re PR tree-optimization/65930 (Reduction with sign-change not handled)

re PR tree-optimization/65930 (Reduction with sign-change not handled)

2019-10-23  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/65930
	* tree-vect-loop.c (check_reduction_path): Allow conversions
	that only change the sign.
	(vectorizable_reduction): Relax latch def stmts we handle further.

	* gcc.dg/vect/vect-reduc-2char-big-array.c: Adjust.
	* gcc.dg/vect/vect-reduc-2char.c: Likewise.
	* gcc.dg/vect/vect-reduc-2short.c: Likewise.
	* gcc.dg/vect/vect-reduc-dot-s8b.c: Likewise.
	* gcc.dg/vect/vect-reduc-pattern-2c.c: Likewise.

From-SVN: r277322