1 /* Scalar Replacement of Aggregates (SRA) converts some structure
2 references into scalar references, exposing them to the scalar
4 Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
5 Contributed by Martin Jambor <mjambor@suse.cz>
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* This file implements Scalar Reduction of Aggregates (SRA). SRA is run
24 twice, once in the early stages of compilation (early SRA) and once in the
25 late stages (late SRA). The aim of both is to turn references to scalar
26 parts of aggregates into uses of independent scalar variables.
28 The two passes are nearly identical, the only difference is that early SRA
29 does not scalarize unions which are used as the result in a GIMPLE_RETURN
30 statement because together with inlining this can lead to weird type
33 Both passes operate in four stages:
35 1. The declarations that have properties which make them candidates for
36 scalarization are identified in function find_var_candidates(). The
37 candidates are stored in candidate_bitmap.
39 2. The function body is scanned. In the process, declarations which are
40 used in a manner that prevent their scalarization are removed from the
41 candidate bitmap. More importantly, for every access into an aggregate,
42 an access structure (struct access) is created by create_access() and
43 stored in a vector associated with the aggregate. Among other
44 information, the aggregate declaration, the offset and size of the access
45 and its type are stored in the structure.
47 On a related note, assign_link structures are created for every assign
48 statement between candidate aggregates and attached to the related
51 3. The vectors of accesses are analyzed. They are first sorted according to
52 their offset and size and then scanned for partially overlapping accesses
53 (i.e. those which overlap but one is not entirely within another). Such
54 an access disqualifies the whole aggregate from being scalarized.
56 If there is no such inhibiting overlap, a representative access structure
57 is chosen for every unique combination of offset and size. Afterwards,
58 the pass builds a set of trees from these structures, in which children
59 of an access are within their parent (in terms of offset and size).
61 Then accesses are propagated whenever possible (i.e. in cases when it
62 does not create a partially overlapping access) across assign_links from
63 the right hand side to the left hand side.
65 Then the set of trees for each declaration is traversed again and those
66 accesses which should be replaced by a scalar are identified.
68 4. The function is traversed again, and for every reference into an
69 aggregate that has some component which is about to be scalarized,
70 statements are amended and new statements are created as necessary.
71 Finally, if a parameter got scalarized, the scalar replacements are
72 initialized with values from respective parameter aggregates. */
76 #include "coretypes.h"
77 #include "alloc-pool.h"
83 #include "tree-flow.h"
85 #include "tree-pretty-print.h"
86 #include "statistics.h"
87 #include "tree-dump.h"
93 #include "tree-inline.h"
94 #include "gimple-pretty-print.h"
96 /* Enumeration of all aggregate reductions we can do. */
97 enum sra_mode
{ SRA_MODE_EARLY_IPA
, /* early call regularization */
98 SRA_MODE_EARLY_INTRA
, /* early intraprocedural SRA */
99 SRA_MODE_INTRA
}; /* late intraprocedural SRA */
101 /* Global variable describing which aggregate reduction we are performing at
103 static enum sra_mode sra_mode
;
107 /* ACCESS represents each access to an aggregate variable (as a whole or a
108 part). It can also represent a group of accesses that refer to exactly the
109 same fragment of an aggregate (i.e. those that have exactly the same offset
110 and size). Such representatives for a single aggregate, once determined,
111 are linked in a linked list and have the group fields set.
113 Moreover, when doing intraprocedural SRA, a tree is built from those
114 representatives (by the means of first_child and next_sibling pointers), in
115 which all items in a subtree are "within" the root, i.e. their offset is
116 greater or equal to offset of the root and offset+size is smaller or equal
117 to offset+size of the root. Children of an access are sorted by offset.
119 Note that accesses to parts of vector and complex number types always
120 represented by an access to the whole complex number or a vector. It is a
121 duty of the modifying functions to replace them appropriately. */
125 /* Values returned by `get_ref_base_and_extent' for each component reference
126 If EXPR isn't a component reference just set `BASE = EXPR', `OFFSET = 0',
127 `SIZE = TREE_SIZE (TREE_TYPE (expr))'. */
128 HOST_WIDE_INT offset
;
132 /* Expression. It is context dependent so do not use it to create new
133 expressions to access the original aggregate. See PR 42154 for a
139 /* The statement this access belongs to. */
142 /* Next group representative for this aggregate. */
143 struct access
*next_grp
;
145 /* Pointer to the group representative. Pointer to itself if the struct is
146 the representative. */
147 struct access
*group_representative
;
149 /* If this access has any children (in terms of the definition above), this
150 points to the first one. */
151 struct access
*first_child
;
153 /* In intraprocedural SRA, pointer to the next sibling in the access tree as
154 described above. In IPA-SRA this is a pointer to the next access
155 belonging to the same group (having the same representative). */
156 struct access
*next_sibling
;
158 /* Pointers to the first and last element in the linked list of assign
160 struct assign_link
*first_link
, *last_link
;
162 /* Pointer to the next access in the work queue. */
163 struct access
*next_queued
;
165 /* Replacement variable for this access "region." Never to be accessed
166 directly, always only by the means of get_access_replacement() and only
167 when grp_to_be_replaced flag is set. */
168 tree replacement_decl
;
170 /* Is this particular access write access? */
173 /* Is this access an artificial one created to scalarize some record
175 unsigned total_scalarization
: 1;
177 /* Is this access currently in the work queue? */
178 unsigned grp_queued
: 1;
180 /* Does this group contain a write access? This flag is propagated down the
182 unsigned grp_write
: 1;
184 /* Does this group contain a read access? This flag is propagated down the
186 unsigned grp_read
: 1;
188 /* Does this group contain a read access that comes from an assignment
189 statement? This flag is propagated down the access tree. */
190 unsigned grp_assignment_read
: 1;
192 /* Does this group contain a write access that comes from an assignment
193 statement? This flag is propagated down the access tree. */
194 unsigned grp_assignment_write
: 1;
196 /* Other passes of the analysis use this bit to make function
197 analyze_access_subtree create scalar replacements for this group if
199 unsigned grp_hint
: 1;
201 /* Is the subtree rooted in this access fully covered by scalar
203 unsigned grp_covered
: 1;
205 /* If set to true, this access and all below it in an access tree must not be
207 unsigned grp_unscalarizable_region
: 1;
209 /* Whether data have been written to parts of the aggregate covered by this
210 access which is not to be scalarized. This flag is propagated up in the
212 unsigned grp_unscalarized_data
: 1;
214 /* Does this access and/or group contain a write access through a
216 unsigned grp_partial_lhs
: 1;
218 /* Set when a scalar replacement should be created for this variable. We do
219 the decision and creation at different places because create_tmp_var
220 cannot be called from within FOR_EACH_REFERENCED_VAR. */
221 unsigned grp_to_be_replaced
: 1;
223 /* Should TREE_NO_WARNING of a replacement be set? */
224 unsigned grp_no_warning
: 1;
226 /* Is it possible that the group refers to data which might be (directly or
227 otherwise) modified? */
228 unsigned grp_maybe_modified
: 1;
230 /* Set when this is a representative of a pointer to scalar (i.e. by
231 reference) parameter which we consider for turning into a plain scalar
232 (i.e. a by value parameter). */
233 unsigned grp_scalar_ptr
: 1;
235 /* Set when we discover that this pointer is not safe to dereference in the
237 unsigned grp_not_necessarilly_dereferenced
: 1;
240 typedef struct access
*access_p
;
242 DEF_VEC_P (access_p
);
243 DEF_VEC_ALLOC_P (access_p
, heap
);
245 /* Alloc pool for allocating access structures. */
246 static alloc_pool access_pool
;
248 /* A structure linking lhs and rhs accesses from an aggregate assignment. They
249 are used to propagate subaccesses from rhs to lhs as long as they don't
250 conflict with what is already there. */
253 struct access
*lacc
, *racc
;
254 struct assign_link
*next
;
257 /* Alloc pool for allocating assign link structures. */
258 static alloc_pool link_pool
;
260 /* Base (tree) -> Vector (VEC(access_p,heap) *) map. */
261 static struct pointer_map_t
*base_access_vec
;
263 /* Bitmap of candidates. */
264 static bitmap candidate_bitmap
;
266 /* Bitmap of candidates which we should try to entirely scalarize away and
267 those which cannot be (because they are and need be used as a whole). */
268 static bitmap should_scalarize_away_bitmap
, cannot_scalarize_away_bitmap
;
270 /* Obstack for creation of fancy names. */
271 static struct obstack name_obstack
;
273 /* Head of a linked list of accesses that need to have its subaccesses
274 propagated to their assignment counterparts. */
275 static struct access
*work_queue_head
;
277 /* Number of parameters of the analyzed function when doing early ipa SRA. */
278 static int func_param_count
;
280 /* scan_function sets the following to true if it encounters a call to
281 __builtin_apply_args. */
282 static bool encountered_apply_args
;
284 /* Set by scan_function when it finds a recursive call. */
285 static bool encountered_recursive_call
;
287 /* Set by scan_function when it finds a recursive call with less actual
288 arguments than formal parameters.. */
289 static bool encountered_unchangable_recursive_call
;
291 /* This is a table in which for each basic block and parameter there is a
292 distance (offset + size) in that parameter which is dereferenced and
293 accessed in that BB. */
294 static HOST_WIDE_INT
*bb_dereferences
;
295 /* Bitmap of BBs that can cause the function to "stop" progressing by
296 returning, throwing externally, looping infinitely or calling a function
297 which might abort etc.. */
298 static bitmap final_bbs
;
300 /* Representative of no accesses at all. */
301 static struct access no_accesses_representant
;
303 /* Predicate to test the special value. */
306 no_accesses_p (struct access
*access
)
308 return access
== &no_accesses_representant
;
311 /* Dump contents of ACCESS to file F in a human friendly way. If GRP is true,
312 representative fields are dumped, otherwise those which only describe the
313 individual access are. */
317 /* Number of processed aggregates is readily available in
318 analyze_all_variable_accesses and so is not stored here. */
320 /* Number of created scalar replacements. */
323 /* Number of times sra_modify_expr or sra_modify_assign themselves changed an
327 /* Number of statements created by generate_subtree_copies. */
330 /* Number of statements created by load_assign_lhs_subreplacements. */
333 /* Number of times sra_modify_assign has deleted a statement. */
336 /* Number of times sra_modify_assign has to deal with subaccesses of LHS and
337 RHS reparately due to type conversions or nonexistent matching
339 int separate_lhs_rhs_handling
;
341 /* Number of parameters that were removed because they were unused. */
342 int deleted_unused_parameters
;
344 /* Number of scalars passed as parameters by reference that have been
345 converted to be passed by value. */
346 int scalar_by_ref_to_by_val
;
348 /* Number of aggregate parameters that were replaced by one or more of their
350 int aggregate_params_reduced
;
352 /* Numbber of components created when splitting aggregate parameters. */
353 int param_reductions_created
;
357 dump_access (FILE *f
, struct access
*access
, bool grp
)
359 fprintf (f
, "access { ");
360 fprintf (f
, "base = (%d)'", DECL_UID (access
->base
));
361 print_generic_expr (f
, access
->base
, 0);
362 fprintf (f
, "', offset = " HOST_WIDE_INT_PRINT_DEC
, access
->offset
);
363 fprintf (f
, ", size = " HOST_WIDE_INT_PRINT_DEC
, access
->size
);
364 fprintf (f
, ", expr = ");
365 print_generic_expr (f
, access
->expr
, 0);
366 fprintf (f
, ", type = ");
367 print_generic_expr (f
, access
->type
, 0);
369 fprintf (f
, ", grp_write = %d, total_scalarization = %d, "
370 "grp_read = %d, grp_hint = %d, grp_assignment_read = %d,"
371 "grp_assignment_write = %d, grp_covered = %d, "
372 "grp_unscalarizable_region = %d, grp_unscalarized_data = %d, "
373 "grp_partial_lhs = %d, grp_to_be_replaced = %d, "
374 "grp_maybe_modified = %d, "
375 "grp_not_necessarilly_dereferenced = %d\n",
376 access
->grp_write
, access
->total_scalarization
,
377 access
->grp_read
, access
->grp_hint
, access
->grp_assignment_read
,
378 access
->grp_assignment_write
, access
->grp_covered
,
379 access
->grp_unscalarizable_region
, access
->grp_unscalarized_data
,
380 access
->grp_partial_lhs
, access
->grp_to_be_replaced
,
381 access
->grp_maybe_modified
,
382 access
->grp_not_necessarilly_dereferenced
);
384 fprintf (f
, ", write = %d, total_scalarization = %d, "
385 "grp_partial_lhs = %d\n",
386 access
->write
, access
->total_scalarization
,
387 access
->grp_partial_lhs
);
390 /* Dump a subtree rooted in ACCESS to file F, indent by LEVEL. */
393 dump_access_tree_1 (FILE *f
, struct access
*access
, int level
)
399 for (i
= 0; i
< level
; i
++)
400 fputs ("* ", dump_file
);
402 dump_access (f
, access
, true);
404 if (access
->first_child
)
405 dump_access_tree_1 (f
, access
->first_child
, level
+ 1);
407 access
= access
->next_sibling
;
412 /* Dump all access trees for a variable, given the pointer to the first root in
416 dump_access_tree (FILE *f
, struct access
*access
)
418 for (; access
; access
= access
->next_grp
)
419 dump_access_tree_1 (f
, access
, 0);
422 /* Return true iff ACC is non-NULL and has subaccesses. */
425 access_has_children_p (struct access
*acc
)
427 return acc
&& acc
->first_child
;
430 /* Return a vector of pointers to accesses for the variable given in BASE or
431 NULL if there is none. */
433 static VEC (access_p
, heap
) *
434 get_base_access_vector (tree base
)
438 slot
= pointer_map_contains (base_access_vec
, base
);
442 return *(VEC (access_p
, heap
) **) slot
;
445 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
446 in ACCESS. Return NULL if it cannot be found. */
448 static struct access
*
449 find_access_in_subtree (struct access
*access
, HOST_WIDE_INT offset
,
452 while (access
&& (access
->offset
!= offset
|| access
->size
!= size
))
454 struct access
*child
= access
->first_child
;
456 while (child
&& (child
->offset
+ child
->size
<= offset
))
457 child
= child
->next_sibling
;
464 /* Return the first group representative for DECL or NULL if none exists. */
466 static struct access
*
467 get_first_repr_for_decl (tree base
)
469 VEC (access_p
, heap
) *access_vec
;
471 access_vec
= get_base_access_vector (base
);
475 return VEC_index (access_p
, access_vec
, 0);
478 /* Find an access representative for the variable BASE and given OFFSET and
479 SIZE. Requires that access trees have already been built. Return NULL if
480 it cannot be found. */
482 static struct access
*
483 get_var_base_offset_size_access (tree base
, HOST_WIDE_INT offset
,
486 struct access
*access
;
488 access
= get_first_repr_for_decl (base
);
489 while (access
&& (access
->offset
+ access
->size
<= offset
))
490 access
= access
->next_grp
;
494 return find_access_in_subtree (access
, offset
, size
);
497 /* Add LINK to the linked list of assign links of RACC. */
499 add_link_to_rhs (struct access
*racc
, struct assign_link
*link
)
501 gcc_assert (link
->racc
== racc
);
503 if (!racc
->first_link
)
505 gcc_assert (!racc
->last_link
);
506 racc
->first_link
= link
;
509 racc
->last_link
->next
= link
;
511 racc
->last_link
= link
;
515 /* Move all link structures in their linked list in OLD_RACC to the linked list
518 relink_to_new_repr (struct access
*new_racc
, struct access
*old_racc
)
520 if (!old_racc
->first_link
)
522 gcc_assert (!old_racc
->last_link
);
526 if (new_racc
->first_link
)
528 gcc_assert (!new_racc
->last_link
->next
);
529 gcc_assert (!old_racc
->last_link
|| !old_racc
->last_link
->next
);
531 new_racc
->last_link
->next
= old_racc
->first_link
;
532 new_racc
->last_link
= old_racc
->last_link
;
536 gcc_assert (!new_racc
->last_link
);
538 new_racc
->first_link
= old_racc
->first_link
;
539 new_racc
->last_link
= old_racc
->last_link
;
541 old_racc
->first_link
= old_racc
->last_link
= NULL
;
544 /* Add ACCESS to the work queue (which is actually a stack). */
547 add_access_to_work_queue (struct access
*access
)
549 if (!access
->grp_queued
)
551 gcc_assert (!access
->next_queued
);
552 access
->next_queued
= work_queue_head
;
553 access
->grp_queued
= 1;
554 work_queue_head
= access
;
558 /* Pop an access from the work queue, and return it, assuming there is one. */
560 static struct access
*
561 pop_access_from_work_queue (void)
563 struct access
*access
= work_queue_head
;
565 work_queue_head
= access
->next_queued
;
566 access
->next_queued
= NULL
;
567 access
->grp_queued
= 0;
572 /* Allocate necessary structures. */
575 sra_initialize (void)
577 candidate_bitmap
= BITMAP_ALLOC (NULL
);
578 should_scalarize_away_bitmap
= BITMAP_ALLOC (NULL
);
579 cannot_scalarize_away_bitmap
= BITMAP_ALLOC (NULL
);
580 gcc_obstack_init (&name_obstack
);
581 access_pool
= create_alloc_pool ("SRA accesses", sizeof (struct access
), 16);
582 link_pool
= create_alloc_pool ("SRA links", sizeof (struct assign_link
), 16);
583 base_access_vec
= pointer_map_create ();
584 memset (&sra_stats
, 0, sizeof (sra_stats
));
585 encountered_apply_args
= false;
586 encountered_recursive_call
= false;
587 encountered_unchangable_recursive_call
= false;
590 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
593 delete_base_accesses (const void *key ATTRIBUTE_UNUSED
, void **value
,
594 void *data ATTRIBUTE_UNUSED
)
596 VEC (access_p
, heap
) *access_vec
;
597 access_vec
= (VEC (access_p
, heap
) *) *value
;
598 VEC_free (access_p
, heap
, access_vec
);
603 /* Deallocate all general structures. */
606 sra_deinitialize (void)
608 BITMAP_FREE (candidate_bitmap
);
609 BITMAP_FREE (should_scalarize_away_bitmap
);
610 BITMAP_FREE (cannot_scalarize_away_bitmap
);
611 free_alloc_pool (access_pool
);
612 free_alloc_pool (link_pool
);
613 obstack_free (&name_obstack
, NULL
);
615 pointer_map_traverse (base_access_vec
, delete_base_accesses
, NULL
);
616 pointer_map_destroy (base_access_vec
);
619 /* Remove DECL from candidates for SRA and write REASON to the dump file if
622 disqualify_candidate (tree decl
, const char *reason
)
624 bitmap_clear_bit (candidate_bitmap
, DECL_UID (decl
));
626 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
628 fprintf (dump_file
, "! Disqualifying ");
629 print_generic_expr (dump_file
, decl
, 0);
630 fprintf (dump_file
, " - %s\n", reason
);
634 /* Return true iff the type contains a field or an element which does not allow
638 type_internals_preclude_sra_p (tree type
)
643 switch (TREE_CODE (type
))
647 case QUAL_UNION_TYPE
:
648 for (fld
= TYPE_FIELDS (type
); fld
; fld
= DECL_CHAIN (fld
))
649 if (TREE_CODE (fld
) == FIELD_DECL
)
651 tree ft
= TREE_TYPE (fld
);
653 if (TREE_THIS_VOLATILE (fld
)
654 || !DECL_FIELD_OFFSET (fld
) || !DECL_SIZE (fld
)
655 || !host_integerp (DECL_FIELD_OFFSET (fld
), 1)
656 || !host_integerp (DECL_SIZE (fld
), 1))
659 if (AGGREGATE_TYPE_P (ft
)
660 && type_internals_preclude_sra_p (ft
))
667 et
= TREE_TYPE (type
);
669 if (AGGREGATE_TYPE_P (et
))
670 return type_internals_preclude_sra_p (et
);
679 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
680 base variable if it is. Return T if it is not an SSA_NAME. */
683 get_ssa_base_param (tree t
)
685 if (TREE_CODE (t
) == SSA_NAME
)
687 if (SSA_NAME_IS_DEFAULT_DEF (t
))
688 return SSA_NAME_VAR (t
);
695 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
696 belongs to, unless the BB has already been marked as a potentially
700 mark_parm_dereference (tree base
, HOST_WIDE_INT dist
, gimple stmt
)
702 basic_block bb
= gimple_bb (stmt
);
703 int idx
, parm_index
= 0;
706 if (bitmap_bit_p (final_bbs
, bb
->index
))
709 for (parm
= DECL_ARGUMENTS (current_function_decl
);
710 parm
&& parm
!= base
;
711 parm
= DECL_CHAIN (parm
))
714 gcc_assert (parm_index
< func_param_count
);
716 idx
= bb
->index
* func_param_count
+ parm_index
;
717 if (bb_dereferences
[idx
] < dist
)
718 bb_dereferences
[idx
] = dist
;
721 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
722 the three fields. Also add it to the vector of accesses corresponding to
723 the base. Finally, return the new access. */
725 static struct access
*
726 create_access_1 (tree base
, HOST_WIDE_INT offset
, HOST_WIDE_INT size
)
728 VEC (access_p
, heap
) *vec
;
729 struct access
*access
;
732 access
= (struct access
*) pool_alloc (access_pool
);
733 memset (access
, 0, sizeof (struct access
));
735 access
->offset
= offset
;
738 slot
= pointer_map_contains (base_access_vec
, base
);
740 vec
= (VEC (access_p
, heap
) *) *slot
;
742 vec
= VEC_alloc (access_p
, heap
, 32);
744 VEC_safe_push (access_p
, heap
, vec
, access
);
746 *((struct VEC (access_p
,heap
) **)
747 pointer_map_insert (base_access_vec
, base
)) = vec
;
752 /* Create and insert access for EXPR. Return created access, or NULL if it is
755 static struct access
*
756 create_access (tree expr
, gimple stmt
, bool write
)
758 struct access
*access
;
759 HOST_WIDE_INT offset
, size
, max_size
;
761 bool ptr
, unscalarizable_region
= false;
763 base
= get_ref_base_and_extent (expr
, &offset
, &size
, &max_size
);
765 if (sra_mode
== SRA_MODE_EARLY_IPA
766 && TREE_CODE (base
) == MEM_REF
)
768 base
= get_ssa_base_param (TREE_OPERAND (base
, 0));
776 if (!DECL_P (base
) || !bitmap_bit_p (candidate_bitmap
, DECL_UID (base
)))
779 if (sra_mode
== SRA_MODE_EARLY_IPA
)
781 if (size
< 0 || size
!= max_size
)
783 disqualify_candidate (base
, "Encountered a variable sized access.");
786 if (TREE_CODE (expr
) == COMPONENT_REF
787 && DECL_BIT_FIELD (TREE_OPERAND (expr
, 1)))
789 disqualify_candidate (base
, "Encountered a bit-field access.");
792 gcc_checking_assert ((offset
% BITS_PER_UNIT
) == 0);
795 mark_parm_dereference (base
, offset
+ size
, stmt
);
799 if (size
!= max_size
)
802 unscalarizable_region
= true;
806 disqualify_candidate (base
, "Encountered an unconstrained access.");
811 access
= create_access_1 (base
, offset
, size
);
813 access
->type
= TREE_TYPE (expr
);
814 access
->write
= write
;
815 access
->grp_unscalarizable_region
= unscalarizable_region
;
822 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
823 register types or (recursively) records with only these two kinds of fields.
824 It also returns false if any of these records contains a bit-field. */
827 type_consists_of_records_p (tree type
)
831 if (TREE_CODE (type
) != RECORD_TYPE
)
834 for (fld
= TYPE_FIELDS (type
); fld
; fld
= DECL_CHAIN (fld
))
835 if (TREE_CODE (fld
) == FIELD_DECL
)
837 tree ft
= TREE_TYPE (fld
);
839 if (DECL_BIT_FIELD (fld
))
842 if (!is_gimple_reg_type (ft
)
843 && !type_consists_of_records_p (ft
))
850 /* Create total_scalarization accesses for all scalar type fields in DECL that
851 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
852 must be the top-most VAR_DECL representing the variable, OFFSET must be the
853 offset of DECL within BASE. REF must be the memory reference expression for
857 completely_scalarize_record (tree base
, tree decl
, HOST_WIDE_INT offset
,
860 tree fld
, decl_type
= TREE_TYPE (decl
);
862 for (fld
= TYPE_FIELDS (decl_type
); fld
; fld
= DECL_CHAIN (fld
))
863 if (TREE_CODE (fld
) == FIELD_DECL
)
865 HOST_WIDE_INT pos
= offset
+ int_bit_position (fld
);
866 tree ft
= TREE_TYPE (fld
);
867 tree nref
= build3 (COMPONENT_REF
, TREE_TYPE (fld
), ref
, fld
,
870 if (is_gimple_reg_type (ft
))
872 struct access
*access
;
875 size
= tree_low_cst (DECL_SIZE (fld
), 1);
876 access
= create_access_1 (base
, pos
, size
);
879 access
->total_scalarization
= 1;
880 /* Accesses for intraprocedural SRA can have their stmt NULL. */
883 completely_scalarize_record (base
, fld
, pos
, nref
);
888 /* Search the given tree for a declaration by skipping handled components and
889 exclude it from the candidates. */
892 disqualify_base_of_expr (tree t
, const char *reason
)
894 t
= get_base_address (t
);
895 if (sra_mode
== SRA_MODE_EARLY_IPA
896 && TREE_CODE (t
) == MEM_REF
)
897 t
= get_ssa_base_param (TREE_OPERAND (t
, 0));
900 disqualify_candidate (t
, reason
);
903 /* Scan expression EXPR and create access structures for all accesses to
904 candidates for scalarization. Return the created access or NULL if none is
907 static struct access
*
908 build_access_from_expr_1 (tree expr
, gimple stmt
, bool write
)
910 struct access
*ret
= NULL
;
913 if (TREE_CODE (expr
) == BIT_FIELD_REF
914 || TREE_CODE (expr
) == IMAGPART_EXPR
915 || TREE_CODE (expr
) == REALPART_EXPR
)
917 expr
= TREE_OPERAND (expr
, 0);
923 /* We need to dive through V_C_Es in order to get the size of its parameter
924 and not the result type. Ada produces such statements. We are also
925 capable of handling the topmost V_C_E but not any of those buried in other
926 handled components. */
927 if (TREE_CODE (expr
) == VIEW_CONVERT_EXPR
)
928 expr
= TREE_OPERAND (expr
, 0);
930 if (contains_view_convert_expr_p (expr
))
932 disqualify_base_of_expr (expr
, "V_C_E under a different handled "
937 switch (TREE_CODE (expr
))
940 if (TREE_CODE (TREE_OPERAND (expr
, 0)) != ADDR_EXPR
941 && sra_mode
!= SRA_MODE_EARLY_IPA
)
949 case ARRAY_RANGE_REF
:
950 ret
= create_access (expr
, stmt
, write
);
957 if (write
&& partial_ref
&& ret
)
958 ret
->grp_partial_lhs
= 1;
963 /* Scan expression EXPR and create access structures for all accesses to
964 candidates for scalarization. Return true if any access has been inserted.
965 STMT must be the statement from which the expression is taken, WRITE must be
966 true if the expression is a store and false otherwise. */
969 build_access_from_expr (tree expr
, gimple stmt
, bool write
)
971 struct access
*access
;
973 access
= build_access_from_expr_1 (expr
, stmt
, write
);
976 /* This means the aggregate is accesses as a whole in a way other than an
977 assign statement and thus cannot be removed even if we had a scalar
978 replacement for everything. */
979 if (cannot_scalarize_away_bitmap
)
980 bitmap_set_bit (cannot_scalarize_away_bitmap
, DECL_UID (access
->base
));
986 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
987 modes in which it matters, return true iff they have been disqualified. RHS
988 may be NULL, in that case ignore it. If we scalarize an aggregate in
989 intra-SRA we may need to add statements after each statement. This is not
990 possible if a statement unconditionally has to end the basic block. */
992 disqualify_ops_if_throwing_stmt (gimple stmt
, tree lhs
, tree rhs
)
994 if ((sra_mode
== SRA_MODE_EARLY_INTRA
|| sra_mode
== SRA_MODE_INTRA
)
995 && (stmt_can_throw_internal (stmt
) || stmt_ends_bb_p (stmt
)))
997 disqualify_base_of_expr (lhs
, "LHS of a throwing stmt.");
999 disqualify_base_of_expr (rhs
, "RHS of a throwing stmt.");
1005 /* Scan expressions occuring in STMT, create access structures for all accesses
1006 to candidates for scalarization and remove those candidates which occur in
1007 statements or expressions that prevent them from being split apart. Return
1008 true if any access has been inserted. */
1011 build_accesses_from_assign (gimple stmt
)
1014 struct access
*lacc
, *racc
;
1016 if (!gimple_assign_single_p (stmt
))
1019 lhs
= gimple_assign_lhs (stmt
);
1020 rhs
= gimple_assign_rhs1 (stmt
);
1022 if (disqualify_ops_if_throwing_stmt (stmt
, lhs
, rhs
))
1025 racc
= build_access_from_expr_1 (rhs
, stmt
, false);
1026 lacc
= build_access_from_expr_1 (lhs
, stmt
, true);
1029 lacc
->grp_assignment_write
= 1;
1033 racc
->grp_assignment_read
= 1;
1034 if (should_scalarize_away_bitmap
&& !gimple_has_volatile_ops (stmt
)
1035 && !is_gimple_reg_type (racc
->type
))
1036 bitmap_set_bit (should_scalarize_away_bitmap
, DECL_UID (racc
->base
));
1040 && (sra_mode
== SRA_MODE_EARLY_INTRA
|| sra_mode
== SRA_MODE_INTRA
)
1041 && !lacc
->grp_unscalarizable_region
1042 && !racc
->grp_unscalarizable_region
1043 && AGGREGATE_TYPE_P (TREE_TYPE (lhs
))
1044 /* FIXME: Turn the following line into an assert after PR 40058 is
1046 && lacc
->size
== racc
->size
1047 && useless_type_conversion_p (lacc
->type
, racc
->type
))
1049 struct assign_link
*link
;
1051 link
= (struct assign_link
*) pool_alloc (link_pool
);
1052 memset (link
, 0, sizeof (struct assign_link
));
1057 add_link_to_rhs (racc
, link
);
1060 return lacc
|| racc
;
1063 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1064 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1067 asm_visit_addr (gimple stmt ATTRIBUTE_UNUSED
, tree op
,
1068 void *data ATTRIBUTE_UNUSED
)
1070 op
= get_base_address (op
);
1073 disqualify_candidate (op
, "Non-scalarizable GIMPLE_ASM operand.");
1078 /* Return true iff callsite CALL has at least as many actual arguments as there
1079 are formal parameters of the function currently processed by IPA-SRA. */
1082 callsite_has_enough_arguments_p (gimple call
)
1084 return gimple_call_num_args (call
) >= (unsigned) func_param_count
;
1087 /* Scan function and look for interesting expressions and create access
1088 structures for them. Return true iff any access is created. */
1091 scan_function (void)
1098 gimple_stmt_iterator gsi
;
1099 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1101 gimple stmt
= gsi_stmt (gsi
);
1105 if (final_bbs
&& stmt_can_throw_external (stmt
))
1106 bitmap_set_bit (final_bbs
, bb
->index
);
1107 switch (gimple_code (stmt
))
1110 t
= gimple_return_retval (stmt
);
1112 ret
|= build_access_from_expr (t
, stmt
, false);
1114 bitmap_set_bit (final_bbs
, bb
->index
);
1118 ret
|= build_accesses_from_assign (stmt
);
1122 for (i
= 0; i
< gimple_call_num_args (stmt
); i
++)
1123 ret
|= build_access_from_expr (gimple_call_arg (stmt
, i
),
1126 if (sra_mode
== SRA_MODE_EARLY_IPA
)
1128 tree dest
= gimple_call_fndecl (stmt
);
1129 int flags
= gimple_call_flags (stmt
);
1133 if (DECL_BUILT_IN_CLASS (dest
) == BUILT_IN_NORMAL
1134 && DECL_FUNCTION_CODE (dest
) == BUILT_IN_APPLY_ARGS
)
1135 encountered_apply_args
= true;
1136 if (cgraph_get_node (dest
)
1137 == cgraph_get_node (current_function_decl
))
1139 encountered_recursive_call
= true;
1140 if (!callsite_has_enough_arguments_p (stmt
))
1141 encountered_unchangable_recursive_call
= true;
1146 && (flags
& (ECF_CONST
| ECF_PURE
)) == 0)
1147 bitmap_set_bit (final_bbs
, bb
->index
);
1150 t
= gimple_call_lhs (stmt
);
1151 if (t
&& !disqualify_ops_if_throwing_stmt (stmt
, t
, NULL
))
1152 ret
|= build_access_from_expr (t
, stmt
, true);
1156 walk_stmt_load_store_addr_ops (stmt
, NULL
, NULL
, NULL
,
1159 bitmap_set_bit (final_bbs
, bb
->index
);
1161 for (i
= 0; i
< gimple_asm_ninputs (stmt
); i
++)
1163 t
= TREE_VALUE (gimple_asm_input_op (stmt
, i
));
1164 ret
|= build_access_from_expr (t
, stmt
, false);
1166 for (i
= 0; i
< gimple_asm_noutputs (stmt
); i
++)
1168 t
= TREE_VALUE (gimple_asm_output_op (stmt
, i
));
1169 ret
|= build_access_from_expr (t
, stmt
, true);
1182 /* Helper of QSORT function. There are pointers to accesses in the array. An
1183 access is considered smaller than another if it has smaller offset or if the
1184 offsets are the same but is size is bigger. */
1187 compare_access_positions (const void *a
, const void *b
)
1189 const access_p
*fp1
= (const access_p
*) a
;
1190 const access_p
*fp2
= (const access_p
*) b
;
1191 const access_p f1
= *fp1
;
1192 const access_p f2
= *fp2
;
1194 if (f1
->offset
!= f2
->offset
)
1195 return f1
->offset
< f2
->offset
? -1 : 1;
1197 if (f1
->size
== f2
->size
)
1199 if (f1
->type
== f2
->type
)
1201 /* Put any non-aggregate type before any aggregate type. */
1202 else if (!is_gimple_reg_type (f1
->type
)
1203 && is_gimple_reg_type (f2
->type
))
1205 else if (is_gimple_reg_type (f1
->type
)
1206 && !is_gimple_reg_type (f2
->type
))
1208 /* Put any complex or vector type before any other scalar type. */
1209 else if (TREE_CODE (f1
->type
) != COMPLEX_TYPE
1210 && TREE_CODE (f1
->type
) != VECTOR_TYPE
1211 && (TREE_CODE (f2
->type
) == COMPLEX_TYPE
1212 || TREE_CODE (f2
->type
) == VECTOR_TYPE
))
1214 else if ((TREE_CODE (f1
->type
) == COMPLEX_TYPE
1215 || TREE_CODE (f1
->type
) == VECTOR_TYPE
)
1216 && TREE_CODE (f2
->type
) != COMPLEX_TYPE
1217 && TREE_CODE (f2
->type
) != VECTOR_TYPE
)
1219 /* Put the integral type with the bigger precision first. */
1220 else if (INTEGRAL_TYPE_P (f1
->type
)
1221 && INTEGRAL_TYPE_P (f2
->type
))
1222 return TYPE_PRECISION (f2
->type
) - TYPE_PRECISION (f1
->type
);
1223 /* Put any integral type with non-full precision last. */
1224 else if (INTEGRAL_TYPE_P (f1
->type
)
1225 && (TREE_INT_CST_LOW (TYPE_SIZE (f1
->type
))
1226 != TYPE_PRECISION (f1
->type
)))
1228 else if (INTEGRAL_TYPE_P (f2
->type
)
1229 && (TREE_INT_CST_LOW (TYPE_SIZE (f2
->type
))
1230 != TYPE_PRECISION (f2
->type
)))
1232 /* Stabilize the sort. */
1233 return TYPE_UID (f1
->type
) - TYPE_UID (f2
->type
);
1236 /* We want the bigger accesses first, thus the opposite operator in the next
1238 return f1
->size
> f2
->size
? -1 : 1;
1242 /* Append a name of the declaration to the name obstack. A helper function for
1246 make_fancy_decl_name (tree decl
)
1250 tree name
= DECL_NAME (decl
);
1252 obstack_grow (&name_obstack
, IDENTIFIER_POINTER (name
),
1253 IDENTIFIER_LENGTH (name
));
1256 sprintf (buffer
, "D%u", DECL_UID (decl
));
1257 obstack_grow (&name_obstack
, buffer
, strlen (buffer
));
1261 /* Helper for make_fancy_name. */
1264 make_fancy_name_1 (tree expr
)
1271 make_fancy_decl_name (expr
);
1275 switch (TREE_CODE (expr
))
1278 make_fancy_name_1 (TREE_OPERAND (expr
, 0));
1279 obstack_1grow (&name_obstack
, '$');
1280 make_fancy_decl_name (TREE_OPERAND (expr
, 1));
1284 make_fancy_name_1 (TREE_OPERAND (expr
, 0));
1285 obstack_1grow (&name_obstack
, '$');
1286 /* Arrays with only one element may not have a constant as their
1288 index
= TREE_OPERAND (expr
, 1);
1289 if (TREE_CODE (index
) != INTEGER_CST
)
1291 sprintf (buffer
, HOST_WIDE_INT_PRINT_DEC
, TREE_INT_CST_LOW (index
));
1292 obstack_grow (&name_obstack
, buffer
, strlen (buffer
));
1296 make_fancy_name_1 (TREE_OPERAND (expr
, 0));
1300 make_fancy_name_1 (TREE_OPERAND (expr
, 0));
1301 if (!integer_zerop (TREE_OPERAND (expr
, 1)))
1303 obstack_1grow (&name_obstack
, '$');
1304 sprintf (buffer
, HOST_WIDE_INT_PRINT_DEC
,
1305 TREE_INT_CST_LOW (TREE_OPERAND (expr
, 1)));
1306 obstack_grow (&name_obstack
, buffer
, strlen (buffer
));
1313 gcc_unreachable (); /* we treat these as scalars. */
1320 /* Create a human readable name for replacement variable of ACCESS. */
1323 make_fancy_name (tree expr
)
1325 make_fancy_name_1 (expr
);
1326 obstack_1grow (&name_obstack
, '\0');
1327 return XOBFINISH (&name_obstack
, char *);
1330 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1331 EXP_TYPE at the given OFFSET. If BASE is something for which
1332 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1333 to insert new statements either before or below the current one as specified
1334 by INSERT_AFTER. This function is not capable of handling bitfields. */
1337 build_ref_for_offset (location_t loc
, tree base
, HOST_WIDE_INT offset
,
1338 tree exp_type
, gimple_stmt_iterator
*gsi
,
1341 tree prev_base
= base
;
1343 HOST_WIDE_INT base_offset
;
1345 gcc_checking_assert (offset
% BITS_PER_UNIT
== 0);
1347 base
= get_addr_base_and_unit_offset (base
, &base_offset
);
1349 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1350 offset such as array[var_index]. */
1356 gcc_checking_assert (gsi
);
1357 tmp
= create_tmp_reg (build_pointer_type (TREE_TYPE (prev_base
)), NULL
);
1358 add_referenced_var (tmp
);
1359 tmp
= make_ssa_name (tmp
, NULL
);
1360 addr
= build_fold_addr_expr (unshare_expr (prev_base
));
1361 stmt
= gimple_build_assign (tmp
, addr
);
1362 gimple_set_location (stmt
, loc
);
1363 SSA_NAME_DEF_STMT (tmp
) = stmt
;
1365 gsi_insert_after (gsi
, stmt
, GSI_NEW_STMT
);
1367 gsi_insert_before (gsi
, stmt
, GSI_SAME_STMT
);
1370 off
= build_int_cst (reference_alias_ptr_type (prev_base
),
1371 offset
/ BITS_PER_UNIT
);
1374 else if (TREE_CODE (base
) == MEM_REF
)
1376 off
= build_int_cst (TREE_TYPE (TREE_OPERAND (base
, 1)),
1377 base_offset
+ offset
/ BITS_PER_UNIT
);
1378 off
= int_const_binop (PLUS_EXPR
, TREE_OPERAND (base
, 1), off
, 0);
1379 base
= unshare_expr (TREE_OPERAND (base
, 0));
1383 off
= build_int_cst (reference_alias_ptr_type (base
),
1384 base_offset
+ offset
/ BITS_PER_UNIT
);
1385 base
= build_fold_addr_expr (unshare_expr (base
));
1388 return fold_build2_loc (loc
, MEM_REF
, exp_type
, base
, off
);
1391 /* Construct a memory reference to a part of an aggregate BASE at the given
1392 OFFSET and of the same type as MODEL. In case this is a reference to a
1393 bit-field, the function will replicate the last component_ref of model's
1394 expr to access it. GSI and INSERT_AFTER have the same meaning as in
1395 build_ref_for_offset. */
1398 build_ref_for_model (location_t loc
, tree base
, HOST_WIDE_INT offset
,
1399 struct access
*model
, gimple_stmt_iterator
*gsi
,
1402 if (TREE_CODE (model
->expr
) == COMPONENT_REF
1403 && DECL_BIT_FIELD (TREE_OPERAND (model
->expr
, 1)))
1405 /* This access represents a bit-field. */
1408 offset
-= int_bit_position (TREE_OPERAND (model
->expr
, 1));
1409 exp_type
= TREE_TYPE (TREE_OPERAND (model
->expr
, 0));
1410 t
= build_ref_for_offset (loc
, base
, offset
, exp_type
, gsi
, insert_after
);
1411 return fold_build3_loc (loc
, COMPONENT_REF
, model
->type
, t
,
1412 TREE_OPERAND (model
->expr
, 1), NULL_TREE
);
1415 return build_ref_for_offset (loc
, base
, offset
, model
->type
,
1419 /* Construct a memory reference consisting of component_refs and array_refs to
1420 a part of an aggregate *RES (which is of type TYPE). The requested part
1421 should have type EXP_TYPE at be the given OFFSET. This function might not
1422 succeed, it returns true when it does and only then *RES points to something
1423 meaningful. This function should be used only to build expressions that we
1424 might need to present to user (e.g. in warnings). In all other situations,
1425 build_ref_for_model or build_ref_for_offset should be used instead. */
1428 build_user_friendly_ref_for_offset (tree
*res
, tree type
, HOST_WIDE_INT offset
,
1434 tree tr_size
, index
, minidx
;
1435 HOST_WIDE_INT el_size
;
1437 if (offset
== 0 && exp_type
1438 && types_compatible_p (exp_type
, type
))
1441 switch (TREE_CODE (type
))
1444 case QUAL_UNION_TYPE
:
1446 for (fld
= TYPE_FIELDS (type
); fld
; fld
= DECL_CHAIN (fld
))
1448 HOST_WIDE_INT pos
, size
;
1449 tree expr
, *expr_ptr
;
1451 if (TREE_CODE (fld
) != FIELD_DECL
)
1454 pos
= int_bit_position (fld
);
1455 gcc_assert (TREE_CODE (type
) == RECORD_TYPE
|| pos
== 0);
1456 tr_size
= DECL_SIZE (fld
);
1457 if (!tr_size
|| !host_integerp (tr_size
, 1))
1459 size
= tree_low_cst (tr_size
, 1);
1465 else if (pos
> offset
|| (pos
+ size
) <= offset
)
1468 expr
= build3 (COMPONENT_REF
, TREE_TYPE (fld
), *res
, fld
,
1471 if (build_user_friendly_ref_for_offset (expr_ptr
, TREE_TYPE (fld
),
1472 offset
- pos
, exp_type
))
1481 tr_size
= TYPE_SIZE (TREE_TYPE (type
));
1482 if (!tr_size
|| !host_integerp (tr_size
, 1))
1484 el_size
= tree_low_cst (tr_size
, 1);
1486 minidx
= TYPE_MIN_VALUE (TYPE_DOMAIN (type
));
1487 if (TREE_CODE (minidx
) != INTEGER_CST
|| el_size
== 0)
1489 index
= build_int_cst (TYPE_DOMAIN (type
), offset
/ el_size
);
1490 if (!integer_zerop (minidx
))
1491 index
= int_const_binop (PLUS_EXPR
, index
, minidx
, 0);
1492 *res
= build4 (ARRAY_REF
, TREE_TYPE (type
), *res
, index
,
1493 NULL_TREE
, NULL_TREE
);
1494 offset
= offset
% el_size
;
1495 type
= TREE_TYPE (type
);
1510 /* Return true iff TYPE is stdarg va_list type. */
1513 is_va_list_type (tree type
)
1515 return TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (va_list_type_node
);
1518 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1519 those with type which is suitable for scalarization. */
1522 find_var_candidates (void)
1525 referenced_var_iterator rvi
;
1528 FOR_EACH_REFERENCED_VAR (var
, rvi
)
1530 if (TREE_CODE (var
) != VAR_DECL
&& TREE_CODE (var
) != PARM_DECL
)
1532 type
= TREE_TYPE (var
);
1534 if (!AGGREGATE_TYPE_P (type
)
1535 || needs_to_live_in_memory (var
)
1536 || TREE_THIS_VOLATILE (var
)
1537 || !COMPLETE_TYPE_P (type
)
1538 || !host_integerp (TYPE_SIZE (type
), 1)
1539 || tree_low_cst (TYPE_SIZE (type
), 1) == 0
1540 || type_internals_preclude_sra_p (type
)
1541 /* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1542 we also want to schedule it rather late. Thus we ignore it in
1544 || (sra_mode
== SRA_MODE_EARLY_INTRA
1545 && is_va_list_type (type
)))
1548 bitmap_set_bit (candidate_bitmap
, DECL_UID (var
));
1550 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1552 fprintf (dump_file
, "Candidate (%d): ", DECL_UID (var
));
1553 print_generic_expr (dump_file
, var
, 0);
1554 fprintf (dump_file
, "\n");
1562 /* Sort all accesses for the given variable, check for partial overlaps and
1563 return NULL if there are any. If there are none, pick a representative for
1564 each combination of offset and size and create a linked list out of them.
