1 /*
2 * Copyright (c) 2018, Alliance for Open Media. All rights reserved.
3 *
4 * This source code is subject to the terms of the BSD 2 Clause License and
5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6 * was not distributed with this source code in the LICENSE file, you can
7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8 * Media Patent License 1.0 was not distributed with this source code in the
9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10 */
11
12 #include <assert.h>
13 #include <immintrin.h>
14 #include "aom_dsp/x86/mem_sse2.h"
15 #include "aom_dsp/x86/synonyms_avx2.h"
16
17 #include "config/av1_rtcd.h"
18 #include "av1/encoder/rdopt.h"
19
20 // Process horizontal and vertical correlations in a 4x4 block of pixels.
21 // We actually use the 4x4 pixels to calculate correlations corresponding to
22 // the top-left 3x3 pixels, so this function must be called with 1x1 overlap,
23 // moving the window along/down by 3 pixels at a time.
horver_correlation_4x4(const int16_t * diff,int stride,__m256i * xy_sum_32,__m256i * xz_sum_32,__m256i * x_sum_32,__m256i * x2_sum_32)24 static inline void horver_correlation_4x4(const int16_t *diff, int stride,
25 __m256i *xy_sum_32,
26 __m256i *xz_sum_32, __m256i *x_sum_32,
27 __m256i *x2_sum_32) {
28 // Pixels in this 4x4 [ a b c d ]
29 // are referred to as: [ e f g h ]
30 // [ i j k l ]
31 // [ m n o p ]
32
33 const __m256i pixels = _mm256_set_epi64x(
34 loadu_int64(&diff[0 * stride]), loadu_int64(&diff[1 * stride]),
35 loadu_int64(&diff[2 * stride]), loadu_int64(&diff[3 * stride]));
36 // pixels = [d c b a h g f e] [l k j i p o n m] as i16
37
38 const __m256i slli = _mm256_slli_epi64(pixels, 16);
39 // slli = [c b a 0 g f e 0] [k j i 0 o n m 0] as i16
40
41 const __m256i madd_xy = _mm256_madd_epi16(pixels, slli);
42 // madd_xy = [bc+cd ab fg+gh ef] [jk+kl ij no+op mn] as i32
43 *xy_sum_32 = _mm256_add_epi32(*xy_sum_32, madd_xy);
44
45 // Permute control [3 2] [1 0] => [2 1] [0 0], 0b10010000 = 0x90
46 const __m256i perm = _mm256_permute4x64_epi64(slli, 0x90);
47 // perm = [g f e 0 k j i 0] [o n m 0 o n m 0] as i16
48
49 const __m256i madd_xz = _mm256_madd_epi16(slli, perm);
50 // madd_xz = [cg+bf ae gk+fj ei] [ko+jn im oo+nn mm] as i32
51 *xz_sum_32 = _mm256_add_epi32(*xz_sum_32, madd_xz);
52
53 // Sum every element in slli (and then also their squares)
54 const __m256i madd1_slli = _mm256_madd_epi16(slli, _mm256_set1_epi16(1));
55 // madd1_slli = [c+b a g+f e] [k+j i o+n m] as i32
56 *x_sum_32 = _mm256_add_epi32(*x_sum_32, madd1_slli);
57
58 const __m256i madd_slli = _mm256_madd_epi16(slli, slli);
59 // madd_slli = [cc+bb aa gg+ff ee] [kk+jj ii oo+nn mm] as i32
60 *x2_sum_32 = _mm256_add_epi32(*x2_sum_32, madd_slli);
61 }
62
av1_get_horver_correlation_full_avx2(const int16_t * diff,int stride,int width,int height,float * hcorr,float * vcorr)63 void av1_get_horver_correlation_full_avx2(const int16_t *diff, int stride,
64 int width, int height, float *hcorr,
65 float *vcorr) {
66 // The following notation is used:
67 // x - current pixel
68 // y - right neighbour pixel
69 // z - below neighbour pixel
70 // w - down-right neighbour pixel
71 int64_t xy_sum = 0, xz_sum = 0;
