X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=main.c;h=69f56d1a30e8bba421e9e7a7231019a45f08b09d;hb=41013cb05383473c8ffdcf9afc89dde04760a847;hp=d2900152f1336eaace2a8b656024f9f48dde100e;hpb=c40dd9fe9a488a35d31dcf0083c4271660678f08;p=matchsticks-search.git

diff --git a/main.c b/main.c
index d290015..69f56d1 100644
--- a/main.c
+++ b/main.c
@@ -91,6 +91,8 @@
 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;
@@ -99,7 +101,7 @@ static double best;
 static glp_prob *best_prob;
 static AdjWord *best_adjmatrix;
 
-static int n_over_best;
+static int n_over_best, m_over_best;
 static int *weight;
 
 static unsigned printcounter;
@@ -118,6 +120,7 @@ static void progress_eol(void) {
 static void set_best(double new_best) {
   best = new_best;
   n_over_best = floor(n / best);
+  m_over_best = floor(m / best);
 }
 
 /*----- multicore support -----*/
@@ -308,10 +311,10 @@ static void multicore(void) {
 
   for (w=0; w<ncpus; w++) {
     mc_rwvsetup_full();
-    LPRINTF("reading report from %2d\n",w);
+    LPRINTF("reading report from %2d",w);
     ssize_t sr = preadv(fileno(mc_workers[w].results), mc_iov, mc_niovs, 0);
     if (!sr) continue;
-    LPRINTF("got report from %2d\n",w);
+    LPRINTF("got report from %2d",w);
     maxhamweight = 0;
     optimise(1);
   }
@@ -354,16 +357,20 @@ static void prep(void) {
   setlinebuf(stderr);
   weight = calloc(sizeof(*weight), m);  assert(weight);
   n_over_best = INT_MAX;
+  m_over_best = INT_MAX;
 }
 
+#if 0
 static AdjWord one_adj_bit(int bitnum) {
   return (AdjWord)1 << bitnum;
 }
+#endif
 
 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;
 }
 
@@ -372,8 +379,7 @@ static int count_set_adj_bits(AdjWord w) {
 static int totalfrags;
 
 static bool maxhamweight_ok(void) {
-  double maxminsize = (double)m / maxhamweight;
-  return maxminsize > best;
+  return maxhamweight <= m_over_best;
 }
 
 static bool preconsider_ok(int nwords, bool doprint) {
@@ -384,14 +390,13 @@ static bool preconsider_ok(int nwords, bool doprint) {
   bool had_max = 0;
   for (i=0, totalfrags=0; i<nwords; i++) {
     int frags = count_set_adj_bits(adjmatrix[i]);
-    had_max += (frags >= maxhamweight);
-    totalfrags += frags;
     PRINTF("%"PRADJ" ", adjmatrix[i]);
-    double maxminsize = (double)m / frags;
-    if (maxminsize <= best) {
+    if (frags > m_over_best) {
       PRINTF(" too fine");
       goto out;
     }
+    had_max += (frags >= maxhamweight);
+    totalfrags += frags;
   }
   if (!had_max) {
     /* Skip this candidate as its max hamming weight is lower than
@@ -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;
+  AdjWord jbit;
 
   /*
    * 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++) {
-    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 */
@@ -598,6 +604,9 @@ static void optimise(bool doprint) {
 }
 
 static void iterate_recurse(int i, AdjWord min) {
+  int j;
+  AdjWord jbit;
+
   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;
 
-    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)
@@ -625,8 +634,8 @@ static void iterate_recurse(int i, AdjWord min) {
     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: