invoke.texi (-fstrict-aliasing): Document.

	* invoke.texi (-fstrict-aliasing): Document.
	* rtl.texi (MEM_ALIAS_SET): Document.
	* flags.h (flag_strict_aliasing): Declare.
	* toplev.c (flag_strict_aliasing): Define.
	(f_options): Add -strict-aliasing.
	(main): Set flag_strict_aliasing if -O2 or higher.
	* tree.h (tree_type): Add alias_set field.
	(TYPE_ALIAS_SET): New macro.
	(TYPE_ALIAS_SET_KNOWN_P): Likewise.
	(get_alias_set): Declare.
	* tree.c (lang_get_alias_set): Define.
	(make_node): Initialize TYPE_ALIAS_SET.
	(get_alias_set): New function.
	* print-tree.c (print_node): Dump the alias set for a type.
	* c-tree.h (c_get_alias_set): Declare.
	* c-common.c (c_get_alias_set): New function.
	* c-decl.c (init_decl_processing): Set lang_get_alias_set.
	* expr.c (protect_from_queue): Propogage alias sets.
	(expand_assignment): Calculate alias set for new MEMs.
	(expand_expr): Likewise.
	* function.c (put_var_into_stack): Likewise.
	(put_reg_into_stack): Likewise.
	(gen_mem_addressof): Likewise.
	(assign_parms): Likewise.
	* stmt.c (expand_decl): Likewise.
	* varasm.c (make_decl_rtl): Eliminate redundant clearing of
	DECL_RTL.  Calculate alias set for new MEMs.
	* rtl.def (REG): Add dummy operand.
	(MEM): Add extra operand to store the MEM_ALIAS_SET.
	* rtl.h (MEM_ALIAS_SET): New macro.
	(gen_rtx_MEM): Declare.
	* emit-rtl.c (gen_rtx_MEM): New function.
	* gengenrtl.c (sepcial_rtx): Make MEMs special.
	* alias.c (CHECK_ALIAS_SETS_FOR_CONSISTENCY): New macro.
	(DIFFERENT_ALIAS_SETS_P): Likewise.
	(canon_rtx): Propogate the alias set to the new MEM.
	(true_dependence): Check the alias sets.
	(anti_dependence): Likewise.
	(output_dependence): Likewise.
	* explow.c (stabilize): Progoate alias sets.
	* integrate.c (copy_rtx_and_substitute): Likewise.
	* final.c (alter_subreg): Make sure not to leave MEM_IN_STRUCT_P
	in an unpredictable state.  Propogate alias sets.
	* reload1.c (reload): Clear MEM_ALIAS_SET for new MEMs about which
	we have no alias information.

From-SVN: r20719

1 files changed, 15 insertions, 0 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index 62b3168..be62730 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -776,6 +776,18 @@ struct tree_block
 #define TYPE_OBSTACK(NODE) (TYPE_CHECK (NODE)->type.obstack)
 #define TYPE_LANG_SPECIFIC(NODE) (TYPE_CHECK (NODE)->type.lang_specific)
 
+/* The (language-specific) typed-based alias set for this type.
+   Objects whose TYPE_ALIAS_SETs are different cannot alias each
+   other.  If the TYPE_ALIAS_SET is -1, no alias set has yet been
+   assigned to this type.  If the TYPE_ALIAS_SET is 0, objects of this
+   type can alias objects of any type.  */
+#define TYPE_ALIAS_SET(NODE) (TYPE_CHECK (NODE)->type.alias_set)
+
+/* Nonzero iff the typed-based alias set for this type has been
+   calculated.  */
+#define TYPE_ALIAS_SET_KNOWN_P(NODE) \
+  (TYPE_CHECK (NODE)->type.alias_set != -1)
+
 /* A TREE_LIST of IDENTIFIER nodes of the attributes that apply
    to this type.  */
 #define TYPE_ATTRIBUTES(NODE) (TYPE_CHECK (NODE)->type.attributes)
@@ -870,6 +882,7 @@ struct tree_type
   union tree_node *noncopied_parts;
   union tree_node *context;
   struct obstack *obstack;
+  int alias_set;
   /* Points to a structure whose details depend on the language in use.  */
   struct lang_type *lang_specific;
 };
@@ -1811,6 +1824,8 @@ extern tree get_file_function_name		PROTO((int));
 extern tree get_set_constructor_bits		PROTO((tree, char *, int));
 extern tree get_set_constructor_bytes		PROTO((tree,
 						       unsigned char *, int));
+extern int get_alias_set                        PROTO((tree));
+extern int (*lang_get_alias_set)                PROTO((tree));
 
 /* In stmt.c */