Making LLVM happy: memmove() in the kernel

[Sean C. Farley]

On Fri, 27 Feb 2009, Ed Schouten wrote:

> Hi all,
>
> The FreeBSD+LLVM folks* noticed Clang generates calls to memmove() by 
> itself. I have yet to confirm this, but I assume this is done when 
> performing copies of structs greater than a certain size. In our 
> kernel, we don't have a memmove() function, but we do have a bcopy().
>
> Because memmove() must be a function in this case (not a simple 
> macro), Roman and I agreed that adding a memmove() to libkern would be 
> the best thing to do for now, simply by calling bcopy(). ARM already 
> has a memmove() in support.S, so we don't need it there.
>
> So my question is: what is your folks opinion on this patch?
>
> 	http://80386.nl/pub/memmove.diff
>
> It would be lovely if we could integrate this patch (or a similar 
> one), because this will allow us to build kernels with Clang out of 
> the box.

Does bcopy() in the kernel allow for overlapping strings?

Sean
-- 
scf at FreeBSD.org