[HLSL] Implement explicit layout for default constant buffer ($Globals) #128991
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@llvm/pr-subscribers-clang-codegen @llvm/pr-subscribers-clang Author: Helena Kotas (hekota) ChangesFixes #126791 Full diff: https://github.com/llvm/llvm-project/pull/128991.diff 10 Files Affected:
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index ed6d2036cb984..67256aa2be339 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -70,7 +70,7 @@ void addDxilValVersion(StringRef ValVersionStr, llvm::Module &M) {
llvm::Type *
CGHLSLRuntime::convertHLSLSpecificType(const Type *T,
- SmallVector<unsigned> *Packoffsets) {
+ SmallVector<int32_t> *Packoffsets) {
assert(T->isHLSLSpecificType() && "Not an HLSL specific type!");
// Check if the target has a specific translation for this type first.
@@ -179,21 +179,45 @@ createBufferHandleType(const HLSLBufferDecl *BufDecl) {
return cast<HLSLAttributedResourceType>(QT.getTypePtr());
}
+// Iterates over all declarations in the HLSL buffer and based on the
+// packoffset or register(c#) annotations it fills outs the Layout
+// vector with the user-specified layout offsets.
+// The buffer offsets can be specified 2 ways:
+// 1. declarations in cbuffer {} block can have a packoffset annotation
+// (translates to HLSLPackOffsetAttr)
+// 2. default constant buffer declarations at global scope can have
+// register(c#) annotations (translates to HLSLResourceBindingAttr with
+// RegisterType::C)
+// It is not quaranteed that all declarations in a buffer have an annotation.
+// For those where it is not specified a -1 value is added to the Layout
+// vector. In the final layout these declarations will be placed at the end
+// of the HLSL buffer after all of the elements with specified offset.
static void fillPackoffsetLayout(const HLSLBufferDecl *BufDecl,
- SmallVector<unsigned> &Layout) {
+ SmallVector<int32_t> &Layout) {
assert(Layout.empty() && "expected empty vector for layout");
assert(BufDecl->hasValidPackoffset());
- for (Decl *D : BufDecl->decls()) {
+ for (Decl *D : BufDecl->buffer_decls()) {
if (isa<CXXRecordDecl, EmptyDecl>(D) || isa<FunctionDecl>(D)) {
continue;
}
VarDecl *VD = dyn_cast<VarDecl>(D);
if (!VD || VD->getType().getAddressSpace() != LangAS::hlsl_constant)
continue;
- assert(VD->hasAttr<HLSLPackOffsetAttr>() &&
- "expected packoffset attribute on every declaration");
- size_t Offset = VD->getAttr<HLSLPackOffsetAttr>()->getOffsetInBytes();
+ size_t Offset = -1;
+ if (VD->hasAttrs()) {
+ for (auto *Attr : VD->getAttrs()) {
+ if (auto *POA = dyn_cast<HLSLPackOffsetAttr>(Attr)) {
+ Offset = POA->getOffsetInBytes();
+ } else if (auto *RBA = dyn_cast<HLSLResourceBindingAttr>(Attr)) {
+ if (RBA->getRegisterType() ==
+ HLSLResourceBindingAttr::RegisterType::C) {
+ // size of constant buffer row is 16 bytes
+ Offset = RBA->getSlotNumber() * 16U;
+ }
+ }
+ }
+ }
Layout.push_back(Offset);
}
}
@@ -212,7 +236,7 @@ void CGHLSLRuntime::addBuffer(const HLSLBufferDecl *BufDecl) {
return;
// create global variable for the constant buffer
- SmallVector<unsigned> Layout;
+ SmallVector<int32_t> Layout;
if (BufDecl->hasValidPackoffset())
fillPackoffsetLayout(BufDecl, Layout);
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.h b/clang/lib/CodeGen/CGHLSLRuntime.h
index a9da42324a038..c4550056175c1 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.h
+++ b/clang/lib/CodeGen/CGHLSLRuntime.h
@@ -146,7 +146,7 @@ class CGHLSLRuntime {
llvm::Type *
convertHLSLSpecificType(const Type *T,
- SmallVector<unsigned> *Packoffsets = nullptr);
+ SmallVector<int32_t> *Packoffsets = nullptr);
void annotateHLSLResource(const VarDecl *D, llvm::GlobalVariable *GV);
void generateGlobalCtorDtorCalls();
diff --git a/clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp b/clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp
index 97262b76c0164..7a92233ac9055 100644
--- a/clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp
+++ b/clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp
@@ -10,6 +10,7 @@
#include "CGHLSLRuntime.h"
#include "CodeGenModule.h"
#include "clang/AST/Type.h"
+#include <climits>
//===----------------------------------------------------------------------===//
// Implementation of constant buffer layout common between DirectX and
@@ -58,9 +59,15 @@ namespace CodeGen {
// 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.
