Author: Nick Sarnie Date: 2026-01-06T15:10:41Z New Revision: 53f84636eb86e6c64c1ec405f70b3dd2b27f4ddc
URL: https://github.com/llvm/llvm-project/commit/53f84636eb86e6c64c1ec405f70b3dd2b27f4ddc DIFF: https://github.com/llvm/llvm-project/commit/53f84636eb86e6c64c1ec405f70b3dd2b27f4ddc.diff LOG: [clang][Driver][SPIR-V] Allow linking IR using llvm-link (#169572) SPIR-V does not have a production-grade linker so it is often necessary to stay in LLVM-IR as long as possible and only convert to SPIR-V at the very end. As such, it is common that we want to create a BC library that is linked into a user program (motivating example here is the OpenMP device RTL). We only convert to SPIR-V at the very end when we have a fully linked program. Other targets can achieve a similar goal by using LTO to get a linked-BC file, but the SPIR-V linker does not support LTO, so we have no way to do it with `clang`. We can do it with `llvm-link` directly, but my understanding is that it is not intended to be directly called in production workflows and does not fit well into code that supports multiple targets. Extend the existing behavior for `HIP` that allows `-emit-llvm` without `-c`. --------- Signed-off-by: Nick Sarnie <[email protected]> Added: clang/test/Driver/spirv-llvm-link-emit-asm.c clang/test/Driver/spirv-llvm-link.c Modified: clang/include/clang/Driver/CommonArgs.h clang/lib/Driver/Driver.cpp clang/lib/Driver/ToolChains/CommonArgs.cpp clang/lib/Driver/ToolChains/HIPAMD.cpp clang/lib/Driver/ToolChains/HIPAMD.h clang/lib/Driver/ToolChains/HIPSPV.cpp clang/lib/Driver/ToolChains/SPIRV.cpp clang/lib/Driver/ToolChains/SPIRV.h clang/test/Driver/hipspv-link-static-library.hip clang/test/Driver/hipspv-toolchain-rdc.hip clang/test/Driver/hipspv-toolchain.hip Removed: ################################################################################ diff --git a/clang/include/clang/Driver/CommonArgs.h b/clang/include/clang/Driver/CommonArgs.h index 264bd4965f9ad..dfa0f81adc2e3 100644 --- a/clang/include/clang/Driver/CommonArgs.h +++ b/clang/include/clang/Driver/CommonArgs.h @@ -302,6 +302,17 @@ void setComplexRange(const Driver &D, StringRef NewOpt, LangOptions::ComplexRangeKind NewRange, StringRef &LastOpt, LangOptions::ComplexRangeKind &Range); +// This function expects that the inputs to llvm-link will be specified by the +// caller, but the output is handled by this function, with the optional ability +// to set the output filename. +void constructLLVMLinkCommand(Compilation &C, const Tool &T, + const JobAction &JA, + const InputInfoList &JobInputs, + const llvm::opt::ArgStringList &LinkerInputs, + const InputInfo &Output, + const llvm::opt::ArgList &Args, + const char *OutputFilename = nullptr); + } // end namespace tools } // end namespace driver } // end namespace clang diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp index b2828ebc5a4f6..eb3f9cbea2845 100644 --- a/clang/lib/Driver/Driver.cpp +++ b/clang/lib/Driver/Driver.cpp @@ -4229,8 +4229,11 @@ void Driver::handleArguments(Compilation &C, DerivedArgList &Args, Args.AddFlagArg(nullptr, getOpts().getOption(options::OPT_frtlib_add_rpath)); } - // Emitting LLVM while linking disabled except in HIPAMD Toolchain - if (Args.hasArg(options::OPT_emit_llvm) && !Args.hasArg(options::OPT_hip_link)) + // Emitting LLVM while linking disabled except in the HIPAMD or SPIR-V + // Toolchains + if (Args.hasArg(options::OPT_emit_llvm) && + !Args.hasArg(options::OPT_hip_link) && + !C.getDefaultToolChain().getTriple().isSPIRV()) Diag(clang::diag::err_drv_emit_llvm_link); if (C.getDefaultToolChain().getTriple().isWindowsMSVCEnvironment() && LTOMode != LTOK_None && @@ -4505,7 +4508,14 @@ void Driver::BuildActions(Compilation &C, DerivedArgList &Args, LA->propagateHostOffloadInfo(C.getActiveOffloadKinds(), /*BoundArch=*/nullptr); } else { - LA = C.MakeAction<LinkJobAction>(LinkerInputs, types::TY_Image); + // If we are linking but were passed -emit-llvm, we will be calling + // llvm-link, so set the output type accordingly. This is only allowed in + // rare cases, so make sure we aren't going to error about it. + bool LinkingIR = Args.hasArg(options::OPT_emit_llvm) && + C.getDefaultToolChain().getTriple().isSPIRV(); + types::ID LT = LinkingIR && !Diags.hasErrorOccurred() ? types::TY_LLVM_BC + : types::TY_Image; + LA = C.MakeAction<LinkJobAction>(LinkerInputs, LT); } if (!UseNewOffloadingDriver) LA = OffloadBuilder->processHostLinkAction(LA); diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp index 882283a99d4f1..b005604821e27 100644 --- a/clang/lib/Driver/ToolChains/CommonArgs.cpp +++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp @@ -3462,3 +3462,28 @@ void tools::setComplexRange(const Driver &D, StringRef NewOpt, LastOpt = NewOpt; Range = NewRange; } + +void tools::constructLLVMLinkCommand(Compilation &C, const Tool &T, + const JobAction &JA, + const InputInfoList &JobInputs, + const ArgStringList &LinkerInputs, + const InputInfo &Output, + const llvm::opt::ArgList &Args, + const char *OutputFilename) { + // Construct llvm-link command. + // The output from llvm-link is a bitcode file. + + assert(!LinkerInputs.empty() && !JobInputs.empty() && + "Must have at least one input."); + + ArgStringList LlvmLinkArgs( + {"-o", OutputFilename ? OutputFilename : Output.getFilename()}); + + LlvmLinkArgs.append(LinkerInputs); + + const ToolChain &TC = T.getToolChain(); + const char *LlvmLink = Args.MakeArgString(TC.GetProgramPath("llvm-link")); + C.addCommand(std::make_unique<Command>(JA, T, ResponseFileSupport::None(), + LlvmLink, LlvmLinkArgs, JobInputs, + Output)); +} diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp index f2f64922cb404..617809285c165 100644 --- a/clang/lib/Driver/ToolChains/HIPAMD.cpp +++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp @@ -33,32 +33,22 @@ using namespace llvm::opt; #define NULL_FILE "/dev/null" #endif -void AMDGCN::Linker::constructLlvmLinkCommand(Compilation &C, - const