2.5-18.1

1 files changed, 79 insertions, 0 deletions

diff --git a/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c b/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c
new file mode 100644
index 0000000000..a801bd6f74
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c
@@ -0,0 +1,79 @@
+/* @(#)e_atanh.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: e_atanh.c,v 1.8 1995/05/10 20:44:55 jtc Exp $";
+#endif
+
+/* __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"
+
+#ifdef __STDC__
+static const long double one = 1.0L, huge = 1e300L;
+#else
+static long double one = 1.0L, huge = 1e300L;
+#endif
+
+#ifdef __STDC__
+static const long double zero = 0.0L;
+#else
+static long double zero = 0.0L;
+#endif
+
+#ifdef __STDC__
+	long double __ieee754_atanhl(long double x)
+#else
+	long double __ieee754_atanhl(x)
+	long double x;
+#endif
+{
+	long double t;
+	int64_t hx,ix;
+	u_int64_t lx;
+	GET_LDOUBLE_WORDS64(hx,lx,x);
+	ix = hx&0x7fffffffffffffffLL;
+	if (ix >= 0x3ff0000000000000LL) { /* |x|>=1 */
+	    if (ix > 0x3ff0000000000000LL)
+	    	return (x-x)/(x-x);
+	    t = fabsl (x);
+	    if (t > one)
+		return (x-x)/(x-x);
+	    if (t == one)
+		return x/zero;
+	}
+	if(ix<0x3e20000000000000LL&&(huge+x)>zero) return x;	/* x<2**-29 */
+	x = fabsl (x);
+	if(ix<0x3fe0000000000000LL) {		/* x < 0.5 */
+	    t = x+x;
+	    t = 0.5*__log1pl(t+t*x/(one-x));
+	} else
+	    t = 0.5*__log1pl((x+x)/(one-x));
+	if(hx>=0) return t; else return -t;
+}