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"
32 #include "hard-reg-set.h"
35 #include "dominance.h"
37 #include "basic-block.h"
38 #include "gimple-pretty-print.h"
39 #include "tree-ssa-alias.h"
40 #include "internal-fn.h"
41 #include "gimple-fold.h"
43 #include "gimple-expr.h"
47 #include "gimple-iterator.h"
48 #include "gimplify-me.h"
49 #include "gimple-ssa.h"
51 #include "tree-phinodes.h"
52 #include "ssa-iterators.h"
53 #include "stringpool.h"
54 #include "tree-ssanames.h"
57 #include "tree-pass.h"
58 #include "langhooks.h"
60 #include "diagnostic.h"
63 #include "insn-codes.h"
65 #include "tree-ssa-propagate.h"
66 #include "tree-ssa-dom.h"
68 #include "tree-cfgcleanup.h"
69 #include "tree-into-ssa.h"
72 /* This pass propagates the RHS of assignment statements into use
73 sites of the LHS of the assignment. It's basically a specialized
74 form of tree combination. It is hoped all of this can disappear
75 when we have a generalized tree combiner.
77 One class of common cases we handle is forward propagating a single use
78 variable into a COND_EXPR.
82 if (x) goto ... else goto ...
84 Will be transformed into:
87 if (a COND b) goto ... else goto ...
89 Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1).
91 Or (assuming c1 and c2 are constants):
95 if (x EQ/NEQ c2) goto ... else goto ...
97 Will be transformed into:
100 if (a EQ/NEQ (c2 - c1)) goto ... else goto ...
102 Similarly for x = a - c1.
108 if (x) goto ... else goto ...
110 Will be transformed into:
113 if (a == 0) goto ... else goto ...
115 Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1).
116 For these cases, we propagate A into all, possibly more than one,
117 COND_EXPRs that use X.
123 if (x) goto ... else goto ...
125 Will be transformed into:
128 if (a != 0) goto ... else goto ...
130 (Assuming a is an integral type and x is a boolean or x is an
131 integral and a is a boolean.)
133 Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1).
134 For these cases, we propagate A into all, possibly more than one,
135 COND_EXPRs that use X.
137 In addition to eliminating the variable and the statement which assigns
138 a value to the variable, we may be able to later thread the jump without
139 adding insane complexity in the dominator optimizer.
141 Also note these transformations can cascade. We handle this by having
142 a worklist of COND_EXPR statements to examine. As we make a change to
143 a statement, we put it back on the worklist to examine on the next
144 iteration of the main loop.
146 A second class of propagation opportunities arises for ADDR_EXPR
157 ptr = (type1*)&type2var;
160 Will get turned into (if type1 and type2 are the same size
161 and neither have volatile on them):
162 res = VIEW_CONVERT_EXPR<type1>(type2var)
167 ptr2 = ptr + <constant>;
171 ptr2 = &x[constant/elementsize];
176 offset = index * element_size;
177 offset_p = (pointer) offset;
178 ptr2 = ptr + offset_p
180 Will get turned into:
188 Provided that decl has known alignment >= 2, will get turned into
192 We also propagate casts into SWITCH_EXPR and COND_EXPR conditions to
193 allow us to remove the cast and {NOT_EXPR,NEG_EXPR} into a subsequent
196 This will (of course) be extended as other needs arise. */
198 static bool forward_propagate_addr_expr (tree
, tree
, bool);
200 /* Set to true if we delete dead edges during the optimization. */
201 static bool cfg_changed
;
203 static tree
rhs_to_tree (tree type
, gimple stmt
);
205 static bitmap to_purge
;
207 /* Const-and-copy lattice. */
208 static vec
<tree
> lattice
;
210 /* Set the lattice entry for NAME to VAL. */
212 fwprop_set_lattice_val (tree name
, tree val
)
214 if (TREE_CODE (name
) == SSA_NAME
)
216 if (SSA_NAME_VERSION (name
) >= lattice
.length ())
218 lattice
.reserve (num_ssa_names
- lattice
.length ());
219 lattice
.quick_grow_cleared (num_ssa_names
);
221 lattice
[SSA_NAME_VERSION (name
)] = val
;
225 /* Invalidate the lattice entry for NAME, done when releasing SSA names. */
227 fwprop_invalidate_lattice (tree name
)
230 && TREE_CODE (name
) == SSA_NAME
231 && SSA_NAME_VERSION (name
) < lattice
.length ())
232 lattice
[SSA_NAME_VERSION (name
)] = NULL_TREE
;
236 /* Get the statement we can propagate from into NAME skipping
237 trivial copies. Returns the statement which defines the
238 propagation source or NULL_TREE if there is no such one.
239 If SINGLE_USE_ONLY is set considers only sources which have
240 a single use chain up to NAME. If SINGLE_USE_P is non-null,
241 it is set to whether the chain to NAME is a single use chain
242 or not. SINGLE_USE_P is not written to if SINGLE_USE_ONLY is set. */
245 get_prop_source_stmt (tree name
, bool single_use_only
, bool *single_use_p
)
247 bool single_use
= true;
250 gimple def_stmt
= SSA_NAME_DEF_STMT (name
);
252 if (!has_single_use (name
))
259 /* If name is defined by a PHI node or is the default def, bail out. */
260 if (!is_gimple_assign (def_stmt
))
263 /* If def_stmt is a simple copy, continue looking. */
264 if (gimple_assign_rhs_code (def_stmt
) == SSA_NAME
)
265 name
= gimple_assign_rhs1 (def_stmt
);
268 if (!single_use_only
&& single_use_p
)
269 *single_use_p
= single_use
;
276 /* Checks if the destination ssa name in DEF_STMT can be used as
277 propagation source. Returns true if so, otherwise false. */
280 can_propagate_from (gimple def_stmt
)
282 gcc_assert (is_gimple_assign (def_stmt
));
284 /* If the rhs has side-effects we cannot propagate from it. */
285 if (gimple_has_volatile_ops (def_stmt
))
288 /* If the rhs is a load we cannot propagate from it. */
289 if (TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt
)) == tcc_reference
290 || TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt
)) == tcc_declaration
)
293 /* Constants can be always propagated. */
294 if (gimple_assign_single_p (def_stmt
)
295 && is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt
)))
298 /* We cannot propagate ssa names that occur in abnormal phi nodes. */
299 if (stmt_references_abnormal_ssa_name (def_stmt
))
302 /* If the definition is a conversion of a pointer to a function type,
303 then we can not apply optimizations as some targets require
304 function pointers to be canonicalized and in this case this
305 optimization could eliminate a necessary canonicalization. */
306 if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt
)))
308 tree rhs
= gimple_assign_rhs1 (def_stmt
);
309 if (POINTER_TYPE_P (TREE_TYPE (rhs
))
310 && TREE_CODE (TREE_TYPE (TREE_TYPE (rhs
))) == FUNCTION_TYPE
)
317 /* Remove a chain of dead statements starting at the definition of
318 NAME. The chain is linked via the first operand of the defining statements.
319 If NAME was replaced in its only use then this function can be used
320 to clean up dead stmts. The function handles already released SSA
322 Returns true if cleanup-cfg has to run. */
325 remove_prop_source_from_use (tree name
)
327 gimple_stmt_iterator gsi
;
329 bool cfg_changed
= false;
334 if (SSA_NAME_IN_FREE_LIST (name
)
335 || SSA_NAME_IS_DEFAULT_DEF (name
)
336 || !has_zero_uses (name
))
339 stmt
= SSA_NAME_DEF_STMT (name
);
340 if (gimple_code (stmt
) == GIMPLE_PHI
341 || gimple_has_side_effects (stmt
))
344 bb
= gimple_bb (stmt
);
345 gsi
= gsi_for_stmt (stmt
);
346 unlink_stmt_vdef (stmt
);
347 if (gsi_remove (&gsi
, true))
348 bitmap_set_bit (to_purge
, bb
->index
);
349 fwprop_invalidate_lattice (gimple_get_lhs (stmt
));
352 name
= is_gimple_assign (stmt
) ? gimple_assign_rhs1 (stmt
) : NULL_TREE
;
353 } while (name
&& TREE_CODE (name
) == SSA_NAME
);
358 /* Return the rhs of a gassign *STMT in a form of a single tree,
359 converted to type TYPE.
