[spirv] add `vk::ext_result_id<T>` type (#4192)

As a part of HLSL version of GL_EXT_spirv_intrinsics, this commit adds
vk::ext_result_id<T> type. We must use it for a variable definition or
a function parameter. It means we do not consider it as a physical
storage. Instead, it will be a result id of the instruction.

Related to #3919

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

@@ -338,6 +338,13 @@ clang::CXXRecordDecl* DeclareTemplateTypeWithHandle(
             uint8_t templateArgCount,
   _In_opt_  clang::TypeSourceInfo* defaultTypeArgValue);
 
+clang::CXXRecordDecl* DeclareTemplateTypeWithHandleInDeclContext(
+            clang::ASTContext& context,
+            clang::DeclContext *declContext,
+            llvm::StringRef name,
+            uint8_t templateArgCount,
+  _In_opt_  clang::TypeSourceInfo* defaultTypeArgValue);
+
 clang::CXXRecordDecl* DeclareUIntTemplatedTypeWithHandle(
   clang::ASTContext& context, llvm::StringRef typeName, llvm::StringRef templateParamName);
 clang::CXXRecordDecl *DeclareUIntTemplatedTypeWithHandleInDeclContext(
@@ -404,6 +411,7 @@ bool IsHLSLAggregateType(clang::QualType type);
 clang::QualType GetHLSLResourceResultType(clang::QualType type);
 unsigned GetHLSLResourceTemplateUInt(clang::QualType type);
 bool IsIncompleteHLSLResourceArrayType(clang::ASTContext& context, clang::QualType type);
+clang::QualType GetHLSLResourceTemplateParamType(clang::QualType type);
 clang::QualType GetHLSLInputPatchElementType(clang::QualType type);
 unsigned GetHLSLInputPatchCount(clang::QualType type);
 clang::QualType GetHLSLOutputPatchElementType(clang::QualType type);

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

@@ -324,10 +324,16 @@ bool isOrContainsNonFpColMajorMatrix(const ASTContext &,
                                      const SpirvCodeGenOptions &, QualType type,
                                      const Decl *decl);
 
-/// \bried Returns true if the given type is a String or StringLiteral type.
+/// \brief Returns true if the given type is `vk::ext_result_id<T>`.
+bool isExtResultIdType(QualType type);
+
+/// \brief Returns true if the given type is defined in `vk` namespace.
+bool isTypeInVkNamespace(const RecordType *type);
+
+/// \brief Returns true if the given type is a String or StringLiteral type.
 bool isStringType(QualType);
 
-/// \bried Returns true if the given type is a bindless array of an opaque type.
+/// \brief Returns true if the given type is a bindless array of an opaque type.
 bool isBindlessOpaqueArray(QualType type);
 
 /// \brief Generates the corresponding SPIR-V vector type for the given Clang

tools/clang/lib/AST/ASTContextHLSL.cpp

@@ -665,6 +665,20 @@ CXXRecordDecl* hlsl::DeclareTemplateTypeWithHandle(
   StringRef name,
   uint8_t templateArgCount, 
   _In_opt_ TypeSourceInfo* defaultTypeArgValue)
+{
+  return DeclareTemplateTypeWithHandleInDeclContext(context,
+                                                    context.getTranslationUnitDecl(),
+                                                    name,
+                                                    templateArgCount,
+                                                    defaultTypeArgValue);
+}
+
+CXXRecordDecl* hlsl::DeclareTemplateTypeWithHandleInDeclContext(
+  ASTContext& context,
+  DeclContext *declContext,
+  StringRef name,
+  uint8_t templateArgCount,
+  _In_opt_ TypeSourceInfo* defaultTypeArgValue)
 {
   DXASSERT(templateArgCount != 0, "otherwise caller should be creating a class or struct");
   DXASSERT(templateArgCount <= 2, "otherwise the function needs to be updated for a different template pattern");
@@ -672,7 +686,7 @@ CXXRecordDecl* hlsl::DeclareTemplateTypeWithHandle(
   // Create an object template declaration in translation unit scope.
   // templateArgCount=1: template<typename element> typeName { ... }
   // templateArgCount=2: template<typename element, int count> typeName { ... }
-  BuiltinTypeDeclBuilder typeDeclBuilder(context.getTranslationUnitDecl(), name);
+  BuiltinTypeDeclBuilder typeDeclBuilder(declContext, name);
   TemplateTypeParmDecl* elementTemplateParamDecl = typeDeclBuilder.addTypeTemplateParam("element", defaultTypeArgValue);
   NonTypeTemplateParmDecl* countTemplateParamDecl = nullptr;
   if (templateArgCount > 1)

tools/clang/lib/AST/HlslTypes.cpp

@@ -729,7 +729,8 @@ bool IsIncompleteHLSLResourceArrayType(clang::ASTContext &context,
   }
   return false;
 }
-QualType GetHLSLInputPatchElementType(QualType type) {
+
+QualType GetHLSLResourceTemplateParamType(QualType type) {
   type = type.getCanonicalType();
   const RecordType *RT = cast<RecordType>(type);
   const ClassTemplateSpecializationDecl *templateDecl =
@@ -737,6 +738,10 @@ QualType GetHLSLInputPatchElementType(QualType type) {
   const TemplateArgumentList &argList = templateDecl->getTemplateArgs();
   return argList[0].getAsType();
 }
+
+QualType GetHLSLInputPatchElementType(QualType type) {
+  return GetHLSLResourceTemplateParamType(type);
+}
 unsigned GetHLSLInputPatchCount(QualType type) {
   type = type.getCanonicalType();
   const RecordType *RT = cast<RecordType>(type);
@@ -746,12 +751,7 @@ unsigned GetHLSLInputPatchCount(QualType type) {
   return argList[1].getAsIntegral().getLimitedValue();
 }
 clang::QualType GetHLSLOutputPatchElementType(QualType type) {
-  type = type.getCanonicalType();
-  const RecordType *RT = cast<RecordType>(type);
-  const ClassTemplateSpecializationDecl *templateDecl =
-      cast<ClassTemplateSpecializationDecl>(RT->getAsCXXRecordDecl());
-  const TemplateArgumentList &argList = templateDecl->getTemplateArgs();
-  return argList[0].getAsType();
+  return GetHLSLResourceTemplateParamType(type);
 }
 unsigned GetHLSLOutputPatchCount(QualType type) {
   type = type.getCanonicalType();

tools/clang/lib/SPIRV/AstTypeProbe.cpp

@@ -1254,6 +1254,25 @@ bool isOrContainsNonFpColMajorMatrix(const ASTContext &astContext,
   return false;
 }
 
+bool isTypeInVkNamespace(const RecordType *type) {
+  if (const auto *nameSpaceDecl =
+          dyn_cast<NamespaceDecl>(type->getDecl()->getDeclContext())) {
+    return nameSpaceDecl->getName() == "vk";
+  }
+  return false;
+}
+
+bool isExtResultIdType(QualType type) {
+  if (const auto *elaboratedType = type->getAs<ElaboratedType>()) {
+    if (const auto *recordType = elaboratedType->getAs<RecordType>()) {
+      if (!isTypeInVkNamespace(recordType))
+        return false;
+      return recordType->getDecl()->getName() == "ext_result_id";
+    }
+  }
+  return false;
+}
+
 bool isStringType(QualType type) {
   return hlsl::IsStringType(type) || hlsl::IsStringLiteralType(type);
 }

tools/clang/lib/SPIRV/DeclResultIdMapper.cpp

@@ -1054,6 +1054,21 @@ SpirvVariable *DeclResultIdMapper::createExternVar(const VarDecl *var) {
   return varInstr;
 }
 
