2007-11-23  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-copy.c (may_propagate_copy): Remove redundant
	checks.
	(merge_alias_info): Do verification only if checking is
	enabled.  Merge flow-sensitive alias information in simple
	cases.
	* tree-ssa-operands.c (get_addr_dereference_operands): Also
	complain about missing NMTs.

	* gcc.dg/tree-ssa/alias-17.c: New testcase.

From-SVN: r130370