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+ SUBROUTINE DLABAD( SMALL, LARGE )
+*
+* -- LAPACK auxiliary routine (version 3.1) --
+* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
+* November 2006
+*
+* .. Scalar Arguments ..
+ 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
+* 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.
+*
+* =====================================================================
+*
+* .. Intrinsic Functions ..
+ INTRINSIC LOG10, SQRT
+* ..
+* .. Executable Statements ..
+*
+* If it looks like we're on a Cray, take the square root of
+* SMALL and LARGE to avoid overflow and underflow problems.
+*
+ IF( LOG10( LARGE ).GT.2000.D0 ) THEN
+ SMALL = SQRT( SMALL )
+ LARGE = SQRT( LARGE )
+ END IF
+*
+ RETURN
+*
+* End of DLABAD
+*
+ END