Don't cancel loop tree in parloops

Don't cancel loop tree in parloops

2015-07-31  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/66846
	* omp-low.c (expand_omp_taskreg) [ENABLE_CHECKING]: Call
	verify_loop_structure for child_cfun if !LOOPS_NEED_FIXUP.
	(expand_omp_target) [ENABLE_CHECKING]: Same.
	(execute_expand_omp) [ENABLE_CHECKING]: Call verify_loop_structure for
	cfun if !LOOPS_NEED_FIXUP.
	(expand_omp_for_static_nochunk): Handle simple latch bb.  Handle case
	that omp_for already has its own loop struct.
	* tree-parloops.c (create_phi_for_local_result)
	(create_call_for_reduction): Handle simple latch bb.
	(create_parallel_loop): Add simple latch bb to preserve
	LOOPS_HAVE_SIMPLE_LATCHES.  Record new exit.  Handle simple latch bb.
	(gen_parallel_loop): Remove call to cancel_loop_tree.
	(parallelize_loops): Skip loops that are inner loops of parallelized
	loops.
	(pass_parallelize_loops::execute) [ENABLE_CHECKING]: Call
	verify_loop_structure.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@226427 138bc75d-0d04-0410-961f-82ee72b054a4