1 /* Scalar Replacement of Aggregates (SRA) converts some structure
2 references into scalar references, exposing them to the scalar
4 Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
5 Contributed by Martin Jambor <mjambor@suse.cz>
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* This file implements Scalar Reduction of Aggregates (SRA). SRA is run
24 twice, once in the early stages of compilation (early SRA) and once in the
25 late stages (late SRA). The aim of both is to turn references to scalar
26 parts of aggregates into uses of independent scalar variables.
28 The two passes are nearly identical, the only difference is that early SRA
29 does not scalarize unions which are used as the result in a GIMPLE_RETURN
30 statement because together with inlining this can lead to weird type
33 Both passes operate in four stages:
35 1. The declarations that have properties which make them candidates for
36 scalarization are identified in function find_var_candidates(). The
37 candidates are stored in candidate_bitmap.
39 2. The function body is scanned. In the process, declarations which are
40 used in a manner that prevent their scalarization are removed from the
41 candidate bitmap. More importantly, for every access into an aggregate,
42 an access structure (struct access) is created by create_access() and
43 stored in a vector associated with the aggregate. Among other
44 information, the aggregate declaration, the offset and size of the access
45 and its type are stored in the structure.
47 On a related note, assign_link structures are created for every assign
48 statement between candidate aggregates and attached to the related
51 3. The vectors of accesses are analyzed. They are first sorted according to
52 their offset and size and then scanned for partially overlapping accesses
53 (i.e. those which overlap but one is not entirely within another). Such
54 an access disqualifies the whole aggregate from being scalarized.
56 If there is no such inhibiting overlap, a representative access structure
57 is chosen for every unique combination of offset and size. Afterwards,
58 the pass builds a set of trees from these structures, in which children
59 of an access are within their parent (in terms of offset and size).
61 Then accesses are propagated whenever possible (i.e. in cases when it
62 does not create a partially overlapping access) across assign_links from
63 the right hand side to the left hand side.
65 Then the set of trees for each declaration is traversed again and those
66 accesses which should be replaced by a scalar are identified.
68 4. The function is traversed again, and for every reference into an
69 aggregate that has some component which is about to be scalarized,
70 statements are amended and new statements are created as necessary.
71 Finally, if a parameter got scalarized, the scalar replacements are
72 initialized with values from respective parameter aggregates. */
76 #include "coretypes.h"
77 #include "alloc-pool.h"
82 #include "tree-flow.h"
84 #include "tree-pretty-print.h"
85 #include "statistics.h"
86 #include "tree-dump.h"
92 #include "tree-inline.h"
93 #include "gimple-pretty-print.h"
94 #include "ipa-inline.h"
96 /* Enumeration of all aggregate reductions we can do. */
97 enum sra_mode { SRA_MODE_EARLY_IPA, /* early call regularization */
98 SRA_MODE_EARLY_INTRA, /* early intraprocedural SRA */
99 SRA_MODE_INTRA }; /* late intraprocedural SRA */
101 /* Global variable describing which aggregate reduction we are performing at
103 static enum sra_mode sra_mode;
107 /* ACCESS represents each access to an aggregate variable (as a whole or a
108 part). It can also represent a group of accesses that refer to exactly the
109 same fragment of an aggregate (i.e. those that have exactly the same offset
110 and size). Such representatives for a single aggregate, once determined,
111 are linked in a linked list and have the group fields set.
113 Moreover, when doing intraprocedural SRA, a tree is built from those
114 representatives (by the means of first_child and next_sibling pointers), in
115 which all items in a subtree are "within" the root, i.e. their offset is
116 greater or equal to offset of the root and offset+size is smaller or equal
117 to offset+size of the root. Children of an access are sorted by offset.
119 Note that accesses to parts of vector and complex number types always
120 represented by an access to the whole complex number or a vector. It is a
121 duty of the modifying functions to replace them appropriately. */
125 /* Values returned by `get_ref_base_and_extent' for each component reference
126 If EXPR isn't a component reference just set `BASE = EXPR', `OFFSET = 0',
127 `SIZE = TREE_SIZE (TREE_TYPE (expr))'. */
128 HOST_WIDE_INT offset;
132 /* Expression. It is context dependent so do not use it to create new
133 expressions to access the original aggregate. See PR 42154 for a
139 /* The statement this access belongs to. */
142 /* Next group representative for this aggregate. */
143 struct access *next_grp;
145 /* Pointer to the group representative. Pointer to itself if the struct is
146 the representative. */
147 struct access *group_representative;
149 /* If this access has any children (in terms of the definition above), this
150 points to the first one. */
151 struct access *first_child;
153 /* In intraprocedural SRA, pointer to the next sibling in the access tree as
154 described above. In IPA-SRA this is a pointer to the next access
155 belonging to the same group (having the same representative). */
156 struct access *next_sibling;
158 /* Pointers to the first and last element in the linked list of assign
160 struct assign_link *first_link, *last_link;
162 /* Pointer to the next access in the work queue. */
163 struct access *next_queued;
165 /* Replacement variable for this access "region." Never to be accessed
166 directly, always only by the means of get_access_replacement() and only
167 when grp_to_be_replaced flag is set. */
168 tree replacement_decl;
170 /* Is this particular access write access? */
173 /* Is this access an access to a non-addressable field? */
174 unsigned non_addressable : 1;
176 /* Is this access currently in the work queue? */
177 unsigned grp_queued : 1;
179 /* Does this group contain a write access? This flag is propagated down the
181 unsigned grp_write : 1;
183 /* Does this group contain a read access? This flag is propagated down the
185 unsigned grp_read : 1;
187 /* Does this group contain a read access that comes from an assignment
188 statement? This flag is propagated down the access tree. */
189 unsigned grp_assignment_read : 1;
191 /* Does this group contain a write access that comes from an assignment
192 statement? This flag is propagated down the access tree. */
193 unsigned grp_assignment_write : 1;
195 /* Does this group contain a read access through a scalar type? This flag is
196 not propagated in the access tree in any direction. */
197 unsigned grp_scalar_read : 1;
199 /* Does this group contain a write access through a scalar type? This flag
200 is not propagated in the access tree in any direction. */
201 unsigned grp_scalar_write : 1;
203 /* Is this access an artificial one created to scalarize some record
205 unsigned grp_total_scalarization : 1;
207 /* Other passes of the analysis use this bit to make function
208 analyze_access_subtree create scalar replacements for this group if
210 unsigned grp_hint : 1;
212 /* Is the subtree rooted in this access fully covered by scalar
214 unsigned grp_covered : 1;
216 /* If set to true, this access and all below it in an access tree must not be
218 unsigned grp_unscalarizable_region : 1;
220 /* Whether data have been written to parts of the aggregate covered by this
221 access which is not to be scalarized. This flag is propagated up in the
223 unsigned grp_unscalarized_data : 1;
225 /* Does this access and/or group contain a write access through a
227 unsigned grp_partial_lhs : 1;
229 /* Set when a scalar replacement should be created for this variable. We do
230 the decision and creation at different places because create_tmp_var
231 cannot be called from within FOR_EACH_REFERENCED_VAR. */
232 unsigned grp_to_be_replaced : 1;
234 /* Should TREE_NO_WARNING of a replacement be set? */
235 unsigned grp_no_warning : 1;
237 /* Is it possible that the group refers to data which might be (directly or
238 otherwise) modified? */
239 unsigned grp_maybe_modified : 1;
241 /* Set when this is a representative of a pointer to scalar (i.e. by
242 reference) parameter which we consider for turning into a plain scalar
243 (i.e. a by value parameter). */
244 unsigned grp_scalar_ptr : 1;
246 /* Set when we discover that this pointer is not safe to dereference in the
248 unsigned grp_not_necessarilly_dereferenced : 1;
251 typedef struct access *access_p;
253 DEF_VEC_P (access_p);
254 DEF_VEC_ALLOC_P (access_p, heap);
256 /* Alloc pool for allocating access structures. */
257 static alloc_pool access_pool;
259 /* A structure linking lhs and rhs accesses from an aggregate assignment. They
260 are used to propagate subaccesses from rhs to lhs as long as they don't
261 conflict with what is already there. */
264 struct access *lacc, *racc;
265 struct assign_link *next;
268 /* Alloc pool for allocating assign link structures. */
269 static alloc_pool link_pool;
271 /* Base (tree) -> Vector (VEC(access_p,heap) *) map. */
272 static struct pointer_map_t *base_access_vec;
274 /* Bitmap of candidates. */
275 static bitmap candidate_bitmap;
277 /* Bitmap of candidates which we should try to entirely scalarize away and
278 those which cannot be (because they are and need be used as a whole). */
279 static bitmap should_scalarize_away_bitmap, cannot_scalarize_away_bitmap;
281 /* Obstack for creation of fancy names. */
282 static struct obstack name_obstack;
284 /* Head of a linked list of accesses that need to have its subaccesses
285 propagated to their assignment counterparts. */
286 static struct access *work_queue_head;
288 /* Number of parameters of the analyzed function when doing early ipa SRA. */
289 static int func_param_count;
291 /* scan_function sets the following to true if it encounters a call to
292 __builtin_apply_args. */
293 static bool encountered_apply_args;
295 /* Set by scan_function when it finds a recursive call. */
296 static bool encountered_recursive_call;
298 /* Set by scan_function when it finds a recursive call with less actual
299 arguments than formal parameters.. */
300 static bool encountered_unchangable_recursive_call;
302 /* This is a table in which for each basic block and parameter there is a
303 distance (offset + size) in that parameter which is dereferenced and
304 accessed in that BB. */
305 static HOST_WIDE_INT *bb_dereferences;
306 /* Bitmap of BBs that can cause the function to "stop" progressing by
307 returning, throwing externally, looping infinitely or calling a function
308 which might abort etc.. */
309 static bitmap final_bbs;
311 /* Representative of no accesses at all. */
312 static struct access no_accesses_representant;
314 /* Predicate to test the special value. */
317 no_accesses_p (struct access *access)
319 return access == &no_accesses_representant;
322 /* Dump contents of ACCESS to file F in a human friendly way. If GRP is true,
323 representative fields are dumped, otherwise those which only describe the
324 individual access are. */
328 /* Number of processed aggregates is readily available in
329 analyze_all_variable_accesses and so is not stored here. */
331 /* Number of created scalar replacements. */
334 /* Number of times sra_modify_expr or sra_modify_assign themselves changed an
338 /* Number of statements created by generate_subtree_copies. */
341 /* Number of statements created by load_assign_lhs_subreplacements. */
344 /* Number of times sra_modify_assign has deleted a statement. */
347 /* Number of times sra_modify_assign has to deal with subaccesses of LHS and
348 RHS reparately due to type conversions or nonexistent matching
350 int separate_lhs_rhs_handling;
352 /* Number of parameters that were removed because they were unused. */
353 int deleted_unused_parameters;
355 /* Number of scalars passed as parameters by reference that have been
356 converted to be passed by value. */
357 int scalar_by_ref_to_by_val;
359 /* Number of aggregate parameters that were replaced by one or more of their
361 int aggregate_params_reduced;
363 /* Numbber of components created when splitting aggregate parameters. */
364 int param_reductions_created;
368 dump_access (FILE *f, struct access *access, bool grp)
370 fprintf (f, "access { ");
371 fprintf (f, "base = (%d)'", DECL_UID (access->base));
372 print_generic_expr (f, access->base, 0);
373 fprintf (f, "', offset = " HOST_WIDE_INT_PRINT_DEC, access->offset);
374 fprintf (f, ", size = " HOST_WIDE_INT_PRINT_DEC, access->size);
375 fprintf (f, ", expr = ");
376 print_generic_expr (f, access->expr, 0);
377 fprintf (f, ", type = ");
378 print_generic_expr (f, access->type, 0);
380 fprintf (f, ", grp_read = %d, grp_write = %d, grp_assignment_read = %d, "
381 "grp_assignment_write = %d, grp_scalar_read = %d, "
382 "grp_scalar_write = %d, grp_total_scalarization = %d, "
383 "grp_hint = %d, grp_covered = %d, "
384 "grp_unscalarizable_region = %d, grp_unscalarized_data = %d, "
385 "grp_partial_lhs = %d, grp_to_be_replaced = %d, "
386 "grp_maybe_modified = %d, "
387 "grp_not_necessarilly_dereferenced = %d\n",
388 access->grp_read, access->grp_write, access->grp_assignment_read,
389 access->grp_assignment_write, access->grp_scalar_read,
390 access->grp_scalar_write, access->grp_total_scalarization,
391 access->grp_hint, access->grp_covered,
392 access->grp_unscalarizable_region, access->grp_unscalarized_data,
393 access->grp_partial_lhs, access->grp_to_be_replaced,
394 access->grp_maybe_modified,
395 access->grp_not_necessarilly_dereferenced);
397 fprintf (f, ", write = %d, grp_total_scalarization = %d, "
398 "grp_partial_lhs = %d\n",
399 access->write, access->grp_total_scalarization,
400 access->grp_partial_lhs);
403 /* Dump a subtree rooted in ACCESS to file F, indent by LEVEL. */
406 dump_access_tree_1 (FILE *f, struct access *access, int level)
412 for (i = 0; i < level; i++)
413 fputs ("* ", dump_file);
415 dump_access (f, access, true);
417 if (access->first_child)
418 dump_access_tree_1 (f, access->first_child, level + 1);
420 access = access->next_sibling;
425 /* Dump all access trees for a variable, given the pointer to the first root in
429 dump_access_tree (FILE *f, struct access *access)
431 for (; access; access = access->next_grp)
432 dump_access_tree_1 (f, access, 0);
435 /* Return true iff ACC is non-NULL and has subaccesses. */
