/* Tree based points-to analysis
- Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
Contributed by Daniel Berlin <dberlin@dberlin.org>
-This file is part of GCC.
+ This file is part of GCC.
-GCC is free software; you can redistribute it and/or modify
-under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
+ GCC is free software; you can redistribute it and/or modify
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
-GCC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+ GCC is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
-You should have received a copy of the GNU General Public License
-along with GCC; if not, write to the Free Software
-Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
-*/
+ You should have received a copy of the GNU General Public License
+ along with GCC; see the file COPYING3. If not see
+ <http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "output.h"
-#include "errors.h"
-#include "diagnostic.h"
#include "tree.h"
-#include "c-common.h"
#include "tree-flow.h"
#include "tree-inline.h"
#include "varray.h"
-#include "c-tree.h"
-#include "tree-gimple.h"
+#include "diagnostic.h"
+#include "toplev.h"
+#include "gimple.h"
#include "hashtab.h"
#include "function.h"
#include "cgraph.h"
#include "alloc-pool.h"
#include "splay-tree.h"
#include "params.h"
-#include "tree-ssa-structalias.h"
#include "cgraph.h"
#include "alias.h"
#include "pointer-set.h"
typedef struct constraint_graph *constraint_graph_t;
static void unify_nodes (constraint_graph_t, unsigned int, unsigned int, bool);
+struct constraint;
+typedef struct constraint *constraint_t;
+
DEF_VEC_P(constraint_t);
DEF_VEC_ALLOC_P(constraint_t,heap);
/* 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;
-
- /* 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. */
- 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;
variable. This is used for C++ placement new. */
unsigned int no_tbaa_pruning : 1;
+ /* True if this field may contain pointers. */
+ unsigned int may_have_pointers : 1;
+
+ /* A link to the variable for the next field in this structure. */
+ struct variable_info *next;
+
+ /* Offset of this variable, in bits, from the base variable */
+ unsigned HOST_WIDE_INT offset;
+
+ /* Size of the variable, in bits. */
+ unsigned HOST_WIDE_INT size;
+
+ /* Full size of the base variable, in bits. */
+ unsigned HOST_WIDE_INT fullsize;
+
+ /* Name of this variable */
+ const char *name;
+
+ /* Tree that this variable is associated with. */
+ tree decl;
+
/* Points-to set for this variable. */
bitmap solution;
/* Old points-to set for this variable. */
bitmap oldsolution;
-
- /* Variable ids represented by this node. */
- bitmap variables;
-
- /* Variable id this was collapsed to due to type unsafety. This
- should be unused completely after build_succ_graph, or something
- is broken. */
- struct variable_info *collapsed_to;
};
typedef struct variable_info *varinfo_t;
static varinfo_t first_vi_for_offset (varinfo_t, unsigned HOST_WIDE_INT);
+static varinfo_t first_or_preceding_vi_for_offset (varinfo_t,
+ unsigned HOST_WIDE_INT);
+static varinfo_t lookup_vi_for_tree (tree);
/* Pool of variable info structures. */
static alloc_pool variable_info_pool;
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);
-
- if (v->collapsed_to)
- return 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,
+ storedanything_id = 6, integer_id = 7 };
/* 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 variables that are stored to anything. */
+static varinfo_t var_storedanything;
+static tree storedanything_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. */
ret->id = id;
ret->name = name;
ret->decl = t;
- 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->is_full_var = false;
+ ret->may_have_pointers = true;
var = t;
if (TREE_CODE (var) == SSA_NAME)
var = SSA_NAME_VAR (var);
ret->solution = BITMAP_ALLOC (&pta_obstack);
ret->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
ret->next = NULL;
- ret->collapsed_to = NULL;
return ret;
}
IOW, in a deref constraint, we would deref, get the result set,
then add OFFSET to each member. */
- unsigned HOST_WIDE_INT offset;
+ HOST_WIDE_INT offset;
};
+/* Use 0x8000... as special unknown offset. */
+#define UNKNOWN_OFFSET ((HOST_WIDE_INT)-1 << (HOST_BITS_PER_WIDE_INT-1))
+
typedef struct constraint_expr ce_s;
DEF_VEC_O(ce_s);
DEF_VEC_ALLOC_O(ce_s, heap);
+static void get_constraint_for_1 (tree, VEC(ce_s, heap) **, bool);
static void get_constraint_for (tree, VEC(ce_s, heap) **);
static void do_deref (VEC (ce_s, heap) **);
been unified. */
unsigned int *rep;
- /* Equivalence class representative for a node. This is used for
+ /* Equivalence class representative for a label. This is used for
variable substitution. */
int *eq_rep;
- /* Label for each node, used during variable substitution. */
- unsigned int *label;
+ /* 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. */
end. */
#define FIRST_REF_NODE (VEC_length (varinfo_t, varmap))
#define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
-#define FIRST_ADDR_NODE (LAST_REF_NODE + 1)
/* Return the representative node for NODE, if NODE has been unioned
with another NODE.
/* Print out constraint C to FILE. */
-void
+static void
dump_constraint (FILE *file, constraint_t c)
{
if (c->lhs.type == ADDRESSOF)
fprintf (file, "&");
else if (c->lhs.type == DEREF)
fprintf (file, "*");
- fprintf (file, "%s", get_varinfo_fc (c->lhs.var)->name);
- if (c->lhs.offset != 0)
+ fprintf (file, "%s", get_varinfo (c->lhs.var)->name);
+ if (c->lhs.offset == UNKNOWN_OFFSET)
+ fprintf (file, " + UNKNOWN");
+ else if (c->lhs.offset != 0)
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->lhs.offset);
fprintf (file, " = ");
if (c->rhs.type == ADDRESSOF)
fprintf (file, "&");
else if (c->rhs.type == DEREF)
fprintf (file, "*");
- fprintf (file, "%s", get_varinfo_fc (c->rhs.var)->name);
- if (c->rhs.offset != 0)
+ fprintf (file, "%s", get_varinfo (c->rhs.var)->name);
+ if (c->rhs.offset == UNKNOWN_OFFSET)
+ fprintf (file, " + UNKNOWN");
+ else if (c->rhs.offset != 0)
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->rhs.offset);
fprintf (file, "\n");
}
+
+void debug_constraint (constraint_t);
+void debug_constraints (void);
+void debug_constraint_graph (void);
+void debug_solution_for_var (unsigned int);
+void debug_sa_points_to_info (void);
+
/* Print out constraint C to stderr. */
void
/* Print out all constraints to FILE */
-void
+static void
dump_constraints (FILE *file)
{
int i;
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. */
+
+static void
+dump_constraint_edge (FILE *file, constraint_t c)
+{
+ if (c->rhs.type != ADDRESSOF)
+ {
+ const char *src = get_varinfo (c->rhs.var)->name;
+ const char *dst = get_varinfo (c->lhs.var)->name;
+ fprintf (file, " \"%s\" -> \"%s\" ", src, dst);
+ /* Due to preprocessing of constraints, instructions like *a = *b are
+ illegal; thus, we do not have to handle such cases. */
+ if (c->lhs.type == DEREF)
+ fprintf (file, " [ label=\"*=\" ] ;\n");
+ else if (c->rhs.type == DEREF)
+ fprintf (file, " [ label=\"=*\" ] ;\n");
+ else
+ {
+ /* We must check the case where the constraint is an offset.
+ In this case, it is treated as a complex constraint. */
+ if (c->rhs.offset != c->lhs.offset)
+ fprintf (file, " [ label=\"+\" ] ;\n");
+ else
+ fprintf (file, " ;\n");
+ }
+ }
+}
+
+/* Print the constraint graph in dot format. */
+
+static void
+dump_constraint_graph (FILE *file)
+{
+ unsigned int i=0, size;
+ constraint_t c;
+
+ /* Only print the graph if it has already been initialized: */
+ if (!graph)
+ return;
+
+ /* Print the constraints used to produce the constraint graph. The
+ constraints will be printed as comments in the dot file: */
+ fprintf (file, "\n\n/* Constraints used in the constraint graph:\n");
+ dump_constraints (file);
+ fprintf (file, "*/\n");
+
+ /* Prints the header of the dot file: */
+ fprintf (file, "\n\n// The constraint graph in dot format:\n");
+ fprintf (file, "strict digraph {\n");
+ fprintf (file, " node [\n shape = box\n ]\n");
+ fprintf (file, " edge [\n fontsize = \"12\"\n ]\n");
+ fprintf (file, "\n // List of nodes in the constraint graph:\n");
+
+ /* The next lines print the nodes in the graph. In order to get the
+ number of nodes in the graph, we must choose the minimum between the
+ vector VEC (varinfo_t, varmap) and graph->size. If the graph has not
+ yet been initialized, then graph->size == 0, otherwise we must only
+ read nodes that have an entry in VEC (varinfo_t, varmap). */
+ size = VEC_length (varinfo_t, varmap);
+ size = size < graph->size ? size : graph->size;
+ for (i = 0; i < size; i++)
+ {
+ const char *name = get_varinfo (graph->rep[i])->name;
+ fprintf (file, " \"%s\" ;\n", name);
+ }
+
+ /* Go over the list of constraints printing the edges in the constraint
+ graph. */
+ fprintf (file, "\n // The constraint edges:\n");
+ for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
+ if (c)
+ dump_constraint_edge (file, c);
+
+ /* Prints the tail of the dot file. By now, only the closing bracket. */
+ fprintf (file, "}\n\n\n");
+}
+
+/* Print out the constraint graph to stderr. */
+
+void
+debug_constraint_graph (void)
+{
+ dump_constraint_graph (stderr);
+}
+
/* SOLVER FUNCTIONS
The solver is a simple worklist solver, that works on the following
}
}
+/* Expands the solution in SET to all sub-fields of variables included.
+ Union the expanded result into RESULT. */
+
+static void
+solution_set_expand (bitmap result, bitmap set)
+{
+ bitmap_iterator bi;
+ bitmap vars = NULL;
+ unsigned j;
+
+ /* In a first pass record all variables we need to add all
+ sub-fields off. This avoids quadratic behavior. */
+ EXECUTE_IF_SET_IN_BITMAP (set, 0, j, bi)
+ {
+ varinfo_t v = get_varinfo (j);
+ if (v->is_artificial_var
+ || v->is_full_var)
+ continue;
+ v = lookup_vi_for_tree (v->decl);
+ if (vars == NULL)
+ vars = BITMAP_ALLOC (NULL);
+ bitmap_set_bit (vars, v->id);
+ }
+
+ /* In the second pass now do the addition to the solution and
+ to speed up solving add it to the delta as well. */
+ if (vars != NULL)
+ {
+ EXECUTE_IF_SET_IN_BITMAP (vars, 0, j, bi)
+ {
+ varinfo_t v = get_varinfo (j);
+ for (; v != NULL; v = v->next)
+ bitmap_set_bit (result, v->id);
+ }
+ BITMAP_FREE (vars);
+ }
+}
+
/* Take a solution set SET, add OFFSET to each member of the set, and
overwrite SET with the result when done. */
static void
-solution_set_add (bitmap set, unsigned HOST_WIDE_INT offset)
+solution_set_add (bitmap set, HOST_WIDE_INT offset)
{
bitmap result = BITMAP_ALLOC (&iteration_obstack);
unsigned int i;
bitmap_iterator bi;
+ /* If the offset is unknown we have to expand the solution to
+ all subfields. */
+ if (offset == UNKNOWN_OFFSET)
+ {
+ solution_set_expand (set, set);
+ return;
+ }
+
EXECUTE_IF_SET_IN_BITMAP (set, 0, i, bi)
{
- /* If this is a properly sized variable, only add offset if it's
- less than end. Otherwise, it is globbed to a single
- variable. */
+ varinfo_t vi = get_varinfo (i);
- if ((get_varinfo (i)->offset + offset) < get_varinfo (i)->fullsize)
- {
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (i)->offset + offset;
- varinfo_t v = first_vi_for_offset (get_varinfo (i), fieldoffset);
- if (!v)
- continue;
- bitmap_set_bit (result, v->id);
- }
- else if (get_varinfo (i)->is_artificial_var
- || get_varinfo (i)->has_union
- || get_varinfo (i)->is_unknown_size_var)
+ /* If this is a variable with just one field just set its bit
+ in the result. */
+ if (vi->is_artificial_var
+ || vi->is_unknown_size_var
+ || vi->is_full_var)
+ bitmap_set_bit (result, i);
+ else
{
- bitmap_set_bit (result, i);
+ unsigned HOST_WIDE_INT fieldoffset = vi->offset + offset;
+
+ /* If the offset makes the pointer point to before the
+ variable use offset zero for the field lookup. */
+ if (offset < 0
+ && fieldoffset > vi->offset)
+ fieldoffset = 0;
+
+ if (offset != 0)
+ vi = first_or_preceding_vi_for_offset (vi, fieldoffset);
+
+ bitmap_set_bit (result, vi->id);
+ /* If the result is not exactly at fieldoffset include the next
+ field as well. See get_constraint_for_ptr_offset for more
+ rationale. */
+ if (vi->offset != fieldoffset
+ && vi->next != NULL)
+ bitmap_set_bit (result, vi->next->id);
}
}
process. */
static bool
-set_union_with_increment (bitmap to, bitmap from, unsigned HOST_WIDE_INT inc)
+set_union_with_increment (bitmap to, bitmap from, HOST_WIDE_INT inc)
{
if (inc == 0)
return bitmap_ior_into (to, from);
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];
- }
- else
- {
- unsigned int tonode = find (graph->indirect_cycles[to]);
- unsigned int fromnode = find (graph->indirect_cycles[from]);
-
- if (unite (tonode, fromnode))
- unify_nodes (graph, tonode, fromnode, true);
- }
+ graph->indirect_cycles[to] = graph->indirect_cycles[from];
}
/* Merge all the successor edges. */
if (!graph->implicit_preds[to])
graph->implicit_preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
- if (!bitmap_bit_p (graph->implicit_preds[to], from))
- {
- stats.num_implicit_edges++;
- bitmap_set_bit (graph->implicit_preds[to], from);
- }
+ 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
{
if (!graph->preds[to])
graph->preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
- if (!bitmap_bit_p (graph->preds[to], from))
- bitmap_set_bit (graph->preds[to], from);
+ bitmap_set_bit (graph->preds[to], from);
}
/* Add a graph edge to GRAPH, going from FROM to TO if
if (!graph->succs[from])
graph->succs[from] = BITMAP_ALLOC (&pta_obstack);
- if (!bitmap_bit_p (graph->succs[from], to))
+ if (bitmap_set_bit (graph->succs[from], to))
{
r = true;
if (to < FIRST_REF_NODE && from < FIRST_REF_NODE)
stats.num_edges++;
- bitmap_set_bit (graph->succs[from], to);
}
return r;
}
&& bitmap_bit_p (graph->succs[dest], src));
}
+/* Initialize the constraint graph structure to contain SIZE nodes. */
+
+static void
+init_graph (unsigned int size)
+{
+ unsigned int j;
+
+ graph = XCNEW (struct constraint_graph);
+ graph->size = size;
+ graph->succs = XCNEWVEC (bitmap, graph->size);
+ graph->indirect_cycles = XNEWVEC (int, graph->size);
+ graph->rep = XNEWVEC (unsigned int, graph->size);
+ graph->complex = XCNEWVEC (VEC(constraint_t, heap) *, size);
+ graph->pe = XCNEWVEC (unsigned int, graph->size);
+ graph->pe_rep = XNEWVEC (int, graph->size);
+
+ for (j = 0; j < graph->size; j++)
+ {
+ graph->rep[j] = j;
+ graph->pe_rep[j] = -1;
+ graph->indirect_cycles[j] = -1;
+ }
+}
+
/* Build the constraint graph, adding only predecessor edges right now. */
static void
constraint_t c;
unsigned int j;
- graph = XNEW (struct constraint_graph);
- graph->size = (VEC_length (varinfo_t, varmap)) * 3;
- graph->succs = XCNEWVEC (bitmap, graph->size);
graph->implicit_preds = XCNEWVEC (bitmap, graph->size);
graph->preds = XCNEWVEC (bitmap, graph->size);
- graph->indirect_cycles = XNEWVEC (int, VEC_length (varinfo_t, varmap));
- graph->label = XCNEWVEC (unsigned int, graph->size);
- graph->rep = XNEWVEC (unsigned int, 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->complex = XCNEWVEC (VEC(constraint_t, heap) *,
- VEC_length (varinfo_t, varmap));
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++)
}
for (j = 0; j < graph->size; j++)
- {
- graph->rep[j] = j;
- graph->eq_rep[j] = -1;
- }
+ graph->eq_rep[j] = -1;
for (j = 0; j < VEC_length (varinfo_t, varmap); j++)
graph->indirect_cycles[j] = -1;
{
struct constraint_expr lhs = c->lhs;
struct constraint_expr rhs = c->rhs;
- unsigned int lhsvar = get_varinfo_fc (lhs.var)->id;
- unsigned int rhsvar = get_varinfo_fc (rhs.var)->id;
+ unsigned int lhsvar = lhs.var;
+ unsigned int rhsvar = rhs.var;
if (lhs.type == DEREF)
{
/* *x = y. */
if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
add_pred_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
- if (rhs.type == ADDRESSOF)
- RESET_BIT (graph->direct_nodes, rhsvar);
}
else if (rhs.type == DEREF)
{
}
else if (rhs.type == ADDRESSOF)
{
+ varinfo_t v;
+
/* x = &y */
- add_pred_graph_edge (graph, lhsvar, FIRST_ADDR_NODE + 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);
+ /* All related variables are no longer direct nodes. */
RESET_BIT (graph->direct_nodes, rhsvar);
+ v = get_varinfo (rhsvar);
+ if (!v->is_full_var)
+ {
+ v = lookup_vi_for_tree (v->decl);
+ do
+ {
+ RESET_BIT (graph->direct_nodes, v->id);
+ v = v->next;
+ }
+ while (v != NULL);
+ }
+ bitmap_set_bit (graph->address_taken, rhsvar);
}
else if (lhsvar > anything_id
&& lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
{
if (rhs.offset != 0)
RESET_BIT (graph->direct_nodes, lhs.var);
- if (lhs.offset != 0)
+ else if (lhs.offset != 0)
RESET_BIT (graph->direct_nodes, rhs.var);
}
}
static void
build_succ_graph (void)
{
- int i;
+ unsigned i, t;
constraint_t c;
for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
lhs = c->lhs;
rhs = c->rhs;
- lhsvar = find (get_varinfo_fc (lhs.var)->id);
- rhsvar = find (get_varinfo_fc (rhs.var)->id);
+ lhsvar = find (lhs.var);
+ rhsvar = find (rhs.var);
if (lhs.type == DEREF)
{
else if (rhs.type == ADDRESSOF)
{
/* x = &y */
- gcc_assert (find (get_varinfo_fc (rhs.var)->id)
- == get_varinfo_fc (rhs.var)->id);
+ gcc_assert (find (rhs.var) == rhs.var);
bitmap_set_bit (get_varinfo (lhsvar)->solution, rhsvar);
}
else if (lhsvar > anything_id
add_graph_edge (graph, lhsvar, rhsvar);
}
}
+
+ /* Add edges from STOREDANYTHING to all non-direct nodes. */
+ t = find (storedanything_id);
+ for (i = integer_id + 1; i < FIRST_REF_NODE; ++i)
+ {
+ if (!TEST_BIT (graph->direct_nodes, i))
+ add_graph_edge (graph, find (i), t);
+ }
}
struct scc_info
{
sbitmap visited;
- sbitmap roots;
+ sbitmap deleted;
unsigned int *dfs;
unsigned int *node_mapping;
int current_index;
break;
w = find (i);
- if (TEST_BIT (si->roots, w))
+ if (TEST_BIT (si->deleted, w))
continue;
if (!TEST_BIT (si->visited, w))
lowest_node = bitmap_first_set_bit (scc);
gcc_assert (lowest_node < FIRST_REF_NODE);
+
+ /* Collapse the SCC nodes into a single node, and mark the
+ indirect cycles. */
EXECUTE_IF_SET_IN_BITMAP (scc, 0, i, bi)
{
if (i < FIRST_REF_NODE)
{
- /* Mark this node for collapsing. */
if (unite (lowest_node, i))
unify_nodes (graph, lowest_node, i, false);
}
}
}
}
- SET_BIT (si->roots, n);
+ SET_BIT (si->deleted, n);
}
else
VEC_safe_push (unsigned, heap, si->scc_stack, n);
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))
{
RESET_BIT (changed, from);
changed_count--;
}
}
-
- /* If the solution changes because of the merging, we need to mark
- the variable as changed. */
- if (bitmap_ior_into (get_varinfo (to)->solution,
- get_varinfo (from)->solution))
+ if (get_varinfo (from)->solution)
{
- if (update_changed && !TEST_BIT (changed, to))
+ /* 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))
{
- SET_BIT (changed, to);
- changed_count++;
+ if (update_changed && !TEST_BIT (changed, to))
+ {
+ SET_BIT (changed, to);
+ changed_count++;
+ }
+ }
+
+ BITMAP_FREE (get_varinfo (from)->solution);
+ BITMAP_FREE (get_varinfo (from)->oldsolution);
+
+ if (stats.iterations > 0)
+ {
+ BITMAP_FREE (get_varinfo (to)->oldsolution);
+ get_varinfo (to)->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
}
}
-
- BITMAP_FREE (get_varinfo (from)->solution);
- BITMAP_FREE (get_varinfo (from)->oldsolution);
-
- if (stats.iterations > 0)
- {
- BITMAP_FREE (get_varinfo (to)->oldsolution);
- get_varinfo (to)->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
- }
-
if (valid_graph_edge (graph, to, to))
{
if (graph->succs[to])
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);
VEC_safe_push (unsigned, heap, ti->topo_order, n);
}
-/* Return true if variable N + OFFSET is a legal field of N. */
-
-static bool
-type_safe (unsigned int n, unsigned HOST_WIDE_INT *offset)
-{
- varinfo_t ninfo = get_varinfo (n);
-
- /* For things we've globbed to single variables, any offset into the
- variable acts like the entire variable, so that it becomes offset
- 0. */
- if (ninfo->is_special_var
- || ninfo->is_artificial_var
- || ninfo->is_unknown_size_var)
- {
- *offset = 0;
- return true;
- }
- return (get_varinfo (n)->offset + *offset) < get_varinfo (n)->fullsize;
-}
-
-/* Process a constraint C that represents *x = &y. */
-
-static void
-do_da_constraint (constraint_graph_t graph ATTRIBUTE_UNUSED,
- constraint_t c, bitmap delta)
-{
- unsigned int rhs = c->rhs.var;
- unsigned int j;
- bitmap_iterator bi;
-
- /* For each member j of Delta (Sol(x)), add x to Sol(j) */
- EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
- {
- unsigned HOST_WIDE_INT offset = c->lhs.offset;
- if (type_safe (j, &offset) && !(get_varinfo (j)->is_special_var))
- {
- /* *x != NULL && *x != ANYTHING*/
- varinfo_t v;
- unsigned int t;
- bitmap sol;
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (j)->offset + offset;
-
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
- continue;
- t = find (v->id);
- sol = get_varinfo (t)->solution;
- if (!bitmap_bit_p (sol, rhs))
- {
- bitmap_set_bit (sol, rhs);
- if (!TEST_BIT (changed, t))
- {
- SET_BIT (changed, t);
- changed_count++;
- }
- }
- }
- else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
- fprintf (dump_file, "Untypesafe usage in do_da_constraint.\n");
-
- }
-}
-
-/* Process a constraint C that represents x = *y, using DELTA as the
- starting solution. */
+/* Process a constraint C that represents x = *(y + off), using DELTA as the
+ starting solution for y. */
static void
do_sd_constraint (constraint_graph_t graph, constraint_t c,
bitmap delta)
{
- unsigned int lhs = find (c->lhs.var);
+ unsigned int lhs = c->lhs.var;
bool flag = false;
bitmap sol = get_varinfo (lhs)->solution;
unsigned int j;
bitmap_iterator bi;
+ HOST_WIDE_INT roffset = c->rhs.offset;
+
+ /* Our IL does not allow this. */
+ gcc_assert (c->lhs.offset == 0);
+
+ /* If the solution of Y contains anything it is good enough to transfer
+ this to the LHS. */
+ if (bitmap_bit_p (delta, anything_id))
+ {
+ flag |= bitmap_set_bit (sol, anything_id);
+ goto done;
+ }
+
+ /* If we do not know at with offset the rhs is dereferenced compute
+ the reachability set of DELTA, conservatively assuming it is
+ dereferenced at all valid offsets. */
+ if (roffset == UNKNOWN_OFFSET)
+ {
+ solution_set_expand (delta, delta);
+ /* No further offset processing is necessary. */
+ roffset = 0;
+ }
- 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 HOST_WIDE_INT roffset = c->rhs.offset;
- if (type_safe (j, &roffset))
- {
- varinfo_t v;
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (j)->offset + roffset;
- unsigned int t;
+ varinfo_t v = get_varinfo (j);
+ HOST_WIDE_INT fieldoffset = v->offset + roffset;
+ unsigned int t;
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
- continue;
+ if (v->is_full_var)
+ fieldoffset = v->offset;
+ else if (roffset != 0)
+ v = first_vi_for_offset (v, fieldoffset);
+ /* If the access is outside of the variable we can ignore it. */
+ if (!v)
+ continue;
+
+ do
+ {
t = find (v->id);
/* Adding edges from the special vars is pointless.
They don't have sets that can change. */
- if (get_varinfo (t) ->is_special_var)
+ if (get_varinfo (t)->is_special_var)
flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
+ /* Merging the solution from ESCAPED needlessly increases
+ the set. Use ESCAPED as representative instead. */
+ else if (v->id == escaped_id)
+ flag |= bitmap_set_bit (sol, escaped_id);
else if (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");
+ /* If the variable is not exactly at the requested offset
+ we have to include the next one. */
+ if (v->offset == (unsigned HOST_WIDE_INT)fieldoffset
+ || v->next == NULL)
+ break;
+
+ v = v->next;
+ fieldoffset = v->offset;
+ }
+ while (1);
}
done:
}
}
-/* Process a constraint C that represents *x = y. */
+/* Process a constraint C that represents *(x + off) = y using DELTA
+ as the starting solution for x. */
static void
do_ds_constraint (constraint_t c, bitmap delta)
{
- unsigned int rhs = find (c->rhs.var);
- unsigned HOST_WIDE_INT roff = c->rhs.offset;
+ unsigned int rhs = c->rhs.var;
bitmap sol = get_varinfo (rhs)->solution;
unsigned int j;
bitmap_iterator bi;
+ HOST_WIDE_INT loff = c->lhs.offset;
- if (bitmap_bit_p (sol, anything_id))
- {
- EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
- {
- varinfo_t jvi = get_varinfo (j);
- unsigned int t;
- unsigned int loff = c->lhs.offset;
- unsigned HOST_WIDE_INT fieldoffset = jvi->offset + loff;
- varinfo_t v;
-
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
- continue;
- t = find (v->id);
-
- if (!bitmap_bit_p (get_varinfo (t)->solution, anything_id))
- {
- bitmap_set_bit (get_varinfo (t)->solution, anything_id);
- if (!TEST_BIT (changed, t))
- {
- SET_BIT (changed, t);
- changed_count++;
- }
- }
- }
- return;
- }
+ /* Our IL does not allow this. */
+ gcc_assert (c->rhs.offset == 0);
- /* For each member j of delta (Sol(x)), add an edge from y to j and
- union Sol(y) into Sol(j) */
- EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
+ /* If the solution of y contains ANYTHING simply use the ANYTHING
+ solution. This avoids needlessly increasing the points-to sets. */
+ if (bitmap_bit_p (sol, anything_id))
+ sol = get_varinfo (find (anything_id))->solution;
+
+ /* If the solution for x contains ANYTHING we have to merge the
+ solution of y into all pointer variables which we do via
+ STOREDANYTHING. */
+ if (bitmap_bit_p (delta, anything_id))
{
- unsigned HOST_WIDE_INT loff = c->lhs.offset;
- if (type_safe (j, &loff) && !(get_varinfo (j)->is_special_var))
+ unsigned t = find (storedanything_id);
+ if (add_graph_edge (graph, t, rhs))
{
- varinfo_t v;
- unsigned int t;
- unsigned HOST_WIDE_INT fieldoffset = get_varinfo (j)->offset + loff;
- bitmap tmp;
-
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
- if (!v)
- continue;
- t = find (v->id);
- tmp = get_varinfo (t)->solution;
-
- if (set_union_with_increment (tmp, sol, roff))
+ if (bitmap_ior_into (get_varinfo (t)->solution, sol))
{
- get_varinfo (t)->solution = tmp;
- if (t == rhs)
- sol = get_varinfo (rhs)->solution;
if (!TEST_BIT (changed, t))
{
SET_BIT (changed, t);
}
}
}
- else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
- fprintf (dump_file, "Untypesafe usage in do_ds_constraint\n");
+ return;
}
-}
-
-/* Handle a non-simple (simple meaning requires no iteration),
- constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
-static void
-do_complex_constraint (constraint_graph_t graph, constraint_t c, bitmap delta)
-{
- if (c->lhs.type == DEREF)
+ /* If we do not know at with offset the rhs is dereferenced compute
+ the reachability set of DELTA, conservatively assuming it is
+ dereferenced at all valid offsets. */
+ if (loff == UNKNOWN_OFFSET)
{
- if (c->rhs.type == ADDRESSOF)
- {
- /* *x = &y */
- do_da_constraint (graph, c, delta);
- }
- else
- {
- /* *x = y */
- do_ds_constraint (c, delta);
- }
+ solution_set_expand (delta, delta);
+ loff = 0;
}
- else if (c->rhs.type == DEREF)
+
+ /* For each member j of delta (Sol(x)), add an edge from y to j and
+ union Sol(y) into Sol(j) */
+ EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
{
- /* x = *y */
+ varinfo_t v = get_varinfo (j);
+ unsigned int t;
+ HOST_WIDE_INT fieldoffset = v->offset + loff;
+
+ if (v->is_special_var)
+ continue;
+
+ if (v->is_full_var)
+ fieldoffset = v->offset;
+ else if (loff != 0)
+ v = first_vi_for_offset (v, fieldoffset);
+ /* If the access is outside of the variable we can ignore it. */
+ if (!v)
+ continue;
+
+ do
+ {
+ if (v->may_have_pointers)
+ {
+ t = find (v->id);
+ if (add_graph_edge (graph, t, rhs))
+ {
+ if (bitmap_ior_into (get_varinfo (t)->solution, sol))
+ {
+ if (t == rhs)
+ sol = get_varinfo (rhs)->solution;
+ if (!TEST_BIT (changed, t))
+ {
+ SET_BIT (changed, t);
+ changed_count++;
+ }
+ }
+ }
+ }
+
+ /* If the variable is not exactly at the requested offset
+ we have to include the next one. */
+ if (v->offset == (unsigned HOST_WIDE_INT)fieldoffset
+ || v->next == NULL)
+ break;
+
+ v = v->next;
+ fieldoffset = v->offset;
+ }
+ while (1);
+ }
+}
+
+/* Handle a non-simple (simple meaning requires no iteration),
+ constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
+
+static void
+do_complex_constraint (constraint_graph_t graph, constraint_t c, bitmap delta)
+{
+ if (c->lhs.type == DEREF)
+ {
+ if (c->rhs.type == ADDRESSOF)
+ {
+ gcc_unreachable();
+ }
+ else
+ {
+ /* *x = y */
+ do_ds_constraint (c, delta);
+ }
+ }
+ else if (c->rhs.type == DEREF)
+ {
+ /* x = *y */
if (!(get_varinfo (c->lhs.var)->is_special_var))
do_sd_constraint (graph, c, delta);
}
bitmap tmp;
bitmap solution;
bool flag = false;
- unsigned int t;
gcc_assert (c->rhs.type == SCALAR && c->lhs.type == SCALAR);
- t = find (c->rhs.var);
- solution = get_varinfo (t)->solution;
- t = find (c->lhs.var);
- tmp = get_varinfo (t)->solution;
+ 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;
- if (!TEST_BIT (changed, t))
+ get_varinfo (c->lhs.var)->solution = tmp;
+ if (!TEST_BIT (changed, c->lhs.var))
{
- SET_BIT (changed, t);
+ SET_BIT (changed, c->lhs.var);
changed_count++;
}
}
si->current_index = 0;
si->visited = sbitmap_alloc (size);
sbitmap_zero (si->visited);
- si->roots = sbitmap_alloc (size);
- sbitmap_zero (si->roots);
+ si->deleted = sbitmap_alloc (size);
+ sbitmap_zero (si->deleted);
si->node_mapping = XNEWVEC (unsigned int, size);
si->dfs = XCNEWVEC (unsigned int, size);
free_scc_info (struct scc_info *si)
{
sbitmap_free (si->visited);
- sbitmap_free (si->roots);
+ sbitmap_free (si->deleted);
free (si->node_mapping);
free (si->dfs);
VEC_free (unsigned, heap, si->scc_stack);
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) && find (i) == i)
topo_visit (graph, ti, i);
}
-/* Perform offline variable substitution.
+/* Structure used to for hash value numbering of pointer equivalence
+ classes. */
+
+typedef struct equiv_class_label
+{
+ hashval_t hashcode;
+ unsigned int equivalence_class;
+ bitmap labels;
+} *equiv_class_label_t;
+typedef const struct equiv_class_label *const_equiv_class_label_t;
+
+/* A hashtable for mapping a bitmap of labels->pointer equivalence
+ classes. */
+static htab_t pointer_equiv_class_table;
+
+/* A hashtable for mapping a bitmap of labels->location equivalence
+ classes. */
+static htab_t location_equiv_class_table;
+
+/* Hash function for a equiv_class_label_t */
+
+static hashval_t
+equiv_class_label_hash (const void *p)
+{
+ const_equiv_class_label_t const ecl = (const_equiv_class_label_t) p;
+ return ecl->hashcode;
+}
+
+/* Equality function for two equiv_class_label_t's. */
+
+static int
+equiv_class_label_eq (const void *p1, const void *p2)
+{
+ const_equiv_class_label_t const eql1 = (const_equiv_class_label_t) p1;
+ const_equiv_class_label_t const eql2 = (const_equiv_class_label_t) p2;
+ return 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;
+}
- 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.
+/* Perform offline variable substitution.
- 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.
+ 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.
- There is an optimal way to do this involving hash based value
- numbering, once the technique is published i will implement it
- here.
+ 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.
- Add fake nodes (ADDRESS nodes) and edges for a = &b constraints.
- Initialize all non-REF/ADDRESS nodes to be direct nodes
- For each SCC in the predecessor graph:
- for each member (x) of the SCC
- if x is not a direct node:
- set rootnode(SCC) to be not a direct node
- collapse node x into rootnode(SCC).
- if rootnode(SCC) is not a direct node:
- label rootnode(SCC) with a new equivalence class
- else:
- if all labeled predecessors of rootnode(SCC) have the same
- label:
- label rootnode(SCC) with this label
- else:
- label rootnode(SCC) with a new equivalence class
+ 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 move_complex_constraints.
-*/
+ 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. */
-static int equivalence_class;
+/* 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 equivalence classes.
- This is used during variable substitution to find cycles involving
- the regular or implicit predecessors, and label them as equivalent.
- The SCC finding algorithm used is the same as that for scc_visit. */
+ and label it's nodes with DFS numbers. */
static void
-label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
+condense_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
{
unsigned int i;
bitmap_iterator bi;
{
unsigned int w = si->node_mapping[i];
- if (TEST_BIT (si->roots, w))
+ if (TEST_BIT (si->deleted, w))
continue;
if (!TEST_BIT (si->visited, w))
- label_visit (graph, si, w);
+ condense_visit (graph, si, w);
{
unsigned int t = si->node_mapping[w];
unsigned int nnode = si->node_mapping[n];
{
unsigned int w = si->node_mapping[i];
- if (TEST_BIT (si->roots, w))
+ if (TEST_BIT (si->deleted, w))
continue;
if (!TEST_BIT (si->visited, w))
- label_visit (graph, si, w);
+ condense_visit (graph, si, w);
{
unsigned int t = si->node_mapping[w];
unsigned int nnode = si->node_mapping[n];
if (!TEST_BIT (graph->direct_nodes, w))
RESET_BIT (graph->direct_nodes, n);
- }
- SET_BIT (si->roots, n);
- if (!TEST_BIT (graph->direct_nodes, n))
- {
- graph->label[n] = equivalence_class++;
+ /* 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]);
+ }
}
- else
- {
- unsigned int size = 0;
- unsigned int firstlabel = ~0;
+ SET_BIT (si->deleted, n);
+ }
+ else
+ VEC_safe_push (unsigned, heap, si->scc_stack, n);
+}
- EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
- {
- unsigned int j = si->node_mapping[i];
+/* Label pointer equivalences. */
- if (j == n || graph->label[j] == 0)
- continue;
+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 (firstlabel == (unsigned int)~0)
- {
- firstlabel = graph->label[j];
- size++;
- }
- else if (graph->label[j] != firstlabel)
- size++;
- }
+ if (!graph->points_to[n])
+ graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack);
- if (size == 0)
- graph->label[n] = 0;
- else if (size == 1)
- graph->label[n] = firstlabel;
- else
- graph->label[n] = equivalence_class++;
+ /* 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;
}
- else
- VEC_safe_push (unsigned, heap, si->scc_stack, n);
}
/* Perform offline variable substitution, discovering equivalence
struct scc_info *si = init_scc_info (size);
bitmap_obstack_initialize (&iteration_obstack);
- equivalence_class = 0;
+ 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]);
- /* We only need to visit the non-address nodes for labeling
- purposes, as the address nodes will never have any predecessors,
- because &x never appears on the LHS of a constraint. */
- for (i = 0; i < LAST_REF_NODE; i++)
+ sbitmap_zero (si->visited);
+ /* Actually the label the nodes for pointer equivalences */
+ for (i = 0; i < FIRST_REF_NODE; i++)
if (!TEST_BIT (si->visited, si->node_mapping[i]))
label_visit (graph, si, si->node_mapping[i]);
+ /* Calculate location equivalence labels. */
+ for (i = 0; i < FIRST_REF_NODE; i++)
+ {
+ bitmap pointed_by;
+ bitmap_iterator bi;
+ unsigned int j;
+ unsigned int label;
+
+ if (!graph->pointed_by[i])
+ continue;
+ pointed_by = BITMAP_ALLOC (&iteration_obstack);
+
+ /* Translate the pointed-by mapping for pointer equivalence
+ labels. */
+ EXECUTE_IF_SET_IN_BITMAP (graph->pointed_by[i], 0, j, bi)
+ {
+ bitmap_set_bit (pointed_by,
+ graph->pointer_label[si->node_mapping[j]]);
+ }
+ /* The original pointed_by is now dead. */
+ BITMAP_FREE (graph->pointed_by[i]);
+
+ /* Look up the location equivalence label if one exists, or make
+ one otherwise. */
+ label = equiv_class_lookup (location_equiv_class_table,
+ pointed_by);
+ if (label == 0)
+ {
+ label = location_equiv_class++;
+ equiv_class_add (location_equiv_class_table,
+ label, pointed_by);
+ }
+ else
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found location equivalence for node %s\n",
+ get_varinfo (i)->name);
+ BITMAP_FREE (pointed_by);
+ }
+ graph->loc_label[i] = label;
+
+ }
+
if (dump_file && (dump_flags & TDF_DETAILS))
for (i = 0; i < FIRST_REF_NODE; i++)
{
bool direct_node = TEST_BIT (graph->direct_nodes, i);
fprintf (dump_file,
- "Equivalence class for %s node id %d:%s is %d\n",
+ "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->label[si->node_mapping[i]]);
+ graph->pointer_label[si->node_mapping[i]],
+ graph->loc_label[si->node_mapping[i]]);
}
/* Quickly eliminate our non-pointer variables. */
{
unsigned int node = si->node_mapping[i];
- if (graph->label[node] == 0 && TEST_BIT (graph->direct_nodes, node))
+ if (graph->pointer_label[node] == 0)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file,
clear_edges_for_node (graph, node);
}
}
+
return si;
}
free_var_substitution_info (struct scc_info *si)
{
free_scc_info (si);
- free (graph->label);
+ 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);
}
/* 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. */
+ locations, and we can unite them later. */
- if (graph->label[FIRST_ADDR_NODE + node] == 0)
+ if (!bitmap_bit_p (graph->address_taken, node))
{
gcc_assert (label < graph->size);
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;
}
-/* Move complex constraints to the appropriate nodes, and collapse
- variables we've discovered are equivalent during variable
- substitution. SI is the SCC_INFO that is the result of
- perform_variable_substitution. */
+/* 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
-move_complex_constraints (constraint_graph_t graph,
- struct scc_info *si)
+rewrite_constraints (constraint_graph_t graph,
+ struct scc_info *si)
{
int i;
unsigned int j;
{
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 lhsvar = find (lhs.var);
+ unsigned int rhsvar = find (rhs.var);
unsigned int lhsnode, rhsnode;
unsigned int lhslabel, rhslabel;
lhsnode = si->node_mapping[lhsvar];
rhsnode = si->node_mapping[rhsvar];
- lhslabel = graph->label[lhsnode];
- rhslabel = graph->label[rhsnode];
+ 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 (!TEST_BIT (graph->direct_nodes, lhsnode))
- lhslabel = graph->label[lhsnode] = equivalence_class++;
- else
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- 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;
+
+ 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 (!TEST_BIT (graph->direct_nodes, rhsnode))
- rhslabel = graph->label[rhsnode] = equivalence_class++;
- else
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- 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;
+
+ 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);
c->lhs.var = lhsvar;
c->rhs.var = rhsvar;
- if (lhs.type == DEREF)
- {
- if (rhs.type == ADDRESSOF || rhsvar > anything_id)
- insert_into_complex (graph, lhsvar, c);
- }
- else if (rhs.type == DEREF)
- {
- if (!(get_varinfo (lhsvar)->is_special_var))
- insert_into_complex (graph, rhsvar, c);
- }
- else if (rhs.type != ADDRESSOF && lhsvar > anything_id
- && (lhs.offset != 0 || rhs.offset != 0))
- {
- insert_into_complex (graph, rhsvar, c);
- }
-
}
}
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;
/* 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
if (!solution_empty)
{
bitmap_iterator bi;
+ unsigned eff_escaped_id = find (escaped_id);
/* Propagate solution to all successors. */
EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i],
if (to == i)
continue;
- flag = set_union_with_increment (tmp, pts, 0);
+ /* If we propagate from ESCAPED use ESCAPED as
+ placeholder. */
+ if (i == eff_escaped_id)
+ flag = bitmap_set_bit (tmp, escaped_id);
+ else
+ flag = set_union_with_increment (tmp, pts, 0);
if (flag)
{
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
if (TREE_CODE (t) == SSA_NAME
&& TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL
&& SSA_NAME_IS_DEFAULT_DEF (t))
- return get_constraint_exp_from_ssa_var (SSA_NAME_VAR (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_vi_for_tree (t)->id;
+ cexpr.offset = 0;
/* If we determine the result is "anything", and we know this is readonly,
say it points to readonly memory instead. */
if (cexpr.var == anything_id && TREE_READONLY (t))
{
+ gcc_unreachable ();
cexpr.type = ADDRESSOF;
cexpr.var = readonly_id;
}
- cexpr.offset = 0;
- return cexpr;
+ /* If we are not taking the address of the constraint expr, add all
+ sub-fiels of the variable as well. */
+ if (!address_p)
+ {
+ 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));
- 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;
- }
+ /* If we didn't get any useful constraint from the lhs we get
+ &ANYTHING as fallback from get_constraint_for. Deal with
+ it here by turning it into *ANYTHING. */
+ if (lhs.type == ADDRESSOF
+ && lhs.var == anything_id)
+ lhs.type = DEREF;
- /* ANYTHING == ANYTHING is pointless. */
- if (lhs.var == anything_id && rhs.var == anything_id)
- return;
+ /* ADDRESSOF on the lhs is invalid. */
+ gcc_assert (lhs.type != ADDRESSOF);
- /* If we have &ANYTHING = something, convert to SOMETHING = &ANYTHING) */
- else if (lhs.var == anything_id && lhs.type == ADDRESSOF)
- {
- rhs = t->lhs;
- t->lhs = t->rhs;
- t->rhs = rhs;
- process_constraint (t);
- }
/* This can happen in our IR with things like n->a = *p */
- else if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
+ if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
{
/* Split into tmp = *rhs, *lhs = tmp */
tree rhsdecl = get_varinfo (rhs.var)->decl;
tree pointertype = TREE_TYPE (rhsdecl);
tree pointedtotype = TREE_TYPE (pointertype);
tree tmpvar = create_tmp_var_raw (pointedtotype, "doubledereftmp");
- struct constraint_expr tmplhs = get_constraint_exp_from_ssa_var (tmpvar);
-
- /* If this is an aggregate of known size, we should have passed
- this off to do_structure_copy, and it should have broken it
- up. */
- gcc_assert (!AGGREGATE_TYPE_P (pointedtotype)
- || get_varinfo (rhs.var)->is_unknown_size_var);
+ struct constraint_expr tmplhs = get_constraint_exp_for_temp (tmpvar);
process_constraint (new_constraint (tmplhs, rhs));
process_constraint (new_constraint (lhs, tmplhs));
}
- else
+ else if (rhs.type == ADDRESSOF && lhs.type == DEREF)
{
- gcc_assert (rhs.type != ADDRESSOF || rhs.offset == 0);
- VEC_safe_push (constraint_t, heap, constraints, t);
- }
+ /* 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);
+
+ process_constraint (new_constraint (tmplhs, rhs));
+ process_constraint (new_constraint (lhs, tmplhs));
+ }
+ else
+ {
+ gcc_assert (rhs.type != ADDRESSOF || rhs.offset == 0);
+ VEC_safe_push (constraint_t, heap, constraints, t);
+ }
+}
+
+/* Return true if T is a type that could contain pointers. */
+
+static bool
+type_could_have_pointers (tree type)
+{
+ if (POINTER_TYPE_P (type))
+ return true;
+
+ if (TREE_CODE (type) == ARRAY_TYPE)
+ return type_could_have_pointers (TREE_TYPE (type));
+
+ return AGGREGATE_TYPE_P (type);
}
/* Return true if T is a variable of a type that could contain
static bool
could_have_pointers (tree t)
{
- tree type = TREE_TYPE (t);
-
- if (POINTER_TYPE_P (type)
- || AGGREGATE_TYPE_P (type)
- || TREE_CODE (type) == COMPLEX_TYPE)
- return true;
-
- return false;
+ return type_could_have_pointers (TREE_TYPE (t));
}
/* Return the position, in bits, of FIELD_DECL from the beginning of its
structure. */
-static unsigned HOST_WIDE_INT
+static HOST_WIDE_INT
bitpos_of_field (const tree fdecl)
{
- if (TREE_CODE (DECL_FIELD_OFFSET (fdecl)) != INTEGER_CST
- || TREE_CODE (DECL_FIELD_BIT_OFFSET (fdecl)) != INTEGER_CST)
+ if (!host_integerp (DECL_FIELD_OFFSET (fdecl), 0)
+ || !host_integerp (DECL_FIELD_BIT_OFFSET (fdecl), 0))
return -1;
- return (tree_low_cst (DECL_FIELD_OFFSET (fdecl), 1) * 8)
- + tree_low_cst (DECL_FIELD_BIT_OFFSET (fdecl), 1);
+ return (TREE_INT_CST_LOW (DECL_FIELD_OFFSET (fdecl)) * 8
+ + TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fdecl)));
}
-/* Return true if an access to [ACCESSPOS, ACCESSSIZE]
- overlaps with a field at [FIELDPOS, FIELDSIZE] */
+/* Get constraint expressions for offsetting PTR by OFFSET. Stores the
+ resulting constraint expressions in *RESULTS. */
-static 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;
+ 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. */
+ if (!host_integerp (offset, 0))
+ rhsoffset = UNKNOWN_OFFSET;
+ else
+ {
+ /* Make sure the bit-offset also fits. */
+ rhsunitoffset = TREE_INT_CST_LOW (offset);
+ rhsoffset = rhsunitoffset * BITS_PER_UNIT;
+ if (rhsunitoffset != rhsoffset / BITS_PER_UNIT)
+ rhsoffset = UNKNOWN_OFFSET;
+ }
+
+ get_constraint_for (ptr, results);
+ if (rhsoffset == 0)
+ return;
+
+ /* As we are eventually appending to the solution do not use
+ VEC_iterate here. */
+ n = VEC_length (ce_s, *results);
+ for (j = 0; j < n; j++)
+ {
+ varinfo_t curr;
+ c = VEC_index (ce_s, *results, j);
+ curr = get_varinfo (c->var);
+
+ if (c->type == ADDRESSOF
+ /* If this varinfo represents a full variable just use it. */
+ && curr->is_full_var)
+ c->offset = 0;
+ else if (c->type == ADDRESSOF
+ /* If we do not know the offset add all subfields. */
+ && rhsoffset == UNKNOWN_OFFSET)
+ {
+ varinfo_t temp = lookup_vi_for_tree (curr->decl);
+ do
+ {
+ struct constraint_expr c2;
+ c2.var = temp->id;
+ c2.type = ADDRESSOF;
+ c2.offset = 0;
+ VEC_safe_push (ce_s, heap, *results, &c2);
+ temp = temp->next;
+ }
+ while (temp);
+ }
+ else if (c->type == ADDRESSOF)
+ {
+ varinfo_t temp;
+ unsigned HOST_WIDE_INT offset = curr->offset + rhsoffset;
+
+ /* Search the sub-field which overlaps with the
+ pointed-to offset. If the result is outside of the variable
+ we have to provide a conservative result, as the variable is
+ still reachable from the resulting pointer (even though it
+ technically cannot point to anything). The last and first
+ sub-fields are such conservative results.
