libyuv/source/cpu_id.cc
mikhal@webrtc.org aed1cc94c1 first draft
git-svn-id: http://libyuv.googlecode.com/svn/trunk@2 16f28f9a-4ce2-e073-06de-1de4eb20be90
2011-09-28 00:06:25 +00:00

117 lines
3.1 KiB
C++

/*
* Copyright (c) 2011 The LibYuv project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "cpu_id.h"
#ifdef _MSC_VER
#include <intrin.h>
#elif LINUX
#include "linux.h"
#endif
// TODO(fbarchard): Use cpuid.h when gcc 4.4 is used on OSX and Linux.
#if (defined(__pic__) || defined(__APPLE__)) && defined(__i386__)
static inline void __cpuid(int cpu_info[4], int info_type) {
__asm__ volatile (
"mov %%ebx, %%edi\n"
"cpuid\n"
"xchg %%edi, %%ebx\n"
: "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
: "a"(info_type)
);
}
#elif defined(__i386__) || defined(__x86_64__)
static inline void __cpuid(int cpu_info[4], int info_type) {
__asm__ volatile (
"cpuid\n"
: "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
: "a"(info_type)
);
}
#endif
namespace libyuv {
// CPU detect function for SIMD instruction sets.
bool CpuInfo::cpu_info_initialized_ = false;
int CpuInfo::cpu_info_ = 0;
// Global lock for cpu initialization.
#ifdef CPU_X86
void cpuid(int cpu_info[4], int info_type) {
__cpuid(cpu_info, info_type);
}
#endif
void CpuInfo::InitCpuFlags() {
#ifdef CPU_X86
int cpu_info[4];
__cpuid(cpu_info, 1);
cpu_info_ = (cpu_info[2] & 0x00000200 ? kCpuHasSSSE3 : 0) |
(cpu_info[3] & 0x04000000 ? kCpuHasSSE2 : 0);
#elif defined(__ARM_NEON__)
// gcc -mfpu=neon defines __ARM_NEON__
// if code is specifically built for Neon-only, enable the flag.
cpu_info_ |= kCpuHasNEON;
#elif LINUX && defined(__arm__)
cpu_info_ = 0;
// Look for NEON support in /proc/cpuinfo
ProcCpuInfo proc_info;
size_t section_count;
if (proc_info.LoadFromSystem() &&
proc_info.GetSectionCount(&section_count)) {
for (size_t i = 0; i < section_count; ++i) {
std::string out_features;
if (proc_info.GetSectionStringValue(i, "Features", &out_features)) {
if (out_features.find("neon") != std::string::npos) {
cpu_info_ |= kCpuHasNEON;
}
break;
}
}
}
#else
cpu_info_ = 0;
#endif
cpu_info_initialized_ = true;
}
void CpuInfo::MaskCpuFlagsForTest(int enable_flags) {
InitCpuFlags();
cpu_info_ &= enable_flags;
}
bool CpuInfo::TestCpuFlag(int flag) {
if (!cpu_info_initialized_) {
InitCpuFlags();
}
return cpu_info_ & flag ? true : false;
}
// Returns the vendor string from the cpu, e.g. "GenuineIntel", "AuthenticAMD".
// See "Intel Processor Identification and the CPUID Instruction"
// (Intel document number: 241618)
std::string CpuInfo::GetCpuVendor() {
#ifdef CPU_X86
int cpu_info[4];
cpuid(cpu_info, 0);
cpu_info[0] = cpu_info[1]; // Reorder output
cpu_info[1] = cpu_info[3];
cpu_info[2] = cpu_info[2];
cpu_info[3] = 0;
return std::string(reinterpret_cast<char *>(&cpu_info[0]));
#else
return std::string("Undefined");
#endif
}
} // namespace libyuv