/* Tree based points-to analysis
- Copyright (C) 2005 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
Contributed by Daniel Berlin <dberlin@dberlin.org>
-This file is part of GCC.
+ This file is part of GCC.
-GCC is free software; you can redistribute it and/or modify
-under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
+ GCC is free software; you can redistribute it and/or modify
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
-GCC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+ GCC is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
-You should have received a copy of the GNU General Public License
-along with GCC; if not, write to the Free Software
-Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
-*/
+ You should have received a copy of the GNU General Public License
+ along with GCC; see the file COPYING3. If not see
+ <http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "output.h"
-#include "errors.h"
-#include "diagnostic.h"
#include "tree.h"
-#include "c-common.h"
#include "tree-flow.h"
#include "tree-inline.h"
-#include "varray.h"
-#include "c-tree.h"
-#include "tree-gimple.h"
+#include "diagnostic.h"
+#include "toplev.h"
+#include "gimple.h"
#include "hashtab.h"
#include "function.h"
#include "cgraph.h"
#include "alloc-pool.h"
#include "splay-tree.h"
#include "params.h"
-#include "tree-ssa-structalias.h"
#include "cgraph.h"
+#include "alias.h"
+#include "pointer-set.h"
/* The idea behind this analyzer is to generate set constraints from the
program, then solve the resulting constraints in order to generate the
- points-to sets.
+ points-to sets.
Set constraints are a way of modeling program analysis problems that
involve sets. They consist of an inclusion constraint language,
Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
of C Code in a Second" by ""Nevin Heintze and Olivier Tardieu" at
- http://citeseer.ist.psu.edu/heintze01ultrafast.html
+ http://citeseer.ist.psu.edu/heintze01ultrafast.html
+
+ There are three types of real constraint expressions, DEREF,
+ ADDRESSOF, and SCALAR. Each constraint expression consists
+ of a constraint type, a variable, and an offset.
- There are three types of constraint expressions, DEREF, ADDRESSOF, and
- SCALAR. Each constraint expression consists of a constraint type,
- a variable, and an offset.
-
SCALAR is a constraint expression type used to represent x, whether
it appears on the LHS or the RHS of a statement.
DEREF is a constraint expression type used to represent *x, whether
- it appears on the LHS or the RHS of a statement.
+ it appears on the LHS or the RHS of a statement.
ADDRESSOF is a constraint expression used to represent &x, whether
it appears on the LHS or the RHS of a statement.
-
+
Each pointer variable in the program is assigned an integer id, and
each field of a structure variable is assigned an integer id as well.
-
+
Structure variables are linked to their list of fields through a "next
field" in each variable that points to the next field in offset
- order.
- Each variable for a structure field has
+ order.
+ Each variable for a structure field has
1. "size", that tells the size in bits of that field.
2. "fullsize, that tells the size in bits of the entire structure.
3. "offset", that tells the offset in bits from the beginning of the
structure to this field.
- Thus,
+ Thus,
struct f
{
int a;
foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
bar -> id 3, size 32, offset 0, fullsize 32, next NULL
-
+
In order to solve the system of set constraints, the following is
done:
1. Each constraint variable x has a solution set associated with it,
Sol(x).
-
+
2. Constraints are separated into direct, copy, and complex.
Direct constraints are ADDRESSOF constraints that require no extra
processing, such as P = &Q
Copy constraints are those of the form P = Q.
- Complex constraints are all the constraints involving dereferences.
-
+ Complex constraints are all the constraints involving dereferences
+ and offsets (including offsetted copies).
+
3. All direct constraints of the form P = &Q are processed, such
- that Q is added to Sol(P)
+ that Q is added to Sol(P)
4. All complex constraints for a given constraint variable are stored in a
- linked list attached to that variable's node.
+ linked list attached to that variable's node.
5. A directed graph is built out of the copy constraints. Each
- constraint variable is a node in the graph, and an edge from
+ constraint variable is a node in the graph, and an edge from
Q to P is added for each copy constraint of the form P = Q
-
+
6. The graph is then walked, and solution sets are
propagated along the copy edges, such that an edge from Q to P
causes Sol(P) <- Sol(P) union Sol(Q).
-
+
7. As we visit each node, all complex constraints associated with
that node are processed by adding appropriate copy edges to the graph, or the
- appropriate variables to the solution set.
+ appropriate variables to the solution set.
8. The process of walking the graph is iterated until no solution
sets change.
Prior to walking the graph in steps 6 and 7, We perform static
- cycle elimination on the constraint graph, as well
+ cycle elimination on the constraint graph, as well
as off-line variable substitution.
-
+
TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
on and turned into anything), but isn't. You can just see what offset
inside the pointed-to struct it's going to access.
-
+
TODO: Constant bounded arrays can be handled as if they were structs of the
- same number of elements.
+ same number of elements.
TODO: Modeling heap and incoming pointers becomes much better if we
add fields to them as we discover them, which we could do.
TODO: We could handle unions, but to be honest, it's probably not
worth the pain or slowdown. */
-static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
- htab_t heapvar_for_stmt;
+/* IPA-PTA optimizations possible.
+
+ When the indirect function called is ANYTHING we can add disambiguation
+ based on the function signatures (or simply the parameter count which
+ is the varinfo size). We also do not need to consider functions that
+ do not have their address taken.
+
+ The is_global_var bit which marks escape points is overly conservative
+ in IPA mode. Split it to is_escape_point and is_global_var - only
+ externally visible globals are escape points in IPA mode. This is
+ also needed to fix the pt_solution_includes_global predicate
+ (and thus ptr_deref_may_alias_global_p).
+
+ The way we introduce DECL_PT_UID to avoid fixing up all points-to
+ sets in the translation unit when we copy a DECL during inlining
+ pessimizes precision. The advantage is that the DECL_PT_UID keeps
+ compile-time and memory usage overhead low - the points-to sets
+ do not grow or get unshared as they would during a fixup phase.
+ An alternative solution is to delay IPA PTA until after all
+ inlining transformations have been applied.
+
+ The way we propagate clobber/use information isn't optimized.
+ It should use a new complex constraint that properly filters
+ out local variables of the callee (though that would make
+ the sets invalid after inlining). OTOH we might as well
+ admit defeat to WHOPR and simply do all the clobber/use analysis
+ and propagation after PTA finished but before we threw away
+ points-to information for memory variables. WHOPR and PTA
+ do not play along well anyway - the whole constraint solving
+ would need to be done in WPA phase and it will be very interesting
+ to apply the results to local SSA names during LTRANS phase.
+
+ We probably should compute a per-function unit-ESCAPE solution
+ propagating it simply like the clobber / uses solutions. The
+ solution can go alongside the non-IPA espaced solution and be
+ used to query which vars escape the unit through a function.
+
+ We never put function decls in points-to sets so we do not
+ keep the set of called functions for indirect calls.
+
+ And probably more. */
+
+static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
+htab_t heapvar_for_stmt;
+
static bool use_field_sensitive = true;
static int in_ipa_mode = 0;
+
+/* Used for predecessor bitmaps. */
static bitmap_obstack predbitmap_obstack;
-static bitmap_obstack ptabitmap_obstack;
+
+/* Used for points-to sets. */
+static bitmap_obstack pta_obstack;
+
+/* Used for oldsolution members of variables. */
+static bitmap_obstack oldpta_obstack;
+
+/* Used for per-solver-iteration bitmaps. */
static bitmap_obstack iteration_obstack;
static unsigned int create_variable_info_for (tree, const char *);
-static void build_constraint_graph (void);
+typedef struct constraint_graph *constraint_graph_t;
+static void unify_nodes (constraint_graph_t, unsigned int, unsigned int, bool);
+
+struct constraint;
+typedef struct constraint *constraint_t;
DEF_VEC_P(constraint_t);
DEF_VEC_ALLOC_P(constraint_t,heap);
static struct constraint_stats
{
unsigned int total_vars;
- unsigned int collapsed_vars;
+ unsigned int nonpointer_vars;
unsigned int unified_vars_static;
unsigned int unified_vars_dynamic;
unsigned int iterations;
unsigned int num_edges;
+ unsigned int num_implicit_edges;
+ unsigned int points_to_sets_created;
} stats;
struct variable_info
/* ID of this variable */
unsigned int id;
- /* Name of this variable */
- const char *name;
+ /* True if this is a variable created by the constraint analysis, such as
+ heap variables and constraints we had to break up. */
+ unsigned int is_artificial_var : 1;
- /* Tree that this variable is associated with. */
- tree decl;
+ /* True if this is a special variable whose solution set should not be
+ changed. */
+ unsigned int is_special_var : 1;
- /* Offset of this variable, in bits, from the base variable */
- unsigned HOST_WIDE_INT offset;
+ /* True for variables whose size is not known or variable. */
+ unsigned int is_unknown_size_var : 1;
- /* Size of the variable, in bits. */
- unsigned HOST_WIDE_INT size;
+ /* True for (sub-)fields that represent a whole variable. */
+ unsigned int is_full_var : 1;
- /* Full size of the base variable, in bits. */
- unsigned HOST_WIDE_INT fullsize;
+ /* True if this is a heap variable. */
+ unsigned int is_heap_var : 1;
- /* A link to the variable for the next field in this structure. */
- struct variable_info *next;
+ /* True if this is a variable tracking a restrict pointer source. */
+ unsigned int is_restrict_var : 1;
- /* Node in the graph that represents the constraints and points-to
- solution for the variable. */
- unsigned int node;
+ /* True if this field may contain pointers. */
+ unsigned int may_have_pointers : 1;
- /* True if the address of this variable is taken. Needed for
- variable substitution. */
- unsigned int address_taken:1;
+ /* True if this field has only restrict qualified pointers. */
+ unsigned int only_restrict_pointers : 1;
- /* True if this variable is the target of a dereference. Needed for
- variable substitution. */
- unsigned int indirect_target:1;
+ /* True if this represents a global variable. */
+ unsigned int is_global_var : 1;
- /* True if this is a variable created by the constraint analysis, such as
- heap variables and constraints we had to break up. */
- unsigned int is_artificial_var:1;
-
- /* True if this is a special variable whose solution set should not be
- changed. */
- unsigned int is_special_var:1;
+ /* True if this represents a IPA function info. */
+ unsigned int is_fn_info : 1;
- /* True for variables whose size is not known or variable. */
- unsigned int is_unknown_size_var:1;
+ /* A link to the variable for the next field in this structure. */
+ struct variable_info *next;
+
+ /* Offset of this variable, in bits, from the base variable */
+ unsigned HOST_WIDE_INT offset;
+
+ /* Size of the variable, in bits. */
+ unsigned HOST_WIDE_INT size;
- /* True for variables that have unions somewhere in them. */
- unsigned int has_union:1;
+ /* Full size of the base variable, in bits. */
+ unsigned HOST_WIDE_INT fullsize;
- /* True if this is a heap variable. */
- unsigned int is_heap_var:1;
+ /* Name of this variable */
+ const char *name;
+
+ /* Tree that this variable is associated with. */
+ tree decl;
/* Points-to set for this variable. */
bitmap solution;
- /* Variable ids represented by this node. */
- bitmap variables;
-
- /* Vector of complex constraints for this node. Complex
- constraints are those involving dereferences. */
- VEC(constraint_t,heap) *complex;
-
- /* Variable id this was collapsed to due to type unsafety.
- This should be unused completely after build_constraint_graph, or
- something is broken. */
- struct variable_info *collapsed_to;
+ /* Old points-to set for this variable. */
+ bitmap oldsolution;
};
typedef struct variable_info *varinfo_t;
static varinfo_t first_vi_for_offset (varinfo_t, unsigned HOST_WIDE_INT);
+static varinfo_t first_or_preceding_vi_for_offset (varinfo_t,
+ unsigned HOST_WIDE_INT);
+static varinfo_t lookup_vi_for_tree (tree);
/* Pool of variable info structures. */
static alloc_pool variable_info_pool;
DEF_VEC_ALLOC_P(varinfo_t, heap);
-/* Table of variable info structures for constraint variables. Indexed directly
- by variable info id. */
+/* Table of variable info structures for constraint variables.
+ Indexed directly by variable info id. */
static VEC(varinfo_t,heap) *varmap;
/* Return the varmap element N */
static inline varinfo_t
get_varinfo (unsigned int n)
{
- return VEC_index(varinfo_t, varmap, n);
+ return VEC_index (varinfo_t, varmap, n);
}
-/* Return the varmap element N, following the collapsed_to link. */
+/* Static IDs for the special variables. */
+enum { nothing_id = 0, anything_id = 1, readonly_id = 2,
+ escaped_id = 3, nonlocal_id = 4,
+ storedanything_id = 5, integer_id = 6 };
-static inline varinfo_t
-get_varinfo_fc (unsigned int n)
-{
- varinfo_t v = VEC_index(varinfo_t, varmap, n);
+struct GTY(()) heapvar_map {
+ struct tree_map map;
+ unsigned HOST_WIDE_INT offset;
+};
- if (v->collapsed_to)
- return v->collapsed_to;
- return v;
+static int
+heapvar_map_eq (const void *p1, const void *p2)
+{
+ const struct heapvar_map *h1 = (const struct heapvar_map *)p1;
+ const struct heapvar_map *h2 = (const struct heapvar_map *)p2;
+ return (h1->map.base.from == h2->map.base.from
+ && h1->offset == h2->offset);
}
-/* Variable that represents the unknown pointer. */
-static varinfo_t var_anything;
-static tree anything_tree;
-static unsigned int anything_id;
-
-/* Variable that represents the NULL pointer. */
-static varinfo_t var_nothing;
-static tree nothing_tree;
-static unsigned int nothing_id;
-
-/* Variable that represents read only memory. */
-static varinfo_t var_readonly;
-static tree readonly_tree;
-static unsigned int readonly_id;
-
-/* Variable that represents integers. This is used for when people do things
- like &0->a.b. */
-static varinfo_t var_integer;
-static tree integer_tree;
-static unsigned int integer_id;
-
+static unsigned int
+heapvar_map_hash (struct heapvar_map *h)
+{
+ return iterative_hash_host_wide_int (h->offset,
+ htab_hash_pointer (h->map.base.from));
+}
/* Lookup a heap var for FROM, and return it if we find one. */
-static tree
-heapvar_lookup (tree from)
+static tree
+heapvar_lookup (tree from, unsigned HOST_WIDE_INT offset)
{
- struct tree_map *h, in;
- in.from = from;
-
- h = htab_find_with_hash (heapvar_for_stmt, &in, htab_hash_pointer (from));
+ struct heapvar_map *h, in;
+ in.map.base.from = from;
+ in.offset = offset;
+ h = (struct heapvar_map *) htab_find_with_hash (heapvar_for_stmt, &in,
+ heapvar_map_hash (&in));
if (h)
- return h->to;
+ return h->map.to;
return NULL_TREE;
}
hashtable. */
static void
-heapvar_insert (tree from, tree to)
+heapvar_insert (tree from, unsigned HOST_WIDE_INT offset, tree to)
{
- struct tree_map *h;
+ struct heapvar_map *h;
void **loc;
- h = ggc_alloc (sizeof (struct tree_map));
- h->hash = htab_hash_pointer (from);
- h->from = from;
- h->to = to;
- loc = htab_find_slot_with_hash (heapvar_for_stmt, h, h->hash, INSERT);
- *(struct tree_map **) loc = h;
-}
+ h = GGC_NEW (struct heapvar_map);
+ h->map.base.from = from;
+ h->offset = offset;
+ h->map.hash = heapvar_map_hash (h);
+ h->map.to = to;
+ loc = htab_find_slot_with_hash (heapvar_for_stmt, h, h->map.hash, INSERT);
+ gcc_assert (*loc == NULL);
+ *(struct heapvar_map **) loc = h;
+}
/* Return a new variable info structure consisting for a variable
- named NAME, and using constraint graph node NODE. */
+ named NAME, and using constraint graph node NODE. Append it
+ to the vector of variable info structures. */
static varinfo_t
-new_var_info (tree t, unsigned int id, const char *name, unsigned int node)
+new_var_info (tree t, const char *name)
{
- varinfo_t ret = pool_alloc (variable_info_pool);
+ unsigned index = VEC_length (varinfo_t, varmap);
+ varinfo_t ret = (varinfo_t) pool_alloc (variable_info_pool);
- ret->id = id;
+ ret->id = index;
ret->name = name;
ret->decl = t;
- ret->node = node;
- ret->address_taken = false;
- ret->indirect_target = false;
- ret->is_artificial_var = false;
- ret->is_heap_var = false;
+ /* Vars without decl are artificial and do not have sub-variables. */
+ ret->is_artificial_var = (t == NULL_TREE);
ret->is_special_var = false;
ret->is_unknown_size_var = false;
- ret->has_union = false;
- ret->solution = BITMAP_ALLOC (&ptabitmap_obstack);
- ret->variables = BITMAP_ALLOC (&ptabitmap_obstack);
- ret->complex = NULL;
+ ret->is_full_var = (t == NULL_TREE);
+ ret->is_heap_var = false;
+ ret->is_restrict_var = false;
+ ret->may_have_pointers = true;
+ ret->only_restrict_pointers = false;
+ ret->is_global_var = (t == NULL_TREE);
+ ret->is_fn_info = false;
+ if (t && DECL_P (t))
+ ret->is_global_var = is_global_var (t);
+ ret->solution = BITMAP_ALLOC (&pta_obstack);
+ ret->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
ret->next = NULL;
- ret->collapsed_to = NULL;
+
+ stats.total_vars++;
+
+ VEC_safe_push (varinfo_t, heap, varmap, ret);
+
return ret;
}
+
+/* A map mapping call statements to per-stmt variables for uses
+ and clobbers specific to the call. */
+struct pointer_map_t *call_stmt_vars;
+
+/* Lookup or create the variable for the call statement CALL. */
+
+static varinfo_t
+get_call_vi (gimple call)
+{
+ void **slot_p;
+ varinfo_t vi, vi2;
+
+ slot_p = pointer_map_insert (call_stmt_vars, call);
+ if (*slot_p)
+ return (varinfo_t) *slot_p;
+
+ vi = new_var_info (NULL_TREE, "CALLUSED");
+ vi->offset = 0;
+ vi->size = 1;
+ vi->fullsize = 2;
+ vi->is_full_var = true;
+
+ vi->next = vi2 = new_var_info (NULL_TREE, "CALLCLOBBERED");
+ vi2->offset = 1;
+ vi2->size = 1;
+ vi2->fullsize = 2;
+ vi2->is_full_var = true;
+
+ *slot_p = (void *) vi;
+ return vi;
+}
+
+/* Lookup the variable for the call statement CALL representing
+ the uses. Returns NULL if there is nothing special about this call. */
+
+static varinfo_t
+lookup_call_use_vi (gimple call)
+{
+ void **slot_p;
+
+ slot_p = pointer_map_contains (call_stmt_vars, call);
+ if (slot_p)
+ return (varinfo_t) *slot_p;
+
+ return NULL;
+}
+
+/* Lookup the variable for the call statement CALL representing
+ the clobbers. Returns NULL if there is nothing special about this call. */
+
+static varinfo_t
+lookup_call_clobber_vi (gimple call)
+{
+ varinfo_t uses = lookup_call_use_vi (call);
+ if (!uses)
+ return NULL;
+
+ return uses->next;
+}
+
+/* Lookup or create the variable for the call statement CALL representing
+ the uses. */
+
+static varinfo_t
+get_call_use_vi (gimple call)
+{
+ return get_call_vi (call);
+}
+
+/* Lookup or create the variable for the call statement CALL representing
+ the clobbers. */
+
+static varinfo_t ATTRIBUTE_UNUSED
+get_call_clobber_vi (gimple call)
+{
+ return get_call_vi (call)->next;
+}
+
+
typedef enum {SCALAR, DEREF, ADDRESSOF} constraint_expr_type;
/* An expression that appears in a constraint. */
-struct constraint_expr
+struct constraint_expr
{
/* Constraint type. */
constraint_expr_type type;
IOW, in a deref constraint, we would deref, get the result set,
then add OFFSET to each member. */
- unsigned HOST_WIDE_INT offset;
+ HOST_WIDE_INT offset;
};
+/* Use 0x8000... as special unknown offset. */
+#define UNKNOWN_OFFSET ((HOST_WIDE_INT)-1 << (HOST_BITS_PER_WIDE_INT-1))
+
typedef struct constraint_expr ce_s;
DEF_VEC_O(ce_s);
DEF_VEC_ALLOC_O(ce_s, heap);
+static void get_constraint_for_1 (tree, VEC(ce_s, heap) **, bool);
static void get_constraint_for (tree, VEC(ce_s, heap) **);
static void do_deref (VEC (ce_s, heap) **);
/* Our set constraints are made up of two constraint expressions, one
- LHS, and one RHS.
+ LHS, and one RHS.
As described in the introduction, our set constraints each represent an
operation between set valued variables.
static VEC(constraint_t,heap) *constraints;
static alloc_pool constraint_pool;
-/* An edge in the weighted constraint graph. The edges are weighted,
- with a bit set in weights meaning their is an edge with that
- weight.
- We don't keep the src in the edge, because we always know what it
- is. */
+/* The constraint graph is represented as an array of bitmaps
+ containing successor nodes. */
-struct constraint_edge
+struct constraint_graph
{
- unsigned int dest;
- bitmap weights;
-};
+ /* Size of this graph, which may be different than the number of
+ nodes in the variable map. */
+ unsigned int size;
-typedef struct constraint_edge *constraint_edge_t;
-static alloc_pool constraint_edge_pool;
+ /* Explicit successors of each node. */
+ bitmap *succs;
-/* Return a new constraint edge from SRC to DEST. */
+ /* Implicit predecessors of each node (Used for variable
+ substitution). */
+ bitmap *implicit_preds;
-static constraint_edge_t
-new_constraint_edge (unsigned int dest)
-{
- constraint_edge_t ret = pool_alloc (constraint_edge_pool);
- ret->dest = dest;
- ret->weights = NULL;
- return ret;
-}
+ /* 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;
-DEF_VEC_P(constraint_edge_t);
-DEF_VEC_ALLOC_P(constraint_edge_t,heap);
+ /* 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;
+};
-/* The constraint graph is represented internally in two different
- ways. The overwhelming majority of edges in the constraint graph
- are zero weigh edges, and thus, using a vector of contrainst_edge_t
- is a waste of time and memory, since they have no weights. We
- simply use a bitmap to store the preds and succs for each node.
- The weighted edges are stored as a set of adjacency vectors, one
- per variable. succs[x] is the vector of successors for variable x,
- and preds[x] is the vector of predecessors for variable x. IOW,
- all edges are "forward" edges, which is not like our CFG. So
- remember that preds[x]->src == x, and succs[x]->src == x. */
+static constraint_graph_t graph;
-struct constraint_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)
{
- bitmap *zero_weight_succs;
- bitmap *zero_weight_preds;
- VEC(constraint_edge_t,heap) **succs;
- VEC(constraint_edge_t,heap) **preds;
-};
+ gcc_assert (node < graph->size);
+ if (graph->rep[node] != node)
+ return graph->rep[node] = find (graph->rep[node]);
+ return node;
+}
-typedef struct constraint_graph *constraint_graph_t;
+/* 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 constraint_graph_t graph;
+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
+static constraint_t
new_constraint (const struct constraint_expr lhs,
const struct constraint_expr rhs)
{
- constraint_t ret = pool_alloc (constraint_pool);
+ constraint_t ret = (constraint_t) pool_alloc (constraint_pool);
ret->lhs = lhs;
ret->rhs = rhs;
return ret;
/* Print out constraint C to FILE. */
-void
+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_fc (c->lhs.var)->name);
- if (c->lhs.offset != 0)
+ 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_fc (c->rhs.var)->name);
- if (c->rhs.offset != 0)
+ 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);
fprintf (file, "\n");
}
+
+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. */
void
/* Print out all constraints to FILE */
-void
-dump_constraints (FILE *file)
+static void
+dump_constraints (FILE *file, int from)
{
int i;
constraint_t c;
- for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
+ for (i = from; VEC_iterate (constraint_t, constraints, i, c); i++)
dump_constraint (file, c);
}
void
debug_constraints (void)
{
- dump_constraints (stderr);
+ dump_constraints (stderr, 0);
+}
+
+/* Print out to FILE the edge in the constraint graph that is created by
+ constraint c. The edge may have a label, depending on the type of
+ constraint that it represents. If complex1, e.g: a = *b, then the label
+ is "=*", if complex2, e.g: *a = b, then the label is "*=", if
+ complex with an offset, e.g: a = b + 8, then the label is "+".
+ Otherwise the edge has no label. */
+
+static void
+dump_constraint_edge (FILE *file, constraint_t c)
+{
+ if (c->rhs.type != ADDRESSOF)
+ {
+ const char *src = get_varinfo (c->rhs.var)->name;
+ const char *dst = get_varinfo (c->lhs.var)->name;
+ fprintf (file, " \"%s\" -> \"%s\" ", src, dst);
+ /* Due to preprocessing of constraints, instructions like *a = *b are
+ illegal; thus, we do not have to handle such cases. */
+ if (c->lhs.type == DEREF)
+ fprintf (file, " [ label=\"*=\" ] ;\n");
+ else if (c->rhs.type == DEREF)
+ fprintf (file, " [ label=\"=*\" ] ;\n");
+ else
+ {
+ /* We must check the case where the constraint is an offset.
+ In this case, it is treated as a complex constraint. */
+ if (c->rhs.offset != c->lhs.offset)
+ fprintf (file, " [ label=\"+\" ] ;\n");
+ else
+ fprintf (file, " ;\n");
+ }
+ }
+}
+
+/* Print the constraint graph in dot format. */
+
+static void
+dump_constraint_graph (FILE *file)
+{
+ unsigned int i=0, size;
+ constraint_t c;
+
+ /* Only print the graph if it has already been initialized: */
+ if (!graph)
+ return;
+
+ /* Print the constraints used to produce the constraint graph. The
+ constraints will be printed as comments in the dot file: */
+ fprintf (file, "\n\n/* Constraints used in the constraint graph:\n");
+ dump_constraints (file, 0);
+ fprintf (file, "*/\n");
+
+ /* Prints the header of the dot file: */
+ fprintf (file, "\n\n// The constraint graph in dot format:\n");
+ 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 in the constraint graph:\n");
+
+ /* The next lines print the nodes in the graph. In order to get the
+ number of nodes in the graph, we must choose the minimum between the
+ vector VEC (varinfo_t, varmap) and graph->size. If the graph has not
+ yet been initialized, then graph->size == 0, otherwise we must only
+ read nodes that have an entry in VEC (varinfo_t, varmap). */
+ size = VEC_length (varinfo_t, varmap);
+ size = size < graph->size ? size : graph->size;
+ for (i = 0; i < size; i++)
+ {
+ const char *name = get_varinfo (graph->rep[i])->name;
+ fprintf (file, " \"%s\" ;\n", name);
+ }
+
+ /* Go over the list of constraints printing the edges in the constraint
+ graph. */
+ fprintf (file, "\n // The constraint edges:\n");
+ for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
+ if (c)
+ dump_constraint_edge (file, c);
+
+ /* Prints the tail of the dot file. By now, only the closing bracket. */
+ fprintf (file, "}\n\n\n");
+}
+
+/* Print out the constraint graph to stderr. */
+
+void
+debug_constraint_graph (void)
+{
+ dump_constraint_graph (stderr);
}
-/* SOLVER FUNCTIONS
+/* SOLVER FUNCTIONS
The solver is a simple worklist solver, that works on the following
algorithm:
-
- sbitmap changed_nodes = all ones;
- changed_count = number of nodes;
- For each node that was already collapsed:
- changed_count--;
+
+ 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--;
}
/* 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)
+ return constraint_expr_equal (a.lhs, b.lhs)
&& constraint_expr_equal (a.rhs, b.rhs);
}
constraint_vec_find (VEC(constraint_t,heap) *vec,
struct constraint lookfor)
{
- unsigned int place;
+ unsigned int place;
constraint_t found;
if (vec == NULL)
}
}
+/* 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, unsigned HOST_WIDE_INT offset)
+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)
{
- /* If this is a properly sized variable, only add offset if it's
- less than end. Otherwise, it is globbed to a single
- variable. */
-
- if ((get_varinfo (i)->offset + offset) < get_varinfo (i)->fullsize)
- {
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (i)->offset + offset;
- varinfo_t v = first_vi_for_offset (get_varinfo (i), fieldoffset);
- if (!v)
- continue;
- bitmap_set_bit (result, v->id);
- }
- else if (get_varinfo (i)->is_artificial_var
- || get_varinfo (i)->has_union
- || get_varinfo (i)->is_unknown_size_var)
+ 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
{
- bitmap_set_bit (result, i);
+ 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_copy (set, result);
BITMAP_FREE (result);
}
process. */
static bool
-set_union_with_increment (bitmap to, bitmap from, unsigned HOST_WIDE_INT inc)
+set_union_with_increment (bitmap to, bitmap from, HOST_WIDE_INT inc)
{
if (inc == 0)
return bitmap_ior_into (to, from);
}
}
-/* Insert constraint C into the list of complex constraints for VAR. */
+/* Insert constraint C into the list of complex constraints for graph
+ node VAR. */
static void
-insert_into_complex (unsigned int var, constraint_t c)
+insert_into_complex (constraint_graph_t graph,
+ unsigned int var, constraint_t c)
{
- varinfo_t vi = get_varinfo (var);
- unsigned int place = VEC_lower_bound (constraint_t, vi->complex, c,
+ VEC (constraint_t, heap) *complex = graph->complex[var];
+ unsigned int place = VEC_lower_bound (constraint_t, complex, c,
constraint_less);
- VEC_safe_insert (constraint_t, heap, vi->complex, place, c);
-}
-
-
-/* Compare two constraint edges A and B, return true if they are equal. */
-
-static bool
-constraint_edge_equal (struct constraint_edge a, struct constraint_edge b)
-{
- return a.dest == b.dest;
-}
-
-/* Compare two constraint edges, return true if A is less than B */
-static bool
-constraint_edge_less (const constraint_edge_t a, const constraint_edge_t b)
-{
- if (a->dest < b->dest)
- return true;
- return false;
+ /* 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);
}
-/* Find the constraint edge that matches LOOKFOR, in VEC.
- Return the edge, if found, NULL otherwise. */
-
-static constraint_edge_t
-constraint_edge_vec_find (VEC(constraint_edge_t,heap) *vec,
- struct constraint_edge lookfor)
-{
- unsigned int place;
- constraint_edge_t edge = NULL;
-
- place = VEC_lower_bound (constraint_edge_t, vec, &lookfor,
- constraint_edge_less);
- if (place >= VEC_length (constraint_edge_t, vec))
- return NULL;
- edge = VEC_index (constraint_edge_t, vec, place);
- if (!constraint_edge_equal (*edge, lookfor))
- return NULL;
- return edge;
-}
/* Condense two variable nodes into a single variable node, by moving
all associated info from SRC to TO. */
-static void
-condense_varmap_nodes (unsigned int to, unsigned int src)
+static void
+merge_node_constraints (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
{
- varinfo_t tovi = get_varinfo (to);
- varinfo_t srcvi = get_varinfo (src);
unsigned int i;
constraint_t c;
- bitmap_iterator bi;
-
- /* the src node, and all its variables, are now the to node. */
- srcvi->node = to;
- EXECUTE_IF_SET_IN_BITMAP (srcvi->variables, 0, i, bi)
- get_varinfo (i)->node = to;
-
- /* Merge the src node variables and the to node variables. */
- bitmap_set_bit (tovi->variables, src);
- bitmap_ior_into (tovi->variables, srcvi->variables);
- bitmap_clear (srcvi->variables);
-
+
+ gcc_assert (find (from) == to);
+
/* Move all complex constraints from src node into to node */
- for (i = 0; VEC_iterate (constraint_t, srcvi->complex, i, c); i++)
+ for (i = 0; VEC_iterate (constraint_t, graph->complex[from], i, c); i++)
{
/* In complex constraints for node src, we may have either
- a = *src, and *src = a. */
-
+ 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
+ else if (c->lhs.type == DEREF)
c->lhs.var = to;
+ else
+ c->rhs.var = to;
}
- constraint_set_union (&tovi->complex, &srcvi->complex);
- VEC_free (constraint_t, heap, srcvi->complex);
- srcvi->complex = NULL;
+ constraint_set_union (&graph->complex[to], &graph->complex[from]);
+ VEC_free (constraint_t, heap, graph->complex[from]);
+ graph->complex[from] = NULL;
}
-/* Erase an edge from SRC to SRC from GRAPH. This routine only
- handles self-edges (e.g. an edge from a to a). */
+
+/* Remove edges involving NODE from GRAPH. */
static void
-erase_graph_self_edge (constraint_graph_t graph, unsigned int src)
+clear_edges_for_node (constraint_graph_t graph, unsigned int node)
{
- VEC(constraint_edge_t,heap) *predvec = graph->preds[src];
- VEC(constraint_edge_t,heap) *succvec = graph->succs[src];
- struct constraint_edge edge;
- unsigned int place;
-
- edge.dest = src;
-
- /* Remove from the successors. */
- place = VEC_lower_bound (constraint_edge_t, succvec, &edge,
- constraint_edge_less);
-
- /* Make sure we found the edge. */
-#ifdef ENABLE_CHECKING
- {
- constraint_edge_t tmp = VEC_index (constraint_edge_t, succvec, place);
- gcc_assert (constraint_edge_equal (*tmp, edge));
- }
-#endif
- VEC_ordered_remove (constraint_edge_t, succvec, place);
-
- /* Remove from the predecessors. */
- place = VEC_lower_bound (constraint_edge_t, predvec, &edge,
- constraint_edge_less);
-
- /* Make sure we found the edge. */
-#ifdef ENABLE_CHECKING
- {
- constraint_edge_t tmp = VEC_index (constraint_edge_t, predvec, place);
- gcc_assert (constraint_edge_equal (*tmp, edge));
- }
-#endif
- VEC_ordered_remove (constraint_edge_t, predvec, place);
+ if (graph->succs[node])
+ BITMAP_FREE (graph->succs[node]);
}
-/* Remove edges involving NODE from GRAPH. */
+/* Merge GRAPH nodes FROM and TO into node TO. */
static void
-clear_edges_for_node (constraint_graph_t graph, unsigned int node)
+merge_graph_nodes (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
{
- VEC(constraint_edge_t,heap) *succvec = graph->succs[node];
- VEC(constraint_edge_t,heap) *predvec = graph->preds[node];
- bitmap_iterator bi;
- unsigned int j;
- constraint_edge_t c = NULL;
- int i;
+ 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];
+ }
- /* Walk the successors, erase the associated preds. */
-
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->zero_weight_succs[node], 0, j, bi)
- if (j != node)
- bitmap_clear_bit (graph->zero_weight_preds[j], node);
-
- for (i = 0; VEC_iterate (constraint_edge_t, succvec, i, c); i++)
- if (c->dest != node)
- {
- unsigned int place;
- struct constraint_edge lookfor;
- constraint_edge_t result;
-
- lookfor.dest = node;
- place = VEC_lower_bound (constraint_edge_t, graph->preds[c->dest],
- &lookfor, constraint_edge_less);
- result = VEC_ordered_remove (constraint_edge_t,
- graph->preds[c->dest], place);
- pool_free (constraint_edge_pool, result);
- }
+ /* 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]);
+ }
- /* Walk the preds, erase the associated succs. */
+ clear_edges_for_node (graph, from);
+}
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->zero_weight_preds[node], 0, j, bi)
- if (j != node)
- bitmap_clear_bit (graph->zero_weight_succs[j], node);
-
- for (i =0; VEC_iterate (constraint_edge_t, predvec, i, c); i++)
- if (c->dest != node)
- {
- unsigned int place;
- struct constraint_edge lookfor;
- constraint_edge_t result;
- lookfor.dest = node;
- place = VEC_lower_bound (constraint_edge_t, graph->succs[c->dest],
- &lookfor, constraint_edge_less);
- result = VEC_ordered_remove (constraint_edge_t,
- graph->succs[c->dest], place);
- pool_free (constraint_edge_pool, result);
+/* 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 (graph->zero_weight_preds[node])
- {
- BITMAP_FREE (graph->zero_weight_preds[node]);
- graph->zero_weight_preds[node] = NULL;
- }
+ if (bitmap_set_bit (graph->implicit_preds[to], from))
+ stats.num_implicit_edges++;
+}
- if (graph->zero_weight_succs[node])
- {
- BITMAP_FREE (graph->zero_weight_succs[node]);
- graph->zero_weight_succs[node] = NULL;
- }
+/* 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. */
- VEC_free (constraint_edge_t, heap, graph->preds[node]);
- VEC_free (constraint_edge_t, heap, graph->succs[node]);
- graph->preds[node] = NULL;
- graph->succs[node] = NULL;
+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);
}
-static bool edge_added = false;
-
-/* Add edge (src, dest) to the graph. */
+/* 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 src, unsigned int dest)
+add_graph_edge (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
{
- unsigned int place;
- VEC(constraint_edge_t,heap) *vec;
- struct constraint_edge newe;
- newe.dest = dest;
-
- vec = graph->preds[src];
- place = VEC_lower_bound (constraint_edge_t, vec, &newe,
- constraint_edge_less);
- if (place == VEC_length (constraint_edge_t, vec)
- || VEC_index (constraint_edge_t, vec, place)->dest != dest)
- {
- constraint_edge_t edge = new_constraint_edge (dest);
-
- VEC_safe_insert (constraint_edge_t, heap, graph->preds[src],
- place, edge);
- edge = new_constraint_edge (src);
-
- place = VEC_lower_bound (constraint_edge_t, graph->succs[dest],
- edge, constraint_edge_less);
- VEC_safe_insert (constraint_edge_t, heap, graph->succs[dest],
- place, edge);
- edge_added = true;
- stats.num_edges++;
- return true;
+ if (to == from)
+ {
+ return false;
}
else
- return false;
+ {
+ 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 the bitmap representing the weights of edge (SRC, DEST). */
+/* Return true if {DEST.SRC} is an existing graph edge in GRAPH. */
-static bitmap *
-get_graph_weights (constraint_graph_t graph, unsigned int src,
- unsigned int dest)
+static bool
+valid_graph_edge (constraint_graph_t graph, unsigned int src,
+ unsigned int dest)
{
- constraint_edge_t edge;
- VEC(constraint_edge_t,heap) *vec;
- struct constraint_edge lookfor;
-
- lookfor.dest = dest;
-
- vec = graph->preds[src];
- edge = constraint_edge_vec_find (vec, lookfor);
- gcc_assert (edge != NULL);
- return &edge->weights;
+ return (graph->succs[dest]
+ && bitmap_bit_p (graph->succs[dest], src));
}
-/* Allocate graph weight bitmap for the edges associated with SRC and
- DEST in GRAPH. Both the pred and the succ edges share a single
- bitmap, so we need to set both edges to that bitmap. */
+/* Initialize the constraint graph structure to contain SIZE nodes. */
-static bitmap
-allocate_graph_weights (constraint_graph_t graph, unsigned int src,
- unsigned int dest)
+static void
+init_graph (unsigned int size)
{
- bitmap result;
- constraint_edge_t edge;
- VEC(constraint_edge_t,heap) *vec;
- struct constraint_edge lookfor;
-
- result = BITMAP_ALLOC (&ptabitmap_obstack);
-
- /* Set the pred weight. */
- lookfor.dest = dest;
- vec = graph->preds[src];
- edge = constraint_edge_vec_find (vec, lookfor);
- gcc_assert (edge != NULL);
- edge->weights = result;
-
- /* Set the succ weight. */
- lookfor.dest = src;
- vec = graph->succs[dest];
- edge = constraint_edge_vec_find (vec, lookfor);
- gcc_assert (edge != NULL);
- edge->weights = result;
-
- return result;
-}
+ 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);
-/* Merge GRAPH nodes FROM and TO into node TO. */
+ 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
-merge_graph_nodes (constraint_graph_t graph, unsigned int to,
- unsigned int from)
+build_pred_graph (void)
{
- VEC(constraint_edge_t,heap) *succvec = graph->succs[from];
- VEC(constraint_edge_t,heap) *predvec = graph->preds[from];
int i;
- constraint_edge_t c;
+ constraint_t c;
unsigned int j;
- bitmap_iterator bi;
-
- /* Merge all the zero weighted predecessor edges. */
- if (graph->zero_weight_preds[from])
- {
- if (!graph->zero_weight_preds[to])
- graph->zero_weight_preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
-
- EXECUTE_IF_SET_IN_BITMAP (graph->zero_weight_preds[from], 0, j, bi)
- {
- if (j != to)
- {
- bitmap_clear_bit (graph->zero_weight_succs[j], from);
- bitmap_set_bit (graph->zero_weight_succs[j], to);
- }
- }
- bitmap_ior_into (graph->zero_weight_preds[to],
- graph->zero_weight_preds[from]);
- }
- /* Merge all the zero weighted successor edges. */
- if (graph->zero_weight_succs[from])
+ 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 (!graph->zero_weight_succs[to])
- graph->zero_weight_succs[to] = BITMAP_ALLOC (&ptabitmap_obstack);
- EXECUTE_IF_SET_IN_BITMAP (graph->zero_weight_succs[from], 0, j, bi)
- {
- bitmap_clear_bit (graph->zero_weight_preds[j], from);
- bitmap_set_bit (graph->zero_weight_preds[j], to);
- }
- bitmap_ior_into (graph->zero_weight_succs[to],
- graph->zero_weight_succs[from]);
+ if (!get_varinfo (j)->is_special_var)
+ SET_BIT (graph->direct_nodes, j);
}
- /* Merge all the nonzero weighted predecessor edges. */
- for (i = 0; VEC_iterate (constraint_edge_t, predvec, i, c); i++)
- {
- unsigned int d = c->dest;
- bitmap temp;
- bitmap *weights;
+ for (j = 0; j < graph->size; j++)
+ graph->eq_rep[j] = -1;
- if (c->dest == from)
- d = to;
+ for (j = 0; j < VEC_length (varinfo_t, varmap); j++)
+ graph->indirect_cycles[j] = -1;
- add_graph_edge (graph, to, d);
+ for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
+ {
+ struct constraint_expr lhs = c->lhs;
+ struct constraint_expr rhs = c->rhs;
+ unsigned int lhsvar = lhs.var;
+ unsigned int rhsvar = rhs.var;
- temp = *(get_graph_weights (graph, from, c->dest));
- if (temp)
+ if (lhs.type == DEREF)
{
- weights = get_graph_weights (graph, to, d);
- if (!*weights)
- *weights = allocate_graph_weights (graph, to, d);
-
- bitmap_ior_into (*weights, temp);
+ /* *x = y. */
+ if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
+ add_pred_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
}
-
- }
-
- /* Merge all the nonzero weighted successor edges. */
- for (i = 0; VEC_iterate (constraint_edge_t, succvec, i, c); i++)
- {
- unsigned int d = c->dest;
- bitmap temp;
- bitmap *weights;
-
- if (c->dest == from)
- d = to;
-
- add_graph_edge (graph, d, to);
-
- temp = *(get_graph_weights (graph, c->dest, from));
- if (temp)
+ else if (rhs.type == DEREF)
{
- weights = get_graph_weights (graph, d, to);
- if (!*weights)
- *weights = allocate_graph_weights (graph, d, to);
- bitmap_ior_into (*weights, temp);
+ /* 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);
}
- }
- clear_edges_for_node (graph, from);
-}
-
-/* Add a graph edge to GRAPH, going from TO to FROM, with WEIGHT, if
- it doesn't exist in the graph already.
