Copy or Discard execution model for speculative parallelization on multicores

The advent of multicores presents a promising opportunity for speeding up sequential programs via profile-based speculative parallelization of these programs. In this paper we present a novel solution for efficiently supporting software speculation on multicore processors. We propose the Copy or Discard (CorD) execution model in which the state of speculative parallel threads is maintained separately from the nonspeculative computation state. If speculation is successful, the results of the speculative computation are committed by copying them into the non-speculative state. If misspeculation is detected, no costly state recovery mechanisms are needed as the speculative state can be simply discarded. Optimizations are proposed to reduce the cost of data copying between nonspeculative and speculative state. A lightweight mechanism that maintains version numbers for non-speculative data values enables misspeculation detection. We also present an algorithm for profile-based speculativ...

• Type: Conference
• Year: 2008
• Where: MICRO
• Authors: Chen Tian, Min Feng, Vijay Nagarajan, Rajiv Gupta
• Keywords: Hardware, MICRO 2008, Profile-based Speculative Parallelization, Speculative, Speculative Parallelization