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glibc  2.9
Functions | Variables
s_roundl.c File Reference
#include <math.h>
#include "math_private.h"

Go to the source code of this file.

Functions

long double __roundl (long double x)

Variables

static const long double huge = 1.0e4930L

Function Documentation

long double __roundl ( long double  x)

Definition at line 30 of file s_roundl.c.

{
  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;
}

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Variable Documentation

const long double huge = 1.0e4930L [static]

Definition at line 26 of file s_roundl.c.