Alternative formula for dynamic contempt
authorceebo <chricainogithub@gmail.com>
Mon, 23 Apr 2018 07:13:07 +0000 (09:13 +0200)
committerStéphane Nicolet <cassio@free.fr>
Mon, 23 Apr 2018 07:13:27 +0000 (09:13 +0200)
commitaef7076c344881954b4f586bd4779594d0b29037
treebab5ad4c8ad3c218ab3709965964e44095ff6ffb
parenta64d524d026bc78e4779fa3249649271d905df2d
Alternative formula for dynamic contempt

Replace the formula involving arctan with something having similar
behaviour that can be implemented using integer-only operations.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 34781 W: 7189 L: 7093 D: 20499
http://tests.stockfishchess.org/tests/view/5ad7c95f0ebc595700526e76

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 39743 W: 5950 L: 5857 D: 27936
http://tests.stockfishchess.org/tests/view/5ad886ee0ebc595700526e9b

Closes https://github.com/official-stockfish/Stockfish/pull/1558

Bench: 5549801
src/search.cpp