Convertible Notes, Non-cash interest expense is calculated pursuant to FASB's Accounting Standards Codification Topic 470: Debt.

Diluted shares outstanding can vary as a result of, among other things, the actual exercise of options or vesting of restricted stock units, the incremental dilutive shares from the Company's convertible senior subordinated notes, and the repurchase or the issuance of stock or convertible notes or the sale of treasury shares. In periods when the quarterly average stock price per share exceeds $20.72 for the 1.625% Notes and $52.97 for the 0% Notes, the non-GAAP diluted share count and non-GAAP net income per share include the anti-dilutive impact of the Company’s hedge transactions issued concurrently with the 1.625% Notes and the 0% Notes, respectively. At an average stock price per share between $20.72 and $30.70 for the 1.625% Notes and $52.97 and $74.34 for the 0% Notes, the hedging activity offsets the potentially dilutive effect of the 1.625% Notes and 0% Notes, respectively. In periods when the quarterly average stock price exceeds $30.70 for the 1.625% Notes, and $74.34 for the 0% Notes, the dilutive impact of the warrants issued concurrently with such notes are included in the diluted shares outstanding. Both GAAP and non-GAAP diluted share counts are based on the Company’s stock price as of October 1, 2021.

Special items may include: amortization of acquisition-related intangibles; expensing of appraised inventory fair market value step-up; non-recurring facility costs, purchased in-process research and development expenses; restructuring, asset impairments and other, net; goodwill impairment charges; gains and losses on debt prepayment; non-cash interest expense; actuarial (gains) losses on pension plans and other pension benefits; and certain other special items, as necessary. These special items are out of our control and could change significantly from period to period. As a result, we are not able to reasonably estimate and separately present the individual impact or probable significance of these special items, and we are similarly unable to provide a reconciliation of the non-GAAP measures. The reconciliation that is unavailable would include a forward-looking income statement, balance sheet and statement of cash flows in accordance with GAAP. For this reason, we use a projected range of the aggregate amount of special items in order to calculate our projected non-GAAP operating expense outlook.