Software Pipelining and Register Pressure in VLIW Architectures: Preconditionning Data Dependence Graphs is Experimentally Better Than Lifetime-Sensitive Scheduling

Frédéric Brault (1, 2, 3) , Benoît Dupont-De-Dinechin (2) , Sid Touati (1, 3) , Albert Cohen (1)

1 ALCHEMY - Architectures, Languages and Compilers to Harness the End of Moore Years
2 Kalray
3 PRISM - Parallélisme, Réseaux, Systèmes, Modélisation

Embedding register-pressure control in software pipelining heuristics is the dominant approach in modern back-end compilers. However, aggressive attempts at combining resource and register constraints in software pipelining have failed to scale to real-life loops, leaving weaker heuristics as the only practical solutions. We propose a decoupled approach where register pressure is controlled before scheduling, and evaluate its effectiveness in combination with three representative software pipelining algorithms. We present conclusive experiments in a production compiler on a wealth of media processing and general purpose benchmarks.

Domaines: Langage de programmation [cs.PL]

Frédéric Brault, Benoît Dupont-De-Dinechin, Sid Touati, Albert Cohen. Software Pipelining and Register Pressure in VLIW Architectures: Preconditionning Data Dependence Graphs is Experimentally Better Than Lifetime-Sensitive Scheduling. 8th Workshop on Optimizations for DSP and Embedded Systems (ODES'10), Apr 2010, Toronto, Canada. ⟨inria-00551515⟩