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Annotation of rpl/lapack/blas/zdotu.f, revision 1.7

1.1       bertrand    1:       DOUBLE COMPLEX FUNCTION ZDOTU(N,ZX,INCX,ZY,INCY)
                      2: *     .. Scalar Arguments ..
                      3:       INTEGER INCX,INCY,N
                      4: *     ..
                      5: *     .. Array Arguments ..
                      6:       DOUBLE COMPLEX ZX(*),ZY(*)
                      7: *     ..
                      8: *
                      9: *  Purpose
                     10: *  =======
                     11: *
                     12: *     ZDOTU forms the dot product of two vectors.
                     13: *
                     14: *  Further Details
                     15: *  ===============
                     16: *
                     17: *     jack dongarra, 3/11/78.
                     18: *     modified 12/3/93, array(1) declarations changed to array(*)
                     19: *
                     20: *  =====================================================================
                     21: *
                     22: *     .. Local Scalars ..
                     23:       DOUBLE COMPLEX ZTEMP
                     24:       INTEGER I,IX,IY
                     25: *     ..
                     26:       ZTEMP = (0.0d0,0.0d0)
                     27:       ZDOTU = (0.0d0,0.0d0)
                     28:       IF (N.LE.0) RETURN
1.7     ! bertrand   29:       IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
        !            30: *
        !            31: *        code for both increments equal to 1
        !            32: *
        !            33:          DO I = 1,N
        !            34:             ZTEMP = ZTEMP + ZX(I)*ZY(I)
        !            35:          END DO
        !            36:       ELSE
1.1       bertrand   37: *
                     38: *        code for unequal increments or equal increments
                     39: *          not equal to 1
                     40: *
1.7     ! bertrand   41:          IX = 1
        !            42:          IY = 1
        !            43:          IF (INCX.LT.0) IX = (-N+1)*INCX + 1
        !            44:          IF (INCY.LT.0) IY = (-N+1)*INCY + 1
        !            45:          DO I = 1,N
        !            46:             ZTEMP = ZTEMP + ZX(IX)*ZY(IY)
        !            47:             IX = IX + INCX
        !            48:             IY = IY + INCY
        !            49:          END DO
        !            50:       END IF
1.1       bertrand   51:       ZDOTU = ZTEMP
                     52:       RETURN
                     53:       END