still not working

Makefile

@@ -1,6 +1,6 @@
 HEADERS=coxeter.h thickenings.h queue.h bitvec.h
 #OPTIONS=-O3 -m64 -march=native -flto -funroll-loops -std=gnu99
-OPTIONS=-O0 -g -std=gnu99
+OPTIONS=-m64 -march=native -O0 -g -std=gnu99
 #OPTIONS=-O3 -m64 -march=native -funroll-loops -fno-inline -std=gnu99 -pg
 
 all: generate process

bitvec.h

@@ -27,6 +27,10 @@
 /* For _mm_popcnt_u64 */
 #include <x86intrin.h>
 
+// FIRSTBITS(n) only yields useful result when 0 <= n < 64
+#define FIRSTBITS(n) ((1l << (n)) - 1l)
+#define ALLBITS ((uint64_t)-1)
+
 typedef struct {
   uint64_t v[BV_QWORD_RANK];
 } bitvec_t;
@@ -129,6 +133,8 @@ static inline void bv_print(FILE *f, const bitvec_t *x, int len)
 {
   for(int i = 0; i < len; i++) {
     fputc(bv_get_bit(x, i) ? '1' : '0', f);
+    if(i % 64 == 63)
+      fputc('-',f);
   }
 }
 
@@ -161,22 +167,39 @@ static inline int bv_full(const bitvec_t *x, int len)
 {
   int i;
   for(i = 0; i < len/64; i++)
-    if(x->v[i] != (uint64_t)-1)
+    if(x->v[i] != ALLBITS)
       return 0;
 
-  return (x->v[i] & ((1<<(len%64))-1)) == ((1<<(len%64))-1);
+  return (x->v[i] & FIRSTBITS(len%64)) == FIRSTBITS(len%64);
 }
 
-// most sigificant set bit in bits 0...start-1
-static inline int bv_last_zero_before(const bitvec_t *x, int start)
+// set bits in range start...end (including start and excluding end)
+static inline void bv_set_range(bitvec_t *x, int start, int end)
 {
-  // naive implementation
-  int i;
-  for(i = start - 1; i >= 0; i--)
-    if(!bv_get_bit(x, i))
-      break;
+  if(start/64 == end/64)
+    x->v[start/64] |= ~FIRSTBITS(start % 64) & FIRSTBITS(end % 64);
+  else {
+    x->v[start/64] |= ~FIRSTBITS(start % 64);
+    for(int i = start/64 + 1; i < end/64; i++)
+      x->v[i] = ALLBITS;
+    x->v[end/64] |= FIRSTBITS(end % 64);
+  }
+}
 
-  return i;
+// find least significant 0 bit starting from position start (included)
+static inline int bv_next_zero(const bitvec_t *x, int start)
+{
+  int position, i;
+
+  position = ffsll(~(x->v[start/64] | FIRSTBITS(start % 64)));
+
+  if(position)   // found zero in same chunk?
+    return (start/64)%64 + position - 1;
+
+  for(i = start/64 + 1, position = 0; i < BV_QWORD_RANK && position == 0; i++)
+    position = ffsll(~x->v[i]);
+
+  return position ? (i - 1)*64 + position - 1 : BV_QWORD_RANK;
 }
 
 /* static inline int bv_lowest_bit_set(bitvec_t x) */

thickenings.c

@@ -665,20 +665,93 @@ static inline void output_thickening(const enumeration_info_t *info, signed char
    how can we handle negatives right to head?!
 */
 
