* lib/bitset-int.h, lib/bitset.c, lib/bitset.h, lib/bitsetv.c,

* lib/bitsetv.h, lib/ebitset.c, lib/ebitset.h, lib/lbitset.c,
* lib/lbitset.h, lib/sbitset.c, lib/sbitset.h: New.
* src/closure.c (fderives): Be an array of bitsets.

1 files changed, 835 insertions, 0 deletions

diff --git a/lib/bitset.c b/lib/bitset.c
new file mode 100644
index 00000000..c68ed788
--- /dev/null
+++ b/lib/bitset.c
@@ -0,0 +1,835 @@
+/* General bitsets.
+   Copyright (C) 2002 Free Software Foundation, Inc.
+   Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include "bitset.h"
+#include "obstack.h"
+
+static void bitset_print PARAMS ((FILE *, bitset, int));
+
+#if BITSET_CHECK
+#define BITSET__CHECK2(DST, SRC) \
+if ((DST)->OPS != (SRC)->OPS) abort ();
+
+#define BITSET__CHECK3(DST, SRC1, SRC2) \
+if ((DST)->OPS != (SRC1)->OPS || (DST)->OPS != (SRC2)->OPS) abort ();
+
+#define BITSET__CHECK4(DST, SRC1, SRC2) \
+if ((DST)->OPS != (SRC1)->OPS || (DST)->OPS != (SRC2)->OPS \
+    || (DST)->OPS != (SRC3)->OPS) abort ();
+#else
+#define BITSET__CHECK2(DST, SRC)
+
+#define BITSET__CHECK3(DST, SRC1, SRC2)
+
+#define BITSET__CHECK4(DST, SRC1, SRC2, SRC3)
+#endif
+
+#if BITSET_STATS
+#define BITSET_STATS_FILE "bitset.dat"
+
+#define BITSET_LOG_COUNT_BINS 10
+#define BITSET_LOG_SIZE_BINS  16
+#define BITSET_DENSITY_BINS  20
+
+struct bitset_type_stats_struct
+{
+  unsigned int xmallocs;
+  unsigned int xfrees;
+  unsigned int oballocs;
+  unsigned int obfrees;
+  unsigned int lists;
+  unsigned int list_counts[BITSET_LOG_COUNT_BINS];
+  unsigned int list_sizes[BITSET_LOG_SIZE_BINS];
+  unsigned int list_density[BITSET_DENSITY_BINS];
+};
+
+struct bitset_stats_struct
+{
+    unsigned int runs;
+    struct bitset_type_stats_struct types[BITSET_TYPE_NUM];
+};
+
+struct bitset_stats_struct bitset_stats_data;
+struct bitset_stats_struct *bitset_stats;
+
+static void bitset_percent_histogram_print PARAMS ((FILE *, const char *,
+						    const char *,
+						    unsigned int,
+						    unsigned int *));
+static void bitset_log_histogram_print PARAMS ((FILE *, const char *,
+						const char *,
+						unsigned int, unsigned int *));
+static void bitset_stats_print_1 PARAMS ((FILE *, const char *,
+					  struct bitset_type_stats_struct *));
+static void bitset_stats_print PARAMS ((FILE *, int));
+static void bitset_stats_read PARAMS ((void));
+static void bitset_stats_write PARAMS ((void));
+
+#define BITSET_STATS_XMALLOCS_INC(TYPE) 		\
+  if (bitset_stats)					\
+    bitset_stats->types[(TYPE)].xmallocs++
+
+#define BITSET_STATS_XFREES_INC(BSET) 			\
+  if (bitset_stats)					\
+    bitset_stats->types[(BSET)->ops->type].xfrees++
+
+#define BITSET_STATS_OBALLOCS_INC(TYPE) 		\
+  if (bitset_stats)					\
+    bitset_stats->types[(TYPE)].oballocs++
+
+#define BITSET_STATS_OBFREES_INC(BSET) 		\
+  if (bitset_stats)					\
+    bitset_stats->types[(BSET)->ops->type].obfrees++
+
+#define BITSET_STATS_LISTS_INC(BSET) 			\
+  if (bitset_stats)					\
+    bitset_stats->types[(BSET)->ops->type].lists++
