Add pawn structure history (#705)

Elo | 4.30 +- 3.35 (95%) SPRT | 8.0+0.08s Threads=1 Hash=32MB LLR | 2.97 (-2.94, 2.94) [0.00, 3.00] Games | N: 21672 W: 5826 L: 5558 D: 10288 Penta | [339, 2546, 4823, 2764, 364] http://chess.grantnet.us/test/34696/ Elo | 1.89 +- 1.92 (95%) SPRT | 40.0+0.40s Threads=1 Hash=128MB LLR | 2.95 (-2.94, 2.94) [0.00, 3.00] Games | N: 59734 W: 14432 L: 14107 D: 31195 Penta | [378, 7041, 14763, 7248, 437] http://chess.grantnet.us/test/34702/ Bench: 21514164
TerjeKir · Dec 10, 2023 · 20c95ce · 20c95ce
1 parent 607b503
commit 20c95ce
Show file tree

Hide file tree

Showing 3 changed files with 12 additions and 0 deletions.
diff --git a/src/history.h b/src/history.h
@@ -27,10 +27,12 @@
 
 
 #define QuietEntry(move)        (&thread->history[thread->pos.stm][fromSq(move)][toSq(move)])
+#define PawnEntry(move)         (&thread->pawnHistory[PawnStructure(&thread->pos)][piece(move)][toSq(move)])
 #define NoisyEntry(move)        (&thread->captureHistory[piece(move)][toSq(move)][PieceTypeOf(capturing(move))])
 #define ContEntry(offset, move) (&(*(ss-offset)->continuation)[piece(move)][toSq(move)])
 
 #define QuietHistoryUpdate(move, bonus)        (HistoryBonus(QuietEntry(move),        bonus,  7180))
+#define PawnHistoryUpdate(move, bonus)         (HistoryBonus(PawnEntry(move),         bonus,  8192))
 #define NoisyHistoryUpdate(move, bonus)        (HistoryBonus(NoisyEntry(move),        bonus, 16384))
 #define ContHistoryUpdate(offset, move, bonus) (HistoryBonus(ContEntry(offset, move), bonus, 28650))
 
@@ -68,12 +70,14 @@ INLINE void UpdateQuietHistory(Thread *thread, Stack *ss, Move bestMove, Depth d
     // Bonus to the move that caused the beta cutoff
     if (depth > 2) {
         QuietHistoryUpdate(bestMove, bonus);
+        PawnHistoryUpdate(bestMove, bonus);
         UpdateContHistories(ss, bestMove, bonus);
     }
 
     // Penalize quiet moves that failed to produce a cut
     for (Move *move = quiets; move < quiets + qCount; ++move) {
         QuietHistoryUpdate(*move, malus);
+        PawnHistoryUpdate(*move, malus);
         UpdateContHistories(ss, *move, malus);
     }
 }
@@ -99,6 +103,7 @@ INLINE void UpdateHistory(Thread *thread, Stack *ss, Move bestMove, Depth depth,
 
 INLINE int GetQuietHistory(const Thread *thread, Stack *ss, Move move) {
     return  *QuietEntry(move)
+          + *PawnEntry(move)
           + *ContEntry(1, move)
           + *ContEntry(2, move)
           + *ContEntry(4, move);

diff --git a/src/threads.c b/src/threads.c
@@ -126,6 +126,7 @@ void ResetThreads() {
     for (int i = 0; i < threads->count; ++i)
         memset(threads[i].pawnCache,      0, sizeof(PawnCache)),
         memset(threads[i].history,        0, sizeof(threads[i].history)),
+        memset(threads[i].pawnHistory,    0, sizeof(threads[i].pawnHistory)),
         memset(threads[i].captureHistory, 0, sizeof(threads[i].captureHistory)),
         memset(threads[i].continuation,   0, sizeof(threads[i].continuation));
 }

diff --git a/src/threads.h b/src/threads.h
@@ -27,9 +27,14 @@
 
 #define SS_OFFSET 10
 #define MULTI_PV_MAX 64
+#define PAWN_HISTORY_SIZE 512
 
+INLINE int PawnStructure(const Position *pos) {
+    return pos->pawnKey & (PAWN_HISTORY_SIZE - 1);
+}
 
 typedef int16_t ButterflyHistory[COLOR_NB][64][64];
+typedef int16_t PawnHistory[PAWN_HISTORY_SIZE][PIECE_NB][64];
 typedef int16_t CaptureToHistory[PIECE_NB][64][TYPE_NB];
 typedef int16_t PieceToHistory[PIECE_NB][64];
 typedef PieceToHistory ContinuationHistory[PIECE_NB][64];
@@ -68,6 +73,7 @@ typedef struct Thread {
     Position pos;
     PawnCache pawnCache;
     ButterflyHistory history;
+    PawnHistory pawnHistory;
     CaptureToHistory captureHistory;
     ContinuationHistory continuation[2][2];