__rdtsc | Microsoft Learn
WEBAug 2, 2021 · 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. Syntax. Copy. unsigned __int64 __rdtsc(); Return value. A 64-bit unsigned integer representing a tick count. …
RDTSC — Read Time-Stamp Counter - felixcloutier.com
WEBRDTSC — Read Time-Stamp Counter. Instruction Operand Encoding ¶. Description ¶. Reads the current value of the processor’s time-stamp counter (a 64-bit MSR) into the EDX:EAX registers. The EDX register is loaded with the high-order 32 bits of the MSR and the EAX register is loaded with the low-order 32 bits.
linux - Getting cpu cycles using RDTSC - Stack Overflow
WEBOct 21, 2016 · 20. I want to get the CPU cycles at a specific point. I use this function at that point: static __inline__ unsigned long long rdtsc(void) { unsigned long long int x; __asm__ volatile (".byte 0x0f, 0x31" : "=A" (x)); // broken for 64-bit builds; don't copy this code. return x; } (editor's note: "=A" is wrong for x86-64; it picks either RDX or RAX.
Difference between rdtscp, rdtsc : memory and cpuid / rdtsc?
WEBSep 28, 2012 · Save this question. Show activity on this post. Assume we're trying to use the tsc for performance monitoring and we we want to prevent instruction reordering. These are our options: 1: rdtscp is a serializing call. It prevents reordering around the call to rdtscp. __asm__ __volatile__("rdtscp; " // serializing read of tsc.
Time Stamp Counter - Wikipedia
WEBThe 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] .
measuring code execution times in C using RDTSC instruction
WEBAug 19, 2017 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. measuring code execution times in C using RDTSC instruction. Asked 8 years, 6 months ago. Modified 6 years, 8 months ago. Viewed 14k times. 4. I wrote a simple program to measure the code execution times using RDTSC instruction.
RDTSC | x86 Instruction Set Reference
WEBApr 18, 2019 · Description. Loads the current value of the processor's time-stamp counter into the EDX:EAX registers. The time-stamp counter is contained in a 64-bit MSR. The high-order 32 bits of the MSR are loaded into the EDX register, and the low-order 32 bits are loaded into the EAX register.
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). Opcode. 0F 31. Flags affected. None. Example.
RDTSCP — Read Time-Stamp Counter and Processor ID
WEBRDTSCP — Read Time-Stamp Counter and Processor ID. Instruction Operand Encoding ¶. Description ¶. Reads the current value of the processor’s time-stamp counter (a 64-bit MSR) into the EDX:EAX registers and also reads the value of the IA32_TSC_AUX MSR (address C0000103H) into the ECX register.
How to count clock cycles with RDTSC in GCC x86?
WEBHow to get the CPU cycle count in x86_64 from C++? (5 answers) Closed 5 years ago. With Visual Studio I can read the clock cycle count from the processor as shown below. How do I do the same thing with GCC? #ifdef _MSC_VER // Compiler: Microsoft Visual Studio. #ifdef _M_IX86 // Processor: x86.
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