Suitable regression test for vectorizer patches?

[Joern Wolfgang Rennecke]

I want to submit some vectorizer patches, what would be a suitable 
regression test?
Preferably some native or cross test that can run on an i7 x86_64 
GNU/Linux machine.

To give an idea what code I'm patching, here are the patches I got so far:

         * tree-vect-patterns.c (vect_recog_dot_prod_pattern): Recognize 
unsigned dot product pattern.

Allow widening multiply-add to be used for DOT_PROF_EXPR reductions.
         * tree-vect-data-refs.c (vect_get_smallest_scalar_type):
         Treat WIDEN_MULT_PLUS_EXPR like WIDEN_SUM_EXPR.
         * tree-vect-loop.c (get_initial_def_for_reduction): Likewise.
         Get VECTYPE from STMT_VINFO_VECTYPE.
         (vect_determine_vectorization_factor):
         Allow vcector size input/output mismatch for reduction.
         (vect_analyze_scalar_cycles_1): When we find a phi for a reduction,
         put the reduction statement into the phi's STMT_VINFO_RELATED_STMT.
         * tree-vect-patterns.c (vect_pattern_recog_1): If DOT_PROD_EXPR 
can't
         be expanded directly, try to use WIDEN_MULT_PLUS_EXPR instead.

Fix bug where a vectorizer reduction split (from 
TARGET_VECTORIZE_SPLIT_REDUCTION)
would end up not being used.
         * tree-vect-loop.c (vect_create_epilog_for_reduction):
         If we split the reduction, use the result in Case 3 too.