SETUMATCACHEFLAG Subroutine

    SUBROUTINE SETUMATCACHEFLAG(NEWFLAG)
        ! Change caching mode of UMatCache,
        ! In:
        !    NewFlag [0,1]: new value for UMatCacheFlag.
        !  flag=1: Storing just the <ik|u|jk> integrals in order they arrive
        !  in (and only have room to do so).
        !  flag=0: Distribute integrals throughout the cache in the scheme
        !  described at the top.
        INTEGER NEWFLAG
        SELECT CASE (UMATCACHEFLAG)
        CASE (1)
!  We were in direct cache mode where values were distributed correctly throughout the cache.
            IF (NEWFLAG == 0 .AND. .NOT. tSmallUMat) THEN
!  We need to fill the cache properly with values from the small cache.
                CALL FILLUPCACHE()
            end if
        END SELECT
        UMATCACHEFLAG = NEWFLAG
        SELECT CASE (NEWFLAG)
        CASE (1)
            IF (NSLOTS == NPAIRS) THEN ! we're storing every element, so we don't need to deal with different cacheing
                UMATCACHEFLAG = 0
            ELSE
                UMATLABELS(1:NSLOTS, 1:NPAIRS) = 0
!Turn on the direct caching, and clear the cache.
            end if
        END SELECT
        RETURN
    END SUBROUTINE SETUMATCACHEFLAG