Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 98 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/ieee754/dbl-64/s_tanh.c b/REORG.TODO/sysdeps/ieee754/dbl-64/s_tanh.c
new file mode 100644
index 0000000000..344a2f0330
--- /dev/null
+++ b/REORG.TODO/sysdeps/ieee754/dbl-64/s_tanh.c
@@ -0,0 +1,98 @@
+/* @(#)s_tanh.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: s_tanh.c,v 1.7 1995/05/10 20:48:22 jtc Exp $";
+#endif
+
+/* Tanh(x)
+ * Return the Hyperbolic Tangent of x
+ *
+ * Method :
+ *				       x    -x
+ *				      e  - e
+ *	0. tanh(x) is defined to be -----------
+ *				       x    -x
+ *				      e  + e
+ *	1. reduce x to non-negative by tanh(-x) = -tanh(x).
+ *	2.  0      <= x <= 2**-55 : tanh(x) := x*(one+x)
+ *					        -t
+ *	    2**-55 <  x <=  1     : tanh(x) := -----; t = expm1(-2x)
+ *					       t + 2
+ *						     2
+ *	    1      <= x <=  22.0  : tanh(x) := 1-  ----- ; t=expm1(2x)
+ *						   t + 2
+ *	    22.0   <  x <= INF    : tanh(x) := 1.
+ *
+ * Special cases:
+ *	tanh(NaN) is NaN;
+ *	only tanh(0)=0 is exact for finite argument.
+ */
+
+#include <float.h>
+#include <math.h>
+#include <math_private.h>
+
+static const double one = 1.0, two = 2.0, tiny = 1.0e-300;
+
+double
+__tanh (double x)
+{
+  double t, z;
+  int32_t jx, ix, lx;
+
+  /* High word of |x|. */
+  EXTRACT_WORDS (jx, lx, x);
+  ix = jx & 0x7fffffff;
+
+  /* x is INF or NaN */
+  if (ix >= 0x7ff00000)
+    {
+      if (jx >= 0)
+	return one / x + one;               /* tanh(+-inf)=+-1 */
+      else
+	return one / x - one;               /* tanh(NaN) = NaN */
+    }
+
+  /* |x| < 22 */
+  if (ix < 0x40360000)                  /* |x|<22 */
+    {
+      if ((ix | lx) == 0)
+	return x;                       /* x == +-0 */
+      if (ix < 0x3c800000)              /* |x|<2**-55 */
+	{
+	  math_check_force_underflow (x);
+	  return x * (one + x);           /* tanh(small) = small */
+	}
+      if (ix >= 0x3ff00000)             /* |x|>=1  */
+	{
+	  t = __expm1 (two * fabs (x));
+	  z = one - two / (t + two);
+	}
+      else
+	{
+	  t = __expm1 (-two * fabs (x));
+	  z = -t / (t + two);
+	}
+      /* |x| > 22, return +-1 */
+    }
+  else
+    {
+      z = one - tiny;                   /* raised inexact flag */
+    }
+  return (jx >= 0) ? z : -z;
+}
+weak_alias (__tanh, tanh)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__tanh, __tanhl)
+weak_alias (__tanh, tanhl)
+#endif