1 /* Tree based points-to analysis
2 Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
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"
32 #include "hard-reg-set.h"
33 #include "basic-block.h"
36 #include "tree-flow.h"
37 #include "tree-inline.h"
38 #include "diagnostic.h"
44 #include "tree-pass.h"
46 #include "alloc-pool.h"
47 #include "splay-tree.h"
51 #include "pointer-set.h"
53 /* The idea behind this analyzer is to generate set constraints from the
54 program, then solve the resulting constraints in order to generate the
57 Set constraints are a way of modeling program analysis problems that
58 involve sets. They consist of an inclusion constraint language,
59 describing the variables (each variable is a set) and operations that
60 are involved on the variables, and a set of rules that derive facts
61 from these operations. To solve a system of set constraints, you derive
62 all possible facts under the rules, which gives you the correct sets
65 See "Efficient Field-sensitive pointer analysis for C" by "David
66 J. Pearce and Paul H. J. Kelly and Chris Hankin, at
67 http://citeseer.ist.psu.edu/pearce04efficient.html
69 Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
70 of C Code in a Second" by ""Nevin Heintze and Olivier Tardieu" at
71 http://citeseer.ist.psu.edu/heintze01ultrafast.html
73 There are three types of real constraint expressions, DEREF,
74 ADDRESSOF, and SCALAR. Each constraint expression consists
75 of a constraint type, a variable, and an offset.
77 SCALAR is a constraint expression type used to represent x, whether
78 it appears on the LHS or the RHS of a statement.
79 DEREF is a constraint expression type used to represent *x, whether
80 it appears on the LHS or the RHS of a statement.
81 ADDRESSOF is a constraint expression used to represent &x, whether
82 it appears on the LHS or the RHS of a statement.
84 Each pointer variable in the program is assigned an integer id, and
85 each field of a structure variable is assigned an integer id as well.
87 Structure variables are linked to their list of fields through a "next
88 field" in each variable that points to the next field in offset
90 Each variable for a structure field has
92 1. "size", that tells the size in bits of that field.
93 2. "fullsize, that tells the size in bits of the entire structure.
94 3. "offset", that tells the offset in bits from the beginning of the
95 structure to this field.
107 foo.a -> id 1, size 32, offset 0, fullsize 64, next foo.b
108 foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
109 bar -> id 3, size 32, offset 0, fullsize 32, next NULL
112 In order to solve the system of set constraints, the following is
115 1. Each constraint variable x has a solution set associated with it,
118 2. Constraints are separated into direct, copy, and complex.
119 Direct constraints are ADDRESSOF constraints that require no extra
120 processing, such as P = &Q
121 Copy constraints are those of the form P = Q.
122 Complex constraints are all the constraints involving dereferences
123 and offsets (including offsetted copies).
125 3. All direct constraints of the form P = &Q are processed, such
126 that Q is added to Sol(P)
128 4. All complex constraints for a given constraint variable are stored in a
129 linked list attached to that variable's node.
131 5. A directed graph is built out of the copy constraints. Each
132 constraint variable is a node in the graph, and an edge from
133 Q to P is added for each copy constraint of the form P = Q
135 6. The graph is then walked, and solution sets are
136 propagated along the copy edges, such that an edge from Q to P
137 causes Sol(P) <- Sol(P) union Sol(Q).
139 7. As we visit each node, all complex constraints associated with
140 that node are processed by adding appropriate copy edges to the graph, or the
141 appropriate variables to the solution set.
143 8. The process of walking the graph is iterated until no solution
146 Prior to walking the graph in steps 6 and 7, We perform static
147 cycle elimination on the constraint graph, as well
148 as off-line variable substitution.
150 TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
151 on and turned into anything), but isn't. You can just see what offset
152 inside the pointed-to struct it's going to access.
154 TODO: Constant bounded arrays can be handled as if they were structs of the
155 same number of elements.
157 TODO: Modeling heap and incoming pointers becomes much better if we
158 add fields to them as we discover them, which we could do.
160 TODO: We could handle unions, but to be honest, it's probably not
161 worth the pain or slowdown. */
163 /* IPA-PTA optimizations possible.
165 When the indirect function called is ANYTHING we can add disambiguation
166 based on the function signatures (or simply the parameter count which
167 is the varinfo size). We also do not need to consider functions that
168 do not have their address taken.
170 The is_global_var bit which marks escape points is overly conservative
171 in IPA mode. Split it to is_escape_point and is_global_var - only
172 externally visible globals are escape points in IPA mode. This is
173 also needed to fix the pt_solution_includes_global predicate
174 (and thus ptr_deref_may_alias_global_p).
176 The way we introduce DECL_PT_UID to avoid fixing up all points-to
177 sets in the translation unit when we copy a DECL during inlining
178 pessimizes precision. The advantage is that the DECL_PT_UID keeps
179 compile-time and memory usage overhead low - the points-to sets
180 do not grow or get unshared as they would during a fixup phase.
181 An alternative solution is to delay IPA PTA until after all
182 inlining transformations have been applied.
184 The way we propagate clobber/use information isn't optimized.
185 It should use a new complex constraint that properly filters
186 out local variables of the callee (though that would make
187 the sets invalid after inlining). OTOH we might as well
188 admit defeat to WHOPR and simply do all the clobber/use analysis
189 and propagation after PTA finished but before we threw away
190 points-to information for memory variables. WHOPR and PTA
191 do not play along well anyway - the whole constraint solving
192 would need to be done in WPA phase and it will be very interesting
193 to apply the results to local SSA names during LTRANS phase.
195 We probably should compute a per-function unit-ESCAPE solution
196 propagating it simply like the clobber / uses solutions. The
197 solution can go alongside the non-IPA espaced solution and be
198 used to query which vars escape the unit through a function.
200 We never put function decls in points-to sets so we do not
201 keep the set of called functions for indirect calls.
203 And probably more. */
205 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
206 htab_t heapvar_for_stmt;
208 static bool use_field_sensitive = true;
209 static int in_ipa_mode = 0;
211 /* Used for predecessor bitmaps. */
212 static bitmap_obstack predbitmap_obstack;
214 /* Used for points-to sets. */
215 static bitmap_obstack pta_obstack;
217 /* Used for oldsolution members of variables. */
218 static bitmap_obstack oldpta_obstack;
220 /* Used for per-solver-iteration bitmaps. */
221 static bitmap_obstack iteration_obstack;
223 static unsigned int create_variable_info_for (tree, const char *);
224 typedef struct constraint_graph *constraint_graph_t;
225 static void unify_nodes (constraint_graph_t, unsigned int, unsigned int, bool);
228 typedef struct constraint *constraint_t;
230 DEF_VEC_P(constraint_t);
231 DEF_VEC_ALLOC_P(constraint_t,heap);
233 #define EXECUTE_IF_IN_NONNULL_BITMAP(a, b, c, d) \
235 EXECUTE_IF_SET_IN_BITMAP (a, b, c, d)
237 static struct constraint_stats
239 unsigned int total_vars;
240 unsigned int nonpointer_vars;
241 unsigned int unified_vars_static;
242 unsigned int unified_vars_dynamic;
243 unsigned int iterations;
244 unsigned int num_edges;
245 unsigned int num_implicit_edges;
246 unsigned int points_to_sets_created;
251 /* ID of this variable */
254 /* True if this is a variable created by the constraint analysis, such as
255 heap variables and constraints we had to break up. */
256 unsigned int is_artificial_var : 1;
258 /* True if this is a special variable whose solution set should not be
260 unsigned int is_special_var : 1;
262 /* True for variables whose size is not known or variable. */
263 unsigned int is_unknown_size_var : 1;
265 /* True for (sub-)fields that represent a whole variable. */
266 unsigned int is_full_var : 1;
268 /* True if this is a heap variable. */
269 unsigned int is_heap_var : 1;
271 /* True if this is a variable tracking a restrict pointer source. */
272 unsigned int is_restrict_var : 1;
274 /* True if this field may contain pointers. */
275 unsigned int may_have_pointers : 1;
277 /* True if this field has only restrict qualified pointers. */
278 unsigned int only_restrict_pointers : 1;
280 /* True if this represents a global variable. */
281 unsigned int is_global_var : 1;
283 /* True if this represents a IPA function info. */
284 unsigned int is_fn_info : 1;
286 /* A link to the variable for the next field in this structure. */
287 struct variable_info *next;
289 /* Offset of this variable, in bits, from the base variable */
290 unsigned HOST_WIDE_INT offset;
292 /* Size of the variable, in bits. */
293 unsigned HOST_WIDE_INT size;
295 /* Full size of the base variable, in bits. */
296 unsigned HOST_WIDE_INT fullsize;
298 /* Name of this variable */
301 /* Tree that this variable is associated with. */
304 /* Points-to set for this variable. */
307 /* Old points-to set for this variable. */
310 typedef struct variable_info *varinfo_t;
312 static varinfo_t first_vi_for_offset (varinfo_t, unsigned HOST_WIDE_INT);
313 static varinfo_t first_or_preceding_vi_for_offset (varinfo_t,
314 unsigned HOST_WIDE_INT);
315 static varinfo_t lookup_vi_for_tree (tree);
317 /* Pool of variable info structures. */
318 static alloc_pool variable_info_pool;
320 DEF_VEC_P(varinfo_t);
322 DEF_VEC_ALLOC_P(varinfo_t, heap);
324 /* Table of variable info structures for constraint variables.
325 Indexed directly by variable info id. */
326 static VEC(varinfo_t,heap) *varmap;
328 /* Return the varmap element N */
330 static inline varinfo_t
331 get_varinfo (unsigned int n)
333 return VEC_index (varinfo_t, varmap, n);
336 /* Static IDs for the special variables. */
337 enum { nothing_id = 0, anything_id = 1, readonly_id = 2,
338 escaped_id = 3, nonlocal_id = 4,
339 storedanything_id = 5, integer_id = 6 };
341 struct GTY(()) heapvar_map {
343 unsigned HOST_WIDE_INT offset;
347 heapvar_map_eq (const void *p1, const void *p2)
349 const struct heapvar_map *h1 = (const struct heapvar_map *)p1;
350 const struct heapvar_map *h2 = (const struct heapvar_map *)p2;
351 return (h1->map.base.from == h2->map.base.from
352 && h1->offset == h2->offset);
356 heapvar_map_hash (struct heapvar_map *h)
358 return iterative_hash_host_wide_int (h->offset,
359 htab_hash_pointer (h->map.base.from));
362 /* Lookup a heap var for FROM, and return it if we find one. */
365 heapvar_lookup (tree from, unsigned HOST_WIDE_INT offset)
367 struct heapvar_map *h, in;
368 in.map.base.from = from;
370 h = (struct heapvar_map *) htab_find_with_hash (heapvar_for_stmt, &in,
371 heapvar_map_hash (&in));
377 /* Insert a mapping FROM->TO in the heap var for statement
381 heapvar_insert (tree from, unsigned HOST_WIDE_INT offset, tree to)
383 struct heapvar_map *h;
386 h = GGC_NEW (struct heapvar_map);
387 h->map.base.from = from;
389 h->map.hash = heapvar_map_hash (h);
391 loc = htab_find_slot_with_hash (heapvar_for_stmt, h, h->map.hash, INSERT);
392 gcc_assert (*loc == NULL);
393 *(struct heapvar_map **) loc = h;
396 /* Return a new variable info structure consisting for a variable
397 named NAME, and using constraint graph node NODE. Append it
398 to the vector of variable info structures. */
401 new_var_info (tree t, const char *name)
403 unsigned index = VEC_length (varinfo_t, varmap);
404 varinfo_t ret = (varinfo_t) pool_alloc (variable_info_pool);
409 /* Vars without decl are artificial and do not have sub-variables. */
410 ret->is_artificial_var = (t == NULL_TREE);
411 ret->is_special_var = false;
412 ret->is_unknown_size_var = false;
413 ret->is_full_var = (t == NULL_TREE);
414 ret->is_heap_var = false;
415 ret->is_restrict_var = false;
416 ret->may_have_pointers = true;
417 ret->only_restrict_pointers = false;
418 ret->is_global_var = (t == NULL_TREE);
419 ret->is_fn_info = false;
421 ret->is_global_var = is_global_var (t);
422 ret->solution = BITMAP_ALLOC (&pta_obstack);
423 ret->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
428 VEC_safe_push (varinfo_t, heap, varmap, ret);
434 /* A map mapping call statements to per-stmt variables for uses
435 and clobbers specific to the call. */
436 struct pointer_map_t *call_stmt_vars;
438 /* Lookup or create the variable for the call statement CALL. */
441 get_call_vi (gimple call)
446 slot_p = pointer_map_insert (call_stmt_vars, call);
448 return (varinfo_t) *slot_p;
450 vi = new_var_info (NULL_TREE, "CALLUSED");
454 vi->is_full_var = true;
456 vi->next = vi2 = new_var_info (NULL_TREE, "CALLCLOBBERED");
460 vi2->is_full_var = true;
462 *slot_p = (void *) vi;
466 /* Lookup the variable for the call statement CALL representing
467 the uses. Returns NULL if there is nothing special about this call. */
470 lookup_call_use_vi (gimple call)
474 slot_p = pointer_map_contains (call_stmt_vars, call);
476 return (varinfo_t) *slot_p;
481 /* Lookup the variable for the call statement CALL representing
482 the clobbers. Returns NULL if there is nothing special about this call. */
485 lookup_call_clobber_vi (gimple call)
487 varinfo_t uses = lookup_call_use_vi (call);
494 /* Lookup or create the variable for the call statement CALL representing
498 get_call_use_vi (gimple call)
500 return get_call_vi (call);
503 /* Lookup or create the variable for the call statement CALL representing
506 static varinfo_t ATTRIBUTE_UNUSED
507 get_call_clobber_vi (gimple call)
509 return get_call_vi (call)->next;
513 typedef enum {SCALAR, DEREF, ADDRESSOF} constraint_expr_type;
515 /* An expression that appears in a constraint. */
517 struct constraint_expr
519 /* Constraint type. */
520 constraint_expr_type type;
522 /* Variable we are referring to in the constraint. */
525 /* Offset, in bits, of this constraint from the beginning of
526 variables it ends up referring to.
528 IOW, in a deref constraint, we would deref, get the result set,
529 then add OFFSET to each member. */
530 HOST_WIDE_INT offset;
533 /* Use 0x8000... as special unknown offset. */
534 #define UNKNOWN_OFFSET ((HOST_WIDE_INT)-1 << (HOST_BITS_PER_WIDE_INT-1))
536 typedef struct constraint_expr ce_s;
538 DEF_VEC_ALLOC_O(ce_s, heap);
539 static void get_constraint_for_1 (tree, VEC(ce_s, heap) **, bool);
540 static void get_constraint_for (tree, VEC(ce_s, heap) **);
541 static void do_deref (VEC (ce_s, heap) **);
543 /* Our set constraints are made up of two constraint expressions, one
546 As described in the introduction, our set constraints each represent an
547 operation between set valued variables.
551 struct constraint_expr lhs;
552 struct constraint_expr rhs;
555 /* List of constraints that we use to build the constraint graph from. */
557 static VEC(constraint_t,heap) *constraints;
558 static alloc_pool constraint_pool;
560 /* The constraint graph is represented as an array of bitmaps
561 containing successor nodes. */
563 struct constraint_graph
565 /* Size of this graph, which may be different than the number of
566 nodes in the variable map. */
569 /* Explicit successors of each node. */
572 /* Implicit predecessors of each node (Used for variable
574 bitmap *implicit_preds;
576 /* Explicit predecessors of each node (Used for variable substitution). */
579 /* Indirect cycle representatives, or -1 if the node has no indirect
581 int *indirect_cycles;
583 /* Representative node for a node. rep[a] == a unless the node has
587 /* Equivalence class representative for a label. This is used for
588 variable substitution. */
591 /* Pointer equivalence label for a node. All nodes with the same
592 pointer equivalence label can be unified together at some point
593 (either during constraint optimization or after the constraint
597 /* Pointer equivalence representative for a label. This is used to
598 handle nodes that are pointer equivalent but not location
599 equivalent. We can unite these once the addressof constraints
600 are transformed into initial points-to sets. */
603 /* Pointer equivalence label for each node, used during variable
605 unsigned int *pointer_label;
607 /* Location equivalence label for each node, used during location
608 equivalence finding. */
609 unsigned int *loc_label;
611 /* Pointed-by set for each node, used during location equivalence
612 finding. This is pointed-by rather than pointed-to, because it
613 is constructed using the predecessor graph. */
616 /* Points to sets for pointer equivalence. This is *not* the actual
617 points-to sets for nodes. */
620 /* Bitmap of nodes where the bit is set if the node is a direct
621 node. Used for variable substitution. */
622 sbitmap direct_nodes;
624 /* Bitmap of nodes where the bit is set if the node is address
625 taken. Used for variable substitution. */
626 bitmap address_taken;
628 /* Vector of complex constraints for each graph node. Complex
629 constraints are those involving dereferences or offsets that are
631 VEC(constraint_t,heap) **complex;
634 static constraint_graph_t graph;
636 /* During variable substitution and the offline version of indirect
637 cycle finding, we create nodes to represent dereferences and
638 address taken constraints. These represent where these start and
640 #define FIRST_REF_NODE (VEC_length (varinfo_t, varmap))
641 #define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
643 /* Return the representative node for NODE, if NODE has been unioned
645 This function performs path compression along the way to finding
646 the representative. */
649 find (unsigned int node)
651 gcc_assert (node < graph->size);
652 if (graph->rep[node] != node)
653 return graph->rep[node] = find (graph->rep[node]);
657 /* Union the TO and FROM nodes to the TO nodes.
658 Note that at some point in the future, we may want to do
659 union-by-rank, in which case we are going to have to return the
660 node we unified to. */
663 unite (unsigned int to, unsigned int from)
665 gcc_assert (to < graph->size && from < graph->size);
666 if (to != from && graph->rep[from] != to)
668 graph->rep[from] = to;
674 /* Create a new constraint consisting of LHS and RHS expressions. */
677 new_constraint (const struct constraint_expr lhs,
678 const struct constraint_expr rhs)
680 constraint_t ret = (constraint_t) pool_alloc (constraint_pool);
686 /* Print out constraint C to FILE. */
689 dump_constraint (FILE *file, constraint_t c)
691 if (c->lhs.type == ADDRESSOF)
693 else if (c->lhs.type == DEREF)
695 fprintf (file, "%s", get_varinfo (c->lhs.var)->name);
696 if (c->lhs.offset == UNKNOWN_OFFSET)
697 fprintf (file, " + UNKNOWN");
698 else if (c->lhs.offset != 0)
699 fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->lhs.offset);
700 fprintf (file, " = ");
701 if (c->rhs.type == ADDRESSOF)
703 else if (c->rhs.type == DEREF)
705 fprintf (file, "%s", get_varinfo (c->rhs.var)->name);
706 if (c->rhs.offset == UNKNOWN_OFFSET)
707 fprintf (file, " + UNKNOWN");
708 else if (c->rhs.offset != 0)
709 fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->rhs.offset);
710 fprintf (file, "\n");
714 void debug_constraint (constraint_t);
715 void debug_constraints (void);
716 void debug_constraint_graph (void);
717 void debug_solution_for_var (unsigned int);
718 void debug_sa_points_to_info (void);
720 /* Print out constraint C to stderr. */
723 debug_constraint (constraint_t c)
725 dump_constraint (stderr, c);
728 /* Print out all constraints to FILE */
731 dump_constraints (FILE *file, int from)
735 for (i = from; VEC_iterate (constraint_t, constraints, i, c); i++)
736 dump_constraint (file, c);
739 /* Print out all constraints to stderr. */
742 debug_constraints (void)
744 dump_constraints (stderr, 0);
747 /* Print out to FILE the edge in the constraint graph that is created by
748 constraint c. The edge may have a label, depending on the type of
749 constraint that it represents. If complex1, e.g: a = *b, then the label
750 is "=*", if complex2, e.g: *a = b, then the label is "*=", if
751 complex with an offset, e.g: a = b + 8, then the label is "+".
752 Otherwise the edge has no label. */
755 dump_constraint_edge (FILE *file, constraint_t c)
757 if (c->rhs.type != ADDRESSOF)
759 const char *src = get_varinfo (c->rhs.var)->name;
760 const char *dst = get_varinfo (c->lhs.var)->name;
761 fprintf (file, " \"%s\" -> \"%s\" ", src, dst);
762 /* Due to preprocessing of constraints, instructions like *a = *b are
763 illegal; thus, we do not have to handle such cases. */
764 if (c->lhs.type == DEREF)
765 fprintf (file, " [ label=\"*=\" ] ;\n");
766 else if (c->rhs.type == DEREF)
767 fprintf (file, " [ label=\"=*\" ] ;\n");
770 /* We must check the case where the constraint is an offset.
771 In this case, it is treated as a complex constraint. */
772 if (c->rhs.offset != c->lhs.offset)
773 fprintf (file, " [ label=\"+\" ] ;\n");
775 fprintf (file, " ;\n");
780 /* Print the constraint graph in dot format. */
783 dump_constraint_graph (FILE *file)
785 unsigned int i=0, size;
788 /* Only print the graph if it has already been initialized: */
792 /* Print the constraints used to produce the constraint graph. The
793 constraints will be printed as comments in the dot file: */
794 fprintf (file, "\n\n/* Constraints used in the constraint graph:\n");
795 dump_constraints (file, 0);
796 fprintf (file, "*/\n");
798 /* Prints the header of the dot file: */
799 fprintf (file, "\n\n// The constraint graph in dot format:\n");
800 fprintf (file, "strict digraph {\n");
801 fprintf (file, " node [\n shape = box\n ]\n");
802 fprintf (file, " edge [\n fontsize = \"12\"\n ]\n");
803 fprintf (file, "\n // List of nodes in the constraint graph:\n");
805 /* The next lines print the nodes in the graph. In order to get the
806 number of nodes in the graph, we must choose the minimum between the
807 vector VEC (varinfo_t, varmap) and graph->size. If the graph has not
808 yet been initialized, then graph->size == 0, otherwise we must only
809 read nodes that have an entry in VEC (varinfo_t, varmap). */
810 size = VEC_length (varinfo_t, varmap);
811 size = size < graph->size ? size : graph->size;
812 for (i = 0; i < size; i++)
814 const char *name = get_varinfo (graph->rep[i])->name;
815 fprintf (file, " \"%s\" ;\n", name);
818 /* Go over the list of constraints printing the edges in the constraint
820 fprintf (file, "\n // The constraint edges:\n");
821 for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
823 dump_constraint_edge (file, c);
825 /* Prints the tail of the dot file. By now, only the closing bracket. */
826 fprintf (file, "}\n\n\n");
829 /* Print out the constraint graph to stderr. */
832 debug_constraint_graph (void)
834 dump_constraint_graph (stderr);
839 The solver is a simple worklist solver, that works on the following
842 sbitmap changed_nodes = all zeroes;
844 For each node that is not already collapsed:
846 set bit in changed nodes
848 while (changed_count > 0)
850 compute topological ordering for constraint graph
852 find and collapse cycles in the constraint graph (updating
853 changed if necessary)
855 for each node (n) in the graph in topological order:
858 Process each complex constraint associated with the node,
859 updating changed if necessary.
861 For each outgoing edge from n, propagate the solution from n to
862 the destination of the edge, updating changed as necessary.
