diff --git a/library/compiler-builtins/src/float/conv.rs b/library/compiler-builtins/src/float/conv.rs
index c0cee4373280..0e21a1ed3bfb 100644
--- a/library/compiler-builtins/src/float/conv.rs
+++ b/library/compiler-builtins/src/float/conv.rs
@@ -239,83 +239,47 @@ intrinsics! {
 // use Win64 ABI rather than unadjusted ABI. Pick the correct ABI based on the
 // llvm14-builtins-abi target feature.
 
-#[cfg(target_feature = "llvm14-builtins-abi")]
 intrinsics! {
+    #[cfg_attr(not(target_feature = "llvm14-builtins-abi"), unadjusted_on_win64)]
     pub extern "C" fn __floattisf(i: i128) -> f32 {
         int_to_float(i)
     }
 
+    #[cfg_attr(not(target_feature = "llvm14-builtins-abi"), unadjusted_on_win64)]
     pub extern "C" fn __floattidf(i: i128) -> f64 {
         int_to_float(i)
     }
 
+    #[cfg_attr(not(target_feature = "llvm14-builtins-abi"), unadjusted_on_win64)]
     pub extern "C" fn __floatuntisf(i: u128) -> f32 {
         int_to_float(i)
     }
 
+    #[cfg_attr(not(target_feature = "llvm14-builtins-abi"), unadjusted_on_win64)]
     pub extern "C" fn __floatuntidf(i: u128) -> f64 {
         int_to_float(i)
     }
 
-    #[win64_128bit_abi_hack]
+    #[cfg_attr(target_feature = "llvm14-builtins-abi", win64_128bit_abi_hack)]
+    #[cfg_attr(not(target_feature = "llvm14-builtins-abi"), unadjusted_on_win64)]
     pub extern "C" fn __fixsfti(f: f32) -> i128 {
         float_to_int(f)
     }
 
-    #[win64_128bit_abi_hack]
+    #[cfg_attr(target_feature = "llvm14-builtins-abi", win64_128bit_abi_hack)]
+    #[cfg_attr(not(target_feature = "llvm14-builtins-abi"), unadjusted_on_win64)]
     pub extern "C" fn __fixdfti(f: f64) -> i128 {
         float_to_int(f)
     }
 
-    #[win64_128bit_abi_hack]
+    #[cfg_attr(target_feature = "llvm14-builtins-abi", win64_128bit_abi_hack)]
+    #[cfg_attr(not(target_feature = "llvm14-builtins-abi"), unadjusted_on_win64)]
     pub extern "C" fn __fixunssfti(f: f32) -> u128 {
         float_to_int(f)
     }
 
-    #[win64_128bit_abi_hack]
-    pub extern "C" fn __fixunsdfti(f: f64) -> u128 {
-        float_to_int(f)
-    }
-}
-
-#[cfg(not(target_feature = "llvm14-builtins-abi"))]
-intrinsics! {
-    #[unadjusted_on_win64]
-    pub extern "C" fn __floattisf(i: i128) -> f32 {
-        int_to_float(i)
-    }
-
-    #[unadjusted_on_win64]
-    pub extern "C" fn __floattidf(i: i128) -> f64 {
-        int_to_float(i)
-    }
-
-    #[unadjusted_on_win64]
-    pub extern "C" fn __floatuntisf(i: u128) -> f32 {
-        int_to_float(i)
-    }
-
-    #[unadjusted_on_win64]
-    pub extern "C" fn __floatuntidf(i: u128) -> f64 {
-        int_to_float(i)
-    }
-
-    #[unadjusted_on_win64]
-    pub extern "C" fn __fixsfti(f: f32) -> i128 {
-        float_to_int(f)
-    }
-
-    #[unadjusted_on_win64]
-    pub extern "C" fn __fixdfti(f: f64) -> i128 {
-        float_to_int(f)
-    }
-
-    #[unadjusted_on_win64]
-    pub extern "C" fn __fixunssfti(f: f32) -> u128 {
-        float_to_int(f)
-    }
-
-    #[unadjusted_on_win64]
+    #[cfg_attr(target_feature = "llvm14-builtins-abi", win64_128bit_abi_hack)]
+    #[cfg_attr(not(target_feature = "llvm14-builtins-abi"), unadjusted_on_win64)]
     pub extern "C" fn __fixunsdfti(f: f64) -> u128 {
         float_to_int(f)
     }
diff --git a/library/compiler-builtins/src/macros.rs b/library/compiler-builtins/src/macros.rs
index 6926feac055c..22d82e3fab95 100644
--- a/library/compiler-builtins/src/macros.rs
+++ b/library/compiler-builtins/src/macros.rs
@@ -61,6 +61,35 @@ macro_rules! public_test_dep {
 macro_rules! intrinsics {
     () => ();
 
+    // Support cfg_attr:
+    (
+        #[cfg_attr($e:meta, $($attr:tt)*)]
+        $(#[$($attrs:tt)*])*
+        pub extern $abi:tt fn $name:ident( $($argname:ident: $ty:ty),* ) $(-> $ret:ty)? {
+            $($body:tt)*
+        }
+        $($rest:tt)*
+    ) => (
+        #[cfg($e)]
+        intrinsics! {
+            #[$($attr)*]
+            $(#[$($attrs)*])*
+            pub extern $abi fn $name($($argname: $ty),*) $(-> $ret)? {
+                $($body)*
+            }
+        }
+
+        #[cfg(not($e))]
+        intrinsics! {
+            $(#[$($attrs)*])*
+            pub extern $abi fn $name($($argname: $ty),*) $(-> $ret)? {
+                $($body)*
+            }
+        }
+
+        intrinsics!($($rest)*);
+    );
+
     // Right now there's a bunch of architecture-optimized intrinsics in the
     // stock compiler-rt implementation. Not all of these have been ported over
     // to Rust yet so when the `c` feature of this crate is enabled we fall back