/* Miscellaneous SSA utility functions.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008 Free Software
- Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
+ Free Software Foundation, Inc.
This file is part of GCC.
void
redirect_edge_var_map_dup (edge newe, edge olde)
{
- void **new_slot, **old_slot; edge_var_map_vector head;
+ void **new_slot, **old_slot;
+ edge_var_map_vector head;
if (!edge_var_maps)
return;
return (edge_var_map_vector) *slot;
}
+/* Used by redirect_edge_var_map_destroy to free all memory. */
+
+static bool
+free_var_map_entry (const void *key ATTRIBUTE_UNUSED,
+ void **value,
+ void *data ATTRIBUTE_UNUSED)
+{
+ edge_var_map_vector head = (edge_var_map_vector) *value;
+ VEC_free (edge_var_map, heap, head);
+ return true;
+}
/* Clear the edge variable mappings. */
{
if (edge_var_maps)
{
+ pointer_map_traverse (edge_var_maps, free_var_map_entry, NULL);
pointer_map_destroy (edge_var_maps);
edge_var_maps = NULL;
}
static bool
useless_type_conversion_p_1 (tree outer_type, tree inner_type)
{
- /* Qualifiers on value types do not matter. */
+ /* Do the following before stripping toplevel qualifiers. */
+ if (POINTER_TYPE_P (inner_type)
+ && POINTER_TYPE_P (outer_type))
+ {
+ /* Do not lose casts to restrict qualified pointers. */
+ if ((TYPE_RESTRICT (outer_type)
+ != TYPE_RESTRICT (inner_type))
+ && TYPE_RESTRICT (outer_type))
+ return false;
+ }
+
+ /* From now on qualifiers on value types do not matter. */
inner_type = TYPE_MAIN_VARIANT (inner_type);
outer_type = TYPE_MAIN_VARIANT (outer_type);
{
/* Don't lose casts between pointers to volatile and non-volatile
qualified types. Doing so would result in changing the semantics
- of later accesses. */
- if ((TYPE_VOLATILE (TREE_TYPE (outer_type))
- != TYPE_VOLATILE (TREE_TYPE (inner_type)))
+ of later accesses. For function types the volatile qualifier
+ is used to indicate noreturn functions. */
+ if (TREE_CODE (TREE_TYPE (outer_type)) != FUNCTION_TYPE
+ && TREE_CODE (TREE_TYPE (outer_type)) != METHOD_TYPE
+ && TREE_CODE (TREE_TYPE (inner_type)) != FUNCTION_TYPE
+ && TREE_CODE (TREE_TYPE (inner_type)) != METHOD_TYPE
+ && (TYPE_VOLATILE (TREE_TYPE (outer_type))
+ != TYPE_VOLATILE (TREE_TYPE (inner_type)))
&& TYPE_VOLATILE (TREE_TYPE (outer_type)))
return false;
/* We do not care for const qualification of the pointed-to types
as const qualification has no semantic value to the middle-end. */
- /* Do not lose casts to restrict qualified pointers. */
- if ((TYPE_RESTRICT (outer_type)
- != TYPE_RESTRICT (inner_type))
- && TYPE_RESTRICT (outer_type))
- return false;
-
/* Otherwise pointers/references are equivalent if their pointed
to types are effectively the same. We can strip qualifiers
on pointed-to types for further comparison, which is done in
/* Recurse for complex types. */
else if (TREE_CODE (inner_type) == COMPLEX_TYPE
&& TREE_CODE (outer_type) == COMPLEX_TYPE)
- return useless_type_conversion_p_1 (TREE_TYPE (outer_type),
- TREE_TYPE (inner_type));
+ return useless_type_conversion_p (TREE_TYPE (outer_type),
+ TREE_TYPE (inner_type));
/* Recurse for vector types with the same number of subparts. */
else if (TREE_CODE (inner_type) == VECTOR_TYPE
&& TREE_CODE (outer_type) == VECTOR_TYPE
&& TYPE_PRECISION (inner_type) == TYPE_PRECISION (outer_type))
- return useless_type_conversion_p_1 (TREE_TYPE (outer_type),
- TREE_TYPE (inner_type));
+ return useless_type_conversion_p (TREE_TYPE (outer_type),
+ TREE_TYPE (inner_type));
/* For aggregates we may need to fall back to structural equality
checks. */
if (TREE_NO_WARNING (var))
return;
+ /* Do not warn if it can be initialized outside this module. */
+ if (is_global_var (var))
+ return;
+
location = (context != NULL && gimple_has_location (context))
? gimple_location (context)
: DECL_SOURCE_LOCATION (var);
struct walk_data *data = (struct walk_data *) wi->info;
tree t = *tp;
+ /* We do not care about LHS. */
+ if (wi->is_lhs)
+ return NULL_TREE;
+
switch (TREE_CODE (t))
{
+ case ADDR_EXPR:
+ /* Taking the address of an uninitialized variable does not
+ count as using it. */
+ *walk_subtrees = 0;
+ break;
+
+ case VAR_DECL:
+ {
+ /* A VAR_DECL in the RHS of a gimple statement may mean that
+ this variable is loaded from memory. */
+ use_operand_p vuse;
+ tree op;
+
+ /* If there is not gimple stmt,
+ or alias information has not been computed,
+ then we cannot check VUSE ops. */
+ if (data->stmt == NULL
+ || !gimple_aliases_computed_p (cfun))
+ return NULL_TREE;
+
+ /* If the load happens as part of a call do not warn about it. */
+ if (is_gimple_call (data->stmt))
+ return NULL_TREE;
+
+ vuse = SINGLE_SSA_USE_OPERAND (data->stmt, SSA_OP_VUSE);
+ if (vuse == NULL_USE_OPERAND_P)
+ return NULL_TREE;
+
+ op = USE_FROM_PTR (vuse);
+ if (t != SSA_NAME_VAR (op)
+ || !SSA_NAME_IS_DEFAULT_DEF (op))
+ return NULL_TREE;
+ /* If this is a VUSE of t and it is the default definition,
+ then warn about op. */
+ t = op;
+ /* Fall through into SSA_NAME. */
+ }
+
case SSA_NAME:
/* We only do data flow with SSA_NAMEs, so that's all we
can warn about. */
walk_gimple_op (gsi_stmt (gsi), warn_uninitialized_var, &wi);
}
}
+
+ /* Post-dominator information can not be reliably updated. Free it
+ after the use. */
+
+ free_dominance_info (CDI_POST_DOMINATORS);
return 0;
}
}
};
-/* Compute TREE_ADDRESSABLE for local variables. */
+/* Compute TREE_ADDRESSABLE and DECL_GIMPLE_REG_P for local variables. */
static unsigned int
execute_update_addresses_taken (void)
gimple_stmt_iterator gsi;
basic_block bb;
bitmap addresses_taken = BITMAP_ALLOC (NULL);
+ bitmap not_reg_needs = BITMAP_ALLOC (NULL);
bitmap vars_updated = BITMAP_ALLOC (NULL);
bool update_vops = false;
{
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- bitmap taken = gimple_addresses_taken (gsi_stmt (gsi));
+ const_gimple stmt = gsi_stmt (gsi);
+ enum gimple_code code = gimple_code (stmt);
+ bitmap taken = gimple_addresses_taken (stmt);
+
if (taken)
bitmap_ior_into (addresses_taken, taken);
+
+ /* If we have a call or an assignment, see if the lhs contains
+ a local decl that requires not to be a gimple register. */
+ if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
+ {
+ tree lhs = gimple_get_lhs (stmt);
+ /* A plain decl does not need it set. */
+ if (lhs && handled_component_p (lhs))
+ {
+ var = get_base_address (lhs);
+ if (DECL_P (var))
+ bitmap_set_bit (not_reg_needs, DECL_UID (var));
+ }
+ }
}
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
}
}
- /* When possible, clear ADDRESSABLE bit and mark variable for conversion into
- SSA. */
+ /* When possible, clear ADDRESSABLE bit or set the REGISTER bit
+ and mark variable for conversion into SSA. */
FOR_EACH_REFERENCED_VAR (var, rvi)
- if (!is_global_var (var)
- && TREE_CODE (var) != RESULT_DECL
- && TREE_ADDRESSABLE (var)
- && !bitmap_bit_p (addresses_taken, DECL_UID (var)))
- {
- TREE_ADDRESSABLE (var) = 0;
- if (is_gimple_reg (var))
+ {
+ /* Global Variables, result decls cannot be changed. */
+ if (is_global_var (var)
+ || TREE_CODE (var) == RESULT_DECL
+ || bitmap_bit_p (addresses_taken, DECL_UID (var)))
+ continue;
+
+ if (TREE_ADDRESSABLE (var)
+ /* Do not change TREE_ADDRESSABLE if we need to preserve var as
+ a non-register. Otherwise we are confused and forget to
+ add virtual operands for it. */
+ && (!is_gimple_reg_type (TREE_TYPE (var))
+ || !bitmap_bit_p (not_reg_needs, DECL_UID (var))))
+ {
+ TREE_ADDRESSABLE (var) = 0;
+ if (is_gimple_reg (var))
+ mark_sym_for_renaming (var);
+ update_vops = true;
+ bitmap_set_bit (vars_updated, DECL_UID (var));
+ if (dump_file)
+ {
+ fprintf (dump_file, "No longer having address taken ");
+ print_generic_expr (dump_file, var, 0);
+ fprintf (dump_file, "\n");
+ }
+ }
+ if (!DECL_GIMPLE_REG_P (var)
+ && !bitmap_bit_p (not_reg_needs, DECL_UID (var))
+ && (TREE_CODE (TREE_TYPE (var)) == COMPLEX_TYPE
+ || TREE_CODE (TREE_TYPE (var)) == VECTOR_TYPE))
+ {
+ DECL_GIMPLE_REG_P (var) = 1;
mark_sym_for_renaming (var);
- update_vops = true;
- bitmap_set_bit (vars_updated, DECL_UID (var));
- if (dump_file)
- {
- fprintf (dump_file, "No longer having address taken ");
- print_generic_expr (dump_file, var, 0);
- fprintf (dump_file, "\n");
- }
+ update_vops = true;
+ bitmap_set_bit (vars_updated, DECL_UID (var));
+ if (dump_file)
+ {
+ fprintf (dump_file, "Decl is now a gimple register ");
+ print_generic_expr (dump_file, var, 0);
+ fprintf (dump_file, "\n");
+ }
+ }
}
/* Operand caches needs to be recomputed for operands referencing the updated
&& bitmap_intersect_p (gimple_stored_syms (stmt), vars_updated)))
update_stmt (stmt);
}
+ BITMAP_FREE (not_reg_needs);
BITMAP_FREE (addresses_taken);
BITMAP_FREE (vars_updated);
return 0;
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