I don't quite understand this..

[iago]

Code Select Expand

.text:15006DD1                 xor     edx, edx
.text:15006DD3                 mov     eax, esi
.text:15006DD5                 div     ecx
.text:15006DD7                 push    edi
.text:15006DD8                 mov     edi, esi
.text:15006DDA                 test    edx, edx
.text:15006DDC                 jz      short loc_15006DE4
.text:15006DDE                 sub     ecx, edx


Can edx possibly be non-zero there?  If not, why would the compiler even allow this?  Note that there aren't any cross references to the middle of that

[Arta]

Yeah, div modifies edx. I think it stores the remainder? Something like that.

[Maddox]

div edx is equivalent to
temp = edx;
eax = eax / temp;
edx = eax % temp;

This piece of code is probably doing some aligning.

[Adron]

div edx is equivalent to
temp = edx;
eax = eax / temp;
edx = eax % temp;

This piece of code is probably doing some aligning.

div edx would be
__int64 temp = (edx<<32) + eax;
eax = temp / edx;
edx = temp % edx;

Makes more sense to use ecx for dividing, since edx is part of the number you're dividing by edx too.

[iago]

ooh, you're right, I didn't even notice that div!  Silly me!  Thanks