C******************************************************************************
C FILE: loop11.f
C DESCRIPTION:
C   Demonstrates loop unrolling
C******************************************************************************

	program loop11

	IMPLICIT NONE
	integer DIM1, DIM2
	parameter(DIM1 = 400)
	parameter(DIM2 = 400)
	integer	I, J, K
        real A(DIM1, DIM2), AA(DIM1, DIM2)
        real B(DIM1, DIM2), BB(DIM1, DIM2)
        real C(DIM1, DIM2), CC(DIM1, DIM2)
        integer(8) T1, T2, IRTC

C*****************************************************************************
C*				Untuned Loop			             *
C*****************************************************************************
        T1 = IRTC()

        DO J=1, DIM2
          DO I=1, DIM1
            DO K=1, 4
              A(I, J) = A(I, J) + B(K, I) * C(K, J)
            ENDDO
          ENDDO
        ENDDO

        T2 = IRTC()
        write(*,*)'Untuned loop took', (T2-T1)/1000000, 'msec'

C*****************************************************************************
C*				Tuned Loop				     *
C*****************************************************************************
        T1 = IRTC()

        DO J=1, DIM2
          DO I=1, DIM1
            AA(I, J) = AA(I, J) + BB(1, I) * CC(1, J)
            AA(I, J) = AA(I, J) + BB(2, I) * CC(2, J)
            AA(I, J) = AA(I, J) + BB(3, I) * CC(3, J)
            AA(I, J) = AA(I, J) + BB(4, I) * CC(4, J)
          ENDDO
        ENDDO

        T2 = IRTC()
        write(*,*)'Tuned loop took', (T2-T1)/1000000, 'msec'

C       Need to actually use the results of the calculations or else the
C       optimizing compiler may just skip doing them...so we'll just
C       print them.  This will force the optimizer to actually do the work.
        print *, A(DIM1, DIM2), AA(DIM1, DIM2)

999   end