DLABAD(3F)DLABAD(3F)NAMEDLABAD - 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 DLABAD( SMALL, LARGE )
DOUBLE PRECISION LARGE, SMALL
PURPOSEDLABAD 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 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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