re PR tree-optimization/60276 (-O3 autovectorizer breaks on a particular loop)

re PR tree-optimization/60276 (-O3 autovectorizer breaks on a particular loop)

2014-02-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/60276
	* tree-vectorizer.h (struct _stmt_vec_info): Add min_neg_dist field.
	(STMT_VINFO_MIN_NEG_DIST): New macro.
	* tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Record
	STMT_VINFO_MIN_NEG_DIST.
	* tree-vect-stmts.c (vectorizable_load): Verify if assumptions
	made for negative dependence distances still hold.

	* gcc.dg/vect/pr60276.c: New testcase.

From-SVN: r207992