Re: Parsing timestamps?

On 10/07/2025 2:35 pm, Paul Rubin wrote:

dxf <dxforth@gmail.com> writes:

I suspect IEEE simply standardized what had become common practice among
implementers.

 
No, it was really new and interesting. 
https://people.eecs.berkeley.edu/~wkahan/ieee754status/754story.html
 

What little I know about SSE2 it's not as well thought out or organized
as Intel's original effort.  E.g. doing something as simple as changing
sign of an fp number is a pain when NANs are factored in.

 
I wonder if later SSE/AVX/whatever versions fixed this stuff.

Actually I was wrong.  x87 FCHS (aka FNEGATE) changes the sign bit of a NAN.
IEEE doesn't consider NANs to be signed even though x87 implementations may
display them that way.  The catch with SSE is there's nothing like FCHS or FABS
so depending on how one implements them, results vary across implementations.