Procedural Abstraction with Reverse Prefix Trees
Schaeckeler, S.
Shang, W.
Dept. of Comput. Eng., Santa Clara Univ., Santa Clara, CA;
This paper appears in: Code Generation and Optimization, 2009. CGO 2009. International Symposium on
Publication Date: 22-25 March 2009
On page(s): 243-253
Location: Seattle, WA,
ISBN: 978-0-7695-3576-0
INSPEC Accession Number: 10627034
Digital Object Identifier: 10.1109/CGO.2009.25
Current Version Published: 2009-05-05
Abstract
For memory constrained environments like embedded systems, optimization for size is often as important as, if not more important than, optimization for execution speed. A common technique for compacting code is procedural abstraction. Equivalent code fragments are identified and abstracted into a procedure. The standard algorithm for identifying these fragments is based on suffix trees. We propose in this paper the calculation of suffix trees over the program text not in the common top-down fashion, but reversed, i.e. bottom-up. With this simple modification, not only equivalent fragments can be identified, but also fragments equivalent to (possibly often differently long) suffixes of the longest fragments. A longest fragment is then abstracted, and all fragments are replaced by procedure calls to their corresponding start instruction somewhere in the abstracted procedure. This allows us to harvest more and longer fragments than with standard suffix trees, improving code size reductions on average by 8.277% over standard suffix trees.
Index
Terms
Available to subscribers and IEEE members.
References
Available to subscribers and IEEE members.
Citing Documents
Available to subscribers and IEEE members.
Cart
