1 /* Tree based points-to analysis
2 Copyright (C) 2005-2013 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dberlin@dberlin.org>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
30 #include "basic-block.h"
33 #include "gimple-iterator.h"
34 #include "gimple-ssa.h"
36 #include "tree-ssanames.h"
37 #include "tree-into-ssa.h"
39 #include "tree-inline.h"
40 #include "diagnostic-core.h"
41 #include "hash-table.h"
43 #include "tree-pass.h"
44 #include "alloc-pool.h"
45 #include "splay-tree.h"
48 #include "pointer-set.h"
50 /* The idea behind this analyzer is to generate set constraints from the
51 program, then solve the resulting constraints in order to generate the
54 Set constraints are a way of modeling program analysis problems that
55 involve sets. They consist of an inclusion constraint language,
56 describing the variables (each variable is a set) and operations that
57 are involved on the variables, and a set of rules that derive facts
58 from these operations. To solve a system of set constraints, you derive
59 all possible facts under the rules, which gives you the correct sets
62 See "Efficient Field-sensitive pointer analysis for C" by "David
63 J. Pearce and Paul H. J. Kelly and Chris Hankin, at
64 http://citeseer.ist.psu.edu/pearce04efficient.html
66 Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
67 of C Code in a Second" by ""Nevin Heintze and Olivier Tardieu" at
68 http://citeseer.ist.psu.edu/heintze01ultrafast.html
70 There are three types of real constraint expressions, DEREF,
71 ADDRESSOF, and SCALAR. Each constraint expression consists
72 of a constraint type, a variable, and an offset.
74 SCALAR is a constraint expression type used to represent x, whether
75 it appears on the LHS or the RHS of a statement.
76 DEREF is a constraint expression type used to represent *x, whether
77 it appears on the LHS or the RHS of a statement.
78 ADDRESSOF is a constraint expression used to represent &x, whether
79 it appears on the LHS or the RHS of a statement.
81 Each pointer variable in the program is assigned an integer id, and
82 each field of a structure variable is assigned an integer id as well.
84 Structure variables are linked to their list of fields through a "next
85 field" in each variable that points to the next field in offset
87 Each variable for a structure field has
89 1. "size", that tells the size in bits of that field.
90 2. "fullsize, that tells the size in bits of the entire structure.
91 3. "offset", that tells the offset in bits from the beginning of the
92 structure to this field.
104 foo.a -> id 1, size 32, offset 0, fullsize 64, next foo.b
105 foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
106 bar -> id 3, size 32, offset 0, fullsize 32, next NULL
109 In order to solve the system of set constraints, the following is
112 1. Each constraint variable x has a solution set associated with it,
115 2. Constraints are separated into direct, copy, and complex.
116 Direct constraints are ADDRESSOF constraints that require no extra
117 processing, such as P = &Q
118 Copy constraints are those of the form P = Q.
119 Complex constraints are all the constraints involving dereferences
120 and offsets (including offsetted copies).
122 3. All direct constraints of the form P = &Q are processed, such
123 that Q is added to Sol(P)
125 4. All complex constraints for a given constraint variable are stored in a
126 linked list attached to that variable's node.
128 5. A directed graph is built out of the copy constraints. Each
129 constraint variable is a node in the graph, and an edge from
130 Q to P is added for each copy constraint of the form P = Q
132 6. The graph is then walked, and solution sets are
133 propagated along the copy edges, such that an edge from Q to P
134 causes Sol(P) <- Sol(P) union Sol(Q).
136 7. As we visit each node, all complex constraints associated with
137 that node are processed by adding appropriate copy edges to the graph, or the
138 appropriate variables to the solution set.
140 8. The process of walking the graph is iterated until no solution
143 Prior to walking the graph in steps 6 and 7, We perform static
144 cycle elimination on the constraint graph, as well
145 as off-line variable substitution.
147 TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
148 on and turned into anything), but isn't. You can just see what offset
149 inside the pointed-to struct it's going to access.
151 TODO: Constant bounded arrays can be handled as if they were structs of the
152 same number of elements.
154 TODO: Modeling heap and incoming pointers becomes much better if we
155 add fields to them as we discover them, which we could do.
157 TODO: We could handle unions, but to be honest, it's probably not
158 worth the pain or slowdown. */
160 /* IPA-PTA optimizations possible.
162 When the indirect function called is ANYTHING we can add disambiguation
163 based on the function signatures (or simply the parameter count which
164 is the varinfo size). We also do not need to consider functions that
165 do not have their address taken.
167 The is_global_var bit which marks escape points is overly conservative
168 in IPA mode. Split it to is_escape_point and is_global_var - only
169 externally visible globals are escape points in IPA mode. This is
170 also needed to fix the pt_solution_includes_global predicate
171 (and thus ptr_deref_may_alias_global_p).
173 The way we introduce DECL_PT_UID to avoid fixing up all points-to
174 sets in the translation unit when we copy a DECL during inlining
175 pessimizes precision. The advantage is that the DECL_PT_UID keeps
176 compile-time and memory usage overhead low - the points-to sets
177 do not grow or get unshared as they would during a fixup phase.
178 An alternative solution is to delay IPA PTA until after all
179 inlining transformations have been applied.
181 The way we propagate clobber/use information isn't optimized.
182 It should use a new complex constraint that properly filters
183 out local variables of the callee (though that would make
184 the sets invalid after inlining). OTOH we might as well
185 admit defeat to WHOPR and simply do all the clobber/use analysis
186 and propagation after PTA finished but before we threw away
187 points-to information for memory variables. WHOPR and PTA
188 do not play along well anyway - the whole constraint solving
189 would need to be done in WPA phase and it will be very interesting
190 to apply the results to local SSA names during LTRANS phase.
192 We probably should compute a per-function unit-ESCAPE solution
193 propagating it simply like the clobber / uses solutions. The
194 solution can go alongside the non-IPA espaced solution and be
195 used to query which vars escape the unit through a function.
197 We never put function decls in points-to sets so we do not
198 keep the set of called functions for indirect calls.
200 And probably more. */
202 static bool use_field_sensitive
= true;
203 static int in_ipa_mode
= 0;
205 /* Used for predecessor bitmaps. */
206 static bitmap_obstack predbitmap_obstack
;
208 /* Used for points-to sets. */
209 static bitmap_obstack pta_obstack
;
211 /* Used for oldsolution members of variables. */
212 static bitmap_obstack oldpta_obstack
;
214 /* Used for per-solver-iteration bitmaps. */
215 static bitmap_obstack iteration_obstack
;
217 static unsigned int create_variable_info_for (tree
, const char *);
218 typedef struct constraint_graph
*constraint_graph_t
;
219 static void unify_nodes (constraint_graph_t
, unsigned int, unsigned int, bool);
222 typedef struct constraint
*constraint_t
;
225 #define EXECUTE_IF_IN_NONNULL_BITMAP(a, b, c, d) \
227 EXECUTE_IF_SET_IN_BITMAP (a, b, c, d)
229 static struct constraint_stats
231 unsigned int total_vars
;
232 unsigned int nonpointer_vars
;
233 unsigned int unified_vars_static
;
234 unsigned int unified_vars_dynamic
;
235 unsigned int iterations
;
236 unsigned int num_edges
;
237 unsigned int num_implicit_edges
;
238 unsigned int points_to_sets_created
;
243 /* ID of this variable */
246 /* True if this is a variable created by the constraint analysis, such as
247 heap variables and constraints we had to break up. */
248 unsigned int is_artificial_var
: 1;
250 /* True if this is a special variable whose solution set should not be
252 unsigned int is_special_var
: 1;
254 /* True for variables whose size is not known or variable. */
255 unsigned int is_unknown_size_var
: 1;
257 /* True for (sub-)fields that represent a whole variable. */
258 unsigned int is_full_var
: 1;
260 /* True if this is a heap variable. */
261 unsigned int is_heap_var
: 1;
263 /* True if this field may contain pointers. */
264 unsigned int may_have_pointers
: 1;
266 /* True if this field has only restrict qualified pointers. */
267 unsigned int only_restrict_pointers
: 1;
269 /* True if this represents a global variable. */
270 unsigned int is_global_var
: 1;
272 /* True if this represents a IPA function info. */
273 unsigned int is_fn_info
: 1;
275 /* The ID of the variable for the next field in this structure
276 or zero for the last field in this structure. */
279 /* The ID of the variable for the first field in this structure. */
282 /* Offset of this variable, in bits, from the base variable */
283 unsigned HOST_WIDE_INT offset
;
285 /* Size of the variable, in bits. */
286 unsigned HOST_WIDE_INT size
;
288 /* Full size of the base variable, in bits. */
289 unsigned HOST_WIDE_INT fullsize
;
291 /* Name of this variable */
294 /* Tree that this variable is associated with. */
297 /* Points-to set for this variable. */
300 /* Old points-to set for this variable. */
303 typedef struct variable_info
*varinfo_t
;
305 static varinfo_t
first_vi_for_offset (varinfo_t
, unsigned HOST_WIDE_INT
);
306 static varinfo_t
first_or_preceding_vi_for_offset (varinfo_t
,
307 unsigned HOST_WIDE_INT
);
308 static varinfo_t
lookup_vi_for_tree (tree
);
309 static inline bool type_can_have_subvars (const_tree
);
311 /* Pool of variable info structures. */
312 static alloc_pool variable_info_pool
;
314 /* Map varinfo to final pt_solution. */
315 static pointer_map_t
*final_solutions
;
316 struct obstack final_solutions_obstack
;
318 /* Table of variable info structures for constraint variables.
319 Indexed directly by variable info id. */
320 static vec
<varinfo_t
> varmap
;
322 /* Return the varmap element N */
324 static inline varinfo_t
325 get_varinfo (unsigned int n
)
330 /* Return the next variable in the list of sub-variables of VI
331 or NULL if VI is the last sub-variable. */
333 static inline varinfo_t
334 vi_next (varinfo_t vi
)
336 return get_varinfo (vi
->next
);
339 /* Static IDs for the special variables. Variable ID zero is unused
340 and used as terminator for the sub-variable chain. */
341 enum { nothing_id
= 1, anything_id
= 2, readonly_id
= 3,
342 escaped_id
= 4, nonlocal_id
= 5,
343 storedanything_id
= 6, integer_id
= 7 };
345 /* Return a new variable info structure consisting for a variable
346 named NAME, and using constraint graph node NODE. Append it
347 to the vector of variable info structures. */
350 new_var_info (tree t
, const char *name
)
352 unsigned index
= varmap
.length ();
353 varinfo_t ret
= (varinfo_t
) pool_alloc (variable_info_pool
);
358 /* Vars without decl are artificial and do not have sub-variables. */
359 ret
->is_artificial_var
= (t
== NULL_TREE
);
360 ret
->is_special_var
= false;
361 ret
->is_unknown_size_var
= false;
362 ret
->is_full_var
= (t
== NULL_TREE
);
363 ret
->is_heap_var
= false;
364 ret
->may_have_pointers
= true;
365 ret
->only_restrict_pointers
= false;
366 ret
->is_global_var
= (t
== NULL_TREE
);
367 ret
->is_fn_info
= false;
369 ret
->is_global_var
= (is_global_var (t
)
370 /* We have to treat even local register variables
372 || (TREE_CODE (t
) == VAR_DECL
373 && DECL_HARD_REGISTER (t
)));
374 ret
->solution
= BITMAP_ALLOC (&pta_obstack
);
375 ret
->oldsolution
= NULL
;
381 varmap
.safe_push (ret
);
387 /* A map mapping call statements to per-stmt variables for uses
388 and clobbers specific to the call. */
389 static struct pointer_map_t
*call_stmt_vars
;
391 /* Lookup or create the variable for the call statement CALL. */
394 get_call_vi (gimple call
)
399 slot_p
= pointer_map_insert (call_stmt_vars
, call
);
401 return (varinfo_t
) *slot_p
;
403 vi
= new_var_info (NULL_TREE
, "CALLUSED");
407 vi
->is_full_var
= true;
409 vi2
= new_var_info (NULL_TREE
, "CALLCLOBBERED");
413 vi2
->is_full_var
= true;
417 *slot_p
= (void *) vi
;
421 /* Lookup the variable for the call statement CALL representing
422 the uses. Returns NULL if there is nothing special about this call. */
425 lookup_call_use_vi (gimple call
)
429 slot_p
= pointer_map_contains (call_stmt_vars
, call
);
431 return (varinfo_t
) *slot_p
;
436 /* Lookup the variable for the call statement CALL representing
437 the clobbers. Returns NULL if there is nothing special about this call. */
440 lookup_call_clobber_vi (gimple call
)
442 varinfo_t uses
= lookup_call_use_vi (call
);
446 return vi_next (uses
);
449 /* Lookup or create the variable for the call statement CALL representing
453 get_call_use_vi (gimple call
)
455 return get_call_vi (call
);
458 /* Lookup or create the variable for the call statement CALL representing
461 static varinfo_t ATTRIBUTE_UNUSED
462 get_call_clobber_vi (gimple call
)
464 return vi_next (get_call_vi (call
));
468 typedef enum {SCALAR
, DEREF
, ADDRESSOF
} constraint_expr_type
;
470 /* An expression that appears in a constraint. */
472 struct constraint_expr
474 /* Constraint type. */
475 constraint_expr_type type
;
477 /* Variable we are referring to in the constraint. */
480 /* Offset, in bits, of this constraint from the beginning of
481 variables it ends up referring to.
483 IOW, in a deref constraint, we would deref, get the result set,
484 then add OFFSET to each member. */
485 HOST_WIDE_INT offset
;
488 /* Use 0x8000... as special unknown offset. */
489 #define UNKNOWN_OFFSET HOST_WIDE_INT_MIN
491 typedef struct constraint_expr ce_s
;
492 static void get_constraint_for_1 (tree
, vec
<ce_s
> *, bool, bool);
493 static void get_constraint_for (tree
, vec
<ce_s
> *);
494 static void get_constraint_for_rhs (tree
, vec
<ce_s
> *);
495 static void do_deref (vec
<ce_s
> *);
497 /* Our set constraints are made up of two constraint expressions, one
500 As described in the introduction, our set constraints each represent an
501 operation between set valued variables.
505 struct constraint_expr lhs
;
506 struct constraint_expr rhs
;
509 /* List of constraints that we use to build the constraint graph from. */
511 static vec
<constraint_t
> constraints
;
512 static alloc_pool constraint_pool
;
514 /* The constraint graph is represented as an array of bitmaps
515 containing successor nodes. */
517 struct constraint_graph
519 /* Size of this graph, which may be different than the number of
520 nodes in the variable map. */
523 /* Explicit successors of each node. */
526 /* Implicit predecessors of each node (Used for variable
528 bitmap
*implicit_preds
;
530 /* Explicit predecessors of each node (Used for variable substitution). */
533 /* Indirect cycle representatives, or -1 if the node has no indirect
535 int *indirect_cycles
;
537 /* Representative node for a node. rep[a] == a unless the node has
541 /* Equivalence class representative for a label. This is used for
542 variable substitution. */
545 /* Pointer equivalence label for a node. All nodes with the same
546 pointer equivalence label can be unified together at some point
547 (either during constraint optimization or after the constraint
551 /* Pointer equivalence representative for a label. This is used to
552 handle nodes that are pointer equivalent but not location
553 equivalent. We can unite these once the addressof constraints
554 are transformed into initial points-to sets. */
557 /* Pointer equivalence label for each node, used during variable
559 unsigned int *pointer_label
;
561 /* Location equivalence label for each node, used during location
562 equivalence finding. */
563 unsigned int *loc_label
;
565 /* Pointed-by set for each node, used during location equivalence
566 finding. This is pointed-by rather than pointed-to, because it
567 is constructed using the predecessor graph. */
570 /* Points to sets for pointer equivalence. This is *not* the actual
571 points-to sets for nodes. */
574 /* Bitmap of nodes where the bit is set if the node is a direct
575 node. Used for variable substitution. */
576 sbitmap direct_nodes
;
578 /* Bitmap of nodes where the bit is set if the node is address
579 taken. Used for variable substitution. */
580 bitmap address_taken
;
582 /* Vector of complex constraints for each graph node. Complex
583 constraints are those involving dereferences or offsets that are
585 vec
<constraint_t
> *complex;
588 static constraint_graph_t graph
;
590 /* During variable substitution and the offline version of indirect
591 cycle finding, we create nodes to represent dereferences and
592 address taken constraints. These represent where these start and
594 #define FIRST_REF_NODE (varmap).length ()
595 #define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
597 /* Return the representative node for NODE, if NODE has been unioned
599 This function performs path compression along the way to finding
600 the representative. */
603 find (unsigned int node
)
605 gcc_checking_assert (node
< graph
->size
);
606 if (graph
->rep
[node
] != node
)
607 return graph
->rep
[node
] = find (graph
->rep
[node
]);
611 /* Union the TO and FROM nodes to the TO nodes.
612 Note that at some point in the future, we may want to do
613 union-by-rank, in which case we are going to have to return the
614 node we unified to. */
617 unite (unsigned int to
, unsigned int from
)
619 gcc_checking_assert (to
< graph
->size
&& from
< graph
->size
);
620 if (to
!= from
&& graph
->rep
[from
] != to
)
622 graph
->rep
[from
] = to
;
628 /* Create a new constraint consisting of LHS and RHS expressions. */
631 new_constraint (const struct constraint_expr lhs
,
632 const struct constraint_expr rhs
)
634 constraint_t ret
= (constraint_t
) pool_alloc (constraint_pool
);
640 /* Print out constraint C to FILE. */
643 dump_constraint (FILE *file
, constraint_t c
)
645 if (c
->lhs
.type
== ADDRESSOF
)
647 else if (c
->lhs
.type
== DEREF
)
649 fprintf (file
, "%s", get_varinfo (c
->lhs
.var
)->name
);
650 if (c
->lhs
.offset
== UNKNOWN_OFFSET
)
651 fprintf (file
, " + UNKNOWN");
652 else if (c
->lhs
.offset
!= 0)
653 fprintf (file
, " + " HOST_WIDE_INT_PRINT_DEC
, c
->lhs
.offset
);
654 fprintf (file
, " = ");
655 if (c
->rhs
.type
== ADDRESSOF
)
657 else if (c
->rhs
.type
== DEREF
)
659 fprintf (file
, "%s", get_varinfo (c
->rhs
.var
)->name
);
660 if (c
->rhs
.offset
== UNKNOWN_OFFSET
)
661 fprintf (file
, " + UNKNOWN");
662 else if (c
->rhs
.offset
!= 0)
663 fprintf (file
, " + " HOST_WIDE_INT_PRINT_DEC
, c
->rhs
.offset
);
667 void debug_constraint (constraint_t
);
668 void debug_constraints (void);
669 void debug_constraint_graph (void);
670 void debug_solution_for_var (unsigned int);
671 void debug_sa_points_to_info (void);
673 /* Print out constraint C to stderr. */
676 debug_constraint (constraint_t c
)
678 dump_constraint (stderr
, c
);
679 fprintf (stderr
, "\n");
682 /* Print out all constraints to FILE */
685 dump_constraints (FILE *file
, int from
)
689 for (i
= from
; constraints
.iterate (i
, &c
); i
++)
692 dump_constraint (file
, c
);
693 fprintf (file
, "\n");
697 /* Print out all constraints to stderr. */
700 debug_constraints (void)
702 dump_constraints (stderr
, 0);
705 /* Print the constraint graph in dot format. */
708 dump_constraint_graph (FILE *file
)
712 /* Only print the graph if it has already been initialized: */
716 /* Prints the header of the dot file: */
717 fprintf (file
, "strict digraph {\n");
718 fprintf (file
, " node [\n shape = box\n ]\n");
719 fprintf (file
, " edge [\n fontsize = \"12\"\n ]\n");
720 fprintf (file
, "\n // List of nodes and complex constraints in "
721 "the constraint graph:\n");
723 /* The next lines print the nodes in the graph together with the
724 complex constraints attached to them. */
725 for (i
= 1; i
< graph
->size
; i
++)
727 if (i
== FIRST_REF_NODE
)
731 if (i
< FIRST_REF_NODE
)
732 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
734 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
735 if (graph
->complex[i
].exists ())
739 fprintf (file
, " [label=\"\\N\\n");
740 for (j
= 0; graph
->complex[i
].iterate (j
, &c
); ++j
)
742 dump_constraint (file
, c
);
743 fprintf (file
, "\\l");
745 fprintf (file
, "\"]");
747 fprintf (file
, ";\n");
750 /* Go over the edges. */
751 fprintf (file
, "\n // Edges in the constraint graph:\n");
752 for (i
= 1; i
< graph
->size
; i
++)
758 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[i
], 0, j
, bi
)
760 unsigned to
= find (j
);
763 if (i
< FIRST_REF_NODE
)
764 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
766 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
767 fprintf (file
, " -> ");
768 if (to
< FIRST_REF_NODE
)
769 fprintf (file
, "\"%s\"", get_varinfo (to
)->name
);
771 fprintf (file
, "\"*%s\"", get_varinfo (to
- FIRST_REF_NODE
)->name
);
772 fprintf (file
, ";\n");
776 /* Prints the tail of the dot file. */
777 fprintf (file
, "}\n");
780 /* Print out the constraint graph to stderr. */
783 debug_constraint_graph (void)
785 dump_constraint_graph (stderr
);
790 The solver is a simple worklist solver, that works on the following
793 sbitmap changed_nodes = all zeroes;
795 For each node that is not already collapsed:
797 set bit in changed nodes
799 while (changed_count > 0)
801 compute topological ordering for constraint graph
803 find and collapse cycles in the constraint graph (updating
804 changed if necessary)
806 for each node (n) in the graph in topological order:
809 Process each complex constraint associated with the node,
810 updating changed if necessary.
812 For each outgoing edge from n, propagate the solution from n to
813 the destination of the edge, updating changed as necessary.
817 /* Return true if two constraint expressions A and B are equal. */
820 constraint_expr_equal (struct constraint_expr a
, struct constraint_expr b
)
822 return a
.type
== b
.type
&& a
.var
== b
.var
&& a
.offset
== b
.offset
;
825 /* Return true if constraint expression A is less than constraint expression
826 B. This is just arbitrary, but consistent, in order to give them an
830 constraint_expr_less (struct constraint_expr a
, struct constraint_expr b
)
832 if (a
.type
== b
.type
)
835 return a
.offset
< b
.offset
;
837 return a
.var
< b
.var
;
840 return a
.type
< b
.type
;
843 /* Return true if constraint A is less than constraint B. This is just
844 arbitrary, but consistent, in order to give them an ordering. */
847 constraint_less (const constraint_t
&a
, const constraint_t
&b
)
849 if (constraint_expr_less (a
->lhs
, b
->lhs
))
851 else if (constraint_expr_less (b
->lhs
, a
->lhs
))
854 return constraint_expr_less (a
->rhs
, b
->rhs
);
857 /* Return true if two constraints A and B are equal. */
860 constraint_equal (struct constraint a
, struct constraint b
)
862 return constraint_expr_equal (a
.lhs
, b
.lhs
)
863 && constraint_expr_equal (a
.rhs
, b
.rhs
);
867 /* Find a constraint LOOKFOR in the sorted constraint vector VEC */
870 constraint_vec_find (vec
<constraint_t
> vec
,
871 struct constraint lookfor
)
879 place
= vec
.lower_bound (&lookfor
, constraint_less
);
880 if (place
>= vec
.length ())
883 if (!constraint_equal (*found
, lookfor
))
888 /* Union two constraint vectors, TO and FROM. Put the result in TO. */
891 constraint_set_union (vec
<constraint_t
> *to
,
892 vec
<constraint_t
> *from
)
897 FOR_EACH_VEC_ELT (*from
, i
, c
)
899 if (constraint_vec_find (*to
, *c
) == NULL
)
901 unsigned int place
= to
->lower_bound (c
, constraint_less
);
902 to
->safe_insert (place
, c
);
907 /* Expands the solution in SET to all sub-fields of variables included. */
910 solution_set_expand (bitmap set
)
915 /* In a first pass expand to the head of the variables we need to
916 add all sub-fields off. This avoids quadratic behavior. */
917 EXECUTE_IF_SET_IN_BITMAP (set
, 0, j
, bi
)
919 varinfo_t v
= get_varinfo (j
);
920 if (v
->is_artificial_var
923 bitmap_set_bit (set
, v
->head
);
926 /* In the second pass now expand all head variables with subfields. */
927 EXECUTE_IF_SET_IN_BITMAP (set
, 0, j
, bi
)
929 varinfo_t v
= get_varinfo (j
);
930 if (v
->is_artificial_var
934 for (v
= vi_next (v
); v
!= NULL
; v
= vi_next (v
))
935 bitmap_set_bit (set
, v
->id
);
939 /* Union solution sets TO and FROM, and add INC to each member of FROM in the
943 set_union_with_increment (bitmap to
, bitmap from
, HOST_WIDE_INT inc
)
945 bool changed
= false;
949 /* If the solution of FROM contains anything it is good enough to transfer
951 if (bitmap_bit_p (from
, anything_id
))
952 return bitmap_set_bit (to
, anything_id
);
954 /* For zero offset simply union the solution into the destination. */
956 return bitmap_ior_into (to
, from
);
958 /* If the offset is unknown we have to expand the solution to
960 if (inc
== UNKNOWN_OFFSET
)
962 bitmap tmp
= BITMAP_ALLOC (&iteration_obstack
);
963 bitmap_copy (tmp
, from
);
964 solution_set_expand (tmp
);
965 changed
|= bitmap_ior_into (to
, tmp
);
970 /* For non-zero offset union the offsetted solution into the destination. */
971 EXECUTE_IF_SET_IN_BITMAP (from
, 0, i
, bi
)
973 varinfo_t vi
= get_varinfo (i
);
975 /* If this is a variable with just one field just set its bit
977 if (vi
->is_artificial_var
978 || vi
->is_unknown_size_var
980 changed
|= bitmap_set_bit (to
, i
);
983 unsigned HOST_WIDE_INT fieldoffset
= vi
->offset
+ inc
;
985 /* If the offset makes the pointer point to before the
986 variable use offset zero for the field lookup. */
988 && fieldoffset
> vi
->offset
)
991 vi
= first_or_preceding_vi_for_offset (vi
, fieldoffset
);
993 changed
|= bitmap_set_bit (to
, vi
->id
);
994 /* If the result is not exactly at fieldoffset include the next
995 field as well. See get_constraint_for_ptr_offset for more
997 if (vi
->offset
!= fieldoffset
999 changed
|= bitmap_set_bit (to
, vi
->next
);
1006 /* Insert constraint C into the list of complex constraints for graph
1010 insert_into_complex (constraint_graph_t graph
,
1011 unsigned int var
, constraint_t c
)
1013 vec
<constraint_t
> complex = graph
->complex[var
];
1014 unsigned int place
= complex.lower_bound (c
, constraint_less
);
1016 /* Only insert constraints that do not already exist. */
1017 if (place
>= complex.length ()
1018 || !constraint_equal (*c
, *complex[place
]))
1019 graph
->complex[var
].safe_insert (place
, c
);
1023 /* Condense two variable nodes into a single variable node, by moving
1024 all associated info from SRC to TO. */
1027 merge_node_constraints (constraint_graph_t graph
, unsigned int to
,
1033 gcc_checking_assert (find (from
) == to
);
1035 /* Move all complex constraints from src node into to node */
1036 FOR_EACH_VEC_ELT (graph
->complex[from
], i
, c
)
1038 /* In complex constraints for node src, we may have either
1039 a = *src, and *src = a, or an offseted constraint which are
1040 always added to the rhs node's constraints. */
1042 if (c
->rhs
.type
== DEREF
)
1044 else if (c
->lhs
.type
== DEREF
)
1049 constraint_set_union (&graph
->complex[to
], &graph
->complex[from
]);
1050 graph
->complex[from
].release ();
1054 /* Remove edges involving NODE from GRAPH. */
1057 clear_edges_for_node (constraint_graph_t graph
, unsigned int node
)
1059 if (graph
->succs
[node
])
1060 BITMAP_FREE (graph
->succs
[node
]);
1063 /* Merge GRAPH nodes FROM and TO into node TO. */
1066 merge_graph_nodes (constraint_graph_t graph
, unsigned int to
,
1069 if (graph
->indirect_cycles
[from
] != -1)
1071 /* If we have indirect cycles with the from node, and we have
1072 none on the to node, the to node has indirect cycles from the
1073 from node now that they are unified.
