[DirectX] Create symbols for resource handles (#119775)

We need to create symbols with "the original shape of resource and
element type" to put in the resource metadata in order to generate valid
DXIL.

Note that DXC generally doesn't emit an actual symbol outside of library
shaders (it emits an undef of a pointer to the type), but since we have
to deal with opaque pointers we would need a way to smuggle the type
through to match that. Instead, we simply emit symbols for now.

Fixed #116849

Author: bogner

llvm/include/llvm/Analysis/DXILResource.h

@@ -271,6 +271,7 @@ class ResourceTypeInfo {
                          GloballyCoherent, HasCounter) {}
 
   TargetExtType *getHandleTy() const { return HandleTy; }
+  StructType *createElementStruct();
 
   // Conditions to check before accessing specific views.
   bool isUAV() const;
@@ -329,28 +330,31 @@ class ResourceBindingInfo {
 private:
   ResourceBinding Binding;
   TargetExtType *HandleTy;
+  GlobalVariable *Symbol = nullptr;
 
 public:
   ResourceBindingInfo(uint32_t RecordID, uint32_t Space, uint32_t LowerBound,
-                      uint32_t Size, TargetExtType *HandleTy)
-      : Binding{RecordID, Space, LowerBound, Size}, HandleTy(HandleTy) {}
+                      uint32_t Size, TargetExtType *HandleTy,
+                      GlobalVariable *Symbol = nullptr)
+      : Binding{RecordID, Space, LowerBound, Size}, HandleTy(HandleTy),
+        Symbol(Symbol) {}
 
   void setBindingID(unsigned ID) { Binding.RecordID = ID; }
 
   const ResourceBinding &getBinding() const { return Binding; }
   TargetExtType *getHandleTy() const { return HandleTy; }
-  const StringRef getName() const {
-    // TODO: Get the name from the symbol once we include one here.
-    return "";
-  }
+  const StringRef getName() const { return Symbol ? Symbol->getName() : ""; }
 
+  bool hasSymbol() const { return Symbol; }
+  GlobalVariable *createSymbol(Module &M, StructType *Ty, StringRef Name = "");
   MDTuple *getAsMetadata(Module &M, dxil::ResourceTypeInfo &RTI) const;
 
   std::pair<uint32_t, uint32_t>
   getAnnotateProps(Module &M, dxil::ResourceTypeInfo &RTI) const;
 
   bool operator==(const ResourceBindingInfo &RHS) const {
-    return std::tie(Binding, HandleTy) == std::tie(RHS.Binding, RHS.HandleTy);
+    return std::tie(Binding, HandleTy, Symbol) ==
+           std::tie(RHS.Binding, RHS.HandleTy, RHS.Symbol);
   }
   bool operator!=(const ResourceBindingInfo &RHS) const {
     return !(*this == RHS);

llvm/lib/Analysis/DXILResource.cpp

@@ -216,6 +216,81 @@ ResourceTypeInfo::ResourceTypeInfo(TargetExtType *HandleTy,
     llvm_unreachable("Unknown handle type");
 }
 
