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"
30 #include "basic-block.h"
33 #include "tree-flow.h"
34 #include "tree-inline.h"
35 #include "diagnostic-core.h"
40 #include "tree-pass.h"
42 #include "alloc-pool.h"
43 #include "splay-tree.h"
47 #include "pointer-set.h"
49 /* The idea behind this analyzer is to generate set constraints from the
50 program, then solve the resulting constraints in order to generate the
53 Set constraints are a way of modeling program analysis problems that
54 involve sets. They consist of an inclusion constraint language,
55 describing the variables (each variable is a set) and operations that
56 are involved on the variables, and a set of rules that derive facts
57 from these operations. To solve a system of set constraints, you derive
58 all possible facts under the rules, which gives you the correct sets
61 See "Efficient Field-sensitive pointer analysis for C" by "David
62 J. Pearce and Paul H. J. Kelly and Chris Hankin, at
63 http://citeseer.ist.psu.edu/pearce04efficient.html
65 Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
66 of C Code in a Second" by ""Nevin Heintze and Olivier Tardieu" at
67 http://citeseer.ist.psu.edu/heintze01ultrafast.html
69 There are three types of real constraint expressions, DEREF,
70 ADDRESSOF, and SCALAR. Each constraint expression consists
71 of a constraint type, a variable, and an offset.
73 SCALAR is a constraint expression type used to represent x, whether
74 it appears on the LHS or the RHS of a statement.
75 DEREF is a constraint expression type used to represent *x, whether
76 it appears on the LHS or the RHS of a statement.
77 ADDRESSOF is a constraint expression used to represent &x, whether
78 it appears on the LHS or the RHS of a statement.
80 Each pointer variable in the program is assigned an integer id, and
81 each field of a structure variable is assigned an integer id as well.
83 Structure variables are linked to their list of fields through a "next
84 field" in each variable that points to the next field in offset
86 Each variable for a structure field has
88 1. "size", that tells the size in bits of that field.
89 2. "fullsize, that tells the size in bits of the entire structure.
90 3. "offset", that tells the offset in bits from the beginning of the
91 structure to this field.
103 foo.a -> id 1, size 32, offset 0, fullsize 64, next foo.b
104 foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
105 bar -> id 3, size 32, offset 0, fullsize 32, next NULL
108 In order to solve the system of set constraints, the following is
111 1. Each constraint variable x has a solution set associated with it,
114 2. Constraints are separated into direct, copy, and complex.
115 Direct constraints are ADDRESSOF constraints that require no extra
116 processing, such as P = &Q
117 Copy constraints are those of the form P = Q.
118 Complex constraints are all the constraints involving dereferences
119 and offsets (including offsetted copies).
121 3. All direct constraints of the form P = &Q are processed, such
122 that Q is added to Sol(P)
124 4. All complex constraints for a given constraint variable are stored in a
125 linked list attached to that variable's node.
127 5. A directed graph is built out of the copy constraints. Each
128 constraint variable is a node in the graph, and an edge from
129 Q to P is added for each copy constraint of the form P = Q
131 6. The graph is then walked, and solution sets are
132 propagated along the copy edges, such that an edge from Q to P
133 causes Sol(P) <- Sol(P) union Sol(Q).
135 7. As we visit each node, all complex constraints associated with
136 that node are processed by adding appropriate copy edges to the graph, or the
137 appropriate variables to the solution set.
139 8. The process of walking the graph is iterated until no solution
142 Prior to walking the graph in steps 6 and 7, We perform static
143 cycle elimination on the constraint graph, as well
144 as off-line variable substitution.
146 TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
147 on and turned into anything), but isn't. You can just see what offset
148 inside the pointed-to struct it's going to access.
150 TODO: Constant bounded arrays can be handled as if they were structs of the
151 same number of elements.
153 TODO: Modeling heap and incoming pointers becomes much better if we
154 add fields to them as we discover them, which we could do.
156 TODO: We could handle unions, but to be honest, it's probably not
157 worth the pain or slowdown. */
159 /* IPA-PTA optimizations possible.
161 When the indirect function called is ANYTHING we can add disambiguation
162 based on the function signatures (or simply the parameter count which
163 is the varinfo size). We also do not need to consider functions that
164 do not have their address taken.
166 The is_global_var bit which marks escape points is overly conservative
167 in IPA mode. Split it to is_escape_point and is_global_var - only
168 externally visible globals are escape points in IPA mode. This is
169 also needed to fix the pt_solution_includes_global predicate
170 (and thus ptr_deref_may_alias_global_p).
172 The way we introduce DECL_PT_UID to avoid fixing up all points-to
173 sets in the translation unit when we copy a DECL during inlining
174 pessimizes precision. The advantage is that the DECL_PT_UID keeps
175 compile-time and memory usage overhead low - the points-to sets
176 do not grow or get unshared as they would during a fixup phase.
177 An alternative solution is to delay IPA PTA until after all
178 inlining transformations have been applied.
180 The way we propagate clobber/use information isn't optimized.
181 It should use a new complex constraint that properly filters
182 out local variables of the callee (though that would make
183 the sets invalid after inlining). OTOH we might as well
184 admit defeat to WHOPR and simply do all the clobber/use analysis
185 and propagation after PTA finished but before we threw away
186 points-to information for memory variables. WHOPR and PTA
187 do not play along well anyway - the whole constraint solving
188 would need to be done in WPA phase and it will be very interesting
189 to apply the results to local SSA names during LTRANS phase.
191 We probably should compute a per-function unit-ESCAPE solution
192 propagating it simply like the clobber / uses solutions. The
193 solution can go alongside the non-IPA espaced solution and be
194 used to query which vars escape the unit through a function.
196 We never put function decls in points-to sets so we do not
197 keep the set of called functions for indirect calls.
199 And probably more. */
200 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct heapvar_map
)))
201 htab_t heapvar_for_stmt
;
203 static bool use_field_sensitive
= true;
204 static int in_ipa_mode
= 0;
206 /* Used for predecessor bitmaps. */
207 static bitmap_obstack predbitmap_obstack
;
209 /* Used for points-to sets. */
210 static bitmap_obstack pta_obstack
;
212 /* Used for oldsolution members of variables. */
213 static bitmap_obstack oldpta_obstack
;
215 /* Used for per-solver-iteration bitmaps. */
216 static bitmap_obstack iteration_obstack
;
218 static unsigned int create_variable_info_for (tree
, const char *);
219 typedef struct constraint_graph
*constraint_graph_t
;
220 static void unify_nodes (constraint_graph_t
, unsigned int, unsigned int, bool);
223 typedef struct constraint
*constraint_t
;
225 DEF_VEC_P(constraint_t
);
226 DEF_VEC_ALLOC_P(constraint_t
,heap
);
228 #define EXECUTE_IF_IN_NONNULL_BITMAP(a, b, c, d) \
230 EXECUTE_IF_SET_IN_BITMAP (a, b, c, d)
232 static struct constraint_stats
234 unsigned int total_vars
;
235 unsigned int nonpointer_vars
;
236 unsigned int unified_vars_static
;
237 unsigned int unified_vars_dynamic
;
238 unsigned int iterations
;
239 unsigned int num_edges
;
240 unsigned int num_implicit_edges
;
241 unsigned int points_to_sets_created
;
246 /* ID of this variable */
249 /* True if this is a variable created by the constraint analysis, such as
250 heap variables and constraints we had to break up. */
251 unsigned int is_artificial_var
: 1;
253 /* True if this is a special variable whose solution set should not be
255 unsigned int is_special_var
: 1;
257 /* True for variables whose size is not known or variable. */
258 unsigned int is_unknown_size_var
: 1;
260 /* True for (sub-)fields that represent a whole variable. */
261 unsigned int is_full_var
: 1;
263 /* True if this is a heap variable. */
264 unsigned int is_heap_var
: 1;
266 /* True if this is a variable tracking a restrict pointer source. */
267 unsigned int is_restrict_var
: 1;
269 /* True if this field may contain pointers. */
270 unsigned int may_have_pointers
: 1;
272 /* True if this field has only restrict qualified pointers. */
273 unsigned int only_restrict_pointers
: 1;
275 /* True if this represents a global variable. */
276 unsigned int is_global_var
: 1;
278 /* True if this represents a IPA function info. */
279 unsigned int is_fn_info
: 1;
281 /* A link to the variable for the next field in this structure. */
282 struct variable_info
*next
;
284 /* Offset of this variable, in bits, from the base variable */
285 unsigned HOST_WIDE_INT offset
;
287 /* Size of the variable, in bits. */
288 unsigned HOST_WIDE_INT size
;
290 /* Full size of the base variable, in bits. */
291 unsigned HOST_WIDE_INT fullsize
;
293 /* Name of this variable */
296 /* Tree that this variable is associated with. */
299 /* Points-to set for this variable. */
302 /* Old points-to set for this variable. */
305 typedef struct variable_info
*varinfo_t
;
307 static varinfo_t
first_vi_for_offset (varinfo_t
, unsigned HOST_WIDE_INT
);
308 static varinfo_t
first_or_preceding_vi_for_offset (varinfo_t
,
309 unsigned HOST_WIDE_INT
);
310 static varinfo_t
lookup_vi_for_tree (tree
);
312 /* Pool of variable info structures. */
313 static alloc_pool variable_info_pool
;
315 DEF_VEC_P(varinfo_t
);
317 DEF_VEC_ALLOC_P(varinfo_t
, heap
);
319 /* Table of variable info structures for constraint variables.
320 Indexed directly by variable info id. */
321 static VEC(varinfo_t
,heap
) *varmap
;
323 /* Return the varmap element N */
325 static inline varinfo_t
326 get_varinfo (unsigned int n
)
328 return VEC_index (varinfo_t
, varmap
, n
);
331 /* Static IDs for the special variables. */
332 enum { nothing_id
= 0, anything_id
= 1, readonly_id
= 2,
333 escaped_id
= 3, nonlocal_id
= 4,
334 storedanything_id
= 5, integer_id
= 6 };
336 struct GTY(()) heapvar_map
{
338 unsigned HOST_WIDE_INT offset
;
342 heapvar_map_eq (const void *p1
, const void *p2
)
344 const struct heapvar_map
*h1
= (const struct heapvar_map
*)p1
;
345 const struct heapvar_map
*h2
= (const struct heapvar_map
*)p2
;
346 return (h1
->map
.base
.from
== h2
->map
.base
.from
347 && h1
->offset
== h2
->offset
);
351 heapvar_map_hash (struct heapvar_map
*h
)
353 return iterative_hash_host_wide_int (h
->offset
,
354 htab_hash_pointer (h
->map
.base
.from
));
357 /* Lookup a heap var for FROM, and return it if we find one. */
360 heapvar_lookup (tree from
, unsigned HOST_WIDE_INT offset
)
362 struct heapvar_map
*h
, in
;
363 in
.map
.base
.from
= from
;
365 h
= (struct heapvar_map
*) htab_find_with_hash (heapvar_for_stmt
, &in
,
366 heapvar_map_hash (&in
));
372 /* Insert a mapping FROM->TO in the heap var for statement
376 heapvar_insert (tree from
, unsigned HOST_WIDE_INT offset
, tree to
)
378 struct heapvar_map
*h
;
381 h
= ggc_alloc_heapvar_map ();
382 h
->map
.base
.from
= from
;
384 h
->map
.hash
= heapvar_map_hash (h
);
386 loc
= htab_find_slot_with_hash (heapvar_for_stmt
, h
, h
->map
.hash
, INSERT
);
387 gcc_assert (*loc
== NULL
);
388 *(struct heapvar_map
**) loc
= h
;
391 /* Return a new variable info structure consisting for a variable
392 named NAME, and using constraint graph node NODE. Append it
393 to the vector of variable info structures. */
396 new_var_info (tree t
, const char *name
)
398 unsigned index
= VEC_length (varinfo_t
, varmap
);
399 varinfo_t ret
= (varinfo_t
) pool_alloc (variable_info_pool
);
404 /* Vars without decl are artificial and do not have sub-variables. */
405 ret
->is_artificial_var
= (t
== NULL_TREE
);
406 ret
->is_special_var
= false;
407 ret
->is_unknown_size_var
= false;
408 ret
->is_full_var
= (t
== NULL_TREE
);
409 ret
->is_heap_var
= false;
410 ret
->is_restrict_var
= false;
411 ret
->may_have_pointers
= true;
412 ret
->only_restrict_pointers
= false;
413 ret
->is_global_var
= (t
== NULL_TREE
);
414 ret
->is_fn_info
= false;
416 ret
->is_global_var
= is_global_var (t
);
417 ret
->solution
= BITMAP_ALLOC (&pta_obstack
);
418 ret
->oldsolution
= BITMAP_ALLOC (&oldpta_obstack
);
423 VEC_safe_push (varinfo_t
, heap
, varmap
, ret
);
429 /* A map mapping call statements to per-stmt variables for uses
430 and clobbers specific to the call. */
431 struct pointer_map_t
*call_stmt_vars
;
433 /* Lookup or create the variable for the call statement CALL. */
436 get_call_vi (gimple call
)
441 slot_p
= pointer_map_insert (call_stmt_vars
, call
);
443 return (varinfo_t
) *slot_p
;
445 vi
= new_var_info (NULL_TREE
, "CALLUSED");
449 vi
->is_full_var
= true;
451 vi
->next
= vi2
= new_var_info (NULL_TREE
, "CALLCLOBBERED");
455 vi2
->is_full_var
= true;
457 *slot_p
= (void *) vi
;
461 /* Lookup the variable for the call statement CALL representing
462 the uses. Returns NULL if there is nothing special about this call. */
465 lookup_call_use_vi (gimple call
)
469 slot_p
= pointer_map_contains (call_stmt_vars
, call
);
471 return (varinfo_t
) *slot_p
;
476 /* Lookup the variable for the call statement CALL representing
477 the clobbers. Returns NULL if there is nothing special about this call. */
480 lookup_call_clobber_vi (gimple call
)
482 varinfo_t uses
= lookup_call_use_vi (call
);
489 /* Lookup or create the variable for the call statement CALL representing
493 get_call_use_vi (gimple call
)
495 return get_call_vi (call
);
498 /* Lookup or create the variable for the call statement CALL representing
501 static varinfo_t ATTRIBUTE_UNUSED
502 get_call_clobber_vi (gimple call
)
504 return get_call_vi (call
)->next
;
508 typedef enum {SCALAR
, DEREF
, ADDRESSOF
} constraint_expr_type
;
510 /* An expression that appears in a constraint. */
512 struct constraint_expr
514 /* Constraint type. */
515 constraint_expr_type type
;
517 /* Variable we are referring to in the constraint. */
520 /* Offset, in bits, of this constraint from the beginning of
521 variables it ends up referring to.
523 IOW, in a deref constraint, we would deref, get the result set,
524 then add OFFSET to each member. */
525 HOST_WIDE_INT offset
;
528 /* Use 0x8000... as special unknown offset. */
529 #define UNKNOWN_OFFSET ((HOST_WIDE_INT)-1 << (HOST_BITS_PER_WIDE_INT-1))
531 typedef struct constraint_expr ce_s
;
533 DEF_VEC_ALLOC_O(ce_s
, heap
);
534 static void get_constraint_for_1 (tree
, VEC(ce_s
, heap
) **, bool, bool);
535 static void get_constraint_for (tree
, VEC(ce_s
, heap
) **);
536 static void get_constraint_for_rhs (tree
, VEC(ce_s
, heap
) **);
537 static void do_deref (VEC (ce_s
, heap
) **);
539 /* Our set constraints are made up of two constraint expressions, one
542 As described in the introduction, our set constraints each represent an
543 operation between set valued variables.
547 struct constraint_expr lhs
;
548 struct constraint_expr rhs
;
551 /* List of constraints that we use to build the constraint graph from. */
553 static VEC(constraint_t
,heap
) *constraints
;
554 static alloc_pool constraint_pool
;
556 /* The constraint graph is represented as an array of bitmaps
557 containing successor nodes. */
559 struct constraint_graph
561 /* Size of this graph, which may be different than the number of
562 nodes in the variable map. */
565 /* Explicit successors of each node. */
568 /* Implicit predecessors of each node (Used for variable
570 bitmap
*implicit_preds
;
572 /* Explicit predecessors of each node (Used for variable substitution). */
575 /* Indirect cycle representatives, or -1 if the node has no indirect
577 int *indirect_cycles
;
579 /* Representative node for a node. rep[a] == a unless the node has
583 /* Equivalence class representative for a label. This is used for
584 variable substitution. */
587 /* Pointer equivalence label for a node. All nodes with the same
588 pointer equivalence label can be unified together at some point
589 (either during constraint optimization or after the constraint
593 /* Pointer equivalence representative for a label. This is used to
594 handle nodes that are pointer equivalent but not location
595 equivalent. We can unite these once the addressof constraints
596 are transformed into initial points-to sets. */
599 /* Pointer equivalence label for each node, used during variable
601 unsigned int *pointer_label
;
603 /* Location equivalence label for each node, used during location
604 equivalence finding. */
605 unsigned int *loc_label
;
607 /* Pointed-by set for each node, used during location equivalence
608 finding. This is pointed-by rather than pointed-to, because it
609 is constructed using the predecessor graph. */
612 /* Points to sets for pointer equivalence. This is *not* the actual
613 points-to sets for nodes. */
616 /* Bitmap of nodes where the bit is set if the node is a direct
617 node. Used for variable substitution. */
618 sbitmap direct_nodes
;
620 /* Bitmap of nodes where the bit is set if the node is address
621 taken. Used for variable substitution. */
622 bitmap address_taken
;
624 /* Vector of complex constraints for each graph node. Complex
625 constraints are those involving dereferences or offsets that are
627 VEC(constraint_t
,heap
) **complex;
630 static constraint_graph_t graph
;
632 /* During variable substitution and the offline version of indirect
633 cycle finding, we create nodes to represent dereferences and
634 address taken constraints. These represent where these start and
636 #define FIRST_REF_NODE (VEC_length (varinfo_t, varmap))
637 #define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
639 /* Return the representative node for NODE, if NODE has been unioned
641 This function performs path compression along the way to finding
642 the representative. */
645 find (unsigned int node
)
647 gcc_assert (node
< graph
->size
);
648 if (graph
->rep
[node
] != node
)
649 return graph
->rep
[node
] = find (graph
->rep
[node
]);
653 /* Union the TO and FROM nodes to the TO nodes.
654 Note that at some point in the future, we may want to do
655 union-by-rank, in which case we are going to have to return the
656 node we unified to. */
659 unite (unsigned int to
, unsigned int from
)
661 gcc_assert (to
< graph
->size
&& from
< graph
->size
);
662 if (to
!= from
&& graph
->rep
[from
] != to
)
664 graph
->rep
[from
] = to
;
670 /* Create a new constraint consisting of LHS and RHS expressions. */
673 new_constraint (const struct constraint_expr lhs
,
674 const struct constraint_expr rhs
)
676 constraint_t ret
= (constraint_t
) pool_alloc (constraint_pool
);
682 /* Print out constraint C to FILE. */
685 dump_constraint (FILE *file
, constraint_t c
)
687 if (c
->lhs
.type
== ADDRESSOF
)
689 else if (c
->lhs
.type
== DEREF
)
691 fprintf (file
, "%s", get_varinfo (c
->lhs
.var
)->name
);
692 if (c
->lhs
.offset
== UNKNOWN_OFFSET
)
693 fprintf (file
, " + UNKNOWN");
694 else if (c
->lhs
.offset
!= 0)
695 fprintf (file
, " + " HOST_WIDE_INT_PRINT_DEC
, c
->lhs
.offset
);
696 fprintf (file
, " = ");
697 if (c
->rhs
.type
== ADDRESSOF
)
699 else if (c
->rhs
.type
== DEREF
)
701 fprintf (file
, "%s", get_varinfo (c
->rhs
.var
)->name
);
702 if (c
->rhs
.offset
== UNKNOWN_OFFSET
)
703 fprintf (file
, " + UNKNOWN");
704 else if (c
->rhs
.offset
!= 0)
705 fprintf (file
, " + " HOST_WIDE_INT_PRINT_DEC
, c
->rhs
.offset
);
706 fprintf (file
, "\n");
710 void debug_constraint (constraint_t
);
711 void debug_constraints (void);
712 void debug_constraint_graph (void);
713 void debug_solution_for_var (unsigned int);
714 void debug_sa_points_to_info (void);
716 /* Print out constraint C to stderr. */
719 debug_constraint (constraint_t c
)
721 dump_constraint (stderr
, c
);
724 /* Print out all constraints to FILE */
727 dump_constraints (FILE *file
, int from
)
731 for (i
= from
; VEC_iterate (constraint_t
, constraints
, i
, c
); i
++)
732 dump_constraint (file
, c
);
735 /* Print out all constraints to stderr. */
738 debug_constraints (void)
740 dump_constraints (stderr
, 0);
743 /* Print out to FILE the edge in the constraint graph that is created by
744 constraint c. The edge may have a label, depending on the type of
745 constraint that it represents. If complex1, e.g: a = *b, then the label
746 is "=*", if complex2, e.g: *a = b, then the label is "*=", if
747 complex with an offset, e.g: a = b + 8, then the label is "+".
748 Otherwise the edge has no label. */
751 dump_constraint_edge (FILE *file
, constraint_t c
)
753 if (c
->rhs
.type
!= ADDRESSOF
)
755 const char *src
= get_varinfo (c
->rhs
.var
)->name
;
756 const char *dst
= get_varinfo (c
->lhs
.var
)->name
;
757 fprintf (file
, " \"%s\" -> \"%s\" ", src
, dst
);
758 /* Due to preprocessing of constraints, instructions like *a = *b are
759 illegal; thus, we do not have to handle such cases. */
760 if (c
->lhs
.type
== DEREF
)
761 fprintf (file
, " [ label=\"*=\" ] ;\n");
762 else if (c
->rhs
.type
== DEREF
)
763 fprintf (file
, " [ label=\"=*\" ] ;\n");
766 /* We must check the case where the constraint is an offset.
767 In this case, it is treated as a complex constraint. */
768 if (c
->rhs
.offset
!= c
->lhs
.offset
)
769 fprintf (file
, " [ label=\"+\" ] ;\n");
771 fprintf (file
, " ;\n");
776 /* Print the constraint graph in dot format. */
779 dump_constraint_graph (FILE *file
)
781 unsigned int i
=0, size
;
784 /* Only print the graph if it has already been initialized: */
788 /* Print the constraints used to produce the constraint graph. The
789 constraints will be printed as comments in the dot file: */
790 fprintf (file
, "\n\n/* Constraints used in the constraint graph:\n");
791 dump_constraints (file
, 0);
792 fprintf (file
, "*/\n");
794 /* Prints the header of the dot file: */
795 fprintf (file
, "\n\n// The constraint graph in dot format:\n");
796 fprintf (file
, "strict digraph {\n");
797 fprintf (file
, " node [\n shape = box\n ]\n");
798 fprintf (file
, " edge [\n fontsize = \"12\"\n ]\n");
799 fprintf (file
, "\n // List of nodes in the constraint graph:\n");
801 /* The next lines print the nodes in the graph. In order to get the
802 number of nodes in the graph, we must choose the minimum between the
803 vector VEC (varinfo_t, varmap) and graph->size. If the graph has not
804 yet been initialized, then graph->size == 0, otherwise we must only
805 read nodes that have an entry in VEC (varinfo_t, varmap). */
806 size
= VEC_length (varinfo_t
, varmap
);
807 size
= size
< graph
->size
? size
: graph
->size
;
808 for (i
= 0; i
< size
; i
++)
810 const char *name
= get_varinfo (graph
->rep
[i
])->name
;
811 fprintf (file
, " \"%s\" ;\n", name
);
814 /* Go over the list of constraints printing the edges in the constraint
816 fprintf (file
, "\n // The constraint edges:\n");
817 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
819 dump_constraint_edge (file
, c
);
821 /* Prints the tail of the dot file. By now, only the closing bracket. */
822 fprintf (file
, "}\n\n\n");
825 /* Print out the constraint graph to stderr. */
828 debug_constraint_graph (void)
830 dump_constraint_graph (stderr
);
835 The solver is a simple worklist solver, that works on the following
838 sbitmap changed_nodes = all zeroes;
840 For each node that is not already collapsed:
842 set bit in changed nodes
844 while (changed_count > 0)
846 compute topological ordering for constraint graph
848 find and collapse cycles in the constraint graph (updating
849 changed if necessary)
851 for each node (n) in the graph in topological order:
854 Process each complex constraint associated with the node,
855 updating changed if necessary.
857 For each outgoing edge from n, propagate the solution from n to
858 the destination of the edge, updating changed as necessary.
862 /* Return true if two constraint expressions A and B are equal. */
865 constraint_expr_equal (struct constraint_expr a
, struct constraint_expr b
)
867 return a
.type
== b
.type
&& a
.var
== b
.var
&& a
.offset
== b
.offset
;
870 /* Return true if constraint expression A is less than constraint expression
871 B. This is just arbitrary, but consistent, in order to give them an
875 constraint_expr_less (struct constraint_expr a
, struct constraint_expr b
)
877 if (a
.type
== b
.type
)
880 return a
.offset
< b
.offset
;
882 return a
.var
< b
.var
;
885 return a
.type
< b
.type
;
888 /* Return true if constraint A is less than constraint B. This is just
889 arbitrary, but consistent, in order to give them an ordering. */
892 constraint_less (const constraint_t a
, const constraint_t b
)
894 if (constraint_expr_less (a
->lhs
, b
->lhs
))
896 else if (constraint_expr_less (b
->lhs
, a
->lhs
))
899 return constraint_expr_less (a
->rhs
, b
->rhs
);
902 /* Return true if two constraints A and B are equal. */
905 constraint_equal (struct constraint a
, struct constraint b
)
907 return constraint_expr_equal (a
.lhs
, b
.lhs
)
908 && constraint_expr_equal (a
.rhs
, b
.rhs
);
912 /* Find a constraint LOOKFOR in the sorted constraint vector VEC */
915 constraint_vec_find (VEC(constraint_t
,heap
) *vec
,
916 struct constraint lookfor
)
924 place
= VEC_lower_bound (constraint_t
, vec
, &lookfor
, constraint_less
);
925 if (place
>= VEC_length (constraint_t
, vec
))
927 found
= VEC_index (constraint_t
, vec
, place
);
928 if (!constraint_equal (*found
, lookfor
))
933 /* Union two constraint vectors, TO and FROM. Put the result in TO. */
936 constraint_set_union (VEC(constraint_t
,heap
) **to
,
937 VEC(constraint_t
,heap
) **from
)
942 FOR_EACH_VEC_ELT (constraint_t
, *from
, i
, c
)
944 if (constraint_vec_find (*to
, *c
) == NULL
)
946 unsigned int place
= VEC_lower_bound (constraint_t
, *to
, c
,
948 VEC_safe_insert (constraint_t
, heap
, *to
, place
, c
);
953 /* Expands the solution in SET to all sub-fields of variables included.
