PRECISION (rtype))
2308 for (i = 0; i < 2; i++)
2311 enum tree_code code;
2312 defcodefor_name (def_arg1[i], &code, &tem, NULL);
2313 if (!CONVERT_EXPR_CODE_P (code)
2314 || !INTEGRAL_TYPE_P (TREE_TYPE (tem))
2315 || TYPE_PRECISION (TREE_TYPE (tem)) != TYPE_PRECISION (rtype))
2319 /* Both shifts have to use the same first operand. */
2320 if (TREE_CODE (def_arg1[0]) != SSA_NAME || def_arg1[0] != def_arg1[1])
2322 if (!TYPE_UNSIGNED (TREE_TYPE (def_arg1[0])))
2325 /* CNT1 + CNT2 == B case above. */
2326 if (tree_fits_uhwi_p (def_arg2[0])
2327 && tree_fits_uhwi_p (def_arg2[1])
2328 && tree_to_uhwi (def_arg2[0])
2329 + tree_to_uhwi (def_arg2[1]) == TYPE_PRECISION (rtype))
2330 rotcnt = def_arg2[0];
2331 else if (TREE_CODE (def_arg2[0]) != SSA_NAME
2332 || TREE_CODE (def_arg2[1]) != SSA_NAME)
2336 tree cdef_arg1[2], cdef_arg2[2], def_arg2_alt[2];
2337 enum tree_code cdef_code[2];
2338 /* Look through conversion of the shift count argument.
2339 The C/C++ FE cast any shift count argument to integer_type_node.
2340 The only problem might be if the shift count type maximum value
2341 is equal or smaller than number of bits in rtype. */
2342 for (i = 0; i < 2; i++)
2344 def_arg2_alt[i] = def_arg2[i];
2345 defcodefor_name (def_arg2[i], &cdef_code[i],
2346 &cdef_arg1[i], &cdef_arg2[i]);
2347 if (CONVERT_EXPR_CODE_P (cdef_code[i])
2348 && INTEGRAL_TYPE_P (TREE_TYPE (cdef_arg1[i]))
2349 && TYPE_PRECISION (TREE_TYPE (cdef_arg1[i]))
2350 > floor_log2 (TYPE_PRECISION (rtype))
2351 && TYPE_PRECISION (TREE_TYPE (cdef_arg1[i]))
2352 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (cdef_arg1[i]))))
2354 def_arg2_alt[i] = cdef_arg1[i];
2355 defcodefor_name (def_arg2_alt[i], &cdef_code[i],
2356 &cdef_arg1[i], &cdef_arg2[i]);
2359 for (i = 0; i < 2; i++)
2360 /* Check for one shift count being Y and the other B - Y,
2361 with optional casts. */
2362 if (cdef_code[i] == MINUS_EXPR
2363 && tree_fits_shwi_p (cdef_arg1[i])
2364 && tree_to_shwi (cdef_arg1[i]) == TYPE_PRECISION (rtype)
2365 && TREE_CODE (cdef_arg2[i]) == SSA_NAME)
2368 enum tree_code code;
2370 if (cdef_arg2[i] == def_arg2[1 - i]
2371 || cdef_arg2[i] == def_arg2_alt[1 - i])
2373 rotcnt = cdef_arg2[i];
2376 defcodefor_name (cdef_arg2[i], &code, &tem, NULL);
2377 if (CONVERT_EXPR_CODE_P (code)
2378 && INTEGRAL_TYPE_P (TREE_TYPE (tem))
2379 && TYPE_PRECISION (TREE_TYPE (tem))
2380 > floor_log2 (TYPE_PRECISION (rtype))
2381 && TYPE_PRECISION (TREE_TYPE (tem))
2382 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem)))
2383 && (tem == def_arg2[1 - i]
2384 || tem == def_arg2_alt[1 - i]))
2390 /* The above sequence isn't safe for Y being 0,
2391 because then one of the shifts triggers undefined behavior.
2392 This alternative is safe even for rotation count of 0.
2393 One shift count is Y and the other (-Y) & (B - 1). */
2394 else if (cdef_code[i] == BIT_AND_EXPR
2395 && tree_fits_shwi_p (cdef_arg2[i])
2396 && tree_to_shwi (cdef_arg2[i])
2397 == TYPE_PRECISION (rtype) - 1
2398 && TREE_CODE (cdef_arg1[i]) == SSA_NAME
2399 && gimple_assign_rhs_code (stmt) == BIT_IOR_EXPR)
2402 enum tree_code code;
2404 defcodefor_name (cdef_arg1[i], &code, &tem, NULL);
2405 if (CONVERT_EXPR_CODE_P (code)
2406 && INTEGRAL_TYPE_P (TREE_TYPE (tem))
2407 && TYPE_PRECISION (TREE_TYPE (tem))
2408 > floor_log2 (TYPE_PRECISION (rtype))
2409 && TYPE_PRECISION (TREE_TYPE (tem))
2410 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem))))
2411 defcodefor_name (tem, &code, &tem, NULL);
2413 if (code == NEGATE_EXPR)
2415 if (tem == def_arg2[1 - i] || tem == def_arg2_alt[1 - i])
2420 defcodefor_name (tem, &code, &tem, NULL);
2421 if (CONVERT_EXPR_CODE_P (code)
2422 && INTEGRAL_TYPE_P (TREE_TYPE (tem))
2423 && TYPE_PRECISION (TREE_TYPE (tem))
2424 > floor_log2 (TYPE_PRECISION (rtype))
2425 && TYPE_PRECISION (TREE_TYPE (tem))
2426 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem)))
2427 && (tem == def_arg2[1 - i]
2428 || tem == def_arg2_alt[1 - i]))
2435 if (rotcnt == NULL_TREE)
2440 if (!useless_type_conversion_p (TREE_TYPE (def_arg2[0]),
2441 TREE_TYPE (rotcnt)))
2443 g = gimple_build_assign_with_ops (NOP_EXPR,
2444 make_ssa_name (TREE_TYPE (def_arg2[0]),
2447 gsi_insert_before (gsi, g, GSI_SAME_STMT);
2448 rotcnt = gimple_assign_lhs (g);
2450 lhs = gimple_assign_lhs (stmt);
2451 if (!useless_type_conversion_p (rtype, TREE_TYPE (def_arg1[0])))
2452 lhs = make_ssa_name (TREE_TYPE (def_arg1[0]), NULL);
2453 g = gimple_build_assign_with_ops (((def_code[0] == LSHIFT_EXPR) ^ swapped_p)
2454 ? LROTATE_EXPR : RROTATE_EXPR,
2455 lhs, def_arg1[0], rotcnt);
2456 if (!useless_type_conversion_p (rtype, TREE_TYPE (def_arg1[0])))
