Re: Is clobber "memory" in include/asm-i386/system.h necessary?

Bryn Paul Arnold Jones (bpaj@gytha.demon.co.uk)
Sat, 4 May 1996 00:33:24 +0100 (BST)

On Thu, 2 May 1996, Linus Torvalds wrote:
>
> Essentially, you can think of the memory clobbers as barriers, and think of
> "cli" and "sti" as
>
> cli();
> barrier();
>
> and
>
> barrier();
> sti();
>
> respectively.
>

Hmm, the clobbers make gcc not optermize across the the cli()/sti()/...,
but gcc can still optermize before, inside, and after (just not across)
correct ? So the real advantage is gcc can optermize (hmm, I think I'm
spelling optermize wrong) throughout, and get rid of the
silly/slow/unused/whatever, which wouldent happen with volitile (as well
as suiteing you (Linus) ;). Am I correct, or way off ?

> Linus
>
Bryn

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