this post was submitted on 13 Feb 2024
587 points (97.3% liked)

Technology

59622 readers
2845 users here now

This is a most excellent place for technology news and articles.


Our Rules


  1. Follow the lemmy.world rules.
  2. Only tech related content.
  3. Be excellent to each another!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, to ask if your bot can be added please contact us.
  9. Check for duplicates before posting, duplicates may be removed

Approved Bots


founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 2 points 9 months ago

That's pretty much exactly how it works already. You compile with -march=x86-64-v4 and it'll use SSE and AVX all over the place.

glibc does the runtime thing, but only once on application startup where the dynamic linker will link the version of the function optimized for your CPU. But it's a manual process on glibc's part, the variants are written by hand.

Not every project cares enough to do it dynamically like that and it would be a nightmare that way.

The fallback is, recompile with -march=x86-64 which will only use the base set of instructions. Or -march=i486 if you want to run on absolutely ancient hardware.