/* Scalar Replacement of Aggregates (SRA) converts some structure
references into scalar references, exposing them to the scalar
optimizers.
- Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
Contributed by Diego Novillo <dnovillo@redhat.com>
This file is part of GCC.
*/
+/* The set of todo flags to return from tree_sra. */
+static unsigned int todoflags;
+
/* The set of aggregate variables that are candidates for scalarization. */
static bitmap sra_candidates;
static bitmap sra_type_decomp_cache;
static bitmap sra_type_inst_cache;
-/* One of these structures is created for each candidate aggregate
- and each (accessed) member of such an aggregate. */
+/* One of these structures is created for each candidate aggregate and
+ each (accessed) member or group of members of such an aggregate. */
struct sra_elt
{
/* A tree of the elements. Used when we want to traverse everything. */
struct sra_elt *parent;
+ struct sra_elt *groups;
struct sra_elt *children;
struct sra_elt *sibling;
/* If this element is a root, then this is the VAR_DECL. If this is
a sub-element, this is some token used to identify the reference.
In the case of COMPONENT_REF, this is the FIELD_DECL. In the case
- of an ARRAY_REF, this is the (constant) index. In the case of a
- complex number, this is a zero or one. */
+ of an ARRAY_REF, this is the (constant) index. In the case of an
+ ARRAY_RANGE_REF, this is the (constant) RANGE_EXPR. In the case
+ of a complex number, this is a zero or one. */
tree element;
/* The type of the element. */
/* True if TYPE is scalar. */
bool is_scalar;
+ /* True if this element is a group of members of its parent. */
+ bool is_group;
+
/* True if we saw something about this element that prevents scalarization,
such as non-constant indexing. */
bool cannot_scalarize;
bool visited;
};
+#define IS_ELEMENT_FOR_GROUP(ELEMENT) (TREE_CODE (ELEMENT) == RANGE_EXPR)
+
+#define FOR_EACH_ACTUAL_CHILD(CHILD, ELT) \
+ for ((CHILD) = (ELT)->is_group \
+ ? next_child_for_group (NULL, (ELT)) \
+ : (ELT)->children; \
+ (CHILD); \
+ (CHILD) = (ELT)->is_group \
+ ? next_child_for_group ((CHILD), (ELT)) \
+ : (CHILD)->sibling)
+
+/* Helper function for above macro. Return next child in group. */
+static struct sra_elt *
+next_child_for_group (struct sra_elt *child, struct sra_elt *group)
+{
+ gcc_assert (group->is_group);
+
+ /* Find the next child in the parent. */
+ if (child)
+ child = child->sibling;
+ else
+ child = group->parent->children;
+
+ /* Skip siblings that do not belong to the group. */
+ while (child)
+ {
+ tree g_elt = group->element;
+ if (TREE_CODE (g_elt) == RANGE_EXPR)
+ {
+ if (!tree_int_cst_lt (child->element, TREE_OPERAND (g_elt, 0))
+ && !tree_int_cst_lt (TREE_OPERAND (g_elt, 1), child->element))
+ break;
+ }
+ else
+ gcc_unreachable ();
+
+ child = child->sibling;
+ }
+
+ return child;
+}
+
/* Random access to the child of a parent is performed by hashing.
