1 /* Tree based points-to analysis
2 Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
3 Free Software Foundation, Inc.
4 Contributed by Daniel Berlin <dberlin@dberlin.org>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
30 #include "basic-block.h"
33 #include "tree-flow.h"
34 #include "tree-inline.h"
35 #include "diagnostic-core.h"
40 #include "tree-pass.h"
42 #include "alloc-pool.h"
43 #include "splay-tree.h"
47 #include "pointer-set.h"
49 /* The idea behind this analyzer is to generate set constraints from the
50 program, then solve the resulting constraints in order to generate the
53 Set constraints are a way of modeling program analysis problems that
54 involve sets. They consist of an inclusion constraint language,
55 describing the variables (each variable is a set) and operations that
56 are involved on the variables, and a set of rules that derive facts
57 from these operations. To solve a system of set constraints, you derive
58 all possible facts under the rules, which gives you the correct sets
61 See "Efficient Field-sensitive pointer analysis for C" by "David
62 J. Pearce and Paul H. J. Kelly and Chris Hankin, at
63 http://citeseer.ist.psu.edu/pearce04efficient.html
65 Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
66 of C Code in a Second" by ""Nevin Heintze and Olivier Tardieu" at
67 http://citeseer.ist.psu.edu/heintze01ultrafast.html
69 There are three types of real constraint expressions, DEREF,
70 ADDRESSOF, and SCALAR. Each constraint expression consists
71 of a constraint type, a variable, and an offset.
73 SCALAR is a constraint expression type used to represent x, whether
74 it appears on the LHS or the RHS of a statement.
75 DEREF is a constraint expression type used to represent *x, whether
76 it appears on the LHS or the RHS of a statement.
77 ADDRESSOF is a constraint expression used to represent &x, whether
78 it appears on the LHS or the RHS of a statement.
80 Each pointer variable in the program is assigned an integer id, and
81 each field of a structure variable is assigned an integer id as well.
83 Structure variables are linked to their list of fields through a "next
84 field" in each variable that points to the next field in offset
86 Each variable for a structure field has
88 1. "size", that tells the size in bits of that field.
89 2. "fullsize, that tells the size in bits of the entire structure.
90 3. "offset", that tells the offset in bits from the beginning of the
91 structure to this field.
103 foo.a -> id 1, size 32, offset 0, fullsize 64, next foo.b
104 foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
105 bar -> id 3, size 32, offset 0, fullsize 32, next NULL
108 In order to solve the system of set constraints, the following is
111 1. Each constraint variable x has a solution set associated with it,
114 2. Constraints are separated into direct, copy, and complex.
115 Direct constraints are ADDRESSOF constraints that require no extra
116 processing, such as P = &Q
117 Copy constraints are those of the form P = Q.
118 Complex constraints are all the constraints involving dereferences
119 and offsets (including offsetted copies).
121 3. All direct constraints of the form P = &Q are processed, such
122 that Q is added to Sol(P)
124 4. All complex constraints for a given constraint variable are stored in a
125 linked list attached to that variable's node.
127 5. A directed graph is built out of the copy constraints. Each
128 constraint variable is a node in the graph, and an edge from
129 Q to P is added for each copy constraint of the form P = Q
131 6. The graph is then walked, and solution sets are
132 propagated along the copy edges, such that an edge from Q to P
133 causes Sol(P) <- Sol(P) union Sol(Q).
135 7. As we visit each node, all complex constraints associated with
136 that node are processed by adding appropriate copy edges to the graph, or the
137 appropriate variables to the solution set.
139 8. The process of walking the graph is iterated until no solution
142 Prior to walking the graph in steps 6 and 7, We perform static
143 cycle elimination on the constraint graph, as well
144 as off-line variable substitution.
146 TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
147 on and turned into anything), but isn't. You can just see what offset
148 inside the pointed-to struct it's going to access.
150 TODO: Constant bounded arrays can be handled as if they were structs of the
151 same number of elements.
153 TODO: Modeling heap and incoming pointers becomes much better if we
154 add fields to them as we discover them, which we could do.
156 TODO: We could handle unions, but to be honest, it's probably not
157 worth the pain or slowdown. */
159 /* IPA-PTA optimizations possible.
161 When the indirect function called is ANYTHING we can add disambiguation
162 based on the function signatures (or simply the parameter count which
163 is the varinfo size). We also do not need to consider functions that
164 do not have their address taken.
166 The is_global_var bit which marks escape points is overly conservative
167 in IPA mode. Split it to is_escape_point and is_global_var - only
168 externally visible globals are escape points in IPA mode. This is
169 also needed to fix the pt_solution_includes_global predicate
170 (and thus ptr_deref_may_alias_global_p).
172 The way we introduce DECL_PT_UID to avoid fixing up all points-to
173 sets in the translation unit when we copy a DECL during inlining
174 pessimizes precision. The advantage is that the DECL_PT_UID keeps
175 compile-time and memory usage overhead low - the points-to sets
176 do not grow or get unshared as they would during a fixup phase.
177 An alternative solution is to delay IPA PTA until after all
178 inlining transformations have been applied.
180 The way we propagate clobber/use information isn't optimized.
181 It should use a new complex constraint that properly filters
182 out local variables of the callee (though that would make
183 the sets invalid after inlining). OTOH we might as well
184 admit defeat to WHOPR and simply do all the clobber/use analysis
185 and propagation after PTA finished but before we threw away
186 points-to information for memory variables. WHOPR and PTA
187 do not play along well anyway - the whole constraint solving
188 would need to be done in WPA phase and it will be very interesting
189 to apply the results to local SSA names during LTRANS phase.
191 We probably should compute a per-function unit-ESCAPE solution
192 propagating it simply like the clobber / uses solutions. The
193 solution can go alongside the non-IPA espaced solution and be
194 used to query which vars escape the unit through a function.
196 We never put function decls in points-to sets so we do not
197 keep the set of called functions for indirect calls.
199 And probably more. */
201 static bool use_field_sensitive
= true;
202 static int in_ipa_mode
= 0;
204 /* Used for predecessor bitmaps. */
205 static bitmap_obstack predbitmap_obstack
;
207 /* Used for points-to sets. */
208 static bitmap_obstack pta_obstack
;
210 /* Used for oldsolution members of variables. */
211 static bitmap_obstack oldpta_obstack
;
213 /* Used for per-solver-iteration bitmaps. */
214 static bitmap_obstack iteration_obstack
;
216 static unsigned int create_variable_info_for (tree
, const char *);
217 typedef struct constraint_graph
*constraint_graph_t
;
218 static void unify_nodes (constraint_graph_t
, unsigned int, unsigned int, bool);
221 typedef struct constraint
*constraint_t
;
223 DEF_VEC_P(constraint_t
);
224 DEF_VEC_ALLOC_P(constraint_t
,heap
);
226 #define EXECUTE_IF_IN_NONNULL_BITMAP(a, b, c, d) \
228 EXECUTE_IF_SET_IN_BITMAP (a, b, c, d)
230 static struct constraint_stats
232 unsigned int total_vars
;
233 unsigned int nonpointer_vars
;
234 unsigned int unified_vars_static
;
235 unsigned int unified_vars_dynamic
;
236 unsigned int iterations
;
237 unsigned int num_edges
;
238 unsigned int num_implicit_edges
;
239 unsigned int points_to_sets_created
;
244 /* ID of this variable */
247 /* True if this is a variable created by the constraint analysis, such as
248 heap variables and constraints we had to break up. */
249 unsigned int is_artificial_var
: 1;
251 /* True if this is a special variable whose solution set should not be
253 unsigned int is_special_var
: 1;
255 /* True for variables whose size is not known or variable. */
256 unsigned int is_unknown_size_var
: 1;
258 /* True for (sub-)fields that represent a whole variable. */
259 unsigned int is_full_var
: 1;
261 /* True if this is a heap variable. */
262 unsigned int is_heap_var
: 1;
264 /* True if this is a variable tracking a restrict pointer source. */
265 unsigned int is_restrict_var
: 1;
267 /* True if this field may contain pointers. */
268 unsigned int may_have_pointers
: 1;
270 /* True if this field has only restrict qualified pointers. */
271 unsigned int only_restrict_pointers
: 1;
273 /* True if this represents a global variable. */
274 unsigned int is_global_var
: 1;
276 /* True if this represents a IPA function info. */
277 unsigned int is_fn_info
: 1;
279 /* A link to the variable for the next field in this structure. */
280 struct variable_info
*next
;
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
);
310 /* Pool of variable info structures. */
311 static alloc_pool variable_info_pool
;
313 DEF_VEC_P(varinfo_t
);
315 DEF_VEC_ALLOC_P(varinfo_t
, heap
);
317 /* Table of variable info structures for constraint variables.
318 Indexed directly by variable info id. */
319 static VEC(varinfo_t
,heap
) *varmap
;
321 /* Return the varmap element N */
323 static inline varinfo_t
324 get_varinfo (unsigned int n
)
326 return VEC_index (varinfo_t
, varmap
, n
);
329 /* Static IDs for the special variables. */
330 enum { nothing_id
= 0, anything_id
= 1, readonly_id
= 2,
331 escaped_id
= 3, nonlocal_id
= 4,
332 storedanything_id
= 5, integer_id
= 6 };
334 /* Return a new variable info structure consisting for a variable
335 named NAME, and using constraint graph node NODE. Append it
336 to the vector of variable info structures. */
339 new_var_info (tree t
, const char *name
)
341 unsigned index
= VEC_length (varinfo_t
, varmap
);
342 varinfo_t ret
= (varinfo_t
) pool_alloc (variable_info_pool
);
347 /* Vars without decl are artificial and do not have sub-variables. */
348 ret
->is_artificial_var
= (t
== NULL_TREE
);
349 ret
->is_special_var
= false;
350 ret
->is_unknown_size_var
= false;
351 ret
->is_full_var
= (t
== NULL_TREE
);
352 ret
->is_heap_var
= false;
353 ret
->is_restrict_var
= false;
354 ret
->may_have_pointers
= true;
355 ret
->only_restrict_pointers
= false;
356 ret
->is_global_var
= (t
== NULL_TREE
);
357 ret
->is_fn_info
= false;
359 ret
->is_global_var
= (is_global_var (t
)
360 /* We have to treat even local register variables
362 || (TREE_CODE (t
) == VAR_DECL
363 && DECL_HARD_REGISTER (t
)));
364 ret
->solution
= BITMAP_ALLOC (&pta_obstack
);
365 ret
->oldsolution
= NULL
;
370 VEC_safe_push (varinfo_t
, heap
, varmap
, ret
);
376 /* A map mapping call statements to per-stmt variables for uses
377 and clobbers specific to the call. */
378 struct pointer_map_t
*call_stmt_vars
;
380 /* Lookup or create the variable for the call statement CALL. */
383 get_call_vi (gimple call
)
388 slot_p
= pointer_map_insert (call_stmt_vars
, call
);
390 return (varinfo_t
) *slot_p
;
392 vi
= new_var_info (NULL_TREE
, "CALLUSED");
396 vi
->is_full_var
= true;
398 vi
->next
= vi2
= new_var_info (NULL_TREE
, "CALLCLOBBERED");
402 vi2
->is_full_var
= true;
404 *slot_p
= (void *) vi
;
408 /* Lookup the variable for the call statement CALL representing
409 the uses. Returns NULL if there is nothing special about this call. */
412 lookup_call_use_vi (gimple call
)
416 slot_p
= pointer_map_contains (call_stmt_vars
, call
);
418 return (varinfo_t
) *slot_p
;
423 /* Lookup the variable for the call statement CALL representing
424 the clobbers. Returns NULL if there is nothing special about this call. */
427 lookup_call_clobber_vi (gimple call
)
429 varinfo_t uses
= lookup_call_use_vi (call
);
436 /* Lookup or create the variable for the call statement CALL representing
440 get_call_use_vi (gimple call
)
442 return get_call_vi (call
);
445 /* Lookup or create the variable for the call statement CALL representing
448 static varinfo_t ATTRIBUTE_UNUSED
449 get_call_clobber_vi (gimple call
)
451 return get_call_vi (call
)->next
;
455 typedef enum {SCALAR
, DEREF
, ADDRESSOF
} constraint_expr_type
;
457 /* An expression that appears in a constraint. */
459 struct constraint_expr
461 /* Constraint type. */
462 constraint_expr_type type
;
464 /* Variable we are referring to in the constraint. */
467 /* Offset, in bits, of this constraint from the beginning of
468 variables it ends up referring to.
470 IOW, in a deref constraint, we would deref, get the result set,
471 then add OFFSET to each member. */
472 HOST_WIDE_INT offset
;
475 /* Use 0x8000... as special unknown offset. */
476 #define UNKNOWN_OFFSET ((HOST_WIDE_INT)-1 << (HOST_BITS_PER_WIDE_INT-1))
478 typedef struct constraint_expr ce_s
;
480 DEF_VEC_ALLOC_O(ce_s
, heap
);
481 static void get_constraint_for_1 (tree
, VEC(ce_s
, heap
) **, bool, bool);
482 static void get_constraint_for (tree
, VEC(ce_s
, heap
) **);
483 static void get_constraint_for_rhs (tree
, VEC(ce_s
, heap
) **);
484 static void do_deref (VEC (ce_s
, heap
) **);
486 /* Our set constraints are made up of two constraint expressions, one
489 As described in the introduction, our set constraints each represent an
490 operation between set valued variables.
494 struct constraint_expr lhs
;
495 struct constraint_expr rhs
;
498 /* List of constraints that we use to build the constraint graph from. */
500 static VEC(constraint_t
,heap
) *constraints
;
501 static alloc_pool constraint_pool
;
503 /* The constraint graph is represented as an array of bitmaps
504 containing successor nodes. */
506 struct constraint_graph
508 /* Size of this graph, which may be different than the number of
509 nodes in the variable map. */
512 /* Explicit successors of each node. */
515 /* Implicit predecessors of each node (Used for variable
517 bitmap
*implicit_preds
;
519 /* Explicit predecessors of each node (Used for variable substitution). */
522 /* Indirect cycle representatives, or -1 if the node has no indirect
524 int *indirect_cycles
;
526 /* Representative node for a node. rep[a] == a unless the node has
530 /* Equivalence class representative for a label. This is used for
531 variable substitution. */
534 /* Pointer equivalence label for a node. All nodes with the same
535 pointer equivalence label can be unified together at some point
536 (either during constraint optimization or after the constraint
540 /* Pointer equivalence representative for a label. This is used to
541 handle nodes that are pointer equivalent but not location
542 equivalent. We can unite these once the addressof constraints
543 are transformed into initial points-to sets. */
546 /* Pointer equivalence label for each node, used during variable
548 unsigned int *pointer_label
;
550 /* Location equivalence label for each node, used during location
551 equivalence finding. */
552 unsigned int *loc_label
;
554 /* Pointed-by set for each node, used during location equivalence
555 finding. This is pointed-by rather than pointed-to, because it
556 is constructed using the predecessor graph. */
559 /* Points to sets for pointer equivalence. This is *not* the actual
560 points-to sets for nodes. */
563 /* Bitmap of nodes where the bit is set if the node is a direct
564 node. Used for variable substitution. */
565 sbitmap direct_nodes
;
567 /* Bitmap of nodes where the bit is set if the node is address
568 taken. Used for variable substitution. */
569 bitmap address_taken
;
571 /* Vector of complex constraints for each graph node. Complex
572 constraints are those involving dereferences or offsets that are
574 VEC(constraint_t
,heap
) **complex;
577 static constraint_graph_t graph
;
579 /* During variable substitution and the offline version of indirect
580 cycle finding, we create nodes to represent dereferences and
581 address taken constraints. These represent where these start and
583 #define FIRST_REF_NODE (VEC_length (varinfo_t, varmap))
584 #define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
586 /* Return the representative node for NODE, if NODE has been unioned
588 This function performs path compression along the way to finding
589 the representative. */
592 find (unsigned int node
)
594 gcc_assert (node
< graph
->size
);
595 if (graph
->rep
[node
] != node
)
596 return graph
->rep
[node
] = find (graph
->rep
[node
]);
600 /* Union the TO and FROM nodes to the TO nodes.
601 Note that at some point in the future, we may want to do
602 union-by-rank, in which case we are going to have to return the
603 node we unified to. */
606 unite (unsigned int to
, unsigned int from
)
608 gcc_assert (to
< graph
->size
&& from
< graph
->size
);
609 if (to
!= from
&& graph
->rep
[from
] != to
)
611 graph
->rep
[from
] = to
;
617 /* Create a new constraint consisting of LHS and RHS expressions. */
620 new_constraint (const struct constraint_expr lhs
,
621 const struct constraint_expr rhs
)
623 constraint_t ret
= (constraint_t
) pool_alloc (constraint_pool
);
629 /* Print out constraint C to FILE. */
632 dump_constraint (FILE *file
, constraint_t c
)
634 if (c
->lhs
.type
== ADDRESSOF
)
636 else if (c
->lhs
.type
== DEREF
)
638 fprintf (file
, "%s", get_varinfo (c
->lhs
.var
)->name
);
639 if (c
->lhs
.offset
== UNKNOWN_OFFSET
)
640 fprintf (file
, " + UNKNOWN");
641 else if (c
->lhs
.offset
!= 0)
642 fprintf (file
, " + " HOST_WIDE_INT_PRINT_DEC
, c
->lhs
.offset
);
643 fprintf (file
, " = ");
644 if (c
->rhs
.type
== ADDRESSOF
)
646 else if (c
->rhs
.type
== DEREF
)
648 fprintf (file
, "%s", get_varinfo (c
->rhs
.var
)->name
);
649 if (c
->rhs
.offset
== UNKNOWN_OFFSET
)
650 fprintf (file
, " + UNKNOWN");
651 else if (c
->rhs
.offset
!= 0)
652 fprintf (file
, " + " HOST_WIDE_INT_PRINT_DEC
, c
->rhs
.offset
);
656 void debug_constraint (constraint_t
);
657 void debug_constraints (void);
658 void debug_constraint_graph (void);
659 void debug_solution_for_var (unsigned int);
660 void debug_sa_points_to_info (void);
662 /* Print out constraint C to stderr. */
665 debug_constraint (constraint_t c
)
667 dump_constraint (stderr
, c
);
668 fprintf (stderr
, "\n");
671 /* Print out all constraints to FILE */
674 dump_constraints (FILE *file
, int from
)
678 for (i
= from
; VEC_iterate (constraint_t
, constraints
, i
, c
); i
++)
681 dump_constraint (file
, c
);
682 fprintf (file
, "\n");
686 /* Print out all constraints to stderr. */
689 debug_constraints (void)
691 dump_constraints (stderr
, 0);
694 /* Print the constraint graph in dot format. */
697 dump_constraint_graph (FILE *file
)
701 /* Only print the graph if it has already been initialized: */
705 /* Prints the header of the dot file: */
706 fprintf (file
, "strict digraph {\n");
707 fprintf (file
, " node [\n shape = box\n ]\n");
708 fprintf (file
, " edge [\n fontsize = \"12\"\n ]\n");
709 fprintf (file
, "\n // List of nodes and complex constraints in "
710 "the constraint graph:\n");
712 /* The next lines print the nodes in the graph together with the
713 complex constraints attached to them. */
714 for (i
= 0; i
< graph
->size
; i
++)
718 if (i
< FIRST_REF_NODE
)
719 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
721 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
722 if (graph
->complex[i
])
726 fprintf (file
, " [label=\"\\N\\n");
727 for (j
= 0; VEC_iterate (constraint_t
, graph
->complex[i
], j
, c
); ++j
)
729 dump_constraint (file
, c
);
730 fprintf (file
, "\\l");
732 fprintf (file
, "\"]");
734 fprintf (file
, ";\n");
737 /* Go over the edges. */
738 fprintf (file
, "\n // Edges in the constraint graph:\n");
739 for (i
= 0; i
< graph
->size
; i
++)
745 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[i
], 0, j
, bi
)
747 unsigned to
= find (j
);
750 if (i
< FIRST_REF_NODE
)
751 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
753 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
754 fprintf (file
, " -> ");
755 if (to
< FIRST_REF_NODE
)
756 fprintf (file
, "\"%s\"", get_varinfo (to
)->name
);
758 fprintf (file
, "\"*%s\"", get_varinfo (to
- FIRST_REF_NODE
)->name
);
759 fprintf (file
, ";\n");
763 /* Prints the tail of the dot file. */
764 fprintf (file
, "}\n");
767 /* Print out the constraint graph to stderr. */
770 debug_constraint_graph (void)
772 dump_constraint_graph (stderr
);
777 The solver is a simple worklist solver, that works on the following
780 sbitmap changed_nodes = all zeroes;
782 For each node that is not already collapsed:
784 set bit in changed nodes
786 while (changed_count > 0)
788 compute topological ordering for constraint graph
790 find and collapse cycles in the constraint graph (updating
791 changed if necessary)
793 for each node (n) in the graph in topological order:
796 Process each complex constraint associated with the node,
797 updating changed if necessary.
799 For each outgoing edge from n, propagate the solution from n to
800 the destination of the edge, updating changed as necessary.
804 /* Return true if two constraint expressions A and B are equal. */
807 constraint_expr_equal (struct constraint_expr a
, struct constraint_expr b
)
809 return a
.type
== b
.type
&& a
.var
== b
.var
&& a
.offset
== b
.offset
;
812 /* Return true if constraint expression A is less than constraint expression
813 B. This is just arbitrary, but consistent, in order to give them an
817 constraint_expr_less (struct constraint_expr a
, struct constraint_expr b
)
819 if (a
.type
== b
.type
)
822 return a
.offset
< b
.offset
;
824 return a
.var
< b
.var
;
827 return a
.type
< b
.type
;
830 /* Return true if constraint A is less than constraint B. This is just
831 arbitrary, but consistent, in order to give them an ordering. */
834 constraint_less (const constraint_t a
, const constraint_t b
)
836 if (constraint_expr_less (a
->lhs
, b
->lhs
))
838 else if (constraint_expr_less (b
->lhs
, a
->lhs
))
841 return constraint_expr_less (a
->rhs
, b
->rhs
);
844 /* Return true if two constraints A and B are equal. */
847 constraint_equal (struct constraint a
, struct constraint b
)
849 return constraint_expr_equal (a
.lhs
, b
.lhs
)
850 && constraint_expr_equal (a
.rhs
, b
.rhs
);
854 /* Find a constraint LOOKFOR in the sorted constraint vector VEC */
857 constraint_vec_find (VEC(constraint_t
,heap
) *vec
,
858 struct constraint lookfor
)
866 place
= VEC_lower_bound (constraint_t
, vec
, &lookfor
, constraint_less
);
867 if (place
>= VEC_length (constraint_t
, vec
))
869 found
= VEC_index (constraint_t
, vec
, place
);
870 if (!constraint_equal (*found
, lookfor
))
875 /* Union two constraint vectors, TO and FROM. Put the result in TO. */
878 constraint_set_union (VEC(constraint_t
,heap
) **to
,
879 VEC(constraint_t
,heap
) **from
)
884 FOR_EACH_VEC_ELT (constraint_t
, *from
, i
, c
)
886 if (constraint_vec_find (*to
, *c
) == NULL
)
888 unsigned int place
= VEC_lower_bound (constraint_t
, *to
, c
,
890 VEC_safe_insert (constraint_t
, heap
, *to
, place
, c
);
895 /* Expands the solution in SET to all sub-fields of variables included.
896 Union the expanded result into RESULT. */
899 solution_set_expand (bitmap result
, bitmap set
)
905 /* In a first pass record all variables we need to add all
906 sub-fields off. This avoids quadratic behavior. */
907 EXECUTE_IF_SET_IN_BITMAP (set
, 0, j
, bi
)
909 varinfo_t v
= get_varinfo (j
);
910 if (v
->is_artificial_var
913 v
= lookup_vi_for_tree (v
->decl
);
915 vars
= BITMAP_ALLOC (NULL
);
916 bitmap_set_bit (vars
, v
->id
);
919 /* In the second pass now do the addition to the solution and
920 to speed up solving add it to the delta as well. */
923 EXECUTE_IF_SET_IN_BITMAP (vars
, 0, j
, bi
)
925 varinfo_t v
= get_varinfo (j
);
926 for (; v
!= NULL
; v
= v
->next
)
927 bitmap_set_bit (result
, v
->id
);
933 /* Take a solution set SET, add OFFSET to each member of the set, and
934 overwrite SET with the result when done. */
937 solution_set_add (bitmap set
, HOST_WIDE_INT offset
)
939 bitmap result
= BITMAP_ALLOC (&iteration_obstack
);
943 /* If the offset is unknown we have to expand the solution to
945 if (offset
== UNKNOWN_OFFSET
)
947 solution_set_expand (set
, set
);
951 EXECUTE_IF_SET_IN_BITMAP (set
, 0, i
, bi
)
953 varinfo_t vi
= get_varinfo (i
);
955 /* If this is a variable with just one field just set its bit
957 if (vi
->is_artificial_var
958 || vi
->is_unknown_size_var
960 bitmap_set_bit (result
, i
);
963 unsigned HOST_WIDE_INT fieldoffset
= vi
->offset
+ offset
;
965 /* If the offset makes the pointer point to before the
966 variable use offset zero for the field lookup. */
968 && fieldoffset
> vi
->offset
)
972 vi
= first_or_preceding_vi_for_offset (vi
, fieldoffset
);
974 bitmap_set_bit (result
, vi
->id
);
975 /* If the result is not exactly at fieldoffset include the next
976 field as well. See get_constraint_for_ptr_offset for more
978 if (vi
->offset
!= fieldoffset
980 bitmap_set_bit (result
, vi
->next
->id
);
984 bitmap_copy (set
, result
);
985 BITMAP_FREE (result
);
988 /* Union solution sets TO and FROM, and add INC to each member of FROM in the
992 set_union_with_increment (bitmap to
, bitmap from
, HOST_WIDE_INT inc
)
995 return bitmap_ior_into (to
, from
);
1001 tmp
= BITMAP_ALLOC (&iteration_obstack
);
1002 bitmap_copy (tmp
, from
);
1003 solution_set_add (tmp
, inc
);
1004 res
= bitmap_ior_into (to
, tmp
);
1010 /* Insert constraint C into the list of complex constraints for graph
1014 insert_into_complex (constraint_graph_t graph
,
1015 unsigned int var
, constraint_t c
)
1017 VEC (constraint_t
, heap
) *complex = graph
->complex[var
];
1018 unsigned int place
= VEC_lower_bound (constraint_t
, complex, c
,
1021 /* Only insert constraints that do not already exist. */
1022 if (place
>= VEC_length (constraint_t
, complex)
1023 || !constraint_equal (*c
, *VEC_index (constraint_t
, complex, place
)))
1024 VEC_safe_insert (constraint_t
, heap
, graph
->complex[var
], place
, c
);
1028 /* Condense two variable nodes into a single variable node, by moving
1029 all associated info from SRC to TO. */
1032 merge_node_constraints (constraint_graph_t graph
, unsigned int to
,
1038 gcc_assert (find (from
) == to
);
1040 /* Move all complex constraints from src node into to node */
1041 FOR_EACH_VEC_ELT (constraint_t
, graph
->complex[from
], i
, c
)
1043 /* In complex constraints for node src, we may have either
1044 a = *src, and *src = a, or an offseted constraint which are
1045 always added to the rhs node's constraints. */
1047 if (c
->rhs
.type
== DEREF
)
1049 else if (c
->lhs
.type
== DEREF
)
1054 constraint_set_union (&graph
->complex[to
], &graph
->complex[from
]);
1055 VEC_free (constraint_t
, heap
, graph
->complex[from
]);
1056 graph
->complex[from
] = NULL
;
1060 /* Remove edges involving NODE from GRAPH. */
1063 clear_edges_for_node (constraint_graph_t graph
, unsigned int node
)
1065 if (graph
->succs
[node
])
1066 BITMAP_FREE (graph
->succs
[node
]);
1069 /* Merge GRAPH nodes FROM and TO into node TO. */
1072 merge_graph_nodes (constraint_graph_t graph
, unsigned int to
,
1075 if (graph
->indirect_cycles
[from
] != -1)
1077 /* If we have indirect cycles with the from node, and we have
1078 none on the to node, the to node has indirect cycles from the
1079 from node now that they are unified.
1080 If indirect cycles exist on both, unify the nodes that they
1081 are in a cycle with, since we know they are in a cycle with
1083 if (graph
->indirect_cycles
[to
] == -1)
1084 graph
->indirect_cycles
[to
] = graph
->indirect_cycles
[from
];
1087 /* Merge all the successor edges. */
1088 if (graph
->succs
[from
])
1090 if (!graph
->succs
[to
])
1091 graph
->succs
[to
] = BITMAP_ALLOC (&pta_obstack
);
1092 bitmap_ior_into (graph
->succs
[to
],
1093 graph
->succs
[from
]);
1096 clear_edges_for_node (graph
, from
);
1100 /* Add an indirect graph edge to GRAPH, going from TO to FROM if
1101 it doesn't exist in the graph already. */
1104 add_implicit_graph_edge (constraint_graph_t graph
, unsigned int to
,
1110 if (!graph
->implicit_preds
[to
])
1111 graph
->implicit_preds
[to
] = BITMAP_ALLOC (&predbitmap_obstack
);
1113 if (bitmap_set_bit (graph
->implicit_preds
[to
], from
))
1114 stats
.num_implicit_edges
++;
1117 /* Add a predecessor graph edge to GRAPH, going from TO to FROM if
1118 it doesn't exist in the graph already.
1119 Return false if the edge already existed, true otherwise. */
1122 add_pred_graph_edge (constraint_graph_t graph
, unsigned int to
,
1125 if (!graph
->preds
[to
])
1126 graph
->preds
[to
] = BITMAP_ALLOC (&predbitmap_obstack
);
1127 bitmap_set_bit (graph
->preds
[to
], from
);
1130 /* Add a graph edge to GRAPH, going from FROM to TO if
1131 it doesn't exist in the graph already.
1132 Return false if the edge already existed, true otherwise. */
1135 add_graph_edge (constraint_graph_t graph
, unsigned int to
,
1146 if (!graph
->succs
[from
])
1147 graph
->succs
[from
] = BITMAP_ALLOC (&pta_obstack
);
1148 if (bitmap_set_bit (graph
->succs
[from
], to
))
1151 if (to
< FIRST_REF_NODE
&& from
< FIRST_REF_NODE
)
1159 /* Return true if {DEST.SRC} is an existing graph edge in GRAPH. */
1162 valid_graph_edge (constraint_graph_t graph
, unsigned int src
,
1165 return (graph
->succs
[dest
]
1166 && bitmap_bit_p (graph
->succs
[dest
], src
));
1169 /* Initialize the constraint graph structure to contain SIZE nodes. */
1172 init_graph (unsigned int size
)
1176 graph
= XCNEW (struct constraint_graph
);
1178 graph
->succs
= XCNEWVEC (bitmap
, graph
->size
);
1179 graph
->indirect_cycles
= XNEWVEC (int, graph
->size
);
1180 graph
->rep
= XNEWVEC (unsigned int, graph
->size
);
1181 graph
->complex = XCNEWVEC (VEC(constraint_t
, heap
) *, size
);
1182 graph
->pe
= XCNEWVEC (unsigned int, graph
->size
);
1183 graph
->pe_rep
= XNEWVEC (int, graph
->size
);
1185 for (j
= 0; j
< graph
->size
; j
++)
1188 graph
->pe_rep
[j
] = -1;
1189 graph
->indirect_cycles
[j
] = -1;
1193 /* Build the constraint graph, adding only predecessor edges right now. */
1196 build_pred_graph (void)
1202 graph
->implicit_preds
= XCNEWVEC (bitmap
, graph
->size
);
1203 graph
->preds
= XCNEWVEC (bitmap
, graph
->size
);
1204 graph
->pointer_label
= XCNEWVEC (unsigned int, graph
->size
);
1205 graph
->loc_label
= XCNEWVEC (unsigned int, graph
->size
);
1206 graph
->pointed_by
= XCNEWVEC (bitmap
, graph
->size
);
1207 graph
->points_to
= XCNEWVEC (bitmap
, graph
->size
);
1208 graph
->eq_rep
= XNEWVEC (int, graph
->size
);
1209 graph
->direct_nodes
= sbitmap_alloc (graph
->size
);
1210 graph
->address_taken
= BITMAP_ALLOC (&predbitmap_obstack
);
1211 sbitmap_zero (graph
->direct_nodes
);
1213 for (j
= 0; j
< FIRST_REF_NODE
; j
++)
1215 if (!get_varinfo (j
)->is_special_var
)
1216 SET_BIT (graph
->direct_nodes
, j
);
1219 for (j
= 0; j
< graph
->size
; j
++)
1220 graph
->eq_rep
[j
] = -1;
1222 for (j
= 0; j
< VEC_length (varinfo_t
, varmap
); j
++)
1223 graph
->indirect_cycles
[j
] = -1;
1225 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
1227 struct constraint_expr lhs
= c
->lhs
;
1228 struct constraint_expr rhs
= c
->rhs
;
1229 unsigned int lhsvar
= lhs
.var
;
1230 unsigned int rhsvar
= rhs
.var
;
1232 if (lhs
.type
== DEREF
)
1235 if (rhs
.offset
== 0 && lhs
.offset
== 0 && rhs
.type
== SCALAR
)
1236 add_pred_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1238 else if (rhs
.type
== DEREF
)
1241 if (rhs
.offset
== 0 && lhs
.offset
== 0 && lhs
.type
== SCALAR
)
1242 add_pred_graph_edge (graph
, lhsvar
, FIRST_REF_NODE
+ rhsvar
);
1244 RESET_BIT (graph
->direct_nodes
, lhsvar
);
1246 else if (rhs
.type
== ADDRESSOF
)
1251 if (graph
->points_to
[lhsvar
] == NULL
)
1252 graph
->points_to
[lhsvar
] = BITMAP_ALLOC (&predbitmap_obstack
);
1253 bitmap_set_bit (graph
->points_to
[lhsvar
], rhsvar
);
1255 if (graph
->pointed_by
[rhsvar
] == NULL
)
1256 graph
->pointed_by
[rhsvar
] = BITMAP_ALLOC (&predbitmap_obstack
);
1257 bitmap_set_bit (graph
->pointed_by
[rhsvar
], lhsvar
);
1259 /* Implicitly, *x = y */
1260 add_implicit_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1262 /* All related variables are no longer direct nodes. */
1263 RESET_BIT (graph
->direct_nodes
, rhsvar
);
1264 v
= get_varinfo (rhsvar
);
1265 if (!v
->is_full_var
)
1267 v
= lookup_vi_for_tree (v
->decl
);
1270 RESET_BIT (graph
->direct_nodes
, v
->id
);
1275 bitmap_set_bit (graph
->address_taken
, rhsvar
);
1277 else if (lhsvar
> anything_id
1278 && lhsvar
!= rhsvar
&& lhs
.offset
== 0 && rhs
.offset
== 0)
1281 add_pred_graph_edge (graph
, lhsvar
, rhsvar
);
1282 /* Implicitly, *x = *y */
1283 add_implicit_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
,
1284 FIRST_REF_NODE
+ rhsvar
);
1286 else if (lhs
.offset
!= 0 || rhs
.offset
!= 0)
1288 if (rhs
.offset
!= 0)
1289 RESET_BIT (graph
->direct_nodes
, lhs
.var
);
1290 else if (lhs
.offset
!= 0)
1291 RESET_BIT (graph
->direct_nodes
, rhs
.var
);
1296 /* Build the constraint graph, adding successor edges. */
1299 build_succ_graph (void)
1304 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
1306 struct constraint_expr lhs
;
1307 struct constraint_expr rhs
;
1308 unsigned int lhsvar
;
1309 unsigned int rhsvar
;
1316 lhsvar
= find (lhs
.var
);
1317 rhsvar
= find (rhs
.var
);
1319 if (lhs
.type
== DEREF
)
1321 if (rhs
.offset
== 0 && lhs
.offset
== 0 && rhs
.type
== SCALAR
)
1322 add_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1324 else if (rhs
.type
== DEREF
)
1326 if (rhs
.offset
== 0 && lhs
.offset
== 0 && lhs
.type
== SCALAR
)
1327 add_graph_edge (graph
, lhsvar
, FIRST_REF_NODE
+ rhsvar
);
1329 else if (rhs
.type
== ADDRESSOF
)
1332 gcc_assert (find (rhs
.var
) == rhs
.var
);
1333 bitmap_set_bit (get_varinfo (lhsvar
)->solution
, rhsvar
);
1335 else if (lhsvar
> anything_id
1336 && lhsvar
!= rhsvar
&& lhs
.offset
== 0 && rhs
.offset
== 0)
1338 add_graph_edge (graph
, lhsvar
, rhsvar
);
1342 /* Add edges from STOREDANYTHING to all non-direct nodes that can
1343 receive pointers. */
1344 t
= find (storedanything_id
);
1345 for (i
= integer_id
+ 1; i
< FIRST_REF_NODE
; ++i
)
1347 if (!TEST_BIT (graph
->direct_nodes
, i
)
1348 && get_varinfo (i
)->may_have_pointers
)
1349 add_graph_edge (graph
, find (i
), t
);
1352 /* Everything stored to ANYTHING also potentially escapes. */
1353 add_graph_edge (graph
, find (escaped_id
), t
);
1357 /* Changed variables on the last iteration. */
1358 static bitmap changed
;
1360 /* Strongly Connected Component visitation info. */
1367 unsigned int *node_mapping
;
1369 VEC(unsigned,heap
) *scc_stack
;
1373 /* Recursive routine to find strongly connected components in GRAPH.
1374 SI is the SCC info to store the information in, and N is the id of current
1375 graph node we are processing.
1377 This is Tarjan's strongly connected component finding algorithm, as
1378 modified by Nuutila to keep only non-root nodes on the stack.
1379 The algorithm can be found in "On finding the strongly connected
1380 connected components in a directed graph" by Esko Nuutila and Eljas
1381 Soisalon-Soininen, in Information Processing Letters volume 49,
1382 number 1, pages 9-14. */
1385 scc_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
1389 unsigned int my_dfs
;
1391 SET_BIT (si
->visited
, n
);
1392 si
->dfs
[n
] = si
->current_index
++;
1393 my_dfs
= si
->dfs
[n
];
1395 /* Visit all the successors. */
1396 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[n
], 0, i
, bi
)
1400 if (i
> LAST_REF_NODE
)
1404 if (TEST_BIT (si
->deleted
, w
))
1407 if (!TEST_BIT (si
->visited
, w
))
1408 scc_visit (graph
, si
, w
);
1410 unsigned int t
= find (w
);
1411 unsigned int nnode
= find (n
);
1412 gcc_assert (nnode
== n
);
1414 if (si
->dfs
[t
] < si
->dfs
[nnode
])
1415 si
->dfs
[n
] = si
->dfs
[t
];
1419 /* See if any components have been identified. */
1420 if (si
->dfs
[n
] == my_dfs
)
1422 if (VEC_length (unsigned, si
->scc_stack
) > 0
1423 && si
->dfs
[VEC_last (unsigned, si
->scc_stack
)] >= my_dfs
)
1425 bitmap scc
= BITMAP_ALLOC (NULL
);
1426 unsigned int lowest_node
;
1429 bitmap_set_bit (scc
, n
);
1431 while (VEC_length (unsigned, si
->scc_stack
) != 0
1432 && si
->dfs
[VEC_last (unsigned, si
->scc_stack
)] >= my_dfs
)
1434 unsigned int w
= VEC_pop (unsigned, si
->scc_stack
);
1436 bitmap_set_bit (scc
, w
);
1439 lowest_node
= bitmap_first_set_bit (scc
);
1440 gcc_assert (lowest_node
< FIRST_REF_NODE
);
1442 /* Collapse the SCC nodes into a single node, and mark the
1444 EXECUTE_IF_SET_IN_BITMAP (scc
, 0, i
, bi
)
1446 if (i
< FIRST_REF_NODE
)
1448 if (unite (lowest_node
, i
))
1449 unify_nodes (graph
, lowest_node
, i
, false);
1453 unite (lowest_node
, i
);
1454 graph
->indirect_cycles
[i
- FIRST_REF_NODE
] = lowest_node
;
1458 SET_BIT (si
->deleted
, n
);
1461 VEC_safe_push (unsigned, heap
, si
->scc_stack
, n
);
1464 /* Unify node FROM into node TO, updating the changed count if
1465 necessary when UPDATE_CHANGED is true. */
1468 unify_nodes (constraint_graph_t graph
, unsigned int to
, unsigned int from
,
1469 bool update_changed
)
1472 gcc_assert (to
!= from
&& find (to
) == to
);
1473 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1474 fprintf (dump_file
, "Unifying %s to %s\n",
1475 get_varinfo (from
)->name
,
1476 get_varinfo (to
)->name
);
1479 stats
.unified_vars_dynamic
++;
1481 stats
.unified_vars_static
++;
1483 merge_graph_nodes (graph
, to
, from
);
1484 merge_node_constraints (graph
, to
, from
);
1486 /* Mark TO as changed if FROM was changed. If TO was already marked
1487 as changed, decrease the changed count. */
1490 && bitmap_bit_p (changed
, from
))
1492 bitmap_clear_bit (changed
, from
);
1493 bitmap_set_bit (changed
, to
);
1495 if (get_varinfo (from
)->solution
)
1497 /* If the solution changes because of the merging, we need to mark
1498 the variable as changed. */
1499 if (bitmap_ior_into (get_varinfo (to
)->solution
,
1500 get_varinfo (from
)->solution
))
1503 bitmap_set_bit (changed
, to
);
1506 BITMAP_FREE (get_varinfo (from
)->solution
);
1507 if (get_varinfo (from
)->oldsolution
)
1508 BITMAP_FREE (get_varinfo (from
)->oldsolution
);
1510 if (stats
.iterations
> 0
1511 && get_varinfo (to
)->oldsolution
)
1512 BITMAP_FREE (get_varinfo (to
)->oldsolution
);
1514 if (valid_graph_edge (graph
, to
, to
))
1516 if (graph
->succs
[to
])
1517 bitmap_clear_bit (graph
->succs
[to
], to
);
1521 /* Information needed to compute the topological ordering of a graph. */
1525 /* sbitmap of visited nodes. */
1527 /* Array that stores the topological order of the graph, *in
1529 VEC(unsigned,heap
) *topo_order
;
1533 /* Initialize and return a topological info structure. */
1535 static struct topo_info
*
1536 init_topo_info (void)
1538 size_t size
= graph
->size
;
1539 struct topo_info
*ti
= XNEW (struct topo_info
);
1540 ti
->visited
= sbitmap_alloc (size
);
1541 sbitmap_zero (ti
->visited
);
1542 ti
->topo_order
= VEC_alloc (unsigned, heap
, 1);
1547 /* Free the topological sort info pointed to by TI. */
1550 free_topo_info (struct topo_info
*ti
)
1552 sbitmap_free (ti
->visited
);
1553 VEC_free (unsigned, heap
, ti
->topo_order
);
1557 /* Visit the graph in topological order, and store the order in the
1558 topo_info structure. */
1561 topo_visit (constraint_graph_t graph
, struct topo_info
*ti
,
1567 SET_BIT (ti
->visited
, n
);
1569 if (graph
->succs
[n
])
1570 EXECUTE_IF_SET_IN_BITMAP (graph
->succs
[n
], 0, j
, bi
)
1572 if (!TEST_BIT (ti
->visited
, j
))
1573 topo_visit (graph
, ti
, j
);
1576 VEC_safe_push (unsigned, heap
, ti
->topo_order
, n
);
1579 /* Process a constraint C that represents x = *(y + off), using DELTA as the
1580 starting solution for y. */
1583 do_sd_constraint (constraint_graph_t graph
, constraint_t c
,
1586 unsigned int lhs
= c
->lhs
.var
;
1588 bitmap sol
= get_varinfo (lhs
)->solution
;
1591 HOST_WIDE_INT roffset
= c
->rhs
.offset
;
1593 /* Our IL does not allow this. */
1594 gcc_assert (c
->lhs
.offset
== 0);
1596 /* If the solution of Y contains anything it is good enough to transfer
1598 if (bitmap_bit_p (delta
, anything_id
))
1600 flag
|= bitmap_set_bit (sol
, anything_id
);
1604 /* If we do not know at with offset the rhs is dereferenced compute
1605 the reachability set of DELTA, conservatively assuming it is
1606 dereferenced at all valid offsets. */
1607 if (roffset
== UNKNOWN_OFFSET
)
1609 solution_set_expand (delta
, delta
);
1610 /* No further offset processing is necessary. */
1614 /* For each variable j in delta (Sol(y)), add
1615 an edge in the graph from j to x, and union Sol(j) into Sol(x). */
1616 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, j
, bi
)
1618 varinfo_t v
= get_varinfo (j
);
1619 HOST_WIDE_INT fieldoffset
= v
->offset
+ roffset
;
1623 fieldoffset
= v
->offset
;
1624 else if (roffset
!= 0)
1625 v
= first_vi_for_offset (v
, fieldoffset
);
1626 /* If the access is outside of the variable we can ignore it. */
1634 /* Adding edges from the special vars is pointless.
1635 They don't have sets that can change. */
1636 if (get_varinfo (t
)->is_special_var
)
1637 flag
|= bitmap_ior_into (sol
, get_varinfo (t
)->solution
);
1638 /* Merging the solution from ESCAPED needlessly increases
1639 the set. Use ESCAPED as representative instead. */
1640 else if (v
->id
== escaped_id
)
1641 flag
|= bitmap_set_bit (sol
, escaped_id
);
1642 else if (v
->may_have_pointers
1643 && add_graph_edge (graph
, lhs
, t
))
1644 flag
|= bitmap_ior_into (sol
, get_varinfo (t
)->solution
);
1646 /* If the variable is not exactly at the requested offset
1647 we have to include the next one. */
1648 if (v
->offset
== (unsigned HOST_WIDE_INT
)fieldoffset
1653 fieldoffset
= v
->offset
;
1659 /* If the LHS solution changed, mark the var as changed. */
1662 get_varinfo (lhs
)->solution
= sol
;
1663 bitmap_set_bit (changed
, lhs
);
1667 /* Process a constraint C that represents *(x + off) = y using DELTA
1668 as the starting solution for x. */
1671 do_ds_constraint (constraint_t c
, bitmap delta
)
1673 unsigned int rhs
= c
->rhs
.var
;
1674 bitmap sol
= get_varinfo (rhs
)->solution
;
1677 HOST_WIDE_INT loff
= c
->lhs
.offset
;
1678 bool escaped_p
= false;
1680 /* Our IL does not allow this. */
1681 gcc_assert (c
->rhs
.offset
== 0);
1683 /* If the solution of y contains ANYTHING simply use the ANYTHING
1684 solution. This avoids needlessly increasing the points-to sets. */
1685 if (bitmap_bit_p (sol
, anything_id
))
1686 sol
= get_varinfo (find (anything_id
))->solution
;
1688 /* If the solution for x contains ANYTHING we have to merge the
1689 solution of y into all pointer variables which we do via
1691 if (bitmap_bit_p (delta
, anything_id
))
1693 unsigned t
= find (storedanything_id
);
1694 if (add_graph_edge (graph
, t
, rhs
))
1696 if (bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1697 bitmap_set_bit (changed
, t
);
1702 /* If we do not know at with offset the rhs is dereferenced compute
1703 the reachability set of DELTA, conservatively assuming it is
1704 dereferenced at all valid offsets. */
1705 if (loff
== UNKNOWN_OFFSET
)
1707 solution_set_expand (delta
, delta
);
1711 /* For each member j of delta (Sol(x)), add an edge from y to j and
1712 union Sol(y) into Sol(j) */
1713 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, j
, bi
)
1715 varinfo_t v
= get_varinfo (j
);
1717 HOST_WIDE_INT fieldoffset
= v
->offset
+ loff
;
1720 fieldoffset
= v
->offset
;
1722 v
= first_vi_for_offset (v
, fieldoffset
);
1723 /* If the access is outside of the variable we can ignore it. */
1729 if (v
->may_have_pointers
)
1731 /* If v is a global variable then this is an escape point. */
1732 if (v
->is_global_var
1735 t
= find (escaped_id
);
1736 if (add_graph_edge (graph
, t
, rhs
)
1737 && bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1738 bitmap_set_bit (changed
, t
);
1739 /* Enough to let rhs escape once. */
1743 if (v
->is_special_var
)
1747 if (add_graph_edge (graph
, t
, rhs
)
1748 && bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1749 bitmap_set_bit (changed
, t
);
1752 /* If the variable is not exactly at the requested offset
1753 we have to include the next one. */
1754 if (v
->offset
== (unsigned HOST_WIDE_INT
)fieldoffset
1759 fieldoffset
= v
->offset
;
1765 /* Handle a non-simple (simple meaning requires no iteration),
1766 constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
1769 do_complex_constraint (constraint_graph_t graph
, constraint_t c
, bitmap delta
)
1771 if (c
->lhs
.type
== DEREF
)
1773 if (c
->rhs
.type
== ADDRESSOF
)
1780 do_ds_constraint (c
, delta
);
1783 else if (c
->rhs
.type
== DEREF
)
1786 if (!(get_varinfo (c
->lhs
.var
)->is_special_var
))
1787 do_sd_constraint (graph
, c
, delta
);
1795 gcc_assert (c
->rhs
.type
== SCALAR
&& c
->lhs
.type
== SCALAR
);
1796 solution
= get_varinfo (c
->rhs
.var
)->solution
;
1797 tmp
= get_varinfo (c
->lhs
.var
)->solution
;
1799 flag
= set_union_with_increment (tmp
, solution
, c
->rhs
.offset
);
1803 get_varinfo (c
->lhs
.var
)->solution
= tmp
;
1804 bitmap_set_bit (changed
, c
->lhs
.var
);
1809 /* Initialize and return a new SCC info structure. */
1811 static struct scc_info
*
1812 init_scc_info (size_t size
)
1814 struct scc_info
*si
= XNEW (struct scc_info
);
1817 si
->current_index
= 0;
1818 si
->visited
= sbitmap_alloc (size
);
1819 sbitmap_zero (si
->visited
);
1820 si
->deleted
= sbitmap_alloc (size
);
1821 sbitmap_zero (si
->deleted
);
1822 si
->node_mapping
= XNEWVEC (unsigned int, size
);
1823 si
->dfs
= XCNEWVEC (unsigned int, size
);
1825 for (i
= 0; i
< size
; i
++)
1826 si
->node_mapping
[i
] = i
;
1828 si
->scc_stack
= VEC_alloc (unsigned, heap
, 1);
1832 /* Free an SCC info structure pointed to by SI */
1835 free_scc_info (struct scc_info
*si
)
1837 sbitmap_free (si
->visited
);
1838 sbitmap_free (si
->deleted
);
1839 free (si
->node_mapping
);
1841 VEC_free (unsigned, heap
, si
->scc_stack
);
1846 /* Find indirect cycles in GRAPH that occur, using strongly connected
1847 components, and note them in the indirect cycles map.
1849 This technique comes from Ben Hardekopf and Calvin Lin,
1850 "It Pays to be Lazy: Fast and Accurate Pointer Analysis for Millions of
1851 Lines of Code", submitted to PLDI 2007. */
1854 find_indirect_cycles (constraint_graph_t graph
)
1857 unsigned int size
= graph
->size
;
1858 struct scc_info
*si
= init_scc_info (size
);
1860 for (i
= 0; i
< MIN (LAST_REF_NODE
, size
); i
++ )
1861 if (!TEST_BIT (si
->visited
, i
) && find (i
) == i
)
1862 scc_visit (graph
, si
, i
);
1867 /* Compute a topological ordering for GRAPH, and store the result in the
1868 topo_info structure TI. */
1871 compute_topo_order (constraint_graph_t graph
,
1872 struct topo_info
*ti
)
1875 unsigned int size
= graph
->size
;
1877 for (i
= 0; i
!= size
; ++i
)
1878 if (!TEST_BIT (ti
->visited
, i
) && find (i
) == i
)
1879 topo_visit (graph
, ti
, i
);
1882 /* Structure used to for hash value numbering of pointer equivalence
1885 typedef struct equiv_class_label
1888 unsigned int equivalence_class
;
1890 } *equiv_class_label_t
;
1891 typedef const struct equiv_class_label
*const_equiv_class_label_t
;
1893 /* A hashtable for mapping a bitmap of labels->pointer equivalence
1895 static htab_t pointer_equiv_class_table
;
1897 /* A hashtable for mapping a bitmap of labels->location equivalence
1899 static htab_t location_equiv_class_table
;
1901 /* Hash function for a equiv_class_label_t */
1904 equiv_class_label_hash (const void *p
)
1906 const_equiv_class_label_t
const ecl
= (const_equiv_class_label_t
) p
;
1907 return ecl
->hashcode
;
1910 /* Equality function for two equiv_class_label_t's. */
1913 equiv_class_label_eq (const void *p1
, const void *p2
)
1915 const_equiv_class_label_t
const eql1
= (const_equiv_class_label_t
) p1
;
1916 const_equiv_class_label_t
const eql2
= (const_equiv_class_label_t
) p2
;
1917 return (eql1
->hashcode
== eql2
->hashcode
1918 && bitmap_equal_p (eql1
->labels
, eql2
->labels
));
1921 /* Lookup a equivalence class in TABLE by the bitmap of LABELS it
1925 equiv_class_lookup (htab_t table
, bitmap labels
)
1928 struct equiv_class_label ecl
;
1930 ecl
.labels
= labels
;
1931 ecl
.hashcode
= bitmap_hash (labels
);
1933 slot
= htab_find_slot_with_hash (table
, &ecl
,
1934 ecl
.hashcode
, NO_INSERT
);
1938 return ((equiv_class_label_t
) *slot
)->equivalence_class
;
1942 /* Add an equivalence class named EQUIVALENCE_CLASS with labels LABELS
1946 equiv_class_add (htab_t table
, unsigned int equivalence_class
,
1950 equiv_class_label_t ecl
= XNEW (struct equiv_class_label
);
1952 ecl
->labels
= labels
;
1953 ecl
->equivalence_class
= equivalence_class
;
1954 ecl
->hashcode
= bitmap_hash (labels
);
1956 slot
= htab_find_slot_with_hash (table
, ecl
,
1957 ecl
->hashcode
, INSERT
);
1958 gcc_assert (!*slot
);
1959 *slot
= (void *) ecl
;
1962 /* Perform offline variable substitution.
1964 This is a worst case quadratic time way of identifying variables
1965 that must have equivalent points-to sets, including those caused by
1966 static cycles, and single entry subgraphs, in the constraint graph.
1968 The technique is described in "Exploiting Pointer and Location
1969 Equivalence to Optimize Pointer Analysis. In the 14th International
1970 Static Analysis Symposium (SAS), August 2007." It is known as the
1971 "HU" algorithm, and is equivalent to value numbering the collapsed
1972 constraint graph including evaluating unions.
1974 The general method of finding equivalence classes is as follows:
1975 Add fake nodes (REF nodes) and edges for *a = b and a = *b constraints.
1976 Initialize all non-REF nodes to be direct nodes.
1977 For each constraint a = a U {b}, we set pts(a) = pts(a) u {fresh
1979 For each constraint containing the dereference, we also do the same
1982 We then compute SCC's in the graph and unify nodes in the same SCC,
1985 For each non-collapsed node x:
1986 Visit all unvisited explicit incoming edges.
1987 Ignoring all non-pointers, set pts(x) = Union of pts(a) for y
1989 Lookup the equivalence class for pts(x).
1990 If we found one, equivalence_class(x) = found class.
1991 Otherwise, equivalence_class(x) = new class, and new_class is
1992 added to the lookup table.
1994 All direct nodes with the same equivalence class can be replaced
1995 with a single representative node.
1996 All unlabeled nodes (label == 0) are not pointers and all edges
1997 involving them can be eliminated.
1998 We perform these optimizations during rewrite_constraints
2000 In addition to pointer equivalence class finding, we also perform
2001 location equivalence class finding. This is the set of variables
2002 that always appear together in points-to sets. We use this to
2003 compress the size of the points-to sets. */
2005 /* Current maximum pointer equivalence class id. */
2006 static int pointer_equiv_class
;
2008 /* Current maximum location equivalence class id. */
2009 static int location_equiv_class
;
2011 /* Recursive routine to find strongly connected components in GRAPH,
2012 and label it's nodes with DFS numbers. */
2015 condense_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
2019 unsigned int my_dfs
;
2021 gcc_assert (si
->node_mapping
[n
] == n
);
2022 SET_BIT (si
->visited
, n
);
2023 si
->dfs
[n
] = si
->current_index
++;
2024 my_dfs
= si
->dfs
[n
];
2026 /* Visit all the successors. */
2027 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[n
], 0, i
, bi
)
2029 unsigned int w
= si
->node_mapping
[i
];
2031 if (TEST_BIT (si
->deleted
, w
))
2034 if (!TEST_BIT (si
->visited
, w
))
2035 condense_visit (graph
, si
, w
);
2037 unsigned int t
= si
->node_mapping
[w
];
2038 unsigned int nnode
= si
->node_mapping
[n
];
2039 gcc_assert (nnode
== n
);
2041 if (si
->dfs
[t
] < si
->dfs
[nnode
])
2042 si
->dfs
[n
] = si
->dfs
[t
];
2046 /* Visit all the implicit predecessors. */
2047 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->implicit_preds
[n
], 0, i
, bi
)
2049 unsigned int w
= si
->node_mapping
[i
];
2051 if (TEST_BIT (si
->deleted
, w
))
2054 if (!TEST_BIT (si
->visited
, w
))
2055 condense_visit (graph
, si
, w
);
2057 unsigned int t
= si
->node_mapping
[w
];
2058 unsigned int nnode
= si
->node_mapping
[n
];
2059 gcc_assert (nnode
== n
);
2061 if (si
->dfs
[t
] < si
->dfs
[nnode
])
2062 si
->dfs
[n
] = si
->dfs
[t
];
2066 /* See if any components have been identified. */
2067 if (si
->dfs
[n
] == my_dfs
)
2069 while (VEC_length (unsigned, si
->scc_stack
) != 0
2070 && si
->dfs
[VEC_last (unsigned, si
->scc_stack
)] >= my_dfs
)
2072 unsigned int w
= VEC_pop (unsigned, si
->scc_stack
);
2073 si
->node_mapping
[w
] = n
;
2075 if (!TEST_BIT (graph
->direct_nodes
, w
))
2076 RESET_BIT (graph
->direct_nodes
, n
);
2078 /* Unify our nodes. */
2079 if (graph
->preds
[w
])
2081 if (!graph
->preds
[n
])
2082 graph
->preds
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2083 bitmap_ior_into (graph
->preds
[n
], graph
->preds
[w
]);
2085 if (graph
->implicit_preds
[w
])
2087 if (!graph
->implicit_preds
[n
])
2088 graph
->implicit_preds
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2089 bitmap_ior_into (graph
->implicit_preds
[n
],
2090 graph
->implicit_preds
[w
]);
2092 if (graph
->points_to
[w
])
2094 if (!graph
->points_to
[n
])
2095 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2096 bitmap_ior_into (graph
->points_to
[n
],
2097 graph
->points_to
[w
]);
2100 SET_BIT (si
->deleted
, n
);
2103 VEC_safe_push (unsigned, heap
, si
->scc_stack
, n
);
2106 /* Label pointer equivalences. */
2109 label_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
2113 SET_BIT (si
->visited
, n
);
2115 if (!graph
->points_to
[n
])
2116 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2118 /* Label and union our incoming edges's points to sets. */
2119 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[n
], 0, i
, bi
)
2121 unsigned int w
= si
->node_mapping
[i
];
2122 if (!TEST_BIT (si
->visited
, w
))
2123 label_visit (graph
, si
, w
);
2125 /* Skip unused edges */
2126 if (w
== n
|| graph
->pointer_label
[w
] == 0)
2129 if (graph
->points_to
[w
])
2130 bitmap_ior_into(graph
->points_to
[n
], graph
->points_to
[w
]);
2132 /* Indirect nodes get fresh variables. */
2133 if (!TEST_BIT (graph
->direct_nodes
, n
))
2134 bitmap_set_bit (graph
->points_to
[n
], FIRST_REF_NODE
+ n
);
2136 if (!bitmap_empty_p (graph
->points_to
[n
]))
2138 unsigned int label
= equiv_class_lookup (pointer_equiv_class_table
,
2139 graph
->points_to
[n
]);
2142 label
= pointer_equiv_class
++;
2143 equiv_class_add (pointer_equiv_class_table
,
2144 label
, graph
->points_to
[n
]);
2146 graph
->pointer_label
[n
] = label
;
2150 /* Perform offline variable substitution, discovering equivalence
2151 classes, and eliminating non-pointer variables. */
2153 static struct scc_info
*
2154 perform_var_substitution (constraint_graph_t graph
)
2157 unsigned int size
= graph
->size
;
2158 struct scc_info
*si
= init_scc_info (size
);
2160 bitmap_obstack_initialize (&iteration_obstack
);
2161 pointer_equiv_class_table
= htab_create (511, equiv_class_label_hash
,
2162 equiv_class_label_eq
, free
);
2163 location_equiv_class_table
= htab_create (511, equiv_class_label_hash
,
2164 equiv_class_label_eq
, free
);
2165 pointer_equiv_class
= 1;
2166 location_equiv_class
= 1;
2168 /* Condense the nodes, which means to find SCC's, count incoming
2169 predecessors, and unite nodes in SCC's. */
2170 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2171 if (!TEST_BIT (si
->visited
, si
->node_mapping
[i
]))
2172 condense_visit (graph
, si
, si
->node_mapping
[i
]);
2174 sbitmap_zero (si
->visited
);
2175 /* Actually the label the nodes for pointer equivalences */
2176 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2177 if (!TEST_BIT (si
->visited
, si
->node_mapping
[i
]))
2178 label_visit (graph
, si
, si
->node_mapping
[i
]);
2180 /* Calculate location equivalence labels. */
2181 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2188 if (!graph
->pointed_by
[i
])
2190 pointed_by
= BITMAP_ALLOC (&iteration_obstack
);
2192 /* Translate the pointed-by mapping for pointer equivalence
2194 EXECUTE_IF_SET_IN_BITMAP (graph
->pointed_by
[i
], 0, j
, bi
)
2196 bitmap_set_bit (pointed_by
,
2197 graph
->pointer_label
[si
->node_mapping
[j
]]);
2199 /* The original pointed_by is now dead. */
2200 BITMAP_FREE (graph
->pointed_by
[i
]);
2202 /* Look up the location equivalence label if one exists, or make
2204 label
= equiv_class_lookup (location_equiv_class_table
,
2208 label
= location_equiv_class
++;
2209 equiv_class_add (location_equiv_class_table
,
2214 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2215 fprintf (dump_file
, "Found location equivalence for node %s\n",
2216 get_varinfo (i
)->name
);
2217 BITMAP_FREE (pointed_by
);
2219 graph
->loc_label
[i
] = label
;
2223 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2224 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2226 bool direct_node
= TEST_BIT (graph
->direct_nodes
, i
);
2228 "Equivalence classes for %s node id %d:%s are pointer: %d"
2230 direct_node
? "Direct node" : "Indirect node", i
,
2231 get_varinfo (i
)->name
,
2232 graph
->pointer_label
[si
->node_mapping
[i
]],
2233 graph
->loc_label
[si
->node_mapping
[i
]]);
2236 /* Quickly eliminate our non-pointer variables. */
2238 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2240 unsigned int node
= si
->node_mapping
[i
];
2242 if (graph
->pointer_label
[node
] == 0)
2244 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2246 "%s is a non-pointer variable, eliminating edges.\n",
2247 get_varinfo (node
)->name
);
2248 stats
.nonpointer_vars
++;
2249 clear_edges_for_node (graph
, node
);
2256 /* Free information that was only necessary for variable
2260 free_var_substitution_info (struct scc_info
*si
)
2263 free (graph
->pointer_label
);
2264 free (graph
->loc_label
);
2265 free (graph
->pointed_by
);
2266 free (graph
->points_to
);
2267 free (graph
->eq_rep
);
2268 sbitmap_free (graph
->direct_nodes
);
2269 htab_delete (pointer_equiv_class_table
);
2270 htab_delete (location_equiv_class_table
);
2271 bitmap_obstack_release (&iteration_obstack
);
2274 /* Return an existing node that is equivalent to NODE, which has
2275 equivalence class LABEL, if one exists. Return NODE otherwise. */
2278 find_equivalent_node (constraint_graph_t graph
,
2279 unsigned int node
, unsigned int label
)
2281 /* If the address version of this variable is unused, we can
2282 substitute it for anything else with the same label.
2283 Otherwise, we know the pointers are equivalent, but not the
2284 locations, and we can unite them later. */
2286 if (!bitmap_bit_p (graph
->address_taken
, node
))
2288 gcc_assert (label
< graph
->size
);
2290 if (graph
->eq_rep
[label
] != -1)
2292 /* Unify the two variables since we know they are equivalent. */
2293 if (unite (graph
->eq_rep
[label
], node
))
2294 unify_nodes (graph
, graph
->eq_rep
[label
], node
, false);
2295 return graph
->eq_rep
[label
];
2299 graph
->eq_rep
[label
] = node
;
2300 graph
->pe_rep
[label
] = node
;
2305 gcc_assert (label
< graph
->size
);
2306 graph
->pe
[node
] = label
;
2307 if (graph
->pe_rep
[label
] == -1)
2308 graph
->pe_rep
[label
] = node
;
2314 /* Unite pointer equivalent but not location equivalent nodes in
2315 GRAPH. This may only be performed once variable substitution is
2319 unite_pointer_equivalences (constraint_graph_t graph
)
2323 /* Go through the pointer equivalences and unite them to their
2324 representative, if they aren't already. */
2325 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2327 unsigned int label
= graph
->pe
[i
];
2330 int label_rep
= graph
->pe_rep
[label
];
2332 if (label_rep
== -1)
2335 label_rep
= find (label_rep
);
2336 if (label_rep
>= 0 && unite (label_rep
, find (i
)))
2337 unify_nodes (graph
, label_rep
, i
, false);
2342 /* Move complex constraints to the GRAPH nodes they belong to. */
2345 move_complex_constraints (constraint_graph_t graph
)
2350 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
2354 struct constraint_expr lhs
= c
->lhs
;
2355 struct constraint_expr rhs
= c
->rhs
;
2357 if (lhs
.type
== DEREF
)
2359 insert_into_complex (graph
, lhs
.var
, c
);
2361 else if (rhs
.type
== DEREF
)
2363 if (!(get_varinfo (lhs
.var
)->is_special_var
))
2364 insert_into_complex (graph
, rhs
.var
, c
);
2366 else if (rhs
.type
!= ADDRESSOF
&& lhs
.var
> anything_id
2367 && (lhs
.offset
!= 0 || rhs
.offset
!= 0))
2369 insert_into_complex (graph
, rhs
.var
, c
);
2376 /* Optimize and rewrite complex constraints while performing
2377 collapsing of equivalent nodes. SI is the SCC_INFO that is the
2378 result of perform_variable_substitution. */
2381 rewrite_constraints (constraint_graph_t graph
,
2382 struct scc_info
*si
)
2388 for (j
= 0; j
< graph
->size
; j
++)
2389 gcc_assert (find (j
) == j
);
2391 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
2393 struct constraint_expr lhs
= c
->lhs
;
2394 struct constraint_expr rhs
= c
->rhs
;
2395 unsigned int lhsvar
= find (lhs
.var
);
2396 unsigned int rhsvar
= find (rhs
.var
);
2397 unsigned int lhsnode
, rhsnode
;
2398 unsigned int lhslabel
, rhslabel
;
2400 lhsnode
= si
->node_mapping
[lhsvar
];
2401 rhsnode
= si
->node_mapping
[rhsvar
];
2402 lhslabel
= graph
->pointer_label
[lhsnode
];
2403 rhslabel
= graph
->pointer_label
[rhsnode
];
2405 /* See if it is really a non-pointer variable, and if so, ignore
2409 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2412 fprintf (dump_file
, "%s is a non-pointer variable,"
2413 "ignoring constraint:",
2414 get_varinfo (lhs
.var
)->name
);
2415 dump_constraint (dump_file
, c
);
2416 fprintf (dump_file
, "\n");
2418 VEC_replace (constraint_t
, constraints
, i
, NULL
);
2424 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2427 fprintf (dump_file
, "%s is a non-pointer variable,"
2428 "ignoring constraint:",
2429 get_varinfo (rhs
.var
)->name
);
2430 dump_constraint (dump_file
, c
);
2431 fprintf (dump_file
, "\n");
2433 VEC_replace (constraint_t
, constraints
, i
, NULL
);
2437 lhsvar
= find_equivalent_node (graph
, lhsvar
, lhslabel
);
2438 rhsvar
= find_equivalent_node (graph
, rhsvar
, rhslabel
);
2439 c
->lhs
.var
= lhsvar
;
2440 c
->rhs
.var
= rhsvar
;
2445 /* Eliminate indirect cycles involving NODE. Return true if NODE was
2446 part of an SCC, false otherwise. */
2449 eliminate_indirect_cycles (unsigned int node
)
2451 if (graph
->indirect_cycles
[node
] != -1
2452 && !bitmap_empty_p (get_varinfo (node
)->solution
))
2455 VEC(unsigned,heap
) *queue
= NULL
;
2457 unsigned int to
= find (graph
->indirect_cycles
[node
]);
2460 /* We can't touch the solution set and call unify_nodes
2461 at the same time, because unify_nodes is going to do
2462 bitmap unions into it. */
2464 EXECUTE_IF_SET_IN_BITMAP (get_varinfo (node
)->solution
, 0, i
, bi
)
2466 if (find (i
) == i
&& i
!= to
)
2469 VEC_safe_push (unsigned, heap
, queue
, i
);
2474 VEC_iterate (unsigned, queue
, queuepos
, i
);
2477 unify_nodes (graph
, to
, i
, true);
2479 VEC_free (unsigned, heap
, queue
);
2485 /* Solve the constraint graph GRAPH using our worklist solver.
2486 This is based on the PW* family of solvers from the "Efficient Field
2487 Sensitive Pointer Analysis for C" paper.
2488 It works by iterating over all the graph nodes, processing the complex
2489 constraints and propagating the copy constraints, until everything stops
2490 changed. This corresponds to steps 6-8 in the solving list given above. */
2493 solve_graph (constraint_graph_t graph
)
2495 unsigned int size
= graph
->size
;
2499 changed
= BITMAP_ALLOC (NULL
);
2501 /* Mark all initial non-collapsed nodes as changed. */
2502 for (i
= 0; i
< size
; i
++)
2504 varinfo_t ivi
= get_varinfo (i
);
2505 if (find (i
) == i
&& !bitmap_empty_p (ivi
->solution
)
2506 && ((graph
->succs
[i
] && !bitmap_empty_p (graph
->succs
[i
]))
2507 || VEC_length (constraint_t
, graph
->complex[i
]) > 0))
2508 bitmap_set_bit (changed
, i
);
2511 /* Allocate a bitmap to be used to store the changed bits. */
2512 pts
= BITMAP_ALLOC (&pta_obstack
);
2514 while (!bitmap_empty_p (changed
))
2517 struct topo_info
*ti
= init_topo_info ();
2520 bitmap_obstack_initialize (&iteration_obstack
);
2522 compute_topo_order (graph
, ti
);
2524 while (VEC_length (unsigned, ti
->topo_order
) != 0)
2527 i
= VEC_pop (unsigned, ti
->topo_order
);
2529 /* If this variable is not a representative, skip it. */
2533 /* In certain indirect cycle cases, we may merge this
2534 variable to another. */
2535 if (eliminate_indirect_cycles (i
) && find (i
) != i
)
2538 /* If the node has changed, we need to process the
2539 complex constraints and outgoing edges again. */
2540 if (bitmap_clear_bit (changed
, i
))
2545 VEC(constraint_t
,heap
) *complex = graph
->complex[i
];
2546 varinfo_t vi
= get_varinfo (i
);
2547 bool solution_empty
;
2549 /* Compute the changed set of solution bits. */
2550 if (vi
->oldsolution
)
2551 bitmap_and_compl (pts
, vi
->solution
, vi
->oldsolution
);
2553 bitmap_copy (pts
, vi
->solution
);
2555 if (bitmap_empty_p (pts
))
2558 if (vi
->oldsolution
)
2559 bitmap_ior_into (vi
->oldsolution
, pts
);
2562 vi
->oldsolution
= BITMAP_ALLOC (&oldpta_obstack
);
2563 bitmap_copy (vi
->oldsolution
, pts
);
2566 solution
= vi
->solution
;
2567 solution_empty
= bitmap_empty_p (solution
);
2569 /* Process the complex constraints */
2570 FOR_EACH_VEC_ELT (constraint_t
, complex, j
, c
)
2572 /* XXX: This is going to unsort the constraints in
2573 some cases, which will occasionally add duplicate
2574 constraints during unification. This does not
2575 affect correctness. */
2576 c
->lhs
.var
= find (c
->lhs
.var
);
2577 c
->rhs
.var
= find (c
->rhs
.var
);
2579 /* The only complex constraint that can change our
2580 solution to non-empty, given an empty solution,
2581 is a constraint where the lhs side is receiving
2582 some set from elsewhere. */
2583 if (!solution_empty
|| c
->lhs
.type
!= DEREF
)
2584 do_complex_constraint (graph
, c
, pts
);
2587 solution_empty
= bitmap_empty_p (solution
);
2589 if (!solution_empty
)
2592 unsigned eff_escaped_id
= find (escaped_id
);
2594 /* Propagate solution to all successors. */
2595 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[i
],
2601 unsigned int to
= find (j
);
2602 tmp
= get_varinfo (to
)->solution
;
2605 /* Don't try to propagate to ourselves. */
2609 /* If we propagate from ESCAPED use ESCAPED as
2611 if (i
== eff_escaped_id
)
2612 flag
= bitmap_set_bit (tmp
, escaped_id
);
2614 flag
= set_union_with_increment (tmp
, pts
, 0);
2618 get_varinfo (to
)->solution
= tmp
;
2619 bitmap_set_bit (changed
, to
);
2625 free_topo_info (ti
);
2626 bitmap_obstack_release (&iteration_obstack
);
2630 BITMAP_FREE (changed
);
2631 bitmap_obstack_release (&oldpta_obstack
);
2634 /* Map from trees to variable infos. */
2635 static struct pointer_map_t
*vi_for_tree
;
2638 /* Insert ID as the variable id for tree T in the vi_for_tree map. */
2641 insert_vi_for_tree (tree t
, varinfo_t vi
)
2643 void **slot
= pointer_map_insert (vi_for_tree
, t
);
2645 gcc_assert (*slot
== NULL
);
2649 /* Find the variable info for tree T in VI_FOR_TREE. If T does not
2650 exist in the map, return NULL, otherwise, return the varinfo we found. */
2653 lookup_vi_for_tree (tree t
)
2655 void **slot
= pointer_map_contains (vi_for_tree
, t
);
2659 return (varinfo_t
) *slot
;
2662 /* Return a printable name for DECL */
2665 alias_get_name (tree decl
)
2669 int num_printed
= 0;
2671 if (DECL_ASSEMBLER_NAME_SET_P (decl
))
2672 res
= IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl
));
2674 res
= get_name (decl
);
2682 if (TREE_CODE (decl
) == SSA_NAME
)
2684 num_printed
= asprintf (&temp
, "%s_%u",
2685 alias_get_name (SSA_NAME_VAR (decl
)),
2686 SSA_NAME_VERSION (decl
));
2688 else if (DECL_P (decl
))
2690 num_printed
= asprintf (&temp
, "D.%u", DECL_UID (decl
));
2692 if (num_printed
> 0)
2694 res
= ggc_strdup (temp
);
2700 /* Find the variable id for tree T in the map.
2701 If T doesn't exist in the map, create an entry for it and return it. */
2704 get_vi_for_tree (tree t
)
2706 void **slot
= pointer_map_contains (vi_for_tree
, t
);
2708 return get_varinfo (create_variable_info_for (t
, alias_get_name (t
)));
2710 return (varinfo_t
) *slot
;
2713 /* Get a scalar constraint expression for a new temporary variable. */
2715 static struct constraint_expr
2716 new_scalar_tmp_constraint_exp (const char *name
)
2718 struct constraint_expr tmp
;
2721 vi
= new_var_info (NULL_TREE
, name
);
2725 vi
->is_full_var
= 1;
2734 /* Get a constraint expression vector from an SSA_VAR_P node.
2735 If address_p is true, the result will be taken its address of. */
2738 get_constraint_for_ssa_var (tree t
, VEC(ce_s
, heap
) **results
, bool address_p
)
2740 struct constraint_expr cexpr
;
2743 /* We allow FUNCTION_DECLs here even though it doesn't make much sense. */
2744 gcc_assert (SSA_VAR_P (t
) || DECL_P (t
));
2746 /* For parameters, get at the points-to set for the actual parm
2748 if (TREE_CODE (t
) == SSA_NAME
2749 && (TREE_CODE (SSA_NAME_VAR (t
)) == PARM_DECL
2750 || TREE_CODE (SSA_NAME_VAR (t
)) == RESULT_DECL
)
2751 && SSA_NAME_IS_DEFAULT_DEF (t
))
2753 get_constraint_for_ssa_var (SSA_NAME_VAR (t
), results
, address_p
);
2757 /* For global variables resort to the alias target. */
2758 if (TREE_CODE (t
) == VAR_DECL
2759 && (TREE_STATIC (t
) || DECL_EXTERNAL (t
)))
2761 struct varpool_node
*node
= varpool_get_node (t
);
2762 if (node
&& node
->alias
)
2764 node
= varpool_variable_node (node
, NULL
);
2769 vi
= get_vi_for_tree (t
);
2771 cexpr
.type
= SCALAR
;
2773 /* If we determine the result is "anything", and we know this is readonly,
2774 say it points to readonly memory instead. */
2775 if (cexpr
.var
== anything_id
&& TREE_READONLY (t
))
2778 cexpr
.type
= ADDRESSOF
;
2779 cexpr
.var
= readonly_id
;
2782 /* If we are not taking the address of the constraint expr, add all
2783 sub-fiels of the variable as well. */
2785 && !vi
->is_full_var
)
2787 for (; vi
; vi
= vi
->next
)
2790 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
2795 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
2798 /* Process constraint T, performing various simplifications and then
2799 adding it to our list of overall constraints. */
2802 process_constraint (constraint_t t
)
2804 struct constraint_expr rhs
= t
->rhs
;
2805 struct constraint_expr lhs
= t
->lhs
;
2807 gcc_assert (rhs
.var
< VEC_length (varinfo_t
, varmap
));
2808 gcc_assert (lhs
.var
< VEC_length (varinfo_t
, varmap
));
2810 /* If we didn't get any useful constraint from the lhs we get
2811 &ANYTHING as fallback from get_constraint_for. Deal with
2812 it here by turning it into *ANYTHING. */
2813 if (lhs
.type
== ADDRESSOF
2814 && lhs
.var
== anything_id
)
2817 /* ADDRESSOF on the lhs is invalid. */
2818 gcc_assert (lhs
.type
!= ADDRESSOF
);
2820 /* We shouldn't add constraints from things that cannot have pointers.
