Comment on Why we don't have 128-bit CPUs
Technus@lemmy.zip 4 months agoWe don’t even have true 64-bit addressing yet. x86-64 uses only 48 bits of a 64 bit address and 64-bit ARM can use anything between 40 and 52 depending on the specific configuration.
just_another_person@lemmy.world 4 months ago
MrQuallzin@lemmy.world 4 months ago
I think they were just adding to the conversation
Technus@lemmy.zip 4 months ago
I actually added detail that wasn’t already discussed in the article?
AlphaAutist@lemmy.world 4 months ago
I actually didn’t know that about addressing before your comment and so I found it very interesting, thanks
Technus@lemmy.zip 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.
b34k@lemmy.world 4 months ago
just_another_person@lemmy.world 4 months ago
Technus@lemmy.zip 4 months ago
Jesus Christ, what crawled up your ass and died?
mohammed_alibi@lemmy.world 4 months ago