diff --git a/clang/include/clang/Basic/FixedPoint.h b/clang/include/clang/Basic/FixedPoint.h
--- a/clang/include/clang/Basic/FixedPoint.h
+++ b/clang/include/clang/Basic/FixedPoint.h
@@ -75,11 +75,11 @@
   }
 
 private:
-  unsigned Width;
-  unsigned Scale;
-  bool IsSigned;
-  bool IsSaturated;
-  bool HasUnsignedPadding;
+  unsigned Width          : 16;
+  unsigned Scale          : 13;
+  unsigned IsSigned       : 1;
+  unsigned IsSaturated    : 1;
+  unsigned HasUnsignedPadding : 1;
 };
 
 /// The APFixedPoint class works similarly to APInt/APSInt in that it is a