diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index edf4396c8..50557c4bb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -230,42 +230,6 @@ jobs:
             --workspace --exclude futures-test \
             --features unstable --ignore-unknown-features
 
-  # When this job failed, run ci/no_atomic_cas.sh and commit result changes.
-  codegen:
-    runs-on: ubuntu-latest
-    permissions:
-      contents: write
-      pull-requests: write
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Rust
-        run: rustup update nightly && rustup default nightly
-      - run: ci/no_atomic_cas.sh
-      - run: git add -N . && git diff --exit-code
-        if: github.repository_owner != 'rust-lang' || github.event_name != 'schedule'
-      - id: diff
-        run: |
-          git config user.name "Taiki Endo"
-          git config user.email "te316e89@gmail.com"
-          git add -N .
-          if ! git diff --exit-code; then
-              git add .
-              git commit -m "Update no_atomic_cas.rs"
-              echo "::set-output name=success::false"
-          fi
-        if: github.repository_owner == 'rust-lang' && github.event_name == 'schedule'
-      - uses: peter-evans/create-pull-request@v5
-        with:
-          title: Update no_atomic_cas.rs
-          body: |
-            Auto-generated by [create-pull-request][1]
-            [Please close and immediately reopen this pull request to run CI.][2]
-
-            [1]: https://github.com/peter-evans/create-pull-request
-            [2]: https://github.com/peter-evans/create-pull-request/blob/HEAD/docs/concepts-guidelines.md#workarounds-to-trigger-further-workflow-runs
-          branch: update-no-atomic-cas-rs
-        if: github.repository_owner == 'rust-lang' && github.event_name == 'schedule' && steps.diff.outputs.success == 'false'
-
   miri:
     name: cargo miri test
     runs-on: ubuntu-latest
diff --git a/ci/no_atomic_cas.sh b/ci/no_atomic_cas.sh
deleted file mode 100755
index ba0200d69..000000000
--- a/ci/no_atomic_cas.sh
+++ /dev/null
@@ -1,31 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-IFS=$'\n\t'
-cd "$(dirname "$0")"/..
-
-# Update the list of targets that do not support atomic CAS operations.
-#
-# Usage:
-#    ./ci/no_atomic_cas.sh
-
-file="no_atomic_cas.rs"
-
-no_atomic_cas=()
-for target in $(rustc --print target-list); do
-    target_spec=$(rustc --print target-spec-json -Z unstable-options --target "${target}")
-    res=$(jq <<<"${target_spec}" -r 'select(."atomic-cas" == false)')
-    [[ -z "${res}" ]] || no_atomic_cas+=("${target}")
-done
-
-cat >"${file}" <<EOF
-// This file is @generated by $(basename "$0").
-// It is not intended for manual editing.
-
-const NO_ATOMIC_CAS: &[&str] = &[
-EOF
-for target in "${no_atomic_cas[@]}"; do
-    echo "    \"${target}\"," >>"${file}"
-done
-cat >>"${file}" <<EOF
-];
-EOF
diff --git a/futures-channel/build.rs b/futures-channel/build.rs
deleted file mode 100644
index 05e0496d9..000000000
--- a/futures-channel/build.rs
+++ /dev/null
@@ -1,41 +0,0 @@
-// The rustc-cfg listed below are considered public API, but it is *unstable*
-// and outside of the normal semver guarantees:
-//
-// - `futures_no_atomic_cas`
-//      Assume the target does *not* support atomic CAS operations.
-//      This is usually detected automatically by the build script, but you may
-//      need to enable it manually when building for custom targets or using
-//      non-cargo build systems that don't run the build script.
-//
-// With the exceptions mentioned above, the rustc-cfg emitted by the build
-// script are *not* public API.
-
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
-fn main() {
-    let target = match env::var("TARGET") {
-        Ok(target) => target,
-        Err(e) => {
-            println!(
-                "cargo:warning={}: unable to get TARGET environment variable: {}",
-                env!("CARGO_PKG_NAME"),
-                e
-            );
-            return;
-        }
-    };
-
-    // Note that this is `no_*`, not `has_*`. This allows treating
-    // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
-    // run. This is needed for compatibility with non-cargo build systems that
-    // don't run the build script.
-    if NO_ATOMIC_CAS.contains(&&*target) {
-        println!("cargo:rustc-cfg=futures_no_atomic_cas");
-    }
-
-    println!("cargo:rerun-if-changed=no_atomic_cas.rs");
-}
diff --git a/futures-channel/no_atomic_cas.rs b/futures-channel/no_atomic_cas.rs
deleted file mode 120000
index 3d7380fad..000000000
--- a/futures-channel/no_atomic_cas.rs
+++ /dev/null
@@ -1 +0,0 @@
-../no_atomic_cas.rs
\ No newline at end of file
diff --git a/futures-channel/src/lib.rs b/futures-channel/src/lib.rs
index 4cd936d55..f611e6b9f 100644
--- a/futures-channel/src/lib.rs
+++ b/futures-channel/src/lib.rs
@@ -27,16 +27,16 @@
     )
 ))]
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 extern crate alloc;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod lock;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "std")]
 pub mod mpsc;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub mod oneshot;
diff --git a/futures-core/build.rs b/futures-core/build.rs
deleted file mode 100644
index 05e0496d9..000000000
--- a/futures-core/build.rs
+++ /dev/null
@@ -1,41 +0,0 @@
-// The rustc-cfg listed below are considered public API, but it is *unstable*
-// and outside of the normal semver guarantees:
-//
-// - `futures_no_atomic_cas`
-//      Assume the target does *not* support atomic CAS operations.
-//      This is usually detected automatically by the build script, but you may
-//      need to enable it manually when building for custom targets or using
-//      non-cargo build systems that don't run the build script.
-//
-// With the exceptions mentioned above, the rustc-cfg emitted by the build
-// script are *not* public API.
-
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
-fn main() {
-    let target = match env::var("TARGET") {
-        Ok(target) => target,
-        Err(e) => {
-            println!(
-                "cargo:warning={}: unable to get TARGET environment variable: {}",
-                env!("CARGO_PKG_NAME"),
-                e
-            );
-            return;
-        }
-    };
-
-    // Note that this is `no_*`, not `has_*`. This allows treating
-    // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
-    // run. This is needed for compatibility with non-cargo build systems that
-    // don't run the build script.
-    if NO_ATOMIC_CAS.contains(&&*target) {
-        println!("cargo:rustc-cfg=futures_no_atomic_cas");
-    }
-
-    println!("cargo:rerun-if-changed=no_atomic_cas.rs");
-}
diff --git a/futures-core/no_atomic_cas.rs b/futures-core/no_atomic_cas.rs
deleted file mode 120000
index 3d7380fad..000000000
--- a/futures-core/no_atomic_cas.rs
+++ /dev/null
@@ -1 +0,0 @@
-../no_atomic_cas.rs
\ No newline at end of file
diff --git a/futures-core/src/task/__internal/mod.rs b/futures-core/src/task/__internal/mod.rs
index 377f3e286..c24874228 100644
--- a/futures-core/src/task/__internal/mod.rs
+++ b/futures-core/src/task/__internal/mod.rs
@@ -1,4 +1,7 @@
-#[cfg(any(not(futures_no_atomic_cas), feature = "portable-atomic"))]
+#[cfg_attr(target_os = "none", cfg(any(target_has_atomic = "ptr", feature = "portable-atomic")))]
 mod atomic_waker;
-#[cfg(any(not(futures_no_atomic_cas), feature = "portable-atomic"))]
+#[cfg_attr(
+    target_os = "none",
+    cfg(any(target_has_atomic = "ptr", feature = "portable-atomic"))
+)]
 pub use self::atomic_waker::AtomicWaker;
diff --git a/futures-task/build.rs b/futures-task/build.rs
deleted file mode 100644
index 05e0496d9..000000000
--- a/futures-task/build.rs
+++ /dev/null
@@ -1,41 +0,0 @@
-// The rustc-cfg listed below are considered public API, but it is *unstable*
-// and outside of the normal semver guarantees:
-//
-// - `futures_no_atomic_cas`
-//      Assume the target does *not* support atomic CAS operations.
-//      This is usually detected automatically by the build script, but you may
-//      need to enable it manually when building for custom targets or using
-//      non-cargo build systems that don't run the build script.
-//
-// With the exceptions mentioned above, the rustc-cfg emitted by the build
-// script are *not* public API.
-
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
-fn main() {
-    let target = match env::var("TARGET") {
-        Ok(target) => target,
-        Err(e) => {
-            println!(
-                "cargo:warning={}: unable to get TARGET environment variable: {}",
-                env!("CARGO_PKG_NAME"),
-                e
-            );
-            return;
-        }
-    };
-
-    // Note that this is `no_*`, not `has_*`. This allows treating
-    // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
-    // run. This is needed for compatibility with non-cargo build systems that
-    // don't run the build script.
-    if NO_ATOMIC_CAS.contains(&&*target) {
-        println!("cargo:rustc-cfg=futures_no_atomic_cas");
-    }
-
-    println!("cargo:rerun-if-changed=no_atomic_cas.rs");
-}
diff --git a/futures-task/no_atomic_cas.rs b/futures-task/no_atomic_cas.rs
deleted file mode 120000
index 3d7380fad..000000000
--- a/futures-task/no_atomic_cas.rs
+++ /dev/null
@@ -1 +0,0 @@
-../no_atomic_cas.rs
\ No newline at end of file
diff --git a/futures-task/src/lib.rs b/futures-task/src/lib.rs
index c72460744..33896d8b1 100644
--- a/futures-task/src/lib.rs
+++ b/futures-task/src/lib.rs
@@ -18,24 +18,24 @@ extern crate alloc;
 mod spawn;
 pub use crate::spawn::{LocalSpawn, Spawn, SpawnError};
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod arc_wake;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use crate::arc_wake::ArcWake;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod waker;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use crate::waker::waker;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod waker_ref;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use crate::waker_ref::{waker_ref, WakerRef};
 
diff --git a/futures-task/src/spawn.rs b/futures-task/src/spawn.rs
index f4e63397b..4a9a45a44 100644
--- a/futures-task/src/spawn.rs
+++ b/futures-task/src/spawn.rs
@@ -168,7 +168,7 @@ mod if_alloc {
         }
     }
 
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     impl<Sp: ?Sized + Spawn> Spawn for alloc::sync::Arc<Sp> {
         fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError> {
             (**self).spawn_obj(future)
@@ -179,7 +179,7 @@ mod if_alloc {
         }
     }
 
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     impl<Sp: ?Sized + LocalSpawn> LocalSpawn for alloc::sync::Arc<Sp> {
         fn spawn_local_obj(&self, future: LocalFutureObj<'static, ()>) -> Result<(), SpawnError> {
             (**self).spawn_local_obj(future)
diff --git a/futures-util/build.rs b/futures-util/build.rs
deleted file mode 100644
index 05e0496d9..000000000
--- a/futures-util/build.rs
+++ /dev/null
@@ -1,41 +0,0 @@
-// The rustc-cfg listed below are considered public API, but it is *unstable*
-// and outside of the normal semver guarantees:
-//
-// - `futures_no_atomic_cas`
-//      Assume the target does *not* support atomic CAS operations.
-//      This is usually detected automatically by the build script, but you may
-//      need to enable it manually when building for custom targets or using
-//      non-cargo build systems that don't run the build script.
-//
-// With the exceptions mentioned above, the rustc-cfg emitted by the build
-// script are *not* public API.
-
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
-fn main() {
-    let target = match env::var("TARGET") {
-        Ok(target) => target,
-        Err(e) => {
-            println!(
-                "cargo:warning={}: unable to get TARGET environment variable: {}",
-                env!("CARGO_PKG_NAME"),
-                e
-            );
-            return;
-        }
-    };
-
-    // Note that this is `no_*`, not `has_*`. This allows treating
-    // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
-    // run. This is needed for compatibility with non-cargo build systems that
-    // don't run the build script.
-    if NO_ATOMIC_CAS.contains(&&*target) {
-        println!("cargo:rustc-cfg=futures_no_atomic_cas");
-    }
-
-    println!("cargo:rerun-if-changed=no_atomic_cas.rs");
-}
diff --git a/futures-util/no_atomic_cas.rs b/futures-util/no_atomic_cas.rs
deleted file mode 120000
index 3d7380fad..000000000
--- a/futures-util/no_atomic_cas.rs
+++ /dev/null
@@ -1 +0,0 @@
-../no_atomic_cas.rs
\ No newline at end of file
diff --git a/futures-util/src/future/join_all.rs b/futures-util/src/future/join_all.rs
index 11b6f2728..79eee8dff 100644
--- a/futures-util/src/future/join_all.rs
+++ b/futures-util/src/future/join_all.rs
@@ -12,7 +12,7 @@ use core::task::{Context, Poll};
 
