Compiling Racket to LLVM

[jbclements]

I found myself in a conversation today with Adam Perlin about compiling racket to LLVM, and I found myself wondering why there was no LLVM back-end for Racket[*]. After thinking about it for a while, I decided that the most likely reason was that with the pb back-end, compiling to LLVM (and then to some other target) probably isn't much of a win, or maybe even a win at all. Does that sound reasonable, or am I missing something obvious?

Thanks!

John

[*] Er... that I'm aware of?

[samth]

1. I don't think pb and compiling to LLVM are that related. pb is a bytecode with an interpreter, LLVM does not run via a portable interpreter.
2. The reason not to compile via LLVM is that it's hard, particularly for a GC'ed language with a non-trivial VM. It's possible to make it work but definitely non-trivial.
3. There was an effort by Eli Barzilay and Alex Friedman to write an LLVM backend for Racket in 2006; you can read more about it here: Racket: [plt-scheme] llvm and all that

[hendrikboom3]

When I looked at LLVM a few years ago, there were three things it did not understand:

• Garbage collection
• That sometimes you want to add an integer to a pointer and NOT HAVE IT SCALED!
• That it makes sense to access and use the fields of a structure before the definition of the structure is complete.

-- hendrik

[countvajhula]

This may be relevant: [2005.09028] Sham: A DSL for Fast DSLs. Excerpt: