1  /* Round long double to integer away from zero.
       2     Copyright (C) 1997-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #define NO_MATH_REDIRECT
      20  #include <math.h>
      21  
      22  #include <math_private.h>
      23  #include <libm-alias-ldouble.h>
      24  
      25  
      26  long double
      27  __roundl (long double x)
      28  {
      29    int32_t j0;
      30    uint32_t se, i1, i0;
      31  
      32    GET_LDOUBLE_WORDS (se, i0, i1, x);
      33    j0 = (se & 0x7fff) - 0x3fff;
      34    if (j0 < 31)
      35      {
      36        if (j0 < 0)
      37  	{
      38  	  se &= 0x8000;
      39  	  i0 = i1 = 0;
      40  	  if (j0 == -1)
      41  	    {
      42  	      se |= 0x3fff;
      43  	      i0 = 0x80000000;
      44  	    }
      45  	}
      46        else
      47  	{
      48  	  uint32_t i = 0x7fffffff >> j0;
      49  	  if (((i0 & i) | i1) == 0)
      50  	    /* X is integral.  */
      51  	    return x;
      52  
      53  	  uint32_t j = i0 + (0x40000000 >> j0);
      54  	  if (j < i0)
      55  	    se += 1;
      56  	  i0 = (j & ~i) | 0x80000000;
      57  	  i1 = 0;
      58  	}
      59      }
      60    else if (j0 > 62)
      61      {
      62        if (j0 == 0x4000)
      63  	/* Inf or NaN.  */
      64  	return x + x;
      65        else
      66  	return x;
      67      }
      68    else
      69      {
      70        uint32_t i = 0xffffffff >> (j0 - 31);
      71        if ((i1 & i) == 0)
      72  	/* X is integral.  */
      73  	return x;
      74  
      75        uint32_t j = i1 + (1 << (62 - j0));
      76        if (j < i1)
      77  	{
      78  	  uint32_t k = i0 + 1;
      79  	  if (k < i0)
      80  	    {
      81  	      se += 1;
      82  	      k |= 0x80000000;
      83  	    }
      84  	  i0 = k;
      85  	}
      86        i1 = j;
      87        i1 &= ~i;
      88      }
      89  
      90    SET_LDOUBLE_WORDS (x, se, i0, i1);
      91    return x;
      92  }
      93  libm_alias_ldouble (__round, round)