Use a Third-Party Compiler as a Host Compiler for DPC++ Code

This content describes the steps needed to use an external host compiler (G++*) along with the Intel® oneAPI DPC++/C++ Compiler.

In this example, you will use a host compiler to generate the host objects and perform the final link. The host compiler needs to know where to find the required headers and libraries. Follow the example instructions to build a Data Parallel C++ (DPC++) program using a G++ Compiler (g++) for host code and an Intel® oneAPI DPC++/C++ Compiler (dpcpp) for DPC++ code.

For Linux*

This example includes the following:

  1. Follow the Get Started with the Intel® oneAPI Base Toolkit for Linux* guide to set up the build environment:

    Note

    The build environment requires GCC* version 5.1 or above to be installed and accessible. 

    source /opt/intel/oneapi/setvars.sh
  2. Set up the headers and library locations: 
    export LIBDIR=<Location of libsycl.so>
export INCLUDEDIR=<Location of SYCL headers>
  3. Build the objects for your device: 
    dpcpp -c a.cpp -fPIC -o a.o
dpcpp -c b.cpp -fPIC -o b.o
  4. Create the integration header files (used by the host compiler): 
    dpcpp -fsycl-device-only -Xclang -fsycl-int-header=a_host.h a.cpp
dpcpp -fsycl-device-only -Xclang -fsycl-int-header=b_host.h b.cpp
  5. Create the host objects: 
    g++ -std=c++17 -c a.cpp -o a_host.o -include a_host.h -fPIC -I$INCLUDEDIR
g++ -std=c++17 -c b.cpp -o b_host.o -include b_host.h -fPIC -I$INCLUDEDIR
  6. Compile other C++ code (or non-DPC++ code) using G++: 
    g++ -std=c++17 main.cpp -c -fPIC -I$INCLUDEDIR
  7. Create a device object: 
    dpcpp -fPIC -fsycl -fsycl-link a.o b.o -o device.o

  8. Create an archive libuser.a that contains the necessary host and device objects:

    Note

    This step is optional. 
    ar -rcs libuser.a a_host.o b_host.o device.o
  9. Perform the final link to create a final.exe executable: 
    g++ main.o a_host.o b_host.o device.o -L$LIBDIR -lOpenCL -lsycl -o finalexe.exe

  10. Build the final.exe with an archive:

    Note

    This step is optional. 
    g++ main.o -Wl,--whole-archive libuser.a -Wl,--no-whole-archive -L$LIBDIR -lOpenCL -lsycl -o finalexe.exe

For Windows*

Windows is not supported in this release.

Options

The compiler has two options that let you use an external compiler to perform host side compilation. The options are:

Parent topic: Compilation

See Also

fsycl-host-compiler
fsycl-host-compiler-options