src/core/NEON/NEMath.h

/*
 * Copyright (c) 2016-2021 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_NEMATH_H
#define ARM_COMPUTE_NEMATH_H

#include <arm_neon.h>
#include <array>

namespace arm_compute
{
/** Calculate floor of a vector.
 *
 * @param[in] val Input vector value in F32 format.
 *
 * @return The calculated floor vector.
 */
float32x4_t vfloorq_f32(float32x4_t val);

/** Calculate round value of a vector to nearest with ties to even.
 *
 * @param[in] val Input vector value in F32 format.
 *
 * @return The calculated round vector.
 */
float32x4_t vroundq_rte_f32(float32x4_t val);

/** Calculate inverse square root.
 *
 * @param[in] x Input value.
 *
 * @return The calculated inverse square root.
 */
float32x2_t vinvsqrt_f32(float32x2_t x);

/** Calculate inverse square root.
 *
 * @param[in] x Input value.
 *
 * @return The calculated inverse square root.
 */
float32x4_t vinvsqrtq_f32(float32x4_t x);

/** Calculate reciprocal.
 *
 * @param[in] x Input value.
 *
 * @return The calculated reciprocal.
 */
float32x2_t vinv_f32(float32x2_t x);

/** Calculate reciprocal.
 *
 * @param[in] x Input value.
 *
 * @return The calculated reciprocal.
 */
float32x4_t vinvq_f32(float32x4_t x);

/** Perform a 7th degree polynomial approximation using Estrin's method.
 *
 * @param[in] x      Input vector value in F32 format.
 * @param[in] coeffs Polynomial coefficients table.
 *
 * @return The calculated approximation.
 */
float32x4_t vtaylor_polyq_f32(float32x4_t x, const std::array<float32x4_t, 8> &coeffs);

/** Calculate exponential
 *
 * @param[in] x Input vector value in F32 format.
 *
 * @return The calculated exponent.
 */
float32x4_t vexpq_f32(float32x4_t x);

/** Calculate logarithm
 *
 * @param[in] x Input vector value in F32 format.
 *
 * @return The calculated logarithm.
 */
float32x4_t vlogq_f32(float32x4_t x);

/** Calculate hyperbolic tangent.
 *
 * tanh(x) = (e^2x - 1)/(e^2x + 1)
 *
 * @note We clamp x to [-5,5] to avoid overflowing issues.
 *
 * @param[in] val Input vector value in F32 format.
 *
 * @return The calculated Hyperbolic Tangent.
 */
float32x4_t vtanhq_f32(float32x4_t val);

/** Calculate n power of a number.
 *
 * pow(x,n) = e^(n*log(x))
 *
 * @param[in] val Input vector value in F32 format.
 * @param[in] n   Powers to raise the input to.
 *
 * @return The calculated power.
 */
float32x4_t vpowq_f32(float32x4_t val, float32x4_t n);

/** Round to the nearest division by a power-of-two using exponent
 *
 * @note This function calculates the following expression: (x + 2^n -1 ) / 2^n where n = exponent
 *
 * @param[in] x        Vector of 4 elements
 * @param[in] exponent Vector of 4 elements with integer value used to round to nearest division by a power-of-two
 *
 * @return the nearest division by a power-of-two using exponent
 */
int32x4_t rounding_divide_by_pow2(int32x4_t x, int32x4_t exponent);

/** Round to the nearest division by a power-of-two using exponent
 *
 * @note This function calculates the following expression: (x + 2^n -1 ) / 2^n where n = exponent
 *
 * @param[in] x        Vector of 4 elements
 * @param[in] exponent Integer value used to round to nearest division by a power-of-two
 *
 * @return the nearest division by a power-of-two using exponent
 */
int32x4_t rounding_divide_by_pow2(int32x4_t x, int exponent);

/** Round to the nearest division by a power-of-two using exponent
 *
 * @note This function calculates the following expression: (x + 2^n -1 ) / 2^n where n = exponent
 *
 * @param[in] x        Element to divide.
 * @param[in] exponent Integer value used to round to nearest division by a power-of-two
 *
 * @return the nearest division by a power-of-two using exponent
 */
int32_t rounding_divide_by_pow2(int32_t x, int exponent);

/** Converts from uint8x16 to float32x4x4_t
 *
 * @param[in] in Vector of uint8 to be converted
 *
 * @return Converted vector of float
 */
float32x4x4_t convert_uint8x16_to_float32x4x4(const uint8x16_t &in);

/** Converts from int8x16 to float32x4x4_t
 *
 * @param[in] in Vector of int8 to be converted
 *
 * @return Converted vector of float
 */
float32x4x4_t convert_int8x16_to_float32x4x4(const int8x16_t &in);

/** Converts to float32x4x4_t from the specified templated 16 elements vectors
 *
 * @param[in] in Vector of float to be converted
 *
 * @return Converted vector of float
 */
template <typename T>
float32x4x4_t convert_to_float32x4x4(const T &in);

/** Converts from two float32x4x3_t to just one uint8x8x3_t
 *
 * @param[in]  in1 First input vector of float to be converted
 * @param[in]  in2 Second input vector of float to be converted
 * @param[out] out Converted output vector uint8 to store the result
 */
void convert_float32x4x3_to_uint8x8x3(const float32x4x3_t &in1, const float32x4x3_t &in2, uint8x8x3_t &out);

/** Converts from two float32x4x4_t to just one uint8x16_t
 *
 * @param[in]  in  Vector of float to be converted
 * @param[out] out Converted vector of uint8 to store the result
 */
void convert_float32x4x4_to_uint8x16(const float32x4x4_t &in, uint8x16_t &out);

/** Converts from float32x4x4_t to just one int8x16_t
 *
 * @param[in]  in  Vector of float to be converted
 * @param[out] out Converted vector of uint8 to store the result
 */
void convert_float32x4x4_to_int8x16(const float32x4x4_t &in, int8x16_t &out);

/** Converts from float vector to integer vector
 *
 * @param[in] in Float vector to converted
 *
 * @return The converted integer vector
 */
template <typename float_vec_type, typename int_vec_type>
int_vec_type convert_float_to_int(const float_vec_type &in);

/** Converts from integer vector to float vector
 *
 * @param[in] in Integer vector to converted
 *
 * @return The converted float vector
 */
template <typename float_vec_type, typename int_vec_type>
float_vec_type convert_int_to_float(const int_vec_type &in);

/** Calculate sine.
 *
 * @param[in] val Input vector value in radians, F32 format.
 *
 * @return The calculated sine.
 */
float32x4_t vsinq_f32(float32x4_t val);

/** Calculate sine.
 *
 * @param[in] val Input vector value in radians, F32 format.
 *
 * @return The calculated sine.
 */
float32x2_t vsin_f32(float32x2_t val);

/** Reduce a vector to be a scalar by accumulating all lanes in the vector
 *
 * @param[in] v Vector to be reduced.
 *
 * @return the wrapped-around number.
 */
float vreduce(const float32x4_t &v);

#ifdef __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
/** Calculate hyperbolic tangent.
 *
 * tanh(x) = (e^2x - 1)/(e^2x + 1)
 *
 * @note We clamp x to [-5,5] to avoid overflowing issues.
 *
 * @param[in] val Input vector value in F16 format.
 *
 * @return The calculated Hyperbolic Tangent.
 */
float16x8_t vtanhq_f16(float16x8_t val);

/** Calculate round value of a vector to nearest with ties to even.
 *
 * @param[in] val Input vector value in F16 format.
 *
 * @return The calculated round vector.
 */
float16x8_t vroundq_rte_f16(float16x8_t val);

/** Calculate reciprocal.
 *
 * @param[in] x Input value.
 *
 * @return The calculated reciprocal.
 */
float16x4_t vinv_f16(float16x4_t x);

/** Calculate reciprocal.
 *
 * @param[in] x Input value.
 *
 * @return The calculated reciprocal.
 */
float16x8_t vinvq_f16(float16x8_t x);

/** Calculate inverse square root.
 *
 * @param[in] x Input value.
 *
 * @return The calculated inverse square root.
 */
float16x4_t vinvsqrt_f16(float16x4_t x);

/** Calculate inverse square root.
 *
 * @param[in] x Input value.
 *
 * @return The calculated inverse square root.
 */
float16x8_t vinvsqrtq_f16(float16x8_t x);

/** Calculate exponential
 *
 * @param[in] x Input vector value in F16 format.
 *
 * @return The calculated exponent.
 */
float16x8_t vexpq_f16(float16x8_t x);

/** Calculate n power of a number.
 *
 * pow(x,n) = e^(n*log(x))
 *
 * @param[in] val Input vector value in F16 format.
 * @param[in] n   Powers to raise the input to.
 *
 * @return The calculated power.
 */
float16x8_t vpowq_f16(float16x8_t val, float16x8_t n);

/** Calculate sine.
 *
 * @param[in] val Input vector value in radians, F16 format.
 *
 * @return The calculated sine.
 */
float16x8_t vsinq_f16(float16x8_t val);

/** Reduce a vector to be a scalar by accumulating all lanes in the vector
 *
 * @param[in] v Vector to be reduced.
 *
 * @return the wrapped-around number.
 */
float16_t vreduce(const float16x8_t &v);
#endif /* __ARM_FEATURE_FP16_VECTOR_ARITHMETIC */
} // namespace arm_compute
#include "src/core/NEON/NEMath.inl"
#endif /* ARM_COMPUTE_NEMATH_H */