1 /* SSA operands management for trees.
2 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
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 4 of these routines, each representing one of the
57 4 types of operands. Defs, Uses, Virtual Uses, and Virtual May Defs.
59 The append_* routines check for duplication, and simply keep a list of
60 unique objects for each operand type in the build_* extendable vectors.
62 Once the stmt tree is completely parsed, the finalize_ssa_operands()
63 routine is called, which proceeds to perform the finalization routine
64 on each of the 4 operand vectors which have been built up.
66 If the stmt had a previous operand cache, the finalization routines
67 attempt to match up the new operands with the old ones. If it's a perfect
68 match, the old vector is simply reused. If it isn't a perfect match, then
69 a new vector is created and the new operands are placed there. For
70 virtual operands, if the previous cache had SSA_NAME version of a
71 variable, and that same variable occurs in the same operands cache, then
72 the new cache vector will also get the same SSA_NAME.
74 i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new
75 operand vector for VUSE, then the new vector will also be modified
76 such that it contains 'a_5' rather than 'a'. */
78 /* Structure storing statistics on how many call clobbers we have, and
79 how many where avoided. */
83 /* Number of call-clobbered ops we attempt to add to calls in
84 add_call_clobbered_mem_symbols. */
85 unsigned int clobbered_vars;
87 /* Number of write-clobbers (VDEFs) avoided by using
88 not_written information. */
89 unsigned int static_write_clobbers_avoided;
91 /* Number of reads (VUSEs) avoided by using not_read information. */
92 unsigned int static_read_clobbers_avoided;
94 /* Number of write-clobbers avoided because the variable can't escape to
96 unsigned int unescapable_clobbers_avoided;
98 /* Number of read-only uses we attempt to add to calls in
99 add_call_read_mem_symbols. */
100 unsigned int readonly_clobbers;
102 /* Number of read-only uses we avoid using not_read information. */
103 unsigned int static_readonly_clobbers_avoided;
107 /* Flags to describe operand properties in helpers. */
109 /* By default, operands are loaded. */
112 /* Operand is the target of an assignment expression or a
113 call-clobbered variable. */
114 #define opf_def (1 << 0)
116 /* No virtual operands should be created in the expression. This is used
117 when traversing ADDR_EXPR nodes which have different semantics than
118 other expressions. Inside an ADDR_EXPR node, the only operands that we
119 need to consider are indices into arrays. For instance, &a.b[i] should
120 generate a USE of 'i' but it should not generate a VUSE for 'a' nor a
122 #define opf_no_vops (1 << 1)
124 /* Operand is an implicit reference. This is used to distinguish
125 explicit assignments in the form of MODIFY_EXPR from
126 clobbering sites like function calls or ASM_EXPRs. */
127 #define opf_implicit (1 << 2)
129 /* Array for building all the def operands. */
130 static VEC(tree,heap) *build_defs;
132 /* Array for building all the use operands. */
133 static VEC(tree,heap) *build_uses;
135 /* The built VDEF operand. */
136 static tree build_vdef;
138 /* The built VUSE operand. */
139 static tree build_vuse;
141 /* Bitmap obstack for our datastructures that needs to survive across
142 compilations of multiple functions. */
143 static bitmap_obstack operands_bitmap_obstack;
145 static void get_expr_operands (gimple, tree *, int);
147 /* Number of functions with initialized ssa_operands. */
148 static int n_initialized = 0;
150 /* Return the DECL_UID of the base variable of T. */
152 static inline unsigned
153 get_name_decl (const_tree t)
155 if (TREE_CODE (t) != SSA_NAME)
158 return DECL_UID (SSA_NAME_VAR (t));
162 /* Return true if the SSA operands cache is active. */
165 ssa_operands_active (void)
167 /* This function may be invoked from contexts where CFUN is NULL
168 (IPA passes), return false for now. FIXME: operands may be
169 active in each individual function, maybe this function should
170 take CFUN as a parameter. */
174 return cfun->gimple_df && gimple_ssa_operands (cfun)->ops_active;
178 /* Create the VOP variable, an artificial global variable to act as a
179 representative of all of the virtual operands FUD chain. */
182 create_vop_var (void)
186 gcc_assert (cfun->gimple_df->vop == NULL_TREE);
188 global_var = build_decl (VAR_DECL, get_identifier (".MEM"),
190 DECL_ARTIFICIAL (global_var) = 1;
191 TREE_READONLY (global_var) = 0;
192 DECL_EXTERNAL (global_var) = 1;
193 TREE_STATIC (global_var) = 1;
194 TREE_USED (global_var) = 1;
195 DECL_CONTEXT (global_var) = NULL_TREE;
196 TREE_THIS_VOLATILE (global_var) = 0;
197 TREE_ADDRESSABLE (global_var) = 0;
199 create_var_ann (global_var);
200 add_referenced_var (global_var);
201 cfun->gimple_df->vop = global_var;
204 /* These are the sizes of the operand memory buffer in bytes which gets
205 allocated each time more operands space is required. The final value is
206 the amount that is allocated every time after that.
207 In 1k we can fit 25 use operands (or 63 def operands) on a host with
208 8 byte pointers, that would be 10 statements each with 1 def and 2
211 #define OP_SIZE_INIT 0
212 #define OP_SIZE_1 (1024 - sizeof (void *))
213 #define OP_SIZE_2 (1024 * 4 - sizeof (void *))
214 #define OP_SIZE_3 (1024 * 16 - sizeof (void *))
216 /* Initialize the operand cache routines. */
219 init_ssa_operands (void)
221 if (!n_initialized++)
223 build_defs = VEC_alloc (tree, heap, 5);
224 build_uses = VEC_alloc (tree, heap, 10);
225 build_vuse = NULL_TREE;
226 build_vdef = NULL_TREE;
227 bitmap_obstack_initialize (&operands_bitmap_obstack);
230 gcc_assert (gimple_ssa_operands (cfun)->operand_memory == NULL);
231 gimple_ssa_operands (cfun)->operand_memory_index
232 = gimple_ssa_operands (cfun)->ssa_operand_mem_size;
233 gimple_ssa_operands (cfun)->ops_active = true;
234 memset (&clobber_stats, 0, sizeof (clobber_stats));
235 gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_INIT;
240 /* Dispose of anything required by the operand routines. */
243 fini_ssa_operands (void)
245 struct ssa_operand_memory_d *ptr;
247 if (!--n_initialized)
249 VEC_free (tree, heap, build_defs);
250 VEC_free (tree, heap, build_uses);
251 build_vdef = NULL_TREE;
252 build_vuse = NULL_TREE;
255 gimple_ssa_operands (cfun)->free_defs = NULL;
256 gimple_ssa_operands (cfun)->free_uses = NULL;
258 while ((ptr = gimple_ssa_operands (cfun)->operand_memory) != NULL)
260 gimple_ssa_operands (cfun)->operand_memory
261 = gimple_ssa_operands (cfun)->operand_memory->next;
265 gimple_ssa_operands (cfun)->ops_active = false;
268 bitmap_obstack_release (&operands_bitmap_obstack);
270 cfun->gimple_df->vop = NULL_TREE;
272 if (dump_file && (dump_flags & TDF_STATS))
274 fprintf (dump_file, "Original clobbered vars: %d\n",
275 clobber_stats.clobbered_vars);
276 fprintf (dump_file, "Static write clobbers avoided: %d\n",
277 clobber_stats.static_write_clobbers_avoided);
278 fprintf (dump_file, "Static read clobbers avoided: %d\n",
279 clobber_stats.static_read_clobbers_avoided);
280 fprintf (dump_file, "Unescapable clobbers avoided: %d\n",
281 clobber_stats.unescapable_clobbers_avoided);
282 fprintf (dump_file, "Original read-only clobbers: %d\n",
283 clobber_stats.readonly_clobbers);
284 fprintf (dump_file, "Static read-only clobbers avoided: %d\n",
285 clobber_stats.static_readonly_clobbers_avoided);
290 /* Return memory for an operand of size SIZE. */
293 ssa_operand_alloc (unsigned size)
297 gcc_assert (size == sizeof (struct use_optype_d)
298 || size == sizeof (struct def_optype_d));
300 if (gimple_ssa_operands (cfun)->operand_memory_index + size
301 >= gimple_ssa_operands (cfun)->ssa_operand_mem_size)
303 struct ssa_operand_memory_d *ptr;
305 switch (gimple_ssa_operands (cfun)->ssa_operand_mem_size)
308 gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_1;
311 gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_2;
315 gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_3;
321 ptr = (struct ssa_operand_memory_d *)
322 ggc_alloc (sizeof (void *)
323 + gimple_ssa_operands (cfun)->ssa_operand_mem_size);
324 ptr->next = gimple_ssa_operands (cfun)->operand_memory;
325 gimple_ssa_operands (cfun)->operand_memory = ptr;
326 gimple_ssa_operands (cfun)->operand_memory_index = 0;
329 ptr = &(gimple_ssa_operands (cfun)->operand_memory
330 ->mem[gimple_ssa_operands (cfun)->operand_memory_index]);
331 gimple_ssa_operands (cfun)->operand_memory_index += size;
