article

E-path_PRE: partial redundancy elimination made easy

Author:

Dhananjay M. DhamdhereAuthors Info & Claims

ACM SIGPLAN Notices, Volume 37, Issue 8

Pages 53 - 65

https://doi.org/10.1145/596992.597004

Published: 01 August 2002 Publication History

Abstract

Partial redundancy elimination (PRE) subsumes the classical optimizations of loop invariant movement and common subexpression elimination. The original formulation of PRE involved complex bi-directional data flows and had two major deficiencies---missed optimization opportunities and redundant code movement. To eliminate redundant code movement, most current PRE approaches use a hoisting-followed-by-sinking approach. Unfortunately, this approach has a high conceptual complexity and requires complicated correctness proofs.We show that optimization by partial redundancy elimination is simpler than it has been made out to be. Its essence is the concept of eliminatability of an expression. We show that E-path_PRE, a formulation of PRE based on the concept of eliminatability paths (E-paths), is easy to understand and simple to prove correct. It uses only well-known data flow concepts of available expressions and anticipatable (i.e. very-busy) expressions to directly identify code insertion points which avoid redundant code movement. These features reduce the conceptual complexity of PRE considerably. Interestingly, performance studies show that E-path_PRE is also less expensive to perform than the closest equivalent approach to PRE. This is a sheer bonus.

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Cited By

Roy RPaleri V(2023)Lexical-based partial redundancy elimination: An optimal algorithm with improved efficiencyJournal of Computer Languages10.1016/j.cola.2023.10120475(101204)Online publication date: Jun-2023
https://doi.org/10.1016/j.cola.2023.101204
Chow F(2021)Redundancy EliminationSSA-based Compiler Design10.1007/978-3-030-80515-9_11(135-153)Online publication date: 12-Jun-2021
https://doi.org/10.1007/978-3-030-80515-9_11
Lumley JAntonacopoulos AGormish MIngold R(2010)Pre-evaluation of invariant layout in functional variable-data documentsProceedings of the 10th ACM symposium on Document engineering10.1145/1860559.1860616(251-254)Online publication date: 21-Sep-2010
https://dl.acm.org/doi/10.1145/1860559.1860616
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cover image ACM SIGPLAN Notices

ACM SIGPLAN Notices Volume 37, Issue 8

August 2002

64 pages

ISSN:0362-1340

EISSN:1558-1160

DOI:10.1145/596992

Issue’s Table of Contents

Copyright © 2002 Author.

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Association for Computing Machinery

New York, NY, United States

Publication History

Published: 01 August 2002

Published in SIGPLAN Volume 37, Issue 8

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Cited By

Roy RPaleri V(2023)Lexical-based partial redundancy elimination: An optimal algorithm with improved efficiencyJournal of Computer Languages10.1016/j.cola.2023.10120475(101204)Online publication date: Jun-2023
https://doi.org/10.1016/j.cola.2023.101204
Chow F(2021)Redundancy EliminationSSA-based Compiler Design10.1007/978-3-030-80515-9_11(135-153)Online publication date: 12-Jun-2021
https://doi.org/10.1007/978-3-030-80515-9_11
Lumley JAntonacopoulos AGormish MIngold R(2010)Pre-evaluation of invariant layout in functional variable-data documentsProceedings of the 10th ACM symposium on Document engineering10.1145/1860559.1860616(251-254)Online publication date: 21-Sep-2010
https://dl.acm.org/doi/10.1145/1860559.1860616
Saabas AUustalu T(2009)Proof optimization for partial redundancy eliminationThe Journal of Logic and Algebraic Programming10.1016/j.jlap.2009.05.00278:7(619-642)Online publication date: Aug-2009
https://doi.org/10.1016/j.jlap.2009.05.002
Saabas AUustalu THatcliff JGlück Rde Moor O(2008)Proof optimization for partial redundancy eliminationProceedings of the 2008 ACM SIGPLAN symposium on Partial evaluation and semantics-based program manipulation10.1145/1328408.1328422(91-101)Online publication date: 7-Jan-2008
https://dl.acm.org/doi/10.1145/1328408.1328422
Xue JKnoop J(2006)A fresh look at PRE as a maximum flow problemProceedings of the 15th international conference on Compiler Construction10.1007/11688839_13(139-154)Online publication date: 30-Mar-2006
https://dl.acm.org/doi/10.1007/11688839_13
Bronnikov D(2004)A practical adoption of partial redundancy eliminationACM SIGPLAN Notices10.1145/1026474.102648239:8(49-53)Online publication date: 1-Aug-2004
https://dl.acm.org/doi/10.1145/1026474.1026482
VanDrunen THosking A(2004)Value-Based Partial Redundancy EliminationCompiler Construction10.1007/978-3-540-24723-4_12(167-184)Online publication date: 2004
https://doi.org/10.1007/978-3-540-24723-4_12

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