2011-07-21 Richard Guenther <rguenther@suse.de>

2011-07-21  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/49770
	* tree-ssa-sccvn.c (valueize_refs_1): Return whether we
	valueized any operand.  Renamed from ...
	(valueize_refs): ... this.  New wrapper around valueize_refs_1.
	(valueize_shared_reference_ops_from_ref): Return whether we
	valueized any operand.
	(vn_reference_lookup): Only when we valueized any operand
	use the valueized reference for alias analysis.  Do not preserve
	the original reference tree in this case.

	* g++.dg/torture/pr49770.C: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@176567 138bc75d-0d04-0410-961f-82ee72b054a4