re PR tree-optimization/68060 (ICE on valid code at -O3 on x86_64-linux-gnu in vect_g...

re PR tree-optimization/68060 (ICE on valid code at -O3 on x86_64-linux-gnu in vect_get_vec_def_for_operand, at tree-vect-stmts.c:1413)

2016-01-14  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68060
	* tree-vect-loop.c (vect_is_simple_reduction): Check the
	outer loop reduction is only used in the inner loop before
	detecting a double reduction.

	* gcc.dg/torture/pr68060-1.c: New testcase.
	* gcc.dg/torture/pr68060-2.c: Likewise.

From-SVN: r232367