On Mon, Apr 6, 2009 at 2:22 PM, Mark Dickinson <dicki...@gmail.com> wrote: > Well, I'd say that the obvious solution here is to compute > the constant 2.0**53 just once, somewhere outside the > inner loop. In any case, that value would probably be better > written as 2.0**DBL_MANT_DIG (or something similar). > > As Antoine reported, the constant-folding caused quite > a confusing bug report (issue #5593): the problem (when > we eventually tracked it down) was that the folded > constant was in a .pyc file, and so wasn't updated when > the compiler flags changed.
Another way of looking at this is that we have a ./configure option which affects .pyc output. Therefor, we should add a flag to the magic number, causing it to be regenerated as needed. Whether that's better or worse than removing constant folding I haven't decided. I have such low expectations of floating point that I'm not surprised by bugs like this. I'm more surprised that people expect consistent, deterministic results... -- Adam Olsen, aka Rhamphoryncus _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