+/*
+
+   ok this is screwed up, let's start over:
+
+   pos and neg are bitvectors of size info.size/2
+   they stand for the first (shortest) info.size/2 elements of the weyl group
+   the least siginficant bit is the identity
+
+   at the beginning they are cleared, meaning everything is undecided
+ */
+
+
+// enumerate all balanced ideals which contain everything in pos and everything strictly between known_until and next_neg, and which do not contain everything in neg, as well as next_neg
+// assuming all bits up to known_until are set either in pos or in neg, but not in both
+// returns number of found balanced ideals
+// next_neg can be info.size/2; in that case, everything between known_until and info.size/2 is required to be in the ideal, but it does not mean that next_neg is really not contained in the ideal
+// next_neg must be strictly greater than known_until, and less or equal to info.size/2
+static long enumerate_tree(const enumeration_info_t *info, const bitvec_t *pos, const bitvec_t *neg, int first_unknown, int next_neg)
+{
+  bitvec_t newpos, newneg, known;
+  int next_next_neg;
+  long count = 0;
+
+  // the omission of next_neg means inclusion of info->size - 1 - next_neg
+  // add its principal ideal to pos and the opposite to neg
+  if(next_neg != info->size/2) {
+    bv_union(&info->principal_pos[info->size - 1 - next_neg], pos, &newpos);
+    bv_union(&info->principal_neg[info->size - 1 - next_neg], neg, &newneg);
+  }
+
+  // add the range from first_unknown to next_neg to newpos
+  bv_set_range(&newpos, first_unknown, next_neg); // including the start, excluding end
+
+  bitvec_t test1, test2;
+  bv_print(stderr, &newpos, info->size/2);
+  fprintf(stderr, " ");
+  bv_print(stderr, &newneg, info->size/2);
+  fprintf(stderr, " ");
+  bv_union(&newpos, &newneg, &test1);
+  bv_print(stderr, &test1, info->size/2);
+  fprintf(stderr, " %d\n", bv_disjoint(&newpos, &newneg));
+
+
+  // check if this leads to any conflicts (equivalently, violates slimness)
+  if(!bv_disjoint(&newpos, &newneg))
+    return 0;
+
+  // what do we know so far?
+  bv_union(&newpos, &newneg, &known);
+
+  // do we know everything already? we have a balanced ideal then
+  if(bv_full(&known, info->size/2)) {
+    fprintf(stderr, "Found balanced ideal: ");
+    bv_print(stderr, &newpos, info->size/2);
+    fprintf(stderr, " ");
+    bv_print(stderr, &newneg, info->size/2);
+    fprintf(stderr, "\n");
+
+    return 1;
+  }
+
+  next_next_neg = next_neg;
+  while(next_next_neg < info->size/2) {
+    next_next_neg = bv_next_zero(&known, next_next_neg + 1); // this could return info->size/2, but that's fine for enumerate_tree
+    count += enumerate_tree(info, &newpos, &newneg, next_neg + 1, next_next_neg);
+  }
+}
+
+/*
 static long enumerate_tree(const enumeration_info_t *info, const bitvec_t *pos, const bitvec_t *neg, int head, int oldhead)
 {
   bitvec_t newpos, newneg, known;
   int newhead;
   long count = 0;
 
-  bv_union(&info->principal_pos[head], pos, &newpos);
-  bv_union(&info->principal_neg[head], neg, &newneg);
-
-  for(int i = oldhead - 1; i > head; i--) {
-    bv_union(&info->principal_pos[info->size-1-i], &newpos, &newpos);
-    bv_union(&info->principal_neg[info->size-1-i], &newneg, &newneg);
+  if(head < info->size/2) {
+    fprintf(stderr, "head is %d!\n", head);
   }
 
+  if(head != -1) {
+    bv_union(&info->principal_pos[head], pos, &newpos);
+    bv_union(&info->principal_neg[head], neg, &newneg);
+  }
+
+  for(int i = oldhead - 1; i > head && i >= info->size/2; i--)
+    bv_set_bit(&newpos, info->size - 1 - i);
+
   if(!bv_disjoint(&newpos, &newneg))
     return 0;
 
@@ -696,16 +769,16 @@ static long enumerate_tree(const enumeration_info_t *info, const bitvec_t *pos,
     return 1;
   }
 
-  newhead = bv_last_zero_before(&known, head);
-  while(newhead >= 0) {
+  newhead = head;
+  while(newhead >= info->size/2) {
+    newhead = bv_last_zero_before(&known, newhead);  // this will return -1 at some point, which stands for the possibility that all remaining choices are "no"
     count += enumerate_tree(info, &newpos, &newneg, newhead, head);
-    newhead = bv_last_zero_before(&known, newhead);
   }
 
   return count;
 }
 
-/*
+
 
 static long enumerate_tree(const enumeration_info_t *info, signed char *level, int current_level, int head)
 {
@@ -822,19 +895,22 @@ long enumerate_balanced_thickenings(semisimple_type_t type, node_t *graph, int s
     fprintf(stderr, "\n");
   }
 
+  // test these functions a little
+  bitvec_t test;
+  bv_clear(&test);
+  bv_set_range(&test, 0, 4);
+  bv_print(stderr, &test, 200);
+  fprintf(stderr, " %d\n", bv_full(&test, 6));
+
+  // don't do enumeration
+  //  return count;
+
   // enumerate balanced ideals
   bitvec_t pos, neg;
   bv_clear(&pos);
   bv_clear(&neg);
-  for(int i = info.size - 1; i >= 0; i--)
-    count += enumerate_tree(&info, &pos, &neg, i, info.size);
-
-  /*  old algorithm:
-      level = (signed char*)malloc(info.size*sizeof(int));
-      memset(level, 0, info.size*sizeof(int));
-
-      for(int i = info.size - 1; i >= 0; i--)
-      count += enumerate_tree(&info, level, 1, i); */
+  for(int i = 0; i <= info.size/2; i++)
+    count += enumerate_tree(&info, &pos, &neg, 0, i);
 
   free(principal_pos);
   free(principal_neg);