1       DOUBLE COMPLEX FUNCTION ZDOTU(N,ZX,INCX,ZY,INCY)
 2 *     .. Scalar Arguments ..
 3       INTEGER INCX,INCY,N
 4 *     ..
 5 *     .. Array Arguments ..
 6       DOUBLE COMPLEX ZX(*),ZY(*)
 7 *     ..
 8 *
 9 *  Purpose
10 *  =======
11 *
12 *     ZDOTU forms the dot product of two vectors.
13 *
14 *  Further Details
15 *  ===============
16 *
17 *     jack dongarra, 3/11/78.
18 *     modified 12/3/93, array(1) declarations changed to array(*)
19 *
20 *  =====================================================================
21 *
22 *     .. Local Scalars ..
23       DOUBLE COMPLEX ZTEMP
24       INTEGER I,IX,IY
25 *     ..
26       ZTEMP = (0.0d0,0.0d0)
27       ZDOTU = (0.0d0,0.0d0)
28       IF (N.LE.0RETURN
29       IF (INCX.EQ.1 .AND. INCY.EQ.1THEN
30 *
31 *        code for both increments equal to 1
32 *
33          DO I = 1,N
34             ZTEMP = ZTEMP + ZX(I)*ZY(I)
35          END DO
36       ELSE
37 *
38 *        code for unequal increments or equal increments
39 *          not equal to 1
40 *
41          IX = 1
42          IY = 1
43          IF (INCX.LT.0) IX = (-N+1)*INCX + 1
44          IF (INCY.LT.0) IY = (-N+1)*INCY + 1
45          DO I = 1,N
46             ZTEMP = ZTEMP + ZX(IX)*ZY(IY)
47             IX = IX + INCX
48             IY = IY + INCY
49          END DO
50       END IF
51       ZDOTU = ZTEMP
52       RETURN
53       END