diff options
Diffstat (limited to 'BLAS/SRC/cswap.f')
| -rw-r--r-- | BLAS/SRC/cswap.f | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/BLAS/SRC/cswap.f b/BLAS/SRC/cswap.f new file mode 100644 index 00000000..4a2b33bf --- /dev/null +++ b/BLAS/SRC/cswap.f @@ -0,0 +1,47 @@ + SUBROUTINE CSWAP(N,CX,INCX,CY,INCY) +* .. Scalar Arguments .. + INTEGER INCX,INCY,N +* .. +* .. Array Arguments .. + COMPLEX CX(*),CY(*) +* .. +* +* Purpose +* ======= +* +* interchanges two vectors. +* jack dongarra, linpack, 3/11/78. +* modified 12/3/93, array(1) declarations changed to array(*) +* +* +* .. Local Scalars .. + COMPLEX CTEMP + 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 + CTEMP = CX(IX) + CX(IX) = CY(IY) + CY(IY) = CTEMP + IX = IX + INCX + IY = IY + INCY + 10 CONTINUE + RETURN +* +* code for both increments equal to 1 + 20 DO 30 I = 1,N + CTEMP = CX(I) + CX(I) = CY(I) + CY(I) = CTEMP + 30 CONTINUE + RETURN + END |