Performance on amd64

John Skaller skaller at
Tue Jul 5 11:25:18 EDT 2005

On Tue, 2005-07-05 at 12:39 +0100, Simon Marlow wrote:
> On 05 July 2005 10:38, John Skaller wrote:
> >         Can someone comment on the Debian package for Ubuntu Hoary
> >         providing ghc-6.2.2 with binary for amd64?
> You're probably running an unregisterised build, which is going to be
> generating code at least a factor of 2 slower than a registerised build.
> You can get an up to date snapshot of 6.4.1 for Linux/x86_64 here:
> known-linux.tar.bz2

Thanks, downloading it now.. will try. What exactly is 
a 'registered' build?

> This build is registerised, but doesn't have the native code generator.

Which would generate the best code?

> I hope you're not going to conclude *anything* based on the performance
> of ackermann and tak! :-)

Ackermann is a good test of optimisation of a recursive
function, which primarily require the smallest possible
stack frame. Of course it is only one function, more need
to be tested.

In fact, this one test has been very good helping me get
the Felix optimiser to work well -- the raw code generated
without optimisation creates a heap closure for every function,
including ones synthesised for conditionals and matches, etc.
If I remember rightly, it took 2 hours to calculate Ack(3,6),
and I needed a friend to use a big PPC to get the result
in two hours for Ack(3,7).

So ... you could say the Felix optimiser has improved a bit... :)

If you would like to suggest other tests I'd be quite interested.
At the moment I'm using code from the Alioth Shootout, 
simply because I can -- saves writing things in languages
I don't know (which includes Haskell unfortunately).

John Skaller <skaller at users dot sourceforge dot net>
Download Felix:
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