Module Name: src
Committed By: rillig
Date: Sun May 29 01:17:55 UTC 2022
Modified Files:
src/games/gomoku: pickmove.c
Log Message:
gomoku: migrate pickmove to use spot_index instead of pointers
Using spot_index instead of pointers leads to simpler code since there
is no need to deal with conversion from ptrdiff_t to spot_index.
No functional change.
To generate a diff of this commit:
cvs rdiff -u -r1.50 -r1.51 src/games/gomoku/pickmove.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/games/gomoku/pickmove.c
diff -u src/games/gomoku/pickmove.c:1.50 src/games/gomoku/pickmove.c:1.51
--- src/games/gomoku/pickmove.c:1.50 Sun May 29 00:38:26 2022
+++ src/games/gomoku/pickmove.c Sun May 29 01:17:55 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: pickmove.c,v 1.50 2022/05/29 00:38:26 rillig Exp $ */
+/* $NetBSD: pickmove.c,v 1.51 2022/05/29 01:17:55 rillig Exp $ */
/*
* Copyright (c) 1994
@@ -34,7 +34,7 @@
#include <sys/cdefs.h>
/* @(#)pickmove.c 8.2 (Berkeley) 5/3/95 */
-__RCSID("$NetBSD: pickmove.c,v 1.50 2022/05/29 00:38:26 rillig Exp $");
+__RCSID("$NetBSD: pickmove.c,v 1.51 2022/05/29 01:17:55 rillig Exp $");
#include <stdlib.h>
#include <string.h>
@@ -68,7 +68,7 @@ static int forcemap[MAPSZ]; /* map for
static int tmpmap[MAPSZ]; /* map for blocking <1,x> combos */
static int nforce; /* count of opponent <1,x> combos */
-static bool better(const struct spotstr *, const struct spotstr *, int);
+static bool better(spot_index, spot_index, int);
static void scanframes(int);
static void makecombo2(struct combostr *, struct spotstr *, int, int);
static void addframes(unsigned int);
@@ -111,17 +111,17 @@ pickmove(int us)
scanframes(WHITE);
/* find the spot with the highest value */
- unsigned pos = PT(BSZ, BSZ);
- struct spotstr *sp1 = &board[pos];
- struct spotstr *sp2 = sp1;
- for ( ; pos-- > PT(1, 1); ) {
- struct spotstr *sp = &board[pos];
+ spot_index s = PT(BSZ, BSZ);
+ spot_index s1 = s;
+ spot_index s2 = s;
+ for ( ; s-- > PT(1, 1); ) {
+ struct spotstr *sp = &board[s];
if (sp->s_occ != EMPTY)
continue;
if (debug != 0 && (sp->s_combo[BLACK].cv_force == 1 ||
sp->s_combo[WHITE].cv_force == 1)) {
debuglog("- %s %x/%d %d %x/%d %d %d",
- stoc((int)(sp - board)),
+ stoc(s),
sp->s_combo[BLACK].s, sp->s_level[BLACK],
sp->s_nforce[BLACK],
sp->s_combo[WHITE].s, sp->s_level[WHITE],
@@ -129,22 +129,23 @@ pickmove(int us)
sp->s_wval);
}
/* pick the best black move */
- if (better(sp, sp1, BLACK))
- sp1 = sp;
+ if (better(s, s1, BLACK))
+ s1 = s;
/* pick the best white move */
- if (better(sp, sp2, WHITE))
- sp2 = sp;
+ if (better(s, s2, WHITE))
+ s2 = s;
}
if (debug != 0) {
+ const struct spotstr *sp1 = &board[s1], *sp2 = &board[s2];
debuglog("B %s %x/%d %d %x/%d %d %d",
- stoc((int)(sp1 - board)),
+ stoc(s1),
sp1->s_combo[BLACK].s, sp1->s_level[BLACK],
sp1->s_nforce[BLACK],
sp1->s_combo[WHITE].s, sp1->s_level[WHITE],
sp1->s_nforce[WHITE], sp1->s_wval);
debuglog("W %s %x/%d %d %x/%d %d %d",
- stoc((int)(sp2 - board)),
+ stoc(s2),
sp2->s_combo[WHITE].s, sp2->s_level[WHITE],
sp2->s_nforce[WHITE],
sp2->s_combo[BLACK].s, sp2->s_level[BLACK],
@@ -153,24 +154,24 @@ pickmove(int us)
* Check for more than one force that can't
* all be blocked with one move.
*/
- struct spotstr *sp = (us == BLACK) ? sp2 : sp1;
- int m = (int)(sp - board);
- if (sp->s_combo[us != BLACK ? BLACK : WHITE].cv_force == 1 &&
+ spot_index m = us == BLACK ? s2 : s1;
+ int them = us != BLACK ? BLACK : WHITE;
+ if (board[m].s_combo[them].cv_force == 1 &&
!BIT_TEST(forcemap, m))
debuglog("*** Can't be blocked");
}
union comboval *Ocp, *Tcp;
if (us == BLACK) {
- Ocp = &sp1->s_combo[BLACK];
- Tcp = &sp2->s_combo[WHITE];
+ Ocp = &board[s1].s_combo[BLACK];
+ Tcp = &board[s2].s_combo[WHITE];
} else {
- Tcp = &sp1->s_combo[BLACK];
- Ocp = &sp2->s_combo[WHITE];
+ Tcp = &board[s1].s_combo[BLACK];
+ Ocp = &board[s2].s_combo[WHITE];
- struct spotstr *sp = sp1;
- sp1 = sp2;
- sp2 = sp;
+ spot_index tmp = s1;
+ s1 = s2;
+ s2 = tmp;
}
/*
* Block their combo only if we have to (i.e., if they are one move
@@ -179,16 +180,17 @@ pickmove(int us)
*/
if (Tcp->cv_force <= 1 && (Ocp->cv_force > 1 ||
Tcp->cv_force + Tcp->cv_win < Ocp->cv_force + Ocp->cv_win))
- return (int)(sp2 - board);
- return (int)(sp1 - board);
+ return s2;
+ return s1;
}
/*
* Return true if spot 'sp' is better than spot 'sp1' for color 'us'.
*/
static bool
-better(const struct spotstr *sp, const struct spotstr *sp1, int us)
+better(spot_index s, spot_index s1, int us)
{
+ const struct spotstr *sp = &board[s], *sp1 = &board[s1];
if (/* .... */ sp->s_combo[us].s != sp1->s_combo[us].s)
return sp->s_combo[us].s < sp1->s_combo[us].s;
@@ -198,8 +200,6 @@ better(const struct spotstr *sp, const s
return sp->s_nforce[us] > sp1->s_nforce[us];
int them = us != BLACK ? BLACK : WHITE;
- spot_index s = (spot_index)(sp - board);
- spot_index s1 = (spot_index)(sp1 - board);
if (BIT_TEST(forcemap, s) != BIT_TEST(forcemap, s1))
return BIT_TEST(forcemap, s);
