diff options
Diffstat (limited to 'BLAS/SRC/zswap.f')
| -rw-r--r-- | BLAS/SRC/zswap.f | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/BLAS/SRC/zswap.f b/BLAS/SRC/zswap.f new file mode 100644 index 00000000..0b2dcd23 --- /dev/null +++ b/BLAS/SRC/zswap.f @@ -0,0 +1,47 @@ + SUBROUTINE ZSWAP(N,ZX,INCX,ZY,INCY) +* .. Scalar Arguments .. + INTEGER INCX,INCY,N +* .. +* .. Array Arguments .. + DOUBLE COMPLEX ZX(*),ZY(*) +* .. +* +* Purpose +* ======= +* +* interchanges two vectors. +* jack dongarra, 3/11/78. +* modified 12/3/93, array(1) declarations changed to array(*) +* +* +* .. Local Scalars .. + DOUBLE COMPLEX ZTEMP + INTEGER I,IX,IY +* .. + IF (N.LE.0) RETURN + IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20 +* +* code for unequal increments or equal increments not equal +* to 1 +* + IX = 1 + IY = 1 + IF (INCX.LT.0) IX = (-N+1)*INCX + 1 + IF (INCY.LT.0) IY = (-N+1)*INCY + 1 + DO 10 I = 1,N + ZTEMP = ZX(IX) + ZX(IX) = ZY(IY) + ZY(IY) = ZTEMP + IX = IX + INCX + IY = IY + INCY + 10 CONTINUE + RETURN +* +* code for both increments equal to 1 + 20 DO 30 I = 1,N + ZTEMP = ZX(I) + ZX(I) = ZY(I) + ZY(I) = ZTEMP + 30 CONTINUE + RETURN + END |