2019-07-31  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91293
	* tree-vect-slp.c (vect_build_slp_tree_2): Do not swap operands
	of reduction stmts.

	* gcc.dg/vect/pr91293-1.c: New testcase.
	* gcc.dg/vect/pr91293-2.c: Likewise.
	* gcc.dg/vect/pr91293-3.c: Likewise.

From-SVN: r273934