1 files changed, 28 insertions, 0 deletions
diff --git a/library/compiler-builtins/libm/src/math/generic/fmaximum.rs b/library/compiler-builtins/libm/src/math/generic/fmaximum.rs
new file mode 100644
index 00000000000..387055af29c
--- /dev/null
+++ b/library/compiler-builtins/libm/src/math/generic/fmaximum.rs
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: MIT OR Apache-2.0 */
+//! IEEE 754-2019 `maximum`.
+//!
+//! Per the spec, returns the canonicalized result of:
+//! - `x` if `x > y`
+//! - `y` if `y > x`
+//! - qNaN if either operation is NaN
+//! - Logic following +0.0 > -0.0
+//!
+//! Excluded from our implementation is sNaN handling.
+
+use super::super::Float;
+
+#[inline]
+pub fn fmaximum<F: Float>(x: F, y: F) -> F {
+    let res = if x.is_nan() {
+        x
+    } else if y.is_nan() {
+        y
+    } else if x > y || (y.to_bits() == F::NEG_ZERO.to_bits() && x.is_sign_positive()) {
+        x
+    } else {
+        y
+    };
+
+    // Canonicalize
+    res * F::ONE
+}