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/*
* Copyright (c) 2021, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
/*! \file
* This file contains several utility functions used to sort small arrays with
* sorting networks.
*
* Sorting network is a (potentially branch-less) way to quickly sort small
* arrays with known size. For more details, consult
*/
#ifndef AOM_AV1_ENCODER_SORTING_NETWORK_H_
#define AOM_AV1_ENCODER_SORTING_NETWORK_H_
#include "aom/aom_integer.h"
#define SWAP(i, j) \
do { \
const float maxf = (k[i] >= k[j]) ? k[i] : k[j]; \
const float minf = (k[i] >= k[j]) ? k[j] : k[i]; \
const int maxi = (k[i] >= k[j]) ? v[i] : v[j]; \
const int mini = (k[i] >= k[j]) ? v[j] : v[i]; \
k[i] = maxf; \
k[j] = minf; \
v[i] = maxi; \
v[j] = mini; \
} while (0)
/*!\brief Sorts two size-16 arrays of keys and values in descending order of
* keys.
*
* \param[in,out] k An length-16 array of float serves as the keys.
* \param[in,out] v An length-16 array of int32 serves as the
* value.
*/
static inline void av1_sort_fi32_16(float k[], int32_t v[]) {
SWAP(0, 1);
SWAP(2, 3);
SWAP(4, 5);
SWAP(6, 7);
SWAP(8, 9);
SWAP(10, 11);
SWAP(12, 13);
SWAP(14, 15);
SWAP(0, 2);
SWAP(1, 3);
SWAP(4, 6);
SWAP(5, 7);
SWAP(8, 10);
SWAP(9, 11);
SWAP(12, 14);
SWAP(13, 15);
SWAP(1, 2);
SWAP(5, 6);
SWAP(0, 4);
SWAP(3, 7);
SWAP(9, 10);
SWAP(13, 14);
SWAP(8, 12);
SWAP(11, 15);
SWAP(1, 5);
SWAP(2, 6);
SWAP(9, 13);
SWAP(10, 14);
SWAP(0, 8);
SWAP(7, 15);
SWAP(1, 4);
SWAP(3, 6);
SWAP(9, 12);
SWAP(11, 14);
SWAP(2, 4);
SWAP(3, 5);
SWAP(10, 12);
SWAP(11, 13);
SWAP(1, 9);
SWAP(6, 14);
SWAP(3, 4);
SWAP(11, 12);
SWAP(1, 8);
SWAP(2, 10);
SWAP(5, 13);
SWAP(7, 14);
SWAP(3, 11);
SWAP(2, 8);
SWAP(4, 12);
SWAP(7, 13);
SWAP(3, 10);
SWAP(5, 12);
SWAP(3, 9);
SWAP(6, 12);
SWAP(3, 8);
SWAP(7, 12);
SWAP(5, 9);
SWAP(6, 10);
SWAP(4, 8);
SWAP(7, 11);
SWAP(5, 8);
SWAP(7, 10);
SWAP(6, 8);
SWAP(7, 9);
SWAP(7, 8);
}
/*!\brief Sorts two size-8 arrays of keys and values in descending order of
* keys.
*
* \param[in,out] k An length-8 array of float serves as the keys.
* \param[in,out] v An length-8 array of int32 serves as the values.
*/
static inline void av1_sort_fi32_8(float k[], int32_t v[]) {
SWAP(0, 1);
SWAP(2, 3);
SWAP(4, 5);
SWAP(6, 7);
SWAP(0, 2);
SWAP(1, 3);
SWAP(4, 6);
SWAP(5, 7);
SWAP(1, 2);
SWAP(5, 6);
SWAP(0, 4);
SWAP(3, 7);
SWAP(1, 5);
SWAP(2, 6);
SWAP(1, 4);
SWAP(3, 6);
SWAP(2, 4);
SWAP(3, 5);
SWAP(3, 4);
}
#undef SWAP
#endif // AOM_AV1_ENCODER_SORTING_NETWORK_H_