A Fast Cutting-Plane Algorithm for Optimal Coalescing

Abstract. Recent work has shown that the subtasks of register allocation (spilling, register assignment, and coalescing) can be completely separated. This work presents an algorithm for the coalescing subproblem that relies on this separation. The algorithm uses 0/1 Linear Programming (ILP), a general-purpose optimization technique, to derive optimal solutions. We provide the first optimal solutions for a benchmark called “Optimal Coalescing Challenge”, i.e., our ILP model outperforms previous approaches. Additionally, we use these optimal solutions to assess the quality of well-known heuristics. A second benchmark on SPEC CPU2000 programs emphasizes the practicality of our algorithm.

• Type: Conference
• Year: 2007
• Where: CC
• Authors: Daniel Grund, Sebastian Hack
• Keywords: CC 2007, Optimal Coalescing Challenge, Optimal Solutions, Programming Languages, first Optimal Solutions