diff --git a/llvm/include/llvm/ADT/APFloat.h b/llvm/include/llvm/ADT/APFloat.h
--- a/llvm/include/llvm/ADT/APFloat.h
+++ b/llvm/include/llvm/ADT/APFloat.h
@@ -1426,6 +1426,8 @@
 const APFloat &DoubleAPFloat::getFirst() const { return Floats[0]; }
 APFloat &DoubleAPFloat::getSecond() { return Floats[1]; }
 const APFloat &DoubleAPFloat::getSecond() const { return Floats[1]; }
+DoubleAPFloat scalbn(const DoubleAPFloat &Arg, int Exp, APFloat::roundingMode RM);
+DoubleAPFloat frexp(const DoubleAPFloat &X, int &Exp, APFloat::roundingMode);
 
 } // namespace detail