re PR tree-optimization/61171 (vectorization fails for a reduction in presence of...

re PR tree-optimization/61171 (vectorization fails for a reduction in presence of subtraction)

2017-07-20  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/61171
	* tree-vectorizer.h (slp_instance): Add reduc_phis member.
	(vect_analyze_stmt): Add slp instance parameter.
	(vectorizable_reduction): Likewise.
	* tree-vect-loop.c (vect_analyze_loop_operations): Adjust.
	(vect_is_simple_reduction): Deal with chains not detected
	as SLP reduction chain, specifically not properly associated
	chains containing a mix of plus/minus.
	(get_reduction_op): Remove.
	(get_initial_defs_for_reduction): Simplify, pass in whether
	this is a reduction chain, pass in the SLP node for the PHIs.
	(vect_create_epilog_for_reduction): Get the SLP instance as
	arg and adjust.
	(vectorizable_reduction): Get the SLP instance as arg.
	During analysis remember the SLP node with the PHIs in the
	instance.  Simplify getting at the vectorized reduction PHIs.
	* tree-vect-slp.c (vect_slp_analyze_node_operations): Pass
	through SLP instance.
	(vect_slp_analyze_operations): Likewise.
	* tree-vect-stms.c (vect_analyze_stmt): Likewise.
	(vect_transform_stmt): Likewise.

	* g++.dg/vect/pr61171.cc: New testcase.
	* gfortran.dg/vect/pr61171.f: Likewise.
	* gcc.dg/vect/vect-reduc-11.c: Likewise.

From-SVN: r250382