+
+#define BITSET_STATS_LIST_COUNTS_INC(BSET, I) 		\
+  if (bitset_stats)					\
+    bitset_stats->types[(BSET)->ops->type].list_counts[(I)]++
+
+#define BITSET_STATS_LIST_SIZES_INC(BSET, I) 		\
+  if (bitset_stats)					\
+    bitset_stats->types[(BSET)->ops->type].list_sizes[(I)]++
+
+#define BITSET_STATS_LIST_DENSITY_INC(BSET, I) 		\
+  if (bitset_stats)					\
+    bitset_stats->types[(BSET)->ops->type].list_density[(I)]++
+
+#else
+#define BITSET_STATS_XMALLOCS_INC(TYPE)
+
+#define BITSET_STATS_XFREES_INC(BSET)
+
+#define BITSET_STATS_OBALLOCS_INC(TYPE)
+
+#define BITSET_STATS_OBFREES_INC(BSET)
+
+#define BITSET_STATS_LISTS_INC(BSET)
+
+#define BITSET_STATS_LIST_COUNTS_INC(BSET, I)
+
+#define BITSET_STATS_LIST_SIZES_INC(BSET, I)
+
+#define BITSET_STATS_LIST_DENSITY_INC(BSET, I)
+#endif /* BITSET_STATS  */
+
+
+
+/* Return number of bytes required to create a N_BIT bitset
+   of TYPE.  The bitset may grow to require more bytes than this.  */
+int
+bitset_bytes (type, n_bits)
+     enum bitset_type type;
+     bitset_bindex n_bits;
+{
+  unsigned int bytes;
+
+  switch (type)
+    {
+    case BITSET_ARRAY:
+      bytes = sbitset_bytes (n_bits);
+      break;
+
+    case BITSET_LIST:
+      bytes = lbitset_bytes (n_bits);
+      break;
+
+    case BITSET_TABLE:
+      bytes = ebitset_bytes (n_bits);
+      break;
+
+    default:
+      abort ();
+    }
+
+  return bytes;
+}
+
+
+/* Initialise bitset BSET of TYPE for N_BITS.  */
+bitset
+bitset_init (bset, n_bits, type)
+     bitset bset;
+     bitset_bindex n_bits;
+     enum bitset_type type;
+{
+  switch (type)
+    {
+    case BITSET_ARRAY:
+      return sbitset_init (bset, n_bits);
+
+    case BITSET_LIST:
+      return lbitset_init (bset, n_bits);
+
+    case BITSET_TABLE:
+      return ebitset_init (bset, n_bits);
+
+    default:
+      abort ();
+    }
+}
+
+
+/* Select a bitset type for a set of N_BITS and with attribute hints
+   specified by ATTR.  For variable size bitsets, N_BITS is only a
+   hint and may be zero.  */
+enum bitset_type
+bitset_type_choose (n_bits, attr)
+     bitset_bindex n_bits ATTRIBUTE_UNUSED;
+     unsigned int attr;
+{
+  enum bitset_type type;
+
+#ifdef ENABLE_CHECKING
+  /* Check attributes.  */
+  if (attr & BITSET_FIXED && attr & BITSET_VARIABLE)
+    abort ();
+  if (attr & BITSET_SPARSE && attr & BITSET_DENSE)
+    abort ();
+
+  /* Note that sometimes we will be asked for a zero length
+     fixed size bitset.  */
+#endif
+
+  /* Choose the type of bitset.  */
+
+  type = BITSET_ARRAY;
+  /* Currently, the simple bitsets do not support a variable size.  */
+  if (attr & BITSET_VARIABLE || attr & BITSET_SPARSE)
+    {
+      type = BITSET_LIST;
+      if (attr & BITSET_DENSE || attr & BITSET_GREEDY)
+	type = BITSET_TABLE;
+    }
+
+  return type;
+}
+
+
+/* Create a bitset of N_BITS of type TYPE.  */
+bitset
+bitset_alloc (n_bits, type)
+     bitset_bindex n_bits;
+     enum bitset_type type;
+{
+  unsigned int bytes;
+  bitset bset;
+
+  BITSET_STATS_XMALLOCS_INC (type);
