[PATCH] D94745: [OpenMP][deviceRTLs] Build the deviceRTLs with OpenMP instead of target dependent language

[Joachim Protze via Phabricator via cfe-commits]

protze.joachim added a comment.

For me this patch breaks building llvm. Before this patch, I successfully built llvm using a llvm/10 installation on the system. What is probably special with our llvm installation is that we by default use libc++ rather than libstdc++.

  FAILED: projects/openmp/libomptarget/deviceRTLs/nvptx/loop.cu-cuda_110-sm_60.bc 
  cd BUILD/projects/openmp/libomptarget/deviceRTLs/nvptx && /home/pj416018/sw/UTIL/ccache/bin/clang -S -x c++ -target nvptx64 -Xclang -emit-llvm-bc -Xclang -aux-triple -Xclang x86_64-unknown-linux-gnu -fopenmp -fopenmp-cuda-mode -Xclang -fopenmp-is-device -D__CUDACC__ -I${llvm-SOURCE}/openmp/libomptarget/deviceRTLs -I${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/nvptx/src -DOMPTARGET_NVPTX_DEBUG=0 -Xclang -target-cpu -Xclang sm_60 -D__CUDA_ARCH__=600 -Xclang -target-feature -Xclang +ptx70 -DCUDA_VERSION=11000 ${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/common/src/loop.cu -o loop.cu-cuda_110-sm_60.bc
  In file included from ${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/common/src/loop.cu:16:
  In file included from ${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/common/omptarget.h:18:
  In file included from ${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/common/debug.h:31:
  In file included from ${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/common/device_environment.h:16:
  In file included from ${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.h:18:
  In file included from ${llvm-INSTALL}/10.0.0/bin/../include/c++/v1/stdlib.h:100:
  In file included from ${llvm-INSTALL}/10.0.0/bin/../include/c++/v1/math.h:312:
  ${llvm-INSTALL}/10.0.0/bin/../include/c++/v1/limits:406:89: error: host requires 128 bit size 'std::__1::__libcpp_numeric_limits<long double, true>::type' (aka 'long double') type support, but device 'nvptx64' does not support it
      _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return -max();}
                                                                                          ^~~~~

My cmake call looks like:

  cmake -GNinja -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_INSTALL_PREFIX=$INSTALLDIR \
    -DLLVM_ENABLE_LIBCXX=ON \
    -DCLANG_DEFAULT_CXX_STDLIB=libc++ \
    -DCLANG_OPENMP_NVPTX_DEFAULT_ARCH=sm_70 \
    -DLIBOMPTARGET_ENABLE_DEBUG=on \
    -DLIBOMPTARGET_NVPTX_ENABLE_BCLIB=true \
    -DLIBOMPTARGET_NVPTX_COMPUTE_CAPABILITIES=35,60,70 \
    -DLLVM_ENABLE_PROJECTS="clang;compiler-rt;libcxxabi;libcxx;libunwind;openmp" \
    -DCMAKE_BUILD_WITH_INSTALL_RPATH=ON \
    $LLVM_SOURCE

I also tried to build using my newest installed llvm build (7dd198852b4db52ae22242dfeda4eccda83aa8b2 <https://reviews.llvm.org/rG7dd198852b4db52ae22242dfeda4eccda83aa8b2>):

  In file included from ${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.cu:14:
  In file included from ${llvm-SOURCE}/openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.h:18:
  ${llvm-INSTALL}/bin/../include/c++/v1/stdlib.h:128:10: error: '__builtin_fabsl' requires 128 bit size 'long double' type support, but device 'nvptx64' does not support it
    return __builtin_fabsl(__lcpp_x);
           ^


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D94745/new/

https://reviews.llvm.org/D94745