1 /* Scalar Replacement of Aggregates (SRA) converts some structure
2 references into scalar references, exposing them to the scalar
4 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
5 Free Software Foundation, Inc.
6 Contributed by Diego Novillo <dnovillo@redhat.com>
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify it
11 under the terms of the GNU General Public License as published by the
12 Free Software Foundation; either version 3, or (at your option) any
15 GCC is distributed in the hope that it will be useful, but WITHOUT
16 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
26 #include "coretypes.h"
31 /* These RTL headers are needed for basic-block.h. */
34 #include "hard-reg-set.h"
35 #include "basic-block.h"
36 #include "diagnostic.h"
37 #include "langhooks.h"
38 #include "tree-inline.h"
39 #include "tree-flow.h"
41 #include "tree-dump.h"
42 #include "tree-pass.h"
48 /* expr.h is needed for MOVE_RATIO. */
53 /* This object of this pass is to replace a non-addressable aggregate with a
54 set of independent variables. Most of the time, all of these variables
55 will be scalars. But a secondary objective is to break up larger
56 aggregates into smaller aggregates. In the process we may find that some
57 bits of the larger aggregate can be deleted as unreferenced.
59 This substitution is done globally. More localized substitutions would
60 be the purvey of a load-store motion pass.
62 The optimization proceeds in phases:
64 (1) Identify variables that have types that are candidates for
67 (2) Scan the function looking for the ways these variables are used.
68 In particular we're interested in the number of times a variable
69 (or member) is needed as a complete unit, and the number of times
70 a variable (or member) is copied.
72 (3) Based on the usage profile, instantiate substitution variables.
74 (4) Scan the function making replacements.
78 /* True if this is the "early" pass, before inlining. */
79 static bool early_sra
;
81 /* The set of aggregate variables that are candidates for scalarization. */
82 static bitmap sra_candidates
;
84 /* Set of scalarizable PARM_DECLs that need copy-in operations at the
85 beginning of the function. */
86 static bitmap needs_copy_in
;
88 /* Sets of bit pairs that cache type decomposition and instantiation. */
89 static bitmap sra_type_decomp_cache
;
90 static bitmap sra_type_inst_cache
;
92 /* One of these structures is created for each candidate aggregate and
93 each (accessed) member or group of members of such an aggregate. */
96 /* A tree of the elements. Used when we want to traverse everything. */
97 struct sra_elt
*parent
;
98 struct sra_elt
*groups
;
99 struct sra_elt
*children
;
100 struct sra_elt
*sibling
;
102 /* If this element is a root, then this is the VAR_DECL. If this is
103 a sub-element, this is some token used to identify the reference.
104 In the case of COMPONENT_REF, this is the FIELD_DECL. In the case
105 of an ARRAY_REF, this is the (constant) index. In the case of an
106 ARRAY_RANGE_REF, this is the (constant) RANGE_EXPR. In the case
107 of a complex number, this is a zero or one. */
110 /* The type of the element. */
113 /* A VAR_DECL, for any sub-element we've decided to replace. */
116 /* The number of times the element is referenced as a whole. I.e.
117 given "a.b.c", this would be incremented for C, but not for A or B. */
120 /* The number of times the element is copied to or from another
121 scalarizable element. */
122 unsigned int n_copies
;
124 /* True if TYPE is scalar. */
127 /* True if this element is a group of members of its parent. */
130 /* True if we saw something about this element that prevents scalarization,
131 such as non-constant indexing. */
132 bool cannot_scalarize
;
134 /* True if we've decided that structure-to-structure assignment
135 should happen via memcpy and not per-element. */
138 /* True if everything under this element has been marked TREE_NO_WARNING. */
141 /* A flag for use with/after random access traversals. */
144 /* True if there is BIT_FIELD_REF on the lhs with a vector. */
147 /* 1 if the element is a field that is part of a block, 2 if the field
148 is the block itself, 0 if it's neither. */
149 char in_bitfld_block
;
152 #define IS_ELEMENT_FOR_GROUP(ELEMENT) (TREE_CODE (ELEMENT) == RANGE_EXPR)
154 #define FOR_EACH_ACTUAL_CHILD(CHILD, ELT) \
155 for ((CHILD) = (ELT)->is_group \
156 ? next_child_for_group (NULL, (ELT)) \
159 (CHILD) = (ELT)->is_group \
160 ? next_child_for_group ((CHILD), (ELT)) \
163 /* Helper function for above macro. Return next child in group. */
164 static struct sra_elt
*
165 next_child_for_group (struct sra_elt
*child
, struct sra_elt
*group
)
167 gcc_assert (group
->is_group
);
169 /* Find the next child in the parent. */
171 child
= child
->sibling
;
173 child
= group
->parent
->children
;
175 /* Skip siblings that do not belong to the group. */
178 tree g_elt
= group
->element
;
179 if (TREE_CODE (g_elt
) == RANGE_EXPR
)
181 if (!tree_int_cst_lt (child
->element
, TREE_OPERAND (g_elt
, 0))
182 && !tree_int_cst_lt (TREE_OPERAND (g_elt
, 1), child
->element
))
188 child
= child
->sibling
;
194 /* Random access to the child of a parent is performed by hashing.
195 This prevents quadratic behavior, and allows SRA to function
196 reasonably on larger records. */
197 static htab_t sra_map
;
199 /* All structures are allocated out of the following obstack. */
200 static struct obstack sra_obstack
;
202 /* Debugging functions. */
203 static void dump_sra_elt_name (FILE *, struct sra_elt
*);
204 extern void debug_sra_elt_name (struct sra_elt
*);
206 /* Forward declarations. */
207 static tree
generate_element_ref (struct sra_elt
*);
208 static gimple_seq
sra_build_assignment (tree dst
, tree src
);
209 static void mark_all_v_defs_seq (gimple_seq
);
212 /* Return true if DECL is an SRA candidate. */
215 is_sra_candidate_decl (tree decl
)
217 return DECL_P (decl
) && bitmap_bit_p (sra_candidates
, DECL_UID (decl
));
220 /* Return true if TYPE is a scalar type. */
223 is_sra_scalar_type (tree type
)
225 enum tree_code code
= TREE_CODE (type
);
226 return (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== VECTOR_TYPE
227 || code
== FIXED_POINT_TYPE
228 || code
== ENUMERAL_TYPE
|| code
== BOOLEAN_TYPE
229 || code
== POINTER_TYPE
|| code
== OFFSET_TYPE
230 || code
== REFERENCE_TYPE
);
233 /* Return true if TYPE can be decomposed into a set of independent variables.
235 Note that this doesn't imply that all elements of TYPE can be
236 instantiated, just that if we decide to break up the type into
237 separate pieces that it can be done. */
240 sra_type_can_be_decomposed_p (tree type
)
242 unsigned int cache
= TYPE_UID (TYPE_MAIN_VARIANT (type
)) * 2;
245 /* Avoid searching the same type twice. */
246 if (bitmap_bit_p (sra_type_decomp_cache
, cache
+0))
248 if (bitmap_bit_p (sra_type_decomp_cache
, cache
+1))
251 /* The type must have a definite nonzero size. */
252 if (TYPE_SIZE (type
) == NULL
|| TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
253 || integer_zerop (TYPE_SIZE (type
)))
256 /* The type must be a non-union aggregate. */
257 switch (TREE_CODE (type
))
261 bool saw_one_field
= false;
263 for (t
= TYPE_FIELDS (type
); t
; t
= TREE_CHAIN (t
))
264 if (TREE_CODE (t
) == FIELD_DECL
)
266 /* Reject incorrectly represented bit fields. */
267 if (DECL_BIT_FIELD (t
)
268 && INTEGRAL_TYPE_P (TREE_TYPE (t
))
269 && (tree_low_cst (DECL_SIZE (t
), 1)
270 != TYPE_PRECISION (TREE_TYPE (t
))))
273 /* And volatile fields. */
274 if (TREE_THIS_VOLATILE (t
))
277 saw_one_field
= true;
280 /* Record types must have at least one field. */
287 /* Array types must have a fixed lower and upper bound. */
288 t
= TYPE_DOMAIN (type
);
291 if (TYPE_MIN_VALUE (t
) == NULL
|| !TREE_CONSTANT (TYPE_MIN_VALUE (t
)))
293 if (TYPE_MAX_VALUE (t
) == NULL
|| !TREE_CONSTANT (TYPE_MAX_VALUE (t
)))
304 bitmap_set_bit (sra_type_decomp_cache
, cache
+0);
308 bitmap_set_bit (sra_type_decomp_cache
, cache
+1);
312 /* Returns true if the TYPE is one of the available va_list types.
313 Otherwise it returns false.
314 Note, that for multiple calling conventions there can be more
315 than just one va_list type present. */
318 is_va_list_type (tree type
)
322 if (type
== NULL_TREE
)
324 h
= targetm
.canonical_va_list_type (type
);
327 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (h
))
332 /* Return true if DECL can be decomposed into a set of independent
333 (though not necessarily scalar) variables. */
336 decl_can_be_decomposed_p (tree var
)
338 /* Early out for scalars. */
339 if (is_sra_scalar_type (TREE_TYPE (var
)))
342 /* The variable must not be aliased. */
343 if (!is_gimple_non_addressable (var
))
345 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
347 fprintf (dump_file
, "Cannot scalarize variable ");
348 print_generic_expr (dump_file
, var
, dump_flags
);
349 fprintf (dump_file
, " because it must live in memory\n");
354 /* The variable must not be volatile. */
355 if (TREE_THIS_VOLATILE (var
))
357 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
359 fprintf (dump_file
, "Cannot scalarize variable ");
360 print_generic_expr (dump_file
, var
, dump_flags
);
361 fprintf (dump_file
, " because it is declared volatile\n");
366 /* We must be able to decompose the variable's type. */
367 if (!sra_type_can_be_decomposed_p (TREE_TYPE (var
)))
369 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
371 fprintf (dump_file
, "Cannot scalarize variable ");
372 print_generic_expr (dump_file
, var
, dump_flags
);
373 fprintf (dump_file
, " because its type cannot be decomposed\n");
378 /* HACK: if we decompose a va_list_type_node before inlining, then we'll
379 confuse tree-stdarg.c, and we won't be able to figure out which and
380 how many arguments are accessed. This really should be improved in
381 tree-stdarg.c, as the decomposition is truly a win. This could also
382 be fixed if the stdarg pass ran early, but this can't be done until
383 we've aliasing information early too. See PR 30791. */
384 if (early_sra
&& is_va_list_type (TREE_TYPE (var
)))
390 /* Return true if TYPE can be *completely* decomposed into scalars. */
393 type_can_instantiate_all_elements (tree type
)
395 if (is_sra_scalar_type (type
))
397 if (!sra_type_can_be_decomposed_p (type
))
400 switch (TREE_CODE (type
))
404 unsigned int cache
= TYPE_UID (TYPE_MAIN_VARIANT (type
)) * 2;
407 if (bitmap_bit_p (sra_type_inst_cache
, cache
+0))
409 if (bitmap_bit_p (sra_type_inst_cache
, cache
+1))
412 for (f
= TYPE_FIELDS (type
); f
; f
= TREE_CHAIN (f
))
413 if (TREE_CODE (f
) == FIELD_DECL
)
415 if (!type_can_instantiate_all_elements (TREE_TYPE (f
)))
417 bitmap_set_bit (sra_type_inst_cache
, cache
+1);
422 bitmap_set_bit (sra_type_inst_cache
, cache
+0);
427 return type_can_instantiate_all_elements (TREE_TYPE (type
));
437 /* Test whether ELT or some sub-element cannot be scalarized. */
440 can_completely_scalarize_p (struct sra_elt
*elt
)
444 if (elt
->cannot_scalarize
)
447 for (c
= elt
->children
; c
; c
= c
->sibling
)
448 if (!can_completely_scalarize_p (c
))
451 for (c
= elt
->groups
; c
; c
= c
->sibling
)
452 if (!can_completely_scalarize_p (c
))
459 /* A simplified tree hashing algorithm that only handles the types of
460 trees we expect to find in sra_elt->element. */
463 sra_hash_tree (tree t
)
467 switch (TREE_CODE (t
))
476 h
= TREE_INT_CST_LOW (t
) ^ TREE_INT_CST_HIGH (t
);
480 h
= iterative_hash_expr (TREE_OPERAND (t
, 0), 0);
481 h
= iterative_hash_expr (TREE_OPERAND (t
, 1), h
);
485 /* We can have types that are compatible, but have different member
486 lists, so we can't hash fields by ID. Use offsets instead. */
487 h
= iterative_hash_expr (DECL_FIELD_OFFSET (t
), 0);
488 h
= iterative_hash_expr (DECL_FIELD_BIT_OFFSET (t
), h
);
492 /* Don't take operand 0 into account, that's our parent. */
493 h
= iterative_hash_expr (TREE_OPERAND (t
, 1), 0);
494 h
= iterative_hash_expr (TREE_OPERAND (t
, 2), h
);
504 /* Hash function for type SRA_PAIR. */
507 sra_elt_hash (const void *x
)
509 const struct sra_elt
*const e
= (const struct sra_elt
*) x
;
510 const struct sra_elt
*p
;
513 h
= sra_hash_tree (e
->element
);
515 /* Take into account everything except bitfield blocks back up the
516 chain. Given that chain lengths are rarely very long, this
517 should be acceptable. If we truly identify this as a performance
518 problem, it should work to hash the pointer value
520 for (p
= e
->parent
; p
; p
= p
->parent
)
521 if (!p
->in_bitfld_block
)
522 h
= (h
* 65521) ^ sra_hash_tree (p
->element
);
527 /* Equality function for type SRA_PAIR. */
530 sra_elt_eq (const void *x
, const void *y
)