1565 Return the pointer to the first representative and make sure it is the first
1566 one in the vector of accesses. */
1568 static struct access
*
1569 sort_and_splice_var_accesses (tree var
)
1571 int i
, j
, access_count
;
1572 struct access
*res
, **prev_acc_ptr
= &res
;
1573 VEC (access_p
, heap
) *access_vec
;
1575 HOST_WIDE_INT low
= -1, high
= 0;
1577 access_vec
= get_base_access_vector (var
);
1580 access_count
= VEC_length (access_p
, access_vec
);
1582 /* Sort by <OFFSET, SIZE>. */
1583 VEC_qsort (access_p
, access_vec
, compare_access_positions
);
1586 while (i
< access_count
)
1588 struct access
*access
= VEC_index (access_p
, access_vec
, i
);
1589 bool grp_write
= access
->write
;
1590 bool grp_read
= !access
->write
;
1591 bool grp_assignment_read
= access
->grp_assignment_read
;
1592 bool grp_assignment_write
= access
->grp_assignment_write
;
1593 bool multiple_reads
= false;
1594 bool total_scalarization
= access
->total_scalarization
;
1595 bool grp_partial_lhs
= access
->grp_partial_lhs
;
1596 bool first_scalar
= is_gimple_reg_type (access
->type
);
1597 bool unscalarizable_region
= access
->grp_unscalarizable_region
;
1599 if (first
|| access
->offset
>= high
)
1602 low
= access
->offset
;
1603 high
= access
->offset
+ access
->size
;
1605 else if (access
->offset
> low
&& access
->offset
+ access
->size
> high
)
1608 gcc_assert (access
->offset
>= low
1609 && access
->offset
+ access
->size
<= high
);
1612 while (j
< access_count
)
1614 struct access
*ac2
= VEC_index (access_p
, access_vec
, j
);
1615 if (ac2
->offset
!= access
->offset
|| ac2
->size
!= access
->size
)
1622 multiple_reads
= true;
1626 grp_assignment_read
|= ac2
->grp_assignment_read
;
1627 grp_assignment_write
|= ac2
->grp_assignment_write
;
1628 grp_partial_lhs
|= ac2
->grp_partial_lhs
;
1629 unscalarizable_region
|= ac2
->grp_unscalarizable_region
;
1630 total_scalarization
|= ac2
->total_scalarization
;
1631 relink_to_new_repr (access
, ac2
);
1633 /* If there are both aggregate-type and scalar-type accesses with
1634 this combination of size and offset, the comparison function
1635 should have put the scalars first. */
1636 gcc_assert (first_scalar
|| !is_gimple_reg_type (ac2
->type
));
1637 ac2
->group_representative
= access
;
1643 access
->group_representative
= access
;
1644 access
->grp_write
= grp_write
;
1645 access
->grp_read
= grp_read
;
1646 access
->grp_assignment_read
= grp_assignment_read
;
1647 access
->grp_assignment_write
= grp_assignment_write
;
1648 access
->grp_hint
= multiple_reads
|| total_scalarization
;
1649 access
->grp_partial_lhs
= grp_partial_lhs
;
1650 access
->grp_unscalarizable_region
= unscalarizable_region
;
1651 if (access
->first_link
)
1652 add_access_to_work_queue (access
);
1654 *prev_acc_ptr
= access
;
1655 prev_acc_ptr
= &access
->next_grp
;
1658 gcc_assert (res
== VEC_index (access_p
, access_vec
, 0));
1662 /* Create a variable for the given ACCESS which determines the type, name and a
1663 few other properties. Return the variable declaration and store it also to
1664 ACCESS->replacement. */
1667 create_access_replacement (struct access
*access
, bool rename
)
1671 repl
= create_tmp_var (access
->type
, "SR");
1673 add_referenced_var (repl
);
1675 mark_sym_for_renaming (repl
);
1677 if (!access
->grp_partial_lhs
1678 && (TREE_CODE (access
->type
) == COMPLEX_TYPE
1679 || TREE_CODE (access
->type
) == VECTOR_TYPE
))
1680 DECL_GIMPLE_REG_P (repl
) = 1;
1682 DECL_SOURCE_LOCATION (repl
) = DECL_SOURCE_LOCATION (access
->base
);
1683 DECL_ARTIFICIAL (repl
) = 1;
1684 DECL_IGNORED_P (repl
) = DECL_IGNORED_P (access
->base
);
1686 if (DECL_NAME (access
->base
)
1687 && !DECL_IGNORED_P (access
->base
)
1688 && !DECL_ARTIFICIAL (access
->base
))
1690 char *pretty_name
= make_fancy_name (access
->expr
);
1691 tree debug_expr
= unshare_expr (access
->expr
), d
;
1693 DECL_NAME (repl
) = get_identifier (pretty_name
);
1694 obstack_free (&name_obstack
, pretty_name
);
1696 /* Get rid of any SSA_NAMEs embedded in debug_expr,
1697 as DECL_DEBUG_EXPR isn't considered when looking for still
1698 used SSA_NAMEs and thus they could be freed. All debug info
1699 generation cares is whether something is constant or variable
1700 and that get_ref_base_and_extent works properly on the
1702 for (d
= debug_expr
; handled_component_p (d
); d
= TREE_OPERAND (d
, 0))
1703 switch (TREE_CODE (d
))
1706 case ARRAY_RANGE_REF
:
1707 if (TREE_OPERAND (d
, 1)
1708 && TREE_CODE (TREE_OPERAND (d
, 1)) == SSA_NAME
)
1709 TREE_OPERAND (d
, 1) = SSA_NAME_VAR (TREE_OPERAND (d
, 1));
1710 if (TREE_OPERAND (d
, 3)
1711 && TREE_CODE (TREE_OPERAND (d
, 3)) == SSA_NAME
)
1712 TREE_OPERAND (d
, 3) = SSA_NAME_VAR (TREE_OPERAND (d
, 3));
1715 if (TREE_OPERAND (d
, 2)
1716 && TREE_CODE (TREE_OPERAND (d
, 2)) == SSA_NAME
)
1717 TREE_OPERAND (d
, 2) = SSA_NAME_VAR (TREE_OPERAND (d
, 2));
1722 SET_DECL_DEBUG_EXPR (repl
, debug_expr
);
1723 DECL_DEBUG_EXPR_IS_FROM (repl
) = 1;
1724 if (access
->grp_no_warning
)
1725 TREE_NO_WARNING (repl
) = 1;
1727 TREE_NO_WARNING (repl
) = TREE_NO_WARNING (access
->base
);
1730 TREE_NO_WARNING (repl
) = 1;
1734 fprintf (dump_file
, "Created a replacement for ");
1735 print_generic_expr (dump_file
, access
->base
, 0);
1736 fprintf (dump_file
, " offset: %u, size: %u: ",
1737 (unsigned) access
->offset
, (unsigned) access
->size
);
1738 print_generic_expr (dump_file
, repl
, 0);
1739 fprintf (dump_file
, "\n");
1741 sra_stats
.replacements
++;
1746 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
1749 get_access_replacement (struct access
*access
)
1751 gcc_assert (access
->grp_to_be_replaced
);
1753 if (!access
->replacement_decl
)
1754 access
->replacement_decl
= create_access_replacement (access
, true);
1755 return access
->replacement_decl
;
1758 /* Return ACCESS scalar replacement, create it if it does not exist yet but do
1759 not mark it for renaming. */
1762 get_unrenamed_access_replacement (struct access
*access
)
1764 gcc_assert (!access
->grp_to_be_replaced
);
1766 if (!access
->replacement_decl
)
1767 access
->replacement_decl
= create_access_replacement (access
, false);
1768 return access
->replacement_decl
;
1772 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
1773 linked list along the way. Stop when *ACCESS is NULL or the access pointed
1774 to it is not "within" the root. Return false iff some accesses partially
1778 build_access_subtree (struct access
**access
)
1780 struct access
*root
= *access
, *last_child
= NULL
;
1781 HOST_WIDE_INT limit
= root
->offset
+ root
->size
;
1783 *access
= (*access
)->next_grp
;
1784 while (*access
&& (*access
)->offset
+ (*access
)->size
<= limit
)
1787 root
->first_child
= *access
;
1789 last_child
->next_sibling
= *access
;
1790 last_child
= *access
;
1792 if (!build_access_subtree (access
))
1796 if (*access
&& (*access
)->offset
< limit
)
1802 /* Build a tree of access representatives, ACCESS is the pointer to the first
1803 one, others are linked in a list by the next_grp field. Return false iff
1804 some accesses partially overlap. */
1807 build_access_trees (struct access
*access
)
1811 struct access
*root
= access
;
1813 if (!build_access_subtree (&access
))
1815 root
->next_grp
= access
;
1820 /* Return true if expr contains some ARRAY_REFs into a variable bounded
1824 expr_with_var_bounded_array_refs_p (tree expr
)
1826 while (handled_component_p (expr
))
1828 if (TREE_CODE (expr
) == ARRAY_REF
1829 && !host_integerp (array_ref_low_bound (expr
), 0))
1831 expr
= TREE_OPERAND (expr
, 0);
1836 enum mark_rw_status
{ SRA_MRRW_NOTHING
, SRA_MRRW_DIRECT
, SRA_MRRW_ASSIGN
};
1838 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
1839 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
1840 sorts of access flags appropriately along the way, notably always set
1841 grp_read and grp_assign_read according to MARK_READ and grp_write when
1844 Creating a replacement for a scalar access is considered beneficial if its
1845 grp_hint is set (this means we are either attempting total scalarization or
1846 there is more than one direct read access) or according to the following
1849 Access written to individually (once or more times)
1851 | Parent written to in an assignment statement
1853 | | Access read individually _once_
1855 | | | Parent read in an assignment statement
1857 | | | | Scalarize Comment
1858 -----------------------------------------------------------------------------
1859 0 0 0 0 No access for the scalar
1860 0 0 0 1 No access for the scalar
1861 0 0 1 0 No Single read - won't help
1862 0 0 1 1 No The same case
1863 0 1 0 0 No access for the scalar
1864 0 1 0 1 No access for the scalar
1865 0 1 1 0 Yes s = *g; return s.i;
1866 0 1 1 1 Yes The same case as above
1867 1 0 0 0 No Won't help
1868 1 0 0 1 Yes s.i = 1; *g = s;
1869 1 0 1 0 Yes s.i = 5; g = s.i;
1870 1 0 1 1 Yes The same case as above
1871 1 1 0 0 No Won't help.
1872 1 1 0 1 Yes s.i = 1; *g = s;
1873 1 1 1 0 Yes s = *g; return s.i;
1874 1 1 1 1 Yes Any of the above yeses */
1877 analyze_access_subtree (struct access
*root
, bool allow_replacements
,
1878 enum mark_rw_status mark_read
,
1879 enum mark_rw_status mark_write
)
1881 struct access
*child
;
1882 HOST_WIDE_INT limit
= root
->offset
+ root
->size
;
1883 HOST_WIDE_INT covered_to
= root
->offset
;
1884 bool scalar
= is_gimple_reg_type (root
->type
);
1885 bool hole
= false, sth_created
= false;
1886 bool direct_read
= root
->grp_read
;
1887 bool direct_write
= root
->grp_write
;
1889 if (root
->grp_assignment_read
)
1890 mark_read
= SRA_MRRW_ASSIGN
;
1891 else if (mark_read
== SRA_MRRW_ASSIGN
)
1894 root
->grp_assignment_read
= 1;
1896 else if (mark_read
== SRA_MRRW_DIRECT
)
1898 else if (root
->grp_read
)
1899 mark_read
= SRA_MRRW_DIRECT
;
1901 if (root
->grp_assignment_write
)
1902 mark_write
= SRA_MRRW_ASSIGN
;
1903 else if (mark_write
== SRA_MRRW_ASSIGN
)
1905 root
->grp_write
= 1;
1906 root
->grp_assignment_write
= 1;
1908 else if (mark_write
== SRA_MRRW_DIRECT
)
1909 root
->grp_write
= 1;
1910 else if (root
->grp_write
)
1911 mark_write
= SRA_MRRW_DIRECT
;
1913 if (root
->grp_unscalarizable_region
)
1914 allow_replacements
= false;
1916 if (allow_replacements
&& expr_with_var_bounded_array_refs_p (root
->expr
))
1917 allow_replacements
= false;
1919 for (child
= root
->first_child
; child
; child
= child
->next_sibling
)
1921 if (!hole
&& child
->offset
< covered_to
)
1924 covered_to
+= child
->size
;
1926 sth_created
|= analyze_access_subtree (child
,
1927 allow_replacements
&& !scalar
,
1928 mark_read
, mark_write
);
1930 root
->grp_unscalarized_data
|= child
->grp_unscalarized_data
;
1931 hole
|= !child
->grp_covered
;
1934 if (allow_replacements
&& scalar
&& !root
->first_child
1936 || ((direct_write
|| root
->grp_assignment_write
)
1937 && (direct_read
|| root
->grp_assignment_read
))))
1939 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1941 fprintf (dump_file
, "Marking ");
1942 print_generic_expr (dump_file
, root
->base
, 0);
1943 fprintf (dump_file
, " offset: %u, size: %u: ",
1944 (unsigned) root
->offset
, (unsigned) root
->size
);
1945 fprintf (dump_file
, " to be replaced.\n");
1948 root
->grp_to_be_replaced
= 1;
1952 else if (covered_to
< limit
)
1955 if (sth_created
&& !hole
)
1957 root
->grp_covered
= 1;
1960 if (root
->grp_write
|| TREE_CODE (root
->base
) == PARM_DECL
)
1961 root
->grp_unscalarized_data
= 1; /* not covered and written to */
1967 /* Analyze all access trees linked by next_grp by the means of
1968 analyze_access_subtree. */
1970 analyze_access_trees (struct access
*access
)
1976 if (analyze_access_subtree (access
, true,
1977 SRA_MRRW_NOTHING
, SRA_MRRW_NOTHING
))
1979 access
= access
->next_grp
;
1985 /* Return true iff a potential new child of LACC at offset OFFSET and with size
1986 SIZE would conflict with an already existing one. If exactly such a child
1987 already exists in LACC, store a pointer to it in EXACT_MATCH. */
1990 child_would_conflict_in_lacc (struct access
*lacc
, HOST_WIDE_INT norm_offset
,
1991 HOST_WIDE_INT size
, struct access
**exact_match
)
1993 struct access
*child
;
1995 for (child
= lacc
->first_child
; child
; child
= child
->next_sibling
)
1997 if (child
->offset
== norm_offset
&& child
->size
== size
)
1999 *exact_match
= child
;
2003 if (child
->offset
< norm_offset
+ size
2004 && child
->offset
+ child
->size
> norm_offset
)
2011 /* Create a new child access of PARENT, with all properties just like MODEL
2012 except for its offset and with its grp_write false and grp_read true.
2013 Return the new access or NULL if it cannot be created. Note that this access
2014 is created long after all splicing and sorting, it's not located in any
2015 access vector and is automatically a representative of its group. */
2017 static struct access
*
2018 create_artificial_child_access (struct access
*parent
, struct access
*model
,
2019 HOST_WIDE_INT new_offset
)
2021 struct access
*access
;
2022 struct access
**child
;
2023 tree expr
= parent
->base
;
2025 gcc_assert (!model
->grp_unscalarizable_region
);
2027 access
= (struct access
*) pool_alloc (access_pool
);
2028 memset (access
, 0, sizeof (struct access
));
2029 if (!build_user_friendly_ref_for_offset (&expr
, TREE_TYPE (expr
), new_offset
,
2032 access
->grp_no_warning
= true;
2033 expr
= build_ref_for_model (EXPR_LOCATION (parent
->base
), parent
->base
,
2034 new_offset
, model
, NULL
, false);
2037 access
->base
= parent
->base
;
2038 access
->expr
= expr
;
2039 access
->offset
= new_offset
;
2040 access
->size
= model
->size
;
2041 access
->type
= model
->type
;
2042 access
->grp_write
= true;
2043 access
->grp_read
= false;
2045 child
= &parent
->first_child
;
2046 while (*child
&& (*child
)->offset
< new_offset
)
2047 child
= &(*child
)->next_sibling
;
2049 access
->next_sibling
= *child
;
2056 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2057 true if any new subaccess was created. Additionally, if RACC is a scalar
2058 access but LACC is not, change the type of the latter, if possible. */
2061 propagate_subaccesses_across_link (struct access
*lacc
, struct access
*racc
)
2063 struct access
*rchild
;
2064 HOST_WIDE_INT norm_delta
= lacc
->offset
- racc
->offset
;
2067 if (is_gimple_reg_type (lacc
->type
)
2068 || lacc
->grp_unscalarizable_region
2069 || racc
->grp_unscalarizable_region
)
2072 if (!lacc
->first_child
&& !racc
->first_child
2073 && is_gimple_reg_type (racc
->type
))
2075 tree t
= lacc
->base
;
2077 lacc
->type
= racc
->type
;
2078 if (build_user_friendly_ref_for_offset (&t
, TREE_TYPE (t
), lacc
->offset
,
2083 lacc
->expr
= build_ref_for_model (EXPR_LOCATION (lacc
->base
),
2084 lacc
->base
, lacc
->offset
,
2086 lacc
->grp_no_warning
= true;
2091 for (rchild
= racc
->first_child
; rchild
; rchild
= rchild
->next_sibling
)
2093 struct access
*new_acc
= NULL
;
2094 HOST_WIDE_INT norm_offset
= rchild
->offset
+ norm_delta
;
2096 if (rchild
->grp_unscalarizable_region
)
2099 if (child_would_conflict_in_lacc (lacc
, norm_offset
, rchild
->size
,
2104 rchild
->grp_hint
= 1;
2105 new_acc
->grp_hint
|= new_acc
->grp_read
;
2106 if (rchild
->first_child
)
2107 ret
|= propagate_subaccesses_across_link (new_acc
, rchild
);
2112 rchild
->grp_hint
= 1;
2113 new_acc
= create_artificial_child_access (lacc
, rchild
, norm_offset
);
2117 if (racc
->first_child
)
2118 propagate_subaccesses_across_link (new_acc
, rchild
);
2125 /* Propagate all subaccesses across assignment links. */
2128 propagate_all_subaccesses (void)
2130 while (work_queue_head
)
2132 struct access
*racc
= pop_access_from_work_queue ();
2133 struct assign_link
*link
;
2135 gcc_assert (racc
->first_link
);
2137 for (link
= racc
->first_link
; link
; link
= link
->next
)
2139 struct access
*lacc
= link
->lacc
;
2141 if (!bitmap_bit_p (candidate_bitmap
, DECL_UID (lacc
->base
)))
2143 lacc
= lacc
->group_representative
;
2144 if (propagate_subaccesses_across_link (lacc
, racc
)
2145 && lacc
->first_link
)
2146 add_access_to_work_queue (lacc
);
2151 /* Go through all accesses collected throughout the (intraprocedural) analysis
2152 stage, exclude overlapping ones, identify representatives and build trees
2153 out of them, making decisions about scalarization on the way. Return true
2154 iff there are any to-be-scalarized variables after this stage. */
2157 analyze_all_variable_accesses (void)
2160 bitmap tmp
= BITMAP_ALLOC (NULL
);
2162 unsigned i
, max_total_scalarization_size
;
2164 max_total_scalarization_size
= UNITS_PER_WORD
* BITS_PER_UNIT
2165 * MOVE_RATIO (optimize_function_for_speed_p (cfun
));
2167 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap
, 0, i
, bi
)
2168 if (bitmap_bit_p (should_scalarize_away_bitmap
, i
)
2169 && !bitmap_bit_p (cannot_scalarize_away_bitmap
, i
))
2171 tree var
= referenced_var (i
);
2173 if (TREE_CODE (var
) == VAR_DECL
2174 && ((unsigned) tree_low_cst (TYPE_SIZE (TREE_TYPE (var
)), 1)
2175 <= max_total_scalarization_size
)
2176 && type_consists_of_records_p (TREE_TYPE (var
)))
2178 completely_scalarize_record (var
, var
, 0, var
);
2179 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2181 fprintf (dump_file
, "Will attempt to totally scalarize ");
2182 print_generic_expr (dump_file
, var
, 0);
2183 fprintf (dump_file
, " (UID: %u): \n", DECL_UID (var
));
2188 bitmap_copy (tmp
, candidate_bitmap
);
2189 EXECUTE_IF_SET_IN_BITMAP (tmp
, 0, i
, bi
)
2191 tree var
= referenced_var (i
);
2192 struct access
*access
;
2194 access
= sort_and_splice_var_accesses (var
);
2195 if (!access
|| !build_access_trees (access
))
2196 disqualify_candidate (var
,
2197 "No or inhibitingly overlapping accesses.");
2200 propagate_all_subaccesses ();
2202 bitmap_copy (tmp
, candidate_bitmap
);
2203 EXECUTE_IF_SET_IN_BITMAP (tmp
, 0, i
, bi
)
2205 tree var
= referenced_var (i
);
2206 struct access
*access
= get_first_repr_for_decl (var
);
2208 if (analyze_access_trees (access
))
2211 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2213 fprintf (dump_file
, "\nAccess trees for ");
2214 print_generic_expr (dump_file
, var
, 0);
2215 fprintf (dump_file
, " (UID: %u): \n", DECL_UID (var
));
2216 dump_access_tree (dump_file
, access
);
2217 fprintf (dump_file
, "\n");
2221 disqualify_candidate (var
, "No scalar replacements to be created.");
2228 statistics_counter_event (cfun
, "Scalarized aggregates", res
);
2235 /* Generate statements copying scalar replacements of accesses within a subtree
2236 into or out of AGG. ACCESS, all its children, siblings and their children
2237 are to be processed. AGG is an aggregate type expression (can be a
2238 declaration but does not have to be, it can for example also be a mem_ref or
2239 a series of handled components). TOP_OFFSET is the offset of the processed
2240 subtree which has to be subtracted from offsets of individual accesses to
2241 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2242 replacements in the interval <start_offset, start_offset + chunk_size>,
2243 otherwise copy all. GSI is a statement iterator used to place the new
2244 statements. WRITE should be true when the statements should write from AGG
2245 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2246 statements will be added after the current statement in GSI, they will be
2247 added before the statement otherwise. */
2250 generate_subtree_copies (struct access
*access
, tree agg
,
2251 HOST_WIDE_INT top_offset
,
2252 HOST_WIDE_INT start_offset
, HOST_WIDE_INT chunk_size
,
2253 gimple_stmt_iterator
*gsi
, bool write
,
2254 bool insert_after
, location_t loc
)
2258 if (chunk_size
&& access
->offset
>= start_offset
+ chunk_size
)
2261 if (access
->grp_to_be_replaced
2263 || access
->offset
+ access
->size
> start_offset
))
2265 tree expr
, repl
= get_access_replacement (access
);
2268 expr
= build_ref_for_model (loc
, agg
, access
->offset
- top_offset
,
2269 access
, gsi
, insert_after
);
2273 if (access
->grp_partial_lhs
)
2274 expr
= force_gimple_operand_gsi (gsi
, expr
, true, NULL_TREE
,
2276 insert_after
? GSI_NEW_STMT
2278 stmt
= gimple_build_assign (repl
, expr
);
2282 TREE_NO_WARNING (repl
) = 1;
2283 if (access
->grp_partial_lhs
)
2284 repl
= force_gimple_operand_gsi (gsi
, repl
, true, NULL_TREE
,
2286 insert_after
? GSI_NEW_STMT
2288 stmt
= gimple_build_assign (expr
, repl
);
2290 gimple_set_location (stmt
, loc
);
2293 gsi_insert_after (gsi
, stmt
, GSI_NEW_STMT
);
2295 gsi_insert_before (gsi
, stmt
, GSI_SAME_STMT
);
2297 sra_stats
.subtree_copies
++;
2300 if (access
->first_child
)
2301 generate_subtree_copies (access
->first_child
, agg
, top_offset
,
2302 start_offset
, chunk_size
, gsi
,
2303 write
, insert_after
, loc
);
2305 access
= access
->next_sibling
;
2310 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2311 the root of the subtree to be processed. GSI is the statement iterator used
2312 for inserting statements which are added after the current statement if
2313 INSERT_AFTER is true or before it otherwise. */
2316 init_subtree_with_zero (struct access
*access
, gimple_stmt_iterator
*gsi
,
2317 bool insert_after
, location_t loc
)
2320 struct access
*child
;
2322 if (access
->grp_to_be_replaced
)
2326 stmt
= gimple_build_assign (get_access_replacement (access
),
2327 fold_convert (access
->type
,
2328 integer_zero_node
));
2330 gsi_insert_after (gsi
, stmt
, GSI_NEW_STMT
);
2332 gsi_insert_before (gsi
, stmt
, GSI_SAME_STMT
);
2334 gimple_set_location (stmt
, loc
);
2337 for (child
= access
->first_child
; child
; child
= child
->next_sibling
)
2338 init_subtree_with_zero (child
, gsi
, insert_after
, loc
);
2341 /* Search for an access representative for the given expression EXPR and
2342 return it or NULL if it cannot be found. */
2344 static struct access
*
2345 get_access_for_expr (tree expr
)
2347 HOST_WIDE_INT offset
, size
, max_size
;
2350 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2351 a different size than the size of its argument and we need the latter
2353 if (TREE_CODE (expr
) == VIEW_CONVERT_EXPR
)
2354 expr
= TREE_OPERAND (expr
, 0);
2356 base
= get_ref_base_and_extent (expr
, &offset
, &size
, &max_size
);
2357 if (max_size
== -1 || !DECL_P (base
))
2360 if (!bitmap_bit_p (candidate_bitmap
, DECL_UID (base
)))
2363 return get_var_base_offset_size_access (base
, offset
, max_size
);
2366 /* Replace the expression EXPR with a scalar replacement if there is one and
2367 generate other statements to do type conversion or subtree copying if
2368 necessary. GSI is used to place newly created statements, WRITE is true if
2369 the expression is being written to (it is on a LHS of a statement or output
2370 in an assembly statement). */
2373 sra_modify_expr (tree
*expr
, gimple_stmt_iterator
*gsi
, bool write
)
2376 struct access
*access
;
2379 if (TREE_CODE (*expr
) == BIT_FIELD_REF
)
2382 expr
= &TREE_OPERAND (*expr
, 0);
2387 if (TREE_CODE (*expr
) == REALPART_EXPR
|| TREE_CODE (*expr
) == IMAGPART_EXPR
)
2388 expr
= &TREE_OPERAND (*expr
, 0);
2389 access
= get_access_for_expr (*expr
);
2392 type
= TREE_TYPE (*expr
);
2394 loc
= gimple_location (gsi_stmt (*gsi
));
2395 if (access
->grp_to_be_replaced
)
2397 tree repl
= get_access_replacement (access
);
2398 /* If we replace a non-register typed access simply use the original
2399 access expression to extract the scalar component afterwards.
2400 This happens if scalarizing a function return value or parameter
2401 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2402 gcc.c-torture/compile/20011217-1.c.
2404 We also want to use this when accessing a complex or vector which can
2405 be accessed as a different type too, potentially creating a need for
2406 type conversion (see PR42196) and when scalarized unions are involved
2407 in assembler statements (see PR42398). */
2408 if (!useless_type_conversion_p (type
, access
->type
))
2412 ref
= build_ref_for_model (loc
, access
->base
, access
->offset
, access
,
2419 if (access
->grp_partial_lhs
)
2420 ref
= force_gimple_operand_gsi (gsi
, ref
, true, NULL_TREE
,
2421 false, GSI_NEW_STMT
);
2422 stmt
= gimple_build_assign (repl
, ref
);
2423 gimple_set_location (stmt
, loc
);
2424 gsi_insert_after (gsi
, stmt
, GSI_NEW_STMT
);
2430 if (access
->grp_partial_lhs
)
2431 repl
= force_gimple_operand_gsi (gsi
, repl
, true, NULL_TREE
,
2432 true, GSI_SAME_STMT
);
2433 stmt
= gimple_build_assign (ref
, repl
);
2434 gimple_set_location (stmt
, loc
);
2435 gsi_insert_before (gsi
, stmt
, GSI_SAME_STMT
);
2443 if (access
->first_child
)
2445 HOST_WIDE_INT start_offset
, chunk_size
;
2447 && host_integerp (TREE_OPERAND (bfr
, 1), 1)
2448 && host_integerp (TREE_OPERAND (bfr
, 2), 1))
2450 chunk_size
= tree_low_cst (TREE_OPERAND (bfr
, 1), 1);
2451 start_offset
= access
->offset
2452 + tree_low_cst (TREE_OPERAND (bfr
, 2), 1);
2455 start_offset
= chunk_size
= 0;
2457 generate_subtree_copies (access
->first_child
, access
->base
, 0,
2458 start_offset
, chunk_size
, gsi
, write
, write
,
2464 /* Where scalar replacements of the RHS have been written to when a replacement
2465 of a LHS of an assigments cannot be direclty loaded from a replacement of
2467 enum unscalarized_data_handling
{ SRA_UDH_NONE
, /* Nothing done so far. */
2468 SRA_UDH_RIGHT
, /* Data flushed to the RHS. */
2469 SRA_UDH_LEFT
}; /* Data flushed to the LHS. */
2471 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2472 base aggregate if there are unscalarized data or directly to LHS of the
2473 statement that is pointed to by GSI otherwise. */
2475 static enum unscalarized_data_handling
2476 handle_unscalarized_data_in_subtree (struct access
*top_racc
,
2477 gimple_stmt_iterator
*gsi
)
2479 if (top_racc
->grp_unscalarized_data
)
2481 generate_subtree_copies (top_racc
->first_child
, top_racc
->base
, 0, 0, 0,
2483 gimple_location (gsi_stmt (*gsi
)));
2484 return SRA_UDH_RIGHT
;
2488 tree lhs
= gimple_assign_lhs (gsi_stmt (*gsi
));
2489 generate_subtree_copies (top_racc
->first_child
, lhs
, top_racc
->offset
,
2490 0, 0, gsi
, false, false,
2491 gimple_location (gsi_stmt (*gsi
)));
2492 return SRA_UDH_LEFT
;
2497 /* Try to generate statements to load all sub-replacements in an access subtree
2498 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2499 If that is not possible, refresh the TOP_RACC base aggregate and load the
2500 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2501 copied. NEW_GSI is stmt iterator used for statement insertions after the
2502 original assignment, OLD_GSI is used to insert statements before the
2503 assignment. *REFRESHED keeps the information whether we have needed to
2504 refresh replacements of the LHS and from which side of the assignments this
2508 load_assign_lhs_subreplacements (struct access
*lacc
, struct access
*top_racc
,
2509 HOST_WIDE_INT left_offset
,
2510 gimple_stmt_iterator
*old_gsi
,
2511 gimple_stmt_iterator
*new_gsi
,
2512 enum unscalarized_data_handling
*refreshed
)
2514 location_t loc
= gimple_location (gsi_stmt (*old_gsi
));
2515 for (lacc
= lacc
->first_child
; lacc
; lacc
= lacc
->next_sibling
)
2517 if (lacc
->grp_to_be_replaced
)
2519 struct access
*racc
;
2520 HOST_WIDE_INT offset
= lacc
->offset
- left_offset
+ top_racc
->offset
;
2524 racc
= find_access_in_subtree (top_racc
, offset
, lacc
->size
);
2525 if (racc
&& racc
->grp_to_be_replaced
)
2527 rhs
= get_access_replacement (racc
);
2528 if (!useless_type_conversion_p (lacc
->type
, racc
->type
))
2529 rhs
= fold_build1_loc (loc
, VIEW_CONVERT_EXPR
, lacc
->type
, rhs
);
2533 /* No suitable access on the right hand side, need to load from
2534 the aggregate. See if we have to update it first... */
2535 if (*refreshed
== SRA_UDH_NONE
)
2536 *refreshed
= handle_unscalarized_data_in_subtree (top_racc
,
2539 if (*refreshed
== SRA_UDH_LEFT
)
2540 rhs
= build_ref_for_model (loc
, lacc
->base
, lacc
->offset
, lacc
,
2543 rhs
= build_ref_for_model (loc
, top_racc
->base
, offset
, lacc
,
2547 stmt
= gimple_build_assign (get_access_replacement (lacc
), rhs
);
2548 gsi_insert_after (new_gsi
, stmt
, GSI_NEW_STMT
);
2549 gimple_set_location (stmt
, loc
);
2551 sra_stats
.subreplacements
++;
2553 else if (*refreshed
== SRA_UDH_NONE
2554 && lacc
->grp_read
&& !lacc
->grp_covered
)
2555 *refreshed
= handle_unscalarized_data_in_subtree (top_racc
,
2558 if (lacc
->first_child
)
2559 load_assign_lhs_subreplacements (lacc
, top_racc
, left_offset
,
2560 old_gsi
, new_gsi
, refreshed
);
2564 /* Result code for SRA assignment modification. */
2565 enum assignment_mod_result
{ SRA_AM_NONE
, /* nothing done for the stmt */
2566 SRA_AM_MODIFIED
, /* stmt changed but not
2568 SRA_AM_REMOVED
}; /* stmt eliminated */
2570 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2571 to the assignment and GSI is the statement iterator pointing at it. Returns
2572 the same values as sra_modify_assign. */
2574 static enum assignment_mod_result
2575 sra_modify_constructor_assign (gimple
*stmt
, gimple_stmt_iterator
*gsi
)
2577 tree lhs
= gimple_assign_lhs (*stmt
);
2581 acc
= get_access_for_expr (lhs
);
2585 loc
= gimple_location (*stmt
);
2586 if (VEC_length (constructor_elt
,
2587 CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt
))) > 0)
2589 /* I have never seen this code path trigger but if it can happen the
2590 following should handle it gracefully. */
2591 if (access_has_children_p (acc
))
2592 generate_subtree_copies (acc
->first_child
, acc
->base
, 0, 0, 0, gsi
,
2594 return SRA_AM_MODIFIED
;
2597 if (acc
->grp_covered
)
2599 init_subtree_with_zero (acc
, gsi
, false, loc
);
2600 unlink_stmt_vdef (*stmt
);
2601 gsi_remove (gsi
, true);
2602 return SRA_AM_REMOVED
;
2606 init_subtree_with_zero (acc
, gsi
, true, loc
);
2607 return SRA_AM_MODIFIED
;
2611 /* Create and return a new suitable default definition SSA_NAME for RACC which
2612 is an access describing an uninitialized part of an aggregate that is being
2616 get_repl_default_def_ssa_name (struct access
*racc
)
2620 decl
= get_unrenamed_access_replacement (racc
);
2622 repl
= gimple_default_def (cfun
, decl
);
2625 repl
= make_ssa_name (decl
, gimple_build_nop ());
2626 set_default_def (decl
, repl
);
2632 /* Examine both sides of the assignment statement pointed to by STMT, replace
2633 them with a scalare replacement if there is one and generate copying of
2634 replacements if scalarized aggregates have been used in the assignment. GSI
2635 is used to hold generated statements for type conversions and subtree
2638 static enum assignment_mod_result
2639 sra_modify_assign (gimple
*stmt
, gimple_stmt_iterator
*gsi
)
2641 struct access
*lacc
, *racc
;
2643 bool modify_this_stmt
= false;
2644 bool force_gimple_rhs
= false;
2646 gimple_stmt_iterator orig_gsi
= *gsi
;
2648 if (!gimple_assign_single_p (*stmt
))
2650 lhs
= gimple_assign_lhs (*stmt
);
2651 rhs
= gimple_assign_rhs1 (*stmt
);
2653 if (TREE_CODE (rhs
) == CONSTRUCTOR
)
2654 return sra_modify_constructor_assign (stmt
, gsi
);
2656 if (TREE_CODE (rhs
) == REALPART_EXPR
|| TREE_CODE (lhs
) == REALPART_EXPR
2657 || TREE_CODE (rhs
) == IMAGPART_EXPR
|| TREE_CODE (lhs
) == IMAGPART_EXPR
2658 || TREE_CODE (rhs
) == BIT_FIELD_REF
|| TREE_CODE (lhs
) == BIT_FIELD_REF
)
2660 modify_this_stmt
= sra_modify_expr (gimple_assign_rhs1_ptr (*stmt
),
2662 modify_this_stmt
|= sra_modify_expr (gimple_assign_lhs_ptr (*stmt
),
2664 return modify_this_stmt
? SRA_AM_MODIFIED
: SRA_AM_NONE
;
2667 lacc
= get_access_for_expr (lhs
);
2668 racc
= get_access_for_expr (rhs
);
2672 loc
= gimple_location (*stmt
);
2673 if (lacc
&& lacc
->grp_to_be_replaced
)
2675 lhs
= get_access_replacement (lacc
);
2676 gimple_assign_set_lhs (*stmt
, lhs
);
2677 modify_this_stmt
= true;
2678 if (lacc
->grp_partial_lhs
)
2679 force_gimple_rhs
= true;
2683 if (racc
&& racc
->grp_to_be_replaced
)
2685 rhs
= get_access_replacement (racc
);
2686 modify_this_stmt
= true;
2687 if (racc
->grp_partial_lhs
)
2688 force_gimple_rhs
= true;
2692 if (modify_this_stmt
)
2694 if (!useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (rhs
)))
2696 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
2697 ??? This should move to fold_stmt which we simply should
2698 call after building a VIEW_CONVERT_EXPR here. */
2699 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs
))
2700 && !access_has_children_p (lacc
))
2702 lhs
= build_ref_for_offset (loc
, lhs
, 0, TREE_TYPE (rhs
),
2704 gimple_assign_set_lhs (*stmt
, lhs
);
2706 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs
))
2707 && !contains_view_convert_expr_p (rhs
)
2708 && !access_has_children_p (racc
))
2709 rhs
= build_ref_for_offset (loc
, rhs
, 0, TREE_TYPE (lhs
),
2712 if (!useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (rhs
)))
2714 rhs
= fold_build1_loc (loc
, VIEW_CONVERT_EXPR
, TREE_TYPE (lhs
),
2716 if (is_gimple_reg_type (TREE_TYPE (lhs
))
2717 && TREE_CODE (lhs
) != SSA_NAME
)
2718 force_gimple_rhs
= true;
2723 /* From this point on, the function deals with assignments in between
2724 aggregates when at least one has scalar reductions of some of its
2725 components. There are three possible scenarios: Both the LHS and RHS have
2726 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
2728 In the first case, we would like to load the LHS components from RHS
2729 components whenever possible. If that is not possible, we would like to
2730 read it directly from the RHS (after updating it by storing in it its own
2731 components). If there are some necessary unscalarized data in the LHS,
2732 those will be loaded by the original assignment too. If neither of these
2733 cases happen, the original statement can be removed. Most of this is done
2734 by load_assign_lhs_subreplacements.
2736 In the second case, we would like to store all RHS scalarized components
2737 directly into LHS and if they cover the aggregate completely, remove the
2738 statement too. In the third case, we want the LHS components to be loaded
2739 directly from the RHS (DSE will remove the original statement if it
2742 This is a bit complex but manageable when types match and when unions do
2743 not cause confusion in a way that we cannot really load a component of LHS
2744 from the RHS or vice versa (the access representing this level can have
2745 subaccesses that are accessible only through a different union field at a
2746 higher level - different from the one used in the examined expression).
2749 Therefore, I specially handle a fourth case, happening when there is a
2750 specific type cast or it is impossible to locate a scalarized subaccess on
2751 the other side of the expression. If that happens, I simply "refresh" the
2752 RHS by storing in it is scalarized components leave the original statement
2753 there to do the copying and then load the scalar replacements of the LHS.
2754 This is what the first branch does. */
2756 if (gimple_has_volatile_ops (*stmt
)
2757 || contains_view_convert_expr_p (rhs
)
2758 || contains_view_convert_expr_p (lhs
))
2760 if (access_has_children_p (racc
))
2761 generate_subtree_copies (racc
->first_child
, racc
->base
, 0, 0, 0,
2762 gsi
, false, false, loc
);
2763 if (access_has_children_p (lacc
))
2764 generate_subtree_copies (lacc
->first_child
, lacc
->base
, 0, 0, 0,
2765 gsi
, true, true, loc
);
2766 sra_stats
.separate_lhs_rhs_handling
++;
2770 if (access_has_children_p (lacc
) && access_has_children_p (racc
))
2772 gimple_stmt_iterator orig_gsi
= *gsi
;
2773 enum unscalarized_data_handling refreshed
;
2775 if (lacc
->grp_read
&& !lacc
->grp_covered
)
2776 refreshed
= handle_unscalarized_data_in_subtree (racc
, gsi
);
2778 refreshed
= SRA_UDH_NONE
;
2780 load_assign_lhs_subreplacements (lacc
, racc
, lacc
->offset
,
2781 &orig_gsi
, gsi
, &refreshed
);
2782 if (refreshed
!= SRA_UDH_RIGHT
)
2785 unlink_stmt_vdef (*stmt
);
2786 gsi_remove (&orig_gsi
, true);
2787 sra_stats
.deleted
++;
2788 return SRA_AM_REMOVED
;
2795 if (!racc
->grp_to_be_replaced
&& !racc
->grp_unscalarized_data
)
2799 fprintf (dump_file
, "Removing load: ");
2800 print_gimple_stmt (dump_file
, *stmt
, 0, 0);
2803 if (TREE_CODE (lhs
) == SSA_NAME
)
2805 rhs
= get_repl_default_def_ssa_name (racc
);
2806 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
2808 rhs
= fold_build1_loc (loc
, VIEW_CONVERT_EXPR
,
2809 TREE_TYPE (lhs
), rhs
);
2813 if (racc
->first_child
)
2814 generate_subtree_copies (racc
->first_child
, lhs
,
2815 racc
->offset
, 0, 0, gsi
,
2818 gcc_assert (*stmt
== gsi_stmt (*gsi
));
2819 unlink_stmt_vdef (*stmt
);
2820 gsi_remove (gsi
, true);
2821 sra_stats
.deleted
++;
2822 return SRA_AM_REMOVED
;
2825 else if (racc
->first_child
)
2826 generate_subtree_copies (racc
->first_child
, lhs
, racc
->offset
,
2827 0, 0, gsi
, false, true, loc
);
2829 if (access_has_children_p (lacc
))
2830 generate_subtree_copies (lacc
->first_child
, rhs
, lacc
->offset
,
2831 0, 0, gsi
, true, true, loc
);
2835 /* This gimplification must be done after generate_subtree_copies, lest we
2836 insert the subtree copies in the middle of the gimplified sequence. */
2837 if (force_gimple_rhs
)
2838 rhs
= force_gimple_operand_gsi (&orig_gsi
, rhs
, true, NULL_TREE
,
2839 true, GSI_SAME_STMT
);
2840 if (gimple_assign_rhs1 (*stmt
) != rhs
)
2842 modify_this_stmt
= true;
2843 gimple_assign_set_rhs_from_tree (&orig_gsi
, rhs
);
2844 gcc_assert (*stmt
== gsi_stmt (orig_gsi
));
2847 return modify_this_stmt
? SRA_AM_MODIFIED
: SRA_AM_NONE
;
2850 /* Traverse the function body and all modifications as decided in
2851 analyze_all_variable_accesses. Return true iff the CFG has been
2855 sra_modify_function_body (void)
2857 bool cfg_changed
= false;
2862 gimple_stmt_iterator gsi
= gsi_start_bb (bb
);
2863 while (!gsi_end_p (gsi
))
2865 gimple stmt
= gsi_stmt (gsi
);
2866 enum assignment_mod_result assign_result
;
2867 bool modified
= false, deleted
= false;
2871 switch (gimple_code (stmt
))
2874 t
= gimple_return_retval_ptr (stmt
);
2875 if (*t
!= NULL_TREE
)
2876 modified
|= sra_modify_expr (t
, &gsi
, false);
2880 assign_result
= sra_modify_assign (&stmt
, &gsi
);
2881 modified
|= assign_result
== SRA_AM_MODIFIED
;
2882 deleted
= assign_result
== SRA_AM_REMOVED
;
2886 /* Operands must be processed before the lhs. */
2887 for (i
= 0; i
< gimple_call_num_args (stmt
); i
++)
2889 t
= gimple_call_arg_ptr (stmt
, i
);
2890 modified
|= sra_modify_expr (t
, &gsi
, false);
2893 if (gimple_call_lhs (stmt
))
2895 t
= gimple_call_lhs_ptr (stmt
);
2896 modified
|= sra_modify_expr (t
, &gsi
, true);
2901 for (i
= 0; i
< gimple_asm_ninputs (stmt
); i
++)
2903 t
= &TREE_VALUE (gimple_asm_input_op (stmt
, i
));
2904 modified
|= sra_modify_expr (t
, &gsi
, false);
2906 for (i
= 0; i
< gimple_asm_noutputs (stmt
); i
++)
2908 t
= &TREE_VALUE (gimple_asm_output_op (stmt
, i
));
2909 modified
|= sra_modify_expr (t
, &gsi
, true);
2920 if (maybe_clean_eh_stmt (stmt
)
2921 && gimple_purge_dead_eh_edges (gimple_bb (stmt
)))
2932 /* Generate statements initializing scalar replacements of parts of function
2936 initialize_parameter_reductions (void)
2938 gimple_stmt_iterator gsi
;
2939 gimple_seq seq
= NULL
;
2942 for (parm
= DECL_ARGUMENTS (current_function_decl
);
2944 parm
= DECL_CHAIN (parm
))
2946 VEC (access_p
, heap
) *access_vec
;
2947 struct access
*access
;
2949 if (!bitmap_bit_p (candidate_bitmap
, DECL_UID (parm
)))
2951 access_vec
= get_base_access_vector (parm
);
2957 seq
= gimple_seq_alloc ();
2958 gsi
= gsi_start (seq
);
2961 for (access
= VEC_index (access_p
, access_vec
, 0);
2963 access
= access
->next_grp
)
2964 generate_subtree_copies (access
, parm
, 0, 0, 0, &gsi
, true, true,
2965 EXPR_LOCATION (parm
));
2969 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR
), seq
);
2972 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
2973 it reveals there are components of some aggregates to be scalarized, it runs
2974 the required transformations. */
2976 perform_intra_sra (void)
2981 if (!find_var_candidates ())
2984 if (!scan_function ())
2987 if (!analyze_all_variable_accesses ())
2990 if (sra_modify_function_body ())
2991 ret
= TODO_update_ssa
| TODO_cleanup_cfg
;
2993 ret
= TODO_update_ssa
;
2994 initialize_parameter_reductions ();
2996 statistics_counter_event (cfun
, "Scalar replacements created",
2997 sra_stats
.replacements
);
2998 statistics_counter_event (cfun
, "Modified expressions", sra_stats
.exprs
);
2999 statistics_counter_event (cfun
, "Subtree copy stmts",
3000 sra_stats
.subtree_copies
);
3001 statistics_counter_event (cfun
, "Subreplacement stmts",
3002 sra_stats
.subreplacements
);
3003 statistics_counter_event (cfun
, "Deleted stmts", sra_stats
.deleted
);
3004 statistics_counter_event (cfun
, "Separate LHS and RHS handling",
3005 sra_stats
.separate_lhs_rhs_handling
);
3008 sra_deinitialize ();
3012 /* Perform early intraprocedural SRA. */
3014 early_intra_sra (void)
3016 sra_mode
= SRA_MODE_EARLY_INTRA
;
3017 return perform_intra_sra ();
3020 /* Perform "late" intraprocedural SRA. */
3022 late_intra_sra (void)
3024 sra_mode
= SRA_MODE_INTRA
;
3025 return perform_intra_sra ();
3030 gate_intra_sra (void)
3032 return flag_tree_sra
!= 0 && dbg_cnt (tree_sra
);
3036 struct gimple_opt_pass pass_sra_early
=
3041 gate_intra_sra
, /* gate */
3042 early_intra_sra
, /* execute */
3045 0, /* static_pass_number */
3046 TV_TREE_SRA
, /* tv_id */
3047 PROP_cfg
| PROP_ssa
, /* properties_required */
3048 0, /* properties_provided */
3049 0, /* properties_destroyed */
3050 0, /* todo_flags_start */
3054 | TODO_verify_ssa
/* todo_flags_finish */
3058 struct gimple_opt_pass pass_sra
=
3063 gate_intra_sra
, /* gate */
3064 late_intra_sra
, /* execute */
3067 0, /* static_pass_number */
3068 TV_TREE_SRA
, /* tv_id */
3069 PROP_cfg
| PROP_ssa
, /* properties_required */
3070 0, /* properties_provided */
3071 0, /* properties_destroyed */
3072 TODO_update_address_taken
, /* todo_flags_start */
3076 | TODO_verify_ssa
/* todo_flags_finish */
3081 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3085 is_unused_scalar_param (tree parm
)
3088 return (is_gimple_reg (parm
)
3089 && (!(name
= gimple_default_def (cfun
, parm
))
3090 || has_zero_uses (name
)));
3093 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3094 examine whether there are any direct or otherwise infeasible ones. If so,
3095 return true, otherwise return false. PARM must be a gimple register with a
3096 non-NULL default definition. */
3099 ptr_parm_has_direct_uses (tree parm
)
3101 imm_use_iterator ui
;
3103 tree name
= gimple_default_def (cfun
, parm
);
3106 FOR_EACH_IMM_USE_STMT (stmt
, ui
, name
)
3109 use_operand_p use_p
;
3111 if (is_gimple_debug (stmt
))
3114 /* Valid uses include dereferences on the lhs and the rhs. */
3115 if (gimple_has_lhs (stmt
))
3117 tree lhs
= gimple_get_lhs (stmt
);
3118 while (handled_component_p (lhs
))
3119 lhs
= TREE_OPERAND (lhs
, 0);
3120 if (TREE_CODE (lhs
) == MEM_REF
3121 && TREE_OPERAND (lhs
, 0) == name
3122 && integer_zerop (TREE_OPERAND (lhs
, 1))
3123 && types_compatible_p (TREE_TYPE (lhs
),
3124 TREE_TYPE (TREE_TYPE (name
))))
3127 if (gimple_assign_single_p (stmt
))
3129 tree rhs
= gimple_assign_rhs1 (stmt
);
3130 while (handled_component_p (rhs
))
3131 rhs
= TREE_OPERAND (rhs
, 0);
3132 if (TREE_CODE (rhs
) == MEM_REF
3133 && TREE_OPERAND (rhs
, 0) == name
3134 && integer_zerop (TREE_OPERAND (rhs
, 1))
3135 && types_compatible_p (TREE_TYPE (rhs
),
3136 TREE_TYPE (TREE_TYPE (name
))))
3139 else if (is_gimple_call (stmt
))
3142 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
3144 tree arg
= gimple_call_arg (stmt
, i
);
3145 while (handled_component_p (arg
))
3146 arg
= TREE_OPERAND (arg
, 0);
3147 if (TREE_CODE (arg
) == MEM_REF
3148 && TREE_OPERAND (arg
, 0) == name
3149 && integer_zerop (TREE_OPERAND (arg
, 1))
3150 && types_compatible_p (TREE_TYPE (arg
),
3151 TREE_TYPE (TREE_TYPE (name
))))
3156 /* If the number of valid uses does not match the number of
3157 uses in this stmt there is an unhandled use. */
3158 FOR_EACH_IMM_USE_ON_STMT (use_p
, ui
)
3165 BREAK_FROM_IMM_USE_STMT (ui
);
3171 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3172 them in candidate_bitmap. Note that these do not necessarily include
3173 parameter which are unused and thus can be removed. Return true iff any
3174 such candidate has been found. */
3177 find_param_candidates (void)
3183 for (parm
= DECL_ARGUMENTS (current_function_decl
);
3185 parm
= DECL_CHAIN (parm
))
3187 tree type
= TREE_TYPE (parm
);
3191 if (TREE_THIS_VOLATILE (parm
)
3192 || TREE_ADDRESSABLE (parm
)
3193 || (!is_gimple_reg_type (type
) && is_va_list_type (type
)))
3196 if (is_unused_scalar_param (parm
))
3202 if (POINTER_TYPE_P (type
))
3204 type
= TREE_TYPE (type
);
3206 if (TREE_CODE (type
) == FUNCTION_TYPE
3207 || TYPE_VOLATILE (type
)
3208 || (TREE_CODE (type
) == ARRAY_TYPE
3209 && TYPE_NONALIASED_COMPONENT (type
))
3210 || !is_gimple_reg (parm
)
3211 || is_va_list_type (type
)
3212 || ptr_parm_has_direct_uses (parm
))
3215 else if (!AGGREGATE_TYPE_P (type
))
3218 if (!COMPLETE_TYPE_P (type
)
3219 || !host_integerp (TYPE_SIZE (type
), 1)
3220 || tree_low_cst (TYPE_SIZE (type
), 1) == 0
3221 || (AGGREGATE_TYPE_P (type
)
3222 && type_internals_preclude_sra_p (type
)))
3225 bitmap_set_bit (candidate_bitmap
, DECL_UID (parm
));
3227 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3229 fprintf (dump_file
, "Candidate (%d): ", DECL_UID (parm
));
3230 print_generic_expr (dump_file
, parm
, 0);
3231 fprintf (dump_file
, "\n");
3235 func_param_count
= count
;
3239 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3243 mark_maybe_modified (ao_ref
*ao ATTRIBUTE_UNUSED
, tree vdef ATTRIBUTE_UNUSED
,
3246 struct access
*repr
= (struct access
*) data
;
3248 repr
->grp_maybe_modified
= 1;
3252 /* Analyze what representatives (in linked lists accessible from
3253 REPRESENTATIVES) can be modified by side effects of statements in the
3254 current function. */
3257 analyze_modified_params (VEC (access_p
, heap
) *representatives
)
3261 for (i
= 0; i
< func_param_count
; i
++)
3263 struct access
*repr
;
3265 for (repr
= VEC_index (access_p
, representatives
, i
);
3267 repr
= repr
->next_grp
)
3269 struct access
*access
;
3273 if (no_accesses_p (repr
))
3275 if (!POINTER_TYPE_P (TREE_TYPE (repr
->base
))
3276 || repr
->grp_maybe_modified
)
3279 ao_ref_init (&ar
, repr
->expr
);
3280 visited
= BITMAP_ALLOC (NULL
);
3281 for (access
= repr
; access
; access
= access
->next_sibling
)
3283 /* All accesses are read ones, otherwise grp_maybe_modified would
3284 be trivially set. */
3285 walk_aliased_vdefs (&ar
, gimple_vuse (access
->stmt
),
3286 mark_maybe_modified
, repr
, &visited
);
3287 if (repr
->grp_maybe_modified
)
3290 BITMAP_FREE (visited
);
3295 /* Propagate distances in bb_dereferences in the opposite direction than the
3296 control flow edges, in each step storing the maximum of the current value
3297 and the minimum of all successors. These steps are repeated until the table
3298 stabilizes. Note that BBs which might terminate the functions (according to
3299 final_bbs bitmap) never updated in this way. */
3302 propagate_dereference_distances (void)
3304 VEC (basic_block
, heap
) *queue
;
3307 queue
= VEC_alloc (basic_block
, heap
, last_basic_block_for_function (cfun
));
3308 VEC_quick_push (basic_block
, queue
, ENTRY_BLOCK_PTR
);
3311 VEC_quick_push (basic_block
, queue
, bb
);
3315 while (!VEC_empty (basic_block
, queue
))
3319 bool change
= false;
3322 bb
= VEC_pop (basic_block
, queue
);
3325 if (bitmap_bit_p (final_bbs
, bb
->index
))
3328 for (i
= 0; i
< func_param_count
; i
++)
3330 int idx
= bb
->index
* func_param_count
+ i
;
3332 HOST_WIDE_INT inh
= 0;
3334 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3336 int succ_idx
= e
->dest
->index
* func_param_count
+ i
;
3338 if (e
->src
== EXIT_BLOCK_PTR
)
3344 inh
= bb_dereferences
[succ_idx
];
3346 else if (bb_dereferences
[succ_idx
] < inh
)
3347 inh
= bb_dereferences
[succ_idx
];
3350 if (!first
&& bb_dereferences
[idx
] < inh
)
3352 bb_dereferences
[idx
] = inh
;
3357 if (change
&& !bitmap_bit_p (final_bbs
, bb
->index
))
3358 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3363 e
->src
->aux
= e
->src
;
3364 VEC_quick_push (basic_block
, queue
, e
->src
);
3368 VEC_free (basic_block
, heap
, queue
);
3371 /* Dump a dereferences TABLE with heading STR to file F. */
3374 dump_dereferences_table (FILE *f
, const char *str
, HOST_WIDE_INT
*table
)
3378 fprintf (dump_file
, str
);
3379 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, EXIT_BLOCK_PTR
, next_bb
)
3381 fprintf (f
, "%4i %i ", bb
->index
, bitmap_bit_p (final_bbs
, bb
->index
));
3382 if (bb
!= EXIT_BLOCK_PTR
)
3385 for (i
= 0; i
< func_param_count
; i
++)
3387 int idx
= bb
->index
* func_param_count
+ i
;
3388 fprintf (f
, " %4" HOST_WIDE_INT_PRINT
"d", table
[idx
]);
3393 fprintf (dump_file
, "\n");
3396 /* Determine what (parts of) parameters passed by reference that are not
3397 assigned to are not certainly dereferenced in this function and thus the
3398 dereferencing cannot be safely moved to the caller without potentially
3399 introducing a segfault. Mark such REPRESENTATIVES as
3400 grp_not_necessarilly_dereferenced.
3402 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3403 part is calculated rather than simple booleans are calculated for each
3404 pointer parameter to handle cases when only a fraction of the whole
3405 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3408 The maximum dereference distances for each pointer parameter and BB are
3409 already stored in bb_dereference. This routine simply propagates these
3410 values upwards by propagate_dereference_distances and then compares the
3411 distances of individual parameters in the ENTRY BB to the equivalent
3412 distances of each representative of a (fraction of a) parameter. */
3415 analyze_caller_dereference_legality (VEC (access_p
, heap
) *representatives
)
3419 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3420 dump_dereferences_table (dump_file
,
3421 "Dereference table before propagation:\n",
3424 propagate_dereference_distances ();
3426 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3427 dump_dereferences_table (dump_file
,
3428 "Dereference table after propagation:\n",
3431 for (i
= 0; i
< func_param_count
; i
++)
3433 struct access
*repr
= VEC_index (access_p
, representatives
, i
);
3434 int idx
= ENTRY_BLOCK_PTR
->index
* func_param_count
+ i
;
3436 if (!repr
|| no_accesses_p (repr
))
3441 if ((repr
->offset
+ repr
->size
) > bb_dereferences
[idx
])
3442 repr
->grp_not_necessarilly_dereferenced
= 1;
3443 repr
= repr
->next_grp
;
3449 /* Return the representative access for the parameter declaration PARM if it is
3450 a scalar passed by reference which is not written to and the pointer value
3451 is not used directly. Thus, if it is legal to dereference it in the caller
3452 and we can rule out modifications through aliases, such parameter should be
3453 turned into one passed by value. Return NULL otherwise. */
3455 static struct access
*
3456 unmodified_by_ref_scalar_representative (tree parm
)
3458 int i
, access_count
;
3459 struct access
*repr
;
3460 VEC (access_p
, heap
) *access_vec
;
3462 access_vec
= get_base_access_vector (parm
);
3463 gcc_assert (access_vec
);
3464 repr
= VEC_index (access_p
, access_vec
, 0);
3467 repr
->group_representative
= repr
;
3469 access_count
= VEC_length (access_p
, access_vec
);
3470 for (i
= 1; i
< access_count
; i
++)
3472 struct access
*access
= VEC_index (access_p
, access_vec
, i
);
3475 access
->group_representative
= repr
;
3476 access
->next_sibling
= repr
->next_sibling
;
3477 repr
->next_sibling
= access
;
3481 repr
->grp_scalar_ptr
= 1;
3485 /* Return true iff this access precludes IPA-SRA of the parameter it is
3489 access_precludes_ipa_sra_p (struct access
*access
)
3491 /* Avoid issues such as the second simple testcase in PR 42025. The problem
3492 is incompatible assign in a call statement (and possibly even in asm
3493 statements). This can be relaxed by using a new temporary but only for
3494 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
3495 intraprocedural SRA we deal with this by keeping the old aggregate around,
3496 something we cannot do in IPA-SRA.) */
3498 && (is_gimple_call (access
->stmt
)
3499 || gimple_code (access
->stmt
) == GIMPLE_ASM
))
3506 /* Sort collected accesses for parameter PARM, identify representatives for
3507 each accessed region and link them together. Return NULL if there are
3508 different but overlapping accesses, return the special ptr value meaning
3509 there are no accesses for this parameter if that is the case and return the
3510 first representative otherwise. Set *RO_GRP if there is a group of accesses
3511 with only read (i.e. no write) accesses. */
3513 static struct access
*
3514 splice_param_accesses (tree parm
, bool *ro_grp
)
3516 int i
, j
, access_count
, group_count
;
3517 int agg_size
, total_size
= 0;
3518 struct access
*access
, *res
, **prev_acc_ptr
= &res
;
3519 VEC (access_p
, heap
) *access_vec
;
3521 access_vec
= get_base_access_vector (parm
);
3523 return &no_accesses_representant
;
3524 access_count
= VEC_length (access_p
, access_vec
);
3526 VEC_qsort (access_p
, access_vec
, compare_access_positions
);
3531 while (i
< access_count
)
3534 access
= VEC_index (access_p
, access_vec
, i
);
3535 modification
= access
->write
;
3536 if (access_precludes_ipa_sra_p (access
))
3539 /* Access is about to become group representative unless we find some
3540 nasty overlap which would preclude us from breaking this parameter
3544 while (j
< access_count
)
3546 struct access
*ac2
= VEC_index (access_p
, access_vec
, j
);
3547 if (ac2
->offset
!= access
->offset
)
3549 /* All or nothing law for parameters. */
3550 if (access
->offset
+ access
->size
> ac2
->offset
)
3555 else if (ac2
->size
!= access
->size
)
3558 if (access_precludes_ipa_sra_p (ac2
))
3561 modification
|= ac2
->write
;
3562 ac2
->group_representative
= access
;
3563 ac2
->next_sibling
= access
->next_sibling
;
3564 access
->next_sibling
= ac2
;
3569 access
->grp_maybe_modified
= modification
;
3572 *prev_acc_ptr
= access
;
3573 prev_acc_ptr
= &access
->next_grp
;
3574 total_size
+= access
->size
;
3578 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
3579 agg_size
= tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm
))), 1);
3581 agg_size
= tree_low_cst (TYPE_SIZE (TREE_TYPE (parm
)), 1);
3582 if (total_size
>= agg_size
)
3585 gcc_assert (group_count
> 0);
3589 /* Decide whether parameters with representative accesses given by REPR should
3590 be reduced into components. */
3593 decide_one_param_reduction (struct access
*repr
)
3595 int total_size
, cur_parm_size
, agg_size
, new_param_count
, parm_size_limit
;
3600 cur_parm_size
= tree_low_cst (TYPE_SIZE (TREE_TYPE (parm
)), 1);
3601 gcc_assert (cur_parm_size
> 0);
3603 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
3606 agg_size
= tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm
))), 1);
3611 agg_size
= cur_parm_size
;
3617 fprintf (dump_file
, "Evaluating PARAM group sizes for ");
3618 print_generic_expr (dump_file
, parm
, 0);
3619 fprintf (dump_file
, " (UID: %u): \n", DECL_UID (parm
));
3620 for (acc
= repr
; acc
; acc
= acc
->next_grp
)
3621 dump_access (dump_file
, acc
, true);
3625 new_param_count
= 0;
3627 for (; repr
; repr
= repr
->next_grp
)
3629 gcc_assert (parm
== repr
->base
);
3632 if (!by_ref
|| (!repr
->grp_maybe_modified
3633 && !repr
->grp_not_necessarilly_dereferenced
))
3634 total_size
+= repr
->size
;
3636 total_size
+= cur_parm_size
;
3639 gcc_assert (new_param_count
> 0);
3641 if (optimize_function_for_size_p (cfun
))
3642 parm_size_limit
= cur_parm_size
;
3644 parm_size_limit
= (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR
)
3647 if (total_size
< agg_size
3648 && total_size
<= parm_size_limit
)
3651 fprintf (dump_file
, " ....will be split into %i components\n",
3653 return new_param_count
;
3659 /* The order of the following enums is important, we need to do extra work for
3660 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
3661 enum ipa_splicing_result
{ NO_GOOD_ACCESS
, UNUSED_PARAMS
, BY_VAL_ACCESSES
,
3662 MODIF_BY_REF_ACCESSES
, UNMODIF_BY_REF_ACCESSES
};
3664 /* Identify representatives of all accesses to all candidate parameters for
3665 IPA-SRA. Return result based on what representatives have been found. */
3667 static enum ipa_splicing_result
3668 splice_all_param_accesses (VEC (access_p
, heap
) **representatives
)
3670 enum ipa_splicing_result result
= NO_GOOD_ACCESS
;
3672 struct access
*repr
;
3674 *representatives
= VEC_alloc (access_p
, heap
, func_param_count
);
3676 for (parm
= DECL_ARGUMENTS (current_function_decl
);
3678 parm
= DECL_CHAIN (parm
))
3680 if (is_unused_scalar_param (parm
))
3682 VEC_quick_push (access_p
, *representatives
,
3683 &no_accesses_representant
);
3684 if (result
== NO_GOOD_ACCESS
)
3685 result
= UNUSED_PARAMS
;
3687 else if (POINTER_TYPE_P (TREE_TYPE (parm
))
3688 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm
)))
3689 && bitmap_bit_p (candidate_bitmap
, DECL_UID (parm
)))
3691 repr
= unmodified_by_ref_scalar_representative (parm
);
3692 VEC_quick_push (access_p
, *representatives
, repr
);
3694 result
= UNMODIF_BY_REF_ACCESSES
;
3696 else if (bitmap_bit_p (candidate_bitmap
, DECL_UID (parm
)))
3698 bool ro_grp
= false;
3699 repr
= splice_param_accesses (parm
, &ro_grp
);
3700 VEC_quick_push (access_p
, *representatives
, repr
);
3702 if (repr
&& !no_accesses_p (repr
))
3704 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
3707 result
= UNMODIF_BY_REF_ACCESSES
;
3708 else if (result
< MODIF_BY_REF_ACCESSES
)
3709 result
= MODIF_BY_REF_ACCESSES
;
3711 else if (result
< BY_VAL_ACCESSES
)
3712 result
= BY_VAL_ACCESSES
;
3714 else if (no_accesses_p (repr
) && (result
== NO_GOOD_ACCESS
))
3715 result
= UNUSED_PARAMS
;
3718 VEC_quick_push (access_p
, *representatives
, NULL
);
3721 if (result
== NO_GOOD_ACCESS
)
3723 VEC_free (access_p
, heap
, *representatives
);
3724 *representatives
= NULL
;
3725 return NO_GOOD_ACCESS
;
3731 /* Return the index of BASE in PARMS. Abort if it is not found. */
3734 get_param_index (tree base
, VEC(tree
, heap
) *parms
)
3738 len
= VEC_length (tree
, parms
);
3739 for (i
= 0; i
< len
; i
++)
3740 if (VEC_index (tree
, parms
, i
) == base
)
3745 /* Convert the decisions made at the representative level into compact
3746 parameter adjustments. REPRESENTATIVES are pointers to first
3747 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
3748 final number of adjustments. */
3750 static ipa_parm_adjustment_vec
3751 turn_representatives_into_adjustments (VEC (access_p
, heap
) *representatives
,
3752 int adjustments_count
)
3754 VEC (tree
, heap
) *parms
;
3755 ipa_parm_adjustment_vec adjustments
;
3759 gcc_assert (adjustments_count
> 0);
3760 parms
= ipa_get_vector_of_formal_parms (current_function_decl
);
3761 adjustments
= VEC_alloc (ipa_parm_adjustment_t
, heap
, adjustments_count
);
3762 parm
= DECL_ARGUMENTS (current_function_decl
);
3763 for (i
= 0; i
< func_param_count
; i
++, parm
= DECL_CHAIN (parm
))
3765 struct access
*repr
= VEC_index (access_p
, representatives
, i
);
3767 if (!repr
|| no_accesses_p (repr
))
3769 struct ipa_parm_adjustment
*adj
;
3771 adj
= VEC_quick_push (ipa_parm_adjustment_t
, adjustments
, NULL
);
3772 memset (adj
, 0, sizeof (*adj
));
3773 adj
->base_index
= get_param_index (parm
, parms
);
3776 adj
->copy_param
= 1;
3778 adj
->remove_param
= 1;
3782 struct ipa_parm_adjustment
*adj
;
3783 int index
= get_param_index (parm
, parms
);
3785 for (; repr
; repr
= repr
->next_grp
)
3787 adj
= VEC_quick_push (ipa_parm_adjustment_t
, adjustments
, NULL
);
3788 memset (adj
, 0, sizeof (*adj
));
3789 gcc_assert (repr
->base
== parm
);
3790 adj
->base_index
= index
;
3791 adj
->base
= repr
->base
;
3792 adj
->type
= repr
->type
;
3793 adj
->offset
= repr
->offset
;
3794 adj
->by_ref
= (POINTER_TYPE_P (TREE_TYPE (repr
->base
))
3795 && (repr
->grp_maybe_modified
3796 || repr
->grp_not_necessarilly_dereferenced
));
3801 VEC_free (tree
, heap
, parms
);
3805 /* Analyze the collected accesses and produce a plan what to do with the
3806 parameters in the form of adjustments, NULL meaning nothing. */
3808 static ipa_parm_adjustment_vec
3809 analyze_all_param_acesses (void)
3811 enum ipa_splicing_result repr_state
;
3812 bool proceed
= false;
3813 int i
, adjustments_count
= 0;
3814 VEC (access_p
, heap
) *representatives
;
3815 ipa_parm_adjustment_vec adjustments
;
3817 repr_state
= splice_all_param_accesses (&representatives
);
3818 if (repr_state
== NO_GOOD_ACCESS
)
3821 /* If there are any parameters passed by reference which are not modified
3822 directly, we need to check whether they can be modified indirectly. */
3823 if (repr_state
== UNMODIF_BY_REF_ACCESSES
)
3825 analyze_caller_dereference_legality (representatives
);
3826 analyze_modified_params (representatives
);
3829 for (i
= 0; i
< func_param_count
; i
++)
3831 struct access
*repr
= VEC_index (access_p
, representatives
, i
);
3833 if (repr
&& !no_accesses_p (repr
))
3835 if (repr
->grp_scalar_ptr
)
3837 adjustments_count
++;
3838 if (repr
->grp_not_necessarilly_dereferenced
3839 || repr
->grp_maybe_modified
)
3840 VEC_replace (access_p
, representatives
, i
, NULL
);
3844 sra_stats
.scalar_by_ref_to_by_val
++;
3849 int new_components
= decide_one_param_reduction (repr
);
3851 if (new_components
== 0)
3853 VEC_replace (access_p
, representatives
, i
, NULL
);
3854 adjustments_count
++;
3858 adjustments_count
+= new_components
;
3859 sra_stats
.aggregate_params_reduced
++;
3860 sra_stats
.param_reductions_created
+= new_components
;
3867 if (no_accesses_p (repr
))
3870 sra_stats
.deleted_unused_parameters
++;
3872 adjustments_count
++;
3876 if (!proceed
&& dump_file
)
3877 fprintf (dump_file
, "NOT proceeding to change params.\n");
3880 adjustments
= turn_representatives_into_adjustments (representatives
,
3885 VEC_free (access_p
, heap
, representatives
);
3889 /* If a parameter replacement identified by ADJ does not yet exist in the form
3890 of declaration, create it and record it, otherwise return the previously
3894 get_replaced_param_substitute (struct ipa_parm_adjustment
*adj
)
3897 if (!adj
->new_ssa_base
)
3899 char *pretty_name
= make_fancy_name (adj
->base
);
3901 repl
= create_tmp_reg (TREE_TYPE (adj
->base
), "ISR");
3902 DECL_NAME (repl
) = get_identifier (pretty_name
);
3903 obstack_free (&name_obstack
, pretty_name
);
3906 add_referenced_var (repl
);
3907 adj
->new_ssa_base
= repl
;
3910 repl
= adj
->new_ssa_base
;
3914 /* Find the first adjustment for a particular parameter BASE in a vector of
3915 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
3918 static struct ipa_parm_adjustment
*
3919 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments
, tree base
)
3923 len
= VEC_length (ipa_parm_adjustment_t
, adjustments
);
3924 for (i
= 0; i
< len
; i
++)
3926 struct ipa_parm_adjustment
*adj
;
3928 adj
= VEC_index (ipa_parm_adjustment_t
, adjustments
, i
);
3929 if (!adj
->copy_param
&& adj
->base
== base
)
3936 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
3937 removed because its value is not used, replace the SSA_NAME with a one
3938 relating to a created VAR_DECL together all of its uses and return true.
