1 /* Scalar Replacement of Aggregates (SRA) converts some structure
2 references into scalar references, exposing them to the scalar
4 Copyright (C) 2008-2013 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"
83 #include "tree-pass.h"
85 #include "statistics.h"
90 #include "tree-inline.h"
91 #include "gimple-pretty-print.h"
92 #include "ipa-inline.h"
94 /* Enumeration of all aggregate reductions we can do. */
95 enum sra_mode { SRA_MODE_EARLY_IPA, /* early call regularization */
96 SRA_MODE_EARLY_INTRA, /* early intraprocedural SRA */
97 SRA_MODE_INTRA }; /* late intraprocedural SRA */
99 /* Global variable describing which aggregate reduction we are performing at
101 static enum sra_mode sra_mode;
105 /* ACCESS represents each access to an aggregate variable (as a whole or a
106 part). It can also represent a group of accesses that refer to exactly the
107 same fragment of an aggregate (i.e. those that have exactly the same offset
108 and size). Such representatives for a single aggregate, once determined,
109 are linked in a linked list and have the group fields set.
111 Moreover, when doing intraprocedural SRA, a tree is built from those
112 representatives (by the means of first_child and next_sibling pointers), in
113 which all items in a subtree are "within" the root, i.e. their offset is
114 greater or equal to offset of the root and offset+size is smaller or equal
115 to offset+size of the root. Children of an access are sorted by offset.
117 Note that accesses to parts of vector and complex number types always
118 represented by an access to the whole complex number or a vector. It is a
119 duty of the modifying functions to replace them appropriately. */
123 /* Values returned by `get_ref_base_and_extent' for each component reference
124 If EXPR isn't a component reference just set `BASE = EXPR', `OFFSET = 0',
125 `SIZE = TREE_SIZE (TREE_TYPE (expr))'. */
126 HOST_WIDE_INT offset;
130 /* Expression. It is context dependent so do not use it to create new
131 expressions to access the original aggregate. See PR 42154 for a
137 /* The statement this access belongs to. */
140 /* Next group representative for this aggregate. */
141 struct access *next_grp;
143 /* Pointer to the group representative. Pointer to itself if the struct is
144 the representative. */
145 struct access *group_representative;
147 /* If this access has any children (in terms of the definition above), this
148 points to the first one. */
149 struct access *first_child;
151 /* In intraprocedural SRA, pointer to the next sibling in the access tree as
152 described above. In IPA-SRA this is a pointer to the next access
153 belonging to the same group (having the same representative). */
154 struct access *next_sibling;
156 /* Pointers to the first and last element in the linked list of assign
158 struct assign_link *first_link, *last_link;
160 /* Pointer to the next access in the work queue. */
161 struct access *next_queued;
163 /* Replacement variable for this access "region." Never to be accessed
164 directly, always only by the means of get_access_replacement() and only
165 when grp_to_be_replaced flag is set. */
166 tree replacement_decl;
168 /* Is this particular access write access? */
171 /* Is this access an access to a non-addressable field? */
172 unsigned non_addressable : 1;
174 /* Is this access currently in the work queue? */
175 unsigned grp_queued : 1;
177 /* Does this group contain a write access? This flag is propagated down the
179 unsigned grp_write : 1;
181 /* Does this group contain a read access? This flag is propagated down the
183 unsigned grp_read : 1;
185 /* Does this group contain a read access that comes from an assignment
186 statement? This flag is propagated down the access tree. */
187 unsigned grp_assignment_read : 1;
189 /* Does this group contain a write access that comes from an assignment
190 statement? This flag is propagated down the access tree. */
191 unsigned grp_assignment_write : 1;
193 /* Does this group contain a read access through a scalar type? This flag is
194 not propagated in the access tree in any direction. */
195 unsigned grp_scalar_read : 1;
197 /* Does this group contain a write access through a scalar type? This flag
198 is not propagated in the access tree in any direction. */
199 unsigned grp_scalar_write : 1;
201 /* Is this access an artificial one created to scalarize some record
203 unsigned grp_total_scalarization : 1;
205 /* Other passes of the analysis use this bit to make function
206 analyze_access_subtree create scalar replacements for this group if
208 unsigned grp_hint : 1;
210 /* Is the subtree rooted in this access fully covered by scalar
212 unsigned grp_covered : 1;
214 /* If set to true, this access and all below it in an access tree must not be
216 unsigned grp_unscalarizable_region : 1;
218 /* Whether data have been written to parts of the aggregate covered by this
219 access which is not to be scalarized. This flag is propagated up in the
221 unsigned grp_unscalarized_data : 1;
223 /* Does this access and/or group contain a write access through a
225 unsigned grp_partial_lhs : 1;
227 /* Set when a scalar replacement should be created for this variable. */
228 unsigned grp_to_be_replaced : 1;
230 /* Set when we want a replacement for the sole purpose of having it in
231 generated debug statements. */
232 unsigned grp_to_be_debug_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;
254 /* Alloc pool for allocating access structures. */
255 static alloc_pool access_pool;
257 /* A structure linking lhs and rhs accesses from an aggregate assignment. They
258 are used to propagate subaccesses from rhs to lhs as long as they don't
259 conflict with what is already there. */
262 struct access *lacc, *racc;
263 struct assign_link *next;
266 /* Alloc pool for allocating assign link structures. */
267 static alloc_pool link_pool;
269 /* Base (tree) -> Vector (vec<access_p> *) map. */
270 static struct pointer_map_t *base_access_vec;
272 /* Set of candidates. */
273 static bitmap candidate_bitmap;
274 static htab_t candidates;
276 /* For a candidate UID return the candidates decl. */
279 candidate (unsigned uid)
281 struct tree_decl_minimal t;
283 return (tree) htab_find_with_hash (candidates, &t, uid);
286 /* Bitmap of candidates which we should try to entirely scalarize away and
287 those which cannot be (because they are and need be used as a whole). */
288 static bitmap should_scalarize_away_bitmap, cannot_scalarize_away_bitmap;
290 /* Obstack for creation of fancy names. */
291 static struct obstack name_obstack;
293 /* Head of a linked list of accesses that need to have its subaccesses
294 propagated to their assignment counterparts. */
295 static struct access *work_queue_head;
297 /* Number of parameters of the analyzed function when doing early ipa SRA. */
298 static int func_param_count;
300 /* scan_function sets the following to true if it encounters a call to
301 __builtin_apply_args. */
302 static bool encountered_apply_args;
304 /* Set by scan_function when it finds a recursive call. */
305 static bool encountered_recursive_call;
307 /* Set by scan_function when it finds a recursive call with less actual
308 arguments than formal parameters.. */
309 static bool encountered_unchangable_recursive_call;
311 /* This is a table in which for each basic block and parameter there is a
312 distance (offset + size) in that parameter which is dereferenced and
313 accessed in that BB. */
314 static HOST_WIDE_INT *bb_dereferences;
315 /* Bitmap of BBs that can cause the function to "stop" progressing by
316 returning, throwing externally, looping infinitely or calling a function
317 which might abort etc.. */
318 static bitmap final_bbs;
320 /* Representative of no accesses at all. */
321 static struct access no_accesses_representant;
323 /* Predicate to test the special value. */
326 no_accesses_p (struct access *access)
328 return access == &no_accesses_representant;
331 /* Dump contents of ACCESS to file F in a human friendly way. If GRP is true,
332 representative fields are dumped, otherwise those which only describe the
333 individual access are. */
337 /* Number of processed aggregates is readily available in
338 analyze_all_variable_accesses and so is not stored here. */
340 /* Number of created scalar replacements. */
343 /* Number of times sra_modify_expr or sra_modify_assign themselves changed an
347 /* Number of statements created by generate_subtree_copies. */
350 /* Number of statements created by load_assign_lhs_subreplacements. */
353 /* Number of times sra_modify_assign has deleted a statement. */
356 /* Number of times sra_modify_assign has to deal with subaccesses of LHS and
357 RHS reparately due to type conversions or nonexistent matching
359 int separate_lhs_rhs_handling;
361 /* Number of parameters that were removed because they were unused. */
362 int deleted_unused_parameters;
364 /* Number of scalars passed as parameters by reference that have been
365 converted to be passed by value. */
366 int scalar_by_ref_to_by_val;
368 /* Number of aggregate parameters that were replaced by one or more of their
370 int aggregate_params_reduced;
372 /* Numbber of components created when splitting aggregate parameters. */
373 int param_reductions_created;
377 dump_access (FILE *f, struct access *access, bool grp)
379 fprintf (f, "access { ");
380 fprintf (f, "base = (%d)'", DECL_UID (access->base));
381 print_generic_expr (f, access->base, 0);
382 fprintf (f, "', offset = " HOST_WIDE_INT_PRINT_DEC, access->offset);
383 fprintf (f, ", size = " HOST_WIDE_INT_PRINT_DEC, access->size);
384 fprintf (f, ", expr = ");
385 print_generic_expr (f, access->expr, 0);
386 fprintf (f, ", type = ");
387 print_generic_expr (f, access->type, 0);
389 fprintf (f, ", grp_read = %d, grp_write = %d, grp_assignment_read = %d, "
390 "grp_assignment_write = %d, grp_scalar_read = %d, "
391 "grp_scalar_write = %d, grp_total_scalarization = %d, "
392 "grp_hint = %d, grp_covered = %d, "
393 "grp_unscalarizable_region = %d, grp_unscalarized_data = %d, "
394 "grp_partial_lhs = %d, grp_to_be_replaced = %d, "
395 "grp_to_be_debug_replaced = %d, grp_maybe_modified = %d, "
396 "grp_not_necessarilly_dereferenced = %d\n",
397 access->grp_read, access->grp_write, access->grp_assignment_read,
398 access->grp_assignment_write, access->grp_scalar_read,
399 access->grp_scalar_write, access->grp_total_scalarization,
400 access->grp_hint, access->grp_covered,
401 access->grp_unscalarizable_region, access->grp_unscalarized_data,
402 access->grp_partial_lhs, access->grp_to_be_replaced,
403 access->grp_to_be_debug_replaced, access->grp_maybe_modified,
404 access->grp_not_necessarilly_dereferenced);
406 fprintf (f, ", write = %d, grp_total_scalarization = %d, "
407 "grp_partial_lhs = %d\n",
408 access->write, access->grp_total_scalarization,
409 access->grp_partial_lhs);
412 /* Dump a subtree rooted in ACCESS to file F, indent by LEVEL. */
415 dump_access_tree_1 (FILE *f, struct access *access, int level)
421 for (i = 0; i < level; i++)
422 fputs ("* ", dump_file);
424 dump_access (f, access, true);
426 if (access->first_child)
427 dump_access_tree_1 (f, access->first_child, level + 1);
429 access = access->next_sibling;
434 /* Dump all access trees for a variable, given the pointer to the first root in
438 dump_access_tree (FILE *f, struct access *access)
440 for (; access; access = access->next_grp)
441 dump_access_tree_1 (f, access, 0);
444 /* Return true iff ACC is non-NULL and has subaccesses. */
447 access_has_children_p (struct access *acc)
449 return acc && acc->first_child;
452 /* Return true iff ACC is (partly) covered by at least one replacement. */
455 access_has_replacements_p (struct access *acc)
457 struct access *child;
458 if (acc->grp_to_be_replaced)
460 for (child = acc->first_child; child; child = child->next_sibling)
461 if (access_has_replacements_p (child))
466 /* Return a vector of pointers to accesses for the variable given in BASE or
467 NULL if there is none. */
469 static vec<access_p> *
470 get_base_access_vector (tree base)
474 slot = pointer_map_contains (base_access_vec, base);
478 return *(vec<access_p> **) slot;
481 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
482 in ACCESS. Return NULL if it cannot be found. */
484 static struct access *
485 find_access_in_subtree (struct access *access, HOST_WIDE_INT offset,
488 while (access && (access->offset != offset || access->size != size))
490 struct access *child = access->first_child;
492 while (child && (child->offset + child->size <= offset))
493 child = child->next_sibling;
500 /* Return the first group representative for DECL or NULL if none exists. */
502 static struct access *
503 get_first_repr_for_decl (tree base)
505 vec<access_p> *access_vec;
507 access_vec = get_base_access_vector (base);
511 return (*access_vec)[0];
514 /* Find an access representative for the variable BASE and given OFFSET and
515 SIZE. Requires that access trees have already been built. Return NULL if
516 it cannot be found. */
518 static struct access *
519 get_var_base_offset_size_access (tree base, HOST_WIDE_INT offset,
522 struct access *access;
524 access = get_first_repr_for_decl (base);
525 while (access && (access->offset + access->size <= offset))
526 access = access->next_grp;
530 return find_access_in_subtree (access, offset, size);
533 /* Add LINK to the linked list of assign links of RACC. */
535 add_link_to_rhs (struct access *racc, struct assign_link *link)
537 gcc_assert (link->racc == racc);
539 if (!racc->first_link)
541 gcc_assert (!racc->last_link);
542 racc->first_link = link;
545 racc->last_link->next = link;
547 racc->last_link = link;
551 /* Move all link structures in their linked list in OLD_RACC to the linked list
554 relink_to_new_repr (struct access *new_racc, struct access *old_racc)
556 if (!old_racc->first_link)
558 gcc_assert (!old_racc->last_link);
562 if (new_racc->first_link)
564 gcc_assert (!new_racc->last_link->next);
565 gcc_assert (!old_racc->last_link || !old_racc->last_link->next);
567 new_racc->last_link->next = old_racc->first_link;
568 new_racc->last_link = old_racc->last_link;
572 gcc_assert (!new_racc->last_link);
574 new_racc->first_link = old_racc->first_link;
575 new_racc->last_link = old_racc->last_link;
577 old_racc->first_link = old_racc->last_link = NULL;
580 /* Add ACCESS to the work queue (which is actually a stack). */
583 add_access_to_work_queue (struct access *access)
585 if (!access->grp_queued)
587 gcc_assert (!access->next_queued);
588 access->next_queued = work_queue_head;
589 access->grp_queued = 1;
590 work_queue_head = access;
594 /* Pop an access from the work queue, and return it, assuming there is one. */
596 static struct access *
597 pop_access_from_work_queue (void)
599 struct access *access = work_queue_head;
601 work_queue_head = access->next_queued;
602 access->next_queued = NULL;
603 access->grp_queued = 0;
608 /* Allocate necessary structures. */
611 sra_initialize (void)
613 candidate_bitmap = BITMAP_ALLOC (NULL);
614 candidates = htab_create (vec_safe_length (cfun->local_decls) / 2,
615 uid_decl_map_hash, uid_decl_map_eq, NULL);
616 should_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
617 cannot_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
618 gcc_obstack_init (&name_obstack);
619 access_pool = create_alloc_pool ("SRA accesses", sizeof (struct access), 16);
620 link_pool = create_alloc_pool ("SRA links", sizeof (struct assign_link), 16);
621 base_access_vec = pointer_map_create ();
622 memset (&sra_stats, 0, sizeof (sra_stats));
623 encountered_apply_args = false;
624 encountered_recursive_call = false;
625 encountered_unchangable_recursive_call = false;
628 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
631 delete_base_accesses (const void *key ATTRIBUTE_UNUSED, void **value,
632 void *data ATTRIBUTE_UNUSED)
634 vec<access_p> *access_vec = (vec<access_p> *) *value;
635 vec_free (access_vec);
639 /* Deallocate all general structures. */
642 sra_deinitialize (void)
644 BITMAP_FREE (candidate_bitmap);
645 htab_delete (candidates);
646 BITMAP_FREE (should_scalarize_away_bitmap);
647 BITMAP_FREE (cannot_scalarize_away_bitmap);
648 free_alloc_pool (access_pool);
649 free_alloc_pool (link_pool);
650 obstack_free (&name_obstack, NULL);
652 pointer_map_traverse (base_access_vec, delete_base_accesses, NULL);
653 pointer_map_destroy (base_access_vec);
656 /* Remove DECL from candidates for SRA and write REASON to the dump file if
659 disqualify_candidate (tree decl, const char *reason)
661 if (bitmap_clear_bit (candidate_bitmap, DECL_UID (decl)))
662 htab_clear_slot (candidates,
663 htab_find_slot_with_hash (candidates, decl,
664 DECL_UID (decl), NO_INSERT));
666 if (dump_file && (dump_flags & TDF_DETAILS))
668 fprintf (dump_file, "! Disqualifying ");
669 print_generic_expr (dump_file, decl, 0);
670 fprintf (dump_file, " - %s\n", reason);
674 /* Return true iff the type contains a field or an element which does not allow
678 type_internals_preclude_sra_p (tree type, const char **msg)
683 switch (TREE_CODE (type))
687 case QUAL_UNION_TYPE:
688 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
689 if (TREE_CODE (fld) == FIELD_DECL)
691 tree ft = TREE_TYPE (fld);
693 if (TREE_THIS_VOLATILE (fld))
695 *msg = "volatile structure field";
698 if (!DECL_FIELD_OFFSET (fld))
700 *msg = "no structure field offset";
703 if (!DECL_SIZE (fld))
705 *msg = "zero structure field size";
708 if (!host_integerp (DECL_FIELD_OFFSET (fld), 1))
710 *msg = "structure field offset not fixed";
713 if (!host_integerp (DECL_SIZE (fld), 1))
715 *msg = "structure field size not fixed";
718 if (!host_integerp (bit_position (fld), 0))
720 *msg = "structure field size too big";
723 if (AGGREGATE_TYPE_P (ft)
724 && int_bit_position (fld) % BITS_PER_UNIT != 0)
726 *msg = "structure field is bit field";
730 if (AGGREGATE_TYPE_P (ft) && type_internals_preclude_sra_p (ft, msg))
737 et = TREE_TYPE (type);
739 if (TYPE_VOLATILE (et))
741 *msg = "element type is volatile";
745 if (AGGREGATE_TYPE_P (et) && type_internals_preclude_sra_p (et, msg))
755 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
756 base variable if it is. Return T if it is not an SSA_NAME. */
759 get_ssa_base_param (tree t)
761 if (TREE_CODE (t) == SSA_NAME)
763 if (SSA_NAME_IS_DEFAULT_DEF (t))
764 return SSA_NAME_VAR (t);
771 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
772 belongs to, unless the BB has already been marked as a potentially
776 mark_parm_dereference (tree base, HOST_WIDE_INT dist, gimple stmt)
778 basic_block bb = gimple_bb (stmt);
779 int idx, parm_index = 0;
782 if (bitmap_bit_p (final_bbs, bb->index))
785 for (parm = DECL_ARGUMENTS (current_function_decl);
786 parm && parm != base;
787 parm = DECL_CHAIN (parm))
790 gcc_assert (parm_index < func_param_count);
792 idx = bb->index * func_param_count + parm_index;
793 if (bb_dereferences[idx] < dist)
794 bb_dereferences[idx] = dist;
797 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
798 the three fields. Also add it to the vector of accesses corresponding to
799 the base. Finally, return the new access. */
801 static struct access *
802 create_access_1 (tree base, HOST_WIDE_INT offset, HOST_WIDE_INT size)
805 struct access *access;
808 access = (struct access *) pool_alloc (access_pool);
809 memset (access, 0, sizeof (struct access));
811 access->offset = offset;
814 slot = pointer_map_contains (base_access_vec, base);
816 v = (vec<access_p> *) *slot;
820 v->safe_push (access);
823 pointer_map_insert (base_access_vec, base)) = v;
828 /* Create and insert access for EXPR. Return created access, or NULL if it is
831 static struct access *
832 create_access (tree expr, gimple stmt, bool write)
834 struct access *access;
835 HOST_WIDE_INT offset, size, max_size;
837 bool ptr, unscalarizable_region = false;
839 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
841 if (sra_mode == SRA_MODE_EARLY_IPA
842 && TREE_CODE (base) == MEM_REF)
844 base = get_ssa_base_param (TREE_OPERAND (base, 0));
852 if (!DECL_P (base) || !bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
855 if (sra_mode == SRA_MODE_EARLY_IPA)
857 if (size < 0 || size != max_size)
859 disqualify_candidate (base, "Encountered a variable sized access.");
862 if (TREE_CODE (expr) == COMPONENT_REF
863 && DECL_BIT_FIELD (TREE_OPERAND (expr, 1)))
865 disqualify_candidate (base, "Encountered a bit-field access.");
868 gcc_checking_assert ((offset % BITS_PER_UNIT) == 0);
871 mark_parm_dereference (base, offset + size, stmt);
875 if (size != max_size)
878 unscalarizable_region = true;
882 disqualify_candidate (base, "Encountered an unconstrained access.");
887 access = create_access_1 (base, offset, size);
889 access->type = TREE_TYPE (expr);
890 access->write = write;
891 access->grp_unscalarizable_region = unscalarizable_region;
894 if (TREE_CODE (expr) == COMPONENT_REF
895 && DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1)))
896 access->non_addressable = 1;
902 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
903 register types or (recursively) records with only these two kinds of fields.
904 It also returns false if any of these records contains a bit-field. */
907 type_consists_of_records_p (tree type)
911 if (TREE_CODE (type) != RECORD_TYPE)
914 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
915 if (TREE_CODE (fld) == FIELD_DECL)
917 tree ft = TREE_TYPE (fld);
919 if (DECL_BIT_FIELD (fld))
922 if (!is_gimple_reg_type (ft)
923 && !type_consists_of_records_p (ft))
930 /* Create total_scalarization accesses for all scalar type fields in DECL that
931 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
932 must be the top-most VAR_DECL representing the variable, OFFSET must be the
933 offset of DECL within BASE. REF must be the memory reference expression for
937 completely_scalarize_record (tree base, tree decl, HOST_WIDE_INT offset,
940 tree fld, decl_type = TREE_TYPE (decl);
942 for (fld = TYPE_FIELDS (decl_type); fld; fld = DECL_CHAIN (fld))
943 if (TREE_CODE (fld) == FIELD_DECL)
945 HOST_WIDE_INT pos = offset + int_bit_position (fld);
946 tree ft = TREE_TYPE (fld);
947 tree nref = build3 (COMPONENT_REF, TREE_TYPE (fld), ref, fld,
950 if (is_gimple_reg_type (ft))
952 struct access *access;
955 size = tree_low_cst (DECL_SIZE (fld), 1);
956 access = create_access_1 (base, pos, size);
959 access->grp_total_scalarization = 1;
960 /* Accesses for intraprocedural SRA can have their stmt NULL. */
963 completely_scalarize_record (base, fld, pos, nref);
967 /* Create total_scalarization accesses for all scalar type fields in VAR and
968 for VAR a a whole. VAR must be of a RECORD_TYPE conforming to
969 type_consists_of_records_p. */
972 completely_scalarize_var (tree var)
974 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (var), 1);
975 struct access *access;
977 access = create_access_1 (var, 0, size);
979 access->type = TREE_TYPE (var);
980 access->grp_total_scalarization = 1;
982 completely_scalarize_record (var, var, 0, var);
985 /* Search the given tree for a declaration by skipping handled components and
986 exclude it from the candidates. */
989 disqualify_base_of_expr (tree t, const char *reason)
991 t = get_base_address (t);
992 if (sra_mode == SRA_MODE_EARLY_IPA
993 && TREE_CODE (t) == MEM_REF)
994 t = get_ssa_base_param (TREE_OPERAND (t, 0));
997 disqualify_candidate (t, reason);
1000 /* Scan expression EXPR and create access structures for all accesses to
1001 candidates for scalarization. Return the created access or NULL if none is
1004 static struct access *
1005 build_access_from_expr_1 (tree expr, gimple stmt, bool write)
1007 struct access *ret = NULL;
1010 if (TREE_CODE (expr) == BIT_FIELD_REF
1011 || TREE_CODE (expr) == IMAGPART_EXPR
1012 || TREE_CODE (expr) == REALPART_EXPR)
1014 expr = TREE_OPERAND (expr, 0);
1018 partial_ref = false;
1020 /* We need to dive through V_C_Es in order to get the size of its parameter
1021 and not the result type. Ada produces such statements. We are also
1022 capable of handling the topmost V_C_E but not any of those buried in other
1023 handled components. */
1024 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
1025 expr = TREE_OPERAND (expr, 0);
1027 if (contains_view_convert_expr_p (expr))
1029 disqualify_base_of_expr (expr, "V_C_E under a different handled "
1034 switch (TREE_CODE (expr))
1037 if (TREE_CODE (TREE_OPERAND (expr, 0)) != ADDR_EXPR
1038 && sra_mode != SRA_MODE_EARLY_IPA)
1046 case ARRAY_RANGE_REF:
1047 ret = create_access (expr, stmt, write);
1054 if (write && partial_ref && ret)
1055 ret->grp_partial_lhs = 1;
1060 /* Scan expression EXPR and create access structures for all accesses to
1061 candidates for scalarization. Return true if any access has been inserted.
1062 STMT must be the statement from which the expression is taken, WRITE must be
1063 true if the expression is a store and false otherwise. */
1066 build_access_from_expr (tree expr, gimple stmt, bool write)
1068 struct access *access;
1070 access = build_access_from_expr_1 (expr, stmt, write);
1073 /* This means the aggregate is accesses as a whole in a way other than an
1074 assign statement and thus cannot be removed even if we had a scalar
1075 replacement for everything. */
1076 if (cannot_scalarize_away_bitmap)
1077 bitmap_set_bit (cannot_scalarize_away_bitmap, DECL_UID (access->base));
1083 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
1084 modes in which it matters, return true iff they have been disqualified. RHS
1085 may be NULL, in that case ignore it. If we scalarize an aggregate in
1086 intra-SRA we may need to add statements after each statement. This is not
1087 possible if a statement unconditionally has to end the basic block. */
1089 disqualify_ops_if_throwing_stmt (gimple stmt, tree lhs, tree rhs)
1091 if ((sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1092 && (stmt_can_throw_internal (stmt) || stmt_ends_bb_p (stmt)))
1094 disqualify_base_of_expr (lhs, "LHS of a throwing stmt.");
1096 disqualify_base_of_expr (rhs, "RHS of a throwing stmt.");
1102 /* Scan expressions occurring in STMT, create access structures for all accesses
1103 to candidates for scalarization and remove those candidates which occur in
1104 statements or expressions that prevent them from being split apart. Return
1105 true if any access has been inserted. */
1108 build_accesses_from_assign (gimple stmt)
1111 struct access *lacc, *racc;
1113 if (!gimple_assign_single_p (stmt)
1114 /* Scope clobbers don't influence scalarization. */
1115 || gimple_clobber_p (stmt))
1118 lhs = gimple_assign_lhs (stmt);
1119 rhs = gimple_assign_rhs1 (stmt);
1121 if (disqualify_ops_if_throwing_stmt (stmt, lhs, rhs))
1124 racc = build_access_from_expr_1 (rhs, stmt, false);
1125 lacc = build_access_from_expr_1 (lhs, stmt, true);
1128 lacc->grp_assignment_write = 1;
1132 racc->grp_assignment_read = 1;
1133 if (should_scalarize_away_bitmap && !gimple_has_volatile_ops (stmt)
1134 && !is_gimple_reg_type (racc->type))
1135 bitmap_set_bit (should_scalarize_away_bitmap, DECL_UID (racc->base));
1139 && (sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1140 && !lacc->grp_unscalarizable_region
1141 && !racc->grp_unscalarizable_region
1142 && AGGREGATE_TYPE_P (TREE_TYPE (lhs))
1143 && lacc->size == racc->size
1144 && useless_type_conversion_p (lacc->type, racc->type))
1146 struct assign_link *link;
1148 link = (struct assign_link *) pool_alloc (link_pool);
1149 memset (link, 0, sizeof (struct assign_link));
1154 add_link_to_rhs (racc, link);
1157 return lacc || racc;
1160 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1161 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1164 asm_visit_addr (gimple stmt ATTRIBUTE_UNUSED, tree op,
1165 void *data ATTRIBUTE_UNUSED)
1167 op = get_base_address (op);
1170 disqualify_candidate (op, "Non-scalarizable GIMPLE_ASM operand.");
1175 /* Return true iff callsite CALL has at least as many actual arguments as there
1176 are formal parameters of the function currently processed by IPA-SRA. */
1179 callsite_has_enough_arguments_p (gimple call)
1181 return gimple_call_num_args (call) >= (unsigned) func_param_count;
1184 /* Scan function and look for interesting expressions and create access
1185 structures for them. Return true iff any access is created. */
1188 scan_function (void)
1195 gimple_stmt_iterator gsi;
1196 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1198 gimple stmt = gsi_stmt (gsi);
1202 if (final_bbs && stmt_can_throw_external (stmt))
1203 bitmap_set_bit (final_bbs, bb->index);
1204 switch (gimple_code (stmt))
1207 t = gimple_return_retval (stmt);
1209 ret |= build_access_from_expr (t, stmt, false);
1211 bitmap_set_bit (final_bbs, bb->index);
1215 ret |= build_accesses_from_assign (stmt);
1219 for (i = 0; i < gimple_call_num_args (stmt); i++)
1220 ret |= build_access_from_expr (gimple_call_arg (stmt, i),
1223 if (sra_mode == SRA_MODE_EARLY_IPA)
1225 tree dest = gimple_call_fndecl (stmt);
1226 int flags = gimple_call_flags (stmt);
1230 if (DECL_BUILT_IN_CLASS (dest) == BUILT_IN_NORMAL
1231 && DECL_FUNCTION_CODE (dest) == BUILT_IN_APPLY_ARGS)
1232 encountered_apply_args = true;
1233 if (cgraph_get_node (dest)
1234 == cgraph_get_node (current_function_decl))
1236 encountered_recursive_call = true;
1237 if (!callsite_has_enough_arguments_p (stmt))
1238 encountered_unchangable_recursive_call = true;
1243 && (flags & (ECF_CONST | ECF_PURE)) == 0)
1244 bitmap_set_bit (final_bbs, bb->index);
1247 t = gimple_call_lhs (stmt);
1248 if (t && !disqualify_ops_if_throwing_stmt (stmt, t, NULL))
1249 ret |= build_access_from_expr (t, stmt, true);
1253 walk_stmt_load_store_addr_ops (stmt, NULL, NULL, NULL,
1256 bitmap_set_bit (final_bbs, bb->index);
1258 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
1260 t = TREE_VALUE (gimple_asm_input_op (stmt, i));
1261 ret |= build_access_from_expr (t, stmt, false);
1263 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
1265 t = TREE_VALUE (gimple_asm_output_op (stmt, i));
1266 ret |= build_access_from_expr (t, stmt, true);
1279 /* Helper of QSORT function. There are pointers to accesses in the array. An
1280 access is considered smaller than another if it has smaller offset or if the
1281 offsets are the same but is size is bigger. */
1284 compare_access_positions (const void *a, const void *b)
1286 const access_p *fp1 = (const access_p *) a;
1287 const access_p *fp2 = (const access_p *) b;
1288 const access_p f1 = *fp1;
1289 const access_p f2 = *fp2;
1291 if (f1->offset != f2->offset)
1292 return f1->offset < f2->offset ? -1 : 1;
1294 if (f1->size == f2->size)
1296 if (f1->type == f2->type)
1298 /* Put any non-aggregate type before any aggregate type. */
1299 else if (!is_gimple_reg_type (f1->type)
1300 && is_gimple_reg_type (f2->type))
1302 else if (is_gimple_reg_type (f1->type)
1303 && !is_gimple_reg_type (f2->type))
1305 /* Put any complex or vector type before any other scalar type. */
1306 else if (TREE_CODE (f1->type) != COMPLEX_TYPE
1307 && TREE_CODE (f1->type) != VECTOR_TYPE
1308 && (TREE_CODE (f2->type) == COMPLEX_TYPE
1309 || TREE_CODE (f2->type) == VECTOR_TYPE))
1311 else if ((TREE_CODE (f1->type) == COMPLEX_TYPE
1312 || TREE_CODE (f1->type) == VECTOR_TYPE)
1313 && TREE_CODE (f2->type) != COMPLEX_TYPE
1314 && TREE_CODE (f2->type) != VECTOR_TYPE)
1316 /* Put the integral type with the bigger precision first. */
1317 else if (INTEGRAL_TYPE_P (f1->type)
1318 && INTEGRAL_TYPE_P (f2->type))
1319 return TYPE_PRECISION (f2->type) - TYPE_PRECISION (f1->type);
1320 /* Put any integral type with non-full precision last. */
1321 else if (INTEGRAL_TYPE_P (f1->type)
1322 && (TREE_INT_CST_LOW (TYPE_SIZE (f1->type))
1323 != TYPE_PRECISION (f1->type)))
1325 else if (INTEGRAL_TYPE_P (f2->type)
1326 && (TREE_INT_CST_LOW (TYPE_SIZE (f2->type))
1327 != TYPE_PRECISION (f2->type)))
1329 /* Stabilize the sort. */
1330 return TYPE_UID (f1->type) - TYPE_UID (f2->type);
1333 /* We want the bigger accesses first, thus the opposite operator in the next
1335 return f1->size > f2->size ? -1 : 1;
1339 /* Append a name of the declaration to the name obstack. A helper function for
1343 make_fancy_decl_name (tree decl)
1347 tree name = DECL_NAME (decl);
1349 obstack_grow (&name_obstack, IDENTIFIER_POINTER (name),
1350 IDENTIFIER_LENGTH (name));
1353 sprintf (buffer, "D%u", DECL_UID (decl));
1354 obstack_grow (&name_obstack, buffer, strlen (buffer));
1358 /* Helper for make_fancy_name. */
1361 make_fancy_name_1 (tree expr)
1368 make_fancy_decl_name (expr);
1372 switch (TREE_CODE (expr))
1375 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1376 obstack_1grow (&name_obstack, '$');
1377 make_fancy_decl_name (TREE_OPERAND (expr, 1));
1381 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1382 obstack_1grow (&name_obstack, '$');
1383 /* Arrays with only one element may not have a constant as their
1385 index = TREE_OPERAND (expr, 1);
1386 if (TREE_CODE (index) != INTEGER_CST)
1388 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC, TREE_INT_CST_LOW (index));
1389 obstack_grow (&name_obstack, buffer, strlen (buffer));
1393 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1397 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1398 if (!integer_zerop (TREE_OPERAND (expr, 1)))
1400 obstack_1grow (&name_obstack, '$');
1401 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC,
1402 TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)));
1403 obstack_grow (&name_obstack, buffer, strlen (buffer));
1410 gcc_unreachable (); /* we treat these as scalars. */
1417 /* Create a human readable name for replacement variable of ACCESS. */
1420 make_fancy_name (tree expr)
1422 make_fancy_name_1 (expr);
1423 obstack_1grow (&name_obstack, '\0');
1424 return XOBFINISH (&name_obstack, char *);
1427 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1428 EXP_TYPE at the given OFFSET. If BASE is something for which
1429 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1430 to insert new statements either before or below the current one as specified
1431 by INSERT_AFTER. This function is not capable of handling bitfields.
1433 BASE must be either a declaration or a memory reference that has correct
1434 alignment ifformation embeded in it (e.g. a pre-existing one in SRA). */
1437 build_ref_for_offset (location_t loc, tree base, HOST_WIDE_INT offset,
1438 tree exp_type, gimple_stmt_iterator *gsi,
1441 tree prev_base = base;
1444 HOST_WIDE_INT base_offset;
1445 unsigned HOST_WIDE_INT misalign;
1448 gcc_checking_assert (offset % BITS_PER_UNIT == 0);
1449 get_object_alignment_1 (base, &align, &misalign);
1450 base = get_addr_base_and_unit_offset (base, &base_offset);
1452 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1453 offset such as array[var_index]. */
1459 gcc_checking_assert (gsi);
1460 tmp = make_ssa_name (build_pointer_type (TREE_TYPE (prev_base)), NULL);
1461 addr = build_fold_addr_expr (unshare_expr (prev_base));
1462 STRIP_USELESS_TYPE_CONVERSION (addr);
1463 stmt = gimple_build_assign (tmp, addr);
1464 gimple_set_location (stmt, loc);
1466 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
1468 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1470 off = build_int_cst (reference_alias_ptr_type (prev_base),
1471 offset / BITS_PER_UNIT);
1474 else if (TREE_CODE (base) == MEM_REF)
1476 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1477 base_offset + offset / BITS_PER_UNIT);
1478 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off);
1479 base = unshare_expr (TREE_OPERAND (base, 0));
1483 off = build_int_cst (reference_alias_ptr_type (base),
1484 base_offset + offset / BITS_PER_UNIT);
1485 base = build_fold_addr_expr (unshare_expr (base));
1488 misalign = (misalign + offset) & (align - 1);
1490 align = (misalign & -misalign);
1491 if (align < TYPE_ALIGN (exp_type))
1492 exp_type = build_aligned_type (exp_type, align);
1494 mem_ref = fold_build2_loc (loc, MEM_REF, exp_type, base, off);
1495 if (TREE_THIS_VOLATILE (prev_base))
1496 TREE_THIS_VOLATILE (mem_ref) = 1;
1497 if (TREE_SIDE_EFFECTS (prev_base))
1498 TREE_SIDE_EFFECTS (mem_ref) = 1;
1502 /* Construct a memory reference to a part of an aggregate BASE at the given
1503 OFFSET and of the same type as MODEL. In case this is a reference to a
1504 bit-field, the function will replicate the last component_ref of model's
1505 expr to access it. GSI and INSERT_AFTER have the same meaning as in
1506 build_ref_for_offset. */
1509 build_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1510 struct access *model, gimple_stmt_iterator *gsi,
1513 if (TREE_CODE (model->expr) == COMPONENT_REF
1514 && DECL_BIT_FIELD (TREE_OPERAND (model->expr, 1)))
1516 /* This access represents a bit-field. */
1517 tree t, exp_type, fld = TREE_OPERAND (model->expr, 1);
1519 offset -= int_bit_position (fld);
1520 exp_type = TREE_TYPE (TREE_OPERAND (model->expr, 0));
1521 t = build_ref_for_offset (loc, base, offset, exp_type, gsi, insert_after);
1522 return fold_build3_loc (loc, COMPONENT_REF, TREE_TYPE (fld), t, fld,
1526 return build_ref_for_offset (loc, base, offset, model->type,
1530 /* Attempt to build a memory reference that we could but into a gimple
1531 debug_bind statement. Similar to build_ref_for_model but punts if it has to
1532 create statements and return s NULL instead. This function also ignores
1533 alignment issues and so its results should never end up in non-debug
1537 build_debug_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1538 struct access *model)
1540 HOST_WIDE_INT base_offset;
1543 if (TREE_CODE (model->expr) == COMPONENT_REF
1544 && DECL_BIT_FIELD (TREE_OPERAND (model->expr, 1)))
1547 base = get_addr_base_and_unit_offset (base, &base_offset);
1550 if (TREE_CODE (base) == MEM_REF)
1552 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1553 base_offset + offset / BITS_PER_UNIT);
1554 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off);
1555 base = unshare_expr (TREE_OPERAND (base, 0));
1559 off = build_int_cst (reference_alias_ptr_type (base),
1560 base_offset + offset / BITS_PER_UNIT);
1561 base = build_fold_addr_expr (unshare_expr (base));
1564 return fold_build2_loc (loc, MEM_REF, model->type, base, off);
1567 /* Construct a memory reference consisting of component_refs and array_refs to
1568 a part of an aggregate *RES (which is of type TYPE). The requested part
1569 should have type EXP_TYPE at be the given OFFSET. This function might not
1570 succeed, it returns true when it does and only then *RES points to something
1571 meaningful. This function should be used only to build expressions that we
1572 might need to present to user (e.g. in warnings). In all other situations,
1573 build_ref_for_model or build_ref_for_offset should be used instead. */
1576 build_user_friendly_ref_for_offset (tree *res, tree type, HOST_WIDE_INT offset,
1582 tree tr_size, index, minidx;
1583 HOST_WIDE_INT el_size;
1585 if (offset == 0 && exp_type
1586 && types_compatible_p (exp_type, type))
1589 switch (TREE_CODE (type))
1592 case QUAL_UNION_TYPE:
1594 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
1596 HOST_WIDE_INT pos, size;
1597 tree tr_pos, expr, *expr_ptr;
1599 if (TREE_CODE (fld) != FIELD_DECL)
1602 tr_pos = bit_position (fld);
1603 if (!tr_pos || !host_integerp (tr_pos, 1))
1605 pos = TREE_INT_CST_LOW (tr_pos);
1606 gcc_assert (TREE_CODE (type) == RECORD_TYPE || pos == 0);
1607 tr_size = DECL_SIZE (fld);
1608 if (!tr_size || !host_integerp (tr_size, 1))
1610 size = TREE_INT_CST_LOW (tr_size);
1616 else if (pos > offset || (pos + size) <= offset)
1619 expr = build3 (COMPONENT_REF, TREE_TYPE (fld), *res, fld,
1622 if (build_user_friendly_ref_for_offset (expr_ptr, TREE_TYPE (fld),
1623 offset - pos, exp_type))
1632 tr_size = TYPE_SIZE (TREE_TYPE (type));
1633 if (!tr_size || !host_integerp (tr_size, 1))
1635 el_size = tree_low_cst (tr_size, 1);
1637 minidx = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
1638 if (TREE_CODE (minidx) != INTEGER_CST || el_size == 0)
1640 index = build_int_cst (TYPE_DOMAIN (type), offset / el_size);
1641 if (!integer_zerop (minidx))
1642 index = int_const_binop (PLUS_EXPR, index, minidx);
1643 *res = build4 (ARRAY_REF, TREE_TYPE (type), *res, index,
1644 NULL_TREE, NULL_TREE);
1645 offset = offset % el_size;
1646 type = TREE_TYPE (type);
1661 /* Return true iff TYPE is stdarg va_list type. */
1664 is_va_list_type (tree type)
1666 return TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (va_list_type_node);
1669 /* Print message to dump file why a variable was rejected. */
1672 reject (tree var, const char *msg)
1674 if (dump_file && (dump_flags & TDF_DETAILS))
1676 fprintf (dump_file, "Rejected (%d): %s: ", DECL_UID (var), msg);
1677 print_generic_expr (dump_file, var, 0);
1678 fprintf (dump_file, "\n");
1682 /* Return true if VAR is a candidate for SRA. */
1685 maybe_add_sra_candidate (tree var)
1687 tree type = TREE_TYPE (var);
1691 if (!AGGREGATE_TYPE_P (type))
1693 reject (var, "not aggregate");
1696 if (needs_to_live_in_memory (var))
1698 reject (var, "needs to live in memory");
1701 if (TREE_THIS_VOLATILE (var))
1703 reject (var, "is volatile");
1706 if (!COMPLETE_TYPE_P (type))
1708 reject (var, "has incomplete type");
1711 if (!host_integerp (TYPE_SIZE (type), 1))
1713 reject (var, "type size not fixed");
1716 if (tree_low_cst (TYPE_SIZE (type), 1) == 0)
1718 reject (var, "type size is zero");
1721 if (type_internals_preclude_sra_p (type, &msg))
1726 if (/* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1727 we also want to schedule it rather late. Thus we ignore it in
1729 (sra_mode == SRA_MODE_EARLY_INTRA
1730 && is_va_list_type (type)))
1732 reject (var, "is va_list");
1736 bitmap_set_bit (candidate_bitmap, DECL_UID (var));
1737 slot = htab_find_slot_with_hash (candidates, var, DECL_UID (var), INSERT);
1738 *slot = (void *) var;
1740 if (dump_file && (dump_flags & TDF_DETAILS))
1742 fprintf (dump_file, "Candidate (%d): ", DECL_UID (var));
1743 print_generic_expr (dump_file, var, 0);
1744 fprintf (dump_file, "\n");
1750 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1751 those with type which is suitable for scalarization. */
1754 find_var_candidates (void)
1760 for (parm = DECL_ARGUMENTS (current_function_decl);
1762 parm = DECL_CHAIN (parm))
1763 ret |= maybe_add_sra_candidate (parm);
1765 FOR_EACH_LOCAL_DECL (cfun, i, var)
1767 if (TREE_CODE (var) != VAR_DECL)
1770 ret |= maybe_add_sra_candidate (var);
1776 /* Sort all accesses for the given variable, check for partial overlaps and
1777 return NULL if there are any. If there are none, pick a representative for
1778 each combination of offset and size and create a linked list out of them.
1779 Return the pointer to the first representative and make sure it is the first
1780 one in the vector of accesses. */
1782 static struct access *
1783 sort_and_splice_var_accesses (tree var)
1785 int i, j, access_count;
1786 struct access *res, **prev_acc_ptr = &res;
1787 vec<access_p> *access_vec;
1789 HOST_WIDE_INT low = -1, high = 0;
1791 access_vec = get_base_access_vector (var);
1794 access_count = access_vec->length ();
1796 /* Sort by <OFFSET, SIZE>. */
1797 access_vec->qsort (compare_access_positions);
1800 while (i < access_count)
1802 struct access *access = (*access_vec)[i];
1803 bool grp_write = access->write;
1804 bool grp_read = !access->write;
1805 bool grp_scalar_write = access->write
1806 && is_gimple_reg_type (access->type);
1807 bool grp_scalar_read = !access->write
1808 && is_gimple_reg_type (access->type);
1809 bool grp_assignment_read = access->grp_assignment_read;
1810 bool grp_assignment_write = access->grp_assignment_write;
1811 bool multiple_scalar_reads = false;
1812 bool total_scalarization = access->grp_total_scalarization;
1813 bool grp_partial_lhs = access->grp_partial_lhs;
1814 bool first_scalar = is_gimple_reg_type (access->type);
1815 bool unscalarizable_region = access->grp_unscalarizable_region;
1817 if (first || access->offset >= high)
1820 low = access->offset;
1821 high = access->offset + access->size;
1823 else if (access->offset > low && access->offset + access->size > high)
1826 gcc_assert (access->offset >= low
1827 && access->offset + access->size <= high);
1830 while (j < access_count)
1832 struct access *ac2 = (*access_vec)[j];
1833 if (ac2->offset != access->offset || ac2->size != access->size)
1838 grp_scalar_write = (grp_scalar_write
1839 || is_gimple_reg_type (ac2->type));
1844 if (is_gimple_reg_type (ac2->type))
1846 if (grp_scalar_read)
1847 multiple_scalar_reads = true;
1849 grp_scalar_read = true;
1852 grp_assignment_read |= ac2->grp_assignment_read;
1853 grp_assignment_write |= ac2->grp_assignment_write;
1854 grp_partial_lhs |= ac2->grp_partial_lhs;
1855 unscalarizable_region |= ac2->grp_unscalarizable_region;
1856 total_scalarization |= ac2->grp_total_scalarization;
1857 relink_to_new_repr (access, ac2);
1859 /* If there are both aggregate-type and scalar-type accesses with
1860 this combination of size and offset, the comparison function
1861 should have put the scalars first. */
1862 gcc_assert (first_scalar || !is_gimple_reg_type (ac2->type));
1863 ac2->group_representative = access;
1869 access->group_representative = access;
1870 access->grp_write = grp_write;
1871 access->grp_read = grp_read;
1872 access->grp_scalar_read = grp_scalar_read;
1873 access->grp_scalar_write = grp_scalar_write;
1874 access->grp_assignment_read = grp_assignment_read;
1875 access->grp_assignment_write = grp_assignment_write;
1876 access->grp_hint = multiple_scalar_reads || total_scalarization;
1877 access->grp_total_scalarization = total_scalarization;
1878 access->grp_partial_lhs = grp_partial_lhs;
1879 access->grp_unscalarizable_region = unscalarizable_region;
1880 if (access->first_link)
1881 add_access_to_work_queue (access);
1883 *prev_acc_ptr = access;
1884 prev_acc_ptr = &access->next_grp;
1887 gcc_assert (res == (*access_vec)[0]);
1891 /* Create a variable for the given ACCESS which determines the type, name and a
1892 few other properties. Return the variable declaration and store it also to
1893 ACCESS->replacement. */
1896 create_access_replacement (struct access *access)
1900 if (access->grp_to_be_debug_replaced)
1902 repl = create_tmp_var_raw (access->type, NULL);
1903 DECL_CONTEXT (repl) = current_function_decl;
1906 repl = create_tmp_var (access->type, "SR");
1907 if (TREE_CODE (access->type) == COMPLEX_TYPE
1908 || TREE_CODE (access->type) == VECTOR_TYPE)
1910 if (!access->grp_partial_lhs)
1911 DECL_GIMPLE_REG_P (repl) = 1;
1913 else if (access->grp_partial_lhs
1914 && is_gimple_reg_type (access->type))
1915 TREE_ADDRESSABLE (repl) = 1;
1917 DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
1918 DECL_ARTIFICIAL (repl) = 1;
1919 DECL_IGNORED_P (repl) = DECL_IGNORED_P (access->base);
1921 if (DECL_NAME (access->base)
1922 && !DECL_IGNORED_P (access->base)
1923 && !DECL_ARTIFICIAL (access->base))
1925 char *pretty_name = make_fancy_name (access->expr);
1926 tree debug_expr = unshare_expr_without_location (access->expr), d;
1929 DECL_NAME (repl) = get_identifier (pretty_name);
1930 obstack_free (&name_obstack, pretty_name);
1932 /* Get rid of any SSA_NAMEs embedded in debug_expr,
1933 as DECL_DEBUG_EXPR isn't considered when looking for still
1934 used SSA_NAMEs and thus they could be freed. All debug info
1935 generation cares is whether something is constant or variable
1936 and that get_ref_base_and_extent works properly on the
1937 expression. It cannot handle accesses at a non-constant offset
1938 though, so just give up in those cases. */
1939 for (d = debug_expr;
1940 !fail && (handled_component_p (d) || TREE_CODE (d) == MEM_REF);
1941 d = TREE_OPERAND (d, 0))
1942 switch (TREE_CODE (d))
1945 case ARRAY_RANGE_REF:
1946 if (TREE_OPERAND (d, 1)
1947 && TREE_CODE (TREE_OPERAND (d, 1)) != INTEGER_CST)
1949 if (TREE_OPERAND (d, 3)
1950 && TREE_CODE (TREE_OPERAND (d, 3)) != INTEGER_CST)
1954 if (TREE_OPERAND (d, 2)
1955 && TREE_CODE (TREE_OPERAND (d, 2)) != INTEGER_CST)
1959 if (TREE_CODE (TREE_OPERAND (d, 0)) != ADDR_EXPR)
1962 d = TREE_OPERAND (d, 0);
1969 SET_DECL_DEBUG_EXPR (repl, debug_expr);
1970 DECL_DEBUG_EXPR_IS_FROM (repl) = 1;
1972 if (access->grp_no_warning)
1973 TREE_NO_WARNING (repl) = 1;
1975 TREE_NO_WARNING (repl) = TREE_NO_WARNING (access->base);
1978 TREE_NO_WARNING (repl) = 1;
1982 if (access->grp_to_be_debug_replaced)
1984 fprintf (dump_file, "Created a debug-only replacement for ");
1985 print_generic_expr (dump_file, access->base, 0);
1986 fprintf (dump_file, " offset: %u, size: %u\n",
1987 (unsigned) access->offset, (unsigned) access->size);
1991 fprintf (dump_file, "Created a replacement for ");
1992 print_generic_expr (dump_file, access->base, 0);
1993 fprintf (dump_file, " offset: %u, size: %u: ",
1994 (unsigned) access->offset, (unsigned) access->size);
1995 print_generic_expr (dump_file, repl, 0);
1996 fprintf (dump_file, "\n");
1999 sra_stats.replacements++;
2004 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
2007 get_access_replacement (struct access *access)
2009 gcc_checking_assert (access->replacement_decl);
2010 return access->replacement_decl;
2014 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
2015 linked list along the way. Stop when *ACCESS is NULL or the access pointed
2016 to it is not "within" the root. Return false iff some accesses partially
2020 build_access_subtree (struct access **access)
2022 struct access *root = *access, *last_child = NULL;
2023 HOST_WIDE_INT limit = root->offset + root->size;
2025 *access = (*access)->next_grp;
2026 while (*access && (*access)->offset + (*access)->size <= limit)
2029 root->first_child = *access;
2031 last_child->next_sibling = *access;
2032 last_child = *access;
2034 if (!build_access_subtree (access))
2038 if (*access && (*access)->offset < limit)
2044 /* Build a tree of access representatives, ACCESS is the pointer to the first
2045 one, others are linked in a list by the next_grp field. Return false iff
2046 some accesses partially overlap. */
2049 build_access_trees (struct access *access)
2053 struct access *root = access;
2055 if (!build_access_subtree (&access))
2057 root->next_grp = access;
2062 /* Return true if expr contains some ARRAY_REFs into a variable bounded
2066 expr_with_var_bounded_array_refs_p (tree expr)
2068 while (handled_component_p (expr))
2070 if (TREE_CODE (expr) == ARRAY_REF
2071 && !host_integerp (array_ref_low_bound (expr), 0))
2073 expr = TREE_OPERAND (expr, 0);
2078 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
2079 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
2080 sorts of access flags appropriately along the way, notably always set
2081 grp_read and grp_assign_read according to MARK_READ and grp_write when
2084 Creating a replacement for a scalar access is considered beneficial if its
2085 grp_hint is set (this means we are either attempting total scalarization or
2086 there is more than one direct read access) or according to the following
2089 Access written to through a scalar type (once or more times)
2091 | Written to in an assignment statement
2093 | | Access read as scalar _once_
2095 | | | Read in an assignment statement
2097 | | | | Scalarize Comment
2098 -----------------------------------------------------------------------------
2099 0 0 0 0 No access for the scalar
2100 0 0 0 1 No access for the scalar
2101 0 0 1 0 No Single read - won't help
2102 0 0 1 1 No The same case
2103 0 1 0 0 No access for the scalar
2104 0 1 0 1 No access for the scalar
2105 0 1 1 0 Yes s = *g; return s.i;
2106 0 1 1 1 Yes The same case as above
2107 1 0 0 0 No Won't help
2108 1 0 0 1 Yes s.i = 1; *g = s;
2109 1 0 1 0 Yes s.i = 5; g = s.i;
2110 1 0 1 1 Yes The same case as above
2111 1 1 0 0 No Won't help.
2112 1 1 0 1 Yes s.i = 1; *g = s;
2113 1 1 1 0 Yes s = *g; return s.i;
2114 1 1 1 1 Yes Any of the above yeses */
2117 analyze_access_subtree (struct access *root, struct access *parent,
2118 bool allow_replacements)
2120 struct access *child;
2121 HOST_WIDE_INT limit = root->offset + root->size;
2122 HOST_WIDE_INT covered_to = root->offset;
2123 bool scalar = is_gimple_reg_type (root->type);
2124 bool hole = false, sth_created = false;
2128 if (parent->grp_read)
2130 if (parent->grp_assignment_read)
2131 root->grp_assignment_read = 1;
2132 if (parent->grp_write)
2133 root->grp_write = 1;
2134 if (parent->grp_assignment_write)
2135 root->grp_assignment_write = 1;
2136 if (parent->grp_total_scalarization)
2137 root->grp_total_scalarization = 1;
2140 if (root->grp_unscalarizable_region)
2141 allow_replacements = false;
2143 if (allow_replacements && expr_with_var_bounded_array_refs_p (root->expr))
2144 allow_replacements = false;
2146 for (child = root->first_child; child; child = child->next_sibling)
2148 hole |= covered_to < child->offset;
2149 sth_created |= analyze_access_subtree (child, root,
2150 allow_replacements && !scalar);
2152 root->grp_unscalarized_data |= child->grp_unscalarized_data;
2153 root->grp_total_scalarization &= child->grp_total_scalarization;
2154 if (child->grp_covered)
2155 covered_to += child->size;
2160 if (allow_replacements && scalar && !root->first_child
2162 || ((root->grp_scalar_read || root->grp_assignment_read)
2163 && (root->grp_scalar_write || root->grp_assignment_write))))
2165 /* Always create access replacements that cover the whole access.
2166 For integral types this means the precision has to match.
2167 Avoid assumptions based on the integral type kind, too. */
2168 if (INTEGRAL_TYPE_P (root->type)
2169 && (TREE_CODE (root->type) != INTEGER_TYPE
2170 || TYPE_PRECISION (root->type) != root->size)
2171 /* But leave bitfield accesses alone. */
2172 && (TREE_CODE (root->expr) != COMPONENT_REF
2173 || !DECL_BIT_FIELD (TREE_OPERAND (root->expr, 1))))
2175 tree rt = root->type;
2176 gcc_assert ((root->offset % BITS_PER_UNIT) == 0
2177 && (root->size % BITS_PER_UNIT) == 0);
2178 root->type = build_nonstandard_integer_type (root->size,
2179 TYPE_UNSIGNED (rt));
2180 root->expr = build_ref_for_offset (UNKNOWN_LOCATION,
2181 root->base, root->offset,
2182 root->type, NULL, false);
2184 if (dump_file && (dump_flags & TDF_DETAILS))
2186 fprintf (dump_file, "Changing the type of a replacement for ");
2187 print_generic_expr (dump_file, root->base, 0);
2188 fprintf (dump_file, " offset: %u, size: %u ",
2189 (unsigned) root->offset, (unsigned) root->size);
2190 fprintf (dump_file, " to an integer.\n");
2194 root->grp_to_be_replaced = 1;
2195 root->replacement_decl = create_access_replacement (root);
2201 if (allow_replacements
2202 && scalar && !root->first_child
2203 && (root->grp_scalar_write || root->grp_assignment_write)
2204 && !bitmap_bit_p (cannot_scalarize_away_bitmap,
2205 DECL_UID (root->base)))
2207 gcc_checking_assert (!root->grp_scalar_read
2208 && !root->grp_assignment_read);
2210 if (MAY_HAVE_DEBUG_STMTS)
2212 root->grp_to_be_debug_replaced = 1;
2213 root->replacement_decl = create_access_replacement (root);
2217 if (covered_to < limit)
2220 root->grp_total_scalarization = 0;
2223 if (!hole || root->grp_total_scalarization)
2224 root->grp_covered = 1;
2225 else if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
2226 root->grp_unscalarized_data = 1; /* not covered and written to */
2230 /* Analyze all access trees linked by next_grp by the means of
2231 analyze_access_subtree. */
2233 analyze_access_trees (struct access *access)
2239 if (analyze_access_subtree (access, NULL, true))
2241 access = access->next_grp;
2247 /* Return true iff a potential new child of LACC at offset OFFSET and with size
2248 SIZE would conflict with an already existing one. If exactly such a child
2249 already exists in LACC, store a pointer to it in EXACT_MATCH. */
2252 child_would_conflict_in_lacc (struct access *lacc, HOST_WIDE_INT norm_offset,
2253 HOST_WIDE_INT size, struct access **exact_match)
2255 struct access *child;
2257 for (child = lacc->first_child; child; child = child->next_sibling)
2259 if (child->offset == norm_offset && child->size == size)
2261 *exact_match = child;
2265 if (child->offset < norm_offset + size
2266 && child->offset + child->size > norm_offset)
2273 /* Create a new child access of PARENT, with all properties just like MODEL
2274 except for its offset and with its grp_write false and grp_read true.
2275 Return the new access or NULL if it cannot be created. Note that this access
2276 is created long after all splicing and sorting, it's not located in any
2277 access vector and is automatically a representative of its group. */
2279 static struct access *
2280 create_artificial_child_access (struct access *parent, struct access *model,
2281 HOST_WIDE_INT new_offset)
2283 struct access *access;
2284 struct access **child;
2285 tree expr = parent->base;
2287 gcc_assert (!model->grp_unscalarizable_region);
2289 access = (struct access *) pool_alloc (access_pool);
2290 memset (access, 0, sizeof (struct access));
2291 if (!build_user_friendly_ref_for_offset (&expr, TREE_TYPE (expr), new_offset,
2294 access->grp_no_warning = true;
2295 expr = build_ref_for_model (EXPR_LOCATION (parent->base), parent->base,
2296 new_offset, model, NULL, false);
2299 access->base = parent->base;
2300 access->expr = expr;
2301 access->offset = new_offset;
2302 access->size = model->size;
2303 access->type = model->type;
2304 access->grp_write = true;
2305 access->grp_read = false;
2307 child = &parent->first_child;
2308 while (*child && (*child)->offset < new_offset)
2309 child = &(*child)->next_sibling;
2311 access->next_sibling = *child;
2318 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2319 true if any new subaccess was created. Additionally, if RACC is a scalar
2320 access but LACC is not, change the type of the latter, if possible. */
2323 propagate_subaccesses_across_link (struct access *lacc, struct access *racc)
2325 struct access *rchild;
2326 HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
2329 if (is_gimple_reg_type (lacc->type)
2330 || lacc->grp_unscalarizable_region
2331 || racc->grp_unscalarizable_region)
2334 if (is_gimple_reg_type (racc->type))
2336 if (!lacc->first_child && !racc->first_child)
2338 tree t = lacc->base;
2340 lacc->type = racc->type;
2341 if (build_user_friendly_ref_for_offset (&t, TREE_TYPE (t),
2342 lacc->offset, racc->type))
2346 lacc->expr = build_ref_for_model (EXPR_LOCATION (lacc->base),
2347 lacc->base, lacc->offset,
2349 lacc->grp_no_warning = true;
2355 for (rchild = racc->first_child; rchild; rchild = rchild->next_sibling)
2357 struct access *new_acc = NULL;
2358 HOST_WIDE_INT norm_offset = rchild->offset + norm_delta;
2360 if (rchild->grp_unscalarizable_region)
2363 if (child_would_conflict_in_lacc (lacc, norm_offset, rchild->size,
2368 rchild->grp_hint = 1;
2369 new_acc->grp_hint |= new_acc->grp_read;
2370 if (rchild->first_child)
2371 ret |= propagate_subaccesses_across_link (new_acc, rchild);
2376 rchild->grp_hint = 1;
2377 new_acc = create_artificial_child_access (lacc, rchild, norm_offset);
2381 if (racc->first_child)
2382 propagate_subaccesses_across_link (new_acc, rchild);
2389 /* Propagate all subaccesses across assignment links. */
2392 propagate_all_subaccesses (void)
2394 while (work_queue_head)
2396 struct access *racc = pop_access_from_work_queue ();
2397 struct assign_link *link;
2399 gcc_assert (racc->first_link);
2401 for (link = racc->first_link; link; link = link->next)
2403 struct access *lacc = link->lacc;
2405 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (lacc->base)))
2407 lacc = lacc->group_representative;
2408 if (propagate_subaccesses_across_link (lacc, racc)
2409 && lacc->first_link)
2410 add_access_to_work_queue (lacc);
2415 /* Go through all accesses collected throughout the (intraprocedural) analysis
2416 stage, exclude overlapping ones, identify representatives and build trees
2417 out of them, making decisions about scalarization on the way. Return true
2418 iff there are any to-be-scalarized variables after this stage. */
2421 analyze_all_variable_accesses (void)
2424 bitmap tmp = BITMAP_ALLOC (NULL);
2426 unsigned i, max_total_scalarization_size;
2428 max_total_scalarization_size = UNITS_PER_WORD * BITS_PER_UNIT
2429 * MOVE_RATIO (optimize_function_for_speed_p (cfun));
2431 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
2432 if (bitmap_bit_p (should_scalarize_away_bitmap, i)
2433 && !bitmap_bit_p (cannot_scalarize_away_bitmap, i))
2435 tree var = candidate (i);
2437 if (TREE_CODE (var) == VAR_DECL
2438 && type_consists_of_records_p (TREE_TYPE (var)))
2440 if ((unsigned) tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1)
2441 <= max_total_scalarization_size)
2443 completely_scalarize_var (var);
2444 if (dump_file && (dump_flags & TDF_DETAILS))
2446 fprintf (dump_file, "Will attempt to totally scalarize ");
2447 print_generic_expr (dump_file, var, 0);
2448 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2451 else if (dump_file && (dump_flags & TDF_DETAILS))
2453 fprintf (dump_file, "Too big to totally scalarize: ");
2454 print_generic_expr (dump_file, var, 0);
2455 fprintf (dump_file, " (UID: %u)\n", DECL_UID (var));
2460 bitmap_copy (tmp, candidate_bitmap);
2461 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2463 tree var = candidate (i);
2464 struct access *access;
2466 access = sort_and_splice_var_accesses (var);
2467 if (!access || !build_access_trees (access))
2468 disqualify_candidate (var,
2469 "No or inhibitingly overlapping accesses.");
2472 propagate_all_subaccesses ();
2474 bitmap_copy (tmp, candidate_bitmap);
2475 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2477 tree var = candidate (i);
2478 struct access *access = get_first_repr_for_decl (var);
2480 if (analyze_access_trees (access))
2483 if (dump_file && (dump_flags & TDF_DETAILS))
2485 fprintf (dump_file, "\nAccess trees for ");
2486 print_generic_expr (dump_file, var, 0);
2487 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2488 dump_access_tree (dump_file, access);
2489 fprintf (dump_file, "\n");
2493 disqualify_candidate (var, "No scalar replacements to be created.");
2500 statistics_counter_event (cfun, "Scalarized aggregates", res);
2507 /* Generate statements copying scalar replacements of accesses within a subtree
2508 into or out of AGG. ACCESS, all its children, siblings and their children
2509 are to be processed. AGG is an aggregate type expression (can be a
2510 declaration but does not have to be, it can for example also be a mem_ref or
2511 a series of handled components). TOP_OFFSET is the offset of the processed
2512 subtree which has to be subtracted from offsets of individual accesses to
2513 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2514 replacements in the interval <start_offset, start_offset + chunk_size>,
2515 otherwise copy all. GSI is a statement iterator used to place the new
2516 statements. WRITE should be true when the statements should write from AGG
2517 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2518 statements will be added after the current statement in GSI, they will be
2519 added before the statement otherwise. */
2522 generate_subtree_copies (struct access *access, tree agg,
2523 HOST_WIDE_INT top_offset,
2524 HOST_WIDE_INT start_offset, HOST_WIDE_INT chunk_size,
2525 gimple_stmt_iterator *gsi, bool write,
2526 bool insert_after, location_t loc)
2530 if (chunk_size && access->offset >= start_offset + chunk_size)
2533 if (access->grp_to_be_replaced
2535 || access->offset + access->size > start_offset))
2537 tree expr, repl = get_access_replacement (access);
2540 expr = build_ref_for_model (loc, agg, access->offset - top_offset,
2541 access, gsi, insert_after);
2545 if (access->grp_partial_lhs)
2546 expr = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE,
2548 insert_after ? GSI_NEW_STMT
2550 stmt = gimple_build_assign (repl, expr);
2554 TREE_NO_WARNING (repl) = 1;
2555 if (access->grp_partial_lhs)
2556 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2558 insert_after ? GSI_NEW_STMT
2560 stmt = gimple_build_assign (expr, repl);
2562 gimple_set_location (stmt, loc);
2565 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2567 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2569 sra_stats.subtree_copies++;
2572 && access->grp_to_be_debug_replaced
2574 || access->offset + access->size > start_offset))
2577 tree drhs = build_debug_ref_for_model (loc, agg,
2578 access->offset - top_offset,
2580 ds = gimple_build_debug_bind (get_access_replacement (access),
2581 drhs, gsi_stmt (*gsi));
2583 gsi_insert_after (gsi, ds, GSI_NEW_STMT);
2585 gsi_insert_before (gsi, ds, GSI_SAME_STMT);
2588 if (access->first_child)
2589 generate_subtree_copies (access->first_child, agg, top_offset,
2590 start_offset, chunk_size, gsi,
2591 write, insert_after, loc);
2593 access = access->next_sibling;
2598 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2599 the root of the subtree to be processed. GSI is the statement iterator used
2600 for inserting statements which are added after the current statement if
2601 INSERT_AFTER is true or before it otherwise. */
2604 init_subtree_with_zero (struct access *access, gimple_stmt_iterator *gsi,
2605 bool insert_after, location_t loc)
2608 struct access *child;
2610 if (access->grp_to_be_replaced)
2614 stmt = gimple_build_assign (get_access_replacement (access),
2615 build_zero_cst (access->type));
2617 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2619 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2621 gimple_set_location (stmt, loc);
2623 else if (access->grp_to_be_debug_replaced)
2625 gimple ds = gimple_build_debug_bind (get_access_replacement (access),
2626 build_zero_cst (access->type),
2629 gsi_insert_after (gsi, ds, GSI_NEW_STMT);
2631 gsi_insert_before (gsi, ds, GSI_SAME_STMT);
2634 for (child = access->first_child; child; child = child->next_sibling)
2635 init_subtree_with_zero (child, gsi, insert_after, loc);
2638 /* Search for an access representative for the given expression EXPR and
2639 return it or NULL if it cannot be found. */
2641 static struct access *
2642 get_access_for_expr (tree expr)
2644 HOST_WIDE_INT offset, size, max_size;
2647 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2648 a different size than the size of its argument and we need the latter
2650 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
2651 expr = TREE_OPERAND (expr, 0);
2653 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
2654 if (max_size == -1 || !DECL_P (base))
2657 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
2660 return get_var_base_offset_size_access (base, offset, max_size);
2663 /* Replace the expression EXPR with a scalar replacement if there is one and
2664 generate other statements to do type conversion or subtree copying if
2665 necessary. GSI is used to place newly created statements, WRITE is true if
2666 the expression is being written to (it is on a LHS of a statement or output
2667 in an assembly statement). */
2670 sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write)
2673 struct access *access;
2676 if (TREE_CODE (*expr) == BIT_FIELD_REF)
2679 expr = &TREE_OPERAND (*expr, 0);
2684 if (TREE_CODE (*expr) == REALPART_EXPR || TREE_CODE (*expr) == IMAGPART_EXPR)
2685 expr = &TREE_OPERAND (*expr, 0);
2686 access = get_access_for_expr (*expr);
2689 type = TREE_TYPE (*expr);
2691 loc = gimple_location (gsi_stmt (*gsi));
2692 if (access->grp_to_be_replaced)
2694 tree repl = get_access_replacement (access);
2695 /* If we replace a non-register typed access simply use the original
2696 access expression to extract the scalar component afterwards.
2697 This happens if scalarizing a function return value or parameter
2698 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2699 gcc.c-torture/compile/20011217-1.c.
2701 We also want to use this when accessing a complex or vector which can
2702 be accessed as a different type too, potentially creating a need for
2703 type conversion (see PR42196) and when scalarized unions are involved
2704 in assembler statements (see PR42398). */
2705 if (!useless_type_conversion_p (type, access->type))
2709 ref = build_ref_for_model (loc, access->base, access->offset, access,
2716 if (access->grp_partial_lhs)
2717 ref = force_gimple_operand_gsi (gsi, ref, true, NULL_TREE,
2718 false, GSI_NEW_STMT);
2719 stmt = gimple_build_assign (repl, ref);
2720 gimple_set_location (stmt, loc);
2721 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2727 if (access->grp_partial_lhs)
2728 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2729 true, GSI_SAME_STMT);
2730 stmt = gimple_build_assign (ref, repl);
2731 gimple_set_location (stmt, loc);
2732 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2739 else if (write && access->grp_to_be_debug_replaced)
2741 gimple ds = gimple_build_debug_bind (get_access_replacement (access),
2744 gsi_insert_after (gsi, ds, GSI_NEW_STMT);
2747 if (access->first_child)
2749 HOST_WIDE_INT start_offset, chunk_size;
2751 && host_integerp (TREE_OPERAND (bfr, 1), 1)
2752 && host_integerp (TREE_OPERAND (bfr, 2), 1))
2754 chunk_size = tree_low_cst (TREE_OPERAND (bfr, 1), 1);
2755 start_offset = access->offset
2756 + tree_low_cst (TREE_OPERAND (bfr, 2), 1);
2759 start_offset = chunk_size = 0;
2761 generate_subtree_copies (access->first_child, access->base, 0,
2762 start_offset, chunk_size, gsi, write, write,
2768 /* Where scalar replacements of the RHS have been written to when a replacement
2769 of a LHS of an assigments cannot be direclty loaded from a replacement of
2771 enum unscalarized_data_handling { SRA_UDH_NONE, /* Nothing done so far. */
2772 SRA_UDH_RIGHT, /* Data flushed to the RHS. */
2773 SRA_UDH_LEFT }; /* Data flushed to the LHS. */
2775 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2776 base aggregate if there are unscalarized data or directly to LHS of the
2777 statement that is pointed to by GSI otherwise. */
2779 static enum unscalarized_data_handling
2780 handle_unscalarized_data_in_subtree (struct access *top_racc,
2781 gimple_stmt_iterator *gsi)
2783 if (top_racc->grp_unscalarized_data)
2785 generate_subtree_copies (top_racc->first_child, top_racc->base, 0, 0, 0,
2787 gimple_location (gsi_stmt (*gsi)));
2788 return SRA_UDH_RIGHT;
2792 tree lhs = gimple_assign_lhs (gsi_stmt (*gsi));
2793 generate_subtree_copies (top_racc->first_child, lhs, top_racc->offset,
2794 0, 0, gsi, false, false,
2795 gimple_location (gsi_stmt (*gsi)));
2796 return SRA_UDH_LEFT;
2801 /* Try to generate statements to load all sub-replacements in an access subtree
2802 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2803 If that is not possible, refresh the TOP_RACC base aggregate and load the
2804 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2805 copied. NEW_GSI is stmt iterator used for statement insertions after the
2806 original assignment, OLD_GSI is used to insert statements before the
2807 assignment. *REFRESHED keeps the information whether we have needed to
2808 refresh replacements of the LHS and from which side of the assignments this
2812 load_assign_lhs_subreplacements (struct access *lacc, struct access *top_racc,
2813 HOST_WIDE_INT left_offset,
2814 gimple_stmt_iterator *old_gsi,
2815 gimple_stmt_iterator *new_gsi,
2816 enum unscalarized_data_handling *refreshed)
2818 location_t loc = gimple_location (gsi_stmt (*old_gsi));
2819 for (lacc = lacc->first_child; lacc; lacc = lacc->next_sibling)
2821 HOST_WIDE_INT offset = lacc->offset - left_offset + top_racc->offset;
2823 if (lacc->grp_to_be_replaced)
2825 struct access *racc;
2829 racc = find_access_in_subtree (top_racc, offset, lacc->size);
2830 if (racc && racc->grp_to_be_replaced)
2832 rhs = get_access_replacement (racc);
2833 if (!useless_type_conversion_p (lacc->type, racc->type))
2834 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, lacc->type, rhs);
2836 if (racc->grp_partial_lhs && lacc->grp_partial_lhs)
2837 rhs = force_gimple_operand_gsi (old_gsi, rhs, true, NULL_TREE,
2838 true, GSI_SAME_STMT);
2842 /* No suitable access on the right hand side, need to load from
2843 the aggregate. See if we have to update it first... */
2844 if (*refreshed == SRA_UDH_NONE)
2845 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2848 if (*refreshed == SRA_UDH_LEFT)
2849 rhs = build_ref_for_model (loc, lacc->base, lacc->offset, lacc,
2852 rhs = build_ref_for_model (loc, top_racc->base, offset, lacc,
2854 if (lacc->grp_partial_lhs)
2855 rhs = force_gimple_operand_gsi (new_gsi, rhs, true, NULL_TREE,
2856 false, GSI_NEW_STMT);
2859 stmt = gimple_build_assign (get_access_replacement (lacc), rhs);
2860 gsi_insert_after (new_gsi, stmt, GSI_NEW_STMT);
2861 gimple_set_location (stmt, loc);
2863 sra_stats.subreplacements++;
2867 if (*refreshed == SRA_UDH_NONE
2868 && lacc->grp_read && !lacc->grp_covered)
2869 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2871 if (lacc && lacc->grp_to_be_debug_replaced)
2875 struct access *racc = find_access_in_subtree (top_racc, offset,
2878 if (racc && racc->grp_to_be_replaced)
2880 if (racc->grp_write)
2881 drhs = get_access_replacement (racc);
2885 else if (*refreshed == SRA_UDH_LEFT)
2886 drhs = build_debug_ref_for_model (loc, lacc->base, lacc->offset,
2888 else if (*refreshed == SRA_UDH_RIGHT)
2889 drhs = build_debug_ref_for_model (loc, top_racc->base, offset,
2893 ds = gimple_build_debug_bind (get_access_replacement (lacc),
2894 drhs, gsi_stmt (*old_gsi));
2895 gsi_insert_after (new_gsi, ds, GSI_NEW_STMT);
2899 if (lacc->first_child)
2900 load_assign_lhs_subreplacements (lacc, top_racc, left_offset,
2901 old_gsi, new_gsi, refreshed);
2905 /* Result code for SRA assignment modification. */
2906 enum assignment_mod_result { SRA_AM_NONE, /* nothing done for the stmt */
2907 SRA_AM_MODIFIED, /* stmt changed but not
2909 SRA_AM_REMOVED }; /* stmt eliminated */
2911 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2912 to the assignment and GSI is the statement iterator pointing at it. Returns
2913 the same values as sra_modify_assign. */
2915 static enum assignment_mod_result
2916 sra_modify_constructor_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2918 tree lhs = gimple_assign_lhs (*stmt);
2922 acc = get_access_for_expr (lhs);
2926 if (gimple_clobber_p (*stmt))
2928 /* Remove clobbers of fully scalarized variables, otherwise
2930 if (acc->grp_covered)
2932 unlink_stmt_vdef (*stmt);
2933 gsi_remove (gsi, true);
2934 release_defs (*stmt);
2935 return SRA_AM_REMOVED;
2941 loc = gimple_location (*stmt);
2942 if (vec_safe_length (CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt))) > 0)
2944 /* I have never seen this code path trigger but if it can happen the
2945 following should handle it gracefully. */
2946 if (access_has_children_p (acc))
2947 generate_subtree_copies (acc->first_child, acc->base, 0, 0, 0, gsi,
2949 return SRA_AM_MODIFIED;
2952 if (acc->grp_covered)
2954 init_subtree_with_zero (acc, gsi, false, loc);
2955 unlink_stmt_vdef (*stmt);
2956 gsi_remove (gsi, true);
2957 release_defs (*stmt);
2958 return SRA_AM_REMOVED;
2962 init_subtree_with_zero (acc, gsi, true, loc);
2963 return SRA_AM_MODIFIED;
2967 /* Create and return a new suitable default definition SSA_NAME for RACC which
2968 is an access describing an uninitialized part of an aggregate that is being
2972 get_repl_default_def_ssa_name (struct access *racc)
2974 gcc_checking_assert (!racc->grp_to_be_replaced &&
2975 !racc->grp_to_be_debug_replaced);
2976 if (!racc->replacement_decl)
2977 racc->replacement_decl = create_access_replacement (racc);
2978 return get_or_create_ssa_default_def (cfun, racc->replacement_decl);
2981 /* Return true if REF has an VIEW_CONVERT_EXPR or a COMPONENT_REF with a
2982 bit-field field declaration somewhere in it. */
2985 contains_vce_or_bfcref_p (const_tree ref)
2987 while (handled_component_p (ref))
2989 if (TREE_CODE (ref) == VIEW_CONVERT_EXPR
2990 || (TREE_CODE (ref) == COMPONENT_REF
2991 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))))
2993 ref = TREE_OPERAND (ref, 0);
2999 /* Examine both sides of the assignment statement pointed to by STMT, replace
3000 them with a scalare replacement if there is one and generate copying of
3001 replacements if scalarized aggregates have been used in the assignment. GSI
3002 is used to hold generated statements for type conversions and subtree
3005 static enum assignment_mod_result
3006 sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
3008 struct access *lacc, *racc;
3010 bool modify_this_stmt = false;
3011 bool force_gimple_rhs = false;
3013 gimple_stmt_iterator orig_gsi = *gsi;
3015 if (!gimple_assign_single_p (*stmt))
3017 lhs = gimple_assign_lhs (*stmt);
3018 rhs = gimple_assign_rhs1 (*stmt);
3020 if (TREE_CODE (rhs) == CONSTRUCTOR)
3021 return sra_modify_constructor_assign (stmt, gsi);
3023 if (TREE_CODE (rhs) == REALPART_EXPR || TREE_CODE (lhs) == REALPART_EXPR
3024 || TREE_CODE (rhs) == IMAGPART_EXPR || TREE_CODE (lhs) == IMAGPART_EXPR
3025 || TREE_CODE (rhs) == BIT_FIELD_REF || TREE_CODE (lhs) == BIT_FIELD_REF)
3027 modify_this_stmt = sra_modify_expr (gimple_assign_rhs1_ptr (*stmt),
3029 modify_this_stmt |= sra_modify_expr (gimple_assign_lhs_ptr (*stmt),
3031 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3034 lacc = get_access_for_expr (lhs);
3035 racc = get_access_for_expr (rhs);
3039 loc = gimple_location (*stmt);
3040 if (lacc && lacc->grp_to_be_replaced)
3042 lhs = get_access_replacement (lacc);
3043 gimple_assign_set_lhs (*stmt, lhs);
3044 modify_this_stmt = true;
3045 if (lacc->grp_partial_lhs)
3046 force_gimple_rhs = true;
3050 if (racc && racc->grp_to_be_replaced)
3052 rhs = get_access_replacement (racc);
3053 modify_this_stmt = true;
3054 if (racc->grp_partial_lhs)
3055 force_gimple_rhs = true;
3059 && !racc->grp_unscalarized_data
3060 && TREE_CODE (lhs) == SSA_NAME
3061 && !access_has_replacements_p (racc))
3063 rhs = get_repl_default_def_ssa_name (racc);
3064 modify_this_stmt = true;
3068 if (modify_this_stmt)
3070 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
3072 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
3073 ??? This should move to fold_stmt which we simply should
3074 call after building a VIEW_CONVERT_EXPR here. */
3075 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
3076 && !contains_bitfld_component_ref_p (lhs))
3078 lhs = build_ref_for_model (loc, lhs, 0, racc, gsi, false);
3079 gimple_assign_set_lhs (*stmt, lhs);
3081 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs))
3082 && !contains_vce_or_bfcref_p (rhs))
3083 rhs = build_ref_for_model (loc, rhs, 0, lacc, gsi, false);
3085 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
3087 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, TREE_TYPE (lhs),
3089 if (is_gimple_reg_type (TREE_TYPE (lhs))
3090 && TREE_CODE (lhs) != SSA_NAME)
3091 force_gimple_rhs = true;
3096 if (lacc && lacc->grp_to_be_debug_replaced)
3098 tree dlhs = get_access_replacement (lacc);
3099 tree drhs = unshare_expr (rhs);
3100 if (!useless_type_conversion_p (TREE_TYPE (dlhs), TREE_TYPE (drhs)))
3102 if (AGGREGATE_TYPE_P (TREE_TYPE (drhs))
3103 && !contains_vce_or_bfcref_p (drhs))
3104 drhs = build_debug_ref_for_model (loc, drhs, 0, lacc);
3106 && !useless_type_conversion_p (TREE_TYPE (dlhs),
3108 drhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR,
3109 TREE_TYPE (dlhs), drhs);
3111 gimple ds = gimple_build_debug_bind (dlhs, drhs, *stmt);
3112 gsi_insert_before (gsi, ds, GSI_SAME_STMT);
3115 /* From this point on, the function deals with assignments in between
3116 aggregates when at least one has scalar reductions of some of its
3117 components. There are three possible scenarios: Both the LHS and RHS have
3118 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
3120 In the first case, we would like to load the LHS components from RHS
3121 components whenever possible. If that is not possible, we would like to
3122 read it directly from the RHS (after updating it by storing in it its own
3123 components). If there are some necessary unscalarized data in the LHS,
3124 those will be loaded by the original assignment too. If neither of these
3125 cases happen, the original statement can be removed. Most of this is done
3126 by load_assign_lhs_subreplacements.
