/* Tree based points-to analysis
- Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007 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 "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
http://citeseer.ist.psu.edu/heintze01ultrafast.html
There are three types of real constraint expressions, DEREF,
- ADDRESSOF, and SCALAR. There is one type of fake constraint
- expression, called INCLUDES. Each constraint expression consists
+ 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.
ADDRESSOF is a constraint expression used to represent &x, whether
it appears on the LHS or the RHS of a statement.
- INCLUDES is a constraint expression type used to represent just a
- setting of a bit in the points-to set without having the address
- taken. It exists mainly for abstraction sake, and is used for
- initializing fake variables like the ESCAPED_VARS set.
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.
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);
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;
-
- /* Tree that this variable is associated with. */
- tree decl;
-
- /* 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;
-
- /* Full size of the base variable, in bits. */
- unsigned HOST_WIDE_INT fullsize;
-
- /* A link to the variable for the next field in this structure. */
- struct variable_info *next;
-
- /* Node in the graph that represents the constraints and points-to
- solution for the variable. */
- unsigned int node;
-
- /* True if the address of this variable is taken. Needed for
- variable substitution. */
- unsigned int address_taken:1;
-
- /* True if this variable is the target of a dereference. Needed for
- variable substitution. */
- unsigned int indirect_target:1;
-
- /* True if the variable is directly the target of a dereference.
- This is used to track which variables are *actually* dereferenced
- so we can prune their points to listed. This is equivalent to the
- indirect_target flag when no merging of variables happens. */
- unsigned int directly_dereferenced: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 for variables whose size is not known or variable. */
unsigned int is_unknown_size_var:1;
- /* True for variables that have unions somewhere in them. */
- unsigned int has_union:1;
+ /* True for (sub-)fields that represent a whole variable. */
+ unsigned int is_full_var : 1;
/* True if this is a heap variable. */
unsigned int is_heap_var:1;
- /* Points-to set for this variable. */
- bitmap solution;
+ /* True if we may not use TBAA to prune references to this
+ variable. This is used for C++ placement new. */
+ unsigned int no_tbaa_pruning : 1;
+
+ /* Variable id this was collapsed to due to type unsafety. Zero if
+ this variable was not collapsed. This should be unused completely
+ after build_succ_graph, or something is broken. */
+ unsigned int collapsed_to;
+
+ /* 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;
- /* Finished points-to set for this variable (IE what is returned
- from find_what_p_points_to. */
- bitmap finished_solution;
+ /* Full size of the base variable, in bits. */
+ unsigned HOST_WIDE_INT fullsize;
+
+ /* Name of this variable */
+ const char *name;
- /* Variable ids represented by this node. */
- bitmap variables;
+ /* Tree that this variable is associated with. */
+ tree decl;
- /* Vector of complex constraints for this node. Complex
- constraints are those involving dereferences. */
- VEC(constraint_t,heap) *complex;
+ /* Points-to set for this variable. */
+ bitmap solution;
- /* 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 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 inline varinfo_t
get_varinfo_fc (unsigned int n)
{
- varinfo_t v = VEC_index(varinfo_t, varmap, n);
+ varinfo_t v = VEC_index (varinfo_t, varmap, n);
- if (v->collapsed_to)
- return v->collapsed_to;
+ if (v->collapsed_to != 0)
+ return get_varinfo (v->collapsed_to);
return v;
}
+/* Static IDs for the special variables. */
+enum { nothing_id = 0, anything_id = 1, readonly_id = 2,
+ escaped_id = 3, nonlocal_id = 4, callused_id = 5, integer_id = 6 };
+
/* 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 escaped memory. */
+static varinfo_t var_escaped;
+static tree escaped_tree;
+
+/* Variable that represents nonlocal memory. */
+static varinfo_t var_nonlocal;
+static tree nonlocal_tree;
+
+/* Variable that represents call-used memory. */
+static varinfo_t var_callused;
+static tree callused_tree;
/* 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;
/* Lookup a heap var for FROM, and return it if we find one. */
heapvar_lookup (tree from)
{
struct tree_map *h, in;
- in.from = from;
+ in.base.from = from;
- h = htab_find_with_hash (heapvar_for_stmt, &in, htab_hash_pointer (from));
+ h = (struct tree_map *) htab_find_with_hash (heapvar_for_stmt, &in,
+ htab_hash_pointer (from));
if (h)
return h->to;
return NULL_TREE;
struct tree_map *h;
void **loc;
- h = ggc_alloc (sizeof (struct tree_map));
+ h = GGC_NEW (struct tree_map);
h->hash = htab_hash_pointer (from);
- h->from = from;
+ h->base.from = from;
h->to = to;
loc = htab_find_slot_with_hash (heapvar_for_stmt, h, h->hash, INSERT);
*(struct tree_map **) loc = h;
named NAME, and using constraint graph node NODE. */
static varinfo_t
-new_var_info (tree t, unsigned int id, const char *name, unsigned int node)
+new_var_info (tree t, unsigned int id, const char *name)
{
- varinfo_t ret = pool_alloc (variable_info_pool);
+ varinfo_t ret = (varinfo_t) pool_alloc (variable_info_pool);
+ tree var;
ret->id = id;
ret->name = name;
ret->decl = t;
- ret->node = node;
- ret->address_taken = false;
- ret->indirect_target = false;
- ret->directly_dereferenced = false;
ret->is_artificial_var = false;
ret->is_heap_var = false;
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->finished_solution = NULL;
- ret->complex = NULL;
+ ret->is_full_var = false;
+ var = t;
+ if (TREE_CODE (var) == SSA_NAME)
+ var = SSA_NAME_VAR (var);
+ ret->no_tbaa_pruning = (DECL_P (var)
+ && POINTER_TYPE_P (TREE_TYPE (var))
+ && DECL_NO_TBAA_P (var));
+ ret->solution = BITMAP_ALLOC (&pta_obstack);
+ ret->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
ret->next = NULL;
- ret->collapsed_to = NULL;
+ ret->collapsed_to = 0;
return ret;
}
-typedef enum {SCALAR, DEREF, ADDRESSOF, INCLUDES} constraint_expr_type;
+typedef enum {SCALAR, DEREF, ADDRESSOF} constraint_expr_type;
/* An expression that appears in a constraint. */
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) **);
static alloc_pool constraint_pool;
+DEF_VEC_I(int);
+DEF_VEC_ALLOC_I(int, heap);
+
/* The constraint graph is represented as an array of bitmaps
containing successor nodes. */
struct constraint_graph
{
+ /* Size of this graph, which may be different than the number of
+ nodes in the variable map. */
+ unsigned int size;
+
+ /* Explicit successors of each node. */
bitmap *succs;
+
+ /* Implicit predecessors of each node (Used for variable
+ substitution). */
+ bitmap *implicit_preds;
+
+ /* Explicit predecessors of each node (Used for variable substitution). */
bitmap *preds;
-};
-typedef struct constraint_graph *constraint_graph_t;
+ /* Indirect cycle representatives, or -1 if the node has no indirect
+ cycles. */
+ int *indirect_cycles;
+
+ /* Representative node for a node. rep[a] == a unless the node has
+ been unified. */
+ unsigned int *rep;
+
+ /* Equivalence class representative for a label. This is used for
+ variable substitution. */
+ int *eq_rep;
+
+ /* Pointer equivalence label for a node. All nodes with the same
+ pointer equivalence label can be unified together at some point
+ (either during constraint optimization or after the constraint
+ graph is built). */
+ unsigned int *pe;
+
+ /* Pointer equivalence representative for a label. This is used to
+ handle nodes that are pointer equivalent but not location
+ equivalent. We can unite these once the addressof constraints
+ are transformed into initial points-to sets. */
+ int *pe_rep;
+
+ /* Pointer equivalence label for each node, used during variable
+ substitution. */
+ unsigned int *pointer_label;
+
+ /* Location equivalence label for each node, used during location
+ equivalence finding. */
+ unsigned int *loc_label;
+
+ /* Pointed-by set for each node, used during location equivalence
+ finding. This is pointed-by rather than pointed-to, because it
+ is constructed using the predecessor graph. */
+ bitmap *pointed_by;
+
+ /* Points to sets for pointer equivalence. This is *not* the actual
+ points-to sets for nodes. */
+ bitmap *points_to;
+
+ /* Bitmap of nodes where the bit is set if the node is a direct
+ node. Used for variable substitution. */
+ sbitmap direct_nodes;
+
+ /* Bitmap of nodes where the bit is set if the node is address
+ taken. Used for variable substitution. */
+ bitmap address_taken;
+
+ /* Vector of complex constraints for each graph node. Complex
+ constraints are those involving dereferences or offsets that are
+ not 0. */
+ VEC(constraint_t,heap) **complex;
+};
static constraint_graph_t graph;
+/* During variable substitution and the offline version of indirect
+ cycle finding, we create nodes to represent dereferences and
+ address taken constraints. These represent where these start and
+ end. */
+#define FIRST_REF_NODE (VEC_length (varinfo_t, varmap))
+#define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
+
+/* Return the representative node for NODE, if NODE has been unioned
+ with another NODE.
+ This function performs path compression along the way to finding
+ the representative. */
+
+static unsigned int
+find (unsigned int node)
+{
+ gcc_assert (node < graph->size);
+ if (graph->rep[node] != node)
+ return graph->rep[node] = find (graph->rep[node]);
+ return node;
+}
+
+/* Union the TO and FROM nodes to the TO nodes.
+ Note that at some point in the future, we may want to do
+ union-by-rank, in which case we are going to have to return the
+ node we unified to. */
+
+static bool
+unite (unsigned int to, unsigned int from)
+{
+ gcc_assert (to < graph->size && from < graph->size);
+ if (to != from && graph->rep[from] != to)
+ {
+ graph->rep[from] = to;
+ return true;
+ }
+ return false;
+}
+
/* Create a new constraint consisting of LHS and RHS expressions. */
static constraint_t
new_constraint (const struct constraint_expr lhs,
const struct constraint_expr rhs)
{
- constraint_t ret = pool_alloc (constraint_pool);
+ constraint_t ret = (constraint_t) pool_alloc (constraint_pool);
ret->lhs = lhs;
ret->rhs = rhs;
return ret;
fprintf (file, "&");
else if (c->rhs.type == DEREF)
fprintf (file, "*");
- else if (c->rhs.type == INCLUDES)
- fprintf (file, "{");
fprintf (file, "%s", get_varinfo_fc (c->rhs.var)->name);
if (c->rhs.offset != 0)
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->rhs.offset);
- if (c->rhs.type == INCLUDES)
- fprintf (file, "}");
fprintf (file, "\n");
}
dump_constraints (stderr);
}
+/* 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. */
+
+void
+dump_constraint_edge (FILE *file, constraint_t c)
+{
+ if (c->rhs.type != ADDRESSOF)
+ {
+ const char *src = get_varinfo_fc (c->rhs.var)->name;
+ const char *dst = get_varinfo_fc (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. */
+
+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);
+ 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_fc (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
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)
{
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. */
+ varinfo_t vi = get_varinfo (i);
- if ((get_varinfo (i)->offset + offset) < get_varinfo (i)->fullsize)
+ /* If this is a variable with just one field just set its bit
+ in the result. */
+ if (vi->is_artificial_var
+ || vi->is_unknown_size_var
+ || vi->is_full_var)
+ bitmap_set_bit (result, i);
+ else
{
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (i)->offset + offset;
- varinfo_t v = first_vi_for_offset (get_varinfo (i), fieldoffset);
+ unsigned HOST_WIDE_INT fieldoffset = vi->offset + offset;
+ varinfo_t v = first_vi_for_offset (vi, fieldoffset);
+ /* If the result is outside of the variable use the last field. */
if (!v)
- continue;
+ {
+ v = vi;
+ while (v->next != NULL)
+ v = v->next;
+ }
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)
- {
- bitmap_set_bit (result, i);
+ /* If the result is not exactly at fieldoffset include the next
+ field as well. See get_constraint_for_ptr_offset for more
+ rationale. */
+ if (v->offset != fieldoffset
+ && v->next != NULL)
+ bitmap_set_bit (result, v->next->id);
}
}
}
}
-/* 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);
+
+ /* 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);
}
all associated info from SRC to TO. */
static void
-condense_varmap_nodes (unsigned int to, unsigned int src)
+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;
}
static void
clear_edges_for_node (constraint_graph_t graph, unsigned int node)
{
- bitmap_iterator bi;
- unsigned int j;
-
- /* Walk the successors, erase the associated preds. */
-
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[node], 0, j, bi)
- if (j != node)
- bitmap_clear_bit (graph->preds[j], node);
-
-
- /* Walk the preds, erase the associated succs. */
-
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[node], 0, j, bi)
- if (j != node)
- bitmap_clear_bit (graph->succs[j], node);
-
-
- if (graph->preds[node])
- {
- BITMAP_FREE (graph->preds[node]);
- graph->preds[node] = NULL;
- }
-
if (graph->succs[node])
- {
- BITMAP_FREE (graph->succs[node]);
- graph->succs[node] = NULL;
- }
+ BITMAP_FREE (graph->succs[node]);
}
-static bool edge_added = false;
-
/* Merge GRAPH nodes FROM and TO into node TO. */
static void
merge_graph_nodes (constraint_graph_t graph, unsigned int to,
unsigned int from)
{
- unsigned int j;
- bitmap_iterator bi;
-
- /* Merge all the predecessor edges. */
- if (graph->preds[from])
+ if (graph->indirect_cycles[from] != -1)
{
- if (!graph->preds[to])
- graph->preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
-
- EXECUTE_IF_SET_IN_BITMAP (graph->preds[from], 0, j, bi)
- {
- if (j != to)
- {
- bitmap_clear_bit (graph->succs[j], from);
- bitmap_set_bit (graph->succs[j], to);
- }
- }
- bitmap_ior_into (graph->preds[to],
- graph->preds[from]);
+ /* If we have indirect cycles with the from node, and we have
+ none on the to node, the to node has indirect cycles from the
+ from node now that they are unified.
+ If indirect cycles exist on both, unify the nodes that they
+ are in a cycle with, since we know they are in a cycle with
+ each other. */
+ if (graph->indirect_cycles[to] == -1)
+ graph->indirect_cycles[to] = graph->indirect_cycles[from];
}
/* Merge all the successor edges. */
if (graph->succs[from])
{
if (!graph->succs[to])
- graph->succs[to] = BITMAP_ALLOC (&ptabitmap_obstack);
- EXECUTE_IF_SET_IN_BITMAP (graph->succs[from], 0, j, bi)
- {
- bitmap_clear_bit (graph->preds[j], from);
- bitmap_set_bit (graph->preds[j], to);
- }
+ graph->succs[to] = BITMAP_ALLOC (&pta_obstack);
bitmap_ior_into (graph->succs[to],
graph->succs[from]);
}
clear_edges_for_node (graph, from);
}
-/* Add a graph edge to GRAPH, going from TO to FROM if
+
+/* Add an indirect graph edge to GRAPH, going from TO to FROM if
+ it doesn't exist in the graph already. */
+
+static void
+add_implicit_graph_edge (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
+{
+ if (to == from)
+ return;
+
+ if (!graph->implicit_preds[to])
+ graph->implicit_preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
+
+ if (bitmap_set_bit (graph->implicit_preds[to], from))
+ stats.num_implicit_edges++;
+}
+
+/* Add a predecessor graph edge to GRAPH, going from TO to FROM if
+ it doesn't exist in the graph already.
