[Bug c/33426] New: Support of #pragma ivdep

[Bug c/33426] New: Support of #pragma ivdep

[gjunk at sapience dot com]

When comparing run time on some (floating point) CPU intensive code, we find
that Intel's ICC (9.1) compiler runs significantly faster (30 - 50%) for some
programs - this seems to stem (large) part from ICC's ability to take advantage
of #pragma ivdep. There may be some other differences of course. Tests were run
using gcc 3.3.3 - re-compiling relevant key code with gcc 4.1.2 did not make
any real change. 

Wondering if there are any plans to support this ?

thanks

gene/


-- 
           Summary: Support of #pragma ivdep
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gjunk at sapience dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug c/33426] Support of #pragma ivdep

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2007-09-13 21:12 -------
Confirmed.  Zdenek, we should now be able to attach this to loop information
and preserve it until data dependence analysis, right?


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu dot
                   |                            |org, rakdver at gcc dot gnu
                   |                            |dot org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-09-13 21:12:49
               date|                            |
            Summary|Support of #pragma ivdep    |Support of #pragma ivdep


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug c/33426] Support of #pragma ivdep

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2007-09-13 21:14 -------
What are the exact semantics of ivdep?
Please provide them before asking if we support it.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug c/33426] Support of #pragma ivdep

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2007-09-13 21:21 -------
#pragma ivdep

Says the compiler may assume the following loop nest does not have loop carried
data dependenices.

Supported at least by SGI CC and the Intel compiler.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
   Last reconfirmed|2007-09-13 21:12:49         |2007-09-13 21:21:05
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug c/33426] Support of #pragma ivdep

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2007-09-13 21:23 -------
http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi/0650/bks/SGI_Developer/books/Pragmas/sgi_html/ch08.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug c/33426] Support of #pragma ivdep

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2007-09-13 21:25 -------
The SGI compiler restricts the pragma to innermost loops.  The Intel compiler
restricts the pragma to affect assumed data-dependencies only, that is, if
data dependence analysis statically can prove a data-dependency this
dependency is _not_ ignored.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|other                       |c


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug c/33426] Support of #pragma ivdep

[rguenth at gcc dot gnu dot org]

------- Comment #6 from rguenth at gcc dot gnu dot org  2007-09-13 21:26 -------
http://www.intel.com/cd/ids/developer/asmo-na/eng/65774.htm?page=4


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug other/33426] Support of #pragma ivdep

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2007-09-13 21:27 -------
http://gcc.gnu.org/ml/gcc-patches/2005-03/msg00166.html


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |other


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug other/33426] Support of #pragma ivdep

[gjunk at sapience dot com]

------- Comment #8 from gjunk at sapience dot com  2007-09-13 22:21 -------
*** Bug 33427 has been marked as a duplicate of this bug. ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug other/33426] Support of #pragma ivdep

[gjunk at sapience dot com]

------- Comment #9 from gjunk at sapience dot com  2007-09-19 21:34 -------
Thanks for feedback - not exactly sure where this leaves things - but if gcc
can deliver the same kind of floating point performance as icc it would be a
really good thing.

The 2005 article - wasn't clear to me what that meant other than this was
considered some time back - I assume this is a 2 step process.

   (1) making the info available (perhaps that is already done - is that what
that means?)

   (2) consuming the info so the optimization engine can do a better job -
which I suspect is work still remaining.

Thank you for all your help.

g/


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

[Bug other/33426] Support of #pragma ivdep

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

--- Comment #18 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Author: burnus
Date: Wed Oct 30 18:53:42 2013
New Revision: 204223

URL: http://gcc.gnu.org/viewcvs?rev=204223&root=gcc&view=rev
Log:
2013-10-30  Tobias Burnus  <burnus@net-b.de>

gcc/cp/
        PR other/33426
        * cp-tree.h (RANGE_FOR_IVDEP): Define.
        (cp_convert_range_for, finish_while_stmt_cond, finish_do_stmt,
        finish_for_cond): Take 'bool ivdep' parameter.
        * cp-array-notation.c (create_an_loop): Update call.
        * init.c (build_vec_init): Ditto.
        * pt.c (tsubst_expr): Ditto.
        * parser.c (cp_parser_iteration_statement, cp_parser_for,
        cp_parser_range_for, cp_convert_range_for): Update calls.
        (cp_parser_pragma): Accept GCC ivdep for 'while' and 'do'.
        * semantics.c (finish_while_stmt_cond, finish_do_stmt,
        finish_for_cond): Optionally build ivdep annotation.

gcc/testsuite/
        PR other/33426
        * g++.dg/vect/pr33426-ivdep-2.cc: New.
        * g++.dg/vect/pr33426-ivdep-3.cc: New.
        * g++.dg/vect/pr33426-ivdep-4.cc: New.

gcc/
        PR other/33426
        * gcc/tree-cfg.c (replace_loop_annotate): Replace warning by
        warning_at.


Added:
    trunk/gcc/testsuite/g++.dg/vect/pr33426-ivdep-2.cc
    trunk/gcc/testsuite/g++.dg/vect/pr33426-ivdep-3.cc
    trunk/gcc/testsuite/g++.dg/vect/pr33426-ivdep-4.cc
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-array-notation.c
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/init.c
    trunk/gcc/cp/parser.c
    trunk/gcc/cp/pt.c
    trunk/gcc/cp/semantics.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-cfg.c

[Bug other/33426] Support of #pragma ivdep

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

--- Comment #17 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Author: burnus
Date: Sun Oct 27 07:40:31 2013
New Revision: 204102

URL: http://gcc.gnu.org/viewcvs?rev=204102&root=gcc&view=rev
Log:
2013-10-27  Tobias Burnus  <burnus@net-b.de>

gcc/c/
        PR other/33426
        * c-parser.c (c_parser_while_statement,
        * c_parser_while_statement,
        c_parser_pragma): Add GCC ivdep support to 'do' and 'while'.
        (c_parser_statement_after_labels): Update calls.

gcc/testsuite/
        PR other/33426
        * gcc.dg/vect/vect-ivdep-2.c: New.


Added:
    trunk/gcc/testsuite/gcc.dg/vect/vect-ivdep-2.c
Modified:
    trunk/gcc/c/ChangeLog
    trunk/gcc/c/c-parser.c
    trunk/gcc/testsuite/ChangeLog

[Bug other/33426] Support of #pragma ivdep

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #16 from Tobias Burnus <burnus at gcc dot gnu.org> ---
FIXED on the trunk (4.9).

[Bug other/33426] Support of #pragma ivdep

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

--- Comment #15 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Author: burnus
Date: Fri Oct 25 05:47:25 2013
New Revision: 204047

URL: http://gcc.gnu.org/viewcvs?rev=204047&root=gcc&view=rev
Log:
2013-10-25  Tobias Burnus  <burnus@net-b.de>

        PR other/33426
        * parser.c (cp_parser_iteration_statement,
        cp_parser_for, cp_parser_c_for, cp_parser_pragma): Handle
        IVDEP pragma.

        * g++.dg/parse/ivdep.C: New.
        * g++.dg/vect/pr33426-ivdep.cc: New.


Added:
    trunk/gcc/testsuite/g++.dg/parse/ivdep.C
    trunk/gcc/testsuite/g++.dg/vect/pr33426-ivdep.cc
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/parser.c
    trunk/gcc/testsuite/ChangeLog

[Bug other/33426] Support of #pragma ivdep

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org

--- Comment #14 from Tobias Burnus <burnus at gcc dot gnu.org> ---
With the comment of comment 13, C now supports:
  #pragma GCC ivdep
as described at http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html (link at the
bottom, [when the doc is updated in a couple of hours]).

Note: The C++ patch is still pending review; for Fortran, see also PR44646
comment 5.

[Bug other/33426] Support of #pragma ivdep

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

--- Comment #13 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Author: burnus
Date: Thu Oct 24 16:25:44 2013
New Revision: 204021

URL: http://gcc.gnu.org/viewcvs?rev=204021&root=gcc&view=rev
Log:
2013-08-24  Tobias Burnus  <burnus@net-b.de>

        PR other/33426
        * c-pragma.c (init_pragma) Add #pragma ivdep handling.
        * c-pragma.h (pragma_kind): Add PRAGMA_IVDEP.

        PR other/33426
        * c-parser.c (c_parser_pragma, c_parser_for_statement):
        Handle PRAGMA_IVDEP.
        (c_parser_statement_after_labels): Update call.

        PR other/33426
        * tree-cfg.c (replace_loop_annotate): New function.
        (execute_build_cfg): Call it.
        * gimplify.c (gimple_boolify, gimplify_expr): Handle
        * ANNOTATE_EXPR.
        * internal-fn.c (expand_ANNOTATE): New function.
        * internal-fn.def (ANNOTATE): Define as new internal function.
        * tree-core.h (tree_node_kind): Add annot_expr_ivdep_kind.
        * tree-pretty-print.c (dump_generic_node): Handle ANNOTATE_EXPR.
        * tree.def (ANNOTATE_EXPR): New DEFTREECODE.
        * doc/extend.texi (Pragmas): Document #pragma ivdep.
        * doc/generic.texi (Expressions): Document ANNOTATE_EXPR.

        PR other/33426
        * testsuite/gcc.dg/ivdep.c: New.
        * testsuite/gcc.dg/vect/vect-ivdep-1.c: New.


Added:
    trunk/gcc/testsuite/gcc.dg/ivdep.c
    trunk/gcc/testsuite/gcc.dg/vect/vect-ivdep-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c-pragma.c
    trunk/gcc/c-family/c-pragma.h
    trunk/gcc/c/ChangeLog
    trunk/gcc/c/c-parser.c
    trunk/gcc/doc/extend.texi
    trunk/gcc/doc/generic.texi
    trunk/gcc/gimplify.c
    trunk/gcc/internal-fn.c
    trunk/gcc/internal-fn.def
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-cfg.c
    trunk/gcc/tree-core.h
    trunk/gcc/tree-pretty-print.c
    trunk/gcc/tree.def

[Bug other/33426] Support of #pragma ivdep

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

vincenzo Innocente <vincenzo.innocente at cern dot ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vincenzo.innocente at cern
                   |                            |dot ch

--- Comment #12 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2011-07-17 05:39:12 UTC ---
any news on this?
I reached 
" disable versioning for alias - max number of generated checks exceeded."
because of PR49761 and really need to tell GCC to vectorize ignoring possibly
dependencies

[Bug other/33426] Support of #pragma ivdep

[gjunk at sapience dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

--- Comment #11 from gene <gjunk at sapience dot com> 2011-05-07 12:15:22 UTC ---
Any update on this ?

[Bug other/33426] Support of #pragma ivdep

[gjunk at sapience dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33426

--- Comment #10 from gene <gjunk at sapience dot com> 2010-11-02 20:16:32 UTC ---
I wonder if this thread is germaine or useful to this enhancement request ?

http://gcc.gnu.org/ml/gcc/2009-10/msg00352.html

 g/