Author: Deric C. Date: 2025-07-24T13:54:00-07:00 New Revision: ed9a1027a482d18b3cf063e8bcc6e31a4c7dc024
URL: https://github.com/llvm/llvm-project/commit/ed9a1027a482d18b3cf063e8bcc6e31a4c7dc024 DIFF: https://github.com/llvm/llvm-project/commit/ed9a1027a482d18b3cf063e8bcc6e31a4c7dc024.diff LOG: [HLSL] Avoid putting the byval attribute on out and inout parameters (#150495) Fixes #148063 by preventing the ByVal attribute from being placed on out and inout function parameters which causes them to be eliminated by the Dead Store Elimination (DSE) pass. Added: Modified: clang/lib/CodeGen/CGCall.cpp clang/test/CodeGenHLSL/BasicFeatures/ArrayOutputArguments.hlsl Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp index 0bceecec6e555..d9bd443455e0f 100644 --- a/clang/lib/CodeGen/CGCall.cpp +++ b/clang/lib/CodeGen/CGCall.cpp @@ -2852,20 +2852,28 @@ void CodeGenModule::ConstructAttributeList(StringRef Name, if (AI.getInReg()) Attrs.addAttribute(llvm::Attribute::InReg); - // Depending on the ABI, this may be either a byval or a dead_on_return - // argument. - if (AI.getIndirectByVal()) { - Attrs.addByValAttr(getTypes().ConvertTypeForMem(ParamType)); - } else { - // Add dead_on_return when the object's lifetime ends in the callee. - // This includes trivially-destructible objects, as well as objects - // whose destruction / clean-up is carried out within the callee (e.g., - // Obj-C ARC-managed structs, MSVC callee-destroyed objects). - if (!ParamType.isDestructedType() || !ParamType->isRecordType() || - ParamType->castAs<RecordType>() - ->getDecl() - ->isParamDestroyedInCallee()) - Attrs.addAttribute(llvm::Attribute::DeadOnReturn); + // HLSL out and inout parameters must not be marked with ByVal or + // DeadOnReturn attributes because stores to these parameters by the + // callee are visible to the caller. + if (auto ParamABI = FI.getExtParameterInfo(ArgNo).getABI(); + ParamABI != ParameterABI::HLSLOut && + ParamABI != ParameterABI::HLSLInOut) { + + // Depending on the ABI, this may be either a byval or a dead_on_return + // argument. + if (AI.getIndirectByVal()) { + Attrs.addByValAttr(getTypes().ConvertTypeForMem(ParamType)); + } else { + // Add dead_on_return when the object's lifetime ends in the callee. + // This includes trivially-destructible objects, as well as objects + // whose destruction / clean-up is carried out within the callee + // (e.g., Obj-C ARC-managed structs, MSVC callee-destroyed objects). + if (!ParamType.isDestructedType() || !ParamType->isRecordType() || + ParamType->castAs<RecordType>() + ->getDecl() + ->isParamDestroyedInCallee()) + Attrs.addAttribute(llvm::Attribute::DeadOnReturn); + } } auto *Decl = ParamType->getAsRecordDecl(); diff --git a/clang/test/CodeGenHLSL/BasicFeatures/ArrayOutputArguments.hlsl b/clang/test/CodeGenHLSL/BasicFeatures/ArrayOutputArguments.hlsl index bccfaf597f0ed..4571649717d8a 100644 --- a/clang/test/CodeGenHLSL/BasicFeatures/ArrayOutputArguments.hlsl +++ b/clang/test/CodeGenHLSL/BasicFeatures/ArrayOutputArguments.hlsl @@ -11,7 +11,7 @@ void increment(inout int Arr[2]) { // CHECK-NEXT: [[Tmp:%.*]] = alloca [2 x i32], align 4 // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 @{{.*}}, i32 8, i1 false) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Tmp]], ptr align 4 [[A]], i32 8, i1 false) -// CHECK-NEXT: call void @{{.*}}increment{{.*}}(ptr noalias noundef byval([2 x i32]) align 4 [[Tmp]]) +// CHECK-NEXT: call void @{{.*}}increment{{.*}}(ptr noalias noundef align 4 [[Tmp]]) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 [[Tmp]], i32 8, i1 false) // CHECK-NEXT: [[Idx:%.*]] = getelementptr inbounds [2 x i32], ptr [[A]], i32 0, i32 0 // CHECK-NEXT: [[B:%.*]] = load i32, ptr [[Idx]], align 4 @@ -32,7 +32,7 @@ void fn2(out int Arr[2]) { // CHECK: [[A:%.*]] = alloca [2 x i32], align 4 // CHECK-NEXT: [[Tmp:%.*]] = alloca [2 x i32], align 4 // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 @{{.*}}, i32 8, i1 false) -// CHECK-NEXT: call void @{{.*}}fn2{{.*}}(ptr noalias noundef byval([2 x i32]) align 4 [[Tmp]]) +// CHECK-NEXT: call void @{{.*}}fn2{{.*}}(ptr noalias noundef align 4 [[Tmp]]) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 [[Tmp]], i32 8, i1 false) // CHECK-NEXT: [[Idx:%.*]] = getelementptr inbounds [2 x i32], ptr [[A]], i32 0, i32 0 // CHECK-NEXT: [[B:%.*]] = load i32, ptr [[Idx]], align 4 @@ -56,7 +56,7 @@ void nestedCall(inout int Arr[2], uint index) { // CHECK-NEXT: [[Tmp:%.*]] = alloca [2 x i32], align 4 // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 @{{.*}}, i32 8, i1 false) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Tmp]], ptr align 4 [[A]], i32 8, i1 false) -// CHECK-NEXT: call void @{{.*}}nestedCall{{.*}}(ptr noalias noundef byval([2 x i32]) align 4 [[Tmp]], i32 noundef 0) +// CHECK-NEXT: call void @{{.*}}nestedCall{{.*}}(ptr noalias noundef align 4 [[Tmp]], i32 noundef 0) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 [[Tmp]], i32 8, i1 false) // CHECK-NEXT: [[Idx:%.*]] = getelementptr inbounds [2 x i32], ptr [[A]], i32 0, i32 1 // CHECK-NEXT: [[B:%.*]] = load i32, ptr [[Idx]], align 4 @@ -70,7 +70,7 @@ export int arrayCall3() { // CHECK-LABEL: outerCall // CHECK: [[Tmp:%.*]] = alloca [2 x i32], align 4 // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Tmp]], ptr align 4 %{{.*}}, i32 8, i1 false) -// CHECK-NEXT: call void {{.*}}increment{{.*}}(ptr noalias noundef byval([2 x i32]) align 4 [[Tmp]]) +// CHECK-NEXT: call void {{.*}}increment{{.*}}(ptr noalias noundef align 4 [[Tmp]]) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 {{.*}}, ptr align 4 [[Tmp]], i32 8, i1 false) // CHECK-NEXT: ret void void outerCall(inout int Arr[2]) { @@ -82,7 +82,7 @@ void outerCall(inout int Arr[2]) { // CHECK-NEXT: [[Tmp:%.*]] = alloca [2 x i32], align 4 // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 @{{.*}}, i32 8, i1 false) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Tmp]], ptr align 4 [[A]], i32 8, i1 false) -// CHECK-NEXT: call void @{{.*}}outerCall{{.*}}(ptr noalias noundef byval([2 x i32]) align 4 [[Tmp]]) +// CHECK-NEXT: call void @{{.*}}outerCall{{.*}}(ptr noalias noundef align 4 [[Tmp]]) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 [[Tmp]], i32 8, i1 false) // CHECK-NEXT: [[Idx:%.*]] = getelementptr inbounds [2 x i32], ptr [[A]], i32 0, i32 0 // CHECK-NEXT: [[B:%.*]] = load i32, ptr [[Idx]], align 4 @@ -110,7 +110,7 @@ void outerCall2(inout int Arr[2]) { // CHECK-NEXT: [[Tmp:%.*]] = alloca [2 x i32], align 4 // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 @{{.*}}, i32 8, i1 false) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Tmp]], ptr align 4 [[A]], i32 8, i1 false) -// CHECK-NEXT: call void @{{.*}}outerCall2{{.*}}(ptr noalias noundef byval([2 x i32]) align 4 [[Tmp]]) +// CHECK-NEXT: call void @{{.*}}outerCall2{{.*}}(ptr noalias noundef align 4 [[Tmp]]) // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[A]], ptr align 4 [[Tmp]], i32 8, i1 false) // CHECK-NEXT: [[Idx:%.*]] = getelementptr inbounds [2 x i32], ptr [[A]], i32 0, i32 0 // CHECK-NEXT: [[B:%.*]] = load i32, ptr [[Idx]], align 4 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
