av1/common/cfl_avx2.c - aom - Git at Google

 /*
  * Copyright (c) 2017, 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 <immintrin.h>

 #include "./av1_rtcd.h"

 #include "av1/common/cfl.h"

 /**
  * Subtracts avg_q3 from the active part of the CfL prediction buffer.
  *
  * The CfL prediction buffer is always of size CFL_BUF_SQUARE. However, the
  * active area is specified using width and height.
  *
  * Note: We don't need to worry about going over the active area, as long as we
  * stay inside the CfL prediction buffer.
  */
 void av1_cfl_subtract_avx2(int16_t *pred_buf_q3, int width, int height,
                            int16_t avg_q3) {
   const __m256i avg_x16 = _mm256_set1_epi16(avg_q3);

   // Sixteen int16 values fit in one __m256i register. If this is enough to do
   // the entire row, we move to the next row (stride ==32), otherwise we move to
   // the next sixteen values.
   //   width   next
   //     4      32
   //     8      32
   //    16      32
   //    32      16
   const int stride = CFL_BUF_LINE >> (width == 32);

   const int16_t *end = pred_buf_q3 + height * CFL_BUF_LINE;
   do {
     __m256i val_x16 = _mm256_loadu_si256((__m256i *)pred_buf_q3);
     _mm256_storeu_si256((__m256i *)pred_buf_q3,
                         _mm256_sub_epi16(val_x16, avg_x16));
   } while ((pred_buf_q3 += stride) < end);
 }

 /**
  * Adds 4 pixels (in a 2x2 grid) and multiplies them by 2. Resulting in a more
  * precise version of a box filter 4:2:0 pixel subsampling in Q3.
  *
  * The CfL prediction buffer is always of size CFL_BUF_SQUARE. However, the
  * active area is specified using width and height.
  *
  * Note: We don't need to worry about going over the active area, as long as we
  * stay inside the CfL prediction buffer.
  *
  * Note: For 4:2:0 luma subsampling, the width will never be greater than 16.
  */
 static void cfl_luma_subsampling_420_lbd_avx2(const uint8_t *input,
                                               int input_stride,
                                               int16_t *pred_buf_q3, int width,
                                               int height) {
   (void)width;  // Max chroma width is 16, so all widths fit in one __m256i

   const __m256i twos = _mm256_set1_epi8(2);  // Thirty two twos
   const int luma_stride = input_stride << 1;
   const int16_t *end = pred_buf_q3 + height * CFL_BUF_LINE;
   do {
     // Load 32 values for the top and bottom rows.
     // t_0, t_1, ... t_31
     __m256i top = _mm256_loadu_si256((__m256i *)(input));
     // b_0, b_1, ... b_31
     __m256i bot = _mm256_loadu_si256((__m256i *)(input + input_stride));

     // Horizontal add of the 32 values into 16 values that are multiplied by 2
     // (t_0 + t_1) * 2, (t_2 + t_3) * 2, ... (t_30 + t_31) *2
     top = _mm256_maddubs_epi16(top, twos);
     // (b_0 + b_1) * 2, (b_2 + b_3) * 2, ... (b_30 + b_31) *2
     bot = _mm256_maddubs_epi16(bot, twos);

     // Add the 16 values in top with the 16 values in bottom
     _mm256_storeu_si256((__m256i *)pred_buf_q3, _mm256_add_epi16(top, bot));

     input += luma_stride;
     pred_buf_q3 += CFL_BUF_LINE;
   } while (pred_buf_q3 < end);
 }

 cfl_subsample_lbd_fn get_subsample_lbd_fn_avx2(int sub_x, int sub_y) {
   static const cfl_subsample_lbd_fn subsample_lbd[2][2] = {
     //  (sub_y == 0, sub_x == 0)       (sub_y == 0, sub_x == 1)
     //  (sub_y == 1, sub_x == 0)       (sub_y == 1, sub_x == 1)
     { cfl_luma_subsampling_444_lbd, cfl_luma_subsampling_422_lbd },
     { cfl_luma_subsampling_440_lbd, cfl_luma_subsampling_420_lbd_avx2 },
   };
   // AND sub_x and sub_y with 1 to ensures that an attacker won't be able to
   // index the function pointer array out of bounds.
   return subsample_lbd[sub_y & 1][sub_x & 1];
 }

 static INLINE __m256i predict_unclipped(const __m256i *input, __m256i alpha_q12,
                                         __m256i alpha_sign, __m256i dc_q0) {
   __m256i ac_q3 = _mm256_loadu_si256(input);
   __m256i ac_sign = _mm256_sign_epi16(alpha_sign, ac_q3);
   __m256i scaled_luma_q0 =
       _mm256_mulhrs_epi16(_mm256_abs_epi16(ac_q3), alpha_q12);
   scaled_luma_q0 = _mm256_sign_epi16(scaled_luma_q0, ac_sign);
   return _mm256_add_epi16(scaled_luma_q0, dc_q0);
 }

 static INLINE void cfl_predict_lbd_x(const int16_t *pred_buf_q3, uint8_t *dst,
                                      int dst_stride, TX_SIZE tx_size,
                                      int alpha_q3, int width) {
   const int16_t *row_end = pred_buf_q3 + tx_size_high[tx_size] * CFL_BUF_LINE;
   const __m256i alpha_sign = _mm256_set1_epi16(alpha_q3);
   const __m256i alpha_q12 = _mm256_slli_epi16(_mm256_abs_epi16(alpha_sign), 9);
   const __m256i dc_q0 = _mm256_set1_epi16(*dst);
   do {
     __m256i res =
         predict_unclipped((__m256i *)pred_buf_q3, alpha_q12, alpha_sign, dc_q0);
     __m256i next = res;
     if (width == 32)
       next = predict_unclipped((__m256i *)(pred_buf_q3 + 16), alpha_q12,
                                alpha_sign, dc_q0);
     res = _mm256_packus_epi16(res, next);
     if (width == 4) {
       *(int32_t *)dst = _mm256_extract_epi32(res, 0);
     } else if (width == 8) {
 #ifdef __x86_64__
       *(int64_t *)dst = _mm256_extract_epi64(res, 0);
 #else
       _mm_storel_epi64((__m128i *)dst, _mm256_castsi256_si128(res));
 #endif
     } else {
       res = _mm256_permute4x64_epi64(res, _MM_SHUFFLE(3, 1, 2, 0));
       if (width == 16)
         _mm_storeu_si128((__m128i *)dst, _mm256_castsi256_si128(res));
       else
         _mm256_storeu_si256((__m256i *)dst, res);
     }
     dst += dst_stride;
     pred_buf_q3 += CFL_BUF_LINE;
   } while (pred_buf_q3 < row_end);
 }

 static __m256i highbd_max_epi16(int bd) {
   const __m256i neg_one = _mm256_set1_epi16(-1);
   // (1 << bd) - 1 => -(-1 << bd) -1 => -1 - (-1 << bd) => -1 ^ (-1 << bd)
   return _mm256_xor_si256(_mm256_slli_epi16(neg_one, bd), neg_one);
 }

 static __m256i highbd_clamp_epi16(__m256i u, __m256i zero, __m256i max) {
   return _mm256_max_epi16(_mm256_min_epi16(u, max), zero);
 }

 static INLINE void cfl_predict_hbd_x(const int16_t *pred_buf_q3, uint16_t *dst,
                                      int dst_stride, TX_SIZE tx_size,
                                      int alpha_q3, int bd, int width) {
   const int16_t *row_end = pred_buf_q3 + tx_size_high[tx_size] * CFL_BUF_LINE;
   const __m256i alpha_sign = _mm256_set1_epi16(alpha_q3);
   const __m256i alpha_q12 = _mm256_slli_epi16(_mm256_abs_epi16(alpha_sign), 9);
   const __m256i dc_q0 = _mm256_loadu_si256((__m256i *)dst);
   const __m256i max = highbd_max_epi16(bd);
   const __m256i zero = _mm256_setzero_si256();
   do {
     __m256i res =
         predict_unclipped((__m256i *)pred_buf_q3, alpha_q12, alpha_sign, dc_q0);
     res = highbd_clamp_epi16(res, zero, max);
     if (width == 4)
 #ifdef __x86_64__
       *(int64_t *)dst = _mm256_extract_epi64(res, 0);
 #else
       _mm_storel_epi64((__m128i *)dst, _mm256_castsi256_si128(res));
 #endif
     else if (width == 8)
       _mm_storeu_si128((__m128i *)dst, _mm256_castsi256_si128(res));
     else
       _mm256_storeu_si256((__m256i *)dst, res);
     if (width == 32) {
       res = predict_unclipped((__m256i *)(pred_buf_q3 + 16), alpha_q12,
                               alpha_sign, dc_q0);
       res = highbd_clamp_epi16(res, zero, max);
       _mm256_storeu_si256((__m256i *)(dst + 16), res);
     }
     dst += dst_stride;
     pred_buf_q3 += CFL_BUF_LINE;
   } while (pred_buf_q3 < row_end);
 }

