Re: str_repeat() patch

Well, surely memmove() needs an additional branch to check for overlapping, though (the OP was wrong in that memmove() would need a temporary buffer, though - it doesn't, it usually copies from high addres to low in the overlapping case). Cheers, Michael George Schlossnagle wrote:

On Jun 12, 2004, at 10:27 AM, Alexander Valyalkin wrote:

On Fri, 11 Jun 2004 17:00:03 +0200 (CEST), Derick Rethans <derick@php.net> wrote:

On Fri, 11 Jun 2004, Alexander Valyalkin wrote:

Read it: void *memmove(void *s1, const void *s2, size_t n); If s1 and s2 overlap, all bytes are copied in a preserving manner (unlike memcpy()) And anwer the question: are s1 and s2 overlap in the str_repeat() ? Why don't use memcpy() instead of memmove() ?

Because it's slower and we're copying to newly allocated memory anyway so things CAN not overlap. Also, your patch is the wrong way around.

Mybe I'm mistaken, but I think, that memmove() looks like that (without any error checks):

That's not what my glibc sources look like. George