Initial Contributionandroid-1.0

1 files changed, 46 insertions, 0 deletions

diff --git a/libm/src/e_atanhf.c b/libm/src/e_atanhf.c
new file mode 100644
index 0000000..64ebd3d
--- /dev/null
+++ b/libm/src/e_atanhf.c
@@ -0,0 +1,46 @@
+/* e_atanhf.c -- float version of e_atanh.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#ifndef lint
+static char rcsid[] = "$FreeBSD: src/lib/msun/src/e_atanhf.c,v 1.6 2002/05/28 17:03:12 alfred Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+
+static const float one = 1.0, huge = 1e30;
+
+static const float zero = 0.0;
+
+float
+__ieee754_atanhf(float x)
+{
+	float t;
+	int32_t hx,ix;
+	GET_FLOAT_WORD(hx,x);
+	ix = hx&0x7fffffff;
+	if (ix>0x3f800000) 		/* |x|>1 */
+	    return (x-x)/(x-x);
+	if(ix==0x3f800000)
+	    return x/zero;
+	if(ix<0x31800000&&(huge+x)>zero) return x;	/* x<2**-28 */
+	SET_FLOAT_WORD(x,ix);
+	if(ix<0x3f000000) {		/* x < 0.5 */
+	    t = x+x;
+	    t = (float)0.5*log1pf(t+t*x/(one-x));
+	} else
+	    t = (float)0.5*log1pf((x+x)/(one-x));
+	if(hx>=0) return t; else return -t;
+}