asmjit VS Befunge

Some other instruction sets in some JSON: https://github.com/asmjit/asmjit/tree/master/db

The attentive reader may notice that this code is from a third-party library. So, we didn't want to include it in the article at first. However, we found something interesting. In 2017, somebody opened an issue in the asmjit project: the GCC 7.2 compiler issued a warning to the code above. The project authors fixed it:

You can use something like https://asmjit.com/ to generate and call x64 code at runtime.

But an easy to create a JIT would be to use https://github.com/asmjit/asmjit, which is used in RPCS3.

You could go the way of https://asmjit.com (or forth) and make it your assembler DSL on top of the low-level call.

But if you're willing to get closer to the hardware is https://github.com/bitfunnel/nativejit/ and https://asmjit.com/

https://github.com/asmjit/asmjit is nice. But using a JIT seems like a sledgehammer working around a lacking design.

1. C compilers don't do a good job, & thus even CPython, which has historically stuck to rather vanilla C, uses computed goto, as described in https://eli.thegreenplace.net/2012/07/12/computed-goto-for-e...

I resorted to similar techniques in optimizing Befunge: https://github.com/serprex/Befunge (See bejit.c & marsh.c/marsh.h)

2. Rust enums are not variable sized, think of them as tagged C unions, where the Rust compiler can sometimes apply tricks to make Option> the same size as Vec

3. match can specialize for straight forward cases, when in doubt use https://godbolt.org

I've found async to be straight forward anytime I've used it. Promise#then is equivalent to callbacks

async/await often requires very little changes compared to synchronous code, whereas reworking a program into callbacks is much more impactful. & the async/await compilation process tends to produce better performance in addition to this. My first async/await work was a few years ago to increase a data importer's performance by an order of magnitude compared to the blocking code

Here's an example where looping made for a callback that recursively called, using async/await I get to use a plain loop:

before: https://github.com/serprex/Befunge/blob/946ea0024c4d87a1b75d...

after: https://github.com/serprex/Befunge/blob/9677ddddb7a26b7a17dd...

I don't see why people find it so complicated to separate begin-compute & wait-on-compute

I've since rewritten a nodejs game server into rust, https://github.com/serprex/openEtG/tree/master/src/rs/server... handleget/handlews are quite straight forward

You'll also find them used in CPython's ceval.c

I use them in both my C befunge implementations:

https://github.com/serprex/Befunge/blob/c97c8e63a4eb262f3a60...

https://github.com/serprex/Befunge/blob/c97c8e63a4eb262f3a60...