+//
+// When Packoffsets are specified the elements will be placed based on the
+// user-specified offsets. Not all elements must have a packoffset/register(c#)
+// annotation though. For those that don't, the Packoffsets array will constain
+// -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<unsigned> *Packoffsets) {
+ const llvm::SmallVector<int32_t> *Packoffsets) {
// check if we already have the layout type for this struct
if (llvm::TargetExtType *Ty =
@@ -72,6 +79,8 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(
unsigned Index = 0; // packoffset index
unsigned EndOffset = 0;
+ SmallVector<std::pair<const FieldDecl *, unsigned>> DelayLayoutFields;
+
// reserve first spot in the layout vector for buffer size
Layout.push_back(0);
@@ -89,14 +98,57 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(
RecordTypes.pop_back();
for (const auto *FD : RT->getDecl()->fields()) {
- assert((!Packoffsets || Index < Packoffsets->size()) &&
- "number of elements in layout struct does not "
- "match number of packoffset annotations");
+ unsigned FieldOffset = UINT_MAX;
+ llvm::Type *FieldType = nullptr;
+
+ if (Packoffsets) {
+ // have packoffset/register(c#) annotations
+ assert(Index < Packoffsets->size() &&
+ "number of elements in layout struct does not match number of "
+ "packoffset annotations");
+ int PO = (*Packoffsets)[Index++];
+ if (PO != -1) {
+ if (!layoutField(FD, EndOffset, FieldOffset, FieldType, PO))
+ return nullptr;
+ } else {
+ // No packoffset/register(cX) annotation on this field;
+ // Delay the layout until after all of the other elements
+ // annotated with packoffsets/register(cX) are processed.
+ DelayLayoutFields.emplace_back(FD, LayoutElements.size());
+ // reserve space for this field in the layout vector and elements list
+ Layout.push_back(UINT_MAX);
+ LayoutElements.push_back(nullptr);
+ continue;
+ }
+ } else {
+ if (!layoutField(FD, EndOffset, FieldOffset, FieldType))
+ return nullptr;
+ }
+
+ assert(FieldOffset != UINT_MAX && FieldType != nullptr);
+ Layout.push_back((unsigned)FieldOffset);
+ LayoutElements.push_back(FieldType);
+ }
+ }
- if (!layoutField(FD, EndOffset, Layout, LayoutElements,
- Packoffsets ? (*Packoffsets)[Index] : -1))
+ // process delayed layouts
+ if (!DelayLayoutFields.empty()) {
+ for (auto I : DelayLayoutFields) {
+ const FieldDecl *FD = I.first;
+ unsigned IndexInLayoutElements = I.second;
+ // the first item in layout vector is size, so we need to offset the index
+ // by 1
+ unsigned IndexInLayout = IndexInLayoutElements + 1;
+ assert(Layout[IndexInLayout] == UINT_MAX &&
+ LayoutElements[IndexInLayoutElements] == nullptr);
+
+ unsigned FieldOffset = UINT_MAX;
+ llvm::Type *FieldType = nullptr;
+ if (!layoutField(FD, EndOffset, FieldOffset, FieldType))
return nullptr;
- Index++;
+
+ Layout[IndexInLayout] = (unsigned)FieldOffset;
+ LayoutElements[IndexInLayoutElements] = FieldType;
}
}
@@ -122,16 +174,19 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(
// The function converts a single field of HLSL Buffer to its corresponding
// LLVM type and calculates it's layout. Any embedded structs (or
// arrays of structs) are converted to target layout types as well.
-// The converted type is appended to the LayoutElements list, the element
-// offset is added to the Layout list and the EndOffset updated to the offset
-// just after the lay-ed out element (which is basically the size of the
-// buffer).
+// The converted type is set to the FieldType parameter, the element
+// offset is set to the FieldOffset parameter. The EndOffset (=size of the
+// buffer) is also updated accordingly to the offset just after the placed
+// element, unless the incoming EndOffset already larger (may happen in case
+// of unsorted packoffset annotations).
// Returns true if the conversion was successful.
// The packoffset parameter contains the field's layout offset provided by the
// user or -1 if there was no packoffset (or register(cX)) annotation.
-bool HLSLBufferLayoutBuilder::layoutField(
- const FieldDecl *FD, unsigned &EndOffset, SmallVector<unsigned> &Layout,
- SmallVector<llvm::Type *> &LayoutElements, int Packoffset) {
+bool HLSLBufferLayoutBuilder::layoutField(const FieldDecl *FD,
+ unsigned &EndOffset,
+ unsigned &FieldOffset,
+ llvm::Type *&FieldType,
+ int Packoffset) {
// Size of element; for arrays this is a size of a single element in the
// array. Total array size of calculated as (ArrayCount-1) * ArrayStride +
@@ -220,8 +275,8 @@ bool HLSLBufferLayoutBuilder::layoutField(
EndOffset = std::max<unsigned>(EndOffset, NewEndOffset);
// add the layout element and offset to the lists
- Layout.push_back(ElemOffset);
- LayoutElements.push_back(ElemLayoutTy);
+ FieldOffset = ElemOffset;
+ FieldType = ElemLayoutTy;
return true;
}
diff --git a/clang/lib/CodeGen/HLSLBufferLayoutBuilder.h b/clang/lib/CodeGen/HLSLBufferLayoutBuilder.h
index 57bb17c557b9c..b4550757a93b4 100644
--- a/clang/lib/CodeGen/HLSLBufferLayoutBuilder.h
+++ b/clang/lib/CodeGen/HLSLBufferLayoutBuilder.h
@@ -35,13 +35,12 @@ class HLSLBufferLayoutBuilder {
// the Layout is the size followed by offsets for each struct element.
llvm::TargetExtType *
createLayoutType(const RecordType *StructType,
- const llvm::SmallVector<unsigned> *Packoffsets = nullptr);
+ const llvm::SmallVector<int32_t> *Packoffsets = nullptr);
private:
bool layoutField(const clang::FieldDecl *FD, unsigned &EndOffset,
- llvm::SmallVector<unsigned> &Layout,
- llvm::SmallVector<llvm::Type *> &LayoutElements,
- int Packoffset);
+ unsigned &FieldOffset, llvm::Type *&FieldType,
+ int Packoffset = -1);
};
} // namespace CodeGen
diff --git a/clang/lib/CodeGen/TargetInfo.h b/clang/lib/CodeGen/TargetInfo.h
index 86057c14a549e..5df19fbef1e5b 100644
--- a/clang/lib/CodeGen/TargetInfo.h
+++ b/clang/lib/CodeGen/TargetInfo.h
@@ -441,7 +441,7 @@ class TargetCodeGenInfo {
/// Return an LLVM type that corresponds to a HLSL type
virtual llvm::Type *
getHLSLType(CodeGenModule &CGM, const Type *T,
- const SmallVector<unsigned> *Packoffsets = nullptr) const {
+ const SmallVector<int32_t> *Packoffsets = nullptr) const {
return nullptr;
}
diff --git a/clang/lib/CodeGen/Targets/DirectX.cpp b/clang/lib/CodeGen/Targets/DirectX.cpp
index 77091eb45f5cf..88a4b812db675 100644
--- a/clang/lib/CodeGen/Targets/DirectX.cpp
+++ b/clang/lib/CodeGen/Targets/DirectX.cpp
@@ -29,14 +29,14 @@ class DirectXTargetCodeGenInfo : public TargetCodeGenInfo {
DirectXTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
: TargetCodeGenInfo(std::make_unique<DefaultABIInfo>(CGT)) {}
- llvm::Type *getHLSLType(
- CodeGenModule &CGM, const Type *T,
- const SmallVector<unsigned> *Packoffsets = nullptr) const override;
+ llvm::Type *
+ getHLSLType(CodeGenModule &CGM, const Type *T,
+ const SmallVector<int32_t> *Packoffsets = nullptr) const override;
};
llvm::Type *DirectXTargetCodeGenInfo::getHLSLType(
CodeGenModule &CGM, const Type *Ty,
- const SmallVector<unsigned> *Packoffsets) const {
+ const SmallVector<int32_t> *Packoffsets) const {
auto *ResType = dyn_cast<HLSLAttributedResourceType>(Ty);
if (!ResType)
return nullptr;
diff --git a/clang/lib/CodeGen/Targets/SPIR.cpp b/clang/lib/CodeGen/Targets/SPIR.cpp
index c94db31ae1a89..43f511e572d37 100644
--- a/clang/lib/CodeGen/Targets/SPIR.cpp
+++ b/clang/lib/CodeGen/Targets/SPIR.cpp
@@ -52,9 +52,9 @@ class CommonSPIRTargetCodeGenInfo : public TargetCodeGenInfo {
unsigned getOpenCLKernelCallingConv() const override;
llvm::Type *getOpenCLType(CodeGenModule &CGM, const Type *T) const override;
- llvm::Type *getHLSLType(
- CodeGenModule &CGM, const Type *Ty,
- const SmallVector<unsigned> *Packoffsets = nullptr) const override;
+ llvm::Type *
+ getHLSLType(CodeGenModule &CGM, const Type *Ty,
+ const SmallVector<int32_t> *Packoffsets = nullptr) const override;
llvm::Type *getSPIRVImageTypeFromHLSLResource(
const HLSLAttributedResourceType::Attributes &attributes,
llvm::Type *ElementType, llvm::LLVMContext &Ctx) const;
@@ -371,7 +371,7 @@ llvm::Type *CommonSPIRTargetCodeGenInfo::getOpenCLType(CodeGenModule &CGM,
llvm::Type *CommonSPIRTargetCodeGenInfo::getHLSLType(
CodeGenModule &CGM, const Type *Ty,
- const SmallVector<unsigned> *Packoffsets) const {
+ const SmallVector<int32_t> *Packoffsets) const {
auto *ResType = dyn_cast<HLSLAttributedResourceType>(Ty);
if (!ResType)
return nullptr;
diff --git a/clang/lib/Sema/SemaHLSL.cpp b/clang/lib/Sema/SemaHLSL.cpp
index ffc3ac1b65854..507278219e500 100644
--- a/clang/lib/Sema/SemaHLSL.cpp
+++ b/clang/lib/Sema/SemaHLSL.cpp
@@ -1961,6 +1961,18 @@ void SemaHLSL::ActOnEndOfTranslationUnit(TranslationUnitDecl *TU) {
SemaRef.getCurLexicalContext()->addDecl(DefaultCBuffer);
createHostLayoutStructForBuffer(SemaRef, DefaultCBuffer);
+ // Set HasValidPackoffset if any of the decls has a register(c#) annotation;
+ for (const Decl *VD : DefaultCBufferDecls) {
+ if (const HLSLResourceBindingAttr *RBA =
+ VD->getAttr<HLSLResourceBindingAttr>()) {
+ if (RBA->getRegisterType() ==
+ HLSLResourceBindingAttr::RegisterType::C) {
+ DefaultCBuffer->setHasValidPackoffset(true);
+ break;
+ }
+ }
+ }
+
DeclGroupRef DG(DefaultCBuffer);
SemaRef.Consumer.HandleTopLevelDecl(DG);
}
diff --git a/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl b/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
index 870593986a976..81697cdc0f045 100644
--- a/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
+++ b/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
@@ -3,6 +3,7 @@
// RUN: -emit-llvm -disable-llvm-passes -o - | FileCheck %s
// CHECK: %__cblayout_CB = type <{ float, double, <2 x i32> }>
+// CHECK: %__cblayout_CB_1 = type <{ float, <2 x float> }>
// CHECK: @CB.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CB, 176, 16, 168, 88))
// CHECK: @a = external addrspace(2) global float, align 4
@@ -15,6 +16,17 @@ cbuffer CB : register(b1, space3) {
int2 c : packoffset(c5.z);
}
+// CHECK: @CB.cb.1 = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CB_1, 92, 88, 80))
+// CHECK: @x = external addrspace(2) global float, align 4
+// CHECK: @y = external addrspace(2) global <2 x float>, align 8
+
+// Missing packoffset annotation will produce a warning.
+// Element x will be placed after the element y that has an explicit packoffset.
+cbuffer CB : register(b0) {
+ float x;
+ float2 y : packoffset(c5);
+}
+
// CHECK: define internal void @_init_resource_CB.cb()
// CHECK-NEXT: entry:
// CHECK-NEXT: %CB.cb_h = call target("dx.CBuffer", target("dx.Layout", %__cblayout_CB, 176, 16, 168, 88))
@@ -34,5 +46,6 @@ void main() {
foo();
}
-// CHECK: !hlsl.cbs = !{![[CB:[0-9]+]]}
-// CHECK: ![[CB]] = !{ptr @CB.cb, ptr addrspace(2) @a, ptr addrspace(2) @b, ptr addrspace(2) @c}
+// CHECK: !hlsl.cbs = !{![[CB1:[0-9]+]], ![[CB2:[0-9]+]]}
+// CHECK: ![[CB1]] = !{ptr @CB.cb, ptr addrspace(2) @a, ptr addrspace(2) @b, ptr addrspace(2) @c}
+// CHECK: ![[CB2]] = !{ptr @CB.cb.1, ptr addrspace(2) @x, ptr addrspace(2) @y}
diff --git a/clang/test/CodeGenHLSL/default_cbuffer_with_layout.hlsl b/clang/test/CodeGenHLSL/default_cbuffer_with_layout.hlsl
new file mode 100644
index 0000000000000..c4fd83679f84b
--- /dev/null
+++ b/clang/test/CodeGenHLSL/default_cbuffer_with_layout.hlsl
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.3-compute \
+// RUN: -emit-llvm -disable-llvm-passes -o - %s | FileCheck %s
+
+// CHECK: %"__cblayout_$Globals" = type <{ i32, float, [4 x double], <4 x i32>, <4 x float>,
+// CHECK-SAME: target("dx.Layout", %S, 8, 0) }>
+// CHECK: %S = type <{ <2 x float> }>
+
+// CHECK-DAG: @b = external addrspace(2) global float, align 4
+// CHECK-DAG: @d = external addrspace(2) global <4 x i32>, align 16
+// CHECK-DAG: @"$Globals.cb" = external constant target("dx.CBuffer",
+// CHECK-DAG-SAME: target("dx.Layout", %"__cblayout_$Globals", 144, 120, 16, 32, 64, 128, 112))
+// CHECK-DAG: @a = external addrspace(2) global i32, align 4
+// CHECK-DAG: @c = external addrspace(2) global [4 x double], align 8
+// CHECK-DAG: @e = external addrspace(2) global <4 x float>, align 16
+// CHECK-DAG: @s = external addrspace(2) global target("dx.Layout", %S, 8, 0), align 8
+
+struct S {
+ float2 v;
+};
+
+int a;
+float b : register(c1);
+double c[4] : register(c2);
+int4 d : register(c4);
+float4 e;
+S s : register(c7);
+
+RWBuffer<float> Buf;
+
+[numthreads(4,1,1)]
+void main() {
+ Buf[0] = a;
+}
+
+// CHECK: !hlsl.cbs = !{![[CB:.*]]}
+// CHECK: ![[CB]] = !{ptr @"$Globals.cb", ptr addrspace(2) @a, ptr addrspace(2) @b, ptr addrspace(2) @c,
+// CHECK-SAME: ptr addrspace(2) @d, ptr addrspace(2) @e, ptr addrspace(2) @s}
\ No newline at end of file
|
|
@llvm/pr-subscribers-backend-directx Author: Helena Kotas (hekota) ChangesFixes #126791 Full diff: https://github.com/llvm/llvm-project/pull/128991.diff 10 Files Affected:
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index ed6d2036cb984..67256aa2be339 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -70,7 +70,7 @@ void addDxilValVersion(StringRef ValVersionStr, llvm::Module &M) {
llvm::Type *
CGHLSLRuntime::convertHLSLSpecificType(const Type *T,
- SmallVector<unsigned> *Packoffsets) {
+ SmallVector<int32_t> *Packoffsets) {
assert(T->isHLSLSpecificType() && "Not an HLSL specific type!");
// Check if the target has a specific translation for this type first.
