diff --git a/src/bitbase.cpp b/src/bitbase.cpp
index 3426a318..337a555f 100644
--- a/src/bitbase.cpp
+++ b/src/bitbase.cpp
@@ -47,13 +47,23 @@ namespace {
const int IndexMax = 2 * 24 * 64 * 64;
+ uint8_t KPKBitbase[IndexMax / 8];
+
Result classify_wtm(const KPKPosition& pos, const Result bb[]);
Result classify_btm(const KPKPosition& pos, const Result bb[]);
- int compute_index(Square wksq, Square bksq, Square psq, Color stm);
+ int compute_index(Square wksq, Square bksq, Square wpsq, Color stm);
}
-void generate_kpk_bitbase(uint8_t bitbase[]) {
+int probe_kpk_bitbase(Square wksq, Square wpsq, Square bksq, Color stm) {
+
+ int index = compute_index(wksq, bksq, wpsq, stm);
+
+ return KPKBitbase[index / 8] & (1 << (index & 7));
+}
+
+
+void init_kpk_bitbase() {
bool repeat;
int i, j, b;
@@ -86,7 +96,7 @@ void generate_kpk_bitbase(uint8_t bitbase[]) {
} while (repeat);
- // Compress result and map into supplied bitbase parameter
+ // Compress result and map into KPKBitbase[]
for (i = 0; i < 24576; i++)
{
b = 0;
@@ -94,16 +104,16 @@ void generate_kpk_bitbase(uint8_t bitbase[]) {
if (bb[8*i+j] == RESULT_WIN || bb[8*i+j] == RESULT_LOSS)
b |= (1 << j);
- bitbase[i] = (uint8_t)b;
+ KPKBitbase[i] = (uint8_t)b;
}
}
namespace {
- int compute_index(Square wksq, Square bksq, Square psq, Color stm) {
+ int compute_index(Square wksq, Square bksq, Square wpsq, Color stm) {
- int p = int(square_file(psq)) + (int(square_rank(psq)) - 1) * 4;
+ int p = int(square_file(wpsq)) + (int(square_rank(wpsq)) - 1) * 4;
int r = int(stm) + 2 * int(bksq) + 128 * int(wksq) + 8192 * p;
assert(r >= 0 && r < IndexMax);
diff --git a/src/endgame.cpp b/src/endgame.cpp
index 97274946..754e4031 100644
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -17,21 +17,13 @@
along with this program. If not, see .
*/
-
-////
-//// Includes
-////
-
#include
#include "bitcount.h"
#include "endgame.h"
#include "pawns.h"
-
-////
-//// Local definitions
-////
+extern int probe_kpk_bitbase(Square wksq, Square wpsq, Square bksq, Color stm);
namespace {
@@ -69,9 +61,6 @@ namespace {
// and knight in KR vs KN endgames.
const int KRKNKingKnightDistancePenalty[8] = { 0, 0, 4, 10, 20, 32, 48, 70 };
- // Bitbase for KP vs K
- uint8_t KPKBitbase[24576];
-
// Various inline functions for accessing the above arrays
inline Value mate_table(Square s) {
return Value(MateTable[s]);
@@ -89,23 +78,6 @@ namespace {
return Value(KRKNKingKnightDistancePenalty[d]);
}
- // Function for probing the KP vs K bitbase
- int probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm);
-
-}
-
-
-////
-//// Functions
-////
-
-/// init_bitbases() is called during program initialization, and simply loads
-/// bitbases from disk into memory. At the moment, there is only the bitbase
-/// for KP vs K, but we may decide to add other bitbases later.
-extern void generate_kpk_bitbase(uint8_t bitbase[]);
-
-void init_bitbases() {
- generate_kpk_bitbase(KPKBitbase);
}
@@ -204,7 +176,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
wpsq = flop_square(wpsq);
}
- if (!probe_kpk(wksq, wpsq, bksq, stm))
+ if (!probe_kpk_bitbase(wksq, wpsq, bksq, stm))
return VALUE_DRAW;
Value result = VALUE_KNOWN_WIN
@@ -890,21 +862,5 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
// Probe the KPK bitbase with the weakest side's pawn removed. If it's a
// draw, it's probably at least a draw even with the pawn.
- return probe_kpk(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_ZERO;
-}
-
-
-namespace {
-
- // Probe the KP vs K bitbase
-
- int probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm) {
-
- int wp = square_file(wpsq) + 4 * (square_rank(wpsq) - 1);
- int index = int(stm) + 2 * bksq + 128 * wksq + 8192 * wp;
-
- assert(index >= 0 && index < 24576 * 8);
-
- return KPKBitbase[index / 8] & (1 << (index & 7));
- }
+ return probe_kpk_bitbase(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_ZERO;
}
diff --git a/src/main.cpp b/src/main.cpp
index 86c7558c..e67adc69 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -38,7 +38,7 @@ using namespace std;
extern bool execute_uci_command(const string& cmd);
extern void benchmark(int argc, char* argv[]);
-extern void init_bitbases();
+extern void init_kpk_bitbase();
int main(int argc, char* argv[]) {
@@ -54,7 +54,7 @@ int main(int argc, char* argv[]) {
Position::init_zobrist();
Position::init_piece_square_tables();
init_eval(1);
- init_bitbases();
+ init_kpk_bitbase();
init_search();
init_threads();