return change_address (ref, GET_MODE (ref), XEXP (ref, 0));
}
\f
+/* Given REF, either a MEM or a REG, and T, either the type of X or
+ the expression corresponding to REF, set RTX_UNCHANGING_P if
+ appropriate. */
+
+void
+maybe_set_unchanging (ref, t)
+ rtx ref;
+ tree t;
+{
+ /* We can set RTX_UNCHANGING_P from TREE_READONLY for decls whose
+ initialization is only executed once, or whose initializer always
+ has the same value. Currently we simplify this to PARM_DECLs in the
+ first case, and decls with TREE_CONSTANT initializers in the second. */
+ if ((TREE_READONLY (t) && DECL_P (t)
+ && (TREE_CODE (t) == PARM_DECL
+ || DECL_INITIAL (t) == NULL_TREE
+ || TREE_CONSTANT (DECL_INITIAL (t))))
+ || TREE_CODE_CLASS (TREE_CODE (t)) == 'c')
+ RTX_UNCHANGING_P (ref) = 1;
+}
+
/* Given REF, a MEM, and T, either the type of X or the expression
corresponding to REF, set the memory attributes. OBJECTP is nonzero
if we are making a new object of this type. */
/* Get the alias set from the expression or type (perhaps using a
front-end routine) and then copy bits from the type. */
+
+ /* It is incorrect to set RTX_UNCHANGING_P from TREE_READONLY (type)
+ here, because, in C and C++, the fact that a location is accessed
+ through a const expression does not mean that the value there can
+ never change. */
MEM_ALIAS_SET (ref) = get_alias_set (t);
- RTX_UNCHANGING_P (ref) = TYPE_READONLY (type);
MEM_VOLATILE_P (ref) = TYPE_VOLATILE (type);
MEM_IN_STRUCT_P (ref) = AGGREGATE_TYPE_P (type);
if (TYPE_P (t))
return;
- if (TREE_READONLY (t) || TREE_CODE_CLASS (TREE_CODE (t)) == 'c')
- RTX_UNCHANGING_P (ref) = 1;
+ maybe_set_unchanging (ref, t);
if (TREE_THIS_VOLATILE (t))
MEM_VOLATILE_P (ref) = 1;
extern rtx validize_mem PARAMS ((rtx));
#ifdef TREE_CODE
+/* Given REF, either a MEM or a REG, and T, either the type of X or
+ the expression corresponding to REF, set RTX_UNCHANGING_P if
+ appropriate. */
+extern void maybe_set_unchanging PARAMS ((rtx, tree));
+
/* Given REF, a MEM, and T, either the type of X or the expression
corresponding to REF, set the memory attributes. OBJECTP is nonzero
if we are making a new object of this type. */
if (POINTER_TYPE_P (type))
mark_reg_pointer (DECL_RTL (decl),
TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
-
- if (TREE_READONLY (decl))
- RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
+
+ maybe_set_unchanging (DECL_RTL (decl), decl);
}
else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST