diff options
Diffstat (limited to 'gcc/bitmap.cc')
| -rw-r--r-- | gcc/bitmap.cc | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/gcc/bitmap.cc b/gcc/bitmap.cc index 20de562..d1d0324 100644 --- a/gcc/bitmap.cc +++ b/gcc/bitmap.cc @@ -1217,12 +1217,12 @@ bitmap_single_bit_set_p (const_bitmap a) /* Return the bit number of the first set bit in the bitmap. The - bitmap must be non-empty. */ + bitmap must be non-empty. When CLEAR is true it clears the bit. */ -unsigned -bitmap_first_set_bit (const_bitmap a) +static unsigned +bitmap_first_set_bit_worker (bitmap a, bool clear) { - const bitmap_element *elt = a->first; + bitmap_element *elt = a->first; unsigned bit_no; BITMAP_WORD word; unsigned ix; @@ -1269,6 +1269,21 @@ bitmap_first_set_bit (const_bitmap a) gcc_checking_assert (word & 1); #endif + + if (clear) + { + elt->bits[ix] &= ~((BITMAP_WORD) 1 << (bit_no % BITMAP_WORD_BITS)); + /* If we cleared the entire word, free up the element. */ + if (!elt->bits[ix] + && bitmap_element_zerop (elt)) + { + if (!a->tree_form) + bitmap_list_unlink_element (a, elt); + else + bitmap_tree_unlink_element (a, elt); + } + } + return bit_no; } @@ -1276,6 +1291,24 @@ bitmap_first_set_bit (const_bitmap a) bitmap must be non-empty. */ unsigned +bitmap_first_set_bit (const_bitmap a) +{ + return bitmap_first_set_bit_worker (const_cast<bitmap> (a), false); +} + +/* Return and clear the bit number of the first set bit in the bitmap. The + bitmap must be non-empty. */ + +unsigned +bitmap_clear_first_set_bit (bitmap a) +{ + return bitmap_first_set_bit_worker (a, true); +} + +/* Return the bit number of the first set bit in the bitmap. The + bitmap must be non-empty. */ + +unsigned bitmap_last_set_bit (const_bitmap a) { const bitmap_element *elt; |