floating point underflow

1 definition found

floating point underflow - Free On-line Dictionary of Computing (26 May 2007) :

  underflow
  floating point underflow
  floating underflow
  
     <programming> (or "floating point underflow", "floating
     underflow", after "overflow") A condition that can occur
     when the result of a floating-point operation would be
     smaller in magnitude (closer to zero, either positive or
     negative) than the smallest quantity representable.  Underflow
     is actually (negative) overflow of the exponent of the
     floating point quantity.  For example, an eight-bit twos complement
      exponent can represent multipliers of 2^-128 to
     2^127.  A result less than 2^-128 would cause underflow.
  
     Depending on the processor, the programming language and the
     run-time system, underflow may set a status bit, raise an
     exception or generate a hardware interrupt or some
     combination of these effects.  Alternatively, it may just be
     ignored and zero substituted for the unrepresentable value,
     though this might lead to a later divide by zero error which
     cannot be so easily ignored.
  
     (2006-11-09)