C to Linux x86-64 Assembly (ASM) examples

2arg_func.c

#include <stdio.h>

int example(int a, int b) {
  return a + b + 3;
}

int main(void) {
  printf("%i\n", example(1, 2));
  return 0;
}

2arg_func.s

  .globl  example
  .type  example, @function
example:
  pushq  %rbp
  movq  %rsp, %rbp
  movl  %edi, -4(%rbp)
  movl  %esi, -8(%rbp)
  movl  -8(%rbp), %eax
  movl  -4(%rbp), %edx
  addl  %edx, %eax
  addl  $3, %eax
  popq  %rbp
  ret
.LFE0:
  .size  example, .-example
  .section  .rodata
.LC0:
  .string  "%i\n"

  .globl  main
  .type  main, @function
main:
  pushq  %rbp
  movq  %rsp, %rbp
  movl  $2, %esi
  movl  $1, %edi
  call  example
  movl  %eax, %edx
  movl  $.LC0, %eax
  movl  %edx, %esi
  movq  %rax, %rdi
  movl  $0, %eax
  call  printf
  movl  $0, %eax
  popq  %rbp
  ret

9arg_func.c

#include <stdio.h>

int example(int a, int b, int c, int d, int e, int f, int g, int h, int i) {
  return a + b + c + d + e + f + g + h + i + 3;
}

int main(void) {
  printf("%i\n", example(1, 2, 3, 4, 5, 6, 7, 8, 9));
  return 0;
}

9arg_func.s

  .globl  example
  .type  example, @function
example:
  pushq  %rbp
  movq  %rsp, %rbp
  movl  %edi, -4(%rbp)
  movl  %esi, -8(%rbp)
  movl  %edx, -12(%rbp)
  movl  %ecx, -16(%rbp)
  movl  %r8d, -20(%rbp)
  movl  %r9d, -24(%rbp)
  movl  -8(%rbp), %eax
  movl  -4(%rbp), %edx
  addl  %edx, %eax
  addl  -12(%rbp), %eax
  addl  -16(%rbp), %eax
  addl  -20(%rbp), %eax
  addl  -24(%rbp), %eax
  addl  16(%rbp), %eax
  addl  24(%rbp), %eax
  addl  32(%rbp), %eax
  addl  $3, %eax
  popq  %rbp
  ret
.LFE0:
  .size  example, .-example
  .section  .rodata
.LC0:
  .string  "%i\n"
  .globl  main
  .type  main, @function
main:
  pushq  %rbp
  movq  %rsp, %rbp
  subq  $32, %rsp
  movl  $9, 16(%rsp)
  movl  $8, 8(%rsp)
  movl  $7, (%rsp)
  movl  $6, %r9d
  movl  $5, %r8d
  movl  $4, %ecx
  movl  $3, %edx
  movl  $2, %esi
  movl  $1, %edi
  call  example
  movl  %eax, %edx
  movl  $.LC0, %eax
  movl  %edx, %esi
  movq  %rax, %rdi
  movl  $0, %eax
  call  printf
  movl  $0, %eax
  leave
  ret

for_loop.c

void _start(void) {
  for (int i=0; i<10; i++) {
  }
}

for_loop.s

  .global _start
_start:
  pushq  %rbp
  movq  %rsp, %rbp
  movl  $0, -4(%rbp)
  jmp  .L2
.L3:
  addl  $1, -4(%rbp)
.L2:
  cmpl  $9, -4(%rbp)
  jle  .L3
  popq  %rbp

if_else.c

int main(void) {
  int a=1, b=2;
  if (a < b)
    return 0;
  else
    return 1;
}

if_else.s

  .globl  main
main:
  pushq  %rbp
  movq  %rsp, %rbp
  movl  $1, -8(%rbp)
  movl  $2, -4(%rbp)
  movl  -8(%rbp), %eax
  cmpl  -4(%rbp), %eax
  jge  .L2
  movl  $0, %eax
  jmp  .L3
.L2:
  movl  $1, %eax
.L3:
  popq  %rbp
  ret

struct.c

int main(void) {
  struct {
    int a;
    char b;
    char c[3];
  } A = { a: 1, b: 'B', c: "Cat" };
  return 0;
}

struct.s

  .globl  main
main:
  pushq  %rbp
  movq  %rsp, %rbp

  movl  $1, -16(%rbp)
  movb  $66, -12(%rbp)
  movw  $24899, -11(%rbp)
  movb  $116, -9(%rbp)

  movl  $0, %eax
  popq  %rbp
  ret

while.c

void _start(void) {
  int i = 0;
  while (i<10) {
    i++;
  }
}

while.s

  .global _start
_start:
  pushq  %rbp
  movq  %rsp, %rbp
  movl  $0, -4(%rbp)
  jmp  .L2
.L3:
  addl  $1, -4(%rbp)
.L2:
  cmpl  $9, -4(%rbp)
  jle  .L3
  popq  %rbp