 use super::{assert_future, MaybeDone};
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 use crate::stream::{Collect, FuturesOrdered, StreamExt};
 
 pub(crate) fn iter_pin_mut<T>(slice: Pin<&mut [T]>) -> impl Iterator<Item = Pin<&mut T>> {
@@ -31,7 +31,7 @@ where
     kind: JoinAllKind<F>,
 }
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 pub(crate) const SMALL: usize = 30;
 
 enum JoinAllKind<F>
@@ -41,7 +41,7 @@ where
     Small {
         elems: Pin<Box<[MaybeDone<F>]>>,
     },
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     Big {
         fut: Collect<FuturesOrdered<F>, Vec<F::Output>>,
     },
@@ -57,7 +57,7 @@ where
             JoinAllKind::Small { ref elems } => {
                 f.debug_struct("JoinAll").field("elems", elems).finish()
             }
-            #[cfg(not(futures_no_atomic_cas))]
+            #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
             JoinAllKind::Big { ref fut, .. } => fmt::Debug::fmt(fut, f),
         }
     }
@@ -106,7 +106,8 @@ where
 {
     let iter = iter.into_iter();
 
-    #[cfg(futures_no_atomic_cas)]
+    #[cfg(target_os = "none")]
+    #[cfg_attr(target_os = "none", cfg(not(target_has_atomic = "ptr")))]
     {
         let kind =
             JoinAllKind::Small { elems: iter.map(MaybeDone::Future).collect::<Box<[_]>>().into() };
@@ -114,7 +115,7 @@ where
         assert_future::<Vec<<I::Item as Future>::Output>, _>(JoinAll { kind })
     }
 
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     {
         let kind = match iter.size_hint().1 {
             Some(max) if max <= SMALL => JoinAllKind::Small {
@@ -153,7 +154,7 @@ where
                     Poll::Pending
                 }
             }
-            #[cfg(not(futures_no_atomic_cas))]
+            #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
             JoinAllKind::Big { fut } => Pin::new(fut).poll(cx),
         }
     }
diff --git a/futures-util/src/future/mod.rs b/futures-util/src/future/mod.rs
index 374e36512..2d8fa4f65 100644
--- a/futures-util/src/future/mod.rs
+++ b/futures-util/src/future/mod.rs
@@ -111,13 +111,13 @@ pub use self::select_ok::{select_ok, SelectOk};
 mod either;
 pub use self::either::Either;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod abortable;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use crate::abortable::{AbortHandle, AbortRegistration, Abortable, Aborted};
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use abortable::abortable;
 
diff --git a/futures-util/src/future/try_join_all.rs b/futures-util/src/future/try_join_all.rs
index 506f45065..2d6a2a02c 100644
--- a/futures-util/src/future/try_join_all.rs
+++ b/futures-util/src/future/try_join_all.rs
@@ -12,7 +12,7 @@ use core::task::{Context, Poll};
 
 use super::{assert_future, join_all, IntoFuture, TryFuture, TryMaybeDone};
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 use crate::stream::{FuturesOrdered, TryCollect, TryStreamExt};
 use crate::TryFutureExt;
 
