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Testing Inline ASM-VB
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Using inline ASM
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Files Visual Basic
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Testing Inline ASM-VB
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Using inline ASM
Submit!
Accessing the high performance counterThe Performance Counter is a very high 64bit resolution counter
It's been in processors since the Intel 386. Note though, it doesn't return time.
It returns ticks (cycles)! To calculate it back to time you have to divide the ticks with the tick frequency of your computer. (you could use the queryperformancecounter API for it)
Most of the time you will only use the lower 32 bits. (the upper 32 bits are for long numbers only)
User contributed notes:
It's been in processors since the Intel 386. Note though, it doesn't return time.
It returns ticks (cycles)! To calculate it back to time you have to divide the ticks with the tick frequency of your computer. (you could use the queryperformancecounter API for it)
Most of the time you will only use the lower 32 bits. (the upper 32 bits are for long numbers only)
'//How-to use: This function returns the amounts of *ticks* in a 64bit number '//You can simply use the CyclesLow for most measurements (which don't take too long) '// '// Dim lngCyclesHighStart As Long, lngCyclesLowStart As Long '// Dim lngCyclesHighStop As Long, lngCyclesLowStop As Long '// '// Call MAsmCode.asmProcessorPerformance(lngCyclesHighStart, lngCyclesLowStart) '// '// '//Do something '// '// Call asmProcessorPerformance(lngCyclesHighStop, lngCyclesLowStop) '// '// Debug.Print = (lngCyclesLowStop - lngCyclesLowStart) '// '//Note: To convert to ms/ns, you'll need the frequency of the cpu. Public Sub asmProcessorPerformance(ByRef CyclesHigh As Long, ByRef CyclesLow As Long) '#ASM_START '.586 ' push ebp ' mov ebp, esp ' push edx ' push ecx ' push edi ' ' mov ecx, 0 ' RDTSC ' mov edi, DWORD PTR [ebp+8] ' mov [edi], edx ' mov edi, DWORD PTR [ebp+12] ' mov [edi], eax ' pop edi ' pop ecx ' pop edx ' mov esp, ebp ;'//MOV/POP is much faster ' pop ebp ;'//on 486 and Pentium than Leave ' ret 4 '#ASM_END End Sub |
User contributed notes:
| Author: CR () | Date: 10:01 31/01/2006 |
| How do you get the frequency of the CPU? | |