2458 gsi_insert_before (gsi, g, GSI_SAME_STMT);
2459 g = gimple_build_assign_with_ops (NOP_EXPR, gimple_assign_lhs (stmt),
2462 gsi_replace (gsi, g, false);
2466 /* Perform re-associations of the plus or minus statement STMT that are
2467 always permitted. Returns true if the CFG was changed. */
2470 associate_plusminus (gimple_stmt_iterator *gsi)
2472 gimple stmt = gsi_stmt (*gsi);
2473 tree rhs1 = gimple_assign_rhs1 (stmt);
2474 tree rhs2 = gimple_assign_rhs2 (stmt);
2475 enum tree_code code = gimple_assign_rhs_code (stmt);
2478 /* We can't reassociate at all for saturating types. */
2479 if (TYPE_SATURATING (TREE_TYPE (rhs1)))
2482 /* First contract negates. */
2487 /* A +- (-B) -> A -+ B. */
2488 if (TREE_CODE (rhs2) == SSA_NAME)
2490 gimple def_stmt = SSA_NAME_DEF_STMT (rhs2);
2491 if (is_gimple_assign (def_stmt)
2492 && gimple_assign_rhs_code (def_stmt) == NEGATE_EXPR
2493 && can_propagate_from (def_stmt))
2495 code = (code == MINUS_EXPR) ? PLUS_EXPR : MINUS_EXPR;
2496 gimple_assign_set_rhs_code (stmt, code);
2497 rhs2 = gimple_assign_rhs1 (def_stmt);
2498 gimple_assign_set_rhs2 (stmt, rhs2);
2499 gimple_set_modified (stmt, true);
2504 /* (-A) + B -> B - A. */
2505 if (TREE_CODE (rhs1) == SSA_NAME
2506 && code == PLUS_EXPR)
2508 gimple def_stmt = SSA_NAME_DEF_STMT (rhs1);
2509 if (is_gimple_assign (def_stmt)
2510 && gimple_assign_rhs_code (def_stmt) == NEGATE_EXPR
2511 && can_propagate_from (def_stmt))
2514 gimple_assign_set_rhs_code (stmt, code);
2516 gimple_assign_set_rhs1 (stmt, rhs1);
2517 rhs2 = gimple_assign_rhs1 (def_stmt);
2518 gimple_assign_set_rhs2 (stmt, rhs2);
2519 gimple_set_modified (stmt, true);
2526 /* We can't reassociate floating-point or fixed-point plus or minus
2527 because of saturation to +-Inf. */
2528 if (FLOAT_TYPE_P (TREE_TYPE (rhs1))
2529 || FIXED_POINT_TYPE_P (TREE_TYPE (rhs1)))
2532 /* Second match patterns that allow contracting a plus-minus pair
2533 irrespective of overflow issues.
2535 (A +- B) - A -> +- B
2537 (CST +- A) +- CST -> CST +- A
2538 (A +- CST) +- CST -> A +- CST
2541 A - (A +- B) -> -+ B
2542 A +- (B +- A) -> +- B
2543 CST +- (CST +- A) -> CST +- A
2544 CST +- (A +- CST) -> CST +- A
2546 (T)(P + A) - (T)P -> (T)A
2548 via commutating the addition and contracting operations to zero
2549 by reassociation. */
2551 if (TREE_CODE (rhs1) == SSA_NAME)
2553 gimple def_stmt = SSA_NAME_DEF_STMT (rhs1);
2554 if (is_gimple_assign (def_stmt) && can_propagate_from (def_stmt))
2556 enum tree_code def_code = gimple_assign_rhs_code (def_stmt);
2557 if (def_code == PLUS_EXPR
2558 || def_code == MINUS_EXPR)
2560 tree def_rhs1 = gimple_assign_rhs1 (def_stmt);
2561 tree def_rhs2 = gimple_assign_rhs2 (def_stmt);
2562 if (operand_equal_p (def_rhs1, rhs2, 0)
2563 && code == MINUS_EXPR)
2565 /* (A +- B) - A -> +- B. */
2566 code = ((def_code == PLUS_EXPR)
2567 ? TREE_CODE (def_rhs2) : NEGATE_EXPR);
2570 gimple_assign_set_rhs_with_ops (gsi, code, rhs1, NULL_TREE);
2571 gcc_assert (gsi_stmt (*gsi) == stmt);
2572 gimple_set_modified (stmt, true);
2574 else if (operand_equal_p (def_rhs2, rhs2, 0)
2575 && code != def_code)
2577 /* (A +- B) -+ B -> A. */
2578 code = TREE_CODE (def_rhs1);
2581 gimple_assign_set_rhs_with_ops (gsi, code, rhs1, NULL_TREE);
2582 gcc_assert (gsi_stmt (*gsi) == stmt);
2583 gimple_set_modified (stmt, true);
2585 else if (CONSTANT_CLASS_P (rhs2)
2586 && CONSTANT_CLASS_P (def_rhs1))
2588 /* (CST +- A) +- CST -> CST +- A. */
2589 tree cst = fold_binary (code, TREE_TYPE (rhs1),
2591 if (cst && !TREE_OVERFLOW (cst))
2594 gimple_assign_set_rhs_code (stmt, code);
2596 gimple_assign_set_rhs1 (stmt, rhs1);
2598 gimple_assign_set_rhs2 (stmt, rhs2);
2599 gimple_set_modified (stmt, true);
2602 else if (CONSTANT_CLASS_P (rhs2)
2603 && CONSTANT_CLASS_P (def_rhs2))
2605 /* (A +- CST) +- CST -> A +- CST. */
2606 enum tree_code mix = (code == def_code)
2607 ? PLUS_EXPR : MINUS_EXPR;
2608 tree cst = fold_binary (mix, TREE_TYPE (rhs1),
2610 if (cst && !TREE_OVERFLOW (cst))
2613 gimple_assign_set_rhs_code (stmt, code);
2615 gimple_assign_set_rhs1 (stmt, rhs1);
2617 gimple_assign_set_rhs2 (stmt, rhs2);
2618 gimple_set_modified (stmt, true);
2622 else if (def_code == BIT_NOT_EXPR && code == PLUS_EXPR)
2624 tree def_rhs1 = gimple_assign_rhs1 (def_stmt);
2625 if (operand_equal_p (def_rhs1, rhs2, 0))
2628 rhs1 = build_all_ones_cst (TREE_TYPE (rhs2));
2630 code = TREE_CODE (rhs1);
2631 gimple_assign_set_rhs_with_ops (gsi, code, rhs1, NULL_TREE);
2632 gcc_assert (gsi_stmt (*gsi) == stmt);
2633 gimple_set_modified (stmt, true);
2635 else if ((TREE_CODE (TREE_TYPE (rhs2)) != COMPLEX_TYPE
2636 && integer_onep (rhs2))
2637 || (TREE_CODE (rhs2) == COMPLEX_CST
2638 && integer_onep (TREE_REALPART (rhs2))
2639 && integer_onep (TREE_IMAGPART (rhs2))))
2645 gimple_assign_set_rhs_with_ops (gsi, code, rhs1, NULL_TREE);
2646 gcc_assert (gsi_stmt (*gsi) == stmt);
2647 gimple_set_modified (stmt, true);
2650 else if (CONVERT_EXPR_CODE_P (def_code) && code == MINUS_EXPR
2651 && TREE_CODE (rhs2) == SSA_NAME)
2653 /* (T)(ptr + adj) - (T)ptr -> (T)adj. */
2654 gimple def_stmt2 = SSA_NAME_DEF_STMT (rhs2);
2655 if (TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME
2656 && is_gimple_assign (def_stmt2)
2657 && can_propagate_from (def_stmt2)
2658 && CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt2))
2659 && TREE_CODE (gimple_assign_rhs1 (def_stmt2)) == SSA_NAME)
2661 /* Now we have (T)A - (T)ptr. */
2662 tree ptr = gimple_assign_rhs1 (def_stmt2);
2663 def_stmt2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (def_stmt));
2664 if (is_gimple_assign (def_stmt2)
2665 && gimple_assign_rhs_code (def_stmt2) == POINTER_PLUS_EXPR
2666 && gimple_assign_rhs1 (def_stmt2) == ptr)
2668 /* And finally (T)(ptr + X) - (T)ptr. */
2669 tree adj = gimple_assign_rhs2 (def_stmt2);
2670 /* If the conversion of the pointer adjustment to the
2671 final type requires a sign- or zero-extension we
2672 have to punt - it is not defined which one is
2674 if (TYPE_PRECISION (TREE_TYPE (rhs1))
2675 <= TYPE_PRECISION (TREE_TYPE (adj))
2676 || (TREE_CODE (adj) == INTEGER_CST
2677 && tree_int_cst_sign_bit (adj) == 0))
2679 if (useless_type_conversion_p (TREE_TYPE (rhs1),
2682 code = TREE_CODE (adj);
2691 gimple_assign_set_rhs_with_ops (gsi, code, rhs1,
2693 gcc_assert (gsi_stmt (*gsi) == stmt);
2694 gimple_set_modified (stmt, true);
2702 if (rhs2 && TREE_CODE (rhs2) == SSA_NAME)
2704 gimple def_stmt = SSA_NAME_DEF_STMT (rhs2);
2705 if (is_gimple_assign (def_stmt) && can_propagate_from (def_stmt))
2707 enum tree_code def_code = gimple_assign_rhs_code (def_stmt);
2708 if (def_code == PLUS_EXPR
2709 || def_code == MINUS_EXPR)
2711 tree def_rhs1 = gimple_assign_rhs1 (def_stmt);
2712 tree def_rhs2 = gimple_assign_rhs2 (def_stmt);
2713 if (operand_equal_p (def_rhs1, rhs1, 0)
2714 && code == MINUS_EXPR)
2716 /* A - (A +- B) -> -+ B. */
2717 code = ((def_code == PLUS_EXPR)
2718 ? NEGATE_EXPR : TREE_CODE (def_rhs2));
2721 gimple_assign_set_rhs_with_ops (gsi, code, rhs1, NULL_TREE);
2722 gcc_assert (gsi_stmt (*gsi) == stmt);
2723 gimple_set_modified (stmt, true);
2725 else if (operand_equal_p (def_rhs2, rhs1, 0)
2726 && code != def_code)
2728 /* A +- (B +- A) -> +- B. */
2729 code = ((code == PLUS_EXPR)
2730 ? TREE_CODE (def_rhs1) : NEGATE_EXPR);
2733 gimple_assign_set_rhs_with_ops (gsi, code, rhs1, NULL_TREE);
2734 gcc_assert (gsi_stmt (*gsi) == stmt);
2735 gimple_set_modified (stmt, true);
2737 else if (CONSTANT_CLASS_P (rhs1)
2738 && CONSTANT_CLASS_P (def_rhs1))
2740 /* CST +- (CST +- A) -> CST +- A. */
2741 tree cst = fold_binary (code, TREE_TYPE (rhs2),
2743 if (cst && !TREE_OVERFLOW (cst))
2745 code = (code == def_code ? PLUS_EXPR : MINUS_EXPR);
2746 gimple_assign_set_rhs_code (stmt, code);
2748 gimple_assign_set_rhs1 (stmt, rhs1);
2750 gimple_assign_set_rhs2 (stmt, rhs2);
2751 gimple_set_modified (stmt, true);
2754 else if (CONSTANT_CLASS_P (rhs1)
2755 && CONSTANT_CLASS_P (def_rhs2))
2757 /* CST +- (A +- CST) -> CST +- A. */
2758 tree cst = fold_binary (def_code == code
2759 ? PLUS_EXPR : MINUS_EXPR,
2762 if (cst && !TREE_OVERFLOW (cst))
2765 gimple_assign_set_rhs1 (stmt, rhs1);
2767 gimple_assign_set_rhs2 (stmt, rhs2);
2768 gimple_set_modified (stmt, true);
2772 else if (def_code == BIT_NOT_EXPR)
2774 tree def_rhs1 = gimple_assign_rhs1 (def_stmt);
2775 if (code == PLUS_EXPR
2776 && operand_equal_p (def_rhs1, rhs1, 0))
2779 rhs1 = build_all_ones_cst (TREE_TYPE (rhs1));
2781 code = TREE_CODE (rhs1);
2782 gimple_assign_set_rhs_with_ops (gsi, code, rhs1, NULL_TREE);
2783 gcc_assert (gsi_stmt (*gsi) == stmt);
2784 gimple_set_modified (stmt, true);
2791 if (gimple_modified_p (stmt))
2793 fold_stmt_inplace (gsi);
2795 if (maybe_clean_or_replace_eh_stmt (stmt, stmt)
2796 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
2803 /* Associate operands of a POINTER_PLUS_EXPR assignmen at *GSI. Returns
2804 true if anything changed, false otherwise. */
2807 associate_pointerplus (gimple_stmt_iterator *gsi)
2809 gimple stmt = gsi_stmt (*gsi);
2811 tree ptr, rhs, algn;
2814 tem = (sizetype) ptr;
2818 and produce the simpler and easier to analyze with respect to alignment
2819 ... = ptr & ~algn; */
2820 ptr = gimple_assign_rhs1 (stmt);
2821 rhs = gimple_assign_rhs2 (stmt);
2822 if (TREE_CODE (rhs) != SSA_NAME)
2824 def_stmt = SSA_NAME_DEF_STMT (rhs);
2825 if (!is_gimple_assign (def_stmt)
2826 || gimple_assign_rhs_code (def_stmt) != NEGATE_EXPR)
2828 rhs = gimple_assign_rhs1 (def_stmt);
2829 if (TREE_CODE (rhs) != SSA_NAME)
2831 def_stmt = SSA_NAME_DEF_STMT (rhs);
2832 if (!is_gimple_assign (def_stmt)
2833 || gimple_assign_rhs_code (def_stmt) != BIT_AND_EXPR)
2835 rhs = gimple_assign_rhs1 (def_stmt);
2836 algn = gimple_assign_rhs2 (def_stmt);
2837 if (TREE_CODE (rhs) != SSA_NAME
2838 || TREE_CODE (algn) != INTEGER_CST)
2840 def_stmt = SSA_NAME_DEF_STMT (rhs);
2841 if (!is_gimple_assign (def_stmt)
2842 || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
2844 if (gimple_assign_rhs1 (def_stmt) != ptr)
2847 algn = double_int_to_tree (TREE_TYPE (ptr), ~tree_to_double_int (algn));
2848 gimple_assign_set_rhs_with_ops (gsi, BIT_AND_EXPR, ptr, algn);
2849 fold_stmt_inplace (gsi);
2855 /* Combine two conversions in a row for the second conversion at *GSI.
2856 Returns 1 if there were any changes made, 2 if cfg-cleanup needs to
2857 run. Else it returns 0. */
2860 combine_conversions (gimple_stmt_iterator *gsi)
2862 gimple stmt = gsi_stmt (*gsi);
2865 enum tree_code code = gimple_assign_rhs_code (stmt);
2866 enum tree_code code2;
2868 gcc_checking_assert (CONVERT_EXPR_CODE_P (code)
2869 || code == FLOAT_EXPR
2870 || code == FIX_TRUNC_EXPR);
2872 lhs = gimple_assign_lhs (stmt);
2873 op0 = gimple_assign_rhs1 (stmt);
2874 if (useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (op0)))
2876 gimple_assign_set_rhs_code (stmt, TREE_CODE (op0));
2880 if (TREE_CODE (op0) != SSA_NAME)
2883 def_stmt = SSA_NAME_DEF_STMT (op0);
2884 if (!is_gimple_assign (def_stmt))
2887 code2 = gimple_assign_rhs_code (def_stmt);
2889 if (CONVERT_EXPR_CODE_P (code2) || code2 == FLOAT_EXPR)
2891 tree defop0 = gimple_assign_rhs1 (def_stmt);
2892 tree type = TREE_TYPE (lhs);
2893 tree inside_type = TREE_TYPE (defop0);
2894 tree inter_type = TREE_TYPE (op0);
2895 int inside_int = INTEGRAL_TYPE_P (inside_type);
2896 int inside_ptr = POINTER_TYPE_P (inside_type);
2897 int inside_float = FLOAT_TYPE_P (inside_type);
2898 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
2899 unsigned int inside_prec = TYPE_PRECISION (inside_type);
2900 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
2901 int inter_int = INTEGRAL_TYPE_P (inter_type);
2902 int inter_ptr = POINTER_TYPE_P (inter_type);
2903 int inter_float = FLOAT_TYPE_P (inter_type);
2904 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
2905 unsigned int inter_prec = TYPE_PRECISION (inter_type);
2906 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
2907 int final_int = INTEGRAL_TYPE_P (type);
2908 int final_ptr = POINTER_TYPE_P (type);
2909 int final_float = FLOAT_TYPE_P (type);
2910 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
2911 unsigned int final_prec = TYPE_PRECISION (type);
2912 int final_unsignedp = TYPE_UNSIGNED (type);
2914 /* Don't propagate ssa names that occur in abnormal phis. */
2915 if (TREE_CODE (defop0) == SSA_NAME
2916 && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (defop0))
2919 /* In addition to the cases of two conversions in a row
2920 handled below, if we are converting something to its own
2921 type via an object of identical or wider precision, neither
2922 conversion is needed. */
2923 if (useless_type_conversion_p (type, inside_type)
2924 && (((inter_int || inter_ptr) && final_int)
2925 || (inter_float && final_float))
2926 && inter_prec >= final_prec)
2928 gimple_assign_set_rhs1 (stmt, unshare_expr (defop0));
2929 gimple_assign_set_rhs_code (stmt, TREE_CODE (defop0));
2931 return remove_prop_source_from_use (op0) ? 2 : 1;
2934 /* Likewise, if the intermediate and initial types are either both
2935 float or both integer, we don't need the middle conversion if the
2936 former is wider than the latter and doesn't change the signedness
2937 (for integers). Avoid this if the final type is a pointer since
2938 then we sometimes need the middle conversion. Likewise if the
2939 final type has a precision not equal to the size of its mode. */
2940 if (((inter_int && inside_int)
2941 || (inter_float && inside_float)
2942 || (inter_vec && inside_vec))
2943 && inter_prec >= inside_prec
2944 && (inter_float || inter_vec
2945 || inter_unsignedp == inside_unsignedp)
2946 && ! (final_prec != GET_MODE_PRECISION (TYPE_MODE (type))
2947 && TYPE_MODE (type) == TYPE_MODE (inter_type))
2949 && (! final_vec || inter_prec == inside_prec))
2951 gimple_assign_set_rhs1 (stmt, defop0);
2953 return remove_prop_source_from_use (op0) ? 2 : 1;
2956 /* If we have a sign-extension of a zero-extended value, we can
2957 replace that by a single zero-extension. Likewise if the
2958 final conversion does not change precision we can drop the
2959 intermediate conversion. */
2960 if (inside_int && inter_int && final_int
2961 && ((inside_prec < inter_prec && inter_prec < final_prec
2962 && inside_unsignedp && !inter_unsignedp)
2963 || final_prec == inter_prec))
2965 gimple_assign_set_rhs1 (stmt, defop0);
2967 return remove_prop_source_from_use (op0) ? 2 : 1;
2970 /* Two conversions in a row are not needed unless:
2971 - some conversion is floating-point (overstrict for now), or
2972 - some conversion is a vector (overstrict for now), or
2973 - the intermediate type is narrower than both initial and
2975 - the intermediate type and innermost type differ in signedness,
2976 and the outermost type is wider than the intermediate, or
2977 - the initial type is a pointer type and the precisions of the
2978 intermediate and final types differ, or
2979 - the final type is a pointer type and the precisions of the
2980 initial and intermediate types differ. */
2981 if (! inside_float && ! inter_float && ! final_float
2982 && ! inside_vec && ! inter_vec && ! final_vec
2983 && (inter_prec >= inside_prec || inter_prec >= final_prec)
2984 && ! (inside_int && inter_int
2985 && inter_unsignedp != inside_unsignedp
2986 && inter_prec < final_prec)
2987 && ((inter_unsignedp && inter_prec > inside_prec)
2988 == (final_unsignedp && final_prec > inter_prec))
2989 && ! (inside_ptr && inter_prec != final_prec)
2990 && ! (final_ptr && inside_prec != inter_prec)
2991 && ! (final_prec != GET_MODE_PRECISION (TYPE_MODE (type))
2992 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
2994 gimple_assign_set_rhs1 (stmt, defop0);
2996 return remove_prop_source_from_use (op0) ? 2 : 1;
2999 /* A truncation to an unsigned type should be canonicalized as
3000 bitwise and of a mask. */
3001 if (final_int && inter_int && inside_int
3002 && final_prec == inside_prec
3003 && final_prec > inter_prec
3007 tem = fold_build2 (BIT_AND_EXPR, inside_type,
3010 (inside_type, double_int::mask (inter_prec)));
3011 if (!useless_type_conversion_p (type, inside_type))
3013 tem = force_gimple_operand_gsi (gsi, tem, true, NULL_TREE, true,
3015 gimple_assign_set_rhs1 (stmt, tem);
3018 gimple_assign_set_rhs_from_tree (gsi, tem);
3019 update_stmt (gsi_stmt (*gsi));
3023 /* If we are converting an integer to a floating-point that can
3024 represent it exactly and back to an integer, we can skip the
3025 floating-point conversion. */
3026 if (inside_int && inter_float && final_int &&
3027 (unsigned) significand_size (TYPE_MODE (inter_type))
3028 >= inside_prec - !inside_unsignedp)
3030 if (useless_type_conversion_p (type, inside_type))
3032 gimple_assign_set_rhs1 (stmt, unshare_expr (defop0));
3033 gimple_assign_set_rhs_code (stmt, TREE_CODE (defop0));
3035 return remove_prop_source_from_use (op0) ? 2 : 1;
3039 gimple_assign_set_rhs1 (stmt, defop0);
3040 gimple_assign_set_rhs_code (stmt, CONVERT_EXPR);
3042 return remove_prop_source_from_use (op0) ? 2 : 1;
3050 /* Combine VIEW_CONVERT_EXPRs with their defining statement. */
3053 simplify_vce (gimple_stmt_iterator *gsi)
3055 gimple stmt = gsi_stmt (*gsi);
3056 tree type = TREE_TYPE (gimple_assign_lhs (stmt));
3058 /* Drop useless VIEW_CONVERT_EXPRs. */
3059 tree op = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
3060 if (useless_type_conversion_p (type, TREE_TYPE (op)))
3062 gimple_assign_set_rhs1 (stmt, op);
3067 if (TREE_CODE (op) != SSA_NAME)
3070 gimple def_stmt = SSA_NAME_DEF_STMT (op);
3071 if (!is_gimple_assign (def_stmt))
3074 tree def_op = gimple_assign_rhs1 (def_stmt);
3075 switch (gimple_assign_rhs_code (def_stmt))
3078 /* Strip integral conversions that do not change the precision. */
3079 if ((INTEGRAL_TYPE_P (TREE_TYPE (op))
3080 || POINTER_TYPE_P (TREE_TYPE (op)))
3081 && (INTEGRAL_TYPE_P (TREE_TYPE (def_op))
3082 || POINTER_TYPE_P (TREE_TYPE (def_op)))
3083 && (TYPE_PRECISION (TREE_TYPE (op))
3084 == TYPE_PRECISION (TREE_TYPE (def_op))))
3086 TREE_OPERAND (gimple_assign_rhs1 (stmt), 0) = def_op;
3092 case VIEW_CONVERT_EXPR:
3093 /* Series of VIEW_CONVERT_EXPRs on register operands can
3095 if (TREE_CODE (TREE_OPERAND (def_op, 0)) == SSA_NAME)
3097 if (useless_type_conversion_p (type,
3098 TREE_TYPE (TREE_OPERAND (def_op, 0))))
3099 gimple_assign_set_rhs1 (stmt, TREE_OPERAND (def_op, 0));
3101 TREE_OPERAND (gimple_assign_rhs1 (stmt), 0)
3102 = TREE_OPERAND (def_op, 0);
3113 /* Combine an element access with a shuffle. Returns true if there were
3114 any changes made, else it returns false. */
3117 simplify_bitfield_ref (gimple_stmt_iterator *gsi)
3119 gimple stmt = gsi_stmt (*gsi);
3121 tree op, op0, op1, op2;
3123 unsigned idx, n, size;
3124 enum tree_code code;
3126 op = gimple_assign_rhs1 (stmt);
3127 gcc_checking_assert (TREE_CODE (op) == BIT_FIELD_REF);
3129 op0 = TREE_OPERAND (op, 0);
3130 if (TREE_CODE (op0) != SSA_NAME
3131 || TREE_CODE (TREE_TYPE (op0)) != VECTOR_TYPE)
3134 def_stmt = get_prop_source_stmt (op0, false, NULL);
3135 if (!def_stmt || !can_propagate_from (def_stmt))
3138 op1 = TREE_OPERAND (op, 1);
3139 op2 = TREE_OPERAND (op, 2);
3140 code = gimple_assign_rhs_code (def_stmt);
3142 if (code == CONSTRUCTOR)
3144 tree tem = fold_ternary (BIT_FIELD_REF, TREE_TYPE (op),
3145 gimple_assign_rhs1 (def_stmt), op1, op2);
3146 if (!tem || !valid_gimple_rhs_p (tem))
3148 gimple_assign_set_rhs_from_tree (gsi, tem);
3149 update_stmt (gsi_stmt (*gsi));
3153 elem_type = TREE_TYPE (TREE_TYPE (op0));
3154 if (TREE_TYPE (op) != elem_type)
3157 size = TREE_INT_CST_LOW (TYPE_SIZE (elem_type));
3158 n = TREE_INT_CST_LOW (op1) / size;
3161 idx = TREE_INT_CST_LOW (op2) / size;
3163 if (code == VEC_PERM_EXPR)
3165 tree p, m, index, tem;
3167 m = gimple_assign_rhs3 (def_stmt);
3168 if (TREE_CODE (m) != VECTOR_CST)
3170 nelts = VECTOR_CST_NELTS (m);
3171 idx = TREE_INT_CST_LOW (VECTOR_CST_ELT (m, idx));
3175 p = gimple_assign_rhs1 (def_stmt);
3179 p = gimple_assign_rhs2 (def_stmt);
3182 index = build_int_cst (TREE_TYPE (TREE_TYPE (m)), idx * size);
3183 tem = build3 (BIT_FIELD_REF, TREE_TYPE (op),
3184 unshare_expr (p), op1, index);
3185 gimple_assign_set_rhs1 (stmt, tem);
3187 update_stmt (gsi_stmt (*gsi));
3194 /* Determine whether applying the 2 permutations (mask1 then mask2)
3195 gives back one of the input. */
3198 is_combined_permutation_identity (tree mask1, tree mask2)
3201 unsigned int nelts, i, j;
3202 bool maybe_identity1 = true;
3203 bool maybe_identity2 = true;
3205 gcc_checking_assert (TREE_CODE (mask1) == VECTOR_CST
3206 && TREE_CODE (mask2) == VECTOR_CST);
3207 mask = fold_ternary (VEC_PERM_EXPR, TREE_TYPE (mask1), mask1, mask1, mask2);
3208 gcc_assert (TREE_CODE (mask) == VECTOR_CST);
3210 nelts = VECTOR_CST_NELTS (mask);
3211 for (i = 0; i < nelts; i++)
3213 tree val = VECTOR_CST_ELT (mask, i);
3214 gcc_assert (TREE_CODE (val) == INTEGER_CST);
3215 j = TREE_INT_CST_LOW (val) & (2 * nelts - 1);
3217 maybe_identity2 = false;
3218 else if (j == i + nelts)
3219 maybe_identity1 = false;
3223 return maybe_identity1 ? 1 : maybe_identity2 ? 2 : 0;
3226 /* Combine a shuffle with its arguments. Returns 1 if there were any
3227 changes made, 2 if cfg-cleanup needs to run. Else it returns 0. */
3230 simplify_permutation (gimple_stmt_iterator *gsi)
3232 gimple stmt = gsi_stmt (*gsi);
3234 tree op0, op1, op2, op3, arg0, arg1;
3235 enum tree_code code;
3236 bool single_use_op0 = false;
3238 gcc_checking_assert (gimple_assign_rhs_code (stmt) == VEC_PERM_EXPR);
3240 op0 = gimple_assign_rhs1 (stmt);
3241 op1 = gimple_assign_rhs2 (stmt);
3242 op2 = gimple_assign_rhs3 (stmt);
3244 if (TREE_CODE (op2) != VECTOR_CST)
3247 if (TREE_CODE (op0) == VECTOR_CST)
3252 else if (TREE_CODE (op0) == SSA_NAME)
3254 def_stmt = get_prop_source_stmt (op0, false, &single_use_op0);
3255 if (!def_stmt || !can_propagate_from (def_stmt))
3258 code = gimple_assign_rhs_code (def_stmt);
3259 arg0 = gimple_assign_rhs1 (def_stmt);
3264 /* Two consecutive shuffles. */
3265 if (code == VEC_PERM_EXPR)
3272 op3 = gimple_assign_rhs3 (def_stmt);
3273 if (TREE_CODE (op3) != VECTOR_CST)
3275 ident = is_combined_permutation_identity (op3, op2);
3278 orig = (ident == 1) ? gimple_assign_rhs1 (def_stmt)
3279 : gimple_assign_rhs2 (def_stmt);
3280 gimple_assign_set_rhs1 (stmt, unshare_expr (orig));
3281 gimple_assign_set_rhs_code (stmt, TREE_CODE (orig));
3282 gimple_set_num_ops (stmt, 2);
3284 return remove_prop_source_from_use (op0) ? 2 : 1;
3287 /* Shuffle of a constructor. */
3288 else if (code == CONSTRUCTOR || code == VECTOR_CST)
3294 if (TREE_CODE (op0) == SSA_NAME && !single_use_op0)
3297 if (TREE_CODE (op1) == VECTOR_CST)
3299 else if (TREE_CODE (op1) == SSA_NAME)
3301 enum tree_code code2;
3303 gimple def_stmt2 = get_prop_source_stmt (op1, true, NULL);
3304 if (!def_stmt2 || !can_propagate_from (def_stmt2))
3307 code2 = gimple_assign_rhs_code (def_stmt2);
3308 if (code2 != CONSTRUCTOR && code2 != VECTOR_CST)
3310 arg1 = gimple_assign_rhs1 (def_stmt2);
3317 /* Already used twice in this statement. */
3318 if (TREE_CODE (op0) == SSA_NAME && num_imm_uses (op0) > 2)