3128 In the second case, we would like to store all RHS scalarized components
3129 directly into LHS and if they cover the aggregate completely, remove the
3130 statement too. In the third case, we want the LHS components to be loaded
3131 directly from the RHS (DSE will remove the original statement if it
3134 This is a bit complex but manageable when types match and when unions do
3135 not cause confusion in a way that we cannot really load a component of LHS
3136 from the RHS or vice versa (the access representing this level can have
3137 subaccesses that are accessible only through a different union field at a
3138 higher level - different from the one used in the examined expression).
3141 Therefore, I specially handle a fourth case, happening when there is a
3142 specific type cast or it is impossible to locate a scalarized subaccess on
3143 the other side of the expression. If that happens, I simply "refresh" the
3144 RHS by storing in it is scalarized components leave the original statement
3145 there to do the copying and then load the scalar replacements of the LHS.
3146 This is what the first branch does. */
3148 if (modify_this_stmt
3149 || gimple_has_volatile_ops (*stmt)
3150 || contains_vce_or_bfcref_p (rhs)
3151 || contains_vce_or_bfcref_p (lhs))
3153 if (access_has_children_p (racc))
3154 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
3155 gsi, false, false, loc);
3156 if (access_has_children_p (lacc))
3157 generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
3158 gsi, true, true, loc);
3159 sra_stats.separate_lhs_rhs_handling++;
3161 /* This gimplification must be done after generate_subtree_copies,
3162 lest we insert the subtree copies in the middle of the gimplified
3164 if (force_gimple_rhs)
3165 rhs = force_gimple_operand_gsi (&orig_gsi, rhs, true, NULL_TREE,
3166 true, GSI_SAME_STMT);
3167 if (gimple_assign_rhs1 (*stmt) != rhs)
3169 modify_this_stmt = true;
3170 gimple_assign_set_rhs_from_tree (&orig_gsi, rhs);
3171 gcc_assert (*stmt == gsi_stmt (orig_gsi));
3174 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3178 if (access_has_children_p (lacc)
3179 && access_has_children_p (racc)
3180 /* When an access represents an unscalarizable region, it usually
3181 represents accesses with variable offset and thus must not be used
3182 to generate new memory accesses. */
3183 && !lacc->grp_unscalarizable_region
3184 && !racc->grp_unscalarizable_region)
3186 gimple_stmt_iterator orig_gsi = *gsi;
3187 enum unscalarized_data_handling refreshed;
3189 if (lacc->grp_read && !lacc->grp_covered)
3190 refreshed = handle_unscalarized_data_in_subtree (racc, gsi);
3192 refreshed = SRA_UDH_NONE;
3194 load_assign_lhs_subreplacements (lacc, racc, lacc->offset,
3195 &orig_gsi, gsi, &refreshed);
3196 if (refreshed != SRA_UDH_RIGHT)
3199 unlink_stmt_vdef (*stmt);
3200 gsi_remove (&orig_gsi, true);
3201 release_defs (*stmt);
3202 sra_stats.deleted++;
3203 return SRA_AM_REMOVED;
3208 if (access_has_children_p (racc)
3209 && !racc->grp_unscalarized_data)
3213 fprintf (dump_file, "Removing load: ");
3214 print_gimple_stmt (dump_file, *stmt, 0, 0);
3216 generate_subtree_copies (racc->first_child, lhs,
3217 racc->offset, 0, 0, gsi,
3219 gcc_assert (*stmt == gsi_stmt (*gsi));
3220 unlink_stmt_vdef (*stmt);
3221 gsi_remove (gsi, true);
3222 release_defs (*stmt);
3223 sra_stats.deleted++;
3224 return SRA_AM_REMOVED;
3226 /* Restore the aggregate RHS from its components so the
3227 prevailing aggregate copy does the right thing. */
3228 if (access_has_children_p (racc))
3229 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
3230 gsi, false, false, loc);
3231 /* Re-load the components of the aggregate copy destination.
3232 But use the RHS aggregate to load from to expose more
3233 optimization opportunities. */
3234 if (access_has_children_p (lacc))
3235 generate_subtree_copies (lacc->first_child, rhs, lacc->offset,
3236 0, 0, gsi, true, true, loc);
3243 /* Traverse the function body and all modifications as decided in
3244 analyze_all_variable_accesses. Return true iff the CFG has been
3248 sra_modify_function_body (void)
3250 bool cfg_changed = false;
3255 gimple_stmt_iterator gsi = gsi_start_bb (bb);
3256 while (!gsi_end_p (gsi))
3258 gimple stmt = gsi_stmt (gsi);
3259 enum assignment_mod_result assign_result;
3260 bool modified = false, deleted = false;
3264 switch (gimple_code (stmt))
3267 t = gimple_return_retval_ptr (stmt);
3268 if (*t != NULL_TREE)
3269 modified |= sra_modify_expr (t, &gsi, false);
3273 assign_result = sra_modify_assign (&stmt, &gsi);
3274 modified |= assign_result == SRA_AM_MODIFIED;
3275 deleted = assign_result == SRA_AM_REMOVED;
3279 /* Operands must be processed before the lhs. */
3280 for (i = 0; i < gimple_call_num_args (stmt); i++)
3282 t = gimple_call_arg_ptr (stmt, i);
3283 modified |= sra_modify_expr (t, &gsi, false);
3286 if (gimple_call_lhs (stmt))
3288 t = gimple_call_lhs_ptr (stmt);
3289 modified |= sra_modify_expr (t, &gsi, true);
3294 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
3296 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
3297 modified |= sra_modify_expr (t, &gsi, false);
3299 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
3301 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
3302 modified |= sra_modify_expr (t, &gsi, true);
3313 if (maybe_clean_eh_stmt (stmt)
3314 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
3325 /* Generate statements initializing scalar replacements of parts of function
3329 initialize_parameter_reductions (void)
3331 gimple_stmt_iterator gsi;
3332 gimple_seq seq = NULL;
3335 gsi = gsi_start (seq);
3336 for (parm = DECL_ARGUMENTS (current_function_decl);
3338 parm = DECL_CHAIN (parm))
3340 vec<access_p> *access_vec;
3341 struct access *access;
3343 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3345 access_vec = get_base_access_vector (parm);
3349 for (access = (*access_vec)[0];
3351 access = access->next_grp)
3352 generate_subtree_copies (access, parm, 0, 0, 0, &gsi, true, true,
3353 EXPR_LOCATION (parm));
3356 seq = gsi_seq (gsi);
3358 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR), seq);
3361 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
3362 it reveals there are components of some aggregates to be scalarized, it runs
3363 the required transformations. */
3365 perform_intra_sra (void)
3370 if (!find_var_candidates ())
3373 if (!scan_function ())
3376 if (!analyze_all_variable_accesses ())
3379 if (sra_modify_function_body ())
3380 ret = TODO_update_ssa | TODO_cleanup_cfg;
3382 ret = TODO_update_ssa;
3383 initialize_parameter_reductions ();
3385 statistics_counter_event (cfun, "Scalar replacements created",
3386 sra_stats.replacements);
3387 statistics_counter_event (cfun, "Modified expressions", sra_stats.exprs);
3388 statistics_counter_event (cfun, "Subtree copy stmts",
3389 sra_stats.subtree_copies);
3390 statistics_counter_event (cfun, "Subreplacement stmts",
3391 sra_stats.subreplacements);
3392 statistics_counter_event (cfun, "Deleted stmts", sra_stats.deleted);
3393 statistics_counter_event (cfun, "Separate LHS and RHS handling",
3394 sra_stats.separate_lhs_rhs_handling);
3397 sra_deinitialize ();
3401 /* Perform early intraprocedural SRA. */
3403 early_intra_sra (void)
3405 sra_mode = SRA_MODE_EARLY_INTRA;
3406 return perform_intra_sra ();
3409 /* Perform "late" intraprocedural SRA. */
3411 late_intra_sra (void)
3413 sra_mode = SRA_MODE_INTRA;
3414 return perform_intra_sra ();
3419 gate_intra_sra (void)
3421 return flag_tree_sra != 0 && dbg_cnt (tree_sra);
3425 struct gimple_opt_pass pass_sra_early =
3430 OPTGROUP_NONE, /* optinfo_flags */
3431 gate_intra_sra, /* gate */
3432 early_intra_sra, /* execute */
3435 0, /* static_pass_number */
3436 TV_TREE_SRA, /* tv_id */
3437 PROP_cfg | PROP_ssa, /* properties_required */
3438 0, /* properties_provided */
3439 0, /* properties_destroyed */
3440 0, /* todo_flags_start */
3443 | TODO_verify_ssa /* todo_flags_finish */
3447 struct gimple_opt_pass pass_sra =
3452 OPTGROUP_NONE, /* optinfo_flags */
3453 gate_intra_sra, /* gate */
3454 late_intra_sra, /* execute */
3457 0, /* static_pass_number */
3458 TV_TREE_SRA, /* tv_id */
3459 PROP_cfg | PROP_ssa, /* properties_required */
3460 0, /* properties_provided */
3461 0, /* properties_destroyed */
3462 TODO_update_address_taken, /* todo_flags_start */
3465 | TODO_verify_ssa /* todo_flags_finish */
3470 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3474 is_unused_scalar_param (tree parm)
3477 return (is_gimple_reg (parm)
3478 && (!(name = ssa_default_def (cfun, parm))
3479 || has_zero_uses (name)));
3482 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3483 examine whether there are any direct or otherwise infeasible ones. If so,
3484 return true, otherwise return false. PARM must be a gimple register with a
3485 non-NULL default definition. */
3488 ptr_parm_has_direct_uses (tree parm)
3490 imm_use_iterator ui;
3492 tree name = ssa_default_def (cfun, parm);
3495 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
3498 use_operand_p use_p;
3500 if (is_gimple_debug (stmt))
3503 /* Valid uses include dereferences on the lhs and the rhs. */
3504 if (gimple_has_lhs (stmt))
3506 tree lhs = gimple_get_lhs (stmt);
3507 while (handled_component_p (lhs))
3508 lhs = TREE_OPERAND (lhs, 0);
3509 if (TREE_CODE (lhs) == MEM_REF
3510 && TREE_OPERAND (lhs, 0) == name
3511 && integer_zerop (TREE_OPERAND (lhs, 1))
3512 && types_compatible_p (TREE_TYPE (lhs),
3513 TREE_TYPE (TREE_TYPE (name)))
3514 && !TREE_THIS_VOLATILE (lhs))
3517 if (gimple_assign_single_p (stmt))
3519 tree rhs = gimple_assign_rhs1 (stmt);
3520 while (handled_component_p (rhs))
3521 rhs = TREE_OPERAND (rhs, 0);
3522 if (TREE_CODE (rhs) == MEM_REF
3523 && TREE_OPERAND (rhs, 0) == name
3524 && integer_zerop (TREE_OPERAND (rhs, 1))
3525 && types_compatible_p (TREE_TYPE (rhs),
3526 TREE_TYPE (TREE_TYPE (name)))
3527 && !TREE_THIS_VOLATILE (rhs))
3530 else if (is_gimple_call (stmt))
3533 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3535 tree arg = gimple_call_arg (stmt, i);
3536 while (handled_component_p (arg))
3537 arg = TREE_OPERAND (arg, 0);
3538 if (TREE_CODE (arg) == MEM_REF
3539 && TREE_OPERAND (arg, 0) == name
3540 && integer_zerop (TREE_OPERAND (arg, 1))
3541 && types_compatible_p (TREE_TYPE (arg),
3542 TREE_TYPE (TREE_TYPE (name)))
3543 && !TREE_THIS_VOLATILE (arg))
3548 /* If the number of valid uses does not match the number of
3549 uses in this stmt there is an unhandled use. */
3550 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
3557 BREAK_FROM_IMM_USE_STMT (ui);
3563 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3564 them in candidate_bitmap. Note that these do not necessarily include
3565 parameter which are unused and thus can be removed. Return true iff any
3566 such candidate has been found. */
3569 find_param_candidates (void)
3576 for (parm = DECL_ARGUMENTS (current_function_decl);
3578 parm = DECL_CHAIN (parm))
3580 tree type = TREE_TYPE (parm);
3585 if (TREE_THIS_VOLATILE (parm)
3586 || TREE_ADDRESSABLE (parm)
3587 || (!is_gimple_reg_type (type) && is_va_list_type (type)))
3590 if (is_unused_scalar_param (parm))
3596 if (POINTER_TYPE_P (type))
3598 type = TREE_TYPE (type);
3600 if (TREE_CODE (type) == FUNCTION_TYPE
3601 || TYPE_VOLATILE (type)
3602 || (TREE_CODE (type) == ARRAY_TYPE
3603 && TYPE_NONALIASED_COMPONENT (type))
3604 || !is_gimple_reg (parm)
3605 || is_va_list_type (type)
3606 || ptr_parm_has_direct_uses (parm))
3609 else if (!AGGREGATE_TYPE_P (type))
3612 if (!COMPLETE_TYPE_P (type)
3613 || !host_integerp (TYPE_SIZE (type), 1)
3614 || tree_low_cst (TYPE_SIZE (type), 1) == 0
3615 || (AGGREGATE_TYPE_P (type)
3616 && type_internals_preclude_sra_p (type, &msg)))
3619 bitmap_set_bit (candidate_bitmap, DECL_UID (parm));
3620 slot = htab_find_slot_with_hash (candidates, parm,
3621 DECL_UID (parm), INSERT);
3622 *slot = (void *) parm;
3625 if (dump_file && (dump_flags & TDF_DETAILS))
3627 fprintf (dump_file, "Candidate (%d): ", DECL_UID (parm));
3628 print_generic_expr (dump_file, parm, 0);
3629 fprintf (dump_file, "\n");
3633 func_param_count = count;
3637 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3641 mark_maybe_modified (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef ATTRIBUTE_UNUSED,
3644 struct access *repr = (struct access *) data;
3646 repr->grp_maybe_modified = 1;
3650 /* Analyze what representatives (in linked lists accessible from
3651 REPRESENTATIVES) can be modified by side effects of statements in the
3652 current function. */
3655 analyze_modified_params (vec<access_p> representatives)
3659 for (i = 0; i < func_param_count; i++)
3661 struct access *repr;
3663 for (repr = representatives[i];
3665 repr = repr->next_grp)
3667 struct access *access;
3671 if (no_accesses_p (repr))
3673 if (!POINTER_TYPE_P (TREE_TYPE (repr->base))
3674 || repr->grp_maybe_modified)
3677 ao_ref_init (&ar, repr->expr);
3678 visited = BITMAP_ALLOC (NULL);
3679 for (access = repr; access; access = access->next_sibling)
3681 /* All accesses are read ones, otherwise grp_maybe_modified would
3682 be trivially set. */
3683 walk_aliased_vdefs (&ar, gimple_vuse (access->stmt),
3684 mark_maybe_modified, repr, &visited);
3685 if (repr->grp_maybe_modified)
3688 BITMAP_FREE (visited);
3693 /* Propagate distances in bb_dereferences in the opposite direction than the
3694 control flow edges, in each step storing the maximum of the current value
3695 and the minimum of all successors. These steps are repeated until the table
3696 stabilizes. Note that BBs which might terminate the functions (according to
3697 final_bbs bitmap) never updated in this way. */
3700 propagate_dereference_distances (void)
3702 vec<basic_block> queue;
3705 queue.create (last_basic_block_for_function (cfun));
3706 queue.quick_push (ENTRY_BLOCK_PTR);
3709 queue.quick_push (bb);
3713 while (!queue.is_empty ())
3717 bool change = false;
3723 if (bitmap_bit_p (final_bbs, bb->index))
3726 for (i = 0; i < func_param_count; i++)
3728 int idx = bb->index * func_param_count + i;
3730 HOST_WIDE_INT inh = 0;
3732 FOR_EACH_EDGE (e, ei, bb->succs)
3734 int succ_idx = e->dest->index * func_param_count + i;
3736 if (e->src == EXIT_BLOCK_PTR)
3742 inh = bb_dereferences [succ_idx];
3744 else if (bb_dereferences [succ_idx] < inh)
3745 inh = bb_dereferences [succ_idx];
3748 if (!first && bb_dereferences[idx] < inh)
3750 bb_dereferences[idx] = inh;
3755 if (change && !bitmap_bit_p (final_bbs, bb->index))
3756 FOR_EACH_EDGE (e, ei, bb->preds)
3761 e->src->aux = e->src;
3762 queue.quick_push (e->src);
3769 /* Dump a dereferences TABLE with heading STR to file F. */
3772 dump_dereferences_table (FILE *f, const char *str, HOST_WIDE_INT *table)
3776 fprintf (dump_file, str);
3777 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
3779 fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index));
3780 if (bb != EXIT_BLOCK_PTR)
3783 for (i = 0; i < func_param_count; i++)
3785 int idx = bb->index * func_param_count + i;
3786 fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", table[idx]);
3791 fprintf (dump_file, "\n");
3794 /* Determine what (parts of) parameters passed by reference that are not
3795 assigned to are not certainly dereferenced in this function and thus the
3796 dereferencing cannot be safely moved to the caller without potentially
3797 introducing a segfault. Mark such REPRESENTATIVES as
3798 grp_not_necessarilly_dereferenced.
