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, 2011 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 access to a non-addressable field? */
174 unsigned non_addressable : 1;
176 /* Is this access currently in the work queue? */
177 unsigned grp_queued : 1;
179 /* Does this group contain a write access? This flag is propagated down the
181 unsigned grp_write : 1;
183 /* Does this group contain a read access? This flag is propagated down the
185 unsigned grp_read : 1;
187 /* Does this group contain a read access that comes from an assignment
188 statement? This flag is propagated down the access tree. */
189 unsigned grp_assignment_read : 1;
191 /* Does this group contain a write access that comes from an assignment
192 statement? This flag is propagated down the access tree. */
193 unsigned grp_assignment_write : 1;
195 /* Does this group contain a read access through a scalar type? This flag is
196 not propagated in the access tree in any direction. */
197 unsigned grp_scalar_read : 1;
199 /* Does this group contain a write access through a scalar type? This flag
200 is not propagated in the access tree in any direction. */
201 unsigned grp_scalar_write : 1;
203 /* Is this access an artificial one created to scalarize some record
205 unsigned grp_total_scalarization : 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, ", grp_read = %d, grp_write = %d, grp_assignment_read = %d, "
381 "grp_assignment_write = %d, grp_scalar_read = %d, "
382 "grp_scalar_write = %d, grp_total_scalarization = %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->grp_read, access->grp_write, access->grp_assignment_read,
389 access->grp_assignment_write, access->grp_scalar_read,
390 access->grp_scalar_write, access->grp_total_scalarization,
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, grp_total_scalarization = %d, "
398 "grp_partial_lhs = %d\n",
399 access->write, access->grp_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 true iff ACC is (partly) covered by at least one replacement. */
446 access_has_replacements_p (struct access *acc)
448 struct access *child;
449 if (acc->grp_to_be_replaced)
451 for (child = acc->first_child; child; child = child->next_sibling)
452 if (access_has_replacements_p (child))
457 /* Return a vector of pointers to accesses for the variable given in BASE or
458 NULL if there is none. */
460 static VEC (access_p, heap) *
461 get_base_access_vector (tree base)
465 slot = pointer_map_contains (base_access_vec, base);
469 return *(VEC (access_p, heap) **) slot;
472 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
473 in ACCESS. Return NULL if it cannot be found. */
475 static struct access *
476 find_access_in_subtree (struct access *access, HOST_WIDE_INT offset,
479 while (access && (access->offset != offset || access->size != size))
481 struct access *child = access->first_child;
483 while (child && (child->offset + child->size <= offset))
484 child = child->next_sibling;
491 /* Return the first group representative for DECL or NULL if none exists. */
493 static struct access *
494 get_first_repr_for_decl (tree base)
496 VEC (access_p, heap) *access_vec;
498 access_vec = get_base_access_vector (base);
502 return VEC_index (access_p, access_vec, 0);
505 /* Find an access representative for the variable BASE and given OFFSET and
506 SIZE. Requires that access trees have already been built. Return NULL if
507 it cannot be found. */
509 static struct access *
510 get_var_base_offset_size_access (tree base, HOST_WIDE_INT offset,
513 struct access *access;
515 access = get_first_repr_for_decl (base);
516 while (access && (access->offset + access->size <= offset))
517 access = access->next_grp;
521 return find_access_in_subtree (access, offset, size);
524 /* Add LINK to the linked list of assign links of RACC. */
526 add_link_to_rhs (struct access *racc, struct assign_link *link)
528 gcc_assert (link->racc == racc);
530 if (!racc->first_link)
532 gcc_assert (!racc->last_link);
533 racc->first_link = link;
536 racc->last_link->next = link;
538 racc->last_link = link;
542 /* Move all link structures in their linked list in OLD_RACC to the linked list
545 relink_to_new_repr (struct access *new_racc, struct access *old_racc)
547 if (!old_racc->first_link)
549 gcc_assert (!old_racc->last_link);
553 if (new_racc->first_link)
555 gcc_assert (!new_racc->last_link->next);
556 gcc_assert (!old_racc->last_link || !old_racc->last_link->next);
558 new_racc->last_link->next = old_racc->first_link;
559 new_racc->last_link = old_racc->last_link;
563 gcc_assert (!new_racc->last_link);
565 new_racc->first_link = old_racc->first_link;
566 new_racc->last_link = old_racc->last_link;
568 old_racc->first_link = old_racc->last_link = NULL;
571 /* Add ACCESS to the work queue (which is actually a stack). */
574 add_access_to_work_queue (struct access *access)
576 if (!access->grp_queued)
578 gcc_assert (!access->next_queued);
579 access->next_queued = work_queue_head;
580 access->grp_queued = 1;
581 work_queue_head = access;
585 /* Pop an access from the work queue, and return it, assuming there is one. */
587 static struct access *
588 pop_access_from_work_queue (void)
590 struct access *access = work_queue_head;
592 work_queue_head = access->next_queued;
593 access->next_queued = NULL;
594 access->grp_queued = 0;
599 /* Allocate necessary structures. */
602 sra_initialize (void)
604 candidate_bitmap = BITMAP_ALLOC (NULL);
605 should_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
606 cannot_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
607 gcc_obstack_init (&name_obstack);
608 access_pool = create_alloc_pool ("SRA accesses", sizeof (struct access), 16);
609 link_pool = create_alloc_pool ("SRA links", sizeof (struct assign_link), 16);
610 base_access_vec = pointer_map_create ();
611 memset (&sra_stats, 0, sizeof (sra_stats));
612 encountered_apply_args = false;
613 encountered_recursive_call = false;
614 encountered_unchangable_recursive_call = false;
617 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
620 delete_base_accesses (const void *key ATTRIBUTE_UNUSED, void **value,
621 void *data ATTRIBUTE_UNUSED)
623 VEC (access_p, heap) *access_vec;
624 access_vec = (VEC (access_p, heap) *) *value;
625 VEC_free (access_p, heap, access_vec);
630 /* Deallocate all general structures. */
633 sra_deinitialize (void)
635 BITMAP_FREE (candidate_bitmap);
636 BITMAP_FREE (should_scalarize_away_bitmap);
637 BITMAP_FREE (cannot_scalarize_away_bitmap);
638 free_alloc_pool (access_pool);
639 free_alloc_pool (link_pool);
640 obstack_free (&name_obstack, NULL);
642 pointer_map_traverse (base_access_vec, delete_base_accesses, NULL);
643 pointer_map_destroy (base_access_vec);
646 /* Remove DECL from candidates for SRA and write REASON to the dump file if
649 disqualify_candidate (tree decl, const char *reason)
651 bitmap_clear_bit (candidate_bitmap, DECL_UID (decl));
653 if (dump_file && (dump_flags & TDF_DETAILS))
655 fprintf (dump_file, "! Disqualifying ");
656 print_generic_expr (dump_file, decl, 0);
657 fprintf (dump_file, " - %s\n", reason);
661 /* Return true iff the type contains a field or an element which does not allow
665 type_internals_preclude_sra_p (tree type, const char **msg)
670 switch (TREE_CODE (type))
674 case QUAL_UNION_TYPE:
675 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
676 if (TREE_CODE (fld) == FIELD_DECL)
678 tree ft = TREE_TYPE (fld);
680 if (TREE_THIS_VOLATILE (fld))
682 *msg = "volatile structure field";
685 if (!DECL_FIELD_OFFSET (fld))
687 *msg = "no structure field offset";
690 if (!DECL_SIZE (fld))
692 *msg = "zero structure field size";
695 if (!host_integerp (DECL_FIELD_OFFSET (fld), 1))
697 *msg = "structure field offset not fixed";
700 if (!host_integerp (DECL_SIZE (fld), 1))
702 *msg = "structure field size not fixed";
705 if (AGGREGATE_TYPE_P (ft)
706 && int_bit_position (fld) % BITS_PER_UNIT != 0)
708 *msg = "structure field is bit field";
712 if (AGGREGATE_TYPE_P (ft) && type_internals_preclude_sra_p (ft, msg))
719 et = TREE_TYPE (type);
721 if (TYPE_VOLATILE (et))
723 *msg = "element type is volatile";
727 if (AGGREGATE_TYPE_P (et) && type_internals_preclude_sra_p (et, msg))
737 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
738 base variable if it is. Return T if it is not an SSA_NAME. */
741 get_ssa_base_param (tree t)
743 if (TREE_CODE (t) == SSA_NAME)
745 if (SSA_NAME_IS_DEFAULT_DEF (t))
746 return SSA_NAME_VAR (t);
753 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
754 belongs to, unless the BB has already been marked as a potentially
758 mark_parm_dereference (tree base, HOST_WIDE_INT dist, gimple stmt)
760 basic_block bb = gimple_bb (stmt);
761 int idx, parm_index = 0;
764 if (bitmap_bit_p (final_bbs, bb->index))
767 for (parm = DECL_ARGUMENTS (current_function_decl);
768 parm && parm != base;
769 parm = DECL_CHAIN (parm))
772 gcc_assert (parm_index < func_param_count);
774 idx = bb->index * func_param_count + parm_index;
775 if (bb_dereferences[idx] < dist)
776 bb_dereferences[idx] = dist;
779 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
780 the three fields. Also add it to the vector of accesses corresponding to
781 the base. Finally, return the new access. */
783 static struct access *
784 create_access_1 (tree base, HOST_WIDE_INT offset, HOST_WIDE_INT size)
786 VEC (access_p, heap) *vec;
787 struct access *access;
790 access = (struct access *) pool_alloc (access_pool);
791 memset (access, 0, sizeof (struct access));
793 access->offset = offset;
796 slot = pointer_map_contains (base_access_vec, base);
798 vec = (VEC (access_p, heap) *) *slot;
800 vec = VEC_alloc (access_p, heap, 32);
802 VEC_safe_push (access_p, heap, vec, access);
804 *((struct VEC (access_p,heap) **)
805 pointer_map_insert (base_access_vec, base)) = vec;
810 /* Create and insert access for EXPR. Return created access, or NULL if it is
813 static struct access *
814 create_access (tree expr, gimple stmt, bool write)
816 struct access *access;
817 HOST_WIDE_INT offset, size, max_size;
819 bool ptr, unscalarizable_region = false;
821 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
823 if (sra_mode == SRA_MODE_EARLY_IPA
824 && TREE_CODE (base) == MEM_REF)
826 base = get_ssa_base_param (TREE_OPERAND (base, 0));
834 if (!DECL_P (base) || !bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
837 if (sra_mode == SRA_MODE_EARLY_IPA)
839 if (size < 0 || size != max_size)
841 disqualify_candidate (base, "Encountered a variable sized access.");
844 if (TREE_CODE (expr) == COMPONENT_REF
845 && DECL_BIT_FIELD (TREE_OPERAND (expr, 1)))
847 disqualify_candidate (base, "Encountered a bit-field access.");
850 gcc_checking_assert ((offset % BITS_PER_UNIT) == 0);
853 mark_parm_dereference (base, offset + size, stmt);
857 if (size != max_size)
860 unscalarizable_region = true;
864 disqualify_candidate (base, "Encountered an unconstrained access.");
869 access = create_access_1 (base, offset, size);
871 access->type = TREE_TYPE (expr);
872 access->write = write;
873 access->grp_unscalarizable_region = unscalarizable_region;
876 if (TREE_CODE (expr) == COMPONENT_REF
877 && DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1)))
878 access->non_addressable = 1;
884 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
885 register types or (recursively) records with only these two kinds of fields.
886 It also returns false if any of these records contains a bit-field. */
889 type_consists_of_records_p (tree type)
893 if (TREE_CODE (type) != RECORD_TYPE)
896 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
897 if (TREE_CODE (fld) == FIELD_DECL)
899 tree ft = TREE_TYPE (fld);
901 if (DECL_BIT_FIELD (fld))
904 if (!is_gimple_reg_type (ft)
905 && !type_consists_of_records_p (ft))
912 /* Create total_scalarization accesses for all scalar type fields in DECL that
913 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
914 must be the top-most VAR_DECL representing the variable, OFFSET must be the
915 offset of DECL within BASE. REF must be the memory reference expression for
919 completely_scalarize_record (tree base, tree decl, HOST_WIDE_INT offset,
922 tree fld, decl_type = TREE_TYPE (decl);
924 for (fld = TYPE_FIELDS (decl_type); fld; fld = DECL_CHAIN (fld))
925 if (TREE_CODE (fld) == FIELD_DECL)
927 HOST_WIDE_INT pos = offset + int_bit_position (fld);
928 tree ft = TREE_TYPE (fld);
929 tree nref = build3 (COMPONENT_REF, TREE_TYPE (fld), ref, fld,
932 if (is_gimple_reg_type (ft))
934 struct access *access;
937 size = tree_low_cst (DECL_SIZE (fld), 1);
938 access = create_access_1 (base, pos, size);
941 access->grp_total_scalarization = 1;
942 /* Accesses for intraprocedural SRA can have their stmt NULL. */
945 completely_scalarize_record (base, fld, pos, nref);
949 /* Create total_scalarization accesses for all scalar type fields in VAR and
950 for VAR a a whole. VAR must be of a RECORD_TYPE conforming to
951 type_consists_of_records_p. */
954 completely_scalarize_var (tree var)
956 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (var), 1);
957 struct access *access;
959 access = create_access_1 (var, 0, size);
961 access->type = TREE_TYPE (var);
962 access->grp_total_scalarization = 1;
964 completely_scalarize_record (var, var, 0, var);
967 /* Search the given tree for a declaration by skipping handled components and
968 exclude it from the candidates. */
971 disqualify_base_of_expr (tree t, const char *reason)
973 t = get_base_address (t);
975 && sra_mode == SRA_MODE_EARLY_IPA
976 && TREE_CODE (t) == MEM_REF)
977 t = get_ssa_base_param (TREE_OPERAND (t, 0));
980 disqualify_candidate (t, reason);
983 /* Scan expression EXPR and create access structures for all accesses to
984 candidates for scalarization. Return the created access or NULL if none is
987 static struct access *
988 build_access_from_expr_1 (tree expr, gimple stmt, bool write)
990 struct access *ret = NULL;
993 if (TREE_CODE (expr) == BIT_FIELD_REF
994 || TREE_CODE (expr) == IMAGPART_EXPR
995 || TREE_CODE (expr) == REALPART_EXPR)
997 expr = TREE_OPERAND (expr, 0);
1001 partial_ref = false;
1003 /* We need to dive through V_C_Es in order to get the size of its parameter
1004 and not the result type. Ada produces such statements. We are also
1005 capable of handling the topmost V_C_E but not any of those buried in other
1006 handled components. */
1007 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
1008 expr = TREE_OPERAND (expr, 0);
1010 if (contains_view_convert_expr_p (expr))
1012 disqualify_base_of_expr (expr, "V_C_E under a different handled "
1017 switch (TREE_CODE (expr))
1020 if (TREE_CODE (TREE_OPERAND (expr, 0)) != ADDR_EXPR
1021 && sra_mode != SRA_MODE_EARLY_IPA)
1029 case ARRAY_RANGE_REF:
1030 ret = create_access (expr, stmt, write);
1037 if (write && partial_ref && ret)
1038 ret->grp_partial_lhs = 1;
1043 /* Scan expression EXPR and create access structures for all accesses to
1044 candidates for scalarization. Return true if any access has been inserted.
1045 STMT must be the statement from which the expression is taken, WRITE must be
1046 true if the expression is a store and false otherwise. */
1049 build_access_from_expr (tree expr, gimple stmt, bool write)
1051 struct access *access;
1053 access = build_access_from_expr_1 (expr, stmt, write);
1056 /* This means the aggregate is accesses as a whole in a way other than an
1057 assign statement and thus cannot be removed even if we had a scalar
1058 replacement for everything. */
1059 if (cannot_scalarize_away_bitmap)
1060 bitmap_set_bit (cannot_scalarize_away_bitmap, DECL_UID (access->base));
1066 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
1067 modes in which it matters, return true iff they have been disqualified. RHS
1068 may be NULL, in that case ignore it. If we scalarize an aggregate in
1069 intra-SRA we may need to add statements after each statement. This is not
1070 possible if a statement unconditionally has to end the basic block. */
1072 disqualify_ops_if_throwing_stmt (gimple stmt, tree lhs, tree rhs)
1074 if ((sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1075 && (stmt_can_throw_internal (stmt) || stmt_ends_bb_p (stmt)))
1077 disqualify_base_of_expr (lhs, "LHS of a throwing stmt.");
1079 disqualify_base_of_expr (rhs, "RHS of a throwing stmt.");
1085 /* Return true if EXP is a memory reference less aligned than ALIGN. This is
1086 invoked only on strict-alignment targets. */
1089 tree_non_aligned_mem_p (tree exp, unsigned int align)
1091 unsigned int exp_align;
1093 if (TREE_CODE (exp) == VIEW_CONVERT_EXPR)
1094 exp = TREE_OPERAND (exp, 0);
1096 if (TREE_CODE (exp) == SSA_NAME || is_gimple_min_invariant (exp))
1099 /* get_object_alignment will fall back to BITS_PER_UNIT if it cannot
1100 compute an explicit alignment. Pretend that dereferenced pointers
1101 are always aligned on strict-alignment targets. */
1102 if (TREE_CODE (exp) == MEM_REF || TREE_CODE (exp) == TARGET_MEM_REF)
1103 exp_align = get_object_or_type_alignment (exp);
1105 exp_align = get_object_alignment (exp);
1107 if (exp_align < align)
1113 /* Return true if EXP is a memory reference less aligned than what the access
1114 ACC would require. This is invoked only on strict-alignment targets. */
1117 tree_non_aligned_mem_for_access_p (tree exp, struct access *acc)
1119 unsigned int acc_align;
1121 /* The alignment of the access is that of its expression. However, it may
1122 have been artificially increased, e.g. by a local alignment promotion,
1123 so we cap it to the alignment of the type of the base, on the grounds
1124 that valid sub-accesses cannot be more aligned than that. */
1125 acc_align = get_object_alignment (acc->expr);
1126 if (acc->base && acc_align > TYPE_ALIGN (TREE_TYPE (acc->base)))
1127 acc_align = TYPE_ALIGN (TREE_TYPE (acc->base));
1129 return tree_non_aligned_mem_p (exp, acc_align);
1132 /* Scan expressions occuring in STMT, create access structures for all accesses
1133 to candidates for scalarization and remove those candidates which occur in
1134 statements or expressions that prevent them from being split apart. Return
1135 true if any access has been inserted. */
1138 build_accesses_from_assign (gimple stmt)
1141 struct access *lacc, *racc;
1143 if (!gimple_assign_single_p (stmt)
1144 /* Scope clobbers don't influence scalarization. */
1145 || gimple_clobber_p (stmt))
1148 lhs = gimple_assign_lhs (stmt);
1149 rhs = gimple_assign_rhs1 (stmt);
1151 if (disqualify_ops_if_throwing_stmt (stmt, lhs, rhs))
1154 racc = build_access_from_expr_1 (rhs, stmt, false);
1155 lacc = build_access_from_expr_1 (lhs, stmt, true);
1159 lacc->grp_assignment_write = 1;
1160 if (STRICT_ALIGNMENT && tree_non_aligned_mem_for_access_p (rhs, lacc))
1161 lacc->grp_unscalarizable_region = 1;
1166 racc->grp_assignment_read = 1;
1167 if (should_scalarize_away_bitmap && !gimple_has_volatile_ops (stmt)
1168 && !is_gimple_reg_type (racc->type))
1169 bitmap_set_bit (should_scalarize_away_bitmap, DECL_UID (racc->base));
1170 if (STRICT_ALIGNMENT && tree_non_aligned_mem_for_access_p (lhs, racc))
1171 racc->grp_unscalarizable_region = 1;
1175 && (sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1176 && !lacc->grp_unscalarizable_region
1177 && !racc->grp_unscalarizable_region
1178 && AGGREGATE_TYPE_P (TREE_TYPE (lhs))
1179 /* FIXME: Turn the following line into an assert after PR 40058 is
1181 && lacc->size == racc->size
1182 && useless_type_conversion_p (lacc->type, racc->type))
1184 struct assign_link *link;
1186 link = (struct assign_link *) pool_alloc (link_pool);
1187 memset (link, 0, sizeof (struct assign_link));
1192 add_link_to_rhs (racc, link);
1195 return lacc || racc;
1198 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1199 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1202 asm_visit_addr (gimple stmt ATTRIBUTE_UNUSED, tree op,
1203 void *data ATTRIBUTE_UNUSED)
1205 op = get_base_address (op);
1208 disqualify_candidate (op, "Non-scalarizable GIMPLE_ASM operand.");
1213 /* Return true iff callsite CALL has at least as many actual arguments as there
1214 are formal parameters of the function currently processed by IPA-SRA. */
1217 callsite_has_enough_arguments_p (gimple call)
1219 return gimple_call_num_args (call) >= (unsigned) func_param_count;
1222 /* Scan function and look for interesting expressions and create access
1223 structures for them. Return true iff any access is created. */
1226 scan_function (void)
1233 gimple_stmt_iterator gsi;
1234 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1236 gimple stmt = gsi_stmt (gsi);
1240 if (final_bbs && stmt_can_throw_external (stmt))
1241 bitmap_set_bit (final_bbs, bb->index);
1242 switch (gimple_code (stmt))
1245 t = gimple_return_retval (stmt);
1247 ret |= build_access_from_expr (t, stmt, false);
1249 bitmap_set_bit (final_bbs, bb->index);
1253 ret |= build_accesses_from_assign (stmt);
1257 for (i = 0; i < gimple_call_num_args (stmt); i++)
1258 ret |= build_access_from_expr (gimple_call_arg (stmt, i),
1261 if (sra_mode == SRA_MODE_EARLY_IPA)
1263 tree dest = gimple_call_fndecl (stmt);
1264 int flags = gimple_call_flags (stmt);
1268 if (DECL_BUILT_IN_CLASS (dest) == BUILT_IN_NORMAL
1269 && DECL_FUNCTION_CODE (dest) == BUILT_IN_APPLY_ARGS)
1270 encountered_apply_args = true;
1271 if (cgraph_get_node (dest)
1272 == cgraph_get_node (current_function_decl))
1274 encountered_recursive_call = true;
1275 if (!callsite_has_enough_arguments_p (stmt))
1276 encountered_unchangable_recursive_call = true;
1281 && (flags & (ECF_CONST | ECF_PURE)) == 0)
1282 bitmap_set_bit (final_bbs, bb->index);
1285 t = gimple_call_lhs (stmt);
1286 if (t && !disqualify_ops_if_throwing_stmt (stmt, t, NULL))
1287 ret |= build_access_from_expr (t, stmt, true);
1291 walk_stmt_load_store_addr_ops (stmt, NULL, NULL, NULL,
1294 bitmap_set_bit (final_bbs, bb->index);
1296 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
1298 t = TREE_VALUE (gimple_asm_input_op (stmt, i));
1299 ret |= build_access_from_expr (t, stmt, false);
1301 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
1303 t = TREE_VALUE (gimple_asm_output_op (stmt, i));
1304 ret |= build_access_from_expr (t, stmt, true);
1317 /* Helper of QSORT function. There are pointers to accesses in the array. An
1318 access is considered smaller than another if it has smaller offset or if the
1319 offsets are the same but is size is bigger. */
1322 compare_access_positions (const void *a, const void *b)
1324 const access_p *fp1 = (const access_p *) a;
1325 const access_p *fp2 = (const access_p *) b;
1326 const access_p f1 = *fp1;
1327 const access_p f2 = *fp2;
1329 if (f1->offset != f2->offset)
1330 return f1->offset < f2->offset ? -1 : 1;
1332 if (f1->size == f2->size)
1334 if (f1->type == f2->type)
1336 /* Put any non-aggregate type before any aggregate type. */
1337 else if (!is_gimple_reg_type (f1->type)
1338 && is_gimple_reg_type (f2->type))
1340 else if (is_gimple_reg_type (f1->type)
1341 && !is_gimple_reg_type (f2->type))
1343 /* Put any complex or vector type before any other scalar type. */
1344 else if (TREE_CODE (f1->type) != COMPLEX_TYPE
1345 && TREE_CODE (f1->type) != VECTOR_TYPE
1346 && (TREE_CODE (f2->type) == COMPLEX_TYPE
1347 || TREE_CODE (f2->type) == VECTOR_TYPE))
1349 else if ((TREE_CODE (f1->type) == COMPLEX_TYPE
1350 || TREE_CODE (f1->type) == VECTOR_TYPE)
1351 && TREE_CODE (f2->type) != COMPLEX_TYPE
1352 && TREE_CODE (f2->type) != VECTOR_TYPE)
1354 /* Put the integral type with the bigger precision first. */
1355 else if (INTEGRAL_TYPE_P (f1->type)
1356 && INTEGRAL_TYPE_P (f2->type))
1357 return TYPE_PRECISION (f2->type) - TYPE_PRECISION (f1->type);
1358 /* Put any integral type with non-full precision last. */
1359 else if (INTEGRAL_TYPE_P (f1->type)
1360 && (TREE_INT_CST_LOW (TYPE_SIZE (f1->type))
1361 != TYPE_PRECISION (f1->type)))
1363 else if (INTEGRAL_TYPE_P (f2->type)
1364 && (TREE_INT_CST_LOW (TYPE_SIZE (f2->type))
1365 != TYPE_PRECISION (f2->type)))
1367 /* Stabilize the sort. */
1368 return TYPE_UID (f1->type) - TYPE_UID (f2->type);
1371 /* We want the bigger accesses first, thus the opposite operator in the next
1373 return f1->size > f2->size ? -1 : 1;
1377 /* Append a name of the declaration to the name obstack. A helper function for
1381 make_fancy_decl_name (tree decl)
1385 tree name = DECL_NAME (decl);
1387 obstack_grow (&name_obstack, IDENTIFIER_POINTER (name),
1388 IDENTIFIER_LENGTH (name));
1391 sprintf (buffer, "D%u", DECL_UID (decl));
1392 obstack_grow (&name_obstack, buffer, strlen (buffer));
1396 /* Helper for make_fancy_name. */
1399 make_fancy_name_1 (tree expr)
1406 make_fancy_decl_name (expr);
1410 switch (TREE_CODE (expr))
1413 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1414 obstack_1grow (&name_obstack, '$');
1415 make_fancy_decl_name (TREE_OPERAND (expr, 1));
1419 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1420 obstack_1grow (&name_obstack, '$');
1421 /* Arrays with only one element may not have a constant as their
1423 index = TREE_OPERAND (expr, 1);
1424 if (TREE_CODE (index) != INTEGER_CST)
1426 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC, TREE_INT_CST_LOW (index));
1427 obstack_grow (&name_obstack, buffer, strlen (buffer));
1431 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1435 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1436 if (!integer_zerop (TREE_OPERAND (expr, 1)))
1438 obstack_1grow (&name_obstack, '$');
1439 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC,
1440 TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)));
1441 obstack_grow (&name_obstack, buffer, strlen (buffer));
1448 gcc_unreachable (); /* we treat these as scalars. */
1455 /* Create a human readable name for replacement variable of ACCESS. */
1458 make_fancy_name (tree expr)
1460 make_fancy_name_1 (expr);
1461 obstack_1grow (&name_obstack, '\0');
1462 return XOBFINISH (&name_obstack, char *);
1465 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1466 EXP_TYPE at the given OFFSET. If BASE is something for which
1467 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1468 to insert new statements either before or below the current one as specified
1469 by INSERT_AFTER. This function is not capable of handling bitfields. */
1472 build_ref_for_offset (location_t loc, tree base, HOST_WIDE_INT offset,
1473 tree exp_type, gimple_stmt_iterator *gsi,
1476 tree prev_base = base;
1478 HOST_WIDE_INT base_offset;
1479 unsigned HOST_WIDE_INT misalign;
1482 gcc_checking_assert (offset % BITS_PER_UNIT == 0);
1484 base = get_addr_base_and_unit_offset (base, &base_offset);
1486 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1487 offset such as array[var_index]. */
1493 gcc_checking_assert (gsi);
1494 tmp = create_tmp_reg (build_pointer_type (TREE_TYPE (prev_base)), NULL);
1495 add_referenced_var (tmp);
1496 tmp = make_ssa_name (tmp, NULL);
1497 addr = build_fold_addr_expr (unshare_expr (prev_base));
1498 STRIP_USELESS_TYPE_CONVERSION (addr);
1499 stmt = gimple_build_assign (tmp, addr);
1500 gimple_set_location (stmt, loc);
1501 SSA_NAME_DEF_STMT (tmp) = stmt;
1503 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
1505 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1508 off = build_int_cst (reference_alias_ptr_type (prev_base),
1509 offset / BITS_PER_UNIT);
1512 else if (TREE_CODE (base) == MEM_REF)
1514 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1515 base_offset + offset / BITS_PER_UNIT);
1516 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off);
1517 base = unshare_expr (TREE_OPERAND (base, 0));
1521 off = build_int_cst (reference_alias_ptr_type (base),
1522 base_offset + offset / BITS_PER_UNIT);
1523 base = build_fold_addr_expr (unshare_expr (base));
1526 /* If prev_base were always an originally performed access
1527 we can extract more optimistic alignment information
1528 by looking at the access mode. That would constrain the
1529 alignment of base + base_offset which we would need to
1530 adjust according to offset. */
1531 align = get_pointer_alignment_1 (base, &misalign);
1533 && (TREE_CODE (prev_base) == MEM_REF
1534 || TREE_CODE (prev_base) == TARGET_MEM_REF))
1535 align = MAX (align, TYPE_ALIGN (TREE_TYPE (prev_base)));
1536 misalign += (double_int_sext (tree_to_double_int (off),
1537 TYPE_PRECISION (TREE_TYPE (off))).low
1539 misalign = misalign & (align - 1);
1541 align = (misalign & -misalign);
1542 if (align < TYPE_ALIGN (exp_type))
1543 exp_type = build_aligned_type (exp_type, align);
1545 return fold_build2_loc (loc, MEM_REF, exp_type, base, off);
1548 DEF_VEC_ALLOC_P_STACK (tree);
1549 #define VEC_tree_stack_alloc(alloc) VEC_stack_alloc (tree, alloc)
1551 /* Construct a memory reference to a part of an aggregate BASE at the given
1552 OFFSET and of the type of MODEL. In case this is a chain of references
1553 to component, the function will replicate the chain of COMPONENT_REFs of
1554 the expression of MODEL to access it. GSI and INSERT_AFTER have the same
1555 meaning as in build_ref_for_offset. */
1558 build_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1559 struct access *model, gimple_stmt_iterator *gsi,
1562 tree type = model->type, t;
1563 VEC(tree,stack) *cr_stack = NULL;
1565 if (TREE_CODE (model->expr) == COMPONENT_REF)
1567 tree expr = model->expr;
1569 /* Create a stack of the COMPONENT_REFs so later we can walk them in
1570 order from inner to outer. */
1571 cr_stack = VEC_alloc (tree, stack, 6);
1574 tree field = TREE_OPERAND (expr, 1);
1575 tree cr_offset = component_ref_field_offset (expr);
1576 HOST_WIDE_INT bit_pos
1577 = tree_low_cst (cr_offset, 1) * BITS_PER_UNIT
1578 + TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field));
1580 /* We can be called with a model different from the one associated
1581 with BASE so we need to avoid going up the chain too far. */
1582 if (offset - bit_pos < 0)
1586 VEC_safe_push (tree, stack, cr_stack, expr);
1588 expr = TREE_OPERAND (expr, 0);
1589 type = TREE_TYPE (expr);
1590 } while (TREE_CODE (expr) == COMPONENT_REF);
1593 t = build_ref_for_offset (loc, base, offset, type, gsi, insert_after);
1595 if (TREE_CODE (model->expr) == COMPONENT_REF)
1600 /* Now replicate the chain of COMPONENT_REFs from inner to outer. */
1601 FOR_EACH_VEC_ELT_REVERSE (tree, cr_stack, i, expr)
1603 tree field = TREE_OPERAND (expr, 1);
1604 t = fold_build3_loc (loc, COMPONENT_REF, TREE_TYPE (field), t, field,
1605 TREE_OPERAND (expr, 2));
1608 VEC_free (tree, stack, cr_stack);
1614 /* Construct a memory reference consisting of component_refs and array_refs to
1615 a part of an aggregate *RES (which is of type TYPE). The requested part
1616 should have type EXP_TYPE at be the given OFFSET. This function might not
1617 succeed, it returns true when it does and only then *RES points to something
1618 meaningful. This function should be used only to build expressions that we
1619 might need to present to user (e.g. in warnings). In all other situations,
1620 build_ref_for_model or build_ref_for_offset should be used instead. */
1623 build_user_friendly_ref_for_offset (tree *res, tree type, HOST_WIDE_INT offset,
1629 tree tr_size, index, minidx;
1630 HOST_WIDE_INT el_size;
1632 if (offset == 0 && exp_type
1633 && types_compatible_p (exp_type, type))
1636 switch (TREE_CODE (type))
1639 case QUAL_UNION_TYPE:
1641 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
1643 HOST_WIDE_INT pos, size;
1644 tree expr, *expr_ptr;
1646 if (TREE_CODE (fld) != FIELD_DECL)
1649 pos = int_bit_position (fld);
1650 gcc_assert (TREE_CODE (type) == RECORD_TYPE || pos == 0);
1651 tr_size = DECL_SIZE (fld);
1652 if (!tr_size || !host_integerp (tr_size, 1))
1654 size = tree_low_cst (tr_size, 1);
1660 else if (pos > offset || (pos + size) <= offset)
1663 expr = build3 (COMPONENT_REF, TREE_TYPE (fld), *res, fld,
1666 if (build_user_friendly_ref_for_offset (expr_ptr, TREE_TYPE (fld),
1667 offset - pos, exp_type))
1676 tr_size = TYPE_SIZE (TREE_TYPE (type));
1677 if (!tr_size || !host_integerp (tr_size, 1))
1679 el_size = tree_low_cst (tr_size, 1);
1681 minidx = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
1682 if (TREE_CODE (minidx) != INTEGER_CST || el_size == 0)
1684 index = build_int_cst (TYPE_DOMAIN (type), offset / el_size);
1685 if (!integer_zerop (minidx))
1686 index = int_const_binop (PLUS_EXPR, index, minidx);
1687 *res = build4 (ARRAY_REF, TREE_TYPE (type), *res, index,
1688 NULL_TREE, NULL_TREE);
1689 offset = offset % el_size;
1690 type = TREE_TYPE (type);
1705 /* Return true iff TYPE is stdarg va_list type. */
1708 is_va_list_type (tree type)
1710 return TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (va_list_type_node);
1713 /* Print message to dump file why a variable was rejected. */
1716 reject (tree var, const char *msg)
1718 if (dump_file && (dump_flags & TDF_DETAILS))
1720 fprintf (dump_file, "Rejected (%d): %s: ", DECL_UID (var), msg);
1721 print_generic_expr (dump_file, var, 0);
1722 fprintf (dump_file, "\n");
1726 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1727 those with type which is suitable for scalarization. */
1730 find_var_candidates (void)
1733 referenced_var_iterator rvi;
1737 FOR_EACH_REFERENCED_VAR (cfun, var, rvi)
1739 if (TREE_CODE (var) != VAR_DECL && TREE_CODE (var) != PARM_DECL)
1741 type = TREE_TYPE (var);
1743 if (!AGGREGATE_TYPE_P (type))
1745 reject (var, "not aggregate");
1748 if (needs_to_live_in_memory (var))
1750 reject (var, "needs to live in memory");
1753 if (TREE_THIS_VOLATILE (var))
1755 reject (var, "is volatile");
1758 if (!COMPLETE_TYPE_P (type))
1760 reject (var, "has incomplete type");
1763 if (!host_integerp (TYPE_SIZE (type), 1))
1765 reject (var, "type size not fixed");
1768 if (tree_low_cst (TYPE_SIZE (type), 1) == 0)
1770 reject (var, "type size is zero");
1773 if (type_internals_preclude_sra_p (type, &msg))
1778 if (/* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1779 we also want to schedule it rather late. Thus we ignore it in
1781 (sra_mode == SRA_MODE_EARLY_INTRA
1782 && is_va_list_type (type)))
1784 reject (var, "is va_list");
1788 bitmap_set_bit (candidate_bitmap, DECL_UID (var));
1790 if (dump_file && (dump_flags & TDF_DETAILS))
1792 fprintf (dump_file, "Candidate (%d): ", DECL_UID (var));
1793 print_generic_expr (dump_file, var, 0);
1794 fprintf (dump_file, "\n");
1802 /* Sort all accesses for the given variable, check for partial overlaps and
1803 return NULL if there are any. If there are none, pick a representative for
1804 each combination of offset and size and create a linked list out of them.
1805 Return the pointer to the first representative and make sure it is the first
1806 one in the vector of accesses. */
1808 static struct access *
1809 sort_and_splice_var_accesses (tree var)
1811 int i, j, access_count;
1812 struct access *res, **prev_acc_ptr = &res;
1813 VEC (access_p, heap) *access_vec;
1815 HOST_WIDE_INT low = -1, high = 0;
1817 access_vec = get_base_access_vector (var);
1820 access_count = VEC_length (access_p, access_vec);
1822 /* Sort by <OFFSET, SIZE>. */
1823 VEC_qsort (access_p, access_vec, compare_access_positions);
1826 while (i < access_count)
1828 struct access *access = VEC_index (access_p, access_vec, i);
1829 bool grp_write = access->write;
1830 bool grp_read = !access->write;
1831 bool grp_scalar_write = access->write
1832 && is_gimple_reg_type (access->type);
1833 bool grp_scalar_read = !access->write
1834 && is_gimple_reg_type (access->type);
1835 bool grp_assignment_read = access->grp_assignment_read;
1836 bool grp_assignment_write = access->grp_assignment_write;
1837 bool multiple_scalar_reads = false;
1838 bool total_scalarization = access->grp_total_scalarization;
1839 bool grp_partial_lhs = access->grp_partial_lhs;
1840 bool first_scalar = is_gimple_reg_type (access->type);
1841 bool unscalarizable_region = access->grp_unscalarizable_region;
1843 if (first || access->offset >= high)
1846 low = access->offset;
1847 high = access->offset + access->size;
1849 else if (access->offset > low && access->offset + access->size > high)
1852 gcc_assert (access->offset >= low
1853 && access->offset + access->size <= high);
1856 while (j < access_count)
1858 struct access *ac2 = VEC_index (access_p, access_vec, j);
1859 if (ac2->offset != access->offset || ac2->size != access->size)
1864 grp_scalar_write = (grp_scalar_write
1865 || is_gimple_reg_type (ac2->type));
1870 if (is_gimple_reg_type (ac2->type))
1872 if (grp_scalar_read)
1873 multiple_scalar_reads = true;
1875 grp_scalar_read = true;
1878 grp_assignment_read |= ac2->grp_assignment_read;
1879 grp_assignment_write |= ac2->grp_assignment_write;
1880 grp_partial_lhs |= ac2->grp_partial_lhs;
1881 unscalarizable_region |= ac2->grp_unscalarizable_region;
1882 total_scalarization |= ac2->grp_total_scalarization;
1883 relink_to_new_repr (access, ac2);
1885 /* If there are both aggregate-type and scalar-type accesses with
1886 this combination of size and offset, the comparison function
1887 should have put the scalars first. */
1888 gcc_assert (first_scalar || !is_gimple_reg_type (ac2->type));
1889 ac2->group_representative = access;
1895 access->group_representative = access;
1896 access->grp_write = grp_write;
1897 access->grp_read = grp_read;
1898 access->grp_scalar_read = grp_scalar_read;
1899 access->grp_scalar_write = grp_scalar_write;
1900 access->grp_assignment_read = grp_assignment_read;
1901 access->grp_assignment_write = grp_assignment_write;
1902 access->grp_hint = multiple_scalar_reads || total_scalarization;
1903 access->grp_total_scalarization = total_scalarization;
1904 access->grp_partial_lhs = grp_partial_lhs;
1905 access->grp_unscalarizable_region = unscalarizable_region;
1906 if (access->first_link)
1907 add_access_to_work_queue (access);
1909 *prev_acc_ptr = access;
1910 prev_acc_ptr = &access->next_grp;
1913 gcc_assert (res == VEC_index (access_p, access_vec, 0));
1917 /* Create a variable for the given ACCESS which determines the type, name and a
1918 few other properties. Return the variable declaration and store it also to
1919 ACCESS->replacement. */
1922 create_access_replacement (struct access *access, bool rename)
1926 repl = create_tmp_var (access->type, "SR");
1927 add_referenced_var (repl);
1929 mark_sym_for_renaming (repl);
1931 if (!access->grp_partial_lhs
1932 && (TREE_CODE (access->type) == COMPLEX_TYPE
1933 || TREE_CODE (access->type) == VECTOR_TYPE))
1934 DECL_GIMPLE_REG_P (repl) = 1;
1936 DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
1937 DECL_ARTIFICIAL (repl) = 1;
1938 DECL_IGNORED_P (repl) = DECL_IGNORED_P (access->base);
1940 if (DECL_NAME (access->base)
1941 && !DECL_IGNORED_P (access->base)
1942 && !DECL_ARTIFICIAL (access->base))
1944 char *pretty_name = make_fancy_name (access->expr);
1945 tree debug_expr = unshare_expr (access->expr), d;
1947 DECL_NAME (repl) = get_identifier (pretty_name);
1948 obstack_free (&name_obstack, pretty_name);
1950 /* Get rid of any SSA_NAMEs embedded in debug_expr,
1951 as DECL_DEBUG_EXPR isn't considered when looking for still
1952 used SSA_NAMEs and thus they could be freed. All debug info
1953 generation cares is whether something is constant or variable
1954 and that get_ref_base_and_extent works properly on the
1956 for (d = debug_expr; handled_component_p (d); d = TREE_OPERAND (d, 0))
1957 switch (TREE_CODE (d))
1960 case ARRAY_RANGE_REF:
1961 if (TREE_OPERAND (d, 1)
1962 && TREE_CODE (TREE_OPERAND (d, 1)) == SSA_NAME)
1963 TREE_OPERAND (d, 1) = SSA_NAME_VAR (TREE_OPERAND (d, 1));
1964 if (TREE_OPERAND (d, 3)
1965 && TREE_CODE (TREE_OPERAND (d, 3)) == SSA_NAME)
1966 TREE_OPERAND (d, 3) = SSA_NAME_VAR (TREE_OPERAND (d, 3));
1969 if (TREE_OPERAND (d, 2)
1970 && TREE_CODE (TREE_OPERAND (d, 2)) == SSA_NAME)
1971 TREE_OPERAND (d, 2) = SSA_NAME_VAR (TREE_OPERAND (d, 2));
1976 SET_DECL_DEBUG_EXPR (repl, debug_expr);
1977 DECL_DEBUG_EXPR_IS_FROM (repl) = 1;
1978 if (access->grp_no_warning)
1979 TREE_NO_WARNING (repl) = 1;
1981 TREE_NO_WARNING (repl) = TREE_NO_WARNING (access->base);
1984 TREE_NO_WARNING (repl) = 1;
1988 fprintf (dump_file, "Created a replacement for ");
1989 print_generic_expr (dump_file, access->base, 0);
1990 fprintf (dump_file, " offset: %u, size: %u: ",
1991 (unsigned) access->offset, (unsigned) access->size);
1992 print_generic_expr (dump_file, repl, 0);
1993 fprintf (dump_file, "\n");
1995 sra_stats.replacements++;
2000 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
2003 get_access_replacement (struct access *access)
2005 gcc_assert (access->grp_to_be_replaced);
2007 if (!access->replacement_decl)
2008 access->replacement_decl = create_access_replacement (access, true);
2009 return access->replacement_decl;
2012 /* Return ACCESS scalar replacement, create it if it does not exist yet but do
2013 not mark it for renaming. */
2016 get_unrenamed_access_replacement (struct access *access)
2018 gcc_assert (!access->grp_to_be_replaced);
2020 if (!access->replacement_decl)
2021 access->replacement_decl = create_access_replacement (access, false);
2022 return access->replacement_decl;
2026 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
2027 linked list along the way. Stop when *ACCESS is NULL or the access pointed
2028 to it is not "within" the root. Return false iff some accesses partially
2032 build_access_subtree (struct access **access)
2034 struct access *root = *access, *last_child = NULL;
2035 HOST_WIDE_INT limit = root->offset + root->size;
2037 *access = (*access)->next_grp;
2038 while (*access && (*access)->offset + (*access)->size <= limit)
2041 root->first_child = *access;
2043 last_child->next_sibling = *access;
2044 last_child = *access;
2046 if (!build_access_subtree (access))
2050 if (*access && (*access)->offset < limit)
2056 /* Build a tree of access representatives, ACCESS is the pointer to the first
2057 one, others are linked in a list by the next_grp field. Return false iff
2058 some accesses partially overlap. */
2061 build_access_trees (struct access *access)
2065 struct access *root = access;
2067 if (!build_access_subtree (&access))
2069 root->next_grp = access;
2074 /* Return true if expr contains some ARRAY_REFs into a variable bounded
2078 expr_with_var_bounded_array_refs_p (tree expr)
2080 while (handled_component_p (expr))
2082 if (TREE_CODE (expr) == ARRAY_REF
2083 && !host_integerp (array_ref_low_bound (expr), 0))
2085 expr = TREE_OPERAND (expr, 0);
2090 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
2091 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
2092 sorts of access flags appropriately along the way, notably always set
2093 grp_read and grp_assign_read according to MARK_READ and grp_write when
2096 Creating a replacement for a scalar access is considered beneficial if its
2097 grp_hint is set (this means we are either attempting total scalarization or
2098 there is more than one direct read access) or according to the following
2101 Access written to through a scalar type (once or more times)
2103 | Written to in an assignment statement
2105 | | Access read as scalar _once_
2107 | | | Read in an assignment statement
2109 | | | | Scalarize Comment
2110 -----------------------------------------------------------------------------
2111 0 0 0 0 No access for the scalar
2112 0 0 0 1 No access for the scalar
2113 0 0 1 0 No Single read - won't help
2114 0 0 1 1 No The same case
2115 0 1 0 0 No access for the scalar
2116 0 1 0 1 No access for the scalar
2117 0 1 1 0 Yes s = *g; return s.i;
2118 0 1 1 1 Yes The same case as above
2119 1 0 0 0 No Won't help
2120 1 0 0 1 Yes s.i = 1; *g = s;
2121 1 0 1 0 Yes s.i = 5; g = s.i;
2122 1 0 1 1 Yes The same case as above
2123 1 1 0 0 No Won't help.
2124 1 1 0 1 Yes s.i = 1; *g = s;
2125 1 1 1 0 Yes s = *g; return s.i;
2126 1 1 1 1 Yes Any of the above yeses */
2129 analyze_access_subtree (struct access *root, struct access *parent,
2130 bool allow_replacements)
2132 struct access *child;
2133 HOST_WIDE_INT limit = root->offset + root->size;
2134 HOST_WIDE_INT covered_to = root->offset;
2135 bool scalar = is_gimple_reg_type (root->type);
2136 bool hole = false, sth_created = false;
2140 if (parent->grp_read)
2142 if (parent->grp_assignment_read)
2143 root->grp_assignment_read = 1;
2144 if (parent->grp_write)
2145 root->grp_write = 1;
2146 if (parent->grp_assignment_write)
2147 root->grp_assignment_write = 1;
2148 if (parent->grp_total_scalarization)
2149 root->grp_total_scalarization = 1;
2152 if (root->grp_unscalarizable_region)
2153 allow_replacements = false;
2155 if (allow_replacements && expr_with_var_bounded_array_refs_p (root->expr))
2156 allow_replacements = false;
2158 for (child = root->first_child; child; child = child->next_sibling)
2160 hole |= covered_to < child->offset;
2161 sth_created |= analyze_access_subtree (child, root,
2162 allow_replacements && !scalar);
2164 root->grp_unscalarized_data |= child->grp_unscalarized_data;
2165 root->grp_total_scalarization &= child->grp_total_scalarization;
2166 if (child->grp_covered)
2167 covered_to += child->size;
2172 if (allow_replacements && scalar && !root->first_child
2174 || ((root->grp_scalar_read || root->grp_assignment_read)
2175 && (root->grp_scalar_write || root->grp_assignment_write))))
2177 bool new_integer_type;
2178 /* Always create access replacements that cover the whole access.
2179 For integral types this means the precision has to match.
2180 Avoid assumptions based on the integral type kind, too. */
2181 if (INTEGRAL_TYPE_P (root->type)
2182 && (TREE_CODE (root->type) != INTEGER_TYPE
2183 || TYPE_PRECISION (root->type) != root->size)
2184 /* But leave bitfield accesses alone. */
2185 && (TREE_CODE (root->expr) != COMPONENT_REF
2186 || !DECL_BIT_FIELD (TREE_OPERAND (root->expr, 1))))
2188 tree rt = root->type;
2189 gcc_assert ((root->offset % BITS_PER_UNIT) == 0
2190 && (root->size % BITS_PER_UNIT) == 0);
2191 root->type = build_nonstandard_integer_type (root->size,
2192 TYPE_UNSIGNED (rt));
2193 root->expr = build_ref_for_offset (UNKNOWN_LOCATION,
2194 root->base, root->offset,
2195 root->type, NULL, false);
2196 new_integer_type = true;
2199 new_integer_type = false;
2201 if (dump_file && (dump_flags & TDF_DETAILS))
2203 fprintf (dump_file, "Marking ");
2204 print_generic_expr (dump_file, root->base, 0);
2205 fprintf (dump_file, " offset: %u, size: %u ",
2206 (unsigned) root->offset, (unsigned) root->size);
2207 fprintf (dump_file, " to be replaced%s.\n",
2208 new_integer_type ? " with an integer": "");
2211 root->grp_to_be_replaced = 1;
2217 if (covered_to < limit)
2220 root->grp_total_scalarization = 0;
2224 && (!hole || root->grp_total_scalarization))
2226 root->grp_covered = 1;
2229 if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
2230 root->grp_unscalarized_data = 1; /* not covered and written to */
2236 /* Analyze all access trees linked by next_grp by the means of
2237 analyze_access_subtree. */
2239 analyze_access_trees (struct access *access)
2245 if (analyze_access_subtree (access, NULL, true))
2247 access = access->next_grp;
2253 /* Return true iff a potential new child of LACC at offset OFFSET and with size
2254 SIZE would conflict with an already existing one. If exactly such a child
2255 already exists in LACC, store a pointer to it in EXACT_MATCH. */
2258 child_would_conflict_in_lacc (struct access *lacc, HOST_WIDE_INT norm_offset,
2259 HOST_WIDE_INT size, struct access **exact_match)
2261 struct access *child;
2263 for (child = lacc->first_child; child; child = child->next_sibling)
2265 if (child->offset == norm_offset && child->size == size)
2267 *exact_match = child;
2271 if (child->offset < norm_offset + size
2272 && child->offset + child->size > norm_offset)
2279 /* Create a new child access of PARENT, with all properties just like MODEL
2280 except for its offset and with its grp_write false and grp_read true.
2281 Return the new access or NULL if it cannot be created. Note that this access
2282 is created long after all splicing and sorting, it's not located in any
2283 access vector and is automatically a representative of its group. */
2285 static struct access *
2286 create_artificial_child_access (struct access *parent, struct access *model,
2287 HOST_WIDE_INT new_offset)
2289 struct access *access;
2290 struct access **child;
2291 tree expr = parent->base;
2293 gcc_assert (!model->grp_unscalarizable_region);
2295 access = (struct access *) pool_alloc (access_pool);
2296 memset (access, 0, sizeof (struct access));
2297 if (!build_user_friendly_ref_for_offset (&expr, TREE_TYPE (expr), new_offset,
2300 access->grp_no_warning = true;
2301 expr = build_ref_for_model (EXPR_LOCATION (parent->base), parent->base,
2302 new_offset, model, NULL, false);
2305 access->base = parent->base;
2306 access->expr = expr;
2307 access->offset = new_offset;
2308 access->size = model->size;
2309 access->type = model->type;
2310 access->grp_write = true;
2311 access->grp_read = false;
2313 child = &parent->first_child;
2314 while (*child && (*child)->offset < new_offset)
2315 child = &(*child)->next_sibling;
2317 access->next_sibling = *child;
2324 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2325 true if any new subaccess was created. Additionally, if RACC is a scalar
2326 access but LACC is not, change the type of the latter, if possible. */
2329 propagate_subaccesses_across_link (struct access *lacc, struct access *racc)
2331 struct access *rchild;
2332 HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
2335 if (is_gimple_reg_type (lacc->type)
2336 || lacc->grp_unscalarizable_region
2337 || racc->grp_unscalarizable_region)
2340 if (is_gimple_reg_type (racc->type))
2342 if (!lacc->first_child && !racc->first_child)
2344 tree t = lacc->base;
2346 lacc->type = racc->type;
2347 if (build_user_friendly_ref_for_offset (&t, TREE_TYPE (t),
2348 lacc->offset, racc->type))
2352 lacc->expr = build_ref_for_model (EXPR_LOCATION (lacc->base),
2353 lacc->base, lacc->offset,
2355 lacc->grp_no_warning = true;
2361 for (rchild = racc->first_child; rchild; rchild = rchild->next_sibling)
2363 struct access *new_acc = NULL;
2364 HOST_WIDE_INT norm_offset = rchild->offset + norm_delta;
2366 if (rchild->grp_unscalarizable_region)
2369 if (child_would_conflict_in_lacc (lacc, norm_offset, rchild->size,
2374 rchild->grp_hint = 1;
2375 new_acc->grp_hint |= new_acc->grp_read;
2376 if (rchild->first_child)
2377 ret |= propagate_subaccesses_across_link (new_acc, rchild);
2382 rchild->grp_hint = 1;
2383 new_acc = create_artificial_child_access (lacc, rchild, norm_offset);
2387 if (racc->first_child)
2388 propagate_subaccesses_across_link (new_acc, rchild);
2395 /* Propagate all subaccesses across assignment links. */
2398 propagate_all_subaccesses (void)
2400 while (work_queue_head)
2402 struct access *racc = pop_access_from_work_queue ();
2403 struct assign_link *link;
2405 gcc_assert (racc->first_link);
2407 for (link = racc->first_link; link; link = link->next)
2409 struct access *lacc = link->lacc;
2411 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (lacc->base)))
2413 lacc = lacc->group_representative;
2414 if (propagate_subaccesses_across_link (lacc, racc)
2415 && lacc->first_link)
2416 add_access_to_work_queue (lacc);
2421 /* Go through all accesses collected throughout the (intraprocedural) analysis
2422 stage, exclude overlapping ones, identify representatives and build trees
2423 out of them, making decisions about scalarization on the way. Return true
2424 iff there are any to-be-scalarized variables after this stage. */
2427 analyze_all_variable_accesses (void)
2430 bitmap tmp = BITMAP_ALLOC (NULL);
2432 unsigned i, max_total_scalarization_size;
2434 max_total_scalarization_size = UNITS_PER_WORD * BITS_PER_UNIT
2435 * MOVE_RATIO (optimize_function_for_speed_p (cfun));
2437 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
2438 if (bitmap_bit_p (should_scalarize_away_bitmap, i)
2439 && !bitmap_bit_p (cannot_scalarize_away_bitmap, i))
2441 tree var = referenced_var (i);
2443 if (TREE_CODE (var) == VAR_DECL
2444 && type_consists_of_records_p (TREE_TYPE (var)))
2446 if ((unsigned) tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1)
2447 <= max_total_scalarization_size)
2449 completely_scalarize_var (var);
2450 if (dump_file && (dump_flags & TDF_DETAILS))
2452 fprintf (dump_file, "Will attempt to totally scalarize ");
2453 print_generic_expr (dump_file, var, 0);
2454 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2457 else if (dump_file && (dump_flags & TDF_DETAILS))
2459 fprintf (dump_file, "Too big to totally scalarize: ");
2460 print_generic_expr (dump_file, var, 0);
2461 fprintf (dump_file, " (UID: %u)\n", DECL_UID (var));
2466 bitmap_copy (tmp, candidate_bitmap);
2467 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2469 tree var = referenced_var (i);
2470 struct access *access;
2472 access = sort_and_splice_var_accesses (var);
2473 if (!access || !build_access_trees (access))
2474 disqualify_candidate (var,
2475 "No or inhibitingly overlapping accesses.");
2478 propagate_all_subaccesses ();
2480 bitmap_copy (tmp, candidate_bitmap);
2481 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2483 tree var = referenced_var (i);
2484 struct access *access = get_first_repr_for_decl (var);
2486 if (analyze_access_trees (access))
2489 if (dump_file && (dump_flags & TDF_DETAILS))
2491 fprintf (dump_file, "\nAccess trees for ");
2492 print_generic_expr (dump_file, var, 0);
2493 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2494 dump_access_tree (dump_file, access);
2495 fprintf (dump_file, "\n");
2499 disqualify_candidate (var, "No scalar replacements to be created.");
2506 statistics_counter_event (cfun, "Scalarized aggregates", res);
2513 /* Generate statements copying scalar replacements of accesses within a subtree
2514 into or out of AGG. ACCESS, all its children, siblings and their children
2515 are to be processed. AGG is an aggregate type expression (can be a
2516 declaration but does not have to be, it can for example also be a mem_ref or
2517 a series of handled components). TOP_OFFSET is the offset of the processed
2518 subtree which has to be subtracted from offsets of individual accesses to
2519 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2520 replacements in the interval <start_offset, start_offset + chunk_size>,
2521 otherwise copy all. GSI is a statement iterator used to place the new
2522 statements. WRITE should be true when the statements should write from AGG
2523 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2524 statements will be added after the current statement in GSI, they will be
2525 added before the statement otherwise. */
2528 generate_subtree_copies (struct access *access, tree agg,
2529 HOST_WIDE_INT top_offset,
2530 HOST_WIDE_INT start_offset, HOST_WIDE_INT chunk_size,
2531 gimple_stmt_iterator *gsi, bool write,
2532 bool insert_after, location_t loc)
2536 if (chunk_size && access->offset >= start_offset + chunk_size)
2539 if (access->grp_to_be_replaced
2541 || access->offset + access->size > start_offset))
2543 tree expr, repl = get_access_replacement (access);
2546 expr = build_ref_for_model (loc, agg, access->offset - top_offset,
2547 access, gsi, insert_after);
2551 if (access->grp_partial_lhs)
2552 expr = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE,
2554 insert_after ? GSI_NEW_STMT
2556 stmt = gimple_build_assign (repl, expr);
2560 TREE_NO_WARNING (repl) = 1;
2561 if (access->grp_partial_lhs)
2562 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2564 insert_after ? GSI_NEW_STMT
2566 stmt = gimple_build_assign (expr, repl);
2568 gimple_set_location (stmt, loc);
2571 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2573 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2575 sra_stats.subtree_copies++;
2578 if (access->first_child)
2579 generate_subtree_copies (access->first_child, agg, top_offset,
2580 start_offset, chunk_size, gsi,
2581 write, insert_after, loc);
2583 access = access->next_sibling;
2588 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2589 the root of the subtree to be processed. GSI is the statement iterator used
2590 for inserting statements which are added after the current statement if
2591 INSERT_AFTER is true or before it otherwise. */
2594 init_subtree_with_zero (struct access *access, gimple_stmt_iterator *gsi,
2595 bool insert_after, location_t loc)
2598 struct access *child;
2600 if (access->grp_to_be_replaced)
2604 stmt = gimple_build_assign (get_access_replacement (access),
2605 build_zero_cst (access->type));
2607 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2609 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2611 gimple_set_location (stmt, loc);
2614 for (child = access->first_child; child; child = child->next_sibling)
2615 init_subtree_with_zero (child, gsi, insert_after, loc);
2618 /* Search for an access representative for the given expression EXPR and
2619 return it or NULL if it cannot be found. */
2621 static struct access *
2622 get_access_for_expr (tree expr)
2624 HOST_WIDE_INT offset, size, max_size;
2627 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2628 a different size than the size of its argument and we need the latter
2630 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
2631 expr = TREE_OPERAND (expr, 0);
2633 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
2634 if (max_size == -1 || !DECL_P (base))
2637 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
2640 return get_var_base_offset_size_access (base, offset, max_size);
2643 /* Replace the expression EXPR with a scalar replacement if there is one and
2644 generate other statements to do type conversion or subtree copying if
2645 necessary. GSI is used to place newly created statements, WRITE is true if
2646 the expression is being written to (it is on a LHS of a statement or output
2647 in an assembly statement). */
2650 sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write)
2653 struct access *access;
2656 if (TREE_CODE (*expr) == BIT_FIELD_REF)
2659 expr = &TREE_OPERAND (*expr, 0);
2664 if (TREE_CODE (*expr) == REALPART_EXPR || TREE_CODE (*expr) == IMAGPART_EXPR)
2665 expr = &TREE_OPERAND (*expr, 0);
2666 access = get_access_for_expr (*expr);
2669 type = TREE_TYPE (*expr);
2671 loc = gimple_location (gsi_stmt (*gsi));
2672 if (access->grp_to_be_replaced)
2674 tree repl = get_access_replacement (access);
2675 /* If we replace a non-register typed access simply use the original
2676 access expression to extract the scalar component afterwards.
2677 This happens if scalarizing a function return value or parameter
2678 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2679 gcc.c-torture/compile/20011217-1.c.
2681 We also want to use this when accessing a complex or vector which can
2682 be accessed as a different type too, potentially creating a need for
2683 type conversion (see PR42196) and when scalarized unions are involved
2684 in assembler statements (see PR42398). */
2685 if (!useless_type_conversion_p (type, access->type))
2689 ref = build_ref_for_model (loc, access->base, access->offset, access,
2696 if (access->grp_partial_lhs)
2697 ref = force_gimple_operand_gsi (gsi, ref, true, NULL_TREE,
2698 false, GSI_NEW_STMT);
2699 stmt = gimple_build_assign (repl, ref);
2700 gimple_set_location (stmt, loc);
2701 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2707 if (access->grp_partial_lhs)
2708 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2709 true, GSI_SAME_STMT);
2710 stmt = gimple_build_assign (ref, repl);
2711 gimple_set_location (stmt, loc);
2712 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2720 if (access->first_child)
2722 HOST_WIDE_INT start_offset, chunk_size;
2724 && host_integerp (TREE_OPERAND (bfr, 1), 1)
2725 && host_integerp (TREE_OPERAND (bfr, 2), 1))
2727 chunk_size = tree_low_cst (TREE_OPERAND (bfr, 1), 1);
2728 start_offset = access->offset
2729 + tree_low_cst (TREE_OPERAND (bfr, 2), 1);
2732 start_offset = chunk_size = 0;
2734 generate_subtree_copies (access->first_child, access->base, 0,
2735 start_offset, chunk_size, gsi, write, write,
2741 /* Where scalar replacements of the RHS have been written to when a replacement
2742 of a LHS of an assigments cannot be direclty loaded from a replacement of
2744 enum unscalarized_data_handling { SRA_UDH_NONE, /* Nothing done so far. */
2745 SRA_UDH_RIGHT, /* Data flushed to the RHS. */
2746 SRA_UDH_LEFT }; /* Data flushed to the LHS. */
2748 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2749 base aggregate if there are unscalarized data or directly to LHS of the
2750 statement that is pointed to by GSI otherwise. */
2752 static enum unscalarized_data_handling
2753 handle_unscalarized_data_in_subtree (struct access *top_racc,
2754 gimple_stmt_iterator *gsi)
2756 if (top_racc->grp_unscalarized_data)
2758 generate_subtree_copies (top_racc->first_child, top_racc->base, 0, 0, 0,
2760 gimple_location (gsi_stmt (*gsi)));
2761 return SRA_UDH_RIGHT;
2765 tree lhs = gimple_assign_lhs (gsi_stmt (*gsi));
2766 generate_subtree_copies (top_racc->first_child, lhs, top_racc->offset,
2767 0, 0, gsi, false, false,
2768 gimple_location (gsi_stmt (*gsi)));
2769 return SRA_UDH_LEFT;
2774 /* Try to generate statements to load all sub-replacements in an access subtree
2775 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2776 If that is not possible, refresh the TOP_RACC base aggregate and load the
2777 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2778 copied. NEW_GSI is stmt iterator used for statement insertions after the
2779 original assignment, OLD_GSI is used to insert statements before the
2780 assignment. *REFRESHED keeps the information whether we have needed to
2781 refresh replacements of the LHS and from which side of the assignments this
2785 load_assign_lhs_subreplacements (struct access *lacc, struct access *top_racc,
2786 HOST_WIDE_INT left_offset,
2787 gimple_stmt_iterator *old_gsi,
2788 gimple_stmt_iterator *new_gsi,
2789 enum unscalarized_data_handling *refreshed)
2791 location_t loc = gimple_location (gsi_stmt (*old_gsi));
2792 for (lacc = lacc->first_child; lacc; lacc = lacc->next_sibling)
2794 if (lacc->grp_to_be_replaced)
2796 struct access *racc;
2797 HOST_WIDE_INT offset = lacc->offset - left_offset + top_racc->offset;
2801 racc = find_access_in_subtree (top_racc, offset, lacc->size);
2802 if (racc && racc->grp_to_be_replaced)
2804 rhs = get_access_replacement (racc);
2805 if (!useless_type_conversion_p (lacc->type, racc->type))
2806 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, lacc->type, rhs);
2808 if (racc->grp_partial_lhs && lacc->grp_partial_lhs)
2809 rhs = force_gimple_operand_gsi (old_gsi, rhs, true, NULL_TREE,
2810 true, GSI_SAME_STMT);
2814 /* No suitable access on the right hand side, need to load from
2815 the aggregate. See if we have to update it first... */
2816 if (*refreshed == SRA_UDH_NONE)
2817 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2820 if (*refreshed == SRA_UDH_LEFT)
2821 rhs = build_ref_for_model (loc, lacc->base, lacc->offset, lacc,
2824 rhs = build_ref_for_model (loc, top_racc->base, offset, lacc,
2826 if (lacc->grp_partial_lhs)
2827 rhs = force_gimple_operand_gsi (new_gsi, rhs, true, NULL_TREE,
2828 false, GSI_NEW_STMT);
2831 stmt = gimple_build_assign (get_access_replacement (lacc), rhs);
2832 gsi_insert_after (new_gsi, stmt, GSI_NEW_STMT);
2833 gimple_set_location (stmt, loc);
2835 sra_stats.subreplacements++;
2837 else if (*refreshed == SRA_UDH_NONE
2838 && lacc->grp_read && !lacc->grp_covered)
2839 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2842 if (lacc->first_child)
2843 load_assign_lhs_subreplacements (lacc, top_racc, left_offset,
2844 old_gsi, new_gsi, refreshed);
2848 /* Result code for SRA assignment modification. */
2849 enum assignment_mod_result { SRA_AM_NONE, /* nothing done for the stmt */
2850 SRA_AM_MODIFIED, /* stmt changed but not
2852 SRA_AM_REMOVED }; /* stmt eliminated */
2854 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2855 to the assignment and GSI is the statement iterator pointing at it. Returns
2856 the same values as sra_modify_assign. */
2858 static enum assignment_mod_result
2859 sra_modify_constructor_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2861 tree lhs = gimple_assign_lhs (*stmt);
2865 acc = get_access_for_expr (lhs);
2869 if (gimple_clobber_p (*stmt))
2871 /* Remove clobbers of fully scalarized variables, otherwise
2873 if (acc->grp_covered)
2875 unlink_stmt_vdef (*stmt);
2876 gsi_remove (gsi, true);
2877 return SRA_AM_REMOVED;
2883 loc = gimple_location (*stmt);
2884 if (VEC_length (constructor_elt,
2885 CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt))) > 0)
2887 /* I have never seen this code path trigger but if it can happen the
2888 following should handle it gracefully. */
2889 if (access_has_children_p (acc))
2890 generate_subtree_copies (acc->first_child, acc->base, 0, 0, 0, gsi,
2892 return SRA_AM_MODIFIED;
2895 if (acc->grp_covered)
2897 init_subtree_with_zero (acc, gsi, false, loc);
2898 unlink_stmt_vdef (*stmt);
2899 gsi_remove (gsi, true);
2900 return SRA_AM_REMOVED;
2904 init_subtree_with_zero (acc, gsi, true, loc);
2905 return SRA_AM_MODIFIED;
2909 /* Create and return a new suitable default definition SSA_NAME for RACC which
2910 is an access describing an uninitialized part of an aggregate that is being
2914 get_repl_default_def_ssa_name (struct access *racc)
2918 decl = get_unrenamed_access_replacement (racc);
2920 repl = gimple_default_def (cfun, decl);
2923 repl = make_ssa_name (decl, gimple_build_nop ());
2924 set_default_def (decl, repl);
2930 /* Return true if REF has a COMPONENT_REF with a bit-field field declaration
2934 contains_bitfld_comp_ref_p (const_tree ref)
2936 while (handled_component_p (ref))
2938 if (TREE_CODE (ref) == COMPONENT_REF
2939 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1)))
2941 ref = TREE_OPERAND (ref, 0);
2947 /* Return true if REF has an VIEW_CONVERT_EXPR or a COMPONENT_REF with a
2948 bit-field field declaration somewhere in it. */
2951 contains_vce_or_bfcref_p (const_tree ref)
2953 while (handled_component_p (ref))
2955 if (TREE_CODE (ref) == VIEW_CONVERT_EXPR
2956 || (TREE_CODE (ref) == COMPONENT_REF
2957 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))))
2959 ref = TREE_OPERAND (ref, 0);
2965 /* Examine both sides of the assignment statement pointed to by STMT, replace
2966 them with a scalare replacement if there is one and generate copying of
2967 replacements if scalarized aggregates have been used in the assignment. GSI
2968 is used to hold generated statements for type conversions and subtree
2971 static enum assignment_mod_result
2972 sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2974 struct access *lacc, *racc;
2976 bool modify_this_stmt = false;
2977 bool force_gimple_rhs = false;
2979 gimple_stmt_iterator orig_gsi = *gsi;
2981 if (!gimple_assign_single_p (*stmt))
2983 lhs = gimple_assign_lhs (*stmt);
2984 rhs = gimple_assign_rhs1 (*stmt);
2986 if (TREE_CODE (rhs) == CONSTRUCTOR)
2987 return sra_modify_constructor_assign (stmt, gsi);
2989 if (TREE_CODE (rhs) == REALPART_EXPR || TREE_CODE (lhs) == REALPART_EXPR
2990 || TREE_CODE (rhs) == IMAGPART_EXPR || TREE_CODE (lhs) == IMAGPART_EXPR
2991 || TREE_CODE (rhs) == BIT_FIELD_REF || TREE_CODE (lhs) == BIT_FIELD_REF)
2993 modify_this_stmt = sra_modify_expr (gimple_assign_rhs1_ptr (*stmt),
2995 modify_this_stmt |= sra_modify_expr (gimple_assign_lhs_ptr (*stmt),
2997 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3000 lacc = get_access_for_expr (lhs);
3001 racc = get_access_for_expr (rhs);
3005 loc = gimple_location (*stmt);
3006 if (lacc && lacc->grp_to_be_replaced)
3008 lhs = get_access_replacement (lacc);
3009 gimple_assign_set_lhs (*stmt, lhs);
3010 modify_this_stmt = true;
3011 if (lacc->grp_partial_lhs)
3012 force_gimple_rhs = true;
3016 if (racc && racc->grp_to_be_replaced)
3018 rhs = get_access_replacement (racc);
3019 modify_this_stmt = true;
3020 if (racc->grp_partial_lhs)
3021 force_gimple_rhs = true;
3025 && !racc->grp_unscalarized_data
3026 && TREE_CODE (lhs) == SSA_NAME
3027 && !access_has_replacements_p (racc))
3029 rhs = get_repl_default_def_ssa_name (racc);
3030 modify_this_stmt = true;
3034 if (modify_this_stmt)
3036 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
3038 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
3039 ??? This should move to fold_stmt which we simply should
3040 call after building a VIEW_CONVERT_EXPR here. */
3041 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
3042 && !contains_bitfld_comp_ref_p (lhs)
3043 && !access_has_children_p (lacc))
3045 lhs = build_ref_for_model (loc, lhs, 0, racc, gsi, false);
3046 gimple_assign_set_lhs (*stmt, lhs);
3048 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs))
3049 && !contains_vce_or_bfcref_p (rhs)
3050 && !access_has_children_p (racc))
3051 rhs = build_ref_for_model (loc, rhs, 0, lacc, gsi, false);
3053 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
3055 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, TREE_TYPE (lhs),
3057 if (is_gimple_reg_type (TREE_TYPE (lhs))
3058 && TREE_CODE (lhs) != SSA_NAME)
3059 force_gimple_rhs = true;
3064 /* From this point on, the function deals with assignments in between
3065 aggregates when at least one has scalar reductions of some of its
3066 components. There are three possible scenarios: Both the LHS and RHS have
3067 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
3069 In the first case, we would like to load the LHS components from RHS
3070 components whenever possible. If that is not possible, we would like to
3071 read it directly from the RHS (after updating it by storing in it its own
3072 components). If there are some necessary unscalarized data in the LHS,
3073 those will be loaded by the original assignment too. If neither of these
3074 cases happen, the original statement can be removed. Most of this is done
3075 by load_assign_lhs_subreplacements.
3077 In the second case, we would like to store all RHS scalarized components
3078 directly into LHS and if they cover the aggregate completely, remove the
3079 statement too. In the third case, we want the LHS components to be loaded
3080 directly from the RHS (DSE will remove the original statement if it
3083 This is a bit complex but manageable when types match and when unions do
3084 not cause confusion in a way that we cannot really load a component of LHS
3085 from the RHS or vice versa (the access representing this level can have
3086 subaccesses that are accessible only through a different union field at a
3087 higher level - different from the one used in the examined expression).
3090 Therefore, I specially handle a fourth case, happening when there is a
3091 specific type cast or it is impossible to locate a scalarized subaccess on
3092 the other side of the expression. If that happens, I simply "refresh" the
3093 RHS by storing in it is scalarized components leave the original statement
3094 there to do the copying and then load the scalar replacements of the LHS.
3095 This is what the first branch does. */
3097 if (modify_this_stmt
3098 || gimple_has_volatile_ops (*stmt)
3099 || contains_vce_or_bfcref_p (rhs)
3100 || contains_vce_or_bfcref_p (lhs))
3102 if (access_has_children_p (racc))
3103 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
3104 gsi, false, false, loc);
3105 if (access_has_children_p (lacc))
3106 generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
3107 gsi, true, true, loc);
3108 sra_stats.separate_lhs_rhs_handling++;
3110 /* This gimplification must be done after generate_subtree_copies,
3111 lest we insert the subtree copies in the middle of the gimplified
3113 if (force_gimple_rhs)
3114 rhs = force_gimple_operand_gsi (&orig_gsi, rhs, true, NULL_TREE,
3115 true, GSI_SAME_STMT);
3116 if (gimple_assign_rhs1 (*stmt) != rhs)
3118 modify_this_stmt = true;
3119 gimple_assign_set_rhs_from_tree (&orig_gsi, rhs);
3120 gcc_assert (*stmt == gsi_stmt (orig_gsi));
3123 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3127 if (access_has_children_p (lacc)
3128 && access_has_children_p (racc)
3129 /* When an access represents an unscalarizable region, it usually
3130 represents accesses with variable offset and thus must not be used
3131 to generate new memory accesses. */
3132 && !lacc->grp_unscalarizable_region
3133 && !racc->grp_unscalarizable_region)
3135 gimple_stmt_iterator orig_gsi = *gsi;
3136 enum unscalarized_data_handling refreshed;
3138 if (lacc->grp_read && !lacc->grp_covered)
3139 refreshed = handle_unscalarized_data_in_subtree (racc, gsi);
3141 refreshed = SRA_UDH_NONE;
3143 load_assign_lhs_subreplacements (lacc, racc, lacc->offset,
3144 &orig_gsi, gsi, &refreshed);
3145 if (refreshed != SRA_UDH_RIGHT)
3148 unlink_stmt_vdef (*stmt);
3149 gsi_remove (&orig_gsi, true);
3150 sra_stats.deleted++;
3151 return SRA_AM_REMOVED;
3156 if (access_has_children_p (racc)
3157 && !racc->grp_unscalarized_data)
3161 fprintf (dump_file, "Removing load: ");
3162 print_gimple_stmt (dump_file, *stmt, 0, 0);
3164 generate_subtree_copies (racc->first_child, lhs,
3165 racc->offset, 0, 0, gsi,
3167 gcc_assert (*stmt == gsi_stmt (*gsi));
3168 unlink_stmt_vdef (*stmt);
3169 gsi_remove (gsi, true);
3170 sra_stats.deleted++;
3171 return SRA_AM_REMOVED;
3173 /* Restore the aggregate RHS from its components so the
3174 prevailing aggregate copy does the right thing. */
3175 if (access_has_children_p (racc))
3176 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
3177 gsi, false, false, loc);
3178 /* Re-load the components of the aggregate copy destination.
3179 But use the RHS aggregate to load from to expose more
3180 optimization opportunities. */
3181 if (access_has_children_p (lacc))
3182 generate_subtree_copies (lacc->first_child, rhs, lacc->offset,
3183 0, 0, gsi, true, true, loc);
3190 /* Traverse the function body and all modifications as decided in
3191 analyze_all_variable_accesses. Return true iff the CFG has been
3195 sra_modify_function_body (void)
3197 bool cfg_changed = false;
3202 gimple_stmt_iterator gsi = gsi_start_bb (bb);
3203 while (!gsi_end_p (gsi))
3205 gimple stmt = gsi_stmt (gsi);
3206 enum assignment_mod_result assign_result;
3207 bool modified = false, deleted = false;
3211 switch (gimple_code (stmt))
3214 t = gimple_return_retval_ptr (stmt);
3215 if (*t != NULL_TREE)
3216 modified |= sra_modify_expr (t, &gsi, false);
3220 assign_result = sra_modify_assign (&stmt, &gsi);
3221 modified |= assign_result == SRA_AM_MODIFIED;
3222 deleted = assign_result == SRA_AM_REMOVED;
3226 /* Operands must be processed before the lhs. */
3227 for (i = 0; i < gimple_call_num_args (stmt); i++)
3229 t = gimple_call_arg_ptr (stmt, i);
3230 modified |= sra_modify_expr (t, &gsi, false);
3233 if (gimple_call_lhs (stmt))
3235 t = gimple_call_lhs_ptr (stmt);
3236 modified |= sra_modify_expr (t, &gsi, true);
3241 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
3243 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
3244 modified |= sra_modify_expr (t, &gsi, false);
3246 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
3248 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
3249 modified |= sra_modify_expr (t, &gsi, true);
3260 if (maybe_clean_eh_stmt (stmt)
3261 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
3272 /* Generate statements initializing scalar replacements of parts of function
3276 initialize_parameter_reductions (void)
3278 gimple_stmt_iterator gsi;
3279 gimple_seq seq = NULL;
3282 for (parm = DECL_ARGUMENTS (current_function_decl);
3284 parm = DECL_CHAIN (parm))
3286 VEC (access_p, heap) *access_vec;
3287 struct access *access;
3289 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3291 access_vec = get_base_access_vector (parm);
3297 seq = gimple_seq_alloc ();
3298 gsi = gsi_start (seq);
3301 for (access = VEC_index (access_p, access_vec, 0);
3303 access = access->next_grp)
3304 generate_subtree_copies (access, parm, 0, 0, 0, &gsi, true, true,
3305 EXPR_LOCATION (parm));
3309 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR), seq);
3312 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
3313 it reveals there are components of some aggregates to be scalarized, it runs
3314 the required transformations. */
3316 perform_intra_sra (void)
3321 if (!find_var_candidates ())
3324 if (!scan_function ())
3327 if (!analyze_all_variable_accesses ())
3330 if (sra_modify_function_body ())
3331 ret = TODO_update_ssa | TODO_cleanup_cfg;
3333 ret = TODO_update_ssa;
3334 initialize_parameter_reductions ();
3336 statistics_counter_event (cfun, "Scalar replacements created",
3337 sra_stats.replacements);
3338 statistics_counter_event (cfun, "Modified expressions", sra_stats.exprs);
3339 statistics_counter_event (cfun, "Subtree copy stmts",
3340 sra_stats.subtree_copies);
3341 statistics_counter_event (cfun, "Subreplacement stmts",
3342 sra_stats.subreplacements);
3343 statistics_counter_event (cfun, "Deleted stmts", sra_stats.deleted);
3344 statistics_counter_event (cfun, "Separate LHS and RHS handling",
3345 sra_stats.separate_lhs_rhs_handling);
3348 sra_deinitialize ();
3352 /* Perform early intraprocedural SRA. */
3354 early_intra_sra (void)
3356 sra_mode = SRA_MODE_EARLY_INTRA;
3357 return perform_intra_sra ();
3360 /* Perform "late" intraprocedural SRA. */
3362 late_intra_sra (void)
3364 sra_mode = SRA_MODE_INTRA;
3365 return perform_intra_sra ();
3370 gate_intra_sra (void)
3372 return flag_tree_sra != 0 && dbg_cnt (tree_sra);
3376 struct gimple_opt_pass pass_sra_early =
3381 gate_intra_sra, /* gate */
3382 early_intra_sra, /* execute */
3385 0, /* static_pass_number */
3386 TV_TREE_SRA, /* tv_id */
3387 PROP_cfg | PROP_ssa, /* properties_required */
3388 0, /* properties_provided */
3389 0, /* properties_destroyed */
3390 0, /* todo_flags_start */
3393 | TODO_verify_ssa /* todo_flags_finish */
3397 struct gimple_opt_pass pass_sra =
3402 gate_intra_sra, /* gate */
3403 late_intra_sra, /* execute */
3406 0, /* static_pass_number */
3407 TV_TREE_SRA, /* tv_id */
3408 PROP_cfg | PROP_ssa, /* properties_required */
3409 0, /* properties_provided */
3410 0, /* properties_destroyed */
3411 TODO_update_address_taken, /* todo_flags_start */
3414 | TODO_verify_ssa /* todo_flags_finish */
3419 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3423 is_unused_scalar_param (tree parm)
3426 return (is_gimple_reg (parm)
3427 && (!(name = gimple_default_def (cfun, parm))
3428 || has_zero_uses (name)));
3431 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3432 examine whether there are any direct or otherwise infeasible ones. If so,
3433 return true, otherwise return false. PARM must be a gimple register with a
3434 non-NULL default definition. */
3437 ptr_parm_has_direct_uses (tree parm)
3439 imm_use_iterator ui;
3441 tree name = gimple_default_def (cfun, parm);
3444 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
3447 use_operand_p use_p;
3449 if (is_gimple_debug (stmt))
3452 /* Valid uses include dereferences on the lhs and the rhs. */
3453 if (gimple_has_lhs (stmt))
3455 tree lhs = gimple_get_lhs (stmt);
3456 while (handled_component_p (lhs))
3457 lhs = TREE_OPERAND (lhs, 0);
3458 if (TREE_CODE (lhs) == MEM_REF
3459 && TREE_OPERAND (lhs, 0) == name
3460 && integer_zerop (TREE_OPERAND (lhs, 1))
3461 && types_compatible_p (TREE_TYPE (lhs),
3462 TREE_TYPE (TREE_TYPE (name)))
3463 && !TREE_THIS_VOLATILE (lhs))
3466 if (gimple_assign_single_p (stmt))
3468 tree rhs = gimple_assign_rhs1 (stmt);
3469 while (handled_component_p (rhs))
3470 rhs = TREE_OPERAND (rhs, 0);
3471 if (TREE_CODE (rhs) == MEM_REF
3472 && TREE_OPERAND (rhs, 0) == name
3473 && integer_zerop (TREE_OPERAND (rhs, 1))
3474 && types_compatible_p (TREE_TYPE (rhs),
3475 TREE_TYPE (TREE_TYPE (name)))
3476 && !TREE_THIS_VOLATILE (rhs))
3479 else if (is_gimple_call (stmt))
3482 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3484 tree arg = gimple_call_arg (stmt, i);
3485 while (handled_component_p (arg))
3486 arg = TREE_OPERAND (arg, 0);
3487 if (TREE_CODE (arg) == MEM_REF
3488 && TREE_OPERAND (arg, 0) == name
3489 && integer_zerop (TREE_OPERAND (arg, 1))
3490 && types_compatible_p (TREE_TYPE (arg),
3491 TREE_TYPE (TREE_TYPE (name)))
3492 && !TREE_THIS_VOLATILE (arg))
3497 /* If the number of valid uses does not match the number of
3498 uses in this stmt there is an unhandled use. */
3499 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
3506 BREAK_FROM_IMM_USE_STMT (ui);
3512 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3513 them in candidate_bitmap. Note that these do not necessarily include
3514 parameter which are unused and thus can be removed. Return true iff any
3515 such candidate has been found. */
3518 find_param_candidates (void)
3525 for (parm = DECL_ARGUMENTS (current_function_decl);
3527 parm = DECL_CHAIN (parm))
3529 tree type = TREE_TYPE (parm);
3533 if (TREE_THIS_VOLATILE (parm)
3534 || TREE_ADDRESSABLE (parm)
3535 || (!is_gimple_reg_type (type) && is_va_list_type (type)))
3538 if (is_unused_scalar_param (parm))
3544 if (POINTER_TYPE_P (type))
3546 type = TREE_TYPE (type);
3548 if (TREE_CODE (type) == FUNCTION_TYPE
3549 || TYPE_VOLATILE (type)
3550 || (TREE_CODE (type) == ARRAY_TYPE
3551 && TYPE_NONALIASED_COMPONENT (type))
3552 || !is_gimple_reg (parm)
3553 || is_va_list_type (type)
3554 || ptr_parm_has_direct_uses (parm))
3557 else if (!AGGREGATE_TYPE_P (type))
3560 if (!COMPLETE_TYPE_P (type)
3561 || !host_integerp (TYPE_SIZE (type), 1)
3562 || tree_low_cst (TYPE_SIZE (type), 1) == 0
3563 || (AGGREGATE_TYPE_P (type)
3564 && type_internals_preclude_sra_p (type, &msg)))
3567 bitmap_set_bit (candidate_bitmap, DECL_UID (parm));
3569 if (dump_file && (dump_flags & TDF_DETAILS))
3571 fprintf (dump_file, "Candidate (%d): ", DECL_UID (parm));
3572 print_generic_expr (dump_file, parm, 0);
3573 fprintf (dump_file, "\n");
3577 func_param_count = count;
3581 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3585 mark_maybe_modified (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef ATTRIBUTE_UNUSED,
3588 struct access *repr = (struct access *) data;
3590 repr->grp_maybe_modified = 1;
3594 /* Analyze what representatives (in linked lists accessible from
3595 REPRESENTATIVES) can be modified by side effects of statements in the
3596 current function. */
3599 analyze_modified_params (VEC (access_p, heap) *representatives)
3603 for (i = 0; i < func_param_count; i++)
3605 struct access *repr;
3607 for (repr = VEC_index (access_p, representatives, i);
3609 repr = repr->next_grp)
3611 struct access *access;
3615 if (no_accesses_p (repr))
3617 if (!POINTER_TYPE_P (TREE_TYPE (repr->base))
3618 || repr->grp_maybe_modified)
3621 ao_ref_init (&ar, repr->expr);
3622 visited = BITMAP_ALLOC (NULL);
3623 for (access = repr; access; access = access->next_sibling)
3625 /* All accesses are read ones, otherwise grp_maybe_modified would
3626 be trivially set. */
3627 walk_aliased_vdefs (&ar, gimple_vuse (access->stmt),
3628 mark_maybe_modified, repr, &visited);
3629 if (repr->grp_maybe_modified)
3632 BITMAP_FREE (visited);
3637 /* Propagate distances in bb_dereferences in the opposite direction than the
3638 control flow edges, in each step storing the maximum of the current value
3639 and the minimum of all successors. These steps are repeated until the table
3640 stabilizes. Note that BBs which might terminate the functions (according to
3641 final_bbs bitmap) never updated in this way. */
3644 propagate_dereference_distances (void)
3646 VEC (basic_block, heap) *queue;
3649 queue = VEC_alloc (basic_block, heap, last_basic_block_for_function (cfun));
3650 VEC_quick_push (basic_block, queue, ENTRY_BLOCK_PTR);
3653 VEC_quick_push (basic_block, queue, bb);
3657 while (!VEC_empty (basic_block, queue))
3661 bool change = false;
3664 bb = VEC_pop (basic_block, queue);
3667 if (bitmap_bit_p (final_bbs, bb->index))
3670 for (i = 0; i < func_param_count; i++)
3672 int idx = bb->index * func_param_count + i;
3674 HOST_WIDE_INT inh = 0;
3676 FOR_EACH_EDGE (e, ei, bb->succs)
3678 int succ_idx = e->dest->index * func_param_count + i;
3680 if (e->src == EXIT_BLOCK_PTR)
3686 inh = bb_dereferences [succ_idx];
3688 else if (bb_dereferences [succ_idx] < inh)
3689 inh = bb_dereferences [succ_idx];
3692 if (!first && bb_dereferences[idx] < inh)
3694 bb_dereferences[idx] = inh;
3699 if (change && !bitmap_bit_p (final_bbs, bb->index))
3700 FOR_EACH_EDGE (e, ei, bb->preds)
3705 e->src->aux = e->src;
3706 VEC_quick_push (basic_block, queue, e->src);
3710 VEC_free (basic_block, heap, queue);
3713 /* Dump a dereferences TABLE with heading STR to file F. */
3716 dump_dereferences_table (FILE *f, const char *str, HOST_WIDE_INT *table)
3720 fprintf (dump_file, str);
3721 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
3723 fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index));
3724 if (bb != EXIT_BLOCK_PTR)
3727 for (i = 0; i < func_param_count; i++)
3729 int idx = bb->index * func_param_count + i;
3730 fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", table[idx]);
3735 fprintf (dump_file, "\n");
3738 /* Determine what (parts of) parameters passed by reference that are not
3739 assigned to are not certainly dereferenced in this function and thus the
3740 dereferencing cannot be safely moved to the caller without potentially
3741 introducing a segfault. Mark such REPRESENTATIVES as
3742 grp_not_necessarilly_dereferenced.
3744 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3745 part is calculated rather than simple booleans are calculated for each
3746 pointer parameter to handle cases when only a fraction of the whole
3747 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3750 The maximum dereference distances for each pointer parameter and BB are
3751 already stored in bb_dereference. This routine simply propagates these
3752 values upwards by propagate_dereference_distances and then compares the
3753 distances of individual parameters in the ENTRY BB to the equivalent
3754 distances of each representative of a (fraction of a) parameter. */
3757 analyze_caller_dereference_legality (VEC (access_p, heap) *representatives)
3761 if (dump_file && (dump_flags & TDF_DETAILS))
3762 dump_dereferences_table (dump_file,
3763 "Dereference table before propagation:\n",
3766 propagate_dereference_distances ();
3768 if (dump_file && (dump_flags & TDF_DETAILS))
3769 dump_dereferences_table (dump_file,
3770 "Dereference table after propagation:\n",
3773 for (i = 0; i < func_param_count; i++)
3775 struct access *repr = VEC_index (access_p, representatives, i);
3776 int idx = ENTRY_BLOCK_PTR->index * func_param_count + i;
3778 if (!repr || no_accesses_p (repr))
3783 if ((repr->offset + repr->size) > bb_dereferences[idx])
3784 repr->grp_not_necessarilly_dereferenced = 1;
3785 repr = repr->next_grp;
3791 /* Return the representative access for the parameter declaration PARM if it is
3792 a scalar passed by reference which is not written to and the pointer value
3793 is not used directly. Thus, if it is legal to dereference it in the caller
3794 and we can rule out modifications through aliases, such parameter should be
3795 turned into one passed by value. Return NULL otherwise. */
3797 static struct access *
3798 unmodified_by_ref_scalar_representative (tree parm)
3800 int i, access_count;
3801 struct access *repr;
3802 VEC (access_p, heap) *access_vec;
3804 access_vec = get_base_access_vector (parm);
3805 gcc_assert (access_vec);
3806 repr = VEC_index (access_p, access_vec, 0);
3809 repr->group_representative = repr;
3811 access_count = VEC_length (access_p, access_vec);
3812 for (i = 1; i < access_count; i++)
3814 struct access *access = VEC_index (access_p, access_vec, i);
3817 access->group_representative = repr;
3818 access->next_sibling = repr->next_sibling;
3819 repr->next_sibling = access;
3823 repr->grp_scalar_ptr = 1;
3827 /* Return true iff this access precludes IPA-SRA of the parameter it is
3831 access_precludes_ipa_sra_p (struct access *access)
3833 /* Avoid issues such as the second simple testcase in PR 42025. The problem
3834 is incompatible assign in a call statement (and possibly even in asm
3835 statements). This can be relaxed by using a new temporary but only for
3836 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
3837 intraprocedural SRA we deal with this by keeping the old aggregate around,
3838 something we cannot do in IPA-SRA.) */
3840 && (is_gimple_call (access->stmt)
3841 || gimple_code (access->stmt) == GIMPLE_ASM))
3844 if (STRICT_ALIGNMENT
3845 && tree_non_aligned_mem_p (access->expr, TYPE_ALIGN (access->type)))
3852 /* Sort collected accesses for parameter PARM, identify representatives for
3853 each accessed region and link them together. Return NULL if there are
3854 different but overlapping accesses, return the special ptr value meaning
3855 there are no accesses for this parameter if that is the case and return the
3856 first representative otherwise. Set *RO_GRP if there is a group of accesses
3857 with only read (i.e. no write) accesses. */
3859 static struct access *
3860 splice_param_accesses (tree parm, bool *ro_grp)
3862 int i, j, access_count, group_count;
3863 int agg_size, total_size = 0;
3864 struct access *access, *res, **prev_acc_ptr = &res;
3865 VEC (access_p, heap) *access_vec;
3867 access_vec = get_base_access_vector (parm);
3869 return &no_accesses_representant;
3870 access_count = VEC_length (access_p, access_vec);
3872 VEC_qsort (access_p, access_vec, compare_access_positions);
3877 while (i < access_count)
3881 access = VEC_index (access_p, access_vec, i);
3882 modification = access->write;
3883 if (access_precludes_ipa_sra_p (access))
3885 a1_alias_type = reference_alias_ptr_type (access->expr);
3887 /* Access is about to become group representative unless we find some
3888 nasty overlap which would preclude us from breaking this parameter
3892 while (j < access_count)
3894 struct access *ac2 = VEC_index (access_p, access_vec, j);
3895 if (ac2->offset != access->offset)
3897 /* All or nothing law for parameters. */
3898 if (access->offset + access->size > ac2->offset)
3903 else if (ac2->size != access->size)
3906 if (access_precludes_ipa_sra_p (ac2)
3907 || (ac2->type != access->type
3908 && (TREE_ADDRESSABLE (ac2->type)
3909 || TREE_ADDRESSABLE (access->type)))
3910 || (reference_alias_ptr_type (ac2->expr) != a1_alias_type))
3913 modification |= ac2->write;
3914 ac2->group_representative = access;
3915 ac2->next_sibling = access->next_sibling;
3916 access->next_sibling = ac2;
3921 access->grp_maybe_modified = modification;
3924 *prev_acc_ptr = access;
3925 prev_acc_ptr = &access->next_grp;
3926 total_size += access->size;
3930 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3931 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3933 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3934 if (total_size >= agg_size)
3937 gcc_assert (group_count > 0);
3941 /* Decide whether parameters with representative accesses given by REPR should
3942 be reduced into components. */
3945 decide_one_param_reduction (struct access *repr)
3947 int total_size, cur_parm_size, agg_size, new_param_count, parm_size_limit;
3952 cur_parm_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3953 gcc_assert (cur_parm_size > 0);
3955 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3958 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3963 agg_size = cur_parm_size;
3969 fprintf (dump_file, "Evaluating PARAM group sizes for ");
3970 print_generic_expr (dump_file, parm, 0);
3971 fprintf (dump_file, " (UID: %u): \n", DECL_UID (parm));
3972 for (acc = repr; acc; acc = acc->next_grp)
3973 dump_access (dump_file, acc, true);
3977 new_param_count = 0;
3979 for (; repr; repr = repr->next_grp)
3981 gcc_assert (parm == repr->base);
3983 /* Taking the address of a non-addressable field is verboten. */
3984 if (by_ref && repr->non_addressable)
3987 /* Do not decompose a non-BLKmode param in a way that would
3988 create BLKmode params. Especially for by-reference passing
3989 (thus, pointer-type param) this is hardly worthwhile. */
3990 if (DECL_MODE (parm) != BLKmode
3991 && TYPE_MODE (repr->type) == BLKmode)
3994 if (!by_ref || (!repr->grp_maybe_modified
3995 && !repr->grp_not_necessarilly_dereferenced))
3996 total_size += repr->size;
3998 total_size += cur_parm_size;
4003 gcc_assert (new_param_count > 0);
4005 if (optimize_function_for_size_p (cfun))
4006 parm_size_limit = cur_parm_size;
4008 parm_size_limit = (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR)
4011 if (total_size < agg_size
4012 && total_size <= parm_size_limit)
4015 fprintf (dump_file, " ....will be split into %i components\n",
4017 return new_param_count;
4023 /* The order of the following enums is important, we need to do extra work for
4024 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
4025 enum ipa_splicing_result { NO_GOOD_ACCESS, UNUSED_PARAMS, BY_VAL_ACCESSES,
4026 MODIF_BY_REF_ACCESSES, UNMODIF_BY_REF_ACCESSES };
4028 /* Identify representatives of all accesses to all candidate parameters for
4029 IPA-SRA. Return result based on what representatives have been found. */
4031 static enum ipa_splicing_result
4032 splice_all_param_accesses (VEC (access_p, heap) **representatives)
4034 enum ipa_splicing_result result = NO_GOOD_ACCESS;
4036 struct access *repr;
4038 *representatives = VEC_alloc (access_p, heap, func_param_count);
4040 for (parm = DECL_ARGUMENTS (current_function_decl);
4042 parm = DECL_CHAIN (parm))
4044 if (is_unused_scalar_param (parm))
4046 VEC_quick_push (access_p, *representatives,
4047 &no_accesses_representant);
4048 if (result == NO_GOOD_ACCESS)
4049 result = UNUSED_PARAMS;
4051 else if (POINTER_TYPE_P (TREE_TYPE (parm))
4052 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm)))
4053 && bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
4055 repr = unmodified_by_ref_scalar_representative (parm);
4056 VEC_quick_push (access_p, *representatives, repr);
4058 result = UNMODIF_BY_REF_ACCESSES;
4060 else if (bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
4062 bool ro_grp = false;
4063 repr = splice_param_accesses (parm, &ro_grp);
4064 VEC_quick_push (access_p, *representatives, repr);
4066 if (repr && !no_accesses_p (repr))
4068 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4071 result = UNMODIF_BY_REF_ACCESSES;
4072 else if (result < MODIF_BY_REF_ACCESSES)
4073 result = MODIF_BY_REF_ACCESSES;
4075 else if (result < BY_VAL_ACCESSES)
4076 result = BY_VAL_ACCESSES;
4078 else if (no_accesses_p (repr) && (result == NO_GOOD_ACCESS))
4079 result = UNUSED_PARAMS;
4082 VEC_quick_push (access_p, *representatives, NULL);
4085 if (result == NO_GOOD_ACCESS)
4087 VEC_free (access_p, heap, *representatives);
4088 *representatives = NULL;
4089 return NO_GOOD_ACCESS;
4095 /* Return the index of BASE in PARMS. Abort if it is not found. */
4098 get_param_index (tree base, VEC(tree, heap) *parms)
4102 len = VEC_length (tree, parms);
4103 for (i = 0; i < len; i++)
4104 if (VEC_index (tree, parms, i) == base)
4109 /* Convert the decisions made at the representative level into compact
4110 parameter adjustments. REPRESENTATIVES are pointers to first
4111 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
4112 final number of adjustments. */
4114 static ipa_parm_adjustment_vec
4115 turn_representatives_into_adjustments (VEC (access_p, heap) *representatives,
4116 int adjustments_count)
4118 VEC (tree, heap) *parms;
4119 ipa_parm_adjustment_vec adjustments;
4123 gcc_assert (adjustments_count > 0);
4124 parms = ipa_get_vector_of_formal_parms (current_function_decl);
4125 adjustments = VEC_alloc (ipa_parm_adjustment_t, heap, adjustments_count);
4126 parm = DECL_ARGUMENTS (current_function_decl);
4127 for (i = 0; i < func_param_count; i++, parm = DECL_CHAIN (parm))
4129 struct access *repr = VEC_index (access_p, representatives, i);
4131 if (!repr || no_accesses_p (repr))
4133 struct ipa_parm_adjustment *adj;
4135 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
4136 memset (adj, 0, sizeof (*adj));
4137 adj->base_index = get_param_index (parm, parms);
4140 adj->copy_param = 1;
4142 adj->remove_param = 1;
4146 struct ipa_parm_adjustment *adj;
4147 int index = get_param_index (parm, parms);
4149 for (; repr; repr = repr->next_grp)
4151 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
4152 memset (adj, 0, sizeof (*adj));
4153 gcc_assert (repr->base == parm);
4154 adj->base_index = index;
4155 adj->base = repr->base;
4156 adj->type = repr->type;
4157 adj->alias_ptr_type = reference_alias_ptr_type (repr->expr);
4158 adj->offset = repr->offset;
4159 adj->by_ref = (POINTER_TYPE_P (TREE_TYPE (repr->base))
4160 && (repr->grp_maybe_modified
4161 || repr->grp_not_necessarilly_dereferenced));
4166 VEC_free (tree, heap, parms);
4170 /* Analyze the collected accesses and produce a plan what to do with the
4171 parameters in the form of adjustments, NULL meaning nothing. */
4173 static ipa_parm_adjustment_vec
4174 analyze_all_param_acesses (void)
4176 enum ipa_splicing_result repr_state;
4177 bool proceed = false;
4178 int i, adjustments_count = 0;
4179 VEC (access_p, heap) *representatives;
4180 ipa_parm_adjustment_vec adjustments;
4182 repr_state = splice_all_param_accesses (&representatives);
4183 if (repr_state == NO_GOOD_ACCESS)
4186 /* If there are any parameters passed by reference which are not modified
4187 directly, we need to check whether they can be modified indirectly. */
4188 if (repr_state == UNMODIF_BY_REF_ACCESSES)
4190 analyze_caller_dereference_legality (representatives);
4191 analyze_modified_params (representatives);
4194 for (i = 0; i < func_param_count; i++)
4196 struct access *repr = VEC_index (access_p, representatives, i);
4198 if (repr && !no_accesses_p (repr))
4200 if (repr->grp_scalar_ptr)
4202 adjustments_count++;
4203 if (repr->grp_not_necessarilly_dereferenced
4204 || repr->grp_maybe_modified)
4205 VEC_replace (access_p, representatives, i, NULL);
4209 sra_stats.scalar_by_ref_to_by_val++;
4214 int new_components = decide_one_param_reduction (repr);
4216 if (new_components == 0)
4218 VEC_replace (access_p, representatives, i, NULL);
4219 adjustments_count++;
4223 adjustments_count += new_components;
4224 sra_stats.aggregate_params_reduced++;
4225 sra_stats.param_reductions_created += new_components;
4232 if (no_accesses_p (repr))
4235 sra_stats.deleted_unused_parameters++;
4237 adjustments_count++;
4241 if (!proceed && dump_file)
4242 fprintf (dump_file, "NOT proceeding to change params.\n");
4245 adjustments = turn_representatives_into_adjustments (representatives,
4250 VEC_free (access_p, heap, representatives);
4254 /* If a parameter replacement identified by ADJ does not yet exist in the form
4255 of declaration, create it and record it, otherwise return the previously
4259 get_replaced_param_substitute (struct ipa_parm_adjustment *adj)
4262 if (!adj->new_ssa_base)
4264 char *pretty_name = make_fancy_name (adj->base);
4266 repl = create_tmp_reg (TREE_TYPE (adj->base), "ISR");
4267 DECL_NAME (repl) = get_identifier (pretty_name);
4268 obstack_free (&name_obstack, pretty_name);
4270 add_referenced_var (repl);
4271 adj->new_ssa_base = repl;
4274 repl = adj->new_ssa_base;
4278 /* Find the first adjustment for a particular parameter BASE in a vector of
4279 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
4282 static struct ipa_parm_adjustment *
4283 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments, tree base)
4287 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4288 for (i = 0; i < len; i++)
4290 struct ipa_parm_adjustment *adj;
4292 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4293 if (!adj->copy_param && adj->base == base)
4300 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
4301 removed because its value is not used, replace the SSA_NAME with a one
4302 relating to a created VAR_DECL together all of its uses and return true.