@@ -179,21 +179,45 @@ createBufferHandleType(const HLSLBufferDecl *BufDecl) {
return cast<HLSLAttributedResourceType>(QT.getTypePtr());
}
+// Iterates over all declarations in the HLSL buffer and based on the
+// packoffset or register(c#) annotations it fills outs the Layout
+// vector with the user-specified layout offsets.
+// The buffer offsets can be specified 2 ways:
+// 1. declarations in cbuffer {} block can have a packoffset annotation
+// (translates to HLSLPackOffsetAttr)
+// 2. default constant buffer declarations at global scope can have
+// register(c#) annotations (translates to HLSLResourceBindingAttr with
+// RegisterType::C)
+// It is not quaranteed that all declarations in a buffer have an annotation.
+// For those where it is not specified a -1 value is added to the Layout
+// vector. In the final layout these declarations will be placed at the end
+// of the HLSL buffer after all of the elements with specified offset.
static void fillPackoffsetLayout(const HLSLBufferDecl *BufDecl,
- SmallVector<unsigned> &Layout) {
+ SmallVector<int32_t> &Layout) {
assert(Layout.empty() && "expected empty vector for layout");
assert(BufDecl->hasValidPackoffset());
- for (Decl *D : BufDecl->decls()) {
+ for (Decl *D : BufDecl->buffer_decls()) {
if (isa<CXXRecordDecl, EmptyDecl>(D) || isa<FunctionDecl>(D)) {
continue;
}
VarDecl *VD = dyn_cast<VarDecl>(D);
if (!VD || VD->getType().getAddressSpace() != LangAS::hlsl_constant)
continue;
- assert(VD->hasAttr<HLSLPackOffsetAttr>() &&
- "expected packoffset attribute on every declaration");
- size_t Offset = VD->getAttr<HLSLPackOffsetAttr>()->getOffsetInBytes();
+ size_t Offset = -1;
+ if (VD->hasAttrs()) {
+ for (auto *Attr : VD->getAttrs()) {
+ if (auto *POA = dyn_cast<HLSLPackOffsetAttr>(Attr)) {
+ Offset = POA->getOffsetInBytes();
+ } else if (auto *RBA = dyn_cast<HLSLResourceBindingAttr>(Attr)) {
+ if (RBA->getRegisterType() ==
+ HLSLResourceBindingAttr::RegisterType::C) {
+ // size of constant buffer row is 16 bytes
+ Offset = RBA->getSlotNumber() * 16U;
+ }
+ }
+ }
+ }
Layout.push_back(Offset);
}
}
@@ -212,7 +236,7 @@ void CGHLSLRuntime::addBuffer(const HLSLBufferDecl *BufDecl) {
return;
// create global variable for the constant buffer
- SmallVector<unsigned> Layout;
+ SmallVector<int32_t> Layout;
if (BufDecl->hasValidPackoffset())
fillPackoffsetLayout(BufDecl, Layout);
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.h b/clang/lib/CodeGen/CGHLSLRuntime.h
index a9da42324a038..c4550056175c1 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.h
+++ b/clang/lib/CodeGen/CGHLSLRuntime.h
@@ -146,7 +146,7 @@ class CGHLSLRuntime {
llvm::Type *
convertHLSLSpecificType(const Type *T,
- SmallVector<unsigned> *Packoffsets = nullptr);
+ SmallVector<int32_t> *Packoffsets = nullptr);
void annotateHLSLResource(const VarDecl *D, llvm::GlobalVariable *GV);
void generateGlobalCtorDtorCalls();
diff --git a/clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp b/clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp
index 97262b76c0164..7a92233ac9055 100644
--- a/clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp
+++ b/clang/lib/CodeGen/HLSLBufferLayoutBuilder.cpp
@@ -10,6 +10,7 @@
#include "CGHLSLRuntime.h"
#include "CodeGenModule.h"
#include "clang/AST/Type.h"
+#include <climits>
//===----------------------------------------------------------------------===//
// Implementation of constant buffer layout common between DirectX and
@@ -58,9 +59,15 @@ namespace CodeGen {
// 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.
+//
+// When Packoffsets are specified the elements will be placed based on the
+// user-specified offsets. Not all elements must have a packoffset/register(c#)
+// annotation though. For those that don't, the Packoffsets array will constain
+// -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<unsigned> *Packoffsets) {
+ const llvm::SmallVector<int32_t> *Packoffsets) {
// check if we already have the layout type for this struct
if (llvm::TargetExtType *Ty =
@@ -72,6 +79,8 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(
unsigned Index = 0; // packoffset index
unsigned EndOffset = 0;
+ SmallVector<std::pair<const FieldDecl *, unsigned>> DelayLayoutFields;
+
// reserve first spot in the layout vector for buffer size
Layout.push_back(0);
@@ -89,14 +98,57 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(
RecordTypes.pop_back();
for (const auto *FD : RT->getDecl()->fields()) {
- assert((!Packoffsets || Index < Packoffsets->size()) &&
- "number of elements in layout struct does not "
- "match number of packoffset annotations");
+ unsigned FieldOffset = UINT_MAX;
+ llvm::Type *FieldType = nullptr;
+
+ if (Packoffsets) {
+ // have packoffset/register(c#) annotations
+ assert(Index < Packoffsets->size() &&
+ "number of elements in layout struct does not match number of "
+ "packoffset annotations");
+ int PO = (*Packoffsets)[Index++];
+ if (PO != -1) {
+ if (!layoutField(FD, EndOffset, FieldOffset, FieldType, PO))
+ return nullptr;
+ } else {
+ // No packoffset/register(cX) annotation on this field;
+ // Delay the layout until after all of the other elements
+ // annotated with packoffsets/register(cX) are processed.
