Author: Joseph Huber Date: 2022-05-25T16:30:53-04:00 New Revision: b7c8c4d8cf07d2e9e8cd157bccc8bd9e7c76415a
URL: https://github.com/llvm/llvm-project/commit/b7c8c4d8cf07d2e9e8cd157bccc8bd9e7c76415a DIFF: https://github.com/llvm/llvm-project/commit/b7c8c4d8cf07d2e9e8cd157bccc8bd9e7c76415a.diff LOG: [Clang] Introduce `--offload-link` option to perform offload device linking The new driver uses an augmented linker wrapper to perform the device linking phase, but to the user looks like a regular linker invocation. Contrary to the old driver, the new driver contains all the information necessary to produce a linked device image in the host object itself. Currently, we infer the usage of the device linker by the user specifying an offloading toolchain, e.g. (--offload-arch=...) or (-fopenmp-targets=...), but this shouldn't be strictly necessary. This patch introduces a new option `--offload-link` to tell the driver to use the offloading linker instead. So a compilation flow can now look like this, ``` clang foo.cu --offload-new-driver -fgpu-rdc --offload-arch=sm_70 -c clang foo.o --offload-link -lcudart ``` I was considering if this could be merged into the `-fuse-ld` option, but because the device linker wraps over the users linker it would conflict with that. In the future it's possible to merge this into `lld` completely or `gold` via a plugin and we would use this option to enable the device linking feature. Let me know what you think for this. Reviewed By: tra Differential Revision: https://reviews.llvm.org/D126398 Added: Modified: clang/docs/ClangCommandLineReference.rst clang/include/clang/Driver/Options.td clang/lib/Driver/Driver.cpp clang/test/Driver/cuda-openmp-driver.cu Removed: ################################################################################ diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst index 5926decc85fc..73dccf6a9a04 100644 --- a/clang/docs/ClangCommandLineReference.rst +++ b/clang/docs/ClangCommandLineReference.rst @@ -4209,6 +4209,10 @@ Set starting address of TEXT to <addr> Pass the comma separated arguments in <arg> to the linker +.. option:: --offload-link + +Use the linker supporting offloading device linking. + .. option:: -X .. option:: -Xlinker <arg>, --for-linker <arg>, --for-linker=<arg> diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index d34cec766a2e..e19baac5860a 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -820,6 +820,8 @@ def Xopenmp_target_EQ : JoinedAndSeparate<["-"], "Xopenmp-target=">, Group<Compi def z : Separate<["-"], "z">, Flags<[LinkerInput, RenderAsInput]>, HelpText<"Pass -z <arg> to the linker">, MetaVarName<"<arg>">, Group<Link_Group>; +def offload_link : Flag<["--"], "offload-link">, Group<Link_Group>, + HelpText<"Use the new offloading linker to perform the link job.">; def Xlinker : Separate<["-"], "Xlinker">, Flags<[LinkerInput, RenderAsInput]>, HelpText<"Pass <arg> to the linker">, MetaVarName<"<arg>">, Group<Link_Group>; diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp index 3edbaed9ae7f..94925568aec2 100644 --- a/clang/lib/Driver/Driver.cpp +++ b/clang/lib/Driver/Driver.cpp @@ -4158,7 +4158,8 @@ void Driver::BuildActions(Compilation &C, DerivedArgList &Args, // Check if this Linker Job should emit a static library. if (ShouldEmitStaticLibrary(Args)) { LA = C.MakeAction<StaticLibJobAction>(LinkerInputs, types::TY_Image); - } else if (UseNewOffloadingDriver) { + } else if (UseNewOffloadingDriver || + Args.hasArg(options::OPT_offload_link)) { LA = C.MakeAction<LinkerWrapperJobAction>(LinkerInputs, types::TY_Image); LA->propagateHostOffloadInfo(C.getActiveOffloadKinds(), /*BoundArch=*/nullptr); diff --git a/clang/test/Driver/cuda-openmp-driver.cu b/clang/test/Driver/cuda-openmp-driver.cu index dec0288db263..b27195da2fb1 100644 --- a/clang/test/Driver/cuda-openmp-driver.cu +++ b/clang/test/Driver/cuda-openmp-driver.cu @@ -35,3 +35,8 @@ // RUN: %clang -### -target x86_64-linux-gnu -nocudalib --cuda-feature=+ptx61 --offload-arch=sm_70 %s 2>&1 | FileCheck -check-prefix MANUAL-FEATURE %s // MANUAL-FEATURE: -cc1{{.*}}-target-feature{{.*}}+ptx61 + +// RUN: %clang -### -target x86_64-linux-gnu -nocudalib -ccc-print-bindings --offload-link %s 2>&1 \ +// RUN: | FileCheck -check-prefix DEVICE-LINK %s + +// DEVICE-LINK: "x86_64-unknown-linux-gnu" - "Offload::Linker", inputs: ["[[INPUT:.+]]"], output: "a.out" _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
