Rune Petersen wrote:
> This patch: - Fixes COS. - Does range reductions for SIN & COS. -
> Adds SCS. - removes the optimized version of SIN & COS. - tweaked
> weight (should help on precision). - fixed a copy paste typo in
> emit_arith().
> 
> Roland would you mind testing if the tweaked weight helped?
Well I didn't test it first time (just quoting the numbers from the link
you provided), but I guess that's fine too. I was actually wondering
myself if it's better to optimize for absolute or relative error, so
choosing a weight in-between should work too (the difference is not that
big after all).

A couple comments though:
Since ((x + PI/2)/(2*PI))+0.5 is (x/(2*PI) + (1/4 + 0.5)
you could optimize away the first mad for the COS case.

Also, the comments for SCS seem a bit off. That's a pity, because
without comments I can't really see what the code does at first sight
:-). Looks like quite a few extra instructions though, are you sure not
more could be shared for calculating both sin and cos?

Otherwise, looks good to me. Keep up the good work!

Roland

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