6 ms·

How much code is compiled with `-march=native` or function multiversioning? I would guess the percentage is relatively small, at least when it comes to distribu

by celrod 4y ago

How much code is compiled with `-march=native` or function multiversioning? I would guess the percentage is relatively small, at least when it comes to distributed binaries. Compiler autovectorizers also aren't very good at producing fast AVX512 code, so most of the benefit would probably come from using optimized libraries like Intel's MKL or simdjson.

derefr 4y ago
> How much code is compiled with `-march=native` Any installation of Gentoo is, presumably. (Otherwise, what's the point of compiling it all yourself?) More interestingly, possibly all OEM firmware-installed copies of ChromeOS are -march=native builds as well, given that ChromeOS is based off of a Gentoo upstream.
- celrod 4y ago
  True. I have never gone down the Gentoo rabbit hole. Might be fun to try sometime, but I'd seriously doubt that the time spent compiling would be won back from better performance. Clear Linux is probably a more practical alternative. I used it a couple years ago, and found that they had a lot of avx2 and avx512 versions of random libraries built, with the appropriate ones presumably being loaded based on the hardware. Random glibc math function calls, for example, were much faster on Clear Linux than Arch or Fedora. But development of Clear seems to have stopped, libraries like llvm aren't being updated anymore so the toolchains are outdated. I'd wanted to avoid the blood and sweat of managing my own toolchains, and ironically being on bleeding edge distros (Arch,Fedora,etc) was the way to keep that to a minimum. Next time I reinstall an OS, I'll look at Clear again. Or maybe Guix or Nix. Or maybe use spack for package management on top of some other distro.
  - Thev00d00 4y ago
    When I ran Gentoo I just had the builds running in the background with a really high niceness.

6 ms·

How much code is compiled with `-march=native` or function multiversioning? I would guess the percentage is relatively small, at least when it comes to distribu

by celrod 4y ago

derefr 4y ago
> How much code is compiled with `-march=native` Any installation of Gentoo is, presumably. (Otherwise, what's the point of compiling it all yourself?) More interestingly, possibly all OEM firmware-installed copies of ChromeOS are -march=native builds as well, given that ChromeOS is based off of a Gentoo upstream.
- celrod 4y ago
  True. I have never gone down the Gentoo rabbit hole. Might be fun to try sometime, but I'd seriously doubt that the time spent compiling would be won back from better performance. Clear Linux is probably a more practical alternative. I used it a couple years ago, and found that they had a lot of avx2 and avx512 versions of random libraries built, with the appropriate ones presumably being loaded based on the hardware. Random glibc math function calls, for example, were much faster on Clear Linux than Arch or Fedora. But development of Clear seems to have stopped, libraries like llvm aren't being updated anymore so the toolchains are outdated. I'd wanted to avoid the blood and sweat of managing my own toolchains, and ironically being on bleeding edge distros (Arch,Fedora,etc) was the way to keep that to a minimum. Next time I reinstall an OS, I'll look at Clear again. Or maybe Guix or Nix. Or maybe use spack for package management on top of some other distro.
  - Thev00d00 4y ago
    When I ran Gentoo I just had the builds running in the background with a really high niceness.