From 50438b51aa0af3f6453f334d3868f0a87eb94a89 Mon Sep 17 00:00:00 2001
From: Jeff Epler <jepler@gmail.com>
Date: Tue, 4 Feb 2020 09:41:44 -0600
Subject: [PATCH] libm: Provide log2f

---
 lib/libm/math.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/libm/math.c b/lib/libm/math.c
index 39c6a68a5e..0e53563bcb 100644
--- a/lib/libm/math.c
+++ b/lib/libm/math.c
@@ -50,6 +50,9 @@ float copysignf(float x, float y) {
 
 static const float _M_LN10 = 2.30258509299404; // 0x40135d8e
 float log10f(float x) { return logf(x) / (float)_M_LN10; }
+#undef _M_LN2
+static const float _M_LN2 = 0.6931472;
+float log2f(float x) { return logf(x) / (float)_M_LN2; }
 
 float tanhf(float x) {
     if (isinf(x)) {