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[HLSL] Fix codegen to support classes in cbuffer #132828

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Merged
merged 1 commit into from
Mar 31, 2025
Merged

[HLSL] Fix codegen to support classes in cbuffer #132828

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26 changes: 13 additions & 13 deletions clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -52,11 +52,11 @@ static unsigned getScalarOrVectorSizeInBytes(llvm::Type *Ty) {
namespace clang {
namespace CodeGen {

// Creates a layout type for given struct with HLSL constant buffer layout
// taking into account PackOffsets, if provided.
// Creates a layout type for given struct or class with HLSL constant buffer
// layout taking into account PackOffsets, if provided.
// Previously created layout types are cached by CGHLSLRuntime.
//
// The function iterates over all fields of the StructType (including base
// The function iterates over all fields of the record type (including base
// classes) and calls layoutField to converts each field to its corresponding
// LLVM type and to calculate its HLSL constant buffer layout. Any embedded
// structs (or arrays of structs) are converted to target layout types as well.
Expand All @@ -67,12 +67,11 @@ namespace CodeGen {
// -1 value instead. These elements must be placed at the end of the layout
// after all of the elements with specific offset.
llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(
const RecordType *StructType,
const llvm::SmallVector<int32_t> *PackOffsets) {
const RecordType *RT, const llvm::SmallVector<int32_t> *PackOffsets) {

// check if we already have the layout type for this struct
if (llvm::TargetExtType *Ty =
CGM.getHLSLRuntime().getHLSLBufferLayoutType(StructType))
CGM.getHLSLRuntime().getHLSLBufferLayoutType(RT))
return Ty;

SmallVector<unsigned> Layout;
Expand All @@ -87,7 +86,7 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(

// iterate over all fields of the record, including fields on base classes
llvm::SmallVector<const RecordType *> RecordTypes;
RecordTypes.push_back(StructType);
RecordTypes.push_back(RT);
while (RecordTypes.back()->getAsCXXRecordDecl()->getNumBases()) {
CXXRecordDecl *D = RecordTypes.back()->getAsCXXRecordDecl();
assert(D->getNumBases() == 1 &&
Expand Down Expand Up @@ -148,7 +147,7 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(

// create the layout struct type; anonymous struct have empty name but
// non-empty qualified name
const CXXRecordDecl *Decl = StructType->getAsCXXRecordDecl();
const CXXRecordDecl *Decl = RT->getAsCXXRecordDecl();
std::string Name =
Decl->getName().empty() ? "anon" : Decl->getQualifiedNameAsString();
llvm::StructType *StructTy =
Expand All @@ -158,7 +157,7 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(
llvm::TargetExtType *NewLayoutTy = llvm::TargetExtType::get(
CGM.getLLVMContext(), LayoutTypeName, {StructTy}, Layout);
if (NewLayoutTy)
CGM.getHLSLRuntime().addHLSLBufferLayoutType(StructType, NewLayoutTy);
CGM.getHLSLRuntime().addHLSLBufferLayoutType(RT, NewLayoutTy);
return NewLayoutTy;
}

Expand Down Expand Up @@ -202,9 +201,9 @@ bool HLSLBufferLayoutBuilder::layoutField(const FieldDecl *FD,
}
// For array of structures, create a new array with a layout type
// instead of the structure type.
if (Ty->isStructureType()) {
if (Ty->isStructureOrClassType()) {
llvm::Type *NewTy =
cast<llvm::TargetExtType>(createLayoutType(Ty->getAsStructureType()));
cast<llvm::TargetExtType>(createLayoutType(Ty->getAs<RecordType>()));
if (!NewTy)
return false;
assert(isa<llvm::TargetExtType>(NewTy) && "expected target type");
Expand All @@ -220,9 +219,10 @@ bool HLSLBufferLayoutBuilder::layoutField(const FieldDecl *FD,
ArrayStride = llvm::alignTo(ElemSize, CBufferRowSizeInBytes);
ElemOffset = (Packoffset != -1) ? Packoffset : NextRowOffset;

} else if (FieldTy->isStructureType()) {
} else if (FieldTy->isStructureOrClassType()) {
// Create a layout type for the structure
ElemLayoutTy = createLayoutType(FieldTy->getAsStructureType());
ElemLayoutTy =
createLayoutType(cast<RecordType>(FieldTy->getAs<RecordType>()));
if (!ElemLayoutTy)
return false;
assert(isa<llvm::TargetExtType>(ElemLayoutTy) && "expected target type");
Expand Down
41 changes: 38 additions & 3 deletions clang/test/CodeGenHLSL/cbuffer.hlsl
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,12 @@
// CHECK: %C = type <{ i32, target("dx.Layout", %A, 8, 0) }>
// CHECK: %__cblayout_D = type <{ [2 x [3 x target("dx.Layout", %B, 14, 0, 8)]] }>

// CHECK: %__cblayout_CBClasses = type <{ target("dx.Layout", %K, 4, 0), target("dx.Layout", %L, 8, 0, 4),
// CHECK-SAME: target("dx.Layout", %M, 68, 0), [10 x target("dx.Layout", %K, 4, 0)] }>
// CHECK: %K = type <{ float }>
// CHECK: %L = type <{ float, float }>
// CHECK: %M = type <{ [5 x target("dx.Layout", %K, 4, 0)] }>

// CHECK: %__cblayout_CBMix = type <{ [2 x target("dx.Layout", %Test, 8, 0, 4)], float, [3 x [2 x <2 x float>]], float,
// CHECK-SAME: target("dx.Layout", %anon, 4, 0), double, target("dx.Layout", %anon.0, 8, 0), float, <1 x double>, i16 }>

Expand Down Expand Up @@ -133,6 +139,33 @@ cbuffer CBStructs {
uint16_t3 f;
};


class K {
float i;
};

class L : K {
float j;
};

class M {
K array[5];
};

cbuffer CBClasses {
K k;
L l;
M m;
K ka[10];
};

// CHECK: @CBClasses.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CBClasses,
// CHECK-SAME: 260, 0, 16, 32, 112))
// CHECK: @k = external addrspace(2) global target("dx.Layout", %K, 4, 0), align 4
// CHECK: @l = external addrspace(2) global target("dx.Layout", %L, 8, 0, 4), align 4
// CHECK: @m = external addrspace(2) global target("dx.Layout", %M, 68, 0), align 4
// CHECK: @ka = external addrspace(2) global [10 x target("dx.Layout", %K, 4, 0)], align 4

struct Test {
float a, b;
};
Expand Down Expand Up @@ -237,16 +270,16 @@ RWBuffer<float> Buf;

[numthreads(4,1,1)]
void main() {
Buf[0] = a1 + b1.z + c1[2] + a.f1.y + f1 + B1[0].x + B10.z + D1.B2;
Buf[0] = a1 + b1.z + c1[2] + a.f1.y + f1 + B1[0].x + ka[2].i + B10.z + D1.B2;
}

// CHECK: define internal void @_GLOBAL__sub_I_cbuffer.hlsl()
// CHECK-NEXT: entry:
// CHECK-NEXT: call void @_init_resource_CBScalars.cb()
// CHECK-NEXT: call void @_init_resource_CBArrays.cb()

// CHECK: !hlsl.cbs = !{![[CBSCALARS:[0-9]+]], ![[CBVECTORS:[0-9]+]], ![[CBARRAYS:[0-9]+]], ![[CBSTRUCTS:[0-9]+]], ![[CBMIX:[0-9]+]],
// CHECK-SAME: ![[CB_A:[0-9]+]], ![[CB_B:[0-9]+]], ![[CB_C:[0-9]+]]}
// CHECK: !hlsl.cbs = !{![[CBSCALARS:[0-9]+]], ![[CBVECTORS:[0-9]+]], ![[CBARRAYS:[0-9]+]], ![[CBSTRUCTS:[0-9]+]], ![[CBCLASSES:[0-9]+]],
// CHECK-SAME: ![[CBMIX:[0-9]+]], ![[CB_A:[0-9]+]], ![[CB_B:[0-9]+]], ![[CB_C:[0-9]+]]}

// CHECK: ![[CBSCALARS]] = !{ptr @CBScalars.cb, ptr addrspace(2) @a1, ptr addrspace(2) @a2, ptr addrspace(2) @a3, ptr addrspace(2) @a4,
// CHECK-SAME: ptr addrspace(2) @a5, ptr addrspace(2) @a6, ptr addrspace(2) @a7, ptr addrspace(2) @a8}
Expand All @@ -260,6 +293,8 @@ void main() {
// CHECK: ![[CBSTRUCTS]] = !{ptr @CBStructs.cb, ptr addrspace(2) @a, ptr addrspace(2) @b, ptr addrspace(2) @c, ptr addrspace(2) @array_of_A,
// CHECK-SAME: ptr addrspace(2) @d, ptr addrspace(2) @e, ptr addrspace(2) @f}

// CHECK: ![[CBCLASSES]] = !{ptr @CBClasses.cb, ptr addrspace(2) @k, ptr addrspace(2) @l, ptr addrspace(2) @m, ptr addrspace(2) @ka}

// CHECK: ![[CBMIX]] = !{ptr @CBMix.cb, ptr addrspace(2) @test, ptr addrspace(2) @f1, ptr addrspace(2) @f2, ptr addrspace(2) @f3,
// CHECK-SAME: ptr addrspace(2) @f4, ptr addrspace(2) @f5, ptr addrspace(2) @f6, ptr addrspace(2) @f7, ptr addrspace(2) @f8, ptr addrspace(2) @f9}

Expand Down