1 /* Scalar Replacement of Aggregates (SRA) converts some structure
2 references into scalar references, exposing them to the scalar
4 Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
5 Contributed by Martin Jambor <mjambor@suse.cz>
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* This file implements Scalar Reduction of Aggregates (SRA). SRA is run
24 twice, once in the early stages of compilation (early SRA) and once in the
25 late stages (late SRA). The aim of both is to turn references to scalar
26 parts of aggregates into uses of independent scalar variables.
28 The two passes are nearly identical, the only difference is that early SRA
29 does not scalarize unions which are used as the result in a GIMPLE_RETURN
30 statement because together with inlining this can lead to weird type
33 Both passes operate in four stages:
35 1. The declarations that have properties which make them candidates for
36 scalarization are identified in function find_var_candidates(). The
37 candidates are stored in candidate_bitmap.
39 2. The function body is scanned. In the process, declarations which are
40 used in a manner that prevent their scalarization are removed from the
41 candidate bitmap. More importantly, for every access into an aggregate,
42 an access structure (struct access) is created by create_access() and
43 stored in a vector associated with the aggregate. Among other
44 information, the aggregate declaration, the offset and size of the access
45 and its type are stored in the structure.
47 On a related note, assign_link structures are created for every assign
48 statement between candidate aggregates and attached to the related
51 3. The vectors of accesses are analyzed. They are first sorted according to
52 their offset and size and then scanned for partially overlapping accesses
53 (i.e. those which overlap but one is not entirely within another). Such
54 an access disqualifies the whole aggregate from being scalarized.
56 If there is no such inhibiting overlap, a representative access structure
57 is chosen for every unique combination of offset and size. Afterwards,
58 the pass builds a set of trees from these structures, in which children
59 of an access are within their parent (in terms of offset and size).
61 Then accesses are propagated whenever possible (i.e. in cases when it
62 does not create a partially overlapping access) across assign_links from
63 the right hand side to the left hand side.
65 Then the set of trees for each declaration is traversed again and those
66 accesses which should be replaced by a scalar are identified.
68 4. The function is traversed again, and for every reference into an
69 aggregate that has some component which is about to be scalarized,
70 statements are amended and new statements are created as necessary.
71 Finally, if a parameter got scalarized, the scalar replacements are
72 initialized with values from respective parameter aggregates. */
76 #include "coretypes.h"
77 #include "alloc-pool.h"
82 #include "tree-flow.h"
84 #include "tree-pretty-print.h"
85 #include "statistics.h"
86 #include "tree-dump.h"
92 #include "tree-inline.h"
93 #include "gimple-pretty-print.h"
95 /* Enumeration of all aggregate reductions we can do. */
96 enum sra_mode { SRA_MODE_EARLY_IPA, /* early call regularization */
97 SRA_MODE_EARLY_INTRA, /* early intraprocedural SRA */
98 SRA_MODE_INTRA }; /* late intraprocedural SRA */
100 /* Global variable describing which aggregate reduction we are performing at
102 static enum sra_mode sra_mode;
106 /* ACCESS represents each access to an aggregate variable (as a whole or a
107 part). It can also represent a group of accesses that refer to exactly the
108 same fragment of an aggregate (i.e. those that have exactly the same offset
109 and size). Such representatives for a single aggregate, once determined,
110 are linked in a linked list and have the group fields set.
112 Moreover, when doing intraprocedural SRA, a tree is built from those
113 representatives (by the means of first_child and next_sibling pointers), in
114 which all items in a subtree are "within" the root, i.e. their offset is
115 greater or equal to offset of the root and offset+size is smaller or equal
116 to offset+size of the root. Children of an access are sorted by offset.
118 Note that accesses to parts of vector and complex number types always
119 represented by an access to the whole complex number or a vector. It is a
120 duty of the modifying functions to replace them appropriately. */
124 /* Values returned by `get_ref_base_and_extent' for each component reference
125 If EXPR isn't a component reference just set `BASE = EXPR', `OFFSET = 0',
126 `SIZE = TREE_SIZE (TREE_TYPE (expr))'. */
127 HOST_WIDE_INT offset;
131 /* Expression. It is context dependent so do not use it to create new
132 expressions to access the original aggregate. See PR 42154 for a
138 /* The statement this access belongs to. */
141 /* Next group representative for this aggregate. */
142 struct access *next_grp;
144 /* Pointer to the group representative. Pointer to itself if the struct is
145 the representative. */
146 struct access *group_representative;
148 /* If this access has any children (in terms of the definition above), this
149 points to the first one. */
150 struct access *first_child;
152 /* In intraprocedural SRA, pointer to the next sibling in the access tree as
153 described above. In IPA-SRA this is a pointer to the next access
154 belonging to the same group (having the same representative). */
155 struct access *next_sibling;
157 /* Pointers to the first and last element in the linked list of assign
159 struct assign_link *first_link, *last_link;
161 /* Pointer to the next access in the work queue. */
162 struct access *next_queued;
164 /* Replacement variable for this access "region." Never to be accessed
165 directly, always only by the means of get_access_replacement() and only
166 when grp_to_be_replaced flag is set. */
167 tree replacement_decl;
169 /* Is this particular access write access? */
172 /* Is this access an artificial one created to scalarize some record
174 unsigned total_scalarization : 1;
176 /* Is this access an access to a non-addressable field? */
177 unsigned non_addressable : 1;
179 /* Is this access currently in the work queue? */
180 unsigned grp_queued : 1;
182 /* Does this group contain a write access? This flag is propagated down the
184 unsigned grp_write : 1;
186 /* Does this group contain a read access? This flag is propagated down the
188 unsigned grp_read : 1;
190 /* Does this group contain a read access that comes from an assignment
191 statement? This flag is propagated down the access tree. */
192 unsigned grp_assignment_read : 1;
194 /* Does this group contain a write access that comes from an assignment
195 statement? This flag is propagated down the access tree. */
196 unsigned grp_assignment_write : 1;
198 /* Does this group contain a read access through a scalar type? This flag is
199 not propagated in the access tree in any direction. */
200 unsigned grp_scalar_read : 1;
202 /* Does this group contain a write access through a scalar type? This flag
203 is not propagated in the access tree in any direction. */
204 unsigned grp_scalar_write : 1;
206 /* Other passes of the analysis use this bit to make function
207 analyze_access_subtree create scalar replacements for this group if
209 unsigned grp_hint : 1;
211 /* Is the subtree rooted in this access fully covered by scalar
213 unsigned grp_covered : 1;
215 /* If set to true, this access and all below it in an access tree must not be
217 unsigned grp_unscalarizable_region : 1;
219 /* Whether data have been written to parts of the aggregate covered by this
220 access which is not to be scalarized. This flag is propagated up in the
222 unsigned grp_unscalarized_data : 1;
224 /* Does this access and/or group contain a write access through a
226 unsigned grp_partial_lhs : 1;
228 /* Set when a scalar replacement should be created for this variable. We do
229 the decision and creation at different places because create_tmp_var
230 cannot be called from within FOR_EACH_REFERENCED_VAR. */
231 unsigned grp_to_be_replaced : 1;
233 /* Should TREE_NO_WARNING of a replacement be set? */
234 unsigned grp_no_warning : 1;
236 /* Is it possible that the group refers to data which might be (directly or
237 otherwise) modified? */
238 unsigned grp_maybe_modified : 1;
240 /* Set when this is a representative of a pointer to scalar (i.e. by
241 reference) parameter which we consider for turning into a plain scalar
242 (i.e. a by value parameter). */
243 unsigned grp_scalar_ptr : 1;
245 /* Set when we discover that this pointer is not safe to dereference in the
247 unsigned grp_not_necessarilly_dereferenced : 1;
250 typedef struct access *access_p;
252 DEF_VEC_P (access_p);
253 DEF_VEC_ALLOC_P (access_p, heap);
255 /* Alloc pool for allocating access structures. */
256 static alloc_pool access_pool;
258 /* A structure linking lhs and rhs accesses from an aggregate assignment. They
259 are used to propagate subaccesses from rhs to lhs as long as they don't
260 conflict with what is already there. */
263 struct access *lacc, *racc;
264 struct assign_link *next;
267 /* Alloc pool for allocating assign link structures. */
268 static alloc_pool link_pool;
270 /* Base (tree) -> Vector (VEC(access_p,heap) *) map. */
271 static struct pointer_map_t *base_access_vec;
273 /* Bitmap of candidates. */
274 static bitmap candidate_bitmap;
276 /* Bitmap of candidates which we should try to entirely scalarize away and
277 those which cannot be (because they are and need be used as a whole). */
278 static bitmap should_scalarize_away_bitmap, cannot_scalarize_away_bitmap;
280 /* Obstack for creation of fancy names. */
281 static struct obstack name_obstack;
283 /* Head of a linked list of accesses that need to have its subaccesses
284 propagated to their assignment counterparts. */
285 static struct access *work_queue_head;
287 /* Number of parameters of the analyzed function when doing early ipa SRA. */
288 static int func_param_count;
290 /* scan_function sets the following to true if it encounters a call to
291 __builtin_apply_args. */
292 static bool encountered_apply_args;
294 /* Set by scan_function when it finds a recursive call. */
295 static bool encountered_recursive_call;
297 /* Set by scan_function when it finds a recursive call with less actual
298 arguments than formal parameters.. */
299 static bool encountered_unchangable_recursive_call;
301 /* This is a table in which for each basic block and parameter there is a
302 distance (offset + size) in that parameter which is dereferenced and
303 accessed in that BB. */
304 static HOST_WIDE_INT *bb_dereferences;
305 /* Bitmap of BBs that can cause the function to "stop" progressing by
306 returning, throwing externally, looping infinitely or calling a function
307 which might abort etc.. */
308 static bitmap final_bbs;
310 /* Representative of no accesses at all. */
311 static struct access no_accesses_representant;
313 /* Predicate to test the special value. */
316 no_accesses_p (struct access *access)
318 return access == &no_accesses_representant;
321 /* Dump contents of ACCESS to file F in a human friendly way. If GRP is true,
322 representative fields are dumped, otherwise those which only describe the
323 individual access are. */
327 /* Number of processed aggregates is readily available in
328 analyze_all_variable_accesses and so is not stored here. */
330 /* Number of created scalar replacements. */
333 /* Number of times sra_modify_expr or sra_modify_assign themselves changed an
337 /* Number of statements created by generate_subtree_copies. */
340 /* Number of statements created by load_assign_lhs_subreplacements. */
343 /* Number of times sra_modify_assign has deleted a statement. */
346 /* Number of times sra_modify_assign has to deal with subaccesses of LHS and
347 RHS reparately due to type conversions or nonexistent matching
349 int separate_lhs_rhs_handling;
351 /* Number of parameters that were removed because they were unused. */
352 int deleted_unused_parameters;
354 /* Number of scalars passed as parameters by reference that have been
355 converted to be passed by value. */
356 int scalar_by_ref_to_by_val;
358 /* Number of aggregate parameters that were replaced by one or more of their
360 int aggregate_params_reduced;
362 /* Numbber of components created when splitting aggregate parameters. */
363 int param_reductions_created;
367 dump_access (FILE *f, struct access *access, bool grp)
369 fprintf (f, "access { ");
370 fprintf (f, "base = (%d)'", DECL_UID (access->base));
371 print_generic_expr (f, access->base, 0);
372 fprintf (f, "', offset = " HOST_WIDE_INT_PRINT_DEC, access->offset);
373 fprintf (f, ", size = " HOST_WIDE_INT_PRINT_DEC, access->size);
374 fprintf (f, ", expr = ");
375 print_generic_expr (f, access->expr, 0);
376 fprintf (f, ", type = ");
377 print_generic_expr (f, access->type, 0);
379 fprintf (f, ", total_scalarization = %d, grp_read = %d, grp_write = %d, "
380 "grp_assignment_read = %d, grp_assignment_write = %d, "
381 "grp_scalar_read = %d, grp_scalar_write = %d, "
382 "grp_hint = %d, grp_covered = %d, "
383 "grp_unscalarizable_region = %d, grp_unscalarized_data = %d, "
384 "grp_partial_lhs = %d, grp_to_be_replaced = %d, "
385 "grp_maybe_modified = %d, "
386 "grp_not_necessarilly_dereferenced = %d\n",
387 access->total_scalarization, access->grp_read, access->grp_write,
388 access->grp_assignment_read, access->grp_assignment_write,
389 access->grp_scalar_read, access->grp_scalar_write,
390 access->grp_hint, access->grp_covered,
391 access->grp_unscalarizable_region, access->grp_unscalarized_data,
392 access->grp_partial_lhs, access->grp_to_be_replaced,
393 access->grp_maybe_modified,
394 access->grp_not_necessarilly_dereferenced);
396 fprintf (f, ", write = %d, total_scalarization = %d, "
397 "grp_partial_lhs = %d\n",
398 access->write, access->total_scalarization,
399 access->grp_partial_lhs);
402 /* Dump a subtree rooted in ACCESS to file F, indent by LEVEL. */
405 dump_access_tree_1 (FILE *f, struct access *access, int level)
411 for (i = 0; i < level; i++)
412 fputs ("* ", dump_file);
414 dump_access (f, access, true);
416 if (access->first_child)
417 dump_access_tree_1 (f, access->first_child, level + 1);
419 access = access->next_sibling;
424 /* Dump all access trees for a variable, given the pointer to the first root in
428 dump_access_tree (FILE *f, struct access *access)
430 for (; access; access = access->next_grp)
431 dump_access_tree_1 (f, access, 0);
434 /* Return true iff ACC is non-NULL and has subaccesses. */
437 access_has_children_p (struct access *acc)
439 return acc && acc->first_child;
