1/*
2 *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include <arm_neon.h>
12#include <assert.h>
13
14#include "./vpx_dsp_rtcd.h"
15#include "./vpx_config.h"
16
17#include "vpx/vpx_integer.h"
18#include "vpx_dsp/arm/mem_neon.h"
19#include "vpx_dsp/arm/sum_neon.h"
20#include "vpx_ports/mem.h"
21
22// The variance helper functions use int16_t for sum. 8 values are accumulated
23// and then added (at which point they expand up to int32_t). To avoid overflow,
24// there can be no more than 32767 / 255 ~= 128 values accumulated in each
25// column. For a 32x32 buffer, this results in 32 / 8 = 4 values per row * 32
26// rows = 128. Asserts have been added to each function to warn against reaching
27// this limit.
28
29// Process a block of width 4 four rows at a time.
30static void variance_neon_w4x4(const uint8_t *a, int a_stride, const uint8_t *b,
31                               int b_stride, int h, uint32_t *sse, int *sum) {
32  int i;
33  int16x8_t sum_s16 = vdupq_n_s16(0);
34  int32x4_t sse_lo_s32 = vdupq_n_s32(0);
35  int32x4_t sse_hi_s32 = vdupq_n_s32(0);
36
37  // Since width is only 4, sum_s16 only loads a half row per loop.
38  assert(h <= 256);
39
40  for (i = 0; i < h; i += 4) {
41    const uint8x16_t a_u8 = load_unaligned_u8q(a, a_stride);
42    const uint8x16_t b_u8 = load_unaligned_u8q(b, b_stride);
43    const uint16x8_t diff_lo_u16 =
44        vsubl_u8(vget_low_u8(a_u8), vget_low_u8(b_u8));
45    const uint16x8_t diff_hi_u16 =
46        vsubl_u8(vget_high_u8(a_u8), vget_high_u8(b_u8));
47
48    const int16x8_t diff_lo_s16 = vreinterpretq_s16_u16(diff_lo_u16);
49    const int16x8_t diff_hi_s16 = vreinterpretq_s16_u16(diff_hi_u16);
50
51    sum_s16 = vaddq_s16(sum_s16, diff_lo_s16);
52    sum_s16 = vaddq_s16(sum_s16, diff_hi_s16);
53
54    sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_low_s16(diff_lo_s16),
55                           vget_low_s16(diff_lo_s16));
56    sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_high_s16(diff_lo_s16),
57                           vget_high_s16(diff_lo_s16));
58
59    sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_low_s16(diff_hi_s16),
60                           vget_low_s16(diff_hi_s16));
61    sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_high_s16(diff_hi_s16),
62                           vget_high_s16(diff_hi_s16));
63
64    a += 4 * a_stride;
65    b += 4 * b_stride;
66  }
67
68  *sum = vget_lane_s32(horizontal_add_int16x8(sum_s16), 0);
69  *sse = vget_lane_u32(horizontal_add_uint32x4(vreinterpretq_u32_s32(
70                           vaddq_s32(sse_lo_s32, sse_hi_s32))),
71                       0);
72}
73
74// Process a block of any size where the width is divisible by 16.
75static void variance_neon_w16(const uint8_t *a, int a_stride, const uint8_t *b,
76                              int b_stride, int w, int h, uint32_t *sse,
77                              int *sum) {
78  int i, j;
79  int16x8_t sum_s16 = vdupq_n_s16(0);
80  int32x4_t sse_lo_s32 = vdupq_n_s32(0);
81  int32x4_t sse_hi_s32 = vdupq_n_s32(0);
82
83  // The loop loads 16 values at a time but doubles them up when accumulating
84  // into sum_s16.
85  assert(w / 8 * h <= 128);
86
87  for (i = 0; i < h; ++i) {
88    for (j = 0; j < w; j += 16) {
89      const uint8x16_t a_u8 = vld1q_u8(a + j);
90      const uint8x16_t b_u8 = vld1q_u8(b + j);
91
92      const uint16x8_t diff_lo_u16 =
93          vsubl_u8(vget_low_u8(a_u8), vget_low_u8(b_u8));
94      const uint16x8_t diff_hi_u16 =
95          vsubl_u8(vget_high_u8(a_u8), vget_high_u8(b_u8));
96
97      const int16x8_t diff_lo_s16 = vreinterpretq_s16_u16(diff_lo_u16);
98      const int16x8_t diff_hi_s16 = vreinterpretq_s16_u16(diff_hi_u16);
99
100      sum_s16 = vaddq_s16(sum_s16, diff_lo_s16);
101      sum_s16 = vaddq_s16(sum_s16, diff_hi_s16);
102
103      sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_low_s16(diff_lo_s16),
104                             vget_low_s16(diff_lo_s16));
105      sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_high_s16(diff_lo_s16),
106                             vget_high_s16(diff_lo_s16));
107
108      sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_low_s16(diff_hi_s16),
109                             vget_low_s16(diff_hi_s16));
110      sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_high_s16(diff_hi_s16),
111                             vget_high_s16(diff_hi_s16));
112    }
113    a += a_stride;
114    b += b_stride;
115  }
116
117  *sum = vget_lane_s32(horizontal_add_int16x8(sum_s16), 0);
118  *sse = vget_lane_u32(horizontal_add_uint32x4(vreinterpretq_u32_s32(
119                           vaddq_s32(sse_lo_s32, sse_hi_s32))),
120                       0);
121}
122
123// Process a block of width 8 two rows at a time.
124static void variance_neon_w8x2(const uint8_t *a, int a_stride, const uint8_t *b,
125                               int b_stride, int h, uint32_t *sse, int *sum) {
126  int i = 0;
127  int16x8_t sum_s16 = vdupq_n_s16(0);
128  int32x4_t sse_lo_s32 = vdupq_n_s32(0);
129  int32x4_t sse_hi_s32 = vdupq_n_s32(0);
130
131  // Each column has it's own accumulator entry in sum_s16.
132  assert(h <= 128);
133
134  do {
135    const uint8x8_t a_0_u8 = vld1_u8(a);
136    const uint8x8_t a_1_u8 = vld1_u8(a + a_stride);
137    const uint8x8_t b_0_u8 = vld1_u8(b);
138    const uint8x8_t b_1_u8 = vld1_u8(b + b_stride);
139    const uint16x8_t diff_0_u16 = vsubl_u8(a_0_u8, b_0_u8);
140    const uint16x8_t diff_1_u16 = vsubl_u8(a_1_u8, b_1_u8);
141    const int16x8_t diff_0_s16 = vreinterpretq_s16_u16(diff_0_u16);
142    const int16x8_t diff_1_s16 = vreinterpretq_s16_u16(diff_1_u16);
143    sum_s16 = vaddq_s16(sum_s16, diff_0_s16);
144    sum_s16 = vaddq_s16(sum_s16, diff_1_s16);
145    sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_low_s16(diff_0_s16),
146                           vget_low_s16(diff_0_s16));
147    sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_low_s16(diff_1_s16),
148                           vget_low_s16(diff_1_s16));
149    sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_high_s16(diff_0_s16),
150                           vget_high_s16(diff_0_s16));
151    sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_high_s16(diff_1_s16),
152                           vget_high_s16(diff_1_s16));
153    a += a_stride + a_stride;
154    b += b_stride + b_stride;
155    i += 2;
156  } while (i < h);
157
158  *sum = vget_lane_s32(horizontal_add_int16x8(sum_s16), 0);
159  *sse = vget_lane_u32(horizontal_add_uint32x4(vreinterpretq_u32_s32(
160                           vaddq_s32(sse_lo_s32, sse_hi_s32))),
161                       0);
162}
163
164void vpx_get8x8var_neon(const uint8_t *a, int a_stride, const uint8_t *b,
165                        int b_stride, unsigned int *sse, int *sum) {
166  variance_neon_w8x2(a, a_stride, b, b_stride, 8, sse, sum);
167}
168
169void vpx_get16x16var_neon(const uint8_t *a, int a_stride, const uint8_t *b,
170                          int b_stride, unsigned int *sse, int *sum) {
171  variance_neon_w16(a, a_stride, b, b_stride, 16, 16, sse, sum);
172}
173
174#define varianceNxM(n, m, shift)                                            \
175  unsigned int vpx_variance##n##x##m##_neon(const uint8_t *a, int a_stride, \
176                                            const uint8_t *b, int b_stride, \
177                                            unsigned int *sse) {            \
178    int sum;                                                                \
179    if (n == 4)                                                             \
180      variance_neon_w4x4(a, a_stride, b, b_stride, m, sse, &sum);           \
181    else if (n == 8)                                                        \
182      variance_neon_w8x2(a, a_stride, b, b_stride, m, sse, &sum);           \
183    else                                                                    \
184      variance_neon_w16(a, a_stride, b, b_stride, n, m, sse, &sum);         \
185    if (n * m < 16 * 16)                                                    \
186      return *sse - ((sum * sum) >> shift);                                 \
