PR rtl-optimization/68376
	PR rtl-optimization/68670
	* ifcvt.c (noce_try_abs): For one_cmpl allow < 0, >= 0
	or > -1 conditions regardless of negate, and disallow
	all other conditions.

	* gcc.c-torture/execute/pr68376-2.c (f5, f6, f7, f8): New
	tests.
	(main): Call them.
	* gcc.dg/pr68670-1.c: New test.
	* gcc.dg/pr68670-2.c: New test.

From-SVN: r231526