File size: 4,449 Bytes
25ade36 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 | #include "edge-impulse-sdk/dsp/config.hpp"
#if EIDSP_LOAD_CMSIS_DSP_SOURCES
/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_logsumexp_f16.c
* Description: LogSumExp
*
* $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 "edge-impulse-sdk/CMSIS/DSP/Include/dsp/statistics_functions_f16.h"
#if defined(ARM_FLOAT16_SUPPORTED)
#include <limits.h>
#include <math.h>
/**
* @addtogroup LogSumExp
* @{
*/
/**
* @brief Computation of the LogSumExp
*
* In probabilistic computations, the dynamic of the probability values can be very
* wide because they come from gaussian functions.
* To avoid underflow and overflow issues, the values are represented by their log.
* In this representation, multiplying the original exp values is easy : their logs are added.
* But adding the original exp values is requiring some special handling and it is the
* goal of the LogSumExp function.
*
* If the values are x1...xn, the function is computing:
*
* ln(exp(x1) + ... + exp(xn)) and the computation is done in such a way that
* rounding issues are minimised.
*
* The max xm of the values is extracted and the function is computing:
* xm + ln(exp(x1 - xm) + ... + exp(xn - xm))
*
* @param[in] *in Pointer to an array of input values.
* @param[in] blockSize Number of samples in the input array.
* @return LogSumExp
*
*/
#if defined(ARM_MATH_MVE_FLOAT16) && !defined(ARM_MATH_AUTOVECTORIZE)
#include "edge-impulse-sdk/CMSIS/DSP/Include/arm_helium_utils.h"
#include "edge-impulse-sdk/CMSIS/DSP/Include/arm_vec_math_f16.h"
float16_t arm_logsumexp_f16(const float16_t *in, uint32_t blockSize)
{
float16_t maxVal;
const float16_t *pIn;
int32_t blkCnt;
_Float16 accum=0.0f16;
_Float16 tmp;
arm_max_no_idx_f16((float16_t *) in, blockSize, &maxVal);
blkCnt = blockSize;
pIn = in;
f16x8_t vSum = vdupq_n_f16(0.0f16);
blkCnt = blockSize >> 3;
while(blkCnt > 0)
{
f16x8_t vecIn = vld1q(pIn);
f16x8_t vecExp;
vecExp = vexpq_f16(vsubq_n_f16(vecIn, maxVal));
vSum = vaddq_f16(vSum, vecExp);
/*
* Decrement the blockSize loop counter
* Advance vector source and destination pointers
*/
pIn += 8;
blkCnt --;
}
/* sum + log */
accum = vecAddAcrossF16Mve(vSum);
blkCnt = blockSize & 0x7;
while(blkCnt > 0)
{
tmp = *pIn++;
accum += (_Float16)expf((float32_t)((_Float16)tmp - (_Float16)maxVal));
blkCnt--;
}
accum = (_Float16)maxVal + (_Float16)logf((float32_t)accum);
return (accum);
}
#else
float16_t arm_logsumexp_f16(const float16_t *in, uint32_t blockSize)
{
_Float16 maxVal;
_Float16 tmp;
const float16_t *pIn;
uint32_t blkCnt;
_Float16 accum;
pIn = in;
blkCnt = blockSize;
maxVal = *pIn++;
blkCnt--;
while(blkCnt > 0)
{
tmp = *pIn++;
if (tmp > maxVal)
{
maxVal = tmp;
}
blkCnt--;
}
blkCnt = blockSize;
pIn = in;
accum = 0;
while(blkCnt > 0)
{
tmp = *pIn++;
accum += (_Float16)expf((float32_t)((_Float16)tmp - (_Float16)maxVal));
blkCnt--;
}
accum = (_Float16)maxVal + (_Float16)logf((float32_t)accum);
return(accum);
}
#endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */
/**
* @} end of LogSumExp group
*/
#endif /* #if defined(ARM_FLOAT16_SUPPORTED) */
#endif // EIDSP_LOAD_CMSIS_DSP_SOURCES
|