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 subroutine is intended to identify machines
with a large exponent range, such as the Crays, and rede
fine 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.
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