1/*
2 *  Copyright (c) 2011 The WebRTC 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/*
12 * The core AEC algorithm, SSE2 version of speed-critical functions.
13 */
14
15#include "typedefs.h"
16
17#if defined(WEBRTC_USE_SSE2)
18#include <emmintrin.h>
19#include <math.h>
20
21#include "aec_core.h"
22#include "aec_rdft.h"
23
24__inline static float MulRe(float aRe, float aIm, float bRe, float bIm)
25{
26  return aRe * bRe - aIm * bIm;
27}
28
29__inline static float MulIm(float aRe, float aIm, float bRe, float bIm)
30{
31  return aRe * bIm + aIm * bRe;
32}
33
34static void FilterFarSSE2(aec_t *aec, float yf[2][PART_LEN1])
35{
36  int i;
37  for (i = 0; i < NR_PART; i++) {
38    int j;
39    int xPos = (i + aec->xfBufBlockPos) * PART_LEN1;
40    int pos = i * PART_LEN1;
41    // Check for wrap
42    if (i + aec->xfBufBlockPos >= NR_PART) {
43      xPos -= NR_PART*(PART_LEN1);
44    }
45
46    // vectorized code (four at once)
47    for (j = 0; j + 3 < PART_LEN1; j += 4) {
48      const __m128 xfBuf_re = _mm_loadu_ps(&aec->xfBuf[0][xPos + j]);
49      const __m128 xfBuf_im = _mm_loadu_ps(&aec->xfBuf[1][xPos + j]);
50      const __m128 wfBuf_re = _mm_loadu_ps(&aec->wfBuf[0][pos + j]);
51      const __m128 wfBuf_im = _mm_loadu_ps(&aec->wfBuf[1][pos + j]);
52      const __m128 yf_re = _mm_loadu_ps(&yf[0][j]);
53      const __m128 yf_im = _mm_loadu_ps(&yf[1][j]);
54      const __m128 a = _mm_mul_ps(xfBuf_re, wfBuf_re);
55      const __m128 b = _mm_mul_ps(xfBuf_im, wfBuf_im);
56      const __m128 c = _mm_mul_ps(xfBuf_re, wfBuf_im);
57      const __m128 d = _mm_mul_ps(xfBuf_im, wfBuf_re);
58      const __m128 e = _mm_sub_ps(a, b);
59      const __m128 f = _mm_add_ps(c, d);
60      const __m128 g = _mm_add_ps(yf_re, e);
61      const __m128 h = _mm_add_ps(yf_im, f);
62      _mm_storeu_ps(&yf[0][j], g);
63      _mm_storeu_ps(&yf[1][j], h);
64    }
65    // scalar code for the remaining items.
66    for (; j < PART_LEN1; j++) {
67      yf[0][j] += MulRe(aec->xfBuf[0][xPos + j], aec->xfBuf[1][xPos + j],
68                        aec->wfBuf[0][ pos + j], aec->wfBuf[1][ pos + j]);
69      yf[1][j] += MulIm(aec->xfBuf[0][xPos + j], aec->xfBuf[1][xPos + j],
70                        aec->wfBuf[0][ pos + j], aec->wfBuf[1][ pos + j]);
71    }
72  }
73}
74
75static void ScaleErrorSignalSSE2(aec_t *aec, float ef[2][PART_LEN1])
76{
77  const __m128 k1e_10f = _mm_set1_ps(1e-10f);
78  const __m128 kThresh = _mm_set1_ps(aec->errThresh);
79  const __m128 kMu = _mm_set1_ps(aec->mu);
80
81  int i;
82  // vectorized code (four at once)
83  for (i = 0; i + 3 < PART_LEN1; i += 4) {
84    const __m128 xPow = _mm_loadu_ps(&aec->xPow[i]);
85    const __m128 ef_re_base = _mm_loadu_ps(&ef[0][i]);
86    const __m128 ef_im_base = _mm_loadu_ps(&ef[1][i]);
87
88    const __m128 xPowPlus = _mm_add_ps(xPow, k1e_10f);
89    __m128 ef_re = _mm_div_ps(ef_re_base, xPowPlus);
90    __m128 ef_im = _mm_div_ps(ef_im_base, xPowPlus);
91    const __m128 ef_re2 = _mm_mul_ps(ef_re, ef_re);
92    const __m128 ef_im2 = _mm_mul_ps(ef_im, ef_im);
93    const __m128 ef_sum2 = _mm_add_ps(ef_re2, ef_im2);
94    const __m128 absEf = _mm_sqrt_ps(ef_sum2);
95    const __m128 bigger = _mm_cmpgt_ps(absEf, kThresh);
96    __m128 absEfPlus = _mm_add_ps(absEf, k1e_10f);
97    const __m128 absEfInv = _mm_div_ps(kThresh, absEfPlus);
98    __m128 ef_re_if = _mm_mul_ps(ef_re, absEfInv);
99    __m128 ef_im_if = _mm_mul_ps(ef_im, absEfInv);
100    ef_re_if = _mm_and_ps(bigger, ef_re_if);
101    ef_im_if = _mm_and_ps(bigger, ef_im_if);
102    ef_re = _mm_andnot_ps(bigger, ef_re);
103    ef_im = _mm_andnot_ps(bigger, ef_im);
104    ef_re = _mm_or_ps(ef_re, ef_re_if);
105    ef_im = _mm_or_ps(ef_im, ef_im_if);
106    ef_re = _mm_mul_ps(ef_re, kMu);
107    ef_im = _mm_mul_ps(ef_im, kMu);
108
109    _mm_storeu_ps(&ef[0][i], ef_re);
110    _mm_storeu_ps(&ef[1][i], ef_im);
111  }
112  // scalar code for the remaining items.
113  for (; i < (PART_LEN1); i++) {
114    float absEf;
115    ef[0][i] /= (aec->xPow[i] + 1e-10f);
116    ef[1][i] /= (aec->xPow[i] + 1e-10f);
117    absEf = sqrtf(ef[0][i] * ef[0][i] + ef[1][i] * ef[1][i]);
118
119    if (absEf > aec->errThresh) {
120      absEf = aec->errThresh / (absEf + 1e-10f);
121      ef[0][i] *= absEf;
122      ef[1][i] *= absEf;
123    }
124
125    // Stepsize factor
126    ef[0][i] *= aec->mu;
127    ef[1][i] *= aec->mu;
128  }
129}
130
131static void FilterAdaptationSSE2(aec_t *aec, float *fft, float ef[2][PART_LEN1]) {
132  int i, j;
133  for (i = 0; i < NR_PART; i++) {
134    int xPos = (i + aec->xfBufBlockPos)*(PART_LEN1);
135    int pos = i * PART_LEN1;
136    // Check for wrap
137    if (i + aec->xfBufBlockPos >= NR_PART) {
138      xPos -= NR_PART * PART_LEN1;
139    }
140
141    // Process the whole array...
142    for (j = 0; j < PART_LEN; j+= 4) {
143      // Load xfBuf and ef.
144      const __m128 xfBuf_re = _mm_loadu_ps(&aec->xfBuf[0][xPos + j]);
145      const __m128 xfBuf_im = _mm_loadu_ps(&aec->xfBuf[1][xPos + j]);
146      const __m128 ef_re = _mm_loadu_ps(&ef[0][j]);
147      const __m128 ef_im = _mm_loadu_ps(&ef[1][j]);
148      // Calculate the product of conjugate(xfBuf) by ef.
149      //   re(conjugate(a) * b) = aRe * bRe + aIm * bIm
150      //   im(conjugate(a) * b)=  aRe * bIm - aIm * bRe
151      const __m128 a = _mm_mul_ps(xfBuf_re, ef_re);
152      const __m128 b = _mm_mul_ps(xfBuf_im, ef_im);
153      const __m128 c = _mm_mul_ps(xfBuf_re, ef_im);
154      const __m128 d = _mm_mul_ps(xfBuf_im, ef_re);
155      const __m128 e = _mm_add_ps(a, b);
156      const __m128 f = _mm_sub_ps(c, d);
157      // Interleave real and imaginary parts.