187    else                                                                    \
188      return *sse - (uint32_t)(((int64_t)sum * sum) >> shift);              \
189  }
190
191varianceNxM(4, 4, 4);
192varianceNxM(4, 8, 5);
193varianceNxM(8, 4, 5);
194varianceNxM(8, 8, 6);
195varianceNxM(8, 16, 7);
196varianceNxM(16, 8, 7);
197varianceNxM(16, 16, 8);
198varianceNxM(16, 32, 9);
199varianceNxM(32, 16, 9);
200varianceNxM(32, 32, 10);
201
202unsigned int vpx_variance32x64_neon(const uint8_t *a, int a_stride,
203                                    const uint8_t *b, int b_stride,
204                                    unsigned int *sse) {
205  int sum1, sum2;
206  uint32_t sse1, sse2;
207  variance_neon_w16(a, a_stride, b, b_stride, 32, 32, &sse1, &sum1);
208  variance_neon_w16(a + (32 * a_stride), a_stride, b + (32 * b_stride),
209                    b_stride, 32, 32, &sse2, &sum2);
210  *sse = sse1 + sse2;
211  sum1 += sum2;
212  return *sse - (unsigned int)(((int64_t)sum1 * sum1) >> 11);
213}
214
215unsigned int vpx_variance64x32_neon(const uint8_t *a, int a_stride,
216                                    const uint8_t *b, int b_stride,
217                                    unsigned int *sse) {
218  int sum1, sum2;
219  uint32_t sse1, sse2;
220  variance_neon_w16(a, a_stride, b, b_stride, 64, 16, &sse1, &sum1);
221  variance_neon_w16(a + (16 * a_stride), a_stride, b + (16 * b_stride),
222                    b_stride, 64, 16, &sse2, &sum2);
223  *sse = sse1 + sse2;
224  sum1 += sum2;
225  return *sse - (unsigned int)(((int64_t)sum1 * sum1) >> 11);
226}
227
228unsigned int vpx_variance64x64_neon(const uint8_t *a, int a_stride,
229                                    const uint8_t *b, int b_stride,
230                                    unsigned int *sse) {
231  int sum1, sum2;
232  uint32_t sse1, sse2;
233
234  variance_neon_w16(a, a_stride, b, b_stride, 64, 16, &sse1, &sum1);
235  variance_neon_w16(a + (16 * a_stride), a_stride, b + (16 * b_stride),
236                    b_stride, 64, 16, &sse2, &sum2);
237  sse1 += sse2;
238  sum1 += sum2;
239
240  variance_neon_w16(a + (16 * 2 * a_stride), a_stride, b + (16 * 2 * b_stride),
241                    b_stride, 64, 16, &sse2, &sum2);
242  sse1 += sse2;
243  sum1 += sum2;
244
245  variance_neon_w16(a + (16 * 3 * a_stride), a_stride, b + (16 * 3 * b_stride),
246                    b_stride, 64, 16, &sse2, &sum2);
247  *sse = sse1 + sse2;
248  sum1 += sum2;
249  return *sse - (unsigned int)(((int64_t)sum1 * sum1) >> 12);
250}
251
252unsigned int vpx_mse16x16_neon(const unsigned char *src_ptr, int source_stride,
253                               const unsigned char *ref_ptr, int recon_stride,
254                               unsigned int *sse) {
255  int i;
256  int16x4_t d22s16, d23s16, d24s16, d25s16, d26s16, d27s16, d28s16, d29s16;
257  int64x1_t d0s64;
258  uint8x16_t q0u8, q1u8, q2u8, q3u8;
259  int32x4_t q7s32, q8s32, q9s32, q10s32;
260  uint16x8_t q11u16, q12u16, q13u16, q14u16;
261  int64x2_t q1s64;
262
263  q7s32 = vdupq_n_s32(0);
264  q8s32 = vdupq_n_s32(0);
265  q9s32 = vdupq_n_s32(0);
266  q10s32 = vdupq_n_s32(0);
267
268  for (i = 0; i < 8; i++) {  // mse16x16_neon_loop
269    q0u8 = vld1q_u8(src_ptr);
270    src_ptr += source_stride;
271    q1u8 = vld1q_u8(src_ptr);
272    src_ptr += source_stride;
273    q2u8 = vld1q_u8(ref_ptr);
274    ref_ptr += recon_stride;
275    q3u8 = vld1q_u8(ref_ptr);
276    ref_ptr += recon_stride;
277
278    q11u16 = vsubl_u8(vget_low_u8(q0u8), vget_low_u8(q2u8));
279    q12u16 = vsubl_u8(vget_high_u8(q0u8), vget_high_u8(q2u8));
280    q13u16 = vsubl_u8(vget_low_u8(q1u8), vget_low_u8(q3u8));
281    q14u16 = vsubl_u8(vget_high_u8(q1u8), vget_high_u8(q3u8));
282
283    d22s16 = vreinterpret_s16_u16(vget_low_u16(q11u16));
284    d23s16 = vreinterpret_s16_u16(vget_high_u16(q11u16));
285    q7s32 = vmlal_s16(q7s32, d22s16, d22s16);
286    q8s32 = vmlal_s16(q8s32, d23s16, d23s16);
287
288    d24s16 = vreinterpret_s16_u16(vget_low_u16(q12u16));
289    d25s16 = vreinterpret_s16_u16(vget_high_u16(q12u16));
290    q9s32 = vmlal_s16(q9s32, d24s16, d24s16);
291    q10s32 = vmlal_s16(q10s32, d25s16, d25s16);
292
293    d26s16 = vreinterpret_s16_u16(vget_low_u16(q13u16));
294    d27s16 = vreinterpret_s16_u16(vget_high_u16(q13u16));
295    q7s32 = vmlal_s16(q7s32, d26s16, d26s16);
296    q8s32 = vmlal_s16(q8s32, d27s16, d27s16);
297
298    d28s16 = vreinterpret_s16_u16(vget_low_u16(q14u16));
299    d29s16 = vreinterpret_s16_u16(vget_high_u16(q14u16));
300    q9s32 = vmlal_s16(q9s32, d28s16, d28s16);
301    q10s32 = vmlal_s16(q10s32, d29s16, d29s16);
302  }
303
304  q7s32 = vaddq_s32(q7s32, q8s32);
305  q9s32 = vaddq_s32(q9s32, q10s32);
306  q10s32 = vaddq_s32(q7s32, q9s32);
307
308  q1s64 = vpaddlq_s32(q10s32);
309  d0s64 = vadd_s64(vget_low_s64(q1s64), vget_high_s64(q1s64));
310
311  vst1_lane_u32((uint32_t *)sse, vreinterpret_u32_s64(d0s64), 0);
312  return vget_lane_u32(vreinterpret_u32_s64(d0s64), 0);
313}
314
315unsigned int vpx_get4x4sse_cs_neon(const unsigned char *src_ptr,
316                                   int source_stride,
317                                   const unsigned char *ref_ptr,
318                                   int recon_stride) {
319  int16x4_t d22s16, d24s16, d26s16, d28s16;
320  int64x1_t d0s64;
321  uint8x8_t d0u8, d1u8, d2u8, d3u8, d4u8, d5u8, d6u8, d7u8;
322  int32x4_t q7s32, q8s32, q9s32, q10s32;
323  uint16x8_t q11u16, q12u16, q13u16, q14u16;
324  int64x2_t q1s64;
325
326  d0u8 = vld1_u8(src_ptr);
327  src_ptr += source_stride;
328  d4u8 = vld1_u8(ref_ptr);
329  ref_ptr += recon_stride;
330  d1u8 = vld1_u8(src_ptr);
331  src_ptr += source_stride;
332  d5u8 = vld1_u8(ref_ptr);
333  ref_ptr += recon_stride;
334  d2u8 = vld1_u8(src_ptr);
335  src_ptr += source_stride;
336  d6u8 = vld1_u8(ref_ptr);
337  ref_ptr += recon_stride;
338  d3u8 = vld1_u8(src_ptr);
339  src_ptr += source_stride;
340  d7u8 = vld1_u8(ref_ptr);
341  ref_ptr += recon_stride;
342
343  q11u16 = vsubl_u8(d0u8, d4u8);
344  q12u16 = vsubl_u8(d1u8, d5u8);
345  q13u16 = vsubl_u8(d2u8, d6u8);
346  q14u16 = vsubl_u8(d3u8, d7u8);
347
348  d22s16 = vget_low_s16(vreinterpretq_s16_u16(q11u16));
349  d24s16 = vget_low_s16(vreinterpretq_s16_u16(q12u16));
350  d26s16 = vget_low_s16(vreinterpretq_s16_u16(q13u16));
351  d28s16 = vget_low_s16(vreinterpretq_s16_u16(q14u16));
352
353  q7s32 = vmull_s16(d22s16, d22s16);
354  q8s32 = vmull_s16(d24s16, d24s16);
355  q9s32 = vmull_s16(d26s16, d26s16);
356  q10s32 = vmull_s16(d28s16, d28s16);
357
358  q7s32 = vaddq_s32(q7s32, q8s32);
359  q9s32 = vaddq_s32(q9s32, q10s32);
360  q9s32 = vaddq_s32(q7s32, q9s32);
361
362  q1s64 = vpaddlq_s32(q9s32);
363  d0s64 = vadd_s64(vget_low_s64(q1s64), vget_high_s64(q1s64));
364
365  return vget_lane_u32(vreinterpret_u32_s64(d0s64), 0);
366}
367