user: Translate the below assembly code into C programming language:

```asm
<coin_encode_ascii85>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x18(%rbp)
  mov    %rsi,-0x20(%rbp)
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x18,%eax
  mov    %eax,%edx
  mov    -0x18(%rbp),%rax
  add    $0x1,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x10,%eax
  or     %eax,%edx
  mov    -0x18(%rbp),%rax
  add    $0x2,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x8,%eax
  or     %eax,%edx
  mov    -0x18(%rbp),%rax
  add    $0x3,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  or     %edx,%eax
  mov    %eax,-0x4(%rbp)
  cmpl   $0x0,-0x4(%rbp)
  jne    L18
  mov    -0x20(%rbp),%rax
  movb   $0x7a,(%rax)
  mov    $0x1,%eax
  jmp    L6
L18:
  mov    -0x4(%rbp),%edx
  mov    %edx,%ecx
  mov    $0xc0c0c0c1,%eax
  imul   %rcx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  imul   $0x55,%eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,%edx
  mov    -0x20(%rbp),%rax
  add    $0x4,%rax
  add    $0x21,%edx
  mov    %dl,(%rax)
  mov    -0x4(%rbp),%eax
  mov    %eax,%edx
  mov    $0xc0c0c0c1,%eax
  imul   %rdx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  mov    %eax,-0x4(%rbp)
  mov    -0x4(%rbp),%edx
  mov    %edx,%ecx
  mov    $0xc0c0c0c1,%eax
  imul   %rcx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  imul   $0x55,%eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,%edx
  mov    -0x20(%rbp),%rax
  add    $0x3,%rax
  add    $0x21,%edx
  mov    %dl,(%rax)
  mov    -0x4(%rbp),%eax
  mov    %eax,%edx
  mov    $0xc0c0c0c1,%eax
  imul   %rdx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  mov    %eax,-0x4(%rbp)
  mov    -0x4(%rbp),%edx
  mov    %edx,%ecx
  mov    $0xc0c0c0c1,%eax
  imul   %rcx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  imul   $0x55,%eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,%edx
  mov    -0x20(%rbp),%rax
  add    $0x2,%rax
  add    $0x21,%edx
  mov    %dl,(%rax)
  mov    -0x4(%rbp),%eax
  mov    %eax,%edx
  mov    $0xc0c0c0c1,%eax
  imul   %rdx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  mov    %eax,-0x4(%rbp)
  mov    -0x4(%rbp),%edx
  mov    %edx,%ecx
  mov    $0xc0c0c0c1,%eax
  imul   %rcx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  imul   $0x55,%eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,%edx
  mov    -0x20(%rbp),%rax
  add    $0x1,%rax
  add    $0x21,%edx
  mov    %dl,(%rax)
  mov    -0x4(%rbp),%eax
  mov    %eax,%edx
  mov    $0xc0c0c0c1,%eax
  imul   %rdx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  mov    %eax,-0x4(%rbp)
  mov    -0x4(%rbp),%edx
  mov    %edx,%ecx
  mov    $0xc0c0c0c1,%eax
  imul   %rcx,%rax
  shr    $0x20,%rax
  shr    $0x6,%eax
  imul   $0x55,%eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  lea    0x21(%rax),%edx
  mov    -0x20(%rbp),%rax
  mov    %dl,(%rax)
  mov    $0x5,%eax
L6:
  pop    %rbp
  ret
```

assistant: ```c
int coin_encode_ascii85(const unsigned char *in, unsigned char *out) {
  unsigned int data = ((unsigned int)(in[0]) << 24) | ((unsigned int)(in[1]) << 16) | ((unsigned int)(in[2]) << 8) | ((unsigned int)(in[3]));
  if (data == 0) {
    out[0] = 'z';
    return 1;
  }
  out[4] = (unsigned char)(data % 85 + '!');
  data /= 85;
  out[3] = (unsigned char)(data % 85 + '!');
  data /= 85;
  out[2] = (unsigned char)(data % 85 + '!');
  data /= 85;
  out[1] = (unsigned char)(data % 85 + '!');
  data /= 85;
  out[0] = (unsigned char)(data % 85 + '!');
  return 5;
}
```