https://github.com/rust-lang/rust/issues/138054
https://bugs.gentoo.org/953109#c7
diff --git a/library/portable-simd/crates/core_simd/src/lib.rs b/library/portable-simd/crates/core_simd/src/lib.rs
index 7f57847c9c234..717b882b64ba1 100644
--- a/library/portable-simd/crates/core_simd/src/lib.rs
+++ b/library/portable-simd/crates/core_simd/src/lib.rs
@@ -35,7 +35,11 @@
     feature(stdarch_x86_avx512)
 )]
 #![warn(missing_docs, clippy::missing_inline_in_public_items)] // basically all items, really
-#![deny(unsafe_op_in_unsafe_fn, clippy::undocumented_unsafe_blocks)]
+#![deny(
+    unsafe_op_in_unsafe_fn,
+    unreachable_pub,
+    clippy::undocumented_unsafe_blocks
+)]
 #![doc(test(attr(deny(warnings))))]
 #![allow(internal_features)]
 #![unstable(feature = "portable_simd", issue = "86656")]
diff --git a/library/portable-simd/crates/core_simd/src/masks/bitmask.rs b/library/portable-simd/crates/core_simd/src/masks/bitmask.rs
index db4312d5bf88a..8221d8f17e90e 100644
--- a/library/portable-simd/crates/core_simd/src/masks/bitmask.rs
+++ b/library/portable-simd/crates/core_simd/src/masks/bitmask.rs
@@ -5,7 +5,7 @@ use core::marker::PhantomData;
 
 /// A mask where each lane is represented by a single bit.
 #[repr(transparent)]
-pub struct Mask<T, const N: usize>(
+pub(crate) struct Mask<T, const N: usize>(
     <LaneCount<N> as SupportedLaneCount>::BitMask,
     PhantomData<T>,
 )
@@ -78,7 +78,7 @@ where
 {
     #[inline]
     #[must_use = "method returns a new mask and does not mutate the original value"]
-    pub fn splat(value: bool) -> Self {
+    pub(crate) fn splat(value: bool) -> Self {
         let mut mask = <LaneCount<N> as SupportedLaneCount>::BitMask::default();
         if value {
             mask.as_mut().fill(u8::MAX)
@@ -93,12 +93,12 @@ where
 
     #[inline]
     #[must_use = "method returns a new bool and does not mutate the original value"]
-    pub unsafe fn test_unchecked(&self, lane: usize) -> bool {
+    pub(crate) unsafe fn test_unchecked(&self, lane: usize) -> bool {
         (self.0.as_ref()[lane / 8] >> (lane % 8)) & 0x1 > 0
     }
 
     #[inline]
-    pub unsafe fn set_unchecked(&mut self, lane: usize, value: bool) {
+    pub(crate) unsafe fn set_unchecked(&mut self, lane: usize, value: bool) {
         unsafe {
             self.0.as_mut()[lane / 8] ^= ((value ^ self.test_unchecked(lane)) as u8) << (lane % 8)
         }
@@ -106,7 +106,7 @@ where
 
     #[inline]
     #[must_use = "method returns a new vector and does not mutate the original value"]
-    pub fn to_int(self) -> Simd<T, N> {
+    pub(crate) fn to_int(self) -> Simd<T, N> {
         unsafe {
             core::intrinsics::simd::simd_select_bitmask(
                 self.0,
@@ -118,19 +118,19 @@ where
 
     #[inline]
     #[must_use = "method returns a new mask and does not mutate the original value"]
-    pub unsafe fn from_int_unchecked(value: Simd<T, N>) -> Self {
+    pub(crate) unsafe fn from_int_unchecked(value: Simd<T, N>) -> Self {
         unsafe { Self(core::intrinsics::simd::simd_bitmask(value), PhantomData) }
     }
 
     #[inline]
-    pub fn to_bitmask_integer(self) -> u64 {
+    pub(crate) fn to_bitmask_integer(self) -> u64 {
         let mut bitmask = [0u8; 8];
         bitmask[..self.0.as_ref().len()].copy_from_slice(self.0.as_ref());
         u64::from_ne_bytes(bitmask)
     }
 
     #[inline]
-    pub fn from_bitmask_integer(bitmask: u64) -> Self {
+    pub(crate) fn from_bitmask_integer(bitmask: u64) -> Self {
         let mut bytes = <LaneCount<N> as SupportedLaneCount>::BitMask::default();
         let len = bytes.as_mut().len();
         bytes
@@ -141,7 +141,7 @@ where
 
     #[inline]
     #[must_use = "method returns a new mask and does not mutate the original value"]
-    pub fn convert<U>(self) -> Mask<U, N>
+    pub(crate) fn convert<U>(self) -> Mask<U, N>
     where
         U: MaskElement,
     {
@@ -151,13 +151,13 @@ where
 
     #[inline]
     #[must_use = "method returns a new bool and does not mutate the original value"]
-    pub fn any(self) -> bool {
+    pub(crate) fn any(self) -> bool {
         self != Self::splat(false)
     }
 
     #[inline]
     #[must_use = "method returns a new bool and does not mutate the original value"]
-    pub fn all(self) -> bool {
+    pub(crate) fn all(self) -> bool {
         self == Self::splat(true)
     }
 }
diff --git a/library/portable-simd/crates/core_simd/src/masks/full_masks.rs b/library/portable-simd/crates/core_simd/src/masks/full_masks.rs
index ae55cf1f8fa87..a693ea90b9cb8 100644
--- a/library/portable-simd/crates/core_simd/src/masks/full_masks.rs
+++ b/library/portable-simd/crates/core_simd/src/masks/full_masks.rs
@@ -3,7 +3,7 @@
 use crate::simd::{LaneCount, MaskElement, Simd, SupportedLaneCount};
 
 #[repr(transparent)]
-pub struct Mask<T, const N: usize>(Simd<T, N>)
+pub(crate) struct Mask<T, const N: usize>(Simd<T, N>)
 where
     T: MaskElement,
     LaneCount<N>: SupportedLaneCount;
@@ -103,36 +103,36 @@ where
 {
     #[inline]
     #[must_use = "method returns a new mask and does not mutate the original value"]
-    pub fn splat(value: bool) -> Self {
+    pub(crate) fn splat(value: bool) -> Self {
         Self(Simd::splat(if value { T::TRUE } else { T::FALSE }))
     }
 
     #[inline]
     #[must_use = "method returns a new bool and does not mutate the original value"]
-    pub unsafe fn test_unchecked(&self, lane: usize) -> bool {
+    pub(crate) unsafe fn test_unchecked(&self, lane: usize) -> bool {
         T::eq(self.0[lane], T::TRUE)
     }
 
     #[inline]
-    pub unsafe fn set_unchecked(&mut self, lane: usize, value: bool) {
+    pub(crate) unsafe fn set_unchecked(&mut self, lane: usize, value: bool) {
         self.0[lane] = if value { T::TRUE } else { T::FALSE }
     }
 
     #[inline]
     #[must_use = "method returns a new vector and does not mutate the original value"]
-    pub fn to_int(self) -> Simd<T, N> {
+    pub(crate) fn to_int(self) -> Simd<T, N> {
         self.0
     }
 
     #[inline]
     #[must_use = "method returns a new mask and does not mutate the original value"]
-    pub unsafe fn from_int_unchecked(value: Simd<T, N>) -> Self {
+    pub(crate) unsafe fn from_int_unchecked(value: Simd<T, N>) -> Self {
         Self(value)
     }
 
     #[inline]
     #[must_use = "method returns a new mask and does not mutate the original value"]
-    pub fn convert<U>(self) -> Mask<U, N>
+    pub(crate) fn convert<U>(self) -> Mask<U, N>
     where
         U: MaskElement,
     {
@@ -221,14 +221,14 @@ where
 
     #[inline]
     #[must_use = "method returns a new bool and does not mutate the original value"]
-    pub fn any(self) -> bool {
+    pub(crate) fn any(self) -> bool {
         // Safety: use `self` as an integer vector
         unsafe { core::intrinsics::simd::simd_reduce_any(self.to_int()) }
     }
 
     #[inline]
     #[must_use = "method returns a new bool and does not mutate the original value"]
-    pub fn all(self) -> bool {
+    pub(crate) fn all(self) -> bool {
         // Safety: use `self` as an integer vector
         unsafe { core::intrinsics::simd::simd_reduce_all(self.to_int()) }
     }