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

```asm
<__merge>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %rdi,-0x48(%rbp)
  mov    %esi,-0x4c(%rbp)
  mov    %edx,-0x50(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x18(%rbp)
  xor    %eax,%eax
  mov    %rsp,%rax
  mov    %rax,%rsi
  mov    -0x4c(%rbp),%edx
  mov    -0x50(%rbp),%eax
  add    %edx,%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  mov    %eax,-0x2c(%rbp)
  mov    -0x4c(%rbp),%eax
  mov    %eax,-0x38(%rbp)
  mov    -0x2c(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x34(%rbp)
  movl   $0x0,-0x30(%rbp)
  mov    -0x50(%rbp),%eax
  sub    -0x4c(%rbp),%eax
  add    $0x1,%eax
  movslq %eax,%rdx
  sub    $0x1,%rdx
  mov    %rdx,-0x28(%rbp)
  movslq %eax,%rdx
  mov    %rdx,%r8
  mov    $0x0,%r9d
  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
L57:
  cmp    %rdx,%rsp
  je     L49
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L57
L49:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L58
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L58:
  mov    %rsp,%rax
  add    $0x3,%rax
  shr    $0x2,%rax
  shl    $0x2,%rax
  mov    %rax,-0x20(%rbp)
  jmp    L21
L6:
  mov    -0x38(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%edx
  mov    -0x34(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rcx
  mov    -0x48(%rbp),%rax
  add    %rcx,%rax
  mov    (%rax),%eax
  cmp    %eax,%edx
  jg     L129
  mov    -0x38(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x38(%rbp)
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  jmp    L93
L129:
  mov    -0x34(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x34(%rbp)
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
L93:
  mov    -0x30(%rbp),%edx
  lea    0x1(%rdx),%ecx
  mov    %ecx,-0x30(%rbp)
  mov    -0x20(%rbp),%rcx
  movslq %edx,%rdx
  mov    %eax,(%rcx,%rdx,4)
L21:
  mov    -0x38(%rbp),%eax
  cmp    -0x2c(%rbp),%eax
  jg     L95
  mov    -0x34(%rbp),%eax
  cmp    -0x50(%rbp),%eax
  jle    L6
  jmp    L95
L10:
  mov    -0x38(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x38(%rbp)
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x48(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x30(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x30(%rbp)
  mov    (%rcx),%ecx
  mov    -0x20(%rbp),%rdx
  cltq
  mov    %ecx,(%rdx,%rax,4)
L95:
  mov    -0x38(%rbp),%eax
  cmp    -0x2c(%rbp),%eax
  jle    L10
  jmp    L1
L8:
  mov    -0x34(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x34(%rbp)
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x48(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x30(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x30(%rbp)
  mov    (%rcx),%ecx
  mov    -0x20(%rbp),%rdx
  cltq
  mov    %ecx,(%rdx,%rax,4)
L1:
  mov    -0x34(%rbp),%eax
  cmp    -0x50(%rbp),%eax
  jle    L8
  mov    -0x4c(%rbp),%eax
  mov    %eax,-0x38(%rbp)
  movl   $0x0,-0x34(%rbp)
  jmp    L121
L134:
  mov    -0x34(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x34(%rbp)
  mov    -0x38(%rbp),%edx
  lea    0x1(%rdx),%ecx
  mov    %ecx,-0x38(%rbp)
  movslq %edx,%rdx
  lea    0x0(,%rdx,4),%rcx
  mov    -0x48(%rbp),%rdx
  add    %rdx,%rcx
  mov    -0x20(%rbp),%rdx
  cltq
  mov    (%rdx,%rax,4),%eax
  mov    %eax,(%rcx)
L121:
  mov    -0x34(%rbp),%eax
  cmp    -0x30(%rbp),%eax
  jl     L134
  mov    %rsi,%rsp
  nop
  mov    -0x18(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L72
  call   <__stack_chk_fail@plt>
L72:
  mov    -0x8(%rbp),%rbx
  leave
  ret
```

assistant: ```c
void __merge(int *a, int l, int r) {
  int m = (l + r) / 2;
  int i = l;
  int j = m + 1;
  int k = 0;
  int t[r - l + 1];
  while (i <= m && j <= r) {
    t[k++] = (a[i] <= a[j]) ? a[i++] : a[j++];
  }
  while (i <= m) {
    t[k++] = a[i++];
  }
  while (j <= r) {
    t[k++] = a[j++];
  }
  i = l;
  j = 0;
  while (j < k) {
    a[i++] = t[j++];
  }
}
```