// Copyright (C) 2015 Alexandre Janniaux
// This file is part of the "Nazara Engine - Core module"
// For conditions of distribution and use, see copyright notice in Config.hpp

#include <Nazara/Core/Posix/HardwareInfoImpl.hpp>
#include <Nazara/Core/Error.hpp>
#include <Nazara/Core/Debug.hpp>

void NzHardwareInfoImpl::Cpuid(nzUInt32 code, nzUInt32 result[4])
{
	#if defined(NAZARA_COMPILER_CLANG) || defined(NAZARA_COMPILER_GCC) || defined(NAZARA_COMPILER_INTEL)
	// Source: http://stackoverflow.com/questions/1666093/cpuid-implementations-in-c
	asm volatile ("cpuid" // Besoin d'être volatile ?
				  : "=a" (result[0]), "=b" (result[1]), "=c" (result[2]), "=d" (result[3]) // output
                  : "a" (code), "c" (0));                                                  // input
	#else
	NazaraInternalError("Cpuid has been called although it is not supported");
	#endif
}

unsigned int NzHardwareInfoImpl::GetProcessorCount()
{
	// Plus simple (et plus portable) que de passer par le CPUID
	return sysconf(_SC_NPROCESSORS_CONF);
}

bool NzHardwareInfoImpl::IsCpuidSupported()
{
	#ifdef NAZARA_PLATFORM_x64
	return true; // Toujours supporté sur un processeur 64 bits
	#else
		#if defined(NAZARA_COMPILER_CLANG) || defined(NAZARA_COMPILER_GCC) || defined(NAZARA_COMPILER_INTEL)
		int supported;
		asm volatile ("	pushfl\n"
					  "	pop %%eax\n"
					  "	mov %%eax, %%ecx\n"
					  "	xor $0x200000, %%eax\n"
					  "	push %%eax\n"
					  "	popfl\n"
					  "	pushfl\n"
					  "	pop %%eax\n"
					  "	xor %%ecx, %%eax\n"
					  "	mov %%eax, %0\n"
					  "	push %%ecx\n"
					  "	popfl"
					  : "=m" (supported)         // output
					  :                          // input
					  : "eax", "ecx", "memory"); // clobbered register

		return supported != 0;
		#else
		return false;
		#endif
	#endif
}
