Re: [patch 4/7] Immediate Values - i386 Optimization

H. Peter Anvin
2007-09-19T17:44:20Z

Jeremy Fitzhardinge wrote:
>
> Cross-cache-line, sure. But what about just not sizeof aligned? If its
> enough to avoid cross-cache-line, then that's simpler.
>

Not really. It pretty much comes down to the same problem.

> Which is something I was going to comment on: Mathieu, you try to align
> the constant itself, but you don't prevent the instruction overall from
> crossing a cache line. Given how delicate all this stuff is, it seems
> like a good idea to do that.

Given how delicate all his stuff is, it would be interesting to know the
magnitude of the expected payoff, which I personally don't remember seeing.

-hpa