1. store_src_rg                   xy = src.rg
    2. init_lane_masks                CondMask = LoopMask = RetMask = true
    3. copy_constant                  gInitialized = 0xBF800000 (-1.0)
    4. copy_constant                  gInitializedFromOther = 0x3F800000 (1.0)
    5. zero_slot_unmasked             gUninitialized = 0
    6. copy_constant                  $0 = 0x3F800000 (1.0)
    7. copy_slot_unmasked             gUninitialized = $0
    8. label                          label 0x00000000
    9. zero_slot_unmasked             [main].result(0) = 0
   10. copy_slot_unmasked             [main].result(1) = gInitializedFromOther
   11. zero_slot_unmasked             [main].result(2) = 0
   12. copy_slot_unmasked             [main].result(3) = gUninitialized
   13. load_src                       src.rgba = [main].result