Detect system architecture (x86/x64) while running

Question

Is it possible to detect the system/processor architecture while the program is running (under windows and under linux) in c++?

Answer 1

On Windows, you may use __cpuid. On Linux, you can open("/proc/cpuinfo") and look through it.

Here is an example on Windows, based on the example in the MSDN page:

#include <intrin.h>

bool cpuSupports64()
{
    int CPUInfo[4];
    __cpuid(CPUInfo, 0);
    return (CPUInfo[3] & 0x20000000) || false;
}