DLABAD (3lapack)

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

PURPOSE

  DLABAD 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.