[SPIR-V] Add .CalculateLevelOfDetailUnclamped() and .Gather() methods for vk::SampledTexture2D type.

include/dxc/dxcapi.internal.h

@@ -136,7 +136,8 @@ enum LEGAL_INTRINSIC_COMPTYPES {
 
 #ifdef ENABLE_SPIRV_CODEGEN
   LICOMPTYPE_VK_BUFFER_POINTER = 54,
-  LICOMPTYPE_COUNT = 55
+  LICOMPTYPE_VK_SAMPLED_TEXTURE2D = 55,
+  LICOMPTYPE_COUNT = 56
 #else
   LICOMPTYPE_COUNT = 54
 #endif

tools/clang/include/clang/AST/HlslTypes.h

@@ -407,6 +407,11 @@ clang::CXXRecordDecl *
 DeclareVkBufferPointerType(clang::ASTContext &context,
                            clang::DeclContext *declContext);
 
+clang::CXXRecordDecl *DeclareVkSampledTexture2DType(
+    clang::ASTContext &context, clang::DeclContext *declContext,
+    clang::QualType float2Type, clang::QualType int2Type,
+    clang::QualType float4Type);
+
 clang::CXXRecordDecl *DeclareInlineSpirvType(clang::ASTContext &context,
                                              clang::DeclContext *declContext,
                                              llvm::StringRef typeName,

tools/clang/include/clang/SPIRV/AstTypeProbe.h

@@ -257,6 +257,9 @@ bool isTexture(QualType);
 /// Texture2DMSArray type.
 bool isTextureMS(QualType);
 
+/// \brief Returns true if the given type is an HLSL SampledTexture type.
+bool isSampledTexture(QualType);
+
 /// \brief Returns true if the given type is an HLSL RWTexture type.
 bool isRWTexture(QualType);
 

tools/clang/include/clang/SPIRV/SpirvBuilder.h

@@ -286,6 +286,9 @@ class SpirvBuilder {
   /// If compareVal is given a non-zero value, *Dref* variants of OpImageSample*
   /// will be generated.
   ///
+  /// If imageType is not a sampled image type, the OpSampledImage* instructions
+  /// will be generated.
+  ///
   /// If lod or grad is given a non-zero value, *ExplicitLod variants of
   /// OpImageSample* will be generated; otherwise, *ImplicitLod variant will
   /// be generated.
@@ -334,6 +337,8 @@ class SpirvBuilder {
 
   /// \brief Creates SPIR-V instructions for gathering the given image.
   ///
+  /// If imageType is not a sampled image type, the OpSampledImage* instructions
+  /// will be generated.
   /// If compareVal is given a non-null value, OpImageDrefGather or
   /// OpImageSparseDrefGather will be generated; otherwise, OpImageGather or
   /// OpImageSparseGather will be generated.