442 /* Return a vector of pointers to accesses for the variable given in BASE or
443 NULL if there is none. */
445 static VEC (access_p, heap) *
446 get_base_access_vector (tree base)
450 slot = pointer_map_contains (base_access_vec, base);
454 return *(VEC (access_p, heap) **) slot;
457 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
458 in ACCESS. Return NULL if it cannot be found. */
460 static struct access *
461 find_access_in_subtree (struct access *access, HOST_WIDE_INT offset,
464 while (access && (access->offset != offset || access->size != size))
466 struct access *child = access->first_child;
468 while (child && (child->offset + child->size <= offset))
469 child = child->next_sibling;
476 /* Return the first group representative for DECL or NULL if none exists. */
478 static struct access *
479 get_first_repr_for_decl (tree base)
481 VEC (access_p, heap) *access_vec;
483 access_vec = get_base_access_vector (base);
487 return VEC_index (access_p, access_vec, 0);
490 /* Find an access representative for the variable BASE and given OFFSET and
491 SIZE. Requires that access trees have already been built. Return NULL if
492 it cannot be found. */
494 static struct access *
495 get_var_base_offset_size_access (tree base, HOST_WIDE_INT offset,
498 struct access *access;
500 access = get_first_repr_for_decl (base);
501 while (access && (access->offset + access->size <= offset))
502 access = access->next_grp;
506 return find_access_in_subtree (access, offset, size);
509 /* Add LINK to the linked list of assign links of RACC. */
511 add_link_to_rhs (struct access *racc, struct assign_link *link)
513 gcc_assert (link->racc == racc);
515 if (!racc->first_link)
517 gcc_assert (!racc->last_link);
518 racc->first_link = link;
521 racc->last_link->next = link;
523 racc->last_link = link;
527 /* Move all link structures in their linked list in OLD_RACC to the linked list
530 relink_to_new_repr (struct access *new_racc, struct access *old_racc)
532 if (!old_racc->first_link)
534 gcc_assert (!old_racc->last_link);
538 if (new_racc->first_link)
540 gcc_assert (!new_racc->last_link->next);
541 gcc_assert (!old_racc->last_link || !old_racc->last_link->next);
543 new_racc->last_link->next = old_racc->first_link;
544 new_racc->last_link = old_racc->last_link;
548 gcc_assert (!new_racc->last_link);
550 new_racc->first_link = old_racc->first_link;
551 new_racc->last_link = old_racc->last_link;
553 old_racc->first_link = old_racc->last_link = NULL;
556 /* Add ACCESS to the work queue (which is actually a stack). */
559 add_access_to_work_queue (struct access *access)
561 if (!access->grp_queued)
563 gcc_assert (!access->next_queued);
564 access->next_queued = work_queue_head;
565 access->grp_queued = 1;
566 work_queue_head = access;
570 /* Pop an access from the work queue, and return it, assuming there is one. */
572 static struct access *
573 pop_access_from_work_queue (void)
575 struct access *access = work_queue_head;
577 work_queue_head = access->next_queued;
578 access->next_queued = NULL;
579 access->grp_queued = 0;
584 /* Allocate necessary structures. */
587 sra_initialize (void)
589 candidate_bitmap = BITMAP_ALLOC (NULL);
590 should_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
591 cannot_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
592 gcc_obstack_init (&name_obstack);
593 access_pool = create_alloc_pool ("SRA accesses", sizeof (struct access), 16);
594 link_pool = create_alloc_pool ("SRA links", sizeof (struct assign_link), 16);
595 base_access_vec = pointer_map_create ();
596 memset (&sra_stats, 0, sizeof (sra_stats));
597 encountered_apply_args = false;
598 encountered_recursive_call = false;
599 encountered_unchangable_recursive_call = false;
602 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
605 delete_base_accesses (const void *key ATTRIBUTE_UNUSED, void **value,
606 void *data ATTRIBUTE_UNUSED)
608 VEC (access_p, heap) *access_vec;
609 access_vec = (VEC (access_p, heap) *) *value;
610 VEC_free (access_p, heap, access_vec);
615 /* Deallocate all general structures. */
618 sra_deinitialize (void)
620 BITMAP_FREE (candidate_bitmap);
621 BITMAP_FREE (should_scalarize_away_bitmap);
622 BITMAP_FREE (cannot_scalarize_away_bitmap);
623 free_alloc_pool (access_pool);
624 free_alloc_pool (link_pool);
625 obstack_free (&name_obstack, NULL);
627 pointer_map_traverse (base_access_vec, delete_base_accesses, NULL);
628 pointer_map_destroy (base_access_vec);
631 /* Remove DECL from candidates for SRA and write REASON to the dump file if
634 disqualify_candidate (tree decl, const char *reason)
636 bitmap_clear_bit (candidate_bitmap, DECL_UID (decl));
638 if (dump_file && (dump_flags & TDF_DETAILS))
640 fprintf (dump_file, "! Disqualifying ");
641 print_generic_expr (dump_file, decl, 0);
642 fprintf (dump_file, " - %s\n", reason);
646 /* Return true iff the type contains a field or an element which does not allow
650 type_internals_preclude_sra_p (tree type)
655 switch (TREE_CODE (type))
659 case QUAL_UNION_TYPE:
660 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
661 if (TREE_CODE (fld) == FIELD_DECL)
663 tree ft = TREE_TYPE (fld);
665 if (TREE_THIS_VOLATILE (fld)
666 || !DECL_FIELD_OFFSET (fld) || !DECL_SIZE (fld)
667 || !host_integerp (DECL_FIELD_OFFSET (fld), 1)
668 || !host_integerp (DECL_SIZE (fld), 1)
669 || (AGGREGATE_TYPE_P (ft)
670 && int_bit_position (fld) % BITS_PER_UNIT != 0))
673 if (AGGREGATE_TYPE_P (ft)
674 && type_internals_preclude_sra_p (ft))
681 et = TREE_TYPE (type);
683 if (AGGREGATE_TYPE_P (et))
684 return type_internals_preclude_sra_p (et);
693 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
694 base variable if it is. Return T if it is not an SSA_NAME. */
697 get_ssa_base_param (tree t)
699 if (TREE_CODE (t) == SSA_NAME)
701 if (SSA_NAME_IS_DEFAULT_DEF (t))
702 return SSA_NAME_VAR (t);
709 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
710 belongs to, unless the BB has already been marked as a potentially
714 mark_parm_dereference (tree base, HOST_WIDE_INT dist, gimple stmt)
716 basic_block bb = gimple_bb (stmt);
717 int idx, parm_index = 0;
720 if (bitmap_bit_p (final_bbs, bb->index))
723 for (parm = DECL_ARGUMENTS (current_function_decl);
724 parm && parm != base;
725 parm = DECL_CHAIN (parm))
728 gcc_assert (parm_index < func_param_count);
730 idx = bb->index * func_param_count + parm_index;
731 if (bb_dereferences[idx] < dist)
732 bb_dereferences[idx] = dist;
735 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
736 the three fields. Also add it to the vector of accesses corresponding to
737 the base. Finally, return the new access. */
739 static struct access *
740 create_access_1 (tree base, HOST_WIDE_INT offset, HOST_WIDE_INT size)
742 VEC (access_p, heap) *vec;
743 struct access *access;
746 access = (struct access *) pool_alloc (access_pool);
747 memset (access, 0, sizeof (struct access));
749 access->offset = offset;
752 slot = pointer_map_contains (base_access_vec, base);
754 vec = (VEC (access_p, heap) *) *slot;
756 vec = VEC_alloc (access_p, heap, 32);
758 VEC_safe_push (access_p, heap, vec, access);
760 *((struct VEC (access_p,heap) **)
761 pointer_map_insert (base_access_vec, base)) = vec;
766 /* Create and insert access for EXPR. Return created access, or NULL if it is
769 static struct access *
770 create_access (tree expr, gimple stmt, bool write)
772 struct access *access;
773 HOST_WIDE_INT offset, size, max_size;
775 bool ptr, unscalarizable_region = false;
777 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
779 if (sra_mode == SRA_MODE_EARLY_IPA
780 && TREE_CODE (base) == MEM_REF)
782 base = get_ssa_base_param (TREE_OPERAND (base, 0));
790 if (!DECL_P (base) || !bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
793 if (sra_mode == SRA_MODE_EARLY_IPA)
795 if (size < 0 || size != max_size)
797 disqualify_candidate (base, "Encountered a variable sized access.");
800 if (TREE_CODE (expr) == COMPONENT_REF
801 && DECL_BIT_FIELD (TREE_OPERAND (expr, 1)))
803 disqualify_candidate (base, "Encountered a bit-field access.");
806 gcc_checking_assert ((offset % BITS_PER_UNIT) == 0);
809 mark_parm_dereference (base, offset + size, stmt);
813 if (size != max_size)
816 unscalarizable_region = true;
820 disqualify_candidate (base, "Encountered an unconstrained access.");
825 access = create_access_1 (base, offset, size);
827 access->type = TREE_TYPE (expr);
828 access->write = write;
829 access->grp_unscalarizable_region = unscalarizable_region;
832 if (TREE_CODE (expr) == COMPONENT_REF
833 && DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1)))
834 access->non_addressable = 1;
840 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
841 register types or (recursively) records with only these two kinds of fields.
842 It also returns false if any of these records contains a bit-field. */
845 type_consists_of_records_p (tree type)
849 if (TREE_CODE (type) != RECORD_TYPE)
852 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
853 if (TREE_CODE (fld) == FIELD_DECL)
855 tree ft = TREE_TYPE (fld);
857 if (DECL_BIT_FIELD (fld))
860 if (!is_gimple_reg_type (ft)
861 && !type_consists_of_records_p (ft))
868 /* Create total_scalarization accesses for all scalar type fields in DECL that
869 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
870 must be the top-most VAR_DECL representing the variable, OFFSET must be the
871 offset of DECL within BASE. REF must be the memory reference expression for
875 completely_scalarize_record (tree base, tree decl, HOST_WIDE_INT offset,
878 tree fld, decl_type = TREE_TYPE (decl);
880 for (fld = TYPE_FIELDS (decl_type); fld; fld = DECL_CHAIN (fld))
881 if (TREE_CODE (fld) == FIELD_DECL)
883 HOST_WIDE_INT pos = offset + int_bit_position (fld);
884 tree ft = TREE_TYPE (fld);
885 tree nref = build3 (COMPONENT_REF, TREE_TYPE (fld), ref, fld,
888 if (is_gimple_reg_type (ft))
890 struct access *access;
893 size = tree_low_cst (DECL_SIZE (fld), 1);
894 access = create_access_1 (base, pos, size);
897 access->total_scalarization = 1;
898 /* Accesses for intraprocedural SRA can have their stmt NULL. */
901 completely_scalarize_record (base, fld, pos, nref);
906 /* Search the given tree for a declaration by skipping handled components and
907 exclude it from the candidates. */
910 disqualify_base_of_expr (tree t, const char *reason)
912 t = get_base_address (t);
914 && sra_mode == SRA_MODE_EARLY_IPA
915 && TREE_CODE (t) == MEM_REF)
916 t = get_ssa_base_param (TREE_OPERAND (t, 0));
919 disqualify_candidate (t, reason);
922 /* Scan expression EXPR and create access structures for all accesses to
923 candidates for scalarization. Return the created access or NULL if none is
926 static struct access *
927 build_access_from_expr_1 (tree expr, gimple stmt, bool write)
929 struct access *ret = NULL;
932 if (TREE_CODE (expr) == BIT_FIELD_REF
933 || TREE_CODE (expr) == IMAGPART_EXPR
934 || TREE_CODE (expr) == REALPART_EXPR)
936 expr = TREE_OPERAND (expr, 0);
942 /* We need to dive through V_C_Es in order to get the size of its parameter
943 and not the result type. Ada produces such statements. We are also
944 capable of handling the topmost V_C_E but not any of those buried in other
945 handled components. */
946 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
947 expr = TREE_OPERAND (expr, 0);
949 if (contains_view_convert_expr_p (expr))
951 disqualify_base_of_expr (expr, "V_C_E under a different handled "
956 switch (TREE_CODE (expr))
959 if (TREE_CODE (TREE_OPERAND (expr, 0)) != ADDR_EXPR
960 && sra_mode != SRA_MODE_EARLY_IPA)
968 case ARRAY_RANGE_REF:
969 ret = create_access (expr, stmt, write);
976 if (write && partial_ref && ret)
977 ret->grp_partial_lhs = 1;
982 /* Scan expression EXPR and create access structures for all accesses to
983 candidates for scalarization. Return true if any access has been inserted.
984 STMT must be the statement from which the expression is taken, WRITE must be
985 true if the expression is a store and false otherwise. */
988 build_access_from_expr (tree expr, gimple stmt, bool write)
990 struct access *access;
992 access = build_access_from_expr_1 (expr, stmt, write);
995 /* This means the aggregate is accesses as a whole in a way other than an
996 assign statement and thus cannot be removed even if we had a scalar
997 replacement for everything. */
998 if (cannot_scalarize_away_bitmap)
999 bitmap_set_bit (cannot_scalarize_away_bitmap, DECL_UID (access->base));
1005 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
1006 modes in which it matters, return true iff they have been disqualified. RHS
1007 may be NULL, in that case ignore it. If we scalarize an aggregate in
1008 intra-SRA we may need to add statements after each statement. This is not
1009 possible if a statement unconditionally has to end the basic block. */
1011 disqualify_ops_if_throwing_stmt (gimple stmt, tree lhs, tree rhs)
1013 if ((sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1014 && (stmt_can_throw_internal (stmt) || stmt_ends_bb_p (stmt)))
1016 disqualify_base_of_expr (lhs, "LHS of a throwing stmt.");
1018 disqualify_base_of_expr (rhs, "RHS of a throwing stmt.");
1024 /* Return true if EXP is a memory reference less aligned than ALIGN. This is
1025 invoked only on strict-alignment targets. */
1028 tree_non_aligned_mem_p (tree exp, unsigned int align)
1030 unsigned int exp_align;
1032 if (TREE_CODE (exp) == VIEW_CONVERT_EXPR)
1033 exp = TREE_OPERAND (exp, 0);
1035 if (TREE_CODE (exp) == SSA_NAME || is_gimple_min_invariant (exp))
1038 /* get_object_alignment will fall back to BITS_PER_UNIT if it cannot
1039 compute an explicit alignment. Pretend that dereferenced pointers
1040 are always aligned on strict-alignment targets. */
1041 exp_align = get_object_alignment (exp, BIGGEST_ALIGNMENT);
1042 if (TREE_CODE (exp) == MEM_REF || TREE_CODE (exp) == TARGET_MEM_REF)
1043 exp_align = MAX (TYPE_ALIGN (TREE_TYPE (exp)), exp_align);
1045 if (exp_align < align)
1051 /* Return true if EXP is a memory reference less aligned than what the access
1052 ACC would require. This is invoked only on strict-alignment targets. */
1055 tree_non_aligned_mem_for_access_p (tree exp, struct access *acc)
1057 unsigned int acc_align;
1059 /* The alignment of the access is that of its expression. However, it may
1060 have been artificially increased, e.g. by a local alignment promotion,
1061 so we cap it to the alignment of the type of the base, on the grounds
1062 that valid sub-accesses cannot be more aligned than that. */
1063 acc_align = get_object_alignment (acc->expr, BIGGEST_ALIGNMENT);
1064 if (acc->base && acc_align > TYPE_ALIGN (TREE_TYPE (acc->base)))
1065 acc_align = TYPE_ALIGN (TREE_TYPE (acc->base));
1067 return tree_non_aligned_mem_p (exp, acc_align);
1070 /* Scan expressions occuring in STMT, create access structures for all accesses
