[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]

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

--- Comment #4 from irar at gcc dot gnu.org 2011-05-26 07:50:14 UTC ---
Author: irar
Date: Thu May 26 07:50:09 2011
New Revision: 174265

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=174265
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_get_known_peeling_cost): 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:
    trunk/gcc/testsuite/gcc.dg/vect/pr49038.c
    trunk/gcc/testsuite/gcc.dg/vect/vect-strided-u8-i8-gap4-unknown.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-data-refs.c
    trunk/gcc/tree-vect-loop-manip.c
    trunk/gcc/tree-vect-loop.c
    trunk/gcc/tree-vectorizer.h