// 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 "Timer.hpp"

#if defined(_WIN32)
	#ifndef WIN32_LEAN_AND_MEAN
		#define WIN32_LEAN_AND_MEAN
	#endif
	#include <windows.h>
#else
	#include <sys/time.h>
	#include <x86intrin.h>
#endif

namespace sw
{
	Timer::Timer()
	{
	}

	Timer::~Timer()
	{
	}

	double Timer::seconds()
	{
		#if defined(_WIN32)
			return (double)counter() / (double)frequency();
		#else
			timeval t;
			gettimeofday(&t, 0);
			return (double)t.tv_sec + (double)t.tv_usec * 1.0e-6;
		#endif
	}

	int64_t Timer::ticks()
	{
		#if defined(_WIN32)
			return __rdtsc();
		#else
			int64_t tsc;
			__asm volatile("rdtsc": "=A" (tsc));
			return tsc;
		#endif
	}

	int64_t Timer::counter()
	{
		#if defined(_WIN32)
			int64_t counter;
			QueryPerformanceCounter((LARGE_INTEGER*)&counter);
			return counter;
		#else
			timeval t;
			gettimeofday(&t, 0);
			return t.tv_sec * 1000000 + t.tv_usec;
		#endif
	}

	int64_t Timer::frequency()
	{
		#if defined(_WIN32)
			int64_t frequency;
			QueryPerformanceFrequency((LARGE_INTEGER*)&frequency);
			return frequency;
		#else
			return 1000000;   // gettimeofday uses microsecond resolution
		#endif
	}
}