/*

 * Copyright (c) 2018, 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.

 */

#include <stdint.h>

#include <smmintrin.h>

#include "config/av1_rtcd.h"

// Byte-boundary alignment issues

#define ALIGN_SIZE 8

#define ALIGN_MASK (ALIGN_SIZE - 1)

#define CALC_CRC(op, crc, type, buf, len) \

  while ((len) >= sizeof(type)) {         \

    (crc) = op((crc), *(type *)(buf));    \

    (len) -= sizeof(type);                \

    buf += sizeof(type);                  \

  }

/**

 * Calculates 32-bit CRC for the input buffer

 * polynomial is 0x11EDC6F41

 * @return A 32-bit unsigned integer representing the CRC

 */

uint32_t av1_get_crc32c_value_sse4_2(void *crc_calculator, const uint8_t *p,

                                     size_t len) {

  (void)crc_calculator;

  const uint8_t *buf = p;

  uint32_t crc = 0xFFFFFFFF;

  // Align the input to the word boundary

  for (; (len > 0) && ((intptr_t)buf & ALIGN_MASK); len--, buf++) {

    crc = _mm_crc32_u8(crc, *buf);

  }

#ifdef __x86_64__

  uint64_t crc64 = crc;

  CALC_CRC(_mm_crc32_u64, crc64, uint64_t, buf, len)

  crc = (uint32_t)crc64;

#endif

  CALC_CRC(_mm_crc32_u32, crc, uint32_t, buf, len)

  CALC_CRC(_mm_crc32_u16, crc, uint16_t, buf, len)

  CALC_CRC(_mm_crc32_u8, crc, uint8_t, buf, len)

  return (crc ^ 0xFFFFFFFF);

}