Stock-Based Compensation

Stock-based compensation expense was attributable to:



	Three Months Ended
	December 30, 2017		December 31, 2016
	(In thousands)
Stock options	$	1,177	$	550
Restricted stock units, including performance based awards	7,465		11,427
Total	$	8,642	$	11,977

Stock-based compensation expense was recognized as follows:



	Three Months Ended
	December 30, 2017		December 31, 2016
	(In thousands)
Cost of sales	$	2,448	$	2,864
Selling, general and administrative	6,164		8,840
Research and development	30		273
Total	$	8,642	$	11,977

As of December 30, 2017, an aggregate of 9.1 million shares were authorized for future issuance under the Company's stock plans, of which 6.9 million of such shares were issuable upon exercise of outstanding options and delivery of shares upon vesting of restricted stock units and 2.2 million shares of common stock were available for future grant.

Stock Options

Stock option activity was as follows:



	Number of Shares		Weighted- Average Exercise Price ($)	Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value of In-The-Money Options ($)
	(In thousands)				(In thousands)
Outstanding as of September 30, 2017	3,568		11.83	3.82	90,327
Granted	200		38.45
Exercised/Cancelled/Forfeited/Expired	(234	)	12.43
Outstanding as of December 30, 2017	3,534		13.30	4.06	62,548
Vested and expected to vest as of December 30, 2017	3,530		13.29	4.06	62,519
Exercisable as of December 30, 2017	3,314		11.93	3.74	62,097

The aggregate intrinsic value in the preceding table represents the total pre-tax intrinsic value of in-the-money options that would have been received by the option holders had all option holders exercised such options at the Company's closing stock price on the date indicated.

As of December 30, 2017, unrecognized compensation expense of $4 million is expected to be recognized over a weighted average period of 1 year.

Restricted Stock Units

Activity with respect to the Company's restricted stock units was as follows:



	Number of Shares		Weighted- Average Grant Date Fair Value ($)	Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value ($)
	(In thousands)				(In thousands)
Outstanding as of September 30, 2017	3,359		27.56	1.51	124,800
Granted	694		35.86
Vested/Forfeited/Cancelled	(699	)	25.76
Outstanding as of December 30, 2017	3,354		29.65	1.69	102,465
Expected to vest as of December 30, 2017	2,521		28.83	1.65	77,002

As of December 30, 2017, unrecognized compensation expense of $48 million is expected to be recognized over a weighted average period of 2 years. Additionally, as of December 30, 2017, unrecognized compensation expense related to performance-based restricted stock units for which achievement of the performance criteria is not currently considered probable was $20 million.