man slabad (Fonctions bibliothèques) - take 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
NAME
SLABAD - take 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
SYNOPSIS
- SUBROUTINE SLABAD(
- SMALL, LARGE )
- REAL LARGE, SMALL
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.
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.