+SpirvInstruction *DeclResultIdMapper::createResultId(const VarDecl *var) {
+  assert(isExtResultIdType(var->getType()));
+
+  // Without initialization, we cannot generate the result id.
+  if (!var->hasInit()) {
+    emitError("Found uninitialized variable for result id.",
+              var->getLocation());
+    return nullptr;
+  }
+
+  SpirvInstruction *init = theEmitter.doExpr(var->getInit());
+  astDecls[var] = createDeclSpirvInfo(init);
+  return init;
+}
+
 SpirvInstruction *
 DeclResultIdMapper::createOrUpdateStringVar(const VarDecl *var) {
   assert(hlsl::IsStringType(var->getType()) ||

tools/clang/lib/SPIRV/DeclResultIdMapper.h

@@ -392,6 +392,14 @@ public:
   /// for it.
   SpirvInstruction *createOrUpdateStringVar(const VarDecl *);
 
+  /// \brief Returns an instruction that represents the given VarDecl.
+  /// VarDecl must be a variable of vk::ext_result_id<Type> type.
+  ///
+  /// This function inspects the VarDecl for an initialization expression. If
+  /// initialization expression is not found, it will emit an error because the
+  /// variable with result id requires an initialization.
+  SpirvInstruction *createResultId(const VarDecl *var);
+
   /// \brief Creates an Enum constant.
   void createEnumConstant(const EnumConstantDecl *decl);
 

tools/clang/lib/SPIRV/LowerTypeVisitor.cpp

@@ -521,6 +521,22 @@ const SpirvType *LowerTypeVisitor::lowerType(QualType type,
   return 0;
 }
 
+const SpirvType *
+LowerTypeVisitor::lowerVkTypeInVkNamespace(QualType type, llvm::StringRef name,
+                                           SpirvLayoutRule rule,
+                                           SourceLocation srcLoc) {
+  if (name == "ext_type") {
+    auto typeId = hlsl::GetHLSLResourceTemplateUInt(type);
+    return spvContext.getCreatedSpirvIntrinsicType(typeId);
+  }
+  if (name == "ext_result_id") {
+    QualType realType = hlsl::GetHLSLResourceTemplateParamType(type);
+    return lowerType(realType, rule, llvm::None, srcLoc);
+  }
+  emitError("unknown type %0 in vk namespace", srcLoc) << type;
+  return nullptr;
+}
+
 const SpirvType *LowerTypeVisitor::lowerResourceType(QualType type,
                                                      SpirvLayoutRule rule,
                                                      SourceLocation srcLoc) {
@@ -535,6 +551,10 @@ const SpirvType *LowerTypeVisitor::lowerResourceType(QualType type,
   assert(recordType);
   const llvm::StringRef name = recordType->getDecl()->getName();
 
+  if (isTypeInVkNamespace(recordType)) {
+    return lowerVkTypeInVkNamespace(type, name, rule, srcLoc);
+  }
+
   // TODO: avoid string comparison once hlsl::IsHLSLResouceType() does that.
 
   { // Texture types
@@ -593,11 +613,6 @@ const SpirvType *LowerTypeVisitor::lowerResourceType(QualType type,
   if (name == "RayQuery")
     return spvContext.getRayQueryTypeKHR();
 
-  if (name == "ext_type") {
-    auto typeId = hlsl::GetHLSLResourceTemplateUInt(type);
-    return spvContext.getCreatedSpirvIntrinsicType(typeId);
-  }
-
   if (name == "StructuredBuffer" || name == "RWStructuredBuffer" ||
       name == "AppendStructuredBuffer" || name == "ConsumeStructuredBuffer") {
     // StructureBuffer<S> will be translated into an OpTypeStruct with one

tools/clang/lib/SPIRV/LowerTypeVisitor.h

@@ -71,6 +71,11 @@ private:
   const SpirvType *lowerResourceType(QualType type, SpirvLayoutRule rule,
                                      SourceLocation);
 
+  /// Lowers the given type defined in vk namespace into its SPIR-V type.
+  const SpirvType *lowerVkTypeInVkNamespace(QualType type, llvm::StringRef name,
+                                            SpirvLayoutRule rule,
+                                            SourceLocation srcLoc);
+
   /// For the given sampled type, returns the corresponding image format
   /// that can be used to create an image object.
   spv::ImageFormat translateSampledTypeToImageFormat(QualType sampledType,

tools/clang/lib/SPIRV/SpirvEmitter.cpp

@@ -1530,6 +1530,11 @@ void SpirvEmitter::doVarDecl(const VarDecl *decl) {
   const auto loc = decl->getLocation();
   const auto range = decl->getSourceRange();
 
+  if (isExtResultIdType(decl->getType())) {
+    declIdMapper.createResultId(decl);
+    return;
+  }
+
   // HLSL has the 'string' type which can be used for rare purposes such as
   // printf (SPIR-V's DebugPrintf). SPIR-V does not have a 'char' or 'string'
   // type, and therefore any variable of such type should not be created.

tools/clang/lib/Sema/SemaHLSL.cpp

@@ -184,6 +184,7 @@ enum ArBasicKind {
   AR_OBJECT_VK_SUBPASS_INPUT,
   AR_OBJECT_VK_SUBPASS_INPUT_MS,
   AR_OBJECT_VK_SPV_INTRINSIC_TYPE,
+  AR_OBJECT_VK_SPV_INTRINSIC_RESULT_ID,
 #endif // ENABLE_SPIRV_CODEGEN
   // SPIRV change ends
 
@@ -476,6 +477,7 @@ const UINT g_uBasicKindProps[] =
   BPROP_OBJECT | BPROP_RBUFFER,   // AR_OBJECT_VK_SUBPASS_INPUT
   BPROP_OBJECT | BPROP_RBUFFER,   // AR_OBJECT_VK_SUBPASS_INPUT_MS
   BPROP_OBJECT,                   // AR_OBJECT_VK_SPV_INTRINSIC_TYPE use recordType
+  BPROP_OBJECT,                   // AR_OBJECT_VK_SPV_INTRINSIC_RESULT_ID use recordType
 #endif // ENABLE_SPIRV_CODEGEN
   // SPIRV change ends
 
@@ -1400,6 +1402,7 @@ const ArBasicKind g_ArBasicKindsAsTypes[] =
   AR_OBJECT_VK_SUBPASS_INPUT,
   AR_OBJECT_VK_SUBPASS_INPUT_MS,
   AR_OBJECT_VK_SPV_INTRINSIC_TYPE,
+  AR_OBJECT_VK_SPV_INTRINSIC_RESULT_ID,
 #endif // ENABLE_SPIRV_CODEGEN
   // SPIRV change ends
 
@@ -1493,6 +1496,7 @@ const uint8_t g_ArBasicKindsTemplateCount[] =
   1, // AR_OBJECT_VK_SUBPASS_INPUT
   1, // AR_OBJECT_VK_SUBPASS_INPUT_MS,
   1, // AR_OBJECT_VK_SPV_INTRINSIC_TYPE
+  1, // AR_OBJECT_VK_SPV_INTRINSIC_RESULT_ID
 #endif // ENABLE_SPIRV_CODEGEN
   // SPIRV change ends
 
@@ -1594,6 +1598,7 @@ const SubscriptOperatorRecord g_ArBasicKindsSubscripts[] =
   { 0, MipsFalse, SampleFalse }, // AR_OBJECT_VK_SUBPASS_INPUT (SubpassInput)
   { 0, MipsFalse, SampleFalse }, // AR_OBJECT_VK_SUBPASS_INPUT_MS (SubpassInputMS)
   { 0, MipsFalse, SampleFalse }, // AR_OBJECT_VK_SPV_INTRINSIC_TYPE
+  { 0, MipsFalse, SampleFalse }, // AR_OBJECT_VK_SPV_INTRINSIC_RESULT_ID
 #endif // ENABLE_SPIRV_CODEGEN
   // SPIRV change ends
 
@@ -1714,6 +1719,7 @@ const char* g_ArBasicTypeNames[] =
   "SubpassInput",
   "SubpassInputMS",
   "ext_type",
+  "ext_result_id",
 #endif // ENABLE_SPIRV_CODEGEN
   // SPIRV change ends
 
@@ -3602,6 +3608,13 @@ private:
             *m_context, m_vkNSDecl, typeName, "id");
         recordDecl->setImplicit(true);
       }
+      else if (kind == AR_OBJECT_VK_SPV_INTRINSIC_RESULT_ID && m_vkNSDecl) {
+        recordDecl = DeclareTemplateTypeWithHandleInDeclContext(*m_context,
+                                                                m_vkNSDecl,
+                                                                typeName, 1,
+                                                                nullptr);
+        recordDecl->setImplicit(true);
+      }
 #endif
       else if (templateArgCount == 0) {
         recordDecl = DeclareRecordTypeWithHandle(*m_context, typeName);
@@ -12924,7 +12937,8 @@ bool Sema::DiagnoseHLSLDecl(Declarator &D, DeclContext *DC, Expr *BitWidth,
   if (!getLangOpts().SPIRV) {
     if (basicKind == ArBasicKind::AR_OBJECT_VK_SUBPASS_INPUT ||
         basicKind == ArBasicKind::AR_OBJECT_VK_SUBPASS_INPUT_MS ||
-        basicKind == ArBasicKind::AR_OBJECT_VK_SPV_INTRINSIC_TYPE) {
+        basicKind == ArBasicKind::AR_OBJECT_VK_SPV_INTRINSIC_TYPE ||
+        basicKind == ArBasicKind::AR_OBJECT_VK_SPV_INTRINSIC_RESULT_ID) {
       Diag(D.getLocStart(), diag::err_hlsl_vulkan_specific_feature)
           << g_ArBasicTypeNames[basicKind];
       result = false;

tools/clang/test/CodeGenSPIRV/spv.intrinsic.result_id.hlsl

@@ -0,0 +1,20 @@
+// RUN: %dxc -T cs_6_0 -E main
+
+[[vk::ext_instruction(/* OpLoad */ 61)]]
+vk::ext_result_id<float> load([[vk::ext_reference]] float pointer,
+                              [[vk::ext_literal]] int memoryOperands);
+
+[[vk::ext_instruction(/* OpStore */ 62)]]
+void store([[vk::ext_reference]] float pointer,
+           vk::ext_result_id<float> value,
+           [[vk::ext_literal]] int memoryOperands);
+
+[numthreads(1,1,1)]
+void main() {
+  float foo, bar;
+
+//CHECK: [[foo_value:%\w+]] = OpLoad %float %foo None
+//CHECK:                      OpStore %bar [[foo_value]] Volatile
+  vk::ext_result_id<float> foo_value = load(foo, /* None */ 0x0);
+  store(bar, foo_value, /* Volatile */ 0x1);
+}

tools/clang/unittests/SPIRV/CodeGenSpirvTest.cpp

@@ -1341,6 +1341,7 @@ TEST_F(FileTest, IntrinsicsVkQueueFamilyScope) {
 }
 TEST_F(FileTest, IntrinsicsSpirv) {
   runFileTest("spv.intrinsicInstruction.hlsl");
+  runFileTest("spv.intrinsic.result_id.hlsl");
   runFileTest("spv.intrinsicLiteral.hlsl");
   runFileTest("spv.intrinsicDecorate.hlsl", Expect::Success, false);
   runFileTest("spv.intrinsicExecutionMode.hlsl", Expect::Success, false);