[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720

--- Comment #12 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-10-22 
14:44:53 UTC ---
Author: rguenth
Date: Fri Oct 22 14:44:48 2010
New Revision: 165832

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=165832
Log:
2010-10-22  Richard Guenther  <rguent...@suse.de>

    PR tree-optimization/45720
    * tree-vect-data-refs.c (vect_update_misalignment_for_peel):
    Handle negative step.
    (vect_enhance_data_refs_alignment): Likewise.
    * tree-vect-loop-manip.c (vect_gen_niters_for_prolog_loop): Likewise.
    (vect_create_cond_for_align_checks): Likewise.
    (vect_create_cond_for_alias_checks): Likewise.

    * gcc.dg/torture/pr45720.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr45720.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-data-refs.c
    trunk/gcc/tree-vect-loop-manip.c