1074 If indirect cycles exist on both, unify the nodes that they
1075 are in a cycle with, since we know they are in a cycle with
1077 if (graph
->indirect_cycles
[to
] == -1)
1078 graph
->indirect_cycles
[to
] = graph
->indirect_cycles
[from
];
1081 /* Merge all the successor edges. */
1082 if (graph
->succs
[from
])
1084 if (!graph
->succs
[to
])
1085 graph
->succs
[to
] = BITMAP_ALLOC (&pta_obstack
);
1086 bitmap_ior_into (graph
->succs
[to
],
1087 graph
->succs
[from
]);
1090 clear_edges_for_node (graph
, from
);
1094 /* Add an indirect graph edge to GRAPH, going from TO to FROM if
1095 it doesn't exist in the graph already. */
1098 add_implicit_graph_edge (constraint_graph_t graph
, unsigned int to
,
1104 if (!graph
->implicit_preds
[to
])
1105 graph
->implicit_preds
[to
] = BITMAP_ALLOC (&predbitmap_obstack
);
1107 if (bitmap_set_bit (graph
->implicit_preds
[to
], from
))
1108 stats
.num_implicit_edges
++;
1111 /* Add a predecessor graph edge to GRAPH, going from TO to FROM if
1112 it doesn't exist in the graph already.
1113 Return false if the edge already existed, true otherwise. */
1116 add_pred_graph_edge (constraint_graph_t graph
, unsigned int to
,
1119 if (!graph
->preds
[to
])
1120 graph
->preds
[to
] = BITMAP_ALLOC (&predbitmap_obstack
);
1121 bitmap_set_bit (graph
->preds
[to
], from
);
1124 /* Add a graph edge to GRAPH, going from FROM to TO if
1125 it doesn't exist in the graph already.
1126 Return false if the edge already existed, true otherwise. */
1129 add_graph_edge (constraint_graph_t graph
, unsigned int to
,
1140 if (!graph
->succs
[from
])
1141 graph
->succs
[from
] = BITMAP_ALLOC (&pta_obstack
);
1142 if (bitmap_set_bit (graph
->succs
[from
], to
))
1145 if (to
< FIRST_REF_NODE
&& from
< FIRST_REF_NODE
)
1153 /* Initialize the constraint graph structure to contain SIZE nodes. */
1156 init_graph (unsigned int size
)
1160 graph
= XCNEW (struct constraint_graph
);
1162 graph
->succs
= XCNEWVEC (bitmap
, graph
->size
);
1163 graph
->indirect_cycles
= XNEWVEC (int, graph
->size
);
1164 graph
->rep
= XNEWVEC (unsigned int, graph
->size
);
1165 /* ??? Macros do not support template types with multiple arguments,
1166 so we use a typedef to work around it. */
1167 typedef vec
<constraint_t
> vec_constraint_t_heap
;
1168 graph
->complex = XCNEWVEC (vec_constraint_t_heap
, size
);
1169 graph
->pe
= XCNEWVEC (unsigned int, graph
->size
);
1170 graph
->pe_rep
= XNEWVEC (int, graph
->size
);
1172 for (j
= 0; j
< graph
->size
; j
++)
1175 graph
->pe_rep
[j
] = -1;
1176 graph
->indirect_cycles
[j
] = -1;
1180 /* Build the constraint graph, adding only predecessor edges right now. */
1183 build_pred_graph (void)
1189 graph
->implicit_preds
= XCNEWVEC (bitmap
, graph
->size
);
1190 graph
->preds
= XCNEWVEC (bitmap
, graph
->size
);
1191 graph
->pointer_label
= XCNEWVEC (unsigned int, graph
->size
);
1192 graph
->loc_label
= XCNEWVEC (unsigned int, graph
->size
);
1193 graph
->pointed_by
= XCNEWVEC (bitmap
, graph
->size
);
1194 graph
->points_to
= XCNEWVEC (bitmap
, graph
->size
);
1195 graph
->eq_rep
= XNEWVEC (int, graph
->size
);
1196 graph
->direct_nodes
= sbitmap_alloc (graph
->size
);
1197 graph
->address_taken
= BITMAP_ALLOC (&predbitmap_obstack
);
1198 bitmap_clear (graph
->direct_nodes
);
1200 for (j
= 1; j
< FIRST_REF_NODE
; j
++)
1202 if (!get_varinfo (j
)->is_special_var
)
1203 bitmap_set_bit (graph
->direct_nodes
, j
);
1206 for (j
= 0; j
< graph
->size
; j
++)
1207 graph
->eq_rep
[j
] = -1;
1209 for (j
= 0; j
< varmap
.length (); j
++)
1210 graph
->indirect_cycles
[j
] = -1;
1212 FOR_EACH_VEC_ELT (constraints
, i
, c
)
1214 struct constraint_expr lhs
= c
->lhs
;
1215 struct constraint_expr rhs
= c
->rhs
;
1216 unsigned int lhsvar
= lhs
.var
;
1217 unsigned int rhsvar
= rhs
.var
;
1219 if (lhs
.type
== DEREF
)
1222 if (rhs
.offset
== 0 && lhs
.offset
== 0 && rhs
.type
== SCALAR
)
1223 add_pred_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1225 else if (rhs
.type
== DEREF
)
1228 if (rhs
.offset
== 0 && lhs
.offset
== 0 && lhs
.type
== SCALAR
)
1229 add_pred_graph_edge (graph
, lhsvar
, FIRST_REF_NODE
+ rhsvar
);
1231 bitmap_clear_bit (graph
->direct_nodes
, lhsvar
);
1233 else if (rhs
.type
== ADDRESSOF
)
1238 if (graph
->points_to
[lhsvar
] == NULL
)
1239 graph
->points_to
[lhsvar
] = BITMAP_ALLOC (&predbitmap_obstack
);
1240 bitmap_set_bit (graph
->points_to
[lhsvar
], rhsvar
);
1242 if (graph
->pointed_by
[rhsvar
] == NULL
)
1243 graph
->pointed_by
[rhsvar
] = BITMAP_ALLOC (&predbitmap_obstack
);
1244 bitmap_set_bit (graph
->pointed_by
[rhsvar
], lhsvar
);
1246 /* Implicitly, *x = y */
1247 add_implicit_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1249 /* All related variables are no longer direct nodes. */
1250 bitmap_clear_bit (graph
->direct_nodes
, rhsvar
);
1251 v
= get_varinfo (rhsvar
);
1252 if (!v
->is_full_var
)
1254 v
= get_varinfo (v
->head
);
1257 bitmap_clear_bit (graph
->direct_nodes
, v
->id
);
1262 bitmap_set_bit (graph
->address_taken
, rhsvar
);
1264 else if (lhsvar
> anything_id
1265 && lhsvar
!= rhsvar
&& lhs
.offset
== 0 && rhs
.offset
== 0)
1268 add_pred_graph_edge (graph
, lhsvar
, rhsvar
);
1269 /* Implicitly, *x = *y */
1270 add_implicit_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
,
1271 FIRST_REF_NODE
+ rhsvar
);
1273 else if (lhs
.offset
!= 0 || rhs
.offset
!= 0)
1275 if (rhs
.offset
!= 0)
1276 bitmap_clear_bit (graph
->direct_nodes
, lhs
.var
);
1277 else if (lhs
.offset
!= 0)
1278 bitmap_clear_bit (graph
->direct_nodes
, rhs
.var
);
1283 /* Build the constraint graph, adding successor edges. */
1286 build_succ_graph (void)
1291 FOR_EACH_VEC_ELT (constraints
, i
, c
)
1293 struct constraint_expr lhs
;
1294 struct constraint_expr rhs
;
1295 unsigned int lhsvar
;
1296 unsigned int rhsvar
;
1303 lhsvar
= find (lhs
.var
);
1304 rhsvar
= find (rhs
.var
);
1306 if (lhs
.type
== DEREF
)
1308 if (rhs
.offset
== 0 && lhs
.offset
== 0 && rhs
.type
== SCALAR
)
1309 add_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1311 else if (rhs
.type
== DEREF
)
1313 if (rhs
.offset
== 0 && lhs
.offset
== 0 && lhs
.type
== SCALAR
)
1314 add_graph_edge (graph
, lhsvar
, FIRST_REF_NODE
+ rhsvar
);
1316 else if (rhs
.type
== ADDRESSOF
)
1319 gcc_checking_assert (find (rhs
.var
) == rhs
.var
);
1320 bitmap_set_bit (get_varinfo (lhsvar
)->solution
, rhsvar
);
1322 else if (lhsvar
> anything_id
1323 && lhsvar
!= rhsvar
&& lhs
.offset
== 0 && rhs
.offset
== 0)
1325 add_graph_edge (graph
, lhsvar
, rhsvar
);
1329 /* Add edges from STOREDANYTHING to all non-direct nodes that can
1330 receive pointers. */
1331 t
= find (storedanything_id
);
1332 for (i
= integer_id
+ 1; i
< FIRST_REF_NODE
; ++i
)
1334 if (!bitmap_bit_p (graph
->direct_nodes
, i
)
1335 && get_varinfo (i
)->may_have_pointers
)
1336 add_graph_edge (graph
, find (i
), t
);
1339 /* Everything stored to ANYTHING also potentially escapes. */
1340 add_graph_edge (graph
, find (escaped_id
), t
);
1344 /* Changed variables on the last iteration. */
1345 static bitmap changed
;
1347 /* Strongly Connected Component visitation info. */
1354 unsigned int *node_mapping
;
1356 vec
<unsigned> scc_stack
;
1360 /* Recursive routine to find strongly connected components in GRAPH.
1361 SI is the SCC info to store the information in, and N is the id of current
1362 graph node we are processing.
1364 This is Tarjan's strongly connected component finding algorithm, as
1365 modified by Nuutila to keep only non-root nodes on the stack.
1366 The algorithm can be found in "On finding the strongly connected
1367 connected components in a directed graph" by Esko Nuutila and Eljas
1368 Soisalon-Soininen, in Information Processing Letters volume 49,
1369 number 1, pages 9-14. */
1372 scc_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
1376 unsigned int my_dfs
;
1378 bitmap_set_bit (si
->visited
, n
);
1379 si
->dfs
[n
] = si
->current_index
++;
1380 my_dfs
= si
->dfs
[n
];
1382 /* Visit all the successors. */
1383 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[n
], 0, i
, bi
)
1387 if (i
> LAST_REF_NODE
)
1391 if (bitmap_bit_p (si
->deleted
, w
))
1394 if (!bitmap_bit_p (si
->visited
, w
))
1395 scc_visit (graph
, si
, w
);
1397 unsigned int t
= find (w
);
1398 gcc_checking_assert (find (n
) == n
);
1399 if (si
->dfs
[t
] < si
->dfs
[n
])
1400 si
->dfs
[n
] = si
->dfs
[t
];
1403 /* See if any components have been identified. */
1404 if (si
->dfs
[n
] == my_dfs
)
1406 if (si
->scc_stack
.length () > 0
1407 && si
->dfs
[si
->scc_stack
.last ()] >= my_dfs
)
1409 bitmap scc
= BITMAP_ALLOC (NULL
);
1410 unsigned int lowest_node
;
1413 bitmap_set_bit (scc
, n
);
1415 while (si
->scc_stack
.length () != 0
1416 && si
->dfs
[si
->scc_stack
.last ()] >= my_dfs
)
1418 unsigned int w
= si
->scc_stack
.pop ();
1420 bitmap_set_bit (scc
, w
);
1423 lowest_node
= bitmap_first_set_bit (scc
);
1424 gcc_assert (lowest_node
< FIRST_REF_NODE
);
1426 /* Collapse the SCC nodes into a single node, and mark the
1428 EXECUTE_IF_SET_IN_BITMAP (scc
, 0, i
, bi
)
1430 if (i
< FIRST_REF_NODE
)
1432 if (unite (lowest_node
, i
))
1433 unify_nodes (graph
, lowest_node
, i
, false);
1437 unite (lowest_node
, i
);
1438 graph
->indirect_cycles
[i
- FIRST_REF_NODE
] = lowest_node
;
1442 bitmap_set_bit (si
->deleted
, n
);
1445 si
->scc_stack
.safe_push (n
);
1448 /* Unify node FROM into node TO, updating the changed count if
1449 necessary when UPDATE_CHANGED is true. */
1452 unify_nodes (constraint_graph_t graph
, unsigned int to
, unsigned int from
,
1453 bool update_changed
)
1455 gcc_checking_assert (to
!= from
&& find (to
) == to
);
1457 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1458 fprintf (dump_file
, "Unifying %s to %s\n",
1459 get_varinfo (from
)->name
,
1460 get_varinfo (to
)->name
);
1463 stats
.unified_vars_dynamic
++;
1465 stats
.unified_vars_static
++;
1467 merge_graph_nodes (graph
, to
, from
);
1468 merge_node_constraints (graph
, to
, from
);
1470 /* Mark TO as changed if FROM was changed. If TO was already marked
1471 as changed, decrease the changed count. */
1474 && bitmap_clear_bit (changed
, from
))
1475 bitmap_set_bit (changed
, to
);
1476 varinfo_t fromvi
= get_varinfo (from
);
1477 if (fromvi
->solution
)
1479 /* If the solution changes because of the merging, we need to mark
1480 the variable as changed. */
1481 varinfo_t tovi
= get_varinfo (to
);
1482 if (bitmap_ior_into (tovi
->solution
, fromvi
->solution
))
1485 bitmap_set_bit (changed
, to
);
1488 BITMAP_FREE (fromvi
->solution
);
1489 if (fromvi
->oldsolution
)
1490 BITMAP_FREE (fromvi
->oldsolution
);
1492 if (stats
.iterations
> 0
1493 && tovi
->oldsolution
)
1494 BITMAP_FREE (tovi
->oldsolution
);
1496 if (graph
->succs
[to
])
1497 bitmap_clear_bit (graph
->succs
[to
], to
);
1500 /* Information needed to compute the topological ordering of a graph. */
1504 /* sbitmap of visited nodes. */
1506 /* Array that stores the topological order of the graph, *in
1508 vec
<unsigned> topo_order
;
1512 /* Initialize and return a topological info structure. */
1514 static struct topo_info
*
1515 init_topo_info (void)
1517 size_t size
= graph
->size
;
1518 struct topo_info
*ti
= XNEW (struct topo_info
);
1519 ti
->visited
= sbitmap_alloc (size
);
1520 bitmap_clear (ti
->visited
);
1521 ti
->topo_order
.create (1);
1526 /* Free the topological sort info pointed to by TI. */
1529 free_topo_info (struct topo_info
*ti
)
1531 sbitmap_free (ti
->visited
);
1532 ti
->topo_order
.release ();
1536 /* Visit the graph in topological order, and store the order in the
1537 topo_info structure. */
1540 topo_visit (constraint_graph_t graph
, struct topo_info
*ti
,
1546 bitmap_set_bit (ti
->visited
, n
);
1548 if (graph
->succs
[n
])
1549 EXECUTE_IF_SET_IN_BITMAP (graph
->succs
[n
], 0, j
, bi
)
1551 if (!bitmap_bit_p (ti
->visited
, j
))
1552 topo_visit (graph
, ti
, j
);
1555 ti
->topo_order
.safe_push (n
);
1558 /* Process a constraint C that represents x = *(y + off), using DELTA as the
1559 starting solution for y. */
1562 do_sd_constraint (constraint_graph_t graph
, constraint_t c
,
1565 unsigned int lhs
= c
->lhs
.var
;
1567 bitmap sol
= get_varinfo (lhs
)->solution
;
1570 HOST_WIDE_INT roffset
= c
->rhs
.offset
;
1572 /* Our IL does not allow this. */
1573 gcc_checking_assert (c
->lhs
.offset
== 0);
1575 /* If the solution of Y contains anything it is good enough to transfer
1577 if (bitmap_bit_p (delta
, anything_id
))
1579 flag
|= bitmap_set_bit (sol
, anything_id
);
1583 /* If we do not know at with offset the rhs is dereferenced compute
1584 the reachability set of DELTA, conservatively assuming it is
1585 dereferenced at all valid offsets. */
1586 if (roffset
== UNKNOWN_OFFSET
)
1588 solution_set_expand (delta
);
1589 /* No further offset processing is necessary. */
1593 /* For each variable j in delta (Sol(y)), add
1594 an edge in the graph from j to x, and union Sol(j) into Sol(x). */
1595 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, j
, bi
)
1597 varinfo_t v
= get_varinfo (j
);
1598 HOST_WIDE_INT fieldoffset
= v
->offset
+ roffset
;
1602 fieldoffset
= v
->offset
;
1603 else if (roffset
!= 0)
1604 v
= first_vi_for_offset (v
, fieldoffset
);
1605 /* If the access is outside of the variable we can ignore it. */
1613 /* Adding edges from the special vars is pointless.
1614 They don't have sets that can change. */
1615 if (get_varinfo (t
)->is_special_var
)
1616 flag
|= bitmap_ior_into (sol
, get_varinfo (t
)->solution
);
1617 /* Merging the solution from ESCAPED needlessly increases
1618 the set. Use ESCAPED as representative instead. */
1619 else if (v
->id
== escaped_id
)
1620 flag
|= bitmap_set_bit (sol
, escaped_id
);
1621 else if (v
->may_have_pointers
1622 && add_graph_edge (graph
, lhs
, t
))
1623 flag
|= bitmap_ior_into (sol
, get_varinfo (t
)->solution
);
1625 /* If the variable is not exactly at the requested offset
1626 we have to include the next one. */
1627 if (v
->offset
== (unsigned HOST_WIDE_INT
)fieldoffset
1632 fieldoffset
= v
->offset
;
1638 /* If the LHS solution changed, mark the var as changed. */
1641 get_varinfo (lhs
)->solution
= sol
;
1642 bitmap_set_bit (changed
, lhs
);
1646 /* Process a constraint C that represents *(x + off) = y using DELTA
1647 as the starting solution for x. */
1650 do_ds_constraint (constraint_t c
, bitmap delta
)
1652 unsigned int rhs
= c
->rhs
.var
;
1653 bitmap sol
= get_varinfo (rhs
)->solution
;
1656 HOST_WIDE_INT loff
= c
->lhs
.offset
;
1657 bool escaped_p
= false;
1659 /* Our IL does not allow this. */
1660 gcc_checking_assert (c
->rhs
.offset
== 0);
1662 /* If the solution of y contains ANYTHING simply use the ANYTHING
1663 solution. This avoids needlessly increasing the points-to sets. */
1664 if (bitmap_bit_p (sol
, anything_id
))
1665 sol
= get_varinfo (find (anything_id
))->solution
;
1667 /* If the solution for x contains ANYTHING we have to merge the
1668 solution of y into all pointer variables which we do via
1670 if (bitmap_bit_p (delta
, anything_id
))
1672 unsigned t
= find (storedanything_id
);
1673 if (add_graph_edge (graph
, t
, rhs
))
1675 if (bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1676 bitmap_set_bit (changed
, t
);
1681 /* If we do not know at with offset the rhs is dereferenced compute
1682 the reachability set of DELTA, conservatively assuming it is
1683 dereferenced at all valid offsets. */
1684 if (loff
== UNKNOWN_OFFSET
)
1686 solution_set_expand (delta
);
1690 /* For each member j of delta (Sol(x)), add an edge from y to j and
1691 union Sol(y) into Sol(j) */
1692 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, j
, bi
)
1694 varinfo_t v
= get_varinfo (j
);
1696 HOST_WIDE_INT fieldoffset
= v
->offset
+ loff
;
1699 fieldoffset
= v
->offset
;
1701 v
= first_vi_for_offset (v
, fieldoffset
);
1702 /* If the access is outside of the variable we can ignore it. */
1708 if (v
->may_have_pointers
)
1710 /* If v is a global variable then this is an escape point. */
1711 if (v
->is_global_var
1714 t
= find (escaped_id
);
1715 if (add_graph_edge (graph
, t
, rhs
)
1716 && bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1717 bitmap_set_bit (changed
, t
);
1718 /* Enough to let rhs escape once. */
1722 if (v
->is_special_var
)
1726 if (add_graph_edge (graph
, t
, rhs
)
1727 && bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1728 bitmap_set_bit (changed
, t
);
1731 /* If the variable is not exactly at the requested offset
1732 we have to include the next one. */
1733 if (v
->offset
== (unsigned HOST_WIDE_INT
)fieldoffset
1738 fieldoffset
= v
->offset
;
1744 /* Handle a non-simple (simple meaning requires no iteration),
1745 constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
1748 do_complex_constraint (constraint_graph_t graph
, constraint_t c
, bitmap delta
)
1750 if (c
->lhs
.type
== DEREF
)
1752 if (c
->rhs
.type
== ADDRESSOF
)
1759 do_ds_constraint (c
, delta
);
1762 else if (c
->rhs
.type
== DEREF
)
1765 if (!(get_varinfo (c
->lhs
.var
)->is_special_var
))
1766 do_sd_constraint (graph
, c
, delta
);
1774 gcc_checking_assert (c
->rhs
.type
== SCALAR
&& c
->lhs
.type
== SCALAR
);
1775 solution
= get_varinfo (c
->rhs
.var
)->solution
;
1776 tmp
= get_varinfo (c
->lhs
.var
)->solution
;
1778 flag
= set_union_with_increment (tmp
, solution
, c
->rhs
.offset
);
1781 bitmap_set_bit (changed
, c
->lhs
.var
);
1785 /* Initialize and return a new SCC info structure. */
1787 static struct scc_info
*
1788 init_scc_info (size_t size
)
1790 struct scc_info
*si
= XNEW (struct scc_info
);
1793 si
->current_index
= 0;
1794 si
->visited
= sbitmap_alloc (size
);
1795 bitmap_clear (si
->visited
);
1796 si
->deleted
= sbitmap_alloc (size
);
1797 bitmap_clear (si
->deleted
);
1798 si
->node_mapping
= XNEWVEC (unsigned int, size
);
1799 si
->dfs
= XCNEWVEC (unsigned int, size
);
1801 for (i
= 0; i
< size
; i
++)
1802 si
->node_mapping
[i
] = i
;
1804 si
->scc_stack
.create (1);
1808 /* Free an SCC info structure pointed to by SI */
1811 free_scc_info (struct scc_info
*si
)
1813 sbitmap_free (si
->visited
);
1814 sbitmap_free (si
->deleted
);
1815 free (si
->node_mapping
);
1817 si
->scc_stack
.release ();
1822 /* Find indirect cycles in GRAPH that occur, using strongly connected
1823 components, and note them in the indirect cycles map.
1825 This technique comes from Ben Hardekopf and Calvin Lin,
1826 "It Pays to be Lazy: Fast and Accurate Pointer Analysis for Millions of
1827 Lines of Code", submitted to PLDI 2007. */
1830 find_indirect_cycles (constraint_graph_t graph
)
1833 unsigned int size
= graph
->size
;
1834 struct scc_info
*si
= init_scc_info (size
);
1836 for (i
= 0; i
< MIN (LAST_REF_NODE
, size
); i
++ )
1837 if (!bitmap_bit_p (si
->visited
, i
) && find (i
) == i
)
1838 scc_visit (graph
, si
, i
);
1843 /* Compute a topological ordering for GRAPH, and store the result in the
1844 topo_info structure TI. */
1847 compute_topo_order (constraint_graph_t graph
,
1848 struct topo_info
*ti
)
1851 unsigned int size
= graph
->size
;
1853 for (i
= 0; i
!= size
; ++i
)
1854 if (!bitmap_bit_p (ti
->visited
, i
) && find (i
) == i
)
1855 topo_visit (graph
, ti
, i
);
1858 /* Structure used to for hash value numbering of pointer equivalence
1861 typedef struct equiv_class_label
1864 unsigned int equivalence_class
;
1866 } *equiv_class_label_t
;
1867 typedef const struct equiv_class_label
*const_equiv_class_label_t
;
1869 /* Equiv_class_label hashtable helpers. */
1871 struct equiv_class_hasher
: typed_free_remove
<equiv_class_label
>
1873 typedef equiv_class_label value_type
;
1874 typedef equiv_class_label compare_type
;
1875 static inline hashval_t
hash (const value_type
*);
1876 static inline bool equal (const value_type
*, const compare_type
*);
1879 /* Hash function for a equiv_class_label_t */
1882 equiv_class_hasher::hash (const value_type
*ecl
)
1884 return ecl
->hashcode
;
1887 /* Equality function for two equiv_class_label_t's. */
1890 equiv_class_hasher::equal (const value_type
*eql1
, const compare_type
*eql2
)
1892 return (eql1
->hashcode
== eql2
->hashcode
1893 && bitmap_equal_p (eql1
->labels
, eql2
->labels
));
1896 /* A hashtable for mapping a bitmap of labels->pointer equivalence
1898 static hash_table
<equiv_class_hasher
> pointer_equiv_class_table
;
1900 /* A hashtable for mapping a bitmap of labels->location equivalence
1902 static hash_table
<equiv_class_hasher
> location_equiv_class_table
;
1904 /* Lookup a equivalence class in TABLE by the bitmap of LABELS with
1905 hash HAS it contains. Sets *REF_LABELS to the bitmap LABELS
1906 is equivalent to. */
1908 static equiv_class_label
*
1909 equiv_class_lookup_or_add (hash_table
<equiv_class_hasher
> table
, bitmap labels
)
1911 equiv_class_label
**slot
;
1912 equiv_class_label ecl
;
1914 ecl
.labels
= labels
;
1915 ecl
.hashcode
= bitmap_hash (labels
);
1916 slot
= table
.find_slot_with_hash (&ecl
, ecl
.hashcode
, INSERT
);
1919 *slot
= XNEW (struct equiv_class_label
);
1920 (*slot
)->labels
= labels
;
1921 (*slot
)->hashcode
= ecl
.hashcode
;
1922 (*slot
)->equivalence_class
= 0;
1928 /* Perform offline variable substitution.
1930 This is a worst case quadratic time way of identifying variables
1931 that must have equivalent points-to sets, including those caused by
1932 static cycles, and single entry subgraphs, in the constraint graph.
1934 The technique is described in "Exploiting Pointer and Location
1935 Equivalence to Optimize Pointer Analysis. In the 14th International
1936 Static Analysis Symposium (SAS), August 2007." It is known as the
1937 "HU" algorithm, and is equivalent to value numbering the collapsed
1938 constraint graph including evaluating unions.
1940 The general method of finding equivalence classes is as follows:
1941 Add fake nodes (REF nodes) and edges for *a = b and a = *b constraints.
1942 Initialize all non-REF nodes to be direct nodes.
1943 For each constraint a = a U {b}, we set pts(a) = pts(a) u {fresh
1945 For each constraint containing the dereference, we also do the same
1948 We then compute SCC's in the graph and unify nodes in the same SCC,
1951 For each non-collapsed node x:
1952 Visit all unvisited explicit incoming edges.
1953 Ignoring all non-pointers, set pts(x) = Union of pts(a) for y
1955 Lookup the equivalence class for pts(x).
1956 If we found one, equivalence_class(x) = found class.
1957 Otherwise, equivalence_class(x) = new class, and new_class is
1958 added to the lookup table.
1960 All direct nodes with the same equivalence class can be replaced
1961 with a single representative node.
1962 All unlabeled nodes (label == 0) are not pointers and all edges
1963 involving them can be eliminated.
