2018-10-26  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/87105
	* tree-vectorizer.h (_slp_tree::refcnt): New member.
	* tree-vect-slp.c (vect_free_slp_tree): Decrement and honor
	refcnt.
	(vect_create_new_slp_node): Initialize refcnt to one.
	(bst_traits): Move.
	(scalar_stmts_set_t, bst_fail): Remove.
	(vect_build_slp_tree_2): Add bst_map argument and adjust calls.
	(vect_build_slp_tree): Add bst_map argument and lookup
	already created SLP nodes.
	(vect_print_slp_tree): Handle a SLP graph, print SLP node
	addresses.
	(vect_slp_rearrange_stmts): Handle a SLP graph.
	(vect_analyze_slp_instance): Adjust and free SLP nodes from
	the CSE map.  Fix indenting.
	(vect_schedule_slp_instance): Add short-cut.

	* g++.dg/vect/slp-pr87105.cc: Adjust.
	* gcc.dg/torture/20181024-1.c: New testcase.
	* g++.dg/opt/20181025-1.C: Likewise.

From-SVN: r265522