1 files changed, 22 insertions, 0 deletions
diff --git a/library/compiler-builtins/libm/src/math/exp10f.rs b/library/compiler-builtins/libm/src/math/exp10f.rs
new file mode 100644
index 00000000000..0520a41f2e9
--- /dev/null
+++ b/library/compiler-builtins/libm/src/math/exp10f.rs
@@ -0,0 +1,22 @@
+use super::{exp2, exp2f, modff};
+
+const LN10_F32: f32 = 3.32192809488736234787031942948939;
+const LN10_F64: f64 = 3.32192809488736234787031942948939;
+const P10: &[f32] =
+    &[1e-7, 1e-6, 1e-5, 1e-4, 1e-3, 1e-2, 1e-1, 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7];
+
+/// Calculates 10 raised to the power of `x` (f32).
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub fn exp10f(x: f32) -> f32 {
+    let (mut y, n) = modff(x);
+    let u = n.to_bits();
+    /* fabsf(n) < 8 without raising invalid on nan */
+    if ((u >> 23) & 0xff) < 0x7f + 3 {
+        if y == 0.0 {
+            return i!(P10, ((n as isize) + 7) as usize);
+        }
+        y = exp2f(LN10_F32 * y);
+        return y * i!(P10, ((n as isize) + 7) as usize);
+    }
+    return exp2(LN10_F64 * (x as f64)) as f32;
+}