aboutsummaryrefslogtreecommitdiff
path: root/src/core/NEON/kernels/NEGEMMLowpMatrixMultiplyKernel.cpp
blob: 3558c686b1f44fc08f2f5158b41b31d4648af743 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
/*
 * Copyright (c) 2016, 2017 ARM Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include "arm_compute/core/NEON/kernels/NEGEMMLowpMatrixMultiplyKernel.h"

#include "arm_compute/core/Error.h"
#include "arm_compute/core/Helpers.h"
#include "arm_compute/core/ITensor.h"
#include "arm_compute/core/TensorInfo.h"
#include "arm_compute/core/Types.h"
#include "arm_compute/core/Utils.h"
#include "arm_compute/core/Validate.h"
#include "arm_compute/core/Window.h"

#include <arm_neon.h>
#include <cstddef>
#include <cstdint>
#include <tuple>

using namespace arm_compute;

namespace arm_compute
{
class Coordinates;
} // namespace arm_compute

NEGEMMLowpMatrixMultiplyKernel::NEGEMMLowpMatrixMultiplyKernel()
    : _input0(nullptr), _input1(nullptr), _output(nullptr), _a_offset(0), _b_offset(0), _output_offset(0), _output_mult_int(0), _shift(0)
{
}

void NEGEMMLowpMatrixMultiplyKernel::configure(const ITensor *input0, const ITensor *input1, ITensor *output,
                                               int32_t a_offset, int32_t b_offset, int32_t output_offset, int32_t output_mult_int, int32_t shift)
{
    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input0, 1, DataType::U8);
    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input1, 1, DataType::U8);
    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(output, 1, DataType::U8);
    ARM_COMPUTE_ERROR_ON_MISMATCHING_DATA_TYPES(input0, input1, output);

    _input0          = input0;
    _input1          = input1;
    _output          = output;
    _a_offset        = a_offset;
    _b_offset        = b_offset;
    _output_offset   = output_offset;
    _output_mult_int = output_mult_int;
    _shift           = shift;

    constexpr unsigned int num_elems_processed_per_iteration_x = 16;
    constexpr unsigned int num_elems_processed_per_iteration_y = 4;

    Window win = calculate_max_window(*output->info(), Steps(num_elems_processed_per_iteration_x, num_elems_processed_per_iteration_y));

    AccessWindowRectangle  output_access(output->info(), 0, 0, num_elems_processed_per_iteration_x, num_elems_processed_per_iteration_y);
    AccessWindowHorizontal in0_access(input0->info(), 0, num_elems_processed_per_iteration_x);
    AccessWindowHorizontal in1_access(input1->info(), 0, num_elems_processed_per_iteration_x);

    update_window_and_padding(win, in0_access, in1_access, output_access);

    output_access.set_valid_region(win, ValidRegion(Coordinates(0, 0), output->info()->tensor_shape()));
    INEKernel::configure(win);
}

void NEGEMMLowpMatrixMultiplyKernel::run(const Window &window)
{
    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(INEKernel::window(), window);

    const size_t in_b_stride = _input1->info()->strides_in_bytes()[1];
    const size_t out_stride  = _output->info()->strides_in_bytes()[1];

    /* Set step_x and step_y for matrix A. Scale by a factor of 4 the Y range as the input interleaved matrix A has 4 times less the rows of the output matrix */
    Window win_a(window);
    win_a.set(Window::DimX, Window::Dimension(0, 0, 0));
    win_a.set(Window::DimY, Window::Dimension(window.y().start() >> 2, window.y().end() >> 2, 1));

    /* Set step_x and step_y for matrix B. Scale by a factor of 16 the X range as the input transposed matrix A has 16 times less the cols of the output matrix */
    Window win_b(window);
    win_b.set(Window::DimX, Window::Dimension(window.x().start() >> 4, window.x().end() >> 4, in_b_stride));
    win_b.set(Window::DimY, Window::Dimension(0, 0, 0));

    /* The step x and step y for the output matrix has been already set using in configure() */
    Iterator ina(_input0, win_a);
    Iterator inb(_input1, win_b);
    Iterator out(_output, window);

    const int32x4_t voffset_a = vdupq_n_s32(_a_offset);
    const int32x4_t voffset_b = vdupq_n_s32(_b_offset);
    const int32x4_t vshiftr   = vdupq_n_s32(-_shift);

    const int width_b = _input1->info()->dimension(0);

    // The implementation assumes that the matrix A and Matrix B have been reshaped respectively with NEGEMMInterleave4x4 and NEGEMMTranspose1xW
    // The reshaping of the matrices helps to have a cache friendly implementation and helps to avoid the data re-arrangements needed for computing 16x4 elements per iteration
    // All the values needed for computing a single 4x4 block will be read from consecutive memory positions
    execute_window_loop(window, [&](const Coordinates &)
    {
        const uint8_t *mtx_a0 = ina.ptr();
        const uint8_t *mtx_b0 = inb.ptr();

        // Accumulators for the block 0
        int32x4x4_t c0 =
        {
            {
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset)
            }
        };

        // Accumulators for the block 1
        int32x4x4_t c1 =
        {
            {
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset)
            }
        };

        // Accumulators for the block 2
        int32x4x4_t c2 =
        {
            {
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset)
            }
        };

        // Accumulators for the block 3
        int32x4x4_t c3 =
        {
            {
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset),
                vdupq_n_s32(_output_offset)
            }
        };

        int k = 0;
        // This for loop performs 4 accumulations per iteration
        for(; k <= (width_b - 64); k += 64, mtx_a0 += 16, mtx_b0 += 64)
        {
            const uint8x8_t p00  = vld1_u8(mtx_a0 + 0);
            const uint8x8_t p01  = vld1_u8(mtx_a0 + 8);
            const uint8x8_t q00l = vld1_u8(mtx_b0 + 0);
            const uint8x8_t q00h = vld1_u8(mtx_b0 + 8);
            const uint8x8_t q01l = vld1_u8(mtx_b0 + 16);
            const uint8x8_t q01h = vld1_u8(mtx_b0 + 24);
            const uint8x8_t q02l = vld1_u8(mtx_b0 + 32);
            const uint8x8_t q02h = vld1_u8(mtx_b0 + 40);
            const uint8x8_t q03l = vld1_u8(mtx_b0 + 48);
            const uint8x8_t q03h = vld1_u8(mtx_b0 + 56);

            const int32x4_t ia0l = vaddw_s16(voffset_a, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(p00))));
            const int32x4_t ia0h = vaddw_s16(voffset_a, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(p00))));
            const int32x4_t ia1l = vaddw_s16(voffset_a, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(p01))));
            const int32x4_t ia1h = vaddw_s16(voffset_a, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(p01))));

            const int32x2x4_t ia0 =
            {
                {
                    vget_low_s32(ia0l),
                    vget_high_s32(ia0l),
                    vget_low_s32(ia0h),
                    vget_high_s32(ia0h)
                }
            };

            const int32x2x4_t ia1 =
            {
                {
                    vget_low_s32(ia1l),
                    vget_high_s32(ia1l),
                    vget_low_s32(ia1h),
                    vget_high_s32(ia1h)
                }
            };

            const int32x4x4_t ib0 =
            {
                {
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q00l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q00l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q00h)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q00h))))
                }
            };

            const int32x4x4_t ib1 =
            {
                {
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q01l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q01l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q01h)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q01h))))
                }
            };

            const int32x4x4_t ib2 =
            {
                {
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q02l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q02l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q02h)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q02h))))
                }
            };

            const int32x4x4_t ib3 =
            {
                {
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q03l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q03l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q03h)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q03h))))
                }
            };

            // 4x4 block 0 - Accumulation 0
            c0.val[0] = vmlaq_lane_s32(c0.val[0], ib0.val[0], ia0.val[0], 0);
            c0.val[1] = vmlaq_lane_s32(c0.val[1], ib0.val[0], ia0.val[0], 1);
            c0.val[2] = vmlaq_lane_s32(c0.val[2], ib0.val[0], ia0.val[1], 0);
            c0.val[3] = vmlaq_lane_s32(c0.val[3], ib0.val[0], ia0.val[1], 1);
            // 4x4 block 0 - Accumulation 1
            c0.val[0] = vmlaq_lane_s32(c0.val[0], ib1.val[0], ia0.val[2], 0);
            c0.val[1] = vmlaq_lane_s32(c0.val[1], ib1.val[0], ia0.val[2], 1);
            c0.val[2] = vmlaq_lane_s32(c0.val[2], ib1.val[0], ia0.val[3], 0);
            c0.val[3] = vmlaq_lane_s32(c0.val[3], ib1.val[0], ia0.val[3], 1);
            // 4x4 block 0 - Accumulation 2
            c0.val[0] = vmlaq_lane_s32(c0.val[0], ib2.val[0], ia1.val[0], 0);
            c0.val[1] = vmlaq_lane_s32(c0.val[1], ib2.val[0], ia1.val[0], 1);
            c0.val[2] = vmlaq_lane_s32(c0.val[2], ib2.val[0], ia1.val[1], 0);
            c0.val[3] = vmlaq_lane_s32(c0.val[3], ib2.val[0], ia1.val[1], 1);
            // 4x4 block 0 - Accumulation 3
            c0.val[0] = vmlaq_lane_s32(c0.val[0], ib3.val[0], ia1.val[2], 0);
            c0.val[1] = vmlaq_lane_s32(c0.val[1], ib3.val[0], ia1.val[2], 1);
            c0.val[2] = vmlaq_lane_s32(c0.val[2], ib3.val[0], ia1.val[3], 0);
            c0.val[3] = vmlaq_lane_s32(c0.val[3], ib3.val[0], ia1.val[3], 1);

