tree-vectorizer.h (_stmt_vec_info::reduc_fn): New.

2019-09-27  Richard Biener  <rguenther@suse.de>

	* tree-vectorizer.h (_stmt_vec_info::reduc_fn): New.
	(STMT_VINFO_REDUC_FN): Likewise.
	* tree-vectorizer.c (vec_info::new_stmt_vec_info): Initialize
	STMT_VINFO_REDUC_FN.
	* tree-vect-loop.c (vect_is_simple_reduction): Fix STMT_VINFO_REDUC_IDX
	for condition reductions.
	(vect_create_epilog_for_reduction): Compute all required state
	from the stmt to be vectorized.
	(vectorizable_reduction): Simplify vect_create_epilog_for_reduction
	invocation and remove then dead code.  For single def-use chains
	record only a single vector stmt.

From-SVN: r276180