Subject: Re: x86 instructions reordering
To: Lennart Augustsson <>
From: Manuel Bouyer <>
List: port-i386
Date: 03/24/2005 18:09:55
On Thu, Mar 24, 2005 at 05:14:49PM +0100, Lennart Augustsson wrote:
> The x86 can do some reordering, but nothing should ever
> move across an instruction with a lock prefix.  So with
> enough mb() in your code you should be totally safe.

And is __insn_barrier() equivalent to x86_lfence() in NetBSD ?
The generated assembly doesn't change when I use one or the other.
Using mb() didn't change anything either.
There's no "lock" in the generated assembly file, or nothing looking different
from normal instructions.

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference