topic Re: Linking Fortran Objects with dpcpp objects in Intel® Fortran Compiler

Linking Fortran Objects with dpcpp objects

William_Jones — Tue, 24 May 2022 02:41:56 GMT

I am working on a mixed language program that involves Fortran and Data Parallel C++ code.

When previously working on mixed language projects, I have followed the recommended procedure of linking all of the objects with ifort such that the Fortran runtimes are linked properly. This is because of the long list of varying runtime libraries that are typically involved with Fortran linking. When C++ code is involved this would involve linking the single, additional libstdc++ library with the ifort link command.

However, now with dpcpp under Linux, when I link with ifort (adding -lsycl and -lstdc++), the resulting executable fails to run, instead throwing a "cl::sycl::runtime_error".

If I instead link with dpcpp, providing -lifcore and .../compiler/lib/intel64_lin/for_main.o, the resulting executable runs as expected.

I have also tried linking with icpx and the resulting executable again throws "cl::sycl::runtime_error".

Is it possible to link a Data Parallel C++ executable, with dpcpp generated fat objects, using the ifort or ifx compilers to obtain a functional executable that runs on the device?

I can provide a reproducer if necessary, but thought I'd start by asking the question.

Re: Linking Fortran Objects with dpcpp objects

Bahamas2021 — Tue, 24 May 2022 11:12:34 GMT

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Re: Linking Fortran Objects with dpcpp objects

jimdempseyatthecove — Tue, 24 May 2022 14:10:12 GMT

The OneAPI Fortran compiler is ifx. Try linking with the ifx compiler (you may also need to build your Fortran sources with ifx). Please report back on your success or failure in using ifx in lieu of ifort.

Jim Dempsey

Re: Linking Fortran Objects with dpcpp objects

William_Jones — Tue, 24 May 2022 15:02:55 GMT

Thank you for the response, but as I implied in the original post, I have already tried ifx without success. The results are the same as linking with ifort, it throws the exception.

Re:Linking Fortran Objects with dpcpp objects

Barbara_P_Intel — Tue, 24 May 2022 15:22:36 GMT

I helped another user with a similar issue. The Fortran code does not offload. This worked for him:

+ dpcpp -c device.cpp

+ ifx -qopenmp -fsycl host.f90 device.o -lstdc++ -lOpenCL -lsycl

Re: Re:Linking Fortran Objects with dpcpp objects

William_Jones — Tue, 24 May 2022 16:41:14 GMT

Thank you! The "-qopenmp" and "-fsycl" command line options to ifx were what fixed it for me. Thanks again!