@@ -38,7 +38,7 @@ where
     Small {
         elems: Pin<Box<[TryMaybeDone<IntoFuture<F>>]>>,
     },
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     Big {
         fut: TryCollect<FuturesOrdered<IntoFuture<F>>, Vec<F::Ok>>,
     },
@@ -56,7 +56,7 @@ where
             TryJoinAllKind::Small { ref elems } => {
                 f.debug_struct("TryJoinAll").field("elems", elems).finish()
             }
-            #[cfg(not(futures_no_atomic_cas))]
+            #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
             TryJoinAllKind::Big { ref fut, .. } => fmt::Debug::fmt(fut, f),
         }
     }
@@ -121,7 +121,8 @@ where
 {
     let iter = iter.into_iter().map(TryFutureExt::into_future);
 
-    #[cfg(futures_no_atomic_cas)]
+    #[cfg(target_os = "none")]
+    #[cfg_attr(target_os = "none", cfg(not(target_has_atomic = "ptr")))]
     {
         let kind = TryJoinAllKind::Small {
             elems: iter.map(TryMaybeDone::Future).collect::<Box<[_]>>().into(),
@@ -132,7 +133,7 @@ where
         )
     }
 
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     {
         let kind = match iter.size_hint().1 {
             Some(max) if max <= join_all::SMALL => TryJoinAllKind::Small {
@@ -184,7 +185,7 @@ where
                     }
                 }
             }
-            #[cfg(not(futures_no_atomic_cas))]
+            #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
             TryJoinAllKind::Big { fut } => Pin::new(fut).poll(cx),
         }
     }
diff --git a/futures-util/src/lib.rs b/futures-util/src/lib.rs
index 9a10c93c9..208eb73aa 100644
--- a/futures-util/src/lib.rs
+++ b/futures-util/src/lib.rs
@@ -329,7 +329,7 @@ pub use crate::io::{
 #[cfg(feature = "alloc")]
 pub mod lock;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod abortable;
 
diff --git a/futures-util/src/lock/mod.rs b/futures-util/src/lock/mod.rs
index 0be72717c..8ca0ff625 100644
--- a/futures-util/src/lock/mod.rs
+++ b/futures-util/src/lock/mod.rs
@@ -3,25 +3,25 @@
 //! This module is only available when the `std` or `alloc` feature of this
 //! library is activated, and it is activated by default.
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(any(feature = "sink", feature = "io"))]
 #[cfg(not(feature = "bilock"))]
 pub(crate) use self::bilock::BiLock;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "bilock")]
 #[cfg_attr(docsrs, doc(cfg(feature = "bilock")))]
 pub use self::bilock::{BiLock, BiLockAcquire, BiLockGuard, ReuniteError};
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "std")]
 pub use self::mutex::{
     MappedMutexGuard, Mutex, MutexGuard, MutexLockFuture, OwnedMutexGuard, OwnedMutexLockFuture,
 };
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(any(feature = "bilock", feature = "sink", feature = "io"))]
 #[cfg_attr(docsrs, doc(cfg(feature = "bilock")))]
 #[cfg_attr(not(feature = "bilock"), allow(unreachable_pub))]
 mod bilock;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "std")]
 mod mutex;
diff --git a/futures-util/src/stream/mod.rs b/futures-util/src/stream/mod.rs
index 92a3724b4..2438e58b6 100644
--- a/futures-util/src/stream/mod.rs
+++ b/futures-util/src/stream/mod.rs
@@ -37,13 +37,13 @@ pub use self::stream::ReadyChunks;
 #[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
 pub use self::stream::Forward;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use self::stream::{
     BufferUnordered, Buffered, FlatMapUnordered, FlattenUnordered, ForEachConcurrent,
 };
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "sink")]
 #[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
 #[cfg(feature = "alloc")]
@@ -61,7 +61,7 @@ pub use self::try_stream::{
 #[cfg(feature = "std")]
 pub use self::try_stream::IntoAsyncRead;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use self::try_stream::{
     TryBufferUnordered, TryBuffered, TryFlattenUnordered, TryForEachConcurrent,
@@ -105,36 +105,36 @@ pub use self::select_with_strategy::{select_with_strategy, PollNext, SelectWithS
 mod unfold;
 pub use self::unfold::{unfold, Unfold};
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod futures_ordered;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use self::futures_ordered::FuturesOrdered;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub mod futures_unordered;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[doc(inline)]
 pub use self::futures_unordered::FuturesUnordered;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub mod select_all;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[doc(inline)]
 pub use self::select_all::{select_all, SelectAll};
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod abortable;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use crate::abortable::{AbortHandle, AbortRegistration, Abortable, Aborted};
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use abortable::abortable;
 
diff --git a/futures-util/src/stream/stream/mod.rs b/futures-util/src/stream/stream/mod.rs
index 3978d188f..2da7036b2 100644
--- a/futures-util/src/stream/stream/mod.rs
+++ b/futures-util/src/stream/stream/mod.rs
@@ -181,32 +181,32 @@ mod scan;
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::scan::Scan;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod buffer_unordered;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::buffer_unordered::BufferUnordered;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod buffered;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::buffered::Buffered;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub(crate) mod flatten_unordered;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[allow(unreachable_pub)]
 pub use self::flatten_unordered::FlattenUnordered;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 delegate_all!(
     /// Stream for the [`flat_map_unordered`](StreamExt::flat_map_unordered) method.
@@ -216,20 +216,20 @@ delegate_all!(
     where St: Stream, U: Stream, U: Unpin, F: FnMut(St::Item) -> U
 );
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod for_each_concurrent;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::for_each_concurrent::ForEachConcurrent;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "sink")]
 #[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
 #[cfg(feature = "alloc")]
 mod split;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "sink")]
 #[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
 #[cfg(feature = "alloc")]
@@ -820,7 +820,7 @@ pub trait StreamExt: Stream {
     /// assert_eq!(output, vec![1, 2, 3, 4]);
     /// # });
     /// ```
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn flatten_unordered(self, limit: impl Into<Option<usize>>) -> FlattenUnordered<Self>
     where
@@ -902,7 +902,7 @@ pub trait StreamExt: Stream {
     /// assert_eq!(vec![1usize, 2, 2, 3, 3, 3, 4, 4, 4, 4], values);
     /// # });
     /// ```
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn flat_map_unordered<U, F>(
         self,
@@ -1142,7 +1142,7 @@ pub trait StreamExt: Stream {
     /// fut.await;
     /// # })
     /// ```
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn for_each_concurrent<Fut, F>(
         self,
@@ -1365,7 +1365,7 @@ pub trait StreamExt: Stream {
     ///
     /// This method is only available when the `std` or `alloc` feature of this
     /// library is activated, and it is activated by default.
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn buffered(self, n: usize) -> Buffered<Self>
     where
@@ -1410,7 +1410,7 @@ pub trait StreamExt: Stream {
     /// assert_eq!(buffered.next().await, None);
     /// # Ok::<(), i32>(()) }).unwrap();
     /// ```
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn buffer_unordered(self, n: usize) -> BufferUnordered<Self>
     where
@@ -1577,7 +1577,7 @@ pub trait StreamExt: Stream {
     /// library is activated, and it is activated by default.
     #[cfg(feature = "sink")]
     #[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>)
     where
diff --git a/futures-util/src/stream/try_stream/mod.rs b/futures-util/src/stream/try_stream/mod.rs
index 5d5702f36..7b55444b3 100644
--- a/futures-util/src/stream/try_stream/mod.rs
+++ b/futures-util/src/stream/try_stream/mod.rs
@@ -89,10 +89,10 @@ mod try_flatten;
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::try_flatten::TryFlatten;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod try_flatten_unordered;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::try_flatten_unordered::TryFlattenUnordered;
@@ -133,26 +133,26 @@ mod try_take_while;
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::try_take_while::TryTakeWhile;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod try_buffer_unordered;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::try_buffer_unordered::TryBufferUnordered;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod try_buffered;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::try_buffered::TryBuffered;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 mod try_for_each_concurrent;
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
 pub use self::try_for_each_concurrent::TryForEachConcurrent;
@@ -551,7 +551,7 @@ pub trait TryStreamExt: TryStream {
     /// assert_eq!(Err(oneshot::Canceled), fut.await);
     /// # })
     /// ```
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn try_for_each_concurrent<Fut, F>(
         self,
@@ -827,7 +827,7 @@ pub trait TryStreamExt: TryStream {
     /// assert_eq!(values, vec![Ok(1), Ok(2), Ok(4), Err(3), Err(5)]);
     /// # });
     /// ```
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn try_flatten_unordered(self, limit: impl Into<Option<usize>>) -> TryFlattenUnordered<Self>
     where
@@ -1029,7 +1029,7 @@ pub trait TryStreamExt: TryStream {
     /// assert_eq!(buffered.next().await, Some(Err("error in the stream")));
     /// # Ok::<(), Box<dyn std::error::Error>>(()) }).unwrap();
     /// ```
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn try_buffer_unordered(self, n: usize) -> TryBufferUnordered<Self>
     where
@@ -1105,7 +1105,7 @@ pub trait TryStreamExt: TryStream {
     /// assert_eq!(buffered.next().await, Some(Err("error in the stream")));
     /// # Ok::<(), Box<dyn std::error::Error>>(()) }).unwrap();
     /// ```
-    #[cfg(not(futures_no_atomic_cas))]
+    #[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
     #[cfg(feature = "alloc")]
     fn try_buffered(self, n: usize) -> TryBuffered<Self>
     where
diff --git a/futures-util/src/task/mod.rs b/futures-util/src/task/mod.rs
index 3ed4bfada..7a9e993e5 100644
--- a/futures-util/src/task/mod.rs
+++ b/futures-util/src/task/mod.rs
@@ -18,19 +18,22 @@ pub use futures_task::{FutureObj, LocalFutureObj, LocalSpawn, Spawn, SpawnError,
 pub use futures_task::noop_waker;
 pub use futures_task::noop_waker_ref;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use futures_task::ArcWake;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use futures_task::waker;
 
-#[cfg(not(futures_no_atomic_cas))]
+#[cfg_attr(target_os = "none", cfg(target_has_atomic = "ptr"))]
 #[cfg(feature = "alloc")]
 pub use futures_task::{waker_ref, WakerRef};
 
-#[cfg(any(not(futures_no_atomic_cas), feature = "portable-atomic"))]
+#[cfg_attr(
+    target_os = "none",
+    cfg(any(target_has_atomic = "ptr", feature = "portable-atomic"))
+)]
 pub use futures_core::task::__internal::AtomicWaker;
 
 mod spawn;
diff --git a/no_atomic_cas.rs b/no_atomic_cas.rs
deleted file mode 100644
index 16ec628cd..000000000
--- a/no_atomic_cas.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-// This file is @generated by no_atomic_cas.sh.
-// It is not intended for manual editing.
-
-const NO_ATOMIC_CAS: &[&str] = &[
-    "armv4t-none-eabi",
-    "armv5te-none-eabi",
-    "avr-unknown-gnu-atmega328",
-    "bpfeb-unknown-none",
-    "bpfel-unknown-none",
-    "msp430-none-elf",
-    "riscv32i-unknown-none-elf",
-    "riscv32im-unknown-none-elf",
-    "riscv32imc-unknown-none-elf",
-    "thumbv4t-none-eabi",
-    "thumbv5te-none-eabi",
-    "thumbv6m-none-eabi",
-];