https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100160
Thomas Schwinge <tschwinge at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2023-05-19
Keywords| |openacc, openmp
CC| |tschwinge at gcc dot gnu.org
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
--- Comment #3 from Thomas Schwinge <tschwinge at gcc dot gnu.org> ---
(In reply to Brecht Sanders from comment #0)
> Several issues when using GCC built against MinGW-w64 for Windows to compile
> gomp test code (see attached minimal source code).
>
> Code compiles fine with:
> g++ -c -o test.o test.cpp -fopenmp -foffload=nvptx-none
>
> Linking fails when done like this:
> g++ -o test.exe test.o -lgomp
> mkoffload: fatal error: either '-fopenacc' or '-fopenmp' must be set
> compilation terminated.
> lto-wrapper.exe: fatal error:
> d:/prog/winlibs64-10.3.0/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/10.3.
> 0//accel/nvptx-none/mkoffload.exe returned 1 exit status
> compilation terminated.
> d:/prog/winlibs64-10.3.0/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.3.0/../
> ../../../x86_64-w64-mingw32/bin/ld.exe: error: lto-wrapper failed
> collect2.exe: error: ld returned 1 exit status
Link with '-fopenacc' or '-fopenmp' instead of '-lgomp'.
> Avoiding LTO seems to work around this and the following links fine:
> g++ -o test.exe test.o -fno-lto -lgomp
That's because "-fno-lto effectively disables offloading" (PR109819).
> When executing test.exe the output starts with:
> libgomp: while loading libgomp-plugin-nvptx.so.1:
> "libgomp-plugin-nvptx.so.1": The specified module could not be found.
>
> The correct file on Windows is libgomp-plugin-nvptx-1.dll, not
> libgomp-plugin-nvptx.so.1
ACK. GCC's OpenACC/OpenMP code offloading has only been implemented for/tested
on GNU/Linux systems. Windows support can certainly be added, but it needs
someone to do it.
