]> git.proxmox.com Git - rustc.git/blame - src/libcore/num/f64.rs
Imported Upstream version 1.9.0+dfsg1
[rustc.git] / src / libcore / num / f64.rs
CommitLineData
1a4d82fc
JJ
1// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2// file at the top-level directory of this distribution and at
3// http://rust-lang.org/COPYRIGHT.
4//
5// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8// option. This file may not be copied, modified, or distributed
9// except according to those terms.
10
11//! Operations and constants for 64-bits floats (`f64` type)
12
1a4d82fc
JJ
13// FIXME: MIN_VALUE and MAX_VALUE literals are parsed as -inf and inf #14353
14#![allow(overflowing_literals)]
15
85aaf69f 16#![stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
17
18use intrinsics;
19use mem;
1a4d82fc 20use num::FpCategory as Fp;
9cc50fc6 21use num::Float;
1a4d82fc 22
c34b1796 23#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 24#[allow(missing_docs)]
c34b1796 25pub const RADIX: u32 = 2;
1a4d82fc 26
c34b1796 27#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 28#[allow(missing_docs)]
c34b1796
AL
29pub const MANTISSA_DIGITS: u32 = 53;
30#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 31#[allow(missing_docs)]
c34b1796 32pub const DIGITS: u32 = 15;
1a4d82fc 33
85aaf69f 34#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 35#[allow(missing_docs)]
1a4d82fc
JJ
36pub const EPSILON: f64 = 2.2204460492503131e-16_f64;
37
85aaf69f
SL
38/// Smallest finite f64 value
39#[stable(feature = "rust1", since = "1.0.0")]
40pub const MIN: f64 = -1.7976931348623157e+308_f64;
41/// Smallest positive, normalized f64 value
42#[stable(feature = "rust1", since = "1.0.0")]
43pub const MIN_POSITIVE: f64 = 2.2250738585072014e-308_f64;
44/// Largest finite f64 value
45#[stable(feature = "rust1", since = "1.0.0")]
46pub const MAX: f64 = 1.7976931348623157e+308_f64;
47
c34b1796 48#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 49#[allow(missing_docs)]
c34b1796
AL
50pub const MIN_EXP: i32 = -1021;
51#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 52#[allow(missing_docs)]
c34b1796 53pub const MAX_EXP: i32 = 1024;
1a4d82fc 54
c34b1796 55#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 56#[allow(missing_docs)]
c34b1796
AL
57pub const MIN_10_EXP: i32 = -307;
58#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 59#[allow(missing_docs)]
c34b1796 60pub const MAX_10_EXP: i32 = 308;
1a4d82fc 61
85aaf69f 62#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 63#[allow(missing_docs)]
1a4d82fc 64pub const NAN: f64 = 0.0_f64/0.0_f64;
85aaf69f 65#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 66#[allow(missing_docs)]
1a4d82fc 67pub const INFINITY: f64 = 1.0_f64/0.0_f64;
85aaf69f 68#[stable(feature = "rust1", since = "1.0.0")]
c1a9b12d 69#[allow(missing_docs)]
1a4d82fc
JJ
70pub const NEG_INFINITY: f64 = -1.0_f64/0.0_f64;
71
b039eaaf 72/// Basic mathematical constants.
c34b1796 73#[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
74pub mod consts {
75 // FIXME: replace with mathematical constants from cmath.
76
1a4d82fc 77 /// Archimedes' constant
c34b1796 78 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
79 pub const PI: f64 = 3.14159265358979323846264338327950288_f64;
80
1a4d82fc 81 /// pi/2.0
c34b1796 82 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
83 pub const FRAC_PI_2: f64 = 1.57079632679489661923132169163975144_f64;
84
85 /// pi/3.0
c34b1796 86 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
87 pub const FRAC_PI_3: f64 = 1.04719755119659774615421446109316763_f64;
88
89 /// pi/4.0
c34b1796 90 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
91 pub const FRAC_PI_4: f64 = 0.785398163397448309615660845819875721_f64;
92
93 /// pi/6.0
c34b1796 94 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
95 pub const FRAC_PI_6: f64 = 0.52359877559829887307710723054658381_f64;
96
97 /// pi/8.0
c34b1796 98 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
99 pub const FRAC_PI_8: f64 = 0.39269908169872415480783042290993786_f64;
100
101 /// 1.0/pi
c34b1796 102 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
103 pub const FRAC_1_PI: f64 = 0.318309886183790671537767526745028724_f64;
104
105 /// 2.0/pi
c34b1796 106 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
107 pub const FRAC_2_PI: f64 = 0.636619772367581343075535053490057448_f64;
108
109 /// 2.0/sqrt(pi)
c34b1796
AL
110 #[stable(feature = "rust1", since = "1.0.0")]
111 pub const FRAC_2_SQRT_PI: f64 = 1.12837916709551257389615890312154517_f64;
112
1a4d82fc 113 /// sqrt(2.0)
c34b1796
AL
114 #[stable(feature = "rust1", since = "1.0.0")]
115 pub const SQRT_2: f64 = 1.41421356237309504880168872420969808_f64;
116
1a4d82fc 117 /// 1.0/sqrt(2.0)
c34b1796
AL
118 #[stable(feature = "rust1", since = "1.0.0")]
119 pub const FRAC_1_SQRT_2: f64 = 0.707106781186547524400844362104849039_f64;
120
1a4d82fc 121 /// Euler's number
c34b1796 122 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
123 pub const E: f64 = 2.71828182845904523536028747135266250_f64;
124
125 /// log2(e)
c34b1796 126 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
127 pub const LOG2_E: f64 = 1.44269504088896340735992468100189214_f64;
128
129 /// log10(e)
c34b1796 130 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
131 pub const LOG10_E: f64 = 0.434294481903251827651128918916605082_f64;
132
133 /// ln(2.0)
c34b1796 134 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
135 pub const LN_2: f64 = 0.693147180559945309417232121458176568_f64;
136
137 /// ln(10.0)
c34b1796 138 #[stable(feature = "rust1", since = "1.0.0")]
1a4d82fc
JJ
139 pub const LN_10: f64 = 2.30258509299404568401799145468436421_f64;
140}
141
92a42be0
SL
142#[unstable(feature = "core_float",
143 reason = "stable interface is via `impl f{32,64}` in later crates",
54a0048b 144 issue = "32110")]
1a4d82fc
JJ
145impl Float for f64 {
146 #[inline]
147 fn nan() -> f64 { NAN }
148
149 #[inline]
150 fn infinity() -> f64 { INFINITY }
151
152 #[inline]
153 fn neg_infinity() -> f64 { NEG_INFINITY }
154
155 #[inline]
156 fn zero() -> f64 { 0.0 }
157
158 #[inline]
159 fn neg_zero() -> f64 { -0.0 }
160
161 #[inline]
162 fn one() -> f64 { 1.0 }
163
164 /// Returns `true` if the number is NaN.
