Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] OpenMPI 1.3.2 with PathScale 3.2
From: David O. Gunter (dog_at_[hidden])
Date: 2009-05-15 09:17:25


Pathscale supports -O3 (at least as of the 3.1 line). Here are some
suggestions from the 3.2 Users Manual you may also want to try.

-david

If there are numerical problems with -O3 -OPT:Ofast, then try either of the
following:

  -O3 -OPT:Ofast:ro=1
  -O3 -OPT:Ofast:div_split=OFF

Note that ’ro’ is short for roundoff.

-Ofast is equivalent to -O3 -ipa -OPT:Ofast -fno-math-errno -ffast-math
so similar cautions apply to it as to -O3 -OPT:Ofast.

To use interprocedural analysis without the "Ofast-type" optimizations,
use either of the following:
  -O3 -ipa
  -O2 -ipa

Testing different optimizations can be automated by pathopt2. This program
compiles and runs your program with a variety of compiler options and
creates a sorted list of the execution times for each run.

--
David Gunter
Los Alamos National Laboratory
> Last I checked when we were building here, I'm not sure Pathscale
> supports -O3. IIRC, O2 is the max supported value, though it has been
> awhile since I played with it.
>
> Have you checked the man page for it?
>
> It could also be something in the VampirTrace code since that is where
> you are failing. That is a contributed code - not part of OMPI itself
> - so we would have to check with those developers.
>
>
> On May 14, 2009, at 2:49 PM, Åke Sandgren wrote:
>
>> On Thu, 2009-05-14 at 13:35 -0700, Joshua Bernstein wrote:
>>> Greetings All,
>>>
>>> 	I'm trying to build OpenMPI 1.3.2 with the Pathscale compiler,
>>> version 3.2. A
>>> bit of the way through the build the compiler dies with what it
>>> things is a bad
>>> optimization. Has anybody else seen this, or know a work around for
>>> it? I'm
>>> going to take it up with Pathscale of course, but I thought I'd
>>> throw it out here:
>>>
>>> ---SNIP---
>>> /opt/pathscale/bin/pathCC -DHAVE_CONFIG_H -I. -I../.. -I../../
>>> extlib/otf/otflib
>>> -I../../extlib/otf/otflib -I../../vtlib/ -I../../vtlib  -
>>> D_GNU_SOURCE -mp
>>> -DVT_OMP -O3 -DNDEBUG -finline-functions -pthread -MT vtfilter-
>>> vt_tracefilter.o
>>> -MD -MP -MF .deps/vtfilter-vt_tracefilter.Tpo -c -o vtfilter-
>>> vt_tracefilter.o
>>> `test -f 'vt_tracefilter.cc' || echo './'`vt_tracefilter.cc
>>> Signal: Segmentation fault in Global Optimization -- Dead Store
>>> Elimination phase.
>>> Error: Signal Segmentation fault in phase Global Optimization --
>>> Dead Store
>>> Elimination -- processing aborted
>>> *** Internal stack backtrace:
>>> pathCC INTERNAL ERROR: /opt/pathscale/lib/3.2/be died due to signal 4
>>
>> Haven't seen it. But I'm only using -O2 when building openmpi.
>> Report it quickly, if we're lucky they might get a fix into the 3.3
>> release that is due out very soon. (I just got the beta yesterday)
>>
>> --
>> Ake Sandgren, HPC2N, Umea University, S-90187 Umea, Sweden
>> Internet: ake_at_[hidden]   Phone: +46 90 7866134 Fax: +46 90 7866126
>> Mobile: +46 70 7716134 WWW: http://www.hpc2n.umu.se
>>
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>
>
> _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users
>