re PR tree-optimization/92241 (ice in vect_mark_pattern_st mts, at tree-vect-patterns...

re PR tree-optimization/92241 (ice in vect_mark_pattern_st mts, at tree-vect-patterns.c:5175)

2019-10-28  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/92241
	* tree-vect-loop.c (vect_fixup_scalar_cycles_with_patterns): When
	we failed to update the reduction index do not use the pattern
	stmts for the reduction chain.
	(vectorizable_reduction): When the reduction chain is corrupt,
	fail.
	* tree-vect-patterns.c (vect_mark_pattern_stmts): Stop when we
	fail to update the reduction chain.

	* gcc.dg/torture/pr92241.c: New testcase.

From-SVN: r277516