Hi Patrick! On 2023-07-25T11:37:41+0200, Patrick Begou via Gcc-help <gcc-help@xxxxxxxxxxx> wrote: > My goal is to build Gcc to use openacc offloading on AMD instinct GPUs. > I built it successfully for Nvidia GPUs some weeks ago. > > I have followed the documentation provided by > https://gcc.gnu.org/wiki/Offloading#Building_host_and_accel_compilers > > - building llvm and renaming the tools, > > - building gfortran for the device: > > ../configure --prefix=$DEST --target=amdgcn-amdhsa > --enable-languages=c,c++,lto,fortran --disable-sjlj-exceptions > --with-newlib \ > --enable-as-accelerator-for=$target > --with-build-time-tools=$DEST/bin --disable-libquadmath > > - building gfortran for the host: > > ../configure --prefix=$DEST --build=x86_64-pc-linux-gnu > --host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu --disable-multilib \ > --enable-offload-targets=nvptx-none=$DEST/nvptx-none,amdgcn-amdhsa=$DEST/amdgcn-amdhsa If you have installed all the GCN/nvptx offloading compiler(s) and the host compiler into the same '--prefix=$DEST', you shouldn't need: --enable-offload-targets=nvptx-none=$DEST/nvptx-none,amdgcn-amdhsa=$DEST/amdgcn-amdhsa ..., but instead just: --enable-offload-targets=nvptx-none,amdgcn-amdhsa (The latter is, I think, the standard configuration; for the former, while conceptually better, you need some mroe tweaks -- I shall document that at some point...) > Compilation is successful but using this new compiler I have an error > when calling it: > > $ make > gfortran -c -fopenacc -foffload='-march=gfx90a' -cpp -foffload=-lgfortran tab.f90 -o tab.o For that invocation ('-c'), there is no offloading compilation yet (that happens at link time; that's when you should specify your offloading compilation flags, via '-foffload-options=[...]'). > as: Unknown command line argument '--64'. Try: 'as --help' > as: Did you mean '-I'? > make: *** [Makefile:26: tab.o] Error 1 > > Of course the newly installer 'as' binary from llvm do not accept "--64" > option. Indeed this looks as if the host GCC is invoking the GCN 'as' (really: 'llvm-mc') as the host 'as'. Compare: $ llvm-mc --64 llvm-mc: Unknown command line argument '--64'. Try: 'llvm-mc --help' llvm-mc: Did you mean '-I'? Via your GCN '--with-build-time-tools=$DEST/bin', I suspect you've installed the GCN 'as' ('llvm-mc') as '$DEST/bin/as', and similar for the other LLVM tools? That's not correct. Instead, try installing those into a separate directory, and then point to that one for GCN GCC '--with-build-time-tools=[...]'. Hope that helps. If not, I'll look in more detail. Grüße Thomas > versions: > > - gcc: latest git master branch (24/07/2023) > > - llvm: 13.0.1 or 15.0.6 > > > Thanks for you advices. > > Patrick ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
