[Bug tree-optimization/48172] [4.5 Regression] incorrect vectorization of loop in GCC 4.5.* with -O3

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48172

--- Comment #18 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-03 13:08:02 UTC ---
Author: rguenth
Date: Tue Jan  3 13:07:57 2012
New Revision: 182841

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=182841
Log:
2011-05-18  Richard Guenther  <rguenther@suse.de>

    Backport from mainline
    2011-05-12  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/48172
    * tree-vect-loop-manip.c (vect_vfa_segment_size): Do not exclude
    the number of iterations from the segment size calculation.
    (vect_create_cond_for_alias_checks): Adjust.

    2011-05-13  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/48172
    * tree-vect-loop-manip.c (vect_vfa_segment_size): Avoid
    multiplying by number of iterations for equal step.
    (vect_create_cond_for_alias_checks): Likewise.

    * gcc.dg/vect/pr48172.c: New testcase.

Added:
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/vect/pr48172.c
Modified:
    branches/gcc-4_5-branch/gcc/ChangeLog
    branches/gcc-4_5-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_5-branch/gcc/tree-vect-loop-manip.c