Part I of port of Rhombus math library

git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5269 42af7a65-404d-4744-a932-0658087f49c3

nuttx/lib/math/lib_log2.c

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2009, 2010 Nick Johnson <nickbjohnson4224 at gmail.com>
+ * 
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <apps/math.h>
+#include <float.h>
+
+float log2f(float x) {
+	return (logf(x) / M_LN2);
+}
+
+double log2(double x) {
+	return (log(x) / M_LN2);
+}
+
+long double log2l(long double x) {
+	return (logl(x) / M_LN2);
+}