Stabilize funnel_shifts (including const)

`funnel_shl` and `funnel_shr` have been around for close to a year, the
unchecked versions for a number of months. These are reasonably small
and uncontroversial, and it can be tricky to get similar performance
with a fallback; stabilize them here.

Newly stable API:

    impl {u8, u16, u32, u64, u128, usize} {
        pub const fn funnel_shl(self, right: Self, shift: u32) -> Self;
        pub const fn funnel_shr(self, right: Self, shift: u32) -> Self;

        pub const unsafe fn unchecked_funnel_shl(self, right: Self, shift: u32) -> Self;
        pub const unsafe fn unchecked_funnel_shr(self, right: Self, shift: u32) -> Self;
    }

The tracking issue also mentions a `wrapping_` version but it has not
been implemented.

Tracking issue: RUST-145686

Author: tgross35

library/core/src/intrinsics/mod.rs

@@ -2206,7 +2206,7 @@ pub const unsafe fn unchecked_mul<T: Copy>(x: T, y: T) -> T;
 #[rustc_intrinsic_const_stable_indirect]
 #[rustc_nounwind]
 #[rustc_intrinsic]
-#[rustc_allow_const_fn_unstable(const_trait_impl, funnel_shifts)]
+#[rustc_allow_const_fn_unstable(const_trait_impl)]
 #[miri::intrinsic_fallback_is_spec]
 pub const fn rotate_left<T: [const] fallback::FunnelShift>(x: T, shift: u32) -> T {
     // Make sure to call the intrinsic for `funnel_shl`, not the fallback impl.
@@ -2228,7 +2228,7 @@ pub const fn rotate_left<T: [const] fallback::FunnelShift>(x: T, shift: u32) ->
 #[rustc_intrinsic_const_stable_indirect]
 #[rustc_nounwind]
 #[rustc_intrinsic]
-#[rustc_allow_const_fn_unstable(const_trait_impl, funnel_shifts)]
+#[rustc_allow_const_fn_unstable(const_trait_impl)]
 #[miri::intrinsic_fallback_is_spec]
 pub const fn rotate_right<T: [const] fallback::FunnelShift>(x: T, shift: u32) -> T {
     // Make sure to call the intrinsic for `funnel_shr`, not the fallback impl.
@@ -2324,11 +2324,11 @@ pub const fn saturating_sub<T: Copy>(a: T, b: T) -> T;
 ///
 /// Safe versions of this intrinsic are available on the integer primitives
 /// via the `funnel_shl` method. For example, [`u32::funnel_shl`].
+#[rustc_intrinsic_const_stable_indirect]
 #[rustc_intrinsic]
 #[rustc_nounwind]
-#[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")]
-#[unstable(feature = "funnel_shifts", issue = "145686")]
 #[track_caller]
+#[rustc_allow_const_fn_unstable(const_trait_impl, core_intrinsics_fallbacks)]
 #[miri::intrinsic_fallback_is_spec]
 pub const unsafe fn unchecked_funnel_shl<T: [const] fallback::FunnelShift>(
     a: T,
@@ -2352,11 +2352,11 @@ pub const unsafe fn unchecked_funnel_shl<T: [const] fallback::FunnelShift>(
 ///
 /// Safer versions of this intrinsic are available on the integer primitives
 /// via the `funnel_shr` method. For example, [`u32::funnel_shr`]
+#[rustc_intrinsic_const_stable_indirect]
 #[rustc_intrinsic]
 #[rustc_nounwind]
-#[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")]
-#[unstable(feature = "funnel_shifts", issue = "145686")]
 #[track_caller]
+#[rustc_allow_const_fn_unstable(const_trait_impl, core_intrinsics_fallbacks)]
 #[miri::intrinsic_fallback_is_spec]
 pub const unsafe fn unchecked_funnel_shr<T: [const] fallback::FunnelShift>(
     a: T,

library/core/src/lib.rs

@@ -131,7 +131,6 @@
 #![feature(final_associated_functions)]
 #![feature(freeze_impls)]
 #![feature(fundamental)]
-#![feature(funnel_shifts)]
 #![feature(impl_restriction)]
 #![feature(intra_doc_pointers)]
 #![feature(intrinsics)]

