re PR tree-optimization/18437 (vectorizer failed for matrix multiplication)

re PR tree-optimization/18437 (vectorizer failed for matrix multiplication)

	PR tree-optimization/18437

	* tree-vectorizer.h (_stmt_vec_info.stride_load_p): New member.
	(STMT_VINFO_STRIDE_LOAD_P): New accessor.
	(vect_check_strided_load): Declare.
	* tree-vect-data-refs.c (vect_check_strided_load): New function.
	(vect_analyze_data_refs): Use it to accept strided loads.
	* tree-vect-stmts.c (vectorizable_load): Ditto and handle them.

testsuite/
	* gfortran.dg/vect/rnflow-trs2a2.f90: New test.

From-SVN: r186530