memmove

if (d==s) return d;
if ((uintptr_t)s-(uintptr_t)d-n <= -2*n) return memcpy(d, s, n);


s - d - n mod p <= -2n mod p

s - d -n < 0
s - d -n <= -2n

s < d + n
s <= d -n

s| |d |

0 <= s - d -n <= p - 2n
s - d >= n
| |d |s
posted @ 2023-03-10 11:11  zJanly  阅读(33)  评论(0)    收藏  举报