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

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

2019-10-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/65930
	* tree-vect-loop.c (check_reduction_path): Relax single-use
	check allowing out-of-loop uses.
	(vect_is_simple_reduction): SLP reduction chains cannot have
	intermediate stmts used outside of the loop.
	(vect_create_epilog_for_reduction): The adjustment might need
	to be converted.
	(vectorizable_reduction): Annotate live stmts of the reduction
	chain with STMT_VINFO_REDUC_DEF.
	* tree-vect-stms.c (process_use): Remove no longer true asserts.

	* gcc.dg/vect/pr65930-1.c: New testcase.

From-SVN: r277566