[Bug tree-optimization/49038] [4.5/4.6/4.7 Regression] -ftree-vectorise introduces reads past end of array

["irar at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49038

--- Comment #5 from irar at gcc dot gnu.org 2011-06-04 09:12:58 UTC ---
Author: irar
Date: Sat Jun  4 09:12:55 2011
New Revision: 174634

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=174634
Log:

    PR tree-optimization/49038
    * tree-vect-loop-manip.c (vect_generate_tmps_on_preheader):
    Ensure at least one epilogue iteration if required by data
    accesses with gaps.
    * tree-vectorizer.h (struct _loop_vec_info): Add new field
    to mark loops that require peeling for gaps.
    * tree-vect-loop.c (new_loop_vec_info): Initialize new field.
    (vect_estimate_min_profitable_iters): Take peeling for gaps into
    account.
    (vect_transform_loop): Generate epilogue if required by data
    access with gaps.
    * tree-vect-data-refs.c (vect_analyze_group_access): Mark the
    loop as requiring an epilogue if there are gaps in the end of
    the strided group.


Added:
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/vect/pr49038.c
   
branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/vect/vect-strided-u8-i8-gap4-unknown.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-data-refs.c
    branches/gcc-4_5-branch/gcc/tree-vect-loop-manip.c
    branches/gcc-4_5-branch/gcc/tree-vect-loop.c
    branches/gcc-4_5-branch/gcc/tree-vectorizer.h