A Disassembly Project with Function and Stack

push %rbp              # establishing stack frame
mov %rsp,%rbp
sub $0x20,%rsp         # creating stack frame for local variables
                       #    and function parameters
mov %edi,-0x14(%rbp)   # saving the first main parameter
mov %rsi,-0x20(%rbp)   # saving the second main parameter
mov $0x1,%esi          # setting the second parameter for
                       # arithmetic function
mov $0x1,%edi          # setting the first parameter for arithmetic
                       # function
callq 0x55555555514d <_Z10arithmeticii>
mov %eax,-0x4(%rbp)    # setting the result local variable
mov $0x0,%eax          # main should return 0
leaveq                 # restoring the previous stack pointer
                       # and stack frame, equivalent to
                       # mov %rbp, %rsp
                       # pop %rbp
retq                   # return from main

push %rbp              # establishing stack frame
mov %rsp,%rbp
mov %edi,-0x4(%rbp)    # saving the first arithmetic parameter (a)
mov %esi,-0x8(%rbp)    # saving the second arithmetic parameter (b)
mov -0x4(%rbp),%eax    # (a) -> eax
add %eax,-0x8(%rbp)    # eax + (b) -> (b)
addl $0x1,-0x4(%rbp)   # 1 + (a) -> (a)
mov -0x8(%rbp),%eax    # (b) -> eax
imul -0x4(%rbp),%eax   # (a) * eax -> eax
mov %eax,-0x8(%rbp)    # eax -> (b)
mov -0x8(%rbp),%eax    # (b) -> eax
pop %rbp               # restoring the previous stack frame
                       # no need to restore stack pointer as
                       # it didn’t change
retq                   # result value is in eax