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)
2764 int num_printed = 0;
2766 if (DECL_ASSEMBLER_NAME_SET_P (decl))
2767 res = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2769 res= get_name (decl);
2777 if (TREE_CODE (decl) == SSA_NAME)
2779 num_printed = asprintf (&temp, "%s_%u",
2780 alias_get_name (SSA_NAME_VAR (decl)),
2781 SSA_NAME_VERSION (decl));
2783 else if (DECL_P (decl))
2785 num_printed = asprintf (&temp, "D.%u", DECL_UID (decl));
2787 if (num_printed > 0)
2789 res = ggc_strdup (temp);
2795 /* Find the variable id for tree T in the map.
2796 If T doesn't exist in the map, create an entry for it and return it. */
2799 get_vi_for_tree (tree t)
2801 void **slot = pointer_map_contains (vi_for_tree, t);
2803 return get_varinfo (create_variable_info_for (t, alias_get_name (t)));
2805 return (varinfo_t) *slot;
2808 /* Get a scalar constraint expression for a new temporary variable. */
2810 static struct constraint_expr
2811 new_scalar_tmp_constraint_exp (const char *name)
2813 struct constraint_expr tmp;
2816 vi = new_var_info (NULL_TREE, name);
2820 vi->is_full_var = 1;
2829 /* Get a constraint expression vector from an SSA_VAR_P node.
2830 If address_p is true, the result will be taken its address of. */
2833 get_constraint_for_ssa_var (tree t, VEC(ce_s, heap) **results, bool address_p)
2835 struct constraint_expr cexpr;
2838 /* We allow FUNCTION_DECLs here even though it doesn't make much sense. */
2839 gcc_assert (SSA_VAR_P (t) || DECL_P (t));
2841 /* For parameters, get at the points-to set for the actual parm
2843 if (TREE_CODE (t) == SSA_NAME
2844 && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL
2845 && SSA_NAME_IS_DEFAULT_DEF (t))
2847 get_constraint_for_ssa_var (SSA_NAME_VAR (t), results, address_p);
2851 vi = get_vi_for_tree (t);
2853 cexpr.type = SCALAR;
2855 /* If we determine the result is "anything", and we know this is readonly,
2856 say it points to readonly memory instead. */
2857 if (cexpr.var == anything_id && TREE_READONLY (t))
2860 cexpr.type = ADDRESSOF;
2861 cexpr.var = readonly_id;
2864 /* If we are not taking the address of the constraint expr, add all
2865 sub-fiels of the variable as well. */
2867 && !vi->is_full_var)
2869 for (; vi; vi = vi->next)
2872 VEC_safe_push (ce_s, heap, *results, &cexpr);
2877 VEC_safe_push (ce_s, heap, *results, &cexpr);
2880 /* Process constraint T, performing various simplifications and then
2881 adding it to our list of overall constraints. */
2884 process_constraint (constraint_t t)
2886 struct constraint_expr rhs = t->rhs;
2887 struct constraint_expr lhs = t->lhs;
2889 gcc_assert (rhs.var < VEC_length (varinfo_t, varmap));
2890 gcc_assert (lhs.var < VEC_length (varinfo_t, varmap));
2892 /* If we didn't get any useful constraint from the lhs we get
2893 &ANYTHING as fallback from get_constraint_for. Deal with
2894 it here by turning it into *ANYTHING. */
2895 if (lhs.type == ADDRESSOF
2896 && lhs.var == anything_id)
2899 /* ADDRESSOF on the lhs is invalid. */
2900 gcc_assert (lhs.type != ADDRESSOF);
2902 /* We shouldn't add constraints from things that cannot have pointers.
2903 It's not completely trivial to avoid in the callers, so do it here. */
2904 if (rhs.type != ADDRESSOF
2905 && !get_varinfo (rhs.var)->may_have_pointers)
2908 /* Likewise adding to the solution of a non-pointer var isn't useful. */
2909 if (!get_varinfo (lhs.var)->may_have_pointers)
2912 /* This can happen in our IR with things like n->a = *p */
2913 if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
2915 /* Split into tmp = *rhs, *lhs = tmp */
2916 struct constraint_expr tmplhs;
2917 tmplhs = new_scalar_tmp_constraint_exp ("doubledereftmp");
2918 process_constraint (new_constraint (tmplhs, rhs));
2919 process_constraint (new_constraint (lhs, tmplhs));
2921 else if (rhs.type == ADDRESSOF && lhs.type == DEREF)
2923 /* Split into tmp = &rhs, *lhs = tmp */
2924 struct constraint_expr tmplhs;
2925 tmplhs = new_scalar_tmp_constraint_exp ("derefaddrtmp");
2926 process_constraint (new_constraint (tmplhs, rhs));
2927 process_constraint (new_constraint (lhs, tmplhs));
2931 gcc_assert (rhs.type != ADDRESSOF || rhs.offset == 0);
2932 VEC_safe_push (constraint_t, heap, constraints, t);
2936 /* Return true if T is a type that could contain pointers. */
2939 type_could_have_pointers (tree type)
2941 if (POINTER_TYPE_P (type))
2944 if (TREE_CODE (type) == ARRAY_TYPE)
2945 return type_could_have_pointers (TREE_TYPE (type));
2947 /* A function or method can consume pointers.
2948 ??? We could be more precise here. */
2949 if (TREE_CODE (type) == FUNCTION_TYPE
2950 || TREE_CODE (type) == METHOD_TYPE)
2953 return AGGREGATE_TYPE_P (type);
2956 /* Return true if T is a variable of a type that could contain
2960 could_have_pointers (tree t)
2962 return type_could_have_pointers (TREE_TYPE (t));
2965 /* Return the position, in bits, of FIELD_DECL from the beginning of its
2968 static HOST_WIDE_INT
2969 bitpos_of_field (const tree fdecl)
2972 if (!host_integerp (DECL_FIELD_OFFSET (fdecl), 0)
2973 || !host_integerp (DECL_FIELD_BIT_OFFSET (fdecl), 0))
2976 return (TREE_INT_CST_LOW (DECL_FIELD_OFFSET (fdecl)) * 8
2977 + TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fdecl)));
2981 /* Get constraint expressions for offsetting PTR by OFFSET. Stores the
2982 resulting constraint expressions in *RESULTS. */
2985 get_constraint_for_ptr_offset (tree ptr, tree offset,
2986 VEC (ce_s, heap) **results)
2988 struct constraint_expr c;
2990 HOST_WIDE_INT rhsunitoffset, rhsoffset;
2992 /* If we do not do field-sensitive PTA adding offsets to pointers
2993 does not change the points-to solution. */
2994 if (!use_field_sensitive)
2996 get_constraint_for (ptr, results);
3000 /* If the offset is not a non-negative integer constant that fits
3001 in a HOST_WIDE_INT, we have to fall back to a conservative
3002 solution which includes all sub-fields of all pointed-to
3003 variables of ptr. */
3004 if (offset == NULL_TREE
3005 || !host_integerp (offset, 0))
3006 rhsoffset = UNKNOWN_OFFSET;
3009 /* Make sure the bit-offset also fits. */
3010 rhsunitoffset = TREE_INT_CST_LOW (offset);
3011 rhsoffset = rhsunitoffset * BITS_PER_UNIT;
3012 if (rhsunitoffset != rhsoffset / BITS_PER_UNIT)
3013 rhsoffset = UNKNOWN_OFFSET;
3016 get_constraint_for (ptr, results);
3020 /* As we are eventually appending to the solution do not use
3021 VEC_iterate here. */
3022 n = VEC_length (ce_s, *results);
3023 for (j = 0; j < n; j++)
3026 c = *VEC_index (ce_s, *results, j);
3027 curr = get_varinfo (c.var);
3029 if (c.type == ADDRESSOF
3030 /* If this varinfo represents a full variable just use it. */
3031 && curr->is_full_var)
3033 else if (c.type == ADDRESSOF
3034 /* If we do not know the offset add all subfields. */
3035 && rhsoffset == UNKNOWN_OFFSET)
3037 varinfo_t temp = lookup_vi_for_tree (curr->decl);
3040 struct constraint_expr c2;
3042 c2.type = ADDRESSOF;
3044 if (c2.var != c.var)
3045 VEC_safe_push (ce_s, heap, *results, &c2);
3050 else if (c.type == ADDRESSOF)
3053 unsigned HOST_WIDE_INT offset = curr->offset + rhsoffset;
3055 /* Search the sub-field which overlaps with the
3056 pointed-to offset. If the result is outside of the variable
3057 we have to provide a conservative result, as the variable is
3058 still reachable from the resulting pointer (even though it
3059 technically cannot point to anything). The last and first
3060 sub-fields are such conservative results.
3061 ??? If we always had a sub-field for &object + 1 then
3062 we could represent this in a more precise way. */
3064 && curr->offset < offset)
3066 temp = first_or_preceding_vi_for_offset (curr, offset);
3068 /* If the found variable is not exactly at the pointed to
3069 result, we have to include the next variable in the
3070 solution as well. Otherwise two increments by offset / 2
3071 do not result in the same or a conservative superset
3073 if (temp->offset != offset
3074 && temp->next != NULL)
3076 struct constraint_expr c2;
3077 c2.var = temp->next->id;
3078 c2.type = ADDRESSOF;
3080 VEC_safe_push (ce_s, heap, *results, &c2);
3086 c.offset = rhsoffset;
3088 VEC_replace (ce_s, *results, j, &c);
3093 /* Given a COMPONENT_REF T, return the constraint_expr vector for it.
3094 If address_p is true the result will be taken its address of. */
3097 get_constraint_for_component_ref (tree t, VEC(ce_s, heap) **results,
3101 HOST_WIDE_INT bitsize = -1;
3102 HOST_WIDE_INT bitmaxsize = -1;
3103 HOST_WIDE_INT bitpos;
3105 struct constraint_expr *result;
3107 /* Some people like to do cute things like take the address of
3110 while (handled_component_p (forzero)
3111 || INDIRECT_REF_P (forzero))
3112 forzero = TREE_OPERAND (forzero, 0);
3114 if (CONSTANT_CLASS_P (forzero) && integer_zerop (forzero))
3116 struct constraint_expr temp;
3119 temp.var = integer_id;
3121 VEC_safe_push (ce_s, heap, *results, &temp);
3125 t = get_ref_base_and_extent (t, &bitpos, &bitsize, &bitmaxsize);
3127 /* Pretend to take the address of the base, we'll take care of
3128 adding the required subset of sub-fields below. */
3129 get_constraint_for_1 (t, results, true);
3130 gcc_assert (VEC_length (ce_s, *results) == 1);
3131 result = VEC_last (ce_s, *results);
3133 if (result->type == SCALAR
3134 && get_varinfo (result->var)->is_full_var)
3135 /* For single-field vars do not bother about the offset. */
3137 else if (result->type == SCALAR)
3139 /* In languages like C, you can access one past the end of an
3140 array. You aren't allowed to dereference it, so we can
3141 ignore this constraint. When we handle pointer subtraction,
3142 we may have to do something cute here. */
3144 if ((unsigned HOST_WIDE_INT)bitpos < get_varinfo (result->var)->fullsize
3147 /* It's also not true that the constraint will actually start at the
3148 right offset, it may start in some padding. We only care about
3149 setting the constraint to the first actual field it touches, so
3151 struct constraint_expr cexpr = *result;
3153 VEC_pop (ce_s, *results);
3155 for (curr = get_varinfo (cexpr.var); curr; curr = curr->next)
3157 if (ranges_overlap_p (curr->offset, curr->size,
3158 bitpos, bitmaxsize))
3160 cexpr.var = curr->id;
3161 VEC_safe_push (ce_s, heap, *results, &cexpr);
3166 /* If we are going to take the address of this field then
3167 to be able to compute reachability correctly add at least
3168 the last field of the variable. */
3170 && VEC_length (ce_s, *results) == 0)
3172 curr = get_varinfo (cexpr.var);
3173 while (curr->next != NULL)
3175 cexpr.var = curr->id;
3176 VEC_safe_push (ce_s, heap, *results, &cexpr);
3179 /* Assert that we found *some* field there. The user couldn't be
3180 accessing *only* padding. */
3181 /* Still the user could access one past the end of an array
3182 embedded in a struct resulting in accessing *only* padding. */
3183 gcc_assert (VEC_length (ce_s, *results) >= 1
3184 || ref_contains_array_ref (orig_t));
3186 else if (bitmaxsize == 0)
3188 if (dump_file && (dump_flags & TDF_DETAILS))
3189 fprintf (dump_file, "Access to zero-sized part of variable,"
3193 if (dump_file && (dump_flags & TDF_DETAILS))
3194 fprintf (dump_file, "Access to past the end of variable, ignoring\n");
3196 else if (result->type == DEREF)
3198 /* If we do not know exactly where the access goes say so. Note
3199 that only for non-structure accesses we know that we access
3200 at most one subfiled of any variable. */
3202 || bitsize != bitmaxsize
3203 || AGGREGATE_TYPE_P (TREE_TYPE (orig_t)))
3204 result->offset = UNKNOWN_OFFSET;
3206 result->offset = bitpos;
3208 else if (result->type == ADDRESSOF)
3210 /* We can end up here for component references on a
3211 VIEW_CONVERT_EXPR <>(&foobar). */
3212 result->type = SCALAR;
3213 result->var = anything_id;
3221 /* Dereference the constraint expression CONS, and return the result.
3222 DEREF (ADDRESSOF) = SCALAR
3223 DEREF (SCALAR) = DEREF
3224 DEREF (DEREF) = (temp = DEREF1; result = DEREF(temp))
3225 This is needed so that we can handle dereferencing DEREF constraints. */
3228 do_deref (VEC (ce_s, heap) **constraints)
3230 struct constraint_expr *c;
3233 for (i = 0; VEC_iterate (ce_s, *constraints, i, c); i++)
3235 if (c->type == SCALAR)
3237 else if (c->type == ADDRESSOF)
3239 else if (c->type == DEREF)
3241 struct constraint_expr tmplhs;
3242 tmplhs = new_scalar_tmp_constraint_exp ("dereftmp");
3243 process_constraint (new_constraint (tmplhs, *c));
3244 c->var = tmplhs.var;
3251 static void get_constraint_for_1 (tree, VEC (ce_s, heap) **, bool);
3253 /* Given a tree T, return the constraint expression for taking the
3257 get_constraint_for_address_of (tree t, VEC (ce_s, heap) **results)
3259 struct constraint_expr *c;
3262 get_constraint_for_1 (t, results, true);
3264 for (i = 0; VEC_iterate (ce_s, *results, i, c); i++)
3266 if (c->type == DEREF)
3269 c->type = ADDRESSOF;
3273 /* Given a tree T, return the constraint expression for it. */
3276 get_constraint_for_1 (tree t, VEC (ce_s, heap) **results, bool address_p)
3278 struct constraint_expr temp;
3280 /* x = integer is all glommed to a single variable, which doesn't
3281 point to anything by itself. That is, of course, unless it is an
3282 integer constant being treated as a pointer, in which case, we
3283 will return that this is really the addressof anything. This
3284 happens below, since it will fall into the default case. The only
3285 case we know something about an integer treated like a pointer is
3286 when it is the NULL pointer, and then we just say it points to
3289 Do not do that if -fno-delete-null-pointer-checks though, because
3290 in that case *NULL does not fail, so it _should_ alias *anything.
3291 It is not worth adding a new option or renaming the existing one,
3292 since this case is relatively obscure. */
3293 if ((TREE_CODE (t) == INTEGER_CST
3294 && integer_zerop (t))
3295 /* The only valid CONSTRUCTORs in gimple with pointer typed
3296 elements are zero-initializer. But in IPA mode we also
3297 process global initializers, so verify at least. */
3298 || (TREE_CODE (t) == CONSTRUCTOR
3299 && CONSTRUCTOR_NELTS (t) == 0))
3301 if (flag_delete_null_pointer_checks)
3302 temp.var = nothing_id;
3304 temp.var = anything_id;
3305 temp.type = ADDRESSOF;
3307 VEC_safe_push (ce_s, heap, *results, &temp);
3311 /* String constants are read-only. */
3312 if (TREE_CODE (t) == STRING_CST)
3314 temp.var = readonly_id;
3317 VEC_safe_push (ce_s, heap, *results, &temp);
3321 switch (TREE_CODE_CLASS (TREE_CODE (t)))
3323 case tcc_expression:
3325 switch (TREE_CODE (t))
3328 get_constraint_for_address_of (TREE_OPERAND (t, 0), results);
3336 switch (TREE_CODE (t))
3340 get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p);
3345 case ARRAY_RANGE_REF:
3347 get_constraint_for_component_ref (t, results, address_p);
3349 case VIEW_CONVERT_EXPR:
3350 get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p);
3352 /* We are missing handling for TARGET_MEM_REF here. */
3357 case tcc_exceptional:
3359 switch (TREE_CODE (t))
3363 get_constraint_for_ssa_var (t, results, address_p);
3370 VEC (ce_s, heap) *tmp = NULL;
3371 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), i, val)
3373 struct constraint_expr *rhsp;
3375 get_constraint_for_1 (val, &tmp, address_p);
3376 for (j = 0; VEC_iterate (ce_s, tmp, j, rhsp); ++j)
3377 VEC_safe_push (ce_s, heap, *results, rhsp);
3378 VEC_truncate (ce_s, tmp, 0);
3380 VEC_free (ce_s, heap, tmp);
3381 /* We do not know whether the constructor was complete,
3382 so technically we have to add &NOTHING or &ANYTHING
3383 like we do for an empty constructor as well. */
3390 case tcc_declaration:
3392 get_constraint_for_ssa_var (t, results, address_p);
3398 /* The default fallback is a constraint from anything. */
3399 temp.type = ADDRESSOF;
3400 temp.var = anything_id;
3402 VEC_safe_push (ce_s, heap, *results, &temp);
3405 /* Given a gimple tree T, return the constraint expression vector for it. */
3408 get_constraint_for (tree t, VEC (ce_s, heap) **results)
3410 gcc_assert (VEC_length (ce_s, *results) == 0);
3412 get_constraint_for_1 (t, results, false);
3416 /* Efficiently generates constraints from all entries in *RHSC to all
3417 entries in *LHSC. */
3420 process_all_all_constraints (VEC (ce_s, heap) *lhsc, VEC (ce_s, heap) *rhsc)
3422 struct constraint_expr *lhsp, *rhsp;
3425 if (VEC_length (ce_s, lhsc) <= 1
3426 || VEC_length (ce_s, rhsc) <= 1)
3428 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
3429 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); ++j)
3430 process_constraint (new_constraint (*lhsp, *rhsp));
3434 struct constraint_expr tmp;
3435 tmp = new_scalar_tmp_constraint_exp ("allalltmp");
3436 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
3437 process_constraint (new_constraint (tmp, *rhsp));
3438 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
3439 process_constraint (new_constraint (*lhsp, tmp));
3443 /* Handle aggregate copies by expanding into copies of the respective
3444 fields of the structures. */
3447 do_structure_copy (tree lhsop, tree rhsop)
3449 struct constraint_expr *lhsp, *rhsp;
3450 VEC (ce_s, heap) *lhsc = NULL, *rhsc = NULL;
3453 get_constraint_for (lhsop, &lhsc);
3454 get_constraint_for (rhsop, &rhsc);
3455 lhsp = VEC_index (ce_s, lhsc, 0);
3456 rhsp = VEC_index (ce_s, rhsc, 0);
3457 if (lhsp->type == DEREF
3458 || (lhsp->type == ADDRESSOF && lhsp->var == anything_id)
3459 || rhsp->type == DEREF)
3461 if (lhsp->type == DEREF)
3463 gcc_assert (VEC_length (ce_s, lhsc) == 1);
3464 lhsp->offset = UNKNOWN_OFFSET;
3466 if (rhsp->type == DEREF)
3468 gcc_assert (VEC_length (ce_s, rhsc) == 1);
3469 rhsp->offset = UNKNOWN_OFFSET;
3471 process_all_all_constraints (lhsc, rhsc);
3473 else if (lhsp->type == SCALAR
3474 && (rhsp->type == SCALAR
3475 || rhsp->type == ADDRESSOF))
3477 HOST_WIDE_INT lhssize, lhsmaxsize, lhsoffset;
3478 HOST_WIDE_INT rhssize, rhsmaxsize, rhsoffset;
3480 get_ref_base_and_extent (lhsop, &lhsoffset, &lhssize, &lhsmaxsize);
3481 get_ref_base_and_extent (rhsop, &rhsoffset, &rhssize, &rhsmaxsize);
3482 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp);)
3484 varinfo_t lhsv, rhsv;
3485 rhsp = VEC_index (ce_s, rhsc, k);
3486 lhsv = get_varinfo (lhsp->var);
3487 rhsv = get_varinfo (rhsp->var);
3488 if (lhsv->may_have_pointers
3489 && ranges_overlap_p (lhsv->offset + rhsoffset, lhsv->size,
3490 rhsv->offset + lhsoffset, rhsv->size))
3491 process_constraint (new_constraint (*lhsp, *rhsp));
3492 if (lhsv->offset + rhsoffset + lhsv->size
3493 > rhsv->offset + lhsoffset + rhsv->size)
3496 if (k >= VEC_length (ce_s, rhsc))
3506 VEC_free (ce_s, heap, lhsc);
3507 VEC_free (ce_s, heap, rhsc);
3510 /* Create a constraint ID = OP. */
3513 make_constraint_to (unsigned id, tree op)
3515 VEC(ce_s, heap) *rhsc = NULL;
3516 struct constraint_expr *c;
3517 struct constraint_expr includes;
3521 includes.offset = 0;
3522 includes.type = SCALAR;
3524 get_constraint_for (op, &rhsc);
3525 for (j = 0; VEC_iterate (ce_s, rhsc, j, c); j++)
3526 process_constraint (new_constraint (includes, *c));
3527 VEC_free (ce_s, heap, rhsc);
3530 /* Create a constraint ID = &FROM. */
3533 make_constraint_from (varinfo_t vi, int from)
3535 struct constraint_expr lhs, rhs;
3543 rhs.type = ADDRESSOF;
3544 process_constraint (new_constraint (lhs, rhs));
3547 /* Create a constraint ID = FROM. */
3550 make_copy_constraint (varinfo_t vi, int from)
3552 struct constraint_expr lhs, rhs;
3561 process_constraint (new_constraint (lhs, rhs));
3564 /* Make constraints necessary to make OP escape. */
3567 make_escape_constraint (tree op)
3569 make_constraint_to (escaped_id, op);
3572 /* Add constraints to that the solution of VI is transitively closed. */
3575 make_transitive_closure_constraints (varinfo_t vi)
3577 struct constraint_expr lhs, rhs;
3586 process_constraint (new_constraint (lhs, rhs));
3588 /* VAR = VAR + UNKNOWN; */
3594 rhs.offset = UNKNOWN_OFFSET;
3595 process_constraint (new_constraint (lhs, rhs));
3598 /* Create a new artificial heap variable with NAME and make a
3599 constraint from it to LHS. Return the created variable. */
3602 make_constraint_from_heapvar (varinfo_t lhs, const char *name)
3605 tree heapvar = heapvar_lookup (lhs->decl, lhs->offset);
3607 if (heapvar == NULL_TREE)
3610 heapvar = create_tmp_var_raw (ptr_type_node, name);
3611 DECL_EXTERNAL (heapvar) = 1;
3613 heapvar_insert (lhs->decl, lhs->offset, heapvar);
3615 ann = get_var_ann (heapvar);
3616 ann->is_heapvar = 1;
3619 /* For global vars we need to add a heapvar to the list of referenced
3620 vars of a different function than it was created for originally. */
3621 if (cfun && gimple_referenced_vars (cfun))
3622 add_referenced_var (heapvar);
3624 vi = new_var_info (heapvar, name);
3625 vi->is_artificial_var = true;
3626 vi->is_heap_var = true;
3627 vi->is_unknown_size_var = true;
3631 vi->is_full_var = true;
3632 insert_vi_for_tree (heapvar, vi);
3634 make_constraint_from (lhs, vi->id);
3639 /* Create a new artificial heap variable with NAME and make a
3640 constraint from it to LHS. Set flags according to a tag used
3641 for tracking restrict pointers. */
3644 make_constraint_from_restrict (varinfo_t lhs, const char *name)
3647 vi = make_constraint_from_heapvar (lhs, name);
3648 vi->is_restrict_var = 1;
3649 vi->is_global_var = 0;
3650 vi->is_special_var = 1;
3651 vi->may_have_pointers = 0;
3654 /* In IPA mode there are varinfos for different aspects of reach
3655 function designator. One for the points-to set of the return
3656 value, one for the variables that are clobbered by the function,
3657 one for its uses and one for each parameter (including a single
3658 glob for remaining variadic arguments). */
3660 enum { fi_clobbers = 1, fi_uses = 2,
3661 fi_static_chain = 3, fi_result = 4, fi_parm_base = 5 };
3663 /* Get a constraint for the requested part of a function designator FI
3664 when operating in IPA mode. */
3666 static struct constraint_expr
3667 get_function_part_constraint (varinfo_t fi, unsigned part)
3669 struct constraint_expr c;
3671 gcc_assert (in_ipa_mode);
3673 if (fi->id == anything_id)
3675 /* ??? We probably should have a ANYFN special variable. */
3676 c.var = anything_id;
3680 else if (TREE_CODE (fi->decl) == FUNCTION_DECL)
3682 varinfo_t ai = first_vi_for_offset (fi, part);
3686 c.var = anything_id;
3700 /* For non-IPA mode, generate constraints necessary for a call on the
3704 handle_rhs_call (gimple stmt, VEC(ce_s, heap) **results)
3706 struct constraint_expr rhsc;
3709 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3711 tree arg = gimple_call_arg (stmt, i);
3713 /* Find those pointers being passed, and make sure they end up
3714 pointing to anything. */
3715 if (could_have_pointers (arg))
3716 make_escape_constraint (arg);
3719 /* The static chain escapes as well. */
3720 if (gimple_call_chain (stmt))
3721 make_escape_constraint (gimple_call_chain (stmt));
3723 /* And if we applied NRV the address of the return slot escapes as well. */
3724 if (gimple_call_return_slot_opt_p (stmt)
3725 && gimple_call_lhs (stmt) != NULL_TREE
3726 && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt))))
3728 VEC(ce_s, heap) *tmpc = NULL;
3729 struct constraint_expr lhsc, *c;
3730 get_constraint_for_address_of (gimple_call_lhs (stmt), &tmpc);
3731 lhsc.var = escaped_id;
3734 for (i = 0; VEC_iterate (ce_s, tmpc, i, c); ++i)
3735 process_constraint (new_constraint (lhsc, *c));
3736 VEC_free(ce_s, heap, tmpc);
3739 /* Regular functions return nonlocal memory. */
3740 rhsc.var = nonlocal_id;
3743 VEC_safe_push (ce_s, heap, *results, &rhsc);
3746 /* For non-IPA mode, generate constraints necessary for a call
3747 that returns a pointer and assigns it to LHS. This simply makes
3748 the LHS point to global and escaped variables. */
3751 handle_lhs_call (tree lhs, int flags, VEC(ce_s, heap) *rhsc, tree fndecl)
3753 VEC(ce_s, heap) *lhsc = NULL;
3755 get_constraint_for (lhs, &lhsc);
3757 if (flags & ECF_MALLOC)
3760 vi = make_constraint_from_heapvar (get_vi_for_tree (lhs), "HEAP");
3761 /* We delay marking allocated storage global until we know if
3763 DECL_EXTERNAL (vi->decl) = 0;
3764 vi->is_global_var = 0;
3765 /* If this is not a real malloc call assume the memory was
3766 initialized and thus may point to global memory. All
3767 builtin functions with the malloc attribute behave in a sane way. */
3769 || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
3770 make_constraint_from (vi, nonlocal_id);
3772 else if (VEC_length (ce_s, rhsc) > 0)
3774 /* If the store is to a global decl make sure to
3775 add proper escape constraints. */
3776 lhs = get_base_address (lhs);
3779 && is_global_var (lhs))
3781 struct constraint_expr tmpc;
3782 tmpc.var = escaped_id;
3785 VEC_safe_push (ce_s, heap, lhsc, &tmpc);
3787 process_all_all_constraints (lhsc, rhsc);
3789 VEC_free (ce_s, heap, lhsc);
3792 /* For non-IPA mode, generate constraints necessary for a call of a
3793 const function that returns a pointer in the statement STMT. */
3796 handle_const_call (gimple stmt, VEC(ce_s, heap) **results)
3798 struct constraint_expr rhsc;
3801 /* Treat nested const functions the same as pure functions as far
3802 as the static chain is concerned. */
3803 if (gimple_call_chain (stmt))
3805 varinfo_t uses = get_call_use_vi (stmt);
3806 make_transitive_closure_constraints (uses);
3807 make_constraint_to (uses->id, gimple_call_chain (stmt));
3808 rhsc.var = uses->id;
3811 VEC_safe_push (ce_s, heap, *results, &rhsc);
3814 /* May return arguments. */
3815 for (k = 0; k < gimple_call_num_args (stmt); ++k)
3817 tree arg = gimple_call_arg (stmt, k);
3819 if (could_have_pointers (arg))
3821 VEC(ce_s, heap) *argc = NULL;
3823 struct constraint_expr *argp;
3824 get_constraint_for (arg, &argc);
3825 for (i = 0; VEC_iterate (ce_s, argc, i, argp); ++i)
3826 VEC_safe_push (ce_s, heap, *results, argp);
3827 VEC_free(ce_s, heap, argc);
3831 /* May return addresses of globals. */
3832 rhsc.var = nonlocal_id;
3834 rhsc.type = ADDRESSOF;
3835 VEC_safe_push (ce_s, heap, *results, &rhsc);
3838 /* For non-IPA mode, generate constraints necessary for a call to a
3839 pure function in statement STMT. */
3842 handle_pure_call (gimple stmt, VEC(ce_s, heap) **results)
3844 struct constraint_expr rhsc;
3846 varinfo_t uses = NULL;
3848 /* Memory reached from pointer arguments is call-used. */
3849 for (i = 0; i < gimple_call_num_args (stmt); ++i)
3851 tree arg = gimple_call_arg (stmt, i);
3853 if (could_have_pointers (arg))
3857 uses = get_call_use_vi (stmt);
3858 make_transitive_closure_constraints (uses);
3860 make_constraint_to (uses->id, arg);
3864 /* The static chain is used as well. */
3865 if (gimple_call_chain (stmt))
3869 uses = get_call_use_vi (stmt);
3870 make_transitive_closure_constraints (uses);
3872 make_constraint_to (uses->id, gimple_call_chain (stmt));
3875 /* Pure functions may return call-used and nonlocal memory. */
3878 rhsc.var = uses->id;
3881 VEC_safe_push (ce_s, heap, *results, &rhsc);
3883 rhsc.var = nonlocal_id;
3886 VEC_safe_push (ce_s, heap, *results, &rhsc);
3890 /* Return the varinfo for the callee of CALL. */
3893 get_fi_for_callee (gimple call)
3897 /* If we can directly resolve the function being called, do so.
3898 Otherwise, it must be some sort of indirect expression that
3899 we should still be able to handle. */
3900 decl = gimple_call_fndecl (call);
3902 return get_vi_for_tree (decl);
3904 decl = gimple_call_fn (call);
3905 /* The function can be either an SSA name pointer or,
3906 worse, an OBJ_TYPE_REF. In this case we have no
3907 clue and should be getting ANYFN (well, ANYTHING for now). */
3908 if (TREE_CODE (decl) == SSA_NAME)
3910 if (TREE_CODE (decl) == SSA_NAME
3911 && TREE_CODE (SSA_NAME_VAR (decl)) == PARM_DECL
3912 && SSA_NAME_IS_DEFAULT_DEF (decl))
3913 decl = SSA_NAME_VAR (decl);
3914 return get_vi_for_tree (decl);
3916 else if (TREE_CODE (decl) == INTEGER_CST
3917 || TREE_CODE (decl) == OBJ_TYPE_REF)
3918 return get_varinfo (anything_id);
3923 /* Walk statement T setting up aliasing constraints according to the
3924 references found in T. This function is the main part of the
3925 constraint builder. AI points to auxiliary alias information used
3926 when building alias sets and computing alias grouping heuristics. */
3929 find_func_aliases (gimple origt)
3932 VEC(ce_s, heap) *lhsc = NULL;
3933 VEC(ce_s, heap) *rhsc = NULL;
3934 struct constraint_expr *c;
3937 /* Now build constraints expressions. */
3938 if (gimple_code (t) == GIMPLE_PHI)
3940 gcc_assert (!AGGREGATE_TYPE_P (TREE_TYPE (gimple_phi_result (t))));
3942 /* Only care about pointers and structures containing
3944 if (could_have_pointers (gimple_phi_result (t)))
3949 /* For a phi node, assign all the arguments to
3951 get_constraint_for (gimple_phi_result (t), &lhsc);
3952 for (i = 0; i < gimple_phi_num_args (t); i++)
3954 tree strippedrhs = PHI_ARG_DEF (t, i);
3956 STRIP_NOPS (strippedrhs);
3957 get_constraint_for (gimple_phi_arg_def (t, i), &rhsc);
3959 for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
3961 struct constraint_expr *c2;
3962 while (VEC_length (ce_s, rhsc) > 0)
3964 c2 = VEC_last (ce_s, rhsc);
3965 process_constraint (new_constraint (*c, *c2));
3966 VEC_pop (ce_s, rhsc);
3972 /* In IPA mode, we need to generate constraints to pass call
3973 arguments through their calls. There are two cases,
3974 either a GIMPLE_CALL returning a value, or just a plain
3975 GIMPLE_CALL when we are not.
3977 In non-ipa mode, we need to generate constraints for each
3978 pointer passed by address. */
3979 else if (is_gimple_call (t))
3981 tree fndecl = gimple_call_fndecl (t);
3982 if (fndecl != NULL_TREE
3983 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
3984 /* ??? All builtins that are handled here need to be handled
3985 in the alias-oracle query functions explicitly! */
3986 switch (DECL_FUNCTION_CODE (fndecl))
3988 /* All the following functions return a pointer to the same object
3989 as their first argument points to. The functions do not add
3990 to the ESCAPED solution. The functions make the first argument
3991 pointed to memory point to what the second argument pointed to
3992 memory points to. */
3993 case BUILT_IN_STRCPY:
3994 case BUILT_IN_STRNCPY:
3995 case BUILT_IN_BCOPY:
3996 case BUILT_IN_MEMCPY:
3997 case BUILT_IN_MEMMOVE:
3998 case BUILT_IN_MEMPCPY:
3999 case BUILT_IN_STPCPY:
4000 case BUILT_IN_STPNCPY:
4001 case BUILT_IN_STRCAT:
4002 case BUILT_IN_STRNCAT:
4004 tree res = gimple_call_lhs (t);
4005 tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
4006 == BUILT_IN_BCOPY ? 1 : 0));
4007 tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
4008 == BUILT_IN_BCOPY ? 0 : 1));
4009 if (res != NULL_TREE)
4011 get_constraint_for (res, &lhsc);
4012 if (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMPCPY
4013 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPCPY
4014 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPNCPY)
4015 get_constraint_for_ptr_offset (dest, NULL_TREE, &rhsc);
4017 get_constraint_for (dest, &rhsc);
4018 process_all_all_constraints (lhsc, rhsc);
4019 VEC_free (ce_s, heap, lhsc);
4020 VEC_free (ce_s, heap, rhsc);
4022 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4023 get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
4026 process_all_all_constraints (lhsc, rhsc);
4027 VEC_free (ce_s, heap, lhsc);
4028 VEC_free (ce_s, heap, rhsc);
4031 case BUILT_IN_MEMSET:
4033 tree res = gimple_call_lhs (t);
4034 tree dest = gimple_call_arg (t, 0);
4037 struct constraint_expr ac;
4038 if (res != NULL_TREE)
4040 get_constraint_for (res, &lhsc);
4041 get_constraint_for (dest, &rhsc);
4042 process_all_all_constraints (lhsc, rhsc);
4043 VEC_free (ce_s, heap, lhsc);
4044 VEC_free (ce_s, heap, rhsc);
4046 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4048 if (flag_delete_null_pointer_checks
4049 && integer_zerop (gimple_call_arg (t, 1)))
4051 ac.type = ADDRESSOF;
4052 ac.var = nothing_id;
4057 ac.var = integer_id;
4060 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
4061 process_constraint (new_constraint (*lhsp, ac));
4062 VEC_free (ce_s, heap, lhsc);
4065 /* All the following functions do not return pointers, do not
4066 modify the points-to sets of memory reachable from their
4067 arguments and do not add to the ESCAPED solution. */
4068 case BUILT_IN_SINCOS:
4069 case BUILT_IN_SINCOSF:
4070 case BUILT_IN_SINCOSL:
4071 case BUILT_IN_FREXP:
4072 case BUILT_IN_FREXPF:
4073 case BUILT_IN_FREXPL:
4074 case BUILT_IN_GAMMA_R:
4075 case BUILT_IN_GAMMAF_R:
4076 case BUILT_IN_GAMMAL_R:
4077 case BUILT_IN_LGAMMA_R:
4078 case BUILT_IN_LGAMMAF_R:
4079 case BUILT_IN_LGAMMAL_R:
4081 case BUILT_IN_MODFF:
4082 case BUILT_IN_MODFL:
4083 case BUILT_IN_REMQUO:
4084 case BUILT_IN_REMQUOF:
4085 case BUILT_IN_REMQUOL:
4088 /* Trampolines are special - they set up passing the static
4090 case BUILT_IN_INIT_TRAMPOLINE:
4092 tree tramp = gimple_call_arg (t, 0);
4093 tree nfunc = gimple_call_arg (t, 1);
4094 tree frame = gimple_call_arg (t, 2);
4096 struct constraint_expr lhs, *rhsp;
4099 varinfo_t nfi = NULL;
4100 gcc_assert (TREE_CODE (nfunc) == ADDR_EXPR);
4101 nfi = lookup_vi_for_tree (TREE_OPERAND (nfunc, 0));
4104 lhs = get_function_part_constraint (nfi, fi_static_chain);
4105 get_constraint_for (frame, &rhsc);
4106 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
4107 process_constraint (new_constraint (lhs, *rhsp));
4108 VEC_free (ce_s, heap, rhsc);
4110 /* Make the frame point to the function for
4111 the trampoline adjustment call. */
4112 get_constraint_for (tramp, &lhsc);
4114 get_constraint_for (nfunc, &rhsc);
4115 process_all_all_constraints (lhsc, rhsc);
4116 VEC_free (ce_s, heap, rhsc);
4117 VEC_free (ce_s, heap, lhsc);
4122 /* Else fallthru to generic handling which will let
4123 the frame escape. */
4126 case BUILT_IN_ADJUST_TRAMPOLINE:
4128 tree tramp = gimple_call_arg (t, 0);
4129 tree res = gimple_call_lhs (t);
4130 if (in_ipa_mode && res)
4132 get_constraint_for (res, &lhsc);
4133 get_constraint_for (tramp, &rhsc);
4135 process_all_all_constraints (lhsc, rhsc);
4136 VEC_free (ce_s, heap, rhsc);
4137 VEC_free (ce_s, heap, lhsc);
4141 /* Variadic argument handling needs to be handled in IPA
4143 case BUILT_IN_VA_START:
4147 tree valist = gimple_call_arg (t, 0);
4148 struct constraint_expr rhs, *lhsp;
4150 /* The va_list gets access to pointers in variadic
4152 fi = lookup_vi_for_tree (cfun->decl);
4153 gcc_assert (fi != NULL);
4154 get_constraint_for (valist, &lhsc);
4156 rhs = get_function_part_constraint (fi, ~0);
4157 rhs.type = ADDRESSOF;
4158 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
4159 process_constraint (new_constraint (*lhsp, rhs));
4160 VEC_free (ce_s, heap, lhsc);
4161 /* va_list is clobbered. */
4162 make_constraint_to (get_call_clobber_vi (t)->id, valist);
4167 /* va_end doesn't have any effect that matters. */
4168 case BUILT_IN_VA_END:
4170 /* printf-style functions may have hooks to set pointers to
4171 point to somewhere into the generated string. Leave them
4172 for a later excercise... */
4174 /* Fallthru to general call handling. */;
4178 && (!(fi = lookup_vi_for_tree (fndecl))
4179 || !fi->is_fn_info)))
4181 VEC(ce_s, heap) *rhsc = NULL;
4182 int flags = gimple_call_flags (t);
4184 /* Const functions can return their arguments and addresses
4185 of global memory but not of escaped memory. */
4186 if (flags & (ECF_CONST|ECF_NOVOPS))
4188 if (gimple_call_lhs (t)
4189 && could_have_pointers (gimple_call_lhs (t)))
4190 handle_const_call (t, &rhsc);
4192 /* Pure functions can return addresses in and of memory
4193 reachable from their arguments, but they are not an escape
4194 point for reachable memory of their arguments. */
4195 else if (flags & (ECF_PURE|ECF_LOOPING_CONST_OR_PURE))
4196 handle_pure_call (t, &rhsc);
4198 handle_rhs_call (t, &rhsc);
4199 if (gimple_call_lhs (t)
4200 && could_have_pointers (gimple_call_lhs (t)))
4201 handle_lhs_call (gimple_call_lhs (t), flags, rhsc, fndecl);
4202 VEC_free (ce_s, heap, rhsc);
4209 fi = get_fi_for_callee (t);
4211 /* Assign all the passed arguments to the appropriate incoming
4212 parameters of the function. */
4213 for (j = 0; j < gimple_call_num_args (t); j++)
4215 struct constraint_expr lhs ;
4216 struct constraint_expr *rhsp;
4217 tree arg = gimple_call_arg (t, j);
4219 if (!could_have_pointers (arg))
4222 get_constraint_for (arg, &rhsc);
4223 lhs = get_function_part_constraint (fi, fi_parm_base + j);
4224 while (VEC_length (ce_s, rhsc) != 0)
4226 rhsp = VEC_last (ce_s, rhsc);
4227 process_constraint (new_constraint (lhs, *rhsp));
4228 VEC_pop (ce_s, rhsc);
4232 /* If we are returning a value, assign it to the result. */
4233 lhsop = gimple_call_lhs (t);
4235 && could_have_pointers (lhsop))
4237 struct constraint_expr rhs;
4238 struct constraint_expr *lhsp;
4240 get_constraint_for (lhsop, &lhsc);
4241 rhs = get_function_part_constraint (fi, fi_result);
4243 && DECL_RESULT (fndecl)
4244 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
4246 VEC(ce_s, heap) *tem = NULL;
4247 VEC_safe_push (ce_s, heap, tem, &rhs);
4249 rhs = *VEC_index (ce_s, tem, 0);
4250 VEC_free(ce_s, heap, tem);
4252 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
4253 process_constraint (new_constraint (*lhsp, rhs));
4256 /* If we pass the result decl by reference, honor that. */
4259 && DECL_RESULT (fndecl)
4260 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
4262 struct constraint_expr lhs;
4263 struct constraint_expr *rhsp;
4265 get_constraint_for_address_of (lhsop, &rhsc);
4266 lhs = get_function_part_constraint (fi, fi_result);
4267 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4268 process_constraint (new_constraint (lhs, *rhsp));
4269 VEC_free (ce_s, heap, rhsc);
4272 /* If we use a static chain, pass it along. */
4273 if (gimple_call_chain (t))
4275 struct constraint_expr lhs;
4276 struct constraint_expr *rhsp;
4278 get_constraint_for (gimple_call_chain (t), &rhsc);
4279 lhs = get_function_part_constraint (fi, fi_static_chain);
4280 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4281 process_constraint (new_constraint (lhs, *rhsp));
4285 /* Otherwise, just a regular assignment statement. Only care about
4286 operations with pointer result, others are dealt with as escape
4287 points if they have pointer operands. */
4288 else if (is_gimple_assign (t)
4289 && could_have_pointers (gimple_assign_lhs (t)))
4291 /* Otherwise, just a regular assignment statement. */
4292 tree lhsop = gimple_assign_lhs (t);
4293 tree rhsop = (gimple_num_ops (t) == 2) ? gimple_assign_rhs1 (t) : NULL;
4295 if (rhsop && AGGREGATE_TYPE_P (TREE_TYPE (lhsop)))
4296 do_structure_copy (lhsop, rhsop);
4299 struct constraint_expr temp;
4300 get_constraint_for (lhsop, &lhsc);
4302 if (gimple_assign_rhs_code (t) == POINTER_PLUS_EXPR)
4303 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
4304 gimple_assign_rhs2 (t), &rhsc);
4305 else if ((CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (t))
4306 && !(POINTER_TYPE_P (gimple_expr_type (t))
4307 && !POINTER_TYPE_P (TREE_TYPE (rhsop))))
4308 || gimple_assign_single_p (t))
4309 get_constraint_for (rhsop, &rhsc);
4312 temp.type = ADDRESSOF;
4313 temp.var = anything_id;
4315 VEC_safe_push (ce_s, heap, rhsc, &temp);
4317 process_all_all_constraints (lhsc, rhsc);
4319 /* If there is a store to a global variable the rhs escapes. */
4320 if ((lhsop = get_base_address (lhsop)) != NULL_TREE
4322 && is_global_var (lhsop)
4324 || DECL_EXTERNAL (lhsop) || TREE_PUBLIC (lhsop)))
4325 make_escape_constraint (rhsop);
4326 /* If this is a conversion of a non-restrict pointer to a
4327 restrict pointer track it with a new heapvar. */
4328 else if (gimple_assign_cast_p (t)
4329 && POINTER_TYPE_P (TREE_TYPE (rhsop))
4330 && POINTER_TYPE_P (TREE_TYPE (lhsop))
4331 && !TYPE_RESTRICT (TREE_TYPE (rhsop))
4332 && TYPE_RESTRICT (TREE_TYPE (lhsop)))
4333 make_constraint_from_restrict (get_vi_for_tree (lhsop),
4336 /* For conversions of pointers to non-pointers the pointer escapes. */
4337 else if (gimple_assign_cast_p (t)
4338 && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (t)))
4339 && !POINTER_TYPE_P (TREE_TYPE (gimple_assign_lhs (t))))
4341 make_escape_constraint (gimple_assign_rhs1 (t));
4343 /* Handle escapes through return. */
4344 else if (gimple_code (t) == GIMPLE_RETURN
4345 && gimple_return_retval (t) != NULL_TREE
4346 && could_have_pointers (gimple_return_retval (t)))
4350 || !(fi = get_vi_for_tree (cfun->decl)))
4351 make_escape_constraint (gimple_return_retval (t));
4352 else if (in_ipa_mode
4355 struct constraint_expr lhs ;
4356 struct constraint_expr *rhsp;
4359 lhs = get_function_part_constraint (fi, fi_result);
4360 get_constraint_for (gimple_return_retval (t), &rhsc);
4361 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4362 process_constraint (new_constraint (lhs, *rhsp));
4365 /* Handle asms conservatively by adding escape constraints to everything. */
4366 else if (gimple_code (t) == GIMPLE_ASM)
4368 unsigned i, noutputs;
4369 const char **oconstraints;
4370 const char *constraint;
4371 bool allows_mem, allows_reg, is_inout;
4373 noutputs = gimple_asm_noutputs (t);
4374 oconstraints = XALLOCAVEC (const char *, noutputs);
4376 for (i = 0; i < noutputs; ++i)
4378 tree link = gimple_asm_output_op (t, i);
4379 tree op = TREE_VALUE (link);
4381 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
4382 oconstraints[i] = constraint;
4383 parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
4384 &allows_reg, &is_inout);
4386 /* A memory constraint makes the address of the operand escape. */
4387 if (!allows_reg && allows_mem)
4388 make_escape_constraint (build_fold_addr_expr (op));
4390 /* The asm may read global memory, so outputs may point to
4391 any global memory. */
4392 if (op && could_have_pointers (op))
4394 VEC(ce_s, heap) *lhsc = NULL;
4395 struct constraint_expr rhsc, *lhsp;
4397 get_constraint_for (op, &lhsc);
4398 rhsc.var = nonlocal_id;
4401 for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
4402 process_constraint (new_constraint (*lhsp, rhsc));
4403 VEC_free (ce_s, heap, lhsc);
4406 for (i = 0; i < gimple_asm_ninputs (t); ++i)
4408 tree link = gimple_asm_input_op (t, i);
4409 tree op = TREE_VALUE (link);
4411 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
4413 parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints,
4414 &allows_mem, &allows_reg);
4416 /* A memory constraint makes the address of the operand escape. */
4417 if (!allows_reg && allows_mem)
4418 make_escape_constraint (build_fold_addr_expr (op));
4419 /* Strictly we'd only need the constraint to ESCAPED if
4420 the asm clobbers memory, otherwise using something
4421 along the lines of per-call clobbers/uses would be enough. */
4422 else if (op && could_have_pointers (op))
4423 make_escape_constraint (op);
4427 VEC_free (ce_s, heap, rhsc);
4428 VEC_free (ce_s, heap, lhsc);
4432 /* Create a constraint adding to the clobber set of FI the memory
4433 pointed to by PTR. */
4436 process_ipa_clobber (varinfo_t fi, tree ptr)
4438 VEC(ce_s, heap) *ptrc = NULL;
4439 struct constraint_expr *c, lhs;
4441 get_constraint_for (ptr, &ptrc);
4442 lhs = get_function_part_constraint (fi, fi_clobbers);
4443 for (i = 0; VEC_iterate (ce_s, ptrc, i, c); i++)
4444 process_constraint (new_constraint (lhs, *c));
4445 VEC_free (ce_s, heap, ptrc);
4448 /* Walk statement T setting up clobber and use constraints according to the
4449 references found in T. This function is a main part of the
4450 IPA constraint builder. */
4453 find_func_clobbers (gimple origt)
4456 VEC(ce_s, heap) *lhsc = NULL;
4457 VEC(ce_s, heap) *rhsc = NULL;
4460 /* Add constraints for clobbered/used in IPA mode.
4461 We are not interested in what automatic variables are clobbered
4462 or used as we only use the information in the caller to which
4463 they do not escape. */
4464 gcc_assert (in_ipa_mode);
4466 /* If the stmt refers to memory in any way it better had a VUSE. */
4467 if (gimple_vuse (t) == NULL_TREE)
4470 /* We'd better have function information for the current function. */
4471 fi = lookup_vi_for_tree (cfun->decl);
4472 gcc_assert (fi != NULL);
4474 /* Account for stores in assignments and calls. */
4475 if (gimple_vdef (t) != NULL_TREE
4476 && gimple_has_lhs (t))
4478 tree lhs = gimple_get_lhs (t);
4480 while (handled_component_p (tem))
4481 tem = TREE_OPERAND (tem, 0);
4483 && !auto_var_in_fn_p (tem, cfun->decl))
4484 || INDIRECT_REF_P (tem))
4486 struct constraint_expr lhsc, *rhsp;
4488 lhsc = get_function_part_constraint (fi, fi_clobbers);
4489 get_constraint_for_address_of (lhs, &rhsc);
4490 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4491 process_constraint (new_constraint (lhsc, *rhsp));
4492 VEC_free (ce_s, heap, rhsc);
4496 /* Account for uses in assigments and returns. */
4497 if (gimple_assign_single_p (t)
4498 || (gimple_code (t) == GIMPLE_RETURN
4499 && gimple_return_retval (t) != NULL_TREE))
4501 tree rhs = (gimple_assign_single_p (t)
4502 ? gimple_assign_rhs1 (t) : gimple_return_retval (t));
4504 while (handled_component_p (tem))
4505 tem = TREE_OPERAND (tem, 0);
4507 && !auto_var_in_fn_p (tem, cfun->decl))
4508 || INDIRECT_REF_P (tem))
4510 struct constraint_expr lhs, *rhsp;
4512 lhs = get_function_part_constraint (fi, fi_uses);
4513 get_constraint_for_address_of (rhs, &rhsc);
4514 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4515 process_constraint (new_constraint (lhs, *rhsp));
4516 VEC_free (ce_s, heap, rhsc);
4520 if (is_gimple_call (t))
4522 varinfo_t cfi = NULL;
4523 tree decl = gimple_call_fndecl (t);
4524 struct constraint_expr lhs, rhs;
4527 /* For builtins we do not have separate function info. For those
4528 we do not generate escapes for we have to generate clobbers/uses. */
4530 && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
4531 switch (DECL_FUNCTION_CODE (decl))
4533 /* The following functions use and clobber memory pointed to
4534 by their arguments. */
4535 case BUILT_IN_STRCPY:
4536 case BUILT_IN_STRNCPY:
4537 case BUILT_IN_BCOPY:
4538 case BUILT_IN_MEMCPY:
4539 case BUILT_IN_MEMMOVE:
4540 case BUILT_IN_MEMPCPY:
4541 case BUILT_IN_STPCPY:
4542 case BUILT_IN_STPNCPY:
4543 case BUILT_IN_STRCAT:
4544 case BUILT_IN_STRNCAT:
4546 tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
4547 == BUILT_IN_BCOPY ? 1 : 0));
4548 tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
4549 == BUILT_IN_BCOPY ? 0 : 1));
4551 struct constraint_expr *rhsp, *lhsp;
4552 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4553 lhs = get_function_part_constraint (fi, fi_clobbers);
4554 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); i++)
4555 process_constraint (new_constraint (lhs, *lhsp));
4556 VEC_free (ce_s, heap, lhsc);
4557 get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
4558 lhs = get_function_part_constraint (fi, fi_uses);
4559 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
4560 process_constraint (new_constraint (lhs, *rhsp));
4561 VEC_free (ce_s, heap, rhsc);
4564 /* The following function clobbers memory pointed to by
4566 case BUILT_IN_MEMSET:
4568 tree dest = gimple_call_arg (t, 0);
4571 get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
4572 lhs = get_function_part_constraint (fi, fi_clobbers);
4573 for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); i++)
4574 process_constraint (new_constraint (lhs, *lhsp));
4575 VEC_free (ce_s, heap, lhsc);
4578 /* The following functions clobber their second and third
4580 case BUILT_IN_SINCOS:
4581 case BUILT_IN_SINCOSF:
4582 case BUILT_IN_SINCOSL:
4584 process_ipa_clobber (fi, gimple_call_arg (t, 1));
4585 process_ipa_clobber (fi, gimple_call_arg (t, 2));
4588 /* The following functions clobber their second argument. */
4589 case BUILT_IN_FREXP:
4590 case BUILT_IN_FREXPF:
4591 case BUILT_IN_FREXPL:
4592 case BUILT_IN_LGAMMA_R:
4593 case BUILT_IN_LGAMMAF_R:
4594 case BUILT_IN_LGAMMAL_R:
4595 case BUILT_IN_GAMMA_R:
4596 case BUILT_IN_GAMMAF_R:
4597 case BUILT_IN_GAMMAL_R:
4599 case BUILT_IN_MODFF:
4600 case BUILT_IN_MODFL:
4602 process_ipa_clobber (fi, gimple_call_arg (t, 1));
4605 /* The following functions clobber their third argument. */
4606 case BUILT_IN_REMQUO:
4607 case BUILT_IN_REMQUOF:
4608 case BUILT_IN_REMQUOL:
4610 process_ipa_clobber (fi, gimple_call_arg (t, 2));
4613 /* The following functions neither read nor clobber memory. */
4616 /* Trampolines are of no interest to us. */
4617 case BUILT_IN_INIT_TRAMPOLINE:
4618 case BUILT_IN_ADJUST_TRAMPOLINE:
4620 case BUILT_IN_VA_START:
4621 case BUILT_IN_VA_END:
4623 /* printf-style functions may have hooks to set pointers to
4624 point to somewhere into the generated string. Leave them
4625 for a later excercise... */
4627 /* Fallthru to general call handling. */;
4630 /* Parameters passed by value are used. */
4631 lhs = get_function_part_constraint (fi, fi_uses);
4632 for (i = 0; i < gimple_call_num_args (t); i++)
4634 struct constraint_expr *rhsp;
4635 tree arg = gimple_call_arg (t, i);
4637 if (TREE_CODE (arg) == SSA_NAME
4638 || is_gimple_min_invariant (arg))
4641 get_constraint_for_address_of (arg, &rhsc);
4642 for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
4643 process_constraint (new_constraint (lhs, *rhsp));
4644 VEC_free (ce_s, heap, rhsc);
4647 /* Build constraints for propagating clobbers/uses along the
4649 cfi = get_fi_for_callee (t);
4650 if (cfi->id == anything_id)
4652 if (gimple_vdef (t))
4653 make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
4655 make_constraint_from (first_vi_for_offset (fi, fi_uses),
4660 /* For callees without function info (that's external functions),
4661 ESCAPED is clobbered and used. */
4662 if (gimple_call_fndecl (t)
4663 && !cfi->is_fn_info)
4667 if (gimple_vdef (t))
4668 make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
4670 make_copy_constraint (first_vi_for_offset (fi, fi_uses), escaped_id);
4672 /* Also honor the call statement use/clobber info. */
4673 if ((vi = lookup_call_clobber_vi (t)) != NULL)
4674 make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
4676 if ((vi = lookup_call_use_vi (t)) != NULL)
4677 make_copy_constraint (first_vi_for_offset (fi, fi_uses),
4682 /* Otherwise the caller clobbers and uses what the callee does.
4683 ??? This should use a new complex constraint that filters
4684 local variables of the callee. */
4685 if (gimple_vdef (t))
4687 lhs = get_function_part_constraint (fi, fi_clobbers);
4688 rhs = get_function_part_constraint (cfi, fi_clobbers);
4689 process_constraint (new_constraint (lhs, rhs));
4691 lhs = get_function_part_constraint (fi, fi_uses);
4692 rhs = get_function_part_constraint (cfi, fi_uses);
4693 process_constraint (new_constraint (lhs, rhs));
4695 else if (gimple_code (t) == GIMPLE_ASM)
4697 /* ??? Ick. We can do better. */
4698 if (gimple_vdef (t))
4699 make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
4701 make_constraint_from (first_vi_for_offset (fi, fi_uses),
4705 VEC_free (ce_s, heap, rhsc);
4709 /* Find the first varinfo in the same variable as START that overlaps with
4710 OFFSET. Return NULL if we can't find one. */
4713 first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
4715 /* If the offset is outside of the variable, bail out. */
4716 if (offset >= start->fullsize)
4719 /* If we cannot reach offset from start, lookup the first field
4720 and start from there. */
4721 if (start->offset > offset)
4722 start = lookup_vi_for_tree (start->decl);
4726 /* We may not find a variable in the field list with the actual
4727 offset when when we have glommed a structure to a variable.
