zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/build/uClibc/libm/e_atanh.c b/ap/build/uClibc/libm/e_atanh.c
new file mode 100644
index 0000000..5cf4da3
--- /dev/null
+++ b/ap/build/uClibc/libm/e_atanh.c
@@ -0,0 +1,79 @@
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/* __ieee754_atanh(x)
+ * Method :
+ *    1.Reduced x to positive by atanh(-x) = -atanh(x)
+ *    2.For x>=0.5
+ *                  1              2x                          x
+ *	atanh(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------)
+ *                  2             1 - x                      1 - x
+ *
+ * 	For x<0.5
+ *	atanh(x) = 0.5*log1p(2x+2x*x/(1-x))
+ *
+ * Special cases:
+ *	atanh(x) is NaN if |x| > 1 with signal;
+ *	atanh(NaN) is that NaN with no signal;
+ *	atanh(+-1) is +-INF with signal.
+ *
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+static const double one = 1.0, huge = 1e300;
+
+static const double zero = 0.0;
+
+double attribute_hidden __ieee754_atanh(double x)
+{
+	double t;
+	int32_t hx,ix;
+	u_int32_t lx;
+	EXTRACT_WORDS(hx,lx,x);
+	ix = hx&0x7fffffff;
+	if ((ix|((lx|(-lx))>>31))>0x3ff00000) /* |x|>1 */
+	    return (x-x)/(x-x);
+	if(ix==0x3ff00000)
+	    return x/zero;
+	if(ix<0x3e300000&&(huge+x)>zero) return x;	/* x<2**-28 */
+	SET_HIGH_WORD(x,ix);
+	if(ix<0x3fe00000) {		/* x < 0.5 */
+	    t = x+x;
+	    t = 0.5*log1p(t+t*x/(one-x));
+	} else
+	    t = 0.5*log1p((x+x)/(one-x));
+	if(hx>=0) return t; else return -t;
+}
+
+/*
+ * wrapper atanh(x)
+ */
+#ifndef _IEEE_LIBM
+double atanh(double x)
+{
+	double z, y;
+	z = __ieee754_atanh(x);
+	if (_LIB_VERSION == _IEEE_ || isnan(x))
+		return z;
+	y = fabs(x);
+	if (y >= 1.0) {
+		if (y > 1.0)
+			return __kernel_standard(x, x, 30); /* atanh(|x|>1) */
+		return __kernel_standard(x, x, 31); /* atanh(|x|==1) */
+	}
+	return z;
+}
+#else
+strong_alias(__ieee754_atanh, atanh)
+#endif
+libm_hidden_def(atanh)