3 ms·
No, it does not. There's plenty of subtle implementation differences between x86 CPUs of the same manufacturer. Usually different generations, but it's enough t
by Subsentient 5y ago
No, it does not. There's plenty of subtle implementation differences between x86 CPUs of the same manufacturer. Usually different generations, but it's enough to mess up meteorology.
- alkonaut 5y agoCan you give any examples of where two different CPUs have different or non IEEE compliant behavior (disregarding things like actual bugs or atypical settings)? Let’s say for regular x64 code and SSE FP. I’m surprised you say it’s common as I haven’t yet bumped into the problem and I have a large suite of complex FP tests (engineering calculations) that have reproduced to the last digit over 15 years and dozens of different test machines of all flavors. Results calculated 2004 on P4’s still work out to the same results after millions of calculations on every cpu since then and dozens of versions of the software.
- CodesInChaos 5y agoWhich instructions are you using? I'd trust basic arithmetic, but I wouldn't trust functions like sine (AFAIK the standard fully specifies the former, but not the latter).
- alkonaut 5y agoThere’s lots of trig. But as far as I’m aware those have also been identical in SSE. Edit: SSE actually do transcendentals at all so it’s possible I’m saved by stable software defined transcendentals in .net (effectively then the Windows x64 implementations)