4728 In that case, however, offset should still be within the size
4730 if (offset >= start->offset
4731 && (offset - start->offset) < start->size)
4740 /* Find the first varinfo in the same variable as START that overlaps with
4741 OFFSET. If there is no such varinfo the varinfo directly preceding
4742 OFFSET is returned. */
4745 first_or_preceding_vi_for_offset (varinfo_t start,
4746 unsigned HOST_WIDE_INT offset)
4748 /* If we cannot reach offset from start, lookup the first field
4749 and start from there. */
4750 if (start->offset > offset)
4751 start = lookup_vi_for_tree (start->decl);
4753 /* We may not find a variable in the field list with the actual
4754 offset when when we have glommed a structure to a variable.
4755 In that case, however, offset should still be within the size
4757 If we got beyond the offset we look for return the field
4758 directly preceding offset which may be the last field. */
4760 && offset >= start->offset
4761 && !((offset - start->offset) < start->size))
4762 start = start->next;
4768 /* This structure is used during pushing fields onto the fieldstack
4769 to track the offset of the field, since bitpos_of_field gives it
4770 relative to its immediate containing type, and we want it relative
4771 to the ultimate containing object. */
4775 /* Offset from the base of the base containing object to this field. */
4776 HOST_WIDE_INT offset;
4778 /* Size, in bits, of the field. */
4779 unsigned HOST_WIDE_INT size;
4781 unsigned has_unknown_size : 1;
4783 unsigned may_have_pointers : 1;
4785 unsigned only_restrict_pointers : 1;
4787 typedef struct fieldoff fieldoff_s;
4789 DEF_VEC_O(fieldoff_s);
4790 DEF_VEC_ALLOC_O(fieldoff_s,heap);
4792 /* qsort comparison function for two fieldoff's PA and PB */
4795 fieldoff_compare (const void *pa, const void *pb)
4797 const fieldoff_s *foa = (const fieldoff_s *)pa;
4798 const fieldoff_s *fob = (const fieldoff_s *)pb;
4799 unsigned HOST_WIDE_INT foasize, fobsize;
4801 if (foa->offset < fob->offset)
4803 else if (foa->offset > fob->offset)
4806 foasize = foa->size;
4807 fobsize = fob->size;
4808 if (foasize < fobsize)
4810 else if (foasize > fobsize)
4815 /* Sort a fieldstack according to the field offset and sizes. */
4817 sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
4819 qsort (VEC_address (fieldoff_s, fieldstack),
4820 VEC_length (fieldoff_s, fieldstack),
4821 sizeof (fieldoff_s),
4825 /* Return true if V is a tree that we can have subvars for.
4826 Normally, this is any aggregate type. Also complex
4827 types which are not gimple registers can have subvars. */
4830 var_can_have_subvars (const_tree v)
4832 /* Volatile variables should never have subvars. */
4833 if (TREE_THIS_VOLATILE (v))
4836 /* Non decls or memory tags can never have subvars. */
4840 /* Aggregates without overlapping fields can have subvars. */
4841 if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE)
4847 /* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
4848 the fields of TYPE onto fieldstack, recording their offsets along
4851 OFFSET is used to keep track of the offset in this entire
4852 structure, rather than just the immediately containing structure.
4853 Returns false if the caller is supposed to handle the field we
4857 push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
4858 HOST_WIDE_INT offset)
4861 bool empty_p = true;
4863 if (TREE_CODE (type) != RECORD_TYPE)
4866 /* If the vector of fields is growing too big, bail out early.
4867 Callers check for VEC_length <= MAX_FIELDS_FOR_FIELD_SENSITIVE, make
4869 if (VEC_length (fieldoff_s, *fieldstack) > MAX_FIELDS_FOR_FIELD_SENSITIVE)
4872 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4873 if (TREE_CODE (field) == FIELD_DECL)
4876 HOST_WIDE_INT foff = bitpos_of_field (field);
4878 if (!var_can_have_subvars (field)
4879 || TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE
4880 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
4882 else if (!push_fields_onto_fieldstack
4883 (TREE_TYPE (field), fieldstack, offset + foff)
4884 && (DECL_SIZE (field)
4885 && !integer_zerop (DECL_SIZE (field))))
4886 /* Empty structures may have actual size, like in C++. So
4887 see if we didn't push any subfields and the size is
4888 nonzero, push the field onto the stack. */
4893 fieldoff_s *pair = NULL;
4894 bool has_unknown_size = false;
4896 if (!VEC_empty (fieldoff_s, *fieldstack))
4897 pair = VEC_last (fieldoff_s, *fieldstack);
4899 if (!DECL_SIZE (field)
4900 || !host_integerp (DECL_SIZE (field), 1))
4901 has_unknown_size = true;
4903 /* If adjacent fields do not contain pointers merge them. */
4905 && !pair->may_have_pointers
4906 && !pair->has_unknown_size
4907 && !has_unknown_size
4908 && pair->offset + (HOST_WIDE_INT)pair->size == offset + foff
4909 && !could_have_pointers (field))
4911 pair->size += TREE_INT_CST_LOW (DECL_SIZE (field));
4915 pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
4916 pair->offset = offset + foff;
4917 pair->has_unknown_size = has_unknown_size;
4918 if (!has_unknown_size)
4919 pair->size = TREE_INT_CST_LOW (DECL_SIZE (field));
4922 pair->may_have_pointers = could_have_pointers (field);
4923 pair->only_restrict_pointers
4924 = (!has_unknown_size
4925 && POINTER_TYPE_P (TREE_TYPE (field))
4926 && TYPE_RESTRICT (TREE_TYPE (field)));
4936 /* Count the number of arguments DECL has, and set IS_VARARGS to true
4937 if it is a varargs function. */
4940 count_num_arguments (tree decl, bool *is_varargs)
4942 unsigned int num = 0;
4945 /* Capture named arguments for K&R functions. They do not
4946 have a prototype and thus no TYPE_ARG_TYPES. */
4947 for (t = DECL_ARGUMENTS (decl); t; t = TREE_CHAIN (t))
4950 /* Check if the function has variadic arguments. */
4951 for (t = TYPE_ARG_TYPES (TREE_TYPE (decl)); t; t = TREE_CHAIN (t))
4952 if (TREE_VALUE (t) == void_type_node)
4960 /* Creation function node for DECL, using NAME, and return the index
4961 of the variable we've created for the function. */
4964 create_function_info_for (tree decl, const char *name)
4966 struct function *fn = DECL_STRUCT_FUNCTION (decl);
4967 varinfo_t vi, prev_vi;
4970 bool is_varargs = false;
4971 unsigned int num_args = count_num_arguments (decl, &is_varargs);
4973 /* Create the variable info. */
4975 vi = new_var_info (decl, name);
4978 vi->fullsize = fi_parm_base + num_args;
4980 vi->may_have_pointers = false;
4983 insert_vi_for_tree (vi->decl, vi);
4987 /* Create a variable for things the function clobbers and one for
4988 things the function uses. */
4990 varinfo_t clobbervi, usevi;
4991 const char *newname;
4994 asprintf (&tempname, "%s.clobber", name);
4995 newname = ggc_strdup (tempname);
4998 clobbervi = new_var_info (NULL, newname);
4999 clobbervi->offset = fi_clobbers;
5000 clobbervi->size = 1;
5001 clobbervi->fullsize = vi->fullsize;
5002 clobbervi->is_full_var = true;
5003 clobbervi->is_global_var = false;
5004 gcc_assert (prev_vi->offset < clobbervi->offset);
5005 prev_vi->next = clobbervi;
5006 prev_vi = clobbervi;
5008 asprintf (&tempname, "%s.use", name);
5009 newname = ggc_strdup (tempname);
5012 usevi = new_var_info (NULL, newname);
5013 usevi->offset = fi_uses;
5015 usevi->fullsize = vi->fullsize;
5016 usevi->is_full_var = true;
5017 usevi->is_global_var = false;
5018 gcc_assert (prev_vi->offset < usevi->offset);
5019 prev_vi->next = usevi;
5023 /* And one for the static chain. */
5024 if (fn->static_chain_decl != NULL_TREE)
5027 const char *newname;
5030 asprintf (&tempname, "%s.chain", name);
5031 newname = ggc_strdup (tempname);
5034 chainvi = new_var_info (fn->static_chain_decl, newname);
5035 chainvi->offset = fi_static_chain;
5037 chainvi->fullsize = vi->fullsize;
5038 chainvi->is_full_var = true;
5039 chainvi->is_global_var = false;
5040 gcc_assert (prev_vi->offset < chainvi->offset);
5041 prev_vi->next = chainvi;
5043 insert_vi_for_tree (fn->static_chain_decl, chainvi);
5046 /* Create a variable for the return var. */
5047 if (DECL_RESULT (decl) != NULL
5048 || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
5051 const char *newname;
5053 tree resultdecl = decl;
5055 if (DECL_RESULT (decl))
5056 resultdecl = DECL_RESULT (decl);
5058 asprintf (&tempname, "%s.result", name);
5059 newname = ggc_strdup (tempname);
5062 resultvi = new_var_info (resultdecl, newname);
5063 resultvi->offset = fi_result;
5065 resultvi->fullsize = vi->fullsize;
5066 resultvi->is_full_var = true;
5067 if (DECL_RESULT (decl))
5068 resultvi->may_have_pointers = could_have_pointers (DECL_RESULT (decl));
5069 gcc_assert (prev_vi->offset < resultvi->offset);
5070 prev_vi->next = resultvi;
5072 if (DECL_RESULT (decl))
5073 insert_vi_for_tree (DECL_RESULT (decl), resultvi);
5076 /* Set up variables for each argument. */
5077 arg = DECL_ARGUMENTS (decl);
5078 for (i = 0; i < num_args; i++)
5081 const char *newname;
5083 tree argdecl = decl;
5088 asprintf (&tempname, "%s.arg%d", name, i);
5089 newname = ggc_strdup (tempname);
5092 argvi = new_var_info (argdecl, newname);
5093 argvi->offset = fi_parm_base + i;
5095 argvi->is_full_var = true;
5096 argvi->fullsize = vi->fullsize;
5098 argvi->may_have_pointers = could_have_pointers (arg);
5099 gcc_assert (prev_vi->offset < argvi->offset);
5100 prev_vi->next = argvi;
5104 insert_vi_for_tree (arg, argvi);
5105 arg = TREE_CHAIN (arg);
5109 /* Add one representative for all further args. */
5113 const char *newname;
5117 asprintf (&tempname, "%s.varargs", name);
5118 newname = ggc_strdup (tempname);
5121 /* We need sth that can be pointed to for va_start. */
5122 decl = create_tmp_var_raw (ptr_type_node, name);
5125 argvi = new_var_info (decl, newname);
5126 argvi->offset = fi_parm_base + num_args;
5128 argvi->is_full_var = true;
5129 argvi->is_heap_var = true;
5130 argvi->fullsize = vi->fullsize;
5131 gcc_assert (prev_vi->offset < argvi->offset);
5132 prev_vi->next = argvi;
5140 /* Return true if FIELDSTACK contains fields that overlap.
