user: Please show me the C implementation that matches the assembly code listed below:

```asm
<moral_regla6>:
  endbr64
  push   %r14
  push   %r13
  push   %r12
  mov    %rdi,%r12
  push   %rbp
  mov    %edx,%ebp
  mov    $0x4,%edx
  push   %rbx
  mov    %rsi,%rbx
  xor    %esi,%esi
  call   <memset@plt>
  mov    0x8(%rbx),%rdi
  call   <strlen@plt>
  cmp    $0x1,%eax
  jle    L46
  test   %ebp,%ebp
  jne    L48
L10:
  mov    0x8(%rbx),%rax
  movsbl 0x1(%rax),%edi
  call   <toupper@plt>
  mov    %eax,%r13d
  mov    0x8(%rbx),%rax
  movsbl (%rax),%edi
  call   <toupper@plt>
  mov    %eax,%ebp
  mov    (%rbx),%rax
  movsbl (%rax),%edi
  call   <toupper@plt>
  mov    %r13d,%r9d
  mov    %ebp,%r8d
  mov    %r12,%rdi
  mov    %eax,%ecx
  lea    D18(%rip),%rdx
  mov    $0x4,%esi
  xor    %eax,%eax
  call   <snprintf@plt>
  pop    %rbx
  mov    %r12,%rax
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
  nopl   0x0(%rax)
L46:
  test   %ebp,%ebp
  jne    L17
L0:
  mov    0x8(%rbx),%rax
  movsbl (%rax),%edi
  call   <toupper@plt>
  mov    %eax,%ebp
  mov    (%rbx),%rax
  movsbl (%rax),%edi
  call   <toupper@plt>
  mov    %ebp,%r8d
  mov    %r12,%rdi
  mov    $0x4,%esi
  mov    %eax,%ecx
  lea    D21(%rip),%rdx
  xor    %eax,%eax
  call   <snprintf@plt>
  pop    %rbx
  mov    %r12,%rax
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
  nopl   0x0(%rax,%rax,1)
L48:
  mov    0x8(%rbx),%rax
  movsbl 0x1(%rax),%edi
  call   <toupper@plt>
  mov    %eax,%r13d
  mov    0x8(%rbx),%rax
  movsbl (%rax),%edi
  call   <toupper@plt>
  mov    0x8(%rbx),%r14
  mov    %eax,%ebp
  mov    (%rbx),%rax
  movsbl (%rax),%edi
  call   <toupper@plt>
  mov    (%rbx),%rsi
  mov    %r13d,%r9d
  mov    %ebp,%r8d
  mov    %eax,%edx
  mov    %r14,%rcx
  lea    D36(%rip),%rdi
  xor    %eax,%eax
  call   <printf@plt>
  jmp    L10
  xchg   %ax,%ax
L17:
  mov    0x8(%rbx),%rax
  movsbl (%rax),%edi
  call   <toupper@plt>
  mov    0x8(%rbx),%r13
  mov    %eax,%ebp
  mov    (%rbx),%rax
  movsbl (%rax),%edi
  call   <toupper@plt>
  mov    (%rbx),%rsi
  mov    %ebp,%r8d
  mov    %r13,%rcx
  mov    %eax,%edx
  lea    D6(%rip),%rdi
  xor    %eax,%eax
  call   <printf@plt>
  jmp    L0
```

tool_calls: name: unpack_data
arguments: data_tag: D18
data_type: string
name: unpack_data
arguments: data_tag: D21
data_type: string
name: unpack_data
arguments: data_tag: D36
data_type: string
name: unpack_data
arguments: data_tag: D6
data_type: string

tool: D18: %c%c%c

tool: D21: %c%cX

tool: D36: Aplicando regla 6:
	%-20s %c
	%-20s %c%c


tool: D6: Aplicando regla 6, y regla 8 (agregando una X al final para completar la clave):
	%-20s %c
	%-20s %c


assistant: ```c
char *moral_regla6(char *result, char *palabras[], const int verbose) {
  memset(result, 0, 4);
  if (strlen(palabras[1]) > 1) {
    if (verbose)
      printf("Aplicando regla 6:\n\t%-20s %c\n\t%-20s %c%c\n", palabras[0], toupper(*palabras[0]), palabras[1], toupper(*palabras[1]), toupper(*(palabras[1] + 1)));
    snprintf(result, 4, "%c%c%c", toupper(*palabras[0]), toupper(*palabras[1]), toupper(*(palabras[1] + 1)));
  } else {
    if (verbose)
      printf("Aplicando regla 6, y regla 8 (agregando una X al final para completar la clave):\n\t%-20s %c\n\t%-20s %c\n", palabras[0], toupper(*palabras[0]), palabras[1], toupper(*palabras[1]));
    snprintf(result, 4, "%c%cX", toupper(*palabras[0]), toupper(*palabras[1]));
  }
  return result;
}
```