This prevents quadratic behavior, and allows SRA to function
reasonably on larger records. */
enum tree_code code = TREE_CODE (type);
return (code == INTEGER_TYPE || code == REAL_TYPE || code == VECTOR_TYPE
|| code == ENUMERAL_TYPE || code == BOOLEAN_TYPE
- || code == CHAR_TYPE || code == POINTER_TYPE || code == OFFSET_TYPE
+ || code == POINTER_TYPE || code == OFFSET_TYPE
|| code == REFERENCE_TYPE);
}
if (elt->cannot_scalarize)
return false;
- for (c = elt->children; c ; c = c->sibling)
+ for (c = elt->children; c; c = c->sibling)
+ if (!can_completely_scalarize_p (c))
+ return false;
+
+ for (c = elt->groups; c; c = c->sibling)
if (!can_completely_scalarize_p (c))
return false;
h = TREE_INT_CST_LOW (t) ^ TREE_INT_CST_HIGH (t);
break;
+ case RANGE_EXPR:
+ h = iterative_hash_expr (TREE_OPERAND (t, 0), 0);
+ h = iterative_hash_expr (TREE_OPERAND (t, 1), h);
+ break;
+
case FIELD_DECL:
/* We can have types that are compatible, but have different member
lists, so we can't hash fields by ID. Use offsets instead. */
/* Integers are not pointer unique, so compare their values. */
return tree_int_cst_equal (ae, be);
+ case RANGE_EXPR:
+ return
+ tree_int_cst_equal (TREE_OPERAND (ae, 0), TREE_OPERAND (be, 0))
+ && tree_int_cst_equal (TREE_OPERAND (ae, 1), TREE_OPERAND (be, 1));
+
case FIELD_DECL:
/* Fields are unique within a record, but not between
compatible records. */
struct sra_elt **slot;
struct sra_elt *elt;
- dummy.parent = parent;
+ if (parent)
+ dummy.parent = parent->is_group ? parent->parent : parent;
+ else
+ dummy.parent = NULL;
dummy.element = child;
slot = (struct sra_elt **) htab_find_slot (sra_map, &dummy, insert);
if (parent)
{
- elt->sibling = parent->children;
- parent->children = elt;
+ if (IS_ELEMENT_FOR_GROUP (elt->element))
+ {
+ elt->is_group = true;
+ elt->sibling = parent->groups;
+ parent->groups = elt;
+ }
+ else
+ {
+ elt->sibling = parent->children;
+ parent->children = elt;
+ }
}
/* If this is a parameter, then if we want to scalarize, we have
return elt;
}
-/* Return true if the ARRAY_REF in EXPR is a constant, in bounds access. */
-
-static bool
-is_valid_const_index (tree expr)
-{
- tree dom, t, index = TREE_OPERAND (expr, 1);
-
- if (TREE_CODE (index) != INTEGER_CST)
- return false;
-
- /* Watch out for stupid user tricks, indexing outside the array.
-
- Careful, we're not called only on scalarizable types, so do not
- assume constant array bounds. We needn't do anything with such
- cases, since they'll be referring to objects that we should have
- already rejected for scalarization, so returning false is fine. */
-
- dom = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (expr, 0)));
- if (dom == NULL)
- return false;
-
- t = TYPE_MIN_VALUE (dom);
- if (!t || TREE_CODE (t) != INTEGER_CST)
- return false;
- if (tree_int_cst_lt (index, t))
- return false;
-
- t = TYPE_MAX_VALUE (dom);
- if (!t || TREE_CODE (t) != INTEGER_CST)
- return false;
- if (tree_int_cst_lt (t, index))
- return false;
-
- return true;
-}
-
/* Create or return the SRA_ELT structure for EXPR if the expression
refers to a scalarizable variable. */
return NULL;
case ARRAY_REF:
- /* We can't scalarize variable array indicies. */
- if (is_valid_const_index (expr))
+ /* We can't scalarize variable array indices. */
+ if (in_array_bounds_p (expr))
child = TREE_OPERAND (expr, 1);
else
return NULL;
break;
+ case ARRAY_RANGE_REF:
+ /* We can't scalarize variable array indices. */
+ if (range_in_array_bounds_p (expr))
+ {
+ tree domain = TYPE_DOMAIN (TREE_TYPE (expr));
+ child = build2 (RANGE_EXPR, integer_type_node,
+ TYPE_MIN_VALUE (domain), TYPE_MAX_VALUE (domain));
+ }
+ else
+ return NULL;
+ break;
+
case COMPONENT_REF:
/* Don't look through unions. */
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) != RECORD_TYPE)
the effort. */
/* ??? Hack. Figure out how to push this into the scan routines
without duplicating too much code. */
- if (!is_valid_const_index (inner))
+ if (!in_array_bounds_p (inner))
{
disable_scalarization = true;
goto use_all;
inner = TREE_OPERAND (inner, 0);
break;
+ case ARRAY_RANGE_REF:
+ if (!range_in_array_bounds_p (inner))
+ {
+ disable_scalarization = true;
+ goto use_all;
+ }
+ /* ??? See above non-constant bounds and stride . */
+ if (TREE_OPERAND (inner, 2) || TREE_OPERAND (inner, 3))
+ goto use_all;
+ inner = TREE_OPERAND (inner, 0);
+ break;
+
case COMPONENT_REF:
/* A reference to a union member constitutes a reference to the
entire union. */
complete outer element, to which walk_tree will bring us next. */
goto use_all;
- case ARRAY_RANGE_REF:
- /* Similarly, a subrange reference is used to modify indexing. Which
- means that the canonical element names that we have won't work. */
- goto use_all;
-
case VIEW_CONVERT_EXPR:
case NOP_EXPR:
/* Similarly, a view/nop explicitly wants to look at an object in a
for (c = elt->children; c ; c = c->sibling)
scan_dump (c);
+
+ for (c = elt->groups; c ; c = c->sibling)
+ scan_dump (c);
}
/* Entry point to phase 2. Scan the entire function, building up
}
else
{
- struct sra_elt *c;
+ struct sra_elt *c, *group;
unsigned int this_uses = elt->n_uses + parent_uses;
unsigned int this_copies = elt->n_copies + parent_copies;
+ /* Consider groups of sub-elements as weighing in favour of
+ instantiation whatever their size. */
+ for (group = elt->groups; group ; group = group->sibling)
+ FOR_EACH_ACTUAL_CHILD (c, group)
+ {
+ c->n_uses += group->n_uses;
+ c->n_copies += group->n_copies;
+ }
+
for (c = elt->children; c ; c = c->sibling)
decide_instantiation_1 (c, this_uses, this_copies);
}
}
}
+/* Return true if there is only one non aggregate field in the record, TYPE.
+ Return false otherwise. */
+
+static bool
+single_scalar_field_in_record_p (tree type)
+{
+ int num_fields = 0;
+ tree field;
+ if (TREE_CODE (type) != RECORD_TYPE)
+ return false;
+
+ for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
+ if (TREE_CODE (field) == FIELD_DECL)
+ {
+ num_fields++;
+
+ if (num_fields == 2)
+ return false;
+
+ if (AGGREGATE_TYPE_P (TREE_TYPE (field)))
+ return false;
+ }
+
+ return true;
+}
+
/* Make one pass across an element tree deciding whether to perform block
or element copies. If we decide on element copies, instantiate all
elements. Return true if there are any instantiated sub-elements. */
struct sra_elt *c;
bool any_inst;
+ /* We shouldn't be invoked on groups of sub-elements as they must
+ behave like their parent as far as block copy is concerned. */
+ gcc_assert (!elt->is_group);
+
/* If scalarization is disabled, respect it. */
if (elt->cannot_scalarize)
{
c->cannot_scalarize = 1;
decide_block_copy (c);
}
+
+ /* Groups behave like their parent. */
+ for (c = elt->groups; c; c = c->sibling)
+ {
+ c->cannot_scalarize = 1;
+ c->use_block_copy = 1;
+ }
+
return false;
}
full_count = count_type_elements (elt->type, false);
inst_count = sum_instantiated_sizes (elt, &inst_size);
+ /* If there is only one scalar field in the record, don't block copy. */
+ if (single_scalar_field_in_record_p (elt->type))
+ use_block_copy = false;
+
/* ??? What to do here. If there are two fields, and we've only
instantiated one, then instantiating the other is clearly a win.
If there are a large number of fields then the size of the copy
|| !type_can_instantiate_all_elements (elt->type)))
use_block_copy = true;
}
+
elt->use_block_copy = use_block_copy;
+ /* Groups behave like their parent. */
+ for (c = elt->groups; c; c = c->sibling)
+ c->use_block_copy = use_block_copy;
+
if (dump_file)
{
fprintf (dump_file, "Using %s for ",
bitmap_and_compl_into (needs_copy_in, &done_head);
}
bitmap_clear (&done_head);
+
+ if (!bitmap_empty_p (sra_candidates))
+ todoflags |= TODO_update_smt_usage;
mark_set_for_renaming (sra_candidates);
else
{
struct sra_elt *c;
- for (c = elt->children; c ; c = c->sibling)
+ FOR_EACH_ACTUAL_CHILD (c, elt)
mark_no_warning (c);
}
+ elt->all_no_warning = true;
}
}
}
case ARRAY_TYPE:
- return build4 (ARRAY_REF, elt->type, base, elt->element, NULL, NULL);
+ todoflags |= TODO_update_smt_usage;
+ if (TREE_CODE (elt->element) == RANGE_EXPR)
+ return build4 (ARRAY_RANGE_REF, elt->type, base,
+ TREE_OPERAND (elt->element, 0), NULL, NULL);
+ else
+ return build4 (ARRAY_REF, elt->type, base, elt->element, NULL, NULL);
case COMPLEX_TYPE:
if (elt->element == integer_zero_node)
}
else
{
- for (c = elt->children; c ; c = c->sibling)
+ FOR_EACH_ACTUAL_CHILD (c, elt)
{
t = generate_one_element_ref (c, unshare_expr (expr));
generate_copy_inout (c, copy_out, t, list_p);
{
struct sra_elt *dc, *sc;
- for (dc = dst->children; dc ; dc = dc->sibling)
+ FOR_EACH_ACTUAL_CHILD (dc, dst)
{
sc = lookup_element (src, dc->element, NULL, NO_INSERT);
gcc_assert (sc);
return;
}
- for (c = elt->children; c ; c = c->sibling)
+ FOR_EACH_ACTUAL_CHILD (c, elt)
generate_element_zero (c, list_p);
if (elt->replacement)
{
case COMPLEX_CST:
case COMPLEX_EXPR:
- for (sub = elt->children; sub ; sub = sub->sibling)
+ FOR_EACH_ACTUAL_CHILD (sub, elt)
{
if (sub->element == integer_zero_node)
t = (init_code == COMPLEX_EXPR
sra_replace (block_stmt_iterator *bsi, tree list)
{
sra_insert_before (bsi, list);
- bsi_remove (bsi);
+ bsi_remove (bsi, false);
if (bsi_end_p (*bsi))
*bsi = bsi_last (bsi->bb);
else
fputc ('.', f);
print_generic_expr (f, elt->element, dump_flags);
}
+ else if (TREE_CODE (elt->element) == RANGE_EXPR)
+ fprintf (f, "["HOST_WIDE_INT_PRINT_DEC".."HOST_WIDE_INT_PRINT_DEC"]",
+ TREE_INT_CST_LOW (TREE_OPERAND (elt->element, 0)),
+ TREE_INT_CST_LOW (TREE_OPERAND (elt->element, 1)));
else
fprintf (f, "[" HOST_WIDE_INT_PRINT_DEC "]",
TREE_INT_CST_LOW (elt->element));
/* Main entry point. */
-static void
+static unsigned int
tree_sra (void)
{
/* Initialize local variables. */
+ todoflags = 0;
gcc_obstack_init (&sra_obstack);
sra_candidates = BITMAP_ALLOC (NULL);
needs_copy_in = BITMAP_ALLOC (NULL);
BITMAP_FREE (sra_type_decomp_cache);
BITMAP_FREE (sra_type_inst_cache);
obstack_free (&sra_obstack, NULL);
+ return todoflags;
}
static bool
TV_TREE_SRA, /* tv_id */
PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
0, /* properties_provided */
- 0, /* properties_destroyed */
+ PROP_smt_usage, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func | TODO_update_ssa
- | TODO_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */
+ TODO_dump_func /* todo_flags_finish */
+ | TODO_update_ssa
+ | TODO_ggc_collect | TODO_verify_ssa,
0 /* letter */
};
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