5141 FIELDSTACK is assumed to be sorted by offset. */
5144 check_for_overlaps (VEC (fieldoff_s,heap) *fieldstack)
5146 fieldoff_s *fo = NULL;
5148 HOST_WIDE_INT lastoffset = -1;
5150 for (i = 0; VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
5152 if (fo->offset == lastoffset)
5154 lastoffset = fo->offset;
5159 /* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
5160 This will also create any varinfo structures necessary for fields
5164 create_variable_info_for_1 (tree decl, const char *name)
5166 varinfo_t vi, newvi;
5167 tree decl_type = TREE_TYPE (decl);
5168 tree declsize = DECL_P (decl) ? DECL_SIZE (decl) : TYPE_SIZE (decl_type);
5169 VEC (fieldoff_s,heap) *fieldstack = NULL;
5174 || !host_integerp (declsize, 1))
5176 vi = new_var_info (decl, name);
5180 vi->is_unknown_size_var = true;
5181 vi->is_full_var = true;
5182 vi->may_have_pointers = could_have_pointers (decl);
5186 /* Collect field information. */
5187 if (use_field_sensitive
5188 && var_can_have_subvars (decl)
5189 /* ??? Force us to not use subfields for global initializers
5190 in IPA mode. Else we'd have to parse arbitrary initializers. */
5192 && is_global_var (decl)
5193 && DECL_INITIAL (decl)))
5195 fieldoff_s *fo = NULL;
5196 bool notokay = false;
5199 push_fields_onto_fieldstack (decl_type, &fieldstack, 0);
5201 for (i = 0; !notokay && VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
5202 if (fo->has_unknown_size
5209 /* We can't sort them if we have a field with a variable sized type,
5210 which will make notokay = true. In that case, we are going to return
5211 without creating varinfos for the fields anyway, so sorting them is a
5215 sort_fieldstack (fieldstack);
5216 /* Due to some C++ FE issues, like PR 22488, we might end up
5217 what appear to be overlapping fields even though they,
5218 in reality, do not overlap. Until the C++ FE is fixed,
5219 we will simply disable field-sensitivity for these cases. */
5220 notokay = check_for_overlaps (fieldstack);
5224 VEC_free (fieldoff_s, heap, fieldstack);
5227 /* If we didn't end up collecting sub-variables create a full
5228 variable for the decl. */
5229 if (VEC_length (fieldoff_s, fieldstack) <= 1
5230 || VEC_length (fieldoff_s, fieldstack) > MAX_FIELDS_FOR_FIELD_SENSITIVE)
5232 vi = new_var_info (decl, name);
5234 vi->may_have_pointers = could_have_pointers (decl);
5235 vi->fullsize = TREE_INT_CST_LOW (declsize);
5236 vi->size = vi->fullsize;
5237 vi->is_full_var = true;
5238 VEC_free (fieldoff_s, heap, fieldstack);
5242 vi = new_var_info (decl, name);
5243 vi->fullsize = TREE_INT_CST_LOW (declsize);
5244 for (i = 0, newvi = vi;
5245 VEC_iterate (fieldoff_s, fieldstack, i, fo);
5246 ++i, newvi = newvi->next)
5248 const char *newname = "NULL";
5253 asprintf (&tempname, "%s." HOST_WIDE_INT_PRINT_DEC
5254 "+" HOST_WIDE_INT_PRINT_DEC, name, fo->offset, fo->size);
5255 newname = ggc_strdup (tempname);
5258 newvi->name = newname;
5259 newvi->offset = fo->offset;
5260 newvi->size = fo->size;
5261 newvi->fullsize = vi->fullsize;
5262 newvi->may_have_pointers = fo->may_have_pointers;
5263 newvi->only_restrict_pointers = fo->only_restrict_pointers;
5264 if (i + 1 < VEC_length (fieldoff_s, fieldstack))
5265 newvi->next = new_var_info (decl, name);
5268 VEC_free (fieldoff_s, heap, fieldstack);
5274 create_variable_info_for (tree decl, const char *name)
5276 varinfo_t vi = create_variable_info_for_1 (decl, name);
5277 unsigned int id = vi->id;
5279 insert_vi_for_tree (decl, vi);
5281 /* Create initial constraints for globals. */
5282 for (; vi; vi = vi->next)
5284 if (!vi->may_have_pointers
5285 || !vi->is_global_var)
5288 /* Mark global restrict qualified pointers. */
5289 if ((POINTER_TYPE_P (TREE_TYPE (decl))
5290 && TYPE_RESTRICT (TREE_TYPE (decl)))
5291 || vi->only_restrict_pointers)
5292 make_constraint_from_restrict (vi, "GLOBAL_RESTRICT");
5294 /* For escaped variables initialize them from nonlocal. */
5296 || DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
5297 make_copy_constraint (vi, nonlocal_id);
5299 /* If this is a global variable with an initializer and we are in
5300 IPA mode generate constraints for it. In non-IPA mode
5301 the initializer from nonlocal is all we need. */
5303 && DECL_INITIAL (decl))
5305 VEC (ce_s, heap) *rhsc = NULL;
5306 struct constraint_expr lhs, *rhsp;
5308 get_constraint_for (DECL_INITIAL (decl), &rhsc);
5312 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
5313 process_constraint (new_constraint (lhs, *rhsp));
5314 /* If this is a variable that escapes from the unit
5315 the initializer escapes as well. */
5316 if (DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
5318 lhs.var = escaped_id;
5321 for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
5322 process_constraint (new_constraint (lhs, *rhsp));
5324 VEC_free (ce_s, heap, rhsc);
5331 /* Print out the points-to solution for VAR to FILE. */
5334 dump_solution_for_var (FILE *file, unsigned int var)
5336 varinfo_t vi = get_varinfo (var);
5340 /* Dump the solution for unified vars anyway, this avoids difficulties
5341 in scanning dumps in the testsuite. */
5342 fprintf (file, "%s = { ", vi->name);
5343 vi = get_varinfo (find (var));
5344 EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
5345 fprintf (file, "%s ", get_varinfo (i)->name);
5346 fprintf (file, "}");
5348 /* But note when the variable was unified. */
5350 fprintf (file, " same as %s", vi->name);
5352 fprintf (file, "\n");
5355 /* Print the points-to solution for VAR to stdout. */
5358 debug_solution_for_var (unsigned int var)
5360 dump_solution_for_var (stdout, var);
5363 /* Create varinfo structures for all of the variables in the
5364 function for intraprocedural mode. */
5367 intra_create_variable_infos (void)
5371 /* For each incoming pointer argument arg, create the constraint ARG
5372 = NONLOCAL or a dummy variable if it is a restrict qualified
5373 passed-by-reference argument. */
5374 for (t = DECL_ARGUMENTS (current_function_decl); t; t = TREE_CHAIN (t))
5378 if (!could_have_pointers (t))
5381 /* For restrict qualified pointers to objects passed by
5382 reference build a real representative for the pointed-to object. */
5383 if (DECL_BY_REFERENCE (t)
5384 && POINTER_TYPE_P (TREE_TYPE (t))
5385 && TYPE_RESTRICT (TREE_TYPE (t)))
5387 struct constraint_expr lhsc, rhsc;
5389 tree heapvar = heapvar_lookup (t, 0);
5390 if (heapvar == NULL_TREE)
5393 heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)),
5395 DECL_EXTERNAL (heapvar) = 1;
5396 heapvar_insert (t, 0, heapvar);
5397 ann = get_var_ann (heapvar);
5398 ann->is_heapvar = 1;
5400 if (gimple_referenced_vars (cfun))
5401 add_referenced_var (heapvar);
5402 lhsc.var = get_vi_for_tree (t)->id;
5405 rhsc.var = (vi = get_vi_for_tree (heapvar))->id;
5406 rhsc.type = ADDRESSOF;
5408 process_constraint (new_constraint (lhsc, rhsc));
5409 vi->is_restrict_var = 1;
5413 for (p = get_vi_for_tree (t); p; p = p->next)
5415 if (p->may_have_pointers)
5416 make_constraint_from (p, nonlocal_id);
5417 if (p->only_restrict_pointers)
5418 make_constraint_from_restrict (p, "PARM_RESTRICT");
5420 if (POINTER_TYPE_P (TREE_TYPE (t))
5421 && TYPE_RESTRICT (TREE_TYPE (t)))
5422 make_constraint_from_restrict (get_vi_for_tree (t), "PARM_RESTRICT");
5425 /* Add a constraint for a result decl that is passed by reference. */
5426 if (DECL_RESULT (cfun->decl)
5427 && DECL_BY_REFERENCE (DECL_RESULT (cfun->decl)))
5429 varinfo_t p, result_vi = get_vi_for_tree (DECL_RESULT (cfun->decl));
5431 for (p = result_vi; p; p = p->next)
5432 make_constraint_from (p, nonlocal_id);
5435 /* Add a constraint for the incoming static chain parameter. */
5436 if (cfun->static_chain_decl != NULL_TREE)
5438 varinfo_t p, chain_vi = get_vi_for_tree (cfun->static_chain_decl);
5440 for (p = chain_vi; p; p = p->next)
5441 make_constraint_from (p, nonlocal_id);
5445 /* Structure used to put solution bitmaps in a hashtable so they can
5446 be shared among variables with the same points-to set. */
5448 typedef struct shared_bitmap_info
5452 } *shared_bitmap_info_t;
5453 typedef const struct shared_bitmap_info *const_shared_bitmap_info_t;
5455 static htab_t shared_bitmap_table;
5457 /* Hash function for a shared_bitmap_info_t */
5460 shared_bitmap_hash (const void *p)
5462 const_shared_bitmap_info_t const bi = (const_shared_bitmap_info_t) p;
5463 return bi->hashcode;
5466 /* Equality function for two shared_bitmap_info_t's. */
5469 shared_bitmap_eq (const void *p1, const void *p2)
5471 const_shared_bitmap_info_t const sbi1 = (const_shared_bitmap_info_t) p1;
5472 const_shared_bitmap_info_t const sbi2 = (const_shared_bitmap_info_t) p2;
5473 return bitmap_equal_p (sbi1->pt_vars, sbi2->pt_vars);
5476 /* Lookup a bitmap in the shared bitmap hashtable, and return an already
5477 existing instance if there is one, NULL otherwise. */
5480 shared_bitmap_lookup (bitmap pt_vars)
5483 struct shared_bitmap_info sbi;
5485 sbi.pt_vars = pt_vars;
5486 sbi.hashcode = bitmap_hash (pt_vars);
5488 slot = htab_find_slot_with_hash (shared_bitmap_table, &sbi,
5489 sbi.hashcode, NO_INSERT);
5493 return ((shared_bitmap_info_t) *slot)->pt_vars;
5497 /* Add a bitmap to the shared bitmap hashtable. */
5500 shared_bitmap_add (bitmap pt_vars)
5503 shared_bitmap_info_t sbi = XNEW (struct shared_bitmap_info);
5505 sbi->pt_vars = pt_vars;
5506 sbi->hashcode = bitmap_hash (pt_vars);
5508 slot = htab_find_slot_with_hash (shared_bitmap_table, sbi,
5509 sbi->hashcode, INSERT);
5510 gcc_assert (!*slot);
5511 *slot = (void *) sbi;
5515 /* Set bits in INTO corresponding to the variable uids in solution set FROM. */
5518 set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt)
5523 EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
5525 varinfo_t vi = get_varinfo (i);
5527 /* The only artificial variables that are allowed in a may-alias
5528 set are heap variables. */
5529 if (vi->is_artificial_var && !vi->is_heap_var)
5532 if (TREE_CODE (vi->decl) == VAR_DECL
5533 || TREE_CODE (vi->decl) == PARM_DECL
5534 || TREE_CODE (vi->decl) == RESULT_DECL)
5536 /* If we are in IPA mode we will not recompute points-to
5537 sets after inlining so make sure they stay valid. */
5539 && !DECL_PT_UID_SET_P (vi->decl))
5540 SET_DECL_PT_UID (vi->decl, DECL_UID (vi->decl));
5542 /* Add the decl to the points-to set. Note that the points-to
5543 set contains global variables. */
5544 bitmap_set_bit (into, DECL_PT_UID (vi->decl));
5545 if (vi->is_global_var)
5546 pt->vars_contains_global = true;
5552 /* Compute the points-to solution *PT for the variable VI. */
5555 find_what_var_points_to (varinfo_t orig_vi, struct pt_solution *pt)
5559 bitmap finished_solution;
5563 memset (pt, 0, sizeof (struct pt_solution));
5565 /* This variable may have been collapsed, let's get the real
5567 vi = get_varinfo (find (orig_vi->id));
5569 /* Translate artificial variables into SSA_NAME_PTR_INFO
5571 EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
5573 varinfo_t vi = get_varinfo (i);
5575 if (vi->is_artificial_var)
5577 if (vi->id == nothing_id)
5579 else if (vi->id == escaped_id)
5582 pt->ipa_escaped = 1;
5586 else if (vi->id == nonlocal_id)
5588 else if (vi->is_heap_var)
5589 /* We represent heapvars in the points-to set properly. */
5591 else if (vi->id == readonly_id)
5594 else if (vi->id == anything_id
5595 || vi->id == integer_id)
5598 if (vi->is_restrict_var)
5599 pt->vars_contains_restrict = true;
5602 /* Instead of doing extra work, simply do not create
5603 elaborate points-to information for pt_anything pointers. */
5605 && (orig_vi->is_artificial_var
5606 || !pt->vars_contains_restrict))
5609 /* Share the final set of variables when possible. */
5610 finished_solution = BITMAP_GGC_ALLOC ();
5611 stats.points_to_sets_created++;
5613 set_uids_in_ptset (finished_solution, vi->solution, pt);
5614 result = shared_bitmap_lookup (finished_solution);
5617 shared_bitmap_add (finished_solution);
5618 pt->vars = finished_solution;
5623 bitmap_clear (finished_solution);
5627 /* Given a pointer variable P, fill in its points-to set. */
5630 find_what_p_points_to (tree p)
5632 struct ptr_info_def *pi;
5636 /* For parameters, get at the points-to set for the actual parm
5638 if (TREE_CODE (p) == SSA_NAME
5639 && TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL
5640 && SSA_NAME_IS_DEFAULT_DEF (p))
5641 lookup_p = SSA_NAME_VAR (p);
5643 vi = lookup_vi_for_tree (lookup_p);
5647 pi = get_ptr_info (p);
5648 find_what_var_points_to (vi, &pi->pt);
5652 /* Query statistics for points-to solutions. */
5655 unsigned HOST_WIDE_INT pt_solution_includes_may_alias;
5656 unsigned HOST_WIDE_INT pt_solution_includes_no_alias;
5657 unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias;
5658 unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias;
5662 dump_pta_stats (FILE *s)
5664 fprintf (s, "\nPTA query stats:\n");
5665 fprintf (s, " pt_solution_includes: "
5666 HOST_WIDE_INT_PRINT_DEC" disambiguations, "
5667 HOST_WIDE_INT_PRINT_DEC" queries\n",
5668 pta_stats.pt_solution_includes_no_alias,
5669 pta_stats.pt_solution_includes_no_alias
5670 + pta_stats.pt_solution_includes_may_alias);
5671 fprintf (s, " pt_solutions_intersect: "
5672 HOST_WIDE_INT_PRINT_DEC" disambiguations, "
5673 HOST_WIDE_INT_PRINT_DEC" queries\n",
5674 pta_stats.pt_solutions_intersect_no_alias,
5675 pta_stats.pt_solutions_intersect_no_alias
5676 + pta_stats.pt_solutions_intersect_may_alias);
5680 /* Reset the points-to solution *PT to a conservative default
5681 (point to anything). */
5684 pt_solution_reset (struct pt_solution *pt)
5686 memset (pt, 0, sizeof (struct pt_solution));
5687 pt->anything = true;
5690 /* Set the points-to solution *PT to point only to the variables
5691 in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
5692 global variables and VARS_CONTAINS_RESTRICT specifies whether
5693 it contains restrict tag variables. */
5696 pt_solution_set (struct pt_solution *pt, bitmap vars,
5697 bool vars_contains_global, bool vars_contains_restrict)
5699 memset (pt, 0, sizeof (struct pt_solution));
5701 pt->vars_contains_global = vars_contains_global;
5702 pt->vars_contains_restrict = vars_contains_restrict;
5705 /* Computes the union of the points-to solutions *DEST and *SRC and
5706 stores the result in *DEST. This changes the points-to bitmap
5707 of *DEST and thus may not be used if that might be shared.
5708 The points-to bitmap of *SRC and *DEST will not be shared after
5709 this function if they were not before. */
5712 pt_solution_ior_into (struct pt_solution *dest, struct pt_solution *src)
5714 dest->anything |= src->anything;
5717 pt_solution_reset (dest);
5721 dest->nonlocal |= src->nonlocal;
5722 dest->escaped |= src->escaped;
5723 dest->ipa_escaped |= src->ipa_escaped;
5724 dest->null |= src->null;
5725 dest->vars_contains_global |= src->vars_contains_global;
5726 dest->vars_contains_restrict |= src->vars_contains_restrict;
5731 dest->vars = BITMAP_GGC_ALLOC ();
5732 bitmap_ior_into (dest->vars, src->vars);
5735 /* Return true if the points-to solution *PT is empty. */
5738 pt_solution_empty_p (struct pt_solution *pt)
5745 && !bitmap_empty_p (pt->vars))
5748 /* If the solution includes ESCAPED, check if that is empty. */
5750 && !pt_solution_empty_p (&cfun->gimple_df->escaped))
5753 /* If the solution includes ESCAPED, check if that is empty. */
5755 && !pt_solution_empty_p (&ipa_escaped_pt))
5761 /* Return true if the points-to solution *PT includes global memory. */
5764 pt_solution_includes_global (struct pt_solution *pt)
5768 || pt->vars_contains_global)
5772 return pt_solution_includes_global (&cfun->gimple_df->escaped);
5774 if (pt->ipa_escaped)
5775 return pt_solution_includes_global (&ipa_escaped_pt);
5777 /* ??? This predicate is not correct for the IPA-PTA solution
5778 as we do not properly distinguish between unit escape points
5779 and global variables. */
5780 if (cfun->gimple_df->ipa_pta)
5786 /* Return true if the points-to solution *PT includes the variable
5787 declaration DECL. */
5790 pt_solution_includes_1 (struct pt_solution *pt, const_tree decl)
5796 && is_global_var (decl))
5800 && bitmap_bit_p (pt->vars, DECL_PT_UID (decl)))
5803 /* If the solution includes ESCAPED, check it. */
5805 && pt_solution_includes_1 (&cfun->gimple_df->escaped, decl))
5808 /* If the solution includes ESCAPED, check it. */
5810 && pt_solution_includes_1 (&ipa_escaped_pt, decl))
5817 pt_solution_includes (struct pt_solution *pt, const_tree decl)
5819 bool res = pt_solution_includes_1 (pt, decl);
5821 ++pta_stats.pt_solution_includes_may_alias;
5823 ++pta_stats.pt_solution_includes_no_alias;
5827 /* Return true if both points-to solutions PT1 and PT2 have a non-empty
5831 pt_solutions_intersect_1 (struct pt_solution *pt1, struct pt_solution *pt2)
5833 if (pt1->anything || pt2->anything)
5836 /* If either points to unknown global memory and the other points to
5837 any global memory they alias. */
5840 || pt2->vars_contains_global))
5842 && pt1->vars_contains_global))
5845 /* Check the escaped solution if required. */
5846 if ((pt1->escaped || pt2->escaped)
5847 && !pt_solution_empty_p (&cfun->gimple_df->escaped))
5849 /* If both point to escaped memory and that solution
5850 is not empty they alias. */
5851 if (pt1->escaped && pt2->escaped)
5854 /* If either points to escaped memory see if the escaped solution
5855 intersects with the other. */
5857 && pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt2))
5859 && pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt1)))
5863 /* Check the escaped solution if required.
5864 ??? Do we need to check the local against the IPA escaped sets? */
5865 if ((pt1->ipa_escaped || pt2->ipa_escaped)
5866 && !pt_solution_empty_p (&ipa_escaped_pt))
5868 /* If both point to escaped memory and that solution
5869 is not empty they alias. */
5870 if (pt1->ipa_escaped && pt2->ipa_escaped)
5873 /* If either points to escaped memory see if the escaped solution
5874 intersects with the other. */
5875 if ((pt1->ipa_escaped
5876 && pt_solutions_intersect_1 (&ipa_escaped_pt, pt2))
5877 || (pt2->ipa_escaped
5878 && pt_solutions_intersect_1 (&ipa_escaped_pt, pt1)))
5882 /* Now both pointers alias if their points-to solution intersects. */
5885 && bitmap_intersect_p (pt1->vars, pt2->vars));
5889 pt_solutions_intersect (struct pt_solution *pt1, struct pt_solution *pt2)
5891 bool res = pt_solutions_intersect_1 (pt1, pt2);
5893 ++pta_stats.pt_solutions_intersect_may_alias;
5895 ++pta_stats.pt_solutions_intersect_no_alias;
5899 /* Return true if both points-to solutions PT1 and PT2 for two restrict
5900 qualified pointers are possibly based on the same pointer. */
5903 pt_solutions_same_restrict_base (struct pt_solution *pt1,
5904 struct pt_solution *pt2)
5906 /* If we deal with points-to solutions of two restrict qualified
5907 pointers solely rely on the pointed-to variable bitmap intersection.
5908 For two pointers that are based on each other the bitmaps will
5910 if (pt1->vars_contains_restrict
5911 && pt2->vars_contains_restrict)
5913 gcc_assert (pt1->vars && pt2->vars);
5914 return bitmap_intersect_p (pt1->vars, pt2->vars);
5921 /* Dump points-to information to OUTFILE. */
5924 dump_sa_points_to_info (FILE *outfile)
5928 fprintf (outfile, "\nPoints-to sets\n\n");
5930 if (dump_flags & TDF_STATS)
5932 fprintf (outfile, "Stats:\n");
5933 fprintf (outfile, "Total vars: %d\n", stats.total_vars);
5934 fprintf (outfile, "Non-pointer vars: %d\n",
5935 stats.nonpointer_vars);
5936 fprintf (outfile, "Statically unified vars: %d\n",
5937 stats.unified_vars_static);
5938 fprintf (outfile, "Dynamically unified vars: %d\n",
5939 stats.unified_vars_dynamic);
5940 fprintf (outfile, "Iterations: %d\n", stats.iterations);
5941 fprintf (outfile, "Number of edges: %d\n", stats.num_edges);
5942 fprintf (outfile, "Number of implicit edges: %d\n",
5943 stats.num_implicit_edges);
5946 for (i = 0; i < VEC_length (varinfo_t, varmap); i++)
5948 varinfo_t vi = get_varinfo (i);
5949 if (!vi->may_have_pointers)
5951 dump_solution_for_var (outfile, i);
5956 /* Debug points-to information to stderr. */
5959 debug_sa_points_to_info (void)
5961 dump_sa_points_to_info (stderr);
5965 /* Initialize the always-existing constraint variables for NULL
5966 ANYTHING, READONLY, and INTEGER */
5969 init_base_vars (void)
5971 struct constraint_expr lhs, rhs;
5972 varinfo_t var_anything;
5973 varinfo_t var_nothing;
5974 varinfo_t var_readonly;
5975 varinfo_t var_escaped;
5976 varinfo_t var_nonlocal;
5977 varinfo_t var_storedanything;
5978 varinfo_t var_integer;
5980 /* Create the NULL variable, used to represent that a variable points
5982 var_nothing = new_var_info (NULL_TREE, "NULL");
5983 gcc_assert (var_nothing->id == nothing_id);
5984 var_nothing->is_artificial_var = 1;
5985 var_nothing->offset = 0;
5986 var_nothing->size = ~0;
5987 var_nothing->fullsize = ~0;
5988 var_nothing->is_special_var = 1;
5989 var_nothing->may_have_pointers = 0;
5990 var_nothing->is_global_var = 0;
5992 /* Create the ANYTHING variable, used to represent that a variable
5993 points to some unknown piece of memory. */
5994 var_anything = new_var_info (NULL_TREE, "ANYTHING");
5995 gcc_assert (var_anything->id == anything_id);
5996 var_anything->is_artificial_var = 1;
5997 var_anything->size = ~0;
5998 var_anything->offset = 0;
5999 var_anything->next = NULL;
6000 var_anything->fullsize = ~0;
6001 var_anything->is_special_var = 1;
6003 /* Anything points to anything. This makes deref constraints just
6004 work in the presence of linked list and other p = *p type loops,
6005 by saying that *ANYTHING = ANYTHING. */
6007 lhs.var = anything_id;
6009 rhs.type = ADDRESSOF;
6010 rhs.var = anything_id;
6013 /* This specifically does not use process_constraint because
6014 process_constraint ignores all anything = anything constraints, since all
6015 but this one are redundant. */
6016 VEC_safe_push (constraint_t, heap, constraints, new_constraint (lhs, rhs));
6018 /* Create the READONLY variable, used to represent that a variable
6019 points to readonly memory. */
6020 var_readonly = new_var_info (NULL_TREE, "READONLY");
6021 gcc_assert (var_readonly->id == readonly_id);
6022 var_readonly->is_artificial_var = 1;
6023 var_readonly->offset = 0;
6024 var_readonly->size = ~0;
6025 var_readonly->fullsize = ~0;
6026 var_readonly->next = NULL;
6027 var_readonly->is_special_var = 1;
6029 /* readonly memory points to anything, in order to make deref
6030 easier. In reality, it points to anything the particular
6031 readonly variable can point to, but we don't track this
6034 lhs.var = readonly_id;
6036 rhs.type = ADDRESSOF;
6037 rhs.var = readonly_id; /* FIXME */
6039 process_constraint (new_constraint (lhs, rhs));
6041 /* Create the ESCAPED variable, used to represent the set of escaped
6043 var_escaped = new_var_info (NULL_TREE, "ESCAPED");
6044 gcc_assert (var_escaped->id == escaped_id);
6045 var_escaped->is_artificial_var = 1;
6046 var_escaped->offset = 0;
6047 var_escaped->size = ~0;
6048 var_escaped->fullsize = ~0;
6049 var_escaped->is_special_var = 0;
6051 /* Create the NONLOCAL variable, used to represent the set of nonlocal
6053 var_nonlocal = new_var_info (NULL_TREE, "NONLOCAL");
6054 gcc_assert (var_nonlocal->id == nonlocal_id);
6055 var_nonlocal->is_artificial_var = 1;
6056 var_nonlocal->offset = 0;
6057 var_nonlocal->size = ~0;
6058 var_nonlocal->fullsize = ~0;
6059 var_nonlocal->is_special_var = 1;
6061 /* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
6063 lhs.var = escaped_id;
6066 rhs.var = escaped_id;
6068 process_constraint (new_constraint (lhs, rhs));
6070 /* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
6071 whole variable escapes. */
6073 lhs.var = escaped_id;
6076 rhs.var = escaped_id;
6077 rhs.offset = UNKNOWN_OFFSET;
6078 process_constraint (new_constraint (lhs, rhs));
6080 /* *ESCAPED = NONLOCAL. This is true because we have to assume
6081 everything pointed to by escaped points to what global memory can
6084 lhs.var = escaped_id;
6087 rhs.var = nonlocal_id;
6089 process_constraint (new_constraint (lhs, rhs));
6091 /* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
6092 global memory may point to global memory and escaped memory. */
6094 lhs.var = nonlocal_id;
6096 rhs.type = ADDRESSOF;
6097 rhs.var = nonlocal_id;
6099 process_constraint (new_constraint (lhs, rhs));
6100 rhs.type = ADDRESSOF;
6101 rhs.var = escaped_id;
6103 process_constraint (new_constraint (lhs, rhs));
6105 /* Create the STOREDANYTHING variable, used to represent the set of
6106 variables stored to *ANYTHING. */
6107 var_storedanything = new_var_info (NULL_TREE, "STOREDANYTHING");
6108 gcc_assert (var_storedanything->id == storedanything_id);
6109 var_storedanything->is_artificial_var = 1;
6110 var_storedanything->offset = 0;
6111 var_storedanything->size = ~0;
6112 var_storedanything->fullsize = ~0;
6113 var_storedanything->is_special_var = 0;
6115 /* Create the INTEGER variable, used to represent that a variable points
6116 to what an INTEGER "points to". */
6117 var_integer = new_var_info (NULL_TREE, "INTEGER");
6118 gcc_assert (var_integer->id == integer_id);
6119 var_integer->is_artificial_var = 1;
6120 var_integer->size = ~0;
6121 var_integer->fullsize = ~0;
6122 var_integer->offset = 0;
6123 var_integer->next = NULL;
6124 var_integer->is_special_var = 1;
6126 /* INTEGER = ANYTHING, because we don't know where a dereference of
6127 a random integer will point to. */
6129 lhs.var = integer_id;
6131 rhs.type = ADDRESSOF;
6132 rhs.var = anything_id;
6134 process_constraint (new_constraint (lhs, rhs));
6137 /* Initialize things necessary to perform PTA */
6140 init_alias_vars (void)
6142 use_field_sensitive = (MAX_FIELDS_FOR_FIELD_SENSITIVE > 1);
6144 bitmap_obstack_initialize (&pta_obstack);
6145 bitmap_obstack_initialize (&oldpta_obstack);
6146 bitmap_obstack_initialize (&predbitmap_obstack);
6148 constraint_pool = create_alloc_pool ("Constraint pool",
6149 sizeof (struct constraint), 30);
6150 variable_info_pool = create_alloc_pool ("Variable info pool",
6151 sizeof (struct variable_info), 30);
6152 constraints = VEC_alloc (constraint_t, heap, 8);
6153 varmap = VEC_alloc (varinfo_t, heap, 8);
6154 vi_for_tree = pointer_map_create ();
6155 call_stmt_vars = pointer_map_create ();
6157 memset (&stats, 0, sizeof (stats));
6158 shared_bitmap_table = htab_create (511, shared_bitmap_hash,
6159 shared_bitmap_eq, free);
6163 /* Remove the REF and ADDRESS edges from GRAPH, as well as all the
6164 predecessor edges. */
6167 remove_preds_and_fake_succs (constraint_graph_t graph)
6171 /* Clear the implicit ref and address nodes from the successor
6173 for (i = 0; i < FIRST_REF_NODE; i++)
6175 if (graph->succs[i])
6176 bitmap_clear_range (graph->succs[i], FIRST_REF_NODE,
6177 FIRST_REF_NODE * 2);
6180 /* Free the successor list for the non-ref nodes. */
6181 for (i = FIRST_REF_NODE; i < graph->size; i++)
6183 if (graph->succs[i])
6184 BITMAP_FREE (graph->succs[i]);
6187 /* Now reallocate the size of the successor list as, and blow away
6188 the predecessor bitmaps. */
6189 graph->size = VEC_length (varinfo_t, varmap);
6190 graph->succs = XRESIZEVEC (bitmap, graph->succs, graph->size);
6192 free (graph->implicit_preds);
6193 graph->implicit_preds = NULL;
6194 free (graph->preds);
6195 graph->preds = NULL;
6196 bitmap_obstack_release (&predbitmap_obstack);
6199 /* Initialize the heapvar for statement mapping. */
6202 init_alias_heapvars (void)
6204 if (!heapvar_for_stmt)
6205 heapvar_for_stmt = htab_create_ggc (11, tree_map_hash, heapvar_map_eq,
6209 /* Delete the heapvar for statement mapping. */
6212 delete_alias_heapvars (void)
6214 if (heapvar_for_stmt)
6215 htab_delete (heapvar_for_stmt);
6216 heapvar_for_stmt = NULL;
6219 /* Solve the constraint set. */
6222 solve_constraints (void)
6224 struct scc_info *si;
6228 "\nCollapsing static cycles and doing variable "
6231 init_graph (VEC_length (varinfo_t, varmap) * 2);
6234 fprintf (dump_file, "Building predecessor graph\n");
6235 build_pred_graph ();
6238 fprintf (dump_file, "Detecting pointer and location "
6240 si = perform_var_substitution (graph);
6243 fprintf (dump_file, "Rewriting constraints and unifying "
6245 rewrite_constraints (graph, si);
6247 build_succ_graph ();
6248 free_var_substitution_info (si);
6250 if (dump_file && (dump_flags & TDF_GRAPH))
6251 dump_constraint_graph (dump_file);
6253 move_complex_constraints (graph);
6256 fprintf (dump_file, "Uniting pointer but not location equivalent "
6258 unite_pointer_equivalences (graph);
6261 fprintf (dump_file, "Finding indirect cycles\n");
6262 find_indirect_cycles (graph);
6264 /* Implicit nodes and predecessors are no longer necessary at this
6266 remove_preds_and_fake_succs (graph);
6269 fprintf (dump_file, "Solving graph\n");
6271 solve_graph (graph);
6274 dump_sa_points_to_info (dump_file);
6277 /* Create points-to sets for the current function. See the comments
6278 at the start of the file for an algorithmic overview. */
6281 compute_points_to_sets (void)
6287 timevar_push (TV_TREE_PTA);
6290 init_alias_heapvars ();
6292 intra_create_variable_infos ();
6294 /* Now walk all statements and build the constraint set. */
6297 gimple_stmt_iterator gsi;
6299 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6301 gimple phi = gsi_stmt (gsi);
6303 if (is_gimple_reg (gimple_phi_result (phi)))
6304 find_func_aliases (phi);
6307 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6309 gimple stmt = gsi_stmt (gsi);
6311 find_func_aliases (stmt);
6317 fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
6318 dump_constraints (dump_file, 0);
6321 /* From the constraints compute the points-to sets. */
6322 solve_constraints ();
6324 /* Compute the points-to set for ESCAPED used for call-clobber analysis. */
6325 find_what_var_points_to (get_varinfo (escaped_id),
6326 &cfun->gimple_df->escaped);
6328 /* Make sure the ESCAPED solution (which is used as placeholder in
6329 other solutions) does not reference itself. This simplifies
6330 points-to solution queries. */
6331 cfun->gimple_df->escaped.escaped = 0;
6333 /* Mark escaped HEAP variables as global. */
6334 for (i = 0; VEC_iterate (varinfo_t, varmap, i, vi); ++i)
6336 && !vi->is_restrict_var