2821 It's not completely trivial to avoid in the callers, so do it here. */
2822 if (rhs
.type
!= ADDRESSOF
2823 && !get_varinfo (rhs
.var
)->may_have_pointers
)
2826 /* Likewise adding to the solution of a non-pointer var isn't useful. */
2827 if (!get_varinfo (lhs
.var
)->may_have_pointers
)
2830 /* This can happen in our IR with things like n->a = *p */
2831 if (rhs
.type
== DEREF
&& lhs
.type
== DEREF
&& rhs
.var
!= anything_id
)
2833 /* Split into tmp = *rhs, *lhs = tmp */
2834 struct constraint_expr tmplhs
;
2835 tmplhs
= new_scalar_tmp_constraint_exp ("doubledereftmp");
2836 process_constraint (new_constraint (tmplhs
, rhs
));
2837 process_constraint (new_constraint (lhs
, tmplhs
));
2839 else if (rhs
.type
== ADDRESSOF
&& lhs
.type
== DEREF
)
2841 /* Split into tmp = &rhs, *lhs = tmp */
2842 struct constraint_expr tmplhs
;
2843 tmplhs
= new_scalar_tmp_constraint_exp ("derefaddrtmp");
2844 process_constraint (new_constraint (tmplhs
, rhs
));
2845 process_constraint (new_constraint (lhs
, tmplhs
));
2849 gcc_assert (rhs
.type
!= ADDRESSOF
|| rhs
.offset
== 0);
2850 VEC_safe_push (constraint_t
, heap
, constraints
, t
);
2855 /* Return the position, in bits, of FIELD_DECL from the beginning of its
2858 static HOST_WIDE_INT
2859 bitpos_of_field (const tree fdecl
)
2861 if (!host_integerp (DECL_FIELD_OFFSET (fdecl
), 0)
2862 || !host_integerp (DECL_FIELD_BIT_OFFSET (fdecl
), 0))
2865 return (TREE_INT_CST_LOW (DECL_FIELD_OFFSET (fdecl
)) * BITS_PER_UNIT
2866 + TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fdecl
)));
2870 /* Get constraint expressions for offsetting PTR by OFFSET. Stores the
2871 resulting constraint expressions in *RESULTS. */
2874 get_constraint_for_ptr_offset (tree ptr
, tree offset
,
2875 VEC (ce_s
, heap
) **results
)
2877 struct constraint_expr c
;
2879 HOST_WIDE_INT rhsoffset
;
2881 /* If we do not do field-sensitive PTA adding offsets to pointers
2882 does not change the points-to solution. */
2883 if (!use_field_sensitive
)
2885 get_constraint_for_rhs (ptr
, results
);
2889 /* If the offset is not a non-negative integer constant that fits
2890 in a HOST_WIDE_INT, we have to fall back to a conservative
2891 solution which includes all sub-fields of all pointed-to
2892 variables of ptr. */
2893 if (offset
== NULL_TREE
2894 || TREE_CODE (offset
) != INTEGER_CST
)
2895 rhsoffset
= UNKNOWN_OFFSET
;
2898 /* Sign-extend the offset. */
2900 = double_int_sext (tree_to_double_int (offset
),
2901 TYPE_PRECISION (TREE_TYPE (offset
)));
2902 if (!double_int_fits_in_shwi_p (soffset
))
2903 rhsoffset
= UNKNOWN_OFFSET
;
2906 /* Make sure the bit-offset also fits. */
2907 HOST_WIDE_INT rhsunitoffset
= soffset
.low
;
2908 rhsoffset
= rhsunitoffset
* BITS_PER_UNIT
;
2909 if (rhsunitoffset
!= rhsoffset
/ BITS_PER_UNIT
)
2910 rhsoffset
= UNKNOWN_OFFSET
;
2914 get_constraint_for_rhs (ptr
, results
);
2918 /* As we are eventually appending to the solution do not use
2919 VEC_iterate here. */
2920 n
= VEC_length (ce_s
, *results
);
2921 for (j
= 0; j
< n
; j
++)
2924 c
= *VEC_index (ce_s
, *results
, j
);
2925 curr
= get_varinfo (c
.var
);
2927 if (c
.type
== ADDRESSOF
2928 /* If this varinfo represents a full variable just use it. */
2929 && curr
->is_full_var
)
2931 else if (c
.type
== ADDRESSOF
2932 /* If we do not know the offset add all subfields. */
2933 && rhsoffset
== UNKNOWN_OFFSET
)
2935 varinfo_t temp
= lookup_vi_for_tree (curr
->decl
);
2938 struct constraint_expr c2
;
2940 c2
.type
= ADDRESSOF
;
2942 if (c2
.var
!= c
.var
)
2943 VEC_safe_push (ce_s
, heap
, *results
, &c2
);
2948 else if (c
.type
== ADDRESSOF
)
2951 unsigned HOST_WIDE_INT offset
= curr
->offset
+ rhsoffset
;
2953 /* Search the sub-field which overlaps with the
2954 pointed-to offset. If the result is outside of the variable
2955 we have to provide a conservative result, as the variable is
2956 still reachable from the resulting pointer (even though it
2957 technically cannot point to anything). The last and first
2958 sub-fields are such conservative results.
2959 ??? If we always had a sub-field for &object + 1 then
2960 we could represent this in a more precise way. */
2962 && curr
->offset
< offset
)
2964 temp
= first_or_preceding_vi_for_offset (curr
, offset
);
2966 /* If the found variable is not exactly at the pointed to
2967 result, we have to include the next variable in the
2968 solution as well. Otherwise two increments by offset / 2
2969 do not result in the same or a conservative superset
2971 if (temp
->offset
!= offset
2972 && temp
->next
!= NULL
)
2974 struct constraint_expr c2
;
2975 c2
.var
= temp
->next
->id
;
2976 c2
.type
= ADDRESSOF
;
2978 VEC_safe_push (ce_s
, heap
, *results
, &c2
);
2984 c
.offset
= rhsoffset
;
2986 VEC_replace (ce_s
, *results
, j
, &c
);
2991 /* Given a COMPONENT_REF T, return the constraint_expr vector for it.
2992 If address_p is true the result will be taken its address of.
2993 If lhs_p is true then the constraint expression is assumed to be used
2997 get_constraint_for_component_ref (tree t
, VEC(ce_s
, heap
) **results
,
2998 bool address_p
, bool lhs_p
)
3001 HOST_WIDE_INT bitsize
= -1;
3002 HOST_WIDE_INT bitmaxsize
= -1;
3003 HOST_WIDE_INT bitpos
;
3005 struct constraint_expr
*result
;
3007 /* Some people like to do cute things like take the address of
3010 while (handled_component_p (forzero
)
3011 || INDIRECT_REF_P (forzero
)
3012 || TREE_CODE (forzero
) == MEM_REF
)
3013 forzero
= TREE_OPERAND (forzero
, 0);
3015 if (CONSTANT_CLASS_P (forzero
) && integer_zerop (forzero
))
3017 struct constraint_expr temp
;
3020 temp
.var
= integer_id
;
3022 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3026 /* Handle type-punning through unions. If we are extracting a pointer
3027 from a union via a possibly type-punning access that pointer
3028 points to anything, similar to a conversion of an integer to
3034 TREE_CODE (u
) == COMPONENT_REF
|| TREE_CODE (u
) == ARRAY_REF
;
3035 u
= TREE_OPERAND (u
, 0))
3036 if (TREE_CODE (u
) == COMPONENT_REF
3037 && TREE_CODE (TREE_TYPE (TREE_OPERAND (u
, 0))) == UNION_TYPE
)
3039 struct constraint_expr temp
;
3042 temp
.var
= anything_id
;
3043 temp
.type
= ADDRESSOF
;
3044 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3049 t
= get_ref_base_and_extent (t
, &bitpos
, &bitsize
, &bitmaxsize
);
3051 /* Pretend to take the address of the base, we'll take care of
3052 adding the required subset of sub-fields below. */
3053 get_constraint_for_1 (t
, results
, true, lhs_p
);
3054 gcc_assert (VEC_length (ce_s
, *results
) == 1);
3055 result
= VEC_last (ce_s
, *results
);
3057 if (result
->type
== SCALAR
3058 && get_varinfo (result
->var
)->is_full_var
)
3059 /* For single-field vars do not bother about the offset. */
3061 else if (result
->type
== SCALAR
)
3063 /* In languages like C, you can access one past the end of an
3064 array. You aren't allowed to dereference it, so we can
3065 ignore this constraint. When we handle pointer subtraction,
3066 we may have to do something cute here. */
3068 if ((unsigned HOST_WIDE_INT
)bitpos
< get_varinfo (result
->var
)->fullsize
3071 /* It's also not true that the constraint will actually start at the
3072 right offset, it may start in some padding. We only care about
3073 setting the constraint to the first actual field it touches, so
3075 struct constraint_expr cexpr
= *result
;
3077 VEC_pop (ce_s
, *results
);
3079 for (curr
= get_varinfo (cexpr
.var
); curr
; curr
= curr
->next
)
3081 if (ranges_overlap_p (curr
->offset
, curr
->size
,
3082 bitpos
, bitmaxsize
))
3084 cexpr
.var
= curr
->id
;
3085 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
3090 /* If we are going to take the address of this field then
3091 to be able to compute reachability correctly add at least
3092 the last field of the variable. */
3094 && VEC_length (ce_s
, *results
) == 0)
3096 curr
= get_varinfo (cexpr
.var
);
3097 while (curr
->next
!= NULL
)
3099 cexpr
.var
= curr
->id
;
3100 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
3102 else if (VEC_length (ce_s
, *results
) == 0)
3103 /* Assert that we found *some* field there. The user couldn't be
3104 accessing *only* padding. */
3105 /* Still the user could access one past the end of an array
3106 embedded in a struct resulting in accessing *only* padding. */
3107 /* Or accessing only padding via type-punning to a type
3108 that has a filed just in padding space. */
3110 cexpr
.type
= SCALAR
;
3111 cexpr
.var
= anything_id
;
3113 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
3116 else if (bitmaxsize
== 0)
3118 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3119 fprintf (dump_file
, "Access to zero-sized part of variable,"
3123 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3124 fprintf (dump_file
, "Access to past the end of variable, ignoring\n");
3126 else if (result
->type
== DEREF
)
3128 /* If we do not know exactly where the access goes say so. Note
3129 that only for non-structure accesses we know that we access
3130 at most one subfiled of any variable. */
3132 || bitsize
!= bitmaxsize
3133 || AGGREGATE_TYPE_P (TREE_TYPE (orig_t
))
3134 || result
->offset
== UNKNOWN_OFFSET
)
3135 result
->offset
= UNKNOWN_OFFSET
;
3137 result
->offset
+= bitpos
;
3139 else if (result
->type
== ADDRESSOF
)
3141 /* We can end up here for component references on a
3142 VIEW_CONVERT_EXPR <>(&foobar). */
3143 result
->type
= SCALAR
;
3144 result
->var
= anything_id
;
3152 /* Dereference the constraint expression CONS, and return the result.
3153 DEREF (ADDRESSOF) = SCALAR
3154 DEREF (SCALAR) = DEREF
3155 DEREF (DEREF) = (temp = DEREF1; result = DEREF(temp))
3156 This is needed so that we can handle dereferencing DEREF constraints. */
3159 do_deref (VEC (ce_s
, heap
) **constraints
)
3161 struct constraint_expr
*c
;
3164 FOR_EACH_VEC_ELT (ce_s
, *constraints
, i
, c
)
3166 if (c
->type
== SCALAR
)
3168 else if (c
->type
== ADDRESSOF
)
3170 else if (c
->type
== DEREF
)
3172 struct constraint_expr tmplhs
;
3173 tmplhs
= new_scalar_tmp_constraint_exp ("dereftmp");
3174 process_constraint (new_constraint (tmplhs
, *c
));
3175 c
->var
= tmplhs
.var
;
3182 /* Given a tree T, return the constraint expression for taking the
3186 get_constraint_for_address_of (tree t
, VEC (ce_s
, heap
) **results
)
3188 struct constraint_expr
*c
;
3191 get_constraint_for_1 (t
, results
, true, true);
3193 FOR_EACH_VEC_ELT (ce_s
, *results
, i
, c
)
3195 if (c
->type
== DEREF
)
3198 c
->type
= ADDRESSOF
;
3202 /* Given a tree T, return the constraint expression for it. */
3205 get_constraint_for_1 (tree t
, VEC (ce_s
, heap
) **results
, bool address_p
,
3208 struct constraint_expr temp
;
3210 /* x = integer is all glommed to a single variable, which doesn't
3211 point to anything by itself. That is, of course, unless it is an
3212 integer constant being treated as a pointer, in which case, we
3213 will return that this is really the addressof anything. This
3214 happens below, since it will fall into the default case. The only
3215 case we know something about an integer treated like a pointer is
3216 when it is the NULL pointer, and then we just say it points to
3219 Do not do that if -fno-delete-null-pointer-checks though, because
3220 in that case *NULL does not fail, so it _should_ alias *anything.
3221 It is not worth adding a new option or renaming the existing one,
3222 since this case is relatively obscure. */
3223 if ((TREE_CODE (t
) == INTEGER_CST
3224 && integer_zerop (t
))
3225 /* The only valid CONSTRUCTORs in gimple with pointer typed
3226 elements are zero-initializer. But in IPA mode we also
3227 process global initializers, so verify at least. */
3228 || (TREE_CODE (t
) == CONSTRUCTOR
3229 && CONSTRUCTOR_NELTS (t
) == 0))
3231 if (flag_delete_null_pointer_checks
)
3232 temp
.var
= nothing_id
;
3234 temp
.var
= nonlocal_id
;
3235 temp
.type
= ADDRESSOF
;
3237 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3241 /* String constants are read-only. */
3242 if (TREE_CODE (t
) == STRING_CST
)
3244 temp
.var
= readonly_id
;
3247 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3251 switch (TREE_CODE_CLASS (TREE_CODE (t
)))
3253 case tcc_expression
:
3255 switch (TREE_CODE (t
))
3258 get_constraint_for_address_of (TREE_OPERAND (t
, 0), results
);
3266 switch (TREE_CODE (t
))
3270 struct constraint_expr cs
;
3272 get_constraint_for_ptr_offset (TREE_OPERAND (t
, 0),
3273 TREE_OPERAND (t
, 1), results
);
3276 /* If we are not taking the address then make sure to process
3277 all subvariables we might access. */
3281 cs
= *VEC_last (ce_s
, *results
);
3282 if (cs
.type
== DEREF
)
3284 /* For dereferences this means we have to defer it
3286 VEC_last (ce_s
, *results
)->offset
= UNKNOWN_OFFSET
;
3289 if (cs
.type
!= SCALAR
)
3292 vi
= get_varinfo (cs
.var
);
3294 if (!vi
->is_full_var
3297 unsigned HOST_WIDE_INT size
;
3298 if (host_integerp (TYPE_SIZE (TREE_TYPE (t
)), 1))
3299 size
= TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (t
)));
3302 for (; curr
; curr
= curr
->next
)
3304 if (curr
->offset
- vi
->offset
< size
)
3307 VEC_safe_push (ce_s
, heap
, *results
, &cs
);
3316 case ARRAY_RANGE_REF
:
3318 get_constraint_for_component_ref (t
, results
, address_p
, lhs_p
);
3320 case VIEW_CONVERT_EXPR
:
3321 get_constraint_for_1 (TREE_OPERAND (t
, 0), results
, address_p
,
3324 /* We are missing handling for TARGET_MEM_REF here. */
3329 case tcc_exceptional
:
3331 switch (TREE_CODE (t
))
3335 get_constraint_for_ssa_var (t
, results
, address_p
);
3342 VEC (ce_s
, heap
) *tmp
= NULL
;
3343 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t
), i
, val
)
3345 struct constraint_expr
*rhsp
;
3347 get_constraint_for_1 (val
, &tmp
, address_p
, lhs_p
);
3348 FOR_EACH_VEC_ELT (ce_s
, tmp
, j
, rhsp
)
3349 VEC_safe_push (ce_s
, heap
, *results
, rhsp
);
3350 VEC_truncate (ce_s
, tmp
, 0);
3352 VEC_free (ce_s
, heap
, tmp
);
3353 /* We do not know whether the constructor was complete,
3354 so technically we have to add &NOTHING or &ANYTHING
3355 like we do for an empty constructor as well. */
3362 case tcc_declaration
:
3364 get_constraint_for_ssa_var (t
, results
, address_p
);
3369 /* We cannot refer to automatic variables through constants. */
3370 temp
.type
= ADDRESSOF
;
3371 temp
.var
= nonlocal_id
;
3373 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3379 /* The default fallback is a constraint from anything. */
3380 temp
.type
= ADDRESSOF
;
3381 temp
.var
= anything_id
;
3383 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3386 /* Given a gimple tree T, return the constraint expression vector for it. */
3389 get_constraint_for (tree t
, VEC (ce_s
, heap
) **results
)
3391 gcc_assert (VEC_length (ce_s
, *results
) == 0);
3393 get_constraint_for_1 (t
, results
, false, true);
3396 /* Given a gimple tree T, return the constraint expression vector for it
3397 to be used as the rhs of a constraint. */
3400 get_constraint_for_rhs (tree t
, VEC (ce_s
, heap
) **results
)
3402 gcc_assert (VEC_length (ce_s
, *results
) == 0);
3404 get_constraint_for_1 (t
, results
, false, false);
3408 /* Efficiently generates constraints from all entries in *RHSC to all
3409 entries in *LHSC. */
3412 process_all_all_constraints (VEC (ce_s
, heap
) *lhsc
, VEC (ce_s
, heap
) *rhsc
)
3414 struct constraint_expr
*lhsp
, *rhsp
;
3417 if (VEC_length (ce_s
, lhsc
) <= 1
3418 || VEC_length (ce_s
, rhsc
) <= 1)
3420 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
3421 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, rhsp
)
3422 process_constraint (new_constraint (*lhsp
, *rhsp
));
3426 struct constraint_expr tmp
;
3427 tmp
= new_scalar_tmp_constraint_exp ("allalltmp");
3428 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
3429 process_constraint (new_constraint (tmp
, *rhsp
));
3430 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
3431 process_constraint (new_constraint (*lhsp
, tmp
));
3435 /* Handle aggregate copies by expanding into copies of the respective
3436 fields of the structures. */
3439 do_structure_copy (tree lhsop
, tree rhsop
)
3441 struct constraint_expr
*lhsp
, *rhsp
;
3442 VEC (ce_s
, heap
) *lhsc
= NULL
, *rhsc
= NULL
;
3445 get_constraint_for (lhsop
, &lhsc
);
3446 get_constraint_for_rhs (rhsop
, &rhsc
);
3447 lhsp
= VEC_index (ce_s
, lhsc
, 0);
3448 rhsp
= VEC_index (ce_s
, rhsc
, 0);
3449 if (lhsp
->type
== DEREF
3450 || (lhsp
->type
== ADDRESSOF
&& lhsp
->var
== anything_id
)
3451 || rhsp
->type
== DEREF
)
3453 if (lhsp
->type
== DEREF
)
3455 gcc_assert (VEC_length (ce_s
, lhsc
) == 1);
3456 lhsp
->offset
= UNKNOWN_OFFSET
;
3458 if (rhsp
->type
== DEREF
)
3460 gcc_assert (VEC_length (ce_s
, rhsc
) == 1);
3461 rhsp
->offset
= UNKNOWN_OFFSET
;
3463 process_all_all_constraints (lhsc
, rhsc
);
3465 else if (lhsp
->type
== SCALAR
3466 && (rhsp
->type
== SCALAR
3467 || rhsp
->type
== ADDRESSOF
))
3469 HOST_WIDE_INT lhssize
, lhsmaxsize
, lhsoffset
;
3470 HOST_WIDE_INT rhssize
, rhsmaxsize
, rhsoffset
;
3472 get_ref_base_and_extent (lhsop
, &lhsoffset
, &lhssize
, &lhsmaxsize
);
3473 get_ref_base_and_extent (rhsop
, &rhsoffset
, &rhssize
, &rhsmaxsize
);
3474 for (j
= 0; VEC_iterate (ce_s
, lhsc
, j
, lhsp
);)
3476 varinfo_t lhsv
, rhsv
;
3477 rhsp
= VEC_index (ce_s
, rhsc
, k
);
3478 lhsv
= get_varinfo (lhsp
->var
);
3479 rhsv
= get_varinfo (rhsp
->var
);
3480 if (lhsv
->may_have_pointers
3481 && (lhsv
->is_full_var
3482 || rhsv
->is_full_var
3483 || ranges_overlap_p (lhsv
->offset
+ rhsoffset
, lhsv
->size
,
3484 rhsv
->offset
+ lhsoffset
, rhsv
->size
)))
3485 process_constraint (new_constraint (*lhsp
, *rhsp
));
3486 if (!rhsv
->is_full_var
3487 && (lhsv
->is_full_var
3488 || (lhsv
->offset
+ rhsoffset
+ lhsv
->size
3489 > rhsv
->offset
+ lhsoffset
+ rhsv
->size
)))
3492 if (k
>= VEC_length (ce_s
, rhsc
))
3502 VEC_free (ce_s
, heap
, lhsc
);
3503 VEC_free (ce_s
, heap
, rhsc
);
3506 /* Create constraints ID = { rhsc }. */
3509 make_constraints_to (unsigned id
, VEC(ce_s
, heap
) *rhsc
)
3511 struct constraint_expr
*c
;
3512 struct constraint_expr includes
;
3516 includes
.offset
= 0;
3517 includes
.type
= SCALAR
;
3519 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, c
)
3520 process_constraint (new_constraint (includes
, *c
));
3523 /* Create a constraint ID = OP. */
3526 make_constraint_to (unsigned id
, tree op
)
3528 VEC(ce_s
, heap
) *rhsc
= NULL
;
3529 get_constraint_for_rhs (op
, &rhsc
);
3530 make_constraints_to (id
, rhsc
);
3531 VEC_free (ce_s
, heap
, rhsc
);
3534 /* Create a constraint ID = &FROM. */
3537 make_constraint_from (varinfo_t vi
, int from
)
3539 struct constraint_expr lhs
, rhs
;
3547 rhs
.type
= ADDRESSOF
;
3548 process_constraint (new_constraint (lhs
, rhs
));
3551 /* Create a constraint ID = FROM. */
3554 make_copy_constraint (varinfo_t vi
, int from
)
3556 struct constraint_expr lhs
, rhs
;
3565 process_constraint (new_constraint (lhs
, rhs
));
3568 /* Make constraints necessary to make OP escape. */
3571 make_escape_constraint (tree op
)
3573 make_constraint_to (escaped_id
, op
);
3576 /* Add constraints to that the solution of VI is transitively closed. */
3579 make_transitive_closure_constraints (varinfo_t vi
)
3581 struct constraint_expr lhs
, rhs
;
3590 process_constraint (new_constraint (lhs
, rhs
));
3592 /* VAR = VAR + UNKNOWN; */
3598 rhs
.offset
= UNKNOWN_OFFSET
;
3599 process_constraint (new_constraint (lhs
, rhs
));
3602 /* Temporary storage for fake var decls. */
3603 struct obstack fake_var_decl_obstack
;
3605 /* Build a fake VAR_DECL acting as referrer to a DECL_UID. */
3608 build_fake_var_decl (tree type
)
3610 tree decl
= (tree
) XOBNEW (&fake_var_decl_obstack
, struct tree_var_decl
);
3611 memset (decl
, 0, sizeof (struct tree_var_decl
));
3612 TREE_SET_CODE (decl
, VAR_DECL
);
3613 TREE_TYPE (decl
) = type
;
3614 DECL_UID (decl
) = allocate_decl_uid ();
3615 SET_DECL_PT_UID (decl
, -1);
3616 layout_decl (decl
, 0);
3620 /* Create a new artificial heap variable with NAME.
3621 Return the created variable. */
3624 make_heapvar (const char *name
)
3629 heapvar
= build_fake_var_decl (ptr_type_node
);
3630 DECL_EXTERNAL (heapvar
) = 1;
3632 vi
= new_var_info (heapvar
, name
);
3633 vi
->is_artificial_var
= true;
3634 vi
->is_heap_var
= true;
3635 vi
->is_unknown_size_var
= true;
3639 vi
->is_full_var
= true;
3640 insert_vi_for_tree (heapvar
, vi
);
3645 /* Create a new artificial heap variable with NAME and make a
3646 constraint from it to LHS. Return the created variable. */
3649 make_constraint_from_heapvar (varinfo_t lhs
, const char *name
)
3651 varinfo_t vi
= make_heapvar (name
);
3652 make_constraint_from (lhs
, vi
->id
);
3657 /* Create a new artificial heap variable with NAME and make a
3658 constraint from it to LHS. Set flags according to a tag used
3659 for tracking restrict pointers. */
3662 make_constraint_from_restrict (varinfo_t lhs
, const char *name
)
3665 vi
= make_constraint_from_heapvar (lhs
, name
);
3666 vi
->is_restrict_var
= 1;
3667 vi
->is_global_var
= 0;
3668 vi
->is_special_var
= 1;
3669 vi
->may_have_pointers
= 0;
3672 /* In IPA mode there are varinfos for different aspects of reach
3673 function designator. One for the points-to set of the return
3674 value, one for the variables that are clobbered by the function,
3675 one for its uses and one for each parameter (including a single
3676 glob for remaining variadic arguments). */
3678 enum { fi_clobbers
= 1, fi_uses
= 2,
3679 fi_static_chain
= 3, fi_result
= 4, fi_parm_base
= 5 };
3681 /* Get a constraint for the requested part of a function designator FI
3682 when operating in IPA mode. */
3684 static struct constraint_expr
3685 get_function_part_constraint (varinfo_t fi
, unsigned part
)
3687 struct constraint_expr c
;
3689 gcc_assert (in_ipa_mode
);
3691 if (fi
->id
== anything_id
)
3693 /* ??? We probably should have a ANYFN special variable. */
3694 c
.var
= anything_id
;
3698 else if (TREE_CODE (fi
->decl
) == FUNCTION_DECL
)
3700 varinfo_t ai
= first_vi_for_offset (fi
, part
);
3704 c
.var
= anything_id
;
3718 /* For non-IPA mode, generate constraints necessary for a call on the
3722 handle_rhs_call (gimple stmt
, VEC(ce_s
, heap
) **results
)
3724 struct constraint_expr rhsc
;
3726 bool returns_uses
= false;
3728 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
3730 tree arg
= gimple_call_arg (stmt
, i
);
3731 int flags
= gimple_call_arg_flags (stmt
, i
);
3733 /* If the argument is not used we can ignore it. */
3734 if (flags
& EAF_UNUSED
)
3737 /* As we compute ESCAPED context-insensitive we do not gain
3738 any precision with just EAF_NOCLOBBER but not EAF_NOESCAPE
3739 set. The argument would still get clobbered through the
3741 ??? We might get away with less (and more precise) constraints
3742 if using a temporary for transitively closing things. */
3743 if ((flags
& EAF_NOCLOBBER
)
3744 && (flags
& EAF_NOESCAPE
))
3746 varinfo_t uses
= get_call_use_vi (stmt
);
3747 if (!(flags
& EAF_DIRECT
))
3748 make_transitive_closure_constraints (uses
);
3749 make_constraint_to (uses
->id
, arg
);
3750 returns_uses
= true;
3752 else if (flags
& EAF_NOESCAPE
)
3754 varinfo_t uses
= get_call_use_vi (stmt
);
3755 varinfo_t clobbers
= get_call_clobber_vi (stmt
);
3756 if (!(flags
& EAF_DIRECT
))
3758 make_transitive_closure_constraints (uses
);
3759 make_transitive_closure_constraints (clobbers
);
3761 make_constraint_to (uses
->id
, arg
);
3762 make_constraint_to (clobbers
->id
, arg
);
3763 returns_uses
= true;
3766 make_escape_constraint (arg
);
3769 /* If we added to the calls uses solution make sure we account for
3770 pointers to it to be returned. */
3773 rhsc
.var
= get_call_use_vi (stmt
)->id
;
3776 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3779 /* The static chain escapes as well. */
3780 if (gimple_call_chain (stmt
))
3781 make_escape_constraint (gimple_call_chain (stmt
));
3783 /* And if we applied NRV the address of the return slot escapes as well. */
3784 if (gimple_call_return_slot_opt_p (stmt
)
3785 && gimple_call_lhs (stmt
) != NULL_TREE
3786 && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt
))))
3788 VEC(ce_s
, heap
) *tmpc
= NULL
;
3789 struct constraint_expr lhsc
, *c
;
3790 get_constraint_for_address_of (gimple_call_lhs (stmt
), &tmpc
);
3791 lhsc
.var
= escaped_id
;
3794 FOR_EACH_VEC_ELT (ce_s
, tmpc
, i
, c
)
3795 process_constraint (new_constraint (lhsc
, *c
));
3796 VEC_free(ce_s
, heap
, tmpc
);
3799 /* Regular functions return nonlocal memory. */
3800 rhsc
.var
= nonlocal_id
;
3803 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3806 /* For non-IPA mode, generate constraints necessary for a call
3807 that returns a pointer and assigns it to LHS. This simply makes
3808 the LHS point to global and escaped variables. */
3811 handle_lhs_call (gimple stmt
, tree lhs
, int flags
, VEC(ce_s
, heap
) *rhsc
,
3814 VEC(ce_s
, heap
) *lhsc
= NULL
;
3816 get_constraint_for (lhs
, &lhsc
);
3817 /* If the store is to a global decl make sure to
3818 add proper escape constraints. */
3819 lhs
= get_base_address (lhs
);
3822 && is_global_var (lhs
))
3824 struct constraint_expr tmpc
;
3825 tmpc
.var
= escaped_id
;
3828 VEC_safe_push (ce_s
, heap
, lhsc
, &tmpc
);
3831 /* If the call returns an argument unmodified override the rhs
3833 flags
= gimple_call_return_flags (stmt
);
3834 if (flags
& ERF_RETURNS_ARG
3835 && (flags
& ERF_RETURN_ARG_MASK
) < gimple_call_num_args (stmt
))
3839 arg
= gimple_call_arg (stmt
, flags
& ERF_RETURN_ARG_MASK
);
3840 get_constraint_for (arg
, &rhsc
);
3841 process_all_all_constraints (lhsc
, rhsc
);
3842 VEC_free (ce_s
, heap
, rhsc
);
3844 else if (flags
& ERF_NOALIAS
)
3847 struct constraint_expr tmpc
;
3849 vi
= make_heapvar ("HEAP");
3850 /* We delay marking allocated storage global until we know if
3852 DECL_EXTERNAL (vi
->decl
) = 0;
3853 vi
->is_global_var
= 0;
3854 /* If this is not a real malloc call assume the memory was
3855 initialized and thus may point to global memory. All
3856 builtin functions with the malloc attribute behave in a sane way. */
3858 || DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_NORMAL
)
3859 make_constraint_from (vi
, nonlocal_id
);
3862 tmpc
.type
= ADDRESSOF
;
3863 VEC_safe_push (ce_s
, heap
, rhsc
, &tmpc
);
3866 process_all_all_constraints (lhsc
, rhsc
);
3868 VEC_free (ce_s
, heap
, lhsc
);
3871 /* For non-IPA mode, generate constraints necessary for a call of a
3872 const function that returns a pointer in the statement STMT. */
3875 handle_const_call (gimple stmt
, VEC(ce_s
, heap
) **results
)
3877 struct constraint_expr rhsc
;
3880 /* Treat nested const functions the same as pure functions as far
3881 as the static chain is concerned. */
3882 if (gimple_call_chain (stmt
))
3884 varinfo_t uses
= get_call_use_vi (stmt
);
3885 make_transitive_closure_constraints (uses
);
3886 make_constraint_to (uses
->id
, gimple_call_chain (stmt
));
3887 rhsc
.var
= uses
->id
;
3890 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3893 /* May return arguments. */
3894 for (k
= 0; k
< gimple_call_num_args (stmt
); ++k
)
3896 tree arg
= gimple_call_arg (stmt
, k
);
3897 VEC(ce_s
, heap
) *argc
= NULL
;
3899 struct constraint_expr
*argp
;
3900 get_constraint_for_rhs (arg
, &argc
);
3901 FOR_EACH_VEC_ELT (ce_s
, argc
, i
, argp
)
3902 VEC_safe_push (ce_s
, heap
, *results
, argp
);
3903 VEC_free(ce_s
, heap
, argc
);
3906 /* May return addresses of globals. */
3907 rhsc
.var
= nonlocal_id
;
3909 rhsc
.type
= ADDRESSOF
;
3910 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3913 /* For non-IPA mode, generate constraints necessary for a call to a
3914 pure function in statement STMT. */
3917 handle_pure_call (gimple stmt
, VEC(ce_s
, heap
) **results
)
3919 struct constraint_expr rhsc
;
3921 varinfo_t uses
= NULL
;
3923 /* Memory reached from pointer arguments is call-used. */
3924 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
3926 tree arg
= gimple_call_arg (stmt
, i
);
3929 uses
= get_call_use_vi (stmt
);
3930 make_transitive_closure_constraints (uses
);
3932 make_constraint_to (uses
->id
, arg
);
3935 /* The static chain is used as well. */
3936 if (gimple_call_chain (stmt
))
3940 uses
= get_call_use_vi (stmt
);
3941 make_transitive_closure_constraints (uses
);
3943 make_constraint_to (uses
->id
, gimple_call_chain (stmt
));
3946 /* Pure functions may return call-used and nonlocal memory. */
3949 rhsc
.var
= uses
->id
;
3952 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3954 rhsc
.var
= nonlocal_id
;
3957 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3961 /* Return the varinfo for the callee of CALL. */
3964 get_fi_for_callee (gimple call
)
3966 tree decl
, fn
= gimple_call_fn (call
);
3968 if (fn
&& TREE_CODE (fn
) == OBJ_TYPE_REF
)
3969 fn
= OBJ_TYPE_REF_EXPR (fn
);
3971 /* If we can directly resolve the function being called, do so.
3972 Otherwise, it must be some sort of indirect expression that
3973 we should still be able to handle. */
3974 decl
= gimple_call_addr_fndecl (fn
);
3976 return get_vi_for_tree (decl
);
3978 /* If the function is anything other than a SSA name pointer we have no
3979 clue and should be getting ANYFN (well, ANYTHING for now). */
3980 if (!fn
|| TREE_CODE (fn
) != SSA_NAME
)
3981 return get_varinfo (anything_id
);
3983 if ((TREE_CODE (SSA_NAME_VAR (fn
)) == PARM_DECL
3984 || TREE_CODE (SSA_NAME_VAR (fn
)) == RESULT_DECL
)
3985 && SSA_NAME_IS_DEFAULT_DEF (fn
))
3986 fn
= SSA_NAME_VAR (fn
);
3988 return get_vi_for_tree (fn
);
3991 /* Create constraints for the builtin call T. Return true if the call
3992 was handled, otherwise false. */
3995 find_func_aliases_for_builtin_call (gimple t
)
3997 tree fndecl
= gimple_call_fndecl (t
);
3998 VEC(ce_s
, heap
) *lhsc
= NULL
;
3999 VEC(ce_s
, heap
) *rhsc
= NULL
;
4002 if (fndecl
!= NULL_TREE
4003 && DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
4004 /* ??? All builtins that are handled here need to be handled
4005 in the alias-oracle query functions explicitly! */
4006 switch (DECL_FUNCTION_CODE (fndecl
))
4008 /* All the following functions return a pointer to the same object
4009 as their first argument points to. The functions do not add
4010 to the ESCAPED solution. The functions make the first argument
4011 pointed to memory point to what the second argument pointed to
4012 memory points to. */
4013 case BUILT_IN_STRCPY
:
4014 case BUILT_IN_STRNCPY
:
4015 case BUILT_IN_BCOPY
:
4016 case BUILT_IN_MEMCPY
:
4017 case BUILT_IN_MEMMOVE
:
4018 case BUILT_IN_MEMPCPY
:
4019 case BUILT_IN_STPCPY
:
4020 case BUILT_IN_STPNCPY
:
4021 case BUILT_IN_STRCAT
:
4022 case BUILT_IN_STRNCAT
:
4023 case BUILT_IN_STRCPY_CHK
:
4024 case BUILT_IN_STRNCPY_CHK
:
4025 case BUILT_IN_MEMCPY_CHK
:
4026 case BUILT_IN_MEMMOVE_CHK
:
4027 case BUILT_IN_MEMPCPY_CHK
:
4028 case BUILT_IN_STPCPY_CHK
:
4029 case BUILT_IN_STRCAT_CHK
:
4030 case BUILT_IN_STRNCAT_CHK
:
4032 tree res
= gimple_call_lhs (t
);
4033 tree dest
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (fndecl
)
4034 == BUILT_IN_BCOPY
? 1 : 0));
4035 tree src
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (fndecl
)
4036 == BUILT_IN_BCOPY
? 0 : 1));
4037 if (res
!= NULL_TREE
)
4039 get_constraint_for (res
, &lhsc
);
4040 if (DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_MEMPCPY
4041 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPCPY
4042 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPNCPY
4043 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_MEMPCPY_CHK
4044 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPCPY_CHK
)
4045 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &rhsc
);
4047 get_constraint_for (dest
, &rhsc
);
4048 process_all_all_constraints (lhsc
, rhsc
);
4049 VEC_free (ce_s
, heap
, lhsc
);
4050 VEC_free (ce_s
, heap
, rhsc
);
4052 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4053 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4056 process_all_all_constraints (lhsc
, rhsc
);
4057 VEC_free (ce_s
, heap
, lhsc
);
4058 VEC_free (ce_s
, heap
, rhsc
);
4061 case BUILT_IN_MEMSET
:
4062 case BUILT_IN_MEMSET_CHK
:
4064 tree res
= gimple_call_lhs (t
);
4065 tree dest
= gimple_call_arg (t
, 0);
4068 struct constraint_expr ac
;
4069 if (res
!= NULL_TREE
)
4071 get_constraint_for (res
, &lhsc
);
4072 get_constraint_for (dest
, &rhsc
);
4073 process_all_all_constraints (lhsc
, rhsc
);
4074 VEC_free (ce_s
, heap
, lhsc
);
4075 VEC_free (ce_s
, heap
, rhsc
);
4077 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4079 if (flag_delete_null_pointer_checks
4080 && integer_zerop (gimple_call_arg (t
, 1)))
4082 ac
.type
= ADDRESSOF
;
4083 ac
.var
= nothing_id
;
4088 ac
.var
= integer_id
;
4091 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
4092 process_constraint (new_constraint (*lhsp
, ac
));
4093 VEC_free (ce_s
, heap
, lhsc
);
4096 case BUILT_IN_ASSUME_ALIGNED
:
4098 tree res
= gimple_call_lhs (t
);
4099 tree dest
= gimple_call_arg (t
, 0);
4100 if (res
!= NULL_TREE
)
4102 get_constraint_for (res
, &lhsc
);
4103 get_constraint_for (dest
, &rhsc
);
4104 process_all_all_constraints (lhsc
, rhsc
);
4105 VEC_free (ce_s
, heap
, lhsc
);
4106 VEC_free (ce_s
, heap
, rhsc
);
4110 /* All the following functions do not return pointers, do not
4111 modify the points-to sets of memory reachable from their
4112 arguments and do not add to the ESCAPED solution. */
4113 case BUILT_IN_SINCOS
:
4114 case BUILT_IN_SINCOSF
:
4115 case BUILT_IN_SINCOSL
:
4116 case BUILT_IN_FREXP
:
4117 case BUILT_IN_FREXPF
:
4118 case BUILT_IN_FREXPL
:
4119 case BUILT_IN_GAMMA_R
:
4120 case BUILT_IN_GAMMAF_R
:
4121 case BUILT_IN_GAMMAL_R
:
4122 case BUILT_IN_LGAMMA_R
:
4123 case BUILT_IN_LGAMMAF_R
:
4124 case BUILT_IN_LGAMMAL_R
:
4126 case BUILT_IN_MODFF
:
4127 case BUILT_IN_MODFL
:
4128 case BUILT_IN_REMQUO
:
4129 case BUILT_IN_REMQUOF
:
4130 case BUILT_IN_REMQUOL
:
4133 /* Trampolines are special - they set up passing the static
4135 case BUILT_IN_INIT_TRAMPOLINE
:
4137 tree tramp
= gimple_call_arg (t
, 0);
4138 tree nfunc
= gimple_call_arg (t
, 1);
4139 tree frame
= gimple_call_arg (t
, 2);
4141 struct constraint_expr lhs
, *rhsp
;
4144 varinfo_t nfi
= NULL
;
4145 gcc_assert (TREE_CODE (nfunc
) == ADDR_EXPR
);
4146 nfi
= lookup_vi_for_tree (TREE_OPERAND (nfunc
, 0));
4149 lhs
= get_function_part_constraint (nfi
, fi_static_chain
);
4150 get_constraint_for (frame
, &rhsc
);
4151 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4152 process_constraint (new_constraint (lhs
, *rhsp
));
4153 VEC_free (ce_s
, heap
, rhsc
);
4155 /* Make the frame point to the function for
4156 the trampoline adjustment call. */
4157 get_constraint_for (tramp
, &lhsc
);
4159 get_constraint_for (nfunc
, &rhsc
);
4160 process_all_all_constraints (lhsc
, rhsc
);
4161 VEC_free (ce_s
, heap
, rhsc
);
4162 VEC_free (ce_s
, heap
, lhsc
);
4167 /* Else fallthru to generic handling which will let
4168 the frame escape. */
4171 case BUILT_IN_ADJUST_TRAMPOLINE
:
4173 tree tramp
= gimple_call_arg (t
, 0);
4174 tree res
= gimple_call_lhs (t
);
4175 if (in_ipa_mode
&& res
)
4177 get_constraint_for (res
, &lhsc
);
4178 get_constraint_for (tramp
, &rhsc
);
4180 process_all_all_constraints (lhsc
, rhsc
);
4181 VEC_free (ce_s
, heap
, rhsc
);
4182 VEC_free (ce_s
, heap
, lhsc
);
4186 /* Variadic argument handling needs to be handled in IPA
4188 case BUILT_IN_VA_START
:
4190 tree valist
= gimple_call_arg (t
, 0);
4191 struct constraint_expr rhs
, *lhsp
;
4193 get_constraint_for (valist
, &lhsc
);
4195 /* The va_list gets access to pointers in variadic
4196 arguments. Which we know in the case of IPA analysis
4197 and otherwise are just all nonlocal variables. */
4200 fi
= lookup_vi_for_tree (cfun
->decl
);
4201 rhs
= get_function_part_constraint (fi
, ~0);
4202 rhs
.type
= ADDRESSOF
;
4206 rhs
.var
= nonlocal_id
;
4207 rhs
.type
= ADDRESSOF
;
4210 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
4211 process_constraint (new_constraint (*lhsp
, rhs
));
4212 VEC_free (ce_s
, heap
, lhsc
);
4213 /* va_list is clobbered. */
4214 make_constraint_to (get_call_clobber_vi (t
)->id
, valist
);
4217 /* va_end doesn't have any effect that matters. */
4218 case BUILT_IN_VA_END
:
4220 /* Alternate return. Simply give up for now. */
4221 case BUILT_IN_RETURN
:
4225 || !(fi
= get_vi_for_tree (cfun
->decl
)))
4226 make_constraint_from (get_varinfo (escaped_id
), anything_id
);
4227 else if (in_ipa_mode
4230 struct constraint_expr lhs
, rhs
;
4231 lhs
= get_function_part_constraint (fi
, fi_result
);
4232 rhs
.var
= anything_id
;
4235 process_constraint (new_constraint (lhs
, rhs
));
4239 /* printf-style functions may have hooks to set pointers to
4240 point to somewhere into the generated string. Leave them
4241 for a later excercise... */
4243 /* Fallthru to general call handling. */;
4249 /* Create constraints for the call T. */
4252 find_func_aliases_for_call (gimple t
)
4254 tree fndecl
= gimple_call_fndecl (t
);
4255 VEC(ce_s
, heap
) *lhsc
= NULL
;
4256 VEC(ce_s
, heap
) *rhsc
= NULL
;
4259 if (fndecl
!= NULL_TREE
4260 && DECL_BUILT_IN (fndecl
)
4261 && find_func_aliases_for_builtin_call (t
))
4264 fi
= get_fi_for_callee (t
);
4266 || (fndecl
&& !fi
->is_fn_info
))
4268 VEC(ce_s
, heap
) *rhsc
= NULL
;
4269 int flags
= gimple_call_flags (t
);
4271 /* Const functions can return their arguments and addresses
4272 of global memory but not of escaped memory. */
4273 if (flags
& (ECF_CONST
|ECF_NOVOPS
))
4275 if (gimple_call_lhs (t
))
4276 handle_const_call (t
, &rhsc
);
4278 /* Pure functions can return addresses in and of memory
4279 reachable from their arguments, but they are not an escape
4280 point for reachable memory of their arguments. */
4281 else if (flags
& (ECF_PURE
|ECF_LOOPING_CONST_OR_PURE
))
4282 handle_pure_call (t
, &rhsc
);
4284 handle_rhs_call (t
, &rhsc
);
4285 if (gimple_call_lhs (t
))
4286 handle_lhs_call (t
, gimple_call_lhs (t
), flags
, rhsc
, fndecl
);
4287 VEC_free (ce_s
, heap
, rhsc
);
4294 /* Assign all the passed arguments to the appropriate incoming
4295 parameters of the function. */
4296 for (j
= 0; j
< gimple_call_num_args (t
); j
++)
4298 struct constraint_expr lhs
;
4299 struct constraint_expr
*rhsp
;
4300 tree arg
= gimple_call_arg (t
, j
);
4302 get_constraint_for_rhs (arg
, &rhsc
);
4303 lhs
= get_function_part_constraint (fi
, fi_parm_base
+ j
);
4304 while (VEC_length (ce_s
, rhsc
) != 0)
4306 rhsp
= VEC_last (ce_s
, rhsc
);
4307 process_constraint (new_constraint (lhs
, *rhsp
));
4308 VEC_pop (ce_s
, rhsc
);
4312 /* If we are returning a value, assign it to the result. */
4313 lhsop
= gimple_call_lhs (t
);
4316 struct constraint_expr rhs
;
4317 struct constraint_expr
*lhsp
;
4319 get_constraint_for (lhsop
, &lhsc
);
4320 rhs
= get_function_part_constraint (fi
, fi_result
);
4322 && DECL_RESULT (fndecl
)
4323 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
4325 VEC(ce_s
, heap
) *tem
= NULL
;
4326 VEC_safe_push (ce_s
, heap
, tem
, &rhs
);
4328 rhs
= *VEC_index (ce_s
, tem
, 0);
4329 VEC_free(ce_s
, heap
, tem
);
4331 FOR_EACH_VEC_ELT (ce_s
, lhsc
, j
, lhsp
)
4332 process_constraint (new_constraint (*lhsp
, rhs
));
4335 /* If we pass the result decl by reference, honor that. */
4338 && DECL_RESULT (fndecl
)
4339 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
4341 struct constraint_expr lhs
;
4342 struct constraint_expr
*rhsp
;
4344 get_constraint_for_address_of (lhsop
, &rhsc
);
4345 lhs
= get_function_part_constraint (fi
, fi_result
);
4346 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, rhsp
)
4347 process_constraint (new_constraint (lhs
, *rhsp
));
4348 VEC_free (ce_s
, heap
, rhsc
);
4351 /* If we use a static chain, pass it along. */
4352 if (gimple_call_chain (t
))
4354 struct constraint_expr lhs
;
4355 struct constraint_expr
*rhsp
;
4357 get_constraint_for (gimple_call_chain (t
), &rhsc
);
4358 lhs
= get_function_part_constraint (fi
, fi_static_chain
);
4359 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, rhsp
)
4360 process_constraint (new_constraint (lhs
, *rhsp
));
4365 /* Walk statement T setting up aliasing constraints according to the
4366 references found in T. This function is the main part of the
4367 constraint builder. AI points to auxiliary alias information used
4368 when building alias sets and computing alias grouping heuristics. */
4371 find_func_aliases (gimple origt
)
4374 VEC(ce_s
, heap
) *lhsc
= NULL
;
4375 VEC(ce_s
, heap
) *rhsc
= NULL
;
4376 struct constraint_expr
*c
;
4379 /* Now build constraints expressions. */
4380 if (gimple_code (t
) == GIMPLE_PHI
)
4385 /* For a phi node, assign all the arguments to
4387 get_constraint_for (gimple_phi_result (t
), &lhsc
);
4388 for (i
= 0; i
< gimple_phi_num_args (t
); i
++)
4390 tree strippedrhs
= PHI_ARG_DEF (t
, i
);
4392 STRIP_NOPS (strippedrhs
);
4393 get_constraint_for_rhs (gimple_phi_arg_def (t
, i
), &rhsc
);
4395 FOR_EACH_VEC_ELT (ce_s
, lhsc
, j
, c
)
4397 struct constraint_expr
*c2
;
4398 while (VEC_length (ce_s
, rhsc
) > 0)
4400 c2
= VEC_last (ce_s
, rhsc
);
4401 process_constraint (new_constraint (*c
, *c2
));
4402 VEC_pop (ce_s
, rhsc
);
4407 /* In IPA mode, we need to generate constraints to pass call
4408 arguments through their calls. There are two cases,
4409 either a GIMPLE_CALL returning a value, or just a plain
4410 GIMPLE_CALL when we are not.
4412 In non-ipa mode, we need to generate constraints for each
4413 pointer passed by address. */
4414 else if (is_gimple_call (t
))
4415 find_func_aliases_for_call (t
);
4417 /* Otherwise, just a regular assignment statement. Only care about
4418 operations with pointer result, others are dealt with as escape
4419 points if they have pointer operands. */
4420 else if (is_gimple_assign (t
))
4422 /* Otherwise, just a regular assignment statement. */
4423 tree lhsop
= gimple_assign_lhs (t
);
4424 tree rhsop
= (gimple_num_ops (t
) == 2) ? gimple_assign_rhs1 (t
) : NULL
;
4426 if (rhsop
&& AGGREGATE_TYPE_P (TREE_TYPE (lhsop
)))
4427 do_structure_copy (lhsop
, rhsop
);
4430 enum tree_code code
= gimple_assign_rhs_code (t
);
4432 get_constraint_for (lhsop
, &lhsc
);
4434 if (code
== POINTER_PLUS_EXPR
)
4435 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t
),
4436 gimple_assign_rhs2 (t
), &rhsc
);
4437 else if (code
== BIT_AND_EXPR
4438 && TREE_CODE (gimple_assign_rhs2 (t
)) == INTEGER_CST
)
4440 /* Aligning a pointer via a BIT_AND_EXPR is offsetting
4441 the pointer. Handle it by offsetting it by UNKNOWN. */
4442 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t
),
4445 else if ((CONVERT_EXPR_CODE_P (code
)
4446 && !(POINTER_TYPE_P (gimple_expr_type (t
))
4447 && !POINTER_TYPE_P (TREE_TYPE (rhsop
))))
4448 || gimple_assign_single_p (t
))
4449 get_constraint_for_rhs (rhsop
, &rhsc
);
4450 else if (truth_value_p (code
))
4451 /* Truth value results are not pointer (parts). Or at least
4452 very very unreasonable obfuscation of a part. */
4456 /* All other operations are merges. */
4457 VEC (ce_s
, heap
) *tmp
= NULL
;
4458 struct constraint_expr
*rhsp
;
4460 get_constraint_for_rhs (gimple_assign_rhs1 (t
), &rhsc
);
4461 for (i
= 2; i
< gimple_num_ops (t
); ++i
)
4463 get_constraint_for_rhs (gimple_op (t
, i
), &tmp
);
4464 FOR_EACH_VEC_ELT (ce_s
, tmp
, j
, rhsp
)
4465 VEC_safe_push (ce_s
, heap
, rhsc
, rhsp
);
4466 VEC_truncate (ce_s
, tmp
, 0);
4468 VEC_free (ce_s
, heap
, tmp
);
4470 process_all_all_constraints (lhsc
, rhsc
);
4472 /* If there is a store to a global variable the rhs escapes. */
4473 if ((lhsop
= get_base_address (lhsop
)) != NULL_TREE
4475 && is_global_var (lhsop
)
4477 || DECL_EXTERNAL (lhsop
) || TREE_PUBLIC (lhsop
)))
4478 make_escape_constraint (rhsop
);
4479 /* If this is a conversion of a non-restrict pointer to a
4480 restrict pointer track it with a new heapvar. */
4481 else if (gimple_assign_cast_p (t
)
4482 && POINTER_TYPE_P (TREE_TYPE (rhsop
))
4483 && POINTER_TYPE_P (TREE_TYPE (lhsop
))
4484 && !TYPE_RESTRICT (TREE_TYPE (rhsop
))
4485 && TYPE_RESTRICT (TREE_TYPE (lhsop
)))
4486 make_constraint_from_restrict (get_vi_for_tree (lhsop
),
4489 /* Handle escapes through return. */
4490 else if (gimple_code (t
) == GIMPLE_RETURN
4491 && gimple_return_retval (t
) != NULL_TREE
)
4495 || !(fi
= get_vi_for_tree (cfun
->decl
)))
4496 make_escape_constraint (gimple_return_retval (t
));
4497 else if (in_ipa_mode
4500 struct constraint_expr lhs
;
4501 struct constraint_expr
*rhsp
;
4504 lhs
= get_function_part_constraint (fi
, fi_result
);
4505 get_constraint_for_rhs (gimple_return_retval (t
), &rhsc
);
4506 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4507 process_constraint (new_constraint (lhs
, *rhsp
));
4510 /* Handle asms conservatively by adding escape constraints to everything. */
4511 else if (gimple_code (t
) == GIMPLE_ASM
)
4513 unsigned i
, noutputs
;
4514 const char **oconstraints
;
4515 const char *constraint
;
4516 bool allows_mem
, allows_reg
, is_inout
;
4518 noutputs
= gimple_asm_noutputs (t
);
4519 oconstraints
= XALLOCAVEC (const char *, noutputs
);
4521 for (i
= 0; i
< noutputs
; ++i
)
4523 tree link
= gimple_asm_output_op (t
, i
);
4524 tree op
= TREE_VALUE (link
);
4526 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
4527 oconstraints
[i
] = constraint
;
4528 parse_output_constraint (&constraint
, i
, 0, 0, &allows_mem
,
4529 &allows_reg
, &is_inout
);
4531 /* A memory constraint makes the address of the operand escape. */
4532 if (!allows_reg
&& allows_mem
)
4533 make_escape_constraint (build_fold_addr_expr (op
));
4535 /* The asm may read global memory, so outputs may point to
4536 any global memory. */
4539 VEC(ce_s
, heap
) *lhsc
= NULL
;
4540 struct constraint_expr rhsc
, *lhsp
;
4542 get_constraint_for (op
, &lhsc
);
4543 rhsc
.var
= nonlocal_id
;
4546 FOR_EACH_VEC_ELT (ce_s
, lhsc
, j
, lhsp
)
4547 process_constraint (new_constraint (*lhsp
, rhsc
));
4548 VEC_free (ce_s
, heap
, lhsc
);
4551 for (i
= 0; i
< gimple_asm_ninputs (t
); ++i
)
4553 tree link
= gimple_asm_input_op (t
, i
);
4554 tree op
= TREE_VALUE (link
);
4556 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
4558 parse_input_constraint (&constraint
, 0, 0, noutputs
, 0, oconstraints
,
4559 &allows_mem
, &allows_reg
);
4561 /* A memory constraint makes the address of the operand escape. */
4562 if (!allows_reg
&& allows_mem
)
4563 make_escape_constraint (build_fold_addr_expr (op
));
4564 /* Strictly we'd only need the constraint to ESCAPED if
4565 the asm clobbers memory, otherwise using something
4566 along the lines of per-call clobbers/uses would be enough. */
4568 make_escape_constraint (op
);
4572 VEC_free (ce_s
, heap
, rhsc
);
4573 VEC_free (ce_s
, heap
, lhsc
);
4577 /* Create a constraint adding to the clobber set of FI the memory
4578 pointed to by PTR. */
4581 process_ipa_clobber (varinfo_t fi
, tree ptr
)
4583 VEC(ce_s
, heap
) *ptrc
= NULL
;
4584 struct constraint_expr
*c
, lhs
;
4586 get_constraint_for_rhs (ptr
, &ptrc
);
4587 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4588 FOR_EACH_VEC_ELT (ce_s
, ptrc
, i
, c
)
4589 process_constraint (new_constraint (lhs
, *c
));
4590 VEC_free (ce_s
, heap
, ptrc
);
4593 /* Walk statement T setting up clobber and use constraints according to the
4594 references found in T. This function is a main part of the
4595 IPA constraint builder. */
4598 find_func_clobbers (gimple origt
)
4601 VEC(ce_s
, heap
) *lhsc
= NULL
;
4602 VEC(ce_s
, heap
) *rhsc
= NULL
;
4605 /* Add constraints for clobbered/used in IPA mode.
