user: Demonstrate the C code that generates the assembly output below:

```asm
<quicksort>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x78,%rsp
  mov    %rdx,0x38(%rsp)
  cmp    $0xffffffffffffffff,%rdx
  je     L262
  cmp    %rsi,%rdx
  jbe    L262
  mov    %rdi,%r15
  mov    %rsi,%r13
L167:
  mov    0x38(%rsp),%rdx
  mov    %r13,%rsi
  mov    %r15,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%rcx
  mov    %rax,0x40(%rsp)
  mov    %rcx,0x20(%rsp)
  test   %rax,%rax
  je     L190
  cmp    %r13,%rcx
  jbe    L190
  mov    %r13,%r14
  mov    %r15,%r13
L238:
  mov    0x20(%rsp),%rdx
  mov    %r14,%rsi
  mov    %r13,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%rcx
  mov    %rax,0x48(%rsp)
  mov    %rcx,0x28(%rsp)
  test   %rax,%rax
  je     L134
  cmp    %r14,%rcx
  jbe    L134
  mov    %r14,%rax
  mov    %r13,%r14
  mov    %rax,%r13
L224:
  mov    0x28(%rsp),%rdx
  mov    %r13,%rsi
  mov    %r14,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%rcx
  mov    %rax,0x50(%rsp)
  mov    %rcx,0x30(%rsp)
  test   %rax,%rax
  je     L82
  cmp    %r13,%rcx
  jbe    L82
L129:
  mov    0x30(%rsp),%rdx
  mov    %r13,%rsi
  mov    %r14,%rdi
  call   <partition@plt>
  mov    %rax,0x58(%rsp)
  lea    -0x1(%rax),%r12
  test   %rax,%rax
  je     L7
  cmp    %r13,%r12
  jbe    L7
L229:
  mov    %r12,%rdx
  mov    %r13,%rsi
  mov    %r14,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%rbx
  mov    %rax,%rbp
  cmp    %r13,%rbx
  jbe    L250
  cmp    $0xffffffffffffffff,%rbx
  je     L250
  mov    %r12,(%rsp)
  mov    %r13,%r15
  mov    %rbx,%rbp
  mov    %r14,%r13
  mov    %rax,%r14
L33:
  mov    %rbp,%rdx
  mov    %r15,%rsi
  mov    %r13,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%rbx
  mov    %rax,0x10(%rsp)
  cmp    %r15,%rbx
  jbe    L247
  cmp    $0xffffffffffffffff,%rbx
  je     L247
  mov    %rbp,0x8(%rsp)
  mov    %rbx,%rbp
  mov    %r13,%rbx
L254:
  mov    %rbp,%rdx
  mov    %r15,%rsi
  mov    %rbx,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%r13
  mov    %rax,0x60(%rsp)
  cmp    %r15,%r13
  jbe    L253
  cmp    $0xffffffffffffffff,%r13
  je     L253
  mov    %rbp,0x18(%rsp)
  mov    %rbx,%rbp
  mov    %r13,%rbx
L14:
  mov    %rbx,%rdx
  mov    %r15,%rsi
  mov    %rbp,%rdi
  call   <partition@plt>
  lea    -0x1(%rax),%r13
  mov    %rax,%r12
  cmp    %r15,%r13
  jbe    L95
  cmp    $0xffffffffffffffff,%r13
  je     L95
  mov    %rbx,%r12
  mov    %rax,%rcx
  mov    %r13,%rbx
L89:
  mov    %r15,%rsi
  mov    %rbx,%rdx
  mov    %rbp,%rdi
  mov    %rcx,0x68(%rsp)
  call   <partition@plt>
  mov    %r15,%rsi
  mov    %rbp,%rdi
  mov    %rax,%r13
  lea    -0x1(%rax),%rdx
  call   <quicksort>
  lea    0x1(%r13),%r15
  mov    0x68(%rsp),%rcx
  cmp    %r15,%rbx
  ja     L89
  mov    %r12,%rbx
  mov    %rcx,%r12
L95:
  lea    0x1(%r12),%r15
  cmp    %r15,%rbx
  ja     L14
  mov    %rbp,%rbx
  mov    0x18(%rsp),%rbp
L253:
  mov    0x60(%rsp),%r15
  add    $0x1,%r15
  cmp    %r15,%rbp
  ja     L254
  mov    0x8(%rsp),%rbp
  mov    %rbx,%r13
L247:
  mov    0x10(%rsp),%r15
  add    $0x1,%r15
  cmp    %r15,%rbp
  ja     L33
  mov    (%rsp),%r12
  mov    %r14,%rbp
  mov    %r13,%r14
L250:
  lea    0x1(%rbp),%r13
  cmp    %r13,%r12
  ja     L229
L7:
  mov    0x58(%rsp),%r13
  add    $0x1,%r13
  cmp    %r13,0x30(%rsp)
  ja     L129
L82:
  mov    0x50(%rsp),%r13
  add    $0x1,%r13
  cmp    %r13,0x28(%rsp)
  ja     L224
  mov    %r14,%r13
L134:
  mov    0x48(%rsp),%r14
  add    $0x1,%r14
  cmp    %r14,0x20(%rsp)
  ja     L238
  mov    %r13,%r15
L190:
  mov    0x40(%rsp),%r13
  add    $0x1,%r13
  cmp    0x38(%rsp),%r13
  jb     L167
L262:
  add    $0x78,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void quicksort(int a[], size_t p, size_t r) {
  if (p < r && ~r) {
    size_t q = partition(a, p, r);
    quicksort(a, p, q - 1);
    quicksort(a, q + 1, r);
  }
}
```