1  /* Single-precision math error handling.
       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  #include "math_config.h"
      20  
      21  #if WANT_ERRNO
      22  # include <errno.h>
      23  /* NOINLINE reduces code size.  */
      24  NOINLINE static float
      25  with_errnof (float y, int e)
      26  {
      27    errno = e;
      28    return y;
      29  }
      30  #else
      31  # define with_errnof(x, e) (x)
      32  #endif
      33  
      34  attribute_hidden float
      35  __math_edomf (float y)
      36  {
      37    return with_errnof (y, EDOM);
      38  }
      39  
      40  /* NOINLINE prevents fenv semantics breaking optimizations.  */
      41  NOINLINE static float
      42  xflowf (uint32_t sign, float y)
      43  {
      44    y = (sign ? -y : y) * y;
      45    return with_errnof (y, ERANGE);
      46  }
      47  
      48  attribute_hidden float
      49  __math_uflowf (uint32_t sign)
      50  {
      51    return xflowf (sign, 0x1p-95f);
      52  }
      53  
      54  #if WANT_ERRNO_UFLOW
      55  /* Underflows to zero in some non-nearest rounding mode, setting errno
      56     is valid even if the result is non-zero, but in the subnormal range.  */
      57  attribute_hidden float
      58  __math_may_uflowf (uint32_t sign)
      59  {
      60    return xflowf (sign, 0x1.4p-75f);
      61  }
      62  #endif
      63  
      64  attribute_hidden float
      65  __math_oflowf (uint32_t sign)
      66  {
      67    return xflowf (sign, 0x1p97f);
      68  }
      69  
      70  attribute_hidden float
      71  __math_divzerof (uint32_t sign)
      72  {
      73    float y = 0;
      74    return with_errnof ((sign ? -1 : 1) / y, ERANGE);
      75  }
      76  
      77  attribute_hidden float
      78  __math_invalidf (float x)
      79  {
      80    float y = (x - x) / (x - x);
      81    return isnan (x) ? y : with_errnof (y, EDOM);
      82  }