1  /* Wrapper to set errno for pow.
       2     Copyright (C) 2017-2023 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  /* Only build wrappers from the templates for the types that define the macro
      20     below.  This macro is set in math-type-macros-<type>.h in sysdeps/generic
      21     for each floating-point type.  */
      22  #if __USE_WRAPPER_TEMPLATE
      23  
      24  # include <errno.h>
      25  # include <fenv.h>
      26  # include <math.h>
      27  # include <math_private.h>
      28  
      29  FLOAT
      30  M_DECL_FUNC (__pow) (FLOAT x, FLOAT y)
      31  {
      32    FLOAT z = M_SUF (__ieee754_pow) (x, y);
      33    if (__glibc_unlikely (!isfinite (z)))
      34      {
      35        if (isfinite (x) && isfinite (y))
      36  	{
      37  	  if (isnan (z))
      38  	    /* Domain error: pow(x<0,y=non-integer).  */
      39  	    __set_errno (EDOM);
      40  	  else
      41  	    /* Pole error: pow(x=0,y<0).  Or overflow.  */
      42  	    __set_errno (ERANGE);
      43  	}
      44      }
      45    else if (__glibc_unlikely (z == 0) && isfinite (x) && x != 0 && isfinite (y))
      46      /* Underflow.  */
      47      __set_errno (ERANGE);
      48    return z;
      49  }
      50  declare_mgen_alias (__pow, pow)
      51  
      52  #endif /* __USE_WRAPPER_TEMPLATE.  */