anchor.diff:            popcnt(xor( key1(1,2,i), key2(1,2)))
         if (degree_x2 > 4) then
           cycle
  -      else if(degree_x2 .ne. 0)then
  +      else if(degree_x2 /= 0)then
           idx(l) = i
           l = l+1
         endif
  
positive.code:   else
      
      !DIR$ LOOP COUNT (1000)
      do i=1,sze
        degree_x2 = 0
        !DEC$ LOOP COUNT MIN(4)
        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
        enddo
        if (degree_x2 > 4) then
          cycle
        else if(degree_x2 .ne. 0)then
            idx(l) = i
            l = l+1
        endif
      enddo
      
    endif
    idx(0) = l-1
  
negative.code:           popcnt(xor( key1(3,2,i), key2(3,2)))
        if (degree_x2 > 4) then
          cycle
        else if(degree_x2 /= 0)then
          idx(l) = i
          l = l+1
        endif
  