158      const __m128 g = _mm_unpacklo_ps(e, f);
159      const __m128 h = _mm_unpackhi_ps(e, f);
160      // Store
161      _mm_storeu_ps(&fft[2*j + 0], g);
162      _mm_storeu_ps(&fft[2*j + 4], h);
163    }
164    // ... and fixup the first imaginary entry.
165    fft[1] = MulRe(aec->xfBuf[0][xPos + PART_LEN],
166                   -aec->xfBuf[1][xPos + PART_LEN],
167                   ef[0][PART_LEN], ef[1][PART_LEN]);
168
169    aec_rdft_inverse_128(fft);
170    memset(fft + PART_LEN, 0, sizeof(float)*PART_LEN);
171
172    // fft scaling
173    {
174      float scale = 2.0f / PART_LEN2;
175      const __m128 scale_ps = _mm_load_ps1(&scale);
176      for (j = 0; j < PART_LEN; j+=4) {
177        const __m128 fft_ps = _mm_loadu_ps(&fft[j]);
178        const __m128 fft_scale = _mm_mul_ps(fft_ps, scale_ps);
179        _mm_storeu_ps(&fft[j], fft_scale);
180      }
181    }
182    aec_rdft_forward_128(fft);
183
184    {
185      float wt1 = aec->wfBuf[1][pos];
186      aec->wfBuf[0][pos + PART_LEN] += fft[1];
187      for (j = 0; j < PART_LEN; j+= 4) {
188        __m128 wtBuf_re = _mm_loadu_ps(&aec->wfBuf[0][pos + j]);
189        __m128 wtBuf_im = _mm_loadu_ps(&aec->wfBuf[1][pos + j]);
190        const __m128 fft0 = _mm_loadu_ps(&fft[2 * j + 0]);
191        const __m128 fft4 = _mm_loadu_ps(&fft[2 * j + 4]);
192        const __m128 fft_re = _mm_shuffle_ps(fft0, fft4, _MM_SHUFFLE(2, 0, 2 ,0));
193        const __m128 fft_im = _mm_shuffle_ps(fft0, fft4, _MM_SHUFFLE(3, 1, 3 ,1));
194        wtBuf_re = _mm_add_ps(wtBuf_re, fft_re);
195        wtBuf_im = _mm_add_ps(wtBuf_im, fft_im);
196        _mm_storeu_ps(&aec->wfBuf[0][pos + j], wtBuf_re);
197        _mm_storeu_ps(&aec->wfBuf[1][pos + j], wtBuf_im);
198      }
199      aec->wfBuf[1][pos] = wt1;
200    }
201  }
202}
203
204static __m128 mm_pow_ps(__m128 a, __m128 b)
205{
206  // a^b = exp2(b * log2(a))
207  //   exp2(x) and log2(x) are calculated using polynomial approximations.
208  __m128 log2_a, b_log2_a, a_exp_b;
209
210  // Calculate log2(x), x = a.
211  {
212    // To calculate log2(x), we decompose x like this:
213    //   x = y * 2^n
214    //     n is an integer
215    //     y is in the [1.0, 2.0) range
216    //
217    //   log2(x) = log2(y) + n
218    //     n       can be evaluated by playing with float representation.
219    //     log2(y) in a small range can be approximated, this code uses an order
220    //             five polynomial approximation. The coefficients have been
221    //             estimated with the Remez algorithm and the resulting
222    //             polynomial has a maximum relative error of 0.00086%.
223
224    // Compute n.
225    //    This is done by masking the exponent, shifting it into the top bit of
226    //    the mantissa, putting eight into the biased exponent (to shift/
227    //    compensate the fact that the exponent has been shifted in the top/
228    //    fractional part and finally getting rid of the implicit leading one
229    //    from the mantissa by substracting it out.
230    static const ALIGN16_BEG int float_exponent_mask[4] ALIGN16_END =
231        {0x7F800000, 0x7F800000, 0x7F800000, 0x7F800000};
232    static const ALIGN16_BEG int eight_biased_exponent[4] ALIGN16_END =
233        {0x43800000, 0x43800000, 0x43800000, 0x43800000};
234    static const ALIGN16_BEG int implicit_leading_one[4] ALIGN16_END =
235        {0x43BF8000, 0x43BF8000, 0x43BF8000, 0x43BF8000};
236    static const int shift_exponent_into_top_mantissa = 8;
237    const __m128 two_n = _mm_and_ps(a, *((__m128 *)float_exponent_mask));
238    const __m128 n_1 = _mm_castsi128_ps(_mm_srli_epi32(_mm_castps_si128(two_n),
239        shift_exponent_into_top_mantissa));
240    const __m128 n_0 = _mm_or_ps(n_1, *((__m128 *)eight_biased_exponent));
241    const __m128 n   = _mm_sub_ps(n_0,  *((__m128 *)implicit_leading_one));
242
243    // Compute y.
244    static const ALIGN16_BEG int mantissa_mask[4] ALIGN16_END =
245        {0x007FFFFF, 0x007FFFFF, 0x007FFFFF, 0x007FFFFF};
246    static const ALIGN16_BEG int zero_biased_exponent_is_one[4] ALIGN16_END =
247        {0x3F800000, 0x3F800000, 0x3F800000, 0x3F800000};
248    const __m128 mantissa = _mm_and_ps(a, *((__m128 *)mantissa_mask));
249    const __m128 y        = _mm_or_ps(
250        mantissa,  *((__m128 *)zero_biased_exponent_is_one));
251
252    // Approximate log2(y) ~= (y - 1) * pol5(y).
253    //    pol5(y) = C5 * y^5 + C4 * y^4 + C3 * y^3 + C2 * y^2 + C1 * y + C0
254    static const ALIGN16_BEG float ALIGN16_END C5[4] =
255        {-3.4436006e-2f, -3.4436006e-2f, -3.4436006e-2f, -3.4436006e-2f};
256    static const ALIGN16_BEG float ALIGN16_END C4[4] =
257        {3.1821337e-1f, 3.1821337e-1f, 3.1821337e-1f, 3.1821337e-1f};
258    static const ALIGN16_BEG float ALIGN16_END C3[4] =
259        {-1.2315303f, -1.2315303f, -1.2315303f, -1.2315303f};
260    static const ALIGN16_BEG float ALIGN16_END C2[4] =
261        {2.5988452f, 2.5988452f, 2.5988452f, 2.5988452f};
262    static const ALIGN16_BEG float ALIGN16_END C1[4] =
263        {-3.3241990f, -3.3241990f, -3.3241990f, -3.3241990f};
264    static const ALIGN16_BEG float ALIGN16_END C0[4] =
265        {3.1157899f, 3.1157899f, 3.1157899f, 3.1157899f};
266    const __m128 pol5_y_0 = _mm_mul_ps(y,        *((__m128 *)C5));
267    const __m128 pol5_y_1 = _mm_add_ps(pol5_y_0, *((__m128 *)C4));
268    const __m128 pol5_y_2 = _mm_mul_ps(pol5_y_1, y);
269    const __m128 pol5_y_3 = _mm_add_ps(pol5_y_2, *((__m128 *)C3));
270    const __m128 pol5_y_4 = _mm_mul_ps(pol5_y_3, y);
271    const __m128 pol5_y_5 = _mm_add_ps(pol5_y_4, *((__m128 *)C2));
272    const __m128 pol5_y_6 = _mm_mul_ps(pol5_y_5, y);
273    const __m128 pol5_y_7 = _mm_add_ps(pol5_y_6, *((__m128 *)C1));
274    const __m128 pol5_y_8 = _mm_mul_ps(pol5_y_7, y);
275    const __m128 pol5_y   = _mm_add_ps(pol5_y_8, *((__m128 *)C0));
276    const __m128 y_minus_one = _mm_sub_ps(
277        y, *((__m128 *)zero_biased_exponent_is_one));
278    const __m128 log2_y = _mm_mul_ps(y_minus_one ,  pol5_y);
279
280    // Combine parts.
281    log2_a = _mm_add_ps(n, log2_y);
282  }
283
284  // b * log2(a)
285  b_log2_a = _mm_mul_ps(b, log2_a);
286
287  // Calculate exp2(x), x = b * log2(a).
288  {
289    // To calculate 2^x, we decompose x like this:
290    //   x = n + y
291    //     n is an integer, the value of x - 0.5 rounded down, therefore
292    //     y is in the [0.5, 1.5) range
293    //
294    //   2^x = 2^n * 2^y
295    //     2^n can be evaluated by playing with float representation.
296    //     2^y in a small range can be approximated, this code uses an order two
297    //         polynomial approximation. The coefficients have been estimated
298    //         with the Remez algorithm and the resulting polynomial has a
299    //         maximum relative error of 0.17%.
300
301    // To avoid over/underflow, we reduce the range of input to ]-127, 129].
302    static const ALIGN16_BEG float max_input[4] ALIGN16_END =
303        {129.f, 129.f, 129.f, 129.f};
304    static const ALIGN16_BEG float min_input[4] ALIGN16_END =
305        {-126.99999f, -126.99999f, -126.99999f, -126.99999f};
306    const __m128 x_min = _mm_min_ps(b_log2_a, *((__m128 *)max_input));
307    const __m128 x_max = _mm_max_ps(x_min,    *((__m128 *)min_input));
308    // Compute n.
309    static const ALIGN16_BEG float half[4] ALIGN16_END =
310        {0.5f, 0.5f, 0.5f, 0.5f};
311    const __m128  x_minus_half = _mm_sub_ps(x_max, *((__m128 *)half));
312    const __m128i x_minus_half_floor = _mm_cvtps_epi32(x_minus_half);
313    // Compute 2^n.
314    static const ALIGN16_BEG int float_exponent_bias[4] ALIGN16_END =
315        {127, 127, 127, 127};
316    static const int float_exponent_shift = 23;
317    const __m128i two_n_exponent = _mm_add_epi32(
318        x_minus_half_floor, *((__m128i *)float_exponent_bias));
319    const __m128  two_n = _mm_castsi128_ps(_mm_slli_epi32(
320        two_n_exponent, float_exponent_shift));
321    // Compute y.
322    const __m128 y = _mm_sub_ps(x_max, _mm_cvtepi32_ps(x_minus_half_floor));
323    // Approximate 2^y ~= C2 * y^2 + C1 * y + C0.
324    static const ALIGN16_BEG float C2[4] ALIGN16_END =
325        {3.3718944e-1f, 3.3718944e-1f, 3.3718944e-1f, 3.3718944e-1f};
326    static const ALIGN16_BEG float C1[4] ALIGN16_END =
327        {6.5763628e-1f, 6.5763628e-1f, 6.5763628e-1f, 6.5763628e-1f};
328    static const ALIGN16_BEG float C0[4] ALIGN16_END =
329        {1.0017247f, 1.0017247f, 1.0017247f, 1.0017247f};
330    const __m128 exp2_y_0 = _mm_mul_ps(y,        *((__m128 *)C2));
331    const __m128 exp2_y_1 = _mm_add_ps(exp2_y_0, *((__m128 *)C1));
332    const __m128 exp2_y_2 = _mm_mul_ps(exp2_y_1, y);
333    const __m128 exp2_y   = _mm_add_ps(exp2_y_2, *((__m128 *)C0));
334
335    // Combine parts.
336    a_exp_b = _mm_mul_ps(exp2_y, two_n);
337  }
338  return a_exp_b;
339}
340
341extern const float WebRtcAec_weightCurve[65];
342extern const float WebRtcAec_overDriveCurve[65];
343
344static void OverdriveAndSuppressSSE2(aec_t *aec, float hNl[PART_LEN1],
345                                     const float hNlFb,
346                                     float efw[2][PART_LEN1]) {
347  int i;
348  const __m128 vec_hNlFb = _mm_set1_ps(hNlFb);
349  const __m128 vec_one = _mm_set1_ps(1.0f);
350  const __m128 vec_minus_one = _mm_set1_ps(-1.0f);
351  const __m128 vec_overDriveSm = _mm_set1_ps(aec->overDriveSm);
352  // vectorized code (four at once)
353  for (i = 0; i + 3 < PART_LEN1; i+=4) {
354    // Weight subbands
355    __m128 vec_hNl = _mm_loadu_ps(&hNl[i]);
356    const __m128 vec_weightCurve = _mm_loadu_ps(&WebRtcAec_weightCurve[i]);
357    const __m128 bigger = _mm_cmpgt_ps(vec_hNl, vec_hNlFb);
358    const __m128 vec_weightCurve_hNlFb = _mm_mul_ps(
359        vec_weightCurve, vec_hNlFb);
360    const __m128 vec_one_weightCurve = _mm_sub_ps(vec_one, vec_weightCurve);
361    const __m128 vec_one_weightCurve_hNl = _mm_mul_ps(
362        vec_one_weightCurve, vec_hNl);
363    const __m128 vec_if0 = _mm_andnot_ps(bigger, vec_hNl);
364    const __m128 vec_if1 = _mm_and_ps(
365        bigger, _mm_add_ps(vec_weightCurve_hNlFb, vec_one_weightCurve_hNl));
366    vec_hNl = _mm_or_ps(vec_if0, vec_if1);
367
368    {
369      const __m128 vec_overDriveCurve = _mm_loadu_ps(
370          &WebRtcAec_overDriveCurve[i]);
371      const __m128 vec_overDriveSm_overDriveCurve = _mm_mul_ps(
372          vec_overDriveSm, vec_overDriveCurve);
373      vec_hNl = mm_pow_ps(vec_hNl, vec_overDriveSm_overDriveCurve);
374      _mm_storeu_ps(&hNl[i], vec_hNl);
375    }
376
377    // Suppress error signal
378    {
379      __m128 vec_efw_re = _mm_loadu_ps(&efw[0][i]);
380      __m128 vec_efw_im = _mm_loadu_ps(&efw[1][i]);
381      vec_efw_re = _mm_mul_ps(vec_efw_re, vec_hNl);
382      vec_efw_im = _mm_mul_ps(vec_efw_im, vec_hNl);
383
384      // Ooura fft returns incorrect sign on imaginary component. It matters
385      // here because we are making an additive change with comfort noise.
386      vec_efw_im = _mm_mul_ps(vec_efw_im, vec_minus_one);
387      _mm_storeu_ps(&efw[0][i], vec_efw_re);
388      _mm_storeu_ps(&efw[1][i], vec_efw_im);
389    }
390  }
391  // scalar code for the remaining items.
392  for (; i < PART_LEN1; i++) {
393    // Weight subbands
394    if (hNl[i] > hNlFb) {
395      hNl[i] = WebRtcAec_weightCurve[i] * hNlFb +
396          (1 - WebRtcAec_weightCurve[i]) * hNl[i];
397    }
398    hNl[i] = powf(hNl[i], aec->overDriveSm * WebRtcAec_overDriveCurve[i]);
399
400    // Suppress error signal
401    efw[0][i] *= hNl[i];
402    efw[1][i] *= hNl[i];
403
404    // Ooura fft returns incorrect sign on imaginary component. It matters
405    // here because we are making an additive change with comfort noise.
406    efw[1][i] *= -1;
407  }
408}
409
410void WebRtcAec_InitAec_SSE2(void) {
411  WebRtcAec_FilterFar = FilterFarSSE2;
412  WebRtcAec_ScaleErrorSignal = ScaleErrorSignalSSE2;
413  WebRtcAec_FilterAdaptation = FilterAdaptationSSE2;
414  WebRtcAec_OverdriveAndSuppress = OverdriveAndSuppressSSE2;
415}
416
417#endif   // WEBRTC_USE_SSE2
418