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Diffstat (limited to 'support/Rounding.h')
| -rw-r--r-- | support/Rounding.h | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/support/Rounding.h b/support/Rounding.h new file mode 100644 index 0000000000..5691a6680b --- /dev/null +++ b/support/Rounding.h @@ -0,0 +1,206 @@ +/* + * Copyright (c) 2018-2021, 2023 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. + */ +#ifndef ARM_COMPUTE_UTILS_ROUNDING_H +#define ARM_COMPUTE_UTILS_ROUNDING_H + +#include "arm_compute/core/Error.h" +#include "arm_compute/core/utils/misc/Traits.h" + +#include "support/AclRequires.h" +#include "support/ToolchainSupport.h" + +#include <cmath> + +namespace arm_compute +{ +namespace utils +{ +namespace rounding +{ +/** Rounding mode */ +enum class RoundingMode +{ + TO_ZERO, /**< Round towards zero */ + AWAY_FROM_ZERO, /**< Round away from zero */ + HALF_TO_ZERO, /**< Round half towards from zero */ + HALF_AWAY_FROM_ZERO, /**< Round half away from zero */ + HALF_UP, /**< Round half towards positive infinity */ + HALF_DOWN, /**< Round half towards negative infinity */ + HALF_EVEN /**< Round half towards nearest even */ +}; + +/** Round floating-point value with round to zero + * + * @tparam T Parameter type. Should be of floating point type. + * + * @param[in] value floating-point value to be rounded. + * + * @return Floating-point value of rounded @p value. + */ +template <typename T, ARM_COMPUTE_REQUIRES_TA(traits::is_floating_point<T>::value)> +inline T round_to_zero(T value) +{ + T res = std::floor(std::fabs(value)); + return (value < 0.f) ? -res : res; +} + +/** Round floating-point value with round away from zero + * + * @tparam T Parameter type. Should be of floating point type. + * + * @param[in] value floating-point value to be rounded. + * + * @return Floating-point value of rounded @p value. + */ +template <typename T, ARM_COMPUTE_REQUIRES_TA(traits::is_floating_point<T>::value)> +inline T round_away_from_zero(T value) +{ + T res = std::ceil(std::fabs(value)); + return (value < 0.f) ? -res : res; +} + +/** Round floating-point value with half value rounding towards zero. + * + * @tparam T Parameter type. Should be of floating point type. + * + * @param[in] value floating-point value to be rounded. + * + * @return Floating-point value of rounded @p value. + */ +template <typename T, ARM_COMPUTE_REQUIRES_TA(traits::is_floating_point<T>::value)> +inline T round_half_to_zero(T value) +{ + T res = T(std::ceil(std::fabs(value) - 0.5f)); + return (value < 0.f) ? -res : res; +} + +/** Round floating-point value with half value rounding away from zero. + * + * @tparam T Parameter type. Should be of floating point type. + * + * @param[in] value floating-point value to be rounded. + * + * @return Floating-point value of rounded @p value. + */ +template <typename T, ARM_COMPUTE_REQUIRES_TA(traits::is_floating_point<T>::value)> +inline T round_half_away_from_zero(T value) +{ + T res = T(std::floor(std::fabs(value) + 0.5f)); + return (value < 0.f) ? -res : res; +} + +/** Round floating-point value with half value rounding to positive infinity. + * + * @tparam T Parameter type. Should be of floating point type. + * + * @param[in] value floating-point value to be rounded. + * + * @return Floating-point value of rounded @p value. + */ +template <typename T, ARM_COMPUTE_REQUIRES_TA(traits::is_floating_point<T>::value)> +inline T round_half_up(T value) +{ + return std::floor(value + 0.5f); +} + +/** Round floating-point value with half value rounding to negative infinity. + * + * @tparam T Parameter type. Should be of floating point type. + * + * @param[in] value floating-point value to be rounded. + * + * @return Floating-point value of rounded @p value. + */ +template <typename T, ARM_COMPUTE_REQUIRES_TA(traits::is_floating_point<T>::value)> +inline T round_half_down(T value) +{ + return std::ceil(value - 0.5f); +} + +/** Round floating-point value with half value rounding to nearest even. + * + * @tparam T Parameter type. Should be of floating point type. + * + * @param[in] value floating-point value to be rounded. + * @param[in] epsilon precision. + * + * @return Floating-point value of rounded @p value. + */ +template <typename T, ARM_COMPUTE_REQUIRES_TA(traits::is_floating_point<T>::value)> +inline T round_half_even(T value, T epsilon = std::numeric_limits<T>::epsilon()) +{ + T positive_value = std::abs(value); + T ipart = 0; + std::modf(positive_value, &ipart); + // If 'value' is exactly halfway between two integers + if (std::abs(positive_value - (ipart + 0.5f)) < epsilon) + { + // If 'ipart' is even then return 'ipart' + if (std::fmod(ipart, 2.f) < epsilon) + { + return support::cpp11::copysign(ipart, value); + } + // Else return the nearest even integer + return support::cpp11::copysign(std::ceil(ipart + 0.5f), value); + } + // Otherwise use the usual round to closest + return support::cpp11::copysign(support::cpp11::round(positive_value), value); +} + +/** Round floating-point value given a rounding mode + * + * @tparam T Parameter type. Should be of floating point type. + * + * @param[in] value floating-point value to be rounded. + * @param[in] rounding_mode Rounding mode to use. + * + * @return Floating-point value of rounded @p value. + */ +template <typename T, ARM_COMPUTE_REQUIRES_TA(traits::is_floating_point<T>::value)> +inline T round(T value, RoundingMode rounding_mode) +{ + switch (rounding_mode) + { + case RoundingMode::TO_ZERO: + return round_to_zero(value); + case RoundingMode::AWAY_FROM_ZERO: + return round_away_from_zero(value); + case RoundingMode::HALF_TO_ZERO: + return round_half_to_zero(value); + case RoundingMode::HALF_AWAY_FROM_ZERO: + return round_half_away_from_zero(value); + case RoundingMode::HALF_UP: + return round_half_up(value); + case RoundingMode::HALF_DOWN: + return round_half_down(value); + case RoundingMode::HALF_EVEN: + return round_half_even(value); + default: + ARM_COMPUTE_ERROR("Unsupported rounding mode!"); + } +} +} // namespace rounding +} // namespace utils +} // namespace arm_compute +#endif /*ARM_COMPUTE_UTILS_ROUNDING_H */ |