[Bug tree-optimization/48822] [4.5/4.6 Regression] G++ gets stucks and never finishes compilation when enabling -O2/3 optimization options.

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48822

--- Comment #8 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-12 14:08:05 UTC ---
Author: rguenth
Date: Thu May 12 14:08:00 2011
New Revision: 173705

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=173705
Log:
2011-05-12  Richard Guenther  <rguenther@suse.de>

        Backport from mainline
        2011-05-02  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/48822
    * tree-ssa-sccvn.c (set_ssa_val_to): Never go up the lattice.
    (process_scc): Indicate which iteration we start.

    * gcc.dg/torture/pr48822.c: New testcase.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/gcc.dg/torture/pr48822.c
Modified:
    branches/gcc-4_6-branch/gcc/ChangeLog
    branches/gcc-4_6-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_6-branch/gcc/tree-ssa-sccvn.c