user: 下面的汇编指令对应的C源代码是什么:

```asm
<quick_select_uint8>:
  endbr64
  push   %r14
  mov    %rdi,%r11
  push   %r13
  push   %r12
  push   %rbp
  lea    -0x1(%rsi),%ebp
  mov    %ebp,%r13d
  push   %rbx
  shr    $0x1f,%r13d
  add    %ebp,%r13d
  sar    %r13d
  test   %ebp,%ebp
  jle    L43
  cmp    $0x1,%ebp
  je     L48
  xor    %r12d,%r12d
  mov    $0x1,%eax
  nopl   0x0(%rax,%rax,1)
L136:
  lea    (%r12,%rbp,1),%ecx
  mov    %ecx,%edx
  shr    $0x1f,%edx
  add    %ecx,%edx
  movslq %ebp,%rcx
  sar    %edx
  add    %r11,%rcx
  movslq %edx,%rdx
  movzbl (%rcx),%edi
  add    %r11,%rdx
  movzbl (%rdx),%esi
  cmp    %dil,%sil
  jbe    L21
  mov    %dil,(%rdx)
  mov    %esi,%edi
  mov    %sil,(%rcx)
L21:
  movslq %r12d,%r8
  lea    (%r11,%r8,1),%rbx
  movzbl (%rbx),%esi
  cmp    %dil,%sil
  jbe    L99
  mov    %dil,(%rbx)
  mov    %sil,(%rcx)
  movzbl (%rbx),%esi
L99:
  movzbl (%rdx),%ecx
  cmp    %sil,%cl
  jbe    L147
  mov    %sil,(%rdx)
  mov    %cl,(%rbx)
  movzbl (%rdx),%ecx
L147:
  lea    0x1(%r11,%r8,1),%rsi
  add    $0x1,%eax
  movzbl (%rsi),%edi
  movslq %eax,%r8
  mov    %dil,(%rdx)
  mov    %ebp,%edx
  mov    %cl,(%rsi)
  movzbl (%rbx),%esi
  nopl   0x0(%rax)
L34:
  movzbl (%r11,%r8,1),%r10d
  mov    %r8d,%r14d
  cmp    %sil,%r10b
  jb     L104
  movslq %edx,%rax
  lea    -0x1(%r11,%rax,1),%rax
  nopl   (%rax)
L108:
  mov    %rax,%rdi
  movzbl (%rax),%ecx
  mov    %edx,%r9d
  sub    $0x1,%rax
  sub    $0x1,%edx
  cmp    %sil,%cl
  ja     L108
  cmp    %r8d,%edx
  jl     L0
  mov    %cl,(%r11,%r8,1)
  mov    %r10b,(%rdi)
  movzbl (%rbx),%esi
L104:
  add    $0x1,%r8
  jmp    L34
  nopw   0x0(%rax,%rax,1)
L0:
  mov    %cl,(%rbx)
  mov    %sil,(%rdi)
  cmp    %edx,%r13d
  jl     L93
  mov    %r14d,%r12d
  je     L93
L98:
  cmp    %r12d,%ebp
  jle    L43
  lea    0x1(%r12),%eax
  cmp    %ebp,%eax
  jne    L136
  movslq %r12d,%rdx
  movslq %ebp,%rax
  add    %r11,%rdx
L102:
  add    %r11,%rax
  movzbl (%rdx),%ecx
  movzbl (%rax),%esi
  cmp    %sil,%cl
  jbe    L43
  mov    %sil,(%rdx)
  mov    %cl,(%rax)
L43:
  movslq %r13d,%r13
  pop    %rbx
  pop    %rbp
  movzbl (%r11,%r13,1),%eax
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L93:
  lea    -0x2(%r9),%ebp
  jmp    L98
L48:
  mov    %rdi,%rdx
  mov    $0x1,%eax
  jmp    L102
```

assistant: ```c
unsigned char quick_select_uint8(unsigned char arr[], int n) {
  int low, high;
  int median;
  int middle, ll, hh;
  low = 0;
  high = n - 1;
  median = (low + high) / 2;
  for (;;) {
    if (high <= low)
      return arr[median];
    if (high == low + 1) {
      if (arr[low] > arr[high]) {
        unsigned char temp = (arr[low]);
        (arr[low]) = (arr[high]);
        (arr[high]) = temp;
      };
      return arr[median];
    }
    middle = (low + high) / 2;
    if (arr[middle] > arr[high]) {
      unsigned char temp = (arr[middle]);
      (arr[middle]) = (arr[high]);
      (arr[high]) = temp;
    };
    if (arr[low] > arr[high]) {
      unsigned char temp = (arr[low]);
      (arr[low]) = (arr[high]);
      (arr[high]) = temp;
    };
    if (arr[middle] > arr[low]) {
      unsigned char temp = (arr[middle]);
      (arr[middle]) = (arr[low]);
      (arr[low]) = temp;
    };
    {
      unsigned char temp = (arr[middle]);
      (arr[middle]) = (arr[low + 1]);
      (arr[low + 1]) = temp;
    };
    ll = low + 1;
    hh = high;
    for (;;) {
      do
        ll++;
      while (arr[low] > arr[ll]);
      do
        hh--;
      while (arr[hh] > arr[low]);
      if (hh < ll)
        break;
      {
        unsigned char temp = (arr[ll]);
        (arr[ll]) = (arr[hh]);
        (arr[hh]) = temp;
      };
    }
    {
      unsigned char temp = (arr[low]);
      (arr[low]) = (arr[hh]);
      (arr[hh]) = temp;
    };
    if (hh <= median)
      low = ll;
    if (hh >= median)
      high = hh - 1;
  }
}
```