Metal Quadgroups Example Usage

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Created Jan ’22

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I've started working with simdgroups and as I was looking through the MSL documentation I noticed that there exists, in addition to simdgroups, quadgroups. The shading language documentation merely states that

A quad-group function is a SIMD-group function (see section 6.9.2) with an execution width of 4.

However, it doesn't appear there's a clear reason for using quadgroups over simdgroups, and I have yet to find demonstrations of using quadgroups within a compute kernel.

What are quadgroups and how are they used in conjunction with/replacement of simdgroups?

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maxwellpirtle OP

Jan ’22

I found the tech talk "Discover advances in A15 Bionic" which describes one use case of quadgroups and quadgroup functions at around the 21:00 minute mark where they're used to reduce texture reads. If anyone has any other use cases let us know.

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