--- rpl/lapack/lapack/dlapy3.f	2010/08/06 15:32:27	1.4
+++ rpl/lapack/lapack/dlapy3.f	2023/08/07 08:38:55	1.18
@@ -1,28 +1,79 @@
+*> \brief \b DLAPY3 returns sqrt(x2+y2+z2).
+*
+*  =========== DOCUMENTATION ===========
+*
+* Online html documentation available at
+*            http://www.netlib.org/lapack/explore-html/
+*
+*> \htmlonly
+*> Download DLAPY3 + dependencies
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlapy3.f">
+*> [TGZ]</a>
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlapy3.f">
+*> [ZIP]</a>
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlapy3.f">
+*> [TXT]</a>
+*> \endhtmlonly
+*
+*  Definition:
+*  ===========
+*
+*       DOUBLE PRECISION FUNCTION DLAPY3( X, Y, Z )
+*
+*       .. Scalar Arguments ..
+*       DOUBLE PRECISION   X, Y, Z
+*       ..
+*
+*
+*> \par Purpose:
+*  =============
+*>
+*> \verbatim
+*>
+*> DLAPY3 returns sqrt(x**2+y**2+z**2), taking care not to cause
+*> unnecessary overflow and unnecessary underflow.
+*> \endverbatim
+*
+*  Arguments:
+*  ==========
+*
+*> \param[in] X
+*> \verbatim
+*>          X is DOUBLE PRECISION
+*> \endverbatim
+*>
+*> \param[in] Y
+*> \verbatim
+*>          Y is DOUBLE PRECISION
+*> \endverbatim
+*>
+*> \param[in] Z
+*> \verbatim
+*>          Z is DOUBLE PRECISION
+*>          X, Y and Z specify the values x, y and z.
+*> \endverbatim
+*
+*  Authors:
+*  ========
+*
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
+*
+*> \ingroup OTHERauxiliary
+*
+*  =====================================================================
       DOUBLE PRECISION FUNCTION DLAPY3( X, Y, Z )
 *
-*  -- LAPACK auxiliary routine (version 3.2) --
+*  -- LAPACK auxiliary routine --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
-*     November 2006
 *
 *     .. Scalar Arguments ..
       DOUBLE PRECISION   X, Y, Z
 *     ..
 *
-*  Purpose
-*  =======
-*
-*  DLAPY3 returns sqrt(x**2+y**2+z**2), taking care not to cause
-*  unnecessary overflow.
-*
-*  Arguments
-*  =========
-*
-*  X       (input) DOUBLE PRECISION
-*  Y       (input) DOUBLE PRECISION
-*  Z       (input) DOUBLE PRECISION
-*          X, Y and Z specify the values x, y and z.
-*
 *  =====================================================================
 *
 *     .. Parameters ..
@@ -30,18 +81,22 @@
       PARAMETER          ( ZERO = 0.0D0 )
 *     ..
 *     .. Local Scalars ..
-      DOUBLE PRECISION   W, XABS, YABS, ZABS
+      DOUBLE PRECISION   W, XABS, YABS, ZABS, HUGEVAL
+*     ..
+*     .. External Subroutines ..
+      DOUBLE PRECISION   DLAMCH
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          ABS, MAX, SQRT
 *     ..
 *     .. Executable Statements ..
 *
+      HUGEVAL = DLAMCH( 'Overflow' )
       XABS = ABS( X )
       YABS = ABS( Y )
       ZABS = ABS( Z )
       W = MAX( XABS, YABS, ZABS )
-      IF( W.EQ.ZERO ) THEN
+      IF( W.EQ.ZERO .OR. W.GT.HUGEVAL ) THEN
 *     W can be zero for max(0,nan,0)
 *     adding all three entries together will make sure
 *     NaN will not disappear.