Informatics Report Series



Related Pages

Report (by Number) Index
Report (by Date) Index
Author Index
Institute Index

Title:Eliminating Squashes Through Learning Cross-Thread Violations in Speculative Parallelization for Multiprocessors
Authors: Marcelo Cintra ; Josep Torrellas
Date:Feb 2002
Publication Title:Proceedings of HPCA 2002 (International Symposium on High-Performance Computer Architecture)
Publisher:IEEE Computer Society
Publication Type:Conference Paper Publication Status:Published
Page Nos:43-54
With speculative thread-level parallelization, codes that cannot be fully compiler-analyzed are aggressively executed in parallel. If the hardware detects a cross-thread dependence violation, it squashes offending threads and resumes execution. Unfortunately, frequent squashing cripples performance. This paper proposes a new framework of hardware mechanisms to eliminate most squashes due to data dependences in multiprocessors. The framework works by learning and predicting violations, and applying delayed disambiguation, value prediction, and stall and release. The framework is suited for directory-based multiprocessors that track memory accesses at the system level with the coarse granularity of memory lines. Simulations of a 16-processor machine show that the framework is very effective. By adding our framework to a speculative CC-NUMA with 64-byte memory lines, we speed-up applications by an average of 4.3 times. Moreover, the resulting system is even 23% faster than a machine that tracks memory accesses at the fine granularity of words a sophisticated system that is not compatible with mainstream cache coherence protocols.
Links To Paper
1st Link
Bibtex format
author = { Marcelo Cintra and Josep Torrellas },
title = {Eliminating Squashes Through Learning Cross-Thread Violations in Speculative Parallelization for Multiprocessors},
book title = {Proceedings of HPCA 2002 (International Symposium on High-Performance Computer Architecture)},
publisher = {IEEE Computer Society},
year = 2002,
month = {Feb},
pages = {43-54},
url = {},

Home : Publications : Report 

Please mail <> with any changes or corrections.
Unless explicitly stated otherwise, all material is copyright The University of Edinburgh