1 files changed, 29 insertions, 19 deletions
diff --git a/nuttx/lib/math/lib_tanh.c b/nuttx/lib/math/lib_tanh.c
index c6a1a1c87..5cc1d9176 100644
--- a/nuttx/lib/math/lib_tanh.c
+++ b/nuttx/lib/math/lib_tanh.c
@@ -1,4 +1,14 @@
-/*
+/************************************************************************
+ * lib/math/lib_tanh.c
+ *
+ * This file is a part of NuttX:
+ *
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *   Ported by: Darcy Gong
+ *
+ * It derives from the Rhombs OS math library by Nick Johnson which has
+ * a compatibile, MIT-style license:
+ *
  * Copyright (C) 2009, 2010 Nick Johnson <nickbjohnson4224 at gmail.com>
  * 
  * Permission to use, copy, modify, and distribute this software for any
@@ -12,28 +22,28 @@
  * 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>
+/************************************************************************
+ * Included Files
+ ************************************************************************/
 
-float tanhf(float x) {
-	float x0 = expf(x);
-	float x1 = 1.0 / x0;
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
 
-	return ((x0 + x1) / (x0 - x1));
-}
-
-double tanh(double x) {
-	double x0 = exp(x);
-	double x1 = 1.0 / x0;
+#include <math.h>
 
-	return ((x0 + x1) / (x0 - x1));
-}
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
 
-long double tanhl(long double x) {
-	long double x0 = exp(x);
-	long double x1 = 1.0 / x0;
+#if CONFIG_HAVE_DOUBLE
+double tanh(double x)
+{
+  double x0 = exp(x);
+  double x1 = 1.0 / x0;
 
-	return ((x0 + x1) / (x0 - x1));
+  return ((x0 + x1) / (x0 - x1));
 }
+#endif