Re: Problem with NSString

[Ivan Vučica]

On 30. sij. 2011., at 23:29, David Chisnall <theraven@sucs.org> wrote:

> On 30 Jan 2011, at 21:35, Ivan Vučica wrote:
>
> > That is awesome?

Just want to point out this was supposed to ve "This is awesome!" with  
an exclamation mark ;-)

I mistyped this and it looks quite rude. Sorry!

> > Perhaps optimization pass could take a look if NSString subclasses  
> > exist and optimize if that is not the case as well?
>
> There's already a profile-driven pass that will look at this in  
> libobjc2 svn.  In fact, it doesn't check if there are subclasses, it  
> checks if the instances are always (or usually) the same class (so,  
> even if they are GSSubString or something, it will still work).  If  
> they are then it adds a cache for the lookup and tries speculative  
> inlining.
>
> If the speculative inlining works, then it's slightly faster tan a C  
> function call that is not inlined (of course, any place where  
> speculative inlining will work, C static inlining will also work, so  
> C will actually be faster).
>
> > > > This is currently only done in an experimental optimisation pass  
> > > > on my machine, but it will probably become one of the standard  
> > > > Objective-C passes used by clang for the GNUstep runtime sometime  
> > > > this year.
> > >
> > > Great! I am looking forward to this.
> >
> > Ditto!
>
>
> I'll try to finish / commit it at FOSDEM then.
>
> It's not a high priority, because message send overhead is rarely  
> the bottleneck for message sends to strings.  I just put it together  
> because I'm a bit OCD when it comes to optimising stuff...
>
> David
>
> -- Sent from my IBM 1620