On Sun, Mar 22, 2015 at 10:36 AM, David Miller <davem@xxxxxxxxxxxxx> wrote:
>
> And they end up using that byte-at-a-time code, since SLAB and SLUB
> do mmemove() calls of the form:
>
> memmove(X + N, X, LEN);
Actually, the common case in slab is overlapping but of the form
memmove(p, p+x, len);
which goes to memcpy. It's basically re-compacting the array at the beginning.
Which was why I was asking how sure you are that memcpy *always*
copies from low to high.
I don't even know which version of memcpy ends up being used on M7.
Some of them do things like use VIS. I can follow some regular sparc
asm, there's no way I'm even *looking* at that. Is it really ok to use
VIS registers in random contexts?
Linus
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