this post was submitted on 23 Jun 2024
276 points (94.5% liked)

Technology

59534 readers
3195 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
L3s@lemmy.world
L3s@fry.gs
L4s@fry.gs
L4s@lemmy.world
enu@lemmy.world
276
Why we don't have 128-bit CPUs (www.xda-developers.com)
submitted 5 months ago by jwr1@kbin.earth to c/technology@lemmy.world
123 comments fedilink hide all child comments
you are viewing a single comment's thread
view the rest of the comments
[–] Technus@lemmy.zip 2 points 4 months ago

Some applications use those unused bits to add tags to pointers but it's important to mask those out before attempting to dereference the address. I'm not sure about ARM but x86-64 requires bits 49-63 to be copies of bit 48 (kinda like sign-extension), ironically to ensure that no one is using those bits to store extra data.