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] .
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.
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.
__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. …
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.
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 …
Introduction to RDTSC - Computer, Enhance!
WebJun 14, 2023 · Introduction to RDTSC. Originally a measurement of actual core cycles elapsed, RDTSC is now more like a wall clock timer than an instruction cycle timer. Share. This is the fourth video in Part 2 of the Performance-Aware Programming series. Please see the Table of Contents to quickly navigate through the rest of the course as it is updated …
Performance measurements with RDTSC - strchr.com
WebThe RDTSC instruction returns a 64-bit time stamp counter (TSC), which is increased on every clock cycle. It's the most precise counter available on x86 architecture. MSVC++ 2005 compiler supports a handy __rdtsc intrinsic that returns the result in 64-bit variable.
RDTSC—Read Time-Stamp Counter - GitHub Pages
WebDescription. 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 | 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.
Skip to content