- Return false if the edge already existed, true otherwise. */
-
-static bool
-int_add_graph_edge (constraint_graph_t graph, unsigned int to,
- unsigned int from, unsigned HOST_WIDE_INT weight)
-{
- if (to == from && weight == 0)
- {
- return false;
- }
- else
- {
- bool r = false;
+ else if (rhs.type == ADDRESSOF)
+ {
+ varinfo_t v;
- if (weight == 0)
+ /* 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)
{
- if (!graph->zero_weight_preds[to])
- graph->zero_weight_preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
- if (!graph->zero_weight_succs[from])
- graph->zero_weight_succs[from] = BITMAP_ALLOC (&ptabitmap_obstack);
- if (!bitmap_bit_p (graph->zero_weight_succs[from], to))
- {
- edge_added = true;
- r = true;
- stats.num_edges++;
- bitmap_set_bit (graph->zero_weight_preds[to], from);
- bitmap_set_bit (graph->zero_weight_succs[from], to);
- }
+ /* 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
+ else if (lhs.offset != 0 || rhs.offset != 0)
{
- bitmap *weights;
-
- r = add_graph_edge (graph, to, from);
- weights = get_graph_weights (graph, to, from);
-
- if (!*weights)
- {
- r = true;
- *weights = allocate_graph_weights (graph, to, from);
- bitmap_set_bit (*weights, weight);
- }
- else
- {
- r |= !bitmap_bit_p (*weights, weight);
- bitmap_set_bit (*weights, weight);
- }
+ if (rhs.offset != 0)
+ RESET_BIT (graph->direct_nodes, lhs.var);
+ else if (lhs.offset != 0)
+ RESET_BIT (graph->direct_nodes, rhs.var);
}
-
- 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)
-{
- struct constraint_edge lookfor;
- lookfor.dest = src;
-
- return (graph->zero_weight_succs[dest]
- && bitmap_bit_p (graph->zero_weight_succs[dest], src))
- || constraint_edge_vec_find (graph->succs[dest], lookfor) != NULL;
-}
-
-/* Return true if {DEST, SRC} is an existing weighted graph edge (IE has
- a weight other than 0) in GRAPH. */
-static bool
-valid_weighted_graph_edge (constraint_graph_t graph, unsigned int src,
- unsigned int dest)
-{
- struct constraint_edge lookfor;
- lookfor.dest = src;
-
- return graph->preds[src]
- && constraint_edge_vec_find (graph->succs[dest], lookfor) != NULL;
-}
-
-
-/* Build the constraint graph. */
+/* Build the constraint graph, adding successor edges. */
static void
-build_constraint_graph (void)
+build_succ_graph (void)
{
- int i = 0;
+ unsigned i, t;
constraint_t c;
- graph = XNEW (struct constraint_graph);
- graph->succs = XCNEWVEC (VEC(constraint_edge_t,heap) *, VEC_length (varinfo_t, varmap) + 1);
- graph->preds = XCNEWVEC (VEC(constraint_edge_t,heap) *, VEC_length (varinfo_t, varmap) + 1);
- graph->zero_weight_succs = XCNEWVEC (bitmap, VEC_length (varinfo_t, varmap) + 1);
- graph->zero_weight_preds = XCNEWVEC (bitmap, VEC_length (varinfo_t, varmap) + 1);
-
for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
{
- struct constraint_expr lhs = c->lhs;
- struct constraint_expr rhs = c->rhs;
- unsigned int lhsvar = get_varinfo_fc (lhs.var)->id;
- unsigned int rhsvar = get_varinfo_fc (rhs.var)->id;
+ 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)
{
- /* *x = y or *x = &y (complex) */
- if (rhs.type == ADDRESSOF || rhsvar > anything_id)
- insert_into_complex (lhsvar, c);
+ if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
+ add_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
}
else if (rhs.type == DEREF)
{
- /* !special var= *y */
- if (!(get_varinfo (lhsvar)->is_special_var))
- insert_into_complex (rhsvar, c);
+ 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)
+ else if (lhsvar > anything_id
+ && lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
{
- /* Ignore 0 weighted self edges, as they can't possibly contribute
- anything */
- if (lhsvar != rhsvar || rhs.offset != 0 || lhs.offset != 0)
- {
- /* x = y (simple) */
- int_add_graph_edge (graph, lhs.var, rhs.var, rhs.offset);
- }
-
+ 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);
}
static unsigned int changed_count;
static sbitmap changed;
-DEF_VEC_I(unsigned);
-DEF_VEC_ALLOC_I(unsigned,heap);
-
-
/* Strongly Connected Component visitation info. */
struct scc_info
{
sbitmap visited;
- sbitmap in_component;
+ sbitmap deleted;
+ unsigned int *dfs;
+ unsigned int *node_mapping;
int current_index;
- unsigned int *visited_index;
VEC(unsigned,heap) *scc_stack;
- VEC(unsigned,heap) *unification_queue;
};
/* 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.
+ 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,
{
unsigned int i;
bitmap_iterator bi;
+ unsigned int my_dfs;
- gcc_assert (get_varinfo (n)->node == n);
SET_BIT (si->visited, n);
- RESET_BIT (si->in_component, n);
- si->visited_index[n] = si->current_index ++;
-
+ si->dfs[n] = si->current_index ++;
+ my_dfs = si->dfs[n];
+
/* Visit all the successors. */
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->zero_weight_succs[n], 0, i, bi)
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[n], 0, i, bi)
{
- unsigned int w = i;
+ 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);
- if (!TEST_BIT (si->in_component, w))
- {
- unsigned int t = get_varinfo (w)->node;
- unsigned int nnode = get_varinfo (n)->node;
- if (si->visited_index[t] < si->visited_index[nnode])
- get_varinfo (n)->node = t;
- }
+ {
+ 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 (get_varinfo (n)->node == n)
+ if (si->dfs[n] == my_dfs)
{
- unsigned int t = si->visited_index[n];
- SET_BIT (si->in_component, n);
- while (VEC_length (unsigned, si->scc_stack) != 0
- && t < si->visited_index[VEC_last (unsigned, si->scc_stack)])
+ if (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);
- get_varinfo (w)->node = n;
- SET_BIT (si->in_component, w);
- /* Mark this node for collapsing. */
- VEC_safe_push (unsigned, heap, si->unification_queue, w);
- }
- }
- else
- VEC_safe_push (unsigned, heap, si->scc_stack, n);
-}
+ bitmap scc = BITMAP_ALLOC (NULL);
+ unsigned int lowest_node;
+ bitmap_iterator bi;
+ bitmap_set_bit (scc, n);
-/* Collapse two variables into one variable. */
+ 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);
-static void
-collapse_nodes (constraint_graph_t graph, unsigned int to, unsigned int from)
-{
- bitmap tosol, fromsol;
+ bitmap_set_bit (scc, w);
+ }
- condense_varmap_nodes (to, from);
- tosol = get_varinfo (to)->solution;
- fromsol = get_varinfo (from)->solution;
- bitmap_ior_into (tosol, fromsol);
- merge_graph_nodes (graph, to, from);
+ lowest_node = bitmap_first_set_bit (scc);
+ gcc_assert (lowest_node < FIRST_REF_NODE);
- if (valid_graph_edge (graph, to, to))
- {
- if (graph->zero_weight_preds[to])
- {
- bitmap_clear_bit (graph->zero_weight_preds[to], to);
- bitmap_clear_bit (graph->zero_weight_succs[to], to);
- }
- if (valid_weighted_graph_edge (graph, to, to))
- {
- bitmap weights = *(get_graph_weights (graph, to, to));
- if (!weights || bitmap_empty_p (weights))
- erase_graph_self_edge (graph, to);
+ /* 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);
}
- BITMAP_FREE (fromsol);
- get_varinfo (to)->address_taken |= get_varinfo (from)->address_taken;
- get_varinfo (to)->indirect_target |= get_varinfo (from)->indirect_target;
+ else
+ VEC_safe_push (unsigned, heap, si->scc_stack, n);
}
-
-/* Unify nodes in GRAPH that we have found to be part of a cycle.
- SI is the Strongly Connected Components information structure that tells us
- what components to unify.
- UPDATE_CHANGED should be set to true if the changed sbitmap and changed
- count should be updated to reflect the unification. */
+/* Unify node FROM into node TO, updating the changed count if
+ necessary when UPDATE_CHANGED is true. */
static void
-process_unification_queue (constraint_graph_t graph, struct scc_info *si,
- bool update_changed)
+unify_nodes (constraint_graph_t graph, unsigned int to, unsigned int from,
+ bool update_changed)
{
- size_t i = 0;
- bitmap tmp = BITMAP_ALLOC (update_changed ? &iteration_obstack : NULL);
- bitmap_clear (tmp);
-
- /* We proceed as follows:
-
- For each component in the queue (components are delineated by
- when current_queue_element->node != next_queue_element->node):
- rep = representative node for component
+ 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);
- For each node (tounify) to be unified in the component,
- merge the solution for tounify into tmp bitmap
-
- clear solution for tounify
-
- merge edges from tounify into rep
+ if (update_changed)
+ stats.unified_vars_dynamic++;
+ else
+ stats.unified_vars_static++;
- merge complex constraints from tounify into rep
+ merge_graph_nodes (graph, to, from);
+ merge_node_constraints (graph, to, from);
- update changed count to note that tounify will never change
- again
+ /* Mark TO as changed if FROM was changed. If TO was already marked
+ as changed, decrease the changed count. */
- Merge tmp into solution for rep, marking rep changed if this
- changed rep's solution.
-
- Delete any 0 weighted self-edges we now have for rep. */
- while (i != VEC_length (unsigned, si->unification_queue))
+ if (update_changed && TEST_BIT (changed, from))
{
- unsigned int tounify = VEC_index (unsigned, si->unification_queue, i);
- unsigned int n = get_varinfo (tounify)->node;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Unifying %s to %s\n",
- get_varinfo (tounify)->name,
- get_varinfo (n)->name);
- if (update_changed)
- stats.unified_vars_dynamic++;
+ RESET_BIT (changed, from);
+ if (!TEST_BIT (changed, to))
+ SET_BIT (changed, to);
else
- stats.unified_vars_static++;
- bitmap_ior_into (tmp, get_varinfo (tounify)->solution);
- merge_graph_nodes (graph, n, tounify);
- condense_varmap_nodes (n, tounify);
-
- if (update_changed && TEST_BIT (changed, tounify))
{
- RESET_BIT (changed, tounify);
- if (!TEST_BIT (changed, n))
- SET_BIT (changed, n);
- else
+ gcc_assert (changed_count > 0);
+ changed_count--;
+ }
+ }
+ 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 && !TEST_BIT (changed, to))
{
- gcc_assert (changed_count > 0);
- changed_count--;
+ SET_BIT (changed, to);
+ changed_count++;
}
}
- bitmap_clear (get_varinfo (tounify)->solution);
- ++i;
+ BITMAP_FREE (get_varinfo (from)->solution);
+ BITMAP_FREE (get_varinfo (from)->oldsolution);
- /* If we've either finished processing the entire queue, or
- finished processing all nodes for component n, update the solution for
- n. */
- if (i == VEC_length (unsigned, si->unification_queue)
- || get_varinfo (VEC_index (unsigned, si->unification_queue, i))->node != n)
+ if (stats.iterations > 0)
{
- /* If the solution changes because of the merging, we need to mark
- the variable as changed. */
- if (bitmap_ior_into (get_varinfo (n)->solution, tmp))
- {
- if (update_changed && !TEST_BIT (changed, n))
- {
- SET_BIT (changed, n);
- changed_count++;
- }
- }
- bitmap_clear (tmp);
-
- if (valid_graph_edge (graph, n, n))
- {
- if (graph->zero_weight_succs[n])
- {
- if (graph->zero_weight_preds[n])
- bitmap_clear_bit (graph->zero_weight_preds[n], n);
- bitmap_clear_bit (graph->zero_weight_succs[n], n);
- }
- if (valid_weighted_graph_edge (graph, n, n))
- {
- bitmap weights = *(get_graph_weights (graph, n, n));
- if (!weights || bitmap_empty_p (weights))
- erase_graph_self_edge (graph, n);
- }
- }
+ BITMAP_FREE (get_varinfo (to)->oldsolution);
+ get_varinfo (to)->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
}
}
- BITMAP_FREE (tmp);
+ 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
static struct topo_info *
init_topo_info (void)
{
- size_t size = VEC_length (varinfo_t, varmap);
+ size_t size = graph->size;
struct topo_info *ti = XNEW (struct topo_info);
ti->visited = sbitmap_alloc (size);
sbitmap_zero (ti->visited);
topo_visit (constraint_graph_t graph, struct topo_info *ti,
unsigned int n)
{
- VEC(constraint_edge_t,heap) *succs = graph->succs[n];
- bitmap temp;
bitmap_iterator bi;
- constraint_edge_t c;
- int i;
unsigned int j;
SET_BIT (ti->visited, n);
- if (VEC_length (constraint_edge_t, succs) != 0)
- {
- temp = BITMAP_ALLOC (&iteration_obstack);
- if (graph->zero_weight_succs[n])
- bitmap_ior_into (temp, graph->zero_weight_succs[n]);
- for (i = 0; VEC_iterate (constraint_edge_t, succs, i, c); i++)
- bitmap_set_bit (temp, c->dest);
- }
- else
- temp = graph->zero_weight_succs[n];
- if (temp)
- EXECUTE_IF_SET_IN_BITMAP (temp, 0, j, bi)
+ 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);
-}
-
-/* Return true if variable N + OFFSET is a legal field of N. */
-
-static bool
-type_safe (unsigned int n, unsigned HOST_WIDE_INT *offset)
-{
- varinfo_t ninfo = get_varinfo (n);
-
- /* For things we've globbed to single variables, any offset into the
- variable acts like the entire variable, so that it becomes offset
- 0. */
- if (ninfo->is_special_var
- || ninfo->is_artificial_var
- || ninfo->is_unknown_size_var)
- {
- *offset = 0;
- return true;
- }
- return (get_varinfo (n)->offset + *offset) < get_varinfo (n)->fullsize;
-}
-
-/* Process a constraint C that represents *x = &y. */
-
-static void
-do_da_constraint (constraint_graph_t graph ATTRIBUTE_UNUSED,
- constraint_t c, bitmap delta)
-{
- unsigned int rhs = c->rhs.var;
- unsigned int j;
- bitmap_iterator bi;
-
- /* For each member j of Delta (Sol(x)), add x to Sol(j) */
- EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
- {
- unsigned HOST_WIDE_INT offset = c->lhs.offset;
- if (type_safe (j, &offset) && !(get_varinfo (j)->is_special_var))
- {
- /* *x != NULL && *x != ANYTHING*/
- varinfo_t v;
- unsigned int t;
- bitmap sol;
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (j)->offset + offset;
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
- continue;
- t = v->node;
- sol = get_varinfo (t)->solution;
- if (!bitmap_bit_p (sol, rhs))
- {
- bitmap_set_bit (sol, rhs);
- if (!TEST_BIT (changed, t))
- {
- SET_BIT (changed, t);
- changed_count++;
- }
- }
- }
- else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
- fprintf (dump_file, "Untypesafe usage in do_da_constraint.\n");
-
- }
+ VEC_safe_push (unsigned, heap, ti->topo_order, n);
}
-/* Process a constraint C that represents x = *y, using DELTA as the
- starting solution. */
+/* 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 = get_varinfo (c->lhs.var)->node;
+ 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;
- if (bitmap_bit_p (delta, anything_id))
- {
- flag = !bitmap_bit_p (sol, anything_id);
- if (flag)
- bitmap_set_bit (sol, anything_id);
- goto done;
- }
- /* For each variable j in delta (Sol(y)), add
+ /* 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)
{
- unsigned HOST_WIDE_INT roffset = c->rhs.offset;
- if (type_safe (j, &roffset))
- {
- varinfo_t v;
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (j)->offset + roffset;
- unsigned int t;
+ 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;
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
- continue;
- t = v->node;
+ 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)
+ if (get_varinfo (t)->is_special_var)
flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
- else if (int_add_graph_edge (graph, lhs, t, 0))
+ /* 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;
}
- else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
- fprintf (dump_file, "Untypesafe usage in do_sd_constraint\n");
-
+ while (1);
}
done:
SET_BIT (changed, lhs);
changed_count++;
}
- }
+ }
}
-/* Process a constraint C that represents *x = y. */
+/* Process a constraint C that represents *(x + off) = y using DELTA
+ as the starting solution for x. */
static void
-do_ds_constraint (constraint_graph_t graph, constraint_t c, bitmap delta)
+do_ds_constraint (constraint_t c, bitmap delta)
{
- unsigned int rhs = get_varinfo (c->rhs.var)->node;
- unsigned HOST_WIDE_INT roff = c->rhs.offset;
+ 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;
- if (bitmap_bit_p (sol, anything_id))
- {
- EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
- {
- varinfo_t jvi = get_varinfo (j);
- unsigned int t;
- unsigned int loff = c->lhs.offset;
- unsigned HOST_WIDE_INT fieldoffset = jvi->offset + loff;
- varinfo_t v;
-
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
- continue;
- t = v->node;
-
- if (!bitmap_bit_p (get_varinfo (t)->solution, anything_id))
- {
- bitmap_set_bit (get_varinfo (t)->solution, anything_id);
- if (!TEST_BIT (changed, t))
- {
- SET_BIT (changed, t);
- changed_count++;
- }
- }
- }
- return;
- }
+ /* Our IL does not allow this. */
+ gcc_assert (c->rhs.offset == 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)
+ /* 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 HOST_WIDE_INT loff = c->lhs.offset;
- if (type_safe (j, &loff) && !(get_varinfo(j)->is_special_var))
+ unsigned t = find (storedanything_id);
+ if (add_graph_edge (graph, t, rhs))
{
- varinfo_t v;
- unsigned int t;
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (j)->offset + loff;
+ if (bitmap_ior_into (get_varinfo (t)->solution, sol))
+ {
+ if (!TEST_BIT (changed, t))
+ {
+ SET_BIT (changed, t);
+ changed_count++;
+ }
+ }
+ }
+ return;
+ }
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
- continue;
- t = v->node;
- if (int_add_graph_edge (graph, t, rhs, roff))
+ /* 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)
{
- bitmap tmp = get_varinfo (t)->solution;
- if (set_union_with_increment (tmp, sol, roff))
+ /* If v is a global variable then this is an escape point. */
+ if (v->is_global_var
+ && !escaped_p)
{
- get_varinfo (t)->solution = tmp;
- if (t == rhs)
- sol = get_varinfo (rhs)->solution;
- if (!TEST_BIT (changed, t))
+ t = find (escaped_id);
+ if (add_graph_edge (graph, t, rhs)
+ && bitmap_ior_into (get_varinfo (t)->solution, sol)
+ && !TEST_BIT (changed, t))
{
SET_BIT (changed, t);
changed_count++;
}
+ /* 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)
+ && !TEST_BIT (changed, t))
+ {
+ SET_BIT (changed, t);
+ changed_count++;
}
}
- }
- else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
- fprintf (dump_file, "Untypesafe usage in do_ds_constraint\n");
+
+ /* 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), non-copy
- constraint (IE *x = &y, x = *y, and *x = y). */
-
+/* 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->rhs.type == ADDRESSOF)
{
- /* *x = &y */
- do_da_constraint (graph, c, delta);
+ gcc_unreachable();
}
else
{
/* *x = y */
- do_ds_constraint (graph, c, delta);
+ do_ds_constraint (c, delta);
}
}
- else
+ 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;
+ if (!TEST_BIT (changed, c->lhs.var))
+ {
+ SET_BIT (changed, c->lhs.var);
+ changed_count++;
+ }
+ }
+ }
}
/* Initialize and return a new SCC info structure. */
static struct scc_info *
-init_scc_info (void)
+init_scc_info (size_t size)
{
struct scc_info *si = XNEW (struct scc_info);
- size_t size = VEC_length (varinfo_t, varmap);
+ size_t i;
si->current_index = 0;
si->visited = sbitmap_alloc (size);
sbitmap_zero (si->visited);
- si->in_component = sbitmap_alloc (size);
- sbitmap_ones (si->in_component);
- si->visited_index = XCNEWVEC (unsigned int, size + 1);
+ 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);
- si->unification_queue = VEC_alloc (unsigned, heap, 1);
return si;
}
static void
free_scc_info (struct scc_info *si)
-{
+{
sbitmap_free (si->visited);
- sbitmap_free (si->in_component);
- free (si->visited_index);
+ sbitmap_free (si->deleted);
+ free (si->node_mapping);
+ free (si->dfs);
VEC_free (unsigned, heap, si->scc_stack);
- VEC_free (unsigned, heap, si->unification_queue);
- free(si);
+ free (si);
}
-/* Find cycles in GRAPH that occur, using strongly connected components, and
- collapse the cycles into a single representative node. if UPDATE_CHANGED
- is true, then update the changed sbitmap to note those nodes whose
- solutions have changed as a result of collapsing. */
+/* 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_and_collapse_graph_cycles (constraint_graph_t graph, bool update_changed)
+find_indirect_cycles (constraint_graph_t graph)
{
unsigned int i;
- unsigned int size = VEC_length (varinfo_t, varmap);
- struct scc_info *si = init_scc_info ();
+ unsigned int size = graph->size;
+ struct scc_info *si = init_scc_info (size);
- for (i = 0; i != size; ++i)
- if (!TEST_BIT (si->visited, i) && get_varinfo (i)->node == i)
+ for (i = 0; i < MIN (LAST_REF_NODE, size); i ++ )
+ if (!TEST_BIT (si->visited, i) && find (i) == i)
scc_visit (graph, si, i);
-
- process_unification_queue (graph, si, update_changed);
+
free_scc_info (si);
}
/* Compute a topological ordering for GRAPH, and store the result in the
topo_info structure TI. */
-static void
+static void
compute_topo_order (constraint_graph_t graph,
struct topo_info *ti)
{
unsigned int i;
- unsigned int size = VEC_length (varinfo_t, varmap);
-
+ unsigned int size = graph->size;
+
for (i = 0; i != size; ++i)
- if (!TEST_BIT (ti->visited, i) && get_varinfo (i)->node == i)
+ if (!TEST_BIT (ti->visited, i) && find (i) == i)
topo_visit (graph, ti, i);
}
-/* Return true if bitmap B is empty, or a bitmap other than bit 0 is set. */
+/* Structure used to for hash value numbering of pointer equivalence
+ classes. */
-static bool
-bitmap_other_than_zero_bit_set (bitmap b)
+typedef struct equiv_class_label
{
- unsigned int i;
- bitmap_iterator bi;
+ hashval_t hashcode;
+ unsigned int equivalence_class;
+ bitmap labels;
+} *equiv_class_label_t;
+typedef const struct equiv_class_label *const_equiv_class_label_t;
- if (bitmap_empty_p (b))
- return false;
- EXECUTE_IF_SET_IN_BITMAP (b, 1, i, bi)
- return true;
- return false;
-}
+/* A hashtable for mapping a bitmap of labels->pointer equivalence
+ classes. */
+static htab_t pointer_equiv_class_table;
-/* Perform offline variable substitution.
-
- This is a linear 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.
