Daily bump.
[official-gcc.git] / gcc / tree-sra.c
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1 /* Scalar Replacement of Aggregates (SRA) converts some structure
2 references into scalar references, exposing them to the scalar
3 optimizers.
4 Copyright (C) 2008-2014 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
12 version.
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
17 for more details.
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
31 conversions.
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
49 accesses.
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. */
74 #include "config.h"
75 #include "system.h"
76 #include "coretypes.h"
77 #include "hash-table.h"
78 #include "alloc-pool.h"
79 #include "tm.h"
80 #include "tree.h"
81 #include "pointer-set.h"
82 #include "basic-block.h"
83 #include "tree-ssa-alias.h"
84 #include "internal-fn.h"
85 #include "tree-eh.h"
86 #include "gimple-expr.h"
87 #include "is-a.h"
88 #include "gimple.h"
89 #include "stor-layout.h"
90 #include "gimplify.h"
91 #include "gimple-iterator.h"
92 #include "gimplify-me.h"
93 #include "gimple-walk.h"
94 #include "bitmap.h"
95 #include "gimple-ssa.h"
96 #include "tree-cfg.h"
97 #include "tree-phinodes.h"
98 #include "ssa-iterators.h"
99 #include "stringpool.h"
100 #include "tree-ssanames.h"
101 #include "expr.h"
102 #include "tree-dfa.h"
103 #include "tree-ssa.h"
104 #include "tree-pass.h"
105 #include "ipa-prop.h"
106 #include "statistics.h"
107 #include "params.h"
108 #include "target.h"
109 #include "flags.h"
110 #include "dbgcnt.h"
111 #include "tree-inline.h"
112 #include "gimple-pretty-print.h"
113 #include "ipa-inline.h"
114 #include "ipa-utils.h"
116 /* Enumeration of all aggregate reductions we can do. */
117 enum sra_mode { SRA_MODE_EARLY_IPA, /* early call regularization */
118 SRA_MODE_EARLY_INTRA, /* early intraprocedural SRA */
119 SRA_MODE_INTRA }; /* late intraprocedural SRA */
121 /* Global variable describing which aggregate reduction we are performing at
122 the moment. */
123 static enum sra_mode sra_mode;
125 struct assign_link;
127 /* ACCESS represents each access to an aggregate variable (as a whole or a
128 part). It can also represent a group of accesses that refer to exactly the
129 same fragment of an aggregate (i.e. those that have exactly the same offset
130 and size). Such representatives for a single aggregate, once determined,
131 are linked in a linked list and have the group fields set.
133 Moreover, when doing intraprocedural SRA, a tree is built from those
134 representatives (by the means of first_child and next_sibling pointers), in
135 which all items in a subtree are "within" the root, i.e. their offset is
136 greater or equal to offset of the root and offset+size is smaller or equal
137 to offset+size of the root. Children of an access are sorted by offset.
139 Note that accesses to parts of vector and complex number types always
140 represented by an access to the whole complex number or a vector. It is a
141 duty of the modifying functions to replace them appropriately. */
143 struct access
145 /* Values returned by `get_ref_base_and_extent' for each component reference
146 If EXPR isn't a component reference just set `BASE = EXPR', `OFFSET = 0',
147 `SIZE = TREE_SIZE (TREE_TYPE (expr))'. */
148 HOST_WIDE_INT offset;
149 HOST_WIDE_INT size;
150 tree base;
152 /* Expression. It is context dependent so do not use it to create new
153 expressions to access the original aggregate. See PR 42154 for a
154 testcase. */
155 tree expr;
156 /* Type. */
157 tree type;
159 /* The statement this access belongs to. */
160 gimple stmt;
162 /* Next group representative for this aggregate. */
163 struct access *next_grp;
165 /* Pointer to the group representative. Pointer to itself if the struct is
166 the representative. */
167 struct access *group_representative;
169 /* If this access has any children (in terms of the definition above), this
170 points to the first one. */
171 struct access *first_child;
173 /* In intraprocedural SRA, pointer to the next sibling in the access tree as
174 described above. In IPA-SRA this is a pointer to the next access
175 belonging to the same group (having the same representative). */
176 struct access *next_sibling;
178 /* Pointers to the first and last element in the linked list of assign
179 links. */
180 struct assign_link *first_link, *last_link;
182 /* Pointer to the next access in the work queue. */
183 struct access *next_queued;
185 /* Replacement variable for this access "region." Never to be accessed
186 directly, always only by the means of get_access_replacement() and only
187 when grp_to_be_replaced flag is set. */
188 tree replacement_decl;
190 /* Is this particular access write access? */
191 unsigned write : 1;
193 /* Is this access an access to a non-addressable field? */
194 unsigned non_addressable : 1;
196 /* Is this access currently in the work queue? */
197 unsigned grp_queued : 1;
199 /* Does this group contain a write access? This flag is propagated down the
200 access tree. */
201 unsigned grp_write : 1;
203 /* Does this group contain a read access? This flag is propagated down the
204 access tree. */
205 unsigned grp_read : 1;
207 /* Does this group contain a read access that comes from an assignment
208 statement? This flag is propagated down the access tree. */
209 unsigned grp_assignment_read : 1;
211 /* Does this group contain a write access that comes from an assignment
212 statement? This flag is propagated down the access tree. */
213 unsigned grp_assignment_write : 1;
215 /* Does this group contain a read access through a scalar type? This flag is
216 not propagated in the access tree in any direction. */
217 unsigned grp_scalar_read : 1;
219 /* Does this group contain a write access through a scalar type? This flag
220 is not propagated in the access tree in any direction. */
221 unsigned grp_scalar_write : 1;
223 /* Is this access an artificial one created to scalarize some record
224 entirely? */
225 unsigned grp_total_scalarization : 1;
227 /* Other passes of the analysis use this bit to make function
228 analyze_access_subtree create scalar replacements for this group if
229 possible. */
230 unsigned grp_hint : 1;
232 /* Is the subtree rooted in this access fully covered by scalar
233 replacements? */
234 unsigned grp_covered : 1;
236 /* If set to true, this access and all below it in an access tree must not be
237 scalarized. */
238 unsigned grp_unscalarizable_region : 1;
240 /* Whether data have been written to parts of the aggregate covered by this
241 access which is not to be scalarized. This flag is propagated up in the
242 access tree. */
243 unsigned grp_unscalarized_data : 1;
245 /* Does this access and/or group contain a write access through a
246 BIT_FIELD_REF? */
247 unsigned grp_partial_lhs : 1;
249 /* Set when a scalar replacement should be created for this variable. */
250 unsigned grp_to_be_replaced : 1;
252 /* Set when we want a replacement for the sole purpose of having it in
253 generated debug statements. */
254 unsigned grp_to_be_debug_replaced : 1;
256 /* Should TREE_NO_WARNING of a replacement be set? */
257 unsigned grp_no_warning : 1;
259 /* Is it possible that the group refers to data which might be (directly or
260 otherwise) modified? */
261 unsigned grp_maybe_modified : 1;
263 /* Set when this is a representative of a pointer to scalar (i.e. by
264 reference) parameter which we consider for turning into a plain scalar
265 (i.e. a by value parameter). */
266 unsigned grp_scalar_ptr : 1;
268 /* Set when we discover that this pointer is not safe to dereference in the
269 caller. */
270 unsigned grp_not_necessarilly_dereferenced : 1;
273 typedef struct access *access_p;
276 /* Alloc pool for allocating access structures. */
277 static alloc_pool access_pool;
279 /* A structure linking lhs and rhs accesses from an aggregate assignment. They
280 are used to propagate subaccesses from rhs to lhs as long as they don't
281 conflict with what is already there. */
282 struct assign_link
284 struct access *lacc, *racc;
285 struct assign_link *next;
288 /* Alloc pool for allocating assign link structures. */
289 static alloc_pool link_pool;
291 /* Base (tree) -> Vector (vec<access_p> *) map. */
292 static struct pointer_map_t *base_access_vec;
294 /* Candidate hash table helpers. */
296 struct uid_decl_hasher : typed_noop_remove <tree_node>
298 typedef tree_node value_type;
299 typedef tree_node compare_type;
300 static inline hashval_t hash (const value_type *);
301 static inline bool equal (const value_type *, const compare_type *);
304 /* Hash a tree in a uid_decl_map. */
306 inline hashval_t
307 uid_decl_hasher::hash (const value_type *item)
309 return item->decl_minimal.uid;
312 /* Return true if the DECL_UID in both trees are equal. */
314 inline bool
315 uid_decl_hasher::equal (const value_type *a, const compare_type *b)
317 return (a->decl_minimal.uid == b->decl_minimal.uid);
320 /* Set of candidates. */
321 static bitmap candidate_bitmap;
322 static hash_table <uid_decl_hasher> candidates;
324 /* For a candidate UID return the candidates decl. */
326 static inline tree
327 candidate (unsigned uid)
329 tree_node t;
330 t.decl_minimal.uid = uid;
331 return candidates.find_with_hash (&t, static_cast <hashval_t> (uid));
334 /* Bitmap of candidates which we should try to entirely scalarize away and
335 those which cannot be (because they are and need be used as a whole). */
336 static bitmap should_scalarize_away_bitmap, cannot_scalarize_away_bitmap;
338 /* Obstack for creation of fancy names. */
339 static struct obstack name_obstack;
341 /* Head of a linked list of accesses that need to have its subaccesses
342 propagated to their assignment counterparts. */
343 static struct access *work_queue_head;
345 /* Number of parameters of the analyzed function when doing early ipa SRA. */
346 static int func_param_count;
348 /* scan_function sets the following to true if it encounters a call to
349 __builtin_apply_args. */
350 static bool encountered_apply_args;
352 /* Set by scan_function when it finds a recursive call. */
353 static bool encountered_recursive_call;
355 /* Set by scan_function when it finds a recursive call with less actual
356 arguments than formal parameters.. */
357 static bool encountered_unchangable_recursive_call;
359 /* This is a table in which for each basic block and parameter there is a
360 distance (offset + size) in that parameter which is dereferenced and
361 accessed in that BB. */
362 static HOST_WIDE_INT *bb_dereferences;
363 /* Bitmap of BBs that can cause the function to "stop" progressing by
364 returning, throwing externally, looping infinitely or calling a function
365 which might abort etc.. */
366 static bitmap final_bbs;
368 /* Representative of no accesses at all. */
369 static struct access no_accesses_representant;
371 /* Predicate to test the special value. */
373 static inline bool
374 no_accesses_p (struct access *access)
376 return access == &no_accesses_representant;
379 /* Dump contents of ACCESS to file F in a human friendly way. If GRP is true,
380 representative fields are dumped, otherwise those which only describe the
381 individual access are. */
383 static struct
385 /* Number of processed aggregates is readily available in
386 analyze_all_variable_accesses and so is not stored here. */
388 /* Number of created scalar replacements. */
389 int replacements;
391 /* Number of times sra_modify_expr or sra_modify_assign themselves changed an
392 expression. */
393 int exprs;
395 /* Number of statements created by generate_subtree_copies. */
396 int subtree_copies;
398 /* Number of statements created by load_assign_lhs_subreplacements. */
399 int subreplacements;
401 /* Number of times sra_modify_assign has deleted a statement. */
402 int deleted;
404 /* Number of times sra_modify_assign has to deal with subaccesses of LHS and
405 RHS reparately due to type conversions or nonexistent matching
406 references. */
407 int separate_lhs_rhs_handling;
409 /* Number of parameters that were removed because they were unused. */
410 int deleted_unused_parameters;
412 /* Number of scalars passed as parameters by reference that have been
413 converted to be passed by value. */
414 int scalar_by_ref_to_by_val;
416 /* Number of aggregate parameters that were replaced by one or more of their
417 components. */
418 int aggregate_params_reduced;
420 /* Numbber of components created when splitting aggregate parameters. */
421 int param_reductions_created;
422 } sra_stats;
424 static void
425 dump_access (FILE *f, struct access *access, bool grp)
427 fprintf (f, "access { ");
428 fprintf (f, "base = (%d)'", DECL_UID (access->base));
429 print_generic_expr (f, access->base, 0);
430 fprintf (f, "', offset = " HOST_WIDE_INT_PRINT_DEC, access->offset);
431 fprintf (f, ", size = " HOST_WIDE_INT_PRINT_DEC, access->size);
432 fprintf (f, ", expr = ");
433 print_generic_expr (f, access->expr, 0);
434 fprintf (f, ", type = ");
435 print_generic_expr (f, access->type, 0);
436 if (grp)
437 fprintf (f, ", grp_read = %d, grp_write = %d, grp_assignment_read = %d, "
438 "grp_assignment_write = %d, grp_scalar_read = %d, "
439 "grp_scalar_write = %d, grp_total_scalarization = %d, "
440 "grp_hint = %d, grp_covered = %d, "
441 "grp_unscalarizable_region = %d, grp_unscalarized_data = %d, "
442 "grp_partial_lhs = %d, grp_to_be_replaced = %d, "
443 "grp_to_be_debug_replaced = %d, grp_maybe_modified = %d, "
444 "grp_not_necessarilly_dereferenced = %d\n",
445 access->grp_read, access->grp_write, access->grp_assignment_read,
446 access->grp_assignment_write, access->grp_scalar_read,
447 access->grp_scalar_write, access->grp_total_scalarization,
448 access->grp_hint, access->grp_covered,
449 access->grp_unscalarizable_region, access->grp_unscalarized_data,
450 access->grp_partial_lhs, access->grp_to_be_replaced,
451 access->grp_to_be_debug_replaced, access->grp_maybe_modified,
452 access->grp_not_necessarilly_dereferenced);
453 else
454 fprintf (f, ", write = %d, grp_total_scalarization = %d, "
455 "grp_partial_lhs = %d\n",
456 access->write, access->grp_total_scalarization,
457 access->grp_partial_lhs);
460 /* Dump a subtree rooted in ACCESS to file F, indent by LEVEL. */
462 static void
463 dump_access_tree_1 (FILE *f, struct access *access, int level)
467 int i;
469 for (i = 0; i < level; i++)
470 fputs ("* ", dump_file);
472 dump_access (f, access, true);
474 if (access->first_child)
475 dump_access_tree_1 (f, access->first_child, level + 1);
477 access = access->next_sibling;
479 while (access);
482 /* Dump all access trees for a variable, given the pointer to the first root in
483 ACCESS. */
485 static void
486 dump_access_tree (FILE *f, struct access *access)
488 for (; access; access = access->next_grp)
489 dump_access_tree_1 (f, access, 0);
492 /* Return true iff ACC is non-NULL and has subaccesses. */
494 static inline bool
495 access_has_children_p (struct access *acc)
497 return acc && acc->first_child;
500 /* Return true iff ACC is (partly) covered by at least one replacement. */
502 static bool
503 access_has_replacements_p (struct access *acc)
505 struct access *child;
506 if (acc->grp_to_be_replaced)
507 return true;
508 for (child = acc->first_child; child; child = child->next_sibling)
509 if (access_has_replacements_p (child))
510 return true;
511 return false;
514 /* Return a vector of pointers to accesses for the variable given in BASE or
515 NULL if there is none. */
517 static vec<access_p> *
518 get_base_access_vector (tree base)
520 void **slot;
522 slot = pointer_map_contains (base_access_vec, base);
523 if (!slot)
524 return NULL;
525 else
526 return *(vec<access_p> **) slot;
529 /* Find an access with required OFFSET and SIZE in a subtree of accesses rooted
530 in ACCESS. Return NULL if it cannot be found. */
532 static struct access *
533 find_access_in_subtree (struct access *access, HOST_WIDE_INT offset,
534 HOST_WIDE_INT size)
536 while (access && (access->offset != offset || access->size != size))
538 struct access *child = access->first_child;
540 while (child && (child->offset + child->size <= offset))
541 child = child->next_sibling;
542 access = child;
545 return access;
548 /* Return the first group representative for DECL or NULL if none exists. */
550 static struct access *
551 get_first_repr_for_decl (tree base)
553 vec<access_p> *access_vec;
555 access_vec = get_base_access_vector (base);
556 if (!access_vec)
557 return NULL;
559 return (*access_vec)[0];
562 /* Find an access representative for the variable BASE and given OFFSET and
563 SIZE. Requires that access trees have already been built. Return NULL if
564 it cannot be found. */
566 static struct access *
567 get_var_base_offset_size_access (tree base, HOST_WIDE_INT offset,
568 HOST_WIDE_INT size)
570 struct access *access;
572 access = get_first_repr_for_decl (base);
573 while (access && (access->offset + access->size <= offset))
574 access = access->next_grp;
575 if (!access)
576 return NULL;
578 return find_access_in_subtree (access, offset, size);
581 /* Add LINK to the linked list of assign links of RACC. */
582 static void
583 add_link_to_rhs (struct access *racc, struct assign_link *link)
585 gcc_assert (link->racc == racc);
587 if (!racc->first_link)
589 gcc_assert (!racc->last_link);
590 racc->first_link = link;
592 else
593 racc->last_link->next = link;
595 racc->last_link = link;
596 link->next = NULL;
599 /* Move all link structures in their linked list in OLD_RACC to the linked list
600 in NEW_RACC. */
601 static void
602 relink_to_new_repr (struct access *new_racc, struct access *old_racc)
604 if (!old_racc->first_link)
606 gcc_assert (!old_racc->last_link);
607 return;
610 if (new_racc->first_link)
612 gcc_assert (!new_racc->last_link->next);
613 gcc_assert (!old_racc->last_link || !old_racc->last_link->next);
615 new_racc->last_link->next = old_racc->first_link;
616 new_racc->last_link = old_racc->last_link;
618 else
620 gcc_assert (!new_racc->last_link);
622 new_racc->first_link = old_racc->first_link;
623 new_racc->last_link = old_racc->last_link;
625 old_racc->first_link = old_racc->last_link = NULL;
628 /* Add ACCESS to the work queue (which is actually a stack). */
630 static void
631 add_access_to_work_queue (struct access *access)
633 if (!access->grp_queued)
635 gcc_assert (!access->next_queued);
636 access->next_queued = work_queue_head;
637 access->grp_queued = 1;
638 work_queue_head = access;
642 /* Pop an access from the work queue, and return it, assuming there is one. */
644 static struct access *
645 pop_access_from_work_queue (void)
647 struct access *access = work_queue_head;
649 work_queue_head = access->next_queued;
650 access->next_queued = NULL;
651 access->grp_queued = 0;
652 return access;
656 /* Allocate necessary structures. */
658 static void
659 sra_initialize (void)
661 candidate_bitmap = BITMAP_ALLOC (NULL);
662 candidates.create (vec_safe_length (cfun->local_decls) / 2);
663 should_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
664 cannot_scalarize_away_bitmap = BITMAP_ALLOC (NULL);
665 gcc_obstack_init (&name_obstack);
666 access_pool = create_alloc_pool ("SRA accesses", sizeof (struct access), 16);
667 link_pool = create_alloc_pool ("SRA links", sizeof (struct assign_link), 16);
668 base_access_vec = pointer_map_create ();
669 memset (&sra_stats, 0, sizeof (sra_stats));
670 encountered_apply_args = false;
671 encountered_recursive_call = false;
672 encountered_unchangable_recursive_call = false;
675 /* Hook fed to pointer_map_traverse, deallocate stored vectors. */
677 static bool
678 delete_base_accesses (const void *key ATTRIBUTE_UNUSED, void **value,
679 void *data ATTRIBUTE_UNUSED)
681 vec<access_p> *access_vec = (vec<access_p> *) *value;
682 vec_free (access_vec);
683 return true;
686 /* Deallocate all general structures. */
688 static void
689 sra_deinitialize (void)
691 BITMAP_FREE (candidate_bitmap);
692 candidates.dispose ();
693 BITMAP_FREE (should_scalarize_away_bitmap);
694 BITMAP_FREE (cannot_scalarize_away_bitmap);
695 free_alloc_pool (access_pool);
696 free_alloc_pool (link_pool);
697 obstack_free (&name_obstack, NULL);
699 pointer_map_traverse (base_access_vec, delete_base_accesses, NULL);
700 pointer_map_destroy (base_access_vec);
703 /* Remove DECL from candidates for SRA and write REASON to the dump file if
704 there is one. */
705 static void
706 disqualify_candidate (tree decl, const char *reason)
708 if (bitmap_clear_bit (candidate_bitmap, DECL_UID (decl)))
709 candidates.clear_slot (candidates.find_slot_with_hash (decl,
710 DECL_UID (decl),
711 NO_INSERT));
713 if (dump_file && (dump_flags & TDF_DETAILS))
715 fprintf (dump_file, "! Disqualifying ");
716 print_generic_expr (dump_file, decl, 0);
717 fprintf (dump_file, " - %s\n", reason);
721 /* Return true iff the type contains a field or an element which does not allow
722 scalarization. */
724 static bool
725 type_internals_preclude_sra_p (tree type, const char **msg)
727 tree fld;
728 tree et;
730 switch (TREE_CODE (type))
732 case RECORD_TYPE:
733 case UNION_TYPE:
734 case QUAL_UNION_TYPE:
735 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
736 if (TREE_CODE (fld) == FIELD_DECL)
738 tree ft = TREE_TYPE (fld);
740 if (TREE_THIS_VOLATILE (fld))
742 *msg = "volatile structure field";
743 return true;
745 if (!DECL_FIELD_OFFSET (fld))
747 *msg = "no structure field offset";
748 return true;
750 if (!DECL_SIZE (fld))
752 *msg = "zero structure field size";
753 return true;
755 if (!tree_fits_uhwi_p (DECL_FIELD_OFFSET (fld)))
757 *msg = "structure field offset not fixed";
758 return true;
760 if (!tree_fits_uhwi_p (DECL_SIZE (fld)))
762 *msg = "structure field size not fixed";
763 return true;
765 if (!tree_fits_shwi_p (bit_position (fld)))
767 *msg = "structure field size too big";
768 return true;
770 if (AGGREGATE_TYPE_P (ft)
771 && int_bit_position (fld) % BITS_PER_UNIT != 0)
773 *msg = "structure field is bit field";
774 return true;
777 if (AGGREGATE_TYPE_P (ft) && type_internals_preclude_sra_p (ft, msg))
778 return true;
781 return false;
783 case ARRAY_TYPE:
784 et = TREE_TYPE (type);
786 if (TYPE_VOLATILE (et))
788 *msg = "element type is volatile";
789 return true;
792 if (AGGREGATE_TYPE_P (et) && type_internals_preclude_sra_p (et, msg))
793 return true;
795 return false;
797 default:
798 return false;
802 /* If T is an SSA_NAME, return NULL if it is not a default def or return its
803 base variable if it is. Return T if it is not an SSA_NAME. */
805 static tree
806 get_ssa_base_param (tree t)
808 if (TREE_CODE (t) == SSA_NAME)
810 if (SSA_NAME_IS_DEFAULT_DEF (t))
811 return SSA_NAME_VAR (t);
812 else
813 return NULL_TREE;
815 return t;
818 /* Mark a dereference of BASE of distance DIST in a basic block tht STMT
819 belongs to, unless the BB has already been marked as a potentially
820 final. */
822 static void
823 mark_parm_dereference (tree base, HOST_WIDE_INT dist, gimple stmt)
825 basic_block bb = gimple_bb (stmt);
826 int idx, parm_index = 0;
827 tree parm;
829 if (bitmap_bit_p (final_bbs, bb->index))
830 return;
832 for (parm = DECL_ARGUMENTS (current_function_decl);
833 parm && parm != base;
834 parm = DECL_CHAIN (parm))
835 parm_index++;
837 gcc_assert (parm_index < func_param_count);
839 idx = bb->index * func_param_count + parm_index;
840 if (bb_dereferences[idx] < dist)
841 bb_dereferences[idx] = dist;
844 /* Allocate an access structure for BASE, OFFSET and SIZE, clear it, fill in
845 the three fields. Also add it to the vector of accesses corresponding to
846 the base. Finally, return the new access. */
848 static struct access *
849 create_access_1 (tree base, HOST_WIDE_INT offset, HOST_WIDE_INT size)
851 vec<access_p> *v;
852 struct access *access;
853 void **slot;
855 access = (struct access *) pool_alloc (access_pool);
856 memset (access, 0, sizeof (struct access));
857 access->base = base;
858 access->offset = offset;
859 access->size = size;
861 slot = pointer_map_contains (base_access_vec, base);
862 if (slot)
863 v = (vec<access_p> *) *slot;
864 else
865 vec_alloc (v, 32);
867 v->safe_push (access);
869 *((vec<access_p> **)
870 pointer_map_insert (base_access_vec, base)) = v;
872 return access;
875 /* Create and insert access for EXPR. Return created access, or NULL if it is
876 not possible. */
878 static struct access *
879 create_access (tree expr, gimple stmt, bool write)
881 struct access *access;
882 HOST_WIDE_INT offset, size, max_size;
883 tree base = expr;
884 bool ptr, unscalarizable_region = false;
886 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
888 if (sra_mode == SRA_MODE_EARLY_IPA
889 && TREE_CODE (base) == MEM_REF)
891 base = get_ssa_base_param (TREE_OPERAND (base, 0));
892 if (!base)
893 return NULL;
894 ptr = true;
896 else
897 ptr = false;
899 if (!DECL_P (base) || !bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
900 return NULL;
902 if (sra_mode == SRA_MODE_EARLY_IPA)
904 if (size < 0 || size != max_size)
906 disqualify_candidate (base, "Encountered a variable sized access.");
907 return NULL;
909 if (TREE_CODE (expr) == COMPONENT_REF
910 && DECL_BIT_FIELD (TREE_OPERAND (expr, 1)))
912 disqualify_candidate (base, "Encountered a bit-field access.");
913 return NULL;
915 gcc_checking_assert ((offset % BITS_PER_UNIT) == 0);
917 if (ptr)
918 mark_parm_dereference (base, offset + size, stmt);
920 else
922 if (size != max_size)
924 size = max_size;
925 unscalarizable_region = true;
927 if (size < 0)
929 disqualify_candidate (base, "Encountered an unconstrained access.");
930 return NULL;
934 access = create_access_1 (base, offset, size);
935 access->expr = expr;
936 access->type = TREE_TYPE (expr);
937 access->write = write;
938 access->grp_unscalarizable_region = unscalarizable_region;
939 access->stmt = stmt;
941 if (TREE_CODE (expr) == COMPONENT_REF
942 && DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1)))
943 access->non_addressable = 1;
945 return access;
949 /* Return true iff TYPE is a RECORD_TYPE with fields that are either of gimple
950 register types or (recursively) records with only these two kinds of fields.
951 It also returns false if any of these records contains a bit-field. */
953 static bool
954 type_consists_of_records_p (tree type)
956 tree fld;
958 if (TREE_CODE (type) != RECORD_TYPE)
959 return false;
961 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
962 if (TREE_CODE (fld) == FIELD_DECL)
964 tree ft = TREE_TYPE (fld);
966 if (DECL_BIT_FIELD (fld))
967 return false;
969 if (!is_gimple_reg_type (ft)
970 && !type_consists_of_records_p (ft))
971 return false;
974 return true;
977 /* Create total_scalarization accesses for all scalar type fields in DECL that
978 must be of a RECORD_TYPE conforming to type_consists_of_records_p. BASE
979 must be the top-most VAR_DECL representing the variable, OFFSET must be the
980 offset of DECL within BASE. REF must be the memory reference expression for
981 the given decl. */
983 static void
984 completely_scalarize_record (tree base, tree decl, HOST_WIDE_INT offset,
985 tree ref)
987 tree fld, decl_type = TREE_TYPE (decl);
989 for (fld = TYPE_FIELDS (decl_type); fld; fld = DECL_CHAIN (fld))
990 if (TREE_CODE (fld) == FIELD_DECL)
992 HOST_WIDE_INT pos = offset + int_bit_position (fld);
993 tree ft = TREE_TYPE (fld);
994 tree nref = build3 (COMPONENT_REF, TREE_TYPE (fld), ref, fld,
995 NULL_TREE);
997 if (is_gimple_reg_type (ft))
999 struct access *access;
1000 HOST_WIDE_INT size;
1002 size = tree_to_uhwi (DECL_SIZE (fld));
1003 access = create_access_1 (base, pos, size);
1004 access->expr = nref;
1005 access->type = ft;
1006 access->grp_total_scalarization = 1;
1007 /* Accesses for intraprocedural SRA can have their stmt NULL. */
1009 else
1010 completely_scalarize_record (base, fld, pos, nref);
1014 /* Create total_scalarization accesses for all scalar type fields in VAR and
1015 for VAR a a whole. VAR must be of a RECORD_TYPE conforming to
1016 type_consists_of_records_p. */
1018 static void
1019 completely_scalarize_var (tree var)
1021 HOST_WIDE_INT size = tree_to_uhwi (DECL_SIZE (var));
1022 struct access *access;
1024 access = create_access_1 (var, 0, size);
1025 access->expr = var;
1026 access->type = TREE_TYPE (var);
1027 access->grp_total_scalarization = 1;
1029 completely_scalarize_record (var, var, 0, var);
1032 /* Return true if REF has an VIEW_CONVERT_EXPR somewhere in it. */
1034 static inline bool
1035 contains_view_convert_expr_p (const_tree ref)
1037 while (handled_component_p (ref))
1039 if (TREE_CODE (ref) == VIEW_CONVERT_EXPR)
1040 return true;
1041 ref = TREE_OPERAND (ref, 0);
1044 return false;
1047 /* Search the given tree for a declaration by skipping handled components and
1048 exclude it from the candidates. */
1050 static void
1051 disqualify_base_of_expr (tree t, const char *reason)
1053 t = get_base_address (t);
1054 if (sra_mode == SRA_MODE_EARLY_IPA
1055 && TREE_CODE (t) == MEM_REF)
1056 t = get_ssa_base_param (TREE_OPERAND (t, 0));
1058 if (t && DECL_P (t))
1059 disqualify_candidate (t, reason);
1062 /* Scan expression EXPR and create access structures for all accesses to
1063 candidates for scalarization. Return the created access or NULL if none is
1064 created. */
1066 static struct access *
1067 build_access_from_expr_1 (tree expr, gimple stmt, bool write)
1069 struct access *ret = NULL;
1070 bool partial_ref;
1072 if (TREE_CODE (expr) == BIT_FIELD_REF
1073 || TREE_CODE (expr) == IMAGPART_EXPR
1074 || TREE_CODE (expr) == REALPART_EXPR)
1076 expr = TREE_OPERAND (expr, 0);
1077 partial_ref = true;
1079 else
1080 partial_ref = false;
1082 /* We need to dive through V_C_Es in order to get the size of its parameter
1083 and not the result type. Ada produces such statements. We are also
1084 capable of handling the topmost V_C_E but not any of those buried in other
1085 handled components. */
1086 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
1087 expr = TREE_OPERAND (expr, 0);
1089 if (contains_view_convert_expr_p (expr))
1091 disqualify_base_of_expr (expr, "V_C_E under a different handled "
1092 "component.");
1093 return NULL;
1095 if (TREE_THIS_VOLATILE (expr))
1097 disqualify_base_of_expr (expr, "part of a volatile reference.");
1098 return NULL;
1101 switch (TREE_CODE (expr))
1103 case MEM_REF:
1104 if (TREE_CODE (TREE_OPERAND (expr, 0)) != ADDR_EXPR
1105 && sra_mode != SRA_MODE_EARLY_IPA)
1106 return NULL;
1107 /* fall through */
1108 case VAR_DECL:
1109 case PARM_DECL:
1110 case RESULT_DECL:
1111 case COMPONENT_REF:
1112 case ARRAY_REF:
1113 case ARRAY_RANGE_REF:
1114 ret = create_access (expr, stmt, write);
1115 break;
1117 default:
1118 break;
1121 if (write && partial_ref && ret)
1122 ret->grp_partial_lhs = 1;
1124 return ret;
1127 /* Scan expression EXPR and create access structures for all accesses to
1128 candidates for scalarization. Return true if any access has been inserted.
1129 STMT must be the statement from which the expression is taken, WRITE must be
1130 true if the expression is a store and false otherwise. */
1132 static bool
1133 build_access_from_expr (tree expr, gimple stmt, bool write)
1135 struct access *access;
1137 access = build_access_from_expr_1 (expr, stmt, write);
1138 if (access)
1140 /* This means the aggregate is accesses as a whole in a way other than an
1141 assign statement and thus cannot be removed even if we had a scalar
1142 replacement for everything. */
1143 if (cannot_scalarize_away_bitmap)
1144 bitmap_set_bit (cannot_scalarize_away_bitmap, DECL_UID (access->base));
1145 return true;
1147 return false;
1150 /* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
1151 modes in which it matters, return true iff they have been disqualified. RHS
1152 may be NULL, in that case ignore it. If we scalarize an aggregate in
1153 intra-SRA we may need to add statements after each statement. This is not
1154 possible if a statement unconditionally has to end the basic block. */
1155 static bool
1156 disqualify_ops_if_throwing_stmt (gimple stmt, tree lhs, tree rhs)
1158 if ((sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1159 && (stmt_can_throw_internal (stmt) || stmt_ends_bb_p (stmt)))
1161 disqualify_base_of_expr (lhs, "LHS of a throwing stmt.");
1162 if (rhs)
1163 disqualify_base_of_expr (rhs, "RHS of a throwing stmt.");
1164 return true;
1166 return false;
1169 /* Scan expressions occurring in STMT, create access structures for all accesses
1170 to candidates for scalarization and remove those candidates which occur in
1171 statements or expressions that prevent them from being split apart. Return
1172 true if any access has been inserted. */
1174 static bool
1175 build_accesses_from_assign (gimple stmt)
1177 tree lhs, rhs;
1178 struct access *lacc, *racc;
1180 if (!gimple_assign_single_p (stmt)
1181 /* Scope clobbers don't influence scalarization. */
1182 || gimple_clobber_p (stmt))
1183 return false;
1185 lhs = gimple_assign_lhs (stmt);
1186 rhs = gimple_assign_rhs1 (stmt);
1188 if (disqualify_ops_if_throwing_stmt (stmt, lhs, rhs))
1189 return false;
1191 racc = build_access_from_expr_1 (rhs, stmt, false);
1192 lacc = build_access_from_expr_1 (lhs, stmt, true);
1194 if (lacc)
1195 lacc->grp_assignment_write = 1;
1197 if (racc)
1199 racc->grp_assignment_read = 1;
1200 if (should_scalarize_away_bitmap && !gimple_has_volatile_ops (stmt)
1201 && !is_gimple_reg_type (racc->type))
1202 bitmap_set_bit (should_scalarize_away_bitmap, DECL_UID (racc->base));
1205 if (lacc && racc
1206 && (sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
1207 && !lacc->grp_unscalarizable_region
1208 && !racc->grp_unscalarizable_region
1209 && AGGREGATE_TYPE_P (TREE_TYPE (lhs))
1210 && lacc->size == racc->size
1211 && useless_type_conversion_p (lacc->type, racc->type))
1213 struct assign_link *link;
1215 link = (struct assign_link *) pool_alloc (link_pool);
1216 memset (link, 0, sizeof (struct assign_link));
1218 link->lacc = lacc;
1219 link->racc = racc;
1221 add_link_to_rhs (racc, link);
1224 return lacc || racc;
1227 /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine
1228 GIMPLE_ASM operands with memory constrains which cannot be scalarized. */
1230 static bool
1231 asm_visit_addr (gimple, tree op, tree, void *)
1233 op = get_base_address (op);
1234 if (op
1235 && DECL_P (op))
1236 disqualify_candidate (op, "Non-scalarizable GIMPLE_ASM operand.");
1238 return false;
1241 /* Return true iff callsite CALL has at least as many actual arguments as there
1242 are formal parameters of the function currently processed by IPA-SRA and
1243 that their types match. */
1245 static inline bool
1246 callsite_arguments_match_p (gimple call)
1248 if (gimple_call_num_args (call) < (unsigned) func_param_count)
1249 return false;
1251 tree parm;
1252 int i;
1253 for (parm = DECL_ARGUMENTS (current_function_decl), i = 0;
1254 parm;
1255 parm = DECL_CHAIN (parm), i++)
1257 tree arg = gimple_call_arg (call, i);
1258 if (!useless_type_conversion_p (TREE_TYPE (parm), TREE_TYPE (arg)))
1259 return false;
1261 return true;
1264 /* Scan function and look for interesting expressions and create access
1265 structures for them. Return true iff any access is created. */
1267 static bool
1268 scan_function (void)
1270 basic_block bb;
1271 bool ret = false;
1273 FOR_EACH_BB_FN (bb, cfun)
1275 gimple_stmt_iterator gsi;
1276 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1278 gimple stmt = gsi_stmt (gsi);
1279 tree t;
1280 unsigned i;
1282 if (final_bbs && stmt_can_throw_external (stmt))
1283 bitmap_set_bit (final_bbs, bb->index);
1284 switch (gimple_code (stmt))
1286 case GIMPLE_RETURN:
1287 t = gimple_return_retval (stmt);
1288 if (t != NULL_TREE)
1289 ret |= build_access_from_expr (t, stmt, false);
1290 if (final_bbs)
1291 bitmap_set_bit (final_bbs, bb->index);
1292 break;
1294 case GIMPLE_ASSIGN:
1295 ret |= build_accesses_from_assign (stmt);
1296 break;
1298 case GIMPLE_CALL:
1299 for (i = 0; i < gimple_call_num_args (stmt); i++)
1300 ret |= build_access_from_expr (gimple_call_arg (stmt, i),
1301 stmt, false);
1303 if (sra_mode == SRA_MODE_EARLY_IPA)
1305 tree dest = gimple_call_fndecl (stmt);
1306 int flags = gimple_call_flags (stmt);
1308 if (dest)
1310 if (DECL_BUILT_IN_CLASS (dest) == BUILT_IN_NORMAL
1311 && DECL_FUNCTION_CODE (dest) == BUILT_IN_APPLY_ARGS)
1312 encountered_apply_args = true;
1313 if (recursive_call_p (current_function_decl, dest))
1315 encountered_recursive_call = true;
1316 if (!callsite_arguments_match_p (stmt))
1317 encountered_unchangable_recursive_call = true;
1321 if (final_bbs
1322 && (flags & (ECF_CONST | ECF_PURE)) == 0)
1323 bitmap_set_bit (final_bbs, bb->index);
1326 t = gimple_call_lhs (stmt);
1327 if (t && !disqualify_ops_if_throwing_stmt (stmt, t, NULL))
1328 ret |= build_access_from_expr (t, stmt, true);
1329 break;
1331 case GIMPLE_ASM:
1332 walk_stmt_load_store_addr_ops (stmt, NULL, NULL, NULL,
1333 asm_visit_addr);
1334 if (final_bbs)
1335 bitmap_set_bit (final_bbs, bb->index);
1337 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
1339 t = TREE_VALUE (gimple_asm_input_op (stmt, i));
1340 ret |= build_access_from_expr (t, stmt, false);
1342 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
1344 t = TREE_VALUE (gimple_asm_output_op (stmt, i));
1345 ret |= build_access_from_expr (t, stmt, true);
1347 break;
1349 default:
1350 break;
1355 return ret;
1358 /* Helper of QSORT function. There are pointers to accesses in the array. An
1359 access is considered smaller than another if it has smaller offset or if the
1360 offsets are the same but is size is bigger. */
1362 static int
1363 compare_access_positions (const void *a, const void *b)
1365 const access_p *fp1 = (const access_p *) a;
1366 const access_p *fp2 = (const access_p *) b;
1367 const access_p f1 = *fp1;
1368 const access_p f2 = *fp2;
1370 if (f1->offset != f2->offset)
1371 return f1->offset < f2->offset ? -1 : 1;
1373 if (f1->size == f2->size)
1375 if (f1->type == f2->type)
1376 return 0;
1377 /* Put any non-aggregate type before any aggregate type. */
1378 else if (!is_gimple_reg_type (f1->type)
1379 && is_gimple_reg_type (f2->type))
1380 return 1;
1381 else if (is_gimple_reg_type (f1->type)
1382 && !is_gimple_reg_type (f2->type))
1383 return -1;
1384 /* Put any complex or vector type before any other scalar type. */
1385 else if (TREE_CODE (f1->type) != COMPLEX_TYPE
1386 && TREE_CODE (f1->type) != VECTOR_TYPE
1387 && (TREE_CODE (f2->type) == COMPLEX_TYPE
1388 || TREE_CODE (f2->type) == VECTOR_TYPE))
1389 return 1;
1390 else if ((TREE_CODE (f1->type) == COMPLEX_TYPE
1391 || TREE_CODE (f1->type) == VECTOR_TYPE)
1392 && TREE_CODE (f2->type) != COMPLEX_TYPE
1393 && TREE_CODE (f2->type) != VECTOR_TYPE)
1394 return -1;
1395 /* Put the integral type with the bigger precision first. */
1396 else if (INTEGRAL_TYPE_P (f1->type)
1397 && INTEGRAL_TYPE_P (f2->type))
1398 return TYPE_PRECISION (f2->type) - TYPE_PRECISION (f1->type);
1399 /* Put any integral type with non-full precision last. */
1400 else if (INTEGRAL_TYPE_P (f1->type)
1401 && (TREE_INT_CST_LOW (TYPE_SIZE (f1->type))
1402 != TYPE_PRECISION (f1->type)))
1403 return 1;
1404 else if (INTEGRAL_TYPE_P (f2->type)
1405 && (TREE_INT_CST_LOW (TYPE_SIZE (f2->type))
1406 != TYPE_PRECISION (f2->type)))
1407 return -1;
1408 /* Stabilize the sort. */
1409 return TYPE_UID (f1->type) - TYPE_UID (f2->type);
1412 /* We want the bigger accesses first, thus the opposite operator in the next
1413 line: */
1414 return f1->size > f2->size ? -1 : 1;
1418 /* Append a name of the declaration to the name obstack. A helper function for
1419 make_fancy_name. */
1421 static void
1422 make_fancy_decl_name (tree decl)
1424 char buffer[32];
1426 tree name = DECL_NAME (decl);
1427 if (name)
1428 obstack_grow (&name_obstack, IDENTIFIER_POINTER (name),
1429 IDENTIFIER_LENGTH (name));
1430 else
1432 sprintf (buffer, "D%u", DECL_UID (decl));
1433 obstack_grow (&name_obstack, buffer, strlen (buffer));
1437 /* Helper for make_fancy_name. */
1439 static void
1440 make_fancy_name_1 (tree expr)
1442 char buffer[32];
1443 tree index;
1445 if (DECL_P (expr))
1447 make_fancy_decl_name (expr);
1448 return;
1451 switch (TREE_CODE (expr))
1453 case COMPONENT_REF:
1454 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1455 obstack_1grow (&name_obstack, '$');
1456 make_fancy_decl_name (TREE_OPERAND (expr, 1));
1457 break;
1459 case ARRAY_REF:
1460 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1461 obstack_1grow (&name_obstack, '$');
1462 /* Arrays with only one element may not have a constant as their
1463 index. */
1464 index = TREE_OPERAND (expr, 1);
1465 if (TREE_CODE (index) != INTEGER_CST)
1466 break;
1467 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC, TREE_INT_CST_LOW (index));
1468 obstack_grow (&name_obstack, buffer, strlen (buffer));
1469 break;
1471 case ADDR_EXPR:
1472 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1473 break;
1475 case MEM_REF:
1476 make_fancy_name_1 (TREE_OPERAND (expr, 0));
1477 if (!integer_zerop (TREE_OPERAND (expr, 1)))
1479 obstack_1grow (&name_obstack, '$');
1480 sprintf (buffer, HOST_WIDE_INT_PRINT_DEC,
1481 TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)));
1482 obstack_grow (&name_obstack, buffer, strlen (buffer));
1484 break;
1486 case BIT_FIELD_REF:
1487 case REALPART_EXPR:
1488 case IMAGPART_EXPR:
1489 gcc_unreachable (); /* we treat these as scalars. */
1490 break;
1491 default:
1492 break;
1496 /* Create a human readable name for replacement variable of ACCESS. */
1498 static char *
1499 make_fancy_name (tree expr)
1501 make_fancy_name_1 (expr);
1502 obstack_1grow (&name_obstack, '\0');
1503 return XOBFINISH (&name_obstack, char *);
1506 /* Construct a MEM_REF that would reference a part of aggregate BASE of type
1507 EXP_TYPE at the given OFFSET. If BASE is something for which
1508 get_addr_base_and_unit_offset returns NULL, gsi must be non-NULL and is used
1509 to insert new statements either before or below the current one as specified
1510 by INSERT_AFTER. This function is not capable of handling bitfields.
1512 BASE must be either a declaration or a memory reference that has correct
1513 alignment ifformation embeded in it (e.g. a pre-existing one in SRA). */
1515 tree
1516 build_ref_for_offset (location_t loc, tree base, HOST_WIDE_INT offset,
1517 tree exp_type, gimple_stmt_iterator *gsi,
1518 bool insert_after)
1520 tree prev_base = base;
1521 tree off;
1522 tree mem_ref;
1523 HOST_WIDE_INT base_offset;
1524 unsigned HOST_WIDE_INT misalign;
1525 unsigned int align;
1527 gcc_checking_assert (offset % BITS_PER_UNIT == 0);
1528 get_object_alignment_1 (base, &align, &misalign);
1529 base = get_addr_base_and_unit_offset (base, &base_offset);
1531 /* get_addr_base_and_unit_offset returns NULL for references with a variable
1532 offset such as array[var_index]. */
1533 if (!base)
1535 gimple stmt;
1536 tree tmp, addr;
1538 gcc_checking_assert (gsi);
1539 tmp = make_ssa_name (build_pointer_type (TREE_TYPE (prev_base)), NULL);
1540 addr = build_fold_addr_expr (unshare_expr (prev_base));
1541 STRIP_USELESS_TYPE_CONVERSION (addr);
1542 stmt = gimple_build_assign (tmp, addr);
1543 gimple_set_location (stmt, loc);
1544 if (insert_after)
1545 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
1546 else
1547 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1549 off = build_int_cst (reference_alias_ptr_type (prev_base),
1550 offset / BITS_PER_UNIT);
1551 base = tmp;
1553 else if (TREE_CODE (base) == MEM_REF)
1555 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1556 base_offset + offset / BITS_PER_UNIT);
1557 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off);
1558 base = unshare_expr (TREE_OPERAND (base, 0));
1560 else
1562 off = build_int_cst (reference_alias_ptr_type (base),
1563 base_offset + offset / BITS_PER_UNIT);
1564 base = build_fold_addr_expr (unshare_expr (base));
1567 misalign = (misalign + offset) & (align - 1);
1568 if (misalign != 0)
1569 align = (misalign & -misalign);
1570 if (align < TYPE_ALIGN (exp_type))
1571 exp_type = build_aligned_type (exp_type, align);
1573 mem_ref = fold_build2_loc (loc, MEM_REF, exp_type, base, off);
1574 if (TREE_THIS_VOLATILE (prev_base))
1575 TREE_THIS_VOLATILE (mem_ref) = 1;
1576 if (TREE_SIDE_EFFECTS (prev_base))
1577 TREE_SIDE_EFFECTS (mem_ref) = 1;
1578 return mem_ref;
1581 /* Construct a memory reference to a part of an aggregate BASE at the given
1582 OFFSET and of the same type as MODEL. In case this is a reference to a
1583 bit-field, the function will replicate the last component_ref of model's
1584 expr to access it. GSI and INSERT_AFTER have the same meaning as in
1585 build_ref_for_offset. */
1587 static tree
1588 build_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1589 struct access *model, gimple_stmt_iterator *gsi,
1590 bool insert_after)
1592 if (TREE_CODE (model->expr) == COMPONENT_REF
1593 && DECL_BIT_FIELD (TREE_OPERAND (model->expr, 1)))
1595 /* This access represents a bit-field. */
1596 tree t, exp_type, fld = TREE_OPERAND (model->expr, 1);
1598 offset -= int_bit_position (fld);
1599 exp_type = TREE_TYPE (TREE_OPERAND (model->expr, 0));
1600 t = build_ref_for_offset (loc, base, offset, exp_type, gsi, insert_after);
1601 return fold_build3_loc (loc, COMPONENT_REF, TREE_TYPE (fld), t, fld,
1602 NULL_TREE);
1604 else
1605 return build_ref_for_offset (loc, base, offset, model->type,
1606 gsi, insert_after);
1609 /* Attempt to build a memory reference that we could but into a gimple
1610 debug_bind statement. Similar to build_ref_for_model but punts if it has to
1611 create statements and return s NULL instead. This function also ignores
1612 alignment issues and so its results should never end up in non-debug
1613 statements. */
1615 static tree
1616 build_debug_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
1617 struct access *model)
1619 HOST_WIDE_INT base_offset;
1620 tree off;
1622 if (TREE_CODE (model->expr) == COMPONENT_REF
1623 && DECL_BIT_FIELD (TREE_OPERAND (model->expr, 1)))
1624 return NULL_TREE;
1626 base = get_addr_base_and_unit_offset (base, &base_offset);
1627 if (!base)
1628 return NULL_TREE;
1629 if (TREE_CODE (base) == MEM_REF)
1631 off = build_int_cst (TREE_TYPE (TREE_OPERAND (base, 1)),
1632 base_offset + offset / BITS_PER_UNIT);
1633 off = int_const_binop (PLUS_EXPR, TREE_OPERAND (base, 1), off);
1634 base = unshare_expr (TREE_OPERAND (base, 0));
1636 else
1638 off = build_int_cst (reference_alias_ptr_type (base),
1639 base_offset + offset / BITS_PER_UNIT);
1640 base = build_fold_addr_expr (unshare_expr (base));
1643 return fold_build2_loc (loc, MEM_REF, model->type, base, off);
1646 /* Construct a memory reference consisting of component_refs and array_refs to
1647 a part of an aggregate *RES (which is of type TYPE). The requested part
1648 should have type EXP_TYPE at be the given OFFSET. This function might not
1649 succeed, it returns true when it does and only then *RES points to something
1650 meaningful. This function should be used only to build expressions that we
1651 might need to present to user (e.g. in warnings). In all other situations,
1652 build_ref_for_model or build_ref_for_offset should be used instead. */
1654 static bool
1655 build_user_friendly_ref_for_offset (tree *res, tree type, HOST_WIDE_INT offset,
1656 tree exp_type)
1658 while (1)
1660 tree fld;
1661 tree tr_size, index, minidx;
1662 HOST_WIDE_INT el_size;
1664 if (offset == 0 && exp_type
1665 && types_compatible_p (exp_type, type))
1666 return true;
1668 switch (TREE_CODE (type))
1670 case UNION_TYPE:
1671 case QUAL_UNION_TYPE:
1672 case RECORD_TYPE:
1673 for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
1675 HOST_WIDE_INT pos, size;
1676 tree tr_pos, expr, *expr_ptr;
1678 if (TREE_CODE (fld) != FIELD_DECL)
1679 continue;
1681 tr_pos = bit_position (fld);
1682 if (!tr_pos || !tree_fits_uhwi_p (tr_pos))
1683 continue;
1684 pos = tree_to_uhwi (tr_pos);
1685 gcc_assert (TREE_CODE (type) == RECORD_TYPE || pos == 0);
1686 tr_size = DECL_SIZE (fld);
1687 if (!tr_size || !tree_fits_uhwi_p (tr_size))
1688 continue;
1689 size = tree_to_uhwi (tr_size);
1690 if (size == 0)
1692 if (pos != offset)
1693 continue;
1695 else if (pos > offset || (pos + size) <= offset)
1696 continue;
1698 expr = build3 (COMPONENT_REF, TREE_TYPE (fld), *res, fld,
1699 NULL_TREE);
1700 expr_ptr = &expr;
1701 if (build_user_friendly_ref_for_offset (expr_ptr, TREE_TYPE (fld),
1702 offset - pos, exp_type))
1704 *res = expr;
1705 return true;
1708 return false;
1710 case ARRAY_TYPE:
1711 tr_size = TYPE_SIZE (TREE_TYPE (type));
1712 if (!tr_size || !tree_fits_uhwi_p (tr_size))
1713 return false;
1714 el_size = tree_to_uhwi (tr_size);
1716 minidx = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
1717 if (TREE_CODE (minidx) != INTEGER_CST || el_size == 0)
1718 return false;
1719 index = build_int_cst (TYPE_DOMAIN (type), offset / el_size);
1720 if (!integer_zerop (minidx))
1721 index = int_const_binop (PLUS_EXPR, index, minidx);
1722 *res = build4 (ARRAY_REF, TREE_TYPE (type), *res, index,
1723 NULL_TREE, NULL_TREE);
1724 offset = offset % el_size;
1725 type = TREE_TYPE (type);
1726 break;
1728 default:
1729 if (offset != 0)
1730 return false;
1732 if (exp_type)
1733 return false;
1734 else
1735 return true;
1740 /* Return true iff TYPE is stdarg va_list type. */
1742 static inline bool
1743 is_va_list_type (tree type)
1745 return TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (va_list_type_node);
1748 /* Print message to dump file why a variable was rejected. */
1750 static void
1751 reject (tree var, const char *msg)
1753 if (dump_file && (dump_flags & TDF_DETAILS))
1755 fprintf (dump_file, "Rejected (%d): %s: ", DECL_UID (var), msg);
1756 print_generic_expr (dump_file, var, 0);
1757 fprintf (dump_file, "\n");
1761 /* Return true if VAR is a candidate for SRA. */
1763 static bool
1764 maybe_add_sra_candidate (tree var)
1766 tree type = TREE_TYPE (var);
1767 const char *msg;
1768 tree_node **slot;
1770 if (!AGGREGATE_TYPE_P (type))
1772 reject (var, "not aggregate");
1773 return false;
1775 if (needs_to_live_in_memory (var))
1777 reject (var, "needs to live in memory");
1778 return false;
1780 if (TREE_THIS_VOLATILE (var))
1782 reject (var, "is volatile");
1783 return false;
1785 if (!COMPLETE_TYPE_P (type))
1787 reject (var, "has incomplete type");
1788 return false;
1790 if (!tree_fits_uhwi_p (TYPE_SIZE (type)))
1792 reject (var, "type size not fixed");
1793 return false;
1795 if (tree_to_uhwi (TYPE_SIZE (type)) == 0)
1797 reject (var, "type size is zero");
1798 return false;
1800 if (type_internals_preclude_sra_p (type, &msg))
1802 reject (var, msg);
1803 return false;
1805 if (/* Fix for PR 41089. tree-stdarg.c needs to have va_lists intact but
1806 we also want to schedule it rather late. Thus we ignore it in
1807 the early pass. */
1808 (sra_mode == SRA_MODE_EARLY_INTRA
1809 && is_va_list_type (type)))
1811 reject (var, "is va_list");
1812 return false;
1815 bitmap_set_bit (candidate_bitmap, DECL_UID (var));
1816 slot = candidates.find_slot_with_hash (var, DECL_UID (var), INSERT);
1817 *slot = var;
1819 if (dump_file && (dump_flags & TDF_DETAILS))
1821 fprintf (dump_file, "Candidate (%d): ", DECL_UID (var));
1822 print_generic_expr (dump_file, var, 0);
1823 fprintf (dump_file, "\n");
1826 return true;
1829 /* The very first phase of intraprocedural SRA. It marks in candidate_bitmap
1830 those with type which is suitable for scalarization. */
1832 static bool
1833 find_var_candidates (void)
1835 tree var, parm;
1836 unsigned int i;
1837 bool ret = false;
1839 for (parm = DECL_ARGUMENTS (current_function_decl);
1840 parm;
1841 parm = DECL_CHAIN (parm))
1842 ret |= maybe_add_sra_candidate (parm);
1844 FOR_EACH_LOCAL_DECL (cfun, i, var)
1846 if (TREE_CODE (var) != VAR_DECL)
1847 continue;
1849 ret |= maybe_add_sra_candidate (var);
1852 return ret;
1855 /* Sort all accesses for the given variable, check for partial overlaps and
1856 return NULL if there are any. If there are none, pick a representative for
1857 each combination of offset and size and create a linked list out of them.
