/****************************************************************************
 * libs/libc/machine/arm/armv7-m/math/arch_sqrtf.c
 *
 * This file is a part of NuttX:
 *
 *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
 *   Author: David S. Alessio <david.s.alessio@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>
#include <math.h>

/****************************************************************************
 * Public Functions
 ****************************************************************************/

#if (__ARM_ARCH >= 7) && (__ARM_FP >= 4)

float sqrtf(float x)
{
  float result;
  asm volatile ( "vsqrt.f32\t%0, %1" : "=t" (result) : "t" (x) );
  return result;
}

#else
#  warning sqrtf() not built
#endif