46 lines
1.7 KiB
C
46 lines
1.7 KiB
C
/****************************************************************************
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* libs/libc/machine/arm/armv7-m/math/arch_sqrtf.c
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*
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* This file is a part of NuttX:
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*
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* Copyright (C) 2019 Gregory Nutt. All rights reserved.
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* Author: David S. Alessio <david.s.alessio@gmail.com>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <math.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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#if (__ARM_ARCH >= 7) && (__ARM_FP >= 4)
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float sqrtf(float x)
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{
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float result;
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asm volatile ( "vsqrt.f32\t%0, %1" : "=t" (result) : "t" (x) );
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return result;
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}
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#else
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# warning sqrtf() not built
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#endif
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