user: Demonstrate the C code that generates the assembly output below:

```asm
<realpath>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,-0x88(%rbp)
  mov    %rsi,-0x90(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  mov    %rsp,%rax
  mov    %rax,%r13
  movl   $0x0,-0x78(%rbp)
  movl   $0x0,-0x74(%rbp)
  mov    D85(%rip),%rax
  mov    (%rax),%ebx
  movslq %ebx,%rax
  sub    $0x1,%rax
  mov    %rax,-0x58(%rbp)
  movslq %ebx,%rax
  mov    %rax,%r14
  mov    $0x0,%r15d
  movslq %ebx,%r12
  movslq %ebx,%rax
  mov    %rax,%r10
  mov    $0x0,%r11d
  movslq %ebx,%rax
  mov    %rax,%r8
  mov    $0x0,%r9d
  movslq %ebx,%rax
  lea    (%rax,%rax,1),%rdx
  mov    $0x10,%eax
  sub    $0x1,%rax
  add    %rdx,%rax
  mov    $0x10,%esi
  mov    $0x0,%edx
  div    %rsi
  imul   $0x10,%rax,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffff000,%rcx
  mov    %rsp,%rdx
  sub    %rcx,%rdx
L386:
  cmp    %rdx,%rsp
  je     L252
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L386
L252:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L448
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L448:
  mov    %rsp,%rax
  add    $0x0,%rax
  mov    %rax,-0x50(%rbp)
  cmpq   $0x0,-0x88(%rbp)
  jne    L260
  mov    D6(%rip),%rax
  mov    (%rax),%edx
  mov    D155(%rip),%rax
  mov    %edx,(%rax)
  mov    $0x0,%eax
  jmp    L56
L260:
  cmpq   $0x0,-0x90(%rbp)
  jne    L58
  mov    D85(%rip),%rax
  mov    (%rax),%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,-0x90(%rbp)
  mov    -0x90(%rbp),%rax
  mov    %rax,-0x60(%rbp)
  cmpq   $0x0,-0x90(%rbp)
  jne    L366
  mov    $0x0,%eax
  jmp    L56
L58:
  movq   $0x0,-0x60(%rbp)
L366:
  mov    -0x90(%rbp),%rax
  mov    %rax,-0x68(%rbp)
  mov    -0x88(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  jne    L315
  mov    -0x68(%rbp),%rax
  movb   $0x0,(%rax)
  mov    D80(%rip),%rax
  mov    (%rax),%edx
  mov    D155(%rip),%rax
  mov    %edx,(%rax)
  jmp    L82
L315:
  mov    -0x88(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2f,%al
  je     L114
  cmpq   $0x0,-0x90(%rbp)
  je     L200
  mov    D85(%rip),%rax
  mov    (%rax),%edx
  mov    -0x90(%rbp),%rax
  mov    %edx,%esi
  mov    %rax,%rdi
  call   <getcwd@plt>
  test   %rax,%rax
  jne    L200
  mov    -0x68(%rbp),%rax
  movb   $0x2e,(%rax)
  mov    -0x68(%rbp),%rax
  add    $0x1,%rax
  movb   $0x0,(%rax)
  jmp    L82
L200:
  mov    -0x90(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %rax,-0x48(%rbp)
  cmpq   $0x1,-0x48(%rbp)
  jbe    L114
  mov    -0x48(%rbp),%rax
  add    %rax,-0x68(%rbp)
  jmp    L195
L114:
  nop
L68:
  jmp    L195
L417:
  addq   $0x1,-0x88(%rbp)
L195:
  mov    -0x88(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2f,%al
  je     L417
  mov    -0x88(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  jne    L453
  mov    -0x68(%rbp),%rax
  cmp    -0x90(%rbp),%rax
  jne    L330
  mov    -0x68(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x68(%rbp)
  movb   $0x2f,(%rax)
L330:
  mov    -0x68(%rbp),%rax
  movb   $0x0,(%rax)
  mov    -0x90(%rbp),%rax
  jmp    L56
L453:
  mov    -0x88(%rbp),%rax
  mov    %rax,-0x70(%rbp)
L334:
  addq   $0x1,-0x70(%rbp)
  mov    -0x70(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2f,%al
  je     L478
  mov    -0x70(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  jne    L334
L478:
  mov    -0x88(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2e,%al
  jne    L346
  mov    -0x70(%rbp),%rax
  sub    -0x88(%rbp),%rax
  cmp    $0x1,%rax
  jne    L85
  mov    -0x70(%rbp),%rax
  mov    %rax,-0x88(%rbp)
  jmp    L68
L85:
  mov    -0x88(%rbp),%rax
  add    $0x1,%rax
  movzbl (%rax),%eax
  cmp    $0x2e,%al
  jne    L346
  mov    -0x70(%rbp),%rax
  sub    -0x88(%rbp),%rax
  cmp    $0x2,%rax
  jne    L346
  mov    -0x68(%rbp),%rax
  cmp    -0x90(%rbp),%rax
  je     L6
  jmp    L158
L55:
  nop
L158:
  subq   $0x1,-0x68(%rbp)
  mov    -0x68(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2f,%al
  jne    L55
L6:
  mov    -0x70(%rbp),%rax
  mov    %rax,-0x88(%rbp)
  jmp    L68
L346:
  mov    -0x68(%rbp),%rax
  sub    -0x90(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    -0x70(%rbp),%rax
  add    %rdx,%rax
  sub    -0x88(%rbp),%rax
  mov    %rax,%rdx
  mov    D85(%rip),%rax
  mov    (%rax),%eax
  cltq
  cmp    %rax,%rdx
  jl     L240
  mov    D179(%rip),%rax
  mov    (%rax),%edx
  mov    D155(%rip),%rax
  mov    %edx,(%rax)
  mov    -0x68(%rbp),%rax
  cmp    -0x90(%rbp),%rax
  jne    L336
  mov    -0x68(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x68(%rbp)
  movb   $0x2f,(%rax)
L336:
  mov    -0x68(%rbp),%rax
  movb   $0x0,(%rax)
  jmp    L82
L240:
  mov    -0x68(%rbp),%rax
  movb   $0x2f,(%rax)
  mov    -0x70(%rbp),%rax
  sub    -0x88(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x68(%rbp),%rax
  lea    0x1(%rax),%rcx
  mov    -0x88(%rbp),%rax
  mov    %rax,%rsi
  mov    %rcx,%rdi
  call   <memcpy@plt>
  mov    -0x70(%rbp),%rax
  add    $0x1,%rax
  sub    -0x88(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x68(%rbp),%rax
  add    %rdx,%rax
  movb   $0x0,(%rax)
  lea    -0x7c(%rbp),%rdx
  mov    -0x90(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <lstat@plt>
  cmp    $0xffffffff,%eax
  je     L201
  mov    -0x7c(%rbp),%eax
  mov    %eax,%edi
  call   <S_ISLNK@plt>
  test   %rax,%rax
  je     L182
  mov    -0x74(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x74(%rbp)
  mov    D132(%rip),%rdx
  mov    (%rdx),%edx
  cmp    %edx,%eax
  jl     L304
  mov    D97(%rip),%rax
  mov    (%rax),%edx
  mov    D155(%rip),%rax
  mov    %edx,(%rax)
  jmp    L82
L304:
  mov    %ebx,%eax
  sub    $0x1,%eax
  mov    %eax,%edx
  mov    -0x78(%rbp),%eax
  cltq
  imul   %r12,%rax
  mov    %rax,%rcx
  mov    -0x50(%rbp),%rax
  add    %rax,%rcx
  mov    -0x90(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <readlink@plt>
  mov    %rax,-0x40(%rbp)
  cmpq   $0x0,-0x40(%rbp)
  jne    L225
  mov    D80(%rip),%rax
  mov    (%rax),%edx
  mov    D155(%rip),%rax
  mov    %edx,(%rax)
  jmp    L82
L225:
  mov    -0x70(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %rax,-0x48(%rbp)
  mov    -0x48(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  lea    0x1(%rax),%rdx
  movslq %ebx,%rax
  cmp    %rax,%rdx
  jbe    L311
  mov    D179(%rip),%rax
  mov    (%rax),%edx
  mov    D155(%rip),%rax
  mov    %edx,(%rax)
  jmp    L82
L311:
  mov    -0x48(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    -0x78(%rbp),%eax
  cltq
  imul   %r12,%rax
  mov    %rax,%rcx
  mov    -0x40(%rbp),%rax
  add    %rax,%rcx
