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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 33 | pmbaty | 1 | #include "chess.h" |
| 2 | #include "data.h" |
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| 3 | /* last modified 02/16/14 */ |
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| 4 | /* |
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| 5 | ******************************************************************************* |
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| 6 | * * |
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| 7 | * This group of procedures provide the three basic bitboard operators, * |
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| 8 | * MSB(x) that determines the Most Significant Bit, LSB(x) that determines * |
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| 9 | * the Least Significant Bit, and PopCnt(x) which returns the number of one * |
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| 10 | * bits set in the word. * |
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| 11 | * * |
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| 12 | * We prefer to use hardware facilities (such as intel BSF/BSR) when they * |
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| 13 | * are available, otherwise we resort to C and table lookups to do this in * |
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| 14 | * the most efficient way possible. * |
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| 15 | * * |
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| 16 | ******************************************************************************* |
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| 17 | */ |
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| 18 | #if !defined(INLINEASM) |
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| 19 | int MSB(uint64_t arg1) { |
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| 20 | if (arg1 >> 48) |
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| 21 | return msb[arg1 >> 48] + 48; |
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| 22 | if (arg1 >> 32 & 65535) |
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| 23 | return msb[arg1 >> 32 & 65535] + 32; |
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| 24 | if (arg1 >> 16 & 65535) |
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| 25 | return msb[arg1 >> 16 & 65535] + 16; |
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| 26 | return msb[arg1 & 65535]; |
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| 27 | } |
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| 28 | |||
| 29 | int LSB(uint64_t arg1) { |
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| 30 | if (arg1 & 65535) |
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| 31 | return lsb[arg1 & 65535]; |
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| 32 | if (arg1 >> 16 & 65535) |
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| 33 | return lsb[arg1 >> 16 & 65535] + 16; |
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| 34 | if (arg1 >> 32 & 65535) |
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| 35 | return lsb[arg1 >> 32 & 65535] + 32; |
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| 36 | return lsb[arg1 >> 48] + 48; |
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| 37 | } |
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| 38 | |||
| 39 | int PopCnt(uint64_t arg1) { |
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| 108 | pmbaty | 40 | int c; |
| 41 | |||
| 154 | pmbaty | 42 | for (c = 0; arg1; c++) |
| 43 | arg1 &= arg1 - 1; |
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| 33 | pmbaty | 44 | return c; |
| 45 | } |
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| 46 | #endif |