Re: MIPS checksum bug

[Ralf Baechle <ralf@linux-mips.org>]

On Wed, Sep 17, 2008 at 07:21:23PM +0100, Maciej W. Rozycki wrote:

> > >  Hmm, what's the purpose of doing the fold in csum_partial() then?
> > 
> > Well, maybe odd-byte handling requires 16-bit holded values?
> 
>  It should be enough to swap odd and even bytes in the word in the
> unaligned path.  Though perhaps extra code to do masking would make it no
> shorter/faster than what we have now; however the aligned path would
> benefit.  Hmm...

Which is a truely weird operation - but MIPS R2 happens to have a wonderful
instruction for this operation, WSBH / DSBH.

  Ralf