These functions could only work with 32-bit integers because of their special cases for an argument of value 0. However, none of the existing users depended on this special case, and some of the users did try to use these functions with 64-bit integer arguments. Thus, this commit changes them to support 64-bit integer arguments and drops the special cases for zero.
This fixes a latent bug that applied rightmost_1bit_idx() to an ofpact bitmap, which only becomes visible when an OFPACT_* with value greater than 32 is included in the bitmap. Reported-by: Kyle Upton <kup...@baymicrosystems.com> Reported-at: http://openvswitch.org/pipermail/dev/2015-September/060128.html Signed-off-by: Ben Pfaff <b...@nicira.com> --- lib/util.h | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) diff --git a/lib/util.h b/lib/util.h index 7080a0c..4186d49 100644 --- a/lib/util.h +++ b/lib/util.h @@ -506,25 +506,20 @@ zero_rightmost_1bit(uintmax_t x) return x & (x - 1); } -/* Returns the index of the rightmost 1-bit in 'x' (e.g. 01011000 => 3), or 32 - * if 'x' is 0. - * - * Unlike the other functions for rightmost 1-bits, this function only works - * with 32-bit integers. */ +/* Returns the index of the rightmost 1-bit in 'x' (e.g. 01011000 => 3), or an + * undefined value if 'x' is 0. */ static inline int -rightmost_1bit_idx(uint32_t x) +rightmost_1bit_idx(uint64_t x) { - return ctz32(x); + return ctz64(x); } -/* Returns the index of the leftmost 1-bit in 'x' (e.g. 01011000 => 6), or 32 - * if 'x' is 0. - * - * This function only works with 32-bit integers. */ +/* Returns the index of the leftmost 1-bit in 'x' (e.g. 01011000 => 6), or an + * undefined value if 'x' is 0. */ static inline uint32_t -leftmost_1bit_idx(uint32_t x) +leftmost_1bit_idx(uint64_t x) { - return x ? log_2_floor(x) : 32; + return log_2_floor(x); } /* Return a ovs_be32 prefix in network byte order with 'plen' highest bits set. -- 2.1.3 _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