438 access_has_children_p (struct access *acc)
440 return acc && acc->first_child;
443 /* Return a vector of pointers to accesses for the variable given in BASE or
444 NULL if there is none. */
446 static VEC (access_p, heap) *
447 get_base_access_vector (tree base)
451 slot = pointer_map_contains (base_access_vec, base);
455 return *(VEC (access_p, heap) **) slot;
458 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
459 in ACCESS. Return NULL if it cannot be found. */
461 static struct access *
462 find_access_in_subtree (struct access *access, HOST_WIDE_INT offset,
465 while (access && (access->offset != offset || access->size != size))
467 struct access *child = access->first_child;
469 while (child && (child->offset + child->size <= offset))
470 child = child->next_sibling;
477 /* Return the first group representative for DECL or NULL if none exists. */
479 static struct access *
480 get_first_repr_for_decl (tree base)
482 VEC (access_p, heap) *access_vec;
484 access_vec = get_base_access_vector (base);
488 return VEC_index (access_p, access_vec, 0);
491 /* Find an access representative for the variable BASE and given OFFSET and
492 SIZE. Requires that access trees have already been built. Return NULL if
493 it cannot be found. */
495 static struct access *
496 get_var_base_offset_size_access (tree base, HOST_WIDE_INT offset,
499 struct access *access;
501 access = get_first_repr_for_decl (base);
502 while (access && (access->offset + access->size <= offset))
503 access = access->next_grp;
507 return find_access_in_subtree (access, offset, size);
510 /* Add LINK to the linked list of assign links of RACC. */
512 add_link_to_rhs (struct access *racc, struct assign_link *link)
514 gcc_assert (link->racc == racc);
516 if (!racc->first_link)
518 gcc_assert (!racc->last_link);
519 racc->first_link = link;
522 racc->last_link->next = link;
524 racc->last_link = link;
528 /* Move all link structures in their linked list in OLD_RACC to the linked list
531 relink_to_new_repr (struct access *new_racc, struct access *old_racc)
533 if (!old_racc->first_link)
535 gcc_assert (!old_racc->last_link);
539 if (new_racc->first_link)
541 gcc_assert (!new_racc->last_link->next);
542 gcc_assert (!old_racc->last_link || !old_racc->last_link->next);
544 new_racc->last_link->next = old_racc->first_link;
545 new_racc->last_link = old_racc->last_link;
549 gcc_assert (!new_racc->last_link);
551 new_racc->first_link = old_racc->first_link;
552 new_racc->last_link = old_racc->last_link;
554 old_racc->first_link = old_racc->last_link = NULL;
557 /* Add ACCESS to the work queue (which is actually a stack). */
560 add_access_to_work_queue (struct access *access)
562 if (!access->grp_queued)
564 gcc_assert (!access->next_queued);
565 access->next_queued = work_queue_head;
566 access->grp_queued = 1;
567 work_queue_head = access;
571 /* Pop an access from the work queue, and return it, assuming there is one. */
573 static struct access *
574 pop_access_from_work_queue (void)
576 struct access *access = work_queue_head;
578 work_queue_head = access->next_queued;
579 access->next_queued = NULL;
580 access->grp_queued = 0;
585 /* Allocate necessary structures. */
588 sra_initialize (void)
590 candidate_bitmap = BITMAP_ALLOC (NULL);
591 should_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
592 cannot_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
593 gcc_obstack_init (&name_obstack);
594 access_pool = create_alloc_pool ("SRA accesses", sizeof (struct access), 16);
595 link_pool = create_alloc_pool ("SRA links", sizeof (struct assign_link), 16);
596 base_access_vec = pointer_map_create ();
597 memset (&sra_stats, 0, sizeof (sra_stats));
598 encountered_apply_args = false;
599 encountered_recursive_call = false;
600 encountered_unchangable_recursive_call = false;
603 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
606 delete_base_accesses (const void *key ATTRIBUTE_UNUSED, void **value,
607 void *data ATTRIBUTE_UNUSED)
609 VEC (access_p, heap) *access_vec;
610 access_vec = (VEC (access_p, heap) *) *value;
611 VEC_free (access_p, heap, access_vec);
616 /* Deallocate all general structures. */
619 sra_deinitialize (void)
621 BITMAP_FREE (candidate_bitmap);
622 BITMAP_FREE (should_scalarize_away_bitmap);
623 BITMAP_FREE (cannot_scalarize_away_bitmap);
624 free_alloc_pool (access_pool);
625 free_alloc_pool (link_pool);
626 obstack_free (&name_obstack, NULL);
628 pointer_map_traverse (base_access_vec, delete_base_accesses, NULL);
629 pointer_map_destroy (base_access_vec);
632 /* Remove DECL from candidates for SRA and write REASON to the dump file if
635 disqualify_candidate (tree decl, const char *reason)
637 bitmap_clear_bit (candidate_bitmap, DECL_UID (decl));
639 if (dump_file && (dump_flags & TDF_DETAILS))
641 fprintf (dump_file, "! Disqualifying ");
642 print_generic_expr (dump_file, decl, 0);
643 fprintf (dump_file, " - %s\n", reason);
647 /* Return true iff the type contains a field or an element which does not allow
651 type_internals_preclude_sra_p (tree type, const char **msg)
656 switch (TREE_CODE (type))
660 case QUAL_UNION_TYPE:
661 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
662 if (TREE_CODE (fld) == FIELD_DECL)
664 tree ft = TREE_TYPE (fld);
666 if (TREE_THIS_VOLATILE (fld))
668 *msg = "volatile structure field";
671 if (!DECL_FIELD_OFFSET (fld))
673 *msg = "no structure field offset";
676 if (!DECL_SIZE (fld))
678 *msg = "zero structure field size";
681 if (!host_integerp (DECL_FIELD_OFFSET (fld), 1))
683 *msg = "structure field offset not fixed";
686 if (!host_integerp (DECL_SIZE (fld), 1))
688 *msg = "structure field size not fixed";
691 if (AGGREGATE_TYPE_P (ft)
692 && int_bit_position (fld) % BITS_PER_UNIT != 0)
694 *msg = "structure field is bit field";
698 if (AGGREGATE_TYPE_P (ft) && type_internals_preclude_sra_p (ft, msg))
705 et = TREE_TYPE (type);
707 if (TYPE_VOLATILE (et))
709 *msg = "element type is volatile";
713 if (AGGREGATE_TYPE_P (et) && type_internals_preclude_sra_p (et, msg))
723 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
724 base variable if it is. Return T if it is not an SSA_NAME. */
727 get_ssa_base_param (tree t)
729 if (TREE_CODE (t) == SSA_NAME)
731 if (SSA_NAME_IS_DEFAULT_DEF (t))
732 return SSA_NAME_VAR (t);
739 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
740 belongs to, unless the BB has already been marked as a potentially
744 mark_parm_dereference (tree base, HOST_WIDE_INT dist, gimple stmt)
746 basic_block bb = gimple_bb (stmt);
747 int idx, parm_index = 0;
750 if (bitmap_bit_p (final_bbs, bb->index))
753 for (parm = DECL_ARGUMENTS (current_function_decl);
754 parm && parm != base;
755 parm = DECL_CHAIN (parm))
758 gcc_assert (parm_index < func_param_count);
760 idx = bb->index * func_param_count + parm_index;
761 if (bb_dereferences[idx] < dist)
762 bb_dereferences[idx] = dist;
765 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
766 the three fields. Also add it to the vector of accesses corresponding to
767 the base. Finally, return the new access. */
769 static struct access *
770 create_access_1 (tree base, HOST_WIDE_INT offset, HOST_WIDE_INT size)
772 VEC (access_p, heap) *vec;
773 struct access *access;
776 access = (struct access *) pool_alloc (access_pool);
777 memset (access, 0, sizeof (struct access));
779 access->offset = offset;
782 slot = pointer_map_contains (base_access_vec, base);
784 vec = (VEC (access_p, heap) *) *slot;
786 vec = VEC_alloc (access_p, heap, 32);
788 VEC_safe_push (access_p, heap, vec, access);
790 *((struct VEC (access_p,heap) **)
791 pointer_map_insert (base_access_vec, base)) = vec;
796 /* Create and insert access for EXPR. Return created access, or NULL if it is
799 static struct access *
800 create_access (tree expr, gimple stmt, bool write)
802 struct access *access;
803 HOST_WIDE_INT offset, size, max_size;
805 bool ptr, unscalarizable_region = false;
807 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
809 if (sra_mode == SRA_MODE_EARLY_IPA
810 && TREE_CODE (base) == MEM_REF)
812 base = get_ssa_base_param (TREE_OPERAND (base, 0));
820 if (!DECL_P (base) || !bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
823 if (sra_mode == SRA_MODE_EARLY_IPA)
825 if (size < 0 || size != max_size)
827 disqualify_candidate (base, "Encountered a variable sized access.");
830 if (TREE_CODE (expr) == COMPONENT_REF
831 && DECL_BIT_FIELD (TREE_OPERAND (expr, 1)))
833 disqualify_candidate (base, "Encountered a bit-field access.");
836 gcc_checking_assert ((offset % BITS_PER_UNIT) == 0);
839 mark_parm_dereference (base, offset + size, stmt);
843 if (size != max_size)
846 unscalarizable_region = true;
850 disqualify_candidate (base, "Encountered an unconstrained access.");
855 access = create_access_1 (base, offset, size);
857 access->type = TREE_TYPE (expr);
858 access->write = write;
859 access->grp_unscalarizable_region = unscalarizable_region;
862 if (TREE_CODE (expr) == COMPONENT_REF
863 && DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1)))
864 access->non_addressable = 1;
870 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
871 register types or (recursively) records with only these two kinds of fields.
872 It also returns false if any of these records contains a bit-field. */
875 type_consists_of_records_p (tree type)
879 if (TREE_CODE (type) != RECORD_TYPE)
882 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
883 if (TREE_CODE (fld) == FIELD_DECL)
885 tree ft = TREE_TYPE (fld);
887 if (DECL_BIT_FIELD (fld))
890 if (!is_gimple_reg_type (ft)
891 && !type_consists_of_records_p (ft))
898 /* Create total_scalarization accesses for all scalar type fields in DECL that
899 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
900 must be the top-most VAR_DECL representing the variable, OFFSET must be the
901 offset of DECL within BASE. REF must be the memory reference expression for
905 completely_scalarize_record (tree base, tree decl, HOST_WIDE_INT offset,
908 tree fld, decl_type = TREE_TYPE (decl);
910 for (fld = TYPE_FIELDS (decl_type); fld; fld = DECL_CHAIN (fld))
911 if (TREE_CODE (fld) == FIELD_DECL)
913 HOST_WIDE_INT pos = offset + int_bit_position (fld);
914 tree ft = TREE_TYPE (fld);
915 tree nref = build3 (COMPONENT_REF, TREE_TYPE (fld), ref, fld,
918 if (is_gimple_reg_type (ft))
920 struct access *access;
923 size = tree_low_cst (DECL_SIZE (fld), 1);
924 access = create_access_1 (base, pos, size);
927 access->grp_total_scalarization = 1;
928 /* Accesses for intraprocedural SRA can have their stmt NULL. */
931 completely_scalarize_record (base, fld, pos, nref);
935 /* Create total_scalarization accesses for all scalar type fields in VAR and
936 for VAR a a whole. VAR must be of a RECORD_TYPE conforming to
937 type_consists_of_records_p. */
940 completely_scalarize_var (tree var)
942 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (var), 1);
943 struct access *access;
945 access = create_access_1 (var, 0, size);
947 access->type = TREE_TYPE (var);
948 access->grp_total_scalarization = 1;
950 completely_scalarize_record (var, var, 0, var);
953 /* Search the given tree for a declaration by skipping handled components and
954 exclude it from the candidates. */
957 disqualify_base_of_expr (tree t, const char *reason)
959 t = get_base_address (t);
960 if (sra_mode == SRA_MODE_EARLY_IPA
961 && TREE_CODE (t) == MEM_REF)
962 t = get_ssa_base_param (TREE_OPERAND (t, 0));
965 disqualify_candidate (t, reason);
968 /* Scan expression EXPR and create access structures for all accesses to
969 candidates for scalarization. Return the created access or NULL if none is
972 static struct access *
973 build_access_from_expr_1 (tree expr, gimple stmt, bool write)
975 struct access *ret = NULL;
978 if (TREE_CODE (expr) == BIT_FIELD_REF
979 || TREE_CODE (expr) == IMAGPART_EXPR
980 || TREE_CODE (expr) == REALPART_EXPR)
982 expr = TREE_OPERAND (expr, 0);
988 /* We need to dive through V_C_Es in order to get the size of its parameter
989 and not the result type. Ada produces such statements. We are also
990 capable of handling the topmost V_C_E but not any of those buried in other
991 handled components. */
992 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
993 expr = TREE_OPERAND (expr, 0);
995 if (contains_view_convert_expr_p (expr))
997 disqualify_base_of_expr (expr, "V_C_E under a different handled "
1002 switch (TREE_CODE (expr))
1005 if (TREE_CODE (TREE_OPERAND (expr, 0)) != ADDR_EXPR
1006 && sra_mode != SRA_MODE_EARLY_IPA)
1014 case ARRAY_RANGE_REF:
1015 ret = create_access (expr, stmt, write);
1022 if (write && partial_ref && ret)
1023 ret->grp_partial_lhs = 1;
1028 /* Scan expression EXPR and create access structures for all accesses to
1029 candidates for scalarization. Return true if any access has been inserted.
1030 STMT must be the statement from which the expression is taken, WRITE must be
1031 true if the expression is a store and false otherwise. */
1034 build_access_from_expr (tree expr, gimple stmt, bool write)
1036 struct access *access;
1038 access = build_access_from_expr_1 (expr, stmt, write);
1041 /* This means the aggregate is accesses as a whole in a way other than an
1042 assign statement and thus cannot be removed even if we had a scalar
1043 replacement for everything. */
1044 if (cannot_scalarize_away_bitmap)
1045 bitmap_set_bit (cannot_scalarize_away_bitmap, DECL_UID (access->base));
1051 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
1052 modes in which it matters, return true iff they have been disqualified. RHS
1053 may be NULL, in that case ignore it. If we scalarize an aggregate in
1054 intra-SRA we may need to add statements after each statement. This is not
1055 possible if a statement unconditionally has to end the basic block. */
1057 disqualify_ops_if_throwing_stmt (gimple stmt, tree lhs, tree rhs)
1059 if ((sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1060 && (stmt_can_throw_internal (stmt) || stmt_ends_bb_p (stmt)))
1062 disqualify_base_of_expr (lhs, "LHS of a throwing stmt.");
1064 disqualify_base_of_expr (rhs, "RHS of a throwing stmt.");
1070 /* Return true iff type of EXP is not sufficiently aligned. */
1073 tree_non_mode_aligned_mem_p (tree exp)
1075 enum machine_mode mode = TYPE_MODE (TREE_TYPE (exp));
1078 if (TREE_CODE (exp) == VIEW_CONVERT_EXPR)
1079 exp = TREE_OPERAND (exp, 0);
1081 if (TREE_CODE (exp) == SSA_NAME
1082 || TREE_CODE (exp) == MEM_REF
1084 || is_gimple_min_invariant (exp)
1085 || !STRICT_ALIGNMENT)
1088 align = get_object_alignment (exp);
1089 if (GET_MODE_ALIGNMENT (mode) > align)
1095 /* Scan expressions occuring in STMT, create access structures for all accesses
1096 to candidates for scalarization and remove those candidates which occur in
1097 statements or expressions that prevent them from being split apart. Return
1098 true if any access has been inserted. */
1101 build_accesses_from_assign (gimple stmt)
1104 struct access *lacc, *racc;
1106 if (!gimple_assign_single_p (stmt)
1107 /* Scope clobbers don't influence scalarization. */
1108 || gimple_clobber_p (stmt))
1111 lhs = gimple_assign_lhs (stmt);
1112 rhs = gimple_assign_rhs1 (stmt);
1114 if (disqualify_ops_if_throwing_stmt (stmt, lhs, rhs))
1117 racc = build_access_from_expr_1 (rhs, stmt, false);
1118 lacc = build_access_from_expr_1 (lhs, stmt, true);
1122 lacc->grp_assignment_write = 1;
1123 lacc->grp_unscalarizable_region |= tree_non_mode_aligned_mem_p (rhs);
1128 racc->grp_assignment_read = 1;
1129 if (should_scalarize_away_bitmap && !gimple_has_volatile_ops (stmt)
1130 && !is_gimple_reg_type (racc->type))
1131 bitmap_set_bit (should_scalarize_away_bitmap, DECL_UID (racc->base));
1132 racc->grp_unscalarizable_region |= tree_non_mode_aligned_mem_p (lhs);
1136 && (sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1137 && !lacc->grp_unscalarizable_region
1138 && !racc->grp_unscalarizable_region
1139 && AGGREGATE_TYPE_P (TREE_TYPE (lhs))
1140 /* FIXME: Turn the following line into an assert after PR 40058 is
1142 && lacc->size == racc->size
1143 && useless_type_conversion_p (lacc->type, racc->type))
1145 struct assign_link *link;
1147 link = (struct assign_link *) pool_alloc (link_pool);
1148 memset (link, 0, sizeof (struct assign_link));
1153 add_link_to_rhs (racc, link);
1156 return lacc || racc;
1159 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1160 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1163 asm_visit_addr (gimple stmt ATTRIBUTE_UNUSED, tree op,
1164 void *data ATTRIBUTE_UNUSED)
1166 op = get_base_address (op);
1169 disqualify_candidate (op, "Non-scalarizable GIMPLE_ASM operand.");
1174 /* Return true iff callsite CALL has at least as many actual arguments as there
1175 are formal parameters of the function currently processed by IPA-SRA. */
1178 callsite_has_enough_arguments_p (gimple call)
1180 return gimple_call_num_args (call) >= (unsigned) func_param_count;
1183 /* Scan function and look for interesting expressions and create access
1184 structures for them. Return true iff any access is created. */
1187 scan_function (void)
1194 gimple_stmt_iterator gsi;
1195 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1197 gimple stmt = gsi_stmt (gsi);
1201 if (final_bbs && stmt_can_throw_external (stmt))
1202 bitmap_set_bit (final_bbs, bb->index);
1203 switch (gimple_code (stmt))
1206 t = gimple_return_retval (stmt);
1208 ret |= build_access_from_expr (t, stmt, false);
1210 bitmap_set_bit (final_bbs, bb->index);
1214 ret |= build_accesses_from_assign (stmt);
1218 for (i = 0; i < gimple_call_num_args (stmt); i++)
1219 ret |= build_access_from_expr (gimple_call_arg (stmt, i),
1222 if (sra_mode == SRA_MODE_EARLY_IPA)
1224 tree dest = gimple_call_fndecl (stmt);
1225 int flags = gimple_call_flags (stmt);
1229 if (DECL_BUILT_IN_CLASS (dest) == BUILT_IN_NORMAL
1230 && DECL_FUNCTION_CODE (dest) == BUILT_IN_APPLY_ARGS)
1231 encountered_apply_args = true;
1232 if (cgraph_get_node (dest)
1233 == cgraph_get_node (current_function_decl))
1235 encountered_recursive_call = true;
1236 if (!callsite_has_enough_arguments_p (stmt))
1237 encountered_unchangable_recursive_call = true;
1242 && (flags & (ECF_CONST | ECF_PURE)) == 0)
1243 bitmap_set_bit (final_bbs, bb->index);
1246 t = gimple_call_lhs (stmt);
1247 if (t && !disqualify_ops_if_throwing_stmt (stmt, t, NULL))
1248 ret |= build_access_from_expr (t, stmt, true);
1252 walk_stmt_load_store_addr_ops (stmt, NULL, NULL, NULL,
1255 bitmap_set_bit (final_bbs, bb->index);
1257 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
1259 t = TREE_VALUE (gimple_asm_input_op (stmt, i));
1260 ret |= build_access_from_expr (t, stmt, false);
1262 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
1264 t = TREE_VALUE (gimple_asm_output_op (stmt, i));
1265 ret |= build_access_from_expr (t, stmt, true);
1278 /* Helper of QSORT function. There are pointers to accesses in the array. An
1279 access is considered smaller than another if it has smaller offset or if the
1280 offsets are the same but is size is bigger. */
1283 compare_access_positions (const void *a, const void *b)
1285 const access_p *fp1 = (const access_p *) a;
1286 const access_p *fp2 = (const access_p *) b;
1287 const access_p f1 = *fp1;
1288 const access_p f2 = *fp2;
1290 if (f1->offset != f2->offset)
1291 return f1->offset < f2->offset ? -1 : 1;
1293 if (f1->size == f2->size)
1295 if (f1->type == f2->type)
1297 /* Put any non-aggregate type before any aggregate type. */
1298 else if (!is_gimple_reg_type (f1->type)
1299 && is_gimple_reg_type (f2->type))
1301 else if (is_gimple_reg_type (f1->type)
1302 && !is_gimple_reg_type (f2->type))
1304 /* Put any complex or vector type before any other scalar type. */
1305 else if (TREE_CODE (f1->type) != COMPLEX_TYPE
1306 && TREE_CODE (f1->type) != VECTOR_TYPE
1307 && (TREE_CODE (f2->type) == COMPLEX_TYPE
1308 || TREE_CODE (f2->type) == VECTOR_TYPE))
1310 else if ((TREE_CODE (f1->type) == COMPLEX_TYPE
1311 || TREE_CODE (f1->type) == VECTOR_TYPE)
1312 && TREE_CODE (f2->type) != COMPLEX_TYPE
1313 && TREE_CODE (f2->type) != VECTOR_TYPE)
1315 /* Put the integral type with the bigger precision first. */
1316 else if (INTEGRAL_TYPE_P (f1->type)
1317 && INTEGRAL_TYPE_P (f2->type))
1318 return TYPE_PRECISION (f2->type) - TYPE_PRECISION (f1->type);
1319 /* Put any integral type with non-full precision last. */
1320 else if (INTEGRAL_TYPE_P (f1->type)
1321 && (TREE_INT_CST_LOW (TYPE_SIZE (f1->type))
1322 != TYPE_PRECISION (f1->type)))
1324 else if (INTEGRAL_TYPE_P (f2->type)
1325 && (TREE_INT_CST_LOW (TYPE_SIZE (f2->type))
1326 != TYPE_PRECISION (f2->type)))
1328 /* Stabilize the sort. */
1329 return TYPE_UID (f1->type) - TYPE_UID (f2->type);
1332 /* We want the bigger accesses first, thus the opposite operator in the next
1334 return f1->size > f2->size ? -1 : 1;
1338 /* Append a name of the declaration to the name obstack. A helper function for
1342 make_fancy_decl_name (tree decl)
1346 tree name = DECL_NAME (decl);
1348 obstack_grow (&name_obstack, IDENTIFIER_POINTER (name),
1349 IDENTIFIER_LENGTH (name));
1352 sprintf (buffer, "D%u", DECL_UID (decl));
1353 obstack_grow (&name_obstack, buffer, strlen (buffer));
1357 /* Helper for make_fancy_name. */
1360 make_fancy_name_1 (tree expr)
1367 make_fancy_decl_name (expr);
1371 switch (TREE_CODE (expr))
1374 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1375 obstack_1grow (&name_obstack, '$');
1376 make_fancy_decl_name (TREE_OPERAND (expr, 1));
1380 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1381 obstack_1grow (&name_obstack, '$');
1382 /* Arrays with only one element may not have a constant as their
1384 index = TREE_OPERAND (expr, 1);
1385 if (TREE_CODE (index) != INTEGER_CST)
1387 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC, TREE_INT_CST_LOW (index));
1388 obstack_grow (&name_obstack, buffer, strlen (buffer));
1392 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1396 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1397 if (!integer_zerop (TREE_OPERAND (expr, 1)))
1399 obstack_1grow (&name_obstack, '$');
1400 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC,
1401 TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)));
1402 obstack_grow (&name_obstack, buffer, strlen (buffer));
1409 gcc_unreachable (); /* we treat these as scalars. */
1416 /* Create a human readable name for replacement variable of ACCESS. */
1419 make_fancy_name (tree expr)
1421 make_fancy_name_1 (expr);
1422 obstack_1grow (&name_obstack, '\0');
1423 return XOBFINISH (&name_obstack, char *);
1426 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1427 EXP_TYPE at the given OFFSET. If BASE is something for which
1428 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1429 to insert new statements either before or below the current one as specified
1430 by INSERT_AFTER. This function is not capable of handling bitfields. */
1433 build_ref_for_offset (location_t loc, tree base, HOST_WIDE_INT offset,
1434 tree exp_type, gimple_stmt_iterator *gsi,
1437 tree prev_base = base;
1439 HOST_WIDE_INT base_offset;
1441 gcc_checking_assert (offset % BITS_PER_UNIT == 0);
1443 base = get_addr_base_and_unit_offset (base, &base_offset);
1445 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1446 offset such as array[var_index]. */
1452 gcc_checking_assert (gsi);
1453 tmp = create_tmp_reg (build_pointer_type (TREE_TYPE (prev_base)), NULL);
1454 add_referenced_var (tmp);
1455 tmp = make_ssa_name (tmp, NULL);
1456 addr = build_fold_addr_expr (unshare_expr (prev_base));
1457 STRIP_USELESS_TYPE_CONVERSION (addr);
1458 stmt = gimple_build_assign (tmp, addr);
1459 gimple_set_location (stmt, loc);
1460 SSA_NAME_DEF_STMT (tmp) = stmt;
1462 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
1464 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1467 off = build_int_cst (reference_alias_ptr_type (prev_base),
1468 offset / BITS_PER_UNIT);
1471 else if (TREE_CODE (base) == MEM_REF)
1473 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1474 base_offset + offset / BITS_PER_UNIT);
1475 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off);
1476 base = unshare_expr (TREE_OPERAND (base, 0));
1480 off = build_int_cst (reference_alias_ptr_type (base),
1481 base_offset + offset / BITS_PER_UNIT);
1482 base = build_fold_addr_expr (unshare_expr (base));
1485 return fold_build2_loc (loc, MEM_REF, exp_type, base, off);
1488 /* Construct a memory reference to a part of an aggregate BASE at the given
1489 OFFSET and of the same type as MODEL. In case this is a reference to a
1490 component, the function will replicate the last COMPONENT_REF of model's
1491 expr to access it. GSI and INSERT_AFTER have the same meaning as in
1492 build_ref_for_offset. */
1495 build_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1496 struct access *model, gimple_stmt_iterator *gsi,
1499 if (TREE_CODE (model->expr) == COMPONENT_REF)
1501 tree t, exp_type, fld = TREE_OPERAND (model->expr, 1);
1502 tree cr_offset = component_ref_field_offset (model->expr);
1504 gcc_assert (cr_offset && host_integerp (cr_offset, 1));
1505 offset -= TREE_INT_CST_LOW (cr_offset) * BITS_PER_UNIT;
1506 offset -= TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fld));
1507 exp_type = TREE_TYPE (TREE_OPERAND (model->expr, 0));
1508 t = build_ref_for_offset (loc, base, offset, exp_type, gsi, insert_after);
1509 return fold_build3_loc (loc, COMPONENT_REF, TREE_TYPE (fld), t, fld,
1510 TREE_OPERAND (model->expr, 2));
1513 return build_ref_for_offset (loc, base, offset, model->type,
1517 /* Construct a memory reference consisting of component_refs and array_refs to
1518 a part of an aggregate *RES (which is of type TYPE). The requested part
1519 should have type EXP_TYPE at be the given OFFSET. This function might not
1520 succeed, it returns true when it does and only then *RES points to something
1521 meaningful. This function should be used only to build expressions that we
1522 might need to present to user (e.g. in warnings). In all other situations,
1523 build_ref_for_model or build_ref_for_offset should be used instead. */
1526 build_user_friendly_ref_for_offset (tree *res, tree type, HOST_WIDE_INT offset,
1532 tree tr_size, index, minidx;
1533 HOST_WIDE_INT el_size;
1535 if (offset == 0 && exp_type
1536 && types_compatible_p (exp_type, type))
1539 switch (TREE_CODE (type))
1542 case QUAL_UNION_TYPE:
1544 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
1546 HOST_WIDE_INT pos, size;
1547 tree expr, *expr_ptr;
1549 if (TREE_CODE (fld) != FIELD_DECL)
1552 pos = int_bit_position (fld);
1553 gcc_assert (TREE_CODE (type) == RECORD_TYPE || pos == 0);
1554 tr_size = DECL_SIZE (fld);
1555 if (!tr_size || !host_integerp (tr_size, 1))
1557 size = tree_low_cst (tr_size, 1);
1563 else if (pos > offset || (pos + size) <= offset)
1566 expr = build3 (COMPONENT_REF, TREE_TYPE (fld), *res, fld,
1569 if (build_user_friendly_ref_for_offset (expr_ptr, TREE_TYPE (fld),
1570 offset - pos, exp_type))
1579 tr_size = TYPE_SIZE (TREE_TYPE (type));
1580 if (!tr_size || !host_integerp (tr_size, 1))
1582 el_size = tree_low_cst (tr_size, 1);
1584 minidx = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
1585 if (TREE_CODE (minidx) != INTEGER_CST || el_size == 0)
1587 index = build_int_cst (TYPE_DOMAIN (type), offset / el_size);
1588 if (!integer_zerop (minidx))
1589 index = int_const_binop (PLUS_EXPR, index, minidx);
1590 *res = build4 (ARRAY_REF, TREE_TYPE (type), *res, index,
1591 NULL_TREE, NULL_TREE);
1592 offset = offset % el_size;
1593 type = TREE_TYPE (type);
1608 /* Return true iff TYPE is stdarg va_list type. */
1611 is_va_list_type (tree type)
1613 return TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (va_list_type_node);
1616 /* Print message to dump file why a variable was rejected. */
1619 reject (tree var, const char *msg)
1621 if (dump_file && (dump_flags & TDF_DETAILS))
1623 fprintf (dump_file, "Rejected (%d): %s: ", DECL_UID (var), msg);
1624 print_generic_expr (dump_file, var, 0);
1625 fprintf (dump_file, "\n");
1629 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1630 those with type which is suitable for scalarization. */
1633 find_var_candidates (void)
1636 referenced_var_iterator rvi;
1640 FOR_EACH_REFERENCED_VAR (cfun, var, rvi)
1642 if (TREE_CODE (var) != VAR_DECL && TREE_CODE (var) != PARM_DECL)
1644 type = TREE_TYPE (var);
1646 if (!AGGREGATE_TYPE_P (type))
1648 reject (var, "not aggregate");
1651 if (needs_to_live_in_memory (var))
1653 reject (var, "needs to live in memory");
1656 if (TREE_THIS_VOLATILE (var))
1658 reject (var, "is volatile");
1661 if (!COMPLETE_TYPE_P (type))
1663 reject (var, "has incomplete type");
1666 if (!host_integerp (TYPE_SIZE (type), 1))
1668 reject (var, "type size not fixed");
1671 if (tree_low_cst (TYPE_SIZE (type), 1) == 0)
1673 reject (var, "type size is zero");
1676 if (type_internals_preclude_sra_p (type, &msg))
1681 if (/* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1682 we also want to schedule it rather late. Thus we ignore it in
1684 (sra_mode == SRA_MODE_EARLY_INTRA
1685 && is_va_list_type (type)))
1687 reject (var, "is va_list");
1691 bitmap_set_bit (candidate_bitmap, DECL_UID (var));
1693 if (dump_file && (dump_flags & TDF_DETAILS))
1695 fprintf (dump_file, "Candidate (%d): ", DECL_UID (var));
1696 print_generic_expr (dump_file, var, 0);
1697 fprintf (dump_file, "\n");
1705 /* Sort all accesses for the given variable, check for partial overlaps and
1706 return NULL if there are any. If there are none, pick a representative for
1707 each combination of offset and size and create a linked list out of them.
