user: What is the c source code of the assembly code below?

```asm
<quicksort>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %edx,0x24(%rsp)
  cmp    %edx,%esi
  jge    L16
  mov    %rdi,%r15
  mov    %esi,%r13d
L17:
  mov    0x24(%rsp),%edx
  mov    %r13d,%esi
  mov    %r15,%rdi
  call   <partition@plt>
  mov    %eax,0x28(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x18(%rsp)
  cmp    %r13d,%eax
  jle    L82
  mov    %r13d,%r14d
  mov    %r15,%r13
L103:
  mov    0x18(%rsp),%edx
  mov    %r14d,%esi
  mov    %r13,%rdi
  call   <partition@plt>
  mov    %eax,0x2c(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x1c(%rsp)
  cmp    %r14d,%eax
  jle    L162
  mov    %r14d,%eax
  mov    %r13,%r14
  mov    %eax,%r13d
L39:
  mov    0x1c(%rsp),%edx
  mov    %r13d,%esi
  mov    %r14,%rdi
  call   <partition@plt>
  mov    %eax,0x30(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x20(%rsp)
  cmp    %r13d,%eax
  jle    L91
L65:
  mov    0x20(%rsp),%edx
  mov    %r13d,%esi
  mov    %r14,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%r12d
  mov    %eax,0x34(%rsp)
  cmp    %r13d,%r12d
  jle    L146
L89:
  mov    %r12d,%edx
  mov    %r13d,%esi
  mov    %r14,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%ebx
  mov    %eax,%ebp
  cmp    %r13d,%ebx
  jle    L38
  mov    %r12d,0x8(%rsp)
  mov    %r13d,%r15d
  mov    %ebx,%ebp
  mov    %r14,%r13
  mov    %eax,%r14d
L70:
  mov    %ebp,%edx
  mov    %r15d,%esi
  mov    %r13,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%ebx
  mov    %eax,0x10(%rsp)
  cmp    %r15d,%ebx
  jle    L117
  mov    %ebp,0xc(%rsp)
  mov    %ebx,%ebp
  mov    %r13,%rbx
L157:
  mov    %ebp,%edx
  mov    %r15d,%esi
  mov    %rbx,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%r13d
  mov    %eax,0x38(%rsp)
  cmp    %r15d,%r13d
  jle    L127
  mov    %ebp,0x14(%rsp)
  mov    %rbx,%rbp
  mov    %r13d,%ebx
L90:
  mov    %ebx,%edx
  mov    %r15d,%esi
  mov    %rbp,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%r13d
  mov    %eax,%r12d
  cmp    %r15d,%r13d
  jle    L112
  mov    %ebx,%r12d
  mov    %eax,%ecx
  mov    %r13d,%ebx
L54:
  mov    %r15d,%esi
  mov    %ebx,%edx
  mov    %rbp,%rdi
  mov    %ecx,0x3c(%rsp)
  call   <partition@plt>
  mov    %r15d,%esi
  mov    %rbp,%rdi
  mov    %eax,%r13d
  lea    -0x1(%rax),%edx
  call   <quicksort>
  lea    0x1(%r13),%r15d
  mov    0x3c(%rsp),%ecx
  cmp    %r15d,%ebx
  jg     L54
  mov    %r12d,%ebx
  mov    %ecx,%r12d
L112:
  lea    0x1(%r12),%r15d
  cmp    %r15d,%ebx
  jg     L90
  mov    %rbp,%rbx
  mov    0x14(%rsp),%ebp
L127:
  mov    0x38(%rsp),%r15d
  add    $0x1,%r15d
  cmp    %r15d,%ebp
  jg     L157
  mov    0xc(%rsp),%ebp
  mov    %rbx,%r13
L117:
  mov    0x10(%rsp),%r15d
  add    $0x1,%r15d
  cmp    %r15d,%ebp
  jg     L70
  mov    0x8(%rsp),%r12d
  mov    %r14d,%ebp
  mov    %r13,%r14
L38:
  lea    0x1(%rbp),%r13d
  cmp    %r13d,%r12d
  jg     L89
L146:
  mov    0x34(%rsp),%r13d
  add    $0x1,%r13d
  cmp    %r13d,0x20(%rsp)
  jg     L65
L91:
  mov    0x30(%rsp),%r13d
  add    $0x1,%r13d
  cmp    %r13d,0x1c(%rsp)
  jg     L39
  mov    %r14,%r13
L162:
  mov    0x2c(%rsp),%r14d
  add    $0x1,%r14d
  cmp    %r14d,0x18(%rsp)
  jg     L103
  mov    %r13,%r15
L82:
  mov    0x28(%rsp),%r13d
  add    $0x1,%r13d
  cmp    0x24(%rsp),%r13d
  jl     L17
L16:
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void quicksort(int ar[][2], int l, int r) {
  int m = 0;
  if (l >= r) {
    return;
  }
  m = partition(ar, l, r);
  quicksort(ar, l, m - 1);
  quicksort(ar, m + 1, r);
}
```