361 This should disappear, but is needed so we can combine expressions and use
362 the fold() interfaces. Long term, we need to develop folding and combine
363 routines that deal with gimple exclusively . */
366 rhs_to_tree (tree type
, gimple stmt
)
368 location_t loc
= gimple_location (stmt
);
369 enum tree_code code
= gimple_assign_rhs_code (stmt
);
370 if (get_gimple_rhs_class (code
) == GIMPLE_TERNARY_RHS
)
371 return fold_build3_loc (loc
, code
, type
, gimple_assign_rhs1 (stmt
),
372 gimple_assign_rhs2 (stmt
),
373 gimple_assign_rhs3 (stmt
));
374 else if (get_gimple_rhs_class (code
) == GIMPLE_BINARY_RHS
)
375 return fold_build2_loc (loc
, code
, type
, gimple_assign_rhs1 (stmt
),
376 gimple_assign_rhs2 (stmt
));
377 else if (get_gimple_rhs_class (code
) == GIMPLE_UNARY_RHS
)
378 return build1 (code
, type
, gimple_assign_rhs1 (stmt
));
379 else if (get_gimple_rhs_class (code
) == GIMPLE_SINGLE_RHS
)
380 return gimple_assign_rhs1 (stmt
);
385 /* Combine OP0 CODE OP1 in the context of a COND_EXPR. Returns
386 the folded result in a form suitable for COND_EXPR_COND or
387 NULL_TREE, if there is no suitable simplified form. If
388 INVARIANT_ONLY is true only gimple_min_invariant results are
389 considered simplified. */
392 combine_cond_expr_cond (gimple stmt
, enum tree_code code
, tree type
,
393 tree op0
, tree op1
, bool invariant_only
)
397 gcc_assert (TREE_CODE_CLASS (code
) == tcc_comparison
);
399 fold_defer_overflow_warnings ();
400 t
= fold_binary_loc (gimple_location (stmt
), code
, type
, op0
, op1
);
403 fold_undefer_overflow_warnings (false, NULL
, 0);
407 /* Require that we got a boolean type out if we put one in. */
408 gcc_assert (TREE_CODE (TREE_TYPE (t
)) == TREE_CODE (type
));
410 /* Canonicalize the combined condition for use in a COND_EXPR. */
411 t
= canonicalize_cond_expr_cond (t
);
413 /* Bail out if we required an invariant but didn't get one. */
414 if (!t
|| (invariant_only
&& !is_gimple_min_invariant (t
)))
416 fold_undefer_overflow_warnings (false, NULL
, 0);
420 fold_undefer_overflow_warnings (!gimple_no_warning_p (stmt
), stmt
, 0);
425 /* Combine the comparison OP0 CODE OP1 at LOC with the defining statements
426 of its operand. Return a new comparison tree or NULL_TREE if there
427 were no simplifying combines. */
430 forward_propagate_into_comparison_1 (gimple stmt
,
431 enum tree_code code
, tree type
,
434 tree tmp
= NULL_TREE
;
435 tree rhs0
= NULL_TREE
, rhs1
= NULL_TREE
;
436 bool single_use0_p
= false, single_use1_p
= false;
438 /* For comparisons use the first operand, that is likely to
439 simplify comparisons against constants. */
440 if (TREE_CODE (op0
) == SSA_NAME
)
442 gimple def_stmt
= get_prop_source_stmt (op0
, false, &single_use0_p
);
443 if (def_stmt
&& can_propagate_from (def_stmt
))
445 enum tree_code def_code
= gimple_assign_rhs_code (def_stmt
);
446 bool invariant_only_p
= !single_use0_p
;
448 rhs0
= rhs_to_tree (TREE_TYPE (op1
), def_stmt
);
450 /* Always combine comparisons or conversions from booleans. */
451 if (TREE_CODE (op1
) == INTEGER_CST
452 && ((CONVERT_EXPR_CODE_P (def_code
)
453 && TREE_CODE (TREE_TYPE (TREE_OPERAND (rhs0
, 0)))
455 || TREE_CODE_CLASS (def_code
) == tcc_comparison
))
456 invariant_only_p
= false;
458 tmp
= combine_cond_expr_cond (stmt
, code
, type
,
459 rhs0
, op1
, invariant_only_p
);
465 /* If that wasn't successful, try the second operand. */
466 if (TREE_CODE (op1
) == SSA_NAME
)
468 gimple def_stmt
= get_prop_source_stmt (op1
, false, &single_use1_p
);
469 if (def_stmt
&& can_propagate_from (def_stmt
))
471 rhs1
= rhs_to_tree (TREE_TYPE (op0
), def_stmt
);
472 tmp
= combine_cond_expr_cond (stmt
, code
, type
,
473 op0
, rhs1
, !single_use1_p
);
479 /* If that wasn't successful either, try both operands. */
480 if (rhs0
!= NULL_TREE
481 && rhs1
!= NULL_TREE
)
482 tmp
= combine_cond_expr_cond (stmt
, code
, type
,
484 !(single_use0_p
&& single_use1_p
));
489 /* Propagate from the ssa name definition statements of the assignment
490 from a comparison at *GSI into the conditional if that simplifies it.
491 Returns 1 if the stmt was modified and 2 if the CFG needs cleanup,
492 otherwise returns 0. */
495 forward_propagate_into_comparison (gimple_stmt_iterator
*gsi
)
497 gimple stmt
= gsi_stmt (*gsi
);
499 bool cfg_changed
= false;
500 tree type
= TREE_TYPE (gimple_assign_lhs (stmt
));
501 tree rhs1
= gimple_assign_rhs1 (stmt
);
502 tree rhs2
= gimple_assign_rhs2 (stmt
);
504 /* Combine the comparison with defining statements. */
505 tmp
= forward_propagate_into_comparison_1 (stmt
,
506 gimple_assign_rhs_code (stmt
),
508 if (tmp
&& useless_type_conversion_p (type
, TREE_TYPE (tmp
)))
510 gimple_assign_set_rhs_from_tree (gsi
, tmp
);
512 update_stmt (gsi_stmt (*gsi
));
514 if (TREE_CODE (rhs1
) == SSA_NAME
)
515 cfg_changed
|= remove_prop_source_from_use (rhs1
);
516 if (TREE_CODE (rhs2
) == SSA_NAME
)
517 cfg_changed
|= remove_prop_source_from_use (rhs2
);
518 return cfg_changed
? 2 : 1;
524 /* Propagate from the ssa name definition statements of COND_EXPR
525 in GIMPLE_COND statement STMT into the conditional if that simplifies it.
526 Returns zero if no statement was changed, one if there were
527 changes and two if cfg_cleanup needs to run.
529 This must be kept in sync with forward_propagate_into_cond. */
532 forward_propagate_into_gimple_cond (gcond
*stmt
)
535 enum tree_code code
= gimple_cond_code (stmt
);
536 bool cfg_changed
= false;
537 tree rhs1
= gimple_cond_lhs (stmt
);
538 tree rhs2
= gimple_cond_rhs (stmt
);
540 /* We can do tree combining on SSA_NAME and comparison expressions. */
541 if (TREE_CODE_CLASS (gimple_cond_code (stmt
)) != tcc_comparison
)
544 tmp
= forward_propagate_into_comparison_1 (stmt
, code
,
549 if (dump_file
&& tmp
)
551 fprintf (dump_file
, " Replaced '");
552 print_gimple_expr (dump_file
, stmt
, 0, 0);
553 fprintf (dump_file
, "' with '");
554 print_generic_expr (dump_file
, tmp
, 0);
555 fprintf (dump_file
, "'\n");
558 gimple_cond_set_condition_from_tree (stmt
, unshare_expr (tmp
));
561 if (TREE_CODE (rhs1
) == SSA_NAME
)
562 cfg_changed
|= remove_prop_source_from_use (rhs1
);
563 if (TREE_CODE (rhs2
) == SSA_NAME
)
564 cfg_changed
|= remove_prop_source_from_use (rhs2
);
565 return (cfg_changed
|| is_gimple_min_invariant (tmp
)) ? 2 : 1;
568 /* Canonicalize _Bool == 0 and _Bool != 1 to _Bool != 0 by swapping edges. */
569 if ((TREE_CODE (TREE_TYPE (rhs1
)) == BOOLEAN_TYPE
570 || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1
))
571 && TYPE_PRECISION (TREE_TYPE (rhs1
)) == 1))
573 && integer_zerop (rhs2
))
575 && integer_onep (rhs2
))))
577 basic_block bb
= gimple_bb (stmt
);
578 gimple_cond_set_code (stmt
, NE_EXPR
);
579 gimple_cond_set_rhs (stmt
, build_zero_cst (TREE_TYPE (rhs1
)));
580 EDGE_SUCC (bb
, 0)->flags
^= (EDGE_TRUE_VALUE
|EDGE_FALSE_VALUE
);
581 EDGE_SUCC (bb
, 1)->flags
^= (EDGE_TRUE_VALUE
|EDGE_FALSE_VALUE
);
589 /* Propagate from the ssa name definition statements of COND_EXPR
590 in the rhs of statement STMT into the conditional if that simplifies it.
591 Returns true zero if the stmt was changed. */
594 forward_propagate_into_cond (gimple_stmt_iterator
*gsi_p
)
596 gimple stmt
= gsi_stmt (*gsi_p
);
597 tree tmp
= NULL_TREE
;
598 tree cond
= gimple_assign_rhs1 (stmt
);
599 enum tree_code code
= gimple_assign_rhs_code (stmt
);
601 /* We can do tree combining on SSA_NAME and comparison expressions. */
602 if (COMPARISON_CLASS_P (cond
))
603 tmp
= forward_propagate_into_comparison_1 (stmt
, TREE_CODE (cond
),
605 TREE_OPERAND (cond
, 0),
606 TREE_OPERAND (cond
, 1));
607 else if (TREE_CODE (cond
) == SSA_NAME
)
609 enum tree_code def_code
;
611 gimple def_stmt
= get_prop_source_stmt (name
, true, NULL
);
612 if (!def_stmt
|| !can_propagate_from (def_stmt
))
615 def_code
= gimple_assign_rhs_code (def_stmt
);
616 if (TREE_CODE_CLASS (def_code
) == tcc_comparison
)
617 tmp
= fold_build2_loc (gimple_location (def_stmt
),
620 gimple_assign_rhs1 (def_stmt
),
621 gimple_assign_rhs2 (def_stmt
));
625 && is_gimple_condexpr (tmp
))
627 if (dump_file
&& tmp
)
629 fprintf (dump_file
, " Replaced '");
630 print_generic_expr (dump_file
, cond
, 0);
631 fprintf (dump_file
, "' with '");
632 print_generic_expr (dump_file
, tmp
, 0);
633 fprintf (dump_file
, "'\n");
636 if ((code
== VEC_COND_EXPR
) ? integer_all_onesp (tmp
)
637 : integer_onep (tmp
))
638 gimple_assign_set_rhs_from_tree (gsi_p
, gimple_assign_rhs2 (stmt
));
639 else if (integer_zerop (tmp
))
640 gimple_assign_set_rhs_from_tree (gsi_p
, gimple_assign_rhs3 (stmt
));
642 gimple_assign_set_rhs1 (stmt
, unshare_expr (tmp
));
643 stmt
= gsi_stmt (*gsi_p
);
652 /* We've just substituted an ADDR_EXPR into stmt. Update all the
653 relevant data structures to match. */
656 tidy_after_forward_propagate_addr (gimple stmt
)
658 /* We may have turned a trapping insn into a non-trapping insn. */
659 if (maybe_clean_or_replace_eh_stmt (stmt
, stmt
))
660 bitmap_set_bit (to_purge
, gimple_bb (stmt
)->index
);
662 if (TREE_CODE (gimple_assign_rhs1 (stmt
)) == ADDR_EXPR
)
663 recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt
));
666 /* NAME is a SSA_NAME representing DEF_RHS which is of the form
667 ADDR_EXPR <whatever>.
669 Try to forward propagate the ADDR_EXPR into the use USE_STMT.
670 Often this will allow for removal of an ADDR_EXPR and INDIRECT_REF
671 node or for recovery of array indexing from pointer arithmetic.
673 Return true if the propagation was successful (the propagation can
674 be not totally successful, yet things may have been changed). */
677 forward_propagate_addr_expr_1 (tree name
, tree def_rhs
,
678 gimple_stmt_iterator
*use_stmt_gsi
,
681 tree lhs
, rhs
, rhs2
, array_ref
;
682 gimple use_stmt
= gsi_stmt (*use_stmt_gsi
);
683 enum tree_code rhs_code
;
686 gcc_assert (TREE_CODE (def_rhs
) == ADDR_EXPR
);
688 lhs
= gimple_assign_lhs (use_stmt
);
689 rhs_code
= gimple_assign_rhs_code (use_stmt
);
690 rhs
= gimple_assign_rhs1 (use_stmt
);
692 /* Do not perform copy-propagation but recurse through copy chains. */
693 if (TREE_CODE (lhs
) == SSA_NAME
694 && rhs_code
== SSA_NAME
)
695 return forward_propagate_addr_expr (lhs
, def_rhs
, single_use_p
);
697 /* The use statement could be a conversion. Recurse to the uses of the
698 lhs as copyprop does not copy through pointer to integer to pointer
699 conversions and FRE does not catch all cases either.
