Anatomy of an Assembly Program

Here is a very simple c/c++ program and its assembly program compiled using flag -S.
There are no headers included.

int main(){
  return 0;
}

Following is the output generated.

This output shows an anatomy of an

; represents sections in the program like .bss section, .text section etc.
 .file "simple.cpp"
 .text
 .globl main
 .type main, @function
; entry to main function
main:
; push the current value of each should be pushed onto the stack to be restored at the end
 pushq %rbp
; move the contents of stack pointer to rbp register.
 movq %rsp, %rbp
; push the exit code 0 to the eax register.
 movl $0, %eax
; pop the contents of rbp register.
 popq %rbp
; return from the program.
 ret

Author: Saurabh Purnaye

VP - Low Latency Developer @jpmchase... Linux, C++, Python, Ruby. pursuing certificate in #QuantFinance and Passed CFA L1 View all posts by Saurabh Purnaye