Re:John Gustafson’s crusade to replace floating point with s...
by vanderZwan on Tuesday July 09, 2019 @10:40AM
(#20392202)
> Most developers prefer
You're free to voice your own opinion, but I take some issue with people asserting theirs as if they speak for "most developers". Especially if it comes from a new account with a name like "Gustafnot". That doesn't exactly scream "unbiased" to me.
Re:John Gustafson’s crusade to replace floating point with s...
by ChrisLomont on Thursday July 11, 2019 @07:07AM
(#20410636)
Having written scientific numerical software for decades, and having been in situations where I want high speed or I want reproducibility, and having worked with hundreds of developers, I agree wholeheartedly with Gustafnot - the vast majority of developers prefer performance over bitwise reproducibility. Lose a few bits here and there, and most don’t care, because they treat floats as fuzzy to begin with (and almost never care about reproducibility since it’s very hard to obtain due to compilers, libraries, etc.) . But slow down code, and they sure notice quickly.
If you really want to claim the opposite, do you have evidence? Or experience that it’s true?
Most developers prefer speed over reproducibility, and are encouraged to use denormal-to-zeros, fast-math optimizations, fused MAC, approximated square root function and whatever else is available to achieve results.
The IEEE754 standard provides a guarantee for deterministic results, and many multi-precision and interval arithmetic libraries depend on this guarantee to be true to function properly.
IEEE754 defines unique -infinity and +infinity values, and any "new and improved" standard that breaks this axiom is just incompatible with all existing floating-point libraries written in the last +30 years.
"These claims pander to Ignorance and Wishful Thinking." Kahan (main author of IEEE754) on Posits claims.