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"
82 #include "tree-flow.h"
84 #include "tree-pretty-print.h"
85 #include "statistics.h"
86 #include "tree-dump.h"
92 #include "tree-inline.h"
93 #include "gimple-pretty-print.h"
94 #include "ipa-inline.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 an access to a non-addressable field? */
178 unsigned non_addressable
: 1;
180 /* Is this access currently in the work queue? */
181 unsigned grp_queued
: 1;
183 /* Does this group contain a write access? This flag is propagated down the
185 unsigned grp_write
: 1;
187 /* Does this group contain a read access? This flag is propagated down the
189 unsigned grp_read
: 1;
191 /* Does this group contain a read access that comes from an assignment
192 statement? This flag is propagated down the access tree. */
193 unsigned grp_assignment_read
: 1;
195 /* Does this group contain a write access that comes from an assignment
196 statement? This flag is propagated down the access tree. */
197 unsigned grp_assignment_write
: 1;
199 /* Does this group contain a read access through a scalar type? This flag is
200 not propagated in the access tree in any direction. */
201 unsigned grp_scalar_read
: 1;
203 /* Does this group contain a write access through a scalar type? This flag
204 is not propagated in the access tree in any direction. */
205 unsigned grp_scalar_write
: 1;
207 /* Other passes of the analysis use this bit to make function
208 analyze_access_subtree create scalar replacements for this group if
210 unsigned grp_hint
: 1;
212 /* Is the subtree rooted in this access fully covered by scalar
214 unsigned grp_covered
: 1;
216 /* If set to true, this access and all below it in an access tree must not be
218 unsigned grp_unscalarizable_region
: 1;
220 /* Whether data have been written to parts of the aggregate covered by this
221 access which is not to be scalarized. This flag is propagated up in the
223 unsigned grp_unscalarized_data
: 1;
225 /* Does this access and/or group contain a write access through a
227 unsigned grp_partial_lhs
: 1;
229 /* Set when a scalar replacement should be created for this variable. We do
230 the decision and creation at different places because create_tmp_var
231 cannot be called from within FOR_EACH_REFERENCED_VAR. */
232 unsigned grp_to_be_replaced
: 1;
234 /* Should TREE_NO_WARNING of a replacement be set? */
235 unsigned grp_no_warning
: 1;
237 /* Is it possible that the group refers to data which might be (directly or
238 otherwise) modified? */
239 unsigned grp_maybe_modified
: 1;
241 /* Set when this is a representative of a pointer to scalar (i.e. by
242 reference) parameter which we consider for turning into a plain scalar
243 (i.e. a by value parameter). */
244 unsigned grp_scalar_ptr
: 1;
246 /* Set when we discover that this pointer is not safe to dereference in the
248 unsigned grp_not_necessarilly_dereferenced
: 1;
251 typedef struct access
*access_p
;
253 DEF_VEC_P (access_p
);
254 DEF_VEC_ALLOC_P (access_p
, heap
);
256 /* Alloc pool for allocating access structures. */
257 static alloc_pool access_pool
;
259 /* A structure linking lhs and rhs accesses from an aggregate assignment. They
260 are used to propagate subaccesses from rhs to lhs as long as they don't
261 conflict with what is already there. */
264 struct access
*lacc
, *racc
;
265 struct assign_link
*next
;
268 /* Alloc pool for allocating assign link structures. */
269 static alloc_pool link_pool
;
271 /* Base (tree) -> Vector (VEC(access_p,heap) *) map. */
272 static struct pointer_map_t
*base_access_vec
;
274 /* Bitmap of candidates. */
275 static bitmap candidate_bitmap
;
277 /* Bitmap of candidates which we should try to entirely scalarize away and
278 those which cannot be (because they are and need be used as a whole). */
279 static bitmap should_scalarize_away_bitmap
, cannot_scalarize_away_bitmap
;
281 /* Obstack for creation of fancy names. */
282 static struct obstack name_obstack
;
284 /* Head of a linked list of accesses that need to have its subaccesses
285 propagated to their assignment counterparts. */
286 static struct access
*work_queue_head
;
288 /* Number of parameters of the analyzed function when doing early ipa SRA. */
289 static int func_param_count
;
291 /* scan_function sets the following to true if it encounters a call to
292 __builtin_apply_args. */
293 static bool encountered_apply_args
;
295 /* Set by scan_function when it finds a recursive call. */
296 static bool encountered_recursive_call
;
298 /* Set by scan_function when it finds a recursive call with less actual
299 arguments than formal parameters.. */
300 static bool encountered_unchangable_recursive_call
;
302 /* This is a table in which for each basic block and parameter there is a
303 distance (offset + size) in that parameter which is dereferenced and
304 accessed in that BB. */
305 static HOST_WIDE_INT
*bb_dereferences
;
306 /* Bitmap of BBs that can cause the function to "stop" progressing by
307 returning, throwing externally, looping infinitely or calling a function
308 which might abort etc.. */
309 static bitmap final_bbs
;
311 /* Representative of no accesses at all. */
312 static struct access no_accesses_representant
;
314 /* Predicate to test the special value. */
317 no_accesses_p (struct access
*access
)
319 return access
== &no_accesses_representant
;
322 /* Dump contents of ACCESS to file F in a human friendly way. If GRP is true,
323 representative fields are dumped, otherwise those which only describe the
324 individual access are. */
328 /* Number of processed aggregates is readily available in
329 analyze_all_variable_accesses and so is not stored here. */
331 /* Number of created scalar replacements. */
334 /* Number of times sra_modify_expr or sra_modify_assign themselves changed an
338 /* Number of statements created by generate_subtree_copies. */
341 /* Number of statements created by load_assign_lhs_subreplacements. */
344 /* Number of times sra_modify_assign has deleted a statement. */
347 /* Number of times sra_modify_assign has to deal with subaccesses of LHS and
348 RHS reparately due to type conversions or nonexistent matching
350 int separate_lhs_rhs_handling
;
352 /* Number of parameters that were removed because they were unused. */
353 int deleted_unused_parameters
;
355 /* Number of scalars passed as parameters by reference that have been
356 converted to be passed by value. */
357 int scalar_by_ref_to_by_val
;
359 /* Number of aggregate parameters that were replaced by one or more of their
361 int aggregate_params_reduced
;
363 /* Numbber of components created when splitting aggregate parameters. */
364 int param_reductions_created
;
368 dump_access (FILE *f
, struct access
*access
, bool grp
)
370 fprintf (f
, "access { ");
371 fprintf (f
, "base = (%d)'", DECL_UID (access
->base
));
372 print_generic_expr (f
, access
->base
, 0);
373 fprintf (f
, "', offset = " HOST_WIDE_INT_PRINT_DEC
, access
->offset
);
374 fprintf (f
, ", size = " HOST_WIDE_INT_PRINT_DEC
, access
->size
);
375 fprintf (f
, ", expr = ");
376 print_generic_expr (f
, access
->expr
, 0);
377 fprintf (f
, ", type = ");
378 print_generic_expr (f
, access
->type
, 0);
380 fprintf (f
, ", total_scalarization = %d, grp_read = %d, grp_write = %d, "
381 "grp_assignment_read = %d, grp_assignment_write = %d, "
382 "grp_scalar_read = %d, grp_scalar_write = %d, "
383 "grp_hint = %d, grp_covered = %d, "
384 "grp_unscalarizable_region = %d, grp_unscalarized_data = %d, "
385 "grp_partial_lhs = %d, grp_to_be_replaced = %d, "
386 "grp_maybe_modified = %d, "
387 "grp_not_necessarilly_dereferenced = %d\n",
388 access
->total_scalarization
, access
->grp_read
, access
->grp_write
,
389 access
->grp_assignment_read
, access
->grp_assignment_write
,
390 access
->grp_scalar_read
, access
->grp_scalar_write
,
391 access
->grp_hint
, access
->grp_covered
,
392 access
->grp_unscalarizable_region
, access
->grp_unscalarized_data
,
393 access
->grp_partial_lhs
, access
->grp_to_be_replaced
,
394 access
->grp_maybe_modified
,
395 access
->grp_not_necessarilly_dereferenced
);
397 fprintf (f
, ", write = %d, total_scalarization = %d, "
398 "grp_partial_lhs = %d\n",
399 access
->write
, access
->total_scalarization
,
400 access
->grp_partial_lhs
);
403 /* Dump a subtree rooted in ACCESS to file F, indent by LEVEL. */
406 dump_access_tree_1 (FILE *f
, struct access
*access
, int level
)
412 for (i
= 0; i
< level
; i
++)
413 fputs ("* ", dump_file
);
415 dump_access (f
, access
, true);
417 if (access
->first_child
)
418 dump_access_tree_1 (f
, access
->first_child
, level
+ 1);
420 access
= access
->next_sibling
;
425 /* Dump all access trees for a variable, given the pointer to the first root in
429 dump_access_tree (FILE *f
, struct access
*access
)
431 for (; access
; access
= access
->next_grp
)
432 dump_access_tree_1 (f
, access
, 0);
435 /* Return true iff ACC is non-NULL and has subaccesses. */
438 access_has_children_p (struct access
*acc
)
440 return acc
&& acc
->first_child
;
443 /* Return a vector of pointers to accesses for the variable given in BASE or
444 NULL if there is none. */
446 static VEC (access_p
, heap
) *
447 get_base_access_vector (tree base
)
451 slot
= pointer_map_contains (base_access_vec
, base
);
455 return *(VEC (access_p
, heap
) **) slot
;
458 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
459 in ACCESS. Return NULL if it cannot be found. */
461 static struct access
*
462 find_access_in_subtree (struct access
*access
, HOST_WIDE_INT offset
,
465 while (access
&& (access
->offset
!= offset
|| access
->size
!= size
))
467 struct access
*child
= access
->first_child
;
469 while (child
&& (child
->offset
+ child
->size
<= offset
))
470 child
= child
->next_sibling
;
477 /* Return the first group representative for DECL or NULL if none exists. */
479 static struct access
*
480 get_first_repr_for_decl (tree base
)
482 VEC (access_p
, heap
) *access_vec
;
484 access_vec
= get_base_access_vector (base
);
488 return VEC_index (access_p
, access_vec
, 0);
491 /* Find an access representative for the variable BASE and given OFFSET and
492 SIZE. Requires that access trees have already been built. Return NULL if
493 it cannot be found. */
495 static struct access
*
496 get_var_base_offset_size_access (tree base
, HOST_WIDE_INT offset
,
499 struct access
*access
;
501 access
= get_first_repr_for_decl (base
);
502 while (access
&& (access
->offset
+ access
->size
<= offset
))
503 access
= access
->next_grp
;
507 return find_access_in_subtree (access
, offset
, size
);
510 /* Add LINK to the linked list of assign links of RACC. */
512 add_link_to_rhs (struct access
*racc
, struct assign_link
*link
)
514 gcc_assert (link
->racc
== racc
);
516 if (!racc
->first_link
)
518 gcc_assert (!racc
->last_link
);
519 racc
->first_link
= link
;
522 racc
->last_link
->next
= link
;
524 racc
->last_link
= link
;
528 /* Move all link structures in their linked list in OLD_RACC to the linked list
531 relink_to_new_repr (struct access
*new_racc
, struct access
*old_racc
)
533 if (!old_racc
->first_link
)
535 gcc_assert (!old_racc
->last_link
);
539 if (new_racc
->first_link
)
541 gcc_assert (!new_racc
->last_link
->next
);
542 gcc_assert (!old_racc
->last_link
|| !old_racc
->last_link
->next
);
544 new_racc
->last_link
->next
= old_racc
->first_link
;
545 new_racc
->last_link
= old_racc
->last_link
;
549 gcc_assert (!new_racc
->last_link
);
551 new_racc
->first_link
= old_racc
->first_link
;
552 new_racc
->last_link
= old_racc
->last_link
;
554 old_racc
->first_link
= old_racc
->last_link
= NULL
;
557 /* Add ACCESS to the work queue (which is actually a stack). */
560 add_access_to_work_queue (struct access
*access
)
562 if (!access
->grp_queued
)
564 gcc_assert (!access
->next_queued
);
565 access
->next_queued
= work_queue_head
;
566 access
->grp_queued
= 1;
567 work_queue_head
= access
;
571 /* Pop an access from the work queue, and return it, assuming there is one. */
573 static struct access
*
574 pop_access_from_work_queue (void)
576 struct access
*access
= work_queue_head
;
578 work_queue_head
= access
->next_queued
;
579 access
->next_queued
= NULL
;
580 access
->grp_queued
= 0;
585 /* Allocate necessary structures. */
588 sra_initialize (void)
590 candidate_bitmap
= BITMAP_ALLOC (NULL
);
591 should_scalarize_away_bitmap
= BITMAP_ALLOC (NULL
);
592 cannot_scalarize_away_bitmap
= BITMAP_ALLOC (NULL
);
593 gcc_obstack_init (&name_obstack
);
594 access_pool
= create_alloc_pool ("SRA accesses", sizeof (struct access
), 16);
595 link_pool
= create_alloc_pool ("SRA links", sizeof (struct assign_link
), 16);
596 base_access_vec
= pointer_map_create ();
597 memset (&sra_stats
, 0, sizeof (sra_stats
));
598 encountered_apply_args
= false;
599 encountered_recursive_call
= false;
600 encountered_unchangable_recursive_call
= false;
603 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
606 delete_base_accesses (const void *key ATTRIBUTE_UNUSED
, void **value
,
607 void *data ATTRIBUTE_UNUSED
)
609 VEC (access_p
, heap
) *access_vec
;
610 access_vec
= (VEC (access_p
, heap
) *) *value
;
611 VEC_free (access_p
, heap
, access_vec
);
616 /* Deallocate all general structures. */
619 sra_deinitialize (void)
621 BITMAP_FREE (candidate_bitmap
);
622 BITMAP_FREE (should_scalarize_away_bitmap
);
623 BITMAP_FREE (cannot_scalarize_away_bitmap
);
624 free_alloc_pool (access_pool
);
625 free_alloc_pool (link_pool
);
626 obstack_free (&name_obstack
, NULL
);
628 pointer_map_traverse (base_access_vec
, delete_base_accesses
, NULL
);
629 pointer_map_destroy (base_access_vec
);
632 /* Remove DECL from candidates for SRA and write REASON to the dump file if
635 disqualify_candidate (tree decl
, const char *reason
)
637 bitmap_clear_bit (candidate_bitmap
, DECL_UID (decl
));
639 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
641 fprintf (dump_file
, "! Disqualifying ");
642 print_generic_expr (dump_file
, decl
, 0);
643 fprintf (dump_file
, " - %s\n", reason
);
647 /* Return true iff the type contains a field or an element which does not allow
651 type_internals_preclude_sra_p (tree type
)
656 switch (TREE_CODE (type
))
660 case QUAL_UNION_TYPE
:
661 for (fld
= TYPE_FIELDS (type
); fld
; fld
= DECL_CHAIN (fld
))
662 if (TREE_CODE (fld
) == FIELD_DECL
)
664 tree ft
= TREE_TYPE (fld
);
666 if (TREE_THIS_VOLATILE (fld
)
667 || !DECL_FIELD_OFFSET (fld
) || !DECL_SIZE (fld
)
668 || !host_integerp (DECL_FIELD_OFFSET (fld
), 1)
669 || !host_integerp (DECL_SIZE (fld
), 1)
670 || (AGGREGATE_TYPE_P (ft
)
671 && int_bit_position (fld
) % BITS_PER_UNIT
!= 0))
674 if (AGGREGATE_TYPE_P (ft
)
675 && type_internals_preclude_sra_p (ft
))
682 et
= TREE_TYPE (type
);
684 if (AGGREGATE_TYPE_P (et
))
685 return type_internals_preclude_sra_p (et
);
694 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
695 base variable if it is. Return T if it is not an SSA_NAME. */
698 get_ssa_base_param (tree t
)
700 if (TREE_CODE (t
) == SSA_NAME
)
702 if (SSA_NAME_IS_DEFAULT_DEF (t
))
703 return SSA_NAME_VAR (t
);
710 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
711 belongs to, unless the BB has already been marked as a potentially
715 mark_parm_dereference (tree base
, HOST_WIDE_INT dist
, gimple stmt
)
717 basic_block bb
= gimple_bb (stmt
);
718 int idx
, parm_index
= 0;
721 if (bitmap_bit_p (final_bbs
, bb
->index
))
724 for (parm
= DECL_ARGUMENTS (current_function_decl
);
725 parm
&& parm
!= base
;
726 parm
= DECL_CHAIN (parm
))
729 gcc_assert (parm_index
< func_param_count
);
731 idx
= bb
->index
* func_param_count
+ parm_index
;
732 if (bb_dereferences
[idx
] < dist
)
733 bb_dereferences
[idx
] = dist
;
736 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
737 the three fields. Also add it to the vector of accesses corresponding to
738 the base. Finally, return the new access. */
740 static struct access
*
741 create_access_1 (tree base
, HOST_WIDE_INT offset
, HOST_WIDE_INT size
)
743 VEC (access_p
, heap
) *vec
;
744 struct access
*access
;
747 access
= (struct access
*) pool_alloc (access_pool
);
748 memset (access
, 0, sizeof (struct access
));
750 access
->offset
= offset
;
753 slot
= pointer_map_contains (base_access_vec
, base
);
755 vec
= (VEC (access_p
, heap
) *) *slot
;
757 vec
= VEC_alloc (access_p
, heap
, 32);
759 VEC_safe_push (access_p
, heap
, vec
, access
);
761 *((struct VEC (access_p
,heap
) **)
762 pointer_map_insert (base_access_vec
, base
)) = vec
;
767 /* Create and insert access for EXPR. Return created access, or NULL if it is
770 static struct access
*
771 create_access (tree expr
, gimple stmt
, bool write
)
773 struct access
*access
;
774 HOST_WIDE_INT offset
, size
, max_size
;
776 bool ptr
, unscalarizable_region
= false;
778 base
= get_ref_base_and_extent (expr
, &offset
, &size
, &max_size
);
780 if (sra_mode
== SRA_MODE_EARLY_IPA
781 && TREE_CODE (base
) == MEM_REF
)
783 base
= get_ssa_base_param (TREE_OPERAND (base
, 0));
791 if (!DECL_P (base
) || !bitmap_bit_p (candidate_bitmap
, DECL_UID (base
)))
794 if (sra_mode
== SRA_MODE_EARLY_IPA
)
796 if (size
< 0 || size
!= max_size
)
798 disqualify_candidate (base
, "Encountered a variable sized access.");
801 if (TREE_CODE (expr
) == COMPONENT_REF
802 && DECL_BIT_FIELD (TREE_OPERAND (expr
, 1)))
804 disqualify_candidate (base
, "Encountered a bit-field access.");
807 gcc_checking_assert ((offset
% BITS_PER_UNIT
) == 0);
810 mark_parm_dereference (base
, offset
+ size
, stmt
);
814 if (size
!= max_size
)
817 unscalarizable_region
= true;
821 disqualify_candidate (base
, "Encountered an unconstrained access.");
826 access
= create_access_1 (base
, offset
, size
);
828 access
->type
= TREE_TYPE (expr
);
829 access
->write
= write
;
830 access
->grp_unscalarizable_region
= unscalarizable_region
;
833 if (TREE_CODE (expr
) == COMPONENT_REF
834 && DECL_NONADDRESSABLE_P (TREE_OPERAND (expr
, 1)))
835 access
->non_addressable
= 1;
841 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
842 register types or (recursively) records with only these two kinds of fields.
843 It also returns false if any of these records contains a bit-field. */
846 type_consists_of_records_p (tree type
)
850 if (TREE_CODE (type
) != RECORD_TYPE
)
853 for (fld
= TYPE_FIELDS (type
); fld
; fld
= DECL_CHAIN (fld
))
854 if (TREE_CODE (fld
) == FIELD_DECL
)
856 tree ft
= TREE_TYPE (fld
);
858 if (DECL_BIT_FIELD (fld
))
861 if (!is_gimple_reg_type (ft
)
862 && !type_consists_of_records_p (ft
))
869 /* Create total_scalarization accesses for all scalar type fields in DECL that
870 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
871 must be the top-most VAR_DECL representing the variable, OFFSET must be the
872 offset of DECL within BASE. REF must be the memory reference expression for
876 completely_scalarize_record (tree base
, tree decl
, HOST_WIDE_INT offset
,
879 tree fld
, decl_type
= TREE_TYPE (decl
);
881 for (fld
= TYPE_FIELDS (decl_type
); fld
; fld
= DECL_CHAIN (fld
))
882 if (TREE_CODE (fld
) == FIELD_DECL
)
884 HOST_WIDE_INT pos
= offset
+ int_bit_position (fld
);
885 tree ft
= TREE_TYPE (fld
);
886 tree nref
= build3 (COMPONENT_REF
, TREE_TYPE (fld
), ref
, fld
,
889 if (is_gimple_reg_type (ft
))
891 struct access
*access
;
894 size
= tree_low_cst (DECL_SIZE (fld
), 1);
895 access
= create_access_1 (base
, pos
, size
);
898 access
->total_scalarization
= 1;
899 /* Accesses for intraprocedural SRA can have their stmt NULL. */
902 completely_scalarize_record (base
, fld
, pos
, nref
);
907 /* Search the given tree for a declaration by skipping handled components and
908 exclude it from the candidates. */
911 disqualify_base_of_expr (tree t
, const char *reason
)
913 t
= get_base_address (t
);
914 if (sra_mode
== SRA_MODE_EARLY_IPA
915 && TREE_CODE (t
) == MEM_REF
)
916 t
= get_ssa_base_param (TREE_OPERAND (t
, 0));
919 disqualify_candidate (t
, reason
);
922 /* Scan expression EXPR and create access structures for all accesses to
923 candidates for scalarization. Return the created access or NULL if none is
926 static struct access
*
927 build_access_from_expr_1 (tree expr
, gimple stmt
, bool write
)
929 struct access
*ret
= NULL
;
932 if (TREE_CODE (expr
) == BIT_FIELD_REF
933 || TREE_CODE (expr
) == IMAGPART_EXPR
934 || TREE_CODE (expr
) == REALPART_EXPR
)
936 expr
= TREE_OPERAND (expr
, 0);
942 /* We need to dive through V_C_Es in order to get the size of its parameter
943 and not the result type. Ada produces such statements. We are also
944 capable of handling the topmost V_C_E but not any of those buried in other
945 handled components. */
946 if (TREE_CODE (expr
) == VIEW_CONVERT_EXPR
)
947 expr
= TREE_OPERAND (expr
, 0);
949 if (contains_view_convert_expr_p (expr
))
951 disqualify_base_of_expr (expr
, "V_C_E under a different handled "
956 switch (TREE_CODE (expr
))
959 if (TREE_CODE (TREE_OPERAND (expr
, 0)) != ADDR_EXPR
960 && sra_mode
!= SRA_MODE_EARLY_IPA
)
968 case ARRAY_RANGE_REF
:
969 ret
= create_access (expr
, stmt
, write
);
976 if (write
&& partial_ref
&& ret
)
977 ret
->grp_partial_lhs
= 1;
982 /* Scan expression EXPR and create access structures for all accesses to
983 candidates for scalarization. Return true if any access has been inserted.
984 STMT must be the statement from which the expression is taken, WRITE must be
985 true if the expression is a store and false otherwise. */
988 build_access_from_expr (tree expr
, gimple stmt
, bool write
)
990 struct access
*access
;
992 access
= build_access_from_expr_1 (expr
, stmt
, write
);
995 /* This means the aggregate is accesses as a whole in a way other than an
996 assign statement and thus cannot be removed even if we had a scalar
997 replacement for everything. */
998 if (cannot_scalarize_away_bitmap
)
999 bitmap_set_bit (cannot_scalarize_away_bitmap
, DECL_UID (access
->base
));
1005 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
1006 modes in which it matters, return true iff they have been disqualified. RHS
1007 may be NULL, in that case ignore it. If we scalarize an aggregate in
1008 intra-SRA we may need to add statements after each statement. This is not
1009 possible if a statement unconditionally has to end the basic block. */
1011 disqualify_ops_if_throwing_stmt (gimple stmt
, tree lhs
, tree rhs
)
1013 if ((sra_mode
== SRA_MODE_EARLY_INTRA
|| sra_mode
== SRA_MODE_INTRA
)
1014 && (stmt_can_throw_internal (stmt
) || stmt_ends_bb_p (stmt
)))
1016 disqualify_base_of_expr (lhs
, "LHS of a throwing stmt.");
1018 disqualify_base_of_expr (rhs
, "RHS of a throwing stmt.");
1024 /* Scan expressions occuring in STMT, create access structures for all accesses
1025 to candidates for scalarization and remove those candidates which occur in
1026 statements or expressions that prevent them from being split apart. Return
1027 true if any access has been inserted. */
1030 build_accesses_from_assign (gimple stmt
)
1033 struct access
*lacc
, *racc
;
1035 if (!gimple_assign_single_p (stmt
))
1038 lhs
= gimple_assign_lhs (stmt
);
1039 rhs
= gimple_assign_rhs1 (stmt
);
1041 if (disqualify_ops_if_throwing_stmt (stmt
, lhs
, rhs
))
1044 racc
= build_access_from_expr_1 (rhs
, stmt
, false);
1045 lacc
= build_access_from_expr_1 (lhs
, stmt
, true);
1048 lacc
->grp_assignment_write
= 1;
1052 racc
->grp_assignment_read
= 1;
1053 if (should_scalarize_away_bitmap
&& !gimple_has_volatile_ops (stmt
)
1054 && !is_gimple_reg_type (racc
->type
))
1055 bitmap_set_bit (should_scalarize_away_bitmap
, DECL_UID (racc
->base
));
1059 && (sra_mode
== SRA_MODE_EARLY_INTRA
|| sra_mode
== SRA_MODE_INTRA
)
1060 && !lacc
->grp_unscalarizable_region
1061 && !racc
->grp_unscalarizable_region
1062 && AGGREGATE_TYPE_P (TREE_TYPE (lhs
))
1063 /* FIXME: Turn the following line into an assert after PR 40058 is
1065 && lacc
->size
== racc
->size
1066 && useless_type_conversion_p (lacc
->type
, racc
->type
))
1068 struct assign_link
*link
;
1070 link
= (struct assign_link
*) pool_alloc (link_pool
);
1071 memset (link
, 0, sizeof (struct assign_link
));
1076 add_link_to_rhs (racc
, link
);
1079 return lacc
|| racc
;
1082 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1083 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1086 asm_visit_addr (gimple stmt ATTRIBUTE_UNUSED
, tree op
,
1087 void *data ATTRIBUTE_UNUSED
)
1089 op
= get_base_address (op
);
1092 disqualify_candidate (op
, "Non-scalarizable GIMPLE_ASM operand.");
1097 /* Return true iff callsite CALL has at least as many actual arguments as there
1098 are formal parameters of the function currently processed by IPA-SRA. */
1101 callsite_has_enough_arguments_p (gimple call
)
1103 return gimple_call_num_args (call
) >= (unsigned) func_param_count
;
1106 /* Scan function and look for interesting expressions and create access
1107 structures for them. Return true iff any access is created. */
1110 scan_function (void)
1117 gimple_stmt_iterator gsi
;
1118 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1120 gimple stmt
= gsi_stmt (gsi
);
1124 if (final_bbs
&& stmt_can_throw_external (stmt
))
1125 bitmap_set_bit (final_bbs
, bb
->index
);
1126 switch (gimple_code (stmt
))
1129 t
= gimple_return_retval (stmt
);
1131 ret
|= build_access_from_expr (t
, stmt
, false);
1133 bitmap_set_bit (final_bbs
, bb
->index
);
1137 ret
|= build_accesses_from_assign (stmt
);
1141 for (i
= 0; i
< gimple_call_num_args (stmt
); i
++)
1142 ret
|= build_access_from_expr (gimple_call_arg (stmt
, i
),
1145 if (sra_mode
== SRA_MODE_EARLY_IPA
)
1147 tree dest
= gimple_call_fndecl (stmt
);
1148 int flags
= gimple_call_flags (stmt
);
1152 if (DECL_BUILT_IN_CLASS (dest
) == BUILT_IN_NORMAL
1153 && DECL_FUNCTION_CODE (dest
) == BUILT_IN_APPLY_ARGS
)
1154 encountered_apply_args
= true;
1155 if (cgraph_get_node (dest
)
1156 == cgraph_get_node (current_function_decl
))
1158 encountered_recursive_call
= true;
1159 if (!callsite_has_enough_arguments_p (stmt
))
1160 encountered_unchangable_recursive_call
= true;
1165 && (flags
& (ECF_CONST
| ECF_PURE
)) == 0)
1166 bitmap_set_bit (final_bbs
, bb
->index
);
1169 t
= gimple_call_lhs (stmt
);
1170 if (t
&& !disqualify_ops_if_throwing_stmt (stmt
, t
, NULL
))
1171 ret
|= build_access_from_expr (t
, stmt
, true);
1175 walk_stmt_load_store_addr_ops (stmt
, NULL
, NULL
, NULL
,
1178 bitmap_set_bit (final_bbs
, bb
->index
);
1180 for (i
= 0; i
< gimple_asm_ninputs (stmt
); i
++)
1182 t
= TREE_VALUE (gimple_asm_input_op (stmt
, i
));
1183 ret
|= build_access_from_expr (t
, stmt
, false);
1185 for (i
= 0; i
< gimple_asm_noutputs (stmt
); i
++)
1187 t
= TREE_VALUE (gimple_asm_output_op (stmt
, i
));
1188 ret
|= build_access_from_expr (t
, stmt
, true);
1201 /* Helper of QSORT function. There are pointers to accesses in the array. An
1202 access is considered smaller than another if it has smaller offset or if the
1203 offsets are the same but is size is bigger. */
1206 compare_access_positions (const void *a
, const void *b
)
1208 const access_p
*fp1
= (const access_p
*) a
;
1209 const access_p
*fp2
= (const access_p
*) b
;
1210 const access_p f1
= *fp1
;
1211 const access_p f2
= *fp2
;
1213 if (f1
->offset
!= f2
->offset
)
1214 return f1
->offset
< f2
->offset
? -1 : 1;
1216 if (f1
->size
== f2
->size
)
1218 if (f1
->type
== f2
->type
)
1220 /* Put any non-aggregate type before any aggregate type. */
1221 else if (!is_gimple_reg_type (f1
->type
)
1222 && is_gimple_reg_type (f2
->type
))
1224 else if (is_gimple_reg_type (f1
->type
)
1225 && !is_gimple_reg_type (f2
->type
))
1227 /* Put any complex or vector type before any other scalar type. */
1228 else if (TREE_CODE (f1
->type
) != COMPLEX_TYPE
1229 && TREE_CODE (f1
->type
) != VECTOR_TYPE
1230 && (TREE_CODE (f2
->type
) == COMPLEX_TYPE
1231 || TREE_CODE (f2
->type
) == VECTOR_TYPE
))
1233 else if ((TREE_CODE (f1
->type
) == COMPLEX_TYPE
1234 || TREE_CODE (f1
->type
) == VECTOR_TYPE
)
1235 && TREE_CODE (f2
->type
) != COMPLEX_TYPE
1236 && TREE_CODE (f2
->type
) != VECTOR_TYPE
)
1238 /* Put the integral type with the bigger precision first. */
1239 else if (INTEGRAL_TYPE_P (f1
->type
)
1240 && INTEGRAL_TYPE_P (f2
->type
))
1241 return TYPE_PRECISION (f2
->type
) - TYPE_PRECISION (f1
->type
);
1242 /* Put any integral type with non-full precision last. */
1243 else if (INTEGRAL_TYPE_P (f1
->type
)
1244 && (TREE_INT_CST_LOW (TYPE_SIZE (f1
->type
))
1245 != TYPE_PRECISION (f1
->type
)))
1247 else if (INTEGRAL_TYPE_P (f2
->type
)
1248 && (TREE_INT_CST_LOW (TYPE_SIZE (f2
->type
))
1249 != TYPE_PRECISION (f2
->type
)))
1251 /* Stabilize the sort. */
1252 return TYPE_UID (f1
->type
) - TYPE_UID (f2
->type
);
1255 /* We want the bigger accesses first, thus the opposite operator in the next
1257 return f1
->size
> f2
->size
? -1 : 1;
1261 /* Append a name of the declaration to the name obstack. A helper function for
1265 make_fancy_decl_name (tree decl
)
1269 tree name
= DECL_NAME (decl
);
1271 obstack_grow (&name_obstack
, IDENTIFIER_POINTER (name
),
1272 IDENTIFIER_LENGTH (name
));
1275 sprintf (buffer
, "D%u", DECL_UID (decl
));
1276 obstack_grow (&name_obstack
, buffer
, strlen (buffer
));
1280 /* Helper for make_fancy_name. */
1283 make_fancy_name_1 (tree expr
)
1290 make_fancy_decl_name (expr
);
1294 switch (TREE_CODE (expr
))
1297 make_fancy_name_1 (TREE_OPERAND (expr
, 0));
1298 obstack_1grow (&name_obstack
, '$');
1299 make_fancy_decl_name (TREE_OPERAND (expr
, 1));
1303 make_fancy_name_1 (TREE_OPERAND (expr
, 0));
1304 obstack_1grow (&name_obstack
, '$');
1305 /* Arrays with only one element may not have a constant as their
1307 index
= TREE_OPERAND (expr
, 1);
1308 if (TREE_CODE (index
) != INTEGER_CST
)
1310 sprintf (buffer
, HOST_WIDE_INT_PRINT_DEC
, TREE_INT_CST_LOW (index
));
1311 obstack_grow (&name_obstack
, buffer
, strlen (buffer
));
1315 make_fancy_name_1 (TREE_OPERAND (expr
, 0));
1319 make_fancy_name_1 (TREE_OPERAND (expr
, 0));
1320 if (!integer_zerop (TREE_OPERAND (expr
, 1)))
1322 obstack_1grow (&name_obstack
, '$');
1323 sprintf (buffer
, HOST_WIDE_INT_PRINT_DEC
,
1324 TREE_INT_CST_LOW (TREE_OPERAND (expr
, 1)));
1325 obstack_grow (&name_obstack
, buffer
, strlen (buffer
));
1332 gcc_unreachable (); /* we treat these as scalars. */
1339 /* Create a human readable name for replacement variable of ACCESS. */
1342 make_fancy_name (tree expr
)
1344 make_fancy_name_1 (expr
);
1345 obstack_1grow (&name_obstack
, '\0');
1346 return XOBFINISH (&name_obstack
, char *);
1349 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1350 EXP_TYPE at the given OFFSET. If BASE is something for which
1351 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1352 to insert new statements either before or below the current one as specified
1353 by INSERT_AFTER. This function is not capable of handling bitfields. */
1356 build_ref_for_offset (location_t loc
, tree base
, HOST_WIDE_INT offset
,
1357 tree exp_type
, gimple_stmt_iterator
*gsi
,
1360 tree prev_base
= base
;
1362 HOST_WIDE_INT base_offset
;
1364 gcc_checking_assert (offset
% BITS_PER_UNIT
== 0);
1366 base
= get_addr_base_and_unit_offset (base
, &base_offset
);
1368 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1369 offset such as array[var_index]. */
1375 gcc_checking_assert (gsi
);
1376 tmp
= create_tmp_reg (build_pointer_type (TREE_TYPE (prev_base
)), NULL
);
1377 add_referenced_var (tmp
);
1378 tmp
= make_ssa_name (tmp
, NULL
);
1379 addr
= build_fold_addr_expr (unshare_expr (prev_base
));
1380 STRIP_USELESS_TYPE_CONVERSION (addr
);
1381 stmt
= gimple_build_assign (tmp
, addr
);
1382 gimple_set_location (stmt
, loc
);
1383 SSA_NAME_DEF_STMT (tmp
) = stmt
;
1385 gsi_insert_after (gsi
, stmt
, GSI_NEW_STMT
);
1387 gsi_insert_before (gsi
, stmt
, GSI_SAME_STMT
);
1390 off
= build_int_cst (reference_alias_ptr_type (prev_base
),
1391 offset
/ BITS_PER_UNIT
);
1394 else if (TREE_CODE (base
) == MEM_REF
)
1396 off
= build_int_cst (TREE_TYPE (TREE_OPERAND (base
, 1)),
1397 base_offset
+ offset
/ BITS_PER_UNIT
);
1398 off
= int_const_binop (PLUS_EXPR
, TREE_OPERAND (base
, 1), off
);
1399 base
= unshare_expr (TREE_OPERAND (base
, 0));
1403 off
= build_int_cst (reference_alias_ptr_type (base
),
1404 base_offset
+ offset
/ BITS_PER_UNIT
);
1405 base
= build_fold_addr_expr (unshare_expr (base
));
1408 return fold_build2_loc (loc
, MEM_REF
, exp_type
, base
, off
);
1411 /* Construct a memory reference to a part of an aggregate BASE at the given
1412 OFFSET and of the same type as MODEL. In case this is a reference to a
1413 component, the function will replicate the last COMPONENT_REF of model's
1414 expr to access it. GSI and INSERT_AFTER have the same meaning as in
1415 build_ref_for_offset. */
1418 build_ref_for_model (location_t loc
, tree base
, HOST_WIDE_INT offset
,
1419 struct access
*model
, gimple_stmt_iterator
*gsi
,
1422 if (TREE_CODE (model
->expr
) == COMPONENT_REF
)
1425 offset
-= int_bit_position (TREE_OPERAND (model
->expr
, 1));
1426 exp_type
= TREE_TYPE (TREE_OPERAND (model
->expr
, 0));
1427 t
= build_ref_for_offset (loc
, base
, offset
, exp_type
, gsi
, insert_after
);
1428 return fold_build3_loc (loc
, COMPONENT_REF
, model
->type
, t
,
1429 TREE_OPERAND (model
->expr
, 1), NULL_TREE
);
1432 return build_ref_for_offset (loc
, base
, offset
, model
->type
,
1436 /* Construct a memory reference consisting of component_refs and array_refs to
1437 a part of an aggregate *RES (which is of type TYPE). The requested part
1438 should have type EXP_TYPE at be the given OFFSET. This function might not
1439 succeed, it returns true when it does and only then *RES points to something
1440 meaningful. This function should be used only to build expressions that we
1441 might need to present to user (e.g. in warnings). In all other situations,
1442 build_ref_for_model or build_ref_for_offset should be used instead. */
1445 build_user_friendly_ref_for_offset (tree
*res
, tree type
, HOST_WIDE_INT offset
,
1451 tree tr_size
, index
, minidx
;
1452 HOST_WIDE_INT el_size
;
1454 if (offset
== 0 && exp_type
1455 && types_compatible_p (exp_type
, type
))
1458 switch (TREE_CODE (type
))
1461 case QUAL_UNION_TYPE
:
1463 for (fld
= TYPE_FIELDS (type
); fld
; fld
= DECL_CHAIN (fld
))
1465 HOST_WIDE_INT pos
, size
;
1466 tree expr
, *expr_ptr
;
1468 if (TREE_CODE (fld
) != FIELD_DECL
)
1471 pos
= int_bit_position (fld
);
1472 gcc_assert (TREE_CODE (type
) == RECORD_TYPE
|| pos
== 0);
1473 tr_size
= DECL_SIZE (fld
);
1474 if (!tr_size
|| !host_integerp (tr_size
, 1))
1476 size
= tree_low_cst (tr_size
, 1);
1482 else if (pos
> offset
|| (pos
+ size
) <= offset
)
1485 expr
= build3 (COMPONENT_REF
, TREE_TYPE (fld
), *res
, fld
,
1488 if (build_user_friendly_ref_for_offset (expr_ptr
, TREE_TYPE (fld
),
1489 offset
- pos
, exp_type
))
1498 tr_size
= TYPE_SIZE (TREE_TYPE (type
));
1499 if (!tr_size
|| !host_integerp (tr_size
, 1))
1501 el_size
= tree_low_cst (tr_size
, 1);
1503 minidx
= TYPE_MIN_VALUE (TYPE_DOMAIN (type
));
1504 if (TREE_CODE (minidx
) != INTEGER_CST
|| el_size
== 0)
1506 index
= build_int_cst (TYPE_DOMAIN (type
), offset
/ el_size
);
1507 if (!integer_zerop (minidx
))
1508 index
= int_const_binop (PLUS_EXPR
, index
, minidx
);
1509 *res
= build4 (ARRAY_REF
, TREE_TYPE (type
), *res
, index
,
1510 NULL_TREE
, NULL_TREE
);
1511 offset
= offset
% el_size
;
1512 type
= TREE_TYPE (type
);
1527 /* Return true iff TYPE is stdarg va_list type. */
1530 is_va_list_type (tree type
)
1532 return TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (va_list_type_node
);
1535 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1536 those with type which is suitable for scalarization. */
1539 find_var_candidates (void)
1542 referenced_var_iterator rvi
;
1545 FOR_EACH_REFERENCED_VAR (cfun
, var
, rvi
)
1547 if (TREE_CODE (var
) != VAR_DECL
&& TREE_CODE (var
) != PARM_DECL
)
1549 type
= TREE_TYPE (var
);
1551 if (!AGGREGATE_TYPE_P (type
)
1552 || needs_to_live_in_memory (var
)
1553 || TREE_THIS_VOLATILE (var
)
1554 || !COMPLETE_TYPE_P (type
)
1555 || !host_integerp (TYPE_SIZE (type
), 1)
1556 || tree_low_cst (TYPE_SIZE (type
), 1) == 0
1557 || type_internals_preclude_sra_p (type
)
1558 /* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1559 we also want to schedule it rather late. Thus we ignore it in
1561 || (sra_mode
== SRA_MODE_EARLY_INTRA
1562 && is_va_list_type (type
)))
1565 bitmap_set_bit (candidate_bitmap
, DECL_UID (var
));
1567 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1569 fprintf (dump_file
, "Candidate (%d): ", DECL_UID (var
));
1570 print_generic_expr (dump_file
, var
, 0);
1571 fprintf (dump_file
, "\n");
1579 /* Sort all accesses for the given variable, check for partial overlaps and
1580 return NULL if there are any. If there are none, pick a representative for
1581 each combination of offset and size and create a linked list out of them.
1582 Return the pointer to the first representative and make sure it is the first
1583 one in the vector of accesses. */
1585 static struct access
*
1586 sort_and_splice_var_accesses (tree var
)
1588 int i
, j
, access_count
;
1589 struct access
*res
, **prev_acc_ptr
= &res
;
1590 VEC (access_p
, heap
) *access_vec
;
1592 HOST_WIDE_INT low
= -1, high
= 0;
1594 access_vec
= get_base_access_vector (var
);
1597 access_count
= VEC_length (access_p
, access_vec
);
1599 /* Sort by <OFFSET, SIZE>. */
1600 VEC_qsort (access_p
, access_vec
, compare_access_positions
);
1603 while (i
< access_count
)
1605 struct access
*access
= VEC_index (access_p
, access_vec
, i
);
1606 bool grp_write
= access
->write
;
1607 bool grp_read
= !access
->write
;
1608 bool grp_scalar_write
= access
->write
1609 && is_gimple_reg_type (access
->type
);
1610 bool grp_scalar_read
= !access
->write
1611 && is_gimple_reg_type (access
->type
);
1612 bool grp_assignment_read
= access
->grp_assignment_read
;
1613 bool grp_assignment_write
= access
->grp_assignment_write
;
1614 bool multiple_scalar_reads
= false;
1615 bool total_scalarization
= access
->total_scalarization
;
1616 bool grp_partial_lhs
= access
->grp_partial_lhs
;
1617 bool first_scalar
= is_gimple_reg_type (access
->type
);
1618 bool unscalarizable_region
= access
->grp_unscalarizable_region
;
1620 if (first
|| access
->offset
>= high
)
1623 low
= access
->offset
;
1624 high
= access
->offset
+ access
->size
;
1626 else if (access
->offset
> low
&& access
->offset
+ access
->size
> high
)
1629 gcc_assert (access
->offset
>= low
1630 && access
->offset
+ access
->size
<= high
);
1633 while (j
< access_count
)
1635 struct access
*ac2
= VEC_index (access_p
, access_vec
, j
);
1636 if (ac2
->offset
!= access
->offset
|| ac2
->size
!= access
->size
)
1641 grp_scalar_write
= (grp_scalar_write
1642 || is_gimple_reg_type (ac2
->type
));
1647 if (is_gimple_reg_type (ac2
->type
))
1649 if (grp_scalar_read
)
1650 multiple_scalar_reads
= true;
1652 grp_scalar_read
= true;
1655 grp_assignment_read
|= ac2
->grp_assignment_read
;
1656 grp_assignment_write
|= ac2
->grp_assignment_write
;
1657 grp_partial_lhs
|= ac2
->grp_partial_lhs
;
1658 unscalarizable_region
|= ac2
->grp_unscalarizable_region
;
1659 total_scalarization
|= ac2
->total_scalarization
;
1660 relink_to_new_repr (access
, ac2
);
1662 /* If there are both aggregate-type and scalar-type accesses with
1663 this combination of size and offset, the comparison function
1664 should have put the scalars first. */
1665 gcc_assert (first_scalar
|| !is_gimple_reg_type (ac2
->type
));
1666 ac2
->group_representative
= access
;
1672 access
->group_representative
= access
;
1673 access
->grp_write
= grp_write
;
1674 access
->grp_read
= grp_read
;
1675 access
->grp_scalar_read
= grp_scalar_read
;
1676 access
->grp_scalar_write
= grp_scalar_write
;
1677 access
->grp_assignment_read
= grp_assignment_read
;
1678 access
->grp_assignment_write
= grp_assignment_write
;
1679 access
->grp_hint
= multiple_scalar_reads
|| total_scalarization
;
1680 access
->grp_partial_lhs
= grp_partial_lhs
;
1681 access
->grp_unscalarizable_region
= unscalarizable_region
;
1682 if (access
->first_link
)
1683 add_access_to_work_queue (access
);
1685 *prev_acc_ptr
= access
;
1686 prev_acc_ptr
= &access
->next_grp
;
1689 gcc_assert (res
== VEC_index (access_p
, access_vec
, 0));
1693 /* Create a variable for the given ACCESS which determines the type, name and a
1694 few other properties. Return the variable declaration and store it also to
1695 ACCESS->replacement. */
1698 create_access_replacement (struct access
*access
, bool rename
)
1702 repl
= create_tmp_var (access
->type
, "SR");
1704 add_referenced_var (repl
);
1706 mark_sym_for_renaming (repl
);
1708 if (!access
->grp_partial_lhs
1709 && (TREE_CODE (access
->type
) == COMPLEX_TYPE
1710 || TREE_CODE (access
->type
) == VECTOR_TYPE
))
1711 DECL_GIMPLE_REG_P (repl
) = 1;
1713 DECL_SOURCE_LOCATION (repl
) = DECL_SOURCE_LOCATION (access
->base
);
1714 DECL_ARTIFICIAL (repl
) = 1;
1715 DECL_IGNORED_P (repl
) = DECL_IGNORED_P (access
->base
);
1717 if (DECL_NAME (access
->base
)
1718 && !DECL_IGNORED_P (access
->base
)
1719 && !DECL_ARTIFICIAL (access
->base
))
1721 char *pretty_name
= make_fancy_name (access
->expr
);
1722 tree debug_expr
= unshare_expr (access
->expr
), d
;
1724 DECL_NAME (repl
) = get_identifier (pretty_name
);
1725 obstack_free (&name_obstack
, pretty_name
);
1727 /* Get rid of any SSA_NAMEs embedded in debug_expr,
1728 as DECL_DEBUG_EXPR isn't considered when looking for still
1729 used SSA_NAMEs and thus they could be freed. All debug info
1730 generation cares is whether something is constant or variable
1731 and that get_ref_base_and_extent works properly on the
1733 for (d
= debug_expr
; handled_component_p (d
); d
= TREE_OPERAND (d
, 0))
1734 switch (TREE_CODE (d
))
1737 case ARRAY_RANGE_REF
:
1738 if (TREE_OPERAND (d
, 1)
1739 && TREE_CODE (TREE_OPERAND (d
, 1)) == SSA_NAME
)
1740 TREE_OPERAND (d
, 1) = SSA_NAME_VAR (TREE_OPERAND (d
, 1));
1741 if (TREE_OPERAND (d
, 3)
1742 && TREE_CODE (TREE_OPERAND (d
, 3)) == SSA_NAME
)
1743 TREE_OPERAND (d
, 3) = SSA_NAME_VAR (TREE_OPERAND (d
, 3));
1746 if (TREE_OPERAND (d
, 2)
1747 && TREE_CODE (TREE_OPERAND (d
, 2)) == SSA_NAME
)
1748 TREE_OPERAND (d
, 2) = SSA_NAME_VAR (TREE_OPERAND (d
, 2));
1753 SET_DECL_DEBUG_EXPR (repl
, debug_expr
);
1754 DECL_DEBUG_EXPR_IS_FROM (repl
) = 1;
1755 if (access
->grp_no_warning
)
1756 TREE_NO_WARNING (repl
) = 1;
1758 TREE_NO_WARNING (repl
) = TREE_NO_WARNING (access
->base
);
1761 TREE_NO_WARNING (repl
) = 1;
1765 fprintf (dump_file
, "Created a replacement for ");
1766 print_generic_expr (dump_file
, access
->base
, 0);
1767 fprintf (dump_file
, " offset: %u, size: %u: ",
1768 (unsigned) access
->offset
, (unsigned) access
->size
);
1769 print_generic_expr (dump_file
, repl
, 0);
1770 fprintf (dump_file
, "\n");
1772 sra_stats
.replacements
++;
1777 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
1780 get_access_replacement (struct access
*access
)
1782 gcc_assert (access
->grp_to_be_replaced
);
1784 if (!access
->replacement_decl
)
1785 access
->replacement_decl
= create_access_replacement (access
, true);
1786 return access
->replacement_decl
;
1789 /* Return ACCESS scalar replacement, create it if it does not exist yet but do
1790 not mark it for renaming. */
1793 get_unrenamed_access_replacement (struct access
*access
)
1795 gcc_assert (!access
->grp_to_be_replaced
);
1797 if (!access
->replacement_decl
)
1798 access
->replacement_decl
= create_access_replacement (access
, false);
1799 return access
->replacement_decl
;
1803 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
1804 linked list along the way. Stop when *ACCESS is NULL or the access pointed
1805 to it is not "within" the root. Return false iff some accesses partially
1809 build_access_subtree (struct access
**access
)
1811 struct access
*root
= *access
, *last_child
= NULL
;
1812 HOST_WIDE_INT limit
= root
->offset
+ root
->size
;
1814 *access
= (*access
)->next_grp
;
1815 while (*access
&& (*access
)->offset
+ (*access
)->size
<= limit
)
1818 root
->first_child
= *access
;
1820 last_child
->next_sibling
= *access
;
1821 last_child
= *access
;
1823 if (!build_access_subtree (access
))
1827 if (*access
&& (*access
)->offset
< limit
)
1833 /* Build a tree of access representatives, ACCESS is the pointer to the first
1834 one, others are linked in a list by the next_grp field. Return false iff
1835 some accesses partially overlap. */
1838 build_access_trees (struct access
*access
)
1842 struct access
*root
= access
;
1844 if (!build_access_subtree (&access
))
1846 root
->next_grp
= access
;
1851 /* Return true if expr contains some ARRAY_REFs into a variable bounded
1855 expr_with_var_bounded_array_refs_p (tree expr
)
1857 while (handled_component_p (expr
))
1859 if (TREE_CODE (expr
) == ARRAY_REF
1860 && !host_integerp (array_ref_low_bound (expr
), 0))
1862 expr
= TREE_OPERAND (expr
, 0);
1867 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
1868 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
1869 sorts of access flags appropriately along the way, notably always set
1870 grp_read and grp_assign_read according to MARK_READ and grp_write when
1873 Creating a replacement for a scalar access is considered beneficial if its
1874 grp_hint is set (this means we are either attempting total scalarization or
1875 there is more than one direct read access) or according to the following
1878 Access written to through a scalar type (once or more times)
1880 | Written to in an assignment statement
1882 | | Access read as scalar _once_
1884 | | | Read in an assignment statement
1886 | | | | Scalarize Comment
1887 -----------------------------------------------------------------------------
1888 0 0 0 0 No access for the scalar
1889 0 0 0 1 No access for the scalar
1890 0 0 1 0 No Single read - won't help
1891 0 0 1 1 No The same case
1892 0 1 0 0 No access for the scalar
1893 0 1 0 1 No access for the scalar
1894 0 1 1 0 Yes s = *g; return s.i;
1895 0 1 1 1 Yes The same case as above
1896 1 0 0 0 No Won't help
1897 1 0 0 1 Yes s.i = 1; *g = s;
1898 1 0 1 0 Yes s.i = 5; g = s.i;
1899 1 0 1 1 Yes The same case as above
1900 1 1 0 0 No Won't help.
1901 1 1 0 1 Yes s.i = 1; *g = s;
1902 1 1 1 0 Yes s = *g; return s.i;
1903 1 1 1 1 Yes Any of the above yeses */
1906 analyze_access_subtree (struct access
*root
, struct access
*parent
,
1907 bool allow_replacements
)
1909 struct access
*child
;
1910 HOST_WIDE_INT limit
= root
->offset
+ root
->size
;
1911 HOST_WIDE_INT covered_to
= root
->offset
;
1912 bool scalar
= is_gimple_reg_type (root
->type
);
1913 bool hole
= false, sth_created
= false;
1917 if (parent
->grp_read
)
1919 if (parent
->grp_assignment_read
)
1920 root
->grp_assignment_read
= 1;
1921 if (parent
->grp_write
)
1922 root
->grp_write
= 1;
1923 if (parent
->grp_assignment_write
)
1924 root
->grp_assignment_write
= 1;
1927 if (root
->grp_unscalarizable_region
)
1928 allow_replacements
= false;
1930 if (allow_replacements
&& expr_with_var_bounded_array_refs_p (root
->expr
))
1931 allow_replacements
= false;
1933 for (child
= root
->first_child
; child
; child
= child
->next_sibling
)
1935 if (!hole
&& child
->offset
< covered_to
)
1938 covered_to
+= child
->size
;
1940 sth_created
|= analyze_access_subtree (child
, root
,
1941 allow_replacements
&& !scalar
);
1943 root
->grp_unscalarized_data
|= child
->grp_unscalarized_data
;
1944 hole
|= !child
->grp_covered
;
1947 if (allow_replacements
&& scalar
&& !root
->first_child
1949 || ((root
->grp_scalar_read
|| root
->grp_assignment_read
)
1950 && (root
->grp_scalar_write
|| root
->grp_assignment_write
))))
1952 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1954 fprintf (dump_file
, "Marking ");
1955 print_generic_expr (dump_file
, root
->base
, 0);
1956 fprintf (dump_file
, " offset: %u, size: %u: ",
1957 (unsigned) root
->offset
, (unsigned) root
->size
);
1958 fprintf (dump_file
, " to be replaced.\n");
1961 root
->grp_to_be_replaced
= 1;
1965 else if (covered_to
< limit
)
1968 if (sth_created
&& !hole
)
1970 root
->grp_covered
= 1;
1973 if (root
->grp_write
|| TREE_CODE (root
->base
) == PARM_DECL
)
1974 root
->grp_unscalarized_data
= 1; /* not covered and written to */
1980 /* Analyze all access trees linked by next_grp by the means of
1981 analyze_access_subtree. */
1983 analyze_access_trees (struct access
*access
)
1989 if (analyze_access_subtree (access
, NULL
, true))
1991 access
= access
->next_grp
;
1997 /* Return true iff a potential new child of LACC at offset OFFSET and with size
1998 SIZE would conflict with an already existing one. If exactly such a child
1999 already exists in LACC, store a pointer to it in EXACT_MATCH. */
2002 child_would_conflict_in_lacc (struct access
*lacc
, HOST_WIDE_INT norm_offset
,
2003 HOST_WIDE_INT size
, struct access
**exact_match
)
2005 struct access
*child
;
2007 for (child
= lacc
->first_child
; child
; child
= child
->next_sibling
)
2009 if (child
->offset
== norm_offset
&& child
->size
== size
)
2011 *exact_match
= child
;
2015 if (child
->offset
< norm_offset
+ size
2016 && child
->offset
+ child
->size
> norm_offset
)
2023 /* Create a new child access of PARENT, with all properties just like MODEL
2024 except for its offset and with its grp_write false and grp_read true.
2025 Return the new access or NULL if it cannot be created. Note that this access
2026 is created long after all splicing and sorting, it's not located in any
2027 access vector and is automatically a representative of its group. */
2029 static struct access
*
2030 create_artificial_child_access (struct access
*parent
, struct access
*model
,
2031 HOST_WIDE_INT new_offset
)
2033 struct access
*access
;
2034 struct access
**child
;
2035 tree expr
= parent
->base
;
2037 gcc_assert (!model
->grp_unscalarizable_region
);
2039 access
= (struct access
*) pool_alloc (access_pool
);
2040 memset (access
, 0, sizeof (struct access
));
2041 if (!build_user_friendly_ref_for_offset (&expr
, TREE_TYPE (expr
), new_offset
,
2044 access
->grp_no_warning
= true;
2045 expr
= build_ref_for_model (EXPR_LOCATION (parent
->base
), parent
->base
,
2046 new_offset
, model
, NULL
, false);
2049 access
->base
= parent
->base
;
2050 access
->expr
= expr
;
2051 access
->offset
= new_offset
;
2052 access
->size
= model
->size
;
2053 access
->type
= model
->type
;
2054 access
->grp_write
= true;
2055 access
->grp_read
= false;
2057 child
= &parent
->first_child
;
2058 while (*child
&& (*child
)->offset
< new_offset
)
2059 child
= &(*child
)->next_sibling
;
2061 access
->next_sibling
= *child
;
2068 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2069 true if any new subaccess was created. Additionally, if RACC is a scalar
2070 access but LACC is not, change the type of the latter, if possible. */
2073 propagate_subaccesses_across_link (struct access
*lacc
, struct access
*racc
)
2075 struct access
*rchild
;
2076 HOST_WIDE_INT norm_delta
= lacc
->offset
- racc
->offset
;
2079 if (is_gimple_reg_type (lacc
->type
)
2080 || lacc
->grp_unscalarizable_region
2081 || racc
->grp_unscalarizable_region
)
2084 if (!lacc
->first_child
&& !racc
->first_child
2085 && is_gimple_reg_type (racc
->type
))
2087 tree t
= lacc
->base
;
2089 lacc
->type
= racc
->type
;
2090 if (build_user_friendly_ref_for_offset (&t
, TREE_TYPE (t
), lacc
->offset
,
2095 lacc
->expr
= build_ref_for_model (EXPR_LOCATION (lacc
->base
),
2096 lacc
->base
, lacc
->offset
,
2098 lacc
->grp_no_warning
= true;
2103 for (rchild
= racc
->first_child
; rchild
; rchild
= rchild
->next_sibling
)
2105 struct access
*new_acc
= NULL
;
2106 HOST_WIDE_INT norm_offset
= rchild
->offset
+ norm_delta
;
2108 if (rchild
->grp_unscalarizable_region
)
2111 if (child_would_conflict_in_lacc (lacc
, norm_offset
, rchild
->size
,
2116 rchild
->grp_hint
= 1;
2117 new_acc
->grp_hint
|= new_acc
->grp_read
;
2118 if (rchild
->first_child
)
2119 ret
|= propagate_subaccesses_across_link (new_acc
, rchild
);
2124 rchild
->grp_hint
= 1;
2125 new_acc
= create_artificial_child_access (lacc
, rchild
, norm_offset
);
2129 if (racc
->first_child
)
2130 propagate_subaccesses_across_link (new_acc
, rchild
);
2137 /* Propagate all subaccesses across assignment links. */
2140 propagate_all_subaccesses (void)
2142 while (work_queue_head
)
2144 struct access
*racc
= pop_access_from_work_queue ();
2145 struct assign_link
*link
;
2147 gcc_assert (racc
->first_link
);
2149 for (link
= racc
->first_link
; link
; link
= link
->next
)
2151 struct access
*lacc
= link
->lacc
;
2153 if (!bitmap_bit_p (candidate_bitmap
, DECL_UID (lacc
->base
)))
2155 lacc
= lacc
->group_representative
;
2156 if (propagate_subaccesses_across_link (lacc
, racc
)
2157 && lacc
->first_link
)
2158 add_access_to_work_queue (lacc
);
2163 /* Go through all accesses collected throughout the (intraprocedural) analysis
2164 stage, exclude overlapping ones, identify representatives and build trees
2165 out of them, making decisions about scalarization on the way. Return true
2166 iff there are any to-be-scalarized variables after this stage. */
2169 analyze_all_variable_accesses (void)
2172 bitmap tmp
= BITMAP_ALLOC (NULL
);
2174 unsigned i
, max_total_scalarization_size
;
2176 max_total_scalarization_size
= UNITS_PER_WORD
* BITS_PER_UNIT
2177 * MOVE_RATIO (optimize_function_for_speed_p (cfun
));
2179 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap
, 0, i
, bi
)
2180 if (bitmap_bit_p (should_scalarize_away_bitmap
, i
)
2181 && !bitmap_bit_p (cannot_scalarize_away_bitmap
, i
))
2183 tree var
= referenced_var (i
);
2185 if (TREE_CODE (var
) == VAR_DECL
2186 && ((unsigned) tree_low_cst (TYPE_SIZE (TREE_TYPE (var
)), 1)
2187 <= max_total_scalarization_size
)
2188 && type_consists_of_records_p (TREE_TYPE (var
)))
2190 completely_scalarize_record (var
, var
, 0, var
);
2191 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2193 fprintf (dump_file
, "Will attempt to totally scalarize ");
2194 print_generic_expr (dump_file
, var
, 0);
2195 fprintf (dump_file
, " (UID: %u): \n", DECL_UID (var
));
2200 bitmap_copy (tmp
, candidate_bitmap
);
2201 EXECUTE_IF_SET_IN_BITMAP (tmp
, 0, i
, bi
)
2203 tree var
= referenced_var (i
);
2204 struct access
*access
;
2206 access
= sort_and_splice_var_accesses (var
);
2207 if (!access
|| !build_access_trees (access
))
2208 disqualify_candidate (var
,
2209 "No or inhibitingly overlapping accesses.");
2212 propagate_all_subaccesses ();
2214 bitmap_copy (tmp
, candidate_bitmap
);
2215 EXECUTE_IF_SET_IN_BITMAP (tmp
, 0, i
, bi
)
2217 tree var
= referenced_var (i
);
2218 struct access
*access
= get_first_repr_for_decl (var
);
2220 if (analyze_access_trees (access
))
2223 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2225 fprintf (dump_file
, "\nAccess trees for ");
2226 print_generic_expr (dump_file
, var
, 0);
2227 fprintf (dump_file
, " (UID: %u): \n", DECL_UID (var
));
2228 dump_access_tree (dump_file
, access
);
2229 fprintf (dump_file
, "\n");
2233 disqualify_candidate (var
, "No scalar replacements to be created.");
2240 statistics_counter_event (cfun
, "Scalarized aggregates", res
);
2247 /* Generate statements copying scalar replacements of accesses within a subtree
2248 into or out of AGG. ACCESS, all its children, siblings and their children
2249 are to be processed. AGG is an aggregate type expression (can be a
2250 declaration but does not have to be, it can for example also be a mem_ref or
2251 a series of handled components). TOP_OFFSET is the offset of the processed
2252 subtree which has to be subtracted from offsets of individual accesses to
2253 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2254 replacements in the interval <start_offset, start_offset + chunk_size>,
2255 otherwise copy all. GSI is a statement iterator used to place the new
2256 statements. WRITE should be true when the statements should write from AGG
2257 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2258 statements will be added after the current statement in GSI, they will be
2259 added before the statement otherwise. */
2262 generate_subtree_copies (struct access
*access
, tree agg
,
2263 HOST_WIDE_INT top_offset
,
2264 HOST_WIDE_INT start_offset
, HOST_WIDE_INT chunk_size
,
2265 gimple_stmt_iterator
*gsi
, bool write
,
2266 bool insert_after
, location_t loc
)
2270 if (chunk_size
&& access
->offset
>= start_offset
+ chunk_size
)
2273 if (access
->grp_to_be_replaced
2275 || access
->offset
+ access
->size
> start_offset
))
2277 tree expr
, repl
= get_access_replacement (access
);
2280 expr
= build_ref_for_model (loc
, agg
, access
->offset
- top_offset
,
2281 access
, gsi
, insert_after
);
2285 if (access
->grp_partial_lhs
)
2286 expr
= force_gimple_operand_gsi (gsi
, expr
, true, NULL_TREE
,
2288 insert_after
? GSI_NEW_STMT
2290 stmt
= gimple_build_assign (repl
, expr
);
2294 TREE_NO_WARNING (repl
) = 1;
2295 if (access
->grp_partial_lhs
)
2296 repl
= force_gimple_operand_gsi (gsi
, repl
, true, NULL_TREE
,
2298 insert_after
? GSI_NEW_STMT
2300 stmt
= gimple_build_assign (expr
, repl
);
2302 gimple_set_location (stmt
, loc
);
2305 gsi_insert_after (gsi
, stmt
, GSI_NEW_STMT
);
2307 gsi_insert_before (gsi
, stmt
, GSI_SAME_STMT
);
2309 sra_stats
.subtree_copies
++;
2312 if (access
->first_child
)
2313 generate_subtree_copies (access
->first_child
, agg
, top_offset
,
2314 start_offset
, chunk_size
, gsi
,
2315 write
, insert_after
, loc
);
2317 access
= access
->next_sibling
;
2322 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2323 the root of the subtree to be processed. GSI is the statement iterator used
2324 for inserting statements which are added after the current statement if
2325 INSERT_AFTER is true or before it otherwise. */
2328 init_subtree_with_zero (struct access
*access
, gimple_stmt_iterator
*gsi
,
2329 bool insert_after
, location_t loc
)
2332 struct access
*child
;
2334 if (access
->grp_to_be_replaced
)
2338 stmt
= gimple_build_assign (get_access_replacement (access
),
2339 build_zero_cst (access
->type
));
2341 gsi_insert_after (gsi
, stmt
, GSI_NEW_STMT
);
2343 gsi_insert_before (gsi
, stmt
, GSI_SAME_STMT
);
2345 gimple_set_location (stmt
, loc
);
2348 for (child
= access
->first_child
; child
; child
= child
->next_sibling
)
2349 init_subtree_with_zero (child
, gsi
, insert_after
, loc
);
2352 /* Search for an access representative for the given expression EXPR and
2353 return it or NULL if it cannot be found. */
2355 static struct access
*
2356 get_access_for_expr (tree expr
)
2358 HOST_WIDE_INT offset
, size
, max_size
;
2361 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2362 a different size than the size of its argument and we need the latter
2364 if (TREE_CODE (expr
) == VIEW_CONVERT_EXPR
)
2365 expr
= TREE_OPERAND (expr
, 0);
2367 base
= get_ref_base_and_extent (expr
, &offset
, &size
, &max_size
);
2368 if (max_size
== -1 || !DECL_P (base
))
2371 if (!bitmap_bit_p (candidate_bitmap
, DECL_UID (base
)))
2374 return get_var_base_offset_size_access (base
, offset
, max_size
);
2377 /* Replace the expression EXPR with a scalar replacement if there is one and
2378 generate other statements to do type conversion or subtree copying if
2379 necessary. GSI is used to place newly created statements, WRITE is true if
2380 the expression is being written to (it is on a LHS of a statement or output
2381 in an assembly statement). */
2384 sra_modify_expr (tree
*expr
, gimple_stmt_iterator
*gsi
, bool write
)
2387 struct access
*access
;
2390 if (TREE_CODE (*expr
) == BIT_FIELD_REF
)
2393 expr
= &TREE_OPERAND (*expr
, 0);
2398 if (TREE_CODE (*expr
) == REALPART_EXPR
|| TREE_CODE (*expr
) == IMAGPART_EXPR
)
2399 expr
= &TREE_OPERAND (*expr
, 0);
2400 access
= get_access_for_expr (*expr
);
2403 type
= TREE_TYPE (*expr
);
2405 loc
= gimple_location (gsi_stmt (*gsi
));
2406 if (access
->grp_to_be_replaced
)
2408 tree repl
= get_access_replacement (access
);
2409 /* If we replace a non-register typed access simply use the original
2410 access expression to extract the scalar component afterwards.
2411 This happens if scalarizing a function return value or parameter
2412 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2413 gcc.c-torture/compile/20011217-1.c.
2415 We also want to use this when accessing a complex or vector which can
2416 be accessed as a different type too, potentially creating a need for
2417 type conversion (see PR42196) and when scalarized unions are involved
2418 in assembler statements (see PR42398). */
2419 if (!useless_type_conversion_p (type
, access
->type
))
2423 ref
= build_ref_for_model (loc
, access
->base
, access
->offset
, access
,
2430 if (access
->grp_partial_lhs
)
2431 ref
= force_gimple_operand_gsi (gsi
, ref
, true, NULL_TREE
,
2432 false, GSI_NEW_STMT
);
2433 stmt
= gimple_build_assign (repl
, ref
);
2434 gimple_set_location (stmt
, loc
);
2435 gsi_insert_after (gsi
, stmt
, GSI_NEW_STMT
);
2441 if (access
->grp_partial_lhs
)
2442 repl
= force_gimple_operand_gsi (gsi
, repl
, true, NULL_TREE
,
2443 true, GSI_SAME_STMT
);
2444 stmt
= gimple_build_assign (ref
, repl
);
2445 gimple_set_location (stmt
, loc
);
2446 gsi_insert_before (gsi
, stmt
, GSI_SAME_STMT
);
2454 if (access
->first_child
)
2456 HOST_WIDE_INT start_offset
, chunk_size
;
2458 && host_integerp (TREE_OPERAND (bfr
, 1), 1)
2459 && host_integerp (TREE_OPERAND (bfr
, 2), 1))
2461 chunk_size
= tree_low_cst (TREE_OPERAND (bfr
, 1), 1);
2462 start_offset
= access
->offset
2463 + tree_low_cst (TREE_OPERAND (bfr
, 2), 1);
2466 start_offset
= chunk_size
= 0;
2468 generate_subtree_copies (access
->first_child
, access
->base
, 0,
2469 start_offset
, chunk_size
, gsi
, write
, write
,
2475 /* Where scalar replacements of the RHS have been written to when a replacement
2476 of a LHS of an assigments cannot be direclty loaded from a replacement of
2478 enum unscalarized_data_handling
{ SRA_UDH_NONE
, /* Nothing done so far. */
2479 SRA_UDH_RIGHT
, /* Data flushed to the RHS. */
2480 SRA_UDH_LEFT
}; /* Data flushed to the LHS. */
2482 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2483 base aggregate if there are unscalarized data or directly to LHS of the
2484 statement that is pointed to by GSI otherwise. */
2486 static enum unscalarized_data_handling
2487 handle_unscalarized_data_in_subtree (struct access
*top_racc
,
2488 gimple_stmt_iterator
*gsi
)
2490 if (top_racc
->grp_unscalarized_data
)
2492 generate_subtree_copies (top_racc
->first_child
, top_racc
->base
, 0, 0, 0,
2494 gimple_location (gsi_stmt (*gsi
)));
2495 return SRA_UDH_RIGHT
;
2499 tree lhs
= gimple_assign_lhs (gsi_stmt (*gsi
));
2500 generate_subtree_copies (top_racc
->first_child
, lhs
, top_racc
->offset
,
2501 0, 0, gsi
, false, false,
2502 gimple_location (gsi_stmt (*gsi
)));
2503 return SRA_UDH_LEFT
;
2508 /* Try to generate statements to load all sub-replacements in an access subtree
2509 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2510 If that is not possible, refresh the TOP_RACC base aggregate and load the
2511 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2512 copied. NEW_GSI is stmt iterator used for statement insertions after the
2513 original assignment, OLD_GSI is used to insert statements before the
2514 assignment. *REFRESHED keeps the information whether we have needed to
2515 refresh replacements of the LHS and from which side of the assignments this
2519 load_assign_lhs_subreplacements (struct access
*lacc
, struct access
*top_racc
,
2520 HOST_WIDE_INT left_offset
,
2521 gimple_stmt_iterator
*old_gsi
,
2522 gimple_stmt_iterator
*new_gsi
,
2523 enum unscalarized_data_handling
*refreshed
)
2525 location_t loc
= gimple_location (gsi_stmt (*old_gsi
));
2526 for (lacc
= lacc
->first_child
; lacc
; lacc
= lacc
->next_sibling
)
2528 if (lacc
->grp_to_be_replaced
)
2530 struct access
*racc
;
2531 HOST_WIDE_INT offset
= lacc
->offset
- left_offset
+ top_racc
->offset
;
2535 racc
= find_access_in_subtree (top_racc
, offset
, lacc
->size
);
2536 if (racc
&& racc
->grp_to_be_replaced
)
2538 rhs
= get_access_replacement (racc
);
2539 if (!useless_type_conversion_p (lacc
->type
, racc
->type
))
2540 rhs
= fold_build1_loc (loc
, VIEW_CONVERT_EXPR
, lacc
->type
, rhs
);
2544 /* No suitable access on the right hand side, need to load from
2545 the aggregate. See if we have to update it first... */
2546 if (*refreshed
== SRA_UDH_NONE
)
2547 *refreshed
= handle_unscalarized_data_in_subtree (top_racc
,
2550 if (*refreshed
== SRA_UDH_LEFT
)
2551 rhs
= build_ref_for_model (loc
, lacc
->base
, lacc
->offset
, lacc
,
2554 rhs
= build_ref_for_model (loc
, top_racc
->base
, offset
, lacc
,
2558 stmt
= gimple_build_assign (get_access_replacement (lacc
), rhs
);
2559 gsi_insert_after (new_gsi
, stmt
, GSI_NEW_STMT
);
2560 gimple_set_location (stmt
, loc
);
2562 sra_stats
.subreplacements
++;
2564 else if (*refreshed
== SRA_UDH_NONE
2565 && lacc
->grp_read
&& !lacc
->grp_covered
)
2566 *refreshed
= handle_unscalarized_data_in_subtree (top_racc
,
2569 if (lacc
->first_child
)
2570 load_assign_lhs_subreplacements (lacc
, top_racc
, left_offset
,
2571 old_gsi
, new_gsi
, refreshed
);
2575 /* Result code for SRA assignment modification. */
2576 enum assignment_mod_result
{ SRA_AM_NONE
, /* nothing done for the stmt */
2577 SRA_AM_MODIFIED
, /* stmt changed but not
2579 SRA_AM_REMOVED
}; /* stmt eliminated */
2581 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2582 to the assignment and GSI is the statement iterator pointing at it. Returns
2583 the same values as sra_modify_assign. */
2585 static enum assignment_mod_result
2586 sra_modify_constructor_assign (gimple
*stmt
, gimple_stmt_iterator
*gsi
)
2588 tree lhs
= gimple_assign_lhs (*stmt
);
2592 acc
= get_access_for_expr (lhs
);
2596 loc
= gimple_location (*stmt
);
2597 if (VEC_length (constructor_elt
,
2598 CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt
))) > 0)
2600 /* I have never seen this code path trigger but if it can happen the
2601 following should handle it gracefully. */
2602 if (access_has_children_p (acc
))
2603 generate_subtree_copies (acc
->first_child
, acc
->base
, 0, 0, 0, gsi
,
2605 return SRA_AM_MODIFIED
;
2608 if (acc
->grp_covered
)
2610 init_subtree_with_zero (acc
, gsi
, false, loc
);
2611 unlink_stmt_vdef (*stmt
);
2612 gsi_remove (gsi
, true);
2613 return SRA_AM_REMOVED
;
2617 init_subtree_with_zero (acc
, gsi
, true, loc
);
2618 return SRA_AM_MODIFIED
;
2622 /* Create and return a new suitable default definition SSA_NAME for RACC which
2623 is an access describing an uninitialized part of an aggregate that is being
2627 get_repl_default_def_ssa_name (struct access
*racc
)
2631 decl
= get_unrenamed_access_replacement (racc
);
2633 repl
= gimple_default_def (cfun
, decl
);
2636 repl
= make_ssa_name (decl
, gimple_build_nop ());
2637 set_default_def (decl
, repl
);
2643 /* Return true if REF has a COMPONENT_REF with a bit-field field declaration
2647 contains_bitfld_comp_ref_p (const_tree ref
)
2649 while (handled_component_p (ref
))
2651 if (TREE_CODE (ref
) == COMPONENT_REF
2652 && DECL_BIT_FIELD (TREE_OPERAND (ref
, 1)))
2654 ref
= TREE_OPERAND (ref
, 0);
2660 /* Return true if REF has an VIEW_CONVERT_EXPR or a COMPONENT_REF with a
2661 bit-field field declaration somewhere in it. */
2664 contains_vce_or_bfcref_p (const_tree ref
)
2666 while (handled_component_p (ref
))
2668 if (TREE_CODE (ref
) == VIEW_CONVERT_EXPR
2669 || (TREE_CODE (ref
) == COMPONENT_REF
2670 && DECL_BIT_FIELD (TREE_OPERAND (ref
, 1))))
2672 ref
= TREE_OPERAND (ref
, 0);
2678 /* Examine both sides of the assignment statement pointed to by STMT, replace
2679 them with a scalare replacement if there is one and generate copying of
2680 replacements if scalarized aggregates have been used in the assignment. GSI
2681 is used to hold generated statements for type conversions and subtree
2684 static enum assignment_mod_result
2685 sra_modify_assign (gimple
*stmt
, gimple_stmt_iterator
*gsi
)
2687 struct access
*lacc
, *racc
;
2689 bool modify_this_stmt
= false;
2690 bool force_gimple_rhs
= false;
2692 gimple_stmt_iterator orig_gsi
= *gsi
;
2694 if (!gimple_assign_single_p (*stmt
))
2696 lhs
= gimple_assign_lhs (*stmt
);
2697 rhs
= gimple_assign_rhs1 (*stmt
);
2699 if (TREE_CODE (rhs
) == CONSTRUCTOR
)
2700 return sra_modify_constructor_assign (stmt
, gsi
);
2702 if (TREE_CODE (rhs
) == REALPART_EXPR
|| TREE_CODE (lhs
) == REALPART_EXPR
2703 || TREE_CODE (rhs
) == IMAGPART_EXPR
|| TREE_CODE (lhs
) == IMAGPART_EXPR
2704 || TREE_CODE (rhs
) == BIT_FIELD_REF
|| TREE_CODE (lhs
) == BIT_FIELD_REF
)
2706 modify_this_stmt
= sra_modify_expr (gimple_assign_rhs1_ptr (*stmt
),
2708 modify_this_stmt
|= sra_modify_expr (gimple_assign_lhs_ptr (*stmt
),
2710 return modify_this_stmt
? SRA_AM_MODIFIED
: SRA_AM_NONE
;
2713 lacc
= get_access_for_expr (lhs
);
2714 racc
= get_access_for_expr (rhs
);
2718 loc
= gimple_location (*stmt
);
2719 if (lacc
&& lacc
->grp_to_be_replaced
)
2721 lhs
= get_access_replacement (lacc
);
2722 gimple_assign_set_lhs (*stmt
, lhs
);
2723 modify_this_stmt
= true;
2724 if (lacc
->grp_partial_lhs
)
2725 force_gimple_rhs
= true;
2729 if (racc
&& racc
->grp_to_be_replaced
)
2731 rhs
= get_access_replacement (racc
);
2732 modify_this_stmt
= true;
2733 if (racc
->grp_partial_lhs
)
2734 force_gimple_rhs
= true;
2738 if (modify_this_stmt
)
2740 if (!useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (rhs
)))
2742 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
2743 ??? This should move to fold_stmt which we simply should
2744 call after building a VIEW_CONVERT_EXPR here. */
2745 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs
))
2746 && !contains_bitfld_comp_ref_p (lhs
)
2747 && !access_has_children_p (lacc
))
2749 lhs
= build_ref_for_model (loc
, lhs
, 0, racc
, gsi
, false);
2750 gimple_assign_set_lhs (*stmt
, lhs
);
2752 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs
))
2753 && !contains_vce_or_bfcref_p (rhs
)
2754 && !access_has_children_p (racc
))
2755 rhs
= build_ref_for_model (loc
, rhs
, 0, lacc
, gsi
, false);
2757 if (!useless_type_conversion_p (TREE_TYPE (lhs
), TREE_TYPE (rhs
)))
2759 rhs
= fold_build1_loc (loc
, VIEW_CONVERT_EXPR
, TREE_TYPE (lhs
),
2761 if (is_gimple_reg_type (TREE_TYPE (lhs
))
2762 && TREE_CODE (lhs
) != SSA_NAME
)
2763 force_gimple_rhs
= true;
2768 /* From this point on, the function deals with assignments in between
2769 aggregates when at least one has scalar reductions of some of its
2770 components. There are three possible scenarios: Both the LHS and RHS have
2771 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
2773 In the first case, we would like to load the LHS components from RHS
2774 components whenever possible. If that is not possible, we would like to
2775 read it directly from the RHS (after updating it by storing in it its own
2776 components). If there are some necessary unscalarized data in the LHS,
2777 those will be loaded by the original assignment too. If neither of these
2778 cases happen, the original statement can be removed. Most of this is done
2779 by load_assign_lhs_subreplacements.
2781 In the second case, we would like to store all RHS scalarized components
2782 directly into LHS and if they cover the aggregate completely, remove the
2783 statement too. In the third case, we want the LHS components to be loaded
2784 directly from the RHS (DSE will remove the original statement if it
2787 This is a bit complex but manageable when types match and when unions do
2788 not cause confusion in a way that we cannot really load a component of LHS
2789 from the RHS or vice versa (the access representing this level can have
2790 subaccesses that are accessible only through a different union field at a
2791 higher level - different from the one used in the examined expression).
2794 Therefore, I specially handle a fourth case, happening when there is a
2795 specific type cast or it is impossible to locate a scalarized subaccess on
2796 the other side of the expression. If that happens, I simply "refresh" the
2797 RHS by storing in it is scalarized components leave the original statement
2798 there to do the copying and then load the scalar replacements of the LHS.
