Is popping into variable is possible?

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ght2142

Joined: 11 Oct 2012
Posts: 3

ght2142 23 Oct 2012, 13:36

I am new to assembly. I can't get this code running in fasm but i can use the same code using inline assembly. What am I doing wrong?

org 100h

a dd 1
b dd 2

push a
push b
pop a
pop b

Is using dd wrong cause i also used dw,db but all doesn't work. While in inline assembly i declared a and b using int datatype and used the code below and it worked.

_asm{
push a
push b
pop a
pop b}

And just as the title says, is popping into variable possible in fasm? I used registers for pushing and popping ang the code works fine.

(Thanks in advance to all).

23 Oct 2012, 13:36

Picnic

Joined: 05 May 2007
Posts: 1403
Location: Piraeus, Greece

Picnic 23 Oct 2012, 14:01

Hi ght2142,

Notice that in fasm

Code:

push a          ; pushes a variable address on stack.
push [a]        ; pushes a variable contents on stack.
pop [a]         ; pops value from stack in variable a.

Read more about in manual, section 2.1.1 Data movement instructions

23 Oct 2012, 14:01

ejamesr

Joined: 04 Feb 2011
Posts: 52
Location: Provo, Utah, USA

ejamesr 24 Oct 2012, 16:28

When you pop a register, the last item on the stack is popped. In your example above, after popping, a will have the original value of b, and b will have the original value of a. Is that what you wanted to do?

24 Oct 2012, 16:28

ght2142

Joined: 11 Oct 2012
Posts: 3

ght2142 27 Oct 2012, 12:02

Ok, my problem is all solved. Thanks to PICNIC. U the man!

27 Oct 2012, 12:02

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