[LLVMdev] Issue with paper http://llvm.org/devmtg/2008-08/Geoffray_VMKitProject.pdf and presentation http://hal.inria.fr/docs/00/35/45/77/PDF/RR-6799.pdf

Kirill Kononenko kirill.kononenko at gmail.com
Mon Apr 20 12:42:55 PDT 2009

Dear all,

This new version of the paper at:


got ride of libJIT. Now my question is the how scientific is this
research and research paper if instead of using libJIT and
Portable.NET JIT:
authors of "VMKit: a Substrate for Virtual Machines by Nicolas
Geoffray — Gaël Thomas— Charles Clément —Bertil Folliot — Gilles
Muller" simply decided to decided remove research information all
together? Also how objective is Related Work part of this research
paper in this context?


2009/3/3 Nicolas Geoffray <nicolas.geoffray at lip6.fr>:
> Dear all,
> First, sorry for all that noise. I know you guys *just don't care*TM, but
> this requires some clarification. I won't say more than what's in this
> email.
> The VMKit paper dates from early 2008. It compares VMKit with pnet 0.7.4 and
> not the latest release (0.8.0) because we were not able to get any
> information to build it correctly at the time; the website that hosted
> libjit was broken, i.e. http://www.southern-storm.com.au. That said, here's
> the info that we have on the pnet website:
>> January 15-01-2006: DotGNU Portable.NET 0.7.4 and libjit 0.0.6 released!
>> New versions of Portable.NET and libjit are available. Far too many new
>> features and bug fixes to list them here, see the announcement which
>> includes a full list of new features and bug fixes. You can get it from the
>> download page.
>> December 03-12-2005: Portable.NET and libjit progress
>> Work on libjit (A JIT designed to be independent of any particular virtual
>> machine bytecode format or language) has resumed again and we are gearing
>> towards using it in Portable.NET soon. Recently, there have also been
>> donations which will be distributed amongst developers who contribute code
>> to get libjit finished and hook it into Portable.NET's runtime engine.
> Maybe it's our mistake if we misinterpreted the informations given on that
> webpage. From our understanding, libjit and pnet were merged in 0.7.4. Now
> that we all know pnet and libjit are two separate, alive, projects, we will
> stop refering to pnet only. The VMKit paper got rid of libjit references. As
> for the LLVM developer meeting presentation, there is no mention of libjit.
> End of the story.
> Nicolas
> Kirill Kononenko wrote:
>> Hi Chris,
>> Just in case that this information does not get corrupted I want to
>> point to the issue:
>> In http://llvm.org/devmtg/2008-08/Geoffray_VMKitProject.pdf it is on
>> page 21: "VMKit, Mono, PNet", Array bounds checks.
>> In http://hal.inria.fr/docs/00/35/45/77/PDF/RR-6799.pdf it is on page
>> 17: "We compare N3 with Mono [9] version 1.2.6, and PNet version 0.7.4
>> [2], which uses libjit as dynamic compiler...."
>> This statement is false. PNet version 0.7.4 has not been using LibJIT.
>> It has been using an unroller.
>> "The PNet performance show that libjit has very few optimizations and
>> does not compete against robust compilers."
>> In fact any amateur in Just-In-Time compilers, and Virtual Machine
>> engines, by just looking at this benchmark on the next page "Figure 7:
>> PNetMark results (higher is better)", can tell that PNet engine used
>> to take these measures has not been a Just-In-Time compiler. However,
>> the authors of the paper insist.
>> This benchmark definitely does not tell anything about LibJIT, as
>> LibJIT has not been used. In fact, we started development of LibJIT as
>> an answer to such benchmarks issues.
>> I can suggest the authors of these papers to use a real industrial VM
>> engine to compare. For instance, check Microsoft .NET or if you cannot
>> do this "for legal reason" try Java HotSpot. But not a 5 years old
>> version, although even that should give you more objective results
>> that you can understand what these benchmark mean in fact.
>> Thanks,
>> Kirill
>> 2009/3/2 Chris Lattner <clattner at apple.com>:
>>> On Mar 2, 2009, at 8:25 AM, Kirill Kononenko wrote:
>>>> Hello Dear LLVM Developers and Users
>>> Hi Kirill,
>>> Please talk to Nicholas about this, thanks!
>>> -Chris
>>>> I would like to complain about scientific inaccuracy of the paper
>>>> http://hal.inria.fr/docs/00/35/45/77/PDF/RR-6799.pdf written by
>>>> Nicolas Geoffray, Gaël Thomas, Charles Clément, Bertil Folliot, Gilles
>>>> Muller and presentation done by Nicolas Geoffray on LLVM conference
>>>> supported by Google:
>>>> http://llvm.org/devmtg/2008-08/Geoffray_VMKitProject.pdf
>>>> They provide comparison of their system that uses LLVM, with our
>>>> system Portable.NET that uses LibJIT for Just-In-Time compilation.
>>>> All measures in this paper have been done for Portable.NET 0.7.4,
>>>> which does not use LibJIT as its engine. However, the author provides
>>>> results of Portable.NET 0.7.4. as results of LibJIT. The Portable.NET
>>>> 0.7.4 uses a dynamic compiler, which has nothing in common with the
>>>> project and development of LibJIT. We are very upset with these papers
>>>> and that there are such "researchers" in your group. Portable.NET
>>>> 0.7.4 was released 3 years ago. LibJIT have been developed during the
>>>> last 3 years. We require that you remove this paper and this
>>>> presentation and make official excuses not only in this maillist but
>>>> also on the next conferences when you talk about LLVM.
>>>> Thanks,
>>>> Kirill
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