tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Only add RW dependence for dependence distance zero.

2010-04-13  Richard Guenther  <rguenther@suse.de>

	* tree-vect-data-refs.c (vect_analyze_data_ref_dependence):
	Only add RW dependence for dependence distance zero.
	Adjust maximal vectorization factor according to dependences.
	Move alignment handling ...
	(vect_find_same_alignment_drs): ... here.  New function.
	(vect_analyze_data_ref_dependences): Adjust.
	(vect_analyze_data_refs_alignment): Call vect_find_same_alignment_drs.
	(vect_analyze_data_refs): Adjust minimal vectorization factor
	according to data references.
	* tree-vect-loop.c (vect_analyze_loop): Analyze data-ref
	dependences before determining the vectorization factor.
	Analyze alignment after determining the vectorization factor.
	* tree-vect-slp.c ((vect_slp_analyze_bb): Analyze data-ref
	dependences before alignment.
	* tree-vectorizer.h (vect_analyze_data_ref_dependences):
	Adjust prototype.
	(vect_analyze_data_refs): Likewise.
	(MAX_VECTORIZATION_FACTOR): New define.

	* gcc.dg/vect/no-vfa-vect-depend-1.c: Adjust.

From-SVN: r158259