2006-12-27 Daniel Berlin <dberlin@dberlin.org>

	* sbitmap.c (BITMAP_DEBUGGING): New macro.
	(do_popcount): Ditto.
	(sbitmap_verify_popcount): New function.
	(sbitmap_alloc): Set popcount to NULL, remove set of bytes
	member.
	(sbitmap_alloc_with_popcount): New function.
	(sbitmap_resize): Remove uses of bytes member and update
	popcount.
	(sbitmap_realloc): Remove uses of bytes member.
	(sbitmap_copy): Copy popcount.
	(sbitmap_copy_n): New function.
	(sbitmap_zero): Update popcount cache.
	(sbitmap_ones): Ditto.
	(sbitmap_a_and_b): Ditto.
	(sbitmap_a_or_b): Ditto.
	(sbitmap_a_xor_b): Ditto.
	(sbitmap_union_of_diff_cg): Assert non-existence of popcount
	cache.
	(sbitmap_union_of_diff): Ditto.
	(sbitmap_not): Ditto.
	(sbitmap_difference): Ditto.
	(sbitmap_a_and_b_cg): Ditto.
	(sbitmap_a_xor_b_cg): Ditto.
	(sbitmap_a_or_b_cg): Ditto.
	(sbitmap_a_or_b_and_c_cg): Ditto.
	(sbitmap_a_and_b_or_c_cg): Ditto.
	(sbitmap_intersection_of_succs): Ditto.
	(sbitmap_intersection_of_preds): Ditto.
	(sbitmap_union_of_succs): Ditto.
	(sbitmap_union_of_preds): Ditto.
	(popcount_table): New.
	(sbitmap_elt_popcount): New function.
	(sbitmap_popcount): Ditto.

	* sbitmap.h (sbitmap): Remove bytes member.
	Add popcount member.
	(SET_BIT): Macro turned into function.
	(RESET_BIT): Ditto.
	(SBITMAP_SIZE_BYTES): New macro.
	(sbitmap_free): Free popcount too.
	(sbitmap_alloc_with_popcount): New prototype.
	(sbitmap_copy_n): Ditto.
	(sbitmap_verify_popcount): Ditto.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@120237 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 353 insertions, 28 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6a9a3377994..041f51adbbb 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,49 @@
+2006-12-27  Daniel Berlin  <dberlin@dberlin.org>
+
+	* sbitmap.c (BITMAP_DEBUGGING): New macro.
+	(do_popcount): Ditto.
+	(sbitmap_verify_popcount): New function.
+	(sbitmap_alloc): Set popcount to NULL, remove set of bytes
+	member.
+	(sbitmap_alloc_with_popcount): New function.
+	(sbitmap_resize): Remove uses of bytes member and update
+	popcount.
+	(sbitmap_realloc): Remove uses of bytes member.
+	(sbitmap_copy): Copy popcount.
+	(sbitmap_copy_n): New function.
+	(sbitmap_zero): Update popcount cache.
+	(sbitmap_ones): Ditto.
+	(sbitmap_a_and_b): Ditto.
+	(sbitmap_a_or_b): Ditto.
+	(sbitmap_a_xor_b): Ditto.
+	(sbitmap_union_of_diff_cg): Assert non-existence of popcount
+	cache.
+	(sbitmap_union_of_diff): Ditto.
+	(sbitmap_not): Ditto.
+	(sbitmap_difference): Ditto.
+	(sbitmap_a_and_b_cg): Ditto.
+	(sbitmap_a_xor_b_cg): Ditto.
+	(sbitmap_a_or_b_cg): Ditto.
+	(sbitmap_a_or_b_and_c_cg): Ditto.
+	(sbitmap_a_and_b_or_c_cg): Ditto.
+	(sbitmap_intersection_of_succs): Ditto.
+	(sbitmap_intersection_of_preds): Ditto.
+	(sbitmap_union_of_succs): Ditto.
+	(sbitmap_union_of_preds): Ditto.
+	(popcount_table): New.
+	(sbitmap_elt_popcount): New function.
+	(sbitmap_popcount): Ditto.
+
+	* sbitmap.h (sbitmap): Remove bytes member.
+	Add popcount member.
+	(SET_BIT): Macro turned into function.
+	(RESET_BIT): Ditto.
+	(SBITMAP_SIZE_BYTES): New macro.
+	(sbitmap_free): Free popcount too.
+	(sbitmap_alloc_with_popcount): New prototype.
+	(sbitmap_copy_n): Ditto.
+	(sbitmap_verify_popcount): Ditto.
+
 2006-12-27  Ian Lance Taylor  <iant@google.com>
 
