PR middle-end/20219

[pf3gnuchains/gcc-fork.git] / gcc / bitmap.h

diff --git a/gcc/bitmap.h b/gcc/bitmap.h
index f20773b..3400c05 100644 (file)
--- a/gcc/bitmap.h
+++ b/gcc/bitmap.h
@@ -1,5 +1,5 @@
 /* Functions to support general ended bitmaps.
 /* Functions to support general ended bitmaps.

-   Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
+   Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005

    Free Software Foundation, Inc.
 
 This file is part of GCC.
    Free Software Foundation, Inc.
 
 This file is part of GCC.


@@ -16,37 +16,48 @@ for more details.
 
 You should have received a copy of the GNU General Public License
 along with GCC; see the file COPYING.  If not, write to the Free
 
 You should have received a copy of the GNU General Public License
 along with GCC; see the file COPYING.  If not, write to the Free

-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA.  */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.  */

 
 #ifndef GCC_BITMAP_H
 #define GCC_BITMAP_H
 
 /* Fundamental storage type for bitmap.  */
 
 
 #ifndef GCC_BITMAP_H
 #define GCC_BITMAP_H
 
 /* Fundamental storage type for bitmap.  */
 

-/* typedef unsigned HOST_WIDE_INT BITMAP_WORD; */
-/* #define nBITMAP_WORD_BITS HOST_BITS_PER_WIDE_INT */

 typedef unsigned long BITMAP_WORD;
 typedef unsigned long BITMAP_WORD;

-#define nBITMAP_WORD_BITS (CHAR_BIT * SIZEOF_LONG)
-#define BITMAP_WORD_BITS (unsigned) nBITMAP_WORD_BITS
+/* BITMAP_WORD_BITS needs to be unsigned, but cannot contain casts as
+   it is used in preprocessor directives -- hence the 1u.  */
+#define BITMAP_WORD_BITS (CHAR_BIT * SIZEOF_LONG * 1u)

 
 /* Number of words to use for each element in the linked list.  */
 
 #ifndef BITMAP_ELEMENT_WORDS
 
 /* Number of words to use for each element in the linked list.  */
 
 #ifndef BITMAP_ELEMENT_WORDS

-#define BITMAP_ELEMENT_WORDS ((128 + nBITMAP_WORD_BITS - 1) / nBITMAP_WORD_BITS)
+#define BITMAP_ELEMENT_WORDS ((128 + BITMAP_WORD_BITS - 1) / BITMAP_WORD_BITS)

 #endif
 
 #endif
 

-/* Number of bits in each actual element of a bitmap.  We get slightly better
-   code for bit % BITMAP_ELEMENT_ALL_BITS and bit / BITMAP_ELEMENT_ALL_BITS if
-   bits is unsigned, assuming it is a power of 2.  */
+/* Number of bits in each actual element of a bitmap.  */

 
 

-#define BITMAP_ELEMENT_ALL_BITS \
-  ((unsigned) (BITMAP_ELEMENT_WORDS * BITMAP_WORD_BITS))
+#define BITMAP_ELEMENT_ALL_BITS (BITMAP_ELEMENT_WORDS * BITMAP_WORD_BITS)
+
+/* Obstack for allocating bitmaps and elements from.  */
+typedef struct bitmap_obstack GTY (())
+{
+  struct bitmap_element_def *elements;
+  struct bitmap_head_def *heads;
+  struct obstack GTY ((skip)) obstack;
+} bitmap_obstack;

 
 /* Bitmap set element.  We use a linked list to hold only the bits that
    are set.  This allows for use to grow the bitset dynamically without
 
 /* Bitmap set element.  We use a linked list to hold only the bits that
    are set.  This allows for use to grow the bitset dynamically without

-   having to realloc and copy a giant bit array.  The `prev' field is
-   undefined for an element on the free list.  */
+   having to realloc and copy a giant bit array.  
+
+   The free list is implemented as a list of lists.  There is one
+   outer list connected together by prev fields.  Each element of that
+   outer is an inner list (that may consist only of the outer list
+   element) that are connected by the next fields.  The prev pointer
+   is undefined for interior elements.  This allows
+   bitmap_elt_clear_from to be implemented in unit time rather than
+   linear in the number of elements to be freed.  */

 
 typedef struct bitmap_element_def GTY(())
 {
 
 typedef struct bitmap_element_def GTY(())
 {


@@ -61,22 +72,16 @@ typedef struct bitmap_head_def GTY(()) {
   bitmap_element *first;       /* First element in linked list.  */
   bitmap_element *current;     /* Last element looked at.  */
   unsigned int indx;           /* Index of last element looked at.  */
   bitmap_element *first;       /* First element in linked list.  */
   bitmap_element *current;     /* Last element looked at.  */
   unsigned int indx;           /* Index of last element looked at.  */

-  int using_obstack;           /* Are we using an obstack or ggc for
-                                   allocation?  */
+  bitmap_obstack *obstack;     /* Obstack to allocate elements from.
+                                  If NULL, then use ggc_alloc.  */

 } bitmap_head;
 } bitmap_head;

-typedef struct bitmap_head_def *bitmap;

 
 

-/* Enumeration giving the various operations we support.  */
-enum bitmap_bits {
-  BITMAP_AND,                  /* TO = FROM1 & FROM2 */
-  BITMAP_AND_COMPL,            /* TO = FROM1 & ~ FROM2 */
-  BITMAP_IOR,                  /* TO = FROM1 | FROM2 */
-  BITMAP_XOR,                  /* TO = FROM1 ^ FROM2 */
-  BITMAP_IOR_COMPL                     /* TO = FROM1 | ~FROM2 */
-};
+
+typedef struct bitmap_head_def *bitmap;

 
 /* Global data */
 extern bitmap_element bitmap_zero_bits;        /* Zero bitmap element */
 
 /* Global data */
 extern bitmap_element bitmap_zero_bits;        /* Zero bitmap element */

+extern bitmap_obstack bitmap_default_obstack;   /* Default bitmap obstack */

 
 /* Clear a bitmap by freeing up the linked list.  */
 extern void bitmap_clear (bitmap);
 
 /* Clear a bitmap by freeing up the linked list.  */
 extern void bitmap_clear (bitmap);


@@ -97,23 +102,23 @@ extern bool bitmap_intersect_compl_p (bitmap, bitmap);
 /* True if MAP is an empty bitmap.  */
 #define bitmap_empty_p(MAP) (!(MAP)->first)
 
 /* True if MAP is an empty bitmap.  */
 #define bitmap_empty_p(MAP) (!(MAP)->first)
 

-/* Perform an operation on two bitmaps, yielding a third.  */
-extern int bitmap_operation (bitmap, bitmap, bitmap, enum bitmap_bits);
-
-#define bitmap_and(DST,A,B) (void)bitmap_operation (DST,A,B,BITMAP_AND)
-#define bitmap_and_into(DST_SRC,B) (void)bitmap_operation (DST_SRC,DST_SRC,B,BITMAP_AND)
-#define bitmap_and_compl(DST,A,B) (void)bitmap_operation (DST,A,B,BITMAP_AND_COMPL)
-#define bitmap_and_compl_into(DST_SRC,B) (void)bitmap_operation (DST_SRC,DST_SRC,B,BITMAP_AND_COMPL)
-#define bitmap_ior(DST,A,B) (void)bitmap_operation (DST,A,B,BITMAP_IOR)
-#define bitmap_ior_into(DST_SRC,B) (void)bitmap_operation (DST_SRC,DST_SRC,B,BITMAP_IOR)
-#define bitmap_ior_compl(DST,A,B) (void)bitmap_operation (DST,A,Br,BITMAP_IOR_COMPL)
-#define bitmap_xor(DST,A,B) (void)bitmap_operation (DST,A,B,BITMAP_XOR)
-#define bitmap_xor_into(DST_SRC,B) (void)bitmap_operation (DST_SRC,DST_SRC,B,BITMAP_XOR)
-
-/* `or' into one bitmap the `and' of a second bitmap witih the complement
-   of a third. Return nonzero if the bitmap changes. */
-extern bool bitmap_ior_and_compl_into (bitmap, bitmap, bitmap);
-extern bool bitmap_ior_and_compl (bitmap, bitmap, bitmap, bitmap);
+/* Boolean operations on bitmaps.  The _into variants are two operand
+   versions that modify the first source operand.  The other variants
+   are three operand versions that to not destroy the source bitmaps.
+   The operations supported are &, & ~, |, ^.  */
+extern void bitmap_and (bitmap, bitmap, bitmap);
+extern void bitmap_and_into (bitmap, bitmap);
+extern void bitmap_and_compl (bitmap, bitmap, bitmap);
+extern bool bitmap_and_compl_into (bitmap, bitmap);
+extern bool bitmap_ior (bitmap, bitmap, bitmap);
+extern bool bitmap_ior_into (bitmap, bitmap);
+extern void bitmap_xor (bitmap, bitmap, bitmap);
+extern void bitmap_xor_into (bitmap, bitmap);
+
+/* DST = A | (B & ~C).  Return true if DST changes.  */
+extern bool bitmap_ior_and_compl (bitmap DST, bitmap A, bitmap B, bitmap C);
+/* A |= (B & ~C).  Return true if A changes.  */
+extern bool bitmap_ior_and_compl_into (bitmap DST, bitmap B, bitmap C);

 
 /* Clear a single register in a register set.  */
 extern void bitmap_clear_bit (bitmap, int);
 
 /* Clear a single register in a register set.  */
 extern void bitmap_clear_bit (bitmap, int);


@@ -131,476 +136,425 @@ extern void debug_bitmap_file (FILE *, bitmap);
 /* Print a bitmap.  */
 extern void bitmap_print (FILE *, bitmap, const char *, const char *);
 
 /* Print a bitmap.  */
 extern void bitmap_print (FILE *, bitmap, const char *, const char *);
 

-/* Initialize a bitmap header.  If HEAD is NULL, a new header will be
-   allocated.  USING_OBSTACK indicates how elements should be allocated.  */
-extern bitmap bitmap_initialize (bitmap head, int using_obstack);
+/* Initialize and release a bitmap obstack.  */
+extern void bitmap_obstack_initialize (bitmap_obstack *);
+extern void bitmap_obstack_release (bitmap_obstack *);

 
 

-/* Release all memory used by the bitmap obstack.  */
-extern void bitmap_release_memory (void);
+/* Initialize a bitmap header.  OBSTACK indicates the bitmap obstack
+   to allocate from, NULL for GC'd bitmap.  */
+
+static inline void
+bitmap_initialize (bitmap head, bitmap_obstack *obstack)
+{
+  head->first = head->current = NULL;
+  head->obstack = obstack;
+}
+
+/* Allocate and free bitmaps from obstack, malloc and gc'd memory.  */
+extern bitmap bitmap_obstack_alloc (bitmap_obstack *obstack);
+extern bitmap bitmap_gc_alloc (void);
+extern void bitmap_obstack_free (bitmap);

 
 /* A few compatibility/functions macros for compatibility with sbitmaps */
 #define dump_bitmap(file, bitmap) bitmap_print (file, bitmap, "", "\n")
 #define bitmap_zero(a) bitmap_clear (a)
 
 /* A few compatibility/functions macros for compatibility with sbitmaps */
 #define dump_bitmap(file, bitmap) bitmap_print (file, bitmap, "", "\n")
 #define bitmap_zero(a) bitmap_clear (a)

-#define bitmap_a_or_b(a,b,c) bitmap_operation (a, b, c, BITMAP_IOR)
-#define bitmap_a_and_b(a,b,c) bitmap_operation (a, b, c, BITMAP_AND)
-extern int bitmap_first_set_bit (bitmap);
-extern int bitmap_last_set_bit (bitmap);
+extern unsigned bitmap_first_set_bit (bitmap);

 
 

-/* Allocate a bitmap with oballoc.  */
-#define BITMAP_OBSTACK_ALLOC(OBSTACK)                          \
-  bitmap_initialize (obstack_alloc (OBSTACK, sizeof (bitmap_head)), 1)
+/* Allocate a bitmap from a bit obstack.  */
+#define BITMAP_ALLOC(OBSTACK) bitmap_obstack_alloc (OBSTACK)

 
 

-/* Allocate a bitmap with ggc_alloc.  */
-#define BITMAP_GGC_ALLOC()                     \
-  bitmap_initialize (NULL, 0)
-
-/* Allocate a bitmap with xmalloc.  */
-#define BITMAP_XMALLOC()                                        \
-  bitmap_initialize (xmalloc (sizeof (bitmap_head)), 1)
+/* Allocate a gc'd bitmap.  */
+#define BITMAP_GGC_ALLOC() bitmap_gc_alloc ()

 
 /* Do any cleanup needed on a bitmap when it is no longer used.  */
 #define BITMAP_FREE(BITMAP)                    \
 
 /* Do any cleanup needed on a bitmap when it is no longer used.  */
 #define BITMAP_FREE(BITMAP)                    \

-do {                                           \
-  if (BITMAP)                                  \
-    {                                          \
-      bitmap_clear (BITMAP);                   \
-      (BITMAP) = 0;                            \
-    }                                          \
-} while (0)
-
-/* Do any cleanup needed on an xmalloced bitmap when it is no longer used.  */
-#define BITMAP_XFREE(BITMAP)                   \
-do {                                           \
-  if (BITMAP)                                  \
-    {                                          \
-      bitmap_clear (BITMAP);                   \
-      free (BITMAP);                           \
-      (BITMAP) = 0;                            \
-    }                                          \
-} while (0)
-
-/* Do any one-time initializations needed for bitmaps.  */
-#define BITMAP_INIT_ONCE()
+       ((void)(bitmap_obstack_free (BITMAP), (BITMAP) = NULL))

 
 /* Iterator for bitmaps.  */
 
 typedef struct
 {
 
 /* Iterator for bitmaps.  */
 
 typedef struct
 {

-  /* Actual elements in the bitmaps.  */
-  bitmap_element *ptr1, *ptr2;
-
-  /* Position of an actual word in the elements.  */
-  unsigned word;
-
-  /* Position of a bit corresponding to the start of word.  */
-  unsigned word_bit;
-
-  /* Position of the actual bit.  */
-  unsigned bit;
-
+  /* Pointer to the current bitmap element.  */
+  bitmap_element *elt1;
+  
+  /* Pointer to 2nd bitmap element when two are involved.  */
+  bitmap_element *elt2;
+
+  /* Word within the current element.  */
+  unsigned word_no;
+  

   /* Contents of the actually processed word.  When finding next bit
      it is shifted right, so that the actual bit is always the least
      significant bit of ACTUAL.  */
   /* Contents of the actually processed word.  When finding next bit
      it is shifted right, so that the actual bit is always the least
      significant bit of ACTUAL.  */

-  BITMAP_WORD actual;
+  BITMAP_WORD bits;

 } bitmap_iterator;
 
 } bitmap_iterator;
 

-/* Moves the iterator BI to the first set bit on or after the current
-   position in bitmap and returns the bit if available.  The bit is
-   found in ACTUAL field only.  */
+/* Initialize a single bitmap iterator.  START_BIT is the first bit to
+   iterate from.  */

 
 

-static inline unsigned
-bmp_iter_common_next_1 (bitmap_iterator *bi)
+static inline void
+bmp_iter_set_init (bitmap_iterator *bi, bitmap map,
+                  unsigned start_bit, unsigned *bit_no)

 {
 {

-  while (!(bi->actual & 1))
+  bi->elt1 = map->first;
+  bi->elt2 = NULL;
+
+  /* Advance elt1 until it is not before the block containing start_bit.  */
+  while (1)

     {
     {

-      bi->actual >>= 1;
-      bi->bit++;
+      if (!bi->elt1)
+       {
+         bi->elt1 = &bitmap_zero_bits;
+         break;
+       }
+      
+      if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
+       break;
+      bi->elt1 = bi->elt1->next;

     }
 
     }
 

-  return bi->bit;
+  /* We might have gone past the start bit, so reinitialize it.  */
+  if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
+    start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
+  
+  /* Initialize for what is now start_bit.  */
+  bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
+  bi->bits = bi->elt1->bits[bi->word_no];
+  bi->bits >>= start_bit % BITMAP_WORD_BITS;
+
+  /* If this word is zero, we must make sure we're not pointing at the
+     first bit, otherwise our incrementing to the next word boundary
+     will fail.  It won't matter if this increment moves us into the
+     next word.  */
+  start_bit += !bi->bits;
+  
+  *bit_no = start_bit;

 }
 
 }
 

-/* Moves the iterator BI to the first set bit on or after the current
-   position in bitmap and returns the bit if available.  */
+/* Initialize an iterator to iterate over the intersection of two
+   bitmaps.  START_BIT is the bit to commence from.  */

 
 

-static inline unsigned
-bmp_iter_single_next_1 (bitmap_iterator *bi)
+static inline void
+bmp_iter_and_init (bitmap_iterator *bi, bitmap map1, bitmap map2,
+                  unsigned start_bit, unsigned *bit_no)

 {
 {

-  if (bi->actual)
-    return bmp_iter_common_next_1 (bi);
-
-  bi->word++;
-  bi->word_bit += BITMAP_WORD_BITS;
+  bi->elt1 = map1->first;
+  bi->elt2 = map2->first;

 
 

+  /* Advance elt1 until it is not before the block containing
+     start_bit.  */

   while (1)
     {
   while (1)
     {

-      for (;
-          bi->word < BITMAP_ELEMENT_WORDS;
-          bi->word++, bi->word_bit += BITMAP_WORD_BITS)
+      if (!bi->elt1)

        {
        {

-         bi->actual = bi->ptr1->bits[bi->word];
-         if (bi->actual)
-           {
-             bi->bit = bi->word_bit;
-             return bmp_iter_common_next_1 (bi);
-           }
+         bi->elt2 = NULL;
+         break;

        }
        }

-
-      bi->ptr1 = bi->ptr1->next;
-      if (!bi->ptr1)
-       return 0;
-
-      bi->word = 0;
-      bi->word_bit = bi->ptr1->indx * BITMAP_ELEMENT_ALL_BITS;
+      
+      if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
+       break;
+      bi->elt1 = bi->elt1->next;

     }
     }

-}
-
-/* Initializes a bitmap iterator BI for looping over bits of bitmap
-   BMP, starting with bit MIN.  Returns the first bit of BMP greater
-   or equal to MIN if there is any.  */
-
-static inline unsigned
-bmp_iter_single_init (bitmap_iterator *bi, bitmap bmp, unsigned min)
-{
-  unsigned indx = min / BITMAP_ELEMENT_ALL_BITS;
-
-  for (bi->ptr1 = bmp->first;
-       bi->ptr1 && bi->ptr1->indx < indx;
-       bi->ptr1 = bi->ptr1->next)
-    continue;
-
-  if (!bi->ptr1)
+  
+  /* Advance elt2 until it is not before elt1.  */
+  while (1)

     {
     {

-      /* To avoid warnings.  */
-      bi->word = 0;
-      bi->bit = 0;
-      bi->word_bit = 0;
-      bi->actual = 0;
-      bi->ptr2 = NULL;
-      return 0;
+      if (!bi->elt2)
+       {
+         bi->elt1 = bi->elt2 = &bitmap_zero_bits;
+         break;
+       }
+      
+      if (bi->elt2->indx >= bi->elt1->indx)
+       break;
+      bi->elt2 = bi->elt2->next;

     }
 
     }
 

-  if (bi->ptr1->indx == indx)
+  /* If we're at the same index, then we have some intersecting bits.  */
+  if (bi->elt1->indx == bi->elt2->indx)

     {
     {

-      unsigned bit_in_elt = min - BITMAP_ELEMENT_ALL_BITS * indx;
-      unsigned word_in_elt = bit_in_elt / BITMAP_WORD_BITS;
-      unsigned bit_in_word = bit_in_elt % BITMAP_WORD_BITS;
-
-      bi->word = word_in_elt;
-      bi->word_bit = min - bit_in_word;
-      bi->bit = min;
-      bi->actual = bi->ptr1->bits[word_in_elt] >> bit_in_word;
+      /* We might have advanced beyond the start_bit, so reinitialize
+        for that.  */
+      if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
+       start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
+      
+      bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
+      bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
+      bi->bits >>= start_bit % BITMAP_WORD_BITS;

