With regard to the correction of accounting errors, what is the difference between U.S. GAAP and IFRS?

1. With regard to the correction of accounting errors, what is the difference between U.S. GAAP and IFRS?
2, For financial reporting, a reporting entity can be a single company, or it can be a group of companies that reports a single set of financial statements. When changes occur that cause the financial statements to be those of a different reporting entity, we account for the situation as a change in reporting entity. What are the situations deemed to constitute a change in reporting entity?