原版:
改进一:
{
void* ret = dest;
if (dest <= source || dest >= (source + count))
{
//Non-Overlapping Buffers
//copy from lower addresses to higher addresses
while (count --)
*dest++ = *source++;
}
else
{
//Overlapping Buffers
//copy from higher addresses to lower addresses
dest += count - 1;
source += count - 1;
while (count--)
*dest-- = *source--;l
}
return ret;
}
改进二:
{
assert((((uintptr_t) dest | (uintptr_t) src | n) & 0x03) == 0);
uint32_t* d = (uint32_t*) dest;
const uint32_t* s = (uint32_t*) src;
n /= sizeof(uint32_t);
if (d < s) {
/* copy forward */
while (n--) {
*d++ = *s++;
}
} else {
/* copy backward */
d += n;
s += n;
while (n--) {
*--d = *--s;
}
}
}
原文链接: https://www.cnblogs.com/springmvc-hibernate/archive/2012/01/01/2484047.html
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