Adding new functionality for SIMD optimizations in AEC3

webrtc/modules/audio_processing/aec3/vector_math.h

Index: webrtc/modules/audio_processing/aec3/vector_math.h
diff --git a/webrtc/modules/audio_processing/aec3/vector_math.h b/webrtc/modules/audio_processing/aec3/vector_math.h
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+/*
+ *  Copyright (c) 2017 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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_VECTOR_MATH_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_VECTOR_MATH_H_
+
+#include "webrtc/typedefs.h"
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+#include <emmintrin.h>
+#endif
+#include <math.h>
+#include <algorithm>
+#include <array>
+#include <functional>
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
+
+namespace webrtc {
+namespace aec3 {
+
+// Provides optimizations for mathematical operations based on vectors.
+class VectorMath {
+ public:
+  explicit VectorMath(Aec3Optimization optimization)
+      : optimization_(optimization) {}
+
+  // Elementwise square root.
+  void Sqrt(rtc::ArrayView<float> x) {
+    switch (optimization_) {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+      case Aec3Optimization::kSse2: {
+        const int x_size = static_cast<int>(x.size());
+        const int vector_limit = x_size >> 2;
+
+        int j = 0;
+        for (; j < vector_limit * 4; j += 4) {
+          __m128 g = _mm_loadu_ps(&x[j]);
+          g = _mm_sqrt_ps(g);
+          _mm_storeu_ps(&x[j], g);
+        }
+
+        for (; j < x_size; ++j) {
+          x[j] = sqrtf(x[j]);
+        }
+      } break;
+#endif
+      default:
+        std::for_each(x.begin(), x.end(), [](float& a) { a = sqrtf(a); });
+    }
+  }
+
+  // Elementwise vector multiplication z = x * y.
+  void Multiply(rtc::ArrayView<const float> x,
+                rtc::ArrayView<const float> y,
+                rtc::ArrayView<float> z) {
+    RTC_DCHECK_EQ(z.size(), x.size());
+    RTC_DCHECK_EQ(z.size(), y.size());
+    switch (optimization_) {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+      case Aec3Optimization::kSse2: {
+        const int x_size = static_cast<int>(x.size());
+        const int vector_limit = x_size >> 2;
+
+        int j = 0;
+        for (; j < vector_limit * 4; j += 4) {
+          const __m128 x_j = _mm_loadu_ps(&x[j]);
+          const __m128 y_j = _mm_loadu_ps(&y[j]);
+          const __m128 z_j = _mm_mul_ps(x_j, y_j);
+          _mm_storeu_ps(&z[j], z_j);
+        }
+
+        for (; j < x_size; ++j) {
+          z[j] = x[j] * y[j];
+        }
+      } break;
+#endif
+      default:
+        std::transform(x.begin(), x.end(), y.begin(), z.begin(),
+                       std::multiplies<float>());
+    }
+  }
+
+  // Elementwise vector accumulation z += x.
+  void Accumulate(rtc::ArrayView<const float> x, rtc::ArrayView<float> z) {
+    RTC_DCHECK_EQ(z.size(), x.size());
+    switch (optimization_) {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+      case Aec3Optimization::kSse2: {
+        const int x_size = static_cast<int>(x.size());
+        const int vector_limit = x_size >> 2;
+
+        int j = 0;
+        for (; j < vector_limit * 4; j += 4) {
+          const __m128 x_j = _mm_loadu_ps(&x[j]);
+          __m128 z_j = _mm_loadu_ps(&z[j]);
+          z_j = _mm_add_ps(x_j, z_j);
+          _mm_storeu_ps(&z[j], z_j);
+        }
+
+        for (; j < x_size; ++j) {
+          z[j] += x[j];
+        }
+      } break;
+#endif
+      default:
+        std::transform(x.begin(), x.end(), z.begin(), z.begin(),
+                       std::plus<float>());
+    }
+  }
+
+ private:
+  Aec3Optimization optimization_;
+};
+
+}  // namespace aec3
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_VECTOR_MATH_H_