diff options
| -rw-r--r-- | net/ceph/crush/mapper.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/net/ceph/crush/mapper.c b/net/ceph/crush/mapper.c index 5fcfb98f309e..511ade95339a 100644 --- a/net/ceph/crush/mapper.c +++ b/net/ceph/crush/mapper.c @@ -253,9 +253,15 @@ static __u64 crush_ln(unsigned int xin) /* normalize input */ iexpon = 15; - while (!(x & 0x18000)) { - x <<= 1; - iexpon--; + + /* + * figure out number of bits we need to shift and + * do it in one step instead of iteratively + */ + if (!(x & 0x18000)) { + int bits = __builtin_clz(x & 0x1FFFF) - 16; + x <<= bits; + iexpon = 15 - bits; } index1 = (x >> 8) << 1; |