1 /* Scalar Replacement of Aggregates (SRA) converts some structure
2 references into scalar references, exposing them to the scalar
4 Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
5 Contributed by Martin Jambor <mjambor@suse.cz>
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* This file implements Scalar Reduction of Aggregates (SRA). SRA is run
24 twice, once in the early stages of compilation (early SRA) and once in the
25 late stages (late SRA). The aim of both is to turn references to scalar
26 parts of aggregates into uses of independent scalar variables.
28 The two passes are nearly identical, the only difference is that early SRA
29 does not scalarize unions which are used as the result in a GIMPLE_RETURN
30 statement because together with inlining this can lead to weird type
33 Both passes operate in four stages:
35 1. The declarations that have properties which make them candidates for
36 scalarization are identified in function find_var_candidates(). The
37 candidates are stored in candidate_bitmap.
39 2. The function body is scanned. In the process, declarations which are
40 used in a manner that prevent their scalarization are removed from the
41 candidate bitmap. More importantly, for every access into an aggregate,
42 an access structure (struct access) is created by create_access() and
43 stored in a vector associated with the aggregate. Among other
44 information, the aggregate declaration, the offset and size of the access
45 and its type are stored in the structure.
47 On a related note, assign_link structures are created for every assign
48 statement between candidate aggregates and attached to the related
51 3. The vectors of accesses are analyzed. They are first sorted according to
52 their offset and size and then scanned for partially overlapping accesses
53 (i.e. those which overlap but one is not entirely within another). Such
54 an access disqualifies the whole aggregate from being scalarized.
56 If there is no such inhibiting overlap, a representative access structure
57 is chosen for every unique combination of offset and size. Afterwards,
58 the pass builds a set of trees from these structures, in which children
59 of an access are within their parent (in terms of offset and size).
61 Then accesses are propagated whenever possible (i.e. in cases when it
62 does not create a partially overlapping access) across assign_links from
63 the right hand side to the left hand side.
65 Then the set of trees for each declaration is traversed again and those
66 accesses which should be replaced by a scalar are identified.
68 4. The function is traversed again, and for every reference into an
69 aggregate that has some component which is about to be scalarized,
70 statements are amended and new statements are created as necessary.
71 Finally, if a parameter got scalarized, the scalar replacements are
72 initialized with values from respective parameter aggregates. */
76 #include "coretypes.h"
77 #include "alloc-pool.h"
82 #include "tree-flow.h"
84 #include "tree-pretty-print.h"
85 #include "statistics.h"
86 #include "tree-dump.h"
92 #include "tree-inline.h"
93 #include "gimple-pretty-print.h"
95 /* Enumeration of all aggregate reductions we can do. */
96 enum sra_mode { SRA_MODE_EARLY_IPA, /* early call regularization */
97 SRA_MODE_EARLY_INTRA, /* early intraprocedural SRA */
98 SRA_MODE_INTRA }; /* late intraprocedural SRA */
100 /* Global variable describing which aggregate reduction we are performing at
102 static enum sra_mode sra_mode;
106 /* ACCESS represents each access to an aggregate variable (as a whole or a
107 part). It can also represent a group of accesses that refer to exactly the
108 same fragment of an aggregate (i.e. those that have exactly the same offset
109 and size). Such representatives for a single aggregate, once determined,
110 are linked in a linked list and have the group fields set.
112 Moreover, when doing intraprocedural SRA, a tree is built from those
113 representatives (by the means of first_child and next_sibling pointers), in
114 which all items in a subtree are "within" the root, i.e. their offset is
115 greater or equal to offset of the root and offset+size is smaller or equal
116 to offset+size of the root. Children of an access are sorted by offset.
118 Note that accesses to parts of vector and complex number types always
119 represented by an access to the whole complex number or a vector. It is a
120 duty of the modifying functions to replace them appropriately. */
124 /* Values returned by `get_ref_base_and_extent' for each component reference
125 If EXPR isn't a component reference just set `BASE = EXPR', `OFFSET = 0',
126 `SIZE = TREE_SIZE (TREE_TYPE (expr))'. */
127 HOST_WIDE_INT offset;
131 /* Expression. It is context dependent so do not use it to create new
132 expressions to access the original aggregate. See PR 42154 for a
138 /* The statement this access belongs to. */
141 /* Next group representative for this aggregate. */
142 struct access *next_grp;
144 /* Pointer to the group representative. Pointer to itself if the struct is
145 the representative. */
146 struct access *group_representative;
148 /* If this access has any children (in terms of the definition above), this
149 points to the first one. */
150 struct access *first_child;
152 /* In intraprocedural SRA, pointer to the next sibling in the access tree as
153 described above. In IPA-SRA this is a pointer to the next access
154 belonging to the same group (having the same representative). */
155 struct access *next_sibling;
157 /* Pointers to the first and last element in the linked list of assign
159 struct assign_link *first_link, *last_link;
161 /* Pointer to the next access in the work queue. */
162 struct access *next_queued;
164 /* Replacement variable for this access "region." Never to be accessed
165 directly, always only by the means of get_access_replacement() and only
166 when grp_to_be_replaced flag is set. */
167 tree replacement_decl;
169 /* Is this particular access write access? */
172 /* Is this access an artificial one created to scalarize some record
174 unsigned total_scalarization : 1;
176 /* Is this access an access to a non-addressable field? */
177 unsigned non_addressable : 1;
179 /* Is this access currently in the work queue? */
180 unsigned grp_queued : 1;
182 /* Does this group contain a write access? This flag is propagated down the
184 unsigned grp_write : 1;
186 /* Does this group contain a read access? This flag is propagated down the
188 unsigned grp_read : 1;
190 /* Does this group contain a read access that comes from an assignment
191 statement? This flag is propagated down the access tree. */
192 unsigned grp_assignment_read : 1;
194 /* Does this group contain a write access that comes from an assignment
195 statement? This flag is propagated down the access tree. */
196 unsigned grp_assignment_write : 1;
198 /* Does this group contain a read access through a scalar type? This flag is
199 not propagated in the access tree in any direction. */
200 unsigned grp_scalar_read : 1;
202 /* Does this group contain a write access through a scalar type? This flag
203 is not propagated in the access tree in any direction. */
204 unsigned grp_scalar_write : 1;
206 /* Other passes of the analysis use this bit to make function
207 analyze_access_subtree create scalar replacements for this group if
209 unsigned grp_hint : 1;
211 /* Is the subtree rooted in this access fully covered by scalar
213 unsigned grp_covered : 1;
215 /* If set to true, this access and all below it in an access tree must not be
217 unsigned grp_unscalarizable_region : 1;
219 /* Whether data have been written to parts of the aggregate covered by this
220 access which is not to be scalarized. This flag is propagated up in the
222 unsigned grp_unscalarized_data : 1;
224 /* Does this access and/or group contain a write access through a
226 unsigned grp_partial_lhs : 1;
228 /* Set when a scalar replacement should be created for this variable. We do
229 the decision and creation at different places because create_tmp_var
230 cannot be called from within FOR_EACH_REFERENCED_VAR. */
231 unsigned grp_to_be_replaced : 1;
233 /* Should TREE_NO_WARNING of a replacement be set? */
234 unsigned grp_no_warning : 1;
236 /* Is it possible that the group refers to data which might be (directly or
237 otherwise) modified? */
238 unsigned grp_maybe_modified : 1;
240 /* Set when this is a representative of a pointer to scalar (i.e. by
241 reference) parameter which we consider for turning into a plain scalar
242 (i.e. a by value parameter). */
243 unsigned grp_scalar_ptr : 1;
245 /* Set when we discover that this pointer is not safe to dereference in the
247 unsigned grp_not_necessarilly_dereferenced : 1;
250 typedef struct access *access_p;
252 DEF_VEC_P (access_p);
253 DEF_VEC_ALLOC_P (access_p, heap);
255 /* Alloc pool for allocating access structures. */
256 static alloc_pool access_pool;
258 /* A structure linking lhs and rhs accesses from an aggregate assignment. They
259 are used to propagate subaccesses from rhs to lhs as long as they don't
260 conflict with what is already there. */
263 struct access *lacc, *racc;
264 struct assign_link *next;
267 /* Alloc pool for allocating assign link structures. */
268 static alloc_pool link_pool;
270 /* Base (tree) -> Vector (VEC(access_p,heap) *) map. */
271 static struct pointer_map_t *base_access_vec;
273 /* Bitmap of candidates. */
274 static bitmap candidate_bitmap;
276 /* Bitmap of candidates which we should try to entirely scalarize away and
277 those which cannot be (because they are and need be used as a whole). */
278 static bitmap should_scalarize_away_bitmap, cannot_scalarize_away_bitmap;
280 /* Obstack for creation of fancy names. */
281 static struct obstack name_obstack;
283 /* Head of a linked list of accesses that need to have its subaccesses
284 propagated to their assignment counterparts. */
285 static struct access *work_queue_head;
287 /* Number of parameters of the analyzed function when doing early ipa SRA. */
288 static int func_param_count;
290 /* scan_function sets the following to true if it encounters a call to
291 __builtin_apply_args. */
292 static bool encountered_apply_args;
294 /* Set by scan_function when it finds a recursive call. */
295 static bool encountered_recursive_call;
297 /* Set by scan_function when it finds a recursive call with less actual
298 arguments than formal parameters.. */
299 static bool encountered_unchangable_recursive_call;
301 /* This is a table in which for each basic block and parameter there is a
302 distance (offset + size) in that parameter which is dereferenced and
303 accessed in that BB. */
304 static HOST_WIDE_INT *bb_dereferences;
305 /* Bitmap of BBs that can cause the function to "stop" progressing by
306 returning, throwing externally, looping infinitely or calling a function
307 which might abort etc.. */
308 static bitmap final_bbs;
310 /* Representative of no accesses at all. */
311 static struct access no_accesses_representant;
313 /* Predicate to test the special value. */
316 no_accesses_p (struct access *access)
318 return access == &no_accesses_representant;
321 /* Dump contents of ACCESS to file F in a human friendly way. If GRP is true,
322 representative fields are dumped, otherwise those which only describe the
323 individual access are. */
327 /* Number of processed aggregates is readily available in
328 analyze_all_variable_accesses and so is not stored here. */
330 /* Number of created scalar replacements. */
333 /* Number of times sra_modify_expr or sra_modify_assign themselves changed an
337 /* Number of statements created by generate_subtree_copies. */
340 /* Number of statements created by load_assign_lhs_subreplacements. */
343 /* Number of times sra_modify_assign has deleted a statement. */
346 /* Number of times sra_modify_assign has to deal with subaccesses of LHS and
347 RHS reparately due to type conversions or nonexistent matching
349 int separate_lhs_rhs_handling;
351 /* Number of parameters that were removed because they were unused. */
352 int deleted_unused_parameters;
354 /* Number of scalars passed as parameters by reference that have been
355 converted to be passed by value. */
356 int scalar_by_ref_to_by_val;
358 /* Number of aggregate parameters that were replaced by one or more of their
360 int aggregate_params_reduced;
362 /* Numbber of components created when splitting aggregate parameters. */
363 int param_reductions_created;
367 dump_access (FILE *f, struct access *access, bool grp)
369 fprintf (f, "access { ");
370 fprintf (f, "base = (%d)'", DECL_UID (access->base));
371 print_generic_expr (f, access->base, 0);
372 fprintf (f, "', offset = " HOST_WIDE_INT_PRINT_DEC, access->offset);
373 fprintf (f, ", size = " HOST_WIDE_INT_PRINT_DEC, access->size);
374 fprintf (f, ", expr = ");
375 print_generic_expr (f, access->expr, 0);
376 fprintf (f, ", type = ");
377 print_generic_expr (f, access->type, 0);
379 fprintf (f, ", total_scalarization = %d, grp_read = %d, grp_write = %d, "
380 "grp_assignment_read = %d, grp_assignment_write = %d, "
381 "grp_scalar_read = %d, grp_scalar_write = %d, "
382 "grp_hint = %d, grp_covered = %d, "
383 "grp_unscalarizable_region = %d, grp_unscalarized_data = %d, "
384 "grp_partial_lhs = %d, grp_to_be_replaced = %d, "
385 "grp_maybe_modified = %d, "
386 "grp_not_necessarilly_dereferenced = %d\n",
387 access->total_scalarization, access->grp_read, access->grp_write,
388 access->grp_assignment_read, access->grp_assignment_write,
389 access->grp_scalar_read, access->grp_scalar_write,
390 access->grp_hint, access->grp_covered,
391 access->grp_unscalarizable_region, access->grp_unscalarized_data,
392 access->grp_partial_lhs, access->grp_to_be_replaced,
393 access->grp_maybe_modified,
394 access->grp_not_necessarilly_dereferenced);
396 fprintf (f, ", write = %d, total_scalarization = %d, "
397 "grp_partial_lhs = %d\n",
398 access->write, access->total_scalarization,
399 access->grp_partial_lhs);
402 /* Dump a subtree rooted in ACCESS to file F, indent by LEVEL. */
405 dump_access_tree_1 (FILE *f, struct access *access, int level)
411 for (i = 0; i < level; i++)
412 fputs ("* ", dump_file);
414 dump_access (f, access, true);
416 if (access->first_child)
417 dump_access_tree_1 (f, access->first_child, level + 1);
419 access = access->next_sibling;
424 /* Dump all access trees for a variable, given the pointer to the first root in
428 dump_access_tree (FILE *f, struct access *access)
430 for (; access; access = access->next_grp)
431 dump_access_tree_1 (f, access, 0);
434 /* Return true iff ACC is non-NULL and has subaccesses. */
437 access_has_children_p (struct access *acc)
439 return acc && acc->first_child;
442 /* Return a vector of pointers to accesses for the variable given in BASE or