700 Treat the case of a single-use name and
701 a conversion to def_rhs type separate, though. */
702 if (TREE_CODE (lhs
) == SSA_NAME
703 && CONVERT_EXPR_CODE_P (rhs_code
))
705 /* If there is a point in a conversion chain where the types match
706 so we can remove a conversion re-materialize the address here
709 && useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (def_rhs
)))
711 gimple_assign_set_rhs1 (use_stmt
, unshare_expr (def_rhs
));
712 gimple_assign_set_rhs_code (use_stmt
, TREE_CODE (def_rhs
));
716 /* Else recurse if the conversion preserves the address value. */
717 if ((INTEGRAL_TYPE_P (TREE_TYPE (lhs
))
718 || POINTER_TYPE_P (TREE_TYPE (lhs
)))
719 && (TYPE_PRECISION (TREE_TYPE (lhs
))
720 >= TYPE_PRECISION (TREE_TYPE (def_rhs
))))
721 return forward_propagate_addr_expr (lhs
, def_rhs
, single_use_p
);
726 /* If this isn't a conversion chain from this on we only can propagate
727 into compatible pointer contexts. */
728 if (!types_compatible_p (TREE_TYPE (name
), TREE_TYPE (def_rhs
)))
731 /* Propagate through constant pointer adjustments. */
732 if (TREE_CODE (lhs
) == SSA_NAME
733 && rhs_code
== POINTER_PLUS_EXPR
735 && TREE_CODE (gimple_assign_rhs2 (use_stmt
)) == INTEGER_CST
)
738 /* As we come here with non-invariant addresses in def_rhs we need
739 to make sure we can build a valid constant offsetted address
740 for further propagation. Simply rely on fold building that
741 and check after the fact. */
742 new_def_rhs
= fold_build2 (MEM_REF
, TREE_TYPE (TREE_TYPE (rhs
)),
744 fold_convert (ptr_type_node
,
745 gimple_assign_rhs2 (use_stmt
)));
746 if (TREE_CODE (new_def_rhs
) == MEM_REF
747 && !is_gimple_mem_ref_addr (TREE_OPERAND (new_def_rhs
, 0)))
749 new_def_rhs
= build_fold_addr_expr_with_type (new_def_rhs
,
752 /* Recurse. If we could propagate into all uses of lhs do not
753 bother to replace into the current use but just pretend we did. */
754 if (TREE_CODE (new_def_rhs
) == ADDR_EXPR
755 && forward_propagate_addr_expr (lhs
, new_def_rhs
, single_use_p
))
758 if (useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (new_def_rhs
)))
759 gimple_assign_set_rhs_with_ops (use_stmt_gsi
, TREE_CODE (new_def_rhs
),
761 else if (is_gimple_min_invariant (new_def_rhs
))
762 gimple_assign_set_rhs_with_ops (use_stmt_gsi
, NOP_EXPR
, new_def_rhs
);
765 gcc_assert (gsi_stmt (*use_stmt_gsi
) == use_stmt
);
766 update_stmt (use_stmt
);
770 /* Now strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS.
771 ADDR_EXPR will not appear on the LHS. */
772 tree
*lhsp
= gimple_assign_lhs_ptr (use_stmt
);
773 while (handled_component_p (*lhsp
))
774 lhsp
= &TREE_OPERAND (*lhsp
, 0);
777 /* Now see if the LHS node is a MEM_REF using NAME. If so,
778 propagate the ADDR_EXPR into the use of NAME and fold the result. */
779 if (TREE_CODE (lhs
) == MEM_REF
780 && TREE_OPERAND (lhs
, 0) == name
)
783 HOST_WIDE_INT def_rhs_offset
;
784 /* If the address is invariant we can always fold it. */
785 if ((def_rhs_base
= get_addr_base_and_unit_offset (TREE_OPERAND (def_rhs
, 0),
788 offset_int off
= mem_ref_offset (lhs
);
790 off
+= def_rhs_offset
;
791 if (TREE_CODE (def_rhs_base
) == MEM_REF
)
793 off
+= mem_ref_offset (def_rhs_base
);
794 new_ptr
= TREE_OPERAND (def_rhs_base
, 0);
797 new_ptr
= build_fold_addr_expr (def_rhs_base
);
798 TREE_OPERAND (lhs
, 0) = new_ptr
;
799 TREE_OPERAND (lhs
, 1)
800 = wide_int_to_tree (TREE_TYPE (TREE_OPERAND (lhs
, 1)), off
);
801 tidy_after_forward_propagate_addr (use_stmt
);
802 /* Continue propagating into the RHS if this was not the only use. */
806 /* If the LHS is a plain dereference and the value type is the same as
807 that of the pointed-to type of the address we can put the
808 dereferenced address on the LHS preserving the original alias-type. */
809 else if (integer_zerop (TREE_OPERAND (lhs
, 1))
810 && ((gimple_assign_lhs (use_stmt
) == lhs
811 && useless_type_conversion_p
812 (TREE_TYPE (TREE_OPERAND (def_rhs
, 0)),
813 TREE_TYPE (gimple_assign_rhs1 (use_stmt
))))
814 || types_compatible_p (TREE_TYPE (lhs
),
815 TREE_TYPE (TREE_OPERAND (def_rhs
, 0))))
816 /* Don't forward anything into clobber stmts if it would result
817 in the lhs no longer being a MEM_REF. */
818 && (!gimple_clobber_p (use_stmt
)
819 || TREE_CODE (TREE_OPERAND (def_rhs
, 0)) == MEM_REF
))
821 tree
*def_rhs_basep
= &TREE_OPERAND (def_rhs
, 0);
822 tree new_offset
, new_base
, saved
, new_lhs
;
823 while (handled_component_p (*def_rhs_basep
))
824 def_rhs_basep
= &TREE_OPERAND (*def_rhs_basep
, 0);
825 saved
= *def_rhs_basep
;
826 if (TREE_CODE (*def_rhs_basep
) == MEM_REF
)
828 new_base
= TREE_OPERAND (*def_rhs_basep
, 0);
829 new_offset
= fold_convert (TREE_TYPE (TREE_OPERAND (lhs
, 1)),
830 TREE_OPERAND (*def_rhs_basep
, 1));
834 new_base
= build_fold_addr_expr (*def_rhs_basep
);
835 new_offset
= TREE_OPERAND (lhs
, 1);
837 *def_rhs_basep
= build2 (MEM_REF
, TREE_TYPE (*def_rhs_basep
),
838 new_base
, new_offset
);
839 TREE_THIS_VOLATILE (*def_rhs_basep
) = TREE_THIS_VOLATILE (lhs
);
840 TREE_SIDE_EFFECTS (*def_rhs_basep
) = TREE_SIDE_EFFECTS (lhs
);
841 TREE_THIS_NOTRAP (*def_rhs_basep
) = TREE_THIS_NOTRAP (lhs
);
842 new_lhs
= unshare_expr (TREE_OPERAND (def_rhs
, 0));
844 TREE_THIS_VOLATILE (new_lhs
) = TREE_THIS_VOLATILE (lhs
);
845 TREE_SIDE_EFFECTS (new_lhs
) = TREE_SIDE_EFFECTS (lhs
);
846 *def_rhs_basep
= saved
;
847 tidy_after_forward_propagate_addr (use_stmt
);
848 /* Continue propagating into the RHS if this was not the
854 /* We can have a struct assignment dereferencing our name twice.
855 Note that we didn't propagate into the lhs to not falsely
856 claim we did when propagating into the rhs. */
860 /* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR
861 nodes from the RHS. */
862 tree
*rhsp
= gimple_assign_rhs1_ptr (use_stmt
);
863 if (TREE_CODE (*rhsp
) == ADDR_EXPR
)
864 rhsp
= &TREE_OPERAND (*rhsp
, 0);
865 while (handled_component_p (*rhsp
))
866 rhsp
= &TREE_OPERAND (*rhsp
, 0);
869 /* Now see if the RHS node is a MEM_REF using NAME. If so,
870 propagate the ADDR_EXPR into the use of NAME and fold the result. */
871 if (TREE_CODE (rhs
) == MEM_REF
872 && TREE_OPERAND (rhs
, 0) == name
)
875 HOST_WIDE_INT def_rhs_offset
;
876 if ((def_rhs_base
= get_addr_base_and_unit_offset (TREE_OPERAND (def_rhs
, 0),
879 offset_int off
= mem_ref_offset (rhs
);
881 off
+= def_rhs_offset
;
882 if (TREE_CODE (def_rhs_base
) == MEM_REF
)
884 off
+= mem_ref_offset (def_rhs_base
);
885 new_ptr
= TREE_OPERAND (def_rhs_base
, 0);
888 new_ptr
= build_fold_addr_expr (def_rhs_base
);
889 TREE_OPERAND (rhs
, 0) = new_ptr
;
890 TREE_OPERAND (rhs
, 1)
891 = wide_int_to_tree (TREE_TYPE (TREE_OPERAND (rhs
, 1)), off
);
892 fold_stmt_inplace (use_stmt_gsi
);
893 tidy_after_forward_propagate_addr (use_stmt
);
896 /* If the RHS is a plain dereference and the value type is the same as
897 that of the pointed-to type of the address we can put the
898 dereferenced address on the RHS preserving the original alias-type. */
899 else if (integer_zerop (TREE_OPERAND (rhs
, 1))
900 && ((gimple_assign_rhs1 (use_stmt
) == rhs
901 && useless_type_conversion_p
902 (TREE_TYPE (gimple_assign_lhs (use_stmt
)),
903 TREE_TYPE (TREE_OPERAND (def_rhs
, 0))))
904 || types_compatible_p (TREE_TYPE (rhs
),
905 TREE_TYPE (TREE_OPERAND (def_rhs
, 0)))))
907 tree
*def_rhs_basep
= &TREE_OPERAND (def_rhs
, 0);
908 tree new_offset
, new_base
, saved
, new_rhs
;
909 while (handled_component_p (*def_rhs_basep
))
910 def_rhs_basep
= &TREE_OPERAND (*def_rhs_basep
, 0);
911 saved
= *def_rhs_basep
;
912 if (TREE_CODE (*def_rhs_basep
) == MEM_REF
)
914 new_base
= TREE_OPERAND (*def_rhs_basep
, 0);
915 new_offset
= fold_convert (TREE_TYPE (TREE_OPERAND (rhs
, 1)),
916 TREE_OPERAND (*def_rhs_basep
, 1));
920 new_base
= build_fold_addr_expr (*def_rhs_basep
);
921 new_offset
= TREE_OPERAND (rhs
, 1);
923 *def_rhs_basep
= build2 (MEM_REF
, TREE_TYPE (*def_rhs_basep
),
924 new_base
, new_offset
);
925 TREE_THIS_VOLATILE (*def_rhs_basep
) = TREE_THIS_VOLATILE (rhs
);
926 TREE_SIDE_EFFECTS (*def_rhs_basep
) = TREE_SIDE_EFFECTS (rhs
);
927 TREE_THIS_NOTRAP (*def_rhs_basep
) = TREE_THIS_NOTRAP (rhs
);
928 new_rhs
= unshare_expr (TREE_OPERAND (def_rhs
, 0));
930 TREE_THIS_VOLATILE (new_rhs
) = TREE_THIS_VOLATILE (rhs
);
931 TREE_SIDE_EFFECTS (new_rhs
) = TREE_SIDE_EFFECTS (rhs
);
932 *def_rhs_basep
= saved
;
933 fold_stmt_inplace (use_stmt_gsi
);
934 tidy_after_forward_propagate_addr (use_stmt
);
939 /* If the use of the ADDR_EXPR is not a POINTER_PLUS_EXPR, there
941 if (gimple_assign_rhs_code (use_stmt
) != POINTER_PLUS_EXPR
942 || gimple_assign_rhs1 (use_stmt
) != name
)
945 /* The remaining cases are all for turning pointer arithmetic into
946 array indexing. They only apply when we have the address of
947 element zero in an array. If that is not the case then there
949 array_ref
= TREE_OPERAND (def_rhs
, 0);
950 if ((TREE_CODE (array_ref
) != ARRAY_REF
951 || TREE_CODE (TREE_TYPE (TREE_OPERAND (array_ref
, 0))) != ARRAY_TYPE
952 || TREE_CODE (TREE_OPERAND (array_ref
, 1)) != INTEGER_CST
)
953 && TREE_CODE (TREE_TYPE (array_ref
)) != ARRAY_TYPE
)
956 rhs2
= gimple_assign_rhs2 (use_stmt
);
957 /* Optimize &x[C1] p+ C2 to &x p+ C3 with C3 = C1 * element_size + C2. */
958 if (TREE_CODE (rhs2
) == INTEGER_CST
)
960 tree new_rhs
= build1_loc (gimple_location (use_stmt
),
961 ADDR_EXPR
, TREE_TYPE (def_rhs
),
962 fold_build2 (MEM_REF
,
963 TREE_TYPE (TREE_TYPE (def_rhs
)),
964 unshare_expr (def_rhs
),
965 fold_convert (ptr_type_node
,
967 gimple_assign_set_rhs_from_tree (use_stmt_gsi
, new_rhs
);
968 use_stmt
= gsi_stmt (*use_stmt_gsi
);
969 update_stmt (use_stmt
);
970 tidy_after_forward_propagate_addr (use_stmt
);
977 /* STMT is a statement of the form SSA_NAME = ADDR_EXPR <whatever>.
979 Try to forward propagate the ADDR_EXPR into all uses of the SSA_NAME.
980 Often this will allow for removal of an ADDR_EXPR and INDIRECT_REF
981 node or for recovery of array indexing from pointer arithmetic.
983 PARENT_SINGLE_USE_P tells if, when in a recursive invocation, NAME was
984 the single use in the previous invocation. Pass true when calling
987 Returns true, if all uses have been propagated into. */
990 forward_propagate_addr_expr (tree name
, tree rhs
, bool parent_single_use_p
)
992 imm_use_iterator iter
;
995 bool single_use_p
= parent_single_use_p
&& has_single_use (name
);
997 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, name
)
1002 /* If the use is not in a simple assignment statement, then
1003 there is nothing we can do. */
1004 if (!is_gimple_assign (use_stmt
))
1006 if (!is_gimple_debug (use_stmt
))
1011 gimple_stmt_iterator gsi
= gsi_for_stmt (use_stmt
);
1012 result
= forward_propagate_addr_expr_1 (name
, rhs
, &gsi
,
1014 /* If the use has moved to a different statement adjust
1015 the update machinery for the old statement too. */
1016 if (use_stmt
!= gsi_stmt (gsi
))
1018 update_stmt (use_stmt
);
1019 use_stmt
= gsi_stmt (gsi
);
1021 update_stmt (use_stmt
);
1024 /* Remove intermediate now unused copy and conversion chains. */
1025 use_rhs
= gimple_assign_rhs1 (use_stmt
);
1027 && TREE_CODE (gimple_assign_lhs (use_stmt
)) == SSA_NAME
1028 && TREE_CODE (use_rhs
) == SSA_NAME
1029 && has_zero_uses (gimple_assign_lhs (use_stmt
)))
1031 gimple_stmt_iterator gsi
= gsi_for_stmt (use_stmt
);
1032 fwprop_invalidate_lattice (gimple_get_lhs (use_stmt
));
1033 release_defs (use_stmt
);
1034 gsi_remove (&gsi
, true);
1038 return all
&& has_zero_uses (name
);
1042 /* Helper function for simplify_gimple_switch. Remove case labels that
1043 have values outside the range of the new type. */
1046 simplify_gimple_switch_label_vec (gswitch
*stmt
, tree index_type
)
1048 unsigned int branch_num
= gimple_switch_num_labels (stmt
);
1049 auto_vec
<tree
> labels (branch_num
);
1050 unsigned int i
, len
;
1052 /* Collect the existing case labels in a VEC, and preprocess it as if
1053 we are gimplifying a GENERIC SWITCH_EXPR. */
1054 for (i
= 1; i
< branch_num
; i
++)
1055 labels
.quick_push (gimple_switch_label (stmt
, i
));
1056 preprocess_case_label_vec_for_gimple (labels
, index_type
, NULL
);
1058 /* If any labels were removed, replace the existing case labels
1059 in the GIMPLE_SWITCH statement with the correct ones.
1060 Note that the type updates were done in-place on the case labels,
1061 so we only have to replace the case labels in the GIMPLE_SWITCH
1062 if the number of labels changed. */
1063 len
= labels
.length ();
1064 if (len
< branch_num
- 1)
1066 bitmap target_blocks
;
1070 /* Corner case: *all* case labels have been removed as being
1071 out-of-range for INDEX_TYPE. Push one label and let the
1072 CFG cleanups deal with this further. */
1077 label
= CASE_LABEL (gimple_switch_default_label (stmt
));
1078 elt
= build_case_label (build_int_cst (index_type
, 0), NULL
, label
);
1079 labels
.quick_push (elt
);
1083 for (i
= 0; i
< labels
.length (); i
++)
1084 gimple_switch_set_label (stmt
, i
+ 1, labels
[i
]);
1085 for (i
++ ; i
< branch_num
; i
++)
1086 gimple_switch_set_label (stmt
, i
, NULL_TREE
);
1087 gimple_switch_set_num_labels (stmt
, len
+ 1);
1089 /* Cleanup any edges that are now dead. */
1090 target_blocks
= BITMAP_ALLOC (NULL
);
1091 for (i
= 0; i
< gimple_switch_num_labels (stmt
); i
++)
1093 tree elt
= gimple_switch_label (stmt
, i
);
1094 basic_block target
= label_to_block (CASE_LABEL (elt
));
1095 bitmap_set_bit (target_blocks
, target
->index
);
1097 for (ei
= ei_start (gimple_bb (stmt
)->succs
); (e
= ei_safe_edge (ei
)); )
1099 if (! bitmap_bit_p (target_blocks
, e
->dest
->index
))
1103 free_dominance_info (CDI_DOMINATORS
);
1108 BITMAP_FREE (target_blocks
);
1112 /* STMT is a SWITCH_EXPR for which we attempt to find equivalent forms of
1113 the condition which we may be able to optimize better. */
1116 simplify_gimple_switch (gswitch
*stmt
)
1118 /* The optimization that we really care about is removing unnecessary
1119 casts. That will let us do much better in propagating the inferred
1120 constant at the switch target. */
1121 tree cond
= gimple_switch_index (stmt
);
1122 if (TREE_CODE (cond
) == SSA_NAME
)
1124 gimple def_stmt
= SSA_NAME_DEF_STMT (cond
);
1125 if (gimple_assign_cast_p (def_stmt
))
1127 tree def
= gimple_assign_rhs1 (def_stmt
);
1128 if (TREE_CODE (def
) != SSA_NAME
)
1131 /* If we have an extension or sign-change that preserves the
1132 values we check against then we can copy the source value into
1134 tree ti
= TREE_TYPE (def
);
1135 if (INTEGRAL_TYPE_P (ti
)
1136 && TYPE_PRECISION (ti
) <= TYPE_PRECISION (TREE_TYPE (cond
)))
1138 size_t n
= gimple_switch_num_labels (stmt
);
1139 tree min
= NULL_TREE
, max
= NULL_TREE
;
1142 min
= CASE_LOW (gimple_switch_label (stmt
, 1));
1143 if (CASE_HIGH (gimple_switch_label (stmt
, n
- 1)))
1144 max
= CASE_HIGH (gimple_switch_label (stmt
, n
- 1));
1146 max
= CASE_LOW (gimple_switch_label (stmt
, n
- 1));
1148 if ((!min
|| int_fits_type_p (min
, ti
))
1149 && (!max
|| int_fits_type_p (max
, ti
)))
1151 gimple_switch_set_index (stmt
, def
);
1152 simplify_gimple_switch_label_vec (stmt
, ti
);
1163 /* For pointers p2 and p1 return p2 - p1 if the
1164 difference is known and constant, otherwise return NULL. */
1167 constant_pointer_difference (tree p1
, tree p2
)
1170 #define CPD_ITERATIONS 5
1171 tree exps
[2][CPD_ITERATIONS
];
1172 tree offs
[2][CPD_ITERATIONS
];
1175 for (i
= 0; i
< 2; i
++)
1177 tree p
= i
? p1
: p2
;
1178 tree off
= size_zero_node
;
1180 enum tree_code code
;
1182 /* For each of p1 and p2 we need to iterate at least
1183 twice, to handle ADDR_EXPR directly in p1/p2,
1184 SSA_NAME with ADDR_EXPR or POINTER_PLUS_EXPR etc.
1185 on definition's stmt RHS. Iterate a few extra times. */
1189 if (!POINTER_TYPE_P (TREE_TYPE (p
)))
1191 if (TREE_CODE (p
) == ADDR_EXPR
)
1193 tree q
= TREE_OPERAND (p
, 0);
1194 HOST_WIDE_INT offset
;
1195 tree base
= get_addr_base_and_unit_offset (q
, &offset
);
1200 off
= size_binop (PLUS_EXPR
, off
, size_int (offset
));
1202 if (TREE_CODE (q
) == MEM_REF
1203 && TREE_CODE (TREE_OPERAND (q
, 0)) == SSA_NAME
)
1205 p
= TREE_OPERAND (q
, 0);
1206 off
= size_binop (PLUS_EXPR
, off
,
1207 wide_int_to_tree (sizetype
,
1208 mem_ref_offset (q
)));
1217 if (TREE_CODE (p
) != SSA_NAME
)
1221 if (j
== CPD_ITERATIONS
)
1223 stmt
= SSA_NAME_DEF_STMT (p
);
1224 if (!is_gimple_assign (stmt
) || gimple_assign_lhs (stmt
) != p
)
1226 code
= gimple_assign_rhs_code (stmt
);
1227 if (code
== POINTER_PLUS_EXPR
)
1229 if (TREE_CODE (gimple_assign_rhs2 (stmt
)) != INTEGER_CST
)
1231 off
= size_binop (PLUS_EXPR
, off
, gimple_assign_rhs2 (stmt
));
1232 p
= gimple_assign_rhs1 (stmt
);
1234 else if (code
== ADDR_EXPR
|| CONVERT_EXPR_CODE_P (code
))
1235 p
= gimple_assign_rhs1 (stmt
);
1243 for (i
= 0; i
< cnt
[0]; i
++)
1244 for (j
= 0; j
< cnt
[1]; j
++)
1245 if (exps
[0][i
] == exps
[1][j
])
1246 return size_binop (MINUS_EXPR
, offs
[0][i
], offs
[1][j
]);
1251 /* *GSI_P is a GIMPLE_CALL to a builtin function.
