Statistiques
| Révision :

root / src / blas / zswap.f @ 10

Historique | Voir | Annoter | Télécharger (1,01 ko)

1 1 pfleura2
      SUBROUTINE ZSWAP(N,ZX,INCX,ZY,INCY)
2 1 pfleura2
*     .. Scalar Arguments ..
3 1 pfleura2
      INTEGER INCX,INCY,N
4 1 pfleura2
*     ..
5 1 pfleura2
*     .. Array Arguments ..
6 1 pfleura2
      DOUBLE COMPLEX ZX(*),ZY(*)
7 1 pfleura2
*     ..
8 1 pfleura2
*
9 1 pfleura2
*  Purpose
10 1 pfleura2
*  =======
11 1 pfleura2
*
12 1 pfleura2
*     interchanges two vectors.
13 1 pfleura2
*     jack dongarra, 3/11/78.
14 1 pfleura2
*     modified 12/3/93, array(1) declarations changed to array(*)
15 1 pfleura2
*
16 1 pfleura2
*
17 1 pfleura2
*     .. Local Scalars ..
18 1 pfleura2
      DOUBLE COMPLEX ZTEMP
19 1 pfleura2
      INTEGER I,IX,IY
20 1 pfleura2
*     ..
21 1 pfleura2
      IF (N.LE.0) RETURN
22 1 pfleura2
      IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20
23 1 pfleura2
*
24 1 pfleura2
*       code for unequal increments or equal increments not equal
25 1 pfleura2
*         to 1
26 1 pfleura2
*
27 1 pfleura2
      IX = 1
28 1 pfleura2
      IY = 1
29 1 pfleura2
      IF (INCX.LT.0) IX = (-N+1)*INCX + 1
30 1 pfleura2
      IF (INCY.LT.0) IY = (-N+1)*INCY + 1
31 1 pfleura2
      DO 10 I = 1,N
32 1 pfleura2
          ZTEMP = ZX(IX)
33 1 pfleura2
          ZX(IX) = ZY(IY)
34 1 pfleura2
          ZY(IY) = ZTEMP
35 1 pfleura2
          IX = IX + INCX
36 1 pfleura2
          IY = IY + INCY
37 1 pfleura2
   10 CONTINUE
38 1 pfleura2
      RETURN
39 1 pfleura2
*
40 1 pfleura2
*       code for both increments equal to 1
41 1 pfleura2
   20 DO 30 I = 1,N
42 1 pfleura2
          ZTEMP = ZX(I)
43 1 pfleura2
          ZX(I) = ZY(I)
44 1 pfleura2
          ZY(I) = ZTEMP
45 1 pfleura2
   30 CONTINUE
46 1 pfleura2
      RETURN
47 1 pfleura2
      END