    1. store_src_rg                   coords = src.rg
    2. init_lane_masks                CondMask = LoopMask = RetMask = true
    3. zero_4_slots_unmasked          result = 0
    4. copy_constant                  $0 = colorGreen(0)
    5. copy_slot_unmasked             result(0) = $0
    6. copy_constant                  $0 = colorGreen(1)
    7. copy_slot_unmasked             result(1) = $0
    8. copy_constant                  $0 = colorGreen(2)
    9. copy_slot_unmasked             result(2) = $0
   10. copy_constant                  $0 = colorGreen(3)
   11. copy_slot_unmasked             result(3) = $0
   12. copy_4_slots_unmasked          $0..3 = result
   13. load_src                       src.rgba = $0..3