anchor.diff:       do i=1,sze
          degree_x2 = 0
          !DEC$ LOOP COUNT MIN(4)
  -       do l=1,Nint
  -         degree_x2 = degree_x2+ popcnt(xor( key1(l,1,i), key2(l,1))) +&
  -             popcnt(xor( key1(l,2,i), key2(l,2)))
  +       do m=1,Nint
  +         degree_x2 = degree_x2+ popcnt(xor( key1(m,1,i), key2(m,1))) +&
  +             popcnt(xor( key1(m,2,i), key2(m,2)))
            if (degree_x2 > 4) then
              exit
            endif
  
positive.code:      do i=1,sze
         degree_x2 = 0
         !DEC$ LOOP COUNT MIN(4)
         do l=1,Nint
           degree_x2 = degree_x2+ popcnt(xor( key1(l,1,i), key2(l,1))) +&
               popcnt(xor( key1(l,2,i), key2(l,2)))
           if (degree_x2 > 4) then
             exit
           endif
  
negative.code:   integer, intent(out)           :: idx(0:sze)
    integer, intent(out)           :: idx_repeat(0:sze)
    
    integer                        :: i,l,l_repeat,m
    integer                        :: degree_x2
  
    ASSERT (Nint > 0)
  