1 /*
2 * Copyright (c) 2017 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
13 #include "./vpx_config.h"
14 #include "./vpx_dsp_rtcd.h"
15 #include "vpx_dsp/txfm_common.h"
16 #include "vpx_dsp/arm/mem_neon.h"
17 #include "vpx_dsp/arm/transpose_neon.h"
18
19 // Some builds of gcc 4.9.2 and .3 have trouble with some of the inline
20 // functions.
21 #if !defined(__clang__) && !defined(__ANDROID__) && defined(__GNUC__) && \
22 __GNUC__ == 4 && __GNUC_MINOR__ == 9 && __GNUC_PATCHLEVEL__ < 4
23
vpx_fdct16x16_neon(const int16_t * input,tran_low_t * output,int stride)24 void vpx_fdct16x16_neon(const int16_t *input, tran_low_t *output, int stride) {
25 vpx_fdct16x16_c(input, output, stride);
26 }
27
28 #else
29
load(const int16_t * a,int stride,int16x8_t * b)30 static INLINE void load(const int16_t *a, int stride, int16x8_t *b /*[16]*/) {
31 b[0] = vld1q_s16(a);
32 a += stride;
33 b[1] = vld1q_s16(a);
34 a += stride;
35 b[2] = vld1q_s16(a);
36 a += stride;
37 b[3] = vld1q_s16(a);
38 a += stride;
39 b[4] = vld1q_s16(a);
40 a += stride;
41 b[5] = vld1q_s16(a);
42 a += stride;
43 b[6] = vld1q_s16(a);
44 a += stride;
45 b[7] = vld1q_s16(a);
46 a += stride;
47 b[8] = vld1q_s16(a);
48 a += stride;
49 b[9] = vld1q_s16(a);
50 a += stride;
51 b[10] = vld1q_s16(a);
52 a += stride;
53 b[11] = vld1q_s16(a);
54 a += stride;
55 b[12] = vld1q_s16(a);
56 a += stride;
57 b[13] = vld1q_s16(a);
58 a += stride;
59 b[14] = vld1q_s16(a);
60 a += stride;
61 b[15] = vld1q_s16(a);
62 }
63
64 // Store 8 16x8 values, assuming stride == 16.
store(tran_low_t * a,const int16x8_t * b)65 static INLINE void store(tran_low_t *a, const int16x8_t *b /*[8]*/) {
66 store_s16q_to_tran_low(a, b[0]);
67 a += 16;
68 store_s16q_to_tran_low(a, b[1]);
69 a += 16;
70 store_s16q_to_tran_low(a, b[2]);
71 a += 16;
72 store_s16q_to_tran_low(a, b[3]);
73 a += 16;
74 store_s16q_to_tran_low(a, b[4]);
75 a += 16;
76 store_s16q_to_tran_low(a, b[5]);
77 a += 16;
78 store_s16q_to_tran_low(a, b[6]);
79 a += 16;
80 store_s16q_to_tran_low(a, b[7]);
81 }
82
83 // Load step of each pass. Add and subtract clear across the input, requiring
84 // all 16 values to be loaded. For the first pass it also multiplies by 4.
85
86 // To maybe reduce register usage this could be combined with the load() step to
87 // get the first 4 and last 4 values, cross those, then load the middle 8 values
88 // and cross them.
