/* True if this is a heap variable. */
unsigned int is_heap_var:1;
+ /* True if we may not use TBAA to prune references to this
+ variable. This is used for C++ placement new. */
+ unsigned int no_tbaa_pruning : 1;
+
/* Points-to set for this variable. */
bitmap solution;
struct tree_map *h, in;
in.base.from = from;
- h = htab_find_with_hash (heapvar_for_stmt, &in, htab_hash_pointer (from));
+ h = (struct tree_map *) htab_find_with_hash (heapvar_for_stmt, &in,
+ htab_hash_pointer (from));
if (h)
return h->to;
return NULL_TREE;
struct tree_map *h;
void **loc;
- h = ggc_alloc (sizeof (struct tree_map));
+ h = GGC_NEW (struct tree_map);
h->hash = htab_hash_pointer (from);
h->base.from = from;
h->to = to;
static varinfo_t
new_var_info (tree t, unsigned int id, const char *name)
{
- varinfo_t ret = pool_alloc (variable_info_pool);
+ varinfo_t ret = (varinfo_t) pool_alloc (variable_info_pool);
+ tree var;
ret->id = id;
ret->name = name;
ret->is_special_var = false;
ret->is_unknown_size_var = false;
ret->has_union = false;
+ var = t;
+ if (TREE_CODE (var) == SSA_NAME)
+ var = SSA_NAME_VAR (var);
+ ret->no_tbaa_pruning = (DECL_P (var)
+ && POINTER_TYPE_P (TREE_TYPE (var))
+ && DECL_NO_TBAA_P (var));
ret->solution = BITMAP_ALLOC (&pta_obstack);
ret->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
ret->next = NULL;
new_constraint (const struct constraint_expr lhs,
const struct constraint_expr rhs)
{
- constraint_t ret = pool_alloc (constraint_pool);
+ constraint_t ret = (constraint_t) pool_alloc (constraint_pool);
ret->lhs = lhs;
ret->rhs = rhs;
return ret;
merge_graph_nodes (graph, to, from);
merge_node_constraints (graph, to, from);
+ if (get_varinfo (from)->no_tbaa_pruning)
+ get_varinfo (to)->no_tbaa_pruning = true;
+
if (update_changed && TEST_BIT (changed, from))
{
RESET_BIT (changed, from);
}
/* Handle the structure copy case where we have a structure copy
- between a aggregate on the RHS and a dereference of a pointer on
+ between an aggregate on the RHS and a dereference of a pointer on
the LHS that is of SIZE (in bits)
For each field of the rhs variable (rhsfield)
unsigned int i = 0;
unsigned int j = 0;
VEC (ce_s, heap) *temp = NULL;
- unsigned int rhsoffset = 0;
+ unsigned HOST_WIDE_INT rhsoffset = 0;
- if (TREE_CODE (expr) != PLUS_EXPR
- && TREE_CODE (expr) != MINUS_EXPR)
+ if (TREE_CODE (expr) != POINTER_PLUS_EXPR)
return false;
op0 = TREE_OPERAND (expr, 0);
op1 = TREE_OPERAND (expr, 1);
+ gcc_assert (POINTER_TYPE_P (TREE_TYPE (op0)));
get_constraint_for (op0, &temp);
- if (POINTER_TYPE_P (TREE_TYPE (op0))
- && TREE_CODE (op1) == INTEGER_CST
- && TREE_CODE (expr) == PLUS_EXPR)
+
+ /* We can only handle positive offsets that do not overflow
+ if we multiply it by BITS_PER_UNIT. */
+ if (host_integerp (op1, 1))
{
rhsoffset = TREE_INT_CST_LOW (op1) * BITS_PER_UNIT;
- }
- else
- return false;
+ if (rhsoffset / BITS_PER_UNIT != TREE_INT_CST_LOW (op1))
+ return false;
+ }
for (i = 0; VEC_iterate (ce_s, lhsc, i, c); i++)
for (j = 0; VEC_iterate (ce_s, temp, j, c2); j++)
}
}
}
+ else if (TREE_CODE (t) == CHANGE_DYNAMIC_TYPE_EXPR)
+ {
+ unsigned int j;
+
+ 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;
+ }
/* After promoting variables and computing aliasing we will
need to re-scan most statements. FIXME: Try to minimize the
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. */
+ TYPE. ADDRESSABLE_TYPE is the type of the outermost object that could have
+ its address taken. */
int
push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
- HOST_WIDE_INT offset, bool *has_union)
+ HOST_WIDE_INT offset, bool *has_union,
+ tree addressable_type)
{
tree field;
int count = 0;
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;
}
push = true;
else if (!(pushed = push_fields_onto_fieldstack
(TREE_TYPE (type), fieldstack,
- offset + i * TREE_INT_CST_LOW (elsz), has_union)))
+ 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 */
pair->size = elsz;
pair->decl = NULL_TREE;
pair->offset = offset + i * TREE_INT_CST_LOW (elsz);
+ pair->alias_set = -1;
count++;
}
else
push = true;
else if (!(pushed = push_fields_onto_fieldstack
(TREE_TYPE (field), fieldstack,
- offset + bitpos_of_field (field), has_union))
+ 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
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);
+ else
+ pair->alias_set = -1;
count++;
}
else
|| TREE_CODE (decltype) == QUAL_UNION_TYPE;
if (var_can_have_subvars (decl) && use_field_sensitive && !hasunion)
{
- push_fields_onto_fieldstack (decltype, &fieldstack, 0, &hasunion);
+ push_fields_onto_fieldstack (decltype, &fieldstack, 0, &hasunion,
+ decltype);
if (hasunion)
{
VEC_free (fieldoff_s, heap, fieldstack);
{
fprintf (file, "%s ", get_varinfo (i)->name);
}
- fprintf (file, "}\n");
+ fprintf (file, "}");
+ if (vi->no_tbaa_pruning)
+ fprintf (file, " no-tbaa-pruning");
+ fprintf (file, "\n");
}
}
/* 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. */
+ 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. */
static void
-set_uids_in_ptset (tree ptr, bitmap into, bitmap from)
+set_uids_in_ptset (tree ptr, bitmap into, bitmap from, bool is_derefed,
+ bool no_tbaa_pruning)
{
unsigned int i;
bitmap_iterator bi;
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) == PARM_DECL
+ || TREE_CODE (vi->decl) == RESULT_DECL)
{
if (var_can_have_subvars (vi->decl)
&& get_subvars_for_var (vi->decl))
if (sft)
{
var_alias_set = get_alias_set (sft);
- if (!vi->directly_dereferenced
+ 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
{
var_alias_set = get_alias_set (vi->decl);
- if (!vi->directly_dereferenced
+ 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));
}
finished_solution = BITMAP_GGC_ALLOC ();
stats.points_to_sets_created++;
- /* Instead of using pt_anything, we instead merge in the SMT
- aliases for the underlying SMT. */
+ /* 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;
+ }
+
merge_smts_into (p, finished_solution);
pi->pt_global_mem = 1;
}
- set_uids_in_ptset (vi->decl, finished_solution, vi->solution);
+ 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)
/* Now reallocate the size of the successor list as, and blow away
the predecessor bitmaps. */
graph->size = VEC_length (varinfo_t, varmap);
- graph->succs = xrealloc (graph->succs, graph->size * sizeof (bitmap));
+ graph->succs = XRESIZEVEC (bitmap, graph->succs, graph->size);
free (graph->implicit_preds);
graph->implicit_preds = NULL;
bitmap_obstack_release (&predbitmap_obstack);
}
+/* Compute the set of variables we can't TBAA prune. */
+
+static void
+compute_tbaa_pruning (void)
+{
+ unsigned int size = VEC_length (varinfo_t, varmap);
+ unsigned int i;
+ bool any;
+
+ changed_count = 0;
+ changed = sbitmap_alloc (size);
+ sbitmap_zero (changed);
