Dynamic vs static linking

[InfiniteLoop]

Ah yes, I made a mistake.

Would you trust an .exe from a random over the internet?

NT is the lowest level, the "native windows API". I assumed its faster and didn't even need to be tested.

Normal call 36 cycles.
Dynamic call 35 cycles.
NT syscall 252 cycles.

[zedd151]

Would you trust an .exe from a random over the internet?

From here, from a known member, absolutely. Also, the file can be inspected, if from an unknown source like a brand new member, or an external (meaning not from an attachment on the forum) link.

NT is the lowest level, the "native windows API".

Ok. I had never bothered with syscalls.

I assumed its faster and didn't even need to be tested.

Normal call 105 cycles.
Dynamic call 118 cycles.
NT syscall 720 cycles.

Well, now you know.  And so do we. 

[TimoVJL]

Pelles C project using that code

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normal: 3925
dynamic: 2676
syscall: 3647

normal: 2833
dynamic: 3341
syscall: 2899

[zedd151]

Pelles C project using that code

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normal: 3925
dynamic: 2676
syscall: 3647

normal: 2833
dynamic: 3341
syscall: 2899

first run

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normal: 82
dynamic: 46
syscall: 1976

another run

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normal: 47
dynamic: 46
syscall: 2085
Intel(R) Core(TM) i7-7700 CPU @ 3.60GHz   3.60 GHz - btw

[TimoVJL]

This Pelles c project test normal call NtQueryPerformanceCounter() too.
No differences ?

[zedd151]

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C:\Users\Administrator\Downloads\TestDynImpLib_WS2>TestDynImpLib.exe
231 ticks dynamic
231 ticks implib
9842 ticks native

237 ticks dynamic
365 ticks implib
5713 ticks native

231 ticks dynamic
231 ticks implib
5564 ticks native

229 ticks dynamic
230 ticks implib
6366 ticks native

392 ticks dynamic
251 ticks implib
6775 ticks native


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C:\Users\Administrator\Downloads\TestDynImpLib_WS2>TestDynImpLib64.exe
125 ticks dynamic
126 ticks implib
4854 ticks native

126 ticks dynamic
139 ticks implib
5131 ticks native

125 ticks dynamic
130 ticks implib
5190 ticks native

126 ticks dynamic
126 ticks implib
5156 ticks native

126 ticks dynamic
126 ticks implib
4873 ticks native


[TimoVJL]

So NtQueryPerformanceCounter() slow in Windows 10 / 11
My test was in Windows 7

[zedd151]

So NtQueryPerformanceCounter() slow in Windows 10 / 11

It would seem so.
Windows 10 here.

[jj2007]

Please note that the topic is dynamic vs static linking the same function. Timing two entirely different functions, i.e. ntdll NtQueryPerformanceCounter vs kernel32 QueryPerformanceCounter makes absolutely no sense in this context.

[TimoVJL]

Please note that the topic is dynamic vs static linking the same function. Timing two entirely different functions, i.e. ntdll NtQueryPerformanceCounter vs kernel32 QueryPerformanceCounter makes absolutely no sense in this context.

That function is kernel function, that do QueryPerformanceCounter() and QueryPerformanceFrequency() one go in same function.
Calling it from user level might slow it down.

[jj2007]

Calling it from user level might slow it down.

In fact, both call eventually QueryPerformanceCounter but the ntdll version passes by a Wow64Transition call:

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for (int n=0; n<5; n++) {
pQueryPerformanceCounter((LARGE_INTEGER*)&ll1);
_asm int 3; // jmp near [<&api-ms-win-core-profile-l1-1-0.QueryPerformanceCounter>]
for (i=0; i< 1000; i++)
pQueryPerformanceCounter((LARGE_INTEGER*)&ll2);
printf("%d ticks dynamic\n", ll2-ll1);

QueryPerformanceCounter((LARGE_INTEGER*)&ll1);
for (i=0; i< 1000; i++)
QueryPerformanceCounter((LARGE_INTEGER*)&ll2);
printf("%d ticks implib\n", ll2-ll1);

pNTQueryPerformanceCounter((LARGE_INTEGER*)&ll1, (LARGE_INTEGER*)&ll3);
_asm int 3;
// jmp near [Wow64Transition], followed by jmp far 0033:77787009
// jmp near [<&api-ms-win-core-profile-l1-1-0.QueryPerformanceCounter>]
for (i=0; i< 1000; i++)
pNTQueryPerformanceCounter((LARGE_INTEGER*)&ll2, (LARGE_INTEGER*)&ll3);
printf("%d ticks native\n", ll2-ll1);
printf("\n");
}

[TimoVJL]

Thanks for testing that mystery.

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pNTQueryPerformanceCounter((LARGE_INTEGER*)&ll1, NULL);didn't change speed at all in Windows 7