cross_input(const int16x8_t * a,int16x8_t * b,const int pass)89 static INLINE void cross_input(const int16x8_t *a /*[16]*/,
90 int16x8_t *b /*[16]*/, const int pass) {
91 if (pass == 0) {
92 b[0] = vshlq_n_s16(vaddq_s16(a[0], a[15]), 2);
93 b[1] = vshlq_n_s16(vaddq_s16(a[1], a[14]), 2);
94 b[2] = vshlq_n_s16(vaddq_s16(a[2], a[13]), 2);
95 b[3] = vshlq_n_s16(vaddq_s16(a[3], a[12]), 2);
96 b[4] = vshlq_n_s16(vaddq_s16(a[4], a[11]), 2);
97 b[5] = vshlq_n_s16(vaddq_s16(a[5], a[10]), 2);
98 b[6] = vshlq_n_s16(vaddq_s16(a[6], a[9]), 2);
99 b[7] = vshlq_n_s16(vaddq_s16(a[7], a[8]), 2);
100
101 b[8] = vshlq_n_s16(vsubq_s16(a[7], a[8]), 2);
102 b[9] = vshlq_n_s16(vsubq_s16(a[6], a[9]), 2);
103 b[10] = vshlq_n_s16(vsubq_s16(a[5], a[10]), 2);
104 b[11] = vshlq_n_s16(vsubq_s16(a[4], a[11]), 2);
105 b[12] = vshlq_n_s16(vsubq_s16(a[3], a[12]), 2);
106 b[13] = vshlq_n_s16(vsubq_s16(a[2], a[13]), 2);
107 b[14] = vshlq_n_s16(vsubq_s16(a[1], a[14]), 2);
108 b[15] = vshlq_n_s16(vsubq_s16(a[0], a[15]), 2);
109 } else {
110 b[0] = vaddq_s16(a[0], a[15]);
111 b[1] = vaddq_s16(a[1], a[14]);
112 b[2] = vaddq_s16(a[2], a[13]);
113 b[3] = vaddq_s16(a[3], a[12]);
114 b[4] = vaddq_s16(a[4], a[11]);
115 b[5] = vaddq_s16(a[5], a[10]);
116 b[6] = vaddq_s16(a[6], a[9]);
117 b[7] = vaddq_s16(a[7], a[8]);
118
119 b[8] = vsubq_s16(a[7], a[8]);
120 b[9] = vsubq_s16(a[6], a[9]);
121 b[10] = vsubq_s16(a[5], a[10]);
122 b[11] = vsubq_s16(a[4], a[11]);
123 b[12] = vsubq_s16(a[3], a[12]);
124 b[13] = vsubq_s16(a[2], a[13]);
125 b[14] = vsubq_s16(a[1], a[14]);
126 b[15] = vsubq_s16(a[0], a[15]);
127 }
128 }
129
130 // Quarter round at the beginning of the second pass. Can't use vrshr (rounding)
131 // because this only adds 1, not 1 << 2.
partial_round_shift(int16x8_t * a)132 static INLINE void partial_round_shift(int16x8_t *a /*[16]*/) {
133 const int16x8_t one = vdupq_n_s16(1);
134 a[0] = vshrq_n_s16(vaddq_s16(a[0], one), 2);
135 a[1] = vshrq_n_s16(vaddq_s16(a[1], one), 2);
136 a[2] = vshrq_n_s16(vaddq_s16(a[2], one), 2);
137 a[3] = vshrq_n_s16(vaddq_s16(a[3], one), 2);
138 a[4] = vshrq_n_s16(vaddq_s16(a[4], one), 2);
139 a[5] = vshrq_n_s16(vaddq_s16(a[5], one), 2);
140 a[6] = vshrq_n_s16(vaddq_s16(a[6], one), 2);
141 a[7] = vshrq_n_s16(vaddq_s16(a[7], one), 2);
142 a[8] = vshrq_n_s16(vaddq_s16(a[8], one), 2);
143 a[9] = vshrq_n_s16(vaddq_s16(a[9], one), 2);
144 a[10] = vshrq_n_s16(vaddq_s16(a[10], one), 2);
145 a[11] = vshrq_n_s16(vaddq_s16(a[11], one), 2);
146 a[12] = vshrq_n_s16(vaddq_s16(a[12], one), 2);
147 a[13] = vshrq_n_s16(vaddq_s16(a[13], one), 2);
148 a[14] = vshrq_n_s16(vaddq_s16(a[14], one), 2);
149 a[15] = vshrq_n_s16(vaddq_s16(a[15], one), 2);
150 }
151
152 // fdct_round_shift((a +/- b) * c)
butterfly_one_coeff(const int16x8_t a,const int16x8_t b,const tran_high_t c,int16x8_t * add,int16x8_t * sub)153 static INLINE void butterfly_one_coeff(const int16x8_t a, const int16x8_t b,
154 const tran_high_t c, int16x8_t *add,
155 int16x8_t *sub) {
156 const int32x4_t a0 = vmull_n_s16(vget_low_s16(a), c);
157 const int32x4_t a1 = vmull_n_s16(vget_high_s16(a), c);
158 const int32x4_t sum0 = vmlal_n_s16(a0, vget_low_s16(b), c);
159 const int32x4_t sum1 = vmlal_n_s16(a1, vget_high_s16(b), c);
160 const int32x4_t diff0 = vmlsl_n_s16(a0, vget_low_s16(b), c);
161 const int32x4_t diff1 = vmlsl_n_s16(a1, vget_high_s16(b), c);
162 const int16x4_t rounded0 = vqrshrn_n_s32(sum0, 14);
163 const int16x4_t rounded1 = vqrshrn_n_s32(sum1, 14);
164 const int16x4_t rounded2 = vqrshrn_n_s32(diff0, 14);
165 const int16x4_t rounded3 = vqrshrn_n_s32(diff1, 14);
166 *add = vcombine_s16(rounded0, rounded1);
167 *sub = vcombine_s16(rounded2, rounded3);
168 }
169
170 // fdct_round_shift(a * c0 +/- b * c1)
butterfly_two_coeff(const int16x8_t a,const int16x8_t b,const tran_coef_t c0,const tran_coef_t c1,int16x8_t * add,int16x8_t * sub)171 static INLINE void butterfly_two_coeff(const int16x8_t a, const int16x8_t b,
172 const tran_coef_t c0,
173 const tran_coef_t c1, int16x8_t *add,
174 int16x8_t *sub) {
175 const int32x4_t a0 = vmull_n_s16(vget_low_s16(a), c0);
176 const int32x4_t a1 = vmull_n_s16(vget_high_s16(a), c0);
177 const int32x4_t a2 = vmull_n_s16(vget_low_s16(a), c1);
178 const int32x4_t a3 = vmull_n_s16(vget_high_s16(a), c1);
179 const int32x4_t sum0 = vmlal_n_s16(a2, vget_low_s16(b), c0);
180 const int32x4_t sum1 = vmlal_n_s16(a3, vget_high_s16(b), c0);
181 const int32x4_t diff0 = vmlsl_n_s16(a0, vget_low_s16(b), c1);
182 const int32x4_t diff1 = vmlsl_n_s16(a1, vget_high_s16(b), c1);
183 const int16x4_t rounded0 = vqrshrn_n_s32(sum0, 14);
184 const int16x4_t rounded1 = vqrshrn_n_s32(sum1, 14);
185 const int16x4_t rounded2 = vqrshrn_n_s32(diff0, 14);
186 const int16x4_t rounded3 = vqrshrn_n_s32(diff1, 14);
187 *add = vcombine_s16(rounded0, rounded1);
188 *sub = vcombine_s16(rounded2, rounded3);
189 }
190
191 // Transpose 8x8 to a new location. Don't use transpose_neon.h because those
192 // are all in-place.
transpose_8x8(const int16x8_t * a,int16x8_t * b)193 static INLINE void transpose_8x8(const int16x8_t *a /*[8]*/,
194 int16x8_t *b /*[8]*/) {
195 // Swap 16 bit elements.
196 const int16x8x2_t c0 = vtrnq_s16(a[0], a[1]);
197 const int16x8x2_t c1 = vtrnq_s16(a[2], a[3]);
198 const int16x8x2_t c2 = vtrnq_s16(a[4], a[5]);
199 const int16x8x2_t c3 = vtrnq_s16(a[6], a[7]);
200
201 // Swap 32 bit elements.
202 const int32x4x2_t d0 = vtrnq_s32(vreinterpretq_s32_s16(c0.val[0]),
203 vreinterpretq_s32_s16(c1.val[0]));
204 const int32x4x2_t d1 = vtrnq_s32(vreinterpretq_s32_s16(c0.val[1]),
205 vreinterpretq_s32_s16(c1.val[1]));
206 const int32x4x2_t d2 = vtrnq_s32(vreinterpretq_s32_s16(c2.val[0]),
207 vreinterpretq_s32_s16(c3.val[0]));
208 const int32x4x2_t d3 = vtrnq_s32(vreinterpretq_s32_s16(c2.val[1]),
209 vreinterpretq_s32_s16(c3.val[1]));
210
211 // Swap 64 bit elements
212 const int16x8x2_t e0 = vpx_vtrnq_s64_to_s16(d0.val[0], d2.val[0]);
213 const int16x8x2_t e1 = vpx_vtrnq_s64_to_s16(d1.val[0], d3.val[0]);
214 const int16x8x2_t e2 = vpx_vtrnq_s64_to_s16(d0.val[1], d2.val[1]);
215 const int16x8x2_t e3 = vpx_vtrnq_s64_to_s16(d1.val[1], d3.val[1]);
216
217 b[0] = e0.val[0];
218 b[1] = e1.val[0];
219 b[2] = e2.val[0];
220 b[3] = e3.val[0];
221 b[4] = e0.val[1];
222 b[5] = e1.val[1];
223 b[6] = e2.val[1];
224 b[7] = e3.val[1];
225 }
226
227 // Main body of fdct16x16.
dct_body(const int16x8_t * in,int16x8_t * out)228 static void dct_body(const int16x8_t *in /*[16]*/, int16x8_t *out /*[16]*/) {
229 int16x8_t s[8];
230 int16x8_t x[4];
231 int16x8_t step[8];
232
233 // stage 1
234 // From fwd_txfm.c: Work on the first eight values; fdct8(input,
235 // even_results);"
236 s[0] = vaddq_s16(in[0], in[7]);
237 s[1] = vaddq_s16(in[1], in[6]);
238 s[2] = vaddq_s16(in[2], in[5]);
239 s[3] = vaddq_s16(in[3], in[4]);
240 s[4] = vsubq_s16(in[3], in[4]);
241 s[5] = vsubq_s16(in[2], in[5]);
242 s[6] = vsubq_s16(in[1], in[6]);
243 s[7] = vsubq_s16(in[0], in[7]);
244
245 // fdct4(step, step);
246 x[0] = vaddq_s16(s[0], s[3]);
247 x[1] = vaddq_s16(s[1], s[2]);
248 x[2] = vsubq_s16(s[1], s[2]);
249 x[3] = vsubq_s16(s[0], s[3]);
250
251 // out[0] = fdct_round_shift((x0 + x1) * cospi_16_64)
252 // out[8] = fdct_round_shift((x0 - x1) * cospi_16_64)
253 butterfly_one_coeff(x[0], x[1], cospi_16_64, &out[0], &out[8]);
254 // out[4] = fdct_round_shift(x3 * cospi_8_64 + x2 * cospi_24_64);
255 // out[12] = fdct_round_shift(x3 * cospi_24_64 - x2 * cospi_8_64);
256 butterfly_two_coeff(x[3], x[2], cospi_24_64, cospi_8_64, &out[4], &out[12]);
257
258 // Stage 2
259 // Re-using source s5/s6
260 // s5 = fdct_round_shift((s6 - s5) * cospi_16_64)
261 // s6 = fdct_round_shift((s6 + s5) * cospi_16_64)
262 butterfly_one_coeff(s[6], s[5], cospi_16_64, &s[6], &s[5]);
263
264 // Stage 3
265 x[0] = vaddq_s16(s[4], s[5]);
266 x[1] = vsubq_s16(s[4], s[5]);
267 x[2] = vsubq_s16(s[7], s[6]);
268 x[3] = vaddq_s16(s[7], s[6]);
269
270 // Stage 4
271 // out[2] = fdct_round_shift(x0 * cospi_28_64 + x3 * cospi_4_64)