165 #[inline]
166 fn is_nan(self) -> bool { self != self }
167
168 /// Returns `true` if the number is infinite.
169 #[inline]
170 fn is_infinite(self) -> bool {
171 self == Float::infinity() || self == Float::neg_infinity()
172 }
173
174 /// Returns `true` if the number is neither infinite or NaN.
175 #[inline]
176 fn is_finite(self) -> bool {
177 !(self.is_nan() || self.is_infinite())
178 }
179
180 /// Returns `true` if the number is neither zero, infinite, subnormal or NaN.
181 #[inline]
182 fn is_normal(self) -> bool {
183 self.classify() == Fp::Normal
184 }
185
186 /// Returns the floating point category of the number. If only one property
187 /// is going to be tested, it is generally faster to use the specific
188 /// predicate instead.
189 fn classify(self) -> Fp {
190 const EXP_MASK: u64 = 0x7ff0000000000000;
191 const MAN_MASK: u64 = 0x000fffffffffffff;
192
193 let bits: u64 = unsafe { mem::transmute(self) };
194 match (bits & MAN_MASK, bits & EXP_MASK) {
195 (0, 0) => Fp::Zero,
196 (_, 0) => Fp::Subnormal,
197 (0, EXP_MASK) => Fp::Infinite,
198 (_, EXP_MASK) => Fp::Nan,
199 _ => Fp::Normal,
200 }
201 }
202
1a4d82fc
JJ
203 /// Returns the mantissa, exponent and sign as integers.
204 fn integer_decode(self) -> (u64, i16, i8) {
205 let bits: u64 = unsafe { mem::transmute(self) };
206 let sign: i8 = if bits >> 63 == 0 { 1 } else { -1 };
207 let mut exponent: i16 = ((bits >> 52) & 0x7ff) as i16;
208 let mantissa = if exponent == 0 {
209 (bits & 0xfffffffffffff) << 1
210 } else {
211 (bits & 0xfffffffffffff) | 0x10000000000000
212 };
213 // Exponent bias + mantissa shift
214 exponent -= 1023 + 52;
215 (mantissa, exponent, sign)
216 }
217
1a4d82fc
JJ
218 /// Computes the absolute value of `self`. Returns `Float::nan()` if the
219 /// number is `Float::nan()`.
220 #[inline]
221 fn abs(self) -> f64 {
222 unsafe { intrinsics::fabsf64(self) }
223 }
224
225 /// Returns a number that represents the sign of `self`.
226 ///
227 /// - `1.0` if the number is positive, `+0.0` or `Float::infinity()`
228 /// - `-1.0` if the number is negative, `-0.0` or `Float::neg_infinity()`
229 /// - `Float::nan()` if the number is `Float::nan()`
230 #[inline]
231 fn signum(self) -> f64 {
232 if self.is_nan() {
233 Float::nan()
234 } else {
235 unsafe { intrinsics::copysignf64(1.0, self) }
236 }
237 }
238
239 /// Returns `true` if `self` is positive, including `+0.0` and
240 /// `Float::infinity()`.
241 #[inline]
92a42be0 242 fn is_sign_positive(self) -> bool {
1a4d82fc
JJ
243 self > 0.0 || (1.0 / self) == Float::infinity()
244 }
245
246 /// Returns `true` if `self` is negative, including `-0.0` and
247 /// `Float::neg_infinity()`.
248 #[inline]
92a42be0 249 fn is_sign_negative(self) -> bool {
1a4d82fc
JJ
250 self < 0.0 || (1.0 / self) == Float::neg_infinity()
251 }
252
1a4d82fc
JJ
253 /// Returns the reciprocal (multiplicative inverse) of the number.
254 #[inline]
255 fn recip(self) -> f64 { 1.0 / self }
256
1a4d82fc
JJ
257 #[inline]
258 fn powi(self, n: i32) -> f64 {
259 unsafe { intrinsics::powif64(self, n) }
260 }
261
1a4d82fc
JJ
262 /// Converts to degrees, assuming the number is in radians.
263 #[inline]
264 fn to_degrees(self) -> f64 { self * (180.0f64 / consts::PI) }
265
266 /// Converts to radians, assuming the number is in degrees.
267 #[inline]
268 fn to_radians(self) -> f64 {
269 let value: f64 = consts::PI;
270 self * (value / 180.0)
271 }
272}