1 /* SSA operands management for trees.
2 Copyright (C) 2003, 2004, 2005, 2006, 2007 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 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 operand
75 vector for VUSE, then the new vector will also be modified such that
76 it contains 'a_5' rather than 'a'. */
79 /* Structure storing statistics on how many call clobbers we have, and
80 how many where avoided. */
84 /* Number of call-clobbered ops we attempt to add to calls in
85 add_call_clobbered_mem_symbols. */
86 unsigned int clobbered_vars
;
88 /* Number of write-clobbers (VDEFs) avoided by using
89 not_written information. */
90 unsigned int static_write_clobbers_avoided
;
92 /* Number of reads (VUSEs) avoided by using not_read information. */
93 unsigned int static_read_clobbers_avoided
;
95 /* Number of write-clobbers avoided because the variable can't escape to
97 unsigned int unescapable_clobbers_avoided
;
99 /* Number of read-only uses we attempt to add to calls in
100 add_call_read_mem_symbols. */
101 unsigned int readonly_clobbers
;
103 /* Number of read-only uses we avoid using not_read information. */
104 unsigned int static_readonly_clobbers_avoided
;
108 /* Flags to describe operand properties in helpers. */
110 /* By default, operands are loaded. */
113 /* Operand is the target of an assignment expression or a
114 call-clobbered variable. */
115 #define opf_def (1 << 0)
117 /* No virtual operands should be created in the expression. This is used
118 when traversing ADDR_EXPR nodes which have different semantics than
119 other expressions. Inside an ADDR_EXPR node, the only operands that we
120 need to consider are indices into arrays. For instance, &a.b[i] should
121 generate a USE of 'i' but it should not generate a VUSE for 'a' nor a
123 #define opf_no_vops (1 << 1)
125 /* Operand is an implicit reference. This is used to distinguish
126 explicit assignments in the form of GIMPLE_MODIFY_STMT from
127 clobbering sites like function calls or ASM_EXPRs. */
128 #define opf_implicit (1 << 2)
130 /* Array for building all the def operands. */
131 static VEC(tree
,heap
) *build_defs
;
133 /* Array for building all the use operands. */
134 static VEC(tree
,heap
) *build_uses
;
136 /* Set for building all the VDEF operands. */
137 static VEC(tree
,heap
) *build_vdefs
;
139 /* Set for building all the VUSE operands. */
140 static VEC(tree
,heap
) *build_vuses
;
142 /* Bitmap obstack for our datastructures that needs to survive across
143 compilations of multiple functions. */
144 static bitmap_obstack operands_bitmap_obstack
;
146 /* Set for building all the loaded symbols. */
147 static bitmap build_loads
;
149 /* Set for building all the stored symbols. */
150 static bitmap build_stores
;
152 static void get_expr_operands (tree
, tree
*, int);
154 /* Number of functions with initialized ssa_operands. */
155 static int n_initialized
= 0;
157 /* Statement change buffer. Data structure used to record state
158 information for statements. This is used to determine what needs
159 to be done in order to update the SSA web after a statement is
160 modified by a pass. If STMT is a statement that has just been
161 created, or needs to be folded via fold_stmt, or anything that
162 changes its physical structure then the pass should:
164 1- Call push_stmt_changes (&stmt) to record the current state of
165 STMT before any modifications are made.
167 2- Make all appropriate modifications to the statement.
169 3- Call pop_stmt_changes (&stmt) to find new symbols that
170 need to be put in SSA form, SSA name mappings for names that
171 have disappeared, recompute invariantness for address
172 expressions, cleanup EH information, etc.
174 If it is possible to determine that the statement was not modified,
175 instead of calling pop_stmt_changes it is quicker to call
176 discard_stmt_changes to avoid the expensive and unnecessary operand
177 re-scan and change comparison. */
181 /* Pointer to the statement being modified. */
184 /* If the statement references memory these are the sets of symbols
185 loaded and stored by the statement. */
190 typedef struct scb_d
*scb_t
;
192 DEF_VEC_ALLOC_P(scb_t
,heap
);
194 /* Stack of statement change buffers (SCB). Every call to
195 push_stmt_changes pushes a new buffer onto the stack. Calls to
196 pop_stmt_changes pop a buffer off of the stack and compute the set
197 of changes for the popped statement. */
198 static VEC(scb_t
,heap
) *scb_stack
;
200 /* Return the DECL_UID of the base variable of T. */
202 static inline unsigned
203 get_name_decl (tree t
)
205 if (TREE_CODE (t
) != SSA_NAME
)
208 return DECL_UID (SSA_NAME_VAR (t
));
212 /* Comparison function for qsort used in operand_build_sort_virtual. */
215 operand_build_cmp (const void *p
, const void *q
)
217 tree e1
= *((const tree
*)p
);
218 tree e2
= *((const tree
*)q
);
221 u1
= get_name_decl (e1
);
222 u2
= get_name_decl (e2
);
224 /* We want to sort in ascending order. They can never be equal. */
225 #ifdef ENABLE_CHECKING
226 gcc_assert (u1
!= u2
);
228 return (u1
> u2
? 1 : -1);
232 /* Sort the virtual operands in LIST from lowest DECL_UID to highest. */
235 operand_build_sort_virtual (VEC(tree
,heap
) *list
)
237 int num
= VEC_length (tree
, list
);
244 if (get_name_decl (VEC_index (tree
, list
, 0))
245 > get_name_decl (VEC_index (tree
, list
, 1)))
247 /* Swap elements if in the wrong order. */
248 tree tmp
= VEC_index (tree
, list
, 0);
249 VEC_replace (tree
, list
, 0, VEC_index (tree
, list
, 1));
250 VEC_replace (tree
, list
, 1, tmp
);
255 /* There are 3 or more elements, call qsort. */
256 qsort (VEC_address (tree
, list
),
257 VEC_length (tree
, list
),
263 /* Return true if the SSA operands cache is active. */
266 ssa_operands_active (void)
268 return cfun
->gimple_df
&& gimple_ssa_operands (cfun
)->ops_active
;
272 /* VOPs are of variable sized, so the free list maps "free buckets" to the
285 Any VOPs larger than this are simply added to the largest bucket when they
289 /* Return the number of operands used in bucket BUCKET. */
292 vop_free_bucket_size (int bucket
)
294 #ifdef ENABLE_CHECKING
295 gcc_assert (bucket
>= 0 && bucket
< NUM_VOP_FREE_BUCKETS
);
299 return (bucket
- 13) * 8;
303 /* For a vop of NUM operands, return the bucket NUM belongs to. If NUM is
304 beyond the end of the bucket table, return -1. */
307 vop_free_bucket_index (int num
)
309 gcc_assert (num
> 0 && NUM_VOP_FREE_BUCKETS
> 16);
311 /* Sizes 1 through 16 use buckets 0-15. */
314 /* Buckets 16 - NUM_VOP_FREE_BUCKETS represent 8 unit chunks. */
315 num
= 14 + (num
- 1) / 8;
316 if (num
>= NUM_VOP_FREE_BUCKETS
)
323 /* Initialize the VOP free buckets. */
326 init_vop_buckets (void)
330 for (x
= 0; x
< NUM_VOP_FREE_BUCKETS
; x
++)
331 gimple_ssa_operands (cfun
)->vop_free_buckets
[x
] = NULL
;
335 /* Add PTR to the appropriate VOP bucket. */
338 add_vop_to_freelist (voptype_p ptr
)
340 int bucket
= vop_free_bucket_index (VUSE_VECT_NUM_ELEM (ptr
->usev
));
342 /* Too large, use the largest bucket so its not a complete throw away. */
344 bucket
= NUM_VOP_FREE_BUCKETS
- 1;
346 ptr
->next
= gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
];
347 gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
] = ptr
;
351 /* These are the sizes of the operand memory buffer which gets allocated each
352 time more operands space is required. The final value is the amount that is
353 allocated every time after that. */
355 #define OP_SIZE_INIT 0
357 #define OP_SIZE_2 110
358 #define OP_SIZE_3 511
360 /* Initialize the operand cache routines. */
363 init_ssa_operands (void)
365 if (!n_initialized
++)
367 build_defs
= VEC_alloc (tree
, heap
, 5);
368 build_uses
= VEC_alloc (tree
, heap
, 10);
369 build_vuses
= VEC_alloc (tree
, heap
, 25);
370 build_vdefs
= VEC_alloc (tree
, heap
, 25);
371 bitmap_obstack_initialize (&operands_bitmap_obstack
);
372 build_loads
= BITMAP_ALLOC (&operands_bitmap_obstack
);
373 build_stores
= BITMAP_ALLOC (&operands_bitmap_obstack
);
374 scb_stack
= VEC_alloc (scb_t
, heap
, 20);
377 gcc_assert (gimple_ssa_operands (cfun
)->operand_memory
== NULL
);
378 gcc_assert (gimple_ssa_operands (cfun
)->mpt_table
== NULL
);
379 gimple_ssa_operands (cfun
)->operand_memory_index
380 = gimple_ssa_operands (cfun
)->ssa_operand_mem_size
;
381 gimple_ssa_operands (cfun
)->ops_active
= true;
382 memset (&clobber_stats
, 0, sizeof (clobber_stats
));
384 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
= OP_SIZE_INIT
;
388 /* Dispose of anything required by the operand routines. */
391 fini_ssa_operands (void)
393 struct ssa_operand_memory_d
*ptr
;
397 if (!--n_initialized
)
399 VEC_free (tree
, heap
, build_defs
);
400 VEC_free (tree
, heap
, build_uses
);
401 VEC_free (tree
, heap
, build_vdefs
);
402 VEC_free (tree
, heap
, build_vuses
);
403 BITMAP_FREE (build_loads
);
404 BITMAP_FREE (build_stores
);
406 /* The change buffer stack had better be empty. */
407 gcc_assert (VEC_length (scb_t
, scb_stack
) == 0);
408 VEC_free (scb_t
, heap
, scb_stack
);
412 gimple_ssa_operands (cfun
)->free_defs
= NULL
;
413 gimple_ssa_operands (cfun
)->free_uses
= NULL
;
415 while ((ptr
= gimple_ssa_operands (cfun
)->operand_memory
) != NULL
)
417 gimple_ssa_operands (cfun
)->operand_memory
418 = gimple_ssa_operands (cfun
)->operand_memory
->next
;
423 VEC_iterate (tree
, gimple_ssa_operands (cfun
)->mpt_table
, ix
, mpt
);
427 BITMAP_FREE (MPT_SYMBOLS (mpt
));
430 VEC_free (tree
, heap
, gimple_ssa_operands (cfun
)->mpt_table
);
432 gimple_ssa_operands (cfun
)->ops_active
= false;
435 bitmap_obstack_release (&operands_bitmap_obstack
);
436 if (dump_file
&& (dump_flags
& TDF_STATS
))
438 fprintf (dump_file
, "Original clobbered vars: %d\n",
439 clobber_stats
.clobbered_vars
);
440 fprintf (dump_file
, "Static write clobbers avoided: %d\n",
441 clobber_stats
.static_write_clobbers_avoided
);
442 fprintf (dump_file
, "Static read clobbers avoided: %d\n",
443 clobber_stats
.static_read_clobbers_avoided
);
444 fprintf (dump_file
, "Unescapable clobbers avoided: %d\n",
445 clobber_stats
.unescapable_clobbers_avoided
);
446 fprintf (dump_file
, "Original read-only clobbers: %d\n",
447 clobber_stats
.readonly_clobbers
);
448 fprintf (dump_file
, "Static read-only clobbers avoided: %d\n",
449 clobber_stats
.static_readonly_clobbers_avoided
);
454 /* Return memory for operands of SIZE chunks. */
457 ssa_operand_alloc (unsigned size
)
461 if (gimple_ssa_operands (cfun
)->operand_memory_index
+ size
462 >= gimple_ssa_operands (cfun
)->ssa_operand_mem_size
)
464 struct ssa_operand_memory_d
*ptr
;
466 if (gimple_ssa_operands (cfun
)->ssa_operand_mem_size
== OP_SIZE_INIT
)
467 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
468 = OP_SIZE_1
* sizeof (struct voptype_d
);
470 if (gimple_ssa_operands (cfun
)->ssa_operand_mem_size
471 == OP_SIZE_1
* sizeof (struct voptype_d
))
472 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
473 = OP_SIZE_2
* sizeof (struct voptype_d
);
475 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
476 = OP_SIZE_3
* sizeof (struct voptype_d
);
478 /* Go right to the maximum size if the request is too large. */
479 if (size
> gimple_ssa_operands (cfun
)->ssa_operand_mem_size
)
480 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
481 = OP_SIZE_3
* sizeof (struct voptype_d
);
483 /* Fail if there is not enough space. If there are this many operands
484 required, first make sure there isn't a different problem causing this
485 many operands. If the decision is that this is OK, then we can
486 specially allocate a buffer just for this request. */
487 gcc_assert (size
<= gimple_ssa_operands (cfun
)->ssa_operand_mem_size
);
489 ptr
= (struct ssa_operand_memory_d
*)
490 ggc_alloc (sizeof (struct ssa_operand_memory_d
)
491 + gimple_ssa_operands (cfun
)->ssa_operand_mem_size
- 1);
492 ptr
->next
= gimple_ssa_operands (cfun
)->operand_memory
;
493 gimple_ssa_operands (cfun
)->operand_memory
= ptr
;
494 gimple_ssa_operands (cfun
)->operand_memory_index
= 0;
496 ptr
= &(gimple_ssa_operands (cfun
)->operand_memory
497 ->mem
[gimple_ssa_operands (cfun
)->operand_memory_index
]);
498 gimple_ssa_operands (cfun
)->operand_memory_index
+= size
;
503 /* Allocate a DEF operand. */
505 static inline struct def_optype_d
*
508 struct def_optype_d
*ret
;
509 if (gimple_ssa_operands (cfun
)->free_defs
)
511 ret
= gimple_ssa_operands (cfun
)->free_defs
;
512 gimple_ssa_operands (cfun
)->free_defs
513 = gimple_ssa_operands (cfun
)->free_defs
->next
;
516 ret
= (struct def_optype_d
*)
517 ssa_operand_alloc (sizeof (struct def_optype_d
));
522 /* Allocate a USE operand. */
524 static inline struct use_optype_d
*
527 struct use_optype_d
*ret
;
528 if (gimple_ssa_operands (cfun
)->free_uses
)
530 ret
= gimple_ssa_operands (cfun
)->free_uses
;
531 gimple_ssa_operands (cfun
)->free_uses
532 = gimple_ssa_operands (cfun
)->free_uses
->next
;
535 ret
= (struct use_optype_d
*)
536 ssa_operand_alloc (sizeof (struct use_optype_d
));
541 /* Allocate a vop with NUM elements. */
543 static inline struct voptype_d
*
546 struct voptype_d
*ret
= NULL
;
549 int bucket
= vop_free_bucket_index (num
);
552 /* If there is a free operand, use it. */
553 if (gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
] != NULL
)
555 ret
= gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
];
556 gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
] =
557 gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
]->next
;
560 alloc_size
= vop_free_bucket_size(bucket
);
566 ret
= (struct voptype_d
*)ssa_operand_alloc (
567 sizeof (struct voptype_d
) + (alloc_size
- 1) * sizeof (vuse_element_t
));
569 VUSE_VECT_NUM_ELEM (ret
->usev
) = num
;
574 /* This routine makes sure that PTR is in an immediate use list, and makes
575 sure the stmt pointer is set to the current stmt. */
578 set_virtual_use_link (use_operand_p ptr
, tree stmt
)
580 /* fold_stmt may have changed the stmt pointers. */
581 if (ptr
->stmt
!= stmt
)
584 /* If this use isn't in a list, add it to the correct list. */
586 link_imm_use (ptr
, *(ptr
->use
));
590 /* Adds OP to the list of defs after LAST. */
592 static inline def_optype_p
593 add_def_op (tree
*op
, def_optype_p last
)
595 def_optype_p new_def
;
597 new_def
= alloc_def ();
598 DEF_OP_PTR (new_def
) = op
;
599 last
->next
= new_def
;
600 new_def
->next
= NULL
;
605 /* Adds OP to the list of uses of statement STMT after LAST. */
607 static inline use_optype_p
608 add_use_op (tree stmt
, tree
*op
, use_optype_p last
)
610 use_optype_p new_use
;
612 new_use
= alloc_use ();
613 USE_OP_PTR (new_use
)->use
= op
;
614 link_imm_use_stmt (USE_OP_PTR (new_use
), *op
, stmt
);
615 last
->next
= new_use
;
616 new_use
->next
= NULL
;
621 /* Return a virtual op pointer with NUM elements which are all initialized to OP
622 and are linked into the immediate uses for STMT. The new vop is appended
625 static inline voptype_p
626 add_vop (tree stmt
, tree op
, int num
, voptype_p prev
)
631 new_vop
= alloc_vop (num
);
632 for (x
= 0; x
< num
; x
++)
634 VUSE_OP_PTR (new_vop
, x
)->prev
= NULL
;
635 SET_VUSE_OP (new_vop
, x
, op
);
636 VUSE_OP_PTR (new_vop
, x
)->use
= &new_vop
->usev
.uses
[x
].use_var
;
637 link_imm_use_stmt (VUSE_OP_PTR (new_vop
, x
),
638 new_vop
->usev
.uses
[x
].use_var
, stmt
);
642 prev
->next
= new_vop
;
643 new_vop
->next
= NULL
;
648 /* Adds OP to the list of vuses of statement STMT after LAST, and moves
649 LAST to the new element. */
651 static inline voptype_p
652 add_vuse_op (tree stmt
, tree op
, int num
, voptype_p last
)
654 voptype_p new_vop
= add_vop (stmt
, op
, num
, last
);
655 VDEF_RESULT (new_vop
) = NULL_TREE
;
660 /* Adds OP to the list of vdefs of statement STMT after LAST, and moves
661 LAST to the new element. */
663 static inline voptype_p
664 add_vdef_op (tree stmt
, tree op
, int num
, voptype_p last
)
666 voptype_p new_vop
= add_vop (stmt
, op
, num
, last
);
667 VDEF_RESULT (new_vop
) = op
;
672 /* Reallocate the virtual operand PTR so that it has NUM_ELEM use slots. ROOT
673 is the head of the operand list it belongs to. */
675 static inline struct voptype_d
*
676 realloc_vop (struct voptype_d
*ptr
, unsigned int num_elem
,
677 struct voptype_d
**root
)
681 struct voptype_d
*ret
, *tmp
;
683 if (VUSE_VECT_NUM_ELEM (ptr
->usev
) == num_elem
)
686 val
= VUSE_OP (ptr
, 0);
687 if (TREE_CODE (val
) == SSA_NAME
)
688 val
= SSA_NAME_VAR (val
);
690 stmt
= USE_STMT (VUSE_OP_PTR (ptr
, 0));
692 /* Delink all the existing uses. */
693 for (x
= 0; x
< VUSE_VECT_NUM_ELEM (ptr
->usev
); x
++)
695 use_operand_p use_p
= VUSE_OP_PTR (ptr
, x
);
696 delink_imm_use (use_p
);
699 /* If we want less space, simply use this one, and shrink the size. */
700 if (VUSE_VECT_NUM_ELEM (ptr
->usev
) > num_elem
)
702 VUSE_VECT_NUM_ELEM (ptr
->usev
) = num_elem
;
706 /* It is growing. Allocate a new one and replace the old one. */
707 ret
= add_vuse_op (stmt
, val
, num_elem
, ptr
);
709 /* Clear PTR and add its memory to the free list. */
710 lim
= VUSE_VECT_NUM_ELEM (ptr
->usev
);
712 sizeof (struct voptype_d
) + sizeof (vuse_element_t
) * (lim
- 1));
713 add_vop_to_freelist (ptr
);
715 /* Now simply remove the old one. */
723 tmp
!= NULL
&& tmp
->next
!= ptr
;
730 /* The pointer passed in isn't in STMT's VDEF lists. */
735 /* Reallocate the PTR vdef so that it has NUM_ELEM use slots. */
738 realloc_vdef (struct voptype_d
*ptr
, unsigned int num_elem
)
741 struct voptype_d
*ret
;
743 val
= VDEF_RESULT (ptr
);
744 stmt
= USE_STMT (VDEF_OP_PTR (ptr
, 0));
745 ret
= realloc_vop (ptr
, num_elem
, &(VDEF_OPS (stmt
)));
746 VDEF_RESULT (ret
) = val
;
751 /* Reallocate the PTR vuse so that it has NUM_ELEM use slots. */
754 realloc_vuse (struct voptype_d
*ptr
, unsigned int num_elem
)
757 struct voptype_d
*ret
;
759 stmt
= USE_STMT (VUSE_OP_PTR (ptr
, 0));
760 ret
= realloc_vop (ptr
, num_elem
, &(VUSE_OPS (stmt
)));
765 /* Takes elements from build_defs and turns them into def operands of STMT.
766 TODO -- Make build_defs VEC of tree *. */
769 finalize_ssa_defs (tree stmt
)
772 struct def_optype_d new_list
;
773 def_optype_p old_ops
, last
;
774 unsigned int num
= VEC_length (tree
, build_defs
);
776 /* There should only be a single real definition per assignment. */
777 gcc_assert ((stmt
&& TREE_CODE (stmt
) != GIMPLE_MODIFY_STMT
) || num
<= 1);
779 new_list
.next
= NULL
;
782 old_ops
= DEF_OPS (stmt
);
786 /* Check for the common case of 1 def that hasn't changed. */
787 if (old_ops
&& old_ops
->next
== NULL
&& num
== 1
788 && (tree
*) VEC_index (tree
, build_defs
, 0) == DEF_OP_PTR (old_ops
))
791 /* If there is anything in the old list, free it. */
794 old_ops
->next
= gimple_ssa_operands (cfun
)->free_defs
;
795 gimple_ssa_operands (cfun
)->free_defs
= old_ops
;
798 /* If there is anything remaining in the build_defs list, simply emit it. */
799 for ( ; new_i
< num
; new_i
++)
800 last
= add_def_op ((tree
*) VEC_index (tree
, build_defs
, new_i
), last
);
802 /* Now set the stmt's operands. */
803 DEF_OPS (stmt
) = new_list
.next
;
805 #ifdef ENABLE_CHECKING
809 for (ptr
= DEF_OPS (stmt
); ptr
; ptr
= ptr
->next
)
812 gcc_assert (x
== num
);
818 /* Takes elements from build_uses and turns them into use operands of STMT.
