[Bug tree-optimization/39141] overzealous unrolling (peeling) destroys code locality

["amylaar at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #3 from amylaar at gcc dot gnu dot org  2010-01-27 20:04 -------
Subject: Bug 39141

Author: amylaar
Date: Wed Jan 27 20:03:57 2010
New Revision: 156301

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=156301
Log:
        PR tree-optimization/39141
        * tree-ssa-loop-manip.c (gimple_can_duplicate_loop_to_header_edge):
        New function.
        * tree-ssa-loop-ivcanon.c (enum unroll_level): New value
        UL_ESTIMATE_GROWTH.
        (try_unroll_loop_completely): Handle UL_ESTIMATE_GROWTH.
        (canonicalize_loop_induction_variables): Likewise.
        (tree_unroll_loops_completely): Don't completely unroll loops where
        the outer loop/function is larger than
        PARAM_MAX_COMPLETELY_PEELED_OUTER_INSNS, or will/would become thus
        due to unrolling.
        * cfgloop.h (enum li_flags): New value LI_REALLY_FROM_INNERMOST.
        (fel_init): Handle LI_REALLY_FROM_INNERMOST.
        * tree-flow.h (gimple_can_duplicate_loop_to_header_edge): Declare.
        * params.def (PARAM_MAX_COMPLETELY_PEELED_OUTER_INSNS): New parameter.

Added:
    branches/mpost-opt-imp-20100127/gcc/ChangeLog.mpost
Modified:
    branches/mpost-opt-imp-20100127/gcc/cfgloop.h
    branches/mpost-opt-imp-20100127/gcc/params.def
    branches/mpost-opt-imp-20100127/gcc/tree-flow.h
    branches/mpost-opt-imp-20100127/gcc/tree-ssa-loop-ivcanon.c
    branches/mpost-opt-imp-20100127/gcc/tree-ssa-loop-manip.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39141