Skip to content

Commit fc47cf3

Browse files
borsbors
committed
Auto merge of rust-lang#123850 - tspiteri:f16_f128_consts, r=Amanieu
Add constants for f16 and f128 - Commit 1 adds associated constants for `f16`, excluding NaN and infinities as these are implemented using arithmetic for `f32` and `f64`. - Commit 2 adds associated constants for `f128`, excluding NaN and infinities. - Commit 3 adds constants in `std::f16::consts`. - Commit 4 adds constants in `std::f128::consts`.
2 parents 25e3949 + d8e6b81 commit fc47cf3

File tree

5 files changed

+398
-4
lines changed

5 files changed

+398
-4
lines changed

‎library/core/src/num/f128.rs

+193-2
Original file line numberDiff line numberDiff line change
@@ -15,13 +15,204 @@ use crate::mem;
1515

1616
/// Basic mathematical constants.
1717
#[unstable(feature = "f128", issue = "116909")]
18-
pub mod consts {}
18+
pub mod consts {
19+
// FIXME: replace with mathematical constants from cmath.
20+
21+
/// Archimedes' constant (π)
22+
#[unstable(feature = "f128", issue = "116909")]
23+
pub const PI: f128 = 3.14159265358979323846264338327950288419716939937510582097494_f128;
24+
25+
/// The full circle constant (τ)
26+
///
27+
/// Equal to 2π.
28+
#[unstable(feature = "f128", issue = "116909")]
29+
pub const TAU: f128 = 6.28318530717958647692528676655900576839433879875021164194989_f128;
30+
31+
/// The golden ratio (φ)
32+
#[unstable(feature = "f128", issue = "116909")]
33+
// Also, #[unstable(feature = "more_float_constants", issue = "103883")]
34+
pub const PHI: f128 = 1.61803398874989484820458683436563811772030917980576286213545_f128;
35+
36+
/// The Euler-Mascheroni constant (γ)
37+
#[unstable(feature = "f128", issue = "116909")]
38+
// Also, #[unstable(feature = "more_float_constants", issue = "103883")]
39+
pub const EGAMMA: f128 = 0.577215664901532860606512090082402431042159335939923598805767_f128;
40+
41+
/// π/2
42+
#[unstable(feature = "f128", issue = "116909")]
43+
pub const FRAC_PI_2: f128 = 1.57079632679489661923132169163975144209858469968755291048747_f128;
44+
45+
/// π/3
46+
#[unstable(feature = "f128", issue = "116909")]
47+
pub const FRAC_PI_3: f128 = 1.04719755119659774615421446109316762806572313312503527365831_f128;
48+
49+
/// π/4
50+
#[unstable(feature = "f128", issue = "116909")]
51+
pub const FRAC_PI_4: f128 = 0.785398163397448309615660845819875721049292349843776455243736_f128;
52+
53+
/// π/6
54+
#[unstable(feature = "f128", issue = "116909")]
55+
pub const FRAC_PI_6: f128 = 0.523598775598298873077107230546583814032861566562517636829157_f128;
56+
57+
/// π/8
58+
#[unstable(feature = "f128", issue = "116909")]
59+
pub const FRAC_PI_8: f128 = 0.392699081698724154807830422909937860524646174921888227621868_f128;
60+
61+
/// 1/π
62+
#[unstable(feature = "f128", issue = "116909")]
63+
pub const FRAC_1_PI: f128 = 0.318309886183790671537767526745028724068919291480912897495335_f128;
64+
65+
/// 1/sqrt(π)
66+
#[unstable(feature = "f128", issue = "116909")]
67+
// Also, #[unstable(feature = "more_float_constants", issue = "103883")]
68+
pub const FRAC_1_SQRT_PI: f128 =
69+
0.564189583547756286948079451560772585844050629328998856844086_f128;
70+
71+
/// 2/π
72+
#[unstable(feature = "f128", issue = "116909")]
73+
pub const FRAC_2_PI: f128 = 0.636619772367581343075535053490057448137838582961825794990669_f128;
74+
75+
/// 2/sqrt(π)
76+
#[unstable(feature = "f128", issue = "116909")]
77+
pub const FRAC_2_SQRT_PI: f128 =
78+
1.12837916709551257389615890312154517168810125865799771368817_f128;
79+
80+
/// sqrt(2)
81+
#[unstable(feature = "f128", issue = "116909")]
82+
pub const SQRT_2: f128 = 1.41421356237309504880168872420969807856967187537694807317668_f128;
83+
84+
/// 1/sqrt(2)
85+
#[unstable(feature = "f128", issue = "116909")]
86+
pub const FRAC_1_SQRT_2: f128 =
87+
0.707106781186547524400844362104849039284835937688474036588340_f128;
88+
89+
/// sqrt(3)
90+
#[unstable(feature = "f128", issue = "116909")]
91+
// Also, #[unstable(feature = "more_float_constants", issue = "103883")]
92+
pub const SQRT_3: f128 = 1.73205080756887729352744634150587236694280525381038062805581_f128;
93+
94+
/// 1/sqrt(3)
95+
#[unstable(feature = "f128", issue = "116909")]
96+
// Also, #[unstable(feature = "more_float_constants", issue = "103883")]
97+
pub const FRAC_1_SQRT_3: f128 =
98+
0.577350269189625764509148780501957455647601751270126876018602_f128;
99+
100+
/// Euler's number (e)
101+
#[unstable(feature = "f128", issue = "116909")]
102+
pub const E: f128 = 2.71828182845904523536028747135266249775724709369995957496697_f128;
103+
104+
/// log<sub>2</sub>(10)
105+
#[unstable(feature = "f128", issue = "116909")]
106+
pub const LOG2_10: f128 = 3.32192809488736234787031942948939017586483139302458061205476_f128;
107+
108+
/// log<sub>2</sub>(e)
109+
#[unstable(feature = "f128", issue = "116909")]
110+
pub const LOG2_E: f128 = 1.44269504088896340735992468100189213742664595415298593413545_f128;
111+
112+
/// log<sub>10</sub>(2)
113+
#[unstable(feature = "f128", issue = "116909")]
114+
pub const LOG10_2: f128 = 0.301029995663981195213738894724493026768189881462108541310427_f128;
115+
116+
/// log<sub>10</sub>(e)
117+
#[unstable(feature = "f128", issue = "116909")]
118+
pub const LOG10_E: f128 = 0.434294481903251827651128918916605082294397005803666566114454_f128;
119+
120+
/// ln(2)
121+
#[unstable(feature = "f128", issue = "116909")]
122+
pub const LN_2: f128 = 0.693147180559945309417232121458176568075500134360255254120680_f128;
123+
124+
/// ln(10)
125+
#[unstable(feature = "f128", issue = "116909")]
126+
pub const LN_10: f128 = 2.30258509299404568401799145468436420760110148862877297603333_f128;
127+
}
19128

20129
#[cfg(not(test))]
21130
impl f128 {
22-
// FIXME(f16_f128): almost everything in this `impl` is missing examples and a const
131+
// FIXME(f16_f128): almost all methods in this `impl` are missing examples and a const
23132
// implementation. Add these once we can run code on all platforms and have f16/f128 in CTFE.
24133

134+
/// The radix or base of the internal representation of `f128`.
135+
#[unstable(feature = "f128", issue = "116909")]
136+
pub const RADIX: u32 = 2;
137+
138+
/// Number of significant digits in base 2.
139+
#[unstable(feature = "f128", issue = "116909")]
140+
pub const MANTISSA_DIGITS: u32 = 113;
141+
142+
/// Approximate number of significant digits in base 10.
143+
///
144+
/// This is the maximum <i>x</i> such that any decimal number with <i>x</i>
145+
/// significant digits can be converted to `f128` and back without loss.
146+
///
147+
/// Equal to floor(log<sub>10</sub>&nbsp;2<sup>[`MANTISSA_DIGITS`]&nbsp;&minus;&nbsp;1</sup>).
148+
///
149+
/// [`MANTISSA_DIGITS`]: f128::MANTISSA_DIGITS
150+
#[unstable(feature = "f128", issue = "116909")]
151+
pub const DIGITS: u32 = 33;
152+
153+
/// [Machine epsilon] value for `f128`.
154+
///
155+
/// This is the difference between `1.0` and the next larger representable number.
156+
///
157+
/// Equal to 2<sup>1&nbsp;&minus;&nbsp;[`MANTISSA_DIGITS`]</sup>.
158+
///
159+
/// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon
160+
/// [`MANTISSA_DIGITS`]: f128::MANTISSA_DIGITS
161+
#[unstable(feature = "f128", issue = "116909")]
162+
pub const EPSILON: f128 = 1.92592994438723585305597794258492731e-34_f128;
163+
164+
/// Smallest finite `f128` value.
165+
///
166+
/// Equal to &minus;[`MAX`].
167+
///
168+
/// [`MAX`]: f128::MAX
169+
#[unstable(feature = "f128", issue = "116909")]
170+
pub const MIN: f128 = -1.18973149535723176508575932662800701e+4932_f128;
171+
/// Smallest positive normal `f128` value.
172+
///
173+
/// Equal to 2<sup>[`MIN_EXP`]&nbsp;&minus;&nbsp;1</sup>.
174+
///
175+
/// [`MIN_EXP`]: f128::MIN_EXP
176+
#[unstable(feature = "f128", issue = "116909")]
177+
pub const MIN_POSITIVE: f128 = 3.36210314311209350626267781732175260e-4932_f128;
178+
/// Largest finite `f128` value.
179+
///
180+
/// Equal to
181+
/// (1&nbsp;&minus;&nbsp;2<sup>&minus;[`MANTISSA_DIGITS`]</sup>)&nbsp;2<sup>[`MAX_EXP`]</sup>.
182+
///
183+
/// [`MANTISSA_DIGITS`]: f128::MANTISSA_DIGITS
184+
/// [`MAX_EXP`]: f128::MAX_EXP
185+
#[unstable(feature = "f128", issue = "116909")]
186+
pub const MAX: f128 = 1.18973149535723176508575932662800701e+4932_f128;
187+
188+
/// One greater than the minimum possible normal power of 2 exponent.
189+
///
190+
/// If <i>x</i>&nbsp;=&nbsp;`MIN_EXP`, then normal numbers
191+
/// ≥&nbsp;0.5&nbsp;×&nbsp;2<sup><i>x</i></sup>.
192+
#[unstable(feature = "f128", issue = "116909")]
193+
pub const MIN_EXP: i32 = -16_381;
194+
/// Maximum possible power of 2 exponent.
195+
///
196+
/// If <i>x</i>&nbsp;=&nbsp;`MAX_EXP`, then normal numbers
197+
/// &lt;&nbsp;1&nbsp;×&nbsp;2<sup><i>x</i></sup>.
198+
#[unstable(feature = "f128", issue = "116909")]
199+
pub const MAX_EXP: i32 = 16_384;
200+
201+
/// Minimum <i>x</i> for which 10<sup><i>x</i></sup> is normal.
202+
///
203+
/// Equal to ceil(log<sub>10</sub>&nbsp;[`MIN_POSITIVE`]).
204+
///
205+
/// [`MIN_POSITIVE`]: f128::MIN_POSITIVE
206+
#[unstable(feature = "f128", issue = "116909")]
207+
pub const MIN_10_EXP: i32 = -4_931;
208+
/// Maximum <i>x</i> for which 10<sup><i>x</i></sup> is normal.
209+
///
210+
/// Equal to floor(log<sub>10</sub>&nbsp;[`MAX`]).
211+
///
212+
/// [`MAX`]: f128::MAX
213+
#[unstable(feature = "f128", issue = "116909")]
214+
pub const MAX_10_EXP: i32 = 4_932;
215+
25216
/// Returns `true` if this value is NaN.
26217
#[inline]
27218
#[must_use]

0 commit comments

Comments
 (0)