1  /* Copyright (C) 2013-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Library General Public License as
       6     published by the Free Software Foundation; either version 2 of the
       7     License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Library General Public License for more details.
      13  
      14     You should have received a copy of the GNU Library General Public
      15     License along with the GNU C Library; see the file COPYING.LIB.  If
      16     not, see <https://www.gnu.org/licenses/>.  */
      17  
      18  /* ISA 2.07 provides fast GPR to FP instruction (mfvsr{d,wz}) which make
      19     generic implementation faster.  Also disables for old ISAs that do not
      20     have ceil/floor instructions.  */
      21  #if defined(_ARCH_PWR8) || !defined(_ARCH_PWR5X)
      22  # include <sysdeps/ieee754/ldbl-opt/s_modf.c>
      23  #else
      24  # include <math.h>
      25  # include <math_ldbl_opt.h>
      26  # include <libm-alias-double.h>
      27  
      28  double
      29  __modf (double x, double *iptr)
      30  {
      31    if (__builtin_isinf (x))
      32      {
      33        *iptr = x;
      34        return copysign (0.0, x);
      35      }
      36    else if (__builtin_isnan (x))
      37      {
      38        *iptr = NAN;
      39        return NAN;
      40      }
      41  
      42    if (x >= 0.0)
      43      {
      44        *iptr = floor (x);
      45        return copysign (x - *iptr, x);
      46      }
      47    else
      48      {
      49        *iptr = ceil (x);
      50        return copysign (x - *iptr, x);
      51      }
      52  }
      53  # ifndef __modf
      54  libm_alias_double (__modf, modf)
      55  #  if LONG_DOUBLE_COMPAT (libc, GLIBC_2_0)
      56  compat_symbol (libc, __modf, modfl, GLIBC_2_0);
      57  #  endif
      58  # endif
      59  #endif