1 files changed, 36 insertions, 0 deletions
diff --git a/library/compiler-builtins/libm/src/math/coshf.rs b/library/compiler-builtins/libm/src/math/coshf.rs
new file mode 100644
index 00000000000..567a24410e7
--- /dev/null
+++ b/library/compiler-builtins/libm/src/math/coshf.rs
@@ -0,0 +1,36 @@
+use super::{expf, expm1f, k_expo2f};
+
+/// Hyperbolic cosine (f64)
+///
+/// Computes the hyperbolic cosine of the argument x.
+/// Is defined as `(exp(x) + exp(-x))/2`
+/// Angles are specified in radians.
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub fn coshf(mut x: f32) -> f32 {
+    let x1p120 = f32::from_bits(0x7b800000); // 0x1p120f === 2 ^ 120
+
+    /* |x| */
+    let mut ix = x.to_bits();
+    ix &= 0x7fffffff;
+    x = f32::from_bits(ix);
+    let w = ix;
+
+    /* |x| < log(2) */
+    if w < 0x3f317217 {
+        if w < (0x3f800000 - (12 << 23)) {
+            force_eval!(x + x1p120);
+            return 1.;
+        }
+        let t = expm1f(x);
+        return 1. + t * t / (2. * (1. + t));
+    }
+
+    /* |x| < log(FLT_MAX) */
+    if w < 0x42b17217 {
+        let t = expf(x);
+        return 0.5 * (t + 1. / t);
+    }
+
+    /* |x| > log(FLT_MAX) or nan */
+    k_expo2f(x)
+}