2014-04-14  Richard Biener  <rguenther@suse.de>

	* tree-ssa-forwprop.c (simplify_gimple_switch): Enhance
	check for which sign-changes we allow when forwarding
	a converted value into a switch.

	* g++.dg/tree-ssa/forwprop-switch.C: New testcase.

From-SVN: r209372