re PR tree-optimization/91145 (ICE: in vect_build_slp_tree_2, at tree-vect-slp.c:1143 with -march=skylake-avx512 -O3)

2019-07-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91145
	* tree-vect-slp.c (vect_build_slp_tree_2): Fix reduction
	chain check.

	* gcc.dg/torture/pr91145.c: New testcase.

From-SVN: r273445