1 /* Scalar Replacement of Aggregates (SRA) converts some structure
2 references into scalar references, exposing them to the scalar
4 Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
5 Contributed by Martin Jambor <mjambor@suse.cz>
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* This file implements Scalar Reduction of Aggregates (SRA). SRA is run
24 twice, once in the early stages of compilation (early SRA) and once in the
25 late stages (late SRA). The aim of both is to turn references to scalar
26 parts of aggregates into uses of independent scalar variables.
28 The two passes are nearly identical, the only difference is that early SRA
29 does not scalarize unions which are used as the result in a GIMPLE_RETURN
30 statement because together with inlining this can lead to weird type
33 Both passes operate in four stages:
35 1. The declarations that have properties which make them candidates for
36 scalarization are identified in function find_var_candidates(). The
37 candidates are stored in candidate_bitmap.
39 2. The function body is scanned. In the process, declarations which are
40 used in a manner that prevent their scalarization are removed from the
41 candidate bitmap. More importantly, for every access into an aggregate,
42 an access structure (struct access) is created by create_access() and
43 stored in a vector associated with the aggregate. Among other
44 information, the aggregate declaration, the offset and size of the access
45 and its type are stored in the structure.
47 On a related note, assign_link structures are created for every assign
48 statement between candidate aggregates and attached to the related
51 3. The vectors of accesses are analyzed. They are first sorted according to
52 their offset and size and then scanned for partially overlapping accesses
53 (i.e. those which overlap but one is not entirely within another). Such
54 an access disqualifies the whole aggregate from being scalarized.
56 If there is no such inhibiting overlap, a representative access structure
57 is chosen for every unique combination of offset and size. Afterwards,
58 the pass builds a set of trees from these structures, in which children
59 of an access are within their parent (in terms of offset and size).
61 Then accesses are propagated whenever possible (i.e. in cases when it
62 does not create a partially overlapping access) across assign_links from
63 the right hand side to the left hand side.
65 Then the set of trees for each declaration is traversed again and those
66 accesses which should be replaced by a scalar are identified.
68 4. The function is traversed again, and for every reference into an
69 aggregate that has some component which is about to be scalarized,
70 statements are amended and new statements are created as necessary.
71 Finally, if a parameter got scalarized, the scalar replacements are
72 initialized with values from respective parameter aggregates. */
76 #include "coretypes.h"
77 #include "alloc-pool.h"
83 #include "tree-flow.h"
85 #include "tree-pretty-print.h"
86 #include "statistics.h"
87 #include "tree-dump.h"
93 #include "tree-inline.h"
94 #include "gimple-pretty-print.h"
96 /* Enumeration of all aggregate reductions we can do. */
97 enum sra_mode { SRA_MODE_EARLY_IPA, /* early call regularization */
98 SRA_MODE_EARLY_INTRA, /* early intraprocedural SRA */
99 SRA_MODE_INTRA }; /* late intraprocedural SRA */
101 /* Global variable describing which aggregate reduction we are performing at
103 static enum sra_mode sra_mode;
107 /* ACCESS represents each access to an aggregate variable (as a whole or a
108 part). It can also represent a group of accesses that refer to exactly the
109 same fragment of an aggregate (i.e. those that have exactly the same offset
110 and size). Such representatives for a single aggregate, once determined,
111 are linked in a linked list and have the group fields set.
113 Moreover, when doing intraprocedural SRA, a tree is built from those
114 representatives (by the means of first_child and next_sibling pointers), in
115 which all items in a subtree are "within" the root, i.e. their offset is
116 greater or equal to offset of the root and offset+size is smaller or equal
117 to offset+size of the root. Children of an access are sorted by offset.
119 Note that accesses to parts of vector and complex number types always
120 represented by an access to the whole complex number or a vector. It is a
121 duty of the modifying functions to replace them appropriately. */
125 /* Values returned by `get_ref_base_and_extent' for each component reference
126 If EXPR isn't a component reference just set `BASE = EXPR', `OFFSET = 0',
127 `SIZE = TREE_SIZE (TREE_TYPE (expr))'. */
128 HOST_WIDE_INT offset;
132 /* Expression. It is context dependent so do not use it to create new
133 expressions to access the original aggregate. See PR 42154 for a
139 /* The statement this access belongs to. */
142 /* Next group representative for this aggregate. */
143 struct access *next_grp;
145 /* Pointer to the group representative. Pointer to itself if the struct is
146 the representative. */
147 struct access *group_representative;
149 /* If this access has any children (in terms of the definition above), this
150 points to the first one. */
151 struct access *first_child;
153 /* In intraprocedural SRA, pointer to the next sibling in the access tree as
154 described above. In IPA-SRA this is a pointer to the next access
155 belonging to the same group (having the same representative). */
156 struct access *next_sibling;
158 /* Pointers to the first and last element in the linked list of assign
160 struct assign_link *first_link, *last_link;
162 /* Pointer to the next access in the work queue. */
163 struct access *next_queued;
165 /* Replacement variable for this access "region." Never to be accessed
166 directly, always only by the means of get_access_replacement() and only
167 when grp_to_be_replaced flag is set. */
168 tree replacement_decl;
170 /* Is this particular access write access? */
173 /* Is this access an artificial one created to scalarize some record
175 unsigned total_scalarization : 1;
177 /* Is this access currently in the work queue? */
178 unsigned grp_queued : 1;
180 /* Does this group contain a write access? This flag is propagated down the
182 unsigned grp_write : 1;
184 /* Does this group contain a read access? This flag is propagated down the
186 unsigned grp_read : 1;
188 /* Does this group contain a read access that comes from an assignment
189 statement? This flag is propagated down the access tree. */
190 unsigned grp_assignment_read : 1;
192 /* Does this group contain a write access that comes from an assignment
193 statement? This flag is propagated down the access tree. */
194 unsigned grp_assignment_write : 1;
196 /* Other passes of the analysis use this bit to make function
197 analyze_access_subtree create scalar replacements for this group if
199 unsigned grp_hint : 1;
201 /* Is the subtree rooted in this access fully covered by scalar
203 unsigned grp_covered : 1;
205 /* If set to true, this access and all below it in an access tree must not be
207 unsigned grp_unscalarizable_region : 1;
209 /* Whether data have been written to parts of the aggregate covered by this
210 access which is not to be scalarized. This flag is propagated up in the
212 unsigned grp_unscalarized_data : 1;
214 /* Does this access and/or group contain a write access through a
216 unsigned grp_partial_lhs : 1;
218 /* Set when a scalar replacement should be created for this variable. We do
219 the decision and creation at different places because create_tmp_var
220 cannot be called from within FOR_EACH_REFERENCED_VAR. */
221 unsigned grp_to_be_replaced : 1;
223 /* Should TREE_NO_WARNING of a replacement be set? */
224 unsigned grp_no_warning : 1;
226 /* Is it possible that the group refers to data which might be (directly or
227 otherwise) modified? */
228 unsigned grp_maybe_modified : 1;
230 /* Set when this is a representative of a pointer to scalar (i.e. by
231 reference) parameter which we consider for turning into a plain scalar
232 (i.e. a by value parameter). */
233 unsigned grp_scalar_ptr : 1;
235 /* Set when we discover that this pointer is not safe to dereference in the
237 unsigned grp_not_necessarilly_dereferenced : 1;
240 typedef struct access *access_p;
242 DEF_VEC_P (access_p);
243 DEF_VEC_ALLOC_P (access_p, heap);
245 /* Alloc pool for allocating access structures. */
246 static alloc_pool access_pool;
248 /* A structure linking lhs and rhs accesses from an aggregate assignment. They
249 are used to propagate subaccesses from rhs to lhs as long as they don't
250 conflict with what is already there. */
253 struct access *lacc, *racc;
254 struct assign_link *next;
257 /* Alloc pool for allocating assign link structures. */
258 static alloc_pool link_pool;
260 /* Base (tree) -> Vector (VEC(access_p,heap) *) map. */
261 static struct pointer_map_t *base_access_vec;
263 /* Bitmap of candidates. */
264 static bitmap candidate_bitmap;
266 /* Bitmap of candidates which we should try to entirely scalarize away and
267 those which cannot be (because they are and need be used as a whole). */
268 static bitmap should_scalarize_away_bitmap, cannot_scalarize_away_bitmap;
270 /* Obstack for creation of fancy names. */
271 static struct obstack name_obstack;
273 /* Head of a linked list of accesses that need to have its subaccesses
274 propagated to their assignment counterparts. */
275 static struct access *work_queue_head;
277 /* Number of parameters of the analyzed function when doing early ipa SRA. */
278 static int func_param_count;
280 /* scan_function sets the following to true if it encounters a call to
281 __builtin_apply_args. */
282 static bool encountered_apply_args;
284 /* Set by scan_function when it finds a recursive call. */
285 static bool encountered_recursive_call;
287 /* Set by scan_function when it finds a recursive call with less actual
288 arguments than formal parameters.. */
289 static bool encountered_unchangable_recursive_call;
291 /* This is a table in which for each basic block and parameter there is a
292 distance (offset + size) in that parameter which is dereferenced and
293 accessed in that BB. */
294 static HOST_WIDE_INT *bb_dereferences;
295 /* Bitmap of BBs that can cause the function to "stop" progressing by
296 returning, throwing externally, looping infinitely or calling a function
297 which might abort etc.. */
298 static bitmap final_bbs;
300 /* Representative of no accesses at all. */
301 static struct access no_accesses_representant;
303 /* Predicate to test the special value. */
306 no_accesses_p (struct access *access)
308 return access == &no_accesses_representant;
311 /* Dump contents of ACCESS to file F in a human friendly way. If GRP is true,
312 representative fields are dumped, otherwise those which only describe the
313 individual access are. */
317 /* Number of processed aggregates is readily available in
318 analyze_all_variable_accesses and so is not stored here. */
320 /* Number of created scalar replacements. */
323 /* Number of times sra_modify_expr or sra_modify_assign themselves changed an
327 /* Number of statements created by generate_subtree_copies. */
330 /* Number of statements created by load_assign_lhs_subreplacements. */
333 /* Number of times sra_modify_assign has deleted a statement. */
336 /* Number of times sra_modify_assign has to deal with subaccesses of LHS and
337 RHS reparately due to type conversions or nonexistent matching
339 int separate_lhs_rhs_handling;
341 /* Number of parameters that were removed because they were unused. */
342 int deleted_unused_parameters;
344 /* Number of scalars passed as parameters by reference that have been
345 converted to be passed by value. */
346 int scalar_by_ref_to_by_val;
348 /* Number of aggregate parameters that were replaced by one or more of their
350 int aggregate_params_reduced;
352 /* Numbber of components created when splitting aggregate parameters. */
353 int param_reductions_created;
357 dump_access (FILE *f, struct access *access, bool grp)
359 fprintf (f, "access { ");
360 fprintf (f, "base = (%d)'", DECL_UID (access->base));
361 print_generic_expr (f, access->base, 0);
362 fprintf (f, "', offset = " HOST_WIDE_INT_PRINT_DEC, access->offset);
363 fprintf (f, ", size = " HOST_WIDE_INT_PRINT_DEC, access->size);
364 fprintf (f, ", expr = ");
365 print_generic_expr (f, access->expr, 0);
366 fprintf (f, ", type = ");
367 print_generic_expr (f, access->type, 0);
369 fprintf (f, ", grp_write = %d, total_scalarization = %d, "
370 "grp_read = %d, grp_hint = %d, grp_assignment_read = %d,"
371 "grp_assignment_write = %d, grp_covered = %d, "
372 "grp_unscalarizable_region = %d, grp_unscalarized_data = %d, "
373 "grp_partial_lhs = %d, grp_to_be_replaced = %d, "
374 "grp_maybe_modified = %d, "
375 "grp_not_necessarilly_dereferenced = %d\n",
376 access->grp_write, access->total_scalarization,
377 access->grp_read, access->grp_hint, access->grp_assignment_read,
378 access->grp_assignment_write, access->grp_covered,
379 access->grp_unscalarizable_region, access->grp_unscalarized_data,
380 access->grp_partial_lhs, access->grp_to_be_replaced,
381 access->grp_maybe_modified,
382 access->grp_not_necessarilly_dereferenced);
384 fprintf (f, ", write = %d, total_scalarization = %d, "
385 "grp_partial_lhs = %d\n",
386 access->write, access->total_scalarization,
387 access->grp_partial_lhs);
390 /* Dump a subtree rooted in ACCESS to file F, indent by LEVEL. */
393 dump_access_tree_1 (FILE *f, struct access *access, int level)
399 for (i = 0; i < level; i++)
400 fputs ("* ", dump_file);
402 dump_access (f, access, true);
404 if (access->first_child)
405 dump_access_tree_1 (f, access->first_child, level + 1);
407 access = access->next_sibling;
412 /* Dump all access trees for a variable, given the pointer to the first root in
416 dump_access_tree (FILE *f, struct access *access)
418 for (; access; access = access->next_grp)
419 dump_access_tree_1 (f, access, 0);
422 /* Return true iff ACC is non-NULL and has subaccesses. */
425 access_has_children_p (struct access *acc)
427 return acc && acc->first_child;
430 /* Return a vector of pointers to accesses for the variable given in BASE or
431 NULL if there is none. */
433 static VEC (access_p, heap) *
434 get_base_access_vector (tree base)
438 slot = pointer_map_contains (base_access_vec, base);
442 return *(VEC (access_p, heap) **) slot;
445 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
446 in ACCESS. Return NULL if it cannot be found. */
448 static struct access *
449 find_access_in_subtree (struct access *access, HOST_WIDE_INT offset,
452 while (access && (access->offset != offset || access->size != size))
454 struct access *child = access->first_child;
456 while (child && (child->offset + child->size <= offset))
457 child = child->next_sibling;
464 /* Return the first group representative for DECL or NULL if none exists. */
466 static struct access *
467 get_first_repr_for_decl (tree base)
469 VEC (access_p, heap) *access_vec;
471 access_vec = get_base_access_vector (base);
475 return VEC_index (access_p, access_vec, 0);
478 /* Find an access representative for the variable BASE and given OFFSET and
479 SIZE. Requires that access trees have already been built. Return NULL if
480 it cannot be found. */
482 static struct access *
483 get_var_base_offset_size_access (tree base, HOST_WIDE_INT offset,
486 struct access *access;
488 access = get_first_repr_for_decl (base);
489 while (access && (access->offset + access->size <= offset))
490 access = access->next_grp;
494 return find_access_in_subtree (access, offset, size);
497 /* Add LINK to the linked list of assign links of RACC. */
499 add_link_to_rhs (struct access *racc, struct assign_link *link)
501 gcc_assert (link->racc == racc);
503 if (!racc->first_link)
505 gcc_assert (!racc->last_link);
506 racc->first_link = link;
509 racc->last_link->next = link;
511 racc->last_link = link;
515 /* Move all link structures in their linked list in OLD_RACC to the linked list
518 relink_to_new_repr (struct access *new_racc, struct access *old_racc)
520 if (!old_racc->first_link)
522 gcc_assert (!old_racc->last_link);
526 if (new_racc->first_link)
528 gcc_assert (!new_racc->last_link->next);
529 gcc_assert (!old_racc->last_link || !old_racc->last_link->next);
531 new_racc->last_link->next = old_racc->first_link;
532 new_racc->last_link = old_racc->last_link;
536 gcc_assert (!new_racc->last_link);
538 new_racc->first_link = old_racc->first_link;
539 new_racc->last_link = old_racc->last_link;
541 old_racc->first_link = old_racc->last_link = NULL;
544 /* Add ACCESS to the work queue (which is actually a stack). */
547 add_access_to_work_queue (struct access *access)
549 if (!access->grp_queued)
551 gcc_assert (!access->next_queued);
552 access->next_queued = work_queue_head;
553 access->grp_queued = 1;
554 work_queue_head = access;
558 /* Pop an access from the work queue, and return it, assuming there is one. */
560 static struct access *
561 pop_access_from_work_queue (void)
563 struct access *access = work_queue_head;
565 work_queue_head = access->next_queued;
566 access->next_queued = NULL;
567 access->grp_queued = 0;
572 /* Allocate necessary structures. */
575 sra_initialize (void)
577 candidate_bitmap = BITMAP_ALLOC (NULL);
578 should_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
579 cannot_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
580 gcc_obstack_init (&name_obstack);
581 access_pool = create_alloc_pool ("SRA accesses", sizeof (struct access), 16);
582 link_pool = create_alloc_pool ("SRA links", sizeof (struct assign_link), 16);
583 base_access_vec = pointer_map_create ();
584 memset (&sra_stats, 0, sizeof (sra_stats));
585 encountered_apply_args = false;
586 encountered_recursive_call = false;
587 encountered_unchangable_recursive_call = false;
590 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
593 delete_base_accesses (const void *key ATTRIBUTE_UNUSED, void **value,
594 void *data ATTRIBUTE_UNUSED)
596 VEC (access_p, heap) *access_vec;
597 access_vec = (VEC (access_p, heap) *) *value;
598 VEC_free (access_p, heap, access_vec);
603 /* Deallocate all general structures. */
606 sra_deinitialize (void)
608 BITMAP_FREE (candidate_bitmap);
609 BITMAP_FREE (should_scalarize_away_bitmap);
610 BITMAP_FREE (cannot_scalarize_away_bitmap);
611 free_alloc_pool (access_pool);
612 free_alloc_pool (link_pool);
613 obstack_free (&name_obstack, NULL);
615 pointer_map_traverse (base_access_vec, delete_base_accesses, NULL);
616 pointer_map_destroy (base_access_vec);
619 /* Remove DECL from candidates for SRA and write REASON to the dump file if
622 disqualify_candidate (tree decl, const char *reason)
624 bitmap_clear_bit (candidate_bitmap, DECL_UID (decl));
626 if (dump_file && (dump_flags & TDF_DETAILS))
628 fprintf (dump_file, "! Disqualifying ");
629 print_generic_expr (dump_file, decl, 0);
630 fprintf (dump_file, " - %s\n", reason);
634 /* Return true iff the type contains a field or an element which does not allow
638 type_internals_preclude_sra_p (tree type)
643 switch (TREE_CODE (type))
647 case QUAL_UNION_TYPE:
648 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
649 if (TREE_CODE (fld) == FIELD_DECL)
651 tree ft = TREE_TYPE (fld);
653 if (TREE_THIS_VOLATILE (fld)
654 || !DECL_FIELD_OFFSET (fld) || !DECL_SIZE (fld)
655 || !host_integerp (DECL_FIELD_OFFSET (fld), 1)
656 || !host_integerp (DECL_SIZE (fld), 1))
659 if (AGGREGATE_TYPE_P (ft)
660 && type_internals_preclude_sra_p (ft))
667 et = TREE_TYPE (type);
669 if (AGGREGATE_TYPE_P (et))
670 return type_internals_preclude_sra_p (et);
679 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
680 base variable if it is. Return T if it is not an SSA_NAME. */
683 get_ssa_base_param (tree t)
685 if (TREE_CODE (t) == SSA_NAME)
687 if (SSA_NAME_IS_DEFAULT_DEF (t))
688 return SSA_NAME_VAR (t);
695 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
696 belongs to, unless the BB has already been marked as a potentially
700 mark_parm_dereference (tree base, HOST_WIDE_INT dist, gimple stmt)
702 basic_block bb = gimple_bb (stmt);
703 int idx, parm_index = 0;
706 if (bitmap_bit_p (final_bbs, bb->index))
709 for (parm = DECL_ARGUMENTS (current_function_decl);
710 parm && parm != base;
711 parm = DECL_CHAIN (parm))
714 gcc_assert (parm_index < func_param_count);
716 idx = bb->index * func_param_count + parm_index;
717 if (bb_dereferences[idx] < dist)
718 bb_dereferences[idx] = dist;
721 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
722 the three fields. Also add it to the vector of accesses corresponding to
723 the base. Finally, return the new access. */
725 static struct access *
726 create_access_1 (tree base, HOST_WIDE_INT offset, HOST_WIDE_INT size)
728 VEC (access_p, heap) *vec;
729 struct access *access;
732 access = (struct access *) pool_alloc (access_pool);
733 memset (access, 0, sizeof (struct access));
735 access->offset = offset;
738 slot = pointer_map_contains (base_access_vec, base);
740 vec = (VEC (access_p, heap) *) *slot;
742 vec = VEC_alloc (access_p, heap, 32);
744 VEC_safe_push (access_p, heap, vec, access);
746 *((struct VEC (access_p,heap) **)
747 pointer_map_insert (base_access_vec, base)) = vec;
752 /* Create and insert access for EXPR. Return created access, or NULL if it is
755 static struct access *
756 create_access (tree expr, gimple stmt, bool write)
758 struct access *access;
759 HOST_WIDE_INT offset, size, max_size;
761 bool ptr, unscalarizable_region = false;
763 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
765 if (sra_mode == SRA_MODE_EARLY_IPA
766 && TREE_CODE (base) == MEM_REF)
768 base = get_ssa_base_param (TREE_OPERAND (base, 0));
776 if (!DECL_P (base) || !bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
779 if (sra_mode == SRA_MODE_EARLY_IPA)
781 if (size < 0 || size != max_size)
783 disqualify_candidate (base, "Encountered a variable sized access.");
786 if (TREE_CODE (expr) == COMPONENT_REF
787 && DECL_BIT_FIELD (TREE_OPERAND (expr, 1)))
789 disqualify_candidate (base, "Encountered a bit-field access.");
792 gcc_checking_assert ((offset % BITS_PER_UNIT) == 0);
795 mark_parm_dereference (base, offset + size, stmt);
799 if (size != max_size)
802 unscalarizable_region = true;
806 disqualify_candidate (base, "Encountered an unconstrained access.");
811 access = create_access_1 (base, offset, size);
813 access->type = TREE_TYPE (expr);
814 access->write = write;
815 access->grp_unscalarizable_region = unscalarizable_region;
822 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
823 register types or (recursively) records with only these two kinds of fields.
824 It also returns false if any of these records contains a bit-field. */
827 type_consists_of_records_p (tree type)
831 if (TREE_CODE (type) != RECORD_TYPE)
834 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
835 if (TREE_CODE (fld) == FIELD_DECL)
837 tree ft = TREE_TYPE (fld);
839 if (DECL_BIT_FIELD (fld))
842 if (!is_gimple_reg_type (ft)
843 && !type_consists_of_records_p (ft))
850 /* Create total_scalarization accesses for all scalar type fields in DECL that
851 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
852 must be the top-most VAR_DECL representing the variable, OFFSET must be the
853 offset of DECL within BASE. REF must be the memory reference expression for
857 completely_scalarize_record (tree base, tree decl, HOST_WIDE_INT offset,
860 tree fld, decl_type = TREE_TYPE (decl);
862 for (fld = TYPE_FIELDS (decl_type); fld; fld = DECL_CHAIN (fld))
863 if (TREE_CODE (fld) == FIELD_DECL)
865 HOST_WIDE_INT pos = offset + int_bit_position (fld);
866 tree ft = TREE_TYPE (fld);
867 tree nref = build3 (COMPONENT_REF, TREE_TYPE (fld), ref, fld,
870 if (is_gimple_reg_type (ft))
872 struct access *access;
875 size = tree_low_cst (DECL_SIZE (fld), 1);
876 access = create_access_1 (base, pos, size);
879 access->total_scalarization = 1;
880 /* Accesses for intraprocedural SRA can have their stmt NULL. */
883 completely_scalarize_record (base, fld, pos, nref);
888 /* Search the given tree for a declaration by skipping handled components and
889 exclude it from the candidates. */
892 disqualify_base_of_expr (tree t, const char *reason)
894 t = get_base_address (t);
895 if (sra_mode == SRA_MODE_EARLY_IPA
896 && TREE_CODE (t) == MEM_REF)
897 t = get_ssa_base_param (TREE_OPERAND (t, 0));
900 disqualify_candidate (t, reason);
903 /* Scan expression EXPR and create access structures for all accesses to
904 candidates for scalarization. Return the created access or NULL if none is
907 static struct access *
908 build_access_from_expr_1 (tree expr, gimple stmt, bool write)
910 struct access *ret = NULL;
913 if (TREE_CODE (expr) == BIT_FIELD_REF
914 || TREE_CODE (expr) == IMAGPART_EXPR
915 || TREE_CODE (expr) == REALPART_EXPR)
917 expr = TREE_OPERAND (expr, 0);
923 /* We need to dive through V_C_Es in order to get the size of its parameter
924 and not the result type. Ada produces such statements. We are also
925 capable of handling the topmost V_C_E but not any of those buried in other
926 handled components. */
927 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
928 expr = TREE_OPERAND (expr, 0);
930 if (contains_view_convert_expr_p (expr))
932 disqualify_base_of_expr (expr, "V_C_E under a different handled "
937 switch (TREE_CODE (expr))
940 if (TREE_CODE (TREE_OPERAND (expr, 0)) != ADDR_EXPR
941 && sra_mode != SRA_MODE_EARLY_IPA)
949 case ARRAY_RANGE_REF:
950 ret = create_access (expr, stmt, write);
957 if (write && partial_ref && ret)
958 ret->grp_partial_lhs = 1;
963 /* Scan expression EXPR and create access structures for all accesses to
964 candidates for scalarization. Return true if any access has been inserted.
965 STMT must be the statement from which the expression is taken, WRITE must be
966 true if the expression is a store and false otherwise. */
969 build_access_from_expr (tree expr, gimple stmt, bool write)
971 struct access *access;
973 access = build_access_from_expr_1 (expr, stmt, write);
976 /* This means the aggregate is accesses as a whole in a way other than an
977 assign statement and thus cannot be removed even if we had a scalar
978 replacement for everything. */
979 if (cannot_scalarize_away_bitmap)
980 bitmap_set_bit (cannot_scalarize_away_bitmap, DECL_UID (access->base));
986 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
987 modes in which it matters, return true iff they have been disqualified. RHS
988 may be NULL, in that case ignore it. If we scalarize an aggregate in
989 intra-SRA we may need to add statements after each statement. This is not
990 possible if a statement unconditionally has to end the basic block. */
992 disqualify_ops_if_throwing_stmt (gimple stmt, tree lhs, tree rhs)
994 if ((sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
995 && (stmt_can_throw_internal (stmt) || stmt_ends_bb_p (stmt)))
997 disqualify_base_of_expr (lhs, "LHS of a throwing stmt.");
999 disqualify_base_of_expr (rhs, "RHS of a throwing stmt.");
1005 /* Scan expressions occuring in STMT, create access structures for all accesses
1006 to candidates for scalarization and remove those candidates which occur in
1007 statements or expressions that prevent them from being split apart. Return
