[Nasm-users] Code Is Acting Funny

[James W. <jam...@ya...>]

Hello! I am trying to improve my knowledge of NASM and
IA32 assembler by translating the lessons from
Petzold's Programming Windows into NASM assembler.

The thing is that adding additional instructions is
causing the program to draw erratically. BUT! That can
be fixed by adding nonsensical code.

For example, the program runs OK until I add the
following to it

push dword WHITE_BRUSH
call [GetStockObject]
; ignore result in eax

This is at a point where eax does not need to be
preserved.

Then I add the following code
push dword eax
add esp,4

The program runs properly now

As I check this code can be inserted after add esp,4

xor eax,eax

And it makes no difference. Because eax should not
matter there.

I realize that many people on this list are not using
Windows, but I am just stymied. Is there an issue with
code alignment, linking, what?

I must be doing something REALLY STUPID but I just
can't think where to look. I suppose that there is an
error somewhere else in my code but how could push eax
add esp,4 correct them?

Does it make sense to suspect the linker?

Thanks

James


		
____________________________________________________
Start your day with Yahoo! - make it your home page 
http://www.yahoo.com/r/hs