This is a non-functional simplification. Looks like std::bitset works good
for the KPKBitbase. Thanks for Jorg Oster for helping get the speed up
(the [] accessor is faster than test()).
Speed testing: 10k calls to probe:
master 9.8 sec
patch 9.8 sec.
STC
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 100154 W: 19025 L: 18992 D: 62137
Ptnml(0-2): 1397, 11376, 24572, 11254, 1473
http://tests.stockfishchess.org/tests/view/
5e21e601346e35ac603b7d2b
Closes https://github.com/official-stockfish/Stockfish/pull/2502
No functional change
#include <cassert>
#include <numeric>
#include <vector>
#include <cassert>
#include <numeric>
#include <vector>
#include "bitboard.h"
#include "types.h"
#include "bitboard.h"
#include "types.h"
// Positions with the pawn on files E to H will be mirrored before probing.
constexpr unsigned MAX_INDEX = 2*24*64*64; // stm * psq * wksq * bksq = 196608
// Positions with the pawn on files E to H will be mirrored before probing.
constexpr 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[MAX_INDEX / 32];
+ std::bitset<MAX_INDEX> KPKBitbase;
// A KPK bitbase index is an integer in [0, IndexMax] range
//
// A KPK bitbase index is an integer in [0, IndexMax] range
//
assert(file_of(wpsq) <= FILE_D);
assert(file_of(wpsq) <= FILE_D);
- unsigned idx = index(stm, bksq, wksq, wpsq);
- return KPKBitbase[idx / 32] & (1 << (idx & 0x1F));
+ return KPKBitbase[index(stm, bksq, wksq, wpsq)];
for (repeat = idx = 0; idx < MAX_INDEX; ++idx)
repeat |= (db[idx] == UNKNOWN && db[idx].classify(db) != UNKNOWN);
for (repeat = idx = 0; idx < MAX_INDEX; ++idx)
repeat |= (db[idx] == UNKNOWN && db[idx].classify(db) != UNKNOWN);
- // Map 32 results into one KPKBitbase[] entry
+ // Fill the bitbase with the decisive results
for (idx = 0; idx < MAX_INDEX; ++idx)
if (db[idx] == WIN)
for (idx = 0; idx < MAX_INDEX; ++idx)
if (db[idx] == WIN)
- KPKBitbase[idx / 32] |= 1 << (idx & 0x1F);