+
+  bytes = bitset_bytes (type, n_bits);
+
+  bset = (bitset) xmalloc (bytes);
+
+  return bitset_init (bset, n_bits, type);
+}
+
+
+/* Create a bitset of N_BITS of type TYPE.  */
+bitset
+bitset_obstack_alloc (bobstack, n_bits, type)
+    struct obstack *bobstack;
+    bitset_bindex n_bits;
+    enum bitset_type type;
+{
+  unsigned int bytes;
+
+  BITSET_STATS_OBALLOCS_INC (type);
+
+  bytes = bitset_bytes (type, n_bits);
+
+  return bitset_init (obstack_alloc (bobstack, bytes), n_bits, type);
+}
+
+
+/* Create a bitset of N_BITS and with attribute hints specified by
+   ATTR.  */
+bitset
+bitset_create (n_bits, attr)
+     bitset_bindex n_bits;
+     unsigned int attr;
+{
+  enum bitset_type type;
+
+  type = bitset_type_choose (n_bits, attr);
+
+  return bitset_alloc (n_bits, type);
+}
+
+
+/* Free bitset BSET.  */
+void
+bitset_free (bset)
+     bitset bset;
+{
+  BITSET_STATS_XFREES_INC (bset);
+
+  if (bset->ops->free)
+    BITSET__FREE (bset);
+
+  bset->ops = NULL;
+  free (bset);
+}
+
+
+/* Free bitset BSET allocated on obstack.  */
+void
+bitset_obstack_free (bset)
+     bitset bset;
+{
+  BITSET_STATS_OBFREES_INC (bset);
+
+  if (bset->ops->free)
+    BITSET__FREE (bset);
+  bset->ops = NULL;
+}
+
+
+/* Find next bit set in SRC starting from and including BITNO.
+   Return -1 if SRC empty.  */
+int
+bitset_next (src, bitno)
+     bitset src;
+     bitset_bindex bitno;
+{
+  bitset_bindex val;
+  bitset_bindex next = bitno;
+
+  if (!bitset_list (src, &val, 1, &next))
+    return -1;
+  return val;
+}
+
+
+/* Find previous bit set in SRC starting from and including BITNO.
+   Return -1 if SRC empty.  */
+int
+bitset_prev (src, bitno)
+     bitset src;
+     bitset_bindex bitno;
+{
+  bitset_bindex val;
+  bitset_bindex next = bitno;
+
+  if (!bitset_reverse_list (src, &val, 1, &next))
+    return -1;
+  return val;
+}
+
+
+/* Find first set bit.   */
+int
+bitset_first (src)
+     bitset src;
+{
+  return bitset_next (src, 0);
+}
+
+
+/* Find last set bit.   */
+int
+bitset_last (src)
+     bitset src;
+{
+  return bitset_prev (src, 0);
+}
+
+
+static void
+bitset_print (file, bset, verbose)
+     FILE *file;
+     bitset bset;
+     int verbose;
+{
+  unsigned int i, pos;
+
+  if (verbose)
+    fprintf (file, "n_bits = %d, set = {", bitset_size (bset));
+
+  pos = 30;
+  BITSET_EXECUTE (bset, 0, i,
+  {
+    if (pos > 70)
+      {
+	fprintf (file, "\n");
+	pos = 0;
+      }
+
+    fprintf (file, "%d ", i);
+    pos += 1 + (i >= 10) + (i >= 100);
+  });
+
+  if (verbose)
+    fprintf (file, "}\n");
+}
+
+
+int
+bitset_copy (dst, src)
+    bitset dst;
+    bitset src;
+{
+    unsigned int i;
+
+    if (dst->ops == src->ops)
+	return BITSET__COPY (dst, src);
+
+    /* Convert bitset types.  We assume that the DST bitset
+       is large enough to hold the SRC bitset.  */
+    bitset_zero (dst);
+    BITSET_EXECUTE (src, 0, i,
+     {
+       bitset_set (dst, i);
+     });
+
+    return 1;
+}
+
+
+/* Return size in bits of bitset SRC.  */
+int
+bitset_size (src)
+    bitset src;
+{
+    return BITSET__SIZE (src);
+}
+
+
+/* DST = 0.  */
+int
+bitset_zero (dst)
+    bitset dst;
+{
+    return BITSET__OP1 (dst, BITSET_ZERO);
+}
+
+
+/* DST = ~0.  */
+int
+bitset_ones (dst)
+    bitset dst;
+{
+    return BITSET__OP1 (dst, BITSET_ONES);
+}
+
+
+/* Return non-zero if all bits in bitset SRC are reset.  */
+int
+bitset_empty_p (src)
+    bitset src;
+{
+    return BITSET__OP1 (src, BITSET_EMPTY_P);
+}
+
+
+/* Return DST == DST | SRC.  */
+int
+bitset_subset_p (dst, src)
+    bitset dst;
+    bitset src;
+{
+    return BITSET__OP2 (dst, src, BITSET_SUBSET_P);
+}
+
+
+/* Return DST == SRC.  */
+int
+bitset_equal_p (dst, src)
+    bitset dst;
+    bitset src;
+{
+    BITSET__CHECK2 (dst, src);
+    return BITSET__OP2 (dst, src, BITSET_EQUAL_P);
+}
+
+
+/* DST = ~SRC.  */
+int
+bitset_not (dst, src)
+    bitset dst;
+    bitset src;
+{
+    BITSET__CHECK2 (dst, src);
+    return BITSET__OP2 (dst, src, BITSET_NOT);
+}
+
+
+/* DST = SRC1 | SRC2.  Return non-zero if DST != SRC1 | SRC2.  */
+int
+bitset_or (dst, src1, src2)
+    bitset dst;
+    bitset src1;
+    bitset src2;
+{
+    BITSET__CHECK3 (dst, src1, src2);
+    return BITSET__OP3 (dst, src1, src2, BITSET_OR);
+}
+
+
+/* DST = SRC1 & SRC2.  Return non-zero if DST != SRC1 & SRC2.  */
+int
+bitset_and (dst, src1, src2)
+    bitset dst;
+    bitset src1;
+    bitset src2;
+{
+    BITSET__CHECK3 (dst, src1, src2);
+    return BITSET__OP3 (dst, src1, src2, BITSET_AND);
+}
+
+
+/* DST = SRC1 ^ SRC2.  Return non-zero if DST != SRC1 ^ SRC2.  */
+int
+bitset_xor (dst, src1, src2)
+    bitset dst;
+    bitset src1;
+    bitset src2;
+{
+    BITSET__CHECK3 (dst, src1, src2);
+    return BITSET__OP3 (dst, src1, src2, BITSET_XOR);
+}
+
+
+/* DST = SRC1 & ~SRC2.  Return non-zero if DST != SRC1 & ~SRC2.  */
+int
+bitset_andn (dst, src1, src2)
+    bitset dst;
+    bitset src1;
+    bitset src2;
+{
+    BITSET__CHECK3 (dst, src1, src2);
+    return BITSET__OP3 (dst, src1, src2, BITSET_ANDN);
+}
+
+
+/* DST = SRC1 | ~SRC2.  Return non-zero if DST != SRC1 | ~SRC2.  */
+int
+bitset_orn (dst, src1, src2)
+    bitset dst;
+    bitset src1;
+    bitset src2;
+{
+    BITSET__CHECK3 (dst, src1, src2);
+    return BITSET__OP3 (dst, src1, src2, BITSET_ORN);
+}
+
+
+/* DST = (SRC1 | SRC2) & SRC3.  Return non-zero if
+   DST != (SRC1 | SRC2) & SRC3.  */
+int
+bitset_or_and (dst, src1, src2, src3)
+    bitset dst;
+    bitset src1;
+    bitset src2;
+    bitset src3;
+{
+    BITSET__CHECK4 (dst, src1, src2, src3);
+    return BITSET__OP4 (dst, src1, src2, src3, BITSET_OR_AND);
+}
+
+
+/* DST = (SRC1 & SRC2) | SRC3.  Return non-zero if
+   DST != (SRC1 & SRC2) | SRC3.  */
+int
+bitset_and_or (dst, src1, src2, src3)
+    bitset dst;
+    bitset src1;
+    bitset src2;
+    bitset src3;
+{
+    BITSET__CHECK4 (dst, src1, src2, src3);
+    return BITSET__OP4 (dst, src1, src2, src3, BITSET_AND_OR);
+}
+
+
+/* Dump bitset BSET to FILE.  */
+void
+bitset_dump (file, bset)
+     FILE *file;
