rust/src/libstd/num/f32.rs
2015-01-06 23:21:27 +11:00

820 lines
26 KiB
Rust

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Operations and constants for 32-bits floats (`f32` type)
#![stable]
#![allow(missing_docs)]
#![allow(unsigned_negation)]
#![doc(primitive = "f32")]
use prelude::v1::*;
use intrinsics;
use libc::c_int;
use num::{Float, FpCategory};
use num::strconv;
use num::strconv::ExponentFormat::{ExpNone, ExpDec};
use num::strconv::SignificantDigits::{DigAll, DigMax, DigExact};
use num::strconv::SignFormat::SignNeg;
use core::num;
pub use core::f32::{RADIX, MANTISSA_DIGITS, DIGITS, EPSILON, MIN_VALUE};
pub use core::f32::{MIN_POS_VALUE, MAX_VALUE, MIN_EXP, MAX_EXP, MIN_10_EXP};
pub use core::f32::{MAX_10_EXP, NAN, INFINITY, NEG_INFINITY};
pub use core::f32::consts;
#[allow(dead_code)]
mod cmath {
use libc::{c_float, c_int};
#[link_name = "m"]
extern {
pub fn acosf(n: c_float) -> c_float;
pub fn asinf(n: c_float) -> c_float;
pub fn atanf(n: c_float) -> c_float;
pub fn atan2f(a: c_float, b: c_float) -> c_float;
pub fn cbrtf(n: c_float) -> c_float;
pub fn coshf(n: c_float) -> c_float;
pub fn erff(n: c_float) -> c_float;
pub fn erfcf(n: c_float) -> c_float;
pub fn expm1f(n: c_float) -> c_float;
pub fn fdimf(a: c_float, b: c_float) -> c_float;
pub fn frexpf(n: c_float, value: &mut c_int) -> c_float;
pub fn fmaxf(a: c_float, b: c_float) -> c_float;
pub fn fminf(a: c_float, b: c_float) -> c_float;
pub fn fmodf(a: c_float, b: c_float) -> c_float;
pub fn nextafterf(x: c_float, y: c_float) -> c_float;
pub fn hypotf(x: c_float, y: c_float) -> c_float;
pub fn ldexpf(x: c_float, n: c_int) -> c_float;
pub fn logbf(n: c_float) -> c_float;
pub fn log1pf(n: c_float) -> c_float;
pub fn ilogbf(n: c_float) -> c_int;
pub fn modff(n: c_float, iptr: &mut c_float) -> c_float;
pub fn sinhf(n: c_float) -> c_float;
pub fn tanf(n: c_float) -> c_float;
pub fn tanhf(n: c_float) -> c_float;
pub fn tgammaf(n: c_float) -> c_float;
#[cfg(unix)]
pub fn lgammaf_r(n: c_float, sign: &mut c_int) -> c_float;
#[cfg(windows)]
#[link_name="__lgammaf_r"]
pub fn lgammaf_r(n: c_float, sign: &mut c_int) -> c_float;
}
}
#[stable]
impl Float for f32 {
#[inline]
fn nan() -> f32 { num::Float::nan() }
#[inline]
fn infinity() -> f32 { num::Float::infinity() }
#[inline]
fn neg_infinity() -> f32 { num::Float::neg_infinity() }
#[inline]
fn zero() -> f32 { num::Float::zero() }
#[inline]
fn neg_zero() -> f32 { num::Float::neg_zero() }
#[inline]
fn one() -> f32 { num::Float::one() }
#[allow(deprecated)]
#[inline]
fn mantissa_digits(unused_self: Option<f32>) -> uint {
num::Float::mantissa_digits(unused_self)
}
#[allow(deprecated)]
#[inline]
fn digits(unused_self: Option<f32>) -> uint { num::Float::digits(unused_self) }
#[allow(deprecated)]
#[inline]
fn epsilon() -> f32 { num::Float::epsilon() }
#[allow(deprecated)]
#[inline]
fn min_exp(unused_self: Option<f32>) -> int { num::Float::min_exp(unused_self) }
#[allow(deprecated)]
#[inline]
fn max_exp(unused_self: Option<f32>) -> int { num::Float::max_exp(unused_self) }
#[allow(deprecated)]
#[inline]
fn min_10_exp(unused_self: Option<f32>) -> int { num::Float::min_10_exp(unused_self) }
#[allow(deprecated)]
#[inline]
fn max_10_exp(unused_self: Option<f32>) -> int { num::Float::max_10_exp(unused_self) }
#[allow(deprecated)]
#[inline]
fn min_value() -> f32 { num::Float::min_value() }
#[allow(deprecated)]
#[inline]
fn min_pos_value(unused_self: Option<f32>) -> f32 { num::Float::min_pos_value(unused_self) }
#[allow(deprecated)]
#[inline]
fn max_value() -> f32 { num::Float::max_value() }
#[inline]
fn is_nan(self) -> bool { num::Float::is_nan(self) }
#[inline]
fn is_infinite(self) -> bool { num::Float::is_infinite(self) }
#[inline]
fn is_finite(self) -> bool { num::Float::is_finite(self) }
#[inline]
fn is_normal(self) -> bool { num::Float::is_normal(self) }
#[inline]
fn classify(self) -> FpCategory { num::Float::classify(self) }
#[inline]
fn integer_decode(self) -> (u64, i16, i8) { num::Float::integer_decode(self) }
#[inline]
fn floor(self) -> f32 { num::Float::floor(self) }
#[inline]
fn ceil(self) -> f32 { num::Float::ceil(self) }
#[inline]
fn round(self) -> f32 { num::Float::round(self) }
#[inline]
fn trunc(self) -> f32 { num::Float::trunc(self) }
#[inline]
fn fract(self) -> f32 { num::Float::fract(self) }
#[inline]
fn abs(self) -> f32 { num::Float::abs(self) }
#[inline]
fn signum(self) -> f32 { num::Float::signum(self) }
#[inline]
fn is_positive(self) -> bool { num::Float::is_positive(self) }
#[inline]
fn is_negative(self) -> bool { num::Float::is_negative(self) }
#[inline]
fn mul_add(self, a: f32, b: f32) -> f32 { num::Float::mul_add(self, a, b) }
#[inline]
fn recip(self) -> f32 { num::Float::recip(self) }
#[inline]
fn powi(self, n: i32) -> f32 { num::Float::powi(self, n) }
#[inline]
fn powf(self, n: f32) -> f32 { num::Float::powf(self, n) }
#[inline]
fn sqrt(self) -> f32 { num::Float::sqrt(self) }
#[inline]
fn rsqrt(self) -> f32 { num::Float::rsqrt(self) }
#[inline]
fn exp(self) -> f32 { num::Float::exp(self) }
#[inline]
fn exp2(self) -> f32 { num::Float::exp(self) }
#[inline]
fn ln(self) -> f32 { num::Float::ln(self) }
#[inline]
fn log(self, base: f32) -> f32 { num::Float::log(self, base) }
#[inline]
fn log2(self) -> f32 { num::Float::log2(self) }
#[inline]
fn log10(self) -> f32 { num::Float::log10(self) }
#[inline]
fn to_degrees(self) -> f32 { num::Float::to_degrees(self) }
#[inline]
fn to_radians(self) -> f32 { num::Float::to_radians(self) }
/// Constructs a floating point number by multiplying `x` by 2 raised to the
/// power of `exp`
#[inline]
fn ldexp(x: f32, exp: int) -> f32 {
unsafe { cmath::ldexpf(x, exp as c_int) }
}
/// Breaks the number into a normalized fraction and a base-2 exponent,
/// satisfying:
///
/// - `self = x * pow(2, exp)`
/// - `0.5 <= abs(x) < 1.0`
#[inline]
fn frexp(self) -> (f32, int) {
unsafe {
let mut exp = 0;
let x = cmath::frexpf(self, &mut exp);
(x, exp as int)
}
}
/// Returns the next representable floating-point value in the direction of
/// `other`.
