Learning heuristics for basic block instruction scheduling

Instruction scheduling is an important step for improving the performance of object code produced by a compiler. A fundamental problem that arises in instruction scheduling is to find a minimum length schedule for a basic block--a straight-line sequence of code with a single entry point and a single exit point--subject to precedence, latency, and resource constraints. Solving the problem exactly is known to be difficult, and most compilers use a greedy list scheduling algorithm coupled with a heuristic. The heuristic is usually hand-crafted, a potentially time-consuming process. In contrast, we present a study on automatically learning good heuristics using techniques from machine learning. In our study, a recently proposed optimal basic block scheduler was used to generate the machine learning training data. A decision tree learning algorithm was then used to induce a simple heuristic from the training data. The automatically constructed decision tree heuristic was compared against a...

• Type: Journal
• Year: 2008
• Where: HEURISTICS
• Authors: Abid M. Malik, Tyrel Russell, Michael Chase, Peter van Beek
• Keywords: Basic Blocks, Heuristic, HEURISTICS 2008, Instruction Scheduling