272 // out[14] = fdct_round_shift(x3 * cospi_28_64 + x0 * -cospi_4_64)
273 butterfly_two_coeff(x[3], x[0], cospi_28_64, cospi_4_64, &out[2], &out[14]);
274 // out[6] = fdct_round_shift(x1 * cospi_12_64 + x2 * cospi_20_64)
275 // out[10] = fdct_round_shift(x2 * cospi_12_64 + x1 * -cospi_20_64)
276 butterfly_two_coeff(x[2], x[1], cospi_12_64, cospi_20_64, &out[10], &out[6]);
277
278 // step 2
279 // From fwd_txfm.c: Work on the next eight values; step1 -> odd_results"
280 // That file distinguished between "in_high" and "step1" but the only
281 // difference is that "in_high" is the first 8 values and "step 1" is the
282 // second. Here, since they are all in one array, "step1" values are += 8.
283
284 // step2[2] = fdct_round_shift((step1[5] - step1[2]) * cospi_16_64)
285 // step2[3] = fdct_round_shift((step1[4] - step1[3]) * cospi_16_64)
286 // step2[4] = fdct_round_shift((step1[4] + step1[3]) * cospi_16_64)
287 // step2[5] = fdct_round_shift((step1[5] + step1[2]) * cospi_16_64)
288 butterfly_one_coeff(in[13], in[10], cospi_16_64, &s[5], &s[2]);
289 butterfly_one_coeff(in[12], in[11], cospi_16_64, &s[4], &s[3]);
290
291 // step 3
292 s[0] = vaddq_s16(in[8], s[3]);
293 s[1] = vaddq_s16(in[9], s[2]);
294 x[0] = vsubq_s16(in[9], s[2]);
295 x[1] = vsubq_s16(in[8], s[3]);
296 x[2] = vsubq_s16(in[15], s[4]);
297 x[3] = vsubq_s16(in[14], s[5]);
298 s[6] = vaddq_s16(in[14], s[5]);
299 s[7] = vaddq_s16(in[15], s[4]);
300
301 // step 4
302 // step2[1] = fdct_round_shift(step3[1] *-cospi_8_64 + step3[6] * cospi_24_64)
303 // step2[6] = fdct_round_shift(step3[1] * cospi_24_64 + step3[6] * cospi_8_64)
304 butterfly_two_coeff(s[6], s[1], cospi_24_64, cospi_8_64, &s[6], &s[1]);
305
306 // step2[2] = fdct_round_shift(step3[2] * cospi_24_64 + step3[5] * cospi_8_64)
307 // step2[5] = fdct_round_shift(step3[2] * cospi_8_64 - step3[5] * cospi_24_64)
308 butterfly_two_coeff(x[0], x[3], cospi_8_64, cospi_24_64, &s[2], &s[5]);
309
310 // step 5
311 step[0] = vaddq_s16(s[0], s[1]);
312 step[1] = vsubq_s16(s[0], s[1]);
313 step[2] = vaddq_s16(x[1], s[2]);
314 step[3] = vsubq_s16(x[1], s[2]);
315 step[4] = vsubq_s16(x[2], s[5]);
316 step[5] = vaddq_s16(x[2], s[5]);
317 step[6] = vsubq_s16(s[7], s[6]);
318 step[7] = vaddq_s16(s[7], s[6]);
319
320 // step 6
321 // out[1] = fdct_round_shift(step1[0] * cospi_30_64 + step1[7] * cospi_2_64)
322 // out[9] = fdct_round_shift(step1[1] * cospi_14_64 + step1[6] * cospi_18_64)
323 // out[5] = fdct_round_shift(step1[2] * cospi_22_64 + step1[5] * cospi_10_64)
324 // out[13] = fdct_round_shift(step1[3] * cospi_6_64 + step1[4] * cospi_26_64)
