diff --git a/library/compiler-builtins/libm/crates/libm-macros/src/lib.rs b/library/compiler-builtins/libm/crates/libm-macros/src/lib.rs
index 916b539ed58c..3cee5385b62f 100644
--- a/library/compiler-builtins/libm/crates/libm-macros/src/lib.rs
+++ b/library/compiler-builtins/libm/crates/libm-macros/src/lib.rs
@@ -79,7 +79,7 @@ pub fn base_name_enum(attributes: pm::TokenStream, tokens: pm::TokenStream) -> p
 ///         // The Rust version's return type (e.g. `(f32, f32)`)
 ///         RustRet: $RustRet:ty,
 ///         // Attributes for the current function, if any
-///         attrs: [$($meta:meta)*]
+///         attrs: [$($attr:meta),*],
 ///         // Extra tokens passed directly (if any)
 ///         extra: [$extra:ident],
 ///         // Extra function-tokens passed directly (if any)
@@ -97,6 +97,9 @@ pub fn base_name_enum(attributes: pm::TokenStream, tokens: pm::TokenStream) -> p
 ///     skip: [sin, cos],
 ///     // Attributes passed as `attrs` for specific functions. For example, here the invocation
 ///     // with `sinf` and that with `cosf` will both get `meta1` and `meta2`, but no others will.
+///     //
+///     // Note that `f16_enabled` and `f128_enabled` will always get emitted regardless of whether
+///     // or not this is specified.
 ///     attributes: [
 ///         #[meta1]
 ///         #[meta2]
@@ -255,16 +258,28 @@ fn expand(input: StructuredInput, fn_list: &[&MathOpInfo]) -> syn::Result<pm2::T
         let fn_name = Ident::new(func.name, Span::call_site());
 
         // Prepare attributes in an `attrs: ...` field
-        let meta_field = match &input.attributes {
-            Some(attrs) => {
-                let meta = attrs
-                    .iter()
-                    .filter(|map| map.names.contains(&fn_name))
-                    .flat_map(|map| &map.meta);
-                quote! { attrs: [ #( #meta )* ]  }
-            }
-            None => pm2::TokenStream::new(),
-        };
+        let mut meta_fields = Vec::new();
+        if let Some(attrs) = &input.attributes {
+            let meta_iter = attrs
+                .iter()
+                .filter(|map| map.names.contains(&fn_name))
+                .flat_map(|map| &map.meta)
+                .map(|v| v.into_token_stream());
+
+            meta_fields.extend(meta_iter);
+        }
+
+        // Always emit f16 and f128 meta so this doesn't need to be repeated everywhere
+        if func.rust_sig.args.contains(&Ty::F16) || func.rust_sig.returns.contains(&Ty::F16) {
+            let ts = quote! { cfg(f16_enabled) };
+            meta_fields.push(ts);
+        }
+        if func.rust_sig.args.contains(&Ty::F128) || func.rust_sig.returns.contains(&Ty::F128) {
+            let ts = quote! { cfg(f128_enabled) };
+            meta_fields.push(ts);
+        }
+
+        let meta_field = quote! { attrs: [ #( #meta_fields ),* ], };
 
         // Prepare extra in an `extra: ...` field, running the replacer
         let extra_field = match input.extra.clone() {
diff --git a/library/compiler-builtins/libm/crates/libm-macros/tests/basic.rs b/library/compiler-builtins/libm/crates/libm-macros/tests/basic.rs
index 2eaba04f4c67..0aa417f13c82 100644
--- a/library/compiler-builtins/libm/crates/libm-macros/tests/basic.rs
+++ b/library/compiler-builtins/libm/crates/libm-macros/tests/basic.rs
@@ -1,3 +1,5 @@
+#![feature(f16)]
+#![feature(f128)]
 // `STATUS_DLL_NOT_FOUND` on i686 MinGW, not worth looking into.
 #![cfg(not(all(target_arch = "x86", target_os = "windows", target_env = "gnu")))]
 
@@ -11,11 +13,11 @@ macro_rules! basic {
         RustFn: $RustFn:ty,
         RustArgs: $RustArgs:ty,
         RustRet: $RustRet:ty,
-        attrs: [$($meta:meta)*]
+        attrs: [$($attr:meta),*],
         extra: [$($extra_tt:tt)*],
         fn_extra: $fn_extra:expr,
     ) => {
-        $(#[$meta])*
+        $(#[$attr])*
         mod $fn_name {
             #[allow(unused)]
             type FTy= $FTy;
@@ -60,7 +62,9 @@ mod test_basic {
 macro_rules! basic_no_extra {
     (
         fn_name: $fn_name:ident,
+        attrs: [$($attr:meta),*],
     ) => {
+        $(#[$attr])*
         mod $fn_name {}
     };
 }
@@ -85,7 +89,9 @@ macro_rules! specified_types {
         fn_name: $fn_name:ident,
         RustFn: $RustFn:ty,
         RustArgs: $RustArgs:ty,
+        attrs: [$($attr:meta),*],
     ) => {
+        $(#[$attr])*
         mod $fn_name {
             #[allow(unused)]
             type RustFnTy = $RustFn;
diff --git a/library/compiler-builtins/libm/crates/libm-test/benches/random.rs b/library/compiler-builtins/libm/crates/libm-test/benches/random.rs
index b9c39334c147..06997cd3621e 100644
--- a/library/compiler-builtins/libm/crates/libm-test/benches/random.rs
+++ b/library/compiler-builtins/libm/crates/libm-test/benches/random.rs
@@ -18,9 +18,11 @@ struct MuslExtra<F> {
 macro_rules! musl_rand_benches {
     (
         fn_name: $fn_name:ident,
+        attrs: [$($attr:meta),*],
         fn_extra: $skip_on_i586:expr,
     ) => {
         paste::paste! {
+            $(#[$attr])*
             fn [< musl_bench_ $fn_name >](c: &mut Criterion) {
                 type Op = libm_test::op::$fn_name::Routine;
 
@@ -113,9 +115,11 @@ libm_macros::for_each_function! {
 macro_rules! run_callback {
     (
         fn_name: $fn_name:ident,
+        attrs: [$($attr:meta),*],
         extra: [$criterion:ident],
     ) => {
         paste::paste! {
+            $(#[$attr])*
             [< musl_bench_ $fn_name >](&mut $criterion)
         }
     };
diff --git a/library/compiler-builtins/libm/crates/libm-test/src/lib.rs b/library/compiler-builtins/libm/crates/libm-test/src/lib.rs
index fdba0357f7f0..97907b2a1607 100644
--- a/library/compiler-builtins/libm/crates/libm-test/src/lib.rs
+++ b/library/compiler-builtins/libm/crates/libm-test/src/lib.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(f16_enabled, feature(f16))]
+#![cfg_attr(f128_enabled, feature(f128))]
 #![allow(clippy::unusual_byte_groupings)] // sometimes we group by sign_exp_sig
 
 pub mod domain;
diff --git a/library/compiler-builtins/libm/crates/libm-test/src/mpfloat.rs b/library/compiler-builtins/libm/crates/libm-test/src/mpfloat.rs
index 28df916bd612..edb4cb962dcf 100644
--- a/library/compiler-builtins/libm/crates/libm-test/src/mpfloat.rs
+++ b/library/compiler-builtins/libm/crates/libm-test/src/mpfloat.rs
@@ -50,9 +50,11 @@ macro_rules! impl_mp_op {
     (
         fn_name: $fn_name:ident,
         RustFn: fn($_fty:ty,) -> $_ret:ty,
+        attrs: [$($attr:meta),*],
         fn_extra: $fn_name_normalized:expr,
     ) => {
         paste::paste! {
+            $(#[$attr])*
             impl MpOp for crate::op::$fn_name::Routine {
                 type MpTy = MpFloat;
 
@@ -72,9 +74,11 @@ macro_rules! impl_mp_op {
     (
         fn_name: $fn_name:ident,
         RustFn: fn($_fty:ty, $_fty2:ty,) -> $_ret:ty,
+        attrs: [$($attr:meta),*],
         fn_extra: $fn_name_normalized:expr,
     ) => {
         paste::paste! {
+            $(#[$attr])*
             impl MpOp for crate::op::$fn_name::Routine {
                 type MpTy = (MpFloat, MpFloat);
 