+     bitset bset;
+{
+  bitset_print (file, bset, 0);
+}
+
+
+/* Function to be called from debugger to print bitset.  */
+void
+debug_bitset (bset)
+     bitset bset;
+{
+  bitset_print (stderr, bset, 1);
+}
+
+
+/* Release memory associated with bitsets.  */
+void
+bitset_release_memory ()
+{
+  lbitset_release_memory ();
+  ebitset_release_memory ();
+}
+
+
+#if BITSET_STATS
+int
+bitset_list (bset, list, num, next)
+    bitset bset;
+    bitset_bindex *list;
+    bitset_bindex num;
+    bitset_bindex *next;
+{
+    bitset_bindex count;
+
+    count = BITSET__LIST (bset, list, num, next);
+
+    if (bitset_stats)
+      {
+	bitset_bindex tmp;
+	bitset_bindex size;
+	bitset_bindex i;
+	enum bitset_type type;
+
+	type = bset->ops->type;
+	BITSET_STATS_LISTS_INC (bset);
+
+	/* Log histogram of number of set bits.  */
+	for (i = 0, tmp = count; tmp; tmp >>= 1, i++)
+	  continue;
+	if (i >= BITSET_LOG_COUNT_BINS)
+	  i = BITSET_LOG_COUNT_BINS - 1;
+	BITSET_STATS_LIST_COUNTS_INC (bset, i);
+
+	/* Log histogram of number of bits in set.  */
+	size = bitset_size (bset);
+	for (i = 0, tmp = size; tmp; tmp >>= 1, i++)
+	  continue;
+	if (i >= BITSET_LOG_SIZE_BINS)
+	  i = BITSET_LOG_SIZE_BINS - 1;
+	BITSET_STATS_LIST_SIZES_INC (bset, i);
+
+	/* Histogram of fraction of bits set.  */
+	i = size ? (count * BITSET_DENSITY_BINS) / size : 0;
+	if (i >= BITSET_DENSITY_BINS)
+	  i = BITSET_DENSITY_BINS - 1;
+	BITSET_STATS_LIST_DENSITY_INC (bset, i);
+      }
+    return count;
+}
+
+
+/* Print a percentage histogram with message MSG to FILE.  */
+static void
+bitset_percent_histogram_print (file, name, msg, n_bins, bins)
+     FILE *file;
+     const char *name;
+     const char *msg;
+     unsigned int n_bins;
+     unsigned int *bins;
+{
+  unsigned int i;
+  unsigned int total;
+
+  total = 0;
+  for (i = 0; i < n_bins; i++)
+    total += bins[i];
+
+  if (!total)
+      return;
+
+  fprintf (file, "%s %s", name, msg);
+  for (i = 0; i < n_bins; i++)
+    fprintf (file, "%.0f-%.0f%%\t%8d (%5.1f%%)\n",
+	     i * 100.0 / n_bins,
+	     (i + 1) * 100.0 / n_bins,
+	     bins[i], (100.0 * bins[i]) / total);
+}
+
+
+/* Print a log histogram with message MSG to FILE.  */
+static void
+bitset_log_histogram_print (file, name, msg, n_bins, bins)
+     FILE *file;
+     const char *name;
+     const char *msg;
+     unsigned int n_bins;
+     unsigned int *bins;
+{
+  unsigned int i;
+  unsigned int total;
+  unsigned int max_width;
+
+  total = 0;
+  for (i = 0; i < n_bins; i++)
+    total += bins[i];
+
+  if (!total)
+      return;
+
+  /* 2 * ceil (log10(2) * (N - 1)) + 1  */
+  max_width = 2 * (unsigned int)(0.30103 * (n_bins - 1) + 0.9999) + 1;
+
+  fprintf (file, "%s %s", name, msg);
+  for (i = 0; i < 2; i++)
+    fprintf (file, "%*d\t%8d (%5.1f%%)\n",
+	     max_width, i, bins[i], 100.0 * bins[i] / total);
+
+  /* Perhaps we should bail out once the histogram goes to zero.  */
+  for (; i < n_bins; i++)
+    fprintf (file, "%*d-%d\t%8d (%5.1f%%)\n",
+	     max_width - ((unsigned int) (0.30103 * (i) + 0.9999) + 1),
+	     1 << (i - 1), (1 << i) - 1, bins[i], (100.0 * bins[i]) / total);
+}
+
+
+/* Print bitset statistics to FILE.  */
+static void
+bitset_stats_print_1 (file, name, stats)
+     FILE *file;
+     const char *name;
+     struct bitset_type_stats_struct *stats;
+{
+  if (!stats)
+    return;
+
+  fprintf (file, "%d %ss xmalloced, %d freed.\n",
+	   stats->xmallocs, name, stats->xfrees);
+  fprintf (file, "%d %ss oballoced, %d freed.\n",
+	   stats->oballocs, name, stats->obfrees);
+
+  fprintf (file, "%d bitset_lists\n", stats->lists);
+
+  bitset_log_histogram_print (file, name, "count log histogram\n",
+	   BITSET_LOG_COUNT_BINS, stats->list_counts);
+
+  bitset_log_histogram_print (file, name, "size log histogram\n",
+	   BITSET_LOG_SIZE_BINS, stats->list_sizes);
+
+  bitset_percent_histogram_print (file, name, "density histogram\n",
+				  BITSET_DENSITY_BINS, stats->list_density);
+}
+
+
+/* Print all bitset statistics to FILE.  */
+static void
+bitset_stats_print (file, verbose)
+     FILE *file;
+     int verbose ATTRIBUTE_UNUSED;
+{
+  int i;
+  static const char *names[] = BITSET__TYPE_NAMES;
+
+  if (!bitset_stats)
+    return;
+
+  fprintf (file, "Bitset statistics:\n\n");
+
+  if (bitset_stats->runs > 1)
+    fprintf (file, "Accumulated runs = %d\n", bitset_stats->runs);
+
+  for (i = 0; i < BITSET_TYPE_NUM; i++)
+      bitset_stats_print_1 (file, names[i], &bitset_stats->types[i]);
+}
+#endif /* BITSET_STATS  */
+
+
+/* Initialise bitset statistics logging.  */
+void
+bitset_stats_init ()
+{
+#if BITSET_STATS
+    bitset_stats = &bitset_stats_data;
+    bitset_stats_read ();
+#endif  /* BITSET_STATS  */
+}
+
+
+/* Read bitset statistics file.  */
+static void
+bitset_stats_read ()
+{
+    FILE *file;
+
+    if (!bitset_stats)
+      return;
+
+    file = fopen (BITSET_STATS_FILE, "r");
+    if (file)
+      {
+	if (fread (&bitset_stats_data, sizeof (bitset_stats_data),
+		   1, file) != 1)
+	  {
+	    if (ferror (file))
+	      perror ("Could not read stats file");
+	    else
+	      fprintf (stderr, "Bad stats file size\n");
+	  }
+	fclose (file);
+      }
+    bitset_stats_data.runs++;
+}
+
+
+/* Write bitset statistics file.  */
+static void
+bitset_stats_write ()
+{
+    FILE *file;
+
+    if (!bitset_stats)
+      return;
+
+    file = fopen (BITSET_STATS_FILE, "w");
+    if (file)
+      {
+	if (fwrite (&bitset_stats_data, sizeof (bitset_stats_data),
+		    1, file) != 1)
+	  perror ("Could not write stats file");
+	fclose (file);
+      }
+    else
+      perror ("Could not open stats file for writing");
+}
+
+
+/* Dump bitset statistics to FILE.  */
+void
+bitset_stats_dump (file)
+     FILE *file;
+{
+#if BITSET_STATS
+  bitset_stats_print (file, 0);
+  bitset_stats_write ();
+#endif /* BITSET_STATS  */
+}
+
+
+/* Function to be called from debugger to print bitset stats.  */
+void
+debug_bitset_stats (void)
+{
+#if BITSET_STATS
+  bitset_stats_print (stderr, 1);
+#endif /* BITSET_STATS  */
+}