Survey on Combinatorial Register Allocation and Instruction Scheduling

Abstract

Register allocation (mapping variables to processor registers or memory) and instruction scheduling (reordering instructions to increase instruction-level parallelism) are essential tasks for generating efficient assembly code in a compiler. In the past three decades, combinatorial optimization has emerged as an alternative to traditional, heuristic algorithms for these two tasks. Combinatorial optimization approaches can deliver optimal solutions according to a model, can precisely capture trade-offs between conflicting decisions, and are more flexible at the expense of increased compilation time. This article provides an exhaustive literature review and a classification of combinatorial optimization approaches to register allocation and instruction scheduling, with a focus on the techniques that are most applied in this context: integer programming, constraint programming, partitioned Boolean quadratic programming, and enumeration. Researchers in compilers and combinatorial optimization can benefit from identifying developments, trends, and challenges in the area; compiler practitioners may discern opportunities and grasp the potential benefit of applying combinatorial optimization.

Algorithms for Pre-Compiling Programs by Parallel Compilers

“…Other studies such as [9][10][11][12] investigate the register allocation and instruction assignment.…”

Pre-compiling Parallel Algorithms for Compilers into a Network

“…Other studies such in [19], [18], [4] and [22] investigate the register allocation and instruction scheduling.…”