+ ??? If we always had a sub-field for &object + 1 then
+ we could represent this in a more precise way. */
+ if (rhsoffset < 0
+ && curr->offset < offset)
+ offset = 0;
+ temp = first_or_preceding_vi_for_offset (curr, offset);
+
+ /* If the found variable is not exactly at the pointed to
+ result, we have to include the next variable in the
+ solution as well. Otherwise two increments by offset / 2
+ do not result in the same or a conservative superset
+ solution. */
+ if (temp->offset != offset
+ && temp->next != NULL)
+ {
+ struct constraint_expr c2;
+ c2.var = temp->next->id;
+ c2.type = ADDRESSOF;
+ c2.offset = 0;
+ VEC_safe_push (ce_s, heap, *results, &c2);
+ }
+ c->var = temp->id;
+ c->offset = 0;
+ }
+ else
+ c->offset = rhsoffset;
+ }
}
-/* 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 (result->type == DEREF)
+ {
+ /* If we do not know exactly where the access goes say so. Note
+ that only for non-structure accesses we know that we access
+ at most one subfiled of any variable. */
+ if (bitpos == -1
+ || bitsize != bitmaxsize
+ || AGGREGATE_TYPE_P (TREE_TYPE (orig_t)))
+ result->offset = UNKNOWN_OFFSET;
+ else
+ result->offset = bitpos;
+ }
+ else if (result->type == ADDRESSOF)
+ {
+ /* We can end up here for component references on a
+ VIEW_CONVERT_EXPR <>(&foobar). */
+ result->type = SCALAR;
+ result->var = anything_id;
result->offset = 0;
}
+ else
+ gcc_unreachable ();
}
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;
happens below, since it will fall into the default case. The only
case we know something about an integer treated like a pointer is
when it is the NULL pointer, and then we just say it points to
- NULL. */
- if (TREE_CODE (t) == INTEGER_CST
- && !POINTER_TYPE_P (TREE_TYPE (t)))
+ NULL.
+
+ Do not do that if -fno-delete-null-pointer-checks though, because
+ in that case *NULL does not fail, so it _should_ alias *anything.
+ It is not worth adding a new option or renaming the existing one,
+ since this case is relatively obscure. */
+ if (flag_delete_null_pointer_checks
+ && ((TREE_CODE (t) == INTEGER_CST
+ && integer_zerop (t))
+ /* The only valid CONSTRUCTORs in gimple with pointer typed
+ elements are zero-initializer. */
+ || TREE_CODE (t) == CONSTRUCTOR))
{
- temp.var = integer_id;
- temp.type = SCALAR;
+ temp.var = nothing_id;
+ temp.type = ADDRESSOF;
temp.offset = 0;
VEC_safe_push (ce_s, heap, *results, &temp);
return;
}
- else if (TREE_CODE (t) == INTEGER_CST
- && integer_zerop (t))
+
+ /* String constants are read-only. */
+ if (TREE_CODE (t) == STRING_CST)
{
- temp.var = nothing_id;
- temp.type = ADDRESSOF;
+ temp.var = readonly_id;
+ temp.type = SCALAR;
temp.offset = 0;
VEC_safe_push (ce_s, heap, *results, &temp);
return;
switch (TREE_CODE_CLASS (TREE_CODE (t)))
{
case tcc_expression:
- case tcc_vl_exp:
{
switch (TREE_CODE (t))
{
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 = ADDRESSOF;
- 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;
- }
+ case VIEW_CONVERT_EXPR:
+ get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p);
+ return;
+ /* We are missing handling for TARGET_MEM_REF here. */
+ default:;
}
+ break;
}
case tcc_exceptional:
{
switch (TREE_CODE (t))
{
- case PHI_NODE:
- {
- get_constraint_for (PHI_RESULT (t), results);
- return;
- }
- break;
case SSA_NAME:
{
- struct constraint_expr temp;
- temp = get_constraint_exp_from_ssa_var (t);
- VEC_safe_push (ce_s, heap, *results, &temp);
- 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);
+ get_constraint_for_ssa_var (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;
- }
- }
-}
-
-
-/* Handle the structure copy case where we have a simple structure copy
- between LHS and RHS that is of SIZE (in bits)
-
- For each field of the lhs variable (lhsfield)
- For each field of the rhs variable at lhsfield.offset (rhsfield)
- add the constraint lhsfield = rhsfield
-
- If we fail due to some kind of type unsafety or other thing we
- can't handle, return false. We expect the caller to collapse the
- variable in that case. */
-
-static bool
-do_simple_structure_copy (const struct constraint_expr lhs,
- const struct constraint_expr rhs,
- const unsigned HOST_WIDE_INT size)
-{
- varinfo_t p = get_varinfo (lhs.var);
- unsigned HOST_WIDE_INT pstart, last;
- pstart = p->offset;
- last = p->offset + size;
- for (; p && p->offset < last; p = p->next)
- {
- varinfo_t q;
- struct constraint_expr templhs = lhs;
- struct constraint_expr temprhs = rhs;
- unsigned HOST_WIDE_INT fieldoffset;
-
- templhs.var = p->id;
- q = get_varinfo (temprhs.var);
- fieldoffset = p->offset - pstart;
- q = first_vi_for_offset (q, q->offset + fieldoffset);
- if (!q)
- return false;
- temprhs.var = q->id;
- process_constraint (new_constraint (templhs, temprhs));
+ default:;
}
- return true;
-}
-
-
-/* Handle the structure copy case where we have a structure copy between a
- aggregate on the LHS and a dereference of a pointer on the RHS
- that is of SIZE (in bits)
-
- For each field of the lhs variable (lhsfield)
- rhs.offset = lhsfield->offset
- add the constraint lhsfield = rhs
-*/
-static void
-do_rhs_deref_structure_copy (const struct constraint_expr lhs,
- const struct constraint_expr rhs,
- const unsigned HOST_WIDE_INT size)
-{
- varinfo_t p = get_varinfo (lhs.var);
- unsigned HOST_WIDE_INT pstart,last;
- pstart = p->offset;
- last = p->offset + size;
-
- for (; p && p->offset < last; p = p->next)
- {
- varinfo_t q;
- struct constraint_expr templhs = lhs;
- struct constraint_expr temprhs = rhs;
- unsigned HOST_WIDE_INT fieldoffset;
-
-
- if (templhs.type == SCALAR)
- templhs.var = p->id;
- else
- templhs.offset = p->offset;
-
- q = get_varinfo (temprhs.var);
- fieldoffset = p->offset - pstart;
- temprhs.offset += fieldoffset;
- process_constraint (new_constraint (templhs, temprhs));
- }
+ /* 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);
}
-/* Handle the structure copy case where we have a structure copy
- 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)
- lhs.offset = rhsfield->offset
- add the constraint lhs = rhsfield
-*/
+/* Given a gimple tree T, return the constraint expression vector for it. */
static void
-do_lhs_deref_structure_copy (const struct constraint_expr lhs,
- const struct constraint_expr rhs,
- const unsigned HOST_WIDE_INT size)
-{
- varinfo_t p = get_varinfo (rhs.var);
- unsigned HOST_WIDE_INT pstart,last;
- pstart = p->offset;
- last = p->offset + size;
-
- for (; p && p->offset < last; p = p->next)
- {
- varinfo_t q;
- struct constraint_expr templhs = lhs;
- struct constraint_expr temprhs = rhs;
- unsigned HOST_WIDE_INT fieldoffset;
-
-
- if (temprhs.type == SCALAR)
- temprhs.var = p->id;
- else
- temprhs.offset = p->offset;
-
- q = get_varinfo (templhs.var);
- fieldoffset = p->offset - pstart;
- templhs.offset += fieldoffset;
- process_constraint (new_constraint (templhs, temprhs));
- }
-}
-
-/* Sometimes, frontends like to give us bad type information. This
- function will collapse all the fields from VAR to the end of VAR,
- into VAR, so that we treat those fields as a single variable.
- We return the variable they were collapsed into. */
-
-static unsigned int
-collapse_rest_of_var (unsigned int var)
+get_constraint_for (tree t, VEC (ce_s, heap) **results)
{
- varinfo_t currvar = get_varinfo (var);
- varinfo_t field;
-
- for (field = currvar->next; field; field = field->next)
- {
- if (dump_file)
- fprintf (dump_file, "Type safety: Collapsing var %s into %s\n",
- field->name, currvar->name);
-
- gcc_assert (!field->collapsed_to);
- field->collapsed_to = currvar;
- }
-
- currvar->next = NULL;
- currvar->size = currvar->fullsize - currvar->offset;
+ gcc_assert (VEC_length (ce_s, *results) == 0);
- return currvar->id;
+ get_constraint_for_1 (t, results, false);
}
/* Handle aggregate copies by expanding into copies of the respective
static void
do_structure_copy (tree lhsop, tree rhsop)
{
- struct constraint_expr lhs, rhs, tmp;
+ struct constraint_expr *lhsp, *rhsp;
VEC (ce_s, heap) *lhsc = NULL, *rhsc = NULL;
- varinfo_t p;
- unsigned HOST_WIDE_INT lhssize;
- unsigned HOST_WIDE_INT rhssize;
+ unsigned j;
get_constraint_for (lhsop, &lhsc);
get_constraint_for (rhsop, &rhsc);
- gcc_assert (VEC_length (ce_s, lhsc) == 1);
- gcc_assert (VEC_length (ce_s, rhsc) == 1);
- lhs = *(VEC_last (ce_s, lhsc));
- rhs = *(VEC_last (ce_s, rhsc));
-
- VEC_free (ce_s, heap, lhsc);
- VEC_free (ce_s, heap, rhsc);
-
- /* If we have special var = x, swap it around. */
- if (lhs.var <= integer_id && !(get_varinfo (rhs.var)->is_special_var))
+ lhsp = VEC_index (ce_s, lhsc, 0);
+ rhsp = VEC_index (ce_s, rhsc, 0);
+ if (lhsp->type == DEREF
+ || (lhsp->type == ADDRESSOF && lhsp->var == anything_id)
+ || rhsp->type == DEREF)
{
- tmp = lhs;
- lhs = rhs;
- rhs = tmp;
+ struct constraint_expr tmp;
+ tree tmpvar = create_tmp_var_raw (ptr_type_node,
+ "structcopydereftmp");
+ tmp.var = get_vi_for_tree (tmpvar)->id;
+ tmp.type = SCALAR;
+ tmp.offset = 0;
+ for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); ++j)
+ process_constraint (new_constraint (tmp, *rhsp));
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); ++j)
+ process_constraint (new_constraint (*lhsp, tmp));
}
-
- /* This is fairly conservative for the RHS == ADDRESSOF case, in that it's
- possible it's something we could handle. However, most cases falling
- into this are dealing with transparent unions, which are slightly
- weird. */
- if (rhs.type == ADDRESSOF && !(get_varinfo (rhs.var)->is_special_var))
+ else if (lhsp->type == SCALAR
+ && (rhsp->type == SCALAR
+ || rhsp->type == ADDRESSOF))
{
- rhs.type = ADDRESSOF;
- rhs.var = anything_id;
- }
-
- /* If the RHS is a special var, or an addressof, set all the LHS fields to
- that special var. */
- if (rhs.var <= integer_id)
- {
- for (p = get_varinfo (lhs.var); p; p = p->next)
+ tree lhsbase, rhsbase;
+ HOST_WIDE_INT lhssize, lhsmaxsize, lhsoffset;
+ HOST_WIDE_INT rhssize, rhsmaxsize, rhsoffset;
+ unsigned k = 0;
+ lhsbase = get_ref_base_and_extent (lhsop, &lhsoffset,
+ &lhssize, &lhsmaxsize);
+ rhsbase = get_ref_base_and_extent (rhsop, &rhsoffset,
+ &rhssize, &rhsmaxsize);
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp);)
{
- struct constraint_expr templhs = lhs;
- struct constraint_expr temprhs = rhs;
-
- if (templhs.type == SCALAR )
- templhs.var = p->id;
+ varinfo_t lhsv, rhsv;
+ rhsp = VEC_index (ce_s, rhsc, k);
+ lhsv = get_varinfo (lhsp->var);
+ rhsv = get_varinfo (rhsp->var);
+ if (lhsv->may_have_pointers
+ && ranges_overlap_p (lhsv->offset + rhsoffset, lhsv->size,
+ rhsv->offset + lhsoffset, rhsv->size))
+ process_constraint (new_constraint (*lhsp, *rhsp));
+ if (lhsv->offset + rhsoffset + lhsv->size
+ > rhsv->offset + lhsoffset + rhsv->size)
+ {
+ ++k;
+ if (k >= VEC_length (ce_s, rhsc))
+ break;
+ }
else
- templhs.offset += p->offset;
- process_constraint (new_constraint (templhs, temprhs));
+ ++j;
}
}
else
- {
- tree rhstype = TREE_TYPE (rhsop);
- tree lhstype = TREE_TYPE (lhsop);
- tree rhstypesize;
- tree lhstypesize;
-
- lhstypesize = DECL_P (lhsop) ? DECL_SIZE (lhsop) : TYPE_SIZE (lhstype);
- rhstypesize = DECL_P (rhsop) ? DECL_SIZE (rhsop) : TYPE_SIZE (rhstype);
-
- /* If we have a variably sized types on the rhs or lhs, and a deref
- constraint, add the constraint, lhsconstraint = &ANYTHING.
- This is conservatively correct because either the lhs is an unknown
- sized var (if the constraint is SCALAR), or the lhs is a DEREF
- constraint, and every variable it can point to must be unknown sized
- anyway, so we don't need to worry about fields at all. */
- if ((rhs.type == DEREF && TREE_CODE (rhstypesize) != INTEGER_CST)
- || (lhs.type == DEREF && TREE_CODE (lhstypesize) != INTEGER_CST))
- {
- rhs.var = anything_id;
- rhs.type = ADDRESSOF;
- rhs.offset = 0;
- process_constraint (new_constraint (lhs, rhs));
- return;
- }
+ gcc_unreachable ();
- /* The size only really matters insofar as we don't set more or less of
- the variable. If we hit an unknown size var, the size should be the
- whole darn thing. */
- if (get_varinfo (rhs.var)->is_unknown_size_var)
- rhssize = ~0;
- else
- rhssize = TREE_INT_CST_LOW (rhstypesize);
+ VEC_free (ce_s, heap, lhsc);
+ VEC_free (ce_s, heap, rhsc);
+}
- if (get_varinfo (lhs.var)->is_unknown_size_var)
- lhssize = ~0;
- else
- lhssize = TREE_INT_CST_LOW (lhstypesize);
+/* Create a constraint ID = OP. */
+static void
+make_constraint_to (unsigned id, tree op)
+{
+ VEC(ce_s, heap) *rhsc = NULL;
+ struct constraint_expr *c;
+ struct constraint_expr includes;
+ unsigned int j;
- if (rhs.type == SCALAR && lhs.type == SCALAR)
- {
- if (!do_simple_structure_copy (lhs, rhs, MIN (lhssize, rhssize)))
- {
- lhs.var = collapse_rest_of_var (lhs.var);
- rhs.var = collapse_rest_of_var (rhs.var);
- lhs.offset = 0;
- rhs.offset = 0;
- lhs.type = SCALAR;
- rhs.type = SCALAR;
- process_constraint (new_constraint (lhs, rhs));
- }
- }
- else if (lhs.type != DEREF && rhs.type == DEREF)
- do_rhs_deref_structure_copy (lhs, rhs, MIN (lhssize, rhssize));
- else if (lhs.type == DEREF && rhs.type != DEREF)
- do_lhs_deref_structure_copy (lhs, rhs, MIN (lhssize, rhssize));
- else
- {
- tree pointedtotype = lhstype;
- tree tmpvar;
+ includes.var = id;
+ includes.offset = 0;
+ includes.type = SCALAR;
- gcc_assert (rhs.type == DEREF && lhs.type == DEREF);
- tmpvar = create_tmp_var_raw (pointedtotype, "structcopydereftmp");
- do_structure_copy (tmpvar, rhsop);
- do_structure_copy (lhsop, tmpvar);
- }
- }
+ 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);
}
-
-/* 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. */
+/* Make constraints necessary to make OP escape. */
static void
-update_alias_info (tree stmt, struct alias_info *ai)
+make_escape_constraint (tree op)
{
- bitmap addr_taken;
- use_operand_p use_p;
- ssa_op_iter iter;
- bool stmt_dereferences_ptr_p;
- enum escape_type stmt_escape_type = is_escape_site (stmt);
- struct mem_ref_stats_d *mem_ref_stats = gimple_mem_ref_stats (cfun);
+ make_constraint_to (escaped_id, op);
+}
- stmt_dereferences_ptr_p = false;
+/* For non-IPA mode, generate constraints necessary for a call on the
+ RHS. */
- if (stmt_escape_type == ESCAPE_TO_CALL
- || stmt_escape_type == ESCAPE_TO_PURE_CONST)
- {
- mem_ref_stats->num_call_sites++;
- if (stmt_escape_type == ESCAPE_TO_PURE_CONST)
- mem_ref_stats->num_pure_const_call_sites++;
- }
- else if (stmt_escape_type == ESCAPE_TO_ASM)
- mem_ref_stats->num_asm_sites++;
+static void
+handle_rhs_call (gimple stmt, VEC(ce_s, heap) **results)
+{
+ struct constraint_expr rhsc;
+ unsigned i;
- /* Mark all the variables whose address are taken by the statement. */
- addr_taken = addresses_taken (stmt);
- if (addr_taken)
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
{
- bitmap_ior_into (gimple_addressable_vars (cfun), addr_taken);
+ tree arg = gimple_call_arg (stmt, i);
- /* 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);
- }
- }
+ /* Find those pointers being passed, and make sure they end up
+ pointing to anything. */
+ if (could_have_pointers (arg))
+ make_escape_constraint (arg);
}
- /* Process each operand use. 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;
- unsigned num_uses, num_loads, num_stores;
-
- op = USE_FROM_PTR (use_p);
-
- /* If STMT is a PHI node, OP may be an ADDR_EXPR. If so, add it
- to the set of addressable variables. */
- if (TREE_CODE (op) == ADDR_EXPR)
- {
- bitmap addressable_vars = gimple_addressable_vars (cfun);
-
- gcc_assert (TREE_CODE (stmt) == PHI_NODE);
- gcc_assert (addressable_vars);
-
- /* PHI nodes don't have annotations for pinning the set
- of addresses taken, so we collect them here.
-
- FIXME, should we allow PHI nodes to have annotations
- so that they can be treated like regular statements?
- Currently, they are treated as second-class
- statements. */
- add_to_addressable_set (TREE_OPERAND (op, 0), &addressable_vars);
- continue;
- }
-
- /* Ignore constants (they may occur in PHI node arguments). */
- if (TREE_CODE (op) != SSA_NAME)
- continue;
+ /* The static chain escapes as well. */
+ if (gimple_call_chain (stmt))
+ make_escape_constraint (gimple_call_chain (stmt));
- var = SSA_NAME_VAR (op);
- v_ann = var_ann (var);
-
- /* The base variable of an SSA name must be a GIMPLE register, and thus
- it cannot be aliased. */
- gcc_assert (!may_be_aliased (var));
-
- /* We are only interested in pointers. */
- if (!POINTER_TYPE_P (TREE_TYPE (op)))
- continue;
+ /* Regular functions return nonlocal memory. */
+ rhsc.var = nonlocal_id;
+ rhsc.offset = 0;
+ rhsc.type = SCALAR;
+ VEC_safe_push (ce_s, heap, *results, &rhsc);
+}
- 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) *rhsc)
+{
+ VEC(ce_s, heap) *lhsc = NULL;
+ 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_loads, &num_stores);
-
- /* 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 VDEF/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. */
- 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)
- num_loads++;
- }
+ if (flags & ECF_MALLOC)
+ {
+ struct constraint_expr rhsc;
+ tree heapvar = heapvar_lookup (lhs);
+ varinfo_t vi;
- if (num_loads + num_stores > 0)
+ 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;
-
- /* If this is a store operation, mark OP as being
- dereferenced to store, otherwise mark it as being
- dereferenced to load. */
- if (num_stores > 0)
- pointer_set_insert (ai->dereferenced_ptrs_store, var);
- else
- pointer_set_insert (ai->dereferenced_ptrs_load, var);
-
- /* Update the frequency estimate for all the dereferences of
- pointer OP. */
- update_mem_sym_stats_from_stmt (op, stmt, num_loads, num_stores);
-
- /* Indicate that STMT contains pointer dereferences. */
- stmt_dereferences_ptr_p = true;
+ 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_loads + num_stores < 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)
- {
- pointer_set_insert (ai->dereferenced_ptrs_store, 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;
+ vi->is_unknown_size_var = true;
+ vi->fullsize = ~0;
+ vi->size = ~0;
+ rhsc.type = ADDRESSOF;
+ rhsc.offset = 0;
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhsc));
}
-
- if (TREE_CODE (stmt) == PHI_NODE)
- return;
-
- /* Mark stored variables in STMT as being written to and update the
- memory reference stats for all memory symbols referenced by STMT. */
- if (stmt_references_memory_p (stmt))
+ else if (VEC_length (ce_s, rhsc) > 0)
{
- unsigned i;
- bitmap_iterator bi;
-
- mem_ref_stats->num_mem_stmts++;
-
- /* Notice that we only update memory reference stats for symbols
- loaded and stored by the statement if the statement does not
- contain pointer dereferences and it is not a call/asm site.
- This is to avoid double accounting problems when creating
- memory partitions. After computing points-to information,
- pointer dereference statistics are used to update the
- reference stats of the pointed-to variables, so here we
- should only update direct references to symbols.
-
- Indirect references are not updated here for two reasons: (1)
- The first time we compute alias information, the sets
- LOADED/STORED are empty for pointer dereferences, (2) After
- partitioning, LOADED/STORED may have references to
- partitions, not the original pointed-to variables. So, if we
- always counted LOADED/STORED here and during partitioning, we
- would count many symbols more than once.
-
- This does cause some imprecision when a statement has a
- combination of direct symbol references and pointer
- dereferences (e.g., MEMORY_VAR = *PTR) or if a call site has
- memory symbols in its argument list, but these cases do not
- occur so frequently as to constitute a serious problem. */
- if (STORED_SYMS (stmt))
- EXECUTE_IF_SET_IN_BITMAP (STORED_SYMS (stmt), 0, i, bi)
- {
- tree sym = referenced_var (i);
- pointer_set_insert (ai->written_vars, sym);
- if (!stmt_dereferences_ptr_p
- && stmt_escape_type != ESCAPE_TO_CALL
- && stmt_escape_type != ESCAPE_TO_PURE_CONST
- && stmt_escape_type != ESCAPE_TO_ASM)
- update_mem_sym_stats_from_stmt (sym, stmt, 0, 1);
- }
-
- if (!stmt_dereferences_ptr_p
- && LOADED_SYMS (stmt)
- && stmt_escape_type != ESCAPE_TO_CALL
- && stmt_escape_type != ESCAPE_TO_PURE_CONST
- && stmt_escape_type != ESCAPE_TO_ASM)
- EXECUTE_IF_SET_IN_BITMAP (LOADED_SYMS (stmt), 0, i, bi)
- update_mem_sym_stats_from_stmt (referenced_var (i), stmt, 1, 0);
+ struct constraint_expr *lhsp, *rhsp;
+ unsigned int i, j;
+ /* If the store is to a global decl make sure to
+ add proper escape constraints. */
+ lhs = get_base_address (lhs);
+ if (lhs
+ && DECL_P (lhs)
+ && is_global_var (lhs))
+ {
+ struct constraint_expr tmpc;
+ tmpc.var = escaped_id;
+ tmpc.offset = 0;
+ tmpc.type = SCALAR;
+ VEC_safe_push (ce_s, heap, lhsc, &tmpc);
+ }
+ for (i = 0; VEC_iterate (ce_s, lhsc, i, lhsp); ++i)
+ for (j = 0; VEC_iterate (ce_s, rhsc, j, rhsp); ++j)
+ process_constraint (new_constraint (*lhsp, *rhsp));
}
+ VEC_free (ce_s, heap, lhsc);
}
+/* For non-IPA mode, generate constraints necessary for a call of a
+ const function that returns a pointer in the statement STMT. */
-/* Handle pointer arithmetic EXPR when creating aliasing constraints.
- Expressions of the type PTR + CST can be handled in two ways:
+static void
+handle_const_call (gimple stmt, VEC(ce_s, heap) **results)
+{
+ struct constraint_expr rhsc, tmpc;
+ tree tmpvar = NULL_TREE;
+ unsigned int k;
- 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).
+ /* Treat nested const functions the same as pure functions as far
+ as the static chain is concerned. */
+ if (gimple_call_chain (stmt))
+ {
+ make_constraint_to (callused_id, gimple_call_chain (stmt));
+ rhsc.var = callused_id;
+ rhsc.offset = 0;
+ rhsc.type = SCALAR;
+ VEC_safe_push (ce_s, heap, *results, &rhsc);
+ }
- 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.
+ /* May return arguments. */
+ for (k = 0; k < gimple_call_num_args (stmt); ++k)
+ {
+ tree arg = gimple_call_arg (stmt, k);
- 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. */
+ if (could_have_pointers (arg))
+ {
+ VEC(ce_s, heap) *argc = NULL;
+ struct constraint_expr *argp;
+ int i;
-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 HOST_WIDE_INT rhsoffset = 0;
+ /* We always use a temporary here, otherwise we end up with
+ a quadratic amount of constraints for
+ large_struct = const_call (large_struct);
+ with field-sensitive PTA. */
+ if (tmpvar == NULL_TREE)
+ {
+ tmpvar = create_tmp_var_raw (ptr_type_node, "consttmp");
+ tmpc = get_constraint_exp_for_temp (tmpvar);
+ }
- if (TREE_CODE (expr) != POINTER_PLUS_EXPR)
- return false;
+ 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);
+ }
+ }
+ if (tmpvar != NULL_TREE)
+ VEC_safe_push (ce_s, heap, *results, &tmpc);
+
+ /* May return addresses of globals. */
+ rhsc.var = nonlocal_id;
+ rhsc.offset = 0;
+ rhsc.type = ADDRESSOF;
+ VEC_safe_push (ce_s, heap, *results, &rhsc);
+}
- op0 = TREE_OPERAND (expr, 0);
- op1 = TREE_OPERAND (expr, 1);
- gcc_assert (POINTER_TYPE_P (TREE_TYPE (op0)));
+/* For non-IPA mode, generate constraints necessary for a call to a
+ pure function in statement STMT. */
- get_constraint_for (op0, &temp);
+static void
+handle_pure_call (gimple stmt, VEC(ce_s, heap) **results)
+{
+ struct constraint_expr rhsc;
+ unsigned i;
+ bool need_callused = false;
- /* We can only handle positive offsets that do not overflow
- if we multiply it by BITS_PER_UNIT. */
- if (host_integerp (op1, 1))
+ /* 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 (rhsoffset / BITS_PER_UNIT != TREE_INT_CST_LOW (op1))
- return false;
+ if (could_have_pointers (arg))
+ {
+ make_constraint_to (callused_id, arg);
+ need_callused = true;
+ }
}
- for (i = 0; VEC_iterate (ce_s, lhsc, i, c); i++)
- for (j = 0; VEC_iterate (ce_s, temp, j, c2); j++)
- {
- if (c2->type == ADDRESSOF && rhsoffset != 0)
- {
- varinfo_t temp = get_varinfo (c2->var);
-
- /* An access one after the end of an array is valid,
- so simply punt on accesses we cannot resolve. */
- temp = first_vi_for_offset (temp, rhsoffset);
- if (temp == NULL)
- continue;
- c2->var = temp->id;
- c2->offset = 0;
- }
- else
- c2->offset = rhsoffset;
- process_constraint (new_constraint (*c, *c2));
- }
-
- VEC_free (ce_s, heap, temp);
+ /* The static chain is used as well. */
+ if (gimple_call_chain (stmt))
+ {
+ make_constraint_to (callused_id, gimple_call_chain (stmt));
+ need_callused = true;
+ }
- return true;
+ /* Pure functions may return callused and nonlocal memory. */
+ if (need_callused)
+ {
+ rhsc.var = callused_id;
+ rhsc.offset = 0;
+ rhsc.type = SCALAR;
+ VEC_safe_push (ce_s, heap, *results, &rhsc);
+ }
+ rhsc.var = nonlocal_id;
+ rhsc.offset = 0;
+ rhsc.type = SCALAR;
+ VEC_safe_push (ce_s, heap, *results, &rhsc);
}
-
/* 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 cases, either a
- GIMPLE_MODIFY_STMT 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;
- tree arg;
- call_expr_arg_iterator iter;
- varinfo_t fi;
- int i = 1;
- tree decl;
- if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
+ if (!in_ipa_mode)
{
- lhsop = GIMPLE_STMT_OPERAND (t, 0);
- rhsop = GIMPLE_STMT_OPERAND (t, 1);
- }
- else
- {
- lhsop = NULL;
- rhsop = t;
- }
- decl = get_callee_fndecl (rhsop);
+ VEC(ce_s, heap) *rhsc = NULL;
+ 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)
- {
- fi = get_vi_for_tree (decl);
+ /* Const functions can return their arguments and addresses
+ of global memory but not of escaped memory. */
+ if (flags & (ECF_CONST|ECF_NOVOPS))
+ {
+ if (gimple_call_lhs (t)
+ && could_have_pointers (gimple_call_lhs (t)))
+ handle_const_call (t, &rhsc);
+ }
+ /* Pure functions can return addresses in and of memory
+ reachable from their arguments, but they are not an escape
+ point for reachable memory of their arguments. */
+ else if (flags & (ECF_PURE|ECF_LOOPING_CONST_OR_PURE))
+ handle_pure_call (t, &rhsc);
+ else
+ handle_rhs_call (t, &rhsc);
+ if (gimple_call_lhs (t)
+ && could_have_pointers (gimple_call_lhs (t)))
+ handle_lhs_call (gimple_call_lhs (t), flags, rhsc);
+ VEC_free (ce_s, heap, rhsc);
}
else
{
- decl = CALL_EXPR_FN (rhsop);
- fi = get_vi_for_tree (decl);
- }
-
- /* Assign all the passed arguments to the appropriate incoming
- parameters of the function. */
-
- FOR_EACH_CALL_EXPR_ARG (arg, iter, rhsop)
- {
- 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++;
}
+ }
+ /* 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 we are returning a value, assign it to the result. */
- if (lhsop)
+ if (rhsop && AGGREGATE_TYPE_P (TREE_TYPE (lhsop)))
+ do_structure_copy (lhsop, rhsop);
+ else
{
- struct constraint_expr rhs;
- struct constraint_expr *lhsp;
- unsigned int j = 0;
-
+ 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)
+ {
+ 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)
{
- 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))
+ gcc_assert (is_gimple_assign (t));
+ if (gimple_assign_rhs_code (t) == ADDR_EXPR)
{
- do_structure_copy (lhsop, rhsop);
+ 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
+ else if (get_gimple_rhs_class (gimple_assign_rhs_code (t))
+ == GIMPLE_SINGLE_RHS)
{
- /* 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_vl_exp:
- 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_OPERAND_LENGTH (rhsop); i++)
- {
- tree op = TREE_OPERAND (rhsop, i);
- unsigned int j;
-
- gcc_assert (VEC_length (ce_s, rhsc) == 0);
- get_constraint_for (op, &rhsc);
- for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
- {
- struct constraint_expr *c2;
- while (VEC_length (ce_s, rhsc) > 0)
- {
- c2 = VEC_last (ce_s, rhsc);
- process_constraint (new_constraint (*c, *c2));
- VEC_pop (ce_s, rhsc);
- }
- }
- }
- }
- }
+ if (could_have_pointers (gimple_assign_rhs1 (t)))
+ make_escape_constraint (gimple_assign_rhs1 (t));
}
+ else
+ gcc_unreachable ();
}
- else if (TREE_CODE (t) == CHANGE_DYNAMIC_TYPE_EXPR)
+ else if (stmt_escape_type == ESCAPE_BAD_CAST)
{
- unsigned int j;
+ 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, noutputs;
+ const char **oconstraints;
+ const char *constraint;
+ bool allows_mem, allows_reg, is_inout;
- get_constraint_for (CHANGE_DYNAMIC_TYPE_LOCATION (t), &lhsc);
- for (j = 0; VEC_iterate (ce_s, lhsc, j, c); ++j)
- get_varinfo (c->var)->no_tbaa_pruning = true;
+ noutputs = gimple_asm_noutputs (t);
+ oconstraints = XALLOCAVEC (const char *, noutputs);
+
+ for (i = 0; i < noutputs; ++i)
+ {
+ tree link = gimple_asm_output_op (t, i);
+ tree op = TREE_VALUE (link);
+
+ constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
+ oconstraints[i] = constraint;
+ parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
+ &allows_reg, &is_inout);
+
+ /* A memory constraint makes the address of the operand escape. */
+ if (!allows_reg && allows_mem)
+ make_escape_constraint (build_fold_addr_expr (op));
+
+ /* The asm may read global memory, so outputs may point to
+ any global memory. */
+ if (op && could_have_pointers (op))
+ {
+ VEC(ce_s, heap) *lhsc = NULL;
+ struct constraint_expr rhsc, *lhsp;
+ unsigned j;
+ get_constraint_for (op, &lhsc);
+ rhsc.var = nonlocal_id;
+ rhsc.offset = 0;
+ rhsc.type = SCALAR;
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhsc));
+ VEC_free (ce_s, heap, lhsc);
+ }
+ }
+ for (i = 0; i < gimple_asm_ninputs (t); ++i)
+ {
+ tree link = gimple_asm_input_op (t, i);
+ tree op = TREE_VALUE (link);
+
+ constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
+
+ parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints,
+ &allows_mem, &allows_reg);
+
+ /* A memory constraint makes the address of the operand escape. */
+ if (!allows_reg && allows_mem)
+ make_escape_constraint (build_fold_addr_expr (op));
+ /* Strictly we'd only need the constraint to ESCAPED if
+ the asm clobbers memory, otherwise using CALLUSED
+ would be enough. */
+ else if (op && could_have_pointers (op))
+ make_escape_constraint (op);
+ }
}
- /* After promoting variables and computing aliasing we will
- need to re-scan most statements. FIXME: Try to minimize the
- number of statements re-scanned. It's not really necessary to
- re-scan *all* statements. */
- mark_stmt_modified (origt);
VEC_free (ce_s, heap, rhsc);
VEC_free (ce_s, heap, lhsc);
}
/* Find the first varinfo in the same variable as START that overlaps with
- OFFSET.
- Effectively, walk the chain of fields for the variable START to find the
- first field that overlaps with OFFSET.
- Return NULL if we can't find one. */
+ OFFSET. Return NULL if we can't find one. */
static varinfo_t
first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
{
- varinfo_t curr = start;
- while (curr)
+ /* If the offset is outside of the variable, bail out. */
+ if (offset >= start->fullsize)
+ return NULL;
+
+ /* If we cannot reach offset from start, lookup the first field
+ and start from there. */
+ if (start->offset > offset)
+ start = lookup_vi_for_tree (start->decl);
+
+ while (start)
{
/* We may not find a variable in the field list with the actual
offset when when we have glommed a structure to a variable.
In that case, however, offset should still be within the size
of the variable. */
- if (offset >= curr->offset && offset < (curr->offset + curr->size))
- return curr;
- curr = curr->next;
+ if (offset >= start->offset
+ && offset < (start->offset + start->size))
+ return start;
+
+ start= start->next;
}
+
return NULL;
}
+/* Find the first varinfo in the same variable as START that overlaps with
+ OFFSET. If there is no such varinfo the varinfo directly preceding
+ OFFSET is returned. */
+
+static varinfo_t
+first_or_preceding_vi_for_offset (varinfo_t start,
+ unsigned HOST_WIDE_INT offset)
+{
+ /* If we cannot reach offset from start, lookup the first field
+ and start from there. */
+ if (start->offset > offset)
+ start = lookup_vi_for_tree (start->decl);
+
+ /* We may not find a variable in the field list with the actual
+ offset when when we have glommed a structure to a variable.
+ In that case, however, offset should still be within the size
+ of the variable.
+ If we got beyond the offset we look for return the field
+ directly preceding offset which may be the last field. */
+ while (start->next
+ && offset >= start->offset
+ && !(offset < (start->offset + start->size)))
+ start = start->next;
+
+ return start;
+}
+
/* Insert the varinfo FIELD into the field list for BASE, at the front
of the list. */
}
}
+/* 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. ADDRESSABLE_TYPE is the type of the outermost object that could have
- its address taken. */
+/* Return true if V is a tree that we can have subvars for.
+ Normally, this is any aggregate type. Also complex
+ types which are not gimple registers can have subvars. */
+
+static inline bool
+var_can_have_subvars (const_tree v)
+{
+ /* Volatile variables should never have subvars. */
+ if (TREE_THIS_VOLATILE (v))
+ return false;
+
+ /* Non decls or memory tags can never have subvars. */
+ if (!DECL_P (v))
+ return false;
+
+ /* Aggregates without overlapping fields can have subvars. */
+ if (TREE_CODE (TREE_TYPE (v)) == RECORD_TYPE)
+ return true;
+
+ return false;
+}
+
+/* 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,
- tree addressable_type)
+ 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;
- real_part->alias_set = -1;
-
- 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;
- img_part->alias_set = -1;
-
- 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,
- TREE_TYPE (type))))
- /* 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);
- pair->alias_set = -1;
- 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_NONADDRESSABLE_P (field)
- ? addressable_type
- : TREE_TYPE (field))))
- && 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);
- if (DECL_NONADDRESSABLE_P (field))
- pair->alias_set = get_alias_set (addressable_type);
+ 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->alias_set = -1;
- count++;
+ {
+ 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 = ADDRESSOF;
process_constraint (new_constraint (lhs, rhs));
}
+/* Create a constraint ID = FROM. */
+
+static void
+make_copy_constraint (varinfo_t vi, int from)
+{
+ struct constraint_expr lhs, rhs;
+
+ lhs.var = vi->id;
+ lhs.offset = 0;
+ lhs.type = SCALAR;
+
+ rhs.var = from;
+ rhs.offset = 0;
+ rhs.type = SCALAR;
+ process_constraint (new_constraint (lhs, rhs));
+}
+
/* Count the number of arguments DECL has, and set IS_VARARGS to true
if it is a varargs function. */
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_vi_for_tree (vi->decl, 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;
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)
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))
{
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,
- decltype);
- 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
vi = new_var_info (decl, index, name);
vi->decl = decl;
vi->offset = 0;
- vi->has_union = hasunion;
+ vi->may_have_pointers = could_have_pointers (decl);
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;
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)
+ && vi->may_have_pointers)
+ {
+ if (var_ann (decl)
+ && var_ann (decl)->noalias_state == NO_ALIAS_ANYTHING)
+ make_constraint_from (vi, vi->id);
+ else
+ make_copy_constraint (vi, nonlocal_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;
+ vi->may_have_pointers = fo->may_have_pointers;
for (i = VEC_length (fieldoff_s, fieldstack) - 1;
i >= 1 && VEC_iterate (fieldoff_s, fieldstack, i, fo);
i--)
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);
newvi->offset = fo->offset;
- newvi->size = TREE_INT_CST_LOW (fo->size);
+ newvi->size = fo->size;
newvi->fullsize = vi->fullsize;
+ newvi->may_have_pointers = fo->may_have_pointers;
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)
+ && newvi->may_have_pointers)
+ make_copy_constraint (newvi, nonlocal_id);
stats.total_vars++;
}
- VEC_free (fieldoff_s, heap, fieldstack);
}
+ else
+ vi->is_full_var = true;
+
+ VEC_free (fieldoff_s, heap, fieldstack);
+
return index;
}
/* Print out the points-to solution for VAR to FILE. */
-void
+static void
dump_solution_for_var (FILE *file, unsigned int var)
{
varinfo_t vi = get_varinfo (var);
struct constraint_expr lhs, rhs;
/* For each incoming pointer argument arg, create the constraint ARG
- = ANYTHING or a dummy variable if flag_argument_noalias is set. */
+ = 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;
if (heapvar == NULL_TREE)
{
var_ann_t ann;
- heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)),
+ heapvar = create_tmp_var_raw (ptr_type_node,
"PARM_NOALIAS");
DECL_EXTERNAL (heapvar) = 1;
if (gimple_referenced_vars (cfun))
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)
vi = get_vi_for_tree (heapvar);
vi->is_artificial_var = 1;
vi->is_heap_var = 1;
+ vi->is_unknown_size_var = true;
+ vi->fullsize = ~0;
+ vi->size = ~0;
rhs.var = vi->id;
rhs.type = ADDRESSOF;
rhs.offset = 0;
varinfo_t arg_vi = get_vi_for_tree (t);
for (p = arg_vi; p; p = p->next)
- make_constraint_from_anything (p);
+ make_constraint_from (p, nonlocal_id);
}
}
+
+ /* Add a constraint for a result decl that is passed by reference. */
+ if (DECL_RESULT (cfun->decl)
+ && DECL_BY_REFERENCE (DECL_RESULT (cfun->decl)))
+ {
+ varinfo_t p, result_vi = get_vi_for_tree (DECL_RESULT (cfun->decl));
+
+ for (p = result_vi; p; p = p->next)
+ make_constraint_from (p, nonlocal_id);
+ }
+
+ /* Add a constraint for the incoming static chain parameter. */
+ if (cfun->static_chain_decl != NULL_TREE)
+ {
+ varinfo_t p, chain_vi = get_vi_for_tree (cfun->static_chain_decl);
+
+ for (p = chain_vi; p; p = p->next)
+ make_constraint_from (p, nonlocal_id);
+ }
}
/* Structure used to put solution bitmaps in a hashtable so they can
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;
static hashval_t
shared_bitmap_hash (const void *p)
{
- const shared_bitmap_info_t bi = (shared_bitmap_info_t) p;
+ const_shared_bitmap_info_t const bi = (const_shared_bitmap_info_t) p;
return bi->hashcode;
}
static int
shared_bitmap_eq (const void *p1, const void *p2)
{
- const shared_bitmap_info_t sbi1 = (shared_bitmap_info_t) p1;
- const shared_bitmap_info_t sbi2 = (shared_bitmap_info_t) 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);
}
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)
{
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);
}
-/* 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.
- 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. */
+/* Set bits in INTO corresponding to the variable uids in solution set FROM.
+ If MEM_ALIAS_SET is not zero, we also use type based alias analysis to
+ prune the points-to sets with this alias-set.
+ Returns the number of pruned variables and updates the vars_contains_global
+ member of *PT . */
-static void
-set_uids_in_ptset (tree ptr, bitmap into, bitmap from, bool is_derefed,
- bool no_tbaa_pruning)
+static unsigned
+set_uids_in_ptset (bitmap into, bitmap from,
+ alias_set_type mem_alias_set, struct pt_solution *pt)
{
unsigned int i;
bitmap_iterator bi;
- subvar_t sv;
- HOST_WIDE_INT ptr_alias_set = get_alias_set (TREE_TYPE (ptr));
+ unsigned pruned = 0;
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
- || TREE_CODE (vi->decl) == RESULT_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))
+ /* 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
+ && !vi->no_tbaa_pruning
+ && mem_alias_set != 0)
{
- /* 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)
+ alias_set_type var_alias_set = get_alias_set (vi->decl);
+ if (mem_alias_set != var_alias_set
+ && !alias_set_subset_of (mem_alias_set, var_alias_set))
{
- var_alias_set = get_alias_set (sft);
- if (no_tbaa_pruning
- || (!is_derefed && !vi->directly_dereferenced)
- || alias_sets_conflict_p (ptr_alias_set, var_alias_set))
- bitmap_set_bit (into, DECL_UID (sft));
- }
- }
- 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));
- else
- {
- var_alias_set = get_alias_set (vi->decl);
- if (no_tbaa_pruning
- || (!is_derefed && !vi->directly_dereferenced)
- || alias_sets_conflict_p (ptr_alias_set, var_alias_set))
- bitmap_set_bit (into, DECL_UID (vi->decl));
+ ++pruned;
+ continue;
}
}
+
+ /* Add the decl to the points-to set. Note that the points-to
+ set contains global variables. */
+ bitmap_set_bit (into, DECL_UID (vi->decl));
+ if (is_global_var (vi->decl))
+ pt->vars_contains_global = true;
}
}
+
+ 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;
+/* Emit a note for the pointer initialization point DEF. */
-/* 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. */
+static void
+emit_pointer_definition (tree ptr, bitmap visited)
+{
+ gimple def = SSA_NAME_DEF_STMT (ptr);
+ if (gimple_code (def) == GIMPLE_PHI)
+ {
+ use_operand_p argp;
+ ssa_op_iter oi;
+
+ 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");
+}
-/* Mark which SMT's are in use by points-to anything variables. */
+/* Emit a strict aliasing warning for dereferencing the pointer PTR. */
-void
-set_used_smts (void)
+static void
+emit_alias_warning (tree ptr)
{
- int i;
- varinfo_t vi;
- used_smts = BITMAP_ALLOC (&pta_obstack);
+ gimple use;
+ imm_use_iterator ui;
+ bool warned = false;
- for (i = 0; VEC_iterate (varinfo_t, varmap, i, vi); i++)
+ FOR_EACH_IMM_USE_STMT (use, ui, ptr)
{
- tree var = vi->decl;
- tree smt;
- 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 || find (vi->id) != 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;
+ tree deref = NULL_TREE;
- 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));
+ if (gimple_has_lhs (use))
+ {
+ tree lhs = get_base_address (gimple_get_lhs (use));
+ if (lhs
+ && INDIRECT_REF_P (lhs)
+ && TREE_OPERAND (lhs, 0) == ptr)
+ deref = lhs;
+ }
+ 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))
+ {
+ TREE_NO_WARNING (deref) = 1;
+ warned |= warning_at (gimple_location (use), OPT_Wstrict_aliasing,
+ "dereferencing pointer %qD does break "
+ "strict-aliasing rules", SSA_NAME_VAR (ptr));
+ }
+ }
+ if (warned)
+ {
+ bitmap visited = BITMAP_ALLOC (NULL);
+ emit_pointer_definition (ptr, visited);
+ BITMAP_FREE (visited);
}
}
-/* Merge the necessary SMT's into the bitmap INTO, which is
- P's varinfo. This involves merging all SMT's that are a subset of
- the SMT necessary for P. */
+/* Compute the points-to solution *PT for the variable VI.
+ Prunes the points-to set based on TBAA rules if DO_TBAA_PRUNING
+ is true. Returns the number of TBAA pruned variables from the
+ points-to set. */
-static void
-merge_smts_into (tree p, bitmap solution)
+static unsigned int
+find_what_var_points_to (varinfo_t vi, struct pt_solution *pt,
+ bool do_tbaa_pruning)
{
- unsigned int i;
+ unsigned int i, pruned;
bitmap_iterator bi;
- tree smt;
- bitmap aliases;
- tree var = p;
+ bitmap finished_solution;
+ bitmap result;
+ tree ptr = vi->decl;
+ alias_set_type mem_alias_set;
+
+ memset (pt, 0, sizeof (struct pt_solution));
- if (TREE_CODE (p) == SSA_NAME)
- var = SSA_NAME_VAR (p);
+ /* This variable may have been collapsed, let's get the real
+ variable. */
+ vi = get_varinfo (find (vi->id));
- smt = var_ann (var)->symbol_mem_tag;
- if (smt)
+ /* Translate artificial variables into SSA_NAME_PTR_INFO
+ attributes. */
+ EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
{
- HOST_WIDE_INT smtset = get_alias_set (TREE_TYPE (smt));
+ varinfo_t vi = get_varinfo (i);
- /* Need to set the SMT subsets first before this
- will work properly. */
- bitmap_set_bit (solution, DECL_UID (smt));
- EXECUTE_IF_SET_IN_BITMAP (used_smts, 0, i, bi)
+ if (vi->is_artificial_var)
{
- tree newsmt = referenced_var (i);
- tree newsmttype = TREE_TYPE (newsmt);
-
- if (alias_set_subset_of (get_alias_set (newsmttype),
- smtset))
- bitmap_set_bit (solution, i);
+ if (vi->id == nothing_id)
+ pt->null = 1;
+ else if (vi->id == escaped_id)
+ pt->escaped = 1;
+ else if (vi->id == callused_id)
+ gcc_unreachable ();
+ else if (vi->id == nonlocal_id)
+ pt->nonlocal = 1;
+ else if (vi->is_heap_var)
+ /* We represent heapvars in the points-to set properly. */
+ ;
+ else if (vi->id == anything_id
+ || vi->id == readonly_id
+ || vi->id == integer_id)
+ pt->anything = 1;
}
+ }
- aliases = MTAG_ALIASES (smt);
- if (aliases)
- bitmap_ior_into (solution, aliases);
+ /* Instead of doing extra work, simply do not create
+ elaborate points-to information for pt_anything pointers. */
+ if (pt->anything)
+ return 0;
+
+ /* Share the final set of variables when possible. */
+ finished_solution = BITMAP_GGC_ALLOC ();
+ stats.points_to_sets_created++;
+
+ if (TREE_CODE (ptr) == SSA_NAME)
+ ptr = SSA_NAME_VAR (ptr);
+
+ /* If the pointer decl is marked that no TBAA is to be applied,
+ do not do tbaa pruning. */
+ if (!do_tbaa_pruning
+ || DECL_NO_TBAA_P (ptr))
+ mem_alias_set = 0;
+ else
+ mem_alias_set = get_deref_alias_set (ptr);
+ pruned = set_uids_in_ptset (finished_solution, vi->solution,
+ mem_alias_set, pt);
+ result = shared_bitmap_lookup (finished_solution);
+ if (!result)
+ {
+ shared_bitmap_add (finished_solution);
+ pt->vars = finished_solution;
+ }
+ else
+ {
+ pt->vars = result;
+ bitmap_clear (finished_solution);
}
+
+ return pruned;
}
-/* Given a pointer variable P, fill in its points-to set, or return
- 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
- 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
- aliases. In such a case, if we did not include the right set of
- SMT's in the points-to set of the variable, we'd end up with
- statements that do not conflict but should. */
+/* Given a pointer variable P, fill in its points-to set. Apply
+ type-based pruning if IS_DEREFERENCED is true. */
-bool
-find_what_p_points_to (tree p)
+static void
+find_what_p_points_to (tree p, bool is_dereferenced)
{
+ struct ptr_info_def *pi;
+ unsigned int pruned;
tree lookup_p = p;
varinfo_t vi;
- if (!have_alias_info)
- return false;
-
/* For parameters, get at the points-to set for the actual parm
decl. */
if (TREE_CODE (p) == SSA_NAME
lookup_p = SSA_NAME_VAR (p);
vi = lookup_vi_for_tree (lookup_p);
- if (vi)
- {
- if (vi->is_artificial_var)
- return false;
+ if (!vi)
+ return;
- /* See if this is a field or a structure. */
- if (vi->size != vi->fullsize)
+ pi = get_ptr_info (p);
+ pruned = find_what_var_points_to (vi, &pi->pt, is_dereferenced);
+
+ if (!(pi->pt.anything || pi->pt.nonlocal || pi->pt.escaped)
+ && bitmap_empty_p (pi->pt.vars)
+ && pruned > 0
+ && is_dereferenced
+ && warn_strict_aliasing > 0
+ && !SSA_NAME_IS_DEFAULT_DEF (p))
+ {
+ if (dump_file && dump_flags & TDF_DETAILS)
{
- /* 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;
+ fprintf (dump_file, "alias warning for ");
+ print_generic_expr (dump_file, p, 0);
+ fprintf (dump_file, "\n");
}
- else
- {
- struct ptr_info_def *pi = get_ptr_info (p);
- unsigned int i;
- bitmap_iterator bi;
- bool was_pt_anything = false;
- bitmap finished_solution;
- bitmap result;
-
- if (!pi->is_dereferenced)
- return false;
+ emit_alias_warning (p);
+ }
+}
- /* This variable may have been collapsed, let's get the real
- variable. */
- vi = get_varinfo (find (vi->id));
- /* Translate artificial variables into SSA_NAME_PTR_INFO
- attributes. */
- EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
- {
- varinfo_t vi = get_varinfo (i);
+/* Query statistics for points-to solutions. */
- if (vi->is_artificial_var)
- {
- /* FIXME. READONLY should be handled better so that
- flow insensitive aliasing can disregard writable
- aliases. */
- if (vi->id == nothing_id)
- pi->pt_null = 1;
- else if (vi->id == anything_id)
- was_pt_anything = 1;
- else if (vi->id == readonly_id)
- was_pt_anything = 1;
- else if (vi->id == integer_id)
- was_pt_anything = 1;
- else if (vi->is_heap_var)
- pi->pt_global_mem = 1;
- }
- }
+static struct {
+ unsigned HOST_WIDE_INT pt_solution_includes_may_alias;
+ unsigned HOST_WIDE_INT pt_solution_includes_no_alias;
+ unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias;
+ unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias;
+} pta_stats;
- /* Share the final set of variables when possible. */
-
- finished_solution = BITMAP_GGC_ALLOC ();
- stats.points_to_sets_created++;
-
- /* Instead of using pt_anything, we merge in the SMT aliases
- for the underlying SMT. In addition, if they could have
- pointed to anything, they could point to global memory.