3800 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3801 part is calculated rather than simple booleans are calculated for each
3802 pointer parameter to handle cases when only a fraction of the whole
3803 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3806 The maximum dereference distances for each pointer parameter and BB are
3807 already stored in bb_dereference. This routine simply propagates these
3808 values upwards by propagate_dereference_distances and then compares the
3809 distances of individual parameters in the ENTRY BB to the equivalent
3810 distances of each representative of a (fraction of a) parameter. */
3813 analyze_caller_dereference_legality (vec<access_p> representatives)
3817 if (dump_file && (dump_flags & TDF_DETAILS))
3818 dump_dereferences_table (dump_file,
3819 "Dereference table before propagation:\n",
3822 propagate_dereference_distances ();
3824 if (dump_file && (dump_flags & TDF_DETAILS))
3825 dump_dereferences_table (dump_file,
3826 "Dereference table after propagation:\n",
3829 for (i = 0; i < func_param_count; i++)
3831 struct access *repr = representatives[i];
3832 int idx = ENTRY_BLOCK_PTR->index * func_param_count + i;
3834 if (!repr || no_accesses_p (repr))
3839 if ((repr->offset + repr->size) > bb_dereferences[idx])
3840 repr->grp_not_necessarilly_dereferenced = 1;
3841 repr = repr->next_grp;
3847 /* Return the representative access for the parameter declaration PARM if it is
3848 a scalar passed by reference which is not written to and the pointer value
3849 is not used directly. Thus, if it is legal to dereference it in the caller
3850 and we can rule out modifications through aliases, such parameter should be
3851 turned into one passed by value. Return NULL otherwise. */
3853 static struct access *
3854 unmodified_by_ref_scalar_representative (tree parm)
3856 int i, access_count;
3857 struct access *repr;
3858 vec<access_p> *access_vec;
3860 access_vec = get_base_access_vector (parm);
3861 gcc_assert (access_vec);
3862 repr = (*access_vec)[0];
3865 repr->group_representative = repr;
3867 access_count = access_vec->length ();
3868 for (i = 1; i < access_count; i++)
3870 struct access *access = (*access_vec)[i];
3873 access->group_representative = repr;
3874 access->next_sibling = repr->next_sibling;
3875 repr->next_sibling = access;
3879 repr->grp_scalar_ptr = 1;
3883 /* Return true iff this ACCESS precludes IPA-SRA of the parameter it is
3884 associated with. REQ_ALIGN is the minimum required alignment. */
3887 access_precludes_ipa_sra_p (struct access *access, unsigned int req_align)
3889 unsigned int exp_align;
3890 /* Avoid issues such as the second simple testcase in PR 42025. The problem
3891 is incompatible assign in a call statement (and possibly even in asm
3892 statements). This can be relaxed by using a new temporary but only for
3893 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
3894 intraprocedural SRA we deal with this by keeping the old aggregate around,
3895 something we cannot do in IPA-SRA.) */
3897 && (is_gimple_call (access->stmt)
3898 || gimple_code (access->stmt) == GIMPLE_ASM))
3901 exp_align = get_object_alignment (access->expr);
3902 if (exp_align < req_align)
3909 /* Sort collected accesses for parameter PARM, identify representatives for
3910 each accessed region and link them together. Return NULL if there are
3911 different but overlapping accesses, return the special ptr value meaning
3912 there are no accesses for this parameter if that is the case and return the
3913 first representative otherwise. Set *RO_GRP if there is a group of accesses
3914 with only read (i.e. no write) accesses. */
3916 static struct access *
3917 splice_param_accesses (tree parm, bool *ro_grp)
3919 int i, j, access_count, group_count;
3920 int agg_size, total_size = 0;
3921 struct access *access, *res, **prev_acc_ptr = &res;
3922 vec<access_p> *access_vec;
3924 access_vec = get_base_access_vector (parm);
3926 return &no_accesses_representant;
3927 access_count = access_vec->length ();
3929 access_vec->qsort (compare_access_positions);
3934 while (i < access_count)
3938 access = (*access_vec)[i];
3939 modification = access->write;
3940 if (access_precludes_ipa_sra_p (access, TYPE_ALIGN (access->type)))
3942 a1_alias_type = reference_alias_ptr_type (access->expr);
3944 /* Access is about to become group representative unless we find some
3945 nasty overlap which would preclude us from breaking this parameter
3949 while (j < access_count)
3951 struct access *ac2 = (*access_vec)[j];
3952 if (ac2->offset != access->offset)
3954 /* All or nothing law for parameters. */
3955 if (access->offset + access->size > ac2->offset)
3960 else if (ac2->size != access->size)
3963 if (access_precludes_ipa_sra_p (ac2, TYPE_ALIGN (access->type))
3964 || (ac2->type != access->type
3965 && (TREE_ADDRESSABLE (ac2->type)
3966 || TREE_ADDRESSABLE (access->type)))
3967 || (reference_alias_ptr_type (ac2->expr) != a1_alias_type))
3970 modification |= ac2->write;
3971 ac2->group_representative = access;
3972 ac2->next_sibling = access->next_sibling;
3973 access->next_sibling = ac2;
3978 access->grp_maybe_modified = modification;
3981 *prev_acc_ptr = access;
3982 prev_acc_ptr = &access->next_grp;
3983 total_size += access->size;
3987 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3988 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3990 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3991 if (total_size >= agg_size)
3994 gcc_assert (group_count > 0);
3998 /* Decide whether parameters with representative accesses given by REPR should
3999 be reduced into components. */
4002 decide_one_param_reduction (struct access *repr)
4004 int total_size, cur_parm_size, agg_size, new_param_count, parm_size_limit;
4009 cur_parm_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
4010 gcc_assert (cur_parm_size > 0);
4012 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4015 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
4020 agg_size = cur_parm_size;
4026 fprintf (dump_file, "Evaluating PARAM group sizes for ");
4027 print_generic_expr (dump_file, parm, 0);
4028 fprintf (dump_file, " (UID: %u): \n", DECL_UID (parm));
4029 for (acc = repr; acc; acc = acc->next_grp)
4030 dump_access (dump_file, acc, true);
4034 new_param_count = 0;
4036 for (; repr; repr = repr->next_grp)
4038 gcc_assert (parm == repr->base);
4040 /* Taking the address of a non-addressable field is verboten. */
4041 if (by_ref && repr->non_addressable)
4044 /* Do not decompose a non-BLKmode param in a way that would
4045 create BLKmode params. Especially for by-reference passing
4046 (thus, pointer-type param) this is hardly worthwhile. */
4047 if (DECL_MODE (parm) != BLKmode
4048 && TYPE_MODE (repr->type) == BLKmode)
4051 if (!by_ref || (!repr->grp_maybe_modified
4052 && !repr->grp_not_necessarilly_dereferenced))
4053 total_size += repr->size;
4055 total_size += cur_parm_size;
4060 gcc_assert (new_param_count > 0);
4062 if (optimize_function_for_size_p (cfun))
4063 parm_size_limit = cur_parm_size;
4065 parm_size_limit = (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR)
4068 if (total_size < agg_size
4069 && total_size <= parm_size_limit)
4072 fprintf (dump_file, " ....will be split into %i components\n",
4074 return new_param_count;
4080 /* The order of the following enums is important, we need to do extra work for
4081 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
4082 enum ipa_splicing_result { NO_GOOD_ACCESS, UNUSED_PARAMS, BY_VAL_ACCESSES,
4083 MODIF_BY_REF_ACCESSES, UNMODIF_BY_REF_ACCESSES };
4085 /* Identify representatives of all accesses to all candidate parameters for
4086 IPA-SRA. Return result based on what representatives have been found. */
4088 static enum ipa_splicing_result
4089 splice_all_param_accesses (vec<access_p> &representatives)
4091 enum ipa_splicing_result result = NO_GOOD_ACCESS;
4093 struct access *repr;
4095 representatives.create (func_param_count);
4097 for (parm = DECL_ARGUMENTS (current_function_decl);
4099 parm = DECL_CHAIN (parm))
4101 if (is_unused_scalar_param (parm))
4103 representatives.quick_push (&no_accesses_representant);
4104 if (result == NO_GOOD_ACCESS)
4105 result = UNUSED_PARAMS;
4107 else if (POINTER_TYPE_P (TREE_TYPE (parm))
4108 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm)))
4109 && bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
4111 repr = unmodified_by_ref_scalar_representative (parm);
4112 representatives.quick_push (repr);
4114 result = UNMODIF_BY_REF_ACCESSES;
4116 else if (bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
4118 bool ro_grp = false;
4119 repr = splice_param_accesses (parm, &ro_grp);
4120 representatives.quick_push (repr);
4122 if (repr && !no_accesses_p (repr))
4124 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4127 result = UNMODIF_BY_REF_ACCESSES;
4128 else if (result < MODIF_BY_REF_ACCESSES)
4129 result = MODIF_BY_REF_ACCESSES;
4131 else if (result < BY_VAL_ACCESSES)
4132 result = BY_VAL_ACCESSES;
4134 else if (no_accesses_p (repr) && (result == NO_GOOD_ACCESS))
4135 result = UNUSED_PARAMS;
4138 representatives.quick_push (NULL);
4141 if (result == NO_GOOD_ACCESS)
4143 representatives.release ();
4144 return NO_GOOD_ACCESS;
4150 /* Return the index of BASE in PARMS. Abort if it is not found. */
4153 get_param_index (tree base, vec<tree> parms)
4157 len = parms.length ();
4158 for (i = 0; i < len; i++)
4159 if (parms[i] == base)
4164 /* Convert the decisions made at the representative level into compact
4165 parameter adjustments. REPRESENTATIVES are pointers to first
4166 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
4167 final number of adjustments. */
4169 static ipa_parm_adjustment_vec
4170 turn_representatives_into_adjustments (vec<access_p> representatives,
4171 int adjustments_count)
4174 ipa_parm_adjustment_vec adjustments;
4178 gcc_assert (adjustments_count > 0);
4179 parms = ipa_get_vector_of_formal_parms (current_function_decl);
4180 adjustments.create (adjustments_count);
4181 parm = DECL_ARGUMENTS (current_function_decl);
4182 for (i = 0; i < func_param_count; i++, parm = DECL_CHAIN (parm))
4184 struct access *repr = representatives[i];
4186 if (!repr || no_accesses_p (repr))
4188 struct ipa_parm_adjustment adj;
4190 memset (&adj, 0, sizeof (adj));
4191 adj.base_index = get_param_index (parm, parms);
4196 adj.remove_param = 1;
4197 adjustments.quick_push (adj);
4201 struct ipa_parm_adjustment adj;
4202 int index = get_param_index (parm, parms);
4204 for (; repr; repr = repr->next_grp)
4206 memset (&adj, 0, sizeof (adj));
4207 gcc_assert (repr->base == parm);
4208 adj.base_index = index;
4209 adj.base = repr->base;
4210 adj.type = repr->type;
4211 adj.alias_ptr_type = reference_alias_ptr_type (repr->expr);
4212 adj.offset = repr->offset;
4213 adj.by_ref = (POINTER_TYPE_P (TREE_TYPE (repr->base))
4214 && (repr->grp_maybe_modified
4215 || repr->grp_not_necessarilly_dereferenced));
4216 adjustments.quick_push (adj);
4224 /* Analyze the collected accesses and produce a plan what to do with the
4225 parameters in the form of adjustments, NULL meaning nothing. */
4227 static ipa_parm_adjustment_vec
4228 analyze_all_param_acesses (void)
4230 enum ipa_splicing_result repr_state;
4231 bool proceed = false;
4232 int i, adjustments_count = 0;
4233 vec<access_p> representatives;
4234 ipa_parm_adjustment_vec adjustments;
4236 repr_state = splice_all_param_accesses (representatives);
4237 if (repr_state == NO_GOOD_ACCESS)
4238 return ipa_parm_adjustment_vec();
4240 /* If there are any parameters passed by reference which are not modified
4241 directly, we need to check whether they can be modified indirectly. */
4242 if (repr_state == UNMODIF_BY_REF_ACCESSES)
4244 analyze_caller_dereference_legality (representatives);
4245 analyze_modified_params (representatives);
4248 for (i = 0; i < func_param_count; i++)
4250 struct access *repr = representatives[i];
4252 if (repr && !no_accesses_p (repr))
4254 if (repr->grp_scalar_ptr)
4256 adjustments_count++;
4257 if (repr->grp_not_necessarilly_dereferenced
4258 || repr->grp_maybe_modified)
4259 representatives[i] = NULL;
4263 sra_stats.scalar_by_ref_to_by_val++;
4268 int new_components = decide_one_param_reduction (repr);
4270 if (new_components == 0)
4272 representatives[i] = NULL;
4273 adjustments_count++;
4277 adjustments_count += new_components;
4278 sra_stats.aggregate_params_reduced++;
4279 sra_stats.param_reductions_created += new_components;
4286 if (no_accesses_p (repr))
4289 sra_stats.deleted_unused_parameters++;
4291 adjustments_count++;
4295 if (!proceed && dump_file)
4296 fprintf (dump_file, "NOT proceeding to change params.\n");
4299 adjustments = turn_representatives_into_adjustments (representatives,
4302 adjustments = ipa_parm_adjustment_vec();
4304 representatives.release ();
4308 /* If a parameter replacement identified by ADJ does not yet exist in the form
4309 of declaration, create it and record it, otherwise return the previously
4313 get_replaced_param_substitute (struct ipa_parm_adjustment *adj)
4316 if (!adj->new_ssa_base)
4318 char *pretty_name = make_fancy_name (adj->base);
4320 repl = create_tmp_reg (TREE_TYPE (adj->base), "ISR");
4321 DECL_NAME (repl) = get_identifier (pretty_name);
4322 obstack_free (&name_obstack, pretty_name);
4324 adj->new_ssa_base = repl;
4327 repl = adj->new_ssa_base;
4331 /* Find the first adjustment for a particular parameter BASE in a vector of
4332 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
4335 static struct ipa_parm_adjustment *
4336 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments, tree base)
4340 len = adjustments.length ();
4341 for (i = 0; i < len; i++)
4343 struct ipa_parm_adjustment *adj;
4345 adj = &adjustments[i];
4346 if (!adj->copy_param && adj->base == base)
4353 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
4354 removed because its value is not used, replace the SSA_NAME with a one
4355 relating to a created VAR_DECL together all of its uses and return true.
