1 /* SSA operands management for trees.
2 Copyright (C) 2003, 2004, 2005 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 2, 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 COPYING. If not, write to
18 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
19 Boston, MA 02110-1301, USA. */
23 #include "coretypes.h"
28 #include "diagnostic.h"
29 #include "tree-flow.h"
30 #include "tree-inline.h"
31 #include "tree-pass.h"
35 #include "langhooks.h"
36 #include "ipa-reference.h"
38 /* This file contains the code required to manage the operands cache of the
39 SSA optimizer. For every stmt, we maintain an operand cache in the stmt
40 annotation. This cache contains operands that will be of interest to
41 optimizers and other passes wishing to manipulate the IL.
43 The operand type are broken up into REAL and VIRTUAL operands. The real
44 operands are represented as pointers into the stmt's operand tree. Thus
45 any manipulation of the real operands will be reflected in the actual tree.
46 Virtual operands are represented solely in the cache, although the base
47 variable for the SSA_NAME may, or may not occur in the stmt's tree.
48 Manipulation of the virtual operands will not be reflected in the stmt tree.
50 The routines in this file are concerned with creating this operand cache
53 The operand tree is the parsed by the various get_* routines which look
54 through the stmt tree for the occurrence of operands which may be of
55 interest, and calls are made to the append_* routines whenever one is
56 found. There are 5 of these routines, each representing one of the
57 5 types of operands. Defs, Uses, Virtual Uses, Virtual May Defs, and
60 The append_* routines check for duplication, and simply keep a list of
61 unique objects for each operand type in the build_* extendable vectors.
63 Once the stmt tree is completely parsed, the finalize_ssa_operands()
64 routine is called, which proceeds to perform the finalization routine
65 on each of the 5 operand vectors which have been built up.
67 If the stmt had a previous operand cache, the finalization routines
68 attempt to match up the new operands with the old ones. If it's a perfect
69 match, the old vector is simply reused. If it isn't a perfect match, then
70 a new vector is created and the new operands are placed there. For
71 virtual operands, if the previous cache had SSA_NAME version of a
72 variable, and that same variable occurs in the same operands cache, then
73 the new cache vector will also get the same SSA_NAME.
75 i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new operand
76 vector for VUSE, then the new vector will also be modified such that
77 it contains 'a_5' rather than 'a'.
82 /* Flags to describe operand properties in helpers. */
84 /* By default, operands are loaded. */
87 /* Operand is the target of an assignment expression or a
88 call-clobbered variable */
89 #define opf_is_def (1 << 0)
91 /* Operand is the target of an assignment expression. */
92 #define opf_kill_def (1 << 1)
94 /* No virtual operands should be created in the expression. This is used
95 when traversing ADDR_EXPR nodes which have different semantics than
96 other expressions. Inside an ADDR_EXPR node, the only operands that we
97 need to consider are indices into arrays. For instance, &a.b[i] should
98 generate a USE of 'i' but it should not generate a VUSE for 'a' nor a
100 #define opf_no_vops (1 << 2)
102 /* Operand is a "non-specific" kill for call-clobbers and such. This is used
103 to distinguish "reset the world" events from explicit MODIFY_EXPRs. */
104 #define opf_non_specific (1 << 3)
107 /* Array for building all the def operands. */
108 static VEC(tree,heap) *build_defs;
110 /* Array for building all the use operands. */
111 static VEC(tree,heap) *build_uses;
113 /* Array for building all the v_may_def operands. */
114 static VEC(tree,heap) *build_v_may_defs;
116 /* Array for building all the vuse operands. */
117 static VEC(tree,heap) *build_vuses;
119 /* Array for building all the v_must_def operands. */
120 static VEC(tree,heap) *build_v_must_defs;
122 /* True if the operands for call clobbered vars are cached and valid. */
123 bool ssa_call_clobbered_cache_valid;
124 bool ssa_ro_call_cache_valid;
126 /* These arrays are the cached operand vectors for call clobbered calls. */
127 static VEC(tree,heap) *clobbered_v_may_defs;
128 static VEC(tree,heap) *clobbered_vuses;
129 static VEC(tree,heap) *ro_call_vuses;
130 static bool clobbered_aliased_loads;
131 static bool clobbered_aliased_stores;
132 static bool ro_call_aliased_loads;
133 static bool ops_active = false;
135 static GTY (()) struct ssa_operand_memory_d *operand_memory = NULL;
136 static unsigned operand_memory_index;
138 static void get_expr_operands (tree, tree *, int);
139 static void get_asm_expr_operands (tree);
140 static void get_indirect_ref_operands (tree, tree, int);
141 static void get_tmr_operands (tree, tree, int);
142 static void get_call_expr_operands (tree, tree);
143 static inline void append_def (tree *);
144 static inline void append_use (tree *);
145 static void append_v_may_def (tree);
146 static void append_v_must_def (tree);
147 static void add_call_clobber_ops (tree, tree);
148 static void add_call_read_ops (tree);
149 static void add_stmt_operand (tree *, stmt_ann_t, int);
150 static void build_ssa_operands (tree stmt);
152 static def_optype_p free_defs = NULL;
153 static use_optype_p free_uses = NULL;
154 static vuse_optype_p free_vuses = NULL;
155 static maydef_optype_p free_maydefs = NULL;
156 static mustdef_optype_p free_mustdefs = NULL;
159 /* Return the DECL_UID of the base variable of T. */
161 static inline unsigned
162 get_name_decl (tree t)
164 if (TREE_CODE (t) != SSA_NAME)
167 return DECL_UID (SSA_NAME_VAR (t));
170 /* Comparison function for qsort used in operand_build_sort_virtual. */
173 operand_build_cmp (const void *p, const void *q)
175 tree e1 = *((const tree *)p);
176 tree e2 = *((const tree *)q);
179 u1 = get_name_decl (e1);
180 u2 = get_name_decl (e2);
182 /* We want to sort in ascending order. They can never be equal. */
183 #ifdef ENABLE_CHECKING
184 gcc_assert (u1 != u2);
186 return (u1 > u2 ? 1 : -1);
189 /* Sort the virtual operands in LIST from lowest DECL_UID to highest. */
192 operand_build_sort_virtual (VEC(tree,heap) *list)
194 int num = VEC_length (tree, list);
199 if (get_name_decl (VEC_index (tree, list, 0))
200 > get_name_decl (VEC_index (tree, list, 1)))
202 /* Swap elements if in the wrong order. */
203 tree tmp = VEC_index (tree, list, 0);
204 VEC_replace (tree, list, 0, VEC_index (tree, list, 1));
205 VEC_replace (tree, list, 1, tmp);
209 /* There are 3 or more elements, call qsort. */
210 qsort (VEC_address (tree, list),
211 VEC_length (tree, list),
218 /* Return true if the ssa operands cache is active. */
221 ssa_operands_active (void)
227 /* Initialize the operand cache routines. */
230 init_ssa_operands (void)
232 build_defs = VEC_alloc (tree, heap, 5);
233 build_uses = VEC_alloc (tree, heap, 10);
234 build_vuses = VEC_alloc (tree, heap, 25);
235 build_v_may_defs = VEC_alloc (tree, heap, 25);
236 build_v_must_defs = VEC_alloc (tree, heap, 25);
238 gcc_assert (operand_memory == NULL);
239 operand_memory_index = SSA_OPERAND_MEMORY_SIZE;
244 /* Dispose of anything required by the operand routines. */
247 fini_ssa_operands (void)
249 struct ssa_operand_memory_d *ptr;
250 VEC_free (tree, heap, build_defs);
251 VEC_free (tree, heap, build_uses);
252 VEC_free (tree, heap, build_v_must_defs);
253 VEC_free (tree, heap, build_v_may_defs);
254 VEC_free (tree, heap, build_vuses);
259 free_mustdefs = NULL;
260 while ((ptr = operand_memory) != NULL)
262 operand_memory = operand_memory->next;
266 VEC_free (tree, heap, clobbered_v_may_defs);
267 VEC_free (tree, heap, clobbered_vuses);
268 VEC_free (tree, heap, ro_call_vuses);
273 /* Return memory for operands of SIZE chunks. */
276 ssa_operand_alloc (unsigned size)
279 if (operand_memory_index + size >= SSA_OPERAND_MEMORY_SIZE)
281 struct ssa_operand_memory_d *ptr;
282 ptr = ggc_alloc (sizeof (struct ssa_operand_memory_d));
283 ptr->next = operand_memory;
284 operand_memory = ptr;
285 operand_memory_index = 0;
287 ptr = &(operand_memory->mem[operand_memory_index]);
288 operand_memory_index += size;
293 /* Make sure PTR is in the correct immediate use list. Since uses are simply
294 pointers into the stmt TREE, there is no way of telling if anyone has
295 changed what this pointer points to via TREE_OPERANDS (exp, 0) = <...>.
