SLABAD
November 2006
Purpose
SLABAD takes as input the values computed by SLAMCH for underflow and
overflow, and returns the square root of each of these values if the
log of LARGE is sufficiently large. This subroutine 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 SLAMCH. This subroutine is needed because
SLAMCH does not compensate for poor arithmetic in the upper half of
the exponent range, as is found on a Cray.
overflow, and returns the square root of each of these values if the
log of LARGE is sufficiently large. This subroutine 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 SLAMCH. This subroutine is needed because
SLAMCH does not compensate for poor arithmetic in the upper half of
the exponent range, as is found on a Cray.
Arguments
| SMALL |
(input/output) REAL
On entry, the underflow threshold as computed by SLAMCH.
On exit, if LOG10(LARGE) is sufficiently large, the square root of SMALL, otherwise unchanged. |
| LARGE |
(input/output) REAL
On entry, the overflow threshold as computed by SLAMCH.
On exit, if LOG10(LARGE) is sufficiently large, the square root of LARGE, otherwise unchanged. |