Defining BYTE and SBYTE Data 

   val0   SBYTE   50h+10h   ; integer expression
   val1   BYTE    'A'       ; character constant
   val2   BYTE    255       ; largest unsigned byte
   val3   SBYTE   -128      ; smallest signed byte
   val4   BYTE    ?         ; space allocated but not the value
Each initializer must be an 8-bit integer expression or character constant.
Type Usage
BYTE 8-bit unsigned integer
SBYTE 8-bit signed integer


0 + (–10)


0 + 246


BYTE: (–10) + 20 

 INCLUDE Irvine32.inc
 .data
  X  BYTE  -10
 .code
 main PROC
  sub   eax, eax
  add   al, X
  call  DumpRegs
  exit
 main ENDP
 END main
 
 INCLUDE Irvine32.inc
 .data
  X  BYTE  246
 .code
 main PROC
  sub   eax, eax
  add   al, X
  call  DumpRegs
  exit
 main ENDP
 END main
 

 INCLUDE Irvine32.inc
 .data
  X  BYTE  -10
  Y  BYTE   20
 .code
 main PROC
  sub   eax, eax
  add   al, X
  add   al, Y
  call  WriteInt
  exit
 main ENDP
 END main

Output


Output


Output


EAX =  

 


EAX =  

 


 

 



SBYTE: (–10) + 20


SBYTE: 10 + (–20)


MOVSX: 10 + (–20) 

 INCLUDE Irvine32.inc
 .data
  X  SBYTE  -10
  Y  SBYTE   20
 .code
 main PROC
  sub   eax, eax
  add   al, X
  add   al, Y
  call  WriteInt
  exit
 main ENDP
 END main   
 INCLUDE Irvine32.inc
 .data
  X  SBYTE   10
  Y  SBYTE  -20
 .code
 main PROC
  sub   eax, eax
  add   al, X
  add   al, Y
  call  WriteInt
  exit
 main ENDP
 END main
 

 INCLUDE Irvine32.inc
 .data
  X  SBYTE   10
  Y  SBYTE  -20
 .code
 main PROC
  sub    eax, eax
  add    al, X
  add    al, Y
  movsx  eax, al
  call   WriteInt
  exit
 main ENDP
 END main

Output


Output


Output


 

 


 

 


 

 





      “I’m not arguing, I’m just explaining why I’m right.”    
      ― Unknown