2011-05-10 Richard Guenther <rguenther@suse.de>

2011-05-10  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-forwprop.c (combine_conversions): Pattern-match
	a series of conversions and apply foldings similar to what
	fold-const does.
	(tree_ssa_forward_propagate_single_use_vars): Call it.

	* gcc.dg/tree-ssa/ssa-fre-2.c: Disable forwprop.
	* gcc.dg/tree-ssa/ssa-fre-3.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-4.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-5.c: Likewise.
	* gcc.dg/tree-ssa/scev-cast.c: Adjust.  Note what transformation
	applies.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@173612 138bc75d-0d04-0410-961f-82ee72b054a4