+ DelayLayoutFields.emplace_back(FD, LayoutElements.size());
+ // reserve space for this field in the layout vector and elements list
+ Layout.push_back(UINT_MAX);
+ LayoutElements.push_back(nullptr);
+ continue;
+ }
+ } else {
+ if (!layoutField(FD, EndOffset, FieldOffset, FieldType))
+ return nullptr;
+ }
+
+ assert(FieldOffset != UINT_MAX && FieldType != nullptr);
+ Layout.push_back((unsigned)FieldOffset);
+ LayoutElements.push_back(FieldType);
+ }
+ }
- if (!layoutField(FD, EndOffset, Layout, LayoutElements,
- Packoffsets ? (*Packoffsets)[Index] : -1))
+ // process delayed layouts
+ if (!DelayLayoutFields.empty()) {
+ for (auto I : DelayLayoutFields) {
+ const FieldDecl *FD = I.first;
+ unsigned IndexInLayoutElements = I.second;
+ // the first item in layout vector is size, so we need to offset the index
+ // by 1
+ unsigned IndexInLayout = IndexInLayoutElements + 1;
+ assert(Layout[IndexInLayout] == UINT_MAX &&
+ LayoutElements[IndexInLayoutElements] == nullptr);
+
+ unsigned FieldOffset = UINT_MAX;
+ llvm::Type *FieldType = nullptr;
+ if (!layoutField(FD, EndOffset, FieldOffset, FieldType))
return nullptr;
- Index++;
+
+ Layout[IndexInLayout] = (unsigned)FieldOffset;
+ LayoutElements[IndexInLayoutElements] = FieldType;
}
}
@@ -122,16 +174,19 @@ llvm::TargetExtType *HLSLBufferLayoutBuilder::createLayoutType(
// The function converts a single field of HLSL Buffer to its corresponding
// LLVM type and calculates it's layout. Any embedded structs (or
// arrays of structs) are converted to target layout types as well.
-// The converted type is appended to the LayoutElements list, the element
-// offset is added to the Layout list and the EndOffset updated to the offset
-// just after the lay-ed out element (which is basically the size of the
-// buffer).
+// The converted type is set to the FieldType parameter, the element
+// offset is set to the FieldOffset parameter. The EndOffset (=size of the
+// buffer) is also updated accordingly to the offset just after the placed
+// element, unless the incoming EndOffset already larger (may happen in case
+// of unsorted packoffset annotations).
// Returns true if the conversion was successful.
// The packoffset parameter contains the field's layout offset provided by the
// user or -1 if there was no packoffset (or register(cX)) annotation.
-bool HLSLBufferLayoutBuilder::layoutField(
- const FieldDecl *FD, unsigned &EndOffset, SmallVector<unsigned> &Layout,
- SmallVector<llvm::Type *> &LayoutElements, int Packoffset) {
+bool HLSLBufferLayoutBuilder::layoutField(const FieldDecl *FD,
+ unsigned &EndOffset,
+ unsigned &FieldOffset,
+ llvm::Type *&FieldType,
+ int Packoffset) {
// Size of element; for arrays this is a size of a single element in the
// array. Total array size of calculated as (ArrayCount-1) * ArrayStride +
@@ -220,8 +275,8 @@ bool HLSLBufferLayoutBuilder::layoutField(
EndOffset = std::max<unsigned>(EndOffset, NewEndOffset);
// add the layout element and offset to the lists
- Layout.push_back(ElemOffset);
- LayoutElements.push_back(ElemLayoutTy);
+ FieldOffset = ElemOffset;
+ FieldType = ElemLayoutTy;
return true;
}
diff --git a/clang/lib/CodeGen/HLSLBufferLayoutBuilder.h b/clang/lib/CodeGen/HLSLBufferLayoutBuilder.h
index 57bb17c557b9c..b4550757a93b4 100644
--- a/clang/lib/CodeGen/HLSLBufferLayoutBuilder.h
+++ b/clang/lib/CodeGen/HLSLBufferLayoutBuilder.h
@@ -35,13 +35,12 @@ class HLSLBufferLayoutBuilder {
// the Layout is the size followed by offsets for each struct element.
