Author: Tony Werten
Date: 00:16:41 09/20/04
Go up one level in this thread
On September 20, 2004 at 03:06:54, Gerd Isenberg wrote:
>On September 20, 2004 at 02:23:59, Tony Werten wrote:
>
>>It isn't doing things parallel like the sliders with Kogge Stone, but at least
>>it doesn't use those big arrays.
>>
>>const KNIGHTC3 // all attacks of a knight on square C3
>>
>>pieces=BITBOARD[stm][KNIGHT];
>>attacks=0;
>>while (pieces)
>>{
>> sq=bitscan_first_and_reset(pieces);
>> File(sq)>2 ? mask=NOT_FILE_AB:mask=NOT_FILE_GH;
>> if (sq>C3) attacks=(KNIGHTC3>>(sq-C3)) & mask;
> <<
correct (when A1=0 and H8=63)
>> else attacks|=(KNIGHTC3<<(C3-sq)) & mask;
> ?? >>
correct. I'm mixing some things here. The |= is for all knight attacks, mostly
you only want =
>>}
>>
>>For king is the same but on square B2. Since most of the time sq>C3 (or B2)
>>branch prediction should be OK.
>
>Even more for sq>=C3 (or b2).
Yeah, that might do some 0.1 % better even :)
Tony
>
>
>>
>>Tony
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