#[inline]
fn next_after(self, other: f32) -> f32 {
unsafe { cmath::nextafterf(self, other) }
}
#[inline]
fn max(self, other: f32) -> f32 {
unsafe { cmath::fmaxf(self, other) }
}
#[inline]
fn min(self, other: f32) -> f32 {
unsafe { cmath::fminf(self, other) }
}
#[inline]
fn abs_sub(self, other: f32) -> f32 {
unsafe { cmath::fdimf(self, other) }
}
#[inline]
fn cbrt(self) -> f32 {
unsafe { cmath::cbrtf(self) }
}
#[inline]
fn hypot(self, other: f32) -> f32 {
unsafe { cmath::hypotf(self, other) }
}
#[inline]
fn sin(self) -> f32 {
unsafe { intrinsics::sinf32(self) }
}
#[inline]
fn cos(self) -> f32 {
unsafe { intrinsics::cosf32(self) }
}
#[inline]
fn tan(self) -> f32 {
unsafe { cmath::tanf(self) }
}
#[inline]
fn asin(self) -> f32 {
unsafe { cmath::asinf(self) }
}
#[inline]
fn acos(self) -> f32 {
unsafe { cmath::acosf(self) }
}
#[inline]
fn atan(self) -> f32 {
unsafe { cmath::atanf(self) }
}
#[inline]
fn atan2(self, other: f32) -> f32 {
unsafe { cmath::atan2f(self, other) }
}
/// Simultaneously computes the sine and cosine of the number
#[inline]
fn sin_cos(self) -> (f32, f32) {
(self.sin(), self.cos())
}
/// Returns the exponential of the number, minus `1`, in a way that is
/// accurate even if the number is close to zero
#[inline]
fn exp_m1(self) -> f32 {
unsafe { cmath::expm1f(self) }
}
/// Returns the natural logarithm of the number plus `1` (`ln(1+n)`) more
/// accurately than if the operations were performed separately
#[inline]
fn ln_1p(self) -> f32 {
unsafe { cmath::log1pf(self) }
}
#[inline]
fn sinh(self) -> f32 {
unsafe { cmath::sinhf(self) }
}
#[inline]
fn cosh(self) -> f32 {
unsafe { cmath::coshf(self) }
}
#[inline]
fn tanh(self) -> f32 {
unsafe { cmath::tanhf(self) }
}
/// Inverse hyperbolic sine
///
/// # Returns
///
/// - on success, the inverse hyperbolic sine of `self` will be returned
/// - `self` if `self` is `0.0`, `-0.0`, `INFINITY`, or `NEG_INFINITY`
/// - `NAN` if `self` is `NAN`
#[inline]
fn asinh(self) -> f32 {
match self {
NEG_INFINITY => NEG_INFINITY,
x => (x + ((x * x) + 1.0).sqrt()).ln(),
}
}
/// Inverse hyperbolic cosine
///
/// # Returns
///
/// - on success, the inverse hyperbolic cosine of `self` will be returned
/// - `INFINITY` if `self` is `INFINITY`
/// - `NAN` if `self` is `NAN` or `self < 1.0` (including `NEG_INFINITY`)
#[inline]
fn acosh(self) -> f32 {
match self {
x if x < 1.0 => Float::nan(),
x => (x + ((x * x) - 1.0).sqrt()).ln(),
}
}
/// Inverse hyperbolic tangent
///
/// # Returns
///
/// - on success, the inverse hyperbolic tangent of `self` will be returned
/// - `self` if `self` is `0.0` or `-0.0`
/// - `INFINITY` if `self` is `1.0`
/// - `NEG_INFINITY` if `self` is `-1.0`
/// - `NAN` if the `self` is `NAN` or outside the domain of `-1.0 <= self <= 1.0`
/// (including `INFINITY` and `NEG_INFINITY`)
#[inline]
fn atanh(self) -> f32 {
0.5 * ((2.0 * self) / (1.0 - self)).ln_1p()
}
}
//
// Section: String Conversions
//
/// Converts a float to a string
///
/// # Arguments
///
/// * num - The float value
#[inline]
#[experimental = "may be removed or relocated"]
pub fn to_string(num: f32) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, SignNeg, DigAll, ExpNone, false);
r
}
/// Converts a float to a string in hexadecimal format
///
/// # Arguments
///
/// * num - The float value
#[inline]
#[experimental = "may be removed or relocated"]
pub fn to_str_hex(num: f32) -> String {
let (r, _) = strconv::float_to_str_common(
num, 16u, true, SignNeg, DigAll, ExpNone, false);
r
}
/// Converts a float to a string in a given radix, and a flag indicating
/// whether it's a special value
///
/// # Arguments
///
/// * num - The float value
/// * radix - The base to use
#[inline]
#[experimental = "may be removed or relocated"]
pub fn to_str_radix_special(num: f32, rdx: uint) -> (String, bool) {
strconv::float_to_str_common(num, rdx, true, SignNeg, DigAll, ExpNone, false)
}
/// Converts a float to a string with exactly the number of
/// provided significant digits
///
/// # Arguments
///
/// * num - The float value
/// * digits - The number of significant digits
#[inline]
#[experimental = "may be removed or relocated"]
pub fn to_str_exact(num: f32, dig: uint) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, SignNeg, DigExact(dig), ExpNone, false);
r
}
/// Converts a float to a string with a maximum number of
/// significant digits
///
/// # Arguments
///
/// * num - The float value
/// * digits - The number of significant digits
#[inline]
#[experimental = "may be removed or relocated"]
pub fn to_str_digits(num: f32, dig: uint) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, SignNeg, DigMax(dig), ExpNone, false);
r
}
/// Converts a float to a string using the exponential notation with exactly the number of
/// provided digits after the decimal point in the significand
///
/// # Arguments
///
/// * num - The float value
/// * digits - The number of digits after the decimal point
/// * upper - Use `E` instead of `e` for the exponent sign
#[inline]
#[experimental = "may be removed or relocated"]
pub fn to_str_exp_exact(num: f32, dig: uint, upper: bool) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, SignNeg, DigExact(dig), ExpDec, upper);
r
}
/// Converts a float to a string using the exponential notation with the maximum number of
/// digits after the decimal point in the significand
///
/// # Arguments
///
/// * num - The float value
/// * digits - The number of digits after the decimal point
/// * upper - Use `E` instead of `e` for the exponent sign
#[inline]
#[experimental = "may be removed or relocated"]
pub fn to_str_exp_digits(num: f32, dig: uint, upper: bool) -> String {
let (r, _) = strconv::float_to_str_common(
num, 10u, true, SignNeg, DigMax(dig), ExpDec, upper);
r
}
#[cfg(test)]
mod tests {
use f32::*;
use num::*;
use num::FpCategory as Fp;
#[test]
fn test_min_nan() {
assert_eq!(NAN.min(2.0), 2.0);
assert_eq!(2.0f32.min(NAN), 2.0);
}
#[test]
fn test_max_nan() {
assert_eq!(NAN.max(2.0), 2.0);
assert_eq!(2.0f32.max(NAN), 2.0);
}
#[test]
fn test_num_f32() {
test_num(10f32, 2f32);
}
#[test]
fn test_floor() {
assert_approx_eq!(1.0f32.floor(), 1.0f32);
assert_approx_eq!(1.3f32.floor(), 1.0f32);
assert_approx_eq!(1.5f32.floor(), 1.0f32);
assert_approx_eq!(1.7f32.floor(), 1.0f32);
assert_approx_eq!(0.0f32.floor(), 0.0f32);
assert_approx_eq!((-0.0f32).floor(), -0.0f32);
assert_approx_eq!((-1.0f32).floor(), -1.0f32);
assert_approx_eq!((-1.3f32).floor(), -2.0f32);
assert_approx_eq!((-1.5f32).floor(), -2.0f32);
assert_approx_eq!((-1.7f32).floor(), -2.0f32);
}
#[test]
fn test_ceil() {
assert_approx_eq!(1.0f32.ceil(), 1.0f32);
assert_approx_eq!(1.3f32.ceil(), 2.0f32);
assert_approx_eq!(1.5f32.ceil(), 2.0f32);
assert_approx_eq!(1.7f32.ceil(), 2.0f32);
assert_approx_eq!(0.0f32.ceil(), 0.0f32);
assert_approx_eq!((-0.0f32).ceil(), -0.0f32);
assert_approx_eq!((-1.0f32).ceil(), -1.0f32);
assert_approx_eq!((-1.3f32).ceil(), -1.0f32);
assert_approx_eq!((-1.5f32).ceil(), -1.0f32);
assert_approx_eq!((-1.7f32).ceil(), -1.0f32);
}
#[test]
fn test_round() {
assert_approx_eq!(1.0f32.round(), 1.0f32);
assert_approx_eq!(1.3f32.round(), 1.0f32);
assert_approx_eq!(1.5f32.round(), 2.0f32);
assert_approx_eq!(1.7f32.round(), 2.0f32);
assert_approx_eq!(0.0f32.round(), 0.0f32);
assert_approx_eq!((-0.0f32).round(), -0.0f32);
assert_approx_eq!((-1.0f32).round(), -1.0f32);
assert_approx_eq!((-1.3f32).round(), -1.0f32);
assert_approx_eq!((-1.5f32).round(), -2.0f32);
assert_approx_eq!((-1.7f32).round(), -2.0f32);
}
#[test]
fn test_trunc() {
assert_approx_eq!(1.0f32.trunc(), 1.0f32);
assert_approx_eq!(1.3f32.trunc(), 1.0f32);
assert_approx_eq!(1.5f32.trunc(), 1.0f32);
assert_approx_eq!(1.7f32.trunc(), 1.0f32);
assert_approx_eq!(0.0f32.trunc(), 0.0f32);
assert_approx_eq!((-0.0f32).trunc(), -0.0f32);
assert_approx_eq!((-1.0f32).trunc(), -1.0f32);
assert_approx_eq!((-1.3f32).trunc(), -1.0f32);
assert_approx_eq!((-1.5f32).trunc(), -1.0f32);
assert_approx_eq!((-1.7f32).trunc(), -1.0f32);
}
#[test]
fn test_fract() {
assert_approx_eq!(1.0f32.fract(), 0.0f32);
assert_approx_eq!(1.3f32.fract(), 0.3f32);
assert_approx_eq!(1.5f32.fract(), 0.5f32);
assert_approx_eq!(1.7f32.fract(), 0.7f32);
assert_approx_eq!(0.0f32.fract(), 0.0f32);
assert_approx_eq!((-0.0f32).fract(), -0.0f32);
assert_approx_eq!((-1.0f32).fract(), -0.0f32);
assert_approx_eq!((-1.3f32).fract(), -0.3f32);
assert_approx_eq!((-1.5f32).fract(), -0.5f32);
assert_approx_eq!((-1.7f32).fract(), -0.7f32);
}
#[test]
fn test_asinh() {
assert_eq!(0.0f32.asinh(), 0.0f32);
assert_eq!((-0.0f32).asinh(), -0.0f32);
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let nan: f32 = Float::nan();
assert_eq!(inf.asinh(), inf);
assert_eq!(neg_inf.asinh(), neg_inf);
assert!(nan.asinh().is_nan());
assert_approx_eq!(2.0f32.asinh(), 1.443635475178810342493276740273105f32);
assert_approx_eq!((-2.0f32).asinh(), -1.443635475178810342493276740273105f32);
}
#[test]
fn test_acosh() {
assert_eq!(1.0f32.acosh(), 0.0f32);
assert!(0.999f32.acosh().is_nan());
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let nan: f32 = Float::nan();
assert_eq!(inf.acosh(), inf);
assert!(neg_inf.acosh().is_nan());
assert!(nan.acosh().is_nan());
assert_approx_eq!(2.0f32.acosh(), 1.31695789692481670862504634730796844f32);
assert_approx_eq!(3.0f32.acosh(), 1.76274717403908605046521864995958461f32);
}
#[test]
fn test_atanh() {
assert_eq!(0.0f32.atanh(), 0.0f32);
assert_eq!((-0.0f32).atanh(), -0.0f32);
let inf32: f32 = Float::infinity();
let neg_inf32: f32 = Float::neg_infinity();
assert_eq!(1.0f32.atanh(), inf32);
assert_eq!((-1.0f32).atanh(), neg_inf32);
assert!(2f64.atanh().atanh().is_nan());
assert!((-2f64).atanh().atanh().is_nan());
let inf64: f32 = Float::infinity();
let neg_inf64: f32 = Float::neg_infinity();
let nan32: f32 = Float::nan();
assert!(inf64.atanh().is_nan());
assert!(neg_inf64.atanh().is_nan());
