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Attila Body 2025-06-09 18:06:36 +02:00
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#
# Copyright (c) 2019-2022 Arm Limited.
#
# 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.
#
file(GLOB SRC "./*_s8.c")
target_sources(cmsis-nn PRIVATE ${SRC} arm_softmax_s8_s16.c
arm_softmax_s16.c
arm_nn_softmax_common_s8.c)

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/*
* Copyright (C) 2022 Arm Limited or its affiliates.
*
* 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.
*/
/* ----------------------------------------------------------------------
* Project: CMSIS NN Library
* Title: arm_nn_softmax_common_s8.c
* Description: Softmax with s8 input and output of s8 or s16.
*
* $Date: 17 March 2022
* $Revision: V.1.0.1
*
* Target Processor: Cortex-M processors
* -------------------------------------------------------------------- */
#include "arm_nnsupportfunctions.h"
#define ACCUM_BITS 12
/**
* @ingroup groupSupport
*/
/**
* @addtogroup Softmax
* @{
*/
/*
* Softmax function with s8 input and output of s8 or s16.
*
* Refer header file for details.
*
*/
void arm_nn_softmax_common_s8(const int8_t *input,
const int32_t num_rows,
const int32_t row_size,
const int32_t mult,
const int32_t shift,
const int32_t diff_min,
const bool int16_output,
void *output)
{
const int32_t mask = (1 << shift);
int32_t col = 0;
int32_t row_idx;
for (row_idx = 0; row_idx < num_rows; ++row_idx)
{
// Find the maximum value in order to ensure numerical stability
int8_t max = *input;
for (col = 1; col < row_size; ++col)
{
max = MAX(max, input[col]);
}
int32_t diff = 0;
int32_t sum = 0;
for (col = 0; col < row_size; ++col)
{
diff = input[col] - max;
if (diff >= diff_min)
{
sum += DIV_POW2(EXP_ON_NEG(MUL_SAT(diff * mask, mult)), ACCUM_BITS);
}
}
const int32_t headroom = __CLZ(sum);
const int32_t shifted_scale = ONE_OVER1((sum > 0 ? sum << headroom : 0) - (1 << 31));
int32_t bits_over_unit;
if (int16_output)
{
int16_t *output_s16 = (int16_t *)output + row_idx * row_size;
bits_over_unit = ACCUM_BITS - headroom + 15;
for (col = 0; col < row_size; ++col)
{
diff = input[col] - max;
if (diff >= diff_min)
{
const int32_t res =
DIV_POW2(MUL_SAT(shifted_scale, EXP_ON_NEG(MUL_SAT(diff * mask, mult))), bits_over_unit) +
NN_Q15_MIN;
output_s16[col] = (int16_t)CLAMP(res, (int32_t)NN_Q15_MAX, (int32_t)NN_Q15_MIN);
}
else
{
output_s16[col] = NN_Q15_MIN;
}
}
}
else
{
int8_t *output_s8 = (int8_t *)output + row_idx * row_size;
bits_over_unit = ACCUM_BITS - headroom + 23;
for (col = 0; col < row_size; ++col)
{
diff = input[col] - max;
if (diff >= diff_min)
{
const int32_t res =
DIV_POW2(MUL_SAT(shifted_scale, EXP_ON_NEG(MUL_SAT(diff * mask, mult))), bits_over_unit) +
NN_Q7_MIN;
output_s8[col] = (int8_t)CLAMP(res, (int32_t)NN_Q7_MAX, (int32_t)NN_Q7_MIN);
}
else
{
output_s8[col] = NN_Q7_MIN;
}
}
}
input += row_size;
}
}
/**
* @} end of NNBasicMath group
*/

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/*
* Copyright (C) 2010-2018 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.
*/
/* ----------------------------------------------------------------------
* Project: CMSIS NN Library
* Title: arm_softmax_q15.c
* Description: Q15 softmax function
*
* $Date: 09. October 2020
* $Revision: V.1.0.1
*
* Target Processor: Cortex-M cores
*
* -------------------------------------------------------------------- */
#include "arm_nnfunctions.h"
/**
* @ingroup groupNN
*/
/**
* @addtogroup Softmax
* @{
*/
/**
* @brief Q15 softmax function
* @param[in] vec_in pointer to input vector
* @param[in] dim_vec input vector dimention
* @param[out] p_out pointer to output vector
*
* @details
*
* Here, instead of typical e based softmax, we use
* 2-based softmax, i.e.,:
*
* y_i = 2^(x_i) / sum(2^x_j)
*
* The relative output will be different here.
* But mathematically, the gradient will be the same
* with a log(2) scaling factor.
*
*/
void arm_softmax_q15(const q15_t *vec_in, const uint16_t dim_vec, q15_t *p_out)
{
q31_t sum;
int16_t i;
uint8_t shift;
q31_t base;
base = -1 * 0x100000;
for (i = 0; i < dim_vec; i++)
{
if (vec_in[i] > base)
{
base = vec_in[i];
}
}
/* we ignore really small values
* anyway, they will be 0 after shrinking
* to q15_t
*/
base = base - 16;
sum = 0;
for (i = 0; i < dim_vec; i++)
{
if (vec_in[i] > base)
{
shift = (uint8_t)__USAT(vec_in[i] - base, 5);
sum += 0x1 << shift;
}
}
/* This is effectively (0x1 << 32) / sum */
int64_t div_base = 0x100000000LL;
int output_base = (int32_t)(div_base / sum);
/* Final confidence will be output_base >> ( 17 - (vec_in[i] - base) )
* so 32768 (0x1<<15) -> 100% confidence when sum = 0x1 << 16, output_base = 0x1 << 16
* and vec_in[i]-base = 16
*/
for (i = 0; i < dim_vec; i++)
{
if (vec_in[i] > base)
{
/* Here minimum value of 17+base-vec[i] will be 1 */
shift = (uint8_t)__USAT(17 + base - vec_in[i], 5);
p_out[i] = (q15_t)__SSAT((output_base >> shift), 16);
}
else
{
p_out[i] = 0;
}
}
}
/**
* @} end of Softmax group
*/

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/*
* Copyright (C) 2010-2020 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.
*/
/* ----------------------------------------------------------------------
* Project: CMSIS NN Library
* Title: arm_softmax_q7.c
* Description: Q7 softmax function
*
* $Date: 09. October 2020
* $Revision: V.1.0.2
*
* Target Processor: Cortex-M cores
*
* -------------------------------------------------------------------- */
#include "arm_nnfunctions.h"
/**
* @ingroup groupNN
*/
/**
* @addtogroup Softmax
* @{
*/
/**
* @brief Q7 softmax function
* @param[in] vec_in pointer to input vector
* @param[in] dim_vec input vector dimention
* @param[out] p_out pointer to output vector
*
* @details
*
* Here, instead of typical natural logarithm e based softmax, we use
* 2-based softmax here, i.e.,:
*
* y_i = 2^(x_i) / sum(2^x_j)
*
* The relative output will be different here.
* But mathematically, the gradient will be the same
* with a log(2) scaling factor.
*
*/
void arm_softmax_q7(const q7_t *vec_in, const uint16_t dim_vec, q7_t *p_out)
{
q31_t sum;
int16_t i;
uint8_t shift;
q15_t base;
base = -128;
/* We first search for the maximum */
for (i = 0; i < dim_vec; i++)
{
if (vec_in[i] > base)
{
base = vec_in[i];
}
}
/*
* So the base is set to max-8, meaning
* that we ignore really small values.
* anyway, they will be 0 after shrinking to q7_t.
*/
base = base - (1 << 3);
sum = 0;
for (i = 0; i < dim_vec; i++)
{
shift = (uint8_t)__USAT(vec_in[i] - base, 3);
sum += 0x1 << shift;
}
/* This is effectively (0x1 << 20) / sum */
int output_base = (1 << 20) / sum;
for (i = 0; i < dim_vec; i++)
{
/* Here minimum value of 13+base-vec_in[i] will be 5 */
shift = (uint8_t)__USAT(13 + base - vec_in[i], 5);
p_out[i] = (q7_t)__SSAT((output_base >> shift), 8);
}
}
/**
* @} end of Softmax group
*/

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/*
* Copyright (C) 2022 Arm Limited or its affiliates.
*
* 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.
*/
/* ----------------------------------------------------------------------
* Project: CMSIS NN Library
* Title: arm_softmax_s16.c
* Description: S16 softmax function
*
* $Date: 9 March 2022
* $Revision: V.1.0.0
*
* Target Processor: Cortex-M cores
*
* -------------------------------------------------------------------- */
#include "arm_nnfunctions.h"
#include "arm_nnsupportfunctions.h"
/**
* @addtogroup Softmax
* @{
*/
arm_status arm_softmax_s16(const int16_t *input,
const int32_t num_rows,
const int32_t row_size,
const int32_t mult,
const int32_t shift,
const cmsis_nn_softmax_lut_s16 *softmax_params,
int16_t *output)
{
int32_t col = 0;
int32_t row_idx;
if (softmax_params->exp_lut == NULL || softmax_params->one_by_one_lut == NULL)
{
return ARM_MATH_ARGUMENT_ERROR;
}
for (row_idx = 0; row_idx < num_rows; ++row_idx)
{
// Find the maximum value in order to ensure numerical stability
int16_t max = *input;
for (col = 1; col < row_size; ++col)
{
max = MAX(max, input[col]);
}
int32_t diff = 0;
int32_t sum = 0;
int16_t *cached_exp_results = output;
for (col = 0; col < row_size; ++col)
{
diff = input[col] - max;
const int32_t scaled_diff = arm_nn_requantize(diff, mult, shift);
const int32_t symmetric_scaled_diff = scaled_diff + NN_Q15_MAX;
const int16_t saturated_symmetric_scaled_diff = MIN(MAX(symmetric_scaled_diff, NN_Q15_MIN), NN_Q15_MAX);
// Lookup from exp table and cache result for next step
const int16_t index = (256 + (saturated_symmetric_scaled_diff >> 7));
const int16_t offset = saturated_symmetric_scaled_diff & 0x7f;
const int16_t base = softmax_params->exp_lut[index];
const int16_t slope = softmax_params->exp_lut[index + 1] - softmax_params->exp_lut[index];
const int16_t delta = (slope * offset + 64) >> 7;
const int16_t result = (base + delta);
cached_exp_results[col] = result;
sum += cached_exp_results[col];
}
const int32_t headroom = __CLZ(sum);
// Compute the reciprocal 1/sum
const int32_t shifted_sum = (((sum) << (headroom - 1)) + (1 << 13)) >> 14;
// Since LUT computes 1/(1 + x), compute x = (sum - 1) => -65536
// Since LUT expects a symmetrical input, recenter from [UINT16_MIN, UINT16_MAX] to [INT16_MIN, INT16_MAX] =>
// -32768 ==> So in total -65536 -32768 => -98304
const int16_t symmetric_shifted_sum = shifted_sum - 98304;
// Lookup from one by one table
const int16_t index = (256 + (symmetric_shifted_sum >> 7));
const int16_t offset = symmetric_shifted_sum & 0x7f;
const int16_t base = softmax_params->one_by_one_lut[index];
const int16_t slope = softmax_params->one_by_one_lut[index + 1] - softmax_params->one_by_one_lut[index];
const int16_t delta = (slope * offset + 64) >> 7;
const int16_t one_by_one_result = (base + delta);
for (col = 0; col < row_size; ++col)
{
const int16_t right_shift = 30 - headroom;
int32_t result = (cached_exp_results[col] * one_by_one_result) >> right_shift;
result = (result + 1) >> 1; // Last shift position and insert round
output[col] = (int16_t)result;
}
output += row_size;
input += row_size;
}
return ARM_MATH_SUCCESS;
}
/**
* @} end of Softmax group
*/

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/*
* Copyright (C) 2010-2022 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.
