From abfbdde177c3a7155070dda1b2cdc8292054cc26 Mon Sep 17 00:00:00 2001
From: Ulrich Drepper <drepper@redhat.com>
Date: Wed, 14 Jul 1999 00:54:57 +0000
Subject: Update.

---
 sysdeps/ieee754/ldbl-96/s_tanhl.c | 95 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 sysdeps/ieee754/ldbl-96/s_tanhl.c

(limited to 'sysdeps/ieee754/ldbl-96/s_tanhl.c')

diff --git a/sysdeps/ieee754/ldbl-96/s_tanhl.c b/sysdeps/ieee754/ldbl-96/s_tanhl.c
new file mode 100644
index 0000000000..1e3dc3b613
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-96/s_tanhl.c
@@ -0,0 +1,95 @@
+/* s_tanhl.c -- long double version of s_tanh.c.
+ * Conversion to long double by Ulrich Drepper,
+ * Cygnus Support, drepper@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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: $";
+#endif
+
+/* tanhl(x)
+ * Return the Hyperbolic Tangent of x
+ *
+ * Method :
+ *				        x    -x
+ *				       e  - e
+ *	0. tanhl(x) is defined to be -----------
+ *				        x    -x
+ *				       e  + e
+ *	1. reduce x to non-negative by tanhl(-x) = -tanhl(x).
+ *	2.  0      <= x <= 2**-55 : tanhl(x) := x*(one+x)
+ *					         -t
+ *	    2**-55 <  x <=  1     : tanhl(x) := -----; t = expm1l(-2x)
+ *					        t + 2
+ *						      2
+ *	    1      <= x <=  23.0  : tanhl(x) := 1-  ----- ; t=expm1l(2x)
+ *						    t + 2
+ *	    23.0   <  x <= INF    : tanhl(x) := 1.
+ *
+ * Special cases:
+ *	tanhl(NaN) is NaN;
+ *	only tanhl(0)=0 is exact for finite argument.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const long double one=1.0, two=2.0, tiny = 1.0e-4900L;
+#else
+static long double one=1.0, two=2.0, tiny = 1.0e-4900L;
+#endif
+
+#ifdef __STDC__
+	long double __tanhl(long double x)
+#else
+	long double __tanhl(x)
+	long double x;
+#endif
+{
+	long double t,z;
+	int32_t se;
+	u_int32_t j0,j1,ix;
+
+    /* High word of |x|. */
+	GET_LDOUBLE_WORDS(se,j0,j1,x);
+	ix = se&0x7fff;
+
+    /* x is INF or NaN */
+	if(ix==0x7fff) {
+	    /* for NaN it's not important which branch: tanhl(NaN) = NaN */
+	    if (se&0x8000) return one/x-one;	/* tanhl(-inf)= -1; */
+	    else           return one/x+one;	/* tanhl(+inf)=+1 */
+	}
+
+    /* |x| < 23 */
+	if (ix < 0x4003 || (ix == 0x4003 && j0 < 0xb8000000u)) {/* |x|<23 */
+	    if ((ix|j0|j1) == 0)
+		return x;		/* x == +- 0 */
+	    if (ix<0x3fc8) 		/* |x|<2**-55 */
+		return x*(one+x);    	/* tanh(small) = small */
+	    if (ix>=0x3fff) {	/* |x|>=1  */
+		t = __expm1l(two*fabsl(x));
+		z = one - two/(t+two);
+	    } else {
+	        t = __expm1l(-two*fabsl(x));
+	        z= -t/(t+two);
+	    }
+    /* |x| > 23, return +-1 */
+	} else {
+	    z = one - tiny;		/* raised inexact flag */
+	}
+	return (se>0x7fff)? -z: z;
+}
+weak_alias (__tanhl, tanhl)
-- 
cgit 1.4.1