Support non-masked epilogue vectoriziation

gcc/

2016-11-16  Yuri Rumyantsev  <ysrumyan@gmail.com>

	* params.def (PARAM_VECT_EPILOGUES_NOMASK): New.
	* tree-if-conv.c (tree_if_conversion): Make public.
	* * tree-if-conv.h: New file.
	* tree-vect-data-refs.c (vect_analyze_data_ref_dependences) Avoid
	dynamic alias checks for epilogues.
	* tree-vect-loop-manip.c (vect_do_peeling): Return created epilog.
	* tree-vect-loop.c: include tree-if-conv.h.
	(new_loop_vec_info): Add zeroing orig_loop_info field.
	(vect_analyze_loop_2): Don't try to enhance alignment for epilogues.
	(vect_analyze_loop): Add argument ORIG_LOOP_INFO which is not NULL
	if epilogue is vectorized, set up orig_loop_info field of loop_vinfo
	using passed argument.
	(vect_transform_loop): Check if created epilogue should be returned
	for further vectorization with less vf.  If-convert epilogue if
	required. Print vectorization success for epilogue.
	* tree-vectorizer.c (vectorize_loops): Add epilogue vectorization
	if it is required, pass loop_vinfo produced during vectorization of
	loop body to vect_analyze_loop.
	* tree-vectorizer.h (struct _loop_vec_info): Add new field
	orig_loop_info.
	(LOOP_VINFO_ORIG_LOOP_INFO): New.
	(LOOP_VINFO_EPILOGUE_P): New.
	(LOOP_VINFO_ORIG_VECT_FACTOR): New.
	(vect_do_peeling): Change prototype to return epilogue.
	(vect_analyze_loop): Add argument of loop_vec_info type.
	(vect_transform_loop): Return created loop.

gcc/testsuite/

2016-11-16  Yuri Rumyantsev  <ysrumyan@gmail.com>

	* lib/target-supports.exp (check_avx2_hw_available): New.
	(check_effective_target_avx2_runtime): New.
	* gcc.dg/vect/vect-tail-nomask-1.c: New test.

From-SVN: r242501