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 <errno.h>
      19  #include <math.h>
      20  #include <math_private.h>
      21  #include <math-svid-compat.h>
      22  
      23  
      24  #if LIBM_SVID_COMPAT
      25  static float
      26  __attribute__ ((noinline))
      27  sysv_scalbf (float x, float fn)
      28  {
      29    float z = __ieee754_scalbf (x, fn);
      30  
      31    if (__glibc_unlikely (isinf (z)))
      32      {
      33        if (isfinite (x))
      34  	return __kernel_standard_f (x, fn, 132); /* scalb overflow */
      35        else
      36  	__set_errno (ERANGE);
      37      }
      38    else if (__builtin_expect (z == 0.0f, 0) && z != x)
      39      return __kernel_standard_f (x, fn, 133); /* scalb underflow */
      40  
      41    return z;
      42  }
      43  
      44  
      45  /* Wrapper scalbf */
      46  float
      47  __scalbf (float x, float fn)
      48  {
      49    if (__glibc_unlikely (_LIB_VERSION == _SVID_))
      50      return sysv_scalbf (x, fn);
      51    else
      52      {
      53        float z = __ieee754_scalbf (x, fn);
      54  
      55        if (__glibc_unlikely (!isfinite (z) || z == 0.0f))
      56  	{
      57  	  if (isnan (z))
      58  	    {
      59  	      if (!isnan (x) && !isnan (fn))
      60  		__set_errno (EDOM);
      61  	    }
      62  	  else if (isinf (z))
      63  	    {
      64  	      if (!isinf (x) && !isinf (fn))
      65  		__set_errno (ERANGE);
      66  	    }
      67  	  else
      68  	    {
      69  	      /* z == 0.  */
      70  	      if (x != 0.0f && !isinf (fn))
      71  		__set_errno (ERANGE);
      72  	    }
      73  	}
      74        return z;
      75      }
      76  }
      77  weak_alias (__scalbf, scalbf)
      78  #endif