+static void formatTypeName(SmallString<64> &Dest, StringRef Name,
+                           bool isWriteable, bool isROV) {
+  Dest = isWriteable ? (isROV ? "RasterizerOrdered" : "RW") : "";
+  Dest += Name;
+}
+
+StructType *ResourceTypeInfo::createElementStruct() {
+  SmallString<64> TypeName;
+
+  switch (Kind) {
+  case ResourceKind::Texture1D:
+  case ResourceKind::Texture2D:
+  case ResourceKind::Texture3D:
+  case ResourceKind::TextureCube:
+  case ResourceKind::Texture1DArray:
+  case ResourceKind::Texture2DArray:
+  case ResourceKind::TextureCubeArray: {
+    auto *RTy = cast<TextureExtType>(HandleTy);
+    formatTypeName(TypeName, getResourceKindName(Kind), RTy->isWriteable(),
+                   RTy->isROV());
+    return StructType::create(RTy->getResourceType(), TypeName);
+  }
+  case ResourceKind::Texture2DMS:
+  case ResourceKind::Texture2DMSArray: {
+    auto *RTy = cast<MSTextureExtType>(HandleTy);
+    formatTypeName(TypeName, getResourceKindName(Kind), RTy->isWriteable(),
+                   /*IsROV=*/false);
+    return StructType::create(RTy->getResourceType(), TypeName);
+  }
+  case ResourceKind::TypedBuffer: {
+    auto *RTy = cast<TypedBufferExtType>(HandleTy);
+    formatTypeName(TypeName, getResourceKindName(Kind), RTy->isWriteable(),
+                   RTy->isROV());
+    return StructType::create(RTy->getResourceType(), TypeName);
+  }
+  case ResourceKind::RawBuffer: {
+    auto *RTy = cast<RawBufferExtType>(HandleTy);
+    formatTypeName(TypeName, "ByteAddressBuffer", RTy->isWriteable(),
+                   RTy->isROV());
+    return StructType::create(Type::getInt32Ty(HandleTy->getContext()),
+                              TypeName);
+  }
+  case ResourceKind::StructuredBuffer: {
+    auto *RTy = cast<RawBufferExtType>(HandleTy);
+    formatTypeName(TypeName, "StructuredBuffer", RTy->isWriteable(),
+                   RTy->isROV());
+    return StructType::create(RTy->getResourceType(), TypeName);
+  }
+  case ResourceKind::FeedbackTexture2D:
+  case ResourceKind::FeedbackTexture2DArray: {
+    auto *RTy = cast<FeedbackTextureExtType>(HandleTy);
+    TypeName = formatv("{0}<{1}>", getResourceKindName(Kind),
+                       llvm::to_underlying(RTy->getFeedbackType()));
+    return StructType::create(Type::getInt32Ty(HandleTy->getContext()),
+                              TypeName);
+  }
+  case ResourceKind::CBuffer:
+    return StructType::create(HandleTy->getContext(), "cbuffer");
+  case ResourceKind::Sampler: {
+    auto *RTy = cast<SamplerExtType>(HandleTy);
+    TypeName = formatv("SamplerState<{0}>",
+                       llvm::to_underlying(RTy->getSamplerType()));
+    return StructType::create(Type::getInt32Ty(HandleTy->getContext()),
+                              TypeName);
+  }
+  case ResourceKind::TBuffer:
+  case ResourceKind::RTAccelerationStructure:
+    llvm_unreachable("Unhandled resource kind");
+  case ResourceKind::Invalid:
+  case ResourceKind::NumEntries:
+    llvm_unreachable("Invalid resource kind");
+  }
+  llvm_unreachable("Unhandled ResourceKind enum");
+}
+
 bool ResourceTypeInfo::isUAV() const { return RC == ResourceClass::UAV; }
 
 bool ResourceTypeInfo::isCBuffer() const {
@@ -449,6 +524,15 @@ void ResourceTypeInfo::print(raw_ostream &OS, const DataLayout &DL) const {
   }
 }
 
+GlobalVariable *ResourceBindingInfo::createSymbol(Module &M, StructType *Ty,
+                                                  StringRef Name) {
+  assert(!Symbol && "Symbol has already been created");
+  Symbol = new GlobalVariable(M, Ty, /*isConstant=*/true,
+                              GlobalValue::ExternalLinkage,
+                              /*Initializer=*/nullptr, Name);
+  return Symbol;
+}
+
 MDTuple *ResourceBindingInfo::getAsMetadata(Module &M,
                                             dxil::ResourceTypeInfo &RTI) const {
   LLVMContext &Ctx = M.getContext();
@@ -468,13 +552,9 @@ MDTuple *ResourceBindingInfo::getAsMetadata(Module &M,
   };
 
   MDVals.push_back(getIntMD(Binding.RecordID));
-
-  // TODO: We need API to create a symbol of the appropriate type to emit here.
-  // See https://github.com/llvm/llvm-project/issues/116849
-  MDVals.push_back(
-      ValueAsMetadata::get(UndefValue::get(PointerType::getUnqual(Ctx))));
-  MDVals.push_back(MDString::get(Ctx, ""));
-
+  assert(Symbol && "Cannot yet create useful resource metadata without symbol");
+  MDVals.push_back(ValueAsMetadata::get(Symbol));
+  MDVals.push_back(MDString::get(Ctx, Symbol->getName()));
   MDVals.push_back(getIntMD(Binding.Space));
   MDVals.push_back(getIntMD(Binding.LowerBound));
   MDVals.push_back(getIntMD(Binding.Size));
@@ -573,6 +653,12 @@ ResourceBindingInfo::getAnnotateProps(Module &M,
 
