Execution-Based Scheduling for VLIW Architectures

We describe a new dynamic software scheduling technique for VLIW architectures, which compiles into VLIW code the program paths that are actually executed. Unlike trace processors, or DIF, the technique executes operations speculatively on multiple paths through the code, is resilient to branch mispredictions, and can achieve very large dynamic window sizes necessary for high ILP. Aggressive optimizations are applied to frequently executed portions of the code. Encouraging performance results were obtained on SPECint95 and TPC-C. The technique can be used for binary translation for achieving architectural compatibility with an existing processor, or as a VLIW scheduling technique in its own right.