src/libstd/sys/wasm/cmath.rs

// Copyright 2017 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.

#[inline]
pub unsafe fn cbrtf(n: f32) -> f32 {
    f64::cbrt(n as f64) as f32
}

#[inline]
pub unsafe fn expm1f(n: f32) -> f32 {
    f64::exp_m1(n as f64) as f32
}

#[inline]
#[allow(deprecated)]
pub unsafe fn fdimf(a: f32, b: f32) -> f32 {
    f64::abs_sub(a as f64, b as f64) as f32
}

#[inline]
pub unsafe fn log1pf(n: f32) -> f32 {
    f64::ln_1p(n as f64) as f32
}

#[inline]
pub unsafe fn hypotf(x: f32, y: f32) -> f32 {
    f64::hypot(x as f64, y as f64) as f32
}

#[inline]
pub unsafe fn acosf(n: f32) -> f32 {
    f64::acos(n as f64) as f32
}

#[inline]
pub unsafe fn asinf(n: f32) -> f32 {
    f64::asin(n as f64) as f32
}

#[inline]
pub unsafe fn atan2f(n: f32, b: f32) -> f32 {
    f64::atan2(n as f64, b as f64) as f32
}

#[inline]
pub unsafe fn atanf(n: f32) -> f32 {
    f64::atan(n as f64) as f32
}

#[inline]
pub unsafe fn coshf(n: f32) -> f32 {
    f64::cosh(n as f64) as f32
}

#[inline]
pub unsafe fn sinhf(n: f32) -> f32 {
    f64::sinh(n as f64) as f32
}

#[inline]
pub unsafe fn tanf(n: f32) -> f32 {
    f64::tan(n as f64) as f32
}

#[inline]
pub unsafe fn tanhf(n: f32) -> f32 {
    f64::tanh(n as f64) as f32
}

// Right now all these functions, the f64 version of the functions above, all
// shell out to random names. These names aren't actually defined anywhere, per
// se, but we need this to compile somehow.
//
// The idea with this is that when you're using wasm then, for now, we have no
// way of providing an implementation of these which delegates to a "correct"
// implementation. For example most wasm applications probably just want to
// delegate to the javascript `Math` object and its related functions, but wasm
// doesn't currently have the ability to seamlessly do that (when you
// instantiate a module you have to set that up).
//
// As a result these are just defined here with "hopefully helpful" names. The
// symbols won't ever be needed or show up unless these functions are called,
// and hopefully when they're called the errors are self-explanatory enough to
// figure out what's going on.

extern {
    #[link_name = "Math_acos"]
    pub fn acos(n: f64) -> f64;
    #[link_name = "Math_asin"]
    pub fn asin(n: f64) -> f64;
    #[link_name = "Math_atan"]
    pub fn atan(n: f64) -> f64;
    #[link_name = "Math_atan2"]
    pub fn atan2(a: f64, b: f64) -> f64;
    #[link_name = "Math_cbrt"]
    pub fn cbrt(n: f64) -> f64;
    #[link_name = "Math_cosh"]
    pub fn cosh(n: f64) -> f64;
    #[link_name = "Math_expm1"]
    pub fn expm1(n: f64) -> f64;
    pub fn fdim(a: f64, b: f64) -> f64;
    #[link_name = "Math_log1p"]
    pub fn log1p(n: f64) -> f64;
    #[link_name = "Math_sinh"]
    pub fn sinh(n: f64) -> f64;
    #[link_name = "Math_tan"]
    pub fn tan(n: f64) -> f64;
    #[link_name = "Math_tanh"]
    pub fn tanh(n: f64) -> f64;
    #[link_name = "Math_hypot"]
    pub fn hypot(x: f64, y: f64) -> f64;
}