532 const struct sra_elt
*const a
= (const struct sra_elt
*) x
;
533 const struct sra_elt
*const b
= (const struct sra_elt
*) y
;
535 const struct sra_elt
*ap
= a
->parent
;
536 const struct sra_elt
*bp
= b
->parent
;
539 while (ap
->in_bitfld_block
)
542 while (bp
->in_bitfld_block
)
553 if (TREE_CODE (ae
) != TREE_CODE (be
))
556 switch (TREE_CODE (ae
))
561 /* These are all pointer unique. */
565 /* Integers are not pointer unique, so compare their values. */
566 return tree_int_cst_equal (ae
, be
);
570 tree_int_cst_equal (TREE_OPERAND (ae
, 0), TREE_OPERAND (be
, 0))
571 && tree_int_cst_equal (TREE_OPERAND (ae
, 1), TREE_OPERAND (be
, 1));
574 /* Fields are unique within a record, but not between
575 compatible records. */
576 if (DECL_FIELD_CONTEXT (ae
) == DECL_FIELD_CONTEXT (be
))
578 return fields_compatible_p (ae
, be
);
582 tree_int_cst_equal (TREE_OPERAND (ae
, 1), TREE_OPERAND (be
, 1))
583 && tree_int_cst_equal (TREE_OPERAND (ae
, 2), TREE_OPERAND (be
, 2));
590 /* Create or return the SRA_ELT structure for CHILD in PARENT. PARENT
591 may be null, in which case CHILD must be a DECL. */
593 static struct sra_elt
*
594 lookup_element (struct sra_elt
*parent
, tree child
, tree type
,
595 enum insert_option insert
)
597 struct sra_elt dummy
;
598 struct sra_elt
**slot
;
602 dummy
.parent
= parent
->is_group
? parent
->parent
: parent
;
605 dummy
.element
= child
;
607 slot
= (struct sra_elt
**) htab_find_slot (sra_map
, &dummy
, insert
);
608 if (!slot
&& insert
== NO_INSERT
)
612 if (!elt
&& insert
== INSERT
)
614 *slot
= elt
= XOBNEW (&sra_obstack
, struct sra_elt
);
615 memset (elt
, 0, sizeof (*elt
));
617 elt
->parent
= parent
;
618 elt
->element
= child
;
620 elt
->is_scalar
= is_sra_scalar_type (type
);
624 if (IS_ELEMENT_FOR_GROUP (elt
->element
))
626 elt
->is_group
= true;
627 elt
->sibling
= parent
->groups
;
628 parent
->groups
= elt
;
632 elt
->sibling
= parent
->children
;
633 parent
->children
= elt
;
637 /* If this is a parameter, then if we want to scalarize, we have
638 one copy from the true function parameter. Count it now. */
639 if (TREE_CODE (child
) == PARM_DECL
)
642 bitmap_set_bit (needs_copy_in
, DECL_UID (child
));
649 /* Create or return the SRA_ELT structure for EXPR if the expression
650 refers to a scalarizable variable. */
652 static struct sra_elt
*
653 maybe_lookup_element_for_expr (tree expr
)
658 switch (TREE_CODE (expr
))
663 if (is_sra_candidate_decl (expr
))
664 return lookup_element (NULL
, expr
, TREE_TYPE (expr
), INSERT
);
668 /* We can't scalarize variable array indices. */
669 if (in_array_bounds_p (expr
))
670 child
= TREE_OPERAND (expr
, 1);
675 case ARRAY_RANGE_REF
:
676 /* We can't scalarize variable array indices. */
677 if (range_in_array_bounds_p (expr
))
679 tree domain
= TYPE_DOMAIN (TREE_TYPE (expr
));
680 child
= build2 (RANGE_EXPR
, integer_type_node
,
681 TYPE_MIN_VALUE (domain
), TYPE_MAX_VALUE (domain
));
689 tree type
= TREE_TYPE (TREE_OPERAND (expr
, 0));
690 /* Don't look through unions. */
691 if (TREE_CODE (type
) != RECORD_TYPE
)
693 /* Neither through variable-sized records. */
694 if (TYPE_SIZE (type
) == NULL_TREE
695 || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
697 child
= TREE_OPERAND (expr
, 1);
702 child
= integer_zero_node
;
705 child
= integer_one_node
;
712 elt
= maybe_lookup_element_for_expr (TREE_OPERAND (expr
, 0));
714 return lookup_element (elt
, child
, TREE_TYPE (expr
), INSERT
);
719 /* Functions to walk just enough of the tree to see all scalarizable
720 references, and categorize them. */
722 /* A set of callbacks for phases 2 and 4. They'll be invoked for the
723 various kinds of references seen. In all cases, *GSI is an iterator
724 pointing to the statement being processed. */
727 /* Invoked when ELT is required as a unit. Note that ELT might refer to
728 a leaf node, in which case this is a simple scalar reference. *EXPR_P
729 points to the location of the expression. IS_OUTPUT is true if this
730 is a left-hand-side reference. USE_ALL is true if we saw something we
731 couldn't quite identify and had to force the use of the entire object. */
732 void (*use
) (struct sra_elt
*elt
, tree
*expr_p
,
733 gimple_stmt_iterator
*gsi
, bool is_output
, bool use_all
);
735 /* Invoked when we have a copy between two scalarizable references. */
736 void (*copy
) (struct sra_elt
*lhs_elt
, struct sra_elt
*rhs_elt
,
737 gimple_stmt_iterator
*gsi
);
739 /* Invoked when ELT is initialized from a constant. VALUE may be NULL,
740 in which case it should be treated as an empty CONSTRUCTOR. */
741 void (*init
) (struct sra_elt
*elt
, tree value
, gimple_stmt_iterator
*gsi
);
743 /* Invoked when we have a copy between one scalarizable reference ELT
744 and one non-scalarizable reference OTHER without side-effects.
745 IS_OUTPUT is true if ELT is on the left-hand side. */
746 void (*ldst
) (struct sra_elt
*elt
, tree other
,
747 gimple_stmt_iterator
*gsi
, bool is_output
);
749 /* True during phase 2, false during phase 4. */
750 /* ??? This is a hack. */
754 #ifdef ENABLE_CHECKING
755 /* Invoked via walk_tree, if *TP contains a candidate decl, return it. */
758 sra_find_candidate_decl (tree
*tp
, int *walk_subtrees
,
759 void *data ATTRIBUTE_UNUSED
)
762 enum tree_code code
= TREE_CODE (t
);
764 if (code
== VAR_DECL
|| code
== PARM_DECL
|| code
== RESULT_DECL
)
767 if (is_sra_candidate_decl (t
))
777 /* Walk most expressions looking for a scalarizable aggregate.
778 If we find one, invoke FNS->USE. */
781 sra_walk_expr (tree
*expr_p
, gimple_stmt_iterator
*gsi
, bool is_output
,
782 const struct sra_walk_fns
*fns
)
786 bool disable_scalarization
= false;
787 bool use_all_p
= false;
789 /* We're looking to collect a reference expression between EXPR and INNER,
790 such that INNER is a scalarizable decl and all other nodes through EXPR
791 are references that we can scalarize. If we come across something that
792 we can't scalarize, we reset EXPR. This has the effect of making it
793 appear that we're referring to the larger expression as a whole. */
796 switch (TREE_CODE (inner
))
801 /* If there is a scalarizable decl at the bottom, then process it. */
802 if (is_sra_candidate_decl (inner
))
804 struct sra_elt
*elt
= maybe_lookup_element_for_expr (expr
);
805 if (disable_scalarization
)
806 elt
->cannot_scalarize
= true;
808 fns
->use (elt
, expr_p
, gsi
, is_output
, use_all_p
);
813 /* Non-constant index means any member may be accessed. Prevent the
814 expression from being scalarized. If we were to treat this as a
815 reference to the whole array, we can wind up with a single dynamic
816 index reference inside a loop being overridden by several constant
817 index references during loop setup. It's possible that this could
818 be avoided by using dynamic usage counts based on BB trip counts
819 (based on loop analysis or profiling), but that hardly seems worth
821 /* ??? Hack. Figure out how to push this into the scan routines
822 without duplicating too much code. */
823 if (!in_array_bounds_p (inner
))
825 disable_scalarization
= true;
828 /* ??? Are we assured that non-constant bounds and stride will have
829 the same value everywhere? I don't think Fortran will... */
830 if (TREE_OPERAND (inner
, 2) || TREE_OPERAND (inner
, 3))
832 inner
= TREE_OPERAND (inner
, 0);
835 case ARRAY_RANGE_REF
:
836 if (!range_in_array_bounds_p (inner
))
838 disable_scalarization
= true;
841 /* ??? See above non-constant bounds and stride . */
842 if (TREE_OPERAND (inner
, 2) || TREE_OPERAND (inner
, 3))
844 inner
= TREE_OPERAND (inner
, 0);
849 tree type
= TREE_TYPE (TREE_OPERAND (inner
, 0));
850 /* Don't look through unions. */
851 if (TREE_CODE (type
) != RECORD_TYPE
)
853 /* Neither through variable-sized records. */
854 if (TYPE_SIZE (type
) == NULL_TREE
855 || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
857 inner
= TREE_OPERAND (inner
, 0);
863 inner
= TREE_OPERAND (inner
, 0);
867 /* A bit field reference to a specific vector is scalarized but for
868 ones for inputs need to be marked as used on the left hand size so
869 when we scalarize it, we can mark that variable as non renamable. */
871 && TREE_CODE (TREE_TYPE (TREE_OPERAND (inner
, 0))) == VECTOR_TYPE
)
874 = maybe_lookup_element_for_expr (TREE_OPERAND (inner
, 0));
876 elt
->is_vector_lhs
= true;
879 /* A bit field reference (access to *multiple* fields simultaneously)
880 is not currently scalarized. Consider this an access to the full
881 outer element, to which walk_tree will bring us next. */
885 /* Similarly, a nop explicitly wants to look at an object in a
886 type other than the one we've scalarized. */
889 case VIEW_CONVERT_EXPR
:
890 /* Likewise for a view conversion, but with an additional twist:
891 it can be on the LHS and, in this case, an access to the full
892 outer element would mean a killing def. So we need to punt
893 if we haven't already a full access to the current element,
894 because we cannot pretend to have a killing def if we only
895 have a partial access at some level. */
896 if (is_output
&& !use_all_p
&& inner
!= expr
)
897 disable_scalarization
= true;
901 /* This is a transparent wrapper. The entire inner expression really
906 expr_p
= &TREE_OPERAND (inner
, 0);
907 inner
= expr
= *expr_p
;
912 #ifdef ENABLE_CHECKING
913 /* Validate that we're not missing any references. */
914 gcc_assert (!walk_tree (&inner
, sra_find_candidate_decl
, NULL
, NULL
));
920 /* Walk the arguments of a GIMPLE_CALL looking for scalarizable aggregates.
921 If we find one, invoke FNS->USE. */
924 sra_walk_gimple_call (gimple stmt
, gimple_stmt_iterator
*gsi
,
925 const struct sra_walk_fns
*fns
)
928 int nargs
= gimple_call_num_args (stmt
);
930 for (i
= 0; i
< nargs
; i
++)
931 sra_walk_expr (gimple_call_arg_ptr (stmt
, i
), gsi
, false, fns
);
933 if (gimple_call_lhs (stmt
))
934 sra_walk_expr (gimple_call_lhs_ptr (stmt
), gsi
, true, fns
);
937 /* Walk the inputs and outputs of a GIMPLE_ASM looking for scalarizable
938 aggregates. If we find one, invoke FNS->USE. */
941 sra_walk_gimple_asm (gimple stmt
, gimple_stmt_iterator
*gsi
,
942 const struct sra_walk_fns
*fns
)
945 for (i
= 0; i
< gimple_asm_ninputs (stmt
); i
++)
946 sra_walk_expr (&TREE_VALUE (gimple_asm_input_op (stmt
, i
)), gsi
, false, fns
);
947 for (i
= 0; i
< gimple_asm_noutputs (stmt
); i
++)
948 sra_walk_expr (&TREE_VALUE (gimple_asm_output_op (stmt
, i
)), gsi
, true, fns
);
951 /* Walk a GIMPLE_ASSIGN and categorize the assignment appropriately. */
954 sra_walk_gimple_assign (gimple stmt
, gimple_stmt_iterator
*gsi
,
955 const struct sra_walk_fns
*fns
)
957 struct sra_elt
*lhs_elt
= NULL
, *rhs_elt
= NULL
;
960 /* If there is more than 1 element on the RHS, only walk the lhs. */
961 if (!gimple_assign_single_p (stmt
))
963 sra_walk_expr (gimple_assign_lhs_ptr (stmt
), gsi
, true, fns
);
967 lhs
= gimple_assign_lhs (stmt
);
968 rhs
= gimple_assign_rhs1 (stmt
);
969 lhs_elt
= maybe_lookup_element_for_expr (lhs
);
970 rhs_elt
= maybe_lookup_element_for_expr (rhs
);
972 /* If both sides are scalarizable, this is a COPY operation. */
973 if (lhs_elt
&& rhs_elt
)
975 fns
->copy (lhs_elt
, rhs_elt
, gsi
);
979 /* If the RHS is scalarizable, handle it. There are only two cases. */
982 if (!rhs_elt
->is_scalar
&& !TREE_SIDE_EFFECTS (lhs
))
983 fns
->ldst (rhs_elt
, lhs
, gsi
, false);
985 fns
->use (rhs_elt
, gimple_assign_rhs1_ptr (stmt
), gsi
, false, false);
988 /* If it isn't scalarizable, there may be scalarizable variables within, so
989 check for a call or else walk the RHS to see if we need to do any
990 copy-in operations. We need to do it before the LHS is scalarized so
991 that the statements get inserted in the proper place, before any
992 copy-out operations. */
994 sra_walk_expr (gimple_assign_rhs1_ptr (stmt
), gsi
, false, fns
);
996 /* Likewise, handle the LHS being scalarizable. We have cases similar
997 to those above, but also want to handle RHS being constant. */
1000 /* If this is an assignment from a constant, or constructor, then
1001 we have access to all of the elements individually. Invoke INIT. */
1002 if (TREE_CODE (rhs
) == COMPLEX_EXPR
1003 || TREE_CODE (rhs
) == COMPLEX_CST
1004 || TREE_CODE (rhs
) == CONSTRUCTOR
)
1005 fns
->init (lhs_elt
, rhs
, gsi
);
1007 /* If this is an assignment from read-only memory, treat this as if
1008 we'd been passed the constructor directly. Invoke INIT. */
1009 else if (TREE_CODE (rhs
) == VAR_DECL
1010 && TREE_STATIC (rhs
)
1011 && !DECL_EXTERNAL (rhs
)
1012 && TREE_READONLY (rhs
)
1013 && targetm
.binds_local_p (rhs
))
1014 fns
->init (lhs_elt
, DECL_INITIAL (rhs
), gsi
);
1016 /* If this is a copy from a non-scalarizable lvalue, invoke LDST.
1017 The lvalue requirement prevents us from trying to directly scalarize
1018 the result of a function call. Which would result in trying to call
1019 the function multiple times, and other evil things. */
1020 else if (!lhs_elt
->is_scalar
1021 && !TREE_SIDE_EFFECTS (rhs
) && is_gimple_addressable (rhs
))
1022 fns
->ldst (lhs_elt
, rhs
, gsi
, true);
1024 /* Otherwise we're being used in some context that requires the
1025 aggregate to be seen as a whole. Invoke USE. */
1027 fns
->use (lhs_elt
, gimple_assign_lhs_ptr (stmt
), gsi
, true, false);
1030 /* Similarly to above, LHS_ELT being null only means that the LHS as a
1031 whole is not a scalarizable reference. There may be occurrences of
1032 scalarizable variables within, which implies a USE. */
1034 sra_walk_expr (gimple_assign_lhs_ptr (stmt
), gsi
, true, fns
);
1037 /* Entry point to the walk functions. Search the entire function,
1038 invoking the callbacks in FNS on each of the references to
1039 scalarizable variables. */
1042 sra_walk_function (const struct sra_walk_fns
*fns
)
1045 gimple_stmt_iterator si
, ni
;
1047 /* ??? Phase 4 could derive some benefit to walking the function in
1048 dominator tree order. */
1051 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); si
= ni
)
1055 stmt
= gsi_stmt (si
);
1060 /* If the statement does not reference memory, then it doesn't
1061 make any structure references that we care about. */
1062 if (!gimple_references_memory_p (stmt
))
1065 switch (gimple_code (stmt
))
1068 /* If we have "return <retval>" then the return value is
1069 already exposed for our pleasure. Walk it as a USE to
1070 force all the components back in place for the return.
1072 if (gimple_return_retval (stmt
) == NULL_TREE
)
1075 sra_walk_expr (gimple_return_retval_ptr (stmt
), &si
, false,
1080 sra_walk_gimple_assign (stmt
, &si
, fns
);
1083 sra_walk_gimple_call (stmt
, &si
, fns
);
1086 sra_walk_gimple_asm (stmt
, &si
, fns
);
1095 /* Phase One: Scan all referenced variables in the program looking for
1096 structures that could be decomposed. */
1099 find_candidates_for_sra (void)
1101 bool any_set
= false;
1103 referenced_var_iterator rvi
;
1105 FOR_EACH_REFERENCED_VAR (var
, rvi
)
1107 if (decl_can_be_decomposed_p (var
))
1109 bitmap_set_bit (sra_candidates
, DECL_UID (var
));
1118 /* Phase Two: Scan all references to scalarizable variables. Count the
1119 number of times they are used or copied respectively. */
1121 /* Callbacks to fill in SRA_WALK_FNS. Everything but USE is
1122 considered a copy, because we can decompose the reference such that
1123 the sub-elements needn't be contiguous. */
1126 scan_use (struct sra_elt
*elt
, tree
*expr_p ATTRIBUTE_UNUSED
,
1127 gimple_stmt_iterator
*gsi ATTRIBUTE_UNUSED
,
1128 bool is_output ATTRIBUTE_UNUSED
, bool use_all ATTRIBUTE_UNUSED
)
1134 scan_copy (struct sra_elt
*lhs_elt
, struct sra_elt
*rhs_elt
,
1135 gimple_stmt_iterator
*gsi ATTRIBUTE_UNUSED
)
1137 lhs_elt
->n_copies
+= 1;
1138 rhs_elt
->n_copies
+= 1;
1142 scan_init (struct sra_elt
*lhs_elt
, tree rhs ATTRIBUTE_UNUSED
,
1143 gimple_stmt_iterator
*gsi ATTRIBUTE_UNUSED
)
1145 lhs_elt
->n_copies
+= 1;
1149 scan_ldst (struct sra_elt
*elt
, tree other ATTRIBUTE_UNUSED
,
1150 gimple_stmt_iterator
*gsi ATTRIBUTE_UNUSED
,
1151 bool is_output ATTRIBUTE_UNUSED
)
1156 /* Dump the values we collected during the scanning phase. */
1159 scan_dump (struct sra_elt
*elt
)
1163 dump_sra_elt_name (dump_file
, elt
);
1164 fprintf (dump_file
, ": n_uses=%u n_copies=%u\n", elt
->n_uses
, elt
->n_copies
);
1166 for (c
= elt
->children
; c
; c
= c
->sibling
)
1169 for (c
= elt
->groups
; c
; c
= c
->sibling
)
1173 /* Entry point to phase 2. Scan the entire function, building up
1174 scalarization data structures, recording copies and uses. */
1177 scan_function (void)
1179 static const struct sra_walk_fns fns
= {
1180 scan_use
, scan_copy
, scan_init
, scan_ldst
, true
1184 sra_walk_function (&fns
);
1186 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1190 fputs ("\nScan results:\n", dump_file
);
1191 EXECUTE_IF_SET_IN_BITMAP (sra_candidates
, 0, i
, bi
)
1193 tree var
= referenced_var (i
);
1194 struct sra_elt
*elt
= lookup_element (NULL
, var
, NULL
, NO_INSERT
);
1198 fputc ('\n', dump_file
);
1202 /* Phase Three: Make decisions about which variables to scalarize, if any.
1203 All elements to be scalarized have replacement variables made for them. */
1205 /* A subroutine of build_element_name. Recursively build the element
1206 name on the obstack. */
1209 build_element_name_1 (struct sra_elt
*elt
)
1216 build_element_name_1 (elt
->parent
);
1217 obstack_1grow (&sra_obstack
, '$');
1219 if (TREE_CODE (elt
->parent
->type
) == COMPLEX_TYPE
)
1221 if (elt
->element
== integer_zero_node
)
1222 obstack_grow (&sra_obstack
, "real", 4);
1224 obstack_grow (&sra_obstack
, "imag", 4);
1230 if (TREE_CODE (t
) == INTEGER_CST
)
1232 /* ??? Eh. Don't bother doing double-wide printing. */
1233 sprintf (buffer
, HOST_WIDE_INT_PRINT_DEC
, TREE_INT_CST_LOW (t
));
1234 obstack_grow (&sra_obstack
, buffer
, strlen (buffer
));
1236 else if (TREE_CODE (t
) == BIT_FIELD_REF
)
1238 sprintf (buffer
, "B" HOST_WIDE_INT_PRINT_DEC
,
1239 tree_low_cst (TREE_OPERAND (t
, 2), 1));
1240 obstack_grow (&sra_obstack
, buffer
, strlen (buffer
));
1241 sprintf (buffer
, "F" HOST_WIDE_INT_PRINT_DEC
,
1242 tree_low_cst (TREE_OPERAND (t
, 1), 1));
1243 obstack_grow (&sra_obstack
, buffer
, strlen (buffer
));
1247 tree name
= DECL_NAME (t
);
1249 obstack_grow (&sra_obstack
, IDENTIFIER_POINTER (name
),
1250 IDENTIFIER_LENGTH (name
));
1253 sprintf (buffer
, "D%u", DECL_UID (t
));
1254 obstack_grow (&sra_obstack
, buffer
, strlen (buffer
));
1259 /* Construct a pretty variable name for an element's replacement variable.
1260 The name is built on the obstack. */
1263 build_element_name (struct sra_elt
*elt
)
1265 build_element_name_1 (elt
);
1266 obstack_1grow (&sra_obstack
, '\0');
1267 return XOBFINISH (&sra_obstack
, char *);
1270 /* Instantiate an element as an independent variable. */
1273 instantiate_element (struct sra_elt
*elt
)
1275 struct sra_elt
*base_elt
;
1277 bool nowarn
= TREE_NO_WARNING (elt
->element
);
1279 for (base_elt
= elt
; base_elt
->parent
; base_elt
= base_elt
->parent
)
1281 nowarn
= TREE_NO_WARNING (base_elt
->parent
->element
);
1282 base
= base_elt
->element
;
1284 elt
->replacement
= var
= make_rename_temp (elt
->type
, "SR");
1286 if (DECL_P (elt
->element
)
1287 && !tree_int_cst_equal (DECL_SIZE (var
), DECL_SIZE (elt
->element
)))
1289 DECL_SIZE (var
) = DECL_SIZE (elt
->element
);
1290 DECL_SIZE_UNIT (var
) = DECL_SIZE_UNIT (elt
->element
);
1292 elt
->in_bitfld_block
= 1;
1293 elt
->replacement
= fold_build3 (BIT_FIELD_REF
, elt
->type
, var
,
1296 ? size_binop (MINUS_EXPR
,
1297 TYPE_SIZE (elt
->type
),
1302 /* For vectors, if used on the left hand side with BIT_FIELD_REF,
1303 they are not a gimple register. */
1304 if (TREE_CODE (TREE_TYPE (var
)) == VECTOR_TYPE
&& elt
->is_vector_lhs
)
1305 DECL_GIMPLE_REG_P (var
) = 0;
1307 DECL_SOURCE_LOCATION (var
) = DECL_SOURCE_LOCATION (base
);
1308 DECL_ARTIFICIAL (var
) = 1;
1310 if (TREE_THIS_VOLATILE (elt
->type
))
1312 TREE_THIS_VOLATILE (var
) = 1;
1313 TREE_SIDE_EFFECTS (var
) = 1;
1316 if (DECL_NAME (base
) && !DECL_IGNORED_P (base
))
1318 char *pretty_name
= build_element_name (elt
);
1319 DECL_NAME (var
) = get_identifier (pretty_name
);
1320 obstack_free (&sra_obstack
, pretty_name
);
1322 SET_DECL_DEBUG_EXPR (var
, generate_element_ref (elt
));
1323 DECL_DEBUG_EXPR_IS_FROM (var
) = 1;
1325 DECL_IGNORED_P (var
) = 0;
1326 TREE_NO_WARNING (var
) = nowarn
;
1330 DECL_IGNORED_P (var
) = 1;
1331 /* ??? We can't generate any warning that would be meaningful. */
1332 TREE_NO_WARNING (var
) = 1;
1335 /* Zero-initialize bit-field scalarization variables, to avoid
1336 triggering undefined behavior. */
1337 if (TREE_CODE (elt
->element
) == BIT_FIELD_REF
1338 || (var
!= elt
->replacement
1339 && TREE_CODE (elt
->replacement
) == BIT_FIELD_REF
))
1341 gimple_seq init
= sra_build_assignment (var
,
1342 fold_convert (TREE_TYPE (var
),
1345 insert_edge_copies_seq (init
, ENTRY_BLOCK_PTR
);
1346 mark_all_v_defs_seq (init
);
1351 fputs (" ", dump_file
);
1352 dump_sra_elt_name (dump_file
, elt
);
1353 fputs (" -> ", dump_file
);
1354 print_generic_expr (dump_file
, var
, dump_flags
);
1355 fputc ('\n', dump_file
);
1359 /* Make one pass across an element tree deciding whether or not it's
1360 profitable to instantiate individual leaf scalars.
1362 PARENT_USES and PARENT_COPIES are the sum of the N_USES and N_COPIES
1363 fields all the way up the tree. */
1366 decide_instantiation_1 (struct sra_elt
*elt
, unsigned int parent_uses
,
1367 unsigned int parent_copies
)
1369 if (dump_file
&& !elt
->parent
)
1371 fputs ("Initial instantiation for ", dump_file
);
1372 dump_sra_elt_name (dump_file
, elt
);
1373 fputc ('\n', dump_file
);
1376 if (elt
->cannot_scalarize
)
1381 /* The decision is simple: instantiate if we're used more frequently
1382 than the parent needs to be seen as a complete unit. */
1383 if (elt
->n_uses
+ elt
->n_copies
+ parent_copies
> parent_uses
)
1384 instantiate_element (elt
);
1388 struct sra_elt
*c
, *group
;
1389 unsigned int this_uses
= elt
->n_uses
+ parent_uses
;
1390 unsigned int this_copies
= elt
->n_copies
+ parent_copies
;
1392 /* Consider groups of sub-elements as weighing in favour of
1393 instantiation whatever their size. */
1394 for (group
= elt
->groups
; group
; group
= group
->sibling
)
1395 FOR_EACH_ACTUAL_CHILD (c
, group
)
1397 c
->n_uses
+= group
->n_uses
;
1398 c
->n_copies
+= group
->n_copies
;
1401 for (c
= elt
->children
; c
; c
= c
->sibling
)
1402 decide_instantiation_1 (c
, this_uses
, this_copies
);
1406 /* Compute the size and number of all instantiated elements below ELT.
1407 We will only care about this if the size of the complete structure
1408 fits in a HOST_WIDE_INT, so we don't have to worry about overflow. */
1411 sum_instantiated_sizes (struct sra_elt
*elt
, unsigned HOST_WIDE_INT
*sizep
)
1413 if (elt
->replacement
)
1415 *sizep
+= TREE_INT_CST_LOW (TYPE_SIZE_UNIT (elt
->type
));
1421 unsigned int count
= 0;
1423 for (c
= elt
->children
; c
; c
= c
->sibling
)
1424 count
+= sum_instantiated_sizes (c
, sizep
);
1430 /* Instantiate fields in ELT->TYPE that are not currently present as
1433 static void instantiate_missing_elements (struct sra_elt
*elt
);
1435 static struct sra_elt
*
1436 instantiate_missing_elements_1 (struct sra_elt
*elt
, tree child
, tree type
)
1438 struct sra_elt
*sub
= lookup_element (elt
, child
, type
, INSERT
);
1441 if (sub
->replacement
== NULL
)
1442 instantiate_element (sub
);
1445 instantiate_missing_elements (sub
);
1449 /* Obtain the canonical type for field F of ELEMENT. */
1452 canon_type_for_field (tree f
, tree element
)
1454 tree field_type
= TREE_TYPE (f
);
1456 /* canonicalize_component_ref() unwidens some bit-field types (not
1457 marked as DECL_BIT_FIELD in C++), so we must do the same, lest we
1458 may introduce type mismatches. */
1459 if (INTEGRAL_TYPE_P (field_type
)
1460 && DECL_MODE (f
) != TYPE_MODE (field_type
))
1461 field_type
= TREE_TYPE (get_unwidened (build3 (COMPONENT_REF
,
1470 /* Look for adjacent fields of ELT starting at F that we'd like to
1471 scalarize as a single variable. Return the last field of the
1475 try_instantiate_multiple_fields (struct sra_elt
*elt
, tree f
)
1478 unsigned HOST_WIDE_INT align
, bit
, size
, alchk
;
1479 enum machine_mode mode
;
1480 tree first
= f
, prev
;
1482 struct sra_elt
*block
;
1484 /* Point fields are typically best handled as standalone entities. */
1485 if (POINTER_TYPE_P (TREE_TYPE (f
)))
1488 if (!is_sra_scalar_type (TREE_TYPE (f
))
1489 || !host_integerp (DECL_FIELD_OFFSET (f
), 1)
1490 || !host_integerp (DECL_FIELD_BIT_OFFSET (f
), 1)
1491 || !host_integerp (DECL_SIZE (f
), 1)
1492 || lookup_element (elt
, f
, NULL
, NO_INSERT
))
1497 /* For complex and array objects, there are going to be integer
1498 literals as child elements. In this case, we can't just take the
1499 alignment and mode of the decl, so we instead rely on the element
1502 ??? We could try to infer additional alignment from the full
1503 object declaration and the location of the sub-elements we're
1505 for (count
= 0; !DECL_P (block
->element
); count
++)
1506 block
= block
->parent
;
1508 align
= DECL_ALIGN (block
->element
);
1509 alchk
= GET_MODE_BITSIZE (DECL_MODE (block
->element
));
1513 type
= TREE_TYPE (block
->element
);
1515 type
= TREE_TYPE (type
);
1517 align
= TYPE_ALIGN (type
);
1518 alchk
= GET_MODE_BITSIZE (TYPE_MODE (type
));
1524 /* Coalescing wider fields is probably pointless and
1526 if (align
> BITS_PER_WORD
)
1527 align
= BITS_PER_WORD
;
1529 bit
= tree_low_cst (DECL_FIELD_OFFSET (f
), 1) * BITS_PER_UNIT
1530 + tree_low_cst (DECL_FIELD_BIT_OFFSET (f
), 1);
1531 size
= tree_low_cst (DECL_SIZE (f
), 1);
1536 if ((bit
& alchk
) != ((bit
+ size
- 1) & alchk
))
1539 /* Find adjacent fields in the same alignment word. */
1541 for (prev
= f
, f
= TREE_CHAIN (f
);
1542 f
&& TREE_CODE (f
) == FIELD_DECL
1543 && is_sra_scalar_type (TREE_TYPE (f
))
1544 && host_integerp (DECL_FIELD_OFFSET (f
), 1)
1545 && host_integerp (DECL_FIELD_BIT_OFFSET (f
), 1)
1546 && host_integerp (DECL_SIZE (f
), 1)
1547 && !lookup_element (elt
, f
, NULL
, NO_INSERT
);
1548 prev
= f
, f
= TREE_CHAIN (f
))
1550 unsigned HOST_WIDE_INT nbit
, nsize
;
1552 nbit
= tree_low_cst (DECL_FIELD_OFFSET (f
), 1) * BITS_PER_UNIT
1553 + tree_low_cst (DECL_FIELD_BIT_OFFSET (f
), 1);
1554 nsize
= tree_low_cst (DECL_SIZE (f
), 1);
1556 if (bit
+ size
== nbit
)
1558 if ((bit
& alchk
) != ((nbit
+ nsize
- 1) & alchk
))
1560 /* If we're at an alignment boundary, don't bother
1561 growing alignment such that we can include this next
1564 || GET_MODE_BITSIZE (DECL_MODE (f
)) <= align
)
1567 align
= GET_MODE_BITSIZE (DECL_MODE (f
));
1571 if ((bit
& alchk
) != ((nbit
+ nsize
- 1) & alchk
))
1576 else if (nbit
+ nsize
== bit
)
1578 if ((nbit
& alchk
) != ((bit
+ size
- 1) & alchk
))
1581 || GET_MODE_BITSIZE (DECL_MODE (f
)) <= align
)
1584 align
= GET_MODE_BITSIZE (DECL_MODE (f
));
1588 if ((nbit
& alchk
) != ((bit
+ size
- 1) & alchk
))
1603 gcc_assert ((bit
& alchk
) == ((bit
+ size
- 1) & alchk
));
1605 /* Try to widen the bit range so as to cover padding bits as well. */
1607 if ((bit
& ~alchk
) || size
!= align
)
1609 unsigned HOST_WIDE_INT mbit
= bit
& alchk
;
1610 unsigned HOST_WIDE_INT msize
= align
;
1612 for (f
= TYPE_FIELDS (elt
->type
);
1613 f
; f
= TREE_CHAIN (f
))
1615 unsigned HOST_WIDE_INT fbit
, fsize
;
1617 /* Skip the fields from first to prev. */
1624 if (!(TREE_CODE (f
) == FIELD_DECL
1625 && host_integerp (DECL_FIELD_OFFSET (f
), 1)
1626 && host_integerp (DECL_FIELD_BIT_OFFSET (f
), 1)))
1629 fbit
= tree_low_cst (DECL_FIELD_OFFSET (f
), 1) * BITS_PER_UNIT
1630 + tree_low_cst (DECL_FIELD_BIT_OFFSET (f
), 1);
1632 /* If we're past the selected word, we're fine. */
1633 if ((bit
& alchk
) < (fbit
& alchk
))
1636 if (host_integerp (DECL_SIZE (f
), 1))
1637 fsize
= tree_low_cst (DECL_SIZE (f
), 1);
1639 /* Assume a variable-sized field takes up all space till
1640 the end of the word. ??? Endianness issues? */
1641 fsize
= align
- (fbit
& alchk
);
1643 if ((fbit
& alchk
) < (bit
& alchk
))
1645 /* A large field might start at a previous word and
1646 extend into the selected word. Exclude those
1647 bits. ??? Endianness issues? */
1648 HOST_WIDE_INT diff
= fbit
+ fsize
- mbit
;
1658 /* Non-overlapping, great. */
1659 if (fbit
+ fsize
<= mbit
1660 || mbit
+ msize
<= fbit
)
1665 unsigned HOST_WIDE_INT diff
= fbit
+ fsize
- mbit
;
1669 else if (fbit
> mbit
)
1670 msize
-= (mbit
+ msize
- fbit
);
1680 /* Now we know the bit range we're interested in. Find the smallest
1681 machine mode we can use to access it. */
1683 for (mode
= smallest_mode_for_size (size
, MODE_INT
);
1685 mode
= GET_MODE_WIDER_MODE (mode
))
1687 gcc_assert (mode
!= VOIDmode
);
1689 alchk
= GET_MODE_PRECISION (mode
) - 1;
1692 if ((bit
& alchk
) == ((bit
+ size
- 1) & alchk
))
1696 gcc_assert (~alchk
< align
);
1698 /* Create the field group as a single variable. */
1700 /* We used to create a type for the mode above, but size turns
1701 to be out not of mode-size. As we need a matching type
1702 to build a BIT_FIELD_REF, use a nonstandard integer type as
1704 type
= lang_hooks
.types
.type_for_size (size
, 1);
1705 if (!type
|| TYPE_PRECISION (type
) != size
)
1706 type
= build_nonstandard_integer_type (size
, 1);
1708 var
= build3 (BIT_FIELD_REF
, type
, NULL_TREE
,
1709 bitsize_int (size
), bitsize_int (bit
));
1711 block
= instantiate_missing_elements_1 (elt
, var
, type
);
1712 gcc_assert (block
&& block
->is_scalar
);
1714 var
= block
->replacement
;
1715 block
->in_bitfld_block
= 2;
1717 /* Add the member fields to the group, such that they access
1718 portions of the group variable. */
1720 for (f
= first
; f
!= TREE_CHAIN (prev
); f
= TREE_CHAIN (f
))
1722 tree field_type
= canon_type_for_field (f
, elt
->element
);
1723 struct sra_elt
*fld
= lookup_element (block
, f
, field_type
, INSERT
);
1725 gcc_assert (fld
&& fld
->is_scalar
&& !fld
->replacement
);
1727 fld
->replacement
= fold_build3 (BIT_FIELD_REF
, field_type
, var
,
1728 bitsize_int (TYPE_PRECISION (field_type
)),
1730 ((TREE_INT_CST_LOW (DECL_FIELD_OFFSET (f
))
1733 (DECL_FIELD_BIT_OFFSET (f
)))
1735 (TREE_OPERAND (block
->element
, 2))))
1737 fld
->in_bitfld_block
= 1;
1744 instantiate_missing_elements (struct sra_elt
*elt
)
1746 tree type
= elt
->type
;
1748 switch (TREE_CODE (type
))
1753 for (f
= TYPE_FIELDS (type
); f
; f
= TREE_CHAIN (f
))
1754 if (TREE_CODE (f
) == FIELD_DECL
)
1756 tree last
= try_instantiate_multiple_fields (elt
, f
);
1764 instantiate_missing_elements_1 (elt
, f
,
1765 canon_type_for_field
1773 tree i
, max
, subtype
;
1775 i
= TYPE_MIN_VALUE (TYPE_DOMAIN (type
));
1776 max
= TYPE_MAX_VALUE (TYPE_DOMAIN (type
));
1777 subtype
= TREE_TYPE (type
);
1781 instantiate_missing_elements_1 (elt
, i
, subtype
);
1782 if (tree_int_cst_equal (i
, max
))
1784 i
= int_const_binop (PLUS_EXPR
, i
, integer_one_node
, true);
1791 type
= TREE_TYPE (type
);
1792 instantiate_missing_elements_1 (elt
, integer_zero_node
, type
);
1793 instantiate_missing_elements_1 (elt
, integer_one_node
, type
);
1801 /* Return true if there is only one non aggregate field in the record, TYPE.
1802 Return false otherwise. */
1805 single_scalar_field_in_record_p (tree type
)
1809 if (TREE_CODE (type
) != RECORD_TYPE
)
1812 for (field
= TYPE_FIELDS (type
); field
; field
= TREE_CHAIN (field
))
1813 if (TREE_CODE (field
) == FIELD_DECL
)
1817 if (num_fields
== 2)
1820 if (AGGREGATE_TYPE_P (TREE_TYPE (field
)))
1827 /* Make one pass across an element tree deciding whether to perform block
1828 or element copies. If we decide on element copies, instantiate all
1829 elements. Return true if there are any instantiated sub-elements. */
1832 decide_block_copy (struct sra_elt
*elt
)
1837 /* We shouldn't be invoked on groups of sub-elements as they must
1838 behave like their parent as far as block copy is concerned. */
1839 gcc_assert (!elt
->is_group
);
1841 /* If scalarization is disabled, respect it. */
1842 if (elt
->cannot_scalarize
)
1844 elt
->use_block_copy
= 1;
1848 fputs ("Scalarization disabled for ", dump_file
);
1849 dump_sra_elt_name (dump_file
, elt
);
1850 fputc ('\n', dump_file
);
1853 /* Disable scalarization of sub-elements */
1854 for (c
= elt
->children
; c
; c
= c
->sibling
)
1856 c
->cannot_scalarize
= 1;
1857 decide_block_copy (c
);
1860 /* Groups behave like their parent. */
1861 for (c
= elt
->groups
; c
; c
= c
->sibling
)
1863 c
->cannot_scalarize
= 1;
1864 c
->use_block_copy
= 1;
1870 /* Don't decide if we've no uses and no groups. */
1871 if (elt
->n_uses
== 0 && elt
->n_copies
== 0 && elt
->groups
== NULL
)
1874 else if (!elt
->is_scalar
)
1876 tree size_tree
= TYPE_SIZE_UNIT (elt
->type
);
1877 bool use_block_copy
= true;
1879 /* Tradeoffs for COMPLEX types pretty much always make it better
1880 to go ahead and split the components. */
1881 if (TREE_CODE (elt
->type
) == COMPLEX_TYPE
)
1882 use_block_copy
= false;
1884 /* Don't bother trying to figure out the rest if the structure is
1885 so large we can't do easy arithmetic. This also forces block
1886 copies for variable sized structures. */
1887 else if (host_integerp (size_tree
, 1))
1889 unsigned HOST_WIDE_INT full_size
, inst_size
= 0;
1890 unsigned int max_size
, max_count
, inst_count
, full_count
;
1892 /* If the sra-max-structure-size parameter is 0, then the
1893 user has not overridden the parameter and we can choose a
1894 sensible default. */
1895 max_size
= SRA_MAX_STRUCTURE_SIZE
1896 ? SRA_MAX_STRUCTURE_SIZE
1897 : MOVE_RATIO (optimize_function_for_speed_p (cfun
)) * UNITS_PER_WORD
;
1898 max_count
= SRA_MAX_STRUCTURE_COUNT
1899 ? SRA_MAX_STRUCTURE_COUNT
1900 : MOVE_RATIO (optimize_function_for_speed_p (cfun
));
1902 full_size
= tree_low_cst (size_tree
, 1);
1903 full_count
= count_type_elements (elt
->type
, false);
1904 inst_count
= sum_instantiated_sizes (elt
, &inst_size
);
1906 /* If there is only one scalar field in the record, don't block copy. */
1907 if (single_scalar_field_in_record_p (elt
->type
))
1908 use_block_copy
= false;
1910 /* ??? What to do here. If there are two fields, and we've only
1911 instantiated one, then instantiating the other is clearly a win.
1912 If there are a large number of fields then the size of the copy
1913 is much more of a factor. */
1915 /* If the structure is small, and we've made copies, go ahead
1916 and instantiate, hoping that the copies will go away. */
1917 if (full_size
<= max_size
1918 && (full_count
- inst_count
) <= max_count
1919 && elt
->n_copies
> elt
->n_uses
)
1920 use_block_copy
= false;
1921 else if (inst_count
* 100 >= full_count
* SRA_FIELD_STRUCTURE_RATIO
1922 && inst_size
* 100 >= full_size
* SRA_FIELD_STRUCTURE_RATIO
)
1923 use_block_copy
= false;
1925 /* In order to avoid block copy, we have to be able to instantiate
1926 all elements of the type. See if this is possible. */
1928 && (!can_completely_scalarize_p (elt
)
1929 || !type_can_instantiate_all_elements (elt
->type
)))
1930 use_block_copy
= true;
1933 elt
->use_block_copy
= use_block_copy
;
1935 /* Groups behave like their parent. */
1936 for (c
= elt
->groups
; c
; c
= c
->sibling
)
1937 c
->use_block_copy
= use_block_copy
;
1941 fprintf (dump_file
, "Using %s for ",
1942 use_block_copy
? "block-copy" : "element-copy");
1943 dump_sra_elt_name (dump_file
, elt
);
1944 fputc ('\n', dump_file
);
1947 if (!use_block_copy
)
1949 instantiate_missing_elements (elt
);
1954 any_inst
= elt
->replacement
!= NULL
;
1956 for (c
= elt
->children
; c
; c
= c
->sibling
)
1957 any_inst
|= decide_block_copy (c
);
1962 /* Entry point to phase 3. Instantiate scalar replacement variables. */
1965 decide_instantiations (void)
1969 bitmap_head done_head
;
1972 /* We cannot clear bits from a bitmap we're iterating over,
1973 so save up all the bits to clear until the end. */
1974 bitmap_initialize (&done_head
, &bitmap_default_obstack
);
1975 cleared_any
= false;
1977 EXECUTE_IF_SET_IN_BITMAP (sra_candidates
, 0, i
, bi
)
1979 tree var
= referenced_var (i
);
1980 struct sra_elt
*elt
= lookup_element (NULL
, var
, NULL
, NO_INSERT
);
1983 decide_instantiation_1 (elt
, 0, 0);
1984 if (!decide_block_copy (elt
))
1989 bitmap_set_bit (&done_head
, i
);
1996 bitmap_and_compl_into (sra_candidates
, &done_head
);
1997 bitmap_and_compl_into (needs_copy_in
, &done_head
);
1999 bitmap_clear (&done_head
);
2001 mark_set_for_renaming (sra_candidates
);
2004 fputc ('\n', dump_file
);
2008 /* Phase Four: Update the function to match the replacements created. */
2010 /* Mark all the variables in virtual operands in all the statements in
2011 LIST for renaming. */
2014 mark_all_v_defs_seq (gimple_seq seq
)
2016 gimple_stmt_iterator gsi
;
2018 for (gsi
= gsi_start (seq
); !gsi_end_p (gsi
); gsi_next (&gsi
))
2019 update_stmt_if_modified (gsi_stmt (gsi
));
2022 /* Mark every replacement under ELT with TREE_NO_WARNING. */
2025 mark_no_warning (struct sra_elt
*elt
)
2027 if (!elt
->all_no_warning
)
2029 if (elt
->replacement
)
2030 TREE_NO_WARNING (elt
->replacement
) = 1;
2034 FOR_EACH_ACTUAL_CHILD (c
, elt
)
2035 mark_no_warning (c
);
2037 elt
->all_no_warning
= true;
2041 /* Build a single level component reference to ELT rooted at BASE. */
2044 generate_one_element_ref (struct sra_elt
*elt
, tree base
)
2046 switch (TREE_CODE (TREE_TYPE (base
)))
2050 tree field
= elt
->element
;
2052 /* We can't test elt->in_bitfld_block here because, when this is
2053 called from instantiate_element, we haven't set this field
2055 if (TREE_CODE (field
) == BIT_FIELD_REF
)
2057 tree ret
= unshare_expr (field
);
2058 TREE_OPERAND (ret
, 0) = base
;
2062 /* Watch out for compatible records with differing field lists. */
2063 if (DECL_FIELD_CONTEXT (field
) != TYPE_MAIN_VARIANT (TREE_TYPE (base
)))
2064 field
= find_compatible_field (TREE_TYPE (base
), field
);
2066 return build3 (COMPONENT_REF
, elt
->type
, base
, field
, NULL
);
2070 if (TREE_CODE (elt
->element
) == RANGE_EXPR
)
2071 return build4 (ARRAY_RANGE_REF
, elt
->type
, base
,
2072 TREE_OPERAND (elt
->element
, 0), NULL
, NULL
);
2074 return build4 (ARRAY_REF
, elt
->type
, base
, elt
->element
, NULL
, NULL
);
2077 if (elt
->element
== integer_zero_node
)
2078 return build1 (REALPART_EXPR
, elt
->type
, base
);
2080 return build1 (IMAGPART_EXPR
, elt
->type
, base
);
2087 /* Build a full component reference to ELT rooted at its native variable. */
2090 generate_element_ref (struct sra_elt
*elt
)
2093 return generate_one_element_ref (elt
, generate_element_ref (elt
->parent
));
2095 return elt
->element
;
2098 /* Return true if BF is a bit-field that we can handle like a scalar. */
2101 scalar_bitfield_p (tree bf
)
2103 return (TREE_CODE (bf
) == BIT_FIELD_REF
2104 && (is_gimple_reg (TREE_OPERAND (bf
, 0))
2105 || (TYPE_MODE (TREE_TYPE (TREE_OPERAND (bf
, 0))) != BLKmode
2106 && (!TREE_SIDE_EFFECTS (TREE_OPERAND (bf
, 0))
2107 || (GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE
2108 (TREE_OPERAND (bf
, 0))))
2109 <= BITS_PER_WORD
)))));
2112 /* Create an assignment statement from SRC to DST. */
2115 sra_build_assignment (tree dst
, tree src
)
2118 gimple_seq seq
= NULL
, seq2
= NULL
;
2119 /* Turning BIT_FIELD_REFs into bit operations enables other passes
2120 to do a much better job at optimizing the code.
2121 From dst = BIT_FIELD_REF <var, sz, off> we produce
2123 SR.1 = (scalar type) var;
2125 SR.3 = SR.2 & ((1 << sz) - 1);
2126 ... possible sign extension of SR.3 ...
2127 dst = (destination type) SR.3;
2129 if (scalar_bitfield_p (src
))
2131 tree var
, shift
, width
;
2133 bool unsignedp
= (INTEGRAL_TYPE_P (TREE_TYPE (src
))
2134 ? TYPE_UNSIGNED (TREE_TYPE (src
)) : true);
2135 struct gimplify_ctx gctx
;
2137 var
= TREE_OPERAND (src
, 0);
2138 width
= TREE_OPERAND (src
, 1);
2139 /* The offset needs to be adjusted to a right shift quantity
2140 depending on the endianness. */
2141 if (BYTES_BIG_ENDIAN
)
2143 tree tmp
= size_binop (PLUS_EXPR
, width
, TREE_OPERAND (src
, 2));
2144 shift
= size_binop (MINUS_EXPR
, TYPE_SIZE (TREE_TYPE (var
)), tmp
);
2147 shift
= TREE_OPERAND (src
, 2);
2149 /* In weird cases we have non-integral types for the source or
2151 ??? For unknown reasons we also want an unsigned scalar type. */
2152 stype
= TREE_TYPE (var
);
2153 if (!INTEGRAL_TYPE_P (stype
))
2154 stype
= lang_hooks
.types
.type_for_size (TREE_INT_CST_LOW
2155 (TYPE_SIZE (stype
)), 1);
2156 else if (!TYPE_UNSIGNED (stype
))
2157 stype
= unsigned_type_for (stype
);
2159 utype
= TREE_TYPE (dst
);
2160 if (!INTEGRAL_TYPE_P (utype
))
2161 utype
= lang_hooks
.types
.type_for_size (TREE_INT_CST_LOW
2162 (TYPE_SIZE (utype
)), 1);
2163 else if (!TYPE_UNSIGNED (utype
))
2164 utype
= unsigned_type_for (utype
);
2166 /* Convert the base var of the BIT_FIELD_REF to the scalar type
2167 we use for computation if we cannot use it directly. */
2168 if (INTEGRAL_TYPE_P (TREE_TYPE (var
)))
2169 var
= fold_convert (stype
, var
);
2171 var
= fold_build1 (VIEW_CONVERT_EXPR
, stype
, var
);
2173 if (!integer_zerop (shift
))
2174 var
= fold_build2 (RSHIFT_EXPR
, stype
, var
, shift
);
2176 /* If we need a masking operation, produce one. */
2177 if (TREE_INT_CST_LOW (width
) == TYPE_PRECISION (stype
))
2181 tree one
= build_int_cst_wide (stype
, 1, 0);
2182 tree mask
= int_const_binop (LSHIFT_EXPR
, one
, width
, 0);
2183 mask
= int_const_binop (MINUS_EXPR
, mask
, one
, 0);
2184 var
= fold_build2 (BIT_AND_EXPR
, stype
, var
, mask
);
2187 /* After shifting and masking, convert to the target type. */
2188 var
= fold_convert (utype
, var
);
2190 /* Perform sign extension, if required.
2191 ??? This should never be necessary. */
2194 tree signbit
= int_const_binop (LSHIFT_EXPR
,
2195 build_int_cst_wide (utype
, 1, 0),
2196 size_binop (MINUS_EXPR
, width
,
2197 bitsize_int (1)), 0);
2199 var
= fold_build2 (BIT_XOR_EXPR
, utype
, var
, signbit
);
2200 var
= fold_build2 (MINUS_EXPR
, utype
, var
, signbit
);
2203 /* fold_build3 (BIT_FIELD_REF, ...) sometimes returns a cast. */
2206 /* Finally, move and convert to the destination. */
2207 if (INTEGRAL_TYPE_P (TREE_TYPE (dst
)))
2208 var
= fold_convert (TREE_TYPE (dst
), var
);
2210 var
= fold_build1 (VIEW_CONVERT_EXPR
, TREE_TYPE (dst
), var
);
2212 push_gimplify_context (&gctx
);
2213 gctx
.allow_rhs_cond_expr
= true;
2215 gimplify_assign (dst
, var
, &seq
);
2217 if (gimple_referenced_vars (cfun
))
2218 for (var
= gctx
.temps
; var
; var
= TREE_CHAIN (var
))
2220 add_referenced_var (var
);
2221 mark_sym_for_renaming (var
);
2223 pop_gimplify_context (NULL
);
2228 /* fold_build3 (BIT_FIELD_REF, ...) sometimes returns a cast. */
2229 if (CONVERT_EXPR_P (dst
))
2232 src
= fold_convert (TREE_TYPE (dst
), src
);
2234 /* It was hoped that we could perform some type sanity checking
2235 here, but since front-ends can emit accesses of fields in types
2236 different from their nominal types and copy structures containing
2237 them as a whole, we'd have to handle such differences here.
2238 Since such accesses under different types require compatibility
2239 anyway, there's little point in making tests and/or adding
2240 conversions to ensure the types of src and dst are the same.
2241 So we just assume type differences at this point are ok.
2242 The only exception we make here are pointer types, which can be different
2243 in e.g. structurally equal, but non-identical RECORD_TYPEs. */
2244 else if (POINTER_TYPE_P (TREE_TYPE (dst
))
2245 && !useless_type_conversion_p (TREE_TYPE (dst
), TREE_TYPE (src
)))
2246 src
= fold_convert (TREE_TYPE (dst
), src
);
2248 /* ??? Only call the gimplifier if we need to. Otherwise we may
2249 end up substituting with DECL_VALUE_EXPR - see PR37380. */
2250 if (!handled_component_p (src
)
2251 && !SSA_VAR_P (src
))
2253 src
= force_gimple_operand (src
, &seq2
, false, NULL_TREE
);
2254 gimple_seq_add_seq (&seq
, seq2
);
2256 stmt
= gimple_build_assign (dst
, src
);
2257 gimple_seq_add_stmt (&seq
, stmt
);
2261 /* BIT_FIELD_REFs must not be shared. sra_build_elt_assignment()
2262 takes care of assignments, but we must create copies for uses. */
2263 #define REPLDUP(t) (TREE_CODE (t) != BIT_FIELD_REF ? (t) : unshare_expr (t))
2265 /* Emit an assignment from SRC to DST, but if DST is a scalarizable
2266 BIT_FIELD_REF, turn it into bit operations. */
2269 sra_build_bf_assignment (tree dst
, tree src
)
2271 tree var
, type
, utype
, tmp
, tmp2
, tmp3
;
2274 tree cst
, cst2
, mask
;
2275 tree minshift
, maxshift
;
2277 if (TREE_CODE (dst
) != BIT_FIELD_REF
)
2278 return sra_build_assignment (dst
, src
);
2280 var
= TREE_OPERAND (dst
, 0);
2282 if (!scalar_bitfield_p (dst
))
2283 return sra_build_assignment (REPLDUP (dst
), src
);
2287 cst
= fold_convert (bitsizetype
, TREE_OPERAND (dst
, 2));
2288 cst2
= size_binop (PLUS_EXPR
,
2289 fold_convert (bitsizetype
, TREE_OPERAND (dst
, 1)),
2292 if (BYTES_BIG_ENDIAN
)
2294 maxshift
= size_binop (MINUS_EXPR
, TYPE_SIZE (TREE_TYPE (var
)), cst
);
2295 minshift
= size_binop (MINUS_EXPR
, TYPE_SIZE (TREE_TYPE (var
)), cst2
);
2303 type
= TREE_TYPE (var
);
2304 if (!INTEGRAL_TYPE_P (type
))
2305 type
= lang_hooks
.types
.type_for_size
2306 (TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (var
))), 1);
2307 if (TYPE_UNSIGNED (type
))
2310 utype
= unsigned_type_for (type
);
2312 mask
= build_int_cst_wide (utype
, 1, 0);
2313 if (TREE_INT_CST_LOW (maxshift
) == TYPE_PRECISION (utype
))
2314 cst
= build_int_cst_wide (utype
, 0, 0);
2316 cst
= int_const_binop (LSHIFT_EXPR
, mask
, maxshift
, true);
2317 if (integer_zerop (minshift
))
2320 cst2
= int_const_binop (LSHIFT_EXPR
, mask
, minshift
, true);
2321 mask
= int_const_binop (MINUS_EXPR
, cst
, cst2
, true);
2322 mask
= fold_build1 (BIT_NOT_EXPR
, utype
, mask
);
2324 if (TYPE_MAIN_VARIANT (utype
) != TYPE_MAIN_VARIANT (TREE_TYPE (var
))
2325 && !integer_zerop (mask
))
2328 if (!is_gimple_variable (tmp
))
2329 tmp
= unshare_expr (var
);
2331 TREE_NO_WARNING (var
) = true;
2333 tmp2
= make_rename_temp (utype
, "SR");
2335 if (INTEGRAL_TYPE_P (TREE_TYPE (var
)))
2336 tmp
= fold_convert (utype
, tmp
);
2338 tmp
= fold_build1 (VIEW_CONVERT_EXPR
, utype
, tmp
);
2340 stmt
= gimple_build_assign (tmp2
, tmp
);
2341 gimple_seq_add_stmt (&seq
, stmt
);
2346 if (!integer_zerop (mask
))
2348 tmp
= make_rename_temp (utype
, "SR");
2349 stmt
= gimple_build_assign (tmp
, fold_build2 (BIT_AND_EXPR
, utype
,
2351 gimple_seq_add_stmt (&seq
, stmt
);
2356 if (is_gimple_reg (src
) && INTEGRAL_TYPE_P (TREE_TYPE (src
)))
2358 else if (INTEGRAL_TYPE_P (TREE_TYPE (src
)))
2361 tmp2
= make_rename_temp (TREE_TYPE (src
), "SR");
2362 tmp_seq
= sra_build_assignment (tmp2
, src
);
2363 gimple_seq_add_seq (&seq
, tmp_seq
);
2368 tmp2
= make_rename_temp
2369 (lang_hooks
.types
.type_for_size
2370 (TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (src
))),
2372 tmp_seq
= sra_build_assignment (tmp2
, fold_build1 (VIEW_CONVERT_EXPR
,
2373 TREE_TYPE (tmp2
), src
));
2374 gimple_seq_add_seq (&seq
, tmp_seq
);
2377 if (!TYPE_UNSIGNED (TREE_TYPE (tmp2
)))
2380 tree ut
= unsigned_type_for (TREE_TYPE (tmp2
));
2381 tmp3
= make_rename_temp (ut
, "SR");
2382 tmp2
= fold_convert (ut
, tmp2
);
2383 tmp_seq
= sra_build_assignment (tmp3
, tmp2
);
2384 gimple_seq_add_seq (&seq
, tmp_seq
);
2386 tmp2
= fold_build1 (BIT_NOT_EXPR
, utype
, mask
);
2387 tmp2
= int_const_binop (RSHIFT_EXPR
, tmp2
, minshift
, true);
2388 tmp2
= fold_convert (ut
, tmp2
);
2389 tmp2
= fold_build2 (BIT_AND_EXPR
, ut
, tmp3
, tmp2
);
2393 tmp3
= make_rename_temp (ut
, "SR");
2394 tmp_seq
= sra_build_assignment (tmp3
, tmp2
);
2395 gimple_seq_add_seq (&seq
, tmp_seq
);
2401 if (TYPE_MAIN_VARIANT (TREE_TYPE (tmp2
)) != TYPE_MAIN_VARIANT (utype
))
2404 tmp3
= make_rename_temp (utype
, "SR");
2405 tmp2
= fold_convert (utype
, tmp2
);
2406 tmp_seq
= sra_build_assignment (tmp3
, tmp2
);
2407 gimple_seq_add_seq (&seq
, tmp_seq
);
2411 if (!integer_zerop (minshift
))
2413 tmp3
= make_rename_temp (utype
, "SR");
2414 stmt
= gimple_build_assign (tmp3
, fold_build2 (LSHIFT_EXPR
, utype
,
2416 gimple_seq_add_stmt (&seq
, stmt
);
2420 if (utype
!= TREE_TYPE (var
))
2421 tmp3
= make_rename_temp (utype
, "SR");
2424 stmt
= gimple_build_assign (tmp3
, fold_build2 (BIT_IOR_EXPR
, utype
,
2426 gimple_seq_add_stmt (&seq
, stmt
);
2430 if (TREE_TYPE (var
) == type
)
2431 stmt
= gimple_build_assign (var
, fold_convert (type
, tmp3
));
2433 stmt
= gimple_build_assign (var
, fold_build1 (VIEW_CONVERT_EXPR
,
2434 TREE_TYPE (var
), tmp3
));
2435 gimple_seq_add_stmt (&seq
, stmt
);
2441 /* Expand an assignment of SRC to the scalarized representation of
2442 ELT. If it is a field group, try to widen the assignment to cover
2443 the full variable. */
2446 sra_build_elt_assignment (struct sra_elt
*elt
, tree src
)
2448 tree dst
= elt
->replacement
;
2449 tree var
, tmp
, cst
, cst2
;
2453 if (TREE_CODE (dst
) != BIT_FIELD_REF
2454 || !elt
->in_bitfld_block
)
2455 return sra_build_assignment (REPLDUP (dst
), src
);
2457 var
= TREE_OPERAND (dst
, 0);
2459 /* Try to widen the assignment to the entire variable.
2460 We need the source to be a BIT_FIELD_REF as well, such that, for
2461 BIT_FIELD_REF<d,sz,dp> = BIT_FIELD_REF<s,sz,sp>,
2462 by design, conditions are met such that we can turn it into
2463 d = BIT_FIELD_REF<s,dw,sp-dp>. */
2464 if (elt
->in_bitfld_block
== 2
2465 && TREE_CODE (src
) == BIT_FIELD_REF
)
2468 cst
= TYPE_SIZE (TREE_TYPE (var
));
2469 cst2
= size_binop (MINUS_EXPR
, TREE_OPERAND (src
, 2),
2470 TREE_OPERAND (dst
, 2));
2472 src
= TREE_OPERAND (src
, 0);
2474 /* Avoid full-width bit-fields. */
2475 if (integer_zerop (cst2
)
2476 && tree_int_cst_equal (cst
, TYPE_SIZE (TREE_TYPE (src
))))
2478 if (INTEGRAL_TYPE_P (TREE_TYPE (src
))
2479 && !TYPE_UNSIGNED (TREE_TYPE (src
)))
2480 src
= fold_convert (unsigned_type_for (TREE_TYPE (src
)), src
);
2482 /* If a single conversion won't do, we'll need a statement
2484 if (TYPE_MAIN_VARIANT (TREE_TYPE (var
))
2485 != TYPE_MAIN_VARIANT (TREE_TYPE (src
)))
2490 if (!INTEGRAL_TYPE_P (TREE_TYPE (src
)))
2491 src
= fold_build1 (VIEW_CONVERT_EXPR
,
2492 lang_hooks
.types
.type_for_size
2494 (TYPE_SIZE (TREE_TYPE (src
))),
2496 gcc_assert (TYPE_UNSIGNED (TREE_TYPE (src
)));
2498 tmp
= make_rename_temp (TREE_TYPE (src
), "SR");
2499 stmt
= gimple_build_assign (tmp
, src
);
2500 gimple_seq_add_stmt (&seq
, stmt
);
2502 tmp_seq
= sra_build_assignment (var
,
2503 fold_convert (TREE_TYPE (var
),
2505 gimple_seq_add_seq (&seq
, tmp_seq
);
2510 src
= fold_convert (TREE_TYPE (var
), src
);
2514 src
= fold_convert (TREE_TYPE (var
), tmp
);
2517 return sra_build_assignment (var
, src
);
2520 return sra_build_bf_assignment (dst
, src
);
2523 /* Generate a set of assignment statements in *LIST_P to copy all
2524 instantiated elements under ELT to or from the equivalent structure
2525 rooted at EXPR. COPY_OUT controls the direction of the copy, with
2526 true meaning to copy out of EXPR into ELT. */
2529 generate_copy_inout (struct sra_elt
*elt
, bool copy_out
, tree expr
,
2536 if (!copy_out
&& TREE_CODE (expr
) == SSA_NAME
2537 && TREE_CODE (TREE_TYPE (expr
)) == COMPLEX_TYPE
)
2541 c
= lookup_element (elt
, integer_zero_node
, NULL
, NO_INSERT
);
2543 c
= lookup_element (elt
, integer_one_node
, NULL
, NO_INSERT
);
2546 t
= build2 (COMPLEX_EXPR
, elt
->type
, r
, i
);
2547 tmp_seq
= sra_build_bf_assignment (expr
, t
);
2548 SSA_NAME_DEF_STMT (expr
) = gimple_seq_last_stmt (tmp_seq
);
2549 gimple_seq_add_seq (seq_p
, tmp_seq
);
2551 else if (elt
->replacement
)
2554 tmp_seq
= sra_build_elt_assignment (elt
, expr
);
2556 tmp_seq
= sra_build_bf_assignment (expr
, REPLDUP (elt
->replacement
));
2557 gimple_seq_add_seq (seq_p
, tmp_seq
);
2561 FOR_EACH_ACTUAL_CHILD (c
, elt
)
2563 t
= generate_one_element_ref (c
, unshare_expr (expr
));
2564 generate_copy_inout (c
, copy_out
, t
, seq_p
);
2569 /* Generate a set of assignment statements in *LIST_P to copy all instantiated
2570 elements under SRC to their counterparts under DST. There must be a 1-1
2571 correspondence of instantiated elements. */
2574 generate_element_copy (struct sra_elt
*dst
, struct sra_elt
*src
, gimple_seq
*seq_p
)
2576 struct sra_elt
*dc
, *sc
;
2578 FOR_EACH_ACTUAL_CHILD (dc
, dst
)
2580 sc
= lookup_element (src
, dc
->element
, NULL
, NO_INSERT
);
2581 if (!sc
&& dc
->in_bitfld_block
== 2)
2583 struct sra_elt
*dcs
;
2585 FOR_EACH_ACTUAL_CHILD (dcs
, dc
)
2587 sc
= lookup_element (src
, dcs
->element
, NULL
, NO_INSERT
);
2589 generate_element_copy (dcs
, sc
, seq_p
);
2595 /* If DST and SRC are structs with the same elements, but do not have
2596 the same TYPE_MAIN_VARIANT, then lookup of DST FIELD_DECL in SRC
2597 will fail. Try harder by finding the corresponding FIELD_DECL
2603 gcc_assert (useless_type_conversion_p (dst
->type
, src
->type
));
2604 gcc_assert (TREE_CODE (dc
->element
) == FIELD_DECL
);
2605 for (f
= TYPE_FIELDS (src
->type
); f
; f
= TREE_CHAIN (f
))
2606 if (simple_cst_equal (DECL_FIELD_OFFSET (f
),
2607 DECL_FIELD_OFFSET (dc
->element
)) > 0
2608 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (f
),
2609 DECL_FIELD_BIT_OFFSET (dc
->element
)) > 0
2610 && simple_cst_equal (DECL_SIZE (f
),
2611 DECL_SIZE (dc
->element
)) > 0
2612 && (useless_type_conversion_p (TREE_TYPE (dc
->element
),
2614 || (POINTER_TYPE_P (TREE_TYPE (dc
->element
))
2615 && POINTER_TYPE_P (TREE_TYPE (f
)))))
2617 gcc_assert (f
!= NULL_TREE
);
2618 sc
= lookup_element (src
, f
, NULL
, NO_INSERT
);
2621 generate_element_copy (dc
, sc
, seq_p
);
2624 if (dst
->replacement
)
2628 gcc_assert (src
->replacement
);
2630 tmp_seq
= sra_build_elt_assignment (dst
, REPLDUP (src
->replacement
));
2631 gimple_seq_add_seq (seq_p
, tmp_seq
);
2635 /* Generate a set of assignment statements in *LIST_P to zero all instantiated
2636 elements under ELT. In addition, do not assign to elements that have been
2637 marked VISITED but do reset the visited flag; this allows easy coordination
2638 with generate_element_init. */
2641 generate_element_zero (struct sra_elt
*elt
, gimple_seq
*seq_p
)
2647 elt
->visited
= false;
2651 if (!elt
->in_bitfld_block
)
2652 FOR_EACH_ACTUAL_CHILD (c
, elt
)
2653 generate_element_zero (c
, seq_p
);
2655 if (elt
->replacement
)
2660 gcc_assert (elt
->is_scalar
);
2661 t
= fold_convert (elt
->type
, integer_zero_node
);
2663 tmp_seq
= sra_build_elt_assignment (elt
, t
);
2664 gimple_seq_add_seq (seq_p
, tmp_seq
);
2668 /* Generate an assignment VAR = INIT, where INIT may need gimplification.
2669 Add the result to *LIST_P. */
2672 generate_one_element_init (struct sra_elt
*elt
, tree init
, gimple_seq
*seq_p
)
2674 gimple_seq tmp_seq
= sra_build_elt_assignment (elt
, init
);
2675 gimple_seq_add_seq (seq_p
, tmp_seq
);
2678 /* Generate a set of assignment statements in *LIST_P to set all instantiated
2679 elements under ELT with the contents of the initializer INIT. In addition,
2680 mark all assigned elements VISITED; this allows easy coordination with
2681 generate_element_zero. Return false if we found a case we couldn't
2685 generate_element_init_1 (struct sra_elt
*elt
, tree init
, gimple_seq
*seq_p
)
2688 enum tree_code init_code
;
2689 struct sra_elt
*sub
;
2691 unsigned HOST_WIDE_INT idx
;
2692 tree value
, purpose
;
2694 /* We can be passed DECL_INITIAL of a static variable. It might have a
2695 conversion, which we strip off here. */
2696 STRIP_USELESS_TYPE_CONVERSION (init
);
2697 init_code
= TREE_CODE (init
);
2701 if (elt
->replacement
)
2703 generate_one_element_init (elt
, init
, seq_p
);
2704 elt
->visited
= true;
2713 FOR_EACH_ACTUAL_CHILD (sub
, elt
)
2715 if (sub
->element
== integer_zero_node
)
2716 t
= (init_code
== COMPLEX_EXPR
2717 ? TREE_OPERAND (init
, 0) : TREE_REALPART (init
));
2719 t
= (init_code
== COMPLEX_EXPR
2720 ? TREE_OPERAND (init
, 1) : TREE_IMAGPART (init
));
2721 result
&= generate_element_init_1 (sub
, t
, seq_p
);
2726 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (init
), idx
, purpose
, value
)
2728 /* Array constructors are routinely created with NULL indices. */
2729 if (purpose
== NULL_TREE
)
2734 if (TREE_CODE (purpose
) == RANGE_EXPR
)
2736 tree lower
= TREE_OPERAND (purpose
, 0);
2737 tree upper
= TREE_OPERAND (purpose
, 1);
2741 sub
= lookup_element (elt
, lower
, NULL
, NO_INSERT
);
2743 result
&= generate_element_init_1 (sub
, value
, seq_p
);
2744 if (tree_int_cst_equal (lower
, upper
))
2746 lower
= int_const_binop (PLUS_EXPR
, lower
,
2747 integer_one_node
, true);
2752 sub
= lookup_element (elt
, purpose
, NULL
, NO_INSERT
);
2754 result
&= generate_element_init_1 (sub
, value
, seq_p
);
2760 elt
->visited
= true;
2767 /* A wrapper function for generate_element_init_1 that handles cleanup after
2771 generate_element_init (struct sra_elt
*elt
, tree init
, gimple_seq
*seq_p
)
2774 struct gimplify_ctx gctx
;
2776 push_gimplify_context (&gctx
);
2777 ret
= generate_element_init_1 (elt
, init
, seq_p
);
2778 pop_gimplify_context (NULL
);
2780 /* The replacement can expose previously unreferenced variables. */
2783 gimple_stmt_iterator i
;
2785 for (i
= gsi_start (*seq_p
); !gsi_end_p (i
); gsi_next (&i
))
2786 find_new_referenced_vars (gsi_stmt (i
));
2792 /* Insert a gimple_seq SEQ on all the outgoing edges out of BB. Note that
2793 if BB has more than one edge, STMT will be replicated for each edge.
2794 Also, abnormal edges will be ignored. */
2797 insert_edge_copies_seq (gimple_seq seq
, basic_block bb
)
2801 unsigned n_copies
= -1;
2803 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2804 if (!(e
->flags
& EDGE_ABNORMAL
))
2807 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2808 if (!(e
->flags
& EDGE_ABNORMAL
))
2809 gsi_insert_seq_on_edge (e
, n_copies
-- > 0 ? gimple_seq_copy (seq
) : seq
);
2812 /* Helper function to insert LIST before GSI, and set up line number info. */
2815 sra_insert_before (gimple_stmt_iterator
*gsi
, gimple_seq seq
)
2817 gimple stmt
= gsi_stmt (*gsi
);
2819 if (gimple_has_location (stmt
))
2820 annotate_all_with_location (seq
, gimple_location (stmt
));
2821 gsi_insert_seq_before (gsi
, seq
, GSI_SAME_STMT
);
2824 /* Similarly, but insert after GSI. Handles insertion onto edges as well. */
2827 sra_insert_after (gimple_stmt_iterator
*gsi
, gimple_seq seq
)
2829 gimple stmt
= gsi_stmt (*gsi
);
2831 if (gimple_has_location (stmt
))
2832 annotate_all_with_location (seq
, gimple_location (stmt
));
2834 if (stmt_ends_bb_p (stmt
))
2835 insert_edge_copies_seq (seq
, gsi_bb (*gsi
));
2837 gsi_insert_seq_after (gsi
, seq
, GSI_SAME_STMT
);
2840 /* Similarly, but replace the statement at GSI. */
2843 sra_replace (gimple_stmt_iterator
*gsi
, gimple_seq seq
)
2845 sra_insert_before (gsi
, seq
);
2846 unlink_stmt_vdef (gsi_stmt (*gsi
));
2847 gsi_remove (gsi
, false);
2848 if (gsi_end_p (*gsi
))
2849 *gsi
= gsi_last (gsi_seq (*gsi
));
2854 /* Data structure that bitfield_overlaps_p fills in with information
2855 about the element passed in and how much of it overlaps with the
2856 bit-range passed it to. */
2858 struct bitfield_overlap_info
2860 /* The bit-length of an element. */
2863 /* The bit-position of the element in its parent. */
2866 /* The number of bits of the element that overlap with the incoming
2870 /* The first bit of the element that overlaps with the incoming bit
2875 /* Return true if a BIT_FIELD_REF<(FLD->parent), BLEN, BPOS>
2876 expression (referenced as BF below) accesses any of the bits in FLD,
2877 false if it doesn't. If DATA is non-null, its field_len and
2878 field_pos are filled in such that BIT_FIELD_REF<(FLD->parent),
2879 field_len, field_pos> (referenced as BFLD below) represents the
2880 entire field FLD->element, and BIT_FIELD_REF<BFLD, overlap_len,
2881 overlap_pos> represents the portion of the entire field that
2882 overlaps with BF. */
2885 bitfield_overlaps_p (tree blen
, tree bpos
, struct sra_elt
*fld
,
2886 struct bitfield_overlap_info
*data
)
2891 if (TREE_CODE (fld
->element
) == FIELD_DECL
)
2893 flen
= fold_convert (bitsizetype
, DECL_SIZE (fld
->element
));
2894 fpos
= fold_convert (bitsizetype
, DECL_FIELD_OFFSET (fld
->element
));
2895 fpos
= size_binop (MULT_EXPR
, fpos
, bitsize_int (BITS_PER_UNIT
));
2896 fpos
= size_binop (PLUS_EXPR
, fpos
, DECL_FIELD_BIT_OFFSET (fld
->element
));
2898 else if (TREE_CODE (fld
->element
) == BIT_FIELD_REF
)
2900 flen
= fold_convert (bitsizetype
, TREE_OPERAND (fld
->element
, 1));
2901 fpos
= fold_convert (bitsizetype
, TREE_OPERAND (fld
->element
, 2));
2903 else if (TREE_CODE (fld
->element
) == INTEGER_CST
)
2905 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (fld
->parent
->element
));
2906 flen
= fold_convert (bitsizetype
, TYPE_SIZE (fld
->type
));
2907 fpos
= fold_convert (bitsizetype
, fld
->element
);
2908 if (domain_type
&& TYPE_MIN_VALUE (domain_type
))
2909 fpos
= size_binop (MINUS_EXPR
, fpos
,
2910 fold_convert (bitsizetype
,
2911 TYPE_MIN_VALUE (domain_type
)));
2912 fpos
= size_binop (MULT_EXPR
, flen
, fpos
);
2917 gcc_assert (host_integerp (blen
, 1)
2918 && host_integerp (bpos
, 1)
2919 && host_integerp (flen
, 1)
2920 && host_integerp (fpos
, 1));
2922 ret
= ((!tree_int_cst_lt (fpos
, bpos
)
2923 && tree_int_cst_lt (size_binop (MINUS_EXPR
, fpos
, bpos
),
2925 || (!tree_int_cst_lt (bpos
, fpos
)
2926 && tree_int_cst_lt (size_binop (MINUS_EXPR
, bpos
, fpos
),
2936 data
->field_len
= flen
;
2937 data
->field_pos
= fpos
;
2939 fend
= size_binop (PLUS_EXPR
, fpos
, flen
);
2940 bend
= size_binop (PLUS_EXPR
, bpos
, blen
);
2942 if (tree_int_cst_lt (bend
, fend
))
2943 data
->overlap_len
= size_binop (MINUS_EXPR
, bend
, fpos
);
2945 data
->overlap_len
= NULL
;
2947 if (tree_int_cst_lt (fpos
, bpos
))
2949 data
->overlap_pos
= size_binop (MINUS_EXPR
, bpos
, fpos
);
2950 data
->overlap_len
= size_binop (MINUS_EXPR
,
2957 data
->overlap_pos
= NULL
;
2963 /* Add to LISTP a sequence of statements that copies BLEN bits between
2964 VAR and the scalarized elements of ELT, starting a bit VPOS of VAR
2965 and at bit BPOS of ELT. The direction of the copy is given by
2969 sra_explode_bitfield_assignment (tree var
, tree vpos
, bool to_var
,
2970 gimple_seq
*seq_p
, tree blen
, tree bpos
,
2971 struct sra_elt
*elt
)
2973 struct sra_elt
*fld
;
2974 struct bitfield_overlap_info flp
;
2976 FOR_EACH_ACTUAL_CHILD (fld
, elt
)
2980 if (!bitfield_overlaps_p (blen
, bpos
, fld
, &flp
))
2983 flen
= flp
.overlap_len
? flp
.overlap_len
: flp
.field_len
;
2984 fpos
= flp
.overlap_pos
? flp
.overlap_pos
: bitsize_int (0);
2986 if (fld
->replacement
)
2988 tree infld
, invar
, type
;
2991 infld
= fld
->replacement
;
2993 type
= unsigned_type_for (TREE_TYPE (infld
));
2994 if (TYPE_PRECISION (type
) != TREE_INT_CST_LOW (flen
))
2995 type
= build_nonstandard_integer_type (TREE_INT_CST_LOW (flen
), 1);
2997 if (TREE_CODE (infld
) == BIT_FIELD_REF
)
2999 fpos
= size_binop (PLUS_EXPR
, fpos
, TREE_OPERAND (infld
, 2));
3000 infld
= TREE_OPERAND (infld
, 0);
3002 else if (BYTES_BIG_ENDIAN
&& DECL_P (fld
->element
)
3003 && !tree_int_cst_equal (TYPE_SIZE (TREE_TYPE (infld
)),
3004 DECL_SIZE (fld
->element
)))
3006 fpos
= size_binop (PLUS_EXPR
, fpos
,
3007 TYPE_SIZE (TREE_TYPE (infld
)));
3008 fpos
= size_binop (MINUS_EXPR
, fpos
,
3009 DECL_SIZE (fld
->element
));
3012 infld
= fold_build3 (BIT_FIELD_REF
, type
, infld
, flen
, fpos
);
3014 invar
= size_binop (MINUS_EXPR
, flp
.field_pos
, bpos
);
3015 if (flp
.overlap_pos
)
3016 invar
= size_binop (PLUS_EXPR
, invar
, flp
.overlap_pos
);
3017 invar
= size_binop (PLUS_EXPR
, invar
, vpos
);
3019 invar
= fold_build3 (BIT_FIELD_REF
, type
, var
, flen
, invar
);
3022 st
= sra_build_bf_assignment (invar
, infld
);
3024 st
= sra_build_bf_assignment (infld
, invar
);
3026 gimple_seq_add_seq (seq_p
, st
);
3030 tree sub
= size_binop (MINUS_EXPR
, flp
.field_pos
, bpos
);
3031 sub
= size_binop (PLUS_EXPR
, vpos
, sub
);
3032 if (flp
.overlap_pos
)
3033 sub
= size_binop (PLUS_EXPR
, sub
, flp
.overlap_pos
);
3035 sra_explode_bitfield_assignment (var
, sub
, to_var
, seq_p
,
3041 /* Add to LISTBEFOREP statements that copy scalarized members of ELT
3042 that overlap with BIT_FIELD_REF<(ELT->element), BLEN, BPOS> back
3043 into the full variable, and to LISTAFTERP, if non-NULL, statements
3044 that copy the (presumably modified) overlapping portions of the
3045 full variable back to the scalarized variables. */
3048 sra_sync_for_bitfield_assignment (gimple_seq
*seq_before_p
,
3049 gimple_seq
*seq_after_p
,
3050 tree blen
, tree bpos
,
3051 struct sra_elt
*elt
)
3053 struct sra_elt
*fld
;
3054 struct bitfield_overlap_info flp
;
3056 FOR_EACH_ACTUAL_CHILD (fld
, elt
)
3057 if (bitfield_overlaps_p (blen
, bpos
, fld
, &flp
))
3059 if (fld
->replacement
|| (!flp
.overlap_len
&& !flp
.overlap_pos
))
3061 generate_copy_inout (fld
, false, generate_element_ref (fld
),
3063 mark_no_warning (fld
);
3065 generate_copy_inout (fld
, true, generate_element_ref (fld
),
3070 tree flen
= flp
.overlap_len
? flp
.overlap_len
: flp
.field_len
;
3071 tree fpos
= flp
.overlap_pos
? flp
.overlap_pos
: bitsize_int (0);
3073 sra_sync_for_bitfield_assignment (seq_before_p
, seq_after_p
,
3079 /* Scalarize a USE. To recap, this is either a simple reference to ELT,
3080 if elt is scalar, or some occurrence of ELT that requires a complete
3081 aggregate. IS_OUTPUT is true if ELT is being modified. */
3084 scalarize_use (struct sra_elt
*elt
, tree
*expr_p
, gimple_stmt_iterator
*gsi
,
3085 bool is_output
, bool use_all
)
3087 gimple stmt
= gsi_stmt (*gsi
);
3090 if (elt
->replacement
)
3092 tree replacement
= elt
->replacement
;
3094 /* If we have a replacement, then updating the reference is as
3095 simple as modifying the existing statement in place. */
3097 && TREE_CODE (elt
->replacement
) == BIT_FIELD_REF
3098 && is_gimple_reg (TREE_OPERAND (elt
->replacement
, 0))
3099 && is_gimple_assign (stmt
)
3100 && gimple_assign_lhs_ptr (stmt
) == expr_p
)
3103 /* RHS must be a single operand. */
3104 gcc_assert (gimple_assign_single_p (stmt
));
3105 newseq
= sra_build_elt_assignment (elt
, gimple_assign_rhs1 (stmt
));
3106 sra_replace (gsi
, newseq
);
3110 && TREE_CODE (elt
->replacement
) == BIT_FIELD_REF
3111 && is_gimple_assign (stmt
)
3112 && gimple_assign_rhs1_ptr (stmt
) == expr_p
)
3114 tree tmp
= make_rename_temp
3115 (TREE_TYPE (gimple_assign_lhs (stmt
)), "SR");
3116 gimple_seq newseq
= sra_build_assignment (tmp
, REPLDUP (elt
->replacement
));
3118 sra_insert_before (gsi
, newseq
);
3122 update_stmt_if_modified (stmt
);
3123 *expr_p
= REPLDUP (replacement
);
3126 else if (use_all
&& is_output
3127 && is_gimple_assign (stmt
)
3128 && TREE_CODE (bfexpr
3129 = gimple_assign_lhs (stmt
)) == BIT_FIELD_REF
3130 && &TREE_OPERAND (bfexpr
, 0) == expr_p
3131 && INTEGRAL_TYPE_P (TREE_TYPE (bfexpr
))
3132 && TREE_CODE (TREE_TYPE (*expr_p
)) == RECORD_TYPE
)
3134 gimple_seq seq_before
= NULL
;
3135 gimple_seq seq_after
= NULL
;
3136 tree blen
= fold_convert (bitsizetype
, TREE_OPERAND (bfexpr
, 1));
3137 tree bpos
= fold_convert (bitsizetype
, TREE_OPERAND (bfexpr
, 2));
3138 bool update
= false;
3140 if (!elt
->use_block_copy
)
3142 tree type
= TREE_TYPE (bfexpr
);
3143 tree var
= make_rename_temp (type
, "SR"), tmp
, vpos
;
3146 gimple_assign_set_lhs (stmt
, var
);
3149 if (!TYPE_UNSIGNED (type
))
3151 type
= unsigned_type_for (type
);
3152 tmp
= make_rename_temp (type
, "SR");
3153 st
= gimple_build_assign (tmp
, fold_convert (type
, var
));
3154 gimple_seq_add_stmt (&seq_after
, st
);
3158 /* If VAR is wider than BLEN bits, it is padded at the
3159 most-significant end. We want to set VPOS such that
3160 <BIT_FIELD_REF VAR BLEN VPOS> would refer to the
3161 least-significant BLEN bits of VAR. */
3162 if (BYTES_BIG_ENDIAN
)
3163 vpos
= size_binop (MINUS_EXPR
, TYPE_SIZE (type
), blen
);
3165 vpos
= bitsize_int (0);
3166 sra_explode_bitfield_assignment
3167 (var
, vpos
, false, &seq_after
, blen
, bpos
, elt
);
3170 sra_sync_for_bitfield_assignment
3171 (&seq_before
, &seq_after
, blen
, bpos
, elt
);
3175 mark_all_v_defs_seq (seq_before
);
3176 sra_insert_before (gsi
, seq_before
);
3180 mark_all_v_defs_seq (seq_after
);
3181 sra_insert_after (gsi
, seq_after
);
3187 else if (use_all
&& !is_output
3188 && is_gimple_assign (stmt
)
3189 && TREE_CODE (bfexpr
3190 = gimple_assign_rhs1 (stmt
)) == BIT_FIELD_REF
3191 && &TREE_OPERAND (gimple_assign_rhs1 (stmt
), 0) == expr_p
3192 && INTEGRAL_TYPE_P (TREE_TYPE (bfexpr
))
3193 && TREE_CODE (TREE_TYPE (*expr_p
)) == RECORD_TYPE
)
3195 gimple_seq seq
= NULL
;
3196 tree blen
= fold_convert (bitsizetype
, TREE_OPERAND (bfexpr
, 1));
3197 tree bpos
= fold_convert (bitsizetype
, TREE_OPERAND (bfexpr
, 2));
3198 bool update
= false;
3200 if (!elt
->use_block_copy
)
3202 tree type
= TREE_TYPE (bfexpr
);
3203 tree var
= make_rename_temp (type
, "SR"), tmp
, vpos
;
3206 gimple_assign_set_rhs1 (stmt
, var
);
3209 if (!TYPE_UNSIGNED (type
))
3211 type
= unsigned_type_for (type
);
3212 tmp
= make_rename_temp (type
, "SR");
3213 st
= gimple_build_assign (var
,
3214 fold_convert (TREE_TYPE (var
), tmp
));
3218 gimple_seq_add_stmt (&seq
,
3220 (var
, build_int_cst_wide (type
, 0, 0)));
3222 /* If VAR is wider than BLEN bits, it is padded at the
3223 most-significant end. We want to set VPOS such that
3224 <BIT_FIELD_REF VAR BLEN VPOS> would refer to the
3225 least-significant BLEN bits of VAR. */
3226 if (BYTES_BIG_ENDIAN
)
3227 vpos
= size_binop (MINUS_EXPR
, TYPE_SIZE (type
), blen
);
3229 vpos
= bitsize_int (0);
3230 sra_explode_bitfield_assignment
3231 (var
, vpos
, true, &seq
, blen
, bpos
, elt
);
3234 gimple_seq_add_stmt (&seq
, st
);
3237 sra_sync_for_bitfield_assignment
3238 (&seq
, NULL
, blen
, bpos
, elt
);
3242 mark_all_v_defs_seq (seq
);
3243 sra_insert_before (gsi
, seq
);
3251 gimple_seq seq
= NULL
;
3253 /* Otherwise we need some copies. If ELT is being read, then we
3254 want to store all (modified) sub-elements back into the
3255 structure before the reference takes place. If ELT is being
3256 written, then we want to load the changed values back into
3257 our shadow variables. */
3258 /* ??? We don't check modified for reads, we just always write all of
3259 the values. We should be able to record the SSA number of the VOP
3260 for which the values were last read. If that number matches the
3261 SSA number of the VOP in the current statement, then we needn't
3262 emit an assignment. This would also eliminate double writes when
3263 a structure is passed as more than one argument to a function call.
