diff --git a/libm/src/s_ilogbf.c b/libm/src/s_ilogbf.c
new file mode 100644
index 0000000..3c9c4de
--- /dev/null
+++ b/libm/src/s_ilogbf.c
@@ -0,0 +1,41 @@
+/* s_ilogbf.c -- float version of s_ilogb.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#ifndef lint
+static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_ilogbf.c,v 1.7 2004/10/09 17:14:28 stefanf Exp $";
+#endif
+
+#include <limits.h>
+
+#include "math.h"
+#include "math_private.h"
+
+	int ilogbf(float x)
+{
+	int32_t hx,ix;
+
+	GET_FLOAT_WORD(hx,x);
+	hx &= 0x7fffffff;
+	if(hx<0x00800000) {
+	    if(hx==0)
+		return FP_ILOGB0;
+	    else			/* subnormal x */
+	        for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;
+	    return ix;
+	}
+	else if (hx<0x7f800000) return (hx>>23)-127;
+	else if (hx>0x7f800000) return FP_ILOGBNAN;
+	else return INT_MAX;
+}