Re: Re: openmp support

Re: Re: openmp support

[Timothy C Prince]

-----Original Message-----
From: Thomas Yeh <tomyeh@CS.UCLA.EDU>
To: tprince@myrealbox.com
Date: Thu, 1 Jun 2006 11:30:39 -0700 (PDT)
Subject: Re: openmp support

I've tried a small test using the parallel for openmp pragma. The test
compiles but the performance looks similar to a serial version. Also, the
compiler complains when I use omp_set_num_threads and omp_get_num_threads.

Is there a flag I need to use when compiling?


-fopenmp
Tim Prince

Re: Re: openmp support

[Thomas Yeh]

  I tried -fopenmp, but it results in the following error when I run the
binary:

error while loading shared libraries: libgomp.so.1: cannot open shared
object file: No such file or directory

I've looked on the web for libgomp, but it looks like this library has
been dropped (the gomp webpage shows that gomp has been merged into the
mainline gcc), and I can't really find a copy of it.

Tom


On Thu, 1 Jun 2006, Timothy C Prince wrote:

>
>
> -----Original Message-----
> From: Thomas Yeh <tomyeh@CS.UCLA.EDU>
> To: tprince@myrealbox.com
> Date: Thu, 1 Jun 2006 11:30:39 -0700 (PDT)
> Subject: Re: openmp support
>
> I've tried a small test using the parallel for openmp pragma. The test
> compiles but the performance looks similar to a serial version. Also, the
> compiler complains when I use omp_set_num_threads and omp_get_num_threads.
>
> Is there a flag I need to use when compiling?
>
>
> -fopenmp
> Tim Prince
>

Re: openmp support

[Tim Prince]

Thomas Yeh wrote:
>   I tried -fopenmp, but it results in the following error when I run the
> binary:
> 
> error while loading shared libraries: libgomp.so.1: cannot open shared
> object file: No such file or directory
> 
> I've looked on the web for libgomp, but it looks like this library has
> been dropped (the gomp webpage shows that gomp has been merged into the
> mainline gcc), and I can't really find a copy of it.
> 
> Tom
> 
> 
> On Thu, 1 Jun 2006, Timothy C Prince wrote:
> 
>>
>> -----Original Message-----
>> From: Thomas Yeh <tomyeh@CS.UCLA.EDU>
>> To: tprince@myrealbox.com
>> Date: Thu, 1 Jun 2006 11:30:39 -0700 (PDT)
>> Subject: Re: openmp support
>>
>> I've tried a small test using the parallel for openmp pragma. The test
>> compiles but the performance looks similar to a serial version. Also, the
>> compiler complains when I use omp_set_num_threads and omp_get_num_threads.
>>
>> Is there a flag I need to use when compiling?
>>
>>
>> -fopenmp
>> Tim Prince
>>
> 

There is a configure option --disable-libgomp.  If that was set, you 
should see it by gcc -v. Not even all tested gcc targets are capable of 
building with libgomp. Otherwise, libgomp should be present:
[tim@tim_pd64 lib64]$ ls
libgcc_s.so           libgomp.so.1.0.0       libssp.la
libgcc_s.so.1         libgomp.spec           libssp_nonshared.a
libgfortran.a         libmudflap.a           libssp_nonshared.la
libgfortranbegin.a    libmudflap.la          libssp.so
libgfortranbegin.la   libmudflap.so          libssp.so.0
libgfortran.la        libmudflap.so.0        libssp.so.0.0.0
libgfortran.so        libmudflap.so.0.0.0    libstdc++.a
libgfortran.so.1      libmudflapth.a         libstdc++.la
libgfortran.so.1.0.0  libmudflapth.la        libstdc++.so
libgomp.a             libmudflapth.so        libstdc++.so.6
libgomp.la            libmudflapth.so.0      libstdc++.so.6.0.9
libgomp.so            libmudflapth.so.0.0.0  libsupc++.a
libgomp.so.1          libssp.a               libsupc++.la

Yes, there are lots of libraries in a fairly minimal build.