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 VEC (ce_s, heap) *tmp = NULL;
3359 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), i, val)
3361 struct constraint_expr *rhsp;
3363 get_constraint_for_1 (val, &tmp, address_p);
3364 for (j = 0; VEC_iterate (ce_s, tmp, j, rhsp); ++j)
3365 VEC_safe_push (ce_s, heap, *results, rhsp);
3366 VEC_truncate (ce_s, tmp, 0);
3368 VEC_free (ce_s, heap, tmp);
3369 /* We do not know whether the constructor was complete,
3370 so technically we have to add &NOTHING or &ANYTHING
3371 like we do for an empty constructor as well. */
3378 case tcc_declaration:
3380 get_constraint_for_ssa_var (t, results, address_p);
3386 /* The default fallback is a constraint from anything. */
3387 temp.type = ADDRESSOF;
3388 temp.var = anything_id;
3390 VEC_safe_push (ce_s, heap, *results, &temp);
3393 /* Given a gimple tree T, return the constraint expression vector for it. */
3396 get_constraint_for (tree t, VEC (ce_s, heap) **results)
3398 gcc_assert (VEC_length (ce_s, *results) == 0);
3400 get_constraint_for_1 (t, results, false);
3404 /* Efficiently generates constraints from all entries in *RHSC to all
3405 entries in *LHSC. */
3408 process_all_all_constraints (VEC (ce_s, heap) *lhsc, VEC (ce_s, heap) *rhsc)
3410 struct constraint_expr *lhsp, *rhsp;
3413 if (VEC_length (ce_s, lhsc) <= 1
3414 || VEC_length (ce_s, rhsc) <= 1)
3416 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
3417 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); ++j)
3418 process_constraint (new_constraint (*lhsp, *rhsp));
3422 struct constraint_expr tmp;
3423 tmp = new_scalar_tmp_constraint_exp ("allalltmp");
3424 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
3425 process_constraint (new_constraint (tmp, *rhsp));
3426 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
3427 process_constraint (new_constraint (*lhsp, tmp));
3431 /* Handle aggregate copies by expanding into copies of the respective
3432 fields of the structures. */
3435 do_structure_copy (tree lhsop, tree rhsop)
3437 struct constraint_expr *lhsp, *rhsp;
3438 VEC (ce_s, heap) *lhsc = NULL, *rhsc = NULL;
3441 get_constraint_for (lhsop, &lhsc);
3442 get_constraint_for (rhsop, &rhsc);
3443 lhsp = VEC_index (ce_s, lhsc, 0);
3444 rhsp = VEC_index (ce_s, rhsc, 0);
3445 if (lhsp->type == DEREF
3446 || (lhsp->type == ADDRESSOF && lhsp->var == anything_id)
3447 || rhsp->type == DEREF)
3449 if (lhsp->type == DEREF)
3451 gcc_assert (VEC_length (ce_s, lhsc) == 1);
3452 lhsp->offset = UNKNOWN_OFFSET;
3454 if (rhsp->type == DEREF)
3456 gcc_assert (VEC_length (ce_s, rhsc) == 1);
3457 rhsp->offset = UNKNOWN_OFFSET;
3459 process_all_all_constraints (lhsc, rhsc);
3461 else if (lhsp->type == SCALAR
3462 && (rhsp->type == SCALAR
3463 || rhsp->type == ADDRESSOF))
3465 HOST_WIDE_INT lhssize, lhsmaxsize, lhsoffset;
3466 HOST_WIDE_INT rhssize, rhsmaxsize, rhsoffset;
3468 get_ref_base_and_extent (lhsop, &lhsoffset, &lhssize, &lhsmaxsize);
3469 get_ref_base_and_extent (rhsop, &rhsoffset, &rhssize, &rhsmaxsize);
3470 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp);)
3472 varinfo_t lhsv, rhsv;
3473 rhsp = VEC_index (ce_s, rhsc, k);
3474 lhsv = get_varinfo (lhsp->var);
3475 rhsv = get_varinfo (rhsp->var);
3476 if (lhsv->may_have_pointers
3477 && ranges_overlap_p (lhsv->offset + rhsoffset, lhsv->size,
3478 rhsv->offset + lhsoffset, rhsv->size))
3479 process_constraint (new_constraint (*lhsp, *rhsp));
3480 if (lhsv->offset + rhsoffset + lhsv->size
3481 > rhsv->offset + lhsoffset + rhsv->size)
3484 if (k >= VEC_length (ce_s, rhsc))
3494 VEC_free (ce_s, heap, lhsc);
3495 VEC_free (ce_s, heap, rhsc);
3498 /* Create a constraint ID = OP. */
3501 make_constraint_to (unsigned id, tree op)
3503 VEC(ce_s, heap) *rhsc = NULL;
3504 struct constraint_expr *c;
3505 struct constraint_expr includes;
3509 includes.offset = 0;
3510 includes.type = SCALAR;
3512 get_constraint_for (op, &rhsc);
3513 for (j = 0; VEC_iterate (ce_s, rhsc, j, c); j++)
3514 process_constraint (new_constraint (includes, *c));
3515 VEC_free (ce_s, heap, rhsc);
3518 /* Create a constraint ID = &FROM. */
3521 make_constraint_from (varinfo_t vi, int from)
3523 struct constraint_expr lhs, rhs;
3531 rhs.type = ADDRESSOF;
3532 process_constraint (new_constraint (lhs, rhs));
3535 /* Create a constraint ID = FROM. */
3538 make_copy_constraint (varinfo_t vi, int from)
3540 struct constraint_expr lhs, rhs;
3549 process_constraint (new_constraint (lhs, rhs));
3552 /* Make constraints necessary to make OP escape. */
3555 make_escape_constraint (tree op)
3557 make_constraint_to (escaped_id, op);
3560 /* Add constraints to that the solution of VI is transitively closed. */
3563 make_transitive_closure_constraints (varinfo_t vi)
3565 struct constraint_expr lhs, rhs;
3574 process_constraint (new_constraint (lhs, rhs));
3576 /* VAR = VAR + UNKNOWN; */
3582 rhs.offset = UNKNOWN_OFFSET;
3583 process_constraint (new_constraint (lhs, rhs));
3586 /* Create a new artificial heap variable with NAME and make a
3587 constraint from it to LHS. Return the created variable. */
3590 make_constraint_from_heapvar (varinfo_t lhs, const char *name)
3593 tree heapvar = heapvar_lookup (lhs->decl, lhs->offset);
3595 if (heapvar == NULL_TREE)
3598 heapvar = create_tmp_var_raw (ptr_type_node, name);
3599 DECL_EXTERNAL (heapvar) = 1;
3601 heapvar_insert (lhs->decl, lhs->offset, heapvar);
3603 ann = get_var_ann (heapvar);
3604 ann->is_heapvar = 1;
3607 /* For global vars we need to add a heapvar to the list of referenced
3608 vars of a different function than it was created for originally. */
3609 if (cfun && gimple_referenced_vars (cfun))
3610 add_referenced_var (heapvar);
3612 vi = new_var_info (heapvar, name);
3613 vi->is_artificial_var = true;
3614 vi->is_heap_var = true;
3615 vi->is_unknown_size_var = true;
3619 vi->is_full_var = true;
3620 insert_vi_for_tree (heapvar, vi);
3622 make_constraint_from (lhs, vi->id);
3627 /* Create a new artificial heap variable with NAME and make a
3628 constraint from it to LHS. Set flags according to a tag used
3629 for tracking restrict pointers. */
3632 make_constraint_from_restrict (varinfo_t lhs, const char *name)
3635 vi = make_constraint_from_heapvar (lhs, name);
3636 vi->is_restrict_var = 1;
3637 vi->is_global_var = 0;
3638 vi->is_special_var = 1;
3639 vi->may_have_pointers = 0;
3642 /* In IPA mode there are varinfos for different aspects of reach
3643 function designator. One for the points-to set of the return
3644 value, one for the variables that are clobbered by the function,
3645 one for its uses and one for each parameter (including a single
3646 glob for remaining variadic arguments). */
3648 enum { fi_clobbers = 1, fi_uses = 2,
3649 fi_static_chain = 3, fi_result = 4, fi_parm_base = 5 };
3651 /* Get a constraint for the requested part of a function designator FI
3652 when operating in IPA mode. */
3654 static struct constraint_expr
3655 get_function_part_constraint (varinfo_t fi, unsigned part)
3657 struct constraint_expr c;
3659 gcc_assert (in_ipa_mode);
3661 if (fi->id == anything_id)
3663 /* ??? We probably should have a ANYFN special variable. */
3664 c.var = anything_id;
3668 else if (TREE_CODE (fi->decl) == FUNCTION_DECL)
3670 varinfo_t ai = first_vi_for_offset (fi, part);
3674 c.var = anything_id;
3688 /* For non-IPA mode, generate constraints necessary for a call on the
3692 handle_rhs_call (gimple stmt, VEC(ce_s, heap) **results)
3694 struct constraint_expr rhsc;
3697 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3699 tree arg = gimple_call_arg (stmt, i);
3701 /* Find those pointers being passed, and make sure they end up
3702 pointing to anything. */
3703 if (could_have_pointers (arg))
3704 make_escape_constraint (arg);
3707 /* The static chain escapes as well. */
3708 if (gimple_call_chain (stmt))
3709 make_escape_constraint (gimple_call_chain (stmt));
3711 /* And if we applied NRV the address of the return slot escapes as well. */
3712 if (gimple_call_return_slot_opt_p (stmt)
3713 && gimple_call_lhs (stmt) != NULL_TREE
3714 && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt))))
3716 VEC(ce_s, heap) *tmpc = NULL;
3717 struct constraint_expr lhsc, *c;
3718 get_constraint_for_address_of (gimple_call_lhs (stmt), &tmpc);
3719 lhsc.var = escaped_id;
3722 for (i = 0; VEC_iterate (ce_s, tmpc, i, c); ++i)
3723 process_constraint (new_constraint (lhsc, *c));
3724 VEC_free(ce_s, heap, tmpc);
3727 /* Regular functions return nonlocal memory. */
3728 rhsc.var = nonlocal_id;
3731 VEC_safe_push (ce_s, heap, *results, &rhsc);
3734 /* For non-IPA mode, generate constraints necessary for a call
3735 that returns a pointer and assigns it to LHS. This simply makes
3736 the LHS point to global and escaped variables. */
3739 handle_lhs_call (tree lhs, int flags, VEC(ce_s, heap) *rhsc, tree fndecl)
3741 VEC(ce_s, heap) *lhsc = NULL;
3743 get_constraint_for (lhs, &lhsc);
3745 if (flags & ECF_MALLOC)
3748 vi = make_constraint_from_heapvar (get_vi_for_tree (lhs), "HEAP");
3749 /* We delay marking allocated storage global until we know if
3751 DECL_EXTERNAL (vi->decl) = 0;
3752 vi->is_global_var = 0;
3753 /* If this is not a real malloc call assume the memory was
3754 initialized and thus may point to global memory. All
3755 builtin functions with the malloc attribute behave in a sane way. */
3757 || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
3758 make_constraint_from (vi, nonlocal_id);
3760 else if (VEC_length (ce_s, rhsc) > 0)
3762 /* If the store is to a global decl make sure to
3763 add proper escape constraints. */
3764 lhs = get_base_address (lhs);
3767 && is_global_var (lhs))
3769 struct constraint_expr tmpc;
3770 tmpc.var = escaped_id;
3773 VEC_safe_push (ce_s, heap, lhsc, &tmpc);
3775 process_all_all_constraints (lhsc, rhsc);
3777 VEC_free (ce_s, heap, lhsc);
3780 /* For non-IPA mode, generate constraints necessary for a call of a
3781 const function that returns a pointer in the statement STMT. */
3784 handle_const_call (gimple stmt, VEC(ce_s, heap) **results)
3786 struct constraint_expr rhsc;
3789 /* Treat nested const functions the same as pure functions as far
3790 as the static chain is concerned. */
3791 if (gimple_call_chain (stmt))
3793 varinfo_t uses = get_call_use_vi (stmt);
3794 make_transitive_closure_constraints (uses);
3795 make_constraint_to (uses->id, gimple_call_chain (stmt));
3796 rhsc.var = uses->id;
3799 VEC_safe_push (ce_s, heap, *results, &rhsc);
3802 /* May return arguments. */
3803 for (k = 0; k < gimple_call_num_args (stmt); ++k)
3805 tree arg = gimple_call_arg (stmt, k);
3807 if (could_have_pointers (arg))
3809 VEC(ce_s, heap) *argc = NULL;
3811 struct constraint_expr *argp;
3812 get_constraint_for (arg, &argc);
3813 for (i = 0; VEC_iterate (ce_s, argc, i, argp); ++i)
3814 VEC_safe_push (ce_s, heap, *results, argp);
3815 VEC_free(ce_s, heap, argc);
3819 /* May return addresses of globals. */
3820 rhsc.var = nonlocal_id;
3822 rhsc.type = ADDRESSOF;
3823 VEC_safe_push (ce_s, heap, *results, &rhsc);
3826 /* For non-IPA mode, generate constraints necessary for a call to a
3827 pure function in statement STMT. */
3830 handle_pure_call (gimple stmt, VEC(ce_s, heap) **results)
3832 struct constraint_expr rhsc;
3834 varinfo_t uses = NULL;
3836 /* Memory reached from pointer arguments is call-used. */
3837 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3839 tree arg = gimple_call_arg (stmt, i);
3841 if (could_have_pointers (arg))
3845 uses = get_call_use_vi (stmt);
3846 make_transitive_closure_constraints (uses);
3848 make_constraint_to (uses->id, arg);
3852 /* The static chain is used as well. */
3853 if (gimple_call_chain (stmt))
3857 uses = get_call_use_vi (stmt);
3858 make_transitive_closure_constraints (uses);
3860 make_constraint_to (uses->id, gimple_call_chain (stmt));
3863 /* Pure functions may return call-used and nonlocal memory. */
3866 rhsc.var = uses->id;
3869 VEC_safe_push (ce_s, heap, *results, &rhsc);
3871 rhsc.var = nonlocal_id;
3874 VEC_safe_push (ce_s, heap, *results, &rhsc);
3878 /* Return the varinfo for the callee of CALL. */
3881 get_fi_for_callee (gimple call)
3885 /* If we can directly resolve the function being called, do so.