1964 We perform these optimizations during rewrite_constraints
1966 In addition to pointer equivalence class finding, we also perform
1967 location equivalence class finding. This is the set of variables
1968 that always appear together in points-to sets. We use this to
1969 compress the size of the points-to sets. */
1971 /* Current maximum pointer equivalence class id. */
1972 static int pointer_equiv_class
;
1974 /* Current maximum location equivalence class id. */
1975 static int location_equiv_class
;
1977 /* Recursive routine to find strongly connected components in GRAPH,
1978 and label it's nodes with DFS numbers. */
1981 condense_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
1985 unsigned int my_dfs
;
1987 gcc_checking_assert (si
->node_mapping
[n
] == n
);
1988 bitmap_set_bit (si
->visited
, n
);
1989 si
->dfs
[n
] = si
->current_index
++;
1990 my_dfs
= si
->dfs
[n
];
1992 /* Visit all the successors. */
1993 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[n
], 0, i
, bi
)
1995 unsigned int w
= si
->node_mapping
[i
];
1997 if (bitmap_bit_p (si
->deleted
, w
))
2000 if (!bitmap_bit_p (si
->visited
, w
))
2001 condense_visit (graph
, si
, w
);
2003 unsigned int t
= si
->node_mapping
[w
];
2004 gcc_checking_assert (si
->node_mapping
[n
] == n
);
2005 if (si
->dfs
[t
] < si
->dfs
[n
])
2006 si
->dfs
[n
] = si
->dfs
[t
];
2009 /* Visit all the implicit predecessors. */
2010 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->implicit_preds
[n
], 0, i
, bi
)
2012 unsigned int w
= si
->node_mapping
[i
];
2014 if (bitmap_bit_p (si
->deleted
, w
))
2017 if (!bitmap_bit_p (si
->visited
, w
))
2018 condense_visit (graph
, si
, w
);
2020 unsigned int t
= si
->node_mapping
[w
];
2021 gcc_assert (si
->node_mapping
[n
] == n
);
2022 if (si
->dfs
[t
] < si
->dfs
[n
])
2023 si
->dfs
[n
] = si
->dfs
[t
];
2026 /* See if any components have been identified. */
2027 if (si
->dfs
[n
] == my_dfs
)
2029 while (si
->scc_stack
.length () != 0
2030 && si
->dfs
[si
->scc_stack
.last ()] >= my_dfs
)
2032 unsigned int w
= si
->scc_stack
.pop ();
2033 si
->node_mapping
[w
] = n
;
2035 if (!bitmap_bit_p (graph
->direct_nodes
, w
))
2036 bitmap_clear_bit (graph
->direct_nodes
, n
);
2038 /* Unify our nodes. */
2039 if (graph
->preds
[w
])
2041 if (!graph
->preds
[n
])
2042 graph
->preds
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2043 bitmap_ior_into (graph
->preds
[n
], graph
->preds
[w
]);
2045 if (graph
->implicit_preds
[w
])
2047 if (!graph
->implicit_preds
[n
])
2048 graph
->implicit_preds
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2049 bitmap_ior_into (graph
->implicit_preds
[n
],
2050 graph
->implicit_preds
[w
]);
2052 if (graph
->points_to
[w
])
2054 if (!graph
->points_to
[n
])
2055 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2056 bitmap_ior_into (graph
->points_to
[n
],
2057 graph
->points_to
[w
]);
2060 bitmap_set_bit (si
->deleted
, n
);
2063 si
->scc_stack
.safe_push (n
);
2066 /* Label pointer equivalences.
2068 This performs a value numbering of the constraint graph to
2069 discover which variables will always have the same points-to sets
2070 under the current set of constraints.
2072 The way it value numbers is to store the set of points-to bits
2073 generated by the constraints and graph edges. This is just used as a
2074 hash and equality comparison. The *actual set of points-to bits* is
2075 completely irrelevant, in that we don't care about being able to
2078 The equality values (currently bitmaps) just have to satisfy a few
2079 constraints, the main ones being:
2080 1. The combining operation must be order independent.
2081 2. The end result of a given set of operations must be unique iff the
2082 combination of input values is unique
2086 label_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
2088 unsigned int i
, first_pred
;
2091 bitmap_set_bit (si
->visited
, n
);
2093 /* Label and union our incoming edges's points to sets. */
2095 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[n
], 0, i
, bi
)
2097 unsigned int w
= si
->node_mapping
[i
];
2098 if (!bitmap_bit_p (si
->visited
, w
))
2099 label_visit (graph
, si
, w
);
2101 /* Skip unused edges */
2102 if (w
== n
|| graph
->pointer_label
[w
] == 0)
2105 if (graph
->points_to
[w
])
2107 if (!graph
->points_to
[n
])
2109 if (first_pred
== -1U)
2113 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2114 bitmap_ior (graph
->points_to
[n
],
2115 graph
->points_to
[first_pred
],
2116 graph
->points_to
[w
]);
2120 bitmap_ior_into (graph
->points_to
[n
], graph
->points_to
[w
]);
2124 /* Indirect nodes get fresh variables and a new pointer equiv class. */
2125 if (!bitmap_bit_p (graph
->direct_nodes
, n
))
2127 if (!graph
->points_to
[n
])
2129 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2130 if (first_pred
!= -1U)
2131 bitmap_copy (graph
->points_to
[n
], graph
->points_to
[first_pred
]);
2133 bitmap_set_bit (graph
->points_to
[n
], FIRST_REF_NODE
+ n
);
2134 graph
->pointer_label
[n
] = pointer_equiv_class
++;
2135 equiv_class_label_t ecl
;
2136 ecl
= equiv_class_lookup_or_add (pointer_equiv_class_table
,
2137 graph
->points_to
[n
]);
2138 ecl
->equivalence_class
= graph
->pointer_label
[n
];
2142 /* If there was only a single non-empty predecessor the pointer equiv
2143 class is the same. */
2144 if (!graph
->points_to
[n
])
2146 if (first_pred
!= -1U)
2148 graph
->pointer_label
[n
] = graph
->pointer_label
[first_pred
];
2149 graph
->points_to
[n
] = graph
->points_to
[first_pred
];
2154 if (!bitmap_empty_p (graph
->points_to
[n
]))
2156 equiv_class_label_t ecl
;
2157 ecl
= equiv_class_lookup_or_add (pointer_equiv_class_table
,
2158 graph
->points_to
[n
]);
2159 if (ecl
->equivalence_class
== 0)
2160 ecl
->equivalence_class
= pointer_equiv_class
++;
2163 BITMAP_FREE (graph
->points_to
[n
]);
2164 graph
->points_to
[n
] = ecl
->labels
;
2166 graph
->pointer_label
[n
] = ecl
->equivalence_class
;
2170 /* Print the pred graph in dot format. */
2173 dump_pred_graph (struct scc_info
*si
, FILE *file
)
2177 /* Only print the graph if it has already been initialized: */
2181 /* Prints the header of the dot file: */
2182 fprintf (file
, "strict digraph {\n");
2183 fprintf (file
, " node [\n shape = box\n ]\n");
2184 fprintf (file
, " edge [\n fontsize = \"12\"\n ]\n");
2185 fprintf (file
, "\n // List of nodes and complex constraints in "
2186 "the constraint graph:\n");
2188 /* The next lines print the nodes in the graph together with the
2189 complex constraints attached to them. */
2190 for (i
= 1; i
< graph
->size
; i
++)
2192 if (i
== FIRST_REF_NODE
)
2194 if (si
->node_mapping
[i
] != i
)
2196 if (i
< FIRST_REF_NODE
)
2197 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
2199 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
2200 if (graph
->points_to
[i
]
2201 && !bitmap_empty_p (graph
->points_to
[i
]))
2203 fprintf (file
, "[label=\"%s = {", get_varinfo (i
)->name
);
2206 EXECUTE_IF_SET_IN_BITMAP (graph
->points_to
[i
], 0, j
, bi
)
2207 fprintf (file
, " %d", j
);
2208 fprintf (file
, " }\"]");
2210 fprintf (file
, ";\n");
2213 /* Go over the edges. */
2214 fprintf (file
, "\n // Edges in the constraint graph:\n");
2215 for (i
= 1; i
< graph
->size
; i
++)
2219 if (si
->node_mapping
[i
] != i
)
2221 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[i
], 0, j
, bi
)
2223 unsigned from
= si
->node_mapping
[j
];
2224 if (from
< FIRST_REF_NODE
)
2225 fprintf (file
, "\"%s\"", get_varinfo (from
)->name
);
2227 fprintf (file
, "\"*%s\"", get_varinfo (from
- FIRST_REF_NODE
)->name
);
2228 fprintf (file
, " -> ");
2229 if (i
< FIRST_REF_NODE
)
2230 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
2232 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
2233 fprintf (file
, ";\n");
2237 /* Prints the tail of the dot file. */
2238 fprintf (file
, "}\n");
2241 /* Perform offline variable substitution, discovering equivalence
2242 classes, and eliminating non-pointer variables. */
2244 static struct scc_info
*
2245 perform_var_substitution (constraint_graph_t graph
)
2248 unsigned int size
= graph
->size
;
2249 struct scc_info
*si
= init_scc_info (size
);
2251 bitmap_obstack_initialize (&iteration_obstack
);
2252 pointer_equiv_class_table
.create (511);
2253 location_equiv_class_table
.create (511);
2254 pointer_equiv_class
= 1;
2255 location_equiv_class
= 1;
2257 /* Condense the nodes, which means to find SCC's, count incoming
2258 predecessors, and unite nodes in SCC's. */
2259 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2260 if (!bitmap_bit_p (si
->visited
, si
->node_mapping
[i
]))
2261 condense_visit (graph
, si
, si
->node_mapping
[i
]);
2263 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
2265 fprintf (dump_file
, "\n\n// The constraint graph before var-substitution "
2266 "in dot format:\n");
2267 dump_pred_graph (si
, dump_file
);
2268 fprintf (dump_file
, "\n\n");
2271 bitmap_clear (si
->visited
);
2272 /* Actually the label the nodes for pointer equivalences */
2273 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2274 if (!bitmap_bit_p (si
->visited
, si
->node_mapping
[i
]))
2275 label_visit (graph
, si
, si
->node_mapping
[i
]);
2277 /* Calculate location equivalence labels. */
2278 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2284 if (!graph
->pointed_by
[i
])
2286 pointed_by
= BITMAP_ALLOC (&iteration_obstack
);
2288 /* Translate the pointed-by mapping for pointer equivalence
2290 EXECUTE_IF_SET_IN_BITMAP (graph
->pointed_by
[i
], 0, j
, bi
)
2292 bitmap_set_bit (pointed_by
,
2293 graph
->pointer_label
[si
->node_mapping
[j
]]);
2295 /* The original pointed_by is now dead. */
2296 BITMAP_FREE (graph
->pointed_by
[i
]);
2298 /* Look up the location equivalence label if one exists, or make
2300 equiv_class_label_t ecl
;
2301 ecl
= equiv_class_lookup_or_add (location_equiv_class_table
, pointed_by
);
2302 if (ecl
->equivalence_class
== 0)
2303 ecl
->equivalence_class
= location_equiv_class
++;
2306 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2307 fprintf (dump_file
, "Found location equivalence for node %s\n",
2308 get_varinfo (i
)->name
);
2309 BITMAP_FREE (pointed_by
);
2311 graph
->loc_label
[i
] = ecl
->equivalence_class
;
2315 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2316 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2318 unsigned j
= si
->node_mapping
[i
];
2321 fprintf (dump_file
, "%s node id %d ",
2322 bitmap_bit_p (graph
->direct_nodes
, i
)
2323 ? "Direct" : "Indirect", i
);
2324 if (i
< FIRST_REF_NODE
)
2325 fprintf (dump_file
, "\"%s\"", get_varinfo (i
)->name
);
2327 fprintf (dump_file
, "\"*%s\"",
2328 get_varinfo (i
- FIRST_REF_NODE
)->name
);
2329 fprintf (dump_file
, " mapped to SCC leader node id %d ", j
);
2330 if (j
< FIRST_REF_NODE
)
2331 fprintf (dump_file
, "\"%s\"\n", get_varinfo (j
)->name
);
2333 fprintf (dump_file
, "\"*%s\"\n",
2334 get_varinfo (j
- FIRST_REF_NODE
)->name
);
2339 "Equivalence classes for %s node id %d ",
2340 bitmap_bit_p (graph
->direct_nodes
, i
)
2341 ? "direct" : "indirect", i
);
2342 if (i
< FIRST_REF_NODE
)
2343 fprintf (dump_file
, "\"%s\"", get_varinfo (i
)->name
);
2345 fprintf (dump_file
, "\"*%s\"",
2346 get_varinfo (i
- FIRST_REF_NODE
)->name
);
2348 ": pointer %d, location %d\n",
2349 graph
->pointer_label
[i
], graph
->loc_label
[i
]);
2353 /* Quickly eliminate our non-pointer variables. */
2355 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2357 unsigned int node
= si
->node_mapping
[i
];
2359 if (graph
->pointer_label
[node
] == 0)
2361 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2363 "%s is a non-pointer variable, eliminating edges.\n",
2364 get_varinfo (node
)->name
);
2365 stats
.nonpointer_vars
++;
2366 clear_edges_for_node (graph
, node
);
2373 /* Free information that was only necessary for variable
2377 free_var_substitution_info (struct scc_info
*si
)
2380 free (graph
->pointer_label
);
2381 free (graph
->loc_label
);
2382 free (graph
->pointed_by
);
2383 free (graph
->points_to
);
2384 free (graph
->eq_rep
);
2385 sbitmap_free (graph
->direct_nodes
);
2386 pointer_equiv_class_table
.dispose ();
2387 location_equiv_class_table
.dispose ();
2388 bitmap_obstack_release (&iteration_obstack
);
2391 /* Return an existing node that is equivalent to NODE, which has
2392 equivalence class LABEL, if one exists. Return NODE otherwise. */
2395 find_equivalent_node (constraint_graph_t graph
,
2396 unsigned int node
, unsigned int label
)
2398 /* If the address version of this variable is unused, we can
2399 substitute it for anything else with the same label.
2400 Otherwise, we know the pointers are equivalent, but not the
2401 locations, and we can unite them later. */
2403 if (!bitmap_bit_p (graph
->address_taken
, node
))
2405 gcc_checking_assert (label
< graph
->size
);
2407 if (graph
->eq_rep
[label
] != -1)
2409 /* Unify the two variables since we know they are equivalent. */
2410 if (unite (graph
->eq_rep
[label
], node
))
2411 unify_nodes (graph
, graph
->eq_rep
[label
], node
, false);
2412 return graph
->eq_rep
[label
];
2416 graph
->eq_rep
[label
] = node
;
2417 graph
->pe_rep
[label
] = node
;
2422 gcc_checking_assert (label
< graph
->size
);
2423 graph
->pe
[node
] = label
;
2424 if (graph
->pe_rep
[label
] == -1)
2425 graph
->pe_rep
[label
] = node
;
2431 /* Unite pointer equivalent but not location equivalent nodes in
2432 GRAPH. This may only be performed once variable substitution is
2436 unite_pointer_equivalences (constraint_graph_t graph
)
2440 /* Go through the pointer equivalences and unite them to their
2441 representative, if they aren't already. */
2442 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2444 unsigned int label
= graph
->pe
[i
];
2447 int label_rep
= graph
->pe_rep
[label
];
2449 if (label_rep
== -1)
2452 label_rep
= find (label_rep
);
2453 if (label_rep
>= 0 && unite (label_rep
, find (i
)))
2454 unify_nodes (graph
, label_rep
, i
, false);
2459 /* Move complex constraints to the GRAPH nodes they belong to. */
2462 move_complex_constraints (constraint_graph_t graph
)
2467 FOR_EACH_VEC_ELT (constraints
, i
, c
)
2471 struct constraint_expr lhs
= c
->lhs
;
2472 struct constraint_expr rhs
= c
->rhs
;
2474 if (lhs
.type
== DEREF
)
2476 insert_into_complex (graph
, lhs
.var
, c
);
2478 else if (rhs
.type
== DEREF
)
2480 if (!(get_varinfo (lhs
.var
)->is_special_var
))
2481 insert_into_complex (graph
, rhs
.var
, c
);
2483 else if (rhs
.type
!= ADDRESSOF
&& lhs
.var
> anything_id
2484 && (lhs
.offset
!= 0 || rhs
.offset
!= 0))
2486 insert_into_complex (graph
, rhs
.var
, c
);
2493 /* Optimize and rewrite complex constraints while performing
2494 collapsing of equivalent nodes. SI is the SCC_INFO that is the
2495 result of perform_variable_substitution. */
2498 rewrite_constraints (constraint_graph_t graph
,
2499 struct scc_info
*si
)
2504 #ifdef ENABLE_CHECKING
2505 for (unsigned int j
= 0; j
< graph
->size
; j
++)
2506 gcc_assert (find (j
) == j
);
2509 FOR_EACH_VEC_ELT (constraints
, i
, c
)
2511 struct constraint_expr lhs
= c
->lhs
;
2512 struct constraint_expr rhs
= c
->rhs
;
2513 unsigned int lhsvar
= find (lhs
.var
);
2514 unsigned int rhsvar
= find (rhs
.var
);
2515 unsigned int lhsnode
, rhsnode
;
2516 unsigned int lhslabel
, rhslabel
;
2518 lhsnode
= si
->node_mapping
[lhsvar
];
2519 rhsnode
= si
->node_mapping
[rhsvar
];
2520 lhslabel
= graph
->pointer_label
[lhsnode
];
2521 rhslabel
= graph
->pointer_label
[rhsnode
];
2523 /* See if it is really a non-pointer variable, and if so, ignore
2527 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2530 fprintf (dump_file
, "%s is a non-pointer variable,"
2531 "ignoring constraint:",
2532 get_varinfo (lhs
.var
)->name
);
2533 dump_constraint (dump_file
, c
);
2534 fprintf (dump_file
, "\n");
2536 constraints
[i
] = NULL
;
2542 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2545 fprintf (dump_file
, "%s is a non-pointer variable,"
2546 "ignoring constraint:",
2547 get_varinfo (rhs
.var
)->name
);
2548 dump_constraint (dump_file
, c
);
2549 fprintf (dump_file
, "\n");
2551 constraints
[i
] = NULL
;
2555 lhsvar
= find_equivalent_node (graph
, lhsvar
, lhslabel
);
2556 rhsvar
= find_equivalent_node (graph
, rhsvar
, rhslabel
);
2557 c
->lhs
.var
= lhsvar
;
2558 c
->rhs
.var
= rhsvar
;
2562 /* Eliminate indirect cycles involving NODE. Return true if NODE was
2563 part of an SCC, false otherwise. */
2566 eliminate_indirect_cycles (unsigned int node
)
2568 if (graph
->indirect_cycles
[node
] != -1
2569 && !bitmap_empty_p (get_varinfo (node
)->solution
))
2572 vec
<unsigned> queue
= vNULL
;
2574 unsigned int to
= find (graph
->indirect_cycles
[node
]);
2577 /* We can't touch the solution set and call unify_nodes
2578 at the same time, because unify_nodes is going to do
2579 bitmap unions into it. */
2581 EXECUTE_IF_SET_IN_BITMAP (get_varinfo (node
)->solution
, 0, i
, bi
)
2583 if (find (i
) == i
&& i
!= to
)
2586 queue
.safe_push (i
);
2591 queue
.iterate (queuepos
, &i
);
2594 unify_nodes (graph
, to
, i
, true);
2602 /* Solve the constraint graph GRAPH using our worklist solver.
2603 This is based on the PW* family of solvers from the "Efficient Field
2604 Sensitive Pointer Analysis for C" paper.
2605 It works by iterating over all the graph nodes, processing the complex
2606 constraints and propagating the copy constraints, until everything stops
2607 changed. This corresponds to steps 6-8 in the solving list given above. */
2610 solve_graph (constraint_graph_t graph
)
2612 unsigned int size
= graph
->size
;
2616 changed
= BITMAP_ALLOC (NULL
);
2618 /* Mark all initial non-collapsed nodes as changed. */
2619 for (i
= 1; i
< size
; i
++)
2621 varinfo_t ivi
= get_varinfo (i
);
2622 if (find (i
) == i
&& !bitmap_empty_p (ivi
->solution
)
2623 && ((graph
->succs
[i
] && !bitmap_empty_p (graph
->succs
[i
]))
2624 || graph
->complex[i
].length () > 0))
2625 bitmap_set_bit (changed
, i
);
2628 /* Allocate a bitmap to be used to store the changed bits. */
2629 pts
= BITMAP_ALLOC (&pta_obstack
);
2631 while (!bitmap_empty_p (changed
))
2634 struct topo_info
*ti
= init_topo_info ();
2637 bitmap_obstack_initialize (&iteration_obstack
);
2639 compute_topo_order (graph
, ti
);
2641 while (ti
->topo_order
.length () != 0)
2644 i
= ti
->topo_order
.pop ();
2646 /* If this variable is not a representative, skip it. */
2650 /* In certain indirect cycle cases, we may merge this
2651 variable to another. */
2652 if (eliminate_indirect_cycles (i
) && find (i
) != i
)
2655 /* If the node has changed, we need to process the
2656 complex constraints and outgoing edges again. */
2657 if (bitmap_clear_bit (changed
, i
))
2662 vec
<constraint_t
> complex = graph
->complex[i
];
2663 varinfo_t vi
= get_varinfo (i
);
2664 bool solution_empty
;
2666 /* Compute the changed set of solution bits. If anything
2667 is in the solution just propagate that. */
2668 if (bitmap_bit_p (vi
->solution
, anything_id
))
2670 /* If anything is also in the old solution there is
2672 ??? But we shouldn't ended up with "changed" set ... */
2674 && bitmap_bit_p (vi
->oldsolution
, anything_id
))
2676 bitmap_copy (pts
, get_varinfo (find (anything_id
))->solution
);
2678 else if (vi
->oldsolution
)
2679 bitmap_and_compl (pts
, vi
->solution
, vi
->oldsolution
);
2681 bitmap_copy (pts
, vi
->solution
);
2683 if (bitmap_empty_p (pts
))
2686 if (vi
->oldsolution
)
2687 bitmap_ior_into (vi
->oldsolution
, pts
);
2690 vi
->oldsolution
= BITMAP_ALLOC (&oldpta_obstack
);
2691 bitmap_copy (vi
->oldsolution
, pts
);
2694 solution
= vi
->solution
;
2695 solution_empty
= bitmap_empty_p (solution
);
2697 /* Process the complex constraints */
2698 FOR_EACH_VEC_ELT (complex, j
, c
)
2700 /* XXX: This is going to unsort the constraints in
2701 some cases, which will occasionally add duplicate
2702 constraints during unification. This does not
2703 affect correctness. */
2704 c
->lhs
.var
= find (c
->lhs
.var
);
2705 c
->rhs
.var
= find (c
->rhs
.var
);
2707 /* The only complex constraint that can change our
2708 solution to non-empty, given an empty solution,
2709 is a constraint where the lhs side is receiving
2710 some set from elsewhere. */
2711 if (!solution_empty
|| c
->lhs
.type
!= DEREF
)
2712 do_complex_constraint (graph
, c
, pts
);
2715 solution_empty
= bitmap_empty_p (solution
);
2717 if (!solution_empty
)
2720 unsigned eff_escaped_id
= find (escaped_id
);
2722 /* Propagate solution to all successors. */
2723 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[i
],
2729 unsigned int to
= find (j
);
2730 tmp
= get_varinfo (to
)->solution
;
2733 /* Don't try to propagate to ourselves. */
2737 /* If we propagate from ESCAPED use ESCAPED as
2739 if (i
== eff_escaped_id
)
2740 flag
= bitmap_set_bit (tmp
, escaped_id
);
2742 flag
= bitmap_ior_into (tmp
, pts
);
2745 bitmap_set_bit (changed
, to
);
2750 free_topo_info (ti
);
2751 bitmap_obstack_release (&iteration_obstack
);
2755 BITMAP_FREE (changed
);
2756 bitmap_obstack_release (&oldpta_obstack
);
2759 /* Map from trees to variable infos. */
2760 static struct pointer_map_t
*vi_for_tree
;
2763 /* Insert ID as the variable id for tree T in the vi_for_tree map. */
2766 insert_vi_for_tree (tree t
, varinfo_t vi
)
2768 void **slot
= pointer_map_insert (vi_for_tree
, t
);
2770 gcc_assert (*slot
== NULL
);
2774 /* Find the variable info for tree T in VI_FOR_TREE. If T does not
2775 exist in the map, return NULL, otherwise, return the varinfo we found. */
2778 lookup_vi_for_tree (tree t
)
2780 void **slot
= pointer_map_contains (vi_for_tree
, t
);
2784 return (varinfo_t
) *slot
;
2787 /* Return a printable name for DECL */
2790 alias_get_name (tree decl
)
2792 const char *res
= NULL
;
2794 int num_printed
= 0;
2799 if (TREE_CODE (decl
) == SSA_NAME
)
2801 res
= get_name (decl
);
2803 num_printed
= asprintf (&temp
, "%s_%u", res
, SSA_NAME_VERSION (decl
));
2805 num_printed
= asprintf (&temp
, "_%u", SSA_NAME_VERSION (decl
));
2806 if (num_printed
> 0)
2808 res
= ggc_strdup (temp
);
2812 else if (DECL_P (decl
))
2814 if (DECL_ASSEMBLER_NAME_SET_P (decl
))
2815 res
= IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl
));
2818 res
= get_name (decl
);
2821 num_printed
= asprintf (&temp
, "D.%u", DECL_UID (decl
));
2822 if (num_printed
> 0)
2824 res
= ggc_strdup (temp
);
2836 /* Find the variable id for tree T in the map.
2837 If T doesn't exist in the map, create an entry for it and return it. */
2840 get_vi_for_tree (tree t
)
2842 void **slot
= pointer_map_contains (vi_for_tree
, t
);
2844 return get_varinfo (create_variable_info_for (t
, alias_get_name (t
)));
2846 return (varinfo_t
) *slot
;
2849 /* Get a scalar constraint expression for a new temporary variable. */
2851 static struct constraint_expr
2852 new_scalar_tmp_constraint_exp (const char *name
)
2854 struct constraint_expr tmp
;
2857 vi
= new_var_info (NULL_TREE
, name
);
2861 vi
->is_full_var
= 1;
2870 /* Get a constraint expression vector from an SSA_VAR_P node.
