diff --git a/tools/clang/lib/AST/ASTContextHLSL.cpp b/tools/clang/lib/AST/ASTContextHLSL.cpp
index dcd3e89e9a..3748f8f8f8 100644
--- a/tools/clang/lib/AST/ASTContextHLSL.cpp
+++ b/tools/clang/lib/AST/ASTContextHLSL.cpp
@@ -699,6 +699,10 @@ void hlsl::AddRaytracingConstants(ASTContext &context) {
   AddConstUInt(
       context, StringRef("RAYTRACING_PIPELINE_FLAG_SKIP_PROCEDURAL_PRIMITIVES"),
       (unsigned)DXIL::RaytracingPipelineFlags::SkipProceduralPrimitives);
+  AddConstUInt(context, context.getTranslationUnitDecl(),
+               StringRef("RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS"),
+               (unsigned)DXIL::RaytracingPipelineFlags::AllowOpacityMicromaps,
+               ConstructAvailabilityAttribute(context, VT69));
 }
 
 /// <summary> Adds all constants and enums for sampler feedback </summary>
diff --git a/tools/clang/lib/Sema/SemaHLSLDiagnoseTU.cpp b/tools/clang/lib/Sema/SemaHLSLDiagnoseTU.cpp
index ed727af149..c562ee8d52 100644
--- a/tools/clang/lib/Sema/SemaHLSLDiagnoseTU.cpp
+++ b/tools/clang/lib/Sema/SemaHLSLDiagnoseTU.cpp
@@ -301,7 +301,8 @@ std::vector<FunctionDecl *> GetAllExportedFDecls(clang::Sema *self) {
 }
 
 void GatherGlobalsWithInitializers(
-    DeclContext *DC, llvm::SmallVectorImpl<VarDecl *> &GlobalsWithInit) {
+    DeclContext *DC, llvm::SmallVectorImpl<VarDecl *> &GlobalsWithInit,
+    llvm::SmallVectorImpl<VarDecl *> &SubObjects) {
   for (auto *D : DC->decls()) {
     // Skip built-ins and function decls.
     if (D->isImplicit() || isa<FunctionDecl>(D))
@@ -310,11 +311,19 @@ void GatherGlobalsWithInitializers(
       // Add if user-defined static or groupshared global with initializer.
       if (VD->hasInit() && VD->hasGlobalStorage() &&
           (VD->getStorageClass() == SC_Static ||
-           VD->hasAttr<HLSLGroupSharedAttr>()))
+           VD->hasAttr<HLSLGroupSharedAttr>())) {
+        // Place subobjects in a separate collection.
+        if (const RecordType *RT = VD->getType()->getAs<RecordType>()) {
+          if (RT->getDecl()->hasAttr<HLSLSubObjectAttr>()) {
+            SubObjects.push_back(VD);
+            continue;
+          }
+        }
         GlobalsWithInit.push_back(VD);
+      }
     } else if (auto *DC = dyn_cast<DeclContext>(D)) {
       // Recurse into DeclContexts like namespace, cbuffer, class/struct, etc.
-      GatherGlobalsWithInitializers(DC, GlobalsWithInit);
+      GatherGlobalsWithInitializers(DC, GlobalsWithInit, SubObjects);
     }
   }
 }
@@ -592,14 +601,24 @@ void hlsl::DiagnoseTranslationUnit(clang::Sema *self) {
       hlsl::ShaderModel::GetByName(self->getLangOpts().HLSLProfile.c_str());
 
   llvm::SmallVector<VarDecl *, 16> GlobalsWithInit;
-  GatherGlobalsWithInitializers(self->getASTContext().getTranslationUnitDecl(),
-                                GlobalsWithInit);
-
+  llvm::SmallVector<VarDecl *, 16> SubObjects;
   std::set<FunctionDecl *> DiagnosedRecursiveDecls;
   llvm::SmallPtrSet<CallExpr *, 16> DiagnosedCalls;
   llvm::SmallPtrSet<DeclRefExpr *, 16> DeclAvailabilityChecked;
   llvm::SmallSet<SourceLocation, 16> DiagnosedTypeLocs;
 
