diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
--- a/clang/lib/CodeGen/CGExprConstant.cpp
+++ b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -1122,9 +1122,10 @@
     }
 
     case CK_AtomicToNonAtomic:
-    case CK_NonAtomicToAtomic:
-    case CK_NoOp:
     case CK_ConstructorConversion:
+    case CK_FunctionToPointerDecay:
+    case CK_NoOp:
+    case CK_NonAtomicToAtomic:
       return Visit(subExpr, destType);
 
     case CK_ArrayToPointerDecay:
@@ -1189,7 +1190,6 @@
     case CK_CPointerToObjCPointerCast:
     case CK_BlockPointerToObjCPointerCast:
     case CK_AnyPointerToBlockPointerCast:
-    case CK_FunctionToPointerDecay:
     case CK_BaseToDerived:
     case CK_DerivedToBase:
     case CK_UncheckedDerivedToBase:
@@ -1241,6 +1241,26 @@
     return llvm::ConstantInt::get(CGM.getLLVMContext(), I->getValue());
   }
 
+  llvm::Constant *VisitDeclRefExpr(DeclRefExpr *D, QualType T) {
+    //llvm::dbgs() << __func__ << "\n";
+    //D->dump();
+    //VD->dump();
+    ValueDecl *VD = D->getDecl();
+    if (isa<FunctionDecl>(VD)) {
+      return CGM.getModule().getNamedValue(VD->getName());
+      //llvm::Module &M = CGM.getModule();
+      //llvm::GlobalValue *GV = M.getNamedValue(VD->getName());
+      //return GV;
+    }
+    //D->getSubExpr()->dump();
+    //llvm::dbgs() << isa<llvm::Function>(D) << "\n";
+    //llvm::GlobalValue *GV = CGM.getModule().getNamedValue(D->getName());
+    return nullptr;
+    //return nullptr;
+    //llvm::Value *V = Emitter.CGF->EmitDeclRefLValue(D).getPointer(*Emitter.CGF);
+    //return dyn_cast_or_null<llvm::Constant>(V);
+  }
+
   llvm::Constant *EmitArrayInitialization(InitListExpr *ILE, QualType T) {
     auto *CAT = CGM.getContext().getAsConstantArrayType(ILE->getType());
     assert(CAT && "can't emit array init for non-constant-bound array");