add libm support

demo/src/main.rs

@@ -29,6 +29,11 @@ fn test_result<T>(result: Result<(), T>) -> &'static str {
 
 fn main() {
 	println!("Test {} ... {}", stringify!(hello), test_result(hello()));
+	println!(
+		"Test {} ... {}",
+		stringify!(arithmetic),
+		test_result(arithmetic())
+	);
 	println!(
 		"Test {} ... {}",
 		stringify!(print_argv),

demo/src/tests/mod.rs

@@ -1,7 +1,7 @@
 use core::arch::x86_64 as arch;
 use rand::prelude::*;
 use std::env;
-use std::f64::consts::PI;
+use std::f64::consts::{E, PI};
 use std::fs::File;
 use std::io::Read;
 use std::io::Write;
@@ -275,6 +275,18 @@ pub fn hello() -> Result<(), ()> {
 		"Crab emoji: {}",
 		String::from_utf8(crab).unwrap_or_default()
 	);
+
+	Ok(())
+}
+
+pub fn arithmetic() -> Result<(), ()> {
+	let mut rng = rand::thread_rng();
+	let x = rng.gen::<f64>();
+	let y: f64 = x.exp();
+	let z: f64 = y.log(E);
+
+	println!("x = {}, e^x = {}, ln(e^x) = {}", x, y, z);
+
 	Ok(())
 }
 

hermit-sys/Cargo.toml

@@ -25,6 +25,7 @@ walkdir = "2"
 [dependencies]
 log = { version = "0.4", default-features = false }
 lazy_static = "1.4.0"
+libm = { version = "0.2.1", default-features = false }
 
 [target.'cfg(target_arch = "x86_64")'.dependencies.x86]
 version = "0.*"

hermit-sys/src/cmath.rs

@@ -0,0 +1,201 @@
+#![allow(dead_code)]
+
+#[no_mangle]
+pub extern "C" fn acos(n: f64) -> f64 {
+	libm::acos(n)
+}
+
+#[no_mangle]
+pub extern "C" fn acosf(n: f32) -> f32 {
+	libm::acosf(n)
+}
+
+#[no_mangle]
+pub extern "C" fn acosh(x: f64) -> f64 {
+	libm::acosh(x)
+}
+
+#[no_mangle]
+pub extern "C" fn acoshf(x: f32) -> f32 {
+	libm::acoshf(x)
+}
+
+#[no_mangle]
+pub extern "C" fn asin(n: f64) -> f64 {
+	libm::asin(n)
+}
+
+#[no_mangle]
+pub extern "C" fn asinf(n: f32) -> f32 {
+	libm::asinf(n)
+}
+
+#[no_mangle]
+pub extern "C" fn asinh(x: f64) -> f64 {
+	libm::asinh(x)
+}
+
+#[no_mangle]
+pub extern "C" fn asinhf(x: f32) -> f32 {
+	libm::asinhf(x)
+}
+
+#[no_mangle]
+pub extern "C" fn atan(n: f64) -> f64 {
+	libm::atan(n)
+}
+
+#[no_mangle]
+pub extern "C" fn atan2(a: f64, b: f64) -> f64 {
+	libm::atan2(a, b)
+}
+
+#[no_mangle]
+pub extern "C" fn atan2f(a: f32, b: f32) -> f32 {
+	libm::atan2f(a, b)
+}
+
+#[no_mangle]
+pub extern "C" fn atanf(n: f32) -> f32 {
+	libm::atanf(n)
+}
+
+#[no_mangle]
+pub extern "C" fn cbrt(n: f64) -> f64 {
+	libm::cbrt(n)
+}
+
+#[no_mangle]
+pub extern "C" fn cbrtf(n: f32) -> f32 {
+	libm::cbrtf(n)
+}
+
+#[no_mangle]
+pub extern "C" fn ceil(x: f64) -> f64 {
+	libm::ceil(x)
+}
+
+#[no_mangle]
+pub extern "C" fn ceilf(x: f32) -> f32 {
+	libm::ceilf(x)
+}
+
+#[no_mangle]
+pub extern "C" fn cos(x: f64) -> f64 {
+	libm::cos(x)
+}
+
+#[no_mangle]
+pub extern "C" fn cosf(x: f32) -> f32 {
+	libm::cosf(x)
+}
+
+#[no_mangle]
+pub extern "C" fn cosh(x: f64) -> f64 {
+	libm::cosh(x)
+}
+
+#[no_mangle]
+pub extern "C" fn coshf(x: f32) -> f32 {
+	libm::coshf(x)
+}
+
+#[no_mangle]
+pub extern "C" fn exp(x: f64) -> f64 {
+	libm::exp(x)
+}
+
+#[no_mangle]
+pub extern "C" fn expf(x: f32) -> f32 {
+	libm::expf(x)
+}
+
+#[no_mangle]
+pub extern "C" fn expm1(n: f64) -> f64 {
+	libm::expm1(n)
+}
+
+#[no_mangle]
+pub extern "C" fn expm1f(n: f32) -> f32 {
+	libm::expm1f(n)
+}
+
+#[no_mangle]
+pub extern "C" fn fdim(a: f64, b: f64) -> f64 {
+	libm::fdim(a, b)
+}
+
+#[no_mangle]
+pub extern "C" fn fdimf(a: f32, b: f32) -> f32 {
+	libm::fdimf(a, b)
+}
+
+#[no_mangle]
+pub extern "C" fn hypot(x: f64, y: f64) -> f64 {
+	libm::hypot(x, y)
+}
+
+#[no_mangle]
+pub extern "C" fn hypotf(x: f32, y: f32) -> f32 {
+	libm::hypotf(x, y)
+}
+
+#[no_mangle]
+pub extern "C" fn log(x: f64) -> f64 {
+	libm::log(x)
+}
+
+#[no_mangle]
+pub extern "C" fn logf(x: f32) -> f32 {
+	libm::logf(x)
+}
+
+#[no_mangle]
+pub extern "C" fn log1p(n: f64) -> f64 {
+	libm::log1p(n)
+}
+
+#[no_mangle]
+pub extern "C" fn log1pf(n: f32) -> f32 {
+	libm::log1pf(n)
+}
+
+#[no_mangle]
+pub extern "C" fn sinh(n: f64) -> f64 {
+	libm::sinh(n)
+}
+
+#[no_mangle]
+pub extern "C" fn sinhf(n: f32) -> f32 {
+	libm::sinhf(n)
+}
+
+#[no_mangle]
+pub extern "C" fn sqrt(x: f64) -> f64 {
+	libm::sqrt(x)
+}
+
+#[no_mangle]
+pub extern "C" fn sqrtf(x: f32) -> f32 {
+	libm::sqrtf(x)
+}
+
+#[no_mangle]
+pub extern "C" fn tan(n: f64) -> f64 {
+	libm::tan(n)
+}
+
+#[no_mangle]
+pub extern "C" fn tanf(n: f32) -> f32 {
+	libm::tanf(n)
+}
+
+#[no_mangle]
+pub extern "C" fn tanh(n: f64) -> f64 {
+	libm::tanh(n)
+}
+
+#[no_mangle]
+pub extern "C" fn tanhf(n: f32) -> f32 {
+	libm::tanhf(n)
+}

hermit-sys/src/lib.rs

@@ -6,7 +6,9 @@ extern crate smoltcp;
 extern crate x86;
 #[macro_use]
 extern crate lazy_static;
+extern crate libm;
 
+mod cmath;
 #[cfg(not(feature = "smoltcp"))]
 mod dummy;
 #[cfg(feature = "smoltcp")]