assert!(nan32.atanh().is_nan());
assert_approx_eq!(0.5f32.atanh(), 0.54930614433405484569762261846126285f32);
assert_approx_eq!((-0.5f32).atanh(), -0.54930614433405484569762261846126285f32);
}
#[test]
fn test_real_consts() {
use super::consts;
let pi: f32 = consts::PI;
let two_pi: f32 = consts::PI_2;
let frac_pi_2: f32 = consts::FRAC_PI_2;
let frac_pi_3: f32 = consts::FRAC_PI_3;
let frac_pi_4: f32 = consts::FRAC_PI_4;
let frac_pi_6: f32 = consts::FRAC_PI_6;
let frac_pi_8: f32 = consts::FRAC_PI_8;
let frac_1_pi: f32 = consts::FRAC_1_PI;
let frac_2_pi: f32 = consts::FRAC_2_PI;
let frac_2_sqrtpi: f32 = consts::FRAC_2_SQRTPI;
let sqrt2: f32 = consts::SQRT2;
let frac_1_sqrt2: f32 = consts::FRAC_1_SQRT2;
let e: f32 = consts::E;
let log2_e: f32 = consts::LOG2_E;
let log10_e: f32 = consts::LOG10_E;
let ln_2: f32 = consts::LN_2;
let ln_10: f32 = consts::LN_10;
assert_approx_eq!(two_pi, 2f32 * pi);
assert_approx_eq!(frac_pi_2, pi / 2f32);
assert_approx_eq!(frac_pi_3, pi / 3f32);
assert_approx_eq!(frac_pi_4, pi / 4f32);
assert_approx_eq!(frac_pi_6, pi / 6f32);
assert_approx_eq!(frac_pi_8, pi / 8f32);
assert_approx_eq!(frac_1_pi, 1f32 / pi);
assert_approx_eq!(frac_2_pi, 2f32 / pi);
assert_approx_eq!(frac_2_sqrtpi, 2f32 / pi.sqrt());
assert_approx_eq!(sqrt2, 2f32.sqrt());
assert_approx_eq!(frac_1_sqrt2, 1f32 / 2f32.sqrt());
assert_approx_eq!(log2_e, e.log2());
assert_approx_eq!(log10_e, e.log10());
assert_approx_eq!(ln_2, 2f32.ln());
assert_approx_eq!(ln_10, 10f32.ln());
}
#[test]
pub fn test_abs() {
assert_eq!(INFINITY.abs(), INFINITY);
assert_eq!(1f32.abs(), 1f32);
assert_eq!(0f32.abs(), 0f32);
assert_eq!((-0f32).abs(), 0f32);
assert_eq!((-1f32).abs(), 1f32);
assert_eq!(NEG_INFINITY.abs(), INFINITY);
assert_eq!((1f32/NEG_INFINITY).abs(), 0f32);
assert!(NAN.abs().is_nan());
}
#[test]
fn test_abs_sub() {
assert_eq!((-1f32).abs_sub(1f32), 0f32);
assert_eq!(1f32.abs_sub(1f32), 0f32);
assert_eq!(1f32.abs_sub(0f32), 1f32);
assert_eq!(1f32.abs_sub(-1f32), 2f32);
assert_eq!(NEG_INFINITY.abs_sub(0f32), 0f32);
assert_eq!(INFINITY.abs_sub(1f32), INFINITY);
assert_eq!(0f32.abs_sub(NEG_INFINITY), INFINITY);
assert_eq!(0f32.abs_sub(INFINITY), 0f32);
}
#[test]
fn test_abs_sub_nowin() {
assert!(NAN.abs_sub(-1f32).is_nan());
assert!(1f32.abs_sub(NAN).is_nan());
}
#[test]
fn test_signum() {
assert_eq!(INFINITY.signum(), 1f32);
assert_eq!(1f32.signum(), 1f32);
assert_eq!(0f32.signum(), 1f32);
assert_eq!((-0f32).signum(), -1f32);
assert_eq!((-1f32).signum(), -1f32);
assert_eq!(NEG_INFINITY.signum(), -1f32);
assert_eq!((1f32/NEG_INFINITY).signum(), -1f32);
assert!(NAN.signum().is_nan());
}
#[test]
fn test_is_positive() {
assert!(INFINITY.is_positive());
assert!(1f32.is_positive());
assert!(0f32.is_positive());
assert!(!(-0f32).is_positive());
assert!(!(-1f32).is_positive());
assert!(!NEG_INFINITY.is_positive());
assert!(!(1f32/NEG_INFINITY).is_positive());
assert!(!NAN.is_positive());
}
#[test]
fn test_is_negative() {
assert!(!INFINITY.is_negative());
assert!(!1f32.is_negative());
assert!(!0f32.is_negative());
assert!((-0f32).is_negative());
assert!((-1f32).is_negative());
assert!(NEG_INFINITY.is_negative());
assert!((1f32/NEG_INFINITY).is_negative());
assert!(!NAN.is_negative());
}
#[test]
fn test_is_normal() {
let nan: f32 = Float::nan();
