Fastpath Speculative Parallelization ⋆

Abstract. We describe Fastpath, a system for speculative parallelization of sequential programs on conventional multicore processors. Our system distinguishes between the lead thread, which executes at almostnative speed, and speculative threads, which execute somewhat slower. This allows us to achieve nontrivial speedup, even on two-core machines. We present a mathematical model of potential speedup, parameterized by application characteristics and implementation constants. We also present preliminary results gleaned from two different Fastpath implementations, each derived from an implementation of software transactional memory.