443 NULL if there is none. */
445 static VEC (access_p, heap) *
446 get_base_access_vector (tree base)
450 slot = pointer_map_contains (base_access_vec, base);
454 return *(VEC (access_p, heap) **) slot;
457 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
458 in ACCESS. Return NULL if it cannot be found. */
460 static struct access *
461 find_access_in_subtree (struct access *access, HOST_WIDE_INT offset,
464 while (access && (access->offset != offset || access->size != size))
466 struct access *child = access->first_child;
468 while (child && (child->offset + child->size <= offset))
469 child = child->next_sibling;
476 /* Return the first group representative for DECL or NULL if none exists. */
478 static struct access *
479 get_first_repr_for_decl (tree base)
481 VEC (access_p, heap) *access_vec;
483 access_vec = get_base_access_vector (base);
487 return VEC_index (access_p, access_vec, 0);
490 /* Find an access representative for the variable BASE and given OFFSET and
491 SIZE. Requires that access trees have already been built. Return NULL if
492 it cannot be found. */
494 static struct access *
495 get_var_base_offset_size_access (tree base, HOST_WIDE_INT offset,
498 struct access *access;
500 access = get_first_repr_for_decl (base);
501 while (access && (access->offset + access->size <= offset))
502 access = access->next_grp;
506 return find_access_in_subtree (access, offset, size);
509 /* Add LINK to the linked list of assign links of RACC. */
511 add_link_to_rhs (struct access *racc, struct assign_link *link)
513 gcc_assert (link->racc == racc);
515 if (!racc->first_link)
517 gcc_assert (!racc->last_link);
518 racc->first_link = link;
521 racc->last_link->next = link;
523 racc->last_link = link;
527 /* Move all link structures in their linked list in OLD_RACC to the linked list
530 relink_to_new_repr (struct access *new_racc, struct access *old_racc)
532 if (!old_racc->first_link)
534 gcc_assert (!old_racc->last_link);
538 if (new_racc->first_link)
540 gcc_assert (!new_racc->last_link->next);
541 gcc_assert (!old_racc->last_link || !old_racc->last_link->next);
543 new_racc->last_link->next = old_racc->first_link;
544 new_racc->last_link = old_racc->last_link;
548 gcc_assert (!new_racc->last_link);
550 new_racc->first_link = old_racc->first_link;
551 new_racc->last_link = old_racc->last_link;
553 old_racc->first_link = old_racc->last_link = NULL;
556 /* Add ACCESS to the work queue (which is actually a stack). */
559 add_access_to_work_queue (struct access *access)
561 if (!access->grp_queued)
563 gcc_assert (!access->next_queued);
564 access->next_queued = work_queue_head;
565 access->grp_queued = 1;
566 work_queue_head = access;
570 /* Pop an access from the work queue, and return it, assuming there is one. */
572 static struct access *
573 pop_access_from_work_queue (void)
575 struct access *access = work_queue_head;
577 work_queue_head = access->next_queued;
578 access->next_queued = NULL;
579 access->grp_queued = 0;
584 /* Allocate necessary structures. */
587 sra_initialize (void)
589 candidate_bitmap = BITMAP_ALLOC (NULL);
590 should_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
591 cannot_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
592 gcc_obstack_init (&name_obstack);
593 access_pool = create_alloc_pool ("SRA accesses", sizeof (struct access), 16);
594 link_pool = create_alloc_pool ("SRA links", sizeof (struct assign_link), 16);
595 base_access_vec = pointer_map_create ();
596 memset (&sra_stats, 0, sizeof (sra_stats));
597 encountered_apply_args = false;
598 encountered_recursive_call = false;
599 encountered_unchangable_recursive_call = false;
602 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
605 delete_base_accesses (const void *key ATTRIBUTE_UNUSED, void **value,
606 void *data ATTRIBUTE_UNUSED)
608 VEC (access_p, heap) *access_vec;
609 access_vec = (VEC (access_p, heap) *) *value;
610 VEC_free (access_p, heap, access_vec);
615 /* Deallocate all general structures. */
618 sra_deinitialize (void)
620 BITMAP_FREE (candidate_bitmap);
621 BITMAP_FREE (should_scalarize_away_bitmap);
622 BITMAP_FREE (cannot_scalarize_away_bitmap);
623 free_alloc_pool (access_pool);
624 free_alloc_pool (link_pool);
625 obstack_free (&name_obstack, NULL);
627 pointer_map_traverse (base_access_vec, delete_base_accesses, NULL);
628 pointer_map_destroy (base_access_vec);
631 /* Remove DECL from candidates for SRA and write REASON to the dump file if
634 disqualify_candidate (tree decl, const char *reason)
636 bitmap_clear_bit (candidate_bitmap, DECL_UID (decl));
638 if (dump_file && (dump_flags & TDF_DETAILS))
640 fprintf (dump_file, "! Disqualifying ");
641 print_generic_expr (dump_file, decl, 0);
642 fprintf (dump_file, " - %s\n", reason);
646 /* Return true iff the type contains a field or an element which does not allow
650 type_internals_preclude_sra_p (tree type)
655 switch (TREE_CODE (type))
659 case QUAL_UNION_TYPE:
660 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
661 if (TREE_CODE (fld) == FIELD_DECL)
663 tree ft = TREE_TYPE (fld);
665 if (TREE_THIS_VOLATILE (fld)
666 || !DECL_FIELD_OFFSET (fld) || !DECL_SIZE (fld)
667 || !host_integerp (DECL_FIELD_OFFSET (fld), 1)
668 || !host_integerp (DECL_SIZE (fld), 1)
669 || !host_integerp (bit_position (fld), 0)
670 || (AGGREGATE_TYPE_P (ft)
671 && int_bit_position (fld) % BITS_PER_UNIT != 0))
674 if (AGGREGATE_TYPE_P (ft)
675 && type_internals_preclude_sra_p (ft))
682 et = TREE_TYPE (type);
684 if (AGGREGATE_TYPE_P (et))
685 return type_internals_preclude_sra_p (et);
694 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
695 base variable if it is. Return T if it is not an SSA_NAME. */
698 get_ssa_base_param (tree t)
700 if (TREE_CODE (t) == SSA_NAME)
702 if (SSA_NAME_IS_DEFAULT_DEF (t))
703 return SSA_NAME_VAR (t);
710 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
711 belongs to, unless the BB has already been marked as a potentially
715 mark_parm_dereference (tree base, HOST_WIDE_INT dist, gimple stmt)
717 basic_block bb = gimple_bb (stmt);
718 int idx, parm_index = 0;
721 if (bitmap_bit_p (final_bbs, bb->index))
724 for (parm = DECL_ARGUMENTS (current_function_decl);
725 parm && parm != base;
726 parm = DECL_CHAIN (parm))
729 gcc_assert (parm_index < func_param_count);
731 idx = bb->index * func_param_count + parm_index;
732 if (bb_dereferences[idx] < dist)
733 bb_dereferences[idx] = dist;
736 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
737 the three fields. Also add it to the vector of accesses corresponding to
738 the base. Finally, return the new access. */
740 static struct access *
741 create_access_1 (tree base, HOST_WIDE_INT offset, HOST_WIDE_INT size)
743 VEC (access_p, heap) *vec;
744 struct access *access;
747 access = (struct access *) pool_alloc (access_pool);
748 memset (access, 0, sizeof (struct access));
750 access->offset = offset;
753 slot = pointer_map_contains (base_access_vec, base);
755 vec = (VEC (access_p, heap) *) *slot;
757 vec = VEC_alloc (access_p, heap, 32);
759 VEC_safe_push (access_p, heap, vec, access);
761 *((struct VEC (access_p,heap) **)
762 pointer_map_insert (base_access_vec, base)) = vec;
767 /* Create and insert access for EXPR. Return created access, or NULL if it is
770 static struct access *
771 create_access (tree expr, gimple stmt, bool write)
773 struct access *access;
774 HOST_WIDE_INT offset, size, max_size;
776 bool ptr, unscalarizable_region = false;
778 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
780 if (sra_mode == SRA_MODE_EARLY_IPA
781 && TREE_CODE (base) == MEM_REF)
783 base = get_ssa_base_param (TREE_OPERAND (base, 0));
791 if (!DECL_P (base) || !bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
794 if (sra_mode == SRA_MODE_EARLY_IPA)
796 if (size < 0 || size != max_size)
798 disqualify_candidate (base, "Encountered a variable sized access.");
801 if (TREE_CODE (expr) == COMPONENT_REF
802 && DECL_BIT_FIELD (TREE_OPERAND (expr, 1)))
804 disqualify_candidate (base, "Encountered a bit-field access.");
807 gcc_checking_assert ((offset % BITS_PER_UNIT) == 0);
810 mark_parm_dereference (base, offset + size, stmt);
814 if (size != max_size)
817 unscalarizable_region = true;
821 disqualify_candidate (base, "Encountered an unconstrained access.");
826 access = create_access_1 (base, offset, size);
828 access->type = TREE_TYPE (expr);
829 access->write = write;
830 access->grp_unscalarizable_region = unscalarizable_region;
833 if (TREE_CODE (expr) == COMPONENT_REF
834 && DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1)))
835 access->non_addressable = 1;
841 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
842 register types or (recursively) records with only these two kinds of fields.
843 It also returns false if any of these records contains a bit-field. */
846 type_consists_of_records_p (tree type)
850 if (TREE_CODE (type) != RECORD_TYPE)
853 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
854 if (TREE_CODE (fld) == FIELD_DECL)
856 tree ft = TREE_TYPE (fld);
858 if (DECL_BIT_FIELD (fld))
861 if (!is_gimple_reg_type (ft)
862 && !type_consists_of_records_p (ft))
869 /* Create total_scalarization accesses for all scalar type fields in DECL that
870 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
871 must be the top-most VAR_DECL representing the variable, OFFSET must be the
872 offset of DECL within BASE. REF must be the memory reference expression for
876 completely_scalarize_record (tree base, tree decl, HOST_WIDE_INT offset,
879 tree fld, decl_type = TREE_TYPE (decl);
881 for (fld = TYPE_FIELDS (decl_type); fld; fld = DECL_CHAIN (fld))
882 if (TREE_CODE (fld) == FIELD_DECL)
884 HOST_WIDE_INT pos = offset + int_bit_position (fld);
885 tree ft = TREE_TYPE (fld);
886 tree nref = build3 (COMPONENT_REF, TREE_TYPE (fld), ref, fld,
889 if (is_gimple_reg_type (ft))
891 struct access *access;
894 size = tree_low_cst (DECL_SIZE (fld), 1);
895 access = create_access_1 (base, pos, size);
898 access->total_scalarization = 1;
899 /* Accesses for intraprocedural SRA can have their stmt NULL. */
902 completely_scalarize_record (base, fld, pos, nref);
907 /* Search the given tree for a declaration by skipping handled components and
908 exclude it from the candidates. */
911 disqualify_base_of_expr (tree t, const char *reason)
913 t = get_base_address (t);
915 && sra_mode == SRA_MODE_EARLY_IPA
916 && TREE_CODE (t) == MEM_REF)
917 t = get_ssa_base_param (TREE_OPERAND (t, 0));
920 disqualify_candidate (t, reason);
923 /* Scan expression EXPR and create access structures for all accesses to
924 candidates for scalarization. Return the created access or NULL if none is
927 static struct access *
928 build_access_from_expr_1 (tree expr, gimple stmt, bool write)
930 struct access *ret = NULL;
933 if (TREE_CODE (expr) == BIT_FIELD_REF
934 || TREE_CODE (expr) == IMAGPART_EXPR
935 || TREE_CODE (expr) == REALPART_EXPR)
937 expr = TREE_OPERAND (expr, 0);
943 /* We need to dive through V_C_Es in order to get the size of its parameter
944 and not the result type. Ada produces such statements. We are also
945 capable of handling the topmost V_C_E but not any of those buried in other
946 handled components. */
947 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
948 expr = TREE_OPERAND (expr, 0);
950 if (contains_view_convert_expr_p (expr))
952 disqualify_base_of_expr (expr, "V_C_E under a different handled "
957 switch (TREE_CODE (expr))
960 if (TREE_CODE (TREE_OPERAND (expr, 0)) != ADDR_EXPR
961 && sra_mode != SRA_MODE_EARLY_IPA)
969 case ARRAY_RANGE_REF:
970 ret = create_access (expr, stmt, write);
977 if (write && partial_ref && ret)
978 ret->grp_partial_lhs = 1;
983 /* Scan expression EXPR and create access structures for all accesses to
984 candidates for scalarization. Return true if any access has been inserted.
985 STMT must be the statement from which the expression is taken, WRITE must be
986 true if the expression is a store and false otherwise. */
989 build_access_from_expr (tree expr, gimple stmt, bool write)
991 struct access *access;
993 access = build_access_from_expr_1 (expr, stmt, write);
996 /* This means the aggregate is accesses as a whole in a way other than an
997 assign statement and thus cannot be removed even if we had a scalar
998 replacement for everything. */
999 if (cannot_scalarize_away_bitmap)
1000 bitmap_set_bit (cannot_scalarize_away_bitmap, DECL_UID (access->base));
1006 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
1007 modes in which it matters, return true iff they have been disqualified. RHS
1008 may be NULL, in that case ignore it. If we scalarize an aggregate in
1009 intra-SRA we may need to add statements after each statement. This is not
1010 possible if a statement unconditionally has to end the basic block. */
1012 disqualify_ops_if_throwing_stmt (gimple stmt, tree lhs, tree rhs)
1014 if ((sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1015 && (stmt_can_throw_internal (stmt) || stmt_ends_bb_p (stmt)))
1017 disqualify_base_of_expr (lhs, "LHS of a throwing stmt.");
1019 disqualify_base_of_expr (rhs, "RHS of a throwing stmt.");
1025 /* Return true if EXP is a memory reference less aligned than ALIGN. This is
1026 invoked only on strict-alignment targets. */
1029 tree_non_aligned_mem_p (tree exp, unsigned int align)
1031 unsigned int exp_align;
1033 if (TREE_CODE (exp) == VIEW_CONVERT_EXPR)
1034 exp = TREE_OPERAND (exp, 0);
1036 if (TREE_CODE (exp) == SSA_NAME || is_gimple_min_invariant (exp))
1039 /* get_object_alignment will fall back to BITS_PER_UNIT if it cannot
1040 compute an explicit alignment. Pretend that dereferenced pointers
1041 are always aligned on strict-alignment targets. */
1042 exp_align = get_object_alignment (exp, BIGGEST_ALIGNMENT);
1043 if (TREE_CODE (exp) == MEM_REF || TREE_CODE (exp) == TARGET_MEM_REF)
1044 exp_align = MAX (TYPE_ALIGN (TREE_TYPE (exp)), exp_align);
1046 if (exp_align < align)
1052 /* Return true if EXP is a memory reference less aligned than what the access
1053 ACC would require. This is invoked only on strict-alignment targets. */
1056 tree_non_aligned_mem_for_access_p (tree exp, struct access *acc)
1058 unsigned int acc_align;
1060 /* The alignment of the access is that of its expression. However, it may
1061 have been artificially increased, e.g. by a local alignment promotion,
1062 so we cap it to the alignment of the type of the base, on the grounds
1063 that valid sub-accesses cannot be more aligned than that. */
1064 acc_align = get_object_alignment (acc->expr, BIGGEST_ALIGNMENT);
1065 if (acc->base && acc_align > TYPE_ALIGN (TREE_TYPE (acc->base)))
1066 acc_align = TYPE_ALIGN (TREE_TYPE (acc->base));
1068 return tree_non_aligned_mem_p (exp, acc_align);
1071 /* Scan expressions occuring in STMT, create access structures for all accesses
1072 to candidates for scalarization and remove those candidates which occur in
1073 statements or expressions that prevent them from being split apart. Return
1074 true if any access has been inserted. */
1077 build_accesses_from_assign (gimple stmt)
1080 struct access *lacc, *racc;
1082 if (!gimple_assign_single_p (stmt))
1085 lhs = gimple_assign_lhs (stmt);
1086 rhs = gimple_assign_rhs1 (stmt);
1088 if (disqualify_ops_if_throwing_stmt (stmt, lhs, rhs))
1091 racc = build_access_from_expr_1 (rhs, stmt, false);
1092 lacc = build_access_from_expr_1 (lhs, stmt, true);
1096 lacc->grp_assignment_write = 1;
1097 if (STRICT_ALIGNMENT && tree_non_aligned_mem_for_access_p (rhs, lacc))
1098 lacc->grp_unscalarizable_region = 1;
1103 racc->grp_assignment_read = 1;
1104 if (should_scalarize_away_bitmap && !gimple_has_volatile_ops (stmt)
1105 && !is_gimple_reg_type (racc->type))
1106 bitmap_set_bit (should_scalarize_away_bitmap, DECL_UID (racc->base));
1107 if (STRICT_ALIGNMENT && tree_non_aligned_mem_for_access_p (lhs, racc))
1108 racc->grp_unscalarizable_region = 1;
1112 && (sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1113 && !lacc->grp_unscalarizable_region
1114 && !racc->grp_unscalarizable_region
1115 && AGGREGATE_TYPE_P (TREE_TYPE (lhs))
1116 /* FIXME: Turn the following line into an assert after PR 40058 is
1118 && lacc->size == racc->size
1119 && useless_type_conversion_p (lacc->type, racc->type))
1121 struct assign_link *link;
1123 link = (struct assign_link *) pool_alloc (link_pool);
1124 memset (link, 0, sizeof (struct assign_link));
1129 add_link_to_rhs (racc, link);
1132 return lacc || racc;
1135 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1136 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1139 asm_visit_addr (gimple stmt ATTRIBUTE_UNUSED, tree op,
1140 void *data ATTRIBUTE_UNUSED)
1142 op = get_base_address (op);
1145 disqualify_candidate (op, "Non-scalarizable GIMPLE_ASM operand.");
1150 /* Return true iff callsite CALL has at least as many actual arguments as there
1151 are formal parameters of the function currently processed by IPA-SRA. */
1154 callsite_has_enough_arguments_p (gimple call)
1156 return gimple_call_num_args (call) >= (unsigned) func_param_count;
1159 /* Scan function and look for interesting expressions and create access
1160 structures for them. Return true iff any access is created. */
1163 scan_function (void)
1170 gimple_stmt_iterator gsi;
1171 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1173 gimple stmt = gsi_stmt (gsi);
1177 if (final_bbs && stmt_can_throw_external (stmt))
1178 bitmap_set_bit (final_bbs, bb->index);
1179 switch (gimple_code (stmt))
1182 t = gimple_return_retval (stmt);
1184 ret |= build_access_from_expr (t, stmt, false);
1186 bitmap_set_bit (final_bbs, bb->index);
1190 ret |= build_accesses_from_assign (stmt);
1194 for (i = 0; i < gimple_call_num_args (stmt); i++)
1195 ret |= build_access_from_expr (gimple_call_arg (stmt, i),
1198 if (sra_mode == SRA_MODE_EARLY_IPA)
1200 tree dest = gimple_call_fndecl (stmt);
1201 int flags = gimple_call_flags (stmt);
1205 if (DECL_BUILT_IN_CLASS (dest) == BUILT_IN_NORMAL
1206 && DECL_FUNCTION_CODE (dest) == BUILT_IN_APPLY_ARGS)
1207 encountered_apply_args = true;
1208 if (cgraph_get_node (dest)
1209 == cgraph_get_node (current_function_decl))
1211 encountered_recursive_call = true;
1212 if (!callsite_has_enough_arguments_p (stmt))
1213 encountered_unchangable_recursive_call = true;
1218 && (flags & (ECF_CONST | ECF_PURE)) == 0)
1219 bitmap_set_bit (final_bbs, bb->index);
1222 t = gimple_call_lhs (stmt);
1223 if (t && !disqualify_ops_if_throwing_stmt (stmt, t, NULL))
1224 ret |= build_access_from_expr (t, stmt, true);
1228 walk_stmt_load_store_addr_ops (stmt, NULL, NULL, NULL,
1231 bitmap_set_bit (final_bbs, bb->index);
1233 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
1235 t = TREE_VALUE (gimple_asm_input_op (stmt, i));
1236 ret |= build_access_from_expr (t, stmt, false);
1238 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
1240 t = TREE_VALUE (gimple_asm_output_op (stmt, i));
1241 ret |= build_access_from_expr (t, stmt, true);
1254 /* Helper of QSORT function. There are pointers to accesses in the array. An
1255 access is considered smaller than another if it has smaller offset or if the
1256 offsets are the same but is size is bigger. */
1259 compare_access_positions (const void *a, const void *b)
1261 const access_p *fp1 = (const access_p *) a;
1262 const access_p *fp2 = (const access_p *) b;
1263 const access_p f1 = *fp1;
1264 const access_p f2 = *fp2;
1266 if (f1->offset != f2->offset)
1267 return f1->offset < f2->offset ? -1 : 1;
1269 if (f1->size == f2->size)
1271 if (f1->type == f2->type)
1273 /* Put any non-aggregate type before any aggregate type. */
1274 else if (!is_gimple_reg_type (f1->type)
1275 && is_gimple_reg_type (f2->type))
1277 else if (is_gimple_reg_type (f1->type)
1278 && !is_gimple_reg_type (f2->type))
1280 /* Put any complex or vector type before any other scalar type. */
1281 else if (TREE_CODE (f1->type) != COMPLEX_TYPE
1282 && TREE_CODE (f1->type) != VECTOR_TYPE
1283 && (TREE_CODE (f2->type) == COMPLEX_TYPE
1284 || TREE_CODE (f2->type) == VECTOR_TYPE))
1286 else if ((TREE_CODE (f1->type) == COMPLEX_TYPE
1287 || TREE_CODE (f1->type) == VECTOR_TYPE)
1288 && TREE_CODE (f2->type) != COMPLEX_TYPE
1289 && TREE_CODE (f2->type) != VECTOR_TYPE)
1291 /* Put the integral type with the bigger precision first. */
1292 else if (INTEGRAL_TYPE_P (f1->type)
1293 && INTEGRAL_TYPE_P (f2->type))
1294 return TYPE_PRECISION (f2->type) - TYPE_PRECISION (f1->type);
1295 /* Put any integral type with non-full precision last. */
1296 else if (INTEGRAL_TYPE_P (f1->type)
1297 && (TREE_INT_CST_LOW (TYPE_SIZE (f1->type))
1298 != TYPE_PRECISION (f1->type)))
1300 else if (INTEGRAL_TYPE_P (f2->type)
1301 && (TREE_INT_CST_LOW (TYPE_SIZE (f2->type))
1302 != TYPE_PRECISION (f2->type)))
1304 /* Stabilize the sort. */
1305 return TYPE_UID (f1->type) - TYPE_UID (f2->type);
1308 /* We want the bigger accesses first, thus the opposite operator in the next
1310 return f1->size > f2->size ? -1 : 1;
1314 /* Append a name of the declaration to the name obstack. A helper function for
1318 make_fancy_decl_name (tree decl)
1322 tree name = DECL_NAME (decl);
1324 obstack_grow (&name_obstack, IDENTIFIER_POINTER (name),
1325 IDENTIFIER_LENGTH (name));
1328 sprintf (buffer, "D%u", DECL_UID (decl));
1329 obstack_grow (&name_obstack, buffer, strlen (buffer));
1333 /* Helper for make_fancy_name. */
1336 make_fancy_name_1 (tree expr)
1343 make_fancy_decl_name (expr);
1347 switch (TREE_CODE (expr))
1350 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1351 obstack_1grow (&name_obstack, '$');
1352 make_fancy_decl_name (TREE_OPERAND (expr, 1));
1356 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1357 obstack_1grow (&name_obstack, '$');
1358 /* Arrays with only one element may not have a constant as their
1360 index = TREE_OPERAND (expr, 1);
1361 if (TREE_CODE (index) != INTEGER_CST)
1363 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC, TREE_INT_CST_LOW (index));
1364 obstack_grow (&name_obstack, buffer, strlen (buffer));
1368 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1372 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1373 if (!integer_zerop (TREE_OPERAND (expr, 1)))
1375 obstack_1grow (&name_obstack, '$');
1376 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC,
1377 TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)));
1378 obstack_grow (&name_obstack, buffer, strlen (buffer));
1385 gcc_unreachable (); /* we treat these as scalars. */
1392 /* Create a human readable name for replacement variable of ACCESS. */
1395 make_fancy_name (tree expr)
1397 make_fancy_name_1 (expr);
1398 obstack_1grow (&name_obstack, '\0');
1399 return XOBFINISH (&name_obstack, char *);
1402 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1403 EXP_TYPE at the given OFFSET. If BASE is something for which
1404 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1405 to insert new statements either before or below the current one as specified
1406 by INSERT_AFTER. This function is not capable of handling bitfields. */
1409 build_ref_for_offset (location_t loc, tree base, HOST_WIDE_INT offset,
1410 tree exp_type, gimple_stmt_iterator *gsi,
1413 tree prev_base = base;
1415 HOST_WIDE_INT base_offset;
1417 gcc_checking_assert (offset % BITS_PER_UNIT == 0);
1419 base = get_addr_base_and_unit_offset (base, &base_offset);
1421 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1422 offset such as array[var_index]. */
1428 gcc_checking_assert (gsi);
1429 tmp = create_tmp_reg (build_pointer_type (TREE_TYPE (prev_base)), NULL);
1430 add_referenced_var (tmp);
1431 tmp = make_ssa_name (tmp, NULL);
1432 addr = build_fold_addr_expr (unshare_expr (prev_base));
1433 stmt = gimple_build_assign (tmp, addr);
1434 gimple_set_location (stmt, loc);
1435 SSA_NAME_DEF_STMT (tmp) = stmt;
1437 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
1439 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1442 off = build_int_cst (reference_alias_ptr_type (prev_base),
1443 offset / BITS_PER_UNIT);
1446 else if (TREE_CODE (base) == MEM_REF)
1448 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1449 base_offset + offset / BITS_PER_UNIT);
1450 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off, 0);
1451 base = unshare_expr (TREE_OPERAND (base, 0));
1455 off = build_int_cst (reference_alias_ptr_type (base),
1456 base_offset + offset / BITS_PER_UNIT);
1457 base = build_fold_addr_expr (unshare_expr (base));
1460 return fold_build2_loc (loc, MEM_REF, exp_type, base, off);
1463 DEF_VEC_ALLOC_P_STACK (tree);
1464 #define VEC_tree_stack_alloc(alloc) VEC_stack_alloc (tree, alloc)
1466 /* Construct a memory reference to a part of an aggregate BASE at the given
1467 OFFSET and of the type of MODEL. In case this is a chain of references
1468 to component, the function will replicate the chain of COMPONENT_REFs of
1469 the expression of MODEL to access it. GSI and INSERT_AFTER have the same
1470 meaning as in build_ref_for_offset. */
1473 build_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1474 struct access *model, gimple_stmt_iterator *gsi,
1477 tree type = model->type, t;
1478 VEC(tree,stack) *cr_stack = NULL;
1480 if (TREE_CODE (model->expr) == COMPONENT_REF)
1482 tree expr = model->expr;
1484 /* Create a stack of the COMPONENT_REFs so later we can walk them in
1485 order from inner to outer. */
1486 cr_stack = VEC_alloc (tree, stack, 6);
1489 tree field = TREE_OPERAND (expr, 1);
1490 HOST_WIDE_INT bit_pos = int_bit_position (field);
1492 /* We can be called with a model different from the one associated
1493 with BASE so we need to avoid going up the chain too far. */
1494 if (offset - bit_pos < 0)
1498 VEC_safe_push (tree, stack, cr_stack, expr);
1500 expr = TREE_OPERAND (expr, 0);
1501 type = TREE_TYPE (expr);
1502 } while (TREE_CODE (expr) == COMPONENT_REF);
1505 t = build_ref_for_offset (loc, base, offset, type, gsi, insert_after);
1507 if (TREE_CODE (model->expr) == COMPONENT_REF)
1512 /* Now replicate the chain of COMPONENT_REFs from inner to outer. */
1513 FOR_EACH_VEC_ELT_REVERSE (tree, cr_stack, i, expr)
1515 tree field = TREE_OPERAND (expr, 1);
1516 t = fold_build3_loc (loc, COMPONENT_REF, TREE_TYPE (field), t, field,
1520 VEC_free (tree, stack, cr_stack);
1526 /* Construct a memory reference consisting of component_refs and array_refs to
1527 a part of an aggregate *RES (which is of type TYPE). The requested part
1528 should have type EXP_TYPE at be the given OFFSET. This function might not
1529 succeed, it returns true when it does and only then *RES points to something
1530 meaningful. This function should be used only to build expressions that we
1531 might need to present to user (e.g. in warnings). In all other situations,
1532 build_ref_for_model or build_ref_for_offset should be used instead. */
1535 build_user_friendly_ref_for_offset (tree *res, tree type, HOST_WIDE_INT offset,
1541 tree tr_size, index, minidx;
1542 HOST_WIDE_INT el_size;
1544 if (offset == 0 && exp_type
1545 && types_compatible_p (exp_type, type))
1548 switch (TREE_CODE (type))
1551 case QUAL_UNION_TYPE:
1553 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
1555 HOST_WIDE_INT pos, size;
1556 tree expr, *expr_ptr;
1558 if (TREE_CODE (fld) != FIELD_DECL)
1561 pos = int_bit_position (fld);
1562 gcc_assert (TREE_CODE (type) == RECORD_TYPE || pos == 0);
1563 tr_size = DECL_SIZE (fld);
1564 if (!tr_size || !host_integerp (tr_size, 1))
1566 size = tree_low_cst (tr_size, 1);
1572 else if (pos > offset || (pos + size) <= offset)
1575 expr = build3 (COMPONENT_REF, TREE_TYPE (fld), *res, fld,
1578 if (build_user_friendly_ref_for_offset (expr_ptr, TREE_TYPE (fld),
1579 offset - pos, exp_type))
1588 tr_size = TYPE_SIZE (TREE_TYPE (type));
1589 if (!tr_size || !host_integerp (tr_size, 1))
1591 el_size = tree_low_cst (tr_size, 1);
1593 minidx = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
1594 if (TREE_CODE (minidx) != INTEGER_CST || el_size == 0)
1596 index = build_int_cst (TYPE_DOMAIN (type), offset / el_size);
1597 if (!integer_zerop (minidx))
1598 index = int_const_binop (PLUS_EXPR, index, minidx, 0);
1599 *res = build4 (ARRAY_REF, TREE_TYPE (type), *res, index,
1600 NULL_TREE, NULL_TREE);
1601 offset = offset % el_size;
1602 type = TREE_TYPE (type);
1617 /* Return true iff TYPE is stdarg va_list type. */
1620 is_va_list_type (tree type)
1622 return TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (va_list_type_node);
1625 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1626 those with type which is suitable for scalarization. */
1629 find_var_candidates (void)
1632 referenced_var_iterator rvi;
1635 FOR_EACH_REFERENCED_VAR (cfun, var, rvi)
1637 if (TREE_CODE (var) != VAR_DECL && TREE_CODE (var) != PARM_DECL)
1639 type = TREE_TYPE (var);
1641 if (!AGGREGATE_TYPE_P (type)
1642 || needs_to_live_in_memory (var)
1643 || TREE_THIS_VOLATILE (var)
1644 || !COMPLETE_TYPE_P (type)
1645 || !host_integerp (TYPE_SIZE (type), 1)
1646 || tree_low_cst (TYPE_SIZE (type), 1) == 0
1647 || type_internals_preclude_sra_p (type)
1648 /* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1649 we also want to schedule it rather late. Thus we ignore it in
1651 || (sra_mode == SRA_MODE_EARLY_INTRA
1652 && is_va_list_type (type)))
1655 bitmap_set_bit (candidate_bitmap, DECL_UID (var));
1657 if (dump_file && (dump_flags & TDF_DETAILS))
1659 fprintf (dump_file, "Candidate (%d): ", DECL_UID (var));
1660 print_generic_expr (dump_file, var, 0);
1661 fprintf (dump_file, "\n");
1669 /* Sort all accesses for the given variable, check for partial overlaps and
1670 return NULL if there are any. If there are none, pick a representative for
1671 each combination of offset and size and create a linked list out of them.
