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-rw-r--r--sysdeps/libm-ieee754/s_roundtol.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_roundtol.c b/sysdeps/libm-ieee754/s_roundtol.c
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+/* Round long double value to long int.
+   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"
+
+
+#ifdef NO_LONG_DOUBLE
+/* The `long double' is in fact the IEEE `double' type.  */
+
+long int
+__roundtol (long double x)
+{
+  int32_t j0;
+  u_int32_t i1, i0;
+  long int result;
+
+  EXTRACT_WORDS (i0, i1, x);
+  j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
+  if (j0 < 20)
+    {
+      if (j0 < 0)
+	result = j0 < -1 ? 0 : ((i0 & 0x80000000) ? -1 : 1);
+      else
+	{
+	  u_int32_t i = 0xfffff >> j0;
+	  if (((i0 & i) | i1) == 0)
+	    result = (long int) ((i0 & 0xfffff) | 0x100000) >> j0;
+	  else
+	    {
+	      /* X is not integral.  */
+	      u_int32_t j = i0 + (0x80000 >> j0);
+              if (j < i0)
+		result = (long int) 0x80000 >> (20 - j0);
+	      else
+		result = (j | 0x100000) >> (20 - j0);
+	    }
+	}
+    }
+  else if (j0 >= 8 * sizeof (long int) || j0 > 51)
+    {
+      /* The number is too large.  It is left implementation defined
+	 what happens.  */
+      result = (long int) x;
+    }
+  else
+    {
+      i = ((u_int32_t) (0xffffffff)) >> (j0 - 20);
+      if ((i1 & i) != 0)
+	{
+	  /* x is not integral.  */
+	  u_int32_t j = i1 + (0x80000000 >> (j0 - 20));
+	  if (j < i1)
+	    {
+	      j = i0 + 1;
+	      if ((j & 0xfffff) == 0)
+		{
+		  if (sizeof (long int) <= 4)
+		    /* Overflow.  */
+		    result = (long int) x;
+		  else
+		    result = 1l << (j0 + 1);
+		}
+	      else
+		result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31);
+	    }
+	  else
+	    {
+	      result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31);
+	      if (sizeof (long int) > 4 && j0 > 31)
+		result |= j >> (63 - j0);
+	    }
+	}
+      else
+	{
+	  result = (long int) ((i0 & 0xfffff) | 0x100000) << (j0 - 31);
+	  if (sizeof (long int) > 4 && j0 > 31)
+	    result |= j >> (63 - j0);
+	}
+    }
+
+  return i0 & 0x80000000 ? -result : result;
+}
+#else
+long int
+__roundtol (long double x)
+{
+  int32_t j0;
+  u_int32_t se, i1, i0;
+  long int result;
+
+  GET_LDOUBLE_WORDS (se, i0, i1, x);
+  j0 = (se & 0x7fff) - 0x3fff;
+  if (j0 < 31)
+    {
+      if (j0 < 0)
+	result = j0 < -1 ? 0 : 1;
+      else
+	{
+	  u_int32_t i = 0x7fffffff >> j0;
+	  if (((i0 & i) | i1) == 0)
+	    result = (long int) i0 >> j0;
+	  else
+	    {
+	      /* X is not integral.  */
+	      u_int32_t j = i0 + (0x40000000 >> j0);
+              if (j < i0)
+		result = 0x80000000l >> (30 - j0);
+	      else
+		result = j >> (31 - j0);
+	    }
+	}
+    }
+  else if ((unsigned int) j0 >= 8 * sizeof (long int) || j0 > 62)
+    {
+      /* The number is too large.  It is left implementation defined
+	 what happens.  */
+      result = (long int) x;
+    }
+  else
+    {
+      u_int32_t i = ((u_int32_t) (0xffffffff)) >> (j0 - 31);
+      if ((i1 & i) != 0)
+	{
+	  /* x is not integral.  */
+	  u_int32_t j = i1 + (0x80000000 >> (j0 - 31));
+	  if (j < i1)
+	    {
+	      j = i0 + 1;
+	      if (j == 0)
+		{
+		  if (sizeof (long int) <= 4)
+		    /* Overflow.  */
+		    result = (long int) x;
+		  else
+		    result = 1l << (j0 + 1);
+		}
+	      else
+		result = (long int) i0 << (j0 - 31);
+	    }
+	  else
+	    {
+	      result = (long int) i0 << (j0 - 31);
+	      if (sizeof (long int) > 4 && j0 > 31)
+		result |= j >> (63 - j0);
+	    }
+	}
+      else
+	{
+	  result = (long int) i0 << (j0 - 31);
+	  if (sizeof (long int) > 4 && j0 > 31)
+	    result |= i1 >> (63 - j0);
+	}
+    }
+
+  return se & 0x8000 ? -result : result;
+}
+#endif
+weak_alias (__roundtol, roundtol)