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.
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.
11 //! Operations and constants for 32-bits floats (`f32` type)
13 #![doc(primitive = "f32")]
14 // FIXME: MIN_VALUE and MAX_VALUE literals are parsed as -inf and inf #14353
15 #![allow(type_overflow)]
19 use num::{FPNormal, FPCategory, FPZero, FPSubnormal, FPInfinite, FPNaN};
23 pub static RADIX: uint = 2u;
25 pub static MANTISSA_DIGITS: uint = 24u;
26 pub static DIGITS: uint = 6u;
28 pub static EPSILON: f32 = 1.19209290e-07_f32;
30 /// Smallest finite f32 value
31 pub static MIN_VALUE: f32 = -3.40282347e+38_f32;
32 /// Smallest positive, normalized f32 value
33 pub static MIN_POS_VALUE: f32 = 1.17549435e-38_f32;
34 /// Largest finite f32 value
35 pub static MAX_VALUE: f32 = 3.40282347e+38_f32;
37 pub static MIN_EXP: int = -125;
38 pub static MAX_EXP: int = 128;
40 pub static MIN_10_EXP: int = -37;
41 pub static MAX_10_EXP: int = 38;
43 pub static NAN: f32 = 0.0_f32/0.0_f32;
44 pub static INFINITY: f32 = 1.0_f32/0.0_f32;
45 pub static NEG_INFINITY: f32 = -1.0_f32/0.0_f32;
47 /// Various useful constants.
49 // FIXME: replace with mathematical constants from cmath.
51 // FIXME(#5527): These constants should be deprecated once associated
52 // constants are implemented in favour of referencing the respective members
55 /// Archimedes' constant
56 pub static PI: f32 = 3.14159265358979323846264338327950288_f32;
59 pub static PI_2: f32 = 6.28318530717958647692528676655900576_f32;
62 pub static FRAC_PI_2: f32 = 1.57079632679489661923132169163975144_f32;
65 pub static FRAC_PI_3: f32 = 1.04719755119659774615421446109316763_f32;
68 pub static FRAC_PI_4: f32 = 0.785398163397448309615660845819875721_f32;
71 pub static FRAC_PI_6: f32 = 0.52359877559829887307710723054658381_f32;
74 pub static FRAC_PI_8: f32 = 0.39269908169872415480783042290993786_f32;
77 pub static FRAC_1_PI: f32 = 0.318309886183790671537767526745028724_f32;
80 pub static FRAC_2_PI: f32 = 0.636619772367581343075535053490057448_f32;
83 pub static FRAC_2_SQRTPI: f32 = 1.12837916709551257389615890312154517_f32;
86 pub static SQRT2: f32 = 1.41421356237309504880168872420969808_f32;
89 pub static FRAC_1_SQRT2: f32 = 0.707106781186547524400844362104849039_f32;
92 pub static E: f32 = 2.71828182845904523536028747135266250_f32;
95 pub static LOG2_E: f32 = 1.44269504088896340735992468100189214_f32;
98 pub static LOG10_E: f32 = 0.434294481903251827651128918916605082_f32;
101 pub static LN_2: f32 = 0.693147180559945309417232121458176568_f32;
104 pub static LN_10: f32 = 2.30258509299404568401799145468436421_f32;
109 fn nan() -> f32 { NAN }
112 fn infinity() -> f32 { INFINITY }
115 fn neg_infinity() -> f32 { NEG_INFINITY }
118 fn neg_zero() -> f32 { -0.0 }
120 /// Returns `true` if the number is NaN.
122 fn is_nan(self) -> bool { self != self }
124 /// Returns `true` if the number is infinite.
126 fn is_infinite(self) -> bool {
127 self == Float::infinity() || self == Float::neg_infinity()
130 /// Returns `true` if the number is neither infinite or NaN.
132 fn is_finite(self) -> bool {
133 !(self.is_nan() || self.is_infinite())
136 /// Returns `true` if the number is neither zero, infinite, subnormal or NaN.
138 fn is_normal(self) -> bool {
139 self.classify() == FPNormal
142 /// Returns the floating point category of the number. If only one property
143 /// is going to be tested, it is generally faster to use the specific
144 /// predicate instead.
145 fn classify(self) -> FPCategory {
146 static EXP_MASK: u32 = 0x7f800000;
147 static MAN_MASK: u32 = 0x007fffff;
149 let bits: u32 = unsafe { mem::transmute(self) };
150 match (bits & MAN_MASK, bits & EXP_MASK) {
152 (_, 0) => FPSubnormal,
153 (0, EXP_MASK) => FPInfinite,
154 (_, EXP_MASK) => FPNaN,
160 fn mantissa_digits(_: Option<f32>) -> uint { MANTISSA_DIGITS }
163 fn digits(_: Option<f32>) -> uint { DIGITS }
166 fn epsilon() -> f32 { EPSILON }
169 fn min_exp(_: Option<f32>) -> int { MIN_EXP }
172 fn max_exp(_: Option<f32>) -> int { MAX_EXP }
175 fn min_10_exp(_: Option<f32>) -> int { MIN_10_EXP }
178 fn max_10_exp(_: Option<f32>) -> int { MAX_10_EXP }
181 fn min_pos_value(_: Option<f32>) -> f32 { MIN_POS_VALUE }
183 /// Returns the mantissa, exponent and sign as integers.
184 fn integer_decode(self) -> (u64, i16, i8) {
185 let bits: u32 = unsafe { mem::transmute(self) };
186 let sign: i8 = if bits >> 31 == 0 { 1 } else { -1 };
187 let mut exponent: i16 = ((bits >> 23) & 0xff) as i16;
188 let mantissa = if exponent == 0 {
189 (bits & 0x7fffff) << 1
191 (bits & 0x7fffff) | 0x800000
193 // Exponent bias + mantissa shift
194 exponent -= 127 + 23;
195 (mantissa as u64, exponent, sign)
198 /// Rounds towards minus infinity.
200 fn floor(self) -> f32 {
201 unsafe { intrinsics::floorf32(self) }
204 /// Rounds towards plus infinity.
206 fn ceil(self) -> f32 {
207 unsafe { intrinsics::ceilf32(self) }
210 /// Rounds to nearest integer. Rounds half-way cases away from zero.
212 fn round(self) -> f32 {
213 unsafe { intrinsics::roundf32(self) }
216 /// Returns the integer part of the number (rounds towards zero).
218 fn trunc(self) -> f32 {
219 unsafe { intrinsics::truncf32(self) }
222 /// The fractional part of the number, satisfying:
226 /// assert!(x == x.trunc() + x.fract())
229 fn fract(self) -> f32 { self - self.trunc() }
231 /// Fused multiply-add. Computes `(self * a) + b` with only one rounding
232 /// error. This produces a more accurate result with better performance than
233 /// a separate multiplication operation followed by an add.
235 fn mul_add(self, a: f32, b: f32) -> f32 {
236 unsafe { intrinsics::fmaf32(self, a, b) }
239 /// Returns the reciprocal (multiplicative inverse) of the number.
241 fn recip(self) -> f32 { 1.0 / self }
243 fn powi(self, n: i32) -> f32 {
244 unsafe { intrinsics::powif32(self, n) }
248 fn powf(self, n: f32) -> f32 {
249 unsafe { intrinsics::powf32(self, n) }
254 fn sqrt2() -> f32 { consts::SQRT2 }
258 fn frac_1_sqrt2() -> f32 { consts::FRAC_1_SQRT2 }
261 fn sqrt(self) -> f32 {
262 unsafe { intrinsics::sqrtf32(self) }
266 fn rsqrt(self) -> f32 { self.sqrt().recip() }
268 /// Archimedes' constant
270 fn pi() -> f32 { consts::PI }
274 fn two_pi() -> f32 { consts::PI_2 }
278 fn frac_pi_2() -> f32 { consts::FRAC_PI_2 }
282 fn frac_pi_3() -> f32 { consts::FRAC_PI_3 }
286 fn frac_pi_4() -> f32 { consts::FRAC_PI_4 }
290 fn frac_pi_6() -> f32 { consts::FRAC_PI_6 }
294 fn frac_pi_8() -> f32 { consts::FRAC_PI_8 }
298 fn frac_1_pi() -> f32 { consts::FRAC_1_PI }
302 fn frac_2_pi() -> f32 { consts::FRAC_2_PI }
306 fn frac_2_sqrtpi() -> f32 { consts::FRAC_2_SQRTPI }
310 fn e() -> f32 { consts::E }
314 fn log2_e() -> f32 { consts::LOG2_E }
318 fn log10_e() -> f32 { consts::LOG10_E }
322 fn ln_2() -> f32 { consts::LN_2 }
326 fn ln_10() -> f32 { consts::LN_10 }
328 /// Returns the exponential of the number.
330 fn exp(self) -> f32 {
331 unsafe { intrinsics::expf32(self) }
334 /// Returns 2 raised to the power of the number.
336 fn exp2(self) -> f32 {
337 unsafe { intrinsics::exp2f32(self) }
340 /// Returns the natural logarithm of the number.
343 unsafe { intrinsics::logf32(self) }
346 /// Returns the logarithm of the number with respect to an arbitrary base.
348 fn log(self, base: f32) -> f32 { self.ln() / base.ln() }
350 /// Returns the base 2 logarithm of the number.
352 fn log2(self) -> f32 {
353 unsafe { intrinsics::log2f32(self) }
356 /// Returns the base 10 logarithm of the number.
358 fn log10(self) -> f32 {
359 unsafe { intrinsics::log10f32(self) }
362 /// Converts to degrees, assuming the number is in radians.
364 fn to_degrees(self) -> f32 { self * (180.0f32 / Float::pi()) }
366 /// Converts to radians, assuming the number is in degrees.
368 fn to_radians(self) -> f32 {
369 let value: f32 = Float::pi();
370 self * (value / 180.0f32)