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  • 初学 Delphi 嵌入汇编[20] Delphi 的 Integer 类型

    var
      I: Integer;
    begin
      //Integer 类型是4字节(32位)有符号整数, 最高位是符号位, 如果是正数, 符号位是 0、负数的符号位是1
      //所以 Integer 的最大值是: 01111111 11111111 11111111 111111112
      asm
        mov I, 01111111111111111111111111111111B;
      end;
      ShowMessage(IntToStr(I)); {2147483647}
    
    
      //有符号整数的负数等于相同正数的反码 + 1; Integer 最大值是:
      //01111111 11111111 11111111 111111112; 其反码是:     
      //10000000 00000000 00000000 000000002; 反码 + 1 以后是:
      //10000000 00000000 00000000 000000012
      asm
        mov I, 10000000000000000000000000000001B;
      end;
      ShowMessage(IntToStr(I)); {-2147483647}
    
    
      //那 Integer 的最小值是多少呢?
      //应该是: 10000000 00000000 00000000 000000002
      asm
        mov I, 10000000000000000000000000000000B;
      end;
      ShowMessage(IntToStr(I)); {-2147483648}
    
    
      //11111111 11111111 11111111 111111112 是?
      asm
        mov I, 11111111111111111111111111111111B;
      end;
      ShowMessage(IntToStr(I)); {-1}
    
    
      //Integer 类型的 0 在内存中是: 00000000 00000000 00000000 000000002
      asm
        mov I, 00000000000000000000000000000000B;
      end;
      ShowMessage(IntToStr(I)); {0}
    
    
      //Integer 类型的 10010 的二进制是: 00000000 00000000 00000000 011001002
      asm
        mov I, 00000000000000000000000001100100B;
      end;
      ShowMessage(IntToStr(I)); {100}
    
    
      //算 Integer 类型的 -10010:
      //00000000 00000000 00000000 01100100 的反码是:
      //11111111 11111111 11111111 10011011 ; 反码 + 1 以后是:
      //11111111 11111111 11111111 10011100
      asm
        mov I, 11111111111111111111111110011100B;
      end;
      ShowMessage(IntToStr(I)); {-100}
    end;
    
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  • 原文地址:https://www.cnblogs.com/del/p/1057314.html
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