[Bug tree-optimization/82604] [8 Regression] SPEC CPU2006 410.bwaves ~50% performance regression with trunk@253679 when ftree-parallelize-loops is used

[amker at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82604

--- Comment #18 from amker at gcc dot gnu.org ---
Author: amker
Date: Tue Jan 23 16:47:03 2018
New Revision: 256990

URL: https://gcc.gnu.org/viewcvs?rev=256990&root=gcc&view=rev
Log:
        PR tree-optimization/82604
        * tree-loop-distribution.c (enum partition_kind): New enum item
        PKIND_PARTIAL_MEMSET.
        (partition_builtin_p): Support above new enum item.
        (generate_code_for_partition): Ditto.
        (compute_access_range): Differentiate cases that equality can be
        proven at all loops, the innermost loops or no loops.
        (classify_builtin_st, classify_builtin_ldst): Adjust call to above
        function.  Set PKIND_PARTIAL_MEMSET for partition appropriately.
        (finalize_partitions, distribute_loop): Don't fuse partition of
        PKIND_PARTIAL_MEMSET kind when distributing 3-level loop nest.
        (prepare_perfect_loop_nest): Distribute 3-level loop nest only if
        parloop is enabled.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-loop-distribution.c