Torture tests: what do they mean?

[HP67]

(05-15-2014 11:37 AM)Paul Dale Wrote:  If I had to suggest one resouce, I'd go for William Kahan's writings as a good general introduction. I can't suggest just one of the books I referenced.

Thank you, I downloaded several papers. Looks like a great resource.

(05-15-2014 11:37 AM)Paul Dale Wrote:  Mike Colishaw's Floating Point Decimal Pages pages link to his decimal floating point library which is the basis of the 34S's numerics. There actually has quite a bit of recent development work on hardware decimal floating point arithmetic. Several processors are moving to support it natively. IBM's power cpus are beginning too and I believe Intel is working on this too.

Since I work on IBM mainframes (although in non-numerical systems) I have been aware of some of Colishaw's work since the 1970s. He is the father of the REXX language in addition to a lot of other neat stuff. Decimal floating point has been available on IBM hardware for a while (I just found an IBM hardware announcement from 2007 that mentions the 64 and 128 bit hardware support on System Z for decimal floating point, so that would be right about 7 years. I don't know if that was the first time it was supported or not, though) and IEEE binary FP has been supported since the late 1990s IIRC. All this in addition to IBM's native 64 and 128 bit hex FP from the S/360 days in the late 1960s. There is no shortage of fun stuff do to if you can afford a new z/Arch box and the software etc. etc. etc. to go with it!

I am glad to hear DFP is moving to other platforms because I have seen way too many threads on other forums and mailing lists where people are using binary floating point for money calculations and have no idea why that is usually not a good idea.