1858 Return the pointer to the first representative and make sure it is the first
1859 one in the vector of accesses. */
1861 static struct access *
1862 sort_and_splice_var_accesses (tree var)
1864 int i, j, access_count;
1865 struct access *res, **prev_acc_ptr = &res;
1866 vec<access_p> *access_vec;
1867 bool first = true;
1868 HOST_WIDE_INT low = -1, high = 0;
1870 access_vec = get_base_access_vector (var);
1871 if (!access_vec)
1872 return NULL;
1873 access_count = access_vec->length ();
1875 /* Sort by <OFFSET, SIZE>. */
1876 access_vec->qsort (compare_access_positions);
1878 i = 0;
1879 while (i < access_count)
1881 struct access *access = (*access_vec)[i];
1882 bool grp_write = access->write;
1883 bool grp_read = !access->write;
1884 bool grp_scalar_write = access->write
1885 && is_gimple_reg_type (access->type);
1886 bool grp_scalar_read = !access->write
1887 && is_gimple_reg_type (access->type);
1888 bool grp_assignment_read = access->grp_assignment_read;
1889 bool grp_assignment_write = access->grp_assignment_write;
1890 bool multiple_scalar_reads = false;
1891 bool total_scalarization = access->grp_total_scalarization;
1892 bool grp_partial_lhs = access->grp_partial_lhs;
1893 bool first_scalar = is_gimple_reg_type (access->type);
1894 bool unscalarizable_region = access->grp_unscalarizable_region;
1896 if (first || access->offset >= high)
1898 first = false;
1899 low = access->offset;
1900 high = access->offset + access->size;
1902 else if (access->offset > low && access->offset + access->size > high)
1903 return NULL;
1904 else
1905 gcc_assert (access->offset >= low
1906 && access->offset + access->size <= high);
1908 j = i + 1;
1909 while (j < access_count)
1911 struct access *ac2 = (*access_vec)[j];
1912 if (ac2->offset != access->offset || ac2->size != access->size)
1913 break;
1914 if (ac2->write)
1916 grp_write = true;
1917 grp_scalar_write = (grp_scalar_write
1918 || is_gimple_reg_type (ac2->type));
1920 else
1922 grp_read = true;
1923 if (is_gimple_reg_type (ac2->type))
1925 if (grp_scalar_read)
1926 multiple_scalar_reads = true;
1927 else
1928 grp_scalar_read = true;
1931 grp_assignment_read |= ac2->grp_assignment_read;
1932 grp_assignment_write |= ac2->grp_assignment_write;
1933 grp_partial_lhs |= ac2->grp_partial_lhs;
1934 unscalarizable_region |= ac2->grp_unscalarizable_region;
1935 total_scalarization |= ac2->grp_total_scalarization;
1936 relink_to_new_repr (access, ac2);
1938 /* If there are both aggregate-type and scalar-type accesses with
1939 this combination of size and offset, the comparison function
1940 should have put the scalars first. */
1941 gcc_assert (first_scalar || !is_gimple_reg_type (ac2->type));
1942 ac2->group_representative = access;
1943 j++;
1946 i = j;
1948 access->group_representative = access;
1949 access->grp_write = grp_write;
1950 access->grp_read = grp_read;
1951 access->grp_scalar_read = grp_scalar_read;
1952 access->grp_scalar_write = grp_scalar_write;
1953 access->grp_assignment_read = grp_assignment_read;
1954 access->grp_assignment_write = grp_assignment_write;
1955 access->grp_hint = multiple_scalar_reads || total_scalarization;
1956 access->grp_total_scalarization = total_scalarization;
1957 access->grp_partial_lhs = grp_partial_lhs;
1958 access->grp_unscalarizable_region = unscalarizable_region;
1959 if (access->first_link)
1960 add_access_to_work_queue (access);
1962 *prev_acc_ptr = access;
1963 prev_acc_ptr = &access->next_grp;
1966 gcc_assert (res == (*access_vec)[0]);
1967 return res;
1970 /* Create a variable for the given ACCESS which determines the type, name and a
1971 few other properties. Return the variable declaration and store it also to
1972 ACCESS->replacement. */
1974 static tree
1975 create_access_replacement (struct access *access)
1977 tree repl;
1979 if (access->grp_to_be_debug_replaced)
1981 repl = create_tmp_var_raw (access->type, NULL);
1982 DECL_CONTEXT (repl) = current_function_decl;
1984 else
1985 repl = create_tmp_var (access->type, "SR");
1986 if (TREE_CODE (access->type) == COMPLEX_TYPE
1987 || TREE_CODE (access->type) == VECTOR_TYPE)
1989 if (!access->grp_partial_lhs)
1990 DECL_GIMPLE_REG_P (repl) = 1;
1992 else if (access->grp_partial_lhs
1993 && is_gimple_reg_type (access->type))
1994 TREE_ADDRESSABLE (repl) = 1;
1996 DECL_SOURCE_LOCATION (repl) = DECL_SOURCE_LOCATION (access->base);
1997 DECL_ARTIFICIAL (repl) = 1;
1998 DECL_IGNORED_P (repl) = DECL_IGNORED_P (access->base);
2000 if (DECL_NAME (access->base)
2001 && !DECL_IGNORED_P (access->base)
2002 && !DECL_ARTIFICIAL (access->base))
2004 char *pretty_name = make_fancy_name (access->expr);
2005 tree debug_expr = unshare_expr_without_location (access->expr), d;
2006 bool fail = false;
2008 DECL_NAME (repl) = get_identifier (pretty_name);
2009 obstack_free (&name_obstack, pretty_name);
2011 /* Get rid of any SSA_NAMEs embedded in debug_expr,
2012 as DECL_DEBUG_EXPR isn't considered when looking for still
2013 used SSA_NAMEs and thus they could be freed. All debug info
2014 generation cares is whether something is constant or variable
2015 and that get_ref_base_and_extent works properly on the
2016 expression. It cannot handle accesses at a non-constant offset
2017 though, so just give up in those cases. */
2018 for (d = debug_expr;
2019 !fail && (handled_component_p (d) || TREE_CODE (d) == MEM_REF);
2020 d = TREE_OPERAND (d, 0))
2021 switch (TREE_CODE (d))
2023 case ARRAY_REF:
2024 case ARRAY_RANGE_REF:
2025 if (TREE_OPERAND (d, 1)
2026 && TREE_CODE (TREE_OPERAND (d, 1)) != INTEGER_CST)
2027 fail = true;
2028 if (TREE_OPERAND (d, 3)
2029 && TREE_CODE (TREE_OPERAND (d, 3)) != INTEGER_CST)
2030 fail = true;
2031 /* FALLTHRU */
2032 case COMPONENT_REF:
2033 if (TREE_OPERAND (d, 2)
2034 && TREE_CODE (TREE_OPERAND (d, 2)) != INTEGER_CST)
2035 fail = true;
2036 break;
2037 case MEM_REF:
2038 if (TREE_CODE (TREE_OPERAND (d, 0)) != ADDR_EXPR)
2039 fail = true;
2040 else
2041 d = TREE_OPERAND (d, 0);
2042 break;
2043 default:
2044 break;
2046 if (!fail)
2048 SET_DECL_DEBUG_EXPR (repl, debug_expr);
2049 DECL_HAS_DEBUG_EXPR_P (repl) = 1;
2051 if (access->grp_no_warning)
2052 TREE_NO_WARNING (repl) = 1;
2053 else
2054 TREE_NO_WARNING (repl) = TREE_NO_WARNING (access->base);
2056 else
2057 TREE_NO_WARNING (repl) = 1;
2059 if (dump_file)
2061 if (access->grp_to_be_debug_replaced)
2063 fprintf (dump_file, "Created a debug-only replacement for ");
2064 print_generic_expr (dump_file, access->base, 0);
2065 fprintf (dump_file, " offset: %u, size: %u\n",
2066 (unsigned) access->offset, (unsigned) access->size);
2068 else
2070 fprintf (dump_file, "Created a replacement for ");
2071 print_generic_expr (dump_file, access->base, 0);
2072 fprintf (dump_file, " offset: %u, size: %u: ",
2073 (unsigned) access->offset, (unsigned) access->size);
2074 print_generic_expr (dump_file, repl, 0);
2075 fprintf (dump_file, "\n");
2078 sra_stats.replacements++;
2080 return repl;
2083 /* Return ACCESS scalar replacement, create it if it does not exist yet. */
2085 static inline tree
2086 get_access_replacement (struct access *access)
2088 gcc_checking_assert (access->replacement_decl);
2089 return access->replacement_decl;
2093 /* Build a subtree of accesses rooted in *ACCESS, and move the pointer in the
2094 linked list along the way. Stop when *ACCESS is NULL or the access pointed
2095 to it is not "within" the root. Return false iff some accesses partially
2096 overlap. */
2098 static bool
2099 build_access_subtree (struct access **access)
2101 struct access *root = *access, *last_child = NULL;
2102 HOST_WIDE_INT limit = root->offset + root->size;
2104 *access = (*access)->next_grp;
2105 while (*access && (*access)->offset + (*access)->size <= limit)
2107 if (!last_child)
2108 root->first_child = *access;
2109 else
2110 last_child->next_sibling = *access;
2111 last_child = *access;
2113 if (!build_access_subtree (access))
2114 return false;
2117 if (*access && (*access)->offset < limit)
2118 return false;
2120 return true;
2123 /* Build a tree of access representatives, ACCESS is the pointer to the first
2124 one, others are linked in a list by the next_grp field. Return false iff
2125 some accesses partially overlap. */
2127 static bool
2128 build_access_trees (struct access *access)
2130 while (access)
2132 struct access *root = access;
2134 if (!build_access_subtree (&access))
2135 return false;
2136 root->next_grp = access;
2138 return true;
2141 /* Return true if expr contains some ARRAY_REFs into a variable bounded
2142 array. */
2144 static bool
2145 expr_with_var_bounded_array_refs_p (tree expr)
2147 while (handled_component_p (expr))
2149 if (TREE_CODE (expr) == ARRAY_REF
2150 && !tree_fits_shwi_p (array_ref_low_bound (expr)))
2151 return true;
2152 expr = TREE_OPERAND (expr, 0);
2154 return false;
2157 /* Analyze the subtree of accesses rooted in ROOT, scheduling replacements when
2158 both seeming beneficial and when ALLOW_REPLACEMENTS allows it. Also set all
2159 sorts of access flags appropriately along the way, notably always set
2160 grp_read and grp_assign_read according to MARK_READ and grp_write when
2161 MARK_WRITE is true.
2163 Creating a replacement for a scalar access is considered beneficial if its
2164 grp_hint is set (this means we are either attempting total scalarization or
2165 there is more than one direct read access) or according to the following
2166 table:
2168 Access written to through a scalar type (once or more times)
2170 | Written to in an assignment statement
2172 | | Access read as scalar _once_
2173 | | |
2174 | | | Read in an assignment statement
2175 | | | |
2176 | | | | Scalarize Comment
2177 -----------------------------------------------------------------------------
2178 0 0 0 0 No access for the scalar
2179 0 0 0 1 No access for the scalar
2180 0 0 1 0 No Single read - won't help
2181 0 0 1 1 No The same case
2182 0 1 0 0 No access for the scalar
2183 0 1 0 1 No access for the scalar
2184 0 1 1 0 Yes s = *g; return s.i;
2185 0 1 1 1 Yes The same case as above
2186 1 0 0 0 No Won't help
2187 1 0 0 1 Yes s.i = 1; *g = s;
2188 1 0 1 0 Yes s.i = 5; g = s.i;
2189 1 0 1 1 Yes The same case as above
2190 1 1 0 0 No Won't help.
2191 1 1 0 1 Yes s.i = 1; *g = s;
2192 1 1 1 0 Yes s = *g; return s.i;
2193 1 1 1 1 Yes Any of the above yeses */
2195 static bool
2196 analyze_access_subtree (struct access *root, struct access *parent,
2197 bool allow_replacements)
2199 struct access *child;
2200 HOST_WIDE_INT limit = root->offset + root->size;
2201 HOST_WIDE_INT covered_to = root->offset;
2202 bool scalar = is_gimple_reg_type (root->type);
2203 bool hole = false, sth_created = false;
2205 if (parent)
2207 if (parent->grp_read)
2208 root->grp_read = 1;
2209 if (parent->grp_assignment_read)
2210 root->grp_assignment_read = 1;
2211 if (parent->grp_write)
2212 root->grp_write = 1;
2213 if (parent->grp_assignment_write)
2214 root->grp_assignment_write = 1;
2215 if (parent->grp_total_scalarization)
2216 root->grp_total_scalarization = 1;
2219 if (root->grp_unscalarizable_region)
2220 allow_replacements = false;
2222 if (allow_replacements && expr_with_var_bounded_array_refs_p (root->expr))
2223 allow_replacements = false;
2225 for (child = root->first_child; child; child = child->next_sibling)
2227 hole |= covered_to < child->offset;
2228 sth_created |= analyze_access_subtree (child, root,
2229 allow_replacements && !scalar);
2231 root->grp_unscalarized_data |= child->grp_unscalarized_data;
2232 root->grp_total_scalarization &= child->grp_total_scalarization;
2233 if (child->grp_covered)
2234 covered_to += child->size;
2235 else
2236 hole = true;
2239 if (allow_replacements && scalar && !root->first_child
2240 && (root->grp_hint
2241 || ((root->grp_scalar_read || root->grp_assignment_read)
2242 && (root->grp_scalar_write || root->grp_assignment_write))))
2244 /* Always create access replacements that cover the whole access.
2245 For integral types this means the precision has to match.
2246 Avoid assumptions based on the integral type kind, too. */
2247 if (INTEGRAL_TYPE_P (root->type)
2248 && (TREE_CODE (root->type) != INTEGER_TYPE
2249 || TYPE_PRECISION (root->type) != root->size)
2250 /* But leave bitfield accesses alone. */
2251 && (TREE_CODE (root->expr) != COMPONENT_REF
2252 || !DECL_BIT_FIELD (TREE_OPERAND (root->expr, 1))))
2254 tree rt = root->type;
2255 gcc_assert ((root->offset % BITS_PER_UNIT) == 0
2256 && (root->size % BITS_PER_UNIT) == 0);
2257 root->type = build_nonstandard_integer_type (root->size,
2258 TYPE_UNSIGNED (rt));
2259 root->expr = build_ref_for_offset (UNKNOWN_LOCATION,
2260 root->base, root->offset,
2261 root->type, NULL, false);
2263 if (dump_file && (dump_flags & TDF_DETAILS))
2265 fprintf (dump_file, "Changing the type of a replacement for ");
2266 print_generic_expr (dump_file, root->base, 0);
2267 fprintf (dump_file, " offset: %u, size: %u ",
2268 (unsigned) root->offset, (unsigned) root->size);
2269 fprintf (dump_file, " to an integer.\n");
2273 root->grp_to_be_replaced = 1;
2274 root->replacement_decl = create_access_replacement (root);
2275 sth_created = true;
2276 hole = false;
2278 else
2280 if (allow_replacements
2281 && scalar && !root->first_child
2282 && (root->grp_scalar_write || root->grp_assignment_write)
2283 && !bitmap_bit_p (cannot_scalarize_away_bitmap,
2284 DECL_UID (root->base)))
2286 gcc_checking_assert (!root->grp_scalar_read
2287 && !root->grp_assignment_read);
2288 sth_created = true;
2289 if (MAY_HAVE_DEBUG_STMTS)
2291 root->grp_to_be_debug_replaced = 1;
2292 root->replacement_decl = create_access_replacement (root);
2296 if (covered_to < limit)
2297 hole = true;
2298 if (scalar)
2299 root->grp_total_scalarization = 0;
2302 if (!hole || root->grp_total_scalarization)
2303 root->grp_covered = 1;
2304 else if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
2305 root->grp_unscalarized_data = 1; /* not covered and written to */
2306 return sth_created;
2309 /* Analyze all access trees linked by next_grp by the means of
2310 analyze_access_subtree. */
2311 static bool
2312 analyze_access_trees (struct access *access)
2314 bool ret = false;
2316 while (access)
2318 if (analyze_access_subtree (access, NULL, true))
2319 ret = true;
2320 access = access->next_grp;
2323 return ret;
2326 /* Return true iff a potential new child of LACC at offset OFFSET and with size
2327 SIZE would conflict with an already existing one. If exactly such a child
2328 already exists in LACC, store a pointer to it in EXACT_MATCH. */
2330 static bool
2331 child_would_conflict_in_lacc (struct access *lacc, HOST_WIDE_INT norm_offset,
2332 HOST_WIDE_INT size, struct access **exact_match)
2334 struct access *child;
2336 for (child = lacc->first_child; child; child = child->next_sibling)
2338 if (child->offset == norm_offset && child->size == size)
2340 *exact_match = child;
2341 return true;
2344 if (child->offset < norm_offset + size
2345 && child->offset + child->size > norm_offset)
2346 return true;
2349 return false;
2352 /* Create a new child access of PARENT, with all properties just like MODEL
2353 except for its offset and with its grp_write false and grp_read true.
2354 Return the new access or NULL if it cannot be created. Note that this access
2355 is created long after all splicing and sorting, it's not located in any
2356 access vector and is automatically a representative of its group. */
2358 static struct access *
2359 create_artificial_child_access (struct access *parent, struct access *model,
2360 HOST_WIDE_INT new_offset)
2362 struct access *access;
2363 struct access **child;
2364 tree expr = parent->base;
2366 gcc_assert (!model->grp_unscalarizable_region);
2368 access = (struct access *) pool_alloc (access_pool);
2369 memset (access, 0, sizeof (struct access));
2370 if (!build_user_friendly_ref_for_offset (&expr, TREE_TYPE (expr), new_offset,
2371 model->type))
2373 access->grp_no_warning = true;
2374 expr = build_ref_for_model (EXPR_LOCATION (parent->base), parent->base,
2375 new_offset, model, NULL, false);
2378 access->base = parent->base;
2379 access->expr = expr;
2380 access->offset = new_offset;
2381 access->size = model->size;
2382 access->type = model->type;
2383 access->grp_write = true;
2384 access->grp_read = false;
2386 child = &parent->first_child;
2387 while (*child && (*child)->offset < new_offset)
2388 child = &(*child)->next_sibling;
2390 access->next_sibling = *child;
2391 *child = access;
2393 return access;
2397 /* Propagate all subaccesses of RACC across an assignment link to LACC. Return
2398 true if any new subaccess was created. Additionally, if RACC is a scalar
2399 access but LACC is not, change the type of the latter, if possible. */
2401 static bool
2402 propagate_subaccesses_across_link (struct access *lacc, struct access *racc)
2404 struct access *rchild;
2405 HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
2406 bool ret = false;
2408 if (is_gimple_reg_type (lacc->type)
2409 || lacc->grp_unscalarizable_region
2410 || racc->grp_unscalarizable_region)
2411 return false;
2413 if (is_gimple_reg_type (racc->type))
2415 if (!lacc->first_child && !racc->first_child)
2417 tree t = lacc->base;
2419 lacc->type = racc->type;
2420 if (build_user_friendly_ref_for_offset (&t, TREE_TYPE (t),
2421 lacc->offset, racc->type))
2422 lacc->expr = t;
2423 else
2425 lacc->expr = build_ref_for_model (EXPR_LOCATION (lacc->base),
2426 lacc->base, lacc->offset,
2427 racc, NULL, false);
2428 lacc->grp_no_warning = true;
2431 return false;
2434 for (rchild = racc->first_child; rchild; rchild = rchild->next_sibling)
2436 struct access *new_acc = NULL;
2437 HOST_WIDE_INT norm_offset = rchild->offset + norm_delta;
2439 if (rchild->grp_unscalarizable_region)
2440 continue;
2442 if (child_would_conflict_in_lacc (lacc, norm_offset, rchild->size,
2443 &new_acc))
2445 if (new_acc)
2447 rchild->grp_hint = 1;
2448 new_acc->grp_hint |= new_acc->grp_read;
2449 if (rchild->first_child)
2450 ret |= propagate_subaccesses_across_link (new_acc, rchild);
2452 continue;
2455 rchild->grp_hint = 1;
2456 new_acc = create_artificial_child_access (lacc, rchild, norm_offset);
2457 if (new_acc)
2459 ret = true;
2460 if (racc->first_child)
2461 propagate_subaccesses_across_link (new_acc, rchild);
2465 return ret;
2468 /* Propagate all subaccesses across assignment links. */
2470 static void
2471 propagate_all_subaccesses (void)
2473 while (work_queue_head)
2475 struct access *racc = pop_access_from_work_queue ();
2476 struct assign_link *link;
2478 gcc_assert (racc->first_link);
2480 for (link = racc->first_link; link; link = link->next)
2482 struct access *lacc = link->lacc;
2484 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (lacc->base)))
2485 continue;
2486 lacc = lacc->group_representative;
2487 if (propagate_subaccesses_across_link (lacc, racc)
2488 && lacc->first_link)
2489 add_access_to_work_queue (lacc);
2494 /* Go through all accesses collected throughout the (intraprocedural) analysis
2495 stage, exclude overlapping ones, identify representatives and build trees
2496 out of them, making decisions about scalarization on the way. Return true
2497 iff there are any to-be-scalarized variables after this stage. */
2499 static bool
2500 analyze_all_variable_accesses (void)
2502 int res = 0;
2503 bitmap tmp = BITMAP_ALLOC (NULL);
2504 bitmap_iterator bi;
2505 unsigned i, max_total_scalarization_size;
2507 max_total_scalarization_size = UNITS_PER_WORD * BITS_PER_UNIT
2508 * MOVE_RATIO (optimize_function_for_speed_p (cfun));
2510 EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
2511 if (bitmap_bit_p (should_scalarize_away_bitmap, i)
2512 && !bitmap_bit_p (cannot_scalarize_away_bitmap, i))
2514 tree var = candidate (i);
2516 if (TREE_CODE (var) == VAR_DECL
2517 && type_consists_of_records_p (TREE_TYPE (var)))
2519 if (tree_to_uhwi (TYPE_SIZE (TREE_TYPE (var)))
2520 <= max_total_scalarization_size)
2522 completely_scalarize_var (var);
2523 if (dump_file && (dump_flags & TDF_DETAILS))
2525 fprintf (dump_file, "Will attempt to totally scalarize ");
2526 print_generic_expr (dump_file, var, 0);
2527 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2530 else if (dump_file && (dump_flags & TDF_DETAILS))
2532 fprintf (dump_file, "Too big to totally scalarize: ");
2533 print_generic_expr (dump_file, var, 0);
2534 fprintf (dump_file, " (UID: %u)\n", DECL_UID (var));
2539 bitmap_copy (tmp, candidate_bitmap);
2540 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2542 tree var = candidate (i);
2543 struct access *access;
2545 access = sort_and_splice_var_accesses (var);
2546 if (!access || !build_access_trees (access))
2547 disqualify_candidate (var,
2548 "No or inhibitingly overlapping accesses.");
2551 propagate_all_subaccesses ();
2553 bitmap_copy (tmp, candidate_bitmap);
2554 EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi)
2556 tree var = candidate (i);
2557 struct access *access = get_first_repr_for_decl (var);
2559 if (analyze_access_trees (access))
2561 res++;
2562 if (dump_file && (dump_flags & TDF_DETAILS))
2564 fprintf (dump_file, "\nAccess trees for ");
2565 print_generic_expr (dump_file, var, 0);
2566 fprintf (dump_file, " (UID: %u): \n", DECL_UID (var));
2567 dump_access_tree (dump_file, access);
2568 fprintf (dump_file, "\n");
2571 else
2572 disqualify_candidate (var, "No scalar replacements to be created.");
2575 BITMAP_FREE (tmp);
2577 if (res)
2579 statistics_counter_event (cfun, "Scalarized aggregates", res);
2580 return true;
2582 else
2583 return false;
2586 /* Generate statements copying scalar replacements of accesses within a subtree
2587 into or out of AGG. ACCESS, all its children, siblings and their children
2588 are to be processed. AGG is an aggregate type expression (can be a
2589 declaration but does not have to be, it can for example also be a mem_ref or
2590 a series of handled components). TOP_OFFSET is the offset of the processed
2591 subtree which has to be subtracted from offsets of individual accesses to
2592 get corresponding offsets for AGG. If CHUNK_SIZE is non-null, copy only
2593 replacements in the interval <start_offset, start_offset + chunk_size>,
2594 otherwise copy all. GSI is a statement iterator used to place the new
2595 statements. WRITE should be true when the statements should write from AGG
2596 to the replacement and false if vice versa. if INSERT_AFTER is true, new
2597 statements will be added after the current statement in GSI, they will be
2598 added before the statement otherwise. */
2600 static void
2601 generate_subtree_copies (struct access *access, tree agg,
2602 HOST_WIDE_INT top_offset,
2603 HOST_WIDE_INT start_offset, HOST_WIDE_INT chunk_size,
2604 gimple_stmt_iterator *gsi, bool write,
2605 bool insert_after, location_t loc)
2609 if (chunk_size && access->offset >= start_offset + chunk_size)
2610 return;
2612 if (access->grp_to_be_replaced
2613 && (chunk_size == 0
2614 || access->offset + access->size > start_offset))
2616 tree expr, repl = get_access_replacement (access);
2617 gimple stmt;
2619 expr = build_ref_for_model (loc, agg, access->offset - top_offset,
2620 access, gsi, insert_after);
2622 if (write)
2624 if (access->grp_partial_lhs)
2625 expr = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE,
2626 !insert_after,
2627 insert_after ? GSI_NEW_STMT
2628 : GSI_SAME_STMT);
2629 stmt = gimple_build_assign (repl, expr);
2631 else
2633 TREE_NO_WARNING (repl) = 1;
2634 if (access->grp_partial_lhs)
2635 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2636 !insert_after,
2637 insert_after ? GSI_NEW_STMT
2638 : GSI_SAME_STMT);
2639 stmt = gimple_build_assign (expr, repl);
2641 gimple_set_location (stmt, loc);
2643 if (insert_after)
2644 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2645 else
2646 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2647 update_stmt (stmt);
2648 sra_stats.subtree_copies++;
2650 else if (write
2651 && access->grp_to_be_debug_replaced
2652 && (chunk_size == 0
2653 || access->offset + access->size > start_offset))
2655 gimple ds;
2656 tree drhs = build_debug_ref_for_model (loc, agg,
2657 access->offset - top_offset,
2658 access);
2659 ds = gimple_build_debug_bind (get_access_replacement (access),
2660 drhs, gsi_stmt (*gsi));
2661 if (insert_after)
2662 gsi_insert_after (gsi, ds, GSI_NEW_STMT);
2663 else
2664 gsi_insert_before (gsi, ds, GSI_SAME_STMT);
2667 if (access->first_child)
2668 generate_subtree_copies (access->first_child, agg, top_offset,
2669 start_offset, chunk_size, gsi,
2670 write, insert_after, loc);
2672 access = access->next_sibling;
2674 while (access);
2677 /* Assign zero to all scalar replacements in an access subtree. ACCESS is the
2678 the root of the subtree to be processed. GSI is the statement iterator used
2679 for inserting statements which are added after the current statement if
2680 INSERT_AFTER is true or before it otherwise. */
2682 static void
2683 init_subtree_with_zero (struct access *access, gimple_stmt_iterator *gsi,
2684 bool insert_after, location_t loc)
2687 struct access *child;
2689 if (access->grp_to_be_replaced)
2691 gimple stmt;
2693 stmt = gimple_build_assign (get_access_replacement (access),
2694 build_zero_cst (access->type));
2695 if (insert_after)
2696 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2697 else
2698 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2699 update_stmt (stmt);
2700 gimple_set_location (stmt, loc);
2702 else if (access->grp_to_be_debug_replaced)
2704 gimple ds = gimple_build_debug_bind (get_access_replacement (access),
2705 build_zero_cst (access->type),
2706 gsi_stmt (*gsi));
2707 if (insert_after)
2708 gsi_insert_after (gsi, ds, GSI_NEW_STMT);
2709 else
2710 gsi_insert_before (gsi, ds, GSI_SAME_STMT);
2713 for (child = access->first_child; child; child = child->next_sibling)
2714 init_subtree_with_zero (child, gsi, insert_after, loc);
2717 /* Search for an access representative for the given expression EXPR and
2718 return it or NULL if it cannot be found. */
2720 static struct access *
2721 get_access_for_expr (tree expr)
2723 HOST_WIDE_INT offset, size, max_size;
2724 tree base;
2726 /* FIXME: This should not be necessary but Ada produces V_C_Es with a type of
2727 a different size than the size of its argument and we need the latter
2728 one. */
2729 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
2730 expr = TREE_OPERAND (expr, 0);
2732 base = get_ref_base_and_extent (expr, &offset, &size, &max_size);
2733 if (max_size == -1 || !DECL_P (base))
2734 return NULL;
2736 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (base)))
2737 return NULL;
2739 return get_var_base_offset_size_access (base, offset, max_size);
2742 /* Replace the expression EXPR with a scalar replacement if there is one and
2743 generate other statements to do type conversion or subtree copying if
2744 necessary. GSI is used to place newly created statements, WRITE is true if
2745 the expression is being written to (it is on a LHS of a statement or output
2746 in an assembly statement). */
2748 static bool
2749 sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write)
2751 location_t loc;
2752 struct access *access;
2753 tree type, bfr;
2755 if (TREE_CODE (*expr) == BIT_FIELD_REF)
2757 bfr = *expr;
2758 expr = &TREE_OPERAND (*expr, 0);
2760 else
2761 bfr = NULL_TREE;
2763 if (TREE_CODE (*expr) == REALPART_EXPR || TREE_CODE (*expr) == IMAGPART_EXPR)
2764 expr = &TREE_OPERAND (*expr, 0);
2765 access = get_access_for_expr (*expr);
2766 if (!access)
2767 return false;
2768 type = TREE_TYPE (*expr);
2770 loc = gimple_location (gsi_stmt (*gsi));
2771 if (access->grp_to_be_replaced)
2773 tree repl = get_access_replacement (access);
2774 /* If we replace a non-register typed access simply use the original
2775 access expression to extract the scalar component afterwards.
