Linear Scan Register Allocation: Handling Lifetime Holes
2025-08-26
This post details improvements to the linear scan register allocation algorithm to handle lifetime holes. The author explains how lifetime holes arise from reducing the control flow graph to a linear instruction sequence, creating discontinuities in virtual register lifetimes. The solution involves modifying the interval data structure to support multiple disjoint ranges, allowing the identification and exploitation of these holes. The linear scan algorithm is then adapted to consider these holes during register assignment, improving register utilization. This enhances the compiler's ability to leverage register resources, ultimately boosting code performance.
Development
linear scan algorithm