1071 to candidates for scalarization and remove those candidates which occur in
1072 statements or expressions that prevent them from being split apart. Return
1073 true if any access has been inserted. */
1076 build_accesses_from_assign (gimple stmt)
1079 struct access *lacc, *racc;
1081 if (!gimple_assign_single_p (stmt))
1084 lhs = gimple_assign_lhs (stmt);
1085 rhs = gimple_assign_rhs1 (stmt);
1087 if (disqualify_ops_if_throwing_stmt (stmt, lhs, rhs))
1090 racc = build_access_from_expr_1 (rhs, stmt, false);
1091 lacc = build_access_from_expr_1 (lhs, stmt, true);
1095 lacc->grp_assignment_write = 1;
1096 if (STRICT_ALIGNMENT && tree_non_aligned_mem_for_access_p (rhs, lacc))
1097 lacc->grp_unscalarizable_region = 1;
1102 racc->grp_assignment_read = 1;
1103 if (should_scalarize_away_bitmap && !gimple_has_volatile_ops (stmt)
1104 && !is_gimple_reg_type (racc->type))
1105 bitmap_set_bit (should_scalarize_away_bitmap, DECL_UID (racc->base));
1106 if (STRICT_ALIGNMENT && tree_non_aligned_mem_for_access_p (lhs, racc))
1107 racc->grp_unscalarizable_region = 1;
1111 && (sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1112 && !lacc->grp_unscalarizable_region
1113 && !racc->grp_unscalarizable_region
1114 && AGGREGATE_TYPE_P (TREE_TYPE (lhs))
1115 /* FIXME: Turn the following line into an assert after PR 40058 is
1117 && lacc->size == racc->size
1118 && useless_type_conversion_p (lacc->type, racc->type))
1120 struct assign_link *link;
1122 link = (struct assign_link *) pool_alloc (link_pool);
1123 memset (link, 0, sizeof (struct assign_link));
1128 add_link_to_rhs (racc, link);
1131 return lacc || racc;
1134 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1135 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1138 asm_visit_addr (gimple stmt ATTRIBUTE_UNUSED, tree op,
1139 void *data ATTRIBUTE_UNUSED)
1141 op = get_base_address (op);
1144 disqualify_candidate (op, "Non-scalarizable GIMPLE_ASM operand.");
1149 /* Return true iff callsite CALL has at least as many actual arguments as there
1150 are formal parameters of the function currently processed by IPA-SRA. */
1153 callsite_has_enough_arguments_p (gimple call)
1155 return gimple_call_num_args (call) >= (unsigned) func_param_count;
1158 /* Scan function and look for interesting expressions and create access
1159 structures for them. Return true iff any access is created. */
1162 scan_function (void)
1169 gimple_stmt_iterator gsi;
1170 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1172 gimple stmt = gsi_stmt (gsi);
1176 if (final_bbs && stmt_can_throw_external (stmt))
1177 bitmap_set_bit (final_bbs, bb->index);
1178 switch (gimple_code (stmt))
1181 t = gimple_return_retval (stmt);
1183 ret |= build_access_from_expr (t, stmt, false);
1185 bitmap_set_bit (final_bbs, bb->index);
1189 ret |= build_accesses_from_assign (stmt);
1193 for (i = 0; i < gimple_call_num_args (stmt); i++)
1194 ret |= build_access_from_expr (gimple_call_arg (stmt, i),
1197 if (sra_mode == SRA_MODE_EARLY_IPA)
1199 tree dest = gimple_call_fndecl (stmt);
1200 int flags = gimple_call_flags (stmt);
1204 if (DECL_BUILT_IN_CLASS (dest) == BUILT_IN_NORMAL
1205 && DECL_FUNCTION_CODE (dest) == BUILT_IN_APPLY_ARGS)
1206 encountered_apply_args = true;
1207 if (cgraph_get_node (dest)
1208 == cgraph_get_node (current_function_decl))
1210 encountered_recursive_call = true;
1211 if (!callsite_has_enough_arguments_p (stmt))
1212 encountered_unchangable_recursive_call = true;
1217 && (flags & (ECF_CONST | ECF_PURE)) == 0)
1218 bitmap_set_bit (final_bbs, bb->index);
1221 t = gimple_call_lhs (stmt);
1222 if (t && !disqualify_ops_if_throwing_stmt (stmt, t, NULL))
1223 ret |= build_access_from_expr (t, stmt, true);
1227 walk_stmt_load_store_addr_ops (stmt, NULL, NULL, NULL,
1230 bitmap_set_bit (final_bbs, bb->index);
1232 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
1234 t = TREE_VALUE (gimple_asm_input_op (stmt, i));
1235 ret |= build_access_from_expr (t, stmt, false);
1237 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
1239 t = TREE_VALUE (gimple_asm_output_op (stmt, i));
1240 ret |= build_access_from_expr (t, stmt, true);
1253 /* Helper of QSORT function. There are pointers to accesses in the array. An
1254 access is considered smaller than another if it has smaller offset or if the
1255 offsets are the same but is size is bigger. */
1258 compare_access_positions (const void *a, const void *b)
1260 const access_p *fp1 = (const access_p *) a;
1261 const access_p *fp2 = (const access_p *) b;
1262 const access_p f1 = *fp1;
1263 const access_p f2 = *fp2;
1265 if (f1->offset != f2->offset)
1266 return f1->offset < f2->offset ? -1 : 1;
1268 if (f1->size == f2->size)
1270 if (f1->type == f2->type)
1272 /* Put any non-aggregate type before any aggregate type. */
1273 else if (!is_gimple_reg_type (f1->type)
1274 && is_gimple_reg_type (f2->type))
1276 else if (is_gimple_reg_type (f1->type)
1277 && !is_gimple_reg_type (f2->type))
1279 /* Put any complex or vector type before any other scalar type. */
1280 else if (TREE_CODE (f1->type) != COMPLEX_TYPE
1281 && TREE_CODE (f1->type) != VECTOR_TYPE
1282 && (TREE_CODE (f2->type) == COMPLEX_TYPE
1283 || TREE_CODE (f2->type) == VECTOR_TYPE))
1285 else if ((TREE_CODE (f1->type) == COMPLEX_TYPE
1286 || TREE_CODE (f1->type) == VECTOR_TYPE)
1287 && TREE_CODE (f2->type) != COMPLEX_TYPE
1288 && TREE_CODE (f2->type) != VECTOR_TYPE)
1290 /* Put the integral type with the bigger precision first. */
1291 else if (INTEGRAL_TYPE_P (f1->type)
1292 && INTEGRAL_TYPE_P (f2->type))
1293 return TYPE_PRECISION (f2->type) - TYPE_PRECISION (f1->type);
1294 /* Put any integral type with non-full precision last. */
1295 else if (INTEGRAL_TYPE_P (f1->type)
1296 && (TREE_INT_CST_LOW (TYPE_SIZE (f1->type))
1297 != TYPE_PRECISION (f1->type)))
1299 else if (INTEGRAL_TYPE_P (f2->type)
1300 && (TREE_INT_CST_LOW (TYPE_SIZE (f2->type))
1301 != TYPE_PRECISION (f2->type)))
1303 /* Stabilize the sort. */
1304 return TYPE_UID (f1->type) - TYPE_UID (f2->type);
1307 /* We want the bigger accesses first, thus the opposite operator in the next
1309 return f1->size > f2->size ? -1 : 1;
1313 /* Append a name of the declaration to the name obstack. A helper function for
1317 make_fancy_decl_name (tree decl)
1321 tree name = DECL_NAME (decl);
1323 obstack_grow (&name_obstack, IDENTIFIER_POINTER (name),
1324 IDENTIFIER_LENGTH (name));
1327 sprintf (buffer, "D%u", DECL_UID (decl));
1328 obstack_grow (&name_obstack, buffer, strlen (buffer));
1332 /* Helper for make_fancy_name. */
1335 make_fancy_name_1 (tree expr)
1342 make_fancy_decl_name (expr);
1346 switch (TREE_CODE (expr))
1349 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1350 obstack_1grow (&name_obstack, '$');
1351 make_fancy_decl_name (TREE_OPERAND (expr, 1));
1355 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1356 obstack_1grow (&name_obstack, '$');
1357 /* Arrays with only one element may not have a constant as their
1359 index = TREE_OPERAND (expr, 1);
1360 if (TREE_CODE (index) != INTEGER_CST)
1362 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC, TREE_INT_CST_LOW (index));
1363 obstack_grow (&name_obstack, buffer, strlen (buffer));
1367 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1371 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1372 if (!integer_zerop (TREE_OPERAND (expr, 1)))
1374 obstack_1grow (&name_obstack, '$');
1375 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC,
1376 TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)));
1377 obstack_grow (&name_obstack, buffer, strlen (buffer));
1384 gcc_unreachable (); /* we treat these as scalars. */
1391 /* Create a human readable name for replacement variable of ACCESS. */
1394 make_fancy_name (tree expr)
1396 make_fancy_name_1 (expr);
1397 obstack_1grow (&name_obstack, '\0');
1398 return XOBFINISH (&name_obstack, char *);
1401 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1402 EXP_TYPE at the given OFFSET. If BASE is something for which
1403 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1404 to insert new statements either before or below the current one as specified
1405 by INSERT_AFTER. This function is not capable of handling bitfields. */
1408 build_ref_for_offset (location_t loc, tree base, HOST_WIDE_INT offset,
1409 tree exp_type, gimple_stmt_iterator *gsi,
1412 tree prev_base = base;
1414 HOST_WIDE_INT base_offset;
1416 gcc_checking_assert (offset % BITS_PER_UNIT == 0);
1418 base = get_addr_base_and_unit_offset (base, &base_offset);
1420 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1421 offset such as array[var_index]. */
1427 gcc_checking_assert (gsi);
1428 tmp = create_tmp_reg (build_pointer_type (TREE_TYPE (prev_base)), NULL);
1429 add_referenced_var (tmp);
1430 tmp = make_ssa_name (tmp, NULL);
1431 addr = build_fold_addr_expr (unshare_expr (prev_base));
1432 stmt = gimple_build_assign (tmp, addr);
1433 gimple_set_location (stmt, loc);
1434 SSA_NAME_DEF_STMT (tmp) = stmt;
1436 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
1438 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1441 off = build_int_cst (reference_alias_ptr_type (prev_base),
1442 offset / BITS_PER_UNIT);
1445 else if (TREE_CODE (base) == MEM_REF)
1447 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1448 base_offset + offset / BITS_PER_UNIT);
1449 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off, 0);
1450 base = unshare_expr (TREE_OPERAND (base, 0));
1454 off = build_int_cst (reference_alias_ptr_type (base),
1455 base_offset + offset / BITS_PER_UNIT);
1456 base = build_fold_addr_expr (unshare_expr (base));
1459 return fold_build2_loc (loc, MEM_REF, exp_type, base, off);
1462 DEF_VEC_ALLOC_P_STACK (tree);
1463 #define VEC_tree_stack_alloc(alloc) VEC_stack_alloc (tree, alloc)
1465 /* Construct a memory reference to a part of an aggregate BASE at the given
1466 OFFSET and of the type of MODEL. In case this is a chain of references
1467 to component, the function will replicate the chain of COMPONENT_REFs of
1468 the expression of MODEL to access it. GSI and INSERT_AFTER have the same
1469 meaning as in build_ref_for_offset. */
1472 build_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1473 struct access *model, gimple_stmt_iterator *gsi,
1476 tree type = model->type, t;
1477 VEC(tree,stack) *cr_stack = NULL;
1479 if (TREE_CODE (model->expr) == COMPONENT_REF)
1481 tree expr = model->expr;
1483 /* Create a stack of the COMPONENT_REFs so later we can walk them in
1484 order from inner to outer. */
1485 cr_stack = VEC_alloc (tree, stack, 6);
1488 tree field = TREE_OPERAND (expr, 1);
1489 HOST_WIDE_INT bit_pos = int_bit_position (field);
1491 /* We can be called with a model different from the one associated
1492 with BASE so we need to avoid going up the chain too far. */
1493 if (offset - bit_pos < 0)
1497 VEC_safe_push (tree, stack, cr_stack, expr);
1499 expr = TREE_OPERAND (expr, 0);
1500 type = TREE_TYPE (expr);
1501 } while (TREE_CODE (expr) == COMPONENT_REF);
1504 t = build_ref_for_offset (loc, base, offset, type, gsi, insert_after);
1506 if (TREE_CODE (model->expr) == COMPONENT_REF)
1511 /* Now replicate the chain of COMPONENT_REFs from inner to outer. */
1512 FOR_EACH_VEC_ELT_REVERSE (tree, cr_stack, i, expr)
1514 tree field = TREE_OPERAND (expr, 1);
1515 t = fold_build3_loc (loc, COMPONENT_REF, TREE_TYPE (field), t, field,
1519 VEC_free (tree, stack, cr_stack);
1525 /* Construct a memory reference consisting of component_refs and array_refs to
1526 a part of an aggregate *RES (which is of type TYPE). The requested part
1527 should have type EXP_TYPE at be the given OFFSET. This function might not
1528 succeed, it returns true when it does and only then *RES points to something
1529 meaningful. This function should be used only to build expressions that we
1530 might need to present to user (e.g. in warnings). In all other situations,
1531 build_ref_for_model or build_ref_for_offset should be used instead. */
1534 build_user_friendly_ref_for_offset (tree *res, tree type, HOST_WIDE_INT offset,
1540 tree tr_size, index, minidx;
1541 HOST_WIDE_INT el_size;
1543 if (offset == 0 && exp_type
1544 && types_compatible_p (exp_type, type))
1547 switch (TREE_CODE (type))
1550 case QUAL_UNION_TYPE:
1552 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
1554 HOST_WIDE_INT pos, size;
1555 tree expr, *expr_ptr;
1557 if (TREE_CODE (fld) != FIELD_DECL)
1560 pos = int_bit_position (fld);
1561 gcc_assert (TREE_CODE (type) == RECORD_TYPE || pos == 0);
1562 tr_size = DECL_SIZE (fld);
1563 if (!tr_size || !host_integerp (tr_size, 1))
1565 size = tree_low_cst (tr_size, 1);
1571 else if (pos > offset || (pos + size) <= offset)
1574 expr = build3 (COMPONENT_REF, TREE_TYPE (fld), *res, fld,
1577 if (build_user_friendly_ref_for_offset (expr_ptr, TREE_TYPE (fld),
1578 offset - pos, exp_type))
1587 tr_size = TYPE_SIZE (TREE_TYPE (type));
1588 if (!tr_size || !host_integerp (tr_size, 1))
1590 el_size = tree_low_cst (tr_size, 1);
1592 minidx = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
1593 if (TREE_CODE (minidx) != INTEGER_CST || el_size == 0)
1595 index = build_int_cst (TYPE_DOMAIN (type), offset / el_size);
1596 if (!integer_zerop (minidx))
1597 index = int_const_binop (PLUS_EXPR, index, minidx, 0);
1598 *res = build4 (ARRAY_REF, TREE_TYPE (type), *res, index,
1599 NULL_TREE, NULL_TREE);
1600 offset = offset % el_size;
1601 type = TREE_TYPE (type);
1616 /* Return true iff TYPE is stdarg va_list type. */
1619 is_va_list_type (tree type)
1621 return TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (va_list_type_node);
1624 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1625 those with type which is suitable for scalarization. */
1628 find_var_candidates (void)
1631 referenced_var_iterator rvi;
1634 FOR_EACH_REFERENCED_VAR (cfun, var, rvi)
1636 if (TREE_CODE (var) != VAR_DECL && TREE_CODE (var) != PARM_DECL)
1638 type = TREE_TYPE (var);
1640 if (!AGGREGATE_TYPE_P (type)
1641 || needs_to_live_in_memory (var)
1642 || TREE_THIS_VOLATILE (var)
1643 || !COMPLETE_TYPE_P (type)
1644 || !host_integerp (TYPE_SIZE (type), 1)
1645 || tree_low_cst (TYPE_SIZE (type), 1) == 0
1646 || type_internals_preclude_sra_p (type)
1647 /* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1648 we also want to schedule it rather late. Thus we ignore it in
1650 || (sra_mode == SRA_MODE_EARLY_INTRA
1651 && is_va_list_type (type)))
1654 bitmap_set_bit (candidate_bitmap, DECL_UID (var));
1656 if (dump_file && (dump_flags & TDF_DETAILS))
1658 fprintf (dump_file, "Candidate (%d): ", DECL_UID (var));
1659 print_generic_expr (dump_file, var, 0);
1660 fprintf (dump_file, "\n");
1668 /* Sort all accesses for the given variable, check for partial overlaps and
1669 return NULL if there are any. If there are none, pick a representative for
1670 each combination of offset and size and create a linked list out of them.
