This helper get the highest 1 bit position of the upper bound. If the range is empty or upper bound is zero, -1 is returned.
Suggested-by: Cédric Le Goater <c...@redhat.com> Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com> --- include/qemu/range.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/qemu/range.h b/include/qemu/range.h index 205e1da76d..8e05bc1d9f 100644 --- a/include/qemu/range.h +++ b/include/qemu/range.h @@ -20,6 +20,8 @@ #ifndef QEMU_RANGE_H #define QEMU_RANGE_H +#include "qemu/bitops.h" + /* * Operations on 64 bit address ranges. * Notes: @@ -217,6 +219,15 @@ static inline int ranges_overlap(uint64_t first1, uint64_t len1, return !(last2 < first1 || last1 < first2); } +/* Get highest non-zero bit position of a range */ +static inline int range_get_last_bit(Range *range) +{ + if (range_is_empty(range) || !range->upb) { + return -1; + } + return find_last_bit(&range->upb, sizeof(range->upb)); +} + /* * Return -1 if @a < @b, 1 @a > @b, and 0 if they touch or overlap. * Both @a and @b must not be empty. -- 2.34.1