about summary refs log tree commit diff
path: root/sysdeps/ieee754
diff options
context:
space:
mode:
authorAndreas Jaeger <aj@suse.de>2001-06-04 08:31:38 +0000
committerAndreas Jaeger <aj@suse.de>2001-06-04 08:31:38 +0000
commit94a38ea3c432919dc1289957025f6fc5b2e3d7a7 (patch)
tree9f80bf6bc1d43497bf2acd4631f2c9655354351e /sysdeps/ieee754
parenteaeeb1eb428500658671f12aa4938543396ab7b9 (diff)
downloadglibc-94a38ea3c432919dc1289957025f6fc5b2e3d7a7.tar.gz
glibc-94a38ea3c432919dc1289957025f6fc5b2e3d7a7.tar.xz
glibc-94a38ea3c432919dc1289957025f6fc5b2e3d7a7.zip
128 bit sinh implementation.
Diffstat (limited to 'sysdeps/ieee754')
-rw-r--r--sysdeps/ieee754/ldbl-128/e_sinhl.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128/e_sinhl.c b/sysdeps/ieee754/ldbl-128/e_sinhl.c
new file mode 100644
index 0000000000..71e283d2de
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/e_sinhl.c
@@ -0,0 +1,105 @@
+/* e_sinhl.c -- long double version of e_sinh.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.
+ * ====================================================
+ */
+
+/* Changes for 128-bit long double contributed by
+   Stephen L. Moshier <moshier@na-net.ornl.gov> */
+
+/* __ieee754_sinhl(x)
+ * Method :
+ * mathematically sinh(x) if defined to be (exp(x)-exp(-x))/2
+ *      1. Replace x by |x| (sinhl(-x) = -sinhl(x)).
+ *      2.
+ *                                                   E + E/(E+1)
+ *          0        <= x <= 25     :  sinhl(x) := --------------, E=expm1l(x)
+ *                                                       2
+ *
+ *          25       <= x <= lnovft :  sinhl(x) := expl(x)/2
+ *          lnovft   <= x <= ln2ovft:  sinhl(x) := expl(x/2)/2 * expl(x/2)
+ *          ln2ovft  <  x           :  sinhl(x) := x*shuge (overflow)
+ *
+ * Special cases:
+ *      sinhl(x) is |x| if x is +INF, -INF, or NaN.
+ *      only sinhl(0)=0 is exact for finite x.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const long double one = 1.0, shuge = 1.0e4931L,
+ovf_thresh = 1.1357216553474703894801348310092223067821E4L;
+#else
+static long double one = 1.0, shuge = 1.0e4931L,
+ovf_thresh = 1.1357216553474703894801348310092223067821E4L;
+#endif
+
+#ifdef __STDC__
+long double
+__ieee754_sinhl (long double x)
+#else
+long double
+__ieee754_sinhl (x)
+     long double x;
+#endif
+{
+  long double t, w, h;
+  u_int32_t jx, ix;
+  ieee854_long_double_shape_type u;
+
+  /* Words of |x|. */
+  u.value = x;
+  jx = u.parts32.w0;
+  ix = jx & 0x7fffffff;
+
+  /* x is INF or NaN */
+  if (ix >= 0x7fff0000)
+    return x + x;
+
+  h = 0.5;
+  if (jx & 0x80000000)
+    h = -h;
+
+  /* Absolute value of x.  */
+  u.parts32.w0 = ix;
+
+  /* |x| in [0,40], return sign(x)*0.5*(E+E/(E+1))) */
+  if (ix <= 0x40044000)
+    {
+      if (ix < 0x3fc60000) /* |x| < 2^-57 */
+	if (shuge + x > one)
+	  return x;		/* sinh(tiny) = tiny with inexact */
+      t = __expm1l (u.value);
+      if (ix < 0x3fff0000)
+	return h * (2.0 * t - t * t / (t + one));
+      return h * (t + t / (t + one));
+    }
+
+  /* |x| in [40, log(maxdouble)] return 0.5*exp(|x|) */
+  if (ix <= 0x400c62e3) /* 11356.375 */
+    return h * __ieee754_expl (u.value);
+
+  /* |x| in [log(maxdouble), overflowthreshold]
+     Overflow threshold is log(2 * maxdouble).  */
+  if (u.value <= ovf_thresh)
+    {
+      w = __ieee754_expl (0.5 * u.value);
+      t = h * w;
+      return t * w;
+    }
+
+  /* |x| > overflowthreshold, sinhl(x) overflow */
+  return x * shuge;
+}