Handle double reduction in parloops

Handle double reduction in parloops

2015-07-28  Tom de Vries  <tom@codesourcery.com>

	* tree-parloops.c (reduc_stmt_res): New function.
	(initialize_reductions, add_field_for_reduction)
	(create_phi_for_local_result, create_loads_for_reductions)
	(create_stores_for_reduction, build_new_reduction): Handle case that
	reduc_stmt is a phi.
	(gather_scalar_reductions): Allow double_reduc reductions.

	* gcc.dg/autopar/uns-outer-4.c: Remove xfail on scan for parallelizing
	outer loop.

	* testsuite/libgomp.c/uns-outer-4.c: New test.

From-SVN: r226300