2871 If address_p is true, the result will be taken its address of. */
2874 get_constraint_for_ssa_var (tree t
, vec
<ce_s
> *results
, bool address_p
)
2876 struct constraint_expr cexpr
;
2879 /* We allow FUNCTION_DECLs here even though it doesn't make much sense. */
2880 gcc_assert (TREE_CODE (t
) == SSA_NAME
|| DECL_P (t
));
2882 /* For parameters, get at the points-to set for the actual parm
2884 if (TREE_CODE (t
) == SSA_NAME
2885 && SSA_NAME_IS_DEFAULT_DEF (t
)
2886 && (TREE_CODE (SSA_NAME_VAR (t
)) == PARM_DECL
2887 || TREE_CODE (SSA_NAME_VAR (t
)) == RESULT_DECL
))
2889 get_constraint_for_ssa_var (SSA_NAME_VAR (t
), results
, address_p
);
2893 /* For global variables resort to the alias target. */
2894 if (TREE_CODE (t
) == VAR_DECL
2895 && (TREE_STATIC (t
) || DECL_EXTERNAL (t
)))
2897 struct varpool_node
*node
= varpool_get_node (t
);
2898 if (node
&& node
->alias
&& node
->analyzed
)
2900 node
= varpool_variable_node (node
, NULL
);
2905 vi
= get_vi_for_tree (t
);
2907 cexpr
.type
= SCALAR
;
2909 /* If we determine the result is "anything", and we know this is readonly,
2910 say it points to readonly memory instead. */
2911 if (cexpr
.var
== anything_id
&& TREE_READONLY (t
))
2914 cexpr
.type
= ADDRESSOF
;
2915 cexpr
.var
= readonly_id
;
2918 /* If we are not taking the address of the constraint expr, add all
2919 sub-fiels of the variable as well. */
2921 && !vi
->is_full_var
)
2923 for (; vi
; vi
= vi_next (vi
))
2926 results
->safe_push (cexpr
);
2931 results
->safe_push (cexpr
);
2934 /* Process constraint T, performing various simplifications and then
2935 adding it to our list of overall constraints. */
2938 process_constraint (constraint_t t
)
2940 struct constraint_expr rhs
= t
->rhs
;
2941 struct constraint_expr lhs
= t
->lhs
;
2943 gcc_assert (rhs
.var
< varmap
.length ());
2944 gcc_assert (lhs
.var
< varmap
.length ());
2946 /* If we didn't get any useful constraint from the lhs we get
2947 &ANYTHING as fallback from get_constraint_for. Deal with
2948 it here by turning it into *ANYTHING. */
2949 if (lhs
.type
== ADDRESSOF
2950 && lhs
.var
== anything_id
)
2953 /* ADDRESSOF on the lhs is invalid. */
2954 gcc_assert (lhs
.type
!= ADDRESSOF
);
2956 /* We shouldn't add constraints from things that cannot have pointers.
2957 It's not completely trivial to avoid in the callers, so do it here. */
2958 if (rhs
.type
!= ADDRESSOF
2959 && !get_varinfo (rhs
.var
)->may_have_pointers
)
2962 /* Likewise adding to the solution of a non-pointer var isn't useful. */
2963 if (!get_varinfo (lhs
.var
)->may_have_pointers
)
2966 /* This can happen in our IR with things like n->a = *p */
2967 if (rhs
.type
== DEREF
&& lhs
.type
== DEREF
&& rhs
.var
!= anything_id
)
2969 /* Split into tmp = *rhs, *lhs = tmp */
2970 struct constraint_expr tmplhs
;
2971 tmplhs
= new_scalar_tmp_constraint_exp ("doubledereftmp");
2972 process_constraint (new_constraint (tmplhs
, rhs
));
2973 process_constraint (new_constraint (lhs
, tmplhs
));
2975 else if (rhs
.type
== ADDRESSOF
&& lhs
.type
== DEREF
)
2977 /* Split into tmp = &rhs, *lhs = tmp */
2978 struct constraint_expr tmplhs
;
2979 tmplhs
= new_scalar_tmp_constraint_exp ("derefaddrtmp");
2980 process_constraint (new_constraint (tmplhs
, rhs
));
2981 process_constraint (new_constraint (lhs
, tmplhs
));
2985 gcc_assert (rhs
.type
!= ADDRESSOF
|| rhs
.offset
== 0);
2986 constraints
.safe_push (t
);
2991 /* Return the position, in bits, of FIELD_DECL from the beginning of its
2994 static HOST_WIDE_INT
2995 bitpos_of_field (const tree fdecl
)
2997 if (!tree_fits_shwi_p (DECL_FIELD_OFFSET (fdecl
))
2998 || !tree_fits_shwi_p (DECL_FIELD_BIT_OFFSET (fdecl
)))
3001 return (tree_to_shwi (DECL_FIELD_OFFSET (fdecl
)) * BITS_PER_UNIT
3002 + tree_to_shwi (DECL_FIELD_BIT_OFFSET (fdecl
)));
3006 /* Get constraint expressions for offsetting PTR by OFFSET. Stores the
3007 resulting constraint expressions in *RESULTS. */
3010 get_constraint_for_ptr_offset (tree ptr
, tree offset
,
3013 struct constraint_expr c
;
3015 HOST_WIDE_INT rhsoffset
;
3017 /* If we do not do field-sensitive PTA adding offsets to pointers
3018 does not change the points-to solution. */
3019 if (!use_field_sensitive
)
3021 get_constraint_for_rhs (ptr
, results
);
3025 /* If the offset is not a non-negative integer constant that fits
3026 in a HOST_WIDE_INT, we have to fall back to a conservative
3027 solution which includes all sub-fields of all pointed-to
3028 variables of ptr. */
3029 if (offset
== NULL_TREE
3030 || TREE_CODE (offset
) != INTEGER_CST
)
3031 rhsoffset
= UNKNOWN_OFFSET
;
3034 /* Sign-extend the offset. */
3035 offset_int soffset
= offset_int::from (offset
, SIGNED
);
3036 if (!wi::fits_shwi_p (soffset
))
3037 rhsoffset
= UNKNOWN_OFFSET
;
3040 /* Make sure the bit-offset also fits. */
3041 HOST_WIDE_INT rhsunitoffset
= soffset
.to_shwi ();
3042 rhsoffset
= rhsunitoffset
* BITS_PER_UNIT
;
3043 if (rhsunitoffset
!= rhsoffset
/ BITS_PER_UNIT
)
3044 rhsoffset
= UNKNOWN_OFFSET
;
3048 get_constraint_for_rhs (ptr
, results
);
3052 /* As we are eventually appending to the solution do not use
3053 vec::iterate here. */
3054 n
= results
->length ();
3055 for (j
= 0; j
< n
; j
++)
3059 curr
= get_varinfo (c
.var
);
3061 if (c
.type
== ADDRESSOF
3062 /* If this varinfo represents a full variable just use it. */
3063 && curr
->is_full_var
)
3065 else if (c
.type
== ADDRESSOF
3066 /* If we do not know the offset add all subfields. */
3067 && rhsoffset
== UNKNOWN_OFFSET
)
3069 varinfo_t temp
= get_varinfo (curr
->head
);
3072 struct constraint_expr c2
;
3074 c2
.type
= ADDRESSOF
;
3076 if (c2
.var
!= c
.var
)
3077 results
->safe_push (c2
);
3078 temp
= vi_next (temp
);
3082 else if (c
.type
== ADDRESSOF
)
3085 unsigned HOST_WIDE_INT offset
= curr
->offset
+ rhsoffset
;
3087 /* Search the sub-field which overlaps with the
3088 pointed-to offset. If the result is outside of the variable
3089 we have to provide a conservative result, as the variable is
3090 still reachable from the resulting pointer (even though it
3091 technically cannot point to anything). The last and first
3092 sub-fields are such conservative results.
3093 ??? If we always had a sub-field for &object + 1 then
3094 we could represent this in a more precise way. */
3096 && curr
->offset
< offset
)
3098 temp
= first_or_preceding_vi_for_offset (curr
, offset
);
3100 /* If the found variable is not exactly at the pointed to
3101 result, we have to include the next variable in the
3102 solution as well. Otherwise two increments by offset / 2
3103 do not result in the same or a conservative superset
3105 if (temp
->offset
!= offset
3108 struct constraint_expr c2
;
3109 c2
.var
= temp
->next
;
3110 c2
.type
= ADDRESSOF
;
3112 results
->safe_push (c2
);
3118 c
.offset
= rhsoffset
;
3125 /* Given a COMPONENT_REF T, return the constraint_expr vector for it.
3126 If address_p is true the result will be taken its address of.
3127 If lhs_p is true then the constraint expression is assumed to be used
3131 get_constraint_for_component_ref (tree t
, vec
<ce_s
> *results
,
3132 bool address_p
, bool lhs_p
)
3135 HOST_WIDE_INT bitsize
= -1;
3136 HOST_WIDE_INT bitmaxsize
= -1;
3137 HOST_WIDE_INT bitpos
;
3140 /* Some people like to do cute things like take the address of
3143 while (handled_component_p (forzero
)
3144 || INDIRECT_REF_P (forzero
)
3145 || TREE_CODE (forzero
) == MEM_REF
)
3146 forzero
= TREE_OPERAND (forzero
, 0);
3148 if (CONSTANT_CLASS_P (forzero
) && integer_zerop (forzero
))
3150 struct constraint_expr temp
;
3153 temp
.var
= integer_id
;
3155 results
->safe_push (temp
);
3159 /* Handle type-punning through unions. If we are extracting a pointer
3160 from a union via a possibly type-punning access that pointer
3161 points to anything, similar to a conversion of an integer to
3167 TREE_CODE (u
) == COMPONENT_REF
|| TREE_CODE (u
) == ARRAY_REF
;
3168 u
= TREE_OPERAND (u
, 0))
3169 if (TREE_CODE (u
) == COMPONENT_REF
3170 && TREE_CODE (TREE_TYPE (TREE_OPERAND (u
, 0))) == UNION_TYPE
)
3172 struct constraint_expr temp
;
3175 temp
.var
= anything_id
;
3176 temp
.type
= ADDRESSOF
;
3177 results
->safe_push (temp
);
3182 t
= get_ref_base_and_extent (t
, &bitpos
, &bitsize
, &bitmaxsize
);
3184 /* Pretend to take the address of the base, we'll take care of
3185 adding the required subset of sub-fields below. */
3186 get_constraint_for_1 (t
, results
, true, lhs_p
);
3187 gcc_assert (results
->length () == 1);
3188 struct constraint_expr
&result
= results
->last ();
3190 if (result
.type
== SCALAR
3191 && get_varinfo (result
.var
)->is_full_var
)
3192 /* For single-field vars do not bother about the offset. */
3194 else if (result
.type
== SCALAR
)
3196 /* In languages like C, you can access one past the end of an
3197 array. You aren't allowed to dereference it, so we can
3198 ignore this constraint. When we handle pointer subtraction,
3199 we may have to do something cute here. */
3201 if ((unsigned HOST_WIDE_INT
)bitpos
< get_varinfo (result
.var
)->fullsize
3204 /* It's also not true that the constraint will actually start at the
3205 right offset, it may start in some padding. We only care about
3206 setting the constraint to the first actual field it touches, so
3208 struct constraint_expr cexpr
= result
;
3212 for (curr
= get_varinfo (cexpr
.var
); curr
; curr
= vi_next (curr
))
3214 if (ranges_overlap_p (curr
->offset
, curr
->size
,
3215 bitpos
, bitmaxsize
))
3217 cexpr
.var
= curr
->id
;
3218 results
->safe_push (cexpr
);
3223 /* If we are going to take the address of this field then
3224 to be able to compute reachability correctly add at least
3225 the last field of the variable. */
3226 if (address_p
&& results
->length () == 0)
3228 curr
= get_varinfo (cexpr
.var
);
3229 while (curr
->next
!= 0)
3230 curr
= vi_next (curr
);
3231 cexpr
.var
= curr
->id
;
3232 results
->safe_push (cexpr
);
3234 else if (results
->length () == 0)
3235 /* Assert that we found *some* field there. The user couldn't be
3236 accessing *only* padding. */
3237 /* Still the user could access one past the end of an array
3238 embedded in a struct resulting in accessing *only* padding. */
3239 /* Or accessing only padding via type-punning to a type
3240 that has a filed just in padding space. */
3242 cexpr
.type
= SCALAR
;
3243 cexpr
.var
= anything_id
;
3245 results
->safe_push (cexpr
);
3248 else if (bitmaxsize
== 0)
3250 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3251 fprintf (dump_file
, "Access to zero-sized part of variable,"
3255 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3256 fprintf (dump_file
, "Access to past the end of variable, ignoring\n");
3258 else if (result
.type
== DEREF
)
3260 /* If we do not know exactly where the access goes say so. Note
3261 that only for non-structure accesses we know that we access
3262 at most one subfiled of any variable. */
3264 || bitsize
!= bitmaxsize
3265 || AGGREGATE_TYPE_P (TREE_TYPE (orig_t
))
3266 || result
.offset
== UNKNOWN_OFFSET
)
3267 result
.offset
= UNKNOWN_OFFSET
;
3269 result
.offset
+= bitpos
;
3271 else if (result
.type
== ADDRESSOF
)
3273 /* We can end up here for component references on a
3274 VIEW_CONVERT_EXPR <>(&foobar). */
3275 result
.type
= SCALAR
;
3276 result
.var
= anything_id
;
3284 /* Dereference the constraint expression CONS, and return the result.
3285 DEREF (ADDRESSOF) = SCALAR
3286 DEREF (SCALAR) = DEREF
3287 DEREF (DEREF) = (temp = DEREF1; result = DEREF(temp))
3288 This is needed so that we can handle dereferencing DEREF constraints. */
3291 do_deref (vec
<ce_s
> *constraints
)
3293 struct constraint_expr
*c
;
3296 FOR_EACH_VEC_ELT (*constraints
, i
, c
)
3298 if (c
->type
== SCALAR
)
3300 else if (c
->type
== ADDRESSOF
)
3302 else if (c
->type
== DEREF
)
3304 struct constraint_expr tmplhs
;
3305 tmplhs
= new_scalar_tmp_constraint_exp ("dereftmp");
3306 process_constraint (new_constraint (tmplhs
, *c
));
3307 c
->var
= tmplhs
.var
;
3314 /* Given a tree T, return the constraint expression for taking the
3318 get_constraint_for_address_of (tree t
, vec
<ce_s
> *results
)
3320 struct constraint_expr
*c
;
3323 get_constraint_for_1 (t
, results
, true, true);
3325 FOR_EACH_VEC_ELT (*results
, i
, c
)
3327 if (c
->type
== DEREF
)
3330 c
->type
= ADDRESSOF
;
3334 /* Given a tree T, return the constraint expression for it. */
3337 get_constraint_for_1 (tree t
, vec
<ce_s
> *results
, bool address_p
,
3340 struct constraint_expr temp
;
3342 /* x = integer is all glommed to a single variable, which doesn't
3343 point to anything by itself. That is, of course, unless it is an
3344 integer constant being treated as a pointer, in which case, we
3345 will return that this is really the addressof anything. This
3346 happens below, since it will fall into the default case. The only
3347 case we know something about an integer treated like a pointer is
3348 when it is the NULL pointer, and then we just say it points to
3351 Do not do that if -fno-delete-null-pointer-checks though, because
3352 in that case *NULL does not fail, so it _should_ alias *anything.
3353 It is not worth adding a new option or renaming the existing one,
3354 since this case is relatively obscure. */
3355 if ((TREE_CODE (t
) == INTEGER_CST
3356 && integer_zerop (t
))
3357 /* The only valid CONSTRUCTORs in gimple with pointer typed
3358 elements are zero-initializer. But in IPA mode we also
3359 process global initializers, so verify at least. */
3360 || (TREE_CODE (t
) == CONSTRUCTOR
3361 && CONSTRUCTOR_NELTS (t
) == 0))
3363 if (flag_delete_null_pointer_checks
)
3364 temp
.var
= nothing_id
;
3366 temp
.var
= nonlocal_id
;
3367 temp
.type
= ADDRESSOF
;
3369 results
->safe_push (temp
);
3373 /* String constants are read-only. */
3374 if (TREE_CODE (t
) == STRING_CST
)
3376 temp
.var
= readonly_id
;
3379 results
->safe_push (temp
);
3383 switch (TREE_CODE_CLASS (TREE_CODE (t
)))
3385 case tcc_expression
:
3387 switch (TREE_CODE (t
))
3390 get_constraint_for_address_of (TREE_OPERAND (t
, 0), results
);
3398 switch (TREE_CODE (t
))
3402 struct constraint_expr cs
;
3404 get_constraint_for_ptr_offset (TREE_OPERAND (t
, 0),
3405 TREE_OPERAND (t
, 1), results
);
3408 /* If we are not taking the address then make sure to process
3409 all subvariables we might access. */
3413 cs
= results
->last ();
3414 if (cs
.type
== DEREF
3415 && type_can_have_subvars (TREE_TYPE (t
)))
3417 /* For dereferences this means we have to defer it
3419 results
->last ().offset
= UNKNOWN_OFFSET
;
3422 if (cs
.type
!= SCALAR
)
3425 vi
= get_varinfo (cs
.var
);
3426 curr
= vi_next (vi
);
3427 if (!vi
->is_full_var
3430 unsigned HOST_WIDE_INT size
;
3431 if (tree_fits_uhwi_p (TYPE_SIZE (TREE_TYPE (t
))))
3432 size
= tree_to_uhwi (TYPE_SIZE (TREE_TYPE (t
)));
3435 for (; curr
; curr
= vi_next (curr
))
3437 if (curr
->offset
- vi
->offset
< size
)
3440 results
->safe_push (cs
);
3449 case ARRAY_RANGE_REF
:
3451 get_constraint_for_component_ref (t
, results
, address_p
, lhs_p
);
3453 case VIEW_CONVERT_EXPR
:
3454 get_constraint_for_1 (TREE_OPERAND (t
, 0), results
, address_p
,
3457 /* We are missing handling for TARGET_MEM_REF here. */
3462 case tcc_exceptional
:
3464 switch (TREE_CODE (t
))
3468 get_constraint_for_ssa_var (t
, results
, address_p
);
3475 vec
<ce_s
> tmp
= vNULL
;
3476 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t
), i
, val
)
3478 struct constraint_expr
*rhsp
;
3480 get_constraint_for_1 (val
, &tmp
, address_p
, lhs_p
);
3481 FOR_EACH_VEC_ELT (tmp
, j
, rhsp
)
3482 results
->safe_push (*rhsp
);
3486 /* We do not know whether the constructor was complete,
3487 so technically we have to add &NOTHING or &ANYTHING
3488 like we do for an empty constructor as well. */
3495 case tcc_declaration
:
3497 get_constraint_for_ssa_var (t
, results
, address_p
);
3502 /* We cannot refer to automatic variables through constants. */
3503 temp
.type
= ADDRESSOF
;
3504 temp
.var
= nonlocal_id
;
3506 results
->safe_push (temp
);
3512 /* The default fallback is a constraint from anything. */
3513 temp
.type
= ADDRESSOF
;
3514 temp
.var
= anything_id
;
3516 results
->safe_push (temp
);
3519 /* Given a gimple tree T, return the constraint expression vector for it. */
3522 get_constraint_for (tree t
, vec
<ce_s
> *results
)
3524 gcc_assert (results
->length () == 0);
3526 get_constraint_for_1 (t
, results
, false, true);
3529 /* Given a gimple tree T, return the constraint expression vector for it
3530 to be used as the rhs of a constraint. */
3533 get_constraint_for_rhs (tree t
, vec
<ce_s
> *results
)
3535 gcc_assert (results
->length () == 0);
3537 get_constraint_for_1 (t
, results
, false, false);
3541 /* Efficiently generates constraints from all entries in *RHSC to all
3542 entries in *LHSC. */
3545 process_all_all_constraints (vec
<ce_s
> lhsc
,
3548 struct constraint_expr
*lhsp
, *rhsp
;
3551 if (lhsc
.length () <= 1 || rhsc
.length () <= 1)
3553 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
3554 FOR_EACH_VEC_ELT (rhsc
, j
, rhsp
)
3555 process_constraint (new_constraint (*lhsp
, *rhsp
));
3559 struct constraint_expr tmp
;
3560 tmp
= new_scalar_tmp_constraint_exp ("allalltmp");
3561 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
3562 process_constraint (new_constraint (tmp
, *rhsp
));
3563 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
3564 process_constraint (new_constraint (*lhsp
, tmp
));
3568 /* Handle aggregate copies by expanding into copies of the respective
3569 fields of the structures. */
3572 do_structure_copy (tree lhsop
, tree rhsop
)
3574 struct constraint_expr
*lhsp
, *rhsp
;
3575 vec
<ce_s
> lhsc
= vNULL
;
3576 vec
<ce_s
> rhsc
= vNULL
;
3579 get_constraint_for (lhsop
, &lhsc
);
3580 get_constraint_for_rhs (rhsop
, &rhsc
);
3583 if (lhsp
->type
== DEREF
3584 || (lhsp
->type
== ADDRESSOF
&& lhsp
->var
== anything_id
)
3585 || rhsp
->type
== DEREF
)
3587 if (lhsp
->type
== DEREF
)
3589 gcc_assert (lhsc
.length () == 1);
3590 lhsp
->offset
= UNKNOWN_OFFSET
;
3592 if (rhsp
->type
== DEREF
)
3594 gcc_assert (rhsc
.length () == 1);
3595 rhsp
->offset
= UNKNOWN_OFFSET
;
3597 process_all_all_constraints (lhsc
, rhsc
);
3599 else if (lhsp
->type
== SCALAR
3600 && (rhsp
->type
== SCALAR
3601 || rhsp
->type
== ADDRESSOF
))
3603 HOST_WIDE_INT lhssize
, lhsmaxsize
, lhsoffset
;
3604 HOST_WIDE_INT rhssize
, rhsmaxsize
, rhsoffset
;
3606 get_ref_base_and_extent (lhsop
, &lhsoffset
, &lhssize
, &lhsmaxsize
);
3607 get_ref_base_and_extent (rhsop
, &rhsoffset
, &rhssize
, &rhsmaxsize
);
3608 for (j
= 0; lhsc
.iterate (j
, &lhsp
);)
3610 varinfo_t lhsv
, rhsv
;
3612 lhsv
= get_varinfo (lhsp
->var
);
3613 rhsv
= get_varinfo (rhsp
->var
);
3614 if (lhsv
->may_have_pointers
3615 && (lhsv
->is_full_var
3616 || rhsv
->is_full_var
3617 || ranges_overlap_p (lhsv
->offset
+ rhsoffset
, lhsv
->size
,
3618 rhsv
->offset
+ lhsoffset
, rhsv
->size
)))
3619 process_constraint (new_constraint (*lhsp
, *rhsp
));
3620 if (!rhsv
->is_full_var
3621 && (lhsv
->is_full_var
3622 || (lhsv
->offset
+ rhsoffset
+ lhsv
->size
3623 > rhsv
->offset
+ lhsoffset
+ rhsv
->size
)))
3626 if (k
>= rhsc
.length ())
3640 /* Create constraints ID = { rhsc }. */
3643 make_constraints_to (unsigned id
, vec
<ce_s
> rhsc
)
3645 struct constraint_expr
*c
;
3646 struct constraint_expr includes
;
3650 includes
.offset
= 0;
3651 includes
.type
= SCALAR
;
3653 FOR_EACH_VEC_ELT (rhsc
, j
, c
)
3654 process_constraint (new_constraint (includes
, *c
));
3657 /* Create a constraint ID = OP. */
3660 make_constraint_to (unsigned id
, tree op
)
3662 vec
<ce_s
> rhsc
= vNULL
;
3663 get_constraint_for_rhs (op
, &rhsc
);
3664 make_constraints_to (id
, rhsc
);
3668 /* Create a constraint ID = &FROM. */
3671 make_constraint_from (varinfo_t vi
, int from
)
3673 struct constraint_expr lhs
, rhs
;
3681 rhs
.type
= ADDRESSOF
;
3682 process_constraint (new_constraint (lhs
, rhs
));
3685 /* Create a constraint ID = FROM. */
3688 make_copy_constraint (varinfo_t vi
, int from
)
3690 struct constraint_expr lhs
, rhs
;
3699 process_constraint (new_constraint (lhs
, rhs
));
3702 /* Make constraints necessary to make OP escape. */
3705 make_escape_constraint (tree op
)
3707 make_constraint_to (escaped_id
, op
);
3710 /* Add constraints to that the solution of VI is transitively closed. */
3713 make_transitive_closure_constraints (varinfo_t vi
)
3715 struct constraint_expr lhs
, rhs
;
3724 process_constraint (new_constraint (lhs
, rhs
));
3726 /* VAR = VAR + UNKNOWN; */
3732 rhs
.offset
= UNKNOWN_OFFSET
;
3733 process_constraint (new_constraint (lhs
, rhs
));
3736 /* Temporary storage for fake var decls. */
3737 struct obstack fake_var_decl_obstack
;
3739 /* Build a fake VAR_DECL acting as referrer to a DECL_UID. */
3742 build_fake_var_decl (tree type
)
3744 tree decl
= (tree
) XOBNEW (&fake_var_decl_obstack
, struct tree_var_decl
);
3745 memset (decl
, 0, sizeof (struct tree_var_decl
));
3746 TREE_SET_CODE (decl
, VAR_DECL
);
3747 TREE_TYPE (decl
) = type
;
3748 DECL_UID (decl
) = allocate_decl_uid ();
3749 SET_DECL_PT_UID (decl
, -1);
3750 layout_decl (decl
, 0);
3754 /* Create a new artificial heap variable with NAME.
