Topic
Sethi–Ullman algorithm
About: Sethi–Ullman algorithm is a research topic. Over the lifetime, 2 publications have been published within this topic receiving 19 citations.
Papers
TL;DR: The Sethi‐Ullman algorithm for register allocation finds an optimal ordering of a computation tree and two simple generalizations increase its applicability without significantly increasing its cost.
Abstract: The Sethi-Ullman algorithm for register allocation finds an optimal ordering of a computation tree. Two simple generalizations of the algorithm increase its applicability without significantly increasing its cost.
20 citations
TL;DR: A dag labeling algorithm is described which gives the minimum number of registers required to evaluate any node without any stores, and a subclass of dags is defined, the 1-load binary dags, employing a tree-like grammar, and the Sethi-Ullman algorithm is modified to include this subclass.
Abstract: A directed acyclic graph (dag) can be used to represent an arithmetic expression consisting of sequences of binary operations on arguments. The Sethi-Ullman algorithm (Journal of the ACM, Vol. 17 No. 4, pp. 715-728) generates optimal object code for a machine with N≧1 registers and unlimited memory capacity when the dag is a binary tree. We first describe a dag labeling algorithm which gives the minimum number of registers required to evaluate any node without any stores. We then define a subclass of dags, the 1-load binary dags, employing a tree-like grammar, and modify the Sethi-Ullman algorithm to include this subclass but only when N = 2 registers. The proof of optimality relies on the use of syntax directed translation schemas. Modification of the algorithm to include all dags, or to allow N > 2 registers, appears difficult.
2 citations
Performance Metrics
| Year | Papers |
|---|---|
| 1987 | 1 |
| 1975 | 1 |