X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=ef456307cafbacb4479a53627a7a1d7b58aa362d;hp=3d98c0124a512c0c843ea7f728138d3b370e48fb;hb=ddccb5355cabb7d1a9bf2c0fe3c51b3da0234260;hpb=6933f05f4b1b7b1bd2c072029bf5a06cbeac5b0b diff --git a/src/pawns.cpp b/src/pawns.cpp index 3d98c012..ef456307 100644 --- a/src/pawns.cpp +++ b/src/pawns.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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 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 @@ -24,6 +24,7 @@ #include "bitcount.h" #include "pawns.h" #include "position.h" +#include "thread.h" namespace { @@ -62,33 +63,33 @@ namespace { // Weakness of our pawn shelter in front of the king by [distance from edge][rank] const Value ShelterWeakness[][RANK_NB] = { - { V(101), V(10), V(24), V(68), V(90), V( 95), V(102) }, - { V(105), V( 1), V(30), V(76), V(95), V(100), V(105) }, - { V( 99), V( 0), V(32), V(72), V(92), V(101), V(100) }, - { V( 94), V( 1), V(31), V(68), V(89), V( 98), V(106) } }; + { V( 99), V(20), V(26), V(54), V(85), V( 92), V(108) }, + { V(117), V( 1), V(27), V(71), V(94), V(104), V(118) }, + { V(104), V( 4), V(51), V(76), V(82), V(102), V( 97) }, + { V( 80), V(12), V(43), V(65), V(88), V( 91), V(115) } }; // Danger of enemy pawns moving toward our king by [type][distance from edge][rank] const Value StormDanger[][4][RANK_NB] = { - { { V( 0), V( 61), V( 128), V(47), V(27) }, - { V( 0), V( 66), V( 131), V(49), V(27) }, - { V( 0), V( 62), V( 126), V(52), V(23) }, - { V( 0), V( 63), V( 128), V(52), V(26) } }, - { { V(25), V( 33), V( 95), V(39), V(21) }, - { V(24), V( 33), V( 97), V(42), V(22) }, - { V(24), V( 33), V( 93), V(35), V(23) }, - { V(26), V( 27), V( 96), V(37), V(22) } }, - { { V( 0), V( 0), V( 80), V(14), V( 8) }, - { V( 0), V( 0), V( 163), V(28), V(12) }, - { V( 0), V( 0), V( 163), V(25), V(15) }, - { V( 0), V( 0), V( 161), V(24), V(14) } }, - { { V( 0), V(-300), V(-300), V(54), V(23) }, - { V( 0), V( 67), V( 128), V(46), V(24) }, - { V( 0), V( 64), V( 130), V(50), V(29) }, - { V( 0), V( 63), V( 127), V(51), V(24) } } }; + { { V( 0), V( 65), V( 126), V(36), V(30) }, + { V( 0), V( 55), V( 135), V(36), V(23) }, + { V( 0), V( 47), V( 116), V(45), V(26) }, + { V( 0), V( 62), V( 127), V(57), V(34) } }, + { { V(21), V( 45), V( 93), V(50), V(19) }, + { V(23), V( 24), V( 105), V(41), V(13) }, + { V(23), V( 36), V( 101), V(38), V(20) }, + { V(30), V( 19), V( 110), V(41), V(27) } }, + { { V( 0), V( 0), V( 81), V(14), V( 4) }, + { V( 0), V( 0), V( 169), V(30), V( 3) }, + { V( 0), V( 0), V( 168), V(24), V( 5) }, + { V( 0), V( 0), V( 162), V(26), V(10) } }, + { { V( 0), V(-283), V(-298), V(57), V(29) }, + { V( 0), V( 63), V( 137), V(42), V(18) }, + { V( 0), V( 67), V( 145), V(49), V(33) }, + { V( 0), V( 62), V( 126), V(53), V(21) } } }; // Max bonus for king safety. Corresponds to start position with all the pawns // in front of the king and no enemy pawn on the horizon. - const Value MaxSafetyBonus = V(261); + const Value MaxSafetyBonus = V(258); #undef S #undef V @@ -143,12 +144,11 @@ namespace { lever = theirPawns & pawnAttacksBB[s]; // Test for backward pawn. - // If the pawn is passed, isolated, or connected it cannot be + // If the pawn is passed, isolated, connected or a lever it cannot be // backward. If there are friendly pawns behind on adjacent files - // or if it can capture an enemy pawn it cannot be backward either. - if ( (passed | isolated | connected) - || (ourPawns & pawn_attack_span(Them, s)) - || (pos.attacks_from(s, Us) & theirPawns)) + // it cannot be backward either. + if ( (passed | isolated | lever | connected) + || (ourPawns & pawn_attack_span(Them, s))) backward = false; else { @@ -202,9 +202,9 @@ namespace { namespace Pawns { -/// init() initializes some tables used by evaluation. Instead of hard-coded -/// tables, when makes sense, we prefer to calculate them with a formula to -/// reduce independent parameters and to allow easier tuning and better insight. +/// Pawns::init() initializes some tables needed by evaluation. Instead of using +/// hard-coded tables, when makes sense, we prefer to calculate them with a formula +/// to reduce independent parameters and to allow easier tuning and better insight. void init() { @@ -220,14 +220,15 @@ void init() } -/// probe() takes a position as input, computes a Entry object, and returns a -/// pointer to it. The result is also stored in a hash table, so we don't have -/// to recompute everything when the same pawn structure occurs again. +/// Pawns::probe() looks up the current position's pawns configuration in +/// the pawns hash table. It returns a pointer to the Entry if the position +/// is found. Otherwise a new Entry is computed and stored there, so we don't +/// have to recompute all when the same pawns configuration occurs again. -Entry* probe(const Position& pos, Table& entries) { +Entry* probe(const Position& pos) { Key key = pos.pawn_key(); - Entry* e = entries[key]; + Entry* e = pos.this_thread()->pawnsTable[key]; if (e->key == key) return e; @@ -286,7 +287,7 @@ Score Entry::do_king_safety(const Position& pos, Square ksq) { Bitboard pawns = pos.pieces(Us, PAWN); if (pawns) - while (!(DistanceRingsBB[ksq][minKingPawnDistance[Us]++] & pawns)) {} + while (!(DistanceRingBB[ksq][minKingPawnDistance[Us]++] & pawns)) {} if (relative_rank(Us, ksq) > RANK_4) return make_score(0, -16 * minKingPawnDistance[Us]);