re PR middle-end/68852 (ICE in vect_is_simple_use (tree-vect-stmts.c:8750) using -O3)

2015-12-14  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68852
	* tree-vectorizer.h (struct _slp_tree): Add def_type member.
	(SLP_TREE_DEF_TYPE): New accessor.
	* tree-vect-stmts.c (vect_is_simple_use): Remove BB vectorization
	hack.
	* tree-vect-slp.c (vect_create_new_slp_node): Initialize
	SLP_TREE_DEF_TYPE.
	(vect_build_slp_tree): When a node is to be built up from scalars
	do not push a NULL as child but instead set its def_type to
	vect_external_def.
	(vect_analyze_slp_cost_1): Check for child def-type instead
	of NULL.
	(vect_detect_hybrid_slp_stmts): Likewise.
	(vect_bb_slp_scalar_cost): Likewise.
	(vect_get_slp_defs): Likewise.
	(vect_slp_analyze_node_operations): Likewise.  Before
	processing node push the children def-types to the underlying
	stmts vinfo and restore it afterwards.
	(vect_schedule_slp_instance): Likewise.
	(vect_slp_analyze_bb_1): Do not mark stmts not in SLP instances
	as not vectorizable.

	* g++.dg/torture/pr68852.C: New testcase.

From-SVN: r231619