[gnugo-devel] another speed up

[Paul Pogonyshev]

i hope this is the last one, at least in the nearest future ;)

this patch eliminates all excessive calls to countlib() in board.c
(function which is merely an interface for other modules). per Evan's
profile, the patch should decrease number of calls to countlib() by
more than 80%. speed up is small, about 0.5%, but it is there.

Paul


Index: board.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/board.c,v
retrieving revision 1.51
diff -u -r1.51 board.c
--- board.c     25 Sep 2002 19:47:49 -0000      1.51
+++ board.c     29 Sep 2002 19:27:02 -0000
@@ -2234,7 +2234,7 @@
   int all_libs1[MAXLIBS], *libs1;
   int liberties1, liberties2;
   int commonlibs = 0;
-  int k, n;
+  int k, n, tmp;
   
   ASSERT_ON_BOARD1(str1);
   ASSERT_ON_BOARD1(str2);
@@ -2244,15 +2244,17 @@
   if (!strings_initialized)
     init_board();
 
-  if (countlib(str1) > countlib(str2)) {
-    int tmp = str1;
+  n = string_number[str1];
+  liberties1 = string[n].liberties;
+  
+  if (liberties1 > string[string_number[str2]].liberties) {
+    n = string_number[str2];
+    liberties1 = string[n].liberties;
+    tmp = str1;
     str1 = str2;
     str2 = tmp;
   }
 
-  n = string_number[str1];
-  liberties1 = string[n].liberties;
-  
   if (liberties1 <= MAX_LIBERTIES) {
     /* Speed optimization: don't copy liberties with findlib */
     libs1 = string[n].libs;
@@ -2302,7 +2304,7 @@
   int all_libs1[MAXLIBS], *libs1;
   int liberties1, liberties2;
   int commonlibs = 0;
-  int k, n;
+  int k, n, tmp;
   
   ASSERT_ON_BOARD1(str1);
   ASSERT_ON_BOARD1(str2);
@@ -2313,14 +2315,16 @@
   if (!strings_initialized)
     init_board();
 
-  if (countlib(str1) > countlib(str2)) {
-    int tmp = str1;
+  n = string_number[str1];
+  liberties1 = string[n].liberties;
+  
+  if (liberties1 > string[string_number[str2]].liberties) {
+    n = string_number[str2];
+    liberties1 = string[n].liberties;
+    tmp = str1;
     str1 = str2;
     str2 = tmp;
   }
-
-  n = string_number[str1];
-  liberties1 = string[n].liberties;
   
   if (liberties1 <= MAX_LIBERTIES) {
     /* Speed optimization: don't copy liberties with findlib */
@@ -2369,9 +2373,9 @@
 int
 have_common_lib(int str1, int str2, int *lib)
 {
-  int libs1[MAXLIBS];
+  int all_libs1[MAXLIBS], *libs1;
   int liberties1;
-  int k;
+  int k, n, tmp;
   
   ASSERT_ON_BOARD1(str1);
   ASSERT_ON_BOARD1(str2);
@@ -2381,13 +2385,25 @@
   if (!strings_initialized)
     init_board();
 
-  if (countlib(str1) > countlib(str2)) {
-    int tmp = str1;
+  n = string_number[str1];
+  liberties1 = string[n].liberties;
+  
+  if (liberties1 > string[string_number[str2]].liberties) {
+    n = string_number[str2];
+    liberties1 = string[n].liberties;
+    tmp = str1;
     str1 = str2;
     str2 = tmp;
   }
+  
+  if (liberties1 <= MAX_LIBERTIES)
+    /* Speed optimization: don't copy liberties with findlib */
+    libs1 = string[n].libs;
+  else {
+    findlib(str1, MAXLIBS, all_libs1);
+    libs1 = all_libs1;
+  }
 
-  liberties1 = findlib(str1, MAXLIBS, libs1);
   for (k = 0; k < liberties1; k++) {
     if (neighbor_of_string(libs1[k], str2)) {
       if (lib)
@@ -2641,7 +2657,7 @@
    */
   if (!do_trymove(pos, color, 1))
     return 1;
-  liberties = countlib(pos);
+  liberties = string[string_number[pos]].liberties;
   silent_popgo();
   
   return liberties <= 1;