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

```asm
<qsort>:
  endbr64
  push   %r15
  mov    %rdi,%r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %esi,0x34(%rsp)
  mov    %edx,0x38(%rsp)
L90:
  mov    0x34(%rsp),%ebx
  mov    0x38(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  mov    %ebx,0x2c(%rsp)
  call   <part@plt>
  mov    %eax,0x34(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x30(%rsp)
  cmp    %ebx,%eax
  jg     L149
L252:
  mov    0x34(%rsp),%ecx
  cmp    %ecx,0x38(%rsp)
  jg     L90
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax,%rax,1)
L149:
  mov    0x2c(%rsp),%ebx
  mov    0x30(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  mov    %ebx,0x20(%rsp)
  call   <part@plt>
  mov    %eax,0x2c(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x28(%rsp)
  cmp    %eax,%ebx
  jl     L82
L84:
  mov    0x2c(%rsp),%ecx
  cmp    %ecx,0x30(%rsp)
  jg     L149
  jmp    L252
  nopl   0x0(%rax)
L82:
  mov    0x20(%rsp),%ebx
  mov    0x28(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  mov    %ebx,0x18(%rsp)
  call   <part@plt>
  mov    %eax,0x20(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x1c(%rsp)
  cmp    %eax,%ebx
  jl     L27
L118:
  mov    0x20(%rsp),%ecx
  cmp    %ecx,0x28(%rsp)
  jg     L82
  jmp    L84
  nopl   0x0(%rax)
L27:
  mov    0x18(%rsp),%ebx
  mov    0x1c(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  mov    %ebx,0x10(%rsp)
  call   <part@plt>
  mov    %eax,0x18(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x14(%rsp)
  cmp    %eax,%ebx
  jl     L31
L151:
  mov    0x18(%rsp),%ecx
  cmp    %ecx,0x1c(%rsp)
  jg     L27
  jmp    L118
  nopl   0x0(%rax)
L31:
  mov    0x10(%rsp),%ebx
  mov    0x14(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  mov    %ebx,0x8(%rsp)
  call   <part@plt>
  mov    %eax,0x10(%rsp)
  sub    $0x1,%eax
  mov    %eax,0xc(%rsp)
  cmp    %eax,%ebx
  jl     L86
L251:
  mov    0x10(%rsp),%ecx
  cmp    %ecx,0x14(%rsp)
  jg     L31
  jmp    L151
  nopl   0x0(%rax)
L86:
  mov    0x8(%rsp),%ebx
  mov    0xc(%rsp),%edx
  mov    %r15,%rdi
  mov    %ebx,%esi
  call   <part@plt>
  mov    %eax,0x8(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x4(%rsp)
  cmp    %eax,%ebx
  jl     L67
L187:
  mov    0x8(%rsp),%ecx
  cmp    %ecx,0xc(%rsp)
  jg     L86
  jmp    L251
  nopl   (%rax)
L67:
  mov    0x4(%rsp),%edx
  mov    %ebx,%esi
  mov    %r15,%rdi
  mov    %ebx,%r14d
  call   <part@plt>
  lea    -0x1(%rax),%r12d
  mov    %eax,%ebx
  cmp    %r12d,%r14d
  jl     L266
L70:
  cmp    %ebx,0x4(%rsp)
  jg     L67
  jmp    L187
  nopl   0x0(%rax)
L266:
  mov    %eax,0x24(%rsp)
L24:
  mov    %r14d,%esi
  mov    %r12d,%edx
  mov    %r15,%rdi
  mov    %r14d,%ebp
  call   <part@plt>
  lea    -0x1(%rax),%r13d
  mov    %eax,%r14d
  cmp    %r13d,%ebp
  jl     L167
L186:
  cmp    %r14d,%r12d
  jg     L24
  mov    0x24(%rsp),%ebx
  jmp    L70
  nopl   0x0(%rax)
L167:
  mov    %r13d,%ebx
  mov    %ebp,%eax
L142:
  mov    %ebx,%edx
  mov    %eax,%esi
  mov    %r15,%rdi
  mov    %eax,%r13d
  call   <part@plt>
  lea    -0x1(%rax),%edx
  cmp    %edx,%r13d
  jl     L45
L210:
  cmp    %eax,%ebx
  jg     L142
  jmp    L186
  nopw   0x0(%rax,%rax,1)
L45:
  mov    %r13d,%esi
  mov    %r15,%rdi
  mov    %eax,0x3c(%rsp)
  call   <qsort>
  mov    0x3c(%rsp),%eax
  jmp    L210
```

assistant: ```c
void qsort(int a[], int l, int r) {
  int m;
  m = part(a, l, r);
  if (l < m - 1)
    qsort(a, l, m - 1);
  if (m < r)
    qsort(a, m, r);
}
```