3886 Otherwise, it must be some sort of indirect expression that
3887 we should still be able to handle. */
3888 decl = gimple_call_fndecl (call);
3890 return get_vi_for_tree (decl);
3892 decl = gimple_call_fn (call);
3893 /* The function can be either an SSA name pointer or,
3894 worse, an OBJ_TYPE_REF. In this case we have no
3895 clue and should be getting ANYFN (well, ANYTHING for now). */
3896 if (TREE_CODE (decl) == SSA_NAME)
3898 if (TREE_CODE (decl) == SSA_NAME
3899 && TREE_CODE (SSA_NAME_VAR (decl)) == PARM_DECL
3900 && SSA_NAME_IS_DEFAULT_DEF (decl))
3901 decl = SSA_NAME_VAR (decl);
3902 return get_vi_for_tree (decl);
3904 else if (TREE_CODE (decl) == INTEGER_CST
3905 || TREE_CODE (decl) == OBJ_TYPE_REF)
3906 return get_varinfo (anything_id);
3911 /* Walk statement T setting up aliasing constraints according to the
3912 references found in T. This function is the main part of the
3913 constraint builder. AI points to auxiliary alias information used
3914 when building alias sets and computing alias grouping heuristics. */
3917 find_func_aliases (gimple origt)
3920 VEC(ce_s, heap) *lhsc = NULL;
3921 VEC(ce_s, heap) *rhsc = NULL;
3922 struct constraint_expr *c;
3925 /* Now build constraints expressions. */
3926 if (gimple_code (t) == GIMPLE_PHI)
3928 gcc_assert (!AGGREGATE_TYPE_P (TREE_TYPE (gimple_phi_result (t))));
3930 /* Only care about pointers and structures containing
3932 if (could_have_pointers (gimple_phi_result (t)))
3937 /* For a phi node, assign all the arguments to
3939 get_constraint_for (gimple_phi_result (t), &lhsc);
3940 for (i = 0; i < gimple_phi_num_args (t); i++)
3942 tree strippedrhs = PHI_ARG_DEF (t, i);
3944 STRIP_NOPS (strippedrhs);
3945 get_constraint_for (gimple_phi_arg_def (t, i), &rhsc);
3947 for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
3949 struct constraint_expr *c2;
3950 while (VEC_length (ce_s, rhsc) > 0)
3952 c2 = VEC_last (ce_s, rhsc);
3953 process_constraint (new_constraint (*c, *c2));
3954 VEC_pop (ce_s, rhsc);
3960 /* In IPA mode, we need to generate constraints to pass call
3961 arguments through their calls. There are two cases,
3962 either a GIMPLE_CALL returning a value, or just a plain
3963 GIMPLE_CALL when we are not.
3965 In non-ipa mode, we need to generate constraints for each
3966 pointer passed by address. */
3967 else if (is_gimple_call (t))
3969 tree fndecl = gimple_call_fndecl (t);
3970 if (fndecl != NULL_TREE
3971 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
3972 /* ??? All builtins that are handled here need to be handled
3973 in the alias-oracle query functions explicitly! */
3974 switch (DECL_FUNCTION_CODE (fndecl))
3976 /* All the following functions return a pointer to the same object
3977 as their first argument points to. The functions do not add
3978 to the ESCAPED solution. The functions make the first argument
3979 pointed to memory point to what the second argument pointed to
3980 memory points to. */
3981 case BUILT_IN_STRCPY:
3982 case BUILT_IN_STRNCPY:
3983 case BUILT_IN_BCOPY:
3984 case BUILT_IN_MEMCPY:
3985 case BUILT_IN_MEMMOVE:
3986 case BUILT_IN_MEMPCPY:
3987 case BUILT_IN_STPCPY:
3988 case BUILT_IN_STPNCPY:
3989 case BUILT_IN_STRCAT:
3990 case BUILT_IN_STRNCAT:
3992 tree res = gimple_call_lhs (t);
3993 tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
3994 == BUILT_IN_BCOPY ? 1 : 0));
3995 tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
3996 == BUILT_IN_BCOPY ? 0 : 1));
3997 if (res != NULL_TREE)
3999 get_constraint_for (res, &lhsc);
4000 if (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMPCPY
4001 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPCPY
4002 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPNCPY)
4003 get_constraint_for_ptr_offset (dest, NULL_TREE, &rhsc);
4005 get_constraint_for (dest, &rhsc);
4006 process_all_all_constraints (lhsc, rhsc);
4007 VEC_free (ce_s, heap, lhsc);
4008 VEC_free (ce_s, heap, rhsc);
4010 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4011 get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
4014 process_all_all_constraints (lhsc, rhsc);
4015 VEC_free (ce_s, heap, lhsc);
4016 VEC_free (ce_s, heap, rhsc);
4019 case BUILT_IN_MEMSET:
4021 tree res = gimple_call_lhs (t);
4022 tree dest = gimple_call_arg (t, 0);
4025 struct constraint_expr ac;
4026 if (res != NULL_TREE)
4028 get_constraint_for (res, &lhsc);
4029 get_constraint_for (dest, &rhsc);
4030 process_all_all_constraints (lhsc, rhsc);
4031 VEC_free (ce_s, heap, lhsc);
4032 VEC_free (ce_s, heap, rhsc);
4034 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4036 if (flag_delete_null_pointer_checks
4037 && integer_zerop (gimple_call_arg (t, 1)))
4039 ac.type = ADDRESSOF;
4040 ac.var = nothing_id;
4045 ac.var = integer_id;
4048 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
4049 process_constraint (new_constraint (*lhsp, ac));
4050 VEC_free (ce_s, heap, lhsc);
4053 /* All the following functions do not return pointers, do not
4054 modify the points-to sets of memory reachable from their
4055 arguments and do not add to the ESCAPED solution. */
4056 case BUILT_IN_SINCOS:
4057 case BUILT_IN_SINCOSF:
4058 case BUILT_IN_SINCOSL:
4059 case BUILT_IN_FREXP:
4060 case BUILT_IN_FREXPF:
4061 case BUILT_IN_FREXPL:
4062 case BUILT_IN_GAMMA_R:
4063 case BUILT_IN_GAMMAF_R:
4064 case BUILT_IN_GAMMAL_R:
4065 case BUILT_IN_LGAMMA_R:
4066 case BUILT_IN_LGAMMAF_R:
4067 case BUILT_IN_LGAMMAL_R:
4069 case BUILT_IN_MODFF:
4070 case BUILT_IN_MODFL:
4071 case BUILT_IN_REMQUO:
4072 case BUILT_IN_REMQUOF:
4073 case BUILT_IN_REMQUOL:
4076 /* Trampolines are special - they set up passing the static
4078 case BUILT_IN_INIT_TRAMPOLINE:
4080 tree tramp = gimple_call_arg (t, 0);
4081 tree nfunc = gimple_call_arg (t, 1);
4082 tree frame = gimple_call_arg (t, 2);
4084 struct constraint_expr lhs, *rhsp;
4087 varinfo_t nfi = NULL;
4088 gcc_assert (TREE_CODE (nfunc) == ADDR_EXPR);
4089 nfi = lookup_vi_for_tree (TREE_OPERAND (nfunc, 0));
4092 lhs = get_function_part_constraint (nfi, fi_static_chain);
4093 get_constraint_for (frame, &rhsc);
4094 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
4095 process_constraint (new_constraint (lhs, *rhsp));
4096 VEC_free (ce_s, heap, rhsc);
4098 /* Make the frame point to the function for
4099 the trampoline adjustment call. */
4100 get_constraint_for (tramp, &lhsc);
4102 get_constraint_for (nfunc, &rhsc);
4103 process_all_all_constraints (lhsc, rhsc);
4104 VEC_free (ce_s, heap, rhsc);
4105 VEC_free (ce_s, heap, lhsc);
4110 /* Else fallthru to generic handling which will let
4111 the frame escape. */
4114 case BUILT_IN_ADJUST_TRAMPOLINE:
4116 tree tramp = gimple_call_arg (t, 0);
4117 tree res = gimple_call_lhs (t);
4118 if (in_ipa_mode && res)
4120 get_constraint_for (res, &lhsc);
4121 get_constraint_for (tramp, &rhsc);
4123 process_all_all_constraints (lhsc, rhsc);
4124 VEC_free (ce_s, heap, rhsc);
4125 VEC_free (ce_s, heap, lhsc);
4129 /* Variadic argument handling needs to be handled in IPA
4131 case BUILT_IN_VA_START:
4135 tree valist = gimple_call_arg (t, 0);
4136 struct constraint_expr rhs, *lhsp;
4138 /* The va_list gets access to pointers in variadic
4140 fi = lookup_vi_for_tree (cfun->decl);
4141 gcc_assert (fi != NULL);
4142 get_constraint_for (valist, &lhsc);
4144 rhs = get_function_part_constraint (fi, ~0);
4145 rhs.type = ADDRESSOF;
4146 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
4147 process_constraint (new_constraint (*lhsp, rhs));
4148 VEC_free (ce_s, heap, lhsc);
4149 /* va_list is clobbered. */
4150 make_constraint_to (get_call_clobber_vi (t)->id, valist);
4155 /* va_end doesn't have any effect that matters. */
4156 case BUILT_IN_VA_END:
4158 /* printf-style functions may have hooks to set pointers to
4159 point to somewhere into the generated string. Leave them
4160 for a later excercise... */
4162 /* Fallthru to general call handling. */;
4166 && (!(fi = lookup_vi_for_tree (fndecl))
4167 || !fi->is_fn_info)))
4169 VEC(ce_s, heap) *rhsc = NULL;
4170 int flags = gimple_call_flags (t);
4172 /* Const functions can return their arguments and addresses
4173 of global memory but not of escaped memory. */
4174 if (flags & (ECF_CONST|ECF_NOVOPS))
4176 if (gimple_call_lhs (t)
4177 && could_have_pointers (gimple_call_lhs (t)))
4178 handle_const_call (t, &rhsc);
4180 /* Pure functions can return addresses in and of memory
4181 reachable from their arguments, but they are not an escape
4182 point for reachable memory of their arguments. */
4183 else if (flags & (ECF_PURE|ECF_LOOPING_CONST_OR_PURE))
4184 handle_pure_call (t, &rhsc);
4186 handle_rhs_call (t, &rhsc);
4187 if (gimple_call_lhs (t)
4188 && could_have_pointers (gimple_call_lhs (t)))
4189 handle_lhs_call (gimple_call_lhs (t), flags, rhsc, fndecl);
4190 VEC_free (ce_s, heap, rhsc);
4197 fi = get_fi_for_callee (t);
4199 /* Assign all the passed arguments to the appropriate incoming
4200 parameters of the function. */
4201 for (j = 0; j < gimple_call_num_args (t); j++)
4203 struct constraint_expr lhs ;
4204 struct constraint_expr *rhsp;
4205 tree arg = gimple_call_arg (t, j);
4207 if (!could_have_pointers (arg))
4210 get_constraint_for (arg, &rhsc);
4211 lhs = get_function_part_constraint (fi, fi_parm_base + j);
4212 while (VEC_length (ce_s, rhsc) != 0)
4214 rhsp = VEC_last (ce_s, rhsc);
4215 process_constraint (new_constraint (lhs, *rhsp));
4216 VEC_pop (ce_s, rhsc);
4220 /* If we are returning a value, assign it to the result. */
4221 lhsop = gimple_call_lhs (t);
4223 && could_have_pointers (lhsop))
4225 struct constraint_expr rhs;
4226 struct constraint_expr *lhsp;
4228 get_constraint_for (lhsop, &lhsc);
4229 rhs = get_function_part_constraint (fi, fi_result);
4231 && DECL_RESULT (fndecl)
4232 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
4234 VEC(ce_s, heap) *tem = NULL;
4235 VEC_safe_push (ce_s, heap, tem, &rhs);
4237 rhs = *VEC_index (ce_s, tem, 0);
4238 VEC_free(ce_s, heap, tem);
4240 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
4241 process_constraint (new_constraint (*lhsp, rhs));
4244 /* If we pass the result decl by reference, honor that. */
4247 && DECL_RESULT (fndecl)
4248 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
4250 struct constraint_expr lhs;
4251 struct constraint_expr *rhsp;
4253 get_constraint_for_address_of (lhsop, &rhsc);
4254 lhs = get_function_part_constraint (fi, fi_result);
4255 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4256 process_constraint (new_constraint (lhs, *rhsp));
4257 VEC_free (ce_s, heap, rhsc);
4260 /* If we use a static chain, pass it along. */
4261 if (gimple_call_chain (t))
4263 struct constraint_expr lhs;
4264 struct constraint_expr *rhsp;
4266 get_constraint_for (gimple_call_chain (t), &rhsc);
4267 lhs = get_function_part_constraint (fi, fi_static_chain);
4268 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4269 process_constraint (new_constraint (lhs, *rhsp));
4273 /* Otherwise, just a regular assignment statement. Only care about
4274 operations with pointer result, others are dealt with as escape
4275 points if they have pointer operands. */
4276 else if (is_gimple_assign (t)
4277 && could_have_pointers (gimple_assign_lhs (t)))
4279 /* Otherwise, just a regular assignment statement. */
4280 tree lhsop = gimple_assign_lhs (t);
4281 tree rhsop = (gimple_num_ops (t) == 2) ? gimple_assign_rhs1 (t) : NULL;
4283 if (rhsop && AGGREGATE_TYPE_P (TREE_TYPE (lhsop)))
4284 do_structure_copy (lhsop, rhsop);
4287 struct constraint_expr temp;