JobAction &JA, - const InputInfoList &Inputs, - const InputInfo &Output, - const llvm::opt::ArgList &Args) const { - // Construct llvm-link command. - // The output from llvm-link is a bitcode file. - ArgStringList LlvmLinkArgs; +void AMDGCN::Linker::constructLLVMLinkCommand( + Compilation &C, const JobAction &JA, const InputInfoList &Inputs, + const InputInfo &Output, const llvm::opt::ArgList &Args) const { - assert(!Inputs.empty() && "Must have at least one input."); + ArgStringList LinkerInputs; - LlvmLinkArgs.append({"-o", Output.getFilename()}); for (auto Input : Inputs) - LlvmLinkArgs.push_back(Input.getFilename()); + LinkerInputs.push_back(Input.getFilename()); // Look for archive of bundled bitcode in arguments, and add temporary files // for the extracted archive of bitcode to inputs. auto TargetID = Args.getLastArgValue(options::OPT_mcpu_EQ); - AddStaticDeviceLibsLinking(C, *this, JA, Inputs, Args, LlvmLinkArgs, "amdgcn", + AddStaticDeviceLibsLinking(C, *this, JA, Inputs, Args, LinkerInputs, "amdgcn", TargetID, /*IsBitCodeSDL=*/true); - - const char *LlvmLink = - Args.MakeArgString(getToolChain().GetProgramPath("llvm-link")); - C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(), - LlvmLink, LlvmLinkArgs, Inputs, - Output)); + tools::constructLLVMLinkCommand(C, *this, JA, Inputs, LinkerInputs, Output, + Args); } void AMDGCN::Linker::constructLldCommand(Compilation &C, const JobAction &JA, @@ -176,7 +166,7 @@ void AMDGCN::Linker::constructLinkAndEmitSpirvCommand( Args.hasFlag(options::OPT_use_spirv_backend, options::OPT_no_use_spirv_backend, /*Default=*/false); - constructLlvmLinkCommand(C, JA, Inputs, LinkedBCFile, Args); + constructLLVMLinkCommand(C, JA, Inputs, LinkedBCFile, Args); if (UseSPIRVBackend) { // This code handles the case in the new driver when --offload-device-only @@ -228,7 +218,7 @@ void AMDGCN::Linker::ConstructJob(Compilation &C, const JobAction &JA, Args, *this); if (JA.getType() == types::TY_LLVM_BC) - return constructLlvmLinkCommand(C, JA, Inputs, Output, Args); + return constructLLVMLinkCommand(C, JA, Inputs, Output, Args); if (getToolChain().getEffectiveTriple().isSPIRV()) return constructLinkAndEmitSpirvCommand(C, JA, Inputs, Output, Args); diff --git a/clang/lib/Driver/ToolChains/HIPAMD.h b/clang/lib/Driver/ToolChains/HIPAMD.h index 30fc01a2f8e40..7c6540fff235a 100644 --- a/clang/lib/Driver/ToolChains/HIPAMD.h +++ b/clang/lib/Driver/ToolChains/HIPAMD.h @@ -37,7 +37,7 @@ class LLVM_LIBRARY_VISIBILITY Linker final : public Tool { void constructLldCommand(Compilation &C, const JobAction &JA, const InputInfoList &Inputs, const InputInfo &Output, const llvm::opt::ArgList &Args) const; - void constructLlvmLinkCommand(Compilation &C, const JobAction &JA, + void constructLLVMLinkCommand(Compilation &C, const JobAction &JA, const InputInfoList &Inputs, const InputInfo &Output, const llvm::opt::ArgList &Args) const; diff --git a/clang/lib/Driver/ToolChains/HIPSPV.cpp b/clang/lib/Driver/ToolChains/HIPSPV.cpp index be0f49d8e1497..f797573a5725d 100644 --- a/clang/lib/Driver/ToolChains/HIPSPV.cpp +++ b/clang/lib/Driver/ToolChains/HIPSPV.cpp @@ -69,11 +69,8 @@ void HIPSPV::Linker::constructLinkAndEmitSpirvCommand( "generic"; // SPIR-V is generic, no specific target ID like -mcpu tools::AddStaticDeviceLibsLinking(C, *this, JA, Inputs, Args, LinkArgs, Arch, Target, /*IsBitCodeSDL=*/true); - LinkArgs.append({"-o", TempFile}); - const char *LlvmLink = - Args.MakeArgString(getToolChain().GetProgramPath("llvm-link")); - C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(), - LlvmLink, LinkArgs, Inputs, Output)); + tools::constructLLVMLinkCommand(C, *this, JA, Inputs, LinkArgs, Output, Args, + TempFile); // Post-link HIP lowering. diff --git a/clang/lib/Driver/ToolChains/SPIRV.cpp b/clang/lib/Driver/ToolChains/SPIRV.cpp index 4a870847487bf..81fd2afc6e9c7 100644 --- a/clang/lib/Driver/ToolChains/SPIRV.cpp +++ b/clang/lib/Driver/ToolChains/SPIRV.cpp @@ -75,6 +75,20 @@ void SPIRV::constructAssembleCommand(Compilation &C, const Tool &T, Exec, CmdArgs, Input, Output)); } +void SPIRV::constructLLVMLinkCommand(Compilation &C, const Tool &T, + const JobAction &JA, + const InputInfo &Output, + const InputInfoList &Inputs, + const llvm::opt::ArgList &Args) { + + ArgStringList LlvmLinkArgs; + + for (auto Input : Inputs) + LlvmLinkArgs.push_back(Input.getFilename()); + + tools::constructLLVMLinkCommand(C, T, JA, Inputs, LlvmLinkArgs, Output, Args); +} + void SPIRV::Translator::ConstructJob(Compilation &C, const JobAction &JA, const InputInfo &Output, const InputInfoList &Inputs, @@ -126,6 +140,10 @@ void SPIRV::Linker::ConstructJob(Compilation &C, const JobAction &JA, const InputInfoList &Inputs, const ArgList &Args, const char *LinkingOutput) const { + if (JA.getType() == types::TY_LLVM_BC) { + constructLLVMLinkCommand(C, *this, JA, Output, Inputs, Args); + return; + } const ToolChain &ToolChain = getToolChain(); std::string Linker = ToolChain.GetProgramPath(getShortName()); ArgStringList CmdArgs; diff --git a/clang/lib/Driver/ToolChains/SPIRV.h b/clang/lib/Driver/ToolChains/SPIRV.h index 924eb01adcbbf..018e9fa99607c 100644 --- a/clang/lib/Driver/ToolChains/SPIRV.h +++ b/clang/lib/Driver/ToolChains/SPIRV.h @@ -27,6 +27,11 @@ void constructAssembleCommand(Compilation &C, const Tool &T, const InputInfo &Input, const llvm::opt::ArgStringList &Args); +void constructLLVMLinkCommand(Compilation &C, const Tool &T, + const JobAction &JA, const InputInfo &Output, + const InputInfoList &Inputs, + const llvm::opt::ArgList &Args); + class LLVM_LIBRARY_VISIBILITY Translator : public Tool { public: Translator(const ToolChain &TC) diff --git a/clang/test/Driver/hipspv-link-static-library.hip b/clang/test/Driver/hipspv-link-static-library.hip index 03126ae589a09..cf16236738c12 100644 --- a/clang/test/Driver/hipspv-link-static-library.hip +++ b/clang/test/Driver/hipspv-link-static-library.hip @@ -22,7 +22,7 @@ // Verify that the input files are added before the SDL files in llvm-link command // This tests the ordering fix to match HIPAMD behavior // SDL-LINK: "{{.