[richdodd]

Does the M1/M2 use ARM designs in the GPU as well as the CPU? If so, it might be possible to work out what could be implemented by looking at the [arm docs](https://developer.arm.com/documentation/102203/0100/Valhall-...).

[DeRock]

Apple doesn’t use ARM IP for either, and hasn’t for many years.

[raphlinus]

The most complete documentation is in the applegpu repo[1] by dougallj showing a great deal of recent activity (including by alyssarosenzweig). Last I checked, the documentation of barrier instructions wasn't complete enough to tell whether these device-scoped barriers are possible. (Note: on RDNA2, they're accomplished by DLC and GLC flags on memory accesses, combined with cache flush instructions such as S_GL1_INV).

There's also a lot of great material, accessibly written, on Alyssa's blog[2], see in particular the posts titled "Dissecting the Apple M1 GPU, part ${I}".

[1]: https://github.com/dougallj/applegpu

[2]: https://rosenzweig.io/

[nicoburns]

No, they have a custom GPU design originally derived from Imagination Technologies PowerVR GPUs.

[richdodd]

Hmm OK according to the doucmentation they designed the GPU themselves, so there's no public information on them.