 void ResourceBindingInfo::print(raw_ostream &OS, dxil::ResourceTypeInfo &RTI,
                                 const DataLayout &DL) const {
+  if (Symbol) {
+    OS << "  Symbol: ";
+    Symbol->printAsOperand(OS);
+    OS << "\n";
+  }
+
   OS << "  Binding:\n"
      << "    Record ID: " << Binding.RecordID << "\n"
      << "    Space: " << Binding.Space << "\n"

llvm/lib/Target/DirectX/DXILTranslateMetadata.cpp

@@ -77,6 +77,10 @@ static NamedMDNode *emitResourceMetadata(Module &M, DXILBindingMap &DBM,
                                          const dxil::Resources &MDResources) {
   LLVMContext &Context = M.getContext();
 
+  for (ResourceBindingInfo &RI : DBM)
+    if (!RI.hasSymbol())
+      RI.createSymbol(M, DRTM[RI.getHandleTy()].createElementStruct());
+
   SmallVector<Metadata *> SRVs, UAVs, CBufs, Smps;
   for (const ResourceBindingInfo &RI : DBM.srvs())
     SRVs.push_back(RI.getAsMetadata(M, DRTM[RI.getHandleTy()]));

llvm/test/CodeGen/DirectX/Metadata/resource-symbols.ll

@@ -0,0 +1,48 @@
+; RUN: opt -S -passes=dxil-translate-metadata %s | FileCheck %s
+
+target triple = "dxil-pc-shadermodel6.6-compute"
+
+%struct.S = type { <4 x float>, <4 x i32> }
+
+define void @test() {
+  ; Buffer<float4>
+  %float4 = call target("dx.TypedBuffer", <4 x float>, 0, 0, 0)
+      @llvm.dx.handle.fromBinding(i32 0, i32 0, i32 1, i32 0, i1 false)
+  ; CHECK: %TypedBuffer = type { <4 x float> }
+
+  ; Buffer<int>
+  %int = call target("dx.TypedBuffer", i32, 0, 0, 1)
+      @llvm.dx.handle.fromBinding(i32 0, i32 1, i32 1, i32 0, i1 false)
+  ; CHECK: %TypedBuffer.0 = type { i32 }
+
+  ; Buffer<uint3>
+  %uint3 = call target("dx.TypedBuffer", <3 x i32>, 0, 0, 0)
+      @llvm.dx.handle.fromBinding(i32 0, i32 2, i32 1, i32 0, i1 false)
+  ; CHECK: %TypedBuffer.1 = type { <3 x i32> }
+
+  ; StructuredBuffer<S>
+  %struct0 = call target("dx.RawBuffer", %struct.S, 0, 0)
+      @llvm.dx.handle.fromBinding(i32 0, i32 10, i32 1, i32 0, i1 true)
+  ; CHECK: %StructuredBuffer = type { %struct.S }
+
+  ; ByteAddressBuffer
+  %byteaddr = call target("dx.RawBuffer", i8, 0, 0)
+      @llvm.dx.handle.fromBinding(i32 0, i32 20, i32 1, i32 0, i1 false)
+  ; CHECK: %ByteAddressBuffer = type { i32 }
+
+  ret void
+}
+
+; CHECK:      @[[T0:.*]] = external constant %TypedBuffer
+; CHECK-NEXT: @[[T1:.*]] = external constant %TypedBuffer.0
+; CHECK-NEXT: @[[T2:.*]] = external constant %TypedBuffer.1
+; CHECK-NEXT: @[[S0:.*]] = external constant %StructuredBuffer
+; CHECK-NEXT: @[[B0:.*]] = external constant %ByteAddressBuffer
+
+; CHECK: !{i32 0, ptr @[[T0]], !""
+; CHECK: !{i32 1, ptr @[[T1]], !""
+; CHECK: !{i32 2, ptr @[[T2]], !""
+; CHECK: !{i32 3, ptr @[[S0]], !""
+; CHECK: !{i32 4, ptr @[[B0]], !""
+
+attributes #0 = { nocallback nofree nosync nounwind willreturn memory(none) }