1 files changed, 72 insertions, 0 deletions
diff --git a/chromium/third_party/webrtc/common_audio/fir_filter_neon.cc b/chromium/third_party/webrtc/common_audio/fir_filter_neon.cc
new file mode 100644
index 00000000000..97a75db0f27
--- /dev/null
+++ b/chromium/third_party/webrtc/common_audio/fir_filter_neon.cc
@@ -0,0 +1,72 @@
+/*
+ *  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 "webrtc/common_audio/fir_filter_neon.h"
+
+#include <arm_neon.h>
+#include <assert.h>
+#include <string.h>
+
+#include "webrtc/system_wrappers/interface/aligned_malloc.h"
+
+namespace webrtc {
+
+FIRFilterNEON::FIRFilterNEON(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.f, 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.f,
+         (max_input_length + state_length_) * sizeof(state_[0]));
+}
+
+void FIRFilterNEON::Filter(const float* in, size_t length, float* out) {
+  assert(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();
+
+    float32x4_t m_sum = vmovq_n_f32(0);
+    float32x4_t m_in;
+
+    for (size_t j = 0; j < coefficients_length_; j += 4) {
+       m_in = vld1q_f32(in_ptr + j);
+       m_sum = vmlaq_f32(m_sum, m_in, vld1q_f32(coef_ptr + j));
+    }
+
+    float32x2_t m_half = vadd_f32(vget_high_f32(m_sum), vget_low_f32(m_sum));
+    out[i] = vget_lane_f32(vpadd_f32(m_half, m_half), 0);
+  }
+
+  // Update current state.
+  memmove(state_.get(), &state_[length], state_length_ * sizeof(state_[0]));
+}
+
+}  // namespace webrtc