*/
/* ----------------------------------------------------------------------
* Project: CMSIS NN Library
* Title: arm_softmax_s8.c
* Description: S8 softmax function
*
* $Date: 9 March 2022
* $Revision: V.2.1.0
*
* Target Processor: Cortex-M cores
*
* -------------------------------------------------------------------- */
#include "arm_nnfunctions.h"
#include "arm_nnsupportfunctions.h"
#define ACCUM_BITS 12
#ifdef ARM_MATH_MVEI
static int32x4_t arm_exp_on_negative_values_mve_32x4(int32x4_t val)
{
#define SHIFT_START (24)
int32_t shift = SHIFT_START;
int32x4_t mask;
const int32x4_t val_mod_minus_quarter =
vandq_s32(val, vdupq_n_s32((1 << SHIFT_START) - 1)) - vdupq_n_s32(1 << SHIFT_START);
const int32x4_t remainder = vsubq_s32(val_mod_minus_quarter, val);
const int32x4_t x = vaddq_n_s32(val_mod_minus_quarter << 5, 1 << 28);
const int32x4_t x2 = MUL_SAT_MVE(x, x);
const int32x4_t op_1 = DIV_POW2_MVE(MUL_SAT_MVE(x2, x2), 2) + MUL_SAT_MVE(x2, x);
const int32x4_t op_2 = x + DIV_POW2_MVE(MUL_SAT_MVE(op_1, vdupq_n_s32(715827883)) + x2, 1);
int32x4_t result = vdupq_n_s32(1895147668) + MUL_SAT_MVE(vdupq_n_s32(1895147668), op_2);
#define SELECT_IF_NON_ZERO(x) \
{ \
mve_pred16_t p = vcmpneq_n_s32(remainder & vdupq_n_s32(1 << shift++), 0); \
mask = vmvnq_m_s32(vdupq_n_s32(0), vdupq_n_s32(0), p); \
result = SELECT_USING_MASK(mask, MUL_SAT_MVE(result, vdupq_n_s32(x)), result); \
}
SELECT_IF_NON_ZERO(1672461947)
SELECT_IF_NON_ZERO(1302514674)
SELECT_IF_NON_ZERO(790015084)
SELECT_IF_NON_ZERO(290630308)
SELECT_IF_NON_ZERO(39332535)
SELECT_IF_NON_ZERO(720401)
SELECT_IF_NON_ZERO(242)
#undef SELECT_IF_NON_ZERO
mve_pred16_t p = vcmpeqq_n_s32(val, 0);
mask = vmvnq_m_s32(vdupq_n_s32(0), vdupq_n_s32(0), p);
result = SELECT_USING_MASK(mask, vdupq_n_s32(NN_Q31_MAX), result);
return result;
}
#endif
/**
* @ingroup groupNN
*/
/**
* @addtogroup Softmax
* @{
*/
void arm_softmax_s8(const int8_t *input,
const int32_t num_rows,
const int32_t row_size,
const int32_t mult,
const int32_t shift,
const int32_t diff_min,
int8_t *output)
{
#ifdef ARM_MATH_MVEI
#define ACT_MIN ((int8_t)NN_Q7_MIN)
#define ACT_MAX ((int8_t)NN_Q7_MAX)
const int32_t mask = (1 << shift);
for (int i_num_rows = 0; i_num_rows < num_rows; ++i_num_rows)
{
int8_t max = ACT_MIN;
int32_t vec_count = (row_size + 15) / 16;
uint32_t r_count = (uint32_t)row_size;
for (int i = 0; i < vec_count; i++)
{
mve_pred16_t p = vctp8q(r_count);
const int8x16_t ip = vldrbq_z_s8(&input[i * 16], p);
max = vmaxvq_p_s8(max, ip, p);
r_count -= 16;
}
vec_count = row_size / 4;
int32_t idx = 0;
int32_t sum = 0;
while (vec_count)
{
int32x4_t ip = vldrbq_s32(&input[idx * 4]);
ip = vsubq_n_s32(ip, max);
mve_pred16_t p = vcmpgeq_n_s32(ip, diff_min);
if (p != 0)
{
ip = vmulq_n_s32(ip, mask);
int32x4_t res = MUL_SAT_MVE(ip, vdupq_n_s32(mult));
res = arm_exp_on_negative_values_mve_32x4(res);
res = DIV_POW2_MVE(res, ACCUM_BITS);
