re PR tree-optimization/71352 (ICE at -O1 and above on x86_64-linux-gnu: in zero_one_operation, at tree-ssa-reassoc.c:1251)

2016-05-31  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/71352
	* tree-ssa-reassoc.c (zero_one_operation): Handle op equal to
	minus one and a negate.

	* gcc.dg/tree-ssa/reassoc-45.c: New testcase.

From-SVN: r236920