336 /* Allocate a DEF operand. */
338 static inline struct def_optype_d *
341 struct def_optype_d *ret;
342 if (gimple_ssa_operands (cfun)->free_defs)
344 ret = gimple_ssa_operands (cfun)->free_defs;
345 gimple_ssa_operands (cfun)->free_defs
346 = gimple_ssa_operands (cfun)->free_defs->next;
349 ret = (struct def_optype_d *)
350 ssa_operand_alloc (sizeof (struct def_optype_d));
355 /* Allocate a USE operand. */
357 static inline struct use_optype_d *
360 struct use_optype_d *ret;
361 if (gimple_ssa_operands (cfun)->free_uses)
363 ret = gimple_ssa_operands (cfun)->free_uses;
364 gimple_ssa_operands (cfun)->free_uses
365 = gimple_ssa_operands (cfun)->free_uses->next;
368 ret = (struct use_optype_d *)
369 ssa_operand_alloc (sizeof (struct use_optype_d));
374 /* Adds OP to the list of defs after LAST. */
376 static inline def_optype_p
377 add_def_op (tree *op, def_optype_p last)
379 def_optype_p new_def;
381 new_def = alloc_def ();
382 DEF_OP_PTR (new_def) = op;
383 last->next = new_def;
384 new_def->next = NULL;
389 /* Adds OP to the list of uses of statement STMT after LAST. */
391 static inline use_optype_p
392 add_use_op (gimple stmt, tree *op, use_optype_p last)
394 use_optype_p new_use;
396 new_use = alloc_use ();
397 USE_OP_PTR (new_use)->use = op;
398 link_imm_use_stmt (USE_OP_PTR (new_use), *op, stmt);
399 last->next = new_use;
400 new_use->next = NULL;
406 /* Takes elements from build_defs and turns them into def operands of STMT.
407 TODO -- Make build_defs VEC of tree *. */
410 finalize_ssa_defs (gimple stmt)
413 struct def_optype_d new_list;
414 def_optype_p old_ops, last;
415 unsigned int num = VEC_length (tree, build_defs);
417 /* There should only be a single real definition per assignment. */
418 gcc_assert ((stmt && gimple_code (stmt) != GIMPLE_ASSIGN) || num <= 1);
420 /* Pre-pend the vdef we may have built. */
421 if (build_vdef != NULL_TREE)
423 tree oldvdef = gimple_vdef (stmt);
425 && TREE_CODE (oldvdef) == SSA_NAME)
426 oldvdef = SSA_NAME_VAR (oldvdef);
427 if (oldvdef != build_vdef)
428 gimple_set_vdef (stmt, build_vdef);
429 VEC_safe_insert (tree, heap, build_defs, 0, (tree)gimple_vdef_ptr (stmt));
433 new_list.next = NULL;
436 old_ops = gimple_def_ops (stmt);
440 /* Clear and unlink a no longer necessary VDEF. */
441 if (build_vdef == NULL_TREE
442 && gimple_vdef (stmt) != NULL_TREE)
444 if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
446 unlink_stmt_vdef (stmt);
447 release_ssa_name (gimple_vdef (stmt));
449 gimple_set_vdef (stmt, NULL_TREE);
452 /* If we have a non-SSA_NAME VDEF, mark it for renaming. */
453 if (gimple_vdef (stmt)
454 && TREE_CODE (gimple_vdef (stmt)) != SSA_NAME)
455 mark_sym_for_renaming (gimple_vdef (stmt));
457 /* Check for the common case of 1 def that hasn't changed. */
458 if (old_ops && old_ops->next == NULL && num == 1
459 && (tree *) VEC_index (tree, build_defs, 0) == DEF_OP_PTR (old_ops))
462 /* If there is anything in the old list, free it. */
465 old_ops->next = gimple_ssa_operands (cfun)->free_defs;
466 gimple_ssa_operands (cfun)->free_defs = old_ops;
469 /* If there is anything remaining in the build_defs list, simply emit it. */
470 for ( ; new_i < num; new_i++)
471 last = add_def_op ((tree *) VEC_index (tree, build_defs, new_i), last);
473 /* Now set the stmt's operands. */
474 gimple_set_def_ops (stmt, new_list.next);
478 /* Takes elements from build_uses and turns them into use operands of STMT.
479 TODO -- Make build_uses VEC of tree *. */
482 finalize_ssa_uses (gimple stmt)
485 struct use_optype_d new_list;
486 use_optype_p old_ops, ptr, last;
488 /* Pre-pend the VUSE we may have built. */
489 if (build_vuse != NULL_TREE)
491 tree oldvuse = gimple_vuse (stmt);
493 && TREE_CODE (oldvuse) == SSA_NAME)
494 oldvuse = SSA_NAME_VAR (oldvuse);
495 if (oldvuse != (build_vuse != NULL_TREE
496 ? build_vuse : build_vdef))
497 gimple_set_vuse (stmt, NULL_TREE);
498 VEC_safe_insert (tree, heap, build_uses, 0, (tree)gimple_vuse_ptr (stmt));
501 new_list.next = NULL;
504 old_ops = gimple_use_ops (stmt);
506 /* Clear a no longer necessary VUSE. */
507 if (build_vuse == NULL_TREE
508 && gimple_vuse (stmt) != NULL_TREE)
509 gimple_set_vuse (stmt, NULL_TREE);
511 /* If there is anything in the old list, free it. */
514 for (ptr = old_ops; ptr; ptr = ptr->next)
515 delink_imm_use (USE_OP_PTR (ptr));
516 old_ops->next = gimple_ssa_operands (cfun)->free_uses;
517 gimple_ssa_operands (cfun)->free_uses = old_ops;
520 /* If we added a VUSE, make sure to set the operand if it is not already
521 present and mark it for renaming. */
522 if (build_vuse != NULL_TREE
523 && gimple_vuse (stmt) == NULL_TREE)
525 gimple_set_vuse (stmt, gimple_vop (cfun));
526 mark_sym_for_renaming (gimple_vop (cfun));
529 /* Now create nodes for all the new nodes. */
530 for (new_i = 0; new_i < VEC_length (tree, build_uses); new_i++)
531 last = add_use_op (stmt,
532 (tree *) VEC_index (tree, build_uses, new_i),
535 /* Now set the stmt's operands. */
536 gimple_set_use_ops (stmt, new_list.next);
540 /* Clear the in_list bits and empty the build array for VDEFs and
544 cleanup_build_arrays (void)
546 build_vdef = NULL_TREE;
547 build_vuse = NULL_TREE;
548 VEC_truncate (tree, build_defs, 0);
549 VEC_truncate (tree, build_uses, 0);
553 /* Finalize all the build vectors, fill the new ones into INFO. */
556 finalize_ssa_stmt_operands (gimple stmt)
558 finalize_ssa_defs (stmt);
559 finalize_ssa_uses (stmt);
560 cleanup_build_arrays ();
564 /* Start the process of building up operands vectors in INFO. */
567 start_ssa_stmt_operands (void)
569 gcc_assert (VEC_length (tree, build_defs) == 0);
570 gcc_assert (VEC_length (tree, build_uses) == 0);
571 gcc_assert (build_vuse == NULL_TREE);
572 gcc_assert (build_vdef == NULL_TREE);
576 /* Add DEF_P to the list of pointers to operands. */
579 append_def (tree *def_p)
581 VEC_safe_push (tree, heap, build_defs, (tree) def_p);
585 /* Add USE_P to the list of pointers to operands. */
588 append_use (tree *use_p)
590 VEC_safe_push (tree, heap, build_uses, (tree) use_p);
594 /* Add VAR to the set of variables that require a VDEF operator. */
597 append_vdef (tree var)
602 gcc_assert ((build_vdef == NULL_TREE
603 || build_vdef == var)
604 && (build_vuse == NULL_TREE
605 || build_vuse == var));
612 /* Add VAR to the set of variables that require a VUSE operator. */
615 append_vuse (tree var)
620 gcc_assert (build_vuse == NULL_TREE
621 || build_vuse == var);
626 /* Add virtual operands for STMT. FLAGS is as in get_expr_operands. */
629 add_virtual_operand (gimple stmt ATTRIBUTE_UNUSED, int flags)
631 /* Add virtual operands to the stmt, unless the caller has specifically
632 requested not to do that (used when adding operands inside an
633 ADDR_EXPR expression). */
634 if (flags & opf_no_vops)
638 append_vdef (gimple_vop (cfun));
640 append_vuse (gimple_vop (cfun));
644 /* Add *VAR_P to the appropriate operand array for statement STMT.
