takes as input the values computed by
for underflow and overflow, and returns the square root of each of these values if the log of
is sufficiently large. This
is intended to identify machines with a large exponent range, such as the Crays, and redefine the underflow and overflow limits to be the square roots of the values computed by
is needed because
does not compensate for poor arithmetic in the upper half of the exponent range, as is found on a Cray.