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