2008-11-02  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/37542
	* tree-ssa-pre.c (fully_constant_expression): Handle more cases.
	* tree-ssa-sccvn.c (vn_get_expr_for): Fix typo.
	(vn_nary_op_lookup_stmt): Adjust for unary reference trees.
	(vn_nary_op_insert_stmt): Likewise.
	(visit_use): Likewise.

	* gcc.dg/tree-ssa/ssa-pre-22.c: New testcase.
	* gcc.c-torture/compile/20081101-1.c: Likewise.

From-SVN: r141534