1253 memcpy (p, "abcd", 4);
1254 memset (p + 4, ' ', 3);
1256 memcpy (p, "abcd ", 7);
1257 call if the latter can be stored by pieces during expansion. */
1260 simplify_builtin_call (gimple_stmt_iterator
*gsi_p
, tree callee2
)
1262 gimple stmt1
, stmt2
= gsi_stmt (*gsi_p
);
1263 tree vuse
= gimple_vuse (stmt2
);
1266 stmt1
= SSA_NAME_DEF_STMT (vuse
);
1268 switch (DECL_FUNCTION_CODE (callee2
))
1270 case BUILT_IN_MEMSET
:
1271 if (gimple_call_num_args (stmt2
) != 3
1272 || gimple_call_lhs (stmt2
)
1274 || BITS_PER_UNIT
!= 8)
1279 tree ptr1
, src1
, str1
, off1
, len1
, lhs1
;
1280 tree ptr2
= gimple_call_arg (stmt2
, 0);
1281 tree val2
= gimple_call_arg (stmt2
, 1);
1282 tree len2
= gimple_call_arg (stmt2
, 2);
1283 tree diff
, vdef
, new_str_cst
;
1285 unsigned int ptr1_align
;
1286 unsigned HOST_WIDE_INT src_len
;
1288 use_operand_p use_p
;
1290 if (!tree_fits_shwi_p (val2
)
1291 || !tree_fits_uhwi_p (len2
)
1292 || compare_tree_int (len2
, 1024) == 1)
1294 if (is_gimple_call (stmt1
))
1296 /* If first stmt is a call, it needs to be memcpy
1297 or mempcpy, with string literal as second argument and
1299 callee1
= gimple_call_fndecl (stmt1
);
1300 if (callee1
== NULL_TREE
1301 || DECL_BUILT_IN_CLASS (callee1
) != BUILT_IN_NORMAL
1302 || gimple_call_num_args (stmt1
) != 3)
1304 if (DECL_FUNCTION_CODE (callee1
) != BUILT_IN_MEMCPY
1305 && DECL_FUNCTION_CODE (callee1
) != BUILT_IN_MEMPCPY
)
1307 ptr1
= gimple_call_arg (stmt1
, 0);
1308 src1
= gimple_call_arg (stmt1
, 1);
1309 len1
= gimple_call_arg (stmt1
, 2);
1310 lhs1
= gimple_call_lhs (stmt1
);
1311 if (!tree_fits_uhwi_p (len1
))
1313 str1
= string_constant (src1
, &off1
);
1314 if (str1
== NULL_TREE
)
1316 if (!tree_fits_uhwi_p (off1
)
1317 || compare_tree_int (off1
, TREE_STRING_LENGTH (str1
) - 1) > 0
1318 || compare_tree_int (len1
, TREE_STRING_LENGTH (str1
)
1319 - tree_to_uhwi (off1
)) > 0
1320 || TREE_CODE (TREE_TYPE (str1
)) != ARRAY_TYPE
1321 || TYPE_MODE (TREE_TYPE (TREE_TYPE (str1
)))
1322 != TYPE_MODE (char_type_node
))
1325 else if (gimple_assign_single_p (stmt1
))
1327 /* Otherwise look for length 1 memcpy optimized into
1329 ptr1
= gimple_assign_lhs (stmt1
);
1330 src1
= gimple_assign_rhs1 (stmt1
);
1331 if (TREE_CODE (ptr1
) != MEM_REF
1332 || TYPE_MODE (TREE_TYPE (ptr1
)) != TYPE_MODE (char_type_node
)
1333 || !tree_fits_shwi_p (src1
))
1335 ptr1
= build_fold_addr_expr (ptr1
);
1336 callee1
= NULL_TREE
;
1337 len1
= size_one_node
;
1339 off1
= size_zero_node
;
1345 diff
= constant_pointer_difference (ptr1
, ptr2
);
1346 if (diff
== NULL
&& lhs1
!= NULL
)
1348 diff
= constant_pointer_difference (lhs1
, ptr2
);
1349 if (DECL_FUNCTION_CODE (callee1
) == BUILT_IN_MEMPCPY
1351 diff
= size_binop (PLUS_EXPR
, diff
,
1352 fold_convert (sizetype
, len1
));
1354 /* If the difference between the second and first destination pointer
1355 is not constant, or is bigger than memcpy length, bail out. */
1357 || !tree_fits_uhwi_p (diff
)
1358 || tree_int_cst_lt (len1
, diff
)
1359 || compare_tree_int (diff
, 1024) == 1)
1362 /* Use maximum of difference plus memset length and memcpy length
1363 as the new memcpy length, if it is too big, bail out. */
1364 src_len
= tree_to_uhwi (diff
);
1365 src_len
+= tree_to_uhwi (len2
);
1366 if (src_len
< tree_to_uhwi (len1
))
1367 src_len
= tree_to_uhwi (len1
);
1371 /* If mempcpy value is used elsewhere, bail out, as mempcpy
1372 with bigger length will return different result. */
1373 if (lhs1
!= NULL_TREE
1374 && DECL_FUNCTION_CODE (callee1
) == BUILT_IN_MEMPCPY
1375 && (TREE_CODE (lhs1
) != SSA_NAME
1376 || !single_imm_use (lhs1
, &use_p
, &use_stmt
)
1377 || use_stmt
!= stmt2
))
1380 /* If anything reads memory in between memcpy and memset
1381 call, the modified memcpy call might change it. */
1382 vdef
= gimple_vdef (stmt1
);
1384 && (!single_imm_use (vdef
, &use_p
, &use_stmt
)
1385 || use_stmt
!= stmt2
))
1388 ptr1_align
= get_pointer_alignment (ptr1
);
1389 /* Construct the new source string literal. */
1390 src_buf
= XALLOCAVEC (char, src_len
+ 1);
1393 TREE_STRING_POINTER (str1
) + tree_to_uhwi (off1
),
1394 tree_to_uhwi (len1
));
1396 src_buf
[0] = tree_to_shwi (src1
);
1397 memset (src_buf
+ tree_to_uhwi (diff
),
1398 tree_to_shwi (val2
), tree_to_uhwi (len2
));
1399 src_buf
[src_len
] = '\0';
1400 /* Neither builtin_strncpy_read_str nor builtin_memcpy_read_str
1401 handle embedded '\0's. */
1402 if (strlen (src_buf
) != src_len
)
1404 rtl_profile_for_bb (gimple_bb (stmt2
));
1405 /* If the new memcpy wouldn't be emitted by storing the literal
1406 by pieces, this optimization might enlarge .rodata too much,
1407 as commonly used string literals couldn't be shared any
1409 if (!can_store_by_pieces (src_len
,
1410 builtin_strncpy_read_str
,
1411 src_buf
, ptr1_align
, false))
1414 new_str_cst
= build_string_literal (src_len
, src_buf
);
1417 /* If STMT1 is a mem{,p}cpy call, adjust it and remove
1419 if (lhs1
&& DECL_FUNCTION_CODE (callee1
) == BUILT_IN_MEMPCPY
)
1420 gimple_call_set_lhs (stmt1
, NULL_TREE
);
1421 gimple_call_set_arg (stmt1
, 1, new_str_cst
);
1422 gimple_call_set_arg (stmt1
, 2,
1423 build_int_cst (TREE_TYPE (len1
), src_len
));
1424 update_stmt (stmt1
);
1425 unlink_stmt_vdef (stmt2
);
1426 gsi_remove (gsi_p
, true);
1427 fwprop_invalidate_lattice (gimple_get_lhs (stmt2
));
1428 release_defs (stmt2
);
1429 if (lhs1
&& DECL_FUNCTION_CODE (callee1
) == BUILT_IN_MEMPCPY
)
1431 fwprop_invalidate_lattice (lhs1
);
1432 release_ssa_name (lhs1
);
1438 /* Otherwise, if STMT1 is length 1 memcpy optimized into
1439 assignment, remove STMT1 and change memset call into
1441 gimple_stmt_iterator gsi
= gsi_for_stmt (stmt1
);
1443 if (!is_gimple_val (ptr1
))
1444 ptr1
= force_gimple_operand_gsi (gsi_p
, ptr1
, true, NULL_TREE
,
1445 true, GSI_SAME_STMT
);
1446 gimple_call_set_fndecl (stmt2
,
1447 builtin_decl_explicit (BUILT_IN_MEMCPY
));
1448 gimple_call_set_arg (stmt2
, 0, ptr1
);
1449 gimple_call_set_arg (stmt2
, 1, new_str_cst
);
1450 gimple_call_set_arg (stmt2
, 2,
1451 build_int_cst (TREE_TYPE (len2
), src_len
));
1452 unlink_stmt_vdef (stmt1
);
1453 gsi_remove (&gsi
, true);
1454 fwprop_invalidate_lattice (gimple_get_lhs (stmt1
));
1455 release_defs (stmt1
);
1456 update_stmt (stmt2
);
1467 /* Given a ssa_name in NAME see if it was defined by an assignment and
1468 set CODE to be the code and ARG1 to the first operand on the rhs and ARG2
1469 to the second operand on the rhs. */
1472 defcodefor_name (tree name
, enum tree_code
*code
, tree
*arg1
, tree
*arg2
)
1475 enum tree_code code1
;
1479 enum gimple_rhs_class grhs_class
;
1481 code1
= TREE_CODE (name
);
1484 grhs_class
= get_gimple_rhs_class (code1
);
1486 if (code1
== SSA_NAME
)
1488 def
= SSA_NAME_DEF_STMT (name
);
1490 if (def
&& is_gimple_assign (def
)
1491 && can_propagate_from (def
))
1493 code1
= gimple_assign_rhs_code (def
);
1494 arg11
= gimple_assign_rhs1 (def
);
1495 arg21
= gimple_assign_rhs2 (def
);
1496 arg31
= gimple_assign_rhs2 (def
);
1499 else if (grhs_class
== GIMPLE_TERNARY_RHS
1500 || GIMPLE_BINARY_RHS
1502 || GIMPLE_SINGLE_RHS
)
1503 extract_ops_from_tree_1 (name
, &code1
, &arg11
, &arg21
, &arg31
);
1509 /* Ignore arg3 currently. */
1513 /* Recognize rotation patterns. Return true if a transformation
1514 applied, otherwise return false.
1516 We are looking for X with unsigned type T with bitsize B, OP being
1517 +, | or ^, some type T2 wider than T and
1518 (X << CNT1) OP (X >> CNT2) iff CNT1 + CNT2 == B
1519 ((T) ((T2) X << CNT1)) OP ((T) ((T2) X >> CNT2)) iff CNT1 + CNT2 == B
1520 (X << Y) OP (X >> (B - Y))
1521 (X << (int) Y) OP (X >> (int) (B - Y))
1522 ((T) ((T2) X << Y)) OP ((T) ((T2) X >> (B - Y)))
1523 ((T) ((T2) X << (int) Y)) OP ((T) ((T2) X >> (int) (B - Y)))
1524 (X << Y) | (X >> ((-Y) & (B - 1)))
1525 (X << (int) Y) | (X >> (int) ((-Y) & (B - 1)))
1526 ((T) ((T2) X << Y)) | ((T) ((T2) X >> ((-Y) & (B - 1))))
1527 ((T) ((T2) X << (int) Y)) | ((T) ((T2) X >> (int) ((-Y) & (B - 1))))
1529 and transform these into:
1533 Note, in the patterns with T2 type, the type of OP operands
1534 might be even a signed type, but should have precision B. */
1537 simplify_rotate (gimple_stmt_iterator
*gsi
)
1539 gimple stmt
= gsi_stmt (*gsi
);
1540 tree arg
[2], rtype
, rotcnt
= NULL_TREE
;
1541 tree def_arg1
[2], def_arg2
[2];
1542 enum tree_code def_code
[2];
1545 bool swapped_p
= false;
1548 arg
[0] = gimple_assign_rhs1 (stmt
);
1549 arg
[1] = gimple_assign_rhs2 (stmt
);
1550 rtype
= TREE_TYPE (arg
[0]);
1552 /* Only create rotates in complete modes. Other cases are not
1553 expanded properly. */
1554 if (!INTEGRAL_TYPE_P (rtype
)
1555 || TYPE_PRECISION (rtype
) != GET_MODE_PRECISION (TYPE_MODE (rtype
)))
1558 for (i
= 0; i
< 2; i
++)
1559 defcodefor_name (arg
[i
], &def_code
[i
], &def_arg1
[i
], &def_arg2
[i
]);
1561 /* Look through narrowing conversions. */
1562 if (CONVERT_EXPR_CODE_P (def_code
[0])
1563 && CONVERT_EXPR_CODE_P (def_code
[1])
1564 && INTEGRAL_TYPE_P (TREE_TYPE (def_arg1
[0]))
1565 && INTEGRAL_TYPE_P (TREE_TYPE (def_arg1
[1]))
1566 && TYPE_PRECISION (TREE_TYPE (def_arg1
[0]))
1567 == TYPE_PRECISION (TREE_TYPE (def_arg1
[1]))
1568 && TYPE_PRECISION (TREE_TYPE (def_arg1
[0])) > TYPE_PRECISION (rtype
)
1569 && has_single_use (arg
[0])
1570 && has_single_use (arg
[1]))
1572 for (i
= 0; i
< 2; i
++)
1574 arg
[i
] = def_arg1
[i
];
1575 defcodefor_name (arg
[i
], &def_code
[i
], &def_arg1
[i
], &def_arg2
[i
]);
1579 /* One operand has to be LSHIFT_EXPR and one RSHIFT_EXPR. */
1580 for (i
= 0; i
< 2; i
++)
1581 if (def_code
[i
] != LSHIFT_EXPR
&& def_code
[i
] != RSHIFT_EXPR
)
1583 else if (!has_single_use (arg
[i
]))
1585 if (def_code
[0] == def_code
[1])
1588 /* If we've looked through narrowing conversions before, look through
1589 widening conversions from unsigned type with the same precision
1591 if (TYPE_PRECISION (TREE_TYPE (def_arg1
[0])) != TYPE_PRECISION (rtype
))
1592 for (i
= 0; i
< 2; i
++)
1595 enum tree_code code
;
1596 defcodefor_name (def_arg1
[i
], &code
, &tem
, NULL
);
1597 if (!CONVERT_EXPR_CODE_P (code
)
1598 || !INTEGRAL_TYPE_P (TREE_TYPE (tem
))
1599 || TYPE_PRECISION (TREE_TYPE (tem
)) != TYPE_PRECISION (rtype
))
1603 /* Both shifts have to use the same first operand. */
1604 if (TREE_CODE (def_arg1
[0]) != SSA_NAME
|| def_arg1
[0] != def_arg1
[1])
1606 if (!TYPE_UNSIGNED (TREE_TYPE (def_arg1
[0])))
1609 /* CNT1 + CNT2 == B case above. */
1610 if (tree_fits_uhwi_p (def_arg2
[0])
1611 && tree_fits_uhwi_p (def_arg2
[1])
1612 && tree_to_uhwi (def_arg2
[0])
1613 + tree_to_uhwi (def_arg2
[1]) == TYPE_PRECISION (rtype
))
1614 rotcnt
= def_arg2
[0];
1615 else if (TREE_CODE (def_arg2
[0]) != SSA_NAME
1616 || TREE_CODE (def_arg2
[1]) != SSA_NAME
)
1620 tree cdef_arg1
[2], cdef_arg2
[2], def_arg2_alt
[2];
1621 enum tree_code cdef_code
[2];
1622 /* Look through conversion of the shift count argument.
1623 The C/C++ FE cast any shift count argument to integer_type_node.
1624 The only problem might be if the shift count type maximum value
1625 is equal or smaller than number of bits in rtype. */
1626 for (i
= 0; i
< 2; i
++)
1628 def_arg2_alt
[i
] = def_arg2
[i
];
1629 defcodefor_name (def_arg2
[i
], &cdef_code
[i
],
1630 &cdef_arg1
[i
], &cdef_arg2
[i
]);
1631 if (CONVERT_EXPR_CODE_P (cdef_code
[i
])
1632 && INTEGRAL_TYPE_P (TREE_TYPE (cdef_arg1
[i
]))
1633 && TYPE_PRECISION (TREE_TYPE (cdef_arg1
[i
]))
1634 > floor_log2 (TYPE_PRECISION (rtype
))
1635 && TYPE_PRECISION (TREE_TYPE (cdef_arg1
[i
]))
1636 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (cdef_arg1
[i
]))))
1638 def_arg2_alt
[i
] = cdef_arg1
[i
];
1639 defcodefor_name (def_arg2_alt
[i
], &cdef_code
[i
],
1640 &cdef_arg1
[i
], &cdef_arg2
[i
]);
1643 for (i
= 0; i
< 2; i
++)
1644 /* Check for one shift count being Y and the other B - Y,
1645 with optional casts. */
1646 if (cdef_code
[i
] == MINUS_EXPR
1647 && tree_fits_shwi_p (cdef_arg1
[i
])
1648 && tree_to_shwi (cdef_arg1
[i
]) == TYPE_PRECISION (rtype
)
1649 && TREE_CODE (cdef_arg2
[i
]) == SSA_NAME
)
1652 enum tree_code code
;
1654 if (cdef_arg2
[i
] == def_arg2
[1 - i
]
1655 || cdef_arg2
[i
] == def_arg2_alt
[1 - i
])
1657 rotcnt
= cdef_arg2
[i
];
1660 defcodefor_name (cdef_arg2
[i
], &code
, &tem
, NULL
);
1661 if (CONVERT_EXPR_CODE_P (code
)
1662 && INTEGRAL_TYPE_P (TREE_TYPE (tem
))
1663 && TYPE_PRECISION (TREE_TYPE (tem
))
1664 > floor_log2 (TYPE_PRECISION (rtype
))
1665 && TYPE_PRECISION (TREE_TYPE (tem
))
1666 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem
)))
1667 && (tem
== def_arg2
[1 - i
]
1668 || tem
== def_arg2_alt
[1 - i
]))
1674 /* The above sequence isn't safe for Y being 0,
1675 because then one of the shifts triggers undefined behavior.
1676 This alternative is safe even for rotation count of 0.
1677 One shift count is Y and the other (-Y) & (B - 1). */
1678 else if (cdef_code
[i
] == BIT_AND_EXPR
1679 && tree_fits_shwi_p (cdef_arg2
[i
])
1680 && tree_to_shwi (cdef_arg2
[i
])
1681 == TYPE_PRECISION (rtype
) - 1
1682 && TREE_CODE (cdef_arg1
[i
]) == SSA_NAME
1683 && gimple_assign_rhs_code (stmt
) == BIT_IOR_EXPR
)
1686 enum tree_code code
;
1688 defcodefor_name (cdef_arg1
[i
], &code
, &tem
, NULL
);
1689 if (CONVERT_EXPR_CODE_P (code
)
1690 && INTEGRAL_TYPE_P (TREE_TYPE (tem
))
1691 && TYPE_PRECISION (TREE_TYPE (tem
))
1692 > floor_log2 (TYPE_PRECISION (rtype
))
1693 && TYPE_PRECISION (TREE_TYPE (tem
))
1694 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem
))))
1695 defcodefor_name (tem
, &code
, &tem
, NULL
);
1697 if (code
== NEGATE_EXPR
)
1699 if (tem
== def_arg2
[1 - i
] || tem
== def_arg2_alt
[1 - i
])
1704 defcodefor_name (tem
, &code
, &tem
, NULL
);
1705 if (CONVERT_EXPR_CODE_P (code
)
1706 && INTEGRAL_TYPE_P (TREE_TYPE (tem
))
1707 && TYPE_PRECISION (TREE_TYPE (tem
))
1708 > floor_log2 (TYPE_PRECISION (rtype
))
1709 && TYPE_PRECISION (TREE_TYPE (tem
))
1710 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (tem
)))
1711 && (tem
== def_arg2
[1 - i
]
1712 || tem
== def_arg2_alt
[1 - i
]))
1719 if (rotcnt
== NULL_TREE
)
1724 if (!useless_type_conversion_p (TREE_TYPE (def_arg2
[0]),
1725 TREE_TYPE (rotcnt
)))
1727 g
= gimple_build_assign (make_ssa_name (TREE_TYPE (def_arg2
[0])),
1729 gsi_insert_before (gsi
, g
, GSI_SAME_STMT
);
1730 rotcnt
= gimple_assign_lhs (g
);
1732 lhs
= gimple_assign_lhs (stmt
);
1733 if (!useless_type_conversion_p (rtype
, TREE_TYPE (def_arg1
[0])))
1734 lhs
= make_ssa_name (TREE_TYPE (def_arg1
[0]));
1735 g
= gimple_build_assign (lhs
,
1736 ((def_code
[0] == LSHIFT_EXPR
) ^ swapped_p
)
1737 ? LROTATE_EXPR
: RROTATE_EXPR
, def_arg1
[0], rotcnt
);
1738 if (!useless_type_conversion_p (rtype
, TREE_TYPE (def_arg1
[0])))
1740 gsi_insert_before (gsi
, g
, GSI_SAME_STMT
);
1741 g
= gimple_build_assign (gimple_assign_lhs (stmt
), NOP_EXPR
, lhs
);
1743 gsi_replace (gsi
, g
, false);
1747 /* Combine an element access with a shuffle. Returns true if there were
1748 any changes made, else it returns false. */
1751 simplify_bitfield_ref (gimple_stmt_iterator
*gsi
)
1753 gimple stmt
= gsi_stmt (*gsi
);
1755 tree op
, op0
, op1
, op2
;
1757 unsigned idx
, n
, size
;
1758 enum tree_code code
;
1760 op
= gimple_assign_rhs1 (stmt
);
1761 gcc_checking_assert (TREE_CODE (op
) == BIT_FIELD_REF
);
1763 op0
= TREE_OPERAND (op
, 0);
1764 if (TREE_CODE (op0
) != SSA_NAME
1765 || TREE_CODE (TREE_TYPE (op0
)) != VECTOR_TYPE
)
1768 def_stmt
= get_prop_source_stmt (op0
, false, NULL
);
1769 if (!def_stmt
|| !can_propagate_from (def_stmt
))
1772 op1
= TREE_OPERAND (op
, 1);
1773 op2
= TREE_OPERAND (op
, 2);
1774 code
= gimple_assign_rhs_code (def_stmt
);
1776 if (code
== CONSTRUCTOR
)
1778 tree tem
= fold_ternary (BIT_FIELD_REF
, TREE_TYPE (op
),
1779 gimple_assign_rhs1 (def_stmt
), op1
, op2
);
1780 if (!tem
|| !valid_gimple_rhs_p (tem
))
1782 gimple_assign_set_rhs_from_tree (gsi
, tem
);
1783 update_stmt (gsi_stmt (*gsi
));
1787 elem_type
= TREE_TYPE (TREE_TYPE (op0
));
1788 if (TREE_TYPE (op
) != elem_type
)
1791 size
= TREE_INT_CST_LOW (TYPE_SIZE (elem_type
));
1792 n
= TREE_INT_CST_LOW (op1
) / size
;
1795 idx
= TREE_INT_CST_LOW (op2
) / size
;
1797 if (code
== VEC_PERM_EXPR
)
1799 tree p
, m
, index
, tem
;
1801 m
= gimple_assign_rhs3 (def_stmt
);
1802 if (TREE_CODE (m
) != VECTOR_CST
)
1804 nelts
= VECTOR_CST_NELTS (m
);
1805 idx
= TREE_INT_CST_LOW (VECTOR_CST_ELT (m
, idx
));
1809 p
= gimple_assign_rhs1 (def_stmt
);
1813 p
= gimple_assign_rhs2 (def_stmt
);
1816 index
= build_int_cst (TREE_TYPE (TREE_TYPE (m
)), idx
* size
);
1817 tem
= build3 (BIT_FIELD_REF
, TREE_TYPE (op
),
1818 unshare_expr (p
), op1
, index
);
1819 gimple_assign_set_rhs1 (stmt
, tem
);
1821 update_stmt (gsi_stmt (*gsi
));
1828 /* Determine whether applying the 2 permutations (mask1 then mask2)
1829 gives back one of the input. */
1832 is_combined_permutation_identity (tree mask1
, tree mask2
)
1835 unsigned int nelts
, i
, j
;
1836 bool maybe_identity1
= true;
1837 bool maybe_identity2
= true;
1839 gcc_checking_assert (TREE_CODE (mask1
) == VECTOR_CST
1840 && TREE_CODE (mask2
) == VECTOR_CST
);
1841 mask
= fold_ternary (VEC_PERM_EXPR
, TREE_TYPE (mask1
), mask1
, mask1
, mask2
);
1842 gcc_assert (TREE_CODE (mask
) == VECTOR_CST
);
1844 nelts
= VECTOR_CST_NELTS (mask
);
1845 for (i
= 0; i
< nelts
; i
++)
1847 tree val
= VECTOR_CST_ELT (mask
, i
);
1848 gcc_assert (TREE_CODE (val
) == INTEGER_CST
);
1849 j
= TREE_INT_CST_LOW (val
) & (2 * nelts
- 1);
1851 maybe_identity2
= false;
1852 else if (j
== i
+ nelts
)
1853 maybe_identity1
= false;
1857 return maybe_identity1
? 1 : maybe_identity2
? 2 : 0;
1860 /* Combine a shuffle with its arguments. Returns 1 if there were any
1861 changes made, 2 if cfg-cleanup needs to run. Else it returns 0. */
1864 simplify_permutation (gimple_stmt_iterator
*gsi
)
1866 gimple stmt
= gsi_stmt (*gsi
);
1868 tree op0
, op1
, op2
, op3
, arg0
, arg1
;
1869 enum tree_code code
;
1870 bool single_use_op0
= false;
1872 gcc_checking_assert (gimple_assign_rhs_code (stmt
) == VEC_PERM_EXPR
);
1874 op0
= gimple_assign_rhs1 (stmt
);
1875 op1
= gimple_assign_rhs2 (stmt
);
1876 op2
= gimple_assign_rhs3 (stmt
);
1878 if (TREE_CODE (op2
) != VECTOR_CST
)
1881 if (TREE_CODE (op0
) == VECTOR_CST
)
1886 else if (TREE_CODE (op0
) == SSA_NAME
)
1888 def_stmt
= get_prop_source_stmt (op0
, false, &single_use_op0
);
1889 if (!def_stmt
|| !can_propagate_from (def_stmt
))
1892 code
= gimple_assign_rhs_code (def_stmt
);
1893 arg0
= gimple_assign_rhs1 (def_stmt
);
1898 /* Two consecutive shuffles. */
1899 if (code
== VEC_PERM_EXPR
)
1906 op3
= gimple_assign_rhs3 (def_stmt
);
1907 if (TREE_CODE (op3
) != VECTOR_CST
)
1909 ident
= is_combined_permutation_identity (op3
, op2
);
1912 orig
= (ident
== 1) ? gimple_assign_rhs1 (def_stmt
)
1913 : gimple_assign_rhs2 (def_stmt
);
1914 gimple_assign_set_rhs1 (stmt
, unshare_expr (orig
));
1915 gimple_assign_set_rhs_code (stmt
, TREE_CODE (orig
));
1916 gimple_set_num_ops (stmt
, 2);
1918 return remove_prop_source_from_use (op0
) ? 2 : 1;
1921 /* Shuffle of a constructor. */
1922 else if (code
== CONSTRUCTOR
|| code
== VECTOR_CST
)
1928 if (TREE_CODE (op0
) == SSA_NAME
&& !single_use_op0
)
1931 if (TREE_CODE (op1
) == VECTOR_CST
)
1933 else if (TREE_CODE (op1
) == SSA_NAME
)
1935 enum tree_code code2
;
1937 gimple def_stmt2
= get_prop_source_stmt (op1
, true, NULL
);
1938 if (!def_stmt2
|| !can_propagate_from (def_stmt2
))
1941 code2
= gimple_assign_rhs_code (def_stmt2
);
1942 if (code2
!= CONSTRUCTOR
&& code2
!= VECTOR_CST
)
1944 arg1
= gimple_assign_rhs1 (def_stmt2
);
1951 /* Already used twice in this statement. */
1952 if (TREE_CODE (op0
) == SSA_NAME
&& num_imm_uses (op0
) > 2)
1956 opt
= fold_ternary (VEC_PERM_EXPR
, TREE_TYPE (op0
), arg0
, arg1
, op2
);
1958 || (TREE_CODE (opt
) != CONSTRUCTOR
&& TREE_CODE (opt
) != VECTOR_CST
))
1960 gimple_assign_set_rhs_from_tree (gsi
, opt
);
1961 update_stmt (gsi_stmt (*gsi
));
1962 if (TREE_CODE (op0
) == SSA_NAME
)
1963 ret
= remove_prop_source_from_use (op0
);
1964 if (op0
!= op1
&& TREE_CODE (op1
) == SSA_NAME
)
1965 ret
|= remove_prop_source_from_use (op1
);
1972 /* Recognize a VEC_PERM_EXPR. Returns true if there were any changes. */
1975 simplify_vector_constructor (gimple_stmt_iterator
*gsi
)
1977 gimple stmt
= gsi_stmt (*gsi
);
1979 tree op
, op2
, orig
, type
, elem_type
;
1980 unsigned elem_size
, nelts
, i
;
1981 enum tree_code code
;
1982 constructor_elt
*elt
;
1986 gcc_checking_assert (gimple_assign_rhs_code (stmt
) == CONSTRUCTOR
);
1988 op
= gimple_assign_rhs1 (stmt
);
1989 type
= TREE_TYPE (op
);
1990 gcc_checking_assert (TREE_CODE (type
) == VECTOR_TYPE
);
1992 nelts
= TYPE_VECTOR_SUBPARTS (type
);
1993 elem_type
= TREE_TYPE (type
);
1994 elem_size
= TREE_INT_CST_LOW (TYPE_SIZE (elem_type
));
1996 sel
= XALLOCAVEC (unsigned char, nelts
);
1999 FOR_EACH_VEC_SAFE_ELT (CONSTRUCTOR_ELTS (op
), i
, elt
)
2006 if (TREE_CODE (elt
->value
) != SSA_NAME
)
2008 def_stmt
= get_prop_source_stmt (elt
->value
, false, NULL
);
2011 code
= gimple_assign_rhs_code (def_stmt
);
2012 if (code
!= BIT_FIELD_REF
)
2014 op1
= gimple_assign_rhs1 (def_stmt
);
2015 ref
= TREE_OPERAND (op1
, 0);
2023 if (TREE_CODE (ref
) != SSA_NAME
)
2025 if (!useless_type_conversion_p (type
, TREE_TYPE (ref
)))
2029 if (TREE_INT_CST_LOW (TREE_OPERAND (op1
, 1)) != elem_size
)
2031 sel
[i
] = TREE_INT_CST_LOW (TREE_OPERAND (op1
, 2)) / elem_size
;
2032 if (sel
[i
] != i
) maybe_ident
= false;
2038 gimple_assign_set_rhs_from_tree (gsi
, orig
);
2041 tree mask_type
, *mask_elts
;
2043 if (!can_vec_perm_p (TYPE_MODE (type
), false, sel
))
2046 = build_vector_type (build_nonstandard_integer_type (elem_size
, 1),
2048 if (GET_MODE_CLASS (TYPE_MODE (mask_type
)) != MODE_VECTOR_INT
2049 || GET_MODE_SIZE (TYPE_MODE (mask_type
))
2050 != GET_MODE_SIZE (TYPE_MODE (type
)))
2052 mask_elts
= XALLOCAVEC (tree
, nelts
);
2053 for (i
= 0; i
< nelts
; i
++)
2054 mask_elts
[i
] = build_int_cst (TREE_TYPE (mask_type
), sel
[i
]);
2055 op2
= build_vector (mask_type
, mask_elts
);
2056 gimple_assign_set_rhs_with_ops (gsi
, VEC_PERM_EXPR
, orig
, orig
, op2
);
2058 update_stmt (gsi_stmt (*gsi
));
2063 /* Primitive "lattice" function for gimple_simplify. */
2066 fwprop_ssa_val (tree name
)
2068 /* First valueize NAME. */
2069 if (TREE_CODE (name
) == SSA_NAME
2070 && SSA_NAME_VERSION (name
) < lattice
.length ())
2072 tree val
= lattice
[SSA_NAME_VERSION (name
)];
2076 /* We continue matching along SSA use-def edges for SSA names
2077 that are not single-use. Currently there are no patterns
2078 that would cause any issues with that. */
2082 /* Main entry point for the forward propagation and statement combine
2087 const pass_data pass_data_forwprop
=
2089 GIMPLE_PASS
, /* type */
2090 "forwprop", /* name */
2091 OPTGROUP_NONE
, /* optinfo_flags */
2092 TV_TREE_FORWPROP
, /* tv_id */
2093 ( PROP_cfg
| PROP_ssa
), /* properties_required */
2094 0, /* properties_provided */
2095 0, /* properties_destroyed */
2096 0, /* todo_flags_start */
2097 TODO_update_ssa
, /* todo_flags_finish */
2100 class pass_forwprop
: public gimple_opt_pass
2103 pass_forwprop (gcc::context
*ctxt
)
2104 : gimple_opt_pass (pass_data_forwprop
, ctxt
)
2107 /* opt_pass methods: */
2108 opt_pass
* clone () { return new pass_forwprop (m_ctxt
); }
2109 virtual bool gate (function
*) { return flag_tree_forwprop
; }
2110 virtual unsigned int execute (function
*);
2112 }; // class pass_forwprop
2115 pass_forwprop::execute (function
*fun
)
2117 unsigned int todoflags
= 0;
2119 cfg_changed
= false;
2121 /* Combine stmts with the stmts defining their operands. Do that
2122 in an order that guarantees visiting SSA defs before SSA uses. */
2123 lattice
.create (num_ssa_names
);
2124 lattice
.quick_grow_cleared (num_ssa_names
);
2125 int *postorder
= XNEWVEC (int, n_basic_blocks_for_fn (fun
));
2126 int postorder_num
= inverted_post_order_compute (postorder
);
2127 to_purge
= BITMAP_ALLOC (NULL
);
2128 for (int i
= 0; i
< postorder_num
; ++i
)
2130 gimple_stmt_iterator gsi
;
2131 basic_block bb
= BASIC_BLOCK_FOR_FN (fun
, postorder
[i
]);
2133 /* Apply forward propagation to all stmts in the basic-block.
2134 Note we update GSI within the loop as necessary. */
2135 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); )
2137 gimple stmt
= gsi_stmt (gsi
);
2139 enum tree_code code
;
2141 if (!is_gimple_assign (stmt
))
2147 lhs
= gimple_assign_lhs (stmt
);
2148 rhs
= gimple_assign_rhs1 (stmt
);
2149 code
= gimple_assign_rhs_code (stmt
);
2150 if (TREE_CODE (lhs
) != SSA_NAME
2151 || has_zero_uses (lhs
))
2157 /* If this statement sets an SSA_NAME to an address,
2158 try to propagate the address into the uses of the SSA_NAME. */
2159 if (code
== ADDR_EXPR
2160 /* Handle pointer conversions on invariant addresses
2161 as well, as this is valid gimple. */
2162 || (CONVERT_EXPR_CODE_P (code
)
2163 && TREE_CODE (rhs
) == ADDR_EXPR
2164 && POINTER_TYPE_P (TREE_TYPE (lhs
))))
2166 tree base
= get_base_address (TREE_OPERAND (rhs
, 0));
2169 || decl_address_invariant_p (base
))
2170 && !stmt_references_abnormal_ssa_name (stmt
)
2171 && forward_propagate_addr_expr (lhs
, rhs
, true))
2173 fwprop_invalidate_lattice (gimple_get_lhs (stmt
));
2174 release_defs (stmt
);
2175 gsi_remove (&gsi
, true);
2180 else if (code
== POINTER_PLUS_EXPR
)
2182 tree off
= gimple_assign_rhs2 (stmt
);
2183 if (TREE_CODE (off
) == INTEGER_CST
2184 && can_propagate_from (stmt
)
2185 && !simple_iv_increment_p (stmt
)
2186 /* ??? Better adjust the interface to that function
2187 instead of building new trees here. */
2188 && forward_propagate_addr_expr
2190 build1_loc (gimple_location (stmt
),
2191 ADDR_EXPR
, TREE_TYPE (rhs
),
2192 fold_build2 (MEM_REF
,
2193 TREE_TYPE (TREE_TYPE (rhs
)),
2195 fold_convert (ptr_type_node
,
2198 fwprop_invalidate_lattice (gimple_get_lhs (stmt
));
2199 release_defs (stmt
);
2200 gsi_remove (&gsi
, true);
2202 else if (is_gimple_min_invariant (rhs
))
2204 /* Make sure to fold &a[0] + off_1 here. */
2205 fold_stmt_inplace (&gsi
);
2207 if (gimple_assign_rhs_code (stmt
) == POINTER_PLUS_EXPR
)
2217 /* Combine stmts with the stmts defining their operands.
2218 Note we update GSI within the loop as necessary. */
2219 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
);)
2221 gimple stmt
= gsi_stmt (gsi
);
2222 gimple orig_stmt
= stmt
;
2223 bool changed
= false;
2225 /* Mark stmt as potentially needing revisiting. */
2226 gimple_set_plf (stmt
, GF_PLF_1
, false);
2228 if (fold_stmt (&gsi
, fwprop_ssa_val
))
2231 stmt
= gsi_stmt (gsi
);
2232 if (maybe_clean_or_replace_eh_stmt (orig_stmt
, stmt
))
2233 bitmap_set_bit (to_purge
, bb
->index
);
2234 /* Cleanup the CFG if we simplified a condition to
2236 if (gcond
*cond
= dyn_cast
<gcond
*> (stmt
))
2237 if (gimple_cond_true_p (cond
)
2238 || gimple_cond_false_p (cond
))
2243 switch (gimple_code (stmt
))
2247 tree rhs1
= gimple_assign_rhs1 (stmt
);
2248 enum tree_code code
= gimple_assign_rhs_code (stmt
);
2250 if (code
== COND_EXPR
2251 || code
== VEC_COND_EXPR
)
2253 /* In this case the entire COND_EXPR is in rhs1. */
2254 if (forward_propagate_into_cond (&gsi
))
2257 stmt
= gsi_stmt (gsi
);
2260 else if (TREE_CODE_CLASS (code
) == tcc_comparison
)
2263 did_something
= forward_propagate_into_comparison (&gsi
);
2264 if (did_something
== 2)
2266 changed
= did_something
!= 0;
2268 else if ((code
== PLUS_EXPR
2269 || code
== BIT_IOR_EXPR
2270 || code
== BIT_XOR_EXPR
)
2271 && simplify_rotate (&gsi
))
2273 else if (code
== VEC_PERM_EXPR
)
2275 int did_something
= simplify_permutation (&gsi
);
2276 if (did_something
== 2)
2278 changed
= did_something
!= 0;
2280 else if (code
== BIT_FIELD_REF
)
2281 changed
= simplify_bitfield_ref (&gsi
);
2282 else if (code
== CONSTRUCTOR
2283 && TREE_CODE (TREE_TYPE (rhs1
)) == VECTOR_TYPE
)
2284 changed
= simplify_vector_constructor (&gsi
);
2289 changed
= simplify_gimple_switch (as_a
<gswitch
*> (stmt
));
2295 = forward_propagate_into_gimple_cond (as_a
<gcond
*> (stmt
));
2296 if (did_something
== 2)
2298 changed
= did_something
!= 0;
2304 tree callee
= gimple_call_fndecl (stmt
);
2305 if (callee
!= NULL_TREE
2306 && DECL_BUILT_IN_CLASS (callee
) == BUILT_IN_NORMAL
)
2307 changed
= simplify_builtin_call (&gsi
, callee
);
2316 /* If the stmt changed then re-visit it and the statements
2317 inserted before it. */
2318 for (; !gsi_end_p (gsi
); gsi_prev (&gsi
))
2319 if (gimple_plf (gsi_stmt (gsi
), GF_PLF_1
))
2321 if (gsi_end_p (gsi
))
2322 gsi
= gsi_start_bb (bb
);
2328 /* Stmt no longer needs to be revisited. */
2329 gimple_set_plf (stmt
, GF_PLF_1
, true);
2331 /* Fill up the lattice. */
2332 if (gimple_assign_single_p (stmt
))
2334 tree lhs
= gimple_assign_lhs (stmt
);
2335 tree rhs
= gimple_assign_rhs1 (stmt
);
2336 if (TREE_CODE (lhs
) == SSA_NAME
)
2339 if (TREE_CODE (rhs
) == SSA_NAME
)
2340 val
= fwprop_ssa_val (rhs
);
2341 else if (is_gimple_min_invariant (rhs
))
2343 fwprop_set_lattice_val (lhs
, val
);
2354 cfg_changed
|= gimple_purge_all_dead_eh_edges (to_purge
);
2355 BITMAP_FREE (to_purge
);
2358 todoflags
|= TODO_cleanup_cfg
;
2366 make_pass_forwprop (gcc::context
*ctxt
)
2368 return new pass_forwprop (ctxt
);