dist/gcc/bitmap.h

40      - the element for I will have index is I / (bits per element)
41      - the position for I within element is I % (bits per element)
45    An important parameter is the number of bits per element.  In this
46    implementation, there are 128 bits per element.  This results in a
287 /* Number of bits in each actual element of a bitmap.  */
298 /* Bitmap set element.  We use a linked list to hold only the bits that
320   BITMAP_WORD bits[BITMAP_ELEMENT_WORDS];
399 /* Count the number of bits set in the bitmap.  */
402 /* Count the number of unique bits set across the two bitmaps.  */
522   BITMAP_WORD bits;
557   bi->bits = bi->elt1->bits[bi->word_no];
558   bi->bits >>= start_bit % BITMAP_WORD_BITS;
564   start_bit += !bi->bits;
610   /* If we're at the same index, then we have some intersecting bits.  */
619       bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
620       bi->bits >>= start_bit % BITMAP_WORD_BITS;
627       bi->bits = 0;
634   start_bit += !bi->bits;
639 /* Initialize an iterator to iterate over the bits in MAP1 & ~MAP2.  */
675   bi->bits = bi->elt1->bits[bi->word_no];
677     bi->bits &= ~bi->elt2->bits[bi->word_no];
678   bi->bits >>= start_bit % BITMAP_WORD_BITS;
684   start_bit += !bi->bits;
695   bi->bits >>= 1;
706     unsigned int n = __builtin_ctzl (bi->bits);
708     bi->bits >>= n;
712   while (!(bi->bits & 1))
714       bi->bits >>= 1;
728   if (bi->bits)
747 	  bi->bits = bi->elt1->bits[bi->word_no];
748 	  if (bi->bits)
774   if (bi->bits)
793 	  bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
794 	  if (bi->bits)
843   if (bi->bits)
862 	  bi->bits = bi->elt1->bits[bi->word_no];
864 	    bi->bits &= ~bi->elt2->bits[bi->word_no];
865 	  if (bi->bits)
895        will not affect the set of bits you are visiting during the iteration;
897        whether that affects the set of bits you are visiting during the
903 /* Loop over all bits set in BITMAP, starting with MIN and setting
916 /* Loop over all the bits set in BITMAP1 & BITMAP2, starting with MIN
927 /* Loop over all the bits set in BITMAP1 & ~BITMAP2, starting with MIN
1046       /* Fill in the bits of the bitmap element.  */
1050 	     bitmap_element->bits.  */
1060 	      bitmap_element->bits[word_i] = word;
1066 	     bitmap_element->bits, or are an exact multiple of that size.  */
1071 	      bitmap_element->bits[word_i++]
1074 	    bitmap_element->bits[word_i++] = 0;