Erlang on LLVM? or: Outsource your JIT!

Has anyone been working on using [LLVM][1] to do just-in-time code generation for the [Erlang][2] virtual machine?

Depending on the design and structure of the Erlang virtual machine, it doesn’t seem like it would be all that tough a project. And it could provide a nice performance boost for those projects that are starting to use Erlang like [CouchDB][3] and [ejabberd][4].

For an example of what I’m talking about, there’s a project called [VMKit][5] that has implemented the Java and .NET virtual machines atop LLVM with reasonable performance. Essentially, if you have a virtual machine, rather than skipping either just-in-time or static code generation entirely, or trying to do it all yourself for some specific platform on which you want to run, take a look at what you can do with LLVM and see if you can leverage its code generation instead.


Jon Harrop dives into OCaml on LLVM

As seen on the LLVMdev mailing list: Jon Harrop, Fibonacci example in OCaml:

Here is a complete 104-line native code compiler for a tiny subset of OCaml that is expressive enough to compile an external Fibonacci program: [...]

The compiler is itself written in OCaml, of course; for those who don’t know, OCaml or Objective Caml is an object-oriented dialect of Standard ML, a purely functional language.

Jon’s name rang a bell because I just listened to the second of two podcasts from .NET Rocks on the F# functional programming language — Jon Harrop Makes Us F# and F# Moves Forward — that Microsoft will be including with future versions of VIsual Studio. F# is itself a derivative of OCaml, runs atop the .NET Common Language Runtime, and can interoperate with other code

F# is interesting because, due to its functional and side-effect-free nature, one can get a huge amount of parallelism out of straightforward code. (It’s the lack of side effects that allow such analysis to be performed.) The Xbox Live matching service, for example, is using a TrueSkill engine developed in F# by Microsoft Research.

OCaml on LLVM is interesting in a lot of the same ways: You have a functional language that’s very amenable to all sorts of analysis and optimization, and an abstract platform that can run on an extremely wide variety of systems very efficiently. It’s really the best of both worlds, where you will be able to write the parts of your software that need to be highly parallel and mathematically rigorous in a language amenable to it, and interface that to the rest of your application in a very natural fashion.

It’s great to see that Jon is enjoying exploring OCaml atop LLVM and I can’t wait to see what kind of fun results!

Platform Futures

On Windows, many developers seem to want to run as fast as possible away from Microsoft Visual C++ and embrace Microsoft’s C# and .NET platform for new development. Most Windows developers that I’ve seen seem downright enthusiastic about these technologies. It’s disconcerting; I’m not used to seeing Windows developers (or users) be enthusiastic about their platform.

On the Mac, many developers are trying to hold onto C++ and Carbon for as long as they can, even for new development. A new Mac developer on the Carbon list actually said he wished Apple had a C++ framework that used MFC-like “message maps” for Mac OS X-only Carbon development “to make it easier to build software fast!” (Paraphrased.) And Metrowerks is spending money & time building a next-generation C++ PowerPlant framework for Mac OS X-only Carbon development! And some developers keep on Apple’s case to try and maintain feature parity between Carbon and Cocoa.

Fortunately, Apple isn’t giving in to them as much as they might think. For instance, WebKit has a Carbon wrapper, but it’s just a wrapper; WebView is really a Cocoa framework and if you want to extend it you’re going to have to use Cocoa. The Cocoa Controller layer is only really possible to do with a rich dynamic runtime; it’ll never make it to Carbon. You can only build screen savers using Cocoa and Objective-C. You can only build preference panes using Cocoa and Objective-C. Virtually all new applications coming out of Apple are built using Cocoa and Objective-C.

(Keynote, SoundTrack, LiveType, iCal, iPhoto, iSync, iChat AV, Safari… Final Cut and Logic don’t count, since they ware originally developed for the traditional Mac OS and thus aren’t new. Neither does Shake, since it was originally developed for Irix and X11 — though it wouldn’t surprise me at all to see it rearchitected as a Cocoa application in the next couple of years.)

The future of development on Windows is C# and .NET. This has been clear since Microsoft first released .NET, and it’s especially clear in light of the latest PDC and Longhorn.

The future of development on the Mac is Objective-C and Cocoa. This has been clear ever since Apple bought NeXT, and it’s especially clear in light of the latest WWDC and Panther.

Deal with it.

Joel Climbs Into the Trunk

Joel is smoking the good stuff! Or is he drinking the purple stuff?

Joel Spolsky of Joel on Software is actually claiming “.NET appears so far to be one of the most brilliant and productive development environments ever created.” He goes on to say “ASP.NET is as big a jump in productivity over ASP as Java is to C. Wow.”

Living inside Microsoft’s locked trunk for too long obviously ruins your sense of perspective. They’ve been steadily improving their tools over the years, but they started in such a truly awful state that what they have now seems like absolute luxury to Windows developers. If these people would bother to look outside their cramped quarters occasionally, they’d see that they really, honestly don’t have it very well off at all.

Here’s a choice quote:

I love the fact that you can use an ASP.NET calendar widget, which generates HTML that selects a date on a monthly calendar, and be confident that the “date” class you get back from that thing (System.DateTime, I believe) will be the exact same date class that the SQL Server classes expect. In the past you would not believe how much time we wasted doing things like reformatting dates for SQL statements, or converting COleDateTimes to someOtherKindOfDateTime.

I’d believe it because I’ve seen the kind of crap you have to go through to get anything done with Microsoft’s development tools and programming interfaces. In fact, I’ve written ported Macintosh software to Windows with them, and even tried to build Macintosh software with them (using their terrible Macintosh MFC SDK). It’s amazing Windows developers are ever able to get anything done.

Contrast that to OpenStep, WebObjects, and the Enterprise Objects Framework circa late 1995. There is one date class, NSGregorianDate. You didn’t have to write low-level code to access databases, so you didn’t have to worry about turning dates into strings you could embed in SQL statements. Instead, your Enterprise Objects – objects transparently backed by your database could just have attributes containing NSGregorianDate objects and The Right Thing would happen automatically.

As I read through this, I find more and more absolutely laughable comments. For instance:

First, they had the world’s best language designer, the man who was responsible for 90% of the productivity gains in software development in the last 20 years: Anders Hejlsberg, who gave us Turbo Pascal (thank you!), Delphi (thank you!), WFC (nice try!) and now .NET (smacked the ball outta the park).

Yes, the creator of Turbo Pascal is responsible for all of our productivity gains in software development. Especially since, even though Joel credits him as a “language designer” he didn’t really “design” Pascal or Object Pascal. Not, say, Alan Kay, leader of the team that invented true Object-Oriented Programming in the 1970s at Xerox and popularized it in 1980 with Smalltalk-80. Then again, that’s 22 years ago – maybe it doesn’t count (since Joel said “20 years”), even though industrywide movement to OOP didn’t really have critical mass until the 1990s…

Perhaps with .NET, Microsoft is only 5 years behind where NeXT was in 1995 with OpenStep, WebObjects, and the Enterprise Objects Framework. But they’re still 5 years behind where NeXT was, and now that NeXT has funding – in the form of millions of Apple Macintosh users running Mac OS X – they’re starting to move ahead quickly. If they can bring back the Objective-C version of EOF for Cocoa, they’ll be way ahead of the game.