Why does compiler produce different code for 46: Disp=DispData8; C:0x02DD 908082 MOV DPTR,#Disp(0x8082) C:0x02E0 7438 MOV A,#0x38 C:0x02E2 F0 MOVX @DPTR,A 47: wait(22); C:0x02E3 7F16

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  Westonsupermare Pier over 5 years ago in reply to GEAG +1
  Is there a store instruction beyond the last line you showed? Optimizer looks to have decided it doesn't need to reload DPTR
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  Broeker over 5 years ago in reply to GEAG +1
  GEAG said: I doubt that the compiler would do this to a write to IO in the system. Why wouldn't it? Did you tell the compiler that that's I/O, instead of plain memory?