separate ( Generic_Elementary_Functions )

function Infinity (X : Float_Type) return Float_Type is

   -- This function formally delivers an infinite result with the same
   -- sign as X.  It is called during argument prescreening in some of
   -- the elementary functions when the argument is such that the result
   -- MUST overflow.  This function will cause an overflow to occur,
   -- except when executed in an environment implementing the proposed
   -- IEEE binding for Ada, in which case it will deliver an IEEE infinity
   -- with the correct sign.  It is carefully constructed to avoid some
   -- compiler bugs that have been observed, in which a CONSTANT expression
   -- that must overflow is incorrectly handled by the compiler at compile
   -- time.

   Big        : constant Common_Float := Common_Float'Base'Last;
   Signed_Big : constant Common_Float := Common_Float(Copy_Sign(1.0, X)) * Big;

begin

   return Float_Type((Signed_Big * Big) * Big);

end;