LAPACK 3.3.0

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```00001       SUBROUTINE DLADIV( A, B, C, D, P, Q )
00002 *
00003 *  -- LAPACK auxiliary routine (version 3.2) --
00004 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
00005 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
00006 *     November 2006
00007 *
00008 *     .. Scalar Arguments ..
00009       DOUBLE PRECISION   A, B, C, D, P, Q
00010 *     ..
00011 *
00012 *  Purpose
00013 *  =======
00014 *
00015 *  DLADIV performs complex division in  real arithmetic
00016 *
00017 *                        a + i*b
00018 *             p + i*q = ---------
00019 *                        c + i*d
00020 *
00021 *  The algorithm is due to Robert L. Smith and can be found
00022 *  in D. Knuth, The art of Computer Programming, Vol.2, p.195
00023 *
00024 *  Arguments
00025 *  =========
00026 *
00027 *  A       (input) DOUBLE PRECISION
00028 *  B       (input) DOUBLE PRECISION
00029 *  C       (input) DOUBLE PRECISION
00030 *  D       (input) DOUBLE PRECISION
00031 *          The scalars a, b, c, and d in the above expression.
00032 *
00033 *  P       (output) DOUBLE PRECISION
00034 *  Q       (output) DOUBLE PRECISION
00035 *          The scalars p and q in the above expression.
00036 *
00037 *  =====================================================================
00038 *
00039 *     .. Local Scalars ..
00040       DOUBLE PRECISION   E, F
00041 *     ..
00042 *     .. Intrinsic Functions ..
00043       INTRINSIC          ABS
00044 *     ..
00045 *     .. Executable Statements ..
00046 *
00047       IF( ABS( D ).LT.ABS( C ) ) THEN
00048          E = D / C
00049          F = C + D*E
00050          P = ( A+B*E ) / F
00051          Q = ( B-A*E ) / F
00052       ELSE
00053          E = C / D
00054          F = D + C*E
00055          P = ( B+A*E ) / F
00056          Q = ( -A+B*E ) / F
00057       END IF
00058 *
00059       RETURN
00060 *