- But we cannot do that for ref-all pointers because these
- aliases have not been computed yet. */
- if (was_pt_anything)
- {
- if (PTR_IS_REF_ALL (p))
- {
- pi->pt_anything = 1;
- return false;
- }
+void
+dump_pta_stats (FILE *s)
+{
+ fprintf (s, "\nPTA query stats:\n");
+ fprintf (s, " pt_solution_includes: "
+ HOST_WIDE_INT_PRINT_DEC" disambiguations, "
+ HOST_WIDE_INT_PRINT_DEC" queries\n",
+ pta_stats.pt_solution_includes_no_alias,
+ pta_stats.pt_solution_includes_no_alias
+ + pta_stats.pt_solution_includes_may_alias);
+ fprintf (s, " pt_solutions_intersect: "
+ HOST_WIDE_INT_PRINT_DEC" disambiguations, "
+ HOST_WIDE_INT_PRINT_DEC" queries\n",
+ pta_stats.pt_solutions_intersect_no_alias,
+ pta_stats.pt_solutions_intersect_no_alias
+ + pta_stats.pt_solutions_intersect_may_alias);
+}
- merge_smts_into (p, finished_solution);
- pi->pt_global_mem = 1;
- }
-
- set_uids_in_ptset (vi->decl, finished_solution, vi->solution,
- vi->directly_dereferenced,
- vi->no_tbaa_pruning);
- result = shared_bitmap_lookup (finished_solution);
- if (!result)
- {
- shared_bitmap_add (finished_solution);
- pi->pt_vars = finished_solution;
- }
- else
- {
- pi->pt_vars = result;
- bitmap_clear (finished_solution);
- }
+/* Reset the points-to solution *PT to a conservative default
+ (point to anything). */
- if (bitmap_empty_p (pi->pt_vars))
- pi->pt_vars = NULL;
+void
+pt_solution_reset (struct pt_solution *pt)
+{
+ memset (pt, 0, sizeof (struct pt_solution));
+ pt->anything = true;
+}
- return true;
- }
- }
+/* Return true if the points-to solution *PT is empty. */
+
+static bool
+pt_solution_empty_p (struct pt_solution *pt)
+{
+ if (pt->anything
+ || pt->nonlocal)
+ return false;
+
+ if (pt->vars
+ && !bitmap_empty_p (pt->vars))
+ return false;
+
+ /* If the solution includes ESCAPED, check if that is empty. */
+ if (pt->escaped
+ && !pt_solution_empty_p (&cfun->gimple_df->escaped))
+ return false;
+
+ return true;
+}
+
+/* Return true if the points-to solution *PT includes global memory. */
+
+bool
+pt_solution_includes_global (struct pt_solution *pt)
+{
+ if (pt->anything
+ || pt->nonlocal
+ || pt->vars_contains_global)
+ return true;
+
+ if (pt->escaped)
+ return pt_solution_includes_global (&cfun->gimple_df->escaped);
+
+ return false;
+}
+
+/* Return true if the points-to solution *PT includes the variable
+ declaration DECL. */
+
+static bool
+pt_solution_includes_1 (struct pt_solution *pt, const_tree decl)
+{
+ if (pt->anything)
+ return true;
+
+ if (pt->nonlocal
+ && is_global_var (decl))
+ return true;
+
+ if (pt->vars
+ && bitmap_bit_p (pt->vars, DECL_UID (decl)))
+ return true;
+
+ /* If the solution includes ESCAPED, check it. */
+ if (pt->escaped
+ && pt_solution_includes_1 (&cfun->gimple_df->escaped, decl))
+ return true;
return false;
}
+bool
+pt_solution_includes (struct pt_solution *pt, const_tree decl)
+{
+ bool res = pt_solution_includes_1 (pt, decl);
+ if (res)
+ ++pta_stats.pt_solution_includes_may_alias;
+ else
+ ++pta_stats.pt_solution_includes_no_alias;
+ return res;
+}
+
+/* Return true if both points-to solutions PT1 and PT2 have a non-empty
+ intersection. */
+
+static bool
+pt_solutions_intersect_1 (struct pt_solution *pt1, struct pt_solution *pt2)
+{
+ if (pt1->anything || pt2->anything)
+ return true;
+
+ /* If either points to unknown global memory and the other points to
+ any global memory they alias. */
+ if ((pt1->nonlocal
+ && (pt2->nonlocal
+ || pt2->vars_contains_global))
+ || (pt2->nonlocal
+ && pt1->vars_contains_global))
+ return true;
+
+ /* Check the escaped solution if required. */
+ if ((pt1->escaped || pt2->escaped)
+ && !pt_solution_empty_p (&cfun->gimple_df->escaped))
+ {
+ /* If both point to escaped memory and that solution
+ is not empty they alias. */
+ if (pt1->escaped && pt2->escaped)
+ return true;
+
+ /* If either points to escaped memory see if the escaped solution
+ intersects with the other. */
+ if ((pt1->escaped
+ && pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt2))
+ || (pt2->escaped
+ && pt_solutions_intersect_1 (&cfun->gimple_df->escaped, pt1)))
+ return true;
+ }
+
+ /* Now both pointers alias if their points-to solution intersects. */
+ return (pt1->vars
+ && pt2->vars
+ && bitmap_intersect_p (pt1->vars, pt2->vars));
+}
+
+bool
+pt_solutions_intersect (struct pt_solution *pt1, struct pt_solution *pt2)
+{
+ bool res = pt_solutions_intersect_1 (pt1, pt2);
+ if (res)
+ ++pta_stats.pt_solutions_intersect_may_alias;
+ else
+ ++pta_stats.pt_solutions_intersect_no_alias;
+ return res;
+}
/* Dump points-to information to OUTFILE. */
-void
+static void
dump_sa_points_to_info (FILE *outfile)
{
unsigned int 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");
+ 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");
+ anything_tree = create_tmp_var_raw (ptr_type_node, "ANYTHING");
+ 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->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,
/* 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");
+ readonly_tree = create_tmp_var_raw (ptr_type_node, "READONLY");
+ 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->next = NULL;
var_readonly->is_special_var = 1;
insert_vi_for_tree (readonly_tree, var_readonly);
- readonly_id = 2;
VEC_safe_push (varinfo_t, heap, varmap, var_readonly);
/* readonly memory points to anything, in order to make deref
lhs.var = readonly_id;
lhs.offset = 0;
rhs.type = ADDRESSOF;
- rhs.var = anything_id;
+ rhs.var = readonly_id; /* FIXME */
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+
+ /* Create the ESCAPED variable, used to represent the set of escaped
+ memory. */
+ escaped_tree = create_tmp_var_raw (ptr_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);
+
+ /* Create the NONLOCAL variable, used to represent the set of nonlocal
+ memory. */
+ nonlocal_tree = create_tmp_var_raw (ptr_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);
+
+ /* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
+ lhs.type = SCALAR;
+ lhs.var = escaped_id;
+ lhs.offset = 0;
+ rhs.type = DEREF;
+ rhs.var = escaped_id;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+
+ /* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
+ whole variable escapes. */
+ lhs.type = SCALAR;
+ lhs.var = escaped_id;
+ lhs.offset = 0;
+ rhs.type = SCALAR;
+ rhs.var = escaped_id;
+ rhs.offset = UNKNOWN_OFFSET;
+ process_constraint (new_constraint (lhs, rhs));
+
+ /* *ESCAPED = NONLOCAL. This is true because we have to assume
+ everything pointed to by escaped points to what global memory can
+ point to. */
+ lhs.type = DEREF;
+ lhs.var = escaped_id;
+ lhs.offset = 0;
+ rhs.type = SCALAR;
+ rhs.var = nonlocal_id;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+
+ /* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
+ global memory may point to global memory and escaped memory. */
+ lhs.type = SCALAR;
+ lhs.var = nonlocal_id;
+ lhs.offset = 0;
+ rhs.type = ADDRESSOF;
+ rhs.var = nonlocal_id;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+ rhs.type = ADDRESSOF;
+ rhs.var = escaped_id;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+
+ /* Create the CALLUSED variable, used to represent the set of call-used
+ memory. */
+ callused_tree = create_tmp_var_raw (ptr_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));
+ /* CALLUSED = CALLUSED + UNKNOWN, because if a sub-field is call-used the
+ whole variable is call-used. */
+ lhs.type = SCALAR;
+ lhs.var = callused_id;
+ lhs.offset = 0;
+ rhs.type = SCALAR;
+ rhs.var = callused_id;
+ rhs.offset = UNKNOWN_OFFSET;
process_constraint (new_constraint (lhs, rhs));
+ /* Create the STOREDANYTHING variable, used to represent the set of
+ variables stored to *ANYTHING. */
+ storedanything_tree = create_tmp_var_raw (ptr_type_node, "STOREDANYTHING");
+ var_storedanything = new_var_info (storedanything_tree, storedanything_id,
+ "STOREDANYTHING");
+ insert_vi_for_tree (storedanything_tree, var_storedanything);
+ var_storedanything->is_artificial_var = 1;
+ var_storedanything->offset = 0;
+ var_storedanything->size = ~0;
+ var_storedanything->fullsize = ~0;
+ var_storedanything->is_special_var = 0;
+ VEC_safe_push (varinfo_t, heap, varmap, var_storedanything);
+
/* 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");
+ to what an INTEGER "points to". */
+ integer_tree = create_tmp_var_raw (ptr_type_node, "INTEGER");
+ 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->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
static void
init_alias_vars (void)
{
+ use_field_sensitive = (MAX_FIELDS_FOR_FIELD_SENSITIVE > 1);
+
bitmap_obstack_initialize (&pta_obstack);
bitmap_obstack_initialize (&oldpta_obstack);
bitmap_obstack_initialize (&predbitmap_obstack);
struct topo_info *ti = init_topo_info ();
++stats.iterations;
- bitmap_obstack_initialize (&iteration_obstack);
-
compute_topo_order (graph, ti);
while (VEC_length (unsigned, ti->topo_order) != 0)
}
free_topo_info (ti);
- bitmap_obstack_release (&iteration_obstack);
}
sbitmap_free (changed);
}
}
+/* Initialize the heapvar for statement mapping. */
+
+static void
+init_alias_heapvars (void)
+{
+ if (!heapvar_for_stmt)
+ heapvar_for_stmt = htab_create_ggc (11, tree_map_hash, tree_map_eq,
+ NULL);
+}
+
+/* Delete the heapvar for statement mapping. */
+
+void
+delete_alias_heapvars (void)
+{
+ if (heapvar_for_stmt)
+ htab_delete (heapvar_for_stmt);
+ heapvar_for_stmt = NULL;
+}
+
/* Create points-to sets for the current function. See the comments
at the start of the file for an algorithmic overview. */
-void
-compute_points_to_sets (struct alias_info *ai)
+static void
+compute_points_to_sets (void)
{
struct scc_info *si;
basic_block bb;
+ unsigned i;
+ sbitmap dereferenced_ptrs;
timevar_push (TV_TREE_PTA);
intra_create_variable_infos ();
+ /* A bitmap of SSA_NAME pointers that are dereferenced. This is
+ used to track which points-to sets may be TBAA pruned. */
+ dereferenced_ptrs = sbitmap_alloc (num_ssa_names);
+ sbitmap_zero (dereferenced_ptrs);
+
/* 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 = PHI_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);
- /* 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);
- }
+ if (is_gimple_reg (gimple_phi_result (phi)))
+ find_func_aliases (phi);
}
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- tree stmt = bsi_stmt (bsi);
+ gimple stmt = gsi_stmt (gsi);
+ use_operand_p use_p;
+ ssa_op_iter iter;
- find_func_aliases (stmt);
+ /* Mark dereferenced pointers. This is used by TBAA pruning
+ of the points-to sets and the alias warning machinery. */
+ FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
+ {
+ unsigned num_uses, num_loads, num_stores;
+ tree op = USE_FROM_PTR (use_p);
+
+ if (!POINTER_TYPE_P (TREE_TYPE (op)))
+ continue;
- /* 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);
+ /* Determine whether OP is a dereferenced pointer. */
+ count_uses_and_derefs (op, stmt,
+ &num_uses, &num_loads, &num_stores);
+ if (num_loads + num_stores > 0)
+ SET_BIT (dereferenced_ptrs, SSA_NAME_VERSION (op));
+ }
- /* The information in CHANGE_DYNAMIC_TYPE_EXPR nodes has now
- been captured, and we can remove them. */
- if (TREE_CODE (stmt) == CHANGE_DYNAMIC_TYPE_EXPR)
- bsi_remove (&bsi, true);
- else
- bsi_next (&bsi);
+ find_func_aliases (stmt);
}
}
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);
- move_complex_constraints (graph, si);
- free_var_substitution_info (si);
+
+ if (dump_file)
+ fprintf (dump_file, "Rewriting constraints and unifying "
+ "variables\n");
+ rewrite_constraints (graph, si);
build_succ_graph ();
+ free_var_substitution_info (si);
+
+ if (dump_file && (dump_flags & TDF_GRAPH))
+ dump_constraint_graph (dump_file);
+
+ move_complex_constraints (graph);
+
+ if (dump_file)
+ fprintf (dump_file, "Uniting pointer but not location equivalent "
+ "variables\n");
+ unite_pointer_equivalences (graph);
+
+ if (dump_file)
+ fprintf (dump_file, "Finding indirect cycles\n");
find_indirect_cycles (graph);
/* Implicit nodes and predecessors are no longer necessary at this
remove_preds_and_fake_succs (graph);
if (dump_file)
- fprintf (dump_file, "\nSolving graph:\n");
+ fprintf (dump_file, "Solving graph\n");
solve_graph (graph);
if (dump_file)
dump_sa_points_to_info (dump_file);
- have_alias_info = true;
+ /* Compute the points-to sets for ESCAPED and CALLUSED used for
+ call-clobber analysis. */
+ find_what_var_points_to (var_escaped, &cfun->gimple_df->escaped, false);
+ find_what_var_points_to (var_callused, &cfun->gimple_df->callused, false);
+
+ /* Make sure the ESCAPED solution (which is used as placeholder in
+ other solutions) does not reference itself. This simplifies
+ points-to solution queries. */
+ cfun->gimple_df->escaped.escaped = 0;
+
+ /* Compute the points-to sets for pointer SSA_NAMEs. */
+ for (i = 0; i < num_ssa_names; ++i)
+ {
+ tree ptr = ssa_name (i);
+ if (ptr
+ && POINTER_TYPE_P (TREE_TYPE (ptr)))
+ find_what_p_points_to (ptr, TEST_BIT (dereferenced_ptrs, i));
+ }
+ sbitmap_free (dereferenced_ptrs);
timevar_pop (TV_TREE_PTA);
+
+ have_alias_info = true;
}
/* Delete created points-to sets. */
-void
+static void
delete_points_to_sets (void)
{
- varinfo_t v;
- int i;
+ unsigned int i;
htab_delete (shared_bitmap_table);
if (dump_file && (dump_flags & TDF_STATS))
bitmap_obstack_release (&pta_obstack);
VEC_free (constraint_t, heap, constraints);
- for (i = 0; VEC_iterate (varinfo_t, varmap, i, v); i++)
+ for (i = 0; i < graph->size; i++)
VEC_free (constraint_t, heap, graph->complex[i]);
free (graph->complex);
free (graph->rep);
free (graph->succs);
+ free (graph->pe);
+ free (graph->pe_rep);
free (graph->indirect_cycles);
free (graph);
have_alias_info = false;
}
+
+/* Compute points-to information for every SSA_NAME pointer in the
+ current function and compute the transitive closure of escaped
+ variables to re-initialize the call-clobber states of local variables. */
+
+unsigned int
+compute_may_aliases (void)
+{
+ /* For each pointer P_i, determine the sets of variables that P_i may
+ point-to. Compute the reachability set of escaped and call-used
+ variables. */
+ compute_points_to_sets ();
+
+ /* Debugging dumps. */
+ if (dump_file)
+ {
+ dump_alias_info (dump_file);
+
+ if (dump_flags & TDF_DETAILS)
+ dump_referenced_vars (dump_file);
+ }
+
+ /* Deallocate memory used by aliasing data structures and the internal
+ points-to solution. */
+ delete_points_to_sets ();
+
+ gcc_assert (!need_ssa_update_p (cfun));
+
+ return 0;
+}
+
+
+/* A dummy pass to cause points-to information to be computed via
+ TODO_rebuild_alias. */
+
+struct gimple_opt_pass pass_build_alias =
+{
+ {
+ GIMPLE_PASS,
+ "alias", /* name */
+ NULL, /* gate */
+ NULL, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_NONE, /* tv_id */
+ PROP_cfg | PROP_ssa, /* properties_required */
+ PROP_alias, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_rebuild_alias | TODO_dump_func /* todo_flags_finish */
+ }
+};
+
+
/* Return true if we should execute IPA PTA. */
static bool
gate_ipa_pta (void)
{
- return (flag_unit_at_a_time != 0
- && flag_ipa_pta
+ return (flag_ipa_pta
/* Don't bother doing anything if the program has errors. */
&& !(errorcount || sorrycount));
}
for (node = cgraph_nodes; node; node = node->next)
{
- if (!node->analyzed || cgraph_is_master_clone (node))
- {
- unsigned int varid;
+ unsigned int varid;
- varid = create_function_info_for (node->decl,
- cgraph_node_name (node));
- if (node->local.externally_visible)
- {
- varinfo_t fi = get_varinfo (varid);
- for (; fi; fi = fi->next)
- make_constraint_from_anything (fi);
- }
+ varid = create_function_info_for (node->decl,
+ cgraph_node_name (node));
+ if (node->local.externally_visible)
+ {
+ varinfo_t fi = get_varinfo (varid);
+ for (; fi; fi = fi->next)
+ make_constraint_from (fi, anything_id);
}
}
for (node = cgraph_nodes; node; node = node->next)
{
- if (node->analyzed && cgraph_is_master_clone (node))
+ if (node->analyzed)
{
- 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 = PHI_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 ();
}
}
-
-
if (dump_file)
{
fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
"\nCollapsing static cycles and doing variable "
"substitution:\n");
+ init_graph (VEC_length (varinfo_t, varmap) * 2);
build_pred_graph ();
si = perform_var_substitution (graph);
- move_complex_constraints (graph, si);
- free_var_substitution_info (si);
+ rewrite_constraints (graph, si);
build_succ_graph ();
+ free_var_substitution_info (si);
+ move_complex_constraints (graph);
+ unite_pointer_equivalences (graph);
find_indirect_cycles (graph);
/* Implicit nodes and predecessors are no longer necessary at this
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)
-{
- 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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