Question

I saw two diffrent way to pass integer in assmbler: the one by [eax], the second by eax.
I’ll give an example:

section .rodata
print_int_str: "%d"
%macro     print_int  1
     push %1
     push print_int_str
     call printf
     add esp, 8
%endmacro

as I understood, we can use print_int eax, and also print_int [eax].

What is the difrrence between them?

Answer 1

print_int eax

will print you the value of eax

print_int [eax]

will use the value of eax as an address and will print the value that is stored at this address

so you can either put the integer into eax and use (any other reg will work too)

print_int eax

or if you have a variable you can do

print_int [var]; or
print_int [reg]; with regs value = address of var