diff --git a/libm/i387/s_copysignf.S b/libm/i387/s_copysignf.S
new file mode 100644
index 0000000..c3fc898
--- /dev/null
+++ b/libm/i387/s_copysignf.S
@@ -0,0 +1,19 @@
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ */
+
+#include <machine/asm.h>
+
+__FBSDID("$FreeBSD: src/lib/msun/i387/s_copysignf.S,v 1.1 2005/01/13 18:58:25 das Exp $");
+/* RCSID("$NetBSD: s_copysignf.S,v 1.3 1995/05/08 23:53:25 jtc Exp $") */
+
+ENTRY(copysignf)
+	movl	8(%esp),%edx
+	andl	$0x80000000,%edx
+	movl	4(%esp),%eax
+	andl	$0x7fffffff,%eax
+	orl	%edx,%eax
+	movl	%eax,4(%esp)
+	flds	4(%esp)
+	ret