diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index dbe8125..29ed68a 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -1060,6 +1060,26 @@
   llvm_unreachable("unhandled");
 }
 
+bool
+Intrinsic::matchIntrinsicVarArg(bool isVarArg,
+                                ArrayRef<Intrinsic::IITDescriptor> &Infos) {
+  // If there are no descriptors left, then it can't be a vararg.
+  if (Infos.empty())
+    return isVarArg;
+
+  // There should be only one descriptor remaining at this point.
+  if (Infos.size() != 1)
+    return true;
+
+  // Check and verify the descriptor.
+  IITDescriptor D = Infos.front();
+  Infos = Infos.slice(1);
+  if (D.Kind == IITDescriptor::VarArg)
+    return !isVarArg;
+
+  return true;
+}
+
 /// hasAddressTaken - returns true if there are any uses of this function
 /// other than direct calls or invokes to it.
 bool Function::hasAddressTaken(const User* *PutOffender) const {