Rollup merge of #155930 - folkertdev:sync-from-portable-simd-2026-04-28, r=folkertdev

Sync from portable simd 2026 04 28

r? calebzulawski (I'll self-approve if CI looks good)

Author: JonathanBrouwer

library/portable-simd/crates/core_simd/src/masks.rs

@@ -400,7 +400,15 @@ where
         if min_index.eq(T::TRUE) {
             None
         } else {
-            Some(min_index.to_usize())
+            let min_index = min_index.to_usize();
+
+            // Allow eliminating bounds checks when using the index
+            // Safety: the index can't exceed the number of elements in the vector
+            unsafe {
+                core::hint::assert_unchecked(min_index < N);
+            }
+
+            Some(min_index)
         }
     }
 }

library/portable-simd/crates/core_simd/src/simd/num/float.rs

@@ -430,14 +430,14 @@ macro_rules! impl_trait {
 
             #[inline]
             fn reduce_max(self) -> Self::Scalar {
-                // Safety: `self` is a float vector
-                unsafe { core::intrinsics::simd::simd_reduce_max(self) }
+                // LLVM has no intrinsic we can use here
+                // (https://github.com/llvm/llvm-project/issues/185827).
+                self.as_array().iter().copied().fold(Self::Scalar::NAN, Self::Scalar::max)
             }
 
             #[inline]
             fn reduce_min(self) -> Self::Scalar {
-                // Safety: `self` is a float vector
-                unsafe { core::intrinsics::simd::simd_reduce_min(self) }
+                self.as_array().iter().copied().fold(Self::Scalar::NAN, Self::Scalar::min)
             }
         }
         )*

library/portable-simd/crates/core_simd/src/simd/prelude.rs

@@ -14,6 +14,10 @@ pub use super::{
     simd_swizzle,
 };
 
+#[rustfmt::skip]
+#[doc(no_inline)]
+pub use super::{f16x1, f16x2, f16x4, f16x8, f16x16, f16x32, f16x64};
+
 #[rustfmt::skip]
 #[doc(no_inline)]
 pub use super::{f32x1, f32x2, f32x4, f32x8, f32x16, f32x32, f32x64};

library/portable-simd/crates/std_float/tests/float.rs

@@ -33,23 +33,6 @@ macro_rules! unary_approx_test {
     }
 }
 
-macro_rules! binary_approx_test {
-    { $scalar:tt, $($func:tt),+ } => {
-        test_helpers::test_lanes! {
-            $(
-            fn $func<const LANES: usize>() {
-                test_helpers::test_binary_elementwise_approx(
-                    &core_simd::simd::Simd::<$scalar, LANES>::$func,
-                    &$scalar::$func,
-                    &|_, _| true,
-                    16,
-                )
-            }
-            )*
-        }
-    }
-}
-
 macro_rules! ternary_test {
     { $scalar:tt, $($func:tt),+ } => {
         test_helpers::test_lanes! {
@@ -76,7 +59,19 @@ macro_rules! impl_tests {
 
             // https://github.com/rust-lang/miri/issues/3555
             unary_approx_test! { $scalar, sin, cos, exp, exp2, ln, log2, log10 }
-            binary_approx_test! { $scalar, log }
+
+            // The implementation of log is a.ln() / b.ln(), so there are 2 inexact operations,
+            // hence a larger ulps is needed.
+            test_helpers::test_lanes! {
+                fn log<const LANES: usize>() {
+                    test_helpers::test_binary_elementwise_approx(
+                        &core_simd::simd::Simd::<$scalar, LANES>::log,
+                        &$scalar::log,
+                        &|_, _| true,
+                        32,
+                    )
+                }
+            }
 
             test_helpers::test_lanes! {
                 fn fract<const LANES: usize>() {

library/portable-simd/crates/test_helpers/src/lib.rs

@@ -122,24 +122,35 @@ pub fn make_runner() -> proptest::test_runner::TestRunner {
     proptest::test_runner::TestRunner::new(proptest::test_runner::Config::with_cases(4))
 }
 
+#[track_caller]
+fn unwrap_test_error<T, U: std::fmt::Debug>(
+    x: Result<T, proptest::test_runner::TestError<U>>,
+) -> T {
+    // Using the `Display` instance of the error is much more readable.
+    match x {
+        Ok(v) => v,
+        Err(e) => panic!("{e}"),
+    }
+}
+
 /// Test a function that takes a single value.
 pub fn test_1<A: core::fmt::Debug + DefaultStrategy>(
     f: &dyn Fn(A) -> proptest::test_runner::TestCaseResult,
 ) {
     let mut runner = make_runner();
-    runner.run(&A::default_strategy(), f).unwrap();
+    unwrap_test_error(runner.run(&A::default_strategy(), f))
 }
 
 /// Test a function that takes two values.
 pub fn test_2<A: core::fmt::Debug + DefaultStrategy, B: core::fmt::Debug + DefaultStrategy>(
     f: &dyn Fn(A, B) -> proptest::test_runner::TestCaseResult,
 ) {
     let mut runner = make_runner();
-    runner
-        .run(&(A::default_strategy(), B::default_strategy()), |(a, b)| {
+    unwrap_test_error(
+        runner.run(&(A::default_strategy(), B::default_strategy()), |(a, b)| {
             f(a, b)
-        })
-        .unwrap();
+        }),
+    )
 }
 
 /// Test a function that takes two values.
@@ -151,16 +162,14 @@ pub fn test_3<
     f: &dyn Fn(A, B, C) -> proptest::test_runner::TestCaseResult,
 ) {
     let mut runner = make_runner();
-    runner
-        .run(
-            &(
-                A::default_strategy(),
-                B::default_strategy(),
-                C::default_strategy(),
-            ),
-            |(a, b, c)| f(a, b, c),
-        )
-        .unwrap();
+    unwrap_test_error(runner.run(
+        &(
+            A::default_strategy(),
+            B::default_strategy(),
+            C::default_strategy(),
+        ),
+        |(a, b, c)| f(a, b, c),
+    ));
 }
 
 /// Test a unary vector function against a unary scalar function, applied elementwise.

library/portable-simd/rust-toolchain.toml

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2026-03-18"
+channel = "nightly-2026-04-28"
 components = ["rustfmt", "clippy", "miri", "rust-src"]