Auto merge of #121269 - calebzulawski:sync-portable-simd-2024-02-18, r=Mark-Simulacrum

Portable SIMD subtree update

Syncs nightly to the latest changes from rust-lang/portable-simd

r? `@rust-lang/libs`

Also, fixes #119904 which is now fixed upstream.

Author: bors

Diff for: library/portable-simd/crates/core_simd/src/intrinsics.rs

@@ -1,20 +1,38 @@
 #![no_std]
 #![feature(
+    const_intrinsic_copy,
     const_refs_to_cell,
     const_maybe_uninit_as_mut_ptr,
     const_mut_refs,
     convert_float_to_int,
+    core_intrinsics,
     decl_macro,
     inline_const,
     intra_doc_pointers,
-    platform_intrinsics,
     repr_simd,
     simd_ffi,
     staged_api,
-    stdsimd,
     strict_provenance,
     ptr_metadata
 )]
+#![cfg_attr(
+    all(
+        any(target_arch = "aarch64", target_arch = "arm",),
+        any(
+            all(target_feature = "v6", not(target_feature = "mclass")),
+            all(target_feature = "mclass", target_feature = "dsp"),
+        )
+    ),
+    feature(stdarch_arm_dsp)
+)]
+#![cfg_attr(
+    all(target_arch = "arm", target_feature = "v7"),
+    feature(stdarch_arm_neon_intrinsics)
+)]
+#![cfg_attr(
+    any(target_arch = "powerpc", target_arch = "powerpc64"),
+    feature(stdarch_powerpc)
+)]
 #![warn(missing_docs, clippy::missing_inline_in_public_items)] // basically all items, really
 #![deny(unsafe_op_in_unsafe_fn, clippy::undocumented_unsafe_blocks)]
 #![allow(internal_features)]

Diff for: library/portable-simd/crates/core_simd/src/lib.rs

@@ -12,9 +12,7 @@
 )]
 mod mask_impl;
 
-use crate::simd::{
-    cmp::SimdPartialEq, intrinsics, LaneCount, Simd, SimdCast, SimdElement, SupportedLaneCount,
-};
+use crate::simd::{LaneCount, Simd, SimdCast, SimdElement, SupportedLaneCount};
 use core::cmp::Ordering;
 use core::{fmt, mem};
 
@@ -35,7 +33,7 @@ mod sealed {
 
         fn eq(self, other: Self) -> bool;
 
-        fn as_usize(self) -> usize;
+        fn to_usize(self) -> usize;
 
         type Unsigned: SimdElement;
 
@@ -60,14 +58,23 @@ macro_rules! impl_element {
             where
                 LaneCount<N>: SupportedLaneCount,
             {
-                (value.simd_eq(Simd::splat(0 as _)) | value.simd_eq(Simd::splat(-1 as _))).all()
+                // We can't use `Simd` directly, because `Simd`'s functions call this function and
+                // we will end up with an infinite loop.
+                // Safety: `value` is an integer vector
+                unsafe {
+                    use core::intrinsics::simd;
+                    let falses: Simd<Self, N> = simd::simd_eq(value, Simd::splat(0 as _));
+                    let trues: Simd<Self, N> = simd::simd_eq(value, Simd::splat(-1 as _));
+                    let valid: Simd<Self, N> = simd::simd_or(falses, trues);
+                    simd::simd_reduce_all(valid)
+                }
             }
 
             #[inline]
             fn eq(self, other: Self) -> bool { self == other }
 
             #[inline]
-            fn as_usize(self) -> usize {
+            fn to_usize(self) -> usize {
                 self as usize
             }
 
@@ -141,8 +148,9 @@ where
         // but these are "dependently-sized" types, so copy elision it is!
         unsafe {
             let bytes: [u8; N] = mem::transmute_copy(&array);
-            let bools: Simd<i8, N> = intrinsics::simd_ne(Simd::from_array(bytes), Simd::splat(0u8));
-            Mask::from_int_unchecked(intrinsics::simd_cast(bools))
+            let bools: Simd<i8, N> =
+                core::intrinsics::simd::simd_ne(Simd::from_array(bytes), Simd::splat(0u8));
+            Mask::from_int_unchecked(core::intrinsics::simd::simd_cast(bools))
         }
     }
 
@@ -160,7 +168,7 @@ where
         // This would be hypothetically valid as an "in-place" transmute,
         // but these are "dependently-sized" types, so copy elision it is!
         unsafe {
-            let mut bytes: Simd<i8, N> = intrinsics::simd_cast(self.to_int());
+            let mut bytes: Simd<i8, N> = core::intrinsics::simd::simd_cast(self.to_int());
             bytes &= Simd::splat(1i8);
             mem::transmute_copy(&bytes)
         }
@@ -175,7 +183,10 @@ where
     #[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 {
         // Safety: the caller must confirm this invariant
-        unsafe { Self(mask_impl::Mask::from_int_unchecked(value)) }
+        unsafe {
+            core::intrinsics::assume(<T as Sealed>::valid(value));
+            Self(mask_impl::Mask::from_int_unchecked(value))
+        }
     }
 
     /// Converts a vector of integers to a mask, where 0 represents `false` and -1
@@ -374,23 +385,25 @@ where
         );
 
         // Safety: the input and output are integer vectors
-        let index: Simd<T, N> = unsafe { intrinsics::simd_cast(index) };
+        let index: Simd<T, N> = unsafe { core::intrinsics::simd::simd_cast(index) };
 
         let masked_index = self.select(index, Self::splat(true).to_int());
 
         // Safety: the input and output are integer vectors
-        let masked_index: Simd<T::Unsigned, N> = unsafe { intrinsics::simd_cast(masked_index) };
+        let masked_index: Simd<T::Unsigned, N> =
+            unsafe { core::intrinsics::simd::simd_cast(masked_index) };
 
         // Safety: the input is an integer vector
-        let min_index: T::Unsigned = unsafe { intrinsics::simd_reduce_min(masked_index) };
+        let min_index: T::Unsigned =
+            unsafe { core::intrinsics::simd::simd_reduce_min(masked_index) };
 
         // Safety: the return value is the unsigned version of T
         let min_index: T = unsafe { core::mem::transmute_copy(&min_index) };
 
         if min_index.eq(T::TRUE) {
             None
         } else {
-            Some(min_index.as_usize())
+            Some(min_index.to_usize())
         }
     }
 }

Diff for: library/portable-simd/crates/core_simd/src/masks.rs

@@ -1,6 +1,5 @@
 #![allow(unused_imports)]
 use super::MaskElement;
-use crate::simd::intrinsics;
 use crate::simd::{LaneCount, Simd, SupportedLaneCount};
 use core::marker::PhantomData;
 
@@ -109,14 +108,18 @@ where
     #[must_use = "method returns a new vector and does not mutate the original value"]
     pub fn to_int(self) -> Simd<T, N> {
         unsafe {
-            intrinsics::simd_select_bitmask(self.0, Simd::splat(T::TRUE), Simd::splat(T::FALSE))
+            core::intrinsics::simd::simd_select_bitmask(
+                self.0,
+                Simd::splat(T::TRUE),
+                Simd::splat(T::FALSE),
+            )
         }
     }
 
     #[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 {
-        unsafe { Self(intrinsics::simd_bitmask(value), PhantomData) }
+        unsafe { Self(core::intrinsics::simd::simd_bitmask(value), PhantomData) }
     }
 
     #[inline]