+ Return false if the edge already existed, true otherwise. */
+
+static void
+add_pred_graph_edge (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
+{
+ if (!graph->preds[to])
+ graph->preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
+ bitmap_set_bit (graph->preds[to], from);
+}
+
+/* Add a graph edge to GRAPH, going from FROM to TO if
it doesn't exist in the graph already.
Return false if the edge already existed, true otherwise. */
{
bool r = false;
- if (!graph->preds[to])
- graph->preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
if (!graph->succs[from])
- graph->succs[from] = BITMAP_ALLOC (&ptabitmap_obstack);
- if (!bitmap_bit_p (graph->succs[from], to))
+ graph->succs[from] = BITMAP_ALLOC (&pta_obstack);
+ if (bitmap_set_bit (graph->succs[from], to))
{
- edge_added = true;
r = true;
- stats.num_edges++;
- bitmap_set_bit (graph->preds[to], from);
- bitmap_set_bit (graph->succs[from], to);
+ if (to < FIRST_REF_NODE && from < FIRST_REF_NODE)
+ stats.num_edges++;
}
return r;
}
&& bitmap_bit_p (graph->succs[dest], src));
}
-/* Build the constraint graph. */
+/* Initialize the constraint graph structure to contain SIZE nodes. */
+
+static void
+init_graph (unsigned int size)
+{
+ unsigned int j;
+
+ graph = XCNEW (struct constraint_graph);
+ graph->size = size;
+ graph->succs = XCNEWVEC (bitmap, graph->size);
+ graph->indirect_cycles = XNEWVEC (int, graph->size);
+ graph->rep = XNEWVEC (unsigned int, graph->size);
+ graph->complex = XCNEWVEC (VEC(constraint_t, heap) *, size);
+ graph->pe = XCNEWVEC (unsigned int, graph->size);
+ graph->pe_rep = XNEWVEC (int, graph->size);
+
+ for (j = 0; j < graph->size; j++)
+ {
+ graph->rep[j] = j;
+ graph->pe_rep[j] = -1;
+ graph->indirect_cycles[j] = -1;
+ }
+}
+
+/* Build the constraint graph, adding only predecessor edges right now. */
static void
-build_constraint_graph (void)
+build_pred_graph (void)
{
- int i = 0;
+ int i;
constraint_t c;
- int graph_size;
+ unsigned int j;
+
+ graph->implicit_preds = XCNEWVEC (bitmap, graph->size);
+ graph->preds = XCNEWVEC (bitmap, graph->size);
+ graph->pointer_label = XCNEWVEC (unsigned int, graph->size);
+ graph->loc_label = XCNEWVEC (unsigned int, graph->size);
+ graph->pointed_by = XCNEWVEC (bitmap, graph->size);
+ graph->points_to = XCNEWVEC (bitmap, graph->size);
+ graph->eq_rep = XNEWVEC (int, graph->size);
+ graph->direct_nodes = sbitmap_alloc (graph->size);
+ graph->address_taken = BITMAP_ALLOC (&predbitmap_obstack);
+ sbitmap_zero (graph->direct_nodes);
+
+ for (j = 0; j < FIRST_REF_NODE; j++)
+ {
+ if (!get_varinfo (j)->is_special_var)
+ SET_BIT (graph->direct_nodes, j);
+ }
- graph = XNEW (struct constraint_graph);
- graph_size = VEC_length (varinfo_t, varmap) + 1;
- graph->succs = XCNEWVEC (bitmap, graph_size);
- graph->preds = XCNEWVEC (bitmap, graph_size);
+ for (j = 0; j < graph->size; j++)
+ graph->eq_rep[j] = -1;
+
+ for (j = 0; j < VEC_length (varinfo_t, varmap); j++)
+ graph->indirect_cycles[j] = -1;
for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
{
if (lhs.type == DEREF)
{
- /* *x = y or *x = &y (complex) */
- if (rhs.type == ADDRESSOF || rhsvar > anything_id)
- insert_into_complex (lhsvar, c);
+ /* *x = y. */
+ if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
+ add_pred_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
}
else if (rhs.type == DEREF)
{
- /* !special var= *y */
- if (!(get_varinfo (lhsvar)->is_special_var))
- insert_into_complex (rhsvar, c);
+ /* x = *y */
+ if (rhs.offset == 0 && lhs.offset == 0 && lhs.type == SCALAR)
+ add_pred_graph_edge (graph, lhsvar, FIRST_REF_NODE + rhsvar);
+ else
+ RESET_BIT (graph->direct_nodes, lhsvar);
}
- else if (rhs.type == ADDRESSOF || rhs.type == INCLUDES)
+ else if (rhs.type == ADDRESSOF)
{
/* x = &y */
- bitmap_set_bit (get_varinfo (lhsvar)->solution, rhsvar);
+ 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);
+
+ RESET_BIT (graph->direct_nodes, rhsvar);
+ bitmap_set_bit (graph->address_taken, rhsvar);
}
- else if (lhsvar > anything_id)
+ else if (lhsvar > anything_id
+ && lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
{
- /* Ignore self edges, as they can't possibly contribute
- anything */
- if (lhsvar != rhsvar || rhs.offset != 0 || lhs.offset != 0)
- {
- if (rhs.offset != 0 || lhs.offset != 0)
- insert_into_complex (lhsvar, c);
- else
- add_graph_edge (graph, lhs.var, rhs.var);
- }
+ /* x = y */
+ add_pred_graph_edge (graph, lhsvar, rhsvar);
+ /* Implicitly, *x = *y */
+ add_implicit_graph_edge (graph, FIRST_REF_NODE + lhsvar,
+ FIRST_REF_NODE + rhsvar);
+ }
+ else if (lhs.offset != 0 || rhs.offset != 0)
+ {
+ if (rhs.offset != 0)
+ RESET_BIT (graph->direct_nodes, lhs.var);
+ else if (lhs.offset != 0)
+ RESET_BIT (graph->direct_nodes, rhs.var);
+ }
+ }
+}
+
+/* Build the constraint graph, adding successor edges. */
+
+static void
+build_succ_graph (void)
+{
+ int i;
+ constraint_t c;
+
+ for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
+ {
+ 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 (get_varinfo_fc (lhs.var)->id);
+ rhsvar = find (get_varinfo_fc (rhs.var)->id);
+ if (lhs.type == DEREF)
+ {
+ if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
+ add_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
+ }
+ else if (rhs.type == DEREF)
+ {
+ if (rhs.offset == 0 && lhs.offset == 0 && lhs.type == SCALAR)
+ add_graph_edge (graph, lhsvar, FIRST_REF_NODE + rhsvar);
+ }
+ else if (rhs.type == ADDRESSOF)
+ {
+ /* x = &y */
+ gcc_assert (find (get_varinfo_fc (rhs.var)->id)
+ == get_varinfo_fc (rhs.var)->id);
+ bitmap_set_bit (get_varinfo (lhsvar)->solution, rhsvar);
+ }
+ else if (lhsvar > anything_id
+ && lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
+ {
+ add_graph_edge (graph, lhsvar, rhsvar);
}
}
}
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;
};
{
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->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);
+ bitmap scc = BITMAP_ALLOC (NULL);
+ bool have_ref_node = n >= FIRST_REF_NODE;
+ unsigned int lowest_node;
+ bitmap_iterator bi;
+
+ bitmap_set_bit (scc, n);
+
+ while (VEC_length (unsigned, si->scc_stack) != 0
+ && si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
+ {
+ unsigned int w = VEC_pop (unsigned, si->scc_stack);
+
+ bitmap_set_bit (scc, w);
+ if (w >= FIRST_REF_NODE)
+ have_ref_node = true;
+ }
+
+ lowest_node = bitmap_first_set_bit (scc);
+ gcc_assert (lowest_node < FIRST_REF_NODE);
+
+ /* Collapse the SCC nodes into a single node, and mark the
+ indirect cycles. */
+ EXECUTE_IF_SET_IN_BITMAP (scc, 0, i, bi)
+ {
+ if (i < FIRST_REF_NODE)
+ {
+ if (unite (lowest_node, i))
+ unify_nodes (graph, lowest_node, i, false);
+ }
+ else
+ {
+ unite (lowest_node, i);
+ graph->indirect_cycles[i - FIRST_REF_NODE] = lowest_node;
+ }
+ }
}
+ SET_BIT (si->deleted, n);
}
else
VEC_safe_push (unsigned, heap, si->scc_stack, n);
}
-
-/* Collapse two variables into one variable, merging solutions if
- requested. */
+/* Unify node FROM into node TO, updating the changed count if
+ necessary when UPDATE_CHANGED is true. */
static void
-collapse_nodes (constraint_graph_t graph, unsigned int to, unsigned int from,
- bool merge_solutions)
+unify_nodes (constraint_graph_t graph, unsigned int to, unsigned int from,
+ bool update_changed)
{
- bitmap tosol, fromsol;
+
+ gcc_assert (to != from && find (to) == to);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Unifying %s to %s\n",
+ get_varinfo (from)->name,
+ get_varinfo (to)->name);
+
+ if (update_changed)
+ stats.unified_vars_dynamic++;
+ else
+ stats.unified_vars_static++;
merge_graph_nodes (graph, to, from);
- condense_varmap_nodes (to, from);
- if (merge_solutions)
- {
- tosol = get_varinfo (to)->solution;
- fromsol = get_varinfo (from)->solution;
- bitmap_ior_into (tosol, fromsol);
- BITMAP_FREE (fromsol);
- }
+ merge_node_constraints (graph, to, from);
- if (valid_graph_edge (graph, to, to))
+ if (get_varinfo (from)->no_tbaa_pruning)
+ get_varinfo (to)->no_tbaa_pruning = true;
+
+ /* Mark TO as changed if FROM was changed. If TO was already marked
+ as changed, decrease the changed count. */
+
+ if (update_changed && TEST_BIT (changed, from))
{
- if (graph->preds[to])
+ RESET_BIT (changed, from);
+ if (!TEST_BIT (changed, to))
+ SET_BIT (changed, to);
+ else
{
- bitmap_clear_bit (graph->preds[to], to);
- bitmap_clear_bit (graph->succs[to], to);
+ gcc_assert (changed_count > 0);
+ changed_count--;
}
}
-}
-
-
-/* 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. */
-
-static void
-process_unification_queue (constraint_graph_t graph, struct scc_info *si,
- 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
-
- 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
-
- merge complex constraints from tounify into rep
-
- update changed count to note that tounify will never change
- again
-
- Merge tmp into solution for rep, marking rep changed if this
- changed rep's solution.
-
- Delete any self-edges we now have for rep. */
- while (i != VEC_length (unsigned, si->unification_queue))
+ if (get_varinfo (from)->solution)
{
- 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++;
- else
- stats.unified_vars_static++;
- bitmap_ior_into (tmp, get_varinfo (tounify)->solution);
- collapse_nodes (graph, n, tounify, false);
-
- if (update_changed && TEST_BIT (changed, tounify))
+ /* 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))
{
- RESET_BIT (changed, tounify);
- if (!TEST_BIT (changed, n))
- SET_BIT (changed, n);
- else
+ 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;
-
- /* 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)
+
+ BITMAP_FREE (get_varinfo (from)->solution);
+ BITMAP_FREE (get_varinfo (from)->oldsolution);
+
+ 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->succs[n])
- {
- if (graph->preds[n])
- bitmap_clear_bit (graph->preds[n], n);
- bitmap_clear_bit (graph->succs[n], 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)
{
- bitmap temp;
bitmap_iterator bi;
unsigned int j;
SET_BIT (ti->visited, n);
- temp = graph->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);
}
0. */
if (ninfo->is_special_var
|| ninfo->is_artificial_var
- || ninfo->is_unknown_size_var)
+ || ninfo->is_unknown_size_var
+ || ninfo->is_full_var)
{
*offset = 0;
return true;
return (get_varinfo (n)->offset + *offset) < get_varinfo (n)->fullsize;
}
-/* Process a constraint C that represents *x = &y. */
+/* Process a constraint C that represents x = *y, using DELTA as the
+ starting solution. */
static void
-do_da_constraint (constraint_graph_t graph ATTRIBUTE_UNUSED,
- constraint_t c, bitmap delta)
+do_sd_constraint (constraint_graph_t graph, constraint_t c,
+ bitmap delta)
{
- unsigned int rhs = c->rhs.var;
+ unsigned int lhs = c->lhs.var;
+ bool flag = false;
+ bitmap sol = get_varinfo (lhs)->solution;
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)
+ if (bitmap_bit_p (delta, anything_id))
{
- 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;
+ flag |= bitmap_set_bit (sol, anything_id);
+ goto done;
+ }
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
+ /* For x = *ESCAPED and x = *CALLUSED we want to compute the
+ reachability set of the rhs var. As a pointer to a sub-field
+ of a variable can also reach all other fields of the variable
+ we simply have to expand the solution to contain all sub-fields
+ if one sub-field is contained. */
+ if (c->rhs.var == escaped_id
+ || c->rhs.var == callused_id)
+ {
+ bitmap vars = NULL;
+ /* In a first pass record all variables we need to add all
+ sub-fields off. This avoids quadratic behavior. */
+ EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
+ {
+ varinfo_t v = get_varinfo (j);
+ if (v->is_full_var)
continue;
- t = v->node;
- sol = get_varinfo (t)->solution;
- if (!bitmap_bit_p (sol, rhs))
+
+ v = lookup_vi_for_tree (v->decl);
+ if (v->next != NULL)
{
- bitmap_set_bit (sol, rhs);
- if (!TEST_BIT (changed, t))
+ 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)
{
- SET_BIT (changed, t);
- changed_count++;
+ if (bitmap_set_bit (sol, v->id))
+ {
+ flag = true;
+ bitmap_set_bit (delta, v->id);
+ }
}
}
+ BITMAP_FREE (vars);
}
- else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
- fprintf (dump_file, "Untypesafe usage in do_da_constraint.\n");
-
}
-}
-
-/* Process a constraint C that represents x = *y, using DELTA as the
- starting solution. */
-
-static void
-do_sd_constraint (constraint_graph_t graph, constraint_t c,
- bitmap delta)
-{
- unsigned int lhs = get_varinfo (c->lhs.var)->node;
- bool flag = false;
- bitmap sol = get_varinfo (lhs)->solution;
- unsigned int j;
- bitmap_iterator bi;
- 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
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 int t;
v = first_vi_for_offset (get_varinfo (j), fieldoffset);
+ /* If the access is outside of the variable we can ignore it. */
if (!v)
continue;
- t = v->node;
+ 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);
+ /* Merging the solution from ESCAPED needlessly increases
+ the set. Use ESCAPED as representative instead.
+ Same for CALLUSED. */
+ else if (get_varinfo (t)->id == escaped_id
+ || get_varinfo (t)->id == callused_id)
+ flag |= bitmap_set_bit (sol, get_varinfo (t)->id);
else if (add_graph_edge (graph, lhs, t))
flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
}
- else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
- fprintf (dump_file, "Untypesafe usage in do_sd_constraint\n");
-
}
done:
static void
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;
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;
+ v = get_varinfo (j);
+ if (!v->is_full_var)
+ {
+ v = first_vi_for_offset (v, fieldoffset);
+ /* If the access is outside of the variable we can ignore it. */
+ if (!v)
+ continue;
+ }
+ t = find (v->id);
- if (!bitmap_bit_p (get_varinfo (t)->solution, anything_id))
+ if (bitmap_set_bit (get_varinfo (t)->solution, anything_id)
+ && !TEST_BIT (changed, t))
{
- bitmap_set_bit (get_varinfo (t)->solution, anything_id);
- if (!TEST_BIT (changed, t))
- {
- SET_BIT (changed, t);
- changed_count++;
- }
+ SET_BIT (changed, t);
+ changed_count++;
}
}
return;
EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
{
unsigned HOST_WIDE_INT loff = c->lhs.offset;
- if (type_safe (j, &loff) && !(get_varinfo(j)->is_special_var))
+ if (type_safe (j, &loff) && !(get_varinfo (j)->is_special_var))
{
varinfo_t v;
unsigned int t;
bitmap tmp;
v = first_vi_for_offset (get_varinfo (j), fieldoffset);
+ /* If the access is outside of the variable we can ignore it. */
if (!v)
continue;
- t = v->node;
+ t = find (v->id);
tmp = get_varinfo (t)->solution;
- if (set_union_with_increment (tmp, sol, roff))
+ if (set_union_with_increment (tmp, sol, 0))
{
get_varinfo (t)->solution = tmp;
if (t == rhs)
}
}
}
- else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
- fprintf (dump_file, "Untypesafe usage in do_ds_constraint\n");
}
}
-/* 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
{
bitmap tmp;
bitmap solution;
bool flag = false;
- unsigned int t;
- gcc_assert(c->rhs.type == SCALAR && c->lhs.type == SCALAR);
- t = get_varinfo (c->rhs.var)->node;
- solution = get_varinfo (t)->solution;
- t = get_varinfo (c->lhs.var)->node;
- tmp = get_varinfo (t)->solution;
+ 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 (t)->solution = tmp;
+ get_varinfo (c->lhs.var)->solution = tmp;
if (!TEST_BIT (changed, c->lhs.var))
{
SET_BIT (changed, c->lhs.var);
/* 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;
}
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);
}
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);
}
+/* Structure used to for hash value numbering of pointer equivalence
+ classes. */
+
+typedef struct equiv_class_label
+{
+ unsigned int equivalence_class;
+ bitmap labels;
+ hashval_t hashcode;
+} *equiv_class_label_t;
+typedef const struct equiv_class_label *const_equiv_class_label_t;
+
+/* A hashtable for mapping a bitmap of labels->pointer equivalence
+ classes. */
+static htab_t pointer_equiv_class_table;
+
+/* A hashtable for mapping a bitmap of labels->location equivalence
+ classes. */
+static htab_t location_equiv_class_table;
+
+/* Hash function for a equiv_class_label_t */
+
+static hashval_t
+equiv_class_label_hash (const void *p)
+{
+ const_equiv_class_label_t const ecl = (const_equiv_class_label_t) p;
+ return ecl->hashcode;
+}
+
+/* Equality function for two equiv_class_label_t's. */
+
+static int
+equiv_class_label_eq (const void *p1, const void *p2)
+{
+ const_equiv_class_label_t const eql1 = (const_equiv_class_label_t) p1;
+ const_equiv_class_label_t const eql2 = (const_equiv_class_label_t) p2;
+ return bitmap_equal_p (eql1->labels, eql2->labels);
+}
+
+/* Lookup a equivalence class in TABLE by the bitmap of LABELS it
+ contains. */
+
+static unsigned int
+equiv_class_lookup (htab_t table, bitmap labels)
+{
+ void **slot;
+ struct equiv_class_label ecl;
+
+ ecl.labels = labels;
+ ecl.hashcode = bitmap_hash (labels);
+
+ slot = htab_find_slot_with_hash (table, &ecl,
+ ecl.hashcode, NO_INSERT);
+ if (!slot)
+ return 0;
+ else
+ return ((equiv_class_label_t) *slot)->equivalence_class;
+}
+
+
+/* Add an equivalence class named EQUIVALENCE_CLASS with labels LABELS
+ to TABLE. */
+
+static void
+equiv_class_add (htab_t table, unsigned int equivalence_class,
+ bitmap labels)
+{
+ void **slot;
+ equiv_class_label_t ecl = XNEW (struct equiv_class_label);
+
+ ecl->labels = labels;
+ ecl->equivalence_class = equivalence_class;
+ ecl->hashcode = bitmap_hash (labels);
+
+ slot = htab_find_slot_with_hash (table, ecl,
+ ecl->hashcode, INSERT);
+ gcc_assert (!*slot);
+ *slot = (void *) ecl;
+}
+
/* Perform offline variable substitution.
- This is a 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.
+ This is a worst case quadratic time way of identifying variables
+ that must have equivalent points-to sets, including those caused by
+ static cycles, and single entry subgraphs, in the constraint graph.
+
+ The technique is described in "Exploiting Pointer and Location
+ Equivalence to Optimize Pointer Analysis. In the 14th International
+ Static Analysis Symposium (SAS), August 2007." It is known as the
+ "HU" algorithm, and is equivalent to value numbering the collapsed
+ constraint graph including evaluating unions.
+
+ The general method of finding equivalence classes is as follows:
+ Add fake nodes (REF nodes) and edges for *a = b and a = *b constraints.
+ Initialize all non-REF nodes to be direct nodes.
+ For each constraint a = a U {b}, we set pts(a) = pts(a) u {fresh
+ variable}
+ For each constraint containing the dereference, we also do the same
+ thing.
+
+ We then compute SCC's in the graph and unify nodes in the same SCC,
+ including pts sets.
+
+ For each non-collapsed node x:
+ Visit all unvisited explicit incoming edges.
+ Ignoring all non-pointers, set pts(x) = Union of pts(a) for y
+ where y->x.
+ Lookup the equivalence class for pts(x).
+ If we found one, equivalence_class(x) = found class.
+ Otherwise, equivalence_class(x) = new class, and new_class is
+ added to the lookup table.
+
+ All direct nodes with the same equivalence class can be replaced
+ with a single representative node.
+ All unlabeled nodes (label == 0) are not pointers and all edges
+ involving them can be eliminated.
+ We perform these optimizations during rewrite_constraints
+
+ In addition to pointer equivalence class finding, we also perform
+ location equivalence class finding. This is the set of variables
+ that always appear together in points-to sets. We use this to
+ compress the size of the points-to sets. */
+
+/* Current maximum pointer equivalence class id. */
+static int pointer_equiv_class;
+
+/* Current maximum location equivalence class id. */
+static int location_equiv_class;
+
+/* Recursive routine to find strongly connected components in GRAPH,
+ and label it's nodes with DFS numbers. */
+
+static void
+condense_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
+{
+ unsigned int i;
+ bitmap_iterator bi;
+ unsigned int my_dfs;
+
+ gcc_assert (si->node_mapping[n] == n);
+ SET_BIT (si->visited, n);
+ si->dfs[n] = si->current_index ++;
+ my_dfs = si->dfs[n];
+
+ /* Visit all the successors. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
+ {
+ unsigned int w = si->node_mapping[i];
+
+ if (TEST_BIT (si->deleted, w))
+ continue;
+
+ if (!TEST_BIT (si->visited, w))
+ condense_visit (graph, si, w);
+ {
+ unsigned int t = si->node_mapping[w];
+ unsigned int nnode = si->node_mapping[n];
+ gcc_assert (nnode == n);
+
+ if (si->dfs[t] < si->dfs[nnode])
+ si->dfs[n] = si->dfs[t];
+ }
+ }
+
+ /* Visit all the implicit predecessors. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->implicit_preds[n], 0, i, bi)
+ {
+ unsigned int w = si->node_mapping[i];
+
+ if (TEST_BIT (si->deleted, w))
+ continue;
+
+ if (!TEST_BIT (si->visited, w))
+ condense_visit (graph, si, w);
+ {
+ unsigned int t = si->node_mapping[w];
+ unsigned int nnode = si->node_mapping[n];
+ gcc_assert (nnode == n);
+
+ if (si->dfs[t] < si->dfs[nnode])
+ si->dfs[n] = si->dfs[t];
+ }
+ }
+
+ /* See if any components have been identified. */
+ if (si->dfs[n] == my_dfs)
+ {
+ while (VEC_length (unsigned, si->scc_stack) != 0
+ && si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
+ {
+ unsigned int w = VEC_pop (unsigned, si->scc_stack);
+ si->node_mapping[w] = n;
+
+ if (!TEST_BIT (graph->direct_nodes, w))
+ RESET_BIT (graph->direct_nodes, n);
+
+ /* Unify our nodes. */
+ if (graph->preds[w])
+ {
+ if (!graph->preds[n])
+ graph->preds[n] = BITMAP_ALLOC (&predbitmap_obstack);
+ bitmap_ior_into (graph->preds[n], graph->preds[w]);
+ }
+ if (graph->implicit_preds[w])
+ {
+ if (!graph->implicit_preds[n])
+ graph->implicit_preds[n] = BITMAP_ALLOC (&predbitmap_obstack);
+ bitmap_ior_into (graph->implicit_preds[n],
+ graph->implicit_preds[w]);
+ }
+ if (graph->points_to[w])
+ {
+ if (!graph->points_to[n])
+ graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack);
+ bitmap_ior_into (graph->points_to[n],
+ graph->points_to[w]);
+ }
+ }
+ SET_BIT (si->deleted, n);
+ }
+ else
+ VEC_safe_push (unsigned, heap, si->scc_stack, n);
+}
- 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. */
+/* Label pointer equivalences. */
static void
+label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
+{
+ unsigned int i;
+ bitmap_iterator bi;
+ SET_BIT (si->visited, n);
+
+ if (!graph->points_to[n])
+ graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack);
+
+ /* Label and union our incoming edges's points to sets. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
+ {
+ unsigned int w = si->node_mapping[i];
+ if (!TEST_BIT (si->visited, w))
+ label_visit (graph, si, w);
+
+ /* Skip unused edges */
+ if (w == n || graph->pointer_label[w] == 0)
+ continue;
+
+ if (graph->points_to[w])
+ bitmap_ior_into(graph->points_to[n], graph->points_to[w]);
+ }
+ /* Indirect nodes get fresh variables. */
+ if (!TEST_BIT (graph->direct_nodes, n))
+ bitmap_set_bit (graph->points_to[n], FIRST_REF_NODE + n);
+
+ if (!bitmap_empty_p (graph->points_to[n]))
+ {
+ unsigned int label = equiv_class_lookup (pointer_equiv_class_table,
+ graph->points_to[n]);
+ if (!label)
+ {
+ label = pointer_equiv_class++;
+ equiv_class_add (pointer_equiv_class_table,
+ label, graph->points_to[n]);
+ }
+ graph->pointer_label[n] = label;
+ }
+}
+
+/* Perform offline variable substitution, discovering equivalence
+ classes, and eliminating non-pointer variables. */
+
+static struct scc_info *
perform_var_substitution (constraint_graph_t graph)
{
- struct topo_info *ti = init_topo_info ();
+ unsigned int i;
+ unsigned int size = graph->size;
+ struct scc_info *si = init_scc_info (size);
bitmap_obstack_initialize (&iteration_obstack);
- /* Compute the topological ordering of the graph, then visit each
- node in topological order. */
- compute_topo_order (graph, ti);
+ 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]);
- while (VEC_length (unsigned, ti->topo_order) != 0)
+ sbitmap_zero (si->visited);
+ /* Actually the label the nodes for pointer equivalences */
+ for (i = 0; i < FIRST_REF_NODE; i++)
+ if (!TEST_BIT (si->visited, si->node_mapping[i]))
+ label_visit (graph, si, si->node_mapping[i]);
+
+ /* Calculate location equivalence labels. */
+ for (i = 0; i < FIRST_REF_NODE; i++)
{
- unsigned int i = VEC_pop (unsigned, ti->topo_order);
- varinfo_t vi = get_varinfo (i);
- bool okay_to_elim = false;
- unsigned int root = VEC_length (varinfo_t, varmap);
- bitmap tmp;
- unsigned int k;
+ bitmap pointed_by;
bitmap_iterator bi;
+ unsigned int j;
+ unsigned int label;
- /* We can't eliminate things whose address is taken, or which is
- the target of a dereference. */
- if (vi->address_taken || vi->indirect_target)
+ if (!graph->pointed_by[i])
continue;
+ pointed_by = BITMAP_ALLOC (&iteration_obstack);
- /* See if all predecessors of I are ripe for elimination */
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[i], 0, k, bi)
- {
- unsigned int w;
- w = get_varinfo (k)->node;
+ /* 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;
- /* 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);
- }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ for (i = 0; i < FIRST_REF_NODE; i++)
+ {
+ bool direct_node = TEST_BIT (graph->direct_nodes, i);
+ fprintf (dump_file,
+ "Equivalence classes for %s node id %d:%s are pointer: %d"
+ ", location:%d\n",
+ direct_node ? "Direct node" : "Indirect node", i,
+ get_varinfo (i)->name,
+ graph->pointer_label[si->node_mapping[i]],
+ graph->loc_label[si->node_mapping[i]]);
+ }
+
+ /* Quickly eliminate our non-pointer variables. */
+
+ for (i = 0; i < FIRST_REF_NODE; i++)
+ {
+ unsigned int node = si->node_mapping[i];
+
+ if (graph->pointer_label[node] == 0)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "%s is a non-pointer variable, eliminating edges.\n",
+ get_varinfo (node)->name);
+ stats.nonpointer_vars++;
+ clear_edges_for_node (graph, node);
+ }
+ }
+
+ return si;
+}
+
+/* Free information that was only necessary for variable
+ substitution. */
+
+static void
+free_var_substitution_info (struct scc_info *si)
+{
+ free_scc_info (si);
+ free (graph->pointer_label);
+ free (graph->loc_label);
+ free (graph->pointed_by);
+ free (graph->points_to);
+ free (graph->eq_rep);
+ sbitmap_free (graph->direct_nodes);
+ htab_delete (pointer_equiv_class_table);
+ htab_delete (location_equiv_class_table);
+ bitmap_obstack_release (&iteration_obstack);
+}
+
+/* Return an existing node that is equivalent to NODE, which has
+ equivalence class LABEL, if one exists. Return NODE otherwise. */
+
+static unsigned int
+find_equivalent_node (constraint_graph_t graph,
+ unsigned int node, unsigned int label)
+{
+ /* If the address version of this variable is unused, we can
+ substitute it for anything else with the same label.
