On Mon, Jan 02, 2012 at 09:30:56PM -0500, Paul Davis wrote: > On Mon, Jan 2, 2012 at 9:17 PM, Fons Adriaensen <[email protected]> wrote: > > > I don't agree with blaming the Intel architecture. Denormals are > > just one tiny aspect of a much wider issue which is numerical > > precision and stability, and that affects all architectures. > > Anyone writing numerical or DSP code should be aware of this > > and be able to analyse the algorithm. You don't produce good > > numerical or DSP code by blindly implementing textbook equations. > > absolutely. > > but there are two aspects to this issue: > > (1) good numerical or DSP code > (2) not slowing the processor down by a factor of 10 or more > > non-Intel architectures took care of (2), while leaving (1) for the > programmer to tackle.
Again I don't agree these are two different issues. 'Taking care of (2)' may avoid the slowdown, but it may also hide the real problem, which is that you are trying to do a computation that is beyond the limits of what the FPU can do. And that problem is *not* solved by ensuring there will be no slowdown. In some cases replacing small values (of which denormals are just one form) by zero or adding a small bias may help. In other cases it doesn't and it just produces new problems. Such a method is no substitute for analysis, not any more than blindly changing floats into doubles and hoping for the best. Ciao, -- FA Vor uns liegt ein weites Tal, die Sonne scheint - ein Glitzerstrahl. _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
