2017-01-13  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/77283
	* gimple-ssa-split-paths.c: Include gimple-ssa.h, tree-phinodes.h
	and ssa-iterators.h.
	(is_feasible_trace): Implement a cost model based on joiner
	PHI node uses.

	* gcc.dg/tree-ssa/split-path-7.c: Adjust.
	* gcc.dg/tree-ssa/split-path-8.c: New testcase.
	* gcc.dg/tree-ssa/split-path-9.c: Likewise.

From-SVN: r244392