假设源数据的第一个字节包含字符串长度，我们可以使用以下内容：

Assuming that the first byte of the source data contains the string length we could have something like:

--------------------------
|  4 |  A |  B |  C |  D |
--------------------------

所以MOVE循环会be：

So the MOVE loop would be:

// move the length byte from the source to the destination
MOVE (source,dest,1);  // dest[0] now contains 4
for (i=1; i <dest; i++)="" set="" i="1," and="" while="" <="" 4="" do="" the="" following<!--="" newline="" --="">{
    MOVE(source[i], dest[i], 1); // move the source byte at offset i to 
                                 // the byte at offset i of the destination
} // increment i and repeat while the value of i is less than 4

这将失败，因为循环将因此在复制偏移量4处的字节之前终止：

This will fail since the loop will terminate before copying the byte at offset 4 thus:

Value of i   copy byte
    1           A
    2           B
    3           C
    4 -> loop terminates since i is not less than byte 0 of dest.

所以for循环需要是

so the for loop needs to be

for (i=1; i <= dest; i++)

大多数指令集使用寄存器实现这一点，寄存器在复制每个字节后自动递增。要复制的编号放在一个特殊的寄存器中，该寄存器会在每次重复复制时倒计时。请参阅英特尔指令集 - REP [ ^ ]。

Most instruction sets implement this using registers that automatically increment after each byte is copied. The number to copy is put in a special register that counts down for each repetition of the copy. See Intel Instruction Set - REP[^].