diff --git a/library/compiler-builtins/libm/.gitignore b/library/compiler-builtins/libm/.gitignore
index 6db0ab6effc4..39950911a624 100644
--- a/library/compiler-builtins/libm/.gitignore
+++ b/library/compiler-builtins/libm/.gitignore
@@ -1,5 +1,8 @@
 **/*.rs.bk
 .#*
+/bin
+/math/src
+/math/target
 /target
 /tests
 Cargo.lock
diff --git a/library/compiler-builtins/libm/.travis.yml b/library/compiler-builtins/libm/.travis.yml
index 922273e0936b..b3beecb09204 100644
--- a/library/compiler-builtins/libm/.travis.yml
+++ b/library/compiler-builtins/libm/.travis.yml
@@ -5,21 +5,29 @@ sudo: required
 matrix:
   include:
     - env: TARGET=aarch64-unknown-linux-gnu
-    - env: TARGET=armv7-unknown-linux-gnueabihf
-    - env: TARGET=i686-unknown-linux-gnu
-    - env: TARGET=mips-unknown-linux-gnu
-    - env: TARGET=mips64-unknown-linux-gnuabi64
-    - env: TARGET=mips64el-unknown-linux-gnuabi64
-    - env: TARGET=mipsel-unknown-linux-gnu
-    - env: TARGET=powerpc-unknown-linux-gnu
-    - env: TARGET=powerpc64-unknown-linux-gnu
-    - env: TARGET=powerpc64le-unknown-linux-gnu
-    - env: TARGET=x86_64-unknown-linux-gnu
-    - env: TARGET=cargo-fmt
-      rust: beta
-      # no-panic link test
-    - env: TARGET=armv7-unknown-linux-gnueabihf
       rust: nightly
+    # - env: TARGET=armv7-unknown-linux-gnueabihf
+    #   rust: nightly
+    # - env: TARGET=i686-unknown-linux-gnu
+    #   rust: nightly
+    # - env: TARGET=mips-unknown-linux-gnu
+    #   rust: nightly
+    # - env: TARGET=mips64-unknown-linux-gnuabi64
+    #   rust: nightly
+    # - env: TARGET=mips64el-unknown-linux-gnuabi64
+    #   rust: nightly
+    # - env: TARGET=mipsel-unknown-linux-gnu
+    #   rust: nightly
+    # - env: TARGET=powerpc-unknown-linux-gnu
+    #   rust: nightly
+    # - env: TARGET=powerpc64-unknown-linux-gnu
+    #   rust: nightly
+    # - env: TARGET=powerpc64le-unknown-linux-gnu
+    #   rust: nightly
+    - env: TARGET=x86_64-unknown-linux-gnu
+      rust: nightly
+    # - env: TARGET=cargo-fmt
+    #   rust: beta
 
 before_install: set -e
 
@@ -27,6 +35,7 @@ install:
   - bash ci/install.sh
 
 script:
+  - export PATH=$HOME/.local/bin:$PATH
   - bash ci/script.sh
 
 after_script: set +e
diff --git a/library/compiler-builtins/libm/Cargo.toml b/library/compiler-builtins/libm/Cargo.toml
index 8a2ba7447ab6..cedf8d267db8 100644
--- a/library/compiler-builtins/libm/Cargo.toml
+++ b/library/compiler-builtins/libm/Cargo.toml
@@ -14,4 +14,13 @@ version = "0.1.2"
 checked = []
 
 [workspace]
-members = ["cb", "test-generator"]
\ No newline at end of file
+members = [
+  "cb",
+  "input-generator",
+  "musl-generator",
+  "newlib-generator",
+  "shared",
+]
+
+[dev-dependencies]
+shared = { path = "shared" }
diff --git a/library/compiler-builtins/libm/ci/install.sh b/library/compiler-builtins/libm/ci/install.sh
index 4d9552d231bc..7f73c5feaf36 100644
--- a/library/compiler-builtins/libm/ci/install.sh
+++ b/library/compiler-builtins/libm/ci/install.sh
@@ -15,6 +15,9 @@ main() {
     if [ $TARGET != x86_64-unknown-linux-gnu ]; then
         rustup target add $TARGET
     fi
+
+    mkdir -p ~/.local/bin
+    curl -L https://github.com/japaric/qemu-bin/raw/master/14.04/qemu-arm-2.12.0 > ~/.local/bin/qemu-arm
 }
 
 main
diff --git a/library/compiler-builtins/libm/ci/script.sh b/library/compiler-builtins/libm/ci/script.sh
index bb19e23d84e0..59e5a5f37de9 100644
--- a/library/compiler-builtins/libm/ci/script.sh
+++ b/library/compiler-builtins/libm/ci/script.sh
@@ -7,10 +7,11 @@ main() {
     fi
 
     # test that the functions don't contain invocations of `panic!`
-    if [ $TRAVIS_RUST_VERSION = nightly ]; then
-        cross build --release --target $TARGET --example no-panic
-        return
-    fi
+    case $TARGET in
+        armv7-unknown-linux-gnueabihf)
+            cross build --release --target $TARGET --example no-panic
+            ;;
+    esac
 
     # quick check
     cargo check
@@ -18,12 +19,14 @@ main() {
     # check that we can source import libm into compiler-builtins
     cargo check --package cb
 
+    # generate tests
+    cargo run -p input-generator --target x86_64-unknown-linux-musl
+    cargo run -p musl-generator --target x86_64-unknown-linux-musl
+    cargo run -p newlib-generator
+
     # run unit tests
     cross test --lib --features checked --target $TARGET --release
 
-    # generate tests
-    cargo run --package test-generator --target x86_64-unknown-linux-musl
-
     # run generated tests
     cross test --tests --features checked --target $TARGET --release
 
diff --git a/library/compiler-builtins/libm/test-generator/Cargo.toml b/library/compiler-builtins/libm/input-generator/Cargo.toml
similarity index 55%
rename from library/compiler-builtins/libm/test-generator/Cargo.toml
rename to library/compiler-builtins/libm/input-generator/Cargo.toml
index b810d9daf630..fef2558a8b09 100644
--- a/library/compiler-builtins/libm/test-generator/Cargo.toml
+++ b/library/compiler-builtins/libm/input-generator/Cargo.toml
@@ -1,9 +1,7 @@
 [package]
-name = "test-generator"
+name = "input-generator"
 version = "0.1.0"
 authors = ["Jorge Aparicio <jorge@japaric.io>"]
-publish = false
 
 [dependencies]
-rand = "0.5.3"
-itertools = "0.7.8"
+rand = "0.5.4"
diff --git a/library/compiler-builtins/libm/input-generator/src/main.rs b/library/compiler-builtins/libm/input-generator/src/main.rs
new file mode 100644
index 000000000000..b4a6ad142258
--- /dev/null
+++ b/library/compiler-builtins/libm/input-generator/src/main.rs
@@ -0,0 +1,189 @@
+extern crate rand;
+
+use std::collections::BTreeSet;
+use std::error::Error;
+use std::fs::{self, File};
+use std::io::Write;
+
+use rand::{RngCore, SeedableRng, XorShiftRng};
+
+const NTESTS: usize = 10_000;
+
+fn main() -> Result<(), Box<Error>> {
+    let mut rng = XorShiftRng::from_rng(&mut rand::thread_rng())?;
+
+    fs::remove_dir_all("bin").ok();
+    fs::create_dir_all("bin/input")?;
+    fs::create_dir_all("bin/output")?;
+
+    f32(&mut rng)?;
+    f32f32(&mut rng)?;
+    f32f32f32(&mut rng)?;
+    f32i16(&mut rng)?;
+    f64(&mut rng)?;
+    f64f64(&mut rng)?;
+    f64f64f64(&mut rng)?;
+    f64i16(&mut rng)?;
+
+    Ok(())
+}
+
+fn f32(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
+    let mut set = BTreeSet::new();
+
+    while set.len() < NTESTS {
+        let f = f32::from_bits(rng.next_u32());
+
+        if f.is_nan() {
+            continue;
+        }
+
+        set.insert(f.to_bits());
+    }
+
+    let mut f = File::create("bin/input/f32")?;
+    for i in set {
+        f.write_all(&i.to_bytes())?;
+    }
+
+    Ok(())
+}
+
+fn f32f32(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
+    let mut f = File::create("bin/input/f32f32")?;
+    let mut i = 0;
+    while i < NTESTS {
+        let x0 = f32::from_bits(rng.next_u32());
+        let x1 = f32::from_bits(rng.next_u32());
+
+        if x0.is_nan() || x1.is_nan() {
+            continue;
+        }
+
+        i += 1;
+        f.write_all(&x0.to_bits().to_bytes())?;
+        f.write_all(&x1.to_bits().to_bytes())?;
+    }
+
+    Ok(())
+}
+
+fn f32i16(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
+    let mut f = File::create("bin/input/f32i16")?;
+    let mut i = 0;
+    while i < NTESTS {
+        let x0 = f32::from_bits(rng.next_u32());
+        let x1 = rng.next_u32() as i16;
+
+        if x0.is_nan() {
+            continue;
+        }
+
+        i += 1;
+        f.write_all(&x0.to_bits().to_bytes())?;
+        f.write_all(&x1.to_bytes())?;
+    }
+
+    Ok(())
+}
+
+fn f32f32f32(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
+    let mut f = File::create("bin/input/f32f32f32")?;
+    let mut i = 0;
+    while i < NTESTS {
+        let x0 = f32::from_bits(rng.next_u32());
+        let x1 = f32::from_bits(rng.next_u32());
+        let x2 = f32::from_bits(rng.next_u32());
+
+        if x0.is_nan() || x1.is_nan() || x2.is_nan() {
+            continue;
+        }
+
+        i += 1;
+        f.write_all(&x0.to_bits().to_bytes())?;
+        f.write_all(&x1.to_bits().to_bytes())?;
+        f.write_all(&x2.to_bits().to_bytes())?;
+    }
+
+    Ok(())
+}
+
+fn f64(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
+    let mut set = BTreeSet::new();
+
+    while set.len() < NTESTS {
+        let f = f64::from_bits(rng.next_u64());
+
+        if f.is_nan() {
+            continue;
+        }
+
+        set.insert(f.to_bits());
+    }
+
+    let mut f = File::create("bin/input/f64")?;
+    for i in set {
+        f.write_all(&i.to_bytes())?;
+    }
+
+    Ok(())
+}
+
+fn f64f64(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
+    let mut f = File::create("bin/input/f64f64")?;
+    let mut i = 0;
+    while i < NTESTS {
+        let x0 = f64::from_bits(rng.next_u64());
+        let x1 = f64::from_bits(rng.next_u64());
+
+        if x0.is_nan() || x1.is_nan() {
+            continue;
+        }
+
+        i += 1;
+        f.write_all(&x0.to_bits().to_bytes())?;
+        f.write_all(&x1.to_bits().to_bytes())?;
+    }
+
+    Ok(())
+}
+
+fn f64f64f64(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
+    let mut f = File::create("bin/input/f64f64f64")?;
+    let mut i = 0;
+    while i < NTESTS {
+        let x0 = f64::from_bits(rng.next_u64());
+        let x1 = f64::from_bits(rng.next_u64());
+        let x2 = f64::from_bits(rng.next_u64());
+
+        if x0.is_nan() || x1.is_nan() || x2.is_nan() {
+            continue;
+        }
+
+        i += 1;
+        f.write_all(&x0.to_bits().to_bytes())?;
+        f.write_all(&x1.to_bits().to_bytes())?;
+        f.write_all(&x2.to_bits().to_bytes())?;
+    }
+
+    Ok(())
+}
+
+fn f64i16(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
+    let mut f = File::create("bin/input/f64i16")?;
+    let mut i = 0;
+    while i < NTESTS {
+        let x0 = f64::from_bits(rng.next_u64());
+        let x1 = rng.next_u32() as i16;
+
+        if x0.is_nan() {
+            continue;
+        }
+
+        i += 1;
+        f.write_all(&x0.to_bits().to_bytes())?;
+        f.write_all(&x1.to_bytes())?;
+    }
+
+    Ok(())
+}
diff --git a/library/compiler-builtins/libm/math/.cargo/config b/library/compiler-builtins/libm/math/.cargo/config
new file mode 100644
index 000000000000..be79c453ad69
--- /dev/null
+++ b/library/compiler-builtins/libm/math/.cargo/config
@@ -0,0 +1,11 @@
+[target.thumbv7em-none-eabi]
+rustflags = [
+  "-C", "link-arg=-Wl,-Tlink.x",
+  "-C", "link-arg=-nostartfiles",
+  "-C", "link-arg=-mthumb",
+  "-C", "link-arg=-march=armv7e-m",
+  "-C", "link-arg=-mfloat-abi=soft",
+]
+
+[build]
+target = "thumbv7em-none-eabi"
\ No newline at end of file
diff --git a/library/compiler-builtins/libm/math/Cargo.toml b/library/compiler-builtins/libm/math/Cargo.toml
new file mode 100644
index 000000000000..5bca038a9c3c
--- /dev/null
+++ b/library/compiler-builtins/libm/math/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "math"
+version = "0.0.0"
+
+[dependencies]
+qemu-arm-rt = { git = "https://github.com/japaric/qemu-arm-rt" }
+
+[workspace]
\ No newline at end of file
diff --git a/library/compiler-builtins/libm/math/Cross.toml b/library/compiler-builtins/libm/math/Cross.toml
new file mode 100644
index 000000000000..471770b528b4
--- /dev/null
+++ b/library/compiler-builtins/libm/math/Cross.toml
@@ -0,0 +1,2 @@
+[target.thumbv7em-none-eabi]
+xargo = false
\ No newline at end of file
diff --git a/library/compiler-builtins/libm/musl-generator/Cargo.toml b/library/compiler-builtins/libm/musl-generator/Cargo.toml
new file mode 100644
index 000000000000..0564f3536116
--- /dev/null
+++ b/library/compiler-builtins/libm/musl-generator/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "musl-generator"
+version = "0.1.0"
+authors = ["Jorge Aparicio <jorge@japaric.io>"]
+
+[dependencies]
+lazy_static = "1.0.2"
+shared = { path = "../shared" }
+libm = { path = ".." }
diff --git a/library/compiler-builtins/libm/musl-generator/src/macros.rs b/library/compiler-builtins/libm/musl-generator/src/macros.rs
new file mode 100644
index 000000000000..16ba99d640c6
--- /dev/null
+++ b/library/compiler-builtins/libm/musl-generator/src/macros.rs
@@ -0,0 +1,191 @@
+macro_rules! f32 {
+    ($($fun:ident,)+) => {{
+        $(
+            // check type signature
+            let _: fn(f32) -> f32 = libm::$fun;
+            let mut $fun = File::create(concat!("bin/output/musl.", stringify!($fun)))?;
+        )+
+
+        for x in shared::F32.iter() {
+            $(
+                let y = unsafe {
+                    extern "C" {
+                        fn $fun(_: f32) -> f32;
+                    }
+
+                    $fun(*x)
+                };
+
+                $fun.write_all(&y.to_bits().to_bytes())?;
+            )+
+        }
+    }};
+}
+
+macro_rules! f32f32 {
+    ($($fun:ident,)+) => {{
+        $(
+            // check type signature
+            let _: fn(f32, f32) -> f32 = libm::$fun;
+            let mut $fun = File::create(concat!("bin/output/musl.", stringify!($fun)))?;
+        )+
+
+        for (x0, x1) in shared::F32F32.iter() {
+            $(
+                let y = unsafe {
+                    extern "C" {
+                        fn $fun(_: f32, _: f32) -> f32;
+                    }
+
+                    $fun(*x0, *x1)
+                };
+
+                $fun.write_all(&y.to_bits().to_bytes())?;
+            )+
+        }
+    }};
+}
+
+macro_rules! f32f32f32 {
+    ($($fun:ident,)+) => {{
+        $(
+            // check type signature
+            let _: fn(f32, f32, f32) -> f32 = libm::$fun;
+            let mut $fun = File::create(concat!("bin/output/musl.", stringify!($fun)))?;
+        )+
+
+            for (x0, x1, x2) in shared::F32F32F32.iter() {
+                $(
+                    let y = unsafe {
+                        extern "C" {
+                            fn $fun(_: f32, _: f32, _: f32) -> f32;
+                        }
+
+                        $fun(*x0, *x1, *x2)
+                    };
+
+                    $fun.write_all(&y.to_bits().to_bytes())?;
+                )+
+            }
+    }};
+}
+
+macro_rules! f32i32 {
+    ($($fun:ident,)+) => {{
+        $(
+            // check type signature
+            let _: fn(f32, i32) -> f32 = libm::$fun;
+            let mut $fun = File::create(concat!("bin/output/musl.", stringify!($fun)))?;
+        )+
+
+            for (x0, x1) in shared::F32I32.iter() {
+                $(
+                    let y = unsafe {
+                        extern "C" {
+                            fn $fun(_: f32, _: i32) -> f32;
+                        }
+
+                        $fun(*x0, *x1 as i32)
+                    };
+
+                    $fun.write_all(&y.to_bits().to_bytes())?;
+                )+
+            }
+    }};
+}
+
+macro_rules! f64 {
+    ($($fun:ident,)+) => {{
+        $(
+            // check type signature
+            let _: fn(f64) -> f64 = libm::$fun;
+            let mut $fun = File::create(concat!("bin/output/musl.", stringify!($fun)))?;
+        )+
+
+        for x in shared::F64.iter() {
+            $(
+                let y = unsafe {
+                    extern "C" {
+                        fn $fun(_: f64) -> f64;
+                    }
+
+                    $fun(*x)
+                };
+
+                $fun.write_all(&y.to_bits().to_bytes())?;
+            )+
+        }
+    }};
+}
+
+macro_rules! f64f64 {
+    ($($fun:ident,)+) => {{
+        $(
+            // check type signature
+            let _: fn(f64, f64) -> f64 = libm::$fun;
+            let mut $fun = File::create(concat!("bin/output/musl.", stringify!($fun)))?;
+        )+
+
+        for (x0, x1) in shared::F64F64.iter() {
+            $(
+                let y = unsafe {
+                    extern "C" {
+                        fn $fun(_: f64, _: f64) -> f64;
+                    }
+
+                    $fun(*x0, *x1)
+                };
+
+                $fun.write_all(&y.to_bits().to_bytes())?;
+            )+
+        }
+    }};
+}
+
+macro_rules! f64f64f64 {
+    ($($fun:ident,)+) => {{
+        $(
+            // check type signature
+            let _: fn(f64, f64, f64) -> f64 = libm::$fun;
+            let mut $fun = File::create(concat!("bin/output/musl.", stringify!($fun)))?;
+        )+
+
+            for (x0, x1, x2) in shared::F64F64F64.iter() {
+                $(
+                    let y = unsafe {
+                        extern "C" {
+                            fn $fun(_: f64, _: f64, _: f64) -> f64;
+                        }
+
+                        $fun(*x0, *x1, *x2)
+                    };
+
+                    $fun.write_all(&y.to_bits().to_bytes())?;
+                )+
+            }
+    }};
+}
+
+macro_rules! f64i32 {
+    ($($fun:ident,)+) => {{
+        $(
+            // check type signature
+            let _: fn(f64, i32) -> f64 = libm::$fun;
+            let mut $fun = File::create(concat!("bin/output/musl.", stringify!($fun)))?;
+        )+
+
+            for (x0, x1) in shared::F64I32.iter() {
+                $(
+                    let y = unsafe {
+                        extern "C" {
+                            fn $fun(_: f64, _: i32) -> f64;
+                        }
+
+                        $fun(*x0, *x1 as i32)
+                    };
+
+                    $fun.write_all(&y.to_bits().to_bytes())?;
+                )+
+            }
+    }};
+}
diff --git a/library/compiler-builtins/libm/musl-generator/src/main.rs b/library/compiler-builtins/libm/musl-generator/src/main.rs
new file mode 100644
index 000000000000..6e57e856dc64
--- /dev/null
+++ b/library/compiler-builtins/libm/musl-generator/src/main.rs
@@ -0,0 +1,97 @@
+extern crate libm;
+extern crate shared;
+
+use std::error::Error;
+use std::fs::File;
+use std::io::Write;
+
+#[macro_use]
+mod macros;
+
+fn main() -> Result<(), Box<Error>> {
+    f32! {
+        acosf,
+        asinf,
+        atanf,
+        cbrtf,
+        ceilf,
+        cosf,
+        coshf,
+        exp2f,
+        expf,
+        expm1f,
+        fabsf,
+        floorf,
+        log10f,
+        log1pf,
+        log2f,
+        logf,
+        roundf,
+        sinf,
+        sinhf,
+        sqrtf,
+        tanf,
+        tanhf,
+        truncf,
+    }
+
+    f32f32! {
+        atan2f,
+        fdimf,
+        fmodf,
+        hypotf,
+        powf,
+    }
+
+    f32i32! {
+        scalbnf,
+    }
+
+    f32f32f32! {
+        fmaf,
+    }
+
+    f64! {
+        acos,
+        asin,
+        atan,
+        cbrt,
+        ceil,
+        cos,
+        cosh,
+        exp,
+        exp2,
+        expm1,
+        fabs,
+        floor,
+        log,
+        log10,
+        log1p,
+        log2,
+        round,
+        sin,
+        sinh,
+        sqrt,
+        tan,
+        tanh,
+        trunc,
+    }
+
+    f64f64! {
+        atan2,
+        fdim,
+        fmod,
+        hypot,
+        pow,
+    }
+
+    f64i32! {
+        scalbn,
+    }
+
+    f64f64f64! {
+        fma,
+    }
+
+    Ok(())
+}
diff --git a/library/compiler-builtins/libm/newlib-generator/Cargo.toml b/library/compiler-builtins/libm/newlib-generator/Cargo.toml
new file mode 100644
index 000000000000..5766cb4b7a05
--- /dev/null
+++ b/library/compiler-builtins/libm/newlib-generator/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "newlib-generator"
+version = "0.1.0"
+authors = ["Jorge Aparicio <jorge@japaric.io>"]
+
+[dependencies]
+shared = { path = "../shared" }
diff --git a/library/compiler-builtins/libm/newlib-generator/src/macros.rs b/library/compiler-builtins/libm/newlib-generator/src/macros.rs
new file mode 100644
index 000000000000..84315a777bde
--- /dev/null
+++ b/library/compiler-builtins/libm/newlib-generator/src/macros.rs
@@ -0,0 +1,245 @@
+macro_rules! f32 {
+    ($($fun:ident,)+) => {
+        $(
+            let fun = stringify!($fun);
+
+            fs::create_dir_all("math/src")?;
+
+            let main = format!("
+#![no_main]
+#![no_std]
+
+#[macro_use]
+extern crate qemu_arm_rt as rt;
+
+use core::u32;
+
+use rt::{{io, process}};
+
+entry!(main);
+
+fn main() {{
+    run().unwrap_or_else(|e| {{
+        eprintln!(\"error: {{}}\", e);
+        process::exit(1);
+    }})
+}}
+
+fn run() -> Result<(), usize> {{
+    #[link(name = \"m\")]
+    extern \"C\" {{
+        fn {0}(_: f32) -> f32;
+    }}
+
+    let mut buf = [0; 4];
+    while let Ok(()) = io::Stdin.read_exact(&mut buf) {{
+        let x = f32::from_bits(u32::from_bytes(buf));
+        let y = unsafe {{ {0}(x) }};
+
+        io::Stdout.write_all(&y.to_bits().to_bytes())?;
+    }}
+
+    Ok(())
+}}
+
+#[no_mangle]
+pub fn __errno() -> *mut i32 {{
+    static mut ERRNO: i32 = 0;
+    unsafe {{ &mut ERRNO }}
+}}
+", fun);
+
+            File::create("math/src/main.rs")?.write_all(main.as_bytes())?;
+
+            assert!(
+                Command::new("cross")
+                    .args(&["build", "--target", "thumbv7em-none-eabi", "--release"])
+                    .current_dir("math")
+                    .status()?
+                .success()
+            );
+
+            let mut qemu = Command::new("qemu-arm")
+                .arg("math/target/thumbv7em-none-eabi/release/math")
+                .stdin(Stdio::piped())
+                .stdout(Stdio::piped())
+                .spawn()?;
+
+            qemu.stdin.as_mut().take().unwrap().write_all(F32)?;
+
+            let output = qemu.wait_with_output()?;
+
+            File::create(concat!("bin/output/newlib.", stringify!($fun)))?
+                .write_all(&output.stdout)?;
+        )+
+    }
+}
+
+macro_rules! f32f32 {
+    ($($fun:ident,)+) => {
+        $(
+            let fun = stringify!($fun);
+
+            fs::create_dir_all("math/src")?;
+
+            let main = format!("
+#![no_main]
+#![no_std]
+
+#[macro_use]
+extern crate qemu_arm_rt as rt;
+
+use core::u32;
+
+use rt::{{io, process}};
+
+entry!(main);
+
+fn main() {{
+    run().unwrap_or_else(|e| {{
+        eprintln!(\"error: {{}}\", e);
+        process::exit(1);
+    }})
+}}
+
+fn run() -> Result<(), usize> {{
+    #[link(name = \"m\")]
+    extern \"C\" {{
+        fn {0}(_: f32, _: f32) -> f32;
+    }}
+
+    let mut chunk = [0; 8];
+    while let Ok(()) = io::Stdin.read_exact(&mut chunk) {{
+        let mut buf = [0; 4];
+        buf.copy_from_slice(&chunk[..4]);
+        let x0 = f32::from_bits(u32::from_bytes(buf));
+
+        buf.copy_from_slice(&chunk[4..]);
+        let x1 = f32::from_bits(u32::from_bytes(buf));
+
+        let y = unsafe {{ {0}(x0, x1) }};
+
+        io::Stdout.write_all(&y.to_bits().to_bytes())?;
+    }}
+
+    Ok(())
+}}
+
+#[no_mangle]
+pub fn __errno() -> *mut i32 {{
+    static mut ERRNO: i32 = 0;
+    unsafe {{ &mut ERRNO }}
+}}
+", fun);
+
+            File::create("math/src/main.rs")?.write_all(main.as_bytes())?;
+
+            assert!(
+                Command::new("cross")
+                    .args(&["build", "--target", "thumbv7em-none-eabi", "--release"])
+                    .current_dir("math")
+                    .status()?
+                .success()
+            );
+
+            let mut qemu = Command::new("qemu-arm")
+                .arg("math/target/thumbv7em-none-eabi/release/math")
+                .stdin(Stdio::piped())
+                .stdout(Stdio::piped())
+                .spawn()?;
+
+            qemu.stdin.as_mut().take().unwrap().write_all(F32)?;
+
+            let output = qemu.wait_with_output()?;
+
+            File::create(concat!("bin/output/newlib.", stringify!($fun)))?
+                .write_all(&output.stdout)?;
+        )+
+    }
+}
+
+macro_rules! f32f32f32 {
+    ($($fun:ident,)+) => {
+        $(
+            let fun = stringify!($fun);
+
+            fs::create_dir_all("math/src")?;
+
+            let main = format!("
+#![no_main]
+#![no_std]
+
+#[macro_use]
+extern crate qemu_arm_rt as rt;
+
+use core::u32;
+
+use rt::{{io, process}};
+
+entry!(main);
+
+fn main() {{
+    run().unwrap_or_else(|e| {{
+        eprintln!(\"error: {{}}\", e);
+        process::exit(1);
+    }})
+}}
+
+fn run() -> Result<(), usize> {{
+    #[link(name = \"m\")]
+    extern \"C\" {{
+        fn {0}(_: f32, _: f32, _: f32) -> f32;
+    }}
+
+    let mut chunk = [0; 12];
+    while let Ok(()) = io::Stdin.read_exact(&mut chunk) {{
+        let mut buf = [0; 4];
+        buf.copy_from_slice(&chunk[..4]);
+        let x0 = f32::from_bits(u32::from_bytes(buf));
+
+        buf.copy_from_slice(&chunk[4..8]);
+        let x1 = f32::from_bits(u32::from_bytes(buf));
+
+        buf.copy_from_slice(&chunk[8..]);
+        let x2 = f32::from_bits(u32::from_bytes(buf));
+
+        let y = unsafe {{ {0}(x0, x1, x2) }};
+
+        io::Stdout.write_all(&y.to_bits().to_bytes())?;
+    }}
+
+    Ok(())
+}}
+
+#[no_mangle]
+pub fn __errno() -> *mut i32 {{
+    static mut ERRNO: i32 = 0;
+    unsafe {{ &mut ERRNO }}
+}}
+", fun);
+
+            File::create("math/src/main.rs")?.write_all(main.as_bytes())?;
+
+            assert!(
+                Command::new("cross")
+                    .args(&["build", "--target", "thumbv7em-none-eabi", "--release"])
+                    .current_dir("math")
+                    .status()?
+                .success()
+            );
+
+            let mut qemu = Command::new("qemu-arm")
+                .arg("math/target/thumbv7em-none-eabi/release/math")
+                .stdin(Stdio::piped())
+                .stdout(Stdio::piped())
+                .spawn()?;
+
+            qemu.stdin.as_mut().take().unwrap().write_all(F32)?;
+
+            let output = qemu.wait_with_output()?;
+
+            File::create(concat!("bin/output/newlib.", stringify!($fun)))?
+                .write_all(&output.stdout)?;
+        )+
+    }
+}
diff --git a/library/compiler-builtins/libm/newlib-generator/src/main.rs b/library/compiler-builtins/libm/newlib-generator/src/main.rs
new file mode 100644
index 000000000000..52a97cabbfd4
--- /dev/null
+++ b/library/compiler-builtins/libm/newlib-generator/src/main.rs
@@ -0,0 +1,32 @@
+extern crate shared;
+
+use std::error::Error;
+use std::fs::{self, File};
+use std::io::Write;
+use std::process::{Command, Stdio};
+
+#[macro_use]
+mod macros;
+
+fn main() -> Result<(), Box<Error>> {
+    const F32: &[u8] = include_bytes!("../../bin/input/f32");
+
+    f32! {
+        asinf,
+        cbrtf,
+        cosf,
+        exp2f,
+        sinf,
+        tanf,
+    }
+
+    f32f32! {
+        hypotf,
+    }
+
+    f32f32f32! {
+        fmaf,
+    }
+
+    Ok(())
+}
diff --git a/library/compiler-builtins/libm/shared/Cargo.toml b/library/compiler-builtins/libm/shared/Cargo.toml
new file mode 100644
index 000000000000..d77823781016
--- /dev/null
+++ b/library/compiler-builtins/libm/shared/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "shared"
+version = "0.1.0"
+authors = ["Jorge Aparicio <jorge@japaric.io>"]
+
+[dependencies]
+lazy_static = "1.0.2"
diff --git a/library/compiler-builtins/libm/shared/src/lib.rs b/library/compiler-builtins/libm/shared/src/lib.rs
new file mode 100644
index 000000000000..84676f94f747
--- /dev/null
+++ b/library/compiler-builtins/libm/shared/src/lib.rs
@@ -0,0 +1,471 @@
+#![feature(exact_chunks)]
+
+#[macro_use]
+extern crate lazy_static;
+
+lazy_static! {
+    pub static ref F32: Vec<f32> = {
+        let bytes = include_bytes!("../../bin/input/f32");
+
+        bytes
+            .exact_chunks(4)
+            .map(|chunk| {
+                let mut buf = [0; 4];
+                buf.copy_from_slice(chunk);
+                f32::from_bits(u32::from_le(u32::from_bytes(buf)))
+            })
+            .collect()
+    };
+    pub static ref F32F32: Vec<(f32, f32)> = {
+        let bytes = include_bytes!("../../bin/input/f32f32");
+
+        bytes
+            .exact_chunks(8)
+            .map(|chunk| {
+                let mut x0 = [0; 4];
+                let mut x1 = [0; 4];
+                x0.copy_from_slice(&chunk[..4]);
+                x1.copy_from_slice(&chunk[4..]);
+
+                (
+                    f32::from_bits(u32::from_le(u32::from_bytes(x0))),
+                    f32::from_bits(u32::from_le(u32::from_bytes(x1))),
+                )
+            })
+            .collect()
+    };
+    pub static ref F32F32F32: Vec<(f32, f32, f32)> = {
+        let bytes = include_bytes!("../../bin/input/f32f32f32");
+
+        bytes
+            .exact_chunks(12)
+            .map(|chunk| {
+                let mut x0 = [0; 4];
+                let mut x1 = [0; 4];
+                let mut x2 = [0; 4];
+                x0.copy_from_slice(&chunk[..4]);
+                x1.copy_from_slice(&chunk[4..8]);
+                x2.copy_from_slice(&chunk[8..]);
+
+                (
+                    f32::from_bits(u32::from_le(u32::from_bytes(x0))),
+                    f32::from_bits(u32::from_le(u32::from_bytes(x1))),
+                    f32::from_bits(u32::from_le(u32::from_bytes(x2))),
+                )
+            })
+            .collect()
+    };
+    pub static ref F32I32: Vec<(f32, i32)> = {
+        let bytes = include_bytes!("../../bin/input/f32i16");
+
+        bytes
+            .exact_chunks(6)
+            .map(|chunk| {
+                let mut x0 = [0; 4];
+                let mut x1 = [0; 2];
+                x0.copy_from_slice(&chunk[..4]);
+                x1.copy_from_slice(&chunk[4..]);
+
+                (
+                    f32::from_bits(u32::from_le(u32::from_bytes(x0))),
+                    i16::from_le(i16::from_bytes(x1)) as i32,
+                )
+            })
+            .collect()
+    };
+    pub static ref F64: Vec<f64> = {
+        let bytes = include_bytes!("../../bin/input/f64");
+
+        bytes
+            .exact_chunks(8)
+            .map(|chunk| {
+                let mut buf = [0; 8];
+                buf.copy_from_slice(chunk);
+                f64::from_bits(u64::from_le(u64::from_bytes(buf)))
+            })
+            .collect()
+    };
+    pub static ref F64F64: Vec<(f64, f64)> = {
+        let bytes = include_bytes!("../../bin/input/f64f64");
+
+        bytes
+            .exact_chunks(16)
+            .map(|chunk| {
+                let mut x0 = [0; 8];
+                let mut x1 = [0; 8];
+                x0.copy_from_slice(&chunk[..8]);
+                x1.copy_from_slice(&chunk[8..]);
+
+                (
+                    f64::from_bits(u64::from_le(u64::from_bytes(x0))),
+                    f64::from_bits(u64::from_le(u64::from_bytes(x1))),
+                )
+            })
+            .collect()
+    };
+    pub static ref F64F64F64: Vec<(f64, f64, f64)> = {
+        let bytes = include_bytes!("../../bin/input/f64f64f64");
+
+        bytes
+            .exact_chunks(24)
+            .map(|chunk| {
+                let mut x0 = [0; 8];
+                let mut x1 = [0; 8];
+                let mut x2 = [0; 8];
+                x0.copy_from_slice(&chunk[..8]);
+                x1.copy_from_slice(&chunk[8..16]);
+                x2.copy_from_slice(&chunk[16..]);
+
+                (
+                    f64::from_bits(u64::from_le(u64::from_bytes(x0))),
+                    f64::from_bits(u64::from_le(u64::from_bytes(x1))),
+                    f64::from_bits(u64::from_le(u64::from_bytes(x2))),
+                )
+            })
+            .collect()
+    };
+    pub static ref F64I32: Vec<(f64, i32)> = {
+        let bytes = include_bytes!("../../bin/input/f64i16");
+
+        bytes
+            .exact_chunks(10)
+            .map(|chunk| {
+                let mut x0 = [0; 8];
+                let mut x1 = [0; 2];
+                x0.copy_from_slice(&chunk[..8]);
+                x1.copy_from_slice(&chunk[8..]);
+
+                (
+                    f64::from_bits(u64::from_le(u64::from_bytes(x0))),
+                    i16::from_le(i16::from_bytes(x1)) as i32,
+                )
+            })
+            .collect()
+    };
+}
+
+#[macro_export]
+macro_rules! f32 {
+    ($lib:expr, $($fun:ident),+) => {
+        $(
+            #[test]
+            fn $fun() {
+                let expected = include_bytes!(concat!("../bin/output/", $lib, ".", stringify!($fun)))
+                    .exact_chunks(4)
+                    .map(|chunk| {
+                        let mut buf = [0; 4];
+                        buf.copy_from_slice(chunk);
+                        f32::from_bits(u32::from_le(u32::from_bytes(buf)))
+                    })
+                    .collect::<Vec<_>>();
+
+                for (input, expected) in $crate::F32.iter().zip(&expected) {
+                    if let Ok(output) = panic::catch_unwind(|| libm::$fun(*input)) {
+                        if let Err(error) = libm::_eqf(output, *expected) {
+                            panic!(
+                                "INPUT: {:#x}, OUTPUT: {:#x}, EXPECTED: {:#x}, ERROR: {}",
+                                input.to_bits(),
+                                output.to_bits(),
+                                expected.to_bits(),
+                                error
+                            );
+                        }
+                    } else {
+                        panic!(
+                            "INPUT: {:#x}, OUTPUT: PANIC!, EXPECTED: {:#x}",
+                            input.to_bits(),
+                            expected.to_bits()
+                        );
+                    }
+                }
+            }
+        )+
+    }
+}
+
+#[macro_export]
+macro_rules! f32f32 {
+    ($lib:expr, $($fun:ident),+) => {
+        $(
+            #[test]
+            fn $fun() {
+                let expected = include_bytes!(concat!("../bin/output/", $lib, ".", stringify!($fun)))
+                    .exact_chunks(4)
+                    .map(|chunk| {
+                        let mut buf = [0; 4];
+                        buf.copy_from_slice(chunk);
+                        f32::from_bits(u32::from_le(u32::from_bytes(buf)))
+                    })
+                    .collect::<Vec<_>>();
+
+                for ((i0, i1), expected) in $crate::F32F32.iter().zip(&expected) {
+                    if let Ok(output) = panic::catch_unwind(|| libm::$fun(*i0, *i1)) {
+                        if let Err(error) = libm::_eqf(output, *expected) {
+                            panic!(
+                                "INPUT: ({:#x}, {:#x}), OUTPUT: {:#x}, EXPECTED: {:#x}, ERROR: {}",
+                                i0.to_bits(),
+                                i1.to_bits(),
+                                output.to_bits(),
+                                expected.to_bits(),
+                                error
+                            );
+                        }
+                    } else {
+                        panic!(
+                            "INPUT: ({:#x}, {:#x}), OUTPUT: PANIC!, EXPECTED: {:#x}",
+                            i0.to_bits(),
+                            i1.to_bits(),
+                            expected.to_bits()
+                        );
+                    }
+                }
+            }
+        )+
+    }
+}
+
+#[macro_export]
+macro_rules! f32f32f32 {
+    ($lib:expr, $($fun:ident),+) => {
+        $(
+            #[test]
+            fn $fun() {
+                let expected = include_bytes!(concat!("../bin/output/", $lib, ".", stringify!($fun)))
+                    .exact_chunks(4)
+                    .map(|chunk| {
+                        let mut buf = [0; 4];
+                        buf.copy_from_slice(chunk);
+                        f32::from_bits(u32::from_le(u32::from_bytes(buf)))
+                    })
+                    .collect::<Vec<_>>();
+
+                for ((i0, i1, i2), expected) in $crate::F32F32F32.iter().zip(&expected) {
+                    if let Ok(output) = panic::catch_unwind(|| libm::$fun(*i0, *i1, *i2)) {
+                        if let Err(error) = libm::_eqf(output, *expected) {
+                            panic!(
+                                "INPUT: ({:#x}, {:#x}, {:#x}), OUTPUT: {:#x}, EXPECTED: {:#x}, ERROR: {}",
+                                i0.to_bits(),
+                                i1.to_bits(),
+                                i2.to_bits(),
+                                output.to_bits(),
+                                expected.to_bits(),
+                                error
+                            );
+                        }
+                    } else {
+                        panic!(
+                            "INPUT: ({:#x}, {:#x}), OUTPUT: PANIC!, EXPECTED: {:#x}",
+                            i0.to_bits(),
+                            i1.to_bits(),
+                            expected.to_bits()
+                        );
+                    }
+                }
+            }
+        )+
+    }
+}
+
+#[macro_export]
+macro_rules! f32i32 {
+    ($lib:expr, $($fun:ident),+) => {
+        $(
+            #[test]
+            fn $fun() {
+                let expected = include_bytes!(concat!("../bin/output/", $lib, ".", stringify!($fun)))
+                    .exact_chunks(4)
+                    .map(|chunk| {
+                        let mut buf = [0; 4];
+                        buf.copy_from_slice(chunk);
+                        f32::from_bits(u32::from_le(u32::from_bytes(buf)))
+                    })
+                    .collect::<Vec<_>>();
+
+                for ((i0, i1), expected) in $crate::F32I32.iter().zip(&expected) {
+                    if let Ok(output) = panic::catch_unwind(|| libm::$fun(*i0, *i1)) {
+                        if let Err(error) = libm::_eqf(output, *expected) {
+                            panic!(
+                                "INPUT: ({:#x}, {:#x}), OUTPUT: {:#x}, EXPECTED: {:#x}, ERROR: {}",
+                                i0.to_bits(),
+                                i1,
+                                output.to_bits(),
+                                expected.to_bits(),
+                                error
+                            );
+                        }
+                    } else {
+                        panic!(
+                            "INPUT: ({:#x}, {:#x}), OUTPUT: PANIC!, EXPECTED: {:#x}",
+                            i0.to_bits(),
+                            i1,
+                            expected.to_bits()
+                        );
+                    }
+                }
+            }
+        )+
+    }
+}
+
+#[macro_export]
+macro_rules! f64 {
+    ($lib:expr, $($fun:ident),+) => {
+        $(
+            #[test]
+            fn $fun() {
+                let expected = include_bytes!(concat!("../bin/output/", $lib, ".", stringify!($fun)))
+                    .exact_chunks(8)
+                    .map(|chunk| {
+                        let mut buf = [0; 8];
+                        buf.copy_from_slice(chunk);
+                        f64::from_bits(u64::from_le(u64::from_bytes(buf)))
+                    })
+                    .collect::<Vec<_>>();
+
+                for (input, expected) in shared::F64.iter().zip(&expected) {
+                    if let Ok(output) = panic::catch_unwind(|| libm::$fun(*input)) {
+                        if let Err(error) = libm::_eq(output, *expected) {
+                            panic!(
+                                "INPUT: {:#x}, OUTPUT: {:#x}, EXPECTED: {:#x}, ERROR: {}",
+                                input.to_bits(),
+                                output.to_bits(),
+                                expected.to_bits(),
+                                error
+                            );
+                        }
+                    } else {
+                        panic!(
+                            "INPUT: {:#x}, OUTPUT: PANIC!, EXPECTED: {:#x}",
+                            input.to_bits(),
+                            expected.to_bits()
+                        );
+                    }
+                }
+            }
+        )+
+    }
+}
+
+#[macro_export]
+macro_rules! f64f64 {
+    ($lib:expr, $($fun:ident),+) => {
+        $(
+            #[test]
+            fn $fun() {
+                let expected = include_bytes!(concat!("../bin/output/", $lib, ".", stringify!($fun)))
+                    .exact_chunks(8)
+                    .map(|chunk| {
+                        let mut buf = [0; 8];
+                        buf.copy_from_slice(chunk);
+                        f64::from_bits(u64::from_le(u64::from_bytes(buf)))
+                    })
+                    .collect::<Vec<_>>();
+
+                for ((i0, i1), expected) in shared::F64F64.iter().zip(&expected) {
+                    if let Ok(output) = panic::catch_unwind(|| libm::$fun(*i0, *i1)) {
+                        if let Err(error) = libm::_eq(output, *expected) {
+                            panic!(
+                                "INPUT: ({:#x}, {:#x}), OUTPUT: {:#x}, EXPECTED: {:#x}, ERROR: {}",
+                                i0.to_bits(),
+                                i1.to_bits(),
+                                output.to_bits(),
+                                expected.to_bits(),
+                                error
+                            );
+                        }
+                    } else {
+                        panic!(
+                            "INPUT: ({:#x}, {:#x}), OUTPUT: PANIC!, EXPECTED: {:#x}",
+                            i0.to_bits(),
+                            i1.to_bits(),
+                            expected.to_bits()
+                        );
+                    }
+                }
+            }
+        )+
+    }
+}
+
+#[macro_export]
+macro_rules! f64f64f64 {
+    ($lib:expr, $($fun:ident),+) => {
+        $(
+            #[test]
+            fn $fun() {
+                let expected = include_bytes!(concat!("../bin/output/", $lib, ".", stringify!($fun)))
+                    .exact_chunks(8)
+                    .map(|chunk| {
+                        let mut buf = [0; 8];
+                        buf.copy_from_slice(chunk);
+                        f64::from_bits(u64::from_le(u64::from_bytes(buf)))
+                    })
+                    .collect::<Vec<_>>();
+
+                for ((i0, i1, i2), expected) in shared::F64F64F64.iter().zip(&expected) {
+                    if let Ok(output) = panic::catch_unwind(|| libm::$fun(*i0, *i1, *i2)) {
+                        if let Err(error) = libm::_eq(output, *expected) {
+                            panic!(
+                                "INPUT: ({:#x}, {:#x}, {:#x}), OUTPUT: {:#x}, EXPECTED: {:#x}, ERROR: {}",
+                                i0.to_bits(),
+                                i1.to_bits(),
+                                i2.to_bits(),
+                                output.to_bits(),
+                                expected.to_bits(),
+                                error
+                            );
+                        }
+                    } else {
+                        panic!(
+                            "INPUT: ({:#x}, {:#x}), OUTPUT: PANIC!, EXPECTED: {:#x}",
+                            i0.to_bits(),
+                            i1.to_bits(),
+                            expected.to_bits()
+                        );
+                    }
+                }
+            }
+        )+
+    }
+}
+
+#[macro_export]
+macro_rules! f64i32 {
+    ($lib:expr, $($fun:ident),+) => {
+        $(
+            #[test]
+            fn $fun() {
+                let expected = include_bytes!(concat!("../bin/output/", $lib, ".", stringify!($fun)))
+                    .exact_chunks(8)
+                    .map(|chunk| {
+                        let mut buf = [0; 8];
+                        buf.copy_from_slice(chunk);
+                        f64::from_bits(u64::from_le(u64::from_bytes(buf)))
+                    })
+                    .collect::<Vec<_>>();
+
+                for ((i0, i1), expected) in shared::F64I32.iter().zip(&expected) {
+                    if let Ok(output) = panic::catch_unwind(|| libm::$fun(*i0, *i1)) {
+                        if let Err(error) = libm::_eq(output, *expected) {
+                            panic!(
+                                "INPUT: ({:#x}, {:#x}), OUTPUT: {:#x}, EXPECTED: {:#x}, ERROR: {}",
+                                i0.to_bits(),
+                                i1,
+                                output.to_bits(),
+                                expected.to_bits(),
+                                error
+                            );
+                        }
+                    } else {
+                        panic!(
+                            "INPUT: ({:#x}, {:#x}), OUTPUT: PANIC!, EXPECTED: {:#x}",
+                            i0.to_bits(),
+                            i1,
+                            expected.to_bits()
+                        );
+                    }
+                }
+            }
+        )+
+    }
+}
diff --git a/library/compiler-builtins/libm/src/lib.rs b/library/compiler-builtins/libm/src/lib.rs
index 5121cbfbacf3..627c6443e3dc 100644
--- a/library/compiler-builtins/libm/src/lib.rs
+++ b/library/compiler-builtins/libm/src/lib.rs
@@ -21,14 +21,34 @@ pub use math::*;
 /// Approximate equality with 1 ULP of tolerance
 #[doc(hidden)]
 #[inline]
-pub fn _eqf(a: u32, b: u32) -> bool {
-    (a as i32).wrapping_sub(b as i32).abs() <= 1
+pub fn _eqf(a: f32, b: f32) -> Result<(), u32> {
+    if a.is_nan() && b.is_nan() {
+        Ok(())
+    } else {
+        let err = (a.to_bits() as i32).wrapping_sub(b.to_bits() as i32).abs();
+
+        if err <= 1 {
+            Ok(())
+        } else {
+            Err(err as u32)
+        }
+    }
 }
 
 #[doc(hidden)]
 #[inline]
-pub fn _eq(a: u64, b: u64) -> bool {
-    (a as i64).wrapping_sub(b as i64).abs() <= 1
+pub fn _eq(a: f64, b: f64) -> Result<(), u64> {
+    if a.is_nan() && b.is_nan() {
+        Ok(())
+    } else {
+        let err = (a.to_bits() as i64).wrapping_sub(b.to_bits() as i64).abs();
+
+        if err <= 1 {
+            Ok(())
+        } else {
+            Err(err as u64)
+        }
+    }
 }
 
 /// Math support for `f32`
diff --git a/library/compiler-builtins/libm/test-generator/README.md b/library/compiler-builtins/libm/test-generator/README.md
deleted file mode 100644
index cbacd88f14d2..000000000000
--- a/library/compiler-builtins/libm/test-generator/README.md
+++ /dev/null
@@ -1,8 +0,0 @@
-# `test-generator`
-
-This is a tool to generate test cases for the `libm` crate.
-
-The generator randomly creates inputs for each math function, then proceeds to compute the
-expected output for the given function by running the MUSL *C implementation* of the function and
-finally it packs the test cases as a Cargo test file. For this reason, this generator **must**
-always be compiled for the `x86_64-unknown-linux-musl` target.
diff --git a/library/compiler-builtins/libm/test-generator/src/main.rs b/library/compiler-builtins/libm/test-generator/src/main.rs
deleted file mode 100644
index 4c4e420a2852..000000000000
--- a/library/compiler-builtins/libm/test-generator/src/main.rs
+++ /dev/null
@@ -1,788 +0,0 @@
-// NOTE we intentionally avoid using the `quote` crate here because it doesn't work with the
-// `x86_64-unknown-linux-musl` target.
-
-// NOTE usually the only thing you need to do to test a new math function is to add it to one of the
-// macro invocations found in the bottom of this file.
-
-#[macro_use]
-extern crate itertools;
-extern crate rand;
-
-use std::error::Error;
-use std::fmt::Write as _0;
-use std::fs::{self, File};
-use std::io::Write as _1;
-use std::{f32, f64, i16, u16, u32, u64, u8};
-
-use rand::{Rng, SeedableRng, XorShiftRng};
-
-// Number of test cases to generate
-const NTESTS: usize = 10_000;
-
-// TODO tweak these functions to generate edge cases (zero, infinity, NaN) more often
-fn f32(rng: &mut XorShiftRng) -> f32 {
-    let sign = if rng.gen_bool(0.5) { 1 << 31 } else { 0 };
-    let exponent = (rng.gen_range(0, u8::MAX) as u32) << 23;
-    let mantissa = rng.gen_range(0, u32::MAX) & ((1 << 23) - 1);
-
-    f32::from_bits(sign + exponent + mantissa)
-}
-
-fn f64(rng: &mut XorShiftRng) -> f64 {
-    let sign = if rng.gen_bool(0.5) { 1 << 63 } else { 0 };
-    let exponent = (rng.gen_range(0, u16::MAX) as u64 & ((1 << 11) - 1)) << 52;
-    let mantissa = rng.gen_range(0, u64::MAX) & ((1 << 52) - 1);
-
-    f64::from_bits(sign + exponent + mantissa)
-}
-
-const EDGE_CASES32: &[f32] = &[
-    -0.,
-    0.,
-    f32::EPSILON,
-    f32::INFINITY,
-    f32::MAX,
-    f32::MIN,
-    f32::MIN_POSITIVE,
-    f32::NAN,
-    f32::NEG_INFINITY,
-];
-
-const EDGE_CASES64: &[f64] = &[
-    -0.,
-    0.,
-    f64::EPSILON,
-    f64::INFINITY,
-    f64::MAX,
-    f64::MIN,
-    f64::MIN_POSITIVE,
-    f64::NAN,
-    f64::NEG_INFINITY,
-];
-
-// fn(f32) -> f32
-macro_rules! f32_f32 {
-    ($($intr:ident,)*) => {
-        fn f32_f32(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
-            // MUSL C implementation of the function to test
-            extern "C" {
-                $(fn $intr(_: f32) -> f32;)*
-            }
-
-            $(
-                let mut cases = String::new();
-
-                // random inputs
-                for inp in EDGE_CASES32.iter().cloned().chain((0..NTESTS).map(|_| f32(rng))) {
-                    let out = unsafe { $intr(inp) };
-
-                    let inp = inp.to_bits();
-                    let out = out.to_bits();
-
-                    write!(cases, "({}, {})", inp, out).unwrap();
-                    cases.push(',');
-                }
-
-                let mut f = File::create(concat!("tests/", stringify!($intr), ".rs"))?;
-                write!(f, "
-                    #![deny(warnings)]
-
-                    extern crate libm;
-
-                    use std::panic;
-
-                    #[test]
-                    fn {0}() {{
-                        const CASES: &[(u32, u32)] = &[
-                            {1}
-                        ];
-
-                        for case in CASES {{
-                            let (inp, expected) = *case;
-
-                            if let Ok(outf) =
-                                panic::catch_unwind(|| libm::{0}(f32::from_bits(inp)))
-                            {{
-                                let outi = outf.to_bits();
-
-                                if !((outf.is_nan() && f32::from_bits(expected).is_nan())
-                                    || libm::_eqf(outi, expected))
-                                {{
-                                    panic!(
-                                        \"input: {{}}, output: {{}}, expected: {{}}\",
-                                        inp, outi, expected,
-                                    );
-                                }}
-                            }} else {{
-                                panic!(
-                                    \"input: {{}}, output: PANIC, expected: {{}}\",
-                                    inp, expected,
-                                );
-                            }}
-                        }}
-                    }}
-",
-                       stringify!($intr),
-                       cases)?;
-            )*
-
-            Ok(())
-        }
-    }
-}
-
-// fn(f32, f32) -> f32
-macro_rules! f32f32_f32 {
-    ($($intr:ident,)*) => {
-        fn f32f32_f32(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
-            extern "C" {
-                $(fn $intr(_: f32, _: f32) -> f32;)*
-            }
-
-            let mut rng2 = rng.clone();
-            let mut rng3 = rng.clone();
-            $(
-                let mut cases = String::new();
-                for (i1, i2) in iproduct!(
-                    EDGE_CASES32.iter().cloned(),
-                    EDGE_CASES32.iter().cloned()
-                ).chain(EDGE_CASES32.iter().map(|i1| (*i1, f32(rng))))
-                    .chain(EDGE_CASES32.iter().map(|i2| (f32(&mut rng2), *i2)))
-                    .chain((0..NTESTS).map(|_| (f32(&mut rng3), f32(&mut rng3))))
-                {
-                    let out = unsafe { $intr(i1, i2) };
-
-                    let i1 = i1.to_bits();
-                    let i2 = i2.to_bits();
-                    let out = out.to_bits();
-
-                    write!(cases, "(({}, {}), {})", i1, i2, out).unwrap();
-                    cases.push(',');
-                }
-
-                let mut f = File::create(concat!("tests/", stringify!($intr), ".rs"))?;
-                write!(f, "
-                    #![deny(warnings)]
-
-                    extern crate libm;
-
-                    use std::panic;
-
-                    #[test]
-                    fn {0}() {{
-                        const CASES: &[((u32, u32), u32)] = &[
-                            {1}
-                        ];
-
-                        for case in CASES {{
-                            let ((i1, i2), expected) = *case;
-
-                            if let Ok(outf) = panic::catch_unwind(|| {{
-                                libm::{0}(f32::from_bits(i1), f32::from_bits(i2))
-                            }}) {{
-                                let outi = outf.to_bits();
-
-                                if !((outf.is_nan() && f32::from_bits(expected).is_nan())
-                                    || libm::_eqf(outi, expected))
-                                {{
-                                    panic!(
-                                        \"input: {{:?}}, output: {{}}, expected: {{}}\",
-                                        (i1, i2),
-                                        outi,
-                                        expected,
-                                    );
-                                }}
-                            }} else {{
-                                panic!(
-                                    \"input: {{:?}}, output: PANIC, expected: {{}}\",
-                                    (i1, i2),
-                                    expected,
-                                );
-                            }}
-                        }}
-                    }}
-",
-                       stringify!($intr),
-                       cases)?;
-            )*
-
-            Ok(())
-        }
-    };
-}
-
-// fn(f32, f32, f32) -> f32
-macro_rules! f32f32f32_f32 {
-    ($($intr:ident,)*) => {
-        fn f32f32f32_f32(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
-            extern "C" {
-                $(fn $intr(_: f32, _: f32, _: f32) -> f32;)*
-            }
-
-            let mut rng2 = rng.clone();
-            $(
-                let mut cases = String::new();
-                for (i1, i2, i3) in iproduct!(
-                    EDGE_CASES32.iter().cloned(),
-                    EDGE_CASES32.iter().cloned(),
-                    EDGE_CASES32.iter().cloned()
-                ).chain(EDGE_CASES32.iter().map(|i1| (*i1, f32(rng), f32(rng))))
-                    .chain((0..NTESTS).map(|_| (f32(&mut rng2), f32(&mut rng2), f32(&mut rng2))))
-                {
-                    let out = unsafe { $intr(i1, i2, i3) };
-
-                    let i1 = i1.to_bits();
-                    let i2 = i2.to_bits();
-                    let i3 = i3.to_bits();
-                    let out = out.to_bits();
-
-                    write!(cases, "(({}, {}, {}), {})", i1, i2, i3, out).unwrap();
-                    cases.push(',');
-                }
-
-                let mut f = File::create(concat!("tests/", stringify!($intr), ".rs"))?;
-                write!(f, "
-                    #![deny(warnings)]
-
-                    extern crate libm;
-
-                    use std::panic;
-
-                    #[test]
-                    fn {0}() {{
-                        const CASES: &[((u32, u32, u32), u32)] = &[
-                            {1}
-                        ];
-
-                        for case in CASES {{
-                            let ((i1, i2, i3), expected) = *case;
-
-                            if let Ok(outf) = panic::catch_unwind(|| {{
-                                libm::{0}(
-                                    f32::from_bits(i1),
-                                    f32::from_bits(i2),
-                                    f32::from_bits(i3),
-                                )
-                            }}) {{
-                                let outi = outf.to_bits();
-
-                                if !((outf.is_nan() && f32::from_bits(expected).is_nan())
-                                    || libm::_eqf(outi, expected))
-                                {{
-                                    panic!(
-                                        \"input: {{:?}}, output: {{}}, expected: {{}}\",
-                                        (i1, i2, i3),
-                                        outi,
-                                        expected,
-                                    );
-                                }}
-                            }} else {{
-                                panic!(
-                                    \"input: {{:?}}, output: PANIC, expected: {{}}\",
-                                    (i1, i2, i3),
-                                    expected,
-                                );
-                            }}
-                        }}
-                    }}
-",
-                       stringify!($intr),
-                       cases)?;
-            )*
-
-            Ok(())
-        }
-    };
-}
-
-// fn(f32, i32) -> f32
-macro_rules! f32i32_f32 {
-    ($($intr:ident,)*) => {
-        fn f32i32_f32(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
-            extern "C" {
-                $(fn $intr(_: f32, _: i32) -> f32;)*
-            }
-
-            let mut rng2 = rng.clone();
-            $(
-                let mut cases = String::new();
-                for i1 in EDGE_CASES32.iter().cloned().chain((0..NTESTS).map(|_| f32(&mut rng2))) {
-                    let i2 = rng.gen_range(i16::MIN, i16::MAX);
-                    let out = unsafe { $intr(i1, i2 as i32) };
-
-                    let i1 = i1.to_bits();
-                    let out = out.to_bits();
-
-                    write!(cases, "(({}, {}), {})", i1, i2, out).unwrap();
-                    cases.push(',');
-                }
-
-                let mut f = File::create(concat!("tests/", stringify!($intr), ".rs"))?;
-                write!(f, "
-                    #![deny(warnings)]
-
-                    extern crate libm;
-
-                    use std::panic;
-
-                    #[test]
-                    fn {0}() {{
-                        const CASES: &[((u32, i16), u32)] = &[
-                            {1}
-                        ];
-
-                        for case in CASES {{
-                            let ((i1, i2), expected) = *case;
-
-                            if let Ok(outf) = panic::catch_unwind(|| {{
-                                libm::{0}(f32::from_bits(i1), i2 as i32)
-                            }}) {{
-                                let outi = outf.to_bits();
-
-                                if !((outf.is_nan() && f32::from_bits(expected).is_nan())
-                                    || libm::_eqf(outi, expected))
-                                {{
-                                    panic!(
-                                        \"input: {{:?}}, output: {{}}, expected: {{}}\",
-                                        (i1, i2),
-                                        outi,
-                                        expected,
-                                    );
-                                }}
-                            }} else {{
-                                panic!(
-                                    \"input: {{:?}}, output: PANIC, expected: {{}}\",
-                                    (i1, i2),
-                                    expected,
-                                );
-                            }}
-                        }}
-                    }}
-",
-                       stringify!($intr),
-                       cases)?;
-            )*
-
-            Ok(())
-        }
-    };
-}
-
-// fn(f64) -> f64
-macro_rules! f64_f64 {
-    ($($intr:ident,)*) => {
-        fn f64_f64(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
-            // MUSL C implementation of the function to test
-            extern "C" {
-                $(fn $intr(_: f64) -> f64;)*
-            }
-
-            $(
-                let mut cases = String::new();
-                for inp in EDGE_CASES64.iter().cloned().chain((0..NTESTS).map(|_| f64(rng))) {
-                    let out = unsafe { $intr(inp) };
-
-                    let inp = inp.to_bits();
-                    let out = out.to_bits();
-
-                    write!(cases, "({}, {})", inp, out).unwrap();
-                    cases.push(',');
-                }
-
-                let mut f = File::create(concat!("tests/", stringify!($intr), ".rs"))?;
-                write!(f, "
-                    #![deny(warnings)]
-
-                    extern crate libm;
-
-                    use std::panic;
-
-                    #[test]
-                    fn {0}() {{
-                        const CASES: &[(u64, u64)] = &[
-                            {1}
-                        ];
-
-                        for case in CASES {{
-                            let (inp, expected) = *case;
-
-                            if let Ok(outf) = panic::catch_unwind(|| {{
-                                libm::{0}(f64::from_bits(inp))
-                            }}) {{
-                                let outi = outf.to_bits();
-
-                                if !((outf.is_nan() && f64::from_bits(expected).is_nan())
-                                    || libm::_eq(outi, expected))
-                                {{
-                                    panic!(
-                                        \"input: {{}}, output: {{}}, expected: {{}}\",
-                                        inp,
-                                        outi,
-                                        expected,
-                                    );
-                                }}
-                            }} else {{
-                                panic!(
-                                    \"input: {{}}, output: PANIC, expected: {{}}\",
-                                    inp,
-                                    expected,
-                                );
-                            }}
-                        }}
-                    }}
-",
-                       stringify!($intr),
-                       cases)?;
-            )*
-
-            Ok(())
-        }
-    }
-}
-
-// fn(f64, f64) -> f64
-macro_rules! f64f64_f64 {
-    ($($intr:ident,)*) => {
-        fn f64f64_f64(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
-            extern "C" {
-                $(fn $intr(_: f64, _: f64) -> f64;)*
-            }
-
-            let mut rng2 = rng.clone();
-            let mut rng3 = rng.clone();
-            $(
-                let mut cases = String::new();
-                for (i1, i2) in iproduct!(
-                    EDGE_CASES64.iter().cloned(),
-                    EDGE_CASES64.iter().cloned()
-                ).chain(EDGE_CASES64.iter().map(|i1| (*i1, f64(rng))))
-                    .chain(EDGE_CASES64.iter().map(|i2| (f64(&mut rng2), *i2)))
-                    .chain((0..NTESTS).map(|_| (f64(&mut rng3), f64(&mut rng3))))
-                {
-                    let out = unsafe { $intr(i1, i2) };
-
-                    let i1 = i1.to_bits();
-                    let i2 = i2.to_bits();
-                    let out = out.to_bits();
-
-                    write!(cases, "(({}, {}), {})", i1, i2, out).unwrap();
-                    cases.push(',');
-                }
-
-                let mut f = File::create(concat!("tests/", stringify!($intr), ".rs"))?;
-                write!(f, "
-                    #![deny(warnings)]
-
-                    extern crate libm;
-
-                    use std::panic;
-
-                    #[test]
-                    fn {0}() {{
-                        const CASES: &[((u64, u64), u64)] = &[
-                            {1}
-                        ];
-
-                        for case in CASES {{
-                            let ((i1, i2), expected) = *case;
-
-                            if let Ok(outf) = panic::catch_unwind(|| {{
-                                libm::{0}(f64::from_bits(i1), f64::from_bits(i2))
-                            }}) {{
-                                let outi = outf.to_bits();
-
-                                if !((outf.is_nan() && f64::from_bits(expected).is_nan()) ||
-                                    libm::_eq(outi, expected)) {{
-                                    panic!(
-                                        \"input: {{:?}}, output: {{}}, expected: {{}}\",
-                                        (i1, i2),
-                                        outi,
-                                        expected,
-                                    );
-                                }}
-                            }} else {{
-                                panic!(
-                                    \"input: {{:?}}, output: PANIC, expected: {{}}\",
-                                    (i1, i2),
-                                    expected,
-                                );
-                            }}
-                        }}
-                    }}
-",
-                       stringify!($intr),
-                       cases)?;
-            )*
-
-            Ok(())
-        }
-    };
-}
-
-// fn(f64, f64, f64) -> f64
-macro_rules! f64f64f64_f64 {
-    ($($intr:ident,)*) => {
-        fn f64f64f64_f64(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
-            extern "C" {
-                $(fn $intr(_: f64, _: f64, _: f64) -> f64;)*
-            }
-
-            let mut rng2 = rng.clone();
-            $(
-                let mut cases = String::new();
-                for (i1, i2, i3) in iproduct!(
-                    EDGE_CASES64.iter().cloned(),
-                    EDGE_CASES64.iter().cloned(),
-                    EDGE_CASES64.iter().cloned()
-                ).chain(EDGE_CASES64.iter().map(|i1| (*i1, f64(rng), f64(rng))))
-                    .chain((0..NTESTS).map(|_| (f64(&mut rng2), f64(&mut rng2), f64(&mut rng2))))
-                {
-                    let out = unsafe { $intr(i1, i2, i3) };
-
-                    let i1 = i1.to_bits();
-                    let i2 = i2.to_bits();
-                    let i3 = i3.to_bits();
-                    let out = out.to_bits();
-
-                    write!(cases, "(({}, {}, {}), {})", i1, i2, i3, out).unwrap();
-                    cases.push(',');
-                }
-
-                let mut f = File::create(concat!("tests/", stringify!($intr), ".rs"))?;
-                write!(f, "
-                    #![deny(warnings)]
-
-                    extern crate libm;
-
-                    use std::panic;
-
-                    #[test]
-                    fn {0}() {{
-                        const CASES: &[((u64, u64, u64), u64)] = &[
-                            {1}
-                        ];
-
-                        for case in CASES {{
-                            let ((i1, i2, i3), expected) = *case;
-
-                            if let Ok(outf) = panic::catch_unwind(|| {{
-                                libm::{0}(
-                                    f64::from_bits(i1),
-                                    f64::from_bits(i2),
-                                    f64::from_bits(i3),
-                                )
-                            }}) {{
-                                let outi = outf.to_bits();
-
-                                if !((outf.is_nan() && f64::from_bits(expected).is_nan())
-                                    || libm::_eq(outi, expected))
-                                {{
-                                    panic!(
-                                        \"input: {{:?}}, output: {{}}, expected: {{}}\",
-                                        (i1, i2, i3),
-                                        outi,
-                                        expected,
-                                    );
-                                }}
-                            }} else {{
-                                panic!(
-                                    \"input: {{:?}}, output: PANIC, expected: {{}}\",
-                                    (i1, i2, i3),
-                                    expected,
-                                );
-                            }}
-                        }}
-                    }}
-",
-                       stringify!($intr),
-                       cases)?;
-            )*
-
-            Ok(())
-        }
-    };
-}
-
-// fn(f64, i32) -> f64
-macro_rules! f64i32_f64 {
-    ($($intr:ident,)*) => {
-        fn f64i32_f64(rng: &mut XorShiftRng) -> Result<(), Box<Error>> {
-            extern "C" {
-                $(fn $intr(_: f64, _: i32) -> f64;)*
-            }
-
-            let mut rng2 = rng.clone();
-            $(
-                let mut cases = String::new();
-                for i1 in EDGE_CASES64.iter().cloned().chain((0..NTESTS).map(|_| f64(&mut rng2))) {
-                    let i2 = rng.gen_range(i16::MIN, i16::MAX);
-                    let out = unsafe { $intr(i1, i2 as i32) };
-
-                    let i1 = i1.to_bits();
-                    let out = out.to_bits();
-
-                    write!(cases, "(({}, {}), {})", i1, i2, out).unwrap();
-                    cases.push(',');
-                }
-
-                let mut f = File::create(concat!("tests/", stringify!($intr), ".rs"))?;
-                write!(f, "
-                    #![deny(warnings)]
-
-                    extern crate libm;
-
-                    use std::panic;
-
-                    #[test]
-                    fn {0}() {{
-                        const CASES: &[((u64, i16), u64)] = &[
-                            {1}
-                        ];
-
-                        for case in CASES {{
-                            let ((i1, i2), expected) = *case;
-
-                            if let Ok(outf) = panic::catch_unwind(|| {{
-                                libm::{0}(f64::from_bits(i1), i2 as i32)
-                            }}) {{
-                                let outi = outf.to_bits();
-
-                                if !((outf.is_nan() && f64::from_bits(expected).is_nan()) ||
-                                    libm::_eq(outi, expected)) {{
-                                    panic!(
-                                        \"input: {{:?}}, output: {{}}, expected: {{}}\",
-                                        (i1, i2),
-                                        outi,
-                                        expected,
-                                    );
-                                }}
-                            }} else {{
-                                panic!(
-                                    \"input: {{:?}}, output: PANIC, expected: {{}}\",
-                                    (i1, i2),
-                                    expected,
-                                );
-                            }}
-                        }}
-                    }}
-",
-                       stringify!($intr),
-                       cases)?;
-            )*
-
-            Ok(())
-        }
-    };
-}
-
-fn main() -> Result<(), Box<Error>> {
-    fs::remove_dir_all("tests").ok();
-    fs::create_dir("tests")?;
-
-    let mut rng = XorShiftRng::from_rng(&mut rand::thread_rng())?;
-
-    f32_f32(&mut rng)?;
-    f32f32_f32(&mut rng)?;
-    f32f32f32_f32(&mut rng)?;
-    f32i32_f32(&mut rng)?;
-    f64_f64(&mut rng)?;
-    f64f64_f64(&mut rng)?;
-    f64f64f64_f64(&mut rng)?;
-    f64i32_f64(&mut rng)?;
-
-    Ok(())
-}
-
-/* Functions to test */
-
-// With signature `fn(f32) -> f32`
-f32_f32! {
-    acosf,
-    floorf,
-    truncf,
-    asinf,
-    atanf,
-    cbrtf,
-    cosf,
-    ceilf,
-    coshf,
-    exp2f,
-    expf,
-    expm1f,
-    log10f,
-    log1pf,
-    log2f,
-    logf,
-    roundf,
-    sinf,
-    sinhf,
-    tanf,
-    tanhf,
-    fabsf,
-    sqrtf,
-}
-
-// With signature `fn(f32, f32) -> f32`
-f32f32_f32! {
-    atan2f,
-    fdimf,
-    hypotf,
-    fmodf,
-    powf,
-}
-
-// With signature `fn(f32, f32, f32) -> f32`
-f32f32f32_f32! {
-    fmaf,
-}
-
-// With signature `fn(f32, i32) -> f32`
-f32i32_f32! {
-    scalbnf,
-}
-
-// With signature `fn(f64) -> f64`
-f64_f64! {
-    acos,
-    asin,
-    atan,
-    cbrt,
-    ceil,
-    cos,
-    cosh,
-    exp,
-    exp2,
-    expm1,
-    floor,
-    log,
-    log10,
-    log1p,
-    log2,
-    round,
-    sin,
-    sinh,
-    sqrt,
-    tan,
-    tanh,
-    trunc,
-    fabs,
-}
-
-// With signature `fn(f64, f64) -> f64`
-f64f64_f64! {
-    atan2,
-    fdim,
-    fmod,
-    hypot,
-    pow,
-}
-
-// With signature `fn(f64, f64, f64) -> f64`
-f64f64f64_f64! {
-    fma,
-}
-
-// With signature `fn(f64, i32) -> f64`
-f64i32_f64! {
-    scalbn,
-}