From 00fc61020ca7982ee506d9fde1cec9b9c5f43fa9 Mon Sep 17 00:00:00 2001
From: Bruno Raoult <braoult@gmail.com>
Date: Thu, 6 Jun 2024 07:38:01 +0200
Subject: [PATCH] "#define key_t" -> hkey_t type

---
 src/hash.c     |  4 ++--
 src/hash.h     | 14 +++++++-------
 src/move-do.c  |  6 +++---
 src/position.h | 10 +++++++++-
 4 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/src/hash.c b/src/hash.c
index f9b4112..5f3756e 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -66,9 +66,9 @@ void zobrist_init(void)
  *
  * @return: @pos Zobrist key
  */
-key_t zobrist_calc(pos_t *pos)
+hkey_t zobrist_calc(pos_t *pos)
 {
-    key_t key = 0;
+    hkey_t key = 0;
 
     if (pos->turn == BLACK)
         key ^= zobrist_turn;
diff --git a/src/hash.h b/src/hash.h
index 438ffee..a270c47 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -24,7 +24,7 @@
 #define HASH_SIZE_MIN        4
 #define HASH_SIZE_MAX    32768                    /* 32Gb */
 
-#define key_t u64                                 /* cannot use typedef for key_t */
+typedef u64 hkey_t;                               /* cannot use typedef for key_t */
 
 /**
  * hentry_t: hashtable bucket.
@@ -33,7 +33,7 @@
  * 16 bytes in future, it should be updated to be exactly 32 bytes.
  */
 typedef struct {
-    key_t key;                                    /* zobrist */
+    hkey_t key;                                    /* zobrist */
     union {
         u64 data;
         struct {
@@ -81,15 +81,15 @@ typedef struct {
  */
 #define EP_ZOBRIST_IDX(ep) ( ( (ep) >> 3 ) | sq_file(ep) )
 
-extern key_t zobrist_pieces[16][64];
-extern key_t zobrist_castling[4 * 4 + 1];
-extern key_t zobrist_turn;                        /* for black, XOR each ply */
-extern key_t zobrist_ep[9];                       /* 0-7: ep file, 8: SQUARE_NONE */
+extern hkey_t zobrist_pieces[16][64];
+extern hkey_t zobrist_castling[4 * 4 + 1];
+extern hkey_t zobrist_turn;                        /* for black, XOR each ply */
+extern hkey_t zobrist_ep[9];                       /* 0-7: ep file, 8: SQUARE_NONE */
 
 extern hasht_t hash_tt;                           /* main transposition table */
 
 void zobrist_init(void);
-key_t zobrist_calc(pos_t *pos);
+hkey_t zobrist_calc(pos_t *pos);
 
 #ifdef ZOBRIST_VERIFY
 bool zobrist_verify(pos_t *pos);
diff --git a/src/move-do.c b/src/move-do.c
index 8fbf9e4..cc4c333 100644
--- a/src/move-do.c
+++ b/src/move-do.c
@@ -61,7 +61,7 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
     piece_type_t ptype = PIECE(piece);
     piece_t new_piece = piece;
     int up = sq_up(us);
-    key_t key = pos->key;
+    hkey_t key = pos->key;
 
     /* update key: switch turn, reset castling and ep */
     key ^= zobrist_turn;
@@ -146,7 +146,7 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
             pos->castle = clr_oo(pos->castle, them);
     }
 
-    /* update castle key */
+    /* update castling rights key */
     key ^= zobrist_castling[pos->castle];
 
     pos->key = key;
@@ -168,7 +168,7 @@ pos_t *move_do2(pos_t *pos, const move_t move, state_t *state)
     piece_type_t ptype = PIECE(piece);
     piece_t new_piece = piece;
     int up = sq_up(us);
-    key_t key = pos->key;
+    hkey_t key = pos->key;
 
     *state = pos->state;                          /* save irreversible changes */
 
diff --git a/src/position.h b/src/position.h
index 8a8b8a9..a3eeb67 100644
--- a/src/position.h
+++ b/src/position.h
@@ -28,6 +28,13 @@
 #include "move.h"
 #include "board.h"
 
+#define REPEAT_SIZE 1024
+
+typedef struct {
+    hkey_t key[REPEAT_SIZE];
+    int moves;
+} repeat_t;
+
 typedef struct __pos_s {
     u64 node_count;                               /* evaluated nodes */
     int turn;                                     /* WHITE or BLACK */
@@ -43,7 +50,7 @@ typedef struct __pos_s {
      * This allows a memcpy on this data (to save/restore position state).
      */
     struct_group_tagged(state_s, state,
-                        key_t key;
+                        hkey_t key;
                         square_t en_passant;
                         castle_rights_t castle;
                         int clock_50;
@@ -57,6 +64,7 @@ typedef struct __pos_s {
     piece_t board[BOARDSIZE];
     bitboard_t bb[2][PIECE_TYPE_MAX];             /* bb[0][PAWN], bb[1][ALL_PIECES] */
     square_t king[2];                             /* dup with bb, faster retrieval */
+    repeat_t repeat;                              /* for repetition detection */
 } pos_t;
 
 typedef struct state_s state_t;