mirror of
https://github.com/danog/libtgvoip.git
synced 2024-12-03 10:07:45 +01:00
5caaaafa42
I'm now using the entire audio processing module from WebRTC as opposed to individual DSP algorithms pulled from there before. Seems to work better this way.
541 lines
13 KiB
C++
541 lines
13 KiB
C++
/*
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* http://www.kurims.kyoto-u.ac.jp/~ooura/fft.html
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* Copyright Takuya OOURA, 1996-2001
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*
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* You may use, copy, modify and distribute this code for any purpose (include
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* commercial use) and without fee. Please refer to this package when you modify
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* this code.
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*
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* Changes by the WebRTC authors:
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* - Trivial type modifications.
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* - Minimal code subset to do rdft of length 128.
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* - Optimizations because of known length.
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* - Removed the global variables by moving the code in to a class in order
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* to make it thread safe.
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*
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* All changes are covered by the WebRTC license and IP grant:
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "modules/audio_processing/utility/ooura_fft.h"
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#include "modules/audio_processing/utility/ooura_fft_tables_common.h"
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#include "rtc_base/system/arch.h"
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#include "system_wrappers/include/cpu_features_wrapper.h"
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namespace webrtc {
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namespace {
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#if !(defined(MIPS_FPU_LE) || defined(WEBRTC_HAS_NEON))
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static void cft1st_128_C(float* a) {
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const int n = 128;
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int j, k1, k2;
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float wk1r, wk1i, wk2r, wk2i, wk3r, wk3i;
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float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
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// The processing of the first set of elements was simplified in C to avoid
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// some operations (multiplication by zero or one, addition of two elements
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// multiplied by the same weight, ...).
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x0r = a[0] + a[2];
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x0i = a[1] + a[3];
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x1r = a[0] - a[2];
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x1i = a[1] - a[3];
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x2r = a[4] + a[6];
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x2i = a[5] + a[7];
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x3r = a[4] - a[6];
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x3i = a[5] - a[7];
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a[0] = x0r + x2r;
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a[1] = x0i + x2i;
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a[4] = x0r - x2r;
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a[5] = x0i - x2i;
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a[2] = x1r - x3i;
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a[3] = x1i + x3r;
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a[6] = x1r + x3i;
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a[7] = x1i - x3r;
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wk1r = rdft_w[2];
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x0r = a[8] + a[10];
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x0i = a[9] + a[11];
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x1r = a[8] - a[10];
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x1i = a[9] - a[11];
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x2r = a[12] + a[14];
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x2i = a[13] + a[15];
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x3r = a[12] - a[14];
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x3i = a[13] - a[15];
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a[8] = x0r + x2r;
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a[9] = x0i + x2i;
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a[12] = x2i - x0i;
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a[13] = x0r - x2r;
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x0r = x1r - x3i;
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x0i = x1i + x3r;
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a[10] = wk1r * (x0r - x0i);
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a[11] = wk1r * (x0r + x0i);
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x0r = x3i + x1r;
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x0i = x3r - x1i;
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a[14] = wk1r * (x0i - x0r);
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a[15] = wk1r * (x0i + x0r);
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k1 = 0;
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for (j = 16; j < n; j += 16) {
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k1 += 2;
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k2 = 2 * k1;
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wk2r = rdft_w[k1 + 0];
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wk2i = rdft_w[k1 + 1];
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wk1r = rdft_w[k2 + 0];
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wk1i = rdft_w[k2 + 1];
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wk3r = rdft_wk3ri_first[k1 + 0];
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wk3i = rdft_wk3ri_first[k1 + 1];
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x0r = a[j + 0] + a[j + 2];
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x0i = a[j + 1] + a[j + 3];
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x1r = a[j + 0] - a[j + 2];
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x1i = a[j + 1] - a[j + 3];
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x2r = a[j + 4] + a[j + 6];
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x2i = a[j + 5] + a[j + 7];
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x3r = a[j + 4] - a[j + 6];
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x3i = a[j + 5] - a[j + 7];
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a[j + 0] = x0r + x2r;
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a[j + 1] = x0i + x2i;
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x0r -= x2r;
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x0i -= x2i;
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a[j + 4] = wk2r * x0r - wk2i * x0i;
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a[j + 5] = wk2r * x0i + wk2i * x0r;
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x0r = x1r - x3i;
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x0i = x1i + x3r;
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a[j + 2] = wk1r * x0r - wk1i * x0i;
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a[j + 3] = wk1r * x0i + wk1i * x0r;
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x0r = x1r + x3i;
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x0i = x1i - x3r;
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a[j + 6] = wk3r * x0r - wk3i * x0i;
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a[j + 7] = wk3r * x0i + wk3i * x0r;
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wk1r = rdft_w[k2 + 2];
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wk1i = rdft_w[k2 + 3];
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wk3r = rdft_wk3ri_second[k1 + 0];
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wk3i = rdft_wk3ri_second[k1 + 1];
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x0r = a[j + 8] + a[j + 10];
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x0i = a[j + 9] + a[j + 11];
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x1r = a[j + 8] - a[j + 10];
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x1i = a[j + 9] - a[j + 11];
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x2r = a[j + 12] + a[j + 14];
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x2i = a[j + 13] + a[j + 15];
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x3r = a[j + 12] - a[j + 14];
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x3i = a[j + 13] - a[j + 15];
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a[j + 8] = x0r + x2r;
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a[j + 9] = x0i + x2i;
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x0r -= x2r;
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x0i -= x2i;
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a[j + 12] = -wk2i * x0r - wk2r * x0i;
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a[j + 13] = -wk2i * x0i + wk2r * x0r;
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x0r = x1r - x3i;
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x0i = x1i + x3r;
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a[j + 10] = wk1r * x0r - wk1i * x0i;
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a[j + 11] = wk1r * x0i + wk1i * x0r;
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x0r = x1r + x3i;
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x0i = x1i - x3r;
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a[j + 14] = wk3r * x0r - wk3i * x0i;
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a[j + 15] = wk3r * x0i + wk3i * x0r;
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}
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}
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static void cftmdl_128_C(float* a) {
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const int l = 8;
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const int n = 128;
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const int m = 32;
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int j0, j1, j2, j3, k, k1, k2, m2;
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float wk1r, wk1i, wk2r, wk2i, wk3r, wk3i;
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float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
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for (j0 = 0; j0 < l; j0 += 2) {
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j1 = j0 + 8;
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j2 = j0 + 16;
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j3 = j0 + 24;
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x0r = a[j0 + 0] + a[j1 + 0];
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x0i = a[j0 + 1] + a[j1 + 1];
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x1r = a[j0 + 0] - a[j1 + 0];
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x1i = a[j0 + 1] - a[j1 + 1];
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x2r = a[j2 + 0] + a[j3 + 0];
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x2i = a[j2 + 1] + a[j3 + 1];
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x3r = a[j2 + 0] - a[j3 + 0];
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x3i = a[j2 + 1] - a[j3 + 1];
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a[j0 + 0] = x0r + x2r;
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a[j0 + 1] = x0i + x2i;
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a[j2 + 0] = x0r - x2r;
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a[j2 + 1] = x0i - x2i;
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a[j1 + 0] = x1r - x3i;
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a[j1 + 1] = x1i + x3r;
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a[j3 + 0] = x1r + x3i;
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a[j3 + 1] = x1i - x3r;
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}
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wk1r = rdft_w[2];
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for (j0 = m; j0 < l + m; j0 += 2) {
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j1 = j0 + 8;
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j2 = j0 + 16;
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j3 = j0 + 24;
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x0r = a[j0 + 0] + a[j1 + 0];
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x0i = a[j0 + 1] + a[j1 + 1];
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x1r = a[j0 + 0] - a[j1 + 0];
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x1i = a[j0 + 1] - a[j1 + 1];
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x2r = a[j2 + 0] + a[j3 + 0];
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x2i = a[j2 + 1] + a[j3 + 1];
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x3r = a[j2 + 0] - a[j3 + 0];
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x3i = a[j2 + 1] - a[j3 + 1];
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a[j0 + 0] = x0r + x2r;
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a[j0 + 1] = x0i + x2i;
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a[j2 + 0] = x2i - x0i;
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a[j2 + 1] = x0r - x2r;
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x0r = x1r - x3i;
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x0i = x1i + x3r;
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a[j1 + 0] = wk1r * (x0r - x0i);
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a[j1 + 1] = wk1r * (x0r + x0i);
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x0r = x3i + x1r;
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x0i = x3r - x1i;
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a[j3 + 0] = wk1r * (x0i - x0r);
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a[j3 + 1] = wk1r * (x0i + x0r);
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}
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k1 = 0;
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m2 = 2 * m;
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for (k = m2; k < n; k += m2) {
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k1 += 2;
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k2 = 2 * k1;
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wk2r = rdft_w[k1 + 0];
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wk2i = rdft_w[k1 + 1];
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wk1r = rdft_w[k2 + 0];
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wk1i = rdft_w[k2 + 1];
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wk3r = rdft_wk3ri_first[k1 + 0];
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wk3i = rdft_wk3ri_first[k1 + 1];
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for (j0 = k; j0 < l + k; j0 += 2) {
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j1 = j0 + 8;
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j2 = j0 + 16;
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j3 = j0 + 24;
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x0r = a[j0 + 0] + a[j1 + 0];
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x0i = a[j0 + 1] + a[j1 + 1];
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x1r = a[j0 + 0] - a[j1 + 0];
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x1i = a[j0 + 1] - a[j1 + 1];
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x2r = a[j2 + 0] + a[j3 + 0];
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x2i = a[j2 + 1] + a[j3 + 1];
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x3r = a[j2 + 0] - a[j3 + 0];
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x3i = a[j2 + 1] - a[j3 + 1];
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a[j0 + 0] = x0r + x2r;
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a[j0 + 1] = x0i + x2i;
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x0r -= x2r;
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x0i -= x2i;
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a[j2 + 0] = wk2r * x0r - wk2i * x0i;
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a[j2 + 1] = wk2r * x0i + wk2i * x0r;
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x0r = x1r - x3i;
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x0i = x1i + x3r;
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a[j1 + 0] = wk1r * x0r - wk1i * x0i;
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a[j1 + 1] = wk1r * x0i + wk1i * x0r;
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x0r = x1r + x3i;
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x0i = x1i - x3r;
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a[j3 + 0] = wk3r * x0r - wk3i * x0i;
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a[j3 + 1] = wk3r * x0i + wk3i * x0r;
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}
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wk1r = rdft_w[k2 + 2];
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wk1i = rdft_w[k2 + 3];
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wk3r = rdft_wk3ri_second[k1 + 0];
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wk3i = rdft_wk3ri_second[k1 + 1];
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for (j0 = k + m; j0 < l + (k + m); j0 += 2) {
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j1 = j0 + 8;
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j2 = j0 + 16;
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j3 = j0 + 24;
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x0r = a[j0 + 0] + a[j1 + 0];
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x0i = a[j0 + 1] + a[j1 + 1];
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x1r = a[j0 + 0] - a[j1 + 0];
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x1i = a[j0 + 1] - a[j1 + 1];
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x2r = a[j2 + 0] + a[j3 + 0];
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x2i = a[j2 + 1] + a[j3 + 1];
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x3r = a[j2 + 0] - a[j3 + 0];
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x3i = a[j2 + 1] - a[j3 + 1];
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a[j0 + 0] = x0r + x2r;
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a[j0 + 1] = x0i + x2i;
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x0r -= x2r;
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x0i -= x2i;
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a[j2 + 0] = -wk2i * x0r - wk2r * x0i;
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a[j2 + 1] = -wk2i * x0i + wk2r * x0r;
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x0r = x1r - x3i;
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x0i = x1i + x3r;
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a[j1 + 0] = wk1r * x0r - wk1i * x0i;
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a[j1 + 1] = wk1r * x0i + wk1i * x0r;
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x0r = x1r + x3i;
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x0i = x1i - x3r;
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a[j3 + 0] = wk3r * x0r - wk3i * x0i;
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a[j3 + 1] = wk3r * x0i + wk3i * x0r;
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}
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}
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}
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static void rftfsub_128_C(float* a) {
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const float* c = rdft_w + 32;
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int j1, j2, k1, k2;
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float wkr, wki, xr, xi, yr, yi;
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for (j1 = 1, j2 = 2; j2 < 64; j1 += 1, j2 += 2) {
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k2 = 128 - j2;
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k1 = 32 - j1;
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wkr = 0.5f - c[k1];
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wki = c[j1];
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xr = a[j2 + 0] - a[k2 + 0];
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xi = a[j2 + 1] + a[k2 + 1];
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yr = wkr * xr - wki * xi;
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yi = wkr * xi + wki * xr;
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a[j2 + 0] -= yr;
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a[j2 + 1] -= yi;
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a[k2 + 0] += yr;
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a[k2 + 1] -= yi;
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}
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}
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static void rftbsub_128_C(float* a) {
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const float* c = rdft_w + 32;
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int j1, j2, k1, k2;
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float wkr, wki, xr, xi, yr, yi;
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a[1] = -a[1];
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for (j1 = 1, j2 = 2; j2 < 64; j1 += 1, j2 += 2) {
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k2 = 128 - j2;
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k1 = 32 - j1;
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wkr = 0.5f - c[k1];
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wki = c[j1];
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xr = a[j2 + 0] - a[k2 + 0];
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xi = a[j2 + 1] + a[k2 + 1];
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yr = wkr * xr + wki * xi;
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yi = wkr * xi - wki * xr;
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a[j2 + 0] = a[j2 + 0] - yr;
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a[j2 + 1] = yi - a[j2 + 1];
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a[k2 + 0] = yr + a[k2 + 0];
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a[k2 + 1] = yi - a[k2 + 1];
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}
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a[65] = -a[65];
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}
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#endif
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} // namespace
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OouraFft::OouraFft() {
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#if defined(WEBRTC_ARCH_X86_FAMILY)
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use_sse2_ = (WebRtc_GetCPUInfo(kSSE2) != 0);
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#else
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use_sse2_ = false;
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#endif
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}
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OouraFft::~OouraFft() = default;
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void OouraFft::Fft(float* a) const {
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float xi;
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bitrv2_128(a);
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cftfsub_128(a);
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rftfsub_128(a);
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xi = a[0] - a[1];
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a[0] += a[1];
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a[1] = xi;
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}
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void OouraFft::InverseFft(float* a) const {
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a[1] = 0.5f * (a[0] - a[1]);
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a[0] -= a[1];
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rftbsub_128(a);
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bitrv2_128(a);
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cftbsub_128(a);
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}
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void OouraFft::cft1st_128(float* a) const {
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#if defined(MIPS_FPU_LE)
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cft1st_128_mips(a);
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#elif defined(WEBRTC_HAS_NEON)
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cft1st_128_neon(a);
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#elif defined(WEBRTC_ARCH_X86_FAMILY)
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if (use_sse2_) {
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cft1st_128_SSE2(a);
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} else {
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cft1st_128_C(a);
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}
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#else
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cft1st_128_C(a);
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#endif
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}
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void OouraFft::cftmdl_128(float* a) const {
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#if defined(MIPS_FPU_LE)
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cftmdl_128_mips(a);
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#elif defined(WEBRTC_HAS_NEON)
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cftmdl_128_neon(a);
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#elif defined(WEBRTC_ARCH_X86_FAMILY)
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if (use_sse2_) {
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cftmdl_128_SSE2(a);
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} else {
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cftmdl_128_C(a);
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}
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#else
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cftmdl_128_C(a);
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#endif
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}
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void OouraFft::rftfsub_128(float* a) const {
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#if defined(MIPS_FPU_LE)
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rftfsub_128_mips(a);
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#elif defined(WEBRTC_HAS_NEON)
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rftfsub_128_neon(a);
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#elif defined(WEBRTC_ARCH_X86_FAMILY)
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if (use_sse2_) {
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rftfsub_128_SSE2(a);
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} else {
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rftfsub_128_C(a);
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}
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#else
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rftfsub_128_C(a);
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#endif
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}
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void OouraFft::rftbsub_128(float* a) const {
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#if defined(MIPS_FPU_LE)
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rftbsub_128_mips(a);
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#elif defined(WEBRTC_HAS_NEON)
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rftbsub_128_neon(a);
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#elif defined(WEBRTC_ARCH_X86_FAMILY)
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if (use_sse2_) {
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rftbsub_128_SSE2(a);
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} else {
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rftbsub_128_C(a);
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}
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#else
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rftbsub_128_C(a);
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#endif
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}
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void OouraFft::cftbsub_128(float* a) const {
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int j, j1, j2, j3, l;
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float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
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cft1st_128(a);
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cftmdl_128(a);
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l = 32;
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for (j = 0; j < l; j += 2) {
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j1 = j + l;
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j2 = j1 + l;
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j3 = j2 + l;
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x0r = a[j] + a[j1];
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x0i = -a[j + 1] - a[j1 + 1];
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x1r = a[j] - a[j1];
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x1i = -a[j + 1] + a[j1 + 1];
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x2r = a[j2] + a[j3];
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x2i = a[j2 + 1] + a[j3 + 1];
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x3r = a[j2] - a[j3];
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x3i = a[j2 + 1] - a[j3 + 1];
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a[j] = x0r + x2r;
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a[j + 1] = x0i - x2i;
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a[j2] = x0r - x2r;
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a[j2 + 1] = x0i + x2i;
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a[j1] = x1r - x3i;
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a[j1 + 1] = x1i - x3r;
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a[j3] = x1r + x3i;
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a[j3 + 1] = x1i + x3r;
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}
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}
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void OouraFft::cftfsub_128(float* a) const {
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int j, j1, j2, j3, l;
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float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
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cft1st_128(a);
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cftmdl_128(a);
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l = 32;
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for (j = 0; j < l; j += 2) {
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j1 = j + l;
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j2 = j1 + l;
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j3 = j2 + l;
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x0r = a[j] + a[j1];
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x0i = a[j + 1] + a[j1 + 1];
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x1r = a[j] - a[j1];
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x1i = a[j + 1] - a[j1 + 1];
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x2r = a[j2] + a[j3];
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x2i = a[j2 + 1] + a[j3 + 1];
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x3r = a[j2] - a[j3];
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x3i = a[j2 + 1] - a[j3 + 1];
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a[j] = x0r + x2r;
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a[j + 1] = x0i + x2i;
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a[j2] = x0r - x2r;
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a[j2 + 1] = x0i - x2i;
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a[j1] = x1r - x3i;
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a[j1 + 1] = x1i + x3r;
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a[j3] = x1r + x3i;
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a[j3 + 1] = x1i - x3r;
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}
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}
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void OouraFft::bitrv2_128(float* a) const {
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/*
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Following things have been attempted but are no faster:
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(a) Storing the swap indexes in a LUT (index calculations are done
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for 'free' while waiting on memory/L1).
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(b) Consolidate the load/store of two consecutive floats by a 64 bit
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integer (execution is memory/L1 bound).
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(c) Do a mix of floats and 64 bit integer to maximize register
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utilization (execution is memory/L1 bound).
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(d) Replacing ip[i] by ((k<<31)>>25) + ((k >> 1)<<5).
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(e) Hard-coding of the offsets to completely eliminates index
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calculations.
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*/
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unsigned int j, j1, k, k1;
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float xr, xi, yr, yi;
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const int ip[4] = {0, 64, 32, 96};
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for (k = 0; k < 4; k++) {
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for (j = 0; j < k; j++) {
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j1 = 2 * j + ip[k];
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k1 = 2 * k + ip[j];
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xr = a[j1 + 0];
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xi = a[j1 + 1];
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yr = a[k1 + 0];
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yi = a[k1 + 1];
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a[j1 + 0] = yr;
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a[j1 + 1] = yi;
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a[k1 + 0] = xr;
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a[k1 + 1] = xi;
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j1 += 8;
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k1 += 16;
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xr = a[j1 + 0];
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xi = a[j1 + 1];
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yr = a[k1 + 0];
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yi = a[k1 + 1];
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a[j1 + 0] = yr;
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a[j1 + 1] = yi;
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a[k1 + 0] = xr;
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a[k1 + 1] = xi;
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|
j1 += 8;
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|
k1 -= 8;
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|
xr = a[j1 + 0];
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xi = a[j1 + 1];
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|
yr = a[k1 + 0];
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yi = a[k1 + 1];
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a[j1 + 0] = yr;
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a[j1 + 1] = yi;
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a[k1 + 0] = xr;
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a[k1 + 1] = xi;
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|
j1 += 8;
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|
k1 += 16;
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|
xr = a[j1 + 0];
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|
xi = a[j1 + 1];
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|
yr = a[k1 + 0];
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|
yi = a[k1 + 1];
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|
a[j1 + 0] = yr;
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|
a[j1 + 1] = yi;
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|
a[k1 + 0] = xr;
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|
a[k1 + 1] = xi;
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|
}
|
|
j1 = 2 * k + 8 + ip[k];
|
|
k1 = j1 + 8;
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|
xr = a[j1 + 0];
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|
xi = a[j1 + 1];
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|
yr = a[k1 + 0];
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yi = a[k1 + 1];
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|
a[j1 + 0] = yr;
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|
a[j1 + 1] = yi;
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|
a[k1 + 0] = xr;
|
|
a[k1 + 1] = xi;
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|
}
|
|
}
|
|
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|
} // namespace webrtc
|