6337 && !vi->is_global_var)
6338 DECL_EXTERNAL (vi->decl) = vi->is_global_var
6339 = pt_solution_includes (&cfun->gimple_df->escaped, vi->decl);
6341 /* Compute the points-to sets for pointer SSA_NAMEs. */
6342 for (i = 0; i < num_ssa_names; ++i)
6344 tree ptr = ssa_name (i);
6346 && POINTER_TYPE_P (TREE_TYPE (ptr)))
6347 find_what_p_points_to (ptr);
6350 /* Compute the call-used/clobbered sets. */
6353 gimple_stmt_iterator gsi;
6355 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6357 gimple stmt = gsi_stmt (gsi);
6358 struct pt_solution *pt;
6359 if (!is_gimple_call (stmt))
6362 pt = gimple_call_use_set (stmt);
6363 if (gimple_call_flags (stmt) & ECF_CONST)
6364 memset (pt, 0, sizeof (struct pt_solution));
6365 else if ((vi = lookup_call_use_vi (stmt)) != NULL)
6367 find_what_var_points_to (vi, pt);
6368 /* Escaped (and thus nonlocal) variables are always
6369 implicitly used by calls. */
6370 /* ??? ESCAPED can be empty even though NONLOCAL
6377 /* If there is nothing special about this call then
6378 we have made everything that is used also escape. */
6379 *pt = cfun->gimple_df->escaped;
6383 pt = gimple_call_clobber_set (stmt);
6384 if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
6385 memset (pt, 0, sizeof (struct pt_solution));
6386 else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
6388 find_what_var_points_to (vi, pt);
6389 /* Escaped (and thus nonlocal) variables are always
6390 implicitly clobbered by calls. */
6391 /* ??? ESCAPED can be empty even though NONLOCAL
6398 /* If there is nothing special about this call then
6399 we have made everything that is used also escape. */
6400 *pt = cfun->gimple_df->escaped;
6406 timevar_pop (TV_TREE_PTA);
6410 /* Delete created points-to sets. */
6413 delete_points_to_sets (void)
6417 htab_delete (shared_bitmap_table);
6418 if (dump_file && (dump_flags & TDF_STATS))
6419 fprintf (dump_file, "Points to sets created:%d\n",
6420 stats.points_to_sets_created);
6422 pointer_map_destroy (vi_for_tree);
6423 pointer_map_destroy (call_stmt_vars);
6424 bitmap_obstack_release (&pta_obstack);
6425 VEC_free (constraint_t, heap, constraints);
6427 for (i = 0; i < graph->size; i++)
6428 VEC_free (constraint_t, heap, graph->complex[i]);
6429 free (graph->complex);
6432 free (graph->succs);
6434 free (graph->pe_rep);
6435 free (graph->indirect_cycles);
6438 VEC_free (varinfo_t, heap, varmap);
6439 free_alloc_pool (variable_info_pool);
6440 free_alloc_pool (constraint_pool);
6444 /* Compute points-to information for every SSA_NAME pointer in the
6445 current function and compute the transitive closure of escaped
6446 variables to re-initialize the call-clobber states of local variables. */
6449 compute_may_aliases (void)
6451 if (cfun->gimple_df->ipa_pta)
6455 fprintf (dump_file, "\nNot re-computing points-to information "
6456 "because IPA points-to information is available.\n\n");
6458 /* But still dump what we have remaining it. */
6459 dump_alias_info (dump_file);
6461 if (dump_flags & TDF_DETAILS)
6462 dump_referenced_vars (dump_file);
6468 /* For each pointer P_i, determine the sets of variables that P_i may
6469 point-to. Compute the reachability set of escaped and call-used
6471 compute_points_to_sets ();
6473 /* Debugging dumps. */
6476 dump_alias_info (dump_file);
6478 if (dump_flags & TDF_DETAILS)
6479 dump_referenced_vars (dump_file);
6482 /* Deallocate memory used by aliasing data structures and the internal
6483 points-to solution. */
6484 delete_points_to_sets ();
6486 gcc_assert (!need_ssa_update_p (cfun));
6492 gate_tree_pta (void)
6494 return flag_tree_pta;
6497 /* A dummy pass to cause points-to information to be computed via
6498 TODO_rebuild_alias. */
6500 struct gimple_opt_pass pass_build_alias =
6505 gate_tree_pta, /* gate */
6509 0, /* static_pass_number */
6510 TV_NONE, /* tv_id */
6511 PROP_cfg | PROP_ssa, /* properties_required */
6512 0, /* properties_provided */
6513 0, /* properties_destroyed */
6514 0, /* todo_flags_start */
6515 TODO_rebuild_alias | TODO_dump_func /* todo_flags_finish */
6519 /* A dummy pass to cause points-to information to be computed via
6520 TODO_rebuild_alias. */
6522 struct gimple_opt_pass pass_build_ealias =
6526 "ealias", /* name */
6527 gate_tree_pta, /* gate */
6531 0, /* static_pass_number */
6532 TV_NONE, /* tv_id */
6533 PROP_cfg | PROP_ssa, /* properties_required */
6534 0, /* properties_provided */
6535 0, /* properties_destroyed */
6536 0, /* todo_flags_start */
6537 TODO_rebuild_alias | TODO_dump_func /* todo_flags_finish */
6542 /* Return true if we should execute IPA PTA. */
6548 /* Don't bother doing anything if the program has errors. */
6549 && !(errorcount || sorrycount));
6552 /* IPA PTA solutions for ESCAPED. */
6553 struct pt_solution ipa_escaped_pt
6554 = { true, false, false, false, false, false, false, NULL };
6556 /* Execute the driver for IPA PTA. */
6558 ipa_pta_execute (void)
6560 struct cgraph_node *node;
6561 struct varpool_node *var;
6566 init_alias_heapvars ();
6569 /* Build the constraints. */
6570 for (node = cgraph_nodes; node; node = node->next)
6572 struct cgraph_node *alias;
6575 /* Nodes without a body are not interesting. Especially do not
6576 visit clones at this point for now - we get duplicate decls
6577 there for inline clones at least. */
6578 if (!gimple_has_body_p (node->decl)
6582 vi = create_function_info_for (node->decl,
6583 alias_get_name (node->decl));
6585 /* Associate the varinfo node with all aliases. */
6586 for (alias = node->same_body; alias; alias = alias->next)
6587 insert_vi_for_tree (alias->decl, vi);
6590 /* Create constraints for global variables and their initializers. */
6591 for (var = varpool_nodes; var; var = var->next)
6593 struct varpool_node *alias;
6596 vi = get_vi_for_tree (var->decl);
6598 /* Associate the varinfo node with all aliases. */
6599 for (alias = var->extra_name; alias; alias = alias->next)
6600 insert_vi_for_tree (alias->decl, vi);
6606 "Generating constraints for global initializers\n\n");
6607 dump_constraints (dump_file, 0);
6608 fprintf (dump_file, "\n");
6610 from = VEC_length (constraint_t, constraints);
6612 for (node = cgraph_nodes; node; node = node->next)
6614 struct function *func;
6618 /* Nodes without a body are not interesting. */
6619 if (!gimple_has_body_p (node->decl)
6626 "Generating constraints for %s", cgraph_node_name (node));
6627 if (DECL_ASSEMBLER_NAME_SET_P (node->decl))
6628 fprintf (dump_file, " (%s)",
6629 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->decl)));
6630 fprintf (dump_file, "\n");
6633 func = DECL_STRUCT_FUNCTION (node->decl);
6634 old_func_decl = current_function_decl;
6636 current_function_decl = node->decl;
6638 /* For externally visible functions use local constraints for
6639 their arguments. For local functions we see all callers
6640 and thus do not need initial constraints for parameters. */
6641 if (node->local.externally_visible)
6642 intra_create_variable_infos ();
6644 /* Build constriants for the function body. */
6645 FOR_EACH_BB_FN (bb, func)
6647 gimple_stmt_iterator gsi;
6649 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
6652 gimple phi = gsi_stmt (gsi);
6654 if (is_gimple_reg (gimple_phi_result (phi)))
6655 find_func_aliases (phi);
6658 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6660 gimple stmt = gsi_stmt (gsi);
6662 find_func_aliases (stmt);
6663 find_func_clobbers (stmt);
6667 current_function_decl = old_func_decl;
6672 fprintf (dump_file, "\n");
6673 dump_constraints (dump_file, from);
6674 fprintf (dump_file, "\n");
6676 from = VEC_length (constraint_t, constraints);
6679 /* From the constraints compute the points-to sets. */
6680 solve_constraints ();
6682 /* Compute the global points-to sets for ESCAPED.
6683 ??? Note that the computed escape set is not correct
6684 for the whole unit as we fail to consider graph edges to
6685 externally visible functions. */
6686 find_what_var_points_to (get_varinfo (escaped_id), &ipa_escaped_pt);
6688 /* Make sure the ESCAPED solution (which is used as placeholder in
6689 other solutions) does not reference itself. This simplifies
6690 points-to solution queries. */
6691 ipa_escaped_pt.ipa_escaped = 0;
6693 /* Assign the points-to sets to the SSA names in the unit. */
6694 for (node = cgraph_nodes; node; node = node->next)
6697 struct function *fn;
6701 struct pt_solution uses, clobbers;
6702 struct cgraph_edge *e;
6704 /* Nodes without a body are not interesting. */
6705 if (!gimple_has_body_p (node->decl)
6709 fn = DECL_STRUCT_FUNCTION (node->decl);
6711 /* Compute the points-to sets for pointer SSA_NAMEs. */
6712 for (i = 0; VEC_iterate (tree, fn->gimple_df->ssa_names, i, ptr); ++i)
6715 && POINTER_TYPE_P (TREE_TYPE (ptr)))
6716 find_what_p_points_to (ptr);
6719 /* Compute the call-use and call-clobber sets for all direct calls. */
6720 fi = lookup_vi_for_tree (node->decl);
6721 gcc_assert (fi->is_fn_info);
6722 find_what_var_points_to (first_vi_for_offset (fi, fi_clobbers),
6724 find_what_var_points_to (first_vi_for_offset (fi, fi_uses), &uses);
6725 for (e = node->callers; e; e = e->next_caller)
6730 *gimple_call_clobber_set (e->call_stmt) = clobbers;
6731 *gimple_call_use_set (e->call_stmt) = uses;
6734 /* Compute the call-use and call-clobber sets for indirect calls
6735 and calls to external functions. */
6736 FOR_EACH_BB_FN (bb, fn)
6738 gimple_stmt_iterator gsi;
6740 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
6742 gimple stmt = gsi_stmt (gsi);
6743 struct pt_solution *pt;
6747 if (!is_gimple_call (stmt))
6750 /* Handle direct calls to external functions. */
6751 decl = gimple_call_fndecl (stmt);
6753 && (!(fi = lookup_vi_for_tree (decl))
6754 || !fi->is_fn_info))
6756 pt = gimple_call_use_set (stmt);
6757 if (gimple_call_flags (stmt) & ECF_CONST)
6758 memset (pt, 0, sizeof (struct pt_solution));
6759 else if ((vi = lookup_call_use_vi (stmt)) != NULL)
6761 find_what_var_points_to (vi, pt);
6762 /* Escaped (and thus nonlocal) variables are always
6763 implicitly used by calls. */
6764 /* ??? ESCAPED can be empty even though NONLOCAL
6767 pt->ipa_escaped = 1;
6771 /* If there is nothing special about this call then
6772 we have made everything that is used also escape. */
6773 *pt = ipa_escaped_pt;
6777 pt = gimple_call_clobber_set (stmt);
6778 if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
6779 memset (pt, 0, sizeof (struct pt_solution));
6780 else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
6782 find_what_var_points_to (vi, pt);
6783 /* Escaped (and thus nonlocal) variables are always
6784 implicitly clobbered by calls. */
6785 /* ??? ESCAPED can be empty even though NONLOCAL
6788 pt->ipa_escaped = 1;
6792 /* If there is nothing special about this call then
6793 we have made everything that is used also escape. */
6794 *pt = ipa_escaped_pt;
6799 /* Handle indirect calls. */
6801 && (fi = get_fi_for_callee (stmt)))
6803 /* We need to accumulate all clobbers/uses of all possible
6805 fi = get_varinfo (find (fi->id));
6806 /* If we cannot constrain the set of functions we'll end up
6807 calling we end up using/clobbering everything. */
6808 if (bitmap_bit_p (fi->solution, anything_id)
6809 || bitmap_bit_p (fi->solution, nonlocal_id)
6810 || bitmap_bit_p (fi->solution, escaped_id))
6812 pt_solution_reset (gimple_call_clobber_set (stmt));
6813 pt_solution_reset (gimple_call_use_set (stmt));
6819 struct pt_solution *uses, *clobbers;
6821 uses = gimple_call_use_set (stmt);
6822 clobbers = gimple_call_clobber_set (stmt);
6823 memset (uses, 0, sizeof (struct pt_solution));
6824 memset (clobbers, 0, sizeof (struct pt_solution));
6825 EXECUTE_IF_SET_IN_BITMAP (fi->solution, 0, i, bi)
6827 struct pt_solution sol;
6829 vi = get_varinfo (i);
6830 if (!vi->is_fn_info)
6832 /* ??? We could be more precise here? */
6834 uses->ipa_escaped = 1;
6835 clobbers->nonlocal = 1;
6836 clobbers->ipa_escaped = 1;
6840 if (!uses->anything)
6842 find_what_var_points_to
6843 (first_vi_for_offset (vi, fi_uses), &sol);
6844 pt_solution_ior_into (uses, &sol);
6846 if (!clobbers->anything)
6848 find_what_var_points_to
6849 (first_vi_for_offset (vi, fi_clobbers), &sol);
6850 pt_solution_ior_into (clobbers, &sol);
6858 fn->gimple_df->ipa_pta = true;
6861 delete_points_to_sets ();
6868 struct simple_ipa_opt_pass pass_ipa_pta =
6873 gate_ipa_pta, /* gate */
6874 ipa_pta_execute, /* execute */
6877 0, /* static_pass_number */
6878 TV_IPA_PTA, /* tv_id */
6879 0, /* properties_required */
6880 0, /* properties_provided */
6881 0, /* properties_destroyed */
6882 0, /* todo_flags_start */
6883 TODO_update_ssa /* todo_flags_finish */
6888 #include "gt-tree-ssa-structalias.h"