+ Otherwise, we know the pointers are equivalent, but not the
+ locations, and we can unite them later. */
+
+ if (!bitmap_bit_p (graph->address_taken, node))
+ {
+ gcc_assert (label < graph->size);
+
+ if (graph->eq_rep[label] != -1)
+ {
+ /* Unify the two variables since we know they are equivalent. */
+ if (unite (graph->eq_rep[label], node))
+ unify_nodes (graph, graph->eq_rep[label], node, false);
+ return graph->eq_rep[label];
+ }
+ else
+ {
+ graph->eq_rep[label] = node;
+ graph->pe_rep[label] = node;
+ }
+ }
+ else
+ {
+ gcc_assert (label < graph->size);
+ graph->pe[node] = label;
+ if (graph->pe_rep[label] == -1)
+ graph->pe_rep[label] = node;
+ }
+
+ return node;
+}
+
+/* Unite pointer equivalent but not location equivalent nodes in
+ GRAPH. This may only be performed once variable substitution is
+ finished. */
+
+static void
+unite_pointer_equivalences (constraint_graph_t graph)
+{
+ unsigned int i;
+
+ /* Go through the pointer equivalences and unite them to their
+ representative, if they aren't already. */
+ for (i = 0; i < FIRST_REF_NODE; i++)
+ {
+ unsigned int label = graph->pe[i];
+ if (label)
+ {
+ int label_rep = graph->pe_rep[label];
+
+ if (label_rep == -1)
+ continue;
+
+ label_rep = find (label_rep);
+ if (label_rep >= 0 && unite (label_rep, find (i)))
+ unify_nodes (graph, label_rep, i, false);
+ }
+ }
+}
+
+/* Move complex constraints to the GRAPH nodes they belong to. */
+
+static void
+move_complex_constraints (constraint_graph_t graph)
+{
+ int i;
+ constraint_t c;
+
+ for (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 (get_varinfo_fc (lhs.var)->id);
+ unsigned int rhsvar = find (get_varinfo_fc (rhs.var)->id);
+ 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);
+ }
+ }
- /* 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)
+ for (queuepos = 0;
+ VEC_iterate (unsigned, queue, queuepos, i);
+ queuepos++)
{
- /* Found an equivalence */
- get_varinfo (i)->node = root;
- collapse_nodes (graph, root, i, true);
- 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++;
+ unify_nodes (graph, to, i, true);
}
+ VEC_free (unsigned, heap, queue);
+ return true;
}
-
- bitmap_obstack_release (&iteration_obstack);
- free_topo_info (ti);
+ return false;
}
/* Solve the constraint graph GRAPH using our worklist solver.
static void
solve_graph (constraint_graph_t graph)
{
- unsigned int size = VEC_length (varinfo_t, varmap);
+ unsigned int size = graph->size;
unsigned int i;
+ bitmap pts;
- changed_count = size;
+ changed_count = 0;
changed = sbitmap_alloc (size);
- sbitmap_ones (changed);
+ sbitmap_zero (changed);
- /* The already collapsed/unreachable nodes will never change, so we
- need to account for them in changed_count. */
+ /* Mark all initial non-collapsed nodes as changed. */
for (i = 0; i < size; i++)
- if (get_varinfo (i)->node != i)
- changed_count--;
+ {
+ 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)
{
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);
-
- edge_added = false;
- }
-
compute_topo_order (graph, ti);
while (VEC_length (unsigned, ti->topo_order) != 0)
{
+
i = VEC_pop (unsigned, ti->topo_order);
- gcc_assert (get_varinfo (i)->node == i);
+
+ /* 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. */
unsigned int j;
constraint_t c;
bitmap solution;
- bitmap_iterator bi;
- VEC(constraint_t,heap) *complex = get_varinfo (i)->complex;
+ 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, solution);
+ do_complex_constraint (graph, c, pts);
}
solution_empty = bitmap_empty_p (solution);
- if (!solution_empty)
+ if (!solution_empty
+ /* Do not propagate the ESCAPED/CALLUSED solutions. */
+ && i != escaped_id
+ && i != callused_id)
{
+ bitmap_iterator bi;
+
/* Propagate solution to all successors. */
EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i],
0, j, bi)
{
- bitmap tmp = get_varinfo (j)->solution;
- bool flag = false;
+ bitmap tmp;
+ bool flag;
- gcc_assert (get_varinfo (j)->node == j);
+ unsigned int to = find (j);
+ tmp = get_varinfo (to)->solution;
+ flag = false;
- flag = set_union_with_increment (tmp, solution, 0);
+ /* Don't try to propagate to ourselves. */
+ if (to == i)
+ continue;
+
+ flag = set_union_with_increment (tmp, pts, 0);
if (flag)
{
- get_varinfo (j)->solution = tmp;
- if (!TEST_BIT (changed, j))
+ get_varinfo (to)->solution = tmp;
+ if (!TEST_BIT (changed, to))
{
- SET_BIT (changed, j);
+ SET_BIT (changed, to);
changed_count++;
}
}
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;
-/* CONSTRAINT AND VARIABLE GENERATION FUNCTIONS */
-
-/* Map from trees to variable ids. */
-static htab_t id_for_tree;
-
-typedef struct tree_id
-{
- tree t;
- unsigned int id;
-} *tree_id_t;
-
-/* Hash a tree id structure. */
-
-static hashval_t
-tree_id_hash (const void *p)
-{
- const tree_id_t ta = (tree_id_t) p;
- return htab_hash_pointer (ta->t);
-}
-
-/* Return true if the tree in P1 and the tree in P2 are the same. */
-
-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;
-}
-/* Insert ID as the variable id for tree T in the hashtable. */
+/* Insert ID as the variable id for tree T in the vi_for_tree map. */
static void
-insert_id_for_tree (tree t, int id)
+insert_vi_for_tree (tree t, varinfo_t vi)
{
- void **slot;
- struct tree_id finder;
- tree_id_t new_pair;
-
- finder.t = t;
- slot = htab_find_slot (id_for_tree, &finder, INSERT);
+ void **slot = pointer_map_insert (vi_for_tree, t);
+ gcc_assert (vi);
gcc_assert (*slot == NULL);
- new_pair = XNEW (struct tree_id);
- new_pair->t = t;
- new_pair->id = id;
- *slot = (void *)new_pair;
+ *slot = vi;
}
-/* 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. */
+/* 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 bool
-lookup_id_for_tree (tree t, unsigned int *id)
+static varinfo_t
+lookup_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 NULL;
- finder.t = t;
- pair = htab_find (id_for_tree, &finder);
- if (pair == NULL)
- return false;
- *id = pair->id;
- return true;
+ return (varinfo_t) *slot;
}
/* Return a printable name for 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;
-
- finder.t = t;
- pair = htab_find (id_for_tree, &finder);
- if (pair == NULL)
- return create_variable_info_for (t, alias_get_name (t));
+ void **slot = pointer_map_contains (vi_for_tree, t);
+ if (slot == NULL)
+ return get_varinfo (create_variable_info_for (t, alias_get_name (t)));
- return pair->id;
+ return (varinfo_t) *slot;
}
-/* Get a constraint expression from an SSA_VAR_P node. */
+/* Get a constraint expression for a new temporary variable. */
static struct constraint_expr
-get_constraint_exp_from_ssa_var (tree t)
+get_constraint_exp_for_temp (tree t)
+{
+ struct constraint_expr cexpr;
+
+ gcc_assert (SSA_VAR_P (t));
+
+ cexpr.type = SCALAR;
+ cexpr.var = get_vi_for_tree (t)->id;
+ cexpr.offset = 0;
+
+ return cexpr;
+}
+
+/* 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
- && gimple_default_def (cfun, SSA_NAME_VAR (t)) == t)
- return get_constraint_exp_from_ssa_var (SSA_NAME_VAR (t));
+ && 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))
{
- cexpr.type = INCLUDES;
+ 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)
+ {
+ 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)
gcc_assert (rhs.var < VEC_length (varinfo_t, varmap));
gcc_assert (lhs.var < VEC_length (varinfo_t, varmap));
- gcc_assert (lhs.type != INCLUDES);
-
- if (lhs.type == DEREF)
- get_varinfo (lhs.var)->directly_dereferenced = true;
- if (rhs.type == DEREF)
- get_varinfo (rhs.var)->directly_dereferenced = true;
-
- if (!use_field_sensitive)
- {
- t->rhs.offset = 0;
- t->lhs.offset = 0;
- }
-
/* ANYTHING == ANYTHING is pointless. */
if (lhs.var == anything_id && rhs.var == anything_id)
return;
/* If we have &ANYTHING = something, convert to SOMETHING = &ANYTHING) */
- else if (lhs.var == anything_id
- && (lhs.type == INCLUDES || lhs.type == ADDRESSOF))
+ else if (lhs.var == anything_id && lhs.type == ADDRESSOF)
{
rhs = t->lhs;
t->lhs = t->rhs;
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 = get_constraint_exp_for_temp (tmpvar);
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;
+ /* Split into tmp = &rhs, *lhs = tmp */
+ tree rhsdecl = get_varinfo (rhs.var)->decl;
+ tree pointertype = TREE_TYPE (rhsdecl);
+ tree tmpvar = create_tmp_var_raw (pointertype, "derefaddrtmp");
+ struct constraint_expr tmplhs = get_constraint_exp_for_temp (tmpvar);
- VEC_safe_push (constraint_t, heap, constraints, t);
+ 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);
}
}
{
tree type = TREE_TYPE (t);
- if (POINTER_TYPE_P (type) || AGGREGATE_TYPE_P (type)
- || TREE_CODE (type) == COMPLEX_TYPE)
+ if (POINTER_TYPE_P (type)
+ || AGGREGATE_TYPE_P (type))
return true;
+
return false;
}
/* 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 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)
+static void
+get_constraint_for_ptr_offset (tree ptr, tree offset,
+ VEC (ce_s, heap) **results)
{
- if (fieldpos == accesspos && fieldsize == accesssize)
- return true;
- if (accesspos >= fieldpos && accesspos < (fieldpos + fieldsize))
- return true;
- if (accesspos < fieldpos && (accesspos + accesssize > fieldpos))
- return true;
+ struct constraint_expr *c;
+ unsigned int j, n;
+ unsigned HOST_WIDE_INT rhsunitoffset, rhsoffset;
- return false;
+ /* 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.
+ ??? As we do not have the ability to express this, fall back
+ to anything. */
+ if (!host_integerp (offset, 1))
+ {
+ struct constraint_expr temp;
+ temp.var = anything_id;
+ temp.type = SCALAR;
+ temp.offset = 0;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
+ }
+
+ /* Make sure the bit-offset also fits. */
+ rhsunitoffset = TREE_INT_CST_LOW (offset);
+ rhsoffset = rhsunitoffset * BITS_PER_UNIT;
+ if (rhsunitoffset != rhsoffset / BITS_PER_UNIT)
+ {
+ struct constraint_expr temp;
+ temp.var = anything_id;
+ temp.type = SCALAR;
+ temp.offset = 0;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
+ }
+
+ get_constraint_for (ptr, results);
+ if (rhsoffset == 0)
+ return;
+
+ /* As we are eventually appending to the solution do not use
+ VEC_iterate here. */
+ n = VEC_length (ce_s, *results);
+ for (j = 0; j < n; j++)
+ {
+ varinfo_t curr;
+ c = VEC_index (ce_s, *results, j);
+ curr = get_varinfo (c->var);
+
+ if (c->type == ADDRESSOF
+ && !curr->is_full_var)
+ {
+ varinfo_t temp, curr = get_varinfo (c->var);
+
+ /* Search the sub-field which overlaps with the
+ pointed-to offset. As we deal with positive offsets
+ only, we can start the search from the current variable. */
+ temp = first_vi_for_offset (curr, curr->offset + rhsoffset);
+
+ /* 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 sub-field is such
+ a conservative result.
+ ??? If we always had a sub-field for &object + 1 then
+ we could represent this in a more precise way. */
+ if (temp == NULL)
+ {
+ temp = curr;
+ while (temp->next != NULL)
+ temp = temp->next;
+ continue;
+ }
+
+ /* 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 != curr->offset + rhsoffset
+ && 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 if (c->type == ADDRESSOF
+ /* If this varinfo represents a full variable just use it. */
+ && curr->is_full_var)
+ c->offset = 0;
+ else
+ c->offset = rhsoffset;
+ }
}
-/* 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 */
t = get_ref_base_and_extent (t, &bitpos, &bitsize, &bitmaxsize);
- /* String constants are readonly, so there is nothing to really do
- here. */
- if (TREE_CODE (t) == STRING_CST)
- return;
-
- get_constraint_for (t, 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);
- result->offset = bitpos;
-
- gcc_assert (beforelength + 1 == VEC_length (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. */
+ 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 (bitmaxsize == -1)
+ {
+ /* We can't handle DEREF constraints with unknown size, we'll
+ get the wrong answer. Punt and return anything. */
+ result->var = anything_id;
result->offset = 0;
}
+ else
+ result->offset = bitpos;
}
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 = get_constraint_exp_for_temp (tmpvar);
process_constraint (new_constraint (tmplhs, *c));
c->var = tmplhs.var;
}
/* 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;
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)))
+ && integer_zerop (t))
{
- 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;
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;
-
- if (VEC_length (ce_s, *results) == 0)
- return;
-
- 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);
- }
- }
+
+ get_constraint_for_1 (exp, results, true);
for (i = 0; VEC_iterate (ce_s, *results, i, c); i++)
{
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;
- get_var_ann (heapvar)->is_heapvar = 1;
- if (gimple_referenced_vars (cfun))
- 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 = INCLUDES;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
- return;
- }
- else
- {
- temp.var = anything_id;
- temp.type = SCALAR;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
- return;
- }
- break;
- default:
- {
- temp.type = ADDRESSOF;
- temp.var = anything_id;
- temp.offset = 0;
- VEC_safe_push (ce_s, heap, *results, &temp);
- 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;
- }
+ 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);
- return;
- }
- break;
- 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:;
}
+ 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);
+}
/* Handle the structure copy case where we have a simple structure copy
between LHS and RHS that is of SIZE (in bits)
}
/* Handle the structure copy case where we have a structure copy
- between a aggregate on the RHS and a dereference of a pointer on
+ between an aggregate on the RHS and a dereference of a pointer on
the LHS that is of SIZE (in bits)
For each field of the rhs variable (rhsfield)
fprintf (dump_file, "Type safety: Collapsing var %s into %s\n",
field->name, currvar->name);
- gcc_assert (!field->collapsed_to);
- field->collapsed_to = currvar;
+ gcc_assert (field->collapsed_to == 0);
+ field->collapsed_to = currvar->id;
}
currvar->next = NULL;
unsigned HOST_WIDE_INT lhssize;
unsigned HOST_WIDE_INT rhssize;
- get_constraint_for (lhsop, &lhsc);
- get_constraint_for (rhsop, &rhsc);
+ /* Pretend we are taking the address of the constraint exprs.
+ We deal with walking the sub-fields ourselves. */
+ get_constraint_for_1 (lhsop, &lhsc, true);
+ get_constraint_for_1 (rhsop, &rhsc, true);
gcc_assert (VEC_length (ce_s, lhsc) == 1);
gcc_assert (VEC_length (ce_s, rhsc) == 1);
lhs = *(VEC_last (ce_s, 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. */
+/* Create a constraint ID = OP. */
static void
-update_alias_info (tree stmt, struct alias_info *ai)
+make_constraint_to (unsigned id, tree op)
{
- bitmap addr_taken;
- use_operand_p use_p;
- ssa_op_iter iter;
- enum escape_type stmt_escape_type = is_escape_site (stmt);
- tree op;
-
- if (stmt_escape_type == ESCAPE_TO_CALL
- || stmt_escape_type == ESCAPE_TO_PURE_CONST)
- {
- ai->num_calls_found++;
- if (stmt_escape_type == ESCAPE_TO_PURE_CONST)
- ai->num_pure_const_calls_found++;
- }
-
- /* Mark all the variables whose address are taken by the statement. */
- addr_taken = addresses_taken (stmt);
- if (addr_taken)
- {
- bitmap_ior_into (gimple_addressable_vars (cfun), 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);
- }
- }
- }
-
- /* 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)
- {
- tree op, var;
- var_ann_t v_ann;
- struct ptr_info_def *pi;
- bool is_store, is_potential_deref;
- unsigned num_uses, num_derefs;
+ VEC(ce_s, heap) *rhsc = NULL;
+ struct constraint_expr *c;
+ struct constraint_expr includes;
+ unsigned int j;
- op = USE_FROM_PTR (use_p);
+ includes.var = id;
+ includes.offset = 0;
+ includes.type = SCALAR;
- /* 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)
- {
- bitmap addressable_vars = gimple_addressable_vars (cfun);
+ 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);
+}
- gcc_assert (TREE_CODE (stmt) == PHI_NODE);
- gcc_assert (addressable_vars);
+/* Make constraints necessary to make OP escape. */
- /* PHI nodes don't have annotations for pinning the set
- of addresses taken, so we collect them here.
+static void
+make_escape_constraint (tree op)
+{
+ make_constraint_to (escaped_id, op);
+}
- 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;
- }
+/* For non-IPA mode, generate constraints necessary for a call on the
+ RHS. */
- /* Ignore constants. */
- if (TREE_CODE (op) != SSA_NAME)
- continue;
+static void
+handle_rhs_call (gimple stmt)
+{
+ unsigned i;
- var = SSA_NAME_VAR (op);
- v_ann = var_ann (var);
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
+ {
+ tree arg = gimple_call_arg (stmt, i);
- /* The base variable of an ssa name must be a GIMPLE register, and thus
- it cannot be aliased. */
- gcc_assert (!may_be_aliased (var));
+ /* Find those pointers being passed, and make sure they end up
+ pointing to anything. */
+ if (could_have_pointers (arg))
+ make_escape_constraint (arg);
+ }
- /* We are only interested in pointers. */
- if (!POINTER_TYPE_P (TREE_TYPE (op)))
- continue;
+ /* The static chain escapes as well. */
+ if (gimple_call_chain (stmt))
+ make_escape_constraint (gimple_call_chain (stmt));
+}
- pi = get_ptr_info (op);
+/* 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. */
- /* 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);
- }
+static void
+handle_lhs_call (tree lhs, int flags)
+{
+ VEC(ce_s, heap) *lhsc = NULL;
+ struct constraint_expr rhsc;
+ unsigned int j;
+ struct constraint_expr *lhsp;
- /* 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;
+ get_constraint_for (lhs, &lhsc);
- /* 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) == GIMPLE_MODIFY_STMT
- && TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)) == ADDR_EXPR
- && !is_gimple_val (GIMPLE_STMT_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 = GIMPLE_STMT_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;
- }
+ if (flags & ECF_MALLOC)
+ {
+ tree heapvar = heapvar_lookup (lhs);
+ varinfo_t vi;
- if (num_derefs > 0 || is_potential_deref)
+ if (heapvar == NULL)
{
- /* 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));
+ heapvar = create_tmp_var_raw (ptr_type_node, "HEAP");
+ DECL_EXTERNAL (heapvar) = 1;
+ get_var_ann (heapvar)->is_heapvar = 1;
+ if (gimple_referenced_vars (cfun))
+ add_referenced_var (heapvar);
+ heapvar_insert (lhs, heapvar);
}
- if (stmt_escape_type != NO_ESCAPE && num_derefs < num_uses)
- {
- /* 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)
- || stmt_escape_type == ESCAPE_STORED_IN_GLOBAL)
- {
- bitmap_set_bit (ai->dereferenced_ptrs_store, DECL_UID (var));
- pi->is_dereferenced = 1;
- }
- }
+ rhsc.var = create_variable_info_for (heapvar,
+ alias_get_name (heapvar));
+ vi = get_varinfo (rhsc.var);
+ vi->is_artificial_var = 1;
+ vi->is_heap_var = 1;
+ rhsc.type = ADDRESSOF;
+ rhsc.offset = 0;
+ }
+ else
+ {
+ rhsc.var = escaped_id;
+ rhsc.offset = 0;
+ rhsc.type = ADDRESSOF;
}
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhsc));
+ VEC_free (ce_s, heap, lhsc);
+}
- if (TREE_CODE (stmt) == PHI_NODE)
- return;
+/* For non-IPA mode, generate constraints necessary for a call of a
+ const function that returns a pointer in the statement STMT. */
- /* 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)
- {
- 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);
+static void
+handle_const_call (gimple stmt)
+{
+ tree lhs = gimple_call_lhs (stmt);
+ VEC(ce_s, heap) *lhsc = NULL;
+ struct constraint_expr rhsc;
+ unsigned int j, k;
+ struct constraint_expr *lhsp;
+ tree tmpvar;
+ struct constraint_expr tmpc;
- }
+ get_constraint_for (lhs, &lhsc);
- /* Mark variables in V_MAY_DEF operands as being written to. */
- FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_VIRTUAL_DEFS)
+ /* If this is a nested function then it can return anything. */
+ if (gimple_call_chain (stmt))
{
- tree var = DECL_P (op) ? op : SSA_NAME_VAR (op);
- bitmap_set_bit (ai->written_vars, DECL_UID (var));
+ rhsc.var = anything_id;
+ rhsc.offset = 0;
+ rhsc.type = ADDRESSOF;
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhsc));
+ VEC_free (ce_s, heap, lhsc);
+ return;
}
-}
+ /* We always use a temporary here, otherwise we end up with a quadratic
+ amount of constraints for
+ large_struct = const_call (large_struct);
+ in field-sensitive PTA. */
+ tmpvar = create_tmp_var_raw (ptr_type_node, "consttmp");
+ tmpc = get_constraint_exp_for_temp (tmpvar);
+
+ /* May return addresses of globals. */
+ rhsc.var = nonlocal_id;
+ rhsc.offset = 0;
+ rhsc.type = ADDRESSOF;
+ process_constraint (new_constraint (tmpc, rhsc));
+
+ /* May return arguments. */
+ for (k = 0; k < gimple_call_num_args (stmt); ++k)
+ {
+ tree arg = gimple_call_arg (stmt, k);
-/* Handle pointer arithmetic EXPR when creating aliasing constraints.
- Expressions of the type PTR + CST can be handled in two ways:
-
- 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).
+ if (could_have_pointers (arg))
+ {
+ VEC(ce_s, heap) *argc = NULL;
+ struct constraint_expr *argp;
+ int i;
- 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.
+ get_constraint_for (arg, &argc);
+ for (i = 0; VEC_iterate (ce_s, argc, i, argp); i++)
+ process_constraint (new_constraint (tmpc, *argp));
+ VEC_free (ce_s, heap, argc);
+ }
+ }
- 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. */
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, tmpc));
-static bool
-handle_ptr_arith (VEC (ce_s, heap) *lhsc, tree expr)
-{
- 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;
+ VEC_free (ce_s, heap, lhsc);
+}
- if (TREE_CODE (expr) != PLUS_EXPR
- && TREE_CODE (expr) != MINUS_EXPR)
- return false;
+/* For non-IPA mode, generate constraints necessary for a call to a
+ pure function in statement STMT. */
- op0 = TREE_OPERAND (expr, 0);
- op1 = TREE_OPERAND (expr, 1);
+static void
+handle_pure_call (gimple stmt)
+{
+ unsigned i;
- get_constraint_for (op0, &temp);
- if (POINTER_TYPE_P (TREE_TYPE (op0))
- && TREE_CODE (op1) == INTEGER_CST
- && TREE_CODE (expr) == PLUS_EXPR)
+ /* Memory reached from pointer arguments is call-used. */
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
{
- rhsoffset = TREE_INT_CST_LOW (op1) * BITS_PER_UNIT;
+ tree arg = gimple_call_arg (stmt, i);
+
+ if (could_have_pointers (arg))
+ make_constraint_to (callused_id, arg);
}
+ /* The static chain is used as well. */
+ if (gimple_call_chain (stmt))
+ make_constraint_to (callused_id, gimple_call_chain (stmt));
- 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);
+ /* If the call returns a pointer it may point to reachable memory
+ from the arguments. Not so for malloc functions though. */
+ if (gimple_call_lhs (stmt)
+ && could_have_pointers (gimple_call_lhs (stmt))
+ && !(gimple_call_flags (stmt) & ECF_MALLOC))
+ {
+ tree lhs = gimple_call_lhs (stmt);
+ VEC(ce_s, heap) *lhsc = NULL;
+ struct constraint_expr rhsc;
+ struct constraint_expr *lhsp;
+ unsigned j;
- /* 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));
- }
+ get_constraint_for (lhs, &lhsc);
- VEC_free (ce_s, heap, temp);
+ /* If this is a nested function then it can return anything. */
+ if (gimple_call_chain (stmt))
+ {
+ rhsc.var = anything_id;
+ rhsc.offset = 0;
+ rhsc.type = ADDRESSOF;
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhsc));
+ VEC_free (ce_s, heap, lhsc);
+ return;
+ }
- return true;
+ /* Else just add the call-used memory here. Escaped variables
+ and globals will be dealt with in handle_lhs_call. */
+ rhsc.var = callused_id;
+ rhsc.offset = 0;
+ rhsc.type = ADDRESSOF;
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhsc));
+ VEC_free (ce_s, heap, lhsc);
+ }
}
-
/* 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);
+ enum escape_type stmt_escape_type;
/* 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 (could_have_pointers (PHI_RESULT (t)))
+ 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++)
+ get_constraint_for (gimple_phi_result (t), &lhsc);
+ for (i = 0; i < gimple_phi_num_args (t); i++)
{
tree rhstype;
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++)
{
}
}
/* 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) == GIMPLE_MODIFY_STMT
- && TREE_CODE (GIMPLE_STMT_OPERAND (t, 1)) == CALL_EXPR
- && !(call_expr_flags (GIMPLE_STMT_OPERAND (t, 1))
- & (ECF_MALLOC | ECF_MAY_BE_ALLOCA)))
- || (TREE_CODE (t) == CALL_EXPR
- && !(call_expr_flags (t)
- & (ECF_MALLOC | ECF_MAY_BE_ALLOCA)))))
+ 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 lhsop;
- tree rhsop;
- unsigned int varid;
- tree arglist;
- varinfo_t fi;
- int i = 1;
- tree decl;
- if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
- {
- lhsop = GIMPLE_STMT_OPERAND (t, 0);
- rhsop = GIMPLE_STMT_OPERAND (t, 1);
- }
- else
+ if (!in_ipa_mode)
{
- lhsop = NULL;
- rhsop = t;
- }
- decl = get_callee_fndecl (rhsop);
+ int flags = gimple_call_flags (t);
- /* 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)
- {
- varid = get_id_for_tree (decl);
+ /* Const functions can return their arguments and addresses
+ of global memory but not of escaped memory. */
+ if (flags & ECF_CONST)
+ {
+ if (gimple_call_lhs (t)
+ && could_have_pointers (gimple_call_lhs (t)))
+ handle_const_call (t);
+ }
+ /* 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)
+ {
+ handle_pure_call (t);
+ if (gimple_call_lhs (t)
+ && could_have_pointers (gimple_call_lhs (t)))
+ handle_lhs_call (gimple_call_lhs (t), flags);
+ }
+ else
+ {
+ handle_rhs_call (t);
+ if (gimple_call_lhs (t)
+ && could_have_pointers (gimple_call_lhs (t)))
+ handle_lhs_call (gimple_call_lhs (t), flags);
+ }
}
else
{
- decl = TREE_OPERAND (rhsop, 0);
- varid = get_id_for_tree (decl);
- }
-
- /* 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))
- {
- tree arg = TREE_VALUE (arglist);
- struct constraint_expr lhs ;
- struct constraint_expr *rhsp;
-
- get_constraint_for (arg, &rhsc);
- if (TREE_CODE (decl) != FUNCTION_DECL)
+ tree lhsop;
+ varinfo_t fi;
+ int i = 1;
+ size_t j;
+ tree decl;
+
+ lhsop = gimple_call_lhs (t);
+ decl = gimple_call_fndecl (t);
+
+ /* 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)
+ fi = get_vi_for_tree (decl);
+ else
{
- lhs.type = DEREF;
- lhs.var = fi->id;
- lhs.offset = i;
+ decl = gimple_call_fn (t);
+ fi = get_vi_for_tree (decl);
}
- else
+
+ /* Assign all the passed arguments to the appropriate incoming
+ parameters of the function. */
+ for (j = 0; j < gimple_call_num_args (t); j++)
{
- lhs.type = SCALAR;
- lhs.var = first_vi_for_offset (fi, i)->id;
- lhs.offset = 0;
+ struct constraint_expr lhs ;
+ struct constraint_expr *rhsp;
+ tree arg = gimple_call_arg (t, j);
+
+ get_constraint_for (arg, &rhsc);
+ if (TREE_CODE (decl) != FUNCTION_DECL)
+ {
+ lhs.type = DEREF;
+ lhs.var = fi->id;
+ lhs.offset = i;
+ }
+ else
+ {
+ lhs.type = SCALAR;
+ lhs.var = first_vi_for_offset (fi, i)->id;
+ lhs.offset = 0;
+ }
+ while (VEC_length (ce_s, rhsc) != 0)
+ {
+ rhsp = VEC_last (ce_s, rhsc);
+ process_constraint (new_constraint (lhs, *rhsp));
+ VEC_pop (ce_s, rhsc);
+ }
+ i++;
}
- while (VEC_length (ce_s, rhsc) != 0)
+
+ /* If we are returning a value, assign it to the result. */
+ if (lhsop)
{
- rhsp = VEC_last (ce_s, rhsc);
- process_constraint (new_constraint (lhs, *rhsp));
- VEC_pop (ce_s, rhsc);
+ struct constraint_expr rhs;
+ struct constraint_expr *lhsp;
+ unsigned int j = 0;
+
+ get_constraint_for (lhsop, &lhsc);
+ if (TREE_CODE (decl) != FUNCTION_DECL)
+ {
+ rhs.type = DEREF;
+ rhs.var = fi->id;
+ rhs.offset = i;
+ }
+ else
+ {
+ rhs.type = SCALAR;
+ rhs.var = first_vi_for_offset (fi, i)->id;
+ rhs.offset = 0;
+ }
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhs));
}
- 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;
+ }
+ /* 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
+ {
+ unsigned int j;
+ struct constraint_expr temp;
get_constraint_for (lhsop, &lhsc);
- if (TREE_CODE (decl) != FUNCTION_DECL)
+
+ 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
{
- rhs.type = DEREF;
- rhs.var = fi->id;
- rhs.offset = i;
+ temp.type = ADDRESSOF;
+ temp.var = anything_id;
+ temp.offset = 0;
+ VEC_safe_push (ce_s, heap, rhsc, &temp);
}
- else
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
{
- rhs.type = SCALAR;
- rhs.var = first_vi_for_offset (fi, i)->id;
- rhs.offset = 0;
+ struct constraint_expr *c2;
+ unsigned int k;
+
+ for (k = 0; VEC_iterate (ce_s, rhsc, k, c2); k++)
+ process_constraint (new_constraint (*c, *c2));
}
- 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) == GIMPLE_MODIFY_STMT)
+ else if (gimple_code (t) == GIMPLE_CHANGE_DYNAMIC_TYPE)
{
- tree lhsop = GIMPLE_STMT_OPERAND (t, 0);
- tree rhsop = GIMPLE_STMT_OPERAND (t, 1);
- int i;
-
- 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))
+ unsigned int j;
+
+ get_constraint_for (gimple_cdt_location (t), &lhsc);
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, c); ++j)
+ get_varinfo (c->var)->no_tbaa_pruning = true;
+ }
+
+ stmt_escape_type = is_escape_site (t);
+ if (stmt_escape_type == ESCAPE_STORED_IN_GLOBAL)
+ {
+ gcc_assert (is_gimple_assign (t));
+ if (gimple_assign_rhs_code (t) == ADDR_EXPR)
+ {
+ tree rhs = gimple_assign_rhs1 (t);
+ tree base = get_base_address (TREE_OPERAND (rhs, 0));
+ if (base
+ && (!DECL_P (base)
+ || !is_global_var (base)))
+ make_escape_constraint (rhs);
+ }
+ else if (get_gimple_rhs_class (gimple_assign_rhs_code (t))
+ == GIMPLE_SINGLE_RHS)
{
- do_structure_copy (lhsop, rhsop);
+ if (could_have_pointers (gimple_assign_rhs1 (t)))
+ make_escape_constraint (gimple_assign_rhs1 (t));
}
else
+ gcc_unreachable ();
+ }
+ else if (stmt_escape_type == ESCAPE_BAD_CAST)
+ {
+ gcc_assert (is_gimple_assign (t));
+ gcc_assert (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (t))
+ || gimple_assign_rhs_code (t) == VIEW_CONVERT_EXPR);
+ make_escape_constraint (gimple_assign_rhs1 (t));
+ }
+ else if (stmt_escape_type == ESCAPE_TO_ASM)
+ {
+ unsigned i;
+ for (i = 0; i < gimple_asm_noutputs (t); ++i)
{
- /* Only care about operations with pointers, structures
- containing pointers, dereferences, and call expressions. */
- if (could_have_pointers (lhsop)
- || 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;
-
- 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);
- }
- }
- }
- }
- }
+ tree op = TREE_VALUE (gimple_asm_output_op (t, i));
+ if (op && could_have_pointers (op))
+ /* Strictly we'd only need the constraints from ESCAPED and
+ NONLOCAL. */
+ make_escape_constraint (op);
+ }
+ for (i = 0; i < gimple_asm_ninputs (t); ++i)
+ {
+ tree op = TREE_VALUE (gimple_asm_input_op (t, i));
+ if (op && could_have_pointers (op))
+ /* Strictly we'd only need the constraint to ESCAPED. */
+ make_escape_constraint (op);
}
}
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);
+ if (!in_ipa_mode)
+ gimple_set_modified (origt, true);
VEC_free (ce_s, heap, rhsc);
VEC_free (ce_s, heap, lhsc);
}
}
}
+/* This structure is used during pushing fields onto the fieldstack
+ to track the offset of the field, since bitpos_of_field gives it
+ relative to its immediate containing type, and we want it relative
+ to the ultimate containing object. */
+
+struct fieldoff
+{
+ /* Offset from the base of the base containing object to this field. */
+ HOST_WIDE_INT offset;
+
+ /* Size, in bits, of the field. */
+ unsigned HOST_WIDE_INT size;
+
+ unsigned has_unknown_size : 1;
+
+ unsigned may_have_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
{
const fieldoff_s *foa = (const fieldoff_s *)pa;
const fieldoff_s *fob = (const fieldoff_s *)pb;
- HOST_WIDE_INT foasize, fobsize;
+ unsigned HOST_WIDE_INT foasize, fobsize;
- if (foa->offset != fob->offset)
- return foa->offset - fob->offset;
+ 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
+static void
sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
{
qsort (VEC_address (fieldoff_s, fieldstack),
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. */
+
+static inline bool
+var_can_have_subvars (const_tree v)
+{
+ /* Volatile variables should never have subvars. */
+ if (TREE_THIS_VOLATILE (v))
+ return false;
+
+ /* Non decls or memory tags can never have subvars. */
+ if (!DECL_P (v) || MTAG_P (v))
+ return false;
+
+ /* Aggregates without overlapping fields can have subvars. */
+ if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE)
+ return true;
+
+ return false;
+}
+
+/* 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. */
-int
+static int
push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
- HOST_WIDE_INT offset, bool *has_union)
+ HOST_WIDE_INT offset)
{
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;
- }
-
- if (TREE_CODE (type) == ARRAY_TYPE)
- {
- tree sz = TYPE_SIZE (type);
- tree elsz = TYPE_SIZE (TREE_TYPE (type));
- HOST_WIDE_INT nr;
- int i;
-
- 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;
-
- nr = TREE_INT_CST_LOW (sz) / TREE_INT_CST_LOW (elsz);
- if (nr > SALIAS_MAX_ARRAY_ELEMENTS)
- return 0;
-
- 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;
- }
+ if (TREE_CODE (type) != RECORD_TYPE)
+ return 0;
- return count;
- }
+ /* 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 0;
for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
if (TREE_CODE (field) == FIELD_DECL)
{
bool push = false;
int pushed = 0;
+ HOST_WIDE_INT foff = bitpos_of_field (field);
- 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))
+ 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
+ (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
+ && !could_have_pointers (field)
+ && !pair->has_unknown_size
+ && !has_unknown_size
+ && pair->offset + (HOST_WIDE_INT)pair->size == offset + foff)
+ {
+ pair = VEC_last (fieldoff_s, *fieldstack);
+ 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);
+ count++;
+ }
}
else
count += pushed;
return count;
}
-/* Create a constraint from ANYTHING variable to VI. */
+/* Create a constraint ID = &FROM. */
+
static void
-make_constraint_from_anything (varinfo_t vi)
+make_constraint_from (varinfo_t vi, int from)
{
struct constraint_expr lhs, rhs;
lhs.offset = 0;
lhs.type = SCALAR;
- rhs.var = anything_id;
+ rhs.var = from;
rhs.offset = 0;
- rhs.type = INCLUDES;
+ rhs.type = ADDRESSOF;
process_constraint (new_constraint (lhs, rhs));
}
/* Create the variable info. */
- vi = new_var_info (decl, index, name, index);
+ vi = new_var_info (decl, index, name);
vi->decl = decl;
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);
+ insert_vi_for_tree (vi->decl, vi);
VEC_safe_push (varinfo_t, heap, varmap, vi);
stats.total_vars++;
/* If it's varargs, we don't know how many arguments it has, so we
- can't do much.
- */
+ can't do much. */
if (is_varargs)
{
vi->fullsize = ~0;
newname = ggc_strdup (tempname);
free (tempname);
- argvi = new_var_info (argdecl, newindex,newname, newindex);
+ argvi = new_var_info (argdecl, newindex, newname);
argvi->decl = argdecl;
VEC_safe_push (varinfo_t, heap, varmap, argvi);
argvi->offset = 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)
{
- insert_id_for_tree (arg, newindex);
+ insert_vi_for_tree (arg, argvi);
arg = TREE_CHAIN (arg);
}
}
newname = ggc_strdup (tempname);
free (tempname);
- resultvi = new_var_info (resultdecl, newindex, newname, newindex);
+ resultvi = new_var_info (resultdecl, newindex, newname);
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;
+ resultvi->is_full_var = true;
insert_into_field_list_sorted (vi, resultvi);
stats.total_vars ++;
if (DECL_RESULT (decl))
- insert_id_for_tree (DECL_RESULT (decl), newindex);
+ insert_vi_for_tree (DECL_RESULT (decl), resultvi);
}
return index;
}
{
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;
+ tree decl_type = TREE_TYPE (decl);
+ tree declsize = DECL_P (decl) ? DECL_SIZE (decl) : TYPE_SIZE (decl_type);
bool is_global = DECL_P (decl) ? is_global_var (decl) : false;
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;
- }
- }
-
+ if (var_can_have_subvars (decl) && use_field_sensitive
+ && (!var_ann (decl)
+ || var_ann (decl)->noalias_state == 0)
+ && (!var_ann (decl)
+ || !var_ann (decl)->is_heapvar))
+ push_fields_onto_fieldstack (decl_type, &fieldstack, 0);
/* 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 = new_var_info (decl, index, name);
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->size = vi->fullsize;
}
- insert_id_for_tree (vi->decl, index);
+ insert_vi_for_tree (vi->decl, vi);
VEC_safe_push (varinfo_t, heap, varmap, vi);
- if (is_global && (!flag_whole_program || !in_ipa_mode))
- make_constraint_from_anything (vi);
+ if (is_global && (!flag_whole_program || !in_ipa_mode)
+ && could_have_pointers (decl))
+ {
+ if (var_ann (decl)
+ && var_ann (decl)->noalias_state == NO_ALIAS_ANYTHING)
+ make_constraint_from (vi, vi->id);
+ else
+ make_constraint_from (vi, escaped_id);
+ }
stats.total_vars++;
if (use_field_sensitive
- && !notokay
&& !vi->is_unknown_size_var
&& var_can_have_subvars (decl)
+ && VEC_length (fieldoff_s, fieldstack) > 1
&& VEC_length (fieldoff_s, fieldstack) <= MAX_FIELDS_FOR_FIELD_SENSITIVE)
{
unsigned int newindex = VEC_length (varinfo_t, varmap);
fieldoff_s *fo = NULL;
+ bool notokay = false;
unsigned int i;
for (i = 0; !notokay && VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
{
- if (! fo->size
- || TREE_CODE (fo->size) != INTEGER_CST
+ if (fo->has_unknown_size
|| fo->offset < 0)
{
notokay = true;
vi->is_unknown_size_var = 1;
vi->fullsize = ~0;
vi->size = ~0;
+ vi->is_full_var = true;
VEC_free (fieldoff_s, heap, fieldstack);
return index;
}
- vi->size = TREE_INT_CST_LOW (fo->size);
+ vi->size = fo->size;
vi->offset = fo->offset;
for (i = VEC_length (fieldoff_s, fieldstack) - 1;
i >= 1 && VEC_iterate (fieldoff_s, fieldstack, i, fo);
newindex = VEC_length (varinfo_t, varmap);
if (dump_file)
{
- 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);
+ asprintf (&tempname, "%s." HOST_WIDE_INT_PRINT_DEC
+ "+" HOST_WIDE_INT_PRINT_DEC,
+ vi->name, fo->offset, fo->size);
newname = ggc_strdup (tempname);
free (tempname);
}
- newvi = new_var_info (decl, newindex, newname, newindex);
+ newvi = new_var_info (decl, newindex, newname);
newvi->offset = fo->offset;
- newvi->size = TREE_INT_CST_LOW (fo->size);
+ newvi->size = 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_from_anything (newvi);
+ if (is_global && (!flag_whole_program || !in_ipa_mode)
+ && fo->may_have_pointers)
+ make_constraint_from (newvi, escaped_id);
stats.total_vars++;
}
- VEC_free (fieldoff_s, heap, fieldstack);
}
+ else
+ vi->is_full_var = true;
+
+ VEC_free (fieldoff_s, heap, fieldstack);
+
return index;
}
unsigned int i;
bitmap_iterator bi;
- if (vi->node != var)
+ if (find (var) != var)
{
- varinfo_t vipt = get_varinfo (vi->node);
+ varinfo_t vipt = get_varinfo (find (var));
fprintf (file, "%s = same as %s\n", vi->name, vipt->name);
}
else
{
fprintf (file, "%s = { ", vi->name);
- EXECUTE_IF_SET_IN_BITMAP (get_varinfo (vi->node)->solution, 0, i, bi)
+ EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
{
fprintf (file, "%s ", get_varinfo (i)->name);
}
- fprintf (file, "}\n");
+ fprintf (file, "}");
+ if (vi->no_tbaa_pruning)
+ fprintf (file, " no-tbaa-pruning");
+ fprintf (file, "\n");
}
}
tree t;
struct constraint_expr lhs, rhs;
- /* For each incoming pointer 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 flag_argument_noalias is set. */
for (t = DECL_ARGUMENTS (current_function_decl); t; t = TREE_CHAIN (t))
{
varinfo_t p;
- unsigned int arg_id;
if (!could_have_pointers (t))
continue;
- arg_id = get_id_for_tree (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 flag_argument_noalias is set, then function pointer
+ arguments are guaranteed not to point to each other. In that
+ case, create an artificial variable PARM_NOALIAS and the
+ constraint ARG = &PARM_NOALIAS. */
+ if (POINTER_TYPE_P (TREE_TYPE (t)) && flag_argument_noalias > 0)
{
varinfo_t vi;
tree heapvar = heapvar_lookup (t);
- unsigned int id;
lhs.offset = 0;
lhs.type = SCALAR;
- lhs.var = get_id_for_tree (t);
+ lhs.var = get_vi_for_tree (t)->id;
if (heapvar == NULL_TREE)
{
+ var_ann_t ann;
heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)),
"PARM_NOALIAS");
- get_var_ann (heapvar)->is_heapvar = 1;
DECL_EXTERNAL (heapvar) = 1;
if (gimple_referenced_vars (cfun))
add_referenced_var (heapvar);
+
heapvar_insert (t, heapvar);
+
+ ann = get_var_ann (heapvar);
+ ann->is_heapvar = 1;
+ if (flag_argument_noalias == 1)
+ ann->noalias_state = NO_ALIAS;
+ else if (flag_argument_noalias == 2)
+ ann->noalias_state = NO_ALIAS_GLOBAL;
+ else if (flag_argument_noalias == 3)
+ ann->noalias_state = NO_ALIAS_ANYTHING;
+ else
+ gcc_unreachable ();
}
- id = get_id_for_tree (heapvar);
- vi = get_varinfo (id);
+
+ vi = get_vi_for_tree (heapvar);
vi->is_artificial_var = 1;
vi->is_heap_var = 1;
- rhs.var = id;
- rhs.type = INCLUDES;
+ rhs.var = vi->id;
+ rhs.type = ADDRESSOF;
rhs.offset = 0;
for (p = get_varinfo (lhs.var); p; p = p->next)
{
}
else
{
- for (p = get_varinfo (arg_id); p; p = p->next)
- make_constraint_from_anything (p);
+ varinfo_t arg_vi = get_vi_for_tree (t);
+
+ for (p = arg_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, which came from variable PTR.