4288 get_constraint_for (lhsop, &lhsc);
4290 if (gimple_assign_rhs_code (t) == POINTER_PLUS_EXPR)
4291 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
4292 gimple_assign_rhs2 (t), &rhsc);
4293 else if ((CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (t))
4294 && !(POINTER_TYPE_P (gimple_expr_type (t))
4295 && !POINTER_TYPE_P (TREE_TYPE (rhsop))))
4296 || gimple_assign_single_p (t))
4297 get_constraint_for (rhsop, &rhsc);
4300 temp.type = ADDRESSOF;
4301 temp.var = anything_id;
4303 VEC_safe_push (ce_s, heap, rhsc, &temp);
4305 process_all_all_constraints (lhsc, rhsc);
4307 /* If there is a store to a global variable the rhs escapes. */
4308 if ((lhsop = get_base_address (lhsop)) != NULL_TREE
4310 && is_global_var (lhsop)
4312 || DECL_EXTERNAL (lhsop) || TREE_PUBLIC (lhsop)))
4313 make_escape_constraint (rhsop);
4314 /* If this is a conversion of a non-restrict pointer to a
4315 restrict pointer track it with a new heapvar. */
4316 else if (gimple_assign_cast_p (t)
4317 && POINTER_TYPE_P (TREE_TYPE (rhsop))
4318 && POINTER_TYPE_P (TREE_TYPE (lhsop))
4319 && !TYPE_RESTRICT (TREE_TYPE (rhsop))
4320 && TYPE_RESTRICT (TREE_TYPE (lhsop)))
4321 make_constraint_from_restrict (get_vi_for_tree (lhsop),
4324 /* For conversions of pointers to non-pointers the pointer escapes. */
4325 else if (gimple_assign_cast_p (t)
4326 && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (t)))
4327 && !POINTER_TYPE_P (TREE_TYPE (gimple_assign_lhs (t))))
4329 make_escape_constraint (gimple_assign_rhs1 (t));
4331 /* Handle escapes through return. */
4332 else if (gimple_code (t) == GIMPLE_RETURN
4333 && gimple_return_retval (t) != NULL_TREE
4334 && could_have_pointers (gimple_return_retval (t)))
4338 || !(fi = get_vi_for_tree (cfun->decl)))
4339 make_escape_constraint (gimple_return_retval (t));
4340 else if (in_ipa_mode
4343 struct constraint_expr lhs ;
4344 struct constraint_expr *rhsp;
4347 lhs = get_function_part_constraint (fi, fi_result);
4348 get_constraint_for (gimple_return_retval (t), &rhsc);
4349 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4350 process_constraint (new_constraint (lhs, *rhsp));
4353 /* Handle asms conservatively by adding escape constraints to everything. */
4354 else if (gimple_code (t) == GIMPLE_ASM)
4356 unsigned i, noutputs;
4357 const char **oconstraints;
4358 const char *constraint;
4359 bool allows_mem, allows_reg, is_inout;
4361 noutputs = gimple_asm_noutputs (t);
4362 oconstraints = XALLOCAVEC (const char *, noutputs);
4364 for (i = 0; i < noutputs; ++i)
4366 tree link = gimple_asm_output_op (t, i);
4367 tree op = TREE_VALUE (link);
4369 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
4370 oconstraints[i] = constraint;
4371 parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
4372 &allows_reg, &is_inout);
4374 /* A memory constraint makes the address of the operand escape. */
4375 if (!allows_reg && allows_mem)
4376 make_escape_constraint (build_fold_addr_expr (op));
4378 /* The asm may read global memory, so outputs may point to
4379 any global memory. */
4380 if (op && could_have_pointers (op))
4382 VEC(ce_s, heap) *lhsc = NULL;
4383 struct constraint_expr rhsc, *lhsp;
4385 get_constraint_for (op, &lhsc);
4386 rhsc.var = nonlocal_id;
4389 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
4390 process_constraint (new_constraint (*lhsp, rhsc));
4391 VEC_free (ce_s, heap, lhsc);
4394 for (i = 0; i < gimple_asm_ninputs (t); ++i)
4396 tree link = gimple_asm_input_op (t, i);
4397 tree op = TREE_VALUE (link);
4399 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
4401 parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints,
4402 &allows_mem, &allows_reg);
4404 /* A memory constraint makes the address of the operand escape. */
4405 if (!allows_reg && allows_mem)
4406 make_escape_constraint (build_fold_addr_expr (op));
4407 /* Strictly we'd only need the constraint to ESCAPED if
4408 the asm clobbers memory, otherwise using something
4409 along the lines of per-call clobbers/uses would be enough. */
4410 else if (op && could_have_pointers (op))
4411 make_escape_constraint (op);
4415 VEC_free (ce_s, heap, rhsc);
4416 VEC_free (ce_s, heap, lhsc);
4420 /* Create a constraint adding to the clobber set of FI the memory
4421 pointed to by PTR. */
4424 process_ipa_clobber (varinfo_t fi, tree ptr)
4426 VEC(ce_s, heap) *ptrc = NULL;
4427 struct constraint_expr *c, lhs;
4429 get_constraint_for (ptr, &ptrc);
4430 lhs = get_function_part_constraint (fi, fi_clobbers);
4431 for (i = 0; VEC_iterate (ce_s, ptrc, i, c); i++)
4432 process_constraint (new_constraint (lhs, *c));
4433 VEC_free (ce_s, heap, ptrc);
4436 /* Walk statement T setting up clobber and use constraints according to the
4437 references found in T. This function is a main part of the
4438 IPA constraint builder. */
4441 find_func_clobbers (gimple origt)
4444 VEC(ce_s, heap) *lhsc = NULL;
4445 VEC(ce_s, heap) *rhsc = NULL;
4448 /* Add constraints for clobbered/used in IPA mode.
4449 We are not interested in what automatic variables are clobbered
4450 or used as we only use the information in the caller to which
4451 they do not escape. */
4452 gcc_assert (in_ipa_mode);
4454 /* If the stmt refers to memory in any way it better had a VUSE. */
4455 if (gimple_vuse (t) == NULL_TREE)
4458 /* We'd better have function information for the current function. */
4459 fi = lookup_vi_for_tree (cfun->decl);
4460 gcc_assert (fi != NULL);
4462 /* Account for stores in assignments and calls. */
4463 if (gimple_vdef (t) != NULL_TREE
4464 && gimple_has_lhs (t))
4466 tree lhs = gimple_get_lhs (t);
4468 while (handled_component_p (tem))
4469 tem = TREE_OPERAND (tem, 0);
4471 && !auto_var_in_fn_p (tem, cfun->decl))
4472 || INDIRECT_REF_P (tem))
4474 struct constraint_expr lhsc, *rhsp;
4476 lhsc = get_function_part_constraint (fi, fi_clobbers);
4477 get_constraint_for_address_of (lhs, &rhsc);
4478 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4479 process_constraint (new_constraint (lhsc, *rhsp));
4480 VEC_free (ce_s, heap, rhsc);
4484 /* Account for uses in assigments and returns. */
4485 if (gimple_assign_single_p (t)
4486 || (gimple_code (t) == GIMPLE_RETURN
4487 && gimple_return_retval (t) != NULL_TREE))
4489 tree rhs = (gimple_assign_single_p (t)
4490 ? gimple_assign_rhs1 (t) : gimple_return_retval (t));
4492 while (handled_component_p (tem))
4493 tem = TREE_OPERAND (tem, 0);
4495 && !auto_var_in_fn_p (tem, cfun->decl))
4496 || INDIRECT_REF_P (tem))
4498 struct constraint_expr lhs, *rhsp;
4500 lhs = get_function_part_constraint (fi, fi_uses);
4501 get_constraint_for_address_of (rhs, &rhsc);
4502 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4503 process_constraint (new_constraint (lhs, *rhsp));
4504 VEC_free (ce_s, heap, rhsc);
4508 if (is_gimple_call (t))
4510 varinfo_t cfi = NULL;
4511 tree decl = gimple_call_fndecl (t);
4512 struct constraint_expr lhs, rhs;
4515 /* For builtins we do not have separate function info. For those
4516 we do not generate escapes for we have to generate clobbers/uses. */
4518 && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
4519 switch (DECL_FUNCTION_CODE (decl))
4521 /* The following functions use and clobber memory pointed to
4522 by their arguments. */
4523 case BUILT_IN_STRCPY:
4524 case BUILT_IN_STRNCPY:
4525 case BUILT_IN_BCOPY:
4526 case BUILT_IN_MEMCPY:
4527 case BUILT_IN_MEMMOVE:
4528 case BUILT_IN_MEMPCPY:
4529 case BUILT_IN_STPCPY:
4530 case BUILT_IN_STPNCPY:
4531 case BUILT_IN_STRCAT:
4532 case BUILT_IN_STRNCAT:
4534 tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
4535 == BUILT_IN_BCOPY ? 1 : 0));
4536 tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
4537 == BUILT_IN_BCOPY ? 0 : 1));
4539 struct constraint_expr *rhsp, *lhsp;
4540 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4541 lhs = get_function_part_constraint (fi, fi_clobbers);
4542 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); i++)
4543 process_constraint (new_constraint (lhs, *lhsp));
4544 VEC_free (ce_s, heap, lhsc);
4545 get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
4546 lhs = get_function_part_constraint (fi, fi_uses);
4547 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4548 process_constraint (new_constraint (lhs, *rhsp));
4549 VEC_free (ce_s, heap, rhsc);
4552 /* The following function clobbers memory pointed to by
4554 case BUILT_IN_MEMSET:
4556 tree dest = gimple_call_arg (t, 0);
4559 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4560 lhs = get_function_part_constraint (fi, fi_clobbers);
4561 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); i++)
4562 process_constraint (new_constraint (lhs, *lhsp));
4563 VEC_free (ce_s, heap, lhsc);
4566 /* The following functions clobber their second and third
4568 case BUILT_IN_SINCOS:
4569 case BUILT_IN_SINCOSF:
4570 case BUILT_IN_SINCOSL:
4572 process_ipa_clobber (fi, gimple_call_arg (t, 1));
4573 process_ipa_clobber (fi, gimple_call_arg (t, 2));
4576 /* The following functions clobber their second argument. */
4577 case BUILT_IN_FREXP:
4578 case BUILT_IN_FREXPF:
4579 case BUILT_IN_FREXPL:
4580 case BUILT_IN_LGAMMA_R:
4581 case BUILT_IN_LGAMMAF_R:
4582 case BUILT_IN_LGAMMAL_R:
4583 case BUILT_IN_GAMMA_R:
4584 case BUILT_IN_GAMMAF_R:
4585 case BUILT_IN_GAMMAL_R:
4587 case BUILT_IN_MODFF:
4588 case BUILT_IN_MODFL:
4590 process_ipa_clobber (fi, gimple_call_arg (t, 1));
4593 /* The following functions clobber their third argument. */
4594 case BUILT_IN_REMQUO:
4595 case BUILT_IN_REMQUOF:
4596 case BUILT_IN_REMQUOL:
4598 process_ipa_clobber (fi, gimple_call_arg (t, 2));
4601 /* The following functions neither read nor clobber memory. */
4604 /* Trampolines are of no interest to us. */
4605 case BUILT_IN_INIT_TRAMPOLINE:
4606 case BUILT_IN_ADJUST_TRAMPOLINE:
4608 case BUILT_IN_VA_START:
4609 case BUILT_IN_VA_END:
4611 /* printf-style functions may have hooks to set pointers to
4612 point to somewhere into the generated string. Leave them
4613 for a later excercise... */
4615 /* Fallthru to general call handling. */;
4618 /* Parameters passed by value are used. */
4619 lhs = get_function_part_constraint (fi, fi_uses);
4620 for (i = 0; i < gimple_call_num_args (t); i++)
4622 struct constraint_expr *rhsp;
4623 tree arg = gimple_call_arg (t, i);
4625 if (TREE_CODE (arg) == SSA_NAME
4626 || is_gimple_min_invariant (arg))
4629 get_constraint_for_address_of (arg, &rhsc);
4630 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4631 process_constraint (new_constraint (lhs, *rhsp));
4632 VEC_free (ce_s, heap, rhsc);
4635 /* Build constraints for propagating clobbers/uses along the
4637 cfi = get_fi_for_callee (t);
4638 if (cfi->id == anything_id)
4640 if (gimple_vdef (t))
4641 make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
4643 make_constraint_from (first_vi_for_offset (fi, fi_uses),
4648 /* For callees without function info (that's external functions),
4649 ESCAPED is clobbered and used. */
4650 if (gimple_call_fndecl (t)
4651 && !cfi->is_fn_info)
4655 if (gimple_vdef (t))
4656 make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
4658 make_copy_constraint (first_vi_for_offset (fi, fi_uses), escaped_id);
4660 /* Also honor the call statement use/clobber info. */
4661 if ((vi = lookup_call_clobber_vi (t)) != NULL)
4662 make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
4664 if ((vi = lookup_call_use_vi (t)) != NULL)
4665 make_copy_constraint (first_vi_for_offset (fi, fi_uses),
4670 /* Otherwise the caller clobbers and uses what the callee does.
