Source/Timing/timestamp.h


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//-----------------------------------------------------------------------------
//           Name: timestamp.h
//      Developer: Wolfire Games LLC
//         Author: Micah J Best
//           Date: Thursday, April 1, 2016
//    Description: Lightweight timing tools
//        License: Read below
//-----------------------------------------------------------------------------
//
//   Copyright 2022 Wolfire Games LLC
//
//   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.
//
//-----------------------------------------------------------------------------
#pragma once

inline uint64_t GetTimestamp() {
        // Use rdtsc instruction to get the tsc or Time Stamp Counter
#if (defined(PLATFORM_LINUX) || defined(PLATFORM_MACOSX)) && (defined(__i386__) || defined(__x86_64__))
        uint32_t rax, rdx;
        asm volatile ( "lfence" ::: "memory" ); //Fence memory load to everything is executed up to this point.
        asm volatile ( "rdtsc\n" : "=a" (rax), "=d" (rdx) : : );
        return ((uint64_t)rdx << 32) + rax;
#elif defined(PLATFORM_WINDOWS) && _MSC_VER >= 1600 
        unsigned __int64 i;
        _ReadBarrier();
        i = __rdtsc();
        return (uint64_t)i;
#else

#error "No timer implementation for current target platform"

#endif
}