From d632e77058114e87a6d7c02fda3a40768546e1d6 Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Tue, 7 Jun 2011 15:12:07 +0200 Subject: [PATCH] Find magics on the fly Good result for 32 bit case where computation is very fast, still not satisfying on 64 bit case where the magics seem a bit harder to get. No functional change. Signed-off-by: Marco Costalba --- src/bitboard.cpp | 211 +++++++++++++++++------------------------------ src/bitboard.h | 4 +- 2 files changed, 77 insertions(+), 138 deletions(-) diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 88682948..8c70a8e2 100644 --- a/src/bitboard.cpp +++ b/src/bitboard.cpp @@ -17,18 +17,22 @@ along with this program. If not, see . */ +#include #include #include "bitboard.h" #include "bitcount.h" +#include "rkiss.h" // Global bitboards definitions with static storage duration are // automatically set to zero before enter main(). Bitboard RMask[64]; +Bitboard RMult[64]; Bitboard* RAttacks[64]; int RShift[64]; Bitboard BMask[64]; +Bitboard BMult[64]; Bitboard* BAttacks[64]; int BShift[64]; @@ -53,117 +57,6 @@ Bitboard QueenPseudoAttacks[64]; uint8_t BitCount8Bit[256]; -#if defined(IS_64BIT) - -static const uint64_t DeBruijnMagic = 0x218A392CD3D5DBFULL; - -const uint64_t BMult[64] = { - 0x0440049104032280ULL, 0x1021023C82008040ULL, 0x0404040082000048ULL, - 0x48C4440084048090ULL, 0x2801104026490000ULL, 0x4100880442040800ULL, - 0x0181011002E06040ULL, 0x9101004104200E00ULL, 0x1240848848310401ULL, - 0x2000142828050024ULL, 0x00001004024D5000ULL, 0x0102044400800200ULL, - 0x8108108820112000ULL, 0xA880818210C00046ULL, 0x4008008801082000ULL, - 0x0060882404049400ULL, 0x0104402004240810ULL, 0x000A002084250200ULL, - 0x00100B0880801100ULL, 0x0004080201220101ULL, 0x0044008080A00000ULL, - 0x0000202200842000ULL, 0x5006004882D00808ULL, 0x0000200045080802ULL, - 0x0086100020200601ULL, 0xA802080A20112C02ULL, 0x0080411218080900ULL, - 0x000200A0880080A0ULL, 0x9A01010000104000ULL, 0x0028008003100080ULL, - 0x0211021004480417ULL, 0x0401004188220806ULL, 0x00825051400C2006ULL, - 0x00140C0210943000ULL, 0x0000242800300080ULL, 0x00C2208120080200ULL, - 0x2430008200002200ULL, 0x1010100112008040ULL, 0x8141050100020842ULL, - 0x0000822081014405ULL, 0x800C049E40400804ULL, 0x4A0404028A000820ULL, - 0x0022060201041200ULL, 0x0360904200840801ULL, 0x0881A08208800400ULL, - 0x0060202C00400420ULL, 0x1204440086061400ULL, 0x0008184042804040ULL, - 0x0064040315300400ULL, 0x0C01008801090A00ULL, 0x0808010401140C00ULL, - 0x04004830C2020040ULL, 0x0080005002020054ULL, 0x40000C14481A0490ULL, - 0x0010500101042048ULL, 0x1010100200424000ULL, 0x0000640901901040ULL, - 0x00000A0201014840ULL, 0x00840082AA011002ULL, 0x010010840084240AULL, - 0x0420400810420608ULL, 