Give pieces of same type same Zobrist key

Give different piece keys to white and black pieces of same type. Switch
to a system that assigns the key 'on demand', when the entry in the
list of piece descriptions is first used. Let Lookup return pointer
rather than number in list, so that future versions can search in multiple
lists (for other variants).

diff --git a/hachu.c b/hachu.c
index 05529dc..5b93431 100644 (file)
--- a/hachu.c
+++ b/hachu.c
@@ -78,6 +78,7 @@ typedef struct {
   char *name, *promoted;\r
   int value;\r
   signed char range[8];\r
+  int whiteKey, blackKey;\r
 } PieceDesc;\r
 \r
 typedef struct {\r
@@ -420,11 +421,12 @@ signed char PST[2*BSIZE];
 #define board (rawBoard + 6*BW + 3)\r
 #define dist  (distance + BSIZE)\r
 \r
-int LookUp(char *name, PieceDesc *list)\r
+PieceDesc *\r
+LookUp (char *name, PieceDesc *list)\r
 { // find piece of given name in list of descriptors\r
   int i=0;\r
   while(list->name && strcmp(name, list->name)) i++, list++;\r
-  return (list->name == NULL ? -1 : i);\r
+  return (list->name == NULL ? NULL : list);\r
 }\r
 \r
 void\r
@@ -507,21 +509,24 @@ Compactify (int stm)
 }\r
 \r
 int\r
-AddPiece (int stm, int n, PieceDesc *list)\r
+AddPiece (int stm, PieceDesc *list)\r
 {\r
-  int i, j;\r
+  int i, j, *key;\r
   for(i=stm+2; i<=last[stm]; i += 2) {\r
-    if(p[i].value < 10*list[n].value || p[i].value == 10*list[n].value && (p[i].promo < 0)) break;\r
+    if(p[i].value < 10*list->value || p[i].value == 10*list->value && (p[i].promo < 0)) break;\r
   }\r
   last[stm] += 2;\r
   for(j=last[stm]; j>i; j-= 2) p[j] = p[j-2];\r
-  p[i].value = 10*list[n].value;\r
-  for(j=0; j<8; j++) p[i].range[j] = list[n].range[j^4*(WHITE-stm)];\r
+  p[i].value = 10*list->value;\r
+  for(j=0; j<8; j++) p[i].range[j] = list->range[j^4*(WHITE-stm)];\r
   switch(Range(p[i].range)) {\r
     case 1:  p[i].pst = BH; break;\r
     case 2:  p[i].pst = BSIZE; break;\r
     default: p[i].pst = BSIZE + BH; break;\r
   }\r
+  key = (stm == WHITE ? &list->whiteKey : &list->blackKey);\r
+  if(!*key) *key = ~(myRandom()*myRandom());\r
+  p[i].pieceKey = *key;\r
   p[i].promoFlag = 0;\r
   for(j=stm+2; j<= last[stm]; j+=2) {\r
     if(p[j].promo >= i) p[j].promo += 2;\r
@@ -534,8 +539,9 @@ AddPiece (int stm, int n, PieceDesc *list)
 void\r
 SetUp(char *array, PieceDesc *list)\r
 {\r
-  int i, j, k, k2, n, m, nr, color;\r
+  int i, j, n, m, nr, color;\r
   char c, *q, name[3];\r
+  PieceDesc *p1, *p2;\r
   last[WHITE] = 1; last[BLACK] = 0;\r
   for(i=0; ; i++) {\r
 //printf("next rank: %s\n", array);\r
@@ -551,17 +557,17 @@ SetUp(char *array, PieceDesc *list)
        name[0] += 'A' - 'a';\r
        if(name[1]) name[1] += 'A' - 'a';\r
       } else color = WHITE;\r
-      k = LookUp(name, list);\r
-      n = AddPiece(color, k, list);\r
+      p1 = LookUp(name, list);\r
+      n = AddPiece(color, p1);\r
       p[n].pos = j;\r
-      if(list[k].promoted[0]) {\r
-       k2 = LookUp(list[k].promoted, list);\r
-        m = AddPiece(color, k2, list);\r
+      if(p1->promoted[0]) {\r
+       p2 = LookUp(p1->promoted, list);\r
+        m = AddPiece(color, p2);\r
        if(m <= n) n += 2;\r
        p[n].promo = m;\r
-       p[n].promoFlag = IsUpwardCompatible(list[k2].range, list[k].range) * DONT_DEFER + CAN_PROMOTE;\r
-       if(Forward(list[k].range)) p[n].promoFlag |= LAST_RANK; // Pieces that only move forward can't defer on last rank\r
-       if(!strcmp(list[k].name, "N")) p[n].promoFlag |= CANT_DEFER; // Knights can't defer on last 2 ranks\r
+       p[n].promoFlag = IsUpwardCompatible(p2->range, p1->range) * DONT_DEFER + CAN_PROMOTE;\r
+       if(Forward(p1->range)) p[n].promoFlag |= LAST_RANK; // Pieces that only move forward can't defer on last rank\r
+       if(!strcmp(p1->name, "N")) p[n].promoFlag |= CANT_DEFER; // Knights can't defer on last 2 ranks\r
        p[n].promoFlag &= n&1 ? P_WHITE : P_BLACK;\r
        p[m].promo = -1;\r
        p[m].pos = ABSENT;\r
@@ -616,7 +622,6 @@ Init()
 \r
   // hash key tables\r
   for(i=0; i<BSIZE; i++) squareKey[i] = ~(myRandom()*myRandom());\r
-  for(i=0; i<NPIECES; i++) p[i].pieceKey = ~(myRandom()*myRandom());\r
 \r
   // board edge\r
   for(i=0; i<BSIZE + 11*BW + 6; i++) rawBoard[i] = EDGE;\r
@@ -1496,7 +1501,7 @@ Setup2 (char *fen)
 {\r
   SetUp(chuArray, chuPieces);\r
   sup0 = sup1 = sup2 = ABSENT;\r
-  rootEval = 0;\r
+  rootEval = hashKeyH = hashKeyL = 0;\r
   return WHITE;\r
 }\r
 \r