4671 ??? This should use a new complex constraint that filters
4672 local variables of the callee. */
4673 if (gimple_vdef (t))
4675 lhs = get_function_part_constraint (fi, fi_clobbers);
4676 rhs = get_function_part_constraint (cfi, fi_clobbers);
4677 process_constraint (new_constraint (lhs, rhs));
4679 lhs = get_function_part_constraint (fi, fi_uses);
4680 rhs = get_function_part_constraint (cfi, fi_uses);
4681 process_constraint (new_constraint (lhs, rhs));
4683 else if (gimple_code (t) == GIMPLE_ASM)
4685 /* ??? Ick. We can do better. */
4686 if (gimple_vdef (t))
4687 make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
4689 make_constraint_from (first_vi_for_offset (fi, fi_uses),
4693 VEC_free (ce_s, heap, rhsc);
4697 /* Find the first varinfo in the same variable as START that overlaps with
4698 OFFSET. Return NULL if we can't find one. */
4701 first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
4703 /* If the offset is outside of the variable, bail out. */
4704 if (offset >= start->fullsize)
4707 /* If we cannot reach offset from start, lookup the first field
4708 and start from there. */
4709 if (start->offset > offset)
4710 start = lookup_vi_for_tree (start->decl);
4714 /* We may not find a variable in the field list with the actual
4715 offset when when we have glommed a structure to a variable.
4716 In that case, however, offset should still be within the size
4718 if (offset >= start->offset
4719 && (offset - start->offset) < start->size)
4728 /* Find the first varinfo in the same variable as START that overlaps with
4729 OFFSET. If there is no such varinfo the varinfo directly preceding
4730 OFFSET is returned. */
4733 first_or_preceding_vi_for_offset (varinfo_t start,
4734 unsigned HOST_WIDE_INT offset)
4736 /* If we cannot reach offset from start, lookup the first field
4737 and start from there. */
4738 if (start->offset > offset)
4739 start = lookup_vi_for_tree (start->decl);
4741 /* We may not find a variable in the field list with the actual
4742 offset when when we have glommed a structure to a variable.
4743 In that case, however, offset should still be within the size
4745 If we got beyond the offset we look for return the field
4746 directly preceding offset which may be the last field. */
4748 && offset >= start->offset
4749 && !((offset - start->offset) < start->size))
4750 start = start->next;
4756 /* This structure is used during pushing fields onto the fieldstack
4757 to track the offset of the field, since bitpos_of_field gives it
4758 relative to its immediate containing type, and we want it relative
4759 to the ultimate containing object. */
4763 /* Offset from the base of the base containing object to this field. */
4764 HOST_WIDE_INT offset;
4766 /* Size, in bits, of the field. */
4767 unsigned HOST_WIDE_INT size;
4769 unsigned has_unknown_size : 1;
4771 unsigned may_have_pointers : 1;
4773 unsigned only_restrict_pointers : 1;
4775 typedef struct fieldoff fieldoff_s;
4777 DEF_VEC_O(fieldoff_s);
4778 DEF_VEC_ALLOC_O(fieldoff_s,heap);
4780 /* qsort comparison function for two fieldoff's PA and PB */
4783 fieldoff_compare (const void *pa, const void *pb)
4785 const fieldoff_s *foa = (const fieldoff_s *)pa;
4786 const fieldoff_s *fob = (const fieldoff_s *)pb;
4787 unsigned HOST_WIDE_INT foasize, fobsize;
4789 if (foa->offset < fob->offset)
4791 else if (foa->offset > fob->offset)
4794 foasize = foa->size;
4795 fobsize = fob->size;
4796 if (foasize < fobsize)
4798 else if (foasize > fobsize)
4803 /* Sort a fieldstack according to the field offset and sizes. */
4805 sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
4807 qsort (VEC_address (fieldoff_s, fieldstack),
4808 VEC_length (fieldoff_s, fieldstack),
4809 sizeof (fieldoff_s),
4813 /* Return true if V is a tree that we can have subvars for.
4814 Normally, this is any aggregate type. Also complex
4815 types which are not gimple registers can have subvars. */
4818 var_can_have_subvars (const_tree v)
4820 /* Volatile variables should never have subvars. */
4821 if (TREE_THIS_VOLATILE (v))
4824 /* Non decls or memory tags can never have subvars. */
4828 /* Aggregates without overlapping fields can have subvars. */
4829 if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE)
4835 /* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
4836 the fields of TYPE onto fieldstack, recording their offsets along
4839 OFFSET is used to keep track of the offset in this entire
4840 structure, rather than just the immediately containing structure.
4841 Returns false if the caller is supposed to handle the field we
4845 push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
4846 HOST_WIDE_INT offset)
4849 bool empty_p = true;
4851 if (TREE_CODE (type) != RECORD_TYPE)
4854 /* If the vector of fields is growing too big, bail out early.
4855 Callers check for VEC_length <= MAX_FIELDS_FOR_FIELD_SENSITIVE, make
4857 if (VEC_length (fieldoff_s, *fieldstack) > MAX_FIELDS_FOR_FIELD_SENSITIVE)
4860 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4861 if (TREE_CODE (field) == FIELD_DECL)
4864 HOST_WIDE_INT foff = bitpos_of_field (field);
4866 if (!var_can_have_subvars (field)
4867 || TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE
4868 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
4870 else if (!push_fields_onto_fieldstack
4871 (TREE_TYPE (field), fieldstack, offset + foff)
4872 && (DECL_SIZE (field)
4873 && !integer_zerop (DECL_SIZE (field))))
4874 /* Empty structures may have actual size, like in C++. So
4875 see if we didn't push any subfields and the size is
4876 nonzero, push the field onto the stack. */
4881 fieldoff_s *pair = NULL;
4882 bool has_unknown_size = false;
4884 if (!VEC_empty (fieldoff_s, *fieldstack))
4885 pair = VEC_last (fieldoff_s, *fieldstack);
4887 if (!DECL_SIZE (field)
4888 || !host_integerp (DECL_SIZE (field), 1))
4889 has_unknown_size = true;
4891 /* If adjacent fields do not contain pointers merge them. */
4893 && !pair->may_have_pointers
4894 && !pair->has_unknown_size
4895 && !has_unknown_size
4896 && pair->offset + (HOST_WIDE_INT)pair->size == offset + foff
4897 && !could_have_pointers (field))
4899 pair->size += TREE_INT_CST_LOW (DECL_SIZE (field));
4903 pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
4904 pair->offset = offset + foff;
4905 pair->has_unknown_size = has_unknown_size;
4906 if (!has_unknown_size)
4907 pair->size = TREE_INT_CST_LOW (DECL_SIZE (field));
4910 pair->may_have_pointers = could_have_pointers (field);
4911 pair->only_restrict_pointers
4912 = (!has_unknown_size
4913 && POINTER_TYPE_P (TREE_TYPE (field))
4914 && TYPE_RESTRICT (TREE_TYPE (field)));
4924 /* Count the number of arguments DECL has, and set IS_VARARGS to true
4925 if it is a varargs function. */
4928 count_num_arguments (tree decl, bool *is_varargs)
4930 unsigned int num = 0;
4933 /* Capture named arguments for K&R functions. They do not
4934 have a prototype and thus no TYPE_ARG_TYPES. */
4935 for (t = DECL_ARGUMENTS (decl); t; t = TREE_CHAIN (t))
4938 /* Check if the function has variadic arguments. */
4939 for (t = TYPE_ARG_TYPES (TREE_TYPE (decl)); t; t = TREE_CHAIN (t))
4940 if (TREE_VALUE (t) == void_type_node)
4948 /* Creation function node for DECL, using NAME, and return the index
4949 of the variable we've created for the function. */
4952 create_function_info_for (tree decl, const char *name)
4954 struct function *fn = DECL_STRUCT_FUNCTION (decl);
4955 varinfo_t vi, prev_vi;
4958 bool is_varargs = false;
4959 unsigned int num_args = count_num_arguments (decl, &is_varargs);
4961 /* Create the variable info. */
4963 vi = new_var_info (decl, name);
4966 vi->fullsize = fi_parm_base + num_args;
4968 vi->may_have_pointers = false;
4971 insert_vi_for_tree (vi->decl, vi);
4975 /* Create a variable for things the function clobbers and one for
4976 things the function uses. */
4978 varinfo_t clobbervi, usevi;
4979 const char *newname;
4982 asprintf (&tempname, "%s.clobber", name);
4983 newname = ggc_strdup (tempname);
4986 clobbervi = new_var_info (NULL, newname);
4987 clobbervi->offset = fi_clobbers;
4988 clobbervi->size = 1;
4989 clobbervi->fullsize = vi->fullsize;
4990 clobbervi->is_full_var = true;
4991 clobbervi->is_global_var = false;
4992 gcc_assert (prev_vi->offset < clobbervi->offset);
4993 prev_vi->next = clobbervi;
4994 prev_vi = clobbervi;
4996 asprintf (&tempname, "%s.use", name);
4997 newname = ggc_strdup (tempname);
5000 usevi = new_var_info (NULL, newname);
5001 usevi->offset = fi_uses;
5003 usevi->fullsize = vi->fullsize;
5004 usevi->is_full_var = true;
5005 usevi->is_global_var = false;
5006 gcc_assert (prev_vi->offset < usevi->offset);
5007 prev_vi->next = usevi;
5011 /* And one for the static chain. */
5012 if (fn->static_chain_decl != NULL_TREE)
5015 const char *newname;
5018 asprintf (&tempname, "%s.chain", name);
5019 newname = ggc_strdup (tempname);
5022 chainvi = new_var_info (fn->static_chain_decl, newname);
5023 chainvi->offset = fi_static_chain;
5025 chainvi->fullsize = vi->fullsize;
5026 chainvi->is_full_var = true;
5027 chainvi->is_global_var = false;
5028 gcc_assert (prev_vi->offset < chainvi->offset);
5029 prev_vi->next = chainvi;
5031 insert_vi_for_tree (fn->static_chain_decl, chainvi);
5034 /* Create a variable for the return var. */
5035 if (DECL_RESULT (decl) != NULL
5036 || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
5039 const char *newname;
5041 tree resultdecl = decl;
5043 if (DECL_RESULT (decl))
5044 resultdecl = DECL_RESULT (decl);
5046 asprintf (&tempname, "%s.result", name);
5047 newname = ggc_strdup (tempname);
5050 resultvi = new_var_info (resultdecl, newname);
5051 resultvi->offset = fi_result;
5053 resultvi->fullsize = vi->fullsize;
5054 resultvi->is_full_var = true;
5055 if (DECL_RESULT (decl))
5056 resultvi->may_have_pointers = could_have_pointers (DECL_RESULT (decl));
5057 gcc_assert (prev_vi->offset < resultvi->offset);
5058 prev_vi->next = resultvi;
5060 if (DECL_RESULT (decl))
5061 insert_vi_for_tree (DECL_RESULT (decl), resultvi);
5064 /* Set up variables for each argument. */
5065 arg = DECL_ARGUMENTS (decl);
5066 for (i = 0; i < num_args; i++)
5069 const char *newname;
5071 tree argdecl = decl;
5076 asprintf (&tempname, "%s.arg%d", name, i);
5077 newname = ggc_strdup (tempname);
5080 argvi = new_var_info (argdecl, newname);
5081 argvi->offset = fi_parm_base + i;
5083 argvi->is_full_var = true;
5084 argvi->fullsize = vi->fullsize;
5086 argvi->may_have_pointers = could_have_pointers (arg);
5087 gcc_assert (prev_vi->offset < argvi->offset);
5088 prev_vi->next = argvi;
5092 insert_vi_for_tree (arg, argvi);
5093 arg = TREE_CHAIN (arg);
5097 /* Add one representative for all further args. */
5101 const char *newname;
5105 asprintf (&tempname, "%s.varargs", name);
5106 newname = ggc_strdup (tempname);
5109 /* We need sth that can be pointed to for va_start. */
5110 decl = create_tmp_var_raw (ptr_type_node, name);
5113 argvi = new_var_info (decl, newname);
5114 argvi->offset = fi_parm_base + num_args;
5116 argvi->is_full_var = true;
5117 argvi->is_heap_var = true;
5118 argvi->fullsize = vi->fullsize;
5119 gcc_assert (prev_vi->offset < argvi->offset);
5120 prev_vi->next = argvi;
5128 /* Return true if FIELDSTACK contains fields that overlap.
5129 FIELDSTACK is assumed to be sorted by offset. */
5132 check_for_overlaps (VEC (fieldoff_s,heap) *fieldstack)
5134 fieldoff_s *fo = NULL;
5136 HOST_WIDE_INT lastoffset = -1;
5138 for (i = 0; VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
5140 if (fo->offset == lastoffset)
5142 lastoffset = fo->offset;
5147 /* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
5148 This will also create any varinfo structures necessary for fields
5152 create_variable_info_for_1 (tree decl, const char *name)
5154 varinfo_t vi, newvi;
5155 tree decl_type = TREE_TYPE (decl);
5156 tree declsize = DECL_P (decl) ? DECL_SIZE (decl) : TYPE_SIZE (decl_type);
5157 VEC (fieldoff_s,heap) *fieldstack = NULL;
5162 || !host_integerp (declsize, 1))
5164 vi = new_var_info (decl, name);
5168 vi->is_unknown_size_var = true;
5169 vi->is_full_var = true;
5170 vi->may_have_pointers = could_have_pointers (decl);
5174 /* Collect field information. */
5175 if (use_field_sensitive
5176 && var_can_have_subvars (decl)
5177 /* ??? Force us to not use subfields for global initializers
5178 in IPA mode. Else we'd have to parse arbitrary initializers. */
5180 && is_global_var (decl)
5181 && DECL_INITIAL (decl)))
5183 fieldoff_s *fo = NULL;
5184 bool notokay = false;
5187 push_fields_onto_fieldstack (decl_type, &fieldstack, 0);
5189 for (i = 0; !notokay && VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
5190 if (fo->has_unknown_size
5197 /* We can't sort them if we have a field with a variable sized type,
5198 which will make notokay = true. In that case, we are going to return
5199 without creating varinfos for the fields anyway, so sorting them is a
5203 sort_fieldstack (fieldstack);
5204 /* Due to some C++ FE issues, like PR 22488, we might end up
5205 what appear to be overlapping fields even though they,
5206 in reality, do not overlap. Until the C++ FE is fixed,
5207 we will simply disable field-sensitivity for these cases. */
5208 notokay = check_for_overlaps (fieldstack);
5212 VEC_free (fieldoff_s, heap, fieldstack);
5215 /* If we didn't end up collecting sub-variables create a full
5216 variable for the decl. */
5217 if (VEC_length (fieldoff_s, fieldstack) <= 1
5218 || VEC_length (fieldoff_s, fieldstack) > MAX_FIELDS_FOR_FIELD_SENSITIVE)
5220 vi = new_var_info (decl, name);
5222 vi->may_have_pointers = could_have_pointers (decl);
5223 vi->fullsize = TREE_INT_CST_LOW (declsize);
5224 vi->size = vi->fullsize;
5225 vi->is_full_var = true;
5226 VEC_free (fieldoff_s, heap, fieldstack);
5230 vi = new_var_info (decl, name);
5231 vi->fullsize = TREE_INT_CST_LOW (declsize);
5232 for (i = 0, newvi = vi;
5233 VEC_iterate (fieldoff_s, fieldstack, i, fo);
5234 ++i, newvi = newvi->next)
5236 const char *newname = "NULL";
5241 asprintf (&tempname, "%s." HOST_WIDE_INT_PRINT_DEC
5242 "+" HOST_WIDE_INT_PRINT_DEC, name, fo->offset, fo->size);
5243 newname = ggc_strdup (tempname);
5246 newvi->name = newname;
5247 newvi->offset = fo->offset;
5248 newvi->size = fo->size;
5249 newvi->fullsize = vi->fullsize;
5250 newvi->may_have_pointers = fo->may_have_pointers;
5251 newvi->only_restrict_pointers = fo->only_restrict_pointers;
5252 if (i + 1 < VEC_length (fieldoff_s, fieldstack))
5253 newvi->next = new_var_info (decl, name);
5256 VEC_free (fieldoff_s, heap, fieldstack);
5262 create_variable_info_for (tree decl, const char *name)
5264 varinfo_t vi = create_variable_info_for_1 (decl, name);
5265 unsigned int id = vi->id;
5267 insert_vi_for_tree (decl, vi);
5269 /* Create initial constraints for globals. */
5270 for (; vi; vi = vi->next)
5272 if (!vi->may_have_pointers
5273 || !vi->is_global_var)
5276 /* Mark global restrict qualified pointers. */
5277 if ((POINTER_TYPE_P (TREE_TYPE (decl))
5278 && TYPE_RESTRICT (TREE_TYPE (decl)))
5279 || vi->only_restrict_pointers)
5280 make_constraint_from_restrict (vi, "GLOBAL_RESTRICT");
5282 /* For escaped variables initialize them from nonlocal. */
5284 || DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
5285 make_copy_constraint (vi, nonlocal_id);
5287 /* If this is a global variable with an initializer and we are in
5288 IPA mode generate constraints for it. In non-IPA mode
5289 the initializer from nonlocal is all we need. */
5291 && DECL_INITIAL (decl))
5293 VEC (ce_s, heap) *rhsc = NULL;
5294 struct constraint_expr lhs, *rhsp;
5296 get_constraint_for (DECL_INITIAL (decl), &rhsc);
5300 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
5301 process_constraint (new_constraint (lhs, *rhsp));
5302 /* If this is a variable that escapes from the unit
5303 the initializer escapes as well. */
5304 if (DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
5306 lhs.var = escaped_id;
5309 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
5310 process_constraint (new_constraint (lhs, *rhsp));
5312 VEC_free (ce_s, heap, rhsc);
5319 /* Print out the points-to solution for VAR to FILE. */
5322 dump_solution_for_var (FILE *file, unsigned int var)
5324 varinfo_t vi = get_varinfo (var);
5328 /* Dump the solution for unified vars anyway, this avoids difficulties
5329 in scanning dumps in the testsuite. */
5330 fprintf (file, "%s = { ", vi->name);
5331 vi = get_varinfo (find (var));
5332 EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
5333 fprintf (file, "%s ", get_varinfo (i)->name);
5334 fprintf (file, "}");
5336 /* But note when the variable was unified. */
5338 fprintf (file, " same as %s", vi->name);
5340 fprintf (file, "\n");
5343 /* Print the points-to solution for VAR to stdout. */
5346 debug_solution_for_var (unsigned int var)
5348 dump_solution_for_var (stdout, var);
5351 /* Create varinfo structures for all of the variables in the
5352 function for intraprocedural mode. */
5355 intra_create_variable_infos (void)
5359 /* For each incoming pointer argument arg, create the constraint ARG
5360 = NONLOCAL or a dummy variable if it is a restrict qualified
5361 passed-by-reference argument. */
5362 for (t = DECL_ARGUMENTS (current_function_decl); t; t = TREE_CHAIN (t))
5366 if (!could_have_pointers (t))
5369 /* For restrict qualified pointers to objects passed by
5370 reference build a real representative for the pointed-to object. */
5371 if (DECL_BY_REFERENCE (t)
5372 && POINTER_TYPE_P (TREE_TYPE (t))
5373 && TYPE_RESTRICT (TREE_TYPE (t)))
5375 struct constraint_expr lhsc, rhsc;
5377 tree heapvar = heapvar_lookup (t, 0);
5378 if (heapvar == NULL_TREE)
5381 heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)),
5383 DECL_EXTERNAL (heapvar) = 1;
5384 heapvar_insert (t, 0, heapvar);
5385 ann = get_var_ann (heapvar);
5386 ann->is_heapvar = 1;
5388 if (gimple_referenced_vars (cfun))
5389 add_referenced_var (heapvar);
5390 lhsc.var = get_vi_for_tree (t)->id;
5393 rhsc.var = (vi = get_vi_for_tree (heapvar))->id;
5394 rhsc.type = ADDRESSOF;
5396 process_constraint (new_constraint (lhsc, rhsc));
5397 vi->is_restrict_var = 1;
5401 for (p = get_vi_for_tree (t); p; p = p->next)
5403 if (p->may_have_pointers)
5404 make_constraint_from (p, nonlocal_id);
5405 if (p->only_restrict_pointers)
5406 make_constraint_from_restrict (p, "PARM_RESTRICT");
5408 if (POINTER_TYPE_P (TREE_TYPE (t))
5409 && TYPE_RESTRICT (TREE_TYPE (t)))
5410 make_constraint_from_restrict (get_vi_for_tree (t), "PARM_RESTRICT");
5413 /* Add a constraint for a result decl that is passed by reference. */
5414 if (DECL_RESULT (cfun->decl)
5415 && DECL_BY_REFERENCE (DECL_RESULT (cfun->decl)))
5417 varinfo_t p, result_vi = get_vi_for_tree (DECL_RESULT (cfun->decl));
5419 for (p = result_vi; p; p = p->next)
5420 make_constraint_from (p, nonlocal_id);
5423 /* Add a constraint for the incoming static chain parameter. */
5424 if (cfun->static_chain_decl != NULL_TREE)
5426 varinfo_t p, chain_vi = get_vi_for_tree (cfun->static_chain_decl);
5428 for (p = chain_vi; p; p = p->next)
5429 make_constraint_from (p, nonlocal_id);
5433 /* Structure used to put solution bitmaps in a hashtable so they can
5434 be shared among variables with the same points-to set. */
5436 typedef struct shared_bitmap_info
5440 } *shared_bitmap_info_t;
5441 typedef const struct shared_bitmap_info *const_shared_bitmap_info_t;
5443 static htab_t shared_bitmap_table;
5445 /* Hash function for a shared_bitmap_info_t */
5448 shared_bitmap_hash (const void *p)
5450 const_shared_bitmap_info_t const bi = (const_shared_bitmap_info_t) p;
5451 return bi->hashcode;
5454 /* Equality function for two shared_bitmap_info_t's. */
5457 shared_bitmap_eq (const void *p1, const void *p2)
5459 const_shared_bitmap_info_t const sbi1 = (const_shared_bitmap_info_t) p1;
5460 const_shared_bitmap_info_t const sbi2 = (const_shared_bitmap_info_t) p2;
5461 return bitmap_equal_p (sbi1->pt_vars, sbi2->pt_vars);
5464 /* Lookup a bitmap in the shared bitmap hashtable, and return an already
5465 existing instance if there is one, NULL otherwise. */
5468 shared_bitmap_lookup (bitmap pt_vars)
5471 struct shared_bitmap_info sbi;
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, NO_INSERT);
5481 return ((shared_bitmap_info_t) *slot)->pt_vars;
5485 /* Add a bitmap to the shared bitmap hashtable. */
5488 shared_bitmap_add (bitmap pt_vars)
5491 shared_bitmap_info_t sbi = XNEW (struct shared_bitmap_info);
5493 sbi->pt_vars = pt_vars;
5494 sbi->hashcode = bitmap_hash (pt_vars);
5496 slot = htab_find_slot_with_hash (shared_bitmap_table, sbi,
5497 sbi->hashcode, INSERT);
5498 gcc_assert (!*slot);
5499 *slot = (void *) sbi;
5503 /* Set bits in INTO corresponding to the variable uids in solution set FROM. */
5506 set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt)
5511 EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
5513 varinfo_t vi = get_varinfo (i);
5515 /* The only artificial variables that are allowed in a may-alias
5516 set are heap variables. */
5517 if (vi->is_artificial_var && !vi->is_heap_var)
5520 if (TREE_CODE (vi->decl) == VAR_DECL
5521 || TREE_CODE (vi->decl) == PARM_DECL
5522 || TREE_CODE (vi->decl) == RESULT_DECL)
5524 /* If we are in IPA mode we will not recompute points-to
5525 sets after inlining so make sure they stay valid. */
5527 && !DECL_PT_UID_SET_P (vi->decl))
5528 SET_DECL_PT_UID (vi->decl, DECL_UID (vi->decl));
5530 /* Add the decl to the points-to set. Note that the points-to
5531 set contains global variables. */
5532 bitmap_set_bit (into, DECL_PT_UID (vi->decl));
5533 if (vi->is_global_var)
5534 pt->vars_contains_global = true;
5540 /* Compute the points-to solution *PT for the variable VI. */
5543 find_what_var_points_to (varinfo_t orig_vi, struct pt_solution *pt)
5547 bitmap finished_solution;
5551 memset (pt, 0, sizeof (struct pt_solution));
5553 /* This variable may have been collapsed, let's get the real
5555 vi = get_varinfo (find (orig_vi->id));
5557 /* Translate artificial variables into SSA_NAME_PTR_INFO
5559 EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
5561 varinfo_t vi = get_varinfo (i);
5563 if (vi->is_artificial_var)
5565 if (vi->id == nothing_id)
5567 else if (vi->id == escaped_id)
5570 pt->ipa_escaped = 1;
5574 else if (vi->id == nonlocal_id)
5576 else if (vi->is_heap_var)
5577 /* We represent heapvars in the points-to set properly. */
5579 else if (vi->id == readonly_id)
5582 else if (vi->id == anything_id
5583 || vi->id == integer_id)
5586 if (vi->is_restrict_var)
5587 pt->vars_contains_restrict = true;
5590 /* Instead of doing extra work, simply do not create
5591 elaborate points-to information for pt_anything pointers. */
5593 && (orig_vi->is_artificial_var
5594 || !pt->vars_contains_restrict))
5597 /* Share the final set of variables when possible. */
5598 finished_solution = BITMAP_GGC_ALLOC ();
5599 stats.points_to_sets_created++;
5601 set_uids_in_ptset (finished_solution, vi->solution, pt);
5602 result = shared_bitmap_lookup (finished_solution);
5605 shared_bitmap_add (finished_solution);
5606 pt->vars = finished_solution;
5611 bitmap_clear (finished_solution);
5615 /* Given a pointer variable P, fill in its points-to set. */
5618 find_what_p_points_to (tree p)
5620 struct ptr_info_def *pi;
5624 /* For parameters, get at the points-to set for the actual parm
5626 if (TREE_CODE (p) == SSA_NAME
5627 && TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL
5628 && SSA_NAME_IS_DEFAULT_DEF (p))
5629 lookup_p = SSA_NAME_VAR (p);
5631 vi = lookup_vi_for_tree (lookup_p);
5635 pi = get_ptr_info (p);
5636 find_what_var_points_to (vi, &pi->pt);
5640 /* Query statistics for points-to solutions. */
5643 unsigned HOST_WIDE_INT pt_solution_includes_may_alias;
5644 unsigned HOST_WIDE_INT pt_solution_includes_no_alias;
5645 unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias;
5646 unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias;
5650 dump_pta_stats (FILE *s)
5652 fprintf (s, "\nPTA query stats:\n");
5653 fprintf (s, " pt_solution_includes: "
5654 HOST_WIDE_INT_PRINT_DEC" disambiguations, "
5655 HOST_WIDE_INT_PRINT_DEC" queries\n",
5656 pta_stats.pt_solution_includes_no_alias,
5657 pta_stats.pt_solution_includes_no_alias
5658 + pta_stats.pt_solution_includes_may_alias);
5659 fprintf (s, " pt_solutions_intersect: "
5660 HOST_WIDE_INT_PRINT_DEC" disambiguations, "
5661 HOST_WIDE_INT_PRINT_DEC" queries\n",
5662 pta_stats.pt_solutions_intersect_no_alias,
5663 pta_stats.pt_solutions_intersect_no_alias
5664 + pta_stats.pt_solutions_intersect_may_alias);
5668 /* Reset the points-to solution *PT to a conservative default
5669 (point to anything). */
5672 pt_solution_reset (struct pt_solution *pt)
5674 memset (pt, 0, sizeof (struct pt_solution));
5675 pt->anything = true;
5678 /* Set the points-to solution *PT to point only to the variables
5679 in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
5680 global variables and VARS_CONTAINS_RESTRICT specifies whether
5681 it contains restrict tag variables. */
5684 pt_solution_set (struct pt_solution *pt, bitmap vars,
5685 bool vars_contains_global, bool vars_contains_restrict)
5687 memset (pt, 0, sizeof (struct pt_solution));
5689 pt->vars_contains_global = vars_contains_global;
5690 pt->vars_contains_restrict = vars_contains_restrict;
5693 /* Computes the union of the points-to solutions *DEST and *SRC and
5694 stores the result in *DEST. This changes the points-to bitmap
5695 of *DEST and thus may not be used if that might be shared.
5696 The points-to bitmap of *SRC and *DEST will not be shared after
5697 this function if they were not before. */
5700 pt_solution_ior_into (struct pt_solution *dest, struct pt_solution *src)
5702 dest->anything |= src->anything;
5705 pt_solution_reset (dest);
5709 dest->nonlocal |= src->nonlocal;
5710 dest->escaped |= src->escaped;
5711 dest->ipa_escaped |= src->ipa_escaped;
5712 dest->null |= src->null;
5713 dest->vars_contains_global |= src->vars_contains_global;
5714 dest->vars_contains_restrict |= src->vars_contains_restrict;
5719 dest->vars = BITMAP_GGC_ALLOC ();
5720 bitmap_ior_into (dest->vars, src->vars);
5723 /* Return true if the points-to solution *PT is empty. */
5726 pt_solution_empty_p (struct pt_solution *pt)
5733 && !bitmap_empty_p (pt->vars))
5736 /* If the solution includes ESCAPED, check if that is empty. */
5738 && !pt_solution_empty_p (&cfun->gimple_df->escaped))
5741 /* If the solution includes ESCAPED, check if that is empty. */
5743 && !pt_solution_empty_p (&ipa_escaped_pt))
5749 /* Return true if the points-to solution *PT includes global memory. */
5752 pt_solution_includes_global (struct pt_solution *pt)
5756 || pt->vars_contains_global)
5760 return pt_solution_includes_global (&cfun->gimple_df->escaped);
5762 if (pt->ipa_escaped)
5763 return pt_solution_includes_global (&ipa_escaped_pt);
5765 /* ??? This predicate is not correct for the IPA-PTA solution
5766 as we do not properly distinguish between unit escape points
5767 and global variables. */
5768 if (cfun->gimple_df->ipa_pta)
5774 /* Return true if the points-to solution *PT includes the variable
5775 declaration DECL. */
5778 pt_solution_includes_1 (struct pt_solution *pt, const_tree decl)
5784 && is_global_var (decl))
5788 && bitmap_bit_p (pt->vars, DECL_PT_UID (decl)))
5791 /* If the solution includes ESCAPED, check it. */
5793 && pt_solution_includes_1 (&cfun->gimple_df->escaped, decl))
5796 /* If the solution includes ESCAPED, check it. */
5798 && pt_solution_includes_1 (&ipa_escaped_pt, decl))
5805 pt_solution_includes (struct pt_solution *pt, const_tree decl)
5807 bool res = pt_solution_includes_1 (pt, decl);
5809 ++pta_stats.pt_solution_includes_may_alias;
5811 ++pta_stats.pt_solution_includes_no_alias;
5815 /* Return true if both points-to solutions PT1 and PT2 have a non-empty
5819 pt_solutions_intersect_1 (struct pt_solution *pt1, struct pt_solution *pt2)
5821 if (pt1->anything || pt2->anything)
5824 /* If either points to unknown global memory and the other points to
5825 any global memory they alias. */
5828 || pt2->vars_contains_global))
5830 && pt1->vars_contains_global))
5833 /* Check the escaped solution if required. */
5834 if ((pt1->escaped || pt2->escaped)
5835 && !pt_solution_empty_p (&cfun->gimple_df->escaped))
5837 /* If both point to escaped memory and that solution
5838 is not empty they alias. */
5839 if (pt1->escaped && pt2->escaped)
5842 /* If either points to escaped memory see if the escaped solution
5843 intersects with the other. */
5845 && pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt2))
5847 && pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt1)))
5851 /* Check the escaped solution if required.
5852 ??? Do we need to check the local against the IPA escaped sets? */
5853 if ((pt1->ipa_escaped || pt2->ipa_escaped)
5854 && !pt_solution_empty_p (&ipa_escaped_pt))
5856 /* If both point to escaped memory and that solution
5857 is not empty they alias. */
5858 if (pt1->ipa_escaped && pt2->ipa_escaped)
5861 /* If either points to escaped memory see if the escaped solution
5862 intersects with the other. */
5863 if ((pt1->ipa_escaped
5864 && pt_solutions_intersect_1 (&ipa_escaped_pt, pt2))
5865 || (pt2->ipa_escaped
5866 && pt_solutions_intersect_1 (&ipa_escaped_pt, pt1)))
5870 /* Now both pointers alias if their points-to solution intersects. */
5873 && bitmap_intersect_p (pt1->vars, pt2->vars));
5877 pt_solutions_intersect (struct pt_solution *pt1, struct pt_solution *pt2)
5879 bool res = pt_solutions_intersect_1 (pt1, pt2);
5881 ++pta_stats.pt_solutions_intersect_may_alias;
5883 ++pta_stats.pt_solutions_intersect_no_alias;
5887 /* Return true if both points-to solutions PT1 and PT2 for two restrict
5888 qualified pointers are possibly based on the same pointer. */
5891 pt_solutions_same_restrict_base (struct pt_solution *pt1,
5892 struct pt_solution *pt2)
5894 /* If we deal with points-to solutions of two restrict qualified
5895 pointers solely rely on the pointed-to variable bitmap intersection.