3939 ADJUSTMENTS is a pointer to an adjustments vector. */
3942 replace_removed_params_ssa_names (gimple stmt
,
3943 ipa_parm_adjustment_vec adjustments
)
3945 struct ipa_parm_adjustment
*adj
;
3946 tree lhs
, decl
, repl
, name
;
3948 if (gimple_code (stmt
) == GIMPLE_PHI
)
3949 lhs
= gimple_phi_result (stmt
);
3950 else if (is_gimple_assign (stmt
))
3951 lhs
= gimple_assign_lhs (stmt
);
3952 else if (is_gimple_call (stmt
))
3953 lhs
= gimple_call_lhs (stmt
);
3957 if (TREE_CODE (lhs
) != SSA_NAME
)
3959 decl
= SSA_NAME_VAR (lhs
);
3960 if (TREE_CODE (decl
) != PARM_DECL
)
3963 adj
= get_adjustment_for_base (adjustments
, decl
);
3967 repl
= get_replaced_param_substitute (adj
);
3968 name
= make_ssa_name (repl
, stmt
);
3972 fprintf (dump_file
, "replacing an SSA name of a removed param ");
3973 print_generic_expr (dump_file
, lhs
, 0);
3974 fprintf (dump_file
, " with ");
3975 print_generic_expr (dump_file
, name
, 0);
3976 fprintf (dump_file
, "\n");
3979 if (is_gimple_assign (stmt
))
3980 gimple_assign_set_lhs (stmt
, name
);
3981 else if (is_gimple_call (stmt
))
3982 gimple_call_set_lhs (stmt
, name
);
3984 gimple_phi_set_result (stmt
, name
);
3986 replace_uses_by (lhs
, name
);
3987 release_ssa_name (lhs
);
3991 /* If the expression *EXPR should be replaced by a reduction of a parameter, do
3992 so. ADJUSTMENTS is a pointer to a vector of adjustments. CONVERT
3993 specifies whether the function should care about type incompatibility the
3994 current and new expressions. If it is false, the function will leave
3995 incompatibility issues to the caller. Return true iff the expression
3999 sra_ipa_modify_expr (tree
*expr
, bool convert
,
4000 ipa_parm_adjustment_vec adjustments
)
4003 struct ipa_parm_adjustment
*adj
, *cand
= NULL
;
4004 HOST_WIDE_INT offset
, size
, max_size
;
4007 len
= VEC_length (ipa_parm_adjustment_t
, adjustments
);
4009 if (TREE_CODE (*expr
) == BIT_FIELD_REF
4010 || TREE_CODE (*expr
) == IMAGPART_EXPR
4011 || TREE_CODE (*expr
) == REALPART_EXPR
)
4013 expr
= &TREE_OPERAND (*expr
, 0);
4017 base
= get_ref_base_and_extent (*expr
, &offset
, &size
, &max_size
);
4018 if (!base
|| size
== -1 || max_size
== -1)
4021 if (TREE_CODE (base
) == MEM_REF
)
4023 offset
+= mem_ref_offset (base
).low
* BITS_PER_UNIT
;
4024 base
= TREE_OPERAND (base
, 0);
4027 base
= get_ssa_base_param (base
);
4028 if (!base
|| TREE_CODE (base
) != PARM_DECL
)
4031 for (i
= 0; i
< len
; i
++)
4033 adj
= VEC_index (ipa_parm_adjustment_t
, adjustments
, i
);
4035 if (adj
->base
== base
&&
4036 (adj
->offset
== offset
|| adj
->remove_param
))
4042 if (!cand
|| cand
->copy_param
|| cand
->remove_param
)
4046 src
= build_simple_mem_ref (cand
->reduction
);
4048 src
= cand
->reduction
;
4050 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4052 fprintf (dump_file
, "About to replace expr ");
4053 print_generic_expr (dump_file
, *expr
, 0);
4054 fprintf (dump_file
, " with ");
4055 print_generic_expr (dump_file
, src
, 0);
4056 fprintf (dump_file
, "\n");
4059 if (convert
&& !useless_type_conversion_p (TREE_TYPE (*expr
), cand
->type
))
4061 tree vce
= build1 (VIEW_CONVERT_EXPR
, TREE_TYPE (*expr
), src
);
4069 /* If the statement pointed to by STMT_PTR contains any expressions that need
4070 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4071 potential type incompatibilities (GSI is used to accommodate conversion
4072 statements and must point to the statement). Return true iff the statement
4076 sra_ipa_modify_assign (gimple
*stmt_ptr
, gimple_stmt_iterator
*gsi
,
4077 ipa_parm_adjustment_vec adjustments
)
4079 gimple stmt
= *stmt_ptr
;
4080 tree
*lhs_p
, *rhs_p
;
4083 if (!gimple_assign_single_p (stmt
))
4086 rhs_p
= gimple_assign_rhs1_ptr (stmt
);
4087 lhs_p
= gimple_assign_lhs_ptr (stmt
);
4089 any
= sra_ipa_modify_expr (rhs_p
, false, adjustments
);
4090 any
|= sra_ipa_modify_expr (lhs_p
, false, adjustments
);
4093 tree new_rhs
= NULL_TREE
;
4095 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p
), TREE_TYPE (*rhs_p
)))
4097 if (TREE_CODE (*rhs_p
) == CONSTRUCTOR
)
4099 /* V_C_Es of constructors can cause trouble (PR 42714). */
4100 if (is_gimple_reg_type (TREE_TYPE (*lhs_p
)))
4101 *rhs_p
= fold_convert (TREE_TYPE (*lhs_p
), integer_zero_node
);
4103 *rhs_p
= build_constructor (TREE_TYPE (*lhs_p
), 0);
4106 new_rhs
= fold_build1_loc (gimple_location (stmt
),
4107 VIEW_CONVERT_EXPR
, TREE_TYPE (*lhs_p
),
4110 else if (REFERENCE_CLASS_P (*rhs_p
)
4111 && is_gimple_reg_type (TREE_TYPE (*lhs_p
))
4112 && !is_gimple_reg (*lhs_p
))
4113 /* This can happen when an assignment in between two single field
4114 structures is turned into an assignment in between two pointers to
4115 scalars (PR 42237). */
4120 tree tmp
= force_gimple_operand_gsi (gsi
, new_rhs
, true, NULL_TREE
,
4121 true, GSI_SAME_STMT
);
4123 gimple_assign_set_rhs_from_tree (gsi
, tmp
);
4132 /* Traverse the function body and all modifications as described in
4133 ADJUSTMENTS. Return true iff the CFG has been changed. */
4136 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments
)
4138 bool cfg_changed
= false;
4143 gimple_stmt_iterator gsi
;
4145 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4146 replace_removed_params_ssa_names (gsi_stmt (gsi
), adjustments
);
4148 gsi
= gsi_start_bb (bb
);
4149 while (!gsi_end_p (gsi
))
4151 gimple stmt
= gsi_stmt (gsi
);
4152 bool modified
= false;
4156 switch (gimple_code (stmt
))
4159 t
= gimple_return_retval_ptr (stmt
);
4160 if (*t
!= NULL_TREE
)
4161 modified
|= sra_ipa_modify_expr (t
, true, adjustments
);
4165 modified
|= sra_ipa_modify_assign (&stmt
, &gsi
, adjustments
);
4166 modified
|= replace_removed_params_ssa_names (stmt
, adjustments
);
4170 /* Operands must be processed before the lhs. */
4171 for (i
= 0; i
< gimple_call_num_args (stmt
); i
++)
4173 t
= gimple_call_arg_ptr (stmt
, i
);
4174 modified
|= sra_ipa_modify_expr (t
, true, adjustments
);
4177 if (gimple_call_lhs (stmt
))
4179 t
= gimple_call_lhs_ptr (stmt
);
4180 modified
|= sra_ipa_modify_expr (t
, false, adjustments
);
4181 modified
|= replace_removed_params_ssa_names (stmt
,
4187 for (i
= 0; i
< gimple_asm_ninputs (stmt
); i
++)
4189 t
= &TREE_VALUE (gimple_asm_input_op (stmt
, i
));
4190 modified
|= sra_ipa_modify_expr (t
, true, adjustments
);
4192 for (i
= 0; i
< gimple_asm_noutputs (stmt
); i
++)
4194 t
= &TREE_VALUE (gimple_asm_output_op (stmt
, i
));
4195 modified
|= sra_ipa_modify_expr (t
, false, adjustments
);
4206 if (maybe_clean_eh_stmt (stmt
)
4207 && gimple_purge_dead_eh_edges (gimple_bb (stmt
)))
4217 /* Call gimple_debug_bind_reset_value on all debug statements describing
4218 gimple register parameters that are being removed or replaced. */
4221 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments
)
4225 len
= VEC_length (ipa_parm_adjustment_t
, adjustments
);
4226 for (i
= 0; i
< len
; i
++)
4228 struct ipa_parm_adjustment
*adj
;
4229 imm_use_iterator ui
;
4233 adj
= VEC_index (ipa_parm_adjustment_t
, adjustments
, i
);
4234 if (adj
->copy_param
|| !is_gimple_reg (adj
->base
))
4236 name
= gimple_default_def (cfun
, adj
->base
);
4239 FOR_EACH_IMM_USE_STMT (stmt
, ui
, name
)
4241 /* All other users must have been removed by
4242 ipa_sra_modify_function_body. */
4243 gcc_assert (is_gimple_debug (stmt
));
4244 gimple_debug_bind_reset_value (stmt
);
4250 /* Return true iff all callers have at least as many actual arguments as there
4251 are formal parameters in the current function. */
4254 all_callers_have_enough_arguments_p (struct cgraph_node
*node
)
4256 struct cgraph_edge
*cs
;
4257 for (cs
= node
->callers
; cs
; cs
= cs
->next_caller
)
4258 if (!callsite_has_enough_arguments_p (cs
->call_stmt
))
4265 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4268 convert_callers (struct cgraph_node
*node
, tree old_decl
,
4269 ipa_parm_adjustment_vec adjustments
)
4271 tree old_cur_fndecl
= current_function_decl
;
4272 struct cgraph_edge
*cs
;
4273 basic_block this_block
;
4274 bitmap recomputed_callers
= BITMAP_ALLOC (NULL
);
4276 for (cs
= node
->callers
; cs
; cs
= cs
->next_caller
)
4278 current_function_decl
= cs
->caller
->decl
;
4279 push_cfun (DECL_STRUCT_FUNCTION (cs
->caller
->decl
));
4282 fprintf (dump_file
, "Adjusting call (%i -> %i) %s -> %s\n",
4283 cs
->caller
->uid
, cs
->callee
->uid
,
4284 cgraph_node_name (cs
->caller
),
4285 cgraph_node_name (cs
->callee
));
4287 ipa_modify_call_arguments (cs
, cs
->call_stmt
, adjustments
);
4292 for (cs
= node
->callers
; cs
; cs
= cs
->next_caller
)
4293 if (bitmap_set_bit (recomputed_callers
, cs
->caller
->uid
))
4294 compute_inline_parameters (cs
->caller
);
4295 BITMAP_FREE (recomputed_callers
);
4297 current_function_decl
= old_cur_fndecl
;
4299 if (!encountered_recursive_call
)
4302 FOR_EACH_BB (this_block
)
4304 gimple_stmt_iterator gsi
;
4306 for (gsi
= gsi_start_bb (this_block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4308 gimple stmt
= gsi_stmt (gsi
);
4310 if (gimple_code (stmt
) != GIMPLE_CALL
)
4312 call_fndecl
= gimple_call_fndecl (stmt
);
4313 if (call_fndecl
== old_decl
)
4316 fprintf (dump_file
, "Adjusting recursive call");
4317 gimple_call_set_fndecl (stmt
, node
->decl
);
4318 ipa_modify_call_arguments (NULL
, stmt
, adjustments
);
4326 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4327 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4330 modify_function (struct cgraph_node
*node
, ipa_parm_adjustment_vec adjustments
)
4332 struct cgraph_node
*new_node
;
4333 struct cgraph_edge
*cs
;
4335 VEC (cgraph_edge_p
, heap
) * redirect_callers
;
4339 for (cs
= node
->callers
; cs
!= NULL
; cs
= cs
->next_caller
)
4341 redirect_callers
= VEC_alloc (cgraph_edge_p
, heap
, node_callers
);
4342 for (cs
= node
->callers
; cs
!= NULL
; cs
= cs
->next_caller
)
4343 VEC_quick_push (cgraph_edge_p
, redirect_callers
, cs
);
4345 rebuild_cgraph_edges ();
4347 current_function_decl
= NULL_TREE
;
4349 new_node
= cgraph_function_versioning (node
, redirect_callers
, NULL
, NULL
,
4350 NULL
, NULL
, "isra");
4351 current_function_decl
= new_node
->decl
;
4352 push_cfun (DECL_STRUCT_FUNCTION (new_node
->decl
));
4354 ipa_modify_formal_parameters (current_function_decl
, adjustments
, "ISRA");
4355 cfg_changed
= ipa_sra_modify_function_body (adjustments
);
4356 sra_ipa_reset_debug_stmts (adjustments
);
4357 convert_callers (new_node
, node
->decl
, adjustments
);
4358 cgraph_make_node_local (new_node
);
4362 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4363 attributes, return true otherwise. NODE is the cgraph node of the current
4367 ipa_sra_preliminary_function_checks (struct cgraph_node
*node
)
4369 if (!cgraph_node_can_be_local_p (node
))
4372 fprintf (dump_file
, "Function not local to this compilation unit.\n");
4376 if (!tree_versionable_function_p (node
->decl
))
4379 fprintf (dump_file
, "Function is not versionable.\n");
4383 if (DECL_VIRTUAL_P (current_function_decl
))
4386 fprintf (dump_file
, "Function is a virtual method.\n");
4390 if ((DECL_COMDAT (node
->decl
) || DECL_EXTERNAL (node
->decl
))
4391 && node
->global
.size
>= MAX_INLINE_INSNS_AUTO
)
4394 fprintf (dump_file
, "Function too big to be made truly local.\n");
4402 "Function has no callers in this compilation unit.\n");
4409 fprintf (dump_file
, "Function uses stdarg. \n");
4413 if (TYPE_ATTRIBUTES (TREE_TYPE (node
->decl
)))
4419 /* Perform early interprocedural SRA. */
4422 ipa_early_sra (void)
4424 struct cgraph_node
*node
= cgraph_node (current_function_decl
);
4425 ipa_parm_adjustment_vec adjustments
;
4428 if (!ipa_sra_preliminary_function_checks (node
))
4432 sra_mode
= SRA_MODE_EARLY_IPA
;
4434 if (!find_param_candidates ())
4437 fprintf (dump_file
, "Function has no IPA-SRA candidates.\n");
4441 if (!all_callers_have_enough_arguments_p (node
))
4444 fprintf (dump_file
, "There are callers with insufficient number of "
4449 bb_dereferences
= XCNEWVEC (HOST_WIDE_INT
,
4451 * last_basic_block_for_function (cfun
));
4452 final_bbs
= BITMAP_ALLOC (NULL
);
4455 if (encountered_apply_args
)
4458 fprintf (dump_file
, "Function calls __builtin_apply_args().\n");
4462 if (encountered_unchangable_recursive_call
)
4465 fprintf (dump_file
, "Function calls itself with insufficient "
4466 "number of arguments.\n");
4470 adjustments
= analyze_all_param_acesses ();
4474 ipa_dump_param_adjustments (dump_file
, adjustments
, current_function_decl
);
4476 if (modify_function (node
, adjustments
))
4477 ret
= TODO_update_ssa
| TODO_cleanup_cfg
;
4479 ret
= TODO_update_ssa
;
4480 VEC_free (ipa_parm_adjustment_t
, heap
, adjustments
);
4482 statistics_counter_event (cfun
, "Unused parameters deleted",
4483 sra_stats
.deleted_unused_parameters
);
4484 statistics_counter_event (cfun
, "Scalar parameters converted to by-value",
4485 sra_stats
.scalar_by_ref_to_by_val
);
4486 statistics_counter_event (cfun
, "Aggregate parameters broken up",
4487 sra_stats
.aggregate_params_reduced
);
4488 statistics_counter_event (cfun
, "Aggregate parameter components created",
4489 sra_stats
.param_reductions_created
);
4492 BITMAP_FREE (final_bbs
);
4493 free (bb_dereferences
);
4495 sra_deinitialize ();
4499 /* Return if early ipa sra shall be performed. */
4501 ipa_early_sra_gate (void)
4503 return flag_ipa_sra
&& dbg_cnt (eipa_sra
);
4506 struct gimple_opt_pass pass_early_ipa_sra
=
4510 "eipa_sra", /* name */
4511 ipa_early_sra_gate
, /* gate */
4512 ipa_early_sra
, /* execute */
4515 0, /* static_pass_number */
4516 TV_IPA_SRA
, /* tv_id */
4517 0, /* properties_required */
4518 0, /* properties_provided */
4519 0, /* properties_destroyed */
4520 0, /* todo_flags_start */
4521 TODO_dump_func
| TODO_dump_cgraph
/* todo_flags_finish */