1 files changed, 13 insertions, 0 deletions
diff --git a/lib/libm/copysignf.c b/lib/libm/copysignf.c
new file mode 100644
index 00000000..d71c9a5f
--- /dev/null
+++ b/lib/libm/copysignf.c
@@ -0,0 +1,13 @@
+#include <math.h>
+#include <stdint.h>
+
+float copysignf(float x, float y)
+{
+	union {
+		float f;
+		uint32_t i;
+	} ux = { x }, uy = { y };
+	ux.i &= 0x7fffffff;
+	ux.i |= uy.i & 0x80000000;
+	return ux.f;
+}