3264 This optimization would be most effective if sra_walk_function
3265 processed the blocks in dominator order. */
3267 generate_copy_inout (elt
, is_output
, generate_element_ref (elt
), &seq
);
3270 mark_all_v_defs_seq (seq
);
3272 sra_insert_after (gsi
, seq
);
3275 sra_insert_before (gsi
, seq
);
3277 mark_no_warning (elt
);
3282 /* Scalarize a COPY. To recap, this is an assignment statement between
3283 two scalarizable references, LHS_ELT and RHS_ELT. */
3286 scalarize_copy (struct sra_elt
*lhs_elt
, struct sra_elt
*rhs_elt
,
3287 gimple_stmt_iterator
*gsi
)
3292 if (lhs_elt
->replacement
&& rhs_elt
->replacement
)
3294 /* If we have two scalar operands, modify the existing statement. */
3295 stmt
= gsi_stmt (*gsi
);
3297 /* See the commentary in sra_walk_function concerning
3298 RETURN_EXPR, and why we should never see one here. */
3299 gcc_assert (is_gimple_assign (stmt
));
3300 gcc_assert (gimple_assign_copy_p (stmt
));
3303 gimple_assign_set_lhs (stmt
, lhs_elt
->replacement
);
3304 gimple_assign_set_rhs1 (stmt
, REPLDUP (rhs_elt
->replacement
));
3307 else if (lhs_elt
->use_block_copy
|| rhs_elt
->use_block_copy
)
3309 /* If either side requires a block copy, then sync the RHS back
3310 to the original structure, leave the original assignment
3311 statement (which will perform the block copy), then load the
3312 LHS values out of its now-updated original structure. */
3313 /* ??? Could perform a modified pair-wise element copy. That
3314 would at least allow those elements that are instantiated in
3315 both structures to be optimized well. */
3318 generate_copy_inout (rhs_elt
, false,
3319 generate_element_ref (rhs_elt
), &seq
);
3322 mark_all_v_defs_seq (seq
);
3323 sra_insert_before (gsi
, seq
);
3327 generate_copy_inout (lhs_elt
, true,
3328 generate_element_ref (lhs_elt
), &seq
);
3331 mark_all_v_defs_seq (seq
);
3332 sra_insert_after (gsi
, seq
);
3337 /* Otherwise both sides must be fully instantiated. In which
3338 case perform pair-wise element assignments and replace the
3339 original block copy statement. */
3341 stmt
= gsi_stmt (*gsi
);
3342 update_stmt_if_modified (stmt
);
3345 generate_element_copy (lhs_elt
, rhs_elt
, &seq
);
3347 mark_all_v_defs_seq (seq
);
3348 sra_replace (gsi
, seq
);
3352 /* Scalarize an INIT. To recap, this is an assignment to a scalarizable
3353 reference from some form of constructor: CONSTRUCTOR, COMPLEX_CST or
3354 COMPLEX_EXPR. If RHS is NULL, it should be treated as an empty
3358 scalarize_init (struct sra_elt
*lhs_elt
, tree rhs
, gimple_stmt_iterator
*gsi
)
3361 gimple_seq seq
= NULL
, init_seq
= NULL
;
3363 /* Generate initialization statements for all members extant in the RHS. */
3366 /* Unshare the expression just in case this is from a decl's initial. */
3367 rhs
= unshare_expr (rhs
);
3368 result
= generate_element_init (lhs_elt
, rhs
, &init_seq
);
3373 /* If we failed to convert the entire initializer, then we must
3374 leave the structure assignment in place and must load values
3375 from the structure into the slots for which we did not find
3376 constants. The easiest way to do this is to generate a complete
3377 copy-out, and then follow that with the constant assignments
3378 that we were able to build. DCE will clean things up. */
3379 gimple_seq seq0
= NULL
;
3380 generate_copy_inout (lhs_elt
, true, generate_element_ref (lhs_elt
),
3382 gimple_seq_add_seq (&seq0
, seq
);
3387 /* CONSTRUCTOR is defined such that any member not mentioned is assigned
3388 a zero value. Initialize the rest of the instantiated elements. */
3389 generate_element_zero (lhs_elt
, &seq
);
3390 gimple_seq_add_seq (&seq
, init_seq
);
3393 if (lhs_elt
->use_block_copy
|| !result
)
3395 /* Since LHS is not fully instantiated, we must leave the structure
3396 assignment in place. Treating this case differently from a USE
3397 exposes constants to later optimizations. */
3400 mark_all_v_defs_seq (seq
);
3401 sra_insert_after (gsi
, seq
);
3406 /* The LHS is fully instantiated. The list of initializations
3407 replaces the original structure assignment. */
3409 update_stmt_if_modified (gsi_stmt (*gsi
));
3410 mark_all_v_defs_seq (seq
);
3411 sra_replace (gsi
, seq
);
3415 /* A subroutine of scalarize_ldst called via walk_tree. Set TREE_NO_TRAP
3416 on all INDIRECT_REFs. */
3419 mark_notrap (tree
*tp
, int *walk_subtrees
, void *data ATTRIBUTE_UNUSED
)
3423 if (TREE_CODE (t
) == INDIRECT_REF
)
3425 TREE_THIS_NOTRAP (t
) = 1;
3428 else if (IS_TYPE_OR_DECL_P (t
))
3434 /* Scalarize a LDST. To recap, this is an assignment between one scalarizable
3435 reference ELT and one non-scalarizable reference OTHER. IS_OUTPUT is true
3436 if ELT is on the left-hand side. */
3439 scalarize_ldst (struct sra_elt
*elt
, tree other
,
3440 gimple_stmt_iterator
*gsi
, bool is_output
)
3442 /* Shouldn't have gotten called for a scalar. */
3443 gcc_assert (!elt
->replacement
);
3445 if (elt
->use_block_copy
)
3447 /* Since ELT is not fully instantiated, we have to leave the
3448 block copy in place. Treat this as a USE. */
3449 scalarize_use (elt
, NULL
, gsi
, is_output
, false);
3453 /* The interesting case is when ELT is fully instantiated. In this
3454 case we can have each element stored/loaded directly to/from the
3455 corresponding slot in OTHER. This avoids a block copy. */
3457 gimple_seq seq
= NULL
;
3458 gimple stmt
= gsi_stmt (*gsi
);
3460 update_stmt_if_modified (stmt
);
3461 generate_copy_inout (elt
, is_output
, other
, &seq
);
3463 mark_all_v_defs_seq (seq
);
3465 /* Preserve EH semantics. */
3466 if (stmt_ends_bb_p (stmt
))
3468 gimple_stmt_iterator si
;
3470 gimple_seq blist
= NULL
;
3471 bool thr
= stmt_could_throw_p (stmt
);
3473 /* If the last statement of this BB created an EH edge
3474 before scalarization, we have to locate the first
3475 statement that can throw in the new statement list and
3476 use that as the last statement of this BB, such that EH
3477 semantics is preserved. All statements up to this one
3478 are added to the same BB. All other statements in the
3479 list will be added to normal outgoing edges of the same
3480 BB. If they access any memory, it's the same memory, so
3481 we can assume they won't throw. */
3482 si
= gsi_start (seq
);
3483 for (first
= gsi_stmt (si
);
3484 thr
&& !gsi_end_p (si
) && !stmt_could_throw_p (first
);
3485 first
= gsi_stmt (si
))
3487 gsi_remove (&si
, false);
3488 gimple_seq_add_stmt (&blist
, first
);
3491 /* Extract the first remaining statement from LIST, this is
3492 the EH statement if there is one. */
3493 gsi_remove (&si
, false);
3496 sra_insert_before (gsi
, blist
);
3498 /* Replace the old statement with this new representative. */
3499 gsi_replace (gsi
, first
, true);
3501 if (!gsi_end_p (si
))
3503 /* If any reference would trap, then they all would. And more
3504 to the point, the first would. Therefore none of the rest
3505 will trap since the first didn't. Indicate this by
3506 iterating over the remaining statements and set
3507 TREE_THIS_NOTRAP in all INDIRECT_REFs. */
3510 walk_gimple_stmt (&si
, NULL
, mark_notrap
, NULL
);
3513 while (!gsi_end_p (si
));
3515 insert_edge_copies_seq (seq
, gsi_bb (*gsi
));
3519 sra_replace (gsi
, seq
);
3523 /* Generate initializations for all scalarizable parameters. */
3526 scalarize_parms (void)
3528 gimple_seq seq
= NULL
;
3532 EXECUTE_IF_SET_IN_BITMAP (needs_copy_in
, 0, i
, bi
)
3534 tree var
= referenced_var (i
);
3535 struct sra_elt
*elt
= lookup_element (NULL
, var
, NULL
, NO_INSERT
);
3536 generate_copy_inout (elt
, true, var
, &seq
);
3541 insert_edge_copies_seq (seq
, ENTRY_BLOCK_PTR
);
3542 mark_all_v_defs_seq (seq
);
3546 /* Entry point to phase 4. Update the function to match replacements. */
3549 scalarize_function (void)
3551 static const struct sra_walk_fns fns
= {
3552 scalarize_use
, scalarize_copy
, scalarize_init
, scalarize_ldst
, false
3555 sra_walk_function (&fns
);
3557 gsi_commit_edge_inserts ();
3561 /* Debug helper function. Print ELT in a nice human-readable format. */
3564 dump_sra_elt_name (FILE *f
, struct sra_elt
*elt
)
3566 if (elt
->parent
&& TREE_CODE (elt
->parent
->type
) == COMPLEX_TYPE
)
3568 fputs (elt
->element
== integer_zero_node
? "__real__ " : "__imag__ ", f
);
3569 dump_sra_elt_name (f
, elt
->parent
);
3574 dump_sra_elt_name (f
, elt
->parent
);
3575 if (DECL_P (elt
->element
))
3577 if (TREE_CODE (elt
->element
) == FIELD_DECL
)
3579 print_generic_expr (f
, elt
->element
, dump_flags
);
3581 else if (TREE_CODE (elt
->element
) == BIT_FIELD_REF
)
3582 fprintf (f
, "$B" HOST_WIDE_INT_PRINT_DEC
"F" HOST_WIDE_INT_PRINT_DEC
,
3583 tree_low_cst (TREE_OPERAND (elt
->element
, 2), 1),
3584 tree_low_cst (TREE_OPERAND (elt
->element
, 1), 1));
3585 else if (TREE_CODE (elt
->element
) == RANGE_EXPR
)
3586 fprintf (f
, "["HOST_WIDE_INT_PRINT_DEC
".."HOST_WIDE_INT_PRINT_DEC
"]",
3587 TREE_INT_CST_LOW (TREE_OPERAND (elt
->element
, 0)),
3588 TREE_INT_CST_LOW (TREE_OPERAND (elt
->element
, 1)));
3590 fprintf (f
, "[" HOST_WIDE_INT_PRINT_DEC
"]",
3591 TREE_INT_CST_LOW (elt
->element
));
3595 /* Likewise, but callable from the debugger. */
3598 debug_sra_elt_name (struct sra_elt
*elt
)
3600 dump_sra_elt_name (stderr
, elt
);
3601 fputc ('\n', stderr
);
3605 sra_init_cache (void)
3607 if (sra_type_decomp_cache
)
3610 sra_type_decomp_cache
= BITMAP_ALLOC (NULL
);
3611 sra_type_inst_cache
= BITMAP_ALLOC (NULL
);
3615 /* Main entry point. */
3620 /* Initialize local variables. */
3621 gcc_obstack_init (&sra_obstack
);
3622 sra_candidates
= BITMAP_ALLOC (NULL
);
3623 needs_copy_in
= BITMAP_ALLOC (NULL
);
3625 sra_map
= htab_create (101, sra_elt_hash
, sra_elt_eq
, NULL
);
3627 /* Scan. If we find anything, instantiate and scalarize. */
3628 if (find_candidates_for_sra ())
3631 decide_instantiations ();
3632 scalarize_function ();
3635 /* Free allocated memory. */
3636 htab_delete (sra_map
);
3638 BITMAP_FREE (sra_candidates
);
3639 BITMAP_FREE (needs_copy_in
);
3640 BITMAP_FREE (sra_type_decomp_cache
);
3641 BITMAP_FREE (sra_type_inst_cache
);
3642 obstack_free (&sra_obstack
, NULL
);
3647 tree_sra_early (void)
3661 return flag_tree_sra
!= 0;
3664 struct gimple_opt_pass pass_sra_early
=
3669 gate_sra
, /* gate */
3670 tree_sra_early
, /* execute */
3673 0, /* static_pass_number */
3674 TV_TREE_SRA
, /* tv_id */
3675 PROP_cfg
| PROP_ssa
, /* properties_required */
3676 0, /* properties_provided */
3677 0, /* properties_destroyed */
3678 0, /* todo_flags_start */
3682 | TODO_verify_ssa
/* todo_flags_finish */
3686 struct gimple_opt_pass pass_sra
=
3691 gate_sra
, /* gate */
3692 tree_sra
, /* execute */
3695 0, /* static_pass_number */
3696 TV_TREE_SRA
, /* tv_id */
3697 PROP_cfg
| PROP_ssa
, /* properties_required */
3698 0, /* properties_provided */
3699 0, /* properties_destroyed */
3700 TODO_update_address_taken
, /* todo_flags_start */
3704 | TODO_verify_ssa
/* todo_flags_finish */