325 // out[3] = fdct_round_shift(step1[3] * -cospi_26_64 + step1[4] * cospi_6_64)
326 // out[11] = fdct_round_shift(step1[2] * -cospi_10_64 + step1[5] *
327 // cospi_22_64)
328 // out[7] = fdct_round_shift(step1[1] * -cospi_18_64 + step1[6] * cospi_14_64)
329 // out[15] = fdct_round_shift(step1[0] * -cospi_2_64 + step1[7] * cospi_30_64)
330 butterfly_two_coeff(step[6], step[1], cospi_14_64, cospi_18_64, &out[9],
331 &out[7]);
332 butterfly_two_coeff(step[7], step[0], cospi_30_64, cospi_2_64, &out[1],
333 &out[15]);
334 butterfly_two_coeff(step[4], step[3], cospi_6_64, cospi_26_64, &out[13],
335 &out[3]);
336 butterfly_two_coeff(step[5], step[2], cospi_22_64, cospi_10_64, &out[5],
337 &out[11]);
338 }
339
vpx_fdct16x16_neon(const int16_t * input,tran_low_t * output,int stride)340 void vpx_fdct16x16_neon(const int16_t *input, tran_low_t *output, int stride) {
341 int16x8_t temp0[16];
342 int16x8_t temp1[16];
343 int16x8_t temp2[16];
344 int16x8_t temp3[16];
345
346 // Left half.
347 load(input, stride, temp0);
348 cross_input(temp0, temp1, 0);
349 dct_body(temp1, temp0);
350
351 // Right half.
352 load(input + 8, stride, temp1);
353 cross_input(temp1, temp2, 0);
354 dct_body(temp2, temp1);
355
356 // Transpose top left and top right quarters into one contiguous location to
357 // process to the top half.
358 transpose_8x8(&temp0[0], &temp2[0]);
359 transpose_8x8(&temp1[0], &temp2[8]);
360 partial_round_shift(temp2);
361 cross_input(temp2, temp3, 1);
362 dct_body(temp3, temp2);
363 transpose_s16_8x8(&temp2[0], &temp2[1], &temp2[2], &temp2[3], &temp2[4],
364 &temp2[5], &temp2[6], &temp2[7]);
365 transpose_s16_8x8(&temp2[8], &temp2[9], &temp2[10], &temp2[11], &temp2[12],
366 &temp2[13], &temp2[14], &temp2[15]);
367 store(output, temp2);
368 store(output + 8, temp2 + 8);
369 output += 8 * 16;
370
371 // Transpose bottom left and bottom right quarters into one contiguous
372 // location to process to the bottom half.
373 transpose_8x8(&temp0[8], &temp1[0]);
374 transpose_s16_8x8(&temp1[8], &temp1[9], &temp1[10], &temp1[11], &temp1[12],
375 &temp1[13], &temp1[14], &temp1[15]);
376 partial_round_shift(temp1);
377 cross_input(temp1, temp0, 1);
378 dct_body(temp0, temp1);
379 transpose_s16_8x8(&temp1[0], &temp1[1], &temp1[2], &temp1[3], &temp1[4],
380 &temp1[5], &temp1[6], &temp1[7]);
381 transpose_s16_8x8(&temp1[8], &temp1[9], &temp1[10], &temp1[11], &temp1[12],
382 &temp1[13], &temp1[14], &temp1[15]);
383 store(output, temp1);
384 store(output + 8, temp1 + 8);
385 }
386 #endif // !defined(__clang__) && !defined(__ANDROID__) && defined(__GNUC__) &&
387 // __GNUC__ == 4 && __GNUC_MINOR__ == 9 && __GNUC_PATCHLEVEL__ < 4
388