[Vm-dev] 3 Bugs in LargeInteger primitives

[Nicolas Cellier]

OK, see also http://code.google.com/p/cog/issues/detail?id=93

2012/9/1 Stefan Marr <smalltalk at stefan-marr.de>:
>
> Hi Nicolas:
>
> On 01 Sep 2012, at 22:15, Nicolas Cellier wrote:
>
>> I just tried on a stack VM (MacOSX core 2...), and I get different
>> measurements, at most 3% penalty, not 20%
>
> Sorry, the 20% claim is based on wrong assumptions...
> In short, I don't know what the penalty is on microbenchmarks.
>
> I was only checking the benchmark results here:
>   http://soft.vub.ac.be/~ppp/codespeed/changes/?tre=5&rev=5e18a83ed285c900aacd4190f91df6627d9ccc01&exe=1&env=2
> The corresponding patch is here:
>   https://github.com/smarr/RoarVM/commit/5e18a83ed285c900aacd4190f91df6627d9ccc01
>
> As you can see, the IntLoop benchmark is taking a pretty strong hit.
> I was not cross-checking what the benchmark actually does, unfortunately.
> I was just assuming it does multiplication, which would explain the hit, but it does only do subtraction.
>
> So, actually, I don't know.
> The benchmark is not measuring that primitive, and the other benchmarks are looking ok (taking measurement errors into account).
>
> Still wonder what's wrong with the IntLoop benchmark thought. 20% for perhaps a new offset in the binary for related code, sounds like a lot.
>
>
> Best regards
> Stefan
>
>
> --
> Stefan Marr
> Software Languages Lab
> Vrije Universiteit Brussel
> Pleinlaan 2 / B-1050 Brussels / Belgium
> http://soft.vub.ac.be/~smarr
> Phone: +32 2 629 2974
> Fax:   +32 2 629 3525
>