C******************************************************************************
C FILE: loop01.f
C DESCRIPTION:
C   Demonstrates loop fusion
C******************************************************************************
	program loop01

	IMPLICIT NONE
	integer ARRAY_SIZE
	parameter(ARRAY_SIZE = 100000)
	integer	I, J
        real A(ARRAY_SIZE), AA(ARRAY_SIZE)
        real B(ARRAY_SIZE), BB(ARRAY_SIZE)
        real C(ARRAY_SIZE), CC(ARRAY_SIZE)
        real X, Y, XX, YY
        integer(8) T1, T2, IRTC

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

        DO I=1, ARRAY_SIZE
          X = X * A(I) + B(I)
        ENDDO
        DO I=1, ARRAY_SIZE
          Y = Y * A(I) + C(I)
        ENDDO

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

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

        DO I=1, ARRAY_SIZE
          XX = XX * AA(I) + BB(I)
          YY = YY * AA(I) + CC(I)
        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 *, X,Y,XX,YY

999   end