X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitbase.cpp;h=cd6a7329724e4260bc1529ca9756e82b8265adb9;hp=752d4f0e79c0b480b56697622c538600ec467951;hb=c40d4e0133d003f6caec8fd3bb0bab21f9298721;hpb=190aea4cdc6e8e165028803be846563da53f9330 diff --git a/src/bitbase.cpp b/src/bitbase.cpp index 752d4f0e..cd6a7329 100644 --- a/src/bitbase.cpp +++ b/src/bitbase.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -26,14 +26,14 @@ namespace { // There are 24 possible pawn squares: the first 4 files and ranks from 2 to 7 - const unsigned IndexMax = 2*24*64*64; // stm * psq * wksq * bksq = 196608 + const unsigned MAX_INDEX = 2*24*64*64; // stm * psq * wksq * bksq = 196608 // Each uint32_t stores results of 32 positions, one per bit - uint32_t KPKBitbase[IndexMax / 32]; + uint32_t KPKBitbase[MAX_INDEX / 32]; // A KPK bitbase index is an integer in [0, IndexMax] range // - // Information is mapped in a way that minimizes number of iterations: + // Information is mapped in a way that minimizes the number of iterations: // // bit 0- 5: white king square (from SQ_A1 to SQ_H8) // bit 6-11: black king square (from SQ_A1 to SQ_H8) @@ -84,20 +84,20 @@ void Bitbases::init_kpk() { unsigned idx, repeat = 1; std::vector db; - db.reserve(IndexMax); + db.reserve(MAX_INDEX); // Initialize db with known win / draw positions - for (idx = 0; idx < IndexMax; ++idx) + for (idx = 0; idx < MAX_INDEX; ++idx) db.push_back(KPKPosition(idx)); // Iterate through the positions until none of the unknown positions can be // changed to either wins or draws (15 cycles needed). while (repeat) - for (repeat = idx = 0; idx < IndexMax; ++idx) + for (repeat = idx = 0; idx < MAX_INDEX; ++idx) repeat |= (db[idx] == UNKNOWN && db[idx].classify(db) != UNKNOWN); // Map 32 results into one KPKBitbase[] entry - for (idx = 0; idx < IndexMax; ++idx) + for (idx = 0; idx < MAX_INDEX; ++idx) if (db[idx] == WIN) KPKBitbase[idx / 32] |= 1 << (idx & 0x1F); }