Thus , our non-GAAP measurements are presented exclusive of stock-based compensation expense to assist management and investors in evaluating our core operating results. ii ) We present our SFAS No. 123R reconciliation of non-GAAP financial measures on a pre-tax basis because the exact tax differences related to the timing and deductibility of share-based compensation , pursuant to the adoption of SFAS No. 123R , are dependent upon the trading price of Omnicell 's common stock and the timing and exercise by employees of their stock options .