For variables that are actually dereferenced, we also use type
- based alias analysis to prune the points-to sets. */
-
-static void
-set_uids_in_ptset (tree ptr, bitmap into, bitmap from)
+ based alias analysis to prune the points-to sets.
+ IS_DEREFED is true if PTR was directly dereferenced, which we use to
+ help determine whether we are we are allowed to prune using TBAA.
+ If NO_TBAA_PRUNING is true, we do not perform any TBAA pruning of
+ the from set. Returns the number of pruned variables. */
+
+static unsigned
+set_uids_in_ptset (tree ptr, bitmap into, bitmap from, bool is_derefed,
+ bool no_tbaa_pruning)
{
unsigned int i;
bitmap_iterator bi;
- subvar_t sv;
- HOST_WIDE_INT ptr_alias_set = get_alias_set (TREE_TYPE (ptr));
+ unsigned pruned = 0;
+
+ gcc_assert (POINTER_TYPE_P (TREE_TYPE (ptr)));
EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
{
varinfo_t vi = get_varinfo (i);
- unsigned HOST_WIDE_INT var_alias_set;
/* The only artificial variables that are allowed in a may-alias
set are heap variables. */
if (vi->is_artificial_var && !vi->is_heap_var)
continue;
- if (vi->has_union && get_subvars_for_var (vi->decl) != NULL)
- {
- /* 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));
- }
- else if (TREE_CODE (vi->decl) == VAR_DECL
- || TREE_CODE (vi->decl) == PARM_DECL)
+ if (TREE_CODE (vi->decl) == VAR_DECL
+ || TREE_CODE (vi->decl) == PARM_DECL
+ || TREE_CODE (vi->decl) == RESULT_DECL)
{
- 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)
- {
- var_alias_set = get_alias_set (sft);
- if (!vi->directly_dereferenced
- || alias_sets_conflict_p (ptr_alias_set, var_alias_set))
- bitmap_set_bit (into, DECL_UID (sft));
- }
- }
+ /* Just add VI->DECL to the alias set.
+ Don't type prune artificial vars or points-to sets
+ for pointers that have not been dereferenced or with
+ type-based pruning disabled. */
+ if (vi->is_artificial_var
+ || !is_derefed
+ || no_tbaa_pruning)
+ bitmap_set_bit (into, DECL_UID (vi->decl));
else
{
- /* Otherwise, just add VI->DECL to the alias set.
- Don't type prune artificial vars. */
- if (vi->is_artificial_var)
- bitmap_set_bit (into, DECL_UID (vi->decl));
+ alias_set_type var_alias_set, mem_alias_set;
+ var_alias_set = get_alias_set (vi->decl);
+ mem_alias_set = get_alias_set (TREE_TYPE (TREE_TYPE (ptr)));
+ if (may_alias_p (SSA_NAME_VAR (ptr), mem_alias_set,
+ vi->decl, var_alias_set, true))
+ bitmap_set_bit (into, DECL_UID (vi->decl));
else
- {
- var_alias_set = get_alias_set (vi->decl);
- if (!vi->directly_dereferenced
- || alias_sets_conflict_p (ptr_alias_set, var_alias_set))
- bitmap_set_bit (into, DECL_UID (vi->decl));
- }
+ ++pruned;
}
}
}
+
+ return pruned;
}
static bool have_alias_info = false;
-/* The list of SMT's that are in use by our pointer variables. This
- is the set of SMT's for all pointers that can point to anything. */
-static bitmap used_smts;
-
-/* Due to the ordering of points-to set calculation and SMT
- calculation being a bit co-dependent, we can't just calculate SMT
- used info whenever we want, we have to calculate it around the time
- that find_what_p_points_to is called. */
+/* Emit a note for the pointer initialization point DEF. */
-/* Mark which SMT's are in use by points-to anything variables. */
-
-void
-set_used_smts (void)
+static void
+emit_pointer_definition (tree ptr, bitmap visited)
{
- int i;
- varinfo_t vi;
- used_smts = BITMAP_ALLOC (&ptabitmap_obstack);
-
- for (i = 0; VEC_iterate (varinfo_t, varmap, i, vi); i++)
+ gimple def = SSA_NAME_DEF_STMT (ptr);
+ if (gimple_code (def) == GIMPLE_PHI)
{
- tree var = vi->decl;
- tree smt;
- bitmap_iterator bi;
- unsigned int j;
- var_ann_t va;
- struct ptr_info_def *pi = NULL;
-
- /* For parm decls, the pointer info may be under the default
- def. */
- if (TREE_CODE (vi->decl) == PARM_DECL
- && gimple_default_def (cfun, var))
- pi = SSA_NAME_PTR_INFO (gimple_default_def (cfun, var));
- else if (TREE_CODE (var) == SSA_NAME)
- pi = SSA_NAME_PTR_INFO (var);
-
- /* Skip the special variables and those without their own
- solution set. */
- if (vi->is_special_var || vi->node != vi->id || !SSA_VAR_P (var)
- || (pi && !pi->is_dereferenced)
- || (TREE_CODE (var) == VAR_DECL && !may_be_aliased (var))
- || !POINTER_TYPE_P (TREE_TYPE (var)))
- continue;
+ use_operand_p argp;
+ ssa_op_iter oi;
- if (TREE_CODE (var) == SSA_NAME)
- var = SSA_NAME_VAR (var);
-
- va = var_ann (var);
- if (!va)
- continue;
-
- smt = va->symbol_mem_tag;
- if (smt && bitmap_bit_p (vi->solution, anything_id))
- bitmap_set_bit (used_smts, DECL_UID (smt));
+ FOR_EACH_PHI_ARG (argp, def, oi, SSA_OP_USE)
+ {
+ tree arg = USE_FROM_PTR (argp);
+ if (TREE_CODE (arg) == SSA_NAME)
+ {
+ if (bitmap_set_bit (visited, SSA_NAME_VERSION (arg)))
+ emit_pointer_definition (arg, visited);
+ }
+ else
+ inform (0, "initialized from %qE", arg);
+ }
}
+ else if (!gimple_nop_p (def))
+ inform (gimple_location (def), "initialized from here");
}
-/* Merge the necessary SMT's into the solution set for VI, which is
- P's varinfo. This involves merging all SMT's that are a subset of
- the SMT necessary for P. */
+/* Emit a strict aliasing warning for dereferencing the pointer PTR. */
static void
-merge_smts_into (tree p, varinfo_t vi)
+emit_alias_warning (tree ptr)
{
- unsigned int i;
- bitmap_iterator bi;
- tree smt;
- VEC(tree, gc) *aliases;
- tree var = p;
+ gimple use;
+ imm_use_iterator ui;
+ unsigned warned = 0;
- if (TREE_CODE (p) == SSA_NAME)
- var = SSA_NAME_VAR (p);
-
- smt = var_ann (var)->symbol_mem_tag;
- if (smt)
+ FOR_EACH_IMM_USE_STMT (use, ui, ptr)
{
- HOST_WIDE_INT smtset = get_alias_set (TREE_TYPE (smt));
+ tree deref = NULL_TREE;
- /* Need to set the SMT subsets first before this
- will work properly. */
- bitmap_set_bit (vi->finished_solution, DECL_UID (smt));
- EXECUTE_IF_SET_IN_BITMAP (used_smts, 0, i, bi)
+ if (gimple_has_lhs (use))
{
- tree newsmt = referenced_var (i);
- tree newsmttype = TREE_TYPE (newsmt);
-
- if (alias_set_subset_of (get_alias_set (newsmttype),
- smtset))
- bitmap_set_bit (vi->finished_solution, i);
+ tree lhs = get_base_address (gimple_get_lhs (use));
+ if (lhs
+ && INDIRECT_REF_P (lhs)
+ && TREE_OPERAND (lhs, 0) == ptr)
+ deref = lhs;
}
-
- aliases = var_ann (smt)->may_aliases;
- if (aliases)
+ if (gimple_assign_single_p (use))
+ {
+ tree rhs = get_base_address (gimple_assign_rhs1 (use));
+ if (rhs
+ && INDIRECT_REF_P (rhs)
+ && TREE_OPERAND (rhs, 0) == ptr)
+ deref = rhs;
+ }
+ else if (is_gimple_call (use))
+ {
+ unsigned i;
+ for (i = 0; i < gimple_call_num_args (use); ++i)
+ {
+ tree op = get_base_address (gimple_call_arg (use, i));
+ if (op
+ && INDIRECT_REF_P (op)
+ && TREE_OPERAND (op, 0) == ptr)
+ deref = op;
+ }
+ }
+ if (deref
+ && !TREE_NO_WARNING (deref))
{
- size_t k;
- tree al;
- for (k = 0; VEC_iterate (tree, aliases, k, al); k++)
- bitmap_set_bit (vi->finished_solution,
- DECL_UID (al));
+ TREE_NO_WARNING (deref) = 1;
+ warning_at (gimple_location (use), OPT_Wstrict_aliasing,
+ "dereferencing pointer %qD does break strict-aliasing "
+ "rules", SSA_NAME_VAR (ptr));
+ ++warned;
}
}
+ if (warned > 0)
+ {
+ bitmap visited = BITMAP_ALLOC (NULL);
+ emit_pointer_definition (ptr, visited);
+ BITMAP_FREE (visited);
+ }
}
/* Given a pointer variable P, fill in its points-to set, or return
- false if we can't.
+ false if we can't.
Rather than return false for variables that point-to anything, we
- instead find the corresponding SMT, and merge in it's aliases. In
+ instead find the corresponding SMT, and merge in its aliases. In
addition to these aliases, we also set the bits for the SMT's
themselves and their subsets, as SMT's are still in use by
non-SSA_NAME's, and pruning may eliminate every one of their
bool
find_what_p_points_to (tree p)
{
- unsigned int id = 0;
tree lookup_p = p;
+ varinfo_t vi;
if (!have_alias_info)
return false;
decl. */
if (TREE_CODE (p) == SSA_NAME
&& TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL
- && gimple_default_def (cfun, SSA_NAME_VAR (p)) == p)
+ && SSA_NAME_IS_DEFAULT_DEF (p))
lookup_p = SSA_NAME_VAR (p);
- if (lookup_id_for_tree (lookup_p, &id))
+ vi = lookup_vi_for_tree (lookup_p);
+ if (vi)
{
- varinfo_t vi = get_varinfo (id);
-
if (vi->is_artificial_var)
return false;
/* 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;
+ return false;
}
else
{
struct ptr_info_def *pi = get_ptr_info (p);
- unsigned int i;
+ unsigned int i, pruned;
bitmap_iterator bi;
bool was_pt_anything = false;
+ bitmap finished_solution;
+ bitmap result;
- if (!pi->is_dereferenced)
+ if (!pi->memory_tag_needed)
return false;
/* This variable may have been collapsed, let's get the real
variable. */
- vi = get_varinfo (vi->node);
+ vi = get_varinfo (find (vi->id));
/* Translate artificial variables into SSA_NAME_PTR_INFO
attributes. */
aliases. */
if (vi->id == nothing_id)
pi->pt_null = 1;
- else if (vi->id == anything_id)
+ else if (vi->id == anything_id
+ || vi->id == nonlocal_id
+ || vi->id == escaped_id
+ || vi->id == callused_id)
was_pt_anything = 1;
else if (vi->id == readonly_id)
was_pt_anything = 1;
}
}
- /* Share the final set of variables between the SSA_NAME
- pointer infos for collapsed nodes that are collapsed to
- non-special variables. This is because special vars have
- no real types associated with them, so while we know the
- pointers are equivalent to them, we need to generate the
- solution separately since it will include SMT's from the
- original non-collapsed variable. */
- if (!vi->is_special_var && vi->finished_solution)
+ /* Instead of doing extra work, simply do not create
+ points-to information for pt_anything pointers. This
+ will cause the operand scanner to fall back to the
+ type-based SMT and its aliases. Which is the best
+ we could do here for the points-to set as well. */
+ if (was_pt_anything)
+ return false;
+
+ /* Share the final set of variables when possible. */
+ finished_solution = BITMAP_GGC_ALLOC ();
+ stats.points_to_sets_created++;
+
+ pruned = set_uids_in_ptset (p, finished_solution, vi->solution,
+ pi->is_dereferenced,
+ vi->no_tbaa_pruning);
+ result = shared_bitmap_lookup (finished_solution);
+
+ if (!result)
{
- pi->pt_vars = vi->finished_solution;
+ shared_bitmap_add (finished_solution);
+ pi->pt_vars = finished_solution;
}
else
{
- vi->finished_solution = BITMAP_GGC_ALLOC ();
+ pi->pt_vars = result;
+ bitmap_clear (finished_solution);
+ }
- /* Instead of using pt_anything, we instead merge in the SMT
- aliases for the underlying SMT. */
- if (was_pt_anything)
+ if (bitmap_empty_p (pi->pt_vars))
+ {
+ pi->pt_vars = NULL;
+ if (pruned > 0
+ && pi->is_dereferenced
+ && warn_strict_aliasing > 0
+ && !SSA_NAME_IS_DEFAULT_DEF (p))
{
- merge_smts_into (p, vi);
- pi->pt_global_mem = 1;
+ if (dump_file && dump_flags & TDF_DETAILS)
+ {
+ fprintf (dump_file, "alias warning for ");
+ print_generic_expr (dump_file, p, 0);
+ fprintf (dump_file, "\n");
+ }
+ emit_alias_warning (p);
}
-
- set_uids_in_ptset (vi->decl, vi->finished_solution, vi->solution);
- pi->pt_vars = vi->finished_solution;
}
- if (bitmap_empty_p (pi->pt_vars))
- pi->pt_vars = NULL;
-
return true;
}
}
return false;
}
+/* Mark the ESCAPED solution as call clobbered. Returns false if
+ pt_anything escaped which needs all locals that have their address
+ taken marked call clobbered as well. */
+
+bool
+clobber_what_escaped (void)
+{
+ varinfo_t vi;
+ unsigned int i;
+ bitmap_iterator bi;
+
+ if (!have_alias_info)
+ return false;
+
+ /* This variable may have been collapsed, let's get the real
+ variable for escaped_id. */
+ vi = get_varinfo (find (escaped_id));
+
+ /* If call-used memory escapes we need to include it in the
+ set of escaped variables. This can happen if a pure
+ function returns a pointer and this pointer escapes. */
+ if (bitmap_bit_p (vi->solution, callused_id))
+ {
+ varinfo_t cu_vi = get_varinfo (find (callused_id));
+ bitmap_ior_into (vi->solution, cu_vi->solution);
+ }
+
+ /* Mark variables in the solution call-clobbered. */
+ EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
+ {
+ varinfo_t vi = get_varinfo (i);
+
+ if (vi->is_artificial_var)
+ {
+ /* nothing_id and readonly_id do not cause any
+ call clobber ops. For anything_id and integer_id
+ we need to clobber all addressable vars. */
+ if (vi->id == anything_id
+ || vi->id == integer_id)
+ return false;
+ }
+
+ /* Only artificial heap-vars are further interesting. */
+ if (vi->is_artificial_var && !vi->is_heap_var)
+ continue;
+
+ if ((TREE_CODE (vi->decl) == VAR_DECL
+ || TREE_CODE (vi->decl) == PARM_DECL
+ || TREE_CODE (vi->decl) == RESULT_DECL)
+ && !unmodifiable_var_p (vi->decl))
+ mark_call_clobbered (vi->decl, ESCAPE_TO_CALL);
+ }
+
+ return true;
+}
+
+/* Compute the call-used variables. */
+
+void
+compute_call_used_vars (void)
+{
+ varinfo_t vi;
+ unsigned int i;
+ bitmap_iterator bi;
+ bool has_anything_id = false;
+
+ if (!have_alias_info)
+ return;
+
+ /* This variable may have been collapsed, let's get the real
+ variable for escaped_id. */
+ vi = get_varinfo (find (callused_id));
+
+ /* Mark variables in the solution call-clobbered. */
+ EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
+ {
+ varinfo_t vi = get_varinfo (i);
+
+ if (vi->is_artificial_var)
+ {
+ /* For anything_id and integer_id we need to make
+ all local addressable vars call-used. */
+ if (vi->id == anything_id
+ || vi->id == integer_id)
+ has_anything_id = true;
+ }
+
+ /* Only artificial heap-vars are further interesting. */
+ if (vi->is_artificial_var && !vi->is_heap_var)
+ continue;
+
+ if ((TREE_CODE (vi->decl) == VAR_DECL
+ || TREE_CODE (vi->decl) == PARM_DECL
+ || TREE_CODE (vi->decl) == RESULT_DECL)
+ && !unmodifiable_var_p (vi->decl))
+ bitmap_set_bit (gimple_call_used_vars (cfun), DECL_UID (vi->decl));
+ }
+
+ /* If anything is call-used, add all addressable locals to the set. */
+ if (has_anything_id)
+ bitmap_ior_into (gimple_call_used_vars (cfun),
+ gimple_addressable_vars (cfun));
+}
/* Dump points-to information to OUTFILE. */
{
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++)
/* 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 (nothing_tree, nothing_id, "NULL");
+ insert_vi_for_tree (nothing_tree, var_nothing);
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);
/* 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 (anything_tree, anything_id, "ANYTHING");
+ insert_vi_for_tree (anything_tree, var_anything);
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,
lhs.type = SCALAR;
lhs.var = anything_id;
lhs.offset = 0;
- rhs.type = INCLUDES;
+ 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
/* 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 (readonly_tree, readonly_id, "READONLY");
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;
+ insert_vi_for_tree (readonly_tree, var_readonly);
VEC_safe_push (varinfo_t, heap, varmap, var_readonly);
/* readonly memory points to anything, in order to make deref
lhs.type = SCALAR;
lhs.var = readonly_id;
lhs.offset = 0;
- rhs.type = INCLUDES;
- rhs.var = anything_id;
+ rhs.type = ADDRESSOF;
+ rhs.var = readonly_id; /* FIXME */
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+
+ /* Create the ESCAPED variable, used to represent the set of escaped
+ memory. */
+ escaped_tree = create_tmp_var_raw (void_type_node, "ESCAPED");
+ var_escaped = new_var_info (escaped_tree, escaped_id, "ESCAPED");
+ insert_vi_for_tree (escaped_tree, var_escaped);
+ var_escaped->is_artificial_var = 1;
+ var_escaped->offset = 0;
+ var_escaped->size = ~0;
+ var_escaped->fullsize = ~0;
+ var_escaped->is_special_var = 0;
+ VEC_safe_push (varinfo_t, heap, varmap, var_escaped);
+ gcc_assert (VEC_index (varinfo_t, varmap, 3) == var_escaped);
+
+ /* 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));
+
+ /* Create the NONLOCAL variable, used to represent the set of nonlocal
+ memory. */
+ nonlocal_tree = create_tmp_var_raw (void_type_node, "NONLOCAL");
+ var_nonlocal = new_var_info (nonlocal_tree, nonlocal_id, "NONLOCAL");
+ insert_vi_for_tree (nonlocal_tree, var_nonlocal);
+ var_nonlocal->is_artificial_var = 1;
+ var_nonlocal->offset = 0;
+ var_nonlocal->size = ~0;
+ var_nonlocal->fullsize = ~0;
+ var_nonlocal->is_special_var = 1;
+ VEC_safe_push (varinfo_t, heap, varmap, var_nonlocal);
+
+ /* Nonlocal memory points to escaped (which includes nonlocal),
+ in order to make deref easier. */
+ lhs.type = SCALAR;
+ lhs.var = nonlocal_id;
+ lhs.offset = 0;
+ rhs.type = ADDRESSOF;
+ rhs.var = escaped_id;
rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+ /* Create the CALLUSED variable, used to represent the set of call-used
+ memory. */
+ callused_tree = create_tmp_var_raw (void_type_node, "CALLUSED");
+ var_callused = new_var_info (callused_tree, callused_id, "CALLUSED");
+ insert_vi_for_tree (callused_tree, var_callused);
+ var_callused->is_artificial_var = 1;
+ var_callused->offset = 0;
+ var_callused->size = ~0;
+ var_callused->fullsize = ~0;
+ var_callused->is_special_var = 0;
+ VEC_safe_push (varinfo_t, heap, varmap, var_callused);
+
+ /* CALLUSED = *CALLUSED, because call-used is may-deref'd at calls, etc. */
+ lhs.type = SCALAR;
+ lhs.var = callused_id;
+ lhs.offset = 0;
+ rhs.type = DEREF;
+ rhs.var = callused_id;
+ rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
/* 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);
+ var_integer = new_var_info (integer_tree, integer_id, "INTEGER");
+ insert_vi_for_tree (integer_tree, var_integer);
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
lhs.type = SCALAR;
lhs.var = integer_id;
lhs.offset = 0;
- rhs.type = INCLUDES;
+ rhs.type = ADDRESSOF;
rhs.var = anything_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
+
+ /* *ESCAPED = &ESCAPED. This is true because we have to assume
+ everything pointed to by escaped can also point to escaped. */
+ lhs.type = DEREF;
+ lhs.var = escaped_id;
+ lhs.offset = 0;
+ rhs.type = ADDRESSOF;
+ rhs.var = escaped_id;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+
+ /* *ESCAPED = &NONLOCAL. This is true because we have to assume
+ everything pointed to by escaped can also point to nonlocal. */
+ lhs.type = DEREF;
+ lhs.var = escaped_id;
+ lhs.offset = 0;
+ rhs.type = ADDRESSOF;
+ rhs.var = nonlocal_id;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
}
/* 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",
sizeof (struct variable_info), 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 ();
+ 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);
+}
+
+/* Compute the set of variables we can't TBAA prune. */
+
+static void
+compute_tbaa_pruning (void)
+{
+ unsigned int size = VEC_length (varinfo_t, varmap);
+ unsigned int i;
+ bool any;
+
+ changed_count = 0;
+ changed = sbitmap_alloc (size);
+ sbitmap_zero (changed);
+
+ /* Mark all initial no_tbaa_pruning nodes as changed. */
+ any = false;
+ for (i = 0; i < size; ++i)
+ {
+ varinfo_t ivi = get_varinfo (i);
+
+ if (find (i) == i && ivi->no_tbaa_pruning)
+ {
+ any = true;
+ if ((graph->succs[i] && !bitmap_empty_p (graph->succs[i]))
+ || VEC_length (constraint_t, graph->complex[i]) > 0)
+ {
+ SET_BIT (changed, i);
+ ++changed_count;
+ }
+ }
+ }
+
+ while (changed_count > 0)
+ {
+ struct topo_info *ti = init_topo_info ();
+ ++stats.iterations;
+
+ compute_topo_order (graph, ti);
+
+ while (VEC_length (unsigned, ti->topo_order) != 0)
+ {
+ bitmap_iterator bi;
+
+ i = VEC_pop (unsigned, ti->topo_order);
+
+ /* If this variable is not a representative, skip it. */
+ if (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;
+ VEC(constraint_t,heap) *complex = graph->complex[i];
+
+ RESET_BIT (changed, i);
+ --changed_count;
+
+ /* Process the complex copy constraints. */
+ for (j = 0; VEC_iterate (constraint_t, complex, j, c); ++j)
+ {
+ if (c->lhs.type == SCALAR && c->rhs.type == SCALAR)
+ {
+ varinfo_t lhsvi = get_varinfo (find (c->lhs.var));
+
+ if (!lhsvi->no_tbaa_pruning)
+ {
+ lhsvi->no_tbaa_pruning = true;
+ if (!TEST_BIT (changed, lhsvi->id))
+ {
+ SET_BIT (changed, lhsvi->id);
+ ++changed_count;
+ }
+ }
+ }
+ }
+
+ /* Propagate to all successors. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i], 0, j, bi)
+ {
+ unsigned int to = find (j);
+ varinfo_t tovi = get_varinfo (to);
+
+ /* Don't propagate to ourselves. */
+ if (to == i)
+ continue;
+
+ if (!tovi->no_tbaa_pruning)
+ {
+ tovi->no_tbaa_pruning = true;
+ if (!TEST_BIT (changed, to))
+ {
+ SET_BIT (changed, to);
+ ++changed_count;
+ }
+ }
+ }
+ }
+ }
+
+ free_topo_info (ti);
+ }
+
+ sbitmap_free (changed);
+
+ if (any)
+ {
+ for (i = 0; i < size; ++i)
+ {
+ varinfo_t ivi = get_varinfo (i);
+ varinfo_t ivip = get_varinfo (find (i));
+
+ if (ivip->no_tbaa_pruning)
+ {
+ tree var = ivi->decl;
+
+ if (TREE_CODE (var) == SSA_NAME)
+ var = SSA_NAME_VAR (var);
+
+ if (POINTER_TYPE_P (TREE_TYPE (var)))
+ {
+ DECL_NO_TBAA_P (var) = 1;
+
+ /* Tell the RTL layer that this pointer can alias
+ anything. */
+ DECL_POINTER_ALIAS_SET (var) = 0;
+ }
+ }
+ }
+ }
+}
+
/* 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)
+compute_points_to_sets (void)
{
+ struct scc_info *si;
basic_block bb;
timevar_push (TV_TREE_PTA);
init_alias_vars ();
+ init_alias_heapvars ();
intra_create_variable_infos ();
/* Now walk all statements and derive aliases. */
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); )
{
- 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);
+
+ /* The information in GIMPLE_CHANGE_DYNAMIC_TYPE statements
+ has now been captured, and we can remove them. */
+ if (gimple_code (stmt) == GIMPLE_CHANGE_DYNAMIC_TYPE)
+ gsi_remove (&gsi, true);
+ else
+ gsi_next (&gsi);
}
}
- build_constraint_graph ();
if (dump_file)
{
if (dump_file)
fprintf (dump_file,
"\nCollapsing static cycles and doing variable "
- "substitution:\n");
+ "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);
+ free_var_substitution_info (si);
+
+ build_succ_graph ();
+
+ 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);
- find_and_collapse_graph_cycles (graph, false);
- perform_var_substitution (graph);
+ /* Implicit nodes and predecessors are no longer necessary at this
+ point. */
+ remove_preds_and_fake_succs (graph);
if (dump_file)
- fprintf (dump_file, "\nSolving graph:\n");
+ fprintf (dump_file, "Solving graph\n");
solve_graph (graph);
+ compute_tbaa_pruning ();
+
if (dump_file)
dump_sa_points_to_info (dump_file);
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);
+ 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_t, heap, v->complex);
+ for (i = 0; i < graph->size; i++)
+ VEC_free (constraint_t, heap, graph->complex[i]);
+ free (graph->complex);
- free (graph->preds);
+ free (graph->rep);
free (graph->succs);
+ free (graph->pe);
+ free (graph->pe_rep);
+ free (graph->indirect_cycles);
free (graph);
VEC_free (varinfo_t, heap, varmap);
static bool
gate_ipa_pta (void)
{
- return (flag_unit_at_a_time != 0
- && flag_ipa_pta
+ return (flag_ipa_pta
/* Don't bother doing anything if the program has errors. */
&& !(errorcount || sorrycount));
}
ipa_pta_execute (void)
{
struct cgraph_node *node;
+ struct scc_info *si;
+
in_ipa_mode = 1;
init_alias_heapvars ();
init_alias_vars ();
{
varinfo_t fi = get_varinfo (varid);
for (; fi; fi = fi->next)
- make_constraint_from_anything (fi);
+ make_constraint_from (fi, anything_id);
}
}
}
{
if (node->analyzed && cgraph_is_master_clone (node))
{
- struct function *cfun = DECL_STRUCT_FUNCTION (node->decl);
+ struct function *func = 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);
+ push_cfun (func);
current_function_decl = node->decl;
- FOR_EACH_BB_FN (bb, cfun)
+ FOR_EACH_BB_FN (bb, func)
{
- 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);
- }
- }
+ gimple phi = gsi_stmt (gsi);
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- {
- tree stmt = bsi_stmt (bsi);
- find_func_aliases (stmt);
+ 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))
+ find_func_aliases (gsi_stmt (gsi));
}
current_function_decl = old_func_decl;
pop_cfun ();
}
}
- build_constraint_graph ();
-
if (dump_file)
{
fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
"\nCollapsing static cycles and doing variable "
"substitution:\n");
- find_and_collapse_graph_cycles (graph, false);
- perform_var_substitution (graph);
+ init_graph (VEC_length (varinfo_t, varmap) * 2);
+ build_pred_graph ();
+ si = perform_var_substitution (graph);
+ rewrite_constraints (graph, si);
+ free_var_substitution_info (si);
+
+ build_succ_graph ();
+ move_complex_constraints (graph);
+ unite_pointer_equivalences (graph);
+ 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, "\nSolving graph:\n");
+ fprintf (dump_file, "\nSolving graph\n");
solve_graph (graph);
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);
+ if (!heapvar_for_stmt)
+ heapvar_for_stmt = htab_create_ggc (11, tree_map_hash, tree_map_eq,
+ NULL);
}
void
delete_alias_heapvars (void)
{
htab_delete (heapvar_for_stmt);
+ heapvar_for_stmt = NULL;
}
-
#include "gt-tree-ssa-structalias.h"
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