Commit graph

2 commits

Author SHA1 Message Date
John Ericson
f4ab297b31 Ensure all headers have #pragma once and are in API docs
`///@file` makes them show up in the internal API dos. A tiny few were
missing `#pragma once`.
2023-03-31 23:19:44 -04:00
Daniël de Kok
2de232d2b3 Add x86_64 compute levels as additional system types
When performing distributed builds of machine learning packages, it
would be nice if builders without the required SIMD instructions can
be excluded as build nodes.

Since x86_64 has accumulated a large number of different instruction
set extensions, listing all possible extensions would be unwieldy.
AMD, Intel, Red Hat, and SUSE have recently defined four different
microarchitecture levels that are now part of the x86-64 psABI
supplement and will be used in glibc 2.33:

https://gitlab.com/x86-psABIs/x86-64-ABI
https://lwn.net/Articles/844831/

This change uses libcpuid to detect CPU features and then uses them to
add the supported x86_64 levels to the additional system types. For
example on a Ryzen 3700X:

$ ~/aps/bin/nix -vv --version | grep "Additional system"
Additional system types: i686-linux, x86_64-v1-linux, x86_64-v2-linux, x86_64-v3-linux
2021-02-22 09:11:15 +01:00