user: What would the C source look like for the assembly code provided here?

```asm
<LookupStringInFixedSet>:
  endbr64
  push   %r15
  mov    %rdx,%rax
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  lea    (%rcx,%rax,1),%rbp
  push   %rbx
  lea    (%rdi,%rsi,1),%rbx
  sub    $0x48,%rsp
  mov    %rdx,0x8(%rsp)
  lea    0x28(%rsp),%r12
  lea    0x20(%rsp),%r13
  mov    %fs:0x28,%rdx
  mov    %rdx,0x38(%rsp)
  xor    %edx,%edx
  mov    %rdi,0x20(%rsp)
  mov    %rdi,0x28(%rsp)
  movq   $0x0,0x30(%rsp)
  nop
L161:
  mov    %r12,%rdx
  mov    %rbx,%rsi
  mov    %r13,%rdi
  call   <GetNextOffset@plt>
  test   %rax,%rax
  je     L48
  mov    0x28(%rsp),%rdi
  cmp    %rbp,0x8(%rsp)
  je     L156
  mov    %rbx,%rsi
  xor    %r14d,%r14d
  call   <IsEOL@plt>
  test   %eax,%eax
  je     L44
L128:
  mov    0x8(%rsp),%rdx
  mov    0x30(%rsp),%r8
  mov    0x28(%rsp),%rdi
  cmp    %rbp,%rdx
  je     L21
  mov    %r8,%rcx
  mov    %rbx,%rsi
  call   <IsEndCharMatch@plt>
  test   %eax,%eax
  jne    L98
L147:
  test   %r14d,%r14d
  je     L161
L48:
  mov    $0xffffffff,%eax
L95:
  mov    0x38(%rsp),%rdx
  sub    %fs:0x28,%rdx
  jne    L87
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopw   0x0(%rax,%rax,1)
L156:
  mov    0x30(%rsp),%r8
  xor    %r14d,%r14d
L21:
  lea    0x1c(%rsp),%rcx
  mov    %r8,%rdx
  mov    %rbx,%rsi
  call   <GetReturnValue@plt>
  test   %rax,%rax
  je     L147
  mov    0x1c(%rsp),%eax
  jmp    L95
  nopl   0x0(%rax,%rax,1)
L98:
  lea    0x30(%rsp),%rdx
  lea    0x8(%rsp),%rsi
  mov    %r12,%rdi
  call   <NextPos@plt>
  mov    0x28(%rsp),%rax
  mov    %rax,0x20(%rsp)
  jmp    L161
  nopl   0x0(%rax)
L44:
  mov    0x30(%rsp),%rcx
  mov    0x8(%rsp),%rdx
  mov    %rbx,%rsi
  mov    0x28(%rsp),%rdi
  call   <IsMatch@plt>
  test   %eax,%eax
  je     L161
  lea    0x30(%rsp),%r15
  lea    0x8(%rsp),%r14
  mov    %r12,%rdi
  mov    %r15,%rdx
  mov    %r14,%rsi
  call   <NextPos@plt>
  jmp    L141
  nopl   0x0(%rax)
L116:
  mov    0x8(%rsp),%rdx
  mov    0x30(%rsp),%r8
  mov    0x28(%rsp),%rdi
  cmp    %rbp,%rdx
  je     L71
  mov    %r8,%rcx
  mov    %rbx,%rsi
  call   <IsMatch@plt>
  test   %eax,%eax
  je     L48
  mov    %r15,%rdx
  mov    %r14,%rsi
  mov    %r12,%rdi
  call   <NextPos@plt>
L141:
  mov    0x28(%rsp),%rdi
  mov    %rbx,%rsi
  call   <IsEOL@plt>
  test   %eax,%eax
  je     L116
  mov    $0x1,%r14d
  jmp    L128
  nopl   0x0(%rax)
L71:
  mov    $0x1,%r14d
  jmp    L21
L87:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
int LookupStringInFixedSet(const unsigned char *graph, size_t length, const char *key, size_t key_length) {
  const unsigned char *pos = graph;
  const unsigned char *end = graph + length;
  const unsigned char *offset = pos;
  const char *key_end = key + key_length;
  const char *multibyte_start = 0;
  while (GetNextOffset(&pos, end, &offset)) {
    int did_consume = 0;
    if (key != key_end && !IsEOL(offset, end)) {
      if (!IsMatch(offset, end, key, multibyte_start))
        continue;
      did_consume = 1;
      NextPos(&offset, &key, &multibyte_start);
      while (!IsEOL(offset, end) && key != key_end) {
        if (!IsMatch(offset, end, key, multibyte_start))
          return -1;
        NextPos(&offset, &key, &multibyte_start);
      }
    }
    if (key == key_end) {
      int return_value;
      if (GetReturnValue(offset, end, multibyte_start, &return_value))
        return return_value;
      if (did_consume)
        return -1;
      continue;
    }
    if (!IsEndCharMatch(offset, end, key, multibyte_start)) {
      if (did_consume)
        return -1;
      continue;
    }
    NextPos(&offset, &key, &multibyte_start);
    pos = offset;
  }
  return -1;
}
```