diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libcore/num/mod.rs | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs index 8a32479b2ff..39e2c7ca60c 100644 --- a/src/libcore/num/mod.rs +++ b/src/libcore/num/mod.rs @@ -1416,18 +1416,14 @@ $EndFeature, " ```"), #[stable(feature = "no_panic_abs", since = "1.13.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[allow_internal_unstable(const_if_match)] #[inline] pub const fn wrapping_abs(self) -> Self { - // sign is -1 (all ones) for negative numbers, 0 otherwise. - let sign = self >> ($BITS - 1); - // For positive self, sign == 0 so the expression is simply - // (self ^ 0).wrapping_sub(0) == self == abs(self). - // - // For negative self, self ^ sign == self ^ all_ones. - // But all_ones ^ self == all_ones - self == -1 - self. - // So for negative numbers, (self ^ sign).wrapping_sub(sign) is - // (-1 - self).wrapping_sub(-1) == -self == abs(self). - (self ^ sign).wrapping_sub(sign) + if self.is_negative() { + self.wrapping_neg() + } else { + self + } } } |