1008 true if any access has been inserted. */
1011 build_accesses_from_assign (gimple stmt)
1014 struct access *lacc, *racc;
1016 if (!gimple_assign_single_p (stmt))
1019 lhs = gimple_assign_lhs (stmt);
1020 rhs = gimple_assign_rhs1 (stmt);
1022 if (disqualify_ops_if_throwing_stmt (stmt, lhs, rhs))
1025 racc = build_access_from_expr_1 (rhs, stmt, false);
1026 lacc = build_access_from_expr_1 (lhs, stmt, true);
1029 lacc->grp_assignment_write = 1;
1033 racc->grp_assignment_read = 1;
1034 if (should_scalarize_away_bitmap && !gimple_has_volatile_ops (stmt)
1035 && !is_gimple_reg_type (racc->type))
1036 bitmap_set_bit (should_scalarize_away_bitmap, DECL_UID (racc->base));
1040 && (sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1041 && !lacc->grp_unscalarizable_region
1042 && !racc->grp_unscalarizable_region
1043 && AGGREGATE_TYPE_P (TREE_TYPE (lhs))
1044 /* FIXME: Turn the following line into an assert after PR 40058 is
1046 && lacc->size == racc->size
1047 && useless_type_conversion_p (lacc->type, racc->type))
1049 struct assign_link *link;
1051 link = (struct assign_link *) pool_alloc (link_pool);
1052 memset (link, 0, sizeof (struct assign_link));
1057 add_link_to_rhs (racc, link);
1060 return lacc || racc;
1063 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1064 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1067 asm_visit_addr (gimple stmt ATTRIBUTE_UNUSED, tree op,
1068 void *data ATTRIBUTE_UNUSED)
1070 op = get_base_address (op);
1073 disqualify_candidate (op, "Non-scalarizable GIMPLE_ASM operand.");
1078 /* Return true iff callsite CALL has at least as many actual arguments as there
1079 are formal parameters of the function currently processed by IPA-SRA. */
1082 callsite_has_enough_arguments_p (gimple call)
1084 return gimple_call_num_args (call) >= (unsigned) func_param_count;
1087 /* Scan function and look for interesting expressions and create access
1088 structures for them. Return true iff any access is created. */
1091 scan_function (void)
1098 gimple_stmt_iterator gsi;
1099 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1101 gimple stmt = gsi_stmt (gsi);
1105 if (final_bbs && stmt_can_throw_external (stmt))
1106 bitmap_set_bit (final_bbs, bb->index);
1107 switch (gimple_code (stmt))
1110 t = gimple_return_retval (stmt);
1112 ret |= build_access_from_expr (t, stmt, false);
1114 bitmap_set_bit (final_bbs, bb->index);
1118 ret |= build_accesses_from_assign (stmt);
1122 for (i = 0; i < gimple_call_num_args (stmt); i++)
1123 ret |= build_access_from_expr (gimple_call_arg (stmt, i),
1126 if (sra_mode == SRA_MODE_EARLY_IPA)
1128 tree dest = gimple_call_fndecl (stmt);
1129 int flags = gimple_call_flags (stmt);
1133 if (DECL_BUILT_IN_CLASS (dest) == BUILT_IN_NORMAL
1134 && DECL_FUNCTION_CODE (dest) == BUILT_IN_APPLY_ARGS)
1135 encountered_apply_args = true;
1136 if (cgraph_get_node (dest)
1137 == cgraph_get_node (current_function_decl))
1139 encountered_recursive_call = true;
1140 if (!callsite_has_enough_arguments_p (stmt))
1141 encountered_unchangable_recursive_call = true;
1146 && (flags & (ECF_CONST | ECF_PURE)) == 0)
1147 bitmap_set_bit (final_bbs, bb->index);
1150 t = gimple_call_lhs (stmt);
1151 if (t && !disqualify_ops_if_throwing_stmt (stmt, t, NULL))
1152 ret |= build_access_from_expr (t, stmt, true);
1156 walk_stmt_load_store_addr_ops (stmt, NULL, NULL, NULL,
1159 bitmap_set_bit (final_bbs, bb->index);
1161 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
1163 t = TREE_VALUE (gimple_asm_input_op (stmt, i));
1164 ret |= build_access_from_expr (t, stmt, false);
1166 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
1168 t = TREE_VALUE (gimple_asm_output_op (stmt, i));
1169 ret |= build_access_from_expr (t, stmt, true);
1182 /* Helper of QSORT function. There are pointers to accesses in the array. An
1183 access is considered smaller than another if it has smaller offset or if the
1184 offsets are the same but is size is bigger. */
1187 compare_access_positions (const void *a, const void *b)
1189 const access_p *fp1 = (const access_p *) a;
1190 const access_p *fp2 = (const access_p *) b;
1191 const access_p f1 = *fp1;
1192 const access_p f2 = *fp2;
1194 if (f1->offset != f2->offset)
1195 return f1->offset < f2->offset ? -1 : 1;
1197 if (f1->size == f2->size)
1199 if (f1->type == f2->type)
1201 /* Put any non-aggregate type before any aggregate type. */
1202 else if (!is_gimple_reg_type (f1->type)
1203 && is_gimple_reg_type (f2->type))
1205 else if (is_gimple_reg_type (f1->type)
1206 && !is_gimple_reg_type (f2->type))
1208 /* Put any complex or vector type before any other scalar type. */
1209 else if (TREE_CODE (f1->type) != COMPLEX_TYPE
1210 && TREE_CODE (f1->type) != VECTOR_TYPE
1211 && (TREE_CODE (f2->type) == COMPLEX_TYPE
1212 || TREE_CODE (f2->type) == VECTOR_TYPE))
1214 else if ((TREE_CODE (f1->type) == COMPLEX_TYPE
1215 || TREE_CODE (f1->type) == VECTOR_TYPE)
1216 && TREE_CODE (f2->type) != COMPLEX_TYPE
1217 && TREE_CODE (f2->type) != VECTOR_TYPE)
1219 /* Put the integral type with the bigger precision first. */
1220 else if (INTEGRAL_TYPE_P (f1->type)
1221 && INTEGRAL_TYPE_P (f2->type))
1222 return TYPE_PRECISION (f2->type) - TYPE_PRECISION (f1->type);
1223 /* Put any integral type with non-full precision last. */
1224 else if (INTEGRAL_TYPE_P (f1->type)
1225 && (TREE_INT_CST_LOW (TYPE_SIZE (f1->type))
1226 != TYPE_PRECISION (f1->type)))
1228 else if (INTEGRAL_TYPE_P (f2->type)
1229 && (TREE_INT_CST_LOW (TYPE_SIZE (f2->type))
1230 != TYPE_PRECISION (f2->type)))
1232 /* Stabilize the sort. */
1233 return TYPE_UID (f1->type) - TYPE_UID (f2->type);
1236 /* We want the bigger accesses first, thus the opposite operator in the next
1238 return f1->size > f2->size ? -1 : 1;
1242 /* Append a name of the declaration to the name obstack. A helper function for
1246 make_fancy_decl_name (tree decl)
1250 tree name = DECL_NAME (decl);
1252 obstack_grow (&name_obstack, IDENTIFIER_POINTER (name),
1253 IDENTIFIER_LENGTH (name));
1256 sprintf (buffer, "D%u", DECL_UID (decl));
1257 obstack_grow (&name_obstack, buffer, strlen (buffer));
1261 /* Helper for make_fancy_name. */
1264 make_fancy_name_1 (tree expr)
1271 make_fancy_decl_name (expr);
1275 switch (TREE_CODE (expr))
1278 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1279 obstack_1grow (&name_obstack, '$');
1280 make_fancy_decl_name (TREE_OPERAND (expr, 1));
1284 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1285 obstack_1grow (&name_obstack, '$');
1286 /* Arrays with only one element may not have a constant as their
1288 index = TREE_OPERAND (expr, 1);
1289 if (TREE_CODE (index) != INTEGER_CST)
1291 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC, TREE_INT_CST_LOW (index));
1292 obstack_grow (&name_obstack, buffer, strlen (buffer));
1296 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1300 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1301 if (!integer_zerop (TREE_OPERAND (expr, 1)))
1303 obstack_1grow (&name_obstack, '$');
1304 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC,
1305 TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)));
1306 obstack_grow (&name_obstack, buffer, strlen (buffer));
1313 gcc_unreachable (); /* we treat these as scalars. */
1320 /* Create a human readable name for replacement variable of ACCESS. */
1323 make_fancy_name (tree expr)
1325 make_fancy_name_1 (expr);
1326 obstack_1grow (&name_obstack, '\0');
1327 return XOBFINISH (&name_obstack, char *);
1330 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1331 EXP_TYPE at the given OFFSET. If BASE is something for which
1332 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1333 to insert new statements either before or below the current one as specified
1334 by INSERT_AFTER. This function is not capable of handling bitfields. */
1337 build_ref_for_offset (location_t loc, tree base, HOST_WIDE_INT offset,
1338 tree exp_type, gimple_stmt_iterator *gsi,
1341 tree prev_base = base;
1343 HOST_WIDE_INT base_offset;
1345 gcc_checking_assert (offset % BITS_PER_UNIT == 0);
1347 base = get_addr_base_and_unit_offset (base, &base_offset);
1349 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1350 offset such as array[var_index]. */
1356 gcc_checking_assert (gsi);
1357 tmp = create_tmp_reg (build_pointer_type (TREE_TYPE (prev_base)), NULL);
1358 add_referenced_var (tmp);
1359 tmp = make_ssa_name (tmp, NULL);
1360 addr = build_fold_addr_expr (unshare_expr (prev_base));
1361 stmt = gimple_build_assign (tmp, addr);
1362 gimple_set_location (stmt, loc);
1363 SSA_NAME_DEF_STMT (tmp) = stmt;
1365 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
1367 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1370 off = build_int_cst (reference_alias_ptr_type (prev_base),
1371 offset / BITS_PER_UNIT);
1374 else if (TREE_CODE (base) == MEM_REF)
1376 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1377 base_offset + offset / BITS_PER_UNIT);
1378 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off, 0);
1379 base = unshare_expr (TREE_OPERAND (base, 0));
1383 off = build_int_cst (reference_alias_ptr_type (base),
1384 base_offset + offset / BITS_PER_UNIT);
1385 base = build_fold_addr_expr (unshare_expr (base));
1388 return fold_build2_loc (loc, MEM_REF, exp_type, base, off);
1391 /* Construct a memory reference to a part of an aggregate BASE at the given
1392 OFFSET and of the same type as MODEL. In case this is a reference to a
1393 bit-field, the function will replicate the last component_ref of model's
1394 expr to access it. GSI and INSERT_AFTER have the same meaning as in
1395 build_ref_for_offset. */
1398 build_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1399 struct access *model, gimple_stmt_iterator *gsi,
1402 if (TREE_CODE (model->expr) == COMPONENT_REF
1403 && DECL_BIT_FIELD (TREE_OPERAND (model->expr, 1)))
1405 /* This access represents a bit-field. */
1408 offset -= int_bit_position (TREE_OPERAND (model->expr, 1));
1409 exp_type = TREE_TYPE (TREE_OPERAND (model->expr, 0));
1410 t = build_ref_for_offset (loc, base, offset, exp_type, gsi, insert_after);
1411 return fold_build3_loc (loc, COMPONENT_REF, model->type, t,
1412 TREE_OPERAND (model->expr, 1), NULL_TREE);
1415 return build_ref_for_offset (loc, base, offset, model->type,
1419 /* Construct a memory reference consisting of component_refs and array_refs to
1420 a part of an aggregate *RES (which is of type TYPE). The requested part
1421 should have type EXP_TYPE at be the given OFFSET. This function might not
1422 succeed, it returns true when it does and only then *RES points to something
1423 meaningful. This function should be used only to build expressions that we
1424 might need to present to user (e.g. in warnings). In all other situations,
1425 build_ref_for_model or build_ref_for_offset should be used instead. */
1428 build_user_friendly_ref_for_offset (tree *res, tree type, HOST_WIDE_INT offset,
1434 tree tr_size, index, minidx;
1435 HOST_WIDE_INT el_size;
1437 if (offset == 0 && exp_type
1438 && types_compatible_p (exp_type, type))
1441 switch (TREE_CODE (type))
1444 case QUAL_UNION_TYPE:
1446 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
1448 HOST_WIDE_INT pos, size;
1449 tree expr, *expr_ptr;
1451 if (TREE_CODE (fld) != FIELD_DECL)
1454 pos = int_bit_position (fld);
1455 gcc_assert (TREE_CODE (type) == RECORD_TYPE || pos == 0);
1456 tr_size = DECL_SIZE (fld);
1457 if (!tr_size || !host_integerp (tr_size, 1))
1459 size = tree_low_cst (tr_size, 1);
1465 else if (pos > offset || (pos + size) <= offset)
1468 expr = build3 (COMPONENT_REF, TREE_TYPE (fld), *res, fld,
1471 if (build_user_friendly_ref_for_offset (expr_ptr, TREE_TYPE (fld),
1472 offset - pos, exp_type))
1481 tr_size = TYPE_SIZE (TREE_TYPE (type));
1482 if (!tr_size || !host_integerp (tr_size, 1))
1484 el_size = tree_low_cst (tr_size, 1);
1486 minidx = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
1487 if (TREE_CODE (minidx) != INTEGER_CST || el_size == 0)
1489 index = build_int_cst (TYPE_DOMAIN (type), offset / el_size);
1490 if (!integer_zerop (minidx))
1491 index = int_const_binop (PLUS_EXPR, index, minidx, 0);
1492 *res = build4 (ARRAY_REF, TREE_TYPE (type), *res, index,
1493 NULL_TREE, NULL_TREE);
1494 offset = offset % el_size;
1495 type = TREE_TYPE (type);
1510 /* Return true iff TYPE is stdarg va_list type. */
1513 is_va_list_type (tree type)
1515 return TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (va_list_type_node);
1518 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1519 those with type which is suitable for scalarization. */
1522 find_var_candidates (void)
1525 referenced_var_iterator rvi;
1528 FOR_EACH_REFERENCED_VAR (var, rvi)
1530 if (TREE_CODE (var) != VAR_DECL && TREE_CODE (var) != PARM_DECL)
1532 type = TREE_TYPE (var);
1534 if (!AGGREGATE_TYPE_P (type)
1535 || needs_to_live_in_memory (var)
1536 || TREE_THIS_VOLATILE (var)
1537 || !COMPLETE_TYPE_P (type)
1538 || !host_integerp (TYPE_SIZE (type), 1)
1539 || tree_low_cst (TYPE_SIZE (type), 1) == 0
1540 || type_internals_preclude_sra_p (type)
1541 /* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1542 we also want to schedule it rather late. Thus we ignore it in
1544 || (sra_mode == SRA_MODE_EARLY_INTRA
1545 && is_va_list_type (type)))
1548 bitmap_set_bit (candidate_bitmap, DECL_UID (var));
1550 if (dump_file && (dump_flags & TDF_DETAILS))
1552 fprintf (dump_file, "Candidate (%d): ", DECL_UID (var));
1553 print_generic_expr (dump_file, var, 0);
1554 fprintf (dump_file, "\n");
1562 /* Sort all accesses for the given variable, check for partial overlaps and
1563 return NULL if there are any. If there are none, pick a representative for
1564 each combination of offset and size and create a linked list out of them.
