[U-Boot] [PATCH V2 1/3] memcpy: copy one word at a time if possible
Mike Frysinger
vapier at gentoo.org
Fri Oct 9 12:26:58 CEST 2009
On Friday 09 October 2009 06:11:16 Mark Jackson wrote:
> Chris Moore wrote:
> > I agree wholeheartedly with the idea but shouldn't it be more like this
> > (untested) code :
> >
> > void * memcpy(void *dest, const void *src, size_t count)
> >
> > {
> > char *d8, *s8;
> > unsigned long *dl = dest, *sl = src;
>
> In here, would it be overkill to add byte copying until data is aligned,
> and then fall into the aligned copy code.
both addresses have to be unaligned the same ...
if ((ulong)dl & (sizeof(*dl) - 1) == (ulong)sl & (sizeof(*sl) - 1))
> In that case, you'd still gain a speed increase if you're starting at an
> unaligned address ?
now it's a question of how often does this come up and is it worth the code
size increase ?
-mike
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