[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/33427] 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=33427

[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 c/33427] Support of #pragma ivdep

[gjunk at sapience dot com]

--- Comment #1 from gjunk at sapience dot com  2007-09-13 22:21 ---
Oops - clicked refresh by mistake- feel free to delete this - sorry.


*** This bug has been marked as a duplicate of 33426 ***


-- 

gjunk at sapience dot com changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution||DUPLICATE
Summary|Support of #pragma ivdep|Support of #pragma ivdep


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33427

[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

[gjunk at sapience dot com]

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

--- Comment #11 from gene  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  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/