4606 We are not interested in what automatic variables are clobbered
4607 or used as we only use the information in the caller to which
4608 they do not escape. */
4609 gcc_assert (in_ipa_mode
);
4611 /* If the stmt refers to memory in any way it better had a VUSE. */
4612 if (gimple_vuse (t
) == NULL_TREE
)
4615 /* We'd better have function information for the current function. */
4616 fi
= lookup_vi_for_tree (cfun
->decl
);
4617 gcc_assert (fi
!= NULL
);
4619 /* Account for stores in assignments and calls. */
4620 if (gimple_vdef (t
) != NULL_TREE
4621 && gimple_has_lhs (t
))
4623 tree lhs
= gimple_get_lhs (t
);
4625 while (handled_component_p (tem
))
4626 tem
= TREE_OPERAND (tem
, 0);
4628 && !auto_var_in_fn_p (tem
, cfun
->decl
))
4629 || INDIRECT_REF_P (tem
)
4630 || (TREE_CODE (tem
) == MEM_REF
4631 && !(TREE_CODE (TREE_OPERAND (tem
, 0)) == ADDR_EXPR
4633 (TREE_OPERAND (TREE_OPERAND (tem
, 0), 0), cfun
->decl
))))
4635 struct constraint_expr lhsc
, *rhsp
;
4637 lhsc
= get_function_part_constraint (fi
, fi_clobbers
);
4638 get_constraint_for_address_of (lhs
, &rhsc
);
4639 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4640 process_constraint (new_constraint (lhsc
, *rhsp
));
4641 VEC_free (ce_s
, heap
, rhsc
);
4645 /* Account for uses in assigments and returns. */
4646 if (gimple_assign_single_p (t
)
4647 || (gimple_code (t
) == GIMPLE_RETURN
4648 && gimple_return_retval (t
) != NULL_TREE
))
4650 tree rhs
= (gimple_assign_single_p (t
)
4651 ? gimple_assign_rhs1 (t
) : gimple_return_retval (t
));
4653 while (handled_component_p (tem
))
4654 tem
= TREE_OPERAND (tem
, 0);
4656 && !auto_var_in_fn_p (tem
, cfun
->decl
))
4657 || INDIRECT_REF_P (tem
)
4658 || (TREE_CODE (tem
) == MEM_REF
4659 && !(TREE_CODE (TREE_OPERAND (tem
, 0)) == ADDR_EXPR
4661 (TREE_OPERAND (TREE_OPERAND (tem
, 0), 0), cfun
->decl
))))
4663 struct constraint_expr lhs
, *rhsp
;
4665 lhs
= get_function_part_constraint (fi
, fi_uses
);
4666 get_constraint_for_address_of (rhs
, &rhsc
);
4667 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4668 process_constraint (new_constraint (lhs
, *rhsp
));
4669 VEC_free (ce_s
, heap
, rhsc
);
4673 if (is_gimple_call (t
))
4675 varinfo_t cfi
= NULL
;
4676 tree decl
= gimple_call_fndecl (t
);
4677 struct constraint_expr lhs
, rhs
;
4680 /* For builtins we do not have separate function info. For those
4681 we do not generate escapes for we have to generate clobbers/uses. */
4683 && DECL_BUILT_IN_CLASS (decl
) == BUILT_IN_NORMAL
)
4684 switch (DECL_FUNCTION_CODE (decl
))
4686 /* The following functions use and clobber memory pointed to
4687 by their arguments. */
4688 case BUILT_IN_STRCPY
:
4689 case BUILT_IN_STRNCPY
:
4690 case BUILT_IN_BCOPY
:
4691 case BUILT_IN_MEMCPY
:
4692 case BUILT_IN_MEMMOVE
:
4693 case BUILT_IN_MEMPCPY
:
4694 case BUILT_IN_STPCPY
:
4695 case BUILT_IN_STPNCPY
:
4696 case BUILT_IN_STRCAT
:
4697 case BUILT_IN_STRNCAT
:
4698 case BUILT_IN_STRCPY_CHK
:
4699 case BUILT_IN_STRNCPY_CHK
:
4700 case BUILT_IN_MEMCPY_CHK
:
4701 case BUILT_IN_MEMMOVE_CHK
:
4702 case BUILT_IN_MEMPCPY_CHK
:
4703 case BUILT_IN_STPCPY_CHK
:
4704 case BUILT_IN_STRCAT_CHK
:
4705 case BUILT_IN_STRNCAT_CHK
:
4707 tree dest
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (decl
)
4708 == BUILT_IN_BCOPY
? 1 : 0));
4709 tree src
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (decl
)
4710 == BUILT_IN_BCOPY
? 0 : 1));
4712 struct constraint_expr
*rhsp
, *lhsp
;
4713 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4714 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4715 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
4716 process_constraint (new_constraint (lhs
, *lhsp
));
4717 VEC_free (ce_s
, heap
, lhsc
);
4718 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4719 lhs
= get_function_part_constraint (fi
, fi_uses
);
4720 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4721 process_constraint (new_constraint (lhs
, *rhsp
));
4722 VEC_free (ce_s
, heap
, rhsc
);
4725 /* The following function clobbers memory pointed to by
4727 case BUILT_IN_MEMSET
:
4728 case BUILT_IN_MEMSET_CHK
:
4730 tree dest
= gimple_call_arg (t
, 0);
4733 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4734 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4735 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
4736 process_constraint (new_constraint (lhs
, *lhsp
));
4737 VEC_free (ce_s
, heap
, lhsc
);
4740 /* The following functions clobber their second and third
4742 case BUILT_IN_SINCOS
:
4743 case BUILT_IN_SINCOSF
:
4744 case BUILT_IN_SINCOSL
:
4746 process_ipa_clobber (fi
, gimple_call_arg (t
, 1));
4747 process_ipa_clobber (fi
, gimple_call_arg (t
, 2));
4750 /* The following functions clobber their second argument. */
4751 case BUILT_IN_FREXP
:
4752 case BUILT_IN_FREXPF
:
4753 case BUILT_IN_FREXPL
:
4754 case BUILT_IN_LGAMMA_R
:
4755 case BUILT_IN_LGAMMAF_R
:
4756 case BUILT_IN_LGAMMAL_R
:
4757 case BUILT_IN_GAMMA_R
:
4758 case BUILT_IN_GAMMAF_R
:
4759 case BUILT_IN_GAMMAL_R
:
4761 case BUILT_IN_MODFF
:
4762 case BUILT_IN_MODFL
:
4764 process_ipa_clobber (fi
, gimple_call_arg (t
, 1));
4767 /* The following functions clobber their third argument. */
4768 case BUILT_IN_REMQUO
:
4769 case BUILT_IN_REMQUOF
:
4770 case BUILT_IN_REMQUOL
:
4772 process_ipa_clobber (fi
, gimple_call_arg (t
, 2));
4775 /* The following functions neither read nor clobber memory. */
4776 case BUILT_IN_ASSUME_ALIGNED
:
4779 /* Trampolines are of no interest to us. */
4780 case BUILT_IN_INIT_TRAMPOLINE
:
4781 case BUILT_IN_ADJUST_TRAMPOLINE
:
4783 case BUILT_IN_VA_START
:
4784 case BUILT_IN_VA_END
:
4786 /* printf-style functions may have hooks to set pointers to
4787 point to somewhere into the generated string. Leave them
4788 for a later excercise... */
4790 /* Fallthru to general call handling. */;
4793 /* Parameters passed by value are used. */
4794 lhs
= get_function_part_constraint (fi
, fi_uses
);
4795 for (i
= 0; i
< gimple_call_num_args (t
); i
++)
4797 struct constraint_expr
*rhsp
;
4798 tree arg
= gimple_call_arg (t
, i
);
4800 if (TREE_CODE (arg
) == SSA_NAME
4801 || is_gimple_min_invariant (arg
))
4804 get_constraint_for_address_of (arg
, &rhsc
);
4805 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, rhsp
)
4806 process_constraint (new_constraint (lhs
, *rhsp
));
4807 VEC_free (ce_s
, heap
, rhsc
);
4810 /* Build constraints for propagating clobbers/uses along the
4812 cfi
= get_fi_for_callee (t
);
4813 if (cfi
->id
== anything_id
)
4815 if (gimple_vdef (t
))
4816 make_constraint_from (first_vi_for_offset (fi
, fi_clobbers
),
4818 make_constraint_from (first_vi_for_offset (fi
, fi_uses
),
4823 /* For callees without function info (that's external functions),
4824 ESCAPED is clobbered and used. */
4825 if (gimple_call_fndecl (t
)
4826 && !cfi
->is_fn_info
)
4830 if (gimple_vdef (t
))
4831 make_copy_constraint (first_vi_for_offset (fi
, fi_clobbers
),
4833 make_copy_constraint (first_vi_for_offset (fi
, fi_uses
), escaped_id
);
4835 /* Also honor the call statement use/clobber info. */
4836 if ((vi
= lookup_call_clobber_vi (t
)) != NULL
)
4837 make_copy_constraint (first_vi_for_offset (fi
, fi_clobbers
),
4839 if ((vi
= lookup_call_use_vi (t
)) != NULL
)
4840 make_copy_constraint (first_vi_for_offset (fi
, fi_uses
),
4845 /* Otherwise the caller clobbers and uses what the callee does.
4846 ??? This should use a new complex constraint that filters
4847 local variables of the callee. */
4848 if (gimple_vdef (t
))
4850 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4851 rhs
= get_function_part_constraint (cfi
, fi_clobbers
);
4852 process_constraint (new_constraint (lhs
, rhs
));
4854 lhs
= get_function_part_constraint (fi
, fi_uses
);
4855 rhs
= get_function_part_constraint (cfi
, fi_uses
);
4856 process_constraint (new_constraint (lhs
, rhs
));
4858 else if (gimple_code (t
) == GIMPLE_ASM
)
4860 /* ??? Ick. We can do better. */
4861 if (gimple_vdef (t
))
4862 make_constraint_from (first_vi_for_offset (fi
, fi_clobbers
),
4864 make_constraint_from (first_vi_for_offset (fi
, fi_uses
),
4868 VEC_free (ce_s
, heap
, rhsc
);
4872 /* Find the first varinfo in the same variable as START that overlaps with
4873 OFFSET. Return NULL if we can't find one. */
4876 first_vi_for_offset (varinfo_t start
, unsigned HOST_WIDE_INT offset
)
4878 /* If the offset is outside of the variable, bail out. */
4879 if (offset
>= start
->fullsize
)
4882 /* If we cannot reach offset from start, lookup the first field
4883 and start from there. */
4884 if (start
->offset
> offset
)
4885 start
= lookup_vi_for_tree (start
->decl
);
4889 /* We may not find a variable in the field list with the actual
4890 offset when when we have glommed a structure to a variable.
4891 In that case, however, offset should still be within the size
4893 if (offset
>= start
->offset
4894 && (offset
- start
->offset
) < start
->size
)
4903 /* Find the first varinfo in the same variable as START that overlaps with
4904 OFFSET. If there is no such varinfo the varinfo directly preceding
4905 OFFSET is returned. */
4908 first_or_preceding_vi_for_offset (varinfo_t start
,
4909 unsigned HOST_WIDE_INT offset
)
4911 /* If we cannot reach offset from start, lookup the first field
4912 and start from there. */
4913 if (start
->offset
> offset
)
4914 start
= lookup_vi_for_tree (start
->decl
);
4916 /* We may not find a variable in the field list with the actual
4917 offset when when we have glommed a structure to a variable.
4918 In that case, however, offset should still be within the size
4920 If we got beyond the offset we look for return the field
4921 directly preceding offset which may be the last field. */
4923 && offset
>= start
->offset
4924 && !((offset
- start
->offset
) < start
->size
))
4925 start
= start
->next
;
4931 /* This structure is used during pushing fields onto the fieldstack
4932 to track the offset of the field, since bitpos_of_field gives it
4933 relative to its immediate containing type, and we want it relative
4934 to the ultimate containing object. */
4938 /* Offset from the base of the base containing object to this field. */
4939 HOST_WIDE_INT offset
;
4941 /* Size, in bits, of the field. */
4942 unsigned HOST_WIDE_INT size
;
4944 unsigned has_unknown_size
: 1;
4946 unsigned must_have_pointers
: 1;
4948 unsigned may_have_pointers
: 1;
4950 unsigned only_restrict_pointers
: 1;
4952 typedef struct fieldoff fieldoff_s
;
4954 DEF_VEC_O(fieldoff_s
);
4955 DEF_VEC_ALLOC_O(fieldoff_s
,heap
);
4957 /* qsort comparison function for two fieldoff's PA and PB */
4960 fieldoff_compare (const void *pa
, const void *pb
)
4962 const fieldoff_s
*foa
= (const fieldoff_s
*)pa
;
4963 const fieldoff_s
*fob
= (const fieldoff_s
*)pb
;
4964 unsigned HOST_WIDE_INT foasize
, fobsize
;
4966 if (foa
->offset
< fob
->offset
)
4968 else if (foa
->offset
> fob
->offset
)
4971 foasize
= foa
->size
;
4972 fobsize
= fob
->size
;
4973 if (foasize
< fobsize
)
4975 else if (foasize
> fobsize
)
4980 /* Sort a fieldstack according to the field offset and sizes. */
4982 sort_fieldstack (VEC(fieldoff_s
,heap
) *fieldstack
)
4984 VEC_qsort (fieldoff_s
, fieldstack
, fieldoff_compare
);
4987 /* Return true if V is a tree that we can have subvars for.
4988 Normally, this is any aggregate type. Also complex
4989 types which are not gimple registers can have subvars. */
4992 var_can_have_subvars (const_tree v
)
4994 /* Volatile variables should never have subvars. */
4995 if (TREE_THIS_VOLATILE (v
))
4998 /* Non decls or memory tags can never have subvars. */
5002 /* Aggregates without overlapping fields can have subvars. */
5003 if (TREE_CODE (TREE_TYPE (v
)) == RECORD_TYPE
)
5009 /* Return true if T is a type that does contain pointers. */
5012 type_must_have_pointers (tree type
)
5014 if (POINTER_TYPE_P (type
))
5017 if (TREE_CODE (type
) == ARRAY_TYPE
)
5018 return type_must_have_pointers (TREE_TYPE (type
));
5020 /* A function or method can have pointers as arguments, so track
5021 those separately. */
5022 if (TREE_CODE (type
) == FUNCTION_TYPE
5023 || TREE_CODE (type
) == METHOD_TYPE
)
5030 field_must_have_pointers (tree t
)
5032 return type_must_have_pointers (TREE_TYPE (t
));
5035 /* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
5036 the fields of TYPE onto fieldstack, recording their offsets along
5039 OFFSET is used to keep track of the offset in this entire
5040 structure, rather than just the immediately containing structure.
5041 Returns false if the caller is supposed to handle the field we
5045 push_fields_onto_fieldstack (tree type
, VEC(fieldoff_s
,heap
) **fieldstack
,
5046 HOST_WIDE_INT offset
)
5049 bool empty_p
= true;
5051 if (TREE_CODE (type
) != RECORD_TYPE
)
5054 /* If the vector of fields is growing too big, bail out early.
5055 Callers check for VEC_length <= MAX_FIELDS_FOR_FIELD_SENSITIVE, make
5057 if (VEC_length (fieldoff_s
, *fieldstack
) > MAX_FIELDS_FOR_FIELD_SENSITIVE
)
5060 for (field
= TYPE_FIELDS (type
); field
; field
= DECL_CHAIN (field
))
5061 if (TREE_CODE (field
) == FIELD_DECL
)
5064 HOST_WIDE_INT foff
= bitpos_of_field (field
);
5066 if (!var_can_have_subvars (field
)
5067 || TREE_CODE (TREE_TYPE (field
)) == QUAL_UNION_TYPE
5068 || TREE_CODE (TREE_TYPE (field
)) == UNION_TYPE
)
5070 else if (!push_fields_onto_fieldstack
5071 (TREE_TYPE (field
), fieldstack
, offset
+ foff
)
5072 && (DECL_SIZE (field
)
5073 && !integer_zerop (DECL_SIZE (field
))))
5074 /* Empty structures may have actual size, like in C++. So
5075 see if we didn't push any subfields and the size is
5076 nonzero, push the field onto the stack. */
5081 fieldoff_s
*pair
= NULL
;
5082 bool has_unknown_size
= false;
5083 bool must_have_pointers_p
;
5085 if (!VEC_empty (fieldoff_s
, *fieldstack
))
5086 pair
= VEC_last (fieldoff_s
, *fieldstack
);
5088 /* If there isn't anything at offset zero, create sth. */
5090 && offset
+ foff
!= 0)
5092 pair
= VEC_safe_push (fieldoff_s
, heap
, *fieldstack
, NULL
);
5094 pair
->size
= offset
+ foff
;
5095 pair
->has_unknown_size
= false;
5096 pair
->must_have_pointers
= false;
5097 pair
->may_have_pointers
= false;
5098 pair
->only_restrict_pointers
= false;
5101 if (!DECL_SIZE (field
)
5102 || !host_integerp (DECL_SIZE (field
), 1))
5103 has_unknown_size
= true;
5105 /* If adjacent fields do not contain pointers merge them. */
5106 must_have_pointers_p
= field_must_have_pointers (field
);
5108 && !has_unknown_size
5109 && !must_have_pointers_p
5110 && !pair
->must_have_pointers
5111 && !pair
->has_unknown_size
5112 && pair
->offset
+ (HOST_WIDE_INT
)pair
->size
== offset
+ foff
)
5114 pair
->size
+= TREE_INT_CST_LOW (DECL_SIZE (field
));
5118 pair
= VEC_safe_push (fieldoff_s
, heap
, *fieldstack
, NULL
);
5119 pair
->offset
= offset
+ foff
;
5120 pair
->has_unknown_size
= has_unknown_size
;
5121 if (!has_unknown_size
)
5122 pair
->size
= TREE_INT_CST_LOW (DECL_SIZE (field
));
5125 pair
->must_have_pointers
= must_have_pointers_p
;
5126 pair
->may_have_pointers
= true;
5127 pair
->only_restrict_pointers
5128 = (!has_unknown_size
5129 && POINTER_TYPE_P (TREE_TYPE (field
))
5130 && TYPE_RESTRICT (TREE_TYPE (field
)));
5140 /* Count the number of arguments DECL has, and set IS_VARARGS to true
5141 if it is a varargs function. */
5144 count_num_arguments (tree decl
, bool *is_varargs
)
5146 unsigned int num
= 0;
5149 /* Capture named arguments for K&R functions. They do not
5150 have a prototype and thus no TYPE_ARG_TYPES. */
5151 for (t
= DECL_ARGUMENTS (decl
); t
; t
= DECL_CHAIN (t
))
5154 /* Check if the function has variadic arguments. */
5155 for (t
= TYPE_ARG_TYPES (TREE_TYPE (decl
)); t
; t
= TREE_CHAIN (t
))
5156 if (TREE_VALUE (t
) == void_type_node
)
5164 /* Creation function node for DECL, using NAME, and return the index
5165 of the variable we've created for the function. */
5168 create_function_info_for (tree decl
, const char *name
)
5170 struct function
*fn
= DECL_STRUCT_FUNCTION (decl
);
5171 varinfo_t vi
, prev_vi
;
5174 bool is_varargs
= false;
5175 unsigned int num_args
= count_num_arguments (decl
, &is_varargs
);
5177 /* Create the variable info. */
5179 vi
= new_var_info (decl
, name
);
5182 vi
->fullsize
= fi_parm_base
+ num_args
;
5184 vi
->may_have_pointers
= false;
5187 insert_vi_for_tree (vi
->decl
, vi
);
5191 /* Create a variable for things the function clobbers and one for
5192 things the function uses. */
5194 varinfo_t clobbervi
, usevi
;
5195 const char *newname
;
5198 asprintf (&tempname
, "%s.clobber", name
);
5199 newname
= ggc_strdup (tempname
);
5202 clobbervi
= new_var_info (NULL
, newname
);
5203 clobbervi
->offset
= fi_clobbers
;
5204 clobbervi
->size
= 1;
5205 clobbervi
->fullsize
= vi
->fullsize
;
5206 clobbervi
->is_full_var
= true;
5207 clobbervi
->is_global_var
= false;
5208 gcc_assert (prev_vi
->offset
< clobbervi
->offset
);
5209 prev_vi
->next
= clobbervi
;
5210 prev_vi
= clobbervi
;
5212 asprintf (&tempname
, "%s.use", name
);
5213 newname
= ggc_strdup (tempname
);
5216 usevi
= new_var_info (NULL
, newname
);
5217 usevi
->offset
= fi_uses
;
5219 usevi
->fullsize
= vi
->fullsize
;
5220 usevi
->is_full_var
= true;
5221 usevi
->is_global_var
= false;
5222 gcc_assert (prev_vi
->offset
< usevi
->offset
);
5223 prev_vi
->next
= usevi
;
5227 /* And one for the static chain. */
5228 if (fn
->static_chain_decl
!= NULL_TREE
)
5231 const char *newname
;
5234 asprintf (&tempname
, "%s.chain", name
);
5235 newname
= ggc_strdup (tempname
);
5238 chainvi
= new_var_info (fn
->static_chain_decl
, newname
);
5239 chainvi
->offset
= fi_static_chain
;
5241 chainvi
->fullsize
= vi
->fullsize
;
5242 chainvi
->is_full_var
= true;
5243 chainvi
->is_global_var
= false;
5244 gcc_assert (prev_vi
->offset
< chainvi
->offset
);
5245 prev_vi
->next
= chainvi
;
5247 insert_vi_for_tree (fn
->static_chain_decl
, chainvi
);
5250 /* Create a variable for the return var. */
5251 if (DECL_RESULT (decl
) != NULL
5252 || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl
))))
5255 const char *newname
;
5257 tree resultdecl
= decl
;
5259 if (DECL_RESULT (decl
))
5260 resultdecl
= DECL_RESULT (decl
);
5262 asprintf (&tempname
, "%s.result", name
);
5263 newname
= ggc_strdup (tempname
);
5266 resultvi
= new_var_info (resultdecl
, newname
);
5267 resultvi
->offset
= fi_result
;
5269 resultvi
->fullsize
= vi
->fullsize
;
5270 resultvi
->is_full_var
= true;
5271 if (DECL_RESULT (decl
))
5272 resultvi
->may_have_pointers
= true;
5273 gcc_assert (prev_vi
->offset
< resultvi
->offset
);
5274 prev_vi
->next
= resultvi
;
5276 if (DECL_RESULT (decl
))
5277 insert_vi_for_tree (DECL_RESULT (decl
), resultvi
);
5280 /* Set up variables for each argument. */
5281 arg
= DECL_ARGUMENTS (decl
);
5282 for (i
= 0; i
< num_args
; i
++)
5285 const char *newname
;
5287 tree argdecl
= decl
;
5292 asprintf (&tempname
, "%s.arg%d", name
, i
);
5293 newname
= ggc_strdup (tempname
);
5296 argvi
= new_var_info (argdecl
, newname
);
5297 argvi
->offset
= fi_parm_base
+ i
;
5299 argvi
->is_full_var
= true;
5300 argvi
->fullsize
= vi
->fullsize
;
5302 argvi
->may_have_pointers
= true;
5303 gcc_assert (prev_vi
->offset
< argvi
->offset
);
5304 prev_vi
->next
= argvi
;
5308 insert_vi_for_tree (arg
, argvi
);
5309 arg
= DECL_CHAIN (arg
);
5313 /* Add one representative for all further args. */
5317 const char *newname
;
5321 asprintf (&tempname
, "%s.varargs", name
);
5322 newname
= ggc_strdup (tempname
);
5325 /* We need sth that can be pointed to for va_start. */
5326 decl
= build_fake_var_decl (ptr_type_node
);
5328 argvi
= new_var_info (decl
, newname
);
5329 argvi
->offset
= fi_parm_base
+ num_args
;
5331 argvi
->is_full_var
= true;
5332 argvi
->is_heap_var
= true;
5333 argvi
->fullsize
= vi
->fullsize
;
5334 gcc_assert (prev_vi
->offset
< argvi
->offset
);
5335 prev_vi
->next
= argvi
;
5343 /* Return true if FIELDSTACK contains fields that overlap.
5344 FIELDSTACK is assumed to be sorted by offset. */
5347 check_for_overlaps (VEC (fieldoff_s
,heap
) *fieldstack
)
5349 fieldoff_s
*fo
= NULL
;
5351 HOST_WIDE_INT lastoffset
= -1;
5353 FOR_EACH_VEC_ELT (fieldoff_s
, fieldstack
, i
, fo
)
5355 if (fo
->offset
== lastoffset
)
5357 lastoffset
= fo
->offset
;
5362 /* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
5363 This will also create any varinfo structures necessary for fields
5367 create_variable_info_for_1 (tree decl
, const char *name
)
5369 varinfo_t vi
, newvi
;
5370 tree decl_type
= TREE_TYPE (decl
);
5371 tree declsize
= DECL_P (decl
) ? DECL_SIZE (decl
) : TYPE_SIZE (decl_type
);
5372 VEC (fieldoff_s
,heap
) *fieldstack
= NULL
;
5377 || !host_integerp (declsize
, 1))
5379 vi
= new_var_info (decl
, name
);
5383 vi
->is_unknown_size_var
= true;
5384 vi
->is_full_var
= true;
5385 vi
->may_have_pointers
= true;
5389 /* Collect field information. */
5390 if (use_field_sensitive
5391 && var_can_have_subvars (decl
)
5392 /* ??? Force us to not use subfields for global initializers
5393 in IPA mode. Else we'd have to parse arbitrary initializers. */
5395 && is_global_var (decl
)
5396 && DECL_INITIAL (decl
)))
5398 fieldoff_s
*fo
= NULL
;
5399 bool notokay
= false;
5402 push_fields_onto_fieldstack (decl_type
, &fieldstack
, 0);
5404 for (i
= 0; !notokay
&& VEC_iterate (fieldoff_s
, fieldstack
, i
, fo
); i
++)
5405 if (fo
->has_unknown_size
5412 /* We can't sort them if we have a field with a variable sized type,
5413 which will make notokay = true. In that case, we are going to return
5414 without creating varinfos for the fields anyway, so sorting them is a
5418 sort_fieldstack (fieldstack
);
5419 /* Due to some C++ FE issues, like PR 22488, we might end up
5420 what appear to be overlapping fields even though they,
5421 in reality, do not overlap. Until the C++ FE is fixed,
5422 we will simply disable field-sensitivity for these cases. */
5423 notokay
= check_for_overlaps (fieldstack
);
5427 VEC_free (fieldoff_s
, heap
, fieldstack
);
5430 /* If we didn't end up collecting sub-variables create a full
5431 variable for the decl. */
5432 if (VEC_length (fieldoff_s
, fieldstack
) <= 1
5433 || VEC_length (fieldoff_s
, fieldstack
) > MAX_FIELDS_FOR_FIELD_SENSITIVE
)
5435 vi
= new_var_info (decl
, name
);
5437 vi
->may_have_pointers
= true;
5438 vi
->fullsize
= TREE_INT_CST_LOW (declsize
);
5439 vi
->size
= vi
->fullsize
;
5440 vi
->is_full_var
= true;
5441 VEC_free (fieldoff_s
, heap
, fieldstack
);
5445 vi
= new_var_info (decl
, name
);
5446 vi
->fullsize
= TREE_INT_CST_LOW (declsize
);
5447 for (i
= 0, newvi
= vi
;
5448 VEC_iterate (fieldoff_s
, fieldstack
, i
, fo
);
5449 ++i
, newvi
= newvi
->next
)
5451 const char *newname
= "NULL";
5456 asprintf (&tempname
, "%s." HOST_WIDE_INT_PRINT_DEC
5457 "+" HOST_WIDE_INT_PRINT_DEC
, name
, fo
->offset
, fo
->size
);
5458 newname
= ggc_strdup (tempname
);
5461 newvi
->name
= newname
;
5462 newvi
->offset
= fo
->offset
;
5463 newvi
->size
= fo
->size
;
5464 newvi
->fullsize
= vi
->fullsize
;
5465 newvi
->may_have_pointers
= fo
->may_have_pointers
;
5466 newvi
->only_restrict_pointers
= fo
->only_restrict_pointers
;
5467 if (i
+ 1 < VEC_length (fieldoff_s
, fieldstack
))
5468 newvi
->next
= new_var_info (decl
, name
);
5471 VEC_free (fieldoff_s
, heap
, fieldstack
);
5477 create_variable_info_for (tree decl
, const char *name
)
5479 varinfo_t vi
= create_variable_info_for_1 (decl
, name
);
5480 unsigned int id
= vi
->id
;
5482 insert_vi_for_tree (decl
, vi
);
5484 if (TREE_CODE (decl
) != VAR_DECL
)
5487 /* Create initial constraints for globals. */
5488 for (; vi
; vi
= vi
->next
)
5490 if (!vi
->may_have_pointers
5491 || !vi
->is_global_var
)
5494 /* Mark global restrict qualified pointers. */
5495 if ((POINTER_TYPE_P (TREE_TYPE (decl
))
5496 && TYPE_RESTRICT (TREE_TYPE (decl
)))
5497 || vi
->only_restrict_pointers
)
5498 make_constraint_from_restrict (vi
, "GLOBAL_RESTRICT");
5500 /* In non-IPA mode the initializer from nonlocal is all we need. */
5502 || DECL_HARD_REGISTER (decl
))
5503 make_copy_constraint (vi
, nonlocal_id
);
5507 struct varpool_node
*vnode
= varpool_get_node (decl
);
5509 /* For escaped variables initialize them from nonlocal. */
5510 if (!varpool_all_refs_explicit_p (vnode
))
5511 make_copy_constraint (vi
, nonlocal_id
);
5513 /* If this is a global variable with an initializer and we are in
5514 IPA mode generate constraints for it. */
5515 if (DECL_INITIAL (decl
))
5517 VEC (ce_s
, heap
) *rhsc
= NULL
;
5518 struct constraint_expr lhs
, *rhsp
;
5520 get_constraint_for_rhs (DECL_INITIAL (decl
), &rhsc
);
5524 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
5525 process_constraint (new_constraint (lhs
, *rhsp
));
5526 /* If this is a variable that escapes from the unit
5527 the initializer escapes as well. */
5528 if (!varpool_all_refs_explicit_p (vnode
))
5530 lhs
.var
= escaped_id
;
5533 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
5534 process_constraint (new_constraint (lhs
, *rhsp
));
5536 VEC_free (ce_s
, heap
, rhsc
);
5544 /* Print out the points-to solution for VAR to FILE. */
5547 dump_solution_for_var (FILE *file
, unsigned int var
)
5549 varinfo_t vi
= get_varinfo (var
);
5553 /* Dump the solution for unified vars anyway, this avoids difficulties
5554 in scanning dumps in the testsuite. */
5555 fprintf (file
, "%s = { ", vi
->name
);
5556 vi
= get_varinfo (find (var
));
5557 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, i
, bi
)
5558 fprintf (file
, "%s ", get_varinfo (i
)->name
);
5559 fprintf (file
, "}");
5561 /* But note when the variable was unified. */
5563 fprintf (file
, " same as %s", vi
->name
);
5565 fprintf (file
, "\n");
5568 /* Print the points-to solution for VAR to stdout. */
5571 debug_solution_for_var (unsigned int var
)
5573 dump_solution_for_var (stdout
, var
);
5576 /* Create varinfo structures for all of the variables in the
5577 function for intraprocedural mode. */
5580 intra_create_variable_infos (void)
5584 /* For each incoming pointer argument arg, create the constraint ARG
5585 = NONLOCAL or a dummy variable if it is a restrict qualified
5586 passed-by-reference argument. */
5587 for (t
= DECL_ARGUMENTS (current_function_decl
); t
; t
= DECL_CHAIN (t
))
5591 /* For restrict qualified pointers to objects passed by
5592 reference build a real representative for the pointed-to object.
5593 Treat restrict qualified references the same. */
5594 if (TYPE_RESTRICT (TREE_TYPE (t
))
5595 && ((DECL_BY_REFERENCE (t
) && POINTER_TYPE_P (TREE_TYPE (t
)))
5596 || TREE_CODE (TREE_TYPE (t
)) == REFERENCE_TYPE
))
5598 struct constraint_expr lhsc
, rhsc
;
5600 tree heapvar
= build_fake_var_decl (TREE_TYPE (TREE_TYPE (t
)));
5601 DECL_EXTERNAL (heapvar
) = 1;
5602 vi
= create_variable_info_for_1 (heapvar
, "PARM_NOALIAS");
5603 insert_vi_for_tree (heapvar
, vi
);
5604 lhsc
.var
= get_vi_for_tree (t
)->id
;
5608 rhsc
.type
= ADDRESSOF
;
5610 process_constraint (new_constraint (lhsc
, rhsc
));
5611 vi
->is_restrict_var
= 1;
5612 for (; vi
; vi
= vi
->next
)
5613 if (vi
->may_have_pointers
)
5615 if (vi
->only_restrict_pointers
)
5616 make_constraint_from_restrict (vi
, "GLOBAL_RESTRICT");
5617 make_copy_constraint (vi
, nonlocal_id
);
5622 for (p
= get_vi_for_tree (t
); p
; p
= p
->next
)
5624 if (p
->may_have_pointers
)
5625 make_constraint_from (p
, nonlocal_id
);
5626 if (p
->only_restrict_pointers
)
5627 make_constraint_from_restrict (p
, "PARM_RESTRICT");
5629 if (POINTER_TYPE_P (TREE_TYPE (t
))
5630 && TYPE_RESTRICT (TREE_TYPE (t
)))
5631 make_constraint_from_restrict (get_vi_for_tree (t
), "PARM_RESTRICT");
5634 /* Add a constraint for a result decl that is passed by reference. */
5635 if (DECL_RESULT (cfun
->decl
)
5636 && DECL_BY_REFERENCE (DECL_RESULT (cfun
->decl
)))
5638 varinfo_t p
, result_vi
= get_vi_for_tree (DECL_RESULT (cfun
->decl
));
5640 for (p
= result_vi
; p
; p
= p
->next
)
5641 make_constraint_from (p
, nonlocal_id
);
5644 /* Add a constraint for the incoming static chain parameter. */
5645 if (cfun
->static_chain_decl
!= NULL_TREE
)
5647 varinfo_t p
, chain_vi
= get_vi_for_tree (cfun
->static_chain_decl
);
5649 for (p
= chain_vi
; p
; p
= p
->next
)
5650 make_constraint_from (p
, nonlocal_id
);
5654 /* Structure used to put solution bitmaps in a hashtable so they can
5655 be shared among variables with the same points-to set. */
5657 typedef struct shared_bitmap_info
5661 } *shared_bitmap_info_t
;
5662 typedef const struct shared_bitmap_info
*const_shared_bitmap_info_t
;
5664 static htab_t shared_bitmap_table
;
5666 /* Hash function for a shared_bitmap_info_t */
5669 shared_bitmap_hash (const void *p
)
5671 const_shared_bitmap_info_t
const bi
= (const_shared_bitmap_info_t
) p
;
5672 return bi
->hashcode
;
5675 /* Equality function for two shared_bitmap_info_t's. */
5678 shared_bitmap_eq (const void *p1
, const void *p2
)
5680 const_shared_bitmap_info_t
const sbi1
= (const_shared_bitmap_info_t
) p1
;
5681 const_shared_bitmap_info_t
const sbi2
= (const_shared_bitmap_info_t
) p2
;
5682 return bitmap_equal_p (sbi1
->pt_vars
, sbi2
->pt_vars
);
5685 /* Lookup a bitmap in the shared bitmap hashtable, and return an already
5686 existing instance if there is one, NULL otherwise. */
5689 shared_bitmap_lookup (bitmap pt_vars
)
5692 struct shared_bitmap_info sbi
;
5694 sbi
.pt_vars
= pt_vars
;
5695 sbi
.hashcode
= bitmap_hash (pt_vars
);
5697 slot
= htab_find_slot_with_hash (shared_bitmap_table
, &sbi
,
5698 sbi
.hashcode
, NO_INSERT
);
5702 return ((shared_bitmap_info_t
) *slot
)->pt_vars
;
5706 /* Add a bitmap to the shared bitmap hashtable. */
5709 shared_bitmap_add (bitmap pt_vars
)
5712 shared_bitmap_info_t sbi
= XNEW (struct shared_bitmap_info
);
5714 sbi
->pt_vars
= pt_vars
;
5715 sbi
->hashcode
= bitmap_hash (pt_vars
);
5717 slot
= htab_find_slot_with_hash (shared_bitmap_table
, sbi
,
5718 sbi
->hashcode
, INSERT
);
5719 gcc_assert (!*slot
);
5720 *slot
= (void *) sbi
;
5724 /* Set bits in INTO corresponding to the variable uids in solution set FROM. */
5727 set_uids_in_ptset (bitmap into
, bitmap from
, struct pt_solution
*pt
)
5732 EXECUTE_IF_SET_IN_BITMAP (from
, 0, i
, bi
)
5734 varinfo_t vi
= get_varinfo (i
);
5736 /* The only artificial variables that are allowed in a may-alias
5737 set are heap variables. */
5738 if (vi
->is_artificial_var
&& !vi
->is_heap_var
)
5741 if (TREE_CODE (vi
->decl
) == VAR_DECL
5742 || TREE_CODE (vi
->decl
) == PARM_DECL
5743 || TREE_CODE (vi
->decl
) == RESULT_DECL
)
5745 /* If we are in IPA mode we will not recompute points-to
5746 sets after inlining so make sure they stay valid. */
5748 && !DECL_PT_UID_SET_P (vi
->decl
))
5749 SET_DECL_PT_UID (vi
->decl
, DECL_UID (vi
->decl
));
5751 /* Add the decl to the points-to set. Note that the points-to
5752 set contains global variables. */
5753 bitmap_set_bit (into
, DECL_PT_UID (vi
->decl
));
5754 if (vi
->is_global_var
)
5755 pt
->vars_contains_global
= true;
5761 /* Compute the points-to solution *PT for the variable VI. */
5764 find_what_var_points_to (varinfo_t orig_vi
, struct pt_solution
*pt
)
5768 bitmap finished_solution
;
5772 memset (pt
, 0, sizeof (struct pt_solution
));
5774 /* This variable may have been collapsed, let's get the real
5776 vi
= get_varinfo (find (orig_vi
->id
));
5778 /* Translate artificial variables into SSA_NAME_PTR_INFO
5780 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, i
, bi
)
5782 varinfo_t vi
= get_varinfo (i
);
5784 if (vi
->is_artificial_var
)
5786 if (vi
->id
== nothing_id
)
5788 else if (vi
->id
== escaped_id
)
5791 pt
->ipa_escaped
= 1;
5795 else if (vi
->id
== nonlocal_id
)
5797 else if (vi
->is_heap_var
)
5798 /* We represent heapvars in the points-to set properly. */
5800 else if (vi
->id
== readonly_id
)
5803 else if (vi
->id
== anything_id
5804 || vi
->id
== integer_id
)
5807 if (vi
->is_restrict_var
)
5808 pt
->vars_contains_restrict
= true;
5811 /* Instead of doing extra work, simply do not create
5812 elaborate points-to information for pt_anything pointers. */
5814 && (orig_vi
->is_artificial_var
5815 || !pt
->vars_contains_restrict
))
5818 /* Share the final set of variables when possible. */
5819 finished_solution
= BITMAP_GGC_ALLOC ();
5820 stats
.points_to_sets_created
++;
5822 set_uids_in_ptset (finished_solution
, vi
->solution
, pt
);
5823 result
= shared_bitmap_lookup (finished_solution
);
5826 shared_bitmap_add (finished_solution
);
5827 pt
->vars
= finished_solution
;
5832 bitmap_clear (finished_solution
);
5836 /* Given a pointer variable P, fill in its points-to set. */
5839 find_what_p_points_to (tree p
)
5841 struct ptr_info_def
*pi
;
5845 /* For parameters, get at the points-to set for the actual parm
5847 if (TREE_CODE (p
) == SSA_NAME
5848 && (TREE_CODE (SSA_NAME_VAR (p
)) == PARM_DECL
5849 || TREE_CODE (SSA_NAME_VAR (p
)) == RESULT_DECL
)
5850 && SSA_NAME_IS_DEFAULT_DEF (p
))
5851 lookup_p
= SSA_NAME_VAR (p
);
5853 vi
= lookup_vi_for_tree (lookup_p
);
5857 pi
= get_ptr_info (p
);
5858 find_what_var_points_to (vi
, &pi
->pt
);
5862 /* Query statistics for points-to solutions. */
5865 unsigned HOST_WIDE_INT pt_solution_includes_may_alias
;
5866 unsigned HOST_WIDE_INT pt_solution_includes_no_alias
;
5867 unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias
;
5868 unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias
;
5872 dump_pta_stats (FILE *s
)
5874 fprintf (s
, "\nPTA query stats:\n");
5875 fprintf (s
, " pt_solution_includes: "
5876 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
5877 HOST_WIDE_INT_PRINT_DEC
" queries\n",
5878 pta_stats
.pt_solution_includes_no_alias
,
5879 pta_stats
.pt_solution_includes_no_alias
5880 + pta_stats
.pt_solution_includes_may_alias
);
5881 fprintf (s
, " pt_solutions_intersect: "
5882 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
5883 HOST_WIDE_INT_PRINT_DEC
" queries\n",
5884 pta_stats
.pt_solutions_intersect_no_alias
,
5885 pta_stats
.pt_solutions_intersect_no_alias
5886 + pta_stats
.pt_solutions_intersect_may_alias
);
5890 /* Reset the points-to solution *PT to a conservative default
5891 (point to anything). */
5894 pt_solution_reset (struct pt_solution
*pt
)
5896 memset (pt
, 0, sizeof (struct pt_solution
));
5897 pt
->anything
= true;
5900 /* Set the points-to solution *PT to point only to the variables
5901 in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
5902 global variables and VARS_CONTAINS_RESTRICT specifies whether
5903 it contains restrict tag variables. */
5906 pt_solution_set (struct pt_solution
*pt
, bitmap vars
,
5907 bool vars_contains_global
, bool vars_contains_restrict
)
5909 memset (pt
, 0, sizeof (struct pt_solution
));
5911 pt
->vars_contains_global
= vars_contains_global
;
5912 pt
->vars_contains_restrict
= vars_contains_restrict
;
5915 /* Set the points-to solution *PT to point only to the variable VAR. */
5918 pt_solution_set_var (struct pt_solution
*pt
, tree var
)
5920 memset (pt
, 0, sizeof (struct pt_solution
));
5921 pt
->vars
= BITMAP_GGC_ALLOC ();
5922 bitmap_set_bit (pt
->vars
, DECL_PT_UID (var
));
5923 pt
->vars_contains_global
= is_global_var (var
);
5926 /* Computes the union of the points-to solutions *DEST and *SRC and
5927 stores the result in *DEST. This changes the points-to bitmap
5928 of *DEST and thus may not be used if that might be shared.
5929 The points-to bitmap of *SRC and *DEST will not be shared after
5930 this function if they were not before. */
5933 pt_solution_ior_into (struct pt_solution
*dest
, struct pt_solution
*src
)
5935 dest
->anything
|= src
->anything
;
5938 pt_solution_reset (dest
);
5942 dest
->nonlocal
|= src
->nonlocal
;
5943 dest
->escaped
|= src
->escaped
;
5944 dest
->ipa_escaped
|= src
->ipa_escaped
;
5945 dest
->null
|= src
->null
;
5946 dest
->vars_contains_global
|= src
->vars_contains_global
;
5947 dest
->vars_contains_restrict
|= src
->vars_contains_restrict
;
5952 dest
->vars
= BITMAP_GGC_ALLOC ();
5953 bitmap_ior_into (dest
->vars
, src
->vars
);
5956 /* Return true if the points-to solution *PT is empty. */
5959 pt_solution_empty_p (struct pt_solution
*pt
)
5966 && !bitmap_empty_p (pt
->vars
))
5969 /* If the solution includes ESCAPED, check if that is empty. */
5971 && !pt_solution_empty_p (&cfun
->gimple_df
->escaped
))
5974 /* If the solution includes ESCAPED, check if that is empty. */
5976 && !pt_solution_empty_p (&ipa_escaped_pt
))
5982 /* Return true if the points-to solution *PT only point to a single var, and
5983 return the var uid in *UID. */
5986 pt_solution_singleton_p (struct pt_solution
*pt
, unsigned *uid
)
5988 if (pt
->anything
|| pt
->nonlocal
|| pt
->escaped
|| pt
->ipa_escaped
5989 || pt
->null
|| pt
->vars
== NULL
5990 || !bitmap_single_bit_set_p (pt
->vars
))
5993 *uid
= bitmap_first_set_bit (pt
->vars
);
5997 /* Return true if the points-to solution *PT includes global memory. */
6000 pt_solution_includes_global (struct pt_solution
*pt
)
6004 || pt
->vars_contains_global
)
6008 return pt_solution_includes_global (&cfun
->gimple_df
->escaped
);
6010 if (pt
->ipa_escaped
)
6011 return pt_solution_includes_global (&ipa_escaped_pt
);
6013 /* ??? This predicate is not correct for the IPA-PTA solution
6014 as we do not properly distinguish between unit escape points
6015 and global variables. */
6016 if (cfun
->gimple_df
->ipa_pta
)
6022 /* Return true if the points-to solution *PT includes the variable
6023 declaration DECL. */
6026 pt_solution_includes_1 (struct pt_solution
*pt
, const_tree decl
)
6032 && is_global_var (decl
))
6036 && bitmap_bit_p (pt
->vars
, DECL_PT_UID (decl
)))
6039 /* If the solution includes ESCAPED, check it. */
6041 && pt_solution_includes_1 (&cfun
->gimple_df
->escaped
, decl
))
6044 /* If the solution includes ESCAPED, check it. */
6046 && pt_solution_includes_1 (&ipa_escaped_pt
, decl
))
6053 pt_solution_includes (struct pt_solution
*pt
, const_tree decl
)
6055 bool res
= pt_solution_includes_1 (pt
, decl
);
6057 ++pta_stats
.pt_solution_includes_may_alias
;
6059 ++pta_stats
.pt_solution_includes_no_alias
;
6063 /* Return true if both points-to solutions PT1 and PT2 have a non-empty
6067 pt_solutions_intersect_1 (struct pt_solution
*pt1
, struct pt_solution
*pt2
)
6069 if (pt1
->anything
|| pt2
->anything
)
6072 /* If either points to unknown global memory and the other points to
6073 any global memory they alias. */
6076 || pt2
->vars_contains_global
))
6078 && pt1
->vars_contains_global
))
6081 /* Check the escaped solution if required. */
6082 if ((pt1
->escaped
|| pt2
->escaped
)
6083 && !pt_solution_empty_p (&cfun
->gimple_df
->escaped
))
6085 /* If both point to escaped memory and that solution
6086 is not empty they alias. */
6087 if (pt1
->escaped
&& pt2
->escaped
)
6090 /* If either points to escaped memory see if the escaped solution
6091 intersects with the other. */
6093 && pt_solutions_intersect_1 (&cfun
->gimple_df
->escaped
, pt2
))
6095 && pt_solutions_intersect_1 (&cfun
->gimple_df
->escaped
, pt1
)))
6099 /* Check the escaped solution if required.
6100 ??? Do we need to check the local against the IPA escaped sets? */
6101 if ((pt1
->ipa_escaped
|| pt2
->ipa_escaped
)
6102 && !pt_solution_empty_p (&ipa_escaped_pt
))
6104 /* If both point to escaped memory and that solution
6105 is not empty they alias. */
6106 if (pt1
->ipa_escaped
&& pt2
->ipa_escaped
)
6109 /* If either points to escaped memory see if the escaped solution
6110 intersects with the other. */
6111 if ((pt1
->ipa_escaped
6112 && pt_solutions_intersect_1 (&ipa_escaped_pt
, pt2
))
6113 || (pt2
->ipa_escaped
6114 && pt_solutions_intersect_1 (&ipa_escaped_pt
, pt1
)))
6118 /* Now both pointers alias if their points-to solution intersects. */
6121 && bitmap_intersect_p (pt1
->vars
, pt2
->vars
));
6125 pt_solutions_intersect (struct pt_solution
*pt1
, struct pt_solution
*pt2
)
6127 bool res
= pt_solutions_intersect_1 (pt1
, pt2
);
6129 ++pta_stats
.pt_solutions_intersect_may_alias
;
6131 ++pta_stats
.pt_solutions_intersect_no_alias
;
6135 /* Return true if both points-to solutions PT1 and PT2 for two restrict
6136 qualified pointers are possibly based on the same pointer. */
6139 pt_solutions_same_restrict_base (struct pt_solution
*pt1
,
6140 struct pt_solution
*pt2
)
6142 /* If we deal with points-to solutions of two restrict qualified
6143 pointers solely rely on the pointed-to variable bitmap intersection.
