1 files changed, 106 insertions, 0 deletions
diff --git a/library/portable-simd/crates/test_helpers/src/biteq.rs b/library/portable-simd/crates/test_helpers/src/biteq.rs
new file mode 100644
index 000000000..00350e224
--- /dev/null
+++ b/library/portable-simd/crates/test_helpers/src/biteq.rs
@@ -0,0 +1,106 @@
+//! Compare numeric types by exact bit value.
+
+pub trait BitEq {
+    fn biteq(&self, other: &Self) -> bool;
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result;
+}
+
+impl BitEq for bool {
+    fn biteq(&self, other: &Self) -> bool {
+        self == other
+    }
+
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+macro_rules! impl_integer_biteq {
+    { $($type:ty),* } => {
+        $(
+        impl BitEq for $type {
+            fn biteq(&self, other: &Self) -> bool {
+                self == other
+            }
+
+            fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+                write!(f, "{:?} ({:x})", self, self)
+            }
+        }
+        )*
+    };
+}
+
+impl_integer_biteq! { u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize }
+
+macro_rules! impl_float_biteq {
+    { $($type:ty),* } => {
+        $(
+        impl BitEq for $type {
+            fn biteq(&self, other: &Self) -> bool {
+                if self.is_nan() && other.is_nan() {
+                    true // exact nan bits don't matter
+                } else {
+                    self.to_bits() == other.to_bits()
+                }
+            }
+
+            fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+                write!(f, "{:?} ({:x})", self, self.to_bits())
+            }
+        }
+        )*
+    };
+}
+
+impl_float_biteq! { f32, f64 }
+
+impl<T: BitEq, const N: usize> BitEq for [T; N] {
+    fn biteq(&self, other: &Self) -> bool {
+        self.iter()
+            .zip(other.iter())
+            .fold(true, |value, (left, right)| value && left.biteq(right))
+    }
+
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        #[repr(transparent)]
+        struct Wrapper<'a, T: BitEq>(&'a T);
+
+        impl<T: BitEq> core::fmt::Debug for Wrapper<'_, T> {
+            fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+                self.0.fmt(f)
+            }
+        }
+
+        f.debug_list()
+            .entries(self.iter().map(|x| Wrapper(x)))
+            .finish()
+    }
+}
+
+#[doc(hidden)]
+pub struct BitEqWrapper<'a, T>(pub &'a T);
+
+impl<T: BitEq> PartialEq for BitEqWrapper<'_, T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0.biteq(other.0)
+    }
+}
+
+impl<T: BitEq> core::fmt::Debug for BitEqWrapper<'_, T> {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+#[macro_export]
+macro_rules! prop_assert_biteq {
+    { $a:expr, $b:expr $(,)? } => {
+        {
+            use $crate::biteq::BitEqWrapper;
+            let a = $a;
+            let b = $b;
+            proptest::prop_assert_eq!(BitEqWrapper(&a), BitEqWrapper(&b));
+        }
+    }
+}