incubator-nuttx/libs/libc/machine/arm/armv7-m/arch_fabsf.c

46 lines
1.7 KiB
C

/****************************************************************************
* libs/libc/machine/arm/armv7-m/math/arch_fabsf.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 fabsf(float x)
{
float result;
asm volatile ( "vabs.f32\t%0, %1" : "=t" (result) : "t" (x) );
return result;
}
#else
# warning fabsf() not built
#endif