1  /* Copyright (C) 2011-2023 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 Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the 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     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <math.h>
      19  #include <math_private.h>
      20  #include <math-svid-compat.h>
      21  #include <libm-alias-double.h>
      22  
      23  
      24  #if LIBM_SVID_COMPAT && (SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_29) \
      25  			 || defined NO_LONG_DOUBLE \
      26  			 || defined LONG_DOUBLE_COMPAT)
      27  /* wrapper pow */
      28  double
      29  __pow_compat (double x, double y)
      30  {
      31    double z = __ieee754_pow (x, y);
      32    if (__glibc_unlikely (!isfinite (z)))
      33      {
      34        if (_LIB_VERSION != _IEEE_)
      35  	{
      36  	  if (isfinite (x) && isfinite (y))
      37  	    {
      38  	      if (isnan (z))
      39  		/* pow neg**non-int */
      40  		return __kernel_standard (x, y, 24);
      41  	      else if (x == 0.0 && y < 0.0)
      42  		{
      43  		  if (signbit (x) && signbit (z))
      44  		    /* pow(-0.0,negative) */
      45  		    return __kernel_standard (x, y, 23);
      46  		  else
      47  		    /* pow(+0.0,negative) */
      48  		    return __kernel_standard (x, y, 43);
      49  		}
      50  	      else
      51  		/* pow overflow */
      52  		return __kernel_standard (x, y, 21);
      53  	    }
      54  	}
      55      }
      56    else if (__builtin_expect (z == 0.0, 0)
      57  	   && isfinite (x) && x != 0 && isfinite (y)
      58  	   && _LIB_VERSION != _IEEE_)
      59      /* pow underflow */
      60      return __kernel_standard (x, y, 22);
      61  
      62    return z;
      63  }
      64  # if SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_29)
      65  compat_symbol (libm, __pow_compat, pow, GLIBC_2_0);
      66  # endif
      67  # ifdef NO_LONG_DOUBLE
      68  weak_alias (__pow_compat, powl)
      69  # endif
      70  # ifdef LONG_DOUBLE_COMPAT
      71  /* Work around gas bug "multiple versions for symbol".  */
      72  weak_alias (__pow_compat, __pow_compat_alias)
      73  
      74  LONG_DOUBLE_COMPAT_CHOOSE_libm_powl (
      75    compat_symbol (libm, __pow_compat_alias, powl, FIRST_VERSION_libm_powl), );
      76  # endif
      77  #endif