llvm::TargetExtType *
createLayoutType(const RecordType *StructType,
- const llvm::SmallVector<unsigned> *Packoffsets = nullptr);
+ const llvm::SmallVector<int32_t> *Packoffsets = nullptr);
private:
bool layoutField(const clang::FieldDecl *FD, unsigned &EndOffset,
- llvm::SmallVector<unsigned> &Layout,
- llvm::SmallVector<llvm::Type *> &LayoutElements,
- int Packoffset);
+ unsigned &FieldOffset, llvm::Type *&FieldType,
+ int Packoffset = -1);
};
} // namespace CodeGen
diff --git a/clang/lib/CodeGen/TargetInfo.h b/clang/lib/CodeGen/TargetInfo.h
index 86057c14a549e..5df19fbef1e5b 100644
--- a/clang/lib/CodeGen/TargetInfo.h
+++ b/clang/lib/CodeGen/TargetInfo.h
@@ -441,7 +441,7 @@ class TargetCodeGenInfo {
/// Return an LLVM type that corresponds to a HLSL type
virtual llvm::Type *
getHLSLType(CodeGenModule &CGM, const Type *T,
- const SmallVector<unsigned> *Packoffsets = nullptr) const {
+ const SmallVector<int32_t> *Packoffsets = nullptr) const {
return nullptr;
}
diff --git a/clang/lib/CodeGen/Targets/DirectX.cpp b/clang/lib/CodeGen/Targets/DirectX.cpp
index 77091eb45f5cf..88a4b812db675 100644
--- a/clang/lib/CodeGen/Targets/DirectX.cpp
+++ b/clang/lib/CodeGen/Targets/DirectX.cpp
@@ -29,14 +29,14 @@ class DirectXTargetCodeGenInfo : public TargetCodeGenInfo {
DirectXTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
: TargetCodeGenInfo(std::make_unique<DefaultABIInfo>(CGT)) {}
- llvm::Type *getHLSLType(
- CodeGenModule &CGM, const Type *T,
- const SmallVector<unsigned> *Packoffsets = nullptr) const override;
+ llvm::Type *
+ getHLSLType(CodeGenModule &CGM, const Type *T,
+ const SmallVector<int32_t> *Packoffsets = nullptr) const override;
};
llvm::Type *DirectXTargetCodeGenInfo::getHLSLType(
CodeGenModule &CGM, const Type *Ty,
- const SmallVector<unsigned> *Packoffsets) const {
+ const SmallVector<int32_t> *Packoffsets) const {
auto *ResType = dyn_cast<HLSLAttributedResourceType>(Ty);
if (!ResType)
return nullptr;
diff --git a/clang/lib/CodeGen/Targets/SPIR.cpp b/clang/lib/CodeGen/Targets/SPIR.cpp
index c94db31ae1a89..43f511e572d37 100644
--- a/clang/lib/CodeGen/Targets/SPIR.cpp
+++ b/clang/lib/CodeGen/Targets/SPIR.cpp
@@ -52,9 +52,9 @@ class CommonSPIRTargetCodeGenInfo : public TargetCodeGenInfo {
unsigned getOpenCLKernelCallingConv() const override;
llvm::Type *getOpenCLType(CodeGenModule &CGM, const Type *T) const override;
- llvm::Type *getHLSLType(
- CodeGenModule &CGM, const Type *Ty,
- const SmallVector<unsigned> *Packoffsets = nullptr) const override;
+ llvm::Type *
+ getHLSLType(CodeGenModule &CGM, const Type *Ty,
+ const SmallVector<int32_t> *Packoffsets = nullptr) const override;
llvm::Type *getSPIRVImageTypeFromHLSLResource(
const HLSLAttributedResourceType::Attributes &attributes,
llvm::Type *ElementType, llvm::LLVMContext &Ctx) const;
@@ -371,7 +371,7 @@ llvm::Type *CommonSPIRTargetCodeGenInfo::getOpenCLType(CodeGenModule &CGM,
llvm::Type *CommonSPIRTargetCodeGenInfo::getHLSLType(
CodeGenModule &CGM, const Type *Ty,
- const SmallVector<unsigned> *Packoffsets) const {
+ const SmallVector<int32_t> *Packoffsets) const {
auto *ResType = dyn_cast<HLSLAttributedResourceType>(Ty);
if (!ResType)
return nullptr;
diff --git a/clang/lib/Sema/SemaHLSL.cpp b/clang/lib/Sema/SemaHLSL.cpp
index ffc3ac1b65854..507278219e500 100644
--- a/clang/lib/Sema/SemaHLSL.cpp
+++ b/clang/lib/Sema/SemaHLSL.cpp
@@ -1961,6 +1961,18 @@ void SemaHLSL::ActOnEndOfTranslationUnit(TranslationUnitDecl *TU) {
SemaRef.getCurLexicalContext()->addDecl(DefaultCBuffer);
createHostLayoutStructForBuffer(SemaRef, DefaultCBuffer);
+ // Set HasValidPackoffset if any of the decls has a register(c#) annotation;
+ for (const Decl *VD : DefaultCBufferDecls) {
+ if (const HLSLResourceBindingAttr *RBA =
+ VD->getAttr<HLSLResourceBindingAttr>()) {
+ if (RBA->getRegisterType() ==
+ HLSLResourceBindingAttr::RegisterType::C) {
+ DefaultCBuffer->setHasValidPackoffset(true);
+ break;
+ }
+ }
+ }
+
DeclGroupRef DG(DefaultCBuffer);
SemaRef.Consumer.HandleTopLevelDecl(DG);
}
diff --git a/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl b/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
index 870593986a976..81697cdc0f045 100644
--- a/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
+++ b/clang/test/CodeGenHLSL/cbuffer_with_packoffset.hlsl
@@ -3,6 +3,7 @@
// RUN: -emit-llvm -disable-llvm-passes -o - | FileCheck %s
// CHECK: %__cblayout_CB = type <{ float, double, <2 x i32> }>
+// CHECK: %__cblayout_CB_1 = type <{ float, <2 x float> }>
// CHECK: @CB.cb = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CB, 176, 16, 168, 88))
// CHECK: @a = external addrspace(2) global float, align 4
@@ -15,6 +16,17 @@ cbuffer CB : register(b1, space3) {
int2 c : packoffset(c5.z);
}
+// CHECK: @CB.cb.1 = external constant target("dx.CBuffer", target("dx.Layout", %__cblayout_CB_1, 92, 88, 80))
+// CHECK: @x = external addrspace(2) global float, align 4
+// CHECK: @y = external addrspace(2) global <2 x float>, align 8
+
+// Missing packoffset annotation will produce a warning.