1672 Return the pointer to the first representative and make sure it is the first
1673 one in the vector of accesses. */
1675 static struct access *
1676 sort_and_splice_var_accesses (tree var)
1678 int i, j, access_count;
1679 struct access *res, **prev_acc_ptr = &res;
1680 VEC (access_p, heap) *access_vec;
1682 HOST_WIDE_INT low = -1, high = 0;
1684 access_vec = get_base_access_vector (var);
1687 access_count = VEC_length (access_p, access_vec);
1689 /* Sort by <OFFSET, SIZE>. */
1690 VEC_qsort (access_p, access_vec, compare_access_positions);
1693 while (i < access_count)
1695 struct access *access = VEC_index (access_p, access_vec, i);
1696 bool grp_write = access->write;
1697 bool grp_read = !access->write;
1698 bool grp_scalar_write = access->write
1699 && is_gimple_reg_type (access->type);
1700 bool grp_scalar_read = !access->write
1701 && is_gimple_reg_type (access->type);
1702 bool grp_assignment_read = access->grp_assignment_read;
1703 bool grp_assignment_write = access->grp_assignment_write;
1704 bool multiple_scalar_reads = false;
1705 bool total_scalarization = access->total_scalarization;
1706 bool grp_partial_lhs = access->grp_partial_lhs;
1707 bool first_scalar = is_gimple_reg_type (access->type);
1708 bool unscalarizable_region = access->grp_unscalarizable_region;
1710 if (first || access->offset >= high)
1713 low = access->offset;
1714 high = access->offset + access->size;
1716 else if (access->offset > low && access->offset + access->size > high)
1719 gcc_assert (access->offset >= low
1720 && access->offset + access->size <= high);
1723 while (j < access_count)
1725 struct access *ac2 = VEC_index (access_p, access_vec, j);
1726 if (ac2->offset != access->offset || ac2->size != access->size)
1731 grp_scalar_write = (grp_scalar_write
1732 || is_gimple_reg_type (ac2->type));
1737 if (is_gimple_reg_type (ac2->type))
1739 if (grp_scalar_read)
1740 multiple_scalar_reads = true;
1742 grp_scalar_read = true;
1745 grp_assignment_read |= ac2->grp_assignment_read;
1746 grp_assignment_write |= ac2->grp_assignment_write;
1747 grp_partial_lhs |= ac2->grp_partial_lhs;
1748 unscalarizable_region |= ac2->grp_unscalarizable_region;
1749 total_scalarization |= ac2->total_scalarization;
1750 relink_to_new_repr (access, ac2);
1752 /* If there are both aggregate-type and scalar-type accesses with
1753 this combination of size and offset, the comparison function
1754 should have put the scalars first. */
1755 gcc_assert (first_scalar || !is_gimple_reg_type (ac2->type));
1756 ac2->group_representative = access;
1762 access->group_representative = access;
1763 access->grp_write = grp_write;
1764 access->grp_read = grp_read;
1765 access->grp_scalar_read = grp_scalar_read;
1766 access->grp_scalar_write = grp_scalar_write;
1767 access->grp_assignment_read = grp_assignment_read;
1768 access->grp_assignment_write = grp_assignment_write;
1769 access->grp_hint = multiple_scalar_reads || total_scalarization;
1770 access->grp_partial_lhs = grp_partial_lhs;
1771 access->grp_unscalarizable_region = unscalarizable_region;
1772 if (access->first_link)
1773 add_access_to_work_queue (access);
1775 *prev_acc_ptr = access;
1776 prev_acc_ptr = &access->next_grp;
1779 gcc_assert (res == VEC_index (access_p, access_vec, 0));
1783 /* Create a variable for the given ACCESS which determines the type, name and a
1784 few other properties. Return the variable declaration and store it also to
1785 ACCESS->replacement. */
1788 create_access_replacement (struct access *access, bool rename)
1792 repl = create_tmp_var (access->type, "SR");
1794 add_referenced_var (repl);
1796 mark_sym_for_renaming (repl);
1798 if (!access->grp_partial_lhs
1799 && (TREE_CODE (access->type) == COMPLEX_TYPE
1800 || TREE_CODE (access->type) == VECTOR_TYPE))
1801 DECL_GIMPLE_REG_P (repl) = 1;
1803 DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
1804 DECL_ARTIFICIAL (repl) = 1;
1805 DECL_IGNORED_P (repl) = DECL_IGNORED_P (access->base);
1807 if (DECL_NAME (access->base)
1808 && !DECL_IGNORED_P (access->base)
1809 && !DECL_ARTIFICIAL (access->base))
1811 char *pretty_name = make_fancy_name (access->expr);
1812 tree debug_expr = unshare_expr (access->expr), d;
1814 DECL_NAME (repl) = get_identifier (pretty_name);
1815 obstack_free (&name_obstack, pretty_name);
1817 /* Get rid of any SSA_NAMEs embedded in debug_expr,
1818 as DECL_DEBUG_EXPR isn't considered when looking for still
1819 used SSA_NAMEs and thus they could be freed. All debug info
1820 generation cares is whether something is constant or variable
1821 and that get_ref_base_and_extent works properly on the
1823 for (d = debug_expr; handled_component_p (d); d = TREE_OPERAND (d, 0))
1824 switch (TREE_CODE (d))
1827 case ARRAY_RANGE_REF:
1828 if (TREE_OPERAND (d, 1)
1829 && TREE_CODE (TREE_OPERAND (d, 1)) == SSA_NAME)
1830 TREE_OPERAND (d, 1) = SSA_NAME_VAR (TREE_OPERAND (d, 1));
1831 if (TREE_OPERAND (d, 3)
1832 && TREE_CODE (TREE_OPERAND (d, 3)) == SSA_NAME)
1833 TREE_OPERAND (d, 3) = SSA_NAME_VAR (TREE_OPERAND (d, 3));
1836 if (TREE_OPERAND (d, 2)
1837 && TREE_CODE (TREE_OPERAND (d, 2)) == SSA_NAME)
1838 TREE_OPERAND (d, 2) = SSA_NAME_VAR (TREE_OPERAND (d, 2));
1843 SET_DECL_DEBUG_EXPR (repl, debug_expr);
1844 DECL_DEBUG_EXPR_IS_FROM (repl) = 1;
1845 if (access->grp_no_warning)
1846 TREE_NO_WARNING (repl) = 1;
1848 TREE_NO_WARNING (repl) = TREE_NO_WARNING (access->base);
1851 TREE_NO_WARNING (repl) = 1;
1855 fprintf (dump_file, "Created a replacement for ");
1856 print_generic_expr (dump_file, access->base, 0);
1857 fprintf (dump_file, " offset: %u, size: %u: ",
1858 (unsigned) access->offset, (unsigned) access->size);
1859 print_generic_expr (dump_file, repl, 0);
1860 fprintf (dump_file, "\n");
1862 sra_stats.replacements++;
1867 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
1870 get_access_replacement (struct access *access)
1872 gcc_assert (access->grp_to_be_replaced);
1874 if (!access->replacement_decl)
1875 access->replacement_decl = create_access_replacement (access, true);
1876 return access->replacement_decl;
1879 /* Return ACCESS scalar replacement, create it if it does not exist yet but do
1880 not mark it for renaming. */
1883 get_unrenamed_access_replacement (struct access *access)
1885 gcc_assert (!access->grp_to_be_replaced);
1887 if (!access->replacement_decl)
1888 access->replacement_decl = create_access_replacement (access, false);
1889 return access->replacement_decl;
1893 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
1894 linked list along the way. Stop when *ACCESS is NULL or the access pointed
1895 to it is not "within" the root. Return false iff some accesses partially
1899 build_access_subtree (struct access **access)
1901 struct access *root = *access, *last_child = NULL;
1902 HOST_WIDE_INT limit = root->offset + root->size;
1904 *access = (*access)->next_grp;
1905 while (*access && (*access)->offset + (*access)->size <= limit)
1908 root->first_child = *access;
1910 last_child->next_sibling = *access;
1911 last_child = *access;
1913 if (!build_access_subtree (access))
1917 if (*access && (*access)->offset < limit)
1923 /* Build a tree of access representatives, ACCESS is the pointer to the first
1924 one, others are linked in a list by the next_grp field. Return false iff
1925 some accesses partially overlap. */
1928 build_access_trees (struct access *access)
1932 struct access *root = access;
1934 if (!build_access_subtree (&access))
1936 root->next_grp = access;
1941 /* Return true if expr contains some ARRAY_REFs into a variable bounded
1945 expr_with_var_bounded_array_refs_p (tree expr)
1947 while (handled_component_p (expr))
1949 if (TREE_CODE (expr) == ARRAY_REF
1950 && !host_integerp (array_ref_low_bound (expr), 0))
1952 expr = TREE_OPERAND (expr, 0);
1957 enum mark_rw_status { SRA_MRRW_NOTHING, SRA_MRRW_DIRECT, SRA_MRRW_ASSIGN};
1959 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
1960 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
1961 sorts of access flags appropriately along the way, notably always set
1962 grp_read and grp_assign_read according to MARK_READ and grp_write when
1965 Creating a replacement for a scalar access is considered beneficial if its
1966 grp_hint is set (this means we are either attempting total scalarization or
1967 there is more than one direct read access) or according to the following
1970 Access written to through a scalar type (once or more times)
1972 | Written to in an assignment statement
1974 | | Access read as scalar _once_
1976 | | | Read in an assignment statement
1978 | | | | Scalarize Comment
1979 -----------------------------------------------------------------------------
1980 0 0 0 0 No access for the scalar
1981 0 0 0 1 No access for the scalar
1982 0 0 1 0 No Single read - won't help
1983 0 0 1 1 No The same case
1984 0 1 0 0 No access for the scalar
1985 0 1 0 1 No access for the scalar
1986 0 1 1 0 Yes s = *g; return s.i;
1987 0 1 1 1 Yes The same case as above
1988 1 0 0 0 No Won't help
1989 1 0 0 1 Yes s.i = 1; *g = s;
1990 1 0 1 0 Yes s.i = 5; g = s.i;
1991 1 0 1 1 Yes The same case as above
1992 1 1 0 0 No Won't help.
1993 1 1 0 1 Yes s.i = 1; *g = s;
1994 1 1 1 0 Yes s = *g; return s.i;
1995 1 1 1 1 Yes Any of the above yeses */
1998 analyze_access_subtree (struct access *root, bool allow_replacements,
1999 enum mark_rw_status mark_read,
2000 enum mark_rw_status mark_write)
2002 struct access *child;
2003 HOST_WIDE_INT limit = root->offset + root->size;
2004 HOST_WIDE_INT covered_to = root->offset;
2005 bool scalar = is_gimple_reg_type (root->type);
2006 bool hole = false, sth_created = false;
2008 if (root->grp_assignment_read)
2009 mark_read = SRA_MRRW_ASSIGN;
2010 else if (mark_read == SRA_MRRW_ASSIGN)
2013 root->grp_assignment_read = 1;
2015 else if (mark_read == SRA_MRRW_DIRECT)
2017 else if (root->grp_read)
2018 mark_read = SRA_MRRW_DIRECT;
2020 if (root->grp_assignment_write)
2021 mark_write = SRA_MRRW_ASSIGN;
2022 else if (mark_write == SRA_MRRW_ASSIGN)
2024 root->grp_write = 1;
2025 root->grp_assignment_write = 1;
2027 else if (mark_write == SRA_MRRW_DIRECT)
2028 root->grp_write = 1;
2029 else if (root->grp_write)
2030 mark_write = SRA_MRRW_DIRECT;
2032 if (root->grp_unscalarizable_region)
2033 allow_replacements = false;
2035 if (allow_replacements && expr_with_var_bounded_array_refs_p (root->expr))
2036 allow_replacements = false;
2038 for (child = root->first_child; child; child = child->next_sibling)
2040 if (!hole && child->offset < covered_to)
2043 covered_to += child->size;
2045 sth_created |= analyze_access_subtree (child,
2046 allow_replacements && !scalar,
2047 mark_read, mark_write);
2049 root->grp_unscalarized_data |= child->grp_unscalarized_data;
2050 hole |= !child->grp_covered;
2053 if (allow_replacements && scalar && !root->first_child
2055 || ((root->grp_scalar_read || root->grp_assignment_read)
2056 && (root->grp_scalar_write || root->grp_assignment_write))))
2058 bool new_integer_type;
2059 if (TREE_CODE (root->type) == ENUMERAL_TYPE)
2061 tree rt = root->type;
2062 root->type = build_nonstandard_integer_type (TYPE_PRECISION (rt),
2063 TYPE_UNSIGNED (rt));
2064 new_integer_type = true;
2067 new_integer_type = false;
2069 if (dump_file && (dump_flags & TDF_DETAILS))
2071 fprintf (dump_file, "Marking ");
2072 print_generic_expr (dump_file, root->base, 0);
2073 fprintf (dump_file, " offset: %u, size: %u ",
2074 (unsigned) root->offset, (unsigned) root->size);
2075 fprintf (dump_file, " to be replaced%s.\n",
2076 new_integer_type ? " with an integer": "");
2079 root->grp_to_be_replaced = 1;
2083 else if (covered_to < limit)
2086 if (sth_created && !hole)
2088 root->grp_covered = 1;
2091 if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
2092 root->grp_unscalarized_data = 1; /* not covered and written to */
2098 /* Analyze all access trees linked by next_grp by the means of
2099 analyze_access_subtree. */
2101 analyze_access_trees (struct access *access)
2107 if (analyze_access_subtree (access, true,
2108 SRA_MRRW_NOTHING, SRA_MRRW_NOTHING))
2110 access = access->next_grp;
2116 /* Return true iff a potential new child of LACC at offset OFFSET and with size
2117 SIZE would conflict with an already existing one. If exactly such a child
2118 already exists in LACC, store a pointer to it in EXACT_MATCH. */
2121 child_would_conflict_in_lacc (struct access *lacc, HOST_WIDE_INT norm_offset,
2122 HOST_WIDE_INT size, struct access **exact_match)
2124 struct access *child;
2126 for (child = lacc->first_child; child; child = child->next_sibling)
2128 if (child->offset == norm_offset && child->size == size)
2130 *exact_match = child;
2134 if (child->offset < norm_offset + size
2135 && child->offset + child->size > norm_offset)
2142 /* Create a new child access of PARENT, with all properties just like MODEL
2143 except for its offset and with its grp_write false and grp_read true.
