diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -817,8 +817,10 @@
           CurFn->getName().bytes_begin(), CurFn->getName().bytes_end());
       auto Group = crc32(FuncName) % FuncGroups;
       if (Group != CGM.getCodeGenOpts().XRaySelectedFunctionGroup &&
-          !AlwaysXRayAttr)
+          !AlwaysXRayAttr) {
+        Fn->removeFnAttr("xray-instruction-threshold");
         Fn->addFnAttr("function-instrument", "xray-never");
+      }
     }
   }
 
diff --git a/llvm/lib/CodeGen/XRayInstrumentation.cpp b/llvm/lib/CodeGen/XRayInstrumentation.cpp
--- a/llvm/lib/CodeGen/XRayInstrumentation.cpp
+++ b/llvm/lib/CodeGen/XRayInstrumentation.cpp
@@ -145,6 +145,10 @@
 bool XRayInstrumentation::runOnMachineFunction(MachineFunction &MF) {
   auto &F = MF.getFunction();
   auto InstrAttr = F.getFnAttribute("function-instrument");
+  bool NeverInstrument = InstrAttr.isStringAttribute() &&
+                         InstrAttr.getValueAsString() == "xray-never";
+  if (NeverInstrument)
+    return false;
   bool AlwaysInstrument = InstrAttr.isStringAttribute() &&
                           InstrAttr.getValueAsString() == "xray-always";
   auto ThresholdAttr = F.getFnAttribute("xray-instruction-threshold");