+// Element x will be placed after the element y that has an explicit packoffset.
+cbuffer CB : register(b0) {
+ float x;
+ float2 y : packoffset(c5);
+}
+
// CHECK: define internal void @_init_resource_CB.cb()
// CHECK-NEXT: entry:
// CHECK-NEXT: %CB.cb_h = call target("dx.CBuffer", target("dx.Layout", %__cblayout_CB, 176, 16, 168, 88))
@@ -34,5 +46,6 @@ void main() {
foo();
}
-// CHECK: !hlsl.cbs = !{![[CB:[0-9]+]]}
-// CHECK: ![[CB]] = !{ptr @CB.cb, ptr addrspace(2) @a, ptr addrspace(2) @b, ptr addrspace(2) @c}
+// CHECK: !hlsl.cbs = !{![[CB1:[0-9]+]], ![[CB2:[0-9]+]]}
+// CHECK: ![[CB1]] = !{ptr @CB.cb, ptr addrspace(2) @a, ptr addrspace(2) @b, ptr addrspace(2) @c}
+// CHECK: ![[CB2]] = !{ptr @CB.cb.1, ptr addrspace(2) @x, ptr addrspace(2) @y}
diff --git a/clang/test/CodeGenHLSL/default_cbuffer_with_layout.hlsl b/clang/test/CodeGenHLSL/default_cbuffer_with_layout.hlsl
new file mode 100644
index 0000000000000..c4fd83679f84b
--- /dev/null
+++ b/clang/test/CodeGenHLSL/default_cbuffer_with_layout.hlsl
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.3-compute \
+// RUN: -emit-llvm -disable-llvm-passes -o - %s | FileCheck %s
+
+// CHECK: %"__cblayout_$Globals" = type <{ i32, float, [4 x double], <4 x i32>, <4 x float>,
+// CHECK-SAME: target("dx.Layout", %S, 8, 0) }>
+// CHECK: %S = type <{ <2 x float> }>
+
+// CHECK-DAG: @b = external addrspace(2) global float, align 4
+// CHECK-DAG: @d = external addrspace(2) global <4 x i32>, align 16
+// CHECK-DAG: @"$Globals.cb" = external constant target("dx.CBuffer",
+// CHECK-DAG-SAME: target("dx.Layout", %"__cblayout_$Globals", 144, 120, 16, 32, 64, 128, 112))
+// CHECK-DAG: @a = external addrspace(2) global i32, align 4
+// CHECK-DAG: @c = external addrspace(2) global [4 x double], align 8
+// CHECK-DAG: @e = external addrspace(2) global <4 x float>, align 16
+// CHECK-DAG: @s = external addrspace(2) global target("dx.Layout", %S, 8, 0), align 8
+
+struct S {
+ float2 v;
+};
+
+int a;
+float b : register(c1);
+double c[4] : register(c2);
+int4 d : register(c4);
+float4 e;
+S s : register(c7);
+
+RWBuffer<float> Buf;
+
+[numthreads(4,1,1)]
+void main() {
+ Buf[0] = a;
+}
+
+// CHECK: !hlsl.cbs = !{![[CB:.*]]}
+// CHECK: ![[CB]] = !{ptr @"$Globals.cb", ptr addrspace(2) @a, ptr addrspace(2) @b, ptr addrspace(2) @c,
+// CHECK-SAME: ptr addrspace(2) @d, ptr addrspace(2) @e, ptr addrspace(2) @s}
\ No newline at end of file
|
hekota
changed the title
damyanp
reviewed
Feb 27, 2025
clang/lib/CodeGen/CGHLSLRuntime.cpp
Outdated
Comment on lines
215
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216
| // size of constant buffer row is 16 bytes | ||
| Offset = RBA->getSlotNumber() * 16U; |
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It'd be nice if there was a named constant for this. At very least you wouldn't need the comment. At best, we have an easy way to find all the places that depend on the constant buffer row size.
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I think there's a CBufferAlign in SemaHLSL.cpp. A BufferRowAlign in HLSLBufferLayoutBuilder.cpp. Maybe these are the same concept?
(If so, maybe reconciling them is outside scope of this PR)
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I've named the constant and placed it in CGHLSLRuntime. Codegen does not have a dependency on Sema.
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Thanks, I think this is probably fine here, but I wonder more generally if there's any way we can get Sema and CG to agree on constants and things like that? Does Sema depend on Codegen?
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Processes
HLSLResourceBindingAttrattributes that representregister(c#)annotations on default constant buffer declarations and applies its value to the buffer layout. Any default buffer declarations without an explicitregister(c#)annotation are placed after the elements with explicit layout.This PR also adds a test case for a
cbufferthat does not havepackoffseton all declarations. Same layout rules apply here as well.Fixes #126791