1 /*
2 * Copyright (c) 2014 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 #include "webrtc/common_audio/fir_filter_sse.h"
12
13 #include <assert.h>
14 #include <string.h>
15 #include <xmmintrin.h>
16
17 #include "webrtc/system_wrappers/include/aligned_malloc.h"
18
19 namespace webrtc {
20
FIRFilterSSE2(const float * coefficients,size_t coefficients_length,size_t max_input_length)21 FIRFilterSSE2::FIRFilterSSE2(const float* coefficients,
22 size_t coefficients_length,
23 size_t max_input_length)
24 : // Closest higher multiple of four.
25 coefficients_length_((coefficients_length + 3) & ~0x03),
26 state_length_(coefficients_length_ - 1),
27 coefficients_(static_cast<float*>(
28 AlignedMalloc(sizeof(float) * coefficients_length_, 16))),
29 state_(static_cast<float*>(
30 AlignedMalloc(sizeof(float) * (max_input_length + state_length_),
31 16))) {
32 // Add zeros at the end of the coefficients.
33 size_t padding = coefficients_length_ - coefficients_length;
34 memset(coefficients_.get(), 0, padding * sizeof(coefficients_[0]));
35 // The coefficients are reversed to compensate for the order in which the
36 // input samples are acquired (most recent last).
37 for (size_t i = 0; i < coefficients_length; ++i) {
38 coefficients_[i + padding] = coefficients[coefficients_length - i - 1];
39 }
40 memset(state_.get(),
41 0,
42 (max_input_length + state_length_) * sizeof(state_[0]));
43 }
44
Filter(const float * in,size_t length,float * out)45 void FIRFilterSSE2::Filter(const float* in, size_t length, float* out) {
46 assert(length > 0);
47
48 memcpy(&state_[state_length_], in, length * sizeof(*in));
49
50 // Convolves the input signal |in| with the filter kernel |coefficients_|
51 // taking into account the previous state.
52 for (size_t i = 0; i < length; ++i) {
53 float* in_ptr = &state_[i];
54 float* coef_ptr = coefficients_.get();
55
56 __m128 m_sum = _mm_setzero_ps();
57 __m128 m_in;
58
59 // Depending on if the pointer is aligned with 16 bytes or not it is loaded
60 // differently.
61 if (reinterpret_cast<uintptr_t>(in_ptr) & 0x0F) {
62 for (size_t j = 0; j < coefficients_length_; j += 4) {
63 m_in = _mm_loadu_ps(in_ptr + j);
64 m_sum = _mm_add_ps(m_sum, _mm_mul_ps(m_in, _mm_load_ps(coef_ptr + j)));
65 }
66 } else {
67 for (size_t j = 0; j < coefficients_length_; j += 4) {
68 m_in = _mm_load_ps(in_ptr + j);
69 m_sum = _mm_add_ps(m_sum, _mm_mul_ps(m_in, _mm_load_ps(coef_ptr + j)));
70 }
71 }
72 m_sum = _mm_add_ps(_mm_movehl_ps(m_sum, m_sum), m_sum);
73 _mm_store_ss(out + i, _mm_add_ss(m_sum, _mm_shuffle_ps(m_sum, m_sum, 1)));
74 }
75
76 // Update current state.
77 memmove(state_.get(), &state_[length], state_length_ * sizeof(state_[0]));
78 }
79
80 } // namespace webrtc
81