1  /* Wrapper to set errno for scalb.
       2     Copyright (C) 2020-2023 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     <http://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 <math.h>
      26  #include <math_private.h>
      27  
      28  /* Wrapper scalb */
      29  FLOAT M_DECL_FUNC (__scalb) (FLOAT x, FLOAT fn)
      30  {
      31    FLOAT z = M_SUF (__ieee754_scalb) (x, fn);
      32  
      33    if (__glibc_unlikely (!isfinite (z) || z == M_LIT (0.0)))
      34      {
      35        if (isnan (z))
      36  	{
      37  	  if (!isnan (x) && !isnan (fn))
      38  	    __set_errno (EDOM);
      39  	}
      40        else if (isinf (z))
      41  	{
      42  	  if (!isinf (x) && !isinf (fn))
      43  	    __set_errno (ERANGE);
      44  	}
      45        else
      46  	{
      47  	  /* z == 0.  */
      48  	  if (x != M_LIT (0.0) && !isinf (fn))
      49  	    __set_errno (ERANGE);
      50  	}
      51      }
      52    return z;
      53  }
      54  
      55  declare_mgen_alias (__scalb, scalb);
      56  
      57  #endif /* __USE_WRAPPER_TEMPLATE.  */