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Razneb



Joined: 10 Feb 2005
Posts: 12
Razneb
Is it better to manually push the values then call a function.

Or is it better to use the invoke or stdcall macro and let it push and call the function automatically.

Which one is better to use. Resource, and speed-wise.

Razneb-
Post 10 Feb 2005, 03:48
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JohnFound



Joined: 16 Jun 2003
Posts: 3502
Location: Bulgaria
JohnFound
Actually it is approximately the same.
When using macroses "stdcall" and "invoke" we have more "compact" source code that is generally more readable. But sometimes using separate push instructions gives us more flexibility and better code.
For example, let say we save some register in the stack in order to preserve it for future call of API function:
Code:
invoke  GetDlgItem, [.hwnd], 100
push  eax   ; preserve eax for the second call of API

invoke SomeAPI, eax

pop eax
invoke OtherAPI, eax
    


The last two rows will generate following pretty bad code:
Code:
pop   eax
push  eax
call  [OtherAPI]
    


In similar cases (especially when there are more arguments to the functions) I am using:
Code:
invoke  OtherFunction, arg1, arg2  ;, agument is in the stack    


Note that good comments are simply mandatory in such using. The main requirement for optimal using of "invoke" type macroses is good understanding what actually happens behind the macro...

Regards
Post 10 Feb 2005, 04:17
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Razneb



Joined: 10 Feb 2005
Posts: 12
Razneb
So, lets say I am using 'CreateFont'. It would be a complete waste of line space if I manually pushed the 14 arguments?

Thanks for your reply.

Razneb-
Post 10 Feb 2005, 04:27
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f0dder



Joined: 19 Feb 2004
Posts: 3170
Location: Denmark
f0dder
yes, a waste of line space since there's no runtime advantage. Of course one could argue that if you manually push arguments you can add a comment on what each argument is, but... that's overkill, IMHO.
Post 10 Feb 2005, 12:44
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid
i prefer manual pushing if arguments need comments. And no one is such fool to remember meaning of 14 arguments, so it improves readability of code. Of course not with well known APIs.
Post 10 Feb 2005, 13:24
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r22



Joined: 27 Dec 2004
Posts: 805
r22
I use manual pushing and call instead of invoke, mostly because I have a bad habit of using hex instead of constant names so i have to shorthand comment them.
Post 11 Feb 2005, 06:06
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