official-stockfish/Stockfish — pull request #158 by mstembera (2014-12-13 09:27:58+00:00)
Title: TT replace speed optimization.  Replaces some algebra with logic.  Idea ...

...came from

https://github.com/mcostalba/Stockfish/pull/187

Interestingly changing
if ((!A && (B || C)) || (B && C))
to
if ((!A & (B | C)) | (B & C))
is also possible but maybe a tiny tiny bit slower.

gcc 4.9.1
build ARCH=x86-64-modern
i7 mobile Windows7-64

Results for 50 tests for each version:

Base Test Diff
Mean 511309 516602 -5293
StDev 12016 12075 2359

p-value: 0.988

No functional change.

Can someone else please run fishbench?