// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "CPUID.hpp"

#if defined(_WIN32)
	#ifndef WIN32_LEAN_AND_MEAN
		#define WIN32_LEAN_AND_MEAN
	#endif
	#include <windows.h>
	#include <intrin.h>
	#include <float.h>
#else
	#include <unistd.h>
	#include <sched.h>
	#include <sys/types.h>
#endif

namespace sw {

bool CPUID::MMX = detectMMX();
bool CPUID::CMOV = detectCMOV();
bool CPUID::SSE = detectSSE();
bool CPUID::SSE2 = detectSSE2();
bool CPUID::SSE3 = detectSSE3();
bool CPUID::SSSE3 = detectSSSE3();
bool CPUID::SSE4_1 = detectSSE4_1();
int CPUID::cores = detectCoreCount();
int CPUID::affinity = detectAffinity();

bool CPUID::enableMMX = true;
bool CPUID::enableCMOV = true;
bool CPUID::enableSSE = true;
bool CPUID::enableSSE2 = true;
bool CPUID::enableSSE3 = true;
bool CPUID::enableSSSE3 = true;
bool CPUID::enableSSE4_1 = true;

void CPUID::setEnableMMX(bool enable)
{
	enableMMX = enable;

	if(!enableMMX)
	{
		enableSSE = false;
		enableSSE2 = false;
		enableSSE3 = false;
		enableSSSE3 = false;
		enableSSE4_1 = false;
	}
}

void CPUID::setEnableCMOV(bool enable)
{
	enableCMOV = enable;

	if(!CMOV)
	{
		enableSSE = false;
		enableSSE2 = false;
		enableSSE3 = false;
		enableSSSE3 = false;
		enableSSE4_1 = false;
	}
}

void CPUID::setEnableSSE(bool enable)
{
	enableSSE = enable;

	if(enableSSE)
	{
		enableMMX = true;
		enableCMOV = true;
	}
	else
	{
		enableSSE2 = false;
		enableSSE3 = false;
		enableSSSE3 = false;
		enableSSE4_1 = false;
	}
}

void CPUID::setEnableSSE2(bool enable)
{
	enableSSE2 = enable;

	if(enableSSE2)
	{
		enableMMX = true;
		enableCMOV = true;
		enableSSE = true;
	}
	else
	{
		enableSSE3 = false;
		enableSSSE3 = false;
		enableSSE4_1 = false;
	}
}

void CPUID::setEnableSSE3(bool enable)
{
	enableSSE3 = enable;

	if(enableSSE3)
	{
		enableMMX = true;
		enableCMOV = true;
		enableSSE = true;
		enableSSE2 = true;
	}
	else
	{
		enableSSSE3 = false;
		enableSSE4_1 = false;
	}
}

void CPUID::setEnableSSSE3(bool enable)
{
	enableSSSE3 = enable;

	if(enableSSSE3)
	{
		enableMMX = true;
		enableCMOV = true;
		enableSSE = true;
		enableSSE2 = true;
		enableSSE3 = true;
	}
	else
	{
		enableSSE4_1 = false;
	}
}

void CPUID::setEnableSSE4_1(bool enable)
{
	enableSSE4_1 = enable;

	if(enableSSE4_1)
	{
		enableMMX = true;
		enableCMOV = true;
		enableSSE = true;
		enableSSE2 = true;
		enableSSE3 = true;
		enableSSSE3 = true;
	}
}

static void cpuid(int registers[4], int info)
{
	#if defined(__i386__) || defined(__x86_64__)
		#if defined(_WIN32)
			__cpuid(registers, info);
		#else
			__asm volatile("cpuid": "=a" (registers[0]), "=b" (registers[1]), "=c" (registers[2]), "=d" (registers[3]): "a" (info));
		#endif
	#else
		registers[0] = 0;
		registers[1] = 0;
		registers[2] = 0;
		registers[3] = 0;
	#endif
}

bool CPUID::detectMMX()
{
	int registers[4];
	cpuid(registers, 1);
	return MMX = (registers[3] & 0x00800000) != 0;
}

bool CPUID::detectCMOV()
{
	int registers[4];
	cpuid(registers, 1);
	return CMOV = (registers[3] & 0x00008000) != 0;
}

bool CPUID::detectSSE()
{
	int registers[4];
	cpuid(registers, 1);
	return SSE = (registers[3] & 0x02000000) != 0;
}

bool CPUID::detectSSE2()
{
	int registers[4];
	cpuid(registers, 1);
	return SSE2 = (registers[3] & 0x04000000) != 0;
}

bool CPUID::detectSSE3()
{
	int registers[4];
	cpuid(registers, 1);
	return SSE3 = (registers[2] & 0x00000001) != 0;
}

bool CPUID::detectSSSE3()
{
	int registers[4];
	cpuid(registers, 1);
	return SSSE3 = (registers[2] & 0x00000200) != 0;
}

bool CPUID::detectSSE4_1()
{
	int registers[4];
	cpuid(registers, 1);
	return SSE4_1 = (registers[2] & 0x00080000) != 0;
}

int CPUID::detectCoreCount()
{
	int cores = 0;

	#if defined(_WIN32)
		DWORD_PTR processAffinityMask = 1;
		DWORD_PTR systemAffinityMask = 1;

		GetProcessAffinityMask(GetCurrentProcess(), &processAffinityMask, &systemAffinityMask);

		while(systemAffinityMask)
		{
			if(systemAffinityMask & 1)
			{
				cores++;
			}

			systemAffinityMask >>= 1;
		}
	#else
		cores = sysconf(_SC_NPROCESSORS_ONLN);
	#endif

	if(cores < 1)  cores = 1;
	if(cores > 16) cores = 16;

	return cores;   // FIXME: Number of physical cores
}

int CPUID::detectAffinity()
{
	int cores = 0;

	#if defined(_WIN32)
		DWORD_PTR processAffinityMask = 1;
		DWORD_PTR systemAffinityMask = 1;

		GetProcessAffinityMask(GetCurrentProcess(), &processAffinityMask, &systemAffinityMask);

		while(processAffinityMask)
		{
			if(processAffinityMask & 1)
			{
				cores++;
			}

			processAffinityMask >>= 1;
		}
	#else
		return detectCoreCount();   // FIXME: Assumes no affinity limitation
	#endif

	if(cores < 1)  cores = 1;
	if(cores > 16) cores = 16;

	return cores;
}

void CPUID::setFlushToZero(bool enable)
{
	#if defined(_MSC_VER)
		_controlfp(enable ? _DN_FLUSH : _DN_SAVE, _MCW_DN);
	#else
		// Unimplemented
	#endif
}

void CPUID::setDenormalsAreZero(bool enable)
{
	// Unimplemented
}

}  // namespace sw