    1. store_device_xy01              $1..4 = DeviceCoords.xy01
    2. copy_constant                  $3 = 0x3F000000 (0.5)
    3. copy_constant                  $4 = 0x3F000000 (0.5)
    4. cmpeq_2_floats                 $1..2 = equal($1..2, $3..4)
    5. bitwise_and_int                $1 &= $2
    6. store_src_rg                   xy = src.rg
    7. init_lane_masks                CondMask = LoopMask = RetMask = true
    8. copy_constant                  gInitialized = 0xBF800000 (-1.0)
    9. trace_var                      TraceVar(gInitialized) when $1 is true
   10. copy_constant                  gInitializedFromOther = 0x3F800000 (1.0)
   11. trace_var                      TraceVar(gInitializedFromOther) when $1 is true
   12. zero_slot_unmasked             gUninitialized = 0
   13. trace_var                      TraceVar(gUninitialized) when $1 is true
   14. trace_enter                    TraceEnter(float4 main(float2 xy)) when $1 is true
   15. trace_var                      TraceVar(xy) when $1 is true
   16. trace_scope                    TraceScope(+1) when $1 is true
   17. trace_line                     TraceLine(12) when $1 is true
   18. trace_enter                    TraceEnter(void init_globals()) when $1 is true
   19. trace_scope                    TraceScope(+1) when $1 is true
   20. trace_line                     TraceLine(8) when $1 is true
   21. copy_constant                  $0 = 0x3F800000 (1.0)
   22. copy_slot_unmasked             gUninitialized = $0
   23. trace_var                      TraceVar(gUninitialized) when $1 is true
   24. trace_scope                    TraceScope(-1) when $1 is true
   25. trace_exit                     TraceExit(void init_globals()) when $1 is true
   26. label                          label 0x00000000
   27. trace_line                     TraceLine(13) when $1 is true
   28. zero_slot_unmasked             [main].result(0) = 0
   29. copy_slot_unmasked             [main].result(1) = gInitializedFromOther
   30. zero_slot_unmasked             [main].result(2) = 0
   31. copy_slot_unmasked             [main].result(3) = gUninitialized
   32. trace_var                      TraceVar([main].result) when $1 is true
   33. trace_scope                    TraceScope(-1) when $1 is true
   34. trace_exit                     TraceExit(float4 main(float2 xy)) when $1 is true
   35. load_src                       src.rgba = [main].result