866 /* Return true if two constraint expressions A and B are equal. */
869 constraint_expr_equal (struct constraint_expr a, struct constraint_expr b)
871 return a.type == b.type && a.var == b.var && a.offset == b.offset;
874 /* Return true if constraint expression A is less than constraint expression
875 B. This is just arbitrary, but consistent, in order to give them an
879 constraint_expr_less (struct constraint_expr a, struct constraint_expr b)
881 if (a.type == b.type)
884 return a.offset < b.offset;
886 return a.var < b.var;
889 return a.type < b.type;
892 /* Return true if constraint A is less than constraint B. This is just
893 arbitrary, but consistent, in order to give them an ordering. */
896 constraint_less (const constraint_t a, const constraint_t b)
898 if (constraint_expr_less (a->lhs, b->lhs))
900 else if (constraint_expr_less (b->lhs, a->lhs))
903 return constraint_expr_less (a->rhs, b->rhs);
906 /* Return true if two constraints A and B are equal. */
909 constraint_equal (struct constraint a, struct constraint b)
911 return constraint_expr_equal (a.lhs, b.lhs)
912 && constraint_expr_equal (a.rhs, b.rhs);
916 /* Find a constraint LOOKFOR in the sorted constraint vector VEC */
919 constraint_vec_find (VEC(constraint_t,heap) *vec,
920 struct constraint lookfor)
928 place = VEC_lower_bound (constraint_t, vec, &lookfor, constraint_less);
929 if (place >= VEC_length (constraint_t, vec))
931 found = VEC_index (constraint_t, vec, place);
932 if (!constraint_equal (*found, lookfor))
937 /* Union two constraint vectors, TO and FROM. Put the result in TO. */
940 constraint_set_union (VEC(constraint_t,heap) **to,
941 VEC(constraint_t,heap) **from)
946 for (i = 0; VEC_iterate (constraint_t, *from, i, c); i++)
948 if (constraint_vec_find (*to, *c) == NULL)
950 unsigned int place = VEC_lower_bound (constraint_t, *to, c,
952 VEC_safe_insert (constraint_t, heap, *to, place, c);
957 /* Expands the solution in SET to all sub-fields of variables included.
958 Union the expanded result into RESULT. */
961 solution_set_expand (bitmap result, bitmap set)
967 /* In a first pass record all variables we need to add all
968 sub-fields off. This avoids quadratic behavior. */
969 EXECUTE_IF_SET_IN_BITMAP (set, 0, j, bi)
971 varinfo_t v = get_varinfo (j);
972 if (v->is_artificial_var
975 v = lookup_vi_for_tree (v->decl);
977 vars = BITMAP_ALLOC (NULL);
978 bitmap_set_bit (vars, v->id);
981 /* In the second pass now do the addition to the solution and
982 to speed up solving add it to the delta as well. */
985 EXECUTE_IF_SET_IN_BITMAP (vars, 0, j, bi)
987 varinfo_t v = get_varinfo (j);
988 for (; v != NULL; v = v->next)
989 bitmap_set_bit (result, v->id);
995 /* Take a solution set SET, add OFFSET to each member of the set, and
996 overwrite SET with the result when done. */
999 solution_set_add (bitmap set, HOST_WIDE_INT offset)
1001 bitmap result = BITMAP_ALLOC (&iteration_obstack);
1005 /* If the offset is unknown we have to expand the solution to
1007 if (offset == UNKNOWN_OFFSET)
1009 solution_set_expand (set, set);
1013 EXECUTE_IF_SET_IN_BITMAP (set, 0, i, bi)
1015 varinfo_t vi = get_varinfo (i);
1017 /* If this is a variable with just one field just set its bit
1019 if (vi->is_artificial_var
1020 || vi->is_unknown_size_var
1022 bitmap_set_bit (result, i);
1025 unsigned HOST_WIDE_INT fieldoffset = vi->offset + offset;
1027 /* If the offset makes the pointer point to before the
1028 variable use offset zero for the field lookup. */
1030 && fieldoffset > vi->offset)
1034 vi = first_or_preceding_vi_for_offset (vi, fieldoffset);
1036 bitmap_set_bit (result, vi->id);
1037 /* If the result is not exactly at fieldoffset include the next
1038 field as well. See get_constraint_for_ptr_offset for more
1040 if (vi->offset != fieldoffset
1041 && vi->next != NULL)
1042 bitmap_set_bit (result, vi->next->id);
1046 bitmap_copy (set, result);
1047 BITMAP_FREE (result);
1050 /* Union solution sets TO and FROM, and add INC to each member of FROM in the
1054 set_union_with_increment (bitmap to, bitmap from, HOST_WIDE_INT inc)
1057 return bitmap_ior_into (to, from);
1063 tmp = BITMAP_ALLOC (&iteration_obstack);
1064 bitmap_copy (tmp, from);
1065 solution_set_add (tmp, inc);
1066 res = bitmap_ior_into (to, tmp);
1072 /* Insert constraint C into the list of complex constraints for graph
1076 insert_into_complex (constraint_graph_t graph,
1077 unsigned int var, constraint_t c)
1079 VEC (constraint_t, heap) *complex = graph->complex[var];
1080 unsigned int place = VEC_lower_bound (constraint_t, complex, c,
1083 /* Only insert constraints that do not already exist. */
1084 if (place >= VEC_length (constraint_t, complex)
1085 || !constraint_equal (*c, *VEC_index (constraint_t, complex, place)))
1086 VEC_safe_insert (constraint_t, heap, graph->complex[var], place, c);
1090 /* Condense two variable nodes into a single variable node, by moving
1091 all associated info from SRC to TO. */
1094 merge_node_constraints (constraint_graph_t graph, unsigned int to,
1100 gcc_assert (find (from) == to);
1102 /* Move all complex constraints from src node into to node */
1103 for (i = 0; VEC_iterate (constraint_t, graph->complex[from], i, c); i++)
1105 /* In complex constraints for node src, we may have either
1106 a = *src, and *src = a, or an offseted constraint which are
1107 always added to the rhs node's constraints. */
1109 if (c->rhs.type == DEREF)
1111 else if (c->lhs.type == DEREF)
1116 constraint_set_union (&graph->complex[to], &graph->complex[from]);
1117 VEC_free (constraint_t, heap, graph->complex[from]);
1118 graph->complex[from] = NULL;
1122 /* Remove edges involving NODE from GRAPH. */
1125 clear_edges_for_node (constraint_graph_t graph, unsigned int node)
1127 if (graph->succs[node])
1128 BITMAP_FREE (graph->succs[node]);
1131 /* Merge GRAPH nodes FROM and TO into node TO. */
1134 merge_graph_nodes (constraint_graph_t graph, unsigned int to,
1137 if (graph->indirect_cycles[from] != -1)
1139 /* If we have indirect cycles with the from node, and we have
1140 none on the to node, the to node has indirect cycles from the
1141 from node now that they are unified.
1142 If indirect cycles exist on both, unify the nodes that they
1143 are in a cycle with, since we know they are in a cycle with
1145 if (graph->indirect_cycles[to] == -1)
1146 graph->indirect_cycles[to] = graph->indirect_cycles[from];
1149 /* Merge all the successor edges. */
1150 if (graph->succs[from])
1152 if (!graph->succs[to])
1153 graph->succs[to] = BITMAP_ALLOC (&pta_obstack);
1154 bitmap_ior_into (graph->succs[to],
1155 graph->succs[from]);
1158 clear_edges_for_node (graph, from);
1162 /* Add an indirect graph edge to GRAPH, going from TO to FROM if
1163 it doesn't exist in the graph already. */
1166 add_implicit_graph_edge (constraint_graph_t graph, unsigned int to,
1172 if (!graph->implicit_preds[to])
1173 graph->implicit_preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
1175 if (bitmap_set_bit (graph->implicit_preds[to], from))
1176 stats.num_implicit_edges++;
1179 /* Add a predecessor graph edge to GRAPH, going from TO to FROM if
1180 it doesn't exist in the graph already.
1181 Return false if the edge already existed, true otherwise. */
1184 add_pred_graph_edge (constraint_graph_t graph, unsigned int to,
1187 if (!graph->preds[to])
1188 graph->preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
1189 bitmap_set_bit (graph->preds[to], from);
1192 /* Add a graph edge to GRAPH, going from FROM to TO if
1193 it doesn't exist in the graph already.
1194 Return false if the edge already existed, true otherwise. */
1197 add_graph_edge (constraint_graph_t graph, unsigned int to,
1208 if (!graph->succs[from])
1209 graph->succs[from] = BITMAP_ALLOC (&pta_obstack);
1210 if (bitmap_set_bit (graph->succs[from], to))
1213 if (to < FIRST_REF_NODE && from < FIRST_REF_NODE)
1221 /* Return true if {DEST.SRC} is an existing graph edge in GRAPH. */
1224 valid_graph_edge (constraint_graph_t graph, unsigned int src,
1227 return (graph->succs[dest]
1228 && bitmap_bit_p (graph->succs[dest], src));
1231 /* Initialize the constraint graph structure to contain SIZE nodes. */
1234 init_graph (unsigned int size)
1238 graph = XCNEW (struct constraint_graph);
1240 graph->succs = XCNEWVEC (bitmap, graph->size);
1241 graph->indirect_cycles = XNEWVEC (int, graph->size);
1242 graph->rep = XNEWVEC (unsigned int, graph->size);
1243 graph->complex = XCNEWVEC (VEC(constraint_t, heap) *, size);
1244 graph->pe = XCNEWVEC (unsigned int, graph->size);
1245 graph->pe_rep = XNEWVEC (int, graph->size);
1247 for (j = 0; j < graph->size; j++)
1250 graph->pe_rep[j] = -1;
1251 graph->indirect_cycles[j] = -1;
1255 /* Build the constraint graph, adding only predecessor edges right now. */
1258 build_pred_graph (void)
1264 graph->implicit_preds = XCNEWVEC (bitmap, graph->size);
1265 graph->preds = XCNEWVEC (bitmap, graph->size);
1266 graph->pointer_label = XCNEWVEC (unsigned int, graph->size);
1267 graph->loc_label = XCNEWVEC (unsigned int, graph->size);
1268 graph->pointed_by = XCNEWVEC (bitmap, graph->size);
1269 graph->points_to = XCNEWVEC (bitmap, graph->size);
1270 graph->eq_rep = XNEWVEC (int, graph->size);
1271 graph->direct_nodes = sbitmap_alloc (graph->size);
1272 graph->address_taken = BITMAP_ALLOC (&predbitmap_obstack);
1273 sbitmap_zero (graph->direct_nodes);
1275 for (j = 0; j < FIRST_REF_NODE; j++)
1277 if (!get_varinfo (j)->is_special_var)
1278 SET_BIT (graph->direct_nodes, j);
1281 for (j = 0; j < graph->size; j++)
1282 graph->eq_rep[j] = -1;
1284 for (j = 0; j < VEC_length (varinfo_t, varmap); j++)
1285 graph->indirect_cycles[j] = -1;
1287 for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
1289 struct constraint_expr lhs = c->lhs;
1290 struct constraint_expr rhs = c->rhs;
1291 unsigned int lhsvar = lhs.var;
1292 unsigned int rhsvar = rhs.var;
1294 if (lhs.type == DEREF)
1297 if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
1298 add_pred_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
1300 else if (rhs.type == DEREF)
1303 if (rhs.offset == 0 && lhs.offset == 0 && lhs.type == SCALAR)
1304 add_pred_graph_edge (graph, lhsvar, FIRST_REF_NODE + rhsvar);
1306 RESET_BIT (graph->direct_nodes, lhsvar);
1308 else if (rhs.type == ADDRESSOF)
1313 if (graph->points_to[lhsvar] == NULL)
1314 graph->points_to[lhsvar] = BITMAP_ALLOC (&predbitmap_obstack);
1315 bitmap_set_bit (graph->points_to[lhsvar], rhsvar);
1317 if (graph->pointed_by[rhsvar] == NULL)
1318 graph->pointed_by[rhsvar] = BITMAP_ALLOC (&predbitmap_obstack);
1319 bitmap_set_bit (graph->pointed_by[rhsvar], lhsvar);
1321 /* Implicitly, *x = y */
1322 add_implicit_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
1324 /* All related variables are no longer direct nodes. */
1325 RESET_BIT (graph->direct_nodes, rhsvar);
1326 v = get_varinfo (rhsvar);
1327 if (!v->is_full_var)
1329 v = lookup_vi_for_tree (v->decl);
1332 RESET_BIT (graph->direct_nodes, v->id);
1337 bitmap_set_bit (graph->address_taken, rhsvar);
1339 else if (lhsvar > anything_id
1340 && lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
1343 add_pred_graph_edge (graph, lhsvar, rhsvar);
1344 /* Implicitly, *x = *y */
1345 add_implicit_graph_edge (graph, FIRST_REF_NODE + lhsvar,
1346 FIRST_REF_NODE + rhsvar);
1348 else if (lhs.offset != 0 || rhs.offset != 0)
1350 if (rhs.offset != 0)
1351 RESET_BIT (graph->direct_nodes, lhs.var);
1352 else if (lhs.offset != 0)
1353 RESET_BIT (graph->direct_nodes, rhs.var);
1358 /* Build the constraint graph, adding successor edges. */
1361 build_succ_graph (void)
1366 for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
1368 struct constraint_expr lhs;
1369 struct constraint_expr rhs;
1370 unsigned int lhsvar;
1371 unsigned int rhsvar;
1378 lhsvar = find (lhs.var);
1379 rhsvar = find (rhs.var);
1381 if (lhs.type == DEREF)
1383 if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
1384 add_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
1386 else if (rhs.type == DEREF)
1388 if (rhs.offset == 0 && lhs.offset == 0 && lhs.type == SCALAR)
1389 add_graph_edge (graph, lhsvar, FIRST_REF_NODE + rhsvar);
1391 else if (rhs.type == ADDRESSOF)
1394 gcc_assert (find (rhs.var) == rhs.var);
1395 bitmap_set_bit (get_varinfo (lhsvar)->solution, rhsvar);
1397 else if (lhsvar > anything_id
1398 && lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
1400 add_graph_edge (graph, lhsvar, rhsvar);
1404 /* Add edges from STOREDANYTHING to all non-direct nodes that can
1405 receive pointers. */
1406 t = find (storedanything_id);
1407 for (i = integer_id + 1; i < FIRST_REF_NODE; ++i)
1409 if (!TEST_BIT (graph->direct_nodes, i)
1410 && get_varinfo (i)->may_have_pointers)
1411 add_graph_edge (graph, find (i), t);
1414 /* Everything stored to ANYTHING also potentially escapes. */
1415 add_graph_edge (graph, find (escaped_id), t);
1419 /* Changed variables on the last iteration. */
1420 static unsigned int changed_count;
1421 static sbitmap changed;
1423 /* Strongly Connected Component visitation info. */
1430 unsigned int *node_mapping;
1432 VEC(unsigned,heap) *scc_stack;
1436 /* Recursive routine to find strongly connected components in GRAPH.
1437 SI is the SCC info to store the information in, and N is the id of current
1438 graph node we are processing.
1440 This is Tarjan's strongly connected component finding algorithm, as
1441 modified by Nuutila to keep only non-root nodes on the stack.
1442 The algorithm can be found in "On finding the strongly connected
1443 connected components in a directed graph" by Esko Nuutila and Eljas
1444 Soisalon-Soininen, in Information Processing Letters volume 49,
1445 number 1, pages 9-14. */
1448 scc_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
1452 unsigned int my_dfs;
1454 SET_BIT (si->visited, n);
1455 si->dfs[n] = si->current_index ++;
1456 my_dfs = si->dfs[n];
1458 /* Visit all the successors. */
1459 EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[n], 0, i, bi)
1463 if (i > LAST_REF_NODE)
1467 if (TEST_BIT (si->deleted, w))
1470 if (!TEST_BIT (si->visited, w))
1471 scc_visit (graph, si, w);
1473 unsigned int t = find (w);
1474 unsigned int nnode = find (n);
1475 gcc_assert (nnode == n);
1477 if (si->dfs[t] < si->dfs[nnode])
1478 si->dfs[n] = si->dfs[t];
1482 /* See if any components have been identified. */
1483 if (si->dfs[n] == my_dfs)
1485 if (VEC_length (unsigned, si->scc_stack) > 0
1486 && si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
1488 bitmap scc = BITMAP_ALLOC (NULL);
1489 unsigned int lowest_node;
1492 bitmap_set_bit (scc, n);
1494 while (VEC_length (unsigned, si->scc_stack) != 0
1495 && si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
1497 unsigned int w = VEC_pop (unsigned, si->scc_stack);
1499 bitmap_set_bit (scc, w);
1502 lowest_node = bitmap_first_set_bit (scc);
1503 gcc_assert (lowest_node < FIRST_REF_NODE);
1505 /* Collapse the SCC nodes into a single node, and mark the
1507 EXECUTE_IF_SET_IN_BITMAP (scc, 0, i, bi)
1509 if (i < FIRST_REF_NODE)
1511 if (unite (lowest_node, i))
1512 unify_nodes (graph, lowest_node, i, false);
1516 unite (lowest_node, i);
1517 graph->indirect_cycles[i - FIRST_REF_NODE] = lowest_node;
1521 SET_BIT (si->deleted, n);
1524 VEC_safe_push (unsigned, heap, si->scc_stack, n);
1527 /* Unify node FROM into node TO, updating the changed count if
1528 necessary when UPDATE_CHANGED is true. */
1531 unify_nodes (constraint_graph_t graph, unsigned int to, unsigned int from,
1532 bool update_changed)
1535 gcc_assert (to != from && find (to) == to);
1536 if (dump_file && (dump_flags & TDF_DETAILS))
1537 fprintf (dump_file, "Unifying %s to %s\n",
1538 get_varinfo (from)->name,
1539 get_varinfo (to)->name);
1542 stats.unified_vars_dynamic++;
1544 stats.unified_vars_static++;
1546 merge_graph_nodes (graph, to, from);
1547 merge_node_constraints (graph, to, from);
1549 /* Mark TO as changed if FROM was changed. If TO was already marked
1550 as changed, decrease the changed count. */
1552 if (update_changed && TEST_BIT (changed, from))
1554 RESET_BIT (changed, from);
1555 if (!TEST_BIT (changed, to))
1556 SET_BIT (changed, to);
1559 gcc_assert (changed_count > 0);
1563 if (get_varinfo (from)->solution)
1565 /* If the solution changes because of the merging, we need to mark
1566 the variable as changed. */
1567 if (bitmap_ior_into (get_varinfo (to)->solution,
1568 get_varinfo (from)->solution))
1570 if (update_changed && !TEST_BIT (changed, to))
1572 SET_BIT (changed, to);
1577 BITMAP_FREE (get_varinfo (from)->solution);
1578 BITMAP_FREE (get_varinfo (from)->oldsolution);
1580 if (stats.iterations > 0)
1582 BITMAP_FREE (get_varinfo (to)->oldsolution);
1583 get_varinfo (to)->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
1586 if (valid_graph_edge (graph, to, to))
1588 if (graph->succs[to])
1589 bitmap_clear_bit (graph->succs[to], to);
1593 /* Information needed to compute the topological ordering of a graph. */
1597 /* sbitmap of visited nodes. */
1599 /* Array that stores the topological order of the graph, *in
1601 VEC(unsigned,heap) *topo_order;
1605 /* Initialize and return a topological info structure. */
1607 static struct topo_info *
1608 init_topo_info (void)
1610 size_t size = graph->size;
1611 struct topo_info *ti = XNEW (struct topo_info);
1612 ti->visited = sbitmap_alloc (size);
1613 sbitmap_zero (ti->visited);
1614 ti->topo_order = VEC_alloc (unsigned, heap, 1);
1619 /* Free the topological sort info pointed to by TI. */
1622 free_topo_info (struct topo_info *ti)
1624 sbitmap_free (ti->visited);
1625 VEC_free (unsigned, heap, ti->topo_order);
1629 /* Visit the graph in topological order, and store the order in the
1630 topo_info structure. */
1633 topo_visit (constraint_graph_t graph, struct topo_info *ti,
1639 SET_BIT (ti->visited, n);
1641 if (graph->succs[n])
1642 EXECUTE_IF_SET_IN_BITMAP (graph->succs[n], 0, j, bi)
1644 if (!TEST_BIT (ti->visited, j))
1645 topo_visit (graph, ti, j);
1648 VEC_safe_push (unsigned, heap, ti->topo_order, n);
1651 /* Process a constraint C that represents x = *(y + off), using DELTA as the
1652 starting solution for y. */
1655 do_sd_constraint (constraint_graph_t graph, constraint_t c,
1658 unsigned int lhs = c->lhs.var;
1660 bitmap sol = get_varinfo (lhs)->solution;
1663 HOST_WIDE_INT roffset = c->rhs.offset;
1665 /* Our IL does not allow this. */
1666 gcc_assert (c->lhs.offset == 0);
1668 /* If the solution of Y contains anything it is good enough to transfer
1670 if (bitmap_bit_p (delta, anything_id))
1672 flag |= bitmap_set_bit (sol, anything_id);
1676 /* If we do not know at with offset the rhs is dereferenced compute
1677 the reachability set of DELTA, conservatively assuming it is
1678 dereferenced at all valid offsets. */
1679 if (roffset == UNKNOWN_OFFSET)
1681 solution_set_expand (delta, delta);
1682 /* No further offset processing is necessary. */
1686 /* For each variable j in delta (Sol(y)), add
1687 an edge in the graph from j to x, and union Sol(j) into Sol(x). */
1688 EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
1690 varinfo_t v = get_varinfo (j);
1691 HOST_WIDE_INT fieldoffset = v->offset + roffset;
1695 fieldoffset = v->offset;
1696 else if (roffset != 0)
1697 v = first_vi_for_offset (v, fieldoffset);
1698 /* If the access is outside of the variable we can ignore it. */
1706 /* Adding edges from the special vars is pointless.
1707 They don't have sets that can change. */
1708 if (get_varinfo (t)->is_special_var)
1709 flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
1710 /* Merging the solution from ESCAPED needlessly increases
1711 the set. Use ESCAPED as representative instead. */
1712 else if (v->id == escaped_id)
1713 flag |= bitmap_set_bit (sol, escaped_id);
1714 else if (v->may_have_pointers
1715 && add_graph_edge (graph, lhs, t))
1716 flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
1718 /* If the variable is not exactly at the requested offset
1719 we have to include the next one. */
1720 if (v->offset == (unsigned HOST_WIDE_INT)fieldoffset
1725 fieldoffset = v->offset;
1731 /* If the LHS solution changed, mark the var as changed. */
1734 get_varinfo (lhs)->solution = sol;
1735 if (!TEST_BIT (changed, lhs))
1737 SET_BIT (changed, lhs);
1743 /* Process a constraint C that represents *(x + off) = y using DELTA
1744 as the starting solution for x. */
1747 do_ds_constraint (constraint_t c, bitmap delta)
1749 unsigned int rhs = c->rhs.var;
1750 bitmap sol = get_varinfo (rhs)->solution;
1753 HOST_WIDE_INT loff = c->lhs.offset;
1754 bool escaped_p = false;
1756 /* Our IL does not allow this. */
1757 gcc_assert (c->rhs.offset == 0);
1759 /* If the solution of y contains ANYTHING simply use the ANYTHING
1760 solution. This avoids needlessly increasing the points-to sets. */
1761 if (bitmap_bit_p (sol, anything_id))
1762 sol = get_varinfo (find (anything_id))->solution;
1764 /* If the solution for x contains ANYTHING we have to merge the
1765 solution of y into all pointer variables which we do via
1767 if (bitmap_bit_p (delta, anything_id))
1769 unsigned t = find (storedanything_id);
1770 if (add_graph_edge (graph, t, rhs))
1772 if (bitmap_ior_into (get_varinfo (t)->solution, sol))
1774 if (!TEST_BIT (changed, t))
1776 SET_BIT (changed, t);
1784 /* If we do not know at with offset the rhs is dereferenced compute
1785 the reachability set of DELTA, conservatively assuming it is
1786 dereferenced at all valid offsets. */
1787 if (loff == UNKNOWN_OFFSET)
1789 solution_set_expand (delta, delta);
1793 /* For each member j of delta (Sol(x)), add an edge from y to j and
1794 union Sol(y) into Sol(j) */
1795 EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
1797 varinfo_t v = get_varinfo (j);
1799 HOST_WIDE_INT fieldoffset = v->offset + loff;
1802 fieldoffset = v->offset;
1804 v = first_vi_for_offset (v, fieldoffset);
1805 /* If the access is outside of the variable we can ignore it. */
1811 if (v->may_have_pointers)
1813 /* If v is a global variable then this is an escape point. */
1814 if (v->is_global_var
1817 t = find (escaped_id);
1818 if (add_graph_edge (graph, t, rhs)
1819 && bitmap_ior_into (get_varinfo (t)->solution, sol)
1820 && !TEST_BIT (changed, t))
1822 SET_BIT (changed, t);
1825 /* Enough to let rhs escape once. */
1829 if (v->is_special_var)
1833 if (add_graph_edge (graph, t, rhs)
1834 && bitmap_ior_into (get_varinfo (t)->solution, sol)
1835 && !TEST_BIT (changed, t))
1837 SET_BIT (changed, t);
1842 /* If the variable is not exactly at the requested offset
1843 we have to include the next one. */
1844 if (v->offset == (unsigned HOST_WIDE_INT)fieldoffset
1849 fieldoffset = v->offset;
1855 /* Handle a non-simple (simple meaning requires no iteration),
1856 constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
1859 do_complex_constraint (constraint_graph_t graph, constraint_t c, bitmap delta)
1861 if (c->lhs.type == DEREF)
1863 if (c->rhs.type == ADDRESSOF)
1870 do_ds_constraint (c, delta);
1873 else if (c->rhs.type == DEREF)
1876 if (!(get_varinfo (c->lhs.var)->is_special_var))
1877 do_sd_constraint (graph, c, delta);
1885 gcc_assert (c->rhs.type == SCALAR && c->lhs.type == SCALAR);
1886 solution = get_varinfo (c->rhs.var)->solution;
1887 tmp = get_varinfo (c->lhs.var)->solution;
1889 flag = set_union_with_increment (tmp, solution, c->rhs.offset);
1893 get_varinfo (c->lhs.var)->solution = tmp;
1894 if (!TEST_BIT (changed, c->lhs.var))
1896 SET_BIT (changed, c->lhs.var);
1903 /* Initialize and return a new SCC info structure. */
1905 static struct scc_info *
1906 init_scc_info (size_t size)
1908 struct scc_info *si = XNEW (struct scc_info);
1911 si->current_index = 0;
1912 si->visited = sbitmap_alloc (size);
1913 sbitmap_zero (si->visited);
1914 si->deleted = sbitmap_alloc (size);
1915 sbitmap_zero (si->deleted);
1916 si->node_mapping = XNEWVEC (unsigned int, size);
1917 si->dfs = XCNEWVEC (unsigned int, size);
1919 for (i = 0; i < size; i++)
1920 si->node_mapping[i] = i;
1922 si->scc_stack = VEC_alloc (unsigned, heap, 1);
1926 /* Free an SCC info structure pointed to by SI */
1929 free_scc_info (struct scc_info *si)
1931 sbitmap_free (si->visited);
1932 sbitmap_free (si->deleted);
1933 free (si->node_mapping);
1935 VEC_free (unsigned, heap, si->scc_stack);
1940 /* Find indirect cycles in GRAPH that occur, using strongly connected
1941 components, and note them in the indirect cycles map.
1943 This technique comes from Ben Hardekopf and Calvin Lin,
1944 "It Pays to be Lazy: Fast and Accurate Pointer Analysis for Millions of
1945 Lines of Code", submitted to PLDI 2007. */
1948 find_indirect_cycles (constraint_graph_t graph)
1951 unsigned int size = graph->size;
1952 struct scc_info *si = init_scc_info (size);
1954 for (i = 0; i < MIN (LAST_REF_NODE, size); i ++ )
1955 if (!TEST_BIT (si->visited, i) && find (i) == i)
1956 scc_visit (graph, si, i);
1961 /* Compute a topological ordering for GRAPH, and store the result in the
1962 topo_info structure TI. */
1965 compute_topo_order (constraint_graph_t graph,
1966 struct topo_info *ti)
1969 unsigned int size = graph->size;
1971 for (i = 0; i != size; ++i)
1972 if (!TEST_BIT (ti->visited, i) && find (i) == i)
1973 topo_visit (graph, ti, i);
1976 /* Structure used to for hash value numbering of pointer equivalence
1979 typedef struct equiv_class_label
1982 unsigned int equivalence_class;
1984 } *equiv_class_label_t;
1985 typedef const struct equiv_class_label *const_equiv_class_label_t;
1987 /* A hashtable for mapping a bitmap of labels->pointer equivalence
1989 static htab_t pointer_equiv_class_table;
1991 /* A hashtable for mapping a bitmap of labels->location equivalence
1993 static htab_t location_equiv_class_table;
1995 /* Hash function for a equiv_class_label_t */
1998 equiv_class_label_hash (const void *p)
2000 const_equiv_class_label_t const ecl = (const_equiv_class_label_t) p;
2001 return ecl->hashcode;
2004 /* Equality function for two equiv_class_label_t's. */
2007 equiv_class_label_eq (const void *p1, const void *p2)
2009 const_equiv_class_label_t const eql1 = (const_equiv_class_label_t) p1;
2010 const_equiv_class_label_t const eql2 = (const_equiv_class_label_t) p2;
2011 return (eql1->hashcode == eql2->hashcode
2012 && bitmap_equal_p (eql1->labels, eql2->labels));
2015 /* Lookup a equivalence class in TABLE by the bitmap of LABELS it
2019 equiv_class_lookup (htab_t table, bitmap labels)
2022 struct equiv_class_label ecl;
2024 ecl.labels = labels;
2025 ecl.hashcode = bitmap_hash (labels);
2027 slot = htab_find_slot_with_hash (table, &ecl,
2028 ecl.hashcode, NO_INSERT);
2032 return ((equiv_class_label_t) *slot)->equivalence_class;
2036 /* Add an equivalence class named EQUIVALENCE_CLASS with labels LABELS
2040 equiv_class_add (htab_t table, unsigned int equivalence_class,
2044 equiv_class_label_t ecl = XNEW (struct equiv_class_label);
2046 ecl->labels = labels;
2047 ecl->equivalence_class = equivalence_class;
2048 ecl->hashcode = bitmap_hash (labels);
2050 slot = htab_find_slot_with_hash (table, ecl,
2051 ecl->hashcode, INSERT);
2052 gcc_assert (!*slot);
2053 *slot = (void *) ecl;
2056 /* Perform offline variable substitution.
2058 This is a worst case quadratic time way of identifying variables
2059 that must have equivalent points-to sets, including those caused by
2060 static cycles, and single entry subgraphs, in the constraint graph.
2062 The technique is described in "Exploiting Pointer and Location
2063 Equivalence to Optimize Pointer Analysis. In the 14th International
2064 Static Analysis Symposium (SAS), August 2007." It is known as the
2065 "HU" algorithm, and is equivalent to value numbering the collapsed
2066 constraint graph including evaluating unions.
2068 The general method of finding equivalence classes is as follows:
2069 Add fake nodes (REF nodes) and edges for *a = b and a = *b constraints.
2070 Initialize all non-REF nodes to be direct nodes.
2071 For each constraint a = a U {b}, we set pts(a) = pts(a) u {fresh
2073 For each constraint containing the dereference, we also do the same
2076 We then compute SCC's in the graph and unify nodes in the same SCC,
2079 For each non-collapsed node x:
2080 Visit all unvisited explicit incoming edges.
2081 Ignoring all non-pointers, set pts(x) = Union of pts(a) for y
2083 Lookup the equivalence class for pts(x).
2084 If we found one, equivalence_class(x) = found class.
2085 Otherwise, equivalence_class(x) = new class, and new_class is
2086 added to the lookup table.
2088 All direct nodes with the same equivalence class can be replaced
2089 with a single representative node.
2090 All unlabeled nodes (label == 0) are not pointers and all edges
2091 involving them can be eliminated.
2092 We perform these optimizations during rewrite_constraints
2094 In addition to pointer equivalence class finding, we also perform
2095 location equivalence class finding. This is the set of variables
2096 that always appear together in points-to sets. We use this to
2097 compress the size of the points-to sets. */
2099 /* Current maximum pointer equivalence class id. */
2100 static int pointer_equiv_class;
2102 /* Current maximum location equivalence class id. */
2103 static int location_equiv_class;
2105 /* Recursive routine to find strongly connected components in GRAPH,
2106 and label it's nodes with DFS numbers. */
2109 condense_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
2113 unsigned int my_dfs;
2115 gcc_assert (si->node_mapping[n] == n);
2116 SET_BIT (si->visited, n);
2117 si->dfs[n] = si->current_index ++;
2118 my_dfs = si->dfs[n];
2120 /* Visit all the successors. */
2121 EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
2123 unsigned int w = si->node_mapping[i];
2125 if (TEST_BIT (si->deleted, w))
2128 if (!TEST_BIT (si->visited, w))
2129 condense_visit (graph, si, w);
2131 unsigned int t = si->node_mapping[w];
2132 unsigned int nnode = si->node_mapping[n];
2133 gcc_assert (nnode == n);
2135 if (si->dfs[t] < si->dfs[nnode])
2136 si->dfs[n] = si->dfs[t];
2140 /* Visit all the implicit predecessors. */
2141 EXECUTE_IF_IN_NONNULL_BITMAP (graph->implicit_preds[n], 0, i, bi)
2143 unsigned int w = si->node_mapping[i];
2145 if (TEST_BIT (si->deleted, w))
2148 if (!TEST_BIT (si->visited, w))
2149 condense_visit (graph, si, w);
2151 unsigned int t = si->node_mapping[w];
2152 unsigned int nnode = si->node_mapping[n];
2153 gcc_assert (nnode == n);
2155 if (si->dfs[t] < si->dfs[nnode])
2156 si->dfs[n] = si->dfs[t];
2160 /* See if any components have been identified. */
2161 if (si->dfs[n] == my_dfs)
2163 while (VEC_length (unsigned, si->scc_stack) != 0
2164 && si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
2166 unsigned int w = VEC_pop (unsigned, si->scc_stack);
2167 si->node_mapping[w] = n;
2169 if (!TEST_BIT (graph->direct_nodes, w))
2170 RESET_BIT (graph->direct_nodes, n);
2172 /* Unify our nodes. */
2173 if (graph->preds[w])
2175 if (!graph->preds[n])
2176 graph->preds[n] = BITMAP_ALLOC (&predbitmap_obstack);
2177 bitmap_ior_into (graph->preds[n], graph->preds[w]);
2179 if (graph->implicit_preds[w])
2181 if (!graph->implicit_preds[n])
2182 graph->implicit_preds[n] = BITMAP_ALLOC (&predbitmap_obstack);
2183 bitmap_ior_into (graph->implicit_preds[n],
2184 graph->implicit_preds[w]);
2186 if (graph->points_to[w])
2188 if (!graph->points_to[n])
2189 graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack);
2190 bitmap_ior_into (graph->points_to[n],
2191 graph->points_to[w]);
2194 SET_BIT (si->deleted, n);
2197 VEC_safe_push (unsigned, heap, si->scc_stack, n);
2200 /* Label pointer equivalences. */
2203 label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
2207 SET_BIT (si->visited, n);
2209 if (!graph->points_to[n])
2210 graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack);
2212 /* Label and union our incoming edges's points to sets. */
2213 EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
2215 unsigned int w = si->node_mapping[i];
2216 if (!TEST_BIT (si->visited, w))
2217 label_visit (graph, si, w);
2219 /* Skip unused edges */
2220 if (w == n || graph->pointer_label[w] == 0)
2223 if (graph->points_to[w])
2224 bitmap_ior_into(graph->points_to[n], graph->points_to[w]);
2226 /* Indirect nodes get fresh variables. */
2227 if (!TEST_BIT (graph->direct_nodes, n))
2228 bitmap_set_bit (graph->points_to[n], FIRST_REF_NODE + n);
2230 if (!bitmap_empty_p (graph->points_to[n]))
2232 unsigned int label = equiv_class_lookup (pointer_equiv_class_table,
2233 graph->points_to[n]);
2236 label = pointer_equiv_class++;
2237 equiv_class_add (pointer_equiv_class_table,
2238 label, graph->points_to[n]);
2240 graph->pointer_label[n] = label;
2244 /* Perform offline variable substitution, discovering equivalence
2245 classes, and eliminating non-pointer variables. */
2247 static struct scc_info *
2248 perform_var_substitution (constraint_graph_t graph)
2251 unsigned int size = graph->size;
2252 struct scc_info *si = init_scc_info (size);
2254 bitmap_obstack_initialize (&iteration_obstack);
2255 pointer_equiv_class_table = htab_create (511, equiv_class_label_hash,
2256 equiv_class_label_eq, free);
2257 location_equiv_class_table = htab_create (511, equiv_class_label_hash,
2258 equiv_class_label_eq, free);
2259 pointer_equiv_class = 1;
2260 location_equiv_class = 1;
2262 /* Condense the nodes, which means to find SCC's, count incoming
2263 predecessors, and unite nodes in SCC's. */
2264 for (i = 0; i < FIRST_REF_NODE; i++)
2265 if (!TEST_BIT (si->visited, si->node_mapping[i]))
2266 condense_visit (graph, si, si->node_mapping[i]);
2268 sbitmap_zero (si->visited);
2269 /* Actually the label the nodes for pointer equivalences */
2270 for (i = 0; i < FIRST_REF_NODE; i++)
2271 if (!TEST_BIT (si->visited, si->node_mapping[i]))
2272 label_visit (graph, si, si->node_mapping[i]);
2274 /* Calculate location equivalence labels. */
2275 for (i = 0; i < FIRST_REF_NODE; i++)
2282 if (!graph->pointed_by[i])
2284 pointed_by = BITMAP_ALLOC (&iteration_obstack);
2286 /* Translate the pointed-by mapping for pointer equivalence
2288 EXECUTE_IF_SET_IN_BITMAP (graph->pointed_by[i], 0, j, bi)
2290 bitmap_set_bit (pointed_by,
2291 graph->pointer_label[si->node_mapping[j]]);
2293 /* The original pointed_by is now dead. */
2294 BITMAP_FREE (graph->pointed_by[i]);
2296 /* Look up the location equivalence label if one exists, or make
2298 label = equiv_class_lookup (location_equiv_class_table,
2302 label = location_equiv_class++;
2303 equiv_class_add (location_equiv_class_table,
2308 if (dump_file && (dump_flags & TDF_DETAILS))
2309 fprintf (dump_file, "Found location equivalence for node %s\n",
2310 get_varinfo (i)->name);
2311 BITMAP_FREE (pointed_by);
2313 graph->loc_label[i] = label;
2317 if (dump_file && (dump_flags & TDF_DETAILS))
2318 for (i = 0; i < FIRST_REF_NODE; i++)
2320 bool direct_node = TEST_BIT (graph->direct_nodes, i);
2322 "Equivalence classes for %s node id %d:%s are pointer: %d"
2324 direct_node ? "Direct node" : "Indirect node", i,
2325 get_varinfo (i)->name,
2326 graph->pointer_label[si->node_mapping[i]],
2327 graph->loc_label[si->node_mapping[i]]);
2330 /* Quickly eliminate our non-pointer variables. */
2332 for (i = 0; i < FIRST_REF_NODE; i++)
2334 unsigned int node = si->node_mapping[i];
2336 if (graph->pointer_label[node] == 0)
2338 if (dump_file && (dump_flags & TDF_DETAILS))
2340 "%s is a non-pointer variable, eliminating edges.\n",
2341 get_varinfo (node)->name);
2342 stats.nonpointer_vars++;
2343 clear_edges_for_node (graph, node);
2350 /* Free information that was only necessary for variable
2354 free_var_substitution_info (struct scc_info *si)
2357 free (graph->pointer_label);
2358 free (graph->loc_label);
2359 free (graph->pointed_by);
2360 free (graph->points_to);
2361 free (graph->eq_rep);
2362 sbitmap_free (graph->direct_nodes);
2363 htab_delete (pointer_equiv_class_table);
2364 htab_delete (location_equiv_class_table);
2365 bitmap_obstack_release (&iteration_obstack);
2368 /* Return an existing node that is equivalent to NODE, which has
2369 equivalence class LABEL, if one exists. Return NODE otherwise. */
2372 find_equivalent_node (constraint_graph_t graph,
2373 unsigned int node, unsigned int label)
2375 /* If the address version of this variable is unused, we can
2376 substitute it for anything else with the same label.
2377 Otherwise, we know the pointers are equivalent, but not the
2378 locations, and we can unite them later. */
2380 if (!bitmap_bit_p (graph->address_taken, node))
2382 gcc_assert (label < graph->size);
2384 if (graph->eq_rep[label] != -1)
2386 /* Unify the two variables since we know they are equivalent. */
2387 if (unite (graph->eq_rep[label], node))
2388 unify_nodes (graph, graph->eq_rep[label], node, false);
2389 return graph->eq_rep[label];
2393 graph->eq_rep[label] = node;
2394 graph->pe_rep[label] = node;
2399 gcc_assert (label < graph->size);
2400 graph->pe[node] = label;
2401 if (graph->pe_rep[label] == -1)
2402 graph->pe_rep[label] = node;
2408 /* Unite pointer equivalent but not location equivalent nodes in
2409 GRAPH. This may only be performed once variable substitution is
2413 unite_pointer_equivalences (constraint_graph_t graph)
2417 /* Go through the pointer equivalences and unite them to their
2418 representative, if they aren't already. */
2419 for (i = 0; i < FIRST_REF_NODE; i++)
2421 unsigned int label = graph->pe[i];
2424 int label_rep = graph->pe_rep[label];
2426 if (label_rep == -1)
2429 label_rep = find (label_rep);
2430 if (label_rep >= 0 && unite (label_rep, find (i)))
2431 unify_nodes (graph, label_rep, i, false);
2436 /* Move complex constraints to the GRAPH nodes they belong to. */
2439 move_complex_constraints (constraint_graph_t graph)
2444 for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
2448 struct constraint_expr lhs = c->lhs;
2449 struct constraint_expr rhs = c->rhs;
2451 if (lhs.type == DEREF)
2453 insert_into_complex (graph, lhs.var, c);
2455 else if (rhs.type == DEREF)
2457 if (!(get_varinfo (lhs.var)->is_special_var))
2458 insert_into_complex (graph, rhs.var, c);
2460 else if (rhs.type != ADDRESSOF && lhs.var > anything_id
2461 && (lhs.offset != 0 || rhs.offset != 0))
2463 insert_into_complex (graph, rhs.var, c);
2470 /* Optimize and rewrite complex constraints while performing
2471 collapsing of equivalent nodes. SI is the SCC_INFO that is the
2472 result of perform_variable_substitution. */
2475 rewrite_constraints (constraint_graph_t graph,
2476 struct scc_info *si)
2482 for (j = 0; j < graph->size; j++)
2483 gcc_assert (find (j) == j);
2485 for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
2487 struct constraint_expr lhs = c->lhs;
2488 struct constraint_expr rhs = c->rhs;
2489 unsigned int lhsvar = find (lhs.var);
2490 unsigned int rhsvar = find (rhs.var);
2491 unsigned int lhsnode, rhsnode;
2492 unsigned int lhslabel, rhslabel;
2494 lhsnode = si->node_mapping[lhsvar];
2495 rhsnode = si->node_mapping[rhsvar];
2496 lhslabel = graph->pointer_label[lhsnode];
2497 rhslabel = graph->pointer_label[rhsnode];
2499 /* See if it is really a non-pointer variable, and if so, ignore
2503 if (dump_file && (dump_flags & TDF_DETAILS))
2506 fprintf (dump_file, "%s is a non-pointer variable,"
2507 "ignoring constraint:",
2508 get_varinfo (lhs.var)->name);
2509 dump_constraint (dump_file, c);
2511 VEC_replace (constraint_t, constraints, i, NULL);
2517 if (dump_file && (dump_flags & TDF_DETAILS))
2520 fprintf (dump_file, "%s is a non-pointer variable,"
2521 "ignoring constraint:",
2522 get_varinfo (rhs.var)->name);
2523 dump_constraint (dump_file, c);
2525 VEC_replace (constraint_t, constraints, i, NULL);
2529 lhsvar = find_equivalent_node (graph, lhsvar, lhslabel);
2530 rhsvar = find_equivalent_node (graph, rhsvar, rhslabel);
2531 c->lhs.var = lhsvar;
2532 c->rhs.var = rhsvar;
2537 /* Eliminate indirect cycles involving NODE. Return true if NODE was
2538 part of an SCC, false otherwise. */
2541 eliminate_indirect_cycles (unsigned int node)
2543 if (graph->indirect_cycles[node] != -1
2544 && !bitmap_empty_p (get_varinfo (node)->solution))
2547 VEC(unsigned,heap) *queue = NULL;
2549 unsigned int to = find (graph->indirect_cycles[node]);
2552 /* We can't touch the solution set and call unify_nodes
2553 at the same time, because unify_nodes is going to do
2554 bitmap unions into it. */
2556 EXECUTE_IF_SET_IN_BITMAP (get_varinfo (node)->solution, 0, i, bi)
2558 if (find (i) == i && i != to)
2561 VEC_safe_push (unsigned, heap, queue, i);
2566 VEC_iterate (unsigned, queue, queuepos, i);
2569 unify_nodes (graph, to, i, true);
2571 VEC_free (unsigned, heap, queue);
2577 /* Solve the constraint graph GRAPH using our worklist solver.
