/* Single-precision math error handling.

   Copyright (C) 2017-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include "math_config.h"

#if WANT_ERRNO

# include <errno.h>

/* NOINLINE reduces code size.  */

NOINLINE static float

with_errnof (float y, int e)

{

  errno = e;

  return y;

}

#else

# define with_errnof(x, e) (x)

#endif

/* NOINLINE prevents fenv semantics breaking optimizations.  */

NOINLINE static float

xflowf (uint32_t sign, float y)

{

  y = (sign ? -y : y) * y;

  return with_errnof (y, ERANGE);

}

attribute_hidden float

__math_uflowf (uint32_t sign)

{

  return xflowf (sign, 0x1p-95f);

}

#if WANT_ERRNO_UFLOW

/* Underflows to zero in some non-nearest rounding mode, setting errno

   is valid even if the result is non-zero, but in the subnormal range.  */

attribute_hidden float

__math_may_uflowf (uint32_t sign)

{

  return xflowf (sign, 0x1.4p-75f);

}

#endif

attribute_hidden float

__math_oflowf (uint32_t sign)

{

  return xflowf (sign, 0x1p97f);

}

attribute_hidden float

__math_divzerof (uint32_t sign)

{

  float y = 0;

  return with_errnof ((sign ? -1 : 1) / y, ERANGE);

}

attribute_hidden float

__math_invalidf (float x)

{

  float y = (x - x) / (x - x);

  return isnan (x) ? y : with_errnof (y, EDOM);

}