| /* |
| * 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 <stdlib.h> |
| #include <memory.h> |
| #include <math.h> |
| #include <assert.h> |
| |
| #include <smmintrin.h> |
| |
| #include "config/aom_dsp_rtcd.h" |
| |
| #include "aom_ports/mem.h" |
| #include "aom_dsp/flow_estimation/corner_match.h" |
| |
| DECLARE_ALIGNED(16, static const uint8_t, |
| byte_mask[16]) = { 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 0, 0, 0 }; |
| #if MATCH_SZ != 13 |
| #error "Need to change byte_mask in corner_match_sse4.c if MATCH_SZ != 13" |
| #endif |
| |
| /* Compute corr(frame1, frame2) * MATCH_SZ * stddev(frame1), where the |
| correlation/standard deviation are taken over MATCH_SZ by MATCH_SZ windows |
| of each image, centered at (x1, y1) and (x2, y2) respectively. |
| */ |
| double av1_compute_cross_correlation_sse4_1(const unsigned char *frame1, |
| int stride1, int x1, int y1, |
| const unsigned char *frame2, |
| int stride2, int x2, int y2) { |
| int i; |
| // 2 16-bit partial sums in lanes 0, 4 (== 2 32-bit partial sums in lanes 0, |
| // 2) |
| __m128i sum1_vec = _mm_setzero_si128(); |
| __m128i sum2_vec = _mm_setzero_si128(); |
| // 4 32-bit partial sums of squares |
| __m128i sumsq2_vec = _mm_setzero_si128(); |
| __m128i cross_vec = _mm_setzero_si128(); |
| |
| const __m128i mask = _mm_load_si128((__m128i *)byte_mask); |
| const __m128i zero = _mm_setzero_si128(); |
| |
| frame1 += (y1 - MATCH_SZ_BY2) * stride1 + (x1 - MATCH_SZ_BY2); |
| frame2 += (y2 - MATCH_SZ_BY2) * stride2 + (x2 - MATCH_SZ_BY2); |
| |
| for (i = 0; i < MATCH_SZ; ++i) { |
| const __m128i v1 = |
| _mm_and_si128(_mm_loadu_si128((__m128i *)&frame1[i * stride1]), mask); |
| const __m128i v2 = |
| _mm_and_si128(_mm_loadu_si128((__m128i *)&frame2[i * stride2]), mask); |
| |
| // Using the 'sad' intrinsic here is a bit faster than adding |
| // v1_l + v1_r and v2_l + v2_r, plus it avoids the need for a 16->32 bit |
| // conversion step later, for a net speedup of ~10% |
| sum1_vec = _mm_add_epi16(sum1_vec, _mm_sad_epu8(v1, zero)); |
| sum2_vec = _mm_add_epi16(sum2_vec, _mm_sad_epu8(v2, zero)); |
| |
| const __m128i v1_l = _mm_cvtepu8_epi16(v1); |
| const __m128i v1_r = _mm_cvtepu8_epi16(_mm_srli_si128(v1, 8)); |
| const __m128i v2_l = _mm_cvtepu8_epi16(v2); |
| const __m128i v2_r = _mm_cvtepu8_epi16(_mm_srli_si128(v2, 8)); |
| |
| sumsq2_vec = _mm_add_epi32( |
| sumsq2_vec, |
| _mm_add_epi32(_mm_madd_epi16(v2_l, v2_l), _mm_madd_epi16(v2_r, v2_r))); |
| cross_vec = _mm_add_epi32( |
| cross_vec, |
| _mm_add_epi32(_mm_madd_epi16(v1_l, v2_l), _mm_madd_epi16(v1_r, v2_r))); |
| } |
| |
| // Now we can treat the four registers (sum1_vec, sum2_vec, sumsq2_vec, |
| // cross_vec) |
| // as holding 4 32-bit elements each, which we want to sum horizontally. |
| // We do this by transposing and then summing vertically. |
| __m128i tmp_0 = _mm_unpacklo_epi32(sum1_vec, sum2_vec); |
| __m128i tmp_1 = _mm_unpackhi_epi32(sum1_vec, sum2_vec); |
| __m128i tmp_2 = _mm_unpacklo_epi32(sumsq2_vec, cross_vec); |
| __m128i tmp_3 = _mm_unpackhi_epi32(sumsq2_vec, cross_vec); |
| |
| __m128i tmp_4 = _mm_unpacklo_epi64(tmp_0, tmp_2); |
| __m128i tmp_5 = _mm_unpackhi_epi64(tmp_0, tmp_2); |
| __m128i tmp_6 = _mm_unpacklo_epi64(tmp_1, tmp_3); |
| __m128i tmp_7 = _mm_unpackhi_epi64(tmp_1, tmp_3); |
| |
| __m128i res = |
| _mm_add_epi32(_mm_add_epi32(tmp_4, tmp_5), _mm_add_epi32(tmp_6, tmp_7)); |
| |
| int sum1 = _mm_extract_epi32(res, 0); |
| int sum2 = _mm_extract_epi32(res, 1); |
| int sumsq2 = _mm_extract_epi32(res, 2); |
| int cross = _mm_extract_epi32(res, 3); |
| |
| int var2 = sumsq2 * MATCH_SZ_SQ - sum2 * sum2; |
| int cov = cross * MATCH_SZ_SQ - sum1 * sum2; |
| return cov / sqrt((double)var2); |
| } |