1671 Return the pointer to the first representative and make sure it is the first
1672 one in the vector of accesses. */
1674 static struct access *
1675 sort_and_splice_var_accesses (tree var)
1677 int i, j, access_count;
1678 struct access *res, **prev_acc_ptr = &res;
1679 VEC (access_p, heap) *access_vec;
1681 HOST_WIDE_INT low = -1, high = 0;
1683 access_vec = get_base_access_vector (var);
1686 access_count = VEC_length (access_p, access_vec);
1688 /* Sort by <OFFSET, SIZE>. */
1689 VEC_qsort (access_p, access_vec, compare_access_positions);
1692 while (i < access_count)
1694 struct access *access = VEC_index (access_p, access_vec, i);
1695 bool grp_write = access->write;
1696 bool grp_read = !access->write;
1697 bool grp_scalar_write = access->write
1698 && is_gimple_reg_type (access->type);
1699 bool grp_scalar_read = !access->write
1700 && is_gimple_reg_type (access->type);
1701 bool grp_assignment_read = access->grp_assignment_read;
1702 bool grp_assignment_write = access->grp_assignment_write;
1703 bool multiple_scalar_reads = false;
1704 bool total_scalarization = access->total_scalarization;
1705 bool grp_partial_lhs = access->grp_partial_lhs;
1706 bool first_scalar = is_gimple_reg_type (access->type);
1707 bool unscalarizable_region = access->grp_unscalarizable_region;
1709 if (first || access->offset >= high)
1712 low = access->offset;
1713 high = access->offset + access->size;
1715 else if (access->offset > low && access->offset + access->size > high)
1718 gcc_assert (access->offset >= low
1719 && access->offset + access->size <= high);
1722 while (j < access_count)
1724 struct access *ac2 = VEC_index (access_p, access_vec, j);
1725 if (ac2->offset != access->offset || ac2->size != access->size)
1730 grp_scalar_write = (grp_scalar_write
1731 || is_gimple_reg_type (ac2->type));
1736 if (is_gimple_reg_type (ac2->type))
1738 if (grp_scalar_read)
1739 multiple_scalar_reads = true;
1741 grp_scalar_read = true;
1744 grp_assignment_read |= ac2->grp_assignment_read;
1745 grp_assignment_write |= ac2->grp_assignment_write;
1746 grp_partial_lhs |= ac2->grp_partial_lhs;
1747 unscalarizable_region |= ac2->grp_unscalarizable_region;
1748 total_scalarization |= ac2->total_scalarization;
1749 relink_to_new_repr (access, ac2);
1751 /* If there are both aggregate-type and scalar-type accesses with
1752 this combination of size and offset, the comparison function
1753 should have put the scalars first. */
1754 gcc_assert (first_scalar || !is_gimple_reg_type (ac2->type));
1755 ac2->group_representative = access;
1761 access->group_representative = access;
1762 access->grp_write = grp_write;
1763 access->grp_read = grp_read;
1764 access->grp_scalar_read = grp_scalar_read;
1765 access->grp_scalar_write = grp_scalar_write;
1766 access->grp_assignment_read = grp_assignment_read;
1767 access->grp_assignment_write = grp_assignment_write;
1768 access->grp_hint = multiple_scalar_reads || total_scalarization;
1769 access->grp_partial_lhs = grp_partial_lhs;
1770 access->grp_unscalarizable_region = unscalarizable_region;
1771 if (access->first_link)
1772 add_access_to_work_queue (access);
1774 *prev_acc_ptr = access;
1775 prev_acc_ptr = &access->next_grp;
1778 gcc_assert (res == VEC_index (access_p, access_vec, 0));
1782 /* Create a variable for the given ACCESS which determines the type, name and a
1783 few other properties. Return the variable declaration and store it also to
1784 ACCESS->replacement. */
1787 create_access_replacement (struct access *access, bool rename)
1791 repl = create_tmp_var (access->type, "SR");
1793 add_referenced_var (repl);
1795 mark_sym_for_renaming (repl);
1797 if (!access->grp_partial_lhs
1798 && (TREE_CODE (access->type) == COMPLEX_TYPE
1799 || TREE_CODE (access->type) == VECTOR_TYPE))
1800 DECL_GIMPLE_REG_P (repl) = 1;
1802 DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
1803 DECL_ARTIFICIAL (repl) = 1;
1804 DECL_IGNORED_P (repl) = DECL_IGNORED_P (access->base);
1806 if (DECL_NAME (access->base)
1807 && !DECL_IGNORED_P (access->base)
1808 && !DECL_ARTIFICIAL (access->base))
1810 char *pretty_name = make_fancy_name (access->expr);
1811 tree debug_expr = unshare_expr (access->expr), d;
1813 DECL_NAME (repl) = get_identifier (pretty_name);
1814 obstack_free (&name_obstack, pretty_name);
1816 /* Get rid of any SSA_NAMEs embedded in debug_expr,
1817 as DECL_DEBUG_EXPR isn't considered when looking for still
1818 used SSA_NAMEs and thus they could be freed. All debug info
1819 generation cares is whether something is constant or variable
1820 and that get_ref_base_and_extent works properly on the
1822 for (d = debug_expr; handled_component_p (d); d = TREE_OPERAND (d, 0))
1823 switch (TREE_CODE (d))
1826 case ARRAY_RANGE_REF:
1827 if (TREE_OPERAND (d, 1)
1828 && TREE_CODE (TREE_OPERAND (d, 1)) == SSA_NAME)
1829 TREE_OPERAND (d, 1) = SSA_NAME_VAR (TREE_OPERAND (d, 1));
1830 if (TREE_OPERAND (d, 3)
1831 && TREE_CODE (TREE_OPERAND (d, 3)) == SSA_NAME)
1832 TREE_OPERAND (d, 3) = SSA_NAME_VAR (TREE_OPERAND (d, 3));
1835 if (TREE_OPERAND (d, 2)
1836 && TREE_CODE (TREE_OPERAND (d, 2)) == SSA_NAME)
1837 TREE_OPERAND (d, 2) = SSA_NAME_VAR (TREE_OPERAND (d, 2));
1842 SET_DECL_DEBUG_EXPR (repl, debug_expr);
1843 DECL_DEBUG_EXPR_IS_FROM (repl) = 1;
1844 if (access->grp_no_warning)
1845 TREE_NO_WARNING (repl) = 1;
1847 TREE_NO_WARNING (repl) = TREE_NO_WARNING (access->base);
1850 TREE_NO_WARNING (repl) = 1;
1854 fprintf (dump_file, "Created a replacement for ");
1855 print_generic_expr (dump_file, access->base, 0);
1856 fprintf (dump_file, " offset: %u, size: %u: ",
1857 (unsigned) access->offset, (unsigned) access->size);
1858 print_generic_expr (dump_file, repl, 0);
1859 fprintf (dump_file, "\n");
1861 sra_stats.replacements++;
1866 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
1869 get_access_replacement (struct access *access)
1871 gcc_assert (access->grp_to_be_replaced);
1873 if (!access->replacement_decl)
1874 access->replacement_decl = create_access_replacement (access, true);
1875 return access->replacement_decl;
1878 /* Return ACCESS scalar replacement, create it if it does not exist yet but do
1879 not mark it for renaming. */
1882 get_unrenamed_access_replacement (struct access *access)
1884 gcc_assert (!access->grp_to_be_replaced);
1886 if (!access->replacement_decl)
1887 access->replacement_decl = create_access_replacement (access, false);
1888 return access->replacement_decl;
1892 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
1893 linked list along the way. Stop when *ACCESS is NULL or the access pointed
1894 to it is not "within" the root. Return false iff some accesses partially
1898 build_access_subtree (struct access **access)
1900 struct access *root = *access, *last_child = NULL;
1901 HOST_WIDE_INT limit = root->offset + root->size;
1903 *access = (*access)->next_grp;
1904 while (*access && (*access)->offset + (*access)->size <= limit)
1907 root->first_child = *access;
1909 last_child->next_sibling = *access;
1910 last_child = *access;
1912 if (!build_access_subtree (access))
1916 if (*access && (*access)->offset < limit)
1922 /* Build a tree of access representatives, ACCESS is the pointer to the first
1923 one, others are linked in a list by the next_grp field. Return false iff
1924 some accesses partially overlap. */
1927 build_access_trees (struct access *access)
1931 struct access *root = access;
1933 if (!build_access_subtree (&access))
1935 root->next_grp = access;
1940 /* Return true if expr contains some ARRAY_REFs into a variable bounded
1944 expr_with_var_bounded_array_refs_p (tree expr)
1946 while (handled_component_p (expr))
1948 if (TREE_CODE (expr) == ARRAY_REF
1949 && !host_integerp (array_ref_low_bound (expr), 0))
1951 expr = TREE_OPERAND (expr, 0);
1956 enum mark_rw_status { SRA_MRRW_NOTHING, SRA_MRRW_DIRECT, SRA_MRRW_ASSIGN};
1958 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
1959 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
1960 sorts of access flags appropriately along the way, notably always set
1961 grp_read and grp_assign_read according to MARK_READ and grp_write when
1964 Creating a replacement for a scalar access is considered beneficial if its
1965 grp_hint is set (this means we are either attempting total scalarization or
1966 there is more than one direct read access) or according to the following
1969 Access written to through a scalar type (once or more times)
1971 | Written to in an assignment statement
1973 | | Access read as scalar _once_
1975 | | | Read in an assignment statement
1977 | | | | Scalarize Comment
1978 -----------------------------------------------------------------------------
1979 0 0 0 0 No access for the scalar
1980 0 0 0 1 No access for the scalar
1981 0 0 1 0 No Single read - won't help
1982 0 0 1 1 No The same case
1983 0 1 0 0 No access for the scalar
1984 0 1 0 1 No access for the scalar
1985 0 1 1 0 Yes s = *g; return s.i;
1986 0 1 1 1 Yes The same case as above
1987 1 0 0 0 No Won't help
1988 1 0 0 1 Yes s.i = 1; *g = s;
1989 1 0 1 0 Yes s.i = 5; g = s.i;
1990 1 0 1 1 Yes The same case as above
1991 1 1 0 0 No Won't help.
1992 1 1 0 1 Yes s.i = 1; *g = s;
1993 1 1 1 0 Yes s = *g; return s.i;
1994 1 1 1 1 Yes Any of the above yeses */
1997 analyze_access_subtree (struct access *root, bool allow_replacements,
1998 enum mark_rw_status mark_read,
1999 enum mark_rw_status mark_write)
2001 struct access *child;
2002 HOST_WIDE_INT limit = root->offset + root->size;
2003 HOST_WIDE_INT covered_to = root->offset;
2004 bool scalar = is_gimple_reg_type (root->type);
2005 bool hole = false, sth_created = false;
2007 if (root->grp_assignment_read)
2008 mark_read = SRA_MRRW_ASSIGN;
2009 else if (mark_read == SRA_MRRW_ASSIGN)
2012 root->grp_assignment_read = 1;
2014 else if (mark_read == SRA_MRRW_DIRECT)
2016 else if (root->grp_read)
2017 mark_read = SRA_MRRW_DIRECT;
2019 if (root->grp_assignment_write)
2020 mark_write = SRA_MRRW_ASSIGN;
2021 else if (mark_write == SRA_MRRW_ASSIGN)
2023 root->grp_write = 1;
2024 root->grp_assignment_write = 1;
2026 else if (mark_write == SRA_MRRW_DIRECT)
2027 root->grp_write = 1;
2028 else if (root->grp_write)
2029 mark_write = SRA_MRRW_DIRECT;
2031 if (root->grp_unscalarizable_region)
2032 allow_replacements = false;
2034 if (allow_replacements && expr_with_var_bounded_array_refs_p (root->expr))
2035 allow_replacements = false;
2037 for (child = root->first_child; child; child = child->next_sibling)
2039 if (!hole && child->offset < covered_to)
2042 covered_to += child->size;
2044 sth_created |= analyze_access_subtree (child,
2045 allow_replacements && !scalar,
2046 mark_read, mark_write);
2048 root->grp_unscalarized_data |= child->grp_unscalarized_data;
2049 hole |= !child->grp_covered;
2052 if (allow_replacements && scalar && !root->first_child
2054 || ((root->grp_scalar_read || root->grp_assignment_read)
2055 && (root->grp_scalar_write || root->grp_assignment_write))))
2057 bool new_integer_type;
2058 if (TREE_CODE (root->type) == ENUMERAL_TYPE)
2060 tree rt = root->type;
2061 root->type = build_nonstandard_integer_type (TYPE_PRECISION (rt),
2062 TYPE_UNSIGNED (rt));
2063 new_integer_type = true;
2066 new_integer_type = false;
2068 if (dump_file && (dump_flags & TDF_DETAILS))
2070 fprintf (dump_file, "Marking ");
2071 print_generic_expr (dump_file, root->base, 0);
2072 fprintf (dump_file, " offset: %u, size: %u ",
2073 (unsigned) root->offset, (unsigned) root->size);
2074 fprintf (dump_file, " to be replaced%s.\n",
2075 new_integer_type ? " with an integer": "");
2078 root->grp_to_be_replaced = 1;
2082 else if (covered_to < limit)
2085 if (sth_created && !hole)
2087 root->grp_covered = 1;
2090 if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
2091 root->grp_unscalarized_data = 1; /* not covered and written to */
2097 /* Analyze all access trees linked by next_grp by the means of
2098 analyze_access_subtree. */
2100 analyze_access_trees (struct access *access)
2106 if (analyze_access_subtree (access, true,
2107 SRA_MRRW_NOTHING, SRA_MRRW_NOTHING))
2109 access = access->next_grp;
2115 /* Return true iff a potential new child of LACC at offset OFFSET and with size
2116 SIZE would conflict with an already existing one. If exactly such a child
2117 already exists in LACC, store a pointer to it in EXACT_MATCH. */
2120 child_would_conflict_in_lacc (struct access *lacc, HOST_WIDE_INT norm_offset,
2121 HOST_WIDE_INT size, struct access **exact_match)
2123 struct access *child;
2125 for (child = lacc->first_child; child; child = child->next_sibling)
2127 if (child->offset == norm_offset && child->size == size)
2129 *exact_match = child;
2133 if (child->offset < norm_offset + size
2134 && child->offset + child->size > norm_offset)
2141 /* Create a new child access of PARENT, with all properties just like MODEL
2142 except for its offset and with its grp_write false and grp_read true.
