diff --git a/include/llvm/ADT/APFloat.h b/include/llvm/ADT/APFloat.h
index d38d8319eee..4d7e7ae11e8 100644
--- a/include/llvm/ADT/APFloat.h
+++ b/include/llvm/ADT/APFloat.h
@@ -173,6 +173,7 @@ namespace llvm {
     };
 
     // Constructors.
+    APFloat(const fltSemantics &); // Default construct to 0.0
     APFloat(const fltSemantics &, const StringRef &);
     APFloat(const fltSemantics &, integerPart);
     APFloat(const fltSemantics &, fltCategory, bool negative, unsigned type=0);
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp
index d50e4e56018..bcf3d6d0125 100644
--- a/lib/Support/APFloat.cpp
+++ b/lib/Support/APFloat.cpp
@@ -692,6 +692,14 @@ APFloat::APFloat(const fltSemantics &ourSemantics, integerPart value)
   normalize(rmNearestTiesToEven, lfExactlyZero);
 }
 
+APFloat::APFloat(const fltSemantics &ourSemantics) {
+  assertArithmeticOK(ourSemantics);
+  initialize(&ourSemantics);
+  category = fcZero;
+  sign = false;
+}
+
+
 APFloat::APFloat(const fltSemantics &ourSemantics,
                  fltCategory ourCategory, bool negative, unsigned type)
 {