Author: Alex Voicu Date: 2025-09-18T12:38:05+01:00 New Revision: e6c27b37d7ed9a00e33ab0ec84f0160617da5cfc
URL: https://github.com/llvm/llvm-project/commit/e6c27b37d7ed9a00e33ab0ec84f0160617da5cfc DIFF: https://github.com/llvm/llvm-project/commit/e6c27b37d7ed9a00e33ab0ec84f0160617da5cfc.diff LOG: [Driver][AMDGPU][HIP][SPIRV] Disable optimizations for AMDGCN SPIR-V (#154765) SPIR-V specific optimizations can inadvertently remove information that is important for the AMDGPU BE / break certain code patterns we rely on. Therefore, for AMDGCN flavoured SPIR-V we disable optimizations over IR, to ensure that we operate directly on the output of Clang CodeGen when we finalise. Added: Modified: clang/lib/Driver/ToolChains/AMDGPU.cpp clang/lib/Driver/ToolChains/HIPAMD.cpp clang/test/Driver/hip-toolchain-no-rdc.hip clang/test/Driver/spirv-amd-toolchain.c Removed: ################################################################################ diff --git a/clang/lib/Driver/ToolChains/AMDGPU.cpp b/clang/lib/Driver/ToolChains/AMDGPU.cpp index 5e463b9c98687..ae546e9767039 100644 --- a/clang/lib/Driver/ToolChains/AMDGPU.cpp +++ b/clang/lib/Driver/ToolChains/AMDGPU.cpp @@ -858,6 +858,20 @@ void AMDGPUToolChain::addClangTargetOptions( CC1Args.push_back("-fapply-global-visibility-to-externs"); } + // For SPIR-V we want to retain the pristine output of Clang CodeGen, since + // optimizations might lose structure / information that is necessary for + // generating optimal concrete AMDGPU code. + // TODO: using the below option is a temporary placeholder until Clang + // provides the required functionality, which essentially boils down to + // -O0 being refactored / reworked to not imply optnone / remove TBAA. + // Once that is added, we should pivot to that functionality, being + // mindful to not corrupt the user provided and subsequently embedded + // command-line (i.e. if the user asks for -O3 this is what the + // finalisation should use). + if (getTriple().isSPIRV() && + !DriverArgs.hasArg(options::OPT_disable_llvm_optzns)) + CC1Args.push_back("-disable-llvm-optzns"); + if (DeviceOffloadingKind == Action::OFK_None) addOpenCLBuiltinsLib(getDriver(), DriverArgs, CC1Args); } diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp index b4c6da0d73d13..5f3fbea40f162 100644 --- a/clang/lib/Driver/ToolChains/HIPAMD.cpp +++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp @@ -261,6 +261,12 @@ void HIPAMDToolChain::addClangTargetOptions( // with options that match the user-supplied ones. if (!DriverArgs.hasArg(options::OPT_fembed_bitcode_marker)) CC1Args.push_back("-fembed-bitcode=marker"); + // For SPIR-V we want to retain the pristine output of Clang CodeGen, since + // optimizations might lose structure / information that is necessary for + // generating optimal concrete AMDGPU code. We duplicate this because the + // HIP TC doesn't invoke the base AMDGPU TC addClangTargetOptions. + if (!DriverArgs.hasArg(options::OPT_disable_llvm_passes)) + CC1Args.push_back("-disable-llvm-passes"); return; // No DeviceLibs for SPIR-V. } diff --git a/clang/test/Driver/hip-toolchain-no-rdc.hip b/clang/test/Driver/hip-toolchain-no-rdc.hip index ddd251b67cc57..dc8f0a97ad371 100644 --- a/clang/test/Driver/hip-toolchain-no-rdc.hip +++ b/clang/test/Driver/hip-toolchain-no-rdc.hip @@ -206,7 +206,7 @@ // Check mixed AMDGCNSPIRV and concrete GPU arch. // -// AMDGCNSPIRV: "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}}"-emit-llvm-bc" {{.*}} "-o" "[[AMDGCNSPV_BC:.*bc]]" +// AMDGCNSPIRV: "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}}"-emit-llvm-bc" {{.*}}"-fembed-bitcode=marker" "-disable-llvm-passes" {{.*}} "-o" "[[AMDGCNSPV_BC:.*bc]]" // AMDGCNSPIRV: {{".*llvm-link.*"}} "-o" "[[AMDGCNSPV_TMP:.*out]]" "[[AMDGCNSPV_BC]]" // AMDGCNSPIRV: {{".*llvm-spirv.*"}} "--spirv-max-version=1.6" "--spirv-ext=+all" {{.*}} "[[AMDGCNSPV_TMP]]" {{.*}}"-o" "[[AMDGCNSPV_CO:.*out]]" // AMDGCNSPIRV: "-cc1" "-triple" "amdgcn-amd-amdhsa" {{.*}}"-emit-obj" {{.*}}"-target-cpu" "gfx900"{{.*}} "-o" "[[GFX900_OBJ:.*o]]" diff --git a/clang/test/Driver/spirv-amd-toolchain.c b/clang/test/Driver/spirv-amd-toolchain.c index c9417400a9378..14ba8f4632477 100644 --- a/clang/test/Driver/spirv-amd-toolchain.c +++ b/clang/test/Driver/spirv-amd-toolchain.c @@ -14,6 +14,6 @@ // RUN: %clang -### --target=spirv64-amd-amdhsa %s -nogpulib -nogpuinc 2>&1 \ // RUN: | FileCheck %s --check-prefix=INVOCATION -// INVOCATION: "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}} "-o" "[[OUTPUT:.+]]" "-x" "c" +// INVOCATION: "-cc1" "-triple" "spirv64-amd-amdhsa" {{.*}}"-disable-llvm-optzns" {{.*}} "-o" "[[OUTPUT:.+]]" "-x" "c" // INVOCATION: "{{.*}}llvm-link" "-o" "a.out" "[[OUTPUT]]" // INVOCATION: "{{.*}}llvm-spirv" "--spirv-max-version=1.6" "--spirv-ext=+all" "--spirv-allow-unknown-intrinsics" "--spirv-lower-const-expr" "--spirv-preserve-auxdata" "--spirv-debug-info-version=nonsemantic-shader-200" "a.out" "-o" "a.out" _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
