/// @todo docs
void init_cpuinfo(cpuinfo::impl& info)
{
int registers[4];
/// According to the msvc docs eax, ebx, ecx and edx are
/// stored (in that order) in the array passed to the __cpuid
/// function.
// The register information per input can be extracted from here:
// http://en.wikipedia.org/wiki/CPUID
// CPUID should be called with EAX=0 first, as this will return the
// maximum supported EAX input value for future calls
__cpuid(registers, 0);
uint32_t maximum_eax = registers[0];
// Set registers for basic flag extraction, eax=1
// All CPUs should support index=1
if (maximum_eax >= 1U)
{
__cpuid(registers, 1);
extract_x86_flags(info, registers[2], registers[3]);
}
// Set registers for extended flags extraction, eax=7 and ecx=0
// This operation is not supported on older CPUs, so it should be skipped
// to avoid incorrect results
if (maximum_eax >= 7U)
{
__cpuidex(registers, 7, 0);
extract_x86_extended_flags(info, registers[1]);
}
}
/// @todo Document
void init_cpuinfo(cpuinfo::impl& info)
{
// Note: We need to capture these 4 registers, otherwise we get
// a segmentation fault on 32-bit Linux
uint32_t output[4];
// The register information per input can be extracted from here:
// http://en.wikipedia.org/wiki/CPUID
// Set registers for basic flag extraction
run_cpuid(1, 0, output);
extract_x86_flags(info, output[2], output[3]);
// Set registers for extended flags extraction
run_cpuid(7, 0, output);
extract_x86_extended_flags(info, output[1]);
}