/*
 * Copyright (c) 2021, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 3-Clause Clear License
 * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear
 * License was not distributed with this source code in the LICENSE file, you
 * can obtain it at aomedia.org/license/software-license/bsd-3-c-c/.  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
 * aomedia.org/license/patent-license/.
 */

#ifndef AOM_AOM_DSP_X86_SYNONYMS_H_
#define AOM_AOM_DSP_X86_SYNONYMS_H_

#include <immintrin.h>
#include <string.h>

#include "config/aom_config.h"

#include "aom/aom_integer.h"

/**
 * Various reusable shorthands for x86 SIMD intrinsics.
 *
 * Intrinsics prefixed with xx_ operate on or return 128bit XMM registers.
 * Intrinsics prefixed with yy_ operate on or return 256bit YMM registers.
 */

// Loads and stores to do away with the tedium of casting the address
// to the right type.
static INLINE __m128i xx_loadl_32(const void *a) {
  int val;
  memcpy(&val, a, sizeof(val));
  return _mm_cvtsi32_si128(val);
}

static INLINE __m128i xx_loadl_64(const void *a) {
  return _mm_loadl_epi64((const __m128i *)a);
}

static INLINE __m128i xx_loadu_128(const void *a) {
  return _mm_loadu_si128((const __m128i *)a);
}

static INLINE __m128i xx_load_128(const void *a) { return xx_loadu_128(a); }

// Load 64 bits from each of hi and low, and pack into an SSE register
// Since directly loading as `int64_t`s and using _mm_set_epi64 may violate
// the strict aliasing rule, this takes a different approach
static INLINE __m128i xx_loadu_2x64(const void *hi, const void *lo) {
  return _mm_unpacklo_epi64(_mm_loadu_si64(lo), _mm_loadu_si64(hi));
}

static INLINE void xx_storel_32(void *const a, const __m128i v) {
  const int val = _mm_cvtsi128_si32(v);
  memcpy(a, &val, sizeof(val));
}

static INLINE void xx_storel_64(void *const a, const __m128i v) {
  _mm_storel_epi64((__m128i *)a, v);
}

static INLINE void xx_store_128(void *const a, const __m128i v) {
  _mm_store_si128((__m128i *)a, v);
}

static INLINE void xx_storeu_128(void *const a, const __m128i v) {
  _mm_storeu_si128((__m128i *)a, v);
}

// The _mm_set_epi64x() intrinsic is undefined for some Visual Studio
// compilers. The following function is equivalent to _mm_set_epi64x()
// acting on 32-bit integers.
static INLINE __m128i xx_set_64_from_32i(int32_t e1, int32_t e0) {
#if defined(_MSC_VER) && _MSC_VER < 1900
  return _mm_set_epi32(0, e1, 0, e0);
#else
  return _mm_set_epi64x((uint32_t)e1, (uint32_t)e0);
#endif
}

// The _mm_set1_epi64x() intrinsic is undefined for some Visual Studio
// compilers. The following function is equivalent to _mm_set1_epi64x()
// acting on a 32-bit integer.
static INLINE __m128i xx_set1_64_from_32i(int32_t a) {
#if defined(_MSC_VER) && _MSC_VER < 1900
  return _mm_set_epi32(0, a, 0, a);
#else
  return _mm_set1_epi64x((uint32_t)a);
#endif
}

static INLINE __m128i xx_round_epu16(__m128i v_val_w) {
  return _mm_avg_epu16(v_val_w, _mm_setzero_si128());
}

static INLINE __m128i xx_roundn_epu16(__m128i v_val_w, int bits) {
  const __m128i v_s_w = _mm_srli_epi16(v_val_w, bits - 1);
  return _mm_avg_epu16(v_s_w, _mm_setzero_si128());
}

static INLINE __m128i xx_roundn_epu32(__m128i v_val_d, int bits) {
  const __m128i v_bias_d = _mm_set1_epi32((1 << bits) >> 1);
  const __m128i v_tmp_d = _mm_add_epi32(v_val_d, v_bias_d);
  return _mm_srli_epi32(v_tmp_d, bits);
}

// This is equivalent to ROUND_POWER_OF_TWO(v_val_d, bits)
static INLINE __m128i xx_roundn_epi32_unsigned(__m128i v_val_d, int bits) {
  const __m128i v_bias_d = _mm_set1_epi32((1 << bits) >> 1);
  const __m128i v_tmp_d = _mm_add_epi32(v_val_d, v_bias_d);
  return _mm_srai_epi32(v_tmp_d, bits);
}

static INLINE __m128i xx_roundn_epi16(__m128i v_val_d, int bits) {
  const __m128i v_bias_d = _mm_set1_epi16((1 << bits) >> 1);
  const __m128i v_sign_d = _mm_srai_epi16(v_val_d, 15);
  const __m128i v_tmp_d =
      _mm_add_epi16(_mm_add_epi16(v_val_d, v_bias_d), v_sign_d);
  return _mm_srai_epi16(v_tmp_d, bits);
}

#endif  // AOM_AOM_DSP_X86_SYNONYMS_H_