2143 Return the new access or NULL if it cannot be created. Note that this access
2144 is created long after all splicing and sorting, it's not located in any
2145 access vector and is automatically a representative of its group. */
2147 static struct access *
2148 create_artificial_child_access (struct access *parent, struct access *model,
2149 HOST_WIDE_INT new_offset)
2151 struct access *access;
2152 struct access **child;
2153 tree expr = parent->base;
2155 gcc_assert (!model->grp_unscalarizable_region);
2157 access = (struct access *) pool_alloc (access_pool);
2158 memset (access, 0, sizeof (struct access));
2159 if (!build_user_friendly_ref_for_offset (&expr, TREE_TYPE (expr), new_offset,
2162 access->grp_no_warning = true;
2163 expr = build_ref_for_model (EXPR_LOCATION (parent->base), parent->base,
2164 new_offset, model, NULL, false);
2167 access->base = parent->base;
2168 access->expr = expr;
2169 access->offset = new_offset;
2170 access->size = model->size;
2171 access->type = model->type;
2172 access->grp_write = true;
2173 access->grp_read = false;
2175 child = &parent->first_child;
2176 while (*child && (*child)->offset < new_offset)
2177 child = &(*child)->next_sibling;
2179 access->next_sibling = *child;
2186 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2187 true if any new subaccess was created. Additionally, if RACC is a scalar
2188 access but LACC is not, change the type of the latter, if possible. */
2191 propagate_subaccesses_across_link (struct access *lacc, struct access *racc)
2193 struct access *rchild;
2194 HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
2197 if (is_gimple_reg_type (lacc->type)
2198 || lacc->grp_unscalarizable_region
2199 || racc->grp_unscalarizable_region)
2202 if (!lacc->first_child && !racc->first_child
2203 && is_gimple_reg_type (racc->type))
2205 tree t = lacc->base;
2207 lacc->type = racc->type;
2208 if (build_user_friendly_ref_for_offset (&t, TREE_TYPE (t), lacc->offset,
2213 lacc->expr = build_ref_for_model (EXPR_LOCATION (lacc->base),
2214 lacc->base, lacc->offset,
2216 lacc->grp_no_warning = true;
2221 for (rchild = racc->first_child; rchild; rchild = rchild->next_sibling)
2223 struct access *new_acc = NULL;
2224 HOST_WIDE_INT norm_offset = rchild->offset + norm_delta;
2226 if (rchild->grp_unscalarizable_region)
2229 if (child_would_conflict_in_lacc (lacc, norm_offset, rchild->size,
2234 rchild->grp_hint = 1;
2235 new_acc->grp_hint |= new_acc->grp_read;
2236 if (rchild->first_child)
2237 ret |= propagate_subaccesses_across_link (new_acc, rchild);
2242 rchild->grp_hint = 1;
2243 new_acc = create_artificial_child_access (lacc, rchild, norm_offset);
2247 if (racc->first_child)
2248 propagate_subaccesses_across_link (new_acc, rchild);
2255 /* Propagate all subaccesses across assignment links. */
2258 propagate_all_subaccesses (void)
2260 while (work_queue_head)
2262 struct access *racc = pop_access_from_work_queue ();
2263 struct assign_link *link;
2265 gcc_assert (racc->first_link);
2267 for (link = racc->first_link; link; link = link->next)
2269 struct access *lacc = link->lacc;
2271 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (lacc->base)))
2273 lacc = lacc->group_representative;
2274 if (propagate_subaccesses_across_link (lacc, racc)
2275 && lacc->first_link)
2276 add_access_to_work_queue (lacc);
2281 /* Go through all accesses collected throughout the (intraprocedural) analysis
2282 stage, exclude overlapping ones, identify representatives and build trees
2283 out of them, making decisions about scalarization on the way. Return true
2284 iff there are any to-be-scalarized variables after this stage. */
2287 analyze_all_variable_accesses (void)
2290 bitmap tmp = BITMAP_ALLOC (NULL);
2292 unsigned i, max_total_scalarization_size;
2294 max_total_scalarization_size = UNITS_PER_WORD * BITS_PER_UNIT
2295 * MOVE_RATIO (optimize_function_for_speed_p (cfun));
2297 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
2298 if (bitmap_bit_p (should_scalarize_away_bitmap, i)
2299 && !bitmap_bit_p (cannot_scalarize_away_bitmap, i))
2301 tree var = referenced_var (i);
2303 if (TREE_CODE (var) == VAR_DECL
2304 && ((unsigned) tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1)
2305 <= max_total_scalarization_size)
2306 && type_consists_of_records_p (TREE_TYPE (var)))
2308 completely_scalarize_record (var, var, 0, var);
2309 if (dump_file && (dump_flags & TDF_DETAILS))
2311 fprintf (dump_file, "Will attempt to totally scalarize ");
2312 print_generic_expr (dump_file, var, 0);
2313 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2318 bitmap_copy (tmp, candidate_bitmap);
2319 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2321 tree var = referenced_var (i);
2322 struct access *access;
2324 access = sort_and_splice_var_accesses (var);
2325 if (!access || !build_access_trees (access))
2326 disqualify_candidate (var,
2327 "No or inhibitingly overlapping accesses.");
2330 propagate_all_subaccesses ();
2332 bitmap_copy (tmp, candidate_bitmap);
2333 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2335 tree var = referenced_var (i);
2336 struct access *access = get_first_repr_for_decl (var);
2338 if (analyze_access_trees (access))
2341 if (dump_file && (dump_flags & TDF_DETAILS))
2343 fprintf (dump_file, "\nAccess trees for ");
2344 print_generic_expr (dump_file, var, 0);
2345 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2346 dump_access_tree (dump_file, access);
2347 fprintf (dump_file, "\n");
2351 disqualify_candidate (var, "No scalar replacements to be created.");
2358 statistics_counter_event (cfun, "Scalarized aggregates", res);
2365 /* Generate statements copying scalar replacements of accesses within a subtree
2366 into or out of AGG. ACCESS, all its children, siblings and their children
2367 are to be processed. AGG is an aggregate type expression (can be a
2368 declaration but does not have to be, it can for example also be a mem_ref or
2369 a series of handled components). TOP_OFFSET is the offset of the processed
2370 subtree which has to be subtracted from offsets of individual accesses to
2371 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2372 replacements in the interval <start_offset, start_offset + chunk_size>,
2373 otherwise copy all. GSI is a statement iterator used to place the new
2374 statements. WRITE should be true when the statements should write from AGG
2375 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2376 statements will be added after the current statement in GSI, they will be
2377 added before the statement otherwise. */
2380 generate_subtree_copies (struct access *access, tree agg,
2381 HOST_WIDE_INT top_offset,
2382 HOST_WIDE_INT start_offset, HOST_WIDE_INT chunk_size,
2383 gimple_stmt_iterator *gsi, bool write,
2384 bool insert_after, location_t loc)
2388 if (chunk_size && access->offset >= start_offset + chunk_size)
2391 if (access->grp_to_be_replaced
2393 || access->offset + access->size > start_offset))
2395 tree expr, repl = get_access_replacement (access);
2398 expr = build_ref_for_model (loc, agg, access->offset - top_offset,
2399 access, gsi, insert_after);
2403 if (access->grp_partial_lhs)
2404 expr = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE,
2406 insert_after ? GSI_NEW_STMT
2408 stmt = gimple_build_assign (repl, expr);
2412 TREE_NO_WARNING (repl) = 1;
2413 if (access->grp_partial_lhs)
2414 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2416 insert_after ? GSI_NEW_STMT
2418 stmt = gimple_build_assign (expr, repl);
2420 gimple_set_location (stmt, loc);
2423 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2425 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2427 sra_stats.subtree_copies++;
2430 if (access->first_child)
2431 generate_subtree_copies (access->first_child, agg, top_offset,
2432 start_offset, chunk_size, gsi,
2433 write, insert_after, loc);
2435 access = access->next_sibling;
2440 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2441 the root of the subtree to be processed. GSI is the statement iterator used
2442 for inserting statements which are added after the current statement if
2443 INSERT_AFTER is true or before it otherwise. */
2446 init_subtree_with_zero (struct access *access, gimple_stmt_iterator *gsi,
2447 bool insert_after, location_t loc)
2450 struct access *child;
2452 if (access->grp_to_be_replaced)
2456 stmt = gimple_build_assign (get_access_replacement (access),
2457 build_zero_cst (access->type));
2459 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2461 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2463 gimple_set_location (stmt, loc);
2466 for (child = access->first_child; child; child = child->next_sibling)
2467 init_subtree_with_zero (child, gsi, insert_after, loc);
2470 /* Search for an access representative for the given expression EXPR and
2471 return it or NULL if it cannot be found. */
2473 static struct access *
2474 get_access_for_expr (tree expr)
2476 HOST_WIDE_INT offset, size, max_size;
2479 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2480 a different size than the size of its argument and we need the latter
2482 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
2483 expr = TREE_OPERAND (expr, 0);
2485 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
2486 if (max_size == -1 || !DECL_P (base))
2489 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
2492 return get_var_base_offset_size_access (base, offset, max_size);
2495 /* Replace the expression EXPR with a scalar replacement if there is one and
2496 generate other statements to do type conversion or subtree copying if
2497 necessary. GSI is used to place newly created statements, WRITE is true if
2498 the expression is being written to (it is on a LHS of a statement or output
2499 in an assembly statement). */
2502 sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write)
2505 struct access *access;
2508 if (TREE_CODE (*expr) == BIT_FIELD_REF)
2511 expr = &TREE_OPERAND (*expr, 0);
2516 if (TREE_CODE (*expr) == REALPART_EXPR || TREE_CODE (*expr) == IMAGPART_EXPR)
2517 expr = &TREE_OPERAND (*expr, 0);
2518 access = get_access_for_expr (*expr);
2521 type = TREE_TYPE (*expr);
2523 loc = gimple_location (gsi_stmt (*gsi));
2524 if (access->grp_to_be_replaced)
2526 tree repl = get_access_replacement (access);
2527 /* If we replace a non-register typed access simply use the original
2528 access expression to extract the scalar component afterwards.
2529 This happens if scalarizing a function return value or parameter
2530 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2531 gcc.c-torture/compile/20011217-1.c.
2533 We also want to use this when accessing a complex or vector which can
2534 be accessed as a different type too, potentially creating a need for
2535 type conversion (see PR42196) and when scalarized unions are involved
2536 in assembler statements (see PR42398). */
2537 if (!useless_type_conversion_p (type, access->type))
2541 ref = build_ref_for_model (loc, access->base, access->offset, access,
2548 if (access->grp_partial_lhs)
2549 ref = force_gimple_operand_gsi (gsi, ref, true, NULL_TREE,
2550 false, GSI_NEW_STMT);
2551 stmt = gimple_build_assign (repl, ref);
2552 gimple_set_location (stmt, loc);
2553 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2559 if (access->grp_partial_lhs)
2560 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2561 true, GSI_SAME_STMT);
2562 stmt = gimple_build_assign (ref, repl);
2563 gimple_set_location (stmt, loc);
2564 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2572 if (access->first_child)
2574 HOST_WIDE_INT start_offset, chunk_size;
2576 && host_integerp (TREE_OPERAND (bfr, 1), 1)
2577 && host_integerp (TREE_OPERAND (bfr, 2), 1))
2579 chunk_size = tree_low_cst (TREE_OPERAND (bfr, 1), 1);
2580 start_offset = access->offset
2581 + tree_low_cst (TREE_OPERAND (bfr, 2), 1);
2584 start_offset = chunk_size = 0;
2586 generate_subtree_copies (access->first_child, access->base, 0,
2587 start_offset, chunk_size, gsi, write, write,
2593 /* Where scalar replacements of the RHS have been written to when a replacement
2594 of a LHS of an assigments cannot be direclty loaded from a replacement of
2596 enum unscalarized_data_handling { SRA_UDH_NONE, /* Nothing done so far. */
2597 SRA_UDH_RIGHT, /* Data flushed to the RHS. */
2598 SRA_UDH_LEFT }; /* Data flushed to the LHS. */
2600 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2601 base aggregate if there are unscalarized data or directly to LHS of the
2602 statement that is pointed to by GSI otherwise. */
2604 static enum unscalarized_data_handling
2605 handle_unscalarized_data_in_subtree (struct access *top_racc,
2606 gimple_stmt_iterator *gsi)
2608 if (top_racc->grp_unscalarized_data)
2610 generate_subtree_copies (top_racc->first_child, top_racc->base, 0, 0, 0,
2612 gimple_location (gsi_stmt (*gsi)));
2613 return SRA_UDH_RIGHT;
2617 tree lhs = gimple_assign_lhs (gsi_stmt (*gsi));
2618 generate_subtree_copies (top_racc->first_child, lhs, top_racc->offset,
2619 0, 0, gsi, false, false,
2620 gimple_location (gsi_stmt (*gsi)));
2621 return SRA_UDH_LEFT;
2626 /* Try to generate statements to load all sub-replacements in an access subtree
2627 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2628 If that is not possible, refresh the TOP_RACC base aggregate and load the
2629 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2630 copied. NEW_GSI is stmt iterator used for statement insertions after the
2631 original assignment, OLD_GSI is used to insert statements before the
2632 assignment. *REFRESHED keeps the information whether we have needed to
2633 refresh replacements of the LHS and from which side of the assignments this
2637 load_assign_lhs_subreplacements (struct access *lacc, struct access *top_racc,
2638 HOST_WIDE_INT left_offset,
2639 gimple_stmt_iterator *old_gsi,
2640 gimple_stmt_iterator *new_gsi,
2641 enum unscalarized_data_handling *refreshed)
2643 location_t loc = gimple_location (gsi_stmt (*old_gsi));
2644 for (lacc = lacc->first_child; lacc; lacc = lacc->next_sibling)
2646 if (lacc->grp_to_be_replaced)
2648 struct access *racc;
2649 HOST_WIDE_INT offset = lacc->offset - left_offset + top_racc->offset;
2653 racc = find_access_in_subtree (top_racc, offset, lacc->size);
2654 if (racc && racc->grp_to_be_replaced)
2656 rhs = get_access_replacement (racc);
2657 if (!useless_type_conversion_p (lacc->type, racc->type))
2658 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, lacc->type, rhs);
2660 if (racc->grp_partial_lhs && lacc->grp_partial_lhs)
2661 rhs = force_gimple_operand_gsi (old_gsi, rhs, true, NULL_TREE,
2662 true, GSI_SAME_STMT);
2666 /* No suitable access on the right hand side, need to load from
2667 the aggregate. See if we have to update it first... */
2668 if (*refreshed == SRA_UDH_NONE)
2669 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2672 if (*refreshed == SRA_UDH_LEFT)
2673 rhs = build_ref_for_model (loc, lacc->base, lacc->offset, lacc,
2676 rhs = build_ref_for_model (loc, top_racc->base, offset, lacc,
2678 if (lacc->grp_partial_lhs)
2679 rhs = force_gimple_operand_gsi (new_gsi, rhs, true, NULL_TREE,
2680 false, GSI_NEW_STMT);
2683 stmt = gimple_build_assign (get_access_replacement (lacc), rhs);
2684 gsi_insert_after (new_gsi, stmt, GSI_NEW_STMT);
2685 gimple_set_location (stmt, loc);
2687 sra_stats.subreplacements++;
2689 else if (*refreshed == SRA_UDH_NONE
2690 && lacc->grp_read && !lacc->grp_covered)
2691 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2694 if (lacc->first_child)
2695 load_assign_lhs_subreplacements (lacc, top_racc, left_offset,
2696 old_gsi, new_gsi, refreshed);
2700 /* Result code for SRA assignment modification. */
2701 enum assignment_mod_result { SRA_AM_NONE, /* nothing done for the stmt */
2702 SRA_AM_MODIFIED, /* stmt changed but not
2704 SRA_AM_REMOVED }; /* stmt eliminated */
2706 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2707 to the assignment and GSI is the statement iterator pointing at it. Returns
2708 the same values as sra_modify_assign. */
2710 static enum assignment_mod_result
2711 sra_modify_constructor_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2713 tree lhs = gimple_assign_lhs (*stmt);
2717 acc = get_access_for_expr (lhs);
2721 loc = gimple_location (*stmt);
2722 if (VEC_length (constructor_elt,
2723 CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt))) > 0)
2725 /* I have never seen this code path trigger but if it can happen the
2726 following should handle it gracefully. */
2727 if (access_has_children_p (acc))
2728 generate_subtree_copies (acc->first_child, acc->base, 0, 0, 0, gsi,
2730 return SRA_AM_MODIFIED;
2733 if (acc->grp_covered)
2735 init_subtree_with_zero (acc, gsi, false, loc);
2736 unlink_stmt_vdef (*stmt);
2737 gsi_remove (gsi, true);
2738 return SRA_AM_REMOVED;
2742 init_subtree_with_zero (acc, gsi, true, loc);
2743 return SRA_AM_MODIFIED;
2747 /* Create and return a new suitable default definition SSA_NAME for RACC which
2748 is an access describing an uninitialized part of an aggregate that is being
2752 get_repl_default_def_ssa_name (struct access *racc)
2756 decl = get_unrenamed_access_replacement (racc);
2758 repl = gimple_default_def (cfun, decl);
2761 repl = make_ssa_name (decl, gimple_build_nop ());
2762 set_default_def (decl, repl);
2768 /* Return true if REF has a COMPONENT_REF with a bit-field field declaration
2772 contains_bitfld_comp_ref_p (const_tree ref)
2774 while (handled_component_p (ref))
2776 if (TREE_CODE (ref) == COMPONENT_REF
2777 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1)))
2779 ref = TREE_OPERAND (ref, 0);
2785 /* Return true if REF has an VIEW_CONVERT_EXPR or a COMPONENT_REF with a
2786 bit-field field declaration somewhere in it. */
2789 contains_vce_or_bfcref_p (const_tree ref)
2791 while (handled_component_p (ref))
2793 if (TREE_CODE (ref) == VIEW_CONVERT_EXPR
2794 || (TREE_CODE (ref) == COMPONENT_REF
2795 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))))
2797 ref = TREE_OPERAND (ref, 0);
2803 /* Examine both sides of the assignment statement pointed to by STMT, replace
2804 them with a scalare replacement if there is one and generate copying of
2805 replacements if scalarized aggregates have been used in the assignment. GSI
2806 is used to hold generated statements for type conversions and subtree
2809 static enum assignment_mod_result
2810 sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2812 struct access *lacc, *racc;
2814 bool modify_this_stmt = false;
2815 bool force_gimple_rhs = false;
2817 gimple_stmt_iterator orig_gsi = *gsi;
2819 if (!gimple_assign_single_p (*stmt))
2821 lhs = gimple_assign_lhs (*stmt);
2822 rhs = gimple_assign_rhs1 (*stmt);
2824 if (TREE_CODE (rhs) == CONSTRUCTOR)
2825 return sra_modify_constructor_assign (stmt, gsi);
2827 if (TREE_CODE (rhs) == REALPART_EXPR || TREE_CODE (lhs) == REALPART_EXPR
2828 || TREE_CODE (rhs) == IMAGPART_EXPR || TREE_CODE (lhs) == IMAGPART_EXPR
2829 || TREE_CODE (rhs) == BIT_FIELD_REF || TREE_CODE (lhs) == BIT_FIELD_REF)
2831 modify_this_stmt = sra_modify_expr (gimple_assign_rhs1_ptr (*stmt),
2833 modify_this_stmt |= sra_modify_expr (gimple_assign_lhs_ptr (*stmt),
2835 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
2838 lacc = get_access_for_expr (lhs);
2839 racc = get_access_for_expr (rhs);
2843 loc = gimple_location (*stmt);
2844 if (lacc && lacc->grp_to_be_replaced)
2846 lhs = get_access_replacement (lacc);
2847 gimple_assign_set_lhs (*stmt, lhs);
2848 modify_this_stmt = true;
2849 if (lacc->grp_partial_lhs)
2850 force_gimple_rhs = true;
2854 if (racc && racc->grp_to_be_replaced)
2856 rhs = get_access_replacement (racc);
2857 modify_this_stmt = true;
2858 if (racc->grp_partial_lhs)
2859 force_gimple_rhs = true;
2863 if (modify_this_stmt)
2865 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2867 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
2868 ??? This should move to fold_stmt which we simply should
2869 call after building a VIEW_CONVERT_EXPR here. */
2870 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
2871 && !contains_bitfld_comp_ref_p (lhs)
2872 && !access_has_children_p (lacc))
2874 lhs = build_ref_for_model (loc, lhs, 0, racc, gsi, false);
2875 gimple_assign_set_lhs (*stmt, lhs);
2877 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs))
2878 && !contains_vce_or_bfcref_p (rhs)
2879 && !access_has_children_p (racc))
2880 rhs = build_ref_for_model (loc, rhs, 0, lacc, gsi, false);
2882 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2884 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, TREE_TYPE (lhs),
2886 if (is_gimple_reg_type (TREE_TYPE (lhs))
2887 && TREE_CODE (lhs) != SSA_NAME)
2888 force_gimple_rhs = true;
2893 /* From this point on, the function deals with assignments in between
2894 aggregates when at least one has scalar reductions of some of its
2895 components. There are three possible scenarios: Both the LHS and RHS have
2896 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
2898 In the first case, we would like to load the LHS components from RHS
2899 components whenever possible. If that is not possible, we would like to
2900 read it directly from the RHS (after updating it by storing in it its own
2901 components). If there are some necessary unscalarized data in the LHS,
2902 those will be loaded by the original assignment too. If neither of these
2903 cases happen, the original statement can be removed. Most of this is done
2904 by load_assign_lhs_subreplacements.
2906 In the second case, we would like to store all RHS scalarized components
2907 directly into LHS and if they cover the aggregate completely, remove the
2908 statement too. In the third case, we want the LHS components to be loaded
2909 directly from the RHS (DSE will remove the original statement if it
2912 This is a bit complex but manageable when types match and when unions do
2913 not cause confusion in a way that we cannot really load a component of LHS
2914 from the RHS or vice versa (the access representing this level can have
2915 subaccesses that are accessible only through a different union field at a
2916 higher level - different from the one used in the examined expression).
2919 Therefore, I specially handle a fourth case, happening when there is a
2920 specific type cast or it is impossible to locate a scalarized subaccess on
2921 the other side of the expression. If that happens, I simply "refresh" the
2922 RHS by storing in it is scalarized components leave the original statement
2923 there to do the copying and then load the scalar replacements of the LHS.
2924 This is what the first branch does. */
2926 if (modify_this_stmt
2927 || gimple_has_volatile_ops (*stmt)
2928 || contains_vce_or_bfcref_p (rhs)
2929 || contains_vce_or_bfcref_p (lhs))
2931 if (access_has_children_p (racc))
2932 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
2933 gsi, false, false, loc);
2934 if (access_has_children_p (lacc))
2935 generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
2936 gsi, true, true, loc);
2937 sra_stats.separate_lhs_rhs_handling++;
2941 if (access_has_children_p (lacc)
2942 && access_has_children_p (racc)
2943 /* When an access represents an unscalarizable region, it usually
2944 represents accesses with variable offset and thus must not be used
2945 to generate new memory accesses. */
2946 && !lacc->grp_unscalarizable_region
2947 && !racc->grp_unscalarizable_region)
2949 gimple_stmt_iterator orig_gsi = *gsi;
2950 enum unscalarized_data_handling refreshed;
2952 if (lacc->grp_read && !lacc->grp_covered)
2953 refreshed = handle_unscalarized_data_in_subtree (racc, gsi);
2955 refreshed = SRA_UDH_NONE;
2957 load_assign_lhs_subreplacements (lacc, racc, lacc->offset,
2958 &orig_gsi, gsi, &refreshed);
2959 if (refreshed != SRA_UDH_RIGHT)
2962 unlink_stmt_vdef (*stmt);
2963 gsi_remove (&orig_gsi, true);
2964 sra_stats.deleted++;
2965 return SRA_AM_REMOVED;
2972 if (!racc->grp_to_be_replaced && !racc->grp_unscalarized_data)
2976 fprintf (dump_file, "Removing load: ");
2977 print_gimple_stmt (dump_file, *stmt, 0, 0);
2980 if (TREE_CODE (lhs) == SSA_NAME)
2982 rhs = get_repl_default_def_ssa_name (racc);
2983 if (!useless_type_conversion_p (TREE_TYPE (lhs),
2985 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR,
2986 TREE_TYPE (lhs), rhs);
2990 if (racc->first_child)
2991 generate_subtree_copies (racc->first_child, lhs,
2992 racc->offset, 0, 0, gsi,
2995 gcc_assert (*stmt == gsi_stmt (*gsi));
2996 unlink_stmt_vdef (*stmt);
2997 gsi_remove (gsi, true);
2998 sra_stats.deleted++;
2999 return SRA_AM_REMOVED;
3002 else if (racc->first_child)
3003 generate_subtree_copies (racc->first_child, lhs, racc->offset,
3004 0, 0, gsi, false, true, loc);
3006 if (access_has_children_p (lacc))
3007 generate_subtree_copies (lacc->first_child, rhs, lacc->offset,
3008 0, 0, gsi, true, true, loc);
3012 /* This gimplification must be done after generate_subtree_copies, lest we
3013 insert the subtree copies in the middle of the gimplified sequence. */
3014 if (force_gimple_rhs)
3015 rhs = force_gimple_operand_gsi (&orig_gsi, rhs, true, NULL_TREE,
3016 true, GSI_SAME_STMT);
3017 if (gimple_assign_rhs1 (*stmt) != rhs)
3019 modify_this_stmt = true;
3020 gimple_assign_set_rhs_from_tree (&orig_gsi, rhs);
3021 gcc_assert (*stmt == gsi_stmt (orig_gsi));
3024 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3027 /* Traverse the function body and all modifications as decided in
3028 analyze_all_variable_accesses. Return true iff the CFG has been
3032 sra_modify_function_body (void)
3034 bool cfg_changed = false;
3039 gimple_stmt_iterator gsi = gsi_start_bb (bb);
3040 while (!gsi_end_p (gsi))
3042 gimple stmt = gsi_stmt (gsi);
3043 enum assignment_mod_result assign_result;
3044 bool modified = false, deleted = false;
3048 switch (gimple_code (stmt))
3051 t = gimple_return_retval_ptr (stmt);
3052 if (*t != NULL_TREE)
3053 modified |= sra_modify_expr (t, &gsi, false);
3057 assign_result = sra_modify_assign (&stmt, &gsi);
3058 modified |= assign_result == SRA_AM_MODIFIED;
3059 deleted = assign_result == SRA_AM_REMOVED;
3063 /* Operands must be processed before the lhs. */
3064 for (i = 0; i < gimple_call_num_args (stmt); i++)
3066 t = gimple_call_arg_ptr (stmt, i);
3067 modified |= sra_modify_expr (t, &gsi, false);
3070 if (gimple_call_lhs (stmt))
3072 t = gimple_call_lhs_ptr (stmt);
3073 modified |= sra_modify_expr (t, &gsi, true);
3078 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
3080 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
3081 modified |= sra_modify_expr (t, &gsi, false);
3083 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
3085 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
3086 modified |= sra_modify_expr (t, &gsi, true);
3097 if (maybe_clean_eh_stmt (stmt)
3098 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
3109 /* Generate statements initializing scalar replacements of parts of function
3113 initialize_parameter_reductions (void)
3115 gimple_stmt_iterator gsi;
3116 gimple_seq seq = NULL;
3119 for (parm = DECL_ARGUMENTS (current_function_decl);
3121 parm = DECL_CHAIN (parm))
3123 VEC (access_p, heap) *access_vec;
3124 struct access *access;
3126 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3128 access_vec = get_base_access_vector (parm);
3134 seq = gimple_seq_alloc ();
3135 gsi = gsi_start (seq);
3138 for (access = VEC_index (access_p, access_vec, 0);
3140 access = access->next_grp)
3141 generate_subtree_copies (access, parm, 0, 0, 0, &gsi, true, true,
3142 EXPR_LOCATION (parm));
3146 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR), seq);
3149 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
3150 it reveals there are components of some aggregates to be scalarized, it runs
3151 the required transformations. */
3153 perform_intra_sra (void)
3158 if (!find_var_candidates ())
3161 if (!scan_function ())
3164 if (!analyze_all_variable_accesses ())
3167 if (sra_modify_function_body ())
3168 ret = TODO_update_ssa | TODO_cleanup_cfg;
3170 ret = TODO_update_ssa;
3171 initialize_parameter_reductions ();
3173 statistics_counter_event (cfun, "Scalar replacements created",
3174 sra_stats.replacements);
3175 statistics_counter_event (cfun, "Modified expressions", sra_stats.exprs);
3176 statistics_counter_event (cfun, "Subtree copy stmts",
3177 sra_stats.subtree_copies);
3178 statistics_counter_event (cfun, "Subreplacement stmts",
3179 sra_stats.subreplacements);
3180 statistics_counter_event (cfun, "Deleted stmts", sra_stats.deleted);
3181 statistics_counter_event (cfun, "Separate LHS and RHS handling",
3182 sra_stats.separate_lhs_rhs_handling);
3185 sra_deinitialize ();
3189 /* Perform early intraprocedural SRA. */
3191 early_intra_sra (void)
3193 sra_mode = SRA_MODE_EARLY_INTRA;
3194 return perform_intra_sra ();
3197 /* Perform "late" intraprocedural SRA. */
3199 late_intra_sra (void)
3201 sra_mode = SRA_MODE_INTRA;
3202 return perform_intra_sra ();
3207 gate_intra_sra (void)
3209 return flag_tree_sra != 0 && dbg_cnt (tree_sra);
3213 struct gimple_opt_pass pass_sra_early =
3218 gate_intra_sra, /* gate */
3219 early_intra_sra, /* execute */
3222 0, /* static_pass_number */
3223 TV_TREE_SRA, /* tv_id */
3224 PROP_cfg | PROP_ssa, /* properties_required */
3225 0, /* properties_provided */
3226 0, /* properties_destroyed */
3227 0, /* todo_flags_start */
3231 | TODO_verify_ssa /* todo_flags_finish */
3235 struct gimple_opt_pass pass_sra =
3240 gate_intra_sra, /* gate */
3241 late_intra_sra, /* execute */
3244 0, /* static_pass_number */
3245 TV_TREE_SRA, /* tv_id */
3246 PROP_cfg | PROP_ssa, /* properties_required */
3247 0, /* properties_provided */
3248 0, /* properties_destroyed */
3249 TODO_update_address_taken, /* todo_flags_start */
3253 | TODO_verify_ssa /* todo_flags_finish */
3258 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3262 is_unused_scalar_param (tree parm)
3265 return (is_gimple_reg (parm)
3266 && (!(name = gimple_default_def (cfun, parm))
3267 || has_zero_uses (name)));
3270 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3271 examine whether there are any direct or otherwise infeasible ones. If so,
3272 return true, otherwise return false. PARM must be a gimple register with a
3273 non-NULL default definition. */
3276 ptr_parm_has_direct_uses (tree parm)
3278 imm_use_iterator ui;
3280 tree name = gimple_default_def (cfun, parm);
3283 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
3286 use_operand_p use_p;
3288 if (is_gimple_debug (stmt))
3291 /* Valid uses include dereferences on the lhs and the rhs. */
3292 if (gimple_has_lhs (stmt))
3294 tree lhs = gimple_get_lhs (stmt);
3295 while (handled_component_p (lhs))
3296 lhs = TREE_OPERAND (lhs, 0);
3297 if (TREE_CODE (lhs) == MEM_REF
3298 && TREE_OPERAND (lhs, 0) == name
3299 && integer_zerop (TREE_OPERAND (lhs, 1))
3300 && types_compatible_p (TREE_TYPE (lhs),
3301 TREE_TYPE (TREE_TYPE (name)))
3302 && !TREE_THIS_VOLATILE (lhs))
3305 if (gimple_assign_single_p (stmt))
3307 tree rhs = gimple_assign_rhs1 (stmt);
3308 while (handled_component_p (rhs))
3309 rhs = TREE_OPERAND (rhs, 0);
3310 if (TREE_CODE (rhs) == MEM_REF
3311 && TREE_OPERAND (rhs, 0) == name
3312 && integer_zerop (TREE_OPERAND (rhs, 1))
3313 && types_compatible_p (TREE_TYPE (rhs),
3314 TREE_TYPE (TREE_TYPE (name)))
3315 && !TREE_THIS_VOLATILE (rhs))
3318 else if (is_gimple_call (stmt))
3321 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3323 tree arg = gimple_call_arg (stmt, i);
3324 while (handled_component_p (arg))
3325 arg = TREE_OPERAND (arg, 0);
3326 if (TREE_CODE (arg) == MEM_REF
3327 && TREE_OPERAND (arg, 0) == name
3328 && integer_zerop (TREE_OPERAND (arg, 1))
3329 && types_compatible_p (TREE_TYPE (arg),
3330 TREE_TYPE (TREE_TYPE (name)))
3331 && !TREE_THIS_VOLATILE (arg))
3336 /* If the number of valid uses does not match the number of
3337 uses in this stmt there is an unhandled use. */
3338 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
3345 BREAK_FROM_IMM_USE_STMT (ui);
3351 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3352 them in candidate_bitmap. Note that these do not necessarily include
3353 parameter which are unused and thus can be removed. Return true iff any
3354 such candidate has been found. */
3357 find_param_candidates (void)
3363 for (parm = DECL_ARGUMENTS (current_function_decl);
3365 parm = DECL_CHAIN (parm))
3367 tree type = TREE_TYPE (parm);
3371 if (TREE_THIS_VOLATILE (parm)
3372 || TREE_ADDRESSABLE (parm)
3373 || (!is_gimple_reg_type (type) && is_va_list_type (type)))
3376 if (is_unused_scalar_param (parm))
3382 if (POINTER_TYPE_P (type))
3384 type = TREE_TYPE (type);
3386 if (TREE_CODE (type) == FUNCTION_TYPE
3387 || TYPE_VOLATILE (type)
3388 || (TREE_CODE (type) == ARRAY_TYPE
3389 && TYPE_NONALIASED_COMPONENT (type))
3390 || !is_gimple_reg (parm)
3391 || is_va_list_type (type)
3392 || ptr_parm_has_direct_uses (parm))
3395 else if (!AGGREGATE_TYPE_P (type))
3398 if (!COMPLETE_TYPE_P (type)
3399 || !host_integerp (TYPE_SIZE (type), 1)
3400 || tree_low_cst (TYPE_SIZE (type), 1) == 0
3401 || (AGGREGATE_TYPE_P (type)
3402 && type_internals_preclude_sra_p (type)))
3405 bitmap_set_bit (candidate_bitmap, DECL_UID (parm));
3407 if (dump_file && (dump_flags & TDF_DETAILS))
3409 fprintf (dump_file, "Candidate (%d): ", DECL_UID (parm));
3410 print_generic_expr (dump_file, parm, 0);
3411 fprintf (dump_file, "\n");
3415 func_param_count = count;
3419 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3423 mark_maybe_modified (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef ATTRIBUTE_UNUSED,
3426 struct access *repr = (struct access *) data;
3428 repr->grp_maybe_modified = 1;
3432 /* Analyze what representatives (in linked lists accessible from
3433 REPRESENTATIVES) can be modified by side effects of statements in the
3434 current function. */
3437 analyze_modified_params (VEC (access_p, heap) *representatives)
3441 for (i = 0; i < func_param_count; i++)
3443 struct access *repr;
3445 for (repr = VEC_index (access_p, representatives, i);
3447 repr = repr->next_grp)
3449 struct access *access;
3453 if (no_accesses_p (repr))
3455 if (!POINTER_TYPE_P (TREE_TYPE (repr->base))
3456 || repr->grp_maybe_modified)
3459 ao_ref_init (&ar, repr->expr);
3460 visited = BITMAP_ALLOC (NULL);
3461 for (access = repr; access; access = access->next_sibling)
3463 /* All accesses are read ones, otherwise grp_maybe_modified would
3464 be trivially set. */
3465 walk_aliased_vdefs (&ar, gimple_vuse (access->stmt),
3466 mark_maybe_modified, repr, &visited);
3467 if (repr->grp_maybe_modified)
3470 BITMAP_FREE (visited);
3475 /* Propagate distances in bb_dereferences in the opposite direction than the
3476 control flow edges, in each step storing the maximum of the current value
3477 and the minimum of all successors. These steps are repeated until the table
3478 stabilizes. Note that BBs which might terminate the functions (according to
3479 final_bbs bitmap) never updated in this way. */
3482 propagate_dereference_distances (void)
3484 VEC (basic_block, heap) *queue;
3487 queue = VEC_alloc (basic_block, heap, last_basic_block_for_function (cfun));
3488 VEC_quick_push (basic_block, queue, ENTRY_BLOCK_PTR);
3491 VEC_quick_push (basic_block, queue, bb);
3495 while (!VEC_empty (basic_block, queue))
3499 bool change = false;
3502 bb = VEC_pop (basic_block, queue);
3505 if (bitmap_bit_p (final_bbs, bb->index))
3508 for (i = 0; i < func_param_count; i++)
3510 int idx = bb->index * func_param_count + i;
3512 HOST_WIDE_INT inh = 0;
3514 FOR_EACH_EDGE (e, ei, bb->succs)
3516 int succ_idx = e->dest->index * func_param_count + i;
3518 if (e->src == EXIT_BLOCK_PTR)
3524 inh = bb_dereferences [succ_idx];
3526 else if (bb_dereferences [succ_idx] < inh)
3527 inh = bb_dereferences [succ_idx];
3530 if (!first && bb_dereferences[idx] < inh)
3532 bb_dereferences[idx] = inh;
3537 if (change && !bitmap_bit_p (final_bbs, bb->index))
3538 FOR_EACH_EDGE (e, ei, bb->preds)
3543 e->src->aux = e->src;
3544 VEC_quick_push (basic_block, queue, e->src);
3548 VEC_free (basic_block, heap, queue);
3551 /* Dump a dereferences TABLE with heading STR to file F. */
3554 dump_dereferences_table (FILE *f, const char *str, HOST_WIDE_INT *table)
3558 fprintf (dump_file, str);
3559 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
3561 fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index));
3562 if (bb != EXIT_BLOCK_PTR)
3565 for (i = 0; i < func_param_count; i++)
3567 int idx = bb->index * func_param_count + i;
3568 fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", table[idx]);
3573 fprintf (dump_file, "\n");
3576 /* Determine what (parts of) parameters passed by reference that are not
3577 assigned to are not certainly dereferenced in this function and thus the
3578 dereferencing cannot be safely moved to the caller without potentially
3579 introducing a segfault. Mark such REPRESENTATIVES as
3580 grp_not_necessarilly_dereferenced.
3582 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3583 part is calculated rather than simple booleans are calculated for each
3584 pointer parameter to handle cases when only a fraction of the whole
3585 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3588 The maximum dereference distances for each pointer parameter and BB are
3589 already stored in bb_dereference. This routine simply propagates these
3590 values upwards by propagate_dereference_distances and then compares the
3591 distances of individual parameters in the ENTRY BB to the equivalent
3592 distances of each representative of a (fraction of a) parameter. */
3595 analyze_caller_dereference_legality (VEC (access_p, heap) *representatives)
3599 if (dump_file && (dump_flags & TDF_DETAILS))
3600 dump_dereferences_table (dump_file,
3601 "Dereference table before propagation:\n",
3604 propagate_dereference_distances ();
3606 if (dump_file && (dump_flags & TDF_DETAILS))
3607 dump_dereferences_table (dump_file,
3608 "Dereference table after propagation:\n",
3611 for (i = 0; i < func_param_count; i++)
3613 struct access *repr = VEC_index (access_p, representatives, i);
3614 int idx = ENTRY_BLOCK_PTR->index * func_param_count + i;
3616 if (!repr || no_accesses_p (repr))
3621 if ((repr->offset + repr->size) > bb_dereferences[idx])
3622 repr->grp_not_necessarilly_dereferenced = 1;
3623 repr = repr->next_grp;
3629 /* Return the representative access for the parameter declaration PARM if it is
3630 a scalar passed by reference which is not written to and the pointer value
3631 is not used directly. Thus, if it is legal to dereference it in the caller
3632 and we can rule out modifications through aliases, such parameter should be
3633 turned into one passed by value. Return NULL otherwise. */
3635 static struct access *
3636 unmodified_by_ref_scalar_representative (tree parm)
3638 int i, access_count;
3639 struct access *repr;
3640 VEC (access_p, heap) *access_vec;
3642 access_vec = get_base_access_vector (parm);
3643 gcc_assert (access_vec);
3644 repr = VEC_index (access_p, access_vec, 0);
3647 repr->group_representative = repr;
3649 access_count = VEC_length (access_p, access_vec);
3650 for (i = 1; i < access_count; i++)
3652 struct access *access = VEC_index (access_p, access_vec, i);
3655 access->group_representative = repr;
3656 access->next_sibling = repr->next_sibling;
3657 repr->next_sibling = access;
3661 repr->grp_scalar_ptr = 1;
3665 /* Return true iff this access precludes IPA-SRA of the parameter it is
3669 access_precludes_ipa_sra_p (struct access *access)
3671 /* Avoid issues such as the second simple testcase in PR 42025. The problem
3672 is incompatible assign in a call statement (and possibly even in asm
3673 statements). This can be relaxed by using a new temporary but only for
3674 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
3675 intraprocedural SRA we deal with this by keeping the old aggregate around,
3676 something we cannot do in IPA-SRA.) */
3678 && (is_gimple_call (access->stmt)
3679 || gimple_code (access->stmt) == GIMPLE_ASM))
3682 if (STRICT_ALIGNMENT
3683 && tree_non_aligned_mem_p (access->expr, TYPE_ALIGN (access->type)))
3690 /* Sort collected accesses for parameter PARM, identify representatives for
3691 each accessed region and link them together. Return NULL if there are
3692 different but overlapping accesses, return the special ptr value meaning
3693 there are no accesses for this parameter if that is the case and return the
3694 first representative otherwise. Set *RO_GRP if there is a group of accesses
3695 with only read (i.e. no write) accesses. */
3697 static struct access *
3698 splice_param_accesses (tree parm, bool *ro_grp)
3700 int i, j, access_count, group_count;
3701 int agg_size, total_size = 0;
3702 struct access *access, *res, **prev_acc_ptr = &res;
3703 VEC (access_p, heap) *access_vec;
3705 access_vec = get_base_access_vector (parm);
3707 return &no_accesses_representant;
3708 access_count = VEC_length (access_p, access_vec);
3710 VEC_qsort (access_p, access_vec, compare_access_positions);
3715 while (i < access_count)
3719 access = VEC_index (access_p, access_vec, i);
3720 modification = access->write;
3721 if (access_precludes_ipa_sra_p (access))
3723 a1_alias_type = reference_alias_ptr_type (access->expr);
3725 /* Access is about to become group representative unless we find some
3726 nasty overlap which would preclude us from breaking this parameter
3730 while (j < access_count)
3732 struct access *ac2 = VEC_index (access_p, access_vec, j);
3733 if (ac2->offset != access->offset)
3735 /* All or nothing law for parameters. */
3736 if (access->offset + access->size > ac2->offset)
3741 else if (ac2->size != access->size)
3744 if (access_precludes_ipa_sra_p (ac2)
3745 || (ac2->type != access->type
3746 && (TREE_ADDRESSABLE (ac2->type)
3747 || TREE_ADDRESSABLE (access->type)))
3748 || (reference_alias_ptr_type (ac2->expr) != a1_alias_type))
3751 modification |= ac2->write;
3752 ac2->group_representative = access;
3753 ac2->next_sibling = access->next_sibling;
3754 access->next_sibling = ac2;
3759 access->grp_maybe_modified = modification;
3762 *prev_acc_ptr = access;
3763 prev_acc_ptr = &access->next_grp;
3764 total_size += access->size;
3768 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3769 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3771 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3772 if (total_size >= agg_size)
3775 gcc_assert (group_count > 0);
3779 /* Decide whether parameters with representative accesses given by REPR should
3780 be reduced into components. */
3783 decide_one_param_reduction (struct access *repr)
3785 int total_size, cur_parm_size, agg_size, new_param_count, parm_size_limit;
3790 cur_parm_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3791 gcc_assert (cur_parm_size > 0);
3793 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3796 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3801 agg_size = cur_parm_size;
3807 fprintf (dump_file, "Evaluating PARAM group sizes for ");
3808 print_generic_expr (dump_file, parm, 0);
3809 fprintf (dump_file, " (UID: %u): \n", DECL_UID (parm));
3810 for (acc = repr; acc; acc = acc->next_grp)
3811 dump_access (dump_file, acc, true);
3815 new_param_count = 0;
3817 for (; repr; repr = repr->next_grp)
3819 gcc_assert (parm == repr->base);
3821 /* Taking the address of a non-addressable field is verboten. */
3822 if (by_ref && repr->non_addressable)
3825 if (!by_ref || (!repr->grp_maybe_modified
3826 && !repr->grp_not_necessarilly_dereferenced))
3827 total_size += repr->size;
3829 total_size += cur_parm_size;
3834 gcc_assert (new_param_count > 0);
3836 if (optimize_function_for_size_p (cfun))
3837 parm_size_limit = cur_parm_size;
3839 parm_size_limit = (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR)
3842 if (total_size < agg_size
3843 && total_size <= parm_size_limit)
3846 fprintf (dump_file, " ....will be split into %i components\n",
3848 return new_param_count;
3854 /* The order of the following enums is important, we need to do extra work for
3855 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
3856 enum ipa_splicing_result { NO_GOOD_ACCESS, UNUSED_PARAMS, BY_VAL_ACCESSES,
3857 MODIF_BY_REF_ACCESSES, UNMODIF_BY_REF_ACCESSES };
3859 /* Identify representatives of all accesses to all candidate parameters for
3860 IPA-SRA. Return result based on what representatives have been found. */
3862 static enum ipa_splicing_result
3863 splice_all_param_accesses (VEC (access_p, heap) **representatives)
3865 enum ipa_splicing_result result = NO_GOOD_ACCESS;
3867 struct access *repr;
3869 *representatives = VEC_alloc (access_p, heap, func_param_count);
3871 for (parm = DECL_ARGUMENTS (current_function_decl);
3873 parm = DECL_CHAIN (parm))
3875 if (is_unused_scalar_param (parm))
3877 VEC_quick_push (access_p, *representatives,
3878 &no_accesses_representant);
3879 if (result == NO_GOOD_ACCESS)
3880 result = UNUSED_PARAMS;
3882 else if (POINTER_TYPE_P (TREE_TYPE (parm))
3883 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm)))
3884 && bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3886 repr = unmodified_by_ref_scalar_representative (parm);
3887 VEC_quick_push (access_p, *representatives, repr);
3889 result = UNMODIF_BY_REF_ACCESSES;
3891 else if (bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3893 bool ro_grp = false;
3894 repr = splice_param_accesses (parm, &ro_grp);
3895 VEC_quick_push (access_p, *representatives, repr);
3897 if (repr && !no_accesses_p (repr))
3899 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3902 result = UNMODIF_BY_REF_ACCESSES;
3903 else if (result < MODIF_BY_REF_ACCESSES)
3904 result = MODIF_BY_REF_ACCESSES;
3906 else if (result < BY_VAL_ACCESSES)
3907 result = BY_VAL_ACCESSES;
3909 else if (no_accesses_p (repr) && (result == NO_GOOD_ACCESS))
3910 result = UNUSED_PARAMS;
3913 VEC_quick_push (access_p, *representatives, NULL);
3916 if (result == NO_GOOD_ACCESS)
3918 VEC_free (access_p, heap, *representatives);
3919 *representatives = NULL;
3920 return NO_GOOD_ACCESS;
3926 /* Return the index of BASE in PARMS. Abort if it is not found. */
3929 get_param_index (tree base, VEC(tree, heap) *parms)
3933 len = VEC_length (tree, parms);
3934 for (i = 0; i < len; i++)
3935 if (VEC_index (tree, parms, i) == base)
3940 /* Convert the decisions made at the representative level into compact
3941 parameter adjustments. REPRESENTATIVES are pointers to first
3942 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
3943 final number of adjustments. */
3945 static ipa_parm_adjustment_vec
3946 turn_representatives_into_adjustments (VEC (access_p, heap) *representatives,
3947 int adjustments_count)
3949 VEC (tree, heap) *parms;
3950 ipa_parm_adjustment_vec adjustments;
3954 gcc_assert (adjustments_count > 0);
3955 parms = ipa_get_vector_of_formal_parms (current_function_decl);
3956 adjustments = VEC_alloc (ipa_parm_adjustment_t, heap, adjustments_count);
3957 parm = DECL_ARGUMENTS (current_function_decl);
3958 for (i = 0; i < func_param_count; i++, parm = DECL_CHAIN (parm))
3960 struct access *repr = VEC_index (access_p, representatives, i);
3962 if (!repr || no_accesses_p (repr))
3964 struct ipa_parm_adjustment *adj;
3966 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
3967 memset (adj, 0, sizeof (*adj));
3968 adj->base_index = get_param_index (parm, parms);
3971 adj->copy_param = 1;
3973 adj->remove_param = 1;
3977 struct ipa_parm_adjustment *adj;
3978 int index = get_param_index (parm, parms);
3980 for (; repr; repr = repr->next_grp)
3982 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
3983 memset (adj, 0, sizeof (*adj));
3984 gcc_assert (repr->base == parm);
3985 adj->base_index = index;
3986 adj->base = repr->base;
3987 adj->type = repr->type;
3988 adj->alias_ptr_type = reference_alias_ptr_type (repr->expr);
3989 adj->offset = repr->offset;
3990 adj->by_ref = (POINTER_TYPE_P (TREE_TYPE (repr->base))
3991 && (repr->grp_maybe_modified
3992 || repr->grp_not_necessarilly_dereferenced));
3997 VEC_free (tree, heap, parms);
4001 /* Analyze the collected accesses and produce a plan what to do with the
4002 parameters in the form of adjustments, NULL meaning nothing. */
4004 static ipa_parm_adjustment_vec
4005 analyze_all_param_acesses (void)
4007 enum ipa_splicing_result repr_state;
4008 bool proceed = false;
4009 int i, adjustments_count = 0;
4010 VEC (access_p, heap) *representatives;
4011 ipa_parm_adjustment_vec adjustments;
4013 repr_state = splice_all_param_accesses (&representatives);
4014 if (repr_state == NO_GOOD_ACCESS)
4017 /* If there are any parameters passed by reference which are not modified
4018 directly, we need to check whether they can be modified indirectly. */
4019 if (repr_state == UNMODIF_BY_REF_ACCESSES)
4021 analyze_caller_dereference_legality (representatives);
4022 analyze_modified_params (representatives);
4025 for (i = 0; i < func_param_count; i++)
4027 struct access *repr = VEC_index (access_p, representatives, i);
4029 if (repr && !no_accesses_p (repr))
4031 if (repr->grp_scalar_ptr)
4033 adjustments_count++;
4034 if (repr->grp_not_necessarilly_dereferenced
4035 || repr->grp_maybe_modified)
4036 VEC_replace (access_p, representatives, i, NULL);
4040 sra_stats.scalar_by_ref_to_by_val++;
4045 int new_components = decide_one_param_reduction (repr);
4047 if (new_components == 0)
4049 VEC_replace (access_p, representatives, i, NULL);
4050 adjustments_count++;
4054 adjustments_count += new_components;
4055 sra_stats.aggregate_params_reduced++;
4056 sra_stats.param_reductions_created += new_components;
4063 if (no_accesses_p (repr))
4066 sra_stats.deleted_unused_parameters++;
4068 adjustments_count++;
4072 if (!proceed && dump_file)
4073 fprintf (dump_file, "NOT proceeding to change params.\n");
4076 adjustments = turn_representatives_into_adjustments (representatives,
4081 VEC_free (access_p, heap, representatives);
4085 /* If a parameter replacement identified by ADJ does not yet exist in the form
4086 of declaration, create it and record it, otherwise return the previously
4090 get_replaced_param_substitute (struct ipa_parm_adjustment *adj)
4093 if (!adj->new_ssa_base)
4095 char *pretty_name = make_fancy_name (adj->base);
4097 repl = create_tmp_reg (TREE_TYPE (adj->base), "ISR");
4098 DECL_NAME (repl) = get_identifier (pretty_name);
4099 obstack_free (&name_obstack, pretty_name);
4102 add_referenced_var (repl);
4103 adj->new_ssa_base = repl;
4106 repl = adj->new_ssa_base;
4110 /* Find the first adjustment for a particular parameter BASE in a vector of
4111 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
4114 static struct ipa_parm_adjustment *
4115 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments, tree base)
4119 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4120 for (i = 0; i < len; i++)
4122 struct ipa_parm_adjustment *adj;
4124 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4125 if (!adj->copy_param && adj->base == base)
4132 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
4133 removed because its value is not used, replace the SSA_NAME with a one
4134 relating to a created VAR_DECL together all of its uses and return true.
