diff options
Diffstat (limited to 'third_party/libwebrtc/common_audio/fir_filter_sse.cc')
-rw-r--r-- | third_party/libwebrtc/common_audio/fir_filter_sse.cc | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/third_party/libwebrtc/common_audio/fir_filter_sse.cc b/third_party/libwebrtc/common_audio/fir_filter_sse.cc new file mode 100644 index 0000000000..0e45994a1d --- /dev/null +++ b/third_party/libwebrtc/common_audio/fir_filter_sse.cc @@ -0,0 +1,82 @@ +/* + * Copyright (c) 2014 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#include "common_audio/fir_filter_sse.h" + +#include <stdint.h> +#include <string.h> +#include <xmmintrin.h> + +#include "rtc_base/checks.h" +#include "rtc_base/memory/aligned_malloc.h" + +namespace webrtc { + +FIRFilterSSE2::~FIRFilterSSE2() {} + +FIRFilterSSE2::FIRFilterSSE2(const float* coefficients, + size_t coefficients_length, + size_t max_input_length) + : // Closest higher multiple of four. + coefficients_length_((coefficients_length + 3) & ~0x03), + state_length_(coefficients_length_ - 1), + coefficients_(static_cast<float*>( + AlignedMalloc(sizeof(float) * coefficients_length_, 16))), + state_(static_cast<float*>( + AlignedMalloc(sizeof(float) * (max_input_length + state_length_), + 16))) { + // Add zeros at the end of the coefficients. + size_t padding = coefficients_length_ - coefficients_length; + memset(coefficients_.get(), 0, padding * sizeof(coefficients_[0])); + // The coefficients are reversed to compensate for the order in which the + // input samples are acquired (most recent last). + for (size_t i = 0; i < coefficients_length; ++i) { + coefficients_[i + padding] = coefficients[coefficients_length - i - 1]; + } + memset(state_.get(), 0, + (max_input_length + state_length_) * sizeof(state_[0])); +} + +void FIRFilterSSE2::Filter(const float* in, size_t length, float* out) { + RTC_DCHECK_GT(length, 0); + + memcpy(&state_[state_length_], in, length * sizeof(*in)); + + // Convolves the input signal `in` with the filter kernel `coefficients_` + // taking into account the previous state. + for (size_t i = 0; i < length; ++i) { + float* in_ptr = &state_[i]; + float* coef_ptr = coefficients_.get(); + + __m128 m_sum = _mm_setzero_ps(); + __m128 m_in; + + // Depending on if the pointer is aligned with 16 bytes or not it is loaded + // differently. + if (reinterpret_cast<uintptr_t>(in_ptr) & 0x0F) { + for (size_t j = 0; j < coefficients_length_; j += 4) { + m_in = _mm_loadu_ps(in_ptr + j); + m_sum = _mm_add_ps(m_sum, _mm_mul_ps(m_in, _mm_load_ps(coef_ptr + j))); + } + } else { + for (size_t j = 0; j < coefficients_length_; j += 4) { + m_in = _mm_load_ps(in_ptr + j); + m_sum = _mm_add_ps(m_sum, _mm_mul_ps(m_in, _mm_load_ps(coef_ptr + j))); + } + } + m_sum = _mm_add_ps(_mm_movehl_ps(m_sum, m_sum), m_sum); + _mm_store_ss(out + i, _mm_add_ss(m_sum, _mm_shuffle_ps(m_sum, m_sum, 1))); + } + + // Update current state. + memmove(state_.get(), &state_[length], state_length_ * sizeof(state_[0])); +} + +} // namespace webrtc |