初学 Delphi 嵌入汇编[17] - 逻辑运算

//逻辑非 Not:
{
not 1 = 0;
not 0 = 1;
}
var
ByteNum: Byte;
begin
//赋值 11111111B (255) 取反:
asm
mov al, 11111111B {eax 包含 ax; ax 包含 al; al 是 eax 的低八位}
not al            {给 11111111 取反会得到 00000000}
mov ByteNum, al   {把寄存器 al 中的值给变量 ByteNum}
end;
ShowMessage(IntToStr(ByteNum)); {0}

//赋值 00000001B (1) 取反:
asm
mov al, 00000001B
not al            {给 00000001 取反会得到 11111110}
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {254}

//赋值 10000000B (128) 取反:
asm
mov al, 00000001B
not al            {给 10000000 取反会得到 01111111}
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {127}
end;

//逻辑或 Or:
{
1 or 0 = 1;
0 or 1 = 1;
1 or 1 = 1;
0 or 0 = 0;
}
var
ByteNum: Byte;
begin
asm
mov al, 10101010B {170}
mov cl, 01010101B {85}
or  al, cl
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {255}
end;

//逻辑与 And:
{
1 and 1 = 1;
1 and 0 = 0;
0 and 1 = 0;
0 and 0 = 0;
}
var
ByteNum: Byte;
begin
//例1
asm
mov al, 11111111B {255}
mov cl, 11111111B {255}
and al, cl
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {255}

//例2
asm
mov al, 00000000B {0}
mov cl, 00000000B {0}
and al, cl
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {0}

//例3
asm
mov al, 11111111B {255}
mov cl, 00000000B {0}
and al, cl
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {0}

//例4
asm
mov al, 10101010B {170}
mov cl, 01010101B {85}
and al, cl
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {0}
end;

//逻辑异或 Xor:
{
1 Xor 0 = 1;
0 Xor 1 = 1;
1 Xor 1 = 0;
0 Xor 0 = 0;
}
var
ByteNum: Byte;
begin
//例1
asm
mov al, 11111111B {255}
mov cl, 11111111B {255}
xor al, cl
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {0}

//例2
asm
mov al, 11111111B {255}
mov cl, 00000000B {0}
xor al, cl
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {255}

//例3
asm
mov al, 10101010B {170}
mov cl, 01010101B {85}
xor al, cl
mov ByteNum, al
end;
ShowMessage(IntToStr(ByteNum)); {255}
end;