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

Andi Kleen
2007-09-18T22:45:07Z

On Tue, Sep 18, 2007 at 03:29:50PM -0700, Jeremy Fitzhardinge wrote:
> Andi Kleen wrote:
> > Jeremy Fitzhardinge <jeremy@goop.org> writes:
> >
> >> It's a pity that gas seems to generate plain 0x90 nops rather than
> >> long-nop forms here. I thought it could do that.
> >>
> >
> > .p2align does it
>
> Just .p2align? Not align, balign, org or skip? Seems... strange.

The problem is that you cannot always safely jump into the middle of the
longer form nops. So I suppose they didn't risk breakage on older
code relying on this.

-Andi