That still exists though? add rax, rbx/jo overflow_error is how you do overflow ... | Hacker News

Hacker Newsnew | past | comments | ask | show | jobs | submit

		gsg on Sept 24, 2020 \| parent \| context \| favorite \| on: How expensive is integer-overflow trapping in C++? That still exists though? add rax, rbx/jo overflow_error is how you do overflow checking on x86-64.

chrisseaton on Sept 24, 2020 [–]

That doesn’t work with a lot of arithmetic, so you have to use slower arithmetic in order to use it.

gsg on Sept 24, 2020 | [–]

Sure, but that didn't change much between x86 and x86-64. Perhaps it got a little worse because the SIMD instructions aren't overflow check friendly.

Consider applying for YC's Summer 2026 batch! Applications are open till May 4
Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact