Optimisation logbook

A list of optimisation decisions and their effect on performances.

2011/09/02

Started importing Ryan Sammartino's PS3 trigonometry library in the core ([885] [886] and [888]).

• do the Taylor series on x / π instead of x ([890]): results in a measurable 2% speed increase in sin() (ppu-lv2-g++)
• do the Taylor series in two steps, for better pipelining at the cost of one extra multiplication ([891]): a notable 11% speed increase in sin() (ppu-lv2-g++)