#pythran export CDOTU(int, complex list, int, complex list, int)
#runas CDOTU(2,[complex(1,2),complex(2,3),complex(3,4),complex(5,6)],2,[complex(3,4),complex(1,2),complex(2,3),complex(5,6)],3)
#bench sz = 20000000; in1 = list(map(complex, range(sz), range(sz))); in2 = list(map(complex, range(sz), range(sz)));CDOTU(sz // 6,in1,2,in2,3)
def CDOTU(N,CX,INCX,CY,INCY):
#     .. Scalar Arguments ..
#     INTEGER INCX,INCY,N
#     ..
#     .. Array Arguments ..
#     COMPLEX CX(#),CY(#)
#     ..
#
#  Purpose
#  =======
#
#     CDOTU forms the dot product of two vectors.
#
#  Further Details
#  ===============
#
#     jack dongarra, linpack, 3/11/78.
#     modified 12/3/93, array(1) declarations changed to array(#)
#
#  =====================================================================
#
#     .. Local Scalars ..
#     COMPLEX CTEMP
#     INTEGER I,IX,IY
#     ..
    CTEMP = complex(0.0, 0.0)
    CDOTU = complex(0.0, 0.0)
    if (N <= 0):
        return
    if (INCX == 1 and INCY == 1):
#
#        code for both increments equal to 1
#
        for I in range(N):
            CTEMP = CTEMP + CX[I] * CY[I]
    else:
#
#        code for unequal increments or equal increments
#          not equal to 1
#
        IX = 0
        IY = 0
        if (INCX < 0):
            IX = (-N + 1) * INCX
        if (INCY < 0):
            IY = (-N + 1) * INCY
        for I in range(N):
            CTEMP = CTEMP + CX[IX] * CY[IY]
            IX = IX + INCX
            IY = IY + INCY
    return CTEMP
