re PR tree-optimization/79666 (wrong code (SIGFPE) at -O2 on x86_64-linux-gnu (in both 32-bit and 64-bit modes))

2017-02-22  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/79666
	* tree-vrp.c (extract_range_from_binary_expr_1): Make sure
	to not symbolically negate if that may introduce undefined
	overflow.

	* gcc.dg/torture/pr79666.c: New testcase.

From-SVN: r245648