1 files changed, 69 insertions, 0 deletions
diff --git a/nuttx/libc/math/lib_asinl.c b/nuttx/libc/math/lib_asinl.c
new file mode 100644
index 000000000..19f284e53
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+++ b/nuttx/libc/math/lib_asinl.c
@@ -0,0 +1,69 @@
+/************************************************************************
+ * libc/math/lib_sinl.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) 2009-2011 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.
+ *
+ ************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+#include <float.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_LONG_DOUBLE
+long double asinl(long double x)
+{
+  long double y, y_sin, y_cos;
+
+  y = 0;
+
+  while (1)
+    {
+      y_sin = sinl(y);
+      y_cos = cosl(y);
+
+      if (y > M_PI_2 || y < -M_PI_2)
+        {
+          y = fmodl(y, M_PI);
+        }
+
+      if (y_sin + LDBL_EPSILON >= x && y_sin - LDBL_EPSILON <= x)
+        {
+          break;
+        }
+
+      y = y - (y_sin - x) / y_cos;
+    }
+
+  return y;
+}
+#endif