diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h
index d8ed2224985..41019899766 100644
--- a/include/llvm/ADT/APInt.h
+++ b/include/llvm/ADT/APInt.h
@@ -842,7 +842,11 @@ public:
 
   /// @returns the bit value at bitPosition
   /// @brief Array-indexing support.
-  bool operator[](unsigned bitPosition) const;
+  bool operator[](unsigned bitPosition) const {
+    assert(bitPosition < getBitWidth() && "Bit position out of bounds!");
+    return (maskBit(bitPosition) &
+            (isSingleWord() ? VAL : pVal[whichWord(bitPosition)])) != 0;
+  }
 
   /// @}
   /// @name Comparison Operators
diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index c5713a0eb17..9b81fe776a6 100644
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -484,12 +484,6 @@ APInt APInt::operator-(const APInt& RHS) const {
   return Result.clearUnusedBits();
 }
 
-bool APInt::operator[](unsigned bitPosition) const {
-  assert(bitPosition < getBitWidth() && "Bit position out of bounds!");
-  return (maskBit(bitPosition) &
-          (isSingleWord() ?  VAL : pVal[whichWord(bitPosition)])) != 0;
-}
-
 bool APInt::EqualSlowCase(const APInt& RHS) const {
   // Get some facts about the number of bits used in the two operands.
   unsigned n1 = getActiveBits();