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bogdanontanu



Joined: 07 Jan 2004
Posts: 403
Location: Sol. Earth. Europe. Romania. Bucuresti
bogdanontanu
Without macros you can use structures to make-up a stack frame layout and use this pretty much like a form of primitive locals or arguments based on EBP or ESP.

This is the way that modern ASM evolved in time and you can retrace the baby steps if your assembler does not have PROCs, LOCALS,ARGS and stack frames already implemented.
Post 06 Apr 2009, 11:14
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LocoDelAssembly
Your code has a bug


Joined: 06 May 2005
Posts: 4633
Location: Argentina
LocoDelAssembly
vid wrote:

Your code doesn't exactly reflect way used in funcs with omitted stack frames. You never "push" in such procs. You just reserve enough place on stack for arguments of every function you call, and then you MOVe arguments to stack. So the value of ESP doesn't change over all the procedure.

mmmh, right, but since those are stdcall functions I can't pre-reserve once and use many, I would have to reserve space every time I call a stdcall function. The second call on the code would be hard to avoid AGI stall (if really exists), unless I waste a second non-volatile register to store that address pre-calculated. Anyway, even if there is no stalls at all with this method I think that still it would be probably slower just because of having that extra "sub esp, args*4" instruction every time I call something.
Post 06 Apr 2009, 12:55
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid
oh yeah, right.
Post 06 Apr 2009, 13:28
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Borsuc



Joined: 29 Dec 2005
Posts: 2466
Location: Bucharest, Romania
Borsuc
vid wrote:
Your code doesn't exactly reflect way used in funcs with omitted stack frames. You never "push" in such procs. You just reserve enough place on stack for arguments of every function you call, and then you MOVe arguments to stack. So the value of ESP doesn't change over all the procedure.
...making the code even bigger.
Post 04 Dec 2009, 16:10
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid
Quote:
...making the code even bigger.

depends... remember that stdcall is choice of the day, and "add esp, xy" takes space too. Also, size of code doesn't matter to real world problems at all these days.
Post 04 Dec 2009, 16:46
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Borsuc



Joined: 29 Dec 2005
Posts: 2466
Location: Bucharest, Romania
Borsuc
pushing the parameters (actually setting them) with "mov" is much bigger than pushing. Not to mention if you push small values (sign-extended) where mov needs all bytes.

Code:
push 0    
vs
Code:
mov qword [rsp+offset], 0    
Post 04 Dec 2009, 22:20
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