alias.c (can_address_p): Compnonents are not addressable if the containing type has alias set 0.

* alias.c (can_address_p): Compnonents are not addressable if
	the containing type has alias set 0.
	(get_alias_set): Rework to use STRIP_NOPS.
	Only call front-end routine on object, type, or object with
	NOPs stripped, not inner values.
	Use language hook to call front-end routine.
	* builtins.c (get_memory_rtx): Always call set_mem_attributes.
	(expand_builtin_apply): Call set_mem_align on MEMs we make.
	Don't pass alignment to emit_block_move.
	(expand_builtin_memcpy, expand_builtin_va_copy): Likewise.
	(expand_builtin_memset): Likewise, but for clear_storage.
	* c-common.c (lang_get_alias_set): Renamed to c_common_alias_set
	and remove C++ specific parts.
	* c-common.h (c_common_get_alias_set): Add declaration.
	* c-lang.c (LANG_HOOKS_GET_ALIAS_SET): New macro.
	* calls.c (emit_call_1): Fix typo in sibcall_pop case.
	(save_fixed_argument_area): Call set_mem_align.
	Remove alignment in call to emit_block_move.
	(emit_library_call_value_1, store_one_arg): Likewise.
	(target_for_arg): Remove; disabled long ago.
	* emit-rtl.c (set_mem_attributes): Rework to only call get_mem_attrs
	once and similar cleanups.
	(offset_address): Use proper introductory comment.
	* expr.c (emit_block_move): Use alignment from that of MEM args, not
	from explicit operand; all callers changed.
	(clear_storage): Likewise.
	(expand_assignment): Don't call set_mem_alias_set on to_rtx.
	(store_field): Remove kludge on alias set used for to_rtx.
	(highest_pow2_factor, case *_DIV_EXPR): Never return 0.
	(expand_expr_unaligned): Call set_mem_attributes instead of
	set_mem_alias_set.
	* expr.h (emit_block_move, clear_storage): Remove ALIGN argument.
	* function.c (assign_stack_temp_for_type): Set MEM alignment.
	(expand_function_end): Track MEM attributes of trampolines.
	* ifcvt.c (noce_try_cmove_arith): Set alignment of new MEM.
	* integrate.c (copy_rtx_and_substitute, case CALL): Copy memory
	attributes from original.
	* langhooks.c (lang_hook_default_get_alias_set): New function.
	(hook_get_alias_set_0): New function.
	* langhooks.h (hook_get_alias_set_0): New declaration.
	(lang_hook_default_get_alias_set): Likewise.
	(LANG_HOOKS_GET_ALIAS_SET): New macro; add to initializer.
	* reload1.c (alter_reg): Use adjust_address_nv.
	* rtl.c (get_mode_alignment): Moved to here.
	* rtl.h (MEM_ALIGN): Take default from mode, if not BLKmode, and
	change default if unknown from 1 to BITS_PER_UNIT.
	* stor-layout.c (get_mode_alignment): Remove from here.
	* toplev.h (struct lang_hoks): Add get_alias_set field.
	* tree.h (lang_get_alias_set): Delete declaration.
	* config/arc/arc.c (arc_setup_incoming_varags): Set MEM alignment.
	* config/i386/i386.c (ix86_setup_incoming_varargs): Likewise.
	(ix86_va_arg): Likewise.
	* config/i960/i960.c (i960_setup_incoming_varargs): Likewise.
	* config/pa/pa.c (hppa_builtin_saveregs): Likewise.
	* config/sparc/sparc.c (sparc_va_arg): Likewise.
	* config/rs6000/rs6000.c (setup_incoming_varargs): Likewise.
	(expand_block_move_mem): Remove dead code.
	* cp/cp-lang.c (cxx_get_alias_set): New function.
	Point LANG_HOOKS_GET_ALIAS_SET to it.
	* f/com.c (LANG_HOOKS_GET_ALIAS_SET): New macro.
	(lang_get_alias_set): Delete.
	* java/lang.c (lang_get_alias_set): Deleted.

From-SVN: r46443

gcc/function.c

@@ -5018,15 +5018,8 @@ assign_parms (fndecl)
       if (parm == function_result_decl)
 	{
 	  tree result = DECL_RESULT (fndecl);
-	  rtx addr = DECL_RTL (parm);
-	  rtx x;
+	  rtx x = gen_rtx_MEM (DECL_MODE (result), DECL_RTL (parm));
 
-#ifdef POINTERS_EXTEND_UNSIGNED
-	  if (GET_MODE (addr) != Pmode)
-	    addr = convert_memory_address (Pmode, addr);
-#endif
-
-	  x = gen_rtx_MEM (DECL_MODE (result), addr);
 	  set_mem_attributes (x, result, 1);
 	  SET_DECL_RTL (result, x);
 	}