2776 This happens if scalarizing a function return value or parameter
2777 like in gcc.c-torture/execute/20041124-1.c, 20050316-1.c and
2778 gcc.c-torture/compile/20011217-1.c.
2780 We also want to use this when accessing a complex or vector which can
2781 be accessed as a different type too, potentially creating a need for
2782 type conversion (see PR42196) and when scalarized unions are involved
2783 in assembler statements (see PR42398). */
2784 if (!useless_type_conversion_p (type, access->type))
2786 tree ref;
2788 ref = build_ref_for_model (loc, access->base, access->offset, access,
2789 NULL, false);
2791 if (write)
2793 gimple stmt;
2795 if (access->grp_partial_lhs)
2796 ref = force_gimple_operand_gsi (gsi, ref, true, NULL_TREE,
2797 false, GSI_NEW_STMT);
2798 stmt = gimple_build_assign (repl, ref);
2799 gimple_set_location (stmt, loc);
2800 gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
2802 else
2804 gimple stmt;
2806 if (access->grp_partial_lhs)
2807 repl = force_gimple_operand_gsi (gsi, repl, true, NULL_TREE,
2808 true, GSI_SAME_STMT);
2809 stmt = gimple_build_assign (ref, repl);
2810 gimple_set_location (stmt, loc);
2811 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
2814 else
2815 *expr = repl;
2816 sra_stats.exprs++;
2818 else if (write && access->grp_to_be_debug_replaced)
2820 gimple ds = gimple_build_debug_bind (get_access_replacement (access),
2821 NULL_TREE,
2822 gsi_stmt (*gsi));
2823 gsi_insert_after (gsi, ds, GSI_NEW_STMT);
2826 if (access->first_child)
2828 HOST_WIDE_INT start_offset, chunk_size;
2829 if (bfr
2830 && tree_fits_uhwi_p (TREE_OPERAND (bfr, 1))
2831 && tree_fits_uhwi_p (TREE_OPERAND (bfr, 2)))
2833 chunk_size = tree_to_uhwi (TREE_OPERAND (bfr, 1));
2834 start_offset = access->offset
2835 + tree_to_uhwi (TREE_OPERAND (bfr, 2));
2837 else
2838 start_offset = chunk_size = 0;
2840 generate_subtree_copies (access->first_child, access->base, 0,
2841 start_offset, chunk_size, gsi, write, write,
2842 loc);
2844 return true;
2847 /* Where scalar replacements of the RHS have been written to when a replacement
2848 of a LHS of an assigments cannot be direclty loaded from a replacement of
2849 the RHS. */
2850 enum unscalarized_data_handling { SRA_UDH_NONE, /* Nothing done so far. */
2851 SRA_UDH_RIGHT, /* Data flushed to the RHS. */
2852 SRA_UDH_LEFT }; /* Data flushed to the LHS. */
2854 /* Store all replacements in the access tree rooted in TOP_RACC either to their
2855 base aggregate if there are unscalarized data or directly to LHS of the
2856 statement that is pointed to by GSI otherwise. */
2858 static enum unscalarized_data_handling
2859 handle_unscalarized_data_in_subtree (struct access *top_racc,
2860 gimple_stmt_iterator *gsi)
2862 if (top_racc->grp_unscalarized_data)
2864 generate_subtree_copies (top_racc->first_child, top_racc->base, 0, 0, 0,
2865 gsi, false, false,
2866 gimple_location (gsi_stmt (*gsi)));
2867 return SRA_UDH_RIGHT;
2869 else
2871 tree lhs = gimple_assign_lhs (gsi_stmt (*gsi));
2872 generate_subtree_copies (top_racc->first_child, lhs, top_racc->offset,
2873 0, 0, gsi, false, false,
2874 gimple_location (gsi_stmt (*gsi)));
2875 return SRA_UDH_LEFT;
2880 /* Try to generate statements to load all sub-replacements in an access subtree
2881 formed by children of LACC from scalar replacements in the TOP_RACC subtree.
2882 If that is not possible, refresh the TOP_RACC base aggregate and load the
2883 accesses from it. LEFT_OFFSET is the offset of the left whole subtree being
2884 copied. NEW_GSI is stmt iterator used for statement insertions after the
2885 original assignment, OLD_GSI is used to insert statements before the
2886 assignment. *REFRESHED keeps the information whether we have needed to
2887 refresh replacements of the LHS and from which side of the assignments this
2888 takes place. */
2890 static void
2891 load_assign_lhs_subreplacements (struct access *lacc, struct access *top_racc,
2892 HOST_WIDE_INT left_offset,
2893 gimple_stmt_iterator *old_gsi,
2894 gimple_stmt_iterator *new_gsi,
2895 enum unscalarized_data_handling *refreshed)
2897 location_t loc = gimple_location (gsi_stmt (*old_gsi));
2898 for (lacc = lacc->first_child; lacc; lacc = lacc->next_sibling)
2900 HOST_WIDE_INT offset = lacc->offset - left_offset + top_racc->offset;
2902 if (lacc->grp_to_be_replaced)
2904 struct access *racc;
2905 gimple stmt;
2906 tree rhs;
2908 racc = find_access_in_subtree (top_racc, offset, lacc->size);
2909 if (racc && racc->grp_to_be_replaced)
2911 rhs = get_access_replacement (racc);
2912 if (!useless_type_conversion_p (lacc->type, racc->type))
2913 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, lacc->type, rhs);
2915 if (racc->grp_partial_lhs && lacc->grp_partial_lhs)
2916 rhs = force_gimple_operand_gsi (old_gsi, rhs, true, NULL_TREE,
2917 true, GSI_SAME_STMT);
2919 else
2921 /* No suitable access on the right hand side, need to load from
2922 the aggregate. See if we have to update it first... */
2923 if (*refreshed == SRA_UDH_NONE)
2924 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2925 old_gsi);
2927 if (*refreshed == SRA_UDH_LEFT)
2928 rhs = build_ref_for_model (loc, lacc->base, lacc->offset, lacc,
2929 new_gsi, true);
2930 else
2931 rhs = build_ref_for_model (loc, top_racc->base, offset, lacc,
2932 new_gsi, true);
2933 if (lacc->grp_partial_lhs)
2934 rhs = force_gimple_operand_gsi (new_gsi, rhs, true, NULL_TREE,
2935 false, GSI_NEW_STMT);
2938 stmt = gimple_build_assign (get_access_replacement (lacc), rhs);
2939 gsi_insert_after (new_gsi, stmt, GSI_NEW_STMT);
2940 gimple_set_location (stmt, loc);
2941 update_stmt (stmt);
2942 sra_stats.subreplacements++;
2944 else
2946 if (*refreshed == SRA_UDH_NONE
2947 && lacc->grp_read && !lacc->grp_covered)
2948 *refreshed = handle_unscalarized_data_in_subtree (top_racc,
2949 old_gsi);
2950 if (lacc && lacc->grp_to_be_debug_replaced)
2952 gimple ds;
2953 tree drhs;
2954 struct access *racc = find_access_in_subtree (top_racc, offset,
2955 lacc->size);
2957 if (racc && racc->grp_to_be_replaced)
2959 if (racc->grp_write)
2960 drhs = get_access_replacement (racc);
2961 else
2962 drhs = NULL;
2964 else if (*refreshed == SRA_UDH_LEFT)
2965 drhs = build_debug_ref_for_model (loc, lacc->base, lacc->offset,
2966 lacc);
2967 else if (*refreshed == SRA_UDH_RIGHT)
2968 drhs = build_debug_ref_for_model (loc, top_racc->base, offset,
2969 lacc);
2970 else
2971 drhs = NULL_TREE;
2972 if (drhs
2973 && !useless_type_conversion_p (lacc->type, TREE_TYPE (drhs)))
2974 drhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR,
2975 lacc->type, drhs);
2976 ds = gimple_build_debug_bind (get_access_replacement (lacc),
2977 drhs, gsi_stmt (*old_gsi));
2978 gsi_insert_after (new_gsi, ds, GSI_NEW_STMT);
2982 if (lacc->first_child)
2983 load_assign_lhs_subreplacements (lacc, top_racc, left_offset,
2984 old_gsi, new_gsi, refreshed);
2988 /* Result code for SRA assignment modification. */
2989 enum assignment_mod_result { SRA_AM_NONE, /* nothing done for the stmt */
2990 SRA_AM_MODIFIED, /* stmt changed but not
2991 removed */
2992 SRA_AM_REMOVED }; /* stmt eliminated */
2994 /* Modify assignments with a CONSTRUCTOR on their RHS. STMT contains a pointer
2995 to the assignment and GSI is the statement iterator pointing at it. Returns
2996 the same values as sra_modify_assign. */
2998 static enum assignment_mod_result
2999 sra_modify_constructor_assign (gimple *stmt, gimple_stmt_iterator *gsi)
3001 tree lhs = gimple_assign_lhs (*stmt);
3002 struct access *acc;
3003 location_t loc;
3005 acc = get_access_for_expr (lhs);
3006 if (!acc)
3007 return SRA_AM_NONE;
3009 if (gimple_clobber_p (*stmt))
3011 /* Remove clobbers of fully scalarized variables, otherwise
3012 do nothing. */
3013 if (acc->grp_covered)
3015 unlink_stmt_vdef (*stmt);
3016 gsi_remove (gsi, true);
3017 release_defs (*stmt);
3018 return SRA_AM_REMOVED;
3020 else
3021 return SRA_AM_NONE;
3024 loc = gimple_location (*stmt);
3025 if (vec_safe_length (CONSTRUCTOR_ELTS (gimple_assign_rhs1 (*stmt))) > 0)
3027 /* I have never seen this code path trigger but if it can happen the
3028 following should handle it gracefully. */
3029 if (access_has_children_p (acc))
3030 generate_subtree_copies (acc->first_child, acc->base, 0, 0, 0, gsi,
3031 true, true, loc);
3032 return SRA_AM_MODIFIED;
3035 if (acc->grp_covered)
3037 init_subtree_with_zero (acc, gsi, false, loc);
3038 unlink_stmt_vdef (*stmt);
3039 gsi_remove (gsi, true);
3040 release_defs (*stmt);
3041 return SRA_AM_REMOVED;
3043 else
3045 init_subtree_with_zero (acc, gsi, true, loc);
3046 return SRA_AM_MODIFIED;
3050 /* Create and return a new suitable default definition SSA_NAME for RACC which
3051 is an access describing an uninitialized part of an aggregate that is being
3052 loaded. */
3054 static tree
3055 get_repl_default_def_ssa_name (struct access *racc)
3057 gcc_checking_assert (!racc->grp_to_be_replaced
3058 && !racc->grp_to_be_debug_replaced);
3059 if (!racc->replacement_decl)
3060 racc->replacement_decl = create_access_replacement (racc);
3061 return get_or_create_ssa_default_def (cfun, racc->replacement_decl);
3064 /* Return true if REF has an VIEW_CONVERT_EXPR or a COMPONENT_REF with a
3065 bit-field field declaration somewhere in it. */
3067 static inline bool
3068 contains_vce_or_bfcref_p (const_tree ref)
3070 while (handled_component_p (ref))
3072 if (TREE_CODE (ref) == VIEW_CONVERT_EXPR
3073 || (TREE_CODE (ref) == COMPONENT_REF
3074 && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))))
3075 return true;
3076 ref = TREE_OPERAND (ref, 0);
3079 return false;
3082 /* Examine both sides of the assignment statement pointed to by STMT, replace
3083 them with a scalare replacement if there is one and generate copying of
3084 replacements if scalarized aggregates have been used in the assignment. GSI
3085 is used to hold generated statements for type conversions and subtree
3086 copying. */
3088 static enum assignment_mod_result
3089 sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
3091 struct access *lacc, *racc;
3092 tree lhs, rhs;
3093 bool modify_this_stmt = false;
3094 bool force_gimple_rhs = false;
3095 location_t loc;
3096 gimple_stmt_iterator orig_gsi = *gsi;
3098 if (!gimple_assign_single_p (*stmt))
3099 return SRA_AM_NONE;
3100 lhs = gimple_assign_lhs (*stmt);
3101 rhs = gimple_assign_rhs1 (*stmt);
3103 if (TREE_CODE (rhs) == CONSTRUCTOR)
3104 return sra_modify_constructor_assign (stmt, gsi);
3106 if (TREE_CODE (rhs) == REALPART_EXPR || TREE_CODE (lhs) == REALPART_EXPR
3107 || TREE_CODE (rhs) == IMAGPART_EXPR || TREE_CODE (lhs) == IMAGPART_EXPR
3108 || TREE_CODE (rhs) == BIT_FIELD_REF || TREE_CODE (lhs) == BIT_FIELD_REF)
3110 modify_this_stmt = sra_modify_expr (gimple_assign_rhs1_ptr (*stmt),
3111 gsi, false);
3112 modify_this_stmt |= sra_modify_expr (gimple_assign_lhs_ptr (*stmt),
3113 gsi, true);
3114 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3117 lacc = get_access_for_expr (lhs);
3118 racc = get_access_for_expr (rhs);
3119 if (!lacc && !racc)
3120 return SRA_AM_NONE;
3122 loc = gimple_location (*stmt);
3123 if (lacc && lacc->grp_to_be_replaced)
3125 lhs = get_access_replacement (lacc);
3126 gimple_assign_set_lhs (*stmt, lhs);
3127 modify_this_stmt = true;
3128 if (lacc->grp_partial_lhs)
3129 force_gimple_rhs = true;
3130 sra_stats.exprs++;
3133 if (racc && racc->grp_to_be_replaced)
3135 rhs = get_access_replacement (racc);
3136 modify_this_stmt = true;
3137 if (racc->grp_partial_lhs)
3138 force_gimple_rhs = true;
3139 sra_stats.exprs++;
3141 else if (racc
3142 && !racc->grp_unscalarized_data
3143 && TREE_CODE (lhs) == SSA_NAME
3144 && !access_has_replacements_p (racc))
3146 rhs = get_repl_default_def_ssa_name (racc);
3147 modify_this_stmt = true;
3148 sra_stats.exprs++;
3151 if (modify_this_stmt)
3153 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
3155 /* If we can avoid creating a VIEW_CONVERT_EXPR do so.
3156 ??? This should move to fold_stmt which we simply should
3157 call after building a VIEW_CONVERT_EXPR here. */
3158 if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
3159 && !contains_bitfld_component_ref_p (lhs))
3161 lhs = build_ref_for_model (loc, lhs, 0, racc, gsi, false);
3162 gimple_assign_set_lhs (*stmt, lhs);
3164 else if (AGGREGATE_TYPE_P (TREE_TYPE (rhs))
3165 && !contains_vce_or_bfcref_p (rhs))
3166 rhs = build_ref_for_model (loc, rhs, 0, lacc, gsi, false);
3168 if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
3170 rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR, TREE_TYPE (lhs),
3171 rhs);
3172 if (is_gimple_reg_type (TREE_TYPE (lhs))
3173 && TREE_CODE (lhs) != SSA_NAME)
3174 force_gimple_rhs = true;
3179 if (lacc && lacc->grp_to_be_debug_replaced)
3181 tree dlhs = get_access_replacement (lacc);
3182 tree drhs = unshare_expr (rhs);
3183 if (!useless_type_conversion_p (TREE_TYPE (dlhs), TREE_TYPE (drhs)))
3185 if (AGGREGATE_TYPE_P (TREE_TYPE (drhs))
3186 && !contains_vce_or_bfcref_p (drhs))
3187 drhs = build_debug_ref_for_model (loc, drhs, 0, lacc);
3188 if (drhs
3189 && !useless_type_conversion_p (TREE_TYPE (dlhs),
3190 TREE_TYPE (drhs)))
3191 drhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR,
3192 TREE_TYPE (dlhs), drhs);
3194 gimple ds = gimple_build_debug_bind (dlhs, drhs, *stmt);
3195 gsi_insert_before (gsi, ds, GSI_SAME_STMT);
3198 /* From this point on, the function deals with assignments in between
3199 aggregates when at least one has scalar reductions of some of its
3200 components. There are three possible scenarios: Both the LHS and RHS have
3201 to-be-scalarized components, 2) only the RHS has or 3) only the LHS has.
3203 In the first case, we would like to load the LHS components from RHS
3204 components whenever possible. If that is not possible, we would like to
3205 read it directly from the RHS (after updating it by storing in it its own
3206 components). If there are some necessary unscalarized data in the LHS,
3207 those will be loaded by the original assignment too. If neither of these
3208 cases happen, the original statement can be removed. Most of this is done
3209 by load_assign_lhs_subreplacements.
3211 In the second case, we would like to store all RHS scalarized components
3212 directly into LHS and if they cover the aggregate completely, remove the
3213 statement too. In the third case, we want the LHS components to be loaded
3214 directly from the RHS (DSE will remove the original statement if it
3215 becomes redundant).
3217 This is a bit complex but manageable when types match and when unions do
3218 not cause confusion in a way that we cannot really load a component of LHS
3219 from the RHS or vice versa (the access representing this level can have
3220 subaccesses that are accessible only through a different union field at a
3221 higher level - different from the one used in the examined expression).
3222 Unions are fun.
3224 Therefore, I specially handle a fourth case, happening when there is a
3225 specific type cast or it is impossible to locate a scalarized subaccess on
3226 the other side of the expression. If that happens, I simply "refresh" the
3227 RHS by storing in it is scalarized components leave the original statement
3228 there to do the copying and then load the scalar replacements of the LHS.
3229 This is what the first branch does. */
3231 if (modify_this_stmt
3232 || gimple_has_volatile_ops (*stmt)
3233 || contains_vce_or_bfcref_p (rhs)
3234 || contains_vce_or_bfcref_p (lhs))
3236 if (access_has_children_p (racc))
3237 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
3238 gsi, false, false, loc);
3239 if (access_has_children_p (lacc))
3240 generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
3241 gsi, true, true, loc);
3242 sra_stats.separate_lhs_rhs_handling++;
3244 /* This gimplification must be done after generate_subtree_copies,
3245 lest we insert the subtree copies in the middle of the gimplified
3246 sequence. */
3247 if (force_gimple_rhs)
3248 rhs = force_gimple_operand_gsi (&orig_gsi, rhs, true, NULL_TREE,
3249 true, GSI_SAME_STMT);
3250 if (gimple_assign_rhs1 (*stmt) != rhs)
3252 modify_this_stmt = true;
3253 gimple_assign_set_rhs_from_tree (&orig_gsi, rhs);
3254 gcc_assert (*stmt == gsi_stmt (orig_gsi));
3257 return modify_this_stmt ? SRA_AM_MODIFIED : SRA_AM_NONE;
3259 else
3261 if (access_has_children_p (lacc)
3262 && access_has_children_p (racc)
3263 /* When an access represents an unscalarizable region, it usually
3264 represents accesses with variable offset and thus must not be used
3265 to generate new memory accesses. */
3266 && !lacc->grp_unscalarizable_region
3267 && !racc->grp_unscalarizable_region)
3269 gimple_stmt_iterator orig_gsi = *gsi;
3270 enum unscalarized_data_handling refreshed;
3272 if (lacc->grp_read && !lacc->grp_covered)
3273 refreshed = handle_unscalarized_data_in_subtree (racc, gsi);
3274 else
3275 refreshed = SRA_UDH_NONE;
3277 load_assign_lhs_subreplacements (lacc, racc, lacc->offset,
3278 &orig_gsi, gsi, &refreshed);
3279 if (refreshed != SRA_UDH_RIGHT)
3281 gsi_next (gsi);
3282 unlink_stmt_vdef (*stmt);
3283 gsi_remove (&orig_gsi, true);
3284 release_defs (*stmt);
3285 sra_stats.deleted++;
3286 return SRA_AM_REMOVED;
3289 else
3291 if (access_has_children_p (racc)
3292 && !racc->grp_unscalarized_data)
3294 if (dump_file)
3296 fprintf (dump_file, "Removing load: ");
3297 print_gimple_stmt (dump_file, *stmt, 0, 0);
3299 generate_subtree_copies (racc->first_child, lhs,
3300 racc->offset, 0, 0, gsi,
3301 false, false, loc);
3302 gcc_assert (*stmt == gsi_stmt (*gsi));
3303 unlink_stmt_vdef (*stmt);
3304 gsi_remove (gsi, true);
3305 release_defs (*stmt);
3306 sra_stats.deleted++;
3307 return SRA_AM_REMOVED;
3309 /* Restore the aggregate RHS from its components so the
3310 prevailing aggregate copy does the right thing. */
3311 if (access_has_children_p (racc))
3312 generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
3313 gsi, false, false, loc);
3314 /* Re-load the components of the aggregate copy destination.
3315 But use the RHS aggregate to load from to expose more
3316 optimization opportunities. */
3317 if (access_has_children_p (lacc))
3318 generate_subtree_copies (lacc->first_child, rhs, lacc->offset,
3319 0, 0, gsi, true, true, loc);
3322 return SRA_AM_NONE;
3326 /* Traverse the function body and all modifications as decided in
3327 analyze_all_variable_accesses. Return true iff the CFG has been
3328 changed. */
3330 static bool
3331 sra_modify_function_body (void)
3333 bool cfg_changed = false;
3334 basic_block bb;
3336 FOR_EACH_BB_FN (bb, cfun)
3338 gimple_stmt_iterator gsi = gsi_start_bb (bb);
3339 while (!gsi_end_p (gsi))
3341 gimple stmt = gsi_stmt (gsi);
3342 enum assignment_mod_result assign_result;
3343 bool modified = false, deleted = false;
3344 tree *t;
3345 unsigned i;
3347 switch (gimple_code (stmt))
3349 case GIMPLE_RETURN:
3350 t = gimple_return_retval_ptr (stmt);
3351 if (*t != NULL_TREE)
3352 modified |= sra_modify_expr (t, &gsi, false);
3353 break;
3355 case GIMPLE_ASSIGN:
3356 assign_result = sra_modify_assign (&stmt, &gsi);
3357 modified |= assign_result == SRA_AM_MODIFIED;
3358 deleted = assign_result == SRA_AM_REMOVED;
3359 break;
3361 case GIMPLE_CALL:
3362 /* Operands must be processed before the lhs. */
3363 for (i = 0; i < gimple_call_num_args (stmt); i++)
3365 t = gimple_call_arg_ptr (stmt, i);
3366 modified |= sra_modify_expr (t, &gsi, false);
3369 if (gimple_call_lhs (stmt))
3371 t = gimple_call_lhs_ptr (stmt);
3372 modified |= sra_modify_expr (t, &gsi, true);
3374 break;
3376 case GIMPLE_ASM:
3377 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
3379 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
3380 modified |= sra_modify_expr (t, &gsi, false);
3382 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
3384 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
3385 modified |= sra_modify_expr (t, &gsi, true);
3387 break;
3389 default:
3390 break;
3393 if (modified)
3395 update_stmt (stmt);
3396 if (maybe_clean_eh_stmt (stmt)
3397 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
3398 cfg_changed = true;
3400 if (!deleted)
3401 gsi_next (&gsi);
3405 return cfg_changed;
3408 /* Generate statements initializing scalar replacements of parts of function
3409 parameters. */
3411 static void
3412 initialize_parameter_reductions (void)
3414 gimple_stmt_iterator gsi;
3415 gimple_seq seq = NULL;
3416 tree parm;
3418 gsi = gsi_start (seq);
3419 for (parm = DECL_ARGUMENTS (current_function_decl);
3420 parm;
3421 parm = DECL_CHAIN (parm))
3423 vec<access_p> *access_vec;
3424 struct access *access;
3426 if (!bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
3427 continue;
3428 access_vec = get_base_access_vector (parm);
3429 if (!access_vec)
3430 continue;
3432 for (access = (*access_vec)[0];
3433 access;
3434 access = access->next_grp)
3435 generate_subtree_copies (access, parm, 0, 0, 0, &gsi, true, true,
3436 EXPR_LOCATION (parm));
3439 seq = gsi_seq (gsi);
3440 if (seq)
3441 gsi_insert_seq_on_edge_immediate (single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)), seq);
3444 /* The "main" function of intraprocedural SRA passes. Runs the analysis and if
3445 it reveals there are components of some aggregates to be scalarized, it runs
3446 the required transformations. */
3447 static unsigned int
3448 perform_intra_sra (void)
3450 int ret = 0;
3451 sra_initialize ();
3453 if (!find_var_candidates ())
3454 goto out;
3456 if (!scan_function ())
3457 goto out;
3459 if (!analyze_all_variable_accesses ())
3460 goto out;
3462 if (sra_modify_function_body ())
3463 ret = TODO_update_ssa | TODO_cleanup_cfg;
3464 else
3465 ret = TODO_update_ssa;
3466 initialize_parameter_reductions ();
3468 statistics_counter_event (cfun, "Scalar replacements created",
3469 sra_stats.replacements);
3470 statistics_counter_event (cfun, "Modified expressions", sra_stats.exprs);
3471 statistics_counter_event (cfun, "Subtree copy stmts",
3472 sra_stats.subtree_copies);
3473 statistics_counter_event (cfun, "Subreplacement stmts",
3474 sra_stats.subreplacements);
3475 statistics_counter_event (cfun, "Deleted stmts", sra_stats.deleted);
3476 statistics_counter_event (cfun, "Separate LHS and RHS handling",
3477 sra_stats.separate_lhs_rhs_handling);
3479 out:
3480 sra_deinitialize ();
3481 return ret;
3484 /* Perform early intraprocedural SRA. */
3485 static unsigned int
3486 early_intra_sra (void)
3488 sra_mode = SRA_MODE_EARLY_INTRA;
3489 return perform_intra_sra ();
3492 /* Perform "late" intraprocedural SRA. */
3493 static unsigned int
3494 late_intra_sra (void)
3496 sra_mode = SRA_MODE_INTRA;
3497 return perform_intra_sra ();
3501 static bool
3502 gate_intra_sra (void)
3504 return flag_tree_sra != 0 && dbg_cnt (tree_sra);
3508 namespace {
3510 const pass_data pass_data_sra_early =
3512 GIMPLE_PASS, /* type */
3513 "esra", /* name */
3514 OPTGROUP_NONE, /* optinfo_flags */
3515 true, /* has_gate */
3516 true, /* has_execute */
3517 TV_TREE_SRA, /* tv_id */
3518 ( PROP_cfg | PROP_ssa ), /* properties_required */
3519 0, /* properties_provided */
3520 0, /* properties_destroyed */
3521 0, /* todo_flags_start */
3522 ( TODO_update_ssa | TODO_verify_ssa ), /* todo_flags_finish */
3525 class pass_sra_early : public gimple_opt_pass
3527 public:
3528 pass_sra_early (gcc::context *ctxt)
3529 : gimple_opt_pass (pass_data_sra_early, ctxt)
3532 /* opt_pass methods: */
3533 bool gate () { return gate_intra_sra (); }
3534 unsigned int execute () { return early_intra_sra (); }
3536 }; // class pass_sra_early
3538 } // anon namespace
3540 gimple_opt_pass *
3541 make_pass_sra_early (gcc::context *ctxt)
3543 return new pass_sra_early (ctxt);
3546 namespace {
3548 const pass_data pass_data_sra =
3550 GIMPLE_PASS, /* type */
3551 "sra", /* name */
3552 OPTGROUP_NONE, /* optinfo_flags */
3553 true, /* has_gate */
3554 true, /* has_execute */
3555 TV_TREE_SRA, /* tv_id */
3556 ( PROP_cfg | PROP_ssa ), /* properties_required */
3557 0, /* properties_provided */
3558 0, /* properties_destroyed */
3559 TODO_update_address_taken, /* todo_flags_start */
3560 ( TODO_update_ssa | TODO_verify_ssa ), /* todo_flags_finish */
3563 class pass_sra : public gimple_opt_pass
3565 public:
3566 pass_sra (gcc::context *ctxt)
3567 : gimple_opt_pass (pass_data_sra, ctxt)
3570 /* opt_pass methods: */
3571 bool gate () { return gate_intra_sra (); }
3572 unsigned int execute () { return late_intra_sra (); }
3574 }; // class pass_sra
3576 } // anon namespace
3578 gimple_opt_pass *
3579 make_pass_sra (gcc::context *ctxt)
3581 return new pass_sra (ctxt);
3585 /* Return true iff PARM (which must be a parm_decl) is an unused scalar
3586 parameter. */
3588 static bool
3589 is_unused_scalar_param (tree parm)
3591 tree name;
3592 return (is_gimple_reg (parm)
3593 && (!(name = ssa_default_def (cfun, parm))
3594 || has_zero_uses (name)));
3597 /* Scan immediate uses of a default definition SSA name of a parameter PARM and
3598 examine whether there are any direct or otherwise infeasible ones. If so,
3599 return true, otherwise return false. PARM must be a gimple register with a
3600 non-NULL default definition. */
3602 static bool
3603 ptr_parm_has_direct_uses (tree parm)
3605 imm_use_iterator ui;
3606 gimple stmt;
3607 tree name = ssa_default_def (cfun, parm);
3608 bool ret = false;
3610 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
3612 int uses_ok = 0;
3613 use_operand_p use_p;
3615 if (is_gimple_debug (stmt))
3616 continue;
3618 /* Valid uses include dereferences on the lhs and the rhs. */
3619 if (gimple_has_lhs (stmt))
3621 tree lhs = gimple_get_lhs (stmt);
3622 while (handled_component_p (lhs))
3623 lhs = TREE_OPERAND (lhs, 0);
3624 if (TREE_CODE (lhs) == MEM_REF
3625 && TREE_OPERAND (lhs, 0) == name
3626 && integer_zerop (TREE_OPERAND (lhs, 1))
3627 && types_compatible_p (TREE_TYPE (lhs),
3628 TREE_TYPE (TREE_TYPE (name)))
3629 && !TREE_THIS_VOLATILE (lhs))
3630 uses_ok++;
3632 if (gimple_assign_single_p (stmt))
3634 tree rhs = gimple_assign_rhs1 (stmt);
3635 while (handled_component_p (rhs))
3636 rhs = TREE_OPERAND (rhs, 0);
3637 if (TREE_CODE (rhs) == MEM_REF
3638 && TREE_OPERAND (rhs, 0) == name
3639 && integer_zerop (TREE_OPERAND (rhs, 1))
3640 && types_compatible_p (TREE_TYPE (rhs),
3641 TREE_TYPE (TREE_TYPE (name)))
3642 && !TREE_THIS_VOLATILE (rhs))
3643 uses_ok++;
3645 else if (is_gimple_call (stmt))
3647 unsigned i;
3648 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3650 tree arg = gimple_call_arg (stmt, i);
3651 while (handled_component_p (arg))
3652 arg = TREE_OPERAND (arg, 0);
3653 if (TREE_CODE (arg) == MEM_REF
3654 && TREE_OPERAND (arg, 0) == name
3655 && integer_zerop (TREE_OPERAND (arg, 1))
3656 && types_compatible_p (TREE_TYPE (arg),
3657 TREE_TYPE (TREE_TYPE (name)))
3658 && !TREE_THIS_VOLATILE (arg))
3659 uses_ok++;
3663 /* If the number of valid uses does not match the number of
3664 uses in this stmt there is an unhandled use. */
3665 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
3666 --uses_ok;
3668 if (uses_ok != 0)
3669 ret = true;
3671 if (ret)
3672 BREAK_FROM_IMM_USE_STMT (ui);
3675 return ret;
3678 /* Identify candidates for reduction for IPA-SRA based on their type and mark
3679 them in candidate_bitmap. Note that these do not necessarily include
3680 parameter which are unused and thus can be removed. Return true iff any
3681 such candidate has been found. */
3683 static bool
3684 find_param_candidates (void)
3686 tree parm;
3687 int count = 0;
3688 bool ret = false;
3689 const char *msg;
3691 for (parm = DECL_ARGUMENTS (current_function_decl);
3692 parm;
3693 parm = DECL_CHAIN (parm))
3695 tree type = TREE_TYPE (parm);
3696 tree_node **slot;
3698 count++;
3700 if (TREE_THIS_VOLATILE (parm)
3701 || TREE_ADDRESSABLE (parm)
3702 || (!is_gimple_reg_type (type) && is_va_list_type (type)))
3703 continue;
3705 if (is_unused_scalar_param (parm))
3707 ret = true;
3708 continue;
3711 if (POINTER_TYPE_P (type))
3713 type = TREE_TYPE (type);
3715 if (TREE_CODE (type) == FUNCTION_TYPE
3716 || TYPE_VOLATILE (type)
3717 || (TREE_CODE (type) == ARRAY_TYPE
3718 && TYPE_NONALIASED_COMPONENT (type))
3719 || !is_gimple_reg (parm)
3720 || is_va_list_type (type)
3721 || ptr_parm_has_direct_uses (parm))
3722 continue;
3724 else if (!AGGREGATE_TYPE_P (type))
3725 continue;
3727 if (!COMPLETE_TYPE_P (type)
3728 || !tree_fits_uhwi_p (TYPE_SIZE (type))
3729 || tree_to_uhwi (TYPE_SIZE (type)) == 0
3730 || (AGGREGATE_TYPE_P (type)
3731 && type_internals_preclude_sra_p (type, &msg)))
3732 continue;
3734 bitmap_set_bit (candidate_bitmap, DECL_UID (parm));
3735 slot = candidates.find_slot_with_hash (parm, DECL_UID (parm), INSERT);
3736 *slot = parm;
3738 ret = true;
3739 if (dump_file && (dump_flags & TDF_DETAILS))
3741 fprintf (dump_file, "Candidate (%d): ", DECL_UID (parm));
3742 print_generic_expr (dump_file, parm, 0);
3743 fprintf (dump_file, "\n");
3747 func_param_count = count;
3748 return ret;
3751 /* Callback of walk_aliased_vdefs, marks the access passed as DATA as
3752 maybe_modified. */
3754 static bool
3755 mark_maybe_modified (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef ATTRIBUTE_UNUSED,
3756 void *data)
3758 struct access *repr = (struct access *) data;
3760 repr->grp_maybe_modified = 1;
3761 return true;
3764 /* Analyze what representatives (in linked lists accessible from
3765 REPRESENTATIVES) can be modified by side effects of statements in the
3766 current function. */
3768 static void
3769 analyze_modified_params (vec<access_p> representatives)
3771 int i;
3773 for (i = 0; i < func_param_count; i++)
3775 struct access *repr;
3777 for (repr = representatives[i];
3778 repr;
3779 repr = repr->next_grp)
3781 struct access *access;
3782 bitmap visited;
3783 ao_ref ar;
3785 if (no_accesses_p (repr))
3786 continue;
3787 if (!POINTER_TYPE_P (TREE_TYPE (repr->base))
3788 || repr->grp_maybe_modified)
3789 continue;
3791 ao_ref_init (&ar, repr->expr);
3792 visited = BITMAP_ALLOC (NULL);
3793 for (access = repr; access; access = access->next_sibling)
3795 /* All accesses are read ones, otherwise grp_maybe_modified would
3796 be trivially set. */
3797 walk_aliased_vdefs (&ar, gimple_vuse (access->stmt),
3798 mark_maybe_modified, repr, &visited);
3799 if (repr->grp_maybe_modified)
3800 break;
3802 BITMAP_FREE (visited);
3807 /* Propagate distances in bb_dereferences in the opposite direction than the
3808 control flow edges, in each step storing the maximum of the current value
3809 and the minimum of all successors. These steps are repeated until the table
3810 stabilizes. Note that BBs which might terminate the functions (according to
3811 final_bbs bitmap) never updated in this way. */
3813 static void
3814 propagate_dereference_distances (void)
3816 basic_block bb;
3818 auto_vec<basic_block> queue (last_basic_block_for_fn (cfun));
3819 queue.quick_push (ENTRY_BLOCK_PTR_FOR_FN (cfun));
3820 FOR_EACH_BB_FN (bb, cfun)
3822 queue.quick_push (bb);
3823 bb->aux = bb;
3826 while (!queue.is_empty ())
3828 edge_iterator ei;
3829 edge e;
3830 bool change = false;
3831 int i;
3833 bb = queue.pop ();
3834 bb->aux = NULL;
3836 if (bitmap_bit_p (final_bbs, bb->index))
3837 continue;
3839 for (i = 0; i < func_param_count; i++)
3841 int idx = bb->index * func_param_count + i;
3842 bool first = true;
3843 HOST_WIDE_INT inh = 0;
3845 FOR_EACH_EDGE (e, ei, bb->succs)
3847 int succ_idx = e->dest->index * func_param_count + i;
3849 if (e->src == EXIT_BLOCK_PTR_FOR_FN (cfun))
3850 continue;
3852 if (first)
3854 first = false;
3855 inh = bb_dereferences [succ_idx];
3857 else if (bb_dereferences [succ_idx] < inh)
3858 inh = bb_dereferences [succ_idx];
3861 if (!first && bb_dereferences[idx] < inh)
3863 bb_dereferences[idx] = inh;
3864 change = true;
3868 if (change && !bitmap_bit_p (final_bbs, bb->index))
3869 FOR_EACH_EDGE (e, ei, bb->preds)
3871 if (e->src->aux)
3872 continue;
3874 e->src->aux = e->src;
3875 queue.quick_push (e->src);
3880 /* Dump a dereferences TABLE with heading STR to file F. */
3882 static void
3883 dump_dereferences_table (FILE *f, const char *str, HOST_WIDE_INT *table)
3885 basic_block bb;
3887 fprintf (dump_file, str);
3888 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun),
3889 EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb)
3891 fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index));
3892 if (bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
3894 int i;
3895 for (i = 0; i < func_param_count; i++)
3897 int idx = bb->index * func_param_count + i;
3898 fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", table[idx]);
3901 fprintf (f, "\n");
3903 fprintf (dump_file, "\n");
3906 /* Determine what (parts of) parameters passed by reference that are not
3907 assigned to are not certainly dereferenced in this function and thus the
3908 dereferencing cannot be safely moved to the caller without potentially
3909 introducing a segfault. Mark such REPRESENTATIVES as
3910 grp_not_necessarilly_dereferenced.
3912 The dereferenced maximum "distance," i.e. the offset + size of the accessed
3913 part is calculated rather than simple booleans are calculated for each
3914 pointer parameter to handle cases when only a fraction of the whole
3915 aggregate is allocated (see testsuite/gcc.c-torture/execute/ipa-sra-2.c for
3916 an example).
3918 The maximum dereference distances for each pointer parameter and BB are
3919 already stored in bb_dereference. This routine simply propagates these
3920 values upwards by propagate_dereference_distances and then compares the
3921 distances of individual parameters in the ENTRY BB to the equivalent
3922 distances of each representative of a (fraction of a) parameter. */
3924 static void
3925 analyze_caller_dereference_legality (vec<access_p> representatives)
3927 int i;
3929 if (dump_file && (dump_flags & TDF_DETAILS))
3930 dump_dereferences_table (dump_file,
3931 "Dereference table before propagation:\n",
3932 bb_dereferences);
3934 propagate_dereference_distances ();
3936 if (dump_file && (dump_flags & TDF_DETAILS))
3937 dump_dereferences_table (dump_file,
3938 "Dereference table after propagation:\n",
3939 bb_dereferences);
3941 for (i = 0; i < func_param_count; i++)
3943 struct access *repr = representatives[i];
3944 int idx = ENTRY_BLOCK_PTR_FOR_FN (cfun)->index * func_param_count + i;
3946 if (!repr || no_accesses_p (repr))
3947 continue;
3951 if ((repr->offset + repr->size) > bb_dereferences[idx])
3952 repr->grp_not_necessarilly_dereferenced = 1;
3953 repr = repr->next_grp;
3955 while (repr);
3959 /* Return the representative access for the parameter declaration PARM if it is
3960 a scalar passed by reference which is not written to and the pointer value
3961 is not used directly. Thus, if it is legal to dereference it in the caller
3962 and we can rule out modifications through aliases, such parameter should be
3963 turned into one passed by value. Return NULL otherwise. */
3965 static struct access *
3966 unmodified_by_ref_scalar_representative (tree parm)
3968 int i, access_count;
3969 struct access *repr;
3970 vec<access_p> *access_vec;
3972 access_vec = get_base_access_vector (parm);
3973 gcc_assert (access_vec);
3974 repr = (*access_vec)[0];
3975 if (repr->write)
3976 return NULL;
3977 repr->group_representative = repr;
3979 access_count = access_vec->length ();
3980 for (i = 1; i < access_count; i++)
3982 struct access *access = (*access_vec)[i];
3983 if (access->write)
3984 return NULL;
3985 access->group_representative = repr;
3986 access->next_sibling = repr->next_sibling;
3987 repr->next_sibling = access;
3990 repr->grp_read = 1;
3991 repr->grp_scalar_ptr = 1;
3992 return repr;
3995 /* Return true iff this ACCESS precludes IPA-SRA of the parameter it is
3996 associated with. REQ_ALIGN is the minimum required alignment. */
3998 static bool
3999 access_precludes_ipa_sra_p (struct access *access, unsigned int req_align)
4001 unsigned int exp_align;
4002 /* Avoid issues such as the second simple testcase in PR 42025. The problem
4003 is incompatible assign in a call statement (and possibly even in asm
4004 statements). This can be relaxed by using a new temporary but only for
4005 non-TREE_ADDRESSABLE types and is probably not worth the complexity. (In
4006 intraprocedural SRA we deal with this by keeping the old aggregate around,
4007 something we cannot do in IPA-SRA.) */
4008 if (access->write
4009 && (is_gimple_call (access->stmt)
4010 || gimple_code (access->stmt) == GIMPLE_ASM))
4011 return true;
4013 exp_align = get_object_alignment (access->expr);
4014 if (exp_align < req_align)
4015 return true;
4017 return false;
4021 /* Sort collected accesses for parameter PARM, identify representatives for
4022 each accessed region and link them together. Return NULL if there are
4023 different but overlapping accesses, return the special ptr value meaning
4024 there are no accesses for this parameter if that is the case and return the
4025 first representative otherwise. Set *RO_GRP if there is a group of accesses
4026 with only read (i.e. no write) accesses. */
4028 static struct access *
4029 splice_param_accesses (tree parm, bool *ro_grp)
4031 int i, j, access_count, group_count;
4032 int agg_size, total_size = 0;
4033 struct access *access, *res, **prev_acc_ptr = &res;
4034 vec<access_p> *access_vec;
4036 access_vec = get_base_access_vector (parm);
4037 if (!access_vec)
4038 return &no_accesses_representant;
4039 access_count = access_vec->length ();
4041 access_vec->qsort (compare_access_positions);
4043 i = 0;
4044 total_size = 0;
4045 group_count = 0;
4046 while (i < access_count)
4048 bool modification;
4049 tree a1_alias_type;
4050 access = (*access_vec)[i];
4051 modification = access->write;
4052 if (access_precludes_ipa_sra_p (access, TYPE_ALIGN (access->type)))
4053 return NULL;
4054 a1_alias_type = reference_alias_ptr_type (access->expr);
4056 /* Access is about to become group representative unless we find some
4057 nasty overlap which would preclude us from breaking this parameter
4058 apart. */
4060 j = i + 1;
4061 while (j < access_count)
4063 struct access *ac2 = (*access_vec)[j];
4064 if (ac2->offset != access->offset)
4066 /* All or nothing law for parameters. */
4067 if (access->offset + access->size > ac2->offset)
4068 return NULL;
4069 else
4070 break;
4072 else if (ac2->size != access->size)
4073 return NULL;
4075 if (access_precludes_ipa_sra_p (ac2, TYPE_ALIGN (access->type))
4076 || (ac2->type != access->type
4077 && (TREE_ADDRESSABLE (ac2->type)
4078 || TREE_ADDRESSABLE (access->type)))
4079 || (reference_alias_ptr_type (ac2->expr) != a1_alias_type))
4080 return NULL;
4082 modification |= ac2->write;
4083 ac2->group_representative = access;
4084 ac2->next_sibling = access->next_sibling;
4085 access->next_sibling = ac2;
4086 j++;
4089 group_count++;
4090 access->grp_maybe_modified = modification;
4091 if (!modification)
4092 *ro_grp = true;
4093 *prev_acc_ptr = access;
4094 prev_acc_ptr = &access->next_grp;
4095 total_size += access->size;
4096 i = j;
4099 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4100 agg_size = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))));
4101 else
4102 agg_size = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (parm)));
4103 if (total_size >= agg_size)
4104 return NULL;
4106 gcc_assert (group_count > 0);
4107 return res;
4110 /* Decide whether parameters with representative accesses given by REPR should
4111 be reduced into components. */
4113 static int
4114 decide_one_param_reduction (struct access *repr)
4116 int total_size, cur_parm_size, agg_size, new_param_count, parm_size_limit;
4117 bool by_ref;
4118 tree parm;
4120 parm = repr->base;
4121 cur_parm_size = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (parm)));
4122 gcc_assert (cur_parm_size > 0);
4124 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4126 by_ref = true;
4127 agg_size = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (TREE_TYPE (parm))));
4129 else
4131 by_ref = false;
4132 agg_size = cur_parm_size;
4135 if (dump_file)
4137 struct access *acc;
4138 fprintf (dump_file, "Evaluating PARAM group sizes for ");
4139 print_generic_expr (dump_file, parm, 0);
4140 fprintf (dump_file, " (UID: %u): \n", DECL_UID (parm));
4141 for (acc = repr; acc; acc = acc->next_grp)
4142 dump_access (dump_file, acc, true);
4145 total_size = 0;
4146 new_param_count = 0;
4148 for (; repr; repr = repr->next_grp)
4150 gcc_assert (parm == repr->base);
4152 /* Taking the address of a non-addressable field is verboten. */
4153 if (by_ref && repr->non_addressable)
4154 return 0;
4156 /* Do not decompose a non-BLKmode param in a way that would
4157 create BLKmode params. Especially for by-reference passing
4158 (thus, pointer-type param) this is hardly worthwhile. */
4159 if (DECL_MODE (parm) != BLKmode
4160 && TYPE_MODE (repr->type) == BLKmode)
4161 return 0;
4163 if (!by_ref || (!repr->grp_maybe_modified
4164 && !repr->grp_not_necessarilly_dereferenced))
4165 total_size += repr->size;
4166 else
4167 total_size += cur_parm_size;
4169 new_param_count++;
4172 gcc_assert (new_param_count > 0);
4174 if (optimize_function_for_size_p (cfun))
4175 parm_size_limit = cur_parm_size;
4176 else
4177 parm_size_limit = (PARAM_VALUE (PARAM_IPA_SRA_PTR_GROWTH_FACTOR)
4178 * cur_parm_size);
4180 if (total_size < agg_size
4181 && total_size <= parm_size_limit)
4183 if (dump_file)
4184 fprintf (dump_file, " ....will be split into %i components\n",
4185 new_param_count);
4186 return new_param_count;
4188 else
4189 return 0;
4192 /* The order of the following enums is important, we need to do extra work for
4193 UNUSED_PARAMS, BY_VAL_ACCESSES and UNMODIF_BY_REF_ACCESSES. */
4194 enum ipa_splicing_result { NO_GOOD_ACCESS, UNUSED_PARAMS, BY_VAL_ACCESSES,
4195 MODIF_BY_REF_ACCESSES, UNMODIF_BY_REF_ACCESSES };
4197 /* Identify representatives of all accesses to all candidate parameters for
4198 IPA-SRA. Return result based on what representatives have been found. */
4200 static enum ipa_splicing_result
4201 splice_all_param_accesses (vec<access_p> &representatives)
4203 enum ipa_splicing_result result = NO_GOOD_ACCESS;
4204 tree parm;
4205 struct access *repr;
4207 representatives.create (func_param_count);
4209 for (parm = DECL_ARGUMENTS (current_function_decl);
4210 parm;
4211 parm = DECL_CHAIN (parm))
4213 if (is_unused_scalar_param (parm))
4215 representatives.quick_push (&no_accesses_representant);
4216 if (result == NO_GOOD_ACCESS)
4217 result = UNUSED_PARAMS;
4219 else if (POINTER_TYPE_P (TREE_TYPE (parm))
4220 && is_gimple_reg_type (TREE_TYPE (TREE_TYPE (parm)))
4221 && bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
4223 repr = unmodified_by_ref_scalar_representative (parm);
4224 representatives.quick_push (repr);
4225 if (repr)
4226 result = UNMODIF_BY_REF_ACCESSES;
4228 else if (bitmap_bit_p (candidate_bitmap, DECL_UID (parm)))
4230 bool ro_grp = false;
4231 repr = splice_param_accesses (parm, &ro_grp);
4232 representatives.quick_push (repr);
4234 if (repr && !no_accesses_p (repr))
4236 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4238 if (ro_grp)
4239 result = UNMODIF_BY_REF_ACCESSES;
4240 else if (result < MODIF_BY_REF_ACCESSES)
4241 result = MODIF_BY_REF_ACCESSES;
4243 else if (result < BY_VAL_ACCESSES)
4244 result = BY_VAL_ACCESSES;
4246 else if (no_accesses_p (repr) && (result == NO_GOOD_ACCESS))
4247 result = UNUSED_PARAMS;
4249 else
4250 representatives.quick_push (NULL);
4253 if (result == NO_GOOD_ACCESS)
4255 representatives.release ();
4256 return NO_GOOD_ACCESS;
4259 return result;
4262 /* Return the index of BASE in PARMS. Abort if it is not found. */
4264 static inline int
4265 get_param_index (tree base, vec<tree> parms)
4267 int i, len;
4269 len = parms.length ();
4270 for (i = 0; i < len; i++)
4271 if (parms[i] == base)
4272 return i;
4273 gcc_unreachable ();
4276 /* Convert the decisions made at the representative level into compact
4277 parameter adjustments. REPRESENTATIVES are pointers to first
4278 representatives of each param accesses, ADJUSTMENTS_COUNT is the expected
4279 final number of adjustments. */
4281 static ipa_parm_adjustment_vec
4282 turn_representatives_into_adjustments (vec<access_p> representatives,
4283 int adjustments_count)
4285 vec<tree> parms;
4286 ipa_parm_adjustment_vec adjustments;
4287 tree parm;
4288 int i;
4290 gcc_assert (adjustments_count > 0);
4291 parms = ipa_get_vector_of_formal_parms (current_function_decl);
4292 adjustments.create (adjustments_count);
4293 parm = DECL_ARGUMENTS (current_function_decl);
4294 for (i = 0; i < func_param_count; i++, parm = DECL_CHAIN (parm))
4296 struct access *repr = representatives[i];
4298 if (!repr || no_accesses_p (repr))
4300 struct ipa_parm_adjustment adj;
4302 memset (&adj, 0, sizeof (adj));
4303 adj.base_index = get_param_index (parm, parms);
4304 adj.base = parm;
4305 if (!repr)
4306 adj.op = IPA_PARM_OP_COPY;
4307 else
4308 adj.op = IPA_PARM_OP_REMOVE;
4309 adj.arg_prefix = "ISRA";
4310 adjustments.quick_push (adj);
4312 else
4314 struct ipa_parm_adjustment adj;
4315 int index = get_param_index (parm, parms);
4317 for (; repr; repr = repr->next_grp)
4319 memset (&adj, 0, sizeof (adj));
4320 gcc_assert (repr->base == parm);
4321 adj.base_index = index;
4322 adj.base = repr->base;
4323 adj.type = repr->type;
4324 adj.alias_ptr_type = reference_alias_ptr_type (repr->expr);
4325 adj.offset = repr->offset;
4326 adj.by_ref = (POINTER_TYPE_P (TREE_TYPE (repr->base))
4327 && (repr->grp_maybe_modified
4328 || repr->grp_not_necessarilly_dereferenced));
4329 adj.arg_prefix = "ISRA";
4330 adjustments.quick_push (adj);
4334 parms.release ();
4335 return adjustments;
4338 /* Analyze the collected accesses and produce a plan what to do with the
4339 parameters in the form of adjustments, NULL meaning nothing. */
4341 static ipa_parm_adjustment_vec
4342 analyze_all_param_acesses (void)
4344 enum ipa_splicing_result repr_state;
4345 bool proceed = false;
4346 int i, adjustments_count = 0;
4347 vec<access_p> representatives;
4348 ipa_parm_adjustment_vec adjustments;
4350 repr_state = splice_all_param_accesses (representatives);
4351 if (repr_state == NO_GOOD_ACCESS)
4352 return ipa_parm_adjustment_vec ();
4354 /* If there are any parameters passed by reference which are not modified
4355 directly, we need to check whether they can be modified indirectly. */
4356 if (repr_state == UNMODIF_BY_REF_ACCESSES)
4358 analyze_caller_dereference_legality (representatives);
4359 analyze_modified_params (representatives);
4362 for (i = 0; i < func_param_count; i++)
4364 struct access *repr = representatives[i];
4366 if (repr && !no_accesses_p (repr))
4368 if (repr->grp_scalar_ptr)
4370 adjustments_count++;
4371 if (repr->grp_not_necessarilly_dereferenced
4372 || repr->grp_maybe_modified)
4373 representatives[i] = NULL;
4374 else
4376 proceed = true;
4377 sra_stats.scalar_by_ref_to_by_val++;
4380 else
4382 int new_components = decide_one_param_reduction (repr);
4384 if (new_components == 0)
4386 representatives[i] = NULL;
4387 adjustments_count++;
4389 else
4391 adjustments_count += new_components;
4392 sra_stats.aggregate_params_reduced++;
4393 sra_stats.param_reductions_created += new_components;
4394 proceed = true;
4398 else
4400 if (no_accesses_p (repr))
4402 proceed = true;
4403 sra_stats.deleted_unused_parameters++;
4405 adjustments_count++;
4409 if (!proceed && dump_file)
4410 fprintf (dump_file, "NOT proceeding to change params.\n");
4412 if (proceed)
4413 adjustments = turn_representatives_into_adjustments (representatives,
4414 adjustments_count);
4415 else
4416 adjustments = ipa_parm_adjustment_vec ();
4418 representatives.release ();
4419 return adjustments;
4422 /* If a parameter replacement identified by ADJ does not yet exist in the form
4423 of declaration, create it and record it, otherwise return the previously
4424 created one. */
4426 static tree
4427 get_replaced_param_substitute (struct ipa_parm_adjustment *adj)
4429 tree repl;
4430 if (!adj->new_ssa_base)
4432 char *pretty_name = make_fancy_name (adj->base);
4434 repl = create_tmp_reg (TREE_TYPE (adj->base), "ISR");
4435 DECL_NAME (repl) = get_identifier (pretty_name);
4436 obstack_free (&name_obstack, pretty_name);
4438 adj->new_ssa_base = repl;
4440 else
4441 repl = adj->new_ssa_base;
4442 return repl;
4445 /* Find the first adjustment for a particular parameter BASE in a vector of
4446 ADJUSTMENTS which is not a copy_param. Return NULL if there is no such
4447 adjustment. */
4449 static struct ipa_parm_adjustment *
4450 get_adjustment_for_base (ipa_parm_adjustment_vec adjustments, tree base)
4452 int i, len;
4454 len = adjustments.length ();
4455 for (i = 0; i < len; i++)
4457 struct ipa_parm_adjustment *adj;
4459 adj = &adjustments[i];
4460 if (adj->op != IPA_PARM_OP_COPY && adj->base == base)
4461 return adj;
4464 return NULL;
4467 /* If the statement STMT defines an SSA_NAME of a parameter which is to be
4468 removed because its value is not used, replace the SSA_NAME with a one
4469 relating to a created VAR_DECL together all of its uses and return true.
