Global code motion/global value numbering

Abstract

We believe that optimizing compilers should treat the machine-independent optimizations (e.g., conditional constant propagation, global value numbering) and code motion issues separately.’ Removing the code motion requirements from the machine-independent optimization allows stronger optimizations using simpler algorithms. Preserving a legal schedule is one of the prime sources of complexity in algorithms like PRE [18, 13] or global congruence finding [2, 20].