[Bug fortran/96797] New: OpenACC fortran acc_get_cuda_stream

[Bug fortran/96797] New: OpenACC fortran acc_get_cuda_stream

[samunaga at amd dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96797

            Bug ID: 96797
           Summary: OpenACC fortran acc_get_cuda_stream
           Product: gcc
           Version: 10.1.0
            Status: UNCONFIRMED
          Keywords: openacc
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: samunaga at amd dot com
  Target Milestone: ---

Created attachment 49130
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49130&action=edit
source_code.txt contains source code for all the 3 files

When compiling OpenACC fortran code fft.f90 which calls a function defined in
cufft.cu file, we are getting the below error

Error:
Function 'acc_get_cuda_stream' at (1) has no IMPLICIT type

Steps to reproduce the error:

nvcc -c --compiler-bindir /usr/bin/ cufft.cu (using GCC7.5.0 for NVCC)
gfortran -fopenacc -o fftf fft.f90 cufft.o -lm -lcufft
-L/usr/local/cuda-10.2/targets/x86_64-linux/lib/ -lcudart

CUDA version: 10.2
GCC version: 10.1

When compiling the equivalent C code(fftc.c), the executable got build without
any errors.

Steps for compilation:
nvcc -c --compiler-bindir /usr/bin/ cufft.cu (using GCC7.5.0 for NVCC)
gcc -fopenacc -o fftc fftc.c cufft.o -lcufft -lcudart
-L/usr/local/cuda-10.2/targets/x86_64-linux/lib

Please find attached source code for cufft.cu,fft.f90,fftc.c

We observed that, acc_get_cuda_stream is declared in openacc.h file(C
implementaion uses this)
But acc_get_cuda_stream is not declared in openacc.f90 file(fortran
implementation uses openacc.mod)

[Bug fortran/96797] OpenACC fortran acc_get_cuda_stream

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96797

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to Pavan from comment #0)
> We observed that, acc_get_cuda_stream is declared in openacc.h file(C
> implementaion uses this)
> But acc_get_cuda_stream is not declared in openacc.f90 file(fortran
> implementation uses openacc.mod)

If you look at section A.2 of either OpenACC 2.6 (supported by GCC)
https://www.openacc.org/sites/default/files/inline-files/OpenACC.2.6.final.pdf
or in 3.0 (latest version) you only find the C/C++ version:
https://www.openacc.org/sites/default/files/inline-images/Specification/OpenACC.3.0.pdf

I note that there is an attempt to add a Fortran C-binding interface to it at
https://sourceforge.net/projects/fortcuda/ (does not seem to be very active).

That would be also my proposal to you as quick solution: Simply create an
INTERFACE for them using BIND(C).

[Bug fortran/96797] OpenACC fortran acc_get_cuda_stream

[tschwinge at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96797

Thomas Schwinge <tschwinge at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |WAITING
           See Also|                            |https://github.com/OpenACC/
                   |                            |openacc-spec/issues/25
                 CC|                            |tschwinge at gcc dot gnu.org
   Last reconfirmed|                            |2021-07-01