diff --git a/clang/docs/ClangNvlinkWrapper.rst b/clang/docs/ClangNvlinkWrapper.rst new file mode 100644 --- /dev/null +++ b/clang/docs/ClangNvlinkWrapper.rst @@ -0,0 +1,51 @@ +===================== +Clang Nvlink Wrapper +===================== + +.. contents:: + :local: + +.. _clang-nvlink-wrapper: + +Introduction +============ + +This tool works as a wrapper over nvlink program. It is required because nvlink does not +support linking of archive files implicitly. It transparently passes every +input option and objects to nvlink except archive files. It reads each input +archive file to extract archived cubin files as temporary files. +These temp (*.cubin) files are passed to nvlink. + +During linking of heterogenous device archive libraries with an OpenMP program, +the `Clang Offload Bundler `_ +creates a device specific archive of cubin files. Such an archive is then +passed to this wrapper tool to extract cubin files before passing to nvlink. + +Working +======= + +**Inputs** + + A command line generated by the OpenMP-Clang driver targeting NVPTX, containing a set of flags, cubin object files, and zero or more archive files + +Example:: + + clang-nvlink-wrapper main.cubin /tmp/libTest-nvptx-sm_50.a -o a.out-openmp-nvptx64 + +**Processing** + + 1. From each archive file extract all cubin files as temporary files and store their names in a list, CubinFiles. + 2. Create a new command line, `NVLinkCommand`, such that + * Program is nvlink + * All input flags are transparently passed on as flags + * All input archive file are replaced with CubinFiles + 3. Execute NVLinkCommand + +:: + + 1. Extract (libTest-nvptx-sm_50.a) => /tmp/a.cubin /tmp/b.cubin + 2. nvlink -o a.out-openmp-nvptx64 main.cubin /tmp/a.cubin /tmp/b.cubin + +**Output** + + Output file generated by nvlink by linking all cubin files. \ No newline at end of file diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -147,7 +147,9 @@ OpenMP Support in Clang ----------------------- -- ... +- clang-nvlink-wrapper tool introduced to support linking of cubin files + archived in an archive. See `Clang Nvlink Wrapper `_ . + CUDA Support in Clang --------------------- diff --git a/clang/docs/index.rst b/clang/docs/index.rst --- a/clang/docs/index.rst +++ b/clang/docs/index.rst @@ -80,6 +80,7 @@ ClangFormat ClangFormatStyleOptions ClangFormattedStatus + ClangNvlinkWrapper ClangOffloadBundler Design Documents diff --git a/clang/tools/clang-nvlink-wrapper/ClangNvlinkWrapper.cpp b/clang/tools/clang-nvlink-wrapper/ClangNvlinkWrapper.cpp --- a/clang/tools/clang-nvlink-wrapper/ClangNvlinkWrapper.cpp +++ b/clang/tools/clang-nvlink-wrapper/ClangNvlinkWrapper.cpp @@ -13,7 +13,7 @@ /// These temp (*.cubin) files are passed to nvlink, because nvlink does not /// support linking of archive files implicitly. /// -/// During linking of heteregenous device archive libraries, the +/// During linking of heterogenous device archive libraries, the /// clang-offload-bundler creates a device specific archive of cubin files. /// Such an archive is then passed to this tool to extract cubin files before /// passing to nvlink. @@ -60,7 +60,7 @@ std::vector> ArchiveBuffers; ErrorOr> BufOrErr = - MemoryBuffer::getFileOrSTDIN(Filename, -1, false); + MemoryBuffer::getFileOrSTDIN(Filename, false, false); if (std::error_code EC = BufOrErr.getError()) return createFileError(Filename, EC);