3755 Return the created variable. */
3758 make_heapvar (const char *name
)
3763 heapvar
= build_fake_var_decl (ptr_type_node
);
3764 DECL_EXTERNAL (heapvar
) = 1;
3766 vi
= new_var_info (heapvar
, name
);
3767 vi
->is_artificial_var
= true;
3768 vi
->is_heap_var
= true;
3769 vi
->is_unknown_size_var
= true;
3773 vi
->is_full_var
= true;
3774 insert_vi_for_tree (heapvar
, vi
);
3779 /* Create a new artificial heap variable with NAME and make a
3780 constraint from it to LHS. Set flags according to a tag used
3781 for tracking restrict pointers. */
3784 make_constraint_from_restrict (varinfo_t lhs
, const char *name
)
3786 varinfo_t vi
= make_heapvar (name
);
3787 vi
->is_global_var
= 1;
3788 vi
->may_have_pointers
= 1;
3789 make_constraint_from (lhs
, vi
->id
);
3793 /* Create a new artificial heap variable with NAME and make a
3794 constraint from it to LHS. Set flags according to a tag used
3795 for tracking restrict pointers and make the artificial heap
3796 point to global memory. */
3799 make_constraint_from_global_restrict (varinfo_t lhs
, const char *name
)
3801 varinfo_t vi
= make_constraint_from_restrict (lhs
, name
);
3802 make_copy_constraint (vi
, nonlocal_id
);
3806 /* In IPA mode there are varinfos for different aspects of reach
3807 function designator. One for the points-to set of the return
3808 value, one for the variables that are clobbered by the function,
3809 one for its uses and one for each parameter (including a single
3810 glob for remaining variadic arguments). */
3812 enum { fi_clobbers
= 1, fi_uses
= 2,
3813 fi_static_chain
= 3, fi_result
= 4, fi_parm_base
= 5 };
3815 /* Get a constraint for the requested part of a function designator FI
3816 when operating in IPA mode. */
3818 static struct constraint_expr
3819 get_function_part_constraint (varinfo_t fi
, unsigned part
)
3821 struct constraint_expr c
;
3823 gcc_assert (in_ipa_mode
);
3825 if (fi
->id
== anything_id
)
3827 /* ??? We probably should have a ANYFN special variable. */
3828 c
.var
= anything_id
;
3832 else if (TREE_CODE (fi
->decl
) == FUNCTION_DECL
)
3834 varinfo_t ai
= first_vi_for_offset (fi
, part
);
3838 c
.var
= anything_id
;
3852 /* For non-IPA mode, generate constraints necessary for a call on the
3856 handle_rhs_call (gimple stmt
, vec
<ce_s
> *results
)
3858 struct constraint_expr rhsc
;
3860 bool returns_uses
= false;
3862 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
3864 tree arg
= gimple_call_arg (stmt
, i
);
3865 int flags
= gimple_call_arg_flags (stmt
, i
);
3867 /* If the argument is not used we can ignore it. */
3868 if (flags
& EAF_UNUSED
)
3871 /* As we compute ESCAPED context-insensitive we do not gain
3872 any precision with just EAF_NOCLOBBER but not EAF_NOESCAPE
3873 set. The argument would still get clobbered through the
3875 if ((flags
& EAF_NOCLOBBER
)
3876 && (flags
& EAF_NOESCAPE
))
3878 varinfo_t uses
= get_call_use_vi (stmt
);
3879 if (!(flags
& EAF_DIRECT
))
3881 varinfo_t tem
= new_var_info (NULL_TREE
, "callarg");
3882 make_constraint_to (tem
->id
, arg
);
3883 make_transitive_closure_constraints (tem
);
3884 make_copy_constraint (uses
, tem
->id
);
3887 make_constraint_to (uses
->id
, arg
);
3888 returns_uses
= true;
3890 else if (flags
& EAF_NOESCAPE
)
3892 struct constraint_expr lhs
, rhs
;
3893 varinfo_t uses
= get_call_use_vi (stmt
);
3894 varinfo_t clobbers
= get_call_clobber_vi (stmt
);
3895 varinfo_t tem
= new_var_info (NULL_TREE
, "callarg");
3896 make_constraint_to (tem
->id
, arg
);
3897 if (!(flags
& EAF_DIRECT
))
3898 make_transitive_closure_constraints (tem
);
3899 make_copy_constraint (uses
, tem
->id
);
3900 make_copy_constraint (clobbers
, tem
->id
);
3901 /* Add *tem = nonlocal, do not add *tem = callused as
3902 EAF_NOESCAPE parameters do not escape to other parameters
3903 and all other uses appear in NONLOCAL as well. */
3908 rhs
.var
= nonlocal_id
;
3910 process_constraint (new_constraint (lhs
, rhs
));
3911 returns_uses
= true;
3914 make_escape_constraint (arg
);
3917 /* If we added to the calls uses solution make sure we account for
3918 pointers to it to be returned. */
3921 rhsc
.var
= get_call_use_vi (stmt
)->id
;
3924 results
->safe_push (rhsc
);
3927 /* The static chain escapes as well. */
3928 if (gimple_call_chain (stmt
))
3929 make_escape_constraint (gimple_call_chain (stmt
));
3931 /* And if we applied NRV the address of the return slot escapes as well. */
3932 if (gimple_call_return_slot_opt_p (stmt
)
3933 && gimple_call_lhs (stmt
) != NULL_TREE
3934 && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt
))))
3936 vec
<ce_s
> tmpc
= vNULL
;
3937 struct constraint_expr lhsc
, *c
;
3938 get_constraint_for_address_of (gimple_call_lhs (stmt
), &tmpc
);
3939 lhsc
.var
= escaped_id
;
3942 FOR_EACH_VEC_ELT (tmpc
, i
, c
)
3943 process_constraint (new_constraint (lhsc
, *c
));
3947 /* Regular functions return nonlocal memory. */
3948 rhsc
.var
= nonlocal_id
;
3951 results
->safe_push (rhsc
);
3954 /* For non-IPA mode, generate constraints necessary for a call
3955 that returns a pointer and assigns it to LHS. This simply makes
3956 the LHS point to global and escaped variables. */
3959 handle_lhs_call (gimple stmt
, tree lhs
, int flags
, vec
<ce_s
> rhsc
,
3962 vec
<ce_s
> lhsc
= vNULL
;
3964 get_constraint_for (lhs
, &lhsc
);
3965 /* If the store is to a global decl make sure to
3966 add proper escape constraints. */
3967 lhs
= get_base_address (lhs
);
3970 && is_global_var (lhs
))
3972 struct constraint_expr tmpc
;
3973 tmpc
.var
= escaped_id
;
3976 lhsc
.safe_push (tmpc
);
3979 /* If the call returns an argument unmodified override the rhs
3981 flags
= gimple_call_return_flags (stmt
);
3982 if (flags
& ERF_RETURNS_ARG
3983 && (flags
& ERF_RETURN_ARG_MASK
) < gimple_call_num_args (stmt
))
3987 arg
= gimple_call_arg (stmt
, flags
& ERF_RETURN_ARG_MASK
);
3988 get_constraint_for (arg
, &rhsc
);
3989 process_all_all_constraints (lhsc
, rhsc
);
3992 else if (flags
& ERF_NOALIAS
)
3995 struct constraint_expr tmpc
;
3997 vi
= make_heapvar ("HEAP");
3998 /* We marking allocated storage local, we deal with it becoming
3999 global by escaping and setting of vars_contains_escaped_heap. */
4000 DECL_EXTERNAL (vi
->decl
) = 0;
4001 vi
->is_global_var
= 0;
4002 /* If this is not a real malloc call assume the memory was
4003 initialized and thus may point to global memory. All
4004 builtin functions with the malloc attribute behave in a sane way. */
4006 || DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_NORMAL
)
4007 make_constraint_from (vi
, nonlocal_id
);
4010 tmpc
.type
= ADDRESSOF
;
4011 rhsc
.safe_push (tmpc
);
4012 process_all_all_constraints (lhsc
, rhsc
);
4016 process_all_all_constraints (lhsc
, rhsc
);
4021 /* For non-IPA mode, generate constraints necessary for a call of a
4022 const function that returns a pointer in the statement STMT. */
4025 handle_const_call (gimple stmt
, vec
<ce_s
> *results
)
4027 struct constraint_expr rhsc
;
4030 /* Treat nested const functions the same as pure functions as far
4031 as the static chain is concerned. */
4032 if (gimple_call_chain (stmt
))
4034 varinfo_t uses
= get_call_use_vi (stmt
);
4035 make_transitive_closure_constraints (uses
);
4036 make_constraint_to (uses
->id
, gimple_call_chain (stmt
));
4037 rhsc
.var
= uses
->id
;
4040 results
->safe_push (rhsc
);
4043 /* May return arguments. */
4044 for (k
= 0; k
< gimple_call_num_args (stmt
); ++k
)
4046 tree arg
= gimple_call_arg (stmt
, k
);
4047 vec
<ce_s
> argc
= vNULL
;
4049 struct constraint_expr
*argp
;
4050 get_constraint_for_rhs (arg
, &argc
);
4051 FOR_EACH_VEC_ELT (argc
, i
, argp
)
4052 results
->safe_push (*argp
);
4056 /* May return addresses of globals. */
4057 rhsc
.var
= nonlocal_id
;
4059 rhsc
.type
= ADDRESSOF
;
4060 results
->safe_push (rhsc
);
4063 /* For non-IPA mode, generate constraints necessary for a call to a
4064 pure function in statement STMT. */
4067 handle_pure_call (gimple stmt
, vec
<ce_s
> *results
)
4069 struct constraint_expr rhsc
;
4071 varinfo_t uses
= NULL
;
4073 /* Memory reached from pointer arguments is call-used. */
4074 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
4076 tree arg
= gimple_call_arg (stmt
, i
);
4079 uses
= get_call_use_vi (stmt
);
4080 make_transitive_closure_constraints (uses
);
4082 make_constraint_to (uses
->id
, arg
);
4085 /* The static chain is used as well. */
4086 if (gimple_call_chain (stmt
))
4090 uses
= get_call_use_vi (stmt
);
4091 make_transitive_closure_constraints (uses
);
4093 make_constraint_to (uses
->id
, gimple_call_chain (stmt
));
4096 /* Pure functions may return call-used and nonlocal memory. */
4099 rhsc
.var
= uses
->id
;
4102 results
->safe_push (rhsc
);
4104 rhsc
.var
= nonlocal_id
;
4107 results
->safe_push (rhsc
);
4111 /* Return the varinfo for the callee of CALL. */
4114 get_fi_for_callee (gimple call
)
4116 tree decl
, fn
= gimple_call_fn (call
);
4118 if (fn
&& TREE_CODE (fn
) == OBJ_TYPE_REF
)
4119 fn
= OBJ_TYPE_REF_EXPR (fn
);
4121 /* If we can directly resolve the function being called, do so.
4122 Otherwise, it must be some sort of indirect expression that
4123 we should still be able to handle. */
4124 decl
= gimple_call_addr_fndecl (fn
);
4126 return get_vi_for_tree (decl
);
4128 /* If the function is anything other than a SSA name pointer we have no
4129 clue and should be getting ANYFN (well, ANYTHING for now). */
4130 if (!fn
|| TREE_CODE (fn
) != SSA_NAME
)
4131 return get_varinfo (anything_id
);
4133 if (SSA_NAME_IS_DEFAULT_DEF (fn
)
4134 && (TREE_CODE (SSA_NAME_VAR (fn
)) == PARM_DECL
4135 || TREE_CODE (SSA_NAME_VAR (fn
)) == RESULT_DECL
))
4136 fn
= SSA_NAME_VAR (fn
);
4138 return get_vi_for_tree (fn
);
4141 /* Create constraints for the builtin call T. Return true if the call
4142 was handled, otherwise false. */
4145 find_func_aliases_for_builtin_call (gimple t
)
4147 tree fndecl
= gimple_call_fndecl (t
);
4148 vec
<ce_s
> lhsc
= vNULL
;
4149 vec
<ce_s
> rhsc
= vNULL
;
4152 if (gimple_call_builtin_p (t
, BUILT_IN_NORMAL
))
4153 /* ??? All builtins that are handled here need to be handled
4154 in the alias-oracle query functions explicitly! */
4155 switch (DECL_FUNCTION_CODE (fndecl
))
4157 /* All the following functions return a pointer to the same object
4158 as their first argument points to. The functions do not add
4159 to the ESCAPED solution. The functions make the first argument
4160 pointed to memory point to what the second argument pointed to
4161 memory points to. */
4162 case BUILT_IN_STRCPY
:
4163 case BUILT_IN_STRNCPY
:
4164 case BUILT_IN_BCOPY
:
4165 case BUILT_IN_MEMCPY
:
4166 case BUILT_IN_MEMMOVE
:
4167 case BUILT_IN_MEMPCPY
:
4168 case BUILT_IN_STPCPY
:
4169 case BUILT_IN_STPNCPY
:
4170 case BUILT_IN_STRCAT
:
4171 case BUILT_IN_STRNCAT
:
4172 case BUILT_IN_STRCPY_CHK
:
4173 case BUILT_IN_STRNCPY_CHK
:
4174 case BUILT_IN_MEMCPY_CHK
:
4175 case BUILT_IN_MEMMOVE_CHK
:
4176 case BUILT_IN_MEMPCPY_CHK
:
4177 case BUILT_IN_STPCPY_CHK
:
4178 case BUILT_IN_STPNCPY_CHK
:
4179 case BUILT_IN_STRCAT_CHK
:
4180 case BUILT_IN_STRNCAT_CHK
:
4181 case BUILT_IN_TM_MEMCPY
:
4182 case BUILT_IN_TM_MEMMOVE
:
4184 tree res
= gimple_call_lhs (t
);
4185 tree dest
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (fndecl
)
4186 == BUILT_IN_BCOPY
? 1 : 0));
4187 tree src
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (fndecl
)
4188 == BUILT_IN_BCOPY
? 0 : 1));
4189 if (res
!= NULL_TREE
)
4191 get_constraint_for (res
, &lhsc
);
4192 if (DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_MEMPCPY
4193 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPCPY
4194 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPNCPY
4195 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_MEMPCPY_CHK
4196 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPCPY_CHK
4197 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPNCPY_CHK
)
4198 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &rhsc
);
4200 get_constraint_for (dest
, &rhsc
);
4201 process_all_all_constraints (lhsc
, rhsc
);
4205 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4206 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4209 process_all_all_constraints (lhsc
, rhsc
);
4214 case BUILT_IN_MEMSET
:
4215 case BUILT_IN_MEMSET_CHK
:
4216 case BUILT_IN_TM_MEMSET
:
4218 tree res
= gimple_call_lhs (t
);
4219 tree dest
= gimple_call_arg (t
, 0);
4222 struct constraint_expr ac
;
4223 if (res
!= NULL_TREE
)
4225 get_constraint_for (res
, &lhsc
);
4226 get_constraint_for (dest
, &rhsc
);
4227 process_all_all_constraints (lhsc
, rhsc
);
4231 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4233 if (flag_delete_null_pointer_checks
4234 && integer_zerop (gimple_call_arg (t
, 1)))
4236 ac
.type
= ADDRESSOF
;
4237 ac
.var
= nothing_id
;
4242 ac
.var
= integer_id
;
4245 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
4246 process_constraint (new_constraint (*lhsp
, ac
));
4250 case BUILT_IN_ASSUME_ALIGNED
:
4252 tree res
= gimple_call_lhs (t
);
4253 tree dest
= gimple_call_arg (t
, 0);
4254 if (res
!= NULL_TREE
)
4256 get_constraint_for (res
, &lhsc
);
4257 get_constraint_for (dest
, &rhsc
);
4258 process_all_all_constraints (lhsc
, rhsc
);
4264 /* All the following functions do not return pointers, do not
4265 modify the points-to sets of memory reachable from their
4266 arguments and do not add to the ESCAPED solution. */
4267 case BUILT_IN_SINCOS
:
4268 case BUILT_IN_SINCOSF
:
4269 case BUILT_IN_SINCOSL
:
4270 case BUILT_IN_FREXP
:
4271 case BUILT_IN_FREXPF
:
4272 case BUILT_IN_FREXPL
:
4273 case BUILT_IN_GAMMA_R
:
4274 case BUILT_IN_GAMMAF_R
:
4275 case BUILT_IN_GAMMAL_R
:
4276 case BUILT_IN_LGAMMA_R
:
4277 case BUILT_IN_LGAMMAF_R
:
4278 case BUILT_IN_LGAMMAL_R
:
4280 case BUILT_IN_MODFF
:
4281 case BUILT_IN_MODFL
:
4282 case BUILT_IN_REMQUO
:
4283 case BUILT_IN_REMQUOF
:
4284 case BUILT_IN_REMQUOL
:
4287 case BUILT_IN_STRDUP
:
4288 case BUILT_IN_STRNDUP
:
4289 if (gimple_call_lhs (t
))
4291 handle_lhs_call (t
, gimple_call_lhs (t
), gimple_call_flags (t
),
4293 get_constraint_for_ptr_offset (gimple_call_lhs (t
),
4295 get_constraint_for_ptr_offset (gimple_call_arg (t
, 0),
4299 process_all_all_constraints (lhsc
, rhsc
);
4305 /* String / character search functions return a pointer into the
4306 source string or NULL. */
4307 case BUILT_IN_INDEX
:
4308 case BUILT_IN_STRCHR
:
4309 case BUILT_IN_STRRCHR
:
4310 case BUILT_IN_MEMCHR
:
4311 case BUILT_IN_STRSTR
:
4312 case BUILT_IN_STRPBRK
:
4313 if (gimple_call_lhs (t
))
4315 tree src
= gimple_call_arg (t
, 0);
4316 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4317 constraint_expr nul
;
4318 nul
.var
= nothing_id
;
4320 nul
.type
= ADDRESSOF
;
4321 rhsc
.safe_push (nul
);
4322 get_constraint_for (gimple_call_lhs (t
), &lhsc
);
4323 process_all_all_constraints (lhsc
, rhsc
);
4328 /* Trampolines are special - they set up passing the static
4330 case BUILT_IN_INIT_TRAMPOLINE
:
4332 tree tramp
= gimple_call_arg (t
, 0);
4333 tree nfunc
= gimple_call_arg (t
, 1);
4334 tree frame
= gimple_call_arg (t
, 2);
4336 struct constraint_expr lhs
, *rhsp
;
4339 varinfo_t nfi
= NULL
;
4340 gcc_assert (TREE_CODE (nfunc
) == ADDR_EXPR
);
4341 nfi
= lookup_vi_for_tree (TREE_OPERAND (nfunc
, 0));
4344 lhs
= get_function_part_constraint (nfi
, fi_static_chain
);
4345 get_constraint_for (frame
, &rhsc
);
4346 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4347 process_constraint (new_constraint (lhs
, *rhsp
));
4350 /* Make the frame point to the function for
4351 the trampoline adjustment call. */
4352 get_constraint_for (tramp
, &lhsc
);
4354 get_constraint_for (nfunc
, &rhsc
);
4355 process_all_all_constraints (lhsc
, rhsc
);
4362 /* Else fallthru to generic handling which will let
4363 the frame escape. */
4366 case BUILT_IN_ADJUST_TRAMPOLINE
:
4368 tree tramp
= gimple_call_arg (t
, 0);
4369 tree res
= gimple_call_lhs (t
);
4370 if (in_ipa_mode
&& res
)
4372 get_constraint_for (res
, &lhsc
);
4373 get_constraint_for (tramp
, &rhsc
);
4375 process_all_all_constraints (lhsc
, rhsc
);
4381 CASE_BUILT_IN_TM_STORE (1):
4382 CASE_BUILT_IN_TM_STORE (2):
4383 CASE_BUILT_IN_TM_STORE (4):
4384 CASE_BUILT_IN_TM_STORE (8):
4385 CASE_BUILT_IN_TM_STORE (FLOAT
):
4386 CASE_BUILT_IN_TM_STORE (DOUBLE
):
4387 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
4388 CASE_BUILT_IN_TM_STORE (M64
):
4389 CASE_BUILT_IN_TM_STORE (M128
):
4390 CASE_BUILT_IN_TM_STORE (M256
):
4392 tree addr
= gimple_call_arg (t
, 0);
4393 tree src
= gimple_call_arg (t
, 1);
4395 get_constraint_for (addr
, &lhsc
);
4397 get_constraint_for (src
, &rhsc
);
4398 process_all_all_constraints (lhsc
, rhsc
);
4403 CASE_BUILT_IN_TM_LOAD (1):
4404 CASE_BUILT_IN_TM_LOAD (2):
4405 CASE_BUILT_IN_TM_LOAD (4):
4406 CASE_BUILT_IN_TM_LOAD (8):
4407 CASE_BUILT_IN_TM_LOAD (FLOAT
):
4408 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
4409 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
4410 CASE_BUILT_IN_TM_LOAD (M64
):
4411 CASE_BUILT_IN_TM_LOAD (M128
):
4412 CASE_BUILT_IN_TM_LOAD (M256
):
4414 tree dest
= gimple_call_lhs (t
);
4415 tree addr
= gimple_call_arg (t
, 0);
4417 get_constraint_for (dest
, &lhsc
);
4418 get_constraint_for (addr
, &rhsc
);
4420 process_all_all_constraints (lhsc
, rhsc
);
4425 /* Variadic argument handling needs to be handled in IPA
4427 case BUILT_IN_VA_START
:
4429 tree valist
= gimple_call_arg (t
, 0);
4430 struct constraint_expr rhs
, *lhsp
;
4432 get_constraint_for (valist
, &lhsc
);
4434 /* The va_list gets access to pointers in variadic
4435 arguments. Which we know in the case of IPA analysis
4436 and otherwise are just all nonlocal variables. */
4439 fi
= lookup_vi_for_tree (cfun
->decl
);
4440 rhs
= get_function_part_constraint (fi
, ~0);
4441 rhs
.type
= ADDRESSOF
;
4445 rhs
.var
= nonlocal_id
;
4446 rhs
.type
= ADDRESSOF
;
4449 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
4450 process_constraint (new_constraint (*lhsp
, rhs
));
4452 /* va_list is clobbered. */
4453 make_constraint_to (get_call_clobber_vi (t
)->id
, valist
);
4456 /* va_end doesn't have any effect that matters. */
4457 case BUILT_IN_VA_END
:
4459 /* Alternate return. Simply give up for now. */
4460 case BUILT_IN_RETURN
:
4464 || !(fi
= get_vi_for_tree (cfun
->decl
)))
4465 make_constraint_from (get_varinfo (escaped_id
), anything_id
);
4466 else if (in_ipa_mode
4469 struct constraint_expr lhs
, rhs
;
4470 lhs
= get_function_part_constraint (fi
, fi_result
);
4471 rhs
.var
= anything_id
;
4474 process_constraint (new_constraint (lhs
, rhs
));
4478 /* printf-style functions may have hooks to set pointers to
4479 point to somewhere into the generated string. Leave them
4480 for a later exercise... */
4482 /* Fallthru to general call handling. */;
4488 /* Create constraints for the call T. */
4491 find_func_aliases_for_call (gimple t
)
4493 tree fndecl
= gimple_call_fndecl (t
);
4494 vec
<ce_s
> lhsc
= vNULL
;
4495 vec
<ce_s
> rhsc
= vNULL
;
4498 if (fndecl
!= NULL_TREE
4499 && DECL_BUILT_IN (fndecl
)
4500 && find_func_aliases_for_builtin_call (t
))
4503 fi
= get_fi_for_callee (t
);
4505 || (fndecl
&& !fi
->is_fn_info
))
4507 vec
<ce_s
> rhsc
= vNULL
;
4508 int flags
= gimple_call_flags (t
);
4510 /* Const functions can return their arguments and addresses
4511 of global memory but not of escaped memory. */
4512 if (flags
& (ECF_CONST
|ECF_NOVOPS
))
4514 if (gimple_call_lhs (t
))
4515 handle_const_call (t
, &rhsc
);
4517 /* Pure functions can return addresses in and of memory
4518 reachable from their arguments, but they are not an escape
4519 point for reachable memory of their arguments. */
4520 else if (flags
& (ECF_PURE
|ECF_LOOPING_CONST_OR_PURE
))
4521 handle_pure_call (t
, &rhsc
);
4523 handle_rhs_call (t
, &rhsc
);
4524 if (gimple_call_lhs (t
))
4525 handle_lhs_call (t
, gimple_call_lhs (t
), flags
, rhsc
, fndecl
);
4533 /* Assign all the passed arguments to the appropriate incoming
4534 parameters of the function. */
4535 for (j
= 0; j
< gimple_call_num_args (t
); j
++)
4537 struct constraint_expr lhs
;
4538 struct constraint_expr
*rhsp
;
4539 tree arg
= gimple_call_arg (t
, j
);
4541 get_constraint_for_rhs (arg
, &rhsc
);
4542 lhs
= get_function_part_constraint (fi
, fi_parm_base
+ j
);
4543 while (rhsc
.length () != 0)
4545 rhsp
= &rhsc
.last ();
4546 process_constraint (new_constraint (lhs
, *rhsp
));
4551 /* If we are returning a value, assign it to the result. */
4552 lhsop
= gimple_call_lhs (t
);
4555 struct constraint_expr rhs
;
4556 struct constraint_expr
*lhsp
;
4558 get_constraint_for (lhsop
, &lhsc
);
4559 rhs
= get_function_part_constraint (fi
, fi_result
);
4561 && DECL_RESULT (fndecl
)
4562 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
4564 vec
<ce_s
> tem
= vNULL
;
4565 tem
.safe_push (rhs
);
4570 FOR_EACH_VEC_ELT (lhsc
, j
, lhsp
)
4571 process_constraint (new_constraint (*lhsp
, rhs
));
4574 /* If we pass the result decl by reference, honor that. */
4577 && DECL_RESULT (fndecl
)
4578 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
4580 struct constraint_expr lhs
;
4581 struct constraint_expr
*rhsp
;
4583 get_constraint_for_address_of (lhsop
, &rhsc
);
4584 lhs
= get_function_part_constraint (fi
, fi_result
);
4585 FOR_EACH_VEC_ELT (rhsc
, j
, rhsp
)
4586 process_constraint (new_constraint (lhs
, *rhsp
));
4590 /* If we use a static chain, pass it along. */
4591 if (gimple_call_chain (t
))
4593 struct constraint_expr lhs
;
4594 struct constraint_expr
*rhsp
;
4596 get_constraint_for (gimple_call_chain (t
), &rhsc
);
4597 lhs
= get_function_part_constraint (fi
, fi_static_chain
);
4598 FOR_EACH_VEC_ELT (rhsc
, j
, rhsp
)
4599 process_constraint (new_constraint (lhs
, *rhsp
));
4604 /* Walk statement T setting up aliasing constraints according to the
4605 references found in T. This function is the main part of the
4606 constraint builder. AI points to auxiliary alias information used
4607 when building alias sets and computing alias grouping heuristics. */
4610 find_func_aliases (gimple origt
)
4613 vec
<ce_s
> lhsc
= vNULL
;
4614 vec
<ce_s
> rhsc
= vNULL
;
4615 struct constraint_expr
*c
;
4618 /* Now build constraints expressions. */
4619 if (gimple_code (t
) == GIMPLE_PHI
)
4624 /* For a phi node, assign all the arguments to
4626 get_constraint_for (gimple_phi_result (t
), &lhsc
);
4627 for (i
= 0; i
< gimple_phi_num_args (t
); i
++)
4629 tree strippedrhs
= PHI_ARG_DEF (t
, i
);
4631 STRIP_NOPS (strippedrhs
);
4632 get_constraint_for_rhs (gimple_phi_arg_def (t
, i
), &rhsc
);
4634 FOR_EACH_VEC_ELT (lhsc
, j
, c
)
4636 struct constraint_expr
*c2
;
4637 while (rhsc
.length () > 0)
4640 process_constraint (new_constraint (*c
, *c2
));
