incubator-nuttx/libc/machine/arm/armv8/arch_nearbyint.c

58 lines
2.4 KiB
C

/****************************************************************************
* libc/machine/arm/armv8/arch_nearbyint.c
*
* Copyright (C) 2017 Gregory Nutt. All rights reserved.
*
* Adapted for NuttX from BSD licensed code provided by ARM:
*
* Copyright (c) 2011, 2012 ARM Ltd. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the company may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <math.h>
/****************************************************************************
* Public Functions
****************************************************************************/
#if __ARM_ARCH >= 8 && (__ARM_FP & 0x8) && !defined (__SOFTFP__)
double nearbyint(double x)
{
double result;
asm volatile ("vrintr.f64\t%P0, %P1" : "=w" (result) : "w" (x));
return result;
}
#else
# warning nearbyint() not built
#endif