@@ -95,9 +99,11 @@ macro_rules! impl_mp_op {
     (
         fn_name: $fn_name:ident,
         RustFn: fn($_fty:ty, $_fty2:ty, $_fty3:ty,) -> $_ret:ty,
+        attrs: [$($attr:meta),*],
         fn_extra: $fn_name_normalized:expr,
     ) => {
         paste::paste! {
+            $(#[$attr])*
             impl MpOp for crate::op::$fn_name::Routine {
                 type MpTy = (MpFloat, MpFloat, MpFloat);
 
diff --git a/library/compiler-builtins/libm/crates/libm-test/src/op.rs b/library/compiler-builtins/libm/crates/libm-test/src/op.rs
index e58c28903628..ee61eb0b8406 100644
--- a/library/compiler-builtins/libm/crates/libm-test/src/op.rs
+++ b/library/compiler-builtins/libm/crates/libm-test/src/op.rs
@@ -112,8 +112,11 @@ macro_rules! do_thing {
         RustFn: $RustFn:ty,
         RustArgs: $RustArgs:ty,
         RustRet: $RustRet:ty,
+        attrs: [$($attr:meta),*],
+
     ) => {
         paste::paste! {
+            $(#[$attr])*
             pub mod $fn_name {
                 use super::*;
                 pub struct Routine;
diff --git a/library/compiler-builtins/libm/crates/libm-test/tests/check_coverage.rs b/library/compiler-builtins/libm/crates/libm-test/tests/check_coverage.rs
index 9f85d64244bf..c23298686fac 100644
--- a/library/compiler-builtins/libm/crates/libm-test/tests/check_coverage.rs
+++ b/library/compiler-builtins/libm/crates/libm-test/tests/check_coverage.rs
@@ -8,6 +8,7 @@ use std::process::Command;
 macro_rules! callback {
     (
         fn_name: $name:ident,
+        attrs: [$($attr:meta),*],
         extra: [$set:ident],
     ) => {
         let name = stringify!($name);
diff --git a/library/compiler-builtins/libm/crates/libm-test/tests/compare_built_musl.rs b/library/compiler-builtins/libm/crates/libm-test/tests/compare_built_musl.rs
index 0022ee03c210..71f080ab18f8 100644
--- a/library/compiler-builtins/libm/crates/libm-test/tests/compare_built_musl.rs
+++ b/library/compiler-builtins/libm/crates/libm-test/tests/compare_built_musl.rs
@@ -15,11 +15,11 @@ use libm_test::{CheckBasis, CheckCtx, CheckOutput, GenerateInput, MathOp, TupleC
 macro_rules! musl_rand_tests {
     (
         fn_name: $fn_name:ident,
-        attrs: [$($meta:meta)*]
+        attrs: [$($attr:meta),*],
     ) => {
         paste::paste! {
             #[test]
-            $(#[$meta])*
+            $(#[$attr])*
             fn [< musl_random_ $fn_name >]() {
                 test_one::<libm_test::op::$fn_name::Routine>(musl_math_sys::$fn_name);
             }
diff --git a/library/compiler-builtins/libm/crates/libm-test/tests/multiprecision.rs b/library/compiler-builtins/libm/crates/libm-test/tests/multiprecision.rs
index 4821f74461f3..71ff2ff965ff 100644
--- a/library/compiler-builtins/libm/crates/libm-test/tests/multiprecision.rs
+++ b/library/compiler-builtins/libm/crates/libm-test/tests/multiprecision.rs
@@ -13,11 +13,11 @@ use libm_test::{
 macro_rules! mp_rand_tests {
     (
         fn_name: $fn_name:ident,
-        attrs: [$($meta:meta)*]
+        attrs: [$($attr:meta),*],
     ) => {
         paste::paste! {
             #[test]
-            $(#[$meta])*
+            $(#[$attr])*
             fn [< mp_random_ $fn_name >]() {
                 test_one_random::<libm_test::op::$fn_name::Routine>();
             }
@@ -76,18 +76,18 @@ libm_macros::for_each_function! {
 macro_rules! mp_domain_tests {
     (
         fn_name: $fn_name:ident,
-        attrs: [$($meta:meta)*]
+        attrs: [$($attr:meta),*],
     ) => {
         paste::paste! {
             #[test]
-            $(#[$meta])*
+            $(#[$attr])*
             fn [< mp_edge_case_ $fn_name >]() {
                 type Op = libm_test::op::$fn_name::Routine;
                 domain_test_runner::<Op, _>(edge_cases::get_test_cases::<Op, _>);
             }
 
             #[test]
-            $(#[$meta])*
+            $(#[$attr])*
             fn [< mp_logspace_ $fn_name >]() {
                 type Op = libm_test::op::$fn_name::Routine;
                 domain_test_runner::<Op, _>(domain_logspace::get_test_cases::<Op>);