user: 下面的汇编指令对应的C源代码是什么：

```asm
<encode_base64>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x18(%rbp)
  mov    %rsi,-0x20(%rbp)
  mov    %rdx,-0x28(%rbp)
  mov    %rcx,-0x30(%rbp)
  mov    %r8d,-0x34(%rbp)
  mov    %r9d,-0x38(%rbp)
  movq   $0x0,-0x8(%rbp)
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  shr    $0x2,%al
  mov    %al,-0x9(%rbp)
  movzbl -0x9(%rbp),%eax
  cltq
  lea    D37(%rip),%rdx
  movzbl (%rax,%rdx,1),%ecx
  mov    -0x18(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x18(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x4,%eax
  and    $0x30,%eax
  mov    %eax,%edx
  mov    -0x20(%rbp),%rax
  add    $0x1,%rax
  movzbl (%rax),%eax
  shr    $0x4,%al
  or     %edx,%eax
  mov    %al,-0x9(%rbp)
  movzbl -0x9(%rbp),%eax
  cltq
  lea    D37(%rip),%rdx
  movzbl (%rax,%rdx,1),%ecx
  mov    -0x18(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x18(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x20(%rbp),%rax
  add    $0x1,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x2,%eax
  and    $0x3c,%eax
  mov    %eax,%edx
  mov    -0x20(%rbp),%rax
  add    $0x2,%rax
  movzbl (%rax),%eax
  shr    $0x6,%al
  or     %edx,%eax
  mov    %al,-0x9(%rbp)
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cmp    $0x1,%eax
  jle    L55
  movzbl -0x9(%rbp),%eax
  cltq
  lea    D37(%rip),%rdx
  movzbl (%rax,%rdx,1),%eax
  mov    %eax,%edx
  jmp    L28
L55:
  movzbl D17(%rip),%edx
L28:
  mov    -0x18(%rbp),%rax
  lea    0x1(%rax),%rcx
  mov    %rcx,-0x18(%rbp)
  mov    %dl,(%rax)
  mov    -0x20(%rbp),%rax
  add    $0x2,%rax
  movzbl (%rax),%eax
  and    $0x3f,%eax
  mov    %al,-0x9(%rbp)
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cmp    $0x2,%eax
  jle    L66
  movzbl -0x9(%rbp),%eax
  cltq
  lea    D37(%rip),%rdx
  movzbl (%rax,%rdx,1),%eax
  mov    %eax,%edx
  jmp    L50
L66:
  movzbl D17(%rip),%edx
L50:
  mov    -0x18(%rbp),%rax
  lea    0x1(%rax),%rcx
  mov    %rcx,-0x18(%rbp)
  mov    %dl,(%rax)
  addq   $0x10,-0x30(%rbp)
  movq   $0x4,-0x8(%rbp)
  mov    -0x30(%rbp),%rax
  mov    (%rax),%eax
  cmp    $0x4b,%eax
  jle    L64
  cmpl   $0x0,-0x34(%rbp)
  je     L64
  cmpl   $0x0,-0x38(%rbp)
  je     L58
  mov    -0x18(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x18(%rbp)
  movb   $0xd,(%rax)
L58:
  mov    -0x18(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x18(%rbp)
  movb   $0xa,(%rax)
  mov    -0x30(%rbp),%rax
  movl   $0x0,(%rax)
  addq   $0x1,-0x8(%rbp)
L64:
  mov    -0x28(%rbp),%rax
  movl   $0x0,(%rax)
  mov    -0x8(%rbp),%rax
  pop    %rbp
  ret
```

tool_calls: name: unpack_data
arguments: label: D37
datatype: string
name: unpack_data
arguments: label: D17
datatype: byte

tool: D37: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/

tool: D17: 61

assistant: ```c
size_t encode_base64(char *ostr, unsigned char *inbuf, int *inbuf_size, int *line_len, int line_breaks, int cr) {
  static const unsigned char vec[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  static const char padding = '=';
  unsigned char out;
  size_t len = 0;
  out = (unsigned char)((*(inbuf + 0) & 0xFC) >> 2);
  *ostr++ = vec[out];
  out = (unsigned char)(((*(inbuf + 0) & 0x03) << 4) | (*(inbuf + 1) >> 4));
  *ostr++ = vec[out];
  out = (unsigned char)(((*(inbuf + 1) & 0x0F) << 2) | (*(inbuf + 2) >> 6));
  *ostr++ = (*inbuf_size > 1 ? vec[out] : padding);
  out = (unsigned char)(*(inbuf + 2) & 0x3F);
  *ostr++ = (*inbuf_size > 2 ? vec[out] : padding);
  line_len += 4;
  len = 4;
  if ((*line_len >= 76) && line_breaks) {
    if (cr)
      *ostr++ = '\r';
    *ostr++ = '\n';
    *line_len = 0;
    len++;
  }
  *inbuf_size = 0;
  return len;
}
```