library/core/src/num/uint_macros.rs

@@ -521,8 +521,6 @@ macro_rules! uint_impl {
         /// # Examples
         ///
         /// ```
-        /// #![feature(funnel_shifts)]
-        ///
         #[doc = concat!("let a = ", $rot_op, "_", stringify!($SelfT), ";")]
         #[doc = concat!("let b = ", $fsh_op, "_", stringify!($SelfT), ";")]
         ///
@@ -542,16 +540,14 @@ macro_rules! uint_impl {
         /// rotating by an unbounded amount like [`rotate_left`](Self::rotate_left) does:
         ///
         /// ```should_panic
-        /// #![feature(funnel_shifts)]
-        ///
         #[doc = concat!("let a = ", stringify!($SelfT), "::MAX;")]
         /// // Okay
         #[doc = concat!("let _ = a.rotate_left(", stringify!($SelfT), "::BITS);")]
         /// // Panics
         #[doc = concat!("let _ = a.funnel_shl(a, ", stringify!($SelfT), "::BITS);")]
         /// ```
-        #[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")]
-        #[unstable(feature = "funnel_shifts", issue = "145686")]
+        #[rustc_const_stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
+        #[stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
         #[must_use = "this returns the result of the operation, without modifying the original"]
         #[inline(always)]
         pub const fn funnel_shl(self, right: Self, n: u32) -> Self {
@@ -577,8 +573,6 @@ macro_rules! uint_impl {
         /// # Examples
         ///
         /// ```
-        /// #![feature(funnel_shifts)]
-        ///
         #[doc = concat!("let a = ", $rot_op, "_", stringify!($SelfT), ";")]
         #[doc = concat!("let b = ", $fsh_op, "_", stringify!($SelfT), ";")]
         ///
@@ -598,16 +592,14 @@ macro_rules! uint_impl {
         /// rotating by an unbounded amount like [`rotate_right`](Self::rotate_right) does:
         ///
         /// ```should_panic
-        /// #![feature(funnel_shifts)]
-        ///
         #[doc = concat!("let a = ", stringify!($SelfT), "::MAX;")]
         /// // Okay
         #[doc = concat!("let _ = a.rotate_right(", stringify!($SelfT), "::BITS);")]
         /// // Panics
         #[doc = concat!("let _ = a.funnel_shr(a, ", stringify!($SelfT), "::BITS);")]
         /// ```
-        #[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")]
-        #[unstable(feature = "funnel_shifts", issue = "145686")]
+        #[rustc_const_stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
+        #[stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
         #[must_use = "this returns the result of the operation, without modifying the original"]
         #[inline(always)]
         pub const fn funnel_shr(self, right: Self, n: u32) -> Self {
@@ -624,8 +616,8 @@ macro_rules! uint_impl {
         #[doc = concat!("`", stringify!($SelfT) , "::BITS`,")]
         /// i.e. when [`funnel_shl`](Self::funnel_shl) would panic.
         ///
-        #[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")]
-        #[unstable(feature = "funnel_shifts", issue = "145686")]
+        #[rustc_const_stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
+        #[stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
         #[must_use = "this returns the result of the operation, without modifying the original"]
         #[inline(always)]
         #[track_caller]
@@ -650,8 +642,8 @@ macro_rules! uint_impl {
         #[doc = concat!("`", stringify!($SelfT) , "::BITS`,")]
         /// i.e. when [`funnel_shr`](Self::funnel_shr) would panic.
         ///
-        #[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")]
-        #[unstable(feature = "funnel_shifts", issue = "145686")]
+        #[rustc_const_stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
+        #[stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
         #[must_use = "this returns the result of the operation, without modifying the original"]
         #[inline(always)]
         #[track_caller]

library/coretests/tests/lib.rs

@@ -60,7 +60,6 @@
 #![feature(fmt_internals)]
 #![feature(formatting_options)]
 #![feature(freeze)]
-#![feature(funnel_shifts)]
 #![feature(future_join)]
 #![feature(generic_assert_internals)]
 #![feature(hasher_prefixfree_extras)]

library/std/src/lib.rs

@@ -350,7 +350,6 @@
 #![feature(fmt_internals)]
 #![feature(fn_ptr_trait)]
 #![feature(formatting_options)]
-#![feature(funnel_shifts)]
 #![feature(generic_atomic)]
 #![feature(hash_map_internals)]
 #![feature(hash_map_macro)]

library/stdarch/crates/core_arch/src/lib.rs

@@ -33,7 +33,6 @@
     x86_amx_intrinsics,
     f16,
     aarch64_unstable_target_feature,
-    funnel_shifts,
     avx10_target_feature,
     const_trait_impl,
     const_cmp,

src/tools/miri/tests/fail/intrinsics/funnel_shl.rs

@@ -1,4 +1,4 @@
-#![feature(core_intrinsics, funnel_shifts)]
+#![feature(core_intrinsics)]
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/funnel_shr.rs

@@ -1,4 +1,4 @@
-#![feature(core_intrinsics, funnel_shifts)]
+#![feature(core_intrinsics)]
 
 fn main() {
     unsafe {

src/tools/miri/tests/pass/intrinsics/integer.rs

@@ -1,5 +1,5 @@
 //@run-native
-#![feature(core_intrinsics, funnel_shifts)]
+#![feature(core_intrinsics)]
 use std::intrinsics::*;
 
 fn main() {

tests/codegen-llvm/force-intrinsic-fallback.rs

@@ -2,7 +2,7 @@
 //
 //@ revisions: NORMAL FALLBACK
 //@ [FALLBACK] compile-flags: -Zforce-intrinsic-fallback
-#![feature(core_intrinsics, funnel_shifts)]
+#![feature(core_intrinsics)]
 
 // Check the effect of `-Zforce-intrinsic-fallback`.
 //