tree-ssa-ccp.c (likely_value): See if we have operands that are marked as never simulate again and return...

2015-04-16  Richard Biener  <rguenther@suse.de>

	* tree-ssa-ccp.c (likely_value): See if we have operands that
	are marked as never simulate again and return CONSTANT in this
	case.
	* tree-ssa-propagate.c (simulate_stmt): Mark stmts that do
	not have any operands that will be simulated again as
	not being simulated again.

	* gcc.dg/tree-ssa/ssa-ccp-36.c: New testcase.
	* gcc.dg/tree-ssa/pr37508.c: Adjust.
	* gfortran.dg/reassoc_6.f: Remove XFAIL.

From-SVN: r222141