1 /* 2 * Copyright (c) 2012 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 "common_audio/signal_processing/dot_product_with_scale.h" 12 13 #include "rtc_base/numerics/safe_conversions.h" 14 WebRtcSpl_DotProductWithScale(const int16_t * vector1,const int16_t * vector2,size_t length,int scaling)15int32_t WebRtcSpl_DotProductWithScale(const int16_t* vector1, 16 const int16_t* vector2, 17 size_t length, 18 int scaling) { 19 int64_t sum = 0; 20 size_t i = 0; 21 22 /* Unroll the loop to improve performance. */ 23 for (i = 0; i + 3 < length; i += 4) { 24 sum += (vector1[i + 0] * vector2[i + 0]) >> scaling; 25 sum += (vector1[i + 1] * vector2[i + 1]) >> scaling; 26 sum += (vector1[i + 2] * vector2[i + 2]) >> scaling; 27 sum += (vector1[i + 3] * vector2[i + 3]) >> scaling; 28 } 29 for (; i < length; i++) { 30 sum += (vector1[i] * vector2[i]) >> scaling; 31 } 32 33 return rtc::saturated_cast<int32_t>(sum); 34 } 35