Carl Witty wrote: > On Mon, Apr 6, 2009 at 10:15 AM, Stefan Behnel wrote: >> should we enable constant folding for floats by using the decimal module? > > I don't think so. > > 1) Is there any advantage to doing constant folding in Cython instead > of letting the C compiler do it?
Well, yes. In many situations, Cython can use values that are known at compile time to generate simpler code, e.g. avoid Python type conversions or move code sections into C completely. Loops are a great example. Cython 0.12 will bring another couple of enhancements here. Not sure if this really applies to float values, so we might end up postponing this discussion until there is a concrete reason to enable this. > 2) If I write a constant floating-point expression, I expect it to be > evaluated according to IEEE rounding rules. (So I would prefer doing > the constant folding using Python floats, which will usually match the > computations performed in the target, rather than the decimal module, > which won't match the target.) Makes sense to me. Stefan _______________________________________________ Cython-dev mailing list [email protected] http://codespeak.net/mailman/listinfo/cython-dev