4303 ADJUSTMENTS is a pointer to an adjustments vector. */
4306 replace_removed_params_ssa_names (gimple stmt,
4307 ipa_parm_adjustment_vec adjustments)
4309 struct ipa_parm_adjustment *adj;
4310 tree lhs, decl, repl, name;
4312 if (gimple_code (stmt) == GIMPLE_PHI)
4313 lhs = gimple_phi_result (stmt);
4314 else if (is_gimple_assign (stmt))
4315 lhs = gimple_assign_lhs (stmt);
4316 else if (is_gimple_call (stmt))
4317 lhs = gimple_call_lhs (stmt);
4321 if (TREE_CODE (lhs) != SSA_NAME)
4323 decl = SSA_NAME_VAR (lhs);
4324 if (TREE_CODE (decl) != PARM_DECL)
4327 adj = get_adjustment_for_base (adjustments, decl);
4331 repl = get_replaced_param_substitute (adj);
4332 name = make_ssa_name (repl, stmt);
4336 fprintf (dump_file, "replacing an SSA name of a removed param ");
4337 print_generic_expr (dump_file, lhs, 0);
4338 fprintf (dump_file, " with ");
4339 print_generic_expr (dump_file, name, 0);
4340 fprintf (dump_file, "\n");
4343 if (is_gimple_assign (stmt))
4344 gimple_assign_set_lhs (stmt, name);
4345 else if (is_gimple_call (stmt))
4346 gimple_call_set_lhs (stmt, name);
4348 gimple_phi_set_result (stmt, name);
4350 replace_uses_by (lhs, name);
4351 release_ssa_name (lhs);
4355 /* If the expression *EXPR should be replaced by a reduction of a parameter, do
4356 so. ADJUSTMENTS is a pointer to a vector of adjustments. CONVERT
4357 specifies whether the function should care about type incompatibility the
4358 current and new expressions. If it is false, the function will leave
4359 incompatibility issues to the caller. Return true iff the expression
4363 sra_ipa_modify_expr (tree *expr, bool convert,
4364 ipa_parm_adjustment_vec adjustments)
4367 struct ipa_parm_adjustment *adj, *cand = NULL;
4368 HOST_WIDE_INT offset, size, max_size;
4371 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4373 if (TREE_CODE (*expr) == BIT_FIELD_REF
4374 || TREE_CODE (*expr) == IMAGPART_EXPR
4375 || TREE_CODE (*expr) == REALPART_EXPR)
4377 expr = &TREE_OPERAND (*expr, 0);
4381 base = get_ref_base_and_extent (*expr, &offset, &size, &max_size);
4382 if (!base || size == -1 || max_size == -1)
4385 if (TREE_CODE (base) == MEM_REF)
4387 offset += mem_ref_offset (base).low * BITS_PER_UNIT;
4388 base = TREE_OPERAND (base, 0);
4391 base = get_ssa_base_param (base);
4392 if (!base || TREE_CODE (base) != PARM_DECL)
4395 for (i = 0; i < len; i++)
4397 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4399 if (adj->base == base &&
4400 (adj->offset == offset || adj->remove_param))
4406 if (!cand || cand->copy_param || cand->remove_param)
4410 src = build_simple_mem_ref (cand->reduction);
4412 src = cand->reduction;
4414 if (dump_file && (dump_flags & TDF_DETAILS))
4416 fprintf (dump_file, "About to replace expr ");
4417 print_generic_expr (dump_file, *expr, 0);
4418 fprintf (dump_file, " with ");
4419 print_generic_expr (dump_file, src, 0);
4420 fprintf (dump_file, "\n");
4423 if (convert && !useless_type_conversion_p (TREE_TYPE (*expr), cand->type))
4425 tree vce = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (*expr), src);
4433 /* If the statement pointed to by STMT_PTR contains any expressions that need
4434 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4435 potential type incompatibilities (GSI is used to accommodate conversion
4436 statements and must point to the statement). Return true iff the statement
4440 sra_ipa_modify_assign (gimple *stmt_ptr, gimple_stmt_iterator *gsi,
4441 ipa_parm_adjustment_vec adjustments)
4443 gimple stmt = *stmt_ptr;
4444 tree *lhs_p, *rhs_p;
4447 if (!gimple_assign_single_p (stmt))
4450 rhs_p = gimple_assign_rhs1_ptr (stmt);
4451 lhs_p = gimple_assign_lhs_ptr (stmt);
4453 any = sra_ipa_modify_expr (rhs_p, false, adjustments);
4454 any |= sra_ipa_modify_expr (lhs_p, false, adjustments);
4457 tree new_rhs = NULL_TREE;
4459 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p), TREE_TYPE (*rhs_p)))
4461 if (TREE_CODE (*rhs_p) == CONSTRUCTOR)
4463 /* V_C_Es of constructors can cause trouble (PR 42714). */
4464 if (is_gimple_reg_type (TREE_TYPE (*lhs_p)))
4465 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
4467 *rhs_p = build_constructor (TREE_TYPE (*lhs_p), 0);
4470 new_rhs = fold_build1_loc (gimple_location (stmt),
4471 VIEW_CONVERT_EXPR, TREE_TYPE (*lhs_p),
4474 else if (REFERENCE_CLASS_P (*rhs_p)
4475 && is_gimple_reg_type (TREE_TYPE (*lhs_p))
4476 && !is_gimple_reg (*lhs_p))
4477 /* This can happen when an assignment in between two single field
4478 structures is turned into an assignment in between two pointers to
4479 scalars (PR 42237). */
4484 tree tmp = force_gimple_operand_gsi (gsi, new_rhs, true, NULL_TREE,
4485 true, GSI_SAME_STMT);
4487 gimple_assign_set_rhs_from_tree (gsi, tmp);
4496 /* Traverse the function body and all modifications as described in
4497 ADJUSTMENTS. Return true iff the CFG has been changed. */
4500 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments)
4502 bool cfg_changed = false;
4507 gimple_stmt_iterator gsi;
4509 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4510 replace_removed_params_ssa_names (gsi_stmt (gsi), adjustments);
4512 gsi = gsi_start_bb (bb);
4513 while (!gsi_end_p (gsi))
4515 gimple stmt = gsi_stmt (gsi);
4516 bool modified = false;
4520 switch (gimple_code (stmt))
4523 t = gimple_return_retval_ptr (stmt);
4524 if (*t != NULL_TREE)
4525 modified |= sra_ipa_modify_expr (t, true, adjustments);
4529 modified |= sra_ipa_modify_assign (&stmt, &gsi, adjustments);
4530 modified |= replace_removed_params_ssa_names (stmt, adjustments);
4534 /* Operands must be processed before the lhs. */
4535 for (i = 0; i < gimple_call_num_args (stmt); i++)
4537 t = gimple_call_arg_ptr (stmt, i);
4538 modified |= sra_ipa_modify_expr (t, true, adjustments);
4541 if (gimple_call_lhs (stmt))
4543 t = gimple_call_lhs_ptr (stmt);
4544 modified |= sra_ipa_modify_expr (t, false, adjustments);
4545 modified |= replace_removed_params_ssa_names (stmt,
4551 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
4553 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
4554 modified |= sra_ipa_modify_expr (t, true, adjustments);
4556 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
4558 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
4559 modified |= sra_ipa_modify_expr (t, false, adjustments);
4570 if (maybe_clean_eh_stmt (stmt)
4571 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
4581 /* Call gimple_debug_bind_reset_value on all debug statements describing
4582 gimple register parameters that are being removed or replaced. */
4585 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments)
4588 gimple_stmt_iterator *gsip = NULL, gsi;
4590 if (MAY_HAVE_DEBUG_STMTS && single_succ_p (ENTRY_BLOCK_PTR))
4592 gsi = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR));
4595 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4596 for (i = 0; i < len; i++)
4598 struct ipa_parm_adjustment *adj;
4599 imm_use_iterator ui;
4600 gimple stmt, def_temp;
4601 tree name, vexpr, copy = NULL_TREE;
4602 use_operand_p use_p;
4604 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4605 if (adj->copy_param || !is_gimple_reg (adj->base))
4607 name = gimple_default_def (cfun, adj->base);
4610 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
4612 /* All other users must have been removed by
4613 ipa_sra_modify_function_body. */
4614 gcc_assert (is_gimple_debug (stmt));
4615 if (vexpr == NULL && gsip != NULL)
4617 gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
4618 vexpr = make_node (DEBUG_EXPR_DECL);
4619 def_temp = gimple_build_debug_source_bind (vexpr, adj->base,
4621 DECL_ARTIFICIAL (vexpr) = 1;
4622 TREE_TYPE (vexpr) = TREE_TYPE (name);
4623 DECL_MODE (vexpr) = DECL_MODE (adj->base);
4624 gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
4628 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
4629 SET_USE (use_p, vexpr);
4632 gimple_debug_bind_reset_value (stmt);
4635 /* Create a VAR_DECL for debug info purposes. */
4636 if (!DECL_IGNORED_P (adj->base))
4638 copy = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
4639 VAR_DECL, DECL_NAME (adj->base),
4640 TREE_TYPE (adj->base));
4641 if (DECL_PT_UID_SET_P (adj->base))
4642 SET_DECL_PT_UID (copy, DECL_PT_UID (adj->base));
4643 TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (adj->base);
4644 TREE_READONLY (copy) = TREE_READONLY (adj->base);
4645 TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (adj->base);
4646 DECL_GIMPLE_REG_P (copy) = DECL_GIMPLE_REG_P (adj->base);
4647 DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (adj->base);
4648 DECL_IGNORED_P (copy) = DECL_IGNORED_P (adj->base);
4649 DECL_ABSTRACT_ORIGIN (copy) = DECL_ORIGIN (adj->base);
4650 DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
4651 SET_DECL_RTL (copy, 0);
4652 TREE_USED (copy) = 1;
4653 DECL_CONTEXT (copy) = current_function_decl;
4654 add_referenced_var (copy);
4655 add_local_decl (cfun, copy);
4657 BLOCK_VARS (DECL_INITIAL (current_function_decl));
4658 BLOCK_VARS (DECL_INITIAL (current_function_decl)) = copy;
4660 if (gsip != NULL && copy && target_for_debug_bind (adj->base))
4662 gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
4664 def_temp = gimple_build_debug_bind (copy, vexpr, NULL);
4666 def_temp = gimple_build_debug_source_bind (copy, adj->base,
4668 gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
4673 /* Return false iff all callers have at least as many actual arguments as there
4674 are formal parameters in the current function. */
4677 not_all_callers_have_enough_arguments_p (struct cgraph_node *node,
4678 void *data ATTRIBUTE_UNUSED)
4680 struct cgraph_edge *cs;
4681 for (cs = node->callers; cs; cs = cs->next_caller)
4682 if (!callsite_has_enough_arguments_p (cs->call_stmt))
4688 /* Convert all callers of NODE. */
4691 convert_callers_for_node (struct cgraph_node *node,
4694 ipa_parm_adjustment_vec adjustments = (ipa_parm_adjustment_vec)data;
4695 bitmap recomputed_callers = BITMAP_ALLOC (NULL);
4696 struct cgraph_edge *cs;
4698 for (cs = node->callers; cs; cs = cs->next_caller)
4700 current_function_decl = cs->caller->decl;
4701 push_cfun (DECL_STRUCT_FUNCTION (cs->caller->decl));
4704 fprintf (dump_file, "Adjusting call (%i -> %i) %s -> %s\n",
4705 cs->caller->uid, cs->callee->uid,
4706 xstrdup (cgraph_node_name (cs->caller)),
4707 xstrdup (cgraph_node_name (cs->callee)));
4709 ipa_modify_call_arguments (cs, cs->call_stmt, adjustments);
4714 for (cs = node->callers; cs; cs = cs->next_caller)
4715 if (bitmap_set_bit (recomputed_callers, cs->caller->uid)
4716 && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (cs->caller->decl)))
4717 compute_inline_parameters (cs->caller, true);
4718 BITMAP_FREE (recomputed_callers);
4723 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4726 convert_callers (struct cgraph_node *node, tree old_decl,
4727 ipa_parm_adjustment_vec adjustments)
4729 tree old_cur_fndecl = current_function_decl;
4730 basic_block this_block;
4732 cgraph_for_node_and_aliases (node, convert_callers_for_node,
4733 adjustments, false);
4735 current_function_decl = old_cur_fndecl;
4737 if (!encountered_recursive_call)
4740 FOR_EACH_BB (this_block)
4742 gimple_stmt_iterator gsi;
4744 for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
4746 gimple stmt = gsi_stmt (gsi);
4748 if (gimple_code (stmt) != GIMPLE_CALL)
4750 call_fndecl = gimple_call_fndecl (stmt);
4751 if (call_fndecl == old_decl)
4754 fprintf (dump_file, "Adjusting recursive call");
4755 gimple_call_set_fndecl (stmt, node->decl);
4756 ipa_modify_call_arguments (NULL, stmt, adjustments);
4764 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4765 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4768 modify_function (struct cgraph_node *node, ipa_parm_adjustment_vec adjustments)
4770 struct cgraph_node *new_node;
4772 VEC (cgraph_edge_p, heap) * redirect_callers = collect_callers_of_node (node);
4774 rebuild_cgraph_edges ();
4775 free_dominance_info (CDI_DOMINATORS);
4777 current_function_decl = NULL_TREE;
4779 new_node = cgraph_function_versioning (node, redirect_callers, NULL, NULL,
4780 false, NULL, NULL, "isra");
4781 VEC_free (cgraph_edge_p, heap, redirect_callers);
4783 current_function_decl = new_node->decl;
4784 push_cfun (DECL_STRUCT_FUNCTION (new_node->decl));
4786 ipa_modify_formal_parameters (current_function_decl, adjustments, "ISRA");
4787 cfg_changed = ipa_sra_modify_function_body (adjustments);
4788 sra_ipa_reset_debug_stmts (adjustments);
4789 convert_callers (new_node, node->decl, adjustments);
4790 cgraph_make_node_local (new_node);
4794 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4795 attributes, return true otherwise. NODE is the cgraph node of the current
4799 ipa_sra_preliminary_function_checks (struct cgraph_node *node)
4801 if (!cgraph_node_can_be_local_p (node))
4804 fprintf (dump_file, "Function not local to this compilation unit.\n");
4808 if (!node->local.can_change_signature)
4811 fprintf (dump_file, "Function can not change signature.\n");
4815 if (!tree_versionable_function_p (node->decl))
4818 fprintf (dump_file, "Function is not versionable.\n");
4822 if (DECL_VIRTUAL_P (current_function_decl))
4825 fprintf (dump_file, "Function is a virtual method.\n");
4829 if ((DECL_COMDAT (node->decl) || DECL_EXTERNAL (node->decl))
4830 && inline_summary(node)->size >= MAX_INLINE_INSNS_AUTO)
4833 fprintf (dump_file, "Function too big to be made truly local.\n");
4841 "Function has no callers in this compilation unit.\n");
4848 fprintf (dump_file, "Function uses stdarg. \n");
4852 if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl)))
4858 /* Perform early interprocedural SRA. */
4861 ipa_early_sra (void)
4863 struct cgraph_node *node = cgraph_get_node (current_function_decl);
4864 ipa_parm_adjustment_vec adjustments;
4867 if (!ipa_sra_preliminary_function_checks (node))
4871 sra_mode = SRA_MODE_EARLY_IPA;
4873 if (!find_param_candidates ())
4876 fprintf (dump_file, "Function has no IPA-SRA candidates.\n");
4880 if (cgraph_for_node_and_aliases (node, not_all_callers_have_enough_arguments_p,
4884 fprintf (dump_file, "There are callers with insufficient number of "
4889 bb_dereferences = XCNEWVEC (HOST_WIDE_INT,
4891 * last_basic_block_for_function (cfun));
4892 final_bbs = BITMAP_ALLOC (NULL);
4895 if (encountered_apply_args)
4898 fprintf (dump_file, "Function calls __builtin_apply_args().\n");
4902 if (encountered_unchangable_recursive_call)
4905 fprintf (dump_file, "Function calls itself with insufficient "
4906 "number of arguments.\n");
4910 adjustments = analyze_all_param_acesses ();
4914 ipa_dump_param_adjustments (dump_file, adjustments, current_function_decl);
4916 if (modify_function (node, adjustments))
4917 ret = TODO_update_ssa | TODO_cleanup_cfg;
4919 ret = TODO_update_ssa;
4920 VEC_free (ipa_parm_adjustment_t, heap, adjustments);
4922 statistics_counter_event (cfun, "Unused parameters deleted",
4923 sra_stats.deleted_unused_parameters);
4924 statistics_counter_event (cfun, "Scalar parameters converted to by-value",
4925 sra_stats.scalar_by_ref_to_by_val);
4926 statistics_counter_event (cfun, "Aggregate parameters broken up",
4927 sra_stats.aggregate_params_reduced);
4928 statistics_counter_event (cfun, "Aggregate parameter components created",
4929 sra_stats.param_reductions_created);
4932 BITMAP_FREE (final_bbs);
4933 free (bb_dereferences);
4935 sra_deinitialize ();
4939 /* Return if early ipa sra shall be performed. */
4941 ipa_early_sra_gate (void)
4943 return flag_ipa_sra && dbg_cnt (eipa_sra);
4946 struct gimple_opt_pass pass_early_ipa_sra =
4950 "eipa_sra", /* name */
4951 ipa_early_sra_gate, /* gate */
4952 ipa_early_sra, /* execute */
4955 0, /* static_pass_number */
4956 TV_IPA_SRA, /* tv_id */
4957 0, /* properties_required */
4958 0, /* properties_provided */
4959 0, /* properties_destroyed */
4960 0, /* todo_flags_start */
4961 TODO_dump_cgraph /* todo_flags_finish */