2578 This is based on the PW* family of solvers from the "Efficient Field
2579 Sensitive Pointer Analysis for C" paper.
2580 It works by iterating over all the graph nodes, processing the complex
2581 constraints and propagating the copy constraints, until everything stops
2582 changed. This corresponds to steps 6-8 in the solving list given above. */
2585 solve_graph (constraint_graph_t graph)
2587 unsigned int size = graph->size;
2592 changed = sbitmap_alloc (size);
2593 sbitmap_zero (changed);
2595 /* Mark all initial non-collapsed nodes as changed. */
2596 for (i = 0; i < size; i++)
2598 varinfo_t ivi = get_varinfo (i);
2599 if (find (i) == i && !bitmap_empty_p (ivi->solution)
2600 && ((graph->succs[i] && !bitmap_empty_p (graph->succs[i]))
2601 || VEC_length (constraint_t, graph->complex[i]) > 0))
2603 SET_BIT (changed, i);
2608 /* Allocate a bitmap to be used to store the changed bits. */
2609 pts = BITMAP_ALLOC (&pta_obstack);
2611 while (changed_count > 0)
2614 struct topo_info *ti = init_topo_info ();
2617 bitmap_obstack_initialize (&iteration_obstack);
2619 compute_topo_order (graph, ti);
2621 while (VEC_length (unsigned, ti->topo_order) != 0)
2624 i = VEC_pop (unsigned, ti->topo_order);
2626 /* If this variable is not a representative, skip it. */
2630 /* In certain indirect cycle cases, we may merge this
2631 variable to another. */
2632 if (eliminate_indirect_cycles (i) && find (i) != i)
2635 /* If the node has changed, we need to process the
2636 complex constraints and outgoing edges again. */
2637 if (TEST_BIT (changed, i))
2642 VEC(constraint_t,heap) *complex = graph->complex[i];
2643 bool solution_empty;
2645 RESET_BIT (changed, i);
2648 /* Compute the changed set of solution bits. */
2649 bitmap_and_compl (pts, get_varinfo (i)->solution,
2650 get_varinfo (i)->oldsolution);
2652 if (bitmap_empty_p (pts))
2655 bitmap_ior_into (get_varinfo (i)->oldsolution, pts);
2657 solution = get_varinfo (i)->solution;
2658 solution_empty = bitmap_empty_p (solution);
2660 /* Process the complex constraints */
2661 for (j = 0; VEC_iterate (constraint_t, complex, j, c); j++)
2663 /* XXX: This is going to unsort the constraints in
2664 some cases, which will occasionally add duplicate
2665 constraints during unification. This does not
2666 affect correctness. */
2667 c->lhs.var = find (c->lhs.var);
2668 c->rhs.var = find (c->rhs.var);
2670 /* The only complex constraint that can change our
2671 solution to non-empty, given an empty solution,
2672 is a constraint where the lhs side is receiving
2673 some set from elsewhere. */
2674 if (!solution_empty || c->lhs.type != DEREF)
2675 do_complex_constraint (graph, c, pts);
2678 solution_empty = bitmap_empty_p (solution);
2680 if (!solution_empty)
2683 unsigned eff_escaped_id = find (escaped_id);
2685 /* Propagate solution to all successors. */
2686 EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i],
2692 unsigned int to = find (j);
2693 tmp = get_varinfo (to)->solution;
2696 /* Don't try to propagate to ourselves. */
2700 /* If we propagate from ESCAPED use ESCAPED as
2702 if (i == eff_escaped_id)
2703 flag = bitmap_set_bit (tmp, escaped_id);
2705 flag = set_union_with_increment (tmp, pts, 0);
2709 get_varinfo (to)->solution = tmp;
2710 if (!TEST_BIT (changed, to))
2712 SET_BIT (changed, to);
2720 free_topo_info (ti);
2721 bitmap_obstack_release (&iteration_obstack);
2725 sbitmap_free (changed);
2726 bitmap_obstack_release (&oldpta_obstack);
2729 /* Map from trees to variable infos. */
2730 static struct pointer_map_t *vi_for_tree;
2733 /* Insert ID as the variable id for tree T in the vi_for_tree map. */
2736 insert_vi_for_tree (tree t, varinfo_t vi)
2738 void **slot = pointer_map_insert (vi_for_tree, t);
2740 gcc_assert (*slot == NULL);
2744 /* Find the variable info for tree T in VI_FOR_TREE. If T does not
2745 exist in the map, return NULL, otherwise, return the varinfo we found. */
2748 lookup_vi_for_tree (tree t)
2750 void **slot = pointer_map_contains (vi_for_tree, t);
2754 return (varinfo_t) *slot;
2757 /* Return a printable name for DECL */
2760 alias_get_name (tree decl)
2762 const char *res = get_name (decl);
2764 int num_printed = 0;
2773 if (TREE_CODE (decl) == SSA_NAME)
2775 num_printed = asprintf (&temp, "%s_%u",
2776 alias_get_name (SSA_NAME_VAR (decl)),
2777 SSA_NAME_VERSION (decl));
2779 else if (DECL_P (decl))
2781 num_printed = asprintf (&temp, "D.%u", DECL_UID (decl));
2783 if (num_printed > 0)
2785 res = ggc_strdup (temp);
2791 /* Find the variable id for tree T in the map.
2792 If T doesn't exist in the map, create an entry for it and return it. */
2795 get_vi_for_tree (tree t)
2797 void **slot = pointer_map_contains (vi_for_tree, t);
2799 return get_varinfo (create_variable_info_for (t, alias_get_name (t)));
2801 return (varinfo_t) *slot;
2804 /* Get a scalar constraint expression for a new temporary variable. */
2806 static struct constraint_expr
2807 new_scalar_tmp_constraint_exp (const char *name)
2809 struct constraint_expr tmp;
2812 vi = new_var_info (NULL_TREE, name);
2816 vi->is_full_var = 1;
2825 /* Get a constraint expression vector from an SSA_VAR_P node.
2826 If address_p is true, the result will be taken its address of. */
2829 get_constraint_for_ssa_var (tree t, VEC(ce_s, heap) **results, bool address_p)
2831 struct constraint_expr cexpr;
2834 /* We allow FUNCTION_DECLs here even though it doesn't make much sense. */
2835 gcc_assert (SSA_VAR_P (t) || DECL_P (t));
2837 /* For parameters, get at the points-to set for the actual parm
2839 if (TREE_CODE (t) == SSA_NAME
2840 && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL
2841 && SSA_NAME_IS_DEFAULT_DEF (t))
2843 get_constraint_for_ssa_var (SSA_NAME_VAR (t), results, address_p);
2847 vi = get_vi_for_tree (t);
2849 cexpr.type = SCALAR;
2851 /* If we determine the result is "anything", and we know this is readonly,
2852 say it points to readonly memory instead. */
2853 if (cexpr.var == anything_id && TREE_READONLY (t))
2856 cexpr.type = ADDRESSOF;
2857 cexpr.var = readonly_id;
2860 /* If we are not taking the address of the constraint expr, add all
2861 sub-fiels of the variable as well. */
2863 && !vi->is_full_var)
2865 for (; vi; vi = vi->next)
2868 VEC_safe_push (ce_s, heap, *results, &cexpr);
2873 VEC_safe_push (ce_s, heap, *results, &cexpr);
2876 /* Process constraint T, performing various simplifications and then
2877 adding it to our list of overall constraints. */
2880 process_constraint (constraint_t t)
2882 struct constraint_expr rhs = t->rhs;
2883 struct constraint_expr lhs = t->lhs;
2885 gcc_assert (rhs.var < VEC_length (varinfo_t, varmap));
2886 gcc_assert (lhs.var < VEC_length (varinfo_t, varmap));
2888 /* If we didn't get any useful constraint from the lhs we get
2889 &ANYTHING as fallback from get_constraint_for. Deal with
2890 it here by turning it into *ANYTHING. */
2891 if (lhs.type == ADDRESSOF
2892 && lhs.var == anything_id)
2895 /* ADDRESSOF on the lhs is invalid. */
2896 gcc_assert (lhs.type != ADDRESSOF);
2898 /* We shouldn't add constraints from things that cannot have pointers.
2899 It's not completely trivial to avoid in the callers, so do it here. */
2900 if (rhs.type != ADDRESSOF
2901 && !get_varinfo (rhs.var)->may_have_pointers)
2904 /* Likewise adding to the solution of a non-pointer var isn't useful. */
2905 if (!get_varinfo (lhs.var)->may_have_pointers)
2908 /* This can happen in our IR with things like n->a = *p */
2909 if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
2911 /* Split into tmp = *rhs, *lhs = tmp */
2912 struct constraint_expr tmplhs;
2913 tmplhs = new_scalar_tmp_constraint_exp ("doubledereftmp");
2914 process_constraint (new_constraint (tmplhs, rhs));
2915 process_constraint (new_constraint (lhs, tmplhs));
2917 else if (rhs.type == ADDRESSOF && lhs.type == DEREF)
2919 /* Split into tmp = &rhs, *lhs = tmp */
2920 struct constraint_expr tmplhs;
2921 tmplhs = new_scalar_tmp_constraint_exp ("derefaddrtmp");
2922 process_constraint (new_constraint (tmplhs, rhs));
2923 process_constraint (new_constraint (lhs, tmplhs));
2927 gcc_assert (rhs.type != ADDRESSOF || rhs.offset == 0);
2928 VEC_safe_push (constraint_t, heap, constraints, t);
2932 /* Return true if T is a type that could contain pointers. */
2935 type_could_have_pointers (tree type)
2937 if (POINTER_TYPE_P (type))
2940 if (TREE_CODE (type) == ARRAY_TYPE)
2941 return type_could_have_pointers (TREE_TYPE (type));
2943 return AGGREGATE_TYPE_P (type);
2946 /* Return true if T is a variable of a type that could contain
2950 could_have_pointers (tree t)
2952 return type_could_have_pointers (TREE_TYPE (t));
2955 /* Return the position, in bits, of FIELD_DECL from the beginning of its
2958 static HOST_WIDE_INT
2959 bitpos_of_field (const tree fdecl)
2962 if (!host_integerp (DECL_FIELD_OFFSET (fdecl), 0)
2963 || !host_integerp (DECL_FIELD_BIT_OFFSET (fdecl), 0))
2966 return (TREE_INT_CST_LOW (DECL_FIELD_OFFSET (fdecl)) * 8
2967 + TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fdecl)));
2971 /* Get constraint expressions for offsetting PTR by OFFSET. Stores the
2972 resulting constraint expressions in *RESULTS. */
2975 get_constraint_for_ptr_offset (tree ptr, tree offset,
2976 VEC (ce_s, heap) **results)
2978 struct constraint_expr c;
2980 HOST_WIDE_INT rhsunitoffset, rhsoffset;
2982 /* If we do not do field-sensitive PTA adding offsets to pointers
2983 does not change the points-to solution. */
2984 if (!use_field_sensitive)
2986 get_constraint_for (ptr, results);
2990 /* If the offset is not a non-negative integer constant that fits
2991 in a HOST_WIDE_INT, we have to fall back to a conservative
2992 solution which includes all sub-fields of all pointed-to
2993 variables of ptr. */
2994 if (offset == NULL_TREE
2995 || !host_integerp (offset, 0))
2996 rhsoffset = UNKNOWN_OFFSET;
2999 /* Make sure the bit-offset also fits. */
3000 rhsunitoffset = TREE_INT_CST_LOW (offset);
3001 rhsoffset = rhsunitoffset * BITS_PER_UNIT;
3002 if (rhsunitoffset != rhsoffset / BITS_PER_UNIT)
3003 rhsoffset = UNKNOWN_OFFSET;
3006 get_constraint_for (ptr, results);
3010 /* As we are eventually appending to the solution do not use
3011 VEC_iterate here. */
3012 n = VEC_length (ce_s, *results);
3013 for (j = 0; j < n; j++)
3016 c = *VEC_index (ce_s, *results, j);
3017 curr = get_varinfo (c.var);
3019 if (c.type == ADDRESSOF
3020 /* If this varinfo represents a full variable just use it. */
3021 && curr->is_full_var)
3023 else if (c.type == ADDRESSOF
3024 /* If we do not know the offset add all subfields. */
3025 && rhsoffset == UNKNOWN_OFFSET)
3027 varinfo_t temp = lookup_vi_for_tree (curr->decl);
3030 struct constraint_expr c2;
3032 c2.type = ADDRESSOF;
3034 if (c2.var != c.var)
3035 VEC_safe_push (ce_s, heap, *results, &c2);
3040 else if (c.type == ADDRESSOF)
3043 unsigned HOST_WIDE_INT offset = curr->offset + rhsoffset;
3045 /* Search the sub-field which overlaps with the
3046 pointed-to offset. If the result is outside of the variable
3047 we have to provide a conservative result, as the variable is
3048 still reachable from the resulting pointer (even though it
3049 technically cannot point to anything). The last and first
3050 sub-fields are such conservative results.
3051 ??? If we always had a sub-field for &object + 1 then
3052 we could represent this in a more precise way. */
3054 && curr->offset < offset)
3056 temp = first_or_preceding_vi_for_offset (curr, offset);
3058 /* If the found variable is not exactly at the pointed to
3059 result, we have to include the next variable in the
3060 solution as well. Otherwise two increments by offset / 2
3061 do not result in the same or a conservative superset
3063 if (temp->offset != offset
3064 && temp->next != NULL)
3066 struct constraint_expr c2;
3067 c2.var = temp->next->id;
3068 c2.type = ADDRESSOF;
3070 VEC_safe_push (ce_s, heap, *results, &c2);
3076 c.offset = rhsoffset;
3078 VEC_replace (ce_s, *results, j, &c);
3083 /* Given a COMPONENT_REF T, return the constraint_expr vector for it.
3084 If address_p is true the result will be taken its address of. */
3087 get_constraint_for_component_ref (tree t, VEC(ce_s, heap) **results,
3091 HOST_WIDE_INT bitsize = -1;
3092 HOST_WIDE_INT bitmaxsize = -1;
3093 HOST_WIDE_INT bitpos;
3095 struct constraint_expr *result;
3097 /* Some people like to do cute things like take the address of
3100 while (handled_component_p (forzero)
3101 || INDIRECT_REF_P (forzero))
3102 forzero = TREE_OPERAND (forzero, 0);
3104 if (CONSTANT_CLASS_P (forzero) && integer_zerop (forzero))
3106 struct constraint_expr temp;
3109 temp.var = integer_id;
3111 VEC_safe_push (ce_s, heap, *results, &temp);
3115 t = get_ref_base_and_extent (t, &bitpos, &bitsize, &bitmaxsize);
3117 /* Pretend to take the address of the base, we'll take care of
3118 adding the required subset of sub-fields below. */
3119 get_constraint_for_1 (t, results, true);
3120 gcc_assert (VEC_length (ce_s, *results) == 1);
3121 result = VEC_last (ce_s, *results);
3123 if (result->type == SCALAR
3124 && get_varinfo (result->var)->is_full_var)
3125 /* For single-field vars do not bother about the offset. */
3127 else if (result->type == SCALAR)
3129 /* In languages like C, you can access one past the end of an
3130 array. You aren't allowed to dereference it, so we can
3131 ignore this constraint. When we handle pointer subtraction,
3132 we may have to do something cute here. */
3134 if ((unsigned HOST_WIDE_INT)bitpos < get_varinfo (result->var)->fullsize
3137 /* It's also not true that the constraint will actually start at the
3138 right offset, it may start in some padding. We only care about
3139 setting the constraint to the first actual field it touches, so
3141 struct constraint_expr cexpr = *result;
3143 VEC_pop (ce_s, *results);
3145 for (curr = get_varinfo (cexpr.var); curr; curr = curr->next)
3147 if (ranges_overlap_p (curr->offset, curr->size,
3148 bitpos, bitmaxsize))
3150 cexpr.var = curr->id;
3151 VEC_safe_push (ce_s, heap, *results, &cexpr);
3156 /* If we are going to take the address of this field then
3157 to be able to compute reachability correctly add at least
3158 the last field of the variable. */
3160 && VEC_length (ce_s, *results) == 0)
3162 curr = get_varinfo (cexpr.var);
3163 while (curr->next != NULL)
3165 cexpr.var = curr->id;
3166 VEC_safe_push (ce_s, heap, *results, &cexpr);
3169 /* Assert that we found *some* field there. The user couldn't be
3170 accessing *only* padding. */
3171 /* Still the user could access one past the end of an array
3172 embedded in a struct resulting in accessing *only* padding. */
3173 gcc_assert (VEC_length (ce_s, *results) >= 1
3174 || ref_contains_array_ref (orig_t));
3176 else if (bitmaxsize == 0)
3178 if (dump_file && (dump_flags & TDF_DETAILS))
3179 fprintf (dump_file, "Access to zero-sized part of variable,"
3183 if (dump_file && (dump_flags & TDF_DETAILS))
3184 fprintf (dump_file, "Access to past the end of variable, ignoring\n");
3186 else if (result->type == DEREF)
3188 /* If we do not know exactly where the access goes say so. Note
3189 that only for non-structure accesses we know that we access
3190 at most one subfiled of any variable. */
3192 || bitsize != bitmaxsize
3193 || AGGREGATE_TYPE_P (TREE_TYPE (orig_t)))
3194 result->offset = UNKNOWN_OFFSET;
3196 result->offset = bitpos;
3198 else if (result->type == ADDRESSOF)
3200 /* We can end up here for component references on a
3201 VIEW_CONVERT_EXPR <>(&foobar). */
3202 result->type = SCALAR;
3203 result->var = anything_id;
3211 /* Dereference the constraint expression CONS, and return the result.
3212 DEREF (ADDRESSOF) = SCALAR
3213 DEREF (SCALAR) = DEREF
3214 DEREF (DEREF) = (temp = DEREF1; result = DEREF(temp))
3215 This is needed so that we can handle dereferencing DEREF constraints. */
3218 do_deref (VEC (ce_s, heap) **constraints)
3220 struct constraint_expr *c;
3223 for (i = 0; VEC_iterate (ce_s, *constraints, i, c); i++)
3225 if (c->type == SCALAR)
3227 else if (c->type == ADDRESSOF)
3229 else if (c->type == DEREF)
3231 struct constraint_expr tmplhs;
3232 tmplhs = new_scalar_tmp_constraint_exp ("dereftmp");
3233 process_constraint (new_constraint (tmplhs, *c));
3234 c->var = tmplhs.var;
3241 static void get_constraint_for_1 (tree, VEC (ce_s, heap) **, bool);
3243 /* Given a tree T, return the constraint expression for taking the
3247 get_constraint_for_address_of (tree t, VEC (ce_s, heap) **results)
3249 struct constraint_expr *c;
3252 get_constraint_for_1 (t, results, true);
3254 for (i = 0; VEC_iterate (ce_s, *results, i, c); i++)
3256 if (c->type == DEREF)
3259 c->type = ADDRESSOF;
3263 /* Given a tree T, return the constraint expression for it. */
3266 get_constraint_for_1 (tree t, VEC (ce_s, heap) **results, bool address_p)
3268 struct constraint_expr temp;
3270 /* x = integer is all glommed to a single variable, which doesn't
3271 point to anything by itself. That is, of course, unless it is an
3272 integer constant being treated as a pointer, in which case, we
3273 will return that this is really the addressof anything. This
3274 happens below, since it will fall into the default case. The only
3275 case we know something about an integer treated like a pointer is
3276 when it is the NULL pointer, and then we just say it points to
3279 Do not do that if -fno-delete-null-pointer-checks though, because
3280 in that case *NULL does not fail, so it _should_ alias *anything.
3281 It is not worth adding a new option or renaming the existing one,
3282 since this case is relatively obscure. */
3283 if (flag_delete_null_pointer_checks
3284 && ((TREE_CODE (t) == INTEGER_CST
3285 && integer_zerop (t))
3286 /* The only valid CONSTRUCTORs in gimple with pointer typed
3287 elements are zero-initializer. But in IPA mode we also
3288 process global initializers, so verify at least. */
3289 || (TREE_CODE (t) == CONSTRUCTOR
3290 && CONSTRUCTOR_NELTS (t) == 0)))
3292 temp.var = nothing_id;
3293 temp.type = ADDRESSOF;
3295 VEC_safe_push (ce_s, heap, *results, &temp);
3299 /* String constants are read-only. */
3300 if (TREE_CODE (t) == STRING_CST)
3302 temp.var = readonly_id;
3305 VEC_safe_push (ce_s, heap, *results, &temp);
3309 switch (TREE_CODE_CLASS (TREE_CODE (t)))
3311 case tcc_expression:
3313 switch (TREE_CODE (t))
3316 get_constraint_for_address_of (TREE_OPERAND (t, 0), results);
3324 switch (TREE_CODE (t))
3328 get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p);
3333 case ARRAY_RANGE_REF:
3335 get_constraint_for_component_ref (t, results, address_p);
3337 case VIEW_CONVERT_EXPR:
3338 get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p);
3340 /* We are missing handling for TARGET_MEM_REF here. */
3345 case tcc_exceptional:
3347 switch (TREE_CODE (t))
3351 get_constraint_for_ssa_var (t, results, address_p);
3358 case tcc_declaration:
3360 get_constraint_for_ssa_var (t, results, address_p);
3366 /* The default fallback is a constraint from anything. */
3367 temp.type = ADDRESSOF;
3368 temp.var = anything_id;
3370 VEC_safe_push (ce_s, heap, *results, &temp);
3373 /* Given a gimple tree T, return the constraint expression vector for it. */
3376 get_constraint_for (tree t, VEC (ce_s, heap) **results)
3378 gcc_assert (VEC_length (ce_s, *results) == 0);
3380 get_constraint_for_1 (t, results, false);
3384 /* Efficiently generates constraints from all entries in *RHSC to all
3385 entries in *LHSC. */
3388 process_all_all_constraints (VEC (ce_s, heap) *lhsc, VEC (ce_s, heap) *rhsc)
3390 struct constraint_expr *lhsp, *rhsp;
3393 if (VEC_length (ce_s, lhsc) <= 1
3394 || VEC_length (ce_s, rhsc) <= 1)
3396 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
3397 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); ++j)
3398 process_constraint (new_constraint (*lhsp, *rhsp));
3402 struct constraint_expr tmp;
3403 tmp = new_scalar_tmp_constraint_exp ("allalltmp");
3404 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
3405 process_constraint (new_constraint (tmp, *rhsp));
3406 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
3407 process_constraint (new_constraint (*lhsp, tmp));
3411 /* Handle aggregate copies by expanding into copies of the respective
3412 fields of the structures. */
3415 do_structure_copy (tree lhsop, tree rhsop)
3417 struct constraint_expr *lhsp, *rhsp;
3418 VEC (ce_s, heap) *lhsc = NULL, *rhsc = NULL;
3421 get_constraint_for (lhsop, &lhsc);
3422 get_constraint_for (rhsop, &rhsc);
3423 lhsp = VEC_index (ce_s, lhsc, 0);
3424 rhsp = VEC_index (ce_s, rhsc, 0);
3425 if (lhsp->type == DEREF
3426 || (lhsp->type == ADDRESSOF && lhsp->var == anything_id)
3427 || rhsp->type == DEREF)
3429 if (lhsp->type == DEREF)
3431 gcc_assert (VEC_length (ce_s, lhsc) == 1);
3432 lhsp->offset = UNKNOWN_OFFSET;
3434 if (rhsp->type == DEREF)
3436 gcc_assert (VEC_length (ce_s, rhsc) == 1);
3437 rhsp->offset = UNKNOWN_OFFSET;
3439 process_all_all_constraints (lhsc, rhsc);
3441 else if (lhsp->type == SCALAR
3442 && (rhsp->type == SCALAR
3443 || rhsp->type == ADDRESSOF))
3445 HOST_WIDE_INT lhssize, lhsmaxsize, lhsoffset;
3446 HOST_WIDE_INT rhssize, rhsmaxsize, rhsoffset;
3448 get_ref_base_and_extent (lhsop, &lhsoffset, &lhssize, &lhsmaxsize);
3449 get_ref_base_and_extent (rhsop, &rhsoffset, &rhssize, &rhsmaxsize);
3450 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp);)
3452 varinfo_t lhsv, rhsv;
3453 rhsp = VEC_index (ce_s, rhsc, k);
3454 lhsv = get_varinfo (lhsp->var);
3455 rhsv = get_varinfo (rhsp->var);
3456 if (lhsv->may_have_pointers
3457 && ranges_overlap_p (lhsv->offset + rhsoffset, lhsv->size,
3458 rhsv->offset + lhsoffset, rhsv->size))
3459 process_constraint (new_constraint (*lhsp, *rhsp));
3460 if (lhsv->offset + rhsoffset + lhsv->size
3461 > rhsv->offset + lhsoffset + rhsv->size)
3464 if (k >= VEC_length (ce_s, rhsc))
3474 VEC_free (ce_s, heap, lhsc);
3475 VEC_free (ce_s, heap, rhsc);
3478 /* Create a constraint ID = OP. */
3481 make_constraint_to (unsigned id, tree op)
3483 VEC(ce_s, heap) *rhsc = NULL;
3484 struct constraint_expr *c;
3485 struct constraint_expr includes;
3489 includes.offset = 0;
3490 includes.type = SCALAR;
3492 get_constraint_for (op, &rhsc);
3493 for (j = 0; VEC_iterate (ce_s, rhsc, j, c); j++)
3494 process_constraint (new_constraint (includes, *c));
3495 VEC_free (ce_s, heap, rhsc);
3498 /* Create a constraint ID = &FROM. */
3501 make_constraint_from (varinfo_t vi, int from)
3503 struct constraint_expr lhs, rhs;
3511 rhs.type = ADDRESSOF;
3512 process_constraint (new_constraint (lhs, rhs));
3515 /* Create a constraint ID = FROM. */
3518 make_copy_constraint (varinfo_t vi, int from)
3520 struct constraint_expr lhs, rhs;
3529 process_constraint (new_constraint (lhs, rhs));
3532 /* Make constraints necessary to make OP escape. */
3535 make_escape_constraint (tree op)
3537 make_constraint_to (escaped_id, op);
3540 /* Add constraints to that the solution of VI is transitively closed. */
3543 make_transitive_closure_constraints (varinfo_t vi)
3545 struct constraint_expr lhs, rhs;
3554 process_constraint (new_constraint (lhs, rhs));
3556 /* VAR = VAR + UNKNOWN; */
3562 rhs.offset = UNKNOWN_OFFSET;
3563 process_constraint (new_constraint (lhs, rhs));
3566 /* Create a new artificial heap variable with NAME and make a
3567 constraint from it to LHS. Return the created variable. */
3570 make_constraint_from_heapvar (varinfo_t lhs, const char *name)
3573 tree heapvar = heapvar_lookup (lhs->decl, lhs->offset);
3575 if (heapvar == NULL_TREE)
3578 heapvar = create_tmp_var_raw (ptr_type_node, name);
3579 DECL_EXTERNAL (heapvar) = 1;
3581 heapvar_insert (lhs->decl, lhs->offset, heapvar);
3583 ann = get_var_ann (heapvar);
3584 ann->is_heapvar = 1;
3587 /* For global vars we need to add a heapvar to the list of referenced
3588 vars of a different function than it was created for originally. */
3589 if (cfun && gimple_referenced_vars (cfun))
3590 add_referenced_var (heapvar);
3592 vi = new_var_info (heapvar, name);
3593 vi->is_artificial_var = true;
3594 vi->is_heap_var = true;
3595 vi->is_unknown_size_var = true;
3599 vi->is_full_var = true;
3600 insert_vi_for_tree (heapvar, vi);
3602 make_constraint_from (lhs, vi->id);
3607 /* Create a new artificial heap variable with NAME and make a
3608 constraint from it to LHS. Set flags according to a tag used
3609 for tracking restrict pointers. */
3612 make_constraint_from_restrict (varinfo_t lhs, const char *name)
3615 vi = make_constraint_from_heapvar (lhs, name);
3616 vi->is_restrict_var = 1;
3617 vi->is_global_var = 0;
3618 vi->is_special_var = 1;
3619 vi->may_have_pointers = 0;
3622 /* In IPA mode there are varinfos for different aspects of reach
3623 function designator. One for the points-to set of the return
3624 value, one for the variables that are clobbered by the function,
3625 one for its uses and one for each parameter (including a single
3626 glob for remaining variadic arguments). */
3628 enum { fi_clobbers = 1, fi_uses = 2,
3629 fi_static_chain = 3, fi_result = 4, fi_parm_base = 5 };
3631 /* Get a constraint for the requested part of a function designator FI
3632 when operating in IPA mode. */
3634 static struct constraint_expr
3635 get_function_part_constraint (varinfo_t fi, unsigned part)
3637 struct constraint_expr c;
3639 gcc_assert (in_ipa_mode);
3641 if (fi->id == anything_id)
3643 /* ??? We probably should have a ANYFN special variable. */
3644 c.var = anything_id;
3648 else if (TREE_CODE (fi->decl) == FUNCTION_DECL)
3650 varinfo_t ai = first_vi_for_offset (fi, part);
3654 c.var = anything_id;
3668 /* For non-IPA mode, generate constraints necessary for a call on the
3672 handle_rhs_call (gimple stmt, VEC(ce_s, heap) **results)
3674 struct constraint_expr rhsc;
3677 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3679 tree arg = gimple_call_arg (stmt, i);
3681 /* Find those pointers being passed, and make sure they end up
3682 pointing to anything. */
3683 if (could_have_pointers (arg))
3684 make_escape_constraint (arg);
3687 /* The static chain escapes as well. */
3688 if (gimple_call_chain (stmt))
3689 make_escape_constraint (gimple_call_chain (stmt));
3691 /* And if we applied NRV the address of the return slot escapes as well. */
3692 if (gimple_call_return_slot_opt_p (stmt)
3693 && gimple_call_lhs (stmt) != NULL_TREE
3694 && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt))))
3696 VEC(ce_s, heap) *tmpc = NULL;
3697 struct constraint_expr lhsc, *c;
3698 get_constraint_for_address_of (gimple_call_lhs (stmt), &tmpc);
3699 lhsc.var = escaped_id;
3702 for (i = 0; VEC_iterate (ce_s, tmpc, i, c); ++i)
3703 process_constraint (new_constraint (lhsc, *c));
3704 VEC_free(ce_s, heap, tmpc);
3707 /* Regular functions return nonlocal memory. */
3708 rhsc.var = nonlocal_id;
3711 VEC_safe_push (ce_s, heap, *results, &rhsc);
3714 /* For non-IPA mode, generate constraints necessary for a call
3715 that returns a pointer and assigns it to LHS. This simply makes
3716 the LHS point to global and escaped variables. */
3719 handle_lhs_call (tree lhs, int flags, VEC(ce_s, heap) *rhsc, tree fndecl)
3721 VEC(ce_s, heap) *lhsc = NULL;
3723 get_constraint_for (lhs, &lhsc);
3725 if (flags & ECF_MALLOC)
3728 vi = make_constraint_from_heapvar (get_vi_for_tree (lhs), "HEAP");
3729 /* We delay marking allocated storage global until we know if
3731 DECL_EXTERNAL (vi->decl) = 0;
3732 vi->is_global_var = 0;
3733 /* If this is not a real malloc call assume the memory was
3734 initialized and thus may point to global memory. All
3735 builtin functions with the malloc attribute behave in a sane way. */
3737 || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
3738 make_constraint_from (vi, nonlocal_id);
3740 else if (VEC_length (ce_s, rhsc) > 0)
3742 /* If the store is to a global decl make sure to
3743 add proper escape constraints. */
3744 lhs = get_base_address (lhs);
3747 && is_global_var (lhs))
3749 struct constraint_expr tmpc;
3750 tmpc.var = escaped_id;
3753 VEC_safe_push (ce_s, heap, lhsc, &tmpc);
3755 process_all_all_constraints (lhsc, rhsc);
3757 VEC_free (ce_s, heap, lhsc);
3760 /* For non-IPA mode, generate constraints necessary for a call of a
3761 const function that returns a pointer in the statement STMT. */
3764 handle_const_call (gimple stmt, VEC(ce_s, heap) **results)
3766 struct constraint_expr rhsc;
3769 /* Treat nested const functions the same as pure functions as far
3770 as the static chain is concerned. */
3771 if (gimple_call_chain (stmt))
3773 varinfo_t uses = get_call_use_vi (stmt);
3774 make_transitive_closure_constraints (uses);
3775 make_constraint_to (uses->id, gimple_call_chain (stmt));
3776 rhsc.var = uses->id;
3779 VEC_safe_push (ce_s, heap, *results, &rhsc);
3782 /* May return arguments. */
3783 for (k = 0; k < gimple_call_num_args (stmt); ++k)
3785 tree arg = gimple_call_arg (stmt, k);
3787 if (could_have_pointers (arg))
3789 VEC(ce_s, heap) *argc = NULL;
3791 struct constraint_expr *argp;
3792 get_constraint_for (arg, &argc);
3793 for (i = 0; VEC_iterate (ce_s, argc, i, argp); ++i)
3794 VEC_safe_push (ce_s, heap, *results, argp);
3795 VEC_free(ce_s, heap, argc);
3799 /* May return addresses of globals. */
3800 rhsc.var = nonlocal_id;
3802 rhsc.type = ADDRESSOF;
3803 VEC_safe_push (ce_s, heap, *results, &rhsc);
3806 /* For non-IPA mode, generate constraints necessary for a call to a
3807 pure function in statement STMT. */
3810 handle_pure_call (gimple stmt, VEC(ce_s, heap) **results)
3812 struct constraint_expr rhsc;
3814 varinfo_t uses = NULL;
3816 /* Memory reached from pointer arguments is call-used. */
3817 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3819 tree arg = gimple_call_arg (stmt, i);
3821 if (could_have_pointers (arg))
3825 uses = get_call_use_vi (stmt);
3826 make_transitive_closure_constraints (uses);
3828 make_constraint_to (uses->id, arg);
3832 /* The static chain is used as well. */
3833 if (gimple_call_chain (stmt))
3837 uses = get_call_use_vi (stmt);
3838 make_transitive_closure_constraints (uses);
3840 make_constraint_to (uses->id, gimple_call_chain (stmt));
3843 /* Pure functions may return call-used and nonlocal memory. */
3846 rhsc.var = uses->id;
3849 VEC_safe_push (ce_s, heap, *results, &rhsc);
3851 rhsc.var = nonlocal_id;
3854 VEC_safe_push (ce_s, heap, *results, &rhsc);
3858 /* Return the varinfo for the callee of CALL. */
3861 get_fi_for_callee (gimple call)
3865 /* If we can directly resolve the function being called, do so.
3866 Otherwise, it must be some sort of indirect expression that
3867 we should still be able to handle. */
3868 decl = gimple_call_fndecl (call);
3870 return get_vi_for_tree (decl);
3872 decl = gimple_call_fn (call);
3873 /* The function can be either an SSA name pointer or,
3874 worse, an OBJ_TYPE_REF. In this case we have no
3875 clue and should be getting ANYFN (well, ANYTHING for now). */
3876 if (TREE_CODE (decl) == SSA_NAME)
3878 if (TREE_CODE (decl) == SSA_NAME
3879 && TREE_CODE (SSA_NAME_VAR (decl)) == PARM_DECL
3880 && SSA_NAME_IS_DEFAULT_DEF (decl))
3881 decl = SSA_NAME_VAR (decl);
3882 return get_vi_for_tree (decl);
3884 else if (TREE_CODE (decl) == INTEGER_CST
3885 || TREE_CODE (decl) == OBJ_TYPE_REF)
3886 return get_varinfo (anything_id);
3891 /* Walk statement T setting up aliasing constraints according to the
3892 references found in T. This function is the main part of the
3893 constraint builder. AI points to auxiliary alias information used
3894 when building alias sets and computing alias grouping heuristics. */
3897 find_func_aliases (gimple origt)
3900 VEC(ce_s, heap) *lhsc = NULL;
3901 VEC(ce_s, heap) *rhsc = NULL;
3902 struct constraint_expr *c;
3905 /* Now build constraints expressions. */
3906 if (gimple_code (t) == GIMPLE_PHI)
3908 gcc_assert (!AGGREGATE_TYPE_P (TREE_TYPE (gimple_phi_result (t))));
3910 /* Only care about pointers and structures containing
3912 if (could_have_pointers (gimple_phi_result (t)))
3917 /* For a phi node, assign all the arguments to
3919 get_constraint_for (gimple_phi_result (t), &lhsc);
3920 for (i = 0; i < gimple_phi_num_args (t); i++)
3922 tree strippedrhs = PHI_ARG_DEF (t, i);
3924 STRIP_NOPS (strippedrhs);
3925 get_constraint_for (gimple_phi_arg_def (t, i), &rhsc);
3927 for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
3929 struct constraint_expr *c2;
3930 while (VEC_length (ce_s, rhsc) > 0)
3932 c2 = VEC_last (ce_s, rhsc);
3933 process_constraint (new_constraint (*c, *c2));
3934 VEC_pop (ce_s, rhsc);
3940 /* In IPA mode, we need to generate constraints to pass call
3941 arguments through their calls. There are two cases,
3942 either a GIMPLE_CALL returning a value, or just a plain
3943 GIMPLE_CALL when we are not.
3945 In non-ipa mode, we need to generate constraints for each
3946 pointer passed by address. */
3947 else if (is_gimple_call (t))
3949 tree fndecl = gimple_call_fndecl (t);
3950 if (fndecl != NULL_TREE
3951 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
3952 /* ??? All builtins that are handled here need to be handled
3953 in the alias-oracle query functions explicitly! */
3954 switch (DECL_FUNCTION_CODE (fndecl))
3956 /* All the following functions return a pointer to the same object
3957 as their first argument points to. The functions do not add
3958 to the ESCAPED solution. The functions make the first argument
3959 pointed to memory point to what the second argument pointed to
3960 memory points to. */
3961 case BUILT_IN_STRCPY:
3962 case BUILT_IN_STRNCPY:
3963 case BUILT_IN_BCOPY:
3964 case BUILT_IN_MEMCPY:
3965 case BUILT_IN_MEMMOVE:
3966 case BUILT_IN_MEMPCPY:
3967 case BUILT_IN_STPCPY:
3968 case BUILT_IN_STPNCPY:
3969 case BUILT_IN_STRCAT:
3970 case BUILT_IN_STRNCAT:
3972 tree res = gimple_call_lhs (t);
3973 tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
3974 == BUILT_IN_BCOPY ? 1 : 0));
3975 tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
3976 == BUILT_IN_BCOPY ? 0 : 1));
3977 if (res != NULL_TREE)
3979 get_constraint_for (res, &lhsc);
3980 if (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMPCPY
3981 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPCPY
3982 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPNCPY)
3983 get_constraint_for_ptr_offset (dest, NULL_TREE, &rhsc);
3985 get_constraint_for (dest, &rhsc);
3986 process_all_all_constraints (lhsc, rhsc);
3987 VEC_free (ce_s, heap, lhsc);
3988 VEC_free (ce_s, heap, rhsc);
3990 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
3991 get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
3994 process_all_all_constraints (lhsc, rhsc);
3995 VEC_free (ce_s, heap, lhsc);
3996 VEC_free (ce_s, heap, rhsc);
3999 case BUILT_IN_MEMSET:
4001 tree res = gimple_call_lhs (t);
4002 tree dest = gimple_call_arg (t, 0);
4005 struct constraint_expr ac;
4006 if (res != NULL_TREE)
4008 get_constraint_for (res, &lhsc);
4009 get_constraint_for (dest, &rhsc);
4010 process_all_all_constraints (lhsc, rhsc);
4011 VEC_free (ce_s, heap, lhsc);
4012 VEC_free (ce_s, heap, rhsc);
4014 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4016 if (flag_delete_null_pointer_checks
4017 && integer_zerop (gimple_call_arg (t, 1)))
4019 ac.type = ADDRESSOF;
4020 ac.var = nothing_id;
4025 ac.var = integer_id;
4028 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
4029 process_constraint (new_constraint (*lhsp, ac));
4030 VEC_free (ce_s, heap, lhsc);
4033 /* All the following functions do not return pointers, do not
4034 modify the points-to sets of memory reachable from their
4035 arguments and do not add to the ESCAPED solution. */
4036 case BUILT_IN_SINCOS:
4037 case BUILT_IN_SINCOSF:
4038 case BUILT_IN_SINCOSL:
4039 case BUILT_IN_FREXP:
4040 case BUILT_IN_FREXPF:
4041 case BUILT_IN_FREXPL:
4042 case BUILT_IN_GAMMA_R:
4043 case BUILT_IN_GAMMAF_R:
4044 case BUILT_IN_GAMMAL_R:
4045 case BUILT_IN_LGAMMA_R:
4046 case BUILT_IN_LGAMMAF_R:
4047 case BUILT_IN_LGAMMAL_R:
4049 case BUILT_IN_MODFF:
4050 case BUILT_IN_MODFL:
4051 case BUILT_IN_REMQUO:
4052 case BUILT_IN_REMQUOF:
4053 case BUILT_IN_REMQUOL:
4056 /* Trampolines are special - they set up passing the static
4058 case BUILT_IN_INIT_TRAMPOLINE:
4060 tree tramp = gimple_call_arg (t, 0);
4061 tree nfunc = gimple_call_arg (t, 1);
4062 tree frame = gimple_call_arg (t, 2);
4064 struct constraint_expr lhs, *rhsp;
4067 varinfo_t nfi = NULL;
4068 gcc_assert (TREE_CODE (nfunc) == ADDR_EXPR);
4069 nfi = lookup_vi_for_tree (TREE_OPERAND (nfunc, 0));
4072 lhs = get_function_part_constraint (nfi, fi_static_chain);
4073 get_constraint_for (frame, &rhsc);
4074 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
4075 process_constraint (new_constraint (lhs, *rhsp));
4076 VEC_free (ce_s, heap, rhsc);
4078 /* Make the frame point to the function for
4079 the trampoline adjustment call. */
4080 get_constraint_for (tramp, &lhsc);
4082 get_constraint_for (nfunc, &rhsc);
4083 process_all_all_constraints (lhsc, rhsc);
4084 VEC_free (ce_s, heap, rhsc);
4085 VEC_free (ce_s, heap, lhsc);
4090 /* Else fallthru to generic handling which will let
4091 the frame escape. */
4094 case BUILT_IN_ADJUST_TRAMPOLINE:
4096 tree tramp = gimple_call_arg (t, 0);
4097 tree res = gimple_call_lhs (t);
4098 if (in_ipa_mode && res)
4100 get_constraint_for (res, &lhsc);
4101 get_constraint_for (tramp, &rhsc);
4103 process_all_all_constraints (lhsc, rhsc);
4104 VEC_free (ce_s, heap, rhsc);
4105 VEC_free (ce_s, heap, lhsc);
4109 /* Variadic argument handling needs to be handled in IPA
4111 case BUILT_IN_VA_START:
4115 tree valist = gimple_call_arg (t, 0);
4116 struct constraint_expr rhs, *lhsp;
4118 /* The va_list gets access to pointers in variadic
4120 fi = lookup_vi_for_tree (cfun->decl);
4121 gcc_assert (fi != NULL);
4122 get_constraint_for (valist, &lhsc);
4124 rhs = get_function_part_constraint (fi, ~0);
4125 rhs.type = ADDRESSOF;
4126 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
4127 process_constraint (new_constraint (*lhsp, rhs));
4128 VEC_free (ce_s, heap, lhsc);
4129 /* va_list is clobbered. */
4130 make_constraint_to (get_call_clobber_vi (t)->id, valist);
4135 /* va_end doesn't have any effect that matters. */
4136 case BUILT_IN_VA_END:
4138 /* printf-style functions may have hooks to set pointers to
4139 point to somewhere into the generated string. Leave them
4140 for a later excercise... */
4142 /* Fallthru to general call handling. */;
4146 && (!(fi = lookup_vi_for_tree (fndecl))
4147 || !fi->is_fn_info)))
4149 VEC(ce_s, heap) *rhsc = NULL;
4150 int flags = gimple_call_flags (t);
4152 /* Const functions can return their arguments and addresses
4153 of global memory but not of escaped memory. */
4154 if (flags & (ECF_CONST|ECF_NOVOPS))
4156 if (gimple_call_lhs (t)
4157 && could_have_pointers (gimple_call_lhs (t)))
4158 handle_const_call (t, &rhsc);
4160 /* Pure functions can return addresses in and of memory
4161 reachable from their arguments, but they are not an escape
4162 point for reachable memory of their arguments. */
4163 else if (flags & (ECF_PURE|ECF_LOOPING_CONST_OR_PURE))
4164 handle_pure_call (t, &rhsc);
4166 handle_rhs_call (t, &rhsc);
4167 if (gimple_call_lhs (t)
4168 && could_have_pointers (gimple_call_lhs (t)))
4169 handle_lhs_call (gimple_call_lhs (t), flags, rhsc, fndecl);
4170 VEC_free (ce_s, heap, rhsc);
4177 fi = get_fi_for_callee (t);
4179 /* Assign all the passed arguments to the appropriate incoming
4180 parameters of the function. */
4181 for (j = 0; j < gimple_call_num_args (t); j++)
4183 struct constraint_expr lhs ;
4184 struct constraint_expr *rhsp;
4185 tree arg = gimple_call_arg (t, j);
4187 if (!could_have_pointers (arg))
4190 get_constraint_for (arg, &rhsc);
4191 lhs = get_function_part_constraint (fi, fi_parm_base + j);
4192 while (VEC_length (ce_s, rhsc) != 0)
4194 rhsp = VEC_last (ce_s, rhsc);
4195 process_constraint (new_constraint (lhs, *rhsp));
4196 VEC_pop (ce_s, rhsc);
4200 /* If we are returning a value, assign it to the result. */
4201 lhsop = gimple_call_lhs (t);
4203 && could_have_pointers (lhsop))
4205 struct constraint_expr rhs;
4206 struct constraint_expr *lhsp;
4208 get_constraint_for (lhsop, &lhsc);
4209 rhs = get_function_part_constraint (fi, fi_result);
4211 && DECL_RESULT (fndecl)
4212 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
4214 VEC(ce_s, heap) *tem = NULL;
4215 VEC_safe_push (ce_s, heap, tem, &rhs);
4217 rhs = *VEC_index (ce_s, tem, 0);
4218 VEC_free(ce_s, heap, tem);
4220 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
4221 process_constraint (new_constraint (*lhsp, rhs));
4224 /* If we pass the result decl by reference, honor that. */
4227 && DECL_RESULT (fndecl)
4228 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
4230 struct constraint_expr lhs;
4231 struct constraint_expr *rhsp;
4233 get_constraint_for_address_of (lhsop, &rhsc);
4234 lhs = get_function_part_constraint (fi, fi_result);
4235 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4236 process_constraint (new_constraint (lhs, *rhsp));
4237 VEC_free (ce_s, heap, rhsc);
4240 /* If we use a static chain, pass it along. */
4241 if (gimple_call_chain (t))
4243 struct constraint_expr lhs;
4244 struct constraint_expr *rhsp;
4246 get_constraint_for (gimple_call_chain (t), &rhsc);
4247 lhs = get_function_part_constraint (fi, fi_static_chain);
4248 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4249 process_constraint (new_constraint (lhs, *rhsp));
4253 /* Otherwise, just a regular assignment statement. Only care about
4254 operations with pointer result, others are dealt with as escape
4255 points if they have pointer operands. */
4256 else if (is_gimple_assign (t)
4257 && could_have_pointers (gimple_assign_lhs (t)))
4259 /* Otherwise, just a regular assignment statement. */
4260 tree lhsop = gimple_assign_lhs (t);
4261 tree rhsop = (gimple_num_ops (t) == 2) ? gimple_assign_rhs1 (t) : NULL;
4263 if (rhsop && AGGREGATE_TYPE_P (TREE_TYPE (lhsop)))
4264 do_structure_copy (lhsop, rhsop);
4267 struct constraint_expr temp;
4268 get_constraint_for (lhsop, &lhsc);
4270 if (gimple_assign_rhs_code (t) == POINTER_PLUS_EXPR)
4271 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
4272 gimple_assign_rhs2 (t), &rhsc);
4273 else if ((CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (t))
4274 && !(POINTER_TYPE_P (gimple_expr_type (t))
4275 && !POINTER_TYPE_P (TREE_TYPE (rhsop))))
4276 || gimple_assign_single_p (t))
4277 get_constraint_for (rhsop, &rhsc);
4280 temp.type = ADDRESSOF;
4281 temp.var = anything_id;
4283 VEC_safe_push (ce_s, heap, rhsc, &temp);
4285 process_all_all_constraints (lhsc, rhsc);
4287 /* If there is a store to a global variable the rhs escapes. */
4288 if ((lhsop = get_base_address (lhsop)) != NULL_TREE
4290 && is_global_var (lhsop)
4292 || DECL_EXTERNAL (lhsop) || TREE_PUBLIC (lhsop)))
4293 make_escape_constraint (rhsop);
4294 /* If this is a conversion of a non-restrict pointer to a
4295 restrict pointer track it with a new heapvar. */
4296 else if (gimple_assign_cast_p (t)
4297 && POINTER_TYPE_P (TREE_TYPE (rhsop))
4298 && POINTER_TYPE_P (TREE_TYPE (lhsop))
4299 && !TYPE_RESTRICT (TREE_TYPE (rhsop))
4300 && TYPE_RESTRICT (TREE_TYPE (lhsop)))
4301 make_constraint_from_restrict (get_vi_for_tree (lhsop),
4304 /* For conversions of pointers to non-pointers the pointer escapes. */
4305 else if (gimple_assign_cast_p (t)
4306 && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (t)))
4307 && !POINTER_TYPE_P (TREE_TYPE (gimple_assign_lhs (t))))
4309 make_escape_constraint (gimple_assign_rhs1 (t));
4311 /* Handle escapes through return. */
4312 else if (gimple_code (t) == GIMPLE_RETURN
4313 && gimple_return_retval (t) != NULL_TREE
4314 && could_have_pointers (gimple_return_retval (t)))
4318 || !(fi = get_vi_for_tree (cfun->decl)))
4319 make_escape_constraint (gimple_return_retval (t));
4320 else if (in_ipa_mode
4323 struct constraint_expr lhs ;
4324 struct constraint_expr *rhsp;
4327 lhs = get_function_part_constraint (fi, fi_result);
4328 get_constraint_for (gimple_return_retval (t), &rhsc);
4329 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4330 process_constraint (new_constraint (lhs, *rhsp));
4333 /* Handle asms conservatively by adding escape constraints to everything. */
4334 else if (gimple_code (t) == GIMPLE_ASM)
4336 unsigned i, noutputs;
4337 const char **oconstraints;
4338 const char *constraint;
4339 bool allows_mem, allows_reg, is_inout;
4341 noutputs = gimple_asm_noutputs (t);
4342 oconstraints = XALLOCAVEC (const char *, noutputs);
4344 for (i = 0; i < noutputs; ++i)
4346 tree link = gimple_asm_output_op (t, i);
4347 tree op = TREE_VALUE (link);
4349 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
4350 oconstraints[i] = constraint;
4351 parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
4352 &allows_reg, &is_inout);
4354 /* A memory constraint makes the address of the operand escape. */
4355 if (!allows_reg && allows_mem)
4356 make_escape_constraint (build_fold_addr_expr (op));
4358 /* The asm may read global memory, so outputs may point to
4359 any global memory. */
4360 if (op && could_have_pointers (op))
4362 VEC(ce_s, heap) *lhsc = NULL;
4363 struct constraint_expr rhsc, *lhsp;
4365 get_constraint_for (op, &lhsc);
4366 rhsc.var = nonlocal_id;
4369 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
4370 process_constraint (new_constraint (*lhsp, rhsc));
4371 VEC_free (ce_s, heap, lhsc);
4374 for (i = 0; i < gimple_asm_ninputs (t); ++i)
4376 tree link = gimple_asm_input_op (t, i);
4377 tree op = TREE_VALUE (link);
4379 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
4381 parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints,
4382 &allows_mem, &allows_reg);
4384 /* A memory constraint makes the address of the operand escape. */
4385 if (!allows_reg && allows_mem)
4386 make_escape_constraint (build_fold_addr_expr (op));
4387 /* Strictly we'd only need the constraint to ESCAPED if
4388 the asm clobbers memory, otherwise using something
4389 along the lines of per-call clobbers/uses would be enough. */
4390 else if (op && could_have_pointers (op))
4391 make_escape_constraint (op);
4395 VEC_free (ce_s, heap, rhsc);
4396 VEC_free (ce_s, heap, lhsc);
4400 /* Create a constraint adding to the clobber set of FI the memory
4401 pointed to by PTR. */
4404 process_ipa_clobber (varinfo_t fi, tree ptr)
4406 VEC(ce_s, heap) *ptrc = NULL;
4407 struct constraint_expr *c, lhs;
4409 get_constraint_for (ptr, &ptrc);
4410 lhs = get_function_part_constraint (fi, fi_clobbers);
4411 for (i = 0; VEC_iterate (ce_s, ptrc, i, c); i++)
4412 process_constraint (new_constraint (lhs, *c));
4413 VEC_free (ce_s, heap, ptrc);
4416 /* Walk statement T setting up clobber and use constraints according to the
4417 references found in T. This function is a main part of the
4418 IPA constraint builder. */
4421 find_func_clobbers (gimple origt)
4424 VEC(ce_s, heap) *lhsc = NULL;
4425 VEC(ce_s, heap) *rhsc = NULL;
4428 /* Add constraints for clobbered/used in IPA mode.
4429 We are not interested in what automatic variables are clobbered
4430 or used as we only use the information in the caller to which
4431 they do not escape. */
4432 gcc_assert (in_ipa_mode);
4434 /* If the stmt refers to memory in any way it better had a VUSE. */
4435 if (gimple_vuse (t) == NULL_TREE)
4438 /* We'd better have function information for the current function. */
4439 fi = lookup_vi_for_tree (cfun->decl);
4440 gcc_assert (fi != NULL);
4442 /* Account for stores in assignments and calls. */
4443 if (gimple_vdef (t) != NULL_TREE
4444 && gimple_has_lhs (t))
4446 tree lhs = gimple_get_lhs (t);
4448 while (handled_component_p (tem))
4449 tem = TREE_OPERAND (tem, 0);
4451 && !auto_var_in_fn_p (tem, cfun->decl))
4452 || INDIRECT_REF_P (tem))
4454 struct constraint_expr lhsc, *rhsp;
4456 lhsc = get_function_part_constraint (fi, fi_clobbers);
4457 get_constraint_for_address_of (lhs, &rhsc);
4458 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4459 process_constraint (new_constraint (lhsc, *rhsp));
4460 VEC_free (ce_s, heap, rhsc);
4464 /* Account for uses in assigments and returns. */
4465 if (gimple_assign_single_p (t)
4466 || (gimple_code (t) == GIMPLE_RETURN
4467 && gimple_return_retval (t) != NULL_TREE))
4469 tree rhs = (gimple_assign_single_p (t)
4470 ? gimple_assign_rhs1 (t) : gimple_return_retval (t));
4472 while (handled_component_p (tem))
4473 tem = TREE_OPERAND (tem, 0);
4475 && !auto_var_in_fn_p (tem, cfun->decl))
4476 || INDIRECT_REF_P (tem))
4478 struct constraint_expr lhs, *rhsp;
4480 lhs = get_function_part_constraint (fi, fi_uses);
4481 get_constraint_for_address_of (rhs, &rhsc);
4482 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4483 process_constraint (new_constraint (lhs, *rhsp));
4484 VEC_free (ce_s, heap, rhsc);
4488 if (is_gimple_call (t))
4490 varinfo_t cfi = NULL;
4491 tree decl = gimple_call_fndecl (t);
4492 struct constraint_expr lhs, rhs;
4495 /* For builtins we do not have separate function info. For those
4496 we do not generate escapes for we have to generate clobbers/uses. */
4498 && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
4499 switch (DECL_FUNCTION_CODE (decl))
4501 /* The following functions use and clobber memory pointed to
4502 by their arguments. */
4503 case BUILT_IN_STRCPY:
4504 case BUILT_IN_STRNCPY:
4505 case BUILT_IN_BCOPY:
4506 case BUILT_IN_MEMCPY:
4507 case BUILT_IN_MEMMOVE:
4508 case BUILT_IN_MEMPCPY:
4509 case BUILT_IN_STPCPY:
4510 case BUILT_IN_STPNCPY:
4511 case BUILT_IN_STRCAT:
4512 case BUILT_IN_STRNCAT:
4514 tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
4515 == BUILT_IN_BCOPY ? 1 : 0));
4516 tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
4517 == BUILT_IN_BCOPY ? 0 : 1));
4519 struct constraint_expr *rhsp, *lhsp;
4520 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4521 lhs = get_function_part_constraint (fi, fi_clobbers);
4522 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); i++)
4523 process_constraint (new_constraint (lhs, *lhsp));
4524 VEC_free (ce_s, heap, lhsc);
4525 get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
4526 lhs = get_function_part_constraint (fi, fi_uses);
4527 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4528 process_constraint (new_constraint (lhs, *rhsp));
4529 VEC_free (ce_s, heap, rhsc);
4532 /* The following function clobbers memory pointed to by
4534 case BUILT_IN_MEMSET:
4536 tree dest = gimple_call_arg (t, 0);
4539 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4540 lhs = get_function_part_constraint (fi, fi_clobbers);
4541 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); i++)
4542 process_constraint (new_constraint (lhs, *lhsp));
4543 VEC_free (ce_s, heap, lhsc);
4546 /* The following functions clobber their second and third
4548 case BUILT_IN_SINCOS:
4549 case BUILT_IN_SINCOSF:
4550 case BUILT_IN_SINCOSL:
4552 process_ipa_clobber (fi, gimple_call_arg (t, 1));
4553 process_ipa_clobber (fi, gimple_call_arg (t, 2));
4556 /* The following functions clobber their second argument. */
4557 case BUILT_IN_FREXP:
4558 case BUILT_IN_FREXPF:
4559 case BUILT_IN_FREXPL:
4560 case BUILT_IN_LGAMMA_R:
4561 case BUILT_IN_LGAMMAF_R:
4562 case BUILT_IN_LGAMMAL_R:
4563 case BUILT_IN_GAMMA_R:
4564 case BUILT_IN_GAMMAF_R:
4565 case BUILT_IN_GAMMAL_R:
4567 case BUILT_IN_MODFF:
4568 case BUILT_IN_MODFL:
4570 process_ipa_clobber (fi, gimple_call_arg (t, 1));
4573 /* The following functions clobber their third argument. */
4574 case BUILT_IN_REMQUO:
4575 case BUILT_IN_REMQUOF:
4576 case BUILT_IN_REMQUOL:
4578 process_ipa_clobber (fi, gimple_call_arg (t, 2));
4581 /* The following functions neither read nor clobber memory. */
4584 /* Trampolines are of no interest to us. */
4585 case BUILT_IN_INIT_TRAMPOLINE:
4586 case BUILT_IN_ADJUST_TRAMPOLINE:
4588 case BUILT_IN_VA_START:
4589 case BUILT_IN_VA_END:
4591 /* printf-style functions may have hooks to set pointers to
4592 point to somewhere into the generated string. Leave them
4593 for a later excercise... */
4595 /* Fallthru to general call handling. */;
4598 /* Parameters passed by value are used. */
4599 lhs = get_function_part_constraint (fi, fi_uses);
4600 for (i = 0; i < gimple_call_num_args (t); i++)
4602 struct constraint_expr *rhsp;
4603 tree arg = gimple_call_arg (t, i);
4605 if (TREE_CODE (arg) == SSA_NAME
4606 || is_gimple_min_invariant (arg))
4609 get_constraint_for_address_of (arg, &rhsc);
4610 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4611 process_constraint (new_constraint (lhs, *rhsp));
4612 VEC_free (ce_s, heap, rhsc);
4615 /* Build constraints for propagating clobbers/uses along the
4617 cfi = get_fi_for_callee (t);
4618 if (cfi->id == anything_id)
4620 if (gimple_vdef (t))
4621 make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
4623 make_constraint_from (first_vi_for_offset (fi, fi_uses),
4628 /* For callees without function info (that's external functions),
4629 ESCAPED is clobbered and used. */
4630 if (gimple_call_fndecl (t)
4631 && !cfi->is_fn_info)
4635 if (gimple_vdef (t))
4636 make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
4638 make_copy_constraint (first_vi_for_offset (fi, fi_uses), escaped_id);
4640 /* Also honor the call statement use/clobber info. */
4641 if ((vi = lookup_call_clobber_vi (t)) != NULL)
4642 make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
4644 if ((vi = lookup_call_use_vi (t)) != NULL)
4645 make_copy_constraint (first_vi_for_offset (fi, fi_uses),
4650 /* Otherwise the caller clobbers and uses what the callee does.
4651 ??? This should use a new complex constraint that filters
4652 local variables of the callee. */
4653 if (gimple_vdef (t))
4655 lhs = get_function_part_constraint (fi, fi_clobbers);
4656 rhs = get_function_part_constraint (cfi, fi_clobbers);
4657 process_constraint (new_constraint (lhs, rhs));
4659 lhs = get_function_part_constraint (fi, fi_uses);
4660 rhs = get_function_part_constraint (cfi, fi_uses);
4661 process_constraint (new_constraint (lhs, rhs));
4663 else if (gimple_code (t) == GIMPLE_ASM)
4665 /* ??? Ick. We can do better. */
4666 if (gimple_vdef (t))
4667 make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
4669 make_constraint_from (first_vi_for_offset (fi, fi_uses),
4673 VEC_free (ce_s, heap, rhsc);
4677 /* Find the first varinfo in the same variable as START that overlaps with
4678 OFFSET. Return NULL if we can't find one. */
4681 first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
4683 /* If the offset is outside of the variable, bail out. */
4684 if (offset >= start->fullsize)
4687 /* If we cannot reach offset from start, lookup the first field
4688 and start from there. */
4689 if (start->offset > offset)
4690 start = lookup_vi_for_tree (start->decl);
4694 /* We may not find a variable in the field list with the actual
4695 offset when when we have glommed a structure to a variable.
4696 In that case, however, offset should still be within the size
4698 if (offset >= start->offset
4699 && (offset - start->offset) < start->size)
4708 /* Find the first varinfo in the same variable as START that overlaps with
4709 OFFSET. If there is no such varinfo the varinfo directly preceding
4710 OFFSET is returned. */
4713 first_or_preceding_vi_for_offset (varinfo_t start,
4714 unsigned HOST_WIDE_INT offset)
4716 /* If we cannot reach offset from start, lookup the first field
4717 and start from there. */
4718 if (start->offset > offset)
4719 start = lookup_vi_for_tree (start->decl);
4721 /* We may not find a variable in the field list with the actual
4722 offset when when we have glommed a structure to a variable.
4723 In that case, however, offset should still be within the size
4725 If we got beyond the offset we look for return the field
4726 directly preceding offset which may be the last field. */
4728 && offset >= start->offset
4729 && !((offset - start->offset) < start->size))
4730 start = start->next;
4736 /* This structure is used during pushing fields onto the fieldstack
4737 to track the offset of the field, since bitpos_of_field gives it
4738 relative to its immediate containing type, and we want it relative
4739 to the ultimate containing object. */
4743 /* Offset from the base of the base containing object to this field. */
4744 HOST_WIDE_INT offset;
4746 /* Size, in bits, of the field. */
4747 unsigned HOST_WIDE_INT size;
4749 unsigned has_unknown_size : 1;
4751 unsigned may_have_pointers : 1;
4753 unsigned only_restrict_pointers : 1;
4755 typedef struct fieldoff fieldoff_s;
4757 DEF_VEC_O(fieldoff_s);
4758 DEF_VEC_ALLOC_O(fieldoff_s,heap);
4760 /* qsort comparison function for two fieldoff's PA and PB */
4763 fieldoff_compare (const void *pa, const void *pb)
4765 const fieldoff_s *foa = (const fieldoff_s *)pa;
4766 const fieldoff_s *fob = (const fieldoff_s *)pb;
4767 unsigned HOST_WIDE_INT foasize, fobsize;
4769 if (foa->offset < fob->offset)
4771 else if (foa->offset > fob->offset)
4774 foasize = foa->size;
4775 fobsize = fob->size;
4776 if (foasize < fobsize)
4778 else if (foasize > fobsize)
4783 /* Sort a fieldstack according to the field offset and sizes. */
4785 sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
4787 qsort (VEC_address (fieldoff_s, fieldstack),
4788 VEC_length (fieldoff_s, fieldstack),
4789 sizeof (fieldoff_s),
4793 /* Return true if V is a tree that we can have subvars for.
4794 Normally, this is any aggregate type. Also complex
4795 types which are not gimple registers can have subvars. */
4798 var_can_have_subvars (const_tree v)
4800 /* Volatile variables should never have subvars. */
4801 if (TREE_THIS_VOLATILE (v))
4804 /* Non decls or memory tags can never have subvars. */
4808 /* Aggregates without overlapping fields can have subvars. */
4809 if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE)
4815 /* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
4816 the fields of TYPE onto fieldstack, recording their offsets along
4819 OFFSET is used to keep track of the offset in this entire
4820 structure, rather than just the immediately containing structure.
4821 Returns false if the caller is supposed to handle the field we
4825 push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
4826 HOST_WIDE_INT offset)
4829 bool empty_p = true;
4831 if (TREE_CODE (type) != RECORD_TYPE)
4834 /* If the vector of fields is growing too big, bail out early.
4835 Callers check for VEC_length <= MAX_FIELDS_FOR_FIELD_SENSITIVE, make
4837 if (VEC_length (fieldoff_s, *fieldstack) > MAX_FIELDS_FOR_FIELD_SENSITIVE)
4840 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4841 if (TREE_CODE (field) == FIELD_DECL)
4844 HOST_WIDE_INT foff = bitpos_of_field (field);
4846 if (!var_can_have_subvars (field)
4847 || TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE
4848 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
4850 else if (!push_fields_onto_fieldstack
4851 (TREE_TYPE (field), fieldstack, offset + foff)
4852 && (DECL_SIZE (field)
4853 && !integer_zerop (DECL_SIZE (field))))
4854 /* Empty structures may have actual size, like in C++. So
4855 see if we didn't push any subfields and the size is
4856 nonzero, push the field onto the stack. */
4861 fieldoff_s *pair = NULL;
4862 bool has_unknown_size = false;
4864 if (!VEC_empty (fieldoff_s, *fieldstack))
4865 pair = VEC_last (fieldoff_s, *fieldstack);
4867 if (!DECL_SIZE (field)
4868 || !host_integerp (DECL_SIZE (field), 1))
4869 has_unknown_size = true;
4871 /* If adjacent fields do not contain pointers merge them. */
4873 && !pair->may_have_pointers
4874 && !pair->has_unknown_size
4875 && !has_unknown_size
4876 && pair->offset + (HOST_WIDE_INT)pair->size == offset + foff
4877 && !could_have_pointers (field))
4879 pair->size += TREE_INT_CST_LOW (DECL_SIZE (field));
4883 pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
4884 pair->offset = offset + foff;
4885 pair->has_unknown_size = has_unknown_size;
4886 if (!has_unknown_size)
4887 pair->size = TREE_INT_CST_LOW (DECL_SIZE (field));
4890 pair->may_have_pointers = could_have_pointers (field);
4891 pair->only_restrict_pointers
4892 = (!has_unknown_size
4893 && POINTER_TYPE_P (TREE_TYPE (field))
4894 && TYPE_RESTRICT (TREE_TYPE (field)));
4904 /* Count the number of arguments DECL has, and set IS_VARARGS to true
4905 if it is a varargs function. */
4908 count_num_arguments (tree decl, bool *is_varargs)
4910 unsigned int num = 0;
4913 /* Capture named arguments for K&R functions. They do not
4914 have a prototype and thus no TYPE_ARG_TYPES. */
4915 for (t = DECL_ARGUMENTS (decl); t; t = TREE_CHAIN (t))
4918 /* Check if the function has variadic arguments. */
4919 for (t = TYPE_ARG_TYPES (TREE_TYPE (decl)); t; t = TREE_CHAIN (t))
4920 if (TREE_VALUE (t) == void_type_node)
4928 /* Creation function node for DECL, using NAME, and return the index
4929 of the variable we've created for the function. */
4932 create_function_info_for (tree decl, const char *name)
4934 struct function *fn = DECL_STRUCT_FUNCTION (decl);
4935 varinfo_t vi, prev_vi;
4938 bool is_varargs = false;
4939 unsigned int num_args = count_num_arguments (decl, &is_varargs);
4941 /* Create the variable info. */
4943 vi = new_var_info (decl, name);
4946 vi->fullsize = fi_parm_base + num_args;
4948 vi->may_have_pointers = false;
4951 insert_vi_for_tree (vi->decl, vi);
4955 /* Create a variable for things the function clobbers and one for
4956 things the function uses. */
4958 varinfo_t clobbervi, usevi;
4959 const char *newname;
4962 asprintf (&tempname, "%s.clobber", name);
4963 newname = ggc_strdup (tempname);
4966 clobbervi = new_var_info (NULL, newname);
4967 clobbervi->offset = fi_clobbers;
4968 clobbervi->size = 1;
4969 clobbervi->fullsize = vi->fullsize;
4970 clobbervi->is_full_var = true;
4971 clobbervi->is_global_var = false;
4972 gcc_assert (prev_vi->offset < clobbervi->offset);
4973 prev_vi->next = clobbervi;
4974 prev_vi = clobbervi;
4976 asprintf (&tempname, "%s.use", name);
4977 newname = ggc_strdup (tempname);
4980 usevi = new_var_info (NULL, newname);
4981 usevi->offset = fi_uses;
4983 usevi->fullsize = vi->fullsize;
4984 usevi->is_full_var = true;
4985 usevi->is_global_var = false;
4986 gcc_assert (prev_vi->offset < usevi->offset);
4987 prev_vi->next = usevi;
4991 /* And one for the static chain. */
4992 if (fn->static_chain_decl != NULL_TREE)
4995 const char *newname;
4998 asprintf (&tempname, "%s.chain", name);
4999 newname = ggc_strdup (tempname);
5002 chainvi = new_var_info (fn->static_chain_decl, newname);
5003 chainvi->offset = fi_static_chain;
5005 chainvi->fullsize = vi->fullsize;
5006 chainvi->is_full_var = true;
5007 chainvi->is_global_var = false;
5008 gcc_assert (prev_vi->offset < chainvi->offset);
5009 prev_vi->next = chainvi;
5011 insert_vi_for_tree (fn->static_chain_decl, chainvi);
5014 /* Create a variable for the return var. */
5015 if (DECL_RESULT (decl) != NULL
5016 || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
5019 const char *newname;
5021 tree resultdecl = decl;
5023 if (DECL_RESULT (decl))
5024 resultdecl = DECL_RESULT (decl);
5026 asprintf (&tempname, "%s.result", name);
5027 newname = ggc_strdup (tempname);
5030 resultvi = new_var_info (resultdecl, newname);
5031 resultvi->offset = fi_result;
5033 resultvi->fullsize = vi->fullsize;
5034 resultvi->is_full_var = true;
5035 if (DECL_RESULT (decl))
5036 resultvi->may_have_pointers = could_have_pointers (DECL_RESULT (decl));
5037 gcc_assert (prev_vi->offset < resultvi->offset);
5038 prev_vi->next = resultvi;
5040 if (DECL_RESULT (decl))
5041 insert_vi_for_tree (DECL_RESULT (decl), resultvi);
5044 /* Set up variables for each argument. */
5045 arg = DECL_ARGUMENTS (decl);
5046 for (i = 0; i < num_args; i++)
5049 const char *newname;
5051 tree argdecl = decl;
5056 asprintf (&tempname, "%s.arg%d", name, i);
5057 newname = ggc_strdup (tempname);
5060 argvi = new_var_info (argdecl, newname);
5061 argvi->offset = fi_parm_base + i;
5063 argvi->is_full_var = true;
5064 argvi->fullsize = vi->fullsize;
5066 argvi->may_have_pointers = could_have_pointers (arg);
5067 gcc_assert (prev_vi->offset < argvi->offset);
5068 prev_vi->next = argvi;
5072 insert_vi_for_tree (arg, argvi);
5073 arg = TREE_CHAIN (arg);
5077 /* Add one representative for all further args. */
5081 const char *newname;
5085 asprintf (&tempname, "%s.varargs", name);
5086 newname = ggc_strdup (tempname);
5089 /* We need sth that can be pointed to for va_start. */
5090 decl = create_tmp_var_raw (ptr_type_node, name);
5093 argvi = new_var_info (decl, newname);
5094 argvi->offset = fi_parm_base + num_args;
5096 argvi->is_full_var = true;
5097 argvi->is_heap_var = true;
5098 argvi->fullsize = vi->fullsize;
5099 gcc_assert (prev_vi->offset < argvi->offset);
5100 prev_vi->next = argvi;
5108 /* Return true if FIELDSTACK contains fields that overlap.
5109 FIELDSTACK is assumed to be sorted by offset. */
5112 check_for_overlaps (VEC (fieldoff_s,heap) *fieldstack)
5114 fieldoff_s *fo = NULL;
5116 HOST_WIDE_INT lastoffset = -1;
5118 for (i = 0; VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
5120 if (fo->offset == lastoffset)
5122 lastoffset = fo->offset;
5127 /* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
5128 This will also create any varinfo structures necessary for fields
5132 create_variable_info_for_1 (tree decl, const char *name)
5134 varinfo_t vi, newvi;
5135 tree decl_type = TREE_TYPE (decl);
5136 tree declsize = DECL_P (decl) ? DECL_SIZE (decl) : TYPE_SIZE (decl_type);
5137 VEC (fieldoff_s,heap) *fieldstack = NULL;
5142 || !host_integerp (declsize, 1))
5144 vi = new_var_info (decl, name);
5148 vi->is_unknown_size_var = true;
5149 vi->is_full_var = true;
5150 vi->may_have_pointers = could_have_pointers (decl);
5154 /* Collect field information. */
5155 if (use_field_sensitive
5156 && var_can_have_subvars (decl)
5157 /* ??? Force us to not use subfields for global initializers
5158 in IPA mode. Else we'd have to parse arbitrary initializers. */
5160 && is_global_var (decl)
5161 && DECL_INITIAL (decl)))
5163 fieldoff_s *fo = NULL;
5164 bool notokay = false;
5167 push_fields_onto_fieldstack (decl_type, &fieldstack, 0);
5169 for (i = 0; !notokay && VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
5170 if (fo->has_unknown_size
5177 /* We can't sort them if we have a field with a variable sized type,
5178 which will make notokay = true. In that case, we are going to return
5179 without creating varinfos for the fields anyway, so sorting them is a
5183 sort_fieldstack (fieldstack);
5184 /* Due to some C++ FE issues, like PR 22488, we might end up
5185 what appear to be overlapping fields even though they,
5186 in reality, do not overlap. Until the C++ FE is fixed,
5187 we will simply disable field-sensitivity for these cases. */
5188 notokay = check_for_overlaps (fieldstack);
5192 VEC_free (fieldoff_s, heap, fieldstack);
5195 /* If we didn't end up collecting sub-variables create a full
5196 variable for the decl. */
5197 if (VEC_length (fieldoff_s, fieldstack) <= 1
5198 || VEC_length (fieldoff_s, fieldstack) > MAX_FIELDS_FOR_FIELD_SENSITIVE)
5200 vi = new_var_info (decl, name);
5202 vi->may_have_pointers = could_have_pointers (decl);
5203 vi->fullsize = TREE_INT_CST_LOW (declsize);
5204 vi->size = vi->fullsize;
5205 vi->is_full_var = true;
5206 VEC_free (fieldoff_s, heap, fieldstack);
5210 vi = new_var_info (decl, name);
5211 vi->fullsize = TREE_INT_CST_LOW (declsize);
5212 for (i = 0, newvi = vi;
5213 VEC_iterate (fieldoff_s, fieldstack, i, fo);
5214 ++i, newvi = newvi->next)
5216 const char *newname = "NULL";
5221 asprintf (&tempname, "%s." HOST_WIDE_INT_PRINT_DEC
5222 "+" HOST_WIDE_INT_PRINT_DEC, name, fo->offset, fo->size);
5223 newname = ggc_strdup (tempname);
5226 newvi->name = newname;
5227 newvi->offset = fo->offset;
5228 newvi->size = fo->size;
5229 newvi->fullsize = vi->fullsize;
5230 newvi->may_have_pointers = fo->may_have_pointers;
5231 newvi->only_restrict_pointers = fo->only_restrict_pointers;
5232 if (i + 1 < VEC_length (fieldoff_s, fieldstack))
5233 newvi->next = new_var_info (decl, name);
5236 VEC_free (fieldoff_s, heap, fieldstack);
5242 create_variable_info_for (tree decl, const char *name)
5244 varinfo_t vi = create_variable_info_for_1 (decl, name);
5245 unsigned int id = vi->id;
5247 insert_vi_for_tree (decl, vi);
5249 /* Create initial constraints for globals. */
5250 for (; vi; vi = vi->next)
5252 if (!vi->may_have_pointers
5253 || !vi->is_global_var)
5256 /* Mark global restrict qualified pointers. */
5257 if ((POINTER_TYPE_P (TREE_TYPE (decl))
5258 && TYPE_RESTRICT (TREE_TYPE (decl)))
5259 || vi->only_restrict_pointers)
5260 make_constraint_from_restrict (vi, "GLOBAL_RESTRICT");
5262 /* For escaped variables initialize them from nonlocal. */
5264 || DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
5265 make_copy_constraint (vi, nonlocal_id);
5267 /* If this is a global variable with an initializer and we are in
5268 IPA mode generate constraints for it. In non-IPA mode
5269 the initializer from nonlocal is all we need. */
5271 && DECL_INITIAL (decl))
5273 VEC (ce_s, heap) *rhsc = NULL;
5274 struct constraint_expr lhs, *rhsp;
5276 get_constraint_for (DECL_INITIAL (decl), &rhsc);
5280 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
5281 process_constraint (new_constraint (lhs, *rhsp));
5282 /* If this is a variable that escapes from the unit
5283 the initializer escapes as well. */
5284 if (DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
5286 lhs.var = escaped_id;
5289 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
5290 process_constraint (new_constraint (lhs, *rhsp));
5292 VEC_free (ce_s, heap, rhsc);
5299 /* Print out the points-to solution for VAR to FILE. */
5302 dump_solution_for_var (FILE *file, unsigned int var)
5304 varinfo_t vi = get_varinfo (var);
5308 /* Dump the solution for unified vars anyway, this avoids difficulties
5309 in scanning dumps in the testsuite. */
5310 fprintf (file, "%s = { ", vi->name);
5311 vi = get_varinfo (find (var));
5312 EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
5313 fprintf (file, "%s ", get_varinfo (i)->name);
5314 fprintf (file, "}");
5316 /* But note when the variable was unified. */
5318 fprintf (file, " same as %s", vi->name);
5320 fprintf (file, "\n");
5323 /* Print the points-to solution for VAR to stdout. */
5326 debug_solution_for_var (unsigned int var)
5328 dump_solution_for_var (stdout, var);
5331 /* Create varinfo structures for all of the variables in the
5332 function for intraprocedural mode. */
5335 intra_create_variable_infos (void)
5339 /* For each incoming pointer argument arg, create the constraint ARG
5340 = NONLOCAL or a dummy variable if it is a restrict qualified
5341 passed-by-reference argument. */
5342 for (t = DECL_ARGUMENTS (current_function_decl); t; t = TREE_CHAIN (t))
5346 if (!could_have_pointers (t))
5349 /* For restrict qualified pointers to objects passed by
5350 reference build a real representative for the pointed-to object. */
5351 if (DECL_BY_REFERENCE (t)
5352 && POINTER_TYPE_P (TREE_TYPE (t))
5353 && TYPE_RESTRICT (TREE_TYPE (t)))
5355 struct constraint_expr lhsc, rhsc;
5357 tree heapvar = heapvar_lookup (t, 0);
5358 if (heapvar == NULL_TREE)
5361 heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)),
5363 DECL_EXTERNAL (heapvar) = 1;
5364 heapvar_insert (t, 0, heapvar);
5365 ann = get_var_ann (heapvar);
5366 ann->is_heapvar = 1;
5368 if (gimple_referenced_vars (cfun))
5369 add_referenced_var (heapvar);
5370 lhsc.var = get_vi_for_tree (t)->id;
5373 rhsc.var = (vi = get_vi_for_tree (heapvar))->id;
5374 rhsc.type = ADDRESSOF;
5376 process_constraint (new_constraint (lhsc, rhsc));
5377 vi->is_restrict_var = 1;
5381 for (p = get_vi_for_tree (t); p; p = p->next)
5383 if (p->may_have_pointers)
5384 make_constraint_from (p, nonlocal_id);
5385 if (p->only_restrict_pointers)
5386 make_constraint_from_restrict (p, "PARM_RESTRICT");
5388 if (POINTER_TYPE_P (TREE_TYPE (t))
5389 && TYPE_RESTRICT (TREE_TYPE (t)))
5390 make_constraint_from_restrict (get_vi_for_tree (t), "PARM_RESTRICT");
5393 /* Add a constraint for a result decl that is passed by reference. */
5394 if (DECL_RESULT (cfun->decl)
5395 && DECL_BY_REFERENCE (DECL_RESULT (cfun->decl)))
5397 varinfo_t p, result_vi = get_vi_for_tree (DECL_RESULT (cfun->decl));
5399 for (p = result_vi; p; p = p->next)
5400 make_constraint_from (p, nonlocal_id);
5403 /* Add a constraint for the incoming static chain parameter. */
5404 if (cfun->static_chain_decl != NULL_TREE)
5406 varinfo_t p, chain_vi = get_vi_for_tree (cfun->static_chain_decl);
5408 for (p = chain_vi; p; p = p->next)
5409 make_constraint_from (p, nonlocal_id);
5413 /* Structure used to put solution bitmaps in a hashtable so they can
5414 be shared among variables with the same points-to set. */
5416 typedef struct shared_bitmap_info
5420 } *shared_bitmap_info_t;
5421 typedef const struct shared_bitmap_info *const_shared_bitmap_info_t;
5423 static htab_t shared_bitmap_table;
5425 /* Hash function for a shared_bitmap_info_t */
5428 shared_bitmap_hash (const void *p)
5430 const_shared_bitmap_info_t const bi = (const_shared_bitmap_info_t) p;
5431 return bi->hashcode;
5434 /* Equality function for two shared_bitmap_info_t's. */
5437 shared_bitmap_eq (const void *p1, const void *p2)
5439 const_shared_bitmap_info_t const sbi1 = (const_shared_bitmap_info_t) p1;
5440 const_shared_bitmap_info_t const sbi2 = (const_shared_bitmap_info_t) p2;
5441 return bitmap_equal_p (sbi1->pt_vars, sbi2->pt_vars);
5444 /* Lookup a bitmap in the shared bitmap hashtable, and return an already
5445 existing instance if there is one, NULL otherwise. */
5448 shared_bitmap_lookup (bitmap pt_vars)
5451 struct shared_bitmap_info sbi;
5453 sbi.pt_vars = pt_vars;
5454 sbi.hashcode = bitmap_hash (pt_vars);
5456 slot = htab_find_slot_with_hash (shared_bitmap_table, &sbi,
5457 sbi.hashcode, NO_INSERT);
5461 return ((shared_bitmap_info_t) *slot)->pt_vars;
5465 /* Add a bitmap to the shared bitmap hashtable. */
5468 shared_bitmap_add (bitmap pt_vars)
5471 shared_bitmap_info_t sbi = XNEW (struct shared_bitmap_info);
5473 sbi->pt_vars = pt_vars;
5474 sbi->hashcode = bitmap_hash (pt_vars);
5476 slot = htab_find_slot_with_hash (shared_bitmap_table, sbi,
5477 sbi->hashcode, INSERT);
5478 gcc_assert (!*slot);
5479 *slot = (void *) sbi;
5483 /* Set bits in INTO corresponding to the variable uids in solution set FROM. */
5486 set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt)
5491 EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
5493 varinfo_t vi = get_varinfo (i);
5495 /* The only artificial variables that are allowed in a may-alias
5496 set are heap variables. */
5497 if (vi->is_artificial_var && !vi->is_heap_var)
5500 if (TREE_CODE (vi->decl) == VAR_DECL
5501 || TREE_CODE (vi->decl) == PARM_DECL
5502 || TREE_CODE (vi->decl) == RESULT_DECL)
5504 /* If we are in IPA mode we will not recompute points-to
5505 sets after inlining so make sure they stay valid. */
5507 && !DECL_PT_UID_SET_P (vi->decl))
5508 SET_DECL_PT_UID (vi->decl, DECL_UID (vi->decl));
5510 /* Add the decl to the points-to set. Note that the points-to
5511 set contains global variables. */
5512 bitmap_set_bit (into, DECL_PT_UID (vi->decl));
5513 if (vi->is_global_var)
5514 pt->vars_contains_global = true;
5520 /* Compute the points-to solution *PT for the variable VI. */
5523 find_what_var_points_to (varinfo_t orig_vi, struct pt_solution *pt)
5527 bitmap finished_solution;
5531 memset (pt, 0, sizeof (struct pt_solution));
5533 /* This variable may have been collapsed, let's get the real
5535 vi = get_varinfo (find (orig_vi->id));
5537 /* Translate artificial variables into SSA_NAME_PTR_INFO
5539 EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
5541 varinfo_t vi = get_varinfo (i);
5543 if (vi->is_artificial_var)
5545 if (vi->id == nothing_id)
5547 else if (vi->id == escaped_id)
5550 pt->ipa_escaped = 1;
5554 else if (vi->id == nonlocal_id)
5556 else if (vi->is_heap_var)
5557 /* We represent heapvars in the points-to set properly. */
5559 else if (vi->id == readonly_id)
5562 else if (vi->id == anything_id
5563 || vi->id == integer_id)
5566 if (vi->is_restrict_var)
5567 pt->vars_contains_restrict = true;
5570 /* Instead of doing extra work, simply do not create
5571 elaborate points-to information for pt_anything pointers. */
5573 && (orig_vi->is_artificial_var
5574 || !pt->vars_contains_restrict))
5577 /* Share the final set of variables when possible. */
5578 finished_solution = BITMAP_GGC_ALLOC ();
5579 stats.points_to_sets_created++;
5581 set_uids_in_ptset (finished_solution, vi->solution, pt);
5582 result = shared_bitmap_lookup (finished_solution);
5585 shared_bitmap_add (finished_solution);
5586 pt->vars = finished_solution;
5591 bitmap_clear (finished_solution);
5595 /* Given a pointer variable P, fill in its points-to set. */
5598 find_what_p_points_to (tree p)
5600 struct ptr_info_def *pi;
5604 /* For parameters, get at the points-to set for the actual parm
5606 if (TREE_CODE (p) == SSA_NAME
5607 && TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL
5608 && SSA_NAME_IS_DEFAULT_DEF (p))
5609 lookup_p = SSA_NAME_VAR (p);
5611 vi = lookup_vi_for_tree (lookup_p);
5615 pi = get_ptr_info (p);
5616 find_what_var_points_to (vi, &pi->pt);
5620 /* Query statistics for points-to solutions. */
5623 unsigned HOST_WIDE_INT pt_solution_includes_may_alias;
5624 unsigned HOST_WIDE_INT pt_solution_includes_no_alias;
5625 unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias;
5626 unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias;
5630 dump_pta_stats (FILE *s)
5632 fprintf (s, "\nPTA query stats:\n");
5633 fprintf (s, " pt_solution_includes: "
5634 HOST_WIDE_INT_PRINT_DEC" disambiguations, "
5635 HOST_WIDE_INT_PRINT_DEC" queries\n",
5636 pta_stats.pt_solution_includes_no_alias,
5637 pta_stats.pt_solution_includes_no_alias
5638 + pta_stats.pt_solution_includes_may_alias);
5639 fprintf (s, " pt_solutions_intersect: "
5640 HOST_WIDE_INT_PRINT_DEC" disambiguations, "
5641 HOST_WIDE_INT_PRINT_DEC" queries\n",
5642 pta_stats.pt_solutions_intersect_no_alias,
5643 pta_stats.pt_solutions_intersect_no_alias
5644 + pta_stats.pt_solutions_intersect_may_alias);
5648 /* Reset the points-to solution *PT to a conservative default
5649 (point to anything). */
5652 pt_solution_reset (struct pt_solution *pt)
5654 memset (pt, 0, sizeof (struct pt_solution));
5655 pt->anything = true;
5658 /* Set the points-to solution *PT to point only to the variables
5659 in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
5660 global variables and VARS_CONTAINS_RESTRICT specifies whether
5661 it contains restrict tag variables. */
5664 pt_solution_set (struct pt_solution *pt, bitmap vars,
5665 bool vars_contains_global, bool vars_contains_restrict)
5667 memset (pt, 0, sizeof (struct pt_solution));
5669 pt->vars_contains_global = vars_contains_global;
5670 pt->vars_contains_restrict = vars_contains_restrict;
5673 /* Computes the union of the points-to solutions *DEST and *SRC and
5674 stores the result in *DEST. This changes the points-to bitmap
5675 of *DEST and thus may not be used if that might be shared.
5676 The points-to bitmap of *SRC and *DEST will not be shared after
5677 this function if they were not before. */
5680 pt_solution_ior_into (struct pt_solution *dest, struct pt_solution *src)
5682 dest->anything |= src->anything;
5685 pt_solution_reset (dest);
5689 dest->nonlocal |= src->nonlocal;
5690 dest->escaped |= src->escaped;
5691 dest->ipa_escaped |= src->ipa_escaped;
5692 dest->null |= src->null;
5693 dest->vars_contains_global |= src->vars_contains_global;
5694 dest->vars_contains_restrict |= src->vars_contains_restrict;
5699 dest->vars = BITMAP_GGC_ALLOC ();
5700 bitmap_ior_into (dest->vars, src->vars);
5703 /* Return true if the points-to solution *PT is empty. */
5706 pt_solution_empty_p (struct pt_solution *pt)
5713 && !bitmap_empty_p (pt->vars))
5716 /* If the solution includes ESCAPED, check if that is empty. */
5718 && !pt_solution_empty_p (&cfun->gimple_df->escaped))
5721 /* If the solution includes ESCAPED, check if that is empty. */
5723 && !pt_solution_empty_p (&ipa_escaped_pt))
5729 /* Return true if the points-to solution *PT includes global memory. */
5732 pt_solution_includes_global (struct pt_solution *pt)
5736 || pt->vars_contains_global)
5740 return pt_solution_includes_global (&cfun->gimple_df->escaped);
5742 if (pt->ipa_escaped)
5743 return pt_solution_includes_global (&ipa_escaped_pt);
5745 /* ??? This predicate is not correct for the IPA-PTA solution
5746 as we do not properly distinguish between unit escape points
5747 and global variables. */
5748 if (cfun->gimple_df->ipa_pta)
5754 /* Return true if the points-to solution *PT includes the variable
5755 declaration DECL. */
5758 pt_solution_includes_1 (struct pt_solution *pt, const_tree decl)
5764 && is_global_var (decl))
5768 && bitmap_bit_p (pt->vars, DECL_PT_UID (decl)))
5771 /* If the solution includes ESCAPED, check it. */
5773 && pt_solution_includes_1 (&cfun->gimple_df->escaped, decl))
5776 /* If the solution includes ESCAPED, check it. */
5778 && pt_solution_includes_1 (&ipa_escaped_pt, decl))
5785 pt_solution_includes (struct pt_solution *pt, const_tree decl)
5787 bool res = pt_solution_includes_1 (pt, decl);
5789 ++pta_stats.pt_solution_includes_may_alias;
5791 ++pta_stats.pt_solution_includes_no_alias;
5795 /* Return true if both points-to solutions PT1 and PT2 have a non-empty
5799 pt_solutions_intersect_1 (struct pt_solution *pt1, struct pt_solution *pt2)
5801 if (pt1->anything || pt2->anything)
5804 /* If either points to unknown global memory and the other points to
5805 any global memory they alias. */
5808 || pt2->vars_contains_global))
5810 && pt1->vars_contains_global))
5813 /* Check the escaped solution if required. */
5814 if ((pt1->escaped || pt2->escaped)
5815 && !pt_solution_empty_p (&cfun->gimple_df->escaped))
5817 /* If both point to escaped memory and that solution
5818 is not empty they alias. */
5819 if (pt1->escaped && pt2->escaped)
5822 /* If either points to escaped memory see if the escaped solution
5823 intersects with the other. */
5825 && pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt2))
5827 && pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt1)))
5831 /* Check the escaped solution if required.
5832 ??? Do we need to check the local against the IPA escaped sets? */
5833 if ((pt1->ipa_escaped || pt2->ipa_escaped)
5834 && !pt_solution_empty_p (&ipa_escaped_pt))
5836 /* If both point to escaped memory and that solution
5837 is not empty they alias. */
5838 if (pt1->ipa_escaped && pt2->ipa_escaped)
5841 /* If either points to escaped memory see if the escaped solution
5842 intersects with the other. */
5843 if ((pt1->ipa_escaped
5844 && pt_solutions_intersect_1 (&ipa_escaped_pt, pt2))
5845 || (pt2->ipa_escaped
5846 && pt_solutions_intersect_1 (&ipa_escaped_pt, pt1)))
5850 /* Now both pointers alias if their points-to solution intersects. */
5853 && bitmap_intersect_p (pt1->vars, pt2->vars));
5857 pt_solutions_intersect (struct pt_solution *pt1, struct pt_solution *pt2)
5859 bool res = pt_solutions_intersect_1 (pt1, pt2);
5861 ++pta_stats.pt_solutions_intersect_may_alias;
5863 ++pta_stats.pt_solutions_intersect_no_alias;
5867 /* Return true if both points-to solutions PT1 and PT2 for two restrict
5868 qualified pointers are possibly based on the same pointer. */
5871 pt_solutions_same_restrict_base (struct pt_solution *pt1,
5872 struct pt_solution *pt2)
5874 /* If we deal with points-to solutions of two restrict qualified
5875 pointers solely rely on the pointed-to variable bitmap intersection.
5876 For two pointers that are based on each other the bitmaps will
5878 if (pt1->vars_contains_restrict
5879 && pt2->vars_contains_restrict)
5881 gcc_assert (pt1->vars && pt2->vars);
5882 return bitmap_intersect_p (pt1->vars, pt2->vars);
5889 /* Dump points-to information to OUTFILE. */
5892 dump_sa_points_to_info (FILE *outfile)
5896 fprintf (outfile, "\nPoints-to sets\n\n");
5898 if (dump_flags & TDF_STATS)
5900 fprintf (outfile, "Stats:\n");
5901 fprintf (outfile, "Total vars: %d\n", stats.total_vars);
5902 fprintf (outfile, "Non-pointer vars: %d\n",
5903 stats.nonpointer_vars);
5904 fprintf (outfile, "Statically unified vars: %d\n",
5905 stats.unified_vars_static);
5906 fprintf (outfile, "Dynamically unified vars: %d\n",
5907 stats.unified_vars_dynamic);
5908 fprintf (outfile, "Iterations: %d\n", stats.iterations);
5909 fprintf (outfile, "Number of edges: %d\n", stats.num_edges);
5910 fprintf (outfile, "Number of implicit edges: %d\n",
5911 stats.num_implicit_edges);
5914 for (i = 0; i < VEC_length (varinfo_t, varmap); i++)
5916 varinfo_t vi = get_varinfo (i);
5917 if (!vi->may_have_pointers)
5919 dump_solution_for_var (outfile, i);
5924 /* Debug points-to information to stderr. */
5927 debug_sa_points_to_info (void)
5929 dump_sa_points_to_info (stderr);
5933 /* Initialize the always-existing constraint variables for NULL
5934 ANYTHING, READONLY, and INTEGER */
5937 init_base_vars (void)
5939 struct constraint_expr lhs, rhs;
5940 varinfo_t var_anything;
5941 varinfo_t var_nothing;
5942 varinfo_t var_readonly;
5943 varinfo_t var_escaped;
5944 varinfo_t var_nonlocal;
5945 varinfo_t var_storedanything;
5946 varinfo_t var_integer;
5948 /* Create the NULL variable, used to represent that a variable points
5950 var_nothing = new_var_info (NULL_TREE, "NULL");
5951 gcc_assert (var_nothing->id == nothing_id);
5952 var_nothing->is_artificial_var = 1;
5953 var_nothing->offset = 0;
5954 var_nothing->size = ~0;
5955 var_nothing->fullsize = ~0;
5956 var_nothing->is_special_var = 1;
5957 var_nothing->may_have_pointers = 0;
5958 var_nothing->is_global_var = 0;
5960 /* Create the ANYTHING variable, used to represent that a variable
5961 points to some unknown piece of memory. */
5962 var_anything = new_var_info (NULL_TREE, "ANYTHING");
5963 gcc_assert (var_anything->id == anything_id);
5964 var_anything->is_artificial_var = 1;
5965 var_anything->size = ~0;
5966 var_anything->offset = 0;
5967 var_anything->next = NULL;
5968 var_anything->fullsize = ~0;
5969 var_anything->is_special_var = 1;
5971 /* Anything points to anything. This makes deref constraints just
5972 work in the presence of linked list and other p = *p type loops,
5973 by saying that *ANYTHING = ANYTHING. */
5975 lhs.var = anything_id;
5977 rhs.type = ADDRESSOF;
5978 rhs.var = anything_id;
5981 /* This specifically does not use process_constraint because
5982 process_constraint ignores all anything = anything constraints, since all
5983 but this one are redundant. */
5984 VEC_safe_push (constraint_t, heap, constraints, new_constraint (lhs, rhs));
5986 /* Create the READONLY variable, used to represent that a variable
5987 points to readonly memory. */
5988 var_readonly = new_var_info (NULL_TREE, "READONLY");
5989 gcc_assert (var_readonly->id == readonly_id);
5990 var_readonly->is_artificial_var = 1;
5991 var_readonly->offset = 0;
5992 var_readonly->size = ~0;
5993 var_readonly->fullsize = ~0;
5994 var_readonly->next = NULL;
5995 var_readonly->is_special_var = 1;
5997 /* readonly memory points to anything, in order to make deref
5998 easier. In reality, it points to anything the particular
5999 readonly variable can point to, but we don't track this
6002 lhs.var = readonly_id;
6004 rhs.type = ADDRESSOF;
6005 rhs.var = readonly_id; /* FIXME */
6007 process_constraint (new_constraint (lhs, rhs));
6009 /* Create the ESCAPED variable, used to represent the set of escaped
6011 var_escaped = new_var_info (NULL_TREE, "ESCAPED");
6012 gcc_assert (var_escaped->id == escaped_id);
6013 var_escaped->is_artificial_var = 1;
6014 var_escaped->offset = 0;
6015 var_escaped->size = ~0;
6016 var_escaped->fullsize = ~0;
6017 var_escaped->is_special_var = 0;
6019 /* Create the NONLOCAL variable, used to represent the set of nonlocal
6021 var_nonlocal = new_var_info (NULL_TREE, "NONLOCAL");
6022 gcc_assert (var_nonlocal->id == nonlocal_id);
6023 var_nonlocal->is_artificial_var = 1;
6024 var_nonlocal->offset = 0;
6025 var_nonlocal->size = ~0;
6026 var_nonlocal->fullsize = ~0;
6027 var_nonlocal->is_special_var = 1;
6029 /* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
6031 lhs.var = escaped_id;
6034 rhs.var = escaped_id;
6036 process_constraint (new_constraint (lhs, rhs));
6038 /* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
6039 whole variable escapes. */
6041 lhs.var = escaped_id;
6044 rhs.var = escaped_id;
6045 rhs.offset = UNKNOWN_OFFSET;
6046 process_constraint (new_constraint (lhs, rhs));
6048 /* *ESCAPED = NONLOCAL. This is true because we have to assume
6049 everything pointed to by escaped points to what global memory can
6052 lhs.var = escaped_id;
6055 rhs.var = nonlocal_id;
6057 process_constraint (new_constraint (lhs, rhs));
6059 /* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
6060 global memory may point to global memory and escaped memory. */
6062 lhs.var = nonlocal_id;
6064 rhs.type = ADDRESSOF;
6065 rhs.var = nonlocal_id;
6067 process_constraint (new_constraint (lhs, rhs));
6068 rhs.type = ADDRESSOF;
6069 rhs.var = escaped_id;
6071 process_constraint (new_constraint (lhs, rhs));
6073 /* Create the STOREDANYTHING variable, used to represent the set of
6074 variables stored to *ANYTHING. */
6075 var_storedanything = new_var_info (NULL_TREE, "STOREDANYTHING");
6076 gcc_assert (var_storedanything->id == storedanything_id);
6077 var_storedanything->is_artificial_var = 1;
6078 var_storedanything->offset = 0;
6079 var_storedanything->size = ~0;
6080 var_storedanything->fullsize = ~0;
6081 var_storedanything->is_special_var = 0;
6083 /* Create the INTEGER variable, used to represent that a variable points
6084 to what an INTEGER "points to". */
6085 var_integer = new_var_info (NULL_TREE, "INTEGER");
6086 gcc_assert (var_integer->id == integer_id);
6087 var_integer->is_artificial_var = 1;
6088 var_integer->size = ~0;
6089 var_integer->fullsize = ~0;
6090 var_integer->offset = 0;
6091 var_integer->next = NULL;
6092 var_integer->is_special_var = 1;
6094 /* INTEGER = ANYTHING, because we don't know where a dereference of
6095 a random integer will point to. */
6097 lhs.var = integer_id;
6099 rhs.type = ADDRESSOF;
6100 rhs.var = anything_id;
6102 process_constraint (new_constraint (lhs, rhs));
6105 /* Initialize things necessary to perform PTA */
6108 init_alias_vars (void)
6110 use_field_sensitive = (MAX_FIELDS_FOR_FIELD_SENSITIVE > 1);
6112 bitmap_obstack_initialize (&pta_obstack);
6113 bitmap_obstack_initialize (&oldpta_obstack);
6114 bitmap_obstack_initialize (&predbitmap_obstack);
6116 constraint_pool = create_alloc_pool ("Constraint pool",
6117 sizeof (struct constraint), 30);
6118 variable_info_pool = create_alloc_pool ("Variable info pool",
6119 sizeof (struct variable_info), 30);
6120 constraints = VEC_alloc (constraint_t, heap, 8);
6121 varmap = VEC_alloc (varinfo_t, heap, 8);
6122 vi_for_tree = pointer_map_create ();
6123 call_stmt_vars = pointer_map_create ();
6125 memset (&stats, 0, sizeof (stats));
6126 shared_bitmap_table = htab_create (511, shared_bitmap_hash,
6127 shared_bitmap_eq, free);
6131 /* Remove the REF and ADDRESS edges from GRAPH, as well as all the
6132 predecessor edges. */
6135 remove_preds_and_fake_succs (constraint_graph_t graph)
6139 /* Clear the implicit ref and address nodes from the successor
6141 for (i = 0; i < FIRST_REF_NODE; i++)
6143 if (graph->succs[i])
6144 bitmap_clear_range (graph->succs[i], FIRST_REF_NODE,
6145 FIRST_REF_NODE * 2);
6148 /* Free the successor list for the non-ref nodes. */
6149 for (i = FIRST_REF_NODE; i < graph->size; i++)
6151 if (graph->succs[i])
6152 BITMAP_FREE (graph->succs[i]);
6155 /* Now reallocate the size of the successor list as, and blow away
6156 the predecessor bitmaps. */
6157 graph->size = VEC_length (varinfo_t, varmap);
6158 graph->succs = XRESIZEVEC (bitmap, graph->succs, graph->size);
6160 free (graph->implicit_preds);
6161 graph->implicit_preds = NULL;
6162 free (graph->preds);
6163 graph->preds = NULL;
6164 bitmap_obstack_release (&predbitmap_obstack);
6167 /* Initialize the heapvar for statement mapping. */
6170 init_alias_heapvars (void)
6172 if (!heapvar_for_stmt)
6173 heapvar_for_stmt = htab_create_ggc (11, tree_map_hash, heapvar_map_eq,
6177 /* Delete the heapvar for statement mapping. */
6180 delete_alias_heapvars (void)
6182 if (heapvar_for_stmt)
6183 htab_delete (heapvar_for_stmt);
6184 heapvar_for_stmt = NULL;
6187 /* Solve the constraint set. */
6190 solve_constraints (void)
6192 struct scc_info *si;
6196 "\nCollapsing static cycles and doing variable "
6199 init_graph (VEC_length (varinfo_t, varmap) * 2);
6202 fprintf (dump_file, "Building predecessor graph\n");
6203 build_pred_graph ();
6206 fprintf (dump_file, "Detecting pointer and location "
6208 si = perform_var_substitution (graph);
6211 fprintf (dump_file, "Rewriting constraints and unifying "
6213 rewrite_constraints (graph, si);
6215 build_succ_graph ();
6216 free_var_substitution_info (si);
6218 if (dump_file && (dump_flags & TDF_GRAPH))
6219 dump_constraint_graph (dump_file);
6221 move_complex_constraints (graph);
6224 fprintf (dump_file, "Uniting pointer but not location equivalent "
6226 unite_pointer_equivalences (graph);
6229 fprintf (dump_file, "Finding indirect cycles\n");
6230 find_indirect_cycles (graph);
6232 /* Implicit nodes and predecessors are no longer necessary at this
6234 remove_preds_and_fake_succs (graph);
6237 fprintf (dump_file, "Solving graph\n");
6239 solve_graph (graph);
6242 dump_sa_points_to_info (dump_file);
6245 /* Create points-to sets for the current function. See the comments
6246 at the start of the file for an algorithmic overview. */
6249 compute_points_to_sets (void)
6255 timevar_push (TV_TREE_PTA);
6258 init_alias_heapvars ();
6260 intra_create_variable_infos ();
6262 /* Now walk all statements and build the constraint set. */
6265 gimple_stmt_iterator gsi;
6267 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6269 gimple phi = gsi_stmt (gsi);
6271 if (is_gimple_reg (gimple_phi_result (phi)))
6272 find_func_aliases (phi);
6275 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6277 gimple stmt = gsi_stmt (gsi);
6279 find_func_aliases (stmt);
6285 fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
6286 dump_constraints (dump_file, 0);
6289 /* From the constraints compute the points-to sets. */
6290 solve_constraints ();
6292 /* Compute the points-to set for ESCAPED used for call-clobber analysis. */
6293 find_what_var_points_to (get_varinfo (escaped_id),
6294 &cfun->gimple_df->escaped);
6296 /* Make sure the ESCAPED solution (which is used as placeholder in
6297 other solutions) does not reference itself. This simplifies
6298 points-to solution queries. */
6299 cfun->gimple_df->escaped.escaped = 0;
6301 /* Mark escaped HEAP variables as global. */
6302 for (i = 0; VEC_iterate (varinfo_t, varmap, i, vi); ++i)
6304 && !vi->is_restrict_var
6305 && !vi->is_global_var)
6306 DECL_EXTERNAL (vi->decl) = vi->is_global_var
6307 = pt_solution_includes (&cfun->gimple_df->escaped, vi->decl);
6309 /* Compute the points-to sets for pointer SSA_NAMEs. */
6310 for (i = 0; i < num_ssa_names; ++i)
6312 tree ptr = ssa_name (i);
6314 && POINTER_TYPE_P (TREE_TYPE (ptr)))
6315 find_what_p_points_to (ptr);
6318 /* Compute the call-used/clobbered sets. */
6321 gimple_stmt_iterator gsi;
6323 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6325 gimple stmt = gsi_stmt (gsi);
6326 struct pt_solution *pt;
6327 if (!is_gimple_call (stmt))
6330 pt = gimple_call_use_set (stmt);
6331 if (gimple_call_flags (stmt) & ECF_CONST)
6332 memset (pt, 0, sizeof (struct pt_solution));
6333 else if ((vi = lookup_call_use_vi (stmt)) != NULL)
6335 find_what_var_points_to (vi, pt);
6336 /* Escaped (and thus nonlocal) variables are always
6337 implicitly used by calls. */
6338 /* ??? ESCAPED can be empty even though NONLOCAL
6345 /* If there is nothing special about this call then
6346 we have made everything that is used also escape. */
6347 *pt = cfun->gimple_df->escaped;
6351 pt = gimple_call_clobber_set (stmt);
6352 if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
6353 memset (pt, 0, sizeof (struct pt_solution));
6354 else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
6356 find_what_var_points_to (vi, pt);
6357 /* Escaped (and thus nonlocal) variables are always
6358 implicitly clobbered by calls. */
6359 /* ??? ESCAPED can be empty even though NONLOCAL
6366 /* If there is nothing special about this call then
6367 we have made everything that is used also escape. */
6368 *pt = cfun->gimple_df->escaped;
6374 timevar_pop (TV_TREE_PTA);
6378 /* Delete created points-to sets. */
6381 delete_points_to_sets (void)
6385 htab_delete (shared_bitmap_table);
6386 if (dump_file && (dump_flags & TDF_STATS))
6387 fprintf (dump_file, "Points to sets created:%d\n",
6388 stats.points_to_sets_created);
6390 pointer_map_destroy (vi_for_tree);
6391 pointer_map_destroy (call_stmt_vars);
6392 bitmap_obstack_release (&pta_obstack);
6393 VEC_free (constraint_t, heap, constraints);
6395 for (i = 0; i < graph->size; i++)
6396 VEC_free (constraint_t, heap, graph->complex[i]);
6397 free (graph->complex);
6400 free (graph->succs);
6402 free (graph->pe_rep);
6403 free (graph->indirect_cycles);
6406 VEC_free (varinfo_t, heap, varmap);
6407 free_alloc_pool (variable_info_pool);
6408 free_alloc_pool (constraint_pool);
6412 /* Compute points-to information for every SSA_NAME pointer in the
6413 current function and compute the transitive closure of escaped
6414 variables to re-initialize the call-clobber states of local variables. */
6417 compute_may_aliases (void)
6419 if (cfun->gimple_df->ipa_pta)
6423 fprintf (dump_file, "\nNot re-computing points-to information "
6424 "because IPA points-to information is available.\n\n");
6426 /* But still dump what we have remaining it. */
6427 dump_alias_info (dump_file);
6429 if (dump_flags & TDF_DETAILS)
6430 dump_referenced_vars (dump_file);
6436 /* For each pointer P_i, determine the sets of variables that P_i may
6437 point-to. Compute the reachability set of escaped and call-used
6439 compute_points_to_sets ();
6441 /* Debugging dumps. */
6444 dump_alias_info (dump_file);
6446 if (dump_flags & TDF_DETAILS)
6447 dump_referenced_vars (dump_file);
6450 /* Deallocate memory used by aliasing data structures and the internal
6451 points-to solution. */
6452 delete_points_to_sets ();
6454 gcc_assert (!need_ssa_update_p (cfun));
6460 gate_tree_pta (void)
6462 return flag_tree_pta;
6465 /* A dummy pass to cause points-to information to be computed via
6466 TODO_rebuild_alias. */
6468 struct gimple_opt_pass pass_build_alias =
6473 gate_tree_pta, /* gate */
6477 0, /* static_pass_number */
6478 TV_NONE, /* tv_id */
6479 PROP_cfg | PROP_ssa, /* properties_required */
6480 0, /* properties_provided */
6481 0, /* properties_destroyed */
6482 0, /* todo_flags_start */
6483 TODO_rebuild_alias | TODO_dump_func /* todo_flags_finish */
6487 /* A dummy pass to cause points-to information to be computed via
6488 TODO_rebuild_alias. */
6490 struct gimple_opt_pass pass_build_ealias =
6494 "ealias", /* name */
6495 gate_tree_pta, /* gate */
6499 0, /* static_pass_number */
6500 TV_NONE, /* tv_id */
6501 PROP_cfg | PROP_ssa, /* properties_required */
6502 0, /* properties_provided */
6503 0, /* properties_destroyed */
6504 0, /* todo_flags_start */
6505 TODO_rebuild_alias | TODO_dump_func /* todo_flags_finish */
6510 /* Return true if we should execute IPA PTA. */
6516 /* Don't bother doing anything if the program has errors. */
6517 && !(errorcount || sorrycount));
6520 /* IPA PTA solutions for ESCAPED. */
6521 struct pt_solution ipa_escaped_pt
6522 = { true, false, false, false, false, false, false, NULL };
6524 /* Execute the driver for IPA PTA. */
6526 ipa_pta_execute (void)
6528 struct cgraph_node *node;
6529 struct varpool_node *var;
6534 init_alias_heapvars ();
6537 /* Build the constraints. */
6538 for (node = cgraph_nodes; node; node = node->next)
6540 /* Nodes without a body are not interesting. Especially do not
6541 visit clones at this point for now - we get duplicate decls
6542 there for inline clones at least. */
6543 if (!gimple_has_body_p (node->decl)
6547 create_function_info_for (node->decl,
6548 cgraph_node_name (node));
6551 /* Create constraints for global variables and their initializers. */
6552 for (var = varpool_nodes; var; var = var->next)
6553 get_vi_for_tree (var->decl);
6558 "Generating constraints for global initializers\n\n");
6559 dump_constraints (dump_file, 0);
6560 fprintf (dump_file, "\n");
6562 from = VEC_length (constraint_t, constraints);
6564 for (node = cgraph_nodes; node; node = node->next)
6566 struct function *func;
6570 /* Nodes without a body are not interesting. */
6571 if (!gimple_has_body_p (node->decl)
6577 "Generating constraints for %s\n",
6578 cgraph_node_name (node));
6580 func = DECL_STRUCT_FUNCTION (node->decl);
6581 old_func_decl = current_function_decl;
6583 current_function_decl = node->decl;
6585 /* For externally visible functions use local constraints for
6586 their arguments. For local functions we see all callers
6587 and thus do not need initial constraints for parameters. */
6588 if (node->local.externally_visible)
6589 intra_create_variable_infos ();
6591 /* Build constriants for the function body. */
6592 FOR_EACH_BB_FN (bb, func)
6594 gimple_stmt_iterator gsi;
6596 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
6599 gimple phi = gsi_stmt (gsi);
6601 if (is_gimple_reg (gimple_phi_result (phi)))
6602 find_func_aliases (phi);
6605 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6607 gimple stmt = gsi_stmt (gsi);
6609 find_func_aliases (stmt);
6610 find_func_clobbers (stmt);
6614 current_function_decl = old_func_decl;
6619 fprintf (dump_file, "\n");
6620 dump_constraints (dump_file, from);
6621 fprintf (dump_file, "\n");
6623 from = VEC_length (constraint_t, constraints);
6626 /* From the constraints compute the points-to sets. */
6627 solve_constraints ();
6629 /* Compute the global points-to sets for ESCAPED.
6630 ??? Note that the computed escape set is not correct
6631 for the whole unit as we fail to consider graph edges to
6632 externally visible functions. */
6633 find_what_var_points_to (get_varinfo (escaped_id), &ipa_escaped_pt);
6635 /* Make sure the ESCAPED solution (which is used as placeholder in
6636 other solutions) does not reference itself. This simplifies
6637 points-to solution queries. */
6638 ipa_escaped_pt.ipa_escaped = 0;
6640 /* Assign the points-to sets to the SSA names in the unit. */
6641 for (node = cgraph_nodes; node; node = node->next)
6644 struct function *fn;
6648 struct pt_solution uses, clobbers;
6649 struct cgraph_edge *e;
6651 /* Nodes without a body are not interesting. */
6652 if (!gimple_has_body_p (node->decl)
6656 fn = DECL_STRUCT_FUNCTION (node->decl);
6658 /* Compute the points-to sets for pointer SSA_NAMEs. */
6659 for (i = 0; VEC_iterate (tree, fn->gimple_df->ssa_names, i, ptr); ++i)
6662 && POINTER_TYPE_P (TREE_TYPE (ptr)))
6663 find_what_p_points_to (ptr);
6666 /* Compute the call-use and call-clobber sets for all direct calls. */
6667 fi = lookup_vi_for_tree (node->decl);
6668 gcc_assert (fi->is_fn_info);
6669 find_what_var_points_to (first_vi_for_offset (fi, fi_clobbers),
6671 find_what_var_points_to (first_vi_for_offset (fi, fi_uses), &uses);
6672 for (e = node->callers; e; e = e->next_caller)
6677 *gimple_call_clobber_set (e->call_stmt) = clobbers;
6678 *gimple_call_use_set (e->call_stmt) = uses;
6681 /* Compute the call-use and call-clobber sets for indirect calls
6682 and calls to external functions. */
6683 FOR_EACH_BB_FN (bb, fn)
6685 gimple_stmt_iterator gsi;
6687 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6689 gimple stmt = gsi_stmt (gsi);
6690 struct pt_solution *pt;
6694 if (!is_gimple_call (stmt))
6697 /* Handle direct calls to external functions. */
6698 decl = gimple_call_fndecl (stmt);
6700 && (!(fi = lookup_vi_for_tree (decl))
6701 || !fi->is_fn_info))
6703 pt = gimple_call_use_set (stmt);
6704 if (gimple_call_flags (stmt) & ECF_CONST)
6705 memset (pt, 0, sizeof (struct pt_solution));
6706 else if ((vi = lookup_call_use_vi (stmt)) != NULL)
6708 find_what_var_points_to (vi, pt);
6709 /* Escaped (and thus nonlocal) variables are always
6710 implicitly used by calls. */
6711 /* ??? ESCAPED can be empty even though NONLOCAL
6714 pt->ipa_escaped = 1;
6718 /* If there is nothing special about this call then
6719 we have made everything that is used also escape. */
6720 *pt = ipa_escaped_pt;
6724 pt = gimple_call_clobber_set (stmt);
6725 if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
6726 memset (pt, 0, sizeof (struct pt_solution));
6727 else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
6729 find_what_var_points_to (vi, pt);
6730 /* Escaped (and thus nonlocal) variables are always
6731 implicitly clobbered by calls. */
6732 /* ??? ESCAPED can be empty even though NONLOCAL
6735 pt->ipa_escaped = 1;
6739 /* If there is nothing special about this call then
6740 we have made everything that is used also escape. */
6741 *pt = ipa_escaped_pt;
6746 /* Handle indirect calls. */
6748 && (fi = get_fi_for_callee (stmt)))
6750 /* We need to accumulate all clobbers/uses of all possible
6752 fi = get_varinfo (find (fi->id));
6753 /* If we cannot constrain the set of functions we'll end up
6754 calling we end up using/clobbering everything. */
6755 if (bitmap_bit_p (fi->solution, anything_id)
6756 || bitmap_bit_p (fi->solution, nonlocal_id)
6757 || bitmap_bit_p (fi->solution, escaped_id))
6759 pt_solution_reset (gimple_call_clobber_set (stmt));
6760 pt_solution_reset (gimple_call_use_set (stmt));
6766 struct pt_solution *uses, *clobbers;
6768 uses = gimple_call_use_set (stmt);
6769 clobbers = gimple_call_clobber_set (stmt);
6770 memset (uses, 0, sizeof (struct pt_solution));
6771 memset (clobbers, 0, sizeof (struct pt_solution));
6772 EXECUTE_IF_SET_IN_BITMAP (fi->solution, 0, i, bi)
6774 struct pt_solution sol;
6776 vi = get_varinfo (i);
6777 if (!vi->is_fn_info)
6779 /* ??? We could be more precise here? */
6781 uses->ipa_escaped = 1;
6782 clobbers->nonlocal = 1;
6783 clobbers->ipa_escaped = 1;
6787 if (!uses->anything)
6789 find_what_var_points_to
6790 (first_vi_for_offset (vi, fi_uses), &sol);
6791 pt_solution_ior_into (uses, &sol);
6793 if (!clobbers->anything)
6795 find_what_var_points_to
6796 (first_vi_for_offset (vi, fi_clobbers), &sol);
6797 pt_solution_ior_into (clobbers, &sol);
6805 fn->gimple_df->ipa_pta = true;
6808 delete_points_to_sets ();
6815 struct simple_ipa_opt_pass pass_ipa_pta =
6820 gate_ipa_pta, /* gate */
6821 ipa_pta_execute, /* execute */
6824 0, /* static_pass_number */
6825 TV_IPA_PTA, /* tv_id */
6826 0, /* properties_required */
6827 0, /* properties_provided */
6828 0, /* properties_destroyed */
6829 0, /* todo_flags_start */
6830 TODO_update_ssa /* todo_flags_finish */
6835 #include "gt-tree-ssa-structalias.h"