+
+ /* Mark all initial no_tbaa_pruning nodes as changed. */
+ any = false;
+ for (i = 0; i < size; ++i)
+ {
+ varinfo_t ivi = get_varinfo (i);
+
+ if (find (i) == i && ivi->no_tbaa_pruning)
+ {
+ any = true;
+ if ((graph->succs[i] && !bitmap_empty_p (graph->succs[i]))
+ || VEC_length (constraint_t, graph->complex[i]) > 0)
+ {
+ SET_BIT (changed, i);
+ ++changed_count;
+ }
+ }
+ }
+
+ while (changed_count > 0)
+ {
+ struct topo_info *ti = init_topo_info ();
+ ++stats.iterations;
+
+ bitmap_obstack_initialize (&iteration_obstack);
+
+ compute_topo_order (graph, ti);
+
+ while (VEC_length (unsigned, ti->topo_order) != 0)
+ {
+ bitmap_iterator bi;
+
+ i = VEC_pop (unsigned, ti->topo_order);
+
+ /* If this variable is not a representative, skip it. */
+ if (find (i) != i)
+ continue;
+
+ /* If the node has changed, we need to process the complex
+ constraints and outgoing edges again. */
+ if (TEST_BIT (changed, i))
+ {
+ unsigned int j;
+ constraint_t c;
+ VEC(constraint_t,heap) *complex = graph->complex[i];
+
+ RESET_BIT (changed, i);
+ --changed_count;
+
+ /* Process the complex copy constraints. */
+ for (j = 0; VEC_iterate (constraint_t, complex, j, c); ++j)
+ {
+ if (c->lhs.type == SCALAR && c->rhs.type == SCALAR)
+ {
+ varinfo_t lhsvi = get_varinfo (find (c->lhs.var));
+
+ if (!lhsvi->no_tbaa_pruning)
+ {
+ lhsvi->no_tbaa_pruning = true;
+ if (!TEST_BIT (changed, lhsvi->id))
+ {
+ SET_BIT (changed, lhsvi->id);
+ ++changed_count;
+ }
+ }
+ }
+ }
+
+ /* Propagate to all successors. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i], 0, j, bi)
+ {
+ unsigned int to = find (j);
+ varinfo_t tovi = get_varinfo (to);
+
+ /* Don't propagate to ourselves. */
+ if (to == i)
+ continue;
+
+ if (!tovi->no_tbaa_pruning)
+ {
+ tovi->no_tbaa_pruning = true;
+ if (!TEST_BIT (changed, to))
+ {
+ SET_BIT (changed, to);
+ ++changed_count;
+ }
+ }
+ }
+ }
+ }
+
+ free_topo_info (ti);
+ bitmap_obstack_release (&iteration_obstack);
+ }
+
+ sbitmap_free (changed);
+
+ if (any)
+ {
+ for (i = 0; i < size; ++i)
+ {
+ varinfo_t ivi = get_varinfo (i);
+ varinfo_t ivip = get_varinfo (find (i));
+
+ if (ivip->no_tbaa_pruning)
+ {
+ tree var = ivi->decl;
+
+ if (TREE_CODE (var) == SSA_NAME)
+ var = SSA_NAME_VAR (var);
+
+ if (POINTER_TYPE_P (TREE_TYPE (var)))
+ {
+ DECL_NO_TBAA_P (var) = 1;
+
+ /* Tell the RTL layer that this pointer can alias
+ anything. */
+ DECL_POINTER_ALIAS_SET (var) = 0;
+ }
+ }
+ }
+ }
+}
+
/* Create points-to sets for the current function. See the comments
at the start of the file for an algorithmic overview. */
block_stmt_iterator bsi;
tree phi;
- for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
+ for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
{
if (is_gimple_reg (PHI_RESULT (phi)))
{
}
}
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
{
tree stmt = bsi_stmt (bsi);
This is used when creating name tags and alias
sets. */
update_alias_info (stmt, ai);
+
+ /* 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);
}
}
solve_graph (graph);
+ compute_tbaa_pruning ();
+
if (dump_file)
dump_sa_points_to_info (dump_file);
block_stmt_iterator bsi;
tree phi;
- for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
+ for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
{
if (is_gimple_reg (PHI_RESULT (phi)))
{
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