4646 /* In IPA mode, we need to generate constraints to pass call
4647 arguments through their calls. There are two cases,
4648 either a GIMPLE_CALL returning a value, or just a plain
4649 GIMPLE_CALL when we are not.
4651 In non-ipa mode, we need to generate constraints for each
4652 pointer passed by address. */
4653 else if (is_gimple_call (t
))
4654 find_func_aliases_for_call (t
);
4656 /* Otherwise, just a regular assignment statement. Only care about
4657 operations with pointer result, others are dealt with as escape
4658 points if they have pointer operands. */
4659 else if (is_gimple_assign (t
))
4661 /* Otherwise, just a regular assignment statement. */
4662 tree lhsop
= gimple_assign_lhs (t
);
4663 tree rhsop
= (gimple_num_ops (t
) == 2) ? gimple_assign_rhs1 (t
) : NULL
;
4665 if (rhsop
&& TREE_CLOBBER_P (rhsop
))
4666 /* Ignore clobbers, they don't actually store anything into
4669 else if (rhsop
&& AGGREGATE_TYPE_P (TREE_TYPE (lhsop
)))
4670 do_structure_copy (lhsop
, rhsop
);
4673 enum tree_code code
= gimple_assign_rhs_code (t
);
4675 get_constraint_for (lhsop
, &lhsc
);
4677 if (FLOAT_TYPE_P (TREE_TYPE (lhsop
)))
4678 /* If the operation produces a floating point result then
4679 assume the value is not produced to transfer a pointer. */
4681 else if (code
== POINTER_PLUS_EXPR
)
4682 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t
),
4683 gimple_assign_rhs2 (t
), &rhsc
);
4684 else if (code
== BIT_AND_EXPR
4685 && TREE_CODE (gimple_assign_rhs2 (t
)) == INTEGER_CST
)
4687 /* Aligning a pointer via a BIT_AND_EXPR is offsetting
4688 the pointer. Handle it by offsetting it by UNKNOWN. */
4689 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t
),
4692 else if ((CONVERT_EXPR_CODE_P (code
)
4693 && !(POINTER_TYPE_P (gimple_expr_type (t
))
4694 && !POINTER_TYPE_P (TREE_TYPE (rhsop
))))
4695 || gimple_assign_single_p (t
))
4696 get_constraint_for_rhs (rhsop
, &rhsc
);
4697 else if (code
== COND_EXPR
)
4699 /* The result is a merge of both COND_EXPR arms. */
4700 vec
<ce_s
> tmp
= vNULL
;
4701 struct constraint_expr
*rhsp
;
4703 get_constraint_for_rhs (gimple_assign_rhs2 (t
), &rhsc
);
4704 get_constraint_for_rhs (gimple_assign_rhs3 (t
), &tmp
);
4705 FOR_EACH_VEC_ELT (tmp
, i
, rhsp
)
4706 rhsc
.safe_push (*rhsp
);
4709 else if (truth_value_p (code
))
4710 /* Truth value results are not pointer (parts). Or at least
4711 very very unreasonable obfuscation of a part. */
4715 /* All other operations are merges. */
4716 vec
<ce_s
> tmp
= vNULL
;
4717 struct constraint_expr
*rhsp
;
4719 get_constraint_for_rhs (gimple_assign_rhs1 (t
), &rhsc
);
4720 for (i
= 2; i
< gimple_num_ops (t
); ++i
)
4722 get_constraint_for_rhs (gimple_op (t
, i
), &tmp
);
4723 FOR_EACH_VEC_ELT (tmp
, j
, rhsp
)
4724 rhsc
.safe_push (*rhsp
);
4729 process_all_all_constraints (lhsc
, rhsc
);
4731 /* If there is a store to a global variable the rhs escapes. */
4732 if ((lhsop
= get_base_address (lhsop
)) != NULL_TREE
4734 && is_global_var (lhsop
)
4736 || DECL_EXTERNAL (lhsop
) || TREE_PUBLIC (lhsop
)))
4737 make_escape_constraint (rhsop
);
4739 /* Handle escapes through return. */
4740 else if (gimple_code (t
) == GIMPLE_RETURN
4741 && gimple_return_retval (t
) != NULL_TREE
)
4745 || !(fi
= get_vi_for_tree (cfun
->decl
)))
4746 make_escape_constraint (gimple_return_retval (t
));
4747 else if (in_ipa_mode
4750 struct constraint_expr lhs
;
4751 struct constraint_expr
*rhsp
;
4754 lhs
= get_function_part_constraint (fi
, fi_result
);
4755 get_constraint_for_rhs (gimple_return_retval (t
), &rhsc
);
4756 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4757 process_constraint (new_constraint (lhs
, *rhsp
));
4760 /* Handle asms conservatively by adding escape constraints to everything. */
4761 else if (gimple_code (t
) == GIMPLE_ASM
)
4763 unsigned i
, noutputs
;
4764 const char **oconstraints
;
4765 const char *constraint
;
4766 bool allows_mem
, allows_reg
, is_inout
;
4768 noutputs
= gimple_asm_noutputs (t
);
4769 oconstraints
= XALLOCAVEC (const char *, noutputs
);
4771 for (i
= 0; i
< noutputs
; ++i
)
4773 tree link
= gimple_asm_output_op (t
, i
);
4774 tree op
= TREE_VALUE (link
);
4776 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
4777 oconstraints
[i
] = constraint
;
4778 parse_output_constraint (&constraint
, i
, 0, 0, &allows_mem
,
4779 &allows_reg
, &is_inout
);
4781 /* A memory constraint makes the address of the operand escape. */
4782 if (!allows_reg
&& allows_mem
)
4783 make_escape_constraint (build_fold_addr_expr (op
));
4785 /* The asm may read global memory, so outputs may point to
4786 any global memory. */
4789 vec
<ce_s
> lhsc
= vNULL
;
4790 struct constraint_expr rhsc
, *lhsp
;
4792 get_constraint_for (op
, &lhsc
);
4793 rhsc
.var
= nonlocal_id
;
4796 FOR_EACH_VEC_ELT (lhsc
, j
, lhsp
)
4797 process_constraint (new_constraint (*lhsp
, rhsc
));
4801 for (i
= 0; i
< gimple_asm_ninputs (t
); ++i
)
4803 tree link
= gimple_asm_input_op (t
, i
);
4804 tree op
= TREE_VALUE (link
);
4806 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
4808 parse_input_constraint (&constraint
, 0, 0, noutputs
, 0, oconstraints
,
4809 &allows_mem
, &allows_reg
);
4811 /* A memory constraint makes the address of the operand escape. */
4812 if (!allows_reg
&& allows_mem
)
4813 make_escape_constraint (build_fold_addr_expr (op
));
4814 /* Strictly we'd only need the constraint to ESCAPED if
4815 the asm clobbers memory, otherwise using something
4816 along the lines of per-call clobbers/uses would be enough. */
4818 make_escape_constraint (op
);
4827 /* Create a constraint adding to the clobber set of FI the memory
4828 pointed to by PTR. */
4831 process_ipa_clobber (varinfo_t fi
, tree ptr
)
4833 vec
<ce_s
> ptrc
= vNULL
;
4834 struct constraint_expr
*c
, lhs
;
4836 get_constraint_for_rhs (ptr
, &ptrc
);
4837 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4838 FOR_EACH_VEC_ELT (ptrc
, i
, c
)
4839 process_constraint (new_constraint (lhs
, *c
));
4843 /* Walk statement T setting up clobber and use constraints according to the
4844 references found in T. This function is a main part of the
4845 IPA constraint builder. */
4848 find_func_clobbers (gimple origt
)
4851 vec
<ce_s
> lhsc
= vNULL
;
4852 vec
<ce_s
> rhsc
= vNULL
;
4855 /* Add constraints for clobbered/used in IPA mode.
4856 We are not interested in what automatic variables are clobbered
4857 or used as we only use the information in the caller to which
4858 they do not escape. */
4859 gcc_assert (in_ipa_mode
);
4861 /* If the stmt refers to memory in any way it better had a VUSE. */
4862 if (gimple_vuse (t
) == NULL_TREE
)
4865 /* We'd better have function information for the current function. */
4866 fi
= lookup_vi_for_tree (cfun
->decl
);
4867 gcc_assert (fi
!= NULL
);
4869 /* Account for stores in assignments and calls. */
4870 if (gimple_vdef (t
) != NULL_TREE
4871 && gimple_has_lhs (t
))
4873 tree lhs
= gimple_get_lhs (t
);
4875 while (handled_component_p (tem
))
4876 tem
= TREE_OPERAND (tem
, 0);
4878 && !auto_var_in_fn_p (tem
, cfun
->decl
))
4879 || INDIRECT_REF_P (tem
)
4880 || (TREE_CODE (tem
) == MEM_REF
4881 && !(TREE_CODE (TREE_OPERAND (tem
, 0)) == ADDR_EXPR
4883 (TREE_OPERAND (TREE_OPERAND (tem
, 0), 0), cfun
->decl
))))
4885 struct constraint_expr lhsc
, *rhsp
;
4887 lhsc
= get_function_part_constraint (fi
, fi_clobbers
);
4888 get_constraint_for_address_of (lhs
, &rhsc
);
4889 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4890 process_constraint (new_constraint (lhsc
, *rhsp
));
4895 /* Account for uses in assigments and returns. */
4896 if (gimple_assign_single_p (t
)
4897 || (gimple_code (t
) == GIMPLE_RETURN
4898 && gimple_return_retval (t
) != NULL_TREE
))
4900 tree rhs
= (gimple_assign_single_p (t
)
4901 ? gimple_assign_rhs1 (t
) : gimple_return_retval (t
));
4903 while (handled_component_p (tem
))
4904 tem
= TREE_OPERAND (tem
, 0);
4906 && !auto_var_in_fn_p (tem
, cfun
->decl
))
4907 || INDIRECT_REF_P (tem
)
4908 || (TREE_CODE (tem
) == MEM_REF
4909 && !(TREE_CODE (TREE_OPERAND (tem
, 0)) == ADDR_EXPR
4911 (TREE_OPERAND (TREE_OPERAND (tem
, 0), 0), cfun
->decl
))))
4913 struct constraint_expr lhs
, *rhsp
;
4915 lhs
= get_function_part_constraint (fi
, fi_uses
);
4916 get_constraint_for_address_of (rhs
, &rhsc
);
4917 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4918 process_constraint (new_constraint (lhs
, *rhsp
));
4923 if (is_gimple_call (t
))
4925 varinfo_t cfi
= NULL
;
4926 tree decl
= gimple_call_fndecl (t
);
4927 struct constraint_expr lhs
, rhs
;
4930 /* For builtins we do not have separate function info. For those
4931 we do not generate escapes for we have to generate clobbers/uses. */
4932 if (gimple_call_builtin_p (t
, BUILT_IN_NORMAL
))
4933 switch (DECL_FUNCTION_CODE (decl
))
4935 /* The following functions use and clobber memory pointed to
4936 by their arguments. */
4937 case BUILT_IN_STRCPY
:
4938 case BUILT_IN_STRNCPY
:
4939 case BUILT_IN_BCOPY
:
4940 case BUILT_IN_MEMCPY
:
4941 case BUILT_IN_MEMMOVE
:
4942 case BUILT_IN_MEMPCPY
:
4943 case BUILT_IN_STPCPY
:
4944 case BUILT_IN_STPNCPY
:
4945 case BUILT_IN_STRCAT
:
4946 case BUILT_IN_STRNCAT
:
4947 case BUILT_IN_STRCPY_CHK
:
4948 case BUILT_IN_STRNCPY_CHK
:
4949 case BUILT_IN_MEMCPY_CHK
:
4950 case BUILT_IN_MEMMOVE_CHK
:
4951 case BUILT_IN_MEMPCPY_CHK
:
4952 case BUILT_IN_STPCPY_CHK
:
4953 case BUILT_IN_STPNCPY_CHK
:
4954 case BUILT_IN_STRCAT_CHK
:
4955 case BUILT_IN_STRNCAT_CHK
:
4957 tree dest
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (decl
)
4958 == BUILT_IN_BCOPY
? 1 : 0));
4959 tree src
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (decl
)
4960 == BUILT_IN_BCOPY
? 0 : 1));
4962 struct constraint_expr
*rhsp
, *lhsp
;
4963 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4964 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4965 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
4966 process_constraint (new_constraint (lhs
, *lhsp
));
4968 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4969 lhs
= get_function_part_constraint (fi
, fi_uses
);
4970 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4971 process_constraint (new_constraint (lhs
, *rhsp
));
4975 /* The following function clobbers memory pointed to by
4977 case BUILT_IN_MEMSET
:
4978 case BUILT_IN_MEMSET_CHK
:
4980 tree dest
= gimple_call_arg (t
, 0);
4983 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4984 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4985 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
4986 process_constraint (new_constraint (lhs
, *lhsp
));
4990 /* The following functions clobber their second and third
4992 case BUILT_IN_SINCOS
:
4993 case BUILT_IN_SINCOSF
:
4994 case BUILT_IN_SINCOSL
:
4996 process_ipa_clobber (fi
, gimple_call_arg (t
, 1));
4997 process_ipa_clobber (fi
, gimple_call_arg (t
, 2));
5000 /* The following functions clobber their second argument. */
5001 case BUILT_IN_FREXP
:
5002 case BUILT_IN_FREXPF
:
5003 case BUILT_IN_FREXPL
:
5004 case BUILT_IN_LGAMMA_R
:
5005 case BUILT_IN_LGAMMAF_R
:
5006 case BUILT_IN_LGAMMAL_R
:
5007 case BUILT_IN_GAMMA_R
:
5008 case BUILT_IN_GAMMAF_R
:
5009 case BUILT_IN_GAMMAL_R
:
5011 case BUILT_IN_MODFF
:
5012 case BUILT_IN_MODFL
:
5014 process_ipa_clobber (fi
, gimple_call_arg (t
, 1));
5017 /* The following functions clobber their third argument. */
5018 case BUILT_IN_REMQUO
:
5019 case BUILT_IN_REMQUOF
:
5020 case BUILT_IN_REMQUOL
:
5022 process_ipa_clobber (fi
, gimple_call_arg (t
, 2));
5025 /* The following functions neither read nor clobber memory. */
5026 case BUILT_IN_ASSUME_ALIGNED
:
5029 /* Trampolines are of no interest to us. */
5030 case BUILT_IN_INIT_TRAMPOLINE
:
5031 case BUILT_IN_ADJUST_TRAMPOLINE
:
5033 case BUILT_IN_VA_START
:
5034 case BUILT_IN_VA_END
:
5036 /* printf-style functions may have hooks to set pointers to
5037 point to somewhere into the generated string. Leave them
5038 for a later exercise... */
5040 /* Fallthru to general call handling. */;
5043 /* Parameters passed by value are used. */
5044 lhs
= get_function_part_constraint (fi
, fi_uses
);
5045 for (i
= 0; i
< gimple_call_num_args (t
); i
++)
5047 struct constraint_expr
*rhsp
;
5048 tree arg
= gimple_call_arg (t
, i
);
5050 if (TREE_CODE (arg
) == SSA_NAME
5051 || is_gimple_min_invariant (arg
))
5054 get_constraint_for_address_of (arg
, &rhsc
);
5055 FOR_EACH_VEC_ELT (rhsc
, j
, rhsp
)
5056 process_constraint (new_constraint (lhs
, *rhsp
));
5060 /* Build constraints for propagating clobbers/uses along the
5062 cfi
= get_fi_for_callee (t
);
5063 if (cfi
->id
== anything_id
)
5065 if (gimple_vdef (t
))
5066 make_constraint_from (first_vi_for_offset (fi
, fi_clobbers
),
5068 make_constraint_from (first_vi_for_offset (fi
, fi_uses
),
5073 /* For callees without function info (that's external functions),
5074 ESCAPED is clobbered and used. */
5075 if (gimple_call_fndecl (t
)
5076 && !cfi
->is_fn_info
)
5080 if (gimple_vdef (t
))
5081 make_copy_constraint (first_vi_for_offset (fi
, fi_clobbers
),
5083 make_copy_constraint (first_vi_for_offset (fi
, fi_uses
), escaped_id
);
5085 /* Also honor the call statement use/clobber info. */
5086 if ((vi
= lookup_call_clobber_vi (t
)) != NULL
)
5087 make_copy_constraint (first_vi_for_offset (fi
, fi_clobbers
),
5089 if ((vi
= lookup_call_use_vi (t
)) != NULL
)
5090 make_copy_constraint (first_vi_for_offset (fi
, fi_uses
),
5095 /* Otherwise the caller clobbers and uses what the callee does.
5096 ??? This should use a new complex constraint that filters
5097 local variables of the callee. */
5098 if (gimple_vdef (t
))
5100 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
5101 rhs
= get_function_part_constraint (cfi
, fi_clobbers
);
5102 process_constraint (new_constraint (lhs
, rhs
));
5104 lhs
= get_function_part_constraint (fi
, fi_uses
);
5105 rhs
= get_function_part_constraint (cfi
, fi_uses
);
5106 process_constraint (new_constraint (lhs
, rhs
));
5108 else if (gimple_code (t
) == GIMPLE_ASM
)
5110 /* ??? Ick. We can do better. */
5111 if (gimple_vdef (t
))
5112 make_constraint_from (first_vi_for_offset (fi
, fi_clobbers
),
5114 make_constraint_from (first_vi_for_offset (fi
, fi_uses
),
5122 /* Find the first varinfo in the same variable as START that overlaps with
5123 OFFSET. Return NULL if we can't find one. */
5126 first_vi_for_offset (varinfo_t start
, unsigned HOST_WIDE_INT offset
)
5128 /* If the offset is outside of the variable, bail out. */
5129 if (offset
>= start
->fullsize
)
5132 /* If we cannot reach offset from start, lookup the first field
5133 and start from there. */
5134 if (start
->offset
> offset
)
5135 start
= get_varinfo (start
->head
);
5139 /* We may not find a variable in the field list with the actual
5140 offset when when we have glommed a structure to a variable.
5141 In that case, however, offset should still be within the size
5143 if (offset
>= start
->offset
5144 && (offset
- start
->offset
) < start
->size
)
5147 start
= vi_next (start
);
5153 /* Find the first varinfo in the same variable as START that overlaps with
5154 OFFSET. If there is no such varinfo the varinfo directly preceding
5155 OFFSET is returned. */
5158 first_or_preceding_vi_for_offset (varinfo_t start
,
5159 unsigned HOST_WIDE_INT offset
)
5161 /* If we cannot reach offset from start, lookup the first field
5162 and start from there. */
5163 if (start
->offset
> offset
)
5164 start
= get_varinfo (start
->head
);
5166 /* We may not find a variable in the field list with the actual
5167 offset when when we have glommed a structure to a variable.
5168 In that case, however, offset should still be within the size
5170 If we got beyond the offset we look for return the field
5171 directly preceding offset which may be the last field. */
5173 && offset
>= start
->offset
5174 && !((offset
- start
->offset
) < start
->size
))
5175 start
= vi_next (start
);
5181 /* This structure is used during pushing fields onto the fieldstack
5182 to track the offset of the field, since bitpos_of_field gives it
5183 relative to its immediate containing type, and we want it relative
5184 to the ultimate containing object. */
5188 /* Offset from the base of the base containing object to this field. */
5189 HOST_WIDE_INT offset
;
5191 /* Size, in bits, of the field. */
5192 unsigned HOST_WIDE_INT size
;
5194 unsigned has_unknown_size
: 1;
5196 unsigned must_have_pointers
: 1;
5198 unsigned may_have_pointers
: 1;
5200 unsigned only_restrict_pointers
: 1;
5202 typedef struct fieldoff fieldoff_s
;
5205 /* qsort comparison function for two fieldoff's PA and PB */
5208 fieldoff_compare (const void *pa
, const void *pb
)
5210 const fieldoff_s
*foa
= (const fieldoff_s
*)pa
;
5211 const fieldoff_s
*fob
= (const fieldoff_s
*)pb
;
5212 unsigned HOST_WIDE_INT foasize
, fobsize
;
5214 if (foa
->offset
< fob
->offset
)
5216 else if (foa
->offset
> fob
->offset
)
5219 foasize
= foa
->size
;
5220 fobsize
= fob
->size
;
5221 if (foasize
< fobsize
)
5223 else if (foasize
> fobsize
)
5228 /* Sort a fieldstack according to the field offset and sizes. */
5230 sort_fieldstack (vec
<fieldoff_s
> fieldstack
)
5232 fieldstack
.qsort (fieldoff_compare
);
5235 /* Return true if T is a type that can have subvars. */
5238 type_can_have_subvars (const_tree t
)
5240 /* Aggregates without overlapping fields can have subvars. */
5241 return TREE_CODE (t
) == RECORD_TYPE
;
5244 /* Return true if V is a tree that we can have subvars for.
5245 Normally, this is any aggregate type. Also complex
5246 types which are not gimple registers can have subvars. */
5249 var_can_have_subvars (const_tree v
)
5251 /* Volatile variables should never have subvars. */
5252 if (TREE_THIS_VOLATILE (v
))
5255 /* Non decls or memory tags can never have subvars. */
5259 return type_can_have_subvars (TREE_TYPE (v
));
5262 /* Return true if T is a type that does contain pointers. */
5265 type_must_have_pointers (tree type
)
5267 if (POINTER_TYPE_P (type
))
5270 if (TREE_CODE (type
) == ARRAY_TYPE
)
5271 return type_must_have_pointers (TREE_TYPE (type
));
5273 /* A function or method can have pointers as arguments, so track
5274 those separately. */
5275 if (TREE_CODE (type
) == FUNCTION_TYPE
5276 || TREE_CODE (type
) == METHOD_TYPE
)
5283 field_must_have_pointers (tree t
)
5285 return type_must_have_pointers (TREE_TYPE (t
));
5288 /* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
5289 the fields of TYPE onto fieldstack, recording their offsets along
5292 OFFSET is used to keep track of the offset in this entire
5293 structure, rather than just the immediately containing structure.
5294 Returns false if the caller is supposed to handle the field we
5298 push_fields_onto_fieldstack (tree type
, vec
<fieldoff_s
> *fieldstack
,
5299 HOST_WIDE_INT offset
)
5302 bool empty_p
= true;
5304 if (TREE_CODE (type
) != RECORD_TYPE
)
5307 /* If the vector of fields is growing too big, bail out early.
5308 Callers check for vec::length <= MAX_FIELDS_FOR_FIELD_SENSITIVE, make
5310 if (fieldstack
->length () > MAX_FIELDS_FOR_FIELD_SENSITIVE
)
5313 for (field
= TYPE_FIELDS (type
); field
; field
= DECL_CHAIN (field
))
5314 if (TREE_CODE (field
) == FIELD_DECL
)
5317 HOST_WIDE_INT foff
= bitpos_of_field (field
);
5319 if (!var_can_have_subvars (field
)
5320 || TREE_CODE (TREE_TYPE (field
)) == QUAL_UNION_TYPE
5321 || TREE_CODE (TREE_TYPE (field
)) == UNION_TYPE
)
5323 else if (!push_fields_onto_fieldstack
5324 (TREE_TYPE (field
), fieldstack
, offset
+ foff
)
5325 && (DECL_SIZE (field
)
5326 && !integer_zerop (DECL_SIZE (field
))))
5327 /* Empty structures may have actual size, like in C++. So
5328 see if we didn't push any subfields and the size is
5329 nonzero, push the field onto the stack. */
5334 fieldoff_s
*pair
= NULL
;
5335 bool has_unknown_size
= false;
5336 bool must_have_pointers_p
;
5338 if (!fieldstack
->is_empty ())
5339 pair
= &fieldstack
->last ();
5341 /* If there isn't anything at offset zero, create sth. */
5343 && offset
+ foff
!= 0)
5345 fieldoff_s e
= {0, offset
+ foff
, false, false, false, false};
5346 pair
= fieldstack
->safe_push (e
);
5349 if (!DECL_SIZE (field
)
5350 || !tree_fits_uhwi_p (DECL_SIZE (field
)))
5351 has_unknown_size
= true;
5353 /* If adjacent fields do not contain pointers merge them. */
5354 must_have_pointers_p
= field_must_have_pointers (field
);
5356 && !has_unknown_size
5357 && !must_have_pointers_p
5358 && !pair
->must_have_pointers
5359 && !pair
->has_unknown_size
5360 && pair
->offset
+ (HOST_WIDE_INT
)pair
->size
== offset
+ foff
)
5362 pair
->size
+= tree_to_hwi (DECL_SIZE (field
));
5367 e
.offset
= offset
+ foff
;
5368 e
.has_unknown_size
= has_unknown_size
;
5369 if (!has_unknown_size
)
5370 e
.size
= tree_to_hwi (DECL_SIZE (field
));
5373 e
.must_have_pointers
= must_have_pointers_p
;
5374 e
.may_have_pointers
= true;
5375 e
.only_restrict_pointers
5376 = (!has_unknown_size
5377 && POINTER_TYPE_P (TREE_TYPE (field
))
5378 && TYPE_RESTRICT (TREE_TYPE (field
)));
5379 fieldstack
->safe_push (e
);
5389 /* Count the number of arguments DECL has, and set IS_VARARGS to true
5390 if it is a varargs function. */
5393 count_num_arguments (tree decl
, bool *is_varargs
)
5395 unsigned int num
= 0;
5398 /* Capture named arguments for K&R functions. They do not
5399 have a prototype and thus no TYPE_ARG_TYPES. */
5400 for (t
= DECL_ARGUMENTS (decl
); t
; t
= DECL_CHAIN (t
))
5403 /* Check if the function has variadic arguments. */
5404 for (t
= TYPE_ARG_TYPES (TREE_TYPE (decl
)); t
; t
= TREE_CHAIN (t
))
5405 if (TREE_VALUE (t
) == void_type_node
)
5413 /* Creation function node for DECL, using NAME, and return the index
5414 of the variable we've created for the function. */
5417 create_function_info_for (tree decl
, const char *name
)
5419 struct function
*fn
= DECL_STRUCT_FUNCTION (decl
);
5420 varinfo_t vi
, prev_vi
;
5423 bool is_varargs
= false;
5424 unsigned int num_args
= count_num_arguments (decl
, &is_varargs
);
5426 /* Create the variable info. */
5428 vi
= new_var_info (decl
, name
);
5431 vi
->fullsize
= fi_parm_base
+ num_args
;
5433 vi
->may_have_pointers
= false;
5436 insert_vi_for_tree (vi
->decl
, vi
);
5440 /* Create a variable for things the function clobbers and one for
5441 things the function uses. */
5443 varinfo_t clobbervi
, usevi
;
5444 const char *newname
;
5447 asprintf (&tempname
, "%s.clobber", name
);
5448 newname
= ggc_strdup (tempname
);
5451 clobbervi
= new_var_info (NULL
, newname
);
5452 clobbervi
->offset
= fi_clobbers
;
5453 clobbervi
->size
= 1;
5454 clobbervi
->fullsize
= vi
->fullsize
;
5455 clobbervi
->is_full_var
= true;
5456 clobbervi
->is_global_var
= false;
5457 gcc_assert (prev_vi
->offset
< clobbervi
->offset
);
5458 prev_vi
->next
= clobbervi
->id
;
5459 prev_vi
= clobbervi
;
5461 asprintf (&tempname
, "%s.use", name
);
5462 newname
= ggc_strdup (tempname
);
5465 usevi
= new_var_info (NULL
, newname
);
5466 usevi
->offset
= fi_uses
;
5468 usevi
->fullsize
= vi
->fullsize
;
5469 usevi
->is_full_var
= true;
5470 usevi
->is_global_var
= false;
5471 gcc_assert (prev_vi
->offset
< usevi
->offset
);
5472 prev_vi
->next
= usevi
->id
;
5476 /* And one for the static chain. */
5477 if (fn
->static_chain_decl
!= NULL_TREE
)
5480 const char *newname
;
5483 asprintf (&tempname
, "%s.chain", name
);
5484 newname
= ggc_strdup (tempname
);
5487 chainvi
= new_var_info (fn
->static_chain_decl
, newname
);
5488 chainvi
->offset
= fi_static_chain
;
5490 chainvi
->fullsize
= vi
->fullsize
;
5491 chainvi
->is_full_var
= true;
5492 chainvi
->is_global_var
= false;
5493 gcc_assert (prev_vi
->offset
< chainvi
->offset
);
5494 prev_vi
->next
= chainvi
->id
;
5496 insert_vi_for_tree (fn
->static_chain_decl
, chainvi
);
5499 /* Create a variable for the return var. */
5500 if (DECL_RESULT (decl
) != NULL
5501 || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl
))))
5504 const char *newname
;
5506 tree resultdecl
= decl
;
5508 if (DECL_RESULT (decl
))
5509 resultdecl
= DECL_RESULT (decl
);
5511 asprintf (&tempname
, "%s.result", name
);
5512 newname
= ggc_strdup (tempname
);
5515 resultvi
= new_var_info (resultdecl
, newname
);
5516 resultvi
->offset
= fi_result
;
5518 resultvi
->fullsize
= vi
->fullsize
;
5519 resultvi
->is_full_var
= true;
5520 if (DECL_RESULT (decl
))
5521 resultvi
->may_have_pointers
= true;
5522 gcc_assert (prev_vi
->offset
< resultvi
->offset
);
5523 prev_vi
->next
= resultvi
->id
;
5525 if (DECL_RESULT (decl
))
5526 insert_vi_for_tree (DECL_RESULT (decl
), resultvi
);
5529 /* Set up variables for each argument. */
5530 arg
= DECL_ARGUMENTS (decl
);
5531 for (i
= 0; i
< num_args
; i
++)
5534 const char *newname
;
5536 tree argdecl
= decl
;
5541 asprintf (&tempname
, "%s.arg%d", name
, i
);
5542 newname
= ggc_strdup (tempname
);
5545 argvi
= new_var_info (argdecl
, newname
);
5546 argvi
->offset
= fi_parm_base
+ i
;
5548 argvi
->is_full_var
= true;
5549 argvi
->fullsize
= vi
->fullsize
;
5551 argvi
->may_have_pointers
= true;
5552 gcc_assert (prev_vi
->offset
< argvi
->offset
);
5553 prev_vi
->next
= argvi
->id
;
5557 insert_vi_for_tree (arg
, argvi
);
5558 arg
= DECL_CHAIN (arg
);
5562 /* Add one representative for all further args. */
5566 const char *newname
;
5570 asprintf (&tempname
, "%s.varargs", name
);
5571 newname
= ggc_strdup (tempname
);
5574 /* We need sth that can be pointed to for va_start. */
5575 decl
= build_fake_var_decl (ptr_type_node
);
5577 argvi
= new_var_info (decl
, newname
);
5578 argvi
->offset
= fi_parm_base
+ num_args
;
5580 argvi
->is_full_var
= true;
5581 argvi
->is_heap_var
= true;
5582 argvi
->fullsize
= vi
->fullsize
;
5583 gcc_assert (prev_vi
->offset
< argvi
->offset
);
5584 prev_vi
->next
= argvi
->id
;
5592 /* Return true if FIELDSTACK contains fields that overlap.
5593 FIELDSTACK is assumed to be sorted by offset. */
5596 check_for_overlaps (vec
<fieldoff_s
> fieldstack
)
5598 fieldoff_s
*fo
= NULL
;
5600 HOST_WIDE_INT lastoffset
= -1;
5602 FOR_EACH_VEC_ELT (fieldstack
, i
, fo
)
5604 if (fo
->offset
== lastoffset
)
5606 lastoffset
= fo
->offset
;
5611 /* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
5612 This will also create any varinfo structures necessary for fields
5616 create_variable_info_for_1 (tree decl
, const char *name
)
5618 varinfo_t vi
, newvi
;
5619 tree decl_type
= TREE_TYPE (decl
);
5620 tree declsize
= DECL_P (decl
) ? DECL_SIZE (decl
) : TYPE_SIZE (decl_type
);
5621 vec
<fieldoff_s
> fieldstack
= vNULL
;
5626 || !tree_fits_uhwi_p (declsize
))
5628 vi
= new_var_info (decl
, name
);
5632 vi
->is_unknown_size_var
= true;
5633 vi
->is_full_var
= true;
5634 vi
->may_have_pointers
= true;
5638 /* Collect field information. */
5639 if (use_field_sensitive
5640 && var_can_have_subvars (decl
)
5641 /* ??? Force us to not use subfields for global initializers
5642 in IPA mode. Else we'd have to parse arbitrary initializers. */
5644 && is_global_var (decl
)
5645 && DECL_INITIAL (decl
)))
5647 fieldoff_s
*fo
= NULL
;
5648 bool notokay
= false;
5651 push_fields_onto_fieldstack (decl_type
, &fieldstack
, 0);
5653 for (i
= 0; !notokay
&& fieldstack
.iterate (i
, &fo
); i
++)
5654 if (fo
->has_unknown_size
5661 /* We can't sort them if we have a field with a variable sized type,
5662 which will make notokay = true. In that case, we are going to return
5663 without creating varinfos for the fields anyway, so sorting them is a
5667 sort_fieldstack (fieldstack
);
5668 /* Due to some C++ FE issues, like PR 22488, we might end up
5669 what appear to be overlapping fields even though they,
5670 in reality, do not overlap. Until the C++ FE is fixed,
5671 we will simply disable field-sensitivity for these cases. */
5672 notokay
= check_for_overlaps (fieldstack
);
5676 fieldstack
.release ();
5679 /* If we didn't end up collecting sub-variables create a full
5680 variable for the decl. */
5681 if (fieldstack
.length () <= 1
5682 || fieldstack
.length () > MAX_FIELDS_FOR_FIELD_SENSITIVE
)
5684 vi
= new_var_info (decl
, name
);
5686 vi
->may_have_pointers
= true;
5687 vi
->fullsize
= tree_to_hwi (declsize
);
5688 vi
->size
= vi
->fullsize
;
5689 vi
->is_full_var
= true;
5690 fieldstack
.release ();
5694 vi
= new_var_info (decl
, name
);
5695 vi
->fullsize
= tree_to_hwi (declsize
);
5696 for (i
= 0, newvi
= vi
;
5697 fieldstack
.iterate (i
, &fo
);
5698 ++i
, newvi
= vi_next (newvi
))
5700 const char *newname
= "NULL";
5705 asprintf (&tempname
, "%s." HOST_WIDE_INT_PRINT_DEC
5706 "+" HOST_WIDE_INT_PRINT_DEC
, name
, fo
->offset
, fo
->size
);
5707 newname
= ggc_strdup (tempname
);
5710 newvi
->name
= newname
;
5711 newvi
->offset
= fo
->offset
;
5712 newvi
->size
= fo
->size
;
5713 newvi
->fullsize
= vi
->fullsize
;
5714 newvi
->may_have_pointers
= fo
->may_have_pointers
;
5715 newvi
->only_restrict_pointers
= fo
->only_restrict_pointers
;
5716 if (i
+ 1 < fieldstack
.length ())
5718 varinfo_t tem
= new_var_info (decl
, name
);
5719 newvi
->next
= tem
->id
;
5724 fieldstack
.release ();
5730 create_variable_info_for (tree decl
, const char *name
)
5732 varinfo_t vi
= create_variable_info_for_1 (decl
, name
);
5733 unsigned int id
= vi
->id
;
5735 insert_vi_for_tree (decl
, vi
);
5737 if (TREE_CODE (decl
) != VAR_DECL
)
5740 /* Create initial constraints for globals. */
5741 for (; vi
; vi
= vi_next (vi
))
5743 if (!vi
->may_have_pointers
5744 || !vi
->is_global_var
)
5747 /* Mark global restrict qualified pointers. */
5748 if ((POINTER_TYPE_P (TREE_TYPE (decl
))
5749 && TYPE_RESTRICT (TREE_TYPE (decl
)))
5750 || vi
->only_restrict_pointers
)
5752 make_constraint_from_global_restrict (vi
, "GLOBAL_RESTRICT");
5756 /* In non-IPA mode the initializer from nonlocal is all we need. */
5758 || DECL_HARD_REGISTER (decl
))
5759 make_copy_constraint (vi
, nonlocal_id
);
5761 /* In IPA mode parse the initializer and generate proper constraints
5765 struct varpool_node
*vnode
= varpool_get_node (decl
);
5767 /* For escaped variables initialize them from nonlocal. */
5768 if (!varpool_all_refs_explicit_p (vnode
))
5769 make_copy_constraint (vi
, nonlocal_id
);
5771 /* If this is a global variable with an initializer and we are in
5772 IPA mode generate constraints for it. */
5773 if (DECL_INITIAL (decl
)
5774 && vnode
->definition
)
5776 vec
<ce_s
> rhsc
= vNULL
;
5777 struct constraint_expr lhs
, *rhsp
;
5779 get_constraint_for_rhs (DECL_INITIAL (decl
), &rhsc
);
5783 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
5784 process_constraint (new_constraint (lhs
, *rhsp
));
5785 /* If this is a variable that escapes from the unit
5786 the initializer escapes as well. */
5787 if (!varpool_all_refs_explicit_p (vnode
))
5789 lhs
.var
= escaped_id
;
5792 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
5793 process_constraint (new_constraint (lhs
, *rhsp
));
5803 /* Print out the points-to solution for VAR to FILE. */
5806 dump_solution_for_var (FILE *file
, unsigned int var
)
5808 varinfo_t vi
= get_varinfo (var
);
5812 /* Dump the solution for unified vars anyway, this avoids difficulties
5813 in scanning dumps in the testsuite. */
5814 fprintf (file
, "%s = { ", vi
->name
);
5815 vi
= get_varinfo (find (var
));
5816 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, i
, bi
)
5817 fprintf (file
, "%s ", get_varinfo (i
)->name
);
5818 fprintf (file
, "}");
5820 /* But note when the variable was unified. */
5822 fprintf (file
, " same as %s", vi
->name
);
5824 fprintf (file
, "\n");
5827 /* Print the points-to solution for VAR to stdout. */
5830 debug_solution_for_var (unsigned int var
)
5832 dump_solution_for_var (stdout
, var
);
5835 /* Create varinfo structures for all of the variables in the
5836 function for intraprocedural mode. */
5839 intra_create_variable_infos (void)
5843 /* For each incoming pointer argument arg, create the constraint ARG
5844 = NONLOCAL or a dummy variable if it is a restrict qualified
5845 passed-by-reference argument. */
5846 for (t
= DECL_ARGUMENTS (current_function_decl
); t
; t
= DECL_CHAIN (t
))
5848 varinfo_t p
= get_vi_for_tree (t
);
5850 /* For restrict qualified pointers to objects passed by
5851 reference build a real representative for the pointed-to object.
5852 Treat restrict qualified references the same. */
5853 if (TYPE_RESTRICT (TREE_TYPE (t
))
5854 && ((DECL_BY_REFERENCE (t
) && POINTER_TYPE_P (TREE_TYPE (t
)))
5855 || TREE_CODE (TREE_TYPE (t
)) == REFERENCE_TYPE
)
5856 && !type_contains_placeholder_p (TREE_TYPE (TREE_TYPE (t
))))
5858 struct constraint_expr lhsc
, rhsc
;
5860 tree heapvar
= build_fake_var_decl (TREE_TYPE (TREE_TYPE (t
)));
5861 DECL_EXTERNAL (heapvar
) = 1;
5862 vi
= create_variable_info_for_1 (heapvar
, "PARM_NOALIAS");
5863 insert_vi_for_tree (heapvar
, vi
);
5868 rhsc
.type
= ADDRESSOF
;
5870 process_constraint (new_constraint (lhsc
, rhsc
));
5871 for (; vi
; vi
= vi_next (vi
))
5872 if (vi
->may_have_pointers
)
5874 if (vi
->only_restrict_pointers
)
5875 make_constraint_from_global_restrict (vi
, "GLOBAL_RESTRICT");
5877 make_copy_constraint (vi
, nonlocal_id
);
5882 if (POINTER_TYPE_P (TREE_TYPE (t
))
5883 && TYPE_RESTRICT (TREE_TYPE (t
)))
5884 make_constraint_from_global_restrict (p
, "PARM_RESTRICT");
5887 for (; p
; p
= vi_next (p
))
5889 if (p
->only_restrict_pointers
)
5890 make_constraint_from_global_restrict (p
, "PARM_RESTRICT");
5891 else if (p
->may_have_pointers
)
5892 make_constraint_from (p
, nonlocal_id
);
5897 /* Add a constraint for a result decl that is passed by reference. */
5898 if (DECL_RESULT (cfun
->decl
)
5899 && DECL_BY_REFERENCE (DECL_RESULT (cfun
->decl
)))
5901 varinfo_t p
, result_vi
= get_vi_for_tree (DECL_RESULT (cfun
->decl
));
5903 for (p
= result_vi
; p
; p
= vi_next (p
))
5904 make_constraint_from (p
, nonlocal_id
);
5907 /* Add a constraint for the incoming static chain parameter. */
5908 if (cfun
->static_chain_decl
!= NULL_TREE
)
5910 varinfo_t p
, chain_vi
= get_vi_for_tree (cfun
->static_chain_decl
);
5912 for (p
= chain_vi
; p
; p
= vi_next (p
))
5913 make_constraint_from (p
, nonlocal_id
);
5917 /* Structure used to put solution bitmaps in a hashtable so they can
5918 be shared among variables with the same points-to set. */
5920 typedef struct shared_bitmap_info
5924 } *shared_bitmap_info_t
;
5925 typedef const struct shared_bitmap_info
*const_shared_bitmap_info_t
;
5927 /* Shared_bitmap hashtable helpers. */
5929 struct shared_bitmap_hasher
: typed_free_remove
<shared_bitmap_info
>
5931 typedef shared_bitmap_info value_type
;
5932 typedef shared_bitmap_info compare_type
;
5933 static inline hashval_t
hash (const value_type
*);
5934 static inline bool equal (const value_type
*, const compare_type
*);
5937 /* Hash function for a shared_bitmap_info_t */
5940 shared_bitmap_hasher::hash (const value_type
*bi
)
5942 return bi
->hashcode
;
5945 /* Equality function for two shared_bitmap_info_t's. */
5948 shared_bitmap_hasher::equal (const value_type
*sbi1
, const compare_type
*sbi2
)
5950 return bitmap_equal_p (sbi1
->pt_vars
, sbi2
->pt_vars
);
5953 /* Shared_bitmap hashtable. */
5955 static hash_table
<shared_bitmap_hasher
> shared_bitmap_table
;
5957 /* Lookup a bitmap in the shared bitmap hashtable, and return an already
5958 existing instance if there is one, NULL otherwise. */
5961 shared_bitmap_lookup (bitmap pt_vars
)
5963 shared_bitmap_info
**slot
;
5964 struct shared_bitmap_info sbi
;
5966 sbi
.pt_vars
= pt_vars
;
5967 sbi
.hashcode
= bitmap_hash (pt_vars
);
5969 slot
= shared_bitmap_table
.find_slot_with_hash (&sbi
, sbi
.hashcode
,
5974 return (*slot
)->pt_vars
;
5978 /* Add a bitmap to the shared bitmap hashtable. */
5981 shared_bitmap_add (bitmap pt_vars
)
5983 shared_bitmap_info
**slot
;
5984 shared_bitmap_info_t sbi
= XNEW (struct shared_bitmap_info
);
5986 sbi
->pt_vars
= pt_vars
;
5987 sbi
->hashcode
= bitmap_hash (pt_vars
);
5989 slot
= shared_bitmap_table
.find_slot_with_hash (sbi
, sbi
->hashcode
, INSERT
);
5990 gcc_assert (!*slot
);
5995 /* Set bits in INTO corresponding to the variable uids in solution set FROM. */
5998 set_uids_in_ptset (bitmap into
, bitmap from
, struct pt_solution
*pt
)
6002 varinfo_t escaped_vi
= get_varinfo (find (escaped_id
));
6003 bool everything_escaped
6004 = escaped_vi
->solution
&& bitmap_bit_p (escaped_vi
->solution
, anything_id
);
6006 EXECUTE_IF_SET_IN_BITMAP (from
, 0, i
, bi
)
6008 varinfo_t vi
= get_varinfo (i
);
6010 /* The only artificial variables that are allowed in a may-alias
6011 set are heap variables. */
6012 if (vi
->is_artificial_var
&& !vi
->is_heap_var
)
6015 if (everything_escaped
6016 || (escaped_vi
->solution
6017 && bitmap_bit_p (escaped_vi
->solution
, i
)))
6019 pt
->vars_contains_escaped
= true;
6020 pt
->vars_contains_escaped_heap
= vi
->is_heap_var
;
6023 if (TREE_CODE (vi
->decl
) == VAR_DECL
6024 || TREE_CODE (vi
->decl
) == PARM_DECL
6025 || TREE_CODE (vi
->decl
) == RESULT_DECL
)
6027 /* If we are in IPA mode we will not recompute points-to
6028 sets after inlining so make sure they stay valid. */
6030 && !DECL_PT_UID_SET_P (vi
->decl
))
6031 SET_DECL_PT_UID (vi
->decl
, DECL_UID (vi
->decl
));
6033 /* Add the decl to the points-to set. Note that the points-to
6034 set contains global variables. */
6035 bitmap_set_bit (into
, DECL_PT_UID (vi
->decl
));
6036 if (vi
->is_global_var
)
6037 pt
->vars_contains_nonlocal
= true;
6043 /* Compute the points-to solution *PT for the variable VI. */
6045 static struct pt_solution
6046 find_what_var_points_to (varinfo_t orig_vi
)
6050 bitmap finished_solution
;
6054 struct pt_solution
*pt
;
6056 /* This variable may have been collapsed, let's get the real
6058 vi
= get_varinfo (find (orig_vi
->id
));
6060 /* See if we have already computed the solution and return it. */
6061 slot
= pointer_map_insert (final_solutions
, vi
);
6063 return *(struct pt_solution
*)*slot
;
6065 *slot
= pt
= XOBNEW (&final_solutions_obstack
, struct pt_solution
);
6066 memset (pt
, 0, sizeof (struct pt_solution
));
6068 /* Translate artificial variables into SSA_NAME_PTR_INFO
6070 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, i
, bi
)
6072 varinfo_t vi
= get_varinfo (i
);
6074 if (vi
->is_artificial_var
)
6076 if (vi
->id
== nothing_id
)
6078 else if (vi
->id
== escaped_id
)
6081 pt
->ipa_escaped
= 1;
6085 else if (vi
->id
== nonlocal_id
)
6087 else if (vi
->is_heap_var
)
6088 /* We represent heapvars in the points-to set properly. */
6090 else if (vi
->id
== readonly_id
)
6093 else if (vi
->id
== anything_id
6094 || vi
->id
== integer_id
)
6099 /* Instead of doing extra work, simply do not create
6100 elaborate points-to information for pt_anything pointers. */
6104 /* Share the final set of variables when possible. */
6105 finished_solution
= BITMAP_GGC_ALLOC ();
6106 stats
.points_to_sets_created
++;
6108 set_uids_in_ptset (finished_solution
, vi
->solution
, pt
);
6109 result
= shared_bitmap_lookup (finished_solution
);
6112 shared_bitmap_add (finished_solution
);
6113 pt
->vars
= finished_solution
;
6118 bitmap_clear (finished_solution
);
6124 /* Given a pointer variable P, fill in its points-to set. */
6127 find_what_p_points_to (tree p
)
6129 struct ptr_info_def
*pi
;
6133 /* For parameters, get at the points-to set for the actual parm
6135 if (TREE_CODE (p
) == SSA_NAME
6136 && SSA_NAME_IS_DEFAULT_DEF (p
)
6137 && (TREE_CODE (SSA_NAME_VAR (p
)) == PARM_DECL
6138 || TREE_CODE (SSA_NAME_VAR (p
)) == RESULT_DECL
))
6139 lookup_p
= SSA_NAME_VAR (p
);
6141 vi
= lookup_vi_for_tree (lookup_p
);
6145 pi
= get_ptr_info (p
);
6146 pi
->pt
= find_what_var_points_to (vi
);
6150 /* Query statistics for points-to solutions. */
6153 unsigned HOST_WIDE_INT pt_solution_includes_may_alias
;
6154 unsigned HOST_WIDE_INT pt_solution_includes_no_alias
;
6155 unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias
;
6156 unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias
;
6160 dump_pta_stats (FILE *s
)
6162 fprintf (s
, "\nPTA query stats:\n");
6163 fprintf (s
, " pt_solution_includes: "
6164 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
6165 HOST_WIDE_INT_PRINT_DEC
" queries\n",
6166 pta_stats
.pt_solution_includes_no_alias
,
6167 pta_stats
.pt_solution_includes_no_alias
6168 + pta_stats
.pt_solution_includes_may_alias
);
6169 fprintf (s
, " pt_solutions_intersect: "
6170 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
6171 HOST_WIDE_INT_PRINT_DEC
" queries\n",
6172 pta_stats
.pt_solutions_intersect_no_alias
,
6173 pta_stats
.pt_solutions_intersect_no_alias
6174 + pta_stats
.pt_solutions_intersect_may_alias
);
6178 /* Reset the points-to solution *PT to a conservative default
6179 (point to anything). */
6182 pt_solution_reset (struct pt_solution
*pt
)
6184 memset (pt
, 0, sizeof (struct pt_solution
));
6185 pt
->anything
= true;
6188 /* Set the points-to solution *PT to point only to the variables
6189 in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
6190 global variables and VARS_CONTAINS_RESTRICT specifies whether
6191 it contains restrict tag variables. */
6194 pt_solution_set (struct pt_solution
*pt
, bitmap vars
,
6195 bool vars_contains_nonlocal
)
6197 memset (pt
, 0, sizeof (struct pt_solution
));
6199 pt
->vars_contains_nonlocal
= vars_contains_nonlocal
;
6200 pt
->vars_contains_escaped
6201 = (cfun
->gimple_df
->escaped
.anything
6202 || bitmap_intersect_p (cfun
->gimple_df
->escaped
.vars
, vars
));
6205 /* Set the points-to solution *PT to point only to the variable VAR. */
6208 pt_solution_set_var (struct pt_solution
*pt
, tree var
)
6210 memset (pt
, 0, sizeof (struct pt_solution
));
6211 pt
->vars
= BITMAP_GGC_ALLOC ();
6212 bitmap_set_bit (pt
->vars
, DECL_PT_UID (var
));
6213 pt
->vars_contains_nonlocal
= is_global_var (var
);
6214 pt
->vars_contains_escaped
6215 = (cfun
->gimple_df
->escaped
.anything
6216 || bitmap_bit_p (cfun
->gimple_df
->escaped
.vars
, DECL_PT_UID (var
)));
6219 /* Computes the union of the points-to solutions *DEST and *SRC and
6220 stores the result in *DEST. This changes the points-to bitmap
6221 of *DEST and thus may not be used if that might be shared.
6222 The points-to bitmap of *SRC and *DEST will not be shared after
6223 this function if they were not before. */
6226 pt_solution_ior_into (struct pt_solution
*dest
, struct pt_solution
*src
)
6228 dest
->anything
|= src
->anything
;
6231 pt_solution_reset (dest
);
6235 dest
->nonlocal
|= src
->nonlocal
;
6236 dest
->escaped
|= src
->escaped
;
6237 dest
->ipa_escaped
|= src
->ipa_escaped
;
6238 dest
->null
|= src
->null
;
6239 dest
->vars_contains_nonlocal
|= src
->vars_contains_nonlocal
;
6240 dest
->vars_contains_escaped
|= src
->vars_contains_escaped
;
6241 dest
->vars_contains_escaped_heap
|= src
->vars_contains_escaped_heap
;
6246 dest
->vars
= BITMAP_GGC_ALLOC ();
6247 bitmap_ior_into (dest
->vars
, src
->vars
);
6250 /* Return true if the points-to solution *PT is empty. */
6253 pt_solution_empty_p (struct pt_solution
*pt
)
6260 && !bitmap_empty_p (pt
->vars
))
6263 /* If the solution includes ESCAPED, check if that is empty. */
6265 && !pt_solution_empty_p (&cfun
->gimple_df
->escaped
))
6268 /* If the solution includes ESCAPED, check if that is empty. */
6270 && !pt_solution_empty_p (&ipa_escaped_pt
))
6276 /* Return true if the points-to solution *PT only point to a single var, and
6277 return the var uid in *UID. */
6280 pt_solution_singleton_p (struct pt_solution
*pt
, unsigned *uid
)
6282 if (pt
->anything
|| pt
->nonlocal
|| pt
->escaped
|| pt
->ipa_escaped
6283 || pt
->null
|| pt
->vars
== NULL
6284 || !bitmap_single_bit_set_p (pt
->vars
))
6287 *uid
= bitmap_first_set_bit (pt
->vars
);
6291 /* Return true if the points-to solution *PT includes global memory. */
6294 pt_solution_includes_global (struct pt_solution
*pt
)
6298 || pt
->vars_contains_nonlocal
6299 /* The following is a hack to make the malloc escape hack work.
6300 In reality we'd need different sets for escaped-through-return
6301 and escaped-to-callees and passes would need to be updated. */
6302 || pt
->vars_contains_escaped_heap
)
6305 /* 'escaped' is also a placeholder so we have to look into it. */
6307 return pt_solution_includes_global (&cfun
->gimple_df
->escaped
);
6309 if (pt
->ipa_escaped
)
6310 return pt_solution_includes_global (&ipa_escaped_pt
);
6312 /* ??? This predicate is not correct for the IPA-PTA solution
6313 as we do not properly distinguish between unit escape points
6314 and global variables. */
6315 if (cfun
->gimple_df
->ipa_pta
)
6321 /* Return true if the points-to solution *PT includes the variable
6322 declaration DECL. */
6325 pt_solution_includes_1 (struct pt_solution
*pt
, const_tree decl
)
6331 && is_global_var (decl
))
6335 && bitmap_bit_p (pt
->vars
, DECL_PT_UID (decl
)))
6338 /* If the solution includes ESCAPED, check it. */
6340 && pt_solution_includes_1 (&cfun
->gimple_df
->escaped
, decl
))
6343 /* If the solution includes ESCAPED, check it. */
6345 && pt_solution_includes_1 (&ipa_escaped_pt
, decl
))
6352 pt_solution_includes (struct pt_solution
*pt
, const_tree decl
)
6354 bool res
= pt_solution_includes_1 (pt
, decl
);
6356 ++pta_stats
.pt_solution_includes_may_alias
;
6358 ++pta_stats
.pt_solution_includes_no_alias
;
6362 /* Return true if both points-to solutions PT1 and PT2 have a non-empty
6366 pt_solutions_intersect_1 (struct pt_solution
*pt1
, struct pt_solution
*pt2
)
6368 if (pt1
->anything
|| pt2
->anything
)
6371 /* If either points to unknown global memory and the other points to
6372 any global memory they alias. */
6375 || pt2
->vars_contains_nonlocal
))
6377 && pt1
->vars_contains_nonlocal
))
6380 /* If either points to all escaped memory and the other points to
6381 any escaped memory they alias. */
6384 || pt2
->vars_contains_escaped
))
6386 && pt1
->vars_contains_escaped
))
6389 /* Check the escaped solution if required.