+/* A hashtable for mapping a bitmap of labels->location equivalence
+ classes. */
+static htab_t location_equiv_class_table;
- The technique is described in "Off-line variable substitution for
- scaling points-to analysis" by Atanas Rountev and Satish Chandra,
- in "ACM SIGPLAN Notices" volume 35, number 5, pages 47-56. */
+/* Hash function for a equiv_class_label_t */
-static void
-perform_var_substitution (constraint_graph_t graph)
+static hashval_t
+equiv_class_label_hash (const void *p)
{
- struct topo_info *ti = init_topo_info ();
-
- bitmap_obstack_initialize (&iteration_obstack);
- /* Compute the topological ordering of the graph, then visit each
- node in topological order. */
- compute_topo_order (graph, ti);
-
- while (VEC_length (unsigned, ti->topo_order) != 0)
- {
- unsigned int i = VEC_pop (unsigned, ti->topo_order);
- unsigned int pred;
- varinfo_t vi = get_varinfo (i);
- bool okay_to_elim = false;
- unsigned int root = VEC_length (varinfo_t, varmap);
- VEC(constraint_edge_t,heap) *predvec = graph->preds[i];
- constraint_edge_t ce = NULL;
- bitmap tmp;
- unsigned int k;
- bitmap_iterator bi;
+ const_equiv_class_label_t const ecl = (const_equiv_class_label_t) p;
+ return ecl->hashcode;
+}
- /* We can't eliminate things whose address is taken, or which is
- the target of a dereference. */
- if (vi->address_taken || vi->indirect_target)
- continue;
+/* Equality function for two equiv_class_label_t's. */
- /* See if all predecessors of I are ripe for elimination */
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->zero_weight_preds[i], 0, k, bi)
- {
- unsigned int w;
- w = get_varinfo (k)->node;
+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));
+}
- /* We can't eliminate the node if one of the predecessors is
- part of a different strongly connected component. */
- if (!okay_to_elim)
- {
- root = w;
- okay_to_elim = true;
- }
- else if (w != root)
- {
- okay_to_elim = false;
- break;
- }
+/* Lookup a equivalence class in TABLE by the bitmap of LABELS it
+ contains. */
- /* Theorem 4 in Rountev and Chandra: If i is a direct node,
- then Solution(i) is a subset of Solution (w), where w is a
- predecessor in the graph.
- Corollary: If all predecessors of i have the same
- points-to set, then i has that same points-to set as
- those predecessors. */
- tmp = BITMAP_ALLOC (NULL);
- bitmap_and_compl (tmp, get_varinfo (i)->solution,
- get_varinfo (w)->solution);
- if (!bitmap_empty_p (tmp))
- {
- okay_to_elim = false;
- BITMAP_FREE (tmp);
- break;
- }
- BITMAP_FREE (tmp);
- }
+static unsigned int
+equiv_class_lookup (htab_t table, bitmap labels)
+{
+ void **slot;
+ struct equiv_class_label ecl;
- if (okay_to_elim)
- for (pred = 0;
- VEC_iterate (constraint_edge_t, predvec, pred, ce);
- pred++)
- {
- bitmap weight;
- unsigned int w;
- weight = *(get_graph_weights (graph, i, ce->dest));
+ ecl.labels = labels;
+ ecl.hashcode = bitmap_hash (labels);
- /* We can't eliminate variables that have nonzero weighted
- edges between them. */
- if (weight && bitmap_other_than_zero_bit_set (weight))
- {
- okay_to_elim = false;
- break;
- }
- w = get_varinfo (ce->dest)->node;
+ 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;
+}
- /* We can't eliminate the node if one of the predecessors is
- part of a different strongly connected component. */
- if (!okay_to_elim)
- {
- root = w;
- okay_to_elim = true;
- }
- else if (w != root)
- {
- okay_to_elim = false;
- break;
- }
- /* Theorem 4 in Rountev and Chandra: If i is a direct node,
- then Solution(i) is a subset of Solution (w), where w is a
- predecessor in the graph.
- Corollary: If all predecessors of i have the same
- points-to set, then i has that same points-to set as
- those predecessors. */
- tmp = BITMAP_ALLOC (NULL);
- bitmap_and_compl (tmp, get_varinfo (i)->solution,
- get_varinfo (w)->solution);
- if (!bitmap_empty_p (tmp))
- {
- okay_to_elim = false;
- BITMAP_FREE (tmp);
- break;
- }
- BITMAP_FREE (tmp);
- }
+/* Add an equivalence class named EQUIVALENCE_CLASS with labels LABELS
+ to TABLE. */
- /* See if the root is different than the original node.
- If so, we've found an equivalence. */
- if (root != get_varinfo (i)->node && okay_to_elim)
- {
- /* Found an equivalence */
- get_varinfo (i)->node = root;
- collapse_nodes (graph, root, i);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Collapsing %s into %s\n",
- get_varinfo (i)->name,
- get_varinfo (root)->name);
- stats.collapsed_vars++;
- }
- }
+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);
- bitmap_obstack_release (&iteration_obstack);
- free_topo_info (ti);
+ 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;
}
-/* 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. */
+/* 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
-solve_graph (constraint_graph_t graph)
+condense_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
{
- unsigned int size = VEC_length (varinfo_t, varmap);
unsigned int i;
+ bitmap_iterator bi;
+ unsigned int my_dfs;
- changed_count = size;
- changed = sbitmap_alloc (size);
- sbitmap_ones (changed);
-
- /* The already collapsed/unreachable nodes will never change, so we
- need to account for them in changed_count. */
- for (i = 0; i < size; i++)
- if (get_varinfo (i)->node != i)
- changed_count--;
-
- while (changed_count > 0)
+ 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 i;
- struct topo_info *ti = init_topo_info ();
- stats.iterations++;
+ unsigned int w = si->node_mapping[i];
- bitmap_obstack_initialize (&iteration_obstack);
-
- if (edge_added)
- {
- /* We already did cycle elimination once, when we did
- variable substitution, so we don't need it again for the
- first iteration. */
- if (stats.iterations > 1)
- find_and_collapse_graph_cycles (graph, true);
+ if (TEST_BIT (si->deleted, w))
+ continue;
- edge_added = false;
- }
+ 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);
- compute_topo_order (graph, ti);
+ if (si->dfs[t] < si->dfs[nnode])
+ si->dfs[n] = si->dfs[t];
+ }
+ }
- while (VEC_length (unsigned, ti->topo_order) != 0)
- {
- i = VEC_pop (unsigned, ti->topo_order);
- gcc_assert (get_varinfo (i)->node == i);
+ /* 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 the node has changed, we need to process the
- complex constraints and outgoing edges again. */
- if (TEST_BIT (changed, i))
- {
- unsigned int j;
- constraint_t c;
- constraint_edge_t e = NULL;
- bitmap solution;
- bitmap_iterator bi;
- VEC(constraint_t,heap) *complex = get_varinfo (i)->complex;
- VEC(constraint_edge_t,heap) *succs;
+ if (TEST_BIT (si->deleted, w))
+ continue;
- RESET_BIT (changed, i);
- changed_count--;
+ 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);
- /* Process the complex constraints */
- solution = get_varinfo (i)->solution;
- for (j = 0; VEC_iterate (constraint_t, complex, j, c); j++)
- do_complex_constraint (graph, c, solution);
+ if (si->dfs[t] < si->dfs[nnode])
+ si->dfs[n] = si->dfs[t];
+ }
+ }
- /* Propagate solution to all successors. */
- succs = graph->succs[i];
-
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->zero_weight_succs[i], 0, j, bi)
- {
- bitmap tmp = get_varinfo (j)->solution;
- bool flag = false;
-
- flag = set_union_with_increment (tmp, solution, 0);
-
- if (flag)
- {
- get_varinfo (j)->solution = tmp;
- if (!TEST_BIT (changed, j))
- {
- SET_BIT (changed, j);
- changed_count++;
- }
- }
- }
- for (j = 0; VEC_iterate (constraint_edge_t, succs, j, e); j++)
- {
- bitmap tmp = get_varinfo (e->dest)->solution;
- bool flag = false;
- unsigned int k;
- bitmap weights = e->weights;
- bitmap_iterator bi;
+ /* 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;
- gcc_assert (weights && !bitmap_empty_p (weights));
- EXECUTE_IF_SET_IN_BITMAP (weights, 0, k, bi)
- flag |= set_union_with_increment (tmp, solution, k);
+ if (!TEST_BIT (graph->direct_nodes, w))
+ RESET_BIT (graph->direct_nodes, n);
- if (flag)
- {
- get_varinfo (e->dest)->solution = tmp;
- if (!TEST_BIT (changed, e->dest))
- {
- SET_BIT (changed, e->dest);
- changed_count++;
- }
- }
- }
+ /* 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]);
}
}
- free_topo_info (ti);
- bitmap_obstack_release (&iteration_obstack);
+ SET_BIT (si->deleted, n);
}
-
- sbitmap_free (changed);
+ else
+ VEC_safe_push (unsigned, heap, si->scc_stack, n);
}
+/* Label pointer equivalences. */
-/* CONSTRAINT AND VARIABLE GENERATION FUNCTIONS */
-
-/* Map from trees to variable ids. */
-static htab_t id_for_tree;
-
-typedef struct tree_id
+static void
+label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
{
- tree t;
- unsigned int id;
-} *tree_id_t;
+ unsigned int i;
+ bitmap_iterator bi;
+ SET_BIT (si->visited, n);
-/* Hash a tree id structure. */
+ if (!graph->points_to[n])
+ graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack);
-static hashval_t
-tree_id_hash (const void *p)
-{
- const tree_id_t ta = (tree_id_t) p;
- return htab_hash_pointer (ta->t);
-}
+ /* 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);
-/* Return true if the tree in P1 and the tree in P2 are the same. */
+ /* Skip unused edges */
+ if (w == n || graph->pointer_label[w] == 0)
+ continue;
-static int
-tree_id_eq (const void *p1, const void *p2)
-{
- const tree_id_t ta1 = (tree_id_t) p1;
- const tree_id_t ta2 = (tree_id_t) p2;
- return ta1->t == ta2->t;
+ 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;
+ }
}
-/* Insert ID as the variable id for tree T in the hashtable. */
+/* Perform offline variable substitution, discovering equivalence
+ classes, and eliminating non-pointer variables. */
-static void
-insert_id_for_tree (tree t, int id)
+static struct scc_info *
+perform_var_substitution (constraint_graph_t graph)
{
- void **slot;
- struct tree_id finder;
- tree_id_t new_pair;
-
- finder.t = t;
- slot = htab_find_slot (id_for_tree, &finder, INSERT);
- gcc_assert (*slot == NULL);
- new_pair = XNEW (struct tree_id);
- new_pair->t = t;
- new_pair->id = id;
- *slot = (void *)new_pair;
-}
+ unsigned int i;
+ unsigned int size = graph->size;
+ struct scc_info *si = init_scc_info (size);
-/* Find the variable id for tree T in ID_FOR_TREE. If T does not
- exist in the hash table, return false, otherwise, return true and
- set *ID to the id we found. */
+ 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]);
-static bool
-lookup_id_for_tree (tree t, unsigned int *id)
-{
- tree_id_t pair;
- struct tree_id finder;
+ 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]);
- finder.t = t;
- pair = htab_find (id_for_tree, &finder);
- if (pair == NULL)
- return false;
- *id = pair->id;
- return true;
-}
+ /* Calculate location equivalence labels. */
+ for (i = 0; i < FIRST_REF_NODE; i++)
+ {
+ bitmap pointed_by;
+ bitmap_iterator bi;
+ unsigned int j;
+ unsigned int label;
-/* Return a printable name for DECL */
+ if (!graph->pointed_by[i])
+ continue;
+ pointed_by = BITMAP_ALLOC (&iteration_obstack);
-static const char *
-alias_get_name (tree decl)
-{
- const char *res = get_name (decl);
- char *temp;
- int num_printed = 0;
+ /* 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 (res != NULL)
- return res;
+ }
- res = "NULL";
- if (!dump_file)
- return res;
+ 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]]);
+ }
- if (TREE_CODE (decl) == SSA_NAME)
+ /* Quickly eliminate our non-pointer variables. */
+
+ for (i = 0; i < FIRST_REF_NODE; i++)
{
- num_printed = asprintf (&temp, "%s_%u",
- alias_get_name (SSA_NAME_VAR (decl)),
- SSA_NAME_VERSION (decl));
- }
+ 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 (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
+ {
+ 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 (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
+ {
+ 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);
+ }
+ 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);
+ }
+ 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_count = 0;
+ changed = sbitmap_alloc (size);
+ sbitmap_zero (changed);
+
+ /* 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))
+ {
+ SET_BIT (changed, i);
+ changed_count++;
+ }
+ }
+
+ /* Allocate a bitmap to be used to store the changed bits. */
+ pts = BITMAP_ALLOC (&pta_obstack);
+
+ while (changed_count > 0)
+ {
+ 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 (TEST_BIT (changed, i))
+ {
+ unsigned int j;
+ constraint_t c;
+ bitmap solution;
+ VEC(constraint_t,heap) *complex = graph->complex[i];
+ bool solution_empty;
+
+ RESET_BIT (changed, i);
+ changed_count--;
+
+ /* Compute the changed set of solution bits. */
+ bitmap_and_compl (pts, get_varinfo (i)->solution,
+ get_varinfo (i)->oldsolution);
+
+ if (bitmap_empty_p (pts))
+ continue;
+
+ bitmap_ior_into (get_varinfo (i)->oldsolution, pts);
+
+ solution = get_varinfo (i)->solution;
+ solution_empty = bitmap_empty_p (solution);
+
+ /* Process the complex constraints */
+ for (j = 0; VEC_iterate (constraint_t, complex, j, c); j++)
+ {
+ /* 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;
+ if (!TEST_BIT (changed, to))
+ {
+ SET_BIT (changed, to);
+ changed_count++;
+ }
+ }
+ }
+ }
+ }
+ }
+ free_topo_info (ti);
+ bitmap_obstack_release (&iteration_obstack);
+ }
+
+ BITMAP_FREE (pts);
+ sbitmap_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 = get_name (decl);
+ char *temp;
+ int num_printed = 0;
+
+ 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));
return res;
}
-/* Find the variable id for tree T in the hashtable.
- If T doesn't exist in the hash table, create an entry for it. */
+/* 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 unsigned int
-get_id_for_tree (tree t)
+static varinfo_t
+get_vi_for_tree (tree t)
{
- tree_id_t pair;
- struct tree_id finder;
+ void **slot = pointer_map_contains (vi_for_tree, t);
+ if (slot == NULL)
+ return get_varinfo (create_variable_info_for (t, alias_get_name (t)));
- finder.t = t;
- pair = htab_find (id_for_tree, &finder);
- if (pair == NULL)
- return create_variable_info_for (t, alias_get_name (t));
-
- return pair->id;
+ return (varinfo_t) *slot;
}
-/* Get a constraint expression from an SSA_VAR_P node. */
+/* Get a scalar constraint expression for a new temporary variable. */
static struct constraint_expr
-get_constraint_exp_from_ssa_var (tree t)
+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
- && default_def (SSA_NAME_VAR (t)) == t)
- return get_constraint_exp_from_ssa_var (SSA_NAME_VAR (t));
+ if (TREE_CODE (t) == SSA_NAME
+ && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL
+ && SSA_NAME_IS_DEFAULT_DEF (t))
+ {
+ get_constraint_for_ssa_var (SSA_NAME_VAR (t), results, address_p);
+ return;
+ }
+ vi = get_vi_for_tree (t);
+ cexpr.var = vi->id;
cexpr.type = SCALAR;
-
- cexpr.var = get_id_for_tree (t);
+ 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;
}
-
- cexpr.offset = 0;
- return cexpr;
+
+ /* 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 a completed constraint T, and add it to the constraint
- list. */
+/* 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));
- /* ANYTHING == ANYTHING is pointless. */
- if (lhs.var == anything_id && rhs.var == anything_id)
+ /* 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;
- /* If we have &ANYTHING = something, convert to SOMETHING = &ANYTHING) */
- else if (lhs.var == anything_id && lhs.type == ADDRESSOF)
- {
- rhs = t->lhs;
- t->lhs = t->rhs;
- t->rhs = rhs;
- process_constraint (t);
- }
/* This can happen in our IR with things like n->a = *p */
- else if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
+ if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
{
/* Split into tmp = *rhs, *lhs = tmp */
- tree rhsdecl = get_varinfo (rhs.var)->decl;
- tree pointertype = TREE_TYPE (rhsdecl);
- tree pointedtotype = TREE_TYPE (pointertype);
- tree tmpvar = create_tmp_var_raw (pointedtotype, "doubledereftmp");
- struct constraint_expr tmplhs = get_constraint_exp_from_ssa_var (tmpvar);
-
- /* If this is an aggregate of known size, we should have passed
- this off to do_structure_copy, and it should have broken it
- up. */
- gcc_assert (!AGGREGATE_TYPE_P (pointedtotype)
- || get_varinfo (rhs.var)->is_unknown_size_var);
-
+ 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)
+ else if (rhs.type == ADDRESSOF && lhs.type == DEREF)
{
- varinfo_t vi;
- gcc_assert (rhs.offset == 0);
-
- for (vi = get_varinfo (rhs.var); vi != NULL; vi = vi->next)
- vi->address_taken = true;
-
- VEC_safe_push (constraint_t, heap, constraints, t);
+ /* 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
{
- if (lhs.type != DEREF && rhs.type == DEREF)
- get_varinfo (lhs.var)->indirect_target = true;
+ gcc_assert (rhs.type != ADDRESSOF || rhs.offset == 0);
VEC_safe_push (constraint_t, heap, constraints, t);
}
}
+/* Return true if T is a type that could contain pointers. */
+
+static bool
+type_could_have_pointers (tree type)
+{
+ if (POINTER_TYPE_P (type))
+ return true;
+
+ if (TREE_CODE (type) == ARRAY_TYPE)
+ return type_could_have_pointers (TREE_TYPE (type));
+
+ return AGGREGATE_TYPE_P (type);
+}
+
+/* Return true if T is a variable of a type that could contain
+ pointers. */
+
+static bool
+could_have_pointers (tree t)
+{
+ return type_could_have_pointers (TREE_TYPE (t));
+}
/* Return the position, in bits, of FIELD_DECL from the beginning of its
structure. */
-static unsigned HOST_WIDE_INT
+static HOST_WIDE_INT
bitpos_of_field (const tree fdecl)
{
- if (TREE_CODE (DECL_FIELD_OFFSET (fdecl)) != INTEGER_CST
- || TREE_CODE (DECL_FIELD_BIT_OFFSET (fdecl)) != INTEGER_CST)
+ if (!host_integerp (DECL_FIELD_OFFSET (fdecl), 0)
+ || !host_integerp (DECL_FIELD_BIT_OFFSET (fdecl), 0))
return -1;
-
- return (tree_low_cst (DECL_FIELD_OFFSET (fdecl), 1) * 8)
- + tree_low_cst (DECL_FIELD_BIT_OFFSET (fdecl), 1);
+
+ return (TREE_INT_CST_LOW (DECL_FIELD_OFFSET (fdecl)) * 8
+ + TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fdecl)));
}
-/* Return true if an access to [ACCESSPOS, ACCESSSIZE]
- overlaps with a field at [FIELDPOS, FIELDSIZE] */
+/* 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 rhsunitoffset, 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 (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
+ || !host_integerp (offset, 0))
+ rhsoffset = UNKNOWN_OFFSET;
+ else
+ {
+ /* Make sure the bit-offset also fits. */
+ rhsunitoffset = TREE_INT_CST_LOW (offset);
+ rhsoffset = rhsunitoffset * BITS_PER_UNIT;
+ if (rhsunitoffset != rhsoffset / BITS_PER_UNIT)
+ rhsoffset = UNKNOWN_OFFSET;
+ }
+
+ get_constraint_for (ptr, results);
+ if (rhsoffset == 0)
+ return;
-static bool
-offset_overlaps_with_access (const unsigned HOST_WIDE_INT fieldpos,
- const unsigned HOST_WIDE_INT fieldsize,
- const unsigned HOST_WIDE_INT accesspos,
- const unsigned HOST_WIDE_INT accesssize)
-{
- if (fieldpos == accesspos && fieldsize == accesssize)
- return true;
- if (accesspos >= fieldpos && accesspos < (fieldpos + fieldsize))
- return true;
- if (accesspos < fieldpos && (accesspos + accesssize > fieldpos))
- return true;
-
- return false;
+ /* 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 for it. */
+
+/* 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. */
static void
-get_constraint_for_component_ref (tree t, VEC(ce_s, heap) **results)
+get_constraint_for_component_ref (tree t, VEC(ce_s, heap) **results,
+ bool address_p)
{
tree orig_t = t;
HOST_WIDE_INT bitsize = -1;
HOST_WIDE_INT bitpos;
tree forzero;
struct constraint_expr *result;
- unsigned int beforelength = VEC_length (ce_s, *results);
/* Some people like to do cute things like take the address of
&0->a.b */
forzero = t;
- while (!SSA_VAR_P (forzero) && !CONSTANT_CLASS_P (forzero))
+ while (handled_component_p (forzero)
+ || INDIRECT_REF_P (forzero))
forzero = TREE_OPERAND (forzero, 0);
- if (CONSTANT_CLASS_P (forzero) && integer_zerop (forzero))
+ 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;
}
-
+
t = get_ref_base_and_extent (t, &bitpos, &bitsize, &bitmaxsize);
- get_constraint_for (t, results);
- result = VEC_last (ce_s, *results);
- result->offset = bitpos;
- gcc_assert (beforelength + 1 == VEC_length (ce_s, *results));
+ /* 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);
+ gcc_assert (VEC_length (ce_s, *results) == 1);
+ result = VEC_last (ce_s, *results);
- /* This can also happen due to weird offsetof type macros. */
- if (TREE_CODE (t) != ADDR_EXPR && result->type == ADDRESSOF)
- result->type = SCALAR;
-
- if (result->type == SCALAR)
+ 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 (result->offset < get_varinfo (result->var)->fullsize
+
+ 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. */
+ walk to find it. */
+ struct constraint_expr cexpr = *result;
varinfo_t curr;
- for (curr = get_varinfo (result->var); curr; curr = curr->next)
+ VEC_pop (ce_s, *results);
+ cexpr.offset = 0;
+ for (curr = get_varinfo (cexpr.var); curr; curr = curr->next)
{
- if (offset_overlaps_with_access (curr->offset, curr->size,
- result->offset, bitmaxsize))
+ if (ranges_overlap_p (curr->offset, curr->size,
+ bitpos, bitmaxsize))
{
- result->var = curr->id;
- break;
+ cexpr.var = curr->id;
+ VEC_safe_push (ce_s, heap, *results, &cexpr);
+ if (address_p)
+ break;
}
}
- /* 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. */
- gcc_assert (curr || ref_contains_array_ref (orig_t));
+ /* 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
+ /* 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. */
+ gcc_assert (VEC_length (ce_s, *results) >= 1
+ || ref_contains_array_ref (orig_t));
}
else if (bitmaxsize == 0)
{
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;
+ 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 ();
}
{
struct constraint_expr *c;
unsigned int i = 0;
+
for (i = 0; VEC_iterate (ce_s, *constraints, i, c); i++)
{
if (c->type == SCALAR)
c->type = SCALAR;
else if (c->type == DEREF)
{
- tree tmpvar = create_tmp_var_raw (ptr_type_node, "dereftmp");
- struct constraint_expr tmplhs = get_constraint_exp_from_ssa_var (tmpvar);
+ struct constraint_expr tmplhs;
+ tmplhs = new_scalar_tmp_constraint_exp ("dereftmp");
process_constraint (new_constraint (tmplhs, *c));
c->var = tmplhs.var;
}
}
}
+static void get_constraint_for_1 (tree, VEC (ce_s, heap) **, bool);
+
+/* 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);
+
+ for (i = 0; VEC_iterate (ce_s, *results, i, c); i++)
+ {
+ 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 (tree t, VEC (ce_s, heap) **results)
+get_constraint_for_1 (tree t, VEC (ce_s, heap) **results, bool address_p)
{
struct constraint_expr temp;
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. */
- if (TREE_CODE (t) == INTEGER_CST
- && !POINTER_TYPE_P (TREE_TYPE (t)))
+ 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 (flag_delete_null_pointer_checks
+ && ((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)))
{
- temp.var = integer_id;
- temp.type = SCALAR;
+ temp.var = nothing_id;
+ temp.type = ADDRESSOF;
temp.offset = 0;
VEC_safe_push (ce_s, heap, *results, &temp);
return;
}
- else if (TREE_CODE (t) == INTEGER_CST
- && integer_zerop (t))
+
+ /* String constants are read-only. */
+ if (TREE_CODE (t) == STRING_CST)
{
- temp.var = nothing_id;
- temp.type = ADDRESSOF;
+ temp.var = readonly_id;
+ temp.type = SCALAR;
temp.offset = 0;
VEC_safe_push (ce_s, heap, *results, &temp);
return;
switch (TREE_CODE (t))
{
case ADDR_EXPR:
- {
- struct constraint_expr *c;
- unsigned int i;
- tree exp = TREE_OPERAND (t, 0);
- tree pttype = TREE_TYPE (TREE_TYPE (t));
-
- get_constraint_for (exp, results);
- /* Make sure we capture constraints to all elements
- of an array. */
- if ((handled_component_p (exp)
- && ref_contains_array_ref (exp))
- || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
- {
- struct constraint_expr *origrhs;
- varinfo_t origvar;
- struct constraint_expr tmp;
-
- gcc_assert (VEC_length (ce_s, *results) == 1);
- origrhs = VEC_last (ce_s, *results);
- tmp = *origrhs;
- VEC_pop (ce_s, *results);
- origvar = get_varinfo (origrhs->var);
- for (; origvar; origvar = origvar->next)
- {
- tmp.var = origvar->id;
- VEC_safe_push (ce_s, heap, *results, &tmp);
- }
- }
- else if (VEC_length (ce_s, *results) == 1
- && (AGGREGATE_TYPE_P (pttype)
- || TREE_CODE (pttype) == COMPLEX_TYPE))
- {
- struct constraint_expr *origrhs;
- varinfo_t origvar;
- struct constraint_expr tmp;
-
- gcc_assert (VEC_length (ce_s, *results) == 1);
- origrhs = VEC_last (ce_s, *results);
- tmp = *origrhs;
- VEC_pop (ce_s, *results);
- origvar = get_varinfo (origrhs->var);
- for (; origvar; origvar = origvar->next)
- {
- tmp.var = origvar->id;
- VEC_safe_push (ce_s, heap, *results, &tmp);
- }
- }
-
- for (i = 0; VEC_iterate (ce_s, *results, i, c); i++)
- {
- if (c->type == DEREF)
- c->type = SCALAR;
- else
- c->type = ADDRESSOF;
- }
- return;
- }
- break;
- case CALL_EXPR:
-
- /* XXX: In interprocedural mode, if we didn't have the
- body, we would need to do *each pointer argument =
- &ANYTHING added. */
- if (call_expr_flags (t) & (ECF_MALLOC | ECF_MAY_BE_ALLOCA))
- {
- varinfo_t vi;
- tree heapvar = heapvar_lookup (t);
-
- if (heapvar == NULL)
- {
- heapvar = create_tmp_var_raw (ptr_type_node, "HEAP");
- DECL_EXTERNAL (heapvar) = 1;
- if (referenced_vars)
- add_referenced_var (heapvar);
- heapvar_insert (t, heapvar);
- }
-
- temp.var = create_variable_info_for (heapvar,
- alias_get_name (heapvar));
-
- vi = get_varinfo (temp.var);
- vi->is_artificial_var = 1;
- vi->is_heap_var = 1;
- temp.type = ADDRESSOF;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
- return;
- }
- /* FALLTHRU */
- default:
- {
- temp.type = ADDRESSOF;
- temp.var = anything_id;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
- return;
- }
+ get_constraint_for_address_of (TREE_OPERAND (t, 0), results);
+ return;
+ default:;
}
+ break;
}
case tcc_reference:
{
{
case INDIRECT_REF:
{
- get_constraint_for (TREE_OPERAND (t, 0), results);
+ get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p);
do_deref (results);
return;
}
case ARRAY_REF:
case ARRAY_RANGE_REF:
case COMPONENT_REF:
- get_constraint_for_component_ref (t, results);
+ get_constraint_for_component_ref (t, results, address_p);
return;
- default:
- {
- temp.type = ADDRESSOF;
- temp.var = anything_id;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
- return;
- }
- }
- }
- case tcc_unary:
- {
- switch (TREE_CODE (t))
- {
- case NOP_EXPR:
- case CONVERT_EXPR:
- case NON_LVALUE_EXPR:
- {
- tree op = TREE_OPERAND (t, 0);
-
- /* Cast from non-pointer to pointers are bad news for us.
- Anything else, we see through */
- if (!(POINTER_TYPE_P (TREE_TYPE (t))
- && ! POINTER_TYPE_P (TREE_TYPE (op))))
- {
- get_constraint_for (op, results);
- return;
- }
-
- /* FALLTHRU */
- }
- default:
- {
- temp.type = ADDRESSOF;
- temp.var = anything_id;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
- return;
- }
+ case VIEW_CONVERT_EXPR:
+ get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p);
+ return;
+ /* We are missing handling for TARGET_MEM_REF here. */
+ default:;
}
+ break;
}
case tcc_exceptional:
{
switch (TREE_CODE (t))
{
- case PHI_NODE:
- {
- get_constraint_for (PHI_RESULT (t), results);
- return;
- }
- break;
case SSA_NAME:
{
- struct constraint_expr temp;
- temp = get_constraint_exp_from_ssa_var (t);
- VEC_safe_push (ce_s, heap, *results, &temp);
+ get_constraint_for_ssa_var (t, results, address_p);
return;
}
- break;
- default:
+ case CONSTRUCTOR:
{
- temp.type = ADDRESSOF;
- temp.var = anything_id;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
+ 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);
+ for (j = 0; VEC_iterate (ce_s, tmp, j, rhsp); ++j)
+ 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:
{
- struct constraint_expr temp;
- temp = get_constraint_exp_from_ssa_var (t);
- VEC_safe_push (ce_s, heap, *results, &temp);
- return;
- }
- default:
- {
- temp.type = ADDRESSOF;
- temp.var = anything_id;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
+ get_constraint_for_ssa_var (t, results, address_p);
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);
+}
+
+
+/* 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 (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
+ for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); ++j)
+ process_constraint (new_constraint (*lhsp, *rhsp));
+ }
+ else
+ {
+ struct constraint_expr tmp;
+ tmp = new_scalar_tmp_constraint_exp ("allalltmp");
+ for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
+ process_constraint (new_constraint (tmp, *rhsp));
+ for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
+ 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 (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
+ && ranges_overlap_p (lhsv->offset + rhsoffset, lhsv->size,
+ rhsv->offset + lhsoffset, rhsv->size))
+ process_constraint (new_constraint (*lhsp, *rhsp));
+ if (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 a constraint ID = OP. */
+
+static void
+make_constraint_to (unsigned id, tree op)
+{
+ VEC(ce_s, heap) *rhsc = NULL;
+ struct constraint_expr *c;
+ struct constraint_expr includes;
+ unsigned int j;
+
+ includes.var = id;
+ includes.offset = 0;
+ includes.type = SCALAR;
+
+ get_constraint_for (op, &rhsc);
+ for (j = 0; VEC_iterate (ce_s, rhsc, j, c); j++)
+ process_constraint (new_constraint (includes, *c));
+ 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));
}
+/* Create a new artificial heap variable with NAME and make a
+ constraint from it to LHS. Return the created variable. */
+
+static varinfo_t
+make_constraint_from_heapvar (varinfo_t lhs, const char *name)
+{
+ varinfo_t vi;
+ tree heapvar = heapvar_lookup (lhs->decl, lhs->offset);
+
+ if (heapvar == NULL_TREE)
+ {
+ var_ann_t ann;
+ heapvar = create_tmp_var_raw (ptr_type_node, name);
+ DECL_EXTERNAL (heapvar) = 1;
+
+ heapvar_insert (lhs->decl, lhs->offset, heapvar);
+
+ ann = get_var_ann (heapvar);
+ ann->is_heapvar = 1;
+ }
+
+ /* For global vars we need to add a heapvar to the list of referenced
+ vars of a different function than it was created for originally. */
+ if (cfun && gimple_referenced_vars (cfun))
+ add_referenced_var (heapvar);
+
+ 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);
+
+ make_constraint_from (lhs, vi->id);
-/* Handle the structure copy case where we have a simple structure copy
- between LHS and RHS that is of SIZE (in bits)
-
- For each field of the lhs variable (lhsfield)
- For each field of the rhs variable at lhsfield.offset (rhsfield)
- add the constraint lhsfield = rhsfield
+ return vi;
+}
- If we fail due to some kind of type unsafety or other thing we
- can't handle, return false. We expect the caller to collapse the
- variable in that case. */
+/* 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 bool
-do_simple_structure_copy (const struct constraint_expr lhs,
- const struct constraint_expr rhs,
- const unsigned HOST_WIDE_INT size)
-{
- varinfo_t p = get_varinfo (lhs.var);
- unsigned HOST_WIDE_INT pstart, last;
- pstart = p->offset;
- last = p->offset + size;
- for (; p && p->offset < last; p = p->next)
- {
- varinfo_t q;
- struct constraint_expr templhs = lhs;
- struct constraint_expr temprhs = rhs;
- unsigned HOST_WIDE_INT fieldoffset;
-
- templhs.var = p->id;
- q = get_varinfo (temprhs.var);
- fieldoffset = p->offset - pstart;
- q = first_vi_for_offset (q, q->offset + fieldoffset);
- if (!q)
- return false;
- temprhs.var = q->id;
- process_constraint (new_constraint (templhs, temprhs));
- }
- return true;
+static void
+make_constraint_from_restrict (varinfo_t lhs, const char *name)
+{
+ varinfo_t vi;
+ vi = make_constraint_from_heapvar (lhs, name);
+ vi->is_restrict_var = 1;
+ vi->is_global_var = 0;
+ vi->is_special_var = 1;
+ vi->may_have_pointers = 0;
}
+/* 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). */
-/* Handle the structure copy case where we have a structure copy between a
- aggregate on the LHS and a dereference of a pointer on the RHS
- that is of SIZE (in bits)
-
- For each field of the lhs variable (lhsfield)
- rhs.offset = lhsfield->offset
- add the constraint lhsfield = rhs
-*/
+enum { fi_clobbers = 1, fi_uses = 2,
+ fi_static_chain = 3, fi_result = 4, fi_parm_base = 5 };
-static void
-do_rhs_deref_structure_copy (const struct constraint_expr lhs,
- const struct constraint_expr rhs,
- const unsigned HOST_WIDE_INT size)
-{
- varinfo_t p = get_varinfo (lhs.var);
- unsigned HOST_WIDE_INT pstart,last;
- pstart = p->offset;
- last = p->offset + size;
+/* Get a constraint for the requested part of a function designator FI
+ when operating in IPA mode. */
- for (; p && p->offset < last; p = p->next)
- {
- varinfo_t q;
- struct constraint_expr templhs = lhs;
- struct constraint_expr temprhs = rhs;
- unsigned HOST_WIDE_INT fieldoffset;
+static struct constraint_expr
+get_function_part_constraint (varinfo_t fi, unsigned part)
+{
+ struct constraint_expr c;
+ gcc_assert (in_ipa_mode);
- if (templhs.type == SCALAR)
- templhs.var = p->id;
+ 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
- templhs.offset = p->offset;
-
- q = get_varinfo (temprhs.var);
- fieldoffset = p->offset - pstart;
- temprhs.offset += fieldoffset;
- process_constraint (new_constraint (templhs, temprhs));
+ c.var = anything_id;
+ c.offset = 0;
+ c.type = SCALAR;
+ }
+ else
+ {
+ c.var = fi->id;
+ c.offset = part;
+ c.type = DEREF;
}
-}
-/* Handle the structure copy case where we have a structure copy
- between a aggregate on the RHS and a dereference of a pointer on
- the LHS that is of SIZE (in bits)
+ return c;
+}
- For each field of the rhs variable (rhsfield)
- lhs.offset = rhsfield->offset
- add the constraint lhs = rhsfield
-*/
+/* For non-IPA mode, generate constraints necessary for a call on the
+ RHS. */
static void
-do_lhs_deref_structure_copy (const struct constraint_expr lhs,
- const struct constraint_expr rhs,
- const unsigned HOST_WIDE_INT size)
+handle_rhs_call (gimple stmt, VEC(ce_s, heap) **results)
{
- varinfo_t p = get_varinfo (rhs.var);
- unsigned HOST_WIDE_INT pstart,last;
- pstart = p->offset;
- last = p->offset + size;
+ struct constraint_expr rhsc;
+ unsigned i;
- for (; p && p->offset < last; p = p->next)
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
{
- varinfo_t q;
- struct constraint_expr templhs = lhs;
- struct constraint_expr temprhs = rhs;
- unsigned HOST_WIDE_INT fieldoffset;
+ tree arg = gimple_call_arg (stmt, i);
-
- if (temprhs.type == SCALAR)
- temprhs.var = p->id;
- else
- temprhs.offset = p->offset;
-
- q = get_varinfo (templhs.var);
- fieldoffset = p->offset - pstart;
- templhs.offset += fieldoffset;
- process_constraint (new_constraint (templhs, temprhs));
+ /* Find those pointers being passed, and make sure they end up
+ pointing to anything. */
+ if (could_have_pointers (arg))
+ make_escape_constraint (arg);
}
-}
-
-/* Sometimes, frontends like to give us bad type information. This
- function will collapse all the fields from VAR to the end of VAR,
- into VAR, so that we treat those fields as a single variable.
- We return the variable they were collapsed into. */
-static unsigned int
-collapse_rest_of_var (unsigned int var)
-{
- varinfo_t currvar = get_varinfo (var);
- varinfo_t field;
+ /* The static chain escapes as well. */
+ if (gimple_call_chain (stmt))
+ make_escape_constraint (gimple_call_chain (stmt));
- for (field = currvar->next; field; field = field->next)
+ /* 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))))
{
- if (dump_file)
- fprintf (dump_file, "Type safety: Collapsing var %s into %s\n",
- field->name, currvar->name);
-
- gcc_assert (!field->collapsed_to);
- field->collapsed_to = currvar;
+ 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 (i = 0; VEC_iterate (ce_s, tmpc, i, c); ++i)
+ process_constraint (new_constraint (lhsc, *c));
+ VEC_free(ce_s, heap, tmpc);
}
- currvar->next = NULL;
- currvar->size = currvar->fullsize - currvar->offset;
-
- return currvar->id;
+ /* Regular functions return nonlocal memory. */
+ rhsc.var = nonlocal_id;
+ rhsc.offset = 0;
+ rhsc.type = SCALAR;
+ VEC_safe_push (ce_s, heap, *results, &rhsc);
}
-/* Handle aggregate copies by expanding into copies of the respective
- fields of the structures. */
+/* 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
-do_structure_copy (tree lhsop, tree rhsop)
+handle_lhs_call (tree lhs, int flags, VEC(ce_s, heap) *rhsc, tree fndecl)
{
- struct constraint_expr lhs, rhs, tmp;
- VEC (ce_s, heap) *lhsc = NULL, *rhsc = NULL;
- varinfo_t p;
- unsigned HOST_WIDE_INT lhssize;
- unsigned HOST_WIDE_INT rhssize;
-
- get_constraint_for (lhsop, &lhsc);
- get_constraint_for (rhsop, &rhsc);
- gcc_assert (VEC_length (ce_s, lhsc) == 1);
- gcc_assert (VEC_length (ce_s, rhsc) == 1);
- lhs = *(VEC_last (ce_s, lhsc));
- rhs = *(VEC_last (ce_s, rhsc));
-
- VEC_free (ce_s, heap, lhsc);
- VEC_free (ce_s, heap, rhsc);
+ VEC(ce_s, heap) *lhsc = NULL;
- /* If we have special var = x, swap it around. */
- if (lhs.var <= integer_id && !(get_varinfo (rhs.var)->is_special_var))
- {
- tmp = lhs;
- lhs = rhs;
- rhs = tmp;
- }
-
- /* This is fairly conservative for the RHS == ADDRESSOF case, in that it's
- possible it's something we could handle. However, most cases falling
- into this are dealing with transparent unions, which are slightly
- weird. */
- if (rhs.type == ADDRESSOF && !(get_varinfo (rhs.var)->is_special_var))
- {
- rhs.type = ADDRESSOF;
- rhs.var = anything_id;
- }
+ get_constraint_for (lhs, &lhsc);
- /* If the RHS is a special var, or an addressof, set all the LHS fields to
- that special var. */
- if (rhs.var <= integer_id)
+ if (flags & ECF_MALLOC)
{
- for (p = get_varinfo (lhs.var); p; p = p->next)
- {
- struct constraint_expr templhs = lhs;
- struct constraint_expr temprhs = rhs;
-
- if (templhs.type == SCALAR )
- templhs.var = p->id;
- else
- templhs.offset += p->offset;
- process_constraint (new_constraint (templhs, temprhs));
- }
+ varinfo_t vi;
+ vi = make_constraint_from_heapvar (get_vi_for_tree (lhs), "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);
}
- else
+ else if (VEC_length (ce_s, rhsc) > 0)
{
- tree rhstype = TREE_TYPE (rhsop);
- tree lhstype = TREE_TYPE (lhsop);
- tree rhstypesize;
- tree lhstypesize;
-
- lhstypesize = DECL_P (lhsop) ? DECL_SIZE (lhsop) : TYPE_SIZE (lhstype);
- rhstypesize = DECL_P (rhsop) ? DECL_SIZE (rhsop) : TYPE_SIZE (rhstype);
-
- /* If we have a variably sized types on the rhs or lhs, and a deref
- constraint, add the constraint, lhsconstraint = &ANYTHING.
- This is conservatively correct because either the lhs is an unknown
- sized var (if the constraint is SCALAR), or the lhs is a DEREF
- constraint, and every variable it can point to must be unknown sized
- anyway, so we don't need to worry about fields at all. */
- if ((rhs.type == DEREF && TREE_CODE (rhstypesize) != INTEGER_CST)
- || (lhs.type == DEREF && TREE_CODE (lhstypesize) != INTEGER_CST))
- {
- rhs.var = anything_id;
- rhs.type = ADDRESSOF;
- rhs.offset = 0;
- process_constraint (new_constraint (lhs, rhs));
- return;
- }
-
- /* The size only really matters insofar as we don't set more or less of
- the variable. If we hit an unknown size var, the size should be the
- whole darn thing. */
- if (get_varinfo (rhs.var)->is_unknown_size_var)
- rhssize = ~0;
- else
- rhssize = TREE_INT_CST_LOW (rhstypesize);
-
- if (get_varinfo (lhs.var)->is_unknown_size_var)
- lhssize = ~0;
- else
- lhssize = TREE_INT_CST_LOW (lhstypesize);
-
-
- if (rhs.type == SCALAR && lhs.type == SCALAR)
- {
- if (!do_simple_structure_copy (lhs, rhs, MIN (lhssize, rhssize)))
- {
- lhs.var = collapse_rest_of_var (lhs.var);
- rhs.var = collapse_rest_of_var (rhs.var);
- lhs.offset = 0;
- rhs.offset = 0;
- lhs.type = SCALAR;
- rhs.type = SCALAR;
- process_constraint (new_constraint (lhs, rhs));
- }
- }
- else if (lhs.type != DEREF && rhs.type == DEREF)
- do_rhs_deref_structure_copy (lhs, rhs, MIN (lhssize, rhssize));
- else if (lhs.type == DEREF && rhs.type != DEREF)
- do_lhs_deref_structure_copy (lhs, rhs, MIN (lhssize, rhssize));
- else
+ /* 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))
{
- tree pointedtotype = lhstype;
- tree tmpvar;
-
- gcc_assert (rhs.type == DEREF && lhs.type == DEREF);
- tmpvar = create_tmp_var_raw (pointedtotype, "structcopydereftmp");
- do_structure_copy (tmpvar, rhsop);
- do_structure_copy (lhsop, tmpvar);
+ struct constraint_expr tmpc;
+ tmpc.var = escaped_id;
+ tmpc.offset = 0;
+ tmpc.type = SCALAR;
+ VEC_safe_push (ce_s, heap, lhsc, &tmpc);
}
+ process_all_all_constraints (lhsc, rhsc);
}
+ VEC_free (ce_s, heap, lhsc);
}
-/* Update related alias information kept in AI. This is used when
- building name tags, alias sets and deciding grouping heuristics.
- STMT is the statement to process. This function also updates
- ADDRESSABLE_VARS. */
+/* For non-IPA mode, generate constraints necessary for a call of a
+ const function that returns a pointer in the statement STMT. */
static void
-update_alias_info (tree stmt, struct alias_info *ai)
+handle_const_call (gimple stmt, VEC(ce_s, heap) **results)
{
- bitmap addr_taken;
- use_operand_p use_p;
- ssa_op_iter iter;
- enum escape_type stmt_escape_type = is_escape_site (stmt, ai);
- tree op;
+ struct constraint_expr rhsc;
+ unsigned int k;
- /* Mark all the variables whose address are taken by the statement. */
- addr_taken = addresses_taken (stmt);
- if (addr_taken)
+ /* Treat nested const functions the same as pure functions as far
+ as the static chain is concerned. */
+ if (gimple_call_chain (stmt))
{
- bitmap_ior_into (addressable_vars, addr_taken);
-
- /* If STMT is an escape point, all the addresses taken by it are
- call-clobbered. */
- if (stmt_escape_type != NO_ESCAPE)
- {
- bitmap_iterator bi;
- unsigned i;
-
- EXECUTE_IF_SET_IN_BITMAP (addr_taken, 0, i, bi)
- {
- tree rvar = referenced_var (i);
- if (!unmodifiable_var_p (rvar))
- mark_call_clobbered (rvar, stmt_escape_type);
- }
- }
+ 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);
}
- /* Process each operand use. If an operand may be aliased, keep
- track of how many times it's being used. For pointers, determine
- whether they are dereferenced by the statement, or whether their
- value escapes, etc. */
- FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
+ /* May return arguments. */
+ for (k = 0; k < gimple_call_num_args (stmt); ++k)
{
- tree op, var;
- var_ann_t v_ann;
- struct ptr_info_def *pi;
- bool is_store, is_potential_deref;
- unsigned num_uses, num_derefs;
+ tree arg = gimple_call_arg (stmt, k);
- op = USE_FROM_PTR (use_p);
-
- /* If STMT is a PHI node, OP may be an ADDR_EXPR. If so, add it
- to the set of addressable variables. */
- if (TREE_CODE (op) == ADDR_EXPR)
+ if (could_have_pointers (arg))
{
- gcc_assert (TREE_CODE (stmt) == PHI_NODE);
-
- /* PHI nodes don't have annotations for pinning the set
- of addresses taken, so we collect them here.
-
- FIXME, should we allow PHI nodes to have annotations
- so that they can be treated like regular statements?
- Currently, they are treated as second-class
- statements. */
- add_to_addressable_set (TREE_OPERAND (op, 0), &addressable_vars);
- continue;
+ VEC(ce_s, heap) *argc = NULL;
+ unsigned i;
+ struct constraint_expr *argp;
+ get_constraint_for (arg, &argc);
+ for (i = 0; VEC_iterate (ce_s, argc, i, argp); ++i)
+ VEC_safe_push (ce_s, heap, *results, argp);
+ VEC_free(ce_s, heap, argc);
}
+ }
- /* Ignore constants. */
- if (TREE_CODE (op) != SSA_NAME)
- continue;
-
- var = SSA_NAME_VAR (op);
- v_ann = var_ann (var);
-
- /* The base variable of an ssa name must be a GIMPLE register, and thus
- it cannot be aliased. */
- gcc_assert (!may_be_aliased (var));
-
- /* We are only interested in pointers. */
- if (!POINTER_TYPE_P (TREE_TYPE (op)))
- continue;
-
- pi = get_ptr_info (op);
-
- /* Add OP to AI->PROCESSED_PTRS, if it's not there already. */
- if (!TEST_BIT (ai->ssa_names_visited, SSA_NAME_VERSION (op)))
- {
- SET_BIT (ai->ssa_names_visited, SSA_NAME_VERSION (op));
- VEC_safe_push (tree, heap, ai->processed_ptrs, op);
- }
+ /* May return addresses of globals. */
+ rhsc.var = nonlocal_id;
+ rhsc.offset = 0;
+ rhsc.type = ADDRESSOF;
+ VEC_safe_push (ce_s, heap, *results, &rhsc);
+}
- /* If STMT is a PHI node, then it will not have pointer
- dereferences and it will not be an escape point. */
- if (TREE_CODE (stmt) == PHI_NODE)
- continue;
+/* For non-IPA mode, generate constraints necessary for a call to a
+ pure function in statement STMT. */
- /* Determine whether OP is a dereferenced pointer, and if STMT
- is an escape point, whether OP escapes. */
- count_uses_and_derefs (op, stmt, &num_uses, &num_derefs, &is_store);
-
- /* Handle a corner case involving address expressions of the
- form '&PTR->FLD'. The problem with these expressions is that
- they do not represent a dereference of PTR. However, if some
- other transformation propagates them into an INDIRECT_REF
- expression, we end up with '*(&PTR->FLD)' which is folded
- into 'PTR->FLD'.
-
- So, if the original code had no other dereferences of PTR,
- the aliaser will not create memory tags for it, and when
- &PTR->FLD gets propagated to INDIRECT_REF expressions, the
- memory operations will receive no V_MAY_DEF/VUSE operands.
-
- One solution would be to have count_uses_and_derefs consider
- &PTR->FLD a dereference of PTR. But that is wrong, since it
- is not really a dereference but an offset calculation.
-
- What we do here is to recognize these special ADDR_EXPR
- nodes. Since these expressions are never GIMPLE values (they
- are not GIMPLE invariants), they can only appear on the RHS
- of an assignment and their base address is always an
- INDIRECT_REF expression. */
- is_potential_deref = false;
- if (TREE_CODE (stmt) == MODIFY_EXPR
- && TREE_CODE (TREE_OPERAND (stmt, 1)) == ADDR_EXPR
- && !is_gimple_val (TREE_OPERAND (stmt, 1)))
- {
- /* If the RHS if of the form &PTR->FLD and PTR == OP, then
- this represents a potential dereference of PTR. */
- tree rhs = TREE_OPERAND (stmt, 1);
- tree base = get_base_address (TREE_OPERAND (rhs, 0));
- if (TREE_CODE (base) == INDIRECT_REF
- && TREE_OPERAND (base, 0) == op)
- is_potential_deref = true;
- }
+static void
+handle_pure_call (gimple stmt, VEC(ce_s, heap) **results)
+{
+ struct constraint_expr rhsc;
+ unsigned i;
+ varinfo_t uses = NULL;
- if (num_derefs > 0 || is_potential_deref)
- {
- /* Mark OP as dereferenced. In a subsequent pass,
- dereferenced pointers that point to a set of
- variables will be assigned a name tag to alias
- all the variables OP points to. */
- pi->is_dereferenced = 1;
-
- /* Keep track of how many time we've dereferenced each
- pointer. */
- NUM_REFERENCES_INC (v_ann);
-
- /* If this is a store operation, mark OP as being
- dereferenced to store, otherwise mark it as being
- dereferenced to load. */
- if (is_store)
- bitmap_set_bit (ai->dereferenced_ptrs_store, DECL_UID (var));
- else
- bitmap_set_bit (ai->dereferenced_ptrs_load, DECL_UID (var));
- }
+ /* 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 (stmt_escape_type != NO_ESCAPE && num_derefs < num_uses)
+ if (could_have_pointers (arg))
{
- /* If STMT is an escape point and STMT contains at
- least one direct use of OP, then the value of OP
- escapes and so the pointed-to variables need to
- be marked call-clobbered. */
- pi->value_escapes_p = 1;
- pi->escape_mask |= stmt_escape_type;
-
- /* If the statement makes a function call, assume
- that pointer OP will be dereferenced in a store
- operation inside the called function. */
- if (get_call_expr_in (stmt))
+ if (!uses)
{
- bitmap_set_bit (ai->dereferenced_ptrs_store, DECL_UID (var));
- pi->is_dereferenced = 1;
+ uses = get_call_use_vi (stmt);
+ make_transitive_closure_constraints (uses);
}
+ make_constraint_to (uses->id, arg);
}
}
- if (TREE_CODE (stmt) == PHI_NODE)
- return;
-
- /* Update reference counter for definitions to any
- potentially aliased variable. This is used in the alias
- grouping heuristics. */
- FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
+ /* The static chain is used as well. */
+ if (gimple_call_chain (stmt))
{
- tree var = SSA_NAME_VAR (op);
- var_ann_t ann = var_ann (var);
- bitmap_set_bit (ai->written_vars, DECL_UID (var));
- if (may_be_aliased (var))
- NUM_REFERENCES_INC (ann);
-
+ if (!uses)
+ {
+ uses = get_call_use_vi (stmt);
+ make_transitive_closure_constraints (uses);
+ }
+ make_constraint_to (uses->id, gimple_call_chain (stmt));
}
-
- /* Mark variables in V_MAY_DEF operands as being written to. */
- FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_VIRTUAL_DEFS)
+
+ /* Pure functions may return call-used and nonlocal memory. */
+ if (uses)
{
- tree var = DECL_P (op) ? op : SSA_NAME_VAR (op);
- bitmap_set_bit (ai->written_vars, DECL_UID (var));
+ 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);
}
-/* Handle pointer arithmetic EXPR when creating aliasing constraints.
- Expressions of the type PTR + CST can be handled in two ways:
+/* Return the varinfo for the callee of CALL. */
- 1- If the constraint for PTR is ADDRESSOF for a non-structure
- variable, then we can use it directly because adding or
- subtracting a constant may not alter the original ADDRESSOF
- constraint (i.e., pointer arithmetic may not legally go outside
- an object's boundaries).
-
- 2- If the constraint for PTR is ADDRESSOF for a structure variable,
- then if CST is a compile-time constant that can be used as an
- offset, we can determine which sub-variable will be pointed-to
- by the expression.
-
- Return true if the expression is handled. For any other kind of
- expression, return false so that each operand can be added as a
- separate constraint by the caller. */
-
-static bool
-handle_ptr_arith (VEC (ce_s, heap) *lhsc, tree expr)
+static varinfo_t
+get_fi_for_callee (gimple call)
{
- tree op0, op1;
- struct constraint_expr *c, *c2;
- unsigned int i = 0;
- unsigned int j = 0;
- VEC (ce_s, heap) *temp = NULL;
- unsigned int rhsoffset = 0;
-
- if (TREE_CODE (expr) != PLUS_EXPR
- && TREE_CODE (expr) != MINUS_EXPR)
- return false;
-
- op0 = TREE_OPERAND (expr, 0);
- op1 = TREE_OPERAND (expr, 1);
+ tree decl;
- get_constraint_for (op0, &temp);
- if (POINTER_TYPE_P (TREE_TYPE (op0))
- && TREE_CODE (op1) == INTEGER_CST
- && TREE_CODE (expr) == PLUS_EXPR)
+ /* 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_fndecl (call);
+ if (decl)
+ return get_vi_for_tree (decl);
+
+ decl = gimple_call_fn (call);
+ /* The function can be either an SSA name pointer or,
+ worse, an OBJ_TYPE_REF. In this case we have no
+ clue and should be getting ANYFN (well, ANYTHING for now). */
+ if (TREE_CODE (decl) == SSA_NAME)
{
- rhsoffset = TREE_INT_CST_LOW (op1) * BITS_PER_UNIT;
+ if (TREE_CODE (decl) == SSA_NAME
+ && TREE_CODE (SSA_NAME_VAR (decl)) == PARM_DECL
+ && SSA_NAME_IS_DEFAULT_DEF (decl))
+ decl = SSA_NAME_VAR (decl);
+ return get_vi_for_tree (decl);
}
-
-
- for (i = 0; VEC_iterate (ce_s, lhsc, i, c); i++)
- for (j = 0; VEC_iterate (ce_s, temp, j, c2); j++)
- {
- if (c2->type == ADDRESSOF && rhsoffset != 0)
- {
- varinfo_t temp = get_varinfo (c2->var);
-
- /* An access one after the end of an array is valid,
- so simply punt on accesses we cannot resolve. */
- temp = first_vi_for_offset (temp, rhsoffset);
- if (temp == NULL)
- continue;
- c2->var = temp->id;
- c2->offset = 0;
- }
- else
- c2->offset = rhsoffset;
- process_constraint (new_constraint (*c, *c2));
- }
-
- VEC_free (ce_s, heap, temp);
-
- return true;
+ else if (TREE_CODE (decl) == INTEGER_CST
+ || TREE_CODE (decl) == OBJ_TYPE_REF)
+ return get_varinfo (anything_id);
+ else
+ gcc_unreachable ();
}
-
/* 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 (tree origt)
+find_func_aliases (gimple origt)
{
- tree t = origt;
+ gimple t = origt;
VEC(ce_s, heap) *lhsc = NULL;
VEC(ce_s, heap) *rhsc = NULL;
struct constraint_expr *c;
-
- if (TREE_CODE (t) == RETURN_EXPR && TREE_OPERAND (t, 0))
- t = TREE_OPERAND (t, 0);
+ varinfo_t fi;
/* Now build constraints expressions. */
- if (TREE_CODE (t) == PHI_NODE)
+ if (gimple_code (t) == GIMPLE_PHI)
{
- gcc_assert (!AGGREGATE_TYPE_P (TREE_TYPE (PHI_RESULT (t))));
+ gcc_assert (!AGGREGATE_TYPE_P (TREE_TYPE (gimple_phi_result (t))));
/* Only care about pointers and structures containing
pointers. */
- if (POINTER_TYPE_P (TREE_TYPE (PHI_RESULT (t)))
- || TREE_CODE (TREE_TYPE (PHI_RESULT (t))) == COMPLEX_TYPE)
+ if (could_have_pointers (gimple_phi_result (t)))
{
- int i;
+ size_t i;
unsigned int j;
-
+
/* For a phi node, assign all the arguments to
the result. */
- get_constraint_for (PHI_RESULT (t), &lhsc);
- for (i = 0; i < PHI_NUM_ARGS (t); i++)
- {
- tree rhstype;
+ 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);
- rhstype = TREE_TYPE (strippedrhs);
- get_constraint_for (PHI_ARG_DEF (t, i), &rhsc);
+ get_constraint_for (gimple_phi_arg_def (t, i), &rhsc);
for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
{
VEC_pop (ce_s, rhsc);
}
}
- }
+ }
}
}
/* In IPA mode, we need to generate constraints to pass call
- arguments through their calls. There are two case, either a
- modify_expr when we are returning a value, or just a plain
- call_expr when we are not. */
- else if (in_ipa_mode
- && ((TREE_CODE (t) == MODIFY_EXPR
- && TREE_CODE (TREE_OPERAND (t, 1)) == CALL_EXPR
- && !(call_expr_flags (TREE_OPERAND (t, 1))
- & (ECF_MALLOC | ECF_MAY_BE_ALLOCA)))
- || (TREE_CODE (t) == CALL_EXPR
- && !(call_expr_flags (t)
- & (ECF_MALLOC | ECF_MAY_BE_ALLOCA)))))
- {
- tree lhsop;
- tree rhsop;
- unsigned int varid;
- tree arglist;
- varinfo_t fi;
- int i = 1;
- tree decl;
- if (TREE_CODE (t) == MODIFY_EXPR)
+ 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))
+ {
+ tree fndecl = gimple_call_fndecl (t);
+ 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:
+ {
+ 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)
+ 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;
+ }
+ case BUILT_IN_MEMSET:
+ {
+ 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 (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
+ process_constraint (new_constraint (*lhsp, ac));
+ VEC_free (ce_s, heap, lhsc);
+ return;
+ }
+ /* 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;
+ /* 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 (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
+ 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;
+ }
+ }
+ /* 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;
+ }
+ /* Variadic argument handling needs to be handled in IPA
+ mode as well. */
+ case BUILT_IN_VA_START:
+ {
+ if (in_ipa_mode)
+ {
+ tree valist = gimple_call_arg (t, 0);
+ struct constraint_expr rhs, *lhsp;
+ unsigned i;
+ /* The va_list gets access to pointers in variadic
+ arguments. */
+ fi = lookup_vi_for_tree (cfun->decl);
+ gcc_assert (fi != NULL);
+ get_constraint_for (valist, &lhsc);
+ do_deref (&lhsc);
+ rhs = get_function_part_constraint (fi, ~0);
+ rhs.type = ADDRESSOF;
+ for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
+ 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;
+ }
+ break;
+ }
+ /* va_end doesn't have any effect that matters. */
+ 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. */;
+ }
+ if (!in_ipa_mode
+ || (fndecl
+ && (!(fi = lookup_vi_for_tree (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)
+ && could_have_pointers (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)
+ && could_have_pointers (gimple_call_lhs (t)))
+ handle_lhs_call (gimple_call_lhs (t), flags, rhsc, fndecl);
+ VEC_free (ce_s, heap, rhsc);
+ }
+ else
{
- lhsop = TREE_OPERAND (t, 0);
- rhsop = TREE_OPERAND (t, 1);
+ tree lhsop;
+ unsigned j;
+
+ fi = get_fi_for_callee (t);
+
+ /* 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);
+
+ if (!could_have_pointers (arg))
+ continue;
+
+ get_constraint_for (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
+ && could_have_pointers (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 (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ 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 (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
+ 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 (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
+ process_constraint (new_constraint (lhs, *rhsp));
+ }
}
+ }
+ /* 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)
+ && could_have_pointers (gimple_assign_lhs (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
{
- lhsop = NULL;
- rhsop = t;
+ struct constraint_expr temp;
+ get_constraint_for (lhsop, &lhsc);
+
+ if (gimple_assign_rhs_code (t) == POINTER_PLUS_EXPR)
+ get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
+ gimple_assign_rhs2 (t), &rhsc);
+ else if ((CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (t))
+ && !(POINTER_TYPE_P (gimple_expr_type (t))
+ && !POINTER_TYPE_P (TREE_TYPE (rhsop))))
+ || gimple_assign_single_p (t))
+ get_constraint_for (rhsop, &rhsc);
+ else
+ {
+ temp.type = ADDRESSOF;
+ temp.var = anything_id;
+ temp.offset = 0;
+ VEC_safe_push (ce_s, heap, rhsc, &temp);
+ }
+ 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);
+ /* If this is a conversion of a non-restrict pointer to a
+ restrict pointer track it with a new heapvar. */
+ else if (gimple_assign_cast_p (t)
+ && POINTER_TYPE_P (TREE_TYPE (rhsop))
+ && POINTER_TYPE_P (TREE_TYPE (lhsop))
+ && !TYPE_RESTRICT (TREE_TYPE (rhsop))
+ && TYPE_RESTRICT (TREE_TYPE (lhsop)))
+ make_constraint_from_restrict (get_vi_for_tree (lhsop),
+ "CAST_RESTRICT");
+ }
+ /* For conversions of pointers to non-pointers the pointer escapes. */
+ else if (gimple_assign_cast_p (t)
+ && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (t)))
+ && !POINTER_TYPE_P (TREE_TYPE (gimple_assign_lhs (t))))
+ {
+ make_escape_constraint (gimple_assign_rhs1 (t));
+ }
+ /* Handle escapes through return. */
+ else if (gimple_code (t) == GIMPLE_RETURN
+ && gimple_return_retval (t) != NULL_TREE
+ && could_have_pointers (gimple_return_retval (t)))
+ {
+ 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 (gimple_return_retval (t), &rhsc);
+ for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
+ process_constraint (new_constraint (lhs, *rhsp));
}
- decl = get_callee_fndecl (rhsop);
+ }
+ /* 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);
- /* 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. */
- if (decl)
+ for (i = 0; i < noutputs; ++i)
{
- varid = get_id_for_tree (decl);
+ 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 && could_have_pointers (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 (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhsc));
+ VEC_free (ce_s, heap, lhsc);
+ }
}
- else
+ 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 && could_have_pointers (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 (ptr, &ptrc);
+ lhs = get_function_part_constraint (fi, fi_clobbers);
+ for (i = 0; VEC_iterate (ce_s, ptrc, i, c); i++)
+ 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))
{
- decl = TREE_OPERAND (rhsop, 0);
- varid = get_id_for_tree (decl);
+ struct constraint_expr lhsc, *rhsp;
+ unsigned i;
+ lhsc = get_function_part_constraint (fi, fi_clobbers);
+ get_constraint_for_address_of (lhs, &rhsc);
+ for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
+ process_constraint (new_constraint (lhsc, *rhsp));
+ VEC_free (ce_s, heap, rhsc);
}
+ }
- /* Assign all the passed arguments to the appropriate incoming
- parameters of the function. */
- fi = get_varinfo (varid);
- arglist = TREE_OPERAND (rhsop, 1);
-
- for (;arglist; arglist = TREE_CHAIN (arglist))
+ /* 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 arg = TREE_VALUE (arglist);
- struct constraint_expr lhs ;
- struct constraint_expr *rhsp;
+ struct constraint_expr lhs, *rhsp;
+ unsigned i;
+ lhs = get_function_part_constraint (fi, fi_uses);
+ get_constraint_for_address_of (rhs, &rhsc);
+ for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
+ process_constraint (new_constraint (lhs, *rhsp));
+ VEC_free (ce_s, heap, rhsc);
+ }
+ }
- get_constraint_for (arg, &rhsc);
- if (TREE_CODE (decl) != FUNCTION_DECL)
+ 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:
{
- lhs.type = DEREF;
- lhs.var = fi->id;
- lhs.offset = i;
+ 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 (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); i++)
+ 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 (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); i++)
+ process_constraint (new_constraint (lhs, *rhsp));
+ VEC_free (ce_s, heap, rhsc);
+ return;
}
- else
+ /* The following function clobbers memory pointed to by
+ its argument. */
+ case BUILT_IN_MEMSET:
{
- lhs.type = SCALAR;
- lhs.var = first_vi_for_offset (fi, i)->id;
- lhs.offset = 0;
+ 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 (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); i++)
+ process_constraint (new_constraint (lhs, *lhsp));
+ VEC_free (ce_s, heap, lhsc);
+ return;
}
- while (VEC_length (ce_s, rhsc) != 0)
+ /* The following functions clobber their second and third
+ arguments. */
+ case BUILT_IN_SINCOS:
+ case BUILT_IN_SINCOSF:
+ case BUILT_IN_SINCOSL:
{
- rhsp = VEC_last (ce_s, rhsc);
- process_constraint (new_constraint (lhs, *rhsp));
- VEC_pop (ce_s, rhsc);
+ process_ipa_clobber (fi, gimple_call_arg (t, 1));
+ process_ipa_clobber (fi, gimple_call_arg (t, 2));
+ return;
}
- i++;
- }
- /* If we are returning a value, assign it to the result. */
- if (lhsop)
- {
- struct constraint_expr rhs;
- struct constraint_expr *lhsp;
- unsigned int j = 0;
-
- get_constraint_for (lhsop, &lhsc);
- if (TREE_CODE (decl) != FUNCTION_DECL)
+ /* 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:
{
- rhs.type = DEREF;
- rhs.var = fi->id;
- rhs.offset = i;
+ process_ipa_clobber (fi, gimple_call_arg (t, 1));
+ return;
}
- else
+ /* The following functions clobber their third argument. */
+ case BUILT_IN_REMQUO:
+ case BUILT_IN_REMQUOF:
+ case BUILT_IN_REMQUOL:
{
- rhs.type = SCALAR;
- rhs.var = first_vi_for_offset (fi, i)->id;
- rhs.offset = 0;
+ process_ipa_clobber (fi, gimple_call_arg (t, 2));
+ return;
}
- for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
- process_constraint (new_constraint (*lhsp, rhs));
- }
- }
- /* Otherwise, just a regular assignment statement. */
- else if (TREE_CODE (t) == MODIFY_EXPR)
- {
- tree lhsop = TREE_OPERAND (t, 0);
- tree rhsop = TREE_OPERAND (t, 1);
- int i;
+ /* The following functions neither read nor clobber memory. */
+ 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 (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); j++)
+ process_constraint (new_constraint (lhs, *rhsp));
+ VEC_free (ce_s, heap, rhsc);
+ }
- if ((AGGREGATE_TYPE_P (TREE_TYPE (lhsop))
- || TREE_CODE (TREE_TYPE (lhsop)) == COMPLEX_TYPE)
- && (AGGREGATE_TYPE_P (TREE_TYPE (rhsop))
- || TREE_CODE (TREE_TYPE (lhsop)) == COMPLEX_TYPE))
+ /* Build constraints for propagating clobbers/uses along the
+ callgraph edges. */
+ cfi = get_fi_for_callee (t);
+ if (cfi->id == anything_id)
{
- do_structure_copy (lhsop, rhsop);
+ 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;
}
- else
+
+ /* For callees without function info (that's external functions),
+ ESCAPED is clobbered and used. */
+ if (gimple_call_fndecl (t)
+ && !cfi->is_fn_info)
{
- /* Only care about operations with pointers, structures
- containing pointers, dereferences, and call expressions. */
- if (POINTER_TYPE_P (TREE_TYPE (lhsop))
- || AGGREGATE_TYPE_P (TREE_TYPE (lhsop))
- || TREE_CODE (TREE_TYPE (lhsop)) == COMPLEX_TYPE
- || TREE_CODE (rhsop) == CALL_EXPR)
- {
- get_constraint_for (lhsop, &lhsc);
- switch (TREE_CODE_CLASS (TREE_CODE (rhsop)))
- {
- /* RHS that consist of unary operations,
- exceptional types, or bare decls/constants, get
- handled directly by get_constraint_for. */
- case tcc_reference:
- case tcc_declaration:
- case tcc_constant:
- case tcc_exceptional:
- case tcc_expression:
- case tcc_unary:
- {
- unsigned int j;
-
- get_constraint_for (rhsop, &rhsc);
- for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
- {
- struct constraint_expr *c2;
- unsigned int k;
-
- for (k = 0; VEC_iterate (ce_s, rhsc, k, c2); k++)
- process_constraint (new_constraint (*c, *c2));
- }
-
- }
- break;
+ varinfo_t vi;
- case tcc_binary:
- {
- /* For pointer arithmetic of the form
- PTR + CST, we can simply use PTR's
- constraint because pointer arithmetic is
- not allowed to go out of bounds. */
- if (handle_ptr_arith (lhsc, rhsop))
- break;
- }
- /* FALLTHRU */
-
- /* Otherwise, walk each operand. Notice that we
- can't use the operand interface because we need
- to process expressions other than simple operands
- (e.g. INDIRECT_REF, ADDR_EXPR, CALL_EXPR). */
- default:
- for (i = 0; i < TREE_CODE_LENGTH (TREE_CODE (rhsop)); i++)
- {
- tree op = TREE_OPERAND (rhsop, i);
- unsigned int j;
-
- gcc_assert (VEC_length (ce_s, rhsc) == 0);
- get_constraint_for (op, &rhsc);
- for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
- {
- 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);
- }
- }
- }
- }
- }
+ 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);
}
- /* After promoting variables and computing aliasing we will
- need to re-scan most statements. FIXME: Try to minimize the
- number of statements re-scanned. It's not really necessary to
- re-scan *all* statements. */
- mark_stmt_modified (origt);
VEC_free (ce_s, heap, rhsc);
- VEC_free (ce_s, heap, lhsc);
}
/* Find the first varinfo in the same variable as START that overlaps with
- OFFSET.
- Effectively, walk the chain of fields for the variable START to find the
- first field that overlaps with OFFSET.
- Return NULL if we can't find one. */
+ OFFSET. Return NULL if we can't find one. */
-static varinfo_t
+static varinfo_t
first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
{
- varinfo_t curr = start;
- while (curr)
+ /* 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 >= curr->offset && offset < (curr->offset + curr->size))
- return curr;
- curr = curr->next;
+ 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. */
-/* Insert the varinfo FIELD into the field list for BASE, at the front
- of the list. */
-
-static void
-insert_into_field_list (varinfo_t base, varinfo_t field)
+static varinfo_t
+first_or_preceding_vi_for_offset (varinfo_t start,
+ unsigned HOST_WIDE_INT offset)
{
- varinfo_t prev = base;
- varinfo_t curr = base->next;
-
- field->next = curr;
- prev->next = field;
+ /* 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;
}
-/* Insert the varinfo FIELD into the field list for BASE, ordered by
- offset. */
-static void
-insert_into_field_list_sorted (varinfo_t base, varinfo_t field)
+/* 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
{
- varinfo_t prev = base;
- varinfo_t curr = base->next;
-
- if (curr == NULL)
- {
- prev->next = field;
- field->next = NULL;
- }
- else
- {
- while (curr)
- {
- if (field->offset <= curr->offset)
- break;
- prev = curr;
- curr = curr->next;
- }
- field->next = prev->next;
- prev->next = field;
- }
-}
+ /* 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 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
+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;
- HOST_WIDE_INT foasize, fobsize;
-
- if (foa->offset != fob->offset)
- return foa->offset - fob->offset;
+ unsigned HOST_WIDE_INT foasize, fobsize;
+
+ if (foa->offset < fob->offset)
+ return -1;
+ else if (foa->offset > fob->offset)
+ return 1;
- foasize = TREE_INT_CST_LOW (foa->size);
- fobsize = TREE_INT_CST_LOW (fob->size);
- return foasize - fobsize;
+ 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. */
-void sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
+static void
+sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
{
- qsort (VEC_address (fieldoff_s, fieldstack),
- VEC_length (fieldoff_s, fieldstack),
+ qsort (VEC_address (fieldoff_s, fieldstack),
+ VEC_length (fieldoff_s, fieldstack),
sizeof (fieldoff_s),
fieldoff_compare);
}
-/* 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 the number
- of fields pushed.
- HAS_UNION is set to true if we find a union type as a field of
- TYPE. */
+/* 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. */
-int
-push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
- HOST_WIDE_INT offset, bool *has_union)
+static inline bool
+var_can_have_subvars (const_tree v)
{
- tree field;
- int count = 0;
-
- if (TREE_CODE (type) == COMPLEX_TYPE)
- {
- fieldoff_s *real_part, *img_part;
- real_part = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
- real_part->type = TREE_TYPE (type);
- real_part->size = TYPE_SIZE (TREE_TYPE (type));
- real_part->offset = offset;
- real_part->decl = NULL_TREE;
-
- img_part = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
- img_part->type = TREE_TYPE (type);
- img_part->size = TYPE_SIZE (TREE_TYPE (type));
- img_part->offset = offset + TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (type)));
- img_part->decl = NULL_TREE;
-
- return 2;
- }
+ /* Volatile variables should never have subvars. */
+ if (TREE_THIS_VOLATILE (v))
+ return false;
- if (TREE_CODE (type) == ARRAY_TYPE)
- {
- tree sz = TYPE_SIZE (type);
- tree elsz = TYPE_SIZE (TREE_TYPE (type));
- HOST_WIDE_INT nr;
- int i;
+ /* Non decls or memory tags can never have subvars. */
+ if (!DECL_P (v))
+ return false;
- if (! sz
- || ! host_integerp (sz, 1)
- || TREE_INT_CST_LOW (sz) == 0
- || ! elsz
- || ! host_integerp (elsz, 1)
- || TREE_INT_CST_LOW (elsz) == 0)
- return 0;
+ /* Aggregates without overlapping fields can have subvars. */
+ if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE)
+ return true;
- nr = TREE_INT_CST_LOW (sz) / TREE_INT_CST_LOW (elsz);
- if (nr > SALIAS_MAX_ARRAY_ELEMENTS)
- return 0;
+ return false;
+}
- for (i = 0; i < nr; ++i)
- {
- bool push = false;
- int pushed = 0;
-
- if (has_union
- && (TREE_CODE (TREE_TYPE (type)) == QUAL_UNION_TYPE
- || TREE_CODE (TREE_TYPE (type)) == UNION_TYPE))
- *has_union = true;
-
- if (!AGGREGATE_TYPE_P (TREE_TYPE (type))) /* var_can_have_subvars */
- push = true;
- else if (!(pushed = push_fields_onto_fieldstack
- (TREE_TYPE (type), fieldstack,
- offset + i * TREE_INT_CST_LOW (elsz), has_union)))
- /* 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;
-
- pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
- pair->type = TREE_TYPE (type);
- pair->size = elsz;
- pair->decl = NULL_TREE;
- pair->offset = offset + i * TREE_INT_CST_LOW (elsz);
- count++;
- }
- else
- count += pushed;
- }
+/* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
+ the fields of TYPE onto fieldstack, recording their offsets along
+ the way.
- return count;
- }
+ 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 = TREE_CHAIN (field))
if (TREE_CODE (field) == FIELD_DECL)
{
bool push = false;
- int pushed = 0;
-
- if (has_union
- && (TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE
- || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
- *has_union = true;
-
- if (!var_can_have_subvars (field))
+ 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 (!(pushed = push_fields_onto_fieldstack
- (TREE_TYPE (field), fieldstack,
- offset + bitpos_of_field (field), has_union))
- && DECL_SIZE (field)
- && !integer_zerop (DECL_SIZE (field)))
- /* Empty structures may have actual size, like in C++. So
+ 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 */
+ nonzero, push the field onto the stack. */
push = true;
-
+
if (push)
{
- fieldoff_s *pair;
-
- pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
- pair->type = TREE_TYPE (field);
- pair->size = DECL_SIZE (field);
- pair->decl = field;
- pair->offset = offset + bitpos_of_field (field);
- count++;
+ fieldoff_s *pair = NULL;
+ bool has_unknown_size = false;
+
+ if (!VEC_empty (fieldoff_s, *fieldstack))
+ pair = VEC_last (fieldoff_s, *fieldstack);
+
+ if (!DECL_SIZE (field)
+ || !host_integerp (DECL_SIZE (field), 1))
+ has_unknown_size = true;
+
+ /* If adjacent fields do not contain pointers merge them. */
+ if (pair
+ && !pair->may_have_pointers
+ && !pair->has_unknown_size
+ && !has_unknown_size
+ && pair->offset + (HOST_WIDE_INT)pair->size == offset + foff
+ && !could_have_pointers (field))
+ {
+ 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->may_have_pointers = could_have_pointers (field);
+ pair->only_restrict_pointers
+ = (!has_unknown_size
+ && POINTER_TYPE_P (TREE_TYPE (field))
+ && TYPE_RESTRICT (TREE_TYPE (field)));
+ }
}
- else
- count += pushed;
- }
- return count;
-}
+ empty_p = false;
+ }
-static void
-make_constraint_to_anything (varinfo_t vi)
-{
- struct constraint_expr lhs, rhs;
-
- lhs.var = vi->id;
- lhs.offset = 0;
- lhs.type = SCALAR;
-
- rhs.var = anything_id;
- rhs.offset =0 ;
- rhs.type = ADDRESSOF;
- process_constraint (new_constraint (lhs, rhs));
+ return !empty_p;
}
/* Count the number of arguments DECL has, and set IS_VARARGS to true
static unsigned int
count_num_arguments (tree decl, bool *is_varargs)
{
- unsigned int i = 0;
+ unsigned int num = 0;
tree t;
- for (t = TYPE_ARG_TYPES (TREE_TYPE (decl));
- t;
- t = TREE_CHAIN (t))
- {
- if (TREE_VALUE (t) == void_type_node)
- break;
- i++;
- }
-
+ /* 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 = TREE_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 i;
+
+ return num;
}
/* Creation function node for DECL, using NAME, and return the index
static unsigned int
create_function_info_for (tree decl, const char *name)
{
- unsigned int index = VEC_length (varinfo_t, varmap);
- varinfo_t vi;
- tree arg;
+ 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, index, name, index);
- vi->decl = decl;
+ vi = new_var_info (decl, name);
vi->offset = 0;
- vi->has_union = 0;
vi->size = 1;
- vi->fullsize = count_num_arguments (decl, &is_varargs) + 1;
- insert_id_for_tree (vi->decl, index);
- VEC_safe_push (varinfo_t, heap, varmap, vi);
+ 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);
- stats.total_vars++;
+ prev_vi = vi;
- /* If it's varargs, we don't know how many arguments it has, so we
- can't do much.
- */
- if (is_varargs)
+ /* Create a variable for things the function clobbers and one for
+ things the function uses. */
{
- vi->fullsize = ~0;
- vi->size = ~0;
- vi->is_unknown_size_var = true;
- return index;
+ 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;
}
-
- arg = DECL_ARGUMENTS (decl);
+ /* 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 = could_have_pointers (DECL_RESULT (decl));
+ 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. */
- for (i = 1; i < vi->fullsize; i++)
- {
+ arg = DECL_ARGUMENTS (decl);
+ for (i = 0; i < num_args; i++)
+ {
varinfo_t argvi;
const char *newname;
char *tempname;
- unsigned int newindex;
tree argdecl = decl;
if (arg)
argdecl = arg;
-
- newindex = VEC_length (varinfo_t, varmap);
- asprintf (&tempname, "%s.arg%d", name, i-1);
+
+ asprintf (&tempname, "%s.arg%d", name, i);
newname = ggc_strdup (tempname);
free (tempname);
- argvi = new_var_info (argdecl, newindex,newname, newindex);
- argvi->decl = argdecl;
- VEC_safe_push (varinfo_t, heap, varmap, argvi);
- argvi->offset = i;
+ argvi = new_var_info (argdecl, newname);
+ argvi->offset = fi_parm_base + i;
argvi->size = 1;
+ argvi->is_full_var = true;
argvi->fullsize = vi->fullsize;
- argvi->has_union = false;
- insert_into_field_list_sorted (vi, argvi);
- stats.total_vars ++;
+ if (arg)
+ argvi->may_have_pointers = could_have_pointers (arg);
+ gcc_assert (prev_vi->offset < argvi->offset);
+ prev_vi->next = argvi;
+ prev_vi = argvi;
if (arg)
{
- insert_id_for_tree (arg, newindex);
+ insert_vi_for_tree (arg, argvi);
arg = TREE_CHAIN (arg);
}
}
- /* Create a variable for the return var. */
- if (DECL_RESULT (decl) != NULL
- || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
+ /* Add one representative for all further args. */
+ if (is_varargs)
{
- varinfo_t resultvi;
+ varinfo_t argvi;
const char *newname;
char *tempname;
- unsigned int newindex;
- tree resultdecl = decl;
-
- vi->fullsize ++;
+ tree decl;
- if (DECL_RESULT (decl))
- resultdecl = DECL_RESULT (decl);
-
- newindex = VEC_length (varinfo_t, varmap);
- asprintf (&tempname, "%s.result", name);
+ asprintf (&tempname, "%s.varargs", name);
newname = ggc_strdup (tempname);
free (tempname);
- resultvi = new_var_info (resultdecl, newindex, newname, newindex);
- resultvi->decl = resultdecl;
- VEC_safe_push (varinfo_t, heap, varmap, resultvi);
- resultvi->offset = i;
- resultvi->size = 1;
- resultvi->fullsize = vi->fullsize;
- resultvi->has_union = false;
- insert_into_field_list_sorted (vi, resultvi);
- stats.total_vars ++;
- if (DECL_RESULT (decl))
- insert_id_for_tree (DECL_RESULT (decl), newindex);
+ /* We need sth that can be pointed to for va_start. */
+ decl = create_tmp_var_raw (ptr_type_node, name);
+ get_var_ann (decl);
+
+ 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 index;
-}
+
+ return vi->id;
+}
-/* Return true if FIELDSTACK contains fields that overlap.
+/* Return true if FIELDSTACK contains fields that overlap.
FIELDSTACK is assumed to be sorted by offset. */
static bool
}
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 unsigned int
-create_variable_info_for (tree decl, const char *name)
+static varinfo_t
+create_variable_info_for_1 (tree decl, const char *name)
{
- unsigned int index = VEC_length (varinfo_t, varmap);
- varinfo_t vi;
- tree decltype = TREE_TYPE (decl);
- tree declsize = DECL_P (decl) ? DECL_SIZE (decl) : TYPE_SIZE (decltype);
- bool notokay = false;
- bool hasunion;
- bool is_global = DECL_P (decl) ? is_global_var (decl) : false;
+ 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;
-
- if (TREE_CODE (decl) == FUNCTION_DECL && in_ipa_mode)
- return create_function_info_for (decl, name);
-
- hasunion = TREE_CODE (decltype) == UNION_TYPE
- || TREE_CODE (decltype) == QUAL_UNION_TYPE;
- if (var_can_have_subvars (decl) && use_field_sensitive && !hasunion)
- {
- push_fields_onto_fieldstack (decltype, &fieldstack, 0, &hasunion);
- if (hasunion)
- {
- VEC_free (fieldoff_s, heap, fieldstack);
- notokay = true;
- }
- }
-
+ fieldoff_s *fo;
+ unsigned int i;
- /* If the variable doesn't have subvars, we may end up needing to
- sort the field list and create fake variables for all the
- fields. */
- vi = new_var_info (decl, index, name, index);
- vi->decl = decl;
- vi->offset = 0;
- vi->has_union = hasunion;
if (!declsize
- || TREE_CODE (declsize) != INTEGER_CST
- || TREE_CODE (decltype) == UNION_TYPE
- || TREE_CODE (decltype) == QUAL_UNION_TYPE)
+ || !host_integerp (declsize, 1))
{
- vi->is_unknown_size_var = true;
- vi->fullsize = ~0;
+ 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 = could_have_pointers (decl);
+ return vi;
}
- else
- {
- vi->fullsize = TREE_INT_CST_LOW (declsize);
- vi->size = vi->fullsize;
- }
-
- insert_id_for_tree (vi->decl, index);
- VEC_safe_push (varinfo_t, heap, varmap, vi);
- if (is_global && (!flag_whole_program || !in_ipa_mode))
- make_constraint_to_anything (vi);
- stats.total_vars++;
- if (use_field_sensitive
- && !notokay
- && !vi->is_unknown_size_var
+ /* Collect field information. */
+ if (use_field_sensitive
&& var_can_have_subvars (decl)
- && VEC_length (fieldoff_s, fieldstack) <= MAX_FIELDS_FOR_FIELD_SENSITIVE)
+ /* ??? 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)))
{
- unsigned int newindex = VEC_length (varinfo_t, varmap);
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->size
- || TREE_CODE (fo->size) != INTEGER_CST
- || fo->offset < 0)
- {
- notokay = true;
- break;
- }
- }
+ 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,
we will simply disable field-sensitivity for these cases. */
notokay = check_for_overlaps (fieldstack);
}
-
-
- if (VEC_length (fieldoff_s, fieldstack) != 0)
- fo = VEC_index (fieldoff_s, fieldstack, 0);
- if (fo == NULL || notokay)
- {
- vi->is_unknown_size_var = 1;
- vi->fullsize = ~0;
- vi->size = ~0;
- VEC_free (fieldoff_s, heap, fieldstack);
- return index;
- }
-
- vi->size = TREE_INT_CST_LOW (fo->size);
- vi->offset = fo->offset;
- for (i = VEC_length (fieldoff_s, fieldstack) - 1;
- i >= 1 && VEC_iterate (fieldoff_s, fieldstack, i, fo);
- i--)
- {
- varinfo_t newvi;
- const char *newname = "NULL";
- char *tempname;
+ 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 = could_have_pointers (decl);
+ 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);
- newindex = VEC_length (varinfo_t, varmap);
- if (dump_file)
+ /* 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_restrict (vi, "GLOBAL_RESTRICT");
+
+ /* For escaped variables initialize them from nonlocal. */
+ if (!in_ipa_mode
+ || DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
+ 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. In non-IPA mode
+ the initializer from nonlocal is all we need. */
+ if (in_ipa_mode
+ && DECL_INITIAL (decl))
+ {
+ VEC (ce_s, heap) *rhsc = NULL;
+ struct constraint_expr lhs, *rhsp;
+ unsigned i;
+ get_constraint_for (DECL_INITIAL (decl), &rhsc);
+ lhs.var = vi->id;
+ lhs.offset = 0;
+ lhs.type = SCALAR;
+ for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
+ process_constraint (new_constraint (lhs, *rhsp));
+ /* If this is a variable that escapes from the unit
+ the initializer escapes as well. */
+ if (DECL_EXTERNAL (decl) || TREE_PUBLIC (decl))
{
- if (fo->decl)
- asprintf (&tempname, "%s.%s",
- vi->name, alias_get_name (fo->decl));
- else
- asprintf (&tempname, "%s." HOST_WIDE_INT_PRINT_DEC,
- vi->name, fo->offset);
- newname = ggc_strdup (tempname);
- free (tempname);
+ lhs.var = escaped_id;
+ lhs.offset = 0;
+ lhs.type = SCALAR;
+ for (i = 0; VEC_iterate (ce_s, rhsc, i, rhsp); ++i)
+ process_constraint (new_constraint (lhs, *rhsp));
}
- newvi = new_var_info (decl, newindex, newname, newindex);
- newvi->offset = fo->offset;
- newvi->size = TREE_INT_CST_LOW (fo->size);
- newvi->fullsize = vi->fullsize;
- insert_into_field_list (vi, newvi);
- VEC_safe_push (varinfo_t, heap, varmap, newvi);
- if (is_global && (!flag_whole_program || !in_ipa_mode))
- make_constraint_to_anything (newvi);
-
- stats.total_vars++;
+ VEC_free (ce_s, heap, rhsc);
}
- VEC_free (fieldoff_s, heap, fieldstack);
}
- return index;
+
+ return id;
}
/* Print out the points-to solution for VAR to FILE. */
-void
+static void
dump_solution_for_var (FILE *file, unsigned int var)
{
varinfo_t vi = get_varinfo (var);
unsigned int i;
- bitmap_iterator bi;
-
+ bitmap_iterator bi;
+
+ /* Dump the solution for unified vars anyway, this avoids difficulties
+ in scanning dumps in the testsuite. */
fprintf (file, "%s = { ", vi->name);
- EXECUTE_IF_SET_IN_BITMAP (get_varinfo (vi->node)->solution, 0, i, bi)
- {
- fprintf (file, "%s ", get_varinfo (i)->name);
- }
- fprintf (file, "}\n");
+ 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. */
dump_solution_for_var (stdout, var);
}
-
/* Create varinfo structures for all of the variables in the
function for intraprocedural mode. */
{
tree t;
- /* For each incoming argument arg, ARG = &ANYTHING or a dummy variable if
- flag_argument_noalias > 2. */
+ /* 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 = TREE_CHAIN (t))
{
- struct constraint_expr lhs;
varinfo_t p;
-
- lhs.offset = 0;
- lhs.type = SCALAR;
- lhs.var = create_variable_info_for (t, alias_get_name (t));
-
- /* With flag_argument_noalias greater than two means that the incoming
- argument cannot alias anything except for itself so create a HEAP
- variable. */
- if (POINTER_TYPE_P (TREE_TYPE (t))
- && flag_argument_noalias > 2)
+
+ if (!could_have_pointers (t))
+ continue;
+
+ /* For restrict qualified pointers to objects passed by
+ reference build a real representative for the pointed-to object. */
+ if (DECL_BY_REFERENCE (t)
+ && POINTER_TYPE_P (TREE_TYPE (t))
+ && TYPE_RESTRICT (TREE_TYPE (t)))
{
+ struct constraint_expr lhsc, rhsc;
varinfo_t vi;
- struct constraint_expr rhs;
- tree heapvar = heapvar_lookup (t);
- unsigned int id;
+ tree heapvar = heapvar_lookup (t, 0);
if (heapvar == NULL_TREE)
{
- heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)),
+ var_ann_t ann;
+ heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)),
"PARM_NOALIAS");
DECL_EXTERNAL (heapvar) = 1;
- if (referenced_vars)
- add_referenced_var (heapvar);
- heapvar_insert (t, heapvar);
- }
- id = create_variable_info_for (heapvar,
- alias_get_name (heapvar));
- vi = get_varinfo (id);
- vi->is_artificial_var = 1;
- vi->is_heap_var = 1;
- rhs.var = id;
- rhs.type = ADDRESSOF;
- rhs.offset = 0;
- for (p = get_varinfo (lhs.var); p; p = p->next)
- {
- struct constraint_expr temp = lhs;
- temp.var = p->id;
- process_constraint (new_constraint (temp, rhs));
+ heapvar_insert (t, 0, heapvar);
+ ann = get_var_ann (heapvar);
+ ann->is_heapvar = 1;
}
+ if (gimple_referenced_vars (cfun))
+ add_referenced_var (heapvar);
+ lhsc.var = get_vi_for_tree (t)->id;
+ lhsc.type = SCALAR;
+ lhsc.offset = 0;
+ rhsc.var = (vi = get_vi_for_tree (heapvar))->id;
+ rhsc.type = ADDRESSOF;
+ rhsc.offset = 0;
+ process_constraint (new_constraint (lhsc, rhsc));
+ vi->is_restrict_var = 1;
+ continue;
}
- else
- for (p = get_varinfo (lhs.var); p; p = p->next)
- make_constraint_to_anything (p);
- }
+
+ for (p = get_vi_for_tree (t); p; p = p->next)
+ {
+ if (p->may_have_pointers)
+ make_constraint_from (p, nonlocal_id);
+ if (p->only_restrict_pointers)
+ make_constraint_from_restrict (p, "PARM_RESTRICT");
+ }
+ if (POINTER_TYPE_P (TREE_TYPE (t))
+ && TYPE_RESTRICT (TREE_TYPE (t)))
+ make_constraint_from_restrict (get_vi_for_tree (t), "PARM_RESTRICT");
+ }
+
+ /* 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 */
+
+/* Set bits in INTO corresponding to the variable uids in solution set FROM. */
static void
-set_uids_in_ptset (bitmap into, bitmap from)
+set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt)
{
unsigned int i;
bitmap_iterator bi;
- subvar_t sv;
EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
{
set are heap variables. */
if (vi->is_artificial_var && !vi->is_heap_var)
continue;
-
- if (vi->has_union && get_subvars_for_var (vi->decl) != NULL)
+
+ if (TREE_CODE (vi->decl) == VAR_DECL
+ || TREE_CODE (vi->decl) == PARM_DECL
+ || TREE_CODE (vi->decl) == RESULT_DECL)
{
- /* Variables containing unions may need to be converted to
- their SFT's, because SFT's can have unions and we cannot. */
- for (sv = get_subvars_for_var (vi->decl); sv; sv = sv->next)
- bitmap_set_bit (into, DECL_UID (sv->var));
+ /* 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;
}
- else if (TREE_CODE (vi->decl) == VAR_DECL
- || TREE_CODE (vi->decl) == PARM_DECL)
+ }
+}
+
+
+/* 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 (var_can_have_subvars (vi->decl)
- && get_subvars_for_var (vi->decl))
- {
- /* If VI->DECL is an aggregate for which we created
- SFTs, add the SFT corresponding to VI->OFFSET. */
- tree sft = get_subvar_at (vi->decl, vi->offset);
- if (sft)
- bitmap_set_bit (into, DECL_UID (sft));
- }
- else
+ if (vi->id == nothing_id)
+ pt->null = 1;
+ else if (vi->id == escaped_id)
{
- /* Otherwise, just add VI->DECL to the alias set. */
- bitmap_set_bit (into, DECL_UID (vi->decl));
+ 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;
}
+ if (vi->is_restrict_var)
+ pt->vars_contains_restrict = true;
}
-}
+ /* Instead of doing extra work, simply do not create
+ elaborate points-to information for pt_anything pointers. */
+ if (pt->anything
+ && (orig_vi->is_artificial_var
+ || !pt->vars_contains_restrict))
+ return;
+
+ /* Share the final set of variables when possible. */
+ finished_solution = BITMAP_GGC_ALLOC ();
+ stats.points_to_sets_created++;
-static bool have_alias_info = false;
+ 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, or return
- false if we can't. */
+/* Given a pointer variable P, fill in its points-to set. */
-bool
+static void
find_what_p_points_to (tree p)
{
- unsigned int id = 0;
+ struct ptr_info_def *pi;
tree lookup_p = p;
-
- if (!have_alias_info)
- return false;
+ 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
- && default_def (SSA_NAME_VAR (p)) == p)
+ if (TREE_CODE (p) == SSA_NAME
+ && TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL
+ && SSA_NAME_IS_DEFAULT_DEF (p))
lookup_p = SSA_NAME_VAR (p);
- if (lookup_id_for_tree (lookup_p, &id))
- {
- varinfo_t vi = get_varinfo (id);
-
- if (vi->is_artificial_var)
- return false;
+ vi = lookup_vi_for_tree (lookup_p);
+ if (!vi)
+ return;
- /* See if this is a field or a structure. */
- if (vi->size != vi->fullsize)
- {
- /* Nothing currently asks about structure fields directly,
- but when they do, we need code here to hand back the
- points-to set. */
- if (!var_can_have_subvars (vi->decl)
- || get_subvars_for_var (vi->decl) == NULL)
- return false;
- }
- else
- {
- struct ptr_info_def *pi = get_ptr_info (p);
- unsigned int i;
- bitmap_iterator bi;
+ pi = get_ptr_info (p);
+ find_what_var_points_to (vi, &pi->pt);
+}
- /* This variable may have been collapsed, let's get the real
- variable. */
- vi = get_varinfo (vi->node);
-
- /* 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)
- {
- /* FIXME. READONLY should be handled better so that
- flow insensitive aliasing can disregard writable
- aliases. */
- if (vi->id == nothing_id)
- pi->pt_null = 1;
- else if (vi->id == anything_id)
- pi->pt_anything = 1;
- else if (vi->id == readonly_id)
- pi->pt_anything = 1;
- else if (vi->id == integer_id)
- pi->pt_anything = 1;
- else if (vi->is_heap_var)
- pi->pt_global_mem = 1;
- }
- }
+/* 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);
+}
- if (pi->pt_anything)
- return false;
- if (!pi->pt_vars)
- pi->pt_vars = BITMAP_GGC_ALLOC ();
+/* Reset the points-to solution *PT to a conservative default
+ (point to anything). */
- set_uids_in_ptset (pi->pt_vars, vi->solution);
+void
+pt_solution_reset (struct pt_solution *pt)
+{
+ memset (pt, 0, sizeof (struct pt_solution));
+ pt->anything = true;
+}
- if (bitmap_empty_p (pi->pt_vars))
- pi->pt_vars = NULL;
+/* 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. */
- return true;
- }
+void
+pt_solution_set (struct pt_solution *pt, bitmap vars,
+ bool vars_contains_global, bool vars_contains_restrict)
+{
+ memset (pt, 0, sizeof (struct pt_solution));
+ pt->vars = vars;
+ pt->vars_contains_global = vars_contains_global;
+ pt->vars_contains_restrict = vars_contains_restrict;
+}
+
+/* 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;
+ dest->vars_contains_restrict |= src->vars_contains_restrict;
+ 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 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;
+}
+
+/* Return true if both points-to solutions PT1 and PT2 for two restrict
+ qualified pointers are possibly based on the same pointer. */
+
+bool
+pt_solutions_same_restrict_base (struct pt_solution *pt1,
+ struct pt_solution *pt2)
+{
+ /* If we deal with points-to solutions of two restrict qualified
+ pointers solely rely on the pointed-to variable bitmap intersection.
+ For two pointers that are based on each other the bitmaps will
+ intersect. */
+ if (pt1->vars_contains_restrict
+ && pt2->vars_contains_restrict)
+ {
+ gcc_assert (pt1->vars && pt2->vars);
+ return bitmap_intersect_p (pt1->vars, pt2->vars);
+ }
+
+ return true;
+}
/* Dump points-to information to OUTFILE. */
-void
+static void
dump_sa_points_to_info (FILE *outfile)
{
unsigned int i;
{
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, "Collapsed vars: %d\n", stats.collapsed_vars);
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++)
- dump_solution_for_var (outfile, i);
+ {
+ varinfo_t vi = get_varinfo (i);
+ if (!vi->may_have_pointers)
+ continue;
+ dump_solution_for_var (outfile, i);
+ }
}
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. */
- nothing_tree = create_tmp_var_raw (void_type_node, "NULL");
- var_nothing = new_var_info (nothing_tree, 0, "NULL", 0);
- insert_id_for_tree (nothing_tree, 0);
+ 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;
- nothing_id = 0;
- VEC_safe_push (varinfo_t, heap, varmap, var_nothing);
+ 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. */
- anything_tree = create_tmp_var_raw (void_type_node, "ANYTHING");
- var_anything = new_var_info (anything_tree, 1, "ANYTHING", 1);
- insert_id_for_tree (anything_tree, 1);
+ 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_id = 1;
/* Anything points to anything. This makes deref constraints just
- work in the presence of linked list and other p = *p type loops,
+ work in the presence of linked list and other p = *p type loops,
by saying that *ANYTHING = ANYTHING. */
- VEC_safe_push (varinfo_t, heap, varmap, var_anything);
lhs.type = SCALAR;
lhs.var = anything_id;
lhs.offset = 0;
rhs.type = ADDRESSOF;
rhs.var = anything_id;
rhs.offset = 0;
- var_anything->address_taken = true;
/* 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. */
- readonly_tree = create_tmp_var_raw (void_type_node, "READONLY");
- var_readonly = new_var_info (readonly_tree, 2, "READONLY", 2);
+ 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;
- insert_id_for_tree (readonly_tree, 2);
- readonly_id = 2;
- VEC_safe_push (varinfo_t, heap, varmap, var_readonly);
/* readonly memory points to anything, in order to make deref
easier. In reality, it points to anything the particular
lhs.var = readonly_id;
lhs.offset = 0;
rhs.type = ADDRESSOF;
- rhs.var = anything_id;
+ 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 an INTEGER. */
- integer_tree = create_tmp_var_raw (void_type_node, "INTEGER");
- var_integer = new_var_info (integer_tree, 3, "INTEGER", 3);
- insert_id_for_tree (integer_tree, 3);
+ 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_id = 3;
- VEC_safe_push (varinfo_t, heap, varmap, var_integer);
- /* *INTEGER = ANYTHING, because we don't know where a dereference of a random
- integer will point to. */
+ /* 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.var = anything_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
-}
-
-/* Return true if we actually need to solve the constraint graph in order to
- get our points-to sets. This is false when, for example, no addresses are
- taken other than special vars, or all points-to sets with members already
- contain the anything variable and there are no predecessors for other
- sets. */
-
-static bool
-need_to_solve (void)
-{
- int i;
- varinfo_t v;
- bool found_address_taken = false;
- bool found_non_anything = false;
-
- for (i = 0; VEC_iterate (varinfo_t, varmap, i, v); i++)
- {
- if (v->is_special_var)
- continue;
-
- if (v->address_taken)
- found_address_taken = true;
-
- if (v->solution
- && !bitmap_empty_p (v->solution)
- && !bitmap_bit_p (v->solution, anything_id))
- found_non_anything = true;
- else if (bitmap_empty_p (v->solution)
- && (VEC_length (constraint_edge_t, graph->preds[v->id]) != 0
- || (graph->zero_weight_preds[v->id] && !bitmap_empty_p (graph->zero_weight_preds[v->id]))))
- found_non_anything = true;
-
- if (found_address_taken && found_non_anything)
- return true;
- }
-
- return false;
}
/* Initialize things necessary to perform PTA */
static void
init_alias_vars (void)
{
- bitmap_obstack_initialize (&ptabitmap_obstack);
+ 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",
+ 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);
- constraint_edge_pool = create_alloc_pool ("Constraint edges",
- sizeof (struct constraint_edge), 30);
-
constraints = VEC_alloc (constraint_t, heap, 8);
varmap = VEC_alloc (varinfo_t, heap, 8);
- id_for_tree = htab_create (10, tree_id_hash, tree_id_eq, free);
- memset (&stats, 0, sizeof (stats));
+ 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 ();
}
+/* 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);
+}
+
+/* Initialize the heapvar for statement mapping. */
+
+static void
+init_alias_heapvars (void)
+{
+ if (!heapvar_for_stmt)
+ heapvar_for_stmt = htab_create_ggc (11, tree_map_hash, heapvar_map_eq,
+ NULL);
+}
+
+/* Delete the heapvar for statement mapping. */
+
+void
+delete_alias_heapvars (void)
+{
+ if (heapvar_for_stmt)
+ htab_delete (heapvar_for_stmt);
+ heapvar_for_stmt = NULL;
+}
+
+/* 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);
+
+ if (dump_file && (dump_flags & TDF_GRAPH))
+ dump_constraint_graph (dump_file);
+
+ 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)
+ fprintf (dump_file, "Solving graph\n");
+
+ solve_graph (graph);
+
+ 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. */
-void
-compute_points_to_sets (struct alias_info *ai)
+static void
+compute_points_to_sets (void)
{
basic_block bb;
+ unsigned i;
+ varinfo_t vi;
timevar_push (TV_TREE_PTA);
init_alias_vars ();
+ init_alias_heapvars ();
intra_create_variable_infos ();
- /* Now walk all statements and derive aliases. */
+ /* Now walk all statements and build the constraint set. */
FOR_EACH_BB (bb)
{
- block_stmt_iterator bsi;
- tree phi;
+ gimple_stmt_iterator gsi;
- for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- if (is_gimple_reg (PHI_RESULT (phi)))
- {
- find_func_aliases (phi);
- /* Update various related attributes like escaped
- addresses, pointer dereferences for loads and stores.
- This is used when creating name tags and alias
- sets. */
- update_alias_info (phi, ai);
- }
+ gimple phi = gsi_stmt (gsi);
+
+ if (is_gimple_reg (gimple_phi_result (phi)))
+ find_func_aliases (phi);
}
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- tree stmt = bsi_stmt (bsi);
+ gimple stmt = gsi_stmt (gsi);
+
find_func_aliases (stmt);
- /* Update various related attributes like escaped
- addresses, pointer dereferences for loads and stores.
- This is used when creating name tags and alias
- sets. */
- update_alias_info (stmt, ai);
}
}
- build_constraint_graph ();
-
if (dump_file)
{
fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
- dump_constraints (dump_file);
+ dump_constraints (dump_file, 0);
}
-
- if (1 || need_to_solve ())
+
+ /* 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 (i = 0; VEC_iterate (varinfo_t, varmap, i, vi); ++i)
+ if (vi->is_heap_var
+ && !vi->is_restrict_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)
{
- if (dump_file)
- fprintf (dump_file,
- "\nCollapsing static cycles and doing variable "
- "substitution:\n");
-
- find_and_collapse_graph_cycles (graph, false);
- perform_var_substitution (graph);
-
- if (dump_file)
- fprintf (dump_file, "\nSolving graph:\n");
-
- solve_graph (graph);
+ 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;
+ }
+ }
}
-
- if (dump_file)
- dump_sa_points_to_info (dump_file);
-
- have_alias_info = true;
timevar_pop (TV_TREE_PTA);
}
/* Delete created points-to sets. */
-void
+static void
delete_points_to_sets (void)
{
- varinfo_t v;
- int i;
+ unsigned int i;
- htab_delete (id_for_tree);
- bitmap_obstack_release (&ptabitmap_obstack);
- bitmap_obstack_release (&predbitmap_obstack);
+ 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; VEC_iterate (varinfo_t, varmap, i, v); i++)
- {
- VEC_free (constraint_edge_t, heap, graph->succs[i]);
- VEC_free (constraint_edge_t, heap, graph->preds[i]);
- VEC_free (constraint_t, heap, v->complex);
- }
- free (graph->zero_weight_preds);
- free (graph->zero_weight_succs);
+
+ 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->preds);
+ 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);
- free_alloc_pool (constraint_edge_pool);
+ free_alloc_pool (constraint_pool);
+}
+
+
+/* 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;
+}
- have_alias_info = false;
+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_dump_func /* 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_dump_func /* todo_flags_finish */
+ }
+};
+
+
/* Return true if we should execute IPA PTA. */
static bool
gate_ipa_pta (void)
{
- return (flag_unit_at_a_time != 0
- && flag_ipa_pta
+ return (optimize
+ && flag_ipa_pta
/* Don't bother doing anything if the program has errors. */
&& !(errorcount || sorrycount));
}
+/* IPA PTA solutions for ESCAPED. */
+struct pt_solution ipa_escaped_pt
+ = { true, false, false, false, false, false, false, NULL };
+
/* 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_heapvars ();
init_alias_vars ();
-
+
+ /* Build the constraints. */
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ /* 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 (!gimple_has_body_p (node->decl)
+ || node->clone_of)
+ continue;
+
+ create_function_info_for (node->decl,
+ cgraph_node_name (node));
+ }
+
+ /* Create constraints for global variables and their initializers. */
+ for (var = varpool_nodes; var; var = var->next)
+ 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)
{
- if (!node->analyzed || cgraph_is_master_clone (node))
+ struct function *func;
+ basic_block bb;
+ tree old_func_decl;
+
+ /* Nodes without a body are not interesting. */
+ if (!gimple_has_body_p (node->decl)
+ || node->clone_of)
+ continue;
+
+ if (dump_file)
+ fprintf (dump_file,
+ "Generating constraints for %s\n",
+ cgraph_node_name (node));
+
+ func = DECL_STRUCT_FUNCTION (node->decl);
+ old_func_decl = current_function_decl;
+ push_cfun (func);
+ current_function_decl = node->decl;
+
+ /* For externally visible 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->local.externally_visible)
+ intra_create_variable_infos ();
+
+ /* Build constriants for the function body. */
+ FOR_EACH_BB_FN (bb, func)
{
- unsigned int varid;
-
- varid = create_function_info_for (node->decl,
- cgraph_node_name (node));
- if (node->local.externally_visible)
+ 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))
{
- varinfo_t fi = get_varinfo (varid);
- for (; fi; fi = fi->next)
- make_constraint_to_anything (fi);
+ 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)
{
- if (node->analyzed && cgraph_is_master_clone (node))
+ 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 (!gimple_has_body_p (node->decl)
+ || node->clone_of)
+ continue;
+
+ fn = DECL_STRUCT_FUNCTION (node->decl);
+
+ /* Compute the points-to sets for pointer SSA_NAMEs. */
+ for (i = 0; VEC_iterate (tree, fn->gimple_df->ssa_names, i, ptr); ++i)
+ {
+ 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)
{
- struct function *cfun = DECL_STRUCT_FUNCTION (node->decl);
- basic_block bb;
- tree old_func_decl = current_function_decl;
- if (dump_file)
- fprintf (dump_file,
- "Generating constraints for %s\n",
- cgraph_node_name (node));
- push_cfun (cfun);
- current_function_decl = node->decl;
-
- FOR_EACH_BB_FN (bb, cfun)
+ 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))
{
- block_stmt_iterator bsi;
- tree phi;
-
- for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
+ 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))
{
- if (is_gimple_reg (PHI_RESULT (phi)))
+ 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
{
- find_func_aliases (phi);
+ /* 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;
}
}
-
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+
+ /* Handle indirect calls. */
+ if (!decl
+ && (fi = get_fi_for_callee (stmt)))
{
- tree stmt = bsi_stmt (bsi);
- find_func_aliases (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);
+ }
+ }
+ }
}
- }
- current_function_decl = old_func_decl;
- pop_cfun ();
- }
- else
- {
- /* Make point to anything. */
+ }
}
+
+ fn->gimple_df->ipa_pta = true;
}
- build_constraint_graph ();
+ delete_points_to_sets ();
- if (dump_file)
- {
- fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
- dump_constraints (dump_file);
- }
-
- if (need_to_solve ())
- {
- if (dump_file)
- fprintf (dump_file,
- "\nCollapsing static cycles and doing variable "
- "substitution:\n");
-
- find_and_collapse_graph_cycles (graph, false);
- perform_var_substitution (graph);
-
- if (dump_file)
- fprintf (dump_file, "\nSolving graph:\n");
-
- solve_graph (graph);
- }
-
- if (dump_file)
- dump_sa_points_to_info (dump_file);
in_ipa_mode = 0;
- delete_alias_heapvars ();
- delete_points_to_sets ();
+
return 0;
}
-
-struct tree_opt_pass pass_ipa_pta =
+
+struct simple_ipa_opt_pass pass_ipa_pta =
{
+ {
+ SIMPLE_IPA_PASS,
"pta", /* name */
gate_ipa_pta, /* gate */
ipa_pta_execute, /* execute */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
+ TODO_update_ssa /* todo_flags_finish */
+ }
};
-/* Initialize the heapvar for statement mapping. */
-void
-init_alias_heapvars (void)
-{
- heapvar_for_stmt = htab_create_ggc (11, tree_map_hash, tree_map_eq, NULL);
-}
-
-void
-delete_alias_heapvars (void)
-{
- htab_delete (heapvar_for_stmt);
-}
-
#include "gt-tree-ssa-structalias.h"
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