1 files changed, 92 insertions, 0 deletions
diff --git a/extern/bullet2/src/LinearMath/btCpuFeatureUtility.h b/extern/bullet2/src/LinearMath/btCpuFeatureUtility.h
new file mode 100644
index 00000000000..d2cab52d488
--- /dev/null
+++ b/extern/bullet2/src/LinearMath/btCpuFeatureUtility.h
@@ -0,0 +1,92 @@
+
+#ifndef BT_CPU_UTILITY_H
+#define BT_CPU_UTILITY_H
+
+#include "LinearMath/btScalar.h"
+
+#include <string.h>//memset
+#ifdef  USE_SIMD
+#include <emmintrin.h>
+#ifdef BT_ALLOW_SSE4
+#include <intrin.h>
+#endif //BT_ALLOW_SSE4
+#endif //USE_SIMD
+
+#if defined BT_USE_NEON
+#define ARM_NEON_GCC_COMPATIBILITY  1
+#include <arm_neon.h>
+#include <sys/types.h>
+#include <sys/sysctl.h> //for sysctlbyname
+#endif //BT_USE_NEON
+
+///Rudimentary btCpuFeatureUtility for CPU features: only report the features that Bullet actually uses (SSE4/FMA3, NEON_HPFP)
+///We assume SSE2 in case BT_USE_SSE2 is defined in LinearMath/btScalar.h
+class btCpuFeatureUtility
+{
+public:
+	enum btCpuFeature
+	{
+		CPU_FEATURE_FMA3=1,
+		CPU_FEATURE_SSE4_1=2,
+		CPU_FEATURE_NEON_HPFP=4
+	};
+
+	static int getCpuFeatures()
+	{
+
+		static int capabilities = 0;
+		static bool testedCapabilities = false;
+		if (0 != testedCapabilities)
+		{
+			return capabilities;
+		}
+
+#ifdef BT_USE_NEON
+		{
+			uint32_t hasFeature = 0;
+			size_t featureSize = sizeof(hasFeature);
+			int err = sysctlbyname("hw.optional.neon_hpfp", &hasFeature, &featureSize, NULL, 0);
+			if (0 == err && hasFeature)
+				capabilities |= CPU_FEATURE_NEON_HPFP;
+		}
+#endif //BT_USE_NEON
+
+#ifdef  BT_ALLOW_SSE4
+		{
+			int					cpuInfo[4];
+			memset(cpuInfo, 0, sizeof(cpuInfo));
+			unsigned long long	sseExt = 0;
+			__cpuid(cpuInfo, 1);
+			
+			bool osUsesXSAVE_XRSTORE = cpuInfo[2] & (1 << 27) || false;
+			bool cpuAVXSuport = cpuInfo[2] & (1 << 28) || false;
+
+			if (osUsesXSAVE_XRSTORE && cpuAVXSuport)
+			{
+				sseExt = _xgetbv(0);
+			}
+			const int OSXSAVEFlag = (1UL << 27);
+			const int AVXFlag = ((1UL << 28) | OSXSAVEFlag);
+			const int FMAFlag = ((1UL << 12) | AVXFlag | OSXSAVEFlag);
+			if ((cpuInfo[2] & FMAFlag) == FMAFlag && (sseExt & 6) == 6)
+			{
+				capabilities |= btCpuFeatureUtility::CPU_FEATURE_FMA3;
+			}
+
+			const int SSE41Flag = (1 << 19);
+			if (cpuInfo[2] & SSE41Flag)
+			{
+				capabilities |= btCpuFeatureUtility::CPU_FEATURE_SSE4_1;
+			}
+		}
+#endif//BT_ALLOW_SSE4
+
+		testedCapabilities = true;
+		return capabilities;
+	}
+
+
+};
+
+
+#endif //BT_CPU_UTILITY_H