Bullet Collision Detection & Physics Library: btCpuFeatureUtility.h Source File

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btCpuFeatureUtility.h
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1
2 #ifndef BT_CPU_UTILITY_H
3 #define BT_CPU_UTILITY_H
4
5 #include "LinearMath/btScalar.h"
6
7 #include <string.h>//memset
8 #ifdef USE_SIMD
9 #include <emmintrin.h>
10 #ifdef BT_ALLOW_SSE4
11 #include <intrin.h>
12 #endif //BT_ALLOW_SSE4
13 #endif //USE_SIMD
14
15 #if defined BT_USE_NEON
16 #define ARM_NEON_GCC_COMPATIBILITY 1
17 #include <arm_neon.h>
18 #include <sys/types.h>
19 #include <sys/sysctl.h> //for sysctlbyname
20 #endif //BT_USE_NEON
21
24 class btCpuFeatureUtility
25 {
26 public:
27 enum btCpuFeature
28 {
29 CPU_FEATURE_FMA3=1,
30 CPU_FEATURE_SSE4_1=2,
31 CPU_FEATURE_NEON_HPFP=4
32 };
33
34 static int getCpuFeatures()
35 {
36
37 static int capabilities = 0;
38 static bool testedCapabilities = false;
39 if (0 != testedCapabilities)
40 {
41 return capabilities;
42 }
43
44 #ifdef BT_USE_NEON
45 {
46 uint32_t hasFeature = 0;
47 size_t featureSize = sizeof(hasFeature);
48 int err = sysctlbyname("hw.optional.neon_hpfp", &hasFeature, &featureSize, NULL, 0);
49 if (0 == err && hasFeature)
50 capabilities |= CPU_FEATURE_NEON_HPFP;
51 }
52 #endif //BT_USE_NEON
53
54 #ifdef BT_ALLOW_SSE4
55 {
56 int cpuInfo[4];
57 memset(cpuInfo, 0, sizeof(cpuInfo));
58 unsigned long long sseExt = 0;
59 __cpuid(cpuInfo, 1);
60
61 bool osUsesXSAVE_XRSTORE = cpuInfo[2] & (1 << 27) || false;
62 bool cpuAVXSuport = cpuInfo[2] & (1 << 28) || false;
63
64 if (osUsesXSAVE_XRSTORE && cpuAVXSuport)
65 {
66 sseExt = _xgetbv(0);
67 }
68 const int OSXSAVEFlag = (1UL << 27);
69 const int AVXFlag = ((1UL << 28) | OSXSAVEFlag);
70 const int FMAFlag = ((1UL << 12) | AVXFlag | OSXSAVEFlag);
71 if ((cpuInfo[2] & FMAFlag) == FMAFlag && (sseExt & 6) == 6)
72 {
73 capabilities |= btCpuFeatureUtility::CPU_FEATURE_FMA3;
74 }
75
76 const int SSE41Flag = (1 << 19);
77 if (cpuInfo[2] & SSE41Flag)
78 {
79 capabilities |= btCpuFeatureUtility::CPU_FEATURE_SSE4_1;
80 }
81 }
82 #endif//BT_ALLOW_SSE4
83
84 testedCapabilities = true;
85 return capabilities;
86 }
87
88
89 };
90
91
92 #endif //BT_CPU_UTILITY_H
btCpuFeatureUtility::getCpuFeatures
static int getCpuFeatures()
Definition: btCpuFeatureUtility.h:34
uint32_t
unsigned int uint32_t
Definition: btConvexHullComputer.cpp:32
btCpuFeatureUtility
Rudimentary btCpuFeatureUtility for CPU features: only report the features that Bullet actually uses ...
Definition: btCpuFeatureUtility.h:24
btCpuFeatureUtility::CPU_FEATURE_NEON_HPFP
Definition: btCpuFeatureUtility.h:31
btCpuFeatureUtility::CPU_FEATURE_SSE4_1
Definition: btCpuFeatureUtility.h:30
btCpuFeatureUtility::btCpuFeature
btCpuFeature
Definition: btCpuFeatureUtility.h:27
btCpuFeatureUtility::CPU_FEATURE_FMA3
Definition: btCpuFeatureUtility.h:29
btScalar.h