+2005-07-26 Richard Guenther <rguenther@suse.de>
+
+ PR tree-optimization/22486
+ * fold-const.c (fold_unary): Fold away useless component
+ references of the form (T *)&T.x, if the address
+ doesn't change.
+
2005-07-25 James E Wilson <wilson@specifixinc.com>
* dwarf2out.c (add_call_src_coords_attributes): New.
return fold_build1 (code, type, TREE_OPERAND (op0, 0));
}
+ /* Handle (T *)&A.B.C for A being of type T and B and C
+ living at offset zero. This occours frequently in
+ C++ upcasting and then accessing the base. */
+ if (TREE_CODE (op0) == ADDR_EXPR
+ && POINTER_TYPE_P (type)
+ && handled_component_p (TREE_OPERAND (op0, 0)))
+ {
+ HOST_WIDE_INT bitsize, bitpos;
+ tree offset;
+ enum machine_mode mode;
+ int unsignedp, volatilep;
+ tree base = TREE_OPERAND (op0, 0);
+ base = get_inner_reference (base, &bitsize, &bitpos, &offset,
+ &mode, &unsignedp, &volatilep, false);
+ /* If the reference was to a (constant) zero offset, we can use
+ the address of the base if it has the same base type
+ as the result type. */
+ if (! offset && bitpos == 0
+ && TYPE_MAIN_VARIANT (TREE_TYPE (type))
+ == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
+ return fold_convert (type, build_fold_addr_expr (base));
+ }
+
if (TREE_CODE (op0) == MODIFY_EXPR
&& TREE_CONSTANT (TREE_OPERAND (op0, 1))
/* Detect assigning a bitfield. */