            // 4x4 block 1 - Accumulation 0
            c1.val[0] = vmlaq_lane_s32(c1.val[0], ib0.val[1], ia0.val[0], 0);
            c1.val[1] = vmlaq_lane_s32(c1.val[1], ib0.val[1], ia0.val[0], 1);
            c1.val[2] = vmlaq_lane_s32(c1.val[2], ib0.val[1], ia0.val[1], 0);
            c1.val[3] = vmlaq_lane_s32(c1.val[3], ib0.val[1], ia0.val[1], 1);
            // 4x4 block 1 - Accumulation 1
            c1.val[0] = vmlaq_lane_s32(c1.val[0], ib1.val[1], ia0.val[2], 0);
            c1.val[1] = vmlaq_lane_s32(c1.val[1], ib1.val[1], ia0.val[2], 1);
            c1.val[2] = vmlaq_lane_s32(c1.val[2], ib1.val[1], ia0.val[3], 0);
            c1.val[3] = vmlaq_lane_s32(c1.val[3], ib1.val[1], ia0.val[3], 1);
            // 4x4 block 1 - Accumulation 2
            c1.val[0] = vmlaq_lane_s32(c1.val[0], ib2.val[1], ia1.val[0], 0);
            c1.val[1] = vmlaq_lane_s32(c1.val[1], ib2.val[1], ia1.val[0], 1);
            c1.val[2] = vmlaq_lane_s32(c1.val[2], ib2.val[1], ia1.val[1], 0);
            c1.val[3] = vmlaq_lane_s32(c1.val[3], ib2.val[1], ia1.val[1], 1);
            // 4x4 block 1 - Accumulation 3
            c1.val[0] = vmlaq_lane_s32(c1.val[0], ib3.val[1], ia1.val[2], 0);
            c1.val[1] = vmlaq_lane_s32(c1.val[1], ib3.val[1], ia1.val[2], 1);
            c1.val[2] = vmlaq_lane_s32(c1.val[2], ib3.val[1], ia1.val[3], 0);
            c1.val[3] = vmlaq_lane_s32(c1.val[3], ib3.val[1], ia1.val[3], 1);

            // 4x4 block 2 - Accumulation 0
            c2.val[0] = vmlaq_lane_s32(c2.val[0], ib0.val[2], ia0.val[0], 0);
            c2.val[1] = vmlaq_lane_s32(c2.val[1], ib0.val[2], ia0.val[0], 1);
            c2.val[2] = vmlaq_lane_s32(c2.val[2], ib0.val[2], ia0.val[1], 0);
            c2.val[3] = vmlaq_lane_s32(c2.val[3], ib0.val[2], ia0.val[1], 1);
            // 4x4 block 2 - Accumulation 1
            c2.val[0] = vmlaq_lane_s32(c2.val[0], ib1.val[2], ia0.val[2], 0);
            c2.val[1] = vmlaq_lane_s32(c2.val[1], ib1.val[2], ia0.val[2], 1);
            c2.val[2] = vmlaq_lane_s32(c2.val[2], ib1.val[2], ia0.val[3], 0);
            c2.val[3] = vmlaq_lane_s32(c2.val[3], ib1.val[2], ia0.val[3], 1);
            // 4x4 block 2 - Accumulation 2
            c2.val[0] = vmlaq_lane_s32(c2.val[0], ib2.val[2], ia1.val[0], 0);
            c2.val[1] = vmlaq_lane_s32(c2.val[1], ib2.val[2], ia1.val[0], 1);
            c2.val[2] = vmlaq_lane_s32(c2.val[2], ib2.val[2], ia1.val[1], 0);
            c2.val[3] = vmlaq_lane_s32(c2.val[3], ib2.val[2], ia1.val[1], 1);
            // 4x4 block 2 - Accumulation 3
            c2.val[0] = vmlaq_lane_s32(c2.val[0], ib3.val[2], ia1.val[2], 0);
            c2.val[1] = vmlaq_lane_s32(c2.val[1], ib3.val[2], ia1.val[2], 1);
            c2.val[2] = vmlaq_lane_s32(c2.val[2], ib3.val[2], ia1.val[3], 0);
            c2.val[3] = vmlaq_lane_s32(c2.val[3], ib3.val[2], ia1.val[3], 1);

