Re: raid 5 with >= 5 members broken on x86

From: Linus Torvalds
Date: Thu Feb 26 2004 - 17:28:17 EST




On Thu, 26 Feb 2004, Alexandre Oliva wrote:
>
> There's a reason why I added both asms, one with volatile and one
> without. I know what I'm doing. I even tried to explain it in the
> comments. Did you read them? Let me try again.

Ok, I'll buy it.

> > There is nothing to say that gcc wouldn't do a re-load or something
> > in between, so you really need to tell the _first_ ask about it.
>
> The only other reload it could do is an input reload of p4 and p5,
> which, again, doesn't matter, because p4 and p5 are dead anyway.

Ok. That's the missing piece. The thing is wrong, but we don't care,
because even if gcc saves the old values for some silly reload, they're
dead and uninteresting.

Ok. I did the silly one-liner, but if the "don't care" approach really
improves code generation, feel free to send one that fixes both the P5 and
PII cases..

Linus
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