+  GatherGlobalsWithInitializers(self->getASTContext().getTranslationUnitDecl(),
+                                GlobalsWithInit, SubObjects);
+
+  if (shaderModel->GetKind() == DXIL::ShaderKind::Library) {
+    DXIL::NodeLaunchType NodeLaunchTy = DXIL::NodeLaunchType::Invalid;
+    HLSLReachableDiagnoseVisitor Visitor(
+        self, shaderModel, shaderModel->GetKind(), NodeLaunchTy, nullptr,
+        DiagnosedCalls, DeclAvailabilityChecked, DiagnosedTypeLocs);
+    for (VarDecl *VD : SubObjects)
+      Visitor.TraverseDecl(VD);
+  }
+
   // for each FDecl, check for recursion
   for (FunctionDecl *FDecl : FDeclsToCheck) {
     CallGraphWithRecurseGuard callGraph;
@@ -705,7 +724,6 @@ void hlsl::DiagnoseTranslationUnit(clang::Sema *self) {
             << PatchConstantFunctionReturnIdx;
       }
     }
-
     DXIL::ShaderKind EntrySK = shaderModel->GetKind();
     DXIL::NodeLaunchType NodeLaunchTy = DXIL::NodeLaunchType::Invalid;
     if (EntrySK == DXIL::ShaderKind::Library) {
diff --git a/tools/clang/test/HLSLFileCheck/d3dreflect/raytracingpipelineconfig1.hlsl b/tools/clang/test/HLSLFileCheck/d3dreflect/raytracingpipelineconfig1.hlsl
new file mode 100644
index 0000000000..44424f5d14
--- /dev/null
+++ b/tools/clang/test/HLSLFileCheck/d3dreflect/raytracingpipelineconfig1.hlsl
@@ -0,0 +1,19 @@
+// RUN: %dxilver 1.9 | %dxc -T lib_6_9  %s | FileCheck %s
+// RUN: %dxilver 1.9 | %dxc -T lib_6_9 -ast-dump %s | FileCheck -check-prefix=AST %s
+// RUN: %dxilver 1.9 | %dxc -T lib_6_9 -ast-dump-implicit %s | FileCheck -check-prefix=ASTIMPL %s
+
+
+// CHECK: ; RaytracingPipelineConfig1 rpc = { MaxTraceRecursionDepth = 32, Flags = RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS };
+
+// AST: TranslationUnitDecl 0x{{.+}} <<invalid sloc>> <invalid sloc>
+// AST-NEXT: VarDecl 0x{{.+}} rpc 'RaytracingPipelineConfig1' static cinit
+// AST-NEXT: InitListExpr 0x{{.+}} 'RaytracingPipelineConfig1'
+// AST-NEXT: ImplicitCastExpr 0x{{.+}} 'unsigned int' <IntegralCast>
+// AST-NEXT: IntegerLiteral 0x{{.+}} 'literal int' 32
+// AST-NEXT: ImplicitCastExpr 0x{{.+}} 'unsigned int' <LValueToRValue>
+// AST-NEXT: DeclRefExpr 0x{{.+}} 'const unsigned int' lvalue Var 0x{{.+}} 'RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS' 'const unsigned int'
+// ASTIMPL: VarDecl 0x{{.+}} <<invalid sloc>> <invalid sloc> implicit referenced RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS 'const unsigned int' static cinit
+// ASTIMPL-NEXT: IntegerLiteral 0x{{.+}} <<invalid sloc>> 'const unsigned int' 1024
+// ASTIMPL-NEXT: AvailabilityAttr 0x{{.+}} <<invalid sloc>> Implicit  6.9 0 0 ""
+
+RaytracingPipelineConfig1 rpc = { 32, RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS };
diff --git a/tools/clang/test/SemaHLSL/raytracingpipelineconfig1-warnings.hlsl b/tools/clang/test/SemaHLSL/raytracingpipelineconfig1-warnings.hlsl
new file mode 100644
index 0000000000..c220f5734d
--- /dev/null
+++ b/tools/clang/test/SemaHLSL/raytracingpipelineconfig1-warnings.hlsl
@@ -0,0 +1,6 @@
+// RUN: %dxc -T lib_6_8 -verify %s
+
+// expected-warning@+1{{potential misuse of built-in constant 'RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS' in shader model lib_6_8; introduced in shader model 6.9}} 
+RaytracingPipelineConfig1 rpc = { 32, RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS };
+
+
diff --git a/tools/clang/tools/dxcompiler/dxcdisassembler.cpp b/tools/clang/tools/dxcompiler/dxcdisassembler.cpp
index 01f4973fbe..3af305d52a 100644
--- a/tools/clang/tools/dxcompiler/dxcdisassembler.cpp
+++ b/tools/clang/tools/dxcompiler/dxcdisassembler.cpp
@@ -671,6 +671,8 @@ static const char *FlagToString(DXIL::RaytracingPipelineFlags Flag) {
     return "RAYTRACING_PIPELINE_FLAG_SKIP_TRIANGLES";
   case DXIL::RaytracingPipelineFlags::SkipProceduralPrimitives:
     return "RAYTRACING_PIPELINE_FLAG_SKIP_PROCEDURAL_PRIMITIVES";
+  case DXIL::RaytracingPipelineFlags::AllowOpacityMicromaps:
+    return "RAYTRACING_PIPELINE_FLAG_ALLOW_OPACITY_MICROMAPS";
   }
   return "<invalid RaytracingPipelineFlags>";
 }