819 TODO -- Make build_uses VEC of tree *. */
822 finalize_ssa_uses (tree stmt
)
825 struct use_optype_d new_list
;
826 use_optype_p old_ops
, ptr
, last
;
828 #ifdef ENABLE_CHECKING
831 unsigned num
= VEC_length (tree
, build_uses
);
833 /* If the pointer to the operand is the statement itself, something is
834 wrong. It means that we are pointing to a local variable (the
835 initial call to update_stmt_operands does not pass a pointer to a
837 for (x
= 0; x
< num
; x
++)
838 gcc_assert (*((tree
*)VEC_index (tree
, build_uses
, x
)) != stmt
);
842 new_list
.next
= NULL
;
845 old_ops
= USE_OPS (stmt
);
847 /* If there is anything in the old list, free it. */
850 for (ptr
= old_ops
; ptr
; ptr
= ptr
->next
)
851 delink_imm_use (USE_OP_PTR (ptr
));
852 old_ops
->next
= gimple_ssa_operands (cfun
)->free_uses
;
853 gimple_ssa_operands (cfun
)->free_uses
= old_ops
;
856 /* Now create nodes for all the new nodes. */
857 for (new_i
= 0; new_i
< VEC_length (tree
, build_uses
); new_i
++)
858 last
= add_use_op (stmt
,
859 (tree
*) VEC_index (tree
, build_uses
, new_i
),
862 /* Now set the stmt's operands. */
863 USE_OPS (stmt
) = new_list
.next
;
865 #ifdef ENABLE_CHECKING
868 for (ptr
= USE_OPS (stmt
); ptr
; ptr
= ptr
->next
)
871 gcc_assert (x
== VEC_length (tree
, build_uses
));
877 /* Takes elements from BUILD_VDEFS and turns them into vdef operands of
878 STMT. FIXME, for now VDEF operators should have a single operand
882 finalize_ssa_vdefs (tree stmt
)
885 struct voptype_d new_list
;
886 voptype_p old_ops
, ptr
, last
;
887 stmt_ann_t ann
= stmt_ann (stmt
);
889 /* Set the symbols referenced by STMT. */
890 if (!bitmap_empty_p (build_stores
))
892 if (ann
->operands
.stores
== NULL
)
893 ann
->operands
.stores
= BITMAP_ALLOC (&operands_bitmap_obstack
);
895 bitmap_copy (ann
->operands
.stores
, build_stores
);
898 BITMAP_FREE (ann
->operands
.stores
);
900 /* If aliases have not been computed, do not instantiate a virtual
901 operator on STMT. Initially, we only compute the SSA form on
902 GIMPLE registers. The virtual SSA form is only computed after
903 alias analysis, so virtual operators will remain unrenamed and
904 the verifier will complain. However, alias analysis needs to
905 access symbol load/store information, so we need to compute
907 if (!gimple_aliases_computed_p (cfun
))
910 new_list
.next
= NULL
;
913 old_ops
= VDEF_OPS (stmt
);
915 while (old_ops
&& new_i
< VEC_length (tree
, build_vdefs
))
917 tree op
= VEC_index (tree
, build_vdefs
, new_i
);
918 unsigned new_uid
= get_name_decl (op
);
919 unsigned old_uid
= get_name_decl (VDEF_RESULT (old_ops
));
921 /* FIXME, for now each VDEF operator should have at most one
922 operand in their RHS. */
923 gcc_assert (VDEF_NUM (old_ops
) == 1);
925 if (old_uid
== new_uid
)
927 /* If the symbols are the same, reuse the existing operand. */
928 last
->next
= old_ops
;
930 old_ops
= old_ops
->next
;
932 set_virtual_use_link (VDEF_OP_PTR (last
, 0), stmt
);
935 else if (old_uid
< new_uid
)
937 /* If old is less than new, old goes to the free list. */
939 delink_imm_use (VDEF_OP_PTR (old_ops
, 0));
940 next
= old_ops
->next
;
941 add_vop_to_freelist (old_ops
);
946 /* This is a new operand. */
947 last
= add_vdef_op (stmt
, op
, 1, last
);
952 /* If there is anything remaining in BUILD_VDEFS, simply emit it. */
953 for ( ; new_i
< VEC_length (tree
, build_vdefs
); new_i
++)
954 last
= add_vdef_op (stmt
, VEC_index (tree
, build_vdefs
, new_i
), 1, last
);
956 /* If there is anything in the old list, free it. */
959 for (ptr
= old_ops
; ptr
; ptr
= last
)
962 delink_imm_use (VDEF_OP_PTR (ptr
, 0));
963 add_vop_to_freelist (ptr
);
967 /* Now set STMT's operands. */
968 VDEF_OPS (stmt
) = new_list
.next
;
970 #ifdef ENABLE_CHECKING
973 for (ptr
= VDEF_OPS (stmt
); ptr
; ptr
= ptr
->next
)
976 gcc_assert (x
== VEC_length (tree
, build_vdefs
));
982 /* Takes elements from BUILD_VUSES and turns them into VUSE operands of
986 finalize_ssa_vuse_ops (tree stmt
)
988 unsigned new_i
, old_i
;
989 voptype_p old_ops
, last
;
990 VEC(tree
,heap
) *new_ops
;
993 /* Set the symbols referenced by STMT. */
994 ann
= stmt_ann (stmt
);
995 if (!bitmap_empty_p (build_loads
))
997 if (ann
->operands
.loads
== NULL
)
998 ann
->operands
.loads
= BITMAP_ALLOC (&operands_bitmap_obstack
);
1000 bitmap_copy (ann
->operands
.loads
, build_loads
);
1003 BITMAP_FREE (ann
->operands
.loads
);
1005 /* If aliases have not been computed, do not instantiate a virtual
1006 operator on STMT. Initially, we only compute the SSA form on
1007 GIMPLE registers. The virtual SSA form is only computed after
1008 alias analysis, so virtual operators will remain unrenamed and
1009 the verifier will complain. However, alias analysis needs to
1010 access symbol load/store information, so we need to compute
1012 if (!gimple_aliases_computed_p (cfun
))
1015 /* STMT should have at most one VUSE operator. */
1016 old_ops
= VUSE_OPS (stmt
);
1017 gcc_assert (old_ops
== NULL
|| old_ops
->next
== NULL
);
1022 && old_i
< VUSE_NUM (old_ops
)
1023 && new_i
< VEC_length (tree
, build_vuses
))
1025 tree new_op
= VEC_index (tree
, build_vuses
, new_i
);
1026 tree old_op
= VUSE_OP (old_ops
, old_i
);
1027 unsigned new_uid
= get_name_decl (new_op
);
1028 unsigned old_uid
= get_name_decl (old_op
);
1030 if (old_uid
== new_uid
)
1032 /* If the symbols are the same, reuse the existing operand. */
1033 VEC_safe_push (tree
, heap
, new_ops
, old_op
);
1037 else if (old_uid
< new_uid
)
1039 /* If OLD_UID is less than NEW_UID, the old operand has
1040 disappeared, skip to the next old operand. */
1045 /* This is a new operand. */
1046 VEC_safe_push (tree
, heap
, new_ops
, new_op
);
1051 /* If there is anything remaining in the build_vuses list, simply emit it. */
1052 for ( ; new_i
< VEC_length (tree
, build_vuses
); new_i
++)
1053 VEC_safe_push (tree
, heap
, new_ops
, VEC_index (tree
, build_vuses
, new_i
));
1055 /* If there is anything in the old list, free it. */
1058 for (old_i
= 0; old_i
< VUSE_NUM (old_ops
); old_i
++)
1059 delink_imm_use (VUSE_OP_PTR (old_ops
, old_i
));
1060 add_vop_to_freelist (old_ops
);
1061 VUSE_OPS (stmt
) = NULL
;
1064 /* If there are any operands, instantiate a VUSE operator for STMT. */
1070 last
= add_vuse_op (stmt
, NULL
, VEC_length (tree
, new_ops
), NULL
);
1072 for (i
= 0; VEC_iterate (tree
, new_ops
, i
, op
); i
++)
1073 SET_USE (VUSE_OP_PTR (last
, (int) i
), op
);
1075 VUSE_OPS (stmt
) = last
;
1076 VEC_free (tree
, heap
, new_ops
);
1079 #ifdef ENABLE_CHECKING
1083 if (VUSE_OPS (stmt
))
1085 gcc_assert (VUSE_OPS (stmt
)->next
== NULL
);
1086 x
= VUSE_NUM (VUSE_OPS (stmt
));
1091 gcc_assert (x
== VEC_length (tree
, build_vuses
));
1096 /* Return a new VUSE operand vector for STMT. */
1099 finalize_ssa_vuses (tree stmt
)
1101 unsigned num
, num_vdefs
;
1102 unsigned vuse_index
;
1104 /* Remove superfluous VUSE operands. If the statement already has a
1105 VDEF operator for a variable 'a', then a VUSE for 'a' is not
1106 needed because VDEFs imply a VUSE of the variable. For instance,
1107 suppose that variable 'a' is pointed-to by p and q:
1113 The VUSE <a_2> is superfluous because it is implied by the
1115 num
= VEC_length (tree
, build_vuses
);
1116 num_vdefs
= VEC_length (tree
, build_vdefs
);
1118 if (num
> 0 && num_vdefs
> 0)
1119 for (vuse_index
= 0; vuse_index
< VEC_length (tree
, build_vuses
); )
1122 vuse
= VEC_index (tree
, build_vuses
, vuse_index
);
1123 if (TREE_CODE (vuse
) != SSA_NAME
)
1125 var_ann_t ann
= var_ann (vuse
);
1126 ann
->in_vuse_list
= 0;
1127 if (ann
->in_vdef_list
)
1129 VEC_ordered_remove (tree
, build_vuses
, vuse_index
);
1136 finalize_ssa_vuse_ops (stmt
);
1140 /* Clear the in_list bits and empty the build array for VDEFs and
1144 cleanup_build_arrays (void)
1149 for (i
= 0; VEC_iterate (tree
, build_vdefs
, i
, t
); i
++)
1150 if (TREE_CODE (t
) != SSA_NAME
)
1151 var_ann (t
)->in_vdef_list
= false;
1153 for (i
= 0; VEC_iterate (tree
, build_vuses
, i
, t
); i
++)
1154 if (TREE_CODE (t
) != SSA_NAME
)
1155 var_ann (t
)->in_vuse_list
= false;
1157 VEC_truncate (tree
, build_vdefs
, 0);
1158 VEC_truncate (tree
, build_vuses
, 0);
1159 VEC_truncate (tree
, build_defs
, 0);
1160 VEC_truncate (tree
, build_uses
, 0);
1161 bitmap_clear (build_loads
);
1162 bitmap_clear (build_stores
);
1166 /* Finalize all the build vectors, fill the new ones into INFO. */
1169 finalize_ssa_stmt_operands (tree stmt
)
1171 finalize_ssa_defs (stmt
);
1172 finalize_ssa_uses (stmt
);
1173 finalize_ssa_vdefs (stmt
);
1174 finalize_ssa_vuses (stmt
);
1175 cleanup_build_arrays ();
1179 /* Start the process of building up operands vectors in INFO. */
1182 start_ssa_stmt_operands (void)
1184 gcc_assert (VEC_length (tree
, build_defs
) == 0);
1185 gcc_assert (VEC_length (tree
, build_uses