1565 Return the pointer to the first representative and make sure it is the first
1566 one in the vector of accesses. */
1568 static struct access *
1569 sort_and_splice_var_accesses (tree var)
1571 int i, j, access_count;
1572 struct access *res, **prev_acc_ptr = &res;
1573 VEC (access_p, heap) *access_vec;
1575 HOST_WIDE_INT low = -1, high = 0;
1577 access_vec = get_base_access_vector (var);
1580 access_count = VEC_length (access_p, access_vec);
1582 /* Sort by <OFFSET, SIZE>. */
1583 VEC_qsort (access_p, access_vec, compare_access_positions);
1586 while (i < access_count)
1588 struct access *access = VEC_index (access_p, access_vec, i);
1589 bool grp_write = access->write;
1590 bool grp_read = !access->write;
1591 bool grp_assignment_read = access->grp_assignment_read;
1592 bool grp_assignment_write = access->grp_assignment_write;
1593 bool multiple_reads = false;
1594 bool total_scalarization = access->total_scalarization;
1595 bool grp_partial_lhs = access->grp_partial_lhs;
1596 bool first_scalar = is_gimple_reg_type (access->type);
1597 bool unscalarizable_region = access->grp_unscalarizable_region;
1599 if (first || access->offset >= high)
1602 low = access->offset;
1603 high = access->offset + access->size;
1605 else if (access->offset > low && access->offset + access->size > high)
1608 gcc_assert (access->offset >= low
1609 && access->offset + access->size <= high);
1612 while (j < access_count)
1614 struct access *ac2 = VEC_index (access_p, access_vec, j);
1615 if (ac2->offset != access->offset || ac2->size != access->size)
1622 multiple_reads = true;
1626 grp_assignment_read |= ac2->grp_assignment_read;
1627 grp_assignment_write |= ac2->grp_assignment_write;
1628 grp_partial_lhs |= ac2->grp_partial_lhs;
1629 unscalarizable_region |= ac2->grp_unscalarizable_region;
1630 total_scalarization |= ac2->total_scalarization;
1631 relink_to_new_repr (access, ac2);
1633 /* If there are both aggregate-type and scalar-type accesses with
1634 this combination of size and offset, the comparison function
1635 should have put the scalars first. */
1636 gcc_assert (first_scalar || !is_gimple_reg_type (ac2->type));
1637 ac2->group_representative = access;
1643 access->group_representative = access;
1644 access->grp_write = grp_write;
1645 access->grp_read = grp_read;
1646 access->grp_assignment_read = grp_assignment_read;
1647 access->grp_assignment_write = grp_assignment_write;
1648 access->grp_hint = multiple_reads || total_scalarization;
1649 access->grp_partial_lhs = grp_partial_lhs;
1650 access->grp_unscalarizable_region = unscalarizable_region;
1651 if (access->first_link)
1652 add_access_to_work_queue (access);
1654 *prev_acc_ptr = access;
1655 prev_acc_ptr = &access->next_grp;
1658 gcc_assert (res == VEC_index (access_p, access_vec, 0));
1662 /* Create a variable for the given ACCESS which determines the type, name and a
1663 few other properties. Return the variable declaration and store it also to
1664 ACCESS->replacement. */
1667 create_access_replacement (struct access *access, bool rename)
1671 repl = create_tmp_var (access->type, "SR");
1673 add_referenced_var (repl);
1675 mark_sym_for_renaming (repl);
1677 if (!access->grp_partial_lhs
1678 && (TREE_CODE (access->type) == COMPLEX_TYPE
1679 || TREE_CODE (access->type) == VECTOR_TYPE))
1680 DECL_GIMPLE_REG_P (repl) = 1;
1682 DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
1683 DECL_ARTIFICIAL (repl) = 1;
1684 DECL_IGNORED_P (repl) = DECL_IGNORED_P (access->base);
1686 if (DECL_NAME (access->base)
1687 && !DECL_IGNORED_P (access->base)
1688 && !DECL_ARTIFICIAL (access->base))
1690 char *pretty_name = make_fancy_name (access->expr);
1691 tree debug_expr = unshare_expr (access->expr), d;
1693 DECL_NAME (repl) = get_identifier (pretty_name);
1694 obstack_free (&name_obstack, pretty_name);
1696 /* Get rid of any SSA_NAMEs embedded in debug_expr,
1697 as DECL_DEBUG_EXPR isn't considered when looking for still
1698 used SSA_NAMEs and thus they could be freed. All debug info
1699 generation cares is whether something is constant or variable
1700 and that get_ref_base_and_extent works properly on the
1702 for (d = debug_expr; handled_component_p (d); d = TREE_OPERAND (d, 0))
1703 switch (TREE_CODE (d))
1706 case ARRAY_RANGE_REF:
1707 if (TREE_OPERAND (d, 1)
1708 && TREE_CODE (TREE_OPERAND (d, 1)) == SSA_NAME)
1709 TREE_OPERAND (d, 1) = SSA_NAME_VAR (TREE_OPERAND (d, 1));
1710 if (TREE_OPERAND (d, 3)
1711 && TREE_CODE (TREE_OPERAND (d, 3)) == SSA_NAME)
1712 TREE_OPERAND (d, 3) = SSA_NAME_VAR (TREE_OPERAND (d, 3));
1715 if (TREE_OPERAND (d, 2)
1716 && TREE_CODE (TREE_OPERAND (d, 2)) == SSA_NAME)
1717 TREE_OPERAND (d, 2) = SSA_NAME_VAR (TREE_OPERAND (d, 2));
1722 SET_DECL_DEBUG_EXPR (repl, debug_expr);
1723 DECL_DEBUG_EXPR_IS_FROM (repl) = 1;
1724 if (access->grp_no_warning)
1725 TREE_NO_WARNING (repl) = 1;
1727 TREE_NO_WARNING (repl) = TREE_NO_WARNING (access->base);
1730 TREE_NO_WARNING (repl) = 1;
1734 fprintf (dump_file, "Created a replacement for ");
1735 print_generic_expr (dump_file, access->base, 0);
1736 fprintf (dump_file, " offset: %u, size: %u: ",
1737 (unsigned) access->offset, (unsigned) access->size);
1738 print_generic_expr (dump_file, repl, 0);
1739 fprintf (dump_file, "\n");
1741 sra_stats.replacements++;
1746 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
1749 get_access_replacement (struct access *access)
1751 gcc_assert (access->grp_to_be_replaced);
1753 if (!access->replacement_decl)
1754 access->replacement_decl = create_access_replacement (access, true);
1755 return access->replacement_decl;
1758 /* Return ACCESS scalar replacement, create it if it does not exist yet but do
1759 not mark it for renaming. */
1762 get_unrenamed_access_replacement (struct access *access)
1764 gcc_assert (!access->grp_to_be_replaced);
1766 if (!access->replacement_decl)
1767 access->replacement_decl = create_access_replacement (access, false);
1768 return access->replacement_decl;
1772 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
1773 linked list along the way. Stop when *ACCESS is NULL or the access pointed
1774 to it is not "within" the root. Return false iff some accesses partially
1778 build_access_subtree (struct access **access)
1780 struct access *root = *access, *last_child = NULL;
1781 HOST_WIDE_INT limit = root->offset + root->size;
1783 *access = (*access)->next_grp;
1784 while (*access && (*access)->offset + (*access)->size <= limit)
1787 root->first_child = *access;
1789 last_child->next_sibling = *access;
1790 last_child = *access;
1792 if (!build_access_subtree (access))
1796 if (*access && (*access)->offset < limit)
1802 /* Build a tree of access representatives, ACCESS is the pointer to the first
1803 one, others are linked in a list by the next_grp field. Return false iff
1804 some accesses partially overlap. */
1807 build_access_trees (struct access *access)
1811 struct access *root = access;
1813 if (!build_access_subtree (&access))
1815 root->next_grp = access;
1820 /* Return true if expr contains some ARRAY_REFs into a variable bounded
1824 expr_with_var_bounded_array_refs_p (tree expr)
1826 while (handled_component_p (expr))
1828 if (TREE_CODE (expr) == ARRAY_REF
1829 && !host_integerp (array_ref_low_bound (expr), 0))
1831 expr = TREE_OPERAND (expr, 0);
1836 enum mark_rw_status { SRA_MRRW_NOTHING, SRA_MRRW_DIRECT, SRA_MRRW_ASSIGN};
1838 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
1839 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
1840 sorts of access flags appropriately along the way, notably always set
1841 grp_read and grp_assign_read according to MARK_READ and grp_write when
1844 Creating a replacement for a scalar access is considered beneficial if its
1845 grp_hint is set (this means we are either attempting total scalarization or
1846 there is more than one direct read access) or according to the following
1849 Access written to individually (once or more times)
1851 | Parent written to in an assignment statement
1853 | | Access read individually _once_
1855 | | | Parent read in an assignment statement
1857 | | | | Scalarize Comment
1858 -----------------------------------------------------------------------------
1859 0 0 0 0 No access for the scalar
1860 0 0 0 1 No access for the scalar
1861 0 0 1 0 No Single read - won't help
1862 0 0 1 1 No The same case
1863 0 1 0 0 No access for the scalar
1864 0 1 0 1 No access for the scalar
1865 0 1 1 0 Yes s = *g; return s.i;
1866 0 1 1 1 Yes The same case as above
1867 1 0 0 0 No Won't help
1868 1 0 0 1 Yes s.i = 1; *g = s;
1869 1 0 1 0 Yes s.i = 5; g = s.i;
1870 1 0 1 1 Yes The same case as above
1871 1 1 0 0 No Won't help.
1872 1 1 0 1 Yes s.i = 1; *g = s;
1873 1 1 1 0 Yes s = *g; return s.i;
1874 1 1 1 1 Yes Any of the above yeses */
1877 analyze_access_subtree (struct access *root, bool allow_replacements,
1878 enum mark_rw_status mark_read,
1879 enum mark_rw_status mark_write)
1881 struct access *child;
1882 HOST_WIDE_INT limit = root->offset + root->size;
1883 HOST_WIDE_INT covered_to = root->offset;
1884 bool scalar = is_gimple_reg_type (root->type);
1885 bool hole = false, sth_created = false;
1886 bool direct_read = root->grp_read;
1887 bool direct_write = root->grp_write;
1889 if (root->grp_assignment_read)
1890 mark_read = SRA_MRRW_ASSIGN;
1891 else if (mark_read == SRA_MRRW_ASSIGN)
1894 root->grp_assignment_read = 1;
1896 else if (mark_read == SRA_MRRW_DIRECT)
1898 else if (root->grp_read)
1899 mark_read = SRA_MRRW_DIRECT;
1901 if (root->grp_assignment_write)
1902 mark_write = SRA_MRRW_ASSIGN;
1903 else if (mark_write == SRA_MRRW_ASSIGN)
1905 root->grp_write = 1;
1906 root->grp_assignment_write = 1;
1908 else if (mark_write == SRA_MRRW_DIRECT)
1909 root->grp_write = 1;
1910 else if (root->grp_write)
1911 mark_write = SRA_MRRW_DIRECT;
1913 if (root->grp_unscalarizable_region)
1914 allow_replacements = false;
1916 if (allow_replacements && expr_with_var_bounded_array_refs_p (root->expr))
1917 allow_replacements = false;
1919 for (child = root->first_child; child; child = child->next_sibling)
1921 if (!hole && child->offset < covered_to)
1924 covered_to += child->size;
1926 sth_created |= analyze_access_subtree (child,
1927 allow_replacements && !scalar,
1928 mark_read, mark_write);
1930 root->grp_unscalarized_data |= child->grp_unscalarized_data;
1931 hole |= !child->grp_covered;
1934 if (allow_replacements && scalar && !root->first_child
1936 || ((direct_write || root->grp_assignment_write)
1937 && (direct_read || root->grp_assignment_read))))
1939 if (dump_file && (dump_flags & TDF_DETAILS))
1941 fprintf (dump_file, "Marking ");
1942 print_generic_expr (dump_file, root->base, 0);
1943 fprintf (dump_file, " offset: %u, size: %u: ",
1944 (unsigned) root->offset, (unsigned) root->size);
1945 fprintf (dump_file, " to be replaced.\n");
1948 root->grp_to_be_replaced = 1;
1952 else if (covered_to < limit)
1955 if (sth_created && !hole)
1957 root->grp_covered = 1;
1960 if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
1961 root->grp_unscalarized_data = 1; /* not covered and written to */
1967 /* Analyze all access trees linked by next_grp by the means of
1968 analyze_access_subtree. */
1970 analyze_access_trees (struct access *access)
1976 if (analyze_access_subtree (access, true,
1977 SRA_MRRW_NOTHING, SRA_MRRW_NOTHING))
1979 access = access->next_grp;
1985 /* Return true iff a potential new child of LACC at offset OFFSET and with size
1986 SIZE would conflict with an already existing one. If exactly such a child
1987 already exists in LACC, store a pointer to it in EXACT_MATCH. */
1990 child_would_conflict_in_lacc (struct access *lacc, HOST_WIDE_INT norm_offset,
1991 HOST_WIDE_INT size, struct access **exact_match)
1993 struct access *child;
1995 for (child = lacc->first_child; child; child = child->next_sibling)
1997 if (child->offset == norm_offset && child->size == size)
1999 *exact_match = child;
2003 if (child->offset < norm_offset + size
2004 && child->offset + child->size > norm_offset)
2011 /* Create a new child access of PARENT, with all properties just like MODEL
2012 except for its offset and with its grp_write false and grp_read true.
2013 Return the new access or NULL if it cannot be created. Note that this access
2014 is created long after all splicing and sorting, it's not located in any
2015 access vector and is automatically a representative of its group. */
2017 static struct access *
2018 create_artificial_child_access (struct access *parent, struct access *model,
2019 HOST_WIDE_INT new_offset)
2021 struct access *access;
2022 struct access **child;
2023 tree expr = parent->base;
2025 gcc_assert (!model->grp_unscalarizable_region);
2027 access = (struct access *) pool_alloc (access_pool);
2028 memset (access, 0, sizeof (struct access));
2029 if (!build_user_friendly_ref_for_offset (&expr, TREE_TYPE (expr), new_offset,
2032 access->grp_no_warning = true;
2033 expr = build_ref_for_model (EXPR_LOCATION (parent->base), parent->base,
2034 new_offset, model, NULL, false);
2037 access->base = parent->base;
2038 access->expr = expr;
2039 access->offset = new_offset;
2040 access->size = model->size;
2041 access->type = model->type;
2042 access->grp_write = true;
2043 access->grp_read = false;
2045 child = &parent->first_child;
2046 while (*child && (*child)->offset < new_offset)
2047 child = &(*child)->next_sibling;
2049 access->next_sibling = *child;
2056 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2057 true if any new subaccess was created. Additionally, if RACC is a scalar
2058 access but LACC is not, change the type of the latter, if possible. */
2061 propagate_subaccesses_across_link (struct access *lacc, struct access *racc)
2063 struct access *rchild;
2064 HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
2067 if (is_gimple_reg_type (lacc->type)
2068 || lacc->grp_unscalarizable_region
2069 || racc->grp_unscalarizable_region)
2072 if (!lacc->first_child && !racc->first_child
2073 && is_gimple_reg_type (racc->type))
2075 tree t = lacc->base;
2077 lacc->type = racc->type;
2078 if (build_user_friendly_ref_for_offset (&t, TREE_TYPE (t), lacc->offset,
2083 lacc->expr = build_ref_for_model (EXPR_LOCATION (lacc->base),
2084 lacc->base, lacc->offset,
2086 lacc->grp_no_warning = true;
2091 for (rchild = racc->first_child; rchild; rchild = rchild->next_sibling)
2093 struct access *new_acc = NULL;
2094 HOST_WIDE_INT norm_offset = rchild->offset + norm_delta;
2096 if (rchild->grp_unscalarizable_region)
2099 if (child_would_conflict_in_lacc (lacc, norm_offset, rchild->size,
2104 rchild->grp_hint = 1;
2105 new_acc->grp_hint |= new_acc->grp_read;
2106 if (rchild->first_child)
2107 ret |= propagate_subaccesses_across_link (new_acc, rchild);
2112 rchild->grp_hint = 1;
2113 new_acc = create_artificial_child_access (lacc, rchild, norm_offset);
2117 if (racc->first_child)
2118 propagate_subaccesses_across_link (new_acc, rchild);
2125 /* Propagate all subaccesses across assignment links. */
2128 propagate_all_subaccesses (void)
2130 while (work_queue_head)
2132 struct access *racc = pop_access_from_work_queue ();
2133 struct assign_link *link;
2135 gcc_assert (racc->first_link);
2137 for (link = racc->first_link; link; link = link->next)
2139 struct access *lacc = link->lacc;
2141 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (lacc->base)))
2143 lacc = lacc->group_representative;
2144 if (propagate_subaccesses_across_link (lacc, racc)
2145 && lacc->first_link)
2146 add_access_to_work_queue (lacc);
2151 /* Go through all accesses collected throughout the (intraprocedural) analysis
2152 stage, exclude overlapping ones, identify representatives and build trees
2153 out of them, making decisions about scalarization on the way. Return true
2154 iff there are any to-be-scalarized variables after this stage. */
2157 analyze_all_variable_accesses (void)
2160 bitmap tmp = BITMAP_ALLOC (NULL);
2162 unsigned i, max_total_scalarization_size;
2164 max_total_scalarization_size = UNITS_PER_WORD * BITS_PER_UNIT
2165 * MOVE_RATIO (optimize_function_for_speed_p (cfun));
2167 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
2168 if (bitmap_bit_p (should_scalarize_away_bitmap, i)
2169 && !bitmap_bit_p (cannot_scalarize_away_bitmap, i))
2171 tree var = referenced_var (i);
2173 if (TREE_CODE (var) == VAR_DECL
2174 && ((unsigned) tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1)
2175 <= max_total_scalarization_size)
2176 && type_consists_of_records_p (TREE_TYPE (var)))
2178 completely_scalarize_record (var, var, 0, var);
2179 if (dump_file && (dump_flags & TDF_DETAILS))
2181 fprintf (dump_file, "Will attempt to totally scalarize ");
2182 print_generic_expr (dump_file, var, 0);
2183 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2188 bitmap_copy (tmp, candidate_bitmap);
2189 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2191 tree var = referenced_var (i);
2192 struct access *access;
2194 access = sort_and_splice_var_accesses (var);
2195 if (!access || !build_access_trees (access))
2196 disqualify_candidate (var,
2197 "No or inhibitingly overlapping accesses.");
2200 propagate_all_subaccesses ();
2202 bitmap_copy (tmp, candidate_bitmap);
2203 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2205 tree var = referenced_var (i);
2206 struct access *access = get_first_repr_for_decl (var);
2208 if (analyze_access_trees (access))
2211 if (dump_file && (dump_flags & TDF_DETAILS))
2213 fprintf (dump_file, "\nAccess trees for ");
2214 print_generic_expr (dump_file, var, 0);
2215 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2216 dump_access_tree (dump_file, access);
2217 fprintf (dump_file, "\n");
2221 disqualify_candidate (var, "No scalar replacements to be created.");
2228 statistics_counter_event (cfun, "Scalarized aggregates", res);
2235 /* Generate statements copying scalar replacements of accesses within a subtree
2236 into or out of AGG. ACCESS, all its children, siblings and their children
2237 are to be processed. AGG is an aggregate type expression (can be a
2238 declaration but does not have to be, it can for example also be a mem_ref or
2239 a series of handled components). TOP_OFFSET is the offset of the processed
2240 subtree which has to be subtracted from offsets of individual accesses to
2241 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2242 replacements in the interval <start_offset, start_offset + chunk_size>,
2243 otherwise copy all. GSI is a statement iterator used to place the new
2244 statements. WRITE should be true when the statements should write from AGG
2245 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2246 statements will be added after the current statement in GSI, they will be
2247 added before the statement otherwise. */
2250 generate_subtree_copies (struct access *access, tree agg,
2251 HOST_WIDE_INT top_offset,
2252 HOST_WIDE_INT start_offset, HOST_WIDE_INT chunk_size,
2253 gimple_stmt_iterator *gsi, bool write,
2254 bool insert_after, location_t loc)
2258 if (chunk_size && access->offset >= start_offset + chunk_size)
2261 if (access->grp_to_be_replaced
2263 || access->offset + access->size > start_offset))
2265 tree expr, repl = get_access_replacement (access);
2268 expr = build_ref_for_model (loc, agg, access->offset - top_offset,
2269 access, gsi, insert_after);
2273 if (access->grp_partial_lhs)
2274 expr = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE,
2276 insert_after ? GSI_NEW_STMT
2278 stmt = gimple_build_assign (repl, expr);
2282 TREE_NO_WARNING (repl) = 1;
2283 if (access->grp_partial_lhs)
2284 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2286 insert_after ? GSI_NEW_STMT
2288 stmt = gimple_build_assign (expr, repl);
2290 gimple_set_location (stmt, loc);
2293 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2295 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2297 sra_stats.subtree_copies++;
2300 if (access->first_child)
2301 generate_subtree_copies (access->first_child, agg, top_offset,
2302 start_offset, chunk_size, gsi,
2303 write, insert_after, loc);
2305 access = access->next_sibling;
2310 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2311 the root of the subtree to be processed. GSI is the statement iterator used
2312 for inserting statements which are added after the current statement if
2313 INSERT_AFTER is true or before it otherwise. */
2316 init_subtree_with_zero (struct access *access, gimple_stmt_iterator *gsi,
2317 bool insert_after, location_t loc)
2320 struct access *child;
2322 if (access->grp_to_be_replaced)
2326 stmt = gimple_build_assign (get_access_replacement (access),
2327 build_zero_cst (access->type));
2329 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2331 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2333 gimple_set_location (stmt, loc);
2336 for (child = access->first_child; child; child = child->next_sibling)
2337 init_subtree_with_zero (child, gsi, insert_after, loc);
2340 /* Search for an access representative for the given expression EXPR and
2341 return it or NULL if it cannot be found. */
2343 static struct access *
2344 get_access_for_expr (tree expr)
2346 HOST_WIDE_INT offset, size, max_size;
2349 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2350 a different size than the size of its argument and we need the latter
2352 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
2353 expr = TREE_OPERAND (expr, 0);
2355 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
2356 if (max_size == -1 || !DECL_P (base))
2359 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
2362 return get_var_base_offset_size_access (base, offset, max_size);
2365 /* Replace the expression EXPR with a scalar replacement if there is one and
2366 generate other statements to do type conversion or subtree copying if
2367 necessary. GSI is used to place newly created statements, WRITE is true if
2368 the expression is being written to (it is on a LHS of a statement or output
2369 in an assembly statement). */
2372 sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write)
2375 struct access *access;
2378 if (TREE_CODE (*expr) == BIT_FIELD_REF)
2381 expr = &TREE_OPERAND (*expr, 0);
2386 if (TREE_CODE (*expr) == REALPART_EXPR || TREE_CODE (*expr) == IMAGPART_EXPR)
2387 expr = &TREE_OPERAND (*expr, 0);
2388 access = get_access_for_expr (*expr);
2391 type = TREE_TYPE (*expr);
2393 loc = gimple_location (gsi_stmt (*gsi));
2394 if (access->grp_to_be_replaced)
2396 tree repl = get_access_replacement (access);
2397 /* If we replace a non-register typed access simply use the original
2398 access expression to extract the scalar component afterwards.
2399 This happens if scalarizing a function return value or parameter
2400 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2401 gcc.c-torture/compile/20011217-1.c.
2403 We also want to use this when accessing a complex or vector which can
2404 be accessed as a different type too, potentially creating a need for
2405 type conversion (see PR42196) and when scalarized unions are involved
2406 in assembler statements (see PR42398). */
2407 if (!useless_type_conversion_p (type, access->type))
2411 ref = build_ref_for_model (loc, access->base, access->offset, access,
2418 if (access->grp_partial_lhs)
2419 ref = force_gimple_operand_gsi (gsi, ref, true, NULL_TREE,
2420 false, GSI_NEW_STMT);
2421 stmt = gimple_build_assign (repl, ref);
2422 gimple_set_location (stmt, loc);
2423 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2429 if (access->grp_partial_lhs)
2430 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2431 true, GSI_SAME_STMT);
2432 stmt = gimple_build_assign (ref, repl);
2433 gimple_set_location (stmt, loc);
2434 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2442 if (access->first_child)
2444 HOST_WIDE_INT start_offset, chunk_size;
2446 && host_integerp (TREE_OPERAND (bfr, 1), 1)
2447 && host_integerp (TREE_OPERAND (bfr, 2), 1))
2449 chunk_size = tree_low_cst (TREE_OPERAND (bfr, 1), 1);
2450 start_offset = access->offset
2451 + tree_low_cst (TREE_OPERAND (bfr, 2), 1);
2454 start_offset = chunk_size = 0;
2456 generate_subtree_copies (access->first_child, access->base, 0,
2457 start_offset, chunk_size, gsi, write, write,
2463 /* Where scalar replacements of the RHS have been written to when a replacement
2464 of a LHS of an assigments cannot be direclty loaded from a replacement of
2466 enum unscalarized_data_handling { SRA_UDH_NONE, /* Nothing done so far. */
2467 SRA_UDH_RIGHT, /* Data flushed to the RHS. */
2468 SRA_UDH_LEFT }; /* Data flushed to the LHS. */
2470 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2471 base aggregate if there are unscalarized data or directly to LHS of the
2472 statement that is pointed to by GSI otherwise. */
2474 static enum unscalarized_data_handling
2475 handle_unscalarized_data_in_subtree (struct access *top_racc,
2476 gimple_stmt_iterator *gsi)
2478 if (top_racc->grp_unscalarized_data)
2480 generate_subtree_copies (top_racc->first_child, top_racc->base, 0, 0, 0,
2482 gimple_location (gsi_stmt (*gsi)));
2483 return SRA_UDH_RIGHT;
2487 tree lhs = gimple_assign_lhs (gsi_stmt (*gsi));
2488 generate_subtree_copies (top_racc->first_child, lhs, top_racc->offset,
2489 0, 0, gsi, false, false,
2490 gimple_location (gsi_stmt (*gsi)));
2491 return SRA_UDH_LEFT;
2496 /* Try to generate statements to load all sub-replacements in an access subtree
2497 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2498 If that is not possible, refresh the TOP_RACC base aggregate and load the
2499 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2500 copied. NEW_GSI is stmt iterator used for statement insertions after the
2501 original assignment, OLD_GSI is used to insert statements before the
2502 assignment. *REFRESHED keeps the information whether we have needed to
2503 refresh replacements of the LHS and from which side of the assignments this
2507 load_assign_lhs_subreplacements (struct access *lacc, struct access *top_racc,
2508 HOST_WIDE_INT left_offset,
2509 gimple_stmt_iterator *old_gsi,
2510 gimple_stmt_iterator *new_gsi,
2511 enum unscalarized_data_handling *refreshed)
2513 location_t loc = gimple_location (gsi_stmt (*old_gsi));
2514 for (lacc = lacc->first_child; lacc; lacc = lacc->next_sibling)
2516 if (lacc->grp_to_be_replaced)
2518 struct access *racc;
2519 HOST_WIDE_INT offset = lacc->offset - left_offset + top_racc->offset;
2523 racc = find_access_in_subtree (top_racc, offset, lacc->size);
2524 if (racc && racc->grp_to_be_replaced)
2526 rhs = get_access_replacement (racc);
2527 if (!useless_type_conversion_p (lacc->type, racc->type))
2528 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, lacc->type, rhs);
2532 /* No suitable access on the right hand side, need to load from
2533 the aggregate. See if we have to update it first... */
2534 if (*refreshed == SRA_UDH_NONE)
2535 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2538 if (*refreshed == SRA_UDH_LEFT)
2539 rhs = build_ref_for_model (loc, lacc->base, lacc->offset, lacc,
2542 rhs = build_ref_for_model (loc, top_racc->base, offset, lacc,
2546 stmt = gimple_build_assign (get_access_replacement (lacc), rhs);
2547 gsi_insert_after (new_gsi, stmt, GSI_NEW_STMT);
2548 gimple_set_location (stmt, loc);
2550 sra_stats.subreplacements++;
2552 else if (*refreshed == SRA_UDH_NONE
2553 && lacc->grp_read && !lacc->grp_covered)
2554 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2557 if (lacc->first_child)
2558 load_assign_lhs_subreplacements (lacc, top_racc, left_offset,
2559 old_gsi, new_gsi, refreshed);
2563 /* Result code for SRA assignment modification. */
2564 enum assignment_mod_result { SRA_AM_NONE, /* nothing done for the stmt */
2565 SRA_AM_MODIFIED, /* stmt changed but not
2567 SRA_AM_REMOVED }; /* stmt eliminated */
2569 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2570 to the assignment and GSI is the statement iterator pointing at it. Returns
2571 the same values as sra_modify_assign. */
2573 static enum assignment_mod_result
2574 sra_modify_constructor_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2576 tree lhs = gimple_assign_lhs (*stmt);
2580 acc = get_access_for_expr (lhs);
2584 loc = gimple_location (*stmt);
2585 if (VEC_length (constructor_elt,
2586 CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt))) > 0)
2588 /* I have never seen this code path trigger but if it can happen the
2589 following should handle it gracefully. */
2590 if (access_has_children_p (acc))
2591 generate_subtree_copies (acc->first_child, acc->base, 0, 0, 0, gsi,
2593 return SRA_AM_MODIFIED;
2596 if (acc->grp_covered)
2598 init_subtree_with_zero (acc, gsi, false, loc);
2599 unlink_stmt_vdef (*stmt);
2600 gsi_remove (gsi, true);
2601 return SRA_AM_REMOVED;
2605 init_subtree_with_zero (acc, gsi, true, loc);
2606 return SRA_AM_MODIFIED;
2610 /* Create and return a new suitable default definition SSA_NAME for RACC which
2611 is an access describing an uninitialized part of an aggregate that is being
2615 get_repl_default_def_ssa_name (struct access *racc)
2619 decl = get_unrenamed_access_replacement (racc);
2621 repl = gimple_default_def (cfun, decl);
2624 repl = make_ssa_name (decl, gimple_build_nop ());
2625 set_default_def (decl, repl);
2631 /* Examine both sides of the assignment statement pointed to by STMT, replace
2632 them with a scalare replacement if there is one and generate copying of
2633 replacements if scalarized aggregates have been used in the assignment. GSI
2634 is used to hold generated statements for type conversions and subtree
2637 static enum assignment_mod_result
2638 sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2640 struct access *lacc, *racc;
2642 bool modify_this_stmt = false;
2643 bool force_gimple_rhs = false;
2645 gimple_stmt_iterator orig_gsi = *gsi;
2647 if (!gimple_assign_single_p (*stmt))
2649 lhs = gimple_assign_lhs (*stmt);
2650 rhs = gimple_assign_rhs1 (*stmt);
2652 if (TREE_CODE (rhs) == CONSTRUCTOR)
2653 return sra_modify_constructor_assign (stmt, gsi);
2655 if (TREE_CODE (rhs) == REALPART_EXPR || TREE_CODE (lhs) == REALPART_EXPR
2656 || TREE_CODE (rhs) == IMAGPART_EXPR || TREE_CODE (lhs) == IMAGPART_EXPR
2657 || TREE_CODE (rhs) == BIT_FIELD_REF || TREE_CODE (lhs) == BIT_FIELD_REF)
2659 modify_this_stmt = sra_modify_expr (gimple_assign_rhs1_ptr (*stmt),
2661 modify_this_stmt |= sra_modify_expr (gimple_assign_lhs_ptr (*stmt),
2663 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
2666 lacc = get_access_for_expr (lhs);
2667 racc = get_access_for_expr (rhs);
2671 loc = gimple_location (*stmt);
2672 if (lacc && lacc->grp_to_be_replaced)
2674 lhs = get_access_replacement (lacc);
2675 gimple_assign_set_lhs (*stmt, lhs);
2676 modify_this_stmt = true;
2677 if (lacc->grp_partial_lhs)
2678 force_gimple_rhs = true;
2682 if (racc && racc->grp_to_be_replaced)
2684 rhs = get_access_replacement (racc);
2685 modify_this_stmt = true;
2686 if (racc->grp_partial_lhs)
2687 force_gimple_rhs = true;
2691 if (modify_this_stmt)
2693 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2695 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
2696 ??? This should move to fold_stmt which we simply should
2697 call after building a VIEW_CONVERT_EXPR here. */
2698 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
2699 && !access_has_children_p (lacc))
2701 lhs = build_ref_for_offset (loc, lhs, 0, TREE_TYPE (rhs),
2703 gimple_assign_set_lhs (*stmt, lhs);
2705 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs))
2706 && !contains_view_convert_expr_p (rhs)
2707 && !access_has_children_p (racc))
2708 rhs = build_ref_for_offset (loc, rhs, 0, TREE_TYPE (lhs),
2711 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2713 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, TREE_TYPE (lhs),
2715 if (is_gimple_reg_type (TREE_TYPE (lhs))
2716 && TREE_CODE (lhs) != SSA_NAME)
2717 force_gimple_rhs = true;
2722 /* From this point on, the function deals with assignments in between
2723 aggregates when at least one has scalar reductions of some of its
2724 components. There are three possible scenarios: Both the LHS and RHS have
2725 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
2727 In the first case, we would like to load the LHS components from RHS
2728 components whenever possible. If that is not possible, we would like to
2729 read it directly from the RHS (after updating it by storing in it its own
2730 components). If there are some necessary unscalarized data in the LHS,
2731 those will be loaded by the original assignment too. If neither of these
2732 cases happen, the original statement can be removed. Most of this is done
2733 by load_assign_lhs_subreplacements.
2735 In the second case, we would like to store all RHS scalarized components
2736 directly into LHS and if they cover the aggregate completely, remove the
2737 statement too. In the third case, we want the LHS components to be loaded
2738 directly from the RHS (DSE will remove the original statement if it
2741 This is a bit complex but manageable when types match and when unions do
2742 not cause confusion in a way that we cannot really load a component of LHS
2743 from the RHS or vice versa (the access representing this level can have
2744 subaccesses that are accessible only through a different union field at a
2745 higher level - different from the one used in the examined expression).
2748 Therefore, I specially handle a fourth case, happening when there is a
2749 specific type cast or it is impossible to locate a scalarized subaccess on
2750 the other side of the expression. If that happens, I simply "refresh" the
2751 RHS by storing in it is scalarized components leave the original statement
2752 there to do the copying and then load the scalar replacements of the LHS.
2753 This is what the first branch does. */
2755 if (gimple_has_volatile_ops (*stmt)
2756 || contains_view_convert_expr_p (rhs)
2757 || contains_view_convert_expr_p (lhs))
2759 if (access_has_children_p (racc))
2760 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
2761 gsi, false, false, loc);
2762 if (access_has_children_p (lacc))
2763 generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
2764 gsi, true, true, loc);
2765 sra_stats.separate_lhs_rhs_handling++;
2769 if (access_has_children_p (lacc) && access_has_children_p (racc))
2771 gimple_stmt_iterator orig_gsi = *gsi;
2772 enum unscalarized_data_handling refreshed;
2774 if (lacc->grp_read && !lacc->grp_covered)
2775 refreshed = handle_unscalarized_data_in_subtree (racc, gsi);
2777 refreshed = SRA_UDH_NONE;
2779 load_assign_lhs_subreplacements (lacc, racc, lacc->offset,
2780 &orig_gsi, gsi, &refreshed);
2781 if (refreshed != SRA_UDH_RIGHT)
2784 unlink_stmt_vdef (*stmt);
2785 gsi_remove (&orig_gsi, true);
2786 sra_stats.deleted++;
2787 return SRA_AM_REMOVED;
2794 if (!racc->grp_to_be_replaced && !racc->grp_unscalarized_data)
2798 fprintf (dump_file, "Removing load: ");
2799 print_gimple_stmt (dump_file, *stmt, 0, 0);
2802 if (TREE_CODE (lhs) == SSA_NAME)
2804 rhs = get_repl_default_def_ssa_name (racc);
2805 if (!useless_type_conversion_p (TREE_TYPE (lhs),
2807 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR,
2808 TREE_TYPE (lhs), rhs);
2812 if (racc->first_child)
2813 generate_subtree_copies (racc->first_child, lhs,
2814 racc->offset, 0, 0, gsi,
2817 gcc_assert (*stmt == gsi_stmt (*gsi));
2818 unlink_stmt_vdef (*stmt);
2819 gsi_remove (gsi, true);
2820 sra_stats.deleted++;
2821 return SRA_AM_REMOVED;
2824 else if (racc->first_child)
2825 generate_subtree_copies (racc->first_child, lhs, racc->offset,
2826 0, 0, gsi, false, true, loc);
2828 if (access_has_children_p (lacc))
2829 generate_subtree_copies (lacc->first_child, rhs, lacc->offset,
2830 0, 0, gsi, true, true, loc);
2834 /* This gimplification must be done after generate_subtree_copies, lest we
2835 insert the subtree copies in the middle of the gimplified sequence. */
2836 if (force_gimple_rhs)
2837 rhs = force_gimple_operand_gsi (&orig_gsi, rhs, true, NULL_TREE,
2838 true, GSI_SAME_STMT);
2839 if (gimple_assign_rhs1 (*stmt) != rhs)
2841 modify_this_stmt = true;
2842 gimple_assign_set_rhs_from_tree (&orig_gsi, rhs);
2843 gcc_assert (*stmt == gsi_stmt (orig_gsi));
2846 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
2849 /* Traverse the function body and all modifications as decided in
2850 analyze_all_variable_accesses. Return true iff the CFG has been
2854 sra_modify_function_body (void)
2856 bool cfg_changed = false;
2861 gimple_stmt_iterator gsi = gsi_start_bb (bb);
2862 while (!gsi_end_p (gsi))
2864 gimple stmt = gsi_stmt (gsi);
2865 enum assignment_mod_result assign_result;
2866 bool modified = false, deleted = false;
2870 switch (gimple_code (stmt))
2873 t = gimple_return_retval_ptr (stmt);
2874 if (*t != NULL_TREE)
2875 modified |= sra_modify_expr (t, &gsi, false);
2879 assign_result = sra_modify_assign (&stmt, &gsi);
2880 modified |= assign_result == SRA_AM_MODIFIED;
2881 deleted = assign_result == SRA_AM_REMOVED;
2885 /* Operands must be processed before the lhs. */
2886 for (i = 0; i < gimple_call_num_args (stmt); i++)
2888 t = gimple_call_arg_ptr (stmt, i);
2889 modified |= sra_modify_expr (t, &gsi, false);
2892 if (gimple_call_lhs (stmt))
2894 t = gimple_call_lhs_ptr (stmt);
2895 modified |= sra_modify_expr (t, &gsi, true);
2900 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
2902 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
2903 modified |= sra_modify_expr (t, &gsi, false);
2905 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
2907 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
2908 modified |= sra_modify_expr (t, &gsi, true);
2919 if (maybe_clean_eh_stmt (stmt)
2920 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
2931 /* Generate statements initializing scalar replacements of parts of function
2935 initialize_parameter_reductions (void)
2937 gimple_stmt_iterator gsi;
2938 gimple_seq seq = NULL;
2941 for (parm = DECL_ARGUMENTS (current_function_decl);
2943 parm = DECL_CHAIN (parm))
2945 VEC (access_p, heap) *access_vec;
2946 struct access *access;
2948 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
2950 access_vec = get_base_access_vector (parm);
2956 seq = gimple_seq_alloc ();
2957 gsi = gsi_start (seq);
2960 for (access = VEC_index (access_p, access_vec, 0);
2962 access = access->next_grp)
2963 generate_subtree_copies (access, parm, 0, 0, 0, &gsi, true, true,
2964 EXPR_LOCATION (parm));
2968 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR), seq);
2971 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
2972 it reveals there are components of some aggregates to be scalarized, it runs
2973 the required transformations. */
2975 perform_intra_sra (void)
2980 if (!find_var_candidates ())
2983 if (!scan_function ())
2986 if (!analyze_all_variable_accesses ())
2989 if (sra_modify_function_body ())
2990 ret = TODO_update_ssa | TODO_cleanup_cfg;
2992 ret = TODO_update_ssa;
2993 initialize_parameter_reductions ();
2995 statistics_counter_event (cfun, "Scalar replacements created",
2996 sra_stats.replacements);
2997 statistics_counter_event (cfun, "Modified expressions", sra_stats.exprs);
2998 statistics_counter_event (cfun, "Subtree copy stmts",
2999 sra_stats.subtree_copies);
3000 statistics_counter_event (cfun, "Subreplacement stmts",
3001 sra_stats.subreplacements);
3002 statistics_counter_event (cfun, "Deleted stmts", sra_stats.deleted);
3003 statistics_counter_event (cfun, "Separate LHS and RHS handling",
3004 sra_stats.separate_lhs_rhs_handling);
3007 sra_deinitialize ();
3011 /* Perform early intraprocedural SRA. */
3013 early_intra_sra (void)
3015 sra_mode = SRA_MODE_EARLY_INTRA;
3016 return perform_intra_sra ();
3019 /* Perform "late" intraprocedural SRA. */
3021 late_intra_sra (void)
3023 sra_mode = SRA_MODE_INTRA;
3024 return perform_intra_sra ();
3029 gate_intra_sra (void)
3031 return flag_tree_sra != 0 && dbg_cnt (tree_sra);
3035 struct gimple_opt_pass pass_sra_early =
3040 gate_intra_sra, /* gate */
3041 early_intra_sra, /* execute */
3044 0, /* static_pass_number */
3045 TV_TREE_SRA, /* tv_id */
3046 PROP_cfg | PROP_ssa, /* properties_required */
3047 0, /* properties_provided */
3048 0, /* properties_destroyed */
3049 0, /* todo_flags_start */
3053 | TODO_verify_ssa /* todo_flags_finish */
3057 struct gimple_opt_pass pass_sra =
3062 gate_intra_sra, /* gate */
3063 late_intra_sra, /* execute */
3066 0, /* static_pass_number */
3067 TV_TREE_SRA, /* tv_id */
3068 PROP_cfg | PROP_ssa, /* properties_required */
3069 0, /* properties_provided */
3070 0, /* properties_destroyed */
3071 TODO_update_address_taken, /* todo_flags_start */
3075 | TODO_verify_ssa /* todo_flags_finish */
3080 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3084 is_unused_scalar_param (tree parm)
3087 return (is_gimple_reg (parm)
3088 && (!(name = gimple_default_def (cfun, parm))
3089 || has_zero_uses (name)));
3092 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3093 examine whether there are any direct or otherwise infeasible ones. If so,
3094 return true, otherwise return false. PARM must be a gimple register with a
3095 non-NULL default definition. */
3098 ptr_parm_has_direct_uses (tree parm)
3100 imm_use_iterator ui;
3102 tree name = gimple_default_def (cfun, parm);
3105 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
3108 use_operand_p use_p;
3110 if (is_gimple_debug (stmt))
3113 /* Valid uses include dereferences on the lhs and the rhs. */
3114 if (gimple_has_lhs (stmt))
3116 tree lhs = gimple_get_lhs (stmt);
3117 while (handled_component_p (lhs))
3118 lhs = TREE_OPERAND (lhs, 0);
3119 if (TREE_CODE (lhs) == MEM_REF
3120 && TREE_OPERAND (lhs, 0) == name
3121 && integer_zerop (TREE_OPERAND (lhs, 1))
3122 && types_compatible_p (TREE_TYPE (lhs),
3123 TREE_TYPE (TREE_TYPE (name))))
3126 if (gimple_assign_single_p (stmt))
3128 tree rhs = gimple_assign_rhs1 (stmt);
3129 while (handled_component_p (rhs))
3130 rhs = TREE_OPERAND (rhs, 0);
3131 if (TREE_CODE (rhs) == MEM_REF
3132 && TREE_OPERAND (rhs, 0) == name
3133 && integer_zerop (TREE_OPERAND (rhs, 1))
3134 && types_compatible_p (TREE_TYPE (rhs),
3135 TREE_TYPE (TREE_TYPE (name))))
3138 else if (is_gimple_call (stmt))
3141 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3143 tree arg = gimple_call_arg (stmt, i);
3144 while (handled_component_p (arg))
3145 arg = TREE_OPERAND (arg, 0);
3146 if (TREE_CODE (arg) == MEM_REF
3147 && TREE_OPERAND (arg, 0) == name
3148 && integer_zerop (TREE_OPERAND (arg, 1))
3149 && types_compatible_p (TREE_TYPE (arg),
3150 TREE_TYPE (TREE_TYPE (name))))
3155 /* If the number of valid uses does not match the number of
3156 uses in this stmt there is an unhandled use. */
3157 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
3164 BREAK_FROM_IMM_USE_STMT (ui);
3170 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3171 them in candidate_bitmap. Note that these do not necessarily include
3172 parameter which are unused and thus can be removed. Return true iff any
3173 such candidate has been found. */
3176 find_param_candidates (void)
3182 for (parm = DECL_ARGUMENTS (current_function_decl);
3184 parm = DECL_CHAIN (parm))
3186 tree type = TREE_TYPE (parm);
3190 if (TREE_THIS_VOLATILE (parm)
3191 || TREE_ADDRESSABLE (parm)
3192 || (!is_gimple_reg_type (type) && is_va_list_type (type)))
3195 if (is_unused_scalar_param (parm))
3201 if (POINTER_TYPE_P (type))
3203 type = TREE_TYPE (type);
3205 if (TREE_CODE (type) == FUNCTION_TYPE
3206 || TYPE_VOLATILE (type)
3207 || (TREE_CODE (type) == ARRAY_TYPE
3208 && TYPE_NONALIASED_COMPONENT (type))
3209 || !is_gimple_reg (parm)
3210 || is_va_list_type (type)
3211 || ptr_parm_has_direct_uses (parm))
3214 else if (!AGGREGATE_TYPE_P (type))
3217 if (!COMPLETE_TYPE_P (type)
3218 || !host_integerp (TYPE_SIZE (type), 1)
3219 || tree_low_cst (TYPE_SIZE (type), 1) == 0
3220 || (AGGREGATE_TYPE_P (type)
3221 && type_internals_preclude_sra_p (type)))
3224 bitmap_set_bit (candidate_bitmap, DECL_UID (parm));
3226 if (dump_file && (dump_flags & TDF_DETAILS))
3228 fprintf (dump_file, "Candidate (%d): ", DECL_UID (parm));
3229 print_generic_expr (dump_file, parm, 0);
3230 fprintf (dump_file, "\n");
3234 func_param_count = count;
3238 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3242 mark_maybe_modified (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef ATTRIBUTE_UNUSED,
3245 struct access *repr = (struct access *) data;
3247 repr->grp_maybe_modified = 1;
3251 /* Analyze what representatives (in linked lists accessible from
3252 REPRESENTATIVES) can be modified by side effects of statements in the
3253 current function. */
3256 analyze_modified_params (VEC (access_p, heap) *representatives)
3260 for (i = 0; i < func_param_count; i++)
3262 struct access *repr;
3264 for (repr = VEC_index (access_p, representatives, i);
3266 repr = repr->next_grp)
3268 struct access *access;
3272 if (no_accesses_p (repr))
3274 if (!POINTER_TYPE_P (TREE_TYPE (repr->base))
3275 || repr->grp_maybe_modified)
3278 ao_ref_init (&ar, repr->expr);
3279 visited = BITMAP_ALLOC (NULL);
3280 for (access = repr; access; access = access->next_sibling)
3282 /* All accesses are read ones, otherwise grp_maybe_modified would
3283 be trivially set. */
3284 walk_aliased_vdefs (&ar, gimple_vuse (access->stmt),
3285 mark_maybe_modified, repr, &visited);
3286 if (repr->grp_maybe_modified)
3289 BITMAP_FREE (visited);
3294 /* Propagate distances in bb_dereferences in the opposite direction than the
3295 control flow edges, in each step storing the maximum of the current value
3296 and the minimum of all successors. These steps are repeated until the table
3297 stabilizes. Note that BBs which might terminate the functions (according to
3298 final_bbs bitmap) never updated in this way. */
3301 propagate_dereference_distances (void)
3303 VEC (basic_block, heap) *queue;
3306 queue = VEC_alloc (basic_block, heap, last_basic_block_for_function (cfun));
3307 VEC_quick_push (basic_block, queue, ENTRY_BLOCK_PTR);
3310 VEC_quick_push (basic_block, queue, bb);
3314 while (!VEC_empty (basic_block, queue))
3318 bool change = false;
3321 bb = VEC_pop (basic_block, queue);
3324 if (bitmap_bit_p (final_bbs, bb->index))
3327 for (i = 0; i < func_param_count; i++)
3329 int idx = bb->index * func_param_count + i;
3331 HOST_WIDE_INT inh = 0;
3333 FOR_EACH_EDGE (e, ei, bb->succs)
3335 int succ_idx = e->dest->index * func_param_count + i;
3337 if (e->src == EXIT_BLOCK_PTR)
3343 inh = bb_dereferences [succ_idx];
3345 else if (bb_dereferences [succ_idx] < inh)
3346 inh = bb_dereferences [succ_idx];
3349 if (!first && bb_dereferences[idx] < inh)
3351 bb_dereferences[idx] = inh;
3356 if (change && !bitmap_bit_p (final_bbs, bb->index))
3357 FOR_EACH_EDGE (e, ei, bb->preds)
3362 e->src->aux = e->src;
3363 VEC_quick_push (basic_block, queue, e->src);
3367 VEC_free (basic_block, heap, queue);
3370 /* Dump a dereferences TABLE with heading STR to file F. */
3373 dump_dereferences_table (FILE *f, const char *str, HOST_WIDE_INT *table)
3377 fprintf (dump_file, str);
3378 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
3380 fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index));
3381 if (bb != EXIT_BLOCK_PTR)
3384 for (i = 0; i < func_param_count; i++)
3386 int idx = bb->index * func_param_count + i;
3387 fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", table[idx]);
3392 fprintf (dump_file, "\n");
3395 /* Determine what (parts of) parameters passed by reference that are not
3396 assigned to are not certainly dereferenced in this function and thus the
3397 dereferencing cannot be safely moved to the caller without potentially
3398 introducing a segfault. Mark such REPRESENTATIVES as
3399 grp_not_necessarilly_dereferenced.
3401 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3402 part is calculated rather than simple booleans are calculated for each
3403 pointer parameter to handle cases when only a fraction of the whole
3404 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3407 The maximum dereference distances for each pointer parameter and BB are
3408 already stored in bb_dereference. This routine simply propagates these
3409 values upwards by propagate_dereference_distances and then compares the
3410 distances of individual parameters in the ENTRY BB to the equivalent
3411 distances of each representative of a (fraction of a) parameter. */
3414 analyze_caller_dereference_legality (VEC (access_p, heap) *representatives)
3418 if (dump_file && (dump_flags & TDF_DETAILS))
3419 dump_dereferences_table (dump_file,
3420 "Dereference table before propagation:\n",
3423 propagate_dereference_distances ();
3425 if (dump_file && (dump_flags & TDF_DETAILS))
3426 dump_dereferences_table (dump_file,
3427 "Dereference table after propagation:\n",
3430 for (i = 0; i < func_param_count; i++)
3432 struct access *repr = VEC_index (access_p, representatives, i);
3433 int idx = ENTRY_BLOCK_PTR->index * func_param_count + i;
3435 if (!repr || no_accesses_p (repr))
3440 if ((repr->offset + repr->size) > bb_dereferences[idx])
3441 repr->grp_not_necessarilly_dereferenced = 1;
3442 repr = repr->next_grp;
3448 /* Return the representative access for the parameter declaration PARM if it is
3449 a scalar passed by reference which is not written to and the pointer value
3450 is not used directly. Thus, if it is legal to dereference it in the caller
3451 and we can rule out modifications through aliases, such parameter should be
3452 turned into one passed by value. Return NULL otherwise. */
3454 static struct access *
3455 unmodified_by_ref_scalar_representative (tree parm)
3457 int i, access_count;
3458 struct access *repr;
3459 VEC (access_p, heap) *access_vec;
3461 access_vec = get_base_access_vector (parm);
3462 gcc_assert (access_vec);
3463 repr = VEC_index (access_p, access_vec, 0);
3466 repr->group_representative = repr;
3468 access_count = VEC_length (access_p, access_vec);
3469 for (i = 1; i < access_count; i++)
3471 struct access *access = VEC_index (access_p, access_vec, i);
3474 access->group_representative = repr;
3475 access->next_sibling = repr->next_sibling;
3476 repr->next_sibling = access;
3480 repr->grp_scalar_ptr = 1;
3484 /* Return true iff this access precludes IPA-SRA of the parameter it is
3488 access_precludes_ipa_sra_p (struct access *access)
3490 /* Avoid issues such as the second simple testcase in PR 42025. The problem
3491 is incompatible assign in a call statement (and possibly even in asm
3492 statements). This can be relaxed by using a new temporary but only for
3493 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
3494 intraprocedural SRA we deal with this by keeping the old aggregate around,
3495 something we cannot do in IPA-SRA.) */
3497 && (is_gimple_call (access->stmt)
3498 || gimple_code (access->stmt) == GIMPLE_ASM))
3505 /* Sort collected accesses for parameter PARM, identify representatives for
3506 each accessed region and link them together. Return NULL if there are
3507 different but overlapping accesses, return the special ptr value meaning
3508 there are no accesses for this parameter if that is the case and return the
3509 first representative otherwise. Set *RO_GRP if there is a group of accesses
3510 with only read (i.e. no write) accesses. */
3512 static struct access *
3513 splice_param_accesses (tree parm, bool *ro_grp)
3515 int i, j, access_count, group_count;
3516 int agg_size, total_size = 0;
3517 struct access *access, *res, **prev_acc_ptr = &res;
3518 VEC (access_p, heap) *access_vec;
3520 access_vec = get_base_access_vector (parm);
3522 return &no_accesses_representant;
3523 access_count = VEC_length (access_p, access_vec);
3525 VEC_qsort (access_p, access_vec, compare_access_positions);
3530 while (i < access_count)
3533 access = VEC_index (access_p, access_vec, i);
3534 modification = access->write;
3535 if (access_precludes_ipa_sra_p (access))
3538 /* Access is about to become group representative unless we find some
3539 nasty overlap which would preclude us from breaking this parameter
3543 while (j < access_count)
3545 struct access *ac2 = VEC_index (access_p, access_vec, j);
3546 if (ac2->offset != access->offset)
3548 /* All or nothing law for parameters. */
3549 if (access->offset + access->size > ac2->offset)
3554 else if (ac2->size != access->size)
3557 if (access_precludes_ipa_sra_p (ac2))
3560 modification |= ac2->write;
3561 ac2->group_representative = access;
3562 ac2->next_sibling = access->next_sibling;
3563 access->next_sibling = ac2;
3568 access->grp_maybe_modified = modification;
3571 *prev_acc_ptr = access;
3572 prev_acc_ptr = &access->next_grp;
3573 total_size += access->size;
3577 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3578 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3580 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3581 if (total_size >= agg_size)
3584 gcc_assert (group_count > 0);
3588 /* Decide whether parameters with representative accesses given by REPR should
3589 be reduced into components. */
3592 decide_one_param_reduction (struct access *repr)
3594 int total_size, cur_parm_size, agg_size, new_param_count, parm_size_limit;
3599 cur_parm_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3600 gcc_assert (cur_parm_size > 0);
3602 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3605 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3610 agg_size = cur_parm_size;
3616 fprintf (dump_file, "Evaluating PARAM group sizes for ");
3617 print_generic_expr (dump_file, parm, 0);
3618 fprintf (dump_file, " (UID: %u): \n", DECL_UID (parm));
3619 for (acc = repr; acc; acc = acc->next_grp)
3620 dump_access (dump_file, acc, true);
3624 new_param_count = 0;
3626 for (; repr; repr = repr->next_grp)
3628 gcc_assert (parm == repr->base);
3631 if (!by_ref || (!repr->grp_maybe_modified
3632 && !repr->grp_not_necessarilly_dereferenced))
3633 total_size += repr->size;
3635 total_size += cur_parm_size;
3638 gcc_assert (new_param_count > 0);
3640 if (optimize_function_for_size_p (cfun))
3641 parm_size_limit = cur_parm_size;
3643 parm_size_limit = (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR)
3646 if (total_size < agg_size
3647 && total_size <= parm_size_limit)
3650 fprintf (dump_file, " ....will be split into %i components\n",
3652 return new_param_count;
3658 /* The order of the following enums is important, we need to do extra work for
3659 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
3660 enum ipa_splicing_result { NO_GOOD_ACCESS, UNUSED_PARAMS, BY_VAL_ACCESSES,
3661 MODIF_BY_REF_ACCESSES, UNMODIF_BY_REF_ACCESSES };
3663 /* Identify representatives of all accesses to all candidate parameters for
3664 IPA-SRA. Return result based on what representatives have been found. */
3666 static enum ipa_splicing_result
3667 splice_all_param_accesses (VEC (access_p, heap) **representatives)
3669 enum ipa_splicing_result result = NO_GOOD_ACCESS;
3671 struct access *repr;
3673 *representatives = VEC_alloc (access_p, heap, func_param_count);
3675 for (parm = DECL_ARGUMENTS (current_function_decl);
3677 parm = DECL_CHAIN (parm))
3679 if (is_unused_scalar_param (parm))
3681 VEC_quick_push (access_p, *representatives,
3682 &no_accesses_representant);
3683 if (result == NO_GOOD_ACCESS)
3684 result = UNUSED_PARAMS;
3686 else if (POINTER_TYPE_P (TREE_TYPE (parm))
3687 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm)))
3688 && bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3690 repr = unmodified_by_ref_scalar_representative (parm);
3691 VEC_quick_push (access_p, *representatives, repr);
3693 result = UNMODIF_BY_REF_ACCESSES;
3695 else if (bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3697 bool ro_grp = false;
3698 repr = splice_param_accesses (parm, &ro_grp);
3699 VEC_quick_push (access_p, *representatives, repr);
3701 if (repr && !no_accesses_p (repr))
3703 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3706 result = UNMODIF_BY_REF_ACCESSES;
3707 else if (result < MODIF_BY_REF_ACCESSES)
3708 result = MODIF_BY_REF_ACCESSES;
3710 else if (result < BY_VAL_ACCESSES)
3711 result = BY_VAL_ACCESSES;
3713 else if (no_accesses_p (repr) && (result == NO_GOOD_ACCESS))
3714 result = UNUSED_PARAMS;
3717 VEC_quick_push (access_p, *representatives, NULL);
3720 if (result == NO_GOOD_ACCESS)
3722 VEC_free (access_p, heap, *representatives);
3723 *representatives = NULL;
3724 return NO_GOOD_ACCESS;
3730 /* Return the index of BASE in PARMS. Abort if it is not found. */
3733 get_param_index (tree base, VEC(tree, heap) *parms)
3737 len = VEC_length (tree, parms);
3738 for (i = 0; i < len; i++)
3739 if (VEC_index (tree, parms, i) == base)
3744 /* Convert the decisions made at the representative level into compact
3745 parameter adjustments. REPRESENTATIVES are pointers to first
3746 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
3747 final number of adjustments. */
3749 static ipa_parm_adjustment_vec
3750 turn_representatives_into_adjustments (VEC (access_p, heap) *representatives,
3751 int adjustments_count)
3753 VEC (tree, heap) *parms;
3754 ipa_parm_adjustment_vec adjustments;
3758 gcc_assert (adjustments_count > 0);
3759 parms = ipa_get_vector_of_formal_parms (current_function_decl);
3760 adjustments = VEC_alloc (ipa_parm_adjustment_t, heap, adjustments_count);
3761 parm = DECL_ARGUMENTS (current_function_decl);
3762 for (i = 0; i < func_param_count; i++, parm = DECL_CHAIN (parm))
3764 struct access *repr = VEC_index (access_p, representatives, i);
3766 if (!repr || no_accesses_p (repr))
3768 struct ipa_parm_adjustment *adj;
3770 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
3771 memset (adj, 0, sizeof (*adj));
3772 adj->base_index = get_param_index (parm, parms);
3775 adj->copy_param = 1;
3777 adj->remove_param = 1;
3781 struct ipa_parm_adjustment *adj;
3782 int index = get_param_index (parm, parms);
3784 for (; repr; repr = repr->next_grp)
3786 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
3787 memset (adj, 0, sizeof (*adj));
3788 gcc_assert (repr->base == parm);
3789 adj->base_index = index;
3790 adj->base = repr->base;
3791 adj->type = repr->type;
3792 adj->offset = repr->offset;
3793 adj->by_ref = (POINTER_TYPE_P (TREE_TYPE (repr->base))
3794 && (repr->grp_maybe_modified
3795 || repr->grp_not_necessarilly_dereferenced));
3800 VEC_free (tree, heap, parms);
3804 /* Analyze the collected accesses and produce a plan what to do with the
3805 parameters in the form of adjustments, NULL meaning nothing. */
3807 static ipa_parm_adjustment_vec
3808 analyze_all_param_acesses (void)
3810 enum ipa_splicing_result repr_state;
3811 bool proceed = false;
3812 int i, adjustments_count = 0;
3813 VEC (access_p, heap) *representatives;
3814 ipa_parm_adjustment_vec adjustments;
3816 repr_state = splice_all_param_accesses (&representatives);
3817 if (repr_state == NO_GOOD_ACCESS)
3820 /* If there are any parameters passed by reference which are not modified
3821 directly, we need to check whether they can be modified indirectly. */
3822 if (repr_state == UNMODIF_BY_REF_ACCESSES)
3824 analyze_caller_dereference_legality (representatives);
3825 analyze_modified_params (representatives);
3828 for (i = 0; i < func_param_count; i++)
3830 struct access *repr = VEC_index (access_p, representatives, i);
3832 if (repr && !no_accesses_p (repr))
3834 if (repr->grp_scalar_ptr)
3836 adjustments_count++;
3837 if (repr->grp_not_necessarilly_dereferenced
3838 || repr->grp_maybe_modified)
3839 VEC_replace (access_p, representatives, i, NULL);
3843 sra_stats.scalar_by_ref_to_by_val++;
3848 int new_components = decide_one_param_reduction (repr);
3850 if (new_components == 0)
3852 VEC_replace (access_p, representatives, i, NULL);
3853 adjustments_count++;
3857 adjustments_count += new_components;
3858 sra_stats.aggregate_params_reduced++;
3859 sra_stats.param_reductions_created += new_components;
3866 if (no_accesses_p (repr))
3869 sra_stats.deleted_unused_parameters++;
3871 adjustments_count++;
3875 if (!proceed && dump_file)
3876 fprintf (dump_file, "NOT proceeding to change params.\n");
3879 adjustments = turn_representatives_into_adjustments (representatives,
3884 VEC_free (access_p, heap, representatives);
3888 /* If a parameter replacement identified by ADJ does not yet exist in the form
3889 of declaration, create it and record it, otherwise return the previously
3893 get_replaced_param_substitute (struct ipa_parm_adjustment *adj)
3896 if (!adj->new_ssa_base)
3898 char *pretty_name = make_fancy_name (adj->base);
3900 repl = create_tmp_reg (TREE_TYPE (adj->base), "ISR");
3901 DECL_NAME (repl) = get_identifier (pretty_name);
3902 obstack_free (&name_obstack, pretty_name);
3905 add_referenced_var (repl);
3906 adj->new_ssa_base = repl;
3909 repl = adj->new_ssa_base;
3913 /* Find the first adjustment for a particular parameter BASE in a vector of
3914 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
3917 static struct ipa_parm_adjustment *
3918 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments, tree base)
3922 len = VEC_length (ipa_parm_adjustment_t, adjustments);
3923 for (i = 0; i < len; i++)
3925 struct ipa_parm_adjustment *adj;
3927 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
3928 if (!adj->copy_param && adj->base == base)
3935 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
3936 removed because its value is not used, replace the SSA_NAME with a one
3937 relating to a created VAR_DECL together all of its uses and return true.
3938 ADJUSTMENTS is a pointer to an adjustments vector. */
3941 replace_removed_params_ssa_names (gimple stmt,
3942 ipa_parm_adjustment_vec adjustments)
3944 struct ipa_parm_adjustment *adj;
3945 tree lhs, decl, repl, name;
3947 if (gimple_code (stmt) == GIMPLE_PHI)
3948 lhs = gimple_phi_result (stmt);
3949 else if (is_gimple_assign (stmt))
3950 lhs = gimple_assign_lhs (stmt);
3951 else if (is_gimple_call (stmt))
3952 lhs = gimple_call_lhs (stmt);
3956 if (TREE_CODE (lhs) != SSA_NAME)
3958 decl = SSA_NAME_VAR (lhs);
3959 if (TREE_CODE (decl) != PARM_DECL)
3962 adj = get_adjustment_for_base (adjustments, decl);
3966 repl = get_replaced_param_substitute (adj);
3967 name = make_ssa_name (repl, stmt);
3971 fprintf (dump_file, "replacing an SSA name of a removed param ");
3972 print_generic_expr (dump_file, lhs, 0);
3973 fprintf (dump_file, " with ");
3974 print_generic_expr (dump_file, name, 0);
3975 fprintf (dump_file, "\n");
3978 if (is_gimple_assign (stmt))
3979 gimple_assign_set_lhs (stmt, name);
3980 else if (is_gimple_call (stmt))
3981 gimple_call_set_lhs (stmt, name);
3983 gimple_phi_set_result (stmt, name);
3985 replace_uses_by (lhs, name);
3986 release_ssa_name (lhs);
3990 /* If the expression *EXPR should be replaced by a reduction of a parameter, do
3991 so. ADJUSTMENTS is a pointer to a vector of adjustments. CONVERT
3992 specifies whether the function should care about type incompatibility the
3993 current and new expressions. If it is false, the function will leave
3994 incompatibility issues to the caller. Return true iff the expression
3998 sra_ipa_modify_expr (tree *expr, bool convert,
3999 ipa_parm_adjustment_vec adjustments)
4002 struct ipa_parm_adjustment *adj, *cand = NULL;
4003 HOST_WIDE_INT offset, size, max_size;
4006 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4008 if (TREE_CODE (*expr) == BIT_FIELD_REF
4009 || TREE_CODE (*expr) == IMAGPART_EXPR
4010 || TREE_CODE (*expr) == REALPART_EXPR)
4012 expr = &TREE_OPERAND (*expr, 0);
4016 base = get_ref_base_and_extent (*expr, &offset, &size, &max_size);
4017 if (!base || size == -1 || max_size == -1)
4020 if (TREE_CODE (base) == MEM_REF)
4022 offset += mem_ref_offset (base).low * BITS_PER_UNIT;
4023 base = TREE_OPERAND (base, 0);
4026 base = get_ssa_base_param (base);
4027 if (!base || TREE_CODE (base) != PARM_DECL)
4030 for (i = 0; i < len; i++)
4032 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4034 if (adj->base == base &&
4035 (adj->offset == offset || adj->remove_param))
4041 if (!cand || cand->copy_param || cand->remove_param)
4045 src = build_simple_mem_ref (cand->reduction);
4047 src = cand->reduction;
4049 if (dump_file && (dump_flags & TDF_DETAILS))
4051 fprintf (dump_file, "About to replace expr ");
4052 print_generic_expr (dump_file, *expr, 0);
4053 fprintf (dump_file, " with ");
4054 print_generic_expr (dump_file, src, 0);
4055 fprintf (dump_file, "\n");
4058 if (convert && !useless_type_conversion_p (TREE_TYPE (*expr), cand->type))
4060 tree vce = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (*expr), src);
4068 /* If the statement pointed to by STMT_PTR contains any expressions that need
4069 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4070 potential type incompatibilities (GSI is used to accommodate conversion
4071 statements and must point to the statement). Return true iff the statement
4075 sra_ipa_modify_assign (gimple *stmt_ptr, gimple_stmt_iterator *gsi,
4076 ipa_parm_adjustment_vec adjustments)
4078 gimple stmt = *stmt_ptr;
4079 tree *lhs_p, *rhs_p;
4082 if (!gimple_assign_single_p (stmt))
4085 rhs_p = gimple_assign_rhs1_ptr (stmt);
4086 lhs_p = gimple_assign_lhs_ptr (stmt);
4088 any = sra_ipa_modify_expr (rhs_p, false, adjustments);
4089 any |= sra_ipa_modify_expr (lhs_p, false, adjustments);
4092 tree new_rhs = NULL_TREE;
4094 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p), TREE_TYPE (*rhs_p)))
4096 if (TREE_CODE (*rhs_p) == CONSTRUCTOR)
4098 /* V_C_Es of constructors can cause trouble (PR 42714). */
4099 if (is_gimple_reg_type (TREE_TYPE (*lhs_p)))
4100 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
4102 *rhs_p = build_constructor (TREE_TYPE (*lhs_p), 0);
4105 new_rhs = fold_build1_loc (gimple_location (stmt),
4106 VIEW_CONVERT_EXPR, TREE_TYPE (*lhs_p),
4109 else if (REFERENCE_CLASS_P (*rhs_p)
4110 && is_gimple_reg_type (TREE_TYPE (*lhs_p))
4111 && !is_gimple_reg (*lhs_p))
4112 /* This can happen when an assignment in between two single field
4113 structures is turned into an assignment in between two pointers to
4114 scalars (PR 42237). */
4119 tree tmp = force_gimple_operand_gsi (gsi, new_rhs, true, NULL_TREE,
4120 true, GSI_SAME_STMT);
4122 gimple_assign_set_rhs_from_tree (gsi, tmp);
4131 /* Traverse the function body and all modifications as described in
4132 ADJUSTMENTS. Return true iff the CFG has been changed. */
4135 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments)
4137 bool cfg_changed = false;
4142 gimple_stmt_iterator gsi;
4144 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4145 replace_removed_params_ssa_names (gsi_stmt (gsi), adjustments);
4147 gsi = gsi_start_bb (bb);
4148 while (!gsi_end_p (gsi))
4150 gimple stmt = gsi_stmt (gsi);
4151 bool modified = false;
4155 switch (gimple_code (stmt))
4158 t = gimple_return_retval_ptr (stmt);
4159 if (*t != NULL_TREE)
4160 modified |= sra_ipa_modify_expr (t, true, adjustments);
4164 modified |= sra_ipa_modify_assign (&stmt, &gsi, adjustments);
4165 modified |= replace_removed_params_ssa_names (stmt, adjustments);
4169 /* Operands must be processed before the lhs. */
4170 for (i = 0; i < gimple_call_num_args (stmt); i++)
4172 t = gimple_call_arg_ptr (stmt, i);
4173 modified |= sra_ipa_modify_expr (t, true, adjustments);
4176 if (gimple_call_lhs (stmt))
4178 t = gimple_call_lhs_ptr (stmt);
4179 modified |= sra_ipa_modify_expr (t, false, adjustments);
4180 modified |= replace_removed_params_ssa_names (stmt,
4186 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
4188 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
4189 modified |= sra_ipa_modify_expr (t, true, adjustments);
4191 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
4193 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
4194 modified |= sra_ipa_modify_expr (t, false, adjustments);
4205 if (maybe_clean_eh_stmt (stmt)
4206 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
4216 /* Call gimple_debug_bind_reset_value on all debug statements describing
4217 gimple register parameters that are being removed or replaced. */
4220 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments)
4224 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4225 for (i = 0; i < len; i++)
4227 struct ipa_parm_adjustment *adj;
4228 imm_use_iterator ui;
4232 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4233 if (adj->copy_param || !is_gimple_reg (adj->base))
4235 name = gimple_default_def (cfun, adj->base);
4238 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
4240 /* All other users must have been removed by
4241 ipa_sra_modify_function_body. */
4242 gcc_assert (is_gimple_debug (stmt));
4243 gimple_debug_bind_reset_value (stmt);
4249 /* Return true iff all callers have at least as many actual arguments as there
4250 are formal parameters in the current function. */
4253 all_callers_have_enough_arguments_p (struct cgraph_node *node)
4255 struct cgraph_edge *cs;
4256 for (cs = node->callers; cs; cs = cs->next_caller)
4257 if (!callsite_has_enough_arguments_p (cs->call_stmt))
4264 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4267 convert_callers (struct cgraph_node *node, tree old_decl,
4268 ipa_parm_adjustment_vec adjustments)
4270 tree old_cur_fndecl = current_function_decl;
4271 struct cgraph_edge *cs;
4272 basic_block this_block;
4273 bitmap recomputed_callers = BITMAP_ALLOC (NULL);
4275 for (cs = node->callers; cs; cs = cs->next_caller)
4277 current_function_decl = cs->caller->decl;
4278 push_cfun (DECL_STRUCT_FUNCTION (cs->caller->decl));
4281 fprintf (dump_file, "Adjusting call (%i -> %i) %s -> %s\n",
4282 cs->caller->uid, cs->callee->uid,
4283 cgraph_node_name (cs->caller),
4284 cgraph_node_name (cs->callee));
4286 ipa_modify_call_arguments (cs, cs->call_stmt, adjustments);
4291 for (cs = node->callers; cs; cs = cs->next_caller)
4292 if (bitmap_set_bit (recomputed_callers, cs->caller->uid))
4293 compute_inline_parameters (cs->caller);
4294 BITMAP_FREE (recomputed_callers);
4296 current_function_decl = old_cur_fndecl;
4298 if (!encountered_recursive_call)
4301 FOR_EACH_BB (this_block)
4303 gimple_stmt_iterator gsi;
4305 for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
4307 gimple stmt = gsi_stmt (gsi);
4309 if (gimple_code (stmt) != GIMPLE_CALL)
4311 call_fndecl = gimple_call_fndecl (stmt);
4312 if (call_fndecl == old_decl)
4315 fprintf (dump_file, "Adjusting recursive call");
4316 gimple_call_set_fndecl (stmt, node->decl);
4317 ipa_modify_call_arguments (NULL, stmt, adjustments);
4325 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4326 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4329 modify_function (struct cgraph_node *node, ipa_parm_adjustment_vec adjustments)
4331 struct cgraph_node *new_node;
4332 struct cgraph_edge *cs;
4334 VEC (cgraph_edge_p, heap) * redirect_callers;
4338 for (cs = node->callers; cs != NULL; cs = cs->next_caller)
4340 redirect_callers = VEC_alloc (cgraph_edge_p, heap, node_callers);
4341 for (cs = node->callers; cs != NULL; cs = cs->next_caller)
4342 VEC_quick_push (cgraph_edge_p, redirect_callers, cs);
4344 rebuild_cgraph_edges ();
4346 current_function_decl = NULL_TREE;
4348 new_node = cgraph_function_versioning (node, redirect_callers, NULL, NULL,
4349 NULL, NULL, "isra");
4350 current_function_decl = new_node->decl;
4351 push_cfun (DECL_STRUCT_FUNCTION (new_node->decl));
4353 ipa_modify_formal_parameters (current_function_decl, adjustments, "ISRA");
4354 cfg_changed = ipa_sra_modify_function_body (adjustments);
4355 sra_ipa_reset_debug_stmts (adjustments);
4356 convert_callers (new_node, node->decl, adjustments);
4357 cgraph_make_node_local (new_node);
4361 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4362 attributes, return true otherwise. NODE is the cgraph node of the current
4366 ipa_sra_preliminary_function_checks (struct cgraph_node *node)
4368 if (!cgraph_node_can_be_local_p (node))
4371 fprintf (dump_file, "Function not local to this compilation unit.\n");
4375 if (!tree_versionable_function_p (node->decl))
4378 fprintf (dump_file, "Function is not versionable.\n");
4382 if (DECL_VIRTUAL_P (current_function_decl))
4385 fprintf (dump_file, "Function is a virtual method.\n");
4389 if ((DECL_COMDAT (node->decl) || DECL_EXTERNAL (node->decl))
4390 && node->global.size >= MAX_INLINE_INSNS_AUTO)
4393 fprintf (dump_file, "Function too big to be made truly local.\n");
4401 "Function has no callers in this compilation unit.\n");
4408 fprintf (dump_file, "Function uses stdarg. \n");
4412 if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl)))
4418 /* Perform early interprocedural SRA. */
4421 ipa_early_sra (void)
4423 struct cgraph_node *node = cgraph_node (current_function_decl);
4424 ipa_parm_adjustment_vec adjustments;
4427 if (!ipa_sra_preliminary_function_checks (node))
4431 sra_mode = SRA_MODE_EARLY_IPA;
4433 if (!find_param_candidates ())
4436 fprintf (dump_file, "Function has no IPA-SRA candidates.\n");
4440 if (!all_callers_have_enough_arguments_p (node))
4443 fprintf (dump_file, "There are callers with insufficient number of "
4448 bb_dereferences = XCNEWVEC (HOST_WIDE_INT,
4450 * last_basic_block_for_function (cfun));
4451 final_bbs = BITMAP_ALLOC (NULL);
4454 if (encountered_apply_args)
4457 fprintf (dump_file, "Function calls __builtin_apply_args().\n");
4461 if (encountered_unchangable_recursive_call)
4464 fprintf (dump_file, "Function calls itself with insufficient "
4465 "number of arguments.\n");
4469 adjustments = analyze_all_param_acesses ();
4473 ipa_dump_param_adjustments (dump_file, adjustments, current_function_decl);
4475 if (modify_function (node, adjustments))
4476 ret = TODO_update_ssa | TODO_cleanup_cfg;
4478 ret = TODO_update_ssa;
4479 VEC_free (ipa_parm_adjustment_t, heap, adjustments);
4481 statistics_counter_event (cfun, "Unused parameters deleted",
4482 sra_stats.deleted_unused_parameters);
4483 statistics_counter_event (cfun, "Scalar parameters converted to by-value",
4484 sra_stats.scalar_by_ref_to_by_val);
4485 statistics_counter_event (cfun, "Aggregate parameters broken up",
4486 sra_stats.aggregate_params_reduced);
4487 statistics_counter_event (cfun, "Aggregate parameter components created",
4488 sra_stats.param_reductions_created);
4491 BITMAP_FREE (final_bbs);
4492 free (bb_dereferences);
4494 sra_deinitialize ();
4498 /* Return if early ipa sra shall be performed. */
4500 ipa_early_sra_gate (void)
4502 return flag_ipa_sra && dbg_cnt (eipa_sra);
4505 struct gimple_opt_pass pass_early_ipa_sra =
4509 "eipa_sra", /* name */
4510 ipa_early_sra_gate, /* gate */
4511 ipa_early_sra, /* execute */
4514 0, /* static_pass_number */
4515 TV_IPA_SRA, /* tv_id */
4516 0, /* properties_required */
4517 0, /* properties_provided */
4518 0, /* properties_destroyed */
4519 0, /* todo_flags_start */
4520 TODO_dump_func | TODO_dump_cgraph /* todo_flags_finish */