Author: Deric C. Date: 2026-03-23T14:49:53-07:00 New Revision: bcfe1e94d3f062139aae009e44ae458f69cf2df2
URL: https://github.com/llvm/llvm-project/commit/bcfe1e94d3f062139aae009e44ae458f69cf2df2 DIFF: https://github.com/llvm/llvm-project/commit/bcfe1e94d3f062139aae009e44ae458f69cf2df2.diff LOG: [HLSL] Allow 1x1 matrices to be splatted like scalars (#188119) Fixes #186859 by allowing 1x1 matrices to be splatted like the scalar and vec1 cases. Assisted-by: GitHub Copilot (powered by Claude Opus 4.6) Added: Modified: clang/lib/Sema/SemaCast.cpp clang/lib/Sema/SemaHLSL.cpp clang/test/CodeGenHLSL/BasicFeatures/AggregateSplatCast.hlsl Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaCast.cpp b/clang/lib/Sema/SemaCast.cpp index 5360f8a2908bf..330e5ec699790 100644 --- a/clang/lib/Sema/SemaCast.cpp +++ b/clang/lib/Sema/SemaCast.cpp @@ -2939,11 +2939,17 @@ bool CastOperation::CheckHLSLCStyleCast(CheckedConversionKind CCK) { if (Self.HLSL().CanPerformAggregateSplatCast(SrcExpr.get(), DestType)) { SrcExpr = Self.DefaultLvalueConversion(SrcExpr.get()); const VectorType *VT = SrcTy->getAs<VectorType>(); + const ConstantMatrixType *MT = SrcTy->getAs<ConstantMatrixType>(); // change splat from vec1 case to splat from scalar if (VT && VT->getNumElements() == 1) SrcExpr = Self.ImpCastExprToType( SrcExpr.get(), VT->getElementType(), CK_HLSLVectorTruncation, SrcExpr.get()->getValueKind(), nullptr, CCK); + // change splat from 1x1 matrix case to splat from scalar + else if (MT && MT->getNumElementsFlattened() == 1) + SrcExpr = Self.ImpCastExprToType( + SrcExpr.get(), MT->getElementType(), CK_HLSLMatrixTruncation, + SrcExpr.get()->getValueKind(), nullptr, CCK); // Inserting a scalar cast here allows for a simplified codegen in // the case the destTy is a vector if (const VectorType *DVT = DestType->getAs<VectorType>()) diff --git a/clang/lib/Sema/SemaHLSL.cpp b/clang/lib/Sema/SemaHLSL.cpp index e2f2d6cb75c33..823d312df296e 100644 --- a/clang/lib/Sema/SemaHLSL.cpp +++ b/clang/lib/Sema/SemaHLSL.cpp @@ -4644,8 +4644,8 @@ bool SemaHLSL::CanPerformScalarCast(QualType SrcTy, QualType DestTy) { } // Can perform an HLSL Aggregate splat cast if the Dest is an aggregate and the -// Src is a scalar or a vector of length 1 -// Or if Dest is a vector and Src is a vector of length 1 +// Src is a scalar, a vector of length 1, or a 1x1 matrix +// Or if Dest is a vector and Src is a vector of length 1 or a 1x1 matrix bool SemaHLSL::CanPerformAggregateSplatCast(Expr *Src, QualType DestTy) { QualType SrcTy = Src->getType(); @@ -4656,13 +4656,18 @@ bool SemaHLSL::CanPerformAggregateSplatCast(Expr *Src, QualType DestTy) { return false; const VectorType *SrcVecTy = SrcTy->getAs<VectorType>(); + const ConstantMatrixType *SrcMatTy = SrcTy->getAs<ConstantMatrixType>(); - // Src isn't a scalar or a vector of length 1 - if (!SrcTy->isScalarType() && !(SrcVecTy && SrcVecTy->getNumElements() == 1)) + // Src isn't a scalar, a vector of length 1, or a 1x1 matrix + if (!SrcTy->isScalarType() && + !(SrcVecTy && SrcVecTy->getNumElements() == 1) && + !(SrcMatTy && SrcMatTy->getNumElementsFlattened() == 1)) return false; if (SrcVecTy) SrcTy = SrcVecTy->getElementType(); + else if (SrcMatTy) + SrcTy = SrcMatTy->getElementType(); llvm::SmallVector<QualType> DestTypes; BuildFlattenedTypeList(DestTy, DestTypes); diff --git a/clang/test/CodeGenHLSL/BasicFeatures/AggregateSplatCast.hlsl b/clang/test/CodeGenHLSL/BasicFeatures/AggregateSplatCast.hlsl index 4e6c7537bcaa4..abfea79f0a454 100644 --- a/clang/test/CodeGenHLSL/BasicFeatures/AggregateSplatCast.hlsl +++ b/clang/test/CodeGenHLSL/BasicFeatures/AggregateSplatCast.hlsl @@ -84,6 +84,39 @@ export void call5() { S s = (S)A; } +// vector splat from 1x1 matrix +// CHECK-LABEL: define void {{.*}}call9 +// CHECK: [[M:%.*]] = alloca [1 x <1 x float>], align 4 +// CHECK-NEXT: [[A:%.*]] = alloca <4 x i32>, align 4 +// CHECK-NEXT: store <1 x float> {{.*}}, ptr [[M]], align 4 +// CHECK-NEXT: [[L:%.*]] = load <1 x float>, ptr [[M]], align 4 +// CHECK-NEXT: [[ML:%.*]] = extractelement <1 x float> [[L]], i32 0 +// CHECK-NEXT: [[C:%.*]] = fptosi float [[ML]] to i32 +// CHECK-NEXT: [[SI:%.*]] = insertelement <4 x i32> poison, i32 [[C]], i64 0 +// CHECK-NEXT: [[S:%.*]] = shufflevector <4 x i32> [[SI]], <4 x i32> poison, <4 x i32> zeroinitializer +// CHECK-NEXT: store <4 x i32> [[S]], ptr [[A]], align 4 +export void call9() { + float1x1 M = {1.0}; + int4 A = (int4)M; +} + +// struct splat from 1x1 matrix +// CHECK-LABEL: define void {{.*}}call10 +// CHECK: [[M:%.*]] = alloca [1 x <1 x i32>], align 4 +// CHECK-NEXT: [[s:%.*]] = alloca %struct.S, align 1 +// CHECK-NEXT: store <1 x i32> splat (i32 1), ptr [[M]], align 4 +// CHECK-NEXT: [[L:%.*]] = load <1 x i32>, ptr [[M]], align 4 +// CHECK-NEXT: [[ML:%.*]] = extractelement <1 x i32> [[L]], i32 0 +// CHECK-NEXT: [[G1:%.*]] = getelementptr inbounds %struct.S, ptr [[s]], i32 0, i32 0 +// CHECK-NEXT: [[G2:%.*]] = getelementptr inbounds %struct.S, ptr [[s]], i32 0, i32 1 +// CHECK-NEXT: store i32 [[ML]], ptr [[G1]], align 4 +// CHECK-NEXT: [[C:%.*]] = sitofp i32 [[ML]] to float +// CHECK-NEXT: store float [[C]], ptr [[G2]], align 4 +export void call10() { + int1x1 M = {1}; + S s = (S)M; +} + struct BFields { double DF; int E: 15; _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