2144 Return the new access or NULL if it cannot be created. Note that this access
2145 is created long after all splicing and sorting, it's not located in any
2146 access vector and is automatically a representative of its group. */
2148 static struct access *
2149 create_artificial_child_access (struct access *parent, struct access *model,
2150 HOST_WIDE_INT new_offset)
2152 struct access *access;
2153 struct access **child;
2154 tree expr = parent->base;
2156 gcc_assert (!model->grp_unscalarizable_region);
2158 access = (struct access *) pool_alloc (access_pool);
2159 memset (access, 0, sizeof (struct access));
2160 if (!build_user_friendly_ref_for_offset (&expr, TREE_TYPE (expr), new_offset,
2163 access->grp_no_warning = true;
2164 expr = build_ref_for_model (EXPR_LOCATION (parent->base), parent->base,
2165 new_offset, model, NULL, false);
2168 access->base = parent->base;
2169 access->expr = expr;
2170 access->offset = new_offset;
2171 access->size = model->size;
2172 access->type = model->type;
2173 access->grp_write = true;
2174 access->grp_read = false;
2176 child = &parent->first_child;
2177 while (*child && (*child)->offset < new_offset)
2178 child = &(*child)->next_sibling;
2180 access->next_sibling = *child;
2187 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2188 true if any new subaccess was created. Additionally, if RACC is a scalar
2189 access but LACC is not, change the type of the latter, if possible. */
2192 propagate_subaccesses_across_link (struct access *lacc, struct access *racc)
2194 struct access *rchild;
2195 HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
2198 if (is_gimple_reg_type (lacc->type)
2199 || lacc->grp_unscalarizable_region
2200 || racc->grp_unscalarizable_region)
2203 if (!lacc->first_child && !racc->first_child
2204 && is_gimple_reg_type (racc->type))
2206 tree t = lacc->base;
2208 lacc->type = racc->type;
2209 if (build_user_friendly_ref_for_offset (&t, TREE_TYPE (t), lacc->offset,
2214 lacc->expr = build_ref_for_model (EXPR_LOCATION (lacc->base),
2215 lacc->base, lacc->offset,
2217 lacc->grp_no_warning = true;
2222 for (rchild = racc->first_child; rchild; rchild = rchild->next_sibling)
2224 struct access *new_acc = NULL;
2225 HOST_WIDE_INT norm_offset = rchild->offset + norm_delta;
2227 if (rchild->grp_unscalarizable_region)
2230 if (child_would_conflict_in_lacc (lacc, norm_offset, rchild->size,
2235 rchild->grp_hint = 1;
2236 new_acc->grp_hint |= new_acc->grp_read;
2237 if (rchild->first_child)
2238 ret |= propagate_subaccesses_across_link (new_acc, rchild);
2243 rchild->grp_hint = 1;
2244 new_acc = create_artificial_child_access (lacc, rchild, norm_offset);
2248 if (racc->first_child)
2249 propagate_subaccesses_across_link (new_acc, rchild);
2256 /* Propagate all subaccesses across assignment links. */
2259 propagate_all_subaccesses (void)
2261 while (work_queue_head)
2263 struct access *racc = pop_access_from_work_queue ();
2264 struct assign_link *link;
2266 gcc_assert (racc->first_link);
2268 for (link = racc->first_link; link; link = link->next)
2270 struct access *lacc = link->lacc;
2272 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (lacc->base)))
2274 lacc = lacc->group_representative;
2275 if (propagate_subaccesses_across_link (lacc, racc)
2276 && lacc->first_link)
2277 add_access_to_work_queue (lacc);
2282 /* Go through all accesses collected throughout the (intraprocedural) analysis
2283 stage, exclude overlapping ones, identify representatives and build trees
2284 out of them, making decisions about scalarization on the way. Return true
2285 iff there are any to-be-scalarized variables after this stage. */
2288 analyze_all_variable_accesses (void)
2291 bitmap tmp = BITMAP_ALLOC (NULL);
2293 unsigned i, max_total_scalarization_size;
2295 max_total_scalarization_size = UNITS_PER_WORD * BITS_PER_UNIT
2296 * MOVE_RATIO (optimize_function_for_speed_p (cfun));
2298 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
2299 if (bitmap_bit_p (should_scalarize_away_bitmap, i)
2300 && !bitmap_bit_p (cannot_scalarize_away_bitmap, i))
2302 tree var = referenced_var (i);
2304 if (TREE_CODE (var) == VAR_DECL
2305 && ((unsigned) tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1)
2306 <= max_total_scalarization_size)
2307 && type_consists_of_records_p (TREE_TYPE (var)))
2309 completely_scalarize_record (var, var, 0, var);
2310 if (dump_file && (dump_flags & TDF_DETAILS))
2312 fprintf (dump_file, "Will attempt to totally scalarize ");
2313 print_generic_expr (dump_file, var, 0);
2314 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2319 bitmap_copy (tmp, candidate_bitmap);
2320 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2322 tree var = referenced_var (i);
2323 struct access *access;
2325 access = sort_and_splice_var_accesses (var);
2326 if (!access || !build_access_trees (access))
2327 disqualify_candidate (var,
2328 "No or inhibitingly overlapping accesses.");
2331 propagate_all_subaccesses ();
2333 bitmap_copy (tmp, candidate_bitmap);
2334 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2336 tree var = referenced_var (i);
2337 struct access *access = get_first_repr_for_decl (var);
2339 if (analyze_access_trees (access))
2342 if (dump_file && (dump_flags & TDF_DETAILS))
2344 fprintf (dump_file, "\nAccess trees for ");
2345 print_generic_expr (dump_file, var, 0);
2346 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2347 dump_access_tree (dump_file, access);
2348 fprintf (dump_file, "\n");
2352 disqualify_candidate (var, "No scalar replacements to be created.");
2359 statistics_counter_event (cfun, "Scalarized aggregates", res);
2366 /* Generate statements copying scalar replacements of accesses within a subtree
2367 into or out of AGG. ACCESS, all its children, siblings and their children
2368 are to be processed. AGG is an aggregate type expression (can be a
2369 declaration but does not have to be, it can for example also be a mem_ref or
2370 a series of handled components). TOP_OFFSET is the offset of the processed
2371 subtree which has to be subtracted from offsets of individual accesses to
2372 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2373 replacements in the interval <start_offset, start_offset + chunk_size>,
2374 otherwise copy all. GSI is a statement iterator used to place the new
2375 statements. WRITE should be true when the statements should write from AGG
2376 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2377 statements will be added after the current statement in GSI, they will be
2378 added before the statement otherwise. */
2381 generate_subtree_copies (struct access *access, tree agg,
2382 HOST_WIDE_INT top_offset,
2383 HOST_WIDE_INT start_offset, HOST_WIDE_INT chunk_size,
2384 gimple_stmt_iterator *gsi, bool write,
2385 bool insert_after, location_t loc)
2389 if (chunk_size && access->offset >= start_offset + chunk_size)
2392 if (access->grp_to_be_replaced
2394 || access->offset + access->size > start_offset))
2396 tree expr, repl = get_access_replacement (access);
2399 expr = build_ref_for_model (loc, agg, access->offset - top_offset,
2400 access, gsi, insert_after);
2404 if (access->grp_partial_lhs)
2405 expr = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE,
2407 insert_after ? GSI_NEW_STMT
2409 stmt = gimple_build_assign (repl, expr);
2413 TREE_NO_WARNING (repl) = 1;
2414 if (access->grp_partial_lhs)
2415 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2417 insert_after ? GSI_NEW_STMT
2419 stmt = gimple_build_assign (expr, repl);
2421 gimple_set_location (stmt, loc);
2424 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2426 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2428 sra_stats.subtree_copies++;
2431 if (access->first_child)
2432 generate_subtree_copies (access->first_child, agg, top_offset,
2433 start_offset, chunk_size, gsi,
2434 write, insert_after, loc);
2436 access = access->next_sibling;
2441 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2442 the root of the subtree to be processed. GSI is the statement iterator used
2443 for inserting statements which are added after the current statement if
2444 INSERT_AFTER is true or before it otherwise. */
2447 init_subtree_with_zero (struct access *access, gimple_stmt_iterator *gsi,
2448 bool insert_after, location_t loc)
2451 struct access *child;
2453 if (access->grp_to_be_replaced)
2457 stmt = gimple_build_assign (get_access_replacement (access),
2458 build_zero_cst (access->type));
2460 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2462 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2464 gimple_set_location (stmt, loc);
2467 for (child = access->first_child; child; child = child->next_sibling)
2468 init_subtree_with_zero (child, gsi, insert_after, loc);
2471 /* Search for an access representative for the given expression EXPR and
2472 return it or NULL if it cannot be found. */
2474 static struct access *
2475 get_access_for_expr (tree expr)
2477 HOST_WIDE_INT offset, size, max_size;
2480 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2481 a different size than the size of its argument and we need the latter
2483 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
2484 expr = TREE_OPERAND (expr, 0);
2486 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
2487 if (max_size == -1 || !DECL_P (base))
2490 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
2493 return get_var_base_offset_size_access (base, offset, max_size);
2496 /* Replace the expression EXPR with a scalar replacement if there is one and
2497 generate other statements to do type conversion or subtree copying if
2498 necessary. GSI is used to place newly created statements, WRITE is true if
2499 the expression is being written to (it is on a LHS of a statement or output
2500 in an assembly statement). */
2503 sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write)
2506 struct access *access;
2509 if (TREE_CODE (*expr) == BIT_FIELD_REF)
2512 expr = &TREE_OPERAND (*expr, 0);
2517 if (TREE_CODE (*expr) == REALPART_EXPR || TREE_CODE (*expr) == IMAGPART_EXPR)
2518 expr = &TREE_OPERAND (*expr, 0);
2519 access = get_access_for_expr (*expr);
2522 type = TREE_TYPE (*expr);
2524 loc = gimple_location (gsi_stmt (*gsi));
2525 if (access->grp_to_be_replaced)
2527 tree repl = get_access_replacement (access);
2528 /* If we replace a non-register typed access simply use the original
2529 access expression to extract the scalar component afterwards.
2530 This happens if scalarizing a function return value or parameter
2531 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2532 gcc.c-torture/compile/20011217-1.c.
2534 We also want to use this when accessing a complex or vector which can
2535 be accessed as a different type too, potentially creating a need for
2536 type conversion (see PR42196) and when scalarized unions are involved
2537 in assembler statements (see PR42398). */
2538 if (!useless_type_conversion_p (type, access->type))
2542 ref = build_ref_for_model (loc, access->base, access->offset, access,
2549 if (access->grp_partial_lhs)
2550 ref = force_gimple_operand_gsi (gsi, ref, true, NULL_TREE,
2551 false, GSI_NEW_STMT);
2552 stmt = gimple_build_assign (repl, ref);
2553 gimple_set_location (stmt, loc);
2554 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2560 if (access->grp_partial_lhs)
2561 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2562 true, GSI_SAME_STMT);
2563 stmt = gimple_build_assign (ref, repl);
2564 gimple_set_location (stmt, loc);
2565 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2573 if (access->first_child)
2575 HOST_WIDE_INT start_offset, chunk_size;
2577 && host_integerp (TREE_OPERAND (bfr, 1), 1)
2578 && host_integerp (TREE_OPERAND (bfr, 2), 1))
2580 chunk_size = tree_low_cst (TREE_OPERAND (bfr, 1), 1);
2581 start_offset = access->offset
2582 + tree_low_cst (TREE_OPERAND (bfr, 2), 1);
2585 start_offset = chunk_size = 0;
2587 generate_subtree_copies (access->first_child, access->base, 0,
2588 start_offset, chunk_size, gsi, write, write,
2594 /* Where scalar replacements of the RHS have been written to when a replacement
2595 of a LHS of an assigments cannot be direclty loaded from a replacement of
2597 enum unscalarized_data_handling { SRA_UDH_NONE, /* Nothing done so far. */
2598 SRA_UDH_RIGHT, /* Data flushed to the RHS. */
2599 SRA_UDH_LEFT }; /* Data flushed to the LHS. */
2601 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2602 base aggregate if there are unscalarized data or directly to LHS of the
2603 statement that is pointed to by GSI otherwise. */
2605 static enum unscalarized_data_handling
2606 handle_unscalarized_data_in_subtree (struct access *top_racc,
2607 gimple_stmt_iterator *gsi)
2609 if (top_racc->grp_unscalarized_data)
2611 generate_subtree_copies (top_racc->first_child, top_racc->base, 0, 0, 0,
2613 gimple_location (gsi_stmt (*gsi)));
2614 return SRA_UDH_RIGHT;
2618 tree lhs = gimple_assign_lhs (gsi_stmt (*gsi));
2619 generate_subtree_copies (top_racc->first_child, lhs, top_racc->offset,
2620 0, 0, gsi, false, false,
2621 gimple_location (gsi_stmt (*gsi)));
2622 return SRA_UDH_LEFT;
2627 /* Try to generate statements to load all sub-replacements in an access subtree
2628 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2629 If that is not possible, refresh the TOP_RACC base aggregate and load the
2630 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2631 copied. NEW_GSI is stmt iterator used for statement insertions after the
2632 original assignment, OLD_GSI is used to insert statements before the
2633 assignment. *REFRESHED keeps the information whether we have needed to
2634 refresh replacements of the LHS and from which side of the assignments this
2638 load_assign_lhs_subreplacements (struct access *lacc, struct access *top_racc,
2639 HOST_WIDE_INT left_offset,
2640 gimple_stmt_iterator *old_gsi,
2641 gimple_stmt_iterator *new_gsi,
2642 enum unscalarized_data_handling *refreshed)
2644 location_t loc = gimple_location (gsi_stmt (*old_gsi));
2645 for (lacc = lacc->first_child; lacc; lacc = lacc->next_sibling)
2647 if (lacc->grp_to_be_replaced)
2649 struct access *racc;
2650 HOST_WIDE_INT offset = lacc->offset - left_offset + top_racc->offset;
2654 racc = find_access_in_subtree (top_racc, offset, lacc->size);
2655 if (racc && racc->grp_to_be_replaced)
2657 rhs = get_access_replacement (racc);
2658 if (!useless_type_conversion_p (lacc->type, racc->type))
2659 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, lacc->type, rhs);
2661 if (racc->grp_partial_lhs && lacc->grp_partial_lhs)
2662 rhs = force_gimple_operand_gsi (old_gsi, rhs, true, NULL_TREE,
2663 true, GSI_SAME_STMT);
2667 /* No suitable access on the right hand side, need to load from
2668 the aggregate. See if we have to update it first... */
2669 if (*refreshed == SRA_UDH_NONE)
2670 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2673 if (*refreshed == SRA_UDH_LEFT)
2674 rhs = build_ref_for_model (loc, lacc->base, lacc->offset, lacc,
2677 rhs = build_ref_for_model (loc, top_racc->base, offset, lacc,
2679 if (lacc->grp_partial_lhs)
2680 rhs = force_gimple_operand_gsi (new_gsi, rhs, true, NULL_TREE,
2681 false, GSI_NEW_STMT);
2684 stmt = gimple_build_assign (get_access_replacement (lacc), rhs);
2685 gsi_insert_after (new_gsi, stmt, GSI_NEW_STMT);
2686 gimple_set_location (stmt, loc);
2688 sra_stats.subreplacements++;
2690 else if (*refreshed == SRA_UDH_NONE
2691 && lacc->grp_read && !lacc->grp_covered)
2692 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2695 if (lacc->first_child)
2696 load_assign_lhs_subreplacements (lacc, top_racc, left_offset,
2697 old_gsi, new_gsi, refreshed);
2701 /* Result code for SRA assignment modification. */
2702 enum assignment_mod_result { SRA_AM_NONE, /* nothing done for the stmt */
2703 SRA_AM_MODIFIED, /* stmt changed but not
2705 SRA_AM_REMOVED }; /* stmt eliminated */
2707 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2708 to the assignment and GSI is the statement iterator pointing at it. Returns
2709 the same values as sra_modify_assign. */
2711 static enum assignment_mod_result
2712 sra_modify_constructor_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2714 tree lhs = gimple_assign_lhs (*stmt);
2718 acc = get_access_for_expr (lhs);
2722 loc = gimple_location (*stmt);
2723 if (VEC_length (constructor_elt,
2724 CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt))) > 0)
2726 /* I have never seen this code path trigger but if it can happen the
2727 following should handle it gracefully. */
2728 if (access_has_children_p (acc))
2729 generate_subtree_copies (acc->first_child, acc->base, 0, 0, 0, gsi,
2731 return SRA_AM_MODIFIED;
2734 if (acc->grp_covered)
2736 init_subtree_with_zero (acc, gsi, false, loc);
2737 unlink_stmt_vdef (*stmt);
2738 gsi_remove (gsi, true);
2739 return SRA_AM_REMOVED;
2743 init_subtree_with_zero (acc, gsi, true, loc);
2744 return SRA_AM_MODIFIED;
2748 /* Create and return a new suitable default definition SSA_NAME for RACC which
2749 is an access describing an uninitialized part of an aggregate that is being
2753 get_repl_default_def_ssa_name (struct access *racc)
2757 decl = get_unrenamed_access_replacement (racc);
2759 repl = gimple_default_def (cfun, decl);
2762 repl = make_ssa_name (decl, gimple_build_nop ());
2763 set_default_def (decl, repl);
2769 /* Return true if REF has a COMPONENT_REF with a bit-field field declaration
2773 contains_bitfld_comp_ref_p (const_tree ref)
2775 while (handled_component_p (ref))
2777 if (TREE_CODE (ref) == COMPONENT_REF
2778 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1)))
2780 ref = TREE_OPERAND (ref, 0);
2786 /* Return true if REF has an VIEW_CONVERT_EXPR or a COMPONENT_REF with a
2787 bit-field field declaration somewhere in it. */
2790 contains_vce_or_bfcref_p (const_tree ref)
2792 while (handled_component_p (ref))
2794 if (TREE_CODE (ref) == VIEW_CONVERT_EXPR
2795 || (TREE_CODE (ref) == COMPONENT_REF
2796 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))))
2798 ref = TREE_OPERAND (ref, 0);
2804 /* Examine both sides of the assignment statement pointed to by STMT, replace
2805 them with a scalare replacement if there is one and generate copying of
2806 replacements if scalarized aggregates have been used in the assignment. GSI
2807 is used to hold generated statements for type conversions and subtree
2810 static enum assignment_mod_result
2811 sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
2813 struct access *lacc, *racc;
2815 bool modify_this_stmt = false;
2816 bool force_gimple_rhs = false;
2818 gimple_stmt_iterator orig_gsi = *gsi;
2820 if (!gimple_assign_single_p (*stmt))
2822 lhs = gimple_assign_lhs (*stmt);
2823 rhs = gimple_assign_rhs1 (*stmt);
2825 if (TREE_CODE (rhs) == CONSTRUCTOR)
2826 return sra_modify_constructor_assign (stmt, gsi);
2828 if (TREE_CODE (rhs) == REALPART_EXPR || TREE_CODE (lhs) == REALPART_EXPR
2829 || TREE_CODE (rhs) == IMAGPART_EXPR || TREE_CODE (lhs) == IMAGPART_EXPR
2830 || TREE_CODE (rhs) == BIT_FIELD_REF || TREE_CODE (lhs) == BIT_FIELD_REF)
2832 modify_this_stmt = sra_modify_expr (gimple_assign_rhs1_ptr (*stmt),
2834 modify_this_stmt |= sra_modify_expr (gimple_assign_lhs_ptr (*stmt),
2836 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
2839 lacc = get_access_for_expr (lhs);
2840 racc = get_access_for_expr (rhs);
2844 loc = gimple_location (*stmt);
2845 if (lacc && lacc->grp_to_be_replaced)
2847 lhs = get_access_replacement (lacc);
2848 gimple_assign_set_lhs (*stmt, lhs);
2849 modify_this_stmt = true;
2850 if (lacc->grp_partial_lhs)
2851 force_gimple_rhs = true;
2855 if (racc && racc->grp_to_be_replaced)
2857 rhs = get_access_replacement (racc);
2858 modify_this_stmt = true;
2859 if (racc->grp_partial_lhs)
2860 force_gimple_rhs = true;
2864 if (modify_this_stmt)
2866 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2868 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
2869 ??? This should move to fold_stmt which we simply should
2870 call after building a VIEW_CONVERT_EXPR here. */
2871 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
2872 && !contains_bitfld_comp_ref_p (lhs))
2874 lhs = build_ref_for_model (loc, lhs, 0, racc, gsi, false);
2875 gimple_assign_set_lhs (*stmt, lhs);
2877 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs))
2878 && !contains_vce_or_bfcref_p (rhs))
2879 rhs = build_ref_for_model (loc, rhs, 0, lacc, gsi, false);
2881 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
2883 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, TREE_TYPE (lhs),
2885 if (is_gimple_reg_type (TREE_TYPE (lhs))
2886 && TREE_CODE (lhs) != SSA_NAME)
2887 force_gimple_rhs = true;
2892 /* From this point on, the function deals with assignments in between
2893 aggregates when at least one has scalar reductions of some of its
2894 components. There are three possible scenarios: Both the LHS and RHS have
2895 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
2897 In the first case, we would like to load the LHS components from RHS
2898 components whenever possible. If that is not possible, we would like to
2899 read it directly from the RHS (after updating it by storing in it its own
2900 components). If there are some necessary unscalarized data in the LHS,
2901 those will be loaded by the original assignment too. If neither of these
2902 cases happen, the original statement can be removed. Most of this is done
2903 by load_assign_lhs_subreplacements.
