provide and use FOR_BITS

this seemed like it would make it faster but doesn't appear to have done so

diff --git a/main.c b/main.c
index d8ae901500852542834597f73332f1e5d70fbc1e..e8915f7c5661dcd93fb75479e22f80ebce7f629a 100644 (file)
--- a/main.c
+++ b/main.c
@@ -91,6 +91,8 @@
 typedef uint32_t AdjWord;
 #define PRADJ "08"PRIx32
 
 typedef uint32_t AdjWord;
 #define PRADJ "08"PRIx32
 

+#define FOR_BITS(j,m) for (j=0, j##bit=1; j < (m); j++, j##bit<<=1)
+

 static int n, m, maxhamweight;
 static AdjWord *adjmatrix;
 static AdjWord adjall;
 static int n, m, maxhamweight;
 static AdjWord *adjmatrix;
 static AdjWord adjall;


@@ -356,14 +358,17 @@ static void prep(void) {
   n_over_best = INT_MAX;
 }
 
   n_over_best = INT_MAX;
 }
 

+#if 0

 static AdjWord one_adj_bit(int bitnum) {
   return (AdjWord)1 << bitnum;
 }
 static AdjWord one_adj_bit(int bitnum) {
   return (AdjWord)1 << bitnum;
 }

+#endif

 
 static int count_set_adj_bits(AdjWord w) {
 
 static int count_set_adj_bits(AdjWord w) {

-  int j, total;
-  for (j=0, total=0; j<m; j++)
-    total += !!(w & one_adj_bit(j));
+  int j, total = 0;
+  AdjWord jbit;
+  FOR_BITS(j,m)
+    total += !!(w & jbit);

   return total;
 }
 
   return total;
 }
 


@@ -411,6 +416,7 @@ static void optimise(bool doprint) {
   /* Consider the best answer (if any) for a given adjacency matrix */
   glp_prob *prob = 0;
   int i, j;
   /* Consider the best answer (if any) for a given adjacency matrix */
   glp_prob *prob = 0;
   int i, j;

+  AdjWord jbit;

 
   /*
    * Up to a certain point, optimise() can be restarted.  We use this
 
   /*
    * Up to a certain point, optimise() can be restarted.  We use this


@@ -496,8 +502,8 @@ static void optimise(bool doprint) {
   glp_set_obj_coef(prob, X_minimum, 1);
 
   for (i=0; i<n; i++) {
   glp_set_obj_coef(prob, X_minimum, 1);
 
   for (i=0; i<n; i++) {

-    for (j=0; j<m; j++) {
-      if (!(adjmatrix[i] & one_adj_bit(j)))
+    for (j=0, jbit=1; j<m; j++, jbit<<=1) {
+      if (!(adjmatrix[i] & jbit))

        continue;
       /* x_total_i += x_minimum */
       /* x_total_j += x_minimum */
        continue;
       /* x_total_i += x_minimum */
       /* x_total_j += x_minimum */


@@ -598,6 +604,9 @@ static void optimise(bool doprint) {
 }
 
 static void iterate_recurse(int i, AdjWord min) {
 }
 
 static void iterate_recurse(int i, AdjWord min) {

+  int j;
+  AdjWord jbit;
+

   if (i >= n) {
     printcounter++;
     optimise(!(printcounter & 0xfff));
   if (i >= n) {
     printcounter++;
     optimise(!(printcounter & 0xfff));


@@ -615,8 +624,8 @@ static void iterate_recurse(int i, AdjWord min) {
     if (i == 0 && (adjmatrix[i] & (1+adjmatrix[i])))
       goto again;
 
     if (i == 0 && (adjmatrix[i] & (1+adjmatrix[i])))
       goto again;
 

-    for (int j = 0; j < m; j++)
-      if (adjmatrix[i] & one_adj_bit(j))
+    FOR_BITS(j,m)
+      if (adjmatrix[i] & jbit)

         weight[j]++;
     for (int j = 0; j < m; j++)
       if (weight[j] >= n_over_best)
         weight[j]++;
     for (int j = 0; j < m; j++)
       if (weight[j] >= n_over_best)


@@ -625,8 +634,8 @@ static void iterate_recurse(int i, AdjWord min) {
     iterate_recurse(i+1, adjmatrix[i]);
 
   takeout:
     iterate_recurse(i+1, adjmatrix[i]);
 
   takeout:

-    for (int j = 0; j < m; j++)
-      if (adjmatrix[i] & one_adj_bit(j))
+    FOR_BITS(j,m)
+      if (adjmatrix[i] & jbit)

         weight[j]--;
 
   again:
         weight[j]--;
 
   again: