On Apr 29, 12:16 pm, mabshoff <[EMAIL PROTECTED] dortmund.de> wrote: > On Apr 29, 1:54 am, Francois <[EMAIL PROTECTED]> wrote: > > > On Apr 29, 11:33 am, mabshoff <[EMAIL PROTECTED] > > Hi Francois, > > > Hi Michael, > > > The latest upstream release has the same default. > > Ok. > > >I try to get what upstream > > offers and I didn't see any archives of old release like the one used > > in sage. > > What about "sloppy" mult and div? I don't really have any benchmarks > > to offer > > we should ask upstream about the gains and loses. > > We should fix either issue, even if we were to pay some penalty since > correctness is more important than speed. Getting wrong results faster > is kind of pointless. > > > Francois > > Once you get some answer from upstream please open a ticket. I find it > odd that the defaults are this way to say the least. > I did email the author about the precision here is what he has to say:
For ieee-add, it all depends on what kind of error bound you need. If enabled, the error satisfies |e| <= |a+b| * epsilon It not enabled, the error satisfies |e| <= epsilon * max (|a|, |b|) For most uses the second one is just fine, but some times one needs the first one. Sloppy-mul and sloppy div usually degrades by few bits, so maybe you lose a digit of accuracy. For double-double, the degredation is smaller. ================ The answer is not qualified by processors. He didn't say anything about performance (I asked). --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
