Assembly Language for Beginners

1.8. PRINTF() WITH SEVERAL ARGUMENTS
In certain cases where several functions return right after one another, the compiler could merge multiple
“ADD ESP, X” instructions into one, after the last call:

push a1

push a2

call ...

...

push a1

call ...

...

push a1

push a2

push a3

call ...

add esp, 24

Here is a real-world example:

Listing 1.43: x86

.text:100113E7 push 3

.text:100113E9 call sub_100018B0 ; takes one argument (3)

.text:100113EE call sub_100019D0 ; takes no arguments at all

.text:100113F3 call sub_10006A90 ; takes no arguments at all

.text:100113F8 push 1

.text:100113FA call sub_100018B0 ; takes one argument (1)

.text:100113FF add esp, 8 ; drops two arguments from stack at once