*}}clang-offload-bundler" "-unbundle" "-type=a" "-input={{.*}}libSDL.a" "-targets=hip-spirv64-unknown-unknown-unknown-generic" "-output=[[SDL_A:.*\.a]]" "-allow-missing-bundles" -// SDL-LINK: "{{.*}}llvm-link" "{{.*}}.bc" "[[SDL_A]]" "-o" +// SDL-LINK: "{{.*}}llvm-link" "-o" "{{.*}}.bc" "{{.*}}.bc" "[[SDL_A]]" // SDL-ARCHIVE: "{{.*}}clang-offload-bundler" "-unbundle" "-type=a" "-input={{.*}}libSDL.a" "-targets=hip-spirv64-unknown-unknown-unknown-generic" "-output=[[SDL_A:.*\.a]]" "-allow-missing-bundles" -// SDL-ARCHIVE: "{{.*}}llvm-link" "{{.*}}.bc" "[[SDL_A]]" "-o" +// SDL-ARCHIVE: "{{.*}}llvm-link" "-o" "{{.*}}.bc" "{{.*}}.bc" "[[SDL_A]]" diff --git a/clang/test/Driver/hipspv-toolchain-rdc.hip b/clang/test/Driver/hipspv-toolchain-rdc.hip index acdadacc49064..05d9079f8dc18 100644 --- a/clang/test/Driver/hipspv-toolchain-rdc.hip +++ b/clang/test/Driver/hipspv-toolchain-rdc.hip @@ -41,7 +41,7 @@ // CHECK-SAME: {{.*}} [[B_SRC]] // Link device code, lower it with HIPSPV passes and emit SPIR-V binary. -// CHECK: {{".*llvm-link.*"}} [[A_BC1]] [[B_BC1]] "-o" [[AB_LINK:".*bc"]] +// CHECK: {{".*llvm-link.*"}} "-o" [[AB_LINK:".*bc"]] [[A_BC1]] [[B_BC1]] // CHECK: {{".*opt.*"}} [[AB_LINK]] "-load-pass-plugin" // CHECK-SAME: "{{.*}}/Inputs/hipspv/lib/libLLVMHipSpvPasses.so" // CHECK-SAME: "-o" [[AB_LOWER:".*bc"]] diff --git a/clang/test/Driver/hipspv-toolchain.hip b/clang/test/Driver/hipspv-toolchain.hip index 3c175ebf433cc..85c4333e877f2 100644 --- a/clang/test/Driver/hipspv-toolchain.hip +++ b/clang/test/Driver/hipspv-toolchain.hip @@ -14,7 +14,7 @@ // CHECK-SAME: "-o" [[DEV_BC:".*bc"]] // CHECK-SAME: "-x" "hip" -// CHECK: {{".*llvm-link"}} [[DEV_BC]] "-o" [[LINK_BC:".*bc"]] +// CHECK: {{".*llvm-link"}} "-o" [[LINK_BC:".*bc"]] [[DEV_BC]] // CHECK: {{".*opt"}} [[LINK_BC]] "-load-pass-plugin" // CHECK-SAME: {{".*/hipspv/lib/libLLVMHipSpvPasses.so"}} diff --git a/clang/test/Driver/spirv-llvm-link-emit-asm.c b/clang/test/Driver/spirv-llvm-link-emit-asm.c new file mode 100644 index 0000000000000..86d3c1c9a6ba5 --- /dev/null +++ b/clang/test/Driver/spirv-llvm-link-emit-asm.c @@ -0,0 +1,31 @@ +// Check BC input with -S +// RUN: mkdir -p %t +// RUN: touch %t/a.bc +// RUN: touch %t/b.bc +// RUN: %clang -### --target=spirv64 -emit-llvm -S %t/a.bc %t/b.bc 2>&1 | FileCheck --check-prefix=CHECK-TOOL-BC %s + +// CHECK-TOOL-BC: "-cc1" {{.*}} "-o" "{{.*}}.ll" "-x" "ir" "{{.*}}.bc" +// CHECK-TOOL-BC: "-cc1" {{.*}} "-o" "{{.*}}.ll" "-x" "ir" "{{.*}}.bc" +// CHECK-TOOL-BC-NOT: llvm-link + +// RUN: %clang -ccc-print-bindings --target=spirv64 -emit-llvm -S %t/a.bc %t/b.bc 2>&1 | FileCheck -check-prefix=CHECK-BINDINGS-BC %s + +// CHECK-BINDINGS-BC: "spirv64" - "clang", inputs: ["{{.*}}.bc"], output: "[[TMP1_BINDINGS_BC:.+]]" +// CHECK-BINDINGS-BC: "spirv64" - "clang", inputs: ["{{.*}}.bc"], output: "[[TMP2_BINDINGS_BC:.+]]" +// CHECK-BINDINGS-BC-NOT: SPIR-V::Linker + +// Check source input with -S +// RUN: touch %t/foo.c +// RUN: touch %t/bar.c + +// RUN: %clang -### --target=spirv64 -emit-llvm -S %t/foo.c %t/bar.c 2>&1 | FileCheck --check-prefix=CHECK-TOOL-SRC %s + +// CHECK-TOOL-SRC: "-cc1" {{.*}} "-o" "{{.*}}.ll" "-x" "c" "{{.*}}foo.c" +// CHECK-TOOL-SRC: "-cc1" {{.*}} "-o" "{{.*}}.ll" "-x" "c" "{{.*}}bar.c" +// CHECK-TOOL-SRC-NOT: llvm-link + +// RUN: %clang -ccc-print-bindings --target=spirv64 -emit-llvm -S %t/foo.c %t/bar.c 2>&1 | FileCheck -check-prefix=CHECK-BINDINGS-SRC %s + +// CHECK-BINDINGS-SRC: "spirv64" - "clang", inputs: ["{{.*}}foo.c"], output: "{{.*}}.ll" +// CHECK-BINDINGS-SRC: "spirv64" - "clang", inputs: ["{{.*}}bar.c"], output: "{{.*}}.ll" +// CHECK-BINDINGS-SRC-NOT: SPIR-V::Linker diff --git a/clang/test/Driver/spirv-llvm-link.c b/clang/test/Driver/spirv-llvm-link.c new file mode 100644 index 0000000000000..b7598395b3fad --- /dev/null +++ b/clang/test/Driver/spirv-llvm-link.c @@ -0,0 +1,33 @@ +// Check BC input +// RUN: mkdir -p %t +// RUN: touch %t/a.bc +// RUN: touch %t/b.bc +// RUN: %clang -### --target=spirv64 -emit-llvm %t/a.bc %t/b.bc 2>&1 | FileCheck --check-prefix=CHECK-TOOL-BC %s + +// CHECK-TOOL-BC: "-cc1" {{.*}} "-o" "[[TMP1_BC:.+]]" "-x" "ir" "{{.*}}.bc" +// CHECK-TOOL-BC: "-cc1" {{.*}} "-o" "[[TMP2_BC:.+]]" "-x" "ir" "{{.*}}.bc" +// CHECK-TOOL-BC: llvm-link{{.*}} "-o" {{.*}} "[[TMP1_BC]]" "[[TMP2_BC]]" +// CHECK-TOOL-BC-NOT: llvm-link + +// RUN: %clang -ccc-print-bindings --target=spirv64 -emit-llvm %t/a.bc %t/b.bc 2>&1 | FileCheck -check-prefix=CHECK-BINDINGS-BC %s + +// CHECK-BINDINGS-BC: "spirv64" - "clang", inputs: ["{{.*}}.bc"], output: "[[TMP1_BINDINGS_BC:.+]]" +// CHECK-BINDINGS-BC: "spirv64" - "clang", inputs: ["{{.*}}.bc"], output: "[[TMP2_BINDINGS_BC:.+]]" +// CHECK-BINDINGS-BC: "spirv64" - "SPIR-V::Linker", inputs: ["[[TMP1_BINDINGS_BC]]", "[[TMP2_BINDINGS_BC]]"], output: "{{.*}}.bc" + +// Check source input +// RUN: touch %t/foo.c +// RUN: touch %t/bar.c + +// RUN: %clang -### --target=spirv64 -emit-llvm %t/foo.c %t/bar.c 2>&1 | FileCheck --check-prefix=CHECK-TOOL-SRC %s + +// CHECK-TOOL-SRC: "-cc1" {{.*}} "-o" "[[TMP1_SRC_BC:.+]]" "-x" "c" "{{.*}}foo.c" +// CHECK-TOOL-SRC: "-cc1" {{.*}} "-o" "[[TMP2_SRC_BC:.+]]" "-x" "c" "{{.*}}bar.c" +// CHECK-TOOL-SRC: llvm-link{{.*}} "-o" {{.*}} "[[TMP1_SRC_BC]]" "[[TMP2_SRC_BC]]" +// CHECK-TOOL-SRC-NOT: llvm-link + +// RUN: %clang -ccc-print-bindings --target=spirv64 -emit-llvm %t/foo.c %t/bar.c 2>&1 | FileCheck -check-prefix=CHECK-BINDINGS-SRC %s + +// CHECK-BINDINGS-SRC: "spirv64" - "clang", inputs: ["{{.*}}foo.c"], output: "[[TMP1_BINDINGS_SRC_BC:.+]]" +// CHECK-BINDINGS-SRC: "spirv64" - "clang", inputs: ["{{.*}}bar.c"], output: "[[TMP2_BINDINGS_SRC_BC:.+]]" +// CHECK-BINDINGS-SRC: "spirv64" - "SPIR-V::Linker", inputs: ["[[TMP1_BINDINGS_SRC_BC]]", "[[TMP2_BINDINGS_SRC_BC]]"], output: "{{.*}}.bc" _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
