Vectorized Garbage Collection
Andrew W. Appel*
Revised September 1988
Revised February 1989
Appeared in The Journal of Supercomputing 3, 151160 (1989).
* Supported in part by NSF Grants DCR8603543 and CCR8806121, and by a Digital Equipment Corp.
Faculty Incentive Grant.
+ Supported by the NSF Research Experiences for Undergraduates program.
Garbage collection can be done in vector mode on supercomputers like the Cray2 and the Cyber
205. Both copying collection and markandsweep can be expressed as breadthfirst searches in
which the ``queue'' can be processed in parallel. We have designed a copying garbage collector
whose inner loop works entirely in vector mode. We give performance measurements of the algo