[Bug tree-optimization/19049] not vectorizing a fortran loop

[Bug tree-optimization/19049] not vectorizing a fortran loop

[irar at il dot ibm dot com]

------- Comment #7 from irar at il dot ibm dot com  2006-09-19 07:29 -------
Even though vectorization of strided accesses is already implemented in the
autovect branch (and will be committed to the mainline 4.3), this case contains
a store with a gap (store to a[i] without a store to a[i-1]), and such stores
are not supported (the current implementation supports only loads with gaps).

Note, however, that adding a store to a[i-1] will create a data dependence in
the loop.

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049

[Bug tree-optimization/19049] not vectorizing a fortran loop

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Thu Oct 22 13:33:17 2015
New Revision: 229172

URL: https://gcc.gnu.org/viewcvs?rev=229172&root=gcc&view=rev
Log:
2015-10-22  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/19049
        PR tree-optimization/65962
        * tree-vect-data-refs.c (vect_analyze_group_access_1): Fall back
        to strided accesses if single-element interleaving doesn't work.

        * gcc.dg/vect/vect-strided-store-pr65962.c: New testcase.
        * gcc.dg/vect/vect-63.c: Adjust.
        * gcc.dg/vect/vect-70.c: Likewise.
        * gcc.dg/vect/vect-strided-u8-i2-gap.c: Likewise.
        * gcc.dg/vect/vect-strided-a-u8-i2-gap.c: Likewise.
        * gfortran.dg/vect/pr19049.f90: Likewise.
        * gfortran.dg/vect/vect-8.f90: Likewise.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/vect/vect-63.c
    trunk/gcc/testsuite/gcc.dg/vect/vect-70.c
    trunk/gcc/testsuite/gcc.dg/vect/vect-strided-a-u8-i2-gap.c
    trunk/gcc/testsuite/gcc.dg/vect/vect-strided-u8-i2-gap.c
    trunk/gcc/testsuite/gfortran.dg/vect/pr19049.f90
    trunk/gcc/testsuite/gfortran.dg/vect/vect-8.f90
    trunk/gcc/tree-vect-data-refs.c

[Bug tree-optimization/19049] not vectorizing a fortran loop

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
      Known to work|                            |6.0
         Resolution|---                         |FIXED

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.

[Bug tree-optimization/19049] not vectorizing a fortran loop

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049

--- Comment #10 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
We now get (at least on aarch64):
t.f90:11:0: note: === vect_pattern_recog ===
t.f90:11:0: note: === vect_analyze_data_ref_accesses ===
t.f90:11:0: note: Detected single element interleaving *a_23(D)[_22] step 8
t.f90:11:0: note: Data access with gaps requires scalar epilogue loop
t.f90:11:0: note: not consecutive access *a_23(D)[_25] = _28;

t.f90:11:0: note: not vectorized: complicated access pattern.
t.f90:11:0: note: bad data access.

[Bug tree-optimization/19049] not vectorizing a fortran loop

[irar at il dot ibm.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049

Ira Rosen <irar at il dot ibm.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |NEW
         AssignedTo|irar at il dot ibm.com      |unassigned at gcc dot
                   |                            |gnu.org

--- Comment #9 from Ira Rosen <irar at il dot ibm.com> 2010-11-10 06:59:44 UTC ---
This is still not implemented. And at the moment I am not planning to do that.

Ira

[Bug tree-optimization/19049] not vectorizing a fortran loop

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049

Thomas Koenig <tkoenig at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2007-07-09 07:42:10         |2010-11-09
                 CC|                            |tkoenig at gcc dot gnu.org
      Known to fail|                            |4.6.0

--- Comment #8 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2010-11-09 20:07:30 UTC ---
Still working on this?

$ gfortran -S -O3 -ftree-vectorizer-verbose=8 vect.f

vect.f:9: note: not vectorized: inner-loop count not invariant.
vect.f:10: note: Detected single element interleaving *a_107(D)[D.1623_106]
step 8
vect.f:10: note: Detected single element interleaving *b_111(D)[D.1620_110]
step 8
vect.f:10: note: not vectorized: complicated access pattern.
vect.f:1: note: vectorized 0 loops in function.

[Bug tree-optimization/19049] not vectorizing a fortran loop

[irar at il dot ibm dot com]

------- Additional Comments From irar at il dot ibm dot com  2005-07-26 07:07 -------
The data dependence issue was solved by this patch http://gcc.gnu.org/ml/gcc-
patches/2005-07/msg01195.html (committed). However, this loop is still not 
vectorizable because of noncontinuous access.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049

[Bug tree-optimization/19049] not vectorizing a fortran loop

[irar at il dot ibm dot com]

------- Additional Comments From irar at il dot ibm dot com  2005-04-25 09:58 -------
The vectorizer fails to determine dependence between: (*a_38)[D.719_49] and 
(*a_38)[D.718_51], since it fails to determine that both of the data-refs have 
the same base, *a_38. This is already fixed in autovect branch, and I am 
working on a patch to bring the changes in data-refs analysis to mainline.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |irar at il dot ibm dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2005-01-01 04:23:21         |2005-04-25 09:58:44
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049

[Bug tree-optimization/19049] not vectorizing a fortran loop

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-04-02 00:16 -------
pr19049.f:10: note: not vectorized: can't determine dependence between: (*a_38)[D.722_49] and 
(*a_38)[D.721_51]
pr19049.f:10: note: bad data dependence.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|not vectorizing fortran     |not vectorizing a fortran
                   |loops because not moving    |loop
                   |user lables on the tree     |
                   |level                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19049