Programmer 7500/MAX_PROGRAMMERS.iso/PASCAL/TP_ADV.ZIP/LIST0506.PAS

Pascal/Delphi Source File | 1989-07-31 | 1.5 KB | 34 lines

Program TestOne;
{ This sample program illustrates calling a function that      }
{ contains an inline function.  It will simply add two byte    }
{ sized parameters, and place the result into the temporary    }
{ memory location that the Turbo Pascal code generator  will   }
{ allocate on the stack.  This is illustrated by the last MOV  }
{ instruction before the end of the function.                  }

Var
  X, Y : Byte;     { Variables that will be passed to function }
  Result : Word;   { Result of the call to function AddBytes   }

Function AddBytes( X, Y : Byte ) : Word;
{ This function will simply transfer the two parameters passed }
{ into the AX and BX registers and add them.  It will then     }
{ place the result of the function into the memory locations   }
{ That Turbo Pascal has allocated for the function result.     }
Begin
  Inline( $31/$C0/                 { XOR AX,AX      }
          $8B/$46/$04/             { MOV AX,[BP+04] }
          $8B/$5E/$06/             { MOV BX,[BP+06] }
          $01/$D8/                 { ADD AX,BX      }
          $89/$46/$FE );           { MOV [BP-02],AX }
End;

Begin
  X := 20;         { First operand to be passed to the function }
  Y := 30;         { Second operand to be passed to function    }
  Result := AddBytes( X, Y ); { Call the function               }
  WRiteln( Result ); { Echo result of function to the screen    }
  Readln;          { Pause till return is hit to view output    }
End.