2011-05-11  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/15256
	* tree-ssa-forwprop.c (simplify_bitwise_binary): Canonicalize
	(A & B) | C, combine (A op CST1) op CST2.
	(tree_ssa_forward_propagate_single_use_vars): Only bother to
	visit assigns that have uses.

	* gcc.dg/tree-ssa/forwprop-14.c: New testcase.

From-SVN: r173659