d355361573
2011-10-18 Richard Guenther <rguenther@suse.de> * tree-ssa-alias.h (struct pt_solution): Remove vars_contains_restrict member. (pt_solutions_same_restrict_base): Remove. (pt_solution_set): Adjust. * tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Remove vars_contains_restrict handling. (dump_points_to_solution): Likewise. (ptr_derefs_may_alias_p): Do not call pt_solutions_same_restrict_base. * tree-ssa-structalias.c (struct variable_info): Remove is_restrict_var field. (new_var_info): Do not initialize it. (ipa_escaped_pt): Adjust. (make_constraint_from_restrict): Make the tag global. (make_constraint_from_global_restrict): New function. (make_constraint_from_heapvar): Remove. (create_variable_info_for): Do not make restrict vars point to NONLOCAL. (intra_create_variable_infos): Likewise. (find_what_var_points_to): Remove vars_contains_restrict handling. (pt_solution_set): Adjust. (pt_solution_ior_into): Likewise. (pt_solutions_same_restrict_base): Remove. (compute_points_to_sets): Do not test is_restrict_var. * cfgexpand.c (update_alias_info_with_stack_vars): Adjust. * gimple-pretty-print.c (pp_points_to_solution): Likewise. * gcc.dg/torture/restrict-1.c: New testcase. From-SVN: r180127
7135 lines
197 KiB
C
7135 lines
197 KiB
C
/* Tree based points-to analysis
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Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
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Free Software Foundation, Inc.
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Contributed by Daniel Berlin <dberlin@dberlin.org>
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "ggc.h"
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#include "obstack.h"
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#include "bitmap.h"
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#include "flags.h"
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#include "basic-block.h"
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#include "output.h"
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#include "tree.h"
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#include "tree-flow.h"
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#include "tree-inline.h"
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#include "diagnostic-core.h"
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#include "gimple.h"
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#include "hashtab.h"
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#include "function.h"
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#include "cgraph.h"
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#include "tree-pass.h"
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#include "timevar.h"
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#include "alloc-pool.h"
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#include "splay-tree.h"
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#include "params.h"
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#include "cgraph.h"
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#include "alias.h"
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#include "pointer-set.h"
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/* The idea behind this analyzer is to generate set constraints from the
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program, then solve the resulting constraints in order to generate the
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points-to sets.
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Set constraints are a way of modeling program analysis problems that
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involve sets. They consist of an inclusion constraint language,
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describing the variables (each variable is a set) and operations that
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are involved on the variables, and a set of rules that derive facts
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from these operations. To solve a system of set constraints, you derive
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all possible facts under the rules, which gives you the correct sets
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as a consequence.
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See "Efficient Field-sensitive pointer analysis for C" by "David
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J. Pearce and Paul H. J. Kelly and Chris Hankin, at
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http://citeseer.ist.psu.edu/pearce04efficient.html
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Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
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of C Code in a Second" by ""Nevin Heintze and Olivier Tardieu" at
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http://citeseer.ist.psu.edu/heintze01ultrafast.html
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There are three types of real constraint expressions, DEREF,
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ADDRESSOF, and SCALAR. Each constraint expression consists
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of a constraint type, a variable, and an offset.
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SCALAR is a constraint expression type used to represent x, whether
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it appears on the LHS or the RHS of a statement.
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DEREF is a constraint expression type used to represent *x, whether
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it appears on the LHS or the RHS of a statement.
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ADDRESSOF is a constraint expression used to represent &x, whether
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it appears on the LHS or the RHS of a statement.
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Each pointer variable in the program is assigned an integer id, and
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each field of a structure variable is assigned an integer id as well.
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Structure variables are linked to their list of fields through a "next
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field" in each variable that points to the next field in offset
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order.
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Each variable for a structure field has
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1. "size", that tells the size in bits of that field.
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2. "fullsize, that tells the size in bits of the entire structure.
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3. "offset", that tells the offset in bits from the beginning of the
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structure to this field.
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Thus,
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struct f
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{
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int a;
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int b;
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} foo;
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int *bar;
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looks like
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foo.a -> id 1, size 32, offset 0, fullsize 64, next foo.b
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foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
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bar -> id 3, size 32, offset 0, fullsize 32, next NULL
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In order to solve the system of set constraints, the following is
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done:
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1. Each constraint variable x has a solution set associated with it,
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Sol(x).
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2. Constraints are separated into direct, copy, and complex.
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Direct constraints are ADDRESSOF constraints that require no extra
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processing, such as P = &Q
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Copy constraints are those of the form P = Q.
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Complex constraints are all the constraints involving dereferences
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and offsets (including offsetted copies).
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3. All direct constraints of the form P = &Q are processed, such
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that Q is added to Sol(P)
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4. All complex constraints for a given constraint variable are stored in a
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linked list attached to that variable's node.
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5. A directed graph is built out of the copy constraints. Each
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constraint variable is a node in the graph, and an edge from
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Q to P is added for each copy constraint of the form P = Q
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6. The graph is then walked, and solution sets are
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propagated along the copy edges, such that an edge from Q to P
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causes Sol(P) <- Sol(P) union Sol(Q).
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7. As we visit each node, all complex constraints associated with
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that node are processed by adding appropriate copy edges to the graph, or the
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appropriate variables to the solution set.
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8. The process of walking the graph is iterated until no solution
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sets change.
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Prior to walking the graph in steps 6 and 7, We perform static
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cycle elimination on the constraint graph, as well
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as off-line variable substitution.
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TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
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on and turned into anything), but isn't. You can just see what offset
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inside the pointed-to struct it's going to access.
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TODO: Constant bounded arrays can be handled as if they were structs of the
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same number of elements.
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TODO: Modeling heap and incoming pointers becomes much better if we
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add fields to them as we discover them, which we could do.
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TODO: We could handle unions, but to be honest, it's probably not
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worth the pain or slowdown. */
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/* IPA-PTA optimizations possible.
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When the indirect function called is ANYTHING we can add disambiguation
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based on the function signatures (or simply the parameter count which
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is the varinfo size). We also do not need to consider functions that
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do not have their address taken.
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The is_global_var bit which marks escape points is overly conservative
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in IPA mode. Split it to is_escape_point and is_global_var - only
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externally visible globals are escape points in IPA mode. This is
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also needed to fix the pt_solution_includes_global predicate
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(and thus ptr_deref_may_alias_global_p).
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The way we introduce DECL_PT_UID to avoid fixing up all points-to
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sets in the translation unit when we copy a DECL during inlining
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pessimizes precision. The advantage is that the DECL_PT_UID keeps
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compile-time and memory usage overhead low - the points-to sets
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do not grow or get unshared as they would during a fixup phase.
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An alternative solution is to delay IPA PTA until after all
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inlining transformations have been applied.
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The way we propagate clobber/use information isn't optimized.
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It should use a new complex constraint that properly filters
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out local variables of the callee (though that would make
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the sets invalid after inlining). OTOH we might as well
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admit defeat to WHOPR and simply do all the clobber/use analysis
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and propagation after PTA finished but before we threw away
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points-to information for memory variables. WHOPR and PTA
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do not play along well anyway - the whole constraint solving
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would need to be done in WPA phase and it will be very interesting
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to apply the results to local SSA names during LTRANS phase.
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We probably should compute a per-function unit-ESCAPE solution
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propagating it simply like the clobber / uses solutions. The
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solution can go alongside the non-IPA espaced solution and be
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used to query which vars escape the unit through a function.
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We never put function decls in points-to sets so we do not
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keep the set of called functions for indirect calls.
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And probably more. */
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static bool use_field_sensitive = true;
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static int in_ipa_mode = 0;
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/* Used for predecessor bitmaps. */
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static bitmap_obstack predbitmap_obstack;
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/* Used for points-to sets. */
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static bitmap_obstack pta_obstack;
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/* Used for oldsolution members of variables. */
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static bitmap_obstack oldpta_obstack;
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/* Used for per-solver-iteration bitmaps. */
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static bitmap_obstack iteration_obstack;
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static unsigned int create_variable_info_for (tree, const char *);
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typedef struct constraint_graph *constraint_graph_t;
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static void unify_nodes (constraint_graph_t, unsigned int, unsigned int, bool);
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struct constraint;
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typedef struct constraint *constraint_t;
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DEF_VEC_P(constraint_t);
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DEF_VEC_ALLOC_P(constraint_t,heap);
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#define EXECUTE_IF_IN_NONNULL_BITMAP(a, b, c, d) \
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if (a) \
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EXECUTE_IF_SET_IN_BITMAP (a, b, c, d)
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static struct constraint_stats
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{
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unsigned int total_vars;
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unsigned int nonpointer_vars;
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unsigned int unified_vars_static;
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unsigned int unified_vars_dynamic;
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unsigned int iterations;
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unsigned int num_edges;
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unsigned int num_implicit_edges;
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unsigned int points_to_sets_created;
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} stats;
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struct variable_info
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{
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/* ID of this variable */
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unsigned int id;
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/* True if this is a variable created by the constraint analysis, such as
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heap variables and constraints we had to break up. */
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unsigned int is_artificial_var : 1;
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/* True if this is a special variable whose solution set should not be
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changed. */
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unsigned int is_special_var : 1;
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/* True for variables whose size is not known or variable. */
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unsigned int is_unknown_size_var : 1;
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/* True for (sub-)fields that represent a whole variable. */
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unsigned int is_full_var : 1;
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/* True if this is a heap variable. */
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unsigned int is_heap_var : 1;
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/* True if this field may contain pointers. */
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unsigned int may_have_pointers : 1;
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/* True if this field has only restrict qualified pointers. */
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unsigned int only_restrict_pointers : 1;
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/* True if this represents a global variable. */
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unsigned int is_global_var : 1;
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/* True if this represents a IPA function info. */
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unsigned int is_fn_info : 1;
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/* A link to the variable for the next field in this structure. */
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struct variable_info *next;
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/* Offset of this variable, in bits, from the base variable */
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unsigned HOST_WIDE_INT offset;
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/* Size of the variable, in bits. */
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unsigned HOST_WIDE_INT size;
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/* Full size of the base variable, in bits. */
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unsigned HOST_WIDE_INT fullsize;
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/* Name of this variable */
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const char *name;
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/* Tree that this variable is associated with. */
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tree decl;
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/* Points-to set for this variable. */
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bitmap solution;
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/* Old points-to set for this variable. */
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bitmap oldsolution;
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};
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typedef struct variable_info *varinfo_t;
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static varinfo_t first_vi_for_offset (varinfo_t, unsigned HOST_WIDE_INT);
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static varinfo_t first_or_preceding_vi_for_offset (varinfo_t,
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unsigned HOST_WIDE_INT);
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static varinfo_t lookup_vi_for_tree (tree);
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/* Pool of variable info structures. */
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static alloc_pool variable_info_pool;
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DEF_VEC_P(varinfo_t);
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DEF_VEC_ALLOC_P(varinfo_t, heap);
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/* Table of variable info structures for constraint variables.
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Indexed directly by variable info id. */
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static VEC(varinfo_t,heap) *varmap;
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/* Return the varmap element N */
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static inline varinfo_t
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get_varinfo (unsigned int n)
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{
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return VEC_index (varinfo_t, varmap, n);
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}
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/* Static IDs for the special variables. */
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enum { nothing_id = 0, anything_id = 1, readonly_id = 2,
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escaped_id = 3, nonlocal_id = 4,
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storedanything_id = 5, integer_id = 6 };
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/* Return a new variable info structure consisting for a variable
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named NAME, and using constraint graph node NODE. Append it
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to the vector of variable info structures. */
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static varinfo_t
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new_var_info (tree t, const char *name)
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{
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unsigned index = VEC_length (varinfo_t, varmap);
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varinfo_t ret = (varinfo_t) pool_alloc (variable_info_pool);
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ret->id = index;
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ret->name = name;
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ret->decl = t;
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/* Vars without decl are artificial and do not have sub-variables. */
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ret->is_artificial_var = (t == NULL_TREE);
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ret->is_special_var = false;
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ret->is_unknown_size_var = false;
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ret->is_full_var = (t == NULL_TREE);
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ret->is_heap_var = false;
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ret->may_have_pointers = true;
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ret->only_restrict_pointers = false;
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ret->is_global_var = (t == NULL_TREE);
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ret->is_fn_info = false;
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if (t && DECL_P (t))
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ret->is_global_var = (is_global_var (t)
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/* We have to treat even local register variables
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as escape points. */
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|| (TREE_CODE (t) == VAR_DECL
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&& DECL_HARD_REGISTER (t)));
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ret->solution = BITMAP_ALLOC (&pta_obstack);
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ret->oldsolution = NULL;
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ret->next = NULL;
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stats.total_vars++;
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VEC_safe_push (varinfo_t, heap, varmap, ret);
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return ret;
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}
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/* A map mapping call statements to per-stmt variables for uses
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and clobbers specific to the call. */
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struct pointer_map_t *call_stmt_vars;
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/* Lookup or create the variable for the call statement CALL. */
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static varinfo_t
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get_call_vi (gimple call)
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{
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void **slot_p;
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varinfo_t vi, vi2;
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slot_p = pointer_map_insert (call_stmt_vars, call);
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if (*slot_p)
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return (varinfo_t) *slot_p;
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vi = new_var_info (NULL_TREE, "CALLUSED");
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vi->offset = 0;
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vi->size = 1;
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vi->fullsize = 2;
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vi->is_full_var = true;
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vi->next = vi2 = new_var_info (NULL_TREE, "CALLCLOBBERED");
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vi2->offset = 1;
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vi2->size = 1;
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vi2->fullsize = 2;
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vi2->is_full_var = true;
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*slot_p = (void *) vi;
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return vi;
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}
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/* Lookup the variable for the call statement CALL representing
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the uses. Returns NULL if there is nothing special about this call. */
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static varinfo_t
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lookup_call_use_vi (gimple call)
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{
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void **slot_p;
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slot_p = pointer_map_contains (call_stmt_vars, call);
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if (slot_p)
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return (varinfo_t) *slot_p;
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return NULL;
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}
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/* Lookup the variable for the call statement CALL representing
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the clobbers. Returns NULL if there is nothing special about this call. */
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static varinfo_t
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lookup_call_clobber_vi (gimple call)
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{
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varinfo_t uses = lookup_call_use_vi (call);
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if (!uses)
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return NULL;
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return uses->next;
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}
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/* Lookup or create the variable for the call statement CALL representing
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the uses. */
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static varinfo_t
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get_call_use_vi (gimple call)
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{
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return get_call_vi (call);
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}
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/* Lookup or create the variable for the call statement CALL representing
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the clobbers. */
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static varinfo_t ATTRIBUTE_UNUSED
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get_call_clobber_vi (gimple call)
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{
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return get_call_vi (call)->next;
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}
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typedef enum {SCALAR, DEREF, ADDRESSOF} constraint_expr_type;
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/* An expression that appears in a constraint. */
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struct constraint_expr
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{
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/* Constraint type. */
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constraint_expr_type type;
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/* Variable we are referring to in the constraint. */
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unsigned int var;
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/* Offset, in bits, of this constraint from the beginning of
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variables it ends up referring to.
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IOW, in a deref constraint, we would deref, get the result set,
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then add OFFSET to each member. */
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HOST_WIDE_INT offset;
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};
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/* Use 0x8000... as special unknown offset. */
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#define UNKNOWN_OFFSET ((HOST_WIDE_INT)-1 << (HOST_BITS_PER_WIDE_INT-1))
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typedef struct constraint_expr ce_s;
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DEF_VEC_O(ce_s);
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DEF_VEC_ALLOC_O(ce_s, heap);
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static void get_constraint_for_1 (tree, VEC(ce_s, heap) **, bool, bool);
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static void get_constraint_for (tree, VEC(ce_s, heap) **);
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static void get_constraint_for_rhs (tree, VEC(ce_s, heap) **);
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static void do_deref (VEC (ce_s, heap) **);
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/* Our set constraints are made up of two constraint expressions, one
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LHS, and one RHS.
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As described in the introduction, our set constraints each represent an
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operation between set valued variables.
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*/
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struct constraint
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{
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struct constraint_expr lhs;
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struct constraint_expr rhs;
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};
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/* List of constraints that we use to build the constraint graph from. */
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static VEC(constraint_t,heap) *constraints;
|
|
static alloc_pool constraint_pool;
|
|
|
|
/* The constraint graph is represented as an array of bitmaps
|
|
containing successor nodes. */
|
|
|
|
struct constraint_graph
|
|
{
|
|
/* Size of this graph, which may be different than the number of
|
|
nodes in the variable map. */
|
|
unsigned int size;
|
|
|
|
/* Explicit successors of each node. */
|
|
bitmap *succs;
|
|
|
|
/* Implicit predecessors of each node (Used for variable
|
|
substitution). */
|
|
bitmap *implicit_preds;
|
|
|
|
/* Explicit predecessors of each node (Used for variable substitution). */
|
|
bitmap *preds;
|
|
|
|
/* Indirect cycle representatives, or -1 if the node has no indirect
|
|
cycles. */
|
|
int *indirect_cycles;
|
|
|
|
/* Representative node for a node. rep[a] == a unless the node has
|
|
been unified. */
|
|
unsigned int *rep;
|
|
|
|
/* Equivalence class representative for a label. This is used for
|
|
variable substitution. */
|
|
int *eq_rep;
|
|
|
|
/* Pointer equivalence label for a node. All nodes with the same
|
|
pointer equivalence label can be unified together at some point
|
|
(either during constraint optimization or after the constraint
|
|
graph is built). */
|
|
unsigned int *pe;
|
|
|
|
/* Pointer equivalence representative for a label. This is used to
|
|
handle nodes that are pointer equivalent but not location
|
|
equivalent. We can unite these once the addressof constraints
|
|
are transformed into initial points-to sets. */
|
|
int *pe_rep;
|
|
|
|
/* Pointer equivalence label for each node, used during variable
|
|
substitution. */
|
|
unsigned int *pointer_label;
|
|
|
|
/* Location equivalence label for each node, used during location
|
|
equivalence finding. */
|
|
unsigned int *loc_label;
|
|
|
|
/* Pointed-by set for each node, used during location equivalence
|
|
finding. This is pointed-by rather than pointed-to, because it
|
|
is constructed using the predecessor graph. */
|
|
bitmap *pointed_by;
|
|
|
|
/* Points to sets for pointer equivalence. This is *not* the actual
|
|
points-to sets for nodes. */
|
|
bitmap *points_to;
|
|
|
|
/* Bitmap of nodes where the bit is set if the node is a direct
|
|
node. Used for variable substitution. */
|
|
sbitmap direct_nodes;
|
|
|
|
/* Bitmap of nodes where the bit is set if the node is address
|
|
taken. Used for variable substitution. */
|
|
bitmap address_taken;
|
|
|
|
/* Vector of complex constraints for each graph node. Complex
|
|
constraints are those involving dereferences or offsets that are
|
|
not 0. */
|
|
VEC(constraint_t,heap) **complex;
|
|
};
|
|
|
|
static constraint_graph_t graph;
|
|
|
|
/* During variable substitution and the offline version of indirect
|
|
cycle finding, we create nodes to represent dereferences and
|
|
address taken constraints. These represent where these start and
|
|
end. */
|
|
#define FIRST_REF_NODE (VEC_length (varinfo_t, varmap))
|
|
#define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
|
|
|
|
/* Return the representative node for NODE, if NODE has been unioned
|
|
with another NODE.
|
|
This function performs path compression along the way to finding
|
|
the representative. */
|
|
|
|
static unsigned int
|
|
find (unsigned int node)
|
|
{
|
|
gcc_assert (node < graph->size);
|
|
if (graph->rep[node] != node)
|
|
return graph->rep[node] = find (graph->rep[node]);
|
|
return node;
|
|
}
|
|
|
|
/* Union the TO and FROM nodes to the TO nodes.
|
|
Note that at some point in the future, we may want to do
|
|
union-by-rank, in which case we are going to have to return the
|
|
node we unified to. */
|
|
|
|
static bool
|
|
unite (unsigned int to, unsigned int from)
|
|
{
|
|
gcc_assert (to < graph->size && from < graph->size);
|
|
if (to != from && graph->rep[from] != to)
|
|
{
|
|
graph->rep[from] = to;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Create a new constraint consisting of LHS and RHS expressions. */
|
|
|
|
static constraint_t
|
|
new_constraint (const struct constraint_expr lhs,
|
|
const struct constraint_expr rhs)
|
|
{
|
|
constraint_t ret = (constraint_t) pool_alloc (constraint_pool);
|
|
ret->lhs = lhs;
|
|
ret->rhs = rhs;
|
|
return ret;
|
|
}
|
|
|
|
/* Print out constraint C to FILE. */
|
|
|
|
static void
|
|
dump_constraint (FILE *file, constraint_t c)
|
|
{
|
|
if (c->lhs.type == ADDRESSOF)
|
|
fprintf (file, "&");
|
|
else if (c->lhs.type == DEREF)
|
|
fprintf (file, "*");
|
|
fprintf (file, "%s", get_varinfo (c->lhs.var)->name);
|
|
if (c->lhs.offset == UNKNOWN_OFFSET)
|
|
fprintf (file, " + UNKNOWN");
|
|
else if (c->lhs.offset != 0)
|
|
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->lhs.offset);
|
|
fprintf (file, " = ");
|
|
if (c->rhs.type == ADDRESSOF)
|
|
fprintf (file, "&");
|
|
else if (c->rhs.type == DEREF)
|
|
fprintf (file, "*");
|
|
fprintf (file, "%s", get_varinfo (c->rhs.var)->name);
|
|
if (c->rhs.offset == UNKNOWN_OFFSET)
|
|
fprintf (file, " + UNKNOWN");
|
|
else if (c->rhs.offset != 0)
|
|
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->rhs.offset);
|
|
}
|
|
|
|
|
|
void debug_constraint (constraint_t);
|
|
void debug_constraints (void);
|
|
void debug_constraint_graph (void);
|
|
void debug_solution_for_var (unsigned int);
|
|
void debug_sa_points_to_info (void);
|
|
|
|
/* Print out constraint C to stderr. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_constraint (constraint_t c)
|
|
{
|
|
dump_constraint (stderr, c);
|
|
fprintf (stderr, "\n");
|
|
}
|
|
|
|
/* Print out all constraints to FILE */
|
|
|
|
static void
|
|
dump_constraints (FILE *file, int from)
|
|
{
|
|
int i;
|
|
constraint_t c;
|
|
for (i = from; VEC_iterate (constraint_t, constraints, i, c); i++)
|
|
if (c)
|
|
{
|
|
dump_constraint (file, c);
|
|
fprintf (file, "\n");
|
|
}
|
|
}
|
|
|
|
/* Print out all constraints to stderr. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_constraints (void)
|
|
{
|
|
dump_constraints (stderr, 0);
|
|
}
|
|
|
|
/* Print the constraint graph in dot format. */
|
|
|
|
static void
|
|
dump_constraint_graph (FILE *file)
|
|
{
|
|
unsigned int i;
|
|
|
|
/* Only print the graph if it has already been initialized: */
|
|
if (!graph)
|
|
return;
|
|
|
|
/* Prints the header of the dot file: */
|
|
fprintf (file, "strict digraph {\n");
|
|
fprintf (file, " node [\n shape = box\n ]\n");
|
|
fprintf (file, " edge [\n fontsize = \"12\"\n ]\n");
|
|
fprintf (file, "\n // List of nodes and complex constraints in "
|
|
"the constraint graph:\n");
|
|
|
|
/* The next lines print the nodes in the graph together with the
|
|
complex constraints attached to them. */
|
|
for (i = 0; i < graph->size; i++)
|
|
{
|
|
if (find (i) != i)
|
|
continue;
|
|
if (i < FIRST_REF_NODE)
|
|
fprintf (file, "\"%s\"", get_varinfo (i)->name);
|
|
else
|
|
fprintf (file, "\"*%s\"", get_varinfo (i - FIRST_REF_NODE)->name);
|
|
if (graph->complex[i])
|
|
{
|
|
unsigned j;
|
|
constraint_t c;
|
|
fprintf (file, " [label=\"\\N\\n");
|
|
for (j = 0; VEC_iterate (constraint_t, graph->complex[i], j, c); ++j)
|
|
{
|
|
dump_constraint (file, c);
|
|
fprintf (file, "\\l");
|
|
}
|
|
fprintf (file, "\"]");
|
|
}
|
|
fprintf (file, ";\n");
|
|
}
|
|
|
|
/* Go over the edges. */
|
|
fprintf (file, "\n // Edges in the constraint graph:\n");
|
|
for (i = 0; i < graph->size; i++)
|
|
{
|
|
unsigned j;
|
|
bitmap_iterator bi;
|
|
if (find (i) != i)
|
|
continue;
|
|
EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i], 0, j, bi)
|
|
{
|
|
unsigned to = find (j);
|
|
if (i == to)
|
|
continue;
|
|
if (i < FIRST_REF_NODE)
|
|
fprintf (file, "\"%s\"", get_varinfo (i)->name);
|
|
else
|
|
fprintf (file, "\"*%s\"", get_varinfo (i - FIRST_REF_NODE)->name);
|
|
fprintf (file, " -> ");
|
|
if (to < FIRST_REF_NODE)
|
|
fprintf (file, "\"%s\"", get_varinfo (to)->name);
|
|
else
|
|
fprintf (file, "\"*%s\"", get_varinfo (to - FIRST_REF_NODE)->name);
|
|
fprintf (file, ";\n");
|
|
}
|
|
}
|
|
|
|
/* Prints the tail of the dot file. */
|
|
fprintf (file, "}\n");
|
|
}
|
|
|
|
/* Print out the constraint graph to stderr. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_constraint_graph (void)
|
|
{
|
|
dump_constraint_graph (stderr);
|
|
}
|
|
|
|
/* SOLVER FUNCTIONS
|
|
|
|
The solver is a simple worklist solver, that works on the following
|
|
algorithm:
|
|
|
|
sbitmap changed_nodes = all zeroes;
|
|
changed_count = 0;
|
|
For each node that is not already collapsed:
|
|
changed_count++;
|
|
set bit in changed nodes
|
|
|
|
while (changed_count > 0)
|
|
{
|
|
compute topological ordering for constraint graph
|
|
|
|
find and collapse cycles in the constraint graph (updating
|
|
changed if necessary)
|
|
|
|
for each node (n) in the graph in topological order:
|
|
changed_count--;
|
|
|
|
Process each complex constraint associated with the node,
|
|
updating changed if necessary.
|
|
|
|
For each outgoing edge from n, propagate the solution from n to
|
|
the destination of the edge, updating changed as necessary.
|
|
|
|
} */
|
|
|
|
/* Return true if two constraint expressions A and B are equal. */
|
|
|
|
static bool
|
|
constraint_expr_equal (struct constraint_expr a, struct constraint_expr b)
|
|
{
|
|
return a.type == b.type && a.var == b.var && a.offset == b.offset;
|
|
}
|
|
|
|
/* Return true if constraint expression A is less than constraint expression
|
|
B. This is just arbitrary, but consistent, in order to give them an
|
|
ordering. */
|
|
|
|
static bool
|
|
constraint_expr_less (struct constraint_expr a, struct constraint_expr b)
|
|
{
|
|
if (a.type == b.type)
|
|
{
|
|
if (a.var == b.var)
|
|
return a.offset < b.offset;
|
|
else
|
|
return a.var < b.var;
|
|
}
|
|
else
|
|
return a.type < b.type;
|
|
}
|
|
|
|
/* Return true if constraint A is less than constraint B. This is just
|
|
arbitrary, but consistent, in order to give them an ordering. */
|
|
|
|
static bool
|
|
constraint_less (const constraint_t a, const constraint_t b)
|
|
{
|
|
if (constraint_expr_less (a->lhs, b->lhs))
|
|
return true;
|
|
else if (constraint_expr_less (b->lhs, a->lhs))
|
|
return false;
|
|
else
|
|
return constraint_expr_less (a->rhs, b->rhs);
|
|
}
|
|
|
|
/* Return true if two constraints A and B are equal. */
|
|
|
|
static bool
|
|
constraint_equal (struct constraint a, struct constraint b)
|
|
{
|
|
return constraint_expr_equal (a.lhs, b.lhs)
|
|
&& constraint_expr_equal (a.rhs, b.rhs);
|
|
}
|
|
|
|
|
|
/* Find a constraint LOOKFOR in the sorted constraint vector VEC */
|
|
|
|
static constraint_t
|
|
constraint_vec_find (VEC(constraint_t,heap) *vec,
|
|
struct constraint lookfor)
|
|
{
|
|
unsigned int place;
|
|
constraint_t found;
|
|
|
|
if (vec == NULL)
|
|
return NULL;
|
|
|
|
place = VEC_lower_bound (constraint_t, vec, &lookfor, constraint_less);
|
|
if (place >= VEC_length (constraint_t, vec))
|
|
return NULL;
|
|
found = VEC_index (constraint_t, vec, place);
|
|
if (!constraint_equal (*found, lookfor))
|
|
return NULL;
|
|
return found;
|
|
}
|
|
|
|
/* Union two constraint vectors, TO and FROM. Put the result in TO. */
|
|
|
|
static void
|
|
constraint_set_union (VEC(constraint_t,heap) **to,
|
|
VEC(constraint_t,heap) **from)
|
|
{
|
|
int i;
|
|
constraint_t c;
|
|
|
|
FOR_EACH_VEC_ELT (constraint_t, *from, i, c)
|
|
{
|
|
if (constraint_vec_find (*to, *c) == NULL)
|
|
{
|
|
unsigned int place = VEC_lower_bound (constraint_t, *to, c,
|
|
constraint_less);
|
|
VEC_safe_insert (constraint_t, heap, *to, place, c);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Expands the solution in SET to all sub-fields of variables included.
|
|
Union the expanded result into RESULT. */
|
|
|
|
static void
|
|
solution_set_expand (bitmap result, bitmap set)
|
|
{
|
|
bitmap_iterator bi;
|
|
bitmap vars = NULL;
|
|
unsigned j;
|
|
|
|
/* In a first pass record all variables we need to add all
|
|
sub-fields off. This avoids quadratic behavior. */
|
|
EXECUTE_IF_SET_IN_BITMAP (set, 0, j, bi)
|
|
{
|
|
varinfo_t v = get_varinfo (j);
|
|
if (v->is_artificial_var
|
|
|| v->is_full_var)
|
|
continue;
|
|
v = lookup_vi_for_tree (v->decl);
|
|
if (vars == NULL)
|
|
vars = BITMAP_ALLOC (NULL);
|
|
bitmap_set_bit (vars, v->id);
|
|
}
|
|
|
|
/* In the second pass now do the addition to the solution and
|
|
to speed up solving add it to the delta as well. */
|
|
if (vars != NULL)
|
|
{
|
|
EXECUTE_IF_SET_IN_BITMAP (vars, 0, j, bi)
|
|
{
|
|
varinfo_t v = get_varinfo (j);
|
|
for (; v != NULL; v = v->next)
|
|
bitmap_set_bit (result, v->id);
|
|
}
|
|
BITMAP_FREE (vars);
|
|
}
|
|
}
|
|
|
|
/* Take a solution set SET, add OFFSET to each member of the set, and
|
|
overwrite SET with the result when done. */
|
|
|
|
static void
|
|
solution_set_add (bitmap set, HOST_WIDE_INT offset)
|
|
{
|
|
bitmap result = BITMAP_ALLOC (&iteration_obstack);
|
|
unsigned int i;
|
|
bitmap_iterator bi;
|
|
|
|
/* If the offset is unknown we have to expand the solution to
|
|
all subfields. */
|
|
if (offset == UNKNOWN_OFFSET)
|
|
{
|
|
solution_set_expand (set, set);
|
|
return;
|
|
}
|
|
|
|
EXECUTE_IF_SET_IN_BITMAP (set, 0, i, bi)
|
|
{
|
|
varinfo_t vi = get_varinfo (i);
|
|
|
|
/* If this is a variable with just one field just set its bit
|
|
in the result. */
|
|
if (vi->is_artificial_var
|
|
|| vi->is_unknown_size_var
|
|
|| vi->is_full_var)
|
|
bitmap_set_bit (result, i);
|
|
else
|
|
{
|
|
unsigned HOST_WIDE_INT fieldoffset = vi->offset + offset;
|
|
|
|
/* If the offset makes the pointer point to before the
|
|
variable use offset zero for the field lookup. */
|
|
if (offset < 0
|
|
&& fieldoffset > vi->offset)
|
|
fieldoffset = 0;
|
|
|
|
if (offset != 0)
|
|
vi = first_or_preceding_vi_for_offset (vi, fieldoffset);
|
|
|
|
bitmap_set_bit (result, vi->id);
|
|
/* If the result is not exactly at fieldoffset include the next
|
|
field as well. See get_constraint_for_ptr_offset for more
|
|
rationale. */
|
|
if (vi->offset != fieldoffset
|
|
&& vi->next != NULL)
|
|
bitmap_set_bit (result, vi->next->id);
|
|
}
|
|
}
|
|
|
|
bitmap_copy (set, result);
|
|
BITMAP_FREE (result);
|
|
}
|
|
|
|
/* Union solution sets TO and FROM, and add INC to each member of FROM in the
|
|
process. */
|
|
|
|
static bool
|
|
set_union_with_increment (bitmap to, bitmap from, HOST_WIDE_INT inc)
|
|
{
|
|
if (inc == 0)
|
|
return bitmap_ior_into (to, from);
|
|
else
|
|
{
|
|
bitmap tmp;
|
|
bool res;
|
|
|
|
tmp = BITMAP_ALLOC (&iteration_obstack);
|
|
bitmap_copy (tmp, from);
|
|
solution_set_add (tmp, inc);
|
|
res = bitmap_ior_into (to, tmp);
|
|
BITMAP_FREE (tmp);
|
|
return res;
|
|
}
|
|
}
|
|
|
|
/* Insert constraint C into the list of complex constraints for graph
|
|
node VAR. */
|
|
|
|
static void
|
|
insert_into_complex (constraint_graph_t graph,
|
|
unsigned int var, constraint_t c)
|
|
{
|
|
VEC (constraint_t, heap) *complex = graph->complex[var];
|
|
unsigned int place = VEC_lower_bound (constraint_t, complex, c,
|
|
constraint_less);
|
|
|
|
/* Only insert constraints that do not already exist. */
|
|
if (place >= VEC_length (constraint_t, complex)
|
|
|| !constraint_equal (*c, *VEC_index (constraint_t, complex, place)))
|
|
VEC_safe_insert (constraint_t, heap, graph->complex[var], place, c);
|
|
}
|
|
|
|
|
|
/* Condense two variable nodes into a single variable node, by moving
|
|
all associated info from SRC to TO. */
|
|
|
|
static void
|
|
merge_node_constraints (constraint_graph_t graph, unsigned int to,
|
|
unsigned int from)
|
|
{
|
|
unsigned int i;
|
|
constraint_t c;
|
|
|
|
gcc_assert (find (from) == to);
|
|
|
|
/* Move all complex constraints from src node into to node */
|
|
FOR_EACH_VEC_ELT (constraint_t, graph->complex[from], i, c)
|
|
{
|
|
/* In complex constraints for node src, we may have either
|
|
a = *src, and *src = a, or an offseted constraint which are
|
|
always added to the rhs node's constraints. */
|
|
|
|
if (c->rhs.type == DEREF)
|
|
c->rhs.var = to;
|
|
else if (c->lhs.type == DEREF)
|
|
c->lhs.var = to;
|
|
else
|
|
c->rhs.var = to;
|
|
}
|
|
constraint_set_union (&graph->complex[to], &graph->complex[from]);
|
|
VEC_free (constraint_t, heap, graph->complex[from]);
|
|
graph->complex[from] = NULL;
|
|
}
|
|
|
|
|
|
/* Remove edges involving NODE from GRAPH. */
|
|
|
|
static void
|
|
clear_edges_for_node (constraint_graph_t graph, unsigned int node)
|
|
{
|
|
if (graph->succs[node])
|
|
BITMAP_FREE (graph->succs[node]);
|
|
}
|
|
|
|
/* Merge GRAPH nodes FROM and TO into node TO. */
|
|
|
|
static void
|
|
merge_graph_nodes (constraint_graph_t graph, unsigned int to,
|
|
unsigned int from)
|
|
{
|
|
if (graph->indirect_cycles[from] != -1)
|
|
{
|
|
/* If we have indirect cycles with the from node, and we have
|
|
none on the to node, the to node has indirect cycles from the
|
|
from node now that they are unified.
|
|
If indirect cycles exist on both, unify the nodes that they
|
|
are in a cycle with, since we know they are in a cycle with
|
|
each other. */
|
|
if (graph->indirect_cycles[to] == -1)
|
|
graph->indirect_cycles[to] = graph->indirect_cycles[from];
|
|
}
|
|
|
|
/* Merge all the successor edges. */
|
|
if (graph->succs[from])
|
|
{
|
|
if (!graph->succs[to])
|
|
graph->succs[to] = BITMAP_ALLOC (&pta_obstack);
|
|
bitmap_ior_into (graph->succs[to],
|
|
graph->succs[from]);
|
|
}
|
|
|
|
clear_edges_for_node (graph, from);
|
|
}
|
|
|
|
|
|
/* Add an indirect graph edge to GRAPH, going from TO to FROM if
|
|
it doesn't exist in the graph already. */
|
|
|
|
static void
|
|
add_implicit_graph_edge (constraint_graph_t graph, unsigned int to,
|
|
unsigned int from)
|
|
{
|
|
if (to == from)
|
|
return;
|
|
|
|
if (!graph->implicit_preds[to])
|
|
graph->implicit_preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
|
|
|
|
if (bitmap_set_bit (graph->implicit_preds[to], from))
|
|
stats.num_implicit_edges++;
|
|
}
|
|
|
|
/* Add a predecessor graph edge to GRAPH, going from TO to FROM if
|
|
it doesn't exist in the graph already.
|
|
Return false if the edge already existed, true otherwise. */
|
|
|
|
static void
|
|
add_pred_graph_edge (constraint_graph_t graph, unsigned int to,
|
|
unsigned int from)
|
|
{
|
|
if (!graph->preds[to])
|
|
graph->preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
|
|
bitmap_set_bit (graph->preds[to], from);
|
|
}
|
|
|
|
/* Add a graph edge to GRAPH, going from FROM to TO if
|
|
it doesn't exist in the graph already.
|
|
Return false if the edge already existed, true otherwise. */
|
|
|
|
static bool
|
|
add_graph_edge (constraint_graph_t graph, unsigned int to,
|
|
unsigned int from)
|
|
{
|
|
if (to == from)
|
|
{
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
bool r = false;
|
|
|
|
if (!graph->succs[from])
|
|
graph->succs[from] = BITMAP_ALLOC (&pta_obstack);
|
|
if (bitmap_set_bit (graph->succs[from], to))
|
|
{
|
|
r = true;
|
|
if (to < FIRST_REF_NODE && from < FIRST_REF_NODE)
|
|
stats.num_edges++;
|
|
}
|
|
return r;
|
|
}
|
|
}
|
|
|
|
|
|
/* Return true if {DEST.SRC} is an existing graph edge in GRAPH. */
|
|
|
|
static bool
|
|
valid_graph_edge (constraint_graph_t graph, unsigned int src,
|
|
unsigned int dest)
|
|
{
|
|
return (graph->succs[dest]
|
|
&& bitmap_bit_p (graph->succs[dest], src));
|
|
}
|
|
|
|
/* Initialize the constraint graph structure to contain SIZE nodes. */
|
|
|
|
static void
|
|
init_graph (unsigned int size)
|
|
{
|
|
unsigned int j;
|
|
|
|
graph = XCNEW (struct constraint_graph);
|
|
graph->size = size;
|
|
graph->succs = XCNEWVEC (bitmap, graph->size);
|
|
graph->indirect_cycles = XNEWVEC (int, graph->size);
|
|
graph->rep = XNEWVEC (unsigned int, graph->size);
|
|
graph->complex = XCNEWVEC (VEC(constraint_t, heap) *, size);
|
|
graph->pe = XCNEWVEC (unsigned int, graph->size);
|
|
graph->pe_rep = XNEWVEC (int, graph->size);
|
|
|
|
for (j = 0; j < graph->size; j++)
|
|
{
|
|
graph->rep[j] = j;
|
|
graph->pe_rep[j] = -1;
|
|
graph->indirect_cycles[j] = -1;
|
|
}
|
|
}
|
|
|
|
/* Build the constraint graph, adding only predecessor edges right now. */
|
|
|
|
static void
|
|
build_pred_graph (void)
|
|
{
|
|
int i;
|
|
constraint_t c;
|
|
unsigned int j;
|
|
|
|
graph->implicit_preds = XCNEWVEC (bitmap, graph->size);
|
|
graph->preds = XCNEWVEC (bitmap, graph->size);
|
|
graph->pointer_label = XCNEWVEC (unsigned int, graph->size);
|
|
graph->loc_label = XCNEWVEC (unsigned int, graph->size);
|
|
graph->pointed_by = XCNEWVEC (bitmap, graph->size);
|
|
graph->points_to = XCNEWVEC (bitmap, graph->size);
|
|
graph->eq_rep = XNEWVEC (int, graph->size);
|
|
graph->direct_nodes = sbitmap_alloc (graph->size);
|
|
graph->address_taken = BITMAP_ALLOC (&predbitmap_obstack);
|
|
sbitmap_zero (graph->direct_nodes);
|
|
|
|
for (j = 0; j < FIRST_REF_NODE; j++)
|
|
{
|
|
if (!get_varinfo (j)->is_special_var)
|
|
SET_BIT (graph->direct_nodes, j);
|
|
}
|
|
|
|
for (j = 0; j < graph->size; j++)
|
|
graph->eq_rep[j] = -1;
|
|
|
|
for (j = 0; j < VEC_length (varinfo_t, varmap); j++)
|
|
graph->indirect_cycles[j] = -1;
|
|
|
|
FOR_EACH_VEC_ELT (constraint_t, constraints, i, c)
|
|
{
|
|
struct constraint_expr lhs = c->lhs;
|
|
struct constraint_expr rhs = c->rhs;
|
|
unsigned int lhsvar = lhs.var;
|
|
unsigned int rhsvar = rhs.var;
|
|
|
|
if (lhs.type == DEREF)
|
|
{
|
|
/* *x = y. */
|
|
if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
|
|
add_pred_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
|
|
}
|
|
else if (rhs.type == DEREF)
|
|
{
|
|
/* x = *y */
|
|
if (rhs.offset == 0 && lhs.offset == 0 && lhs.type == SCALAR)
|
|
add_pred_graph_edge (graph, lhsvar, FIRST_REF_NODE + rhsvar);
|
|
else
|
|
RESET_BIT (graph->direct_nodes, lhsvar);
|
|
}
|
|
else if (rhs.type == ADDRESSOF)
|
|
{
|
|
varinfo_t v;
|
|
|
|
/* x = &y */
|
|
if (graph->points_to[lhsvar] == NULL)
|
|
graph->points_to[lhsvar] = BITMAP_ALLOC (&predbitmap_obstack);
|
|
bitmap_set_bit (graph->points_to[lhsvar], rhsvar);
|
|
|
|
if (graph->pointed_by[rhsvar] == NULL)
|
|
graph->pointed_by[rhsvar] = BITMAP_ALLOC (&predbitmap_obstack);
|
|
bitmap_set_bit (graph->pointed_by[rhsvar], lhsvar);
|
|
|
|
/* Implicitly, *x = y */
|
|
add_implicit_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
|
|
|
|
/* All related variables are no longer direct nodes. */
|
|
RESET_BIT (graph->direct_nodes, rhsvar);
|
|
v = get_varinfo (rhsvar);
|
|
if (!v->is_full_var)
|
|
{
|
|
v = lookup_vi_for_tree (v->decl);
|
|
do
|
|
{
|
|
RESET_BIT (graph->direct_nodes, v->id);
|
|
v = v->next;
|
|
}
|
|
while (v != NULL);
|
|
}
|
|
bitmap_set_bit (graph->address_taken, rhsvar);
|
|
}
|
|
else if (lhsvar > anything_id
|
|
&& lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
|
|
{
|
|
/* x = y */
|
|
add_pred_graph_edge (graph, lhsvar, rhsvar);
|
|
/* Implicitly, *x = *y */
|
|
add_implicit_graph_edge (graph, FIRST_REF_NODE + lhsvar,
|
|
FIRST_REF_NODE + rhsvar);
|
|
}
|
|
else if (lhs.offset != 0 || rhs.offset != 0)
|
|
{
|
|
if (rhs.offset != 0)
|
|
RESET_BIT (graph->direct_nodes, lhs.var);
|
|
else if (lhs.offset != 0)
|
|
RESET_BIT (graph->direct_nodes, rhs.var);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Build the constraint graph, adding successor edges. */
|
|
|
|
static void
|
|
build_succ_graph (void)
|
|
{
|
|
unsigned i, t;
|
|
constraint_t c;
|
|
|
|
FOR_EACH_VEC_ELT (constraint_t, constraints, i, c)
|
|
{
|
|
struct constraint_expr lhs;
|
|
struct constraint_expr rhs;
|
|
unsigned int lhsvar;
|
|
unsigned int rhsvar;
|
|
|
|
if (!c)
|
|
continue;
|
|
|
|
lhs = c->lhs;
|
|
rhs = c->rhs;
|
|
lhsvar = find (lhs.var);
|
|
rhsvar = find (rhs.var);
|
|
|
|
if (lhs.type == DEREF)
|
|
{
|
|
if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
|
|
add_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
|
|
}
|
|
else if (rhs.type == DEREF)
|
|
{
|
|
if (rhs.offset == 0 && lhs.offset == 0 && lhs.type == SCALAR)
|
|
add_graph_edge (graph, lhsvar, FIRST_REF_NODE + rhsvar);
|
|
}
|
|
else if (rhs.type == ADDRESSOF)
|
|
{
|
|
/* x = &y */
|
|
gcc_assert (find (rhs.var) == rhs.var);
|
|
bitmap_set_bit (get_varinfo (lhsvar)->solution, rhsvar);
|
|
}
|
|
else if (lhsvar > anything_id
|
|
&& lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
|
|
{
|
|
add_graph_edge (graph, lhsvar, rhsvar);
|
|
}
|
|
}
|
|
|
|
/* Add edges from STOREDANYTHING to all non-direct nodes that can
|
|
receive pointers. */
|
|
t = find (storedanything_id);
|
|
for (i = integer_id + 1; i < FIRST_REF_NODE; ++i)
|
|
{
|
|
if (!TEST_BIT (graph->direct_nodes, i)
|
|
&& get_varinfo (i)->may_have_pointers)
|
|
add_graph_edge (graph, find (i), t);
|
|
}
|
|
|
|
/* Everything stored to ANYTHING also potentially escapes. */
|
|
add_graph_edge (graph, find (escaped_id), t);
|
|
}
|
|
|
|
|
|
/* Changed variables on the last iteration. */
|
|
static bitmap changed;
|
|
|
|
/* Strongly Connected Component visitation info. */
|
|
|
|
struct scc_info
|
|
{
|
|
sbitmap visited;
|
|
sbitmap deleted;
|
|
unsigned int *dfs;
|
|
unsigned int *node_mapping;
|
|
int current_index;
|
|
VEC(unsigned,heap) *scc_stack;
|
|
};
|
|
|
|
|
|
/* Recursive routine to find strongly connected components in GRAPH.
|
|
SI is the SCC info to store the information in, and N is the id of current
|
|
graph node we are processing.
|
|
|
|
This is Tarjan's strongly connected component finding algorithm, as
|
|
modified by Nuutila to keep only non-root nodes on the stack.
|
|
The algorithm can be found in "On finding the strongly connected
|
|
connected components in a directed graph" by Esko Nuutila and Eljas
|
|
Soisalon-Soininen, in Information Processing Letters volume 49,
|
|
number 1, pages 9-14. */
|
|
|
|
static void
|
|
scc_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
|
|
{
|
|
unsigned int i;
|
|
bitmap_iterator bi;
|
|
unsigned int my_dfs;
|
|
|
|
SET_BIT (si->visited, n);
|
|
si->dfs[n] = si->current_index ++;
|
|
my_dfs = si->dfs[n];
|
|
|
|
/* Visit all the successors. */
|
|
EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[n], 0, i, bi)
|
|
{
|
|
unsigned int w;
|
|
|
|
if (i > LAST_REF_NODE)
|
|
break;
|
|
|
|
w = find (i);
|
|
if (TEST_BIT (si->deleted, w))
|
|
continue;
|
|
|
|
if (!TEST_BIT (si->visited, w))
|
|
scc_visit (graph, si, w);
|
|
{
|
|
unsigned int t = find (w);
|
|
unsigned int nnode = find (n);
|
|
gcc_assert (nnode == n);
|
|
|
|
if (si->dfs[t] < si->dfs[nnode])
|
|
si->dfs[n] = si->dfs[t];
|
|
}
|
|
}
|
|
|
|
/* See if any components have been identified. */
|
|
if (si->dfs[n] == my_dfs)
|
|
{
|
|
if (VEC_length (unsigned, si->scc_stack) > 0
|
|
&& si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
|
|
{
|
|
bitmap scc = BITMAP_ALLOC (NULL);
|
|
unsigned int lowest_node;
|
|
bitmap_iterator bi;
|
|
|
|
bitmap_set_bit (scc, n);
|
|
|
|
while (VEC_length (unsigned, si->scc_stack) != 0
|
|
&& si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
|
|
{
|
|
unsigned int w = VEC_pop (unsigned, si->scc_stack);
|
|
|
|
bitmap_set_bit (scc, w);
|
|
}
|
|
|
|
lowest_node = bitmap_first_set_bit (scc);
|
|
gcc_assert (lowest_node < FIRST_REF_NODE);
|
|
|
|
/* Collapse the SCC nodes into a single node, and mark the
|
|
indirect cycles. */
|
|
EXECUTE_IF_SET_IN_BITMAP (scc, 0, i, bi)
|
|
{
|
|
if (i < FIRST_REF_NODE)
|
|
{
|
|
if (unite (lowest_node, i))
|
|
unify_nodes (graph, lowest_node, i, false);
|
|
}
|
|
else
|
|
{
|
|
unite (lowest_node, i);
|
|
graph->indirect_cycles[i - FIRST_REF_NODE] = lowest_node;
|
|
}
|
|
}
|
|
}
|
|
SET_BIT (si->deleted, n);
|
|
}
|
|
else
|
|
VEC_safe_push (unsigned, heap, si->scc_stack, n);
|
|
}
|
|
|
|
/* Unify node FROM into node TO, updating the changed count if
|
|
necessary when UPDATE_CHANGED is true. */
|
|
|
|
static void
|
|
unify_nodes (constraint_graph_t graph, unsigned int to, unsigned int from,
|
|
bool update_changed)
|
|
{
|
|
|
|
gcc_assert (to != from && find (to) == to);
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, "Unifying %s to %s\n",
|
|
get_varinfo (from)->name,
|
|
get_varinfo (to)->name);
|
|
|
|
if (update_changed)
|
|
stats.unified_vars_dynamic++;
|
|
else
|
|
stats.unified_vars_static++;
|
|
|
|
merge_graph_nodes (graph, to, from);
|
|
merge_node_constraints (graph, to, from);
|
|
|
|
/* Mark TO as changed if FROM was changed. If TO was already marked
|
|
as changed, decrease the changed count. */
|
|
|
|
if (update_changed
|
|
&& bitmap_bit_p (changed, from))
|
|
{
|
|
bitmap_clear_bit (changed, from);
|
|
bitmap_set_bit (changed, to);
|
|
}
|
|
if (get_varinfo (from)->solution)
|
|
{
|
|
/* If the solution changes because of the merging, we need to mark
|
|
the variable as changed. */
|
|
if (bitmap_ior_into (get_varinfo (to)->solution,
|
|
get_varinfo (from)->solution))
|
|
{
|
|
if (update_changed)
|
|
bitmap_set_bit (changed, to);
|
|
}
|
|
|
|
BITMAP_FREE (get_varinfo (from)->solution);
|
|
if (get_varinfo (from)->oldsolution)
|
|
BITMAP_FREE (get_varinfo (from)->oldsolution);
|
|
|
|
if (stats.iterations > 0
|
|
&& get_varinfo (to)->oldsolution)
|
|
BITMAP_FREE (get_varinfo (to)->oldsolution);
|
|
}
|
|
if (valid_graph_edge (graph, to, to))
|
|
{
|
|
if (graph->succs[to])
|
|
bitmap_clear_bit (graph->succs[to], to);
|
|
}
|
|
}
|
|
|
|
/* Information needed to compute the topological ordering of a graph. */
|
|
|
|
struct topo_info
|
|
{
|
|
/* sbitmap of visited nodes. */
|
|
sbitmap visited;
|
|
/* Array that stores the topological order of the graph, *in
|
|
reverse*. */
|
|
VEC(unsigned,heap) *topo_order;
|
|
};
|
|
|
|
|
|
/* Initialize and return a topological info structure. */
|
|
|
|
static struct topo_info *
|
|
init_topo_info (void)
|
|
{
|
|
size_t size = graph->size;
|
|
struct topo_info *ti = XNEW (struct topo_info);
|
|
ti->visited = sbitmap_alloc (size);
|
|
sbitmap_zero (ti->visited);
|
|
ti->topo_order = VEC_alloc (unsigned, heap, 1);
|
|
return ti;
|
|
}
|
|
|
|
|
|
/* Free the topological sort info pointed to by TI. */
|
|
|
|
static void
|
|
free_topo_info (struct topo_info *ti)
|
|
{
|
|
sbitmap_free (ti->visited);
|
|
VEC_free (unsigned, heap, ti->topo_order);
|
|
free (ti);
|
|
}
|
|
|
|
/* Visit the graph in topological order, and store the order in the
|
|
topo_info structure. */
|
|
|
|
static void
|
|
topo_visit (constraint_graph_t graph, struct topo_info *ti,
|
|
unsigned int n)
|
|
{
|
|
bitmap_iterator bi;
|
|
unsigned int j;
|
|
|
|
SET_BIT (ti->visited, n);
|
|
|
|
if (graph->succs[n])
|
|
EXECUTE_IF_SET_IN_BITMAP (graph->succs[n], 0, j, bi)
|
|
{
|
|
if (!TEST_BIT (ti->visited, j))
|
|
topo_visit (graph, ti, j);
|
|
}
|
|
|
|
VEC_safe_push (unsigned, heap, ti->topo_order, n);
|
|
}
|
|
|
|
/* Process a constraint C that represents x = *(y + off), using DELTA as the
|
|
starting solution for y. */
|
|
|
|
static void
|
|
do_sd_constraint (constraint_graph_t graph, constraint_t c,
|
|
bitmap delta)
|
|
{
|
|
unsigned int lhs = c->lhs.var;
|
|
bool flag = false;
|
|
bitmap sol = get_varinfo (lhs)->solution;
|
|
unsigned int j;
|
|
bitmap_iterator bi;
|
|
HOST_WIDE_INT roffset = c->rhs.offset;
|
|
|
|
/* Our IL does not allow this. */
|
|
gcc_assert (c->lhs.offset == 0);
|
|
|
|
/* If the solution of Y contains anything it is good enough to transfer
|
|
this to the LHS. */
|
|
if (bitmap_bit_p (delta, anything_id))
|
|
{
|
|
flag |= bitmap_set_bit (sol, anything_id);
|
|
goto done;
|
|
}
|
|
|
|
/* If we do not know at with offset the rhs is dereferenced compute
|
|
the reachability set of DELTA, conservatively assuming it is
|
|
dereferenced at all valid offsets. */
|
|
if (roffset == UNKNOWN_OFFSET)
|
|
{
|
|
solution_set_expand (delta, delta);
|
|
/* No further offset processing is necessary. */
|
|
roffset = 0;
|
|
}
|
|
|
|
/* For each variable j in delta (Sol(y)), add
|
|
an edge in the graph from j to x, and union Sol(j) into Sol(x). */
|
|
EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
|
|
{
|
|
varinfo_t v = get_varinfo (j);
|
|
HOST_WIDE_INT fieldoffset = v->offset + roffset;
|
|
unsigned int t;
|
|
|
|
if (v->is_full_var)
|
|
fieldoffset = v->offset;
|
|
else if (roffset != 0)
|
|
v = first_vi_for_offset (v, fieldoffset);
|
|
/* If the access is outside of the variable we can ignore it. */
|
|
if (!v)
|
|
continue;
|
|
|
|
do
|
|
{
|
|
t = find (v->id);
|
|
|
|
/* Adding edges from the special vars is pointless.
|
|
They don't have sets that can change. */
|
|
if (get_varinfo (t)->is_special_var)
|
|
flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
|
|
/* Merging the solution from ESCAPED needlessly increases
|
|
the set. Use ESCAPED as representative instead. */
|
|
else if (v->id == escaped_id)
|
|
flag |= bitmap_set_bit (sol, escaped_id);
|
|
else if (v->may_have_pointers
|
|
&& add_graph_edge (graph, lhs, t))
|
|
flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
|
|
|
|
/* If the variable is not exactly at the requested offset
|
|
we have to include the next one. */
|
|
if (v->offset == (unsigned HOST_WIDE_INT)fieldoffset
|
|
|| v->next == NULL)
|
|
break;
|
|
|
|
v = v->next;
|
|
fieldoffset = v->offset;
|
|
}
|
|
while (1);
|
|
}
|
|
|
|
done:
|
|
/* If the LHS solution changed, mark the var as changed. */
|
|
if (flag)
|
|
{
|
|
get_varinfo (lhs)->solution = sol;
|
|
bitmap_set_bit (changed, lhs);
|
|
}
|
|
}
|
|
|
|
/* Process a constraint C that represents *(x + off) = y using DELTA
|
|
as the starting solution for x. */
|
|
|
|
static void
|
|
do_ds_constraint (constraint_t c, bitmap delta)
|
|
{
|
|
unsigned int rhs = c->rhs.var;
|
|
bitmap sol = get_varinfo (rhs)->solution;
|
|
unsigned int j;
|
|
bitmap_iterator bi;
|
|
HOST_WIDE_INT loff = c->lhs.offset;
|
|
bool escaped_p = false;
|
|
|
|
/* Our IL does not allow this. */
|
|
gcc_assert (c->rhs.offset == 0);
|
|
|
|
/* If the solution of y contains ANYTHING simply use the ANYTHING
|
|
solution. This avoids needlessly increasing the points-to sets. */
|
|
if (bitmap_bit_p (sol, anything_id))
|
|
sol = get_varinfo (find (anything_id))->solution;
|
|
|
|
/* If the solution for x contains ANYTHING we have to merge the
|
|
solution of y into all pointer variables which we do via
|
|
STOREDANYTHING. */
|
|
if (bitmap_bit_p (delta, anything_id))
|
|
{
|
|
unsigned t = find (storedanything_id);
|
|
if (add_graph_edge (graph, t, rhs))
|
|
{
|
|
if (bitmap_ior_into (get_varinfo (t)->solution, sol))
|
|
bitmap_set_bit (changed, t);
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* If we do not know at with offset the rhs is dereferenced compute
|
|
the reachability set of DELTA, conservatively assuming it is
|
|
dereferenced at all valid offsets. */
|
|
if (loff == UNKNOWN_OFFSET)
|
|
{
|
|
solution_set_expand (delta, delta);
|
|
loff = 0;
|
|
}
|
|
|
|
/* For each member j of delta (Sol(x)), add an edge from y to j and
|
|
union Sol(y) into Sol(j) */
|
|
EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
|
|
{
|
|
varinfo_t v = get_varinfo (j);
|
|
unsigned int t;
|
|
HOST_WIDE_INT fieldoffset = v->offset + loff;
|
|
|
|
if (v->is_full_var)
|
|
fieldoffset = v->offset;
|
|
else if (loff != 0)
|
|
v = first_vi_for_offset (v, fieldoffset);
|
|
/* If the access is outside of the variable we can ignore it. */
|
|
if (!v)
|
|
continue;
|
|
|
|
do
|
|
{
|
|
if (v->may_have_pointers)
|
|
{
|
|
/* If v is a global variable then this is an escape point. */
|
|
if (v->is_global_var
|
|
&& !escaped_p)
|
|
{
|
|
t = find (escaped_id);
|
|
if (add_graph_edge (graph, t, rhs)
|
|
&& bitmap_ior_into (get_varinfo (t)->solution, sol))
|
|
bitmap_set_bit (changed, t);
|
|
/* Enough to let rhs escape once. */
|
|
escaped_p = true;
|
|
}
|
|
|
|
if (v->is_special_var)
|
|
break;
|
|
|
|
t = find (v->id);
|
|
if (add_graph_edge (graph, t, rhs)
|
|
&& bitmap_ior_into (get_varinfo (t)->solution, sol))
|
|
bitmap_set_bit (changed, t);
|
|
}
|
|
|
|
/* If the variable is not exactly at the requested offset
|
|
we have to include the next one. */
|
|
if (v->offset == (unsigned HOST_WIDE_INT)fieldoffset
|
|
|| v->next == NULL)
|
|
break;
|
|
|
|
v = v->next;
|
|
fieldoffset = v->offset;
|
|
}
|
|
while (1);
|
|
}
|
|
}
|
|
|
|
/* Handle a non-simple (simple meaning requires no iteration),
|
|
constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
|
|
|
|
static void
|
|
do_complex_constraint (constraint_graph_t graph, constraint_t c, bitmap delta)
|
|
{
|
|
if (c->lhs.type == DEREF)
|
|
{
|
|
if (c->rhs.type == ADDRESSOF)
|
|
{
|
|
gcc_unreachable();
|
|
}
|
|
else
|
|
{
|
|
/* *x = y */
|
|
do_ds_constraint (c, delta);
|
|
}
|
|
}
|
|
else if (c->rhs.type == DEREF)
|
|
{
|
|
/* x = *y */
|
|
if (!(get_varinfo (c->lhs.var)->is_special_var))
|
|
do_sd_constraint (graph, c, delta);
|
|
}
|
|
else
|
|
{
|
|
bitmap tmp;
|
|
bitmap solution;
|
|
bool flag = false;
|
|
|
|
gcc_assert (c->rhs.type == SCALAR && c->lhs.type == SCALAR);
|
|
solution = get_varinfo (c->rhs.var)->solution;
|
|
tmp = get_varinfo (c->lhs.var)->solution;
|
|
|
|
flag = set_union_with_increment (tmp, solution, c->rhs.offset);
|
|
|
|
if (flag)
|
|
{
|
|
get_varinfo (c->lhs.var)->solution = tmp;
|
|
bitmap_set_bit (changed, c->lhs.var);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Initialize and return a new SCC info structure. */
|
|
|
|
static struct scc_info *
|
|
init_scc_info (size_t size)
|
|
{
|
|
struct scc_info *si = XNEW (struct scc_info);
|
|
size_t i;
|
|
|
|
si->current_index = 0;
|
|
si->visited = sbitmap_alloc (size);
|
|
sbitmap_zero (si->visited);
|
|
si->deleted = sbitmap_alloc (size);
|
|
sbitmap_zero (si->deleted);
|
|
si->node_mapping = XNEWVEC (unsigned int, size);
|
|
si->dfs = XCNEWVEC (unsigned int, size);
|
|
|
|
for (i = 0; i < size; i++)
|
|
si->node_mapping[i] = i;
|
|
|
|
si->scc_stack = VEC_alloc (unsigned, heap, 1);
|
|
return si;
|
|
}
|
|
|
|
/* Free an SCC info structure pointed to by SI */
|
|
|
|
static void
|
|
free_scc_info (struct scc_info *si)
|
|
{
|
|
sbitmap_free (si->visited);
|
|
sbitmap_free (si->deleted);
|
|
free (si->node_mapping);
|
|
free (si->dfs);
|
|
VEC_free (unsigned, heap, si->scc_stack);
|
|
free (si);
|
|
}
|
|
|
|
|
|
/* Find indirect cycles in GRAPH that occur, using strongly connected
|
|
components, and note them in the indirect cycles map.
|
|
|
|
This technique comes from Ben Hardekopf and Calvin Lin,
|
|
"It Pays to be Lazy: Fast and Accurate Pointer Analysis for Millions of
|
|
Lines of Code", submitted to PLDI 2007. */
|
|
|
|
static void
|
|
find_indirect_cycles (constraint_graph_t graph)
|
|
{
|
|
unsigned int i;
|
|
unsigned int size = graph->size;
|
|
struct scc_info *si = init_scc_info (size);
|
|
|
|
for (i = 0; i < MIN (LAST_REF_NODE, size); i ++ )
|
|
if (!TEST_BIT (si->visited, i) && find (i) == i)
|
|
scc_visit (graph, si, i);
|
|
|
|
free_scc_info (si);
|
|
}
|
|
|
|
/* Compute a topological ordering for GRAPH, and store the result in the
|
|
topo_info structure TI. */
|
|
|
|
static void
|
|
compute_topo_order (constraint_graph_t graph,
|
|
struct topo_info *ti)
|
|
{
|
|
unsigned int i;
|
|
unsigned int size = graph->size;
|
|
|
|
for (i = 0; i != size; ++i)
|
|
if (!TEST_BIT (ti->visited, i) && find (i) == i)
|
|
topo_visit (graph, ti, i);
|
|
}
|
|
|
|
/* Structure used to for hash value numbering of pointer equivalence
|
|
classes. */
|
|
|
|
typedef struct equiv_class_label
|
|
{
|
|
hashval_t hashcode;
|
|
unsigned int equivalence_class;
|
|
bitmap labels;
|
|
} *equiv_class_label_t;
|
|
typedef const struct equiv_class_label *const_equiv_class_label_t;
|
|
|
|
/* A hashtable for mapping a bitmap of labels->pointer equivalence
|
|
classes. */
|
|
static htab_t pointer_equiv_class_table;
|
|
|
|
/* A hashtable for mapping a bitmap of labels->location equivalence
|
|
classes. */
|
|
static htab_t location_equiv_class_table;
|
|
|
|
/* Hash function for a equiv_class_label_t */
|
|
|
|
static hashval_t
|
|
equiv_class_label_hash (const void *p)
|
|
{
|
|
const_equiv_class_label_t const ecl = (const_equiv_class_label_t) p;
|
|
return ecl->hashcode;
|
|
}
|
|
|
|
/* Equality function for two equiv_class_label_t's. */
|
|
|
|
static int
|
|
equiv_class_label_eq (const void *p1, const void *p2)
|
|
{
|
|
const_equiv_class_label_t const eql1 = (const_equiv_class_label_t) p1;
|
|
const_equiv_class_label_t const eql2 = (const_equiv_class_label_t) p2;
|
|
return (eql1->hashcode == eql2->hashcode
|
|
&& bitmap_equal_p (eql1->labels, eql2->labels));
|
|
}
|
|
|
|
/* Lookup a equivalence class in TABLE by the bitmap of LABELS it
|
|
contains. */
|
|
|
|
static unsigned int
|
|
equiv_class_lookup (htab_t table, bitmap labels)
|
|
{
|
|
void **slot;
|
|
struct equiv_class_label ecl;
|
|
|
|
ecl.labels = labels;
|
|
ecl.hashcode = bitmap_hash (labels);
|
|
|
|
slot = htab_find_slot_with_hash (table, &ecl,
|
|
ecl.hashcode, NO_INSERT);
|
|
if (!slot)
|
|
return 0;
|
|
else
|
|
return ((equiv_class_label_t) *slot)->equivalence_class;
|
|
}
|
|
|
|
|
|
/* Add an equivalence class named EQUIVALENCE_CLASS with labels LABELS
|
|
to TABLE. */
|
|
|
|
static void
|
|
equiv_class_add (htab_t table, unsigned int equivalence_class,
|
|
bitmap labels)
|
|
{
|
|
void **slot;
|
|
equiv_class_label_t ecl = XNEW (struct equiv_class_label);
|
|
|
|
ecl->labels = labels;
|
|
ecl->equivalence_class = equivalence_class;
|
|
ecl->hashcode = bitmap_hash (labels);
|
|
|
|
slot = htab_find_slot_with_hash (table, ecl,
|
|
ecl->hashcode, INSERT);
|
|
gcc_assert (!*slot);
|
|
*slot = (void *) ecl;
|
|
}
|
|
|
|
/* Perform offline variable substitution.
|
|
|
|
This is a worst case quadratic time way of identifying variables
|
|
that must have equivalent points-to sets, including those caused by
|
|
static cycles, and single entry subgraphs, in the constraint graph.
|
|
|
|
The technique is described in "Exploiting Pointer and Location
|
|
Equivalence to Optimize Pointer Analysis. In the 14th International
|
|
Static Analysis Symposium (SAS), August 2007." It is known as the
|
|
"HU" algorithm, and is equivalent to value numbering the collapsed
|
|
constraint graph including evaluating unions.
|
|
|
|
The general method of finding equivalence classes is as follows:
|
|
Add fake nodes (REF nodes) and edges for *a = b and a = *b constraints.
|
|
Initialize all non-REF nodes to be direct nodes.
|
|
For each constraint a = a U {b}, we set pts(a) = pts(a) u {fresh
|
|
variable}
|
|
For each constraint containing the dereference, we also do the same
|
|
thing.
|
|
|
|
We then compute SCC's in the graph and unify nodes in the same SCC,
|
|
including pts sets.
|
|
|
|
For each non-collapsed node x:
|
|
Visit all unvisited explicit incoming edges.
|
|
Ignoring all non-pointers, set pts(x) = Union of pts(a) for y
|
|
where y->x.
|
|
Lookup the equivalence class for pts(x).
|
|
If we found one, equivalence_class(x) = found class.
|
|
Otherwise, equivalence_class(x) = new class, and new_class is
|
|
added to the lookup table.
|
|
|
|
All direct nodes with the same equivalence class can be replaced
|
|
with a single representative node.
|
|
All unlabeled nodes (label == 0) are not pointers and all edges
|
|
involving them can be eliminated.
|
|
We perform these optimizations during rewrite_constraints
|
|
|
|
In addition to pointer equivalence class finding, we also perform
|
|
location equivalence class finding. This is the set of variables
|
|
that always appear together in points-to sets. We use this to
|
|
compress the size of the points-to sets. */
|
|
|
|
/* Current maximum pointer equivalence class id. */
|
|
static int pointer_equiv_class;
|
|
|
|
/* Current maximum location equivalence class id. */
|
|
static int location_equiv_class;
|
|
|
|
/* Recursive routine to find strongly connected components in GRAPH,
|
|
and label it's nodes with DFS numbers. */
|
|
|
|
static void
|
|
condense_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
|
|
{
|
|
unsigned int i;
|
|
bitmap_iterator bi;
|
|
unsigned int my_dfs;
|
|
|
|
gcc_assert (si->node_mapping[n] == n);
|
|
SET_BIT (si->visited, n);
|
|
si->dfs[n] = si->current_index ++;
|
|
my_dfs = si->dfs[n];
|
|
|
|
/* Visit all the successors. */
|
|
EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
|
|
{
|
|
unsigned int w = si->node_mapping[i];
|
|
|
|
if (TEST_BIT (si->deleted, w))
|
|
continue;
|
|
|
|
if (!TEST_BIT (si->visited, w))
|
|
condense_visit (graph, si, w);
|
|
{
|
|
unsigned int t = si->node_mapping[w];
|
|
unsigned int nnode = si->node_mapping[n];
|
|
gcc_assert (nnode == n);
|
|
|
|
if (si->dfs[t] < si->dfs[nnode])
|
|
si->dfs[n] = si->dfs[t];
|
|
}
|
|
}
|
|
|
|
/* Visit all the implicit predecessors. */
|
|
EXECUTE_IF_IN_NONNULL_BITMAP (graph->implicit_preds[n], 0, i, bi)
|
|
{
|
|
unsigned int w = si->node_mapping[i];
|
|
|
|
if (TEST_BIT (si->deleted, w))
|
|
continue;
|
|
|
|
if (!TEST_BIT (si->visited, w))
|
|
condense_visit (graph, si, w);
|
|
{
|
|
unsigned int t = si->node_mapping[w];
|
|
unsigned int nnode = si->node_mapping[n];
|
|
gcc_assert (nnode == n);
|
|
|
|
if (si->dfs[t] < si->dfs[nnode])
|
|
si->dfs[n] = si->dfs[t];
|
|
}
|
|
}
|
|
|
|
/* See if any components have been identified. */
|
|
if (si->dfs[n] == my_dfs)
|
|
{
|
|
while (VEC_length (unsigned, si->scc_stack) != 0
|
|
&& si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
|
|
{
|
|
unsigned int w = VEC_pop (unsigned, si->scc_stack);
|
|
si->node_mapping[w] = n;
|
|
|
|
if (!TEST_BIT (graph->direct_nodes, w))
|
|
RESET_BIT (graph->direct_nodes, n);
|
|
|
|
/* Unify our nodes. */
|
|
if (graph->preds[w])
|
|
{
|
|
if (!graph->preds[n])
|
|
graph->preds[n] = BITMAP_ALLOC (&predbitmap_obstack);
|
|
bitmap_ior_into (graph->preds[n], graph->preds[w]);
|
|
}
|
|
if (graph->implicit_preds[w])
|
|
{
|
|
if (!graph->implicit_preds[n])
|
|
graph->implicit_preds[n] = BITMAP_ALLOC (&predbitmap_obstack);
|
|
bitmap_ior_into (graph->implicit_preds[n],
|
|
graph->implicit_preds[w]);
|
|
}
|
|
if (graph->points_to[w])
|
|
{
|
|
if (!graph->points_to[n])
|
|
graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack);
|
|
bitmap_ior_into (graph->points_to[n],
|
|
graph->points_to[w]);
|
|
}
|
|
}
|
|
SET_BIT (si->deleted, n);
|
|
}
|
|
else
|
|
VEC_safe_push (unsigned, heap, si->scc_stack, n);
|
|
}
|
|
|
|
/* Label pointer equivalences. */
|
|
|
|
static void
|
|
label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
|
|
{
|
|
unsigned int i;
|
|
bitmap_iterator bi;
|
|
SET_BIT (si->visited, n);
|
|
|
|
if (!graph->points_to[n])
|
|
graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack);
|
|
|
|
/* Label and union our incoming edges's points to sets. */
|
|
EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
|
|
{
|
|
unsigned int w = si->node_mapping[i];
|
|
if (!TEST_BIT (si->visited, w))
|
|
label_visit (graph, si, w);
|
|
|
|
/* Skip unused edges */
|
|
if (w == n || graph->pointer_label[w] == 0)
|
|
continue;
|
|
|
|
if (graph->points_to[w])
|
|
bitmap_ior_into(graph->points_to[n], graph->points_to[w]);
|
|
}
|
|
/* Indirect nodes get fresh variables. */
|
|
if (!TEST_BIT (graph->direct_nodes, n))
|
|
bitmap_set_bit (graph->points_to[n], FIRST_REF_NODE + n);
|
|
|
|
if (!bitmap_empty_p (graph->points_to[n]))
|
|
{
|
|
unsigned int label = equiv_class_lookup (pointer_equiv_class_table,
|
|
graph->points_to[n]);
|
|
if (!label)
|
|
{
|
|
label = pointer_equiv_class++;
|
|
equiv_class_add (pointer_equiv_class_table,
|
|
label, graph->points_to[n]);
|
|
}
|
|
graph->pointer_label[n] = label;
|
|
}
|
|
}
|
|
|
|
/* Perform offline variable substitution, discovering equivalence
|
|
classes, and eliminating non-pointer variables. */
|
|
|
|
static struct scc_info *
|
|
perform_var_substitution (constraint_graph_t graph)
|
|
{
|
|
unsigned int i;
|
|
unsigned int size = graph->size;
|
|
struct scc_info *si = init_scc_info (size);
|
|
|
|
bitmap_obstack_initialize (&iteration_obstack);
|
|
pointer_equiv_class_table = htab_create (511, equiv_class_label_hash,
|
|
equiv_class_label_eq, free);
|
|
location_equiv_class_table = htab_create (511, equiv_class_label_hash,
|
|
equiv_class_label_eq, free);
|
|
pointer_equiv_class = 1;
|
|
location_equiv_class = 1;
|
|
|
|
/* Condense the nodes, which means to find SCC's, count incoming
|
|
predecessors, and unite nodes in SCC's. */
|
|
for (i = 0; i < FIRST_REF_NODE; i++)
|
|
if (!TEST_BIT (si->visited, si->node_mapping[i]))
|
|
condense_visit (graph, si, si->node_mapping[i]);
|
|
|
|
sbitmap_zero (si->visited);
|
|
/* Actually the label the nodes for pointer equivalences */
|
|
for (i = 0; i < FIRST_REF_NODE; i++)
|
|
if (!TEST_BIT (si->visited, si->node_mapping[i]))
|
|
label_visit (graph, si, si->node_mapping[i]);
|
|
|
|
/* Calculate location equivalence labels. */
|
|
for (i = 0; i < FIRST_REF_NODE; i++)
|
|
{
|
|
bitmap pointed_by;
|
|
bitmap_iterator bi;
|
|
unsigned int j;
|
|
unsigned int label;
|
|
|
|
if (!graph->pointed_by[i])
|
|
continue;
|
|
pointed_by = BITMAP_ALLOC (&iteration_obstack);
|
|
|
|
/* Translate the pointed-by mapping for pointer equivalence
|
|
labels. */
|
|
EXECUTE_IF_SET_IN_BITMAP (graph->pointed_by[i], 0, j, bi)
|
|
{
|
|
bitmap_set_bit (pointed_by,
|
|
graph->pointer_label[si->node_mapping[j]]);
|
|
}
|
|
/* The original pointed_by is now dead. */
|
|
BITMAP_FREE (graph->pointed_by[i]);
|
|
|
|
/* Look up the location equivalence label if one exists, or make
|
|
one otherwise. */
|
|
label = equiv_class_lookup (location_equiv_class_table,
|
|
pointed_by);
|
|
if (label == 0)
|
|
{
|
|
label = location_equiv_class++;
|
|
equiv_class_add (location_equiv_class_table,
|
|
label, pointed_by);
|
|
}
|
|
else
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, "Found location equivalence for node %s\n",
|
|
get_varinfo (i)->name);
|
|
BITMAP_FREE (pointed_by);
|
|
}
|
|
graph->loc_label[i] = label;
|
|
|
|
}
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
for (i = 0; i < FIRST_REF_NODE; i++)
|
|
{
|
|
bool direct_node = TEST_BIT (graph->direct_nodes, i);
|
|
fprintf (dump_file,
|
|
"Equivalence classes for %s node id %d:%s are pointer: %d"
|
|
", location:%d\n",
|
|
direct_node ? "Direct node" : "Indirect node", i,
|
|
get_varinfo (i)->name,
|
|
graph->pointer_label[si->node_mapping[i]],
|
|
graph->loc_label[si->node_mapping[i]]);
|
|
}
|
|
|
|
/* Quickly eliminate our non-pointer variables. */
|
|
|
|
for (i = 0; i < FIRST_REF_NODE; i++)
|
|
{
|
|
unsigned int node = si->node_mapping[i];
|
|
|
|
if (graph->pointer_label[node] == 0)
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file,
|
|
"%s is a non-pointer variable, eliminating edges.\n",
|
|
get_varinfo (node)->name);
|
|
stats.nonpointer_vars++;
|
|
clear_edges_for_node (graph, node);
|
|
}
|
|
}
|
|
|
|
return si;
|
|
}
|
|
|
|
/* Free information that was only necessary for variable
|
|
substitution. */
|
|
|
|
static void
|
|
free_var_substitution_info (struct scc_info *si)
|
|
{
|
|
free_scc_info (si);
|
|
free (graph->pointer_label);
|
|
free (graph->loc_label);
|
|
free (graph->pointed_by);
|
|
free (graph->points_to);
|
|
free (graph->eq_rep);
|
|
sbitmap_free (graph->direct_nodes);
|
|
htab_delete (pointer_equiv_class_table);
|
|
htab_delete (location_equiv_class_table);
|
|
bitmap_obstack_release (&iteration_obstack);
|
|
}
|
|
|
|
/* Return an existing node that is equivalent to NODE, which has
|
|
equivalence class LABEL, if one exists. Return NODE otherwise. */
|
|
|
|
static unsigned int
|
|
find_equivalent_node (constraint_graph_t graph,
|
|
unsigned int node, unsigned int label)
|
|
{
|
|
/* If the address version of this variable is unused, we can
|
|
substitute it for anything else with the same label.
|
|
Otherwise, we know the pointers are equivalent, but not the
|
|
locations, and we can unite them later. */
|
|
|
|
if (!bitmap_bit_p (graph->address_taken, node))
|
|
{
|
|
gcc_assert (label < graph->size);
|
|
|
|
if (graph->eq_rep[label] != -1)
|
|
{
|
|
/* Unify the two variables since we know they are equivalent. */
|
|
if (unite (graph->eq_rep[label], node))
|
|
unify_nodes (graph, graph->eq_rep[label], node, false);
|
|
return graph->eq_rep[label];
|
|
}
|
|
else
|
|
{
|
|
graph->eq_rep[label] = node;
|
|
graph->pe_rep[label] = node;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
gcc_assert (label < graph->size);
|
|
graph->pe[node] = label;
|
|
if (graph->pe_rep[label] == -1)
|
|
graph->pe_rep[label] = node;
|
|
}
|
|
|
|
return node;
|
|
}
|
|
|
|
/* Unite pointer equivalent but not location equivalent nodes in
|
|
GRAPH. This may only be performed once variable substitution is
|
|
finished. */
|
|
|
|
static void
|
|
unite_pointer_equivalences (constraint_graph_t graph)
|
|
{
|
|
unsigned int i;
|
|
|
|
/* Go through the pointer equivalences and unite them to their
|
|
representative, if they aren't already. */
|
|
for (i = 0; i < FIRST_REF_NODE; i++)
|
|
{
|
|
unsigned int label = graph->pe[i];
|
|
if (label)
|
|
{
|
|
int label_rep = graph->pe_rep[label];
|
|
|
|
if (label_rep == -1)
|
|
continue;
|
|
|
|
label_rep = find (label_rep);
|
|
if (label_rep >= 0 && unite (label_rep, find (i)))
|
|
unify_nodes (graph, label_rep, i, false);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Move complex constraints to the GRAPH nodes they belong to. */
|
|
|
|
static void
|
|
move_complex_constraints (constraint_graph_t graph)
|
|
{
|
|
int i;
|
|
constraint_t c;
|
|
|
|
FOR_EACH_VEC_ELT (constraint_t, constraints, i, c)
|
|
{
|
|
if (c)
|
|
{
|
|
struct constraint_expr lhs = c->lhs;
|
|
struct constraint_expr rhs = c->rhs;
|
|
|
|
if (lhs.type == DEREF)
|
|
{
|
|
insert_into_complex (graph, lhs.var, c);
|
|
}
|
|
else if (rhs.type == DEREF)
|
|
{
|
|
if (!(get_varinfo (lhs.var)->is_special_var))
|
|
insert_into_complex (graph, rhs.var, c);
|
|
}
|
|
else if (rhs.type != ADDRESSOF && lhs.var > anything_id
|
|
&& (lhs.offset != 0 || rhs.offset != 0))
|
|
{
|
|
insert_into_complex (graph, rhs.var, c);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/* Optimize and rewrite complex constraints while performing
|
|
collapsing of equivalent nodes. SI is the SCC_INFO that is the
|
|
result of perform_variable_substitution. */
|
|
|
|
static void
|
|
rewrite_constraints (constraint_graph_t graph,
|
|
struct scc_info *si)
|
|
{
|
|
int i;
|
|
unsigned int j;
|
|
constraint_t c;
|
|
|
|
for (j = 0; j < graph->size; j++)
|
|
gcc_assert (find (j) == j);
|
|
|
|
FOR_EACH_VEC_ELT (constraint_t, constraints, i, c)
|
|
{
|
|
struct constraint_expr lhs = c->lhs;
|
|
struct constraint_expr rhs = c->rhs;
|
|
unsigned int lhsvar = find (lhs.var);
|
|
unsigned int rhsvar = find (rhs.var);
|
|
unsigned int lhsnode, rhsnode;
|
|
unsigned int lhslabel, rhslabel;
|
|
|
|
lhsnode = si->node_mapping[lhsvar];
|
|
rhsnode = si->node_mapping[rhsvar];
|
|
lhslabel = graph->pointer_label[lhsnode];
|
|
rhslabel = graph->pointer_label[rhsnode];
|
|
|
|
/* See if it is really a non-pointer variable, and if so, ignore
|
|
the constraint. */
|
|
if (lhslabel == 0)
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
|
|
fprintf (dump_file, "%s is a non-pointer variable,"
|
|
"ignoring constraint:",
|
|
get_varinfo (lhs.var)->name);
|
|
dump_constraint (dump_file, c);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
VEC_replace (constraint_t, constraints, i, NULL);
|
|
continue;
|
|
}
|
|
|
|
if (rhslabel == 0)
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
|
|
fprintf (dump_file, "%s is a non-pointer variable,"
|
|
"ignoring constraint:",
|
|
get_varinfo (rhs.var)->name);
|
|
dump_constraint (dump_file, c);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
VEC_replace (constraint_t, constraints, i, NULL);
|
|
continue;
|
|
}
|
|
|
|
lhsvar = find_equivalent_node (graph, lhsvar, lhslabel);
|
|
rhsvar = find_equivalent_node (graph, rhsvar, rhslabel);
|
|
c->lhs.var = lhsvar;
|
|
c->rhs.var = rhsvar;
|
|
|
|
}
|
|
}
|
|
|
|
/* Eliminate indirect cycles involving NODE. Return true if NODE was
|
|
part of an SCC, false otherwise. */
|
|
|
|
static bool
|
|
eliminate_indirect_cycles (unsigned int node)
|
|
{
|
|
if (graph->indirect_cycles[node] != -1
|
|
&& !bitmap_empty_p (get_varinfo (node)->solution))
|
|
{
|
|
unsigned int i;
|
|
VEC(unsigned,heap) *queue = NULL;
|
|
int queuepos;
|
|
unsigned int to = find (graph->indirect_cycles[node]);
|
|
bitmap_iterator bi;
|
|
|
|
/* We can't touch the solution set and call unify_nodes
|
|
at the same time, because unify_nodes is going to do
|
|
bitmap unions into it. */
|
|
|
|
EXECUTE_IF_SET_IN_BITMAP (get_varinfo (node)->solution, 0, i, bi)
|
|
{
|
|
if (find (i) == i && i != to)
|
|
{
|
|
if (unite (to, i))
|
|
VEC_safe_push (unsigned, heap, queue, i);
|
|
}
|
|
}
|
|
|
|
for (queuepos = 0;
|
|
VEC_iterate (unsigned, queue, queuepos, i);
|
|
queuepos++)
|
|
{
|
|
unify_nodes (graph, to, i, true);
|
|
}
|
|
VEC_free (unsigned, heap, queue);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Solve the constraint graph GRAPH using our worklist solver.
|
|
This is based on the PW* family of solvers from the "Efficient Field
|
|
Sensitive Pointer Analysis for C" paper.
|
|
It works by iterating over all the graph nodes, processing the complex
|
|
constraints and propagating the copy constraints, until everything stops
|
|
changed. This corresponds to steps 6-8 in the solving list given above. */
|
|
|
|
static void
|
|
solve_graph (constraint_graph_t graph)
|
|
{
|
|
unsigned int size = graph->size;
|
|
unsigned int i;
|
|
bitmap pts;
|
|
|
|
changed = BITMAP_ALLOC (NULL);
|
|
|
|
/* Mark all initial non-collapsed nodes as changed. */
|
|
for (i = 0; i < size; i++)
|
|
{
|
|
varinfo_t ivi = get_varinfo (i);
|
|
if (find (i) == i && !bitmap_empty_p (ivi->solution)
|
|
&& ((graph->succs[i] && !bitmap_empty_p (graph->succs[i]))
|
|
|| VEC_length (constraint_t, graph->complex[i]) > 0))
|
|
bitmap_set_bit (changed, i);
|
|
}
|
|
|
|
/* Allocate a bitmap to be used to store the changed bits. */
|
|
pts = BITMAP_ALLOC (&pta_obstack);
|
|
|
|
while (!bitmap_empty_p (changed))
|
|
{
|
|
unsigned int i;
|
|
struct topo_info *ti = init_topo_info ();
|
|
stats.iterations++;
|
|
|
|
bitmap_obstack_initialize (&iteration_obstack);
|
|
|
|
compute_topo_order (graph, ti);
|
|
|
|
while (VEC_length (unsigned, ti->topo_order) != 0)
|
|
{
|
|
|
|
i = VEC_pop (unsigned, ti->topo_order);
|
|
|
|
/* If this variable is not a representative, skip it. */
|
|
if (find (i) != i)
|
|
continue;
|
|
|
|
/* In certain indirect cycle cases, we may merge this
|
|
variable to another. */
|
|
if (eliminate_indirect_cycles (i) && find (i) != i)
|
|
continue;
|
|
|
|
/* If the node has changed, we need to process the
|
|
complex constraints and outgoing edges again. */
|
|
if (bitmap_clear_bit (changed, i))
|
|
{
|
|
unsigned int j;
|
|
constraint_t c;
|
|
bitmap solution;
|
|
VEC(constraint_t,heap) *complex = graph->complex[i];
|
|
varinfo_t vi = get_varinfo (i);
|
|
bool solution_empty;
|
|
|
|
/* Compute the changed set of solution bits. */
|
|
if (vi->oldsolution)
|
|
bitmap_and_compl (pts, vi->solution, vi->oldsolution);
|
|
else
|
|
bitmap_copy (pts, vi->solution);
|
|
|
|
if (bitmap_empty_p (pts))
|
|
continue;
|
|
|
|
if (vi->oldsolution)
|
|
bitmap_ior_into (vi->oldsolution, pts);
|
|
else
|
|
{
|
|
vi->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
|
|
bitmap_copy (vi->oldsolution, pts);
|
|
}
|
|
|
|
solution = vi->solution;
|
|
solution_empty = bitmap_empty_p (solution);
|
|
|
|
/* Process the complex constraints */
|
|
FOR_EACH_VEC_ELT (constraint_t, complex, j, c)
|
|
{
|
|
/* XXX: This is going to unsort the constraints in
|
|
some cases, which will occasionally add duplicate
|
|
constraints during unification. This does not
|
|
affect correctness. */
|
|
c->lhs.var = find (c->lhs.var);
|
|
c->rhs.var = find (c->rhs.var);
|
|
|
|
/* The only complex constraint that can change our
|
|
solution to non-empty, given an empty solution,
|
|
is a constraint where the lhs side is receiving
|
|
some set from elsewhere. */
|
|
if (!solution_empty || c->lhs.type != DEREF)
|
|
do_complex_constraint (graph, c, pts);
|
|
}
|
|
|
|
solution_empty = bitmap_empty_p (solution);
|
|
|
|
if (!solution_empty)
|
|
{
|
|
bitmap_iterator bi;
|
|
unsigned eff_escaped_id = find (escaped_id);
|
|
|
|
/* Propagate solution to all successors. */
|
|
EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i],
|
|
0, j, bi)
|
|
{
|
|
bitmap tmp;
|
|
bool flag;
|
|
|
|
unsigned int to = find (j);
|
|
tmp = get_varinfo (to)->solution;
|
|
flag = false;
|
|
|
|
/* Don't try to propagate to ourselves. */
|
|
if (to == i)
|
|
continue;
|
|
|
|
/* If we propagate from ESCAPED use ESCAPED as
|
|
placeholder. */
|
|
if (i == eff_escaped_id)
|
|
flag = bitmap_set_bit (tmp, escaped_id);
|
|
else
|
|
flag = set_union_with_increment (tmp, pts, 0);
|
|
|
|
if (flag)
|
|
{
|
|
get_varinfo (to)->solution = tmp;
|
|
bitmap_set_bit (changed, to);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
free_topo_info (ti);
|
|
bitmap_obstack_release (&iteration_obstack);
|
|
}
|
|
|
|
BITMAP_FREE (pts);
|
|
BITMAP_FREE (changed);
|
|
bitmap_obstack_release (&oldpta_obstack);
|
|
}
|
|
|
|
/* Map from trees to variable infos. */
|
|
static struct pointer_map_t *vi_for_tree;
|
|
|
|
|
|
/* Insert ID as the variable id for tree T in the vi_for_tree map. */
|
|
|
|
static void
|
|
insert_vi_for_tree (tree t, varinfo_t vi)
|
|
{
|
|
void **slot = pointer_map_insert (vi_for_tree, t);
|
|
gcc_assert (vi);
|
|
gcc_assert (*slot == NULL);
|
|
*slot = vi;
|
|
}
|
|
|
|
/* Find the variable info for tree T in VI_FOR_TREE. If T does not
|
|
exist in the map, return NULL, otherwise, return the varinfo we found. */
|
|
|
|
static varinfo_t
|
|
lookup_vi_for_tree (tree t)
|
|
{
|
|
void **slot = pointer_map_contains (vi_for_tree, t);
|
|
if (slot == NULL)
|
|
return NULL;
|
|
|
|
return (varinfo_t) *slot;
|
|
}
|
|
|
|
/* Return a printable name for DECL */
|
|
|
|
static const char *
|
|
alias_get_name (tree decl)
|
|
{
|
|
const char *res;
|
|
char *temp;
|
|
int num_printed = 0;
|
|
|
|
if (DECL_ASSEMBLER_NAME_SET_P (decl))
|
|
res = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
|
|
else
|
|
res= get_name (decl);
|
|
if (res != NULL)
|
|
return res;
|
|
|
|
res = "NULL";
|
|
if (!dump_file)
|
|
return res;
|
|
|
|
if (TREE_CODE (decl) == SSA_NAME)
|
|
{
|
|
num_printed = asprintf (&temp, "%s_%u",
|
|
alias_get_name (SSA_NAME_VAR (decl)),
|
|
SSA_NAME_VERSION (decl));
|
|
}
|
|
else if (DECL_P (decl))
|
|
{
|
|
num_printed = asprintf (&temp, "D.%u", DECL_UID (decl));
|
|
}
|
|
if (num_printed > 0)
|
|
{
|
|
res = ggc_strdup (temp);
|
|
free (temp);
|
|
}
|
|
return res;
|
|
}
|
|
|
|
/* Find the variable id for tree T in the map.
|
|
If T doesn't exist in the map, create an entry for it and return it. */
|
|
|
|
static varinfo_t
|
|
get_vi_for_tree (tree t)
|
|
{
|
|
void **slot = pointer_map_contains (vi_for_tree, t);
|
|
if (slot == NULL)
|
|
return get_varinfo (create_variable_info_for (t, alias_get_name (t)));
|
|
|
|
return (varinfo_t) *slot;
|
|
}
|
|
|
|
/* Get a scalar constraint expression for a new temporary variable. */
|
|
|
|
static struct constraint_expr
|
|
new_scalar_tmp_constraint_exp (const char *name)
|
|
{
|
|
struct constraint_expr tmp;
|
|
varinfo_t vi;
|
|
|
|
vi = new_var_info (NULL_TREE, name);
|
|
vi->offset = 0;
|
|
vi->size = -1;
|
|
vi->fullsize = -1;
|
|
vi->is_full_var = 1;
|
|
|
|
tmp.var = vi->id;
|
|
tmp.type = SCALAR;
|
|
tmp.offset = 0;
|
|
|
|
return tmp;
|
|
}
|
|
|
|
/* Get a constraint expression vector from an SSA_VAR_P node.
|
|
If address_p is true, the result will be taken its address of. */
|
|
|
|
static void
|
|
get_constraint_for_ssa_var (tree t, VEC(ce_s, heap) **results, bool address_p)
|
|
{
|
|
struct constraint_expr cexpr;
|
|
varinfo_t vi;
|
|
|
|
/* We allow FUNCTION_DECLs here even though it doesn't make much sense. */
|
|
gcc_assert (SSA_VAR_P (t) || DECL_P (t));
|
|
|
|
/* For parameters, get at the points-to set for the actual parm
|
|
decl. */
|
|
if (TREE_CODE (t) == SSA_NAME
|
|
&& (TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL
|
|
|| TREE_CODE (SSA_NAME_VAR (t)) == RESULT_DECL)
|
|
&& SSA_NAME_IS_DEFAULT_DEF (t))
|
|
{
|
|
get_constraint_for_ssa_var (SSA_NAME_VAR (t), results, address_p);
|
|
return;
|
|
}
|
|
|
|
/* For global variables resort to the alias target. */
|
|
if (TREE_CODE (t) == VAR_DECL
|
|
&& (TREE_STATIC (t) || DECL_EXTERNAL (t)))
|
|
{
|
|
struct varpool_node *node = varpool_get_node (t);
|
|
if (node && node->alias)
|
|
{
|
|
node = varpool_variable_node (node, NULL);
|
|
t = node->decl;
|
|
}
|
|
}
|
|
|
|
vi = get_vi_for_tree (t);
|
|
cexpr.var = vi->id;
|
|
cexpr.type = SCALAR;
|
|
cexpr.offset = 0;
|
|
/* If we determine the result is "anything", and we know this is readonly,
|
|
say it points to readonly memory instead. */
|
|
if (cexpr.var == anything_id && TREE_READONLY (t))
|
|
{
|
|
gcc_unreachable ();
|
|
cexpr.type = ADDRESSOF;
|
|
cexpr.var = readonly_id;
|
|
}
|
|
|
|
/* If we are not taking the address of the constraint expr, add all
|
|
sub-fiels of the variable as well. */
|
|
if (!address_p
|
|
&& !vi->is_full_var)
|
|
{
|
|
for (; vi; vi = vi->next)
|
|
{
|
|
cexpr.var = vi->id;
|
|
VEC_safe_push (ce_s, heap, *results, &cexpr);
|
|
}
|
|
return;
|
|
}
|
|
|
|
VEC_safe_push (ce_s, heap, *results, &cexpr);
|
|
}
|
|
|
|
/* Process constraint T, performing various simplifications and then
|
|
adding it to our list of overall constraints. */
|
|
|
|
static void
|
|
process_constraint (constraint_t t)
|
|
{
|
|
struct constraint_expr rhs = t->rhs;
|
|
struct constraint_expr lhs = t->lhs;
|
|
|
|
gcc_assert (rhs.var < VEC_length (varinfo_t, varmap));
|
|
gcc_assert (lhs.var < VEC_length (varinfo_t, varmap));
|
|
|
|
/* If we didn't get any useful constraint from the lhs we get
|
|
&ANYTHING as fallback from get_constraint_for. Deal with
|
|
it here by turning it into *ANYTHING. */
|
|
if (lhs.type == ADDRESSOF
|
|
&& lhs.var == anything_id)
|
|
lhs.type = DEREF;
|
|
|
|
/* ADDRESSOF on the lhs is invalid. */
|
|
gcc_assert (lhs.type != ADDRESSOF);
|
|
|
|
/* We shouldn't add constraints from things that cannot have pointers.
|
|
It's not completely trivial to avoid in the callers, so do it here. */
|
|
if (rhs.type != ADDRESSOF
|
|
&& !get_varinfo (rhs.var)->may_have_pointers)
|
|
return;
|
|
|
|
/* Likewise adding to the solution of a non-pointer var isn't useful. */
|
|
if (!get_varinfo (lhs.var)->may_have_pointers)
|
|
return;
|
|
|
|
/* This can happen in our IR with things like n->a = *p */
|
|
if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
|
|
{
|
|
/* Split into tmp = *rhs, *lhs = tmp */
|
|
struct constraint_expr tmplhs;
|
|
tmplhs = new_scalar_tmp_constraint_exp ("doubledereftmp");
|
|
process_constraint (new_constraint (tmplhs, rhs));
|
|
process_constraint (new_constraint (lhs, tmplhs));
|
|
}
|
|
else if (rhs.type == ADDRESSOF && lhs.type == DEREF)
|
|
{
|
|
/* Split into tmp = &rhs, *lhs = tmp */
|
|
struct constraint_expr tmplhs;
|
|
tmplhs = new_scalar_tmp_constraint_exp ("derefaddrtmp");
|
|
process_constraint (new_constraint (tmplhs, rhs));
|
|
process_constraint (new_constraint (lhs, tmplhs));
|
|
}
|
|
else
|
|
{
|
|
gcc_assert (rhs.type != ADDRESSOF || rhs.offset == 0);
|
|
VEC_safe_push (constraint_t, heap, constraints, t);
|
|
}
|
|
}
|
|
|
|
|
|
/* Return the position, in bits, of FIELD_DECL from the beginning of its
|
|
structure. */
|
|
|
|
static HOST_WIDE_INT
|
|
bitpos_of_field (const tree fdecl)
|
|
{
|
|
if (!host_integerp (DECL_FIELD_OFFSET (fdecl), 0)
|
|
|| !host_integerp (DECL_FIELD_BIT_OFFSET (fdecl), 0))
|
|
return -1;
|
|
|
|
return (TREE_INT_CST_LOW (DECL_FIELD_OFFSET (fdecl)) * BITS_PER_UNIT
|
|
+ TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fdecl)));
|
|
}
|
|
|
|
|
|
/* Get constraint expressions for offsetting PTR by OFFSET. Stores the
|
|
resulting constraint expressions in *RESULTS. */
|
|
|
|
static void
|
|
get_constraint_for_ptr_offset (tree ptr, tree offset,
|
|
VEC (ce_s, heap) **results)
|
|
{
|
|
struct constraint_expr c;
|
|
unsigned int j, n;
|
|
HOST_WIDE_INT rhsoffset;
|
|
|
|
/* If we do not do field-sensitive PTA adding offsets to pointers
|
|
does not change the points-to solution. */
|
|
if (!use_field_sensitive)
|
|
{
|
|
get_constraint_for_rhs (ptr, results);
|
|
return;
|
|
}
|
|
|
|
/* If the offset is not a non-negative integer constant that fits
|
|
in a HOST_WIDE_INT, we have to fall back to a conservative
|
|
solution which includes all sub-fields of all pointed-to
|
|
variables of ptr. */
|
|
if (offset == NULL_TREE
|
|
|| TREE_CODE (offset) != INTEGER_CST)
|
|
rhsoffset = UNKNOWN_OFFSET;
|
|
else
|
|
{
|
|
/* Sign-extend the offset. */
|
|
double_int soffset
|
|
= double_int_sext (tree_to_double_int (offset),
|
|
TYPE_PRECISION (TREE_TYPE (offset)));
|
|
if (!double_int_fits_in_shwi_p (soffset))
|
|
rhsoffset = UNKNOWN_OFFSET;
|
|
else
|
|
{
|
|
/* Make sure the bit-offset also fits. */
|
|
HOST_WIDE_INT rhsunitoffset = soffset.low;
|
|
rhsoffset = rhsunitoffset * BITS_PER_UNIT;
|
|
if (rhsunitoffset != rhsoffset / BITS_PER_UNIT)
|
|
rhsoffset = UNKNOWN_OFFSET;
|
|
}
|
|
}
|
|
|
|
get_constraint_for_rhs (ptr, results);
|
|
if (rhsoffset == 0)
|
|
return;
|
|
|
|
/* As we are eventually appending to the solution do not use
|
|
VEC_iterate here. */
|
|
n = VEC_length (ce_s, *results);
|
|
for (j = 0; j < n; j++)
|
|
{
|
|
varinfo_t curr;
|
|
c = *VEC_index (ce_s, *results, j);
|
|
curr = get_varinfo (c.var);
|
|
|
|
if (c.type == ADDRESSOF
|
|
/* If this varinfo represents a full variable just use it. */
|
|
&& curr->is_full_var)
|
|
c.offset = 0;
|
|
else if (c.type == ADDRESSOF
|
|
/* If we do not know the offset add all subfields. */
|
|
&& rhsoffset == UNKNOWN_OFFSET)
|
|
{
|
|
varinfo_t temp = lookup_vi_for_tree (curr->decl);
|
|
do
|
|
{
|
|
struct constraint_expr c2;
|
|
c2.var = temp->id;
|
|
c2.type = ADDRESSOF;
|
|
c2.offset = 0;
|
|
if (c2.var != c.var)
|
|
VEC_safe_push (ce_s, heap, *results, &c2);
|
|
temp = temp->next;
|
|
}
|
|
while (temp);
|
|
}
|
|
else if (c.type == ADDRESSOF)
|
|
{
|
|
varinfo_t temp;
|
|
unsigned HOST_WIDE_INT offset = curr->offset + rhsoffset;
|
|
|
|
/* Search the sub-field which overlaps with the
|
|
pointed-to offset. If the result is outside of the variable
|
|
we have to provide a conservative result, as the variable is
|
|
still reachable from the resulting pointer (even though it
|
|
technically cannot point to anything). The last and first
|
|
sub-fields are such conservative results.
|
|
??? If we always had a sub-field for &object + 1 then
|
|
we could represent this in a more precise way. */
|
|
if (rhsoffset < 0
|
|
&& curr->offset < offset)
|
|
offset = 0;
|
|
temp = first_or_preceding_vi_for_offset (curr, offset);
|
|
|
|
/* If the found variable is not exactly at the pointed to
|
|
result, we have to include the next variable in the
|
|
solution as well. Otherwise two increments by offset / 2
|
|
do not result in the same or a conservative superset
|
|
solution. */
|
|
if (temp->offset != offset
|
|
&& temp->next != NULL)
|
|
{
|
|
struct constraint_expr c2;
|
|
c2.var = temp->next->id;
|
|
c2.type = ADDRESSOF;
|
|
c2.offset = 0;
|
|
VEC_safe_push (ce_s, heap, *results, &c2);
|
|
}
|
|
c.var = temp->id;
|
|
c.offset = 0;
|
|
}
|
|
else
|
|
c.offset = rhsoffset;
|
|
|
|
VEC_replace (ce_s, *results, j, &c);
|
|
}
|
|
}
|
|
|
|
|
|
/* Given a COMPONENT_REF T, return the constraint_expr vector for it.
|
|
If address_p is true the result will be taken its address of.
|
|
If lhs_p is true then the constraint expression is assumed to be used
|
|
as the lhs. */
|
|
|
|
static void
|
|
get_constraint_for_component_ref (tree t, VEC(ce_s, heap) **results,
|
|
bool address_p, bool lhs_p)
|
|
{
|
|
tree orig_t = t;
|
|
HOST_WIDE_INT bitsize = -1;
|
|
HOST_WIDE_INT bitmaxsize = -1;
|
|
HOST_WIDE_INT bitpos;
|
|
tree forzero;
|
|
struct constraint_expr *result;
|
|
|
|
/* Some people like to do cute things like take the address of
|
|
&0->a.b */
|
|
forzero = t;
|
|
while (handled_component_p (forzero)
|
|
|| INDIRECT_REF_P (forzero)
|
|
|| TREE_CODE (forzero) == MEM_REF)
|
|
forzero = TREE_OPERAND (forzero, 0);
|
|
|
|
if (CONSTANT_CLASS_P (forzero) && integer_zerop (forzero))
|
|
{
|
|
struct constraint_expr temp;
|
|
|
|
temp.offset = 0;
|
|
temp.var = integer_id;
|
|
temp.type = SCALAR;
|
|
VEC_safe_push (ce_s, heap, *results, &temp);
|
|
return;
|
|
}
|
|
|
|
/* Handle type-punning through unions. If we are extracting a pointer
|
|
from a union via a possibly type-punning access that pointer
|
|
points to anything, similar to a conversion of an integer to
|
|
a pointer. */
|
|
if (!lhs_p)
|
|
{
|
|
tree u;
|
|
for (u = t;
|
|
TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
|
|
u = TREE_OPERAND (u, 0))
|
|
if (TREE_CODE (u) == COMPONENT_REF
|
|
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
|
|
{
|
|
struct constraint_expr temp;
|
|
|
|
temp.offset = 0;
|
|
temp.var = anything_id;
|
|
temp.type = ADDRESSOF;
|
|
VEC_safe_push (ce_s, heap, *results, &temp);
|
|
return;
|
|
}
|
|
}
|
|
|
|
t = get_ref_base_and_extent (t, &bitpos, &bitsize, &bitmaxsize);
|
|
|
|
/* Pretend to take the address of the base, we'll take care of
|
|
adding the required subset of sub-fields below. */
|
|
get_constraint_for_1 (t, results, true, lhs_p);
|
|
gcc_assert (VEC_length (ce_s, *results) == 1);
|
|
result = VEC_last (ce_s, *results);
|
|
|
|
if (result->type == SCALAR
|
|
&& get_varinfo (result->var)->is_full_var)
|
|
/* For single-field vars do not bother about the offset. */
|
|
result->offset = 0;
|
|
else if (result->type == SCALAR)
|
|
{
|
|
/* In languages like C, you can access one past the end of an
|
|
array. You aren't allowed to dereference it, so we can
|
|
ignore this constraint. When we handle pointer subtraction,
|
|
we may have to do something cute here. */
|
|
|
|
if ((unsigned HOST_WIDE_INT)bitpos < get_varinfo (result->var)->fullsize
|
|
&& bitmaxsize != 0)
|
|
{
|
|
/* It's also not true that the constraint will actually start at the
|
|
right offset, it may start in some padding. We only care about
|
|
setting the constraint to the first actual field it touches, so
|
|
walk to find it. */
|
|
struct constraint_expr cexpr = *result;
|
|
varinfo_t curr;
|
|
VEC_pop (ce_s, *results);
|
|
cexpr.offset = 0;
|
|
for (curr = get_varinfo (cexpr.var); curr; curr = curr->next)
|
|
{
|
|
if (ranges_overlap_p (curr->offset, curr->size,
|
|
bitpos, bitmaxsize))
|
|
{
|
|
cexpr.var = curr->id;
|
|
VEC_safe_push (ce_s, heap, *results, &cexpr);
|
|
if (address_p)
|
|
break;
|
|
}
|
|
}
|
|
/* If we are going to take the address of this field then
|
|
to be able to compute reachability correctly add at least
|
|
the last field of the variable. */
|
|
if (address_p
|
|
&& VEC_length (ce_s, *results) == 0)
|
|
{
|
|
curr = get_varinfo (cexpr.var);
|
|
while (curr->next != NULL)
|
|
curr = curr->next;
|
|
cexpr.var = curr->id;
|
|
VEC_safe_push (ce_s, heap, *results, &cexpr);
|
|
}
|
|
else if (VEC_length (ce_s, *results) == 0)
|
|
/* Assert that we found *some* field there. The user couldn't be
|
|
accessing *only* padding. */
|
|
/* Still the user could access one past the end of an array
|
|
embedded in a struct resulting in accessing *only* padding. */
|
|
/* Or accessing only padding via type-punning to a type
|
|
that has a filed just in padding space. */
|
|
{
|
|
cexpr.type = SCALAR;
|
|
cexpr.var = anything_id;
|
|
cexpr.offset = 0;
|
|
VEC_safe_push (ce_s, heap, *results, &cexpr);
|
|
}
|
|
}
|
|
else if (bitmaxsize == 0)
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, "Access to zero-sized part of variable,"
|
|
"ignoring\n");
|
|
}
|
|
else
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, "Access to past the end of variable, ignoring\n");
|
|
}
|
|
else if (result->type == DEREF)
|
|
{
|
|
/* If we do not know exactly where the access goes say so. Note
|
|
that only for non-structure accesses we know that we access
|
|
at most one subfiled of any variable. */
|
|
if (bitpos == -1
|
|
|| bitsize != bitmaxsize
|
|
|| AGGREGATE_TYPE_P (TREE_TYPE (orig_t))
|
|
|| result->offset == UNKNOWN_OFFSET)
|
|
result->offset = UNKNOWN_OFFSET;
|
|
else
|
|
result->offset += bitpos;
|
|
}
|
|
else if (result->type == ADDRESSOF)
|
|
{
|
|
/* We can end up here for component references on a
|
|
VIEW_CONVERT_EXPR <>(&foobar). */
|
|
result->type = SCALAR;
|
|
result->var = anything_id;
|
|
result->offset = 0;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
|
|
/* Dereference the constraint expression CONS, and return the result.
|
|
DEREF (ADDRESSOF) = SCALAR
|
|
DEREF (SCALAR) = DEREF
|
|
DEREF (DEREF) = (temp = DEREF1; result = DEREF(temp))
|
|
This is needed so that we can handle dereferencing DEREF constraints. */
|
|
|
|
static void
|
|
do_deref (VEC (ce_s, heap) **constraints)
|
|
{
|
|
struct constraint_expr *c;
|
|
unsigned int i = 0;
|
|
|
|
FOR_EACH_VEC_ELT (ce_s, *constraints, i, c)
|
|
{
|
|
if (c->type == SCALAR)
|
|
c->type = DEREF;
|
|
else if (c->type == ADDRESSOF)
|
|
c->type = SCALAR;
|
|
else if (c->type == DEREF)
|
|
{
|
|
struct constraint_expr tmplhs;
|
|
tmplhs = new_scalar_tmp_constraint_exp ("dereftmp");
|
|
process_constraint (new_constraint (tmplhs, *c));
|
|
c->var = tmplhs.var;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
/* Given a tree T, return the constraint expression for taking the
|
|
address of it. */
|
|
|
|
static void
|
|
get_constraint_for_address_of (tree t, VEC (ce_s, heap) **results)
|
|
{
|
|
struct constraint_expr *c;
|
|
unsigned int i;
|
|
|
|
get_constraint_for_1 (t, results, true, true);
|
|
|
|
FOR_EACH_VEC_ELT (ce_s, *results, i, c)
|
|
{
|
|
if (c->type == DEREF)
|
|
c->type = SCALAR;
|
|
else
|
|
c->type = ADDRESSOF;
|
|
}
|
|
}
|
|
|
|
/* Given a tree T, return the constraint expression for it. */
|
|
|
|
static void
|
|
get_constraint_for_1 (tree t, VEC (ce_s, heap) **results, bool address_p,
|
|
bool lhs_p)
|
|
{
|
|
struct constraint_expr temp;
|
|
|
|
/* x = integer is all glommed to a single variable, which doesn't
|
|
point to anything by itself. That is, of course, unless it is an
|
|
integer constant being treated as a pointer, in which case, we
|
|
will return that this is really the addressof anything. This
|
|
happens below, since it will fall into the default case. The only
|
|
case we know something about an integer treated like a pointer is
|
|
when it is the NULL pointer, and then we just say it points to
|
|
NULL.
|
|
|
|
Do not do that if -fno-delete-null-pointer-checks though, because
|
|
in that case *NULL does not fail, so it _should_ alias *anything.
|
|
It is not worth adding a new option or renaming the existing one,
|
|
since this case is relatively obscure. */
|
|
if ((TREE_CODE (t) == INTEGER_CST
|
|
&& integer_zerop (t))
|
|
/* The only valid CONSTRUCTORs in gimple with pointer typed
|
|
elements are zero-initializer. But in IPA mode we also
|
|
process global initializers, so verify at least. */
|
|
|| (TREE_CODE (t) == CONSTRUCTOR
|
|
&& CONSTRUCTOR_NELTS (t) == 0))
|
|
{
|
|
if (flag_delete_null_pointer_checks)
|
|
temp.var = nothing_id;
|
|
else
|
|
temp.var = nonlocal_id;
|
|
temp.type = ADDRESSOF;
|
|
temp.offset = 0;
|
|
VEC_safe_push (ce_s, heap, *results, &temp);
|
|
return;
|
|
}
|
|
|
|
/* String constants are read-only. */
|
|
if (TREE_CODE (t) == STRING_CST)
|
|
{
|
|
temp.var = readonly_id;
|
|
temp.type = SCALAR;
|
|
temp.offset = 0;
|
|
VEC_safe_push (ce_s, heap, *results, &temp);
|
|
return;
|
|
}
|
|
|
|
switch (TREE_CODE_CLASS (TREE_CODE (t)))
|
|
{
|
|
case tcc_expression:
|
|
{
|
|
switch (TREE_CODE (t))
|
|
{
|
|
case ADDR_EXPR:
|
|
get_constraint_for_address_of (TREE_OPERAND (t, 0), results);
|
|
return;
|
|
default:;
|
|
}
|
|
break;
|
|
}
|
|
case tcc_reference:
|
|
{
|
|
switch (TREE_CODE (t))
|
|
{
|
|
case MEM_REF:
|
|
{
|
|
struct constraint_expr cs;
|
|
varinfo_t vi, curr;
|
|
get_constraint_for_ptr_offset (TREE_OPERAND (t, 0),
|
|
TREE_OPERAND (t, 1), results);
|
|
do_deref (results);
|
|
|
|
/* If we are not taking the address then make sure to process
|
|
all subvariables we might access. */
|
|
if (address_p)
|
|
return;
|
|
|
|
cs = *VEC_last (ce_s, *results);
|
|
if (cs.type == DEREF)
|
|
{
|
|
/* For dereferences this means we have to defer it
|
|
to solving time. */
|
|
VEC_last (ce_s, *results)->offset = UNKNOWN_OFFSET;
|
|
return;
|
|
}
|
|
if (cs.type != SCALAR)
|
|
return;
|
|
|
|
vi = get_varinfo (cs.var);
|
|
curr = vi->next;
|
|
if (!vi->is_full_var
|
|
&& curr)
|
|
{
|
|
unsigned HOST_WIDE_INT size;
|
|
if (host_integerp (TYPE_SIZE (TREE_TYPE (t)), 1))
|
|
size = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (t)));
|
|
else
|
|
size = -1;
|
|
for (; curr; curr = curr->next)
|
|
{
|
|
if (curr->offset - vi->offset < size)
|
|
{
|
|
cs.var = curr->id;
|
|
VEC_safe_push (ce_s, heap, *results, &cs);
|
|
}
|
|
else
|
|
break;
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
case ARRAY_REF:
|
|
case ARRAY_RANGE_REF:
|
|
case COMPONENT_REF:
|
|
get_constraint_for_component_ref (t, results, address_p, lhs_p);
|
|
return;
|
|
case VIEW_CONVERT_EXPR:
|
|
get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p,
|
|
lhs_p);
|
|
return;
|
|
/* We are missing handling for TARGET_MEM_REF here. */
|
|
default:;
|
|
}
|
|
break;
|
|
}
|
|
case tcc_exceptional:
|
|
{
|
|
switch (TREE_CODE (t))
|
|
{
|
|
case SSA_NAME:
|
|
{
|
|
get_constraint_for_ssa_var (t, results, address_p);
|
|
return;
|
|
}
|
|
case CONSTRUCTOR:
|
|
{
|
|
unsigned int i;
|
|
tree val;
|
|
VEC (ce_s, heap) *tmp = NULL;
|
|
FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), i, val)
|
|
{
|
|
struct constraint_expr *rhsp;
|
|
unsigned j;
|
|
get_constraint_for_1 (val, &tmp, address_p, lhs_p);
|
|
FOR_EACH_VEC_ELT (ce_s, tmp, j, rhsp)
|
|
VEC_safe_push (ce_s, heap, *results, rhsp);
|
|
VEC_truncate (ce_s, tmp, 0);
|
|
}
|
|
VEC_free (ce_s, heap, tmp);
|
|
/* We do not know whether the constructor was complete,
|
|
so technically we have to add &NOTHING or &ANYTHING
|
|
like we do for an empty constructor as well. */
|
|
return;
|
|
}
|
|
default:;
|
|
}
|
|
break;
|
|
}
|
|
case tcc_declaration:
|
|
{
|
|
get_constraint_for_ssa_var (t, results, address_p);
|
|
return;
|
|
}
|
|
case tcc_constant:
|
|
{
|
|
/* We cannot refer to automatic variables through constants. */
|
|
temp.type = ADDRESSOF;
|
|
temp.var = nonlocal_id;
|
|
temp.offset = 0;
|
|
VEC_safe_push (ce_s, heap, *results, &temp);
|
|
return;
|
|
}
|
|
default:;
|
|
}
|
|
|
|
/* The default fallback is a constraint from anything. */
|
|
temp.type = ADDRESSOF;
|
|
temp.var = anything_id;
|
|
temp.offset = 0;
|
|
VEC_safe_push (ce_s, heap, *results, &temp);
|
|
}
|
|
|
|
/* Given a gimple tree T, return the constraint expression vector for it. */
|
|
|
|
static void
|
|
get_constraint_for (tree t, VEC (ce_s, heap) **results)
|
|
{
|
|
gcc_assert (VEC_length (ce_s, *results) == 0);
|
|
|
|
get_constraint_for_1 (t, results, false, true);
|
|
}
|
|
|
|
/* Given a gimple tree T, return the constraint expression vector for it
|
|
to be used as the rhs of a constraint. */
|
|
|
|
static void
|
|
get_constraint_for_rhs (tree t, VEC (ce_s, heap) **results)
|
|
{
|
|
gcc_assert (VEC_length (ce_s, *results) == 0);
|
|
|
|
get_constraint_for_1 (t, results, false, false);
|
|
}
|
|
|
|
|
|
/* Efficiently generates constraints from all entries in *RHSC to all
|
|
entries in *LHSC. */
|
|
|
|
static void
|
|
process_all_all_constraints (VEC (ce_s, heap) *lhsc, VEC (ce_s, heap) *rhsc)
|
|
{
|
|
struct constraint_expr *lhsp, *rhsp;
|
|
unsigned i, j;
|
|
|
|
if (VEC_length (ce_s, lhsc) <= 1
|
|
|| VEC_length (ce_s, rhsc) <= 1)
|
|
{
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, i, lhsp)
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, j, rhsp)
|
|
process_constraint (new_constraint (*lhsp, *rhsp));
|
|
}
|
|
else
|
|
{
|
|
struct constraint_expr tmp;
|
|
tmp = new_scalar_tmp_constraint_exp ("allalltmp");
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
|
|
process_constraint (new_constraint (tmp, *rhsp));
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, i, lhsp)
|
|
process_constraint (new_constraint (*lhsp, tmp));
|
|
}
|
|
}
|
|
|
|
/* Handle aggregate copies by expanding into copies of the respective
|
|
fields of the structures. */
|
|
|
|
static void
|
|
do_structure_copy (tree lhsop, tree rhsop)
|
|
{
|
|
struct constraint_expr *lhsp, *rhsp;
|
|
VEC (ce_s, heap) *lhsc = NULL, *rhsc = NULL;
|
|
unsigned j;
|
|
|
|
get_constraint_for (lhsop, &lhsc);
|
|
get_constraint_for_rhs (rhsop, &rhsc);
|
|
lhsp = VEC_index (ce_s, lhsc, 0);
|
|
rhsp = VEC_index (ce_s, rhsc, 0);
|
|
if (lhsp->type == DEREF
|
|
|| (lhsp->type == ADDRESSOF && lhsp->var == anything_id)
|
|
|| rhsp->type == DEREF)
|
|
{
|
|
if (lhsp->type == DEREF)
|
|
{
|
|
gcc_assert (VEC_length (ce_s, lhsc) == 1);
|
|
lhsp->offset = UNKNOWN_OFFSET;
|
|
}
|
|
if (rhsp->type == DEREF)
|
|
{
|
|
gcc_assert (VEC_length (ce_s, rhsc) == 1);
|
|
rhsp->offset = UNKNOWN_OFFSET;
|
|
}
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
}
|
|
else if (lhsp->type == SCALAR
|
|
&& (rhsp->type == SCALAR
|
|
|| rhsp->type == ADDRESSOF))
|
|
{
|
|
HOST_WIDE_INT lhssize, lhsmaxsize, lhsoffset;
|
|
HOST_WIDE_INT rhssize, rhsmaxsize, rhsoffset;
|
|
unsigned k = 0;
|
|
get_ref_base_and_extent (lhsop, &lhsoffset, &lhssize, &lhsmaxsize);
|
|
get_ref_base_and_extent (rhsop, &rhsoffset, &rhssize, &rhsmaxsize);
|
|
for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp);)
|
|
{
|
|
varinfo_t lhsv, rhsv;
|
|
rhsp = VEC_index (ce_s, rhsc, k);
|
|
lhsv = get_varinfo (lhsp->var);
|
|
rhsv = get_varinfo (rhsp->var);
|
|
if (lhsv->may_have_pointers
|
|
&& (lhsv->is_full_var
|
|
|| rhsv->is_full_var
|
|
|| ranges_overlap_p (lhsv->offset + rhsoffset, lhsv->size,
|
|
rhsv->offset + lhsoffset, rhsv->size)))
|
|
process_constraint (new_constraint (*lhsp, *rhsp));
|
|
if (!rhsv->is_full_var
|
|
&& (lhsv->is_full_var
|
|
|| (lhsv->offset + rhsoffset + lhsv->size
|
|
> rhsv->offset + lhsoffset + rhsv->size)))
|
|
{
|
|
++k;
|
|
if (k >= VEC_length (ce_s, rhsc))
|
|
break;
|
|
}
|
|
else
|
|
++j;
|
|
}
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
|
|
VEC_free (ce_s, heap, lhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
|
|
/* Create constraints ID = { rhsc }. */
|
|
|
|
static void
|
|
make_constraints_to (unsigned id, VEC(ce_s, heap) *rhsc)
|
|
{
|
|
struct constraint_expr *c;
|
|
struct constraint_expr includes;
|
|
unsigned int j;
|
|
|
|
includes.var = id;
|
|
includes.offset = 0;
|
|
includes.type = SCALAR;
|
|
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, j, c)
|
|
process_constraint (new_constraint (includes, *c));
|
|
}
|
|
|
|
/* Create a constraint ID = OP. */
|
|
|
|
static void
|
|
make_constraint_to (unsigned id, tree op)
|
|
{
|
|
VEC(ce_s, heap) *rhsc = NULL;
|
|
get_constraint_for_rhs (op, &rhsc);
|
|
make_constraints_to (id, rhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
|
|
/* Create a constraint ID = &FROM. */
|
|
|
|
static void
|
|
make_constraint_from (varinfo_t vi, int from)
|
|
{
|
|
struct constraint_expr lhs, rhs;
|
|
|
|
lhs.var = vi->id;
|
|
lhs.offset = 0;
|
|
lhs.type = SCALAR;
|
|
|
|
rhs.var = from;
|
|
rhs.offset = 0;
|
|
rhs.type = ADDRESSOF;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
}
|
|
|
|
/* Create a constraint ID = FROM. */
|
|
|
|
static void
|
|
make_copy_constraint (varinfo_t vi, int from)
|
|
{
|
|
struct constraint_expr lhs, rhs;
|
|
|
|
lhs.var = vi->id;
|
|
lhs.offset = 0;
|
|
lhs.type = SCALAR;
|
|
|
|
rhs.var = from;
|
|
rhs.offset = 0;
|
|
rhs.type = SCALAR;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
}
|
|
|
|
/* Make constraints necessary to make OP escape. */
|
|
|
|
static void
|
|
make_escape_constraint (tree op)
|
|
{
|
|
make_constraint_to (escaped_id, op);
|
|
}
|
|
|
|
/* Add constraints to that the solution of VI is transitively closed. */
|
|
|
|
static void
|
|
make_transitive_closure_constraints (varinfo_t vi)
|
|
{
|
|
struct constraint_expr lhs, rhs;
|
|
|
|
/* VAR = *VAR; */
|
|
lhs.type = SCALAR;
|
|
lhs.var = vi->id;
|
|
lhs.offset = 0;
|
|
rhs.type = DEREF;
|
|
rhs.var = vi->id;
|
|
rhs.offset = 0;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
|
|
/* VAR = VAR + UNKNOWN; */
|
|
lhs.type = SCALAR;
|
|
lhs.var = vi->id;
|
|
lhs.offset = 0;
|
|
rhs.type = SCALAR;
|
|
rhs.var = vi->id;
|
|
rhs.offset = UNKNOWN_OFFSET;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
}
|
|
|
|
/* Temporary storage for fake var decls. */
|
|
struct obstack fake_var_decl_obstack;
|
|
|
|
/* Build a fake VAR_DECL acting as referrer to a DECL_UID. */
|
|
|
|
static tree
|
|
build_fake_var_decl (tree type)
|
|
{
|
|
tree decl = (tree) XOBNEW (&fake_var_decl_obstack, struct tree_var_decl);
|
|
memset (decl, 0, sizeof (struct tree_var_decl));
|
|
TREE_SET_CODE (decl, VAR_DECL);
|
|
TREE_TYPE (decl) = type;
|
|
DECL_UID (decl) = allocate_decl_uid ();
|
|
SET_DECL_PT_UID (decl, -1);
|
|
layout_decl (decl, 0);
|
|
return decl;
|
|
}
|
|
|
|
/* Create a new artificial heap variable with NAME.
|
|
Return the created variable. */
|
|
|
|
static varinfo_t
|
|
make_heapvar (const char *name)
|
|
{
|
|
varinfo_t vi;
|
|
tree heapvar;
|
|
|
|
heapvar = build_fake_var_decl (ptr_type_node);
|
|
DECL_EXTERNAL (heapvar) = 1;
|
|
|
|
vi = new_var_info (heapvar, name);
|
|
vi->is_artificial_var = true;
|
|
vi->is_heap_var = true;
|
|
vi->is_unknown_size_var = true;
|
|
vi->offset = 0;
|
|
vi->fullsize = ~0;
|
|
vi->size = ~0;
|
|
vi->is_full_var = true;
|
|
insert_vi_for_tree (heapvar, vi);
|
|
|
|
return vi;
|
|
}
|
|
|
|
/* Create a new artificial heap variable with NAME and make a
|
|
constraint from it to LHS. Set flags according to a tag used
|
|
for tracking restrict pointers. */
|
|
|
|
static varinfo_t
|
|
make_constraint_from_restrict (varinfo_t lhs, const char *name)
|
|
{
|
|
varinfo_t vi = make_heapvar (name);
|
|
vi->is_global_var = 1;
|
|
vi->may_have_pointers = 1;
|
|
make_constraint_from (lhs, vi->id);
|
|
return vi;
|
|
}
|
|
|
|
/* Create a new artificial heap variable with NAME and make a
|
|
constraint from it to LHS. Set flags according to a tag used
|
|
for tracking restrict pointers and make the artificial heap
|
|
point to global memory. */
|
|
|
|
static varinfo_t
|
|
make_constraint_from_global_restrict (varinfo_t lhs, const char *name)
|
|
{
|
|
varinfo_t vi = make_constraint_from_restrict (lhs, name);
|
|
make_copy_constraint (vi, nonlocal_id);
|
|
return vi;
|
|
}
|
|
|
|
/* In IPA mode there are varinfos for different aspects of reach
|
|
function designator. One for the points-to set of the return
|
|
value, one for the variables that are clobbered by the function,
|
|
one for its uses and one for each parameter (including a single
|
|
glob for remaining variadic arguments). */
|
|
|
|
enum { fi_clobbers = 1, fi_uses = 2,
|
|
fi_static_chain = 3, fi_result = 4, fi_parm_base = 5 };
|
|
|
|
/* Get a constraint for the requested part of a function designator FI
|
|
when operating in IPA mode. */
|
|
|
|
static struct constraint_expr
|
|
get_function_part_constraint (varinfo_t fi, unsigned part)
|
|
{
|
|
struct constraint_expr c;
|
|
|
|
gcc_assert (in_ipa_mode);
|
|
|
|
if (fi->id == anything_id)
|
|
{
|
|
/* ??? We probably should have a ANYFN special variable. */
|
|
c.var = anything_id;
|
|
c.offset = 0;
|
|
c.type = SCALAR;
|
|
}
|
|
else if (TREE_CODE (fi->decl) == FUNCTION_DECL)
|
|
{
|
|
varinfo_t ai = first_vi_for_offset (fi, part);
|
|
if (ai)
|
|
c.var = ai->id;
|
|
else
|
|
c.var = anything_id;
|
|
c.offset = 0;
|
|
c.type = SCALAR;
|
|
}
|
|
else
|
|
{
|
|
c.var = fi->id;
|
|
c.offset = part;
|
|
c.type = DEREF;
|
|
}
|
|
|
|
return c;
|
|
}
|
|
|
|
/* For non-IPA mode, generate constraints necessary for a call on the
|
|
RHS. */
|
|
|
|
static void
|
|
handle_rhs_call (gimple stmt, VEC(ce_s, heap) **results)
|
|
{
|
|
struct constraint_expr rhsc;
|
|
unsigned i;
|
|
bool returns_uses = false;
|
|
|
|
for (i = 0; i < gimple_call_num_args (stmt); ++i)
|
|
{
|
|
tree arg = gimple_call_arg (stmt, i);
|
|
int flags = gimple_call_arg_flags (stmt, i);
|
|
|
|
/* If the argument is not used we can ignore it. */
|
|
if (flags & EAF_UNUSED)
|
|
continue;
|
|
|
|
/* As we compute ESCAPED context-insensitive we do not gain
|
|
any precision with just EAF_NOCLOBBER but not EAF_NOESCAPE
|
|
set. The argument would still get clobbered through the
|
|
escape solution.
|
|
??? We might get away with less (and more precise) constraints
|
|
if using a temporary for transitively closing things. */
|
|
if ((flags & EAF_NOCLOBBER)
|
|
&& (flags & EAF_NOESCAPE))
|
|
{
|
|
varinfo_t uses = get_call_use_vi (stmt);
|
|
if (!(flags & EAF_DIRECT))
|
|
make_transitive_closure_constraints (uses);
|
|
make_constraint_to (uses->id, arg);
|
|
returns_uses = true;
|
|
}
|
|
else if (flags & EAF_NOESCAPE)
|
|
{
|
|
varinfo_t uses = get_call_use_vi (stmt);
|
|
varinfo_t clobbers = get_call_clobber_vi (stmt);
|
|
if (!(flags & EAF_DIRECT))
|
|
{
|
|
make_transitive_closure_constraints (uses);
|
|
make_transitive_closure_constraints (clobbers);
|
|
}
|
|
make_constraint_to (uses->id, arg);
|
|
make_constraint_to (clobbers->id, arg);
|
|
returns_uses = true;
|
|
}
|
|
else
|
|
make_escape_constraint (arg);
|
|
}
|
|
|
|
/* If we added to the calls uses solution make sure we account for
|
|
pointers to it to be returned. */
|
|
if (returns_uses)
|
|
{
|
|
rhsc.var = get_call_use_vi (stmt)->id;
|
|
rhsc.offset = 0;
|
|
rhsc.type = SCALAR;
|
|
VEC_safe_push (ce_s, heap, *results, &rhsc);
|
|
}
|
|
|
|
/* The static chain escapes as well. */
|
|
if (gimple_call_chain (stmt))
|
|
make_escape_constraint (gimple_call_chain (stmt));
|
|
|
|
/* And if we applied NRV the address of the return slot escapes as well. */
|
|
if (gimple_call_return_slot_opt_p (stmt)
|
|
&& gimple_call_lhs (stmt) != NULL_TREE
|
|
&& TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt))))
|
|
{
|
|
VEC(ce_s, heap) *tmpc = NULL;
|
|
struct constraint_expr lhsc, *c;
|
|
get_constraint_for_address_of (gimple_call_lhs (stmt), &tmpc);
|
|
lhsc.var = escaped_id;
|
|
lhsc.offset = 0;
|
|
lhsc.type = SCALAR;
|
|
FOR_EACH_VEC_ELT (ce_s, tmpc, i, c)
|
|
process_constraint (new_constraint (lhsc, *c));
|
|
VEC_free(ce_s, heap, tmpc);
|
|
}
|
|
|
|
/* Regular functions return nonlocal memory. */
|
|
rhsc.var = nonlocal_id;
|
|
rhsc.offset = 0;
|
|
rhsc.type = SCALAR;
|
|
VEC_safe_push (ce_s, heap, *results, &rhsc);
|
|
}
|
|
|
|
/* For non-IPA mode, generate constraints necessary for a call
|
|
that returns a pointer and assigns it to LHS. This simply makes
|
|
the LHS point to global and escaped variables. */
|
|
|
|
static void
|
|
handle_lhs_call (gimple stmt, tree lhs, int flags, VEC(ce_s, heap) *rhsc,
|
|
tree fndecl)
|
|
{
|
|
VEC(ce_s, heap) *lhsc = NULL;
|
|
|
|
get_constraint_for (lhs, &lhsc);
|
|
/* If the store is to a global decl make sure to
|
|
add proper escape constraints. */
|
|
lhs = get_base_address (lhs);
|
|
if (lhs
|
|
&& DECL_P (lhs)
|
|
&& is_global_var (lhs))
|
|
{
|
|
struct constraint_expr tmpc;
|
|
tmpc.var = escaped_id;
|
|
tmpc.offset = 0;
|
|
tmpc.type = SCALAR;
|
|
VEC_safe_push (ce_s, heap, lhsc, &tmpc);
|
|
}
|
|
|
|
/* If the call returns an argument unmodified override the rhs
|
|
constraints. */
|
|
flags = gimple_call_return_flags (stmt);
|
|
if (flags & ERF_RETURNS_ARG
|
|
&& (flags & ERF_RETURN_ARG_MASK) < gimple_call_num_args (stmt))
|
|
{
|
|
tree arg;
|
|
rhsc = NULL;
|
|
arg = gimple_call_arg (stmt, flags & ERF_RETURN_ARG_MASK);
|
|
get_constraint_for (arg, &rhsc);
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
else if (flags & ERF_NOALIAS)
|
|
{
|
|
varinfo_t vi;
|
|
struct constraint_expr tmpc;
|
|
rhsc = NULL;
|
|
vi = make_heapvar ("HEAP");
|
|
/* We delay marking allocated storage global until we know if
|
|
it escapes. */
|
|
DECL_EXTERNAL (vi->decl) = 0;
|
|
vi->is_global_var = 0;
|
|
/* If this is not a real malloc call assume the memory was
|
|
initialized and thus may point to global memory. All
|
|
builtin functions with the malloc attribute behave in a sane way. */
|
|
if (!fndecl
|
|
|| DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
|
|
make_constraint_from (vi, nonlocal_id);
|
|
tmpc.var = vi->id;
|
|
tmpc.offset = 0;
|
|
tmpc.type = ADDRESSOF;
|
|
VEC_safe_push (ce_s, heap, rhsc, &tmpc);
|
|
}
|
|
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
|
|
VEC_free (ce_s, heap, lhsc);
|
|
}
|
|
|
|
/* For non-IPA mode, generate constraints necessary for a call of a
|
|
const function that returns a pointer in the statement STMT. */
|
|
|
|
static void
|
|
handle_const_call (gimple stmt, VEC(ce_s, heap) **results)
|
|
{
|
|
struct constraint_expr rhsc;
|
|
unsigned int k;
|
|
|
|
/* Treat nested const functions the same as pure functions as far
|
|
as the static chain is concerned. */
|
|
if (gimple_call_chain (stmt))
|
|
{
|
|
varinfo_t uses = get_call_use_vi (stmt);
|
|
make_transitive_closure_constraints (uses);
|
|
make_constraint_to (uses->id, gimple_call_chain (stmt));
|
|
rhsc.var = uses->id;
|
|
rhsc.offset = 0;
|
|
rhsc.type = SCALAR;
|
|
VEC_safe_push (ce_s, heap, *results, &rhsc);
|
|
}
|
|
|
|
/* May return arguments. */
|
|
for (k = 0; k < gimple_call_num_args (stmt); ++k)
|
|
{
|
|
tree arg = gimple_call_arg (stmt, k);
|
|
VEC(ce_s, heap) *argc = NULL;
|
|
unsigned i;
|
|
struct constraint_expr *argp;
|
|
get_constraint_for_rhs (arg, &argc);
|
|
FOR_EACH_VEC_ELT (ce_s, argc, i, argp)
|
|
VEC_safe_push (ce_s, heap, *results, argp);
|
|
VEC_free(ce_s, heap, argc);
|
|
}
|
|
|
|
/* May return addresses of globals. */
|
|
rhsc.var = nonlocal_id;
|
|
rhsc.offset = 0;
|
|
rhsc.type = ADDRESSOF;
|
|
VEC_safe_push (ce_s, heap, *results, &rhsc);
|
|
}
|
|
|
|
/* For non-IPA mode, generate constraints necessary for a call to a
|
|
pure function in statement STMT. */
|
|
|
|
static void
|
|
handle_pure_call (gimple stmt, VEC(ce_s, heap) **results)
|
|
{
|
|
struct constraint_expr rhsc;
|
|
unsigned i;
|
|
varinfo_t uses = NULL;
|
|
|
|
/* Memory reached from pointer arguments is call-used. */
|
|
for (i = 0; i < gimple_call_num_args (stmt); ++i)
|
|
{
|
|
tree arg = gimple_call_arg (stmt, i);
|
|
if (!uses)
|
|
{
|
|
uses = get_call_use_vi (stmt);
|
|
make_transitive_closure_constraints (uses);
|
|
}
|
|
make_constraint_to (uses->id, arg);
|
|
}
|
|
|
|
/* The static chain is used as well. */
|
|
if (gimple_call_chain (stmt))
|
|
{
|
|
if (!uses)
|
|
{
|
|
uses = get_call_use_vi (stmt);
|
|
make_transitive_closure_constraints (uses);
|
|
}
|
|
make_constraint_to (uses->id, gimple_call_chain (stmt));
|
|
}
|
|
|
|
/* Pure functions may return call-used and nonlocal memory. */
|
|
if (uses)
|
|
{
|
|
rhsc.var = uses->id;
|
|
rhsc.offset = 0;
|
|
rhsc.type = SCALAR;
|
|
VEC_safe_push (ce_s, heap, *results, &rhsc);
|
|
}
|
|
rhsc.var = nonlocal_id;
|
|
rhsc.offset = 0;
|
|
rhsc.type = SCALAR;
|
|
VEC_safe_push (ce_s, heap, *results, &rhsc);
|
|
}
|
|
|
|
|
|
/* Return the varinfo for the callee of CALL. */
|
|
|
|
static varinfo_t
|
|
get_fi_for_callee (gimple call)
|
|
{
|
|
tree decl, fn = gimple_call_fn (call);
|
|
|
|
if (fn && TREE_CODE (fn) == OBJ_TYPE_REF)
|
|
fn = OBJ_TYPE_REF_EXPR (fn);
|
|
|
|
/* If we can directly resolve the function being called, do so.
|
|
Otherwise, it must be some sort of indirect expression that
|
|
we should still be able to handle. */
|
|
decl = gimple_call_addr_fndecl (fn);
|
|
if (decl)
|
|
return get_vi_for_tree (decl);
|
|
|
|
/* If the function is anything other than a SSA name pointer we have no
|
|
clue and should be getting ANYFN (well, ANYTHING for now). */
|
|
if (!fn || TREE_CODE (fn) != SSA_NAME)
|
|
return get_varinfo (anything_id);
|
|
|
|
if ((TREE_CODE (SSA_NAME_VAR (fn)) == PARM_DECL
|
|
|| TREE_CODE (SSA_NAME_VAR (fn)) == RESULT_DECL)
|
|
&& SSA_NAME_IS_DEFAULT_DEF (fn))
|
|
fn = SSA_NAME_VAR (fn);
|
|
|
|
return get_vi_for_tree (fn);
|
|
}
|
|
|
|
/* Create constraints for the builtin call T. Return true if the call
|
|
was handled, otherwise false. */
|
|
|
|
static bool
|
|
find_func_aliases_for_builtin_call (gimple t)
|
|
{
|
|
tree fndecl = gimple_call_fndecl (t);
|
|
VEC(ce_s, heap) *lhsc = NULL;
|
|
VEC(ce_s, heap) *rhsc = NULL;
|
|
varinfo_t fi;
|
|
|
|
if (fndecl != NULL_TREE
|
|
&& DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
|
|
/* ??? All builtins that are handled here need to be handled
|
|
in the alias-oracle query functions explicitly! */
|
|
switch (DECL_FUNCTION_CODE (fndecl))
|
|
{
|
|
/* All the following functions return a pointer to the same object
|
|
as their first argument points to. The functions do not add
|
|
to the ESCAPED solution. The functions make the first argument
|
|
pointed to memory point to what the second argument pointed to
|
|
memory points to. */
|
|
case BUILT_IN_STRCPY:
|
|
case BUILT_IN_STRNCPY:
|
|
case BUILT_IN_BCOPY:
|
|
case BUILT_IN_MEMCPY:
|
|
case BUILT_IN_MEMMOVE:
|
|
case BUILT_IN_MEMPCPY:
|
|
case BUILT_IN_STPCPY:
|
|
case BUILT_IN_STPNCPY:
|
|
case BUILT_IN_STRCAT:
|
|
case BUILT_IN_STRNCAT:
|
|
case BUILT_IN_STRCPY_CHK:
|
|
case BUILT_IN_STRNCPY_CHK:
|
|
case BUILT_IN_MEMCPY_CHK:
|
|
case BUILT_IN_MEMMOVE_CHK:
|
|
case BUILT_IN_MEMPCPY_CHK:
|
|
case BUILT_IN_STPCPY_CHK:
|
|
case BUILT_IN_STRCAT_CHK:
|
|
case BUILT_IN_STRNCAT_CHK:
|
|
{
|
|
tree res = gimple_call_lhs (t);
|
|
tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
|
|
== BUILT_IN_BCOPY ? 1 : 0));
|
|
tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
|
|
== BUILT_IN_BCOPY ? 0 : 1));
|
|
if (res != NULL_TREE)
|
|
{
|
|
get_constraint_for (res, &lhsc);
|
|
if (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMPCPY
|
|
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPCPY
|
|
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPNCPY
|
|
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMPCPY_CHK
|
|
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPCPY_CHK)
|
|
get_constraint_for_ptr_offset (dest, NULL_TREE, &rhsc);
|
|
else
|
|
get_constraint_for (dest, &rhsc);
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
VEC_free (ce_s, heap, lhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
|
|
get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
|
|
do_deref (&lhsc);
|
|
do_deref (&rhsc);
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
VEC_free (ce_s, heap, lhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
return true;
|
|
}
|
|
case BUILT_IN_MEMSET:
|
|
case BUILT_IN_MEMSET_CHK:
|
|
{
|
|
tree res = gimple_call_lhs (t);
|
|
tree dest = gimple_call_arg (t, 0);
|
|
unsigned i;
|
|
ce_s *lhsp;
|
|
struct constraint_expr ac;
|
|
if (res != NULL_TREE)
|
|
{
|
|
get_constraint_for (res, &lhsc);
|
|
get_constraint_for (dest, &rhsc);
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
VEC_free (ce_s, heap, lhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
|
|
do_deref (&lhsc);
|
|
if (flag_delete_null_pointer_checks
|
|
&& integer_zerop (gimple_call_arg (t, 1)))
|
|
{
|
|
ac.type = ADDRESSOF;
|
|
ac.var = nothing_id;
|
|
}
|
|
else
|
|
{
|
|
ac.type = SCALAR;
|
|
ac.var = integer_id;
|
|
}
|
|
ac.offset = 0;
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, i, lhsp)
|
|
process_constraint (new_constraint (*lhsp, ac));
|
|
VEC_free (ce_s, heap, lhsc);
|
|
return true;
|
|
}
|
|
case BUILT_IN_ASSUME_ALIGNED:
|
|
{
|
|
tree res = gimple_call_lhs (t);
|
|
tree dest = gimple_call_arg (t, 0);
|
|
if (res != NULL_TREE)
|
|
{
|
|
get_constraint_for (res, &lhsc);
|
|
get_constraint_for (dest, &rhsc);
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
VEC_free (ce_s, heap, lhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
return true;
|
|
}
|
|
/* All the following functions do not return pointers, do not
|
|
modify the points-to sets of memory reachable from their
|
|
arguments and do not add to the ESCAPED solution. */
|
|
case BUILT_IN_SINCOS:
|
|
case BUILT_IN_SINCOSF:
|
|
case BUILT_IN_SINCOSL:
|
|
case BUILT_IN_FREXP:
|
|
case BUILT_IN_FREXPF:
|
|
case BUILT_IN_FREXPL:
|
|
case BUILT_IN_GAMMA_R:
|
|
case BUILT_IN_GAMMAF_R:
|
|
case BUILT_IN_GAMMAL_R:
|
|
case BUILT_IN_LGAMMA_R:
|
|
case BUILT_IN_LGAMMAF_R:
|
|
case BUILT_IN_LGAMMAL_R:
|
|
case BUILT_IN_MODF:
|
|
case BUILT_IN_MODFF:
|
|
case BUILT_IN_MODFL:
|
|
case BUILT_IN_REMQUO:
|
|
case BUILT_IN_REMQUOF:
|
|
case BUILT_IN_REMQUOL:
|
|
case BUILT_IN_FREE:
|
|
return true;
|
|
case BUILT_IN_STRDUP:
|
|
case BUILT_IN_STRNDUP:
|
|
if (gimple_call_lhs (t))
|
|
{
|
|
handle_lhs_call (t, gimple_call_lhs (t), gimple_call_flags (t),
|
|
NULL, fndecl);
|
|
get_constraint_for_ptr_offset (gimple_call_lhs (t),
|
|
NULL_TREE, &lhsc);
|
|
get_constraint_for_ptr_offset (gimple_call_arg (t, 0),
|
|
NULL_TREE, &rhsc);
|
|
do_deref (&lhsc);
|
|
do_deref (&rhsc);
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
VEC_free (ce_s, heap, lhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
return true;
|
|
}
|
|
break;
|
|
/* Trampolines are special - they set up passing the static
|
|
frame. */
|
|
case BUILT_IN_INIT_TRAMPOLINE:
|
|
{
|
|
tree tramp = gimple_call_arg (t, 0);
|
|
tree nfunc = gimple_call_arg (t, 1);
|
|
tree frame = gimple_call_arg (t, 2);
|
|
unsigned i;
|
|
struct constraint_expr lhs, *rhsp;
|
|
if (in_ipa_mode)
|
|
{
|
|
varinfo_t nfi = NULL;
|
|
gcc_assert (TREE_CODE (nfunc) == ADDR_EXPR);
|
|
nfi = lookup_vi_for_tree (TREE_OPERAND (nfunc, 0));
|
|
if (nfi)
|
|
{
|
|
lhs = get_function_part_constraint (nfi, fi_static_chain);
|
|
get_constraint_for (frame, &rhsc);
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
VEC_free (ce_s, heap, rhsc);
|
|
|
|
/* Make the frame point to the function for
|
|
the trampoline adjustment call. */
|
|
get_constraint_for (tramp, &lhsc);
|
|
do_deref (&lhsc);
|
|
get_constraint_for (nfunc, &rhsc);
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
VEC_free (ce_s, heap, lhsc);
|
|
|
|
return true;
|
|
}
|
|
}
|
|
/* Else fallthru to generic handling which will let
|
|
the frame escape. */
|
|
break;
|
|
}
|
|
case BUILT_IN_ADJUST_TRAMPOLINE:
|
|
{
|
|
tree tramp = gimple_call_arg (t, 0);
|
|
tree res = gimple_call_lhs (t);
|
|
if (in_ipa_mode && res)
|
|
{
|
|
get_constraint_for (res, &lhsc);
|
|
get_constraint_for (tramp, &rhsc);
|
|
do_deref (&rhsc);
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
VEC_free (ce_s, heap, lhsc);
|
|
}
|
|
return true;
|
|
}
|
|
/* Variadic argument handling needs to be handled in IPA
|
|
mode as well. */
|
|
case BUILT_IN_VA_START:
|
|
{
|
|
tree valist = gimple_call_arg (t, 0);
|
|
struct constraint_expr rhs, *lhsp;
|
|
unsigned i;
|
|
get_constraint_for (valist, &lhsc);
|
|
do_deref (&lhsc);
|
|
/* The va_list gets access to pointers in variadic
|
|
arguments. Which we know in the case of IPA analysis
|
|
and otherwise are just all nonlocal variables. */
|
|
if (in_ipa_mode)
|
|
{
|
|
fi = lookup_vi_for_tree (cfun->decl);
|
|
rhs = get_function_part_constraint (fi, ~0);
|
|
rhs.type = ADDRESSOF;
|
|
}
|
|
else
|
|
{
|
|
rhs.var = nonlocal_id;
|
|
rhs.type = ADDRESSOF;
|
|
rhs.offset = 0;
|
|
}
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, i, lhsp)
|
|
process_constraint (new_constraint (*lhsp, rhs));
|
|
VEC_free (ce_s, heap, lhsc);
|
|
/* va_list is clobbered. */
|
|
make_constraint_to (get_call_clobber_vi (t)->id, valist);
|
|
return true;
|
|
}
|
|
/* va_end doesn't have any effect that matters. */
|
|
case BUILT_IN_VA_END:
|
|
return true;
|
|
/* Alternate return. Simply give up for now. */
|
|
case BUILT_IN_RETURN:
|
|
{
|
|
fi = NULL;
|
|
if (!in_ipa_mode
|
|
|| !(fi = get_vi_for_tree (cfun->decl)))
|
|
make_constraint_from (get_varinfo (escaped_id), anything_id);
|
|
else if (in_ipa_mode
|
|
&& fi != NULL)
|
|
{
|
|
struct constraint_expr lhs, rhs;
|
|
lhs = get_function_part_constraint (fi, fi_result);
|
|
rhs.var = anything_id;
|
|
rhs.offset = 0;
|
|
rhs.type = SCALAR;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
}
|
|
return true;
|
|
}
|
|
/* printf-style functions may have hooks to set pointers to
|
|
point to somewhere into the generated string. Leave them
|
|
for a later excercise... */
|
|
default:
|
|
/* Fallthru to general call handling. */;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Create constraints for the call T. */
|
|
|
|
static void
|
|
find_func_aliases_for_call (gimple t)
|
|
{
|
|
tree fndecl = gimple_call_fndecl (t);
|
|
VEC(ce_s, heap) *lhsc = NULL;
|
|
VEC(ce_s, heap) *rhsc = NULL;
|
|
varinfo_t fi;
|
|
|
|
if (fndecl != NULL_TREE
|
|
&& DECL_BUILT_IN (fndecl)
|
|
&& find_func_aliases_for_builtin_call (t))
|
|
return;
|
|
|
|
fi = get_fi_for_callee (t);
|
|
if (!in_ipa_mode
|
|
|| (fndecl && !fi->is_fn_info))
|
|
{
|
|
VEC(ce_s, heap) *rhsc = NULL;
|
|
int flags = gimple_call_flags (t);
|
|
|
|
/* Const functions can return their arguments and addresses
|
|
of global memory but not of escaped memory. */
|
|
if (flags & (ECF_CONST|ECF_NOVOPS))
|
|
{
|
|
if (gimple_call_lhs (t))
|
|
handle_const_call (t, &rhsc);
|
|
}
|
|
/* Pure functions can return addresses in and of memory
|
|
reachable from their arguments, but they are not an escape
|
|
point for reachable memory of their arguments. */
|
|
else if (flags & (ECF_PURE|ECF_LOOPING_CONST_OR_PURE))
|
|
handle_pure_call (t, &rhsc);
|
|
else
|
|
handle_rhs_call (t, &rhsc);
|
|
if (gimple_call_lhs (t))
|
|
handle_lhs_call (t, gimple_call_lhs (t), flags, rhsc, fndecl);
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
else
|
|
{
|
|
tree lhsop;
|
|
unsigned j;
|
|
|
|
/* Assign all the passed arguments to the appropriate incoming
|
|
parameters of the function. */
|
|
for (j = 0; j < gimple_call_num_args (t); j++)
|
|
{
|
|
struct constraint_expr lhs ;
|
|
struct constraint_expr *rhsp;
|
|
tree arg = gimple_call_arg (t, j);
|
|
|
|
get_constraint_for_rhs (arg, &rhsc);
|
|
lhs = get_function_part_constraint (fi, fi_parm_base + j);
|
|
while (VEC_length (ce_s, rhsc) != 0)
|
|
{
|
|
rhsp = VEC_last (ce_s, rhsc);
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
VEC_pop (ce_s, rhsc);
|
|
}
|
|
}
|
|
|
|
/* If we are returning a value, assign it to the result. */
|
|
lhsop = gimple_call_lhs (t);
|
|
if (lhsop)
|
|
{
|
|
struct constraint_expr rhs;
|
|
struct constraint_expr *lhsp;
|
|
|
|
get_constraint_for (lhsop, &lhsc);
|
|
rhs = get_function_part_constraint (fi, fi_result);
|
|
if (fndecl
|
|
&& DECL_RESULT (fndecl)
|
|
&& DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
|
|
{
|
|
VEC(ce_s, heap) *tem = NULL;
|
|
VEC_safe_push (ce_s, heap, tem, &rhs);
|
|
do_deref (&tem);
|
|
rhs = *VEC_index (ce_s, tem, 0);
|
|
VEC_free(ce_s, heap, tem);
|
|
}
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, j, lhsp)
|
|
process_constraint (new_constraint (*lhsp, rhs));
|
|
}
|
|
|
|
/* If we pass the result decl by reference, honor that. */
|
|
if (lhsop
|
|
&& fndecl
|
|
&& DECL_RESULT (fndecl)
|
|
&& DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
|
|
{
|
|
struct constraint_expr lhs;
|
|
struct constraint_expr *rhsp;
|
|
|
|
get_constraint_for_address_of (lhsop, &rhsc);
|
|
lhs = get_function_part_constraint (fi, fi_result);
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, j, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
|
|
/* If we use a static chain, pass it along. */
|
|
if (gimple_call_chain (t))
|
|
{
|
|
struct constraint_expr lhs;
|
|
struct constraint_expr *rhsp;
|
|
|
|
get_constraint_for (gimple_call_chain (t), &rhsc);
|
|
lhs = get_function_part_constraint (fi, fi_static_chain);
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, j, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Walk statement T setting up aliasing constraints according to the
|
|
references found in T. This function is the main part of the
|
|
constraint builder. AI points to auxiliary alias information used
|
|
when building alias sets and computing alias grouping heuristics. */
|
|
|
|
static void
|
|
find_func_aliases (gimple origt)
|
|
{
|
|
gimple t = origt;
|
|
VEC(ce_s, heap) *lhsc = NULL;
|
|
VEC(ce_s, heap) *rhsc = NULL;
|
|
struct constraint_expr *c;
|
|
varinfo_t fi;
|
|
|
|
/* Now build constraints expressions. */
|
|
if (gimple_code (t) == GIMPLE_PHI)
|
|
{
|
|
size_t i;
|
|
unsigned int j;
|
|
|
|
/* For a phi node, assign all the arguments to
|
|
the result. */
|
|
get_constraint_for (gimple_phi_result (t), &lhsc);
|
|
for (i = 0; i < gimple_phi_num_args (t); i++)
|
|
{
|
|
tree strippedrhs = PHI_ARG_DEF (t, i);
|
|
|
|
STRIP_NOPS (strippedrhs);
|
|
get_constraint_for_rhs (gimple_phi_arg_def (t, i), &rhsc);
|
|
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, j, c)
|
|
{
|
|
struct constraint_expr *c2;
|
|
while (VEC_length (ce_s, rhsc) > 0)
|
|
{
|
|
c2 = VEC_last (ce_s, rhsc);
|
|
process_constraint (new_constraint (*c, *c2));
|
|
VEC_pop (ce_s, rhsc);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
/* In IPA mode, we need to generate constraints to pass call
|
|
arguments through their calls. There are two cases,
|
|
either a GIMPLE_CALL returning a value, or just a plain
|
|
GIMPLE_CALL when we are not.
|
|
|
|
In non-ipa mode, we need to generate constraints for each
|
|
pointer passed by address. */
|
|
else if (is_gimple_call (t))
|
|
find_func_aliases_for_call (t);
|
|
|
|
/* Otherwise, just a regular assignment statement. Only care about
|
|
operations with pointer result, others are dealt with as escape
|
|
points if they have pointer operands. */
|
|
else if (is_gimple_assign (t))
|
|
{
|
|
/* Otherwise, just a regular assignment statement. */
|
|
tree lhsop = gimple_assign_lhs (t);
|
|
tree rhsop = (gimple_num_ops (t) == 2) ? gimple_assign_rhs1 (t) : NULL;
|
|
|
|
if (rhsop && AGGREGATE_TYPE_P (TREE_TYPE (lhsop)))
|
|
do_structure_copy (lhsop, rhsop);
|
|
else
|
|
{
|
|
enum tree_code code = gimple_assign_rhs_code (t);
|
|
|
|
get_constraint_for (lhsop, &lhsc);
|
|
|
|
if (code == POINTER_PLUS_EXPR)
|
|
get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
|
|
gimple_assign_rhs2 (t), &rhsc);
|
|
else if (code == BIT_AND_EXPR
|
|
&& TREE_CODE (gimple_assign_rhs2 (t)) == INTEGER_CST)
|
|
{
|
|
/* Aligning a pointer via a BIT_AND_EXPR is offsetting
|
|
the pointer. Handle it by offsetting it by UNKNOWN. */
|
|
get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
|
|
NULL_TREE, &rhsc);
|
|
}
|
|
else if ((CONVERT_EXPR_CODE_P (code)
|
|
&& !(POINTER_TYPE_P (gimple_expr_type (t))
|
|
&& !POINTER_TYPE_P (TREE_TYPE (rhsop))))
|
|
|| gimple_assign_single_p (t))
|
|
get_constraint_for_rhs (rhsop, &rhsc);
|
|
else if (truth_value_p (code))
|
|
/* Truth value results are not pointer (parts). Or at least
|
|
very very unreasonable obfuscation of a part. */
|
|
;
|
|
else
|
|
{
|
|
/* All other operations are merges. */
|
|
VEC (ce_s, heap) *tmp = NULL;
|
|
struct constraint_expr *rhsp;
|
|
unsigned i, j;
|
|
get_constraint_for_rhs (gimple_assign_rhs1 (t), &rhsc);
|
|
for (i = 2; i < gimple_num_ops (t); ++i)
|
|
{
|
|
get_constraint_for_rhs (gimple_op (t, i), &tmp);
|
|
FOR_EACH_VEC_ELT (ce_s, tmp, j, rhsp)
|
|
VEC_safe_push (ce_s, heap, rhsc, rhsp);
|
|
VEC_truncate (ce_s, tmp, 0);
|
|
}
|
|
VEC_free (ce_s, heap, tmp);
|
|
}
|
|
process_all_all_constraints (lhsc, rhsc);
|
|
}
|
|
/* If there is a store to a global variable the rhs escapes. */
|
|
if ((lhsop = get_base_address (lhsop)) != NULL_TREE
|
|
&& DECL_P (lhsop)
|
|
&& is_global_var (lhsop)
|
|
&& (!in_ipa_mode
|
|
|| DECL_EXTERNAL (lhsop) || TREE_PUBLIC (lhsop)))
|
|
make_escape_constraint (rhsop);
|
|
}
|
|
/* Handle escapes through return. */
|
|
else if (gimple_code (t) == GIMPLE_RETURN
|
|
&& gimple_return_retval (t) != NULL_TREE)
|
|
{
|
|
fi = NULL;
|
|
if (!in_ipa_mode
|
|
|| !(fi = get_vi_for_tree (cfun->decl)))
|
|
make_escape_constraint (gimple_return_retval (t));
|
|
else if (in_ipa_mode
|
|
&& fi != NULL)
|
|
{
|
|
struct constraint_expr lhs ;
|
|
struct constraint_expr *rhsp;
|
|
unsigned i;
|
|
|
|
lhs = get_function_part_constraint (fi, fi_result);
|
|
get_constraint_for_rhs (gimple_return_retval (t), &rhsc);
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
}
|
|
}
|
|
/* Handle asms conservatively by adding escape constraints to everything. */
|
|
else if (gimple_code (t) == GIMPLE_ASM)
|
|
{
|
|
unsigned i, noutputs;
|
|
const char **oconstraints;
|
|
const char *constraint;
|
|
bool allows_mem, allows_reg, is_inout;
|
|
|
|
noutputs = gimple_asm_noutputs (t);
|
|
oconstraints = XALLOCAVEC (const char *, noutputs);
|
|
|
|
for (i = 0; i < noutputs; ++i)
|
|
{
|
|
tree link = gimple_asm_output_op (t, i);
|
|
tree op = TREE_VALUE (link);
|
|
|
|
constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
|
|
oconstraints[i] = constraint;
|
|
parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
|
|
&allows_reg, &is_inout);
|
|
|
|
/* A memory constraint makes the address of the operand escape. */
|
|
if (!allows_reg && allows_mem)
|
|
make_escape_constraint (build_fold_addr_expr (op));
|
|
|
|
/* The asm may read global memory, so outputs may point to
|
|
any global memory. */
|
|
if (op)
|
|
{
|
|
VEC(ce_s, heap) *lhsc = NULL;
|
|
struct constraint_expr rhsc, *lhsp;
|
|
unsigned j;
|
|
get_constraint_for (op, &lhsc);
|
|
rhsc.var = nonlocal_id;
|
|
rhsc.offset = 0;
|
|
rhsc.type = SCALAR;
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, j, lhsp)
|
|
process_constraint (new_constraint (*lhsp, rhsc));
|
|
VEC_free (ce_s, heap, lhsc);
|
|
}
|
|
}
|
|
for (i = 0; i < gimple_asm_ninputs (t); ++i)
|
|
{
|
|
tree link = gimple_asm_input_op (t, i);
|
|
tree op = TREE_VALUE (link);
|
|
|
|
constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
|
|
|
|
parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints,
|
|
&allows_mem, &allows_reg);
|
|
|
|
/* A memory constraint makes the address of the operand escape. */
|
|
if (!allows_reg && allows_mem)
|
|
make_escape_constraint (build_fold_addr_expr (op));
|
|
/* Strictly we'd only need the constraint to ESCAPED if
|
|
the asm clobbers memory, otherwise using something
|
|
along the lines of per-call clobbers/uses would be enough. */
|
|
else if (op)
|
|
make_escape_constraint (op);
|
|
}
|
|
}
|
|
|
|
VEC_free (ce_s, heap, rhsc);
|
|
VEC_free (ce_s, heap, lhsc);
|
|
}
|
|
|
|
|
|
/* Create a constraint adding to the clobber set of FI the memory
|
|
pointed to by PTR. */
|
|
|
|
static void
|
|
process_ipa_clobber (varinfo_t fi, tree ptr)
|
|
{
|
|
VEC(ce_s, heap) *ptrc = NULL;
|
|
struct constraint_expr *c, lhs;
|
|
unsigned i;
|
|
get_constraint_for_rhs (ptr, &ptrc);
|
|
lhs = get_function_part_constraint (fi, fi_clobbers);
|
|
FOR_EACH_VEC_ELT (ce_s, ptrc, i, c)
|
|
process_constraint (new_constraint (lhs, *c));
|
|
VEC_free (ce_s, heap, ptrc);
|
|
}
|
|
|
|
/* Walk statement T setting up clobber and use constraints according to the
|
|
references found in T. This function is a main part of the
|
|
IPA constraint builder. */
|
|
|
|
static void
|
|
find_func_clobbers (gimple origt)
|
|
{
|
|
gimple t = origt;
|
|
VEC(ce_s, heap) *lhsc = NULL;
|
|
VEC(ce_s, heap) *rhsc = NULL;
|
|
varinfo_t fi;
|
|
|
|
/* Add constraints for clobbered/used in IPA mode.
|
|
We are not interested in what automatic variables are clobbered
|
|
or used as we only use the information in the caller to which
|
|
they do not escape. */
|
|
gcc_assert (in_ipa_mode);
|
|
|
|
/* If the stmt refers to memory in any way it better had a VUSE. */
|
|
if (gimple_vuse (t) == NULL_TREE)
|
|
return;
|
|
|
|
/* We'd better have function information for the current function. */
|
|
fi = lookup_vi_for_tree (cfun->decl);
|
|
gcc_assert (fi != NULL);
|
|
|
|
/* Account for stores in assignments and calls. */
|
|
if (gimple_vdef (t) != NULL_TREE
|
|
&& gimple_has_lhs (t))
|
|
{
|
|
tree lhs = gimple_get_lhs (t);
|
|
tree tem = lhs;
|
|
while (handled_component_p (tem))
|
|
tem = TREE_OPERAND (tem, 0);
|
|
if ((DECL_P (tem)
|
|
&& !auto_var_in_fn_p (tem, cfun->decl))
|
|
|| INDIRECT_REF_P (tem)
|
|
|| (TREE_CODE (tem) == MEM_REF
|
|
&& !(TREE_CODE (TREE_OPERAND (tem, 0)) == ADDR_EXPR
|
|
&& auto_var_in_fn_p
|
|
(TREE_OPERAND (TREE_OPERAND (tem, 0), 0), cfun->decl))))
|
|
{
|
|
struct constraint_expr lhsc, *rhsp;
|
|
unsigned i;
|
|
lhsc = get_function_part_constraint (fi, fi_clobbers);
|
|
get_constraint_for_address_of (lhs, &rhsc);
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
|
|
process_constraint (new_constraint (lhsc, *rhsp));
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
}
|
|
|
|
/* Account for uses in assigments and returns. */
|
|
if (gimple_assign_single_p (t)
|
|
|| (gimple_code (t) == GIMPLE_RETURN
|
|
&& gimple_return_retval (t) != NULL_TREE))
|
|
{
|
|
tree rhs = (gimple_assign_single_p (t)
|
|
? gimple_assign_rhs1 (t) : gimple_return_retval (t));
|
|
tree tem = rhs;
|
|
while (handled_component_p (tem))
|
|
tem = TREE_OPERAND (tem, 0);
|
|
if ((DECL_P (tem)
|
|
&& !auto_var_in_fn_p (tem, cfun->decl))
|
|
|| INDIRECT_REF_P (tem)
|
|
|| (TREE_CODE (tem) == MEM_REF
|
|
&& !(TREE_CODE (TREE_OPERAND (tem, 0)) == ADDR_EXPR
|
|
&& auto_var_in_fn_p
|
|
(TREE_OPERAND (TREE_OPERAND (tem, 0), 0), cfun->decl))))
|
|
{
|
|
struct constraint_expr lhs, *rhsp;
|
|
unsigned i;
|
|
lhs = get_function_part_constraint (fi, fi_uses);
|
|
get_constraint_for_address_of (rhs, &rhsc);
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
}
|
|
|
|
if (is_gimple_call (t))
|
|
{
|
|
varinfo_t cfi = NULL;
|
|
tree decl = gimple_call_fndecl (t);
|
|
struct constraint_expr lhs, rhs;
|
|
unsigned i, j;
|
|
|
|
/* For builtins we do not have separate function info. For those
|
|
we do not generate escapes for we have to generate clobbers/uses. */
|
|
if (decl
|
|
&& DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
|
|
switch (DECL_FUNCTION_CODE (decl))
|
|
{
|
|
/* The following functions use and clobber memory pointed to
|
|
by their arguments. */
|
|
case BUILT_IN_STRCPY:
|
|
case BUILT_IN_STRNCPY:
|
|
case BUILT_IN_BCOPY:
|
|
case BUILT_IN_MEMCPY:
|
|
case BUILT_IN_MEMMOVE:
|
|
case BUILT_IN_MEMPCPY:
|
|
case BUILT_IN_STPCPY:
|
|
case BUILT_IN_STPNCPY:
|
|
case BUILT_IN_STRCAT:
|
|
case BUILT_IN_STRNCAT:
|
|
case BUILT_IN_STRCPY_CHK:
|
|
case BUILT_IN_STRNCPY_CHK:
|
|
case BUILT_IN_MEMCPY_CHK:
|
|
case BUILT_IN_MEMMOVE_CHK:
|
|
case BUILT_IN_MEMPCPY_CHK:
|
|
case BUILT_IN_STPCPY_CHK:
|
|
case BUILT_IN_STRCAT_CHK:
|
|
case BUILT_IN_STRNCAT_CHK:
|
|
{
|
|
tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
|
|
== BUILT_IN_BCOPY ? 1 : 0));
|
|
tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
|
|
== BUILT_IN_BCOPY ? 0 : 1));
|
|
unsigned i;
|
|
struct constraint_expr *rhsp, *lhsp;
|
|
get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
|
|
lhs = get_function_part_constraint (fi, fi_clobbers);
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, i, lhsp)
|
|
process_constraint (new_constraint (lhs, *lhsp));
|
|
VEC_free (ce_s, heap, lhsc);
|
|
get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
|
|
lhs = get_function_part_constraint (fi, fi_uses);
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
VEC_free (ce_s, heap, rhsc);
|
|
return;
|
|
}
|
|
/* The following function clobbers memory pointed to by
|
|
its argument. */
|
|
case BUILT_IN_MEMSET:
|
|
case BUILT_IN_MEMSET_CHK:
|
|
{
|
|
tree dest = gimple_call_arg (t, 0);
|
|
unsigned i;
|
|
ce_s *lhsp;
|
|
get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
|
|
lhs = get_function_part_constraint (fi, fi_clobbers);
|
|
FOR_EACH_VEC_ELT (ce_s, lhsc, i, lhsp)
|
|
process_constraint (new_constraint (lhs, *lhsp));
|
|
VEC_free (ce_s, heap, lhsc);
|
|
return;
|
|
}
|
|
/* The following functions clobber their second and third
|
|
arguments. */
|
|
case BUILT_IN_SINCOS:
|
|
case BUILT_IN_SINCOSF:
|
|
case BUILT_IN_SINCOSL:
|
|
{
|
|
process_ipa_clobber (fi, gimple_call_arg (t, 1));
|
|
process_ipa_clobber (fi, gimple_call_arg (t, 2));
|
|
return;
|
|
}
|
|
/* The following functions clobber their second argument. */
|
|
case BUILT_IN_FREXP:
|
|
case BUILT_IN_FREXPF:
|
|
case BUILT_IN_FREXPL:
|
|
case BUILT_IN_LGAMMA_R:
|
|
case BUILT_IN_LGAMMAF_R:
|
|
case BUILT_IN_LGAMMAL_R:
|
|
case BUILT_IN_GAMMA_R:
|
|
case BUILT_IN_GAMMAF_R:
|
|
case BUILT_IN_GAMMAL_R:
|
|
case BUILT_IN_MODF:
|
|
case BUILT_IN_MODFF:
|
|
case BUILT_IN_MODFL:
|
|
{
|
|
process_ipa_clobber (fi, gimple_call_arg (t, 1));
|
|
return;
|
|
}
|
|
/* The following functions clobber their third argument. */
|
|
case BUILT_IN_REMQUO:
|
|
case BUILT_IN_REMQUOF:
|
|
case BUILT_IN_REMQUOL:
|
|
{
|
|
process_ipa_clobber (fi, gimple_call_arg (t, 2));
|
|
return;
|
|
}
|
|
/* The following functions neither read nor clobber memory. */
|
|
case BUILT_IN_ASSUME_ALIGNED:
|
|
case BUILT_IN_FREE:
|
|
return;
|
|
/* Trampolines are of no interest to us. */
|
|
case BUILT_IN_INIT_TRAMPOLINE:
|
|
case BUILT_IN_ADJUST_TRAMPOLINE:
|
|
return;
|
|
case BUILT_IN_VA_START:
|
|
case BUILT_IN_VA_END:
|
|
return;
|
|
/* printf-style functions may have hooks to set pointers to
|
|
point to somewhere into the generated string. Leave them
|
|
for a later excercise... */
|
|
default:
|
|
/* Fallthru to general call handling. */;
|
|
}
|
|
|
|
/* Parameters passed by value are used. */
|
|
lhs = get_function_part_constraint (fi, fi_uses);
|
|
for (i = 0; i < gimple_call_num_args (t); i++)
|
|
{
|
|
struct constraint_expr *rhsp;
|
|
tree arg = gimple_call_arg (t, i);
|
|
|
|
if (TREE_CODE (arg) == SSA_NAME
|
|
|| is_gimple_min_invariant (arg))
|
|
continue;
|
|
|
|
get_constraint_for_address_of (arg, &rhsc);
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, j, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
|
|
/* Build constraints for propagating clobbers/uses along the
|
|
callgraph edges. */
|
|
cfi = get_fi_for_callee (t);
|
|
if (cfi->id == anything_id)
|
|
{
|
|
if (gimple_vdef (t))
|
|
make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
|
|
anything_id);
|
|
make_constraint_from (first_vi_for_offset (fi, fi_uses),
|
|
anything_id);
|
|
return;
|
|
}
|
|
|
|
/* For callees without function info (that's external functions),
|
|
ESCAPED is clobbered and used. */
|
|
if (gimple_call_fndecl (t)
|
|
&& !cfi->is_fn_info)
|
|
{
|
|
varinfo_t vi;
|
|
|
|
if (gimple_vdef (t))
|
|
make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
|
|
escaped_id);
|
|
make_copy_constraint (first_vi_for_offset (fi, fi_uses), escaped_id);
|
|
|
|
/* Also honor the call statement use/clobber info. */
|
|
if ((vi = lookup_call_clobber_vi (t)) != NULL)
|
|
make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
|
|
vi->id);
|
|
if ((vi = lookup_call_use_vi (t)) != NULL)
|
|
make_copy_constraint (first_vi_for_offset (fi, fi_uses),
|
|
vi->id);
|
|
return;
|
|
}
|
|
|
|
/* Otherwise the caller clobbers and uses what the callee does.
|
|
??? This should use a new complex constraint that filters
|
|
local variables of the callee. */
|
|
if (gimple_vdef (t))
|
|
{
|
|
lhs = get_function_part_constraint (fi, fi_clobbers);
|
|
rhs = get_function_part_constraint (cfi, fi_clobbers);
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
}
|
|
lhs = get_function_part_constraint (fi, fi_uses);
|
|
rhs = get_function_part_constraint (cfi, fi_uses);
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
}
|
|
else if (gimple_code (t) == GIMPLE_ASM)
|
|
{
|
|
/* ??? Ick. We can do better. */
|
|
if (gimple_vdef (t))
|
|
make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
|
|
anything_id);
|
|
make_constraint_from (first_vi_for_offset (fi, fi_uses),
|
|
anything_id);
|
|
}
|
|
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
|
|
|
|
/* Find the first varinfo in the same variable as START that overlaps with
|
|
OFFSET. Return NULL if we can't find one. */
|
|
|
|
static varinfo_t
|
|
first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
|
|
{
|
|
/* If the offset is outside of the variable, bail out. */
|
|
if (offset >= start->fullsize)
|
|
return NULL;
|
|
|
|
/* If we cannot reach offset from start, lookup the first field
|
|
and start from there. */
|
|
if (start->offset > offset)
|
|
start = lookup_vi_for_tree (start->decl);
|
|
|
|
while (start)
|
|
{
|
|
/* We may not find a variable in the field list with the actual
|
|
offset when when we have glommed a structure to a variable.
|
|
In that case, however, offset should still be within the size
|
|
of the variable. */
|
|
if (offset >= start->offset
|
|
&& (offset - start->offset) < start->size)
|
|
return start;
|
|
|
|
start= start->next;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Find the first varinfo in the same variable as START that overlaps with
|
|
OFFSET. If there is no such varinfo the varinfo directly preceding
|
|
OFFSET is returned. */
|
|
|
|
static varinfo_t
|
|
first_or_preceding_vi_for_offset (varinfo_t start,
|
|
unsigned HOST_WIDE_INT offset)
|
|
{
|
|
/* If we cannot reach offset from start, lookup the first field
|
|
and start from there. */
|
|
if (start->offset > offset)
|
|
start = lookup_vi_for_tree (start->decl);
|
|
|
|
/* We may not find a variable in the field list with the actual
|
|
offset when when we have glommed a structure to a variable.
|
|
In that case, however, offset should still be within the size
|
|
of the variable.
|
|
If we got beyond the offset we look for return the field
|
|
directly preceding offset which may be the last field. */
|
|
while (start->next
|
|
&& offset >= start->offset
|
|
&& !((offset - start->offset) < start->size))
|
|
start = start->next;
|
|
|
|
return start;
|
|
}
|
|
|
|
|
|
/* This structure is used during pushing fields onto the fieldstack
|
|
to track the offset of the field, since bitpos_of_field gives it
|
|
relative to its immediate containing type, and we want it relative
|
|
to the ultimate containing object. */
|
|
|
|
struct fieldoff
|
|
{
|
|
/* Offset from the base of the base containing object to this field. */
|
|
HOST_WIDE_INT offset;
|
|
|
|
/* Size, in bits, of the field. */
|
|
unsigned HOST_WIDE_INT size;
|
|
|
|
unsigned has_unknown_size : 1;
|
|
|
|
unsigned must_have_pointers : 1;
|
|
|
|
unsigned may_have_pointers : 1;
|
|
|
|
unsigned only_restrict_pointers : 1;
|
|
};
|
|
typedef struct fieldoff fieldoff_s;
|
|
|
|
DEF_VEC_O(fieldoff_s);
|
|
DEF_VEC_ALLOC_O(fieldoff_s,heap);
|
|
|
|
/* qsort comparison function for two fieldoff's PA and PB */
|
|
|
|
static int
|
|
fieldoff_compare (const void *pa, const void *pb)
|
|
{
|
|
const fieldoff_s *foa = (const fieldoff_s *)pa;
|
|
const fieldoff_s *fob = (const fieldoff_s *)pb;
|
|
unsigned HOST_WIDE_INT foasize, fobsize;
|
|
|
|
if (foa->offset < fob->offset)
|
|
return -1;
|
|
else if (foa->offset > fob->offset)
|
|
return 1;
|
|
|
|
foasize = foa->size;
|
|
fobsize = fob->size;
|
|
if (foasize < fobsize)
|
|
return -1;
|
|
else if (foasize > fobsize)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/* Sort a fieldstack according to the field offset and sizes. */
|
|
static void
|
|
sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
|
|
{
|
|
VEC_qsort (fieldoff_s, fieldstack, fieldoff_compare);
|
|
}
|
|
|
|
/* Return true if V is a tree that we can have subvars for.
|
|
Normally, this is any aggregate type. Also complex
|
|
types which are not gimple registers can have subvars. */
|
|
|
|
static inline bool
|
|
var_can_have_subvars (const_tree v)
|
|
{
|
|
/* Volatile variables should never have subvars. */
|
|
if (TREE_THIS_VOLATILE (v))
|
|
return false;
|
|
|
|
/* Non decls or memory tags can never have subvars. */
|
|
if (!DECL_P (v))
|
|
return false;
|
|
|
|
/* Aggregates without overlapping fields can have subvars. */
|
|
if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Return true if T is a type that does contain pointers. */
|
|
|
|
static bool
|
|
type_must_have_pointers (tree type)
|
|
{
|
|
if (POINTER_TYPE_P (type))
|
|
return true;
|
|
|
|
if (TREE_CODE (type) == ARRAY_TYPE)
|
|
return type_must_have_pointers (TREE_TYPE (type));
|
|
|
|
/* A function or method can have pointers as arguments, so track
|
|
those separately. */
|
|
if (TREE_CODE (type) == FUNCTION_TYPE
|
|
|| TREE_CODE (type) == METHOD_TYPE)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool
|
|
field_must_have_pointers (tree t)
|
|
{
|
|
return type_must_have_pointers (TREE_TYPE (t));
|
|
}
|
|
|
|
/* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
|
|
the fields of TYPE onto fieldstack, recording their offsets along
|
|
the way.
|
|
|
|
OFFSET is used to keep track of the offset in this entire
|
|
structure, rather than just the immediately containing structure.
|
|
Returns false if the caller is supposed to handle the field we
|
|
recursed for. */
|
|
|
|
static bool
|
|
push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
|
|
HOST_WIDE_INT offset)
|
|
{
|
|
tree field;
|
|
bool empty_p = true;
|
|
|
|
if (TREE_CODE (type) != RECORD_TYPE)
|
|
return false;
|
|
|
|
/* If the vector of fields is growing too big, bail out early.
|
|
Callers check for VEC_length <= MAX_FIELDS_FOR_FIELD_SENSITIVE, make
|
|
sure this fails. */
|
|
if (VEC_length (fieldoff_s, *fieldstack) > MAX_FIELDS_FOR_FIELD_SENSITIVE)
|
|
return false;
|
|
|
|
for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
|
|
if (TREE_CODE (field) == FIELD_DECL)
|
|
{
|
|
bool push = false;
|
|
HOST_WIDE_INT foff = bitpos_of_field (field);
|
|
|
|
if (!var_can_have_subvars (field)
|
|
|| TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE
|
|
|| TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
|
|
push = true;
|
|
else if (!push_fields_onto_fieldstack
|
|
(TREE_TYPE (field), fieldstack, offset + foff)
|
|
&& (DECL_SIZE (field)
|
|
&& !integer_zerop (DECL_SIZE (field))))
|
|
/* Empty structures may have actual size, like in C++. So
|
|
see if we didn't push any subfields and the size is
|
|
nonzero, push the field onto the stack. */
|
|
push = true;
|
|
|
|
if (push)
|
|
{
|
|
fieldoff_s *pair = NULL;
|
|
bool has_unknown_size = false;
|
|
bool must_have_pointers_p;
|
|
|
|
if (!VEC_empty (fieldoff_s, *fieldstack))
|
|
pair = VEC_last (fieldoff_s, *fieldstack);
|
|
|
|
/* If there isn't anything at offset zero, create sth. */
|
|
if (!pair
|
|
&& offset + foff != 0)
|
|
{
|
|
pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
|
|
pair->offset = 0;
|
|
pair->size = offset + foff;
|
|
pair->has_unknown_size = false;
|
|
pair->must_have_pointers = false;
|
|
pair->may_have_pointers = false;
|
|
pair->only_restrict_pointers = false;
|
|
}
|
|
|
|
if (!DECL_SIZE (field)
|
|
|| !host_integerp (DECL_SIZE (field), 1))
|
|
has_unknown_size = true;
|
|
|
|
/* If adjacent fields do not contain pointers merge them. */
|
|
must_have_pointers_p = field_must_have_pointers (field);
|
|
if (pair
|
|
&& !has_unknown_size
|
|
&& !must_have_pointers_p
|
|
&& !pair->must_have_pointers
|
|
&& !pair->has_unknown_size
|
|
&& pair->offset + (HOST_WIDE_INT)pair->size == offset + foff)
|
|
{
|
|
pair->size += TREE_INT_CST_LOW (DECL_SIZE (field));
|
|
}
|
|
else
|
|
{
|
|
pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
|
|
pair->offset = offset + foff;
|
|
pair->has_unknown_size = has_unknown_size;
|
|
if (!has_unknown_size)
|
|
pair->size = TREE_INT_CST_LOW (DECL_SIZE (field));
|
|
else
|
|
pair->size = -1;
|
|
pair->must_have_pointers = must_have_pointers_p;
|
|
pair->may_have_pointers = true;
|
|
pair->only_restrict_pointers
|
|
= (!has_unknown_size
|
|
&& POINTER_TYPE_P (TREE_TYPE (field))
|
|
&& TYPE_RESTRICT (TREE_TYPE (field)));
|
|
}
|
|
}
|
|
|
|
empty_p = false;
|
|
}
|
|
|
|
return !empty_p;
|
|
}
|
|
|
|
/* Count the number of arguments DECL has, and set IS_VARARGS to true
|
|
if it is a varargs function. */
|
|
|
|
static unsigned int
|
|
count_num_arguments (tree decl, bool *is_varargs)
|
|
{
|
|
unsigned int num = 0;
|
|
tree t;
|
|
|
|
/* Capture named arguments for K&R functions. They do not
|
|
have a prototype and thus no TYPE_ARG_TYPES. */
|
|
for (t = DECL_ARGUMENTS (decl); t; t = DECL_CHAIN (t))
|
|
++num;
|
|
|
|
/* Check if the function has variadic arguments. */
|
|
for (t = TYPE_ARG_TYPES (TREE_TYPE (decl)); t; t = TREE_CHAIN (t))
|
|
if (TREE_VALUE (t) == void_type_node)
|
|
break;
|
|
if (!t)
|
|
*is_varargs = true;
|
|
|
|
return num;
|
|
}
|
|
|
|
/* Creation function node for DECL, using NAME, and return the index
|
|
of the variable we've created for the function. */
|
|
|
|
static varinfo_t
|
|
create_function_info_for (tree decl, const char *name)
|
|
{
|
|
struct function *fn = DECL_STRUCT_FUNCTION (decl);
|
|
varinfo_t vi, prev_vi;
|
|
tree arg;
|
|
unsigned int i;
|
|
bool is_varargs = false;
|
|
unsigned int num_args = count_num_arguments (decl, &is_varargs);
|
|
|
|
/* Create the variable info. */
|
|
|
|
vi = new_var_info (decl, name);
|
|
vi->offset = 0;
|
|
vi->size = 1;
|
|
vi->fullsize = fi_parm_base + num_args;
|
|
vi->is_fn_info = 1;
|
|
vi->may_have_pointers = false;
|
|
if (is_varargs)
|
|
vi->fullsize = ~0;
|
|
insert_vi_for_tree (vi->decl, vi);
|
|
|
|
prev_vi = vi;
|
|
|
|
/* Create a variable for things the function clobbers and one for
|
|
things the function uses. */
|
|
{
|
|
varinfo_t clobbervi, usevi;
|
|
const char *newname;
|
|
char *tempname;
|
|
|
|
asprintf (&tempname, "%s.clobber", name);
|
|
newname = ggc_strdup (tempname);
|
|
free (tempname);
|
|
|
|
clobbervi = new_var_info (NULL, newname);
|
|
clobbervi->offset = fi_clobbers;
|
|
clobbervi->size = 1;
|
|
clobbervi->fullsize = vi->fullsize;
|
|
clobbervi->is_full_var = true;
|
|
clobbervi->is_global_var = false;
|
|
gcc_assert (prev_vi->offset < clobbervi->offset);
|
|
prev_vi->next = clobbervi;
|
|
prev_vi = clobbervi;
|
|
|
|
asprintf (&tempname, "%s.use", name);
|
|
newname = ggc_strdup (tempname);
|
|
free (tempname);
|
|
|
|
usevi = new_var_info (NULL, newname);
|
|
usevi->offset = fi_uses;
|
|
usevi->size = 1;
|
|
usevi->fullsize = vi->fullsize;
|
|
usevi->is_full_var = true;
|
|
usevi->is_global_var = false;
|
|
gcc_assert (prev_vi->offset < usevi->offset);
|
|
prev_vi->next = usevi;
|
|
prev_vi = usevi;
|
|
}
|
|
|
|
/* And one for the static chain. */
|
|
if (fn->static_chain_decl != NULL_TREE)
|
|
{
|
|
varinfo_t chainvi;
|
|
const char *newname;
|
|
char *tempname;
|
|
|
|
asprintf (&tempname, "%s.chain", name);
|
|
newname = ggc_strdup (tempname);
|
|
free (tempname);
|
|
|
|
chainvi = new_var_info (fn->static_chain_decl, newname);
|
|
chainvi->offset = fi_static_chain;
|
|
chainvi->size = 1;
|
|
chainvi->fullsize = vi->fullsize;
|
|
chainvi->is_full_var = true;
|
|
chainvi->is_global_var = false;
|
|
gcc_assert (prev_vi->offset < chainvi->offset);
|
|
prev_vi->next = chainvi;
|
|
prev_vi = chainvi;
|
|
insert_vi_for_tree (fn->static_chain_decl, chainvi);
|
|
}
|
|
|
|
/* Create a variable for the return var. */
|
|
if (DECL_RESULT (decl) != NULL
|
|
|| !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
|
|
{
|
|
varinfo_t resultvi;
|
|
const char *newname;
|
|
char *tempname;
|
|
tree resultdecl = decl;
|
|
|
|
if (DECL_RESULT (decl))
|
|
resultdecl = DECL_RESULT (decl);
|
|
|
|
asprintf (&tempname, "%s.result", name);
|
|
newname = ggc_strdup (tempname);
|
|
free (tempname);
|
|
|
|
resultvi = new_var_info (resultdecl, newname);
|
|
resultvi->offset = fi_result;
|
|
resultvi->size = 1;
|
|
resultvi->fullsize = vi->fullsize;
|
|
resultvi->is_full_var = true;
|
|
if (DECL_RESULT (decl))
|
|
resultvi->may_have_pointers = true;
|
|
gcc_assert (prev_vi->offset < resultvi->offset);
|
|
prev_vi->next = resultvi;
|
|
prev_vi = resultvi;
|
|
if (DECL_RESULT (decl))
|
|
insert_vi_for_tree (DECL_RESULT (decl), resultvi);
|
|
}
|
|
|
|
/* Set up variables for each argument. */
|
|
arg = DECL_ARGUMENTS (decl);
|
|
for (i = 0; i < num_args; i++)
|
|
{
|
|
varinfo_t argvi;
|
|
const char *newname;
|
|
char *tempname;
|
|
tree argdecl = decl;
|
|
|
|
if (arg)
|
|
argdecl = arg;
|
|
|
|
asprintf (&tempname, "%s.arg%d", name, i);
|
|
newname = ggc_strdup (tempname);
|
|
free (tempname);
|
|
|
|
argvi = new_var_info (argdecl, newname);
|
|
argvi->offset = fi_parm_base + i;
|
|
argvi->size = 1;
|
|
argvi->is_full_var = true;
|
|
argvi->fullsize = vi->fullsize;
|
|
if (arg)
|
|
argvi->may_have_pointers = true;
|
|
gcc_assert (prev_vi->offset < argvi->offset);
|
|
prev_vi->next = argvi;
|
|
prev_vi = argvi;
|
|
if (arg)
|
|
{
|
|
insert_vi_for_tree (arg, argvi);
|
|
arg = DECL_CHAIN (arg);
|
|
}
|
|
}
|
|
|
|
/* Add one representative for all further args. */
|
|
if (is_varargs)
|
|
{
|
|
varinfo_t argvi;
|
|
const char *newname;
|
|
char *tempname;
|
|
tree decl;
|
|
|
|
asprintf (&tempname, "%s.varargs", name);
|
|
newname = ggc_strdup (tempname);
|
|
free (tempname);
|
|
|
|
/* We need sth that can be pointed to for va_start. */
|
|
decl = build_fake_var_decl (ptr_type_node);
|
|
|
|
argvi = new_var_info (decl, newname);
|
|
argvi->offset = fi_parm_base + num_args;
|
|
argvi->size = ~0;
|
|
argvi->is_full_var = true;
|
|
argvi->is_heap_var = true;
|
|
argvi->fullsize = vi->fullsize;
|
|
gcc_assert (prev_vi->offset < argvi->offset);
|
|
prev_vi->next = argvi;
|
|
prev_vi = argvi;
|
|
}
|
|
|
|
return vi;
|
|
}
|
|
|
|
|
|
/* Return true if FIELDSTACK contains fields that overlap.
|
|
FIELDSTACK is assumed to be sorted by offset. */
|
|
|
|
static bool
|
|
check_for_overlaps (VEC (fieldoff_s,heap) *fieldstack)
|
|
{
|
|
fieldoff_s *fo = NULL;
|
|
unsigned int i;
|
|
HOST_WIDE_INT lastoffset = -1;
|
|
|
|
FOR_EACH_VEC_ELT (fieldoff_s, fieldstack, i, fo)
|
|
{
|
|
if (fo->offset == lastoffset)
|
|
return true;
|
|
lastoffset = fo->offset;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
|
|
This will also create any varinfo structures necessary for fields
|
|
of DECL. */
|
|
|
|
static varinfo_t
|
|
create_variable_info_for_1 (tree decl, const char *name)
|
|
{
|
|
varinfo_t vi, newvi;
|
|
tree decl_type = TREE_TYPE (decl);
|
|
tree declsize = DECL_P (decl) ? DECL_SIZE (decl) : TYPE_SIZE (decl_type);
|
|
VEC (fieldoff_s,heap) *fieldstack = NULL;
|
|
fieldoff_s *fo;
|
|
unsigned int i;
|
|
|
|
if (!declsize
|
|
|| !host_integerp (declsize, 1))
|
|
{
|
|
vi = new_var_info (decl, name);
|
|
vi->offset = 0;
|
|
vi->size = ~0;
|
|
vi->fullsize = ~0;
|
|
vi->is_unknown_size_var = true;
|
|
vi->is_full_var = true;
|
|
vi->may_have_pointers = true;
|
|
return vi;
|
|
}
|
|
|
|
/* Collect field information. */
|
|
if (use_field_sensitive
|
|
&& var_can_have_subvars (decl)
|
|
/* ??? Force us to not use subfields for global initializers
|
|
in IPA mode. Else we'd have to parse arbitrary initializers. */
|
|
&& !(in_ipa_mode
|
|
&& is_global_var (decl)
|
|
&& DECL_INITIAL (decl)))
|
|
{
|
|
fieldoff_s *fo = NULL;
|
|
bool notokay = false;
|
|
unsigned int i;
|
|
|
|
push_fields_onto_fieldstack (decl_type, &fieldstack, 0);
|
|
|
|
for (i = 0; !notokay && VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
|
|
if (fo->has_unknown_size
|
|
|| fo->offset < 0)
|
|
{
|
|
notokay = true;
|
|
break;
|
|
}
|
|
|
|
/* We can't sort them if we have a field with a variable sized type,
|
|
which will make notokay = true. In that case, we are going to return
|
|
without creating varinfos for the fields anyway, so sorting them is a
|
|
waste to boot. */
|
|
if (!notokay)
|
|
{
|
|
sort_fieldstack (fieldstack);
|
|
/* Due to some C++ FE issues, like PR 22488, we might end up
|
|
what appear to be overlapping fields even though they,
|
|
in reality, do not overlap. Until the C++ FE is fixed,
|
|
we will simply disable field-sensitivity for these cases. */
|
|
notokay = check_for_overlaps (fieldstack);
|
|
}
|
|
|
|
if (notokay)
|
|
VEC_free (fieldoff_s, heap, fieldstack);
|
|
}
|
|
|
|
/* If we didn't end up collecting sub-variables create a full
|
|
variable for the decl. */
|
|
if (VEC_length (fieldoff_s, fieldstack) <= 1
|
|
|| VEC_length (fieldoff_s, fieldstack) > MAX_FIELDS_FOR_FIELD_SENSITIVE)
|
|
{
|
|
vi = new_var_info (decl, name);
|
|
vi->offset = 0;
|
|
vi->may_have_pointers = true;
|
|
vi->fullsize = TREE_INT_CST_LOW (declsize);
|
|
vi->size = vi->fullsize;
|
|
vi->is_full_var = true;
|
|
VEC_free (fieldoff_s, heap, fieldstack);
|
|
return vi;
|
|
}
|
|
|
|
vi = new_var_info (decl, name);
|
|
vi->fullsize = TREE_INT_CST_LOW (declsize);
|
|
for (i = 0, newvi = vi;
|
|
VEC_iterate (fieldoff_s, fieldstack, i, fo);
|
|
++i, newvi = newvi->next)
|
|
{
|
|
const char *newname = "NULL";
|
|
char *tempname;
|
|
|
|
if (dump_file)
|
|
{
|
|
asprintf (&tempname, "%s." HOST_WIDE_INT_PRINT_DEC
|
|
"+" HOST_WIDE_INT_PRINT_DEC, name, fo->offset, fo->size);
|
|
newname = ggc_strdup (tempname);
|
|
free (tempname);
|
|
}
|
|
newvi->name = newname;
|
|
newvi->offset = fo->offset;
|
|
newvi->size = fo->size;
|
|
newvi->fullsize = vi->fullsize;
|
|
newvi->may_have_pointers = fo->may_have_pointers;
|
|
newvi->only_restrict_pointers = fo->only_restrict_pointers;
|
|
if (i + 1 < VEC_length (fieldoff_s, fieldstack))
|
|
newvi->next = new_var_info (decl, name);
|
|
}
|
|
|
|
VEC_free (fieldoff_s, heap, fieldstack);
|
|
|
|
return vi;
|
|
}
|
|
|
|
static unsigned int
|
|
create_variable_info_for (tree decl, const char *name)
|
|
{
|
|
varinfo_t vi = create_variable_info_for_1 (decl, name);
|
|
unsigned int id = vi->id;
|
|
|
|
insert_vi_for_tree (decl, vi);
|
|
|
|
if (TREE_CODE (decl) != VAR_DECL)
|
|
return id;
|
|
|
|
/* Create initial constraints for globals. */
|
|
for (; vi; vi = vi->next)
|
|
{
|
|
if (!vi->may_have_pointers
|
|
|| !vi->is_global_var)
|
|
continue;
|
|
|
|
/* Mark global restrict qualified pointers. */
|
|
if ((POINTER_TYPE_P (TREE_TYPE (decl))
|
|
&& TYPE_RESTRICT (TREE_TYPE (decl)))
|
|
|| vi->only_restrict_pointers)
|
|
{
|
|
make_constraint_from_global_restrict (vi, "GLOBAL_RESTRICT");
|
|
continue;
|
|
}
|
|
|
|
/* In non-IPA mode the initializer from nonlocal is all we need. */
|
|
if (!in_ipa_mode
|
|
|| DECL_HARD_REGISTER (decl))
|
|
make_copy_constraint (vi, nonlocal_id);
|
|
|
|
/* In IPA mode parse the initializer and generate proper constraints
|
|
for it. */
|
|
else
|
|
{
|
|
struct varpool_node *vnode = varpool_get_node (decl);
|
|
|
|
/* For escaped variables initialize them from nonlocal. */
|
|
if (!varpool_all_refs_explicit_p (vnode))
|
|
make_copy_constraint (vi, nonlocal_id);
|
|
|
|
/* If this is a global variable with an initializer and we are in
|
|
IPA mode generate constraints for it. */
|
|
if (DECL_INITIAL (decl))
|
|
{
|
|
VEC (ce_s, heap) *rhsc = NULL;
|
|
struct constraint_expr lhs, *rhsp;
|
|
unsigned i;
|
|
get_constraint_for_rhs (DECL_INITIAL (decl), &rhsc);
|
|
lhs.var = vi->id;
|
|
lhs.offset = 0;
|
|
lhs.type = SCALAR;
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
/* If this is a variable that escapes from the unit
|
|
the initializer escapes as well. */
|
|
if (!varpool_all_refs_explicit_p (vnode))
|
|
{
|
|
lhs.var = escaped_id;
|
|
lhs.offset = 0;
|
|
lhs.type = SCALAR;
|
|
FOR_EACH_VEC_ELT (ce_s, rhsc, i, rhsp)
|
|
process_constraint (new_constraint (lhs, *rhsp));
|
|
}
|
|
VEC_free (ce_s, heap, rhsc);
|
|
}
|
|
}
|
|
}
|
|
|
|
return id;
|
|
}
|
|
|
|
/* Print out the points-to solution for VAR to FILE. */
|
|
|
|
static void
|
|
dump_solution_for_var (FILE *file, unsigned int var)
|
|
{
|
|
varinfo_t vi = get_varinfo (var);
|
|
unsigned int i;
|
|
bitmap_iterator bi;
|
|
|
|
/* Dump the solution for unified vars anyway, this avoids difficulties
|
|
in scanning dumps in the testsuite. */
|
|
fprintf (file, "%s = { ", vi->name);
|
|
vi = get_varinfo (find (var));
|
|
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
|
|
fprintf (file, "%s ", get_varinfo (i)->name);
|
|
fprintf (file, "}");
|
|
|
|
/* But note when the variable was unified. */
|
|
if (vi->id != var)
|
|
fprintf (file, " same as %s", vi->name);
|
|
|
|
fprintf (file, "\n");
|
|
}
|
|
|
|
/* Print the points-to solution for VAR to stdout. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_solution_for_var (unsigned int var)
|
|
{
|
|
dump_solution_for_var (stdout, var);
|
|
}
|
|
|
|
/* Create varinfo structures for all of the variables in the
|
|
function for intraprocedural mode. */
|
|
|
|
static void
|
|
intra_create_variable_infos (void)
|
|
{
|
|
tree t;
|
|
|
|
/* For each incoming pointer argument arg, create the constraint ARG
|
|
= NONLOCAL or a dummy variable if it is a restrict qualified
|
|
passed-by-reference argument. */
|
|
for (t = DECL_ARGUMENTS (current_function_decl); t; t = DECL_CHAIN (t))
|
|
{
|
|
varinfo_t p = get_vi_for_tree (t);
|
|
|
|
/* For restrict qualified pointers to objects passed by
|
|
reference build a real representative for the pointed-to object.
|
|
Treat restrict qualified references the same. */
|
|
if (TYPE_RESTRICT (TREE_TYPE (t))
|
|
&& ((DECL_BY_REFERENCE (t) && POINTER_TYPE_P (TREE_TYPE (t)))
|
|
|| TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE))
|
|
{
|
|
struct constraint_expr lhsc, rhsc;
|
|
varinfo_t vi;
|
|
tree heapvar = build_fake_var_decl (TREE_TYPE (TREE_TYPE (t)));
|
|
DECL_EXTERNAL (heapvar) = 1;
|
|
vi = create_variable_info_for_1 (heapvar, "PARM_NOALIAS");
|
|
insert_vi_for_tree (heapvar, vi);
|
|
lhsc.var = p->id;
|
|
lhsc.type = SCALAR;
|
|
lhsc.offset = 0;
|
|
rhsc.var = vi->id;
|
|
rhsc.type = ADDRESSOF;
|
|
rhsc.offset = 0;
|
|
process_constraint (new_constraint (lhsc, rhsc));
|
|
for (; vi; vi = vi->next)
|
|
if (vi->may_have_pointers)
|
|
{
|
|
if (vi->only_restrict_pointers)
|
|
make_constraint_from_global_restrict (vi, "GLOBAL_RESTRICT");
|
|
else
|
|
make_copy_constraint (vi, nonlocal_id);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
if (POINTER_TYPE_P (TREE_TYPE (t))
|
|
&& TYPE_RESTRICT (TREE_TYPE (t)))
|
|
make_constraint_from_global_restrict (p, "PARM_RESTRICT");
|
|
else
|
|
{
|
|
for (; p; p = p->next)
|
|
{
|
|
if (p->only_restrict_pointers)
|
|
make_constraint_from_global_restrict (p, "PARM_RESTRICT");
|
|
else if (p->may_have_pointers)
|
|
make_constraint_from (p, nonlocal_id);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Add a constraint for a result decl that is passed by reference. */
|
|
if (DECL_RESULT (cfun->decl)
|
|
&& DECL_BY_REFERENCE (DECL_RESULT (cfun->decl)))
|
|
{
|
|
varinfo_t p, result_vi = get_vi_for_tree (DECL_RESULT (cfun->decl));
|
|
|
|
for (p = result_vi; p; p = p->next)
|
|
make_constraint_from (p, nonlocal_id);
|
|
}
|
|
|
|
/* Add a constraint for the incoming static chain parameter. */
|
|
if (cfun->static_chain_decl != NULL_TREE)
|
|
{
|
|
varinfo_t p, chain_vi = get_vi_for_tree (cfun->static_chain_decl);
|
|
|
|
for (p = chain_vi; p; p = p->next)
|
|
make_constraint_from (p, nonlocal_id);
|
|
}
|
|
}
|
|
|
|
/* Structure used to put solution bitmaps in a hashtable so they can
|
|
be shared among variables with the same points-to set. */
|
|
|
|
typedef struct shared_bitmap_info
|
|
{
|
|
bitmap pt_vars;
|
|
hashval_t hashcode;
|
|
} *shared_bitmap_info_t;
|
|
typedef const struct shared_bitmap_info *const_shared_bitmap_info_t;
|
|
|
|
static htab_t shared_bitmap_table;
|
|
|
|
/* Hash function for a shared_bitmap_info_t */
|
|
|
|
static hashval_t
|
|
shared_bitmap_hash (const void *p)
|
|
{
|
|
const_shared_bitmap_info_t const bi = (const_shared_bitmap_info_t) p;
|
|
return bi->hashcode;
|
|
}
|
|
|
|
/* Equality function for two shared_bitmap_info_t's. */
|
|
|
|
static int
|
|
shared_bitmap_eq (const void *p1, const void *p2)
|
|
{
|
|
const_shared_bitmap_info_t const sbi1 = (const_shared_bitmap_info_t) p1;
|
|
const_shared_bitmap_info_t const sbi2 = (const_shared_bitmap_info_t) p2;
|
|
return bitmap_equal_p (sbi1->pt_vars, sbi2->pt_vars);
|
|
}
|
|
|
|
/* Lookup a bitmap in the shared bitmap hashtable, and return an already
|
|
existing instance if there is one, NULL otherwise. */
|
|
|
|
static bitmap
|
|
shared_bitmap_lookup (bitmap pt_vars)
|
|
{
|
|
void **slot;
|
|
struct shared_bitmap_info sbi;
|
|
|
|
sbi.pt_vars = pt_vars;
|
|
sbi.hashcode = bitmap_hash (pt_vars);
|
|
|
|
slot = htab_find_slot_with_hash (shared_bitmap_table, &sbi,
|
|
sbi.hashcode, NO_INSERT);
|
|
if (!slot)
|
|
return NULL;
|
|
else
|
|
return ((shared_bitmap_info_t) *slot)->pt_vars;
|
|
}
|
|
|
|
|
|
/* Add a bitmap to the shared bitmap hashtable. */
|
|
|
|
static void
|
|
shared_bitmap_add (bitmap pt_vars)
|
|
{
|
|
void **slot;
|
|
shared_bitmap_info_t sbi = XNEW (struct shared_bitmap_info);
|
|
|
|
sbi->pt_vars = pt_vars;
|
|
sbi->hashcode = bitmap_hash (pt_vars);
|
|
|
|
slot = htab_find_slot_with_hash (shared_bitmap_table, sbi,
|
|
sbi->hashcode, INSERT);
|
|
gcc_assert (!*slot);
|
|
*slot = (void *) sbi;
|
|
}
|
|
|
|
|
|
/* Set bits in INTO corresponding to the variable uids in solution set FROM. */
|
|
|
|
static void
|
|
set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt)
|
|
{
|
|
unsigned int i;
|
|
bitmap_iterator bi;
|
|
|
|
EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
|
|
{
|
|
varinfo_t vi = get_varinfo (i);
|
|
|
|
/* The only artificial variables that are allowed in a may-alias
|
|
set are heap variables. */
|
|
if (vi->is_artificial_var && !vi->is_heap_var)
|
|
continue;
|
|
|
|
if (TREE_CODE (vi->decl) == VAR_DECL
|
|
|| TREE_CODE (vi->decl) == PARM_DECL
|
|
|| TREE_CODE (vi->decl) == RESULT_DECL)
|
|
{
|
|
/* If we are in IPA mode we will not recompute points-to
|
|
sets after inlining so make sure they stay valid. */
|
|
if (in_ipa_mode
|
|
&& !DECL_PT_UID_SET_P (vi->decl))
|
|
SET_DECL_PT_UID (vi->decl, DECL_UID (vi->decl));
|
|
|
|
/* Add the decl to the points-to set. Note that the points-to
|
|
set contains global variables. */
|
|
bitmap_set_bit (into, DECL_PT_UID (vi->decl));
|
|
if (vi->is_global_var)
|
|
pt->vars_contains_global = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/* Compute the points-to solution *PT for the variable VI. */
|
|
|
|
static void
|
|
find_what_var_points_to (varinfo_t orig_vi, struct pt_solution *pt)
|
|
{
|
|
unsigned int i;
|
|
bitmap_iterator bi;
|
|
bitmap finished_solution;
|
|
bitmap result;
|
|
varinfo_t vi;
|
|
|
|
memset (pt, 0, sizeof (struct pt_solution));
|
|
|
|
/* This variable may have been collapsed, let's get the real
|
|
variable. */
|
|
vi = get_varinfo (find (orig_vi->id));
|
|
|
|
/* Translate artificial variables into SSA_NAME_PTR_INFO
|
|
attributes. */
|
|
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
|
|
{
|
|
varinfo_t vi = get_varinfo (i);
|
|
|
|
if (vi->is_artificial_var)
|
|
{
|
|
if (vi->id == nothing_id)
|
|
pt->null = 1;
|
|
else if (vi->id == escaped_id)
|
|
{
|
|
if (in_ipa_mode)
|
|
pt->ipa_escaped = 1;
|
|
else
|
|
pt->escaped = 1;
|
|
}
|
|
else if (vi->id == nonlocal_id)
|
|
pt->nonlocal = 1;
|
|
else if (vi->is_heap_var)
|
|
/* We represent heapvars in the points-to set properly. */
|
|
;
|
|
else if (vi->id == readonly_id)
|
|
/* Nobody cares. */
|
|
;
|
|
else if (vi->id == anything_id
|
|
|| vi->id == integer_id)
|
|
pt->anything = 1;
|
|
}
|
|
}
|
|
|
|
/* Instead of doing extra work, simply do not create
|
|
elaborate points-to information for pt_anything pointers. */
|
|
if (pt->anything)
|
|
return;
|
|
|
|
/* Share the final set of variables when possible. */
|
|
finished_solution = BITMAP_GGC_ALLOC ();
|
|
stats.points_to_sets_created++;
|
|
|
|
set_uids_in_ptset (finished_solution, vi->solution, pt);
|
|
result = shared_bitmap_lookup (finished_solution);
|
|
if (!result)
|
|
{
|
|
shared_bitmap_add (finished_solution);
|
|
pt->vars = finished_solution;
|
|
}
|
|
else
|
|
{
|
|
pt->vars = result;
|
|
bitmap_clear (finished_solution);
|
|
}
|
|
}
|
|
|
|
/* Given a pointer variable P, fill in its points-to set. */
|
|
|
|
static void
|
|
find_what_p_points_to (tree p)
|
|
{
|
|
struct ptr_info_def *pi;
|
|
tree lookup_p = p;
|
|
varinfo_t vi;
|
|
|
|
/* For parameters, get at the points-to set for the actual parm
|
|
decl. */
|
|
if (TREE_CODE (p) == SSA_NAME
|
|
&& (TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL
|
|
|| TREE_CODE (SSA_NAME_VAR (p)) == RESULT_DECL)
|
|
&& SSA_NAME_IS_DEFAULT_DEF (p))
|
|
lookup_p = SSA_NAME_VAR (p);
|
|
|
|
vi = lookup_vi_for_tree (lookup_p);
|
|
if (!vi)
|
|
return;
|
|
|
|
pi = get_ptr_info (p);
|
|
find_what_var_points_to (vi, &pi->pt);
|
|
}
|
|
|
|
|
|
/* Query statistics for points-to solutions. */
|
|
|
|
static struct {
|
|
unsigned HOST_WIDE_INT pt_solution_includes_may_alias;
|
|
unsigned HOST_WIDE_INT pt_solution_includes_no_alias;
|
|
unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias;
|
|
unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias;
|
|
} pta_stats;
|
|
|
|
void
|
|
dump_pta_stats (FILE *s)
|
|
{
|
|
fprintf (s, "\nPTA query stats:\n");
|
|
fprintf (s, " pt_solution_includes: "
|
|
HOST_WIDE_INT_PRINT_DEC" disambiguations, "
|
|
HOST_WIDE_INT_PRINT_DEC" queries\n",
|
|
pta_stats.pt_solution_includes_no_alias,
|
|
pta_stats.pt_solution_includes_no_alias
|
|
+ pta_stats.pt_solution_includes_may_alias);
|
|
fprintf (s, " pt_solutions_intersect: "
|
|
HOST_WIDE_INT_PRINT_DEC" disambiguations, "
|
|
HOST_WIDE_INT_PRINT_DEC" queries\n",
|
|
pta_stats.pt_solutions_intersect_no_alias,
|
|
pta_stats.pt_solutions_intersect_no_alias
|
|
+ pta_stats.pt_solutions_intersect_may_alias);
|
|
}
|
|
|
|
|
|
/* Reset the points-to solution *PT to a conservative default
|
|
(point to anything). */
|
|
|
|
void
|
|
pt_solution_reset (struct pt_solution *pt)
|
|
{
|
|
memset (pt, 0, sizeof (struct pt_solution));
|
|
pt->anything = true;
|
|
}
|
|
|
|
/* Set the points-to solution *PT to point only to the variables
|
|
in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
|
|
global variables and VARS_CONTAINS_RESTRICT specifies whether
|
|
it contains restrict tag variables. */
|
|
|
|
void
|
|
pt_solution_set (struct pt_solution *pt, bitmap vars, bool vars_contains_global)
|
|
{
|
|
memset (pt, 0, sizeof (struct pt_solution));
|
|
pt->vars = vars;
|
|
pt->vars_contains_global = vars_contains_global;
|
|
}
|
|
|
|
/* Set the points-to solution *PT to point only to the variable VAR. */
|
|
|
|
void
|
|
pt_solution_set_var (struct pt_solution *pt, tree var)
|
|
{
|
|
memset (pt, 0, sizeof (struct pt_solution));
|
|
pt->vars = BITMAP_GGC_ALLOC ();
|
|
bitmap_set_bit (pt->vars, DECL_PT_UID (var));
|
|
pt->vars_contains_global = is_global_var (var);
|
|
}
|
|
|
|
/* Computes the union of the points-to solutions *DEST and *SRC and
|
|
stores the result in *DEST. This changes the points-to bitmap
|
|
of *DEST and thus may not be used if that might be shared.
|
|
The points-to bitmap of *SRC and *DEST will not be shared after
|
|
this function if they were not before. */
|
|
|
|
static void
|
|
pt_solution_ior_into (struct pt_solution *dest, struct pt_solution *src)
|
|
{
|
|
dest->anything |= src->anything;
|
|
if (dest->anything)
|
|
{
|
|
pt_solution_reset (dest);
|
|
return;
|
|
}
|
|
|
|
dest->nonlocal |= src->nonlocal;
|
|
dest->escaped |= src->escaped;
|
|
dest->ipa_escaped |= src->ipa_escaped;
|
|
dest->null |= src->null;
|
|
dest->vars_contains_global |= src->vars_contains_global;
|
|
if (!src->vars)
|
|
return;
|
|
|
|
if (!dest->vars)
|
|
dest->vars = BITMAP_GGC_ALLOC ();
|
|
bitmap_ior_into (dest->vars, src->vars);
|
|
}
|
|
|
|
/* Return true if the points-to solution *PT is empty. */
|
|
|
|
bool
|
|
pt_solution_empty_p (struct pt_solution *pt)
|
|
{
|
|
if (pt->anything
|
|
|| pt->nonlocal)
|
|
return false;
|
|
|
|
if (pt->vars
|
|
&& !bitmap_empty_p (pt->vars))
|
|
return false;
|
|
|
|
/* If the solution includes ESCAPED, check if that is empty. */
|
|
if (pt->escaped
|
|
&& !pt_solution_empty_p (&cfun->gimple_df->escaped))
|
|
return false;
|
|
|
|
/* If the solution includes ESCAPED, check if that is empty. */
|
|
if (pt->ipa_escaped
|
|
&& !pt_solution_empty_p (&ipa_escaped_pt))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Return true if the points-to solution *PT only point to a single var, and
|
|
return the var uid in *UID. */
|
|
|
|
bool
|
|
pt_solution_singleton_p (struct pt_solution *pt, unsigned *uid)
|
|
{
|
|
if (pt->anything || pt->nonlocal || pt->escaped || pt->ipa_escaped
|
|
|| pt->null || pt->vars == NULL
|
|
|| !bitmap_single_bit_set_p (pt->vars))
|
|
return false;
|
|
|
|
*uid = bitmap_first_set_bit (pt->vars);
|
|
return true;
|
|
}
|
|
|
|
/* Return true if the points-to solution *PT includes global memory. */
|
|
|
|
bool
|
|
pt_solution_includes_global (struct pt_solution *pt)
|
|
{
|
|
if (pt->anything
|
|
|| pt->nonlocal
|
|
|| pt->vars_contains_global)
|
|
return true;
|
|
|
|
if (pt->escaped)
|
|
return pt_solution_includes_global (&cfun->gimple_df->escaped);
|
|
|
|
if (pt->ipa_escaped)
|
|
return pt_solution_includes_global (&ipa_escaped_pt);
|
|
|
|
/* ??? This predicate is not correct for the IPA-PTA solution
|
|
as we do not properly distinguish between unit escape points
|
|
and global variables. */
|
|
if (cfun->gimple_df->ipa_pta)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Return true if the points-to solution *PT includes the variable
|
|
declaration DECL. */
|
|
|
|
static bool
|
|
pt_solution_includes_1 (struct pt_solution *pt, const_tree decl)
|
|
{
|
|
if (pt->anything)
|
|
return true;
|
|
|
|
if (pt->nonlocal
|
|
&& is_global_var (decl))
|
|
return true;
|
|
|
|
if (pt->vars
|
|
&& bitmap_bit_p (pt->vars, DECL_PT_UID (decl)))
|
|
return true;
|
|
|
|
/* If the solution includes ESCAPED, check it. */
|
|
if (pt->escaped
|
|
&& pt_solution_includes_1 (&cfun->gimple_df->escaped, decl))
|
|
return true;
|
|
|
|
/* If the solution includes ESCAPED, check it. */
|
|
if (pt->ipa_escaped
|
|
&& pt_solution_includes_1 (&ipa_escaped_pt, decl))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
bool
|
|
pt_solution_includes (struct pt_solution *pt, const_tree decl)
|
|
{
|
|
bool res = pt_solution_includes_1 (pt, decl);
|
|
if (res)
|
|
++pta_stats.pt_solution_includes_may_alias;
|
|
else
|
|
++pta_stats.pt_solution_includes_no_alias;
|
|
return res;
|
|
}
|
|
|
|
/* Return true if both points-to solutions PT1 and PT2 have a non-empty
|
|
intersection. */
|
|
|
|
static bool
|
|
pt_solutions_intersect_1 (struct pt_solution *pt1, struct pt_solution *pt2)
|
|
{
|
|
if (pt1->anything || pt2->anything)
|
|
return true;
|
|
|
|
/* If either points to unknown global memory and the other points to
|
|
any global memory they alias. */
|
|
if ((pt1->nonlocal
|
|
&& (pt2->nonlocal
|
|
|| pt2->vars_contains_global))
|
|
|| (pt2->nonlocal
|
|
&& pt1->vars_contains_global))
|
|
return true;
|
|
|
|
/* Check the escaped solution if required. */
|
|
if ((pt1->escaped || pt2->escaped)
|
|
&& !pt_solution_empty_p (&cfun->gimple_df->escaped))
|
|
{
|
|
/* If both point to escaped memory and that solution
|
|
is not empty they alias. */
|
|
if (pt1->escaped && pt2->escaped)
|
|
return true;
|
|
|
|
/* If either points to escaped memory see if the escaped solution
|
|
intersects with the other. */
|
|
if ((pt1->escaped
|
|
&& pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt2))
|
|
|| (pt2->escaped
|
|
&& pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt1)))
|
|
return true;
|
|
}
|
|
|
|
/* Check the escaped solution if required.
|
|
??? Do we need to check the local against the IPA escaped sets? */
|
|
if ((pt1->ipa_escaped || pt2->ipa_escaped)
|
|
&& !pt_solution_empty_p (&ipa_escaped_pt))
|
|
{
|
|
/* If both point to escaped memory and that solution
|
|
is not empty they alias. */
|
|
if (pt1->ipa_escaped && pt2->ipa_escaped)
|
|
return true;
|
|
|
|
/* If either points to escaped memory see if the escaped solution
|
|
intersects with the other. */
|
|
if ((pt1->ipa_escaped
|
|
&& pt_solutions_intersect_1 (&ipa_escaped_pt, pt2))
|
|
|| (pt2->ipa_escaped
|
|
&& pt_solutions_intersect_1 (&ipa_escaped_pt, pt1)))
|
|
return true;
|
|
}
|
|
|
|
/* Now both pointers alias if their points-to solution intersects. */
|
|
return (pt1->vars
|
|
&& pt2->vars
|
|
&& bitmap_intersect_p (pt1->vars, pt2->vars));
|
|
}
|
|
|
|
bool
|
|
pt_solutions_intersect (struct pt_solution *pt1, struct pt_solution *pt2)
|
|
{
|
|
bool res = pt_solutions_intersect_1 (pt1, pt2);
|
|
if (res)
|
|
++pta_stats.pt_solutions_intersect_may_alias;
|
|
else
|
|
++pta_stats.pt_solutions_intersect_no_alias;
|
|
return res;
|
|
}
|
|
|
|
|
|
/* Dump points-to information to OUTFILE. */
|
|
|
|
static void
|
|
dump_sa_points_to_info (FILE *outfile)
|
|
{
|
|
unsigned int i;
|
|
|
|
fprintf (outfile, "\nPoints-to sets\n\n");
|
|
|
|
if (dump_flags & TDF_STATS)
|
|
{
|
|
fprintf (outfile, "Stats:\n");
|
|
fprintf (outfile, "Total vars: %d\n", stats.total_vars);
|
|
fprintf (outfile, "Non-pointer vars: %d\n",
|
|
stats.nonpointer_vars);
|
|
fprintf (outfile, "Statically unified vars: %d\n",
|
|
stats.unified_vars_static);
|
|
fprintf (outfile, "Dynamically unified vars: %d\n",
|
|
stats.unified_vars_dynamic);
|
|
fprintf (outfile, "Iterations: %d\n", stats.iterations);
|
|
fprintf (outfile, "Number of edges: %d\n", stats.num_edges);
|
|
fprintf (outfile, "Number of implicit edges: %d\n",
|
|
stats.num_implicit_edges);
|
|
}
|
|
|
|
for (i = 0; i < VEC_length (varinfo_t, varmap); i++)
|
|
{
|
|
varinfo_t vi = get_varinfo (i);
|
|
if (!vi->may_have_pointers)
|
|
continue;
|
|
dump_solution_for_var (outfile, i);
|
|
}
|
|
}
|
|
|
|
|
|
/* Debug points-to information to stderr. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_sa_points_to_info (void)
|
|
{
|
|
dump_sa_points_to_info (stderr);
|
|
}
|
|
|
|
|
|
/* Initialize the always-existing constraint variables for NULL
|
|
ANYTHING, READONLY, and INTEGER */
|
|
|
|
static void
|
|
init_base_vars (void)
|
|
{
|
|
struct constraint_expr lhs, rhs;
|
|
varinfo_t var_anything;
|
|
varinfo_t var_nothing;
|
|
varinfo_t var_readonly;
|
|
varinfo_t var_escaped;
|
|
varinfo_t var_nonlocal;
|
|
varinfo_t var_storedanything;
|
|
varinfo_t var_integer;
|
|
|
|
/* Create the NULL variable, used to represent that a variable points
|
|
to NULL. */
|
|
var_nothing = new_var_info (NULL_TREE, "NULL");
|
|
gcc_assert (var_nothing->id == nothing_id);
|
|
var_nothing->is_artificial_var = 1;
|
|
var_nothing->offset = 0;
|
|
var_nothing->size = ~0;
|
|
var_nothing->fullsize = ~0;
|
|
var_nothing->is_special_var = 1;
|
|
var_nothing->may_have_pointers = 0;
|
|
var_nothing->is_global_var = 0;
|
|
|
|
/* Create the ANYTHING variable, used to represent that a variable
|
|
points to some unknown piece of memory. */
|
|
var_anything = new_var_info (NULL_TREE, "ANYTHING");
|
|
gcc_assert (var_anything->id == anything_id);
|
|
var_anything->is_artificial_var = 1;
|
|
var_anything->size = ~0;
|
|
var_anything->offset = 0;
|
|
var_anything->next = NULL;
|
|
var_anything->fullsize = ~0;
|
|
var_anything->is_special_var = 1;
|
|
|
|
/* Anything points to anything. This makes deref constraints just
|
|
work in the presence of linked list and other p = *p type loops,
|
|
by saying that *ANYTHING = ANYTHING. */
|
|
lhs.type = SCALAR;
|
|
lhs.var = anything_id;
|
|
lhs.offset = 0;
|
|
rhs.type = ADDRESSOF;
|
|
rhs.var = anything_id;
|
|
rhs.offset = 0;
|
|
|
|
/* This specifically does not use process_constraint because
|
|
process_constraint ignores all anything = anything constraints, since all
|
|
but this one are redundant. */
|
|
VEC_safe_push (constraint_t, heap, constraints, new_constraint (lhs, rhs));
|
|
|
|
/* Create the READONLY variable, used to represent that a variable
|
|
points to readonly memory. */
|
|
var_readonly = new_var_info (NULL_TREE, "READONLY");
|
|
gcc_assert (var_readonly->id == readonly_id);
|
|
var_readonly->is_artificial_var = 1;
|
|
var_readonly->offset = 0;
|
|
var_readonly->size = ~0;
|
|
var_readonly->fullsize = ~0;
|
|
var_readonly->next = NULL;
|
|
var_readonly->is_special_var = 1;
|
|
|
|
/* readonly memory points to anything, in order to make deref
|
|
easier. In reality, it points to anything the particular
|
|
readonly variable can point to, but we don't track this
|
|
separately. */
|
|
lhs.type = SCALAR;
|
|
lhs.var = readonly_id;
|
|
lhs.offset = 0;
|
|
rhs.type = ADDRESSOF;
|
|
rhs.var = readonly_id; /* FIXME */
|
|
rhs.offset = 0;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
|
|
/* Create the ESCAPED variable, used to represent the set of escaped
|
|
memory. */
|
|
var_escaped = new_var_info (NULL_TREE, "ESCAPED");
|
|
gcc_assert (var_escaped->id == escaped_id);
|
|
var_escaped->is_artificial_var = 1;
|
|
var_escaped->offset = 0;
|
|
var_escaped->size = ~0;
|
|
var_escaped->fullsize = ~0;
|
|
var_escaped->is_special_var = 0;
|
|
|
|
/* Create the NONLOCAL variable, used to represent the set of nonlocal
|
|
memory. */
|
|
var_nonlocal = new_var_info (NULL_TREE, "NONLOCAL");
|
|
gcc_assert (var_nonlocal->id == nonlocal_id);
|
|
var_nonlocal->is_artificial_var = 1;
|
|
var_nonlocal->offset = 0;
|
|
var_nonlocal->size = ~0;
|
|
var_nonlocal->fullsize = ~0;
|
|
var_nonlocal->is_special_var = 1;
|
|
|
|
/* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
|
|
lhs.type = SCALAR;
|
|
lhs.var = escaped_id;
|
|
lhs.offset = 0;
|
|
rhs.type = DEREF;
|
|
rhs.var = escaped_id;
|
|
rhs.offset = 0;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
|
|
/* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
|
|
whole variable escapes. */
|
|
lhs.type = SCALAR;
|
|
lhs.var = escaped_id;
|
|
lhs.offset = 0;
|
|
rhs.type = SCALAR;
|
|
rhs.var = escaped_id;
|
|
rhs.offset = UNKNOWN_OFFSET;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
|
|
/* *ESCAPED = NONLOCAL. This is true because we have to assume
|
|
everything pointed to by escaped points to what global memory can
|
|
point to. */
|
|
lhs.type = DEREF;
|
|
lhs.var = escaped_id;
|
|
lhs.offset = 0;
|
|
rhs.type = SCALAR;
|
|
rhs.var = nonlocal_id;
|
|
rhs.offset = 0;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
|
|
/* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
|
|
global memory may point to global memory and escaped memory. */
|
|
lhs.type = SCALAR;
|
|
lhs.var = nonlocal_id;
|
|
lhs.offset = 0;
|
|
rhs.type = ADDRESSOF;
|
|
rhs.var = nonlocal_id;
|
|
rhs.offset = 0;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
rhs.type = ADDRESSOF;
|
|
rhs.var = escaped_id;
|
|
rhs.offset = 0;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
|
|
/* Create the STOREDANYTHING variable, used to represent the set of
|
|
variables stored to *ANYTHING. */
|
|
var_storedanything = new_var_info (NULL_TREE, "STOREDANYTHING");
|
|
gcc_assert (var_storedanything->id == storedanything_id);
|
|
var_storedanything->is_artificial_var = 1;
|
|
var_storedanything->offset = 0;
|
|
var_storedanything->size = ~0;
|
|
var_storedanything->fullsize = ~0;
|
|
var_storedanything->is_special_var = 0;
|
|
|
|
/* Create the INTEGER variable, used to represent that a variable points
|
|
to what an INTEGER "points to". */
|
|
var_integer = new_var_info (NULL_TREE, "INTEGER");
|
|
gcc_assert (var_integer->id == integer_id);
|
|
var_integer->is_artificial_var = 1;
|
|
var_integer->size = ~0;
|
|
var_integer->fullsize = ~0;
|
|
var_integer->offset = 0;
|
|
var_integer->next = NULL;
|
|
var_integer->is_special_var = 1;
|
|
|
|
/* INTEGER = ANYTHING, because we don't know where a dereference of
|
|
a random integer will point to. */
|
|
lhs.type = SCALAR;
|
|
lhs.var = integer_id;
|
|
lhs.offset = 0;
|
|
rhs.type = ADDRESSOF;
|
|
rhs.var = anything_id;
|
|
rhs.offset = 0;
|
|
process_constraint (new_constraint (lhs, rhs));
|
|
}
|
|
|
|
/* Initialize things necessary to perform PTA */
|
|
|
|
static void
|
|
init_alias_vars (void)
|
|
{
|
|
use_field_sensitive = (MAX_FIELDS_FOR_FIELD_SENSITIVE > 1);
|
|
|
|
bitmap_obstack_initialize (&pta_obstack);
|
|
bitmap_obstack_initialize (&oldpta_obstack);
|
|
bitmap_obstack_initialize (&predbitmap_obstack);
|
|
|
|
constraint_pool = create_alloc_pool ("Constraint pool",
|
|
sizeof (struct constraint), 30);
|
|
variable_info_pool = create_alloc_pool ("Variable info pool",
|
|
sizeof (struct variable_info), 30);
|
|
constraints = VEC_alloc (constraint_t, heap, 8);
|
|
varmap = VEC_alloc (varinfo_t, heap, 8);
|
|
vi_for_tree = pointer_map_create ();
|
|
call_stmt_vars = pointer_map_create ();
|
|
|
|
memset (&stats, 0, sizeof (stats));
|
|
shared_bitmap_table = htab_create (511, shared_bitmap_hash,
|
|
shared_bitmap_eq, free);
|
|
init_base_vars ();
|
|
|
|
gcc_obstack_init (&fake_var_decl_obstack);
|
|
}
|
|
|
|
/* Remove the REF and ADDRESS edges from GRAPH, as well as all the
|
|
predecessor edges. */
|
|
|
|
static void
|
|
remove_preds_and_fake_succs (constraint_graph_t graph)
|
|
{
|
|
unsigned int i;
|
|
|
|
/* Clear the implicit ref and address nodes from the successor
|
|
lists. */
|
|
for (i = 0; i < FIRST_REF_NODE; i++)
|
|
{
|
|
if (graph->succs[i])
|
|
bitmap_clear_range (graph->succs[i], FIRST_REF_NODE,
|
|
FIRST_REF_NODE * 2);
|
|
}
|
|
|
|
/* Free the successor list for the non-ref nodes. */
|
|
for (i = FIRST_REF_NODE; i < graph->size; i++)
|
|
{
|
|
if (graph->succs[i])
|
|
BITMAP_FREE (graph->succs[i]);
|
|
}
|
|
|
|
/* Now reallocate the size of the successor list as, and blow away
|
|
the predecessor bitmaps. */
|
|
graph->size = VEC_length (varinfo_t, varmap);
|
|
graph->succs = XRESIZEVEC (bitmap, graph->succs, graph->size);
|
|
|
|
free (graph->implicit_preds);
|
|
graph->implicit_preds = NULL;
|
|
free (graph->preds);
|
|
graph->preds = NULL;
|
|
bitmap_obstack_release (&predbitmap_obstack);
|
|
}
|
|
|
|
/* Solve the constraint set. */
|
|
|
|
static void
|
|
solve_constraints (void)
|
|
{
|
|
struct scc_info *si;
|
|
|
|
if (dump_file)
|
|
fprintf (dump_file,
|
|
"\nCollapsing static cycles and doing variable "
|
|
"substitution\n");
|
|
|
|
init_graph (VEC_length (varinfo_t, varmap) * 2);
|
|
|
|
if (dump_file)
|
|
fprintf (dump_file, "Building predecessor graph\n");
|
|
build_pred_graph ();
|
|
|
|
if (dump_file)
|
|
fprintf (dump_file, "Detecting pointer and location "
|
|
"equivalences\n");
|
|
si = perform_var_substitution (graph);
|
|
|
|
if (dump_file)
|
|
fprintf (dump_file, "Rewriting constraints and unifying "
|
|
"variables\n");
|
|
rewrite_constraints (graph, si);
|
|
|
|
build_succ_graph ();
|
|
|
|
free_var_substitution_info (si);
|
|
|
|
/* Attach complex constraints to graph nodes. */
|
|
move_complex_constraints (graph);
|
|
|
|
if (dump_file)
|
|
fprintf (dump_file, "Uniting pointer but not location equivalent "
|
|
"variables\n");
|
|
unite_pointer_equivalences (graph);
|
|
|
|
if (dump_file)
|
|
fprintf (dump_file, "Finding indirect cycles\n");
|
|
find_indirect_cycles (graph);
|
|
|
|
/* Implicit nodes and predecessors are no longer necessary at this
|
|
point. */
|
|
remove_preds_and_fake_succs (graph);
|
|
|
|
if (dump_file && (dump_flags & TDF_GRAPH))
|
|
{
|
|
fprintf (dump_file, "\n\n// The constraint graph before solve-graph "
|
|
"in dot format:\n");
|
|
dump_constraint_graph (dump_file);
|
|
fprintf (dump_file, "\n\n");
|
|
}
|
|
|
|
if (dump_file)
|
|
fprintf (dump_file, "Solving graph\n");
|
|
|
|
solve_graph (graph);
|
|
|
|
if (dump_file && (dump_flags & TDF_GRAPH))
|
|
{
|
|
fprintf (dump_file, "\n\n// The constraint graph after solve-graph "
|
|
"in dot format:\n");
|
|
dump_constraint_graph (dump_file);
|
|
fprintf (dump_file, "\n\n");
|
|
}
|
|
|
|
if (dump_file)
|
|
dump_sa_points_to_info (dump_file);
|
|
}
|
|
|
|
/* Create points-to sets for the current function. See the comments
|
|
at the start of the file for an algorithmic overview. */
|
|
|
|
static void
|
|
compute_points_to_sets (void)
|
|
{
|
|
basic_block bb;
|
|
unsigned i;
|
|
varinfo_t vi;
|
|
|
|
timevar_push (TV_TREE_PTA);
|
|
|
|
init_alias_vars ();
|
|
|
|
intra_create_variable_infos ();
|
|
|
|
/* Now walk all statements and build the constraint set. */
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
gimple_stmt_iterator gsi;
|
|
|
|
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
|
{
|
|
gimple phi = gsi_stmt (gsi);
|
|
|
|
if (is_gimple_reg (gimple_phi_result (phi)))
|
|
find_func_aliases (phi);
|
|
}
|
|
|
|
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
|
{
|
|
gimple stmt = gsi_stmt (gsi);
|
|
|
|
find_func_aliases (stmt);
|
|
}
|
|
}
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
|
|
dump_constraints (dump_file, 0);
|
|
}
|
|
|
|
/* From the constraints compute the points-to sets. */
|
|
solve_constraints ();
|
|
|
|
/* Compute the points-to set for ESCAPED used for call-clobber analysis. */
|
|
find_what_var_points_to (get_varinfo (escaped_id),
|
|
&cfun->gimple_df->escaped);
|
|
|
|
/* Make sure the ESCAPED solution (which is used as placeholder in
|
|
other solutions) does not reference itself. This simplifies
|
|
points-to solution queries. */
|
|
cfun->gimple_df->escaped.escaped = 0;
|
|
|
|
/* Mark escaped HEAP variables as global. */
|
|
FOR_EACH_VEC_ELT (varinfo_t, varmap, i, vi)
|
|
if (vi->is_heap_var
|
|
&& !vi->is_global_var)
|
|
DECL_EXTERNAL (vi->decl) = vi->is_global_var
|
|
= pt_solution_includes (&cfun->gimple_df->escaped, vi->decl);
|
|
|
|
/* Compute the points-to sets for pointer SSA_NAMEs. */
|
|
for (i = 0; i < num_ssa_names; ++i)
|
|
{
|
|
tree ptr = ssa_name (i);
|
|
if (ptr
|
|
&& POINTER_TYPE_P (TREE_TYPE (ptr)))
|
|
find_what_p_points_to (ptr);
|
|
}
|
|
|
|
/* Compute the call-used/clobbered sets. */
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
gimple_stmt_iterator gsi;
|
|
|
|
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
|
{
|
|
gimple stmt = gsi_stmt (gsi);
|
|
struct pt_solution *pt;
|
|
if (!is_gimple_call (stmt))
|
|
continue;
|
|
|
|
pt = gimple_call_use_set (stmt);
|
|
if (gimple_call_flags (stmt) & ECF_CONST)
|
|
memset (pt, 0, sizeof (struct pt_solution));
|
|
else if ((vi = lookup_call_use_vi (stmt)) != NULL)
|
|
{
|
|
find_what_var_points_to (vi, pt);
|
|
/* Escaped (and thus nonlocal) variables are always
|
|
implicitly used by calls. */
|
|
/* ??? ESCAPED can be empty even though NONLOCAL
|
|
always escaped. */
|
|
pt->nonlocal = 1;
|
|
pt->escaped = 1;
|
|
}
|
|
else
|
|
{
|
|
/* If there is nothing special about this call then
|
|
we have made everything that is used also escape. */
|
|
*pt = cfun->gimple_df->escaped;
|
|
pt->nonlocal = 1;
|
|
}
|
|
|
|
pt = gimple_call_clobber_set (stmt);
|
|
if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
|
|
memset (pt, 0, sizeof (struct pt_solution));
|
|
else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
|
|
{
|
|
find_what_var_points_to (vi, pt);
|
|
/* Escaped (and thus nonlocal) variables are always
|
|
implicitly clobbered by calls. */
|
|
/* ??? ESCAPED can be empty even though NONLOCAL
|
|
always escaped. */
|
|
pt->nonlocal = 1;
|
|
pt->escaped = 1;
|
|
}
|
|
else
|
|
{
|
|
/* If there is nothing special about this call then
|
|
we have made everything that is used also escape. */
|
|
*pt = cfun->gimple_df->escaped;
|
|
pt->nonlocal = 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
timevar_pop (TV_TREE_PTA);
|
|
}
|
|
|
|
|
|
/* Delete created points-to sets. */
|
|
|
|
static void
|
|
delete_points_to_sets (void)
|
|
{
|
|
unsigned int i;
|
|
|
|
htab_delete (shared_bitmap_table);
|
|
if (dump_file && (dump_flags & TDF_STATS))
|
|
fprintf (dump_file, "Points to sets created:%d\n",
|
|
stats.points_to_sets_created);
|
|
|
|
pointer_map_destroy (vi_for_tree);
|
|
pointer_map_destroy (call_stmt_vars);
|
|
bitmap_obstack_release (&pta_obstack);
|
|
VEC_free (constraint_t, heap, constraints);
|
|
|
|
for (i = 0; i < graph->size; i++)
|
|
VEC_free (constraint_t, heap, graph->complex[i]);
|
|
free (graph->complex);
|
|
|
|
free (graph->rep);
|
|
free (graph->succs);
|
|
free (graph->pe);
|
|
free (graph->pe_rep);
|
|
free (graph->indirect_cycles);
|
|
free (graph);
|
|
|
|
VEC_free (varinfo_t, heap, varmap);
|
|
free_alloc_pool (variable_info_pool);
|
|
free_alloc_pool (constraint_pool);
|
|
|
|
obstack_free (&fake_var_decl_obstack, NULL);
|
|
}
|
|
|
|
|
|
/* Compute points-to information for every SSA_NAME pointer in the
|
|
current function and compute the transitive closure of escaped
|
|
variables to re-initialize the call-clobber states of local variables. */
|
|
|
|
unsigned int
|
|
compute_may_aliases (void)
|
|
{
|
|
if (cfun->gimple_df->ipa_pta)
|
|
{
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "\nNot re-computing points-to information "
|
|
"because IPA points-to information is available.\n\n");
|
|
|
|
/* But still dump what we have remaining it. */
|
|
dump_alias_info (dump_file);
|
|
|
|
if (dump_flags & TDF_DETAILS)
|
|
dump_referenced_vars (dump_file);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* For each pointer P_i, determine the sets of variables that P_i may
|
|
point-to. Compute the reachability set of escaped and call-used
|
|
variables. */
|
|
compute_points_to_sets ();
|
|
|
|
/* Debugging dumps. */
|
|
if (dump_file)
|
|
{
|
|
dump_alias_info (dump_file);
|
|
|
|
if (dump_flags & TDF_DETAILS)
|
|
dump_referenced_vars (dump_file);
|
|
}
|
|
|
|
/* Deallocate memory used by aliasing data structures and the internal
|
|
points-to solution. */
|
|
delete_points_to_sets ();
|
|
|
|
gcc_assert (!need_ssa_update_p (cfun));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool
|
|
gate_tree_pta (void)
|
|
{
|
|
return flag_tree_pta;
|
|
}
|
|
|
|
/* A dummy pass to cause points-to information to be computed via
|
|
TODO_rebuild_alias. */
|
|
|
|
struct gimple_opt_pass pass_build_alias =
|
|
{
|
|
{
|
|
GIMPLE_PASS,
|
|
"alias", /* name */
|
|
gate_tree_pta, /* gate */
|
|
NULL, /* execute */
|
|
NULL, /* sub */
|
|
NULL, /* next */
|
|
0, /* static_pass_number */
|
|
TV_NONE, /* tv_id */
|
|
PROP_cfg | PROP_ssa, /* properties_required */
|
|
0, /* properties_provided */
|
|
0, /* properties_destroyed */
|
|
0, /* todo_flags_start */
|
|
TODO_rebuild_alias /* todo_flags_finish */
|
|
}
|
|
};
|
|
|
|
/* A dummy pass to cause points-to information to be computed via
|
|
TODO_rebuild_alias. */
|
|
|
|
struct gimple_opt_pass pass_build_ealias =
|
|
{
|
|
{
|
|
GIMPLE_PASS,
|
|
"ealias", /* name */
|
|
gate_tree_pta, /* gate */
|
|
NULL, /* execute */
|
|
NULL, /* sub */
|
|
NULL, /* next */
|
|
0, /* static_pass_number */
|
|
TV_NONE, /* tv_id */
|
|
PROP_cfg | PROP_ssa, /* properties_required */
|
|
0, /* properties_provided */
|
|
0, /* properties_destroyed */
|
|
0, /* todo_flags_start */
|
|
TODO_rebuild_alias /* todo_flags_finish */
|
|
}
|
|
};
|
|
|
|
|
|
/* Return true if we should execute IPA PTA. */
|
|
static bool
|
|
gate_ipa_pta (void)
|
|
{
|
|
return (optimize
|
|
&& flag_ipa_pta
|
|
/* Don't bother doing anything if the program has errors. */
|
|
&& !seen_error ());
|
|
}
|
|
|
|
/* IPA PTA solutions for ESCAPED. */
|
|
struct pt_solution ipa_escaped_pt
|
|
= { true, false, false, false, false, false, NULL };
|
|
|
|
/* Associate node with varinfo DATA. Worker for
|
|
cgraph_for_node_and_aliases. */
|
|
static bool
|
|
associate_varinfo_to_alias (struct cgraph_node *node, void *data)
|
|
{
|
|
if (node->alias || node->thunk.thunk_p)
|
|
insert_vi_for_tree (node->decl, (varinfo_t)data);
|
|
return false;
|
|
}
|
|
|
|
/* Execute the driver for IPA PTA. */
|
|
static unsigned int
|
|
ipa_pta_execute (void)
|
|
{
|
|
struct cgraph_node *node;
|
|
struct varpool_node *var;
|
|
int from;
|
|
|
|
in_ipa_mode = 1;
|
|
|
|
init_alias_vars ();
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
dump_cgraph (dump_file);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
/* Build the constraints. */
|
|
for (node = cgraph_nodes; node; node = node->next)
|
|
{
|
|
varinfo_t vi;
|
|
/* Nodes without a body are not interesting. Especially do not
|
|
visit clones at this point for now - we get duplicate decls
|
|
there for inline clones at least. */
|
|
if (!cgraph_function_with_gimple_body_p (node))
|
|
continue;
|
|
|
|
gcc_assert (!node->clone_of);
|
|
|
|
vi = create_function_info_for (node->decl,
|
|
alias_get_name (node->decl));
|
|
cgraph_for_node_and_aliases (node, associate_varinfo_to_alias, vi, true);
|
|
}
|
|
|
|
/* Create constraints for global variables and their initializers. */
|
|
for (var = varpool_nodes; var; var = var->next)
|
|
{
|
|
if (var->alias)
|
|
continue;
|
|
|
|
get_vi_for_tree (var->decl);
|
|
}
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file,
|
|
"Generating constraints for global initializers\n\n");
|
|
dump_constraints (dump_file, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
from = VEC_length (constraint_t, constraints);
|
|
|
|
for (node = cgraph_nodes; node; node = node->next)
|
|
{
|
|
struct function *func;
|
|
basic_block bb;
|
|
tree old_func_decl;
|
|
|
|
/* Nodes without a body are not interesting. */
|
|
if (!cgraph_function_with_gimple_body_p (node))
|
|
continue;
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file,
|
|
"Generating constraints for %s", cgraph_node_name (node));
|
|
if (DECL_ASSEMBLER_NAME_SET_P (node->decl))
|
|
fprintf (dump_file, " (%s)",
|
|
IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->decl)));
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
func = DECL_STRUCT_FUNCTION (node->decl);
|
|
old_func_decl = current_function_decl;
|
|
push_cfun (func);
|
|
current_function_decl = node->decl;
|
|
|
|
/* For externally visible or attribute used annotated functions use
|
|
local constraints for their arguments.
|
|
For local functions we see all callers and thus do not need initial
|
|
constraints for parameters. */
|
|
if (node->reachable_from_other_partition
|
|
|| node->local.externally_visible
|
|
|| node->needed)
|
|
{
|
|
intra_create_variable_infos ();
|
|
|
|
/* We also need to make function return values escape. Nothing
|
|
escapes by returning from main though. */
|
|
if (!MAIN_NAME_P (DECL_NAME (node->decl)))
|
|
{
|
|
varinfo_t fi, rvi;
|
|
fi = lookup_vi_for_tree (node->decl);
|
|
rvi = first_vi_for_offset (fi, fi_result);
|
|
if (rvi && rvi->offset == fi_result)
|
|
{
|
|
struct constraint_expr includes;
|
|
struct constraint_expr var;
|
|
includes.var = escaped_id;
|
|
includes.offset = 0;
|
|
includes.type = SCALAR;
|
|
var.var = rvi->id;
|
|
var.offset = 0;
|
|
var.type = SCALAR;
|
|
process_constraint (new_constraint (includes, var));
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Build constriants for the function body. */
|
|
FOR_EACH_BB_FN (bb, func)
|
|
{
|
|
gimple_stmt_iterator gsi;
|
|
|
|
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
|
|
gsi_next (&gsi))
|
|
{
|
|
gimple phi = gsi_stmt (gsi);
|
|
|
|
if (is_gimple_reg (gimple_phi_result (phi)))
|
|
find_func_aliases (phi);
|
|
}
|
|
|
|
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
|
{
|
|
gimple stmt = gsi_stmt (gsi);
|
|
|
|
find_func_aliases (stmt);
|
|
find_func_clobbers (stmt);
|
|
}
|
|
}
|
|
|
|
current_function_decl = old_func_decl;
|
|
pop_cfun ();
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "\n");
|
|
dump_constraints (dump_file, from);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
from = VEC_length (constraint_t, constraints);
|
|
}
|
|
|
|
/* From the constraints compute the points-to sets. */
|
|
solve_constraints ();
|
|
|
|
/* Compute the global points-to sets for ESCAPED.
|
|
??? Note that the computed escape set is not correct
|
|
for the whole unit as we fail to consider graph edges to
|
|
externally visible functions. */
|
|
find_what_var_points_to (get_varinfo (escaped_id), &ipa_escaped_pt);
|
|
|
|
/* Make sure the ESCAPED solution (which is used as placeholder in
|
|
other solutions) does not reference itself. This simplifies
|
|
points-to solution queries. */
|
|
ipa_escaped_pt.ipa_escaped = 0;
|
|
|
|
/* Assign the points-to sets to the SSA names in the unit. */
|
|
for (node = cgraph_nodes; node; node = node->next)
|
|
{
|
|
tree ptr;
|
|
struct function *fn;
|
|
unsigned i;
|
|
varinfo_t fi;
|
|
basic_block bb;
|
|
struct pt_solution uses, clobbers;
|
|
struct cgraph_edge *e;
|
|
|
|
/* Nodes without a body are not interesting. */
|
|
if (!cgraph_function_with_gimple_body_p (node))
|
|
continue;
|
|
|
|
fn = DECL_STRUCT_FUNCTION (node->decl);
|
|
|
|
/* Compute the points-to sets for pointer SSA_NAMEs. */
|
|
FOR_EACH_VEC_ELT (tree, fn->gimple_df->ssa_names, i, ptr)
|
|
{
|
|
if (ptr
|
|
&& POINTER_TYPE_P (TREE_TYPE (ptr)))
|
|
find_what_p_points_to (ptr);
|
|
}
|
|
|
|
/* Compute the call-use and call-clobber sets for all direct calls. */
|
|
fi = lookup_vi_for_tree (node->decl);
|
|
gcc_assert (fi->is_fn_info);
|
|
find_what_var_points_to (first_vi_for_offset (fi, fi_clobbers),
|
|
&clobbers);
|
|
find_what_var_points_to (first_vi_for_offset (fi, fi_uses), &uses);
|
|
for (e = node->callers; e; e = e->next_caller)
|
|
{
|
|
if (!e->call_stmt)
|
|
continue;
|
|
|
|
*gimple_call_clobber_set (e->call_stmt) = clobbers;
|
|
*gimple_call_use_set (e->call_stmt) = uses;
|
|
}
|
|
|
|
/* Compute the call-use and call-clobber sets for indirect calls
|
|
and calls to external functions. */
|
|
FOR_EACH_BB_FN (bb, fn)
|
|
{
|
|
gimple_stmt_iterator gsi;
|
|
|
|
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
|
{
|
|
gimple stmt = gsi_stmt (gsi);
|
|
struct pt_solution *pt;
|
|
varinfo_t vi;
|
|
tree decl;
|
|
|
|
if (!is_gimple_call (stmt))
|
|
continue;
|
|
|
|
/* Handle direct calls to external functions. */
|
|
decl = gimple_call_fndecl (stmt);
|
|
if (decl
|
|
&& (!(fi = lookup_vi_for_tree (decl))
|
|
|| !fi->is_fn_info))
|
|
{
|
|
pt = gimple_call_use_set (stmt);
|
|
if (gimple_call_flags (stmt) & ECF_CONST)
|
|
memset (pt, 0, sizeof (struct pt_solution));
|
|
else if ((vi = lookup_call_use_vi (stmt)) != NULL)
|
|
{
|
|
find_what_var_points_to (vi, pt);
|
|
/* Escaped (and thus nonlocal) variables are always
|
|
implicitly used by calls. */
|
|
/* ??? ESCAPED can be empty even though NONLOCAL
|
|
always escaped. */
|
|
pt->nonlocal = 1;
|
|
pt->ipa_escaped = 1;
|
|
}
|
|
else
|
|
{
|
|
/* If there is nothing special about this call then
|
|
we have made everything that is used also escape. */
|
|
*pt = ipa_escaped_pt;
|
|
pt->nonlocal = 1;
|
|
}
|
|
|
|
pt = gimple_call_clobber_set (stmt);
|
|
if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
|
|
memset (pt, 0, sizeof (struct pt_solution));
|
|
else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
|
|
{
|
|
find_what_var_points_to (vi, pt);
|
|
/* Escaped (and thus nonlocal) variables are always
|
|
implicitly clobbered by calls. */
|
|
/* ??? ESCAPED can be empty even though NONLOCAL
|
|
always escaped. */
|
|
pt->nonlocal = 1;
|
|
pt->ipa_escaped = 1;
|
|
}
|
|
else
|
|
{
|
|
/* If there is nothing special about this call then
|
|
we have made everything that is used also escape. */
|
|
*pt = ipa_escaped_pt;
|
|
pt->nonlocal = 1;
|
|
}
|
|
}
|
|
|
|
/* Handle indirect calls. */
|
|
if (!decl
|
|
&& (fi = get_fi_for_callee (stmt)))
|
|
{
|
|
/* We need to accumulate all clobbers/uses of all possible
|
|
callees. */
|
|
fi = get_varinfo (find (fi->id));
|
|
/* If we cannot constrain the set of functions we'll end up
|
|
calling we end up using/clobbering everything. */
|
|
if (bitmap_bit_p (fi->solution, anything_id)
|
|
|| bitmap_bit_p (fi->solution, nonlocal_id)
|
|
|| bitmap_bit_p (fi->solution, escaped_id))
|
|
{
|
|
pt_solution_reset (gimple_call_clobber_set (stmt));
|
|
pt_solution_reset (gimple_call_use_set (stmt));
|
|
}
|
|
else
|
|
{
|
|
bitmap_iterator bi;
|
|
unsigned i;
|
|
struct pt_solution *uses, *clobbers;
|
|
|
|
uses = gimple_call_use_set (stmt);
|
|
clobbers = gimple_call_clobber_set (stmt);
|
|
memset (uses, 0, sizeof (struct pt_solution));
|
|
memset (clobbers, 0, sizeof (struct pt_solution));
|
|
EXECUTE_IF_SET_IN_BITMAP (fi->solution, 0, i, bi)
|
|
{
|
|
struct pt_solution sol;
|
|
|
|
vi = get_varinfo (i);
|
|
if (!vi->is_fn_info)
|
|
{
|
|
/* ??? We could be more precise here? */
|
|
uses->nonlocal = 1;
|
|
uses->ipa_escaped = 1;
|
|
clobbers->nonlocal = 1;
|
|
clobbers->ipa_escaped = 1;
|
|
continue;
|
|
}
|
|
|
|
if (!uses->anything)
|
|
{
|
|
find_what_var_points_to
|
|
(first_vi_for_offset (vi, fi_uses), &sol);
|
|
pt_solution_ior_into (uses, &sol);
|
|
}
|
|
if (!clobbers->anything)
|
|
{
|
|
find_what_var_points_to
|
|
(first_vi_for_offset (vi, fi_clobbers), &sol);
|
|
pt_solution_ior_into (clobbers, &sol);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
fn->gimple_df->ipa_pta = true;
|
|
}
|
|
|
|
delete_points_to_sets ();
|
|
|
|
in_ipa_mode = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct simple_ipa_opt_pass pass_ipa_pta =
|
|
{
|
|
{
|
|
SIMPLE_IPA_PASS,
|
|
"pta", /* name */
|
|
gate_ipa_pta, /* gate */
|
|
ipa_pta_execute, /* execute */
|
|
NULL, /* sub */
|
|
NULL, /* next */
|
|
0, /* static_pass_number */
|
|
TV_IPA_PTA, /* tv_id */
|
|
0, /* properties_required */
|
|
0, /* properties_provided */
|
|
0, /* properties_destroyed */
|
|
0, /* todo_flags_start */
|
|
TODO_update_ssa /* todo_flags_finish */
|
|
}
|
|
};
|