[Bug tree-optimization/42108] [4.4/4.5 Regression] 50% performance regression

[rguenth at gcc dot gnu dot org]

------- Comment #42 from rguenth at gcc dot gnu dot org  2009-12-19 11:25 -------
Subject: Bug 42108

Author: rguenth
Date: Sat Dec 19 11:24:49 2009
New Revision: 155360

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155360
Log:
2009-12-19  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/42108
        * tree-ssa-sccvn.c (last_vuse_ptr): New variable.
        (vn_reference_lookup_2): Update last seen VUSE.
        (vn_reference_lookup_3): Avoid updating last seen VUSE after
        translating.
        (visit_reference_op_load): Use last seen VUSE from the first
        lookup when entering into the table.

        * gfortran.dg/pr42108.f90: New testcase.

Added:
    trunk/gcc/testsuite/gfortran.dg/pr42108.f90
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-sccvn.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42108