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 /* The global function contained in this file initializes SPL function
12  * pointers, currently only for ARM platforms.
13  *
14  * Some code came from common/rtcd.c in the WebM project.
15  */
16 
17 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
18 #include "webrtc/system_wrappers/include/cpu_features_wrapper.h"
19 
20 /* Declare function pointers. */
21 MaxAbsValueW16 WebRtcSpl_MaxAbsValueW16;
22 MaxAbsValueW32 WebRtcSpl_MaxAbsValueW32;
23 MaxValueW16 WebRtcSpl_MaxValueW16;
24 MaxValueW32 WebRtcSpl_MaxValueW32;
25 MinValueW16 WebRtcSpl_MinValueW16;
26 MinValueW32 WebRtcSpl_MinValueW32;
27 CrossCorrelation WebRtcSpl_CrossCorrelation;
28 DownsampleFast WebRtcSpl_DownsampleFast;
29 ScaleAndAddVectorsWithRound WebRtcSpl_ScaleAndAddVectorsWithRound;
30 
31 #if (defined(WEBRTC_DETECT_NEON) || !defined(WEBRTC_HAS_NEON)) && \
32     !defined(MIPS32_LE)
33 /* Initialize function pointers to the generic C version. */
InitPointersToC()34 static void InitPointersToC() {
35   WebRtcSpl_MaxAbsValueW16 = WebRtcSpl_MaxAbsValueW16C;
36   WebRtcSpl_MaxAbsValueW32 = WebRtcSpl_MaxAbsValueW32C;
37   WebRtcSpl_MaxValueW16 = WebRtcSpl_MaxValueW16C;
38   WebRtcSpl_MaxValueW32 = WebRtcSpl_MaxValueW32C;
39   WebRtcSpl_MinValueW16 = WebRtcSpl_MinValueW16C;
40   WebRtcSpl_MinValueW32 = WebRtcSpl_MinValueW32C;
41   WebRtcSpl_CrossCorrelation = WebRtcSpl_CrossCorrelationC;
42   WebRtcSpl_DownsampleFast = WebRtcSpl_DownsampleFastC;
43   WebRtcSpl_ScaleAndAddVectorsWithRound =
44       WebRtcSpl_ScaleAndAddVectorsWithRoundC;
45 }
46 #endif
47 
48 #if defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON)
49 /* Initialize function pointers to the Neon version. */
InitPointersToNeon()50 static void InitPointersToNeon() {
51   WebRtcSpl_MaxAbsValueW16 = WebRtcSpl_MaxAbsValueW16Neon;
52   WebRtcSpl_MaxAbsValueW32 = WebRtcSpl_MaxAbsValueW32Neon;
53   WebRtcSpl_MaxValueW16 = WebRtcSpl_MaxValueW16Neon;
54   WebRtcSpl_MaxValueW32 = WebRtcSpl_MaxValueW32Neon;
55   WebRtcSpl_MinValueW16 = WebRtcSpl_MinValueW16Neon;
56   WebRtcSpl_MinValueW32 = WebRtcSpl_MinValueW32Neon;
57   WebRtcSpl_CrossCorrelation = WebRtcSpl_CrossCorrelationNeon;
58   WebRtcSpl_DownsampleFast = WebRtcSpl_DownsampleFastNeon;
59   WebRtcSpl_ScaleAndAddVectorsWithRound =
60       WebRtcSpl_ScaleAndAddVectorsWithRoundC;
61 }
62 #endif
63 
64 #if defined(MIPS32_LE)
65 /* Initialize function pointers to the MIPS version. */
InitPointersToMIPS()66 static void InitPointersToMIPS() {
67   WebRtcSpl_MaxAbsValueW16 = WebRtcSpl_MaxAbsValueW16_mips;
68   WebRtcSpl_MaxValueW16 = WebRtcSpl_MaxValueW16_mips;
69   WebRtcSpl_MaxValueW32 = WebRtcSpl_MaxValueW32_mips;
70   WebRtcSpl_MinValueW16 = WebRtcSpl_MinValueW16_mips;
71   WebRtcSpl_MinValueW32 = WebRtcSpl_MinValueW32_mips;
72   WebRtcSpl_CrossCorrelation = WebRtcSpl_CrossCorrelation_mips;
73   WebRtcSpl_DownsampleFast = WebRtcSpl_DownsampleFast_mips;
74 #if defined(MIPS_DSP_R1_LE)
75   WebRtcSpl_MaxAbsValueW32 = WebRtcSpl_MaxAbsValueW32_mips;
76   WebRtcSpl_ScaleAndAddVectorsWithRound =
77       WebRtcSpl_ScaleAndAddVectorsWithRound_mips;
78 #else
79   WebRtcSpl_MaxAbsValueW32 = WebRtcSpl_MaxAbsValueW32C;
80   WebRtcSpl_ScaleAndAddVectorsWithRound =
81       WebRtcSpl_ScaleAndAddVectorsWithRoundC;
82 #endif
83 }
84 #endif
85 
InitFunctionPointers(void)86 static void InitFunctionPointers(void) {
87 #if defined(WEBRTC_DETECT_NEON)
88   if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
89     InitPointersToNeon();
90   } else {
91     InitPointersToC();
92   }
93 #elif defined(WEBRTC_HAS_NEON)
94   InitPointersToNeon();
95 #elif defined(MIPS32_LE)
96   InitPointersToMIPS();
97 #else
98   InitPointersToC();
99 #endif  /* WEBRTC_DETECT_NEON */
100 }
101 
102 #if defined(WEBRTC_POSIX)
103 #include <pthread.h>
104 
once(void (* func)(void))105 static void once(void (*func)(void)) {
106   static pthread_once_t lock = PTHREAD_ONCE_INIT;
107   pthread_once(&lock, func);
108 }
109 
110 #elif defined(_WIN32)
111 #include <windows.h>
112 
once(void (* func)(void))113 static void once(void (*func)(void)) {
114   /* Didn't use InitializeCriticalSection() since there's no race-free context
115    * in which to execute it.
116    *
117    * TODO(kma): Change to different implementation (e.g.
118    * InterlockedCompareExchangePointer) to avoid issues similar to
119    * http://code.google.com/p/webm/issues/detail?id=467.
120    */
121   static CRITICAL_SECTION lock = {(void *)((size_t)-1), -1, 0, 0, 0, 0};
122   static int done = 0;
123 
124   EnterCriticalSection(&lock);
125   if (!done) {
126     func();
127     done = 1;
128   }
129   LeaveCriticalSection(&lock);
130 }
131 
132 /* There's no fallback version as an #else block here to ensure thread safety.
133  * In case of neither pthread for WEBRTC_POSIX nor _WIN32 is present, build
134  * system should pick it up.
135  */
136 #endif  /* WEBRTC_POSIX */
137 
WebRtcSpl_Init()138 void WebRtcSpl_Init() {
139   once(InitFunctionPointers);
140 }
141