tools/clang/lib/AST/ASTContextHLSL.cpp

@@ -1369,6 +1369,130 @@ CXXRecordDecl *hlsl::DeclareNodeOrRecordType(
 }
 
 #ifdef ENABLE_SPIRV_CODEGEN
+CXXRecordDecl *hlsl::DeclareVkSampledTexture2DType(ASTContext &context,
+                                                   DeclContext *declContext,
+                                                   QualType float2Type,
+                                                   QualType int2Type,
+                                                   QualType float4Type) {
+  BuiltinTypeDeclBuilder Builder(declContext, "SampledTexture2D",
+                                 TagDecl::TagKind::TTK_Struct);
+
+  QualType defaultTextureType = float4Type;
+  TemplateTypeParmDecl *TyParamDecl =
+      Builder.addTypeTemplateParam("SampledTextureType", defaultTextureType);
+
+  Builder.startDefinition();
+
+  QualType paramType = QualType(TyParamDecl->getTypeForDecl(), 0);
+  CXXRecordDecl *recordDecl = Builder.getRecordDecl();
+
+  QualType floatType = context.FloatTy;
+  QualType uintType = context.UnsignedIntTy;
+  // Add Sample method
+  // Sample(location)
+  CXXMethodDecl *sampleDecl = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, paramType, ArrayRef<QualType>(float2Type),
+      ArrayRef<StringRef>(StringRef("location")),
+      context.DeclarationNames.getIdentifier(&context.Idents.get("Sample")),
+      /*isConst*/ true);
+  sampleDecl->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "", static_cast<int>(hlsl::IntrinsicOp::MOP_Sample)));
+  sampleDecl->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+
+  // Sample(location, offset)
+  QualType params2[] = {float2Type, int2Type};
+  StringRef names2[] = {"location", "offset"};
+  CXXMethodDecl *sampleDecl2 = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, paramType, params2, names2,
+      context.DeclarationNames.getIdentifier(&context.Idents.get("Sample")),
+      /*isConst*/ true);
+  sampleDecl2->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "", static_cast<int>(hlsl::IntrinsicOp::MOP_Sample)));
+  sampleDecl2->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+
+  // Sample(location, offset, clamp)
+  QualType params3[] = {float2Type, int2Type, floatType};
+  StringRef names3[] = {"location", "offset", "clamp"};
+  CXXMethodDecl *sampleDecl3 = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, paramType, params3, names3,
+      context.DeclarationNames.getIdentifier(&context.Idents.get("Sample")),
+      /*isConst*/ true);
+  sampleDecl3->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "", static_cast<int>(hlsl::IntrinsicOp::MOP_Sample)));
+  sampleDecl3->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+
+  // Sample(location, offset, clamp, status)
+  QualType params4[] = {float2Type, int2Type, floatType,
+                        context.getLValueReferenceType(uintType)};
+  StringRef names4[] = {"location", "offset", "clamp", "status"};
+  CXXMethodDecl *sampleDecl4 = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, paramType, params4, names4,
+      context.DeclarationNames.getIdentifier(&context.Idents.get("Sample")),
+      /*isConst*/ true);
+  sampleDecl4->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "", static_cast<int>(hlsl::IntrinsicOp::MOP_Sample)));
+  sampleDecl4->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+
+  // CalculateLevelOfDetail(location)
+  CXXMethodDecl *lodDecl = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, floatType, ArrayRef<QualType>(float2Type),
+      ArrayRef<StringRef>(StringRef("location")),
+      context.DeclarationNames.getIdentifier(
+          &context.Idents.get("CalculateLevelOfDetail")),
+      /*isConst*/ true);
+  lodDecl->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "",
+      static_cast<int>(hlsl::IntrinsicOp::MOP_CalculateLevelOfDetail)));
+  lodDecl->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+
+  // CalculateLevelOfDetailUnclamped(location)
+  CXXMethodDecl *lodUnclampedDecl = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, floatType, ArrayRef<QualType>(float2Type),
+      ArrayRef<StringRef>(StringRef("location")),
+      context.DeclarationNames.getIdentifier(
+          &context.Idents.get("CalculateLevelOfDetailUnclamped")),
+      /*isConst*/ true);
+  lodUnclampedDecl->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "",
+      static_cast<int>(
+          hlsl::IntrinsicOp::MOP_CalculateLevelOfDetailUnclamped)));
+  lodUnclampedDecl->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+
+  // Gather(location)
+  CXXMethodDecl *gatherDecl = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, paramType, ArrayRef<QualType>(float2Type),
+      ArrayRef<StringRef>(StringRef("location")),
+      context.DeclarationNames.getIdentifier(&context.Idents.get("Gather")),
+      /*isConst*/ true);
+  gatherDecl->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "", static_cast<int>(hlsl::IntrinsicOp::MOP_Gather)));
+  gatherDecl->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+  // Gather(location, offset)
+  QualType gatherParams2[] = {float2Type, int2Type};
+  StringRef gatherNames2[] = {"location", "offset"};
+  CXXMethodDecl *gatherDecl2 = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, paramType, gatherParams2, gatherNames2,
+      context.DeclarationNames.getIdentifier(&context.Idents.get("Gather")),
+      /*isConst*/ true);
+  gatherDecl2->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "", static_cast<int>(hlsl::IntrinsicOp::MOP_Gather)));
+  gatherDecl2->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+  // Gather(location, offset, status)
+  QualType gatherParams3[] = {float2Type, int2Type,
+                              context.getLValueReferenceType(uintType)};
+  StringRef gatherNames3[] = {"location", "offset", "status"};
+  CXXMethodDecl *gatherDecl3 = CreateObjectFunctionDeclarationWithParams(
+      context, recordDecl, paramType, gatherParams3, gatherNames3,
+      context.DeclarationNames.getIdentifier(&context.Idents.get("Gather")),
+      /*isConst*/ true);
+  gatherDecl3->addAttr(HLSLIntrinsicAttr::CreateImplicit(
+      context, "op", "", static_cast<int>(hlsl::IntrinsicOp::MOP_Gather)));
+  gatherDecl3->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+
+  Builder.completeDefinition();
+  return recordDecl;
+}
+
 CXXRecordDecl *hlsl::DeclareVkBufferPointerType(ASTContext &context,
                                                 DeclContext *declContext) {
   BuiltinTypeDeclBuilder Builder(declContext, "BufferPointer",

tools/clang/lib/SPIRV/AstTypeProbe.cpp

@@ -926,6 +926,17 @@ bool isTexture(QualType type) {
   return false;
 }
 
+bool isSampledTexture(QualType type) {
+  if (const auto *rt = type->getAs<RecordType>()) {
+    const auto name = rt->getDecl()->getName();
+    // TODO(https://github.com/microsoft/DirectXShaderCompiler/issues/7979): Add
+    // other sampled texture types as needed.
+    if (name == "SampledTexture2D")
+      return true;
+  }
+  return false;
+}
+
 bool isTextureMS(QualType type) {
   if (const auto *rt = type->getAs<RecordType>()) {
     const auto name = rt->getDecl()->getName();

tools/clang/lib/SPIRV/LowerTypeVisitor.cpp

@@ -849,6 +849,22 @@ const SpirvType *LowerTypeVisitor::lowerVkTypeInVkNamespace(
     assert(visitedTypeStack.size() == visitedTypeStackSize);
     return pointerType;
   }
+  if (name == "SampledTexture2D") {
+    const auto sampledType = hlsl::GetHLSLResourceResultType(type);
+    auto loweredType = lowerType(getElementType(astContext, sampledType), rule,
+                                 /*isRowMajor*/ llvm::None, srcLoc);
+
+    // Treat bool textures as uint for compatibility with OpTypeImage.
+    if (loweredType == spvContext.getBoolType()) {
+      loweredType = spvContext.getUIntType(32);
+    }
+
+    const auto *imageType = spvContext.getImageType(
+        loweredType, spv::Dim::Dim2D, ImageType::WithDepth::No,
+        false /* array */, false /* ms */, ImageType::WithSampler::Yes,
+        spv::ImageFormat::Unknown);
+    return spvContext.getSampledImageType(imageType);
+  }
   emitError("unknown type %0 in vk namespace", srcLoc) << type;
   return nullptr;
 }

tools/clang/lib/SPIRV/SpirvBuilder.cpp

@@ -620,8 +620,15 @@ SpirvInstruction *SpirvBuilder::createImageSample(
   assert(lod == nullptr || minLod == nullptr);
 
   // An OpSampledImage is required to do the image sampling.
-  auto *sampledImage =
-      createSampledImage(imageType, image, sampler, loc, range);
+  // Skip creating OpSampledImage if the imageType is a sampled texture.
+  SpirvInstruction *sampledImage = nullptr;
+  if (isSampledTexture(imageType)) {
+    assert(!sampler &&
+           "sampler must be null when sampling from a sampled texture");
+    sampledImage = image;
+  } else {
+    sampledImage = createSampledImage(imageType, image, sampler, loc, range);
+  }
 
   const auto mask = composeImageOperandsMask(
       bias, lod, grad, constOffset, varOffset, constOffsets, sample, minLod);
@@ -707,8 +714,15 @@ SpirvInstruction *SpirvBuilder::createImageGather(
   assert(insertPoint && "null insert point");
 
   // An OpSampledImage is required to do the image sampling.
-  auto *sampledImage =
-      createSampledImage(imageType, image, sampler, loc, range);
+  // Skip creating OpSampledImage if the imageType is a sampled texture.
+  SpirvInstruction *sampledImage = nullptr;
+  if (isSampledTexture(imageType)) {
+    assert(!sampler &&
+           "sampler must be null when sampling from a sampled texture");
+    sampledImage = image;
+  } else {
+    sampledImage = createSampledImage(imageType, image, sampler, loc, range);
+  }
 
   // TODO: Update ImageGather to accept minLod if necessary.
   const auto mask = composeImageOperandsMask(

tools/clang/lib/SPIRV/SpirvEmitter.cpp

@@ -4451,15 +4451,25 @@ SpirvEmitter::processTextureLevelOfDetail(const CXXMemberCallExpr *expr,
   // Texture2D(Array).CalculateLevelOfDetail(SamplerState S, float2 xy);
   // TextureCube(Array).CalculateLevelOfDetail(SamplerState S, float3 xyz);
   // Texture3D.CalculateLevelOfDetail(SamplerState S, float3 xyz);
+  // SampledTexture2D.CalculateLevelOfDetail(float2 xy);
   // Return type is always a single float (LOD).
-  assert(expr->getNumArgs() == 2u);
-  const auto *object = expr->getImplicitObjectArgument();
-  auto *objectInfo = loadIfGLValue(object);
-  auto *samplerState = doExpr(expr->getArg(0));
-  auto *coordinate = doExpr(expr->getArg(1));
 
-  auto *sampledImage = spvBuilder.createSampledImage(
-      object->getType(), objectInfo, samplerState, expr->getExprLoc());
+  const auto *imageExpr = expr->getImplicitObjectArgument();
+  const QualType imageType = imageExpr->getType();
+  // numarg is 1 if isSampledTexture(imageType). otherwise 2.
+  assert(expr->getNumArgs() == (isSampledTexture(imageType) ? 1u : 2u));
+
+  auto *objectInfo = loadIfGLValue(imageExpr);
+  auto *samplerState =
+      isSampledTexture(imageType) ? nullptr : doExpr(expr->getArg(0));
+  auto *coordinate = isSampledTexture(imageType) ? doExpr(expr->getArg(0))
+                                                 : doExpr(expr->getArg(1));
+
+  auto *sampledImage =
+      isSampledTexture(imageType)
+          ? objectInfo
+          : spvBuilder.createSampledImage(imageExpr->getType(), objectInfo,
+                                          samplerState, expr->getExprLoc());
 
   // The result type of OpImageQueryLod must be a float2.
   const QualType queryResultType =
@@ -5813,10 +5823,70 @@ SpirvEmitter::processTextureSampleGather(const CXXMemberCallExpr *expr,
   //                                [, uint Status]);
   //
   // Other Texture types do not have a Gather method.
+  //
+  // For SampledTexture2D:
+  // DXGI_FORMAT Object.Sample(float Location
+  //                           [, int Offset]
+  //                           [, float Clamp]
+  //                           [, out uint Status]);
+  //
+  // For SampledTexture2D:
+  // <Template Type>4 Object.Gather(float2|3|4 Location,
+  //                                int2 Offset
+  //                                [, uint Status]);
 
   const auto numArgs = expr->getNumArgs();
   const auto loc = expr->getExprLoc();
   const auto range = expr->getSourceRange();
+
+  const auto *imageExpr = expr->getImplicitObjectArgument();
+  const QualType imageType = imageExpr->getType();
+  const auto retType = expr->getDirectCallee()->getReturnType();
+
+  if (isSampledTexture(imageType)) {
+    auto *sampledImage = loadIfGLValue(imageExpr);
+    auto *coordinate = doExpr(expr->getArg(0));
+    SpirvInstruction *constOffset = nullptr;
+    SpirvInstruction *varOffset = nullptr;
+    SpirvInstruction *clamp = nullptr;
+    SpirvInstruction *status = nullptr;
+
+    if (numArgs > 1) {
+      handleOffsetInMethodCall(expr, 1, &constOffset, &varOffset);
+    }
+    if (isSample) {
+      if (numArgs > 2) {
+        clamp = doExpr(expr->getArg(2));
+      }
+      if (numArgs > 3) {
+        status = doExpr(expr->getArg(3));
+      }
+      return createImageSample(
+          retType, imageType, sampledImage, /*sampler*/ nullptr, coordinate,
+          /*compareVal*/ nullptr, /*bias*/ nullptr,
+          /*lod*/ nullptr, {nullptr, nullptr}, constOffset, varOffset,
+          /*constOffsets*/ nullptr, /*sample*/ nullptr,
+          /*minLod*/ clamp, status, loc, range);
+    } else {
+      if (numArgs > 2) {
+        status = doExpr(expr->getArg(2));
+      }
+      return spvBuilder.createImageGather(
+          retType, imageType, sampledImage, /*sampler*/ nullptr, coordinate,
+          // .Gather() doc says we return four components of red data.
+          spvBuilder.getConstantInt(astContext.IntTy, llvm::APInt(32, 0)),
+          /*compareVal*/ nullptr, constOffset, varOffset,
+          /*constOffsets*/ nullptr, /*sampleNumber*/ nullptr, status, loc,
+          range);
+    }
+  }
+
+  auto *image = loadIfGLValue(imageExpr);
+  auto *sampler = doExpr(expr->getArg(0));
+  auto *coordinate = doExpr(expr->getArg(1));
+  // .Sample()/.Gather() may have a third optional paramter for offset.
+  SpirvInstruction *constOffset = nullptr, *varOffset = nullptr;
+
   const bool hasStatusArg =
       expr->getArg(numArgs - 1)->getType()->isUnsignedIntegerType();
 
@@ -5832,18 +5902,9 @@ SpirvEmitter::processTextureSampleGather(const CXXMemberCallExpr *expr,
   // Subtract 1 for status (if it exists), subtract 1 for clamp (if it exists),
   // and subtract 2 for sampler_state and location.
   const bool hasOffsetArg = numArgs - hasStatusArg - hasClampArg - 2 > 0;
-
-  const auto *imageExpr = expr->getImplicitObjectArgument();
-  const QualType imageType = imageExpr->getType();
-  auto *image = loadIfGLValue(imageExpr);
-  auto *sampler = doExpr(expr->getArg(0));
-  auto *coordinate = doExpr(expr->getArg(1));
-  // .Sample()/.Gather() may have a third optional paramter for offset.
-  SpirvInstruction *constOffset = nullptr, *varOffset = nullptr;
   if (hasOffsetArg)
     handleOffsetInMethodCall(expr, 2, &constOffset, &varOffset);
 
-  const auto retType = expr->getDirectCallee()->getReturnType();
   if (isSample) {
     addDerivativeGroupExecutionMode();
     return createImageSample(retType, imageType, image, sampler, coordinate,