| /* |
| * Copyright (c) 2017 ARM Limited. |
| * |
| * SPDX-License-Identifier: MIT |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to |
| * deal in the Software without restriction, including without limitation the |
| * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or |
| * sell copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in all |
| * copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. |
| */ |
| #include "arm_compute/core/utils/quantization/AsymmHelpers.h" |
| |
| #include <cmath> |
| #include <limits> |
| #include <numeric> |
| |
| using namespace arm_compute::quantization; |
| |
| constexpr int64_t fixed_point_one_Q0 = (1ll << 31); |
| |
| arm_compute::Status arm_compute::quantization::calculate_quantized_multiplier_less_than_one(double multiplier, |
| int *quant_multiplier, |
| int *right_shift) |
| { |
| ARM_COMPUTE_RETURN_ERROR_ON(quant_multiplier == nullptr); |
| ARM_COMPUTE_RETURN_ERROR_ON(right_shift == nullptr); |
| ARM_COMPUTE_RETURN_ERROR_ON(multiplier < 0); |
| ARM_COMPUTE_RETURN_ERROR_ON(multiplier >= 1); |
| if(multiplier == 0) |
| { |
| *quant_multiplier = 0; |
| *right_shift = 0; |
| return arm_compute::Status{}; |
| } |
| const double q = std::frexp(multiplier, right_shift); |
| *right_shift *= -1; |
| auto q_fixed = static_cast<int64_t>(round(q * fixed_point_one_Q0)); |
| ARM_COMPUTE_RETURN_ERROR_ON(q_fixed > fixed_point_one_Q0); |
| if(q_fixed == fixed_point_one_Q0) |
| { |
| q_fixed /= 2; |
| --*right_shift; |
| } |
| ARM_COMPUTE_RETURN_ERROR_ON(*right_shift < 0); |
| ARM_COMPUTE_RETURN_ERROR_ON(q_fixed > std::numeric_limits<int32_t>::max()); |
| *quant_multiplier = static_cast<int32_t>(q_fixed); |
| |
| return arm_compute::Status{}; |
| } |
| |
| arm_compute::Status arm_compute::quantization::calculate_quantized_multiplier_greater_than_one(double multiplier, |
| int *quantized_multiplier, |
| int *left_shift) |
| { |
| ARM_COMPUTE_RETURN_ERROR_ON(quantized_multiplier == nullptr); |
| ARM_COMPUTE_RETURN_ERROR_ON(left_shift == nullptr); |
| ARM_COMPUTE_RETURN_ERROR_ON(multiplier < 1.f); |
| const double q = std::frexp(multiplier, left_shift); |
| auto q_fixed = static_cast<int64_t>(round(q * fixed_point_one_Q0)); |
| ARM_COMPUTE_RETURN_ERROR_ON(q_fixed > fixed_point_one_Q0); |
| if(q_fixed == fixed_point_one_Q0) |
| { |
| q_fixed /= 2; |
| ++*left_shift; |
| } |
| ARM_COMPUTE_RETURN_ERROR_ON(*left_shift < 0); |
| ARM_COMPUTE_RETURN_ERROR_ON(q_fixed > std::numeric_limits<int32_t>::max()); |
| *quantized_multiplier = static_cast<int32_t>(q_fixed); |
| |
| return arm_compute::Status{}; |
| } |