[PATCH] Optimize manual byte swap implementations v3

[Andreas Krebbel]

Hi Chris,

> Can't code like this just use __builtin_bswap_x?  Presumably this 
> expands to decent code when the target cpu doesn't support a bswap 
> instruction.

One of the problems is that __builtin_bswap is relatively new. I think 
it has been added with 4.3. So you again would need lovely GCC version 
checks around it.

Bye,

-Andreas-