feat: avx feature switch

[ohaiibuzzle]

Apple: We add a feature!
Also Apple: We also make it 10 layers deep inside the Rosetta 2 binary locked behind an environment variable, good luck!

(Although I think some people found out that AVX support may be incomplete)

[Gcenx]

As this environment variable isn’t documented there’s no telling if/when it’ll be removed.

Also should add a warning about this option as enabling it would cause AVX/2 to be used over a possible SSE2 code path, the AVX/2 code path would be slower than SSE2.

[ohaiibuzzle]

@Gcenx Added a bit of warning for that. We can just remove it if it's no longer needed later

[Gcenx]

@Gcenx Added a bit of warning for that. We can just remove it if it's no longer needed later

Remove emulator wine isn’t emulation

This seems more reasonable

This option may significantly impact performance.

[ohaiibuzzle]

Remove emulator wine isn’t emulation

Wine isn't, but Rosetta is, since it's the one doing x86_64 translation.
So I think using the term emulation might be the correct one here, as it is a R2 environment variable.

[Gcenx]

I’d still remove the term emulation and instead change AVX

AVX support (emulated)

That’s at least then more accurate.

[ohaiibuzzle]

Then probably the best middleground (and to keep it short) would be

AVX Emulation
⚠️ Significantly impacts performance

[Gcenx]

That seems the best compromise

[ultratiem]

“Significantly impacts performance” an impact is merely a strong effect, so significant becomes redundant (like wet water). It doesn’t inherently mean good or bad, so if you want to add a warning that it may adversely affect something, you need to be explicit:

“May negatively impact performance”

From a UX standpoint, you don’t need to scare users. The warning emoji for instance, one wonders why they would ever turn it on let alone why it was even added. Thus it may be better form to simply add (experimental) to the label:

AVX (Experimental)
May negatively impact performance

This lets users know it’s not a feature but simply a testing ground.

[Gcenx]

I disagree the current label and text, maybe minus the icon ensure users will understand turning that option on will have side-effects.

It’s not grammatically incorrect.

Not making this clear will result in it being used like Retina, where users enable it then complain.

[ohaiibuzzle]

@ultratiem I mean, maybe we could brainstrorm something out, but, just fyi
This is how Apple's own goddang OS does it for "side effects":

[xtrime-ru]

Ive tried to set ROSETTA_ADVERTISE_AVX manually in app env variables in bottle, but looks like it is ignored. Is it possible to set this variable without need to build app from source?

[andyoneal]

ROSETTA_ADVERTISE_AVX is now documented in beta 3.

ROSETTA_ADVERTISE_AVX - Defaults to 0 (OFF). On macOS 15 Sequoia, setting this environment variable to 1 (ON) causes the CPU instruction translation layer to publish cpuid information to translated applications when running in the evaluation environment, so games querying instruction set extension capabilities before utilizing them can conditionally control their use of instruction extensions. This setting does not modify the availability of the instruction set in Rosetta; it only controls whether the processor advertises its support for these extensions.