 #define CFL_PREDICT_LBD_X(width)                                               \
   static void cfl_predict_lbd_##width(const int16_t *pred_buf_q3,              \
                                       uint8_t *dst, int dst_stride,            \
                                       TX_SIZE tx_size, int alpha_q3) {         \
     cfl_predict_lbd_x(pred_buf_q3, dst, dst_stride, tx_size, alpha_q3, width); \
   }

 CFL_PREDICT_LBD_X(4)
 CFL_PREDICT_LBD_X(8)
 CFL_PREDICT_LBD_X(16)
 CFL_PREDICT_LBD_X(32)

 #define CFL_PREDICT_HBD_X(width)                                               \
   static void cfl_predict_hbd_##width(const int16_t *pred_buf_q3,              \
                                       uint16_t *dst, int dst_stride,           \
                                       TX_SIZE tx_size, int alpha_q3, int bd) { \
     cfl_predict_hbd_x(pred_buf_q3, dst, dst_stride, tx_size, alpha_q3, bd,     \
                       width);                                                  \
   }

 CFL_PREDICT_HBD_X(4)
 CFL_PREDICT_HBD_X(8)
 CFL_PREDICT_HBD_X(16)
 CFL_PREDICT_HBD_X(32)

 cfl_predict_lbd_fn get_predict_lbd_fn_avx2(TX_SIZE tx_size) {
   static const cfl_predict_lbd_fn predict_lbd[4] = {
     cfl_predict_lbd_4, cfl_predict_lbd_8, cfl_predict_lbd_16, cfl_predict_lbd_32
   };
   return predict_lbd[(tx_size_wide_log2[tx_size] - tx_size_wide_log2[0]) & 3];
 }

 cfl_predict_hbd_fn get_predict_hbd_fn_avx2(TX_SIZE tx_size) {
   static const cfl_predict_hbd_fn predict_hbd[4] = {
     cfl_predict_hbd_4, cfl_predict_hbd_8, cfl_predict_hbd_16, cfl_predict_hbd_32
   };
   return predict_hbd[(tx_size_wide_log2[tx_size] - tx_size_wide_log2[0]) & 3];
 }
	/*
	* Copyright (c) 2017, 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 <immintrin.h>

	#include "./av1_rtcd.h"

	#include "av1/common/cfl.h"

	/**
	* Subtracts avg_q3 from the active part of the CfL prediction buffer.
	*
	* The CfL prediction buffer is always of size CFL_BUF_SQUARE. However, the
	* active area is specified using width and height.
	*
	* Note: We don't need to worry about going over the active area, as long as we
	* stay inside the CfL prediction buffer.
	*/
	void av1_cfl_subtract_avx2(int16_t *pred_buf_q3, int width, int height,
	int16_t avg_q3) {
	const __m256i avg_x16 = _mm256_set1_epi16(avg_q3);

	// Sixteen int16 values fit in one __m256i register. If this is enough to do
	// the entire row, we move to the next row (stride ==32), otherwise we move to
	// the next sixteen values.
	// width next
	// 4 32
	// 8 32
	// 16 32
	// 32 16
	const int stride = CFL_BUF_LINE >> (width == 32);

	const int16_t end = pred_buf_q3 + height CFL_BUF_LINE;
	do {
	__m256i val_x16 = _mm256_loadu_si256((__m256i *)pred_buf_q3);
	_mm256_storeu_si256((__m256i *)pred_buf_q3,
	_mm256_sub_epi16(val_x16, avg_x16));
	} while ((pred_buf_q3 += stride) < end);
	}

	/**
	* Adds 4 pixels (in a 2x2 grid) and multiplies them by 2. Resulting in a more
	* precise version of a box filter 4:2:0 pixel subsampling in Q3.
	*
	* The CfL prediction buffer is always of size CFL_BUF_SQUARE. However, the
	* active area is specified using width and height.
	*
	* Note: We don't need to worry about going over the active area, as long as we
	* stay inside the CfL prediction buffer.
	*
	* Note: For 4:2:0 luma subsampling, the width will never be greater than 16.
	*/
	static void cfl_luma_subsampling_420_lbd_avx2(const uint8_t *input,
	int input_stride,
	int16_t *pred_buf_q3, int width,
	int height) {
	(void)width; // Max chroma width is 16, so all widths fit in one __m256i

	const __m256i twos = _mm256_set1_epi8(2); // Thirty two twos
	const int luma_stride = input_stride << 1;
	const int16_t end = pred_buf_q3 + height CFL_BUF_LINE;
	do {
	// Load 32 values for the top and bottom rows.
	// t_0, t_1, ... t_31
	__m256i top = _mm256_loadu_si256((__m256i *)(input));
	// b_0, b_1, ... b_31
	__m256i bot = _mm256_loadu_si256((__m256i *)(input + input_stride));

	// Horizontal add of the 32 values into 16 values that are multiplied by 2
	// (t_0 + t_1) * 2, (t_2 + t_3) * 2, ... (t_30 + t_31) *2
	top = _mm256_maddubs_epi16(top, twos);
	// (b_0 + b_1) * 2, (b_2 + b_3) * 2, ... (b_30 + b_31) *2
	bot = _mm256_maddubs_epi16(bot, twos);

	// Add the 16 values in top with the 16 values in bottom
	_mm256_storeu_si256((__m256i *)pred_buf_q3, _mm256_add_epi16(top, bot));

	input += luma_stride;
	pred_buf_q3 += CFL_BUF_LINE;
	} while (pred_buf_q3 < end);
	}

	cfl_subsample_lbd_fn get_subsample_lbd_fn_avx2(int sub_x, int sub_y) {
	static const cfl_subsample_lbd_fn subsample_lbd[2][2] = {
	// (sub_y == 0, sub_x == 0) (sub_y == 0, sub_x == 1)
	// (sub_y == 1, sub_x == 0) (sub_y == 1, sub_x == 1)
	{ cfl_luma_subsampling_444_lbd, cfl_luma_subsampling_422_lbd },
	{ cfl_luma_subsampling_440_lbd, cfl_luma_subsampling_420_lbd_avx2 },
	};
	// AND sub_x and sub_y with 1 to ensures that an attacker won't be able to
	// index the function pointer array out of bounds.
	return subsample_lbd[sub_y & 1][sub_x & 1];
	}

	static INLINE __m256i predict_unclipped(const __m256i *input, __m256i alpha_q12,
	__m256i alpha_sign, __m256i dc_q0) {
	__m256i ac_q3 = _mm256_loadu_si256(input);
	__m256i ac_sign = _mm256_sign_epi16(alpha_sign, ac_q3);
	__m256i scaled_luma_q0 =
	_mm256_mulhrs_epi16(_mm256_abs_epi16(ac_q3), alpha_q12);
	scaled_luma_q0 = _mm256_sign_epi16(scaled_luma_q0, ac_sign);
	return _mm256_add_epi16(scaled_luma_q0, dc_q0);
	}

	static INLINE void cfl_predict_lbd_x(const int16_t pred_buf_q3, uint8_t dst,
	int dst_stride, TX_SIZE tx_size,
	int alpha_q3, int width) {
	const int16_t row_end = pred_buf_q3 + tx_size_high[tx_size] CFL_BUF_LINE;
	const __m256i alpha_sign = _mm256_set1_epi16(alpha_q3);
	const __m256i alpha_q12 = _mm256_slli_epi16(_mm256_abs_epi16(alpha_sign), 9);
	const __m256i dc_q0 = _mm256_set1_epi16(*dst);
	do {
	__m256i res =
	predict_unclipped((__m256i *)pred_buf_q3, alpha_q12, alpha_sign, dc_q0);
	__m256i next = res;
	if (width == 32)
	next = predict_unclipped((__m256i *)(pred_buf_q3 + 16), alpha_q12,
	alpha_sign, dc_q0);
	res = _mm256_packus_epi16(res, next);
	if (width == 4) {
	(int32_t )dst = _mm256_extract_epi32(res, 0);
	} else if (width == 8) {
	#ifdef __x86_64__
	(int64_t )dst = _mm256_extract_epi64(res, 0);
	#else
	_mm_storel_epi64((__m128i *)dst, _mm256_castsi256_si128(res));
	#endif
	} else {
	res = _mm256_permute4x64_epi64(res, _MM_SHUFFLE(3, 1, 2, 0));
	if (width == 16)
	_mm_storeu_si128((__m128i *)dst, _mm256_castsi256_si128(res));
	else
	_mm256_storeu_si256((__m256i *)dst, res);
	}
	dst += dst_stride;
	pred_buf_q3 += CFL_BUF_LINE;
	} while (pred_buf_q3 < row_end);
	}

	static __m256i highbd_max_epi16(int bd) {
	const __m256i neg_one = _mm256_set1_epi16(-1);
	// (1 << bd) - 1 => -(-1 << bd) -1 => -1 - (-1 << bd) => -1 ^ (-1 << bd)
	return _mm256_xor_si256(_mm256_slli_epi16(neg_one, bd), neg_one);
	}

	static __m256i highbd_clamp_epi16(__m256i u, __m256i zero, __m256i max) {
	return _mm256_max_epi16(_mm256_min_epi16(u, max), zero);
	}

	static INLINE void cfl_predict_hbd_x(const int16_t pred_buf_q3, uint16_t dst,
	int dst_stride, TX_SIZE tx_size,
	int alpha_q3, int bd, int width) {
	const int16_t row_end = pred_buf_q3 + tx_size_high[tx_size] CFL_BUF_LINE;
	const __m256i alpha_sign = _mm256_set1_epi16(alpha_q3);
	const __m256i alpha_q12 = _mm256_slli_epi16(_mm256_abs_epi16(alpha_sign), 9);
	const __m256i dc_q0 = _mm256_loadu_si256((__m256i *)dst);
	const __m256i max = highbd_max_epi16(bd);
	const __m256i zero = _mm256_setzero_si256();
	do {
	__m256i res =
	predict_unclipped((__m256i *)pred_buf_q3, alpha_q12, alpha_sign, dc_q0);
	res = highbd_clamp_epi16(res, zero, max);
	if (width == 4)
	#ifdef __x86_64__
	(int64_t )dst = _mm256_extract_epi64(res, 0);
	#else
	_mm_storel_epi64((__m128i *)dst, _mm256_castsi256_si128(res));
	#endif
	else if (width == 8)
	_mm_storeu_si128((__m128i *)dst, _mm256_castsi256_si128(res));
	else
	_mm256_storeu_si256((__m256i *)dst, res);
	if (width == 32) {
	res = predict_unclipped((__m256i *)(pred_buf_q3 + 16), alpha_q12,
	alpha_sign, dc_q0);
	res = highbd_clamp_epi16(res, zero, max);
	_mm256_storeu_si256((__m256i *)(dst + 16), res);
	}
	dst += dst_stride;
	pred_buf_q3 += CFL_BUF_LINE;
	} while (pred_buf_q3 < row_end);
	}

	#define CFL_PREDICT_LBD_X(width) \
	static void cfl_predict_lbd_##width(const int16_t *pred_buf_q3, \
	uint8_t *dst, int dst_stride, \
	TX_SIZE tx_size, int alpha_q3) { \
	cfl_predict_lbd_x(pred_buf_q3, dst, dst_stride, tx_size, alpha_q3, width); \
	}

	CFL_PREDICT_LBD_X(4)
	CFL_PREDICT_LBD_X(8)
	CFL_PREDICT_LBD_X(16)
	CFL_PREDICT_LBD_X(32)

	#define CFL_PREDICT_HBD_X(width) \
	static void cfl_predict_hbd_##width(const int16_t *pred_buf_q3, \
	uint16_t *dst, int dst_stride, \
	TX_SIZE tx_size, int alpha_q3, int bd) { \
	cfl_predict_hbd_x(pred_buf_q3, dst, dst_stride, tx_size, alpha_q3, bd, \
	width); \
	}

	CFL_PREDICT_HBD_X(4)
	CFL_PREDICT_HBD_X(8)
	CFL_PREDICT_HBD_X(16)
	CFL_PREDICT_HBD_X(32)

	cfl_predict_lbd_fn get_predict_lbd_fn_avx2(TX_SIZE tx_size) {
	static const cfl_predict_lbd_fn predict_lbd[4] = {
	cfl_predict_lbd_4, cfl_predict_lbd_8, cfl_predict_lbd_16, cfl_predict_lbd_32
	};
	return predict_lbd[(tx_size_wide_log2[tx_size] - tx_size_wide_log2[0]) & 3];
	}

	cfl_predict_hbd_fn get_predict_hbd_fn_avx2(TX_SIZE tx_size) {
	static const cfl_predict_hbd_fn predict_hbd[4] = {
	cfl_predict_hbd_4, cfl_predict_hbd_8, cfl_predict_hbd_16, cfl_predict_hbd_32
	};
	return predict_hbd[(tx_size_wide_log2[tx_size] - tx_size_wide_log2[0]) & 3];
	}