2799 This is what the first branch does. */
2801 if (gimple_has_volatile_ops (*stmt
)
2802 || contains_vce_or_bfcref_p (rhs
)
2803 || contains_vce_or_bfcref_p (lhs
))
2805 if (access_has_children_p (racc
))
2806 generate_subtree_copies (racc
->first_child
, racc
->base
, 0, 0, 0,
2807 gsi
, false, false, loc
);
2808 if (access_has_children_p (lacc
))
2809 generate_subtree_copies (lacc
->first_child
, lacc
->base
, 0, 0, 0,
2810 gsi
, true, true, loc
);
2811 sra_stats
.separate_lhs_rhs_handling
++;
2815 if (access_has_children_p (lacc
) && access_has_children_p (racc
))
2817 gimple_stmt_iterator orig_gsi
= *gsi
;
2818 enum unscalarized_data_handling refreshed
;
2820 if (lacc
->grp_read
&& !lacc
->grp_covered
)
2821 refreshed
= handle_unscalarized_data_in_subtree (racc
, gsi
);
2823 refreshed
= SRA_UDH_NONE
;
2825 load_assign_lhs_subreplacements (lacc
, racc
, lacc
->offset
,
2826 &orig_gsi
, gsi
, &refreshed
);
2827 if (refreshed
!= SRA_UDH_RIGHT
)
2830 unlink_stmt_vdef (*stmt
);
2831 gsi_remove (&orig_gsi
, true);
2832 sra_stats
.deleted
++;
2833 return SRA_AM_REMOVED
;
2840 if (!racc
->grp_to_be_replaced
&& !racc
->grp_unscalarized_data
)
2844 fprintf (dump_file
, "Removing load: ");
2845 print_gimple_stmt (dump_file
, *stmt
, 0, 0);
2848 if (TREE_CODE (lhs
) == SSA_NAME
)
2850 rhs
= get_repl_default_def_ssa_name (racc
);
2851 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
2853 rhs
= fold_build1_loc (loc
, VIEW_CONVERT_EXPR
,
2854 TREE_TYPE (lhs
), rhs
);
2858 if (racc
->first_child
)
2859 generate_subtree_copies (racc
->first_child
, lhs
,
2860 racc
->offset
, 0, 0, gsi
,
2863 gcc_assert (*stmt
== gsi_stmt (*gsi
));
2864 unlink_stmt_vdef (*stmt
);
2865 gsi_remove (gsi
, true);
2866 sra_stats
.deleted
++;
2867 return SRA_AM_REMOVED
;
2870 else if (racc
->first_child
)
2871 generate_subtree_copies (racc
->first_child
, lhs
, racc
->offset
,
2872 0, 0, gsi
, false, true, loc
);
2874 if (access_has_children_p (lacc
))
2875 generate_subtree_copies (lacc
->first_child
, rhs
, lacc
->offset
,
2876 0, 0, gsi
, true, true, loc
);
2880 /* This gimplification must be done after generate_subtree_copies, lest we
2881 insert the subtree copies in the middle of the gimplified sequence. */
2882 if (force_gimple_rhs
)
2883 rhs
= force_gimple_operand_gsi (&orig_gsi
, rhs
, true, NULL_TREE
,
2884 true, GSI_SAME_STMT
);
2885 if (gimple_assign_rhs1 (*stmt
) != rhs
)
2887 modify_this_stmt
= true;
2888 gimple_assign_set_rhs_from_tree (&orig_gsi
, rhs
);
2889 gcc_assert (*stmt
== gsi_stmt (orig_gsi
));
2892 return modify_this_stmt
? SRA_AM_MODIFIED
: SRA_AM_NONE
;
2895 /* Traverse the function body and all modifications as decided in
2896 analyze_all_variable_accesses. Return true iff the CFG has been
2900 sra_modify_function_body (void)
2902 bool cfg_changed
= false;
2907 gimple_stmt_iterator gsi
= gsi_start_bb (bb
);
2908 while (!gsi_end_p (gsi
))
2910 gimple stmt
= gsi_stmt (gsi
);
2911 enum assignment_mod_result assign_result
;
2912 bool modified
= false, deleted
= false;
2916 switch (gimple_code (stmt
))
2919 t
= gimple_return_retval_ptr (stmt
);
2920 if (*t
!= NULL_TREE
)
2921 modified
|= sra_modify_expr (t
, &gsi
, false);
2925 assign_result
= sra_modify_assign (&stmt
, &gsi
);
2926 modified
|= assign_result
== SRA_AM_MODIFIED
;
2927 deleted
= assign_result
== SRA_AM_REMOVED
;
2931 /* Operands must be processed before the lhs. */
2932 for (i
= 0; i
< gimple_call_num_args (stmt
); i
++)
2934 t
= gimple_call_arg_ptr (stmt
, i
);
2935 modified
|= sra_modify_expr (t
, &gsi
, false);
2938 if (gimple_call_lhs (stmt
))
2940 t
= gimple_call_lhs_ptr (stmt
);
2941 modified
|= sra_modify_expr (t
, &gsi
, true);
2946 for (i
= 0; i
< gimple_asm_ninputs (stmt
); i
++)
2948 t
= &TREE_VALUE (gimple_asm_input_op (stmt
, i
));
2949 modified
|= sra_modify_expr (t
, &gsi
, false);
2951 for (i
= 0; i
< gimple_asm_noutputs (stmt
); i
++)
2953 t
= &TREE_VALUE (gimple_asm_output_op (stmt
, i
));
2954 modified
|= sra_modify_expr (t
, &gsi
, true);
2965 if (maybe_clean_eh_stmt (stmt
)
2966 && gimple_purge_dead_eh_edges (gimple_bb (stmt
)))
2977 /* Generate statements initializing scalar replacements of parts of function
2981 initialize_parameter_reductions (void)
2983 gimple_stmt_iterator gsi
;
2984 gimple_seq seq
= NULL
;
2987 for (parm
= DECL_ARGUMENTS (current_function_decl
);
2989 parm
= DECL_CHAIN (parm
))
2991 VEC (access_p
, heap
) *access_vec
;
2992 struct access
*access
;
2994 if (!bitmap_bit_p (candidate_bitmap
, DECL_UID (parm
)))
2996 access_vec
= get_base_access_vector (parm
);
3002 seq
= gimple_seq_alloc ();
3003 gsi
= gsi_start (seq
);
3006 for (access
= VEC_index (access_p
, access_vec
, 0);
3008 access
= access
->next_grp
)
3009 generate_subtree_copies (access
, parm
, 0, 0, 0, &gsi
, true, true,
3010 EXPR_LOCATION (parm
));
3014 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR
), seq
);
3017 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
3018 it reveals there are components of some aggregates to be scalarized, it runs
3019 the required transformations. */
3021 perform_intra_sra (void)
3026 if (!find_var_candidates ())
3029 if (!scan_function ())
3032 if (!analyze_all_variable_accesses ())
3035 if (sra_modify_function_body ())
3036 ret
= TODO_update_ssa
| TODO_cleanup_cfg
;
3038 ret
= TODO_update_ssa
;
3039 initialize_parameter_reductions ();
3041 statistics_counter_event (cfun
, "Scalar replacements created",
3042 sra_stats
.replacements
);
3043 statistics_counter_event (cfun
, "Modified expressions", sra_stats
.exprs
);
3044 statistics_counter_event (cfun
, "Subtree copy stmts",
3045 sra_stats
.subtree_copies
);
3046 statistics_counter_event (cfun
, "Subreplacement stmts",
3047 sra_stats
.subreplacements
);
3048 statistics_counter_event (cfun
, "Deleted stmts", sra_stats
.deleted
);
3049 statistics_counter_event (cfun
, "Separate LHS and RHS handling",
3050 sra_stats
.separate_lhs_rhs_handling
);
3053 sra_deinitialize ();
3057 /* Perform early intraprocedural SRA. */
3059 early_intra_sra (void)
3061 sra_mode
= SRA_MODE_EARLY_INTRA
;
3062 return perform_intra_sra ();
3065 /* Perform "late" intraprocedural SRA. */
3067 late_intra_sra (void)
3069 sra_mode
= SRA_MODE_INTRA
;
3070 return perform_intra_sra ();
3075 gate_intra_sra (void)
3077 return flag_tree_sra
!= 0 && dbg_cnt (tree_sra
);
3081 struct gimple_opt_pass pass_sra_early
=
3086 gate_intra_sra
, /* gate */
3087 early_intra_sra
, /* execute */
3090 0, /* static_pass_number */
3091 TV_TREE_SRA
, /* tv_id */
3092 PROP_cfg
| PROP_ssa
, /* properties_required */
3093 0, /* properties_provided */
3094 0, /* properties_destroyed */
3095 0, /* todo_flags_start */
3098 | TODO_verify_ssa
/* todo_flags_finish */
3102 struct gimple_opt_pass pass_sra
=
3107 gate_intra_sra
, /* gate */
3108 late_intra_sra
, /* execute */
3111 0, /* static_pass_number */
3112 TV_TREE_SRA
, /* tv_id */
3113 PROP_cfg
| PROP_ssa
, /* properties_required */
3114 0, /* properties_provided */
3115 0, /* properties_destroyed */
3116 TODO_update_address_taken
, /* todo_flags_start */
3119 | TODO_verify_ssa
/* todo_flags_finish */
3124 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3128 is_unused_scalar_param (tree parm
)
3131 return (is_gimple_reg (parm
)
3132 && (!(name
= gimple_default_def (cfun
, parm
))
3133 || has_zero_uses (name
)));
3136 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3137 examine whether there are any direct or otherwise infeasible ones. If so,
3138 return true, otherwise return false. PARM must be a gimple register with a
3139 non-NULL default definition. */
3142 ptr_parm_has_direct_uses (tree parm
)
3144 imm_use_iterator ui
;
3146 tree name
= gimple_default_def (cfun
, parm
);
3149 FOR_EACH_IMM_USE_STMT (stmt
, ui
, name
)
3152 use_operand_p use_p
;
3154 if (is_gimple_debug (stmt
))
3157 /* Valid uses include dereferences on the lhs and the rhs. */
3158 if (gimple_has_lhs (stmt
))
3160 tree lhs
= gimple_get_lhs (stmt
);
3161 while (handled_component_p (lhs
))
3162 lhs
= TREE_OPERAND (lhs
, 0);
3163 if (TREE_CODE (lhs
) == MEM_REF
3164 && TREE_OPERAND (lhs
, 0) == name
3165 && integer_zerop (TREE_OPERAND (lhs
, 1))
3166 && types_compatible_p (TREE_TYPE (lhs
),
3167 TREE_TYPE (TREE_TYPE (name
))))
3170 if (gimple_assign_single_p (stmt
))
3172 tree rhs
= gimple_assign_rhs1 (stmt
);
3173 while (handled_component_p (rhs
))
3174 rhs
= TREE_OPERAND (rhs
, 0);
3175 if (TREE_CODE (rhs
) == MEM_REF
3176 && TREE_OPERAND (rhs
, 0) == name
3177 && integer_zerop (TREE_OPERAND (rhs
, 1))
3178 && types_compatible_p (TREE_TYPE (rhs
),
3179 TREE_TYPE (TREE_TYPE (name
))))
3182 else if (is_gimple_call (stmt
))
3185 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
3187 tree arg
= gimple_call_arg (stmt
, i
);
3188 while (handled_component_p (arg
))
3189 arg
= TREE_OPERAND (arg
, 0);
3190 if (TREE_CODE (arg
) == MEM_REF
3191 && TREE_OPERAND (arg
, 0) == name
3192 && integer_zerop (TREE_OPERAND (arg
, 1))
3193 && types_compatible_p (TREE_TYPE (arg
),
3194 TREE_TYPE (TREE_TYPE (name
))))
3199 /* If the number of valid uses does not match the number of
3200 uses in this stmt there is an unhandled use. */
3201 FOR_EACH_IMM_USE_ON_STMT (use_p
, ui
)
3208 BREAK_FROM_IMM_USE_STMT (ui
);
3214 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3215 them in candidate_bitmap. Note that these do not necessarily include
3216 parameter which are unused and thus can be removed. Return true iff any
3217 such candidate has been found. */
3220 find_param_candidates (void)
3226 for (parm
= DECL_ARGUMENTS (current_function_decl
);
3228 parm
= DECL_CHAIN (parm
))
3230 tree type
= TREE_TYPE (parm
);
3234 if (TREE_THIS_VOLATILE (parm
)
3235 || TREE_ADDRESSABLE (parm
)
3236 || (!is_gimple_reg_type (type
) && is_va_list_type (type
)))
3239 if (is_unused_scalar_param (parm
))
3245 if (POINTER_TYPE_P (type
))
3247 type
= TREE_TYPE (type
);
3249 if (TREE_CODE (type
) == FUNCTION_TYPE
3250 || TYPE_VOLATILE (type
)
3251 || (TREE_CODE (type
) == ARRAY_TYPE
3252 && TYPE_NONALIASED_COMPONENT (type
))
3253 || !is_gimple_reg (parm
)
3254 || is_va_list_type (type
)
3255 || ptr_parm_has_direct_uses (parm
))
3258 else if (!AGGREGATE_TYPE_P (type
))
3261 if (!COMPLETE_TYPE_P (type
)
3262 || !host_integerp (TYPE_SIZE (type
), 1)
3263 || tree_low_cst (TYPE_SIZE (type
), 1) == 0
3264 || (AGGREGATE_TYPE_P (type
)
3265 && type_internals_preclude_sra_p (type
)))
3268 bitmap_set_bit (candidate_bitmap
, DECL_UID (parm
));
3270 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3272 fprintf (dump_file
, "Candidate (%d): ", DECL_UID (parm
));
3273 print_generic_expr (dump_file
, parm
, 0);
3274 fprintf (dump_file
, "\n");
3278 func_param_count
= count
;
3282 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3286 mark_maybe_modified (ao_ref
*ao ATTRIBUTE_UNUSED
, tree vdef ATTRIBUTE_UNUSED
,
3289 struct access
*repr
= (struct access
*) data
;
3291 repr
->grp_maybe_modified
= 1;
3295 /* Analyze what representatives (in linked lists accessible from
3296 REPRESENTATIVES) can be modified by side effects of statements in the
3297 current function. */
3300 analyze_modified_params (VEC (access_p
, heap
) *representatives
)
3304 for (i
= 0; i
< func_param_count
; i
++)
3306 struct access
*repr
;
3308 for (repr
= VEC_index (access_p
, representatives
, i
);
3310 repr
= repr
->next_grp
)
3312 struct access
*access
;
3316 if (no_accesses_p (repr
))
3318 if (!POINTER_TYPE_P (TREE_TYPE (repr
->base
))
3319 || repr
->grp_maybe_modified
)
3322 ao_ref_init (&ar
, repr
->expr
);
3323 visited
= BITMAP_ALLOC (NULL
);
3324 for (access
= repr
; access
; access
= access
->next_sibling
)
3326 /* All accesses are read ones, otherwise grp_maybe_modified would
3327 be trivially set. */
3328 walk_aliased_vdefs (&ar
, gimple_vuse (access
->stmt
),
3329 mark_maybe_modified
, repr
, &visited
);
3330 if (repr
->grp_maybe_modified
)
3333 BITMAP_FREE (visited
);
3338 /* Propagate distances in bb_dereferences in the opposite direction than the
3339 control flow edges, in each step storing the maximum of the current value
3340 and the minimum of all successors. These steps are repeated until the table
3341 stabilizes. Note that BBs which might terminate the functions (according to
3342 final_bbs bitmap) never updated in this way. */
3345 propagate_dereference_distances (void)
3347 VEC (basic_block
, heap
) *queue
;
3350 queue
= VEC_alloc (basic_block
, heap
, last_basic_block_for_function (cfun
));
3351 VEC_quick_push (basic_block
, queue
, ENTRY_BLOCK_PTR
);
3354 VEC_quick_push (basic_block
, queue
, bb
);
3358 while (!VEC_empty (basic_block
, queue
))
3362 bool change
= false;
3365 bb
= VEC_pop (basic_block
, queue
);
3368 if (bitmap_bit_p (final_bbs
, bb
->index
))
3371 for (i
= 0; i
< func_param_count
; i
++)
3373 int idx
= bb
->index
* func_param_count
+ i
;
3375 HOST_WIDE_INT inh
= 0;
3377 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3379 int succ_idx
= e
->dest
->index
* func_param_count
+ i
;
3381 if (e
->src
== EXIT_BLOCK_PTR
)
3387 inh
= bb_dereferences
[succ_idx
];
3389 else if (bb_dereferences
[succ_idx
] < inh
)
3390 inh
= bb_dereferences
[succ_idx
];
3393 if (!first
&& bb_dereferences
[idx
] < inh
)
3395 bb_dereferences
[idx
] = inh
;
3400 if (change
&& !bitmap_bit_p (final_bbs
, bb
->index
))
3401 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3406 e
->src
->aux
= e
->src
;
3407 VEC_quick_push (basic_block
, queue
, e
->src
);
3411 VEC_free (basic_block
, heap
, queue
);
3414 /* Dump a dereferences TABLE with heading STR to file F. */
3417 dump_dereferences_table (FILE *f
, const char *str
, HOST_WIDE_INT
*table
)
3421 fprintf (dump_file
, str
);
3422 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, EXIT_BLOCK_PTR
, next_bb
)
3424 fprintf (f
, "%4i %i ", bb
->index
, bitmap_bit_p (final_bbs
, bb
->index
));
3425 if (bb
!= EXIT_BLOCK_PTR
)
3428 for (i
= 0; i
< func_param_count
; i
++)
3430 int idx
= bb
->index
* func_param_count
+ i
;
3431 fprintf (f
, " %4" HOST_WIDE_INT_PRINT
"d", table
[idx
]);
3436 fprintf (dump_file
, "\n");
3439 /* Determine what (parts of) parameters passed by reference that are not
3440 assigned to are not certainly dereferenced in this function and thus the
3441 dereferencing cannot be safely moved to the caller without potentially
3442 introducing a segfault. Mark such REPRESENTATIVES as
3443 grp_not_necessarilly_dereferenced.
3445 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3446 part is calculated rather than simple booleans are calculated for each
3447 pointer parameter to handle cases when only a fraction of the whole
3448 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3451 The maximum dereference distances for each pointer parameter and BB are
3452 already stored in bb_dereference. This routine simply propagates these
3453 values upwards by propagate_dereference_distances and then compares the
3454 distances of individual parameters in the ENTRY BB to the equivalent
3455 distances of each representative of a (fraction of a) parameter. */
3458 analyze_caller_dereference_legality (VEC (access_p
, heap
) *representatives
)
3462 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3463 dump_dereferences_table (dump_file
,
3464 "Dereference table before propagation:\n",
3467 propagate_dereference_distances ();
3469 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3470 dump_dereferences_table (dump_file
,
3471 "Dereference table after propagation:\n",
3474 for (i
= 0; i
< func_param_count
; i
++)
3476 struct access
*repr
= VEC_index (access_p
, representatives
, i
);
3477 int idx
= ENTRY_BLOCK_PTR
->index
* func_param_count
+ i
;
3479 if (!repr
|| no_accesses_p (repr
))
3484 if ((repr
->offset
+ repr
->size
) > bb_dereferences
[idx
])
3485 repr
->grp_not_necessarilly_dereferenced
= 1;
3486 repr
= repr
->next_grp
;
3492 /* Return the representative access for the parameter declaration PARM if it is
3493 a scalar passed by reference which is not written to and the pointer value
3494 is not used directly. Thus, if it is legal to dereference it in the caller
3495 and we can rule out modifications through aliases, such parameter should be
3496 turned into one passed by value. Return NULL otherwise. */
3498 static struct access
*
3499 unmodified_by_ref_scalar_representative (tree parm
)
3501 int i
, access_count
;
3502 struct access
*repr
;
3503 VEC (access_p
, heap
) *access_vec
;
3505 access_vec
= get_base_access_vector (parm
);
3506 gcc_assert (access_vec
);
3507 repr
= VEC_index (access_p
, access_vec
, 0);
3510 repr
->group_representative
= repr
;
3512 access_count
= VEC_length (access_p
, access_vec
);
3513 for (i
= 1; i
< access_count
; i
++)
3515 struct access
*access
= VEC_index (access_p
, access_vec
, i
);
3518 access
->group_representative
= repr
;
3519 access
->next_sibling
= repr
->next_sibling
;
3520 repr
->next_sibling
= access
;
3524 repr
->grp_scalar_ptr
= 1;
3528 /* Return true iff this access precludes IPA-SRA of the parameter it is
3532 access_precludes_ipa_sra_p (struct access
*access
)
3534 /* Avoid issues such as the second simple testcase in PR 42025. The problem
3535 is incompatible assign in a call statement (and possibly even in asm
3536 statements). This can be relaxed by using a new temporary but only for
3537 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
3538 intraprocedural SRA we deal with this by keeping the old aggregate around,
3539 something we cannot do in IPA-SRA.) */
3541 && (is_gimple_call (access
->stmt
)
3542 || gimple_code (access
->stmt
) == GIMPLE_ASM
))
3549 /* Sort collected accesses for parameter PARM, identify representatives for
3550 each accessed region and link them together. Return NULL if there are
3551 different but overlapping accesses, return the special ptr value meaning
3552 there are no accesses for this parameter if that is the case and return the
3553 first representative otherwise. Set *RO_GRP if there is a group of accesses
3554 with only read (i.e. no write) accesses. */
3556 static struct access
*
3557 splice_param_accesses (tree parm
, bool *ro_grp
)
3559 int i
, j
, access_count
, group_count
;
3560 int agg_size
, total_size
= 0;
3561 struct access
*access
, *res
, **prev_acc_ptr
= &res
;
3562 VEC (access_p
, heap
) *access_vec
;
3564 access_vec
= get_base_access_vector (parm
);
3566 return &no_accesses_representant
;
3567 access_count
= VEC_length (access_p
, access_vec
);
3569 VEC_qsort (access_p
, access_vec
, compare_access_positions
);
3574 while (i
< access_count
)
3578 access
= VEC_index (access_p
, access_vec
, i
);
3579 modification
= access
->write
;
3580 if (access_precludes_ipa_sra_p (access
))
3582 a1_alias_type
= reference_alias_ptr_type (access
->expr
);
3584 /* Access is about to become group representative unless we find some
3585 nasty overlap which would preclude us from breaking this parameter
3589 while (j
< access_count
)
3591 struct access
*ac2
= VEC_index (access_p
, access_vec
, j
);
3592 if (ac2
->offset
!= access
->offset
)
3594 /* All or nothing law for parameters. */
3595 if (access
->offset
+ access
->size
> ac2
->offset
)
3600 else if (ac2
->size
!= access
->size
)
3603 if (access_precludes_ipa_sra_p (ac2
)
3604 || (ac2
->type
!= access
->type
3605 && (TREE_ADDRESSABLE (ac2
->type
)
3606 || TREE_ADDRESSABLE (access
->type
)))
3607 || (reference_alias_ptr_type (ac2
->expr
) != a1_alias_type
))
3610 modification
|= ac2
->write
;
3611 ac2
->group_representative
= access
;
3612 ac2
->next_sibling
= access
->next_sibling
;
3613 access
->next_sibling
= ac2
;
3618 access
->grp_maybe_modified
= modification
;
3621 *prev_acc_ptr
= access
;
3622 prev_acc_ptr
= &access
->next_grp
;
3623 total_size
+= access
->size
;
3627 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
3628 agg_size
= tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm
))), 1);
3630 agg_size
= tree_low_cst (TYPE_SIZE (TREE_TYPE (parm
)), 1);
3631 if (total_size
>= agg_size
)
3634 gcc_assert (group_count
> 0);
3638 /* Decide whether parameters with representative accesses given by REPR should
3639 be reduced into components. */
3642 decide_one_param_reduction (struct access
*repr
)
3644 int total_size
, cur_parm_size
, agg_size
, new_param_count
, parm_size_limit
;
3649 cur_parm_size
= tree_low_cst (TYPE_SIZE (TREE_TYPE (parm
)), 1);
3650 gcc_assert (cur_parm_size
> 0);
3652 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
3655 agg_size
= tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm
))), 1);
3660 agg_size
= cur_parm_size
;
3666 fprintf (dump_file
, "Evaluating PARAM group sizes for ");
3667 print_generic_expr (dump_file
, parm
, 0);
3668 fprintf (dump_file
, " (UID: %u): \n", DECL_UID (parm
));
3669 for (acc
= repr
; acc
; acc
= acc
->next_grp
)
3670 dump_access (dump_file
, acc
, true);
3674 new_param_count
= 0;
3676 for (; repr
; repr
= repr
->next_grp
)
3678 gcc_assert (parm
== repr
->base
);
3680 /* Taking the address of a non-addressable field is verboten. */
3681 if (by_ref
&& repr
->non_addressable
)
3684 if (!by_ref
|| (!repr
->grp_maybe_modified
3685 && !repr
->grp_not_necessarilly_dereferenced
))
3686 total_size
+= repr
->size
;
3688 total_size
+= cur_parm_size
;
3693 gcc_assert (new_param_count
> 0);
3695 if (optimize_function_for_size_p (cfun
))
3696 parm_size_limit
= cur_parm_size
;
3698 parm_size_limit
= (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR
)
3701 if (total_size
< agg_size
3702 && total_size
<= parm_size_limit
)
3705 fprintf (dump_file
, " ....will be split into %i components\n",
3707 return new_param_count
;
3713 /* The order of the following enums is important, we need to do extra work for
3714 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
3715 enum ipa_splicing_result
{ NO_GOOD_ACCESS
, UNUSED_PARAMS
, BY_VAL_ACCESSES
,
3716 MODIF_BY_REF_ACCESSES
, UNMODIF_BY_REF_ACCESSES
};
3718 /* Identify representatives of all accesses to all candidate parameters for
3719 IPA-SRA. Return result based on what representatives have been found. */
3721 static enum ipa_splicing_result
3722 splice_all_param_accesses (VEC (access_p
, heap
) **representatives
)
3724 enum ipa_splicing_result result
= NO_GOOD_ACCESS
;
3726 struct access
*repr
;
3728 *representatives
= VEC_alloc (access_p
, heap
, func_param_count
);
3730 for (parm
= DECL_ARGUMENTS (current_function_decl
);
3732 parm
= DECL_CHAIN (parm
))
3734 if (is_unused_scalar_param (parm
))
3736 VEC_quick_push (access_p
, *representatives
,
3737 &no_accesses_representant
);
3738 if (result
== NO_GOOD_ACCESS
)
3739 result
= UNUSED_PARAMS
;
3741 else if (POINTER_TYPE_P (TREE_TYPE (parm
))
3742 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm
)))
3743 && bitmap_bit_p (candidate_bitmap
, DECL_UID (parm
)))
3745 repr
= unmodified_by_ref_scalar_representative (parm
);
3746 VEC_quick_push (access_p
, *representatives
, repr
);
3748 result
= UNMODIF_BY_REF_ACCESSES
;
3750 else if (bitmap_bit_p (candidate_bitmap
, DECL_UID (parm
)))
3752 bool ro_grp
= false;
3753 repr
= splice_param_accesses (parm
, &ro_grp
);
3754 VEC_quick_push (access_p
, *representatives
, repr
);
3756 if (repr
&& !no_accesses_p (repr
))
3758 if (POINTER_TYPE_P (TREE_TYPE (parm
)))
3761 result
= UNMODIF_BY_REF_ACCESSES
;
3762 else if (result
< MODIF_BY_REF_ACCESSES
)
3763 result
= MODIF_BY_REF_ACCESSES
;
3765 else if (result
< BY_VAL_ACCESSES
)
3766 result
= BY_VAL_ACCESSES
;
3768 else if (no_accesses_p (repr
) && (result
== NO_GOOD_ACCESS
))
3769 result
= UNUSED_PARAMS
;
3772 VEC_quick_push (access_p
, *representatives
, NULL
);
3775 if (result
== NO_GOOD_ACCESS
)
3777 VEC_free (access_p
, heap
, *representatives
);
3778 *representatives
= NULL
;
3779 return NO_GOOD_ACCESS
;
3785 /* Return the index of BASE in PARMS. Abort if it is not found. */
3788 get_param_index (tree base
, VEC(tree
, heap
) *parms
)
3792 len
= VEC_length (tree
, parms
);
3793 for (i
= 0; i
< len
; i
++)
3794 if (VEC_index (tree
, parms
, i
) == base
)
3799 /* Convert the decisions made at the representative level into compact
3800 parameter adjustments. REPRESENTATIVES are pointers to first
3801 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
3802 final number of adjustments. */
3804 static ipa_parm_adjustment_vec
3805 turn_representatives_into_adjustments (VEC (access_p
, heap
) *representatives
,
3806 int adjustments_count
)
3808 VEC (tree
, heap
) *parms
;
3809 ipa_parm_adjustment_vec adjustments
;
3813 gcc_assert (adjustments_count
> 0);
3814 parms
= ipa_get_vector_of_formal_parms (current_function_decl
);
3815 adjustments
= VEC_alloc (ipa_parm_adjustment_t
, heap
, adjustments_count
);
3816 parm
= DECL_ARGUMENTS (current_function_decl
);
3817 for (i
= 0; i
< func_param_count
; i
++, parm
= DECL_CHAIN (parm
))
3819 struct access
*repr
= VEC_index (access_p
, representatives
, i
);
3821 if (!repr
|| no_accesses_p (repr
))
3823 struct ipa_parm_adjustment
*adj
;
3825 adj
= VEC_quick_push (ipa_parm_adjustment_t
, adjustments
, NULL
);
3826 memset (adj
, 0, sizeof (*adj
));
3827 adj
->base_index
= get_param_index (parm
, parms
);
3830 adj
->copy_param
= 1;
3832 adj
->remove_param
= 1;
3836 struct ipa_parm_adjustment
*adj
;
3837 int index
= get_param_index (parm
, parms
);
3839 for (; repr
; repr
= repr
->next_grp
)
3841 adj
= VEC_quick_push (ipa_parm_adjustment_t
, adjustments
, NULL
);
3842 memset (adj
, 0, sizeof (*adj
));
3843 gcc_assert (repr
->base
== parm
);
3844 adj
->base_index
= index
;
3845 adj
->base
= repr
->base
;
3846 adj
->type
= repr
->type
;
3847 adj
->alias_ptr_type
= reference_alias_ptr_type (repr
->expr
);
3848 adj
->offset
= repr
->offset
;
3849 adj
->by_ref
= (POINTER_TYPE_P (TREE_TYPE (repr
->base
))
3850 && (repr
->grp_maybe_modified
3851 || repr
->grp_not_necessarilly_dereferenced
));
3856 VEC_free (tree
, heap
, parms
);
3860 /* Analyze the collected accesses and produce a plan what to do with the
3861 parameters in the form of adjustments, NULL meaning nothing. */
3863 static ipa_parm_adjustment_vec
3864 analyze_all_param_acesses (void)
3866 enum ipa_splicing_result repr_state
;
3867 bool proceed
= false;
3868 int i
, adjustments_count
= 0;
3869 VEC (access_p
, heap
) *representatives
;
3870 ipa_parm_adjustment_vec adjustments
;
3872 repr_state
= splice_all_param_accesses (&representatives
);
3873 if (repr_state
== NO_GOOD_ACCESS
)
3876 /* If there are any parameters passed by reference which are not modified
3877 directly, we need to check whether they can be modified indirectly. */
3878 if (repr_state
== UNMODIF_BY_REF_ACCESSES
)
3880 analyze_caller_dereference_legality (representatives
);
3881 analyze_modified_params (representatives
);
3884 for (i
= 0; i
< func_param_count
; i
++)
3886 struct access
*repr
= VEC_index (access_p
, representatives
, i
);
3888 if (repr
&& !no_accesses_p (repr
))
3890 if (repr
->grp_scalar_ptr
)
3892 adjustments_count
++;
3893 if (repr
->grp_not_necessarilly_dereferenced
3894 || repr
->grp_maybe_modified
)
3895 VEC_replace (access_p
, representatives
, i
, NULL
);
3899 sra_stats
.scalar_by_ref_to_by_val
++;
3904 int new_components
= decide_one_param_reduction (repr
);
3906 if (new_components
== 0)
3908 VEC_replace (access_p
, representatives
, i
, NULL
);
3909 adjustments_count
++;
3913 adjustments_count
+= new_components
;
3914 sra_stats
.aggregate_params_reduced
++;
3915 sra_stats
.param_reductions_created
+= new_components
;
3922 if (no_accesses_p (repr
))
3925 sra_stats
.deleted_unused_parameters
++;
3927 adjustments_count
++;
3931 if (!proceed
&& dump_file
)
3932 fprintf (dump_file
, "NOT proceeding to change params.\n");
3935 adjustments
= turn_representatives_into_adjustments (representatives
,
3940 VEC_free (access_p
, heap
, representatives
);
3944 /* If a parameter replacement identified by ADJ does not yet exist in the form
3945 of declaration, create it and record it, otherwise return the previously
3949 get_replaced_param_substitute (struct ipa_parm_adjustment
*adj
)
3952 if (!adj
->new_ssa_base
)
3954 char *pretty_name
= make_fancy_name (adj
->base
);
3956 repl
= create_tmp_reg (TREE_TYPE (adj
->base
), "ISR");
3957 DECL_NAME (repl
) = get_identifier (pretty_name
);
3958 obstack_free (&name_obstack
, pretty_name
);
3961 add_referenced_var (repl
);
3962 adj
->new_ssa_base
= repl
;
3965 repl
= adj
->new_ssa_base
;
3969 /* Find the first adjustment for a particular parameter BASE in a vector of
3970 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
3973 static struct ipa_parm_adjustment
*
3974 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments
, tree base
)
3978 len
= VEC_length (ipa_parm_adjustment_t
, adjustments
);
3979 for (i
= 0; i
< len
; i
++)
3981 struct ipa_parm_adjustment
*adj
;
3983 adj
= VEC_index (ipa_parm_adjustment_t
, adjustments
, i
);
3984 if (!adj
->copy_param
&& adj
->base
== base
)
3991 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
3992 removed because its value is not used, replace the SSA_NAME with a one
3993 relating to a created VAR_DECL together all of its uses and return true.
3994 ADJUSTMENTS is a pointer to an adjustments vector. */
3997 replace_removed_params_ssa_names (gimple stmt
,
3998 ipa_parm_adjustment_vec adjustments
)
4000 struct ipa_parm_adjustment
*adj
;
4001 tree lhs
, decl
, repl
, name
;
4003 if (gimple_code (stmt
) == GIMPLE_PHI
)
4004 lhs
= gimple_phi_result (stmt
);
4005 else if (is_gimple_assign (stmt
))
4006 lhs
= gimple_assign_lhs (stmt
);
4007 else if (is_gimple_call (stmt
))
4008 lhs
= gimple_call_lhs (stmt
);
4012 if (TREE_CODE (lhs
) != SSA_NAME
)
4014 decl
= SSA_NAME_VAR (lhs
);
4015 if (TREE_CODE (decl
) != PARM_DECL
)
4018 adj
= get_adjustment_for_base (adjustments
, decl
);
4022 repl
= get_replaced_param_substitute (adj
);
4023 name
= make_ssa_name (repl
, stmt
);
4027 fprintf (dump_file
, "replacing an SSA name of a removed param ");
4028 print_generic_expr (dump_file
, lhs
, 0);
4029 fprintf (dump_file
, " with ");
4030 print_generic_expr (dump_file
, name
, 0);
4031 fprintf (dump_file
, "\n");
4034 if (is_gimple_assign (stmt
))
4035 gimple_assign_set_lhs (stmt
, name
);
4036 else if (is_gimple_call (stmt
))
4037 gimple_call_set_lhs (stmt
, name
);
4039 gimple_phi_set_result (stmt
, name
);
4041 replace_uses_by (lhs
, name
);
4042 release_ssa_name (lhs
);
4046 /* If the expression *EXPR should be replaced by a reduction of a parameter, do
4047 so. ADJUSTMENTS is a pointer to a vector of adjustments. CONVERT
4048 specifies whether the function should care about type incompatibility the
4049 current and new expressions. If it is false, the function will leave
4050 incompatibility issues to the caller. Return true iff the expression
4054 sra_ipa_modify_expr (tree
*expr
, bool convert
,
4055 ipa_parm_adjustment_vec adjustments
)
4058 struct ipa_parm_adjustment
*adj
, *cand
= NULL
;
4059 HOST_WIDE_INT offset
, size
, max_size
;
4062 len
= VEC_length (ipa_parm_adjustment_t
, adjustments
);
4064 if (TREE_CODE (*expr
) == BIT_FIELD_REF
4065 || TREE_CODE (*expr
) == IMAGPART_EXPR
4066 || TREE_CODE (*expr
) == REALPART_EXPR
)
4068 expr
= &TREE_OPERAND (*expr
, 0);
4072 base
= get_ref_base_and_extent (*expr
, &offset
, &size
, &max_size
);
4073 if (!base
|| size
== -1 || max_size
== -1)
4076 if (TREE_CODE (base
) == MEM_REF
)
4078 offset
+= mem_ref_offset (base
).low
* BITS_PER_UNIT
;
4079 base
= TREE_OPERAND (base
, 0);
4082 base
= get_ssa_base_param (base
);
4083 if (!base
|| TREE_CODE (base
) != PARM_DECL
)
4086 for (i
= 0; i
< len
; i
++)
4088 adj
= VEC_index (ipa_parm_adjustment_t
, adjustments
, i
);
4090 if (adj
->base
== base
&&
4091 (adj
->offset
== offset
|| adj
->remove_param
))
4097 if (!cand
|| cand
->copy_param
|| cand
->remove_param
)
4101 src
= build_simple_mem_ref (cand
->reduction
);
4103 src
= cand
->reduction
;
4105 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4107 fprintf (dump_file
, "About to replace expr ");
4108 print_generic_expr (dump_file
, *expr
, 0);
4109 fprintf (dump_file
, " with ");
4110 print_generic_expr (dump_file
, src
, 0);
4111 fprintf (dump_file
, "\n");
4114 if (convert
&& !useless_type_conversion_p (TREE_TYPE (*expr
), cand
->type
))
4116 tree vce
= build1 (VIEW_CONVERT_EXPR
, TREE_TYPE (*expr
), src
);
4124 /* If the statement pointed to by STMT_PTR contains any expressions that need
4125 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4126 potential type incompatibilities (GSI is used to accommodate conversion
4127 statements and must point to the statement). Return true iff the statement
4131 sra_ipa_modify_assign (gimple
*stmt_ptr
, gimple_stmt_iterator
*gsi
,
4132 ipa_parm_adjustment_vec adjustments
)
4134 gimple stmt
= *stmt_ptr
;
4135 tree
*lhs_p
, *rhs_p
;
4138 if (!gimple_assign_single_p (stmt
))
4141 rhs_p
= gimple_assign_rhs1_ptr (stmt
);
4142 lhs_p
= gimple_assign_lhs_ptr (stmt
);
4144 any
= sra_ipa_modify_expr (rhs_p
, false, adjustments
);
4145 any
|= sra_ipa_modify_expr (lhs_p
, false, adjustments
);
4148 tree new_rhs
= NULL_TREE
;
4150 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p
), TREE_TYPE (*rhs_p
)))
4152 if (TREE_CODE (*rhs_p
) == CONSTRUCTOR
)
4154 /* V_C_Es of constructors can cause trouble (PR 42714). */
4155 if (is_gimple_reg_type (TREE_TYPE (*lhs_p
)))
4156 *rhs_p
= build_zero_cst (TREE_TYPE (*lhs_p
));
4158 *rhs_p
= build_constructor (TREE_TYPE (*lhs_p
), 0);
4161 new_rhs
= fold_build1_loc (gimple_location (stmt
),
4162 VIEW_CONVERT_EXPR
, TREE_TYPE (*lhs_p
),
4165 else if (REFERENCE_CLASS_P (*rhs_p
)
4166 && is_gimple_reg_type (TREE_TYPE (*lhs_p
))
4167 && !is_gimple_reg (*lhs_p
))
4168 /* This can happen when an assignment in between two single field
4169 structures is turned into an assignment in between two pointers to
4170 scalars (PR 42237). */
4175 tree tmp
= force_gimple_operand_gsi (gsi
, new_rhs
, true, NULL_TREE
,
4176 true, GSI_SAME_STMT
);
4178 gimple_assign_set_rhs_from_tree (gsi
, tmp
);
4187 /* Traverse the function body and all modifications as described in
4188 ADJUSTMENTS. Return true iff the CFG has been changed. */
4191 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments
)
4193 bool cfg_changed
= false;
4198 gimple_stmt_iterator gsi
;
4200 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4201 replace_removed_params_ssa_names (gsi_stmt (gsi
), adjustments
);
4203 gsi
= gsi_start_bb (bb
);
4204 while (!gsi_end_p (gsi
))
4206 gimple stmt
= gsi_stmt (gsi
);
4207 bool modified
= false;
4211 switch (gimple_code (stmt
))
4214 t
= gimple_return_retval_ptr (stmt
);
4215 if (*t
!= NULL_TREE
)
4216 modified
|= sra_ipa_modify_expr (t
, true, adjustments
);
4220 modified
|= sra_ipa_modify_assign (&stmt
, &gsi
, adjustments
);
4221 modified
|= replace_removed_params_ssa_names (stmt
, adjustments
);
4225 /* Operands must be processed before the lhs. */
4226 for (i
= 0; i
< gimple_call_num_args (stmt
); i
++)
4228 t
= gimple_call_arg_ptr (stmt
, i
);
4229 modified
|= sra_ipa_modify_expr (t
, true, adjustments
);
4232 if (gimple_call_lhs (stmt
))
4234 t
= gimple_call_lhs_ptr (stmt
);
4235 modified
|= sra_ipa_modify_expr (t
, false, adjustments
);
4236 modified
|= replace_removed_params_ssa_names (stmt
,
4242 for (i
= 0; i
< gimple_asm_ninputs (stmt
); i
++)
4244 t
= &TREE_VALUE (gimple_asm_input_op (stmt
, i
));
4245 modified
|= sra_ipa_modify_expr (t
, true, adjustments
);
4247 for (i
= 0; i
< gimple_asm_noutputs (stmt
); i
++)
4249 t
= &TREE_VALUE (gimple_asm_output_op (stmt
, i
));
4250 modified
|= sra_ipa_modify_expr (t
, false, adjustments
);
4261 if (maybe_clean_eh_stmt (stmt
)
4262 && gimple_purge_dead_eh_edges (gimple_bb (stmt
)))
4272 /* Call gimple_debug_bind_reset_value on all debug statements describing
4273 gimple register parameters that are being removed or replaced. */
4276 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments
)
4280 len
= VEC_length (ipa_parm_adjustment_t
, adjustments
);
4281 for (i
= 0; i
< len
; i
++)
4283 struct ipa_parm_adjustment
*adj
;
4284 imm_use_iterator ui
;
4288 adj
= VEC_index (ipa_parm_adjustment_t
, adjustments
, i
);
4289 if (adj
->copy_param
|| !is_gimple_reg (adj
->base
))
4291 name
= gimple_default_def (cfun
, adj
->base
);
4294 FOR_EACH_IMM_USE_STMT (stmt
, ui
, name
)
4296 /* All other users must have been removed by
4297 ipa_sra_modify_function_body. */
4298 gcc_assert (is_gimple_debug (stmt
));
4299 gimple_debug_bind_reset_value (stmt
);
4305 /* Return false iff all callers have at least as many actual arguments as there
4306 are formal parameters in the current function. */
4309 not_all_callers_have_enough_arguments_p (struct cgraph_node
*node
,
4310 void *data ATTRIBUTE_UNUSED
)
4312 struct cgraph_edge
*cs
;
4313 for (cs
= node
->callers
; cs
; cs
= cs
->next_caller
)
4314 if (!callsite_has_enough_arguments_p (cs
->call_stmt
))
4320 /* Convert all callers of NODE. */
4323 convert_callers_for_node (struct cgraph_node
*node
,
4326 ipa_parm_adjustment_vec adjustments
= (ipa_parm_adjustment_vec
)data
;
4327 bitmap recomputed_callers
= BITMAP_ALLOC (NULL
);
4328 struct cgraph_edge
*cs
;
4330 for (cs
= node
->callers
; cs
; cs
= cs
->next_caller
)
4332 current_function_decl
= cs
->caller
->decl
;
4333 push_cfun (DECL_STRUCT_FUNCTION (cs
->caller
->decl
));
4336 fprintf (dump_file
, "Adjusting call (%i -> %i) %s -> %s\n",
4337 cs
->caller
->uid
, cs
->callee
->uid
,
4338 cgraph_node_name (cs
->caller
),
4339 cgraph_node_name (cs
->callee
));
4341 ipa_modify_call_arguments (cs
, cs
->call_stmt
, adjustments
);
4346 for (cs
= node
->callers
; cs
; cs
= cs
->next_caller
)
4347 if (bitmap_set_bit (recomputed_callers
, cs
->caller
->uid
)
4348 && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (cs
->caller
->decl
)))
4349 compute_inline_parameters (cs
->caller
, true);
4350 BITMAP_FREE (recomputed_callers
);
4355 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4358 convert_callers (struct cgraph_node
*node
, tree old_decl
,
4359 ipa_parm_adjustment_vec adjustments
)
4361 tree old_cur_fndecl
= current_function_decl
;
4362 basic_block this_block
;
4364 cgraph_for_node_and_aliases (node
, convert_callers_for_node
,
4365 adjustments
, false);
4367 current_function_decl
= old_cur_fndecl
;
4369 if (!encountered_recursive_call
)
4372 FOR_EACH_BB (this_block
)
4374 gimple_stmt_iterator gsi
;
4376 for (gsi
= gsi_start_bb (this_block
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4378 gimple stmt
= gsi_stmt (gsi
);
4380 if (gimple_code (stmt
) != GIMPLE_CALL
)
4382 call_fndecl
= gimple_call_fndecl (stmt
);
4383 if (call_fndecl
== old_decl
)
4386 fprintf (dump_file
, "Adjusting recursive call");
4387 gimple_call_set_fndecl (stmt
, node
->decl
);
4388 ipa_modify_call_arguments (NULL
, stmt
, adjustments
);
4396 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4397 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4400 modify_function (struct cgraph_node
*node
, ipa_parm_adjustment_vec adjustments
)
4402 struct cgraph_node
*new_node
;
4404 VEC (cgraph_edge_p
, heap
) * redirect_callers
= collect_callers_of_node (node
);
4406 rebuild_cgraph_edges ();
4408 current_function_decl
= NULL_TREE
;
4410 new_node
= cgraph_function_versioning (node
, redirect_callers
, NULL
, NULL
,
4411 NULL
, NULL
, "isra");
4412 current_function_decl
= new_node
->decl
;
4413 push_cfun (DECL_STRUCT_FUNCTION (new_node
->decl
));
4415 ipa_modify_formal_parameters (current_function_decl
, adjustments
, "ISRA");
4416 cfg_changed
= ipa_sra_modify_function_body (adjustments
);
4417 sra_ipa_reset_debug_stmts (adjustments
);
4418 convert_callers (new_node
, node
->decl
, adjustments
);
4419 cgraph_make_node_local (new_node
);
4423 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4424 attributes, return true otherwise. NODE is the cgraph node of the current
4428 ipa_sra_preliminary_function_checks (struct cgraph_node
*node
)
4430 if (!cgraph_node_can_be_local_p (node
))
4433 fprintf (dump_file
, "Function not local to this compilation unit.\n");
4437 if (!node
->local
.can_change_signature
)
4440 fprintf (dump_file
, "Function can not change signature.\n");
4444 if (!tree_versionable_function_p (node
->decl
))
4447 fprintf (dump_file
, "Function is not versionable.\n");
4451 if (DECL_VIRTUAL_P (current_function_decl
))
4454 fprintf (dump_file
, "Function is a virtual method.\n");
4458 if ((DECL_COMDAT (node
->decl
) || DECL_EXTERNAL (node
->decl
))
4459 && inline_summary(node
)->size
>= MAX_INLINE_INSNS_AUTO
)
4462 fprintf (dump_file
, "Function too big to be made truly local.\n");
4470 "Function has no callers in this compilation unit.\n");
4477 fprintf (dump_file
, "Function uses stdarg. \n");
4481 if (TYPE_ATTRIBUTES (TREE_TYPE (node
->decl
)))
4487 /* Perform early interprocedural SRA. */
4490 ipa_early_sra (void)
4492 struct cgraph_node
*node
= cgraph_get_node (current_function_decl
);
4493 ipa_parm_adjustment_vec adjustments
;
4496 if (!ipa_sra_preliminary_function_checks (node
))
4500 sra_mode
= SRA_MODE_EARLY_IPA
;
4502 if (!find_param_candidates ())
4505 fprintf (dump_file
, "Function has no IPA-SRA candidates.\n");
4509 if (cgraph_for_node_and_aliases (node
, not_all_callers_have_enough_arguments_p
,
4513 fprintf (dump_file
, "There are callers with insufficient number of "
4518 bb_dereferences
= XCNEWVEC (HOST_WIDE_INT
,
4520 * last_basic_block_for_function (cfun
));
4521 final_bbs
= BITMAP_ALLOC (NULL
);
4524 if (encountered_apply_args
)
4527 fprintf (dump_file
, "Function calls __builtin_apply_args().\n");
4531 if (encountered_unchangable_recursive_call
)
4534 fprintf (dump_file
, "Function calls itself with insufficient "
4535 "number of arguments.\n");
4539 adjustments
= analyze_all_param_acesses ();
4543 ipa_dump_param_adjustments (dump_file
, adjustments
, current_function_decl
);
4545 if (modify_function (node
, adjustments
))
4546 ret
= TODO_update_ssa
| TODO_cleanup_cfg
;
4548 ret
= TODO_update_ssa
;
4549 VEC_free (ipa_parm_adjustment_t
, heap
, adjustments
);
4551 statistics_counter_event (cfun
, "Unused parameters deleted",
4552 sra_stats
.deleted_unused_parameters
);
4553 statistics_counter_event (cfun
, "Scalar parameters converted to by-value",
4554 sra_stats
.scalar_by_ref_to_by_val
);
4555 statistics_counter_event (cfun
, "Aggregate parameters broken up",
4556 sra_stats
.aggregate_params_reduced
);
4557 statistics_counter_event (cfun
, "Aggregate parameter components created",
4558 sra_stats
.param_reductions_created
);
4561 BITMAP_FREE (final_bbs
);
4562 free (bb_dereferences
);
4564 sra_deinitialize ();
4568 /* Return if early ipa sra shall be performed. */
4570 ipa_early_sra_gate (void)
4572 return flag_ipa_sra
&& dbg_cnt (eipa_sra
);
4575 struct gimple_opt_pass pass_early_ipa_sra
=
4579 "eipa_sra", /* name */
4580 ipa_early_sra_gate
, /* gate */
4581 ipa_early_sra
, /* execute */
4584 0, /* static_pass_number */
4585 TV_IPA_SRA
, /* tv_id */
4586 0, /* properties_required */
4587 0, /* properties_provided */
4588 0, /* properties_destroyed */
4589 0, /* todo_flags_start */
4590 TODO_dump_cgraph
/* todo_flags_finish */