5896 For two pointers that are based on each other the bitmaps will
5898 if (pt1->vars_contains_restrict
5899 && pt2->vars_contains_restrict)
5901 gcc_assert (pt1->vars && pt2->vars);
5902 return bitmap_intersect_p (pt1->vars, pt2->vars);
5909 /* Dump points-to information to OUTFILE. */
5912 dump_sa_points_to_info (FILE *outfile)
5916 fprintf (outfile, "\nPoints-to sets\n\n");
5918 if (dump_flags & TDF_STATS)
5920 fprintf (outfile, "Stats:\n");
5921 fprintf (outfile, "Total vars: %d\n", stats.total_vars);
5922 fprintf (outfile, "Non-pointer vars: %d\n",
5923 stats.nonpointer_vars);
5924 fprintf (outfile, "Statically unified vars: %d\n",
5925 stats.unified_vars_static);
5926 fprintf (outfile, "Dynamically unified vars: %d\n",
5927 stats.unified_vars_dynamic);
5928 fprintf (outfile, "Iterations: %d\n", stats.iterations);
5929 fprintf (outfile, "Number of edges: %d\n", stats.num_edges);
5930 fprintf (outfile, "Number of implicit edges: %d\n",
5931 stats.num_implicit_edges);
5934 for (i = 0; i < VEC_length (varinfo_t, varmap); i++)
5936 varinfo_t vi = get_varinfo (i);
5937 if (!vi->may_have_pointers)
5939 dump_solution_for_var (outfile, i);
5944 /* Debug points-to information to stderr. */
5947 debug_sa_points_to_info (void)
5949 dump_sa_points_to_info (stderr);
5953 /* Initialize the always-existing constraint variables for NULL
5954 ANYTHING, READONLY, and INTEGER */
5957 init_base_vars (void)
5959 struct constraint_expr lhs, rhs;
5960 varinfo_t var_anything;
5961 varinfo_t var_nothing;
5962 varinfo_t var_readonly;
5963 varinfo_t var_escaped;
5964 varinfo_t var_nonlocal;
5965 varinfo_t var_storedanything;
5966 varinfo_t var_integer;
5968 /* Create the NULL variable, used to represent that a variable points
5970 var_nothing = new_var_info (NULL_TREE, "NULL");
5971 gcc_assert (var_nothing->id == nothing_id);
5972 var_nothing->is_artificial_var = 1;
5973 var_nothing->offset = 0;
5974 var_nothing->size = ~0;
5975 var_nothing->fullsize = ~0;
5976 var_nothing->is_special_var = 1;
5977 var_nothing->may_have_pointers = 0;
5978 var_nothing->is_global_var = 0;
5980 /* Create the ANYTHING variable, used to represent that a variable
5981 points to some unknown piece of memory. */
5982 var_anything = new_var_info (NULL_TREE, "ANYTHING");
5983 gcc_assert (var_anything->id == anything_id);
5984 var_anything->is_artificial_var = 1;
5985 var_anything->size = ~0;
5986 var_anything->offset = 0;
5987 var_anything->next = NULL;
5988 var_anything->fullsize = ~0;
5989 var_anything->is_special_var = 1;
5991 /* Anything points to anything. This makes deref constraints just
5992 work in the presence of linked list and other p = *p type loops,
5993 by saying that *ANYTHING = ANYTHING. */
5995 lhs.var = anything_id;
5997 rhs.type = ADDRESSOF;
5998 rhs.var = anything_id;
6001 /* This specifically does not use process_constraint because
6002 process_constraint ignores all anything = anything constraints, since all
6003 but this one are redundant. */
6004 VEC_safe_push (constraint_t, heap, constraints, new_constraint (lhs, rhs));
6006 /* Create the READONLY variable, used to represent that a variable
6007 points to readonly memory. */
6008 var_readonly = new_var_info (NULL_TREE, "READONLY");
6009 gcc_assert (var_readonly->id == readonly_id);
6010 var_readonly->is_artificial_var = 1;
6011 var_readonly->offset = 0;
6012 var_readonly->size = ~0;
6013 var_readonly->fullsize = ~0;
6014 var_readonly->next = NULL;
6015 var_readonly->is_special_var = 1;
6017 /* readonly memory points to anything, in order to make deref
6018 easier. In reality, it points to anything the particular
6019 readonly variable can point to, but we don't track this
6022 lhs.var = readonly_id;
6024 rhs.type = ADDRESSOF;
6025 rhs.var = readonly_id; /* FIXME */
6027 process_constraint (new_constraint (lhs, rhs));
6029 /* Create the ESCAPED variable, used to represent the set of escaped
6031 var_escaped = new_var_info (NULL_TREE, "ESCAPED");
6032 gcc_assert (var_escaped->id == escaped_id);
6033 var_escaped->is_artificial_var = 1;
6034 var_escaped->offset = 0;
6035 var_escaped->size = ~0;
6036 var_escaped->fullsize = ~0;
6037 var_escaped->is_special_var = 0;
6039 /* Create the NONLOCAL variable, used to represent the set of nonlocal
6041 var_nonlocal = new_var_info (NULL_TREE, "NONLOCAL");
6042 gcc_assert (var_nonlocal->id == nonlocal_id);
6043 var_nonlocal->is_artificial_var = 1;
6044 var_nonlocal->offset = 0;
6045 var_nonlocal->size = ~0;
6046 var_nonlocal->fullsize = ~0;
6047 var_nonlocal->is_special_var = 1;
6049 /* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
6051 lhs.var = escaped_id;
6054 rhs.var = escaped_id;
6056 process_constraint (new_constraint (lhs, rhs));
6058 /* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
6059 whole variable escapes. */
6061 lhs.var = escaped_id;
6064 rhs.var = escaped_id;
6065 rhs.offset = UNKNOWN_OFFSET;
6066 process_constraint (new_constraint (lhs, rhs));
6068 /* *ESCAPED = NONLOCAL. This is true because we have to assume
6069 everything pointed to by escaped points to what global memory can
6072 lhs.var = escaped_id;
6075 rhs.var = nonlocal_id;
6077 process_constraint (new_constraint (lhs, rhs));
6079 /* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
6080 global memory may point to global memory and escaped memory. */
6082 lhs.var = nonlocal_id;
6084 rhs.type = ADDRESSOF;
6085 rhs.var = nonlocal_id;
6087 process_constraint (new_constraint (lhs, rhs));
6088 rhs.type = ADDRESSOF;
6089 rhs.var = escaped_id;
6091 process_constraint (new_constraint (lhs, rhs));
6093 /* Create the STOREDANYTHING variable, used to represent the set of
6094 variables stored to *ANYTHING. */
6095 var_storedanything = new_var_info (NULL_TREE, "STOREDANYTHING");
6096 gcc_assert (var_storedanything->id == storedanything_id);
6097 var_storedanything->is_artificial_var = 1;
6098 var_storedanything->offset = 0;
6099 var_storedanything->size = ~0;
6100 var_storedanything->fullsize = ~0;
6101 var_storedanything->is_special_var = 0;
6103 /* Create the INTEGER variable, used to represent that a variable points
6104 to what an INTEGER "points to". */
6105 var_integer = new_var_info (NULL_TREE, "INTEGER");
6106 gcc_assert (var_integer->id == integer_id);
6107 var_integer->is_artificial_var = 1;
6108 var_integer->size = ~0;
6109 var_integer->fullsize = ~0;
6110 var_integer->offset = 0;
6111 var_integer->next = NULL;
6112 var_integer->is_special_var = 1;
6114 /* INTEGER = ANYTHING, because we don't know where a dereference of
6115 a random integer will point to. */
6117 lhs.var = integer_id;
6119 rhs.type = ADDRESSOF;
6120 rhs.var = anything_id;
6122 process_constraint (new_constraint (lhs, rhs));
6125 /* Initialize things necessary to perform PTA */
6128 init_alias_vars (void)
6130 use_field_sensitive = (MAX_FIELDS_FOR_FIELD_SENSITIVE > 1);
6132 bitmap_obstack_initialize (&pta_obstack);
6133 bitmap_obstack_initialize (&oldpta_obstack);
6134 bitmap_obstack_initialize (&predbitmap_obstack);
6136 constraint_pool = create_alloc_pool ("Constraint pool",
6137 sizeof (struct constraint), 30);
6138 variable_info_pool = create_alloc_pool ("Variable info pool",
6139 sizeof (struct variable_info), 30);
6140 constraints = VEC_alloc (constraint_t, heap, 8);
6141 varmap = VEC_alloc (varinfo_t, heap, 8);
6142 vi_for_tree = pointer_map_create ();
6143 call_stmt_vars = pointer_map_create ();
6145 memset (&stats, 0, sizeof (stats));
6146 shared_bitmap_table = htab_create (511, shared_bitmap_hash,
6147 shared_bitmap_eq, free);
6151 /* Remove the REF and ADDRESS edges from GRAPH, as well as all the
6152 predecessor edges. */
6155 remove_preds_and_fake_succs (constraint_graph_t graph)
6159 /* Clear the implicit ref and address nodes from the successor
6161 for (i = 0; i < FIRST_REF_NODE; i++)
6163 if (graph->succs[i])
6164 bitmap_clear_range (graph->succs[i], FIRST_REF_NODE,
6165 FIRST_REF_NODE * 2);
6168 /* Free the successor list for the non-ref nodes. */
6169 for (i = FIRST_REF_NODE; i < graph->size; i++)
6171 if (graph->succs[i])
6172 BITMAP_FREE (graph->succs[i]);
6175 /* Now reallocate the size of the successor list as, and blow away
6176 the predecessor bitmaps. */
6177 graph->size = VEC_length (varinfo_t, varmap);
6178 graph->succs = XRESIZEVEC (bitmap, graph->succs, graph->size);
6180 free (graph->implicit_preds);
6181 graph->implicit_preds = NULL;
6182 free (graph->preds);
6183 graph->preds = NULL;
6184 bitmap_obstack_release (&predbitmap_obstack);
6187 /* Initialize the heapvar for statement mapping. */
6190 init_alias_heapvars (void)
6192 if (!heapvar_for_stmt)
6193 heapvar_for_stmt = htab_create_ggc (11, tree_map_hash, heapvar_map_eq,
6197 /* Delete the heapvar for statement mapping. */
6200 delete_alias_heapvars (void)
6202 if (heapvar_for_stmt)
6203 htab_delete (heapvar_for_stmt);
6204 heapvar_for_stmt = NULL;
6207 /* Solve the constraint set. */
6210 solve_constraints (void)
6212 struct scc_info *si;
6216 "\nCollapsing static cycles and doing variable "
6219 init_graph (VEC_length (varinfo_t, varmap) * 2);
6222 fprintf (dump_file, "Building predecessor graph\n");
6223 build_pred_graph ();
6226 fprintf (dump_file, "Detecting pointer and location "
6228 si = perform_var_substitution (graph);
6231 fprintf (dump_file, "Rewriting constraints and unifying "
6233 rewrite_constraints (graph, si);
6235 build_succ_graph ();
6236 free_var_substitution_info (si);
6238 if (dump_file && (dump_flags & TDF_GRAPH))
6239 dump_constraint_graph (dump_file);
6241 move_complex_constraints (graph);
6244 fprintf (dump_file, "Uniting pointer but not location equivalent "
6246 unite_pointer_equivalences (graph);
6249 fprintf (dump_file, "Finding indirect cycles\n");
6250 find_indirect_cycles (graph);
6252 /* Implicit nodes and predecessors are no longer necessary at this
6254 remove_preds_and_fake_succs (graph);
6257 fprintf (dump_file, "Solving graph\n");
6259 solve_graph (graph);
6262 dump_sa_points_to_info (dump_file);
6265 /* Create points-to sets for the current function. See the comments
6266 at the start of the file for an algorithmic overview. */
6269 compute_points_to_sets (void)
6275 timevar_push (TV_TREE_PTA);
6278 init_alias_heapvars ();
6280 intra_create_variable_infos ();
6282 /* Now walk all statements and build the constraint set. */
6285 gimple_stmt_iterator gsi;
6287 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6289 gimple phi = gsi_stmt (gsi);
6291 if (is_gimple_reg (gimple_phi_result (phi)))
6292 find_func_aliases (phi);
6295 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6297 gimple stmt = gsi_stmt (gsi);
6299 find_func_aliases (stmt);
6305 fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
6306 dump_constraints (dump_file, 0);
6309 /* From the constraints compute the points-to sets. */
6310 solve_constraints ();
6312 /* Compute the points-to set for ESCAPED used for call-clobber analysis. */
6313 find_what_var_points_to (get_varinfo (escaped_id),
6314 &cfun->gimple_df->escaped);
6316 /* Make sure the ESCAPED solution (which is used as placeholder in
6317 other solutions) does not reference itself. This simplifies
6318 points-to solution queries. */
6319 cfun->gimple_df->escaped.escaped = 0;
6321 /* Mark escaped HEAP variables as global. */
6322 for (i = 0; VEC_iterate (varinfo_t, varmap, i, vi); ++i)
6324 && !vi->is_restrict_var
6325 && !vi->is_global_var)
6326 DECL_EXTERNAL (vi->decl) = vi->is_global_var
6327 = pt_solution_includes (&cfun->gimple_df->escaped, vi->decl);
6329 /* Compute the points-to sets for pointer SSA_NAMEs. */
6330 for (i = 0; i < num_ssa_names; ++i)
6332 tree ptr = ssa_name (i);
6334 && POINTER_TYPE_P (TREE_TYPE (ptr)))
6335 find_what_p_points_to (ptr);