4356 ADJUSTMENTS is a pointer to an adjustments vector. */
4359 replace_removed_params_ssa_names (gimple stmt,
4360 ipa_parm_adjustment_vec adjustments)
4362 struct ipa_parm_adjustment *adj;
4363 tree lhs, decl, repl, name;
4365 if (gimple_code (stmt) == GIMPLE_PHI)
4366 lhs = gimple_phi_result (stmt);
4367 else if (is_gimple_assign (stmt))
4368 lhs = gimple_assign_lhs (stmt);
4369 else if (is_gimple_call (stmt))
4370 lhs = gimple_call_lhs (stmt);
4374 if (TREE_CODE (lhs) != SSA_NAME)
4377 decl = SSA_NAME_VAR (lhs);
4378 if (decl == NULL_TREE
4379 || TREE_CODE (decl) != PARM_DECL)
4382 adj = get_adjustment_for_base (adjustments, decl);
4386 repl = get_replaced_param_substitute (adj);
4387 name = make_ssa_name (repl, stmt);
4391 fprintf (dump_file, "replacing an SSA name of a removed param ");
4392 print_generic_expr (dump_file, lhs, 0);
4393 fprintf (dump_file, " with ");
4394 print_generic_expr (dump_file, name, 0);
4395 fprintf (dump_file, "\n");
4398 if (is_gimple_assign (stmt))
4399 gimple_assign_set_lhs (stmt, name);
4400 else if (is_gimple_call (stmt))
4401 gimple_call_set_lhs (stmt, name);
4403 gimple_phi_set_result (stmt, name);
4405 replace_uses_by (lhs, name);
4406 release_ssa_name (lhs);
4410 /* If the expression *EXPR should be replaced by a reduction of a parameter, do
4411 so. ADJUSTMENTS is a pointer to a vector of adjustments. CONVERT
4412 specifies whether the function should care about type incompatibility the
4413 current and new expressions. If it is false, the function will leave
4414 incompatibility issues to the caller. Return true iff the expression
4418 sra_ipa_modify_expr (tree *expr, bool convert,
4419 ipa_parm_adjustment_vec adjustments)
4422 struct ipa_parm_adjustment *adj, *cand = NULL;
4423 HOST_WIDE_INT offset, size, max_size;
4426 len = adjustments.length ();
4428 if (TREE_CODE (*expr) == BIT_FIELD_REF
4429 || TREE_CODE (*expr) == IMAGPART_EXPR
4430 || TREE_CODE (*expr) == REALPART_EXPR)
4432 expr = &TREE_OPERAND (*expr, 0);
4436 base = get_ref_base_and_extent (*expr, &offset, &size, &max_size);
4437 if (!base || size == -1 || max_size == -1)
4440 if (TREE_CODE (base) == MEM_REF)
4442 offset += mem_ref_offset (base).low * BITS_PER_UNIT;
4443 base = TREE_OPERAND (base, 0);
4446 base = get_ssa_base_param (base);
4447 if (!base || TREE_CODE (base) != PARM_DECL)
4450 for (i = 0; i < len; i++)
4452 adj = &adjustments[i];
4454 if (adj->base == base &&
4455 (adj->offset == offset || adj->remove_param))
4461 if (!cand || cand->copy_param || cand->remove_param)
4465 src = build_simple_mem_ref (cand->reduction);
4467 src = cand->reduction;
4469 if (dump_file && (dump_flags & TDF_DETAILS))
4471 fprintf (dump_file, "About to replace expr ");
4472 print_generic_expr (dump_file, *expr, 0);
4473 fprintf (dump_file, " with ");
4474 print_generic_expr (dump_file, src, 0);
4475 fprintf (dump_file, "\n");
4478 if (convert && !useless_type_conversion_p (TREE_TYPE (*expr), cand->type))
4480 tree vce = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (*expr), src);
4488 /* If the statement pointed to by STMT_PTR contains any expressions that need
4489 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4490 potential type incompatibilities (GSI is used to accommodate conversion
4491 statements and must point to the statement). Return true iff the statement
4495 sra_ipa_modify_assign (gimple *stmt_ptr, gimple_stmt_iterator *gsi,
4496 ipa_parm_adjustment_vec adjustments)
4498 gimple stmt = *stmt_ptr;
4499 tree *lhs_p, *rhs_p;
4502 if (!gimple_assign_single_p (stmt))
4505 rhs_p = gimple_assign_rhs1_ptr (stmt);
4506 lhs_p = gimple_assign_lhs_ptr (stmt);
4508 any = sra_ipa_modify_expr (rhs_p, false, adjustments);
4509 any |= sra_ipa_modify_expr (lhs_p, false, adjustments);
4512 tree new_rhs = NULL_TREE;
4514 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p), TREE_TYPE (*rhs_p)))
4516 if (TREE_CODE (*rhs_p) == CONSTRUCTOR)
4518 /* V_C_Es of constructors can cause trouble (PR 42714). */
4519 if (is_gimple_reg_type (TREE_TYPE (*lhs_p)))
4520 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
4522 *rhs_p = build_constructor (TREE_TYPE (*lhs_p),
4526 new_rhs = fold_build1_loc (gimple_location (stmt),
4527 VIEW_CONVERT_EXPR, TREE_TYPE (*lhs_p),
4530 else if (REFERENCE_CLASS_P (*rhs_p)
4531 && is_gimple_reg_type (TREE_TYPE (*lhs_p))
4532 && !is_gimple_reg (*lhs_p))
4533 /* This can happen when an assignment in between two single field
4534 structures is turned into an assignment in between two pointers to
4535 scalars (PR 42237). */
4540 tree tmp = force_gimple_operand_gsi (gsi, new_rhs, true, NULL_TREE,
4541 true, GSI_SAME_STMT);
4543 gimple_assign_set_rhs_from_tree (gsi, tmp);
4552 /* Traverse the function body and all modifications as described in
4553 ADJUSTMENTS. Return true iff the CFG has been changed. */
4556 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments)
4558 bool cfg_changed = false;
4563 gimple_stmt_iterator gsi;
4565 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4566 replace_removed_params_ssa_names (gsi_stmt (gsi), adjustments);
4568 gsi = gsi_start_bb (bb);
4569 while (!gsi_end_p (gsi))
4571 gimple stmt = gsi_stmt (gsi);
4572 bool modified = false;
4576 switch (gimple_code (stmt))
4579 t = gimple_return_retval_ptr (stmt);
4580 if (*t != NULL_TREE)
4581 modified |= sra_ipa_modify_expr (t, true, adjustments);
4585 modified |= sra_ipa_modify_assign (&stmt, &gsi, adjustments);
4586 modified |= replace_removed_params_ssa_names (stmt, adjustments);
4590 /* Operands must be processed before the lhs. */
4591 for (i = 0; i < gimple_call_num_args (stmt); i++)
4593 t = gimple_call_arg_ptr (stmt, i);
4594 modified |= sra_ipa_modify_expr (t, true, adjustments);
4597 if (gimple_call_lhs (stmt))
4599 t = gimple_call_lhs_ptr (stmt);
4600 modified |= sra_ipa_modify_expr (t, false, adjustments);
4601 modified |= replace_removed_params_ssa_names (stmt,
4607 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
4609 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
4610 modified |= sra_ipa_modify_expr (t, true, adjustments);
4612 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
4614 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
4615 modified |= sra_ipa_modify_expr (t, false, adjustments);
4626 if (maybe_clean_eh_stmt (stmt)
4627 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
4637 /* Call gimple_debug_bind_reset_value on all debug statements describing
4638 gimple register parameters that are being removed or replaced. */
4641 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments)
4644 gimple_stmt_iterator *gsip = NULL, gsi;
4646 if (MAY_HAVE_DEBUG_STMTS && single_succ_p (ENTRY_BLOCK_PTR))
4648 gsi = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR));
4651 len = adjustments.length ();
4652 for (i = 0; i < len; i++)
4654 struct ipa_parm_adjustment *adj;
4655 imm_use_iterator ui;
4656 gimple stmt, def_temp;
4657 tree name, vexpr, copy = NULL_TREE;
4658 use_operand_p use_p;
4660 adj = &adjustments[i];
4661 if (adj->copy_param || !is_gimple_reg (adj->base))
4663 name = ssa_default_def (cfun, adj->base);
4666 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
4668 /* All other users must have been removed by
4669 ipa_sra_modify_function_body. */
4670 gcc_assert (is_gimple_debug (stmt));
4671 if (vexpr == NULL && gsip != NULL)
4673 gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
4674 vexpr = make_node (DEBUG_EXPR_DECL);
4675 def_temp = gimple_build_debug_source_bind (vexpr, adj->base,
4677 DECL_ARTIFICIAL (vexpr) = 1;
4678 TREE_TYPE (vexpr) = TREE_TYPE (name);
4679 DECL_MODE (vexpr) = DECL_MODE (adj->base);
4680 gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
4684 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
4685 SET_USE (use_p, vexpr);
4688 gimple_debug_bind_reset_value (stmt);
4691 /* Create a VAR_DECL for debug info purposes. */
4692 if (!DECL_IGNORED_P (adj->base))
4694 copy = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
4695 VAR_DECL, DECL_NAME (adj->base),
4696 TREE_TYPE (adj->base));
4697 if (DECL_PT_UID_SET_P (adj->base))
4698 SET_DECL_PT_UID (copy, DECL_PT_UID (adj->base));
4699 TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (adj->base);
4700 TREE_READONLY (copy) = TREE_READONLY (adj->base);
4701 TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (adj->base);
4702 DECL_GIMPLE_REG_P (copy) = DECL_GIMPLE_REG_P (adj->base);
4703 DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (adj->base);
4704 DECL_IGNORED_P (copy) = DECL_IGNORED_P (adj->base);
4705 DECL_ABSTRACT_ORIGIN (copy) = DECL_ORIGIN (adj->base);
4706 DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
4707 SET_DECL_RTL (copy, 0);
4708 TREE_USED (copy) = 1;
4709 DECL_CONTEXT (copy) = current_function_decl;
4710 add_local_decl (cfun, copy);
4712 BLOCK_VARS (DECL_INITIAL (current_function_decl));
4713 BLOCK_VARS (DECL_INITIAL (current_function_decl)) = copy;
4715 if (gsip != NULL && copy && target_for_debug_bind (adj->base))
4717 gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
4719 def_temp = gimple_build_debug_bind (copy, vexpr, NULL);
4721 def_temp = gimple_build_debug_source_bind (copy, adj->base,
4723 gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
4728 /* Return false iff all callers have at least as many actual arguments as there
4729 are formal parameters in the current function. */
4732 not_all_callers_have_enough_arguments_p (struct cgraph_node *node,
4733 void *data ATTRIBUTE_UNUSED)
4735 struct cgraph_edge *cs;
4736 for (cs = node->callers; cs; cs = cs->next_caller)
4737 if (!callsite_has_enough_arguments_p (cs->call_stmt))
4743 /* Convert all callers of NODE. */
4746 convert_callers_for_node (struct cgraph_node *node,
4749 ipa_parm_adjustment_vec *adjustments = (ipa_parm_adjustment_vec *) data;
4750 bitmap recomputed_callers = BITMAP_ALLOC (NULL);
4751 struct cgraph_edge *cs;
4753 for (cs = node->callers; cs; cs = cs->next_caller)
4755 push_cfun (DECL_STRUCT_FUNCTION (cs->caller->symbol.decl));
4758 fprintf (dump_file, "Adjusting call (%i -> %i) %s -> %s\n",
4759 cs->caller->uid, cs->callee->uid,
4760 xstrdup (cgraph_node_name (cs->caller)),
4761 xstrdup (cgraph_node_name (cs->callee)));
4763 ipa_modify_call_arguments (cs, cs->call_stmt, *adjustments);
4768 for (cs = node->callers; cs; cs = cs->next_caller)
4769 if (bitmap_set_bit (recomputed_callers, cs->caller->uid)
4770 && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (cs->caller->symbol.decl)))
4771 compute_inline_parameters (cs->caller, true);
4772 BITMAP_FREE (recomputed_callers);
4777 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4780 convert_callers (struct cgraph_node *node, tree old_decl,
4781 ipa_parm_adjustment_vec adjustments)
4783 basic_block this_block;
4785 cgraph_for_node_and_aliases (node, convert_callers_for_node,
4786 &adjustments, false);
4788 if (!encountered_recursive_call)
4791 FOR_EACH_BB (this_block)
4793 gimple_stmt_iterator gsi;
4795 for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
4797 gimple stmt = gsi_stmt (gsi);
4799 if (gimple_code (stmt) != GIMPLE_CALL)
4801 call_fndecl = gimple_call_fndecl (stmt);
4802 if (call_fndecl == old_decl)
4805 fprintf (dump_file, "Adjusting recursive call");
4806 gimple_call_set_fndecl (stmt, node->symbol.decl);
4807 ipa_modify_call_arguments (NULL, stmt, adjustments);
4815 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4816 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4819 modify_function (struct cgraph_node *node, ipa_parm_adjustment_vec adjustments)
4821 struct cgraph_node *new_node;
4823 vec<cgraph_edge_p> redirect_callers = collect_callers_of_node (node);
4825 rebuild_cgraph_edges ();
4826 free_dominance_info (CDI_DOMINATORS);
4829 new_node = cgraph_function_versioning (node, redirect_callers,
4831 NULL, false, NULL, NULL, "isra");
4832 redirect_callers.release ();
4834 push_cfun (DECL_STRUCT_FUNCTION (new_node->symbol.decl));
4835 ipa_modify_formal_parameters (current_function_decl, adjustments, "ISRA");
4836 cfg_changed = ipa_sra_modify_function_body (adjustments);
4837 sra_ipa_reset_debug_stmts (adjustments);
4838 convert_callers (new_node, node->symbol.decl, adjustments);
4839 cgraph_make_node_local (new_node);
4843 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4844 attributes, return true otherwise. NODE is the cgraph node of the current
4848 ipa_sra_preliminary_function_checks (struct cgraph_node *node)
4850 if (!cgraph_node_can_be_local_p (node))
4853 fprintf (dump_file, "Function not local to this compilation unit.\n");
4857 if (!node->local.can_change_signature)
4860 fprintf (dump_file, "Function can not change signature.\n");
4864 if (!tree_versionable_function_p (node->symbol.decl))
4867 fprintf (dump_file, "Function is not versionable.\n");
4871 if (DECL_VIRTUAL_P (current_function_decl))
4874 fprintf (dump_file, "Function is a virtual method.\n");
4878 if ((DECL_COMDAT (node->symbol.decl) || DECL_EXTERNAL (node->symbol.decl))
4879 && inline_summary(node)->size >= MAX_INLINE_INSNS_AUTO)
4882 fprintf (dump_file, "Function too big to be made truly local.\n");
4890 "Function has no callers in this compilation unit.\n");
4897 fprintf (dump_file, "Function uses stdarg. \n");
4901 if (TYPE_ATTRIBUTES (TREE_TYPE (node->symbol.decl)))
4907 /* Perform early interprocedural SRA. */
4910 ipa_early_sra (void)
4912 struct cgraph_node *node = cgraph_get_node (current_function_decl);
4913 ipa_parm_adjustment_vec adjustments;
4916 if (!ipa_sra_preliminary_function_checks (node))
4920 sra_mode = SRA_MODE_EARLY_IPA;
4922 if (!find_param_candidates ())
4925 fprintf (dump_file, "Function has no IPA-SRA candidates.\n");
4929 if (cgraph_for_node_and_aliases (node, not_all_callers_have_enough_arguments_p,
4933 fprintf (dump_file, "There are callers with insufficient number of "
4938 bb_dereferences = XCNEWVEC (HOST_WIDE_INT,
4940 * last_basic_block_for_function (cfun));
4941 final_bbs = BITMAP_ALLOC (NULL);
4944 if (encountered_apply_args)
4947 fprintf (dump_file, "Function calls __builtin_apply_args().\n");
4951 if (encountered_unchangable_recursive_call)
4954 fprintf (dump_file, "Function calls itself with insufficient "
4955 "number of arguments.\n");
4959 adjustments = analyze_all_param_acesses ();
4960 if (!adjustments.exists ())
4963 ipa_dump_param_adjustments (dump_file, adjustments, current_function_decl);
4965 if (modify_function (node, adjustments))
4966 ret = TODO_update_ssa | TODO_cleanup_cfg;
4968 ret = TODO_update_ssa;
4969 adjustments.release ();
4971 statistics_counter_event (cfun, "Unused parameters deleted",
4972 sra_stats.deleted_unused_parameters);
4973 statistics_counter_event (cfun, "Scalar parameters converted to by-value",
4974 sra_stats.scalar_by_ref_to_by_val);
4975 statistics_counter_event (cfun, "Aggregate parameters broken up",
4976 sra_stats.aggregate_params_reduced);
4977 statistics_counter_event (cfun, "Aggregate parameter components created",
4978 sra_stats.param_reductions_created);
4981 BITMAP_FREE (final_bbs);
4982 free (bb_dereferences);
4984 sra_deinitialize ();
4988 /* Return if early ipa sra shall be performed. */
4990 ipa_early_sra_gate (void)
4992 return flag_ipa_sra && dbg_cnt (eipa_sra);
4995 struct gimple_opt_pass pass_early_ipa_sra =
4999 "eipa_sra", /* name */
5000 OPTGROUP_NONE, /* optinfo_flags */
5001 ipa_early_sra_gate, /* gate */
5002 ipa_early_sra, /* execute */
5005 0, /* static_pass_number */
5006 TV_IPA_SRA, /* tv_id */
5007 0, /* properties_required */
5008 0, /* properties_provided */
5009 0, /* properties_destroyed */
5010 0, /* todo_flags_start */
5011 TODO_dump_symtab /* todo_flags_finish */