To supplement Cadence’s financial results presented on a GAAP basis, Cadence management uses non-GAAP measures that it believes are helpful in understanding Cadence’s performance. One such measure is non-GAAP net income, which is a financial measure not calculated under GAAP. Non-GAAP net income is calculated by Cadence management by taking GAAP net income and excluding, as applicable, amortization of intangible assets, stock-based compensation expense, acquisition and integration-related costs including retention expenses, investment gains or losses, income or expenses related to Cadence’s non-qualified deferred compensation plan, restructuring and other significant items not directly related to Cadence’s core business operations, and the income tax effect of non-GAAP pre-tax adjustments.

Cadence management uses non-GAAP net income because it excludes items that are generally not directly related to the performance of Cadence’s core business operations and therefore provides supplemental information to Cadence management and investors regarding the performance of the business operations, facilitates comparisons to the historical operating results and allows the review of Cadence's business from the same perspective as Cadence management, including forecasting and budgeting.

The following tables reconcile the specific items excluded from GAAP operating margin, GAAP net income and GAAP net income per diluted share in the calculation of non-GAAP operating margin, non-GAAP net income and non-GAAP net income per diluted share for the periods shown below: