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
@@ -249,7 +249,7 @@
   /// \name Constructors
   /// @{
 
-  IEEEFloat(const fltSemantics &); // Default construct to 0.0
+  IEEEFloat(const fltSemantics &); // Default construct to +0.0
   IEEEFloat(const fltSemantics &, integerPart);
   IEEEFloat(const fltSemantics &, uninitializedTag);
   IEEEFloat(const fltSemantics &, const APInt &);
diff --git a/llvm/lib/Support/APFloat.cpp b/llvm/lib/Support/APFloat.cpp
--- a/llvm/lib/Support/APFloat.cpp
+++ b/llvm/lib/Support/APFloat.cpp
@@ -925,8 +925,7 @@
 
 IEEEFloat::IEEEFloat(const fltSemantics &ourSemantics) {
   initialize(&ourSemantics);
-  category = fcZero;
-  sign = false;
+  makeZero(false);
 }
 
 // Delegate to the previous constructor, because later copy constructor may