1708 Return the pointer to the first representative and make sure it is the first
1709 one in the vector of accesses. */
1711 static struct access *
1712 sort_and_splice_var_accesses (tree var)
1714 int i, j, access_count;
1715 struct access *res, **prev_acc_ptr = &res;
1716 VEC (access_p, heap) *access_vec;
1718 HOST_WIDE_INT low = -1, high = 0;
1720 access_vec = get_base_access_vector (var);
1723 access_count = VEC_length (access_p, access_vec);
1725 /* Sort by <OFFSET, SIZE>. */
1726 VEC_qsort (access_p, access_vec, compare_access_positions);
1729 while (i < access_count)
1731 struct access *access = VEC_index (access_p, access_vec, i);
1732 bool grp_write = access->write;
1733 bool grp_read = !access->write;
1734 bool grp_scalar_write = access->write
1735 && is_gimple_reg_type (access->type);
1736 bool grp_scalar_read = !access->write
1737 && is_gimple_reg_type (access->type);
1738 bool grp_assignment_read = access->grp_assignment_read;
1739 bool grp_assignment_write = access->grp_assignment_write;
1740 bool multiple_scalar_reads = false;
1741 bool total_scalarization = access->grp_total_scalarization;
1742 bool grp_partial_lhs = access->grp_partial_lhs;
1743 bool first_scalar = is_gimple_reg_type (access->type);
1744 bool unscalarizable_region = access->grp_unscalarizable_region;
1746 if (first || access->offset >= high)
1749 low = access->offset;
1750 high = access->offset + access->size;
1752 else if (access->offset > low && access->offset + access->size > high)
1755 gcc_assert (access->offset >= low
1756 && access->offset + access->size <= high);
1759 while (j < access_count)
1761 struct access *ac2 = VEC_index (access_p, access_vec, j);
1762 if (ac2->offset != access->offset || ac2->size != access->size)
1767 grp_scalar_write = (grp_scalar_write
1768 || is_gimple_reg_type (ac2->type));
1773 if (is_gimple_reg_type (ac2->type))
1775 if (grp_scalar_read)
1776 multiple_scalar_reads = true;
1778 grp_scalar_read = true;
1781 grp_assignment_read |= ac2->grp_assignment_read;
1782 grp_assignment_write |= ac2->grp_assignment_write;
1783 grp_partial_lhs |= ac2->grp_partial_lhs;
1784 unscalarizable_region |= ac2->grp_unscalarizable_region;
1785 total_scalarization |= ac2->grp_total_scalarization;
1786 relink_to_new_repr (access, ac2);
1788 /* If there are both aggregate-type and scalar-type accesses with
1789 this combination of size and offset, the comparison function
1790 should have put the scalars first. */
1791 gcc_assert (first_scalar || !is_gimple_reg_type (ac2->type));
1792 ac2->group_representative = access;
1798 access->group_representative = access;
1799 access->grp_write = grp_write;
1800 access->grp_read = grp_read;
1801 access->grp_scalar_read = grp_scalar_read;
1802 access->grp_scalar_write = grp_scalar_write;
1803 access->grp_assignment_read = grp_assignment_read;
1804 access->grp_assignment_write = grp_assignment_write;
1805 access->grp_hint = multiple_scalar_reads || total_scalarization;
1806 access->grp_total_scalarization = total_scalarization;
1807 access->grp_partial_lhs = grp_partial_lhs;
1808 access->grp_unscalarizable_region = unscalarizable_region;
1809 if (access->first_link)
1810 add_access_to_work_queue (access);
1812 *prev_acc_ptr = access;
1813 prev_acc_ptr = &access->next_grp;
1816 gcc_assert (res == VEC_index (access_p, access_vec, 0));
1820 /* Create a variable for the given ACCESS which determines the type, name and a
1821 few other properties. Return the variable declaration and store it also to
1822 ACCESS->replacement. */
1825 create_access_replacement (struct access *access, bool rename)
1829 repl = create_tmp_var (access->type, "SR");
1830 add_referenced_var (repl);
1832 mark_sym_for_renaming (repl);
1834 if (!access->grp_partial_lhs
1835 && (TREE_CODE (access->type) == COMPLEX_TYPE
1836 || TREE_CODE (access->type) == VECTOR_TYPE))
1837 DECL_GIMPLE_REG_P (repl) = 1;
1839 DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
1840 DECL_ARTIFICIAL (repl) = 1;
1841 DECL_IGNORED_P (repl) = DECL_IGNORED_P (access->base);
1843 if (DECL_NAME (access->base)
1844 && !DECL_IGNORED_P (access->base)
1845 && !DECL_ARTIFICIAL (access->base))
1847 char *pretty_name = make_fancy_name (access->expr);
1848 tree debug_expr = unshare_expr (access->expr), d;
1850 DECL_NAME (repl) = get_identifier (pretty_name);
1851 obstack_free (&name_obstack, pretty_name);
1853 /* Get rid of any SSA_NAMEs embedded in debug_expr,
1854 as DECL_DEBUG_EXPR isn't considered when looking for still
1855 used SSA_NAMEs and thus they could be freed. All debug info
1856 generation cares is whether something is constant or variable
1857 and that get_ref_base_and_extent works properly on the
1859 for (d = debug_expr; handled_component_p (d); d = TREE_OPERAND (d, 0))
1860 switch (TREE_CODE (d))
1863 case ARRAY_RANGE_REF:
1864 if (TREE_OPERAND (d, 1)
1865 && TREE_CODE (TREE_OPERAND (d, 1)) == SSA_NAME)
1866 TREE_OPERAND (d, 1) = SSA_NAME_VAR (TREE_OPERAND (d, 1));
1867 if (TREE_OPERAND (d, 3)
1868 && TREE_CODE (TREE_OPERAND (d, 3)) == SSA_NAME)
1869 TREE_OPERAND (d, 3) = SSA_NAME_VAR (TREE_OPERAND (d, 3));
1872 if (TREE_OPERAND (d, 2)
1873 && TREE_CODE (TREE_OPERAND (d, 2)) == SSA_NAME)
1874 TREE_OPERAND (d, 2) = SSA_NAME_VAR (TREE_OPERAND (d, 2));
1879 SET_DECL_DEBUG_EXPR (repl, debug_expr);
1880 DECL_DEBUG_EXPR_IS_FROM (repl) = 1;
1881 if (access->grp_no_warning)
1882 TREE_NO_WARNING (repl) = 1;
1884 TREE_NO_WARNING (repl) = TREE_NO_WARNING (access->base);
1887 TREE_NO_WARNING (repl) = 1;
1891 fprintf (dump_file, "Created a replacement for ");
1892 print_generic_expr (dump_file, access->base, 0);
1893 fprintf (dump_file, " offset: %u, size: %u: ",
1894 (unsigned) access->offset, (unsigned) access->size);
1895 print_generic_expr (dump_file, repl, 0);
1896 fprintf (dump_file, "\n");
1898 sra_stats.replacements++;
1903 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
1906 get_access_replacement (struct access *access)
1908 gcc_assert (access->grp_to_be_replaced);
1910 if (!access->replacement_decl)
1911 access->replacement_decl = create_access_replacement (access, true);
1912 return access->replacement_decl;
1915 /* Return ACCESS scalar replacement, create it if it does not exist yet but do
1916 not mark it for renaming. */
1919 get_unrenamed_access_replacement (struct access *access)
1921 gcc_assert (!access->grp_to_be_replaced);
1923 if (!access->replacement_decl)
1924 access->replacement_decl = create_access_replacement (access, false);
1925 return access->replacement_decl;
1929 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
1930 linked list along the way. Stop when *ACCESS is NULL or the access pointed
1931 to it is not "within" the root. Return false iff some accesses partially
1935 build_access_subtree (struct access **access)
1937 struct access *root = *access, *last_child = NULL;
1938 HOST_WIDE_INT limit = root->offset + root->size;
1940 *access = (*access)->next_grp;
1941 while (*access && (*access)->offset + (*access)->size <= limit)
1944 root->first_child = *access;
1946 last_child->next_sibling = *access;
1947 last_child = *access;
1949 if (!build_access_subtree (access))
1953 if (*access && (*access)->offset < limit)
1959 /* Build a tree of access representatives, ACCESS is the pointer to the first
1960 one, others are linked in a list by the next_grp field. Return false iff
1961 some accesses partially overlap. */
1964 build_access_trees (struct access *access)
1968 struct access *root = access;
1970 if (!build_access_subtree (&access))
1972 root->next_grp = access;
1977 /* Return true if expr contains some ARRAY_REFs into a variable bounded
1981 expr_with_var_bounded_array_refs_p (tree expr)
1983 while (handled_component_p (expr))
1985 if (TREE_CODE (expr) == ARRAY_REF
1986 && !host_integerp (array_ref_low_bound (expr), 0))
1988 expr = TREE_OPERAND (expr, 0);
1993 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
1994 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
1995 sorts of access flags appropriately along the way, notably always set
1996 grp_read and grp_assign_read according to MARK_READ and grp_write when
1999 Creating a replacement for a scalar access is considered beneficial if its
2000 grp_hint is set (this means we are either attempting total scalarization or
2001 there is more than one direct read access) or according to the following
2004 Access written to through a scalar type (once or more times)
2006 | Written to in an assignment statement
2008 | | Access read as scalar _once_
2010 | | | Read in an assignment statement
2012 | | | | Scalarize Comment
2013 -----------------------------------------------------------------------------
2014 0 0 0 0 No access for the scalar
2015 0 0 0 1 No access for the scalar
2016 0 0 1 0 No Single read - won't help
2017 0 0 1 1 No The same case
2018 0 1 0 0 No access for the scalar
2019 0 1 0 1 No access for the scalar
2020 0 1 1 0 Yes s = *g; return s.i;
2021 0 1 1 1 Yes The same case as above
2022 1 0 0 0 No Won't help
2023 1 0 0 1 Yes s.i = 1; *g = s;
2024 1 0 1 0 Yes s.i = 5; g = s.i;
2025 1 0 1 1 Yes The same case as above
2026 1 1 0 0 No Won't help.
2027 1 1 0 1 Yes s.i = 1; *g = s;
2028 1 1 1 0 Yes s = *g; return s.i;
2029 1 1 1 1 Yes Any of the above yeses */
2032 analyze_access_subtree (struct access *root, struct access *parent,
2033 bool allow_replacements)
2035 struct access *child;
2036 HOST_WIDE_INT limit = root->offset + root->size;
2037 HOST_WIDE_INT covered_to = root->offset;
2038 bool scalar = is_gimple_reg_type (root->type);
2039 bool hole = false, sth_created = false;
2043 if (parent->grp_read)
2045 if (parent->grp_assignment_read)
2046 root->grp_assignment_read = 1;
2047 if (parent->grp_write)
2048 root->grp_write = 1;
2049 if (parent->grp_assignment_write)
2050 root->grp_assignment_write = 1;
2051 if (parent->grp_total_scalarization)
2052 root->grp_total_scalarization = 1;
2055 if (root->grp_unscalarizable_region)
2056 allow_replacements = false;
2058 if (allow_replacements && expr_with_var_bounded_array_refs_p (root->expr))
2059 allow_replacements = false;
2061 for (child = root->first_child; child; child = child->next_sibling)
2063 hole |= covered_to < child->offset;
2064 sth_created |= analyze_access_subtree (child, root,
2065 allow_replacements && !scalar);
2067 root->grp_unscalarized_data |= child->grp_unscalarized_data;
2068 root->grp_total_scalarization &= child->grp_total_scalarization;
2069 if (child->grp_covered)
2070 covered_to += child->size;
2075 if (allow_replacements && scalar && !root->first_child
2077 || ((root->grp_scalar_read || root->grp_assignment_read)
2078 && (root->grp_scalar_write || root->grp_assignment_write))))
2080 bool new_integer_type;
2081 if (TREE_CODE (root->type) == ENUMERAL_TYPE)
2083 tree rt = root->type;
2084 root->type = build_nonstandard_integer_type (TYPE_PRECISION (rt),
2085 TYPE_UNSIGNED (rt));
2086 new_integer_type = true;
2089 new_integer_type = false;
2091 if (dump_file && (dump_flags & TDF_DETAILS))
2093 fprintf (dump_file, "Marking ");
2094 print_generic_expr (dump_file, root->base, 0);
2095 fprintf (dump_file, " offset: %u, size: %u ",
2096 (unsigned) root->offset, (unsigned) root->size);
2097 fprintf (dump_file, " to be replaced%s.\n",
2098 new_integer_type ? " with an integer": "");
2101 root->grp_to_be_replaced = 1;
2107 if (covered_to < limit)
2110 root->grp_total_scalarization = 0;
2114 && (!hole || root->grp_total_scalarization))
2116 root->grp_covered = 1;
2119 if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
2120 root->grp_unscalarized_data = 1; /* not covered and written to */
2126 /* Analyze all access trees linked by next_grp by the means of
2127 analyze_access_subtree. */
2129 analyze_access_trees (struct access *access)
2135 if (analyze_access_subtree (access, NULL, true))
2137 access = access->next_grp;
2143 /* Return true iff a potential new child of LACC at offset OFFSET and with size
2144 SIZE would conflict with an already existing one. If exactly such a child
2145 already exists in LACC, store a pointer to it in EXACT_MATCH. */
2148 child_would_conflict_in_lacc (struct access *lacc, HOST_WIDE_INT norm_offset,
2149 HOST_WIDE_INT size, struct access **exact_match)
2151 struct access *child;
2153 for (child = lacc->first_child; child; child = child->next_sibling)
2155 if (child->offset == norm_offset && child->size == size)
2157 *exact_match = child;
2161 if (child->offset < norm_offset + size
2162 && child->offset + child->size > norm_offset)
2169 /* Create a new child access of PARENT, with all properties just like MODEL
2170 except for its offset and with its grp_write false and grp_read true.
2171 Return the new access or NULL if it cannot be created. Note that this access
2172 is created long after all splicing and sorting, it's not located in any
2173 access vector and is automatically a representative of its group. */
2175 static struct access *
2176 create_artificial_child_access (struct access *parent, struct access *model,
2177 HOST_WIDE_INT new_offset)
2179 struct access *access;
2180 struct access **child;
2181 tree expr = parent->base;
2183 gcc_assert (!model->grp_unscalarizable_region);
2185 access = (struct access *) pool_alloc (access_pool);
2186 memset (access, 0, sizeof (struct access));
2187 if (!build_user_friendly_ref_for_offset (&expr, TREE_TYPE (expr), new_offset,
2190 access->grp_no_warning = true;
2191 expr = build_ref_for_model (EXPR_LOCATION (parent->base), parent->base,
2192 new_offset, model, NULL, false);
2195 access->base = parent->base;
2196 access->expr = expr;
2197 access->offset = new_offset;
2198 access->size = model->size;
2199 access->type = model->type;
2200 access->grp_write = true;
2201 access->grp_read = false;
2203 child = &parent->first_child;
2204 while (*child && (*child)->offset < new_offset)
2205 child = &(*child)->next_sibling;
2207 access->next_sibling = *child;
2214 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2215 true if any new subaccess was created. Additionally, if RACC is a scalar
2216 access but LACC is not, change the type of the latter, if possible. */
2219 propagate_subaccesses_across_link (struct access *lacc, struct access *racc)
2221 struct access *rchild;
2222 HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
2225 if (is_gimple_reg_type (lacc->type)
2226 || lacc->grp_unscalarizable_region
2227 || racc->grp_unscalarizable_region)
2230 if (!lacc->first_child && !racc->first_child
2231 && is_gimple_reg_type (racc->type))
2233 tree t = lacc->base;
2235 lacc->type = racc->type;
2236 if (build_user_friendly_ref_for_offset (&t, TREE_TYPE (t), lacc->offset,
2241 lacc->expr = build_ref_for_model (EXPR_LOCATION (lacc->base),
2242 lacc->base, lacc->offset,
2244 lacc->grp_no_warning = true;
2249 for (rchild = racc->first_child; rchild; rchild = rchild->next_sibling)
2251 struct access *new_acc = NULL;
2252 HOST_WIDE_INT norm_offset = rchild->offset + norm_delta;
2254 if (rchild->grp_unscalarizable_region)
2257 if (child_would_conflict_in_lacc (lacc, norm_offset, rchild->size,
2262 rchild->grp_hint = 1;
2263 new_acc->grp_hint |= new_acc->grp_read;
2264 if (rchild->first_child)
2265 ret |= propagate_subaccesses_across_link (new_acc, rchild);
2270 rchild->grp_hint = 1;
2271 new_acc = create_artificial_child_access (lacc, rchild, norm_offset);
2275 if (racc->first_child)
2276 propagate_subaccesses_across_link (new_acc, rchild);
2283 /* Propagate all subaccesses across assignment links. */
2286 propagate_all_subaccesses (void)
2288 while (work_queue_head)
2290 struct access *racc = pop_access_from_work_queue ();
2291 struct assign_link *link;
2293 gcc_assert (racc->first_link);
2295 for (link = racc->first_link; link; link = link->next)
2297 struct access *lacc = link->lacc;
2299 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (lacc->base)))
2301 lacc = lacc->group_representative;
2302 if (propagate_subaccesses_across_link (lacc, racc)
2303 && lacc->first_link)
2304 add_access_to_work_queue (lacc);
2309 /* Go through all accesses collected throughout the (intraprocedural) analysis
2310 stage, exclude overlapping ones, identify representatives and build trees
2311 out of them, making decisions about scalarization on the way. Return true
2312 iff there are any to-be-scalarized variables after this stage. */
2315 analyze_all_variable_accesses (void)
2318 bitmap tmp = BITMAP_ALLOC (NULL);
2320 unsigned i, max_total_scalarization_size;
2322 max_total_scalarization_size = UNITS_PER_WORD * BITS_PER_UNIT
2323 * MOVE_RATIO (optimize_function_for_speed_p (cfun));
2325 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
2326 if (bitmap_bit_p (should_scalarize_away_bitmap, i)
2327 && !bitmap_bit_p (cannot_scalarize_away_bitmap, i))
2329 tree var = referenced_var (i);
2331 if (TREE_CODE (var) == VAR_DECL
2332 && type_consists_of_records_p (TREE_TYPE (var)))
2334 if ((unsigned) tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1)
2335 <= max_total_scalarization_size)
2337 completely_scalarize_var (var);
2338 if (dump_file && (dump_flags & TDF_DETAILS))
2340 fprintf (dump_file, "Will attempt to totally scalarize ");
2341 print_generic_expr (dump_file, var, 0);
2342 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2345 else if (dump_file && (dump_flags & TDF_DETAILS))
2347 fprintf (dump_file, "Too big to totally scalarize: ");
2348 print_generic_expr (dump_file, var, 0);
2349 fprintf (dump_file, " (UID: %u)\n", DECL_UID (var));
2354 bitmap_copy (tmp, candidate_bitmap);
2355 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2357 tree var = referenced_var (i);
2358 struct access *access;
2360 access = sort_and_splice_var_accesses (var);
2361 if (!access || !build_access_trees (access))
2362 disqualify_candidate (var,
2363 "No or inhibitingly overlapping accesses.");
2366 propagate_all_subaccesses ();
2368 bitmap_copy (tmp, candidate_bitmap);
2369 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2371 tree var = referenced_var (i);
2372 struct access *access = get_first_repr_for_decl (var);
2374 if (analyze_access_trees (access))
2377 if (dump_file && (dump_flags & TDF_DETAILS))
2379 fprintf (dump_file, "\nAccess trees for ");
2380 print_generic_expr (dump_file, var, 0);
2381 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2382 dump_access_tree (dump_file, access);
2383 fprintf (dump_file, "\n");
2387 disqualify_candidate (var, "No scalar replacements to be created.");
2394 statistics_counter_event (cfun, "Scalarized aggregates", res);
2401 /* Generate statements copying scalar replacements of accesses within a subtree
2402 into or out of AGG. ACCESS, all its children, siblings and their children
2403 are to be processed. AGG is an aggregate type expression (can be a
2404 declaration but does not have to be, it can for example also be a mem_ref or
2405 a series of handled components). TOP_OFFSET is the offset of the processed
2406 subtree which has to be subtracted from offsets of individual accesses to
2407 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2408 replacements in the interval <start_offset, start_offset + chunk_size>,
2409 otherwise copy all. GSI is a statement iterator used to place the new
2410 statements. WRITE should be true when the statements should write from AGG
2411 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2412 statements will be added after the current statement in GSI, they will be
2413 added before the statement otherwise. */
2416 generate_subtree_copies (struct access *access, tree agg,
2417 HOST_WIDE_INT top_offset,
2418 HOST_WIDE_INT start_offset, HOST_WIDE_INT chunk_size,
2419 gimple_stmt_iterator *gsi, bool write,
2420 bool insert_after, location_t loc)
2424 if (chunk_size && access->offset >= start_offset + chunk_size)
2427 if (access->grp_to_be_replaced
2429 || access->offset + access->size > start_offset))
2431 tree expr, repl = get_access_replacement (access);
2434 expr = build_ref_for_model (loc, agg, access->offset - top_offset,
2435 access, gsi, insert_after);
2439 if (access->grp_partial_lhs)
2440 expr = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE,
2442 insert_after ? GSI_NEW_STMT
2444 stmt = gimple_build_assign (repl, expr);
2448 TREE_NO_WARNING (repl) = 1;
2449 if (access->grp_partial_lhs)
2450 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2452 insert_after ? GSI_NEW_STMT
2454 stmt = gimple_build_assign (expr, repl);
2456 gimple_set_location (stmt, loc);
2459 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2461 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2463 sra_stats.subtree_copies++;
2466 if (access->first_child)
2467 generate_subtree_copies (access->first_child, agg, top_offset,
2468 start_offset, chunk_size, gsi,
2469 write, insert_after, loc);
2471 access = access->next_sibling;
2476 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2477 the root of the subtree to be processed. GSI is the statement iterator used
2478 for inserting statements which are added after the current statement if
2479 INSERT_AFTER is true or before it otherwise. */
2482 init_subtree_with_zero (struct access *access, gimple_stmt_iterator *gsi,
2483 bool insert_after, location_t loc)
2486 struct access *child;
2488 if (access->grp_to_be_replaced)
2492 stmt = gimple_build_assign (get_access_replacement (access),
2493 build_zero_cst (access->type));
2495 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2497 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2499 gimple_set_location (stmt, loc);
2502 for (child = access->first_child; child; child = child->next_sibling)
2503 init_subtree_with_zero (child, gsi, insert_after, loc);
2506 /* Search for an access representative for the given expression EXPR and
2507 return it or NULL if it cannot be found. */
2509 static struct access *
2510 get_access_for_expr (tree expr)
2512 HOST_WIDE_INT offset, size, max_size;
2515 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2516 a different size than the size of its argument and we need the latter
2518 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
2519 expr = TREE_OPERAND (expr, 0);
2521 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
2522 if (max_size == -1 || !DECL_P (base))
2525 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
2528 return get_var_base_offset_size_access (base, offset, max_size);
2531 /* Replace the expression EXPR with a scalar replacement if there is one and
2532 generate other statements to do type conversion or subtree copying if
2533 necessary. GSI is used to place newly created statements, WRITE is true if
2534 the expression is being written to (it is on a LHS of a statement or output
2535 in an assembly statement). */
2538 sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write)
2541 struct access *access;
2544 if (TREE_CODE (*expr) == BIT_FIELD_REF)
2547 expr = &TREE_OPERAND (*expr, 0);
2552 if (TREE_CODE (*expr) == REALPART_EXPR || TREE_CODE (*expr) == IMAGPART_EXPR)
2553 expr = &TREE_OPERAND (*expr, 0);
2554 access = get_access_for_expr (*expr);
2557 type = TREE_TYPE (*expr);
2559 loc = gimple_location (gsi_stmt (*gsi));
2560 if (access->grp_to_be_replaced)
2562 tree repl = get_access_replacement (access);
2563 /* If we replace a non-register typed access simply use the original
2564 access expression to extract the scalar component afterwards.
