__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. …
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.
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.
RDTSC the only way to benchmark. - Medium
WEBAug 18, 2021. If you are benchmarking small single functions that denominate down to only a few lines of instructions or even just functions that complete execution in a very small amount of time...
Difference between rdtscp, rdtsc : memory and cpuid / rdtsc?
WEBSep 28, 2012 · 1: rdtscp is a serializing call. It prevents reordering around the call to rdtscp. __asm__ __volatile__("rdtscp; " // serializing read of tsc. "shl $32,%%rdx; " // shift higher 32 bits stored in rdx up. "or %%rdx,%%rax" // and or onto rax. : …
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.
GitHub - xuwd1/rdtsc-notes: notes and example codes on using rdtsc…
WEBStackoverflow thread. Intel's guide on benchmarking code with rdtsc (p) rdtscp reference. rdtsc reference. First glance. For measuring the execution time of work, the ideal case would be like the following: leading_code () startcycle = rdtsc () measured_code () endcycle = rdtsc () following_code () However things just won't work out this easy.
RDTSC—Read Time-Stamp Counter - GitHub Pages
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.
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.
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] .
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