954 Union the expanded result into RESULT. */
957 solution_set_expand (bitmap result
, bitmap set
)
963 /* In a first pass record all variables we need to add all
964 sub-fields off. This avoids quadratic behavior. */
965 EXECUTE_IF_SET_IN_BITMAP (set
, 0, j
, bi
)
967 varinfo_t v
= get_varinfo (j
);
968 if (v
->is_artificial_var
971 v
= lookup_vi_for_tree (v
->decl
);
973 vars
= BITMAP_ALLOC (NULL
);
974 bitmap_set_bit (vars
, v
->id
);
977 /* In the second pass now do the addition to the solution and
978 to speed up solving add it to the delta as well. */
981 EXECUTE_IF_SET_IN_BITMAP (vars
, 0, j
, bi
)
983 varinfo_t v
= get_varinfo (j
);
984 for (; v
!= NULL
; v
= v
->next
)
985 bitmap_set_bit (result
, v
->id
);
991 /* Take a solution set SET, add OFFSET to each member of the set, and
992 overwrite SET with the result when done. */
995 solution_set_add (bitmap set
, HOST_WIDE_INT offset
)
997 bitmap result
= BITMAP_ALLOC (&iteration_obstack
);
1001 /* If the offset is unknown we have to expand the solution to
1003 if (offset
== UNKNOWN_OFFSET
)
1005 solution_set_expand (set
, set
);
1009 EXECUTE_IF_SET_IN_BITMAP (set
, 0, i
, bi
)
1011 varinfo_t vi
= get_varinfo (i
);
1013 /* If this is a variable with just one field just set its bit
1015 if (vi
->is_artificial_var
1016 || vi
->is_unknown_size_var
1018 bitmap_set_bit (result
, i
);
1021 unsigned HOST_WIDE_INT fieldoffset
= vi
->offset
+ offset
;
1023 /* If the offset makes the pointer point to before the
1024 variable use offset zero for the field lookup. */
1026 && fieldoffset
> vi
->offset
)
1030 vi
= first_or_preceding_vi_for_offset (vi
, fieldoffset
);
1032 bitmap_set_bit (result
, vi
->id
);
1033 /* If the result is not exactly at fieldoffset include the next
1034 field as well. See get_constraint_for_ptr_offset for more
1036 if (vi
->offset
!= fieldoffset
1037 && vi
->next
!= NULL
)
1038 bitmap_set_bit (result
, vi
->next
->id
);
1042 bitmap_copy (set
, result
);
1043 BITMAP_FREE (result
);
1046 /* Union solution sets TO and FROM, and add INC to each member of FROM in the
1050 set_union_with_increment (bitmap to
, bitmap from
, HOST_WIDE_INT inc
)
1053 return bitmap_ior_into (to
, from
);
1059 tmp
= BITMAP_ALLOC (&iteration_obstack
);
1060 bitmap_copy (tmp
, from
);
1061 solution_set_add (tmp
, inc
);
1062 res
= bitmap_ior_into (to
, tmp
);
1068 /* Insert constraint C into the list of complex constraints for graph
1072 insert_into_complex (constraint_graph_t graph
,
1073 unsigned int var
, constraint_t c
)
1075 VEC (constraint_t
, heap
) *complex = graph
->complex[var
];
1076 unsigned int place
= VEC_lower_bound (constraint_t
, complex, c
,
1079 /* Only insert constraints that do not already exist. */
1080 if (place
>= VEC_length (constraint_t
, complex)
1081 || !constraint_equal (*c
, *VEC_index (constraint_t
, complex, place
)))
1082 VEC_safe_insert (constraint_t
, heap
, graph
->complex[var
], place
, c
);
1086 /* Condense two variable nodes into a single variable node, by moving
1087 all associated info from SRC to TO. */
1090 merge_node_constraints (constraint_graph_t graph
, unsigned int to
,
1096 gcc_assert (find (from
) == to
);
1098 /* Move all complex constraints from src node into to node */
1099 FOR_EACH_VEC_ELT (constraint_t
, graph
->complex[from
], i
, c
)
1101 /* In complex constraints for node src, we may have either
1102 a = *src, and *src = a, or an offseted constraint which are
1103 always added to the rhs node's constraints. */
1105 if (c
->rhs
.type
== DEREF
)
1107 else if (c
->lhs
.type
== DEREF
)
1112 constraint_set_union (&graph
->complex[to
], &graph
->complex[from
]);
1113 VEC_free (constraint_t
, heap
, graph
->complex[from
]);
1114 graph
->complex[from
] = NULL
;
1118 /* Remove edges involving NODE from GRAPH. */
1121 clear_edges_for_node (constraint_graph_t graph
, unsigned int node
)
1123 if (graph
->succs
[node
])
1124 BITMAP_FREE (graph
->succs
[node
]);
1127 /* Merge GRAPH nodes FROM and TO into node TO. */
1130 merge_graph_nodes (constraint_graph_t graph
, unsigned int to
,
1133 if (graph
->indirect_cycles
[from
] != -1)
1135 /* If we have indirect cycles with the from node, and we have
1136 none on the to node, the to node has indirect cycles from the
1137 from node now that they are unified.
1138 If indirect cycles exist on both, unify the nodes that they
1139 are in a cycle with, since we know they are in a cycle with
1141 if (graph
->indirect_cycles
[to
] == -1)
1142 graph
->indirect_cycles
[to
] = graph
->indirect_cycles
[from
];
1145 /* Merge all the successor edges. */
1146 if (graph
->succs
[from
])
1148 if (!graph
->succs
[to
])
1149 graph
->succs
[to
] = BITMAP_ALLOC (&pta_obstack
);
1150 bitmap_ior_into (graph
->succs
[to
],
1151 graph
->succs
[from
]);
1154 clear_edges_for_node (graph
, from
);
1158 /* Add an indirect graph edge to GRAPH, going from TO to FROM if
1159 it doesn't exist in the graph already. */
1162 add_implicit_graph_edge (constraint_graph_t graph
, unsigned int to
,
1168 if (!graph
->implicit_preds
[to
])
1169 graph
->implicit_preds
[to
] = BITMAP_ALLOC (&predbitmap_obstack
);
1171 if (bitmap_set_bit (graph
->implicit_preds
[to
], from
))
1172 stats
.num_implicit_edges
++;
1175 /* Add a predecessor graph edge to GRAPH, going from TO to FROM if
1176 it doesn't exist in the graph already.
1177 Return false if the edge already existed, true otherwise. */
1180 add_pred_graph_edge (constraint_graph_t graph
, unsigned int to
,
1183 if (!graph
->preds
[to
])
1184 graph
->preds
[to
] = BITMAP_ALLOC (&predbitmap_obstack
);
1185 bitmap_set_bit (graph
->preds
[to
], from
);
1188 /* Add a graph edge to GRAPH, going from FROM to TO if
1189 it doesn't exist in the graph already.
1190 Return false if the edge already existed, true otherwise. */
1193 add_graph_edge (constraint_graph_t graph
, unsigned int to
,
1204 if (!graph
->succs
[from
])
1205 graph
->succs
[from
] = BITMAP_ALLOC (&pta_obstack
);
1206 if (bitmap_set_bit (graph
->succs
[from
], to
))
1209 if (to
< FIRST_REF_NODE
&& from
< FIRST_REF_NODE
)
1217 /* Return true if {DEST.SRC} is an existing graph edge in GRAPH. */
1220 valid_graph_edge (constraint_graph_t graph
, unsigned int src
,
1223 return (graph
->succs
[dest
]
1224 && bitmap_bit_p (graph
->succs
[dest
], src
));
1227 /* Initialize the constraint graph structure to contain SIZE nodes. */
1230 init_graph (unsigned int size
)
1234 graph
= XCNEW (struct constraint_graph
);
1236 graph
->succs
= XCNEWVEC (bitmap
, graph
->size
);
1237 graph
->indirect_cycles
= XNEWVEC (int, graph
->size
);
1238 graph
->rep
= XNEWVEC (unsigned int, graph
->size
);
1239 graph
->complex = XCNEWVEC (VEC(constraint_t
, heap
) *, size
);
1240 graph
->pe
= XCNEWVEC (unsigned int, graph
->size
);
1241 graph
->pe_rep
= XNEWVEC (int, graph
->size
);
1243 for (j
= 0; j
< graph
->size
; j
++)
1246 graph
->pe_rep
[j
] = -1;
1247 graph
->indirect_cycles
[j
] = -1;
1251 /* Build the constraint graph, adding only predecessor edges right now. */
1254 build_pred_graph (void)
1260 graph
->implicit_preds
= XCNEWVEC (bitmap
, graph
->size
);
1261 graph
->preds
= XCNEWVEC (bitmap
, graph
->size
);
1262 graph
->pointer_label
= XCNEWVEC (unsigned int, graph
->size
);
1263 graph
->loc_label
= XCNEWVEC (unsigned int, graph
->size
);
1264 graph
->pointed_by
= XCNEWVEC (bitmap
, graph
->size
);
1265 graph
->points_to
= XCNEWVEC (bitmap
, graph
->size
);
1266 graph
->eq_rep
= XNEWVEC (int, graph
->size
);
1267 graph
->direct_nodes
= sbitmap_alloc (graph
->size
);
1268 graph
->address_taken
= BITMAP_ALLOC (&predbitmap_obstack
);
1269 sbitmap_zero (graph
->direct_nodes
);
1271 for (j
= 0; j
< FIRST_REF_NODE
; j
++)
1273 if (!get_varinfo (j
)->is_special_var
)
1274 SET_BIT (graph
->direct_nodes
, j
);
1277 for (j
= 0; j
< graph
->size
; j
++)
1278 graph
->eq_rep
[j
] = -1;
1280 for (j
= 0; j
< VEC_length (varinfo_t
, varmap
); j
++)
1281 graph
->indirect_cycles
[j
] = -1;
1283 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
1285 struct constraint_expr lhs
= c
->lhs
;
1286 struct constraint_expr rhs
= c
->rhs
;
1287 unsigned int lhsvar
= lhs
.var
;
1288 unsigned int rhsvar
= rhs
.var
;
1290 if (lhs
.type
== DEREF
)
1293 if (rhs
.offset
== 0 && lhs
.offset
== 0 && rhs
.type
== SCALAR
)
1294 add_pred_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1296 else if (rhs
.type
== DEREF
)
1299 if (rhs
.offset
== 0 && lhs
.offset
== 0 && lhs
.type
== SCALAR
)
1300 add_pred_graph_edge (graph
, lhsvar
, FIRST_REF_NODE
+ rhsvar
);
1302 RESET_BIT (graph
->direct_nodes
, lhsvar
);
1304 else if (rhs
.type
== ADDRESSOF
)
1309 if (graph
->points_to
[lhsvar
] == NULL
)
1310 graph
->points_to
[lhsvar
] = BITMAP_ALLOC (&predbitmap_obstack
);
1311 bitmap_set_bit (graph
->points_to
[lhsvar
], rhsvar
);
1313 if (graph
->pointed_by
[rhsvar
] == NULL
)
1314 graph
->pointed_by
[rhsvar
] = BITMAP_ALLOC (&predbitmap_obstack
);
1315 bitmap_set_bit (graph
->pointed_by
[rhsvar
], lhsvar
);
1317 /* Implicitly, *x = y */
1318 add_implicit_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1320 /* All related variables are no longer direct nodes. */
1321 RESET_BIT (graph
->direct_nodes
, rhsvar
);
1322 v
= get_varinfo (rhsvar
);
1323 if (!v
->is_full_var
)
1325 v
= lookup_vi_for_tree (v
->decl
);
1328 RESET_BIT (graph
->direct_nodes
, v
->id
);
1333 bitmap_set_bit (graph
->address_taken
, rhsvar
);
1335 else if (lhsvar
> anything_id
1336 && lhsvar
!= rhsvar
&& lhs
.offset
== 0 && rhs
.offset
== 0)
1339 add_pred_graph_edge (graph
, lhsvar
, rhsvar
);
1340 /* Implicitly, *x = *y */
1341 add_implicit_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
,
1342 FIRST_REF_NODE
+ rhsvar
);
1344 else if (lhs
.offset
!= 0 || rhs
.offset
!= 0)
1346 if (rhs
.offset
!= 0)
1347 RESET_BIT (graph
->direct_nodes
, lhs
.var
);
1348 else if (lhs
.offset
!= 0)
1349 RESET_BIT (graph
->direct_nodes
, rhs
.var
);
1354 /* Build the constraint graph, adding successor edges. */
1357 build_succ_graph (void)
1362 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
1364 struct constraint_expr lhs
;
1365 struct constraint_expr rhs
;
1366 unsigned int lhsvar
;
1367 unsigned int rhsvar
;
1374 lhsvar
= find (lhs
.var
);
1375 rhsvar
= find (rhs
.var
);
1377 if (lhs
.type
== DEREF
)
1379 if (rhs
.offset
== 0 && lhs
.offset
== 0 && rhs
.type
== SCALAR
)
1380 add_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1382 else if (rhs
.type
== DEREF
)
1384 if (rhs
.offset
== 0 && lhs
.offset
== 0 && lhs
.type
== SCALAR
)
1385 add_graph_edge (graph
, lhsvar
, FIRST_REF_NODE
+ rhsvar
);
1387 else if (rhs
.type
== ADDRESSOF
)
1390 gcc_assert (find (rhs
.var
) == rhs
.var
);
1391 bitmap_set_bit (get_varinfo (lhsvar
)->solution
, rhsvar
);
1393 else if (lhsvar
> anything_id
1394 && lhsvar
!= rhsvar
&& lhs
.offset
== 0 && rhs
.offset
== 0)
1396 add_graph_edge (graph
, lhsvar
, rhsvar
);
1400 /* Add edges from STOREDANYTHING to all non-direct nodes that can
1401 receive pointers. */
1402 t
= find (storedanything_id
);
1403 for (i
= integer_id
+ 1; i
< FIRST_REF_NODE
; ++i
)
1405 if (!TEST_BIT (graph
->direct_nodes
, i
)
1406 && get_varinfo (i
)->may_have_pointers
)
1407 add_graph_edge (graph
, find (i
), t
);
1410 /* Everything stored to ANYTHING also potentially escapes. */
1411 add_graph_edge (graph
, find (escaped_id
), t
);
1415 /* Changed variables on the last iteration. */
1416 static unsigned int changed_count
;
1417 static sbitmap changed
;
1419 /* Strongly Connected Component visitation info. */
1426 unsigned int *node_mapping
;
1428 VEC(unsigned,heap
) *scc_stack
;
1432 /* Recursive routine to find strongly connected components in GRAPH.
1433 SI is the SCC info to store the information in, and N is the id of current
1434 graph node we are processing.
1436 This is Tarjan's strongly connected component finding algorithm, as
1437 modified by Nuutila to keep only non-root nodes on the stack.
1438 The algorithm can be found in "On finding the strongly connected
1439 connected components in a directed graph" by Esko Nuutila and Eljas
1440 Soisalon-Soininen, in Information Processing Letters volume 49,
1441 number 1, pages 9-14. */
1444 scc_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
1448 unsigned int my_dfs
;
1450 SET_BIT (si
->visited
, n
);
1451 si
->dfs
[n
] = si
->current_index
++;
1452 my_dfs
= si
->dfs
[n
];
1454 /* Visit all the successors. */
1455 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[n
], 0, i
, bi
)
1459 if (i
> LAST_REF_NODE
)
1463 if (TEST_BIT (si
->deleted
, w
))
1466 if (!TEST_BIT (si
->visited
, w
))
1467 scc_visit (graph
, si
, w
);
1469 unsigned int t
= find (w
);
1470 unsigned int nnode
= find (n
);
1471 gcc_assert (nnode
== n
);
1473 if (si
->dfs
[t
] < si
->dfs
[nnode
])
1474 si
->dfs
[n
] = si
->dfs
[t
];
1478 /* See if any components have been identified. */
1479 if (si
->dfs
[n
] == my_dfs
)
1481 if (VEC_length (unsigned, si
->scc_stack
) > 0
1482 && si
->dfs
[VEC_last (unsigned, si
->scc_stack
)] >= my_dfs
)
1484 bitmap scc
= BITMAP_ALLOC (NULL
);
1485 unsigned int lowest_node
;
1488 bitmap_set_bit (scc
, n
);
1490 while (VEC_length (unsigned, si
->scc_stack
) != 0
1491 && si
->dfs
[VEC_last (unsigned, si
->scc_stack
)] >= my_dfs
)
1493 unsigned int w
= VEC_pop (unsigned, si
->scc_stack
);
1495 bitmap_set_bit (scc
, w
);
1498 lowest_node
= bitmap_first_set_bit (scc
);
1499 gcc_assert (lowest_node
< FIRST_REF_NODE
);
1501 /* Collapse the SCC nodes into a single node, and mark the
1503 EXECUTE_IF_SET_IN_BITMAP (scc
, 0, i
, bi
)
1505 if (i
< FIRST_REF_NODE
)
1507 if (unite (lowest_node
, i
))
1508 unify_nodes (graph
, lowest_node
, i
, false);
1512 unite (lowest_node
, i
);
1513 graph
->indirect_cycles
[i
- FIRST_REF_NODE
] = lowest_node
;
1517 SET_BIT (si
->deleted
, n
);
1520 VEC_safe_push (unsigned, heap
, si
->scc_stack
, n
);
1523 /* Unify node FROM into node TO, updating the changed count if
1524 necessary when UPDATE_CHANGED is true. */
1527 unify_nodes (constraint_graph_t graph
, unsigned int to
, unsigned int from
,
1528 bool update_changed
)
1531 gcc_assert (to
!= from
&& find (to
) == to
);
1532 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1533 fprintf (dump_file
, "Unifying %s to %s\n",
1534 get_varinfo (from
)->name
,
1535 get_varinfo (to
)->name
);
1538 stats
.unified_vars_dynamic
++;
1540 stats
.unified_vars_static
++;
1542 merge_graph_nodes (graph
, to
, from
);
1543 merge_node_constraints (graph
, to
, from
);
1545 /* Mark TO as changed if FROM was changed. If TO was already marked
1546 as changed, decrease the changed count. */
1548 if (update_changed
&& TEST_BIT (changed
, from
))
1550 RESET_BIT (changed
, from
);
1551 if (!TEST_BIT (changed
, to
))
1552 SET_BIT (changed
, to
);
1555 gcc_assert (changed_count
> 0);
1559 if (get_varinfo (from
)->solution
)
1561 /* If the solution changes because of the merging, we need to mark
1562 the variable as changed. */
1563 if (bitmap_ior_into (get_varinfo (to
)->solution
,
1564 get_varinfo (from
)->solution
))
1566 if (update_changed
&& !TEST_BIT (changed
, to
))
1568 SET_BIT (changed
, to
);
1573 BITMAP_FREE (get_varinfo (from
)->solution
);
1574 BITMAP_FREE (get_varinfo (from
)->oldsolution
);
1576 if (stats
.iterations
> 0)
1578 BITMAP_FREE (get_varinfo (to
)->oldsolution
);
1579 get_varinfo (to
)->oldsolution
= BITMAP_ALLOC (&oldpta_obstack
);
1582 if (valid_graph_edge (graph
, to
, to
))
1584 if (graph
->succs
[to
])
1585 bitmap_clear_bit (graph
->succs
[to
], to
);
1589 /* Information needed to compute the topological ordering of a graph. */
1593 /* sbitmap of visited nodes. */
1595 /* Array that stores the topological order of the graph, *in
1597 VEC(unsigned,heap
) *topo_order
;
1601 /* Initialize and return a topological info structure. */
1603 static struct topo_info
*
1604 init_topo_info (void)
1606 size_t size
= graph
->size
;
1607 struct topo_info
*ti
= XNEW (struct topo_info
);
1608 ti
->visited
= sbitmap_alloc (size
);
1609 sbitmap_zero (ti
->visited
);
1610 ti
->topo_order
= VEC_alloc (unsigned, heap
, 1);
1615 /* Free the topological sort info pointed to by TI. */
1618 free_topo_info (struct topo_info
*ti
)
1620 sbitmap_free (ti
->visited
);
1621 VEC_free (unsigned, heap
, ti
->topo_order
);
1625 /* Visit the graph in topological order, and store the order in the
1626 topo_info structure. */
1629 topo_visit (constraint_graph_t graph
, struct topo_info
*ti
,
1635 SET_BIT (ti
->visited
, n
);
1637 if (graph
->succs
[n
])
1638 EXECUTE_IF_SET_IN_BITMAP (graph
->succs
[n
], 0, j
, bi
)
1640 if (!TEST_BIT (ti
->visited
, j
))
1641 topo_visit (graph
, ti
, j
);
1644 VEC_safe_push (unsigned, heap
, ti
->topo_order
, n
);
1647 /* Process a constraint C that represents x = *(y + off), using DELTA as the
1648 starting solution for y. */
1651 do_sd_constraint (constraint_graph_t graph
, constraint_t c
,
1654 unsigned int lhs
= c
->lhs
.var
;
1656 bitmap sol
= get_varinfo (lhs
)->solution
;
1659 HOST_WIDE_INT roffset
= c
->rhs
.offset
;
1661 /* Our IL does not allow this. */
1662 gcc_assert (c
->lhs
.offset
== 0);
1664 /* If the solution of Y contains anything it is good enough to transfer
1666 if (bitmap_bit_p (delta
, anything_id
))
1668 flag
|= bitmap_set_bit (sol
, anything_id
);
1672 /* If we do not know at with offset the rhs is dereferenced compute
1673 the reachability set of DELTA, conservatively assuming it is
1674 dereferenced at all valid offsets. */
1675 if (roffset
== UNKNOWN_OFFSET
)
1677 solution_set_expand (delta
, delta
);
1678 /* No further offset processing is necessary. */
1682 /* For each variable j in delta (Sol(y)), add
1683 an edge in the graph from j to x, and union Sol(j) into Sol(x). */
1684 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, j
, bi
)
1686 varinfo_t v
= get_varinfo (j
);
1687 HOST_WIDE_INT fieldoffset
= v
->offset
+ roffset
;
1691 fieldoffset
= v
->offset
;
1692 else if (roffset
!= 0)
1693 v
= first_vi_for_offset (v
, fieldoffset
);
1694 /* If the access is outside of the variable we can ignore it. */
1702 /* Adding edges from the special vars is pointless.
1703 They don't have sets that can change. */
1704 if (get_varinfo (t
)->is_special_var
)
1705 flag
|= bitmap_ior_into (sol
, get_varinfo (t
)->solution
);
1706 /* Merging the solution from ESCAPED needlessly increases
1707 the set. Use ESCAPED as representative instead. */
1708 else if (v
->id
== escaped_id
)
1709 flag
|= bitmap_set_bit (sol
, escaped_id
);
1710 else if (v
->may_have_pointers
1711 && add_graph_edge (graph
, lhs
, t
))
1712 flag
|= bitmap_ior_into (sol
, get_varinfo (t
)->solution
);
1714 /* If the variable is not exactly at the requested offset
1715 we have to include the next one. */
1716 if (v
->offset
== (unsigned HOST_WIDE_INT
)fieldoffset
1721 fieldoffset
= v
->offset
;
1727 /* If the LHS solution changed, mark the var as changed. */
1730 get_varinfo (lhs
)->solution
= sol
;
1731 if (!TEST_BIT (changed
, lhs
))
1733 SET_BIT (changed
, lhs
);
1739 /* Process a constraint C that represents *(x + off) = y using DELTA
1740 as the starting solution for x. */
1743 do_ds_constraint (constraint_t c
, bitmap delta
)
1745 unsigned int rhs
= c
->rhs
.var
;
1746 bitmap sol
= get_varinfo (rhs
)->solution
;
1749 HOST_WIDE_INT loff
= c
->lhs
.offset
;
1750 bool escaped_p
= false;
1752 /* Our IL does not allow this. */
1753 gcc_assert (c
->rhs
.offset
== 0);
1755 /* If the solution of y contains ANYTHING simply use the ANYTHING
1756 solution. This avoids needlessly increasing the points-to sets. */
1757 if (bitmap_bit_p (sol
, anything_id
))
1758 sol
= get_varinfo (find (anything_id
))->solution
;
1760 /* If the solution for x contains ANYTHING we have to merge the
1761 solution of y into all pointer variables which we do via
1763 if (bitmap_bit_p (delta
, anything_id
))
1765 unsigned t
= find (storedanything_id
);
1766 if (add_graph_edge (graph
, t
, rhs
))
1768 if (bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1770 if (!TEST_BIT (changed
, t
))
1772 SET_BIT (changed
, t
);
1780 /* If we do not know at with offset the rhs is dereferenced compute
1781 the reachability set of DELTA, conservatively assuming it is
1782 dereferenced at all valid offsets. */
1783 if (loff
== UNKNOWN_OFFSET
)
1785 solution_set_expand (delta
, delta
);
1789 /* For each member j of delta (Sol(x)), add an edge from y to j and
1790 union Sol(y) into Sol(j) */
1791 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, j
, bi
)
1793 varinfo_t v
= get_varinfo (j
);
1795 HOST_WIDE_INT fieldoffset
= v
->offset
+ loff
;
1798 fieldoffset
= v
->offset
;
1800 v
= first_vi_for_offset (v
, fieldoffset
);
1801 /* If the access is outside of the variable we can ignore it. */
1807 if (v
->may_have_pointers
)
1809 /* If v is a global variable then this is an escape point. */
1810 if (v
->is_global_var
1813 t
= find (escaped_id
);
1814 if (add_graph_edge (graph
, t
, rhs
)
1815 && bitmap_ior_into (get_varinfo (t
)->solution
, sol
)
1816 && !TEST_BIT (changed
, t
))
1818 SET_BIT (changed
, t
);
1821 /* Enough to let rhs escape once. */
1825 if (v
->is_special_var
)
1829 if (add_graph_edge (graph
, t
, rhs
)
1830 && bitmap_ior_into (get_varinfo (t
)->solution
, sol
)
1831 && !TEST_BIT (changed
, t
))
1833 SET_BIT (changed
, t
);
1838 /* If the variable is not exactly at the requested offset
1839 we have to include the next one. */
1840 if (v
->offset
== (unsigned HOST_WIDE_INT
)fieldoffset
1845 fieldoffset
= v
->offset
;
1851 /* Handle a non-simple (simple meaning requires no iteration),
1852 constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
1855 do_complex_constraint (constraint_graph_t graph
, constraint_t c
, bitmap delta
)
1857 if (c
->lhs
.type
== DEREF
)
1859 if (c
->rhs
.type
== ADDRESSOF
)
1866 do_ds_constraint (c
, delta
);
1869 else if (c
->rhs
.type
== DEREF
)
1872 if (!(get_varinfo (c
->lhs
.var
)->is_special_var
))
1873 do_sd_constraint (graph
, c
, delta
);
1881 gcc_assert (c
->rhs
.type
== SCALAR
&& c
->lhs
.type
== SCALAR
);
1882 solution
= get_varinfo (c
->rhs
.var
)->solution
;
1883 tmp
= get_varinfo (c
->lhs
.var
)->solution
;
1885 flag
= set_union_with_increment (tmp
, solution
, c
->rhs
.offset
);
1889 get_varinfo (c
->lhs
.var
)->solution
= tmp
;
1890 if (!TEST_BIT (changed
, c
->lhs
.var
))
1892 SET_BIT (changed
, c
->lhs
.var
);
1899 /* Initialize and return a new SCC info structure. */
1901 static struct scc_info
*
1902 init_scc_info (size_t size
)
1904 struct scc_info
*si
= XNEW (struct scc_info
);
1907 si
->current_index
= 0;
1908 si
->visited
= sbitmap_alloc (size
);
1909 sbitmap_zero (si
->visited
);
1910 si
->deleted
= sbitmap_alloc (size
);
1911 sbitmap_zero (si
->deleted
);
1912 si
->node_mapping
= XNEWVEC (unsigned int, size
);
1913 si
->dfs
= XCNEWVEC (unsigned int, size
);
1915 for (i
= 0; i
< size
; i
++)
1916 si
->node_mapping
[i
] = i
;
1918 si
->scc_stack
= VEC_alloc (unsigned, heap
, 1);
1922 /* Free an SCC info structure pointed to by SI */
1925 free_scc_info (struct scc_info
*si
)
1927 sbitmap_free (si
->visited
);
1928 sbitmap_free (si
->deleted
);
1929 free (si
->node_mapping
);
1931 VEC_free (unsigned, heap
, si
->scc_stack
);
1936 /* Find indirect cycles in GRAPH that occur, using strongly connected
1937 components, and note them in the indirect cycles map.
1939 This technique comes from Ben Hardekopf and Calvin Lin,
1940 "It Pays to be Lazy: Fast and Accurate Pointer Analysis for Millions of
1941 Lines of Code", submitted to PLDI 2007. */
1944 find_indirect_cycles (constraint_graph_t graph
)
1947 unsigned int size
= graph
->size
;
1948 struct scc_info
*si
= init_scc_info (size
);
1950 for (i
= 0; i
< MIN (LAST_REF_NODE
, size
); i
++ )
1951 if (!TEST_BIT (si
->visited
, i
) && find (i
) == i
)
1952 scc_visit (graph
, si
, i
);
1957 /* Compute a topological ordering for GRAPH, and store the result in the
1958 topo_info structure TI. */
1961 compute_topo_order (constraint_graph_t graph
,
1962 struct topo_info
*ti
)
1965 unsigned int size
= graph
->size
;
1967 for (i
= 0; i
!= size
; ++i
)
1968 if (!TEST_BIT (ti
->visited
, i
) && find (i
) == i
)
1969 topo_visit (graph
, ti
, i
);
1972 /* Structure used to for hash value numbering of pointer equivalence
1975 typedef struct equiv_class_label
1978 unsigned int equivalence_class
;
1980 } *equiv_class_label_t
;
1981 typedef const struct equiv_class_label
*const_equiv_class_label_t
;
1983 /* A hashtable for mapping a bitmap of labels->pointer equivalence
1985 static htab_t pointer_equiv_class_table
;
1987 /* A hashtable for mapping a bitmap of labels->location equivalence
1989 static htab_t location_equiv_class_table
;
1991 /* Hash function for a equiv_class_label_t */
1994 equiv_class_label_hash (const void *p
)
1996 const_equiv_class_label_t
const ecl
= (const_equiv_class_label_t
) p
;
1997 return ecl
->hashcode
;
2000 /* Equality function for two equiv_class_label_t's. */
2003 equiv_class_label_eq (const void *p1
, const void *p2
)
2005 const_equiv_class_label_t
const eql1
= (const_equiv_class_label_t
) p1
;
2006 const_equiv_class_label_t
const eql2
= (const_equiv_class_label_t
) p2
;
2007 return (eql1
->hashcode
== eql2
->hashcode
2008 && bitmap_equal_p (eql1
->labels
, eql2
->labels
));
2011 /* Lookup a equivalence class in TABLE by the bitmap of LABELS it
2015 equiv_class_lookup (htab_t table
, bitmap labels
)
2018 struct equiv_class_label ecl
;
2020 ecl
.labels
= labels
;
2021 ecl
.hashcode
= bitmap_hash (labels
);
2023 slot
= htab_find_slot_with_hash (table
, &ecl
,
2024 ecl
.hashcode
, NO_INSERT
);
2028 return ((equiv_class_label_t
) *slot
)->equivalence_class
;
2032 /* Add an equivalence class named EQUIVALENCE_CLASS with labels LABELS
2036 equiv_class_add (htab_t table
, unsigned int equivalence_class
,
2040 equiv_class_label_t ecl
= XNEW (struct equiv_class_label
);
2042 ecl
->labels
= labels
;
2043 ecl
->equivalence_class
= equivalence_class
;
2044 ecl
->hashcode
= bitmap_hash (labels
);
2046 slot
= htab_find_slot_with_hash (table
, ecl
,
2047 ecl
->hashcode
, INSERT
);
2048 gcc_assert (!*slot
);
2049 *slot
= (void *) ecl
;
2052 /* Perform offline variable substitution.
2054 This is a worst case quadratic time way of identifying variables
2055 that must have equivalent points-to sets, including those caused by
2056 static cycles, and single entry subgraphs, in the constraint graph.
2058 The technique is described in "Exploiting Pointer and Location
2059 Equivalence to Optimize Pointer Analysis. In the 14th International
2060 Static Analysis Symposium (SAS), August 2007." It is known as the
2061 "HU" algorithm, and is equivalent to value numbering the collapsed
2062 constraint graph including evaluating unions.
2064 The general method of finding equivalence classes is as follows:
2065 Add fake nodes (REF nodes) and edges for *a = b and a = *b constraints.
2066 Initialize all non-REF nodes to be direct nodes.
2067 For each constraint a = a U {b}, we set pts(a) = pts(a) u {fresh
2069 For each constraint containing the dereference, we also do the same
2072 We then compute SCC's in the graph and unify nodes in the same SCC,
2075 For each non-collapsed node x:
2076 Visit all unvisited explicit incoming edges.
2077 Ignoring all non-pointers, set pts(x) = Union of pts(a) for y
2079 Lookup the equivalence class for pts(x).
2080 If we found one, equivalence_class(x) = found class.
2081 Otherwise, equivalence_class(x) = new class, and new_class is
2082 added to the lookup table.
2084 All direct nodes with the same equivalence class can be replaced
2085 with a single representative node.
2086 All unlabeled nodes (label == 0) are not pointers and all edges
2087 involving them can be eliminated.
2088 We perform these optimizations during rewrite_constraints
2090 In addition to pointer equivalence class finding, we also perform
2091 location equivalence class finding. This is the set of variables
2092 that always appear together in points-to sets. We use this to
2093 compress the size of the points-to sets. */
2095 /* Current maximum pointer equivalence class id. */
2096 static int pointer_equiv_class
;
2098 /* Current maximum location equivalence class id. */
2099 static int location_equiv_class
;
2101 /* Recursive routine to find strongly connected components in GRAPH,
2102 and label it's nodes with DFS numbers. */
2105 condense_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
2109 unsigned int my_dfs
;
2111 gcc_assert (si
->node_mapping
[n
] == n
);
2112 SET_BIT (si
->visited
, n
);
2113 si
->dfs
[n
] = si
->current_index
++;
2114 my_dfs
= si
->dfs
[n
];
2116 /* Visit all the successors. */
2117 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[n
], 0, i
, bi
)
2119 unsigned int w
= si
->node_mapping
[i
];
2121 if (TEST_BIT (si
->deleted
, w
))
2124 if (!TEST_BIT (si
->visited
, w
))
2125 condense_visit (graph
, si
, w
);
2127 unsigned int t
= si
->node_mapping
[w
];
2128 unsigned int nnode
= si
->node_mapping
[n
];
2129 gcc_assert (nnode
== n
);
2131 if (si
->dfs
[t
] < si
->dfs
[nnode
])
2132 si
->dfs
[n
] = si
->dfs
[t
];
2136 /* Visit all the implicit predecessors. */
2137 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->implicit_preds
[n
], 0, i
, bi
)
2139 unsigned int w
= si
->node_mapping
[i
];
2141 if (TEST_BIT (si
->deleted
, w
))
2144 if (!TEST_BIT (si
->visited
, w
))
2145 condense_visit (graph
, si
, w
);
2147 unsigned int t
= si
->node_mapping
[w
];
2148 unsigned int nnode
= si
->node_mapping
[n
];
2149 gcc_assert (nnode
== n
);
2151 if (si
->dfs
[t
] < si
->dfs
[nnode
])
2152 si
->dfs
[n
] = si
->dfs
[t
];
2156 /* See if any components have been identified. */
2157 if (si
->dfs
[n
] == my_dfs
)
2159 while (VEC_length (unsigned, si
->scc_stack
) != 0
2160 && si
->dfs
[VEC_last (unsigned, si
->scc_stack
)] >= my_dfs
)
2162 unsigned int w
= VEC_pop (unsigned, si
->scc_stack
);
2163 si
->node_mapping
[w
] = n
;
2165 if (!TEST_BIT (graph
->direct_nodes
, w
))
2166 RESET_BIT (graph
->direct_nodes
, n
);
2168 /* Unify our nodes. */
2169 if (graph
->preds
[w
])
2171 if (!graph
->preds
[n
])
2172 graph
->preds
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2173 bitmap_ior_into (graph
->preds
[n
], graph
->preds
[w
]);
2175 if (graph
->implicit_preds
[w
])
2177 if (!graph
->implicit_preds
[n
])
2178 graph
->implicit_preds
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2179 bitmap_ior_into (graph
->implicit_preds
[n
],
2180 graph
->implicit_preds
[w
]);
2182 if (graph
->points_to
[w
])
2184 if (!graph
->points_to
[n
])
2185 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2186 bitmap_ior_into (graph
->points_to
[n
],
2187 graph
->points_to
[w
]);
2190 SET_BIT (si
->deleted
, n
);
2193 VEC_safe_push (unsigned, heap
, si
->scc_stack
, n
);
2196 /* Label pointer equivalences. */
2199 label_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
2203 SET_BIT (si
->visited
, n
);
2205 if (!graph
->points_to
[n
])
2206 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2208 /* Label and union our incoming edges's points to sets. */
2209 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[n
], 0, i
, bi
)
2211 unsigned int w
= si
->node_mapping
[i
];
2212 if (!TEST_BIT (si
->visited
, w
))
2213 label_visit (graph
, si
, w
);
2215 /* Skip unused edges */
2216 if (w
== n
|| graph
->pointer_label
[w
] == 0)
2219 if (graph
->points_to
[w
])
2220 bitmap_ior_into(graph
->points_to
[n
], graph
->points_to
[w
]);
2222 /* Indirect nodes get fresh variables. */
2223 if (!TEST_BIT (graph
->direct_nodes
, n
))
2224 bitmap_set_bit (graph
->points_to
[n
], FIRST_REF_NODE
+ n
);
2226 if (!bitmap_empty_p (graph
->points_to
[n
]))
2228 unsigned int label
= equiv_class_lookup (pointer_equiv_class_table
,
2229 graph
->points_to
[n
]);
2232 label
= pointer_equiv_class
++;
2233 equiv_class_add (pointer_equiv_class_table
,
2234 label
, graph
->points_to
[n
]);
2236 graph
->pointer_label
[n
] = label
;
2240 /* Perform offline variable substitution, discovering equivalence
2241 classes, and eliminating non-pointer variables. */
2243 static struct scc_info
*
2244 perform_var_substitution (constraint_graph_t graph
)
2247 unsigned int size
= graph
->size
;
2248 struct scc_info
*si
= init_scc_info (size
);
2250 bitmap_obstack_initialize (&iteration_obstack
);
2251 pointer_equiv_class_table
= htab_create (511, equiv_class_label_hash
,
2252 equiv_class_label_eq
, free
);
2253 location_equiv_class_table
= htab_create (511, equiv_class_label_hash
,
2254 equiv_class_label_eq
, free
);
2255 pointer_equiv_class
= 1;
2256 location_equiv_class
= 1;
2258 /* Condense the nodes, which means to find SCC's, count incoming
2259 predecessors, and unite nodes in SCC's. */
2260 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2261 if (!TEST_BIT (si
->visited
, si
->node_mapping
[i
]))
2262 condense_visit (graph
, si
, si
->node_mapping
[i
]);
2264 sbitmap_zero (si
->visited
);
2265 /* Actually the label the nodes for pointer equivalences */
2266 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2267 if (!TEST_BIT (si
->visited
, si
->node_mapping
[i
]))
2268 label_visit (graph
, si
, si
->node_mapping
[i
]);
2270 /* Calculate location equivalence labels. */
2271 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2278 if (!graph
->pointed_by
[i
])
2280 pointed_by
= BITMAP_ALLOC (&iteration_obstack
);
2282 /* Translate the pointed-by mapping for pointer equivalence
2284 EXECUTE_IF_SET_IN_BITMAP (graph
->pointed_by
[i
], 0, j
, bi
)
2286 bitmap_set_bit (pointed_by
,
2287 graph
->pointer_label
[si
->node_mapping
[j
]]);
2289 /* The original pointed_by is now dead. */
2290 BITMAP_FREE (graph
->pointed_by
[i
]);
2292 /* Look up the location equivalence label if one exists, or make
2294 label
= equiv_class_lookup (location_equiv_class_table
,
2298 label
= location_equiv_class
++;
2299 equiv_class_add (location_equiv_class_table
,
2304 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2305 fprintf (dump_file
, "Found location equivalence for node %s\n",
2306 get_varinfo (i
)->name
);
2307 BITMAP_FREE (pointed_by
);
2309 graph
->loc_label
[i
] = label
;
2313 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2314 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2316 bool direct_node
= TEST_BIT (graph
->direct_nodes
, i
);
2318 "Equivalence classes for %s node id %d:%s are pointer: %d"
2320 direct_node
? "Direct node" : "Indirect node", i
,
2321 get_varinfo (i
)->name
,
2322 graph
->pointer_label
[si
->node_mapping
[i
]],
2323 graph
->loc_label
[si
->node_mapping
[i
]]);
2326 /* Quickly eliminate our non-pointer variables. */
2328 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2330 unsigned int node
= si
->node_mapping
[i
];
2332 if (graph
->pointer_label
[node
] == 0)
2334 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2336 "%s is a non-pointer variable, eliminating edges.\n",
2337 get_varinfo (node
)->name
);
2338 stats
.nonpointer_vars
++;
2339 clear_edges_for_node (graph
, node
);
2346 /* Free information that was only necessary for variable
2350 free_var_substitution_info (struct scc_info
*si
)
2353 free (graph
->pointer_label
);
2354 free (graph
->loc_label
);
2355 free (graph
->pointed_by
);
2356 free (graph
->points_to
);
2357 free (graph
->eq_rep
);
2358 sbitmap_free (graph
->direct_nodes
);
2359 htab_delete (pointer_equiv_class_table
);
2360 htab_delete (location_equiv_class_table
);
2361 bitmap_obstack_release (&iteration_obstack
);
2364 /* Return an existing node that is equivalent to NODE, which has
2365 equivalence class LABEL, if one exists. Return NODE otherwise. */
2368 find_equivalent_node (constraint_graph_t graph
,
2369 unsigned int node
, unsigned int label
)
2371 /* If the address version of this variable is unused, we can
2372 substitute it for anything else with the same label.
2373 Otherwise, we know the pointers are equivalent, but not the
2374 locations, and we can unite them later. */
2376 if (!bitmap_bit_p (graph
->address_taken
, node
))
2378 gcc_assert (label
< graph
->size
);
2380 if (graph
->eq_rep
[label
] != -1)
2382 /* Unify the two variables since we know they are equivalent. */
2383 if (unite (graph
->eq_rep
[label
], node
))
2384 unify_nodes (graph
, graph
->eq_rep
[label
], node
, false);
2385 return graph
->eq_rep
[label
];
2389 graph
->eq_rep
[label
] = node
;
2390 graph
->pe_rep
[label
] = node
;
2395 gcc_assert (label
< graph
->size
);
2396 graph
->pe
[node
] = label
;
2397 if (graph
->pe_rep
[label
] == -1)
2398 graph
->pe_rep
[label
] = node
;
2404 /* Unite pointer equivalent but not location equivalent nodes in
2405 GRAPH. This may only be performed once variable substitution is
2409 unite_pointer_equivalences (constraint_graph_t graph
)
2413 /* Go through the pointer equivalences and unite them to their
2414 representative, if they aren't already. */
2415 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
2417 unsigned int label
= graph
->pe
[i
];
2420 int label_rep
= graph
->pe_rep
[label
];
2422 if (label_rep
== -1)
2425 label_rep
= find (label_rep
);
2426 if (label_rep
>= 0 && unite (label_rep
, find (i
)))
2427 unify_nodes (graph
, label_rep
, i
, false);
2432 /* Move complex constraints to the GRAPH nodes they belong to. */
2435 move_complex_constraints (constraint_graph_t graph
)
2440 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
2444 struct constraint_expr lhs
= c
->lhs
;
2445 struct constraint_expr rhs
= c
->rhs
;
2447 if (lhs
.type
== DEREF
)
2449 insert_into_complex (graph
, lhs
.var
, c
);
2451 else if (rhs
.type
== DEREF
)
2453 if (!(get_varinfo (lhs
.var
)->is_special_var
))
2454 insert_into_complex (graph
, rhs
.var
, c
);
2456 else if (rhs
.type
!= ADDRESSOF
&& lhs
.var
> anything_id
2457 && (lhs
.offset
!= 0 || rhs
.offset
!= 0))
2459 insert_into_complex (graph
, rhs
.var
, c
);
2466 /* Optimize and rewrite complex constraints while performing
2467 collapsing of equivalent nodes. SI is the SCC_INFO that is the
2468 result of perform_variable_substitution. */
2471 rewrite_constraints (constraint_graph_t graph
,
2472 struct scc_info
*si
)
2478 for (j
= 0; j
< graph
->size
; j
++)
2479 gcc_assert (find (j
) == j
);
2481 FOR_EACH_VEC_ELT (constraint_t
, constraints
, i
, c
)
2483 struct constraint_expr lhs
= c
->lhs
;
2484 struct constraint_expr rhs
= c
->rhs
;
2485 unsigned int lhsvar
= find (lhs
.var
);
2486 unsigned int rhsvar
= find (rhs
.var
);
2487 unsigned int lhsnode
, rhsnode
;
2488 unsigned int lhslabel
, rhslabel
;
2490 lhsnode
= si
->node_mapping
[lhsvar
];
2491 rhsnode
= si
->node_mapping
[rhsvar
];
2492 lhslabel
= graph
->pointer_label
[lhsnode
];
2493 rhslabel
= graph
->pointer_label
[rhsnode
];
2495 /* See if it is really a non-pointer variable, and if so, ignore
2499 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2502 fprintf (dump_file
, "%s is a non-pointer variable,"
2503 "ignoring constraint:",
2504 get_varinfo (lhs
.var
)->name
);
2505 dump_constraint (dump_file
, c
);
2507 VEC_replace (constraint_t
, constraints
, i
, NULL
);
2513 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2516 fprintf (dump_file
, "%s is a non-pointer variable,"
2517 "ignoring constraint:",
2518 get_varinfo (rhs
.var
)->name
);
2519 dump_constraint (dump_file
, c
);
2521 VEC_replace (constraint_t
, constraints
, i
, NULL
);
2525 lhsvar
= find_equivalent_node (graph
, lhsvar
, lhslabel
);
2526 rhsvar
= find_equivalent_node (graph
, rhsvar
, rhslabel
);
2527 c
->lhs
.var
= lhsvar
;
2528 c
->rhs
.var
= rhsvar
;
2533 /* Eliminate indirect cycles involving NODE. Return true if NODE was
2534 part of an SCC, false otherwise. */
2537 eliminate_indirect_cycles (unsigned int node
)
2539 if (graph
->indirect_cycles
[node
] != -1
2540 && !bitmap_empty_p (get_varinfo (node
)->solution
))
2543 VEC(unsigned,heap
) *queue
= NULL
;
2545 unsigned int to
= find (graph
->indirect_cycles
[node
]);
2548 /* We can't touch the solution set and call unify_nodes
2549 at the same time, because unify_nodes is going to do
2550 bitmap unions into it. */
2552 EXECUTE_IF_SET_IN_BITMAP (get_varinfo (node
)->solution
, 0, i
, bi
)
2554 if (find (i
) == i
&& i
!= to
)
2557 VEC_safe_push (unsigned, heap
, queue
, i
);
2562 VEC_iterate (unsigned, queue
, queuepos
, i
);
2565 unify_nodes (graph
, to
, i
, true);
2567 VEC_free (unsigned, heap
, queue
);
2573 /* Solve the constraint graph GRAPH using our worklist solver.
2574 This is based on the PW* family of solvers from the "Efficient Field
2575 Sensitive Pointer Analysis for C" paper.
2576 It works by iterating over all the graph nodes, processing the complex
2577 constraints and propagating the copy constraints, until everything stops
2578 changed. This corresponds to steps 6-8 in the solving list given above. */
2581 solve_graph (constraint_graph_t graph
)
2583 unsigned int size
= graph
->size
;
2588 changed
= sbitmap_alloc (size
);
2589 sbitmap_zero (changed
);
2591 /* Mark all initial non-collapsed nodes as changed. */
2592 for (i
= 0; i
< size
; i
++)
2594 varinfo_t ivi
= get_varinfo (i
);
2595 if (find (i
) == i
&& !bitmap_empty_p (ivi
->solution
)
2596 && ((graph
->succs
[i
] && !bitmap_empty_p (graph
->succs
[i
]))
2597 || VEC_length (constraint_t
, graph
->complex[i
]) > 0))
2599 SET_BIT (changed
, i
);
2604 /* Allocate a bitmap to be used to store the changed bits. */
2605 pts
= BITMAP_ALLOC (&pta_obstack
);
2607 while (changed_count
> 0)
2610 struct topo_info
*ti
= init_topo_info ();
2613 bitmap_obstack_initialize (&iteration_obstack
);
2615 compute_topo_order (graph
, ti
);
2617 while (VEC_length (unsigned, ti
->topo_order
) != 0)
2620 i
= VEC_pop (unsigned, ti
->topo_order
);
2622 /* If this variable is not a representative, skip it. */
2626 /* In certain indirect cycle cases, we may merge this
2627 variable to another. */
2628 if (eliminate_indirect_cycles (i
) && find (i
) != i
)
2631 /* If the node has changed, we need to process the
2632 complex constraints and outgoing edges again. */
2633 if (TEST_BIT (changed
, i
))
2638 VEC(constraint_t
,heap
) *complex = graph
->complex[i
];
2639 bool solution_empty
;
2641 RESET_BIT (changed
, i
);
2644 /* Compute the changed set of solution bits. */
2645 bitmap_and_compl (pts
, get_varinfo (i
)->solution
,
2646 get_varinfo (i
)->oldsolution
);
2648 if (bitmap_empty_p (pts
))
2651 bitmap_ior_into (get_varinfo (i
)->oldsolution
, pts
);
2653 solution
= get_varinfo (i
)->solution
;
2654 solution_empty
= bitmap_empty_p (solution
);
2656 /* Process the complex constraints */
2657 FOR_EACH_VEC_ELT (constraint_t
, complex, j
, c
)
2659 /* XXX: This is going to unsort the constraints in
2660 some cases, which will occasionally add duplicate
2661 constraints during unification. This does not
2662 affect correctness. */
2663 c
->lhs
.var
= find (c
->lhs
.var
);
2664 c
->rhs
.var
= find (c
->rhs
.var
);
2666 /* The only complex constraint that can change our
2667 solution to non-empty, given an empty solution,
2668 is a constraint where the lhs side is receiving
2669 some set from elsewhere. */
2670 if (!solution_empty
|| c
->lhs
.type
!= DEREF
)
2671 do_complex_constraint (graph
, c
, pts
);
2674 solution_empty
= bitmap_empty_p (solution
);
2676 if (!solution_empty
)
2679 unsigned eff_escaped_id
= find (escaped_id
);
2681 /* Propagate solution to all successors. */
2682 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[i
],
2688 unsigned int to
= find (j
);
2689 tmp
= get_varinfo (to
)->solution
;
2692 /* Don't try to propagate to ourselves. */
2696 /* If we propagate from ESCAPED use ESCAPED as
2698 if (i
== eff_escaped_id
)
2699 flag
= bitmap_set_bit (tmp
, escaped_id
);
2701 flag
= set_union_with_increment (tmp
, pts
, 0);
2705 get_varinfo (to
)->solution
= tmp
;
2706 if (!TEST_BIT (changed
, to
))
2708 SET_BIT (changed
, to
);
2716 free_topo_info (ti
);
2717 bitmap_obstack_release (&iteration_obstack
);
2721 sbitmap_free (changed
);
2722 bitmap_obstack_release (&oldpta_obstack
);
2725 /* Map from trees to variable infos. */
2726 static struct pointer_map_t
*vi_for_tree
;
2729 /* Insert ID as the variable id for tree T in the vi_for_tree map. */
2732 insert_vi_for_tree (tree t
, varinfo_t vi
)
2734 void **slot
= pointer_map_insert (vi_for_tree
, t
);
2736 gcc_assert (*slot
== NULL
);
2740 /* Find the variable info for tree T in VI_FOR_TREE. If T does not
2741 exist in the map, return NULL, otherwise, return the varinfo we found. */
2744 lookup_vi_for_tree (tree t
)
2746 void **slot
= pointer_map_contains (vi_for_tree
, t
);
2750 return (varinfo_t
) *slot
;
2753 /* Return a printable name for DECL */
2756 alias_get_name (tree decl
)
2760 int num_printed
= 0;
2762 if (DECL_ASSEMBLER_NAME_SET_P (decl
))
2763 res
= IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl
));
2765 res
= get_name (decl
);
2773 if (TREE_CODE (decl
) == SSA_NAME
)
2775 num_printed
= asprintf (&temp
, "%s_%u",
2776 alias_get_name (SSA_NAME_VAR (decl
)),
2777 SSA_NAME_VERSION (decl
));
2779 else if (DECL_P (decl
))
2781 num_printed
= asprintf (&temp
, "D.%u", DECL_UID (decl
));
2783 if (num_printed
> 0)
2785 res
= ggc_strdup (temp
);
2791 /* Find the variable id for tree T in the map.
2792 If T doesn't exist in the map, create an entry for it and return it. */
2795 get_vi_for_tree (tree t
)
2797 void **slot
= pointer_map_contains (vi_for_tree
, t
);
2799 return get_varinfo (create_variable_info_for (t
, alias_get_name (t
)));
2801 return (varinfo_t
) *slot
;
2804 /* Get a scalar constraint expression for a new temporary variable. */
2806 static struct constraint_expr
2807 new_scalar_tmp_constraint_exp (const char *name
)
2809 struct constraint_expr tmp
;
2812 vi
= new_var_info (NULL_TREE
, name
);
2816 vi
->is_full_var
= 1;
2825 /* Get a constraint expression vector from an SSA_VAR_P node.
2826 If address_p is true, the result will be taken its address of. */
2829 get_constraint_for_ssa_var (tree t
, VEC(ce_s
, heap
) **results
, bool address_p
)
2831 struct constraint_expr cexpr
;
2834 /* We allow FUNCTION_DECLs here even though it doesn't make much sense. */
2835 gcc_assert (SSA_VAR_P (t
) || DECL_P (t
));
2837 /* For parameters, get at the points-to set for the actual parm
2839 if (TREE_CODE (t
) == SSA_NAME
2840 && (TREE_CODE (SSA_NAME_VAR (t
)) == PARM_DECL
2841 || TREE_CODE (SSA_NAME_VAR (t
)) == RESULT_DECL
)
2842 && SSA_NAME_IS_DEFAULT_DEF (t
))
2844 get_constraint_for_ssa_var (SSA_NAME_VAR (t
), results
, address_p
);
2848 vi
= get_vi_for_tree (t
);
2850 cexpr
.type
= SCALAR
;
2852 /* If we determine the result is "anything", and we know this is readonly,
2853 say it points to readonly memory instead. */
2854 if (cexpr
.var
== anything_id
&& TREE_READONLY (t
))
2857 cexpr
.type
= ADDRESSOF
;
2858 cexpr
.var
= readonly_id
;
2861 /* If we are not taking the address of the constraint expr, add all
2862 sub-fiels of the variable as well. */
2864 && !vi
->is_full_var
)
2866 for (; vi
; vi
= vi
->next
)
2869 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
2874 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
2877 /* Process constraint T, performing various simplifications and then
2878 adding it to our list of overall constraints. */
2881 process_constraint (constraint_t t
)
2883 struct constraint_expr rhs
= t
->rhs
;
2884 struct constraint_expr lhs
= t
->lhs
;
2886 gcc_assert (rhs
.var
< VEC_length (varinfo_t
, varmap
));
2887 gcc_assert (lhs
.var
< VEC_length (varinfo_t
, varmap
));
2889 /* If we didn't get any useful constraint from the lhs we get
2890 &ANYTHING as fallback from get_constraint_for. Deal with
2891 it here by turning it into *ANYTHING. */
2892 if (lhs
.type
== ADDRESSOF
2893 && lhs
.var
== anything_id
)
2896 /* ADDRESSOF on the lhs is invalid. */
2897 gcc_assert (lhs
.type
!= ADDRESSOF
);
2899 /* We shouldn't add constraints from things that cannot have pointers.
2900 It's not completely trivial to avoid in the callers, so do it here. */
2901 if (rhs
.type
!= ADDRESSOF
2902 && !get_varinfo (rhs
.var
)->may_have_pointers
)
2905 /* Likewise adding to the solution of a non-pointer var isn't useful. */
2906 if (!get_varinfo (lhs
.var
)->may_have_pointers
)
2909 /* This can happen in our IR with things like n->a = *p */
2910 if (rhs
.type
== DEREF
&& lhs
.type
== DEREF
&& rhs
.var
!= anything_id
)
2912 /* Split into tmp = *rhs, *lhs = tmp */
2913 struct constraint_expr tmplhs
;
2914 tmplhs
= new_scalar_tmp_constraint_exp ("doubledereftmp");
2915 process_constraint (new_constraint (tmplhs
, rhs
));
2916 process_constraint (new_constraint (lhs
, tmplhs
));
2918 else if (rhs
.type
== ADDRESSOF
&& lhs
.type
== DEREF
)
2920 /* Split into tmp = &rhs, *lhs = tmp */
2921 struct constraint_expr tmplhs
;
2922 tmplhs
= new_scalar_tmp_constraint_exp ("derefaddrtmp");
2923 process_constraint (new_constraint (tmplhs
, rhs
));
2924 process_constraint (new_constraint (lhs
, tmplhs
));
2928 gcc_assert (rhs
.type
!= ADDRESSOF
|| rhs
.offset
== 0);
2929 VEC_safe_push (constraint_t
, heap
, constraints
, t
);
2934 /* Return the position, in bits, of FIELD_DECL from the beginning of its
2937 static HOST_WIDE_INT
2938 bitpos_of_field (const tree fdecl
)
2941 if (!host_integerp (DECL_FIELD_OFFSET (fdecl
), 0)
2942 || !host_integerp (DECL_FIELD_BIT_OFFSET (fdecl
), 0))
2945 return (TREE_INT_CST_LOW (DECL_FIELD_OFFSET (fdecl
)) * 8
2946 + TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fdecl
)));
2950 /* Get constraint expressions for offsetting PTR by OFFSET. Stores the
2951 resulting constraint expressions in *RESULTS. */
2954 get_constraint_for_ptr_offset (tree ptr
, tree offset
,
2955 VEC (ce_s
, heap
) **results
)
2957 struct constraint_expr c
;
2959 HOST_WIDE_INT rhsunitoffset
, rhsoffset
;
2961 /* If we do not do field-sensitive PTA adding offsets to pointers
2962 does not change the points-to solution. */
2963 if (!use_field_sensitive
)
2965 get_constraint_for_rhs (ptr
, results
);
2969 /* If the offset is not a non-negative integer constant that fits
2970 in a HOST_WIDE_INT, we have to fall back to a conservative
2971 solution which includes all sub-fields of all pointed-to
2972 variables of ptr. */
2973 if (offset
== NULL_TREE
2974 || !host_integerp (offset
, 0))
2975 rhsoffset
= UNKNOWN_OFFSET
;
2978 /* Make sure the bit-offset also fits. */
2979 rhsunitoffset
= TREE_INT_CST_LOW (offset
);
2980 rhsoffset
= rhsunitoffset
* BITS_PER_UNIT
;
2981 if (rhsunitoffset
!= rhsoffset
/ BITS_PER_UNIT
)
2982 rhsoffset
= UNKNOWN_OFFSET
;
2985 get_constraint_for_rhs (ptr
, results
);
2989 /* As we are eventually appending to the solution do not use
2990 VEC_iterate here. */
2991 n
= VEC_length (ce_s
, *results
);
2992 for (j
= 0; j
< n
; j
++)
2995 c
= *VEC_index (ce_s
, *results
, j
);
2996 curr
= get_varinfo (c
.var
);
2998 if (c
.type
== ADDRESSOF
2999 /* If this varinfo represents a full variable just use it. */
3000 && curr
->is_full_var
)
3002 else if (c
.type
== ADDRESSOF
3003 /* If we do not know the offset add all subfields. */
3004 && rhsoffset
== UNKNOWN_OFFSET
)
3006 varinfo_t temp
= lookup_vi_for_tree (curr
->decl
);
3009 struct constraint_expr c2
;
3011 c2
.type
= ADDRESSOF
;
3013 if (c2
.var
!= c
.var
)
3014 VEC_safe_push (ce_s
, heap
, *results
, &c2
);
3019 else if (c
.type
== ADDRESSOF
)
3022 unsigned HOST_WIDE_INT offset
= curr
->offset
+ rhsoffset
;
3024 /* Search the sub-field which overlaps with the
3025 pointed-to offset. If the result is outside of the variable
3026 we have to provide a conservative result, as the variable is
3027 still reachable from the resulting pointer (even though it
3028 technically cannot point to anything). The last and first
3029 sub-fields are such conservative results.
3030 ??? If we always had a sub-field for &object + 1 then
3031 we could represent this in a more precise way. */
3033 && curr
->offset
< offset
)
3035 temp
= first_or_preceding_vi_for_offset (curr
, offset
);
3037 /* If the found variable is not exactly at the pointed to
3038 result, we have to include the next variable in the
3039 solution as well. Otherwise two increments by offset / 2
3040 do not result in the same or a conservative superset
3042 if (temp
->offset
!= offset
3043 && temp
->next
!= NULL
)
3045 struct constraint_expr c2
;
3046 c2
.var
= temp
->next
->id
;
3047 c2
.type
= ADDRESSOF
;
3049 VEC_safe_push (ce_s
, heap
, *results
, &c2
);
3055 c
.offset
= rhsoffset
;
3057 VEC_replace (ce_s
, *results
, j
, &c
);
3062 /* Given a COMPONENT_REF T, return the constraint_expr vector for it.
3063 If address_p is true the result will be taken its address of.
3064 If lhs_p is true then the constraint expression is assumed to be used
3068 get_constraint_for_component_ref (tree t
, VEC(ce_s
, heap
) **results
,
3069 bool address_p
, bool lhs_p
)
3072 HOST_WIDE_INT bitsize
= -1;
3073 HOST_WIDE_INT bitmaxsize
= -1;
3074 HOST_WIDE_INT bitpos
;
3076 struct constraint_expr
*result
;
3078 /* Some people like to do cute things like take the address of
3081 while (handled_component_p (forzero
)
3082 || INDIRECT_REF_P (forzero
)
3083 || TREE_CODE (forzero
) == MEM_REF
)
3084 forzero
= TREE_OPERAND (forzero
, 0);
3086 if (CONSTANT_CLASS_P (forzero
) && integer_zerop (forzero
))
3088 struct constraint_expr temp
;
3091 temp
.var
= integer_id
;
3093 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3097 /* Handle type-punning through unions. If we are extracting a pointer
3098 from a union via a possibly type-punning access that pointer
3099 points to anything, similar to a conversion of an integer to
3105 TREE_CODE (u
) == COMPONENT_REF
|| TREE_CODE (u
) == ARRAY_REF
;
3106 u
= TREE_OPERAND (u
, 0))
3107 if (TREE_CODE (u
) == COMPONENT_REF
3108 && TREE_CODE (TREE_TYPE (TREE_OPERAND (u
, 0))) == UNION_TYPE
)
3110 struct constraint_expr temp
;
3113 temp
.var
= anything_id
;
3114 temp
.type
= ADDRESSOF
;
3115 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3120 t
= get_ref_base_and_extent (t
, &bitpos
, &bitsize
, &bitmaxsize
);
3122 /* Pretend to take the address of the base, we'll take care of
3123 adding the required subset of sub-fields below. */
3124 get_constraint_for_1 (t
, results
, true, lhs_p
);
3125 gcc_assert (VEC_length (ce_s
, *results
) == 1);
3126 result
= VEC_last (ce_s
, *results
);
3128 if (result
->type
== SCALAR
3129 && get_varinfo (result
->var
)->is_full_var
)
3130 /* For single-field vars do not bother about the offset. */
3132 else if (result
->type
== SCALAR
)
3134 /* In languages like C, you can access one past the end of an
3135 array. You aren't allowed to dereference it, so we can
3136 ignore this constraint. When we handle pointer subtraction,
3137 we may have to do something cute here. */
3139 if ((unsigned HOST_WIDE_INT
)bitpos
< get_varinfo (result
->var
)->fullsize
3142 /* It's also not true that the constraint will actually start at the
3143 right offset, it may start in some padding. We only care about
3144 setting the constraint to the first actual field it touches, so
3146 struct constraint_expr cexpr
= *result
;
3148 VEC_pop (ce_s
, *results
);
3150 for (curr
= get_varinfo (cexpr
.var
); curr
; curr
= curr
->next
)
3152 if (ranges_overlap_p (curr
->offset
, curr
->size
,
3153 bitpos
, bitmaxsize
))
3155 cexpr
.var
= curr
->id
;
3156 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
3161 /* If we are going to take the address of this field then
3162 to be able to compute reachability correctly add at least
3163 the last field of the variable. */
3165 && VEC_length (ce_s
, *results
) == 0)
3167 curr
= get_varinfo (cexpr
.var
);
3168 while (curr
->next
!= NULL
)
3170 cexpr
.var
= curr
->id
;
3171 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
3173 else if (VEC_length (ce_s
, *results
) == 0)
3174 /* Assert that we found *some* field there. The user couldn't be
3175 accessing *only* padding. */
3176 /* Still the user could access one past the end of an array
3177 embedded in a struct resulting in accessing *only* padding. */
3178 /* Or accessing only padding via type-punning to a type
3179 that has a filed just in padding space. */
3181 cexpr
.type
= SCALAR
;
3182 cexpr
.var
= anything_id
;
3184 VEC_safe_push (ce_s
, heap
, *results
, &cexpr
);
3187 else if (bitmaxsize
== 0)
3189 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3190 fprintf (dump_file
, "Access to zero-sized part of variable,"
3194 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3195 fprintf (dump_file
, "Access to past the end of variable, ignoring\n");
3197 else if (result
->type
== DEREF
)
3199 /* If we do not know exactly where the access goes say so. Note
3200 that only for non-structure accesses we know that we access
3201 at most one subfiled of any variable. */
3203 || bitsize
!= bitmaxsize
3204 || AGGREGATE_TYPE_P (TREE_TYPE (orig_t
))
3205 || result
->offset
== UNKNOWN_OFFSET
)
3206 result
->offset
= UNKNOWN_OFFSET
;
3208 result
->offset
+= bitpos
;
3210 else if (result
->type
== ADDRESSOF
)
3212 /* We can end up here for component references on a
3213 VIEW_CONVERT_EXPR <>(&foobar). */
3214 result
->type
= SCALAR
;
3215 result
->var
= anything_id
;
3223 /* Dereference the constraint expression CONS, and return the result.
3224 DEREF (ADDRESSOF) = SCALAR
3225 DEREF (SCALAR) = DEREF
3226 DEREF (DEREF) = (temp = DEREF1; result = DEREF(temp))
3227 This is needed so that we can handle dereferencing DEREF constraints. */
3230 do_deref (VEC (ce_s
, heap
) **constraints
)
3232 struct constraint_expr
*c
;
3235 FOR_EACH_VEC_ELT (ce_s
, *constraints
, i
, c
)
3237 if (c
->type
== SCALAR
)
3239 else if (c
->type
== ADDRESSOF
)
3241 else if (c
->type
== DEREF
)
3243 struct constraint_expr tmplhs
;
3244 tmplhs
= new_scalar_tmp_constraint_exp ("dereftmp");
3245 process_constraint (new_constraint (tmplhs
, *c
));
3246 c
->var
= tmplhs
.var
;
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, true);
3264 FOR_EACH_VEC_ELT (ce_s
, *results
, i
, c
)
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
,
3279 struct constraint_expr temp
;
3281 /* x = integer is all glommed to a single variable, which doesn't
3282 point to anything by itself. That is, of course, unless it is an
3283 integer constant being treated as a pointer, in which case, we
3284 will return that this is really the addressof anything. This
3285 happens below, since it will fall into the default case. The only
3286 case we know something about an integer treated like a pointer is
3287 when it is the NULL pointer, and then we just say it points to
3290 Do not do that if -fno-delete-null-pointer-checks though, because
3291 in that case *NULL does not fail, so it _should_ alias *anything.
3292 It is not worth adding a new option or renaming the existing one,
3293 since this case is relatively obscure. */
3294 if ((TREE_CODE (t
) == INTEGER_CST
3295 && integer_zerop (t
))
3296 /* The only valid CONSTRUCTORs in gimple with pointer typed
3297 elements are zero-initializer. But in IPA mode we also
3298 process global initializers, so verify at least. */
3299 || (TREE_CODE (t
) == CONSTRUCTOR
3300 && CONSTRUCTOR_NELTS (t
) == 0))
3302 if (flag_delete_null_pointer_checks
)
3303 temp
.var
= nothing_id
;
3305 temp
.var
= nonlocal_id
;
3306 temp
.type
= ADDRESSOF
;
3308 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3312 /* String constants are read-only. */
3313 if (TREE_CODE (t
) == STRING_CST
)
3315 temp
.var
= readonly_id
;
3318 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3322 switch (TREE_CODE_CLASS (TREE_CODE (t
)))
3324 case tcc_expression
:
3326 switch (TREE_CODE (t
))
3329 get_constraint_for_address_of (TREE_OPERAND (t
, 0), results
);
3337 switch (TREE_CODE (t
))
3341 struct constraint_expr cs
;
3343 tree off
= double_int_to_tree (sizetype
, mem_ref_offset (t
));
3344 get_constraint_for_ptr_offset (TREE_OPERAND (t
, 0), off
, results
);
3347 /* If we are not taking the address then make sure to process
3348 all subvariables we might access. */
3349 cs
= *VEC_last (ce_s
, *results
);
3351 || cs
.type
!= SCALAR
)
3354 vi
= get_varinfo (cs
.var
);
3356 if (!vi
->is_full_var
3359 unsigned HOST_WIDE_INT size
;
3360 if (host_integerp (TYPE_SIZE (TREE_TYPE (t
)), 1))
3361 size
= TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (t
)));
3364 for (; curr
; curr
= curr
->next
)
3366 if (curr
->offset
- vi
->offset
< size
)
3369 VEC_safe_push (ce_s
, heap
, *results
, &cs
);
3378 case ARRAY_RANGE_REF
:
3380 get_constraint_for_component_ref (t
, results
, address_p
, lhs_p
);
3382 case VIEW_CONVERT_EXPR
:
3383 get_constraint_for_1 (TREE_OPERAND (t
, 0), results
, address_p
,
3386 /* We are missing handling for TARGET_MEM_REF here. */
3391 case tcc_exceptional
:
3393 switch (TREE_CODE (t
))
3397 get_constraint_for_ssa_var (t
, results
, address_p
);
3404 VEC (ce_s
, heap
) *tmp
= NULL
;
3405 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t
), i
, val
)
3407 struct constraint_expr
*rhsp
;
3409 get_constraint_for_1 (val
, &tmp
, address_p
, lhs_p
);
3410 FOR_EACH_VEC_ELT (ce_s
, tmp
, j
, rhsp
)
3411 VEC_safe_push (ce_s
, heap
, *results
, rhsp
);
3412 VEC_truncate (ce_s
, tmp
, 0);
3414 VEC_free (ce_s
, heap
, tmp
);
3415 /* We do not know whether the constructor was complete,
3416 so technically we have to add &NOTHING or &ANYTHING
3417 like we do for an empty constructor as well. */
3424 case tcc_declaration
:
3426 get_constraint_for_ssa_var (t
, results
, address_p
);
3431 /* We cannot refer to automatic variables through constants. */
3432 temp
.type
= ADDRESSOF
;
3433 temp
.var
= nonlocal_id
;
3435 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3441 /* The default fallback is a constraint from anything. */
3442 temp
.type
= ADDRESSOF
;
3443 temp
.var
= anything_id
;
3445 VEC_safe_push (ce_s
, heap
, *results
, &temp
);
3448 /* Given a gimple tree T, return the constraint expression vector for it. */
3451 get_constraint_for (tree t
, VEC (ce_s
, heap
) **results
)
3453 gcc_assert (VEC_length (ce_s
, *results
) == 0);
3455 get_constraint_for_1 (t
, results
, false, true);
3458 /* Given a gimple tree T, return the constraint expression vector for it
3459 to be used as the rhs of a constraint. */
3462 get_constraint_for_rhs (tree t
, VEC (ce_s
, heap
) **results
)
3464 gcc_assert (VEC_length (ce_s
, *results
) == 0);
3466 get_constraint_for_1 (t
, results
, false, false);
3470 /* Efficiently generates constraints from all entries in *RHSC to all
3471 entries in *LHSC. */
3474 process_all_all_constraints (VEC (ce_s
, heap
) *lhsc
, VEC (ce_s
, heap
) *rhsc
)
3476 struct constraint_expr
*lhsp
, *rhsp
;
3479 if (VEC_length (ce_s
, lhsc
) <= 1
3480 || VEC_length (ce_s
, rhsc
) <= 1)
3482 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
3483 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, rhsp
)
3484 process_constraint (new_constraint (*lhsp
, *rhsp
));
3488 struct constraint_expr tmp
;
3489 tmp
= new_scalar_tmp_constraint_exp ("allalltmp");
3490 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
3491 process_constraint (new_constraint (tmp
, *rhsp
));
3492 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
3493 process_constraint (new_constraint (*lhsp
, tmp
));
3497 /* Handle aggregate copies by expanding into copies of the respective
3498 fields of the structures. */
3501 do_structure_copy (tree lhsop
, tree rhsop
)
3503 struct constraint_expr
*lhsp
, *rhsp
;
3504 VEC (ce_s
, heap
) *lhsc
= NULL
, *rhsc
= NULL
;
3507 get_constraint_for (lhsop
, &lhsc
);
3508 get_constraint_for_rhs (rhsop
, &rhsc
);
3509 lhsp
= VEC_index (ce_s
, lhsc
, 0);
3510 rhsp
= VEC_index (ce_s
, rhsc
, 0);
3511 if (lhsp
->type
== DEREF
3512 || (lhsp
->type
== ADDRESSOF
&& lhsp
->var
== anything_id
)
3513 || rhsp
->type
== DEREF
)
3515 if (lhsp
->type
== DEREF
)
3517 gcc_assert (VEC_length (ce_s
, lhsc
) == 1);
3518 lhsp
->offset
= UNKNOWN_OFFSET
;
3520 if (rhsp
->type
== DEREF
)
3522 gcc_assert (VEC_length (ce_s
, rhsc
) == 1);
3523 rhsp
->offset
= UNKNOWN_OFFSET
;
3525 process_all_all_constraints (lhsc
, rhsc
);
3527 else if (lhsp
->type
== SCALAR
3528 && (rhsp
->type
== SCALAR
3529 || rhsp
->type
== ADDRESSOF
))
3531 HOST_WIDE_INT lhssize
, lhsmaxsize
, lhsoffset
;
3532 HOST_WIDE_INT rhssize
, rhsmaxsize
, rhsoffset
;
3534 get_ref_base_and_extent (lhsop
, &lhsoffset
, &lhssize
, &lhsmaxsize
);
3535 get_ref_base_and_extent (rhsop
, &rhsoffset
, &rhssize
, &rhsmaxsize
);
3536 for (j
= 0; VEC_iterate (ce_s
, lhsc
, j
, lhsp
);)
3538 varinfo_t lhsv
, rhsv
;
3539 rhsp
= VEC_index (ce_s
, rhsc
, k
);
3540 lhsv
= get_varinfo (lhsp
->var
);
3541 rhsv
= get_varinfo (rhsp
->var
);
3542 if (lhsv
->may_have_pointers
3543 && (lhsv
->is_full_var
3544 || rhsv
->is_full_var
3545 || ranges_overlap_p (lhsv
->offset
+ rhsoffset
, lhsv
->size
,
3546 rhsv
->offset
+ lhsoffset
, rhsv
->size
)))
3547 process_constraint (new_constraint (*lhsp
, *rhsp
));
3548 if (!rhsv
->is_full_var
3549 && (lhsv
->is_full_var
3550 || (lhsv
->offset
+ rhsoffset
+ lhsv
->size
3551 > rhsv
->offset
+ lhsoffset
+ rhsv
->size
)))
3554 if (k
>= VEC_length (ce_s
, rhsc
))
3564 VEC_free (ce_s
, heap
, lhsc
);
3565 VEC_free (ce_s
, heap
, rhsc
);
3568 /* Create constraints ID = { rhsc }. */
3571 make_constraints_to (unsigned id
, VEC(ce_s
, heap
) *rhsc
)
3573 struct constraint_expr
*c
;
3574 struct constraint_expr includes
;
3578 includes
.offset
= 0;
3579 includes
.type
= SCALAR
;
3581 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, c
)
3582 process_constraint (new_constraint (includes
, *c
));
3585 /* Create a constraint ID = OP. */
3588 make_constraint_to (unsigned id
, tree op
)
3590 VEC(ce_s
, heap
) *rhsc
= NULL
;
3591 get_constraint_for_rhs (op
, &rhsc
);
3592 make_constraints_to (id
, rhsc
);
3593 VEC_free (ce_s
, heap
, rhsc
);
3596 /* Create a constraint ID = &FROM. */
3599 make_constraint_from (varinfo_t vi
, int from
)
3601 struct constraint_expr lhs
, rhs
;
3609 rhs
.type
= ADDRESSOF
;
3610 process_constraint (new_constraint (lhs
, rhs
));
3613 /* Create a constraint ID = FROM. */
3616 make_copy_constraint (varinfo_t vi
, int from
)
3618 struct constraint_expr lhs
, rhs
;
3627 process_constraint (new_constraint (lhs
, rhs
));
3630 /* Make constraints necessary to make OP escape. */
3633 make_escape_constraint (tree op
)
3635 make_constraint_to (escaped_id
, op
);
3638 /* Add constraints to that the solution of VI is transitively closed. */
3641 make_transitive_closure_constraints (varinfo_t vi
)
3643 struct constraint_expr lhs
, rhs
;
3652 process_constraint (new_constraint (lhs
, rhs
));
3654 /* VAR = VAR + UNKNOWN; */
3660 rhs
.offset
= UNKNOWN_OFFSET
;
3661 process_constraint (new_constraint (lhs
, rhs
));
3664 /* Create a new artificial heap variable with NAME.
3665 Return the created variable. */
3668 make_heapvar_for (varinfo_t lhs
, const char *name
)
3671 tree heapvar
= heapvar_lookup (lhs
->decl
, lhs
->offset
);
3673 if (heapvar
== NULL_TREE
)
3676 heapvar
= create_tmp_var_raw (ptr_type_node
, name
);
3677 DECL_EXTERNAL (heapvar
) = 1;
3679 heapvar_insert (lhs
->decl
, lhs
->offset
, heapvar
);
3681 ann
= get_var_ann (heapvar
);
3682 ann
->is_heapvar
= 1;
3685 /* For global vars we need to add a heapvar to the list of referenced
3686 vars of a different function than it was created for originally. */
3687 if (cfun
&& gimple_referenced_vars (cfun
))
3688 add_referenced_var (heapvar
);
3690 vi
= new_var_info (heapvar
, name
);
3691 vi
->is_artificial_var
= true;
3692 vi
->is_heap_var
= true;
3693 vi
->is_unknown_size_var
= true;
3697 vi
->is_full_var
= true;
3698 insert_vi_for_tree (heapvar
, vi
);
3703 /* Create a new artificial heap variable with NAME and make a
3704 constraint from it to LHS. Return the created variable. */
3707 make_constraint_from_heapvar (varinfo_t lhs
, const char *name
)
3709 varinfo_t vi
= make_heapvar_for (lhs
, name
);
3710 make_constraint_from (lhs
, vi
->id
);
3715 /* Create a new artificial heap variable with NAME and make a
3716 constraint from it to LHS. Set flags according to a tag used
3717 for tracking restrict pointers. */
3720 make_constraint_from_restrict (varinfo_t lhs
, const char *name
)
3723 vi
= make_constraint_from_heapvar (lhs
, name
);
3724 vi
->is_restrict_var
= 1;
3725 vi
->is_global_var
= 0;
3726 vi
->is_special_var
= 1;
3727 vi
->may_have_pointers
= 0;
3730 /* In IPA mode there are varinfos for different aspects of reach
3731 function designator. One for the points-to set of the return
3732 value, one for the variables that are clobbered by the function,
3733 one for its uses and one for each parameter (including a single
3734 glob for remaining variadic arguments). */
3736 enum { fi_clobbers
= 1, fi_uses
= 2,
3737 fi_static_chain
= 3, fi_result
= 4, fi_parm_base
= 5 };
3739 /* Get a constraint for the requested part of a function designator FI
3740 when operating in IPA mode. */
3742 static struct constraint_expr
3743 get_function_part_constraint (varinfo_t fi
, unsigned part
)
3745 struct constraint_expr c
;
3747 gcc_assert (in_ipa_mode
);
3749 if (fi
->id
== anything_id
)
3751 /* ??? We probably should have a ANYFN special variable. */
3752 c
.var
= anything_id
;
3756 else if (TREE_CODE (fi
->decl
) == FUNCTION_DECL
)
3758 varinfo_t ai
= first_vi_for_offset (fi
, part
);
3762 c
.var
= anything_id
;
3776 /* For non-IPA mode, generate constraints necessary for a call on the
3780 handle_rhs_call (gimple stmt
, VEC(ce_s
, heap
) **results
)
3782 struct constraint_expr rhsc
;
3784 bool returns_uses
= false;
3786 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
3788 tree arg
= gimple_call_arg (stmt
, i
);
3789 int flags
= gimple_call_arg_flags (stmt
, i
);
3791 /* If the argument is not used we can ignore it. */
3792 if (flags
& EAF_UNUSED
)
3795 /* As we compute ESCAPED context-insensitive we do not gain
3796 any precision with just EAF_NOCLOBBER but not EAF_NOESCAPE
3797 set. The argument would still get clobbered through the
3799 ??? We might get away with less (and more precise) constraints
3800 if using a temporary for transitively closing things. */
3801 if ((flags
& EAF_NOCLOBBER
)
3802 && (flags
& EAF_NOESCAPE
))
3804 varinfo_t uses
= get_call_use_vi (stmt
);
3805 if (!(flags
& EAF_DIRECT
))
3806 make_transitive_closure_constraints (uses
);
3807 make_constraint_to (uses
->id
, arg
);
3808 returns_uses
= true;
3810 else if (flags
& EAF_NOESCAPE
)
3812 varinfo_t uses
= get_call_use_vi (stmt
);
3813 varinfo_t clobbers
= get_call_clobber_vi (stmt
);
3814 if (!(flags
& EAF_DIRECT
))
3816 make_transitive_closure_constraints (uses
);
3817 make_transitive_closure_constraints (clobbers
);
3819 make_constraint_to (uses
->id
, arg
);
3820 make_constraint_to (clobbers
->id
, arg
);
3821 returns_uses
= true;
3824 make_escape_constraint (arg
);
3827 /* If we added to the calls uses solution make sure we account for
3828 pointers to it to be returned. */
3831 rhsc
.var
= get_call_use_vi (stmt
)->id
;
3834 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3837 /* The static chain escapes as well. */
3838 if (gimple_call_chain (stmt
))
3839 make_escape_constraint (gimple_call_chain (stmt
));
3841 /* And if we applied NRV the address of the return slot escapes as well. */
3842 if (gimple_call_return_slot_opt_p (stmt
)
3843 && gimple_call_lhs (stmt
) != NULL_TREE
3844 && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt
))))
3846 VEC(ce_s
, heap
) *tmpc
= NULL
;
3847 struct constraint_expr lhsc
, *c
;
3848 get_constraint_for_address_of (gimple_call_lhs (stmt
), &tmpc
);
3849 lhsc
.var
= escaped_id
;
3852 FOR_EACH_VEC_ELT (ce_s
, tmpc
, i
, c
)
3853 process_constraint (new_constraint (lhsc
, *c
));
3854 VEC_free(ce_s
, heap
, tmpc
);
3857 /* Regular functions return nonlocal memory. */
3858 rhsc
.var
= nonlocal_id
;
3861 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3864 /* For non-IPA mode, generate constraints necessary for a call
3865 that returns a pointer and assigns it to LHS. This simply makes
3866 the LHS point to global and escaped variables. */
3869 handle_lhs_call (gimple stmt
, tree lhs
, int flags
, VEC(ce_s
, heap
) *rhsc
,
3872 VEC(ce_s
, heap
) *lhsc
= NULL
;
3874 get_constraint_for (lhs
, &lhsc
);
3875 /* If the store is to a global decl make sure to
3876 add proper escape constraints. */
3877 lhs
= get_base_address (lhs
);
3880 && is_global_var (lhs
))
3882 struct constraint_expr tmpc
;
3883 tmpc
.var
= escaped_id
;
3886 VEC_safe_push (ce_s
, heap
, lhsc
, &tmpc
);
3889 /* If the call returns an argument unmodified override the rhs
3891 flags
= gimple_call_return_flags (stmt
);
3892 if (flags
& ERF_RETURNS_ARG
3893 && (flags
& ERF_RETURN_ARG_MASK
) < gimple_call_num_args (stmt
))
3897 arg
= gimple_call_arg (stmt
, flags
& ERF_RETURN_ARG_MASK
);
3898 get_constraint_for (arg
, &rhsc
);
3899 process_all_all_constraints (lhsc
, rhsc
);
3900 VEC_free (ce_s
, heap
, rhsc
);
3902 else if (flags
& ERF_NOALIAS
)
3905 struct constraint_expr tmpc
;
3907 vi
= make_heapvar_for (get_vi_for_tree (lhs
), "HEAP");
3908 /* We delay marking allocated storage global until we know if
3910 DECL_EXTERNAL (vi
->decl
) = 0;
3911 vi
->is_global_var
= 0;
3912 /* If this is not a real malloc call assume the memory was
3913 initialized and thus may point to global memory. All
3914 builtin functions with the malloc attribute behave in a sane way. */
3916 || DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_NORMAL
)
3917 make_constraint_from (vi
, nonlocal_id
);
3920 tmpc
.type
= ADDRESSOF
;
3921 VEC_safe_push (ce_s
, heap
, rhsc
, &tmpc
);
3924 process_all_all_constraints (lhsc
, rhsc
);
3926 VEC_free (ce_s
, heap
, lhsc
);
3929 /* For non-IPA mode, generate constraints necessary for a call of a
3930 const function that returns a pointer in the statement STMT. */
3933 handle_const_call (gimple stmt
, VEC(ce_s
, heap
) **results
)
3935 struct constraint_expr rhsc
;
3938 /* Treat nested const functions the same as pure functions as far
3939 as the static chain is concerned. */
3940 if (gimple_call_chain (stmt
))
3942 varinfo_t uses
= get_call_use_vi (stmt
);
3943 make_transitive_closure_constraints (uses
);
3944 make_constraint_to (uses
->id
, gimple_call_chain (stmt
));
3945 rhsc
.var
= uses
->id
;
3948 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3951 /* May return arguments. */
3952 for (k
= 0; k
< gimple_call_num_args (stmt
); ++k
)
3954 tree arg
= gimple_call_arg (stmt
, k
);
3955 VEC(ce_s
, heap
) *argc
= NULL
;
3957 struct constraint_expr
*argp
;
3958 get_constraint_for_rhs (arg
, &argc
);
3959 FOR_EACH_VEC_ELT (ce_s
, argc
, i
, argp
)
3960 VEC_safe_push (ce_s
, heap
, *results
, argp
);
3961 VEC_free(ce_s
, heap
, argc
);
3964 /* May return addresses of globals. */
3965 rhsc
.var
= nonlocal_id
;
3967 rhsc
.type
= ADDRESSOF
;
3968 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
3971 /* For non-IPA mode, generate constraints necessary for a call to a
3972 pure function in statement STMT. */
3975 handle_pure_call (gimple stmt
, VEC(ce_s
, heap
) **results
)
3977 struct constraint_expr rhsc
;
3979 varinfo_t uses
= NULL
;
3981 /* Memory reached from pointer arguments is call-used. */
3982 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
3984 tree arg
= gimple_call_arg (stmt
, i
);
3987 uses
= get_call_use_vi (stmt
);
3988 make_transitive_closure_constraints (uses
);
3990 make_constraint_to (uses
->id
, arg
);
3993 /* The static chain is used as well. */
3994 if (gimple_call_chain (stmt
))
3998 uses
= get_call_use_vi (stmt
);
3999 make_transitive_closure_constraints (uses
);
4001 make_constraint_to (uses
->id
, gimple_call_chain (stmt
));
4004 /* Pure functions may return call-used and nonlocal memory. */
4007 rhsc
.var
= uses
->id
;
4010 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
4012 rhsc
.var
= nonlocal_id
;
4015 VEC_safe_push (ce_s
, heap
, *results
, &rhsc
);
4019 /* Return the varinfo for the callee of CALL. */
4022 get_fi_for_callee (gimple call
)
4026 /* If we can directly resolve the function being called, do so.
4027 Otherwise, it must be some sort of indirect expression that
4028 we should still be able to handle. */
4029 decl
= gimple_call_fndecl (call
);
4031 return get_vi_for_tree (decl
);
4033 decl
= gimple_call_fn (call
);
4034 /* The function can be either an SSA name pointer or,
4035 worse, an OBJ_TYPE_REF. In this case we have no
4036 clue and should be getting ANYFN (well, ANYTHING for now). */
4037 if (TREE_CODE (decl
) == SSA_NAME
)
4039 if (TREE_CODE (decl
) == SSA_NAME
4040 && (TREE_CODE (SSA_NAME_VAR (decl
)) == PARM_DECL
4041 || TREE_CODE (SSA_NAME_VAR (decl
)) == RESULT_DECL
)
4042 && SSA_NAME_IS_DEFAULT_DEF (decl
))
4043 decl
= SSA_NAME_VAR (decl
);
4044 return get_vi_for_tree (decl
);
4046 else if (TREE_CODE (decl
) == INTEGER_CST
4047 || TREE_CODE (decl
) == OBJ_TYPE_REF
)
4048 return get_varinfo (anything_id
);
4053 /* Walk statement T setting up aliasing constraints according to the
4054 references found in T. This function is the main part of the
4055 constraint builder. AI points to auxiliary alias information used
4056 when building alias sets and computing alias grouping heuristics. */
4059 find_func_aliases (gimple origt
)
4062 VEC(ce_s
, heap
) *lhsc
= NULL
;
4063 VEC(ce_s
, heap
) *rhsc
= NULL
;
4064 struct constraint_expr
*c
;
4067 /* Now build constraints expressions. */
4068 if (gimple_code (t
) == GIMPLE_PHI
)
4073 /* For a phi node, assign all the arguments to
4075 get_constraint_for (gimple_phi_result (t
), &lhsc
);
4076 for (i
= 0; i
< gimple_phi_num_args (t
); i
++)
4078 tree strippedrhs
= PHI_ARG_DEF (t
, i
);
4080 STRIP_NOPS (strippedrhs
);
4081 get_constraint_for_rhs (gimple_phi_arg_def (t
, i
), &rhsc
);
4083 FOR_EACH_VEC_ELT (ce_s
, lhsc
, j
, c
)
4085 struct constraint_expr
*c2
;
4086 while (VEC_length (ce_s
, rhsc
) > 0)
4088 c2
= VEC_last (ce_s
, rhsc
);
4089 process_constraint (new_constraint (*c
, *c2
));
4090 VEC_pop (ce_s
, rhsc
);
4095 /* In IPA mode, we need to generate constraints to pass call
4096 arguments through their calls. There are two cases,
4097 either a GIMPLE_CALL returning a value, or just a plain
4098 GIMPLE_CALL when we are not.
4100 In non-ipa mode, we need to generate constraints for each
4101 pointer passed by address. */
4102 else if (is_gimple_call (t
))
4104 tree fndecl
= gimple_call_fndecl (t
);
4105 if (fndecl
!= NULL_TREE
4106 && DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
4107 /* ??? All builtins that are handled here need to be handled
4108 in the alias-oracle query functions explicitly! */
4109 switch (DECL_FUNCTION_CODE (fndecl
))
4111 /* All the following functions return a pointer to the same object
4112 as their first argument points to. The functions do not add
4113 to the ESCAPED solution. The functions make the first argument
4114 pointed to memory point to what the second argument pointed to
4115 memory points to. */
4116 case BUILT_IN_STRCPY
:
4117 case BUILT_IN_STRNCPY
:
4118 case BUILT_IN_BCOPY
:
4119 case BUILT_IN_MEMCPY
:
4120 case BUILT_IN_MEMMOVE
:
4121 case BUILT_IN_MEMPCPY
:
4122 case BUILT_IN_STPCPY
:
4123 case BUILT_IN_STPNCPY
:
4124 case BUILT_IN_STRCAT
:
4125 case BUILT_IN_STRNCAT
:
4127 tree res
= gimple_call_lhs (t
);
4128 tree dest
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (fndecl
)
4129 == BUILT_IN_BCOPY
? 1 : 0));
4130 tree src
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (fndecl
)
4131 == BUILT_IN_BCOPY
? 0 : 1));
4132 if (res
!= NULL_TREE
)
4134 get_constraint_for (res
, &lhsc
);
4135 if (DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_MEMPCPY
4136 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPCPY
4137 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPNCPY
)
4138 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &rhsc
);
4140 get_constraint_for (dest
, &rhsc
);
4141 process_all_all_constraints (lhsc
, rhsc
);
4142 VEC_free (ce_s
, heap
, lhsc
);
4143 VEC_free (ce_s
, heap
, rhsc
);
4145 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4146 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4149 process_all_all_constraints (lhsc
, rhsc
);
4150 VEC_free (ce_s
, heap
, lhsc
);
4151 VEC_free (ce_s
, heap
, rhsc
);
4154 case BUILT_IN_MEMSET
:
4156 tree res
= gimple_call_lhs (t
);
4157 tree dest
= gimple_call_arg (t
, 0);
4160 struct constraint_expr ac
;
4161 if (res
!= NULL_TREE
)
4163 get_constraint_for (res
, &lhsc
);
4164 get_constraint_for (dest
, &rhsc
);
4165 process_all_all_constraints (lhsc
, rhsc
);
4166 VEC_free (ce_s
, heap
, lhsc
);
4167 VEC_free (ce_s
, heap
, rhsc
);
4169 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4171 if (flag_delete_null_pointer_checks
4172 && integer_zerop (gimple_call_arg (t
, 1)))
4174 ac
.type
= ADDRESSOF
;
4175 ac
.var
= nothing_id
;
4180 ac
.var
= integer_id
;
4183 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
4184 process_constraint (new_constraint (*lhsp
, ac
));
4185 VEC_free (ce_s
, heap
, lhsc
);
4188 /* All the following functions do not return pointers, do not
4189 modify the points-to sets of memory reachable from their
4190 arguments and do not add to the ESCAPED solution. */
4191 case BUILT_IN_SINCOS
:
4192 case BUILT_IN_SINCOSF
:
4193 case BUILT_IN_SINCOSL
:
4194 case BUILT_IN_FREXP
:
4195 case BUILT_IN_FREXPF
:
4196 case BUILT_IN_FREXPL
:
4197 case BUILT_IN_GAMMA_R
:
4198 case BUILT_IN_GAMMAF_R
:
4199 case BUILT_IN_GAMMAL_R
:
4200 case BUILT_IN_LGAMMA_R
:
4201 case BUILT_IN_LGAMMAF_R
:
4202 case BUILT_IN_LGAMMAL_R
:
4204 case BUILT_IN_MODFF
:
4205 case BUILT_IN_MODFL
:
4206 case BUILT_IN_REMQUO
:
4207 case BUILT_IN_REMQUOF
:
4208 case BUILT_IN_REMQUOL
:
4211 /* Trampolines are special - they set up passing the static
4213 case BUILT_IN_INIT_TRAMPOLINE
:
4215 tree tramp
= gimple_call_arg (t
, 0);
4216 tree nfunc
= gimple_call_arg (t
, 1);
4217 tree frame
= gimple_call_arg (t
, 2);
4219 struct constraint_expr lhs
, *rhsp
;
4222 varinfo_t nfi
= NULL
;
4223 gcc_assert (TREE_CODE (nfunc
) == ADDR_EXPR
);
4224 nfi
= lookup_vi_for_tree (TREE_OPERAND (nfunc
, 0));
4227 lhs
= get_function_part_constraint (nfi
, fi_static_chain
);
4228 get_constraint_for (frame
, &rhsc
);
4229 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4230 process_constraint (new_constraint (lhs
, *rhsp
));
4231 VEC_free (ce_s
, heap
, rhsc
);
4233 /* Make the frame point to the function for
4234 the trampoline adjustment call. */
4235 get_constraint_for (tramp
, &lhsc
);
4237 get_constraint_for (nfunc
, &rhsc
);
4238 process_all_all_constraints (lhsc
, rhsc
);
4239 VEC_free (ce_s
, heap
, rhsc
);
4240 VEC_free (ce_s
, heap
, lhsc
);
4245 /* Else fallthru to generic handling which will let
4246 the frame escape. */
4249 case BUILT_IN_ADJUST_TRAMPOLINE
:
4251 tree tramp
= gimple_call_arg (t
, 0);
4252 tree res
= gimple_call_lhs (t
);
4253 if (in_ipa_mode
&& res
)
4255 get_constraint_for (res
, &lhsc
);
4256 get_constraint_for (tramp
, &rhsc
);
4258 process_all_all_constraints (lhsc
, rhsc
);
4259 VEC_free (ce_s
, heap
, rhsc
);
4260 VEC_free (ce_s
, heap
, lhsc
);
4264 /* Variadic argument handling needs to be handled in IPA
4266 case BUILT_IN_VA_START
:
4270 tree valist
= gimple_call_arg (t
, 0);
4271 struct constraint_expr rhs
, *lhsp
;
4273 /* The va_list gets access to pointers in variadic
4275 fi
= lookup_vi_for_tree (cfun
->decl
);
4276 gcc_assert (fi
!= NULL
);
4277 get_constraint_for (valist
, &lhsc
);
4279 rhs
= get_function_part_constraint (fi
, ~0);
4280 rhs
.type
= ADDRESSOF
;
4281 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
4282 process_constraint (new_constraint (*lhsp
, rhs
));
4283 VEC_free (ce_s
, heap
, lhsc
);
4284 /* va_list is clobbered. */
4285 make_constraint_to (get_call_clobber_vi (t
)->id
, valist
);
4290 /* va_end doesn't have any effect that matters. */
4291 case BUILT_IN_VA_END
:
4293 /* Alternate return. Simply give up for now. */
4294 case BUILT_IN_RETURN
:
4298 || !(fi
= get_vi_for_tree (cfun
->decl
)))
4299 make_constraint_from (get_varinfo (escaped_id
), anything_id
);
4300 else if (in_ipa_mode
4303 struct constraint_expr lhs
, rhs
;
4304 lhs
= get_function_part_constraint (fi
, fi_result
);
4305 rhs
.var
= anything_id
;
4308 process_constraint (new_constraint (lhs
, rhs
));
4312 /* printf-style functions may have hooks to set pointers to
4313 point to somewhere into the generated string. Leave them
4314 for a later excercise... */
4316 /* Fallthru to general call handling. */;
4320 && (!(fi
= lookup_vi_for_tree (fndecl
))
4321 || !fi
->is_fn_info
)))
4323 VEC(ce_s
, heap
) *rhsc
= NULL
;
4324 int flags
= gimple_call_flags (t
);
4326 /* Const functions can return their arguments and addresses
4327 of global memory but not of escaped memory. */
4328 if (flags
& (ECF_CONST
|ECF_NOVOPS
))
4330 if (gimple_call_lhs (t
))
4331 handle_const_call (t
, &rhsc
);
4333 /* Pure functions can return addresses in and of memory
4334 reachable from their arguments, but they are not an escape
4335 point for reachable memory of their arguments. */
4336 else if (flags
& (ECF_PURE
|ECF_LOOPING_CONST_OR_PURE
))
4337 handle_pure_call (t
, &rhsc
);
4339 handle_rhs_call (t
, &rhsc
);
4340 if (gimple_call_lhs (t
))
4341 handle_lhs_call (t
, gimple_call_lhs (t
), flags
, rhsc
, fndecl
);
4342 VEC_free (ce_s
, heap
, rhsc
);
4349 fi
= get_fi_for_callee (t
);
4351 /* Assign all the passed arguments to the appropriate incoming
4352 parameters of the function. */
4353 for (j
= 0; j
< gimple_call_num_args (t
); j
++)
4355 struct constraint_expr lhs
;
4356 struct constraint_expr
*rhsp
;
4357 tree arg
= gimple_call_arg (t
, j
);
4359 get_constraint_for_rhs (arg
, &rhsc
);
4360 lhs
= get_function_part_constraint (fi
, fi_parm_base
+ j
);
4361 while (VEC_length (ce_s
, rhsc
) != 0)
4363 rhsp
= VEC_last (ce_s
, rhsc
);
4364 process_constraint (new_constraint (lhs
, *rhsp
));
4365 VEC_pop (ce_s
, rhsc
);
4369 /* If we are returning a value, assign it to the result. */
4370 lhsop
= gimple_call_lhs (t
);
4373 struct constraint_expr rhs
;
4374 struct constraint_expr
*lhsp
;
4376 get_constraint_for (lhsop
, &lhsc
);
4377 rhs
= get_function_part_constraint (fi
, fi_result
);
4379 && DECL_RESULT (fndecl
)
4380 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
4382 VEC(ce_s
, heap
) *tem
= NULL
;
4383 VEC_safe_push (ce_s
, heap
, tem
, &rhs
);
4385 rhs
= *VEC_index (ce_s
, tem
, 0);
4386 VEC_free(ce_s
, heap
, tem
);
4388 FOR_EACH_VEC_ELT (ce_s
, lhsc
, j
, lhsp
)
4389 process_constraint (new_constraint (*lhsp
, rhs
));
4392 /* If we pass the result decl by reference, honor that. */
4395 && DECL_RESULT (fndecl
)
4396 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
4398 struct constraint_expr lhs
;
4399 struct constraint_expr
*rhsp
;
4401 get_constraint_for_address_of (lhsop
, &rhsc
);
4402 lhs
= get_function_part_constraint (fi
, fi_result
);
4403 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, rhsp
)
4404 process_constraint (new_constraint (lhs
, *rhsp
));
4405 VEC_free (ce_s
, heap
, rhsc
);
4408 /* If we use a static chain, pass it along. */
4409 if (gimple_call_chain (t
))
4411 struct constraint_expr lhs
;
4412 struct constraint_expr
*rhsp
;
4414 get_constraint_for (gimple_call_chain (t
), &rhsc
);
4415 lhs
= get_function_part_constraint (fi
, fi_static_chain
);
4416 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, rhsp
)
4417 process_constraint (new_constraint (lhs
, *rhsp
));
4421 /* Otherwise, just a regular assignment statement. Only care about
4422 operations with pointer result, others are dealt with as escape
4423 points if they have pointer operands. */
4424 else if (is_gimple_assign (t
))
4426 /* Otherwise, just a regular assignment statement. */
4427 tree lhsop
= gimple_assign_lhs (t
);
4428 tree rhsop
= (gimple_num_ops (t
) == 2) ? gimple_assign_rhs1 (t
) : NULL
;
4430 if (rhsop
&& AGGREGATE_TYPE_P (TREE_TYPE (lhsop
)))
4431 do_structure_copy (lhsop
, rhsop
);
4434 get_constraint_for (lhsop
, &lhsc
);
4436 if (gimple_assign_rhs_code (t
) == POINTER_PLUS_EXPR
)
4437 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t
),
4438 gimple_assign_rhs2 (t
), &rhsc
);
4439 else if (gimple_assign_rhs_code (t
) == BIT_AND_EXPR
4440 && TREE_CODE (gimple_assign_rhs2 (t
)) == INTEGER_CST
)
4442 /* Aligning a pointer via a BIT_AND_EXPR is offsetting
4443 the pointer. Handle it by offsetting it by UNKNOWN. */
4444 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t
),
4447 else if ((CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (t
))
4448 && !(POINTER_TYPE_P (gimple_expr_type (t
))
4449 && !POINTER_TYPE_P (TREE_TYPE (rhsop
))))
4450 || gimple_assign_single_p (t
))
4451 get_constraint_for_rhs (rhsop
, &rhsc
);
4454 /* All other operations are merges. */
4455 VEC (ce_s
, heap
) *tmp
= NULL
;
4456 struct constraint_expr
*rhsp
;
4458 get_constraint_for_rhs (gimple_assign_rhs1 (t
), &rhsc
);
4459 for (i
= 2; i
< gimple_num_ops (t
); ++i
)
4461 get_constraint_for_rhs (gimple_op (t
, i
), &tmp
);
4462 FOR_EACH_VEC_ELT (ce_s
, tmp
, j
, rhsp
)
4463 VEC_safe_push (ce_s
, heap
, rhsc
, rhsp
);
4464 VEC_truncate (ce_s
, tmp
, 0);
4466 VEC_free (ce_s
, heap
, tmp
);
4468 process_all_all_constraints (lhsc
, rhsc
);
4470 /* If there is a store to a global variable the rhs escapes. */
4471 if ((lhsop
= get_base_address (lhsop
)) != NULL_TREE
4473 && is_global_var (lhsop
)
4475 || DECL_EXTERNAL (lhsop
) || TREE_PUBLIC (lhsop
)))
4476 make_escape_constraint (rhsop
);
4477 /* If this is a conversion of a non-restrict pointer to a
4478 restrict pointer track it with a new heapvar. */
4479 else if (gimple_assign_cast_p (t
)
4480 && POINTER_TYPE_P (TREE_TYPE (rhsop
))
4481 && POINTER_TYPE_P (TREE_TYPE (lhsop
))
4482 && !TYPE_RESTRICT (TREE_TYPE (rhsop
))
4483 && TYPE_RESTRICT (TREE_TYPE (lhsop
)))
4484 make_constraint_from_restrict (get_vi_for_tree (lhsop
),
4487 /* Handle escapes through return. */
4488 else if (gimple_code (t
) == GIMPLE_RETURN
4489 && gimple_return_retval (t
) != NULL_TREE
)
4493 || !(fi
= get_vi_for_tree (cfun
->decl
)))
4494 make_escape_constraint (gimple_return_retval (t
));
4495 else if (in_ipa_mode
4498 struct constraint_expr lhs
;
4499 struct constraint_expr
*rhsp
;
4502 lhs
= get_function_part_constraint (fi
, fi_result
);
4503 get_constraint_for_rhs (gimple_return_retval (t
), &rhsc
);
4504 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4505 process_constraint (new_constraint (lhs
, *rhsp
));
4508 /* Handle asms conservatively by adding escape constraints to everything. */
4509 else if (gimple_code (t
) == GIMPLE_ASM
)
4511 unsigned i
, noutputs
;
4512 const char **oconstraints
;
4513 const char *constraint
;
4514 bool allows_mem
, allows_reg
, is_inout
;
4516 noutputs
= gimple_asm_noutputs (t
);
4517 oconstraints
= XALLOCAVEC (const char *, noutputs
);
4519 for (i
= 0; i
< noutputs
; ++i
)
4521 tree link
= gimple_asm_output_op (t
, i
);
4522 tree op
= TREE_VALUE (link
);
4524 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
4525 oconstraints
[i
] = constraint
;
4526 parse_output_constraint (&constraint
, i
, 0, 0, &allows_mem
,
4527 &allows_reg
, &is_inout
);
4529 /* A memory constraint makes the address of the operand escape. */
4530 if (!allows_reg
&& allows_mem
)
4531 make_escape_constraint (build_fold_addr_expr (op
));
4533 /* The asm may read global memory, so outputs may point to
4534 any global memory. */
4537 VEC(ce_s
, heap
) *lhsc
= NULL
;
4538 struct constraint_expr rhsc
, *lhsp
;
4540 get_constraint_for (op
, &lhsc
);
4541 rhsc
.var
= nonlocal_id
;
4544 FOR_EACH_VEC_ELT (ce_s
, lhsc
, j
, lhsp
)
4545 process_constraint (new_constraint (*lhsp
, rhsc
));
4546 VEC_free (ce_s
, heap
, lhsc
);
4549 for (i
= 0; i
< gimple_asm_ninputs (t
); ++i
)
4551 tree link
= gimple_asm_input_op (t
, i
);
4552 tree op
= TREE_VALUE (link
);
4554 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
4556 parse_input_constraint (&constraint
, 0, 0, noutputs
, 0, oconstraints
,
4557 &allows_mem
, &allows_reg
);
4559 /* A memory constraint makes the address of the operand escape. */
4560 if (!allows_reg
&& allows_mem
)
4561 make_escape_constraint (build_fold_addr_expr (op
));
4562 /* Strictly we'd only need the constraint to ESCAPED if
4563 the asm clobbers memory, otherwise using something
4564 along the lines of per-call clobbers/uses would be enough. */
4566 make_escape_constraint (op
);
4570 VEC_free (ce_s
, heap
, rhsc
);
4571 VEC_free (ce_s
, heap
, lhsc
);
4575 /* Create a constraint adding to the clobber set of FI the memory
4576 pointed to by PTR. */
4579 process_ipa_clobber (varinfo_t fi
, tree ptr
)
4581 VEC(ce_s
, heap
) *ptrc
= NULL
;
4582 struct constraint_expr
*c
, lhs
;
4584 get_constraint_for_rhs (ptr
, &ptrc
);
4585 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4586 FOR_EACH_VEC_ELT (ce_s
, ptrc
, i
, c
)
4587 process_constraint (new_constraint (lhs
, *c
));
4588 VEC_free (ce_s
, heap
, ptrc
);
4591 /* Walk statement T setting up clobber and use constraints according to the
4592 references found in T. This function is a main part of the
4593 IPA constraint builder. */
4596 find_func_clobbers (gimple origt
)
4599 VEC(ce_s
, heap
) *lhsc
= NULL
;
4600 VEC(ce_s
, heap
) *rhsc
= NULL
;
4603 /* Add constraints for clobbered/used in IPA mode.
4604 We are not interested in what automatic variables are clobbered
4605 or used as we only use the information in the caller to which
4606 they do not escape. */
4607 gcc_assert (in_ipa_mode
);
4609 /* If the stmt refers to memory in any way it better had a VUSE. */
4610 if (gimple_vuse (t
) == NULL_TREE
)
4613 /* We'd better have function information for the current function. */
4614 fi
= lookup_vi_for_tree (cfun
->decl
);
4615 gcc_assert (fi
!= NULL
);
4617 /* Account for stores in assignments and calls. */
4618 if (gimple_vdef (t
) != NULL_TREE
4619 && gimple_has_lhs (t
))
4621 tree lhs
= gimple_get_lhs (t
);
4623 while (handled_component_p (tem
))
4624 tem
= TREE_OPERAND (tem
, 0);
4626 && !auto_var_in_fn_p (tem
, cfun
->decl
))
4627 || INDIRECT_REF_P (tem
)
4628 || (TREE_CODE (tem
) == MEM_REF
4629 && !(TREE_CODE (TREE_OPERAND (tem
, 0)) == ADDR_EXPR
4631 (TREE_OPERAND (TREE_OPERAND (tem
, 0), 0), cfun
->decl
))))
4633 struct constraint_expr lhsc
, *rhsp
;
4635 lhsc
= get_function_part_constraint (fi
, fi_clobbers
);
4636 get_constraint_for_address_of (lhs
, &rhsc
);
4637 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4638 process_constraint (new_constraint (lhsc
, *rhsp
));
4639 VEC_free (ce_s
, heap
, rhsc
);
4643 /* Account for uses in assigments and returns. */
4644 if (gimple_assign_single_p (t
)
4645 || (gimple_code (t
) == GIMPLE_RETURN
4646 && gimple_return_retval (t
) != NULL_TREE
))
4648 tree rhs
= (gimple_assign_single_p (t
)
4649 ? gimple_assign_rhs1 (t
) : gimple_return_retval (t
));
4651 while (handled_component_p (tem
))
4652 tem
= TREE_OPERAND (tem
, 0);
4654 && !auto_var_in_fn_p (tem
, cfun
->decl
))
4655 || INDIRECT_REF_P (tem
)
4656 || (TREE_CODE (tem
) == MEM_REF
4657 && !(TREE_CODE (TREE_OPERAND (tem
, 0)) == ADDR_EXPR
4659 (TREE_OPERAND (TREE_OPERAND (tem
, 0), 0), cfun
->decl
))))
4661 struct constraint_expr lhs
, *rhsp
;
4663 lhs
= get_function_part_constraint (fi
, fi_uses
);
4664 get_constraint_for_address_of (rhs
, &rhsc
);
4665 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4666 process_constraint (new_constraint (lhs
, *rhsp
));
4667 VEC_free (ce_s
, heap
, rhsc
);
4671 if (is_gimple_call (t
))
4673 varinfo_t cfi
= NULL
;
4674 tree decl
= gimple_call_fndecl (t
);
4675 struct constraint_expr lhs
, rhs
;
4678 /* For builtins we do not have separate function info. For those
4679 we do not generate escapes for we have to generate clobbers/uses. */
4681 && DECL_BUILT_IN_CLASS (decl
) == BUILT_IN_NORMAL
)
4682 switch (DECL_FUNCTION_CODE (decl
))
4684 /* The following functions use and clobber memory pointed to
4685 by their arguments. */
4686 case BUILT_IN_STRCPY
:
4687 case BUILT_IN_STRNCPY
:
4688 case BUILT_IN_BCOPY
:
4689 case BUILT_IN_MEMCPY
:
4690 case BUILT_IN_MEMMOVE
:
4691 case BUILT_IN_MEMPCPY
:
4692 case BUILT_IN_STPCPY
:
4693 case BUILT_IN_STPNCPY
:
4694 case BUILT_IN_STRCAT
:
4695 case BUILT_IN_STRNCAT
:
4697 tree dest
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (decl
)
4698 == BUILT_IN_BCOPY
? 1 : 0));
4699 tree src
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (decl
)
4700 == BUILT_IN_BCOPY
? 0 : 1));
4702 struct constraint_expr
*rhsp
, *lhsp
;
4703 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4704 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4705 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
4706 process_constraint (new_constraint (lhs
, *lhsp
));
4707 VEC_free (ce_s
, heap
, lhsc
);
4708 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4709 lhs
= get_function_part_constraint (fi
, fi_uses
);
4710 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
4711 process_constraint (new_constraint (lhs
, *rhsp
));
4712 VEC_free (ce_s
, heap
, rhsc
);
4715 /* The following function clobbers memory pointed to by
4717 case BUILT_IN_MEMSET
:
4719 tree dest
= gimple_call_arg (t
, 0);
4722 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4723 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4724 FOR_EACH_VEC_ELT (ce_s
, lhsc
, i
, lhsp
)
4725 process_constraint (new_constraint (lhs
, *lhsp
));
4726 VEC_free (ce_s
, heap
, lhsc
);
4729 /* The following functions clobber their second and third
4731 case BUILT_IN_SINCOS
:
4732 case BUILT_IN_SINCOSF
:
4733 case BUILT_IN_SINCOSL
:
4735 process_ipa_clobber (fi
, gimple_call_arg (t
, 1));
4736 process_ipa_clobber (fi
, gimple_call_arg (t
, 2));
4739 /* The following functions clobber their second argument. */
4740 case BUILT_IN_FREXP
:
4741 case BUILT_IN_FREXPF
:
4742 case BUILT_IN_FREXPL
:
4743 case BUILT_IN_LGAMMA_R
:
4744 case BUILT_IN_LGAMMAF_R
:
4745 case BUILT_IN_LGAMMAL_R
:
4746 case BUILT_IN_GAMMA_R
:
4747 case BUILT_IN_GAMMAF_R
:
4748 case BUILT_IN_GAMMAL_R
:
4750 case BUILT_IN_MODFF
:
4751 case BUILT_IN_MODFL
:
4753 process_ipa_clobber (fi
, gimple_call_arg (t
, 1));
4756 /* The following functions clobber their third argument. */
4757 case BUILT_IN_REMQUO
:
4758 case BUILT_IN_REMQUOF
:
4759 case BUILT_IN_REMQUOL
:
4761 process_ipa_clobber (fi
, gimple_call_arg (t
, 2));
4764 /* The following functions neither read nor clobber memory. */
4767 /* Trampolines are of no interest to us. */
4768 case BUILT_IN_INIT_TRAMPOLINE
:
4769 case BUILT_IN_ADJUST_TRAMPOLINE
:
4771 case BUILT_IN_VA_START
:
4772 case BUILT_IN_VA_END
:
4774 /* printf-style functions may have hooks to set pointers to
4775 point to somewhere into the generated string. Leave them
4776 for a later excercise... */
4778 /* Fallthru to general call handling. */;
4781 /* Parameters passed by value are used. */
4782 lhs
= get_function_part_constraint (fi
, fi_uses
);
4783 for (i
= 0; i
< gimple_call_num_args (t
); i
++)
4785 struct constraint_expr
*rhsp
;
4786 tree arg
= gimple_call_arg (t
, i
);
4788 if (TREE_CODE (arg
) == SSA_NAME
4789 || is_gimple_min_invariant (arg
))
4792 get_constraint_for_address_of (arg
, &rhsc
);
4793 FOR_EACH_VEC_ELT (ce_s
, rhsc
, j
, rhsp
)
4794 process_constraint (new_constraint (lhs
, *rhsp
));
4795 VEC_free (ce_s
, heap
, rhsc
);
4798 /* Build constraints for propagating clobbers/uses along the
4800 cfi
= get_fi_for_callee (t
);
4801 if (cfi
->id
== anything_id
)
4803 if (gimple_vdef (t
))
4804 make_constraint_from (first_vi_for_offset (fi
, fi_clobbers
),
4806 make_constraint_from (first_vi_for_offset (fi
, fi_uses
),
4811 /* For callees without function info (that's external functions),
4812 ESCAPED is clobbered and used. */
4813 if (gimple_call_fndecl (t
)
4814 && !cfi
->is_fn_info
)
4818 if (gimple_vdef (t
))
4819 make_copy_constraint (first_vi_for_offset (fi
, fi_clobbers
),
4821 make_copy_constraint (first_vi_for_offset (fi
, fi_uses
), escaped_id
);
4823 /* Also honor the call statement use/clobber info. */
4824 if ((vi
= lookup_call_clobber_vi (t
)) != NULL
)
4825 make_copy_constraint (first_vi_for_offset (fi
, fi_clobbers
),
4827 if ((vi
= lookup_call_use_vi (t
)) != NULL
)
4828 make_copy_constraint (first_vi_for_offset (fi
, fi_uses
),
4833 /* Otherwise the caller clobbers and uses what the callee does.
4834 ??? This should use a new complex constraint that filters
4835 local variables of the callee. */
4836 if (gimple_vdef (t
))
4838 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4839 rhs
= get_function_part_constraint (cfi
, fi_clobbers
);
4840 process_constraint (new_constraint (lhs
, rhs
));
4842 lhs
= get_function_part_constraint (fi
, fi_uses
);
4843 rhs
= get_function_part_constraint (cfi
, fi_uses
);
4844 process_constraint (new_constraint (lhs
, rhs
));
4846 else if (gimple_code (t
) == GIMPLE_ASM
)
4848 /* ??? Ick. We can do better. */
4849 if (gimple_vdef (t
))
4850 make_constraint_from (first_vi_for_offset (fi
, fi_clobbers
),
4852 make_constraint_from (first_vi_for_offset (fi
, fi_uses
),
4856 VEC_free (ce_s
, heap
, rhsc
);
4860 /* Find the first varinfo in the same variable as START that overlaps with
4861 OFFSET. Return NULL if we can't find one. */
4864 first_vi_for_offset (varinfo_t start
, unsigned HOST_WIDE_INT offset
)
4866 /* If the offset is outside of the variable, bail out. */
4867 if (offset
>= start
->fullsize
)
4870 /* If we cannot reach offset from start, lookup the first field
4871 and start from there. */
4872 if (start
->offset
> offset
)
4873 start
= lookup_vi_for_tree (start
->decl
);
4877 /* We may not find a variable in the field list with the actual
4878 offset when when we have glommed a structure to a variable.
4879 In that case, however, offset should still be within the size
4881 if (offset
>= start
->offset
4882 && (offset
- start
->offset
) < start
->size
)
4891 /* Find the first varinfo in the same variable as START that overlaps with
4892 OFFSET. If there is no such varinfo the varinfo directly preceding
4893 OFFSET is returned. */
4896 first_or_preceding_vi_for_offset (varinfo_t start
,
4897 unsigned HOST_WIDE_INT offset
)
4899 /* If we cannot reach offset from start, lookup the first field
4900 and start from there. */
4901 if (start
->offset
> offset
)
4902 start
= lookup_vi_for_tree (start
->decl
);
4904 /* We may not find a variable in the field list with the actual
4905 offset when when we have glommed a structure to a variable.
4906 In that case, however, offset should still be within the size
4908 If we got beyond the offset we look for return the field
4909 directly preceding offset which may be the last field. */
4911 && offset
>= start
->offset
4912 && !((offset
- start
->offset
) < start
->size
))
4913 start
= start
->next
;
4919 /* This structure is used during pushing fields onto the fieldstack
4920 to track the offset of the field, since bitpos_of_field gives it
4921 relative to its immediate containing type, and we want it relative
4922 to the ultimate containing object. */
4926 /* Offset from the base of the base containing object to this field. */
4927 HOST_WIDE_INT offset
;
4929 /* Size, in bits, of the field. */
4930 unsigned HOST_WIDE_INT size
;
4932 unsigned has_unknown_size
: 1;
4934 unsigned must_have_pointers
: 1;
4936 unsigned may_have_pointers
: 1;
4938 unsigned only_restrict_pointers
: 1;
4940 typedef struct fieldoff fieldoff_s
;
4942 DEF_VEC_O(fieldoff_s
);
4943 DEF_VEC_ALLOC_O(fieldoff_s
,heap
);
4945 /* qsort comparison function for two fieldoff's PA and PB */
4948 fieldoff_compare (const void *pa
, const void *pb
)
4950 const fieldoff_s
*foa
= (const fieldoff_s
*)pa
;
4951 const fieldoff_s
*fob
= (const fieldoff_s
*)pb
;
4952 unsigned HOST_WIDE_INT foasize
, fobsize
;
4954 if (foa
->offset
< fob
->offset
)
4956 else if (foa
->offset
> fob
->offset
)
4959 foasize
= foa
->size
;
4960 fobsize
= fob
->size
;
4961 if (foasize
< fobsize
)
4963 else if (foasize
> fobsize
)
4968 /* Sort a fieldstack according to the field offset and sizes. */
4970 sort_fieldstack (VEC(fieldoff_s
,heap
) *fieldstack
)
4972 VEC_qsort (fieldoff_s
, fieldstack
, fieldoff_compare
);
4975 /* Return true if V is a tree that we can have subvars for.
4976 Normally, this is any aggregate type. Also complex
4977 types which are not gimple registers can have subvars. */
4980 var_can_have_subvars (const_tree v
)
4982 /* Volatile variables should never have subvars. */
4983 if (TREE_THIS_VOLATILE (v
))
4986 /* Non decls or memory tags can never have subvars. */
4990 /* Aggregates without overlapping fields can have subvars. */
4991 if (TREE_CODE (TREE_TYPE (v
)) == RECORD_TYPE
)
4997 /* Return true if T is a type that does contain pointers. */
5000 type_must_have_pointers (tree type
)
5002 if (POINTER_TYPE_P (type
))
5005 if (TREE_CODE (type
) == ARRAY_TYPE
)
5006 return type_must_have_pointers (TREE_TYPE (type
));
5008 /* A function or method can have pointers as arguments, so track
5009 those separately. */
5010 if (TREE_CODE (type
) == FUNCTION_TYPE
5011 || TREE_CODE (type
) == METHOD_TYPE
)
5018 field_must_have_pointers (tree t
)
5020 return type_must_have_pointers (TREE_TYPE (t
));
5023 /* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
5024 the fields of TYPE onto fieldstack, recording their offsets along
5027 OFFSET is used to keep track of the offset in this entire
5028 structure, rather than just the immediately containing structure.
5029 Returns false if the caller is supposed to handle the field we
5033 push_fields_onto_fieldstack (tree type
, VEC(fieldoff_s
,heap
) **fieldstack
,
5034 HOST_WIDE_INT offset
)
5037 bool empty_p
= true;
5039 if (TREE_CODE (type
) != RECORD_TYPE
)
5042 /* If the vector of fields is growing too big, bail out early.
5043 Callers check for VEC_length <= MAX_FIELDS_FOR_FIELD_SENSITIVE, make
5045 if (VEC_length (fieldoff_s
, *fieldstack
) > MAX_FIELDS_FOR_FIELD_SENSITIVE
)
5048 for (field
= TYPE_FIELDS (type
); field
; field
= DECL_CHAIN (field
))
5049 if (TREE_CODE (field
) == FIELD_DECL
)
5052 HOST_WIDE_INT foff
= bitpos_of_field (field
);
5054 if (!var_can_have_subvars (field
)
5055 || TREE_CODE (TREE_TYPE (field
)) == QUAL_UNION_TYPE
5056 || TREE_CODE (TREE_TYPE (field
)) == UNION_TYPE
)
5058 else if (!push_fields_onto_fieldstack
5059 (TREE_TYPE (field
), fieldstack
, offset
+ foff
)
5060 && (DECL_SIZE (field
)
5061 && !integer_zerop (DECL_SIZE (field
))))
5062 /* Empty structures may have actual size, like in C++. So
5063 see if we didn't push any subfields and the size is
5064 nonzero, push the field onto the stack. */
5069 fieldoff_s
*pair
= NULL
;
5070 bool has_unknown_size
= false;
5071 bool must_have_pointers_p
;
5073 if (!VEC_empty (fieldoff_s
, *fieldstack
))
5074 pair
= VEC_last (fieldoff_s
, *fieldstack
);
5076 if (!DECL_SIZE (field
)
5077 || !host_integerp (DECL_SIZE (field
), 1))
5078 has_unknown_size
= true;
5080 /* If adjacent fields do not contain pointers merge them. */
5081 must_have_pointers_p
= field_must_have_pointers (field
);
5083 && !has_unknown_size
5084 && !must_have_pointers_p
5085 && !pair
->must_have_pointers
5086 && !pair
->has_unknown_size
5087 && pair
->offset
+ (HOST_WIDE_INT
)pair
->size
== offset
+ foff
)
5089 pair
->size
+= TREE_INT_CST_LOW (DECL_SIZE (field
));
5093 pair
= VEC_safe_push (fieldoff_s
, heap
, *fieldstack
, NULL
);
5094 pair
->offset
= offset
+ foff
;
5095 pair
->has_unknown_size
= has_unknown_size
;
5096 if (!has_unknown_size
)
5097 pair
->size
= TREE_INT_CST_LOW (DECL_SIZE (field
));
5100 pair
->must_have_pointers
= must_have_pointers_p
;
5101 pair
->may_have_pointers
= true;
5102 pair
->only_restrict_pointers
5103 = (!has_unknown_size
5104 && POINTER_TYPE_P (TREE_TYPE (field
))
5105 && TYPE_RESTRICT (TREE_TYPE (field
)));
5115 /* Count the number of arguments DECL has, and set IS_VARARGS to true
5116 if it is a varargs function. */
5119 count_num_arguments (tree decl
, bool *is_varargs
)
5121 unsigned int num
= 0;
5124 /* Capture named arguments for K&R functions. They do not
5125 have a prototype and thus no TYPE_ARG_TYPES. */
5126 for (t
= DECL_ARGUMENTS (decl
); t
; t
= DECL_CHAIN (t
))
5129 /* Check if the function has variadic arguments. */
5130 for (t
= TYPE_ARG_TYPES (TREE_TYPE (decl
)); t
; t
= TREE_CHAIN (t
))
5131 if (TREE_VALUE (t
) == void_type_node
)
5139 /* Creation function node for DECL, using NAME, and return the index
5140 of the variable we've created for the function. */
5143 create_function_info_for (tree decl
, const char *name
)
5145 struct function
*fn
= DECL_STRUCT_FUNCTION (decl
);
5146 varinfo_t vi
, prev_vi
;
5149 bool is_varargs
= false;
5150 unsigned int num_args
= count_num_arguments (decl
, &is_varargs
);
5152 /* Create the variable info. */
5154 vi
= new_var_info (decl
, name
);
5157 vi
->fullsize
= fi_parm_base
+ num_args
;
5159 vi
->may_have_pointers
= false;
5162 insert_vi_for_tree (vi
->decl
, vi
);
5166 /* Create a variable for things the function clobbers and one for
5167 things the function uses. */
5169 varinfo_t clobbervi
, usevi
;
5170 const char *newname
;
5173 asprintf (&tempname
, "%s.clobber", name
);
5174 newname
= ggc_strdup (tempname
);
5177 clobbervi
= new_var_info (NULL
, newname
);
5178 clobbervi
->offset
= fi_clobbers
;
5179 clobbervi
->size
= 1;
5180 clobbervi
->fullsize
= vi
->fullsize
;
5181 clobbervi
->is_full_var
= true;
5182 clobbervi
->is_global_var
= false;
5183 gcc_assert (prev_vi
->offset
< clobbervi
->offset
);
5184 prev_vi
->next
= clobbervi
;
5185 prev_vi
= clobbervi
;
5187 asprintf (&tempname
, "%s.use", name
);
5188 newname
= ggc_strdup (tempname
);
5191 usevi
= new_var_info (NULL
, newname
);
5192 usevi
->offset
= fi_uses
;
5194 usevi
->fullsize
= vi
->fullsize
;
5195 usevi
->is_full_var
= true;
5196 usevi
->is_global_var
= false;
5197 gcc_assert (prev_vi
->offset
< usevi
->offset
);
5198 prev_vi
->next
= usevi
;
5202 /* And one for the static chain. */
5203 if (fn
->static_chain_decl
!= NULL_TREE
)
5206 const char *newname
;
5209 asprintf (&tempname
, "%s.chain", name
);
5210 newname
= ggc_strdup (tempname
);
5213 chainvi
= new_var_info (fn
->static_chain_decl
, newname
);
5214 chainvi
->offset
= fi_static_chain
;
5216 chainvi
->fullsize
= vi
->fullsize
;
5217 chainvi
->is_full_var
= true;
5218 chainvi
->is_global_var
= false;
5219 gcc_assert (prev_vi
->offset
< chainvi
->offset
);
5220 prev_vi
->next
= chainvi
;
5222 insert_vi_for_tree (fn
->static_chain_decl
, chainvi
);
5225 /* Create a variable for the return var. */
5226 if (DECL_RESULT (decl
) != NULL
5227 || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl
))))
5230 const char *newname
;
5232 tree resultdecl
= decl
;
5234 if (DECL_RESULT (decl
))
5235 resultdecl
= DECL_RESULT (decl
);
5237 asprintf (&tempname
, "%s.result", name
);
5238 newname
= ggc_strdup (tempname
);
5241 resultvi
= new_var_info (resultdecl
, newname
);
5242 resultvi
->offset
= fi_result
;
5244 resultvi
->fullsize
= vi
->fullsize
;
5245 resultvi
->is_full_var
= true;
5246 if (DECL_RESULT (decl
))
5247 resultvi
->may_have_pointers
= true;
5248 gcc_assert (prev_vi
->offset
< resultvi
->offset
);
5249 prev_vi
->next
= resultvi
;
5251 if (DECL_RESULT (decl
))
5252 insert_vi_for_tree (DECL_RESULT (decl
), resultvi
);
5255 /* Set up variables for each argument. */
5256 arg
= DECL_ARGUMENTS (decl
);
5257 for (i
= 0; i
< num_args
; i
++)
5260 const char *newname
;
5262 tree argdecl
= decl
;
5267 asprintf (&tempname
, "%s.arg%d", name
, i
);
5268 newname
= ggc_strdup (tempname
);
5271 argvi
= new_var_info (argdecl
, newname
);
5272 argvi
->offset
= fi_parm_base
+ i
;
5274 argvi
->is_full_var
= true;
5275 argvi
->fullsize
= vi
->fullsize
;
5277 argvi
->may_have_pointers
= true;
5278 gcc_assert (prev_vi
->offset
< argvi
->offset
);
5279 prev_vi
->next
= argvi
;
5283 insert_vi_for_tree (arg
, argvi
);
5284 arg
= DECL_CHAIN (arg
);
5288 /* Add one representative for all further args. */
5292 const char *newname
;
5296 asprintf (&tempname
, "%s.varargs", name
);
5297 newname
= ggc_strdup (tempname
);
5300 /* We need sth that can be pointed to for va_start. */
5301 decl
= create_tmp_var_raw (ptr_type_node
, name
);
5304 argvi
= new_var_info (decl
, newname
);
5305 argvi
->offset
= fi_parm_base
+ num_args
;
5307 argvi
->is_full_var
= true;
5308 argvi
->is_heap_var
= true;
5309 argvi
->fullsize
= vi
->fullsize
;
5310 gcc_assert (prev_vi
->offset
< argvi
->offset
);
5311 prev_vi
->next
= argvi
;
5319 /* Return true if FIELDSTACK contains fields that overlap.
5320 FIELDSTACK is assumed to be sorted by offset. */
5323 check_for_overlaps (VEC (fieldoff_s
,heap
) *fieldstack
)
5325 fieldoff_s
*fo
= NULL
;
5327 HOST_WIDE_INT lastoffset
= -1;
5329 FOR_EACH_VEC_ELT (fieldoff_s
, fieldstack
, i
, fo
)
5331 if (fo
->offset
== lastoffset
)
5333 lastoffset
= fo
->offset
;
5338 /* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
5339 This will also create any varinfo structures necessary for fields
5343 create_variable_info_for_1 (tree decl
, const char *name
)
5345 varinfo_t vi
, newvi
;
5346 tree decl_type
= TREE_TYPE (decl
);
5347 tree declsize
= DECL_P (decl
) ? DECL_SIZE (decl
) : TYPE_SIZE (decl_type
);
5348 VEC (fieldoff_s
,heap
) *fieldstack
= NULL
;
5353 || !host_integerp (declsize
, 1))
5355 vi
= new_var_info (decl
, name
);
5359 vi
->is_unknown_size_var
= true;
5360 vi
->is_full_var
= true;
5361 vi
->may_have_pointers
= true;
5365 /* Collect field information. */
5366 if (use_field_sensitive
5367 && var_can_have_subvars (decl
)
5368 /* ??? Force us to not use subfields for global initializers
5369 in IPA mode. Else we'd have to parse arbitrary initializers. */
5371 && is_global_var (decl
)
5372 && DECL_INITIAL (decl
)))
5374 fieldoff_s
*fo
= NULL
;
5375 bool notokay
= false;
5378 push_fields_onto_fieldstack (decl_type
, &fieldstack
, 0);
5380 for (i
= 0; !notokay
&& VEC_iterate (fieldoff_s
, fieldstack
, i
, fo
); i
++)
5381 if (fo
->has_unknown_size
5388 /* We can't sort them if we have a field with a variable sized type,
5389 which will make notokay = true. In that case, we are going to return
5390 without creating varinfos for the fields anyway, so sorting them is a
5394 sort_fieldstack (fieldstack
);
5395 /* Due to some C++ FE issues, like PR 22488, we might end up
5396 what appear to be overlapping fields even though they,
5397 in reality, do not overlap. Until the C++ FE is fixed,
5398 we will simply disable field-sensitivity for these cases. */
5399 notokay
= check_for_overlaps (fieldstack
);
5403 VEC_free (fieldoff_s
, heap
, fieldstack
);
5406 /* If we didn't end up collecting sub-variables create a full
5407 variable for the decl. */
5408 if (VEC_length (fieldoff_s
, fieldstack
) <= 1
5409 || VEC_length (fieldoff_s
, fieldstack
) > MAX_FIELDS_FOR_FIELD_SENSITIVE
)
5411 vi
= new_var_info (decl
, name
);
5413 vi
->may_have_pointers
= true;
5414 vi
->fullsize
= TREE_INT_CST_LOW (declsize
);
5415 vi
->size
= vi
->fullsize
;
5416 vi
->is_full_var
= true;
5417 VEC_free (fieldoff_s
, heap
, fieldstack
);
5421 vi
= new_var_info (decl
, name
);
5422 vi
->fullsize
= TREE_INT_CST_LOW (declsize
);
5423 for (i
= 0, newvi
= vi
;
5424 VEC_iterate (fieldoff_s
, fieldstack
, i
, fo
);
5425 ++i
, newvi
= newvi
->next
)
5427 const char *newname
= "NULL";
5432 asprintf (&tempname
, "%s." HOST_WIDE_INT_PRINT_DEC
5433 "+" HOST_WIDE_INT_PRINT_DEC
, name
, fo
->offset
, fo
->size
);
5434 newname
= ggc_strdup (tempname
);
5437 newvi
->name
= newname
;
5438 newvi
->offset
= fo
->offset
;
5439 newvi
->size
= fo
->size
;
5440 newvi
->fullsize
= vi
->fullsize
;
5441 newvi
->may_have_pointers
= fo
->may_have_pointers
;
5442 newvi
->only_restrict_pointers
= fo
->only_restrict_pointers
;
5443 if (i
+ 1 < VEC_length (fieldoff_s
, fieldstack
))
5444 newvi
->next
= new_var_info (decl
, name
);
5447 VEC_free (fieldoff_s
, heap
, fieldstack
);
5453 create_variable_info_for (tree decl
, const char *name
)
5455 varinfo_t vi
= create_variable_info_for_1 (decl
, name
);
5456 unsigned int id
= vi
->id
;
5458 insert_vi_for_tree (decl
, vi
);
5460 /* Create initial constraints for globals. */
5461 for (; vi
; vi
= vi
->next
)
5463 if (!vi
->may_have_pointers
5464 || !vi
->is_global_var
)
5467 /* Mark global restrict qualified pointers. */
5468 if ((POINTER_TYPE_P (TREE_TYPE (decl
))
5469 && TYPE_RESTRICT (TREE_TYPE (decl
)))
5470 || vi
->only_restrict_pointers
)
5471 make_constraint_from_restrict (vi
, "GLOBAL_RESTRICT");
5473 /* For escaped variables initialize them from nonlocal. */
5475 || DECL_EXTERNAL (decl
) || TREE_PUBLIC (decl
))
5476 make_copy_constraint (vi
, nonlocal_id
);
5478 /* If this is a global variable with an initializer and we are in
5479 IPA mode generate constraints for it. In non-IPA mode
5480 the initializer from nonlocal is all we need. */
5482 && DECL_INITIAL (decl
))
5484 VEC (ce_s
, heap
) *rhsc
= NULL
;
5485 struct constraint_expr lhs
, *rhsp
;
5487 get_constraint_for_rhs (DECL_INITIAL (decl
), &rhsc
);
5491 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
5492 process_constraint (new_constraint (lhs
, *rhsp
));
5493 /* If this is a variable that escapes from the unit
5494 the initializer escapes as well. */
5495 if (DECL_EXTERNAL (decl
) || TREE_PUBLIC (decl
))
5497 lhs
.var
= escaped_id
;
5500 FOR_EACH_VEC_ELT (ce_s
, rhsc
, i
, rhsp
)
5501 process_constraint (new_constraint (lhs
, *rhsp
));
5503 VEC_free (ce_s
, heap
, rhsc
);
5510 /* Print out the points-to solution for VAR to FILE. */
5513 dump_solution_for_var (FILE *file
, unsigned int var
)
5515 varinfo_t vi
= get_varinfo (var
);
5519 /* Dump the solution for unified vars anyway, this avoids difficulties
5520 in scanning dumps in the testsuite. */
5521 fprintf (file
, "%s = { ", vi
->name
);
5522 vi
= get_varinfo (find (var
));
5523 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, i
, bi
)
5524 fprintf (file
, "%s ", get_varinfo (i
)->name
);
5525 fprintf (file
, "}");
5527 /* But note when the variable was unified. */
5529 fprintf (file
, " same as %s", vi
->name
);
5531 fprintf (file
, "\n");
5534 /* Print the points-to solution for VAR to stdout. */
5537 debug_solution_for_var (unsigned int var
)
5539 dump_solution_for_var (stdout
, var
);
5542 /* Create varinfo structures for all of the variables in the
5543 function for intraprocedural mode. */
5546 intra_create_variable_infos (void)
5550 /* For each incoming pointer argument arg, create the constraint ARG
5551 = NONLOCAL or a dummy variable if it is a restrict qualified
5552 passed-by-reference argument. */
5553 for (t
= DECL_ARGUMENTS (current_function_decl
); t
; t
= DECL_CHAIN (t
))
5557 /* For restrict qualified pointers to objects passed by
5558 reference build a real representative for the pointed-to object. */
5559 if (DECL_BY_REFERENCE (t
)
5560 && POINTER_TYPE_P (TREE_TYPE (t
))
5561 && TYPE_RESTRICT (TREE_TYPE (t
)))
5563 struct constraint_expr lhsc
, rhsc
;
5565 tree heapvar
= heapvar_lookup (t
, 0);
5566 if (heapvar
== NULL_TREE
)
5569 heapvar
= create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t
)),
5571 DECL_EXTERNAL (heapvar
) = 1;
5572 heapvar_insert (t
, 0, heapvar
);
5573 ann
= get_var_ann (heapvar
);
5574 ann
->is_heapvar
= 1;
5576 if (gimple_referenced_vars (cfun
))
5577 add_referenced_var (heapvar
);
5578 lhsc
.var
= get_vi_for_tree (t
)->id
;
5581 rhsc
.var
= (vi
= get_vi_for_tree (heapvar
))->id
;
5582 rhsc
.type
= ADDRESSOF
;
5584 process_constraint (new_constraint (lhsc
, rhsc
));
5585 vi
->is_restrict_var
= 1;
5589 for (p
= get_vi_for_tree (t
); p
; p
= p
->next
)
5591 if (p
->may_have_pointers
)
5592 make_constraint_from (p
, nonlocal_id
);
5593 if (p
->only_restrict_pointers
)
5594 make_constraint_from_restrict (p
, "PARM_RESTRICT");
5596 if (POINTER_TYPE_P (TREE_TYPE (t
))
5597 && TYPE_RESTRICT (TREE_TYPE (t
)))
5598 make_constraint_from_restrict (get_vi_for_tree (t
), "PARM_RESTRICT");
5601 /* Add a constraint for a result decl that is passed by reference. */
5602 if (DECL_RESULT (cfun
->decl
)
5603 && DECL_BY_REFERENCE (DECL_RESULT (cfun
->decl
)))
5605 varinfo_t p
, result_vi
= get_vi_for_tree (DECL_RESULT (cfun
->decl
));
5607 for (p
= result_vi
; p
; p
= p
->next
)
5608 make_constraint_from (p
, nonlocal_id
);
5611 /* Add a constraint for the incoming static chain parameter. */
5612 if (cfun
->static_chain_decl
!= NULL_TREE
)
5614 varinfo_t p
, chain_vi
= get_vi_for_tree (cfun
->static_chain_decl
);
5616 for (p
= chain_vi
; p
; p
= p
->next
)
5617 make_constraint_from (p
, nonlocal_id
);
5621 /* Structure used to put solution bitmaps in a hashtable so they can
5622 be shared among variables with the same points-to set. */
5624 typedef struct shared_bitmap_info
5628 } *shared_bitmap_info_t
;
5629 typedef const struct shared_bitmap_info
*const_shared_bitmap_info_t
;
5631 static htab_t shared_bitmap_table
;
5633 /* Hash function for a shared_bitmap_info_t */
5636 shared_bitmap_hash (const void *p
)
5638 const_shared_bitmap_info_t
const bi
= (const_shared_bitmap_info_t
) p
;
5639 return bi
->hashcode
;
5642 /* Equality function for two shared_bitmap_info_t's. */
5645 shared_bitmap_eq (const void *p1
, const void *p2
)
5647 const_shared_bitmap_info_t
const sbi1
= (const_shared_bitmap_info_t
) p1
;
5648 const_shared_bitmap_info_t
const sbi2
= (const_shared_bitmap_info_t
) p2
;
5649 return bitmap_equal_p (sbi1
->pt_vars
, sbi2
->pt_vars
);
5652 /* Lookup a bitmap in the shared bitmap hashtable, and return an already
5653 existing instance if there is one, NULL otherwise. */
5656 shared_bitmap_lookup (bitmap pt_vars
)
5659 struct shared_bitmap_info sbi
;
5661 sbi
.pt_vars
= pt_vars
;
5662 sbi
.hashcode
= bitmap_hash (pt_vars
);
5664 slot
= htab_find_slot_with_hash (shared_bitmap_table
, &sbi
,
5665 sbi
.hashcode
, NO_INSERT
);
5669 return ((shared_bitmap_info_t
) *slot
)->pt_vars
;
5673 /* Add a bitmap to the shared bitmap hashtable. */
5676 shared_bitmap_add (bitmap pt_vars
)
5679 shared_bitmap_info_t sbi
= XNEW (struct shared_bitmap_info
);
5681 sbi
->pt_vars
= pt_vars
;
5682 sbi
->hashcode
= bitmap_hash (pt_vars
);
5684 slot
= htab_find_slot_with_hash (shared_bitmap_table
, sbi
,
5685 sbi
->hashcode
, INSERT
);
5686 gcc_assert (!*slot
);
5687 *slot
= (void *) sbi
;
5691 /* Set bits in INTO corresponding to the variable uids in solution set FROM. */
5694 set_uids_in_ptset (bitmap into
, bitmap from
, struct pt_solution
*pt
)
5699 EXECUTE_IF_SET_IN_BITMAP (from
, 0, i
, bi
)
5701 varinfo_t vi
= get_varinfo (i
);
5703 /* The only artificial variables that are allowed in a may-alias
5704 set are heap variables. */
5705 if (vi
->is_artificial_var
&& !vi
->is_heap_var
)
5708 if (TREE_CODE (vi
->decl
) == VAR_DECL
5709 || TREE_CODE (vi
->decl
) == PARM_DECL
5710 || TREE_CODE (vi
->decl
) == RESULT_DECL
)
5712 /* If we are in IPA mode we will not recompute points-to
5713 sets after inlining so make sure they stay valid. */
5715 && !DECL_PT_UID_SET_P (vi
->decl
))
5716 SET_DECL_PT_UID (vi
->decl
, DECL_UID (vi
->decl
));
5718 /* Add the decl to the points-to set. Note that the points-to
5719 set contains global variables. */
5720 bitmap_set_bit (into
, DECL_PT_UID (vi
->decl
));
5721 if (vi
->is_global_var
)
5722 pt
->vars_contains_global
= true;
5728 /* Compute the points-to solution *PT for the variable VI. */
5731 find_what_var_points_to (varinfo_t orig_vi
, struct pt_solution
*pt
)
5735 bitmap finished_solution
;
5739 memset (pt
, 0, sizeof (struct pt_solution
));
5741 /* This variable may have been collapsed, let's get the real
5743 vi
= get_varinfo (find (orig_vi
->id
));
5745 /* Translate artificial variables into SSA_NAME_PTR_INFO
5747 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, i
, bi
)
5749 varinfo_t vi
= get_varinfo (i
);
5751 if (vi
->is_artificial_var
)
5753 if (vi
->id
== nothing_id
)
5755 else if (vi
->id
== escaped_id
)
5758 pt
->ipa_escaped
= 1;
5762 else if (vi
->id
== nonlocal_id
)
5764 else if (vi
->is_heap_var
)
5765 /* We represent heapvars in the points-to set properly. */
5767 else if (vi
->id
== readonly_id
)
5770 else if (vi
->id
== anything_id
5771 || vi
->id
== integer_id
)
5774 if (vi
->is_restrict_var
)
5775 pt
->vars_contains_restrict
= true;
5778 /* Instead of doing extra work, simply do not create
5779 elaborate points-to information for pt_anything pointers. */
5781 && (orig_vi
->is_artificial_var
5782 || !pt
->vars_contains_restrict
))
5785 /* Share the final set of variables when possible. */
5786 finished_solution
= BITMAP_GGC_ALLOC ();
5787 stats
.points_to_sets_created
++;
5789 set_uids_in_ptset (finished_solution
, vi
->solution
, pt
);
5790 result
= shared_bitmap_lookup (finished_solution
);
5793 shared_bitmap_add (finished_solution
);
5794 pt
->vars
= finished_solution
;
5799 bitmap_clear (finished_solution
);
5803 /* Given a pointer variable P, fill in its points-to set. */
5806 find_what_p_points_to (tree p
)
5808 struct ptr_info_def
*pi
;
5812 /* For parameters, get at the points-to set for the actual parm
5814 if (TREE_CODE (p
) == SSA_NAME
5815 && (TREE_CODE (SSA_NAME_VAR (p
)) == PARM_DECL
5816 || TREE_CODE (SSA_NAME_VAR (p
)) == RESULT_DECL
)
5817 && SSA_NAME_IS_DEFAULT_DEF (p
))
5818 lookup_p
= SSA_NAME_VAR (p
);
5820 vi
= lookup_vi_for_tree (lookup_p
);
5824 pi
= get_ptr_info (p
);
5825 find_what_var_points_to (vi
, &pi
->pt
);
5829 /* Query statistics for points-to solutions. */
5832 unsigned HOST_WIDE_INT pt_solution_includes_may_alias
;
5833 unsigned HOST_WIDE_INT pt_solution_includes_no_alias
;
5834 unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias
;
5835 unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias
;
5839 dump_pta_stats (FILE *s
)
5841 fprintf (s
, "\nPTA query stats:\n");
5842 fprintf (s
, " pt_solution_includes: "
5843 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
5844 HOST_WIDE_INT_PRINT_DEC
" queries\n",
5845 pta_stats
.pt_solution_includes_no_alias
,
5846 pta_stats
.pt_solution_includes_no_alias
5847 + pta_stats
.pt_solution_includes_may_alias
);
5848 fprintf (s
, " pt_solutions_intersect: "
5849 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
5850 HOST_WIDE_INT_PRINT_DEC
" queries\n",
5851 pta_stats
.pt_solutions_intersect_no_alias
,
5852 pta_stats
.pt_solutions_intersect_no_alias
5853 + pta_stats
.pt_solutions_intersect_may_alias
);
5857 /* Reset the points-to solution *PT to a conservative default
5858 (point to anything). */
5861 pt_solution_reset (struct pt_solution
*pt
)
5863 memset (pt
, 0, sizeof (struct pt_solution
));
5864 pt
->anything
= true;
5867 /* Set the points-to solution *PT to point only to the variables
5868 in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
5869 global variables and VARS_CONTAINS_RESTRICT specifies whether
5870 it contains restrict tag variables. */
5873 pt_solution_set (struct pt_solution
*pt
, bitmap vars
,
5874 bool vars_contains_global
, bool vars_contains_restrict
)
5876 memset (pt
, 0, sizeof (struct pt_solution
));
5878 pt
->vars_contains_global
= vars_contains_global
;
5879 pt
->vars_contains_restrict
= vars_contains_restrict
;
5882 /* Set the points-to solution *PT to point only to the variable VAR. */
5885 pt_solution_set_var (struct pt_solution
*pt
, tree var
)
5887 memset (pt
, 0, sizeof (struct pt_solution
));
5888 pt
->vars
= BITMAP_GGC_ALLOC ();
5889 bitmap_set_bit (pt
->vars
, DECL_PT_UID (var
));
5890 pt
->vars_contains_global
= is_global_var (var
);
5893 /* Computes the union of the points-to solutions *DEST and *SRC and
5894 stores the result in *DEST. This changes the points-to bitmap
5895 of *DEST and thus may not be used if that might be shared.
5896 The points-to bitmap of *SRC and *DEST will not be shared after
5897 this function if they were not before. */
5900 pt_solution_ior_into (struct pt_solution
*dest
, struct pt_solution
*src
)
5902 dest
->anything
|= src
->anything
;
5905 pt_solution_reset (dest
);
5909 dest
->nonlocal
|= src
->nonlocal
;
5910 dest
->escaped
|= src
->escaped
;
5911 dest
->ipa_escaped
|= src
->ipa_escaped
;
5912 dest
->null
|= src
->null
;
5913 dest
->vars_contains_global
|= src
->vars_contains_global
;
5914 dest
->vars_contains_restrict
|= src
->vars_contains_restrict
;
5919 dest
->vars
= BITMAP_GGC_ALLOC ();
5920 bitmap_ior_into (dest
->vars
, src
->vars
);
5923 /* Return true if the points-to solution *PT is empty. */
5926 pt_solution_empty_p (struct pt_solution
*pt
)
5933 && !bitmap_empty_p (pt
->vars
))
5936 /* If the solution includes ESCAPED, check if that is empty. */
5938 && !pt_solution_empty_p (&cfun
->gimple_df
->escaped
))
5941 /* If the solution includes ESCAPED, check if that is empty. */
5943 && !pt_solution_empty_p (&ipa_escaped_pt
))
5949 /* Return true if the points-to solution *PT includes global memory. */
5952 pt_solution_includes_global (struct pt_solution
*pt
)
5956 || pt
->vars_contains_global
)
5960 return pt_solution_includes_global (&cfun
->gimple_df
->escaped
);
5962 if (pt
->ipa_escaped
)
5963 return pt_solution_includes_global (&ipa_escaped_pt
);
5965 /* ??? This predicate is not correct for the IPA-PTA solution
5966 as we do not properly distinguish between unit escape points
5967 and global variables. */
5968 if (cfun
->gimple_df
->ipa_pta
)
5974 /* Return true if the points-to solution *PT includes the variable
5975 declaration DECL. */
5978 pt_solution_includes_1 (struct pt_solution
*pt
, const_tree decl
)
5984 && is_global_var (decl
))
5988 && bitmap_bit_p (pt
->vars
, DECL_PT_UID (decl
)))
5991 /* If the solution includes ESCAPED, check it. */
5993 && pt_solution_includes_1 (&cfun
->gimple_df
->escaped
, decl
))
5996 /* If the solution includes ESCAPED, check it. */
5998 && pt_solution_includes_1 (&ipa_escaped_pt
, decl
))
6005 pt_solution_includes (struct pt_solution
*pt
, const_tree decl
)
6007 bool res
= pt_solution_includes_1 (pt
, decl
);
6009 ++pta_stats
.pt_solution_includes_may_alias
;
6011 ++pta_stats
.pt_solution_includes_no_alias
;
6015 /* Return true if both points-to solutions PT1 and PT2 have a non-empty
6019 pt_solutions_intersect_1 (struct pt_solution
*pt1
, struct pt_solution
*pt2
)
6021 if (pt1
->anything
|| pt2
->anything
)
6024 /* If either points to unknown global memory and the other points to
6025 any global memory they alias. */
6028 || pt2
->vars_contains_global
))
6030 && pt1
->vars_contains_global
))
6033 /* Check the escaped solution if required. */
6034 if ((pt1
->escaped
|| pt2
->escaped
)
6035 && !pt_solution_empty_p (&cfun
->gimple_df
->escaped
))
6037 /* If both point to escaped memory and that solution
6038 is not empty they alias. */
6039 if (pt1
->escaped
&& pt2
->escaped
)
6042 /* If either points to escaped memory see if the escaped solution
6043 intersects with the other. */
6045 && pt_solutions_intersect_1 (&cfun
->gimple_df
->escaped
, pt2
))
6047 && pt_solutions_intersect_1 (&cfun
->gimple_df
->escaped
, pt1
)))
6051 /* Check the escaped solution if required.
6052 ??? Do we need to check the local against the IPA escaped sets? */
6053 if ((pt1
->ipa_escaped
|| pt2
->ipa_escaped
)
6054 && !pt_solution_empty_p (&ipa_escaped_pt
))
6056 /* If both point to escaped memory and that solution
6057 is not empty they alias. */
6058 if (pt1
->ipa_escaped
&& pt2
->ipa_escaped
)
6061 /* If either points to escaped memory see if the escaped solution
6062 intersects with the other. */
6063 if ((pt1
->ipa_escaped
6064 && pt_solutions_intersect_1 (&ipa_escaped_pt
, pt2
))
6065 || (pt2
->ipa_escaped
6066 && pt_solutions_intersect_1 (&ipa_escaped_pt
, pt1
)))
6070 /* Now both pointers alias if their points-to solution intersects. */
6073 && bitmap_intersect_p (pt1
->vars
, pt2
->vars
));
6077 pt_solutions_intersect (struct pt_solution
*pt1
, struct pt_solution
*pt2
)
6079 bool res
= pt_solutions_intersect_1 (pt1
, pt2
);
6081 ++pta_stats
.pt_solutions_intersect_may_alias
;
6083 ++pta_stats
.pt_solutions_intersect_no_alias
;
6087 /* Return true if both points-to solutions PT1 and PT2 for two restrict
6088 qualified pointers are possibly based on the same pointer. */
6091 pt_solutions_same_restrict_base (struct pt_solution
*pt1
,
6092 struct pt_solution
*pt2
)
6094 /* If we deal with points-to solutions of two restrict qualified
6095 pointers solely rely on the pointed-to variable bitmap intersection.
6096 For two pointers that are based on each other the bitmaps will
6098 if (pt1
->vars_contains_restrict
6099 && pt2
->vars_contains_restrict
)
6101 gcc_assert (pt1
->vars
&& pt2
->vars
);
6102 return bitmap_intersect_p (pt1
->vars
, pt2
->vars
);
6109 /* Dump points-to information to OUTFILE. */
6112 dump_sa_points_to_info (FILE *outfile
)
6116 fprintf (outfile
, "\nPoints-to sets\n\n");
6118 if (dump_flags
& TDF_STATS
)
6120 fprintf (outfile
, "Stats:\n");
6121 fprintf (outfile
, "Total vars: %d\n", stats
.total_vars
);
6122 fprintf (outfile
, "Non-pointer vars: %d\n",
6123 stats
.nonpointer_vars
);
6124 fprintf (outfile
, "Statically unified vars: %d\n",
6125 stats
.unified_vars_static
);
6126 fprintf (outfile
, "Dynamically unified vars: %d\n",
6127 stats
.unified_vars_dynamic
);
6128 fprintf (outfile
, "Iterations: %d\n", stats
.iterations
);
6129 fprintf (outfile
, "Number of edges: %d\n", stats
.num_edges
);
6130 fprintf (outfile
, "Number of implicit edges: %d\n",
6131 stats
.num_implicit_edges
);
6134 for (i
= 0; i
< VEC_length (varinfo_t
, varmap
); i
++)
6136 varinfo_t vi
= get_varinfo (i
);
6137 if (!vi
->may_have_pointers
)
6139 dump_solution_for_var (outfile
, i
);
6144 /* Debug points-to information to stderr. */
6147 debug_sa_points_to_info (void)
6149 dump_sa_points_to_info (stderr
);
6153 /* Initialize the always-existing constraint variables for NULL
6154 ANYTHING, READONLY, and INTEGER */
6157 init_base_vars (void)
6159 struct constraint_expr lhs
, rhs
;
6160 varinfo_t var_anything
;
6161 varinfo_t var_nothing
;
6162 varinfo_t var_readonly
;
6163 varinfo_t var_escaped
;
6164 varinfo_t var_nonlocal
;
6165 varinfo_t var_storedanything
;
6166 varinfo_t var_integer
;
6168 /* Create the NULL variable, used to represent that a variable points
6170 var_nothing
= new_var_info (NULL_TREE
, "NULL");
6171 gcc_assert (var_nothing
->id
== nothing_id
);
6172 var_nothing
->is_artificial_var
= 1;
6173 var_nothing
->offset
= 0;
6174 var_nothing
->size
= ~0;
6175 var_nothing
->fullsize
= ~0;
6176 var_nothing
->is_special_var
= 1;
6177 var_nothing
->may_have_pointers
= 0;
6178 var_nothing
->is_global_var
= 0;
6180 /* Create the ANYTHING variable, used to represent that a variable
6181 points to some unknown piece of memory. */
6182 var_anything
= new_var_info (NULL_TREE
, "ANYTHING");
6183 gcc_assert (var_anything
->id
== anything_id
);
6184 var_anything
->is_artificial_var
= 1;
6185 var_anything
->size
= ~0;
6186 var_anything
->offset
= 0;
6187 var_anything
->next
= NULL
;
6188 var_anything
->fullsize
= ~0;
6189 var_anything
->is_special_var
= 1;
6191 /* Anything points to anything. This makes deref constraints just
6192 work in the presence of linked list and other p = *p type loops,
6193 by saying that *ANYTHING = ANYTHING. */
6195 lhs
.var
= anything_id
;
6197 rhs
.type
= ADDRESSOF
;
6198 rhs
.var
= anything_id
;
6201 /* This specifically does not use process_constraint because
6202 process_constraint ignores all anything = anything constraints, since all
6203 but this one are redundant. */
6204 VEC_safe_push (constraint_t
, heap
, constraints
, new_constraint (lhs
, rhs
));
6206 /* Create the READONLY variable, used to represent that a variable
6207 points to readonly memory. */
6208 var_readonly
= new_var_info (NULL_TREE
, "READONLY");
6209 gcc_assert (var_readonly
->id
== readonly_id
);
6210 var_readonly
->is_artificial_var
= 1;
6211 var_readonly
->offset
= 0;
6212 var_readonly
->size
= ~0;
6213 var_readonly
->fullsize
= ~0;
6214 var_readonly
->next
= NULL
;
6215 var_readonly
->is_special_var
= 1;
6217 /* readonly memory points to anything, in order to make deref
6218 easier. In reality, it points to anything the particular
6219 readonly variable can point to, but we don't track this
6222 lhs
.var
= readonly_id
;
6224 rhs
.type
= ADDRESSOF
;
6225 rhs
.var
= readonly_id
; /* FIXME */
6227 process_constraint (new_constraint (lhs
, rhs
));
6229 /* Create the ESCAPED variable, used to represent the set of escaped
6231 var_escaped
= new_var_info (NULL_TREE
, "ESCAPED");
6232 gcc_assert (var_escaped
->id
== escaped_id
);
6233 var_escaped
->is_artificial_var
= 1;
6234 var_escaped
->offset
= 0;
6235 var_escaped
->size
= ~0;
6236 var_escaped
->fullsize
= ~0;
6237 var_escaped
->is_special_var
= 0;
6239 /* Create the NONLOCAL variable, used to represent the set of nonlocal
6241 var_nonlocal
= new_var_info (NULL_TREE
, "NONLOCAL");
6242 gcc_assert (var_nonlocal
->id
== nonlocal_id
);
6243 var_nonlocal
->is_artificial_var
= 1;
6244 var_nonlocal
->offset
= 0;
6245 var_nonlocal
->size
= ~0;
6246 var_nonlocal
->fullsize
= ~0;
6247 var_nonlocal
->is_special_var
= 1;
6249 /* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
6251 lhs
.var
= escaped_id
;
6254 rhs
.var
= escaped_id
;
6256 process_constraint (new_constraint (lhs
, rhs
));
6258 /* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
6259 whole variable escapes. */
6261 lhs
.var
= escaped_id
;
6264 rhs
.var
= escaped_id
;
6265 rhs
.offset
= UNKNOWN_OFFSET
;
6266 process_constraint (new_constraint (lhs
, rhs
));
6268 /* *ESCAPED = NONLOCAL. This is true because we have to assume
6269 everything pointed to by escaped points to what global memory can
6272 lhs
.var
= escaped_id
;
6275 rhs
.var
= nonlocal_id
;
6277 process_constraint (new_constraint (lhs
, rhs
));
6279 /* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
6280 global memory may point to global memory and escaped memory. */
6282 lhs
.var
= nonlocal_id
;
6284 rhs
.type
= ADDRESSOF
;
6285 rhs
.var
= nonlocal_id
;
6287 process_constraint (new_constraint (lhs
, rhs
));
6288 rhs
.type
= ADDRESSOF
;
6289 rhs
.var
= escaped_id
;
6291 process_constraint (new_constraint (lhs
, rhs
));
6293 /* Create the STOREDANYTHING variable, used to represent the set of
6294 variables stored to *ANYTHING. */
6295 var_storedanything
= new_var_info (NULL_TREE
, "STOREDANYTHING");
6296 gcc_assert (var_storedanything
->id
== storedanything_id
);
6297 var_storedanything
->is_artificial_var
= 1;
6298 var_storedanything
->offset
= 0;
6299 var_storedanything
->size
= ~0;
6300 var_storedanything
->fullsize
= ~0;
6301 var_storedanything
->is_special_var
= 0;
6303 /* Create the INTEGER variable, used to represent that a variable points
6304 to what an INTEGER "points to". */
6305 var_integer
= new_var_info (NULL_TREE
, "INTEGER");
6306 gcc_assert (var_integer
->id
== integer_id
);
6307 var_integer
->is_artificial_var
= 1;
6308 var_integer
->size
= ~0;
6309 var_integer
->fullsize
= ~0;
6310 var_integer
->offset
= 0;
6311 var_integer
->next
= NULL
;
6312 var_integer
->is_special_var
= 1;
6314 /* INTEGER = ANYTHING, because we don't know where a dereference of
6315 a random integer will point to. */
6317 lhs
.var
= integer_id
;
6319 rhs
.type
= ADDRESSOF
;
6320 rhs
.var
= anything_id
;
6322 process_constraint (new_constraint (lhs
, rhs
));
6325 /* Initialize things necessary to perform PTA */
6328 init_alias_vars (void)
6330 use_field_sensitive
= (MAX_FIELDS_FOR_FIELD_SENSITIVE
> 1);
6332 bitmap_obstack_initialize (&pta_obstack
);
6333 bitmap_obstack_initialize (&oldpta_obstack
);
6334 bitmap_obstack_initialize (&predbitmap_obstack
);
6336 constraint_pool
= create_alloc_pool ("Constraint pool",
6337 sizeof (struct constraint
), 30);
6338 variable_info_pool
= create_alloc_pool ("Variable info pool",
6339 sizeof (struct variable_info
), 30);
6340 constraints
= VEC_alloc (constraint_t
, heap
, 8);
6341 varmap
= VEC_alloc (varinfo_t
, heap
, 8);
6342 vi_for_tree
= pointer_map_create ();
6343 call_stmt_vars
= pointer_map_create ();
6345 memset (&stats
, 0, sizeof (stats
));
6346 shared_bitmap_table
= htab_create (511, shared_bitmap_hash
,
6347 shared_bitmap_eq
, free
);
6351 /* Remove the REF and ADDRESS edges from GRAPH, as well as all the
6352 predecessor edges. */
6355 remove_preds_and_fake_succs (constraint_graph_t graph
)
6359 /* Clear the implicit ref and address nodes from the successor
6361 for (i
= 0; i
< FIRST_REF_NODE
; i
++)
6363 if (graph
->succs
[i
])
6364 bitmap_clear_range (graph
->succs
[i
], FIRST_REF_NODE
,
6365 FIRST_REF_NODE
* 2);
6368 /* Free the successor list for the non-ref nodes. */
6369 for (i
= FIRST_REF_NODE
; i
< graph
->size
; i
++)
6371 if (graph
->succs
[i
])
6372 BITMAP_FREE (graph
->succs
[i
]);
6375 /* Now reallocate the size of the successor list as, and blow away
6376 the predecessor bitmaps. */
6377 graph
->size
= VEC_length (varinfo_t
, varmap
);
6378 graph
->succs
= XRESIZEVEC (bitmap
, graph
->succs
, graph
->size
);
6380 free (graph
->implicit_preds
);
6381 graph
->implicit_preds
= NULL
;
6382 free (graph
->preds
);
6383 graph
->preds
= NULL
;
6384 bitmap_obstack_release (&predbitmap_obstack
);
6387 /* Initialize the heapvar for statement mapping. */
6390 init_alias_heapvars (void)
6392 if (!heapvar_for_stmt
)
6393 heapvar_for_stmt
= htab_create_ggc (11, tree_map_hash
, heapvar_map_eq
,
6397 /* Delete the heapvar for statement mapping. */
6400 delete_alias_heapvars (void)
6402 if (heapvar_for_stmt
)
6403 htab_delete (heapvar_for_stmt
);
6404 heapvar_for_stmt
= NULL
;
6407 /* Solve the constraint set. */
6410 solve_constraints (void)
6412 struct scc_info
*si
;
6416 "\nCollapsing static cycles and doing variable "
6419 init_graph (VEC_length (varinfo_t
, varmap
) * 2);
6422 fprintf (dump_file
, "Building predecessor graph\n");
6423 build_pred_graph ();
6426 fprintf (dump_file
, "Detecting pointer and location "
6428 si
= perform_var_substitution (graph
);
6431 fprintf (dump_file
, "Rewriting constraints and unifying "
6433 rewrite_constraints (graph
, si
);
6435 build_succ_graph ();
6436 free_var_substitution_info (si
);
6438 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
6439 dump_constraint_graph (dump_file
);
6441 move_complex_constraints (graph
);
6444 fprintf (dump_file
, "Uniting pointer but not location equivalent "
6446 unite_pointer_equivalences (graph
);
6449 fprintf (dump_file
, "Finding indirect cycles\n");
6450 find_indirect_cycles (graph
);
6452 /* Implicit nodes and predecessors are no longer necessary at this
6454 remove_preds_and_fake_succs (graph
);
6457 fprintf (dump_file
, "Solving graph\n");
6459 solve_graph (graph
);
6462 dump_sa_points_to_info (dump_file
);
6465 /* Create points-to sets for the current function. See the comments
6466 at the start of the file for an algorithmic overview. */
6469 compute_points_to_sets (void)
6475 timevar_push (TV_TREE_PTA
);
6478 init_alias_heapvars ();
6480 intra_create_variable_infos ();
6482 /* Now walk all statements and build the constraint set. */
6485 gimple_stmt_iterator gsi
;
6487 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6489 gimple phi
= gsi_stmt (gsi
);
6491 if (is_gimple_reg (gimple_phi_result (phi
)))
6492 find_func_aliases (phi
);
6495 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6497 gimple stmt
= gsi_stmt (gsi
);
6499 find_func_aliases (stmt
);
6505 fprintf (dump_file
, "Points-to analysis\n\nConstraints:\n\n");
6506 dump_constraints (dump_file
, 0);
6509 /* From the constraints compute the points-to sets. */
6510 solve_constraints ();
6512 /* Compute the points-to set for ESCAPED used for call-clobber analysis. */
6513 find_what_var_points_to (get_varinfo (escaped_id
),
6514 &cfun
->gimple_df
->escaped
);
6516 /* Make sure the ESCAPED solution (which is used as placeholder in
6517 other solutions) does not reference itself. This simplifies
6518 points-to solution queries. */
6519 cfun
->gimple_df
->escaped
.escaped
= 0;
6521 /* Mark escaped HEAP variables as global. */
6522 FOR_EACH_VEC_ELT (varinfo_t
, varmap
, i
, vi
)
6524 && !vi
->is_restrict_var
6525 && !vi
->is_global_var
)
6526 DECL_EXTERNAL (vi
->decl
) = vi
->is_global_var
6527 = pt_solution_includes (&cfun
->gimple_df
->escaped
, vi
->decl
);
6529 /* Compute the points-to sets for pointer SSA_NAMEs. */
6530 for (i
= 0; i
< num_ssa_names
; ++i
)
6532 tree ptr
= ssa_name (i
);
6534 && POINTER_TYPE_P (TREE_TYPE (ptr
)))
6535 find_what_p_points_to (ptr
);
6538 /* Compute the call-used/clobbered sets. */
6541 gimple_stmt_iterator gsi
;
6543 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6545 gimple stmt
= gsi_stmt (gsi
);
6546 struct pt_solution
*pt
;
6547 if (!is_gimple_call (stmt
))
6550 pt
= gimple_call_use_set (stmt
);
6551 if (gimple_call_flags (stmt
) & ECF_CONST
)
6552 memset (pt
, 0, sizeof (struct pt_solution
));
6553 else if ((vi
= lookup_call_use_vi (stmt
)) != NULL
)
6555 find_what_var_points_to (vi
, pt
);
6556 /* Escaped (and thus nonlocal) variables are always
6557 implicitly used by calls. */
6558 /* ??? ESCAPED can be empty even though NONLOCAL
6565 /* If there is nothing special about this call then
6566 we have made everything that is used also escape. */
6567 *pt
= cfun
->gimple_df
->escaped
;
6571 pt
= gimple_call_clobber_set (stmt
);
6572 if (gimple_call_flags (stmt
) & (ECF_CONST
|ECF_PURE
|ECF_NOVOPS
))
6573 memset (pt
, 0, sizeof (struct pt_solution
));
6574 else if ((vi
= lookup_call_clobber_vi (stmt
)) != NULL
)
6576 find_what_var_points_to (vi
, pt
);
6577 /* Escaped (and thus nonlocal) variables are always
6578 implicitly clobbered by calls. */
6579 /* ??? ESCAPED can be empty even though NONLOCAL
6586 /* If there is nothing special about this call then
6587 we have made everything that is used also escape. */
6588 *pt
= cfun
->gimple_df
->escaped
;
6594 timevar_pop (TV_TREE_PTA
);
6598 /* Delete created points-to sets. */
6601 delete_points_to_sets (void)
6605 htab_delete (shared_bitmap_table
);
6606 if (dump_file
&& (dump_flags
& TDF_STATS
))
6607 fprintf (dump_file
, "Points to sets created:%d\n",
6608 stats
.points_to_sets_created
);
6610 pointer_map_destroy (vi_for_tree
);
6611 pointer_map_destroy (call_stmt_vars
);
6612 bitmap_obstack_release (&pta_obstack
);
6613 VEC_free (constraint_t
, heap
, constraints
);
6615 for (i
= 0; i
< graph
->size
; i
++)
6616 VEC_free (constraint_t
, heap
, graph
->complex[i
]);
6617 free (graph
->complex);
6620 free (graph
->succs
);
6622 free (graph
->pe_rep
);
6623 free (graph
->indirect_cycles
);
6626 VEC_free (varinfo_t
, heap
, varmap
);
6627 free_alloc_pool (variable_info_pool
);
6628 free_alloc_pool (constraint_pool
);
6632 /* Compute points-to information for every SSA_NAME pointer in the
6633 current function and compute the transitive closure of escaped
6634 variables to re-initialize the call-clobber states of local variables. */
6637 compute_may_aliases (void)
6639 if (cfun
->gimple_df
->ipa_pta
)
6643 fprintf (dump_file
, "\nNot re-computing points-to information "
6644 "because IPA points-to information is available.\n\n");
6646 /* But still dump what we have remaining it. */
6647 dump_alias_info (dump_file
);
6649 if (dump_flags
& TDF_DETAILS
)
6650 dump_referenced_vars (dump_file
);
6656 /* For each pointer P_i, determine the sets of variables that P_i may
6657 point-to. Compute the reachability set of escaped and call-used
6659 compute_points_to_sets ();
6661 /* Debugging dumps. */
6664 dump_alias_info (dump_file
);
6666 if (dump_flags
& TDF_DETAILS
)
6667 dump_referenced_vars (dump_file
);
6670 /* Deallocate memory used by aliasing data structures and the internal
6671 points-to solution. */
6672 delete_points_to_sets ();
6674 gcc_assert (!need_ssa_update_p (cfun
));
6680 gate_tree_pta (void)
6682 return flag_tree_pta
;
6685 /* A dummy pass to cause points-to information to be computed via
6686 TODO_rebuild_alias. */
6688 struct gimple_opt_pass pass_build_alias
=
6693 gate_tree_pta
, /* gate */
6697 0, /* static_pass_number */
6698 TV_NONE
, /* tv_id */
6699 PROP_cfg
| PROP_ssa
, /* properties_required */
6700 0, /* properties_provided */
6701 0, /* properties_destroyed */
6702 0, /* todo_flags_start */
6703 TODO_rebuild_alias
| TODO_dump_func
/* todo_flags_finish */
6707 /* A dummy pass to cause points-to information to be computed via
6708 TODO_rebuild_alias. */
6710 struct gimple_opt_pass pass_build_ealias
=
6714 "ealias", /* name */
6715 gate_tree_pta
, /* gate */
6719 0, /* static_pass_number */
6720 TV_NONE
, /* tv_id */
6721 PROP_cfg
| PROP_ssa
, /* properties_required */
6722 0, /* properties_provided */
6723 0, /* properties_destroyed */
6724 0, /* todo_flags_start */
6725 TODO_rebuild_alias
| TODO_dump_func
/* todo_flags_finish */
6730 /* Return true if we should execute IPA PTA. */
6736 /* Don't bother doing anything if the program has errors. */
6740 /* IPA PTA solutions for ESCAPED. */
6741 struct pt_solution ipa_escaped_pt
6742 = { true, false, false, false, false, false, false, NULL
};
6744 /* Execute the driver for IPA PTA. */
6746 ipa_pta_execute (void)
6748 struct cgraph_node
*node
;
6749 struct varpool_node
*var
;
6754 init_alias_heapvars ();
6757 /* Build the constraints. */
6758 for (node
= cgraph_nodes
; node
; node
= node
->next
)
6760 struct cgraph_node
*alias
;
6763 /* Nodes without a body are not interesting. Especially do not
6764 visit clones at this point for now - we get duplicate decls
6765 there for inline clones at least. */
6766 if (!gimple_has_body_p (node
->decl
)
6770 vi
= create_function_info_for (node
->decl
,
6771 alias_get_name (node
->decl
));
6773 /* Associate the varinfo node with all aliases. */
6774 for (alias
= node
->same_body
; alias
; alias
= alias
->next
)
6775 insert_vi_for_tree (alias
->decl
, vi
);
6778 /* Create constraints for global variables and their initializers. */
6779 for (var
= varpool_nodes
; var
; var
= var
->next
)
6781 struct varpool_node
*alias
;
6784 vi
= get_vi_for_tree (var
->decl
);
6786 /* Associate the varinfo node with all aliases. */
6787 for (alias
= var
->extra_name
; alias
; alias
= alias
->next
)
6788 insert_vi_for_tree (alias
->decl
, vi
);
6794 "Generating constraints for global initializers\n\n");
6795 dump_constraints (dump_file
, 0);
6796 fprintf (dump_file
, "\n");
6798 from
= VEC_length (constraint_t
, constraints
);
6800 for (node
= cgraph_nodes
; node
; node
= node
->next
)
6802 struct function
*func
;
6806 /* Nodes without a body are not interesting. */
6807 if (!gimple_has_body_p (node
->decl
)
6814 "Generating constraints for %s", cgraph_node_name (node
));
6815 if (DECL_ASSEMBLER_NAME_SET_P (node
->decl
))
6816 fprintf (dump_file
, " (%s)",
6817 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node
->decl
)));
6818 fprintf (dump_file
, "\n");
6821 func
= DECL_STRUCT_FUNCTION (node
->decl
);
6822 old_func_decl
= current_function_decl
;
6824 current_function_decl
= node
->decl
;
6826 /* For externally visible functions use local constraints for
6827 their arguments. For local functions we see all callers
6828 and thus do not need initial constraints for parameters. */
6829 if (node
->local
.externally_visible
)
6830 intra_create_variable_infos ();
6832 /* Build constriants for the function body. */
6833 FOR_EACH_BB_FN (bb
, func
)
6835 gimple_stmt_iterator gsi
;
6837 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
6840 gimple phi
= gsi_stmt (gsi
);
6842 if (is_gimple_reg (gimple_phi_result (phi
)))
6843 find_func_aliases (phi
);
6846 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6848 gimple stmt
= gsi_stmt (gsi
);
6850 find_func_aliases (stmt
);
6851 find_func_clobbers (stmt
);
6855 current_function_decl
= old_func_decl
;
6860 fprintf (dump_file
, "\n");
6861 dump_constraints (dump_file
, from
);
6862 fprintf (dump_file
, "\n");
6864 from
= VEC_length (constraint_t
, constraints
);
6867 /* From the constraints compute the points-to sets. */
6868 solve_constraints ();
6870 /* Compute the global points-to sets for ESCAPED.
6871 ??? Note that the computed escape set is not correct
6872 for the whole unit as we fail to consider graph edges to
6873 externally visible functions. */
6874 find_what_var_points_to (get_varinfo (escaped_id
), &ipa_escaped_pt
);
6876 /* Make sure the ESCAPED solution (which is used as placeholder in
6877 other solutions) does not reference itself. This simplifies
6878 points-to solution queries. */
6879 ipa_escaped_pt
.ipa_escaped
= 0;
6881 /* Assign the points-to sets to the SSA names in the unit. */
6882 for (node
= cgraph_nodes
; node
; node
= node
->next
)
6885 struct function
*fn
;
6889 struct pt_solution uses
, clobbers
;
6890 struct cgraph_edge
*e
;
6892 /* Nodes without a body are not interesting. */
6893 if (!gimple_has_body_p (node
->decl
)
6897 fn
= DECL_STRUCT_FUNCTION (node
->decl
);
6899 /* Compute the points-to sets for pointer SSA_NAMEs. */
6900 FOR_EACH_VEC_ELT (tree
, fn
->gimple_df
->ssa_names
, i
, ptr
)
6903 && POINTER_TYPE_P (TREE_TYPE (ptr
)))
6904 find_what_p_points_to (ptr
);
6907 /* Compute the call-use and call-clobber sets for all direct calls. */
6908 fi
= lookup_vi_for_tree (node
->decl
);
6909 gcc_assert (fi
->is_fn_info
);
6910 find_what_var_points_to (first_vi_for_offset (fi
, fi_clobbers
),
6912 find_what_var_points_to (first_vi_for_offset (fi
, fi_uses
), &uses
);
6913 for (e
= node
->callers
; e
; e
= e
->next_caller
)
6918 *gimple_call_clobber_set (e
->call_stmt
) = clobbers
;
6919 *gimple_call_use_set (e
->call_stmt
) = uses
;
6922 /* Compute the call-use and call-clobber sets for indirect calls
6923 and calls to external functions. */
6924 FOR_EACH_BB_FN (bb
, fn
)
6926 gimple_stmt_iterator gsi
;
6928 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6930 gimple stmt
= gsi_stmt (gsi
);
6931 struct pt_solution
*pt
;
6935 if (!is_gimple_call (stmt
))
6938 /* Handle direct calls to external functions. */
6939 decl
= gimple_call_fndecl (stmt
);
6941 && (!(fi
= lookup_vi_for_tree (decl
))
6942 || !fi
->is_fn_info
))
6944 pt
= gimple_call_use_set (stmt
);
6945 if (gimple_call_flags (stmt
) & ECF_CONST
)
6946 memset (pt
, 0, sizeof (struct pt_solution
));
6947 else if ((vi
= lookup_call_use_vi (stmt
)) != NULL
)
6949 find_what_var_points_to (vi
, pt
);
6950 /* Escaped (and thus nonlocal) variables are always
6951 implicitly used by calls. */
6952 /* ??? ESCAPED can be empty even though NONLOCAL
6955 pt
->ipa_escaped
= 1;
6959 /* If there is nothing special about this call then
6960 we have made everything that is used also escape. */
6961 *pt
= ipa_escaped_pt
;
6965 pt
= gimple_call_clobber_set (stmt
);
6966 if (gimple_call_flags (stmt
) & (ECF_CONST
|ECF_PURE
|ECF_NOVOPS
))
6967 memset (pt
, 0, sizeof (struct pt_solution
));
6968 else if ((vi
= lookup_call_clobber_vi (stmt
)) != NULL
)
6970 find_what_var_points_to (vi
, pt
);
6971 /* Escaped (and thus nonlocal) variables are always
6972 implicitly clobbered by calls. */
6973 /* ??? ESCAPED can be empty even though NONLOCAL
6976 pt
->ipa_escaped
= 1;
6980 /* If there is nothing special about this call then
6981 we have made everything that is used also escape. */
6982 *pt
= ipa_escaped_pt
;
6987 /* Handle indirect calls. */
6989 && (fi
= get_fi_for_callee (stmt
)))
6991 /* We need to accumulate all clobbers/uses of all possible
6993 fi
= get_varinfo (find (fi
->id
));
6994 /* If we cannot constrain the set of functions we'll end up
6995 calling we end up using/clobbering everything. */
6996 if (bitmap_bit_p (fi
->solution
, anything_id
)
6997 || bitmap_bit_p (fi
->solution
, nonlocal_id
)
6998 || bitmap_bit_p (fi
->solution
, escaped_id
))
7000 pt_solution_reset (gimple_call_clobber_set (stmt
));
7001 pt_solution_reset (gimple_call_use_set (stmt
));
7007 struct pt_solution
*uses
, *clobbers
;
7009 uses
= gimple_call_use_set (stmt
);
7010 clobbers
= gimple_call_clobber_set (stmt
);
7011 memset (uses
, 0, sizeof (struct pt_solution
));
7012 memset (clobbers
, 0, sizeof (struct pt_solution
));
7013 EXECUTE_IF_SET_IN_BITMAP (fi
->solution
, 0, i
, bi
)
7015 struct pt_solution sol
;
7017 vi
= get_varinfo (i
);
7018 if (!vi
->is_fn_info
)
7020 /* ??? We could be more precise here? */
7022 uses
->ipa_escaped
= 1;
7023 clobbers
->nonlocal
= 1;
7024 clobbers
->ipa_escaped
= 1;
7028 if (!uses
->anything
)
7030 find_what_var_points_to
7031 (first_vi_for_offset (vi
, fi_uses
), &sol
);
7032 pt_solution_ior_into (uses
, &sol
);
7034 if (!clobbers
->anything
)
7036 find_what_var_points_to
7037 (first_vi_for_offset (vi
, fi_clobbers
), &sol
);
7038 pt_solution_ior_into (clobbers
, &sol
);
7046 fn
->gimple_df
->ipa_pta
= true;
7049 delete_points_to_sets ();
7056 struct simple_ipa_opt_pass pass_ipa_pta
=
7061 gate_ipa_pta
, /* gate */
7062 ipa_pta_execute
, /* execute */
7065 0, /* static_pass_number */
7066 TV_IPA_PTA
, /* tv_id */
7067 0, /* properties_required */
7068 0, /* properties_provided */
7069 0, /* properties_destroyed */
7070 0, /* todo_flags_start */
7071 TODO_update_ssa
/* todo_flags_finish */
7076 #include "gt-tree-ssa-structalias.h"