arm_compute/core/NEON/NEMath.h

/*
 * Copyright (c) 2016-2019 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>

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 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);

#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);
#endif /* __ARM_FEATURE_FP16_VECTOR_ARITHMETIC */
} // namespace arm_compute
#include "arm_compute/core/NEON/NEMath.inl"
#endif /* __ARM_COMPUTE_NEMATH_H__ */