about summary refs log tree commit diff
path: root/sysdeps/libm-ieee754/s_rinttol.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/libm-ieee754/s_rinttol.c')
-rw-r--r--sysdeps/libm-ieee754/s_rinttol.c242
1 files changed, 242 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_rinttol.c b/sysdeps/libm-ieee754/s_rinttol.c
new file mode 100644
index 0000000000..257bdc744c
--- /dev/null
+++ b/sysdeps/libm-ieee754/s_rinttol.c
@@ -0,0 +1,242 @@
+/* Round argument to nearest integral value according to current rounding
+   direction.
+   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.  */
+static long double two52[2] =
+{
+  4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
+ -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
+};
+
+
+long int
+__rinttol (long double x)
+{
+  int32_t j0,sx;
+  u_int32_t i0,i1,i;
+  long double t, w;
+  long int result;
+
+  EXTRACT_WORDS (i0, i1, x);
+
+  sx = i0 >> 31;
+  j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
+
+  if (j0 < 20)
+    {
+      if (j0 < 0)
+	{
+	  if (((i0 & 0x7fffffff) | i1) == 0)
+	    /* The number is 0.  */
+	    result = 0;
+	  else
+	    {
+	      i1 |= i0;
+	      i0 &= 0xfffe0000;
+	      i0 |= ((i1 | -i1) >> 12) & 0x80000;
+	      SET_HIGH_WORD (x, i0);
+	      w = two52[sx] + x;
+	      t = w - two52[sx];
+	      GET_HIGH_WORD (i0, t);
+	      if ((i0 & 0x7fffffff) >= 0x3fff0000)
+		result = sx ? -1 : 1;
+	      else
+		result = 0;
+	    }
+	}
+      else
+	{
+	  u_int32_t i = 0x000fffff >> j0;
+	  if (((i0 & i) | i1) == 0)
+	    {
+	      /* X is not integral.  */
+	      i >>= 1;
+	      if (((i0 & i) | i1) != 0)
+		{
+		  if (j0 == 19)
+		    i1 = 0x40000000;
+		  else
+		    i0 = (i0 & (~i)) | (0x20000 >> j0);
+
+		  INSERT_WORDS (x, i0, i1);
+		  w = two52[sx] + x;
+		  x = w - two52[sx];
+		  EXTRACT_WORDS (i0, i1, x);
+
+		  j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
+		}
+	    }
+
+	  result = ((i0 >> (20 - j0)) & 0xfffff) | (0x00100000 >> (20 - j0));
+	  if (sx)
+	    result = -result;
+	}
+    }
+  else if ((unsigned int) j0 < sizeof (long int) * 8 && j0 < 53)
+    {
+      i = ((u_int32_t) (0xffffffff)) >> (j0 - 20);
+      if ((i1 & i) != 0)
+	{
+	  /* x is not integral.  */
+	  i >>= 1;
+	  if ((i1 & i) != 0)
+	    i1 = (i1 & (~i)) | (0x40000000 >> (j0 - 20));
+	}
+
+      INSERT_WORDS (x, i0, i1);
+      w = two52[sx] + x;
+      x = w - two52[sx];
+      EXTRACT_WORDS (i0, i1, x);
+
+      j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
+
+      result = i0 | 0x00100000;
+      if (j0 > 20)
+	{
+	  result <<= j0 - 20;
+	  result |= i1 >> (52 - j0);
+	}
+      if (sx)
+	result = -result;
+    }
+  else
+    /* Too large.  The number is either +-inf or NaN or it is too
+       large to be effected by rounding.  The standard leaves it
+       undefined what to return when the number is too large to fit in
+       a `long int'.  */
+    result = (long int) x;
+
+  return result;
+}
+
+#else
+static long double two63[2] =
+{
+  9.223372036854775808000000e+18, /* 0x403E, 0x00000000, 0x00000000 */
+ -9.223372036854775808000000e+18  /* 0xC03E, 0x00000000, 0x00000000 */
+};
+
+
+long int
+__rinttol (long double x)
+{
+  int32_t se,j0,sx;
+  u_int32_t i0,i1,i;
+  long int result;
+  long double w, t;
+
+  GET_LDOUBLE_WORDS (se, i0, i1, x);
+
+  sx = (se >> 15) & 1;
+  j0 = (se & 0x7fff) - 0x3fff;
+
+  if (j0 < 31)
+    {
+      if (j0 < 0)
+	{
+	  if (((se & 0x7fff) | i0 | i1) == 0)
+	    /* The number is 0.  */
+	    result = 0;
+	  else
+	    {
+	      i1 |= i0;
+	      i0 &= 0xe0000000;
+	      i0 |= (i1 | -i1) & 0x80000000;
+	      SET_LDOUBLE_MSW (x, i0);
+	      w = two63[sx] + x;
+	      t = w - two63[sx];
+	      GET_LDOUBLE_EXP (i0, t);
+	      if ((i0 & 0x7fff) >= 0x3fff)
+		result = sx ? -1 : 1;
+	      else
+		result = 0;
+	    }
+	}
+      else
+	{
+	  u_int32_t i = 0x7fffffff >> j0;
+	  if (((i0 & i) | i1) == 0)
+	    {
+	      /* X is not integral.  */
+	      i >>= 1;
+	      if (((i0 & i) | i1) != 0)
+		{
+		  if (j0 == 31)
+		    i1 = 0x40000000;
+		  else
+		    i0 = (i0 & (~i)) | (0x20000000 >> j0);
+
+		  SET_LDOUBLE_WORDS (x, se, i0, i1);
+		  w = two63[sx] + x;
+		  x = w - two63[sx];
+		  GET_LDOUBLE_WORDS (se, i0, i1, x);
+
+		  sx = (se >> 15) & 1;
+		  j0 = (se & 0x7fff) - 0x3fff;
+		}
+	    }
+
+
+	  result = i0 >> (31 - j0);
+	}
+    }
+  else if ((unsigned int) j0 < sizeof (long int) * 8 && j0 < 64)
+    {
+      i = ((u_int32_t) (0xffffffff)) >> (j0 - 31);
+      if ((i1 & i) != 0)
+	{
+	  /* x is not integral.  */
+	  i >>= 1;
+	  if ((i1 & i) != 0)
+	    i1 = (i1 & (~i)) | (0x40000000 >> (j0 - 31));
+	}
+
+      SET_LDOUBLE_WORDS (x, se, i0, i1);
+      w = two63[sx] + x;
+      x = w - two63[sx];
+      GET_LDOUBLE_WORDS (se, i0, i1, x);
+
+      j0 = (se & 0x7fff) - 0x3fff;
+
+      result = i0;
+      if (j0 > 31)
+	{
+	  result <<= j0 - 31;
+	  result |= i1 >> (63 - j0);
+	}
+    }
+  else
+    /* Too large.  The number is either +-inf or NaN or it is too
+       large to be effected by rounding.  The standard leaves it
+       undefined what to return when the number is too large to fit in
+       a `long int'.  */
+    result = (long int) x;
+
+  return result;
+}
+#endif
+
+weak_alias (__rinttol, rinttol)