Hawk: A tracing JIT for scheme
I've been hacking on a tracing JIT compiler for scheme for a couple years now on and off, and it's in a pretty good state now. It has full R7RS support, with full seatbelts-on safety. Currently it's approximately 60% faster across the whole r7rs-benchmark suite than Chez scheme.
It's disproportionately faster on flonum benchmarks, it does quite well at inlining everything and keeping flonums in registers. I think it shows quite well that a JIT is especially helpful to get good numerical performance out of standard scheme, especially for flonums, making it possible to keep flonums in register much of the time.
There have been several previous scheme JIT attempts that took various approaches- Nash was based on Guile, but didn't quite get far enough along to see good results. Pycket was great, but used a continuations-on-the-heap approach, with quite different performance characteristics. Modern Guile has a template JIT, but currently does no register allocation or optimizations. Stalin only supported fixnums and flonums in its numerical tower, which allowed it to get great results. I wanted to support the full r7rs scheme numerical tower while still specializing as much as possible.
I've started writing a paper on the tracing JIT aspects, because some of these techniques I haven't seen elsewhere and may be novel.
Currently it supports x86-64 Linux & AArch64 OSX (sorry, no Windows yet).
Project page: