Re: Update to jump thread selection code

[Jeffrey A Law <law at redhat dot com>]

On Mon, 2005-04-25 at 08:47 +0200, Michael Matz wrote:
> Hi Jeff,
> 
> On Fri, 22 Apr 2005, Jeffrey A Law wrote:
> 
> > This change finally updates the jump threading selection code to allow
> > threading through blocks with side effects that must be preserved.  This
> > allows us to thread ~40% more jumps (static count).  Or to look at it
> > another way, we're able to reduce the number of runtime conditional
> > jumps executed by ~4% (SPECINT2000).
> 
> Nice.  Do you have numbers somewhere what this means in overall 
> performance (for the overall set of patches perhaps)?
It's a small, but measurable overall improvement (less than 1%), but
I don't have the last set of SPEC2000 runs handy anymore.


> > We have one case which can result in compile-time explosions that I've
> > had to throttle.
> 
> Have you tried this also on something like Brad Luciers ugly big compile 
> time hogs?  Would be interesting.
No I haven't.

jeff