Current state

What is supported

The only supported architecture right now is x86-64. Being a prototype, LLV8 is not able to compile all of the JavaScript at the moment. However, the working subset is substantial. And most of the conceptual issues (I believe) are resolved. Most notably, interactions of the compiled code with the garbage collector.

For more information see our list of issues and the [design doc](Design doc).

Profit?

Talking about speed-ups might be a bit early, because the right time for optimization is just about to come. However what we have observed so far is that the performance of the code is pretty much the same as for CrankShaft. Compile times (not surprisingly) are much larger (we are using the standard -O3 both for the set of IR transformation passes and for backend optimization level). To give some numbers, the compile times can be about 400 ms (llvm) vs. 10 ms (crankshaft) for a medium-sized asm.js program.

Failing tests

21 out of 160 tests are failing in llv8-regtests (going to post the list later).