1. store_src_rg                   xy = src.rg
    2. init_lane_masks                CondMask = LoopMask = RetMask = true
    3. zero_4_slots_unmasked          color = 0
    4. copy_constant                  $0 = 0x3F800000 (1.0)
    5. swizzle_4                      $0..3 = ($0..3).xxxx
    6. copy_4_slots_unmasked          color = $0..3
    7. label                          label 0x00000000
    8. copy_4_slots_unmasked          [main].result = color
    9. load_src                       src.rgba = [main].result