Incremental register reallocation
Mary P. Bivens, Mary Lou Soffa · Software Practice and Experience · 1990
Abstract Current compiler technology performs extensive code transformations either to parallelize code or to perform optimizations that reduce space or time. The cost of the analyses for these transformations is high and is further magnified when edits are made, forcing complete recompilation. By extending the concept of incremental compilation to include fine‐grained, high‐quality target code generation, we develop techniques that reuse the information created by an optimizing compiler to incorporate program edits efficiently into optimized target code. Our techniques include developing models of register usage for both local and global register allocation schemes and algorithms for incrementally updating these structures in response to an editing change. Based on these changes, the target code is updated. As graph colouring is a widely accepted register allocation scheme, we present techniques to rebuild and recolour interference graphs incrementally. Results from experiments that compare the performance of the incremental target code generator with its non‐incremental counterpart are reported, showing a saving when incorporating changes incrementally.