  mov    -0x50(%rbp),%rax
  add    %rax,%rcx
  mov    -0x70(%rbp),%rax
  mov    %rax,%rsi
  mov    %rcx,%rdi
  call   <memcpy@plt>
  mov    -0x78(%rbp),%eax
  cltq
  imul   %r12,%rax
  mov    %rax,%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x88(%rbp)
  xorl   $0x1,-0x78(%rbp)
  mov    -0x88(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2f,%al
  jne    L68
  mov    -0x90(%rbp),%rax
  mov    %rax,-0x68(%rbp)
  jmp    L68
L182:
  mov    -0x70(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2f,%al
  jne    L34
  mov    -0x7c(%rbp),%eax
  mov    %eax,%edi
  call   <S_ISDIR@plt>
  test   %eax,%eax
  jne    L34
  mov    D53(%rip),%rax
  mov    (%rax),%edx
  mov    D155(%rip),%rax
  mov    %edx,(%rax)
  jmp    L82
L34:
  mov    -0x70(%rbp),%rax
  add    $0x1,%rax
  sub    -0x88(%rbp),%rax
  add    %rax,-0x68(%rbp)
  mov    -0x70(%rbp),%rax
  mov    %rax,-0x88(%rbp)
  jmp    L68
L201:
  nop
L82:
  mov    -0x60(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  mov    $0x0,%eax
L56:
  mov    %r13,%rsp
  mov    -0x38(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L377
  call   <__stack_chk_fail@plt>
L377:
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

assistant: ```c
char *realpath(const char *path, char *resolved) {
  struct stat sb;
  int idx = 0, nlnk = 0;
  const char *q;
  char *p, wbuf[2][MAXPATHLEN], *fres;
  size_t len;
  ssize_t n;
  if (path == NULL) {
    errno = EINVAL;
    return NULL;
  }
  if (resolved == NULL) {
    fres = resolved = malloc(MAXPATHLEN);
    if (resolved == NULL)
      return NULL;
  } else
    fres = NULL;
  p = resolved;
  if (*path == '\0') {
    *p = '\0';
    errno = ENOENT;
    goto out;
  }
  if (*path != '/') {
    if (resolved && getcwd(resolved, MAXPATHLEN) == NULL) {
      p[0] = '.';
      p[1] = '\0';
      goto out;
    }
    len = strlen(resolved);
    if (len > 1)
      p += len;
  }
loop:
  while (*path == '/')
    path++;
  if (*path == '\0') {
    if (p == resolved)
      *p++ = '/';
    *p = '\0';
    return resolved;
  }
  q = path;
  do
    q++;
  while (*q != '/' && *q != '\0');
  if (path[0] == '.') {
    if (q - path == 1) {
      path = q;
      goto loop;
    }
    if (path[1] == '.' && q - path == 2) {
      if (p != resolved)
        while (*--p != '/')
          continue;
      path = q;
      goto loop;
    }
  }
  if (p - resolved + 1 + q - path + 1 > MAXPATHLEN) {
    errno = ENAMETOOLONG;
    if (p == resolved)
      *p++ = '/';
    *p = '\0';
    goto out;
  }
  p[0] = '/';
  memcpy(&p[1], path, q - path);
  p[1 + q - path] = '\0';
  if (lstat(resolved, &sb) == -1)
    goto out;
  if (S_ISLNK(sb.st_mode)) {
    if (nlnk++ >= MAXSYMLINKS) {
      errno = ELOOP;
      goto out;
    }
    n = readlink(resolved, wbuf[idx], sizeof(wbuf[0]) - 1);
    if (n < 0)
      goto out;
    if (n == 0) {
      errno = ENOENT;
      goto out;
    }
    if (n + (len = strlen(q)) + 1 > sizeof(wbuf[0])) {
      errno = ENAMETOOLONG;
      goto out;
    }
    memcpy(&wbuf[idx][n], q, len + 1);
    path = wbuf[idx];
    idx ^= 1;
    if (*path == '/')
      p = resolved;
    goto loop;
  }
  if (*q == '/' && !S_ISDIR(sb.st_mode)) {
    errno = ENOTDIR;
    goto out;
  }
  p += 1 + q - path;
  path = q;
  goto loop;
out:
  free(fres);
  return NULL;
}
```