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

```asm
<hexdump>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x50,%rsp
  mov    %rdi,-0x38(%rbp)
  mov    %rsi,-0x40(%rbp)
  mov    %edx,-0x44(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  mov    -0x40(%rbp),%rax
  mov    %rax,-0x28(%rbp)
  cmpq   $0x0,-0x38(%rbp)
  je     L37
  mov    -0x38(%rbp),%rax
  mov    %rax,%rdi
  call   <puts@plt>
L37:
  movl   $0x0,-0x2c(%rbp)
  jmp    L54
L15:
  mov    -0x2c(%rbp),%eax
  and    $0xf,%eax
  test   %eax,%eax
  jne    L82
  cmpl   $0x0,-0x2c(%rbp)
  je     L93
  lea    -0x20(%rbp),%rax
  mov    %rax,%rsi
  lea    D3(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
L93:
  mov    -0x2c(%rbp),%eax
  mov    %eax,%esi
  lea    D33(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
L82:
  mov    -0x2c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  mov    %eax,%esi
  lea    D40(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  mov    -0x2c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  cmp    $0x1f,%al
  jbe    L108
  mov    -0x2c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  cmp    $0x7e,%al
  jbe    L18
L108:
  mov    -0x2c(%rbp),%eax
  cltd
  shr    $0x1c,%edx
  add    %edx,%eax
  and    $0xf,%eax
  sub    %edx,%eax
  cltq
  movb   $0x2e,-0x20(%rbp,%rax,1)
  jmp    L68
L18:
  mov    -0x2c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rax,%rdx
  mov    -0x2c(%rbp),%eax
  mov    %eax,%ecx
  sar    $0x1f,%ecx
  shr    $0x1c,%ecx
  add    %ecx,%eax
  and    $0xf,%eax
  sub    %ecx,%eax
  movzbl (%rdx),%edx
  cltq
  mov    %dl,-0x20(%rbp,%rax,1)
L68:
  mov    -0x2c(%rbp),%eax
  cltd
  shr    $0x1c,%edx
  add    %edx,%eax
  and    $0xf,%eax
  sub    %edx,%eax
  add    $0x1,%eax
  cltq
  movb   $0x0,-0x20(%rbp,%rax,1)
  addl   $0x1,-0x2c(%rbp)
L54:
  mov    -0x2c(%rbp),%eax
  cmp    -0x44(%rbp),%eax
  jl     L15
  jmp    L16
L10:
  lea    D38(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  addl   $0x1,-0x2c(%rbp)
L16:
  mov    -0x2c(%rbp),%eax
  and    $0xf,%eax
  test   %eax,%eax
  jne    L10
  lea    -0x20(%rbp),%rax
  mov    %rax,%rsi
  lea    D3(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  nop
  mov    -0x8(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L36
  call   <__stack_chk_fail@plt>
L36:
  leave
  ret
```

tool_calls: name: unpack_data
arguments: data_tag: D3
datatype: string
name: unpack_data
arguments: data_tag: D33
datatype: string
name: unpack_data
arguments: data_tag: D40
datatype: string
name: unpack_data
arguments: data_tag: D38
datatype: string

tool: D3:   %s


tool: D33:   %04x 

tool: D40:  %02x

tool: D38:    

assistant: ```c
void hexdump(char *desc, void *addr, int len) {
  int i;
  unsigned char buff[17];
  unsigned char *pc = addr;
  if (desc != NULL)
    printf("%s\n", desc);
  for (i = 0; i < len; i++) {
    if ((i % 16) == 0) {
      if (i != 0)
        printf("  %s\n", buff);
      printf("  %04x ", i);
    }
    printf(" %02x", pc[i]);
    if ((pc[i] < 0x20) || (pc[i] > 0x7e))
      buff[i % 16] = '.';
    else
      buff[i % 16] = pc[i];
    buff[(i % 16) + 1] = '\0';
  }
  while ((i % 16) != 0) {
    printf("   ");
    i++;
  }
  printf("  %s\n", buff);
}
```