            // 4x4 block 3 - Accumulation 0
            c3.val[0] = vmlaq_lane_s32(c3.val[0], ib0.val[3], ia0.val[0], 0);
            c3.val[1] = vmlaq_lane_s32(c3.val[1], ib0.val[3], ia0.val[0], 1);
            c3.val[2] = vmlaq_lane_s32(c3.val[2], ib0.val[3], ia0.val[1], 0);
            c3.val[3] = vmlaq_lane_s32(c3.val[3], ib0.val[3], ia0.val[1], 1);
            // 4x4 block 3 - Accumulation 1
            c3.val[0] = vmlaq_lane_s32(c3.val[0], ib1.val[3], ia0.val[2], 0);
            c3.val[1] = vmlaq_lane_s32(c3.val[1], ib1.val[3], ia0.val[2], 1);
            c3.val[2] = vmlaq_lane_s32(c3.val[2], ib1.val[3], ia0.val[3], 0);
            c3.val[3] = vmlaq_lane_s32(c3.val[3], ib1.val[3], ia0.val[3], 1);
            // 4x4 block 3 - Accumulation 2
            c3.val[0] = vmlaq_lane_s32(c3.val[0], ib2.val[3], ia1.val[0], 0);
            c3.val[1] = vmlaq_lane_s32(c3.val[1], ib2.val[3], ia1.val[0], 1);
            c3.val[2] = vmlaq_lane_s32(c3.val[2], ib2.val[3], ia1.val[1], 0);
            c3.val[3] = vmlaq_lane_s32(c3.val[3], ib2.val[3], ia1.val[1], 1);
            // 4x4 block 3 - Accumulation 3
            c3.val[0] = vmlaq_lane_s32(c3.val[0], ib3.val[3], ia1.val[2], 0);
            c3.val[1] = vmlaq_lane_s32(c3.val[1], ib3.val[3], ia1.val[2], 1);
            c3.val[2] = vmlaq_lane_s32(c3.val[2], ib3.val[3], ia1.val[3], 0);
            c3.val[3] = vmlaq_lane_s32(c3.val[3], ib3.val[3], ia1.val[3], 1);
        }

        // This for loop handles the left-over accumulations
        for(; k < width_b; k += 16, mtx_a0 += 4, mtx_b0 += 16)
        {
            const uint8x8_t p00  = vld1_u8(mtx_a0);
            const uint8x8_t q00l = vld1_u8(mtx_b0);
            const uint8x8_t q00h = vld1_u8(mtx_b0 + 8);

            const int32x4_t ia0 = vaddw_s16(voffset_a, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(p00))));

            const int32x2x2_t ia =
            {
                {
                    vget_low_s32(ia0),
                    vget_high_s32(ia0)
                }
            };

            const int32x4x4_t ib0 =
            {
                {
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q00l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q00l)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_low_u16(vmovl_u8(q00h)))),
                    vaddw_s16(voffset_b, vreinterpret_s16_u16(vget_high_u16(vmovl_u8(q00h))))
                }
            };

            // 4x4 block 0
            c0.val[0] = vmlaq_lane_s32(c0.val[0], ib0.val[0], ia.val[0], 0);
            c0.val[1] = vmlaq_lane_s32(c0.val[1], ib0.val[0], ia.val[0], 1);
            c0.val[2] = vmlaq_lane_s32(c0.val[2], ib0.val[0], ia.val[1], 0);
            c0.val[3] = vmlaq_lane_s32(c0.val[3], ib0.val[0], ia.val[1], 1);

            // 4x4 block 1
            c1.val[0] = vmlaq_lane_s32(c1.val[0], ib0.val[1], ia.val[0], 0);
            c1.val[1] = vmlaq_lane_s32(c1.val[1], ib0.val[1], ia.val[0], 1);
            c1.val[2] = vmlaq_lane_s32(c1.val[2], ib0.val[1], ia.val[1], 0);
            c1.val[3] = vmlaq_lane_s32(c1.val[3], ib0.val[1], ia.val[1], 1);

            // 4x4 block 2
            c2.val[0] = vmlaq_lane_s32(c2.val[0], ib0.val[2], ia.val[0], 0);
            c2.val[1] = vmlaq_lane_s32(c2.val[1], ib0.val[2], ia.val[0], 1);
            c2.val[2] = vmlaq_lane_s32(c2.val[2], ib0.val[2], ia.val[1], 0);
            c2.val[3] = vmlaq_lane_s32(c2.val[3], ib0.val[2], ia.val[1], 1);

            // 4x4 block 3
            c3.val[0] = vmlaq_lane_s32(c3.val[0], ib0.val[3], ia.val[0], 0);
            c3.val[1] = vmlaq_lane_s32(c3.val[1], ib0.val[3], ia.val[0], 1);
            c3.val[2] = vmlaq_lane_s32(c3.val[2], ib0.val[3], ia.val[1], 0);
            c3.val[3] = vmlaq_lane_s32(c3.val[3], ib0.val[3], ia.val[1], 1);
        }

        c0.val[0] = vshlq_s32(vmulq_n_s32(c0.val[0], _output_mult_int), vshiftr);
        c0.val[1] = vshlq_s32(vmulq_n_s32(c0.val[1], _output_mult_int), vshiftr);
        c0.val[2] = vshlq_s32(vmulq_n_s32(c0.val[2], _output_mult_int), vshiftr);
        c0.val[3] = vshlq_s32(vmulq_n_s32(c0.val[3], _output_mult_int), vshiftr);

        c1.val[0] = vshlq_s32(vmulq_n_s32(c1.val[0], _output_mult_int), vshiftr);
        c1.val[1] = vshlq_s32(vmulq_n_s32(c1.val[1], _output_mult_int), vshiftr);
        c1.val[2] = vshlq_s32(vmulq_n_s32(c1.val[2], _output_mult_int), vshiftr);
        c1.val[3] = vshlq_s32(vmulq_n_s32(c1.val[3], _output_mult_int), vshiftr);

        c2.val[0] = vshlq_s32(vmulq_n_s32(c2.val[0], _output_mult_int), vshiftr);
        c2.val[1] = vshlq_s32(vmulq_n_s32(c2.val[1], _output_mult_int), vshiftr);
        c2.val[2] = vshlq_s32(vmulq_n_s32(c2.val[2], _output_mult_int), vshiftr);
        c2.val[3] = vshlq_s32(vmulq_n_s32(c2.val[3], _output_mult_int), vshiftr);

        c3.val[0] = vshlq_s32(vmulq_n_s32(c3.val[0], _output_mult_int), vshiftr);
        c3.val[1] = vshlq_s32(vmulq_n_s32(c3.val[1], _output_mult_int), vshiftr);
        c3.val[2] = vshlq_s32(vmulq_n_s32(c3.val[2], _output_mult_int), vshiftr);
        c3.val[3] = vshlq_s32(vmulq_n_s32(c3.val[3], _output_mult_int), vshiftr);

        const uint8x16x4_t r =
        {
            {
                vcombine_u8(vqmovun_s16(vcombine_s16(vqmovn_s32(c0.val[0]), vqmovn_s32(c1.val[0]))),
                vqmovun_s16(vcombine_s16(vqmovn_s32(c2.val[0]), vqmovn_s32(c3.val[0])))),
                vcombine_u8(vqmovun_s16(vcombine_s16(vqmovn_s32(c0.val[1]), vqmovn_s32(c1.val[1]))),
                vqmovun_s16(vcombine_s16(vqmovn_s32(c2.val[1]), vqmovn_s32(c3.val[1])))),
                vcombine_u8(vqmovun_s16(vcombine_s16(vqmovn_s32(c0.val[2]), vqmovn_s32(c1.val[2]))),
                vqmovun_s16(vcombine_s16(vqmovn_s32(c2.val[2]), vqmovn_s32(c3.val[2])))),
                vcombine_u8(vqmovun_s16(vcombine_s16(vqmovn_s32(c0.val[3]), vqmovn_s32(c1.val[3]))),
                vqmovun_s16(vcombine_s16(vqmovn_s32(c2.val[3]), vqmovn_s32(c3.val[3]))))
            }
        };

        uint8_t *const mtx_out = out.ptr();
        vst1q_u8(mtx_out + 0 * out_stride, r.val[0]);
        vst1q_u8(mtx_out + 1 * out_stride, r.val[1]);
        vst1q_u8(mtx_out + 2 * out_stride, r.val[2]);
        vst1q_u8(mtx_out + 3 * out_stride, r.val[3]);
    },
    ina, inb, out);
}