2009-04-11  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/39713
	* tree-ssa-sccvn.c (vn_get_expr_for): Make sure built
	reference trees have SSA_NAME operands.

	* g++.dg/torture/pr39713.C: New testcase.

From-SVN: r145951