fast_math.h (1175B)
1 /* 2 * Copyright (c) 2019 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 #ifndef MODULES_AUDIO_PROCESSING_NS_FAST_MATH_H_ 12 #define MODULES_AUDIO_PROCESSING_NS_FAST_MATH_H_ 13 14 #include "api/array_view.h" 15 16 namespace webrtc { 17 18 // Sqrt approximation. 19 float SqrtFastApproximation(float f); 20 21 // Log base conversion log(x) = log2(x)/log2(e). 22 float LogApproximation(float x); 23 void LogApproximation(ArrayView<const float> x, ArrayView<float> y); 24 25 // 2^x approximation. 26 float Pow2Approximation(float p); 27 28 // x^p approximation. 29 float PowApproximation(float x, float p); 30 31 // e^x approximation. 32 float ExpApproximation(float x); 33 void ExpApproximation(ArrayView<const float> x, ArrayView<float> y); 34 void ExpApproximationSignFlip(ArrayView<const float> x, ArrayView<float> y); 35 } // namespace webrtc 36 37 #endif // MODULES_AUDIO_PROCESSING_NS_FAST_MATH_H_