user: What would the C source look like for the assembly code provided here:

```asm
<basepairing>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x18(%rbp)
  mov    %esi,-0x1c(%rbp)
  mov    %edx,-0x20(%rbp)
  mov    %rcx,-0x28(%rbp)
  mov    -0x28(%rbp),%rax
  movl   $0x0,(%rax)
  movl   $0x0,-0x4(%rbp)
  jmp    L83
L44:
  mov    -0x20(%rbp),%eax
  cltq
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  sub    %rdx,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  cmp    $0x6e,%al
  jne    L181
  mov    -0x4(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  cmp    $0x6e,%al
  je     L181
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  lea    0x1(%rax),%edx
  mov    -0x28(%rbp),%rax
  mov    %edx,(%rax)
  jmp    L63
L181:
  mov    -0x4(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  sub    $0x61,%eax
  cmp    $0x18,%eax
  ja     L63
  mov    %eax,%eax
  lea    0x0(,%rax,4),%rdx
  lea    D17(%rip),%rax
  mov    (%rdx,%rax,1),%eax
  cltq
  lea    D17(%rip),%rdx
  add    %rdx,%rax
  notrack jmp *%rax
  mov    -0x20(%rbp),%eax
  cltq
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  sub    %rdx,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  cmp    $0x74,%al
  jne    L200
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  lea    0x1(%rax),%edx
  mov    -0x28(%rbp),%rax
  mov    %edx,(%rax)
  jmp    L200
  mov    -0x20(%rbp),%eax
  cltq
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  sub    %rdx,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  cmp    $0x67,%al
  jne    L85
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  lea    0x1(%rax),%edx
  mov    -0x28(%rbp),%rax
  mov    %edx,(%rax)
  jmp    L85
  mov    -0x20(%rbp),%eax
  cltq
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  sub    %rdx,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  cmp    $0x63,%al
  je     L217
  mov    -0x20(%rbp),%eax
  cltq
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  sub    %rdx,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  cmp    $0x74,%al
  jne    L29
L217:
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  lea    0x1(%rax),%edx
  mov    -0x28(%rbp),%rax
  mov    %edx,(%rax)
  jmp    L29
  mov    -0x20(%rbp),%eax
  cltq
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  sub    %rdx,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  cmp    $0x61,%al
  je     L65
  mov    -0x20(%rbp),%eax
  cltq
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  sub    %rdx,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  cmp    $0x67,%al
  jne    L8
L65:
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  lea    0x1(%rax),%edx
  mov    -0x28(%rbp),%rax
  mov    %edx,(%rax)
  jmp    L8
  mov    -0x20(%rbp),%eax
  cltq
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  sub    %rdx,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  cmp    $0x6e,%al
  je     L80
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  lea    0x1(%rax),%edx
  mov    -0x28(%rbp),%rax
  mov    %edx,(%rax)
  jmp    L80
L200:
  nop
  jmp    L63
L85:
  nop
  jmp    L63
L29:
  nop
  jmp    L63
L8:
  nop
  jmp    L63
L80:
  nop
L63:
  addl   $0x1,-0x4(%rbp)
L83:
  mov    -0x4(%rbp),%eax
  cmp    -0x1c(%rbp),%eax
  jl     L44
  nop
  nop
  pop    %rbp
  ret
```

assistant: ```c
void basepairing(char *ptr, int npair, int lpair, int *ncomp) {
  int n;
  *ncomp = 0;
  for (n = 0; n < npair; n++) {
    if ((*(ptr + lpair - n) == 'n') && (*(ptr + n) != 'n')) {
      (*ncomp)++;
    } else {
      switch (*(ptr + n)) {
      case 'a':
        if (*(ptr + lpair - n) == 't')
          (*ncomp)++;
        break;
      case 'c':
        if (*(ptr + lpair - n) == 'g')
          (*ncomp)++;
        break;
      case 'g':
      case 'r':
        if ((*(ptr + lpair - n) == 'c') || (*(ptr + lpair - n) == 't'))
          (*ncomp)++;
        break;
      case 't':
      case 'y':
        if ((*(ptr + lpair - n) == 'a') || (*(ptr + lpair - n) == 'g'))
          (*ncomp)++;
        break;
      case 'n':
        if (*(ptr + lpair - n) != 'n')
          (*ncomp)++;
        break;
      }
    }
  }
}
```