645 FLAGS is as in get_expr_operands. If *VAR_P is a GIMPLE register,
646 it will be added to the statement's real operands, otherwise it is
647 added to virtual operands. */
650 add_stmt_operand (tree *var_p, gimple stmt, int flags)
655 gcc_assert (SSA_VAR_P (*var_p));
658 sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
659 v_ann = var_ann (sym);
661 /* Mark statements with volatile operands. */
662 if (TREE_THIS_VOLATILE (sym))
663 gimple_set_has_volatile_ops (stmt, true);
665 if (is_gimple_reg (sym))
667 /* The variable is a GIMPLE register. Add it to real operands. */
674 add_virtual_operand (stmt, flags);
677 /* Mark the base address of REF as having its address taken.
678 REF may be a single variable whose address has been taken or any
679 other valid GIMPLE memory reference (structure reference, array,
683 mark_address_taken (tree ref)
687 /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF
688 as the only thing we take the address of. If VAR is a structure,
689 taking the address of a field means that the whole structure may
690 be referenced using pointer arithmetic. See PR 21407 and the
691 ensuing mailing list discussion. */
692 var = get_base_address (ref);
693 if (var && DECL_P (var))
694 TREE_ADDRESSABLE (var) = 1;
698 /* A subroutine of get_expr_operands to handle INDIRECT_REF,
699 ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF.
701 STMT is the statement being processed, EXPR is the INDIRECT_REF
704 FLAGS is as in get_expr_operands.
706 RECURSE_ON_BASE should be set to true if we want to continue
707 calling get_expr_operands on the base pointer, and false if
708 something else will do it for us. */
711 get_indirect_ref_operands (gimple stmt, tree expr, int flags,
712 bool recurse_on_base)
714 tree *pptr = &TREE_OPERAND (expr, 0);
716 if (TREE_THIS_VOLATILE (expr))
717 gimple_set_has_volatile_ops (stmt, true);
720 add_virtual_operand (stmt, flags);
722 /* If requested, add a USE operand for the base pointer. */
724 get_expr_operands (stmt, pptr, opf_use);
728 /* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */
731 get_tmr_operands (gimple stmt, tree expr, int flags)
733 /* First record the real operands. */
734 get_expr_operands (stmt, &TMR_BASE (expr), opf_use);
735 get_expr_operands (stmt, &TMR_INDEX (expr), opf_use);
737 if (TMR_SYMBOL (expr))
738 mark_address_taken (TMR_SYMBOL (expr));
740 add_virtual_operand (stmt, flags);
744 /* If STMT is a call that may clobber globals and other symbols that
745 escape, add them to the VDEF/VUSE lists for it. */
748 maybe_add_call_vops (gimple stmt)
750 int call_flags = gimple_call_flags (stmt);
752 /* If aliases have been computed already, add VDEF or VUSE
753 operands for all the symbols that have been found to be
755 if (!(call_flags & ECF_NOVOPS))
757 /* A 'pure' or a 'const' function never call-clobbers anything.
758 A 'noreturn' function might, but since we don't return anyway
759 there is no point in recording that. */
760 if (!(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN)))
761 add_virtual_operand (stmt, opf_def);
762 else if (!(call_flags & ECF_CONST))
763 add_virtual_operand (stmt, opf_use);
768 /* Scan operands in the ASM_EXPR stmt referred to in INFO. */
771 get_asm_expr_operands (gimple stmt)
774 const char **oconstraints;
775 const char *constraint;
776 bool allows_mem, allows_reg, is_inout;
778 noutputs = gimple_asm_noutputs (stmt);
779 oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *));
781 /* Gather all output operands. */
782 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
784 tree link = gimple_asm_output_op (stmt, i);
785 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
786 oconstraints[i] = constraint;
787 parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
788 &allows_reg, &is_inout);
790 /* This should have been split in gimplify_asm_expr. */
791 gcc_assert (!allows_reg || !is_inout);
793 /* Memory operands are addressable. Note that STMT needs the
794 address of this operand. */
795 if (!allows_reg && allows_mem)
797 tree t = get_base_address (TREE_VALUE (link));
799 mark_address_taken (t);
802 get_expr_operands (stmt, &TREE_VALUE (link), opf_def);
805 /* Gather all input operands. */
806 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
808 tree link = gimple_asm_input_op (stmt, i);
809 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
810 parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints,
811 &allows_mem, &allows_reg);
813 /* Memory operands are addressable. Note that STMT needs the
814 address of this operand. */
815 if (!allows_reg && allows_mem)
817 tree t = get_base_address (TREE_VALUE (link));
819 mark_address_taken (t);
822 get_expr_operands (stmt, &TREE_VALUE (link), 0);
825 /* Clobber all memory and addressable symbols for asm ("" : : : "memory"); */
826 for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
828 tree link = gimple_asm_clobber_op (stmt, i);
829 if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
831 add_virtual_operand (stmt, opf_def);
838 /* Recursively scan the expression pointed to by EXPR_P in statement
839 STMT. FLAGS is one of the OPF_* constants modifying how to
840 interpret the operands found. */
843 get_expr_operands (gimple stmt, tree *expr_p, int flags)
846 enum tree_code_class codeclass;
852 code = TREE_CODE (expr);
853 codeclass = TREE_CODE_CLASS (code);
858 /* Taking the address of a variable does not represent a
859 reference to it, but the fact that the statement takes its
860 address will be of interest to some passes (e.g. alias
862 mark_address_taken (TREE_OPERAND (expr, 0));
864 /* If the address is invariant, there may be no interesting
865 variable references inside. */
866 if (is_gimple_min_invariant (expr))
869 /* Otherwise, there may be variables referenced inside but there
870 should be no VUSEs created, since the referenced objects are
871 not really accessed. The only operands that we should find
872 here are ARRAY_REF indices which will always be real operands
873 (GIMPLE does not allow non-registers as array indices). */
874 flags |= opf_no_vops;
875 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
879 add_stmt_operand (expr_p, stmt, flags);
885 add_stmt_operand (expr_p, stmt, flags);
888 case MISALIGNED_INDIRECT_REF:
889 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
892 case ALIGN_INDIRECT_REF:
894 get_indirect_ref_operands (stmt, expr, flags, true);
898 get_tmr_operands (stmt, expr, flags);
902 case ARRAY_RANGE_REF:
908 HOST_WIDE_INT offset, size, maxsize;
910 if (TREE_THIS_VOLATILE (expr))
911 gimple_set_has_volatile_ops (stmt, true);
913 ref = get_ref_base_and_extent (expr, &offset, &size, &maxsize);
914 if (TREE_CODE (ref) == INDIRECT_REF)
916 get_indirect_ref_operands (stmt, ref, flags, false);
917 flags |= opf_no_vops;
920 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
922 if (code == COMPONENT_REF)
924 if (TREE_THIS_VOLATILE (TREE_OPERAND (expr, 1)))
925 gimple_set_has_volatile_ops (stmt, true);
926 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_use);
928 else if (code == ARRAY_REF || code == ARRAY_RANGE_REF)
930 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_use);
931 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_use);
932 get_expr_operands (stmt, &TREE_OPERAND (expr, 3), opf_use);
939 /* WITH_SIZE_EXPR is a pass-through reference to its first argument,
940 and an rvalue reference to its second argument. */
941 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_use);
942 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
947 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_use);
948 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_use);
949 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_use);
954 /* General aggregate CONSTRUCTORs have been decomposed, but they
955 are still in use as the COMPLEX_EXPR equivalent for vectors. */
957 unsigned HOST_WIDE_INT idx;
960 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (expr), idx, ce);
962 get_expr_operands (stmt, &ce->value, opf_use);
968 if (TREE_THIS_VOLATILE (expr))
969 gimple_set_has_volatile_ops (stmt, true);
973 case VIEW_CONVERT_EXPR:
975 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
986 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
987 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
992 case REALIGN_LOAD_EXPR:
994 get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
995 get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
996 get_expr_operands (stmt, &TREE_OPERAND (expr, 2), flags);
1003 case CASE_LABEL_EXPR:
1006 /* Expressions that make no memory references. */
1010 if (codeclass == tcc_unary)
1012 if (codeclass == tcc_binary || codeclass == tcc_comparison)
1014 if (codeclass == tcc_constant || codeclass == tcc_type)
1018 /* If we get here, something has gone wrong. */
1019 #ifdef ENABLE_CHECKING
1020 fprintf (stderr, "unhandled expression in get_expr_operands():\n");
1022 fputs ("\n", stderr);
1028 /* Parse STMT looking for operands. When finished, the various
1029 build_* operand vectors will have potential operands in them. */
1032 parse_ssa_operands (gimple stmt)
1034 enum gimple_code code = gimple_code (stmt);
1036 if (code == GIMPLE_ASM)
1037 get_asm_expr_operands (stmt);
1040 size_t i, start = 0;
1042 if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
1044 get_expr_operands (stmt, gimple_op_ptr (stmt, 0), opf_def);
1048 for (i = start; i < gimple_num_ops (stmt); i++)
1049 get_expr_operands (stmt, gimple_op_ptr (stmt, i), opf_use);
1051 /* Add call-clobbered operands, if needed. */
1052 if (code == GIMPLE_CALL)
1053 maybe_add_call_vops (stmt);
1058 /* Create an operands cache for STMT. */
1061 build_ssa_operands (gimple stmt)
1063 /* Initially assume that the statement has no volatile operands. */
1064 gimple_set_has_volatile_ops (stmt, false);
1066 start_ssa_stmt_operands ();
1067 parse_ssa_operands (stmt);
1068 finalize_ssa_stmt_operands (stmt);
1072 /* Releases the operands of STMT back to their freelists, and clears
1073 the stmt operand lists. */
1076 free_stmt_operands (gimple stmt)
1078 def_optype_p defs = gimple_def_ops (stmt), last_def;
1079 use_optype_p uses = gimple_use_ops (stmt), last_use;
1083 for (last_def = defs; last_def->next; last_def = last_def->next)
1085 last_def->next = gimple_ssa_operands (cfun)->free_defs;
1086 gimple_ssa_operands (cfun)->free_defs = defs;
1087 gimple_set_def_ops (stmt, NULL);
1092 for (last_use = uses; last_use->next; last_use = last_use->next)
1093 delink_imm_use (USE_OP_PTR (last_use));
1094 delink_imm_use (USE_OP_PTR (last_use));
1095 last_use->next = gimple_ssa_operands (cfun)->free_uses;
1096 gimple_ssa_operands (cfun)->free_uses = uses;
1097 gimple_set_use_ops (stmt, NULL);
1100 if (gimple_has_mem_ops (stmt))
1102 gimple_set_vuse (stmt, NULL_TREE);
1103 gimple_set_vdef (stmt, NULL_TREE);
1108 /* Get the operands of statement STMT. */
1111 update_stmt_operands (gimple stmt)
1113 /* If update_stmt_operands is called before SSA is initialized, do
1115 if (!ssa_operands_active ())
1118 timevar_push (TV_TREE_OPS);
1120 gcc_assert (gimple_modified_p (stmt));
1121 build_ssa_operands (stmt);
1122 gimple_set_modified (stmt, false);
1124 timevar_pop (TV_TREE_OPS);
1128 /* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done
1129 to test the validity of the swap operation. */
1132 swap_tree_operands (gimple stmt, tree *exp0, tree *exp1)
1138 /* If the operand cache is active, attempt to preserve the relative
1139 positions of these two operands in their respective immediate use
1141 if (ssa_operands_active () && op0 != op1)
1143 use_optype_p use0, use1, ptr;
1146 /* Find the 2 operands in the cache, if they are there. */
1147 for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next)
1148 if (USE_OP_PTR (ptr)->use == exp0)
1154 for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next)
1155 if (USE_OP_PTR (ptr)->use == exp1)
1161 /* If both uses don't have operand entries, there isn't much we can do
1162 at this point. Presumably we don't need to worry about it. */
1165 tree *tmp = USE_OP_PTR (use1)->use;
1166 USE_OP_PTR (use1)->use = USE_OP_PTR (use0)->use;
1167 USE_OP_PTR (use0)->use = tmp;
1171 /* Now swap the data. */
1177 /* Scan the immediate_use list for VAR making sure its linked properly.
1178 Return TRUE if there is a problem and emit an error message to F. */
1181 verify_imm_links (FILE *f, tree var)
1183 use_operand_p ptr, prev, list;
1186 gcc_assert (TREE_CODE (var) == SSA_NAME);
1188 list = &(SSA_NAME_IMM_USE_NODE (var));
1189 gcc_assert (list->use == NULL);
1191 if (list->prev == NULL)
1193 gcc_assert (list->next == NULL);
1199 for (ptr = list->next; ptr != list; )
1201 if (prev != ptr->prev)
1204 if (ptr->use == NULL)
1205 goto error; /* 2 roots, or SAFE guard node. */
1206 else if (*(ptr->use) != var)
1212 /* Avoid infinite loops. 50,000,000 uses probably indicates a
1214 if (count++ > 50000000)
1218 /* Verify list in the other direction. */
1220 for (ptr = list->prev; ptr != list; )
1222 if (prev != ptr->next)
1236 if (ptr->loc.stmt && gimple_modified_p (ptr->loc.stmt))
1238 fprintf (f, " STMT MODIFIED. - <%p> ", (void *)ptr->loc.stmt);
1239 print_gimple_stmt (f, ptr->loc.stmt, 0, TDF_SLIM);
1241 fprintf (f, " IMM ERROR : (use_p : tree - %p:%p)", (void *)ptr,
1243 print_generic_expr (f, USE_FROM_PTR (ptr), TDF_SLIM);
1249 /* Dump all the immediate uses to FILE. */
1252 dump_immediate_uses_for (FILE *file, tree var)
1254 imm_use_iterator iter;
1255 use_operand_p use_p;
1257 gcc_assert (var && TREE_CODE (var) == SSA_NAME);
1259 print_generic_expr (file, var, TDF_SLIM);
1260 fprintf (file, " : -->");
1261 if (has_zero_uses (var))
1262 fprintf (file, " no uses.\n");
1264 if (has_single_use (var))
1265 fprintf (file, " single use.\n");
1267 fprintf (file, "%d uses.\n", num_imm_uses (var));
1269 FOR_EACH_IMM_USE_FAST (use_p, iter, var)
1271 if (use_p->loc.stmt == NULL && use_p->use == NULL)
1272 fprintf (file, "***end of stmt iterator marker***\n");
1274 if (!is_gimple_reg (USE_FROM_PTR (use_p)))
1275 print_gimple_stmt (file, USE_STMT (use_p), 0, TDF_VOPS|TDF_MEMSYMS);
1277 print_gimple_stmt (file, USE_STMT (use_p), 0, TDF_SLIM);
1279 fprintf(file, "\n");
1283 /* Dump all the immediate uses to FILE. */
1286 dump_immediate_uses (FILE *file)
1291 fprintf (file, "Immediate_uses: \n\n");
1292 for (x = 1; x < num_ssa_names; x++)
1297 dump_immediate_uses_for (file, var);
1302 /* Dump def-use edges on stderr. */
1305 debug_immediate_uses (void)
1307 dump_immediate_uses (stderr);
1311 /* Dump def-use edges on stderr. */
1314 debug_immediate_uses_for (tree var)
1316 dump_immediate_uses_for (stderr, var);
1320 /* Unlink STMTs virtual definition from the IL by propagating its use. */
1323 unlink_stmt_vdef (gimple stmt)
1325 use_operand_p use_p;
1326 imm_use_iterator iter;
1328 tree vdef = gimple_vdef (stmt);
1331 || TREE_CODE (vdef) != SSA_NAME)
1334 FOR_EACH_IMM_USE_STMT (use_stmt, iter, gimple_vdef (stmt))
1336 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1337 SET_USE (use_p, gimple_vuse (stmt));
1340 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_vdef (stmt)))
1341 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_vuse (stmt)) = 1;