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authorUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
committerUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
commitabfbdde177c3a7155070dda1b2cdc8292054cc26 (patch)
treee021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/ieee754/ldbl-96/s_roundl.c
parent86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff)
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Update.
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diff --git a/sysdeps/ieee754/ldbl-96/s_roundl.c b/sysdeps/ieee754/ldbl-96/s_roundl.c
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+/* Round long double to integer away from zero.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <math.h>
+
+#include "math_private.h"
+
+
+static const long double huge = 1.0e4930;
+
+
+long double
+__roundl (long double x)
+{
+  int32_t j0;
+  u_int32_t se, i1, i0;
+
+  GET_LDOUBLE_WORDS (se, i0, i1, x);
+  j0 = (se & 0x7fff) - 0x3fff;
+  if (j0 < 31)
+    {
+      if (j0 < 0)
+	{
+	  if (huge + x > 0.0)
+	    {
+	      se &= 0x8000;
+	      i0 = i1 = 0;
+	      if (j0 == -1)
+		{
+		  se |= 0x3fff;
+		  i0 = 0x80000000;
+		}
+	    }
+	}
+      else
+	{
+	  u_int32_t i = 0x7fffffff >> j0;
+	  if (((i0 & i) | i1) == 0)
+	    /* X is integral.  */
+	    return x;
+	  if (huge + x > 0.0)
+	    {
+	      /* Raise inexact if x != 0.  */
+	      u_int32_t j = i0 + (0x40000000 >> j0);
+	      if (j < i0)
+		se += 1;
+	      i0 = (j & ~i) | 0x80000000;
+	      i1 = 0;
+	    }
+	}
+    }
+  else if (j0 > 62)
+    {
+      if (j0 == 0x4000)
+	/* Inf or NaN.  */
+	return x + x;
+      else
+	return x;
+    }
+  else
+    {
+      u_int32_t i = 0xffffffff >> (j0 - 31);
+      if ((i1 & i) == 0)
+	/* X is integral.  */
+	return x;
+
+      if (huge + x > 0.0)
+	{
+	  /* Raise inexact if x != 0.  */
+	  u_int32_t j = i1 + (1 << (62 - j0));
+	  if (j < i1)
+	    {
+	      u_int32_t k = i0 + 1;
+	      if (k < i0)
+		{
+		  se += 1;
+		  k |= 0x80000000;
+		}
+	      i0 = k;
+	    }
+	  i1 = j;
+	}
+      i1 &= ~i;
+    }
+
+  SET_LDOUBLE_WORDS (x, se, i0, i1);
+  return x;
+}
+weak_alias (__roundl, roundl)