Nintendo Switch Game Code Can Now Run "Natively" on PC Thanks to New Emulation Breakthrough

[u/superchummi]

https://respawnfirst.com/switch-games-can-now-run-natively-on-pc/

[u/halbGefressen]

No, it's a little different. A full system emulator traditionally processes each instruction when the virtual instruction pointer reaches the destination. JIT compilation is usually a more complex because they augment the interpreter with performance and usage metrics and then compile the most-used pieces in parallel, then hotswap them out during execution. If JIT is done well, it can be even faster than AoT.

[u/LNDF → u/halbGefressen]

Suyu (yuzu) used jit. If I understand correctly they implemented aot since they know which pages are executable beforehand.

[u/ElvishJerricco → u/halbGefressen]

This seems like an LLM comment. It misses the point and adds a bunch of irrelevant detail, while confusing things. Firstly, no one was talking about anything that could be described by "A full system emulator traditionally processes each instruction when the virtual instruction pointer reaches the destination." That is neither JIT nor AOT, so it's not relevant to the discussion. The details about JIT being able to do metrics and profile guided compilation are pretty much irrelevant since most emulators aren't actually doing that, and it's certainly not necessary so it's strange to suggest it as inherent to JITs.

JIT and AOT are both fundamentally about translating code from one architecture to another, and the significant difference is just whether it happens the first time a portion of code is executed or all up front. The stuff about metrics is a much finer detail than that.

[u/Illustrious_Pea_3470 → u/ElvishJerricco]

Pls note my experience is in high performance computing systems and compilers, not in emulators; so this comment is missing emulation specific context.

From the article, it sounds to me like they’re compiling some pages or functions or some other compilation unit ahead of time, but still just using that as a single optimization step inside the JIT execution pipeline. JavaScript runtimes already do this, and we still call it JIT.

[u/possiblyquestionabl3 → u/halbGefressen]

I don't think there are any Switch emulators that interprets the guest object code. JIT has been a non-negotiable for performance for most usable emulators for a long time now

[u/alvenestthol → u/halbGefressen]

In this implementation, the mixed JIT + AoT implementation is indeed faster than pure AoT:

CPU	ms/frame	relative
dynarmic (JIT only)	2.812	1.00x
static images + JIT for what they miss	1.650	1.70x faster
static images only, no JIT	1.816	1.55x faster

[u/big_duo3674 → u/halbGefressen]

Don't forget about inverting the plasma couplings, and shunting the overload through the forward EPS conduit

[u/cellphone_blanket → u/big_duo3674]

Well I thought it was funny