3322 opt = fold_ternary (VEC_PERM_EXPR, TREE_TYPE (op0), arg0, arg1, op2);
3324 || (TREE_CODE (opt) != CONSTRUCTOR && TREE_CODE (opt) != VECTOR_CST))
3326 gimple_assign_set_rhs_from_tree (gsi, opt);
3327 update_stmt (gsi_stmt (*gsi));
3328 if (TREE_CODE (op0) == SSA_NAME)
3329 ret = remove_prop_source_from_use (op0);
3330 if (op0 != op1 && TREE_CODE (op1) == SSA_NAME)
3331 ret |= remove_prop_source_from_use (op1);
3338 /* Recognize a VEC_PERM_EXPR. Returns true if there were any changes. */
3341 simplify_vector_constructor (gimple_stmt_iterator *gsi)
3343 gimple stmt = gsi_stmt (*gsi);
3345 tree op, op2, orig, type, elem_type;
3346 unsigned elem_size, nelts, i;
3347 enum tree_code code;
3348 constructor_elt *elt;
3352 gcc_checking_assert (gimple_assign_rhs_code (stmt) == CONSTRUCTOR);
3354 op = gimple_assign_rhs1 (stmt);
3355 type = TREE_TYPE (op);
3356 gcc_checking_assert (TREE_CODE (type) == VECTOR_TYPE);
3358 nelts = TYPE_VECTOR_SUBPARTS (type);
3359 elem_type = TREE_TYPE (type);
3360 elem_size = TREE_INT_CST_LOW (TYPE_SIZE (elem_type));
3362 sel = XALLOCAVEC (unsigned char, nelts);
3365 FOR_EACH_VEC_SAFE_ELT (CONSTRUCTOR_ELTS (op), i, elt)
3372 if (TREE_CODE (elt->value) != SSA_NAME)
3374 def_stmt = get_prop_source_stmt (elt->value, false, NULL);
3377 code = gimple_assign_rhs_code (def_stmt);
3378 if (code != BIT_FIELD_REF)
3380 op1 = gimple_assign_rhs1 (def_stmt);
3381 ref = TREE_OPERAND (op1, 0);
3389 if (TREE_CODE (ref) != SSA_NAME)
3391 if (!useless_type_conversion_p (type, TREE_TYPE (ref)))
3395 if (TREE_INT_CST_LOW (TREE_OPERAND (op1, 1)) != elem_size)
3397 sel[i] = TREE_INT_CST_LOW (TREE_OPERAND (op1, 2)) / elem_size;
3398 if (sel[i] != i) maybe_ident = false;
3404 gimple_assign_set_rhs_from_tree (gsi, orig);
3407 tree mask_type, *mask_elts;
3409 if (!can_vec_perm_p (TYPE_MODE (type), false, sel))
3412 = build_vector_type (build_nonstandard_integer_type (elem_size, 1),
3414 if (GET_MODE_CLASS (TYPE_MODE (mask_type)) != MODE_VECTOR_INT
3415 || GET_MODE_SIZE (TYPE_MODE (mask_type))
3416 != GET_MODE_SIZE (TYPE_MODE (type)))
3418 mask_elts = XALLOCAVEC (tree, nelts);
3419 for (i = 0; i < nelts; i++)
3420 mask_elts[i] = build_int_cst (TREE_TYPE (mask_type), sel[i]);
3421 op2 = build_vector (mask_type, mask_elts);
3422 gimple_assign_set_rhs_with_ops_1 (gsi, VEC_PERM_EXPR, orig, orig, op2);
3424 update_stmt (gsi_stmt (*gsi));
3428 /* Main entry point for the forward propagation and statement combine
3432 ssa_forward_propagate_and_combine (void)
3435 unsigned int todoflags = 0;
3437 cfg_changed = false;
3439 FOR_EACH_BB_FN (bb, cfun)
3441 gimple_stmt_iterator gsi;
3443 /* Apply forward propagation to all stmts in the basic-block.
3444 Note we update GSI within the loop as necessary. */
3445 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
3447 gimple stmt = gsi_stmt (gsi);
3449 enum tree_code code;
3451 if (!is_gimple_assign (stmt))
3457 lhs = gimple_assign_lhs (stmt);
3458 rhs = gimple_assign_rhs1 (stmt);
3459 code = gimple_assign_rhs_code (stmt);
3460 if (TREE_CODE (lhs) != SSA_NAME
3461 || has_zero_uses (lhs))
3467 /* If this statement sets an SSA_NAME to an address,
3468 try to propagate the address into the uses of the SSA_NAME. */
3469 if (code == ADDR_EXPR
3470 /* Handle pointer conversions on invariant addresses
3471 as well, as this is valid gimple. */
3472 || (CONVERT_EXPR_CODE_P (code)
3473 && TREE_CODE (rhs) == ADDR_EXPR
3474 && POINTER_TYPE_P (TREE_TYPE (lhs))))
3476 tree base = get_base_address (TREE_OPERAND (rhs, 0));
3479 || decl_address_invariant_p (base))
3480 && !stmt_references_abnormal_ssa_name (stmt)
3481 && forward_propagate_addr_expr (lhs, rhs, true))
3483 release_defs (stmt);
3484 gsi_remove (&gsi, true);
3489 else if (code == POINTER_PLUS_EXPR)
3491 tree off = gimple_assign_rhs2 (stmt);
3492 if (TREE_CODE (off) == INTEGER_CST
3493 && can_propagate_from (stmt)
3494 && !simple_iv_increment_p (stmt)
3495 /* ??? Better adjust the interface to that function
3496 instead of building new trees here. */
3497 && forward_propagate_addr_expr
3499 build1_loc (gimple_location (stmt),
3500 ADDR_EXPR, TREE_TYPE (rhs),
3501 fold_build2 (MEM_REF,
3502 TREE_TYPE (TREE_TYPE (rhs)),
3504 fold_convert (ptr_type_node,
3507 release_defs (stmt);
3508 gsi_remove (&gsi, true);
3510 else if (is_gimple_min_invariant (rhs))
3512 /* Make sure to fold &a[0] + off_1 here. */
3513 fold_stmt_inplace (&gsi);
3515 if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
3521 else if (TREE_CODE_CLASS (code) == tcc_comparison)
3523 if (forward_propagate_comparison (&gsi))
3530 /* Combine stmts with the stmts defining their operands.
3531 Note we update GSI within the loop as necessary. */
3532 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
3534 gimple stmt = gsi_stmt (gsi);
3535 bool changed = false;
3537 /* Mark stmt as potentially needing revisiting. */
3538 gimple_set_plf (stmt, GF_PLF_1, false);
3540 switch (gimple_code (stmt))
3544 tree rhs1 = gimple_assign_rhs1 (stmt);
3545 enum tree_code code = gimple_assign_rhs_code (stmt);
3547 if ((code == BIT_NOT_EXPR
3548 || code == NEGATE_EXPR)
3549 && TREE_CODE (rhs1) == SSA_NAME)
3550 changed = simplify_not_neg_expr (&gsi);
3551 else if (code == COND_EXPR
3552 || code == VEC_COND_EXPR)
3554 /* In this case the entire COND_EXPR is in rhs1. */
3555 if (forward_propagate_into_cond (&gsi)
3556 || combine_cond_exprs (&gsi))
3559 stmt = gsi_stmt (gsi);
3562 else if (TREE_CODE_CLASS (code) == tcc_comparison)
3565 did_something = forward_propagate_into_comparison (&gsi);
3566 if (did_something == 2)
3568 changed = did_something != 0;
3570 else if ((code == PLUS_EXPR
3571 || code == BIT_IOR_EXPR
3572 || code == BIT_XOR_EXPR)
3573 && simplify_rotate (&gsi))
3575 else if (code == BIT_AND_EXPR
3576 || code == BIT_IOR_EXPR
3577 || code == BIT_XOR_EXPR)
3578 changed = simplify_bitwise_binary (&gsi);
3579 else if (code == PLUS_EXPR
3580 || code == MINUS_EXPR)
3581 changed = associate_plusminus (&gsi);
3582 else if (code == POINTER_PLUS_EXPR)
3583 changed = associate_pointerplus (&gsi);
3584 else if (CONVERT_EXPR_CODE_P (code)
3585 || code == FLOAT_EXPR
3586 || code == FIX_TRUNC_EXPR)
3588 int did_something = combine_conversions (&gsi);
3589 if (did_something == 2)
3592 /* If we have a narrowing conversion to an integral
3593 type that is fed by a BIT_AND_EXPR, we might be
3594 able to remove the BIT_AND_EXPR if it merely
3595 masks off bits outside the final type (and nothing
3597 if (! did_something)
3599 tree outer_type = TREE_TYPE (gimple_assign_lhs (stmt));
3600 tree inner_type = TREE_TYPE (gimple_assign_rhs1 (stmt));
3601 if (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
3602 && INTEGRAL_TYPE_P (outer_type)
3603 && INTEGRAL_TYPE_P (inner_type)
3604 && (TYPE_PRECISION (outer_type)
3605 <= TYPE_PRECISION (inner_type)))
3606 did_something = simplify_conversion_from_bitmask (&gsi);
3609 changed = did_something != 0;
3611 else if (code == VIEW_CONVERT_EXPR)
3612 changed = simplify_vce (&gsi);
3613 else if (code == VEC_PERM_EXPR)
3615 int did_something = simplify_permutation (&gsi);
3616 if (did_something == 2)
3618 changed = did_something != 0;
3620 else if (code == BIT_FIELD_REF)
3621 changed = simplify_bitfield_ref (&gsi);
3622 else if (code == CONSTRUCTOR
3623 && TREE_CODE (TREE_TYPE (rhs1)) == VECTOR_TYPE)
3624 changed = simplify_vector_constructor (&gsi);
3629 changed = simplify_gimple_switch (stmt);
3635 did_something = forward_propagate_into_gimple_cond (stmt);
3636 if (did_something == 2)
3638 changed = did_something != 0;
3644 tree callee = gimple_call_fndecl (stmt);
3645 if (callee != NULL_TREE
3646 && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
3647 changed = simplify_builtin_call (&gsi, callee);
3656 /* If the stmt changed then re-visit it and the statements
3657 inserted before it. */
3658 for (; !gsi_end_p (gsi); gsi_prev (&gsi))
3659 if (gimple_plf (gsi_stmt (gsi), GF_PLF_1))
3661 if (gsi_end_p (gsi))
3662 gsi = gsi_start_bb (bb);
3668 /* Stmt no longer needs to be revisited. */
3669 gimple_set_plf (stmt, GF_PLF_1, true);
3676 todoflags |= TODO_cleanup_cfg;
3683 gate_forwprop (void)
3685 return flag_tree_forwprop;
3690 const pass_data pass_data_forwprop =
3692 GIMPLE_PASS, /* type */
3693 "forwprop", /* name */
3694 OPTGROUP_NONE, /* optinfo_flags */
3695 true, /* has_gate */
3696 true, /* has_execute */
3697 TV_TREE_FORWPROP, /* tv_id */
3698 ( PROP_cfg | PROP_ssa ), /* properties_required */
3699 0, /* properties_provided */
3700 0, /* properties_destroyed */
3701 0, /* todo_flags_start */
3702 ( TODO_update_ssa | TODO_verify_ssa ), /* todo_flags_finish */
3705 class pass_forwprop : public gimple_opt_pass
3708 pass_forwprop (gcc::context *ctxt)
3709 : gimple_opt_pass (pass_data_forwprop, ctxt)
3712 /* opt_pass methods: */
3713 opt_pass * clone () { return new pass_forwprop (m_ctxt); }
3714 bool gate () { return gate_forwprop (); }
3715 unsigned int execute () { return ssa_forward_propagate_and_combine (); }
3717 }; // class pass_forwprop
3722 make_pass_forwprop (gcc::context *ctxt)
3724 return new pass_forwprop (ctxt);