Add support for inverse hyperbolic functions. From Brennan Ashton

11 files changed, 507 insertions, 3 deletions

diff --git a/nuttx/include/nuttx/math.h b/nuttx/include/nuttx/math.h
index 977d8cac9..35369ba53 100644
--- a/nuttx/include/nuttx/math.h
+++ b/nuttx/include/nuttx/math.h
@@ -333,6 +333,30 @@ double      tanh  (double x);
 long double tanhl (long double x);
 #endif
 
+float       asinhf (float x);
+#if CONFIG_HAVE_DOUBLE
+double      asinh  (double x);
+#endif
+#ifdef CONFIG_HAVE_LONG_DOUBLE
+long double asinhl (long double x);
+#endif
+
+float       acoshf (float x);
+#if CONFIG_HAVE_DOUBLE
+double      acosh  (double x);
+#endif
+#ifdef CONFIG_HAVE_LONG_DOUBLE
+long double acoshl (long double x);
+#endif
+
+float       atanhf (float x);
+#if CONFIG_HAVE_DOUBLE
+double      atanh  (double x);
+#endif
+#ifdef CONFIG_HAVE_LONG_DOUBLE
+long double atanhl (long double x);
+#endif
+
 #if defined(__cplusplus)
 }
 #endif
diff --git a/nuttx/libc/math/Make.defs b/nuttx/libc/math/Make.defs
index 768ea8d6f..b490acb02 100644
--- a/nuttx/libc/math/Make.defs
+++ b/nuttx/libc/math/Make.defs
@@ -41,19 +41,19 @@ CSRCS += lib_acosf.c lib_asinf.c lib_atan2f.c lib_atanf.c lib_ceilf.c lib_cosf.c
 CSRCS += lib_coshf.c  lib_expf.c lib_fabsf.c lib_floorf.c lib_fmodf.c lib_frexpf.c
 CSRCS += lib_ldexpf.c lib_logf.c lib_log10f.c lib_log2f.c lib_modff.c lib_powf.c
 CSRCS += lib_rintf.c lib_roundf.c lib_sinf.c lib_sinhf.c lib_sqrtf.c lib_tanf.c
-CSRCS += lib_tanhf.c
+CSRCS += lib_tanhf.c lib_asinhf.c lib_acoshf.c lib_atanhf.c
 
 CSRCS += lib_acos.c lib_asin.c lib_atan.c lib_atan2.c lib_ceil.c lib_cos.c
 CSRCS += lib_cosh.c lib_exp.c lib_fabs.c lib_floor.c lib_fmod.c lib_frexp.c
 CSRCS += lib_ldexp.c lib_log.c lib_log10.c lib_log2.c lib_modf.c lib_pow.c
 CSRCS += lib_rint.c lib_round.c lib_sin.c lib_sinh.c lib_sqrt.c lib_tan.c
-CSRCS += lib_tanh.c
+CSRCS += lib_tanh.c lib_asinh.c lib_acosh.c lib_atanh.c
 
 CSRCS += lib_acosl.c lib_asinl.c lib_atan2l.c lib_atanl.c lib_ceill.c lib_cosl.c
 CSRCS += lib_coshl.c lib_expl.c lib_fabsl.c lib_floorl.c lib_fmodl.c lib_frexpl.c
 CSRCS += lib_ldexpl.c lib_logl.c lib_log10l.c lib_log2l.c lib_modfl.c lib_powl.c
 CSRCS += lib_rintl.c lib_roundl.c lib_sinl.c lib_sinhl.c lib_sqrtl.c lib_tanl.c
-CSRCS += lib_tanhl.c
+CSRCS += lib_tanhl.c lib_asinhl.c lib_acoshl.c lib_atanhl.c
 