2905 In the second case, we would like to store all RHS scalarized components
2906 directly into LHS and if they cover the aggregate completely, remove the
2907 statement too. In the third case, we want the LHS components to be loaded
2908 directly from the RHS (DSE will remove the original statement if it
2911 This is a bit complex but manageable when types match and when unions do
2912 not cause confusion in a way that we cannot really load a component of LHS
2913 from the RHS or vice versa (the access representing this level can have
2914 subaccesses that are accessible only through a different union field at a
2915 higher level - different from the one used in the examined expression).
2918 Therefore, I specially handle a fourth case, happening when there is a
2919 specific type cast or it is impossible to locate a scalarized subaccess on
2920 the other side of the expression. If that happens, I simply "refresh" the
2921 RHS by storing in it is scalarized components leave the original statement
2922 there to do the copying and then load the scalar replacements of the LHS.
2923 This is what the first branch does. */
2925 if (modify_this_stmt
2926 || gimple_has_volatile_ops (*stmt)
2927 || contains_vce_or_bfcref_p (rhs)
2928 || contains_vce_or_bfcref_p (lhs))
2930 if (access_has_children_p (racc))
2931 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
2932 gsi, false, false, loc);
2933 if (access_has_children_p (lacc))
2934 generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
2935 gsi, true, true, loc);
2936 sra_stats.separate_lhs_rhs_handling++;
2940 if (access_has_children_p (lacc)
2941 && access_has_children_p (racc)
2942 /* When an access represents an unscalarizable region, it usually
2943 represents accesses with variable offset and thus must not be used
2944 to generate new memory accesses. */
2945 && !lacc->grp_unscalarizable_region
2946 && !racc->grp_unscalarizable_region)
2948 gimple_stmt_iterator orig_gsi = *gsi;
2949 enum unscalarized_data_handling refreshed;
2951 if (lacc->grp_read && !lacc->grp_covered)
2952 refreshed = handle_unscalarized_data_in_subtree (racc, gsi);
2954 refreshed = SRA_UDH_NONE;
2956 load_assign_lhs_subreplacements (lacc, racc, lacc->offset,
2957 &orig_gsi, gsi, &refreshed);
2958 if (refreshed != SRA_UDH_RIGHT)
2961 unlink_stmt_vdef (*stmt);
2962 gsi_remove (&orig_gsi, true);
2963 sra_stats.deleted++;
2964 return SRA_AM_REMOVED;
2971 if (!racc->grp_to_be_replaced && !racc->grp_unscalarized_data)
2975 fprintf (dump_file, "Removing load: ");
2976 print_gimple_stmt (dump_file, *stmt, 0, 0);
2979 if (TREE_CODE (lhs) == SSA_NAME)
2981 rhs = get_repl_default_def_ssa_name (racc);
2982 if (!useless_type_conversion_p (TREE_TYPE (lhs),
2984 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR,
2985 TREE_TYPE (lhs), rhs);
2989 if (racc->first_child)
2990 generate_subtree_copies (racc->first_child, lhs,
2991 racc->offset, 0, 0, gsi,
2994 gcc_assert (*stmt == gsi_stmt (*gsi));
2995 unlink_stmt_vdef (*stmt);
2996 gsi_remove (gsi, true);
2997 sra_stats.deleted++;
2998 return SRA_AM_REMOVED;
3001 else if (racc->first_child)
3002 generate_subtree_copies (racc->first_child, lhs, racc->offset,
3003 0, 0, gsi, false, true, loc);
3005 if (access_has_children_p (lacc))
3006 generate_subtree_copies (lacc->first_child, rhs, lacc->offset,
3007 0, 0, gsi, true, true, loc);
3011 /* This gimplification must be done after generate_subtree_copies, lest we
3012 insert the subtree copies in the middle of the gimplified sequence. */
3013 if (force_gimple_rhs)
3014 rhs = force_gimple_operand_gsi (&orig_gsi, rhs, true, NULL_TREE,
3015 true, GSI_SAME_STMT);
3016 if (gimple_assign_rhs1 (*stmt) != rhs)
3018 modify_this_stmt = true;
3019 gimple_assign_set_rhs_from_tree (&orig_gsi, rhs);
3020 gcc_assert (*stmt == gsi_stmt (orig_gsi));
3023 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3026 /* Traverse the function body and all modifications as decided in
3027 analyze_all_variable_accesses. Return true iff the CFG has been
3031 sra_modify_function_body (void)
3033 bool cfg_changed = false;
3038 gimple_stmt_iterator gsi = gsi_start_bb (bb);
3039 while (!gsi_end_p (gsi))
3041 gimple stmt = gsi_stmt (gsi);
3042 enum assignment_mod_result assign_result;
3043 bool modified = false, deleted = false;
3047 switch (gimple_code (stmt))
3050 t = gimple_return_retval_ptr (stmt);
3051 if (*t != NULL_TREE)
3052 modified |= sra_modify_expr (t, &gsi, false);
3056 assign_result = sra_modify_assign (&stmt, &gsi);
3057 modified |= assign_result == SRA_AM_MODIFIED;
3058 deleted = assign_result == SRA_AM_REMOVED;
3062 /* Operands must be processed before the lhs. */
3063 for (i = 0; i < gimple_call_num_args (stmt); i++)
3065 t = gimple_call_arg_ptr (stmt, i);
3066 modified |= sra_modify_expr (t, &gsi, false);
3069 if (gimple_call_lhs (stmt))
3071 t = gimple_call_lhs_ptr (stmt);
3072 modified |= sra_modify_expr (t, &gsi, true);
3077 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
3079 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
3080 modified |= sra_modify_expr (t, &gsi, false);
3082 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
3084 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
3085 modified |= sra_modify_expr (t, &gsi, true);
3096 if (maybe_clean_eh_stmt (stmt)
3097 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
3108 /* Generate statements initializing scalar replacements of parts of function
3112 initialize_parameter_reductions (void)
3114 gimple_stmt_iterator gsi;
3115 gimple_seq seq = NULL;
3118 for (parm = DECL_ARGUMENTS (current_function_decl);
3120 parm = DECL_CHAIN (parm))
3122 VEC (access_p, heap) *access_vec;
3123 struct access *access;
3125 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3127 access_vec = get_base_access_vector (parm);
3133 seq = gimple_seq_alloc ();
3134 gsi = gsi_start (seq);
3137 for (access = VEC_index (access_p, access_vec, 0);
3139 access = access->next_grp)
3140 generate_subtree_copies (access, parm, 0, 0, 0, &gsi, true, true,
3141 EXPR_LOCATION (parm));
3145 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR), seq);
3148 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
3149 it reveals there are components of some aggregates to be scalarized, it runs
3150 the required transformations. */
3152 perform_intra_sra (void)
3157 if (!find_var_candidates ())
3160 if (!scan_function ())
3163 if (!analyze_all_variable_accesses ())
3166 if (sra_modify_function_body ())
3167 ret = TODO_update_ssa | TODO_cleanup_cfg;
3169 ret = TODO_update_ssa;
3170 initialize_parameter_reductions ();
3172 statistics_counter_event (cfun, "Scalar replacements created",
3173 sra_stats.replacements);
3174 statistics_counter_event (cfun, "Modified expressions", sra_stats.exprs);
3175 statistics_counter_event (cfun, "Subtree copy stmts",
3176 sra_stats.subtree_copies);
3177 statistics_counter_event (cfun, "Subreplacement stmts",
3178 sra_stats.subreplacements);
3179 statistics_counter_event (cfun, "Deleted stmts", sra_stats.deleted);
3180 statistics_counter_event (cfun, "Separate LHS and RHS handling",
3181 sra_stats.separate_lhs_rhs_handling);
3184 sra_deinitialize ();
3188 /* Perform early intraprocedural SRA. */
3190 early_intra_sra (void)
3192 sra_mode = SRA_MODE_EARLY_INTRA;
3193 return perform_intra_sra ();
3196 /* Perform "late" intraprocedural SRA. */
3198 late_intra_sra (void)
3200 sra_mode = SRA_MODE_INTRA;
3201 return perform_intra_sra ();
3206 gate_intra_sra (void)
3208 return flag_tree_sra != 0 && dbg_cnt (tree_sra);
3212 struct gimple_opt_pass pass_sra_early =
3217 gate_intra_sra, /* gate */
3218 early_intra_sra, /* execute */
3221 0, /* static_pass_number */
3222 TV_TREE_SRA, /* tv_id */
3223 PROP_cfg | PROP_ssa, /* properties_required */
3224 0, /* properties_provided */
3225 0, /* properties_destroyed */
3226 0, /* todo_flags_start */
3230 | TODO_verify_ssa /* todo_flags_finish */
3234 struct gimple_opt_pass pass_sra =
3239 gate_intra_sra, /* gate */
3240 late_intra_sra, /* execute */
3243 0, /* static_pass_number */
3244 TV_TREE_SRA, /* tv_id */
3245 PROP_cfg | PROP_ssa, /* properties_required */
3246 0, /* properties_provided */
3247 0, /* properties_destroyed */
3248 TODO_update_address_taken, /* todo_flags_start */
3252 | TODO_verify_ssa /* todo_flags_finish */
3257 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3261 is_unused_scalar_param (tree parm)
3264 return (is_gimple_reg (parm)
3265 && (!(name = gimple_default_def (cfun, parm))
3266 || has_zero_uses (name)));
3269 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3270 examine whether there are any direct or otherwise infeasible ones. If so,
3271 return true, otherwise return false. PARM must be a gimple register with a
3272 non-NULL default definition. */
3275 ptr_parm_has_direct_uses (tree parm)
3277 imm_use_iterator ui;
3279 tree name = gimple_default_def (cfun, parm);
3282 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
3285 use_operand_p use_p;
3287 if (is_gimple_debug (stmt))
3290 /* Valid uses include dereferences on the lhs and the rhs. */
3291 if (gimple_has_lhs (stmt))
3293 tree lhs = gimple_get_lhs (stmt);
3294 while (handled_component_p (lhs))
3295 lhs = TREE_OPERAND (lhs, 0);
3296 if (TREE_CODE (lhs) == MEM_REF
3297 && TREE_OPERAND (lhs, 0) == name
3298 && integer_zerop (TREE_OPERAND (lhs, 1))
3299 && types_compatible_p (TREE_TYPE (lhs),
3300 TREE_TYPE (TREE_TYPE (name)))
3301 && !TREE_THIS_VOLATILE (lhs))
3304 if (gimple_assign_single_p (stmt))
3306 tree rhs = gimple_assign_rhs1 (stmt);
3307 while (handled_component_p (rhs))
3308 rhs = TREE_OPERAND (rhs, 0);
3309 if (TREE_CODE (rhs) == MEM_REF
3310 && TREE_OPERAND (rhs, 0) == name
3311 && integer_zerop (TREE_OPERAND (rhs, 1))
3312 && types_compatible_p (TREE_TYPE (rhs),
3313 TREE_TYPE (TREE_TYPE (name)))
3314 && !TREE_THIS_VOLATILE (rhs))
3317 else if (is_gimple_call (stmt))
3320 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3322 tree arg = gimple_call_arg (stmt, i);
3323 while (handled_component_p (arg))
3324 arg = TREE_OPERAND (arg, 0);
3325 if (TREE_CODE (arg) == MEM_REF
3326 && TREE_OPERAND (arg, 0) == name
3327 && integer_zerop (TREE_OPERAND (arg, 1))
3328 && types_compatible_p (TREE_TYPE (arg),
3329 TREE_TYPE (TREE_TYPE (name)))
3330 && !TREE_THIS_VOLATILE (arg))
3335 /* If the number of valid uses does not match the number of
3336 uses in this stmt there is an unhandled use. */
3337 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
3344 BREAK_FROM_IMM_USE_STMT (ui);
3350 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3351 them in candidate_bitmap. Note that these do not necessarily include
3352 parameter which are unused and thus can be removed. Return true iff any
3353 such candidate has been found. */
3356 find_param_candidates (void)
3362 for (parm = DECL_ARGUMENTS (current_function_decl);
3364 parm = DECL_CHAIN (parm))
3366 tree type = TREE_TYPE (parm);
3370 if (TREE_THIS_VOLATILE (parm)
3371 || TREE_ADDRESSABLE (parm)
3372 || (!is_gimple_reg_type (type) && is_va_list_type (type)))
3375 if (is_unused_scalar_param (parm))
3381 if (POINTER_TYPE_P (type))
3383 type = TREE_TYPE (type);
3385 if (TREE_CODE (type) == FUNCTION_TYPE
3386 || TYPE_VOLATILE (type)
3387 || (TREE_CODE (type) == ARRAY_TYPE
3388 && TYPE_NONALIASED_COMPONENT (type))
3389 || !is_gimple_reg (parm)
3390 || is_va_list_type (type)
3391 || ptr_parm_has_direct_uses (parm))
3394 else if (!AGGREGATE_TYPE_P (type))
3397 if (!COMPLETE_TYPE_P (type)
3398 || !host_integerp (TYPE_SIZE (type), 1)
3399 || tree_low_cst (TYPE_SIZE (type), 1) == 0
3400 || (AGGREGATE_TYPE_P (type)
3401 && type_internals_preclude_sra_p (type)))
3404 bitmap_set_bit (candidate_bitmap, DECL_UID (parm));
3406 if (dump_file && (dump_flags & TDF_DETAILS))
3408 fprintf (dump_file, "Candidate (%d): ", DECL_UID (parm));
3409 print_generic_expr (dump_file, parm, 0);
3410 fprintf (dump_file, "\n");
3414 func_param_count = count;
3418 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3422 mark_maybe_modified (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef ATTRIBUTE_UNUSED,
3425 struct access *repr = (struct access *) data;
3427 repr->grp_maybe_modified = 1;
3431 /* Analyze what representatives (in linked lists accessible from
3432 REPRESENTATIVES) can be modified by side effects of statements in the
3433 current function. */
3436 analyze_modified_params (VEC (access_p, heap) *representatives)
3440 for (i = 0; i < func_param_count; i++)
3442 struct access *repr;
3444 for (repr = VEC_index (access_p, representatives, i);
3446 repr = repr->next_grp)
3448 struct access *access;
3452 if (no_accesses_p (repr))
3454 if (!POINTER_TYPE_P (TREE_TYPE (repr->base))
3455 || repr->grp_maybe_modified)
3458 ao_ref_init (&ar, repr->expr);
3459 visited = BITMAP_ALLOC (NULL);
3460 for (access = repr; access; access = access->next_sibling)
3462 /* All accesses are read ones, otherwise grp_maybe_modified would
3463 be trivially set. */
3464 walk_aliased_vdefs (&ar, gimple_vuse (access->stmt),
3465 mark_maybe_modified, repr, &visited);
3466 if (repr->grp_maybe_modified)
3469 BITMAP_FREE (visited);
3474 /* Propagate distances in bb_dereferences in the opposite direction than the
3475 control flow edges, in each step storing the maximum of the current value
3476 and the minimum of all successors. These steps are repeated until the table
3477 stabilizes. Note that BBs which might terminate the functions (according to
3478 final_bbs bitmap) never updated in this way. */
3481 propagate_dereference_distances (void)
3483 VEC (basic_block, heap) *queue;
3486 queue = VEC_alloc (basic_block, heap, last_basic_block_for_function (cfun));
3487 VEC_quick_push (basic_block, queue, ENTRY_BLOCK_PTR);
3490 VEC_quick_push (basic_block, queue, bb);
3494 while (!VEC_empty (basic_block, queue))
3498 bool change = false;
3501 bb = VEC_pop (basic_block, queue);
3504 if (bitmap_bit_p (final_bbs, bb->index))
3507 for (i = 0; i < func_param_count; i++)
3509 int idx = bb->index * func_param_count + i;
3511 HOST_WIDE_INT inh = 0;
3513 FOR_EACH_EDGE (e, ei, bb->succs)
3515 int succ_idx = e->dest->index * func_param_count + i;
3517 if (e->src == EXIT_BLOCK_PTR)
3523 inh = bb_dereferences [succ_idx];
3525 else if (bb_dereferences [succ_idx] < inh)
3526 inh = bb_dereferences [succ_idx];
3529 if (!first && bb_dereferences[idx] < inh)
3531 bb_dereferences[idx] = inh;
3536 if (change && !bitmap_bit_p (final_bbs, bb->index))
3537 FOR_EACH_EDGE (e, ei, bb->preds)
3542 e->src->aux = e->src;
3543 VEC_quick_push (basic_block, queue, e->src);
3547 VEC_free (basic_block, heap, queue);
3550 /* Dump a dereferences TABLE with heading STR to file F. */
3553 dump_dereferences_table (FILE *f, const char *str, HOST_WIDE_INT *table)
3557 fprintf (dump_file, str);
3558 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
3560 fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index));
3561 if (bb != EXIT_BLOCK_PTR)
3564 for (i = 0; i < func_param_count; i++)
3566 int idx = bb->index * func_param_count + i;
3567 fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", table[idx]);
3572 fprintf (dump_file, "\n");
3575 /* Determine what (parts of) parameters passed by reference that are not
3576 assigned to are not certainly dereferenced in this function and thus the
3577 dereferencing cannot be safely moved to the caller without potentially
3578 introducing a segfault. Mark such REPRESENTATIVES as
3579 grp_not_necessarilly_dereferenced.
3581 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3582 part is calculated rather than simple booleans are calculated for each
3583 pointer parameter to handle cases when only a fraction of the whole
3584 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3587 The maximum dereference distances for each pointer parameter and BB are
3588 already stored in bb_dereference. This routine simply propagates these
3589 values upwards by propagate_dereference_distances and then compares the
3590 distances of individual parameters in the ENTRY BB to the equivalent
3591 distances of each representative of a (fraction of a) parameter. */
3594 analyze_caller_dereference_legality (VEC (access_p, heap) *representatives)
3598 if (dump_file && (dump_flags & TDF_DETAILS))
3599 dump_dereferences_table (dump_file,
3600 "Dereference table before propagation:\n",
3603 propagate_dereference_distances ();
3605 if (dump_file && (dump_flags & TDF_DETAILS))
3606 dump_dereferences_table (dump_file,
3607 "Dereference table after propagation:\n",
3610 for (i = 0; i < func_param_count; i++)
3612 struct access *repr = VEC_index (access_p, representatives, i);
3613 int idx = ENTRY_BLOCK_PTR->index * func_param_count + i;
3615 if (!repr || no_accesses_p (repr))
3620 if ((repr->offset + repr->size) > bb_dereferences[idx])
3621 repr->grp_not_necessarilly_dereferenced = 1;
3622 repr = repr->next_grp;
3628 /* Return the representative access for the parameter declaration PARM if it is
3629 a scalar passed by reference which is not written to and the pointer value
3630 is not used directly. Thus, if it is legal to dereference it in the caller
3631 and we can rule out modifications through aliases, such parameter should be
3632 turned into one passed by value. Return NULL otherwise. */
3634 static struct access *
3635 unmodified_by_ref_scalar_representative (tree parm)
3637 int i, access_count;
3638 struct access *repr;
3639 VEC (access_p, heap) *access_vec;
3641 access_vec = get_base_access_vector (parm);
3642 gcc_assert (access_vec);
3643 repr = VEC_index (access_p, access_vec, 0);
3646 repr->group_representative = repr;
3648 access_count = VEC_length (access_p, access_vec);
3649 for (i = 1; i < access_count; i++)
3651 struct access *access = VEC_index (access_p, access_vec, i);
3654 access->group_representative = repr;
3655 access->next_sibling = repr->next_sibling;
3656 repr->next_sibling = access;
3660 repr->grp_scalar_ptr = 1;
3664 /* Return true iff this access precludes IPA-SRA of the parameter it is
3668 access_precludes_ipa_sra_p (struct access *access)
3670 /* Avoid issues such as the second simple testcase in PR 42025. The problem
3671 is incompatible assign in a call statement (and possibly even in asm
3672 statements). This can be relaxed by using a new temporary but only for
3673 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
3674 intraprocedural SRA we deal with this by keeping the old aggregate around,
3675 something we cannot do in IPA-SRA.) */
3677 && (is_gimple_call (access->stmt)
3678 || gimple_code (access->stmt) == GIMPLE_ASM))
3681 if (STRICT_ALIGNMENT
3682 && tree_non_aligned_mem_p (access->expr, TYPE_ALIGN (access->type)))
3689 /* Sort collected accesses for parameter PARM, identify representatives for
3690 each accessed region and link them together. Return NULL if there are
3691 different but overlapping accesses, return the special ptr value meaning
3692 there are no accesses for this parameter if that is the case and return the
3693 first representative otherwise. Set *RO_GRP if there is a group of accesses
3694 with only read (i.e. no write) accesses. */
3696 static struct access *
3697 splice_param_accesses (tree parm, bool *ro_grp)
3699 int i, j, access_count, group_count;
3700 int agg_size, total_size = 0;
3701 struct access *access, *res, **prev_acc_ptr = &res;
3702 VEC (access_p, heap) *access_vec;
3704 access_vec = get_base_access_vector (parm);
3706 return &no_accesses_representant;
3707 access_count = VEC_length (access_p, access_vec);
3709 VEC_qsort (access_p, access_vec, compare_access_positions);
3714 while (i < access_count)
3718 access = VEC_index (access_p, access_vec, i);
3719 modification = access->write;
3720 if (access_precludes_ipa_sra_p (access))
3722 a1_alias_type = reference_alias_ptr_type (access->expr);
3724 /* Access is about to become group representative unless we find some
3725 nasty overlap which would preclude us from breaking this parameter
3729 while (j < access_count)
3731 struct access *ac2 = VEC_index (access_p, access_vec, j);
3732 if (ac2->offset != access->offset)
3734 /* All or nothing law for parameters. */
3735 if (access->offset + access->size > ac2->offset)
3740 else if (ac2->size != access->size)
3743 if (access_precludes_ipa_sra_p (ac2)
3744 || (ac2->type != access->type
3745 && (TREE_ADDRESSABLE (ac2->type)
3746 || TREE_ADDRESSABLE (access->type)))
3747 || (reference_alias_ptr_type (ac2->expr) != a1_alias_type))
3750 modification |= ac2->write;
3751 ac2->group_representative = access;
3752 ac2->next_sibling = access->next_sibling;
3753 access->next_sibling = ac2;
3758 access->grp_maybe_modified = modification;
3761 *prev_acc_ptr = access;
3762 prev_acc_ptr = &access->next_grp;
3763 total_size += access->size;
3767 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3768 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3770 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3771 if (total_size >= agg_size)
3774 gcc_assert (group_count > 0);
3778 /* Decide whether parameters with representative accesses given by REPR should
3779 be reduced into components. */
3782 decide_one_param_reduction (struct access *repr)
3784 int total_size, cur_parm_size, agg_size, new_param_count, parm_size_limit;
3789 cur_parm_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (parm)), 1);
3790 gcc_assert (cur_parm_size > 0);
3792 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3795 agg_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))), 1);
3800 agg_size = cur_parm_size;
3806 fprintf (dump_file, "Evaluating PARAM group sizes for ");
3807 print_generic_expr (dump_file, parm, 0);
3808 fprintf (dump_file, " (UID: %u): \n", DECL_UID (parm));
3809 for (acc = repr; acc; acc = acc->next_grp)
3810 dump_access (dump_file, acc, true);
3814 new_param_count = 0;
3816 for (; repr; repr = repr->next_grp)
3818 gcc_assert (parm == repr->base);
3820 /* Taking the address of a non-addressable field is verboten. */
3821 if (by_ref && repr->non_addressable)
3824 if (!by_ref || (!repr->grp_maybe_modified
3825 && !repr->grp_not_necessarilly_dereferenced))
3826 total_size += repr->size;
3828 total_size += cur_parm_size;
3833 gcc_assert (new_param_count > 0);
3835 if (optimize_function_for_size_p (cfun))
3836 parm_size_limit = cur_parm_size;
3838 parm_size_limit = (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR)
3841 if (total_size < agg_size
3842 && total_size <= parm_size_limit)
3845 fprintf (dump_file, " ....will be split into %i components\n",
3847 return new_param_count;
3853 /* The order of the following enums is important, we need to do extra work for
3854 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
3855 enum ipa_splicing_result { NO_GOOD_ACCESS, UNUSED_PARAMS, BY_VAL_ACCESSES,
3856 MODIF_BY_REF_ACCESSES, UNMODIF_BY_REF_ACCESSES };
3858 /* Identify representatives of all accesses to all candidate parameters for
3859 IPA-SRA. Return result based on what representatives have been found. */
3861 static enum ipa_splicing_result
3862 splice_all_param_accesses (VEC (access_p, heap) **representatives)
3864 enum ipa_splicing_result result = NO_GOOD_ACCESS;
3866 struct access *repr;
3868 *representatives = VEC_alloc (access_p, heap, func_param_count);
3870 for (parm = DECL_ARGUMENTS (current_function_decl);
3872 parm = DECL_CHAIN (parm))
3874 if (is_unused_scalar_param (parm))
3876 VEC_quick_push (access_p, *representatives,
3877 &no_accesses_representant);
3878 if (result == NO_GOOD_ACCESS)
3879 result = UNUSED_PARAMS;
3881 else if (POINTER_TYPE_P (TREE_TYPE (parm))
3882 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm)))
3883 && bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3885 repr = unmodified_by_ref_scalar_representative (parm);
3886 VEC_quick_push (access_p, *representatives, repr);
3888 result = UNMODIF_BY_REF_ACCESSES;
3890 else if (bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3892 bool ro_grp = false;
3893 repr = splice_param_accesses (parm, &ro_grp);
3894 VEC_quick_push (access_p, *representatives, repr);
3896 if (repr && !no_accesses_p (repr))
3898 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3901 result = UNMODIF_BY_REF_ACCESSES;
3902 else if (result < MODIF_BY_REF_ACCESSES)
3903 result = MODIF_BY_REF_ACCESSES;
3905 else if (result < BY_VAL_ACCESSES)
3906 result = BY_VAL_ACCESSES;
3908 else if (no_accesses_p (repr) && (result == NO_GOOD_ACCESS))
3909 result = UNUSED_PARAMS;
3912 VEC_quick_push (access_p, *representatives, NULL);
3915 if (result == NO_GOOD_ACCESS)
3917 VEC_free (access_p, heap, *representatives);
3918 *representatives = NULL;
3919 return NO_GOOD_ACCESS;
3925 /* Return the index of BASE in PARMS. Abort if it is not found. */
3928 get_param_index (tree base, VEC(tree, heap) *parms)
3932 len = VEC_length (tree, parms);
3933 for (i = 0; i < len; i++)
3934 if (VEC_index (tree, parms, i) == base)
3939 /* Convert the decisions made at the representative level into compact
3940 parameter adjustments. REPRESENTATIVES are pointers to first
3941 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
3942 final number of adjustments. */
3944 static ipa_parm_adjustment_vec
3945 turn_representatives_into_adjustments (VEC (access_p, heap) *representatives,
3946 int adjustments_count)
3948 VEC (tree, heap) *parms;
3949 ipa_parm_adjustment_vec adjustments;
3953 gcc_assert (adjustments_count > 0);
3954 parms = ipa_get_vector_of_formal_parms (current_function_decl);
3955 adjustments = VEC_alloc (ipa_parm_adjustment_t, heap, adjustments_count);
3956 parm = DECL_ARGUMENTS (current_function_decl);
3957 for (i = 0; i < func_param_count; i++, parm = DECL_CHAIN (parm))
3959 struct access *repr = VEC_index (access_p, representatives, i);
3961 if (!repr || no_accesses_p (repr))
3963 struct ipa_parm_adjustment *adj;
3965 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
3966 memset (adj, 0, sizeof (*adj));
3967 adj->base_index = get_param_index (parm, parms);
3970 adj->copy_param = 1;
3972 adj->remove_param = 1;
3976 struct ipa_parm_adjustment *adj;
3977 int index = get_param_index (parm, parms);
3979 for (; repr; repr = repr->next_grp)
3981 adj = VEC_quick_push (ipa_parm_adjustment_t, adjustments, NULL);
3982 memset (adj, 0, sizeof (*adj));
3983 gcc_assert (repr->base == parm);
3984 adj->base_index = index;
3985 adj->base = repr->base;
3986 adj->type = repr->type;
3987 adj->alias_ptr_type = reference_alias_ptr_type (repr->expr);
3988 adj->offset = repr->offset;
3989 adj->by_ref = (POINTER_TYPE_P (TREE_TYPE (repr->base))
3990 && (repr->grp_maybe_modified
3991 || repr->grp_not_necessarilly_dereferenced));
3996 VEC_free (tree, heap, parms);
4000 /* Analyze the collected accesses and produce a plan what to do with the
4001 parameters in the form of adjustments, NULL meaning nothing. */
4003 static ipa_parm_adjustment_vec
4004 analyze_all_param_acesses (void)
4006 enum ipa_splicing_result repr_state;
4007 bool proceed = false;
4008 int i, adjustments_count = 0;
4009 VEC (access_p, heap) *representatives;
4010 ipa_parm_adjustment_vec adjustments;
4012 repr_state = splice_all_param_accesses (&representatives);
4013 if (repr_state == NO_GOOD_ACCESS)
4016 /* If there are any parameters passed by reference which are not modified
4017 directly, we need to check whether they can be modified indirectly. */
4018 if (repr_state == UNMODIF_BY_REF_ACCESSES)
4020 analyze_caller_dereference_legality (representatives);
4021 analyze_modified_params (representatives);
4024 for (i = 0; i < func_param_count; i++)
4026 struct access *repr = VEC_index (access_p, representatives, i);
4028 if (repr && !no_accesses_p (repr))
4030 if (repr->grp_scalar_ptr)
4032 adjustments_count++;
4033 if (repr->grp_not_necessarilly_dereferenced
4034 || repr->grp_maybe_modified)
4035 VEC_replace (access_p, representatives, i, NULL);
4039 sra_stats.scalar_by_ref_to_by_val++;
4044 int new_components = decide_one_param_reduction (repr);
4046 if (new_components == 0)
4048 VEC_replace (access_p, representatives, i, NULL);
4049 adjustments_count++;
4053 adjustments_count += new_components;
4054 sra_stats.aggregate_params_reduced++;
4055 sra_stats.param_reductions_created += new_components;
4062 if (no_accesses_p (repr))
4065 sra_stats.deleted_unused_parameters++;
4067 adjustments_count++;
4071 if (!proceed && dump_file)
4072 fprintf (dump_file, "NOT proceeding to change params.\n");
4075 adjustments = turn_representatives_into_adjustments (representatives,
4080 VEC_free (access_p, heap, representatives);
4084 /* If a parameter replacement identified by ADJ does not yet exist in the form
4085 of declaration, create it and record it, otherwise return the previously
4089 get_replaced_param_substitute (struct ipa_parm_adjustment *adj)
4092 if (!adj->new_ssa_base)
4094 char *pretty_name = make_fancy_name (adj->base);
4096 repl = create_tmp_reg (TREE_TYPE (adj->base), "ISR");
4097 DECL_NAME (repl) = get_identifier (pretty_name);
4098 obstack_free (&name_obstack, pretty_name);
4101 add_referenced_var (repl);
4102 adj->new_ssa_base = repl;
4105 repl = adj->new_ssa_base;
4109 /* Find the first adjustment for a particular parameter BASE in a vector of
4110 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
4113 static struct ipa_parm_adjustment *
4114 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments, tree base)
4118 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4119 for (i = 0; i < len; i++)
4121 struct ipa_parm_adjustment *adj;
4123 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4124 if (!adj->copy_param && adj->base == base)
4131 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
4132 removed because its value is not used, replace the SSA_NAME with a one
4133 relating to a created VAR_DECL together all of its uses and return true.
4134 ADJUSTMENTS is a pointer to an adjustments vector. */
4137 replace_removed_params_ssa_names (gimple stmt,
4138 ipa_parm_adjustment_vec adjustments)
4140 struct ipa_parm_adjustment *adj;
4141 tree lhs, decl, repl, name;
4143 if (gimple_code (stmt) == GIMPLE_PHI)
4144 lhs = gimple_phi_result (stmt);
4145 else if (is_gimple_assign (stmt))
4146 lhs = gimple_assign_lhs (stmt);
4147 else if (is_gimple_call (stmt))
4148 lhs = gimple_call_lhs (stmt);
4152 if (TREE_CODE (lhs) != SSA_NAME)
4154 decl = SSA_NAME_VAR (lhs);
4155 if (TREE_CODE (decl) != PARM_DECL)
4158 adj = get_adjustment_for_base (adjustments, decl);
4162 repl = get_replaced_param_substitute (adj);
4163 name = make_ssa_name (repl, stmt);
4167 fprintf (dump_file, "replacing an SSA name of a removed param ");
4168 print_generic_expr (dump_file, lhs, 0);
4169 fprintf (dump_file, " with ");
4170 print_generic_expr (dump_file, name, 0);
4171 fprintf (dump_file, "\n");
4174 if (is_gimple_assign (stmt))
4175 gimple_assign_set_lhs (stmt, name);
4176 else if (is_gimple_call (stmt))
4177 gimple_call_set_lhs (stmt, name);
4179 gimple_phi_set_result (stmt, name);
4181 replace_uses_by (lhs, name);
4182 release_ssa_name (lhs);
4186 /* If the expression *EXPR should be replaced by a reduction of a parameter, do
4187 so. ADJUSTMENTS is a pointer to a vector of adjustments. CONVERT
4188 specifies whether the function should care about type incompatibility the
4189 current and new expressions. If it is false, the function will leave
4190 incompatibility issues to the caller. Return true iff the expression
4194 sra_ipa_modify_expr (tree *expr, bool convert,
4195 ipa_parm_adjustment_vec adjustments)
4198 struct ipa_parm_adjustment *adj, *cand = NULL;
4199 HOST_WIDE_INT offset, size, max_size;
4202 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4204 if (TREE_CODE (*expr) == BIT_FIELD_REF
4205 || TREE_CODE (*expr) == IMAGPART_EXPR
4206 || TREE_CODE (*expr) == REALPART_EXPR)
4208 expr = &TREE_OPERAND (*expr, 0);
4212 base = get_ref_base_and_extent (*expr, &offset, &size, &max_size);
4213 if (!base || size == -1 || max_size == -1)
4216 if (TREE_CODE (base) == MEM_REF)
4218 offset += mem_ref_offset (base).low * BITS_PER_UNIT;
4219 base = TREE_OPERAND (base, 0);
4222 base = get_ssa_base_param (base);
4223 if (!base || TREE_CODE (base) != PARM_DECL)
4226 for (i = 0; i < len; i++)
4228 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4230 if (adj->base == base &&
4231 (adj->offset == offset || adj->remove_param))
4237 if (!cand || cand->copy_param || cand->remove_param)
4241 src = build_simple_mem_ref (cand->reduction);
4243 src = cand->reduction;
4245 if (dump_file && (dump_flags & TDF_DETAILS))
4247 fprintf (dump_file, "About to replace expr ");
4248 print_generic_expr (dump_file, *expr, 0);
4249 fprintf (dump_file, " with ");
4250 print_generic_expr (dump_file, src, 0);
4251 fprintf (dump_file, "\n");
4254 if (convert && !useless_type_conversion_p (TREE_TYPE (*expr), cand->type))
4256 tree vce = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (*expr), src);
4264 /* If the statement pointed to by STMT_PTR contains any expressions that need
4265 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4266 potential type incompatibilities (GSI is used to accommodate conversion
4267 statements and must point to the statement). Return true iff the statement
4271 sra_ipa_modify_assign (gimple *stmt_ptr, gimple_stmt_iterator *gsi,
4272 ipa_parm_adjustment_vec adjustments)
4274 gimple stmt = *stmt_ptr;
4275 tree *lhs_p, *rhs_p;
4278 if (!gimple_assign_single_p (stmt))
4281 rhs_p = gimple_assign_rhs1_ptr (stmt);
4282 lhs_p = gimple_assign_lhs_ptr (stmt);
4284 any = sra_ipa_modify_expr (rhs_p, false, adjustments);
4285 any |= sra_ipa_modify_expr (lhs_p, false, adjustments);
4288 tree new_rhs = NULL_TREE;
4290 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p), TREE_TYPE (*rhs_p)))
4292 if (TREE_CODE (*rhs_p) == CONSTRUCTOR)
4294 /* V_C_Es of constructors can cause trouble (PR 42714). */
4295 if (is_gimple_reg_type (TREE_TYPE (*lhs_p)))
4296 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
4298 *rhs_p = build_constructor (TREE_TYPE (*lhs_p), 0);
4301 new_rhs = fold_build1_loc (gimple_location (stmt),
4302 VIEW_CONVERT_EXPR, TREE_TYPE (*lhs_p),
4305 else if (REFERENCE_CLASS_P (*rhs_p)
4306 && is_gimple_reg_type (TREE_TYPE (*lhs_p))
4307 && !is_gimple_reg (*lhs_p))
4308 /* This can happen when an assignment in between two single field
4309 structures is turned into an assignment in between two pointers to
4310 scalars (PR 42237). */
4315 tree tmp = force_gimple_operand_gsi (gsi, new_rhs, true, NULL_TREE,
4316 true, GSI_SAME_STMT);
4318 gimple_assign_set_rhs_from_tree (gsi, tmp);
4327 /* Traverse the function body and all modifications as described in
4328 ADJUSTMENTS. Return true iff the CFG has been changed. */
4331 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments)
4333 bool cfg_changed = false;
4338 gimple_stmt_iterator gsi;
4340 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4341 replace_removed_params_ssa_names (gsi_stmt (gsi), adjustments);
4343 gsi = gsi_start_bb (bb);
4344 while (!gsi_end_p (gsi))
4346 gimple stmt = gsi_stmt (gsi);
4347 bool modified = false;
4351 switch (gimple_code (stmt))
4354 t = gimple_return_retval_ptr (stmt);
4355 if (*t != NULL_TREE)
4356 modified |= sra_ipa_modify_expr (t, true, adjustments);
4360 modified |= sra_ipa_modify_assign (&stmt, &gsi, adjustments);
4361 modified |= replace_removed_params_ssa_names (stmt, adjustments);
4365 /* Operands must be processed before the lhs. */
4366 for (i = 0; i < gimple_call_num_args (stmt); i++)
4368 t = gimple_call_arg_ptr (stmt, i);
4369 modified |= sra_ipa_modify_expr (t, true, adjustments);
4372 if (gimple_call_lhs (stmt))
4374 t = gimple_call_lhs_ptr (stmt);
4375 modified |= sra_ipa_modify_expr (t, false, adjustments);
4376 modified |= replace_removed_params_ssa_names (stmt,
4382 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
4384 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
4385 modified |= sra_ipa_modify_expr (t, true, adjustments);
4387 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
4389 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
4390 modified |= sra_ipa_modify_expr (t, false, adjustments);
4401 if (maybe_clean_eh_stmt (stmt)
4402 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
4412 /* Call gimple_debug_bind_reset_value on all debug statements describing
4413 gimple register parameters that are being removed or replaced. */
4416 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments)
4420 len = VEC_length (ipa_parm_adjustment_t, adjustments);
4421 for (i = 0; i < len; i++)
4423 struct ipa_parm_adjustment *adj;
4424 imm_use_iterator ui;
4428 adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
4429 if (adj->copy_param || !is_gimple_reg (adj->base))
4431 name = gimple_default_def (cfun, adj->base);
4434 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
4436 /* All other users must have been removed by
4437 ipa_sra_modify_function_body. */
4438 gcc_assert (is_gimple_debug (stmt));
4439 gimple_debug_bind_reset_value (stmt);
4445 /* Return true iff all callers have at least as many actual arguments as there
4446 are formal parameters in the current function. */
4449 all_callers_have_enough_arguments_p (struct cgraph_node *node)
4451 struct cgraph_edge *cs;
4452 for (cs = node->callers; cs; cs = cs->next_caller)
4453 if (!callsite_has_enough_arguments_p (cs->call_stmt))
4460 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4463 convert_callers (struct cgraph_node *node, tree old_decl,
4464 ipa_parm_adjustment_vec adjustments)
4466 tree old_cur_fndecl = current_function_decl;
4467 struct cgraph_edge *cs;
4468 basic_block this_block;
4469 bitmap recomputed_callers = BITMAP_ALLOC (NULL);
4471 for (cs = node->callers; cs; cs = cs->next_caller)
4473 current_function_decl = cs->caller->decl;
4474 push_cfun (DECL_STRUCT_FUNCTION (cs->caller->decl));
4477 fprintf (dump_file, "Adjusting call (%i -> %i) %s -> %s\n",
4478 cs->caller->uid, cs->callee->uid,
4479 cgraph_node_name (cs->caller),
4480 cgraph_node_name (cs->callee));
4482 ipa_modify_call_arguments (cs, cs->call_stmt, adjustments);
4487 for (cs = node->callers; cs; cs = cs->next_caller)
4488 if (bitmap_set_bit (recomputed_callers, cs->caller->uid)
4489 && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (cs->caller->decl)))
4490 compute_inline_parameters (cs->caller);
4491 BITMAP_FREE (recomputed_callers);
4493 current_function_decl = old_cur_fndecl;
4495 if (!encountered_recursive_call)
4498 FOR_EACH_BB (this_block)
4500 gimple_stmt_iterator gsi;
4502 for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
4504 gimple stmt = gsi_stmt (gsi);
4506 if (gimple_code (stmt) != GIMPLE_CALL)
4508 call_fndecl = gimple_call_fndecl (stmt);
4509 if (call_fndecl == old_decl)
4512 fprintf (dump_file, "Adjusting recursive call");
4513 gimple_call_set_fndecl (stmt, node->decl);
4514 ipa_modify_call_arguments (NULL, stmt, adjustments);
4522 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4523 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4526 modify_function (struct cgraph_node *node, ipa_parm_adjustment_vec adjustments)
4528 struct cgraph_node *new_node;
4529 struct cgraph_edge *cs;
4531 VEC (cgraph_edge_p, heap) * redirect_callers;
4535 for (cs = node->callers; cs != NULL; cs = cs->next_caller)
4537 redirect_callers = VEC_alloc (cgraph_edge_p, heap, node_callers);
4538 for (cs = node->callers; cs != NULL; cs = cs->next_caller)
4539 VEC_quick_push (cgraph_edge_p, redirect_callers, cs);
4541 rebuild_cgraph_edges ();
4543 current_function_decl = NULL_TREE;
4545 new_node = cgraph_function_versioning (node, redirect_callers, NULL, NULL,
4546 NULL, NULL, "isra");
4547 current_function_decl = new_node->decl;
4548 push_cfun (DECL_STRUCT_FUNCTION (new_node->decl));
4550 ipa_modify_formal_parameters (current_function_decl, adjustments, "ISRA");
4551 cfg_changed = ipa_sra_modify_function_body (adjustments);
4552 sra_ipa_reset_debug_stmts (adjustments);
4553 convert_callers (new_node, node->decl, adjustments);
4554 cgraph_make_node_local (new_node);
4558 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4559 attributes, return true otherwise. NODE is the cgraph node of the current
4563 ipa_sra_preliminary_function_checks (struct cgraph_node *node)
4565 if (!cgraph_node_can_be_local_p (node))
4568 fprintf (dump_file, "Function not local to this compilation unit.\n");
4572 if (!node->local.can_change_signature)
4575 fprintf (dump_file, "Function can not change signature.\n");
4579 if (!tree_versionable_function_p (node->decl))
4582 fprintf (dump_file, "Function is not versionable.\n");
4586 if (DECL_VIRTUAL_P (current_function_decl))
4589 fprintf (dump_file, "Function is a virtual method.\n");
4593 if ((DECL_COMDAT (node->decl) || DECL_EXTERNAL (node->decl))
4594 && node->global.size >= MAX_INLINE_INSNS_AUTO)
4597 fprintf (dump_file, "Function too big to be made truly local.\n");
4605 "Function has no callers in this compilation unit.\n");
4612 fprintf (dump_file, "Function uses stdarg. \n");
4616 if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl)))
4622 /* Perform early interprocedural SRA. */
4625 ipa_early_sra (void)
4627 struct cgraph_node *node = cgraph_node (current_function_decl);
4628 ipa_parm_adjustment_vec adjustments;
4631 if (!ipa_sra_preliminary_function_checks (node))
4635 sra_mode = SRA_MODE_EARLY_IPA;
4637 if (!find_param_candidates ())
4640 fprintf (dump_file, "Function has no IPA-SRA candidates.\n");
4644 if (!all_callers_have_enough_arguments_p (node))
4647 fprintf (dump_file, "There are callers with insufficient number of "
4652 bb_dereferences = XCNEWVEC (HOST_WIDE_INT,
4654 * last_basic_block_for_function (cfun));
4655 final_bbs = BITMAP_ALLOC (NULL);
4658 if (encountered_apply_args)
4661 fprintf (dump_file, "Function calls __builtin_apply_args().\n");
4665 if (encountered_unchangable_recursive_call)
4668 fprintf (dump_file, "Function calls itself with insufficient "
4669 "number of arguments.\n");
4673 adjustments = analyze_all_param_acesses ();
4677 ipa_dump_param_adjustments (dump_file, adjustments, current_function_decl);
4679 if (modify_function (node, adjustments))
4680 ret = TODO_update_ssa | TODO_cleanup_cfg;
4682 ret = TODO_update_ssa;
4683 VEC_free (ipa_parm_adjustment_t, heap, adjustments);
4685 statistics_counter_event (cfun, "Unused parameters deleted",
4686 sra_stats.deleted_unused_parameters);
4687 statistics_counter_event (cfun, "Scalar parameters converted to by-value",
4688 sra_stats.scalar_by_ref_to_by_val);
4689 statistics_counter_event (cfun, "Aggregate parameters broken up",
4690 sra_stats.aggregate_params_reduced);
4691 statistics_counter_event (cfun, "Aggregate parameter components created",
4692 sra_stats.param_reductions_created);
4695 BITMAP_FREE (final_bbs);
4696 free (bb_dereferences);
4698 sra_deinitialize ();
4702 /* Return if early ipa sra shall be performed. */
4704 ipa_early_sra_gate (void)
4706 return flag_ipa_sra && dbg_cnt (eipa_sra);
4709 struct gimple_opt_pass pass_early_ipa_sra =
4713 "eipa_sra", /* name */
4714 ipa_early_sra_gate, /* gate */
4715 ipa_early_sra, /* execute */
4718 0, /* static_pass_number */
4719 TV_IPA_SRA, /* tv_id */
4720 0, /* properties_required */
4721 0, /* properties_provided */
4722 0, /* properties_destroyed */
4723 0, /* todo_flags_start */
4724 TODO_dump_func | TODO_dump_cgraph /* todo_flags_finish */