re PR tree-optimization/83202 (Try joining operations on consecutive array elements during tree vectorization)

2017-11-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/83202
	* tree-vect-slp.c (scalar_stmts_set_t): New typedef.
	(bst_fail): Use it.
	(vect_analyze_slp_cost_1): Add visited set, do not account SLP
	nodes vectorized to the same stmts multiple times.
	(vect_analyze_slp_cost): Allocate a visited set and pass it down.
	(vect_analyze_slp_instance): Adjust.
	(scalar_stmts_to_slp_tree_map_t): New typedef.
	(vect_schedule_slp_instance): Add a map recording the SLP node
	representing the vectorized stmts for a set of scalar stmts.
	Avoid code-generating redundancies.
	(vect_schedule_slp): Allocate map and pass it down.

	* gcc.dg/vect/costmodel/x86_64/costmodel-pr83202.c: New testcase.

From-SVN: r255233