From: thoth@uiuc.edu (Ben Cox) Subject: Re: tlA: /bin/arch solved. Date: 26 Jul 1992 17:01:02 GMT
bjl@loki.pttrnl.nl (Ben Lippolt) writes:
>Thanks for your explanation. I was under the impression that the 486 had
>some extra instructions which the 386 didn't had.
This is the case, but the difference probably doesn't manifest itself
with -m486. The 486 has the BSWAP, XADD and CMPXCHG instructions,
which are not available on 386 processors.
I don't know if -m486 uses those, but I would very seriously doubt it.
BSWAP might be handy for TCP/IP stuff (it is htonl() and ntohl() in a
single instruction); XADD is handy primarily for multiprocessor loops,
and CMPXCHG is for semaphores in a MP system.
BSWAP might be used with -m486 (I doubt it), but XADD and CMPXCHG
probably aren't.