6338 /* Compute the call-used/clobbered sets. */
6341 gimple_stmt_iterator gsi;
6343 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6345 gimple stmt = gsi_stmt (gsi);
6346 struct pt_solution *pt;
6347 if (!is_gimple_call (stmt))
6350 pt = gimple_call_use_set (stmt);
6351 if (gimple_call_flags (stmt) & ECF_CONST)
6352 memset (pt, 0, sizeof (struct pt_solution));
6353 else if ((vi = lookup_call_use_vi (stmt)) != NULL)
6355 find_what_var_points_to (vi, pt);
6356 /* Escaped (and thus nonlocal) variables are always
6357 implicitly used by calls. */
6358 /* ??? ESCAPED can be empty even though NONLOCAL
6365 /* If there is nothing special about this call then
6366 we have made everything that is used also escape. */
6367 *pt = cfun->gimple_df->escaped;
6371 pt = gimple_call_clobber_set (stmt);
6372 if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
6373 memset (pt, 0, sizeof (struct pt_solution));
6374 else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
6376 find_what_var_points_to (vi, pt);
6377 /* Escaped (and thus nonlocal) variables are always
6378 implicitly clobbered by calls. */
6379 /* ??? ESCAPED can be empty even though NONLOCAL
6386 /* If there is nothing special about this call then
6387 we have made everything that is used also escape. */
6388 *pt = cfun->gimple_df->escaped;
6394 timevar_pop (TV_TREE_PTA);
6398 /* Delete created points-to sets. */
6401 delete_points_to_sets (void)
6405 htab_delete (shared_bitmap_table);
6406 if (dump_file && (dump_flags & TDF_STATS))
6407 fprintf (dump_file, "Points to sets created:%d\n",
6408 stats.points_to_sets_created);
6410 pointer_map_destroy (vi_for_tree);
6411 pointer_map_destroy (call_stmt_vars);
6412 bitmap_obstack_release (&pta_obstack);
6413 VEC_free (constraint_t, heap, constraints);
6415 for (i = 0; i < graph->size; i++)
6416 VEC_free (constraint_t, heap, graph->complex[i]);
6417 free (graph->complex);
6420 free (graph->succs);
6422 free (graph->pe_rep);
6423 free (graph->indirect_cycles);
6426 VEC_free (varinfo_t, heap, varmap);
6427 free_alloc_pool (variable_info_pool);
6428 free_alloc_pool (constraint_pool);
6432 /* Compute points-to information for every SSA_NAME pointer in the
6433 current function and compute the transitive closure of escaped
6434 variables to re-initialize the call-clobber states of local variables. */
6437 compute_may_aliases (void)
6439 if (cfun->gimple_df->ipa_pta)
6443 fprintf (dump_file, "\nNot re-computing points-to information "
6444 "because IPA points-to information is available.\n\n");
6446 /* But still dump what we have remaining it. */
6447 dump_alias_info (dump_file);
6449 if (dump_flags & TDF_DETAILS)
6450 dump_referenced_vars (dump_file);
6456 /* For each pointer P_i, determine the sets of variables that P_i may
6457 point-to. Compute the reachability set of escaped and call-used
6459 compute_points_to_sets ();
6461 /* Debugging dumps. */
6464 dump_alias_info (dump_file);
6466 if (dump_flags & TDF_DETAILS)
6467 dump_referenced_vars (dump_file);
6470 /* Deallocate memory used by aliasing data structures and the internal
6471 points-to solution. */
6472 delete_points_to_sets ();
6474 gcc_assert (!need_ssa_update_p (cfun));
6480 gate_tree_pta (void)
6482 return flag_tree_pta;
6485 /* A dummy pass to cause points-to information to be computed via
6486 TODO_rebuild_alias. */
6488 struct gimple_opt_pass pass_build_alias =
6493 gate_tree_pta, /* gate */
6497 0, /* static_pass_number */
6498 TV_NONE, /* tv_id */
6499 PROP_cfg | PROP_ssa, /* properties_required */
6500 0, /* properties_provided */
6501 0, /* properties_destroyed */
6502 0, /* todo_flags_start */
6503 TODO_rebuild_alias | TODO_dump_func /* todo_flags_finish */
6507 /* A dummy pass to cause points-to information to be computed via
6508 TODO_rebuild_alias. */
6510 struct gimple_opt_pass pass_build_ealias =
6514 "ealias", /* name */
6515 gate_tree_pta, /* gate */
6519 0, /* static_pass_number */
6520 TV_NONE, /* tv_id */
6521 PROP_cfg | PROP_ssa, /* properties_required */
6522 0, /* properties_provided */
6523 0, /* properties_destroyed */
6524 0, /* todo_flags_start */
6525 TODO_rebuild_alias | TODO_dump_func /* todo_flags_finish */
6530 /* Return true if we should execute IPA PTA. */
6536 /* Don't bother doing anything if the program has errors. */
6537 && !(errorcount || sorrycount));
6540 /* IPA PTA solutions for ESCAPED. */
6541 struct pt_solution ipa_escaped_pt
6542 = { true, false, false, false, false, false, false, NULL };
6544 /* Execute the driver for IPA PTA. */
6546 ipa_pta_execute (void)
6548 struct cgraph_node *node;
6549 struct varpool_node *var;
6554 init_alias_heapvars ();
6557 /* Build the constraints. */
6558 for (node = cgraph_nodes; node; node = node->next)
6560 /* Nodes without a body are not interesting. Especially do not
6561 visit clones at this point for now - we get duplicate decls
6562 there for inline clones at least. */
6563 if (!gimple_has_body_p (node->decl)
6567 create_function_info_for (node->decl,
6568 cgraph_node_name (node));
6571 /* Create constraints for global variables and their initializers. */
6572 for (var = varpool_nodes; var; var = var->next)
6573 get_vi_for_tree (var->decl);
6578 "Generating constraints for global initializers\n\n");
6579 dump_constraints (dump_file, 0);
6580 fprintf (dump_file, "\n");
6582 from = VEC_length (constraint_t, constraints);
6584 for (node = cgraph_nodes; node; node = node->next)
6586 struct function *func;
6590 /* Nodes without a body are not interesting. */
6591 if (!gimple_has_body_p (node->decl)
6597 "Generating constraints for %s\n",
6598 cgraph_node_name (node));
6600 func = DECL_STRUCT_FUNCTION (node->decl);
6601 old_func_decl = current_function_decl;
6603 current_function_decl = node->decl;
6605 /* For externally visible functions use local constraints for
6606 their arguments. For local functions we see all callers
6607 and thus do not need initial constraints for parameters. */
6608 if (node->local.externally_visible)
6609 intra_create_variable_infos ();
6611 /* Build constriants for the function body. */
6612 FOR_EACH_BB_FN (bb, func)
6614 gimple_stmt_iterator gsi;
6616 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
6619 gimple phi = gsi_stmt (gsi);
6621 if (is_gimple_reg (gimple_phi_result (phi)))
6622 find_func_aliases (phi);
6625 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6627 gimple stmt = gsi_stmt (gsi);
6629 find_func_aliases (stmt);
6630 find_func_clobbers (stmt);
6634 current_function_decl = old_func_decl;
6639 fprintf (dump_file, "\n");
6640 dump_constraints (dump_file, from);
6641 fprintf (dump_file, "\n");
6643 from = VEC_length (constraint_t, constraints);
6646 /* From the constraints compute the points-to sets. */
6647 solve_constraints ();
6649 /* Compute the global points-to sets for ESCAPED.
6650 ??? Note that the computed escape set is not correct
6651 for the whole unit as we fail to consider graph edges to
6652 externally visible functions. */
6653 find_what_var_points_to (get_varinfo (escaped_id), &ipa_escaped_pt);
6655 /* Make sure the ESCAPED solution (which is used as placeholder in
6656 other solutions) does not reference itself. This simplifies
6657 points-to solution queries. */
6658 ipa_escaped_pt.ipa_escaped = 0;
6660 /* Assign the points-to sets to the SSA names in the unit. */
6661 for (node = cgraph_nodes; node; node = node->next)
6664 struct function *fn;
6668 struct pt_solution uses, clobbers;
6669 struct cgraph_edge *e;
6671 /* Nodes without a body are not interesting. */
6672 if (!gimple_has_body_p (node->decl)
6676 fn = DECL_STRUCT_FUNCTION (node->decl);
6678 /* Compute the points-to sets for pointer SSA_NAMEs. */
6679 for (i = 0; VEC_iterate (tree, fn->gimple_df->ssa_names, i, ptr); ++i)
6682 && POINTER_TYPE_P (TREE_TYPE (ptr)))
6683 find_what_p_points_to (ptr);
6686 /* Compute the call-use and call-clobber sets for all direct calls. */
6687 fi = lookup_vi_for_tree (node->decl);
6688 gcc_assert (fi->is_fn_info);
6689 find_what_var_points_to (first_vi_for_offset (fi, fi_clobbers),
6691 find_what_var_points_to (first_vi_for_offset (fi, fi_uses), &uses);
6692 for (e = node->callers; e; e = e->next_caller)
6697 *gimple_call_clobber_set (e->call_stmt) = clobbers;
6698 *gimple_call_use_set (e->call_stmt) = uses;
6701 /* Compute the call-use and call-clobber sets for indirect calls
6702 and calls to external functions. */
6703 FOR_EACH_BB_FN (bb, fn)
6705 gimple_stmt_iterator gsi;
6707 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6709 gimple stmt = gsi_stmt (gsi);
6710 struct pt_solution *pt;
6714 if (!is_gimple_call (stmt))
6717 /* Handle direct calls to external functions. */
6718 decl = gimple_call_fndecl (stmt);
6720 && (!(fi = lookup_vi_for_tree (decl))
6721 || !fi->is_fn_info))
6723 pt = gimple_call_use_set (stmt);
6724 if (gimple_call_flags (stmt) & ECF_CONST)
6725 memset (pt, 0, sizeof (struct pt_solution));
6726 else if ((vi = lookup_call_use_vi (stmt)) != NULL)
6728 find_what_var_points_to (vi, pt);
6729 /* Escaped (and thus nonlocal) variables are always
6730 implicitly used by calls. */
6731 /* ??? ESCAPED can be empty even though NONLOCAL
6734 pt->ipa_escaped = 1;
6738 /* If there is nothing special about this call then
6739 we have made everything that is used also escape. */
6740 *pt = ipa_escaped_pt;
6744 pt = gimple_call_clobber_set (stmt);
6745 if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
6746 memset (pt, 0, sizeof (struct pt_solution));
6747 else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
6749 find_what_var_points_to (vi, pt);
6750 /* Escaped (and thus nonlocal) variables are always
6751 implicitly clobbered by calls. */
6752 /* ??? ESCAPED can be empty even though NONLOCAL
6755 pt->ipa_escaped = 1;
6759 /* If there is nothing special about this call then
6760 we have made everything that is used also escape. */
6761 *pt = ipa_escaped_pt;
6766 /* Handle indirect calls. */
6768 && (fi = get_fi_for_callee (stmt)))
6770 /* We need to accumulate all clobbers/uses of all possible
6772 fi = get_varinfo (find (fi->id));
6773 /* If we cannot constrain the set of functions we'll end up
6774 calling we end up using/clobbering everything. */
6775 if (bitmap_bit_p (fi->solution, anything_id)
6776 || bitmap_bit_p (fi->solution, nonlocal_id)
6777 || bitmap_bit_p (fi->solution, escaped_id))
6779 pt_solution_reset (gimple_call_clobber_set (stmt));
6780 pt_solution_reset (gimple_call_use_set (stmt));
6786 struct pt_solution *uses, *clobbers;
6788 uses = gimple_call_use_set (stmt);
6789 clobbers = gimple_call_clobber_set (stmt);
6790 memset (uses, 0, sizeof (struct pt_solution));
6791 memset (clobbers, 0, sizeof (struct pt_solution));
6792 EXECUTE_IF_SET_IN_BITMAP (fi->solution, 0, i, bi)
6794 struct pt_solution sol;
6796 vi = get_varinfo (i);
6797 if (!vi->is_fn_info)
6799 /* ??? We could be more precise here? */
6801 uses->ipa_escaped = 1;
6802 clobbers->nonlocal = 1;
6803 clobbers->ipa_escaped = 1;
6807 if (!uses->anything)
6809 find_what_var_points_to
6810 (first_vi_for_offset (vi, fi_uses), &sol);
6811 pt_solution_ior_into (uses, &sol);
6813 if (!clobbers->anything)
6815 find_what_var_points_to
6816 (first_vi_for_offset (vi, fi_clobbers), &sol);
6817 pt_solution_ior_into (clobbers, &sol);
6825 fn->gimple_df->ipa_pta = true;
6828 delete_points_to_sets ();
6835 struct simple_ipa_opt_pass pass_ipa_pta =
6840 gate_ipa_pta, /* gate */
6841 ipa_pta_execute, /* execute */
6844 0, /* static_pass_number */
6845 TV_IPA_PTA, /* tv_id */
6846 0, /* properties_required */
6847 0, /* properties_provided */
6848 0, /* properties_destroyed */
6849 0, /* todo_flags_start */
6850 TODO_update_ssa /* todo_flags_finish */
6855 #include "gt-tree-ssa-structalias.h"