On 08/03/2010 11:01 PM, David Simcha wrote:
Ok, I've got some more optimizations. I figured out that it's worth trading off some space to make the sin/cos lookup tables be in contiguous memory blocks for all sub-FFTs. I'm now down to ~340 ms on my benchmark, but fresh out of optimization ideas.
I meant to say this after your previous post: function tabulation is not all. What people do is they approximate functions with a few of their Taylor expansion terms, often in conjunction with tables.
For my thesis I needed a fast tanh. I dug up a paper that had some weird formulas depending on the magnitude of the argument. I first built a table and then I interpolated using the formulas in between the table elements. It was a smashing success.
Google for <<fast sine approximation>> or so, there seems to be plenty of good stuff out there.
Andrei _______________________________________________ phobos mailing list [email protected] http://lists.puremagic.com/mailman/listinfo/phobos
