diff options
| -rw-r--r-- | library/core/src/num/f16.rs | 84 |
1 files changed, 83 insertions, 1 deletions
diff --git a/library/core/src/num/f16.rs b/library/core/src/num/f16.rs index 039f5188ba4..71cb0a8198a 100644 --- a/library/core/src/num/f16.rs +++ b/library/core/src/num/f16.rs @@ -19,9 +19,91 @@ pub mod consts {} #[cfg(not(test))] impl f16 { - // FIXME(f16_f128): almost everything in this `impl` is missing examples and a const + // FIXME(f16_f128): almost all methods in this `impl` are missing examples and a const // implementation. Add these once we can run code on all platforms and have f16/f128 in CTFE. + /// The radix or base of the internal representation of `f16`. + #[unstable(feature = "f16", issue = "116909")] + pub const RADIX: u32 = 2; + + /// Number of significant digits in base 2. + #[unstable(feature = "f16", issue = "116909")] + pub const MANTISSA_DIGITS: u32 = 11; + + /// Approximate number of significant digits in base 10. + /// + /// This is the maximum <i>x</i> such that any decimal number with <i>x</i> + /// significant digits can be converted to `f16` and back without loss. + /// + /// Equal to floor(log<sub>10</sub> 2<sup>[`MANTISSA_DIGITS`] − 1</sup>). + /// + /// [`MANTISSA_DIGITS`]: f16::MANTISSA_DIGITS + #[unstable(feature = "f16", issue = "116909")] + pub const DIGITS: u32 = 3; + + /// [Machine epsilon] value for `f16`. + /// + /// This is the difference between `1.0` and the next larger representable number. + /// + /// Equal to 2<sup>1 − [`MANTISSA_DIGITS`]</sup>. + /// + /// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon + /// [`MANTISSA_DIGITS`]: f16::MANTISSA_DIGITS + #[unstable(feature = "f16", issue = "116909")] + pub const EPSILON: f16 = 9.7656e-4_f16; + + /// Smallest finite `f16` value. + /// + /// Equal to −[`MAX`]. + /// + /// [`MAX`]: f16::MAX + #[unstable(feature = "f16", issue = "116909")] + pub const MIN: f16 = -6.5504e+4_f16; + /// Smallest positive normal `f16` value. + /// + /// Equal to 2<sup>[`MIN_EXP`] − 1</sup>. + /// + /// [`MIN_EXP`]: f16::MIN_EXP + #[unstable(feature = "f16", issue = "116909")] + pub const MIN_POSITIVE: f16 = 6.1035e-5_f16; + /// Largest finite `f16` value. + /// + /// Equal to + /// (1 − 2<sup>−[`MANTISSA_DIGITS`]</sup>) 2<sup>[`MAX_EXP`]</sup>. + /// + /// [`MANTISSA_DIGITS`]: f16::MANTISSA_DIGITS + /// [`MAX_EXP`]: f16::MAX_EXP + #[unstable(feature = "f16", issue = "116909")] + pub const MAX: f16 = 6.5504e+4_f16; + + /// One greater than the minimum possible normal power of 2 exponent. + /// + /// If <i>x</i> = `MIN_EXP`, then normal numbers + /// ≥ 0.5 × 2<sup><i>x</i></sup>. + #[unstable(feature = "f16", issue = "116909")] + pub const MIN_EXP: i32 = -13; + /// Maximum possible power of 2 exponent. + /// + /// If <i>x</i> = `MAX_EXP`, then normal numbers + /// < 1 × 2<sup><i>x</i></sup>. + #[unstable(feature = "f16", issue = "116909")] + pub const MAX_EXP: i32 = 16; + + /// Minimum <i>x</i> for which 10<sup><i>x</i></sup> is normal. + /// + /// Equal to ceil(log<sub>10</sub> [`MIN_POSITIVE`]). + /// + /// [`MIN_POSITIVE`]: f16::MIN_POSITIVE + #[unstable(feature = "f16", issue = "116909")] + pub const MIN_10_EXP: i32 = -4; + /// Maximum <i>x</i> for which 10<sup><i>x</i></sup> is normal. + /// + /// Equal to floor(log<sub>10</sub> [`MAX`]). + /// + /// [`MAX`]: f16::MAX + #[unstable(feature = "f16", issue = "116909")] + pub const MAX_10_EXP: i32 = 4; + /// Returns `true` if this value is NaN. #[inline] #[must_use] |