296 The contents are different, but the pointer is still the same. This
297 routine will check to make sure PTR is in the correct list, and if it isn't
298 put it in the correct list. We cannot simply check the previous node
299 because all nodes in the same stmt might have be changed. */
302 correct_use_link (use_operand_p ptr, tree stmt)
307 /* Fold_stmt () may have changed the stmt pointers. */
308 if (ptr->stmt != stmt)
314 /* Find the root element, making sure we skip any safe iterators. */
315 while (prev->use != NULL || prev->stmt == NULL)
318 /* Get the ssa_name of the list the node is in. */
320 /* If it's the right list, simply return. */
321 if (root == *(ptr->use))
324 /* Its in the wrong list if we reach here. */
325 delink_imm_use (ptr);
326 link_imm_use (ptr, *(ptr->use));
330 /* This routine makes sure that PTR is in an immediate use list, and makes
331 sure the stmt pointer is set to the current stmt. Virtual uses do not need
332 the overhead of correct_use_link since they cannot be directly manipulated
333 like a real use can be. (They don't exist in the TREE_OPERAND nodes.) */
335 set_virtual_use_link (use_operand_p ptr, tree stmt)
337 /* Fold_stmt () may have changed the stmt pointers. */
338 if (ptr->stmt != stmt)
341 /* If this use isn't in a list, add it to the correct list. */
343 link_imm_use (ptr, *(ptr->use));
348 #define FINALIZE_OPBUILD build_defs
349 #define FINALIZE_OPBUILD_BASE(I) (tree *)VEC_index (tree, \
351 #define FINALIZE_OPBUILD_ELEM(I) (tree *)VEC_index (tree, \
353 #define FINALIZE_FUNC finalize_ssa_def_ops
354 #define FINALIZE_ALLOC alloc_def
355 #define FINALIZE_FREE free_defs
356 #define FINALIZE_TYPE struct def_optype_d
357 #define FINALIZE_ELEM(PTR) ((PTR)->def_ptr)
358 #define FINALIZE_OPS DEF_OPS
359 #define FINALIZE_BASE(VAR) VAR
360 #define FINALIZE_BASE_TYPE tree *
361 #define FINALIZE_BASE_ZERO NULL
362 #define FINALIZE_INITIALIZE(PTR, VAL, STMT) FINALIZE_ELEM (PTR) = (VAL)
363 #include "tree-ssa-opfinalize.h"
366 /* This routine will create stmt operands for STMT from the def build list. */
369 finalize_ssa_defs (tree stmt)
371 unsigned int num = VEC_length (tree, build_defs);
372 /* There should only be a single real definition per assignment. */
373 gcc_assert ((stmt && TREE_CODE (stmt) != MODIFY_EXPR) || num <= 1);
375 /* If there is an old list, often the new list is identical, or close, so
376 find the elements at the beginning that are the same as the vector. */
378 finalize_ssa_def_ops (stmt);
379 VEC_truncate (tree, build_defs, 0);
382 #define FINALIZE_OPBUILD build_uses
383 #define FINALIZE_OPBUILD_BASE(I) (tree *)VEC_index (tree, \
385 #define FINALIZE_OPBUILD_ELEM(I) (tree *)VEC_index (tree, \
387 #define FINALIZE_FUNC finalize_ssa_use_ops
388 #define FINALIZE_ALLOC alloc_use
389 #define FINALIZE_FREE free_uses
390 #define FINALIZE_TYPE struct use_optype_d
391 #define FINALIZE_ELEM(PTR) ((PTR)->use_ptr.use)
392 #define FINALIZE_OPS USE_OPS
393 #define FINALIZE_USE_PTR(PTR) USE_OP_PTR (PTR)
394 #define FINALIZE_CORRECT_USE correct_use_link
395 #define FINALIZE_BASE(VAR) VAR
396 #define FINALIZE_BASE_TYPE tree *
397 #define FINALIZE_BASE_ZERO NULL
398 #define FINALIZE_INITIALIZE(PTR, VAL, STMT) \
399 (PTR)->use_ptr.use = (VAL); \
400 link_imm_use_stmt (&((PTR)->use_ptr), \
402 #include "tree-ssa-opfinalize.h"
404 /* Return a new use operand vector for STMT, comparing to OLD_OPS_P. */
407 finalize_ssa_uses (tree stmt)
409 #ifdef ENABLE_CHECKING
412 unsigned num = VEC_length (tree, build_uses);
414 /* If the pointer to the operand is the statement itself, something is
415 wrong. It means that we are pointing to a local variable (the
416 initial call to get_stmt_operands does not pass a pointer to a
418 for (x = 0; x < num; x++)
419 gcc_assert (*((tree *)VEC_index (tree, build_uses, x)) != stmt);
422 finalize_ssa_use_ops (stmt);
423 VEC_truncate (tree, build_uses, 0);
427 /* Return a new v_may_def operand vector for STMT, comparing to OLD_OPS_P. */
428 #define FINALIZE_OPBUILD build_v_may_defs
429 #define FINALIZE_OPBUILD_ELEM(I) VEC_index (tree, build_v_may_defs, (I))
430 #define FINALIZE_OPBUILD_BASE(I) get_name_decl (VEC_index (tree, \
431 build_v_may_defs, (I)))
432 #define FINALIZE_FUNC finalize_ssa_v_may_def_ops
433 #define FINALIZE_ALLOC alloc_maydef
434 #define FINALIZE_FREE free_maydefs
435 #define FINALIZE_TYPE struct maydef_optype_d
436 #define FINALIZE_ELEM(PTR) MAYDEF_RESULT (PTR)
437 #define FINALIZE_OPS MAYDEF_OPS
438 #define FINALIZE_USE_PTR(PTR) MAYDEF_OP_PTR (PTR)
439 #define FINALIZE_CORRECT_USE set_virtual_use_link
440 #define FINALIZE_BASE_ZERO 0
441 #define FINALIZE_BASE(VAR) get_name_decl (VAR)
442 #define FINALIZE_BASE_TYPE unsigned
443 #define FINALIZE_INITIALIZE(PTR, VAL, STMT) \
444 (PTR)->def_var = (VAL); \
445 (PTR)->use_var = (VAL); \
446 (PTR)->use_ptr.use = &((PTR)->use_var); \
447 link_imm_use_stmt (&((PTR)->use_ptr), \
449 #include "tree-ssa-opfinalize.h"
453 finalize_ssa_v_may_defs (tree stmt)
455 finalize_ssa_v_may_def_ops (stmt);
459 /* Clear the in_list bits and empty the build array for v_may_defs. */
462 cleanup_v_may_defs (void)
465 num = VEC_length (tree, build_v_may_defs);
467 for (x = 0; x < num; x++)
469 tree t = VEC_index (tree, build_v_may_defs, x);
470 if (TREE_CODE (t) != SSA_NAME)
472 var_ann_t ann = var_ann (t);
473 ann->in_v_may_def_list = 0;
476 VEC_truncate (tree, build_v_may_defs, 0);
480 #define FINALIZE_OPBUILD build_vuses
481 #define FINALIZE_OPBUILD_ELEM(I) VEC_index (tree, build_vuses, (I))
482 #define FINALIZE_OPBUILD_BASE(I) get_name_decl (VEC_index (tree, \
484 #define FINALIZE_FUNC finalize_ssa_vuse_ops
485 #define FINALIZE_ALLOC alloc_vuse
486 #define FINALIZE_FREE free_vuses
487 #define FINALIZE_TYPE struct vuse_optype_d
488 #define FINALIZE_ELEM(PTR) VUSE_OP (PTR)
