__rdtsc | Microsoft Learn
WEBAug 3, 2021 · Syntax. Return value. Requirements. Remarks. Show 2 more. Microsoft Specific. Generates the rdtsc instruction, which returns the processor time stamp. The processor time stamp records the number of clock cycles since the last reset.
Time Stamp Counter - Wikipedia
WEBTime Stamp Counter. The Time Stamp Counter ( TSC) is a 64-bit register present on all x86 processors since the Pentium. It counts the number of CPU cycles since its reset. The instruction RDTSC returns the TSC in EDX:EAX. In x86-64 mode, RDTSC also clears the upper 32 bits of RAX and RDX. Its opcode is 0F 31. [1]
RDTSC — Read Time-Stamp Counter - felixcloutier.com
WEBThe time stamp disable (TSD) flag in register CR4 restricts the use of the RDTSC instruction as follows. When the flag is clear, the RDTSC instruction can be executed at any privilege level; when the flag is set, the instruction can only be executed at privilege level 0. The time-stamp counter can also be read with the RDMSR instruction, when ...
__rdtsc | Microsoft Learn
WEBこの記事の内容. 構文. 戻り値. 要件. 解説. さらに 2 個を表示. Microsoft 固有の仕様. プロセッサのタイムスタンプを返す rdtsc 命令を生成します。. プロセッサのタイムスタンプには、前回のリセットからのクロックサイクル数が記録されます。.
Difference between rdtscp, rdtsc : memory and cpuid / rdtsc?
WEBSep 28, 2012 · However, rdtscp is only available on newer CPUs. So in this case we have to use rdtsc. But rdtsc is non-serializing, so using it alone will not prevent the CPU from reordering it. So we can use either of these two options to prevent reordering: 2: This is a call to cpuid and then rdtsc. cpuid is a serializing call.
How to count clock cycles with RDTSC in GCC x86?
WEBrdtsc counts reference cycles, not CPU core clock cycles. It counts at a fixed frequency regardless of turbo / power-saving, so if you want uops-per-clock analysis, use performance counters. rdtsc is exactly correlated with wall-clock time (except for system clock adjustments, so it's basically steady_clock ).
Performance measurements with RDTSC - strchr.com
WEBIn the first case, the time will be measured with RDTSC in clock cycles. In the second case, it will be measured in seconds (you can even use GetTickCount for this case). > Microsoft recommends using QueryPerformanceCounter instead of RDTSC. Note that Microsoft does not recommend using RDTSC for game timing, not for performance measurements.
c - Best practice of using __rdtsc - Stack Overflow
WEBApr 20, 2023 · The normal state of affairs is the many instructions are in flight in the CPU's out-of-order execution machinery. Often what matters is the throughput cost of your code, not the end-to-end latency of a small snippet that the CPU can overlap with surrounding code. So anything like rdtscp(&dummy) or _mm_lfence(); __rdtsc() to wait for all earlier ...
WEBThe Intel time-stamp counter is a 64-bit MSR (model specific register) that is incremented every clock cycle. On reset, the time-stamp counter is set to zero. To access this counter, programmers can use the RDTSC (read time-stamp counter) instruction. This instruction loads the high-order 32 bits of the register into EDX, and the low-order 32 ...
X86-assembly/Instructions/rdtsc - aldeid
WEBNov 29, 2015 · The rdtsc (Read Time-Stamp Counter) instruction is used to determine how many CPU ticks took place since the processor was reset. Loads the current value of the processor's time-stamp counter into the EDX:EAX registers. It is commonly used as a timing defense (anti-debugging technique).
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