6144 For two pointers that are based on each other the bitmaps will
6146 if (pt1
->vars_contains_restrict
6147 && pt2
->vars_contains_restrict
)
6149 gcc_assert (pt1
->vars
&& pt2
->vars
);
6150 return bitmap_intersect_p (pt1
->vars
, pt2
->vars
);
6157 /* Dump points-to information to OUTFILE. */
6160 dump_sa_points_to_info (FILE *outfile
)
6164 fprintf (outfile
, "\nPoints-to sets\n\n");
6166 if (dump_flags
& TDF_STATS
)
6168 fprintf (outfile
, "Stats:\n");
6169 fprintf (outfile
, "Total vars: %d\n", stats
.total_vars
);
6170 fprintf (outfile
, "Non-pointer vars: %d\n",
6171 stats
.nonpointer_vars
);
6172 fprintf (outfile
, "Statically unified vars: %d\n",
6173 stats
.unified_vars_static
);
6174 fprintf (outfile
, "Dynamically unified vars: %d\n",
6175 stats
.unified_vars_dynamic
);
6176 fprintf (outfile
, "Iterations: %d\n", stats
.iterations
);
6177 fprintf (outfile
, "Number of edges: %d\n", stats
.num_edges
);
6178 fprintf (outfile
, "Number of implicit edges: %d\n",
6179 stats
.num_implicit_edges
);
6182 for (i
= 0; i
< VEC_length (varinfo_t
, varmap
); i
++)
6184 varinfo_t vi
= get_varinfo (i
);
6185 if (!vi
->may_have_pointers
)
6187 dump_solution_for_var (outfile
, i
);
6192 /* Debug points-to information to stderr. */
6195 debug_sa_points_to_info (void)
6197 dump_sa_points_to_info (stderr
);
6201 /* Initialize the always-existing constraint variables for NULL
6202 ANYTHING, READONLY, and INTEGER */
6205 init_base_vars (void)
6207 struct constraint_expr lhs
, rhs
;
6208 varinfo_t var_anything
;
6209 varinfo_t var_nothing
;
6210 varinfo_t var_readonly
;
6211 varinfo_t var_escaped
;
6212 varinfo_t var_nonlocal
;
6213 varinfo_t var_storedanything
;
6214 varinfo_t var_integer
;
6216 /* Create the NULL variable, used to represent that a variable points
6218 var_nothing
= new_var_info (NULL_TREE
, "NULL");
6219 gcc_assert (var_nothing
->id
== nothing_id
);
6220 var_nothing
->is_artificial_var
= 1;
6221 var_nothing
->offset
= 0;
6222 var_nothing
->size
= ~0;
6223 var_nothing
->fullsize
= ~0;
6224 var_nothing
->is_special_var
= 1;
6225 var_nothing
->may_have_pointers
= 0;
6226 var_nothing
->is_global_var
= 0;
6228 /* Create the ANYTHING variable, used to represent that a variable
6229 points to some unknown piece of memory. */
6230 var_anything
= new_var_info (NULL_TREE
, "ANYTHING");
6231 gcc_assert (var_anything
->id
== anything_id
);
6232 var_anything
->is_artificial_var
= 1;
6233 var_anything
->size
= ~0;
6234 var_anything
->offset
= 0;
6235 var_anything
->next
= NULL
;
6236 var_anything
->fullsize
= ~0;
6237 var_anything
->is_special_var
= 1;
6239 /* Anything points to anything. This makes deref constraints just
6240 work in the presence of linked list and other p = *p type loops,
6241 by saying that *ANYTHING = ANYTHING. */
6243 lhs
.var
= anything_id
;
6245 rhs
.type
= ADDRESSOF
;
6246 rhs
.var
= anything_id
;
6249 /* This specifically does not use process_constraint because
6250 process_constraint ignores all anything = anything constraints, since all
6251 but this one are redundant. */
6252 VEC_safe_push (constraint_t
, heap
, constraints
, new_constraint (lhs
, rhs
));
6254 /* Create the READONLY variable, used to represent that a variable
6255 points to readonly memory. */
6256 var_readonly
= new_var_info (NULL_TREE
, "READONLY");
6257 gcc_assert (var_readonly
->id
== readonly_id
);
6258 var_readonly
->is_artificial_var
= 1;
6259 var_readonly
->offset
= 0;
6260 var_readonly
->size
= ~0;
6261 var_readonly
->fullsize
= ~0;
6262 var_readonly
->next
= NULL
;
6263 var_readonly
->is_special_var
= 1;
6265 /* readonly memory points to anything, in order to make deref
6266 easier. In reality, it points to anything the particular
6267 readonly variable can point to, but we don't track this
6270 lhs
.var
= readonly_id
;
6272 rhs
.type
= ADDRESSOF
;
6273 rhs
.var
= readonly_id
; /* FIXME */
6275 process_constraint (new_constraint (lhs
, rhs
));
6277 /* Create the ESCAPED variable, used to represent the set of escaped
6279 var_escaped
= new_var_info (NULL_TREE
, "ESCAPED");
6280 gcc_assert (var_escaped
->id
== escaped_id
);
6281 var_escaped
->is_artificial_var
= 1;
6282 var_escaped
->offset
= 0;
6283 var_escaped
->size
= ~0;
6284 var_escaped
->fullsize
= ~0;
6285 var_escaped
->is_special_var
= 0;
6287 /* Create the NONLOCAL variable, used to represent the set of nonlocal
6289 var_nonlocal
= new_var_info (NULL_TREE
, "NONLOCAL");
6290 gcc_assert (var_nonlocal
->id
== nonlocal_id
);
6291 var_nonlocal
->is_artificial_var
= 1;
6292 var_nonlocal
->offset
= 0;
6293 var_nonlocal
->size
= ~0;
6294 var_nonlocal
->fullsize
= ~0;
6295 var_nonlocal
->is_special_var
= 1;
6297 /* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
6299 lhs
.var
= escaped_id
;
6302 rhs
.var
= escaped_id
;
6304 process_constraint (new_constraint (lhs
, rhs
));
6306 /* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
6307 whole variable escapes. */
6309 lhs
.var
= escaped_id
;
6312 rhs
.var
= escaped_id
;
6313 rhs
.offset
= UNKNOWN_OFFSET
;
6314 process_constraint (new_constraint (lhs
, rhs
));
6316 /* *ESCAPED = NONLOCAL. This is true because we have to assume
6317 everything pointed to by escaped points to what global memory can
6320 lhs
.var
= escaped_id
;
6323 rhs
.var
= nonlocal_id
;
6325 process_constraint (new_constraint (lhs
, rhs
));
6327 /* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
6328 global memory may point to global memory and escaped memory. */
6330 lhs
.var
= nonlocal_id
;
6332 rhs
.type
= ADDRESSOF
;
6333 rhs
.var
= nonlocal_id
;
6335 process_constraint (new_constraint (lhs
, rhs
));
6336 rhs
.type
= ADDRESSOF
;
6337 rhs
.var
= escaped_id
;
6339 process_constraint (new_constraint (lhs
, rhs
));
6341 /* Create the STOREDANYTHING variable, used to represent the set of
6342 variables stored to *ANYTHING. */
6343 var_storedanything
= new_var_info (NULL_TREE
, "STOREDANYTHING");
6344 gcc_assert (var_storedanything
->id
== storedanything_id
);
6345 var_storedanything
->is_artificial_var
= 1;
6346 var_storedanything
->offset
= 0;
6347 var_storedanything
->size
= ~0;
6348 var_storedanything
->fullsize
= ~0;
6349 var_storedanything
->is_special_var
= 0;
6351 /* Create the INTEGER variable, used to represent that a variable points
6352 to what an INTEGER "points to". */
6353 var_integer
= new_var_info (NULL_TREE
, "INTEGER");
6354 gcc_assert (var_integer
->id
== integer_id
);
6355 var_integer
->is_artificial_var
= 1;
6356 var_integer
->size
= ~0;
6357 var_integer
->fullsize
= ~0;
6358 var_integer
->offset
= 0;
6359 var_integer
->next
= NULL
;
6360 var_integer
->is_special_var
= 1;
6362 /* INTEGER = ANYTHING, because we don't know where a dereference of
6363 a random integer will point to. */
6365 lhs
.var
= integer_id
;
6367 rhs
.type
= ADDRESSOF
;
6368 rhs
.var
= anything_id
;
6370 process_constraint (new_constraint (lhs
, rhs
));
6373 /* Initialize things necessary to perform PTA */
6376 init_alias_vars (void)
6378 use_field_sensitive
= (MAX_FIELDS_FOR_FIELD_SENSITIVE
> 1);
6380 bitmap_obstack_initialize (&pta_obstack
);
6381 bitmap_obstack_initialize (&oldpta_obstack
);
6382 bitmap_obstack_initialize (&predbitmap_obstack
);
6384 constraint_pool
= create_alloc_pool ("Constraint pool",
6385 sizeof (struct constraint
), 30);
6386 variable_info_pool
= create_alloc_pool ("Variable info pool",
6387 sizeof (struct variable_info
), 30);
6388 constraints
= VEC_alloc (constraint_t
, heap
, 8);
6389 varmap
= VEC_alloc (varinfo_t
, heap
, 8);
6390 vi_for_tree
= pointer_map_create ();
6391 call_stmt_vars
= pointer_map_create ();
6393 memset (&stats
, 0, sizeof (stats
));
6394 shared_bitmap_table
= htab_create (511, shared_bitmap_hash
,
6395 shared_bitmap_eq
, free
);
6398 gcc_obstack_init (&fake_var_decl_obstack
);
6401 /* Remove the REF and ADDRESS edges from GRAPH, as well as all the
6402 predecessor edges. */
6405 remove_preds_and_fake_succs (constraint_graph_t graph
)
6409 /* Clear the implicit ref and address nodes from the successor
6411 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
6413 if (graph
->succs
[i
])
6414 bitmap_clear_range (graph
->succs
[i
], FIRST_REF_NODE
,
6415 FIRST_REF_NODE
* 2);
6418 /* Free the successor list for the non-ref nodes. */
6419 for (i
= FIRST_REF_NODE
; i
< graph
->size
; i
++)
6421 if (graph
->succs
[i
])
6422 BITMAP_FREE (graph
->succs
[i
]);
6425 /* Now reallocate the size of the successor list as, and blow away
6426 the predecessor bitmaps. */
6427 graph
->size
= VEC_length (varinfo_t
, varmap
);
6428 graph
->succs
= XRESIZEVEC (bitmap
, graph
->succs
, graph
->size
);
6430 free (graph
->implicit_preds
);
6431 graph
->implicit_preds
= NULL
;
6432 free (graph
->preds
);
6433 graph
->preds
= NULL
;
6434 bitmap_obstack_release (&predbitmap_obstack
);
6437 /* Solve the constraint set. */
6440 solve_constraints (void)
6442 struct scc_info
*si
;
6446 "\nCollapsing static cycles and doing variable "
6449 init_graph (VEC_length (varinfo_t
, varmap
) * 2);
6452 fprintf (dump_file
, "Building predecessor graph\n");
6453 build_pred_graph ();
6456 fprintf (dump_file
, "Detecting pointer and location "
6458 si
= perform_var_substitution (graph
);
6461 fprintf (dump_file
, "Rewriting constraints and unifying "
6463 rewrite_constraints (graph
, si
);
6465 build_succ_graph ();
6467 free_var_substitution_info (si
);
6469 /* Attach complex constraints to graph nodes. */
6470 move_complex_constraints (graph
);
6473 fprintf (dump_file
, "Uniting pointer but not location equivalent "
6475 unite_pointer_equivalences (graph
);
6478 fprintf (dump_file
, "Finding indirect cycles\n");
6479 find_indirect_cycles (graph
);
6481 /* Implicit nodes and predecessors are no longer necessary at this
6483 remove_preds_and_fake_succs (graph
);
6485 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
6487 fprintf (dump_file
, "\n\n// The constraint graph before solve-graph "
6488 "in dot format:\n");
6489 dump_constraint_graph (dump_file
);
6490 fprintf (dump_file
, "\n\n");
6494 fprintf (dump_file
, "Solving graph\n");
6496 solve_graph (graph
);
6498 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
6500 fprintf (dump_file
, "\n\n// The constraint graph after solve-graph "
6501 "in dot format:\n");
6502 dump_constraint_graph (dump_file
);
6503 fprintf (dump_file
, "\n\n");
6507 dump_sa_points_to_info (dump_file
);
6510 /* Create points-to sets for the current function. See the comments
6511 at the start of the file for an algorithmic overview. */
6514 compute_points_to_sets (void)
6520 timevar_push (TV_TREE_PTA
);
6524 intra_create_variable_infos ();
6526 /* Now walk all statements and build the constraint set. */
6529 gimple_stmt_iterator gsi
;
6531 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6533 gimple phi
= gsi_stmt (gsi
);
6535 if (is_gimple_reg (gimple_phi_result (phi
)))
6536 find_func_aliases (phi
);
6539 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6541 gimple stmt
= gsi_stmt (gsi
);
6543 find_func_aliases (stmt
);
6549 fprintf (dump_file
, "Points-to analysis\n\nConstraints:\n\n");
6550 dump_constraints (dump_file
, 0);
6553 /* From the constraints compute the points-to sets. */
6554 solve_constraints ();
6556 /* Compute the points-to set for ESCAPED used for call-clobber analysis. */
6557 find_what_var_points_to (get_varinfo (escaped_id
),
6558 &cfun
->gimple_df
->escaped
);
6560 /* Make sure the ESCAPED solution (which is used as placeholder in
6561 other solutions) does not reference itself. This simplifies
6562 points-to solution queries. */
6563 cfun
->gimple_df
->escaped
.escaped
= 0;
6565 /* Mark escaped HEAP variables as global. */
6566 FOR_EACH_VEC_ELT (varinfo_t
, varmap
, i
, vi
)
6568 && !vi
->is_restrict_var
6569 && !vi
->is_global_var
)
6570 DECL_EXTERNAL (vi
->decl
) = vi
->is_global_var
6571 = pt_solution_includes (&cfun
->gimple_df
->escaped
, vi
->decl
);
6573 /* Compute the points-to sets for pointer SSA_NAMEs. */
6574 for (i
= 0; i
< num_ssa_names
; ++i
)
6576 tree ptr
= ssa_name (i
);
6578 && POINTER_TYPE_P (TREE_TYPE (ptr
)))
6579 find_what_p_points_to (ptr
);
6582 /* Compute the call-used/clobbered sets. */
6585 gimple_stmt_iterator gsi
;
6587 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6589 gimple stmt
= gsi_stmt (gsi
);
6590 struct pt_solution
*pt
;
6591 if (!is_gimple_call (stmt
))
6594 pt
= gimple_call_use_set (stmt
);
6595 if (gimple_call_flags (stmt
) & ECF_CONST
)
6596 memset (pt
, 0, sizeof (struct pt_solution
));
6597 else if ((vi
= lookup_call_use_vi (stmt
)) != NULL
)
6599 find_what_var_points_to (vi
, pt
);
6600 /* Escaped (and thus nonlocal) variables are always
6601 implicitly used by calls. */
6602 /* ??? ESCAPED can be empty even though NONLOCAL
6609 /* If there is nothing special about this call then
6610 we have made everything that is used also escape. */
6611 *pt
= cfun
->gimple_df
->escaped
;
6615 pt
= gimple_call_clobber_set (stmt
);
6616 if (gimple_call_flags (stmt
) & (ECF_CONST
|ECF_PURE
|ECF_NOVOPS
))
6617 memset (pt
, 0, sizeof (struct pt_solution
));
6618 else if ((vi
= lookup_call_clobber_vi (stmt
)) != NULL
)
6620 find_what_var_points_to (vi
, pt
);
6621 /* Escaped (and thus nonlocal) variables are always
6622 implicitly clobbered by calls. */
6623 /* ??? ESCAPED can be empty even though NONLOCAL
6630 /* If there is nothing special about this call then
6631 we have made everything that is used also escape. */
6632 *pt
= cfun
->gimple_df
->escaped
;
6638 timevar_pop (TV_TREE_PTA
);
6642 /* Delete created points-to sets. */
6645 delete_points_to_sets (void)
6649 htab_delete (shared_bitmap_table
);
6650 if (dump_file
&& (dump_flags
& TDF_STATS
))
6651 fprintf (dump_file
, "Points to sets created:%d\n",
6652 stats
.points_to_sets_created
);
6654 pointer_map_destroy (vi_for_tree
);
6655 pointer_map_destroy (call_stmt_vars
);
6656 bitmap_obstack_release (&pta_obstack
);
6657 VEC_free (constraint_t
, heap
, constraints
);
6659 for (i
= 0; i
< graph
->size
; i
++)
6660 VEC_free (constraint_t
, heap
, graph
->complex[i
]);
6661 free (graph
->complex);
6664 free (graph
->succs
);
6666 free (graph
->pe_rep
);
6667 free (graph
->indirect_cycles
);
6670 VEC_free (varinfo_t
, heap
, varmap
);
6671 free_alloc_pool (variable_info_pool
);
6672 free_alloc_pool (constraint_pool
);
6674 obstack_free (&fake_var_decl_obstack
, NULL
);
6678 /* Compute points-to information for every SSA_NAME pointer in the
6679 current function and compute the transitive closure of escaped
6680 variables to re-initialize the call-clobber states of local variables. */
6683 compute_may_aliases (void)
6685 if (cfun
->gimple_df
->ipa_pta
)
6689 fprintf (dump_file
, "\nNot re-computing points-to information "
6690 "because IPA points-to information is available.\n\n");
6692 /* But still dump what we have remaining it. */
6693 dump_alias_info (dump_file
);
6695 if (dump_flags
& TDF_DETAILS
)
6696 dump_referenced_vars (dump_file
);
6702 /* For each pointer P_i, determine the sets of variables that P_i may
6703 point-to. Compute the reachability set of escaped and call-used
6705 compute_points_to_sets ();
6707 /* Debugging dumps. */
6710 dump_alias_info (dump_file
);
6712 if (dump_flags
& TDF_DETAILS
)
6713 dump_referenced_vars (dump_file
);
6716 /* Deallocate memory used by aliasing data structures and the internal
6717 points-to solution. */
6718 delete_points_to_sets ();
6720 gcc_assert (!need_ssa_update_p (cfun
));
6726 gate_tree_pta (void)
6728 return flag_tree_pta
;
6731 /* A dummy pass to cause points-to information to be computed via
6732 TODO_rebuild_alias. */
6734 struct gimple_opt_pass pass_build_alias
=
6739 gate_tree_pta
, /* gate */
6743 0, /* static_pass_number */
6744 TV_NONE
, /* tv_id */
6745 PROP_cfg
| PROP_ssa
, /* properties_required */
6746 0, /* properties_provided */
6747 0, /* properties_destroyed */
6748 0, /* todo_flags_start */
6749 TODO_rebuild_alias
/* todo_flags_finish */
6753 /* A dummy pass to cause points-to information to be computed via
6754 TODO_rebuild_alias. */
6756 struct gimple_opt_pass pass_build_ealias
=
6760 "ealias", /* name */
6761 gate_tree_pta
, /* gate */
6765 0, /* static_pass_number */
6766 TV_NONE
, /* tv_id */
6767 PROP_cfg
| PROP_ssa
, /* properties_required */
6768 0, /* properties_provided */
6769 0, /* properties_destroyed */
6770 0, /* todo_flags_start */
6771 TODO_rebuild_alias
/* todo_flags_finish */
6776 /* Return true if we should execute IPA PTA. */
6782 /* Don't bother doing anything if the program has errors. */
6786 /* IPA PTA solutions for ESCAPED. */
6787 struct pt_solution ipa_escaped_pt
6788 = { true, false, false, false, false, false, false, NULL
};
6790 /* Associate node with varinfo DATA. Worker for
6791 cgraph_for_node_and_aliases. */
6793 associate_varinfo_to_alias (struct cgraph_node
*node
, void *data
)
6795 if (node
->alias
|| node
->thunk
.thunk_p
)
6796 insert_vi_for_tree (node
->decl
, (varinfo_t
)data
);
6800 /* Execute the driver for IPA PTA. */
6802 ipa_pta_execute (void)
6804 struct cgraph_node
*node
;
6805 struct varpool_node
*var
;
6812 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
6814 dump_cgraph (dump_file
);
6815 fprintf (dump_file
, "\n");
6818 /* Build the constraints. */
6819 for (node
= cgraph_nodes
; node
; node
= node
->next
)
6822 /* Nodes without a body are not interesting. Especially do not
6823 visit clones at this point for now - we get duplicate decls
6824 there for inline clones at least. */
6825 if (!cgraph_function_with_gimple_body_p (node
))
6828 gcc_assert (!node
->clone_of
);
6830 vi
= create_function_info_for (node
->decl
,
6831 alias_get_name (node
->decl
));
6832 cgraph_for_node_and_aliases (node
, associate_varinfo_to_alias
, vi
, true);
6835 /* Create constraints for global variables and their initializers. */
6836 for (var
= varpool_nodes
; var
; var
= var
->next
)
6841 get_vi_for_tree (var
->decl
);
6847 "Generating constraints for global initializers\n\n");
6848 dump_constraints (dump_file
, 0);
6849 fprintf (dump_file
, "\n");
6851 from
= VEC_length (constraint_t
, constraints
);
6853 for (node
= cgraph_nodes
; node
; node
= node
->next
)
6855 struct function
*func
;
6859 /* Nodes without a body are not interesting. */
6860 if (!cgraph_function_with_gimple_body_p (node
))
6866 "Generating constraints for %s", cgraph_node_name (node
));
6867 if (DECL_ASSEMBLER_NAME_SET_P (node
->decl
))
6868 fprintf (dump_file
, " (%s)",
6869 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node
->decl
)));
6870 fprintf (dump_file
, "\n");
6873 func
= DECL_STRUCT_FUNCTION (node
->decl
);
6874 old_func_decl
= current_function_decl
;
6876 current_function_decl
= node
->decl
;
6878 /* For externally visible or attribute used annotated functions use
6879 local constraints for their arguments.
6880 For local functions we see all callers and thus do not need initial
6881 constraints for parameters. */
6882 if (node
->reachable_from_other_partition
6883 || node
->local
.externally_visible
6886 intra_create_variable_infos ();
6888 /* We also need to make function return values escape. Nothing
6889 escapes by returning from main though. */
6890 if (!MAIN_NAME_P (DECL_NAME (node
->decl
)))
6893 fi
= lookup_vi_for_tree (node
->decl
);
6894 rvi
= first_vi_for_offset (fi
, fi_result
);
6895 if (rvi
&& rvi
->offset
== fi_result
)
6897 struct constraint_expr includes
;
6898 struct constraint_expr var
;
6899 includes
.var
= escaped_id
;
6900 includes
.offset
= 0;
6901 includes
.type
= SCALAR
;
6905 process_constraint (new_constraint (includes
, var
));
6910 /* Build constriants for the function body. */
6911 FOR_EACH_BB_FN (bb
, func
)
6913 gimple_stmt_iterator gsi
;
6915 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
6918 gimple phi
= gsi_stmt (gsi
);
6920 if (is_gimple_reg (gimple_phi_result (phi
)))
6921 find_func_aliases (phi
);
6924 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6926 gimple stmt
= gsi_stmt (gsi
);
6928 find_func_aliases (stmt
);
6929 find_func_clobbers (stmt
);
6933 current_function_decl
= old_func_decl
;
6938 fprintf (dump_file
, "\n");
6939 dump_constraints (dump_file
, from
);
6940 fprintf (dump_file
, "\n");
6942 from
= VEC_length (constraint_t
, constraints
);
6945 /* From the constraints compute the points-to sets. */
6946 solve_constraints ();
6948 /* Compute the global points-to sets for ESCAPED.
6949 ??? Note that the computed escape set is not correct
6950 for the whole unit as we fail to consider graph edges to
6951 externally visible functions. */
6952 find_what_var_points_to (get_varinfo (escaped_id
), &ipa_escaped_pt
);
6954 /* Make sure the ESCAPED solution (which is used as placeholder in
6955 other solutions) does not reference itself. This simplifies
6956 points-to solution queries. */
6957 ipa_escaped_pt
.ipa_escaped
= 0;
6959 /* Assign the points-to sets to the SSA names in the unit. */
6960 for (node
= cgraph_nodes
; node
; node
= node
->next
)
6963 struct function
*fn
;
6967 struct pt_solution uses
, clobbers
;
6968 struct cgraph_edge
*e
;
6970 /* Nodes without a body are not interesting. */
6971 if (!cgraph_function_with_gimple_body_p (node
))
6974 fn
= DECL_STRUCT_FUNCTION (node
->decl
);
6976 /* Compute the points-to sets for pointer SSA_NAMEs. */
6977 FOR_EACH_VEC_ELT (tree
, fn
->gimple_df
->ssa_names
, i
, ptr
)
6980 && POINTER_TYPE_P (TREE_TYPE (ptr
)))
6981 find_what_p_points_to (ptr
);
6984 /* Compute the call-use and call-clobber sets for all direct calls. */
6985 fi
= lookup_vi_for_tree (node
->decl
);
6986 gcc_assert (fi
->is_fn_info
);
6987 find_what_var_points_to (first_vi_for_offset (fi
, fi_clobbers
),
6989 find_what_var_points_to (first_vi_for_offset (fi
, fi_uses
), &uses
);
6990 for (e
= node
->callers
; e
; e
= e
->next_caller
)
6995 *gimple_call_clobber_set (e
->call_stmt
) = clobbers
;
6996 *gimple_call_use_set (e
->call_stmt
) = uses
;
6999 /* Compute the call-use and call-clobber sets for indirect calls
7000 and calls to external functions. */
7001 FOR_EACH_BB_FN (bb
, fn
)
7003 gimple_stmt_iterator gsi
;
7005 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
7007 gimple stmt
= gsi_stmt (gsi
);
7008 struct pt_solution
*pt
;
7012 if (!is_gimple_call (stmt
))
7015 /* Handle direct calls to external functions. */
7016 decl
= gimple_call_fndecl (stmt
);
7018 && (!(fi
= lookup_vi_for_tree (decl
))
7019 || !fi
->is_fn_info
))
7021 pt
= gimple_call_use_set (stmt
);
7022 if (gimple_call_flags (stmt
) & ECF_CONST
)
7023 memset (pt
, 0, sizeof (struct pt_solution
));
7024 else if ((vi
= lookup_call_use_vi (stmt
)) != NULL
)
7026 find_what_var_points_to (vi
, pt
);
7027 /* Escaped (and thus nonlocal) variables are always
7028 implicitly used by calls. */
7029 /* ??? ESCAPED can be empty even though NONLOCAL
7032 pt
->ipa_escaped
= 1;
7036 /* If there is nothing special about this call then
7037 we have made everything that is used also escape. */
7038 *pt
= ipa_escaped_pt
;
7042 pt
= gimple_call_clobber_set (stmt
);
7043 if (gimple_call_flags (stmt
) & (ECF_CONST
|ECF_PURE
|ECF_NOVOPS
))
7044 memset (pt
, 0, sizeof (struct pt_solution
));
7045 else if ((vi
= lookup_call_clobber_vi (stmt
)) != NULL
)
7047 find_what_var_points_to (vi
, pt
);
7048 /* Escaped (and thus nonlocal) variables are always
7049 implicitly clobbered by calls. */
7050 /* ??? ESCAPED can be empty even though NONLOCAL
7053 pt
->ipa_escaped
= 1;
7057 /* If there is nothing special about this call then
7058 we have made everything that is used also escape. */
7059 *pt
= ipa_escaped_pt
;
7064 /* Handle indirect calls. */
7066 && (fi
= get_fi_for_callee (stmt
)))
7068 /* We need to accumulate all clobbers/uses of all possible
7070 fi
= get_varinfo (find (fi
->id
));
7071 /* If we cannot constrain the set of functions we'll end up
7072 calling we end up using/clobbering everything. */
7073 if (bitmap_bit_p (fi
->solution
, anything_id
)
7074 || bitmap_bit_p (fi
->solution
, nonlocal_id
)
7075 || bitmap_bit_p (fi
->solution
, escaped_id
))
7077 pt_solution_reset (gimple_call_clobber_set (stmt
));
7078 pt_solution_reset (gimple_call_use_set (stmt
));
7084 struct pt_solution
*uses
, *clobbers
;
7086 uses
= gimple_call_use_set (stmt
);
7087 clobbers
= gimple_call_clobber_set (stmt
);
7088 memset (uses
, 0, sizeof (struct pt_solution
));
7089 memset (clobbers
, 0, sizeof (struct pt_solution
));
7090 EXECUTE_IF_SET_IN_BITMAP (fi
->solution
, 0, i
, bi
)
7092 struct pt_solution sol
;
7094 vi
= get_varinfo (i
);
7095 if (!vi
->is_fn_info
)
7097 /* ??? We could be more precise here? */
7099 uses
->ipa_escaped
= 1;
7100 clobbers
->nonlocal
= 1;
7101 clobbers
->ipa_escaped
= 1;
7105 if (!uses
->anything
)
7107 find_what_var_points_to
7108 (first_vi_for_offset (vi
, fi_uses
), &sol
);
7109 pt_solution_ior_into (uses
, &sol
);
7111 if (!clobbers
->anything
)
7113 find_what_var_points_to
7114 (first_vi_for_offset (vi
, fi_clobbers
), &sol
);
7115 pt_solution_ior_into (clobbers
, &sol
);
7123 fn
->gimple_df
->ipa_pta
= true;
7126 delete_points_to_sets ();
7133 struct simple_ipa_opt_pass pass_ipa_pta
=
7138 gate_ipa_pta
, /* gate */
7139 ipa_pta_execute
, /* execute */
7142 0, /* static_pass_number */
7143 TV_IPA_PTA
, /* tv_id */
7144 0, /* properties_required */
7145 0, /* properties_provided */
7146 0, /* properties_destroyed */
7147 0, /* todo_flags_start */
7148 TODO_update_ssa
/* todo_flags_finish */