1  /* Round float 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-float.h>
      24  #include <math-use-builtins.h>
      25  
      26  
      27  float
      28  __roundf (float x)
      29  {
      30  #if USE_ROUNDF_BUILTIN
      31    return __builtin_roundf (x);
      32  #else
      33    /* Use generic implementation.  */
      34    int32_t i0, j0;
      35  
      36    GET_FLOAT_WORD (i0, x);
      37    j0 = ((i0 >> 23) & 0xff) - 0x7f;
      38    if (j0 < 23)
      39      {
      40        if (j0 < 0)
      41  	{
      42  	  i0 &= 0x80000000;
      43  	  if (j0 == -1)
      44  	    i0 |= 0x3f800000;
      45  	}
      46        else
      47  	{
      48  	  uint32_t i = 0x007fffff >> j0;
      49  	  if ((i0 & i) == 0)
      50  	    /* X is integral.  */
      51  	    return x;
      52  
      53  	  i0 += 0x00400000 >> j0;
      54  	  i0 &= ~i;
      55  	}
      56      }
      57    else
      58      {
      59        if (j0 == 0x80)
      60  	/* Inf or NaN.  */
      61  	return x + x;
      62        else
      63  	return x;
      64      }
      65  
      66    SET_FLOAT_WORD (x, i0);
      67    return x;
      68  #endif /* ! USE_ROUNDF_BUILTIN  */
      69  }
      70  libm_alias_float (__round, round)