dlabad(3)
NAME
- DLABAD - take as input the values computed by DLAMCH for
- underflow and overflow, and returns the square root of each of
- these values if the log of LARGE is sufficiently large
SYNOPSIS
SUBROUTINE DLABAD( SMALL, LARGE )
DOUBLE PRECISION LARGE, SMALL
PURPOSE
- DLABAD takes as input the values computed by DLAMCH for
- underflow and overflow, and returns the square root of each of
- these values if the log of LARGE is sufficiently large. This sub
- routine 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 DLAMCH.
- This subroutine is needed because DLAMCH does not compensate for
- poor arithmetic in the upper half of the exponent range, as is
- found on a Cray.
ARGUMENTS
- SMALL (input/output) DOUBLE PRECISION
- On entry, the underflow threshold as computed by
- DLAMCH. On exit, if LOG10(LARGE) is sufficiently large, the
- square root of SMALL, otherwise unchanged.
- LARGE (input/output) DOUBLE PRECISION
- On entry, the overflow threshold as computed by
- DLAMCH. On exit, if LOG10(LARGE) is sufficiently large, the
- square root of LARGE, otherwise unchanged.
- LAPACK version 3.0 15 June 2000