) == 0);
1186 gcc_assert (VEC_length (tree
, build_vuses
) == 0);
1187 gcc_assert (VEC_length (tree
, build_vdefs
) == 0);
1188 gcc_assert (bitmap_empty_p (build_loads
));
1189 gcc_assert (bitmap_empty_p (build_stores
));
1193 /* Add DEF_P to the list of pointers to operands. */
1196 append_def (tree
*def_p
)
1198 VEC_safe_push (tree
, heap
, build_defs
, (tree
) def_p
);
1202 /* Add USE_P to the list of pointers to operands. */
1205 append_use (tree
*use_p
)
1207 VEC_safe_push (tree
, heap
, build_uses
, (tree
) use_p
);
1211 /* Add VAR to the set of variables that require a VDEF operator. */
1214 append_vdef (tree var
)
1218 if (TREE_CODE (var
) != SSA_NAME
)
1223 /* If VAR belongs to a memory partition, use it instead of VAR. */
1224 mpt
= memory_partition (var
);
1228 /* Don't allow duplicate entries. */
1229 ann
= get_var_ann (var
);
1230 if (ann
->in_vdef_list
)
1233 ann
->in_vdef_list
= true;
1237 sym
= SSA_NAME_VAR (var
);
1239 VEC_safe_push (tree
, heap
, build_vdefs
, var
);
1240 bitmap_set_bit (build_stores
, DECL_UID (sym
));
1244 /* Add VAR to the set of variables that require a VUSE operator. */
1247 append_vuse (tree var
)
1251 if (TREE_CODE (var
) != SSA_NAME
)
1256 /* If VAR belongs to a memory partition, use it instead of VAR. */
1257 mpt
= memory_partition (var
);
1261 /* Don't allow duplicate entries. */
1262 ann
= get_var_ann (var
);
1263 if (ann
->in_vuse_list
|| ann
->in_vdef_list
)
1266 ann
->in_vuse_list
= true;
1270 sym
= SSA_NAME_VAR (var
);
1272 VEC_safe_push (tree
, heap
, build_vuses
, var
);
1273 bitmap_set_bit (build_loads
, DECL_UID (sym
));
1277 /* REF is a tree that contains the entire pointer dereference
1278 expression, if available, or NULL otherwise. ALIAS is the variable
1279 we are asking if REF can access. OFFSET and SIZE come from the
1280 memory access expression that generated this virtual operand. */
1283 access_can_touch_variable (tree ref
, tree alias
, HOST_WIDE_INT offset
,
1286 bool offsetgtz
= offset
> 0;
1287 unsigned HOST_WIDE_INT uoffset
= (unsigned HOST_WIDE_INT
) offset
;
1288 tree base
= ref
? get_base_address (ref
) : NULL
;
1290 /* If ALIAS is .GLOBAL_VAR then the memory reference REF must be
1291 using a call-clobbered memory tag. By definition, call-clobbered
1292 memory tags can always touch .GLOBAL_VAR. */
1293 if (alias
== gimple_global_var (cfun
))
1296 /* If ALIAS is an SFT, it can't be touched if the offset
1297 and size of the access is not overlapping with the SFT offset and
1298 size. This is only true if we are accessing through a pointer
1299 to a type that is the same as SFT_PARENT_VAR. Otherwise, we may
1300 be accessing through a pointer to some substruct of the
1301 structure, and if we try to prune there, we will have the wrong
1302 offset, and get the wrong answer.
1303 i.e., we can't prune without more work if we have something like
1309 const char *byte_op;
1317 foo = &targetm.asm_out.aligned_op;
1320 SFT.1, which represents hi, will have SFT_OFFSET=32 because in
1321 terms of SFT_PARENT_VAR, that is where it is.
1322 However, the access through the foo pointer will be at offset 0. */
1324 && TREE_CODE (alias
) == STRUCT_FIELD_TAG
1326 && TREE_TYPE (base
) == TREE_TYPE (SFT_PARENT_VAR (alias
))
1327 && !overlap_subvar (offset
, size
, alias
, NULL
))
1329 #ifdef ACCESS_DEBUGGING
1330 fprintf (stderr
, "Access to ");
1331 print_generic_expr (stderr
, ref
, 0);
1332 fprintf (stderr
, " may not touch ");
1333 print_generic_expr (stderr
, alias
, 0);
1334 fprintf (stderr
, " in function %s\n", get_name (current_function_decl
));
1339 /* Without strict aliasing, it is impossible for a component access
1340 through a pointer to touch a random variable, unless that
1341 variable *is* a structure or a pointer.
1343 That is, given p->c, and some random global variable b,
1344 there is no legal way that p->c could be an access to b.
1346 Without strict aliasing on, we consider it legal to do something
1349 struct foos { int l; };
1351 static struct foos *getfoo(void);
1354 struct foos *f = getfoo();
1361 static struct foos *getfoo(void)
1362 { return (struct foos *)&foo; }
1364 (taken from 20000623-1.c)
1366 The docs also say/imply that access through union pointers
1367 is legal (but *not* if you take the address of the union member,
1368 i.e. the inverse), such that you can do
1378 U *pretmp = (U*)&rv;
1382 To implement this, we just punt on accesses through union
1386 && flag_strict_aliasing
1387 && TREE_CODE (ref
) != INDIRECT_REF
1389 && (TREE_CODE (base
) != INDIRECT_REF
1390 || TREE_CODE (TREE_TYPE (base
)) != UNION_TYPE
)
1391 && !AGGREGATE_TYPE_P (TREE_TYPE (alias
))
1392 && TREE_CODE (TREE_TYPE (alias
)) != COMPLEX_TYPE
1393 && !var_ann (alias
)->is_heapvar
1394 /* When the struct has may_alias attached to it, we need not to
1396 && get_alias_set (base
))
1398 #ifdef ACCESS_DEBUGGING
1399 fprintf (stderr
, "Access to ");
1400 print_generic_expr (stderr
, ref
, 0);
1401 fprintf (stderr
, " may not touch ");
1402 print_generic_expr (stderr
, alias
, 0);
1403 fprintf (stderr
, " in function %s\n", get_name (current_function_decl
));
1408 /* If the offset of the access is greater than the size of one of
1409 the possible aliases, it can't be touching that alias, because it
1410 would be past the end of the structure. */
1412 && flag_strict_aliasing
1413 && TREE_CODE (ref
) != INDIRECT_REF
1415 && !POINTER_TYPE_P (TREE_TYPE (alias
))
1417 && DECL_SIZE (alias
)
1418 && TREE_CODE (DECL_SIZE (alias
)) == INTEGER_CST
1419 && uoffset
> TREE_INT_CST_LOW (DECL_SIZE (alias
)))
1421 #ifdef ACCESS_DEBUGGING
1422 fprintf (stderr
, "Access to ");
1423 print_generic_expr (stderr
, ref
, 0);
1424 fprintf (stderr
, " may not touch ");
1425 print_generic_expr (stderr
, alias
, 0);
1426 fprintf (stderr
, " in function %s\n", get_name (current_function_decl
));
1435 /* Add VAR to the virtual operands array. FLAGS is as in
1436 get_expr_operands. FULL_REF is a tree that contains the entire
1437 pointer dereference expression, if available, or NULL otherwise.
1438 OFFSET and SIZE come from the memory access expression that
1439 generated this virtual operand. IS_CALL_SITE is true if the
1440 affected statement is a call site. */
1443 add_virtual_operand (tree var
, stmt_ann_t s_ann
, int flags
,
1444 tree full_ref
, HOST_WIDE_INT offset
,
1445 HOST_WIDE_INT size
, bool is_call_site
)
1447 bitmap aliases
= NULL
;
1451 sym
= (TREE_CODE (var
) == SSA_NAME
? SSA_NAME_VAR (var
) : var
);
1452 v_ann
= var_ann (sym
);
1454 /* Mark the statement as having memory operands. */
1455 s_ann
->references_memory
= true;
1457 /* Mark statements with volatile operands. Optimizers should back
1458 off from statements having volatile operands. */
1459 if (TREE_THIS_VOLATILE (sym
) && s_ann
)
1460 s_ann
->has_volatile_ops
= true;
1462 /* If the variable cannot be modified and this is a VDEF change
1463 it into a VUSE. This happens when read-only variables are marked
1464 call-clobbered and/or aliased to writable variables. So we only
1465 check that this only happens on non-specific stores.
1467 Note that if this is a specific store, i.e. associated with a
1468 GIMPLE_MODIFY_STMT, then we can't suppress the VDEF, lest we run
1469 into validation problems.
1471 This can happen when programs cast away const, leaving us with a
1472 store to read-only memory. If the statement is actually executed
1473 at runtime, then the program is ill formed. If the statement is
1474 not executed then all is well. At the very least, we cannot ICE. */
1475 if ((flags
& opf_implicit
) && unmodifiable_var_p (var
))
1478 /* The variable is not a GIMPLE register. Add it (or its aliases) to
1479 virtual operands, unless the caller has specifically requested
1480 not to add virtual operands (used when adding operands inside an
1481 ADDR_EXPR expression). */
1482 if (flags
& opf_no_vops
)
1486 aliases
= MTAG_ALIASES (var
);
1488 if (aliases
== NULL
)
1490 if (s_ann
&& !gimple_aliases_computed_p (cfun
))
1491 s_ann
->has_volatile_ops
= true;
1493 /* The variable is not aliased or it is an alias tag. */
1494 if (flags
& opf_def
)
1505 /* The variable is aliased. Add its aliases to the virtual
1507 gcc_assert (!bitmap_empty_p (aliases
));
1509 if (flags
& opf_def
)
1511 bool none_added
= true;
1512 EXECUTE_IF_SET_IN_BITMAP (aliases
, 0, i
, bi
)
1514 al
= referenced_var (i
);
1515 if (!access_can_touch_variable (full_ref
, al
, offset
, size
))
1518 /* Call-clobbered tags may have non-call-clobbered
1519 symbols in their alias sets. Ignore them if we are
1520 adding VOPs for a call site. */
1521 if (is_call_site
&& !is_call_clobbered (al
))
1528 /* If the variable is also an alias tag, add a virtual
1529 operand for it, otherwise we will miss representing
1530 references to the members of the variable's alias set.
1531 This fixes the bug in gcc.c-torture/execute/20020503-1.c.
1533 It is also necessary to add bare defs on clobbers for
1534 SMT's, so that bare SMT uses caused by pruning all the
1535 aliases will link up properly with calls. In order to
1536 keep the number of these bare defs we add down to the
1537 minimum necessary, we keep track of which SMT's were used
1538 alone in statement vdefs or VUSEs. */
1540 || (TREE_CODE (var
) == SYMBOL_MEMORY_TAG
1548 bool none_added
= true;
1549 EXECUTE_IF_SET_IN_BITMAP (aliases
, 0, i
, bi
)
1551 al
= referenced_var (i
);
1552 if (!access_can_touch_variable (full_ref
, al
, offset
, size
))
1555 /* Call-clobbered tags may have non-call-clobbered
1556 symbols in their alias sets. Ignore them if we are
1557 adding VOPs for a call site. */
1558 if (is_call_site
&& !is_call_clobbered (al
))
1565 /* Even if no aliases have been added, we still need to
1566 establish def-use and use-def chains, lest
1567 transformations think that this is not a memory
1568 reference. For an example of this scenario, see
1569 testsuite/g++.dg/opt/cleanup1.C. */
1577 /* Add *VAR_P to the appropriate operand array for S_ANN. FLAGS is as in
1578 get_expr_operands. If *VAR_P is a GIMPLE register, it will be added to
1579 the statement's real operands, otherwise it is added to virtual
1583 add_stmt_operand (tree
*var_p
, stmt_ann_t s_ann
, int flags
)
1588 gcc_assert (SSA_VAR_P (*var_p
) && s_ann
);
1591 sym
= (TREE_CODE (var
) == SSA_NAME
? SSA_NAME_VAR (var
) : var
);
1592 v_ann
= var_ann (sym
);
1594 /* Mark statements with volatile operands. */
1595 if (TREE_THIS_VOLATILE (sym
))
1596 s_ann
->has_volatile_ops
= true;
1598 if (is_gimple_reg (sym
))
1600 /* The variable is a GIMPLE register. Add it to real operands. */
1601 if (flags
& opf_def
)
1607 add_virtual_operand (var
, s_ann
, flags
, NULL_TREE
, 0, -1, false);
1611 /* A subroutine of get_expr_operands to handle INDIRECT_REF,
1612 ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF.
1614 STMT is the statement being processed, EXPR is the INDIRECT_REF
1617 FLAGS is as in get_expr_operands.
1619 FULL_REF contains the full pointer dereference expression, if we
1620 have it, or NULL otherwise.
1622 OFFSET and SIZE are the location of the access inside the
1623 dereferenced pointer, if known.
1625 RECURSE_ON_BASE should be set to true if we want to continue
1626 calling get_expr_operands on the base pointer, and false if
1627 something else will do it for us. */
1630 get_indirect_ref_operands (tree stmt
, tree expr
, int flags
,
1632 HOST_WIDE_INT offset
, HOST_WIDE_INT size
,
1633 bool recurse_on_base
)
1635 tree
*pptr
= &TREE_OPERAND (expr
, 0);
1637 stmt_ann_t s_ann
= stmt_ann (stmt
);
1639 s_ann
->references_memory
= true;
1640 if (s_ann
&& TREE_THIS_VOLATILE (expr
))
1641 s_ann
->has_volatile_ops
= true;
1643 if (SSA_VAR_P (ptr
))
1645 struct ptr_info_def
*pi
= NULL
;
1647 /* If PTR has flow-sensitive points-to information, use it. */
1648 if (TREE_CODE (ptr
) == SSA_NAME
1649 && (pi
= SSA_NAME_PTR_INFO (ptr
)) != NULL
1650 && pi
->name_mem_tag
)
1652 /* PTR has its own memory tag. Use it. */
1653 add_virtual_operand (pi
->name_mem_tag
, s_ann
, flags
,
1654 full_ref
, offset
, size
, false);
1658 /* If PTR is not an SSA_NAME or it doesn't have a name
1659 tag, use its symbol memory tag. */
1662 /* If we are emitting debugging dumps, display a warning if
1663 PTR is an SSA_NAME with no flow-sensitive alias
1664 information. That means that we may need to compute
1667 && TREE_CODE (ptr
) == SSA_NAME
1671 "NOTE: no flow-sensitive alias info for ");
1672 print_generic_expr (dump_file
, ptr
, dump_flags
);
1673 fprintf (dump_file
, " in ");
1674 print_generic_stmt (dump_file
, stmt
, dump_flags
);
1677 if (TREE_CODE (ptr
) == SSA_NAME
)
1678 ptr
= SSA_NAME_VAR (ptr
);
1679 v_ann
= var_ann (ptr
);
1681 if (v_ann
->symbol_mem_tag
)
1682 add_virtual_operand (v_ann
->symbol_mem_tag
, s_ann
, flags
,
1683 full_ref
, offset
, size
, false);
1685 /* Aliasing information is missing; mark statement as
1686 volatile so we won't optimize it out too actively. */
1688 && !gimple_aliases_computed_p (cfun
)
1689 && (flags
& opf_def
))
1690 s_ann
->has_volatile_ops
= true;
1693 else if (TREE_CODE (ptr
) == INTEGER_CST
)
1695 /* If a constant is used as a pointer, we can't generate a real
1696 operand for it but we mark the statement volatile to prevent
1697 optimizations from messing things up. */
1699 s_ann
->has_volatile_ops
= true;
1704 /* Ok, this isn't even is_gimple_min_invariant. Something's broke. */
1708 /* If requested, add a USE operand for the base pointer. */
1709 if (recurse_on_base
)
1710 get_expr_operands (stmt
, pptr
, opf_use
);
1714 /* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */
1717 get_tmr_operands (tree stmt
, tree expr
, int flags
)
1720 HOST_WIDE_INT offset
, size
, maxsize
;
1722 stmt_ann_t s_ann
= stmt_ann (stmt
);
1724 /* This statement references memory. */
1725 s_ann
->references_memory
= 1;
1727 /* First record the real operands. */
1728 get_expr_operands (stmt
, &TMR_BASE (expr
), opf_use
);
1729 get_expr_operands (stmt
, &TMR_INDEX (expr
), opf_use
);
1731 if (TMR_SYMBOL (expr
))
1732 add_to_addressable_set (TMR_SYMBOL (expr
), &s_ann
->addresses_taken
);
1734 tag
= TMR_TAG (expr
);
1737 /* Something weird, so ensure that we will be careful. */
1738 s_ann
->has_volatile_ops
= true;
1744 get_expr_operands (stmt
, &tag
, flags
);
1748 ref
= get_ref_base_and_extent (tag
, &offset
, &size
, &maxsize
);
1749 gcc_assert (ref
!= NULL_TREE
);
1750 svars
= get_subvars_for_var (ref
);
1751 for (sv
= svars
; sv
; sv
= sv
->next
)
1755 if (overlap_subvar (offset
, maxsize
, sv
->var
, &exact
))
1756 add_stmt_operand (&sv
->var
, s_ann
, flags
);
1761 /* Add clobbering definitions for .GLOBAL_VAR or for each of the call
1762 clobbered variables in the function. */
1765 add_call_clobber_ops (tree stmt
, tree callee
)
1769 stmt_ann_t s_ann
= stmt_ann (stmt
);
1770 bitmap not_read_b
, not_written_b
;
1772 /* Functions that are not const, pure or never return may clobber
1773 call-clobbered variables. */
1775 s_ann
->makes_clobbering_call
= true;
1777 /* If we created .GLOBAL_VAR earlier, just use it. */
1778 if (gimple_global_var (cfun
))
1780 tree var
= gimple_global_var (cfun
);
1781 add_virtual_operand (var
, s_ann
, opf_def
, NULL
, 0, -1, true);
1785 /* Get info for local and module level statics. There is a bit
1786 set for each static if the call being processed does not read
1787 or write that variable. */
1788 not_read_b
= callee
? ipa_reference_get_not_read_global (callee
) : NULL
;
1789 not_written_b
= callee
? ipa_reference_get_not_written_global (callee
) : NULL
;
1791 /* Add a VDEF operand for every call clobbered variable. */
1792 EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun
), 0, u
, bi
)
1794 tree var
= referenced_var_lookup (u
);
1795 unsigned int escape_mask
= var_ann (var
)->escape_mask
;
1796 tree real_var
= var
;
1800 /* Not read and not written are computed on regular vars, not
1801 subvars, so look at the parent var if this is an SFT. */
1802 if (TREE_CODE (var
) == STRUCT_FIELD_TAG
)
1803 real_var
= SFT_PARENT_VAR (var
);
1805 not_read
= not_read_b
1806 ? bitmap_bit_p (not_read_b
, DECL_UID (real_var
))
1809 not_written
= not_written_b
1810 ? bitmap_bit_p (not_written_b
, DECL_UID (real_var
))
1812 gcc_assert (!unmodifiable_var_p (var
));
1814 clobber_stats
.clobbered_vars
++;
1816 /* See if this variable is really clobbered by this function. */
1818 /* Trivial case: Things escaping only to pure/const are not
1819 clobbered by non-pure-const, and only read by pure/const. */
1820 if ((escape_mask
& ~(ESCAPE_TO_PURE_CONST
)) == 0)
1822 tree call
= get_call_expr_in (stmt
);
1823 if (call_expr_flags (call
) & (ECF_CONST
| ECF_PURE
))
1825 add_virtual_operand (var
, s_ann
, opf_use
, NULL
, 0, -1, true);
1826 clobber_stats
.unescapable_clobbers_avoided
++;
1831 clobber_stats
.unescapable_clobbers_avoided
++;
1838 clobber_stats
.static_write_clobbers_avoided
++;
1840 add_virtual_operand (var
, s_ann
, opf_use
, NULL
, 0, -1, true);
1842 clobber_stats
.static_read_clobbers_avoided
++;
1845 add_virtual_operand (var
, s_ann
, opf_def
, NULL
, 0, -1, true);
1850 /* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the
1854 add_call_read_ops (tree stmt
, tree callee
)
1858 stmt_ann_t s_ann
= stmt_ann (stmt
);
1861 /* if the function is not pure, it may reference memory. Add
1862 a VUSE for .GLOBAL_VAR if it has been created. See add_referenced_var
1863 for the heuristic used to decide whether to create .GLOBAL_VAR. */
1864 if (gimple_global_var (cfun
))
1866 tree var
= gimple_global_var (cfun
);
1867 add_virtual_operand (var
, s_ann
, opf_use
, NULL
, 0, -1, true);
1871 not_read_b
= callee
? ipa_reference_get_not_read_global (callee
) : NULL
;
1873 /* Add a VUSE for each call-clobbered variable. */
1874 EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun
), 0, u
, bi
)
1876 tree var
= referenced_var (u
);
1877 tree real_var
= var
;
1880 clobber_stats
.readonly_clobbers
++;
1882 /* Not read and not written are computed on regular vars, not
1883 subvars, so look at the parent var if this is an SFT. */
1885 if (TREE_CODE (var
) == STRUCT_FIELD_TAG
)
1886 real_var
= SFT_PARENT_VAR (var
);
1888 not_read
= not_read_b
? bitmap_bit_p (not_read_b
, DECL_UID (real_var
))
1893 clobber_stats
.static_readonly_clobbers_avoided
++;
1897 add_virtual_operand (var
, s_ann
, opf_use
, NULL
, 0, -1, true);
1902 /* A subroutine of get_expr_operands to handle CALL_EXPR. */
1905 get_call_expr_operands (tree stmt
, tree expr
)
1907 int call_flags
= call_expr_flags (expr
);
1909 stmt_ann_t ann
= stmt_ann (stmt
);
1911 ann
->references_memory
= true;
1913 /* If aliases have been computed already, add VDEF or VUSE
1914 operands for all the symbols that have been found to be
1916 if (gimple_aliases_computed_p (cfun
)
1917 && !(call_flags
& ECF_NOVOPS
))
1919 /* A 'pure' or a 'const' function never call-clobbers anything.
1920 A 'noreturn' function might, but since we don't return anyway
1921 there is no point in recording that. */
1922 if (TREE_SIDE_EFFECTS (expr
)
1923 && !(call_flags
& (ECF_PURE
| ECF_CONST
| ECF_NORETURN
)))
1924 add_call_clobber_ops (stmt
, get_callee_fndecl (expr
));
1925 else if (!(call_flags
& ECF_CONST
))
1926 add_call_read_ops (stmt
, get_callee_fndecl (expr
));
1929 /* Find uses in the called function. */
1930 get_expr_operands (stmt
, &CALL_EXPR_FN (expr
), opf_use
);
1931 nargs
= call_expr_nargs (expr
);
1932 for (i
= 0; i
< nargs
; i
++)
1933 get_expr_operands (stmt
, &CALL_EXPR_ARG (expr
, i
), opf_use
);
1935 get_expr_operands (stmt
, &CALL_EXPR_STATIC_CHAIN (expr
), opf_use
);
1939 /* Scan operands in the ASM_EXPR stmt referred to in INFO. */
1942 get_asm_expr_operands (tree stmt
)
1946 const char **oconstraints
;
1947 const char *constraint
;
1948 bool allows_mem
, allows_reg
, is_inout
;
1951 s_ann
= stmt_ann (stmt
);
1952 noutputs
= list_length (ASM_OUTPUTS (stmt
));
1953 oconstraints
= (const char **) alloca ((noutputs
) * sizeof (const char *));
1955 /* Gather all output operands. */
1956 for (i
= 0, link
= ASM_OUTPUTS (stmt
); link
; i
++, link
= TREE_CHAIN (link
))
1958 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
1959 oconstraints
[i
] = constraint
;
1960 parse_output_constraint (&constraint
, i
, 0, 0, &allows_mem
,
1961 &allows_reg
, &is_inout
);
1963 /* This should have been split in gimplify_asm_expr. */
1964 gcc_assert (!allows_reg
|| !is_inout
);
1966 /* Memory operands are addressable. Note that STMT needs the
1967 address of this operand. */
1968 if (!allows_reg
&& allows_mem
)
1970 tree t
= get_base_address (TREE_VALUE (link
));
1971 if (t
&& DECL_P (t
) && s_ann
)
1972 add_to_addressable_set (t
, &s_ann
->addresses_taken
);
1975 get_expr_operands (stmt
, &TREE_VALUE (link
), opf_def
);
1978 /* Gather all input operands. */
1979 for (link
= ASM_INPUTS (stmt
); link
; link
= TREE_CHAIN (link
))
1981 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
1982 parse_input_constraint (&constraint
, 0, 0, noutputs
, 0, oconstraints
,
1983 &allows_mem
, &allows_reg
);
1985 /* Memory operands are addressable. Note that STMT needs the
1986 address of this operand. */
1987 if (!allows_reg
&& allows_mem
)
1989 tree t
= get_base_address (TREE_VALUE (link
));
1990 if (t
&& DECL_P (t
) && s_ann
)
1991 add_to_addressable_set (t
, &s_ann
->addresses_taken
);
1994 get_expr_operands (stmt
, &TREE_VALUE (link
), 0);
1997 /* Clobber all memory and addressable symbols for asm ("" : : : "memory"); */
1998 for (link
= ASM_CLOBBERS (stmt
); link
; link
= TREE_CHAIN (link
))
1999 if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link
)), "memory") == 0)
2004 s_ann
->references_memory
= true;
2006 EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun
), 0, i
, bi
)
2008 tree var
= referenced_var (i
);
2009 add_stmt_operand (&var
, s_ann
, opf_def
| opf_implicit
);
2012 EXECUTE_IF_SET_IN_BITMAP (gimple_addressable_vars (cfun
), 0, i
, bi
)
2014 tree var
= referenced_var (i
);
2016 /* Subvars are explicitly represented in this list, so we
2017 don't need the original to be added to the clobber ops,
2018 but the original *will* be in this list because we keep
2019 the addressability of the original variable up-to-date
2020 to avoid confusing the back-end. */
2021 if (var_can_have_subvars (var
)
2022 && get_subvars_for_var (var
) != NULL
)
2025 add_stmt_operand (&var
, s_ann
, opf_def
| opf_implicit
);
2032 /* Scan operands for the assignment expression EXPR in statement STMT. */
2035 get_modify_stmt_operands (tree stmt
, tree expr
)
2037 /* First get operands from the RHS. */
2038 get_expr_operands (stmt
, &GIMPLE_STMT_OPERAND (expr
, 1), opf_use
);
2040 /* For the LHS, use a regular definition (opf_def) for GIMPLE
2041 registers. If the LHS is a store to memory, we will need
2042 a preserving definition (VDEF).
2044 Preserving definitions are those that modify a part of an
2045 aggregate object for which no subvars have been computed (or the
2046 reference does not correspond exactly to one of them). Stores
2047 through a pointer are also represented with VDEF operators.
2049 We used to distinguish between preserving and killing definitions.
2050 We always emit preserving definitions now. */
2051 get_expr_operands (stmt
, &GIMPLE_STMT_OPERAND (expr
, 0), opf_def
);
2055 /* Recursively scan the expression pointed to by EXPR_P in statement
2056 STMT. FLAGS is one of the OPF_* constants modifying how to
2057 interpret the operands found. */
2060 get_expr_operands (tree stmt
, tree
*expr_p
, int flags
)
2062 enum tree_code code
;
2063 enum tree_code_class codeclass
;
2064 tree expr
= *expr_p
;
2065 stmt_ann_t s_ann
= stmt_ann (stmt
);
2070 code
= TREE_CODE (expr
);
2071 codeclass
= TREE_CODE_CLASS (code
);
2076 /* Taking the address of a variable does not represent a
2077 reference to it, but the fact that the statement takes its
2078 address will be of interest to some passes (e.g. alias
2080 add_to_addressable_set (TREE_OPERAND (expr
, 0), &s_ann
->addresses_taken
);
2082 /* If the address is invariant, there may be no interesting
2083 variable references inside. */
2084 if (is_gimple_min_invariant (expr
))
2087 /* Otherwise, there may be variables referenced inside but there
2088 should be no VUSEs created, since the referenced objects are
2089 not really accessed. The only operands that we should find
2090 here are ARRAY_REF indices which will always be real operands
2091 (GIMPLE does not allow non-registers as array indices). */
2092 flags
|= opf_no_vops
;
2093 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2097 case STRUCT_FIELD_TAG
:
2098 case SYMBOL_MEMORY_TAG
:
2099 case NAME_MEMORY_TAG
:
2100 add_stmt_operand (expr_p
, s_ann
, flags
);
2109 /* Add the subvars for a variable, if it has subvars, to DEFS
2110 or USES. Otherwise, add the variable itself. Whether it
2111 goes to USES or DEFS depends on the operand flags. */
2112 if (var_can_have_subvars (expr
)
2113 && (svars
= get_subvars_for_var (expr
)))
2116 for (sv
= svars
; sv
; sv
= sv
->next
)
2117 add_stmt_operand (&sv
->var
, s_ann
, flags
);
2120 add_stmt_operand (expr_p
, s_ann
, flags
);
2125 case MISALIGNED_INDIRECT_REF
:
2126 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), flags
);
2129 case ALIGN_INDIRECT_REF
:
2131 get_indirect_ref_operands (stmt
, expr
, flags
, NULL_TREE
, 0, -1, true);
2134 case TARGET_MEM_REF
:
2135 get_tmr_operands (stmt
, expr
, flags
);
2139 case ARRAY_RANGE_REF
:
2145 HOST_WIDE_INT offset
, size
, maxsize
;
2148 /* This component reference becomes an access to all of the
2149 subvariables it can touch, if we can determine that, but
2150 *NOT* the real one. If we can't determine which fields we
2151 could touch, the recursion will eventually get to a
2152 variable and add *all* of its subvars, or whatever is the
2153 minimum correct subset. */
2154 ref
= get_ref_base_and_extent (expr
, &offset
, &size
, &maxsize
);
2155 if (SSA_VAR_P (ref
) && get_subvars_for_var (ref
))
2158 subvar_t svars
= get_subvars_for_var (ref
);
2160 for (sv
= svars
; sv
; sv
= sv
->next
)
2164 if (overlap_subvar (offset
, maxsize
, sv
->var
, &exact
))
2166 int subvar_flags
= flags
;
2168 add_stmt_operand (&sv
->var
, s_ann
, subvar_flags
);
2173 flags
|= opf_no_vops
;
2175 else if (TREE_CODE (ref
) == INDIRECT_REF
)
2177 get_indirect_ref_operands (stmt
, ref
, flags
, expr
, offset
,
2179 flags
|= opf_no_vops
;
2182 /* Even if we found subvars above we need to ensure to see
2183 immediate uses for d in s.a[d]. In case of s.a having
2184 a subvar or we would miss it otherwise. */
2185 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2187 if (code
== COMPONENT_REF
)
2189 if (s_ann
&& TREE_THIS_VOLATILE (TREE_OPERAND (expr
, 1)))
2190 s_ann
->has_volatile_ops
= true;
2191 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), opf_use
);
2193 else if (code
== ARRAY_REF
|| code
== ARRAY_RANGE_REF
)
2195 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), opf_use
);
2196 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), opf_use
);
2197 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 3), opf_use
);
2203 case WITH_SIZE_EXPR
:
2204 /* WITH_SIZE_EXPR is a pass-through reference to its first argument,
2205 and an rvalue reference to its second argument. */
2206 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), opf_use
);
2207 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2211 get_call_expr_operands (stmt
, expr
);
2216 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), opf_use
);
2217 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), opf_use
);
2218 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), opf_use
);
2221 case GIMPLE_MODIFY_STMT
:
2222 get_modify_stmt_operands (stmt
, expr
);
2227 /* General aggregate CONSTRUCTORs have been decomposed, but they
2228 are still in use as the COMPLEX_EXPR equivalent for vectors. */
2229 constructor_elt
*ce
;
2230 unsigned HOST_WIDE_INT idx
;
2233 VEC_iterate (constructor_elt
, CONSTRUCTOR_ELTS (expr
), idx
, ce
);
2235 get_expr_operands (stmt
, &ce
->value
, opf_use
);
2241 case TRUTH_NOT_EXPR
:
2242 case VIEW_CONVERT_EXPR
:
2244 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2247 case TRUTH_AND_EXPR
:
2249 case TRUTH_XOR_EXPR
:
2255 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2256 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), flags
);
2261 case REALIGN_LOAD_EXPR
:
2263 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2264 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), flags
);
2265 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), flags
);
2269 case CHANGE_DYNAMIC_TYPE_EXPR
:
2270 get_expr_operands (stmt
, &CHANGE_DYNAMIC_TYPE_LOCATION (expr
), opf_use
);
2288 /* Expressions that make no memory references. */
2292 if (codeclass
== tcc_unary
)
2294 if (codeclass
== tcc_binary
|| codeclass
== tcc_comparison
)
2296 if (codeclass
== tcc_constant
|| codeclass
== tcc_type
)
2300 /* If we get here, something has gone wrong. */
2301 #ifdef ENABLE_CHECKING
2302 fprintf (stderr
, "unhandled expression in get_expr_operands():\n");
2304 fputs ("\n", stderr
);
2310 /* Parse STMT looking for operands. When finished, the various
2311 build_* operand vectors will have potential operands in them. */
2314 parse_ssa_operands (tree stmt
)
2316 enum tree_code code
;
2318 code
= TREE_CODE (stmt
);
2321 case GIMPLE_MODIFY_STMT
:
2322 get_modify_stmt_operands (stmt
, stmt
);
2326 get_expr_operands (stmt
, &COND_EXPR_COND (stmt
), opf_use
);
2330 get_expr_operands (stmt
, &SWITCH_COND (stmt
), opf_use
);
2334 get_asm_expr_operands (stmt
);
2338 get_expr_operands (stmt
, &TREE_OPERAND (stmt
, 0), opf_use
);
2342 get_expr_operands (stmt
, &GOTO_DESTINATION (stmt
), opf_use
);
2346 get_expr_operands (stmt
, &LABEL_EXPR_LABEL (stmt
), opf_use
);
2350 case CASE_LABEL_EXPR
:
2351 case TRY_CATCH_EXPR
:
2352 case TRY_FINALLY_EXPR
:
2353 case EH_FILTER_EXPR
:
2356 /* These nodes contain no variable references. */
2360 /* Notice that if get_expr_operands tries to use &STMT as the
2361 operand pointer (which may only happen for USE operands), we
2362 will fail in add_stmt_operand. This default will handle
2363 statements like empty statements, or CALL_EXPRs that may
2364 appear on the RHS of a statement or as statements themselves. */
2365 get_expr_operands (stmt
, &stmt
, opf_use
);
2371 /* Create an operands cache for STMT. */
2374 build_ssa_operands (tree stmt
)
2376 stmt_ann_t ann
= get_stmt_ann (stmt
);
2378 /* Initially assume that the statement has no volatile operands and
2379 makes no memory references. */
2380 ann
->has_volatile_ops
= false;
2381 ann
->references_memory
= false;
2382 /* Just clear the bitmap so we don't end up reallocating it over and over. */
2383 if (ann
->addresses_taken
)
2384 bitmap_clear (ann
->addresses_taken
);
2386 start_ssa_stmt_operands ();
2387 parse_ssa_operands (stmt
);
2388 operand_build_sort_virtual (build_vuses
);
2389 operand_build_sort_virtual (build_vdefs
);
2390 finalize_ssa_stmt_operands (stmt
);
2392 if (ann
->addresses_taken
&& bitmap_empty_p (ann
->addresses_taken
))
2393 ann
->addresses_taken
= NULL
;
2394 /* For added safety, assume that statements with volatile operands
2395 also reference memory. */
2396 if (ann
->has_volatile_ops
)
2397 ann
->references_memory
= true;
2401 /* Free any operands vectors in OPS. */
2404 free_ssa_operands (stmt_operands_p ops
)
2406 ops
->def_ops
= NULL
;
2407 ops
->use_ops
= NULL
;
2408 ops
->vdef_ops
= NULL
;
2409 ops
->vuse_ops
= NULL
;
2410 BITMAP_FREE (ops
->loads
);
2411 BITMAP_FREE (ops
->stores
);
2415 /* Get the operands of statement STMT. */
2418 update_stmt_operands (tree stmt
)
2420 stmt_ann_t ann
= get_stmt_ann (stmt
);
2422 /* If update_stmt_operands is called before SSA is initialized, do
2424 if (!ssa_operands_active ())
2427 /* The optimizers cannot handle statements that are nothing but a
2428 _DECL. This indicates a bug in the gimplifier. */
2429 gcc_assert (!SSA_VAR_P (stmt
));
2431 timevar_push (TV_TREE_OPS
);
2433 gcc_assert (ann
->modified
);
2434 build_ssa_operands (stmt
);
2437 timevar_pop (TV_TREE_OPS
);
2441 /* Copies virtual operands from SRC to DST. */
2444 copy_virtual_operands (tree dest
, tree src
)
2447 voptype_p src_vuses
, dest_vuses
;
2448 voptype_p src_vdefs
, dest_vdefs
;
2449 struct voptype_d vuse
;
2450 struct voptype_d vdef
;
2451 stmt_ann_t dest_ann
;
2453 VDEF_OPS (dest
) = NULL
;
2454 VUSE_OPS (dest
) = NULL
;
2456 dest_ann
= get_stmt_ann (dest
);
2457 BITMAP_FREE (dest_ann
->operands
.loads
);
2458 BITMAP_FREE (dest_ann
->operands
.stores
);
2460 if (LOADED_SYMS (src
))
2462 dest_ann
->operands
.loads
= BITMAP_ALLOC (&operands_bitmap_obstack
);
2463 bitmap_copy (dest_ann
->operands
.loads
, LOADED_SYMS (src
));
2466 if (STORED_SYMS (src
))
2468 dest_ann
->operands
.stores
= BITMAP_ALLOC (&operands_bitmap_obstack
);
2469 bitmap_copy (dest_ann
->operands
.stores
, STORED_SYMS (src
));
2472 /* Copy all the VUSE operators and corresponding operands. */
2474 for (src_vuses
= VUSE_OPS (src
); src_vuses
; src_vuses
= src_vuses
->next
)
2476 n
= VUSE_NUM (src_vuses
);
2477 dest_vuses
= add_vuse_op (dest
, NULL_TREE
, n
, dest_vuses
);
2478 for (i
= 0; i
< n
; i
++)
2479 SET_USE (VUSE_OP_PTR (dest_vuses
, i
), VUSE_OP (src_vuses
, i
));
2481 if (VUSE_OPS (dest
) == NULL
)
2482 VUSE_OPS (dest
) = vuse
.next
;
2485 /* Copy all the VDEF operators and corresponding operands. */
2487 for (src_vdefs
= VDEF_OPS (src
); src_vdefs
; src_vdefs
= src_vdefs
->next
)
2489 n
= VUSE_NUM (src_vdefs
);
2490 dest_vdefs
= add_vdef_op (dest
, NULL_TREE
, n
, dest_vdefs
);
2491 VDEF_RESULT (dest_vdefs
) = VDEF_RESULT (src_vdefs
);
2492 for (i
= 0; i
< n
; i
++)
2493 SET_USE (VUSE_OP_PTR (dest_vdefs
, i
), VUSE_OP (src_vdefs
, i
));
2495 if (VDEF_OPS (dest
) == NULL
)
2496 VDEF_OPS (dest
) = vdef
.next
;
2501 /* Specifically for use in DOM's expression analysis. Given a store, we
2502 create an artificial stmt which looks like a load from the store, this can
2503 be used to eliminate redundant loads. OLD_OPS are the operands from the
2504 store stmt, and NEW_STMT is the new load which represents a load of the
2508 create_ssa_artificial_load_stmt (tree new_stmt
, tree old_stmt
)
2512 use_operand_p use_p
;
2515 get_stmt_ann (new_stmt
);
2517 /* Process NEW_STMT looking for operands. */
2518 start_ssa_stmt_operands ();
2519 parse_ssa_operands (new_stmt
);
2521 for (i
= 0; VEC_iterate (tree
, build_vuses
, i
, op
); i
++)
2522 if (TREE_CODE (op
) != SSA_NAME
)
2523 var_ann (op
)->in_vuse_list
= false;
2525 for (i
= 0; VEC_iterate (tree
, build_vuses
, i
, op
); i
++)
2526 if (TREE_CODE (op
) != SSA_NAME
)
2527 var_ann (op
)->in_vdef_list
= false;
2529 /* Remove any virtual operands that were found. */
2530 VEC_truncate (tree
, build_vdefs
, 0);
2531 VEC_truncate (tree
, build_vuses
, 0);
2533 /* For each VDEF on the original statement, we want to create a
2534 VUSE of the VDEF result operand on the new statement. */
2535 FOR_EACH_SSA_TREE_OPERAND (op
, old_stmt
, iter
, SSA_OP_VDEF
)
2538 finalize_ssa_stmt_operands (new_stmt
);
2540 /* All uses in this fake stmt must not be in the immediate use lists. */
2541 FOR_EACH_SSA_USE_OPERAND (use_p
, new_stmt
, iter
, SSA_OP_ALL_USES
)
2542 delink_imm_use (use_p
);
2546 /* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done
2547 to test the validity of the swap operation. */
2550 swap_tree_operands (tree stmt
, tree
*exp0
, tree
*exp1
)
2556 /* If the operand cache is active, attempt to preserve the relative
2557 positions of these two operands in their respective immediate use
2559 if (ssa_operands_active () && op0
!= op1
)
2561 use_optype_p use0
, use1
, ptr
;
2564 /* Find the 2 operands in the cache, if they are there. */
2565 for (ptr
= USE_OPS (stmt
); ptr
; ptr
= ptr
->next
)
2566 if (USE_OP_PTR (ptr
)->use
== exp0
)
2572 for (ptr
= USE_OPS (stmt
); ptr
; ptr
= ptr
->next
)
2573 if (USE_OP_PTR (ptr
)->use
== exp1
)
2579 /* If both uses don't have operand entries, there isn't much we can do
2580 at this point. Presumably we don't need to worry about it. */
2583 tree
*tmp
= USE_OP_PTR (use1
)->use
;
2584 USE_OP_PTR (use1
)->use
= USE_OP_PTR (use0
)->use
;
2585 USE_OP_PTR (use0
)->use
= tmp
;
2589 /* Now swap the data. */
2595 /* Add the base address of REF to the set *ADDRESSES_TAKEN. If
2596 *ADDRESSES_TAKEN is NULL, a new set is created. REF may be
2597 a single variable whose address has been taken or any other valid
2598 GIMPLE memory reference (structure reference, array, etc). If the
2599 base address of REF is a decl that has sub-variables, also add all
2600 of its sub-variables. */
2603 add_to_addressable_set (tree ref
, bitmap
*addresses_taken
)
2608 gcc_assert (addresses_taken
);
2610 /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF
2611 as the only thing we take the address of. If VAR is a structure,
2612 taking the address of a field means that the whole structure may
2613 be referenced using pointer arithmetic. See PR 21407 and the
2614 ensuing mailing list discussion. */
2615 var
= get_base_address (ref
);
2616 if (var
&& SSA_VAR_P (var
))
2618 if (*addresses_taken
== NULL
)
2619 *addresses_taken
= BITMAP_GGC_ALLOC ();
2621 if (var_can_have_subvars (var
)
2622 && (svars
= get_subvars_for_var (var
)))
2625 for (sv
= svars
; sv
; sv
= sv
->next
)
2627 bitmap_set_bit (*addresses_taken
, DECL_UID (sv
->var
));
2628 TREE_ADDRESSABLE (sv
->var
) = 1;
2633 bitmap_set_bit (*addresses_taken
, DECL_UID (var
));
2634 TREE_ADDRESSABLE (var
) = 1;
2640 /* Scan the immediate_use list for VAR making sure its linked properly.