 	PR debug/26964
diff --git a/gcc/sbitmap.c b/gcc/sbitmap.c
index 5ef7f08d2c5..a32364f0f7e 100644
--- a/gcc/sbitmap.c
+++ b/gcc/sbitmap.c
@@ -28,6 +28,43 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
 #include "obstack.h"
 #include "basic-block.h"
 
+#if GCC_VERSION >= 3400
+#if HOST_BITS_PER_WIDEST_FAST_INT == HOST_BITS_PER_LONG
+#define do_popcount(x) __builtin_popcountl(x)
+#elif HOST_BITS_PER_WIDEST_FAST_INT == HOST_BITS_PER_LONG_LONG
+#define do_popcount(x) __builtin_popcountll(x)
+#else
+#error "internal error: sbitmap.h and hwint.h are inconsistent"
+#endif
+#else
+static unsigned long sbitmap_elt_popcount (SBITMAP_ELT_TYPE);
+#define do_popcount(x) sbitmap_elt_popcount((x))
+#endif
+
+/* This macro controls debugging that is as expensive as the
+   operations it verifies.  */
+
+/* #define BITMAP_DEBUGGING  */
+#ifdef BITMAP_DEBUGGING
+
+/* Verify the population count of sbitmap A matches the cached value,
+   if there is a cached value. */
+
+void
+sbitmap_verify_popcount (sbitmap a)
+{
+  unsigned ix;
+  unsigned int lastword;
+  
+  if (!a->popcount)
+    return;
+
+  lastword = a->size;
+  for (ix = 0; ix < lastword; ix++)
+    gcc_assert (a->popcount[ix] == do_popcount (a->elms[ix]));
+}
+#endif
+
 /* Bitmap manipulation routines.  */
 
 /* Allocate a simple bitmap of N_ELMS bits.  */
@@ -45,7 +82,19 @@ sbitmap_alloc (unsigned int n_elms)
   bmap = xmalloc (amt);
   bmap->n_bits = n_elms;
   bmap->size = size;
-  bmap->bytes = bytes;
+  bmap->popcount = NULL;
+  return bmap;
+}
+
+/* Allocate a simple bitmap of N_ELMS bits, and a popcount array.  */
+
+sbitmap
+sbitmap_alloc_with_popcount (unsigned int n_elms)
+{
+  sbitmap bmap;
+  
+  bmap = sbitmap_alloc (n_elms);  
+  bmap->popcount = xmalloc (bmap->size * sizeof (unsigned char));
   return bmap;
 }
 
@@ -61,18 +110,22 @@ sbitmap_resize (sbitmap bmap, unsigned int n_elms, int def)
 
   size = SBITMAP_SET_SIZE (n_elms);
   bytes = size * sizeof (SBITMAP_ELT_TYPE);
-  if (bytes > bmap->bytes)
+  if (bytes > SBITMAP_SIZE_BYTES (bmap))
     {
       amt = (sizeof (struct simple_bitmap_def)
 	    + bytes - sizeof (SBITMAP_ELT_TYPE));
       bmap = xrealloc (bmap, amt);
+      if (bmap->popcount)
+	bmap->popcount = xrealloc (bmap->popcount,
+				   size * sizeof (unsigned char));
     }
 
   if (n_elms > bmap->n_bits)
     {
       if (def)
 	{
-	  memset (bmap->elms + bmap->size, -1, bytes - bmap->bytes);
+	  memset (bmap->elms + bmap->size, -1, 
+		  bytes - SBITMAP_SIZE_BYTES (bmap));
 
 	  /* Set the new bits if the original last element.  */
 	  last_bit = bmap->n_bits % SBITMAP_ELT_BITS;
@@ -87,20 +140,31 @@ sbitmap_resize (sbitmap bmap, unsigned int n_elms, int def)
 	      &= (SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - last_bit);
 	}
       else
-	memset (bmap->elms + bmap->size, 0, bytes - bmap->bytes);
+	{
+	  memset (bmap->elms + bmap->size, 0, 
+		  bytes - SBITMAP_SIZE_BYTES (bmap));
+	  if (bmap->popcount)
+	    memset (bmap->popcount + bmap->size, 0,
+		    (size * sizeof (unsigned char)) 
+		    - (bmap->size * sizeof (unsigned char)));
+		    
+	}
     }
   else if (n_elms < bmap->n_bits)
     {
       /* Clear the surplus bits in the last word.  */
       last_bit = n_elms % SBITMAP_ELT_BITS;
       if (last_bit)
-	bmap->elms[size - 1]
-	  &= (SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - last_bit);
+	{
+	  bmap->elms[size - 1]
+	    &= (SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - last_bit);
+	  if (bmap->popcount)
+	    bmap->popcount[size - 1] = do_popcount (bmap->elms[size - 1]);
+	}
     }
 
   bmap->n_bits = n_elms;
   bmap->size = size;
-  bmap->bytes = bytes;
   return bmap;
 }
 
@@ -117,7 +181,7 @@ sbitmap_realloc (sbitmap src, unsigned int n_elms)
   amt = (sizeof (struct simple_bitmap_def)
 	 + bytes - sizeof (SBITMAP_ELT_TYPE));
 
-  if (src->bytes  >= bytes)
+  if (SBITMAP_SIZE_BYTES (src)  >= bytes)
     {
       src->n_bits = n_elms;
       return src;
@@ -126,7 +190,6 @@ sbitmap_realloc (sbitmap src, unsigned int n_elms)
   bmap = (sbitmap) xrealloc (src, amt);
   bmap->n_bits = n_elms;
   bmap->size = size;
-  bmap->bytes = bytes;
   return bmap;
 }
 
@@ -166,7 +229,7 @@ sbitmap_vector_alloc (unsigned int n_vecs, unsigned int n_elms)
       bitmap_vector[i] = b;
       b->n_bits = n_elms;
       b->size = size;
-      b->bytes = bytes;
+      b->popcount = NULL;
     }
 
   return bitmap_vector;
@@ -178,6 +241,18 @@ void
 sbitmap_copy (sbitmap dst, sbitmap src)
 {
   memcpy (dst->elms, src->elms, sizeof (SBITMAP_ELT_TYPE) * dst->size);
+  if (dst->popcount)
+    memcpy (dst->popcount, src->popcount, sizeof (unsigned char) * dst->size);
+}
+
+/* Copy the first N elements of sbitmap SRC to DST.  */
+
+void
+sbitmap_copy_n (sbitmap dst, sbitmap src, unsigned int n)
+{
+  memcpy (dst->elms, src->elms, sizeof (SBITMAP_ELT_TYPE) * n);  
+  if (dst->popcount)
+    memcpy (dst->popcount, src->popcount, sizeof (unsigned char) * n);
 }
 
 /* Determine if a == b.  */
@@ -192,7 +267,9 @@ sbitmap_equal (sbitmap a, sbitmap b)
 void
 sbitmap_zero (sbitmap bmap)
 {
-  memset (bmap->elms, 0, bmap->bytes);
+  memset (bmap->elms, 0, SBITMAP_SIZE_BYTES (bmap));
+  if (bmap->popcount)
+    memset (bmap->popcount, 0, bmap->size * sizeof (unsigned char));
 }
 
 /* Set all elements in a bitmap to ones.  */
@@ -202,12 +279,19 @@ sbitmap_ones (sbitmap bmap)
 {
   unsigned int last_bit;
 
-  memset (bmap->elms, -1, bmap->bytes);
+  memset (bmap->elms, -1, SBITMAP_SIZE_BYTES (bmap));
+  if (bmap->popcount)
+    memset (bmap->popcount, -1, bmap->size * sizeof (unsigned char));
 
   last_bit = bmap->n_bits % SBITMAP_ELT_BITS;
   if (last_bit)
-    bmap->elms[bmap->size - 1]
-      = (SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - last_bit);
+    {
+      bmap->elms[bmap->size - 1]
+	= (SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - last_bit);
+      if (bmap->popcount)
+	bmap->popcount[bmap->size - 1] 
+	  = do_popcount (bmap->elms[bmap->size - 1]);
+    }
 }
 
 /* Zero a vector of N_VECS bitmaps.  */
@@ -246,6 +330,8 @@ sbitmap_union_of_diff_cg (sbitmap dst, sbitmap a, sbitmap b, sbitmap c)
   sbitmap_ptr cp = c->elms;
   SBITMAP_ELT_TYPE changed = 0;
 
+  gcc_assert (!dst->popcount);
+  
   for (i = 0; i < n; i++)
     {
       SBITMAP_ELT_TYPE tmp = *ap++ | (*bp++ & ~*cp++);
@@ -265,6 +351,9 @@ sbitmap_union_of_diff (sbitmap dst, sbitmap a, sbitmap b, sbitmap c)
   sbitmap_ptr bp = b->elms;
   sbitmap_ptr cp = c->elms;
 
+  gcc_assert (!dst->popcount && !a->popcount
+	      && !b->popcount && !c->popcount);
+
   for (i = 0; i < n; i++)
     *dstp++ = *ap++ | (*bp++ & ~*cp++);
 }
@@ -279,6 +368,8 @@ sbitmap_not (sbitmap dst, sbitmap src)
   sbitmap_ptr srcp = src->elms;
   unsigned int last_bit;
 
+  gcc_assert (!dst->popcount);  
+
   for (i = 0; i < n; i++)
     *dstp++ = ~*srcp++;
 
@@ -301,6 +392,8 @@ sbitmap_difference (sbitmap dst, sbitmap a, sbitmap b)
   sbitmap_ptr ap = a->elms;
   sbitmap_ptr bp = b->elms;
 
+  gcc_assert (!dst->popcount);
+
   /* A should be at least as large as DEST, to have a defined source.  */
   gcc_assert (a->size >= dst_size);
   /* If minuend is smaller, we simply pretend it to be zero bits, i.e.
@@ -346,6 +439,8 @@ sbitmap_a_and_b_cg (sbitmap dst, sbitmap a, sbitmap b)
   sbitmap_ptr bp = b->elms;
   SBITMAP_ELT_TYPE changed = 0;
 
+  gcc_assert (!dst->popcount);
+
   for (i = 0; i < n; i++)
     {
       SBITMAP_ELT_TYPE tmp = *ap++ & *bp++;
@@ -363,9 +458,25 @@ sbitmap_a_and_b (sbitmap dst, sbitmap a, sbitmap b)
   sbitmap_ptr dstp = dst->elms;
   sbitmap_ptr ap = a->elms;
   sbitmap_ptr bp = b->elms;
+  bool has_popcount = dst->popcount != NULL;
+  unsigned char *popcountp = dst->popcount;
 
   for (i = 0; i < n; i++)
-    *dstp++ = *ap++ & *bp++;
+    {
+      SBITMAP_ELT_TYPE tmp = *ap++ & *bp++;
+      if (has_popcount)
+	{
+	  bool wordchanged = (*dstp ^ tmp) != 0;
+	  if (wordchanged)
+	    *popcountp = do_popcount (tmp);
+	  popcountp++;
+	}      
+      *dstp++ = tmp;
+    }
+#ifdef BITMAP_DEBUGGING
+  if (has_popcount)
+    sbitmap_verify_popcount (dst);
+#endif
 }
 
 /* Set DST to be (A xor B)).
@@ -379,6 +490,8 @@ sbitmap_a_xor_b_cg (sbitmap dst, sbitmap a, sbitmap b)
   sbitmap_ptr ap = a->elms;
   sbitmap_ptr bp = b->elms;
   SBITMAP_ELT_TYPE changed = 0;
+  
+  gcc_assert (!dst->popcount);
 
   for (i = 0; i < n; i++)
     {
@@ -397,9 +510,25 @@ sbitmap_a_xor_b (sbitmap dst, sbitmap a, sbitmap b)
   sbitmap_ptr dstp = dst->elms;
   sbitmap_ptr ap = a->elms;
   sbitmap_ptr bp = b->elms;
+  bool has_popcount = dst->popcount != NULL;
+  unsigned char *popcountp = dst->popcount;
 
   for (i = 0; i < n; i++)
-    *dstp++ = *ap++ ^ *bp++;
+    {
+      SBITMAP_ELT_TYPE tmp = *ap++ ^ *bp++;
+      if (has_popcount)
+	{
+	  bool wordchanged = (*dstp ^ tmp) != 0;
+	  if (wordchanged)
+	    *popcountp = do_popcount (tmp);
+	  popcountp++;
+	} 
+      *dstp++ = tmp;
+    }
+#ifdef BITMAP_DEBUGGING
+  if (has_popcount)
+    sbitmap_verify_popcount (dst);
+#endif
 }
 
 /* Set DST to be (A or B)).
@@ -414,6 +543,8 @@ sbitmap_a_or_b_cg (sbitmap dst, sbitmap a, sbitmap b)
   sbitmap_ptr bp = b->elms;
   SBITMAP_ELT_TYPE changed = 0;
 
+  gcc_assert (!dst->popcount);
+
   for (i = 0; i < n; i++)
     {
       SBITMAP_ELT_TYPE tmp = *ap++ | *bp++;
@@ -431,9 +562,25 @@ sbitmap_a_or_b (sbitmap dst, sbitmap a, sbitmap b)
   sbitmap_ptr dstp = dst->elms;
   sbitmap_ptr ap = a->elms;
   sbitmap_ptr bp = b->elms;
+  bool has_popcount = dst->popcount != NULL;
+  unsigned char *popcountp = dst->popcount;
 
   for (i = 0; i < n; i++)
-    *dstp++ = *ap++ | *bp++;
+    {
+      SBITMAP_ELT_TYPE tmp = *ap++ | *bp++;
+      if (has_popcount)
+	{
+	  bool wordchanged = (*dstp ^ tmp) != 0;
+	  if (wordchanged)
+	    *popcountp = do_popcount (tmp);
+	  popcountp++;
+	} 
+      *dstp++ = tmp;
+    }
+#ifdef BITMAP_DEBUGGING
+  if (has_popcount)
+    sbitmap_verify_popcount (dst);
+#endif
 }
 
 /* Return nonzero if A is a subset of B.  */
@@ -464,6 +611,8 @@ sbitmap_a_or_b_and_c_cg (sbitmap dst, sbitmap a, sbitmap b, sbitmap c)
   sbitmap_ptr cp = c->elms;
   SBITMAP_ELT_TYPE changed = 0;
 
+  gcc_assert (!dst->popcount);
+
   for (i = 0; i < n; i++)
     {
       SBITMAP_ELT_TYPE tmp = *ap++ | (*bp++ & *cp++);
@@ -483,6 +632,8 @@ sbitmap_a_or_b_and_c (sbitmap dst, sbitmap a, sbitmap b, sbitmap c)
   sbitmap_ptr bp = b->elms;
   sbitmap_ptr cp = c->elms;
 
+  gcc_assert (!dst->popcount);
+
   for (i = 0; i < n; i++)
     *dstp++ = *ap++ | (*bp++ & *cp++);
 }
@@ -500,6 +651,8 @@ sbitmap_a_and_b_or_c_cg (sbitmap dst, sbitmap a, sbitmap b, sbitmap c)
   sbitmap_ptr cp = c->elms;
   SBITMAP_ELT_TYPE changed = 0;
 
+  gcc_assert (!dst->popcount);
+
   for (i = 0; i < n; i++)
     {
       SBITMAP_ELT_TYPE tmp = *ap++ & (*bp++ | *cp++);
@@ -535,6 +688,8 @@ sbitmap_intersection_of_succs (sbitmap dst, sbitmap *src, int bb)
   edge e;
   unsigned ix;
 
+  gcc_assert (!dst->popcount);
+
   for (e = NULL, ix = 0; ix < EDGE_COUNT (b->succs); ix++)
     {
       e = EDGE_SUCC (b, ix);
@@ -575,6 +730,8 @@ sbitmap_intersection_of_preds (sbitmap dst, sbitmap *src, int bb)
   edge e;
   unsigned ix;
 
+  gcc_assert (!dst->popcount);
+
   for (e = NULL, ix = 0; ix < EDGE_COUNT (b->preds); ix++)
     {
       e = EDGE_PRED (b, ix);
@@ -615,6 +772,8 @@ sbitmap_union_of_succs (sbitmap dst, sbitmap *src, int bb)
   edge e;
   unsigned ix;
 
