Author: Deric C. Date: 2025-04-09T18:14:23-07:00 New Revision: 747d4a952bf7ed4adec72ddf3c9038aeff4fe8ee
URL: https://github.com/llvm/llvm-project/commit/747d4a952bf7ed4adec72ddf3c9038aeff4fe8ee DIFF: https://github.com/llvm/llvm-project/commit/747d4a952bf7ed4adec72ddf3c9038aeff4fe8ee.diff LOG: [DirectX] Implement UseNativeLowPrecision shader flag analysis (#134288) Fixes #112267 Implement the shader flag analysis to set the UseNativeLowPrecision DXIL module flag. The flag is only able to be set when the command-line flag `-enable-16bit-types` is passed to clang-dxc, or equivalently `-fnative-half-type` is passed to clang. When the command-line flag is passed, a module metadata flag called "dx.nativelowprec" is set to 1. The DXILShaderFlags shader flags analysis checks that the module metadata flag "dx.nativelowprec" is set to 1 and the DXIL Version is 1.2 or greater before setting the UseNativeLowPrecision DXIL module flag. Added: clang/test/CodeGenHLSL/enable-16bit-types.hlsl llvm/test/CodeGen/DirectX/ShaderFlags/use-native-low-precision.ll Modified: clang/lib/CodeGen/CGHLSLRuntime.cpp llvm/lib/Target/DirectX/DXILShaderFlags.cpp llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp index 3b1810b62a2cd..77700ea3a676d 100644 --- a/clang/lib/CodeGen/CGHLSLRuntime.cpp +++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp @@ -282,11 +282,19 @@ void CGHLSLRuntime::addHLSLBufferLayoutType(const RecordType *StructType, void CGHLSLRuntime::finishCodeGen() { auto &TargetOpts = CGM.getTarget().getTargetOpts(); + auto &LangOpts = CGM.getLangOpts(); llvm::Module &M = CGM.getModule(); Triple T(M.getTargetTriple()); if (T.getArch() == Triple::ArchType::dxil) addDxilValVersion(TargetOpts.DxilValidatorVersion, M); + // NativeHalfType corresponds to the -fnative-half-type clang option which is + // aliased by clang-dxc's -enable-16bit-types option. This option is used to + // set the UseNativeLowPrecision DXIL module flag in the DirectX backend + if (LangOpts.NativeHalfType) + M.setModuleFlag(llvm::Module::ModFlagBehavior::Error, "dx.nativelowprec", + 1); + generateGlobalCtorDtorCalls(); } diff --git a/clang/test/CodeGenHLSL/enable-16bit-types.hlsl b/clang/test/CodeGenHLSL/enable-16bit-types.hlsl new file mode 100644 index 0000000000000..9b5c742f9dacd --- /dev/null +++ b/clang/test/CodeGenHLSL/enable-16bit-types.hlsl @@ -0,0 +1,7 @@ +// RUN: %clang_dxc -enable-16bit-types -T lib_6_3 -HV 202x -Vd -Xclang -emit-llvm %s | FileCheck %s --check-prefix=FLAG +// RUN: %clang_dxc -T lib_6_3 -HV 202x -Vd -Xclang -emit-llvm %s | FileCheck %s --check-prefix=NOFLAG + +// FLAG-DAG: ![[NLP:.*]] = !{i32 1, !"dx.nativelowprec", i32 1} +// FLAG-DAG: !llvm.module.flags = !{{{.*}}![[NLP]]{{.*}}} + +// NOFLAG-NOT: dx.nativelowprec diff --git a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp index babf495220393..2ca428672e1c4 100644 --- a/llvm/lib/Target/DirectX/DXILShaderFlags.cpp +++ b/llvm/lib/Target/DirectX/DXILShaderFlags.cpp @@ -188,6 +188,13 @@ void ModuleShaderFlags::initialize(Module &M, DXILResourceTypeMap &DRTM, continue; } + // Set UseNativeLowPrecision using dx.nativelowprec module metadata + if (auto *NativeLowPrec = mdconst::extract_or_null<ConstantInt>( + M.getModuleFlag("dx.nativelowprec"))) + if (MMDI.DXILVersion >= VersionTuple(1, 2) && + NativeLowPrec->getValue() != 0) + SCCSF.UseNativeLowPrecision = true; + ComputedShaderFlags CSF; for (const auto &BB : *F) for (const auto &I : BB) diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll index fd25a165bfe8d..52e00b107bb82 100644 --- a/llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll +++ b/llvm/test/CodeGen/DirectX/ShaderFlags/low-precision.ll @@ -1,5 +1,4 @@ ; RUN: opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s -; RUN: llc %s --filetype=obj -o - | obj2yaml | FileCheck %s --check-prefix=DXC target triple = "dxil-pc-shadermodel6.7-library" @@ -13,26 +12,19 @@ target triple = "dxil-pc-shadermodel6.7-library" ;CHECK-NEXT: ; Shader Flags for Module Functions ;CHECK-LABEL: ; Function add_i16 : 0x00000020 -define i16 @add_i16(i16 %a, i16 %b) #0 { +define i16 @add_i16(i16 %a, i16 %b) { %sum = add i16 %a, %b ret i16 %sum } ;CHECK-LABEL: ; Function add_i32 : 0x00000000 -define i32 @add_i32(i32 %a, i32 %b) #0 { +define i32 @add_i32(i32 %a, i32 %b) { %sum = add i32 %a, %b ret i32 %sum } ;CHECK-LABEL: ; Function add_half : 0x00000020 -define half @add_half(half %a, half %b) #0 { +define half @add_half(half %a, half %b) { %sum = fadd half %a, %b ret half %sum } - -attributes #0 = { convergent norecurse nounwind "hlsl.export"} - -; DXC: - Name: SFI0 -; DXC-NEXT: Size: 8 -; DXC-NOT: Flags: -; DXC: ... diff --git a/llvm/test/CodeGen/DirectX/ShaderFlags/use-native-low-precision.ll b/llvm/test/CodeGen/DirectX/ShaderFlags/use-native-low-precision.ll new file mode 100644 index 0000000000000..98e9a5fa7b241 --- /dev/null +++ b/llvm/test/CodeGen/DirectX/ShaderFlags/use-native-low-precision.ll @@ -0,0 +1,37 @@ +; RUN: opt -S --passes="print-dx-shader-flags" 2>&1 %s | FileCheck %s + +target triple = "dxil-pc-shadermodel6.7-library" + +;CHECK: ; Combined Shader Flags for Module +;CHECK-NEXT: ; Shader Flags Value: 0x00800020 +;CHECK-NEXT: ; +;CHECK-NEXT: ; Note: shader requires additional functionality: +;CHECK-NEXT: ; Note: extra DXIL module flags: +;CHECK-NEXT: ; D3D11_1_SB_GLOBAL_FLAG_ENABLE_MINIMUM_PRECISION +;CHECK-NEXT: ; Native 16bit types enabled +;CHECK-NEXT: ; +;CHECK-NEXT: ; Shader Flags for Module Functions + +;CHECK-LABEL: ; Function add_i16 : 0x00800020 +define i16 @add_i16(i16 %a, i16 %b) { + %sum = add i16 %a, %b + ret i16 %sum +} + +; NOTE: The flag for native low precision (0x80000) is set for every function +; in the module regardless of whether or not the function uses low precision +; data types (flag 0x20). This matches the behavior in DXC +;CHECK-LABEL: ; Function add_i32 : 0x00800000 +define i32 @add_i32(i32 %a, i32 %b) { + %sum = add i32 %a, %b + ret i32 %sum +} + +;CHECK-LABEL: ; Function add_half : 0x00800020 +define half @add_half(half %a, half %b) { + %sum = fadd half %a, %b + ret half %sum +} + +!llvm.module.flags = !{!0} +!0 = !{i32 1, !"dx.nativelowprec", i32 1} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