2641 Return TRUE if there is a problem and emit an error message to F. */
2644 verify_imm_links (FILE *f
, tree var
)
2646 use_operand_p ptr
, prev
, list
;
2649 gcc_assert (TREE_CODE (var
) == SSA_NAME
);
2651 list
= &(SSA_NAME_IMM_USE_NODE (var
));
2652 gcc_assert (list
->use
== NULL
);
2654 if (list
->prev
== NULL
)
2656 gcc_assert (list
->next
== NULL
);
2662 for (ptr
= list
->next
; ptr
!= list
; )
2664 if (prev
!= ptr
->prev
)
2667 if (ptr
->use
== NULL
)
2668 goto error
; /* 2 roots, or SAFE guard node. */
2669 else if (*(ptr
->use
) != var
)
2675 /* Avoid infinite loops. 50,000,000 uses probably indicates a
2677 if (count
++ > 50000000)
2681 /* Verify list in the other direction. */
2683 for (ptr
= list
->prev
; ptr
!= list
; )
2685 if (prev
!= ptr
->next
)
2699 if (ptr
->stmt
&& stmt_modified_p (ptr
->stmt
))
2701 fprintf (f
, " STMT MODIFIED. - <%p> ", (void *)ptr
->stmt
);
2702 print_generic_stmt (f
, ptr
->stmt
, TDF_SLIM
);
2704 fprintf (f
, " IMM ERROR : (use_p : tree - %p:%p)", (void *)ptr
,
2706 print_generic_expr (f
, USE_FROM_PTR (ptr
), TDF_SLIM
);
2712 /* Dump all the immediate uses to FILE. */
2715 dump_immediate_uses_for (FILE *file
, tree var
)
2717 imm_use_iterator iter
;
2718 use_operand_p use_p
;
2720 gcc_assert (var
&& TREE_CODE (var
) == SSA_NAME
);
2722 print_generic_expr (file
, var
, TDF_SLIM
);
2723 fprintf (file
, " : -->");
2724 if (has_zero_uses (var
))
2725 fprintf (file
, " no uses.\n");
2727 if (has_single_use (var
))
2728 fprintf (file
, " single use.\n");
2730 fprintf (file
, "%d uses.\n", num_imm_uses (var
));
2732 FOR_EACH_IMM_USE_FAST (use_p
, iter
, var
)
2734 if (use_p
->stmt
== NULL
&& use_p
->use
== NULL
)
2735 fprintf (file
, "***end of stmt iterator marker***\n");
2737 if (!is_gimple_reg (USE_FROM_PTR (use_p
)))
2738 print_generic_stmt (file
, USE_STMT (use_p
), TDF_VOPS
|TDF_MEMSYMS
);
2740 print_generic_stmt (file
, USE_STMT (use_p
), TDF_SLIM
);
2742 fprintf(file
, "\n");
2746 /* Dump all the immediate uses to FILE. */
2749 dump_immediate_uses (FILE *file
)
2754 fprintf (file
, "Immediate_uses: \n\n");
2755 for (x
= 1; x
< num_ssa_names
; x
++)
2760 dump_immediate_uses_for (file
, var
);
2765 /* Dump def-use edges on stderr. */
2768 debug_immediate_uses (void)
2770 dump_immediate_uses (stderr
);
2774 /* Dump def-use edges on stderr. */
2777 debug_immediate_uses_for (tree var
)
2779 dump_immediate_uses_for (stderr
, var
);
2783 /* Create a new change buffer for the statement pointed by STMT_P and
2784 push the buffer into SCB_STACK. Each change buffer
2785 records state information needed to determine what changed in the
2786 statement. Mainly, this keeps track of symbols that may need to be
2787 put into SSA form, SSA name replacements and other information
2788 needed to keep the SSA form up to date. */
2791 push_stmt_changes (tree
*stmt_p
)
2798 /* It makes no sense to keep track of PHI nodes. */
2799 if (TREE_CODE (stmt
) == PHI_NODE
)
2802 buf
= XNEW (struct scb_d
);
2803 memset (buf
, 0, sizeof *buf
);
2805 buf
->stmt_p
= stmt_p
;
2807 if (stmt_references_memory_p (stmt
))
2812 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_VUSE
)
2814 tree sym
= TREE_CODE (op
) == SSA_NAME
? SSA_NAME_VAR (op
) : op
;
2815 if (buf
->loads
== NULL
)
2816 buf
->loads
= BITMAP_ALLOC (NULL
);
2817 bitmap_set_bit (buf
->loads
, DECL_UID (sym
));
2820 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_VDEF
)
2822 tree sym
= TREE_CODE (op
) == SSA_NAME
? SSA_NAME_VAR (op
) : op
;
2823 if (buf
->stores
== NULL
)
2824 buf
->stores
= BITMAP_ALLOC (NULL
);
2825 bitmap_set_bit (buf
->stores
, DECL_UID (sym
));
2829 VEC_safe_push (scb_t
, heap
, scb_stack
, buf
);
2833 /* Given two sets S1 and S2, mark the symbols that differ in S1 and S2
2834 for renaming. The set to mark for renaming is (S1 & ~S2) | (S2 & ~S1). */
2837 mark_difference_for_renaming (bitmap s1
, bitmap s2
)
2839 if (s1
== NULL
&& s2
== NULL
)
2842 if (s1
&& s2
== NULL
)
2843 mark_set_for_renaming (s1
);
2844 else if (s1
== NULL
&& s2
)
2845 mark_set_for_renaming (s2
);
2846 else if (!bitmap_equal_p (s1
, s2
))
2848 bitmap t1
= BITMAP_ALLOC (NULL
);
2849 bitmap t2
= BITMAP_ALLOC (NULL
);
2851 bitmap_and_compl (t1
, s1
, s2
);
2852 bitmap_and_compl (t2
, s2
, s1
);
2853 bitmap_ior_into (t1
, t2
);
2854 mark_set_for_renaming (t1
);
2862 /* Pop the top SCB from SCB_STACK and act on the differences between
2863 what was recorded by push_stmt_changes and the current state of
2867 pop_stmt_changes (tree
*stmt_p
)
2871 bitmap loads
, stores
;
2876 /* It makes no sense to keep track of PHI nodes. */
2877 if (TREE_CODE (stmt
) == PHI_NODE
)
2880 buf
= VEC_pop (scb_t
, scb_stack
);
2881 gcc_assert (stmt_p
== buf
->stmt_p
);
2883 /* Force an operand re-scan on the statement and mark any newly
2884 exposed variables. */
2887 /* Determine whether any memory symbols need to be renamed. If the
2888 sets of loads and stores are different after the statement is
2889 modified, then the affected symbols need to be renamed.
2891 Note that it may be possible for the statement to not reference
2892 memory anymore, but we still need to act on the differences in
2893 the sets of symbols. */
2894 loads
= stores
= NULL
;
2895 if (stmt_references_memory_p (stmt
))
2900 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_VUSE
)
2902 tree sym
= TREE_CODE (op
) == SSA_NAME
? SSA_NAME_VAR (op
) : op
;
2904 loads
= BITMAP_ALLOC (NULL
);
2905 bitmap_set_bit (loads
, DECL_UID (sym
));
2908 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_VDEF
)
2910 tree sym
= TREE_CODE (op
) == SSA_NAME
? SSA_NAME_VAR (op
) : op
;
2912 stores
= BITMAP_ALLOC (NULL
);
2913 bitmap_set_bit (stores
, DECL_UID (sym
));
2917 /* If LOADS is different from BUF->LOADS, the affected
2918 symbols need to be marked for renaming. */
2919 mark_difference_for_renaming (loads
, buf
->loads
);
2921 /* Similarly for STORES and BUF->STORES. */
2922 mark_difference_for_renaming (stores
, buf
->stores
);
2924 /* Mark all the naked GIMPLE register operands for renaming. */
2925 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
|SSA_OP_USE
)
2927 mark_sym_for_renaming (op
);
2929 /* FIXME, need to add more finalizers here. Cleanup EH info,
2930 recompute invariants for address expressions, add
2931 SSA replacement mappings, etc. For instance, given
2932 testsuite/gcc.c-torture/compile/pr16808.c, we fold a statement of
2935 # SMT.4_20 = VDEF <SMT.4_16>
2938 So, the VDEF will disappear, but instead of marking SMT.4 for
2939 renaming it would be far more efficient to establish a
2940 replacement mapping that would replace every reference of
2941 SMT.4_20 with SMT.4_16. */
2943 /* Free memory used by the buffer. */
2944 BITMAP_FREE (buf
->loads
);
2945 BITMAP_FREE (buf
->stores
);
2946 BITMAP_FREE (loads
);
2947 BITMAP_FREE (stores
);
2953 /* Discard the topmost change buffer from SCB_STACK. This is useful
2954 when the caller realized that it did not actually modified the
2955 statement. It avoids the expensive operand re-scan. */
2958 discard_stmt_changes (tree
*stmt_p
)
2963 /* It makes no sense to keep track of PHI nodes. */
2965 if (TREE_CODE (stmt
) == PHI_NODE
)
2968 buf
= VEC_pop (scb_t
, scb_stack
);
2969 gcc_assert (stmt_p
== buf
->stmt_p
);
2971 /* Free memory used by the buffer. */
2972 BITMAP_FREE (buf
->loads
);
2973 BITMAP_FREE (buf
->stores
);
2979 /* Returns true if statement STMT may access memory. */
2982 stmt_references_memory_p (tree stmt
)
2984 if (!gimple_ssa_operands (cfun
)->ops_active
|| TREE_CODE (stmt
) == PHI_NODE
)
2987 return stmt_ann (stmt
)->references_memory
;