489 #define FINALIZE_OPS VUSE_OPS
490 #define FINALIZE_USE_PTR(PTR) VUSE_OP_PTR (PTR)
491 #define FINALIZE_CORRECT_USE set_virtual_use_link
492 #define FINALIZE_BASE_ZERO 0
493 #define FINALIZE_BASE(VAR) get_name_decl (VAR)
494 #define FINALIZE_BASE_TYPE unsigned
495 #define FINALIZE_INITIALIZE(PTR, VAL, STMT) \
496 (PTR)->use_var = (VAL); \
497 (PTR)->use_ptr.use = &((PTR)->use_var); \
498 link_imm_use_stmt (&((PTR)->use_ptr), \
500 #include "tree-ssa-opfinalize.h"
503 /* Return a new vuse operand vector, comparing to OLD_OPS_P. */
506 finalize_ssa_vuses (tree stmt)
508 unsigned num, num_v_may_defs;
511 /* Remove superfluous VUSE operands. If the statement already has a
512 V_MAY_DEF operation for a variable 'a', then a VUSE for 'a' is not
513 needed because V_MAY_DEFs imply a VUSE of the variable. For instance,
514 suppose that variable 'a' is aliased:
517 # a_3 = V_MAY_DEF <a_2>
520 The VUSE <a_2> is superfluous because it is implied by the V_MAY_DEF
523 num = VEC_length (tree, build_vuses);
524 num_v_may_defs = VEC_length (tree, build_v_may_defs);
526 if (num > 0 && num_v_may_defs > 0)
528 for (vuse_index = 0; vuse_index < VEC_length (tree, build_vuses); )
531 vuse = VEC_index (tree, build_vuses, vuse_index);
532 if (TREE_CODE (vuse) != SSA_NAME)
534 var_ann_t ann = var_ann (vuse);
535 ann->in_vuse_list = 0;
536 if (ann->in_v_may_def_list)
538 VEC_ordered_remove (tree, build_vuses, vuse_index);
546 /* Clear out the in_list bits. */
548 vuse_index < VEC_length (tree, build_vuses);
551 tree t = VEC_index (tree, build_vuses, vuse_index);
552 if (TREE_CODE (t) != SSA_NAME)
554 var_ann_t ann = var_ann (t);
555 ann->in_vuse_list = 0;
559 finalize_ssa_vuse_ops (stmt);
560 /* The v_may_def build vector wasn't cleaned up because we needed it. */
561 cleanup_v_may_defs ();
563 /* Free the vuses build vector. */
564 VEC_truncate (tree, build_vuses, 0);
568 /* Return a new v_must_def operand vector for STMT, comparing to OLD_OPS_P. */
570 #define FINALIZE_OPBUILD build_v_must_defs
571 #define FINALIZE_OPBUILD_ELEM(I) VEC_index (tree, build_v_must_defs, (I))
572 #define FINALIZE_OPBUILD_BASE(I) get_name_decl (VEC_index (tree, \
573 build_v_must_defs, (I)))
574 #define FINALIZE_FUNC finalize_ssa_v_must_def_ops
575 #define FINALIZE_ALLOC alloc_mustdef
576 #define FINALIZE_FREE free_mustdefs
577 #define FINALIZE_TYPE struct mustdef_optype_d
578 #define FINALIZE_ELEM(PTR) MUSTDEF_RESULT (PTR)
579 #define FINALIZE_OPS MUSTDEF_OPS
580 #define FINALIZE_USE_PTR(PTR) MUSTDEF_KILL_PTR (PTR)
581 #define FINALIZE_CORRECT_USE set_virtual_use_link
582 #define FINALIZE_BASE_ZERO 0
583 #define FINALIZE_BASE(VAR) get_name_decl (VAR)
584 #define FINALIZE_BASE_TYPE unsigned
585 #define FINALIZE_INITIALIZE(PTR, VAL, STMT) \
586 (PTR)->def_var = (VAL); \
587 (PTR)->kill_var = (VAL); \
588 (PTR)->use_ptr.use = &((PTR)->kill_var);\
589 link_imm_use_stmt (&((PTR)->use_ptr), \
591 #include "tree-ssa-opfinalize.h"
595 finalize_ssa_v_must_defs (tree stmt)
597 /* In the presence of subvars, there may be more than one V_MUST_DEF per
598 statement (one for each subvar). It is a bit expensive to verify that
599 all must-defs in a statement belong to subvars if there is more than one
600 MUST-def, so we don't do it. Suffice to say, if you reach here without
601 having subvars, and have num >1, you have hit a bug. */
603 finalize_ssa_v_must_def_ops (stmt);
604 VEC_truncate (tree, build_v_must_defs, 0);
608 /* Finalize all the build vectors, fill the new ones into INFO. */
611 finalize_ssa_stmt_operands (tree stmt)
613 finalize_ssa_defs (stmt);
614 finalize_ssa_uses (stmt);
615 finalize_ssa_v_must_defs (stmt);
616 finalize_ssa_v_may_defs (stmt);
617 finalize_ssa_vuses (stmt);
621 /* Start the process of building up operands vectors in INFO. */
624 start_ssa_stmt_operands (void)
626 gcc_assert (VEC_length (tree, build_defs) == 0);
627 gcc_assert (VEC_length (tree, build_uses) == 0);
628 gcc_assert (VEC_length (tree, build_vuses) == 0);
629 gcc_assert (VEC_length (tree, build_v_may_defs) == 0);
630 gcc_assert (VEC_length (tree, build_v_must_defs) == 0);
634 /* Add DEF_P to the list of pointers to operands. */
637 append_def (tree *def_p)
639 VEC_safe_push (tree, heap, build_defs, (tree)def_p);
643 /* Add USE_P to the list of pointers to operands. */
646 append_use (tree *use_p)
648 VEC_safe_push (tree, heap, build_uses, (tree)use_p);
652 /* Add a new virtual may def for variable VAR to the build array. */
655 append_v_may_def (tree var)
657 if (TREE_CODE (var) != SSA_NAME)
659 var_ann_t ann = get_var_ann (var);
661 /* Don't allow duplicate entries. */
662 if (ann->in_v_may_def_list)
664 ann->in_v_may_def_list = 1;
667 VEC_safe_push (tree, heap, build_v_may_defs, (tree)var);
671 /* Add VAR to the list of virtual uses. */
674 append_vuse (tree var)
677 /* Don't allow duplicate entries. */
678 if (TREE_CODE (var) != SSA_NAME)
680 var_ann_t ann = get_var_ann (var);
682 if (ann->in_vuse_list || ann->in_v_may_def_list)
684 ann->in_vuse_list = 1;
687 VEC_safe_push (tree, heap, build_vuses, (tree)var);
691 /* Add VAR to the list of virtual must definitions for INFO. */
694 append_v_must_def (tree var)
698 /* Don't allow duplicate entries. */
699 for (i = 0; i < VEC_length (tree, build_v_must_defs); i++)
700 if (var == VEC_index (tree, build_v_must_defs, i))
703 VEC_safe_push (tree, heap, build_v_must_defs, (tree)var);
707 /* Parse STMT looking for operands. OLD_OPS is the original stmt operand
708 cache for STMT, if it existed before. When finished, the various build_*
709 operand vectors will have potential operands. in them. */
712 parse_ssa_operands (tree stmt)
716 code = TREE_CODE (stmt);
720 /* First get operands from the RHS. For the LHS, we use a V_MAY_DEF if
721 either only part of LHS is modified or if the RHS might throw,
722 otherwise, use V_MUST_DEF.
724 ??? If it might throw, we should represent somehow that it is killed
725 on the fallthrough path. */
727 tree lhs = TREE_OPERAND (stmt, 0);
728 int lhs_flags = opf_is_def;
730 get_expr_operands (stmt, &TREE_OPERAND (stmt, 1), opf_none);
732 /* If the LHS is a VIEW_CONVERT_EXPR, it isn't changing whether
733 or not the entire LHS is modified; that depends on what's
734 inside the VIEW_CONVERT_EXPR. */
735 if (TREE_CODE (lhs) == VIEW_CONVERT_EXPR)
736 lhs = TREE_OPERAND (lhs, 0);
738 if (TREE_CODE (lhs) != ARRAY_REF
739 && TREE_CODE (lhs) != ARRAY_RANGE_REF
740 && TREE_CODE (lhs) != BIT_FIELD_REF
741 && TREE_CODE (lhs) != REALPART_EXPR
742 && TREE_CODE (lhs) != IMAGPART_EXPR)
743 lhs_flags |= opf_kill_def;
745 get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), lhs_flags);
750 get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none);
754 get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none);
758 get_asm_expr_operands (stmt);
762 get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), opf_none);
766 get_expr_operands (stmt, &GOTO_DESTINATION (stmt), opf_none);
770 get_expr_operands (stmt, &LABEL_EXPR_LABEL (stmt), opf_none);
773 /* These nodes contain no variable references. */
775 case CASE_LABEL_EXPR:
777 case TRY_FINALLY_EXPR:
784 /* Notice that if get_expr_operands tries to use &STMT as the operand
785 pointer (which may only happen for USE operands), we will fail in
786 append_use. This default will handle statements like empty
787 statements, or CALL_EXPRs that may appear on the RHS of a statement
788 or as statements themselves. */
789 get_expr_operands (stmt, &stmt, opf_none);
794 /* Create an operands cache for STMT. */
797 build_ssa_operands (tree stmt)
799 stmt_ann_t ann = get_stmt_ann (stmt);
801 /* Initially assume that the statement has no volatile operands, nor
802 makes aliased loads or stores. */
805 ann->has_volatile_ops = false;
806 ann->makes_aliased_stores = false;
807 ann->makes_aliased_loads = false;
810 start_ssa_stmt_operands ();
812 parse_ssa_operands (stmt);
813 operand_build_sort_virtual (build_vuses);
814 operand_build_sort_virtual (build_v_may_defs);
815 operand_build_sort_virtual (build_v_must_defs);
817 finalize_ssa_stmt_operands (stmt);
821 /* Free any operands vectors in OPS. */
823 free_ssa_operands (stmt_operands_p ops)
827 ops->maydef_ops = NULL;
828 ops->mustdef_ops = NULL;
829 ops->vuse_ops = NULL;
833 /* Get the operands of statement STMT. Note that repeated calls to
834 get_stmt_operands for the same statement will do nothing until the
835 statement is marked modified by a call to mark_stmt_modified(). */
838 update_stmt_operands (tree stmt)
840 stmt_ann_t ann = get_stmt_ann (stmt);
841 /* If get_stmt_operands is called before SSA is initialized, dont
843 if (!ssa_operands_active ())
845 /* The optimizers cannot handle statements that are nothing but a
846 _DECL. This indicates a bug in the gimplifier. */
847 gcc_assert (!SSA_VAR_P (stmt));
849 gcc_assert (ann->modified);
851 timevar_push (TV_TREE_OPS);
853 build_ssa_operands (stmt);
855 /* Clear the modified bit for STMT. Subsequent calls to
856 get_stmt_operands for this statement will do nothing until the
857 statement is marked modified by a call to mark_stmt_modified(). */
860 timevar_pop (TV_TREE_OPS);
864 /* Copies virtual operands from SRC to DST. */
867 copy_virtual_operands (tree dest, tree src)
870 ssa_op_iter iter, old_iter;
871 use_operand_p use_p, u2;
872 def_operand_p def_p, d2;
874 build_ssa_operands (dest);
876 /* Copy all the virtual fields. */
877 FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VUSE)
879 FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMAYDEF)
880 append_v_may_def (t);
881 FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMUSTDEF)
882 append_v_must_def (t);
884 if (VEC_length (tree, build_vuses) == 0
885 && VEC_length (tree, build_v_may_defs) == 0
886 && VEC_length (tree, build_v_must_defs) == 0)
889 /* Now commit the virtual operands to this stmt. */
890 finalize_ssa_v_must_defs (dest);
891 finalize_ssa_v_may_defs (dest);
892 finalize_ssa_vuses (dest);
894 /* Finally, set the field to the same values as then originals. */
897 t = op_iter_init_tree (&old_iter, src, SSA_OP_VUSE);
898 FOR_EACH_SSA_USE_OPERAND (use_p, dest, iter, SSA_OP_VUSE)
900 gcc_assert (!op_iter_done (&old_iter));
902 t = op_iter_next_tree (&old_iter);
904 gcc_assert (op_iter_done (&old_iter));
906 op_iter_init_maydef (&old_iter, src, &u2, &d2);
907 FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, dest, iter)
909 gcc_assert (!op_iter_done (&old_iter));
910 SET_USE (use_p, USE_FROM_PTR (u2));
911 SET_DEF (def_p, DEF_FROM_PTR (d2));
912 op_iter_next_maymustdef (&u2, &d2, &old_iter);
914 gcc_assert (op_iter_done (&old_iter));
916 op_iter_init_mustdef (&old_iter, src, &u2, &d2);
917 FOR_EACH_SSA_MUSTDEF_OPERAND (def_p, use_p, dest, iter)
919 gcc_assert (!op_iter_done (&old_iter));
920 SET_USE (use_p, USE_FROM_PTR (u2));
921 SET_DEF (def_p, DEF_FROM_PTR (d2));
922 op_iter_next_maymustdef (&u2, &d2, &old_iter);
924 gcc_assert (op_iter_done (&old_iter));
929 /* Specifically for use in DOM's expression analysis. Given a store, we
930 create an artificial stmt which looks like a load from the store, this can
931 be used to eliminate redundant loads. OLD_OPS are the operands from the
932 store stmt, and NEW_STMT is the new load which represents a load of the
936 create_ssa_artficial_load_stmt (tree new_stmt, tree old_stmt)
944 ann = get_stmt_ann (new_stmt);
946 /* process the stmt looking for operands. */
947 start_ssa_stmt_operands ();
948 parse_ssa_operands (new_stmt);
950 for (x = 0; x < VEC_length (tree, build_vuses); x++)
952 tree t = VEC_index (tree, build_vuses, x);
953 if (TREE_CODE (t) != SSA_NAME)
955 var_ann_t ann = var_ann (t);
956 ann->in_vuse_list = 0;
960 for (x = 0; x < VEC_length (tree, build_v_may_defs); x++)
962 tree t = VEC_index (tree, build_v_may_defs, x);
963 if (TREE_CODE (t) != SSA_NAME)
965 var_ann_t ann = var_ann (t);
966 ann->in_v_may_def_list = 0;
969 /* Remove any virtual operands that were found. */
970 VEC_truncate (tree, build_v_may_defs, 0);
971 VEC_truncate (tree, build_v_must_defs, 0);
972 VEC_truncate (tree, build_vuses, 0);
974 /* For each VDEF on the original statement, we want to create a
975 VUSE of the V_MAY_DEF result or V_MUST_DEF op on the new
977 FOR_EACH_SSA_TREE_OPERAND (op, old_stmt, iter,
978 (SSA_OP_VMAYDEF | SSA_OP_VMUSTDEF))
981 /* Now build the operands for this new stmt. */
982 finalize_ssa_stmt_operands (new_stmt);
984 /* All uses in this fake stmt must not be in the immediate use lists. */
985 FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES)
986 delink_imm_use (use_p);
990 swap_tree_operands (tree stmt, tree *exp0, tree *exp1)
996 /* If the operand cache is active, attempt to preserve the relative positions
997 of these two operands in their respective immediate use lists. */
998 if (ssa_operands_active () && op0 != op1)
1000 use_optype_p use0, use1, ptr;
1002 /* Find the 2 operands in the cache, if they are there. */
1003 for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
1004 if (USE_OP_PTR (ptr)->use == exp0)
1009 for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
1010 if (USE_OP_PTR (ptr)->use == exp1)
1015 /* If both uses don't have operand entries, there isn't much we can do
1016 at this point. Presumably we dont need to worry about it. */
1019 tree *tmp = USE_OP_PTR (use1)->use;
1020 USE_OP_PTR (use1)->use = USE_OP_PTR (use0)->use;
1021 USE_OP_PTR (use0)->use = tmp;
1025 /* Now swap the data. */
1030 /* Recursively scan the expression pointed to by EXPR_P in statement referred
1031 to by INFO. FLAGS is one of the OPF_* constants modifying how to interpret
1032 the operands found. */
1035 get_expr_operands (tree stmt, tree *expr_p, int flags)
1037 enum tree_code code;
1038 enum tree_code_class class;
1039 tree expr = *expr_p;
1040 stmt_ann_t s_ann = stmt_ann (stmt);
1045 code = TREE_CODE (expr);
1046 class = TREE_CODE_CLASS (code);
1051 /* We could have the address of a component, array member,
1052 etc which has interesting variable references. */
1053 /* Taking the address of a variable does not represent a
1054 reference to it, but the fact that the stmt takes its address will be
1055 of interest to some passes (e.g. alias resolution). */
1056 add_stmt_operand (expr_p, s_ann, 0);
1058 /* If the address is invariant, there may be no interesting variable
1059 references inside. */
1060 if (is_gimple_min_invariant (expr))
1063 /* There should be no VUSEs created, since the referenced objects are
1064 not really accessed. The only operands that we should find here
1065 are ARRAY_REF indices which will always be real operands (GIMPLE
1066 does not allow non-registers as array indices). */
1067 flags |= opf_no_vops;
1069 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
1073 case STRUCT_FIELD_TAG:
1074 case TYPE_MEMORY_TAG:
1075 case NAME_MEMORY_TAG:
1083 /* Add the subvars for a variable if it has subvars, to DEFS or USES.
1084 Otherwise, add the variable itself.
1085 Whether it goes to USES or DEFS depends on the operand flags. */
1086 if (var_can_have_subvars (expr)
1087 && (svars = get_subvars_for_var (expr)))
1090 for (sv = svars; sv; sv = sv->next)
1091 add_stmt_operand (&sv->var, s_ann, flags);
1095 add_stmt_operand (expr_p, s_ann, flags);
1099 case MISALIGNED_INDIRECT_REF:
1100 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
1103 case ALIGN_INDIRECT_REF:
1105 get_indirect_ref_operands (stmt, expr, flags);
1108 case TARGET_MEM_REF:
1109 get_tmr_operands (stmt, expr, flags);
1113 case ARRAY_RANGE_REF:
1114 /* Treat array references as references to the virtual variable
1115 representing the array. The virtual variable for an ARRAY_REF
1116 is the VAR_DECL for the array. */
1118 /* Add the virtual variable for the ARRAY_REF to VDEFS or VUSES
1119 according to the value of IS_DEF. Recurse if the LHS of the
1120 ARRAY_REF node is not a regular variable. */
1121 if (SSA_VAR_P (TREE_OPERAND (expr, 0)))
1122 add_stmt_operand (expr_p, s_ann, flags);
1124 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
1126 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
1127 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
1128 get_expr_operands (stmt, &TREE_OPERAND (expr, 3), opf_none);
1136 unsigned HOST_WIDE_INT offset, size;
1137 /* This component ref becomes an access to all of the subvariables
1138 it can touch, if we can determine that, but *NOT* the real one.
1139 If we can't determine which fields we could touch, the recursion
1140 will eventually get to a variable and add *all* of its subvars, or
1141 whatever is the minimum correct subset. */
1143 ref = okay_component_ref_for_subvars (expr, &offset, &size);
1146 subvar_t svars = get_subvars_for_var (ref);
1148 for (sv = svars; sv; sv = sv->next)
1151 if (overlap_subvar (offset, size, sv, &exact))
1153 int subvar_flags = flags;
1155 subvar_flags &= ~opf_kill_def;
1156 add_stmt_operand (&sv->var, s_ann, subvar_flags);
1161 get_expr_operands (stmt, &TREE_OPERAND (expr, 0),
1162 flags & ~opf_kill_def);
1164 if (code == COMPONENT_REF)
1166 if (s_ann && TREE_THIS_VOLATILE (TREE_OPERAND (expr, 1)))
1167 s_ann->has_volatile_ops = true;
1168 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
1172 case WITH_SIZE_EXPR:
1173 /* WITH_SIZE_EXPR is a pass-through reference to its first argument,
1174 and an rvalue reference to its second argument. */
1175 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
1176 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
1180 get_call_expr_operands (stmt, expr);
1185 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none);
1186 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
1187 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
1195 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
1197 op = TREE_OPERAND (expr, 0);
1198 if (TREE_CODE (op) == WITH_SIZE_EXPR)
1199 op = TREE_OPERAND (expr, 0);
1200 if (TREE_CODE (op) == ARRAY_REF
1201 || TREE_CODE (op) == ARRAY_RANGE_REF
1202 || TREE_CODE (op) == REALPART_EXPR
1203 || TREE_CODE (op) == IMAGPART_EXPR)
1204 subflags = opf_is_def;
1206 subflags = opf_is_def | opf_kill_def;
1208 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), subflags);
1214 /* General aggregate CONSTRUCTORs have been decomposed, but they
1215 are still in use as the COMPLEX_EXPR equivalent for vectors. */
1216 constructor_elt *ce;
1217 unsigned HOST_WIDE_INT idx;
1220 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (expr), idx, ce);
1222 get_expr_operands (stmt, &ce->value, opf_none);
1227 case TRUTH_NOT_EXPR:
1229 case VIEW_CONVERT_EXPR:
1231 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
1234 case TRUTH_AND_EXPR:
1236 case TRUTH_XOR_EXPR:
1242 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
1243 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
1247 case REALIGN_LOAD_EXPR:
1249 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
1250 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
1251 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), flags);
1260 /* Expressions that make no memory references. */
1264 if (class == tcc_unary)
1266 if (class == tcc_binary || class == tcc_comparison)
1268 if (class == tcc_constant || class == tcc_type)
1272 /* If we get here, something has gone wrong. */
1273 #ifdef ENABLE_CHECKING
1274 fprintf (stderr, "unhandled expression in get_expr_operands():\n");
1276 fputs ("\n", stderr);
1277 internal_error ("internal error");
1283 /* Scan operands in the ASM_EXPR stmt referred to in INFO. */
1286 get_asm_expr_operands (tree stmt)
1288 stmt_ann_t s_ann = stmt_ann (stmt);
1289 int noutputs = list_length (ASM_OUTPUTS (stmt));
1290 const char **oconstraints
1291 = (const char **) alloca ((noutputs) * sizeof (const char *));
1294 const char *constraint;
1295 bool allows_mem, allows_reg, is_inout;
1297 for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link))
1299 oconstraints[i] = constraint
1300 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
1301 parse_output_constraint (&constraint, i, 0, 0,
1302 &allows_mem, &allows_reg, &is_inout);
1304 /* This should have been split in gimplify_asm_expr. */
1305 gcc_assert (!allows_reg || !is_inout);
1307 /* Memory operands are addressable. Note that STMT needs the
1308 address of this operand. */
1309 if (!allows_reg && allows_mem)
1311 tree t = get_base_address (TREE_VALUE (link));
1312 if (t && DECL_P (t) && s_ann)
1313 add_to_addressable_set (t, &s_ann->addresses_taken);
1316 get_expr_operands (stmt, &TREE_VALUE (link), opf_is_def);
1319 for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
1322 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
1323 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
1324 oconstraints, &allows_mem, &allows_reg);
1326 /* Memory operands are addressable. Note that STMT needs the
1327 address of this operand. */
1328 if (!allows_reg && allows_mem)
1330 tree t = get_base_address (TREE_VALUE (link));
1331 if (t && DECL_P (t) && s_ann)
1332 add_to_addressable_set (t, &s_ann->addresses_taken);
1335 get_expr_operands (stmt, &TREE_VALUE (link), 0);
1339 /* Clobber memory for asm ("" : : : "memory"); */
1340 for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link))
1341 if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
1346 /* Clobber all call-clobbered variables (or .GLOBAL_VAR if we
1347 decided to group them). */
1349 add_stmt_operand (&global_var, s_ann, opf_is_def);
1351 EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi)
1353 tree var = referenced_var (i);
1354 add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
1357 /* Now clobber all addressables. */
1358 EXECUTE_IF_SET_IN_BITMAP (addressable_vars, 0, i, bi)
1360 tree var = referenced_var (i);
1362 /* Subvars are explicitly represented in this list, so
1363 we don't need the original to be added to the clobber
1364 ops, but the original *will* be in this list because
1365 we keep the addressability of the original
1366 variable up-to-date so we don't screw up the rest of
1368 if (var_can_have_subvars (var)
1369 && get_subvars_for_var (var) != NULL)
1372 add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
1379 /* A subroutine of get_expr_operands to handle INDIRECT_REF,
1380 ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF. */
1383 get_indirect_ref_operands (tree stmt, tree expr, int flags)
1385 tree *pptr = &TREE_OPERAND (expr, 0);
1387 stmt_ann_t s_ann = stmt_ann (stmt);
1389 /* Stores into INDIRECT_REF operands are never killing definitions. */
1390 flags &= ~opf_kill_def;
1392 if (SSA_VAR_P (ptr))
1394 struct ptr_info_def *pi = NULL;
1396 /* If PTR has flow-sensitive points-to information, use it. */
1397 if (TREE_CODE (ptr) == SSA_NAME
1398 && (pi = SSA_NAME_PTR_INFO (ptr)) != NULL
1399 && pi->name_mem_tag)
1401 /* PTR has its own memory tag. Use it. */
1402 add_stmt_operand (&pi->name_mem_tag, s_ann, flags);
1406 /* If PTR is not an SSA_NAME or it doesn't have a name
1407 tag, use its type memory tag. */
1410 /* If we are emitting debugging dumps, display a warning if
1411 PTR is an SSA_NAME with no flow-sensitive alias
1412 information. That means that we may need to compute
1415 && TREE_CODE (ptr) == SSA_NAME
1419 "NOTE: no flow-sensitive alias info for ");
1420 print_generic_expr (dump_file, ptr, dump_flags);
1421 fprintf (dump_file, " in ");
1422 print_generic_stmt (dump_file, stmt, dump_flags);
1425 if (TREE_CODE (ptr) == SSA_NAME)
1426 ptr = SSA_NAME_VAR (ptr);
1427 v_ann = var_ann (ptr);
1428 if (v_ann->type_mem_tag)
1429 add_stmt_operand (&v_ann->type_mem_tag, s_ann, flags);
1433 /* If a constant is used as a pointer, we can't generate a real
1434 operand for it but we mark the statement volatile to prevent
1435 optimizations from messing things up. */
1436 else if (TREE_CODE (ptr) == INTEGER_CST)
1439 s_ann->has_volatile_ops = true;
1443 /* Everything else *should* have been folded elsewhere, but users
1444 are smarter than we in finding ways to write invalid code. We
1445 cannot just assert here. If we were absolutely certain that we
1446 do handle all valid cases, then we could just do nothing here.
1447 That seems optimistic, so attempt to do something logical... */
1448 else if ((TREE_CODE (ptr) == PLUS_EXPR || TREE_CODE (ptr) == MINUS_EXPR)
1449 && TREE_CODE (TREE_OPERAND (ptr, 0)) == ADDR_EXPR
1450 && TREE_CODE (TREE_OPERAND (ptr, 1)) == INTEGER_CST)
1452 /* Make sure we know the object is addressable. */
1453 pptr = &TREE_OPERAND (ptr, 0);
1454 add_stmt_operand (pptr, s_ann, 0);
1456 /* Mark the object itself with a VUSE. */
1457 pptr = &TREE_OPERAND (*pptr, 0);
1458 get_expr_operands (stmt, pptr, flags);
1462 /* Ok, this isn't even is_gimple_min_invariant. Something's broke. */
1466 /* Add a USE operand for the base pointer. */
1467 get_expr_operands (stmt, pptr, opf_none);
1470 /* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */
1473 get_tmr_operands (tree stmt, tree expr, int flags)
1475 tree tag = TMR_TAG (expr);
1477 /* First record the real operands. */
1478 get_expr_operands (stmt, &TMR_BASE (expr), opf_none);
1479 get_expr_operands (stmt, &TMR_INDEX (expr), opf_none);
1481 /* MEM_REFs should never be killing. */
1482 flags &= ~opf_kill_def;
1484 if (TMR_SYMBOL (expr))
1486 stmt_ann_t ann = stmt_ann (stmt);
1487 add_to_addressable_set (TMR_SYMBOL (expr), &ann->addresses_taken);
1491 get_expr_operands (stmt, &tag, flags);
1493 /* Something weird, so ensure that we will be careful. */
1494 stmt_ann (stmt)->has_volatile_ops = true;
1497 /* A subroutine of get_expr_operands to handle CALL_EXPR. */
1500 get_call_expr_operands (tree stmt, tree expr)
1503 int call_flags = call_expr_flags (expr);
1505 /* If aliases have been computed already, add V_MAY_DEF or V_USE
1506 operands for all the symbols that have been found to be
1509 Note that if aliases have not been computed, the global effects
1510 of calls will not be included in the SSA web. This is fine
1511 because no optimizer should run before aliases have been
1512 computed. By not bothering with virtual operands for CALL_EXPRs
1513 we avoid adding superfluous virtual operands, which can be a
1514 significant compile time sink (See PR 15855). */
1515 if (aliases_computed_p
1516 && !bitmap_empty_p (call_clobbered_vars)
1517 && !(call_flags & ECF_NOVOPS))
1519 /* A 'pure' or a 'const' function never call-clobbers anything.
1520 A 'noreturn' function might, but since we don't return anyway
1521 there is no point in recording that. */
1522 if (TREE_SIDE_EFFECTS (expr)
1523 && !(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN)))
1524 add_call_clobber_ops (stmt, get_callee_fndecl (expr));
1525 else if (!(call_flags & ECF_CONST))
1526 add_call_read_ops (stmt);
1529 /* Find uses in the called function. */
1530 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none);
1532 for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op))
1533 get_expr_operands (stmt, &TREE_VALUE (op), opf_none);
1535 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
1540 /* Add *VAR_P to the appropriate operand array for INFO. FLAGS is as in
1541 get_expr_operands. If *VAR_P is a GIMPLE register, it will be added to
1542 the statement's real operands, otherwise it is added to virtual
1546 add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags)
1555 /* If the operand is an ADDR_EXPR, add its operand to the list of
1556 variables that have had their address taken in this statement. */
1557 if (TREE_CODE (var) == ADDR_EXPR && s_ann)
1559 add_to_addressable_set (TREE_OPERAND (var, 0), &s_ann->addresses_taken);
1563 /* If the original variable is not a scalar, it will be added to the list
1564 of virtual operands. In that case, use its base symbol as the virtual
1565 variable representing it. */
1566 is_real_op = is_gimple_reg (var);
1567 if (!is_real_op && !DECL_P (var))
1568 var = get_virtual_var (var);
1570 /* If VAR is not a variable that we care to optimize, do nothing. */
1571 if (var == NULL_TREE || !SSA_VAR_P (var))
1574 sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
1575 v_ann = var_ann (sym);
1577 /* Mark statements with volatile operands. Optimizers should back
1578 off from statements having volatile operands. */
1579 if (TREE_THIS_VOLATILE (sym) && s_ann)
1580 s_ann->has_volatile_ops = true;
1582 /* If the variable cannot be modified and this is a V_MAY_DEF change
1583 it into a VUSE. This happens when read-only variables are marked
1584 call-clobbered and/or aliased to writable variables. So we only
1585 check that this only happens on non-specific stores.
1587 Note that if this is a specific store, i.e. associated with a
1588 modify_expr, then we can't suppress the V_DEF, lest we run into
1589 validation problems.
1591 This can happen when programs cast away const, leaving us with a
1592 store to read-only memory. If the statement is actually executed
1593 at runtime, then the program is ill formed. If the statement is
1594 not executed then all is well. At the very least, we cannot ICE. */
1595 if ((flags & opf_non_specific) && unmodifiable_var_p (var))
1597 gcc_assert (!is_real_op);
1598 flags &= ~(opf_is_def | opf_kill_def);
1603 /* The variable is a GIMPLE register. Add it to real operands. */
1604 if (flags & opf_is_def)
1611 varray_type aliases;
1613 /* The variable is not a GIMPLE register. Add it (or its aliases) to
1614 virtual operands, unless the caller has specifically requested
1615 not to add virtual operands (used when adding operands inside an
1616 ADDR_EXPR expression). */
1617 if (flags & opf_no_vops)
1620 aliases = v_ann->may_aliases;
1622 if (aliases == NULL)
1624 /* The variable is not aliased or it is an alias tag. */
1625 if (flags & opf_is_def)
1627 if (flags & opf_kill_def)
1629 /* Only regular variables or struct fields may get a
1630 V_MUST_DEF operand. */
1631 gcc_assert (!MTAG_P (var)
1632 || TREE_CODE (var) == STRUCT_FIELD_TAG);
1633 /* V_MUST_DEF for non-aliased, non-GIMPLE register
1634 variable definitions. */
1635 append_v_must_def (var);
1639 /* Add a V_MAY_DEF for call-clobbered variables and
1641 append_v_may_def (var);
1647 if (s_ann && v_ann->is_alias_tag)
1648 s_ann->makes_aliased_loads = 1;
1655 /* The variable is aliased. Add its aliases to the virtual
1657 gcc_assert (VARRAY_ACTIVE_SIZE (aliases) != 0);
1659 if (flags & opf_is_def)
1661 /* If the variable is also an alias tag, add a virtual
1662 operand for it, otherwise we will miss representing
1663 references to the members of the variable's alias set.
1664 This fixes the bug in gcc.c-torture/execute/20020503-1.c. */
1665 if (v_ann->is_alias_tag)
1666 append_v_may_def (var);
1668 for (i = 0; i < VARRAY_ACTIVE_SIZE (aliases); i++)
1669 append_v_may_def (VARRAY_TREE (aliases, i));
1672 s_ann->makes_aliased_stores = 1;
1676 /* Similarly, append a virtual uses for VAR itself, when
1677 it is an alias tag. */
1678 if (v_ann->is_alias_tag)
1681 for (i = 0; i < VARRAY_ACTIVE_SIZE (aliases); i++)
1682 append_vuse (VARRAY_TREE (aliases, i));
1685 s_ann->makes_aliased_loads = 1;
1692 /* Add the base address of REF to the set *ADDRESSES_TAKEN. If
1693 *ADDRESSES_TAKEN is NULL, a new set is created. REF may be
1694 a single variable whose address has been taken or any other valid
1695 GIMPLE memory reference (structure reference, array, etc). If the
1696 base address of REF is a decl that has sub-variables, also add all
1697 of its sub-variables. */
1700 add_to_addressable_set (tree ref, bitmap *addresses_taken)
1705 gcc_assert (addresses_taken);
1707 /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF
1708 as the only thing we take the address of. If VAR is a structure,
1709 taking the address of a field means that the whole structure may
1710 be referenced using pointer arithmetic. See PR 21407 and the
1711 ensuing mailing list discussion. */
1712 var = get_base_address (ref);
1713 if (var && SSA_VAR_P (var))
1715 if (*addresses_taken == NULL)
1716 *addresses_taken = BITMAP_GGC_ALLOC ();
1718 if (var_can_have_subvars (var)
1719 && (svars = get_subvars_for_var (var)))
1722 for (sv = svars; sv; sv = sv->next)
1724 bitmap_set_bit (*addresses_taken, DECL_UID (sv->var));
1725 TREE_ADDRESSABLE (sv->var) = 1;
1730 bitmap_set_bit (*addresses_taken, DECL_UID (var));
1731 TREE_ADDRESSABLE (var) = 1;
1737 /* Add clobbering definitions for .GLOBAL_VAR or for each of the call
1738 clobbered variables in the function. */
1741 add_call_clobber_ops (tree stmt, tree callee)
1746 stmt_ann_t s_ann = stmt_ann (stmt);
1747 struct stmt_ann_d empty_ann;
1748 bitmap not_read_b, not_written_b;
1750 /* Functions that are not const, pure or never return may clobber
1751 call-clobbered variables. */
1753 s_ann->makes_clobbering_call = true;
1755 /* If we created .GLOBAL_VAR earlier, just use it. See compute_may_aliases
1756 for the heuristic used to decide whether to create .GLOBAL_VAR or not. */
1759 add_stmt_operand (&global_var, s_ann, opf_is_def);
1763 /* FIXME - if we have better information from the static vars
1764 analysis, we need to make the cache call site specific. This way
1765 we can have the performance benefits even if we are doing good
1768 /* Get info for local and module level statics. There is a bit
1769 set for each static if the call being processed does not read
1770 or write that variable. */
1772 not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
1773 not_written_b = callee ? ipa_reference_get_not_written_global (callee) : NULL;
1775 /* If cache is valid, copy the elements into the build vectors. */
1776 if (ssa_call_clobbered_cache_valid
1777 && (!not_read_b || bitmap_empty_p (not_read_b))
1778 && (!not_written_b || bitmap_empty_p (not_written_b)))
1780 for (u = 0 ; u < VEC_length (tree, clobbered_vuses); u++)
1782 t = VEC_index (tree, clobbered_vuses, u);
1783 gcc_assert (TREE_CODE (t) != SSA_NAME);
1784 var_ann (t)->in_vuse_list = 1;
1785 VEC_safe_push (tree, heap, build_vuses, (tree)t);
1787 for (u = 0; u < VEC_length (tree, clobbered_v_may_defs); u++)
1789 t = VEC_index (tree, clobbered_v_may_defs, u);
1790 gcc_assert (TREE_CODE (t) != SSA_NAME);
1791 var_ann (t)->in_v_may_def_list = 1;
1792 VEC_safe_push (tree, heap, build_v_may_defs, (tree)t);
1796 s_ann->makes_aliased_loads = clobbered_aliased_loads;
1797 s_ann->makes_aliased_stores = clobbered_aliased_stores;
1802 memset (&empty_ann, 0, sizeof (struct stmt_ann_d));
1804 /* Add a V_MAY_DEF operand for every call clobbered variable. */
1805 EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
1807 tree var = referenced_var (u);
1808 if (unmodifiable_var_p (var))
1809 add_stmt_operand (&var, &empty_ann, opf_none);
1813 = not_read_b ? bitmap_bit_p (not_read_b, u) : false;
1815 = not_written_b ? bitmap_bit_p (not_written_b, u) : false;
1820 add_stmt_operand (&var, &empty_ann, opf_none);
1823 add_stmt_operand (&var, &empty_ann, opf_is_def);
1827 if ((!not_read_b || bitmap_empty_p (not_read_b))
1828 && (!not_written_b || bitmap_empty_p (not_written_b)))
1830 clobbered_aliased_loads = empty_ann.makes_aliased_loads;
1831 clobbered_aliased_stores = empty_ann.makes_aliased_stores;
1833 /* Set the flags for a stmt's annotation. */
1836 s_ann->makes_aliased_loads = empty_ann.makes_aliased_loads;
1837 s_ann->makes_aliased_stores = empty_ann.makes_aliased_stores;
1840 /* Prepare empty cache vectors. */
1841 VEC_truncate (tree, clobbered_vuses, 0);
1842 VEC_truncate (tree, clobbered_v_may_defs, 0);
1844 /* Now fill the clobbered cache with the values that have been found. */
1845 for (u = 0; u < VEC_length (tree, build_vuses); u++)
1846 VEC_safe_push (tree, heap, clobbered_vuses,
1847 VEC_index (tree, build_vuses, u));
1849 gcc_assert (VEC_length (tree, build_vuses)
1850 == VEC_length (tree, clobbered_vuses));
1852 for (u = 0; u < VEC_length (tree, build_v_may_defs); u++)
1853 VEC_safe_push (tree, heap, clobbered_v_may_defs,
1854 VEC_index (tree, build_v_may_defs, u));
1856 gcc_assert (VEC_length (tree, build_v_may_defs)
1857 == VEC_length (tree, clobbered_v_may_defs));
1859 ssa_call_clobbered_cache_valid = true;
1864 /* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the
1868 add_call_read_ops (tree stmt)
1873 stmt_ann_t s_ann = stmt_ann (stmt);
1874 struct stmt_ann_d empty_ann;
1876 /* if the function is not pure, it may reference memory. Add
1877 a VUSE for .GLOBAL_VAR if it has been created. See add_referenced_var
1878 for the heuristic used to decide whether to create .GLOBAL_VAR. */
1881 add_stmt_operand (&global_var, s_ann, opf_none);
1885 /* If cache is valid, copy the elements into the build vector. */
1886 if (ssa_ro_call_cache_valid)
1888 for (u = 0; u < VEC_length (tree, ro_call_vuses); u++)
1890 t = VEC_index (tree, ro_call_vuses, u);
1891 gcc_assert (TREE_CODE (t) != SSA_NAME);
1892 var_ann (t)->in_vuse_list = 1;
1893 VEC_safe_push (tree, heap, build_vuses, (tree)t);
1896 s_ann->makes_aliased_loads = ro_call_aliased_loads;
1900 memset (&empty_ann, 0, sizeof (struct stmt_ann_d));
1902 /* Add a VUSE for each call-clobbered variable. */
1903 EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
1905 tree var = referenced_var (u);
1906 add_stmt_operand (&var, &empty_ann, opf_none | opf_non_specific);
1909 ro_call_aliased_loads = empty_ann.makes_aliased_loads;
1911 s_ann->makes_aliased_loads = empty_ann.makes_aliased_loads;
1913 /* Prepare empty cache vectors. */
1914 VEC_truncate (tree, ro_call_vuses, 0);
1916 /* Now fill the clobbered cache with the values that have been found. */
1917 for (u = 0; u < VEC_length (tree, build_vuses); u++)
1918 VEC_safe_push (tree, heap, ro_call_vuses,
1919 VEC_index (tree, build_vuses, u));
1921 gcc_assert (VEC_length (tree, build_vuses)
1922 == VEC_length (tree, ro_call_vuses));
1924 ssa_ro_call_cache_valid = true;
1928 /* Scan the immediate_use list for VAR making sure its linked properly.
1929 return RTUE iof there is a problem. */
1932 verify_imm_links (FILE *f, tree var)
1934 use_operand_p ptr, prev, list;
1937 gcc_assert (TREE_CODE (var) == SSA_NAME);
1939 list = &(SSA_NAME_IMM_USE_NODE (var));
1940 gcc_assert (list->use == NULL);
1942 if (list->prev == NULL)
1944 gcc_assert (list->next == NULL);
1950 for (ptr = list->next; ptr != list; )
1952 if (prev != ptr->prev)
1955 if (ptr->use == NULL)
1956 goto error; /* 2 roots, or SAFE guard node. */
1957 else if (*(ptr->use) != var)
1962 /* Avoid infinite loops. 50,000,000 uses probably indicates a problem. */
1963 if (count++ > 50000000)
1967 /* Verify list in the other direction. */
1969 for (ptr = list->prev; ptr != list; )
1971 if (prev != ptr->next)
1985 if (ptr->stmt && stmt_modified_p (ptr->stmt))
1987 fprintf (f, " STMT MODIFIED. - <%p> ", (void *)ptr->stmt);
1988 print_generic_stmt (f, ptr->stmt, TDF_SLIM);
1990 fprintf (f, " IMM ERROR : (use_p : tree - %p:%p)", (void *)ptr,
1992 print_generic_expr (f, USE_FROM_PTR (ptr), TDF_SLIM);
1998 /* Dump all the immediate uses to FILE. */
2001 dump_immediate_uses_for (FILE *file, tree var)
2003 imm_use_iterator iter;
2004 use_operand_p use_p;
2006 gcc_assert (var && TREE_CODE (var) == SSA_NAME);
2008 print_generic_expr (file, var, TDF_SLIM);
2009 fprintf (file, " : -->");
2010 if (has_zero_uses (var))
2011 fprintf (file, " no uses.\n");
2013 if (has_single_use (var))
2014 fprintf (file, " single use.\n");
2016 fprintf (file, "%d uses.\n", num_imm_uses (var));
2018 FOR_EACH_IMM_USE_FAST (use_p, iter, var)
2020 if (!is_gimple_reg (USE_FROM_PTR (use_p)))
2021 print_generic_stmt (file, USE_STMT (use_p), TDF_VOPS);
2023 print_generic_stmt (file, USE_STMT (use_p), TDF_SLIM);
2025 fprintf(file, "\n");
2028 /* Dump all the immediate uses to FILE. */
2031 dump_immediate_uses (FILE *file)
2036 fprintf (file, "Immediate_uses: \n\n");
2037 for (x = 1; x < num_ssa_names; x++)
2042 dump_immediate_uses_for (file, var);
2047 /* Dump def-use edges on stderr. */
2050 debug_immediate_uses (void)
2052 dump_immediate_uses (stderr);
2055 /* Dump def-use edges on stderr. */
2058 debug_immediate_uses_for (tree var)
2060 dump_immediate_uses_for (stderr, var);
2062 #include "gt-tree-ssa-operands.h"