res = vpselq_s32(res, vdupq_n_s32(0), p);
sum += vaddvq_s32(res);
}
vec_count--;
idx++;
}
const int32_t tail_idx = row_size & ~3;
for (int i = 0; i < (row_size & 3); i++)
{
const int32_t diff = input[tail_idx + i] - max;
if (diff >= diff_min)
{
sum += DIV_POW2(EXP_ON_NEG(MUL_SAT(diff * mask, mult)), ACCUM_BITS);
}
}
const int32_t headroom = __CLZ((uint32_t)sum);
const int32_t bits_over_unit = ACCUM_BITS - headroom + 23;
const int32_t shifted_scale = ONE_OVER1((sum > 0 ? sum << headroom : 0) - (1 << 31));
vec_count = row_size / 4;
idx = 0;
while (vec_count)
{
int32x4_t ip = vldrbq_s32(&input[idx]);
ip = vsubq_n_s32(ip, max);
mve_pred16_t p = vcmpgeq_n_s32(ip, diff_min);
int32x4_t tmp_res;
if (p != 0)
{
ip = vmulq_n_s32(ip, mask);
tmp_res = MUL_SAT_MVE(ip, vdupq_n_s32(mult));
tmp_res = arm_exp_on_negative_values_mve_32x4(tmp_res);
tmp_res = MUL_SAT_MVE(vdupq_n_s32(shifted_scale), tmp_res);
tmp_res = DIV_POW2_MVE(tmp_res, bits_over_unit);
tmp_res += vdupq_n_s32(ACT_MIN);
tmp_res = vmaxq_s32(tmp_res, vdupq_n_s32(ACT_MIN));
tmp_res = vminq_s32(tmp_res, vdupq_n_s32(ACT_MAX));
tmp_res = vpselq_s32(tmp_res, vdupq_n_s32(ACT_MIN), p);
}
else
{
tmp_res = vdupq_n_s32(ACT_MIN);
}
vstrbq_s32(&output[idx], tmp_res);
vec_count--;
idx += 4;
}
for (int i = 0; i < (row_size & 3); i++)
{
int32_t diff = input[tail_idx + i] - max;
if (diff >= diff_min)
{
const int32_t res =
DIV_POW2(MUL_SAT(shifted_scale, EXP_ON_NEG(MUL_SAT(diff * mask, mult))), bits_over_unit) +
NN_Q7_MIN;
output[tail_idx + i] = (int8_t)CLAMP(res, (int32_t)ACT_MAX, (int32_t)ACT_MIN);
}
else
{
output[tail_idx + i] = ACT_MIN;
}
}
input += row_size;
output += row_size;
}
#else
arm_nn_softmax_common_s8(input, num_rows, row_size, mult, shift, diff_min, false, (void *)output);
#endif
}
/**
* @} end of Softmax group
*/

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/*
* Copyright (C) 2022 Arm Limited or its affiliates.
*
* 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.
*/
/* ----------------------------------------------------------------------
* Project: CMSIS NN Library
* Title: arm_softmax_s8_s16.c
* Description: S8 to s16 softmax function
*
* $Date: 7 January 2022
* $Revision: V.1.0.0
*
* Target Processor: Cortex-M cores
*
* -------------------------------------------------------------------- */
#include "arm_nnfunctions.h"
#include "arm_nnsupportfunctions.h"
/**
* @ingroup groupNN
*/
/**
* @addtogroup Softmax
* @{
*/
void arm_softmax_s8_s16(const int8_t *input,
const int32_t num_rows,
const int32_t row_size,
const int32_t mult,
const int32_t shift,
const int32_t diff_min,
int16_t *output)
{
arm_nn_softmax_common_s8(input, num_rows, row_size, mult, shift, diff_min, true, (void *)output);
}
/**
* @} end of Softmax group
*/

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/*
* Copyright (C) 2010-2020 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.
*/
/* ----------------------------------------------------------------------
* Project: CMSIS NN Library
* Title: arm_softmax_u8.c
* Description: U8 softmax function
*
* $Date: 09. October 2020
* $Revision: V.1.0.2
*
* Target Processor: Cortex-M CPUs
*
* -------------------------------------------------------------------- */
#include "arm_nnfunctions.h"
#include "arm_nnsupportfunctions.h"
#define ACCUM_BITS 12
/**
* @ingroup groupNN
*/
/**
* @addtogroup Softmax
* @{
*/
void arm_softmax_u8(const uint8_t *input,
const int32_t num_rows,
const int32_t row_size,
const int32_t mult,
const int32_t shift,
const int32_t diff_min,
uint8_t *output)
{
const int32_t mask = (1 << shift);
int32_t col = 0;
int32_t row_idx;
for (row_idx = 0; row_idx < num_rows; ++row_idx)
{
// Find the maximum value in order to ensure numerical stability
uint8_t max = *input;
for (col = 1; col < row_size; ++col)
{
max = MAX(max, input[col]);
}
int32_t diff = 0;
int32_t sum = 0;
for (col = 0; col < row_size; ++col)
{
diff = input[col] - max;
if (diff >= diff_min)
{
sum += DIV_POW2(EXP_ON_NEG(MUL_SAT(diff * mask, mult)), ACCUM_BITS);
}
}
const int32_t headroom = __CLZ((uint32_t)sum);
const int32_t bits_over_unit = ACCUM_BITS - headroom + 23;
const int32_t shifted_scale = ONE_OVER1((sum << headroom) - (1 << 31));
for (col = 0; col < row_size; ++col)
{
diff = input[col] - max;
if (diff >= diff_min)
{
const int32_t res =
DIV_POW2(MUL_SAT(shifted_scale, EXP_ON_NEG(MUL_SAT(diff * mask, mult))), bits_over_unit);
output[col] = (uint8_t)CLAMP(res, (int32_t)255, (int32_t)0);
}
else
{
output[col] = 0;
}
}
input += row_size;
output += row_size;
}
}
/**
* @} end of Softmax group
*/

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@ -0,0 +1,74 @@
/*
* 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.
*/
/* ----------------------------------------------------------------------
* Project: CMSIS NN Library
* Title: arm_softmax_with_batch_q7.c
* Description: Q7 softmax function
*
* $Date: 09. October 2020
* $Revision: V.1.0.1
*
* Target Processor: Cortex-M and Cortex-A cores
*
* -------------------------------------------------------------------- */
#include "arm_nnfunctions.h"
/**
* @ingroup groupNN
*/
/**
* @addtogroup Softmax
* @{
*/
/**
* @brief Q7 softmax function with batch parameter
* @param[in] vec_in pointer to input vector
* @param[in] nb_batches number of batches
* @param[in] dim_vec input vector dimention
* @param[out] p_out pointer to output vector
*
* @details
*
* Here, instead of typical natural logarithm e based softmax, we use
* 2-based softmax here, i.e.,:
*
* y_i = 2^(x_i) / sum(2^x_j)
*
* The relative output will be different here.
* But mathematically, the gradient will be the same
* with a log(2) scaling factor.
*
*/
void arm_softmax_with_batch_q7(const q7_t *vec_in, const uint16_t nb_batches, const uint16_t dim_vec, q7_t *p_out)
{
for (int i = 0; i < nb_batches; i++)
{
arm_softmax_q7(vec_in, dim_vec, p_out);
vec_in += dim_vec;
p_out += dim_vec;
}
}
/**
* @} end of Softmax group
*/