     }
   else
     {
     }
   else
     {

-      bi->word = 0;
-      bi->bit = bi->ptr1->indx * BITMAP_ELEMENT_ALL_BITS;
-      bi->word_bit = bi->bit;
-      bi->actual = bi->ptr1->bits[0];
+      /* Otherwise we must immediately advance elt1, so initialize for
+        that.  */
+      bi->word_no = BITMAP_ELEMENT_WORDS - 1;
+      bi->bits = 0;

     }
     }

-
-  return bmp_iter_single_next_1 (bi);
+  
+  /* If this word is zero, we must make sure we're not pointing at the
+     first bit, otherwise our incrementing to the next word boundary
+     will fail.  It won't matter if this increment moves us into the
+     next word.  */
+  start_bit += !bi->bits;
+  
+  *bit_no = start_bit;

 }
 
 }
 

-/* Returns true if all elements of the bitmap referred to by iterator BI
-   were processed.  */
+/* Initialize an iterator to iterate over the bits in MAP1 & ~MAP2.
+   */

 
 

-static inline bool
-bmp_iter_end_p (const bitmap_iterator *bi)
+static inline void
+bmp_iter_and_compl_init (bitmap_iterator *bi, bitmap map1, bitmap map2,
+                        unsigned start_bit, unsigned *bit_no)

 {
 {

-  return bi->ptr1 == NULL;
-}
-
-/* Moves the iterator BI to the next bit of bitmap and returns the bit
-   if available.  */
-
-static inline unsigned
-bmp_iter_single_next (bitmap_iterator *bi)
-{
-  bi->bit++;
-  bi->actual >>= 1;
-  return bmp_iter_single_next_1 (bi);
-}
-
-/* Loop over all bits in BITMAP, starting with MIN and setting BITNUM to
-   the bit number.  ITER is a bitmap iterator.  */
-
-#define EXECUTE_IF_SET_IN_BITMAP(BITMAP, MIN, BITNUM, ITER)            \
-  for ((BITNUM) = bmp_iter_single_init (&(ITER), (BITMAP), (MIN));     \
-       !bmp_iter_end_p (&(ITER));                                      \
-       (BITNUM) = bmp_iter_single_next (&(ITER)))
-
-/* Moves the iterator BI to the first set bit on or after the current
-   position in difference of bitmaps and returns the bit if available.  */
-
-static inline unsigned
-bmp_iter_and_not_next_1 (bitmap_iterator *bi)
-{
-  if (bi->actual)
-    return bmp_iter_common_next_1 (bi);
-
-  bi->word++;
-  bi->word_bit += BITMAP_WORD_BITS;
+  bi->elt1 = map1->first;
+  bi->elt2 = map2->first;

 
 

+  /* Advance elt1 until it is not before the block containing start_bit.  */

   while (1)
     {
   while (1)
     {

-      bitmap_element *snd;
-
-      if (bi->ptr2 && bi->ptr2->indx == bi->ptr1->indx)
-       snd = bi->ptr2;
-      else
-       snd = &bitmap_zero_bits;
-
-      for (;
-          bi->word < BITMAP_ELEMENT_WORDS;
-          bi->word++, bi->word_bit += BITMAP_WORD_BITS)
+      if (!bi->elt1)

        {
        {

-         bi->actual = (bi->ptr1->bits[bi->word]
-                       & ~snd->bits[bi->word]);
-         if (bi->actual)
-           {
-             bi->bit = bi->word_bit;
-             return bmp_iter_common_next_1 (bi);
-           }
+         bi->elt1 = &bitmap_zero_bits;
+         break;

        }
        }

-
-      bi->ptr1 = bi->ptr1->next;
-      if (!bi->ptr1)
-       return 0;
-
-      while (bi->ptr2
-            && bi->ptr2->indx < bi->ptr1->indx)
-       bi->ptr2 = bi->ptr2->next;
-
-      bi->word = 0;
-      bi->word_bit = bi->ptr1->indx * BITMAP_ELEMENT_ALL_BITS;
+      
+      if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
+       break;
+      bi->elt1 = bi->elt1->next;

     }
     }

+
+  /* Advance elt2 until it is not before elt1.  */
+  while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
+    bi->elt2 = bi->elt2->next;
+
+  /* We might have advanced beyond the start_bit, so reinitialize for
+     that.  */
+  if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
+    start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
+  
+  bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
+  bi->bits = bi->elt1->bits[bi->word_no];
+  if (bi->elt2 && bi->elt1->indx == bi->elt2->indx)
+    bi->bits &= ~bi->elt2->bits[bi->word_no];
+  bi->bits >>= start_bit % BITMAP_WORD_BITS;
+  
+  /* If this word is zero, we must make sure we're not pointing at the
+     first bit, otherwise our incrementing to the next word boundary
+     will fail.  It won't matter if this increment moves us into the
+     next word.  */
+  start_bit += !bi->bits;
+  
+  *bit_no = start_bit;

