diff --git a/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/Cargo.toml b/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/Cargo.toml
deleted file mode 100644
index 38a5116690a7..000000000000
--- a/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/Cargo.toml
+++ /dev/null
@@ -1,38 +0,0 @@
-[package]
-name = "cb"
-version = "0.1.0"
-authors = ["Jorge Aparicio <jorge@japaric.io>"]
-edition = "2021"
-publish = false
-
-[lib]
-crate-type = ["staticlib"]
-test = false
-bench = false
-
-[features]
-default = ["arch", "compiler-builtins", "unstable-float"]
-
-# Copied from `libm`'s root `Cargo.toml`'
-arch = []
-compiler-builtins = []
-unstable-float = []
-
-[lints.rust]
-unexpected_cfgs = { level = "warn", check-cfg = [
-  "cfg(arch_enabled)",
-  "cfg(assert_no_panic)",
-  "cfg(intrinsics_enabled)",
-  'cfg(feature, values("force-soft-floats"))',
-  'cfg(feature, values("unstable"))',
-  'cfg(feature, values("unstable-intrinsics"))',
-  'cfg(feature, values("unstable-public-internals"))',
-] }
-
-[profile.dev]
-panic = "abort"
-
-[profile.release]
-panic = "abort"
-codegen-units = 1
-lto = "fat"
diff --git a/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/build.rs b/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/build.rs
deleted file mode 100644
index ef8d613c9f45..000000000000
--- a/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/build.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-#[path = "../../libm/configure.rs"]
-mod configure;
-
-fn main() {
-    println!("cargo:rerun-if-changed=../../libm/configure.rs");
-    let cfg = configure::Config::from_env();
-    configure::emit_libm_config(&cfg);
-}
diff --git a/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/src/lib.rs b/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/src/lib.rs
deleted file mode 100644
index e70f6d9e04c9..000000000000
--- a/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/src/lib.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-//! Fake compiler-builtins crate
-//!
-//! This is used to test that we can source import `libm` into the compiler-builtins crate.
-//! Additionally, it provides a `#[no_mangle]` C API that can be easier to inspect than the
-//! default `.rlib`.
-
-#![compiler_builtins]
-#![feature(core_intrinsics)]
-#![feature(compiler_builtins)]
-#![feature(f16)]
-#![feature(f128)]
-#![allow(internal_features)]
-#![no_std]
-
-mod math;
-// Required for macro paths.
-use math::libm::support;
diff --git a/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/src/math.rs b/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/src/math.rs
deleted file mode 100644
index 58a5bfbb90f9..000000000000
--- a/library/compiler-builtins/libm/crates/compiler-builtins-smoke-test/src/math.rs
+++ /dev/null
@@ -1,182 +0,0 @@
-use core::ffi::c_int;
-
-#[allow(dead_code)]
-#[allow(clippy::all)] // We don't get `libm`'s list of `allow`s, so just ignore Clippy.
-#[allow(unused_imports)]
-#[path = "../../../libm/src/math/mod.rs"]
-pub mod libm;
-
-/// Mark functions `#[no_mangle]` and with the C ABI.
-macro_rules! no_mangle {
-    ($( $name:ident( $($tt:tt)+ ) -> $ret:ty; )+) => {
-        $( no_mangle!(@inner $name( $($tt)+ ) -> $ret); )+
-    };
-
-    // Handle simple functions with single return types
-    (@inner $name:ident( $($arg:ident: $aty:ty),+ ) -> $ret:ty) => {
-        #[unsafe(no_mangle)]
-        extern "C" fn $name($($arg: $aty),+) -> $ret {
-            libm::$name($($arg),+)
-        }
-    };
-
-
-    // Functions with `&mut` return values need to be handled differently, use `|` to
-    // separate inputs vs. outputs.
-    (
-        @inner $name:ident( $($arg:ident: $aty:ty),+ | $($rarg:ident: $rty:ty),+) -> $ret:ty
-    ) => {
-        #[unsafe(no_mangle)]
-        extern "C" fn $name($($arg: $aty,)+ $($rarg: $rty),+) -> $ret {
-            let ret;
-            (ret, $(*$rarg),+) = libm::$name($($arg),+);
-            ret
-        }
-    };
-}
-
-no_mangle! {
-    frexp(x: f64 | y: &mut c_int) -> f64;
-    frexpf(x: f32 | y: &mut c_int) -> f32;
-    acos(x: f64) -> f64;
-    acosf(x: f32) -> f32;
-    acosh(x: f64) -> f64;
-    acoshf(x: f32) -> f32;
-    asin(x: f64) -> f64;
-    asinf(x: f32) -> f32;
-    asinh(x: f64) -> f64;
-    asinhf(x: f32) -> f32;
-    atan(x: f64) -> f64;
-    atan2(x: f64, y: f64) -> f64;
-    atan2f(x: f32, y: f32) -> f32;
-    atanf(x: f32) -> f32;
-    atanh(x: f64) -> f64;
-    atanhf(x: f32) -> f32;
-    cbrt(x: f64) -> f64;
-    cbrtf(x: f32) -> f32;
-    ceil(x: f64) -> f64;
-    ceilf(x: f32) -> f32;
-    ceilf128(x: f128) -> f128;
-    ceilf16(x: f16) -> f16;
-    copysign(x: f64, y: f64) -> f64;
-    copysignf(x: f32, y: f32) -> f32;
-    copysignf128(x: f128, y: f128) -> f128;
-    copysignf16(x: f16, y: f16) -> f16;
-    cos(x: f64) -> f64;
-    cosf(x: f32) -> f32;
-    cosh(x: f64) -> f64;
-    coshf(x: f32) -> f32;
-    erf(x: f64) -> f64;
-    erfc(x: f64) -> f64;
-    erfcf(x: f32) -> f32;
-    erff(x: f32) -> f32;
-    exp(x: f64) -> f64;
-    exp10(x: f64) -> f64;
-    exp10f(x: f32) -> f32;
-    exp2(x: f64) -> f64;
-    exp2f(x: f32) -> f32;
-    expf(x: f32) -> f32;
-    expm1(x: f64) -> f64;
-    expm1f(x: f32) -> f32;
-    fabs(x: f64) -> f64;
-    fabsf(x: f32) -> f32;
-    fabsf128(x: f128) -> f128;
-    fabsf16(x: f16) -> f16;
-    fdim(x: f64, y: f64) -> f64;
-    fdimf(x: f32, y: f32) -> f32;
-    fdimf128(x: f128, y: f128) -> f128;
-    fdimf16(x: f16, y: f16) -> f16;
-    floor(x: f64) -> f64;
-    floorf(x: f32) -> f32;
-    floorf128(x: f128) -> f128;
-    floorf16(x: f16) -> f16;
-    fma(x: f64, y: f64, z: f64) -> f64;
-    fmaf(x: f32, y: f32, z: f32) -> f32;
-    fmax(x: f64, y: f64) -> f64;
-    fmaxf(x: f32, y: f32) -> f32;
-    fmin(x: f64, y: f64) -> f64;
-    fminf(x: f32, y: f32) -> f32;
-    fmod(x: f64, y: f64) -> f64;
-    fmodf(x: f32, y: f32) -> f32;
-    hypot(x: f64, y: f64) -> f64;
-    hypotf(x: f32, y: f32) -> f32;
-    ilogb(x: f64) -> c_int;
-    ilogbf(x: f32) -> c_int;
-    j0(x: f64) -> f64;
-    j0f(x: f32) -> f32;
-    j1(x: f64) -> f64;
-    j1f(x: f32) -> f32;
-    jn(x: c_int, y: f64) -> f64;
-    jnf(x: c_int, y: f32) -> f32;
-    ldexp(x: f64, y: c_int) -> f64;
-    ldexpf(x: f32, y: c_int) -> f32;
-    lgamma(x: f64) -> f64;
-    lgamma_r(x: f64 | r: &mut c_int) -> f64;
-    lgammaf(x: f32) -> f32;
-    lgammaf_r(x: f32 | r: &mut c_int) -> f32;
-    log(x: f64) -> f64;
-    log10(x: f64) -> f64;
-    log10f(x: f32) -> f32;
-    log1p(x: f64) -> f64;
-    log1pf(x: f32) -> f32;
-    log2(x: f64) -> f64;
-    log2f(x: f32) -> f32;
-    logf(x: f32) -> f32;
-    modf(x: f64 | r: &mut f64) -> f64;
-    modff(x: f32 | r: &mut f32) -> f32;
-    nextafter(x: f64, y: f64) -> f64;
-    nextafterf(x: f32, y: f32) -> f32;
-    pow(x: f64, y: f64) -> f64;
-    powf(x: f32, y: f32) -> f32;
-    remainder(x: f64, y: f64) -> f64;
-    remainderf(x: f32, y: f32) -> f32;
-    remquo(x: f64, y: f64 | q: &mut c_int) -> f64;
-    remquof(x: f32, y: f32 | q: &mut c_int) -> f32;
-    rint(x: f64) -> f64;
-    rintf(x: f32) -> f32;
-    rintf128(x: f128) -> f128;
-    rintf16(x: f16) -> f16;
-    round(x: f64) -> f64;
-    roundf(x: f32) -> f32;
-    scalbn(x: f64, y: c_int) -> f64;
-    scalbnf(x: f32, y: c_int) -> f32;
-    sin(x: f64) -> f64;
-    sinf(x: f32) -> f32;
-    sinh(x: f64) -> f64;
-    sinhf(x: f32) -> f32;
-    sqrt(x: f64) -> f64;
-    sqrtf(x: f32) -> f32;
-    tan(x: f64) -> f64;
-    tanf(x: f32) -> f32;
-    tanh(x: f64) -> f64;
-    tanhf(x: f32) -> f32;
-    tgamma(x: f64) -> f64;
-    tgammaf(x: f32) -> f32;
-    trunc(x: f64) -> f64;
-    truncf(x: f32) -> f32;
-    truncf128(x: f128) -> f128;
-    truncf16(x: f16) -> f16;
-    y0(x: f64) -> f64;
-    y0f(x: f32) -> f32;
-    y1(x: f64) -> f64;
-    y1f(x: f32) -> f32;
-    yn(x: c_int, y: f64) -> f64;
-    ynf(x: c_int, y: f32) -> f32;
-}
-
-/* sincos has no direct return type, not worth handling in the macro */
-
-#[unsafe(no_mangle)]
-extern "C" fn sincos(x: f64, s: &mut f64, c: &mut f64) {
-    (*s, *c) = libm::sincos(x);
-}
-
-#[unsafe(no_mangle)]
-extern "C" fn sincosf(x: f32, s: &mut f32, c: &mut f32) {
-    (*s, *c) = libm::sincosf(x);
-}
-
-#[panic_handler]
-fn panic(_info: &core::panic::PanicInfo) -> ! {
-    loop {}
-}