 CSRCS += lib_libexpi.c lib_libsqrtapprox.c
 
diff --git a/nuttx/libc/math/lib_acosh.c b/nuttx/libc/math/lib_acosh.c
new file mode 100644
index 000000000..cd9fde559
--- /dev/null
+++ b/nuttx/libc/math/lib_acosh.c
@@ -0,0 +1,54 @@
+/************************************************************************
+ * libc/math/lib_acosh.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_DOUBLE
+double acosh(double x)
+{
+  return log(x + sqrt(x * x - 1));
+}
+#endif
diff --git a/nuttx/libc/math/lib_acoshf.c b/nuttx/libc/math/lib_acoshf.c
new file mode 100644
index 000000000..fa5c9549d
--- /dev/null
+++ b/nuttx/libc/math/lib_acoshf.c
@@ -0,0 +1,52 @@
+/************************************************************************
+ * libc/math/lib_acoshf.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+float acoshf(float x)
+{
+  return logf(x + sqrtf(x * x - 1));
+}
diff --git a/nuttx/libc/math/lib_acoshl.c b/nuttx/libc/math/lib_acoshl.c
new file mode 100644
index 000000000..bc2cd31da
--- /dev/null
+++ b/nuttx/libc/math/lib_acoshl.c
@@ -0,0 +1,54 @@
+/************************************************************************
+ * libc/math/lib_acoshl.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_LONG_DOUBLE
+long double acoshl(long double x)
+{
+  return logl(x + sqrtl(x * x - 1));
+}
+#endif
diff --git a/nuttx/libc/math/lib_asinh.c b/nuttx/libc/math/lib_asinh.c
new file mode 100644
index 000000000..7b573fcdd
--- /dev/null
+++ b/nuttx/libc/math/lib_asinh.c
@@ -0,0 +1,54 @@
+/************************************************************************
+ * libc/math/lib_asinh.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_DOUBLE
+double asinh(double x)
+{
+  return log(x + sqrt(x * x + 1));
+}
+#endif
diff --git a/nuttx/libc/math/lib_asinhf.c b/nuttx/libc/math/lib_asinhf.c
new file mode 100644
index 000000000..37141a65c
--- /dev/null
+++ b/nuttx/libc/math/lib_asinhf.c
@@ -0,0 +1,52 @@
+/************************************************************************
+ * libc/math/lib_asinhf.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+float asinhf(float x)
+{
+  return logf(x + sqrtf(x * x + 1));
+}
diff --git a/nuttx/libc/math/lib_asinhl.c b/nuttx/libc/math/lib_asinhl.c
new file mode 100644
index 000000000..b2fb201a3
--- /dev/null
+++ b/nuttx/libc/math/lib_asinhl.c
@@ -0,0 +1,54 @@
+/************************************************************************
+ * libc/math/lib_asinhl.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_LONG_DOUBLE
+long double asinhl(long double x)
+{
+  return logl(x + sqrtl(x * x + 1));
+}
+#endif
diff --git a/nuttx/libc/math/lib_atanh.c b/nuttx/libc/math/lib_atanh.c
new file mode 100644
index 000000000..9932a5e9b
--- /dev/null
+++ b/nuttx/libc/math/lib_atanh.c
@@ -0,0 +1,54 @@
+/************************************************************************
+ * libc/math/lib_atanh.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_DOUBLE
+double atanh(double x)
+{
+  return 0.5 * log((1 + x) / (1 - x));
+}
+#endif
diff --git a/nuttx/libc/math/lib_atanhf.c b/nuttx/libc/math/lib_atanhf.c
new file mode 100644
index 000000000..a49ba995c
--- /dev/null
+++ b/nuttx/libc/math/lib_atanhf.c
@@ -0,0 +1,52 @@
+/************************************************************************
+ * libc/math/lib_atanhf.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+float atanhf(float x)
+{
+  return 0.5 * logf((1 + x) / (1 - x));
+}
diff --git a/nuttx/libc/math/lib_atanhl.c b/nuttx/libc/math/lib_atanhl.c
new file mode 100644
index 000000000..77a187e51
--- /dev/null
+++ b/nuttx/libc/math/lib_atanhl.c
@@ -0,0 +1,54 @@
+/************************************************************************
+ * libc/math/lib_atanhl.c
+ *
+ *   Copyright (C) 2015 Brennan Ashton. All rights reserved.
+ *   Author: Brennan Ashton <bashton@brennanashton.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_DOUBLE
+long double atanhl(long double x)
+{
+  return 0.5 * logl((1 + x) / (1 - x));
+}
+#endif