[SPIR-V] Implement remaining .Sample... methods for vk::SampledTexture2D type.

include/dxc/dxcapi.internal.h

@@ -138,7 +138,8 @@ enum LEGAL_INTRINSIC_COMPTYPES {
 
 #ifdef ENABLE_SPIRV_CODEGEN
   LICOMPTYPE_VK_BUFFER_POINTER = 55,
-  LICOMPTYPE_COUNT = 56
+  LICOMPTYPE_VK_SAMPLED_TEXTURE2D = 56,
+  LICOMPTYPE_COUNT = 57
 #else
   LICOMPTYPE_COUNT = 55
 #endif

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

@@ -407,6 +407,10 @@ clang::CXXRecordDecl *
 DeclareVkBufferPointerType(clang::ASTContext &context,
                            clang::DeclContext *declContext);
 
+clang::CXXRecordDecl *DeclareVkSampledTextureType(
+    clang::ASTContext &context, clang::DeclContext *declContext,
+    llvm::StringRef hlslTypeName, clang::QualType defaultParamType);
+
 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

@@ -287,6 +287,10 @@ class SpirvBuilder {
   /// If compareVal is given a non-zero value, *Dref* variants of OpImageSample*
   /// will be generated.
   ///
+  /// If sampler is set, it defines the sampler along *image* to create the
+  /// combined image sampler. Otherwise, the *image* parameter must point to a
+  /// sampled image.
+  ///
   /// If lod or grad is given a non-zero value, *ExplicitLod variants of
   /// OpImageSample* will be generated; otherwise, *ImplicitLod variant will
   /// be generated.
@@ -335,6 +339,10 @@ class SpirvBuilder {
 
   /// \brief Creates SPIR-V instructions for gathering the given image.
   ///
+  /// If the of `image` is a sampled image, then that image will be gathered.
+  /// In this case, `sampler` must be `nullptr`. If `image` is not a sampled
+  /// image, a sampled image will be created by combining `image` and `sampler`.
+  ///
   /// 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

@@ -1372,6 +1372,26 @@ CXXRecordDecl *hlsl::DeclareNodeOrRecordType(
 }
 
 #ifdef ENABLE_SPIRV_CODEGEN
+CXXRecordDecl *hlsl::DeclareVkSampledTextureType(ASTContext &context,
+                                                 DeclContext *declContext,
+                                                 llvm::StringRef hlslTypeName,
+                                                 QualType defaultParamType) {
+  // TODO(https://github.com/microsoft/DirectXShaderCompiler/issues/7979): Later
+  // generalize these to all SampledTexture types.
+  BuiltinTypeDeclBuilder Builder(declContext, hlslTypeName,
+                                 TagDecl::TagKind::TTK_Struct);
+
+  TemplateTypeParmDecl *TyParamDecl =
+      Builder.addTypeTemplateParam("SampledTextureType", defaultParamType);
+
+  Builder.startDefinition();
+
+  QualType paramType = QualType(TyParamDecl->getTypeForDecl(), 0);
+  CXXRecordDecl *recordDecl = Builder.getRecordDecl();
+
+  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 +849,23 @@ 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);
+
+    // Bool does not have a defined size in SPIR-V, so it cannot be
+    // used in the external interface.
+    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;
 }
@@ -892,7 +909,8 @@ LowerTypeVisitor::lowerResourceType(QualType type, SpirvLayoutRule rule,
       auto loweredType =
           lowerType(getElementType(astContext, sampledType), rule,
                     /*isRowMajor*/ llvm::None, srcLoc);
-      // Treat bool textures as uint for compatibility with OpTypeImage.
+      // Bool does not have a defined size in SPIR-V, so it cannot be
+      // used in the external interface.
       if (loweredType == spvContext.getBoolType()) {
         loweredType = spvContext.getUIntType(32);
       }

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;
+  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(