sasum.f

          REAL FUNCTION SASUM(N,SX,INCX)
    *     .. Scalar Arguments ..
          INTEGER INCX,N
    *     ..
    *     .. Array Arguments ..
          REAL SX(*)
    *     ..
    *
    *  Purpose
    *  =======
    *
    *     takes the sum of the absolute values.
    *     uses unrolled loops for increment equal to one.
    *     jack dongarra, linpack, 3/11/78.
    *     modified 3/93 to return if incx .le. 0.
    *     modified 12/3/93, array(1) declarations changed to array(*)
    *
    *

    *     .. Local Scalars ..
          REAL STEMP
          INTEGER I,M,MP1,NINCX
    *     ..
    *     .. Intrinsic Functions ..
          INTRINSIC ABS,MOD
    *     ..
          SASUM = 0.0e0
          STEMP = 0.0e0
          IF (N.LE.0 .OR. INCX.LE.0) RETURN
          IF (INCX.EQ.1) GO TO 20
    *
    *        code for increment not equal to 1
    *
          NINCX = N*INCX
          DO 10 I = 1,NINCX,INCX
              STEMP = STEMP + ABS(SX(I))
       10 CONTINUE
          SASUM = STEMP
          RETURN
    *
    *        code for increment equal to 1
    *
    *
    *        clean-up loop
    *
       20 M = MOD(N,6)
          IF (M.EQ.0) GO TO 40
          DO 30 I = 1,M
              STEMP = STEMP + ABS(SX(I))
       30 CONTINUE
          IF (N.LT.6) GO TO 60
       40 MP1 = M + 1
          DO 50 I = MP1,N,6
              STEMP = STEMP + ABS(SX(I)) + ABS(SX(I+1)) + ABS(SX(I+2)) +
         +            ABS(SX(I+3)) + ABS(SX(I+4)) + ABS(SX(I+5))
       50 CONTINUE
       60 SASUM = STEMP
          RETURN
          END