[Bug tree-optimization/46590] [4.6/4.7/4.8 Regression] long compile time with -O2 and many loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46590

--- Comment #28 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-08-22 13:17:42 UTC ---
Author: rguenth
Date: Wed Aug 22 13:17:26 2012
New Revision: 190594

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=190594
Log:
2012-08-22  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/46590
    * tree-ssa-alias.h (get_continuation_for_phi): Add alias query
    counter output argument.
    (walk_non_aliased_vuses): Add alias query counter argument
    to the walker callback.
    * tree-ssa-alias.c (maybe_skip_until): Add alias query counter
    output argument and count alias queries.
    (get_continuation_for_phi_1): Likewise.
    (get_continuation_for_phi): Likewise.
    (walk_non_aliased_vuses): Add alias query counter argument
    to the walker callback and allow it to abort the walk by
    returning -1.
    * tree-ssa-pre.c (translate_vuse_through_block): Adjust.
    * tree-ssa-sccvn.c (vn_reference_lookup_2): Add alias query
    counter parmeter, abort walk if that is bigger than
    --param sccvn-max-alias-queries-per-access.
    * params.def (sccvn-max-alias-queries-per-access): New param.
    * doc/invoke.texi (sccvn-max-alias-queries-per-access): Document.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/doc/invoke.texi
    trunk/gcc/params.def
    trunk/gcc/tree-ssa-alias.c
    trunk/gcc/tree-ssa-alias.h
    trunk/gcc/tree-ssa-pre.c
    trunk/gcc/tree-ssa-sccvn.c