1: SUBROUTINE ZAXPY(N,ZA,ZX,INCX,ZY,INCY)
2: * .. Scalar Arguments ..
3: DOUBLE COMPLEX ZA
4: INTEGER INCX,INCY,N
5: * ..
6: * .. Array Arguments ..
7: DOUBLE COMPLEX ZX(*),ZY(*)
8: * ..
9: *
10: * Purpose
11: * =======
12: *
13: * ZAXPY constant times a vector plus a vector.
14: *
15: * Further Details
16: * ===============
17: *
18: * jack dongarra, 3/11/78.
19: * modified 12/3/93, array(1) declarations changed to array(*)
20: *
21: * =====================================================================
22: *
23: * .. Local Scalars ..
24: INTEGER I,IX,IY
25: * ..
26: * .. External Functions ..
27: DOUBLE PRECISION DCABS1
28: EXTERNAL DCABS1
29: * ..
30: IF (N.LE.0) RETURN
31: IF (DCABS1(ZA).EQ.0.0d0) RETURN
32: IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
33: *
34: * code for both increments equal to 1
35: *
36: DO I = 1,N
37: ZY(I) = ZY(I) + ZA*ZX(I)
38: END DO
39: ELSE
40: *
41: * code for unequal increments or equal increments
42: * not equal to 1
43: *
44: IX = 1
45: IY = 1
46: IF (INCX.LT.0) IX = (-N+1)*INCX + 1
47: IF (INCY.LT.0) IY = (-N+1)*INCY + 1
48: DO I = 1,N
49: ZY(IY) = ZY(IY) + ZA*ZX(IX)
50: IX = IX + INCX
51: IY = IY + INCY
52: END DO
53: END IF
54: *
55: RETURN
56: END
CVSweb interface <joel.bertrand@systella.fr>