+  gcc_assert (!dst->popcount);
+
   for (ix = 0; ix < EDGE_COUNT (b->succs); ix++)
     {
       e = EDGE_SUCC (b, ix);
@@ -655,6 +814,8 @@ sbitmap_union_of_preds (sbitmap dst, sbitmap *src, int bb)
   edge e;
   unsigned ix;
 
+  gcc_assert (!dst->popcount);
+
   for (ix = 0; ix < EDGE_COUNT (b->preds); ix++)
     {
       e = EDGE_PRED (b, ix);
@@ -795,3 +956,82 @@ dump_sbitmap_vector (FILE *file, const char *title, const char *subtitle,
 
   fprintf (file, "\n");
 }
+
+#if GCC_VERSION < 3400
+/* Table of number of set bits in a character, indexed by value of char.  */
+static unsigned char popcount_table[] =
+{
+    0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+    1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+    1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+    1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+    3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8,
+};
+
+/* Count the bits in an SBITMAP element A.  */
+
+static unsigned long
+sbitmap_elt_popcount (SBITMAP_ELT_TYPE a)
+{
+  unsigned long ret = 0;
+  unsigned i;
+
+  if (a == 0)
+    return 0;
+
+  /* Just do this the table way for now  */
+  for (i = 0; i < SBITMAP_ELT_BITS; i += 8)
+    ret += popcount_table[(a >> i) & 0xff];
+  return ret;
+}
+#endif
+
+/* Count the number of bits in SBITMAP a, up to bit MAXBIT.  */
+
+unsigned long
+sbitmap_popcount (sbitmap a, unsigned long maxbit)
+{
+  unsigned long count = 0;
+  unsigned ix;
+  unsigned int lastword;
+
+  if (maxbit == 0)
+    return 0;
+  
+  if (maxbit >= a->n_bits)
+    maxbit = a->n_bits;
+
+  /* Count the bits in the full word.  */
+  lastword = MIN (a->size, SBITMAP_SET_SIZE (maxbit + 1) - 1);
+  for (ix = 0; ix < lastword; ix++)
+    {
+      if (a->popcount)
+	{
+	  count += a->popcount[ix];
+#ifdef BITMAP_DEBUGGING
+	  gcc_assert (a->popcount[ix] == do_popcount (a->elms[ix]));
+#endif
+	}
+      else
+	count += do_popcount (a->elms[ix]);
+    }
+
+  /* Count the remaining bits.  */
+  if (lastword < a->size)
+    {
+      unsigned int bitindex;
+      SBITMAP_ELT_TYPE theword = a->elms[lastword];
+
+      bitindex = maxbit % SBITMAP_ELT_BITS;
+      if (bitindex != 0)
+	{
+	  theword &= (SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - bitindex);
+	  count += do_popcount (theword);
+	}
+    }
+  return count;
+}
+
diff --git a/gcc/sbitmap.h b/gcc/sbitmap.h
index 21c697451e2..aacc665f4e7 100644
--- a/gcc/sbitmap.h
+++ b/gcc/sbitmap.h
@@ -28,11 +28,19 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
 #define SBITMAP_ELT_BITS ((unsigned) HOST_BITS_PER_WIDEST_FAST_INT)
 #define SBITMAP_ELT_TYPE unsigned HOST_WIDEST_FAST_INT
 
+/* Can't use SBITMAP_ELT_BITS in this macro because it contains a
+   cast.  There is no perfect macro in GCC to test against.  This
+   suffices for roughly 99% of the hosts we run on, and the rest
+   don't have 256 bit integers.  */
+#if HOST_BITS_PER_WIDEST_FAST_INT > 255
+#error Need to increase size of datatype used for popcount
+#endif
+
 typedef struct simple_bitmap_def
 {
+  unsigned char *popcount;      /* Population count.  */
   unsigned int n_bits;		/* Number of bits.  */
   unsigned int size;		/* Size in elements.  */
-  unsigned int bytes;		/* Size in bytes.  */
   SBITMAP_ELT_TYPE elms[1];	/* The elements.  */
 } *sbitmap;
 
@@ -40,20 +48,47 @@ typedef SBITMAP_ELT_TYPE *sbitmap_ptr;
 
 /* Return the set size needed for N elements.  */
 #define SBITMAP_SET_SIZE(N) (((N) + SBITMAP_ELT_BITS - 1) / SBITMAP_ELT_BITS)
-
-/* Set bit number bitno in the bitmap.  */
-#define SET_BIT(BITMAP, BITNO)					\
-  ((BITMAP)->elms [(BITNO) / SBITMAP_ELT_BITS]			\
-   |= (SBITMAP_ELT_TYPE) 1 << (BITNO) % SBITMAP_ELT_BITS)
+#define SBITMAP_SIZE_BYTES(BITMAP) ((BITMAP)->size * sizeof (SBITMAP_ELT_TYPE))
 
 /* Test if bit number bitno in the bitmap is set.  */
 #define TEST_BIT(BITMAP, BITNO) \
 ((BITMAP)->elms [(BITNO) / SBITMAP_ELT_BITS] >> (BITNO) % SBITMAP_ELT_BITS & 1)
 
-/* Reset bit number bitno in the bitmap.  */
-#define RESET_BIT(BITMAP, BITNO)				\
-  ((BITMAP)->elms [(BITNO) / SBITMAP_ELT_BITS]			\
-   &= ~((SBITMAP_ELT_TYPE) 1 << (BITNO) % SBITMAP_ELT_BITS))
+/* Set bit number BITNO in the sbitmap MAP.  Updates population count
+   if this bitmap has one.  */
+
+static inline void
+SET_BIT (sbitmap map, unsigned int bitno)
+{
+  if (map->popcount)
+    {
+      bool oldbit;
+      oldbit = TEST_BIT (map, bitno);
+      if (!oldbit)
+	map->popcount[bitno / SBITMAP_ELT_BITS]++;
+    }
+  map->elms[bitno / SBITMAP_ELT_BITS]
+    |= (SBITMAP_ELT_TYPE) 1 << (bitno) % SBITMAP_ELT_BITS;
+}
+
+
+
+/* Reset bit number BITNO in the sbitmap MAP.  Updates population
+   count if this bitmap has one.  */
+
+static inline void
+RESET_BIT (sbitmap map,  unsigned int bitno)
+{
+  if (map->popcount)
+    {
+      bool oldbit;
+      oldbit = TEST_BIT (map, bitno);
+      if (oldbit)
+	map->popcount[bitno / SBITMAP_ELT_BITS]--;
+    }
+  map->elms[bitno / SBITMAP_ELT_BITS]
+    &= ~((SBITMAP_ELT_TYPE) 1 << (bitno) % SBITMAP_ELT_BITS);
+}
 
 /* The iterator for sbitmap.  */
 typedef struct {
@@ -165,7 +200,7 @@ do {									\
     }									\
 } while (0)
 
-#define sbitmap_free(MAP)		free(MAP)
+#define sbitmap_free(MAP)		(free((MAP)->popcount), free((MAP)))
 #define sbitmap_vector_free(VEC)	free(VEC)
 
 struct int_list;
@@ -175,9 +210,11 @@ extern void dump_sbitmap_file (FILE *, sbitmap);
 extern void dump_sbitmap_vector (FILE *, const char *, const char *, sbitmap *,
 				 int);
 extern sbitmap sbitmap_alloc (unsigned int);
+extern sbitmap sbitmap_alloc_with_popcount (unsigned int);
 extern sbitmap *sbitmap_vector_alloc (unsigned int, unsigned int);
 extern sbitmap sbitmap_resize (sbitmap, unsigned int, int);
 extern void sbitmap_copy (sbitmap, sbitmap);
+extern void sbitmap_copy_n (sbitmap, sbitmap, unsigned int);
 extern int sbitmap_equal (sbitmap, sbitmap);
 extern void sbitmap_zero (sbitmap);
 extern void sbitmap_ones (sbitmap);
@@ -224,4 +261,6 @@ extern void sbitmap_union_of_preds (sbitmap, sbitmap *, int);
 
 extern void debug_sbitmap (sbitmap);
 extern sbitmap sbitmap_realloc (sbitmap, unsigned int);
+extern unsigned long sbitmap_popcount(sbitmap, unsigned long);
+extern void sbitmap_verify_popcount (sbitmap);
 #endif /* ! GCC_SBITMAP_H */