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Bitbase index() from ADD to OR. No functional change. #132

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mstembera
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I initially wrote this as a speed optimization but because Intel has done a great job making the ADD instruction with carry as fast as a bitwise OR it is exactly the same speed. I'm submitting it anyway because from a purist point of view the bitwise OR better reflects that the index is a series of bitfields as documented in the comment section instead of a number arrived at through an algebraic expression. Also it might still be faster on more primitive architectures. I realize this is very nit picky so if you don't like it just close the pull request. No functional change.

@lucasart
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agree. or is more self-documenting than add.

@zamar
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zamar commented Nov 25, 2014

Approved.

@glinscott
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Looks good.

@glinscott glinscott closed this in fe07ae4 Nov 25, 2014
niklasf pushed a commit to niklasf/Stockfish that referenced this pull request Nov 28, 2016
Fix detection of final positions in racing kings
Alayan-stk-2 added a commit to Alayan-stk-2/Stockfish that referenced this pull request Feb 27, 2020
…icial-stockfish#132)

Inspired by Vizvezdenec's patch for Stockfish.

ELO   | 3.12 +- 2.45 (95%)
SPRT  | 12.0+0.12s Threads=1 Hash=8MB
LLR   | 3.01 (-2.94, 2.94) [0.00, 5.00]
Games | N: 37600 W: 9351 L: 9013 D: 19236
http://chess.grantnet.us/viewTest/4725/

ELO   | 2.38 +- 1.80 (95%)
SPRT  | 60.0+0.6s Threads=1 Hash=64MB
LLR   | 2.97 (-2.94, 2.94) [0.00, 5.00]
Games | N: 56428 W: 11335 L: 10949 D: 34144
http://chess.grantnet.us/viewTest/4728/

BENCH : 6,225,718
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4 participants