0x8D40230408102100ULL, 0x4A00200612222409ULL, - 0x0A08520292120600ULL -}; - -const uint64_t RMult[64] = { - 0x0A8002C000108020ULL, 0x4440200140003000ULL, 0x8080200010011880ULL, - 0x0380180080141000ULL, 0x1A00060008211044ULL, 0x410001000A0C0008ULL, - 0x9500060004008100ULL, 0x0100024284A20700ULL, 0x0000802140008000ULL, - 0x0080C01002A00840ULL, 0x0402004282011020ULL, 0x9862000820420050ULL, - 0x0001001448011100ULL, 0x6432800200800400ULL, 0x040100010002000CULL, - 0x0002800D0010C080ULL, 0x90C0008000803042ULL, 0x4010004000200041ULL, - 0x0003010010200040ULL, 0x0A40828028001000ULL, 0x0123010008000430ULL, - 0x0024008004020080ULL, 0x0060040001104802ULL, 0x00582200028400D1ULL, - 0x4000802080044000ULL, 0x0408208200420308ULL, 0x0610038080102000ULL, - 0x3601000900100020ULL, 0x0000080080040180ULL, 0x00C2020080040080ULL, - 0x0080084400100102ULL, 0x4022408200014401ULL, 0x0040052040800082ULL, - 0x0B08200280804000ULL, 0x008A80A008801000ULL, 0x4000480080801000ULL, - 0x0911808800801401ULL, 0x822A003002001894ULL, 0x401068091400108AULL, - 0x000004A10A00004CULL, 0x2000800640008024ULL, 0x1486408102020020ULL, - 0x000100A000D50041ULL, 0x00810050020B0020ULL, 0x0204000800808004ULL, - 0x00020048100A000CULL, 0x0112000831020004ULL, 0x0009000040810002ULL, - 0x0440490200208200ULL, 0x8910401000200040ULL, 0x6404200050008480ULL, - 0x4B824A2010010100ULL, 0x04080801810C0080ULL, 0x00000400802A0080ULL, - 0x8224080110026400ULL, 0x40002C4104088200ULL, 0x01002100104A0282ULL, - 0x1208400811048021ULL, 0x3201014A40D02001ULL, 0x0005100019200501ULL, - 0x0101000208001005ULL, 0x0002008450080702ULL, 0x001002080301D00CULL, - 0x410201CE5C030092ULL -}; - -#else // if !defined(IS_64BIT) - -static const uint32_t DeBruijnMagic = 0x783A9B23; - -const uint64_t BMult[64] = { - 0x54142844C6A22981ULL, 0x710358A6EA25C19EULL, 0x704F746D63A4A8DCULL, - 0xBFED1A0B80F838C5ULL, 0x90561D5631E62110ULL, 0x2804260376E60944ULL, - 0x84A656409AA76871ULL, 0xF0267F64C28B6197ULL, 0x70764EBB762F0585ULL, - 0x92AA09E0CFE161DEULL, 0x41EE1F6BB266F60EULL, 0xDDCBF04F6039C444ULL, - 0x5A3FAB7BAC0D988AULL, 0xD3727877FA4EAA03ULL, 0xD988402D868DDAAEULL, - 0x812B291AFA075C7CULL, 0x94FAF987B685A932ULL, 0x3ED867D8470D08DBULL, - 0x92517660B8901DE8ULL, 0x2D97E43E058814B4ULL, 0x880A10C220B25582ULL, - 0xC7C6520D1F1A0477ULL, 0xDBFC7FBCD7656AA6ULL, 0x78B1B9BFB1A2B84FULL, - 0x2F20037F112A0BC1ULL, 0x657171EA2269A916ULL, 0xC08302B07142210EULL, - 0x0880A4403064080BULL, 0x3602420842208C00ULL, 0x852800DC7E0B6602ULL, - 0x595A3FBBAA0F03B2ULL, 0x9F01411558159D5EULL, 0x2B4A4A5F88B394F2ULL, - 0x4AFCBFFC292DD03AULL, 0x4A4094A3B3F10522ULL, 0xB06F00B491F30048ULL, - 0xD5B3820280D77004ULL, 0x8B2E01E7C8E57A75ULL, 0x2D342794E886C2E6ULL, - 0xC302C410CDE21461ULL, 0x111F426F1379C274ULL, 0xE0569220ABB31588ULL, - 0x5026D3064D453324ULL, 0xE2076040C343CD8AULL, 0x93EFD1E1738021EEULL, - 0xB680804BED143132ULL, 0x44E361B21986944CULL, 0x44C60170EF5C598CULL, - 0xF4DA475C195C9C94ULL, 0xA3AFBB5F72060B1DULL, 0xBC75F410E41C4FFCULL, - 0xB51C099390520922ULL, 0x902C011F8F8EC368ULL, 0x950B56B3D6F5490AULL, - 0x3909E0635BF202D0ULL, 0x5744F90206EC10CCULL, 0xDC59FD76317ABBC1ULL, - 0x881C7C67FCBFC4F6ULL, 0x47CA41E7E440D423ULL, 0xEB0C88112048D004ULL, - 0x51C60E04359AEF1AULL, 0x1AA1FE0E957A5554ULL, 0xDD9448DB4F5E3104ULL, - 0xDC01F6DCA4BEBBDCULL, -}; - -const uint64_t RMult[64] = { - 0xD7445CDEC88002C0ULL, 0xD0A505C1F2001722ULL, 0xE065D1C896002182ULL, - 0x9A8C41E75A000892ULL, 0x8900B10C89002AA8ULL, 0x9B28D1C1D60005A2ULL, - 0x015D6C88DE002D9AULL, 0xB1DBFC802E8016A9ULL, 0x149A1042D9D60029ULL, - 0xB9C08050599E002FULL, 0x132208C3AF300403ULL, 0xC1000CE2E9C50070ULL, - 0x9D9AA13C99020012ULL, 0xB6B078DAF71E0046ULL, 0x9D880182FB6E002EULL, - 0x52889F467E850037ULL, 0xDA6DC008D19A8480ULL, 0x468286034F902420ULL, - 0x7140AC09DC54C020ULL, 0xD76FFFFA39548808ULL, 0xEA901C4141500808ULL, - 0xC91004093F953A02ULL, 0x02882AFA8F6BB402ULL, 0xAEBE335692442C01ULL, - 0x0E904A22079FB91EULL, 0x13A514851055F606ULL, 0x76C782018C8FE632ULL, - 0x1DC012A9D116DA06ULL, 0x3C9E0037264FFFA6ULL, 0x2036002853C6E4A2ULL, - 0xE3FE08500AFB47D4ULL, 0xF38AF25C86B025C2ULL, 0xC0800E2182CF9A40ULL, - 0x72002480D1F60673ULL, 0x2500200BAE6E9B53ULL, 0xC60018C1EEFCA252ULL, - 0x0600590473E3608AULL, 0x46002C4AB3FE51B2ULL, 0xA200011486BCC8D2ULL, - 0xB680078095784C63ULL, 0x2742002639BF11AEULL, 0xC7D60021A5BDB142ULL, - 0xC8C04016BB83D820ULL, 0xBD520028123B4842ULL, 0x9D1600344AC2A832ULL, - 0x6A808005631C8A05ULL, 0x604600A148D5389AULL, 0xE2E40103D40DEA65ULL, - 0x945B5A0087C62A81ULL, 0x012DC200CD82D28EULL, 0x2431C600B5F9EF76ULL, - 0xFB142A006A9B314AULL, 0x06870E00A1C97D62ULL, 0x2A9DB2004A2689A2ULL, - 0xD3594600CAF5D1A2ULL, 0xEE0E4900439344A7ULL, 0x89C4D266CA25007AULL, - 0x3E0013A2743F97E3ULL, 0x0180E31A0431378AULL, 0x3A9E465A4D42A512ULL, - 0x98D0A11A0C0D9CC2ULL, 0x8E711C1ABA19B01EULL, 0x8DCDC836DD201142ULL, - 0x5AC08A4735370479ULL, -}; - -#endif // defined(IS_64BIT) - - namespace { CACHE_LINE_ALIGNMENT @@ -172,8 +65,8 @@ namespace { Bitboard RAttacksTable[0x19000]; Bitboard BAttacksTable[0x1480]; - void init_sliding_attacks(Bitboard attacksTable[], Bitboard* attacks[], Bitboard mask[], - int shift[], const Bitboard mult[], Square deltas[]); + void do_magics(Bitboard magic[], Bitboard* attack[], Bitboard attTabl[], + Bitboard mask[], int shift[], Square deltas[]); } @@ -201,13 +94,13 @@ void print_bitboard(Bitboard b) { #if defined(IS_64BIT) && !defined(USE_BSFQ) Square first_1(Bitboard b) { - return Square(BSFTable[((b & -b) * DeBruijnMagic) >> 58]); + return Square(BSFTable[((b & -b) * 0x218A392CD3D5DBFULL) >> 58]); } Square pop_1st_bit(Bitboard* b) { Bitboard bb = *b; *b &= (*b - 1); - return Square(BSFTable[((bb & -bb) * DeBruijnMagic) >> 58]); + return Square(BSFTable[((bb & -bb) * 0x218A392CD3D5DBFULL) >> 58]); } #elif !defined(USE_BSFQ) @@ -215,7 +108,7 @@ Square pop_1st_bit(Bitboard* b) { Square first_1(Bitboard b) { b ^= (b - 1); uint32_t fold = unsigned(b) ^ unsigned(b >> 32); - return Square(BSFTable[(fold * DeBruijnMagic) >> 26]); + return Square(BSFTable[(fold * 0x783A9B23) >> 26]); } // Use type-punning @@ -242,12 +135,12 @@ Square pop_1st_bit(Bitboard* bb) { if (u.dw.l) { - ret = Square(BSFTable[((u.dw.l ^ (u.dw.l - 1)) * DeBruijnMagic) >> 26]); + ret = Square(BSFTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783A9B23) >> 26]); u.dw.l &= (u.dw.l - 1); *bb = u.b; return ret; } - ret = Square(BSFTable[((~(u.dw.h ^ (u.dw.h - 1))) * DeBruijnMagic) >> 26]); + ret = Square(BSFTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783A9B23) >> 26]); u.dw.h &= (u.dw.h - 1); *bb = u.b; return ret; @@ -310,10 +203,10 @@ void init_bitboards() { Bitboard b = 1ULL << i; b ^= b - 1; b ^= b >> 32; - BSFTable[uint32_t(b * DeBruijnMagic) >> 26] = i; + BSFTable[uint32_t(b * 0x783A9B23) >> 26] = i; } else - BSFTable[((1ULL << i) * DeBruijnMagic) >> 58] = i; + BSFTable[((1ULL << i) * 0x218A392CD3D5DBFULL) >> 58] = i; int steps[][9] = { {0}, {7,9,0}, {17,15,10,6,-6,-10,-15,-17,0}, {0}, {0}, {0}, {9,7,-7,-9,8,1,-1,-8,0} @@ -333,8 +226,8 @@ void init_bitboards() { Square RDeltas[] = { DELTA_N, DELTA_E, DELTA_S, DELTA_W }; Square BDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW }; - init_sliding_attacks(RAttacksTable, RAttacks, RMask, RShift, RMult, RDeltas); - init_sliding_attacks(BAttacksTable, BAttacks, BMask, BShift, BMult, BDeltas); + do_magics(BMult, BAttacks, BAttacksTable, BMask, BShift, BDeltas); + do_magics(RMult, RAttacks, RAttacksTable, RMask, RShift, RDeltas); for (Square s = SQ_A1; s <= SQ_H8; s++) { @@ -396,31 +289,77 @@ namespace { return attacks; } - void init_sliding_attacks(Bitboard attacksTable[], Bitboard* attacks[], Bitboard mask[], - int shift[], const Bitboard mult[], Square deltas[]) { + template + Bitboard pick_magic(Bitboard mask, RKISS& rk, int booster) { - Bitboard occupancy, index, excluded; - int maxKey, offset = 0; + Bitboard magic; + int lsb; + + if (!Is64) + lsb = first_1(mask); + + // Advance PRNG state of a quantity known to be the optimal to + // quickly retrieve all the magics. + for (int i = 0; i < booster; i++) + rk.rand(); + + while (true) + { + magic = rk.rand() & rk.rand(); + magic &= Is64 ? rk.rand() : (rk.rand() | rk.rand()); + + if ( BitCount8Bit[(mask * magic) >> 56] >= 6 + && (Is64 || BitCount8Bit[(lsb * magic) >> 56])) + return magic; + } + } + + void do_magics(Bitboard magic[], Bitboard* attack[], Bitboard attTabl[], + Bitboard mask[], int shift[], Square deltas[]) { + + const int MagicBoosters32[] = { 43, 53, 76, 17, 51, 65, 55, 23 }; + const int MagicBoosters64[] = { 26, 21, 21, 32, 31, 9, 5, 11 }; + + RKISS rk; + Bitboard occupancy[4096], proofs[4096], excluded; + int key, maxKey, index, booster, offset = 0; for (Square s = SQ_A1; s <= SQ_H8; s++) { excluded = ((Rank1BB | Rank8BB) & ~rank_bb(s)) | ((FileABB | FileHBB) & ~file_bb(s)); - attacks[s] = &attacksTable[offset]; - mask[s] = sliding_attacks(s, EmptyBoardBB, deltas, excluded); - shift[s] = (CpuIs64Bit ? 64 : 32) - count_1s(mask[s]); + attack[s] = &attTabl[offset]; + mask[s] = sliding_attacks(s, EmptyBoardBB, deltas, excluded); + shift[s] = (CpuIs64Bit ? 64 : 32) - count_1s(mask[s]); - maxKey = 1 << count_1s(mask[s]); + maxKey = 1 << count_1s(mask[s]); + booster = CpuIs64Bit ? MagicBoosters64[square_rank(s)] : MagicBoosters32[square_rank(s)]; - for (int key = 0; key < maxKey; key++) + // First compute occupancy and attacks for square 's' + for (key = 0; key < maxKey; key++) { - occupancy = submask(mask[s], key); + occupancy[key] = submask(mask[s], key); + proofs[key] = sliding_attacks(s, occupancy[key], deltas, EmptyBoardBB); + } - index = CpuIs64Bit ? occupancy * mult[s] - : unsigned(occupancy * mult[s] ^ (occupancy >> 32) * (mult[s] >> 32)); + // Then find a possible magic and corresponding attacks + do { + magic[s] = pick_magic(mask[s], rk, booster); + memset(attack[s], 0, maxKey * sizeof(Bitboard)); + + for (key = 0; key < maxKey; key++) + { + index = CpuIs64Bit ? unsigned((occupancy[key] * magic[s]) >> shift[s]) + : unsigned(occupancy[key] * magic[s] ^ (occupancy[key] >> 32) * (magic[s] >> 32)) >> shift[s]; + + if (!attack[s][index]) + attack[s][index] = proofs[key]; + + else if (attack[s][index] != proofs[key]) + break; + } + } while (key != maxKey); - attacks[s][index >> shift[s]] = sliding_attacks(s, occupancy, deltas, EmptyBoardBB); - } offset += maxKey; } } diff --git a/src/bitboard.h b/src/bitboard.h index 404178dc..0177df8c 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -60,12 +60,12 @@ extern Bitboard SquaresInFrontMask[2][64]; extern Bitboard PassedPawnMask[2][64]; extern Bitboard AttackSpanMask[2][64]; -extern const uint64_t RMult[64]; +extern uint64_t RMult[64]; extern int RShift[64]; extern Bitboard RMask[64]; extern Bitboard* RAttacks[64]; -extern const uint64_t BMult[64]; +extern uint64_t BMult[64]; extern int BShift[64]; extern Bitboard BMask[64]; extern Bitboard* BAttacks[64]; -- 2.39.2