On 07/16/13 14:57, Guy Steele wrote:
So instead I took the latest version and modified the generation of gamma values to use a 56-bit GAMMA_GAMMA value and perform arithmetic modulo 2^56-5 ...
So here's the punchline: this change makes my Monte Carlo calculation of pi run over 19% faster! Hard to believe. It's certainly avoiding most of the hard work in addGammaModGeorge, and perhaps also making branch prediction totally win, but 19% ??? Someone please verify this independently.
I tried this on a few other simple tests and I see varying improvements on different machines from about 8% to 15%. So this does seem worth pursuing. (Aside to casual observers on this list: Sometimes it does pay off to obsess so much over a couple of "if" statements.) -Doug