6390 ??? Do we need to check the local against the IPA escaped sets? */
6391 if ((pt1
->ipa_escaped
|| pt2
->ipa_escaped
)
6392 && !pt_solution_empty_p (&ipa_escaped_pt
))
6394 /* If both point to escaped memory and that solution
6395 is not empty they alias. */
6396 if (pt1
->ipa_escaped
&& pt2
->ipa_escaped
)
6399 /* If either points to escaped memory see if the escaped solution
6400 intersects with the other. */
6401 if ((pt1
->ipa_escaped
6402 && pt_solutions_intersect_1 (&ipa_escaped_pt
, pt2
))
6403 || (pt2
->ipa_escaped
6404 && pt_solutions_intersect_1 (&ipa_escaped_pt
, pt1
)))
6408 /* Now both pointers alias if their points-to solution intersects. */
6411 && bitmap_intersect_p (pt1
->vars
, pt2
->vars
));
6415 pt_solutions_intersect (struct pt_solution
*pt1
, struct pt_solution
*pt2
)
6417 bool res
= pt_solutions_intersect_1 (pt1
, pt2
);
6419 ++pta_stats
.pt_solutions_intersect_may_alias
;
6421 ++pta_stats
.pt_solutions_intersect_no_alias
;
6426 /* Dump points-to information to OUTFILE. */
6429 dump_sa_points_to_info (FILE *outfile
)
6433 fprintf (outfile
, "\nPoints-to sets\n\n");
6435 if (dump_flags
& TDF_STATS
)
6437 fprintf (outfile
, "Stats:\n");
6438 fprintf (outfile
, "Total vars: %d\n", stats
.total_vars
);
6439 fprintf (outfile
, "Non-pointer vars: %d\n",
6440 stats
.nonpointer_vars
);
6441 fprintf (outfile
, "Statically unified vars: %d\n",
6442 stats
.unified_vars_static
);
6443 fprintf (outfile
, "Dynamically unified vars: %d\n",
6444 stats
.unified_vars_dynamic
);
6445 fprintf (outfile
, "Iterations: %d\n", stats
.iterations
);
6446 fprintf (outfile
, "Number of edges: %d\n", stats
.num_edges
);
6447 fprintf (outfile
, "Number of implicit edges: %d\n",
6448 stats
.num_implicit_edges
);
6451 for (i
= 1; i
< varmap
.length (); i
++)
6453 varinfo_t vi
= get_varinfo (i
);
6454 if (!vi
->may_have_pointers
)
6456 dump_solution_for_var (outfile
, i
);
6461 /* Debug points-to information to stderr. */
6464 debug_sa_points_to_info (void)
6466 dump_sa_points_to_info (stderr
);
6470 /* Initialize the always-existing constraint variables for NULL
6471 ANYTHING, READONLY, and INTEGER */
6474 init_base_vars (void)
6476 struct constraint_expr lhs
, rhs
;
6477 varinfo_t var_anything
;
6478 varinfo_t var_nothing
;
6479 varinfo_t var_readonly
;
6480 varinfo_t var_escaped
;
6481 varinfo_t var_nonlocal
;
6482 varinfo_t var_storedanything
;
6483 varinfo_t var_integer
;
6485 /* Variable ID zero is reserved and should be NULL. */
6486 varmap
.safe_push (NULL
);
6488 /* Create the NULL variable, used to represent that a variable points
6490 var_nothing
= new_var_info (NULL_TREE
, "NULL");
6491 gcc_assert (var_nothing
->id
== nothing_id
);
6492 var_nothing
->is_artificial_var
= 1;
6493 var_nothing
->offset
= 0;
6494 var_nothing
->size
= ~0;
6495 var_nothing
->fullsize
= ~0;
6496 var_nothing
->is_special_var
= 1;
6497 var_nothing
->may_have_pointers
= 0;
6498 var_nothing
->is_global_var
= 0;
6500 /* Create the ANYTHING variable, used to represent that a variable
6501 points to some unknown piece of memory. */
6502 var_anything
= new_var_info (NULL_TREE
, "ANYTHING");
6503 gcc_assert (var_anything
->id
== anything_id
);
6504 var_anything
->is_artificial_var
= 1;
6505 var_anything
->size
= ~0;
6506 var_anything
->offset
= 0;
6507 var_anything
->fullsize
= ~0;
6508 var_anything
->is_special_var
= 1;
6510 /* Anything points to anything. This makes deref constraints just
6511 work in the presence of linked list and other p = *p type loops,
6512 by saying that *ANYTHING = ANYTHING. */
6514 lhs
.var
= anything_id
;
6516 rhs
.type
= ADDRESSOF
;
6517 rhs
.var
= anything_id
;
6520 /* This specifically does not use process_constraint because
6521 process_constraint ignores all anything = anything constraints, since all
6522 but this one are redundant. */
6523 constraints
.safe_push (new_constraint (lhs
, rhs
));
6525 /* Create the READONLY variable, used to represent that a variable
6526 points to readonly memory. */
6527 var_readonly
= new_var_info (NULL_TREE
, "READONLY");
6528 gcc_assert (var_readonly
->id
== readonly_id
);
6529 var_readonly
->is_artificial_var
= 1;
6530 var_readonly
->offset
= 0;
6531 var_readonly
->size
= ~0;
6532 var_readonly
->fullsize
= ~0;
6533 var_readonly
->is_special_var
= 1;
6535 /* readonly memory points to anything, in order to make deref
6536 easier. In reality, it points to anything the particular
6537 readonly variable can point to, but we don't track this
6540 lhs
.var
= readonly_id
;
6542 rhs
.type
= ADDRESSOF
;
6543 rhs
.var
= readonly_id
; /* FIXME */
6545 process_constraint (new_constraint (lhs
, rhs
));
6547 /* Create the ESCAPED variable, used to represent the set of escaped
6549 var_escaped
= new_var_info (NULL_TREE
, "ESCAPED");
6550 gcc_assert (var_escaped
->id
== escaped_id
);
6551 var_escaped
->is_artificial_var
= 1;
6552 var_escaped
->offset
= 0;
6553 var_escaped
->size
= ~0;
6554 var_escaped
->fullsize
= ~0;
6555 var_escaped
->is_special_var
= 0;
6557 /* Create the NONLOCAL variable, used to represent the set of nonlocal
6559 var_nonlocal
= new_var_info (NULL_TREE
, "NONLOCAL");
6560 gcc_assert (var_nonlocal
->id
== nonlocal_id
);
6561 var_nonlocal
->is_artificial_var
= 1;
6562 var_nonlocal
->offset
= 0;
6563 var_nonlocal
->size
= ~0;
6564 var_nonlocal
->fullsize
= ~0;
6565 var_nonlocal
->is_special_var
= 1;
6567 /* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
6569 lhs
.var
= escaped_id
;
6572 rhs
.var
= escaped_id
;
6574 process_constraint (new_constraint (lhs
, rhs
));
6576 /* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
6577 whole variable escapes. */
6579 lhs
.var
= escaped_id
;
6582 rhs
.var
= escaped_id
;
6583 rhs
.offset
= UNKNOWN_OFFSET
;
6584 process_constraint (new_constraint (lhs
, rhs
));
6586 /* *ESCAPED = NONLOCAL. This is true because we have to assume
6587 everything pointed to by escaped points to what global memory can
6590 lhs
.var
= escaped_id
;
6593 rhs
.var
= nonlocal_id
;
6595 process_constraint (new_constraint (lhs
, rhs
));
6597 /* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
6598 global memory may point to global memory and escaped memory. */
6600 lhs
.var
= nonlocal_id
;
6602 rhs
.type
= ADDRESSOF
;
6603 rhs
.var
= nonlocal_id
;
6605 process_constraint (new_constraint (lhs
, rhs
));
6606 rhs
.type
= ADDRESSOF
;
6607 rhs
.var
= escaped_id
;
6609 process_constraint (new_constraint (lhs
, rhs
));
6611 /* Create the STOREDANYTHING variable, used to represent the set of
6612 variables stored to *ANYTHING. */
6613 var_storedanything
= new_var_info (NULL_TREE
, "STOREDANYTHING");
6614 gcc_assert (var_storedanything
->id
== storedanything_id
);
6615 var_storedanything
->is_artificial_var
= 1;
6616 var_storedanything
->offset
= 0;
6617 var_storedanything
->size
= ~0;
6618 var_storedanything
->fullsize
= ~0;
6619 var_storedanything
->is_special_var
= 0;
6621 /* Create the INTEGER variable, used to represent that a variable points
6622 to what an INTEGER "points to". */
6623 var_integer
= new_var_info (NULL_TREE
, "INTEGER");
6624 gcc_assert (var_integer
->id
== integer_id
);
6625 var_integer
->is_artificial_var
= 1;
6626 var_integer
->size
= ~0;
6627 var_integer
->fullsize
= ~0;
6628 var_integer
->offset
= 0;
6629 var_integer
->is_special_var
= 1;
6631 /* INTEGER = ANYTHING, because we don't know where a dereference of
6632 a random integer will point to. */
6634 lhs
.var
= integer_id
;
6636 rhs
.type
= ADDRESSOF
;
6637 rhs
.var
= anything_id
;
6639 process_constraint (new_constraint (lhs
, rhs
));
6642 /* Initialize things necessary to perform PTA */
6645 init_alias_vars (void)
6647 use_field_sensitive
= (MAX_FIELDS_FOR_FIELD_SENSITIVE
> 1);
6649 bitmap_obstack_initialize (&pta_obstack
);
6650 bitmap_obstack_initialize (&oldpta_obstack
);
6651 bitmap_obstack_initialize (&predbitmap_obstack
);
6653 constraint_pool
= create_alloc_pool ("Constraint pool",
6654 sizeof (struct constraint
), 30);
6655 variable_info_pool
= create_alloc_pool ("Variable info pool",
6656 sizeof (struct variable_info
), 30);
6657 constraints
.create (8);
6659 vi_for_tree
= pointer_map_create ();
6660 call_stmt_vars
= pointer_map_create ();
6662 memset (&stats
, 0, sizeof (stats
));
6663 shared_bitmap_table
.create (511);
6666 gcc_obstack_init (&fake_var_decl_obstack
);
6668 final_solutions
= pointer_map_create ();
6669 gcc_obstack_init (&final_solutions_obstack
);
6672 /* Remove the REF and ADDRESS edges from GRAPH, as well as all the
6673 predecessor edges. */
6676 remove_preds_and_fake_succs (constraint_graph_t graph
)
6680 /* Clear the implicit ref and address nodes from the successor
6682 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
6684 if (graph
->succs
[i
])
6685 bitmap_clear_range (graph
->succs
[i
], FIRST_REF_NODE
,
6686 FIRST_REF_NODE
* 2);
6689 /* Free the successor list for the non-ref nodes. */
6690 for (i
= FIRST_REF_NODE
+ 1; i
< graph
->size
; i
++)
6692 if (graph
->succs
[i
])
6693 BITMAP_FREE (graph
->succs
[i
]);
6696 /* Now reallocate the size of the successor list as, and blow away
6697 the predecessor bitmaps. */
6698 graph
->size
= varmap
.length ();
6699 graph
->succs
= XRESIZEVEC (bitmap
, graph
->succs
, graph
->size
);
6701 free (graph
->implicit_preds
);
6702 graph
->implicit_preds
= NULL
;
6703 free (graph
->preds
);
6704 graph
->preds
= NULL
;
6705 bitmap_obstack_release (&predbitmap_obstack
);
6708 /* Solve the constraint set. */
6711 solve_constraints (void)
6713 struct scc_info
*si
;
6717 "\nCollapsing static cycles and doing variable "
6720 init_graph (varmap
.length () * 2);
6723 fprintf (dump_file
, "Building predecessor graph\n");
6724 build_pred_graph ();
6727 fprintf (dump_file
, "Detecting pointer and location "
6729 si
= perform_var_substitution (graph
);
6732 fprintf (dump_file
, "Rewriting constraints and unifying "
6734 rewrite_constraints (graph
, si
);
6736 build_succ_graph ();
6738 free_var_substitution_info (si
);
6740 /* Attach complex constraints to graph nodes. */
6741 move_complex_constraints (graph
);
6744 fprintf (dump_file
, "Uniting pointer but not location equivalent "
6746 unite_pointer_equivalences (graph
);
6749 fprintf (dump_file
, "Finding indirect cycles\n");
6750 find_indirect_cycles (graph
);
6752 /* Implicit nodes and predecessors are no longer necessary at this
6754 remove_preds_and_fake_succs (graph
);
6756 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
6758 fprintf (dump_file
, "\n\n// The constraint graph before solve-graph "
6759 "in dot format:\n");
6760 dump_constraint_graph (dump_file
);
6761 fprintf (dump_file
, "\n\n");
6765 fprintf (dump_file
, "Solving graph\n");
6767 solve_graph (graph
);
6769 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
6771 fprintf (dump_file
, "\n\n// The constraint graph after solve-graph "
6772 "in dot format:\n");
6773 dump_constraint_graph (dump_file
);
6774 fprintf (dump_file
, "\n\n");
6778 dump_sa_points_to_info (dump_file
);
6781 /* Create points-to sets for the current function. See the comments
6782 at the start of the file for an algorithmic overview. */
6785 compute_points_to_sets (void)
6791 timevar_push (TV_TREE_PTA
);
6795 intra_create_variable_infos ();
6797 /* Now walk all statements and build the constraint set. */
6800 gimple_stmt_iterator gsi
;
6802 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6804 gimple phi
= gsi_stmt (gsi
);
6806 if (! virtual_operand_p (gimple_phi_result (phi
)))
6807 find_func_aliases (phi
);
6810 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6812 gimple stmt
= gsi_stmt (gsi
);
6814 find_func_aliases (stmt
);
6820 fprintf (dump_file
, "Points-to analysis\n\nConstraints:\n\n");
6821 dump_constraints (dump_file
, 0);
6824 /* From the constraints compute the points-to sets. */
6825 solve_constraints ();
6827 /* Compute the points-to set for ESCAPED used for call-clobber analysis. */
6828 cfun
->gimple_df
->escaped
= find_what_var_points_to (get_varinfo (escaped_id
));
6830 /* Make sure the ESCAPED solution (which is used as placeholder in
6831 other solutions) does not reference itself. This simplifies
6832 points-to solution queries. */
6833 cfun
->gimple_df
->escaped
.escaped
= 0;
6835 /* Compute the points-to sets for pointer SSA_NAMEs. */
6836 for (i
= 0; i
< num_ssa_names
; ++i
)
6838 tree ptr
= ssa_name (i
);
6840 && POINTER_TYPE_P (TREE_TYPE (ptr
)))
6841 find_what_p_points_to (ptr
);
6844 /* Compute the call-used/clobbered sets. */
6847 gimple_stmt_iterator gsi
;
6849 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6851 gimple stmt
= gsi_stmt (gsi
);
6852 struct pt_solution
*pt
;
6853 if (!is_gimple_call (stmt
))
6856 pt
= gimple_call_use_set (stmt
);
6857 if (gimple_call_flags (stmt
) & ECF_CONST
)
6858 memset (pt
, 0, sizeof (struct pt_solution
));
6859 else if ((vi
= lookup_call_use_vi (stmt
)) != NULL
)
6861 *pt
= find_what_var_points_to (vi
);
6862 /* Escaped (and thus nonlocal) variables are always
6863 implicitly used by calls. */
6864 /* ??? ESCAPED can be empty even though NONLOCAL
6871 /* If there is nothing special about this call then
6872 we have made everything that is used also escape. */
6873 *pt
= cfun
->gimple_df
->escaped
;
6877 pt
= gimple_call_clobber_set (stmt
);
6878 if (gimple_call_flags (stmt
) & (ECF_CONST
|ECF_PURE
|ECF_NOVOPS
))
6879 memset (pt
, 0, sizeof (struct pt_solution
));
6880 else if ((vi
= lookup_call_clobber_vi (stmt
)) != NULL
)
6882 *pt
= find_what_var_points_to (vi
);
6883 /* Escaped (and thus nonlocal) variables are always
6884 implicitly clobbered by calls. */
6885 /* ??? ESCAPED can be empty even though NONLOCAL
6892 /* If there is nothing special about this call then
6893 we have made everything that is used also escape. */
6894 *pt
= cfun
->gimple_df
->escaped
;
6900 timevar_pop (TV_TREE_PTA
);
6904 /* Delete created points-to sets. */
6907 delete_points_to_sets (void)
6911 shared_bitmap_table
.dispose ();
6912 if (dump_file
&& (dump_flags
& TDF_STATS
))
6913 fprintf (dump_file
, "Points to sets created:%d\n",
6914 stats
.points_to_sets_created
);
6916 pointer_map_destroy (vi_for_tree
);
6917 pointer_map_destroy (call_stmt_vars
);
6918 bitmap_obstack_release (&pta_obstack
);
6919 constraints
.release ();
6921 for (i
= 0; i
< graph
->size
; i
++)
6922 graph
->complex[i
].release ();
6923 free (graph
->complex);
6926 free (graph
->succs
);
6928 free (graph
->pe_rep
);
6929 free (graph
->indirect_cycles
);
6933 free_alloc_pool (variable_info_pool
);
6934 free_alloc_pool (constraint_pool
);
6936 obstack_free (&fake_var_decl_obstack
, NULL
);
6938 pointer_map_destroy (final_solutions
);
6939 obstack_free (&final_solutions_obstack
, NULL
);
6943 /* Compute points-to information for every SSA_NAME pointer in the
6944 current function and compute the transitive closure of escaped
6945 variables to re-initialize the call-clobber states of local variables. */
6948 compute_may_aliases (void)
6950 if (cfun
->gimple_df
->ipa_pta
)
6954 fprintf (dump_file
, "\nNot re-computing points-to information "
6955 "because IPA points-to information is available.\n\n");
6957 /* But still dump what we have remaining it. */
6958 dump_alias_info (dump_file
);
6964 /* For each pointer P_i, determine the sets of variables that P_i may
6965 point-to. Compute the reachability set of escaped and call-used
6967 compute_points_to_sets ();
6969 /* Debugging dumps. */
6971 dump_alias_info (dump_file
);
6973 /* Deallocate memory used by aliasing data structures and the internal
6974 points-to solution. */
6975 delete_points_to_sets ();
6977 gcc_assert (!need_ssa_update_p (cfun
));
6983 gate_tree_pta (void)
6985 return flag_tree_pta
;
6988 /* A dummy pass to cause points-to information to be computed via
6989 TODO_rebuild_alias. */
6993 const pass_data pass_data_build_alias
=
6995 GIMPLE_PASS
, /* type */
6997 OPTGROUP_NONE
, /* optinfo_flags */
6998 true, /* has_gate */
6999 false, /* has_execute */
7000 TV_NONE
, /* tv_id */
7001 ( PROP_cfg
| PROP_ssa
), /* properties_required */
7002 0, /* properties_provided */
7003 0, /* properties_destroyed */
7004 0, /* todo_flags_start */
7005 TODO_rebuild_alias
, /* todo_flags_finish */
7008 class pass_build_alias
: public gimple_opt_pass
7011 pass_build_alias (gcc::context
*ctxt
)
7012 : gimple_opt_pass (pass_data_build_alias
, ctxt
)
7015 /* opt_pass methods: */
7016 bool gate () { return gate_tree_pta (); }
7018 }; // class pass_build_alias
7023 make_pass_build_alias (gcc::context
*ctxt
)
7025 return new pass_build_alias (ctxt
);
7028 /* A dummy pass to cause points-to information to be computed via
7029 TODO_rebuild_alias. */
7033 const pass_data pass_data_build_ealias
=
7035 GIMPLE_PASS
, /* type */
7036 "ealias", /* name */
7037 OPTGROUP_NONE
, /* optinfo_flags */
7038 true, /* has_gate */
7039 false, /* has_execute */
7040 TV_NONE
, /* tv_id */
7041 ( PROP_cfg
| PROP_ssa
), /* properties_required */
7042 0, /* properties_provided */
7043 0, /* properties_destroyed */
7044 0, /* todo_flags_start */
7045 TODO_rebuild_alias
, /* todo_flags_finish */
7048 class pass_build_ealias
: public gimple_opt_pass
7051 pass_build_ealias (gcc::context
*ctxt
)
7052 : gimple_opt_pass (pass_data_build_ealias
, ctxt
)
7055 /* opt_pass methods: */
7056 bool gate () { return gate_tree_pta (); }
7058 }; // class pass_build_ealias
7063 make_pass_build_ealias (gcc::context
*ctxt
)
7065 return new pass_build_ealias (ctxt
);
7069 /* Return true if we should execute IPA PTA. */
7075 /* Don't bother doing anything if the program has errors. */
7079 /* IPA PTA solutions for ESCAPED. */
7080 struct pt_solution ipa_escaped_pt
7081 = { true, false, false, false, false, false, false, false, NULL
};
7083 /* Associate node with varinfo DATA. Worker for
7084 cgraph_for_node_and_aliases. */
7086 associate_varinfo_to_alias (struct cgraph_node
*node
, void *data
)
7088 if ((node
->alias
|| node
->thunk
.thunk_p
)
7090 insert_vi_for_tree (node
->decl
, (varinfo_t
)data
);
7094 /* Execute the driver for IPA PTA. */
7096 ipa_pta_execute (void)
7098 struct cgraph_node
*node
;
7099 struct varpool_node
*var
;
7106 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7108 dump_symtab (dump_file
);
7109 fprintf (dump_file
, "\n");
7112 /* Build the constraints. */
7113 FOR_EACH_DEFINED_FUNCTION (node
)
7116 /* Nodes without a body are not interesting. Especially do not
7117 visit clones at this point for now - we get duplicate decls
7118 there for inline clones at least. */
7119 if (!cgraph_function_with_gimple_body_p (node
) || node
->clone_of
)
7121 cgraph_get_body (node
);
7123 gcc_assert (!node
->clone_of
);
7125 vi
= create_function_info_for (node
->decl
,
7126 alias_get_name (node
->decl
));
7127 cgraph_for_node_and_aliases (node
, associate_varinfo_to_alias
, vi
, true);
7130 /* Create constraints for global variables and their initializers. */
7131 FOR_EACH_VARIABLE (var
)
7133 if (var
->alias
&& var
->analyzed
)
7136 get_vi_for_tree (var
->decl
);
7142 "Generating constraints for global initializers\n\n");
7143 dump_constraints (dump_file
, 0);
7144 fprintf (dump_file
, "\n");
7146 from
= constraints
.length ();
7148 FOR_EACH_DEFINED_FUNCTION (node
)
7150 struct function
*func
;
7153 /* Nodes without a body are not interesting. */
7154 if (!cgraph_function_with_gimple_body_p (node
) || node
->clone_of
)
7160 "Generating constraints for %s", cgraph_node_name (node
));
7161 if (DECL_ASSEMBLER_NAME_SET_P (node
->decl
))
7162 fprintf (dump_file
, " (%s)",
7164 (DECL_ASSEMBLER_NAME (node
->decl
)));
7165 fprintf (dump_file
, "\n");
7168 func
= DECL_STRUCT_FUNCTION (node
->decl
);
7171 /* For externally visible or attribute used annotated functions use
7172 local constraints for their arguments.
7173 For local functions we see all callers and thus do not need initial
7174 constraints for parameters. */
7175 if (node
->used_from_other_partition
7176 || node
->externally_visible
7177 || node
->force_output
)
7179 intra_create_variable_infos ();
7181 /* We also need to make function return values escape. Nothing
7182 escapes by returning from main though. */
7183 if (!MAIN_NAME_P (DECL_NAME (node
->decl
)))
7186 fi
= lookup_vi_for_tree (node
->decl
);
7187 rvi
= first_vi_for_offset (fi
, fi_result
);
7188 if (rvi
&& rvi
->offset
== fi_result
)
7190 struct constraint_expr includes
;
7191 struct constraint_expr var
;
7192 includes
.var
= escaped_id
;
7193 includes
.offset
= 0;
7194 includes
.type
= SCALAR
;
7198 process_constraint (new_constraint (includes
, var
));
7203 /* Build constriants for the function body. */
7204 FOR_EACH_BB_FN (bb
, func
)
7206 gimple_stmt_iterator gsi
;
7208 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
7211 gimple phi
= gsi_stmt (gsi
);
7213 if (! virtual_operand_p (gimple_phi_result (phi
)))
7214 find_func_aliases (phi
);
7217 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
7219 gimple stmt
= gsi_stmt (gsi
);
7221 find_func_aliases (stmt
);
7222 find_func_clobbers (stmt
);
7230 fprintf (dump_file
, "\n");
7231 dump_constraints (dump_file
, from
);
7232 fprintf (dump_file
, "\n");
7234 from
= constraints
.length ();
7237 /* From the constraints compute the points-to sets. */
7238 solve_constraints ();
7240 /* Compute the global points-to sets for ESCAPED.
7241 ??? Note that the computed escape set is not correct
7242 for the whole unit as we fail to consider graph edges to
7243 externally visible functions. */
7244 ipa_escaped_pt
= find_what_var_points_to (get_varinfo (escaped_id
));
7246 /* Make sure the ESCAPED solution (which is used as placeholder in
7247 other solutions) does not reference itself. This simplifies
7248 points-to solution queries. */
7249 ipa_escaped_pt
.ipa_escaped
= 0;
7251 /* Assign the points-to sets to the SSA names in the unit. */
7252 FOR_EACH_DEFINED_FUNCTION (node
)
7255 struct function
*fn
;
7259 struct pt_solution uses
, clobbers
;
7260 struct cgraph_edge
*e
;
7262 /* Nodes without a body are not interesting. */
7263 if (!cgraph_function_with_gimple_body_p (node
) || node
->clone_of
)
7266 fn
= DECL_STRUCT_FUNCTION (node
->decl
);
7268 /* Compute the points-to sets for pointer SSA_NAMEs. */
7269 FOR_EACH_VEC_ELT (*fn
->gimple_df
->ssa_names
, i
, ptr
)
7272 && POINTER_TYPE_P (TREE_TYPE (ptr
)))
7273 find_what_p_points_to (ptr
);
7276 /* Compute the call-use and call-clobber sets for all direct calls. */
7277 fi
= lookup_vi_for_tree (node
->decl
);
7278 gcc_assert (fi
->is_fn_info
);
7280 = find_what_var_points_to (first_vi_for_offset (fi
, fi_clobbers
));
7281 uses
= find_what_var_points_to (first_vi_for_offset (fi
, fi_uses
));
7282 for (e
= node
->callers
; e
; e
= e
->next_caller
)
7287 *gimple_call_clobber_set (e
->call_stmt
) = clobbers
;
7288 *gimple_call_use_set (e
->call_stmt
) = uses
;
7291 /* Compute the call-use and call-clobber sets for indirect calls
7292 and calls to external functions. */
7293 FOR_EACH_BB_FN (bb
, fn
)
7295 gimple_stmt_iterator gsi
;
7297 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
7299 gimple stmt
= gsi_stmt (gsi
);
7300 struct pt_solution
*pt
;
7304 if (!is_gimple_call (stmt
))
7307 /* Handle direct calls to external functions. */
7308 decl
= gimple_call_fndecl (stmt
);
7310 && (!(fi
= lookup_vi_for_tree (decl
))
7311 || !fi
->is_fn_info
))
7313 pt
= gimple_call_use_set (stmt
);
7314 if (gimple_call_flags (stmt
) & ECF_CONST
)
7315 memset (pt
, 0, sizeof (struct pt_solution
));
7316 else if ((vi
= lookup_call_use_vi (stmt
)) != NULL
)
7318 *pt
= find_what_var_points_to (vi
);
7319 /* Escaped (and thus nonlocal) variables are always
7320 implicitly used by calls. */
7321 /* ??? ESCAPED can be empty even though NONLOCAL
7324 pt
->ipa_escaped
= 1;
7328 /* If there is nothing special about this call then
7329 we have made everything that is used also escape. */
7330 *pt
= ipa_escaped_pt
;
7334 pt
= gimple_call_clobber_set (stmt
);
7335 if (gimple_call_flags (stmt
) & (ECF_CONST
|ECF_PURE
|ECF_NOVOPS
))
7336 memset (pt
, 0, sizeof (struct pt_solution
));
7337 else if ((vi
= lookup_call_clobber_vi (stmt
)) != NULL
)
7339 *pt
= find_what_var_points_to (vi
);
7340 /* Escaped (and thus nonlocal) variables are always
7341 implicitly clobbered by calls. */
7342 /* ??? ESCAPED can be empty even though NONLOCAL
7345 pt
->ipa_escaped
= 1;
7349 /* If there is nothing special about this call then
7350 we have made everything that is used also escape. */
7351 *pt
= ipa_escaped_pt
;
7356 /* Handle indirect calls. */
7358 && (fi
= get_fi_for_callee (stmt
)))
7360 /* We need to accumulate all clobbers/uses of all possible
7362 fi
= get_varinfo (find (fi
->id
));
7363 /* If we cannot constrain the set of functions we'll end up
7364 calling we end up using/clobbering everything. */
7365 if (bitmap_bit_p (fi
->solution
, anything_id
)
7366 || bitmap_bit_p (fi
->solution
, nonlocal_id
)
7367 || bitmap_bit_p (fi
->solution
, escaped_id
))
7369 pt_solution_reset (gimple_call_clobber_set (stmt
));
7370 pt_solution_reset (gimple_call_use_set (stmt
));
7376 struct pt_solution
*uses
, *clobbers
;
7378 uses
= gimple_call_use_set (stmt
);
7379 clobbers
= gimple_call_clobber_set (stmt
);
7380 memset (uses
, 0, sizeof (struct pt_solution
));
7381 memset (clobbers
, 0, sizeof (struct pt_solution
));
7382 EXECUTE_IF_SET_IN_BITMAP (fi
->solution
, 0, i
, bi
)
7384 struct pt_solution sol
;
7386 vi
= get_varinfo (i
);
7387 if (!vi
->is_fn_info
)
7389 /* ??? We could be more precise here? */
7391 uses
->ipa_escaped
= 1;
7392 clobbers
->nonlocal
= 1;
7393 clobbers
->ipa_escaped
= 1;
7397 if (!uses
->anything
)
7399 sol
= find_what_var_points_to
7400 (first_vi_for_offset (vi
, fi_uses
));
7401 pt_solution_ior_into (uses
, &sol
);
7403 if (!clobbers
->anything
)
7405 sol
= find_what_var_points_to
7406 (first_vi_for_offset (vi
, fi_clobbers
));
7407 pt_solution_ior_into (clobbers
, &sol
);
7415 fn
->gimple_df
->ipa_pta
= true;
7418 delete_points_to_sets ();
7427 const pass_data pass_data_ipa_pta
=
7429 SIMPLE_IPA_PASS
, /* type */
7431 OPTGROUP_NONE
, /* optinfo_flags */
7432 true, /* has_gate */
7433 true, /* has_execute */
7434 TV_IPA_PTA
, /* tv_id */
7435 0, /* properties_required */
7436 0, /* properties_provided */
7437 0, /* properties_destroyed */
7438 0, /* todo_flags_start */
7439 0, /* todo_flags_finish */
7442 class pass_ipa_pta
: public simple_ipa_opt_pass
7445 pass_ipa_pta (gcc::context
*ctxt
)
7446 : simple_ipa_opt_pass (pass_data_ipa_pta
, ctxt
)
7449 /* opt_pass methods: */
7450 bool gate () { return gate_ipa_pta (); }
7451 unsigned int execute () { return ipa_pta_execute (); }
7453 }; // class pass_ipa_pta
7457 simple_ipa_opt_pass
*
7458 make_pass_ipa_pta (gcc::context
*ctxt
)
7460 return new pass_ipa_pta (ctxt
);