Something strange...

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Necromancer13

Joined: 18 Oct 2007
Posts: 32
Location: Ukraine

Necromancer13 22 Oct 2007, 05:16

FASM converts

Code:

cmp word[var],'MZ'

Code:

cmp word ptr [var],5A4D

but not to

Code:

cmp word ptr [var],4D5A

But 'MZ' is 4D5A, not 5A4D!
is it a bug?

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22 Oct 2007, 05:16

LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 22 Oct 2007, 05:22

http://flatassembler.net/docs.php?article=faq (and perhaps somewhere in the documentation but by a quick search I wasn't able to find it)

Quote:

Why the instruction mov eax,'ABCD' is assembled into mov eax,44434241h? Shouldn't it be reversed?

Altough the most of other assemblers interpret quoted values treating the first character as the most significant, I've decided to use this different approach, just because it's more handy in the most situations. That's because for x86 architecture the least significant byte is the first byte in memory, so if you want to check whether there is 'ABCD' string at ebx address, you can just write cmp dword [ebx],'ABCD'.

22 Oct 2007, 05:22

Necromancer13

Joined: 18 Oct 2007
Posts: 32
Location: Ukraine

Necromancer13 22 Oct 2007, 05:29

ok.. thanks:)

22 Oct 2007, 05:29

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