user: What would the C source look like for the assembly code provided here:

```asm
<countsort>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,-0x68(%rbp)
  mov    %esi,-0x6c(%rbp)
  mov    %edx,-0x70(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x18(%rbp)
  xor    %eax,%eax
  mov    %rsp,%rax
  mov    %rax,%r8
  mov    -0x6c(%rbp),%eax
  movslq %eax,%rdx
  sub    $0x1,%rdx
  mov    %rdx,-0x50(%rbp)
  movslq %eax,%rdx
  mov    %rdx,%r10
  mov    $0x0,%r11d
  movslq %eax,%rdx
  mov    %rdx,%rcx
  mov    $0x0,%ebx
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    $0x10,%eax
  sub    $0x1,%rax
  add    %rdx,%rax
  mov    $0x10,%ebx
  mov    $0x0,%edx
  div    %rbx
  imul   $0x10,%rax,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffff000,%rcx
  mov    %rsp,%rdx
  sub    %rcx,%rdx
L58:
  cmp    %rdx,%rsp
  je     L77
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L58
L77:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L119
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L119:
  mov    %rsp,%rax
  add    $0x3,%rax
  shr    $0x2,%rax
  shl    $0x2,%rax
  mov    %rax,-0x48(%rbp)
  movq   $0x0,-0x40(%rbp)
  movq   $0x0,-0x38(%rbp)
  movq   $0x0,-0x30(%rbp)
  movq   $0x0,-0x28(%rbp)
  movq   $0x0,-0x20(%rbp)
  movl   $0x0,-0x54(%rbp)
  jmp    L106
L54:
  mov    -0x54(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  cltd
  idivl  -0x70(%rbp)
  mov    %eax,%ecx
  movslq %ecx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %ecx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%edx
  mov    %edx,%eax
  shl    $0x2,%eax
  add    %edx,%eax
  add    %eax,%eax
  sub    %eax,%ecx
  mov    %ecx,%edx
  movslq %edx,%rax
  mov    -0x40(%rbp,%rax,4),%eax
  lea    0x1(%rax),%ecx
  movslq %edx,%rax
  mov    %ecx,-0x40(%rbp,%rax,4)
  addl   $0x1,-0x54(%rbp)
L106:
  mov    -0x54(%rbp),%eax
  cmp    -0x6c(%rbp),%eax
  jl     L54
  movl   $0x1,-0x54(%rbp)
  jmp    L111
L42:
  mov    -0x54(%rbp),%eax
  cltq
  mov    -0x40(%rbp,%rax,4),%edx
  mov    -0x54(%rbp),%eax
  sub    $0x1,%eax
  cltq
  mov    -0x40(%rbp,%rax,4),%eax
  add    %eax,%edx
  mov    -0x54(%rbp),%eax
  cltq
  mov    %edx,-0x40(%rbp,%rax,4)
  addl   $0x1,-0x54(%rbp)
L111:
  cmpl   $0x9,-0x54(%rbp)
  jle    L42
  mov    -0x6c(%rbp),%eax
  sub    $0x1,%eax
  mov    %eax,-0x54(%rbp)
  jmp    L14
L68:
  mov    -0x54(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  lea    (%rdx,%rax,1),%rsi
  mov    -0x54(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  cltd
  idivl  -0x70(%rbp)
  mov    %eax,%ecx
  movslq %ecx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %ecx,%edi
  sar    $0x1f,%edi
  sub    %edi,%eax
  mov    %eax,%edx
  mov    %edx,%eax
  shl    $0x2,%eax
  add    %edx,%eax
  add    %eax,%eax
  sub    %eax,%ecx
  mov    %ecx,%edx
  movslq %edx,%rax
  mov    -0x40(%rbp,%rax,4),%eax
  lea    -0x1(%rax),%edx
  mov    (%rsi),%ecx
  mov    -0x48(%rbp),%rax
  movslq %edx,%rdx
  mov    %ecx,(%rax,%rdx,4)
  mov    -0x54(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  cltd
  idivl  -0x70(%rbp)
  mov    %eax,%ecx
  movslq %ecx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %ecx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%edx
  mov    %edx,%eax
  shl    $0x2,%eax
  add    %edx,%eax
  add    %eax,%eax
  sub    %eax,%ecx
  mov    %ecx,%edx
  movslq %edx,%rax
  mov    -0x40(%rbp,%rax,4),%eax
  lea    -0x1(%rax),%ecx
  movslq %edx,%rax
  mov    %ecx,-0x40(%rbp,%rax,4)
  subl   $0x1,-0x54(%rbp)
L14:
  cmpl   $0x0,-0x54(%rbp)
  jns    L68
  movl   $0x0,-0x54(%rbp)
  jmp    L34
L47:
  mov    -0x54(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x48(%rbp),%rax
  mov    -0x54(%rbp),%edx
  movslq %edx,%rdx
  mov    (%rax,%rdx,4),%eax
  mov    %eax,(%rcx)
  addl   $0x1,-0x54(%rbp)
L34:
  mov    -0x54(%rbp),%eax
  cmp    -0x6c(%rbp),%eax
  jl     L47
  mov    %r8,%rsp
  nop
  mov    -0x18(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L7
  call   <__stack_chk_fail@plt>
L7:
  mov    -0x8(%rbp),%rbx
  leave
  ret
```

assistant: ```c
void countsort(int arr[], int n, int exp) {
  int output[n];
  int i, count[10] = {};
  for (i = 0; i < n; i++) {
    count[(arr[i] / exp) % 10]++;
  }
  for (i = 1; i < 10; i++) {
    count[i] = count[i] + count[i - 1];
  }
  for (i = n - 1; i >= 0; i--) {
    output[count[(arr[i] / exp) % 10] - 1] = arr[i];
    count[(arr[i] / exp) % 10]--;
  }
  for (i = 0; i < n; i++) {
    arr[i] = output[i];
  }
}
```