1 /* Tree based points-to analysis
2 Copyright (C) 2005-2015 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dberlin@dberlin.org>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
28 #include "alloc-pool.h"
29 #include "tree-pass.h"
32 #include "tree-pretty-print.h"
33 #include "diagnostic-core.h"
34 #include "fold-const.h"
35 #include "stor-layout.h"
37 #include "gimple-iterator.h"
38 #include "tree-into-ssa.h"
41 #include "gimple-walk.h"
43 /* The idea behind this analyzer is to generate set constraints from the
44 program, then solve the resulting constraints in order to generate the
47 Set constraints are a way of modeling program analysis problems that
48 involve sets. They consist of an inclusion constraint language,
49 describing the variables (each variable is a set) and operations that
50 are involved on the variables, and a set of rules that derive facts
51 from these operations. To solve a system of set constraints, you derive
52 all possible facts under the rules, which gives you the correct sets
55 See "Efficient Field-sensitive pointer analysis for C" by "David
56 J. Pearce and Paul H. J. Kelly and Chris Hankin, at
57 http://citeseer.ist.psu.edu/pearce04efficient.html
59 Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
60 of C Code in a Second" by ""Nevin Heintze and Olivier Tardieu" at
61 http://citeseer.ist.psu.edu/heintze01ultrafast.html
63 There are three types of real constraint expressions, DEREF,
64 ADDRESSOF, and SCALAR. Each constraint expression consists
65 of a constraint type, a variable, and an offset.
67 SCALAR is a constraint expression type used to represent x, whether
68 it appears on the LHS or the RHS of a statement.
69 DEREF is a constraint expression type used to represent *x, whether
70 it appears on the LHS or the RHS of a statement.
71 ADDRESSOF is a constraint expression used to represent &x, whether
72 it appears on the LHS or the RHS of a statement.
74 Each pointer variable in the program is assigned an integer id, and
75 each field of a structure variable is assigned an integer id as well.
77 Structure variables are linked to their list of fields through a "next
78 field" in each variable that points to the next field in offset
80 Each variable for a structure field has
82 1. "size", that tells the size in bits of that field.
83 2. "fullsize, that tells the size in bits of the entire structure.
84 3. "offset", that tells the offset in bits from the beginning of the
85 structure to this field.
97 foo.a -> id 1, size 32, offset 0, fullsize 64, next foo.b
98 foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
99 bar -> id 3, size 32, offset 0, fullsize 32, next NULL
102 In order to solve the system of set constraints, the following is
105 1. Each constraint variable x has a solution set associated with it,
108 2. Constraints are separated into direct, copy, and complex.
109 Direct constraints are ADDRESSOF constraints that require no extra
110 processing, such as P = &Q
111 Copy constraints are those of the form P = Q.
112 Complex constraints are all the constraints involving dereferences
113 and offsets (including offsetted copies).
115 3. All direct constraints of the form P = &Q are processed, such
116 that Q is added to Sol(P)
118 4. All complex constraints for a given constraint variable are stored in a
119 linked list attached to that variable's node.
121 5. A directed graph is built out of the copy constraints. Each
122 constraint variable is a node in the graph, and an edge from
123 Q to P is added for each copy constraint of the form P = Q
125 6. The graph is then walked, and solution sets are
126 propagated along the copy edges, such that an edge from Q to P
127 causes Sol(P) <- Sol(P) union Sol(Q).
129 7. As we visit each node, all complex constraints associated with
130 that node are processed by adding appropriate copy edges to the graph, or the
131 appropriate variables to the solution set.
133 8. The process of walking the graph is iterated until no solution
136 Prior to walking the graph in steps 6 and 7, We perform static
137 cycle elimination on the constraint graph, as well
138 as off-line variable substitution.
140 TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
141 on and turned into anything), but isn't. You can just see what offset
142 inside the pointed-to struct it's going to access.
144 TODO: Constant bounded arrays can be handled as if they were structs of the
145 same number of elements.
147 TODO: Modeling heap and incoming pointers becomes much better if we
148 add fields to them as we discover them, which we could do.
150 TODO: We could handle unions, but to be honest, it's probably not
151 worth the pain or slowdown. */
153 /* IPA-PTA optimizations possible.
155 When the indirect function called is ANYTHING we can add disambiguation
156 based on the function signatures (or simply the parameter count which
157 is the varinfo size). We also do not need to consider functions that
158 do not have their address taken.
160 The is_global_var bit which marks escape points is overly conservative
161 in IPA mode. Split it to is_escape_point and is_global_var - only
162 externally visible globals are escape points in IPA mode. This is
163 also needed to fix the pt_solution_includes_global predicate
164 (and thus ptr_deref_may_alias_global_p).
166 The way we introduce DECL_PT_UID to avoid fixing up all points-to
167 sets in the translation unit when we copy a DECL during inlining
168 pessimizes precision. The advantage is that the DECL_PT_UID keeps
169 compile-time and memory usage overhead low - the points-to sets
170 do not grow or get unshared as they would during a fixup phase.
171 An alternative solution is to delay IPA PTA until after all
172 inlining transformations have been applied.
174 The way we propagate clobber/use information isn't optimized.
175 It should use a new complex constraint that properly filters
176 out local variables of the callee (though that would make
177 the sets invalid after inlining). OTOH we might as well
178 admit defeat to WHOPR and simply do all the clobber/use analysis
179 and propagation after PTA finished but before we threw away
180 points-to information for memory variables. WHOPR and PTA
181 do not play along well anyway - the whole constraint solving
182 would need to be done in WPA phase and it will be very interesting
183 to apply the results to local SSA names during LTRANS phase.
185 We probably should compute a per-function unit-ESCAPE solution
186 propagating it simply like the clobber / uses solutions. The
187 solution can go alongside the non-IPA espaced solution and be
188 used to query which vars escape the unit through a function.
190 We never put function decls in points-to sets so we do not
191 keep the set of called functions for indirect calls.
193 And probably more. */
195 static bool use_field_sensitive
= true;
196 static int in_ipa_mode
= 0;
198 /* Used for predecessor bitmaps. */
199 static bitmap_obstack predbitmap_obstack
;
201 /* Used for points-to sets. */
202 static bitmap_obstack pta_obstack
;
204 /* Used for oldsolution members of variables. */
205 static bitmap_obstack oldpta_obstack
;
207 /* Used for per-solver-iteration bitmaps. */
208 static bitmap_obstack iteration_obstack
;
210 static unsigned int create_variable_info_for (tree
, const char *, bool);
211 typedef struct constraint_graph
*constraint_graph_t
;
212 static void unify_nodes (constraint_graph_t
, unsigned int, unsigned int, bool);
215 typedef struct constraint
*constraint_t
;
218 #define EXECUTE_IF_IN_NONNULL_BITMAP(a, b, c, d) \
220 EXECUTE_IF_SET_IN_BITMAP (a, b, c, d)
222 static struct constraint_stats
224 unsigned int total_vars
;
225 unsigned int nonpointer_vars
;
226 unsigned int unified_vars_static
;
227 unsigned int unified_vars_dynamic
;
228 unsigned int iterations
;
229 unsigned int num_edges
;
230 unsigned int num_implicit_edges
;
231 unsigned int points_to_sets_created
;
236 /* ID of this variable */
239 /* True if this is a variable created by the constraint analysis, such as
240 heap variables and constraints we had to break up. */
241 unsigned int is_artificial_var
: 1;
243 /* True if this is a special variable whose solution set should not be
245 unsigned int is_special_var
: 1;
247 /* True for variables whose size is not known or variable. */
248 unsigned int is_unknown_size_var
: 1;
250 /* True for (sub-)fields that represent a whole variable. */
251 unsigned int is_full_var
: 1;
253 /* True if this is a heap variable. */
254 unsigned int is_heap_var
: 1;
256 /* True if this field may contain pointers. */
257 unsigned int may_have_pointers
: 1;
259 /* True if this field has only restrict qualified pointers. */
260 unsigned int only_restrict_pointers
: 1;
262 /* True if this represents a heap var created for a restrict qualified
264 unsigned int is_restrict_var
: 1;
266 /* True if this represents a global variable. */
267 unsigned int is_global_var
: 1;
269 /* True if this represents a IPA function info. */
270 unsigned int is_fn_info
: 1;
272 /* ??? Store somewhere better. */
275 /* The ID of the variable for the next field in this structure
276 or zero for the last field in this structure. */
279 /* The ID of the variable for the first field in this structure. */
282 /* Offset of this variable, in bits, from the base variable */
283 unsigned HOST_WIDE_INT offset
;
285 /* Size of the variable, in bits. */
286 unsigned HOST_WIDE_INT size
;
288 /* Full size of the base variable, in bits. */
289 unsigned HOST_WIDE_INT fullsize
;
291 /* Name of this variable */
294 /* Tree that this variable is associated with. */
297 /* Points-to set for this variable. */
300 /* Old points-to set for this variable. */
303 typedef struct variable_info
*varinfo_t
;
305 static varinfo_t
first_vi_for_offset (varinfo_t
, unsigned HOST_WIDE_INT
);
306 static varinfo_t
first_or_preceding_vi_for_offset (varinfo_t
,
307 unsigned HOST_WIDE_INT
);
308 static varinfo_t
lookup_vi_for_tree (tree
);
309 static inline bool type_can_have_subvars (const_tree
);
310 static void make_param_constraints (varinfo_t
);
312 /* Pool of variable info structures. */
313 static object_allocator
<variable_info
> variable_info_pool
314 ("Variable info pool");
316 /* Map varinfo to final pt_solution. */
317 static hash_map
<varinfo_t
, pt_solution
*> *final_solutions
;
318 struct obstack final_solutions_obstack
;
320 /* Table of variable info structures for constraint variables.
321 Indexed directly by variable info id. */
322 static vec
<varinfo_t
> varmap
;
324 /* Return the varmap element N */
326 static inline varinfo_t
327 get_varinfo (unsigned int n
)
332 /* Return the next variable in the list of sub-variables of VI
333 or NULL if VI is the last sub-variable. */
335 static inline varinfo_t
336 vi_next (varinfo_t vi
)
338 return get_varinfo (vi
->next
);
341 /* Static IDs for the special variables. Variable ID zero is unused
342 and used as terminator for the sub-variable chain. */
343 enum { nothing_id
= 1, anything_id
= 2, string_id
= 3,
344 escaped_id
= 4, nonlocal_id
= 5,
345 storedanything_id
= 6, integer_id
= 7 };
347 /* Return a new variable info structure consisting for a variable
348 named NAME, and using constraint graph node NODE. Append it
349 to the vector of variable info structures. */
352 new_var_info (tree t
, const char *name
, bool add_id
)
354 unsigned index
= varmap
.length ();
355 varinfo_t ret
= variable_info_pool
.allocate ();
357 if (dump_file
&& add_id
)
359 char *tempname
= xasprintf ("%s(%d)", name
, index
);
360 name
= ggc_strdup (tempname
);
367 /* Vars without decl are artificial and do not have sub-variables. */
368 ret
->is_artificial_var
= (t
== NULL_TREE
);
369 ret
->is_special_var
= false;
370 ret
->is_unknown_size_var
= false;
371 ret
->is_full_var
= (t
== NULL_TREE
);
372 ret
->is_heap_var
= false;
373 ret
->may_have_pointers
= true;
374 ret
->only_restrict_pointers
= false;
375 ret
->is_restrict_var
= false;
377 ret
->is_global_var
= (t
== NULL_TREE
);
378 ret
->is_fn_info
= false;
380 ret
->is_global_var
= (is_global_var (t
)
381 /* We have to treat even local register variables
383 || (TREE_CODE (t
) == VAR_DECL
384 && DECL_HARD_REGISTER (t
)));
385 ret
->solution
= BITMAP_ALLOC (&pta_obstack
);
386 ret
->oldsolution
= NULL
;
392 varmap
.safe_push (ret
);
397 /* A map mapping call statements to per-stmt variables for uses
398 and clobbers specific to the call. */
399 static hash_map
<gimple
*, varinfo_t
> *call_stmt_vars
;
401 /* Lookup or create the variable for the call statement CALL. */
404 get_call_vi (gcall
*call
)
409 varinfo_t
*slot_p
= &call_stmt_vars
->get_or_insert (call
, &existed
);
413 vi
= new_var_info (NULL_TREE
, "CALLUSED", true);
417 vi
->is_full_var
= true;
419 vi2
= new_var_info (NULL_TREE
, "CALLCLOBBERED", true);
423 vi2
->is_full_var
= true;
431 /* Lookup the variable for the call statement CALL representing
432 the uses. Returns NULL if there is nothing special about this call. */
435 lookup_call_use_vi (gcall
*call
)
437 varinfo_t
*slot_p
= call_stmt_vars
->get (call
);
444 /* Lookup the variable for the call statement CALL representing
445 the clobbers. Returns NULL if there is nothing special about this call. */
448 lookup_call_clobber_vi (gcall
*call
)
450 varinfo_t uses
= lookup_call_use_vi (call
);
454 return vi_next (uses
);
457 /* Lookup or create the variable for the call statement CALL representing
461 get_call_use_vi (gcall
*call
)
463 return get_call_vi (call
);
466 /* Lookup or create the variable for the call statement CALL representing
469 static varinfo_t ATTRIBUTE_UNUSED
470 get_call_clobber_vi (gcall
*call
)
472 return vi_next (get_call_vi (call
));
476 enum constraint_expr_type
{SCALAR
, DEREF
, ADDRESSOF
};
478 /* An expression that appears in a constraint. */
480 struct constraint_expr
482 /* Constraint type. */
483 constraint_expr_type type
;
485 /* Variable we are referring to in the constraint. */
488 /* Offset, in bits, of this constraint from the beginning of
489 variables it ends up referring to.
491 IOW, in a deref constraint, we would deref, get the result set,
492 then add OFFSET to each member. */
493 HOST_WIDE_INT offset
;
496 /* Use 0x8000... as special unknown offset. */
497 #define UNKNOWN_OFFSET HOST_WIDE_INT_MIN
499 typedef struct constraint_expr ce_s
;
500 static void get_constraint_for_1 (tree
, vec
<ce_s
> *, bool, bool);
501 static void get_constraint_for (tree
, vec
<ce_s
> *);
502 static void get_constraint_for_rhs (tree
, vec
<ce_s
> *);
503 static void do_deref (vec
<ce_s
> *);
505 /* Our set constraints are made up of two constraint expressions, one
508 As described in the introduction, our set constraints each represent an
509 operation between set valued variables.
513 struct constraint_expr lhs
;
514 struct constraint_expr rhs
;
517 /* List of constraints that we use to build the constraint graph from. */
519 static vec
<constraint_t
> constraints
;
520 static object_allocator
<constraint
> constraint_pool ("Constraint pool");
522 /* The constraint graph is represented as an array of bitmaps
523 containing successor nodes. */
525 struct constraint_graph
527 /* Size of this graph, which may be different than the number of
528 nodes in the variable map. */
531 /* Explicit successors of each node. */
534 /* Implicit predecessors of each node (Used for variable
536 bitmap
*implicit_preds
;
538 /* Explicit predecessors of each node (Used for variable substitution). */
541 /* Indirect cycle representatives, or -1 if the node has no indirect
543 int *indirect_cycles
;
545 /* Representative node for a node. rep[a] == a unless the node has
549 /* Equivalence class representative for a label. This is used for
550 variable substitution. */
553 /* Pointer equivalence label for a node. All nodes with the same
554 pointer equivalence label can be unified together at some point
555 (either during constraint optimization or after the constraint
559 /* Pointer equivalence representative for a label. This is used to
560 handle nodes that are pointer equivalent but not location
561 equivalent. We can unite these once the addressof constraints
562 are transformed into initial points-to sets. */
565 /* Pointer equivalence label for each node, used during variable
567 unsigned int *pointer_label
;
569 /* Location equivalence label for each node, used during location
570 equivalence finding. */
571 unsigned int *loc_label
;
573 /* Pointed-by set for each node, used during location equivalence
574 finding. This is pointed-by rather than pointed-to, because it
575 is constructed using the predecessor graph. */
578 /* Points to sets for pointer equivalence. This is *not* the actual
579 points-to sets for nodes. */
582 /* Bitmap of nodes where the bit is set if the node is a direct
583 node. Used for variable substitution. */
584 sbitmap direct_nodes
;
586 /* Bitmap of nodes where the bit is set if the node is address
587 taken. Used for variable substitution. */
588 bitmap address_taken
;
590 /* Vector of complex constraints for each graph node. Complex
591 constraints are those involving dereferences or offsets that are
593 vec
<constraint_t
> *complex;
596 static constraint_graph_t graph
;
598 /* During variable substitution and the offline version of indirect
599 cycle finding, we create nodes to represent dereferences and
600 address taken constraints. These represent where these start and
602 #define FIRST_REF_NODE (varmap).length ()
603 #define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
605 /* Return the representative node for NODE, if NODE has been unioned
607 This function performs path compression along the way to finding
608 the representative. */
611 find (unsigned int node
)
613 gcc_checking_assert (node
< graph
->size
);
614 if (graph
->rep
[node
] != node
)
615 return graph
->rep
[node
] = find (graph
->rep
[node
]);
619 /* Union the TO and FROM nodes to the TO nodes.
620 Note that at some point in the future, we may want to do
621 union-by-rank, in which case we are going to have to return the
622 node we unified to. */
625 unite (unsigned int to
, unsigned int from
)
627 gcc_checking_assert (to
< graph
->size
&& from
< graph
->size
);
628 if (to
!= from
&& graph
->rep
[from
] != to
)
630 graph
->rep
[from
] = to
;
636 /* Create a new constraint consisting of LHS and RHS expressions. */
639 new_constraint (const struct constraint_expr lhs
,
640 const struct constraint_expr rhs
)
642 constraint_t ret
= constraint_pool
.allocate ();
648 /* Print out constraint C to FILE. */
651 dump_constraint (FILE *file
, constraint_t c
)
653 if (c
->lhs
.type
== ADDRESSOF
)
655 else if (c
->lhs
.type
== DEREF
)
657 fprintf (file
, "%s", get_varinfo (c
->lhs
.var
)->name
);
658 if (c
->lhs
.offset
== UNKNOWN_OFFSET
)
659 fprintf (file
, " + UNKNOWN");
660 else if (c
->lhs
.offset
!= 0)
661 fprintf (file
, " + " HOST_WIDE_INT_PRINT_DEC
, c
->lhs
.offset
);
662 fprintf (file
, " = ");
663 if (c
->rhs
.type
== ADDRESSOF
)
665 else if (c
->rhs
.type
== DEREF
)
667 fprintf (file
, "%s", get_varinfo (c
->rhs
.var
)->name
);
668 if (c
->rhs
.offset
== UNKNOWN_OFFSET
)
669 fprintf (file
, " + UNKNOWN");
670 else if (c
->rhs
.offset
!= 0)
671 fprintf (file
, " + " HOST_WIDE_INT_PRINT_DEC
, c
->rhs
.offset
);
675 void debug_constraint (constraint_t
);
676 void debug_constraints (void);
677 void debug_constraint_graph (void);
678 void debug_solution_for_var (unsigned int);
679 void debug_sa_points_to_info (void);
681 /* Print out constraint C to stderr. */
684 debug_constraint (constraint_t c
)
686 dump_constraint (stderr
, c
);
687 fprintf (stderr
, "\n");
690 /* Print out all constraints to FILE */
693 dump_constraints (FILE *file
, int from
)
697 for (i
= from
; constraints
.iterate (i
, &c
); i
++)
700 dump_constraint (file
, c
);
701 fprintf (file
, "\n");
705 /* Print out all constraints to stderr. */
708 debug_constraints (void)
710 dump_constraints (stderr
, 0);
713 /* Print the constraint graph in dot format. */
716 dump_constraint_graph (FILE *file
)
720 /* Only print the graph if it has already been initialized: */
724 /* Prints the header of the dot file: */
725 fprintf (file
, "strict digraph {\n");
726 fprintf (file
, " node [\n shape = box\n ]\n");
727 fprintf (file
, " edge [\n fontsize = \"12\"\n ]\n");
728 fprintf (file
, "\n // List of nodes and complex constraints in "
729 "the constraint graph:\n");
731 /* The next lines print the nodes in the graph together with the
732 complex constraints attached to them. */
733 for (i
= 1; i
< graph
->size
; i
++)
735 if (i
== FIRST_REF_NODE
)
739 if (i
< FIRST_REF_NODE
)
740 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
742 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
743 if (graph
->complex[i
].exists ())
747 fprintf (file
, " [label=\"\\N\\n");
748 for (j
= 0; graph
->complex[i
].iterate (j
, &c
); ++j
)
750 dump_constraint (file
, c
);
751 fprintf (file
, "\\l");
753 fprintf (file
, "\"]");
755 fprintf (file
, ";\n");
758 /* Go over the edges. */
759 fprintf (file
, "\n // Edges in the constraint graph:\n");
760 for (i
= 1; i
< graph
->size
; i
++)
766 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[i
], 0, j
, bi
)
768 unsigned to
= find (j
);
771 if (i
< FIRST_REF_NODE
)
772 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
774 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
775 fprintf (file
, " -> ");
776 if (to
< FIRST_REF_NODE
)
777 fprintf (file
, "\"%s\"", get_varinfo (to
)->name
);
779 fprintf (file
, "\"*%s\"", get_varinfo (to
- FIRST_REF_NODE
)->name
);
780 fprintf (file
, ";\n");
784 /* Prints the tail of the dot file. */
785 fprintf (file
, "}\n");
788 /* Print out the constraint graph to stderr. */
791 debug_constraint_graph (void)
793 dump_constraint_graph (stderr
);
798 The solver is a simple worklist solver, that works on the following
801 sbitmap changed_nodes = all zeroes;
803 For each node that is not already collapsed:
805 set bit in changed nodes
807 while (changed_count > 0)
809 compute topological ordering for constraint graph
811 find and collapse cycles in the constraint graph (updating
812 changed if necessary)
814 for each node (n) in the graph in topological order:
817 Process each complex constraint associated with the node,
818 updating changed if necessary.
820 For each outgoing edge from n, propagate the solution from n to
821 the destination of the edge, updating changed as necessary.
825 /* Return true if two constraint expressions A and B are equal. */
828 constraint_expr_equal (struct constraint_expr a
, struct constraint_expr b
)
830 return a
.type
== b
.type
&& a
.var
== b
.var
&& a
.offset
== b
.offset
;
833 /* Return true if constraint expression A is less than constraint expression
834 B. This is just arbitrary, but consistent, in order to give them an
838 constraint_expr_less (struct constraint_expr a
, struct constraint_expr b
)
840 if (a
.type
== b
.type
)
843 return a
.offset
< b
.offset
;
845 return a
.var
< b
.var
;
848 return a
.type
< b
.type
;
851 /* Return true if constraint A is less than constraint B. This is just
852 arbitrary, but consistent, in order to give them an ordering. */
855 constraint_less (const constraint_t
&a
, const constraint_t
&b
)
857 if (constraint_expr_less (a
->lhs
, b
->lhs
))
859 else if (constraint_expr_less (b
->lhs
, a
->lhs
))
862 return constraint_expr_less (a
->rhs
, b
->rhs
);
865 /* Return true if two constraints A and B are equal. */
868 constraint_equal (struct constraint a
, struct constraint b
)
870 return constraint_expr_equal (a
.lhs
, b
.lhs
)
871 && constraint_expr_equal (a
.rhs
, b
.rhs
);
875 /* Find a constraint LOOKFOR in the sorted constraint vector VEC */
878 constraint_vec_find (vec
<constraint_t
> vec
,
879 struct constraint lookfor
)
887 place
= vec
.lower_bound (&lookfor
, constraint_less
);
888 if (place
>= vec
.length ())
891 if (!constraint_equal (*found
, lookfor
))
896 /* Union two constraint vectors, TO and FROM. Put the result in TO.
897 Returns true of TO set is changed. */
900 constraint_set_union (vec
<constraint_t
> *to
,
901 vec
<constraint_t
> *from
)
905 bool any_change
= false;
907 FOR_EACH_VEC_ELT (*from
, i
, c
)
909 if (constraint_vec_find (*to
, *c
) == NULL
)
911 unsigned int place
= to
->lower_bound (c
, constraint_less
);
912 to
->safe_insert (place
, c
);
919 /* Expands the solution in SET to all sub-fields of variables included. */
922 solution_set_expand (bitmap set
, bitmap
*expanded
)
930 *expanded
= BITMAP_ALLOC (&iteration_obstack
);
932 /* In a first pass expand to the head of the variables we need to
933 add all sub-fields off. This avoids quadratic behavior. */
934 EXECUTE_IF_SET_IN_BITMAP (set
, 0, j
, bi
)
936 varinfo_t v
= get_varinfo (j
);
937 if (v
->is_artificial_var
940 bitmap_set_bit (*expanded
, v
->head
);
943 /* In the second pass now expand all head variables with subfields. */
944 EXECUTE_IF_SET_IN_BITMAP (*expanded
, 0, j
, bi
)
946 varinfo_t v
= get_varinfo (j
);
949 for (v
= vi_next (v
); v
!= NULL
; v
= vi_next (v
))
950 bitmap_set_bit (*expanded
, v
->id
);
953 /* And finally set the rest of the bits from SET. */
954 bitmap_ior_into (*expanded
, set
);
959 /* Union solution sets TO and DELTA, and add INC to each member of DELTA in the
963 set_union_with_increment (bitmap to
, bitmap delta
, HOST_WIDE_INT inc
,
964 bitmap
*expanded_delta
)
966 bool changed
= false;
970 /* If the solution of DELTA contains anything it is good enough to transfer
972 if (bitmap_bit_p (delta
, anything_id
))
973 return bitmap_set_bit (to
, anything_id
);
975 /* If the offset is unknown we have to expand the solution to
977 if (inc
== UNKNOWN_OFFSET
)
979 delta
= solution_set_expand (delta
, expanded_delta
);
980 changed
|= bitmap_ior_into (to
, delta
);
984 /* For non-zero offset union the offsetted solution into the destination. */
985 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, i
, bi
)
987 varinfo_t vi
= get_varinfo (i
);
989 /* If this is a variable with just one field just set its bit
991 if (vi
->is_artificial_var
992 || vi
->is_unknown_size_var
994 changed
|= bitmap_set_bit (to
, i
);
997 HOST_WIDE_INT fieldoffset
= vi
->offset
+ inc
;
998 unsigned HOST_WIDE_INT size
= vi
->size
;
1000 /* If the offset makes the pointer point to before the
1001 variable use offset zero for the field lookup. */
1002 if (fieldoffset
< 0)
1003 vi
= get_varinfo (vi
->head
);
1005 vi
= first_or_preceding_vi_for_offset (vi
, fieldoffset
);
1009 changed
|= bitmap_set_bit (to
, vi
->id
);
1014 /* We have to include all fields that overlap the current field
1018 while (vi
->offset
< fieldoffset
+ size
);
1025 /* Insert constraint C into the list of complex constraints for graph
1029 insert_into_complex (constraint_graph_t graph
,
1030 unsigned int var
, constraint_t c
)
1032 vec
<constraint_t
> complex = graph
->complex[var
];
1033 unsigned int place
= complex.lower_bound (c
, constraint_less
);
1035 /* Only insert constraints that do not already exist. */
1036 if (place
>= complex.length ()
1037 || !constraint_equal (*c
, *complex[place
]))
1038 graph
->complex[var
].safe_insert (place
, c
);
1042 /* Condense two variable nodes into a single variable node, by moving
1043 all associated info from FROM to TO. Returns true if TO node's
1044 constraint set changes after the merge. */
1047 merge_node_constraints (constraint_graph_t graph
, unsigned int to
,
1052 bool any_change
= false;
1054 gcc_checking_assert (find (from
) == to
);
1056 /* Move all complex constraints from src node into to node */
1057 FOR_EACH_VEC_ELT (graph
->complex[from
], i
, c
)
1059 /* In complex constraints for node FROM, we may have either
1060 a = *FROM, and *FROM = a, or an offseted constraint which are
1061 always added to the rhs node's constraints. */
1063 if (c
->rhs
.type
== DEREF
)
1065 else if (c
->lhs
.type
== DEREF
)
1071 any_change
= constraint_set_union (&graph
->complex[to
],
1072 &graph
->complex[from
]);
1073 graph
->complex[from
].release ();
1078 /* Remove edges involving NODE from GRAPH. */
1081 clear_edges_for_node (constraint_graph_t graph
, unsigned int node
)
1083 if (graph
->succs
[node
])
1084 BITMAP_FREE (graph
->succs
[node
]);
1087 /* Merge GRAPH nodes FROM and TO into node TO. */
1090 merge_graph_nodes (constraint_graph_t graph
, unsigned int to
,
1093 if (graph
->indirect_cycles
[from
] != -1)
1095 /* If we have indirect cycles with the from node, and we have
1096 none on the to node, the to node has indirect cycles from the
1097 from node now that they are unified.
1098 If indirect cycles exist on both, unify the nodes that they
1099 are in a cycle with, since we know they are in a cycle with
1101 if (graph
->indirect_cycles
[to
] == -1)
1102 graph
->indirect_cycles
[to
] = graph
->indirect_cycles
[from
];
1105 /* Merge all the successor edges. */
1106 if (graph
->succs
[from
])
1108 if (!graph
->succs
[to
])
1109 graph
->succs
[to
] = BITMAP_ALLOC (&pta_obstack
);
1110 bitmap_ior_into (graph
->succs
[to
],
1111 graph
->succs
[from
]);
1114 clear_edges_for_node (graph
, from
);
1118 /* Add an indirect graph edge to GRAPH, going from TO to FROM if
1119 it doesn't exist in the graph already. */
1122 add_implicit_graph_edge (constraint_graph_t graph
, unsigned int to
,
1128 if (!graph
->implicit_preds
[to
])
1129 graph
->implicit_preds
[to
] = BITMAP_ALLOC (&predbitmap_obstack
);
1131 if (bitmap_set_bit (graph
->implicit_preds
[to
], from
))
1132 stats
.num_implicit_edges
++;
1135 /* Add a predecessor graph edge to GRAPH, going from TO to FROM if
1136 it doesn't exist in the graph already.
1137 Return false if the edge already existed, true otherwise. */
1140 add_pred_graph_edge (constraint_graph_t graph
, unsigned int to
,
1143 if (!graph
->preds
[to
])
1144 graph
->preds
[to
] = BITMAP_ALLOC (&predbitmap_obstack
);
1145 bitmap_set_bit (graph
->preds
[to
], from
);
1148 /* Add a graph edge to GRAPH, going from FROM to TO if
1149 it doesn't exist in the graph already.
1150 Return false if the edge already existed, true otherwise. */
1153 add_graph_edge (constraint_graph_t graph
, unsigned int to
,
1164 if (!graph
->succs
[from
])
1165 graph
->succs
[from
] = BITMAP_ALLOC (&pta_obstack
);
1166 if (bitmap_set_bit (graph
->succs
[from
], to
))
1169 if (to
< FIRST_REF_NODE
&& from
< FIRST_REF_NODE
)
1177 /* Initialize the constraint graph structure to contain SIZE nodes. */
1180 init_graph (unsigned int size
)
1184 graph
= XCNEW (struct constraint_graph
);
1186 graph
->succs
= XCNEWVEC (bitmap
, graph
->size
);
1187 graph
->indirect_cycles
= XNEWVEC (int, graph
->size
);
1188 graph
->rep
= XNEWVEC (unsigned int, graph
->size
);
1189 /* ??? Macros do not support template types with multiple arguments,
1190 so we use a typedef to work around it. */
1191 typedef vec
<constraint_t
> vec_constraint_t_heap
;
1192 graph
->complex = XCNEWVEC (vec_constraint_t_heap
, size
);
1193 graph
->pe
= XCNEWVEC (unsigned int, graph
->size
);
1194 graph
->pe_rep
= XNEWVEC (int, graph
->size
);
1196 for (j
= 0; j
< graph
->size
; j
++)
1199 graph
->pe_rep
[j
] = -1;
1200 graph
->indirect_cycles
[j
] = -1;
1204 /* Build the constraint graph, adding only predecessor edges right now. */
1207 build_pred_graph (void)
1213 graph
->implicit_preds
= XCNEWVEC (bitmap
, graph
->size
);
1214 graph
->preds
= XCNEWVEC (bitmap
, graph
->size
);
1215 graph
->pointer_label
= XCNEWVEC (unsigned int, graph
->size
);
1216 graph
->loc_label
= XCNEWVEC (unsigned int, graph
->size
);
1217 graph
->pointed_by
= XCNEWVEC (bitmap
, graph
->size
);
1218 graph
->points_to
= XCNEWVEC (bitmap
, graph
->size
);
1219 graph
->eq_rep
= XNEWVEC (int, graph
->size
);
1220 graph
->direct_nodes
= sbitmap_alloc (graph
->size
);
1221 graph
->address_taken
= BITMAP_ALLOC (&predbitmap_obstack
);
1222 bitmap_clear (graph
->direct_nodes
);
1224 for (j
= 1; j
< FIRST_REF_NODE
; j
++)
1226 if (!get_varinfo (j
)->is_special_var
)
1227 bitmap_set_bit (graph
->direct_nodes
, j
);
1230 for (j
= 0; j
< graph
->size
; j
++)
1231 graph
->eq_rep
[j
] = -1;
1233 for (j
= 0; j
< varmap
.length (); j
++)
1234 graph
->indirect_cycles
[j
] = -1;
1236 FOR_EACH_VEC_ELT (constraints
, i
, c
)
1238 struct constraint_expr lhs
= c
->lhs
;
1239 struct constraint_expr rhs
= c
->rhs
;
1240 unsigned int lhsvar
= lhs
.var
;
1241 unsigned int rhsvar
= rhs
.var
;
1243 if (lhs
.type
== DEREF
)
1246 if (rhs
.offset
== 0 && lhs
.offset
== 0 && rhs
.type
== SCALAR
)
1247 add_pred_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1249 else if (rhs
.type
== DEREF
)
1252 if (rhs
.offset
== 0 && lhs
.offset
== 0 && lhs
.type
== SCALAR
)
1253 add_pred_graph_edge (graph
, lhsvar
, FIRST_REF_NODE
+ rhsvar
);
1255 bitmap_clear_bit (graph
->direct_nodes
, lhsvar
);
1257 else if (rhs
.type
== ADDRESSOF
)
1262 if (graph
->points_to
[lhsvar
] == NULL
)
1263 graph
->points_to
[lhsvar
] = BITMAP_ALLOC (&predbitmap_obstack
);
1264 bitmap_set_bit (graph
->points_to
[lhsvar
], rhsvar
);
1266 if (graph
->pointed_by
[rhsvar
] == NULL
)
1267 graph
->pointed_by
[rhsvar
] = BITMAP_ALLOC (&predbitmap_obstack
);
1268 bitmap_set_bit (graph
->pointed_by
[rhsvar
], lhsvar
);
1270 /* Implicitly, *x = y */
1271 add_implicit_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1273 /* All related variables are no longer direct nodes. */
1274 bitmap_clear_bit (graph
->direct_nodes
, rhsvar
);
1275 v
= get_varinfo (rhsvar
);
1276 if (!v
->is_full_var
)
1278 v
= get_varinfo (v
->head
);
1281 bitmap_clear_bit (graph
->direct_nodes
, v
->id
);
1286 bitmap_set_bit (graph
->address_taken
, rhsvar
);
1288 else if (lhsvar
> anything_id
1289 && lhsvar
!= rhsvar
&& lhs
.offset
== 0 && rhs
.offset
== 0)
1292 add_pred_graph_edge (graph
, lhsvar
, rhsvar
);
1293 /* Implicitly, *x = *y */
1294 add_implicit_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
,
1295 FIRST_REF_NODE
+ rhsvar
);
1297 else if (lhs
.offset
!= 0 || rhs
.offset
!= 0)
1299 if (rhs
.offset
!= 0)
1300 bitmap_clear_bit (graph
->direct_nodes
, lhs
.var
);
1301 else if (lhs
.offset
!= 0)
1302 bitmap_clear_bit (graph
->direct_nodes
, rhs
.var
);
1307 /* Build the constraint graph, adding successor edges. */
1310 build_succ_graph (void)
1315 FOR_EACH_VEC_ELT (constraints
, i
, c
)
1317 struct constraint_expr lhs
;
1318 struct constraint_expr rhs
;
1319 unsigned int lhsvar
;
1320 unsigned int rhsvar
;
1327 lhsvar
= find (lhs
.var
);
1328 rhsvar
= find (rhs
.var
);
1330 if (lhs
.type
== DEREF
)
1332 if (rhs
.offset
== 0 && lhs
.offset
== 0 && rhs
.type
== SCALAR
)
1333 add_graph_edge (graph
, FIRST_REF_NODE
+ lhsvar
, rhsvar
);
1335 else if (rhs
.type
== DEREF
)
1337 if (rhs
.offset
== 0 && lhs
.offset
== 0 && lhs
.type
== SCALAR
)
1338 add_graph_edge (graph
, lhsvar
, FIRST_REF_NODE
+ rhsvar
);
1340 else if (rhs
.type
== ADDRESSOF
)
1343 gcc_checking_assert (find (rhs
.var
) == rhs
.var
);
1344 bitmap_set_bit (get_varinfo (lhsvar
)->solution
, rhsvar
);
1346 else if (lhsvar
> anything_id
1347 && lhsvar
!= rhsvar
&& lhs
.offset
== 0 && rhs
.offset
== 0)
1349 add_graph_edge (graph
, lhsvar
, rhsvar
);
1353 /* Add edges from STOREDANYTHING to all non-direct nodes that can
1354 receive pointers. */
1355 t
= find (storedanything_id
);
1356 for (i
= integer_id
+ 1; i
< FIRST_REF_NODE
; ++i
)
1358 if (!bitmap_bit_p (graph
->direct_nodes
, i
)
1359 && get_varinfo (i
)->may_have_pointers
)
1360 add_graph_edge (graph
, find (i
), t
);
1363 /* Everything stored to ANYTHING also potentially escapes. */
1364 add_graph_edge (graph
, find (escaped_id
), t
);
1368 /* Changed variables on the last iteration. */
1369 static bitmap changed
;
1371 /* Strongly Connected Component visitation info. */
1378 unsigned int *node_mapping
;
1380 vec
<unsigned> scc_stack
;
1384 /* Recursive routine to find strongly connected components in GRAPH.
1385 SI is the SCC info to store the information in, and N is the id of current
1386 graph node we are processing.
1388 This is Tarjan's strongly connected component finding algorithm, as
1389 modified by Nuutila to keep only non-root nodes on the stack.
1390 The algorithm can be found in "On finding the strongly connected
1391 connected components in a directed graph" by Esko Nuutila and Eljas
1392 Soisalon-Soininen, in Information Processing Letters volume 49,
1393 number 1, pages 9-14. */
1396 scc_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
1400 unsigned int my_dfs
;
1402 bitmap_set_bit (si
->visited
, n
);
1403 si
->dfs
[n
] = si
->current_index
++;
1404 my_dfs
= si
->dfs
[n
];
1406 /* Visit all the successors. */
1407 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[n
], 0, i
, bi
)
1411 if (i
> LAST_REF_NODE
)
1415 if (bitmap_bit_p (si
->deleted
, w
))
1418 if (!bitmap_bit_p (si
->visited
, w
))
1419 scc_visit (graph
, si
, w
);
1421 unsigned int t
= find (w
);
1422 gcc_checking_assert (find (n
) == n
);
1423 if (si
->dfs
[t
] < si
->dfs
[n
])
1424 si
->dfs
[n
] = si
->dfs
[t
];
1427 /* See if any components have been identified. */
1428 if (si
->dfs
[n
] == my_dfs
)
1430 if (si
->scc_stack
.length () > 0
1431 && si
->dfs
[si
->scc_stack
.last ()] >= my_dfs
)
1433 bitmap scc
= BITMAP_ALLOC (NULL
);
1434 unsigned int lowest_node
;
1437 bitmap_set_bit (scc
, n
);
1439 while (si
->scc_stack
.length () != 0
1440 && si
->dfs
[si
->scc_stack
.last ()] >= my_dfs
)
1442 unsigned int w
= si
->scc_stack
.pop ();
1444 bitmap_set_bit (scc
, w
);
1447 lowest_node
= bitmap_first_set_bit (scc
);
1448 gcc_assert (lowest_node
< FIRST_REF_NODE
);
1450 /* Collapse the SCC nodes into a single node, and mark the
1452 EXECUTE_IF_SET_IN_BITMAP (scc
, 0, i
, bi
)
1454 if (i
< FIRST_REF_NODE
)
1456 if (unite (lowest_node
, i
))
1457 unify_nodes (graph
, lowest_node
, i
, false);
1461 unite (lowest_node
, i
);
1462 graph
->indirect_cycles
[i
- FIRST_REF_NODE
] = lowest_node
;
1466 bitmap_set_bit (si
->deleted
, n
);
1469 si
->scc_stack
.safe_push (n
);
1472 /* Unify node FROM into node TO, updating the changed count if
1473 necessary when UPDATE_CHANGED is true. */
1476 unify_nodes (constraint_graph_t graph
, unsigned int to
, unsigned int from
,
1477 bool update_changed
)
1479 gcc_checking_assert (to
!= from
&& find (to
) == to
);
1481 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1482 fprintf (dump_file
, "Unifying %s to %s\n",
1483 get_varinfo (from
)->name
,
1484 get_varinfo (to
)->name
);
1487 stats
.unified_vars_dynamic
++;
1489 stats
.unified_vars_static
++;
1491 merge_graph_nodes (graph
, to
, from
);
1492 if (merge_node_constraints (graph
, to
, from
))
1495 bitmap_set_bit (changed
, to
);
1498 /* Mark TO as changed if FROM was changed. If TO was already marked
1499 as changed, decrease the changed count. */
1502 && bitmap_clear_bit (changed
, from
))
1503 bitmap_set_bit (changed
, to
);
1504 varinfo_t fromvi
= get_varinfo (from
);
1505 if (fromvi
->solution
)
1507 /* If the solution changes because of the merging, we need to mark
1508 the variable as changed. */
1509 varinfo_t tovi
= get_varinfo (to
);
1510 if (bitmap_ior_into (tovi
->solution
, fromvi
->solution
))
1513 bitmap_set_bit (changed
, to
);
1516 BITMAP_FREE (fromvi
->solution
);
1517 if (fromvi
->oldsolution
)
1518 BITMAP_FREE (fromvi
->oldsolution
);
1520 if (stats
.iterations
> 0
1521 && tovi
->oldsolution
)
1522 BITMAP_FREE (tovi
->oldsolution
);
1524 if (graph
->succs
[to
])
1525 bitmap_clear_bit (graph
->succs
[to
], to
);
1528 /* Information needed to compute the topological ordering of a graph. */
1532 /* sbitmap of visited nodes. */
1534 /* Array that stores the topological order of the graph, *in
1536 vec
<unsigned> topo_order
;
1540 /* Initialize and return a topological info structure. */
1542 static struct topo_info
*
1543 init_topo_info (void)
1545 size_t size
= graph
->size
;
1546 struct topo_info
*ti
= XNEW (struct topo_info
);
1547 ti
->visited
= sbitmap_alloc (size
);
1548 bitmap_clear (ti
->visited
);
1549 ti
->topo_order
.create (1);
1554 /* Free the topological sort info pointed to by TI. */
1557 free_topo_info (struct topo_info
*ti
)
1559 sbitmap_free (ti
->visited
);
1560 ti
->topo_order
.release ();
1564 /* Visit the graph in topological order, and store the order in the
1565 topo_info structure. */
1568 topo_visit (constraint_graph_t graph
, struct topo_info
*ti
,
1574 bitmap_set_bit (ti
->visited
, n
);
1576 if (graph
->succs
[n
])
1577 EXECUTE_IF_SET_IN_BITMAP (graph
->succs
[n
], 0, j
, bi
)
1579 if (!bitmap_bit_p (ti
->visited
, j
))
1580 topo_visit (graph
, ti
, j
);
1583 ti
->topo_order
.safe_push (n
);
1586 /* Process a constraint C that represents x = *(y + off), using DELTA as the
1587 starting solution for y. */
1590 do_sd_constraint (constraint_graph_t graph
, constraint_t c
,
1591 bitmap delta
, bitmap
*expanded_delta
)
1593 unsigned int lhs
= c
->lhs
.var
;
1595 bitmap sol
= get_varinfo (lhs
)->solution
;
1598 HOST_WIDE_INT roffset
= c
->rhs
.offset
;
1600 /* Our IL does not allow this. */
1601 gcc_checking_assert (c
->lhs
.offset
== 0);
1603 /* If the solution of Y contains anything it is good enough to transfer
1605 if (bitmap_bit_p (delta
, anything_id
))
1607 flag
|= bitmap_set_bit (sol
, anything_id
);
1611 /* If we do not know at with offset the rhs is dereferenced compute
1612 the reachability set of DELTA, conservatively assuming it is
1613 dereferenced at all valid offsets. */
1614 if (roffset
== UNKNOWN_OFFSET
)
1616 delta
= solution_set_expand (delta
, expanded_delta
);
1617 /* No further offset processing is necessary. */
1621 /* For each variable j in delta (Sol(y)), add
1622 an edge in the graph from j to x, and union Sol(j) into Sol(x). */
1623 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, j
, bi
)
1625 varinfo_t v
= get_varinfo (j
);
1626 HOST_WIDE_INT fieldoffset
= v
->offset
+ roffset
;
1627 unsigned HOST_WIDE_INT size
= v
->size
;
1632 else if (roffset
!= 0)
1634 if (fieldoffset
< 0)
1635 v
= get_varinfo (v
->head
);
1637 v
= first_or_preceding_vi_for_offset (v
, fieldoffset
);
1640 /* We have to include all fields that overlap the current field
1641 shifted by roffset. */
1646 /* Adding edges from the special vars is pointless.
1647 They don't have sets that can change. */
1648 if (get_varinfo (t
)->is_special_var
)
1649 flag
|= bitmap_ior_into (sol
, get_varinfo (t
)->solution
);
1650 /* Merging the solution from ESCAPED needlessly increases
1651 the set. Use ESCAPED as representative instead. */
1652 else if (v
->id
== escaped_id
)
1653 flag
|= bitmap_set_bit (sol
, escaped_id
);
1654 else if (v
->may_have_pointers
1655 && add_graph_edge (graph
, lhs
, t
))
1656 flag
|= bitmap_ior_into (sol
, get_varinfo (t
)->solution
);
1664 while (v
->offset
< fieldoffset
+ size
);
1668 /* If the LHS solution changed, mark the var as changed. */
1671 get_varinfo (lhs
)->solution
= sol
;
1672 bitmap_set_bit (changed
, lhs
);
1676 /* Process a constraint C that represents *(x + off) = y using DELTA
1677 as the starting solution for x. */
1680 do_ds_constraint (constraint_t c
, bitmap delta
, bitmap
*expanded_delta
)
1682 unsigned int rhs
= c
->rhs
.var
;
1683 bitmap sol
= get_varinfo (rhs
)->solution
;
1686 HOST_WIDE_INT loff
= c
->lhs
.offset
;
1687 bool escaped_p
= false;
1689 /* Our IL does not allow this. */
1690 gcc_checking_assert (c
->rhs
.offset
== 0);
1692 /* If the solution of y contains ANYTHING simply use the ANYTHING
1693 solution. This avoids needlessly increasing the points-to sets. */
1694 if (bitmap_bit_p (sol
, anything_id
))
1695 sol
= get_varinfo (find (anything_id
))->solution
;
1697 /* If the solution for x contains ANYTHING we have to merge the
1698 solution of y into all pointer variables which we do via
1700 if (bitmap_bit_p (delta
, anything_id
))
1702 unsigned t
= find (storedanything_id
);
1703 if (add_graph_edge (graph
, t
, rhs
))
1705 if (bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1706 bitmap_set_bit (changed
, t
);
1711 /* If we do not know at with offset the rhs is dereferenced compute
1712 the reachability set of DELTA, conservatively assuming it is
1713 dereferenced at all valid offsets. */
1714 if (loff
== UNKNOWN_OFFSET
)
1716 delta
= solution_set_expand (delta
, expanded_delta
);
1720 /* For each member j of delta (Sol(x)), add an edge from y to j and
1721 union Sol(y) into Sol(j) */
1722 EXECUTE_IF_SET_IN_BITMAP (delta
, 0, j
, bi
)
1724 varinfo_t v
= get_varinfo (j
);
1726 HOST_WIDE_INT fieldoffset
= v
->offset
+ loff
;
1727 unsigned HOST_WIDE_INT size
= v
->size
;
1733 if (fieldoffset
< 0)
1734 v
= get_varinfo (v
->head
);
1736 v
= first_or_preceding_vi_for_offset (v
, fieldoffset
);
1739 /* We have to include all fields that overlap the current field
1743 if (v
->may_have_pointers
)
1745 /* If v is a global variable then this is an escape point. */
1746 if (v
->is_global_var
1749 t
= find (escaped_id
);
1750 if (add_graph_edge (graph
, t
, rhs
)
1751 && bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1752 bitmap_set_bit (changed
, t
);
1753 /* Enough to let rhs escape once. */
1757 if (v
->is_special_var
)
1761 if (add_graph_edge (graph
, t
, rhs
)
1762 && bitmap_ior_into (get_varinfo (t
)->solution
, sol
))
1763 bitmap_set_bit (changed
, t
);
1772 while (v
->offset
< fieldoffset
+ size
);
1776 /* Handle a non-simple (simple meaning requires no iteration),
1777 constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
1780 do_complex_constraint (constraint_graph_t graph
, constraint_t c
, bitmap delta
,
1781 bitmap
*expanded_delta
)
1783 if (c
->lhs
.type
== DEREF
)
1785 if (c
->rhs
.type
== ADDRESSOF
)
1792 do_ds_constraint (c
, delta
, expanded_delta
);
1795 else if (c
->rhs
.type
== DEREF
)
1798 if (!(get_varinfo (c
->lhs
.var
)->is_special_var
))
1799 do_sd_constraint (graph
, c
, delta
, expanded_delta
);
1806 gcc_checking_assert (c
->rhs
.type
== SCALAR
&& c
->lhs
.type
== SCALAR
1807 && c
->rhs
.offset
!= 0 && c
->lhs
.offset
== 0);
1808 tmp
= get_varinfo (c
->lhs
.var
)->solution
;
1810 flag
= set_union_with_increment (tmp
, delta
, c
->rhs
.offset
,
1814 bitmap_set_bit (changed
, c
->lhs
.var
);
1818 /* Initialize and return a new SCC info structure. */
1820 static struct scc_info
*
1821 init_scc_info (size_t size
)
1823 struct scc_info
*si
= XNEW (struct scc_info
);
1826 si
->current_index
= 0;
1827 si
->visited
= sbitmap_alloc (size
);
1828 bitmap_clear (si
->visited
);
1829 si
->deleted
= sbitmap_alloc (size
);
1830 bitmap_clear (si
->deleted
);
1831 si
->node_mapping
= XNEWVEC (unsigned int, size
);
1832 si
->dfs
= XCNEWVEC (unsigned int, size
);
1834 for (i
= 0; i
< size
; i
++)
1835 si
->node_mapping
[i
] = i
;
1837 si
->scc_stack
.create (1);
1841 /* Free an SCC info structure pointed to by SI */
1844 free_scc_info (struct scc_info
*si
)
1846 sbitmap_free (si
->visited
);
1847 sbitmap_free (si
->deleted
);
1848 free (si
->node_mapping
);
1850 si
->scc_stack
.release ();
1855 /* Find indirect cycles in GRAPH that occur, using strongly connected
1856 components, and note them in the indirect cycles map.
1858 This technique comes from Ben Hardekopf and Calvin Lin,
1859 "It Pays to be Lazy: Fast and Accurate Pointer Analysis for Millions of
1860 Lines of Code", submitted to PLDI 2007. */
1863 find_indirect_cycles (constraint_graph_t graph
)
1866 unsigned int size
= graph
->size
;
1867 struct scc_info
*si
= init_scc_info (size
);
1869 for (i
= 0; i
< MIN (LAST_REF_NODE
, size
); i
++ )
1870 if (!bitmap_bit_p (si
->visited
, i
) && find (i
) == i
)
1871 scc_visit (graph
, si
, i
);
1876 /* Compute a topological ordering for GRAPH, and store the result in the
1877 topo_info structure TI. */
1880 compute_topo_order (constraint_graph_t graph
,
1881 struct topo_info
*ti
)
1884 unsigned int size
= graph
->size
;
1886 for (i
= 0; i
!= size
; ++i
)
1887 if (!bitmap_bit_p (ti
->visited
, i
) && find (i
) == i
)
1888 topo_visit (graph
, ti
, i
);
1891 /* Structure used to for hash value numbering of pointer equivalence
1894 typedef struct equiv_class_label
1897 unsigned int equivalence_class
;
1899 } *equiv_class_label_t
;
1900 typedef const struct equiv_class_label
*const_equiv_class_label_t
;
1902 /* Equiv_class_label hashtable helpers. */
1904 struct equiv_class_hasher
: free_ptr_hash
<equiv_class_label
>
1906 static inline hashval_t
hash (const equiv_class_label
*);
1907 static inline bool equal (const equiv_class_label
*,
1908 const equiv_class_label
*);
1911 /* Hash function for a equiv_class_label_t */
1914 equiv_class_hasher::hash (const equiv_class_label
*ecl
)
1916 return ecl
->hashcode
;
1919 /* Equality function for two equiv_class_label_t's. */
1922 equiv_class_hasher::equal (const equiv_class_label
*eql1
,
1923 const equiv_class_label
*eql2
)
1925 return (eql1
->hashcode
== eql2
->hashcode
1926 && bitmap_equal_p (eql1
->labels
, eql2
->labels
));
1929 /* A hashtable for mapping a bitmap of labels->pointer equivalence
1931 static hash_table
<equiv_class_hasher
> *pointer_equiv_class_table
;
1933 /* A hashtable for mapping a bitmap of labels->location equivalence
1935 static hash_table
<equiv_class_hasher
> *location_equiv_class_table
;
1937 /* Lookup a equivalence class in TABLE by the bitmap of LABELS with
1938 hash HAS it contains. Sets *REF_LABELS to the bitmap LABELS
1939 is equivalent to. */
1941 static equiv_class_label
*
1942 equiv_class_lookup_or_add (hash_table
<equiv_class_hasher
> *table
,
1945 equiv_class_label
**slot
;
1946 equiv_class_label ecl
;
1948 ecl
.labels
= labels
;
1949 ecl
.hashcode
= bitmap_hash (labels
);
1950 slot
= table
->find_slot (&ecl
, INSERT
);
1953 *slot
= XNEW (struct equiv_class_label
);
1954 (*slot
)->labels
= labels
;
1955 (*slot
)->hashcode
= ecl
.hashcode
;
1956 (*slot
)->equivalence_class
= 0;
1962 /* Perform offline variable substitution.
1964 This is a worst case quadratic time way of identifying variables
1965 that must have equivalent points-to sets, including those caused by
1966 static cycles, and single entry subgraphs, in the constraint graph.
1968 The technique is described in "Exploiting Pointer and Location
1969 Equivalence to Optimize Pointer Analysis. In the 14th International
1970 Static Analysis Symposium (SAS), August 2007." It is known as the
1971 "HU" algorithm, and is equivalent to value numbering the collapsed
1972 constraint graph including evaluating unions.
1974 The general method of finding equivalence classes is as follows:
1975 Add fake nodes (REF nodes) and edges for *a = b and a = *b constraints.
1976 Initialize all non-REF nodes to be direct nodes.
1977 For each constraint a = a U {b}, we set pts(a) = pts(a) u {fresh
1979 For each constraint containing the dereference, we also do the same
1982 We then compute SCC's in the graph and unify nodes in the same SCC,
1985 For each non-collapsed node x:
1986 Visit all unvisited explicit incoming edges.
1987 Ignoring all non-pointers, set pts(x) = Union of pts(a) for y
1989 Lookup the equivalence class for pts(x).
1990 If we found one, equivalence_class(x) = found class.
1991 Otherwise, equivalence_class(x) = new class, and new_class is
1992 added to the lookup table.
1994 All direct nodes with the same equivalence class can be replaced
1995 with a single representative node.
1996 All unlabeled nodes (label == 0) are not pointers and all edges
1997 involving them can be eliminated.
1998 We perform these optimizations during rewrite_constraints
2000 In addition to pointer equivalence class finding, we also perform
2001 location equivalence class finding. This is the set of variables
2002 that always appear together in points-to sets. We use this to
2003 compress the size of the points-to sets. */
2005 /* Current maximum pointer equivalence class id. */
2006 static int pointer_equiv_class
;
2008 /* Current maximum location equivalence class id. */
2009 static int location_equiv_class
;
2011 /* Recursive routine to find strongly connected components in GRAPH,
2012 and label it's nodes with DFS numbers. */
2015 condense_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
2019 unsigned int my_dfs
;
2021 gcc_checking_assert (si
->node_mapping
[n
] == n
);
2022 bitmap_set_bit (si
->visited
, n
);
2023 si
->dfs
[n
] = si
->current_index
++;
2024 my_dfs
= si
->dfs
[n
];
2026 /* Visit all the successors. */
2027 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[n
], 0, i
, bi
)
2029 unsigned int w
= si
->node_mapping
[i
];
2031 if (bitmap_bit_p (si
->deleted
, w
))
2034 if (!bitmap_bit_p (si
->visited
, w
))
2035 condense_visit (graph
, si
, w
);
2037 unsigned int t
= si
->node_mapping
[w
];
2038 gcc_checking_assert (si
->node_mapping
[n
] == n
);
2039 if (si
->dfs
[t
] < si
->dfs
[n
])
2040 si
->dfs
[n
] = si
->dfs
[t
];
2043 /* Visit all the implicit predecessors. */
2044 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->implicit_preds
[n
], 0, i
, bi
)
2046 unsigned int w
= si
->node_mapping
[i
];
2048 if (bitmap_bit_p (si
->deleted
, w
))
2051 if (!bitmap_bit_p (si
->visited
, w
))
2052 condense_visit (graph
, si
, w
);
2054 unsigned int t
= si
->node_mapping
[w
];
2055 gcc_assert (si
->node_mapping
[n
] == n
);
2056 if (si
->dfs
[t
] < si
->dfs
[n
])
2057 si
->dfs
[n
] = si
->dfs
[t
];
2060 /* See if any components have been identified. */
2061 if (si
->dfs
[n
] == my_dfs
)
2063 while (si
->scc_stack
.length () != 0
2064 && si
->dfs
[si
->scc_stack
.last ()] >= my_dfs
)
2066 unsigned int w
= si
->scc_stack
.pop ();
2067 si
->node_mapping
[w
] = n
;
2069 if (!bitmap_bit_p (graph
->direct_nodes
, w
))
2070 bitmap_clear_bit (graph
->direct_nodes
, n
);
2072 /* Unify our nodes. */
2073 if (graph
->preds
[w
])
2075 if (!graph
->preds
[n
])
2076 graph
->preds
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2077 bitmap_ior_into (graph
->preds
[n
], graph
->preds
[w
]);
2079 if (graph
->implicit_preds
[w
])
2081 if (!graph
->implicit_preds
[n
])
2082 graph
->implicit_preds
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2083 bitmap_ior_into (graph
->implicit_preds
[n
],
2084 graph
->implicit_preds
[w
]);
2086 if (graph
->points_to
[w
])
2088 if (!graph
->points_to
[n
])
2089 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2090 bitmap_ior_into (graph
->points_to
[n
],
2091 graph
->points_to
[w
]);
2094 bitmap_set_bit (si
->deleted
, n
);
2097 si
->scc_stack
.safe_push (n
);
2100 /* Label pointer equivalences.
2102 This performs a value numbering of the constraint graph to
2103 discover which variables will always have the same points-to sets
2104 under the current set of constraints.
2106 The way it value numbers is to store the set of points-to bits
2107 generated by the constraints and graph edges. This is just used as a
2108 hash and equality comparison. The *actual set of points-to bits* is
2109 completely irrelevant, in that we don't care about being able to
2112 The equality values (currently bitmaps) just have to satisfy a few
2113 constraints, the main ones being:
2114 1. The combining operation must be order independent.
2115 2. The end result of a given set of operations must be unique iff the
2116 combination of input values is unique
2120 label_visit (constraint_graph_t graph
, struct scc_info
*si
, unsigned int n
)
2122 unsigned int i
, first_pred
;
2125 bitmap_set_bit (si
->visited
, n
);
2127 /* Label and union our incoming edges's points to sets. */
2129 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[n
], 0, i
, bi
)
2131 unsigned int w
= si
->node_mapping
[i
];
2132 if (!bitmap_bit_p (si
->visited
, w
))
2133 label_visit (graph
, si
, w
);
2135 /* Skip unused edges */
2136 if (w
== n
|| graph
->pointer_label
[w
] == 0)
2139 if (graph
->points_to
[w
])
2141 if (!graph
->points_to
[n
])
2143 if (first_pred
== -1U)
2147 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2148 bitmap_ior (graph
->points_to
[n
],
2149 graph
->points_to
[first_pred
],
2150 graph
->points_to
[w
]);
2154 bitmap_ior_into (graph
->points_to
[n
], graph
->points_to
[w
]);
2158 /* Indirect nodes get fresh variables and a new pointer equiv class. */
2159 if (!bitmap_bit_p (graph
->direct_nodes
, n
))
2161 if (!graph
->points_to
[n
])
2163 graph
->points_to
[n
] = BITMAP_ALLOC (&predbitmap_obstack
);
2164 if (first_pred
!= -1U)
2165 bitmap_copy (graph
->points_to
[n
], graph
->points_to
[first_pred
]);
2167 bitmap_set_bit (graph
->points_to
[n
], FIRST_REF_NODE
+ n
);
2168 graph
->pointer_label
[n
] = pointer_equiv_class
++;
2169 equiv_class_label_t ecl
;
2170 ecl
= equiv_class_lookup_or_add (pointer_equiv_class_table
,
2171 graph
->points_to
[n
]);
2172 ecl
->equivalence_class
= graph
->pointer_label
[n
];
2176 /* If there was only a single non-empty predecessor the pointer equiv
2177 class is the same. */
2178 if (!graph
->points_to
[n
])
2180 if (first_pred
!= -1U)
2182 graph
->pointer_label
[n
] = graph
->pointer_label
[first_pred
];
2183 graph
->points_to
[n
] = graph
->points_to
[first_pred
];
2188 if (!bitmap_empty_p (graph
->points_to
[n
]))
2190 equiv_class_label_t ecl
;
2191 ecl
= equiv_class_lookup_or_add (pointer_equiv_class_table
,
2192 graph
->points_to
[n
]);
2193 if (ecl
->equivalence_class
== 0)
2194 ecl
->equivalence_class
= pointer_equiv_class
++;
2197 BITMAP_FREE (graph
->points_to
[n
]);
2198 graph
->points_to
[n
] = ecl
->labels
;
2200 graph
->pointer_label
[n
] = ecl
->equivalence_class
;
2204 /* Print the pred graph in dot format. */
2207 dump_pred_graph (struct scc_info
*si
, FILE *file
)
2211 /* Only print the graph if it has already been initialized: */
2215 /* Prints the header of the dot file: */
2216 fprintf (file
, "strict digraph {\n");
2217 fprintf (file
, " node [\n shape = box\n ]\n");
2218 fprintf (file
, " edge [\n fontsize = \"12\"\n ]\n");
2219 fprintf (file
, "\n // List of nodes and complex constraints in "
2220 "the constraint graph:\n");
2222 /* The next lines print the nodes in the graph together with the
2223 complex constraints attached to them. */
2224 for (i
= 1; i
< graph
->size
; i
++)
2226 if (i
== FIRST_REF_NODE
)
2228 if (si
->node_mapping
[i
] != i
)
2230 if (i
< FIRST_REF_NODE
)
2231 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
2233 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
2234 if (graph
->points_to
[i
]
2235 && !bitmap_empty_p (graph
->points_to
[i
]))
2237 fprintf (file
, "[label=\"%s = {", get_varinfo (i
)->name
);
2240 EXECUTE_IF_SET_IN_BITMAP (graph
->points_to
[i
], 0, j
, bi
)
2241 fprintf (file
, " %d", j
);
2242 fprintf (file
, " }\"]");
2244 fprintf (file
, ";\n");
2247 /* Go over the edges. */
2248 fprintf (file
, "\n // Edges in the constraint graph:\n");
2249 for (i
= 1; i
< graph
->size
; i
++)
2253 if (si
->node_mapping
[i
] != i
)
2255 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->preds
[i
], 0, j
, bi
)
2257 unsigned from
= si
->node_mapping
[j
];
2258 if (from
< FIRST_REF_NODE
)
2259 fprintf (file
, "\"%s\"", get_varinfo (from
)->name
);
2261 fprintf (file
, "\"*%s\"", get_varinfo (from
- FIRST_REF_NODE
)->name
);
2262 fprintf (file
, " -> ");
2263 if (i
< FIRST_REF_NODE
)
2264 fprintf (file
, "\"%s\"", get_varinfo (i
)->name
);
2266 fprintf (file
, "\"*%s\"", get_varinfo (i
- FIRST_REF_NODE
)->name
);
2267 fprintf (file
, ";\n");
2271 /* Prints the tail of the dot file. */
2272 fprintf (file
, "}\n");
2275 /* Perform offline variable substitution, discovering equivalence
2276 classes, and eliminating non-pointer variables. */
2278 static struct scc_info
*
2279 perform_var_substitution (constraint_graph_t graph
)
2282 unsigned int size
= graph
->size
;
2283 struct scc_info
*si
= init_scc_info (size
);
2285 bitmap_obstack_initialize (&iteration_obstack
);
2286 pointer_equiv_class_table
= new hash_table
<equiv_class_hasher
> (511);
2287 location_equiv_class_table
2288 = new hash_table
<equiv_class_hasher
> (511);
2289 pointer_equiv_class
= 1;
2290 location_equiv_class
= 1;
2292 /* Condense the nodes, which means to find SCC's, count incoming
2293 predecessors, and unite nodes in SCC's. */
2294 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2295 if (!bitmap_bit_p (si
->visited
, si
->node_mapping
[i
]))
2296 condense_visit (graph
, si
, si
->node_mapping
[i
]);
2298 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
2300 fprintf (dump_file
, "\n\n// The constraint graph before var-substitution "
2301 "in dot format:\n");
2302 dump_pred_graph (si
, dump_file
);
2303 fprintf (dump_file
, "\n\n");
2306 bitmap_clear (si
->visited
);
2307 /* Actually the label the nodes for pointer equivalences */
2308 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2309 if (!bitmap_bit_p (si
->visited
, si
->node_mapping
[i
]))
2310 label_visit (graph
, si
, si
->node_mapping
[i
]);
2312 /* Calculate location equivalence labels. */
2313 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2319 if (!graph
->pointed_by
[i
])
2321 pointed_by
= BITMAP_ALLOC (&iteration_obstack
);
2323 /* Translate the pointed-by mapping for pointer equivalence
2325 EXECUTE_IF_SET_IN_BITMAP (graph
->pointed_by
[i
], 0, j
, bi
)
2327 bitmap_set_bit (pointed_by
,
2328 graph
->pointer_label
[si
->node_mapping
[j
]]);
2330 /* The original pointed_by is now dead. */
2331 BITMAP_FREE (graph
->pointed_by
[i
]);
2333 /* Look up the location equivalence label if one exists, or make
2335 equiv_class_label_t ecl
;
2336 ecl
= equiv_class_lookup_or_add (location_equiv_class_table
, pointed_by
);
2337 if (ecl
->equivalence_class
== 0)
2338 ecl
->equivalence_class
= location_equiv_class
++;
2341 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2342 fprintf (dump_file
, "Found location equivalence for node %s\n",
2343 get_varinfo (i
)->name
);
2344 BITMAP_FREE (pointed_by
);
2346 graph
->loc_label
[i
] = ecl
->equivalence_class
;
2350 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2351 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2353 unsigned j
= si
->node_mapping
[i
];
2356 fprintf (dump_file
, "%s node id %d ",
2357 bitmap_bit_p (graph
->direct_nodes
, i
)
2358 ? "Direct" : "Indirect", i
);
2359 if (i
< FIRST_REF_NODE
)
2360 fprintf (dump_file
, "\"%s\"", get_varinfo (i
)->name
);
2362 fprintf (dump_file
, "\"*%s\"",
2363 get_varinfo (i
- FIRST_REF_NODE
)->name
);
2364 fprintf (dump_file
, " mapped to SCC leader node id %d ", j
);
2365 if (j
< FIRST_REF_NODE
)
2366 fprintf (dump_file
, "\"%s\"\n", get_varinfo (j
)->name
);
2368 fprintf (dump_file
, "\"*%s\"\n",
2369 get_varinfo (j
- FIRST_REF_NODE
)->name
);
2374 "Equivalence classes for %s node id %d ",
2375 bitmap_bit_p (graph
->direct_nodes
, i
)
2376 ? "direct" : "indirect", i
);
2377 if (i
< FIRST_REF_NODE
)
2378 fprintf (dump_file
, "\"%s\"", get_varinfo (i
)->name
);
2380 fprintf (dump_file
, "\"*%s\"",
2381 get_varinfo (i
- FIRST_REF_NODE
)->name
);
2383 ": pointer %d, location %d\n",
2384 graph
->pointer_label
[i
], graph
->loc_label
[i
]);
2388 /* Quickly eliminate our non-pointer variables. */
2390 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2392 unsigned int node
= si
->node_mapping
[i
];
2394 if (graph
->pointer_label
[node
] == 0)
2396 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2398 "%s is a non-pointer variable, eliminating edges.\n",
2399 get_varinfo (node
)->name
);
2400 stats
.nonpointer_vars
++;
2401 clear_edges_for_node (graph
, node
);
2408 /* Free information that was only necessary for variable
2412 free_var_substitution_info (struct scc_info
*si
)
2415 free (graph
->pointer_label
);
2416 free (graph
->loc_label
);
2417 free (graph
->pointed_by
);
2418 free (graph
->points_to
);
2419 free (graph
->eq_rep
);
2420 sbitmap_free (graph
->direct_nodes
);
2421 delete pointer_equiv_class_table
;
2422 pointer_equiv_class_table
= NULL
;
2423 delete location_equiv_class_table
;
2424 location_equiv_class_table
= NULL
;
2425 bitmap_obstack_release (&iteration_obstack
);
2428 /* Return an existing node that is equivalent to NODE, which has
2429 equivalence class LABEL, if one exists. Return NODE otherwise. */
2432 find_equivalent_node (constraint_graph_t graph
,
2433 unsigned int node
, unsigned int label
)
2435 /* If the address version of this variable is unused, we can
2436 substitute it for anything else with the same label.
2437 Otherwise, we know the pointers are equivalent, but not the
2438 locations, and we can unite them later. */
2440 if (!bitmap_bit_p (graph
->address_taken
, node
))
2442 gcc_checking_assert (label
< graph
->size
);
2444 if (graph
->eq_rep
[label
] != -1)
2446 /* Unify the two variables since we know they are equivalent. */
2447 if (unite (graph
->eq_rep
[label
], node
))
2448 unify_nodes (graph
, graph
->eq_rep
[label
], node
, false);
2449 return graph
->eq_rep
[label
];
2453 graph
->eq_rep
[label
] = node
;
2454 graph
->pe_rep
[label
] = node
;
2459 gcc_checking_assert (label
< graph
->size
);
2460 graph
->pe
[node
] = label
;
2461 if (graph
->pe_rep
[label
] == -1)
2462 graph
->pe_rep
[label
] = node
;
2468 /* Unite pointer equivalent but not location equivalent nodes in
2469 GRAPH. This may only be performed once variable substitution is
2473 unite_pointer_equivalences (constraint_graph_t graph
)
2477 /* Go through the pointer equivalences and unite them to their
2478 representative, if they aren't already. */
2479 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
2481 unsigned int label
= graph
->pe
[i
];
2484 int label_rep
= graph
->pe_rep
[label
];
2486 if (label_rep
== -1)
2489 label_rep
= find (label_rep
);
2490 if (label_rep
>= 0 && unite (label_rep
, find (i
)))
2491 unify_nodes (graph
, label_rep
, i
, false);
2496 /* Move complex constraints to the GRAPH nodes they belong to. */
2499 move_complex_constraints (constraint_graph_t graph
)
2504 FOR_EACH_VEC_ELT (constraints
, i
, c
)
2508 struct constraint_expr lhs
= c
->lhs
;
2509 struct constraint_expr rhs
= c
->rhs
;
2511 if (lhs
.type
== DEREF
)
2513 insert_into_complex (graph
, lhs
.var
, c
);
2515 else if (rhs
.type
== DEREF
)
2517 if (!(get_varinfo (lhs
.var
)->is_special_var
))
2518 insert_into_complex (graph
, rhs
.var
, c
);
2520 else if (rhs
.type
!= ADDRESSOF
&& lhs
.var
> anything_id
2521 && (lhs
.offset
!= 0 || rhs
.offset
!= 0))
2523 insert_into_complex (graph
, rhs
.var
, c
);
2530 /* Optimize and rewrite complex constraints while performing
2531 collapsing of equivalent nodes. SI is the SCC_INFO that is the
2532 result of perform_variable_substitution. */
2535 rewrite_constraints (constraint_graph_t graph
,
2536 struct scc_info
*si
)
2543 for (unsigned int j
= 0; j
< graph
->size
; j
++)
2544 gcc_assert (find (j
) == j
);
2547 FOR_EACH_VEC_ELT (constraints
, i
, c
)
2549 struct constraint_expr lhs
= c
->lhs
;
2550 struct constraint_expr rhs
= c
->rhs
;
2551 unsigned int lhsvar
= find (lhs
.var
);
2552 unsigned int rhsvar
= find (rhs
.var
);
2553 unsigned int lhsnode
, rhsnode
;
2554 unsigned int lhslabel
, rhslabel
;
2556 lhsnode
= si
->node_mapping
[lhsvar
];
2557 rhsnode
= si
->node_mapping
[rhsvar
];
2558 lhslabel
= graph
->pointer_label
[lhsnode
];
2559 rhslabel
= graph
->pointer_label
[rhsnode
];
2561 /* See if it is really a non-pointer variable, and if so, ignore
2565 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2568 fprintf (dump_file
, "%s is a non-pointer variable,"
2569 "ignoring constraint:",
2570 get_varinfo (lhs
.var
)->name
);
2571 dump_constraint (dump_file
, c
);
2572 fprintf (dump_file
, "\n");
2574 constraints
[i
] = NULL
;
2580 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
2583 fprintf (dump_file
, "%s is a non-pointer variable,"
2584 "ignoring constraint:",
2585 get_varinfo (rhs
.var
)->name
);
2586 dump_constraint (dump_file
, c
);
2587 fprintf (dump_file
, "\n");
2589 constraints
[i
] = NULL
;
2593 lhsvar
= find_equivalent_node (graph
, lhsvar
, lhslabel
);
2594 rhsvar
= find_equivalent_node (graph
, rhsvar
, rhslabel
);
2595 c
->lhs
.var
= lhsvar
;
2596 c
->rhs
.var
= rhsvar
;
2600 /* Eliminate indirect cycles involving NODE. Return true if NODE was
2601 part of an SCC, false otherwise. */
2604 eliminate_indirect_cycles (unsigned int node
)
2606 if (graph
->indirect_cycles
[node
] != -1
2607 && !bitmap_empty_p (get_varinfo (node
)->solution
))
2610 auto_vec
<unsigned> queue
;
2612 unsigned int to
= find (graph
->indirect_cycles
[node
]);
2615 /* We can't touch the solution set and call unify_nodes
2616 at the same time, because unify_nodes is going to do
2617 bitmap unions into it. */
2619 EXECUTE_IF_SET_IN_BITMAP (get_varinfo (node
)->solution
, 0, i
, bi
)
2621 if (find (i
) == i
&& i
!= to
)
2624 queue
.safe_push (i
);
2629 queue
.iterate (queuepos
, &i
);
2632 unify_nodes (graph
, to
, i
, true);
2639 /* Solve the constraint graph GRAPH using our worklist solver.
2640 This is based on the PW* family of solvers from the "Efficient Field
2641 Sensitive Pointer Analysis for C" paper.
2642 It works by iterating over all the graph nodes, processing the complex
2643 constraints and propagating the copy constraints, until everything stops
2644 changed. This corresponds to steps 6-8 in the solving list given above. */
2647 solve_graph (constraint_graph_t graph
)
2649 unsigned int size
= graph
->size
;
2653 changed
= BITMAP_ALLOC (NULL
);
2655 /* Mark all initial non-collapsed nodes as changed. */
2656 for (i
= 1; i
< size
; i
++)
2658 varinfo_t ivi
= get_varinfo (i
);
2659 if (find (i
) == i
&& !bitmap_empty_p (ivi
->solution
)
2660 && ((graph
->succs
[i
] && !bitmap_empty_p (graph
->succs
[i
]))
2661 || graph
->complex[i
].length () > 0))
2662 bitmap_set_bit (changed
, i
);
2665 /* Allocate a bitmap to be used to store the changed bits. */
2666 pts
= BITMAP_ALLOC (&pta_obstack
);
2668 while (!bitmap_empty_p (changed
))
2671 struct topo_info
*ti
= init_topo_info ();
2674 bitmap_obstack_initialize (&iteration_obstack
);
2676 compute_topo_order (graph
, ti
);
2678 while (ti
->topo_order
.length () != 0)
2681 i
= ti
->topo_order
.pop ();
2683 /* If this variable is not a representative, skip it. */
2687 /* In certain indirect cycle cases, we may merge this
2688 variable to another. */
2689 if (eliminate_indirect_cycles (i
) && find (i
) != i
)
2692 /* If the node has changed, we need to process the
2693 complex constraints and outgoing edges again. */
2694 if (bitmap_clear_bit (changed
, i
))
2699 vec
<constraint_t
> complex = graph
->complex[i
];
2700 varinfo_t vi
= get_varinfo (i
);
2701 bool solution_empty
;
2703 /* Compute the changed set of solution bits. If anything
2704 is in the solution just propagate that. */
2705 if (bitmap_bit_p (vi
->solution
, anything_id
))
2707 /* If anything is also in the old solution there is
2709 ??? But we shouldn't ended up with "changed" set ... */
2711 && bitmap_bit_p (vi
->oldsolution
, anything_id
))
2713 bitmap_copy (pts
, get_varinfo (find (anything_id
))->solution
);
2715 else if (vi
->oldsolution
)
2716 bitmap_and_compl (pts
, vi
->solution
, vi
->oldsolution
);
2718 bitmap_copy (pts
, vi
->solution
);
2720 if (bitmap_empty_p (pts
))
2723 if (vi
->oldsolution
)
2724 bitmap_ior_into (vi
->oldsolution
, pts
);
2727 vi
->oldsolution
= BITMAP_ALLOC (&oldpta_obstack
);
2728 bitmap_copy (vi
->oldsolution
, pts
);
2731 solution
= vi
->solution
;
2732 solution_empty
= bitmap_empty_p (solution
);
2734 /* Process the complex constraints */
2735 bitmap expanded_pts
= NULL
;
2736 FOR_EACH_VEC_ELT (complex, j
, c
)
2738 /* XXX: This is going to unsort the constraints in
2739 some cases, which will occasionally add duplicate
2740 constraints during unification. This does not
2741 affect correctness. */
2742 c
->lhs
.var
= find (c
->lhs
.var
);
2743 c
->rhs
.var
= find (c
->rhs
.var
);
2745 /* The only complex constraint that can change our
2746 solution to non-empty, given an empty solution,
2747 is a constraint where the lhs side is receiving
2748 some set from elsewhere. */
2749 if (!solution_empty
|| c
->lhs
.type
!= DEREF
)
2750 do_complex_constraint (graph
, c
, pts
, &expanded_pts
);
2752 BITMAP_FREE (expanded_pts
);
2754 solution_empty
= bitmap_empty_p (solution
);
2756 if (!solution_empty
)
2759 unsigned eff_escaped_id
= find (escaped_id
);
2761 /* Propagate solution to all successors. */
2762 EXECUTE_IF_IN_NONNULL_BITMAP (graph
->succs
[i
],
2768 unsigned int to
= find (j
);
2769 tmp
= get_varinfo (to
)->solution
;
2772 /* Don't try to propagate to ourselves. */
2776 /* If we propagate from ESCAPED use ESCAPED as
2778 if (i
== eff_escaped_id
)
2779 flag
= bitmap_set_bit (tmp
, escaped_id
);
2781 flag
= bitmap_ior_into (tmp
, pts
);
2784 bitmap_set_bit (changed
, to
);
2789 free_topo_info (ti
);
2790 bitmap_obstack_release (&iteration_obstack
);
2794 BITMAP_FREE (changed
);
2795 bitmap_obstack_release (&oldpta_obstack
);
2798 /* Map from trees to variable infos. */
2799 static hash_map
<tree
, varinfo_t
> *vi_for_tree
;
2802 /* Insert ID as the variable id for tree T in the vi_for_tree map. */
2805 insert_vi_for_tree (tree t
, varinfo_t vi
)
2808 gcc_assert (!vi_for_tree
->put (t
, vi
));
2811 /* Find the variable info for tree T in VI_FOR_TREE. If T does not
2812 exist in the map, return NULL, otherwise, return the varinfo we found. */
2815 lookup_vi_for_tree (tree t
)
2817 varinfo_t
*slot
= vi_for_tree
->get (t
);
2824 /* Return a printable name for DECL */
2827 alias_get_name (tree decl
)
2829 const char *res
= NULL
;
2831 int num_printed
= 0;
2836 if (TREE_CODE (decl
) == SSA_NAME
)
2838 res
= get_name (decl
);
2840 num_printed
= asprintf (&temp
, "%s_%u", res
, SSA_NAME_VERSION (decl
));
2842 num_printed
= asprintf (&temp
, "_%u", SSA_NAME_VERSION (decl
));
2843 if (num_printed
> 0)
2845 res
= ggc_strdup (temp
);
2849 else if (DECL_P (decl
))
2851 if (DECL_ASSEMBLER_NAME_SET_P (decl
))
2852 res
= IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl
));
2855 res
= get_name (decl
);
2858 num_printed
= asprintf (&temp
, "D.%u", DECL_UID (decl
));
2859 if (num_printed
> 0)
2861 res
= ggc_strdup (temp
);
2873 /* Find the variable id for tree T in the map.
2874 If T doesn't exist in the map, create an entry for it and return it. */
2877 get_vi_for_tree (tree t
)
2879 varinfo_t
*slot
= vi_for_tree
->get (t
);
2882 unsigned int id
= create_variable_info_for (t
, alias_get_name (t
), false);
2883 return get_varinfo (id
);
2889 /* Get a scalar constraint expression for a new temporary variable. */
2891 static struct constraint_expr
2892 new_scalar_tmp_constraint_exp (const char *name
, bool add_id
)
2894 struct constraint_expr tmp
;
2897 vi
= new_var_info (NULL_TREE
, name
, add_id
);
2901 vi
->is_full_var
= 1;
2910 /* Get a constraint expression vector from an SSA_VAR_P node.
2911 If address_p is true, the result will be taken its address of. */
2914 get_constraint_for_ssa_var (tree t
, vec
<ce_s
> *results
, bool address_p
)
2916 struct constraint_expr cexpr
;
2919 /* We allow FUNCTION_DECLs here even though it doesn't make much sense. */
2920 gcc_assert (TREE_CODE (t
) == SSA_NAME
|| DECL_P (t
));
2922 /* For parameters, get at the points-to set for the actual parm
2924 if (TREE_CODE (t
) == SSA_NAME
2925 && SSA_NAME_IS_DEFAULT_DEF (t
)
2926 && (TREE_CODE (SSA_NAME_VAR (t
)) == PARM_DECL
2927 || TREE_CODE (SSA_NAME_VAR (t
)) == RESULT_DECL
))
2929 get_constraint_for_ssa_var (SSA_NAME_VAR (t
), results
, address_p
);
2933 /* For global variables resort to the alias target. */
2934 if (TREE_CODE (t
) == VAR_DECL
2935 && (TREE_STATIC (t
) || DECL_EXTERNAL (t
)))
2937 varpool_node
*node
= varpool_node::get (t
);
2938 if (node
&& node
->alias
&& node
->analyzed
)
2940 node
= node
->ultimate_alias_target ();
2945 vi
= get_vi_for_tree (t
);
2947 cexpr
.type
= SCALAR
;
2950 /* If we are not taking the address of the constraint expr, add all
2951 sub-fiels of the variable as well. */
2953 && !vi
->is_full_var
)
2955 for (; vi
; vi
= vi_next (vi
))
2958 results
->safe_push (cexpr
);
2963 results
->safe_push (cexpr
);
2966 /* Process constraint T, performing various simplifications and then
2967 adding it to our list of overall constraints. */
2970 process_constraint (constraint_t t
)
2972 struct constraint_expr rhs
= t
->rhs
;
2973 struct constraint_expr lhs
= t
->lhs
;
2975 gcc_assert (rhs
.var
< varmap
.length ());
2976 gcc_assert (lhs
.var
< varmap
.length ());
2978 /* If we didn't get any useful constraint from the lhs we get
2979 &ANYTHING as fallback from get_constraint_for. Deal with
2980 it here by turning it into *ANYTHING. */
2981 if (lhs
.type
== ADDRESSOF
2982 && lhs
.var
== anything_id
)
2985 /* ADDRESSOF on the lhs is invalid. */
2986 gcc_assert (lhs
.type
!= ADDRESSOF
);
2988 /* We shouldn't add constraints from things that cannot have pointers.
2989 It's not completely trivial to avoid in the callers, so do it here. */
2990 if (rhs
.type
!= ADDRESSOF
2991 && !get_varinfo (rhs
.var
)->may_have_pointers
)
2994 /* Likewise adding to the solution of a non-pointer var isn't useful. */
2995 if (!get_varinfo (lhs
.var
)->may_have_pointers
)
2998 /* This can happen in our IR with things like n->a = *p */
2999 if (rhs
.type
== DEREF
&& lhs
.type
== DEREF
&& rhs
.var
!= anything_id
)
3001 /* Split into tmp = *rhs, *lhs = tmp */
3002 struct constraint_expr tmplhs
;
3003 tmplhs
= new_scalar_tmp_constraint_exp ("doubledereftmp", true);
3004 process_constraint (new_constraint (tmplhs
, rhs
));
3005 process_constraint (new_constraint (lhs
, tmplhs
));
3007 else if (rhs
.type
== ADDRESSOF
&& lhs
.type
== DEREF
)
3009 /* Split into tmp = &rhs, *lhs = tmp */
3010 struct constraint_expr tmplhs
;
3011 tmplhs
= new_scalar_tmp_constraint_exp ("derefaddrtmp", true);
3012 process_constraint (new_constraint (tmplhs
, rhs
));
3013 process_constraint (new_constraint (lhs
, tmplhs
));
3017 gcc_assert (rhs
.type
!= ADDRESSOF
|| rhs
.offset
== 0);
3018 constraints
.safe_push (t
);
3023 /* Return the position, in bits, of FIELD_DECL from the beginning of its
3026 static HOST_WIDE_INT
3027 bitpos_of_field (const tree fdecl
)
3029 if (!tree_fits_shwi_p (DECL_FIELD_OFFSET (fdecl
))
3030 || !tree_fits_shwi_p (DECL_FIELD_BIT_OFFSET (fdecl
)))
3033 return (tree_to_shwi (DECL_FIELD_OFFSET (fdecl
)) * BITS_PER_UNIT
3034 + tree_to_shwi (DECL_FIELD_BIT_OFFSET (fdecl
)));
3038 /* Get constraint expressions for offsetting PTR by OFFSET. Stores the
3039 resulting constraint expressions in *RESULTS. */
3042 get_constraint_for_ptr_offset (tree ptr
, tree offset
,
3045 struct constraint_expr c
;
3047 HOST_WIDE_INT rhsoffset
;
3049 /* If we do not do field-sensitive PTA adding offsets to pointers
3050 does not change the points-to solution. */
3051 if (!use_field_sensitive
)
3053 get_constraint_for_rhs (ptr
, results
);
3057 /* If the offset is not a non-negative integer constant that fits
3058 in a HOST_WIDE_INT, we have to fall back to a conservative
3059 solution which includes all sub-fields of all pointed-to
3060 variables of ptr. */
3061 if (offset
== NULL_TREE
3062 || TREE_CODE (offset
) != INTEGER_CST
)
3063 rhsoffset
= UNKNOWN_OFFSET
;
3066 /* Sign-extend the offset. */
3067 offset_int soffset
= offset_int::from (offset
, SIGNED
);
3068 if (!wi::fits_shwi_p (soffset
))
3069 rhsoffset
= UNKNOWN_OFFSET
;
3072 /* Make sure the bit-offset also fits. */
3073 HOST_WIDE_INT rhsunitoffset
= soffset
.to_shwi ();
3074 rhsoffset
= rhsunitoffset
* BITS_PER_UNIT
;
3075 if (rhsunitoffset
!= rhsoffset
/ BITS_PER_UNIT
)
3076 rhsoffset
= UNKNOWN_OFFSET
;
3080 get_constraint_for_rhs (ptr
, results
);
3084 /* As we are eventually appending to the solution do not use
3085 vec::iterate here. */
3086 n
= results
->length ();
3087 for (j
= 0; j
< n
; j
++)
3091 curr
= get_varinfo (c
.var
);
3093 if (c
.type
== ADDRESSOF
3094 /* If this varinfo represents a full variable just use it. */
3095 && curr
->is_full_var
)
3097 else if (c
.type
== ADDRESSOF
3098 /* If we do not know the offset add all subfields. */
3099 && rhsoffset
== UNKNOWN_OFFSET
)
3101 varinfo_t temp
= get_varinfo (curr
->head
);
3104 struct constraint_expr c2
;
3106 c2
.type
= ADDRESSOF
;
3108 if (c2
.var
!= c
.var
)
3109 results
->safe_push (c2
);
3110 temp
= vi_next (temp
);
3114 else if (c
.type
== ADDRESSOF
)
3117 unsigned HOST_WIDE_INT offset
= curr
->offset
+ rhsoffset
;
3119 /* If curr->offset + rhsoffset is less than zero adjust it. */
3121 && curr
->offset
< offset
)
3124 /* We have to include all fields that overlap the current
3125 field shifted by rhsoffset. And we include at least
3126 the last or the first field of the variable to represent
3127 reachability of off-bound addresses, in particular &object + 1,
3128 conservatively correct. */
3129 temp
= first_or_preceding_vi_for_offset (curr
, offset
);
3132 temp
= vi_next (temp
);
3134 && temp
->offset
< offset
+ curr
->size
)
3136 struct constraint_expr c2
;
3138 c2
.type
= ADDRESSOF
;
3140 results
->safe_push (c2
);
3141 temp
= vi_next (temp
);
3144 else if (c
.type
== SCALAR
)
3146 gcc_assert (c
.offset
== 0);
3147 c
.offset
= rhsoffset
;
3150 /* We shouldn't get any DEREFs here. */
3158 /* Given a COMPONENT_REF T, return the constraint_expr vector for it.
3159 If address_p is true the result will be taken its address of.
3160 If lhs_p is true then the constraint expression is assumed to be used
3164 get_constraint_for_component_ref (tree t
, vec
<ce_s
> *results
,
3165 bool address_p
, bool lhs_p
)
3168 HOST_WIDE_INT bitsize
= -1;
3169 HOST_WIDE_INT bitmaxsize
= -1;
3170 HOST_WIDE_INT bitpos
;
3173 /* Some people like to do cute things like take the address of
3176 while (handled_component_p (forzero
)
3177 || INDIRECT_REF_P (forzero
)
3178 || TREE_CODE (forzero
) == MEM_REF
)
3179 forzero
= TREE_OPERAND (forzero
, 0);
3181 if (CONSTANT_CLASS_P (forzero
) && integer_zerop (forzero
))
3183 struct constraint_expr temp
;
3186 temp
.var
= integer_id
;
3188 results
->safe_push (temp
);
3192 t
= get_ref_base_and_extent (t
, &bitpos
, &bitsize
, &bitmaxsize
);
3194 /* Pretend to take the address of the base, we'll take care of
3195 adding the required subset of sub-fields below. */
3196 get_constraint_for_1 (t
, results
, true, lhs_p
);
3197 gcc_assert (results
->length () == 1);
3198 struct constraint_expr
&result
= results
->last ();
3200 if (result
.type
== SCALAR
3201 && get_varinfo (result
.var
)->is_full_var
)
3202 /* For single-field vars do not bother about the offset. */
3204 else if (result
.type
== SCALAR
)
3206 /* In languages like C, you can access one past the end of an
3207 array. You aren't allowed to dereference it, so we can
3208 ignore this constraint. When we handle pointer subtraction,
3209 we may have to do something cute here. */
3211 if ((unsigned HOST_WIDE_INT
)bitpos
< get_varinfo (result
.var
)->fullsize
3214 /* It's also not true that the constraint will actually start at the
3215 right offset, it may start in some padding. We only care about
3216 setting the constraint to the first actual field it touches, so
3218 struct constraint_expr cexpr
= result
;
3222 for (curr
= get_varinfo (cexpr
.var
); curr
; curr
= vi_next (curr
))
3224 if (ranges_overlap_p (curr
->offset
, curr
->size
,
3225 bitpos
, bitmaxsize
))
3227 cexpr
.var
= curr
->id
;
3228 results
->safe_push (cexpr
);
3233 /* If we are going to take the address of this field then
3234 to be able to compute reachability correctly add at least
3235 the last field of the variable. */
3236 if (address_p
&& results
->length () == 0)
3238 curr
= get_varinfo (cexpr
.var
);
3239 while (curr
->next
!= 0)
3240 curr
= vi_next (curr
);
3241 cexpr
.var
= curr
->id
;
3242 results
->safe_push (cexpr
);
3244 else if (results
->length () == 0)
3245 /* Assert that we found *some* field there. The user couldn't be
3246 accessing *only* padding. */
3247 /* Still the user could access one past the end of an array
3248 embedded in a struct resulting in accessing *only* padding. */
3249 /* Or accessing only padding via type-punning to a type
3250 that has a filed just in padding space. */
3252 cexpr
.type
= SCALAR
;
3253 cexpr
.var
= anything_id
;
3255 results
->safe_push (cexpr
);
3258 else if (bitmaxsize
== 0)
3260 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3261 fprintf (dump_file
, "Access to zero-sized part of variable,"
3265 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3266 fprintf (dump_file
, "Access to past the end of variable, ignoring\n");
3268 else if (result
.type
== DEREF
)
3270 /* If we do not know exactly where the access goes say so. Note
3271 that only for non-structure accesses we know that we access
3272 at most one subfiled of any variable. */
3274 || bitsize
!= bitmaxsize
3275 || AGGREGATE_TYPE_P (TREE_TYPE (orig_t
))
3276 || result
.offset
== UNKNOWN_OFFSET
)
3277 result
.offset
= UNKNOWN_OFFSET
;
3279 result
.offset
+= bitpos
;
3281 else if (result
.type
== ADDRESSOF
)
3283 /* We can end up here for component references on a
3284 VIEW_CONVERT_EXPR <>(&foobar). */
3285 result
.type
= SCALAR
;
3286 result
.var
= anything_id
;
3294 /* Dereference the constraint expression CONS, and return the result.
3295 DEREF (ADDRESSOF) = SCALAR
3296 DEREF (SCALAR) = DEREF
3297 DEREF (DEREF) = (temp = DEREF1; result = DEREF(temp))
3298 This is needed so that we can handle dereferencing DEREF constraints. */
3301 do_deref (vec
<ce_s
> *constraints
)
3303 struct constraint_expr
*c
;
3306 FOR_EACH_VEC_ELT (*constraints
, i
, c
)
3308 if (c
->type
== SCALAR
)
3310 else if (c
->type
== ADDRESSOF
)
3312 else if (c
->type
== DEREF
)
3314 struct constraint_expr tmplhs
;
3315 tmplhs
= new_scalar_tmp_constraint_exp ("dereftmp", true);
3316 process_constraint (new_constraint (tmplhs
, *c
));
3317 c
->var
= tmplhs
.var
;
3324 /* Given a tree T, return the constraint expression for taking the
3328 get_constraint_for_address_of (tree t
, vec
<ce_s
> *results
)
3330 struct constraint_expr
*c
;
3333 get_constraint_for_1 (t
, results
, true, true);
3335 FOR_EACH_VEC_ELT (*results
, i
, c
)
3337 if (c
->type
== DEREF
)
3340 c
->type
= ADDRESSOF
;
3344 /* Given a tree T, return the constraint expression for it. */
3347 get_constraint_for_1 (tree t
, vec
<ce_s
> *results
, bool address_p
,
3350 struct constraint_expr temp
;
3352 /* x = integer is all glommed to a single variable, which doesn't
3353 point to anything by itself. That is, of course, unless it is an
3354 integer constant being treated as a pointer, in which case, we
3355 will return that this is really the addressof anything. This
3356 happens below, since it will fall into the default case. The only
3357 case we know something about an integer treated like a pointer is
3358 when it is the NULL pointer, and then we just say it points to
3361 Do not do that if -fno-delete-null-pointer-checks though, because
3362 in that case *NULL does not fail, so it _should_ alias *anything.
3363 It is not worth adding a new option or renaming the existing one,
3364 since this case is relatively obscure. */
3365 if ((TREE_CODE (t
) == INTEGER_CST
3366 && integer_zerop (t
))
3367 /* The only valid CONSTRUCTORs in gimple with pointer typed
3368 elements are zero-initializer. But in IPA mode we also
3369 process global initializers, so verify at least. */
3370 || (TREE_CODE (t
) == CONSTRUCTOR
3371 && CONSTRUCTOR_NELTS (t
) == 0))
3373 if (flag_delete_null_pointer_checks
)
3374 temp
.var
= nothing_id
;
3376 temp
.var
= nonlocal_id
;
3377 temp
.type
= ADDRESSOF
;
3379 results
->safe_push (temp
);
3383 /* String constants are read-only, ideally we'd have a CONST_DECL
3385 if (TREE_CODE (t
) == STRING_CST
)
3387 temp
.var
= string_id
;
3390 results
->safe_push (temp
);
3394 switch (TREE_CODE_CLASS (TREE_CODE (t
)))
3396 case tcc_expression
:
3398 switch (TREE_CODE (t
))
3401 get_constraint_for_address_of (TREE_OPERAND (t
, 0), results
);
3409 switch (TREE_CODE (t
))
3413 struct constraint_expr cs
;
3415 get_constraint_for_ptr_offset (TREE_OPERAND (t
, 0),
3416 TREE_OPERAND (t
, 1), results
);
3419 /* If we are not taking the address then make sure to process
3420 all subvariables we might access. */
3424 cs
= results
->last ();
3425 if (cs
.type
== DEREF
3426 && type_can_have_subvars (TREE_TYPE (t
)))
3428 /* For dereferences this means we have to defer it
3430 results
->last ().offset
= UNKNOWN_OFFSET
;
3433 if (cs
.type
!= SCALAR
)
3436 vi
= get_varinfo (cs
.var
);
3437 curr
= vi_next (vi
);
3438 if (!vi
->is_full_var
3441 unsigned HOST_WIDE_INT size
;
3442 if (tree_fits_uhwi_p (TYPE_SIZE (TREE_TYPE (t
))))
3443 size
= tree_to_uhwi (TYPE_SIZE (TREE_TYPE (t
)));
3446 for (; curr
; curr
= vi_next (curr
))
3448 if (curr
->offset
- vi
->offset
< size
)
3451 results
->safe_push (cs
);
3460 case ARRAY_RANGE_REF
:
3465 get_constraint_for_component_ref (t
, results
, address_p
, lhs_p
);
3467 case VIEW_CONVERT_EXPR
:
3468 get_constraint_for_1 (TREE_OPERAND (t
, 0), results
, address_p
,
3471 /* We are missing handling for TARGET_MEM_REF here. */
3476 case tcc_exceptional
:
3478 switch (TREE_CODE (t
))
3482 get_constraint_for_ssa_var (t
, results
, address_p
);
3490 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t
), i
, val
)
3492 struct constraint_expr
*rhsp
;
3494 get_constraint_for_1 (val
, &tmp
, address_p
, lhs_p
);
3495 FOR_EACH_VEC_ELT (tmp
, j
, rhsp
)
3496 results
->safe_push (*rhsp
);
3499 /* We do not know whether the constructor was complete,
3500 so technically we have to add &NOTHING or &ANYTHING
3501 like we do for an empty constructor as well. */
3508 case tcc_declaration
:
3510 get_constraint_for_ssa_var (t
, results
, address_p
);
3515 /* We cannot refer to automatic variables through constants. */
3516 temp
.type
= ADDRESSOF
;
3517 temp
.var
= nonlocal_id
;
3519 results
->safe_push (temp
);
3525 /* The default fallback is a constraint from anything. */
3526 temp
.type
= ADDRESSOF
;
3527 temp
.var
= anything_id
;
3529 results
->safe_push (temp
);
3532 /* Given a gimple tree T, return the constraint expression vector for it. */
3535 get_constraint_for (tree t
, vec
<ce_s
> *results
)
3537 gcc_assert (results
->length () == 0);
3539 get_constraint_for_1 (t
, results
, false, true);
3542 /* Given a gimple tree T, return the constraint expression vector for it
3543 to be used as the rhs of a constraint. */
3546 get_constraint_for_rhs (tree t
, vec
<ce_s
> *results
)
3548 gcc_assert (results
->length () == 0);
3550 get_constraint_for_1 (t
, results
, false, false);
3554 /* Efficiently generates constraints from all entries in *RHSC to all
3555 entries in *LHSC. */
3558 process_all_all_constraints (vec
<ce_s
> lhsc
,
3561 struct constraint_expr
*lhsp
, *rhsp
;
3564 if (lhsc
.length () <= 1 || rhsc
.length () <= 1)
3566 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
3567 FOR_EACH_VEC_ELT (rhsc
, j
, rhsp
)
3568 process_constraint (new_constraint (*lhsp
, *rhsp
));
3572 struct constraint_expr tmp
;
3573 tmp
= new_scalar_tmp_constraint_exp ("allalltmp", true);
3574 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
3575 process_constraint (new_constraint (tmp
, *rhsp
));
3576 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
3577 process_constraint (new_constraint (*lhsp
, tmp
));
3581 /* Handle aggregate copies by expanding into copies of the respective
3582 fields of the structures. */
3585 do_structure_copy (tree lhsop
, tree rhsop
)
3587 struct constraint_expr
*lhsp
, *rhsp
;
3588 auto_vec
<ce_s
> lhsc
;
3589 auto_vec
<ce_s
> rhsc
;
3592 get_constraint_for (lhsop
, &lhsc
);
3593 get_constraint_for_rhs (rhsop
, &rhsc
);
3596 if (lhsp
->type
== DEREF
3597 || (lhsp
->type
== ADDRESSOF
&& lhsp
->var
== anything_id
)
3598 || rhsp
->type
== DEREF
)
3600 if (lhsp
->type
== DEREF
)
3602 gcc_assert (lhsc
.length () == 1);
3603 lhsp
->offset
= UNKNOWN_OFFSET
;
3605 if (rhsp
->type
== DEREF
)
3607 gcc_assert (rhsc
.length () == 1);
3608 rhsp
->offset
= UNKNOWN_OFFSET
;
3610 process_all_all_constraints (lhsc
, rhsc
);
3612 else if (lhsp
->type
== SCALAR
3613 && (rhsp
->type
== SCALAR
3614 || rhsp
->type
== ADDRESSOF
))
3616 HOST_WIDE_INT lhssize
, lhsmaxsize
, lhsoffset
;
3617 HOST_WIDE_INT rhssize
, rhsmaxsize
, rhsoffset
;
3619 get_ref_base_and_extent (lhsop
, &lhsoffset
, &lhssize
, &lhsmaxsize
);
3620 get_ref_base_and_extent (rhsop
, &rhsoffset
, &rhssize
, &rhsmaxsize
);
3621 for (j
= 0; lhsc
.iterate (j
, &lhsp
);)
3623 varinfo_t lhsv
, rhsv
;
3625 lhsv
= get_varinfo (lhsp
->var
);
3626 rhsv
= get_varinfo (rhsp
->var
);
3627 if (lhsv
->may_have_pointers
3628 && (lhsv
->is_full_var
3629 || rhsv
->is_full_var
3630 || ranges_overlap_p (lhsv
->offset
+ rhsoffset
, lhsv
->size
,
3631 rhsv
->offset
+ lhsoffset
, rhsv
->size
)))
3632 process_constraint (new_constraint (*lhsp
, *rhsp
));
3633 if (!rhsv
->is_full_var
3634 && (lhsv
->is_full_var
3635 || (lhsv
->offset
+ rhsoffset
+ lhsv
->size
3636 > rhsv
->offset
+ lhsoffset
+ rhsv
->size
)))
3639 if (k
>= rhsc
.length ())
3650 /* Create constraints ID = { rhsc }. */
3653 make_constraints_to (unsigned id
, vec
<ce_s
> rhsc
)
3655 struct constraint_expr
*c
;
3656 struct constraint_expr includes
;
3660 includes
.offset
= 0;
3661 includes
.type
= SCALAR
;
3663 FOR_EACH_VEC_ELT (rhsc
, j
, c
)
3664 process_constraint (new_constraint (includes
, *c
));
3667 /* Create a constraint ID = OP. */
3670 make_constraint_to (unsigned id
, tree op
)
3672 auto_vec
<ce_s
> rhsc
;
3673 get_constraint_for_rhs (op
, &rhsc
);
3674 make_constraints_to (id
, rhsc
);
3677 /* Create a constraint ID = &FROM. */
3680 make_constraint_from (varinfo_t vi
, int from
)
3682 struct constraint_expr lhs
, rhs
;
3690 rhs
.type
= ADDRESSOF
;
3691 process_constraint (new_constraint (lhs
, rhs
));
3694 /* Create a constraint ID = FROM. */
3697 make_copy_constraint (varinfo_t vi
, int from
)
3699 struct constraint_expr lhs
, rhs
;
3708 process_constraint (new_constraint (lhs
, rhs
));
3711 /* Make constraints necessary to make OP escape. */
3714 make_escape_constraint (tree op
)
3716 make_constraint_to (escaped_id
, op
);
3719 /* Add constraints to that the solution of VI is transitively closed. */
3722 make_transitive_closure_constraints (varinfo_t vi
)
3724 struct constraint_expr lhs
, rhs
;
3732 rhs
.offset
= UNKNOWN_OFFSET
;
3733 process_constraint (new_constraint (lhs
, rhs
));
3736 /* Temporary storage for fake var decls. */
3737 struct obstack fake_var_decl_obstack
;
3739 /* Build a fake VAR_DECL acting as referrer to a DECL_UID. */
3742 build_fake_var_decl (tree type
)
3744 tree decl
= (tree
) XOBNEW (&fake_var_decl_obstack
, struct tree_var_decl
);
3745 memset (decl
, 0, sizeof (struct tree_var_decl
));
3746 TREE_SET_CODE (decl
, VAR_DECL
);
3747 TREE_TYPE (decl
) = type
;
3748 DECL_UID (decl
) = allocate_decl_uid ();
3749 SET_DECL_PT_UID (decl
, -1);
3750 layout_decl (decl
, 0);
3754 /* Create a new artificial heap variable with NAME.
3755 Return the created variable. */
3758 make_heapvar (const char *name
, bool add_id
)
3763 heapvar
= build_fake_var_decl (ptr_type_node
);
3764 DECL_EXTERNAL (heapvar
) = 1;
3766 vi
= new_var_info (heapvar
, name
, add_id
);
3767 vi
->is_artificial_var
= true;
3768 vi
->is_heap_var
= true;
3769 vi
->is_unknown_size_var
= true;
3773 vi
->is_full_var
= true;
3774 insert_vi_for_tree (heapvar
, vi
);
3779 /* Create a new artificial heap variable with NAME and make a
3780 constraint from it to LHS. Set flags according to a tag used
3781 for tracking restrict pointers. */
3784 make_constraint_from_restrict (varinfo_t lhs
, const char *name
, bool add_id
)
3786 varinfo_t vi
= make_heapvar (name
, add_id
);
3787 vi
->is_restrict_var
= 1;
3788 vi
->is_global_var
= 1;
3789 vi
->may_have_pointers
= 1;
3790 make_constraint_from (lhs
, vi
->id
);
3794 /* Create a new artificial heap variable with NAME and make a
3795 constraint from it to LHS. Set flags according to a tag used
3796 for tracking restrict pointers and make the artificial heap
3797 point to global memory. */
3800 make_constraint_from_global_restrict (varinfo_t lhs
, const char *name
,
3803 varinfo_t vi
= make_constraint_from_restrict (lhs
, name
, add_id
);
3804 make_copy_constraint (vi
, nonlocal_id
);
3808 /* In IPA mode there are varinfos for different aspects of reach
3809 function designator. One for the points-to set of the return
3810 value, one for the variables that are clobbered by the function,
3811 one for its uses and one for each parameter (including a single
3812 glob for remaining variadic arguments). */
3814 enum { fi_clobbers
= 1, fi_uses
= 2,
3815 fi_static_chain
= 3, fi_result
= 4, fi_parm_base
= 5 };
3817 /* Get a constraint for the requested part of a function designator FI
3818 when operating in IPA mode. */
3820 static struct constraint_expr
3821 get_function_part_constraint (varinfo_t fi
, unsigned part
)
3823 struct constraint_expr c
;
3825 gcc_assert (in_ipa_mode
);
3827 if (fi
->id
== anything_id
)
3829 /* ??? We probably should have a ANYFN special variable. */
3830 c
.var
= anything_id
;
3834 else if (TREE_CODE (fi
->decl
) == FUNCTION_DECL
)
3836 varinfo_t ai
= first_vi_for_offset (fi
, part
);
3840 c
.var
= anything_id
;
3854 /* For non-IPA mode, generate constraints necessary for a call on the
3858 handle_rhs_call (gcall
*stmt
, vec
<ce_s
> *results
)
3860 struct constraint_expr rhsc
;
3862 bool returns_uses
= false;
3864 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
3866 tree arg
= gimple_call_arg (stmt
, i
);
3867 int flags
= gimple_call_arg_flags (stmt
, i
);
3869 /* If the argument is not used we can ignore it. */
3870 if (flags
& EAF_UNUSED
)
3873 /* As we compute ESCAPED context-insensitive we do not gain
3874 any precision with just EAF_NOCLOBBER but not EAF_NOESCAPE
3875 set. The argument would still get clobbered through the
3877 if ((flags
& EAF_NOCLOBBER
)
3878 && (flags
& EAF_NOESCAPE
))
3880 varinfo_t uses
= get_call_use_vi (stmt
);
3881 if (!(flags
& EAF_DIRECT
))
3883 varinfo_t tem
= new_var_info (NULL_TREE
, "callarg", true);
3884 make_constraint_to (tem
->id
, arg
);
3885 make_transitive_closure_constraints (tem
);
3886 make_copy_constraint (uses
, tem
->id
);
3889 make_constraint_to (uses
->id
, arg
);
3890 returns_uses
= true;
3892 else if (flags
& EAF_NOESCAPE
)
3894 struct constraint_expr lhs
, rhs
;
3895 varinfo_t uses
= get_call_use_vi (stmt
);
3896 varinfo_t clobbers
= get_call_clobber_vi (stmt
);
3897 varinfo_t tem
= new_var_info (NULL_TREE
, "callarg", true);
3898 make_constraint_to (tem
->id
, arg
);
3899 if (!(flags
& EAF_DIRECT
))
3900 make_transitive_closure_constraints (tem
);
3901 make_copy_constraint (uses
, tem
->id
);
3902 make_copy_constraint (clobbers
, tem
->id
);
3903 /* Add *tem = nonlocal, do not add *tem = callused as
3904 EAF_NOESCAPE parameters do not escape to other parameters
3905 and all other uses appear in NONLOCAL as well. */
3910 rhs
.var
= nonlocal_id
;
3912 process_constraint (new_constraint (lhs
, rhs
));
3913 returns_uses
= true;
3916 make_escape_constraint (arg
);
3919 /* If we added to the calls uses solution make sure we account for
3920 pointers to it to be returned. */
3923 rhsc
.var
= get_call_use_vi (stmt
)->id
;
3926 results
->safe_push (rhsc
);
3929 /* The static chain escapes as well. */
3930 if (gimple_call_chain (stmt
))
3931 make_escape_constraint (gimple_call_chain (stmt
));
3933 /* And if we applied NRV the address of the return slot escapes as well. */
3934 if (gimple_call_return_slot_opt_p (stmt
)
3935 && gimple_call_lhs (stmt
) != NULL_TREE
3936 && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt
))))
3938 auto_vec
<ce_s
> tmpc
;
3939 struct constraint_expr lhsc
, *c
;
3940 get_constraint_for_address_of (gimple_call_lhs (stmt
), &tmpc
);
3941 lhsc
.var
= escaped_id
;
3944 FOR_EACH_VEC_ELT (tmpc
, i
, c
)
3945 process_constraint (new_constraint (lhsc
, *c
));
3948 /* Regular functions return nonlocal memory. */
3949 rhsc
.var
= nonlocal_id
;
3952 results
->safe_push (rhsc
);
3955 /* For non-IPA mode, generate constraints necessary for a call
3956 that returns a pointer and assigns it to LHS. This simply makes
3957 the LHS point to global and escaped variables. */
3960 handle_lhs_call (gcall
*stmt
, tree lhs
, int flags
, vec
<ce_s
> rhsc
,
3963 auto_vec
<ce_s
> lhsc
;
3965 get_constraint_for (lhs
, &lhsc
);
3966 /* If the store is to a global decl make sure to
3967 add proper escape constraints. */
3968 lhs
= get_base_address (lhs
);
3971 && is_global_var (lhs
))
3973 struct constraint_expr tmpc
;
3974 tmpc
.var
= escaped_id
;
3977 lhsc
.safe_push (tmpc
);
3980 /* If the call returns an argument unmodified override the rhs
3982 if (flags
& ERF_RETURNS_ARG
3983 && (flags
& ERF_RETURN_ARG_MASK
) < gimple_call_num_args (stmt
))
3987 arg
= gimple_call_arg (stmt
, flags
& ERF_RETURN_ARG_MASK
);
3988 get_constraint_for (arg
, &rhsc
);
3989 process_all_all_constraints (lhsc
, rhsc
);
3992 else if (flags
& ERF_NOALIAS
)
3995 struct constraint_expr tmpc
;
3997 vi
= make_heapvar ("HEAP", true);
3998 /* We are marking allocated storage local, we deal with it becoming
3999 global by escaping and setting of vars_contains_escaped_heap. */
4000 DECL_EXTERNAL (vi
->decl
) = 0;
4001 vi
->is_global_var
= 0;
4002 /* If this is not a real malloc call assume the memory was
4003 initialized and thus may point to global memory. All
4004 builtin functions with the malloc attribute behave in a sane way. */
4006 || DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_NORMAL
)
4007 make_constraint_from (vi
, nonlocal_id
);
4010 tmpc
.type
= ADDRESSOF
;
4011 rhsc
.safe_push (tmpc
);
4012 process_all_all_constraints (lhsc
, rhsc
);
4016 process_all_all_constraints (lhsc
, rhsc
);
4019 /* For non-IPA mode, generate constraints necessary for a call of a
4020 const function that returns a pointer in the statement STMT. */
4023 handle_const_call (gcall
*stmt
, vec
<ce_s
> *results
)
4025 struct constraint_expr rhsc
;
4028 /* Treat nested const functions the same as pure functions as far
4029 as the static chain is concerned. */
4030 if (gimple_call_chain (stmt
))
4032 varinfo_t uses
= get_call_use_vi (stmt
);
4033 make_transitive_closure_constraints (uses
);
4034 make_constraint_to (uses
->id
, gimple_call_chain (stmt
));
4035 rhsc
.var
= uses
->id
;
4038 results
->safe_push (rhsc
);
4041 /* May return arguments. */
4042 for (k
= 0; k
< gimple_call_num_args (stmt
); ++k
)
4044 tree arg
= gimple_call_arg (stmt
, k
);
4045 auto_vec
<ce_s
> argc
;
4047 struct constraint_expr
*argp
;
4048 get_constraint_for_rhs (arg
, &argc
);
4049 FOR_EACH_VEC_ELT (argc
, i
, argp
)
4050 results
->safe_push (*argp
);
4053 /* May return addresses of globals. */
4054 rhsc
.var
= nonlocal_id
;
4056 rhsc
.type
= ADDRESSOF
;
4057 results
->safe_push (rhsc
);
4060 /* For non-IPA mode, generate constraints necessary for a call to a
4061 pure function in statement STMT. */
4064 handle_pure_call (gcall
*stmt
, vec
<ce_s
> *results
)
4066 struct constraint_expr rhsc
;
4068 varinfo_t uses
= NULL
;
4070 /* Memory reached from pointer arguments is call-used. */
4071 for (i
= 0; i
< gimple_call_num_args (stmt
); ++i
)
4073 tree arg
= gimple_call_arg (stmt
, i
);
4076 uses
= get_call_use_vi (stmt
);
4077 make_transitive_closure_constraints (uses
);
4079 make_constraint_to (uses
->id
, arg
);
4082 /* The static chain is used as well. */
4083 if (gimple_call_chain (stmt
))
4087 uses
= get_call_use_vi (stmt
);
4088 make_transitive_closure_constraints (uses
);
4090 make_constraint_to (uses
->id
, gimple_call_chain (stmt
));
4093 /* Pure functions may return call-used and nonlocal memory. */
4096 rhsc
.var
= uses
->id
;
4099 results
->safe_push (rhsc
);
4101 rhsc
.var
= nonlocal_id
;
4104 results
->safe_push (rhsc
);
4108 /* Return the varinfo for the callee of CALL. */
4111 get_fi_for_callee (gcall
*call
)
4113 tree decl
, fn
= gimple_call_fn (call
);
4115 if (fn
&& TREE_CODE (fn
) == OBJ_TYPE_REF
)
4116 fn
= OBJ_TYPE_REF_EXPR (fn
);
4118 /* If we can directly resolve the function being called, do so.
4119 Otherwise, it must be some sort of indirect expression that
4120 we should still be able to handle. */
4121 decl
= gimple_call_addr_fndecl (fn
);
4123 return get_vi_for_tree (decl
);
4125 /* If the function is anything other than a SSA name pointer we have no
4126 clue and should be getting ANYFN (well, ANYTHING for now). */
4127 if (!fn
|| TREE_CODE (fn
) != SSA_NAME
)
4128 return get_varinfo (anything_id
);
4130 if (SSA_NAME_IS_DEFAULT_DEF (fn
)
4131 && (TREE_CODE (SSA_NAME_VAR (fn
)) == PARM_DECL
4132 || TREE_CODE (SSA_NAME_VAR (fn
)) == RESULT_DECL
))
4133 fn
= SSA_NAME_VAR (fn
);
4135 return get_vi_for_tree (fn
);
4138 /* Create constraints for the builtin call T. Return true if the call
4139 was handled, otherwise false. */
4142 find_func_aliases_for_builtin_call (struct function
*fn
, gcall
*t
)
4144 tree fndecl
= gimple_call_fndecl (t
);
4145 auto_vec
<ce_s
, 2> lhsc
;
4146 auto_vec
<ce_s
, 4> rhsc
;
4149 if (gimple_call_builtin_p (t
, BUILT_IN_NORMAL
))
4150 /* ??? All builtins that are handled here need to be handled
4151 in the alias-oracle query functions explicitly! */
4152 switch (DECL_FUNCTION_CODE (fndecl
))
4154 /* All the following functions return a pointer to the same object
4155 as their first argument points to. The functions do not add
4156 to the ESCAPED solution. The functions make the first argument
4157 pointed to memory point to what the second argument pointed to
4158 memory points to. */
4159 case BUILT_IN_STRCPY
:
4160 case BUILT_IN_STRNCPY
:
4161 case BUILT_IN_BCOPY
:
4162 case BUILT_IN_MEMCPY
:
4163 case BUILT_IN_MEMMOVE
:
4164 case BUILT_IN_MEMPCPY
:
4165 case BUILT_IN_STPCPY
:
4166 case BUILT_IN_STPNCPY
:
4167 case BUILT_IN_STRCAT
:
4168 case BUILT_IN_STRNCAT
:
4169 case BUILT_IN_STRCPY_CHK
:
4170 case BUILT_IN_STRNCPY_CHK
:
4171 case BUILT_IN_MEMCPY_CHK
:
4172 case BUILT_IN_MEMMOVE_CHK
:
4173 case BUILT_IN_MEMPCPY_CHK
:
4174 case BUILT_IN_STPCPY_CHK
:
4175 case BUILT_IN_STPNCPY_CHK
:
4176 case BUILT_IN_STRCAT_CHK
:
4177 case BUILT_IN_STRNCAT_CHK
:
4178 case BUILT_IN_TM_MEMCPY
:
4179 case BUILT_IN_TM_MEMMOVE
:
4181 tree res
= gimple_call_lhs (t
);
4182 tree dest
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (fndecl
)
4183 == BUILT_IN_BCOPY
? 1 : 0));
4184 tree src
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (fndecl
)
4185 == BUILT_IN_BCOPY
? 0 : 1));
4186 if (res
!= NULL_TREE
)
4188 get_constraint_for (res
, &lhsc
);
4189 if (DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_MEMPCPY
4190 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPCPY
4191 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPNCPY
4192 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_MEMPCPY_CHK
4193 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPCPY_CHK
4194 || DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STPNCPY_CHK
)
4195 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &rhsc
);
4197 get_constraint_for (dest
, &rhsc
);
4198 process_all_all_constraints (lhsc
, rhsc
);
4202 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4203 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4206 process_all_all_constraints (lhsc
, rhsc
);
4209 case BUILT_IN_MEMSET
:
4210 case BUILT_IN_MEMSET_CHK
:
4211 case BUILT_IN_TM_MEMSET
:
4213 tree res
= gimple_call_lhs (t
);
4214 tree dest
= gimple_call_arg (t
, 0);
4217 struct constraint_expr ac
;
4218 if (res
!= NULL_TREE
)
4220 get_constraint_for (res
, &lhsc
);
4221 get_constraint_for (dest
, &rhsc
);
4222 process_all_all_constraints (lhsc
, rhsc
);
4225 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4227 if (flag_delete_null_pointer_checks
4228 && integer_zerop (gimple_call_arg (t
, 1)))
4230 ac
.type
= ADDRESSOF
;
4231 ac
.var
= nothing_id
;
4236 ac
.var
= integer_id
;
4239 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
4240 process_constraint (new_constraint (*lhsp
, ac
));
4243 case BUILT_IN_POSIX_MEMALIGN
:
4245 tree ptrptr
= gimple_call_arg (t
, 0);
4246 get_constraint_for (ptrptr
, &lhsc
);
4248 varinfo_t vi
= make_heapvar ("HEAP", true);
4249 /* We are marking allocated storage local, we deal with it becoming
4250 global by escaping and setting of vars_contains_escaped_heap. */
4251 DECL_EXTERNAL (vi
->decl
) = 0;
4252 vi
->is_global_var
= 0;
4253 struct constraint_expr tmpc
;
4256 tmpc
.type
= ADDRESSOF
;
4257 rhsc
.safe_push (tmpc
);
4258 process_all_all_constraints (lhsc
, rhsc
);
4261 case BUILT_IN_ASSUME_ALIGNED
:
4263 tree res
= gimple_call_lhs (t
);
4264 tree dest
= gimple_call_arg (t
, 0);
4265 if (res
!= NULL_TREE
)
4267 get_constraint_for (res
, &lhsc
);
4268 get_constraint_for (dest
, &rhsc
);
4269 process_all_all_constraints (lhsc
, rhsc
);
4273 /* All the following functions do not return pointers, do not
4274 modify the points-to sets of memory reachable from their
4275 arguments and do not add to the ESCAPED solution. */
4276 case BUILT_IN_SINCOS
:
4277 case BUILT_IN_SINCOSF
:
4278 case BUILT_IN_SINCOSL
:
4279 case BUILT_IN_FREXP
:
4280 case BUILT_IN_FREXPF
:
4281 case BUILT_IN_FREXPL
:
4282 case BUILT_IN_GAMMA_R
:
4283 case BUILT_IN_GAMMAF_R
:
4284 case BUILT_IN_GAMMAL_R
:
4285 case BUILT_IN_LGAMMA_R
:
4286 case BUILT_IN_LGAMMAF_R
:
4287 case BUILT_IN_LGAMMAL_R
:
4289 case BUILT_IN_MODFF
:
4290 case BUILT_IN_MODFL
:
4291 case BUILT_IN_REMQUO
:
4292 case BUILT_IN_REMQUOF
:
4293 case BUILT_IN_REMQUOL
:
4296 case BUILT_IN_STRDUP
:
4297 case BUILT_IN_STRNDUP
:
4298 case BUILT_IN_REALLOC
:
4299 if (gimple_call_lhs (t
))
4301 handle_lhs_call (t
, gimple_call_lhs (t
),
4302 gimple_call_return_flags (t
) | ERF_NOALIAS
,
4304 get_constraint_for_ptr_offset (gimple_call_lhs (t
),
4306 get_constraint_for_ptr_offset (gimple_call_arg (t
, 0),
4310 process_all_all_constraints (lhsc
, rhsc
);
4313 /* For realloc the resulting pointer can be equal to the
4314 argument as well. But only doing this wouldn't be
4315 correct because with ptr == 0 realloc behaves like malloc. */
4316 if (DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_REALLOC
)
4318 get_constraint_for (gimple_call_lhs (t
), &lhsc
);
4319 get_constraint_for (gimple_call_arg (t
, 0), &rhsc
);
4320 process_all_all_constraints (lhsc
, rhsc
);
4325 /* String / character search functions return a pointer into the
4326 source string or NULL. */
4327 case BUILT_IN_INDEX
:
4328 case BUILT_IN_STRCHR
:
4329 case BUILT_IN_STRRCHR
:
4330 case BUILT_IN_MEMCHR
:
4331 case BUILT_IN_STRSTR
:
4332 case BUILT_IN_STRPBRK
:
4333 if (gimple_call_lhs (t
))
4335 tree src
= gimple_call_arg (t
, 0);
4336 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4337 constraint_expr nul
;
4338 nul
.var
= nothing_id
;
4340 nul
.type
= ADDRESSOF
;
4341 rhsc
.safe_push (nul
);
4342 get_constraint_for (gimple_call_lhs (t
), &lhsc
);
4343 process_all_all_constraints (lhsc
, rhsc
);
4346 /* Trampolines are special - they set up passing the static
4348 case BUILT_IN_INIT_TRAMPOLINE
:
4350 tree tramp
= gimple_call_arg (t
, 0);
4351 tree nfunc
= gimple_call_arg (t
, 1);
4352 tree frame
= gimple_call_arg (t
, 2);
4354 struct constraint_expr lhs
, *rhsp
;
4357 varinfo_t nfi
= NULL
;
4358 gcc_assert (TREE_CODE (nfunc
) == ADDR_EXPR
);
4359 nfi
= lookup_vi_for_tree (TREE_OPERAND (nfunc
, 0));
4362 lhs
= get_function_part_constraint (nfi
, fi_static_chain
);
4363 get_constraint_for (frame
, &rhsc
);
4364 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4365 process_constraint (new_constraint (lhs
, *rhsp
));
4368 /* Make the frame point to the function for
4369 the trampoline adjustment call. */
4370 get_constraint_for (tramp
, &lhsc
);
4372 get_constraint_for (nfunc
, &rhsc
);
4373 process_all_all_constraints (lhsc
, rhsc
);
4378 /* Else fallthru to generic handling which will let
4379 the frame escape. */
4382 case BUILT_IN_ADJUST_TRAMPOLINE
:
4384 tree tramp
= gimple_call_arg (t
, 0);
4385 tree res
= gimple_call_lhs (t
);
4386 if (in_ipa_mode
&& res
)
4388 get_constraint_for (res
, &lhsc
);
4389 get_constraint_for (tramp
, &rhsc
);
4391 process_all_all_constraints (lhsc
, rhsc
);
4395 CASE_BUILT_IN_TM_STORE (1):
4396 CASE_BUILT_IN_TM_STORE (2):
4397 CASE_BUILT_IN_TM_STORE (4):
4398 CASE_BUILT_IN_TM_STORE (8):
4399 CASE_BUILT_IN_TM_STORE (FLOAT
):
4400 CASE_BUILT_IN_TM_STORE (DOUBLE
):
4401 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
4402 CASE_BUILT_IN_TM_STORE (M64
):
4403 CASE_BUILT_IN_TM_STORE (M128
):
4404 CASE_BUILT_IN_TM_STORE (M256
):
4406 tree addr
= gimple_call_arg (t
, 0);
4407 tree src
= gimple_call_arg (t
, 1);
4409 get_constraint_for (addr
, &lhsc
);
4411 get_constraint_for (src
, &rhsc
);
4412 process_all_all_constraints (lhsc
, rhsc
);
4415 CASE_BUILT_IN_TM_LOAD (1):
4416 CASE_BUILT_IN_TM_LOAD (2):
4417 CASE_BUILT_IN_TM_LOAD (4):
4418 CASE_BUILT_IN_TM_LOAD (8):
4419 CASE_BUILT_IN_TM_LOAD (FLOAT
):
4420 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
4421 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
4422 CASE_BUILT_IN_TM_LOAD (M64
):
4423 CASE_BUILT_IN_TM_LOAD (M128
):
4424 CASE_BUILT_IN_TM_LOAD (M256
):
4426 tree dest
= gimple_call_lhs (t
);
4427 tree addr
= gimple_call_arg (t
, 0);
4429 get_constraint_for (dest
, &lhsc
);
4430 get_constraint_for (addr
, &rhsc
);
4432 process_all_all_constraints (lhsc
, rhsc
);
4435 /* Variadic argument handling needs to be handled in IPA
4437 case BUILT_IN_VA_START
:
4439 tree valist
= gimple_call_arg (t
, 0);
4440 struct constraint_expr rhs
, *lhsp
;
4442 get_constraint_for (valist
, &lhsc
);
4444 /* The va_list gets access to pointers in variadic
4445 arguments. Which we know in the case of IPA analysis
4446 and otherwise are just all nonlocal variables. */
4449 fi
= lookup_vi_for_tree (fn
->decl
);
4450 rhs
= get_function_part_constraint (fi
, ~0);
4451 rhs
.type
= ADDRESSOF
;
4455 rhs
.var
= nonlocal_id
;
4456 rhs
.type
= ADDRESSOF
;
4459 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
4460 process_constraint (new_constraint (*lhsp
, rhs
));
4461 /* va_list is clobbered. */
4462 make_constraint_to (get_call_clobber_vi (t
)->id
, valist
);
4465 /* va_end doesn't have any effect that matters. */
4466 case BUILT_IN_VA_END
:
4468 /* Alternate return. Simply give up for now. */
4469 case BUILT_IN_RETURN
:
4473 || !(fi
= get_vi_for_tree (fn
->decl
)))
4474 make_constraint_from (get_varinfo (escaped_id
), anything_id
);
4475 else if (in_ipa_mode
4478 struct constraint_expr lhs
, rhs
;
4479 lhs
= get_function_part_constraint (fi
, fi_result
);
4480 rhs
.var
= anything_id
;
4483 process_constraint (new_constraint (lhs
, rhs
));
4487 /* printf-style functions may have hooks to set pointers to
4488 point to somewhere into the generated string. Leave them
4489 for a later exercise... */
4491 /* Fallthru to general call handling. */;
4497 /* Create constraints for the call T. */
4500 find_func_aliases_for_call (struct function
*fn
, gcall
*t
)
4502 tree fndecl
= gimple_call_fndecl (t
);
4505 if (fndecl
!= NULL_TREE
4506 && DECL_BUILT_IN (fndecl
)
4507 && find_func_aliases_for_builtin_call (fn
, t
))
4510 fi
= get_fi_for_callee (t
);
4512 || (fndecl
&& !fi
->is_fn_info
))
4514 auto_vec
<ce_s
, 16> rhsc
;
4515 int flags
= gimple_call_flags (t
);
4517 /* Const functions can return their arguments and addresses
4518 of global memory but not of escaped memory. */
4519 if (flags
& (ECF_CONST
|ECF_NOVOPS
))
4521 if (gimple_call_lhs (t
))
4522 handle_const_call (t
, &rhsc
);
4524 /* Pure functions can return addresses in and of memory
4525 reachable from their arguments, but they are not an escape
4526 point for reachable memory of their arguments. */
4527 else if (flags
& (ECF_PURE
|ECF_LOOPING_CONST_OR_PURE
))
4528 handle_pure_call (t
, &rhsc
);
4530 handle_rhs_call (t
, &rhsc
);
4531 if (gimple_call_lhs (t
))
4532 handle_lhs_call (t
, gimple_call_lhs (t
),
4533 gimple_call_return_flags (t
), rhsc
, fndecl
);
4537 auto_vec
<ce_s
, 2> rhsc
;
4541 /* Assign all the passed arguments to the appropriate incoming
4542 parameters of the function. */
4543 for (j
= 0; j
< gimple_call_num_args (t
); j
++)
4545 struct constraint_expr lhs
;
4546 struct constraint_expr
*rhsp
;
4547 tree arg
= gimple_call_arg (t
, j
);
4549 get_constraint_for_rhs (arg
, &rhsc
);
4550 lhs
= get_function_part_constraint (fi
, fi_parm_base
+ j
);
4551 while (rhsc
.length () != 0)
4553 rhsp
= &rhsc
.last ();
4554 process_constraint (new_constraint (lhs
, *rhsp
));
4559 /* If we are returning a value, assign it to the result. */
4560 lhsop
= gimple_call_lhs (t
);
4563 auto_vec
<ce_s
, 2> lhsc
;
4564 struct constraint_expr rhs
;
4565 struct constraint_expr
*lhsp
;
4567 get_constraint_for (lhsop
, &lhsc
);
4568 rhs
= get_function_part_constraint (fi
, fi_result
);
4570 && DECL_RESULT (fndecl
)
4571 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
4573 auto_vec
<ce_s
, 2> tem
;
4574 tem
.quick_push (rhs
);
4576 gcc_checking_assert (tem
.length () == 1);
4579 FOR_EACH_VEC_ELT (lhsc
, j
, lhsp
)
4580 process_constraint (new_constraint (*lhsp
, rhs
));
4583 /* If we pass the result decl by reference, honor that. */
4586 && DECL_RESULT (fndecl
)
4587 && DECL_BY_REFERENCE (DECL_RESULT (fndecl
)))
4589 struct constraint_expr lhs
;
4590 struct constraint_expr
*rhsp
;
4592 get_constraint_for_address_of (lhsop
, &rhsc
);
4593 lhs
= get_function_part_constraint (fi
, fi_result
);
4594 FOR_EACH_VEC_ELT (rhsc
, j
, rhsp
)
4595 process_constraint (new_constraint (lhs
, *rhsp
));
4599 /* If we use a static chain, pass it along. */
4600 if (gimple_call_chain (t
))
4602 struct constraint_expr lhs
;
4603 struct constraint_expr
*rhsp
;
4605 get_constraint_for (gimple_call_chain (t
), &rhsc
);
4606 lhs
= get_function_part_constraint (fi
, fi_static_chain
);
4607 FOR_EACH_VEC_ELT (rhsc
, j
, rhsp
)
4608 process_constraint (new_constraint (lhs
, *rhsp
));
4613 /* Walk statement T setting up aliasing constraints according to the
4614 references found in T. This function is the main part of the
4615 constraint builder. AI points to auxiliary alias information used
4616 when building alias sets and computing alias grouping heuristics. */
4619 find_func_aliases (struct function
*fn
, gimple
*origt
)
4622 auto_vec
<ce_s
, 16> lhsc
;
4623 auto_vec
<ce_s
, 16> rhsc
;
4624 struct constraint_expr
*c
;
4627 /* Now build constraints expressions. */
4628 if (gimple_code (t
) == GIMPLE_PHI
)
4633 /* For a phi node, assign all the arguments to
4635 get_constraint_for (gimple_phi_result (t
), &lhsc
);
4636 for (i
= 0; i
< gimple_phi_num_args (t
); i
++)
4638 tree strippedrhs
= PHI_ARG_DEF (t
, i
);
4640 STRIP_NOPS (strippedrhs
);
4641 get_constraint_for_rhs (gimple_phi_arg_def (t
, i
), &rhsc
);
4643 FOR_EACH_VEC_ELT (lhsc
, j
, c
)
4645 struct constraint_expr
*c2
;
4646 while (rhsc
.length () > 0)
4649 process_constraint (new_constraint (*c
, *c2
));
4655 /* In IPA mode, we need to generate constraints to pass call
4656 arguments through their calls. There are two cases,
4657 either a GIMPLE_CALL returning a value, or just a plain
4658 GIMPLE_CALL when we are not.
4660 In non-ipa mode, we need to generate constraints for each
4661 pointer passed by address. */
4662 else if (is_gimple_call (t
))
4663 find_func_aliases_for_call (fn
, as_a
<gcall
*> (t
));
4665 /* Otherwise, just a regular assignment statement. Only care about
4666 operations with pointer result, others are dealt with as escape
4667 points if they have pointer operands. */
4668 else if (is_gimple_assign (t
))
4670 /* Otherwise, just a regular assignment statement. */
4671 tree lhsop
= gimple_assign_lhs (t
);
4672 tree rhsop
= (gimple_num_ops (t
) == 2) ? gimple_assign_rhs1 (t
) : NULL
;
4674 if (rhsop
&& TREE_CLOBBER_P (rhsop
))
4675 /* Ignore clobbers, they don't actually store anything into
4678 else if (rhsop
&& AGGREGATE_TYPE_P (TREE_TYPE (lhsop
)))
4679 do_structure_copy (lhsop
, rhsop
);
4682 enum tree_code code
= gimple_assign_rhs_code (t
);
4684 get_constraint_for (lhsop
, &lhsc
);
4686 if (code
== POINTER_PLUS_EXPR
)
4687 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t
),
4688 gimple_assign_rhs2 (t
), &rhsc
);
4689 else if (code
== BIT_AND_EXPR
4690 && TREE_CODE (gimple_assign_rhs2 (t
)) == INTEGER_CST
)
4692 /* Aligning a pointer via a BIT_AND_EXPR is offsetting
4693 the pointer. Handle it by offsetting it by UNKNOWN. */
4694 get_constraint_for_ptr_offset (gimple_assign_rhs1 (t
),
4697 else if ((CONVERT_EXPR_CODE_P (code
)
4698 && !(POINTER_TYPE_P (gimple_expr_type (t
))
4699 && !POINTER_TYPE_P (TREE_TYPE (rhsop
))))
4700 || gimple_assign_single_p (t
))
4701 get_constraint_for_rhs (rhsop
, &rhsc
);
4702 else if (code
== COND_EXPR
)
4704 /* The result is a merge of both COND_EXPR arms. */
4705 auto_vec
<ce_s
, 2> tmp
;
4706 struct constraint_expr
*rhsp
;
4708 get_constraint_for_rhs (gimple_assign_rhs2 (t
), &rhsc
);
4709 get_constraint_for_rhs (gimple_assign_rhs3 (t
), &tmp
);
4710 FOR_EACH_VEC_ELT (tmp
, i
, rhsp
)
4711 rhsc
.safe_push (*rhsp
);
4713 else if (truth_value_p (code
))
4714 /* Truth value results are not pointer (parts). Or at least
4715 very unreasonable obfuscation of a part. */
4719 /* All other operations are merges. */
4720 auto_vec
<ce_s
, 4> tmp
;
4721 struct constraint_expr
*rhsp
;
4723 get_constraint_for_rhs (gimple_assign_rhs1 (t
), &rhsc
);
4724 for (i
= 2; i
< gimple_num_ops (t
); ++i
)
4726 get_constraint_for_rhs (gimple_op (t
, i
), &tmp
);
4727 FOR_EACH_VEC_ELT (tmp
, j
, rhsp
)
4728 rhsc
.safe_push (*rhsp
);
4732 process_all_all_constraints (lhsc
, rhsc
);
4734 /* If there is a store to a global variable the rhs escapes. */
4735 if ((lhsop
= get_base_address (lhsop
)) != NULL_TREE
4737 && is_global_var (lhsop
)
4739 || DECL_EXTERNAL (lhsop
) || TREE_PUBLIC (lhsop
)))
4740 make_escape_constraint (rhsop
);
4742 /* Handle escapes through return. */
4743 else if (gimple_code (t
) == GIMPLE_RETURN
4744 && gimple_return_retval (as_a
<greturn
*> (t
)) != NULL_TREE
)
4746 greturn
*return_stmt
= as_a
<greturn
*> (t
);
4749 || !(fi
= get_vi_for_tree (fn
->decl
)))
4750 make_escape_constraint (gimple_return_retval (return_stmt
));
4751 else if (in_ipa_mode
4754 struct constraint_expr lhs
;
4755 struct constraint_expr
*rhsp
;
4758 lhs
= get_function_part_constraint (fi
, fi_result
);
4759 get_constraint_for_rhs (gimple_return_retval (return_stmt
), &rhsc
);
4760 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4761 process_constraint (new_constraint (lhs
, *rhsp
));
4764 /* Handle asms conservatively by adding escape constraints to everything. */
4765 else if (gasm
*asm_stmt
= dyn_cast
<gasm
*> (t
))
4767 unsigned i
, noutputs
;
4768 const char **oconstraints
;
4769 const char *constraint
;
4770 bool allows_mem
, allows_reg
, is_inout
;
4772 noutputs
= gimple_asm_noutputs (asm_stmt
);
4773 oconstraints
= XALLOCAVEC (const char *, noutputs
);
4775 for (i
= 0; i
< noutputs
; ++i
)
4777 tree link
= gimple_asm_output_op (asm_stmt
, i
);
4778 tree op
= TREE_VALUE (link
);
4780 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
4781 oconstraints
[i
] = constraint
;
4782 parse_output_constraint (&constraint
, i
, 0, 0, &allows_mem
,
4783 &allows_reg
, &is_inout
);
4785 /* A memory constraint makes the address of the operand escape. */
4786 if (!allows_reg
&& allows_mem
)
4787 make_escape_constraint (build_fold_addr_expr (op
));
4789 /* The asm may read global memory, so outputs may point to
4790 any global memory. */
4793 auto_vec
<ce_s
, 2> lhsc
;
4794 struct constraint_expr rhsc
, *lhsp
;
4796 get_constraint_for (op
, &lhsc
);
4797 rhsc
.var
= nonlocal_id
;
4800 FOR_EACH_VEC_ELT (lhsc
, j
, lhsp
)
4801 process_constraint (new_constraint (*lhsp
, rhsc
));
4804 for (i
= 0; i
< gimple_asm_ninputs (asm_stmt
); ++i
)
4806 tree link
= gimple_asm_input_op (asm_stmt
, i
);
4807 tree op
= TREE_VALUE (link
);
4809 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
4811 parse_input_constraint (&constraint
, 0, 0, noutputs
, 0, oconstraints
,
4812 &allows_mem
, &allows_reg
);
4814 /* A memory constraint makes the address of the operand escape. */
4815 if (!allows_reg
&& allows_mem
)
4816 make_escape_constraint (build_fold_addr_expr (op
));
4817 /* Strictly we'd only need the constraint to ESCAPED if
4818 the asm clobbers memory, otherwise using something
4819 along the lines of per-call clobbers/uses would be enough. */
4821 make_escape_constraint (op
);
4827 /* Create a constraint adding to the clobber set of FI the memory
4828 pointed to by PTR. */
4831 process_ipa_clobber (varinfo_t fi
, tree ptr
)
4833 vec
<ce_s
> ptrc
= vNULL
;
4834 struct constraint_expr
*c
, lhs
;
4836 get_constraint_for_rhs (ptr
, &ptrc
);
4837 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4838 FOR_EACH_VEC_ELT (ptrc
, i
, c
)
4839 process_constraint (new_constraint (lhs
, *c
));
4843 /* Walk statement T setting up clobber and use constraints according to the
4844 references found in T. This function is a main part of the
4845 IPA constraint builder. */
4848 find_func_clobbers (struct function
*fn
, gimple
*origt
)
4851 auto_vec
<ce_s
, 16> lhsc
;
4852 auto_vec
<ce_s
, 16> rhsc
;
4855 /* Add constraints for clobbered/used in IPA mode.
4856 We are not interested in what automatic variables are clobbered
4857 or used as we only use the information in the caller to which
4858 they do not escape. */
4859 gcc_assert (in_ipa_mode
);
4861 /* If the stmt refers to memory in any way it better had a VUSE. */
4862 if (gimple_vuse (t
) == NULL_TREE
)
4865 /* We'd better have function information for the current function. */
4866 fi
= lookup_vi_for_tree (fn
->decl
);
4867 gcc_assert (fi
!= NULL
);
4869 /* Account for stores in assignments and calls. */
4870 if (gimple_vdef (t
) != NULL_TREE
4871 && gimple_has_lhs (t
))
4873 tree lhs
= gimple_get_lhs (t
);
4875 while (handled_component_p (tem
))
4876 tem
= TREE_OPERAND (tem
, 0);
4878 && !auto_var_in_fn_p (tem
, fn
->decl
))
4879 || INDIRECT_REF_P (tem
)
4880 || (TREE_CODE (tem
) == MEM_REF
4881 && !(TREE_CODE (TREE_OPERAND (tem
, 0)) == ADDR_EXPR
4883 (TREE_OPERAND (TREE_OPERAND (tem
, 0), 0), fn
->decl
))))
4885 struct constraint_expr lhsc
, *rhsp
;
4887 lhsc
= get_function_part_constraint (fi
, fi_clobbers
);
4888 get_constraint_for_address_of (lhs
, &rhsc
);
4889 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4890 process_constraint (new_constraint (lhsc
, *rhsp
));
4895 /* Account for uses in assigments and returns. */
4896 if (gimple_assign_single_p (t
)
4897 || (gimple_code (t
) == GIMPLE_RETURN
4898 && gimple_return_retval (as_a
<greturn
*> (t
)) != NULL_TREE
))
4900 tree rhs
= (gimple_assign_single_p (t
)
4901 ? gimple_assign_rhs1 (t
)
4902 : gimple_return_retval (as_a
<greturn
*> (t
)));
4904 while (handled_component_p (tem
))
4905 tem
= TREE_OPERAND (tem
, 0);
4907 && !auto_var_in_fn_p (tem
, fn
->decl
))
4908 || INDIRECT_REF_P (tem
)
4909 || (TREE_CODE (tem
) == MEM_REF
4910 && !(TREE_CODE (TREE_OPERAND (tem
, 0)) == ADDR_EXPR
4912 (TREE_OPERAND (TREE_OPERAND (tem
, 0), 0), fn
->decl
))))
4914 struct constraint_expr lhs
, *rhsp
;
4916 lhs
= get_function_part_constraint (fi
, fi_uses
);
4917 get_constraint_for_address_of (rhs
, &rhsc
);
4918 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4919 process_constraint (new_constraint (lhs
, *rhsp
));
4924 if (gcall
*call_stmt
= dyn_cast
<gcall
*> (t
))
4926 varinfo_t cfi
= NULL
;
4927 tree decl
= gimple_call_fndecl (t
);
4928 struct constraint_expr lhs
, rhs
;
4931 /* For builtins we do not have separate function info. For those
4932 we do not generate escapes for we have to generate clobbers/uses. */
4933 if (gimple_call_builtin_p (t
, BUILT_IN_NORMAL
))
4934 switch (DECL_FUNCTION_CODE (decl
))
4936 /* The following functions use and clobber memory pointed to
4937 by their arguments. */
4938 case BUILT_IN_STRCPY
:
4939 case BUILT_IN_STRNCPY
:
4940 case BUILT_IN_BCOPY
:
4941 case BUILT_IN_MEMCPY
:
4942 case BUILT_IN_MEMMOVE
:
4943 case BUILT_IN_MEMPCPY
:
4944 case BUILT_IN_STPCPY
:
4945 case BUILT_IN_STPNCPY
:
4946 case BUILT_IN_STRCAT
:
4947 case BUILT_IN_STRNCAT
:
4948 case BUILT_IN_STRCPY_CHK
:
4949 case BUILT_IN_STRNCPY_CHK
:
4950 case BUILT_IN_MEMCPY_CHK
:
4951 case BUILT_IN_MEMMOVE_CHK
:
4952 case BUILT_IN_MEMPCPY_CHK
:
4953 case BUILT_IN_STPCPY_CHK
:
4954 case BUILT_IN_STPNCPY_CHK
:
4955 case BUILT_IN_STRCAT_CHK
:
4956 case BUILT_IN_STRNCAT_CHK
:
4958 tree dest
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (decl
)
4959 == BUILT_IN_BCOPY
? 1 : 0));
4960 tree src
= gimple_call_arg (t
, (DECL_FUNCTION_CODE (decl
)
4961 == BUILT_IN_BCOPY
? 0 : 1));
4963 struct constraint_expr
*rhsp
, *lhsp
;
4964 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4965 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4966 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
4967 process_constraint (new_constraint (lhs
, *lhsp
));
4968 get_constraint_for_ptr_offset (src
, NULL_TREE
, &rhsc
);
4969 lhs
= get_function_part_constraint (fi
, fi_uses
);
4970 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
4971 process_constraint (new_constraint (lhs
, *rhsp
));
4974 /* The following function clobbers memory pointed to by
4976 case BUILT_IN_MEMSET
:
4977 case BUILT_IN_MEMSET_CHK
:
4978 case BUILT_IN_POSIX_MEMALIGN
:
4980 tree dest
= gimple_call_arg (t
, 0);
4983 get_constraint_for_ptr_offset (dest
, NULL_TREE
, &lhsc
);
4984 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
4985 FOR_EACH_VEC_ELT (lhsc
, i
, lhsp
)
4986 process_constraint (new_constraint (lhs
, *lhsp
));
4989 /* The following functions clobber their second and third
4991 case BUILT_IN_SINCOS
:
4992 case BUILT_IN_SINCOSF
:
4993 case BUILT_IN_SINCOSL
:
4995 process_ipa_clobber (fi
, gimple_call_arg (t
, 1));
4996 process_ipa_clobber (fi
, gimple_call_arg (t
, 2));
4999 /* The following functions clobber their second argument. */
5000 case BUILT_IN_FREXP
:
5001 case BUILT_IN_FREXPF
:
5002 case BUILT_IN_FREXPL
:
5003 case BUILT_IN_LGAMMA_R
:
5004 case BUILT_IN_LGAMMAF_R
:
5005 case BUILT_IN_LGAMMAL_R
:
5006 case BUILT_IN_GAMMA_R
:
5007 case BUILT_IN_GAMMAF_R
:
5008 case BUILT_IN_GAMMAL_R
:
5010 case BUILT_IN_MODFF
:
5011 case BUILT_IN_MODFL
:
5013 process_ipa_clobber (fi
, gimple_call_arg (t
, 1));
5016 /* The following functions clobber their third argument. */
5017 case BUILT_IN_REMQUO
:
5018 case BUILT_IN_REMQUOF
:
5019 case BUILT_IN_REMQUOL
:
5021 process_ipa_clobber (fi
, gimple_call_arg (t
, 2));
5024 /* The following functions neither read nor clobber memory. */
5025 case BUILT_IN_ASSUME_ALIGNED
:
5028 /* Trampolines are of no interest to us. */
5029 case BUILT_IN_INIT_TRAMPOLINE
:
5030 case BUILT_IN_ADJUST_TRAMPOLINE
:
5032 case BUILT_IN_VA_START
:
5033 case BUILT_IN_VA_END
:
5035 /* printf-style functions may have hooks to set pointers to
5036 point to somewhere into the generated string. Leave them
5037 for a later exercise... */
5039 /* Fallthru to general call handling. */;
5042 /* Parameters passed by value are used. */
5043 lhs
= get_function_part_constraint (fi
, fi_uses
);
5044 for (i
= 0; i
< gimple_call_num_args (t
); i
++)
5046 struct constraint_expr
*rhsp
;
5047 tree arg
= gimple_call_arg (t
, i
);
5049 if (TREE_CODE (arg
) == SSA_NAME
5050 || is_gimple_min_invariant (arg
))
5053 get_constraint_for_address_of (arg
, &rhsc
);
5054 FOR_EACH_VEC_ELT (rhsc
, j
, rhsp
)
5055 process_constraint (new_constraint (lhs
, *rhsp
));
5059 /* Build constraints for propagating clobbers/uses along the
5061 cfi
= get_fi_for_callee (call_stmt
);
5062 if (cfi
->id
== anything_id
)
5064 if (gimple_vdef (t
))
5065 make_constraint_from (first_vi_for_offset (fi
, fi_clobbers
),
5067 make_constraint_from (first_vi_for_offset (fi
, fi_uses
),
5072 /* For callees without function info (that's external functions),
5073 ESCAPED is clobbered and used. */
5074 if (gimple_call_fndecl (t
)
5075 && !cfi
->is_fn_info
)
5079 if (gimple_vdef (t
))
5080 make_copy_constraint (first_vi_for_offset (fi
, fi_clobbers
),
5082 make_copy_constraint (first_vi_for_offset (fi
, fi_uses
), escaped_id
);
5084 /* Also honor the call statement use/clobber info. */
5085 if ((vi
= lookup_call_clobber_vi (call_stmt
)) != NULL
)
5086 make_copy_constraint (first_vi_for_offset (fi
, fi_clobbers
),
5088 if ((vi
= lookup_call_use_vi (call_stmt
)) != NULL
)
5089 make_copy_constraint (first_vi_for_offset (fi
, fi_uses
),
5094 /* Otherwise the caller clobbers and uses what the callee does.
5095 ??? This should use a new complex constraint that filters
5096 local variables of the callee. */
5097 if (gimple_vdef (t
))
5099 lhs
= get_function_part_constraint (fi
, fi_clobbers
);
5100 rhs
= get_function_part_constraint (cfi
, fi_clobbers
);
5101 process_constraint (new_constraint (lhs
, rhs
));
5103 lhs
= get_function_part_constraint (fi
, fi_uses
);
5104 rhs
= get_function_part_constraint (cfi
, fi_uses
);
5105 process_constraint (new_constraint (lhs
, rhs
));
5107 else if (gimple_code (t
) == GIMPLE_ASM
)
5109 /* ??? Ick. We can do better. */
5110 if (gimple_vdef (t
))
5111 make_constraint_from (first_vi_for_offset (fi
, fi_clobbers
),
5113 make_constraint_from (first_vi_for_offset (fi
, fi_uses
),
5119 /* Find the first varinfo in the same variable as START that overlaps with
5120 OFFSET. Return NULL if we can't find one. */
5123 first_vi_for_offset (varinfo_t start
, unsigned HOST_WIDE_INT offset
)
5125 /* If the offset is outside of the variable, bail out. */
5126 if (offset
>= start
->fullsize
)
5129 /* If we cannot reach offset from start, lookup the first field
5130 and start from there. */
5131 if (start
->offset
> offset
)
5132 start
= get_varinfo (start
->head
);
5136 /* We may not find a variable in the field list with the actual
5137 offset when we have glommed a structure to a variable.
5138 In that case, however, offset should still be within the size
5140 if (offset
>= start
->offset
5141 && (offset
- start
->offset
) < start
->size
)
5144 start
= vi_next (start
);
5150 /* Find the first varinfo in the same variable as START that overlaps with
5151 OFFSET. If there is no such varinfo the varinfo directly preceding
5152 OFFSET is returned. */
5155 first_or_preceding_vi_for_offset (varinfo_t start
,
5156 unsigned HOST_WIDE_INT offset
)
5158 /* If we cannot reach offset from start, lookup the first field
5159 and start from there. */
5160 if (start
->offset
> offset
)
5161 start
= get_varinfo (start
->head
);
5163 /* We may not find a variable in the field list with the actual
5164 offset when we have glommed a structure to a variable.
5165 In that case, however, offset should still be within the size
5167 If we got beyond the offset we look for return the field
5168 directly preceding offset which may be the last field. */
5170 && offset
>= start
->offset
5171 && !((offset
- start
->offset
) < start
->size
))
5172 start
= vi_next (start
);
5178 /* This structure is used during pushing fields onto the fieldstack
5179 to track the offset of the field, since bitpos_of_field gives it
5180 relative to its immediate containing type, and we want it relative
5181 to the ultimate containing object. */
5185 /* Offset from the base of the base containing object to this field. */
5186 HOST_WIDE_INT offset
;
5188 /* Size, in bits, of the field. */
5189 unsigned HOST_WIDE_INT size
;
5191 unsigned has_unknown_size
: 1;
5193 unsigned must_have_pointers
: 1;
5195 unsigned may_have_pointers
: 1;
5197 unsigned only_restrict_pointers
: 1;
5199 tree restrict_pointed_type
;
5201 typedef struct fieldoff fieldoff_s
;
5204 /* qsort comparison function for two fieldoff's PA and PB */
5207 fieldoff_compare (const void *pa
, const void *pb
)
5209 const fieldoff_s
*foa
= (const fieldoff_s
*)pa
;
5210 const fieldoff_s
*fob
= (const fieldoff_s
*)pb
;
5211 unsigned HOST_WIDE_INT foasize
, fobsize
;
5213 if (foa
->offset
< fob
->offset
)
5215 else if (foa
->offset
> fob
->offset
)
5218 foasize
= foa
->size
;
5219 fobsize
= fob
->size
;
5220 if (foasize
< fobsize
)
5222 else if (foasize
> fobsize
)
5227 /* Sort a fieldstack according to the field offset and sizes. */
5229 sort_fieldstack (vec
<fieldoff_s
> fieldstack
)
5231 fieldstack
.qsort (fieldoff_compare
);
5234 /* Return true if T is a type that can have subvars. */
5237 type_can_have_subvars (const_tree t
)
5239 /* Aggregates without overlapping fields can have subvars. */
5240 return TREE_CODE (t
) == RECORD_TYPE
;
5243 /* Return true if V is a tree that we can have subvars for.
5244 Normally, this is any aggregate type. Also complex
5245 types which are not gimple registers can have subvars. */
5248 var_can_have_subvars (const_tree v
)
5250 /* Volatile variables should never have subvars. */
5251 if (TREE_THIS_VOLATILE (v
))
5254 /* Non decls or memory tags can never have subvars. */
5258 return type_can_have_subvars (TREE_TYPE (v
));
5261 /* Return true if T is a type that does contain pointers. */
5264 type_must_have_pointers (tree type
)
5266 if (POINTER_TYPE_P (type
))
5269 if (TREE_CODE (type
) == ARRAY_TYPE
)
5270 return type_must_have_pointers (TREE_TYPE (type
));
5272 /* A function or method can have pointers as arguments, so track
5273 those separately. */
5274 if (TREE_CODE (type
) == FUNCTION_TYPE
5275 || TREE_CODE (type
) == METHOD_TYPE
)
5282 field_must_have_pointers (tree t
)
5284 return type_must_have_pointers (TREE_TYPE (t
));
5287 /* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
5288 the fields of TYPE onto fieldstack, recording their offsets along
5291 OFFSET is used to keep track of the offset in this entire
5292 structure, rather than just the immediately containing structure.
5293 Returns false if the caller is supposed to handle the field we
5297 push_fields_onto_fieldstack (tree type
, vec
<fieldoff_s
> *fieldstack
,
5298 HOST_WIDE_INT offset
)
5301 bool empty_p
= true;
5303 if (TREE_CODE (type
) != RECORD_TYPE
)
5306 /* If the vector of fields is growing too big, bail out early.
5307 Callers check for vec::length <= MAX_FIELDS_FOR_FIELD_SENSITIVE, make
5309 if (fieldstack
->length () > MAX_FIELDS_FOR_FIELD_SENSITIVE
)
5312 for (field
= TYPE_FIELDS (type
); field
; field
= DECL_CHAIN (field
))
5313 if (TREE_CODE (field
) == FIELD_DECL
)
5316 HOST_WIDE_INT foff
= bitpos_of_field (field
);
5317 tree field_type
= TREE_TYPE (field
);
5319 if (!var_can_have_subvars (field
)
5320 || TREE_CODE (field_type
) == QUAL_UNION_TYPE
5321 || TREE_CODE (field_type
) == UNION_TYPE
)
5323 else if (!push_fields_onto_fieldstack
5324 (field_type
, fieldstack
, offset
+ foff
)
5325 && (DECL_SIZE (field
)
5326 && !integer_zerop (DECL_SIZE (field
))))
5327 /* Empty structures may have actual size, like in C++. So
5328 see if we didn't push any subfields and the size is
5329 nonzero, push the field onto the stack. */
5334 fieldoff_s
*pair
= NULL
;
5335 bool has_unknown_size
= false;
5336 bool must_have_pointers_p
;
5338 if (!fieldstack
->is_empty ())
5339 pair
= &fieldstack
->last ();
5341 /* If there isn't anything at offset zero, create sth. */
5343 && offset
+ foff
!= 0)
5346 = {0, offset
+ foff
, false, false, false, false, NULL_TREE
};
5347 pair
= fieldstack
->safe_push (e
);
5350 if (!DECL_SIZE (field
)
5351 || !tree_fits_uhwi_p (DECL_SIZE (field
)))
5352 has_unknown_size
= true;
5354 /* If adjacent fields do not contain pointers merge them. */
5355 must_have_pointers_p
= field_must_have_pointers (field
);
5357 && !has_unknown_size
5358 && !must_have_pointers_p
5359 && !pair
->must_have_pointers
5360 && !pair
->has_unknown_size
5361 && pair
->offset
+ (HOST_WIDE_INT
)pair
->size
== offset
+ foff
)
5363 pair
->size
+= tree_to_uhwi (DECL_SIZE (field
));
5368 e
.offset
= offset
+ foff
;
5369 e
.has_unknown_size
= has_unknown_size
;
5370 if (!has_unknown_size
)
5371 e
.size
= tree_to_uhwi (DECL_SIZE (field
));
5374 e
.must_have_pointers
= must_have_pointers_p
;
5375 e
.may_have_pointers
= true;
5376 e
.only_restrict_pointers
5377 = (!has_unknown_size
5378 && POINTER_TYPE_P (field_type
)
5379 && TYPE_RESTRICT (field_type
));
5380 if (e
.only_restrict_pointers
)
5381 e
.restrict_pointed_type
= TREE_TYPE (field_type
);
5382 fieldstack
->safe_push (e
);
5392 /* Count the number of arguments DECL has, and set IS_VARARGS to true
5393 if it is a varargs function. */
5396 count_num_arguments (tree decl
, bool *is_varargs
)
5398 unsigned int num
= 0;
5401 /* Capture named arguments for K&R functions. They do not
5402 have a prototype and thus no TYPE_ARG_TYPES. */
5403 for (t
= DECL_ARGUMENTS (decl
); t
; t
= DECL_CHAIN (t
))
5406 /* Check if the function has variadic arguments. */
5407 for (t
= TYPE_ARG_TYPES (TREE_TYPE (decl
)); t
; t
= TREE_CHAIN (t
))
5408 if (TREE_VALUE (t
) == void_type_node
)
5416 /* Creation function node for DECL, using NAME, and return the index
5417 of the variable we've created for the function. If NONLOCAL_p, create
5418 initial constraints. */
5421 create_function_info_for (tree decl
, const char *name
, bool add_id
,
5424 struct function
*fn
= DECL_STRUCT_FUNCTION (decl
);
5425 varinfo_t vi
, prev_vi
;
5428 bool is_varargs
= false;
5429 unsigned int num_args
= count_num_arguments (decl
, &is_varargs
);
5431 /* Create the variable info. */
5433 vi
= new_var_info (decl
, name
, add_id
);
5436 vi
->fullsize
= fi_parm_base
+ num_args
;
5438 vi
->may_have_pointers
= false;
5441 insert_vi_for_tree (vi
->decl
, vi
);
5445 /* Create a variable for things the function clobbers and one for
5446 things the function uses. */
5448 varinfo_t clobbervi
, usevi
;
5449 const char *newname
;
5452 tempname
= xasprintf ("%s.clobber", name
);
5453 newname
= ggc_strdup (tempname
);
5456 clobbervi
= new_var_info (NULL
, newname
, false);
5457 clobbervi
->offset
= fi_clobbers
;
5458 clobbervi
->size
= 1;
5459 clobbervi
->fullsize
= vi
->fullsize
;
5460 clobbervi
->is_full_var
= true;
5461 clobbervi
->is_global_var
= false;
5463 gcc_assert (prev_vi
->offset
< clobbervi
->offset
);
5464 prev_vi
->next
= clobbervi
->id
;
5465 prev_vi
= clobbervi
;
5467 tempname
= xasprintf ("%s.use", name
);
5468 newname
= ggc_strdup (tempname
);
5471 usevi
= new_var_info (NULL
, newname
, false);
5472 usevi
->offset
= fi_uses
;
5474 usevi
->fullsize
= vi
->fullsize
;
5475 usevi
->is_full_var
= true;
5476 usevi
->is_global_var
= false;
5478 gcc_assert (prev_vi
->offset
< usevi
->offset
);
5479 prev_vi
->next
= usevi
->id
;
5483 /* And one for the static chain. */
5484 if (fn
->static_chain_decl
!= NULL_TREE
)
5487 const char *newname
;
5490 tempname
= xasprintf ("%s.chain", name
);
5491 newname
= ggc_strdup (tempname
);
5494 chainvi
= new_var_info (fn
->static_chain_decl
, newname
, false);
5495 chainvi
->offset
= fi_static_chain
;
5497 chainvi
->fullsize
= vi
->fullsize
;
5498 chainvi
->is_full_var
= true;
5499 chainvi
->is_global_var
= false;
5501 insert_vi_for_tree (fn
->static_chain_decl
, chainvi
);
5504 && chainvi
->may_have_pointers
)
5505 make_constraint_from (chainvi
, nonlocal_id
);
5507 gcc_assert (prev_vi
->offset
< chainvi
->offset
);
5508 prev_vi
->next
= chainvi
->id
;
5512 /* Create a variable for the return var. */
5513 if (DECL_RESULT (decl
) != NULL
5514 || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl
))))
5517 const char *newname
;
5519 tree resultdecl
= decl
;
5521 if (DECL_RESULT (decl
))
5522 resultdecl
= DECL_RESULT (decl
);
5524 tempname
= xasprintf ("%s.result", name
);
5525 newname
= ggc_strdup (tempname
);
5528 resultvi
= new_var_info (resultdecl
, newname
, false);
5529 resultvi
->offset
= fi_result
;
5531 resultvi
->fullsize
= vi
->fullsize
;
5532 resultvi
->is_full_var
= true;
5533 if (DECL_RESULT (decl
))
5534 resultvi
->may_have_pointers
= true;
5536 if (DECL_RESULT (decl
))
5537 insert_vi_for_tree (DECL_RESULT (decl
), resultvi
);
5539 gcc_assert (prev_vi
->offset
< resultvi
->offset
);
5540 prev_vi
->next
= resultvi
->id
;
5544 /* We also need to make function return values escape. Nothing
5545 escapes by returning from main though. */
5547 && !MAIN_NAME_P (DECL_NAME (decl
)))
5550 fi
= lookup_vi_for_tree (decl
);
5551 rvi
= first_vi_for_offset (fi
, fi_result
);
5552 if (rvi
&& rvi
->offset
== fi_result
)
5553 make_copy_constraint (get_varinfo (escaped_id
), rvi
->id
);
5556 /* Set up variables for each argument. */
5557 arg
= DECL_ARGUMENTS (decl
);
5558 for (i
= 0; i
< num_args
; i
++)
5561 const char *newname
;
5563 tree argdecl
= decl
;
5568 tempname
= xasprintf ("%s.arg%d", name
, i
);
5569 newname
= ggc_strdup (tempname
);
5572 argvi
= new_var_info (argdecl
, newname
, false);
5573 argvi
->offset
= fi_parm_base
+ i
;
5575 argvi
->is_full_var
= true;
5576 argvi
->fullsize
= vi
->fullsize
;
5578 argvi
->may_have_pointers
= true;
5581 insert_vi_for_tree (arg
, argvi
);
5584 && argvi
->may_have_pointers
)
5585 make_constraint_from (argvi
, nonlocal_id
);
5587 gcc_assert (prev_vi
->offset
< argvi
->offset
);
5588 prev_vi
->next
= argvi
->id
;
5591 arg
= DECL_CHAIN (arg
);
5594 /* Add one representative for all further args. */
5598 const char *newname
;
5602 tempname
= xasprintf ("%s.varargs", name
);
5603 newname
= ggc_strdup (tempname
);
5606 /* We need sth that can be pointed to for va_start. */
5607 decl
= build_fake_var_decl (ptr_type_node
);
5609 argvi
= new_var_info (decl
, newname
, false);
5610 argvi
->offset
= fi_parm_base
+ num_args
;
5612 argvi
->is_full_var
= true;
5613 argvi
->is_heap_var
= true;
5614 argvi
->fullsize
= vi
->fullsize
;
5617 && argvi
->may_have_pointers
)
5618 make_constraint_from (argvi
, nonlocal_id
);
5620 gcc_assert (prev_vi
->offset
< argvi
->offset
);
5621 prev_vi
->next
= argvi
->id
;
5629 /* Return true if FIELDSTACK contains fields that overlap.
5630 FIELDSTACK is assumed to be sorted by offset. */
5633 check_for_overlaps (vec
<fieldoff_s
> fieldstack
)
5635 fieldoff_s
*fo
= NULL
;
5637 HOST_WIDE_INT lastoffset
= -1;
5639 FOR_EACH_VEC_ELT (fieldstack
, i
, fo
)
5641 if (fo
->offset
== lastoffset
)
5643 lastoffset
= fo
->offset
;
5648 /* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
5649 This will also create any varinfo structures necessary for fields
5650 of DECL. DECL is a function parameter if HANDLE_PARAM is set. */
5653 create_variable_info_for_1 (tree decl
, const char *name
, bool add_id
,
5656 varinfo_t vi
, newvi
;
5657 tree decl_type
= TREE_TYPE (decl
);
5658 tree declsize
= DECL_P (decl
) ? DECL_SIZE (decl
) : TYPE_SIZE (decl_type
);
5659 auto_vec
<fieldoff_s
> fieldstack
;
5664 || !tree_fits_uhwi_p (declsize
))
5666 vi
= new_var_info (decl
, name
, add_id
);
5670 vi
->is_unknown_size_var
= true;
5671 vi
->is_full_var
= true;
5672 vi
->may_have_pointers
= true;
5676 /* Collect field information. */
5677 if (use_field_sensitive
5678 && var_can_have_subvars (decl
)
5679 /* ??? Force us to not use subfields for globals in IPA mode.
5680 Else we'd have to parse arbitrary initializers. */
5682 && is_global_var (decl
)))
5684 fieldoff_s
*fo
= NULL
;
5685 bool notokay
= false;
5688 push_fields_onto_fieldstack (decl_type
, &fieldstack
, 0);
5690 for (i
= 0; !notokay
&& fieldstack
.iterate (i
, &fo
); i
++)
5691 if (fo
->has_unknown_size
5698 /* We can't sort them if we have a field with a variable sized type,
5699 which will make notokay = true. In that case, we are going to return
5700 without creating varinfos for the fields anyway, so sorting them is a
5704 sort_fieldstack (fieldstack
);
5705 /* Due to some C++ FE issues, like PR 22488, we might end up
5706 what appear to be overlapping fields even though they,
5707 in reality, do not overlap. Until the C++ FE is fixed,
5708 we will simply disable field-sensitivity for these cases. */
5709 notokay
= check_for_overlaps (fieldstack
);
5713 fieldstack
.release ();
5716 /* If we didn't end up collecting sub-variables create a full
5717 variable for the decl. */
5718 if (fieldstack
.length () == 0
5719 || fieldstack
.length () > MAX_FIELDS_FOR_FIELD_SENSITIVE
)
5721 vi
= new_var_info (decl
, name
, add_id
);
5723 vi
->may_have_pointers
= true;
5724 vi
->fullsize
= tree_to_uhwi (declsize
);
5725 vi
->size
= vi
->fullsize
;
5726 vi
->is_full_var
= true;
5727 if (POINTER_TYPE_P (decl_type
)
5728 && TYPE_RESTRICT (decl_type
))
5729 vi
->only_restrict_pointers
= 1;
5730 if (vi
->only_restrict_pointers
5731 && !type_contains_placeholder_p (TREE_TYPE (decl_type
))
5735 tree heapvar
= build_fake_var_decl (TREE_TYPE (decl_type
));
5736 DECL_EXTERNAL (heapvar
) = 1;
5737 rvi
= create_variable_info_for_1 (heapvar
, "PARM_NOALIAS", true,
5739 rvi
->is_restrict_var
= 1;
5740 insert_vi_for_tree (heapvar
, rvi
);
5741 make_constraint_from (vi
, rvi
->id
);
5742 make_param_constraints (rvi
);
5744 fieldstack
.release ();
5748 vi
= new_var_info (decl
, name
, add_id
);
5749 vi
->fullsize
= tree_to_uhwi (declsize
);
5750 if (fieldstack
.length () == 1)
5751 vi
->is_full_var
= true;
5752 for (i
= 0, newvi
= vi
;
5753 fieldstack
.iterate (i
, &fo
);
5754 ++i
, newvi
= vi_next (newvi
))
5756 const char *newname
= NULL
;
5761 if (fieldstack
.length () != 1)
5764 = xasprintf ("%s." HOST_WIDE_INT_PRINT_DEC
5765 "+" HOST_WIDE_INT_PRINT_DEC
, name
,
5766 fo
->offset
, fo
->size
);
5767 newname
= ggc_strdup (tempname
);
5775 newvi
->name
= newname
;
5776 newvi
->offset
= fo
->offset
;
5777 newvi
->size
= fo
->size
;
5778 newvi
->fullsize
= vi
->fullsize
;
5779 newvi
->may_have_pointers
= fo
->may_have_pointers
;
5780 newvi
->only_restrict_pointers
= fo
->only_restrict_pointers
;
5782 && newvi
->only_restrict_pointers
5783 && !type_contains_placeholder_p (fo
->restrict_pointed_type
))
5786 tree heapvar
= build_fake_var_decl (fo
->restrict_pointed_type
);
5787 DECL_EXTERNAL (heapvar
) = 1;
5788 rvi
= create_variable_info_for_1 (heapvar
, "PARM_NOALIAS", true,
5790 rvi
->is_restrict_var
= 1;
5791 insert_vi_for_tree (heapvar
, rvi
);
5792 make_constraint_from (newvi
, rvi
->id
);
5793 make_param_constraints (rvi
);
5795 if (i
+ 1 < fieldstack
.length ())
5797 varinfo_t tem
= new_var_info (decl
, name
, false);
5798 newvi
->next
= tem
->id
;
5807 create_variable_info_for (tree decl
, const char *name
, bool add_id
)
5809 varinfo_t vi
= create_variable_info_for_1 (decl
, name
, add_id
, false);
5810 unsigned int id
= vi
->id
;
5812 insert_vi_for_tree (decl
, vi
);
5814 if (TREE_CODE (decl
) != VAR_DECL
)
5817 /* Create initial constraints for globals. */
5818 for (; vi
; vi
= vi_next (vi
))
5820 if (!vi
->may_have_pointers
5821 || !vi
->is_global_var
)
5824 /* Mark global restrict qualified pointers. */
5825 if ((POINTER_TYPE_P (TREE_TYPE (decl
))
5826 && TYPE_RESTRICT (TREE_TYPE (decl
)))
5827 || vi
->only_restrict_pointers
)
5830 = make_constraint_from_global_restrict (vi
, "GLOBAL_RESTRICT",
5832 /* ??? For now exclude reads from globals as restrict sources
5833 if those are not (indirectly) from incoming parameters. */
5834 rvi
->is_restrict_var
= false;
5838 /* In non-IPA mode the initializer from nonlocal is all we need. */
5840 || DECL_HARD_REGISTER (decl
))
5841 make_copy_constraint (vi
, nonlocal_id
);
5843 /* In IPA mode parse the initializer and generate proper constraints
5847 varpool_node
*vnode
= varpool_node::get (decl
);
5849 /* For escaped variables initialize them from nonlocal. */
5850 if (!vnode
->all_refs_explicit_p ())
5851 make_copy_constraint (vi
, nonlocal_id
);
5853 /* If this is a global variable with an initializer and we are in
5854 IPA mode generate constraints for it. */
5856 for (unsigned idx
= 0; vnode
->iterate_reference (idx
, ref
); ++idx
)
5858 auto_vec
<ce_s
> rhsc
;
5859 struct constraint_expr lhs
, *rhsp
;
5861 get_constraint_for_address_of (ref
->referred
->decl
, &rhsc
);
5865 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
5866 process_constraint (new_constraint (lhs
, *rhsp
));
5867 /* If this is a variable that escapes from the unit
5868 the initializer escapes as well. */
5869 if (!vnode
->all_refs_explicit_p ())
5871 lhs
.var
= escaped_id
;
5874 FOR_EACH_VEC_ELT (rhsc
, i
, rhsp
)
5875 process_constraint (new_constraint (lhs
, *rhsp
));
5884 /* Print out the points-to solution for VAR to FILE. */
5887 dump_solution_for_var (FILE *file
, unsigned int var
)
5889 varinfo_t vi
= get_varinfo (var
);
5893 /* Dump the solution for unified vars anyway, this avoids difficulties
5894 in scanning dumps in the testsuite. */
5895 fprintf (file
, "%s = { ", vi
->name
);
5896 vi
= get_varinfo (find (var
));
5897 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, i
, bi
)
5898 fprintf (file
, "%s ", get_varinfo (i
)->name
);
5899 fprintf (file
, "}");
5901 /* But note when the variable was unified. */
5903 fprintf (file
, " same as %s", vi
->name
);
5905 fprintf (file
, "\n");
5908 /* Print the points-to solution for VAR to stderr. */
5911 debug_solution_for_var (unsigned int var
)
5913 dump_solution_for_var (stderr
, var
);
5916 /* Register the constraints for function parameter related VI. */
5919 make_param_constraints (varinfo_t vi
)
5921 for (; vi
; vi
= vi_next (vi
))
5923 if (vi
->only_restrict_pointers
)
5925 else if (vi
->may_have_pointers
)
5926 make_constraint_from (vi
, nonlocal_id
);
5928 if (vi
->is_full_var
)
5933 /* Create varinfo structures for all of the variables in the
5934 function for intraprocedural mode. */
5937 intra_create_variable_infos (struct function
*fn
)
5941 /* For each incoming pointer argument arg, create the constraint ARG
5942 = NONLOCAL or a dummy variable if it is a restrict qualified
5943 passed-by-reference argument. */
5944 for (t
= DECL_ARGUMENTS (fn
->decl
); t
; t
= DECL_CHAIN (t
))
5947 = create_variable_info_for_1 (t
, alias_get_name (t
), false, true);
5948 insert_vi_for_tree (t
, p
);
5950 make_param_constraints (p
);
5953 /* Add a constraint for a result decl that is passed by reference. */
5954 if (DECL_RESULT (fn
->decl
)
5955 && DECL_BY_REFERENCE (DECL_RESULT (fn
->decl
)))
5957 varinfo_t p
, result_vi
= get_vi_for_tree (DECL_RESULT (fn
->decl
));
5959 for (p
= result_vi
; p
; p
= vi_next (p
))
5960 make_constraint_from (p
, nonlocal_id
);
5963 /* Add a constraint for the incoming static chain parameter. */
5964 if (fn
->static_chain_decl
!= NULL_TREE
)
5966 varinfo_t p
, chain_vi
= get_vi_for_tree (fn
->static_chain_decl
);
5968 for (p
= chain_vi
; p
; p
= vi_next (p
))
5969 make_constraint_from (p
, nonlocal_id
);
5973 /* Structure used to put solution bitmaps in a hashtable so they can
5974 be shared among variables with the same points-to set. */
5976 typedef struct shared_bitmap_info
5980 } *shared_bitmap_info_t
;
5981 typedef const struct shared_bitmap_info
*const_shared_bitmap_info_t
;
5983 /* Shared_bitmap hashtable helpers. */
5985 struct shared_bitmap_hasher
: free_ptr_hash
<shared_bitmap_info
>
5987 static inline hashval_t
hash (const shared_bitmap_info
*);
5988 static inline bool equal (const shared_bitmap_info
*,
5989 const shared_bitmap_info
*);
5992 /* Hash function for a shared_bitmap_info_t */
5995 shared_bitmap_hasher::hash (const shared_bitmap_info
*bi
)
5997 return bi
->hashcode
;
6000 /* Equality function for two shared_bitmap_info_t's. */
6003 shared_bitmap_hasher::equal (const shared_bitmap_info
*sbi1
,
6004 const shared_bitmap_info
*sbi2
)
6006 return bitmap_equal_p (sbi1
->pt_vars
, sbi2
->pt_vars
);
6009 /* Shared_bitmap hashtable. */
6011 static hash_table
<shared_bitmap_hasher
> *shared_bitmap_table
;
6013 /* Lookup a bitmap in the shared bitmap hashtable, and return an already
6014 existing instance if there is one, NULL otherwise. */
6017 shared_bitmap_lookup (bitmap pt_vars
)
6019 shared_bitmap_info
**slot
;
6020 struct shared_bitmap_info sbi
;
6022 sbi
.pt_vars
= pt_vars
;
6023 sbi
.hashcode
= bitmap_hash (pt_vars
);
6025 slot
= shared_bitmap_table
->find_slot (&sbi
, NO_INSERT
);
6029 return (*slot
)->pt_vars
;
6033 /* Add a bitmap to the shared bitmap hashtable. */
6036 shared_bitmap_add (bitmap pt_vars
)
6038 shared_bitmap_info
**slot
;
6039 shared_bitmap_info_t sbi
= XNEW (struct shared_bitmap_info
);
6041 sbi
->pt_vars
= pt_vars
;
6042 sbi
->hashcode
= bitmap_hash (pt_vars
);
6044 slot
= shared_bitmap_table
->find_slot (sbi
, INSERT
);
6045 gcc_assert (!*slot
);
6050 /* Set bits in INTO corresponding to the variable uids in solution set FROM. */
6053 set_uids_in_ptset (bitmap into
, bitmap from
, struct pt_solution
*pt
)
6057 varinfo_t escaped_vi
= get_varinfo (find (escaped_id
));
6058 bool everything_escaped
6059 = escaped_vi
->solution
&& bitmap_bit_p (escaped_vi
->solution
, anything_id
);
6061 EXECUTE_IF_SET_IN_BITMAP (from
, 0, i
, bi
)
6063 varinfo_t vi
= get_varinfo (i
);
6065 /* The only artificial variables that are allowed in a may-alias
6066 set are heap variables. */
6067 if (vi
->is_artificial_var
&& !vi
->is_heap_var
)
6070 if (everything_escaped
6071 || (escaped_vi
->solution
6072 && bitmap_bit_p (escaped_vi
->solution
, i
)))
6074 pt
->vars_contains_escaped
= true;
6075 pt
->vars_contains_escaped_heap
= vi
->is_heap_var
;
6078 if (TREE_CODE (vi
->decl
) == VAR_DECL
6079 || TREE_CODE (vi
->decl
) == PARM_DECL
6080 || TREE_CODE (vi
->decl
) == RESULT_DECL
)
6082 /* If we are in IPA mode we will not recompute points-to
6083 sets after inlining so make sure they stay valid. */
6085 && !DECL_PT_UID_SET_P (vi
->decl
))
6086 SET_DECL_PT_UID (vi
->decl
, DECL_UID (vi
->decl
));
6088 /* Add the decl to the points-to set. Note that the points-to
6089 set contains global variables. */
6090 bitmap_set_bit (into
, DECL_PT_UID (vi
->decl
));
6091 if (vi
->is_global_var
)
6092 pt
->vars_contains_nonlocal
= true;
6098 /* Compute the points-to solution *PT for the variable VI. */
6100 static struct pt_solution
6101 find_what_var_points_to (varinfo_t orig_vi
)
6105 bitmap finished_solution
;
6108 struct pt_solution
*pt
;
6110 /* This variable may have been collapsed, let's get the real
6112 vi
= get_varinfo (find (orig_vi
->id
));
6114 /* See if we have already computed the solution and return it. */
6115 pt_solution
**slot
= &final_solutions
->get_or_insert (vi
);
6119 *slot
= pt
= XOBNEW (&final_solutions_obstack
, struct pt_solution
);
6120 memset (pt
, 0, sizeof (struct pt_solution
));
6122 /* Translate artificial variables into SSA_NAME_PTR_INFO
6124 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, i
, bi
)
6126 varinfo_t vi
= get_varinfo (i
);
6128 if (vi
->is_artificial_var
)
6130 if (vi
->id
== nothing_id
)
6132 else if (vi
->id
== escaped_id
)
6135 pt
->ipa_escaped
= 1;
6138 /* Expand some special vars of ESCAPED in-place here. */
6139 varinfo_t evi
= get_varinfo (find (escaped_id
));
6140 if (bitmap_bit_p (evi
->solution
, nonlocal_id
))
6143 else if (vi
->id
== nonlocal_id
)
6145 else if (vi
->is_heap_var
)
6146 /* We represent heapvars in the points-to set properly. */
6148 else if (vi
->id
== string_id
)
6149 /* Nobody cares - STRING_CSTs are read-only entities. */
6151 else if (vi
->id
== anything_id
6152 || vi
->id
== integer_id
)
6157 /* Instead of doing extra work, simply do not create
6158 elaborate points-to information for pt_anything pointers. */
6162 /* Share the final set of variables when possible. */
6163 finished_solution
= BITMAP_GGC_ALLOC ();
6164 stats
.points_to_sets_created
++;
6166 set_uids_in_ptset (finished_solution
, vi
->solution
, pt
);
6167 result
= shared_bitmap_lookup (finished_solution
);
6170 shared_bitmap_add (finished_solution
);
6171 pt
->vars
= finished_solution
;
6176 bitmap_clear (finished_solution
);
6182 /* Given a pointer variable P, fill in its points-to set. */
6185 find_what_p_points_to (tree p
)
6187 struct ptr_info_def
*pi
;
6191 /* For parameters, get at the points-to set for the actual parm
6193 if (TREE_CODE (p
) == SSA_NAME
6194 && SSA_NAME_IS_DEFAULT_DEF (p
)
6195 && (TREE_CODE (SSA_NAME_VAR (p
)) == PARM_DECL
6196 || TREE_CODE (SSA_NAME_VAR (p
)) == RESULT_DECL
))
6197 lookup_p
= SSA_NAME_VAR (p
);
6199 vi
= lookup_vi_for_tree (lookup_p
);
6203 pi
= get_ptr_info (p
);
6204 pi
->pt
= find_what_var_points_to (vi
);
6208 /* Query statistics for points-to solutions. */
6211 unsigned HOST_WIDE_INT pt_solution_includes_may_alias
;
6212 unsigned HOST_WIDE_INT pt_solution_includes_no_alias
;
6213 unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias
;
6214 unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias
;
6218 dump_pta_stats (FILE *s
)
6220 fprintf (s
, "\nPTA query stats:\n");
6221 fprintf (s
, " pt_solution_includes: "
6222 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
6223 HOST_WIDE_INT_PRINT_DEC
" queries\n",
6224 pta_stats
.pt_solution_includes_no_alias
,
6225 pta_stats
.pt_solution_includes_no_alias
6226 + pta_stats
.pt_solution_includes_may_alias
);
6227 fprintf (s
, " pt_solutions_intersect: "
6228 HOST_WIDE_INT_PRINT_DEC
" disambiguations, "
6229 HOST_WIDE_INT_PRINT_DEC
" queries\n",
6230 pta_stats
.pt_solutions_intersect_no_alias
,
6231 pta_stats
.pt_solutions_intersect_no_alias
6232 + pta_stats
.pt_solutions_intersect_may_alias
);
6236 /* Reset the points-to solution *PT to a conservative default
6237 (point to anything). */
6240 pt_solution_reset (struct pt_solution
*pt
)
6242 memset (pt
, 0, sizeof (struct pt_solution
));
6243 pt
->anything
= true;
6246 /* Set the points-to solution *PT to point only to the variables
6247 in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
6248 global variables and VARS_CONTAINS_RESTRICT specifies whether
6249 it contains restrict tag variables. */
6252 pt_solution_set (struct pt_solution
*pt
, bitmap vars
,
6253 bool vars_contains_nonlocal
)
6255 memset (pt
, 0, sizeof (struct pt_solution
));
6257 pt
->vars_contains_nonlocal
= vars_contains_nonlocal
;
6258 pt
->vars_contains_escaped
6259 = (cfun
->gimple_df
->escaped
.anything
6260 || bitmap_intersect_p (cfun
->gimple_df
->escaped
.vars
, vars
));
6263 /* Set the points-to solution *PT to point only to the variable VAR. */
6266 pt_solution_set_var (struct pt_solution
*pt
, tree var
)
6268 memset (pt
, 0, sizeof (struct pt_solution
));
6269 pt
->vars
= BITMAP_GGC_ALLOC ();
6270 bitmap_set_bit (pt
->vars
, DECL_PT_UID (var
));
6271 pt
->vars_contains_nonlocal
= is_global_var (var
);
6272 pt
->vars_contains_escaped
6273 = (cfun
->gimple_df
->escaped
.anything
6274 || bitmap_bit_p (cfun
->gimple_df
->escaped
.vars
, DECL_PT_UID (var
)));
6277 /* Computes the union of the points-to solutions *DEST and *SRC and
6278 stores the result in *DEST. This changes the points-to bitmap
6279 of *DEST and thus may not be used if that might be shared.
6280 The points-to bitmap of *SRC and *DEST will not be shared after
6281 this function if they were not before. */
6284 pt_solution_ior_into (struct pt_solution
*dest
, struct pt_solution
*src
)
6286 dest
->anything
|= src
->anything
;
6289 pt_solution_reset (dest
);
6293 dest
->nonlocal
|= src
->nonlocal
;
6294 dest
->escaped
|= src
->escaped
;
6295 dest
->ipa_escaped
|= src
->ipa_escaped
;
6296 dest
->null
|= src
->null
;
6297 dest
->vars_contains_nonlocal
|= src
->vars_contains_nonlocal
;
6298 dest
->vars_contains_escaped
|= src
->vars_contains_escaped
;
6299 dest
->vars_contains_escaped_heap
|= src
->vars_contains_escaped_heap
;
6304 dest
->vars
= BITMAP_GGC_ALLOC ();
6305 bitmap_ior_into (dest
->vars
, src
->vars
);
6308 /* Return true if the points-to solution *PT is empty. */
6311 pt_solution_empty_p (struct pt_solution
*pt
)
6318 && !bitmap_empty_p (pt
->vars
))
6321 /* If the solution includes ESCAPED, check if that is empty. */
6323 && !pt_solution_empty_p (&cfun
->gimple_df
->escaped
))
6326 /* If the solution includes ESCAPED, check if that is empty. */
6328 && !pt_solution_empty_p (&ipa_escaped_pt
))
6334 /* Return true if the points-to solution *PT only point to a single var, and
6335 return the var uid in *UID. */
6338 pt_solution_singleton_p (struct pt_solution
*pt
, unsigned *uid
)
6340 if (pt
->anything
|| pt
->nonlocal
|| pt
->escaped
|| pt
->ipa_escaped
6341 || pt
->null
|| pt
->vars
== NULL
6342 || !bitmap_single_bit_set_p (pt
->vars
))
6345 *uid
= bitmap_first_set_bit (pt
->vars
);
6349 /* Return true if the points-to solution *PT includes global memory. */
6352 pt_solution_includes_global (struct pt_solution
*pt
)
6356 || pt
->vars_contains_nonlocal
6357 /* The following is a hack to make the malloc escape hack work.
6358 In reality we'd need different sets for escaped-through-return
6359 and escaped-to-callees and passes would need to be updated. */
6360 || pt
->vars_contains_escaped_heap
)
6363 /* 'escaped' is also a placeholder so we have to look into it. */
6365 return pt_solution_includes_global (&cfun
->gimple_df
->escaped
);
6367 if (pt
->ipa_escaped
)
6368 return pt_solution_includes_global (&ipa_escaped_pt
);
6370 /* ??? This predicate is not correct for the IPA-PTA solution
6371 as we do not properly distinguish between unit escape points
6372 and global variables. */
6373 if (cfun
->gimple_df
->ipa_pta
)
6379 /* Return true if the points-to solution *PT includes the variable
6380 declaration DECL. */
6383 pt_solution_includes_1 (struct pt_solution
*pt
, const_tree decl
)
6389 && is_global_var (decl
))
6393 && bitmap_bit_p (pt
->vars
, DECL_PT_UID (decl
)))
6396 /* If the solution includes ESCAPED, check it. */
6398 && pt_solution_includes_1 (&cfun
->gimple_df
->escaped
, decl
))
6401 /* If the solution includes ESCAPED, check it. */
6403 && pt_solution_includes_1 (&ipa_escaped_pt
, decl
))
6410 pt_solution_includes (struct pt_solution
*pt
, const_tree decl
)
6412 bool res
= pt_solution_includes_1 (pt
, decl
);
6414 ++pta_stats
.pt_solution_includes_may_alias
;
6416 ++pta_stats
.pt_solution_includes_no_alias
;
6420 /* Return true if both points-to solutions PT1 and PT2 have a non-empty
6424 pt_solutions_intersect_1 (struct pt_solution
*pt1
, struct pt_solution
*pt2
)
6426 if (pt1
->anything
|| pt2
->anything
)
6429 /* If either points to unknown global memory and the other points to
6430 any global memory they alias. */
6433 || pt2
->vars_contains_nonlocal
))
6435 && pt1
->vars_contains_nonlocal
))
6438 /* If either points to all escaped memory and the other points to
6439 any escaped memory they alias. */
6442 || pt2
->vars_contains_escaped
))
6444 && pt1
->vars_contains_escaped
))
6447 /* Check the escaped solution if required.
6448 ??? Do we need to check the local against the IPA escaped sets? */
6449 if ((pt1
->ipa_escaped
|| pt2
->ipa_escaped
)
6450 && !pt_solution_empty_p (&ipa_escaped_pt
))
6452 /* If both point to escaped memory and that solution
6453 is not empty they alias. */
6454 if (pt1
->ipa_escaped
&& pt2
->ipa_escaped
)
6457 /* If either points to escaped memory see if the escaped solution
6458 intersects with the other. */
6459 if ((pt1
->ipa_escaped
6460 && pt_solutions_intersect_1 (&ipa_escaped_pt
, pt2
))
6461 || (pt2
->ipa_escaped
6462 && pt_solutions_intersect_1 (&ipa_escaped_pt
, pt1
)))
6466 /* Now both pointers alias if their points-to solution intersects. */
6469 && bitmap_intersect_p (pt1
->vars
, pt2
->vars
));
6473 pt_solutions_intersect (struct pt_solution
*pt1
, struct pt_solution
*pt2
)
6475 bool res
= pt_solutions_intersect_1 (pt1
, pt2
);
6477 ++pta_stats
.pt_solutions_intersect_may_alias
;
6479 ++pta_stats
.pt_solutions_intersect_no_alias
;
6484 /* Dump points-to information to OUTFILE. */
6487 dump_sa_points_to_info (FILE *outfile
)
6491 fprintf (outfile
, "\nPoints-to sets\n\n");
6493 if (dump_flags
& TDF_STATS
)
6495 fprintf (outfile
, "Stats:\n");
6496 fprintf (outfile
, "Total vars: %d\n", stats
.total_vars
);
6497 fprintf (outfile
, "Non-pointer vars: %d\n",
6498 stats
.nonpointer_vars
);
6499 fprintf (outfile
, "Statically unified vars: %d\n",
6500 stats
.unified_vars_static
);
6501 fprintf (outfile
, "Dynamically unified vars: %d\n",
6502 stats
.unified_vars_dynamic
);
6503 fprintf (outfile
, "Iterations: %d\n", stats
.iterations
);
6504 fprintf (outfile
, "Number of edges: %d\n", stats
.num_edges
);
6505 fprintf (outfile
, "Number of implicit edges: %d\n",
6506 stats
.num_implicit_edges
);
6509 for (i
= 1; i
< varmap
.length (); i
++)
6511 varinfo_t vi
= get_varinfo (i
);
6512 if (!vi
->may_have_pointers
)
6514 dump_solution_for_var (outfile
, i
);
6519 /* Debug points-to information to stderr. */
6522 debug_sa_points_to_info (void)
6524 dump_sa_points_to_info (stderr
);
6528 /* Initialize the always-existing constraint variables for NULL
6529 ANYTHING, READONLY, and INTEGER */
6532 init_base_vars (void)
6534 struct constraint_expr lhs
, rhs
;
6535 varinfo_t var_anything
;
6536 varinfo_t var_nothing
;
6537 varinfo_t var_string
;
6538 varinfo_t var_escaped
;
6539 varinfo_t var_nonlocal
;
6540 varinfo_t var_storedanything
;
6541 varinfo_t var_integer
;
6543 /* Variable ID zero is reserved and should be NULL. */
6544 varmap
.safe_push (NULL
);
6546 /* Create the NULL variable, used to represent that a variable points
6548 var_nothing
= new_var_info (NULL_TREE
, "NULL", false);
6549 gcc_assert (var_nothing
->id
== nothing_id
);
6550 var_nothing
->is_artificial_var
= 1;
6551 var_nothing
->offset
= 0;
6552 var_nothing
->size
= ~0;
6553 var_nothing
->fullsize
= ~0;
6554 var_nothing
->is_special_var
= 1;
6555 var_nothing
->may_have_pointers
= 0;
6556 var_nothing
->is_global_var
= 0;
6558 /* Create the ANYTHING variable, used to represent that a variable
6559 points to some unknown piece of memory. */
6560 var_anything
= new_var_info (NULL_TREE
, "ANYTHING", false);
6561 gcc_assert (var_anything
->id
== anything_id
);
6562 var_anything
->is_artificial_var
= 1;
6563 var_anything
->size
= ~0;
6564 var_anything
->offset
= 0;
6565 var_anything
->fullsize
= ~0;
6566 var_anything
->is_special_var
= 1;
6568 /* Anything points to anything. This makes deref constraints just
6569 work in the presence of linked list and other p = *p type loops,
6570 by saying that *ANYTHING = ANYTHING. */
6572 lhs
.var
= anything_id
;
6574 rhs
.type
= ADDRESSOF
;
6575 rhs
.var
= anything_id
;
6578 /* This specifically does not use process_constraint because
6579 process_constraint ignores all anything = anything constraints, since all
6580 but this one are redundant. */
6581 constraints
.safe_push (new_constraint (lhs
, rhs
));
6583 /* Create the STRING variable, used to represent that a variable
6584 points to a string literal. String literals don't contain
6585 pointers so STRING doesn't point to anything. */
6586 var_string
= new_var_info (NULL_TREE
, "STRING", false);
6587 gcc_assert (var_string
->id
== string_id
);
6588 var_string
->is_artificial_var
= 1;
6589 var_string
->offset
= 0;
6590 var_string
->size
= ~0;
6591 var_string
->fullsize
= ~0;
6592 var_string
->is_special_var
= 1;
6593 var_string
->may_have_pointers
= 0;
6595 /* Create the ESCAPED variable, used to represent the set of escaped
6597 var_escaped
= new_var_info (NULL_TREE
, "ESCAPED", false);
6598 gcc_assert (var_escaped
->id
== escaped_id
);
6599 var_escaped
->is_artificial_var
= 1;
6600 var_escaped
->offset
= 0;
6601 var_escaped
->size
= ~0;
6602 var_escaped
->fullsize
= ~0;
6603 var_escaped
->is_special_var
= 0;
6605 /* Create the NONLOCAL variable, used to represent the set of nonlocal
6607 var_nonlocal
= new_var_info (NULL_TREE
, "NONLOCAL", false);
6608 gcc_assert (var_nonlocal
->id
== nonlocal_id
);
6609 var_nonlocal
->is_artificial_var
= 1;
6610 var_nonlocal
->offset
= 0;
6611 var_nonlocal
->size
= ~0;
6612 var_nonlocal
->fullsize
= ~0;
6613 var_nonlocal
->is_special_var
= 1;
6615 /* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
6617 lhs
.var
= escaped_id
;
6620 rhs
.var
= escaped_id
;
6622 process_constraint (new_constraint (lhs
, rhs
));
6624 /* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
6625 whole variable escapes. */
6627 lhs
.var
= escaped_id
;
6630 rhs
.var
= escaped_id
;
6631 rhs
.offset
= UNKNOWN_OFFSET
;
6632 process_constraint (new_constraint (lhs
, rhs
));
6634 /* *ESCAPED = NONLOCAL. This is true because we have to assume
6635 everything pointed to by escaped points to what global memory can
6638 lhs
.var
= escaped_id
;
6641 rhs
.var
= nonlocal_id
;
6643 process_constraint (new_constraint (lhs
, rhs
));
6645 /* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
6646 global memory may point to global memory and escaped memory. */
6648 lhs
.var
= nonlocal_id
;
6650 rhs
.type
= ADDRESSOF
;
6651 rhs
.var
= nonlocal_id
;
6653 process_constraint (new_constraint (lhs
, rhs
));
6654 rhs
.type
= ADDRESSOF
;
6655 rhs
.var
= escaped_id
;
6657 process_constraint (new_constraint (lhs
, rhs
));
6659 /* Create the STOREDANYTHING variable, used to represent the set of
6660 variables stored to *ANYTHING. */
6661 var_storedanything
= new_var_info (NULL_TREE
, "STOREDANYTHING", false);
6662 gcc_assert (var_storedanything
->id
== storedanything_id
);
6663 var_storedanything
->is_artificial_var
= 1;
6664 var_storedanything
->offset
= 0;
6665 var_storedanything
->size
= ~0;
6666 var_storedanything
->fullsize
= ~0;
6667 var_storedanything
->is_special_var
= 0;
6669 /* Create the INTEGER variable, used to represent that a variable points
6670 to what an INTEGER "points to". */
6671 var_integer
= new_var_info (NULL_TREE
, "INTEGER", false);
6672 gcc_assert (var_integer
->id
== integer_id
);
6673 var_integer
->is_artificial_var
= 1;
6674 var_integer
->size
= ~0;
6675 var_integer
->fullsize
= ~0;
6676 var_integer
->offset
= 0;
6677 var_integer
->is_special_var
= 1;
6679 /* INTEGER = ANYTHING, because we don't know where a dereference of
6680 a random integer will point to. */
6682 lhs
.var
= integer_id
;
6684 rhs
.type
= ADDRESSOF
;
6685 rhs
.var
= anything_id
;
6687 process_constraint (new_constraint (lhs
, rhs
));
6690 /* Initialize things necessary to perform PTA */
6693 init_alias_vars (void)
6695 use_field_sensitive
= (MAX_FIELDS_FOR_FIELD_SENSITIVE
> 1);
6697 bitmap_obstack_initialize (&pta_obstack
);
6698 bitmap_obstack_initialize (&oldpta_obstack
);
6699 bitmap_obstack_initialize (&predbitmap_obstack
);
6701 constraints
.create (8);
6703 vi_for_tree
= new hash_map
<tree
, varinfo_t
>;
6704 call_stmt_vars
= new hash_map
<gimple
*, varinfo_t
>;
6706 memset (&stats
, 0, sizeof (stats
));
6707 shared_bitmap_table
= new hash_table
<shared_bitmap_hasher
> (511);
6710 gcc_obstack_init (&fake_var_decl_obstack
);
6712 final_solutions
= new hash_map
<varinfo_t
, pt_solution
*>;
6713 gcc_obstack_init (&final_solutions_obstack
);
6716 /* Remove the REF and ADDRESS edges from GRAPH, as well as all the
6717 predecessor edges. */
6720 remove_preds_and_fake_succs (constraint_graph_t graph
)
6724 /* Clear the implicit ref and address nodes from the successor
6726 for (i
= 1; i
< FIRST_REF_NODE
; i
++)
6728 if (graph
->succs
[i
])
6729 bitmap_clear_range (graph
->succs
[i
], FIRST_REF_NODE
,
6730 FIRST_REF_NODE
* 2);
6733 /* Free the successor list for the non-ref nodes. */
6734 for (i
= FIRST_REF_NODE
+ 1; i
< graph
->size
; i
++)
6736 if (graph
->succs
[i
])
6737 BITMAP_FREE (graph
->succs
[i
]);
6740 /* Now reallocate the size of the successor list as, and blow away
6741 the predecessor bitmaps. */
6742 graph
->size
= varmap
.length ();
6743 graph
->succs
= XRESIZEVEC (bitmap
, graph
->succs
, graph
->size
);
6745 free (graph
->implicit_preds
);
6746 graph
->implicit_preds
= NULL
;
6747 free (graph
->preds
);
6748 graph
->preds
= NULL
;
6749 bitmap_obstack_release (&predbitmap_obstack
);
6752 /* Solve the constraint set. */
6755 solve_constraints (void)
6757 struct scc_info
*si
;
6761 "\nCollapsing static cycles and doing variable "
6764 init_graph (varmap
.length () * 2);
6767 fprintf (dump_file
, "Building predecessor graph\n");
6768 build_pred_graph ();
6771 fprintf (dump_file
, "Detecting pointer and location "
6773 si
= perform_var_substitution (graph
);
6776 fprintf (dump_file
, "Rewriting constraints and unifying "
6778 rewrite_constraints (graph
, si
);
6780 build_succ_graph ();
6782 free_var_substitution_info (si
);
6784 /* Attach complex constraints to graph nodes. */
6785 move_complex_constraints (graph
);
6788 fprintf (dump_file
, "Uniting pointer but not location equivalent "
6790 unite_pointer_equivalences (graph
);
6793 fprintf (dump_file
, "Finding indirect cycles\n");
6794 find_indirect_cycles (graph
);
6796 /* Implicit nodes and predecessors are no longer necessary at this
6798 remove_preds_and_fake_succs (graph
);
6800 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
6802 fprintf (dump_file
, "\n\n// The constraint graph before solve-graph "
6803 "in dot format:\n");
6804 dump_constraint_graph (dump_file
);
6805 fprintf (dump_file
, "\n\n");
6809 fprintf (dump_file
, "Solving graph\n");
6811 solve_graph (graph
);
6813 if (dump_file
&& (dump_flags
& TDF_GRAPH
))
6815 fprintf (dump_file
, "\n\n// The constraint graph after solve-graph "
6816 "in dot format:\n");
6817 dump_constraint_graph (dump_file
);
6818 fprintf (dump_file
, "\n\n");
6822 dump_sa_points_to_info (dump_file
);
6825 /* Create points-to sets for the current function. See the comments
6826 at the start of the file for an algorithmic overview. */
6829 compute_points_to_sets (void)
6835 timevar_push (TV_TREE_PTA
);
6839 intra_create_variable_infos (cfun
);
6841 /* Now walk all statements and build the constraint set. */
6842 FOR_EACH_BB_FN (bb
, cfun
)
6844 for (gphi_iterator gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
6847 gphi
*phi
= gsi
.phi ();
6849 if (! virtual_operand_p (gimple_phi_result (phi
)))
6850 find_func_aliases (cfun
, phi
);
6853 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
);
6856 gimple
*stmt
= gsi_stmt (gsi
);
6858 find_func_aliases (cfun
, stmt
);
6864 fprintf (dump_file
, "Points-to analysis\n\nConstraints:\n\n");
6865 dump_constraints (dump_file
, 0);
6868 /* From the constraints compute the points-to sets. */
6869 solve_constraints ();
6871 /* Compute the points-to set for ESCAPED used for call-clobber analysis. */
6872 cfun
->gimple_df
->escaped
= find_what_var_points_to (get_varinfo (escaped_id
));
6874 /* Make sure the ESCAPED solution (which is used as placeholder in
6875 other solutions) does not reference itself. This simplifies
6876 points-to solution queries. */
6877 cfun
->gimple_df
->escaped
.escaped
= 0;
6879 /* Compute the points-to sets for pointer SSA_NAMEs. */
6880 for (i
= 0; i
< num_ssa_names
; ++i
)
6882 tree ptr
= ssa_name (i
);
6884 && POINTER_TYPE_P (TREE_TYPE (ptr
)))
6885 find_what_p_points_to (ptr
);
6888 /* Compute the call-used/clobbered sets. */
6889 FOR_EACH_BB_FN (bb
, cfun
)
6891 gimple_stmt_iterator gsi
;
6893 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
6896 struct pt_solution
*pt
;
6898 stmt
= dyn_cast
<gcall
*> (gsi_stmt (gsi
));
6902 pt
= gimple_call_use_set (stmt
);
6903 if (gimple_call_flags (stmt
) & ECF_CONST
)
6904 memset (pt
, 0, sizeof (struct pt_solution
));
6905 else if ((vi
= lookup_call_use_vi (stmt
)) != NULL
)
6907 *pt
= find_what_var_points_to (vi
);
6908 /* Escaped (and thus nonlocal) variables are always
6909 implicitly used by calls. */
6910 /* ??? ESCAPED can be empty even though NONLOCAL
6917 /* If there is nothing special about this call then
6918 we have made everything that is used also escape. */
6919 *pt
= cfun
->gimple_df
->escaped
;
6923 pt
= gimple_call_clobber_set (stmt
);
6924 if (gimple_call_flags (stmt
) & (ECF_CONST
|ECF_PURE
|ECF_NOVOPS
))
6925 memset (pt
, 0, sizeof (struct pt_solution
));
6926 else if ((vi
= lookup_call_clobber_vi (stmt
)) != NULL
)
6928 *pt
= find_what_var_points_to (vi
);
6929 /* Escaped (and thus nonlocal) variables are always
6930 implicitly clobbered by calls. */
6931 /* ??? ESCAPED can be empty even though NONLOCAL
6938 /* If there is nothing special about this call then
6939 we have made everything that is used also escape. */
6940 *pt
= cfun
->gimple_df
->escaped
;
6946 timevar_pop (TV_TREE_PTA
);
6950 /* Delete created points-to sets. */
6953 delete_points_to_sets (void)
6957 delete shared_bitmap_table
;
6958 shared_bitmap_table
= NULL
;
6959 if (dump_file
&& (dump_flags
& TDF_STATS
))
6960 fprintf (dump_file
, "Points to sets created:%d\n",
6961 stats
.points_to_sets_created
);
6964 delete call_stmt_vars
;
6965 bitmap_obstack_release (&pta_obstack
);
6966 constraints
.release ();
6968 for (i
= 0; i
< graph
->size
; i
++)
6969 graph
->complex[i
].release ();
6970 free (graph
->complex);
6973 free (graph
->succs
);
6975 free (graph
->pe_rep
);
6976 free (graph
->indirect_cycles
);
6980 variable_info_pool
.release ();
6981 constraint_pool
.release ();
6983 obstack_free (&fake_var_decl_obstack
, NULL
);
6985 delete final_solutions
;
6986 obstack_free (&final_solutions_obstack
, NULL
);
6989 /* Mark "other" loads and stores as belonging to CLIQUE and with
6993 visit_loadstore (gimple
*, tree base
, tree ref
, void *clique_
)
6995 unsigned short clique
= (uintptr_t)clique_
;
6996 if (TREE_CODE (base
) == MEM_REF
6997 || TREE_CODE (base
) == TARGET_MEM_REF
)
6999 tree ptr
= TREE_OPERAND (base
, 0);
7000 if (TREE_CODE (ptr
) == SSA_NAME
7001 && ! SSA_NAME_IS_DEFAULT_DEF (ptr
))
7003 /* ??? We need to make sure 'ptr' doesn't include any of
7004 the restrict tags we added bases for in its points-to set. */
7008 /* For now let decls through. */
7010 /* Do not overwrite existing cliques (that includes clique, base
7011 pairs we just set). */
7012 if (MR_DEPENDENCE_CLIQUE (base
) == 0)
7014 MR_DEPENDENCE_CLIQUE (base
) = clique
;
7015 MR_DEPENDENCE_BASE (base
) = 0;
7019 /* For plain decl accesses see whether they are accesses to globals
7020 and rewrite them to MEM_REFs with { clique, 0 }. */
7021 if (TREE_CODE (base
) == VAR_DECL
7022 && is_global_var (base
)
7023 /* ??? We can't rewrite a plain decl with the walk_stmt_load_store
7028 while (handled_component_p (*basep
))
7029 basep
= &TREE_OPERAND (*basep
, 0);
7030 gcc_assert (TREE_CODE (*basep
) == VAR_DECL
);
7031 tree ptr
= build_fold_addr_expr (*basep
);
7032 tree zero
= build_int_cst (TREE_TYPE (ptr
), 0);
7033 *basep
= build2 (MEM_REF
, TREE_TYPE (*basep
), ptr
, zero
);
7034 MR_DEPENDENCE_CLIQUE (*basep
) = clique
;
7035 MR_DEPENDENCE_BASE (*basep
) = 0;
7041 /* If REF is a MEM_REF then assign a clique, base pair to it, updating
7042 CLIQUE, *RESTRICT_VAR and LAST_RUID. Return whether dependence info
7043 was assigned to REF. */
7046 maybe_set_dependence_info (tree ref
, tree ptr
,
7047 unsigned short &clique
, varinfo_t restrict_var
,
7048 unsigned short &last_ruid
)
7050 while (handled_component_p (ref
))
7051 ref
= TREE_OPERAND (ref
, 0);
7052 if ((TREE_CODE (ref
) == MEM_REF
7053 || TREE_CODE (ref
) == TARGET_MEM_REF
)
7054 && TREE_OPERAND (ref
, 0) == ptr
)
7056 /* Do not overwrite existing cliques. This avoids overwriting dependence
7057 info inlined from a function with restrict parameters inlined
7058 into a function with restrict parameters. This usually means we
7059 prefer to be precise in innermost loops. */
7060 if (MR_DEPENDENCE_CLIQUE (ref
) == 0)
7063 clique
= ++cfun
->last_clique
;
7064 if (restrict_var
->ruid
== 0)
7065 restrict_var
->ruid
= ++last_ruid
;
7066 MR_DEPENDENCE_CLIQUE (ref
) = clique
;
7067 MR_DEPENDENCE_BASE (ref
) = restrict_var
->ruid
;
7074 /* Compute the set of independend memory references based on restrict
7075 tags and their conservative propagation to the points-to sets. */
7078 compute_dependence_clique (void)
7080 unsigned short clique
= 0;
7081 unsigned short last_ruid
= 0;
7082 for (unsigned i
= 0; i
< num_ssa_names
; ++i
)
7084 tree ptr
= ssa_name (i
);
7085 if (!ptr
|| !POINTER_TYPE_P (TREE_TYPE (ptr
)))
7088 /* Avoid all this when ptr is not dereferenced? */
7090 if (SSA_NAME_IS_DEFAULT_DEF (ptr
)
7091 && (TREE_CODE (SSA_NAME_VAR (ptr
)) == PARM_DECL
7092 || TREE_CODE (SSA_NAME_VAR (ptr
)) == RESULT_DECL
))
7093 p
= SSA_NAME_VAR (ptr
);
7094 varinfo_t vi
= lookup_vi_for_tree (p
);
7097 vi
= get_varinfo (find (vi
->id
));
7100 varinfo_t restrict_var
= NULL
;
7101 EXECUTE_IF_SET_IN_BITMAP (vi
->solution
, 0, j
, bi
)
7103 varinfo_t oi
= get_varinfo (j
);
7104 if (oi
->is_restrict_var
)
7108 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7110 fprintf (dump_file
, "found restrict pointed-to "
7112 print_generic_expr (dump_file
, ptr
, 0);
7113 fprintf (dump_file
, " but not exclusively\n");
7115 restrict_var
= NULL
;
7120 /* NULL is the only other valid points-to entry. */
7121 else if (oi
->id
!= nothing_id
)
7123 restrict_var
= NULL
;
7127 /* Ok, found that ptr must(!) point to a single(!) restrict
7129 /* ??? PTA isn't really a proper propagation engine to compute
7131 ??? We could handle merging of two restricts by unifying them. */
7134 /* Now look at possible dereferences of ptr. */
7135 imm_use_iterator ui
;
7137 FOR_EACH_IMM_USE_STMT (use_stmt
, ui
, ptr
)
7139 /* ??? Calls and asms. */
7140 if (!gimple_assign_single_p (use_stmt
))
7142 maybe_set_dependence_info (gimple_assign_lhs (use_stmt
), ptr
,
7143 clique
, restrict_var
, last_ruid
);
7144 maybe_set_dependence_info (gimple_assign_rhs1 (use_stmt
), ptr
,
7145 clique
, restrict_var
, last_ruid
);
7153 /* Assign the BASE id zero to all accesses not based on a restrict
7154 pointer. That way they get disabiguated against restrict
7155 accesses but not against each other. */
7156 /* ??? For restricts derived from globals (thus not incoming
7157 parameters) we can't restrict scoping properly thus the following
7158 is too aggressive there. For now we have excluded those globals from
7159 getting into the MR_DEPENDENCE machinery. */
7161 FOR_EACH_BB_FN (bb
, cfun
)
7162 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
);
7163 !gsi_end_p (gsi
); gsi_next (&gsi
))
7165 gimple
*stmt
= gsi_stmt (gsi
);
7166 walk_stmt_load_store_ops (stmt
, (void *)(uintptr_t)clique
,
7167 visit_loadstore
, visit_loadstore
);
7171 /* Compute points-to information for every SSA_NAME pointer in the
7172 current function and compute the transitive closure of escaped
7173 variables to re-initialize the call-clobber states of local variables. */
7176 compute_may_aliases (void)
7178 if (cfun
->gimple_df
->ipa_pta
)
7182 fprintf (dump_file
, "\nNot re-computing points-to information "
7183 "because IPA points-to information is available.\n\n");
7185 /* But still dump what we have remaining it. */
7186 dump_alias_info (dump_file
);
7192 /* For each pointer P_i, determine the sets of variables that P_i may
7193 point-to. Compute the reachability set of escaped and call-used
7195 compute_points_to_sets ();
7197 /* Debugging dumps. */
7199 dump_alias_info (dump_file
);
7201 /* Compute restrict-based memory disambiguations. */
7202 compute_dependence_clique ();
7204 /* Deallocate memory used by aliasing data structures and the internal
7205 points-to solution. */
7206 delete_points_to_sets ();
7208 gcc_assert (!need_ssa_update_p (cfun
));
7213 /* A dummy pass to cause points-to information to be computed via
7214 TODO_rebuild_alias. */
7218 const pass_data pass_data_build_alias
=
7220 GIMPLE_PASS
, /* type */
7222 OPTGROUP_NONE
, /* optinfo_flags */
7223 TV_NONE
, /* tv_id */
7224 ( PROP_cfg
| PROP_ssa
), /* properties_required */
7225 0, /* properties_provided */
7226 0, /* properties_destroyed */
7227 0, /* todo_flags_start */
7228 TODO_rebuild_alias
, /* todo_flags_finish */
7231 class pass_build_alias
: public gimple_opt_pass
7234 pass_build_alias (gcc::context
*ctxt
)
7235 : gimple_opt_pass (pass_data_build_alias
, ctxt
)
7238 /* opt_pass methods: */
7239 virtual bool gate (function
*) { return flag_tree_pta
; }
7241 }; // class pass_build_alias
7246 make_pass_build_alias (gcc::context
*ctxt
)
7248 return new pass_build_alias (ctxt
);
7251 /* A dummy pass to cause points-to information to be computed via
7252 TODO_rebuild_alias. */
7256 const pass_data pass_data_build_ealias
=
7258 GIMPLE_PASS
, /* type */
7259 "ealias", /* name */
7260 OPTGROUP_NONE
, /* optinfo_flags */
7261 TV_NONE
, /* tv_id */
7262 ( PROP_cfg
| PROP_ssa
), /* properties_required */
7263 0, /* properties_provided */
7264 0, /* properties_destroyed */
7265 0, /* todo_flags_start */
7266 TODO_rebuild_alias
, /* todo_flags_finish */
7269 class pass_build_ealias
: public gimple_opt_pass
7272 pass_build_ealias (gcc::context
*ctxt
)
7273 : gimple_opt_pass (pass_data_build_ealias
, ctxt
)
7276 /* opt_pass methods: */
7277 virtual bool gate (function
*) { return flag_tree_pta
; }
7279 }; // class pass_build_ealias
7284 make_pass_build_ealias (gcc::context
*ctxt
)
7286 return new pass_build_ealias (ctxt
);
7290 /* IPA PTA solutions for ESCAPED. */
7291 struct pt_solution ipa_escaped_pt
7292 = { true, false, false, false, false, false, false, false, NULL
};
7294 /* Associate node with varinfo DATA. Worker for
7295 cgraph_for_node_and_aliases. */
7297 associate_varinfo_to_alias (struct cgraph_node
*node
, void *data
)
7299 if ((node
->alias
|| node
->thunk
.thunk_p
)
7301 insert_vi_for_tree (node
->decl
, (varinfo_t
)data
);
7305 /* Execute the driver for IPA PTA. */
7307 ipa_pta_execute (void)
7309 struct cgraph_node
*node
;
7311 unsigned int from
= 0;
7317 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
7319 symtab_node::dump_table (dump_file
);
7320 fprintf (dump_file
, "\n");
7325 fprintf (dump_file
, "Generating generic constraints\n\n");
7326 dump_constraints (dump_file
, from
);
7327 fprintf (dump_file
, "\n");
7328 from
= constraints
.length ();
7331 /* Build the constraints. */
7332 FOR_EACH_DEFINED_FUNCTION (node
)
7335 /* Nodes without a body are not interesting. Especially do not
7336 visit clones at this point for now - we get duplicate decls
7337 there for inline clones at least. */
7338 if (!node
->has_gimple_body_p () || node
->global
.inlined_to
)
7342 gcc_assert (!node
->clone_of
);
7344 /* For externally visible or attribute used annotated functions use
7345 local constraints for their arguments.
7346 For local functions we see all callers and thus do not need initial
7347 constraints for parameters. */
7348 bool nonlocal_p
= (node
->used_from_other_partition
7349 || node
->externally_visible
7350 || node
->force_output
7351 || node
->address_taken
);
7353 vi
= create_function_info_for (node
->decl
,
7354 alias_get_name (node
->decl
), false,
7357 && from
!= constraints
.length ())
7360 "Generating intial constraints for %s", node
->name ());
7361 if (DECL_ASSEMBLER_NAME_SET_P (node
->decl
))
7362 fprintf (dump_file
, " (%s)",
7364 (DECL_ASSEMBLER_NAME (node
->decl
)));
7365 fprintf (dump_file
, "\n\n");
7366 dump_constraints (dump_file
, from
);
7367 fprintf (dump_file
, "\n");
7369 from
= constraints
.length ();
7372 node
->call_for_symbol_thunks_and_aliases
7373 (associate_varinfo_to_alias
, vi
, true);
7376 /* Create constraints for global variables and their initializers. */
7377 FOR_EACH_VARIABLE (var
)
7379 if (var
->alias
&& var
->analyzed
)
7382 get_vi_for_tree (var
->decl
);
7386 && from
!= constraints
.length ())
7389 "Generating constraints for global initializers\n\n");
7390 dump_constraints (dump_file
, from
);
7391 fprintf (dump_file
, "\n");
7392 from
= constraints
.length ();
7395 FOR_EACH_DEFINED_FUNCTION (node
)
7397 struct function
*func
;
7400 /* Nodes without a body are not interesting. */
7401 if (!node
->has_gimple_body_p () || node
->clone_of
)
7407 "Generating constraints for %s", node
->name ());
7408 if (DECL_ASSEMBLER_NAME_SET_P (node
->decl
))
7409 fprintf (dump_file
, " (%s)",
7411 (DECL_ASSEMBLER_NAME (node
->decl
)));
7412 fprintf (dump_file
, "\n");
7415 func
= DECL_STRUCT_FUNCTION (node
->decl
);
7416 gcc_assert (cfun
== NULL
);
7418 /* Build constriants for the function body. */
7419 FOR_EACH_BB_FN (bb
, func
)
7421 for (gphi_iterator gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
7424 gphi
*phi
= gsi
.phi ();
7426 if (! virtual_operand_p (gimple_phi_result (phi
)))
7427 find_func_aliases (func
, phi
);
7430 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
);
7433 gimple
*stmt
= gsi_stmt (gsi
);
7435 find_func_aliases (func
, stmt
);
7436 find_func_clobbers (func
, stmt
);
7442 fprintf (dump_file
, "\n");
7443 dump_constraints (dump_file
, from
);
7444 fprintf (dump_file
, "\n");
7445 from
= constraints
.length ();
7449 /* From the constraints compute the points-to sets. */
7450 solve_constraints ();
7452 /* Compute the global points-to sets for ESCAPED.
7453 ??? Note that the computed escape set is not correct
7454 for the whole unit as we fail to consider graph edges to
7455 externally visible functions. */
7456 ipa_escaped_pt
= find_what_var_points_to (get_varinfo (escaped_id
));
7458 /* Make sure the ESCAPED solution (which is used as placeholder in
7459 other solutions) does not reference itself. This simplifies
7460 points-to solution queries. */
7461 ipa_escaped_pt
.ipa_escaped
= 0;
7463 /* Assign the points-to sets to the SSA names in the unit. */
7464 FOR_EACH_DEFINED_FUNCTION (node
)
7467 struct function
*fn
;
7471 /* Nodes without a body are not interesting. */
7472 if (!node
->has_gimple_body_p () || node
->clone_of
)
7475 fn
= DECL_STRUCT_FUNCTION (node
->decl
);
7477 /* Compute the points-to sets for pointer SSA_NAMEs. */
7478 FOR_EACH_VEC_ELT (*fn
->gimple_df
->ssa_names
, i
, ptr
)
7481 && POINTER_TYPE_P (TREE_TYPE (ptr
)))
7482 find_what_p_points_to (ptr
);
7485 /* Compute the call-use and call-clobber sets for indirect calls
7486 and calls to external functions. */
7487 FOR_EACH_BB_FN (bb
, fn
)
7489 gimple_stmt_iterator gsi
;
7491 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
7494 struct pt_solution
*pt
;
7498 stmt
= dyn_cast
<gcall
*> (gsi_stmt (gsi
));
7502 /* Handle direct calls to functions with body. */
7503 decl
= gimple_call_fndecl (stmt
);
7505 && (fi
= lookup_vi_for_tree (decl
))
7508 *gimple_call_clobber_set (stmt
)
7509 = find_what_var_points_to
7510 (first_vi_for_offset (fi
, fi_clobbers
));
7511 *gimple_call_use_set (stmt
)
7512 = find_what_var_points_to
7513 (first_vi_for_offset (fi
, fi_uses
));
7515 /* Handle direct calls to external functions. */
7518 pt
= gimple_call_use_set (stmt
);
7519 if (gimple_call_flags (stmt
) & ECF_CONST
)
7520 memset (pt
, 0, sizeof (struct pt_solution
));
7521 else if ((vi
= lookup_call_use_vi (stmt
)) != NULL
)
7523 *pt
= find_what_var_points_to (vi
);
7524 /* Escaped (and thus nonlocal) variables are always
7525 implicitly used by calls. */
7526 /* ??? ESCAPED can be empty even though NONLOCAL
7529 pt
->ipa_escaped
= 1;
7533 /* If there is nothing special about this call then
7534 we have made everything that is used also escape. */
7535 *pt
= ipa_escaped_pt
;
7539 pt
= gimple_call_clobber_set (stmt
);
7540 if (gimple_call_flags (stmt
) & (ECF_CONST
|ECF_PURE
|ECF_NOVOPS
))
7541 memset (pt
, 0, sizeof (struct pt_solution
));
7542 else if ((vi
= lookup_call_clobber_vi (stmt
)) != NULL
)
7544 *pt
= find_what_var_points_to (vi
);
7545 /* Escaped (and thus nonlocal) variables are always
7546 implicitly clobbered by calls. */
7547 /* ??? ESCAPED can be empty even though NONLOCAL
7550 pt
->ipa_escaped
= 1;
7554 /* If there is nothing special about this call then
7555 we have made everything that is used also escape. */
7556 *pt
= ipa_escaped_pt
;
7560 /* Handle indirect calls. */
7562 && (fi
= get_fi_for_callee (stmt
)))
7564 /* We need to accumulate all clobbers/uses of all possible
7566 fi
= get_varinfo (find (fi
->id
));
7567 /* If we cannot constrain the set of functions we'll end up
7568 calling we end up using/clobbering everything. */
7569 if (bitmap_bit_p (fi
->solution
, anything_id
)
7570 || bitmap_bit_p (fi
->solution
, nonlocal_id
)
7571 || bitmap_bit_p (fi
->solution
, escaped_id
))
7573 pt_solution_reset (gimple_call_clobber_set (stmt
));
7574 pt_solution_reset (gimple_call_use_set (stmt
));
7580 struct pt_solution
*uses
, *clobbers
;
7582 uses
= gimple_call_use_set (stmt
);
7583 clobbers
= gimple_call_clobber_set (stmt
);
7584 memset (uses
, 0, sizeof (struct pt_solution
));
7585 memset (clobbers
, 0, sizeof (struct pt_solution
));
7586 EXECUTE_IF_SET_IN_BITMAP (fi
->solution
, 0, i
, bi
)
7588 struct pt_solution sol
;
7590 vi
= get_varinfo (i
);
7591 if (!vi
->is_fn_info
)
7593 /* ??? We could be more precise here? */
7595 uses
->ipa_escaped
= 1;
7596 clobbers
->nonlocal
= 1;
7597 clobbers
->ipa_escaped
= 1;
7601 if (!uses
->anything
)
7603 sol
= find_what_var_points_to
7604 (first_vi_for_offset (vi
, fi_uses
));
7605 pt_solution_ior_into (uses
, &sol
);
7607 if (!clobbers
->anything
)
7609 sol
= find_what_var_points_to
7610 (first_vi_for_offset (vi
, fi_clobbers
));
7611 pt_solution_ior_into (clobbers
, &sol
);
7619 fn
->gimple_df
->ipa_pta
= true;
7622 delete_points_to_sets ();
7631 const pass_data pass_data_ipa_pta
=
7633 SIMPLE_IPA_PASS
, /* type */
7635 OPTGROUP_NONE
, /* optinfo_flags */
7636 TV_IPA_PTA
, /* tv_id */
7637 0, /* properties_required */
7638 0, /* properties_provided */
7639 0, /* properties_destroyed */
7640 0, /* todo_flags_start */
7641 0, /* todo_flags_finish */
7644 class pass_ipa_pta
: public simple_ipa_opt_pass
7647 pass_ipa_pta (gcc::context
*ctxt
)
7648 : simple_ipa_opt_pass (pass_data_ipa_pta
, ctxt
)
7651 /* opt_pass methods: */
7652 virtual bool gate (function
*)
7656 /* Don't bother doing anything if the program has errors. */
7660 virtual unsigned int execute (function
*) { return ipa_pta_execute (); }
7662 }; // class pass_ipa_pta
7666 simple_ipa_opt_pass
*
7667 make_pass_ipa_pta (gcc::context
*ctxt
)
7669 return new pass_ipa_pta (ctxt
);