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CMSIS-DSP/Source/DistanceFunctions/arm_euclidean_distance_f32.c

107 lines
2.4 KiB
C

/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_euclidean_distance_f32.c
* Description: Euclidean distance between two vectors
*
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "arm_math.h"
#include <limits.h>
#include <math.h>
/**
@addtogroup FloatDist
@{
*/
/**
* @brief Euclidean distance between two vectors
* @param[in] pA First vector
* @param[in] pB Second vector
* @param[in] blockSize vector length
* @return distance
*
*/
#if defined(ARM_MATH_NEON)
#include "NEMath.h"
float32_t arm_euclidean_distance_f32(const float32_t *pA,const float32_t *pB, uint32_t blockSize)
{
float32_t accum=0.0,tmp;
uint32_t i,blkCnt;
float32x4_t a,b,accumV;
float32x2_t accumV2;
accumV = vdupq_n_f32(0.0);
blkCnt = blockSize >> 2;
while(blkCnt > 0)
{
a = vld1q_f32(pA);
b = vld1q_f32(pB);
a = vsubq_f32(a,b);
accumV = vmlaq_f32(accumV,a,a);
pA += 4;
pB += 4;
blkCnt --;
}
accumV2 = vpadd_f32(vget_low_f32(accumV),vget_high_f32(accumV));
accum = accumV2[0] + accumV2[1];
blkCnt = blockSize & 3;
while(blkCnt > 0)
{
tmp = *pA++ - *pB++;
accum += SQ(tmp);
blkCnt --;
}
arm_sqrt_f32(accum,&tmp);
return(tmp);
}
#else
float32_t arm_euclidean_distance_f32(const float32_t *pA,const float32_t *pB, uint32_t blockSize)
{
float32_t accum=0.0,tmp;
while(blockSize > 0)
{
tmp = *pA++ - *pB++;
accum += SQ(tmp);
blockSize --;
}
arm_sqrt_f32(accum,&tmp);
return(tmp);
}
#endif
/**
* @} end of FloatDist group
*/