2565 This happens if scalarizing a function return value or parameter
2566 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2567 gcc.c-torture/compile/20011217-1.c.
2569 We also want to use this when accessing a complex or vector which can
2570 be accessed as a different type too, potentially creating a need for
2571 type conversion (see PR42196) and when scalarized unions are involved
2572 in assembler statements (see PR42398). */
2573 if (!useless_type_conversion_p (type, access->type))
2577 ref = build_ref_for_model (loc, access->base, access->offset, access,
2584 if (access->grp_partial_lhs)
2585 ref = force_gimple_operand_gsi (gsi, ref, true, NULL_TREE,
2586 false, GSI_NEW_STMT);
2587 stmt = gimple_build_assign (repl, ref);
2588 gimple_set_location (stmt, loc);
2589 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2595 if (access->grp_partial_lhs)
2596 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2597 true, GSI_SAME_STMT);
2598 stmt = gimple_build_assign (ref, repl);
2599 gimple_set_location (stmt, loc);
2600 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2608 if (access->first_child)
2610 HOST_WIDE_INT start_offset, chunk_size;
2612 && host_integerp (TREE_OPERAND (bfr, 1), 1)
2613 && host_integerp (TREE_OPERAND (bfr, 2), 1))
2615 chunk_size = tree_low_cst (TREE_OPERAND (bfr, 1), 1);
2616 start_offset = access->offset
2617 + tree_low_cst (TREE_OPERAND (bfr, 2), 1);
2620 start_offset = chunk_size = 0;
2622 generate_subtree_copies (access->first_child, access->base, 0,
2623 start_offset, chunk_size, gsi, write, write,
2629 /* Where scalar replacements of the RHS have been written to when a replacement
2630 of a LHS of an assigments cannot be direclty loaded from a replacement of
2632 enum unscalarized_data_handling { SRA_UDH_NONE, /* Nothing done so far. */
2633 SRA_UDH_RIGHT, /* Data flushed to the RHS. */
2634 SRA_UDH_LEFT }; /* Data flushed to the LHS. */
2636 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2637 base aggregate if there are unscalarized data or directly to LHS of the
2638 statement that is pointed to by GSI otherwise. */
2640 static enum unscalarized_data_handling
2641 handle_unscalarized_data_in_subtree (struct access *top_racc,
2642 gimple_stmt_iterator *gsi)
2644 if (top_racc->grp_unscalarized_data)
2646 generate_subtree_copies (top_racc->first_child, top_racc->base, 0, 0, 0,
2648 gimple_location (gsi_stmt (*gsi)));
2649 return SRA_UDH_RIGHT;
2653 tree lhs = gimple_assign_lhs (gsi_stmt (*gsi));
2654 generate_subtree_copies (top_racc->first_child, lhs, top_racc->offset,
2655 0, 0, gsi, false, false,
2656 gimple_location (gsi_stmt (*gsi)));
2657 return SRA_UDH_LEFT;
2662 /* Try to generate statements to load all sub-replacements in an access subtree
2663 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2664 If that is not possible, refresh the TOP_RACC base aggregate and load the
2665 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2666 copied. NEW_GSI is stmt iterator used for statement insertions after the
2667 original assignment, OLD_GSI is used to insert statements before the
2668 assignment. *REFRESHED keeps the information whether we have needed to
2669 refresh replacements of the LHS and from which side of the assignments this
2673 load_assign_lhs_subreplacements (struct access *lacc, struct access *top_racc,
2674 HOST_WIDE_INT left_offset,
2675 gimple_stmt_iterator *old_gsi,
2676 gimple_stmt_iterator *new_gsi,
2677 enum unscalarized_data_handling *refreshed)
2679 location_t loc = gimple_location (gsi_stmt (*old_gsi));
2680 for (lacc = lacc->first_child; lacc; lacc = lacc->next_sibling)
2682 if (lacc->grp_to_be_replaced)
2684 struct access *racc;
2685 HOST_WIDE_INT offset = lacc->offset - left_offset + top_racc->offset;
2689 racc = find_access_in_subtree (top_racc, offset, lacc->size);
2690 if (racc && racc->grp_to_be_replaced)
2692 rhs = get_access_replacement (racc);
2693 if (!useless_type_conversion_p (lacc->type, racc->type))
2694 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, lacc->type, rhs);
2696 if (racc->grp_partial_lhs && lacc->grp_partial_lhs)
2697 rhs = force_gimple_operand_gsi (old_gsi, rhs, true, NULL_TREE,
2698 true, GSI_SAME_STMT);
2702 /* No suitable access on the right hand side, need to load from
2703 the aggregate. See if we have to update it first... */
2704 if (*refreshed == SRA_UDH_NONE)
2705 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2708 if (*refreshed == SRA_UDH_LEFT)
2709 rhs = build_ref_for_model (loc, lacc->base, lacc->offset, lacc,
2712 rhs = build_ref_for_model (loc, top_racc->base, offset, lacc,
2716 stmt = gimple_build_assign (get_access_replacement (lacc), rhs);
2717 gsi_insert_after (new_gsi, stmt, GSI_NEW_STMT);
2718 gimple_set_location (stmt, loc);
2720 sra_stats.subreplacements++;
2722 else if (*refreshed == SRA_UDH_NONE
2723 && lacc->grp_read && !lacc->grp_covered)
2724 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2727 if (lacc->first_child)
2728 load_assign_lhs_subreplacements (lacc, top_racc, left_offset,
2729 old_gsi, new_gsi, refreshed);
2733 /* Result code for SRA assignment modification. */
2734 enum assignment_mod_result { SRA_AM_NONE, /* nothing done for the stmt */
2735 SRA_AM_MODIFIED, /* stmt changed but not
2737 SRA_AM_REMOVED }; /* stmt eliminated */
2739 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2740 to the assignment and GSI is the statement iterator pointing at it. Returns
2741 the same values as sra_modify_assign. */
2743 static enum assignment_mod_result
2744 sra_modify_constructor_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2746 tree lhs = gimple_assign_lhs (*stmt);
2750 acc = get_access_for_expr (lhs);
2754 loc = gimple_location (*stmt);
2755 if (VEC_length (constructor_elt,
2756 CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt))) > 0)
2758 /* I have never seen this code path trigger but if it can happen the
2759 following should handle it gracefully. */
2760 if (access_has_children_p (acc))
2761 generate_subtree_copies (acc->first_child, acc->base, 0, 0, 0, gsi,
2763 return SRA_AM_MODIFIED;
2766 if (acc->grp_covered)
2768 init_subtree_with_zero (acc, gsi, false, loc);
2769 unlink_stmt_vdef (*stmt);
2770 gsi_remove (gsi, true);
2771 return SRA_AM_REMOVED;
2775 init_subtree_with_zero (acc, gsi, true, loc);
2776 return SRA_AM_MODIFIED;
2780 /* Create and return a new suitable default definition SSA_NAME for RACC which
2781 is an access describing an uninitialized part of an aggregate that is being
2785 get_repl_default_def_ssa_name (struct access *racc)
2789 decl = get_unrenamed_access_replacement (racc);
2791 repl = gimple_default_def (cfun, decl);
2794 repl = make_ssa_name (decl, gimple_build_nop ());
2795 set_default_def (decl, repl);
2801 /* Return true if REF has a COMPONENT_REF with a bit-field field declaration
2805 contains_bitfld_comp_ref_p (const_tree ref)
2807 while (handled_component_p (ref))
2809 if (TREE_CODE (ref) == COMPONENT_REF
2810 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1)))
2812 ref = TREE_OPERAND (ref, 0);
2818 /* Return true if REF has an VIEW_CONVERT_EXPR or a COMPONENT_REF with a
2819 bit-field field declaration somewhere in it. */
2822 contains_vce_or_bfcref_p (const_tree ref)
2824 while (handled_component_p (ref))
2826 if (TREE_CODE (ref) == VIEW_CONVERT_EXPR
2827 || (TREE_CODE (ref) == COMPONENT_REF
2828 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))))
2830 ref = TREE_OPERAND (ref, 0);
2836 /* Examine both sides of the assignment statement pointed to by STMT, replace
2837 them with a scalare replacement if there is one and generate copying of
2838 replacements if scalarized aggregates have been used in the assignment. GSI
2839 is used to hold generated statements for type conversions and subtree
2842 static enum assignment_mod_result
2843 sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2845 struct access *lacc, *racc;
2847 bool modify_this_stmt = false;
2848 bool force_gimple_rhs = false;
2850 gimple_stmt_iterator orig_gsi = *gsi;
2852 if (!gimple_assign_single_p (*stmt))
2854 lhs = gimple_assign_lhs (*stmt);
2855 rhs = gimple_assign_rhs1 (*stmt);
2857 if (TREE_CODE (rhs) == CONSTRUCTOR)
2858 return sra_modify_constructor_assign (stmt, gsi);
2860 if (TREE_CODE (rhs) == REALPART_EXPR || TREE_CODE (lhs) == REALPART_EXPR
2861 || TREE_CODE (rhs) == IMAGPART_EXPR || TREE_CODE (lhs) == IMAGPART_EXPR
2862 || TREE_CODE (rhs) == BIT_FIELD_REF || TREE_CODE (lhs) == BIT_FIELD_REF)
2864 modify_this_stmt = sra_modify_expr (gimple_assign_rhs1_ptr (*stmt),
2866 modify_this_stmt |= sra_modify_expr (gimple_assign_lhs_ptr (*stmt),
2868 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
2871 lacc = get_access_for_expr (lhs);
2872 racc = get_access_for_expr (rhs);
2876 loc = gimple_location (*stmt);
2877 if (lacc && lacc->grp_to_be_replaced)
2879 lhs = get_access_replacement (lacc);
2880 gimple_assign_set_lhs (*stmt, lhs);
2881 modify_this_stmt = true;
2882 if (lacc->grp_partial_lhs)
2883 force_gimple_rhs = true;
2887 if (racc && racc->grp_to_be_replaced)
2889 rhs = get_access_replacement (racc);
2890 modify_this_stmt = true;
2891 if (racc->grp_partial_lhs)
2892 force_gimple_rhs = true;
2896 if (modify_this_stmt)
2898 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2900 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
2901 ??? This should move to fold_stmt which we simply should
2902 call after building a VIEW_CONVERT_EXPR here. */
2903 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
2904 && !contains_bitfld_comp_ref_p (lhs)
2905 && !access_has_children_p (lacc))
2907 lhs = build_ref_for_model (loc, lhs, 0, racc, gsi, false);
2908 gimple_assign_set_lhs (*stmt, lhs);
2910 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs))
2911 && !contains_vce_or_bfcref_p (rhs)
2912 && !access_has_children_p (racc))
2913 rhs = build_ref_for_model (loc, rhs, 0, lacc, gsi, false);
2915 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2917 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, TREE_TYPE (lhs),
2919 if (is_gimple_reg_type (TREE_TYPE (lhs))
2920 && TREE_CODE (lhs) != SSA_NAME)
2921 force_gimple_rhs = true;
2926 /* From this point on, the function deals with assignments in between
2927 aggregates when at least one has scalar reductions of some of its
2928 components. There are three possible scenarios: Both the LHS and RHS have
2929 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
2931 In the first case, we would like to load the LHS components from RHS
2932 components whenever possible. If that is not possible, we would like to
2933 read it directly from the RHS (after updating it by storing in it its own
2934 components). If there are some necessary unscalarized data in the LHS,
2935 those will be loaded by the original assignment too. If neither of these
2936 cases happen, the original statement can be removed. Most of this is done
2937 by load_assign_lhs_subreplacements.
2939 In the second case, we would like to store all RHS scalarized components
2940 directly into LHS and if they cover the aggregate completely, remove the
2941 statement too. In the third case, we want the LHS components to be loaded
2942 directly from the RHS (DSE will remove the original statement if it
2945 This is a bit complex but manageable when types match and when unions do
2946 not cause confusion in a way that we cannot really load a component of LHS
2947 from the RHS or vice versa (the access representing this level can have
2948 subaccesses that are accessible only through a different union field at a
2949 higher level - different from the one used in the examined expression).
2952 Therefore, I specially handle a fourth case, happening when there is a
2953 specific type cast or it is impossible to locate a scalarized subaccess on
2954 the other side of the expression. If that happens, I simply "refresh" the
2955 RHS by storing in it is scalarized components leave the original statement
2956 there to do the copying and then load the scalar replacements of the LHS.
2957 This is what the first branch does. */
2959 if (modify_this_stmt
2960 || gimple_has_volatile_ops (*stmt)
2961 || contains_vce_or_bfcref_p (rhs)
2962 || contains_vce_or_bfcref_p (lhs))
2964 if (access_has_children_p (racc))
2965 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
2966 gsi, false, false, loc);
2967 if (access_has_children_p (lacc))
2968 generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
2969 gsi, true, true, loc);
2970 sra_stats.separate_lhs_rhs_handling++;
2974 if (access_has_children_p (lacc) && access_has_children_p (racc))
2976 gimple_stmt_iterator orig_gsi = *gsi;
2977 enum unscalarized_data_handling refreshed;
2979 if (lacc->grp_read && !lacc->grp_covered)
2980 refreshed = handle_unscalarized_data_in_subtree (racc, gsi);
2982 refreshed = SRA_UDH_NONE;
2984 load_assign_lhs_subreplacements (lacc, racc, lacc->offset,
2985 &orig_gsi, gsi, &refreshed);
2986 if (refreshed != SRA_UDH_RIGHT)
2989 unlink_stmt_vdef (*stmt);
2990 gsi_remove (&orig_gsi, true);
2991 sra_stats.deleted++;
2992 return SRA_AM_REMOVED;
2999 if (!racc->grp_to_be_replaced && !racc->grp_unscalarized_data)
3003 fprintf (dump_file, "Removing load: ");
3004 print_gimple_stmt (dump_file, *stmt, 0, 0);
3007 if (TREE_CODE (lhs) == SSA_NAME)
3009 rhs = get_repl_default_def_ssa_name (racc);
3010 if (!useless_type_conversion_p (TREE_TYPE (lhs),
3012 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR,
3013 TREE_TYPE (lhs), rhs);
3017 if (racc->first_child)
3018 generate_subtree_copies (racc->first_child, lhs,
3019 racc->offset, 0, 0, gsi,
3022 gcc_assert (*stmt == gsi_stmt (*gsi));
3023 unlink_stmt_vdef (*stmt);
3024 gsi_remove (gsi, true);
3025 sra_stats.deleted++;
3026 return SRA_AM_REMOVED;
3029 else if (racc->first_child)
3030 generate_subtree_copies (racc->first_child, lhs, racc->offset,
3031 0, 0, gsi, false, true, loc);
3033 if (access_has_children_p (lacc))
3034 generate_subtree_copies (lacc->first_child, rhs, lacc->offset,
3035 0, 0, gsi, true, true, loc);
3039 /* This gimplification must be done after generate_subtree_copies, lest we
3040 insert the subtree copies in the middle of the gimplified sequence. */
3041 if (force_gimple_rhs)
3042 rhs = force_gimple_operand_gsi (&orig_gsi, rhs, true, NULL_TREE,
3043 true, GSI_SAME_STMT);
3044 if (gimple_assign_rhs1 (*stmt) != rhs)
3046 modify_this_stmt = true;
3047 gimple_assign_set_rhs_from_tree (&orig_gsi, rhs);
3048 gcc_assert (*stmt == gsi_stmt (orig_gsi));
3051 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3054 /* Traverse the function body and all modifications as decided in
3055 analyze_all_variable_accesses. Return true iff the CFG has been
3059 sra_modify_function_body (void)
3061 bool cfg_changed = false;
3066 gimple_stmt_iterator gsi = gsi_start_bb (bb);
3067 while (!gsi_end_p (gsi))
3069 gimple stmt = gsi_stmt (gsi);
3070 enum assignment_mod_result assign_result;
3071 bool modified = false, deleted = false;
3075 switch (gimple_code (stmt))
3078 t = gimple_return_retval_ptr (stmt);
3079 if (*t != NULL_TREE)
3080 modified |= sra_modify_expr (t, &gsi, false);
3084 assign_result = sra_modify_assign (&stmt, &gsi);
3085 modified |= assign_result == SRA_AM_MODIFIED;
3086 deleted = assign_result == SRA_AM_REMOVED;
3090 /* Operands must be processed before the lhs. */
3091 for (i = 0; i < gimple_call_num_args (stmt); i++)
3093 t = gimple_call_arg_ptr (stmt, i);
3094 modified |= sra_modify_expr (t, &gsi, false);
3097 if (gimple_call_lhs (stmt))
3099 t = gimple_call_lhs_ptr (stmt);
3100 modified |= sra_modify_expr (t, &gsi, true);
3105 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
3107 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
3108 modified |= sra_modify_expr (t, &gsi, false);
3110 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
3112 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
3113 modified |= sra_modify_expr (t, &gsi, true);
3124 if (maybe_clean_eh_stmt (stmt)
3125 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
3136 /* Generate statements initializing scalar replacements of parts of function
3140 initialize_parameter_reductions (void)
3142 gimple_stmt_iterator gsi;
3143 gimple_seq seq = NULL;
3146 for (parm = DECL_ARGUMENTS (current_function_decl);
3148 parm = DECL_CHAIN (parm))
3150 VEC (access_p, heap) *access_vec;
3151 struct access *access;
3153 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3155 access_vec = get_base_access_vector (parm);
3161 seq = gimple_seq_alloc ();
3162 gsi = gsi_start (seq);
3165 for (access = VEC_index (access_p, access_vec, 0);
3167 access = access->next_grp)
3168 generate_subtree_copies (access, parm, 0, 0, 0, &gsi, true, true,
3169 EXPR_LOCATION (parm));
3173 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR), seq);
3176 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
3177 it reveals there are components of some aggregates to be scalarized, it runs
3178 the required transformations. */
3180 perform_intra_sra (void)
3185 if (!find_var_candidates ())
3188 if (!scan_function ())
3191 if (!analyze_all_variable_accesses ())
3194 if (sra_modify_function_body ())
3195 ret = TODO_update_ssa | TODO_cleanup_cfg;
3197 ret = TODO_update_ssa;
3198 initialize_parameter_reductions ();
3200 statistics_counter_event (cfun, "Scalar replacements created",
3201 sra_stats.replacements);
3202 statistics_counter_event (cfun, "Modified expressions", sra_stats.exprs);
3203 statistics_counter_event (cfun, "Subtree copy stmts",
3204 sra_stats.subtree_copies);
3205 statistics_counter_event (cfun, "Subreplacement stmts",
3206 sra_stats.subreplacements);
3207 statistics_counter_event (cfun, "Deleted stmts", sra_stats.deleted);
3208 statistics_counter_event (cfun, "Separate LHS and RHS handling",
3209 sra_stats.separate_lhs_rhs_handling);
3212 sra_deinitialize ();
3216 /* Perform early intraprocedural SRA. */
3218 early_intra_sra (void)
3220 sra_mode = SRA_MODE_EARLY_INTRA;
3221 return perform_intra_sra ();
3224 /* Perform "late" intraprocedural SRA. */
3226 late_intra_sra (void)
3228 sra_mode = SRA_MODE_INTRA;
3229 return perform_intra_sra ();
3234 gate_intra_sra (void)
3236 return flag_tree_sra != 0 && dbg_cnt (tree_sra);
3240 struct gimple_opt_pass pass_sra_early =
3245 gate_intra_sra, /* gate */
3246 early_intra_sra, /* execute */
3249 0, /* static_pass_number */
3250 TV_TREE_SRA, /* tv_id */
3251 PROP_cfg | PROP_ssa, /* properties_required */
3252 0, /* properties_provided */
3253 0, /* properties_destroyed */
3254 0, /* todo_flags_start */
3257 | TODO_verify_ssa /* todo_flags_finish */
3261 struct gimple_opt_pass pass_sra =
3266 gate_intra_sra, /* gate */
3267 late_intra_sra, /* execute */
3270 0, /* static_pass_number */
3271 TV_TREE_SRA, /* tv_id */
3272 PROP_cfg | PROP_ssa, /* properties_required */
3273 0, /* properties_provided */
3274 0, /* properties_destroyed */
3275 TODO_update_address_taken, /* todo_flags_start */
3278 | TODO_verify_ssa /* todo_flags_finish */
3283 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3287 is_unused_scalar_param (tree parm)
3290 return (is_gimple_reg (parm)
3291 && (!(name = gimple_default_def (cfun, parm))
3292 || has_zero_uses (name)));
3295 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3296 examine whether there are any direct or otherwise infeasible ones. If so,
3297 return true, otherwise return false. PARM must be a gimple register with a
3298 non-NULL default definition. */
3301 ptr_parm_has_direct_uses (tree parm)
3303 imm_use_iterator ui;
3305 tree name = gimple_default_def (cfun, parm);
3308 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
3311 use_operand_p use_p;
3313 if (is_gimple_debug (stmt))
3316 /* Valid uses include dereferences on the lhs and the rhs. */
3317 if (gimple_has_lhs (stmt))
3319 tree lhs = gimple_get_lhs (stmt);
3320 while (handled_component_p (lhs))
3321 lhs = TREE_OPERAND (lhs, 0);
3322 if (TREE_CODE (lhs) == MEM_REF
3323 && TREE_OPERAND (lhs, 0) == name
3324 && integer_zerop (TREE_OPERAND (lhs, 1))
3325 && types_compatible_p (TREE_TYPE (lhs),
3326 TREE_TYPE (TREE_TYPE (name)))
3327 && !TREE_THIS_VOLATILE (lhs))
3330 if (gimple_assign_single_p (stmt))
3332 tree rhs = gimple_assign_rhs1 (stmt);
3333 while (handled_component_p (rhs))
3334 rhs = TREE_OPERAND (rhs, 0);
3335 if (TREE_CODE (rhs) == MEM_REF
3336 && TREE_OPERAND (rhs, 0) == name
3337 && integer_zerop (TREE_OPERAND (rhs, 1))
3338 && types_compatible_p (TREE_TYPE (rhs),
3339 TREE_TYPE (TREE_TYPE (name)))
3340 && !TREE_THIS_VOLATILE (rhs))
3343 else if (is_gimple_call (stmt))
3346 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3348 tree arg = gimple_call_arg (stmt, i);
3349 while (handled_component_p (arg))
3350 arg = TREE_OPERAND (arg, 0);
3351 if (TREE_CODE (arg) == MEM_REF
3352 && TREE_OPERAND (arg, 0) == name
3353 && integer_zerop (TREE_OPERAND (arg, 1))
3354 && types_compatible_p (TREE_TYPE (arg),
3355 TREE_TYPE (TREE_TYPE (name)))
3356 && !TREE_THIS_VOLATILE (arg))
3361 /* If the number of valid uses does not match the number of
3362 uses in this stmt there is an unhandled use. */
3363 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
3370 BREAK_FROM_IMM_USE_STMT (ui);
3376 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3377 them in candidate_bitmap. Note that these do not necessarily include
3378 parameter which are unused and thus can be removed. Return true iff any
3379 such candidate has been found. */
3382 find_param_candidates (void)
3389 for (parm = DECL_ARGUMENTS (current_function_decl);
3391 parm = DECL_CHAIN (parm))
3393 tree type = TREE_TYPE (parm);
3397 if (TREE_THIS_VOLATILE (parm)
3398 || TREE_ADDRESSABLE (parm)
3399 || (!is_gimple_reg_type (type) && is_va_list_type (type)))
3402 if (is_unused_scalar_param (parm))
3408 if (POINTER_TYPE_P (type))
3410 type = TREE_TYPE (type);
3412 if (TREE_CODE (type) == FUNCTION_TYPE
3413 || TYPE_VOLATILE (type)
3414 || (TREE_CODE (type) == ARRAY_TYPE
3415 && TYPE_NONALIASED_COMPONENT (type))
3416 || !is_gimple_reg (parm)
3417 || is_va_list_type (type)
3418 || ptr_parm_has_direct_uses (parm))
3421 else if (!AGGREGATE_TYPE_P (type))
3424 if (!COMPLETE_TYPE_P (type)
3425 || !host_integerp (TYPE_SIZE (type), 1)
3426 || tree_low_cst (TYPE_SIZE (type), 1) == 0
3427 || (AGGREGATE_TYPE_P (type)
3428 && type_internals_preclude_sra_p (type, &msg)))
3431 bitmap_set_bit (candidate_bitmap, DECL_UID (parm));
3433 if (dump_file && (dump_flags & TDF_DETAILS))
3435 fprintf (dump_file, "Candidate (%d): ", DECL_UID (parm));
3436 print_generic_expr (dump_file, parm, 0);
3437 fprintf (dump_file, "\n");
3441 func_param_count = count;
3445 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3449 mark_maybe_modified (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef ATTRIBUTE_UNUSED,
3452 struct access *repr = (struct access *) data;
3454 repr->grp_maybe_modified = 1;
3458 /* Analyze what representatives (in linked lists accessible from
3459 REPRESENTATIVES) can be modified by side effects of statements in the
3460 current function. */
3463 analyze_modified_params (VEC (access_p, heap) *representatives)
3467 for (i = 0; i < func_param_count; i++)
3469 struct access *repr;
3471 for (repr = VEC_index (access_p, representatives, i);
3473 repr = repr->next_grp)
3475 struct access *access;
3479 if (no_accesses_p (repr))
3481 if (!POINTER_TYPE_P (TREE_TYPE (repr->base))
3482 || repr->grp_maybe_modified)
3485 ao_ref_init (&ar, repr->expr);
3486 visited = BITMAP_ALLOC (NULL);
3487 for (access = repr; access; access = access->next_sibling)
3489 /* All accesses are read ones, otherwise grp_maybe_modified would
3490 be trivially set. */
3491 walk_aliased_vdefs (&ar, gimple_vuse (access->stmt),
3492 mark_maybe_modified, repr, &visited);
3493 if (repr->grp_maybe_modified)
3496 BITMAP_FREE (visited);
3501 /* Propagate distances in bb_dereferences in the opposite direction than the
3502 control flow edges, in each step storing the maximum of the current value
3503 and the minimum of all successors. These steps are repeated until the table
3504 stabilizes. Note that BBs which might terminate the functions (according to
3505 final_bbs bitmap) never updated in this way. */
3508 propagate_dereference_distances (void)
3510 VEC (basic_block, heap) *queue;
3513 queue = VEC_alloc (basic_block, heap, last_basic_block_for_function (cfun));
3514 VEC_quick_push (basic_block, queue, ENTRY_BLOCK_PTR);
3517 VEC_quick_push (basic_block, queue, bb);
3521 while (!VEC_empty (basic_block, queue))
3525 bool change = false;
3528 bb = VEC_pop (basic_block, queue);
3531 if (bitmap_bit_p (final_bbs, bb->index))
3534 for (i = 0; i < func_param_count; i++)
3536 int idx = bb->index * func_param_count + i;
3538 HOST_WIDE_INT inh = 0;
3540 FOR_EACH_EDGE (e, ei, bb->succs)
3542 int succ_idx = e->dest->index * func_param_count + i;
3544 if (e->src == EXIT_BLOCK_PTR)
3550 inh = bb_dereferences [succ_idx];
3552 else if (bb_dereferences [succ_idx] < inh)
3553 inh = bb_dereferences [succ_idx];
3556 if (!first && bb_dereferences[idx] < inh)
3558 bb_dereferences[idx] = inh;
3563 if (change && !bitmap_bit_p (final_bbs, bb->index))
3564 FOR_EACH_EDGE (e, ei, bb->preds)
3569 e->src->aux = e->src;
3570 VEC_quick_push (basic_block, queue, e->src);
3574 VEC_free (basic_block, heap, queue);
3577 /* Dump a dereferences TABLE with heading STR to file F. */
3580 dump_dereferences_table (FILE *f, const char *str, HOST_WIDE_INT *table)
3584 fprintf (dump_file, str);
3585 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
3587 fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index));
3588 if (bb != EXIT_BLOCK_PTR)
3591 for (i = 0; i < func_param_count; i++)
3593 int idx = bb->index * func_param_count + i;
3594 fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", table[idx]);
3599 fprintf (dump_file, "\n");
3602 /* Determine what (parts of) parameters passed by reference that are not
3603 assigned to are not certainly dereferenced in this function and thus the
3604 dereferencing cannot be safely moved to the caller without potentially
3605 introducing a segfault. Mark such REPRESENTATIVES as
3606 grp_not_necessarilly_dereferenced.
3608 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3609 part is calculated rather than simple booleans are calculated for each
3610 pointer parameter to handle cases when only a fraction of the whole
3611 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3614 The maximum dereference distances for each pointer parameter and BB are
3615 already stored in bb_dereference. This routine simply propagates these
3616 values upwards by propagate_dereference_distances and then compares the
3617 distances of individual parameters in the ENTRY BB to the equivalent
3618 distances of each representative of a (fraction of a) parameter. */
3621 analyze_caller_dereference_legality (VEC (access_p, heap) *representatives)
3625 if (dump_file && (dump_flags & TDF_DETAILS))
3626 dump_dereferences_table (dump_file,
3627 "Dereference table before propagation:\n",
3630 propagate_dereference_distances ();
3632 if (dump_file && (dump_flags & TDF_DETAILS))
3633 dump_dereferences_table (dump_file,
3634 "Dereference table after propagation:\n",
3637 for (i = 0; i < func_param_count; i++)
3639 struct access *repr = VEC_index (access_p, representatives, i);
3640 int idx = ENTRY_BLOCK_PTR->index * func_param_count + i;
3642 if (!repr || no_accesses_p (repr))
3647 if ((repr->offset + repr->size) > bb_dereferences[idx])
3648 repr->grp_not_necessarilly_dereferenced = 1;
3649 repr = repr->next_grp;
3655 /* Return the representative access for the parameter declaration PARM if it is
3656 a scalar passed by reference which is not written to and the pointer value
3657 is not used directly. Thus, if it is legal to dereference it in the caller
3658 and we can rule out modifications through aliases, such parameter should be
3659 turned into one passed by value. Return NULL otherwise. */
3661 static struct access *
3662 unmodified_by_ref_scalar_representative (tree parm)
3664 int i, access_count;
3665 struct access *repr;
3666 VEC (access_p, heap) *access_vec;
3668 access_vec = get_base_access_vector (parm);
3669 gcc_assert (access_vec);
3670 repr = VEC_index (access_p, access_vec, 0);
3673 repr->group_representative = repr;
3675 access_count = VEC_length (access_p, access_vec);
3676 for (i = 1; i < access_count; i++)
3678 struct access *access = VEC_index (access_p, access_vec, i);
3681 access->group_representative = repr;
3682 access->next_sibling = repr->next_sibling;
3683 repr->next_sibling = access;
3687 repr->grp_scalar_ptr = 1;
3691 /* Return true iff this access precludes IPA-SRA of the parameter it is
3695 access_precludes_ipa_sra_p (struct access *access)
3697 /* Avoid issues such as the second simple testcase in PR 42025. The problem
3698 is incompatible assign in a call statement (and possibly even in asm
3699 statements). This can be relaxed by using a new temporary but only for
3700 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
3701 intraprocedural SRA we deal with this by keeping the old aggregate around,
3702 something we cannot do in IPA-SRA.) */
3704 && (is_gimple_call (access->stmt)
3705 || gimple_code (access->stmt) == GIMPLE_ASM))
3708 if (tree_non_mode_aligned_mem_p (access->expr))
3715 /* Sort collected accesses for parameter PARM, identify representatives for
3716 each accessed region and link them together. Return NULL if there are
3717 different but overlapping accesses, return the special ptr value meaning
3718 there are no accesses for this parameter if that is the case and return the
3719 first representative otherwise. Set *RO_GRP if there is a group of accesses
3720 with only read (i.e. no write) accesses. */
3722 static struct access *
3723 splice_param_accesses (tree parm, bool *ro_grp)
3725 int i, j, access_count, group_count;
3726 int agg_size, total_size = 0;
3727 struct access *access, *res, **prev_acc_ptr = &res;
3728 VEC (access_p, heap) *access_vec;
3730 access_vec = get_base_access_vector (parm);
3732 return &no_accesses_representant;
3733 access_count = VEC_length (access_p, access_vec);
3735 VEC_qsort (access_p, access_vec, compare_access_positions);
3740 while (i < access_count)
3744 access = VEC_index (access_p, access_vec, i);
3745 modification = access->write;
3746 if (access_precludes_ipa_sra_p (access))
3748 a1_alias_type = reference_alias_ptr_type (access->expr);
3750 /* Access is about to become group representative unless we find some
3751 nasty overlap which would preclude us from breaking this parameter
3755 while (j < access_count)
3757 struct access *ac2 = VEC_index (access_p, access_vec, j);
3758 if (ac2->offset != access->offset)
3760 /* All or nothing law for parameters. */
3761 if (access->offset + access->size > ac2->offset)
3766 else if (ac2->size != access->size)
3769 if (access_precludes_ipa_sra_p (ac2)
3770 || (ac2->type != access->type
3771 && (TREE_ADDRESSABLE (ac2->type)
3772 || TREE_ADDRESSABLE (access->type)))
3773 || (reference_alias_ptr_type (ac2->expr) != a1_alias_type))
3776 modification |= ac2->write;
3777 ac2->group_representative = access;
3778 ac2->next_sibling = access->next_sibling;
3779 access->next_sibling = ac2;
3784 access->grp_maybe_modified = modification;
3787 *prev_acc_ptr = access;
3788 prev_acc_ptr = &access->next_grp;
3789 total_size += access->size;
3793 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3794 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3796 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3797 if (total_size >= agg_size)
3800 gcc_assert (group_count > 0);
3804 /* Decide whether parameters with representative accesses given by REPR should
3805 be reduced into components. */
3808 decide_one_param_reduction (struct access *repr)
3810 int total_size, cur_parm_size, agg_size, new_param_count, parm_size_limit;
3815 cur_parm_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3816 gcc_assert (cur_parm_size > 0);
3818 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3821 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3826 agg_size = cur_parm_size;
3832 fprintf (dump_file, "Evaluating PARAM group sizes for ");
3833 print_generic_expr (dump_file, parm, 0);
3834 fprintf (dump_file, " (UID: %u): \n", DECL_UID (parm));
3835 for (acc = repr; acc; acc = acc->next_grp)
3836 dump_access (dump_file, acc, true);
3840 new_param_count = 0;
3842 for (; repr; repr = repr->next_grp)
3844 gcc_assert (parm == repr->base);
3846 /* Taking the address of a non-addressable field is verboten. */
3847 if (by_ref && repr->non_addressable)
3850 if (!by_ref || (!repr->grp_maybe_modified
3851 && !repr->grp_not_necessarilly_dereferenced))
3852 total_size += repr->size;
3854 total_size += cur_parm_size;
3859 gcc_assert (new_param_count > 0);
3861 if (optimize_function_for_size_p (cfun))
3862 parm_size_limit = cur_parm_size;
3864 parm_size_limit = (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR)
3867 if (total_size < agg_size
3868 && total_size <= parm_size_limit)
3871 fprintf (dump_file, " ....will be split into %i components\n",
3873 return new_param_count;
3879 /* The order of the following enums is important, we need to do extra work for
3880 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
3881 enum ipa_splicing_result { NO_GOOD_ACCESS, UNUSED_PARAMS, BY_VAL_ACCESSES,
3882 MODIF_BY_REF_ACCESSES, UNMODIF_BY_REF_ACCESSES };
3884 /* Identify representatives of all accesses to all candidate parameters for
3885 IPA-SRA. Return result based on what representatives have been found. */
3887 static enum ipa_splicing_result
3888 splice_all_param_accesses (VEC (access_p, heap) **representatives)
3890 enum ipa_splicing_result result = NO_GOOD_ACCESS;
3892 struct access *repr;
3894 *representatives = VEC_alloc (access_p, heap, func_param_count);
3896 for (parm = DECL_ARGUMENTS (current_function_decl);
3898 parm = DECL_CHAIN (parm))
3900 if (is_unused_scalar_param (parm))
3902 VEC_quick_push (access_p, *representatives,
3903 &no_accesses_representant);
3904 if (result == NO_GOOD_ACCESS)
3905 result = UNUSED_PARAMS;
3907 else if (POINTER_TYPE_P (TREE_TYPE (parm))
3908 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm)))
3909 && bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3911 repr = unmodified_by_ref_scalar_representative (parm);
3912 VEC_quick_push (access_p, *representatives, repr);
3914 result = UNMODIF_BY_REF_ACCESSES;
3916 else if (bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3918 bool ro_grp = false;
3919 repr = splice_param_accesses (parm, &ro_grp);
3920 VEC_quick_push (access_p, *representatives, repr);
3922 if (repr && !no_accesses_p (repr))
3924 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3927 result = UNMODIF_BY_REF_ACCESSES;
3928 else if (result < MODIF_BY_REF_ACCESSES)
3929 result = MODIF_BY_REF_ACCESSES;
3931 else if (result < BY_VAL_ACCESSES)
3932 result = BY_VAL_ACCESSES;
3934 else if (no_accesses_p (repr) && (result == NO_GOOD_ACCESS))
3935 result = UNUSED_PARAMS;
3938 VEC_quick_push (access_p, *representatives, NULL);
3941 if (result == NO_GOOD_ACCESS)
3943 VEC_free (access_p, heap, *representatives);
3944 *representatives = NULL;
3945 return NO_GOOD_ACCESS;
3951 /* Return the index of BASE in PARMS. Abort if it is not found. */
3954 get_param_index (tree base, VEC(tree, heap) *parms)
3958 len = VEC_length (tree, parms);
3959 for (i = 0; i < len; i++)
3960 if (VEC_index (tree, parms, i) == base)
3965 /* Convert the decisions made at the representative level into compact
3966 parameter adjustments. REPRESENTATIVES are pointers to first
3967 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
3968 final number of adjustments. */
3970 static ipa_parm_adjustment_vec
3971 turn_representatives_into_adjustments (VEC (access_p, heap) *representatives,
3972 int adjustments_count)
3974 VEC (tree, heap) *parms;
3975 ipa_parm_adjustment_vec adjustments;
3979 gcc_assert (adjustments_count > 0);
3980 parms = ipa_get_vector_of_formal_parms (current_function_decl);
3981 adjustments = VEC_alloc (ipa_parm_adjustment_t, heap, adjustments_count);
3982 parm = DECL_ARGUMENTS (current_function_decl);
3983 for (i = 0; i < func_param_count; i++, parm = DECL_CHAIN (parm))
3985 struct access *repr = VEC_index (access_p, representatives, i);
3987 if (!repr || no_accesses_p (repr))
3989 struct ipa_parm_adjustment *adj;
3991 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
3992 memset (adj, 0, sizeof (*adj));
3993 adj->base_index = get_param_index (parm, parms);
3996 adj->copy_param = 1;
3998 adj->remove_param = 1;
4002 struct ipa_parm_adjustment *adj;
4003 int index = get_param_index (parm, parms);
4005 for (; repr; repr = repr->next_grp)
4007 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
4008 memset (adj, 0, sizeof (*adj));
4009 gcc_assert (repr->base == parm);
4010 adj->base_index = index;
4011 adj->base = repr->base;
4012 adj->type = repr->type;
4013 adj->alias_ptr_type = reference_alias_ptr_type (repr->expr);
4014 adj->offset = repr->offset;
4015 adj->by_ref = (POINTER_TYPE_P (TREE_TYPE (repr->base))
4016 && (repr->grp_maybe_modified
4017 || repr->grp_not_necessarilly_dereferenced));
4022 VEC_free (tree, heap, parms);
4026 /* Analyze the collected accesses and produce a plan what to do with the
4027 parameters in the form of adjustments, NULL meaning nothing. */
4029 static ipa_parm_adjustment_vec
4030 analyze_all_param_acesses (void)
4032 enum ipa_splicing_result repr_state;
4033 bool proceed = false;
4034 int i, adjustments_count = 0;
4035 VEC (access_p, heap) *representatives;
4036 ipa_parm_adjustment_vec adjustments;
4038 repr_state = splice_all_param_accesses (&representatives);
4039 if (repr_state == NO_GOOD_ACCESS)
4042 /* If there are any parameters passed by reference which are not modified
4043 directly, we need to check whether they can be modified indirectly. */
4044 if (repr_state == UNMODIF_BY_REF_ACCESSES)
4046 analyze_caller_dereference_legality (representatives);
4047 analyze_modified_params (representatives);
4050 for (i = 0; i < func_param_count; i++)
4052 struct access *repr = VEC_index (access_p, representatives, i);
4054 if (repr && !no_accesses_p (repr))
4056 if (repr->grp_scalar_ptr)
4058 adjustments_count++;
4059 if (repr->grp_not_necessarilly_dereferenced
4060 || repr->grp_maybe_modified)
4061 VEC_replace (access_p, representatives, i, NULL);
4065 sra_stats.scalar_by_ref_to_by_val++;
4070 int new_components = decide_one_param_reduction (repr);
4072 if (new_components == 0)
4074 VEC_replace (access_p, representatives, i, NULL);
4075 adjustments_count++;
4079 adjustments_count += new_components;
4080 sra_stats.aggregate_params_reduced++;
4081 sra_stats.param_reductions_created += new_components;
4088 if (no_accesses_p (repr))
4091 sra_stats.deleted_unused_parameters++;
4093 adjustments_count++;
4097 if (!proceed && dump_file)
4098 fprintf (dump_file, "NOT proceeding to change params.\n");
4101 adjustments = turn_representatives_into_adjustments (representatives,
4106 VEC_free (access_p, heap, representatives);
4110 /* If a parameter replacement identified by ADJ does not yet exist in the form
4111 of declaration, create it and record it, otherwise return the previously
4115 get_replaced_param_substitute (struct ipa_parm_adjustment *adj)
4118 if (!adj->new_ssa_base)
4120 char *pretty_name = make_fancy_name (adj->base);
4122 repl = create_tmp_reg (TREE_TYPE (adj->base), "ISR");
4123 DECL_NAME (repl) = get_identifier (pretty_name);
4124 obstack_free (&name_obstack, pretty_name);
4126 add_referenced_var (repl);
4127 adj->new_ssa_base = repl;
4130 repl = adj->new_ssa_base;
4134 /* Find the first adjustment for a particular parameter BASE in a vector of
4135 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
4138 static struct ipa_parm_adjustment *
4139 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments, tree base)
4143 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4144 for (i = 0; i < len; i++)
4146 struct ipa_parm_adjustment *adj;
4148 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4149 if (!adj->copy_param && adj->base == base)
4156 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
4157 removed because its value is not used, replace the SSA_NAME with a one
4158 relating to a created VAR_DECL together all of its uses and return true.
4159 ADJUSTMENTS is a pointer to an adjustments vector. */
4162 replace_removed_params_ssa_names (gimple stmt,
4163 ipa_parm_adjustment_vec adjustments)
4165 struct ipa_parm_adjustment *adj;
4166 tree lhs, decl, repl, name;
4168 if (gimple_code (stmt) == GIMPLE_PHI)
4169 lhs = gimple_phi_result (stmt);
4170 else if (is_gimple_assign (stmt))
4171 lhs = gimple_assign_lhs (stmt);
4172 else if (is_gimple_call (stmt))
4173 lhs = gimple_call_lhs (stmt);
4177 if (TREE_CODE (lhs) != SSA_NAME)
4179 decl = SSA_NAME_VAR (lhs);
4180 if (TREE_CODE (decl) != PARM_DECL)
4183 adj = get_adjustment_for_base (adjustments, decl);
4187 repl = get_replaced_param_substitute (adj);
4188 name = make_ssa_name (repl, stmt);
4192 fprintf (dump_file, "replacing an SSA name of a removed param ");
4193 print_generic_expr (dump_file, lhs, 0);
4194 fprintf (dump_file, " with ");
4195 print_generic_expr (dump_file, name, 0);
4196 fprintf (dump_file, "\n");
4199 if (is_gimple_assign (stmt))
4200 gimple_assign_set_lhs (stmt, name);
4201 else if (is_gimple_call (stmt))
4202 gimple_call_set_lhs (stmt, name);
4204 gimple_phi_set_result (stmt, name);
4206 replace_uses_by (lhs, name);
4207 release_ssa_name (lhs);
4211 /* If the expression *EXPR should be replaced by a reduction of a parameter, do
4212 so. ADJUSTMENTS is a pointer to a vector of adjustments. CONVERT
4213 specifies whether the function should care about type incompatibility the
4214 current and new expressions. If it is false, the function will leave
4215 incompatibility issues to the caller. Return true iff the expression
4219 sra_ipa_modify_expr (tree *expr, bool convert,
4220 ipa_parm_adjustment_vec adjustments)
4223 struct ipa_parm_adjustment *adj, *cand = NULL;
4224 HOST_WIDE_INT offset, size, max_size;
4227 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4229 if (TREE_CODE (*expr) == BIT_FIELD_REF
4230 || TREE_CODE (*expr) == IMAGPART_EXPR
4231 || TREE_CODE (*expr) == REALPART_EXPR)
4233 expr = &TREE_OPERAND (*expr, 0);
4237 base = get_ref_base_and_extent (*expr, &offset, &size, &max_size);
4238 if (!base || size == -1 || max_size == -1)
4241 if (TREE_CODE (base) == MEM_REF)
4243 offset += mem_ref_offset (base).low * BITS_PER_UNIT;
4244 base = TREE_OPERAND (base, 0);
4247 base = get_ssa_base_param (base);
4248 if (!base || TREE_CODE (base) != PARM_DECL)
4251 for (i = 0; i < len; i++)
4253 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4255 if (adj->base == base &&
4256 (adj->offset == offset || adj->remove_param))
4262 if (!cand || cand->copy_param || cand->remove_param)
4266 src = build_simple_mem_ref (cand->reduction);
4268 src = cand->reduction;
4270 if (dump_file && (dump_flags & TDF_DETAILS))
4272 fprintf (dump_file, "About to replace expr ");
4273 print_generic_expr (dump_file, *expr, 0);
4274 fprintf (dump_file, " with ");
4275 print_generic_expr (dump_file, src, 0);
4276 fprintf (dump_file, "\n");
4279 if (convert && !useless_type_conversion_p (TREE_TYPE (*expr), cand->type))
4281 tree vce = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (*expr), src);
4289 /* If the statement pointed to by STMT_PTR contains any expressions that need
4290 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4291 potential type incompatibilities (GSI is used to accommodate conversion
4292 statements and must point to the statement). Return true iff the statement
4296 sra_ipa_modify_assign (gimple *stmt_ptr, gimple_stmt_iterator *gsi,
4297 ipa_parm_adjustment_vec adjustments)
4299 gimple stmt = *stmt_ptr;
4300 tree *lhs_p, *rhs_p;
4303 if (!gimple_assign_single_p (stmt))
4306 rhs_p = gimple_assign_rhs1_ptr (stmt);
4307 lhs_p = gimple_assign_lhs_ptr (stmt);
4309 any = sra_ipa_modify_expr (rhs_p, false, adjustments);
4310 any |= sra_ipa_modify_expr (lhs_p, false, adjustments);
4313 tree new_rhs = NULL_TREE;
4315 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p), TREE_TYPE (*rhs_p)))
4317 if (TREE_CODE (*rhs_p) == CONSTRUCTOR)
4319 /* V_C_Es of constructors can cause trouble (PR 42714). */
4320 if (is_gimple_reg_type (TREE_TYPE (*lhs_p)))
4321 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
4323 *rhs_p = build_constructor (TREE_TYPE (*lhs_p), 0);
4326 new_rhs = fold_build1_loc (gimple_location (stmt),
4327 VIEW_CONVERT_EXPR, TREE_TYPE (*lhs_p),
4330 else if (REFERENCE_CLASS_P (*rhs_p)
4331 && is_gimple_reg_type (TREE_TYPE (*lhs_p))
4332 && !is_gimple_reg (*lhs_p))
4333 /* This can happen when an assignment in between two single field
4334 structures is turned into an assignment in between two pointers to
4335 scalars (PR 42237). */
4340 tree tmp = force_gimple_operand_gsi (gsi, new_rhs, true, NULL_TREE,
4341 true, GSI_SAME_STMT);
4343 gimple_assign_set_rhs_from_tree (gsi, tmp);
4352 /* Traverse the function body and all modifications as described in
4353 ADJUSTMENTS. Return true iff the CFG has been changed. */
4356 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments)
4358 bool cfg_changed = false;
4363 gimple_stmt_iterator gsi;
4365 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4366 replace_removed_params_ssa_names (gsi_stmt (gsi), adjustments);
4368 gsi = gsi_start_bb (bb);
4369 while (!gsi_end_p (gsi))
4371 gimple stmt = gsi_stmt (gsi);
4372 bool modified = false;
4376 switch (gimple_code (stmt))
4379 t = gimple_return_retval_ptr (stmt);
4380 if (*t != NULL_TREE)
4381 modified |= sra_ipa_modify_expr (t, true, adjustments);
4385 modified |= sra_ipa_modify_assign (&stmt, &gsi, adjustments);
4386 modified |= replace_removed_params_ssa_names (stmt, adjustments);
4390 /* Operands must be processed before the lhs. */
4391 for (i = 0; i < gimple_call_num_args (stmt); i++)
4393 t = gimple_call_arg_ptr (stmt, i);
4394 modified |= sra_ipa_modify_expr (t, true, adjustments);
4397 if (gimple_call_lhs (stmt))
4399 t = gimple_call_lhs_ptr (stmt);
4400 modified |= sra_ipa_modify_expr (t, false, adjustments);
4401 modified |= replace_removed_params_ssa_names (stmt,
4407 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
4409 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
4410 modified |= sra_ipa_modify_expr (t, true, adjustments);
4412 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
4414 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
4415 modified |= sra_ipa_modify_expr (t, false, adjustments);
4426 if (maybe_clean_eh_stmt (stmt)
4427 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
4437 /* Call gimple_debug_bind_reset_value on all debug statements describing
4438 gimple register parameters that are being removed or replaced. */
4441 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments)
4444 gimple_stmt_iterator *gsip = NULL, gsi;
4446 if (MAY_HAVE_DEBUG_STMTS && single_succ_p (ENTRY_BLOCK_PTR))
4448 gsi = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR));
4451 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4452 for (i = 0; i < len; i++)
4454 struct ipa_parm_adjustment *adj;
4455 imm_use_iterator ui;
4456 gimple stmt, def_temp;
4457 tree name, vexpr, copy = NULL_TREE;
4458 use_operand_p use_p;
4460 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4461 if (adj->copy_param || !is_gimple_reg (adj->base))
4463 name = gimple_default_def (cfun, adj->base);
4466 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
4468 /* All other users must have been removed by
4469 ipa_sra_modify_function_body. */
4470 gcc_assert (is_gimple_debug (stmt));
4471 if (vexpr == NULL && gsip != NULL)
4473 gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
4474 vexpr = make_node (DEBUG_EXPR_DECL);
4475 def_temp = gimple_build_debug_source_bind (vexpr, adj->base,
4477 DECL_ARTIFICIAL (vexpr) = 1;
4478 TREE_TYPE (vexpr) = TREE_TYPE (name);
4479 DECL_MODE (vexpr) = DECL_MODE (adj->base);
4480 gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
4484 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
4485 SET_USE (use_p, vexpr);
4488 gimple_debug_bind_reset_value (stmt);
4491 /* Create a VAR_DECL for debug info purposes. */
4492 if (!DECL_IGNORED_P (adj->base))
4494 copy = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
4495 VAR_DECL, DECL_NAME (adj->base),
4496 TREE_TYPE (adj->base));
4497 if (DECL_PT_UID_SET_P (adj->base))
4498 SET_DECL_PT_UID (copy, DECL_PT_UID (adj->base));
4499 TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (adj->base);
4500 TREE_READONLY (copy) = TREE_READONLY (adj->base);
4501 TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (adj->base);
4502 DECL_GIMPLE_REG_P (copy) = DECL_GIMPLE_REG_P (adj->base);
4503 DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (adj->base);
4504 DECL_IGNORED_P (copy) = DECL_IGNORED_P (adj->base);
4505 DECL_ABSTRACT_ORIGIN (copy) = DECL_ORIGIN (adj->base);
4506 DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
4507 SET_DECL_RTL (copy, 0);
4508 TREE_USED (copy) = 1;
4509 DECL_CONTEXT (copy) = current_function_decl;
4510 add_referenced_var (copy);
4511 add_local_decl (cfun, copy);
4513 BLOCK_VARS (DECL_INITIAL (current_function_decl));
4514 BLOCK_VARS (DECL_INITIAL (current_function_decl)) = copy;
4516 if (gsip != NULL && copy && target_for_debug_bind (adj->base))
4518 gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
4520 def_temp = gimple_build_debug_bind (copy, vexpr, NULL);
4522 def_temp = gimple_build_debug_source_bind (copy, adj->base,
4524 gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
4529 /* Return false iff all callers have at least as many actual arguments as there
4530 are formal parameters in the current function. */
4533 not_all_callers_have_enough_arguments_p (struct cgraph_node *node,
4534 void *data ATTRIBUTE_UNUSED)
4536 struct cgraph_edge *cs;
4537 for (cs = node->callers; cs; cs = cs->next_caller)
4538 if (!callsite_has_enough_arguments_p (cs->call_stmt))
4544 /* Convert all callers of NODE. */
4547 convert_callers_for_node (struct cgraph_node *node,
4550 ipa_parm_adjustment_vec adjustments = (ipa_parm_adjustment_vec)data;
4551 bitmap recomputed_callers = BITMAP_ALLOC (NULL);
4552 struct cgraph_edge *cs;
4554 for (cs = node->callers; cs; cs = cs->next_caller)
4556 current_function_decl = cs->caller->decl;
4557 push_cfun (DECL_STRUCT_FUNCTION (cs->caller->decl));
4560 fprintf (dump_file, "Adjusting call (%i -> %i) %s -> %s\n",
4561 cs->caller->uid, cs->callee->uid,
4562 cgraph_node_name (cs->caller),
4563 cgraph_node_name (cs->callee));
4565 ipa_modify_call_arguments (cs, cs->call_stmt, adjustments);
4570 for (cs = node->callers; cs; cs = cs->next_caller)
4571 if (bitmap_set_bit (recomputed_callers, cs->caller->uid)
4572 && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (cs->caller->decl)))
4573 compute_inline_parameters (cs->caller, true);
4574 BITMAP_FREE (recomputed_callers);
4579 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4582 convert_callers (struct cgraph_node *node, tree old_decl,
4583 ipa_parm_adjustment_vec adjustments)
4585 tree old_cur_fndecl = current_function_decl;
4586 basic_block this_block;
4588 cgraph_for_node_and_aliases (node, convert_callers_for_node,
4589 adjustments, false);
4591 current_function_decl = old_cur_fndecl;
4593 if (!encountered_recursive_call)
4596 FOR_EACH_BB (this_block)
4598 gimple_stmt_iterator gsi;
4600 for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
4602 gimple stmt = gsi_stmt (gsi);
4604 if (gimple_code (stmt) != GIMPLE_CALL)
4606 call_fndecl = gimple_call_fndecl (stmt);
4607 if (call_fndecl == old_decl)
4610 fprintf (dump_file, "Adjusting recursive call");
4611 gimple_call_set_fndecl (stmt, node->decl);
4612 ipa_modify_call_arguments (NULL, stmt, adjustments);
4620 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4621 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4624 modify_function (struct cgraph_node *node, ipa_parm_adjustment_vec adjustments)
4626 struct cgraph_node *new_node;
4628 VEC (cgraph_edge_p, heap) * redirect_callers = collect_callers_of_node (node);
4630 rebuild_cgraph_edges ();
4631 free_dominance_info (CDI_DOMINATORS);
4633 current_function_decl = NULL_TREE;
4635 new_node = cgraph_function_versioning (node, redirect_callers, NULL, NULL,
4636 NULL, NULL, "isra");
4637 current_function_decl = new_node->decl;
4638 push_cfun (DECL_STRUCT_FUNCTION (new_node->decl));
4640 ipa_modify_formal_parameters (current_function_decl, adjustments, "ISRA");
4641 cfg_changed = ipa_sra_modify_function_body (adjustments);
4642 sra_ipa_reset_debug_stmts (adjustments);
4643 convert_callers (new_node, node->decl, adjustments);
4644 cgraph_make_node_local (new_node);
4648 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4649 attributes, return true otherwise. NODE is the cgraph node of the current
4653 ipa_sra_preliminary_function_checks (struct cgraph_node *node)
4655 if (!cgraph_node_can_be_local_p (node))
4658 fprintf (dump_file, "Function not local to this compilation unit.\n");
4662 if (!node->local.can_change_signature)
4665 fprintf (dump_file, "Function can not change signature.\n");
4669 if (!tree_versionable_function_p (node->decl))
4672 fprintf (dump_file, "Function is not versionable.\n");
4676 if (DECL_VIRTUAL_P (current_function_decl))
4679 fprintf (dump_file, "Function is a virtual method.\n");
4683 if ((DECL_COMDAT (node->decl) || DECL_EXTERNAL (node->decl))
4684 && inline_summary(node)->size >= MAX_INLINE_INSNS_AUTO)
4687 fprintf (dump_file, "Function too big to be made truly local.\n");
4695 "Function has no callers in this compilation unit.\n");
4702 fprintf (dump_file, "Function uses stdarg. \n");
4706 if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl)))
4712 /* Perform early interprocedural SRA. */
4715 ipa_early_sra (void)
4717 struct cgraph_node *node = cgraph_get_node (current_function_decl);
4718 ipa_parm_adjustment_vec adjustments;
4721 if (!ipa_sra_preliminary_function_checks (node))
4725 sra_mode = SRA_MODE_EARLY_IPA;
4727 if (!find_param_candidates ())
4730 fprintf (dump_file, "Function has no IPA-SRA candidates.\n");
4734 if (cgraph_for_node_and_aliases (node, not_all_callers_have_enough_arguments_p,
4738 fprintf (dump_file, "There are callers with insufficient number of "
4743 bb_dereferences = XCNEWVEC (HOST_WIDE_INT,
4745 * last_basic_block_for_function (cfun));
4746 final_bbs = BITMAP_ALLOC (NULL);
4749 if (encountered_apply_args)
4752 fprintf (dump_file, "Function calls __builtin_apply_args().\n");
4756 if (encountered_unchangable_recursive_call)
4759 fprintf (dump_file, "Function calls itself with insufficient "
4760 "number of arguments.\n");
4764 adjustments = analyze_all_param_acesses ();
4768 ipa_dump_param_adjustments (dump_file, adjustments, current_function_decl);
4770 if (modify_function (node, adjustments))
4771 ret = TODO_update_ssa | TODO_cleanup_cfg;
4773 ret = TODO_update_ssa;
4774 VEC_free (ipa_parm_adjustment_t, heap, adjustments);
4776 statistics_counter_event (cfun, "Unused parameters deleted",
4777 sra_stats.deleted_unused_parameters);
4778 statistics_counter_event (cfun, "Scalar parameters converted to by-value",
4779 sra_stats.scalar_by_ref_to_by_val);
4780 statistics_counter_event (cfun, "Aggregate parameters broken up",
4781 sra_stats.aggregate_params_reduced);
4782 statistics_counter_event (cfun, "Aggregate parameter components created",
4783 sra_stats.param_reductions_created);
4786 BITMAP_FREE (final_bbs);
4787 free (bb_dereferences);
4789 sra_deinitialize ();
4793 /* Return if early ipa sra shall be performed. */
4795 ipa_early_sra_gate (void)
4797 return flag_ipa_sra && dbg_cnt (eipa_sra);
4800 struct gimple_opt_pass pass_early_ipa_sra =
4804 "eipa_sra", /* name */
4805 ipa_early_sra_gate, /* gate */
4806 ipa_early_sra, /* execute */
4809 0, /* static_pass_number */
4810 TV_IPA_SRA, /* tv_id */
4811 0, /* properties_required */
4812 0, /* properties_provided */
4813 0, /* properties_destroyed */
4814 0, /* todo_flags_start */
4815 TODO_dump_cgraph /* todo_flags_finish */