llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-backend-amdgpu Author: Alex Voicu (AlexVlx) <details> <summary>Changes</summary> 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. --- Full diff: https://github.com/llvm/llvm-project/pull/154765.diff 4 Files Affected: - (modified) clang/lib/Driver/ToolChains/AMDGPU.cpp (+7) - (modified) clang/lib/Driver/ToolChains/HIPAMD.cpp (+6) - (modified) clang/test/Driver/hip-toolchain-no-rdc.hip (+1-1) - (modified) clang/test/Driver/spirv-amd-toolchain.c (+1-1) ``````````diff diff --git a/clang/lib/Driver/ToolChains/AMDGPU.cpp b/clang/lib/Driver/ToolChains/AMDGPU.cpp index 5e463b9c98687..bad1bd694b9e7 100644 --- a/clang/lib/Driver/ToolChains/AMDGPU.cpp +++ b/clang/lib/Driver/ToolChains/AMDGPU.cpp @@ -858,6 +858,13 @@ 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. + if (getTriple().isSPIRV() && + !DriverArgs.hasArg(options::OPT_disable_llvm_passes)) + CC1Args.push_back("-disable-llvm-passes"); + 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..0c8ccd1d17487 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-passes" {{.*}} "-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" `````````` </details> https://github.com/llvm/llvm-project/pull/154765 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