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let zero: f32 = Float::zero();
let neg_zero: f32 = Float::neg_zero();
assert!(!nan.is_normal());
assert!(!inf.is_normal());
assert!(!neg_inf.is_normal());
assert!(!zero.is_normal());
assert!(!neg_zero.is_normal());
assert!(1f32.is_normal());
assert!(1e-37f32.is_normal());
assert!(!1e-38f32.is_normal());
}
#[test]
fn test_classify() {
let nan: f32 = Float::nan();
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let zero: f32 = Float::zero();
let neg_zero: f32 = Float::neg_zero();
assert_eq!(nan.classify(), Fp::Nan);
assert_eq!(inf.classify(), Fp::Infinite);
assert_eq!(neg_inf.classify(), Fp::Infinite);
assert_eq!(zero.classify(), Fp::Zero);
assert_eq!(neg_zero.classify(), Fp::Zero);
assert_eq!(1f32.classify(), Fp::Normal);
assert_eq!(1e-37f32.classify(), Fp::Normal);
assert_eq!(1e-38f32.classify(), Fp::Subnormal);
}
#[test]
fn test_ldexp() {
// We have to use from_str until base-2 exponents
// are supported in floating-point literals
let f1: f32 = FromStrRadix::from_str_radix("1p-123", 16).unwrap();
let f2: f32 = FromStrRadix::from_str_radix("1p-111", 16).unwrap();
assert_eq!(Float::ldexp(1f32, -123), f1);
assert_eq!(Float::ldexp(1f32, -111), f2);
assert_eq!(Float::ldexp(0f32, -123), 0f32);
assert_eq!(Float::ldexp(-0f32, -123), -0f32);
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let nan: f32 = Float::nan();
assert_eq!(Float::ldexp(inf, -123), inf);
assert_eq!(Float::ldexp(neg_inf, -123), neg_inf);
assert!(Float::ldexp(nan, -123).is_nan());
}
#[test]
fn test_frexp() {
// We have to use from_str until base-2 exponents
// are supported in floating-point literals
let f1: f32 = FromStrRadix::from_str_radix("1p-123", 16).unwrap();
let f2: f32 = FromStrRadix::from_str_radix("1p-111", 16).unwrap();
let (x1, exp1) = f1.frexp();
let (x2, exp2) = f2.frexp();
assert_eq!((x1, exp1), (0.5f32, -122));
assert_eq!((x2, exp2), (0.5f32, -110));
assert_eq!(Float::ldexp(x1, exp1), f1);
assert_eq!(Float::ldexp(x2, exp2), f2);
assert_eq!(0f32.frexp(), (0f32, 0));
assert_eq!((-0f32).frexp(), (-0f32, 0));
}
#[test] #[cfg_attr(windows, ignore)] // FIXME #8755
fn test_frexp_nowin() {
let inf: f32 = Float::infinity();
let neg_inf: f32 = Float::neg_infinity();
let nan: f32 = Float::nan();
assert_eq!(match inf.frexp() { (x, _) => x }, inf);
assert_eq!(match neg_inf.frexp() { (x, _) => x }, neg_inf);
assert!(match nan.frexp() { (x, _) => x.is_nan() })
}
#[test]
fn test_integer_decode() {
assert_eq!(3.14159265359f32.integer_decode(), (13176795u64, -22i16, 1i8));
assert_eq!((-8573.5918555f32).integer_decode(), (8779358u64, -10i16, -1i8));
assert_eq!(2f32.powf(100.0).integer_decode(), (8388608u64, 77i16, 1i8));
assert_eq!(0f32.integer_decode(), (0u64, -150i16, 1i8));
assert_eq!((-0f32).integer_decode(), (0u64, -150i16, -1i8));
assert_eq!(INFINITY.integer_decode(), (8388608u64, 105i16, 1i8));
assert_eq!(NEG_INFINITY.integer_decode(), (8388608u64, 105i16, -1i8));
assert_eq!(NAN.integer_decode(), (12582912u64, 105i16, 1i8));
}
#[test]
fn test_sqrt_domain() {
assert!(NAN.sqrt().is_nan());
assert!(NEG_INFINITY.sqrt().is_nan());
assert!((-1.0f32).sqrt().is_nan());
assert_eq!((-0.0f32).sqrt(), -0.0);
assert_eq!(0.0f32.sqrt(), 0.0);
assert_eq!(1.0f32.sqrt(), 1.0);
assert_eq!(INFINITY.sqrt(), INFINITY);
}
}