user: 请将以下的汇编代码转换成C语言代码：

```asm
<dfs>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    %rdi,%r12
  mov    %rdx,%r13
  mov    %ecx,%ebx
  mov    %r9d,0x8(%rsp)
  movslq %ecx,%rax
  movslq %r8d,%rdx
  mov    (%rsi,%rax,8),%rcx
  mov    $0x0,%eax
  movzbl (%rdi),%edi
  cmp    %dil,(%rcx,%rdx,1)
  jne    L53
  mov    %rsi,%r14
  mov    %r8d,%ebp
  mov    %ebx,%esi
  imul   0x50(%rsp),%esi
  mov    %esi,0xc(%rsp)
  lea    (%rsi,%r8,1),%eax
  cltq
  shl    $0x2,%rax
  mov    %rax,(%rsp)
  lea    0x0(%r13,%rax,1),%r15
  movl   $0x1,(%r15)
  mov    $0x1,%eax
  cmpb   $0x0,0x1(%r12)
  je     L53
  test   %ebx,%ebx
  jle    L130
  lea    -0x1(%rbx),%ecx
  mov    %esi,%eax
  sub    0x50(%rsp),%eax
  add    %r8d,%eax
  cltq
  cmpl   $0x0,0x0(%r13,%rax,4)
  je     L40
L130:
  mov    0x8(%rsp),%eax
  sub    $0x1,%eax
  cmp    %ebx,%eax
  jle    L152
  lea    0x1(%rbx),%ecx
  mov    0xc(%rsp),%eax
  add    0x50(%rsp),%eax
  add    %ebp,%eax
  cltq
  cmpl   $0x0,0x0(%r13,%rax,4)
  je     L80
L152:
  test   %ebp,%ebp
  jle    L73
L34:
  mov    (%rsp),%rax
  cmpl   $0x0,-0x4(%r13,%rax,1)
  je     L135
L73:
  mov    0x50(%rsp),%eax
  lea    -0x1(%rax),%edx
  mov    $0x0,%eax
  cmp    %ebp,%edx
  jle    L114
  mov    (%rsp),%rdx
  cmpl   $0x0,0x4(%r13,%rdx,1)
  jne    L114
  lea    0x1(%r12),%rdi
  sub    $0x8,%rsp
  mov    0x58(%rsp),%eax
  push   %rax
  mov    0x18(%rsp),%r9d
  lea    0x1(%rbp),%r8d
  mov    %ebx,%ecx
  mov    %r13,%rdx
  mov    %r14,%rsi
  call   <dfs>
  add    $0x10,%rsp
  jmp    L114
L40:
  lea    0x1(%r12),%rdi
  sub    $0x8,%rsp
  mov    0x58(%rsp),%eax
  push   %rax
  mov    0x18(%rsp),%r9d
  mov    %r13,%rdx
  mov    %r14,%rsi
  call   <dfs>
  add    $0x10,%rsp
  test   %eax,%eax
  jne    L114
  jmp    L130
L80:
  lea    0x1(%r12),%rdi
  sub    $0x8,%rsp
  mov    0x58(%rsp),%eax
  push   %rax
  mov    0x18(%rsp),%r9d
  mov    %ebp,%r8d
  mov    %r13,%rdx
  mov    %r14,%rsi
  call   <dfs>
  add    $0x10,%rsp
  test   %eax,%eax
  jne    L155
  test   %ebp,%ebp
  jle    L155
  jmp    L34
L135:
  lea    0x1(%r12),%rdi
  sub    $0x8,%rsp
  mov    0x58(%rsp),%eax
  push   %rax
  mov    0x18(%rsp),%r9d
  lea    -0x1(%rbp),%r8d
  mov    %ebx,%ecx
  mov    %r13,%rdx
  mov    %r14,%rsi
  call   <dfs>
  add    $0x10,%rsp
L155:
  test   %eax,%eax
  je     L73
L114:
  movl   $0x0,(%r15)
L53:
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
bool dfs(char *word, char **board, bool *used, int row, int col, int row_size, int col_size) {
  if (board[row][col] != *word) {
    return false;
  }
  used[row * col_size + col] = true;
  if (*(word + 1) == '\0') {
    return true;
  }
  bool result = false;
  if (row > 0 && !used[(row - 1) * col_size + col]) {
    result = dfs(word + 1, board, used, row - 1, col, row_size, col_size);
  }
  if (!result && row < row_size - 1 && !used[(row + 1) * col_size + col]) {
    result = dfs(word + 1, board, used, row + 1, col, row_size, col_size);
  }
  if (!result && col > 0 && !used[row * col_size + col - 1]) {
    result = dfs(word + 1, board, used, row, col - 1, row_size, col_size);
  }
  if (!result && col < col_size - 1 && !used[row * col_size + col + 1]) {
    result = dfs(word + 1, board, used, row, col + 1, row_size, col_size);
  }
  used[row * col_size + col] = false;
  return result;
}
```