Author: Bo Persson
Date: 05:04:18 08/04/02
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On August 04, 2002 at 01:23:28, Miguel A. Ballicora wrote: >On August 03, 2002 at 13:57:37, Russell Reagan wrote: > >>On August 03, 2002 at 06:47:20, Bo Persson wrote: >> >>>I have no real use for AllPieces in my program, >> >>I am testing out different ideas, and the only use I can see for all pieces >>bitboard would be to determine if a square is occupied or not. > >Is it not requirement for rotated bitboards to have an allpieces bitboard? >This is one of the rotations, isn'it? Yes, but you don't have to *store* it. Instead of picking one byte from AllPieces, I pick one byte each from LitePieces and DarkPieces, and OR them together. Amazing isn't it! :-) Also, I have recently removed the Rotate90 bitboard as well. I found a new SSE2 instruction (movemask, Pentium 4 only) that extracts the sign bits of each byte in an MMX register. Just shift left by file index and extract. Actually this last bit isn't any faster so far, just more fun. :-) Bo Persson bop2@telia.com
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