2009-06-08 Ghassan Shobaki <ghassan.shobaki@amd.com>

2009-06-08  Ghassan Shobaki  <ghassan.shobaki@amd.com>
            Dwarakanath Rajagopal  <dwarak.rajagopal@amd.com>

        * tree-ssa-loop-prefetch.c
        (gather_memory_references): Introduced a counter for the number of
        memory references.
        (anything_to_prefetch_p): Introduced a counter for the number of
        prefetches.
        (is_loop_prefetching_profitable): New function with a cost model
        for prefetching.
        (loop_prefetch_arrays): Use the new cost model to determine if
        prefetching is profitable.
        * params.def (MIN_INSN_TO_PREFETCH_RATIO,
        PREFETCH_MIN_INSN_TO_MEM_RATIO): New parameters.
        * params.h (MIN_INSN_TO_PREFETCH_RATIO,
        PREFETCH_MIN_INSN_TO_MEM_RATIO): New parameters.
        * doc/invoke.texi (MIN_INSN_TO_PREFETCH_RATIO,
        PREFETCH_MIN_INSN_TO_MEM_RATIO): New parameters.

Co-Authored-By: Dwarakanath Rajagopal <dwarak.rajagopal@amd.com>
From-SVN: r148277