Some free or "MIPS-like" CPUs don't implement it because of a patent problem. I've seen at least one implementation on opencores.org that has this (missing) feature. Probably if the compiler were to emit lwl and lwr code via __attribute__((packed)), these instructions would have to be emulated by the kernel on such a CPU. I imagine this would be quite a bit worse than just doing two normal loads and extracting the desired word. Will On Tue, May 20, 2003 at 06:32:31PM +0000, Gilad Benjamini wrote: > Hi, > About two months ago there was a discussion > here about disabling lwl-lwr. > > Can someone shed some light on why the discussion > emerged ? > > Is this a performance issue, a processor which > doesn't support it, or something else ? > > If this is a performance issue, I'll be happy > to hear more details. > > TIA > > >
