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What does this assembly code do

Posted on 2014-04-07
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Trying to study some assembly code. What does the following line of assembly do?

sub_4012C6 proc near

var_401 = dword ptr -401h
var_1 = dword ptr -1
arg_0 = dword ptr 8

push ebp
mov ebp, esp

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Thank you.
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Question by:centem
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Dave Baldwin earned 2000 total points
ID: 39985342
It's been a while since I've done assembly code.  That looks like "procedure entry" code.  The procedure, 'sub_4012C6', is declared followed by 3 variables.  Then 'ebp' is saved on the stack and the stack pointer is copied to 'ebp'.  After that will come some code that gets and processes the variable data relative to the offset from the current value of 'ebp'.

It is normal to push the data onto the stack before calling a procedure.  This code gives the info to access the data on the stack.
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by:centem
ID: 39988724
What is the -401h, -1, and 8 in the assignment statements?
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by:Dave Baldwin
ID: 39989184
Probably the offsets from the stack point or 'ebp' where the data is located.
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