On Friday, 15 September 2017 at 03:49:02 UTC, Walter Bright wrote:
https://people.eecs.berkeley.edu/~wkahan/UnumSORN.pdf
Prof Kahan, who pretty much invented IEEE 754 floating point
arithmetic, debunks unums. Unums pop up now and then with "why
don't we support them?"
The bottom line is there is no magic solution to floating point
problems. Unums just trade one set of problems for another.
It's hard to know what's going on when there are mistakes in his
examples that lead to wrong behavior. How can be be taken
seriously if his rebuttle has basic mistakes and typos?
https://people.eecs.berkeley.edu/~wkahan/EndErErs.pdf
page 5:
(y - sqrt(y^2 + 1)) - 1/(y + sqrt(y^2 + 1))
is not zero for all y.
I assume he means
(y - sqrt(y^2 + 1)) + 1/(y + sqrt(y^2 + 1))