4135 ADJUSTMENTS is a pointer to an adjustments vector. */
4138 replace_removed_params_ssa_names (gimple stmt,
4139 ipa_parm_adjustment_vec adjustments)
4141 struct ipa_parm_adjustment *adj;
4142 tree lhs, decl, repl, name;
4144 if (gimple_code (stmt) == GIMPLE_PHI)
4145 lhs = gimple_phi_result (stmt);
4146 else if (is_gimple_assign (stmt))
4147 lhs = gimple_assign_lhs (stmt);
4148 else if (is_gimple_call (stmt))
4149 lhs = gimple_call_lhs (stmt);
4153 if (TREE_CODE (lhs) != SSA_NAME)
4155 decl = SSA_NAME_VAR (lhs);
4156 if (TREE_CODE (decl) != PARM_DECL)
4159 adj = get_adjustment_for_base (adjustments, decl);
4163 repl = get_replaced_param_substitute (adj);
4164 name = make_ssa_name (repl, stmt);
4168 fprintf (dump_file, "replacing an SSA name of a removed param ");
4169 print_generic_expr (dump_file, lhs, 0);
4170 fprintf (dump_file, " with ");
4171 print_generic_expr (dump_file, name, 0);
4172 fprintf (dump_file, "\n");
4175 if (is_gimple_assign (stmt))
4176 gimple_assign_set_lhs (stmt, name);
4177 else if (is_gimple_call (stmt))
4178 gimple_call_set_lhs (stmt, name);
4180 gimple_phi_set_result (stmt, name);
4182 replace_uses_by (lhs, name);
4183 release_ssa_name (lhs);
4187 /* If the expression *EXPR should be replaced by a reduction of a parameter, do
4188 so. ADJUSTMENTS is a pointer to a vector of adjustments. CONVERT
4189 specifies whether the function should care about type incompatibility the
4190 current and new expressions. If it is false, the function will leave
4191 incompatibility issues to the caller. Return true iff the expression
4195 sra_ipa_modify_expr (tree *expr, bool convert,
4196 ipa_parm_adjustment_vec adjustments)
4199 struct ipa_parm_adjustment *adj, *cand = NULL;
4200 HOST_WIDE_INT offset, size, max_size;
4203 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4205 if (TREE_CODE (*expr) == BIT_FIELD_REF
4206 || TREE_CODE (*expr) == IMAGPART_EXPR
4207 || TREE_CODE (*expr) == REALPART_EXPR)
4209 expr = &TREE_OPERAND (*expr, 0);
4213 base = get_ref_base_and_extent (*expr, &offset, &size, &max_size);
4214 if (!base || size == -1 || max_size == -1)
4217 if (TREE_CODE (base) == MEM_REF)
4219 offset += mem_ref_offset (base).low * BITS_PER_UNIT;
4220 base = TREE_OPERAND (base, 0);
4223 base = get_ssa_base_param (base);
4224 if (!base || TREE_CODE (base) != PARM_DECL)
4227 for (i = 0; i < len; i++)
4229 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4231 if (adj->base == base &&
4232 (adj->offset == offset || adj->remove_param))
4238 if (!cand || cand->copy_param || cand->remove_param)
4242 src = build_simple_mem_ref (cand->reduction);
4244 src = cand->reduction;
4246 if (dump_file && (dump_flags & TDF_DETAILS))
4248 fprintf (dump_file, "About to replace expr ");
4249 print_generic_expr (dump_file, *expr, 0);
4250 fprintf (dump_file, " with ");
4251 print_generic_expr (dump_file, src, 0);
4252 fprintf (dump_file, "\n");
4255 if (convert && !useless_type_conversion_p (TREE_TYPE (*expr), cand->type))
4257 tree vce = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (*expr), src);
4265 /* If the statement pointed to by STMT_PTR contains any expressions that need
4266 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4267 potential type incompatibilities (GSI is used to accommodate conversion
4268 statements and must point to the statement). Return true iff the statement
4272 sra_ipa_modify_assign (gimple *stmt_ptr, gimple_stmt_iterator *gsi,
4273 ipa_parm_adjustment_vec adjustments)
4275 gimple stmt = *stmt_ptr;
4276 tree *lhs_p, *rhs_p;
4279 if (!gimple_assign_single_p (stmt))
4282 rhs_p = gimple_assign_rhs1_ptr (stmt);
4283 lhs_p = gimple_assign_lhs_ptr (stmt);
4285 any = sra_ipa_modify_expr (rhs_p, false, adjustments);
4286 any |= sra_ipa_modify_expr (lhs_p, false, adjustments);
4289 tree new_rhs = NULL_TREE;
4291 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p), TREE_TYPE (*rhs_p)))
4293 if (TREE_CODE (*rhs_p) == CONSTRUCTOR)
4295 /* V_C_Es of constructors can cause trouble (PR 42714). */
4296 if (is_gimple_reg_type (TREE_TYPE (*lhs_p)))
4297 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
4299 *rhs_p = build_constructor (TREE_TYPE (*lhs_p), 0);
4302 new_rhs = fold_build1_loc (gimple_location (stmt),
4303 VIEW_CONVERT_EXPR, TREE_TYPE (*lhs_p),
4306 else if (REFERENCE_CLASS_P (*rhs_p)
4307 && is_gimple_reg_type (TREE_TYPE (*lhs_p))
4308 && !is_gimple_reg (*lhs_p))
4309 /* This can happen when an assignment in between two single field
4310 structures is turned into an assignment in between two pointers to
4311 scalars (PR 42237). */
4316 tree tmp = force_gimple_operand_gsi (gsi, new_rhs, true, NULL_TREE,
4317 true, GSI_SAME_STMT);
4319 gimple_assign_set_rhs_from_tree (gsi, tmp);
4328 /* Traverse the function body and all modifications as described in
4329 ADJUSTMENTS. Return true iff the CFG has been changed. */
4332 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments)
4334 bool cfg_changed = false;
4339 gimple_stmt_iterator gsi;
4341 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4342 replace_removed_params_ssa_names (gsi_stmt (gsi), adjustments);
4344 gsi = gsi_start_bb (bb);
4345 while (!gsi_end_p (gsi))
4347 gimple stmt = gsi_stmt (gsi);
4348 bool modified = false;
4352 switch (gimple_code (stmt))
4355 t = gimple_return_retval_ptr (stmt);
4356 if (*t != NULL_TREE)
4357 modified |= sra_ipa_modify_expr (t, true, adjustments);
4361 modified |= sra_ipa_modify_assign (&stmt, &gsi, adjustments);
4362 modified |= replace_removed_params_ssa_names (stmt, adjustments);
4366 /* Operands must be processed before the lhs. */
4367 for (i = 0; i < gimple_call_num_args (stmt); i++)
4369 t = gimple_call_arg_ptr (stmt, i);
4370 modified |= sra_ipa_modify_expr (t, true, adjustments);
4373 if (gimple_call_lhs (stmt))
4375 t = gimple_call_lhs_ptr (stmt);
4376 modified |= sra_ipa_modify_expr (t, false, adjustments);
4377 modified |= replace_removed_params_ssa_names (stmt,
4383 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
4385 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
4386 modified |= sra_ipa_modify_expr (t, true, adjustments);
4388 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
4390 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
4391 modified |= sra_ipa_modify_expr (t, false, adjustments);
4402 if (maybe_clean_eh_stmt (stmt)
4403 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
4413 /* Call gimple_debug_bind_reset_value on all debug statements describing
4414 gimple register parameters that are being removed or replaced. */
4417 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments)
4421 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4422 for (i = 0; i < len; i++)
4424 struct ipa_parm_adjustment *adj;
4425 imm_use_iterator ui;
4429 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4430 if (adj->copy_param || !is_gimple_reg (adj->base))
4432 name = gimple_default_def (cfun, adj->base);
4435 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
4437 /* All other users must have been removed by
4438 ipa_sra_modify_function_body. */
4439 gcc_assert (is_gimple_debug (stmt));
4440 gimple_debug_bind_reset_value (stmt);
4446 /* Return true iff all callers have at least as many actual arguments as there
4447 are formal parameters in the current function. */
4450 all_callers_have_enough_arguments_p (struct cgraph_node *node)
4452 struct cgraph_edge *cs;
4453 for (cs = node->callers; cs; cs = cs->next_caller)
4454 if (!callsite_has_enough_arguments_p (cs->call_stmt))
4461 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4464 convert_callers (struct cgraph_node *node, tree old_decl,
4465 ipa_parm_adjustment_vec adjustments)
4467 tree old_cur_fndecl = current_function_decl;
4468 struct cgraph_edge *cs;
4469 basic_block this_block;
4470 bitmap recomputed_callers = BITMAP_ALLOC (NULL);
4472 for (cs = node->callers; cs; cs = cs->next_caller)
4474 current_function_decl = cs->caller->decl;
4475 push_cfun (DECL_STRUCT_FUNCTION (cs->caller->decl));
4478 fprintf (dump_file, "Adjusting call (%i -> %i) %s -> %s\n",
4479 cs->caller->uid, cs->callee->uid,
4480 cgraph_node_name (cs->caller),
4481 cgraph_node_name (cs->callee));
4483 ipa_modify_call_arguments (cs, cs->call_stmt, adjustments);
4488 for (cs = node->callers; cs; cs = cs->next_caller)
4489 if (bitmap_set_bit (recomputed_callers, cs->caller->uid)
4490 && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (cs->caller->decl)))
4491 compute_inline_parameters (cs->caller);
4492 BITMAP_FREE (recomputed_callers);
4494 current_function_decl = old_cur_fndecl;
4496 if (!encountered_recursive_call)
4499 FOR_EACH_BB (this_block)
4501 gimple_stmt_iterator gsi;
4503 for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
4505 gimple stmt = gsi_stmt (gsi);
4507 if (gimple_code (stmt) != GIMPLE_CALL)
4509 call_fndecl = gimple_call_fndecl (stmt);
4510 if (call_fndecl == old_decl)
4513 fprintf (dump_file, "Adjusting recursive call");
4514 gimple_call_set_fndecl (stmt, node->decl);
4515 ipa_modify_call_arguments (NULL, stmt, adjustments);
4523 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4524 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4527 modify_function (struct cgraph_node *node, ipa_parm_adjustment_vec adjustments)
4529 struct cgraph_node *new_node;
4530 struct cgraph_edge *cs;
4532 VEC (cgraph_edge_p, heap) * redirect_callers;
4536 for (cs = node->callers; cs != NULL; cs = cs->next_caller)
4538 redirect_callers = VEC_alloc (cgraph_edge_p, heap, node_callers);
4539 for (cs = node->callers; cs != NULL; cs = cs->next_caller)
4540 VEC_quick_push (cgraph_edge_p, redirect_callers, cs);
4542 rebuild_cgraph_edges ();
4544 current_function_decl = NULL_TREE;
4546 new_node = cgraph_function_versioning (node, redirect_callers, NULL, NULL,
4547 NULL, NULL, "isra");
4548 current_function_decl = new_node->decl;
4549 push_cfun (DECL_STRUCT_FUNCTION (new_node->decl));
4551 ipa_modify_formal_parameters (current_function_decl, adjustments, "ISRA");
4552 cfg_changed = ipa_sra_modify_function_body (adjustments);
4553 sra_ipa_reset_debug_stmts (adjustments);
4554 convert_callers (new_node, node->decl, adjustments);
4555 cgraph_make_node_local (new_node);
4559 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4560 attributes, return true otherwise. NODE is the cgraph node of the current
4564 ipa_sra_preliminary_function_checks (struct cgraph_node *node)
4566 if (!cgraph_node_can_be_local_p (node))
4569 fprintf (dump_file, "Function not local to this compilation unit.\n");
4573 if (!node->local.can_change_signature)
4576 fprintf (dump_file, "Function can not change signature.\n");
4580 if (!tree_versionable_function_p (node->decl))
4583 fprintf (dump_file, "Function is not versionable.\n");
4587 if (DECL_VIRTUAL_P (current_function_decl))
4590 fprintf (dump_file, "Function is a virtual method.\n");
4594 if ((DECL_COMDAT (node->decl) || DECL_EXTERNAL (node->decl))
4595 && node->global.size >= MAX_INLINE_INSNS_AUTO)
4598 fprintf (dump_file, "Function too big to be made truly local.\n");
4606 "Function has no callers in this compilation unit.\n");
4613 fprintf (dump_file, "Function uses stdarg. \n");
4617 if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl)))
4623 /* Perform early interprocedural SRA. */
4626 ipa_early_sra (void)
4628 struct cgraph_node *node = cgraph_node (current_function_decl);
4629 ipa_parm_adjustment_vec adjustments;
4632 if (!ipa_sra_preliminary_function_checks (node))
4636 sra_mode = SRA_MODE_EARLY_IPA;
4638 if (!find_param_candidates ())
4641 fprintf (dump_file, "Function has no IPA-SRA candidates.\n");
4645 if (!all_callers_have_enough_arguments_p (node))
4648 fprintf (dump_file, "There are callers with insufficient number of "
4653 bb_dereferences = XCNEWVEC (HOST_WIDE_INT,
4655 * last_basic_block_for_function (cfun));
4656 final_bbs = BITMAP_ALLOC (NULL);
4659 if (encountered_apply_args)
4662 fprintf (dump_file, "Function calls __builtin_apply_args().\n");
4666 if (encountered_unchangable_recursive_call)
4669 fprintf (dump_file, "Function calls itself with insufficient "
4670 "number of arguments.\n");
4674 adjustments = analyze_all_param_acesses ();
4678 ipa_dump_param_adjustments (dump_file, adjustments, current_function_decl);
4680 if (modify_function (node, adjustments))
4681 ret = TODO_update_ssa | TODO_cleanup_cfg;
4683 ret = TODO_update_ssa;
4684 VEC_free (ipa_parm_adjustment_t, heap, adjustments);
4686 statistics_counter_event (cfun, "Unused parameters deleted",
4687 sra_stats.deleted_unused_parameters);
4688 statistics_counter_event (cfun, "Scalar parameters converted to by-value",
4689 sra_stats.scalar_by_ref_to_by_val);
4690 statistics_counter_event (cfun, "Aggregate parameters broken up",
4691 sra_stats.aggregate_params_reduced);
4692 statistics_counter_event (cfun, "Aggregate parameter components created",
4693 sra_stats.param_reductions_created);
4696 BITMAP_FREE (final_bbs);
4697 free (bb_dereferences);
4699 sra_deinitialize ();
4703 /* Return if early ipa sra shall be performed. */
4705 ipa_early_sra_gate (void)
4707 return flag_ipa_sra && dbg_cnt (eipa_sra);
4710 struct gimple_opt_pass pass_early_ipa_sra =
4714 "eipa_sra", /* name */
4715 ipa_early_sra_gate, /* gate */
4716 ipa_early_sra, /* execute */
4719 0, /* static_pass_number */
4720 TV_IPA_SRA, /* tv_id */
4721 0, /* properties_required */
4722 0, /* properties_provided */
4723 0, /* properties_destroyed */
4724 0, /* todo_flags_start */
4725 TODO_dump_func | TODO_dump_cgraph /* todo_flags_finish */