[llvm-dev] PTX generation from CUDA file for compute capability 1.0 (sm_10)

[ginu jacob via llvm-dev]

Previously when I started with installation of LLVM and CUDA, I had a very
bad time with the error "Unsupported CUDA version!". I remember it now and
dig down a bit into the LLVM source code. In the LLVM file
*llvm/tools/clang/lib/Headers/__clang_cuda_runtime_wrapper.h *
*(http://clang.llvm.org/doxygen/cuda__runtime_8h_source.html
<http://clang.llvm.org/doxygen/cuda__runtime_8h_source.html>)*
there is a check for the CUDA_VERSION and it allows only versions between 7
and 7.05. So is there a handy way of checking this file for previous LLVM
versions so that I can avoid heading into a catastrophe which I am certain
about and give a better chance for success...



On Thu, Jun 2, 2016 at 3:34 PM, C Bergström <cbergstrom at pathscale.com>
wrote:

> I think you may have answered your own question - If CUDA 7.5 doesn't
> support sm_10 then you'll eventually hit that as a problem. So yes if
> possible make sure you're installing a version of CUDA toolkit which
> supports the target you need.
>
> I'm not certain the exact compilation flow when fighting this, but
> ensure the underlying nvcc and ptxas work first for sm_10 before
> trying to get llvm involved.
>
> On Thu, Jun 2, 2016 at 3:23 PM, ginu jacob <ginujacob10 at gmail.com> wrote:
> > Hello Bergström/Eric,
> >
> > Thanks for the reply. The G80(sm_10) architecture was ported on FPGA by a
> > group of researchers
> > (http://www.ecs.umass.edu/ece/tessier/andryc-fpt13.pdf). Our group have
> some
> > further research interest on this work. I was working on modifying the
> > Clang-LLVM for a couple of months and achieved the required changes. But
> > Clang-LLVM is only allowing me to generate PTX for sm_20, sm_30 etc.While
> > trying to generate PTX for sm_10, it gave
> >
> > error: unknown target CPU 'sm_10'
> > fatal error: cannot open file '/tmp/shared-395893.s': No such file or
> > directory
> > 1 error generated.
> >
> >
> > The compilation command used is:
> > clang -Xclang -I$LIBCLC/include/generic -I$LIBCLC/include/ptx
> > -Dcl_clang_storage_class_specifiers -O3 CudaSource.cu -S -o PtxOutput.ptx
> > --cuda-gpu-arch=sm_10
> >
> > Is there any chance that this error being generated from CUDA runtime
> alone
> > since I am using CUDA 7.5 which does not support sm_10. If there is any
> > chance that the error is isolated from LLVM and is only due to CUDA, i
> have
> > some hope to use a lower CUDA version. Please let me know your
> suggestions.
> >
> > Thank you,
> > Ginu
> >
> >
> > On Thu, Jun 2, 2016 at 2:36 PM, C Bergström <cbergstrom at pathscale.com>
> > wrote:
> >>
> >> What happens if you hack change llvm to accept sm_10? Do you get an
> >> error somewhere further down the pipeline?
> >>
> >> sm_10 is pretty old hardware - Why the strong dependency on this?
> >>
> >> On Thu, Jun 2, 2016 at 1:18 PM, ginu jacob via llvm-dev
> >> <llvm-dev at lists.llvm.org> wrote:
> >> > Hello,
> >> >
> >> > When generating the PTX output from CUDA file(.cu file), the minimum
> >> > target
> >> > that is accepted by LLVM is sm_20. But I have a specific requirement
> to
> >> > generate PTX output for compute capability 1.0 (sm_10). Is there any
> >> > previous version of LLVM supporting this?
> >> >
> >> > Thank you,
> >> > Ginu
> >> >
> >> > _______________________________________________
> >> > LLVM Developers mailing list
> >> > llvm-dev at lists.llvm.org
> >> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >> >
> >
> >
>
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