 }
 
 }
 

-/* Initializes a bitmap iterator BI for looping over bits of bitmap
-   BMP1 &~ BMP2, starting with bit MIN.  Returns the first bit of
-   BMP1 &~ BMP2 greater or equal to MIN if there is any.  */
+/* Advance to the next bit in BI.  We don't advance to the next
+   nonzero bit yet.  */

 
 

-static inline unsigned
-bmp_iter_and_not_init (bitmap_iterator *bi, bitmap bmp1, bitmap bmp2,
-                      unsigned min)
+static inline void
+bmp_iter_next (bitmap_iterator *bi, unsigned *bit_no)

 {
 {

-  unsigned indx = min / BITMAP_ELEMENT_ALL_BITS;
+  bi->bits >>= 1;
+  *bit_no += 1;
+}

 
 

-  for (bi->ptr1 = bmp1->first;
-       bi->ptr1 && bi->ptr1->indx < indx;
-       bi->ptr1 = bi->ptr1->next)
-    continue;
+/* Advance to the next nonzero bit of a single bitmap, we will have
+   already advanced past the just iterated bit.  Return true if there
+   is a bit to iterate.  */

 
 

-  if (!bi->ptr1)
+static inline bool
+bmp_iter_set (bitmap_iterator *bi, unsigned *bit_no)
+{
+  /* If our current word is nonzero, it contains the bit we want.  */
+  if (bi->bits)

     {
     {

-      /* To avoid warnings.  */
-      bi->word = 0;
-      bi->bit = 0;
-      bi->word_bit = 0;
-      bi->actual = 0;
-      bi->ptr2 = NULL;
-      return 0;
+    next_bit:
+      while (!(bi->bits & 1))
+       {
+         bi->bits >>= 1;
+         *bit_no += 1;
+       }
+      return true;

     }
 
     }
 

-  for (bi->ptr2 = bmp2->first;
-       bi->ptr2 && bi->ptr2->indx < bi->ptr1->indx;
-       bi->ptr2 = bi->ptr2->next)
-    continue;
+  /* Round up to the word boundary.  We might have just iterated past
+     the end of the last word, hence the -1.  It is not possible for
+     bit_no to point at the beginning of the now last word.  */
+  *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
+            / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
+  bi->word_no++;

 
 

-  if (bi->ptr1->indx == indx)
-    {
-      unsigned bit_in_elt = min - BITMAP_ELEMENT_ALL_BITS * indx;
-      unsigned word_in_elt = bit_in_elt / BITMAP_WORD_BITS;
-      unsigned bit_in_word = bit_in_elt % BITMAP_WORD_BITS;
-
-      bi->word = word_in_elt;
-      bi->word_bit = min - bit_in_word;
-      bi->bit = min;
-
-      if (bi->ptr2 && bi->ptr2->indx == indx)
-       bi->actual = (bi->ptr1->bits[word_in_elt]
-                     & ~bi->ptr2->bits[word_in_elt]) >> bit_in_word;
-      else
-       bi->actual = bi->ptr1->bits[word_in_elt] >> bit_in_word;
-    }
-  else
+  while (1)

     {
     {

-      bi->word = 0;
-      bi->bit = bi->ptr1->indx * BITMAP_ELEMENT_ALL_BITS;
-      bi->word_bit = bi->bit;
-
-      if (bi->ptr2 && bi->ptr2->indx == bi->ptr1->indx)
-       bi->actual = (bi->ptr1->bits[0] & ~bi->ptr2->bits[0]);
-      else
-       bi->actual = bi->ptr1->bits[0];
+      /* Find the next nonzero word in this elt.  */
+      while (bi->word_no != BITMAP_ELEMENT_WORDS)
+       {
+         bi->bits = bi->elt1->bits[bi->word_no];
+         if (bi->bits)
+           goto next_bit;
+         *bit_no += BITMAP_WORD_BITS;
+         bi->word_no++;
+       }
+  
+      /* Advance to the next element.  */
+      bi->elt1 = bi->elt1->next;
+      if (!bi->elt1)
+       return false;
+      *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
+      bi->word_no = 0;

     }
     }

-
-  return bmp_iter_and_not_next_1 (bi);

 }
 
 }
 

-/* Moves the iterator BI to the next bit of difference of bitmaps and returns
-   the bit if available.  */
+/* Advance to the next nonzero bit of an intersecting pair of
+   bitmaps.  We will have already advanced past the just iterated bit.
+   Return true if there is a bit to iterate.  */

 
 

-static inline unsigned
-bmp_iter_and_not_next (bitmap_iterator *bi)
-{
-  bi->bit++;
-  bi->actual >>= 1;
-  return bmp_iter_and_not_next_1 (bi);
-}
-
-/* Loop over all bits in BMP1 and BMP2, starting with MIN, setting
-   BITNUM to the bit number for all bits that are set in the first bitmap
-   and not set in the second.  ITER is a bitmap iterator.  */
-
-#define EXECUTE_IF_AND_COMPL_IN_BITMAP(BMP1, BMP2, MIN, BITNUM, ITER)  \
-  for ((BITNUM) = bmp_iter_and_not_init (&(ITER), (BMP1), (BMP2), (MIN)); \
-       !bmp_iter_end_p (&(ITER));                                              \
-       (BITNUM) = bmp_iter_and_not_next (&(ITER)))
-
-/* Moves the iterator BI to the first set bit on or after the current
-   position in intersection of bitmaps and returns the bit if available.  */
-
-static inline unsigned
-bmp_iter_and_next_1 (bitmap_iterator *bi)
+static inline bool
+bmp_iter_and (bitmap_iterator *bi, unsigned *bit_no)

 {
 {

-  if (bi->actual)
-    return bmp_iter_common_next_1 (bi);
-
-  bi->word++;
-  bi->word_bit += BITMAP_WORD_BITS;
+  /* If our current word is nonzero, it contains the bit we want.  */
+  if (bi->bits)
+    {
+    next_bit:
+      while (!(bi->bits & 1))
+       {
+         bi->bits >>= 1;
+         *bit_no += 1;
+       }
+      return true;
+    }

 
 

+  /* Round up to the word boundary.  We might have just iterated past
+     the end of the last word, hence the -1.  It is not possible for
+     bit_no to point at the beginning of the now last word.  */
+  *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
+            / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
+  bi->word_no++;
+  

   while (1)
     {
   while (1)
     {

-      for (;
-          bi->word < BITMAP_ELEMENT_WORDS;
-          bi->word++, bi->word_bit += BITMAP_WORD_BITS)
+      /* Find the next nonzero word in this elt.  */
+      while (bi->word_no != BITMAP_ELEMENT_WORDS)

        {
        {

-         bi->actual = (bi->ptr1->bits[bi->word]
-                       & bi->ptr2->bits[bi->word]);
-         if (bi->actual)
-           {
-             bi->bit = bi->word_bit;
-             return bmp_iter_common_next_1 (bi);
-           }
+         bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
+         if (bi->bits)
+           goto next_bit;
+         *bit_no += BITMAP_WORD_BITS;
+         bi->word_no++;

        }
        }

-
+  
+      /* Advance to the next identical element.  */

       do
        {
       do
        {

-         bi->ptr1 = bi->ptr1->next;
-         if (!bi->ptr1)
-           return 0;
-
-         while (bi->ptr2->indx < bi->ptr1->indx)
+         /* Advance elt1 while it is less than elt2.  We always want
+            to advance one elt.  */
+         do
+           {
+             bi->elt1 = bi->elt1->next;
+             if (!bi->elt1)
+               return false;
+           }
+         while (bi->elt1->indx < bi->elt2->indx);
+       
+         /* Advance elt2 to be no less than elt1.  This might not
+            advance.  */
+         while (bi->elt2->indx < bi->elt1->indx)

            {
            {

-             bi->ptr2 = bi->ptr2->next;
-             if (!bi->ptr2)
-               {
-                 bi->ptr1 = NULL;
-                 return 0;
-               }
+             bi->elt2 = bi->elt2->next;
+             if (!bi->elt2)
+               return false;

            }
        }
            }
        }

-      while (bi->ptr1->indx != bi->ptr2->indx);
-
-      bi->word = 0;
-      bi->word_bit = bi->ptr1->indx * BITMAP_ELEMENT_ALL_BITS;
+      while (bi->elt1->indx != bi->elt2->indx);
+  
+      *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
+      bi->word_no = 0;

     }
 }
 
     }
 }
 

-/* Initializes a bitmap iterator BI for looping over bits of bitmap
-   BMP1 & BMP2, starting with bit MIN.  Returns the first bit of
-   BMP1 & BMP2 greater or equal to MIN if there is any.  */
+/* Advance to the next nonzero bit in the intersection of
+   complemented bitmaps.  We will have already advanced past the just
+   iterated bit.  */

 
 

-static inline unsigned
-bmp_iter_and_init (bitmap_iterator *bi, bitmap bmp1, bitmap bmp2,
-                      unsigned min)
+static inline bool
+bmp_iter_and_compl (bitmap_iterator *bi, unsigned *bit_no)

 {
 {

-  unsigned indx = min / BITMAP_ELEMENT_ALL_BITS;
-
-  for (bi->ptr1 = bmp1->first;
-       bi->ptr1 && bi->ptr1->indx < indx;
-       bi->ptr1 = bi->ptr1->next)
-    continue;
-
-  if (!bi->ptr1)
-    goto empty;
-
-  bi->ptr2 = bmp2->first;
-  if (!bi->ptr2)
-    goto empty;
-
-  while (1)
+  /* If our current word is nonzero, it contains the bit we want.  */
+  if (bi->bits)

     {
     {

-      while (bi->ptr2->indx < bi->ptr1->indx)
+    next_bit:
+      while (!(bi->bits & 1))

        {
        {

-         bi->ptr2 = bi->ptr2->next;
-         if (!bi->ptr2)
-           goto empty;
+         bi->bits >>= 1;
+         *bit_no += 1;

        }
        }

-
-      if (bi->ptr1->indx == bi->ptr2->indx)
-       break;
-
-      bi->ptr1 = bi->ptr1->next;
-      if (!bi->ptr1)
-       goto empty;
+      return true;

     }
 
     }
 

-  if (bi->ptr1->indx == indx)
-    {
-      unsigned bit_in_elt = min - BITMAP_ELEMENT_ALL_BITS * indx;
-      unsigned word_in_elt = bit_in_elt / BITMAP_WORD_BITS;
-      unsigned bit_in_word = bit_in_elt % BITMAP_WORD_BITS;
-
-      bi->word = word_in_elt;
-      bi->word_bit = min - bit_in_word;
-      bi->bit = min;
+  /* Round up to the word boundary.  We might have just iterated past
+     the end of the last word, hence the -1.  It is not possible for
+     bit_no to point at the beginning of the now last word.  */
+  *bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
+            / BITMAP_WORD_BITS * BITMAP_WORD_BITS);
+  bi->word_no++;

 
 

-      bi->actual = (bi->ptr1->bits[word_in_elt]
-                   & bi->ptr2->bits[word_in_elt]) >> bit_in_word;
-    }
-  else
+  while (1)

     {
     {

-      bi->word = 0;
-      bi->bit = bi->ptr1->indx * BITMAP_ELEMENT_ALL_BITS;
-      bi->word_bit = bi->bit;
-
-      bi->actual = (bi->ptr1->bits[0] & bi->ptr2->bits[0]);
+      /* Find the next nonzero word in this elt.  */
+      while (bi->word_no != BITMAP_ELEMENT_WORDS)
+       {
+         bi->bits = bi->elt1->bits[bi->word_no];
+         if (bi->elt2 && bi->elt2->indx == bi->elt1->indx)
+           bi->bits &= ~bi->elt2->bits[bi->word_no];
+         if (bi->bits)
+           goto next_bit;
+         *bit_no += BITMAP_WORD_BITS;
+         bi->word_no++;
+       }
+  
+      /* Advance to the next element of elt1.  */
+      bi->elt1 = bi->elt1->next;
+      if (!bi->elt1)
+       return false;
+
+      /* Advance elt2 until it is no less than elt1.  */
+      while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
+       bi->elt2 = bi->elt2->next;
+      
+      *bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
+      bi->word_no = 0;

     }
     }

-
-  return bmp_iter_and_next_1 (bi);
-
-empty:
-  /* To avoid warnings.  */
-  bi->word = 0;
-  bi->bit = 0;
-  bi->word_bit = 0;
-  bi->actual = 0;
-  bi->ptr1 = NULL;
-  bi->ptr2 = NULL;
-  return 0;

 }
 
 }
 

-/* Moves the iterator BI to the next bit of intersection of bitmaps and returns
-   the bit if available.  */
+/* Loop over all bits set in BITMAP, starting with MIN and setting
+   BITNUM to the bit number.  ITER is a bitmap iterator.  BITNUM
+   should be treated as a read-only variable as it contains loop
+   state.  */

 
 

-static inline unsigned
-bmp_iter_and_next (bitmap_iterator *bi)
-{
-  bi->bit++;
-  bi->actual >>= 1;
-  return bmp_iter_and_next_1 (bi);
-}
-
-/* Loop over all bits in BMP1 and BMP2, starting with MIN, setting
-   BITNUM to the bit number for all bits that are set in both bitmaps.
-   ITER is a bitmap iterator.  */
-
-#define EXECUTE_IF_AND_IN_BITMAP(BMP1, BMP2, MIN, BITNUM, ITER)                \
-  for ((BITNUM) = bmp_iter_and_init (&(ITER), (BMP1), (BMP2), (MIN));  \
-       !bmp_iter_end_p (&(ITER));                                              \
-       (BITNUM) = bmp_iter_and_next (&(ITER)))
+#define EXECUTE_IF_SET_IN_BITMAP(BITMAP, MIN, BITNUM, ITER)            \
+  for (bmp_iter_set_init (&(ITER), (BITMAP), (MIN), &(BITNUM));                \
+       bmp_iter_set (&(ITER), &(BITNUM));                              \
+       bmp_iter_next (&(ITER), &(BITNUM)))
+
+/* Loop over all the bits set in BITMAP1 & BITMAP2, starting with MIN
+   and setting BITNUM to the bit number.  ITER is a bitmap iterator.
+   BITNUM should be treated as a read-only variable as it contains
+   loop state.  */
+
+#define EXECUTE_IF_AND_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER)  \
+  for (bmp_iter_and_init (&(ITER), (BITMAP1), (BITMAP2), (MIN),        \
+                         &(BITNUM));                                   \
+       bmp_iter_and (&(ITER), &(BITNUM));                              \
+       bmp_iter_next (&(ITER), &(BITNUM)))
+
+/* Loop over all the bits set in BITMAP1 & ~BITMAP2, starting with MIN
+   and setting BITNUM to the bit number.  ITER is a bitmap iterator.
+   BITNUM should be treated as a read-only variable as it contains
+   loop state.  */
+
+#define EXECUTE_IF_AND_COMPL_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER) \
+  for (bmp_iter_and_compl_init (&(ITER), (BITMAP1), (BITMAP2), (MIN),  \
+                               &(BITNUM));                             \
+       bmp_iter_and_compl (&(ITER), &(BITNUM));                                \
+       bmp_iter_next (&(ITER), &(BITNUM)))

 
 #endif /* GCC_BITMAP_H */
 
 #endif /* GCC_BITMAP_H */