2.5-18.1

1 files changed, 125 insertions, 0 deletions

diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c b/sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c
new file mode 100644
index 0000000000..2561fda329
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c
@@ -0,0 +1,125 @@
+/* Round to int long double floating-point values without raising inexact.
+   IBM extended format long double version.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+/* This has been coded in assembler because GCC makes such a mess of it
+   when it's coded in C.  */
+
+#include <math.h>
+#include <fenv.h>
+#include <math_ldbl_opt.h>
+#include <float.h>
+#include <ieee754.h>
+
+
+#ifdef __STDC__
+long double
+__nearbyintl (long double x)
+#else
+long double
+__nearbyintl (x)
+     long double x;
+#endif
+{
+  fenv_t env;
+  static const long double TWO52 = 4503599627370496.0L;
+  union ibm_extended_long_double u;
+  u.d = x;
+
+  if (fabs (u.dd[0]) < TWO52)
+    {
+      double high = u.dd[0];
+      feholdexcept (&env);
+      if (high > 0.0)
+	{
+	  high += TWO52;
+	  high -= TWO52;
+          if (high == -0.0) high = 0.0;
+	}
+      else if (high < 0.0)
+	{
+	  high -= TWO52;
+	  high += TWO52;
+          if (high == 0.0) high = -0.0;
+	}
+      u.dd[0] = high;
+      u.dd[1] = 0.0;
+      fesetenv (&env);
+    }
+  else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
+    {
+      double high, low, tau;
+      /* In this case we have to round the low double and handle any
+         adjustment to the high double that may be caused by rounding
+         (up).  This is complicated by the fact that the high double
+         may already be rounded and the low double may have the
+         opposite sign to compensate.  */
+      feholdexcept (&env);
+      if (u.dd[0] > 0.0)
+	{
+	  if (u.dd[1] > 0.0)
+	    {
+	      /* If the high/low doubles are the same sign then simply
+	         round the low double.  */
+	      high = u.dd[0];
+	      low = u.dd[1];
+	    }
+	  else if (u.dd[1] < 0.0)
+	    {
+	      /* Else the high double is pre rounded and we need to
+	         adjust for that.  */
+	      
+	      tau = nextafter (u.dd[0], 0.0);
+	      tau = (u.dd[0] - tau) * 2.0;
+	      high = u.dd[0] - tau;
+	      low = u.dd[1] + tau;
+	    }
+	  low += TWO52;
+	  low -= TWO52;
+	}
+      else if (u.dd[0] < 0.0)
+	{
+	  if (u.dd[1] < 0.0)
+	    {
+	      /* If the high/low doubles are the same sign then simply
+	         round the low double.  */
+	      high = u.dd[0];
+	      low = u.dd[1];
+	    }
+	  else if (u.dd[1] > 0.0)
+	    {
+	      /* Else the high double is pre rounded and we need to
+	         adjust for that.  */
+	      tau = nextafter (u.dd[0], 0.0);
+	      tau = (u.dd[0] - tau) * 2.0;
+	      high = u.dd[0] - tau;
+	      low = u.dd[1] + tau;
+	    }
+	  low = TWO52 - low;
+	  low = -(low - TWO52);
+	}
+      u.dd[0] = high + low;
+      u.dd[1] = high - u.dd[0] + low;
+      fesetenv (&env);
+    }
+
+  return u.d;
+}
+
+long_double_symbol (libm, __nearbyintl, nearbyintl);