72 int64_t x_sum = 0, x2_sum = 0;
73
74 // Process horizontal and vertical correlations through the body in 4x4
75 // blocks. This excludes the final row and column and possibly one extra
76 // column depending how 3 divides into width and height
77 int32_t xy_xz_tmp[8] = { 0 }, x_x2_tmp[8] = { 0 };
78 __m256i xy_sum_32 = _mm256_setzero_si256();
79 __m256i xz_sum_32 = _mm256_setzero_si256();
80 __m256i x_sum_32 = _mm256_setzero_si256();
81 __m256i x2_sum_32 = _mm256_setzero_si256();
82 for (int i = 0; i <= height - 4; i += 3) {
83 for (int j = 0; j <= width - 4; j += 3) {
84 horver_correlation_4x4(&diff[i * stride + j], stride, &xy_sum_32,
85 &xz_sum_32, &x_sum_32, &x2_sum_32);
86 }
87 const __m256i hadd_xy_xz = _mm256_hadd_epi32(xy_sum_32, xz_sum_32);
88 // hadd_xy_xz = [ae+bf+cg ei+fj+gk ab+bc+cd ef+fg+gh]
89 // [im+jn+ko mm+nn+oo ij+jk+kl mn+no+op] as i32
90 yy_storeu_256(xy_xz_tmp, hadd_xy_xz);
91 xy_sum += (int64_t)xy_xz_tmp[5] + xy_xz_tmp[4] + xy_xz_tmp[1];
92 xz_sum += (int64_t)xy_xz_tmp[7] + xy_xz_tmp[6] + xy_xz_tmp[3];
93
94 const __m256i hadd_x_x2 = _mm256_hadd_epi32(x_sum_32, x2_sum_32);
95 // hadd_x_x2 = [aa+bb+cc ee+ff+gg a+b+c e+f+g]
96 // [ii+jj+kk mm+nn+oo i+j+k m+n+o] as i32
97 yy_storeu_256(x_x2_tmp, hadd_x_x2);
98 x_sum += (int64_t)x_x2_tmp[5] + x_x2_tmp[4] + x_x2_tmp[1];
99 x2_sum += (int64_t)x_x2_tmp[7] + x_x2_tmp[6] + x_x2_tmp[3];
100
101 xy_sum_32 = _mm256_setzero_si256();
102 xz_sum_32 = _mm256_setzero_si256();
103 x_sum_32 = _mm256_setzero_si256();
104 x2_sum_32 = _mm256_setzero_si256();
105 }
106
107 // x_sum now covers every pixel except the final 1-2 rows and 1-2 cols
108 int64_t x_finalrow = 0, x_finalcol = 0, x2_finalrow = 0, x2_finalcol = 0;
109
110 // Do we have 2 rows remaining or just the one? Note that width and height
111 // are powers of 2, so each modulo 3 must be 1 or 2.
112 if (height % 3 == 1) { // Just horiz corrs on the final row
113 const int16_t x0 = diff[(height - 1) * stride];
114 x_sum += x0;
115 x_finalrow += x0;
116 x2_sum += x0 * x0;
117 x2_finalrow += x0 * x0;
118 for (int j = 0; j < width - 1; ++j) {
119 const int16_t x = diff[(height - 1) * stride + j];
120 const int16_t y = diff[(height - 1) * stride + j + 1];
121 xy_sum += x * y;
122 x_sum += y;
123 x2_sum += y * y;
124 x_finalrow += y;
125 x2_finalrow += y * y;
126 }
127 } else { // Two rows remaining to do
128 const int16_t x0 = diff[(height - 2) * stride];
129 const int16_t z0 = diff[(height - 1) * stride];
130 x_sum += x0 + z0;
131 x2_sum += x0 * x0 + z0 * z0;
132 x_finalrow += z0;
133 x2_finalrow += z0 * z0;
134 for (int j = 0; j < width - 1; ++j) {
135 const int16_t x = diff[(height - 2) * stride + j];
136 const int16_t y = diff[(height - 2) * stride + j + 1];
137 const int16_t z = diff[(height - 1) * stride + j];
138 const int16_t w = diff[(height - 1) * stride + j + 1];
139
140 // Horizontal and vertical correlations for the penultimate row:
141 xy_sum += x * y;
142 xz_sum += x * z;
143
144 // Now just horizontal correlations for the final row:
145 xy_sum += z * w;
146
147 x_sum += y + w;
148 x2_sum += y * y + w * w;
149 x_finalrow += w;
150 x2_finalrow += w * w;
151 }
152 }
153
154 // Do we have 2 columns remaining or just the one?
155 if (width % 3 == 1) { // Just vert corrs on the final col
156 const int16_t x0 = diff[width - 1];
157 x_sum += x0;
158 x_finalcol += x0;
159 x2_sum += x0 * x0;
160 x2_finalcol += x0 * x0;
161 for (int i = 0; i < height - 1; ++i) {
162 const int16_t x = diff[i * stride + width - 1];
163 const int16_t z = diff[(i + 1) * stride + width - 1];
164 xz_sum += x * z;
165 x_finalcol += z;
166 x2_finalcol += z * z;
167 // So the bottom-right elements don't get counted twice:
168 if (i < height - (height % 3 == 1 ? 2 : 3)) {
169 x_sum += z;
170 x2_sum += z * z;
171 }
172 }
173 } else { // Two cols remaining
174 const int16_t x0 = diff[width - 2];
175 const int16_t y0 = diff[width - 1];
176 x_sum += x0 + y0;
177 x2_sum += x0 * x0 + y0 * y0;
178 x_finalcol += y0;
179 x2_finalcol += y0 * y0;
180 for (int i = 0; i < height - 1; ++i) {
181 const int16_t x = diff[i * stride + width - 2];
182 const int16_t y = diff[i * stride + width - 1];
183 const int16_t z = diff[(i + 1) * stride + width - 2];
184 const int16_t w = diff[(i + 1) * stride + width - 1];
185
186 // Horizontal and vertical correlations for the penultimate col:
187 // Skip these on the last iteration of this loop if we also had two
188 // rows remaining, otherwise the final horizontal and vertical correlation
189 // get erroneously processed twice
190 if (i < height - 2 || height % 3 == 1) {
191 xy_sum += x * y;
192 xz_sum += x * z;
193 }
194
195 x_finalcol += w;
196 x2_finalcol += w * w;
197 // So the bottom-right elements don't get counted twice:
198 if (i < height - (height % 3 == 1 ? 2 : 3)) {
199 x_sum += z + w;
200 x2_sum += z * z + w * w;
201 }
202
203 // Now just vertical correlations for the final column:
204 xz_sum += y * w;
205 }
206 }
207
208 // Calculate the simple sums and squared-sums
209 int64_t x_firstrow = 0, x_firstcol = 0;
210 int64_t x2_firstrow = 0, x2_firstcol = 0;
211
212 for (int j = 0; j < width; ++j) {
213 x_firstrow += diff[j];
214 x2_firstrow += diff[j] * diff[j];
215 }
216 for (int i = 0; i < height; ++i) {
217 x_firstcol += diff[i * stride];
218 x2_firstcol += diff[i * stride] * diff[i * stride];
219 }
220
221 int64_t xhor_sum = x_sum - x_finalcol;
222 int64_t xver_sum = x_sum - x_finalrow;
223 int64_t y_sum = x_sum - x_firstcol;
224 int64_t z_sum = x_sum - x_firstrow;
225 int64_t x2hor_sum = x2_sum - x2_finalcol;
226 int64_t x2ver_sum = x2_sum - x2_finalrow;
227 int64_t y2_sum = x2_sum - x2_firstcol;
228 int64_t z2_sum = x2_sum - x2_firstrow;
229
230 const float num_hor = (float)(height * (width - 1));
231 const float num_ver = (float)((height - 1) * width);
232
233 const float xhor_var_n = x2hor_sum - (xhor_sum * xhor_sum) / num_hor;
234 const float xver_var_n = x2ver_sum - (xver_sum * xver_sum) / num_ver;
235
236 const float y_var_n = y2_sum - (y_sum * y_sum) / num_hor;
237 const float z_var_n = z2_sum - (z_sum * z_sum) / num_ver;
238
239 const float xy_var_n = xy_sum - (xhor_sum * y_sum) / num_hor;
240 const float xz_var_n = xz_sum - (xver_sum * z_sum) / num_ver;
241
242 if (xhor_var_n > 0 && y_var_n > 0) {
243 *hcorr = xy_var_n / sqrtf(xhor_var_n * y_var_n);
244 *hcorr = *hcorr < 0 ? 0 : *hcorr;
245 } else {
246 *hcorr = 1.0;
247 }
248 if (xver_var_n > 0 && z_var_n > 0) {
249 *vcorr = xz_var_n / sqrtf(xver_var_n * z_var_n);
250 *vcorr = *vcorr < 0 ? 0 : *vcorr;
251 } else {
252 *vcorr = 1.0;
253 }
254 }
255