alt Hacker NewsGP seems to think it strange that "x86" would actually not have a performance difference here.
I think this might just be due to not realizing just how far back in CPU history this goes.
GP seems to think it strange that "x86" would actually not have a performance difference here.
I think this might just be due to not realizing just how far back in CPU history this goes.
In a clockless cpu design you'd indeed expect xor to be faster. But in a regular CPU with a clock you either waste a bit of xor performance by making xor and sub both take the same number of ticks, or you speed up the clock enough that the speed difference between xor and sub justifies sub being at least a full tick slower
The former just seems way more practical