/* Copyright (C) 1997-2018 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.h>

#include <math_private.h>

#include "mathimpl.h"

#ifndef SUFF

#define SUFF

#endif

#ifndef float_type

#define float_type double

#endif

#define CONCATX(a,b) __CONCAT(a,b)

#define s(name) CONCATX(name,SUFF)

#define m81(func) __m81_u(s(func))

float_type

s(__ieee754_pow) (float_type x, float_type y)

{

  float_type z;

  float_type ax;

  unsigned long x_cond, y_cond;

  y_cond = __m81_test (y);

  if (y_cond & __M81_COND_ZERO)

    return 1.0;

  if (y_cond & __M81_COND_NAN)

    return x == 1.0 ? x : x + y;

  x_cond = __m81_test (x);

  if (x_cond & __M81_COND_NAN)

    return x + y;

  if (y_cond & __M81_COND_INF)

    {

      ax = s(fabs) (x);

      if (ax == 1.0)

	return ax;

      if (ax > 1.0)

	return y_cond & __M81_COND_NEG ? 0 : y;

      else

	return y_cond & __M81_COND_NEG ? -y : 0;

    }

  if (s(fabs) (y) == 1.0)

    return y_cond & __M81_COND_NEG ? 1 / x : x;

  if (y == 2)

    return x * x;

  if (y == 0.5 && !(x_cond & __M81_COND_NEG))

    return m81(sqrt) (x);

  if (x == 10.0)

    {

      __asm ("ftentox%.x %1, %0" : "=f" (z) : "f" (y));

      return z;

    }

  if (x == 2.0)

    {

      __asm ("ftwotox%.x %1, %0" : "=f" (z) : "f" (y));

      return z;

    }

  ax = s(fabs) (x);

  if (x_cond & (__M81_COND_INF | __M81_COND_ZERO) || ax == 1.0)

    {

      z = ax;

      if (y_cond & __M81_COND_NEG)

	z = 1 / z;

      if (x_cond & __M81_COND_NEG)

	{

	  if (y != m81(__rint) (y))

	    {

	      if (x == -1)

		z = (z - z) / (z - z);

	    }

	  else

	    goto maybe_negate;

	}

      return z;

    }

  if (x_cond & __M81_COND_NEG)

    {

      if (y == m81(__rint) (y))

	{

	  z = m81(__ieee754_exp) (y * m81(__ieee754_log) (-x));

	maybe_negate:

	  /* We always use the long double format, since y is already in

	     this format and rounding won't change the result.  */

	  {

	    int32_t exponent;

	    uint32_t i0, i1;

	    GET_LDOUBLE_WORDS (exponent, i0, i1, y);

	    exponent = (exponent & 0x7fff) - 0x3fff;

	    if (exponent <= 31

		? i0 & (1 << (31 - exponent))

		: (exponent <= 63

		   && i1 & (1 << (63 - exponent))))

	      z = -z;

	  }

	}

      else

	z = (y - y) / (y - y);

    }

  else

    z = m81(__ieee754_exp) (y * m81(__ieee754_log) (x));

  return z;

}

strong_alias (s(__ieee754_pow), CONCATX (s(__pow), _finite))