4470 ADJUSTMENTS is a pointer to an adjustments vector. */
4472 static bool
4473 replace_removed_params_ssa_names (gimple stmt,
4474 ipa_parm_adjustment_vec adjustments)
4476 struct ipa_parm_adjustment *adj;
4477 tree lhs, decl, repl, name;
4479 if (gimple_code (stmt) == GIMPLE_PHI)
4480 lhs = gimple_phi_result (stmt);
4481 else if (is_gimple_assign (stmt))
4482 lhs = gimple_assign_lhs (stmt);
4483 else if (is_gimple_call (stmt))
4484 lhs = gimple_call_lhs (stmt);
4485 else
4486 gcc_unreachable ();
4488 if (TREE_CODE (lhs) != SSA_NAME)
4489 return false;
4491 decl = SSA_NAME_VAR (lhs);
4492 if (decl == NULL_TREE
4493 || TREE_CODE (decl) != PARM_DECL)
4494 return false;
4496 adj = get_adjustment_for_base (adjustments, decl);
4497 if (!adj)
4498 return false;
4500 repl = get_replaced_param_substitute (adj);
4501 name = make_ssa_name (repl, stmt);
4503 if (dump_file)
4505 fprintf (dump_file, "replacing an SSA name of a removed param ");
4506 print_generic_expr (dump_file, lhs, 0);
4507 fprintf (dump_file, " with ");
4508 print_generic_expr (dump_file, name, 0);
4509 fprintf (dump_file, "\n");
4512 if (is_gimple_assign (stmt))
4513 gimple_assign_set_lhs (stmt, name);
4514 else if (is_gimple_call (stmt))
4515 gimple_call_set_lhs (stmt, name);
4516 else
4517 gimple_phi_set_result (stmt, name);
4519 replace_uses_by (lhs, name);
4520 release_ssa_name (lhs);
4521 return true;
4524 /* If the statement pointed to by STMT_PTR contains any expressions that need
4525 to replaced with a different one as noted by ADJUSTMENTS, do so. Handle any
4526 potential type incompatibilities (GSI is used to accommodate conversion
4527 statements and must point to the statement). Return true iff the statement
4528 was modified. */
4530 static bool
4531 sra_ipa_modify_assign (gimple *stmt_ptr, gimple_stmt_iterator *gsi,
4532 ipa_parm_adjustment_vec adjustments)
4534 gimple stmt = *stmt_ptr;
4535 tree *lhs_p, *rhs_p;
4536 bool any;
4538 if (!gimple_assign_single_p (stmt))
4539 return false;
4541 rhs_p = gimple_assign_rhs1_ptr (stmt);
4542 lhs_p = gimple_assign_lhs_ptr (stmt);
4544 any = ipa_modify_expr (rhs_p, false, adjustments);
4545 any |= ipa_modify_expr (lhs_p, false, adjustments);
4546 if (any)
4548 tree new_rhs = NULL_TREE;
4550 if (!useless_type_conversion_p (TREE_TYPE (*lhs_p), TREE_TYPE (*rhs_p)))
4552 if (TREE_CODE (*rhs_p) == CONSTRUCTOR)
4554 /* V_C_Es of constructors can cause trouble (PR 42714). */
4555 if (is_gimple_reg_type (TREE_TYPE (*lhs_p)))
4556 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
4557 else
4558 *rhs_p = build_constructor (TREE_TYPE (*lhs_p),
4559 NULL);
4561 else
4562 new_rhs = fold_build1_loc (gimple_location (stmt),
4563 VIEW_CONVERT_EXPR, TREE_TYPE (*lhs_p),
4564 *rhs_p);
4566 else if (REFERENCE_CLASS_P (*rhs_p)
4567 && is_gimple_reg_type (TREE_TYPE (*lhs_p))
4568 && !is_gimple_reg (*lhs_p))
4569 /* This can happen when an assignment in between two single field
4570 structures is turned into an assignment in between two pointers to
4571 scalars (PR 42237). */
4572 new_rhs = *rhs_p;
4574 if (new_rhs)
4576 tree tmp = force_gimple_operand_gsi (gsi, new_rhs, true, NULL_TREE,
4577 true, GSI_SAME_STMT);
4579 gimple_assign_set_rhs_from_tree (gsi, tmp);
4582 return true;
4585 return false;
4588 /* Traverse the function body and all modifications as described in
4589 ADJUSTMENTS. Return true iff the CFG has been changed. */
4591 bool
4592 ipa_sra_modify_function_body (ipa_parm_adjustment_vec adjustments)
4594 bool cfg_changed = false;
4595 basic_block bb;
4597 FOR_EACH_BB_FN (bb, cfun)
4599 gimple_stmt_iterator gsi;
4601 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4602 replace_removed_params_ssa_names (gsi_stmt (gsi), adjustments);
4604 gsi = gsi_start_bb (bb);
4605 while (!gsi_end_p (gsi))
4607 gimple stmt = gsi_stmt (gsi);
4608 bool modified = false;
4609 tree *t;
4610 unsigned i;
4612 switch (gimple_code (stmt))
4614 case GIMPLE_RETURN:
4615 t = gimple_return_retval_ptr (stmt);
4616 if (*t != NULL_TREE)
4617 modified |= ipa_modify_expr (t, true, adjustments);
4618 break;
4620 case GIMPLE_ASSIGN:
4621 modified |= sra_ipa_modify_assign (&stmt, &gsi, adjustments);
4622 modified |= replace_removed_params_ssa_names (stmt, adjustments);
4623 break;
4625 case GIMPLE_CALL:
4626 /* Operands must be processed before the lhs. */
4627 for (i = 0; i < gimple_call_num_args (stmt); i++)
4629 t = gimple_call_arg_ptr (stmt, i);
4630 modified |= ipa_modify_expr (t, true, adjustments);
4633 if (gimple_call_lhs (stmt))
4635 t = gimple_call_lhs_ptr (stmt);
4636 modified |= ipa_modify_expr (t, false, adjustments);
4637 modified |= replace_removed_params_ssa_names (stmt,
4638 adjustments);
4640 break;
4642 case GIMPLE_ASM:
4643 for (i = 0; i < gimple_asm_ninputs (stmt); i++)
4645 t = &TREE_VALUE (gimple_asm_input_op (stmt, i));
4646 modified |= ipa_modify_expr (t, true, adjustments);
4648 for (i = 0; i < gimple_asm_noutputs (stmt); i++)
4650 t = &TREE_VALUE (gimple_asm_output_op (stmt, i));
4651 modified |= ipa_modify_expr (t, false, adjustments);
4653 break;
4655 default:
4656 break;
4659 if (modified)
4661 update_stmt (stmt);
4662 if (maybe_clean_eh_stmt (stmt)
4663 && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
4664 cfg_changed = true;
4666 gsi_next (&gsi);
4670 return cfg_changed;
4673 /* Call gimple_debug_bind_reset_value on all debug statements describing
4674 gimple register parameters that are being removed or replaced. */
4676 static void
4677 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments)
4679 int i, len;
4680 gimple_stmt_iterator *gsip = NULL, gsi;
4682 if (MAY_HAVE_DEBUG_STMTS && single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)))
4684 gsi = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
4685 gsip = &gsi;
4687 len = adjustments.length ();
4688 for (i = 0; i < len; i++)
4690 struct ipa_parm_adjustment *adj;
4691 imm_use_iterator ui;
4692 gimple stmt, def_temp;
4693 tree name, vexpr, copy = NULL_TREE;
4694 use_operand_p use_p;
4696 adj = &adjustments[i];
4697 if (adj->op == IPA_PARM_OP_COPY || !is_gimple_reg (adj->base))
4698 continue;
4699 name = ssa_default_def (cfun, adj->base);
4700 vexpr = NULL;
4701 if (name)
4702 FOR_EACH_IMM_USE_STMT (stmt, ui, name)
4704 if (gimple_clobber_p (stmt))
4706 gimple_stmt_iterator cgsi = gsi_for_stmt (stmt);
4707 unlink_stmt_vdef (stmt);
4708 gsi_remove (&cgsi, true);
4709 release_defs (stmt);
4710 continue;
4712 /* All other users must have been removed by
4713 ipa_sra_modify_function_body. */
4714 gcc_assert (is_gimple_debug (stmt));
4715 if (vexpr == NULL && gsip != NULL)
4717 gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
4718 vexpr = make_node (DEBUG_EXPR_DECL);
4719 def_temp = gimple_build_debug_source_bind (vexpr, adj->base,
4720 NULL);
4721 DECL_ARTIFICIAL (vexpr) = 1;
4722 TREE_TYPE (vexpr) = TREE_TYPE (name);
4723 DECL_MODE (vexpr) = DECL_MODE (adj->base);
4724 gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
4726 if (vexpr)
4728 FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
4729 SET_USE (use_p, vexpr);
4731 else
4732 gimple_debug_bind_reset_value (stmt);
4733 update_stmt (stmt);
4735 /* Create a VAR_DECL for debug info purposes. */
4736 if (!DECL_IGNORED_P (adj->base))
4738 copy = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
4739 VAR_DECL, DECL_NAME (adj->base),
4740 TREE_TYPE (adj->base));
4741 if (DECL_PT_UID_SET_P (adj->base))
4742 SET_DECL_PT_UID (copy, DECL_PT_UID (adj->base));
4743 TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (adj->base);
4744 TREE_READONLY (copy) = TREE_READONLY (adj->base);
4745 TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (adj->base);
4746 DECL_GIMPLE_REG_P (copy) = DECL_GIMPLE_REG_P (adj->base);
4747 DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (adj->base);
4748 DECL_IGNORED_P (copy) = DECL_IGNORED_P (adj->base);
4749 DECL_ABSTRACT_ORIGIN (copy) = DECL_ORIGIN (adj->base);
4750 DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
4751 SET_DECL_RTL (copy, 0);
4752 TREE_USED (copy) = 1;
4753 DECL_CONTEXT (copy) = current_function_decl;
4754 add_local_decl (cfun, copy);
4755 DECL_CHAIN (copy) =
4756 BLOCK_VARS (DECL_INITIAL (current_function_decl));
4757 BLOCK_VARS (DECL_INITIAL (current_function_decl)) = copy;
4759 if (gsip != NULL && copy && target_for_debug_bind (adj->base))
4761 gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
4762 if (vexpr)
4763 def_temp = gimple_build_debug_bind (copy, vexpr, NULL);
4764 else
4765 def_temp = gimple_build_debug_source_bind (copy, adj->base,
4766 NULL);
4767 gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
4772 /* Return false if all callers have at least as many actual arguments as there
4773 are formal parameters in the current function and that their types
4774 match. */
4776 static bool
4777 some_callers_have_mismatched_arguments_p (struct cgraph_node *node,
4778 void *data ATTRIBUTE_UNUSED)
4780 struct cgraph_edge *cs;
4781 for (cs = node->callers; cs; cs = cs->next_caller)
4782 if (!callsite_arguments_match_p (cs->call_stmt))
4783 return true;
4785 return false;
4788 /* Convert all callers of NODE. */
4790 static bool
4791 convert_callers_for_node (struct cgraph_node *node,
4792 void *data)
4794 ipa_parm_adjustment_vec *adjustments = (ipa_parm_adjustment_vec *) data;
4795 bitmap recomputed_callers = BITMAP_ALLOC (NULL);
4796 struct cgraph_edge *cs;
4798 for (cs = node->callers; cs; cs = cs->next_caller)
4800 push_cfun (DECL_STRUCT_FUNCTION (cs->caller->decl));
4802 if (dump_file)
4803 fprintf (dump_file, "Adjusting call %s/%i -> %s/%i\n",
4804 xstrdup (cs->caller->name ()),
4805 cs->caller->order,
4806 xstrdup (cs->callee->name ()),
4807 cs->callee->order);
4809 ipa_modify_call_arguments (cs, cs->call_stmt, *adjustments);
4811 pop_cfun ();
4814 for (cs = node->callers; cs; cs = cs->next_caller)
4815 if (bitmap_set_bit (recomputed_callers, cs->caller->uid)
4816 && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (cs->caller->decl)))
4817 compute_inline_parameters (cs->caller, true);
4818 BITMAP_FREE (recomputed_callers);
4820 return true;
4823 /* Convert all callers of NODE to pass parameters as given in ADJUSTMENTS. */
4825 static void
4826 convert_callers (struct cgraph_node *node, tree old_decl,
4827 ipa_parm_adjustment_vec adjustments)
4829 basic_block this_block;
4831 cgraph_for_node_and_aliases (node, convert_callers_for_node,
4832 &adjustments, false);
4834 if (!encountered_recursive_call)
4835 return;
4837 FOR_EACH_BB_FN (this_block, cfun)
4839 gimple_stmt_iterator gsi;
4841 for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
4843 gimple stmt = gsi_stmt (gsi);
4844 tree call_fndecl;
4845 if (gimple_code (stmt) != GIMPLE_CALL)
4846 continue;
4847 call_fndecl = gimple_call_fndecl (stmt);
4848 if (call_fndecl == old_decl)
4850 if (dump_file)
4851 fprintf (dump_file, "Adjusting recursive call");
4852 gimple_call_set_fndecl (stmt, node->decl);
4853 ipa_modify_call_arguments (NULL, stmt, adjustments);
4858 return;
4861 /* Perform all the modification required in IPA-SRA for NODE to have parameters
4862 as given in ADJUSTMENTS. Return true iff the CFG has been changed. */
4864 static bool
4865 modify_function (struct cgraph_node *node, ipa_parm_adjustment_vec adjustments)
4867 struct cgraph_node *new_node;
4868 bool cfg_changed;
4869 vec<cgraph_edge_p> redirect_callers = collect_callers_of_node (node);
4871 rebuild_cgraph_edges ();
4872 free_dominance_info (CDI_DOMINATORS);
4873 pop_cfun ();
4875 new_node = cgraph_function_versioning (node, redirect_callers,
4876 NULL,
4877 NULL, false, NULL, NULL, "isra");
4878 redirect_callers.release ();
4880 push_cfun (DECL_STRUCT_FUNCTION (new_node->decl));
4881 ipa_modify_formal_parameters (current_function_decl, adjustments);
4882 cfg_changed = ipa_sra_modify_function_body (adjustments);
4883 sra_ipa_reset_debug_stmts (adjustments);
4884 convert_callers (new_node, node->decl, adjustments);
4885 cgraph_make_node_local (new_node);
4886 return cfg_changed;
4889 /* If NODE has a caller, return true. */
4891 static bool
4892 has_caller_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
4894 if (node->callers)
4895 return true;
4896 return false;
4899 /* Return false the function is apparently unsuitable for IPA-SRA based on it's
4900 attributes, return true otherwise. NODE is the cgraph node of the current
4901 function. */
4903 static bool
4904 ipa_sra_preliminary_function_checks (struct cgraph_node *node)
4906 if (!cgraph_node_can_be_local_p (node))
4908 if (dump_file)
4909 fprintf (dump_file, "Function not local to this compilation unit.\n");
4910 return false;
4913 if (!node->local.can_change_signature)
4915 if (dump_file)
4916 fprintf (dump_file, "Function can not change signature.\n");
4917 return false;
4920 if (!tree_versionable_function_p (node->decl))
4922 if (dump_file)
4923 fprintf (dump_file, "Function is not versionable.\n");
4924 return false;
4927 if (!opt_for_fn (node->decl, optimize)
4928 || !opt_for_fn (node->decl, flag_ipa_sra))
4930 if (dump_file)
4931 fprintf (dump_file, "Function not optimized.\n");
4932 return false;
4935 if (DECL_VIRTUAL_P (current_function_decl))
4937 if (dump_file)
4938 fprintf (dump_file, "Function is a virtual method.\n");
4939 return false;
4942 if ((DECL_COMDAT (node->decl) || DECL_EXTERNAL (node->decl))
4943 && inline_summary (node)->size >= MAX_INLINE_INSNS_AUTO)
4945 if (dump_file)
4946 fprintf (dump_file, "Function too big to be made truly local.\n");
4947 return false;
4950 if (!cgraph_for_node_and_aliases (node, has_caller_p, NULL, true))
4952 if (dump_file)
4953 fprintf (dump_file,
4954 "Function has no callers in this compilation unit.\n");
4955 return false;
4958 if (cfun->stdarg)
4960 if (dump_file)
4961 fprintf (dump_file, "Function uses stdarg. \n");
4962 return false;
4965 if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl)))
4966 return false;
4968 return true;
4971 /* Perform early interprocedural SRA. */
4973 static unsigned int
4974 ipa_early_sra (void)
4976 struct cgraph_node *node = cgraph_get_node (current_function_decl);
4977 ipa_parm_adjustment_vec adjustments;
4978 int ret = 0;
4980 if (!ipa_sra_preliminary_function_checks (node))
4981 return 0;
4983 sra_initialize ();
4984 sra_mode = SRA_MODE_EARLY_IPA;
4986 if (!find_param_candidates ())
4988 if (dump_file)
4989 fprintf (dump_file, "Function has no IPA-SRA candidates.\n");
4990 goto simple_out;
4993 if (cgraph_for_node_and_aliases (node,
4994 some_callers_have_mismatched_arguments_p,
4995 NULL, true))
4997 if (dump_file)
4998 fprintf (dump_file, "There are callers with insufficient number of "
4999 "arguments or arguments with type mismatches.\n");
5000 goto simple_out;
5003 bb_dereferences = XCNEWVEC (HOST_WIDE_INT,
5004 func_param_count
5005 * last_basic_block_for_fn (cfun));
5006 final_bbs = BITMAP_ALLOC (NULL);
5008 scan_function ();
5009 if (encountered_apply_args)
5011 if (dump_file)
5012 fprintf (dump_file, "Function calls __builtin_apply_args().\n");
5013 goto out;
5016 if (encountered_unchangable_recursive_call)
5018 if (dump_file)
5019 fprintf (dump_file, "Function calls itself with insufficient "
5020 "number of arguments.\n");
5021 goto out;
5024 adjustments = analyze_all_param_acesses ();
5025 if (!adjustments.exists ())
5026 goto out;
5027 if (dump_file)
5028 ipa_dump_param_adjustments (dump_file, adjustments, current_function_decl);
5030 if (modify_function (node, adjustments))
5031 ret = TODO_update_ssa | TODO_cleanup_cfg;
5032 else
5033 ret = TODO_update_ssa;
5034 adjustments.release ();
5036 statistics_counter_event (cfun, "Unused parameters deleted",
5037 sra_stats.deleted_unused_parameters);
5038 statistics_counter_event (cfun, "Scalar parameters converted to by-value",
5039 sra_stats.scalar_by_ref_to_by_val);
5040 statistics_counter_event (cfun, "Aggregate parameters broken up",
5041 sra_stats.aggregate_params_reduced);
5042 statistics_counter_event (cfun, "Aggregate parameter components created",
5043 sra_stats.param_reductions_created);
5045 out:
5046 BITMAP_FREE (final_bbs);
5047 free (bb_dereferences);
5048 simple_out:
5049 sra_deinitialize ();
5050 return ret;
5053 /* Return if early ipa sra shall be performed. */
5054 static bool
5055 ipa_early_sra_gate (void)
5057 return flag_ipa_sra && dbg_cnt (eipa_sra);
5060 namespace {
5062 const pass_data pass_data_early_ipa_sra =
5064 GIMPLE_PASS, /* type */
5065 "eipa_sra", /* name */
5066 OPTGROUP_NONE, /* optinfo_flags */
5067 true, /* has_gate */
5068 true, /* has_execute */
5069 TV_IPA_SRA, /* tv_id */
5070 0, /* properties_required */
5071 0, /* properties_provided */
5072 0, /* properties_destroyed */
5073 0, /* todo_flags_start */
5074 TODO_dump_symtab, /* todo_flags_finish */
5077 class pass_early_ipa_sra : public gimple_opt_pass
5079 public:
5080 pass_early_ipa_sra (gcc::context *ctxt)
5081 : gimple_opt_pass (pass_data_early_ipa_sra, ctxt)
5084 /* opt_pass methods: */
5085 bool gate () { return ipa_early_sra_gate (); }
5086 unsigned int execute () { return ipa_early_sra (); }
5088 }; // class pass_early_ipa_sra
5090 } // anon namespace
5092 gimple_opt_pass *
5093 make_pass_early_ipa_sra (gcc::context *ctxt)
5095 return new pass_early_ipa_sra (ctxt);