178 lines
4.4 KiB
C
178 lines
4.4 KiB
C
|
|
/* ----------------------------------------------------------------------
|
|
* Project: CMSIS DSP Library
|
|
* Title: arm_jensenshannon_distance_f16.c
|
|
* Description: Jensen-Shannon distance between two vectors
|
|
*
|
|
* $Date: 23 April 2021
|
|
* $Revision: V1.9.0
|
|
*
|
|
* Target Processor: Cortex-M and Cortex-A cores
|
|
* -------------------------------------------------------------------- */
|
|
/*
|
|
* Copyright (C) 2010-2021 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 "dsp/distance_functions_f16.h"
|
|
|
|
#if defined(ARM_FLOAT16_SUPPORTED)
|
|
|
|
#include <limits.h>
|
|
#include <math.h>
|
|
|
|
/**
|
|
@ingroup FloatDist
|
|
*/
|
|
|
|
/**
|
|
@defgroup JensenShannon Jensen-Shannon distance
|
|
|
|
Jensen-Shannon distance
|
|
*/
|
|
|
|
|
|
/**
|
|
@addtogroup JensenShannon
|
|
@{
|
|
*/
|
|
|
|
#if !defined(ARM_MATH_MVE_FLOAT16) || defined(ARM_MATH_AUTOVECTORIZE)
|
|
/// @private
|
|
__STATIC_INLINE float16_t rel_entr(float16_t x, float16_t y)
|
|
{
|
|
return ((_Float16)x * (_Float16)logf((float32_t)((_Float16)x / (_Float16)y)));
|
|
}
|
|
#endif
|
|
|
|
|
|
#if defined(ARM_MATH_MVE_FLOAT16) && !defined(ARM_MATH_AUTOVECTORIZE)
|
|
|
|
#include "arm_helium_utils.h"
|
|
#include "arm_vec_math_f16.h"
|
|
|
|
float16_t arm_jensenshannon_distance_f16(const float16_t *pA,const float16_t *pB, uint32_t blockSize)
|
|
{
|
|
uint32_t blkCnt;
|
|
float16_t tmp;
|
|
f16x8_t a, b, t, tmpV, accumV;
|
|
|
|
accumV = vdupq_n_f16(0.0f);
|
|
|
|
blkCnt = blockSize >> 3;
|
|
while (blkCnt > 0U) {
|
|
a = vld1q(pA);
|
|
b = vld1q(pB);
|
|
|
|
t = vaddq(a, b);
|
|
t = vmulq(t, 0.5f);
|
|
|
|
tmpV = vmulq(a, vrecip_medprec_f16(t));
|
|
tmpV = vlogq_f16(tmpV);
|
|
accumV = vfmaq(accumV, a, tmpV);
|
|
|
|
tmpV = vmulq_f16(b, vrecip_medprec_f16(t));
|
|
tmpV = vlogq_f16(tmpV);
|
|
accumV = vfmaq(accumV, b, tmpV);
|
|
|
|
pA += 8;
|
|
pB += 8;
|
|
blkCnt--;
|
|
}
|
|
|
|
/*
|
|
* tail
|
|
* (will be merged thru tail predication)
|
|
*/
|
|
blkCnt = blockSize & 7;
|
|
if (blkCnt > 0U) {
|
|
mve_pred16_t p0 = vctp16q(blkCnt);
|
|
|
|
a = vldrhq_z_f16(pA, p0);
|
|
b = vldrhq_z_f16(pB, p0);
|
|
|
|
t = vaddq(a, b);
|
|
t = vmulq(t, 0.5f);
|
|
|
|
tmpV = vmulq_f16(a, vrecip_medprec_f16(t));
|
|
tmpV = vlogq_f16(tmpV);
|
|
accumV = vfmaq_m_f16(accumV, a, tmpV, p0);
|
|
|
|
tmpV = vmulq_f16(b, vrecip_medprec_f16(t));
|
|
tmpV = vlogq_f16(tmpV);
|
|
accumV = vfmaq_m_f16(accumV, b, tmpV, p0);
|
|
|
|
}
|
|
|
|
arm_sqrt_f16((_Float16)vecAddAcrossF16Mve(accumV) / 2.0f16, &tmp);
|
|
return (tmp);
|
|
}
|
|
|
|
#else
|
|
|
|
|
|
/**
|
|
* @brief Jensen-Shannon distance between two vectors
|
|
*
|
|
* This function is assuming that elements of second vector are > 0
|
|
* and 0 only when the corresponding element of first vector is 0.
|
|
* Otherwise the result of the computation does not make sense
|
|
* and for speed reasons, the cases returning NaN or Infinity are not
|
|
* managed.
|
|
*
|
|
* When the function is computing x log (x / y) with x == 0 and y == 0,
|
|
* it will compute the right result (0) but a division by zero will occur
|
|
* and should be ignored in client code.
|
|
*
|
|
* @param[in] pA First vector
|
|
* @param[in] pB Second vector
|
|
* @param[in] blockSize vector length
|
|
* @return distance
|
|
*
|
|
*/
|
|
|
|
|
|
float16_t arm_jensenshannon_distance_f16(const float16_t *pA,const float16_t *pB, uint32_t blockSize)
|
|
{
|
|
_Float16 left, right,sum, tmp;
|
|
float16_t result;
|
|
uint32_t i;
|
|
|
|
left = 0.0f16;
|
|
right = 0.0f16;
|
|
for(i=0; i < blockSize; i++)
|
|
{
|
|
tmp = ((_Float16)pA[i] + (_Float16)pB[i]) / 2.0f16;
|
|
left += (_Float16)rel_entr(pA[i], tmp);
|
|
right += (_Float16)rel_entr(pB[i], tmp);
|
|
}
|
|
|
|
|
|
sum = left + right;
|
|
arm_sqrt_f16((_Float16)sum/2.0f16, &result);
|
|
return(result);
|
|
|
|
}
|
|
|
|
#endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */
|
|
|
|
/**
|
|
* @} end of JensenShannon group
|
|
*/
|
|
|
|
#endif /* #if defined(ARM_FLOAT16_SUPPORTED) */
|
|
|