diff options
Diffstat (limited to 'src/libcore/num/flt2dec')
| -rw-r--r-- | src/libcore/num/flt2dec/bignum.rs | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/src/libcore/num/flt2dec/bignum.rs b/src/libcore/num/flt2dec/bignum.rs index 15980f925fa..ee1f6ffdd0a 100644 --- a/src/libcore/num/flt2dec/bignum.rs +++ b/src/libcore/num/flt2dec/bignum.rs @@ -171,20 +171,19 @@ macro_rules! define_bignum { pub fn bit_length(&self) -> usize { use mem; - let digitbits = mem::size_of::<$ty>()* 8; // Skip over the most significant digits which are zero. - let nonzero = match self.digits().iter().rposition(|&x| x != 0) { - Some(n) => { - let end = self.size - n; - &self.digits()[..end] - } - None => { - // There are no non-zero digits, i.e. the number is zero. - return 0; - } - }; + let digits = self.digits(); + let zeros = digits.iter().rev().take_while(|&&x| x == 0).count(); + let end = digits.len() - zeros; + let nonzero = &digits[..end]; + + if nonzero.is_empty() { + // There are no non-zero digits, i.e. the number is zero. + return 0; + } // This could be optimized with leading_zeros() and bit shifts, but that's // probably not worth the hassle. + let digitbits = mem::size_of::<$ty>()* 8; let mut i = nonzero.len() * digitbits - 1; while self.get_bit(i) == 0 { i -= 1; |