[Openmp-dev] Math symbols are not found during configuration

Jeff Hammond via Openmp-dev openmp-dev at lists.llvm.org
Wed Jul 24 14:57:15 PDT 2019


I am curious how this works.  Does the compiler not #include all headers or
specific headers when the target compiler is running?

I make heavy use of preprocessing in all of my OpenMP codes, including the
target ones.  I don't compile for the NVPTX back-end so I haven't seen
problems yet but I wonder if my code is broken in that setting.

Jeff

On Wed, Jul 24, 2019 at 1:32 PM Doerfert, Johannes <jdoerfert at anl.gov>
wrote:

> #define works, the preprocessor works.
>
> When the target region is compiled we do not include math.h. This will
> change once we get support for variants. Till then, it is either no math
> functions or only he ones Clang CUDA provides automatically, which seems
> not to include these defines, maybe because they are not ISO C but POSIX
> extensions.
>
>
> On 07/24, Jeff Hammond wrote:
> > How does #define not act on the full source code? How is that a
> compliant implementation of the preprocessor?
> >
> > Jeff
> >
> > > On Jul 24, 2019, at 12:25 PM, Doerfert, Johannes via Openmp-dev <
> openmp-dev at lists.llvm.org> wrote:
> > >
> > > Hi Itaru,
> > >
> > > For now, you need to define them yourself when you need them in the
> target region.
> > > We are working on a permanent solution.
> > >
> > > Thanks,
> > >  Johannes
> > >
> > > ________________________________________
> > > From: Openmp-dev <openmp-dev-bounces at lists.llvm.org> on behalf of
> Itaru Kitayama via Openmp-dev <openmp-dev at lists.llvm.org>
> > > Sent: Tuesday, July 23, 2019 22:58
> > > To: openmp-dev at lists.llvm.org
> > > Subject: [Openmp-dev] Math symbols are not found during configuration
> > >
> > > Hi,
> > > Adding the flag -fopenmp-targets=nvptx64 makes math symbols M_E and
> M_PI defined in cmath not detected during the execution of CMake. How do I
> work around this? I am using the latest trunk Clang at this moment, and
> without the above flag, both symbols are detected properly.
> > >
> > > Thanks,
> > > Itaru.
> > > _______________________________________________
> > > Openmp-dev mailing list
> > > Openmp-dev at lists.llvm.org
> > > https://lists.llvm.org/cgi-bin/mailman/listinfo/openmp-dev
>
> --
>
> Johannes Doerfert
> Researcher
>
> Argonne National Laboratory
> Lemont, IL 60439, USA
>
> jdoerfert at anl.gov
>


-- 
Jeff Hammond
jeff.science at gmail.com
http://jeffhammond.github.io/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/openmp-dev/attachments/20190724/84d75d59/attachment-0001.html>


More information about the Openmp-dev mailing list