Add benchmark suite

Signed-off-by: Benjamin Schultzer <benjamin@schultzer.com>

library/compiler-builtins/libm/Cargo.toml

@@ -30,6 +30,8 @@ members = [
 
 [dev-dependencies]
 no-panic = "0.1.8"
+rand = "0.6.5"
+paste = "0.1.5"
 
 [build-dependencies]
 rand = { version = "0.6.5", optional = true }

library/compiler-builtins/libm/README.md

@@ -37,6 +37,12 @@ fn foo(x: f32) {
 
 The API documentation can be found [here](https://docs.rs/libm).
 
+## Benchmark
+[benchmark]: #benchmark
+Run `cargo +nightly bench`
+
+NOTE: remember to have nightly installed `rustup install nightly`
+
 ## Contributing
 
 Please check [CONTRIBUTING.md](CONTRIBUTING.md)

library/compiler-builtins/libm/azure-pipelines.yml

@@ -71,3 +71,14 @@ jobs:
       - template: ci/azure-install-rust.yml
       - bash: cargo build -p cb
         displayName: "Check compiler-builtins still probably builds"
+
+  - job: benchmarks
+    pool:
+      vmImage: ubuntu-16.04
+    steps:
+      - template: ci/azure-install-rust.yml
+      - bash: cargo bench
+        displayName: "Benchmarks"
+    variables:
+      TOOLCHAIN: nightly
+

library/compiler-builtins/libm/benches/bench.rs

@@ -0,0 +1,118 @@
+#![feature(test)]
+
+extern crate paste;
+extern crate rand;
+extern crate test;
+
+use rand::Rng;
+use test::Bencher;
+
+macro_rules! unary {
+  ($($func:ident),*) => ($(
+      paste::item! {
+        #[bench]
+        pub fn [<$func>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let x = rng.gen::<f64>();
+            bh.iter(|| test::black_box(libm::[<$func>](x)))
+        }
+        #[bench]
+        pub fn [<$func f>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let x = rng.gen::<f32>();
+            bh.iter(|| test::black_box(libm::[<$func f>](x)))
+        }
+    }
+  )*);
+}
+macro_rules! binary {
+  ($($func:ident),*) => ($(
+      paste::item! {
+        #[bench]
+        pub fn [<$func>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let x = rng.gen::<f64>();
+            let y = rng.gen::<f64>();
+            bh.iter(|| test::black_box(libm::[<$func>](x, y)))
+        }
+        #[bench]
+        pub fn [<$func f>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let x = rng.gen::<f32>();
+            let y = rng.gen::<f32>();
+            bh.iter(|| test::black_box(libm::[<$func f>](x, y)))
+        }
+    }
+  )*);
+  ($($func:ident);*) => ($(
+      paste::item! {
+        #[bench]
+        pub fn [<$func>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let x = rng.gen::<f64>();
+            let n = rng.gen::<i32>();
+            bh.iter(|| test::black_box(libm::[<$func>](x, n)))
+        }
+        #[bench]
+        pub fn [<$func f>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let x = rng.gen::<f32>();
+            let n = rng.gen::<i32>();
+            bh.iter(|| test::black_box(libm::[<$func f>](x, n)))
+        }
+    }
+  )*);
+}
+macro_rules! trinary {
+  ($($func:ident),*) => ($(
+      paste::item! {
+        #[bench]
+        pub fn [<$func>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let x = rng.gen::<f64>();
+            let y = rng.gen::<f64>();
+            let z = rng.gen::<f64>();
+            bh.iter(|| test::black_box(libm::[<$func>](x, y, z)))
+        }
+        #[bench]
+        pub fn [<$func f>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let x = rng.gen::<f32>();
+            let y = rng.gen::<f32>();
+            let z = rng.gen::<f32>();
+            bh.iter(|| test::black_box(libm::[<$func f>](x, y, z)))
+        }
+    }
+  )*);
+}
+macro_rules! bessel {
+  ($($func:ident),*) => ($(
+      paste::item! {
+        #[bench]
+        pub fn [<$func>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let mut n = rng.gen::<i32>();
+            n &= 0xffff;
+            let x = rng.gen::<f64>();
+            bh.iter(|| test::black_box(libm::[<$func>](n, x)))
+        }
+        #[bench]
+        pub fn [<$func f>](bh: &mut Bencher) {
+            let mut rng = rand::thread_rng();
+            let mut n = rng.gen::<i32>();
+            n &= 0xffff;
+            let x = rng.gen::<f32>();
+            bh.iter(|| test::black_box(libm::[<$func f>](n, x)))
+        }
+    }
+  )*);
+}
+
+unary!(
+    acos, acosh, asin, atan, cbrt, ceil, cos, cosh, erf, exp, exp2, exp10, expm1, fabs, floor, j0,
+    j1, lgamma, log, log1p, log2, log10, round, sin, sinh, sqrt, tan, tanh, tgamma, trunc, y0, y1
+);
+binary!(atan2, copysign, fdim, fmax, fmin, fmod, hypot, pow);
+trinary!(fma);
+bessel!(jn, yn);
+binary!(ldexp; scalbn);

library/compiler-builtins/libm/src/math/pow.rs

@@ -479,7 +479,7 @@ mod tests {
             .for_each(|s| s.iter().for_each(|val| pow_test(base, *val, expected)));
     }
 
-    fn test_sets(sets: &[&[f64]], computed: &Fn(f64) -> f64, expected: &Fn(f64) -> f64) {
+    fn test_sets(sets: &[&[f64]], computed: &dyn Fn(f64) -> f64, expected: &dyn Fn(f64) -> f64) {
         sets.iter().for_each(|s| {
             s.iter().for_each(|val| {
                 let exp = expected(*val);