negative memcpy

[manish kumar]

On Thu, Aug 11, 2011 at 9:53 AM, Denys Vlasenko
<vda.linux at googlemail.com> wrote:
> ...but the below doesn't look like memcpy from uclibc:
> in iclibc tree, uClibc/libc/string/mips/memcpy.S is hardly
> 5 screenfuls of code including comments,
> and it, for example, doesn't use "pref" instruction
> (and never did according to git log).
>
> Whereas code below is HUGEST: nearly FORTY screenfuls,
> and it uses "pref" insn.
>
> Google code search failed to find the source
> (I looked for "memcpy detect_done").
>
> Is this a modified uclibc, with someone's
> "more optimized" memcpy?

My  uClibc/libc/string/mips/memcpy.S is different from the uClibc
tree. I guess it is optimized one for the target. Anyway, how can it
copy such a huge data? Or is it not copying anything when ssize_t =
-1? And can it copy huge data as well, like, more than 0x80000000?