Trace Scheduling

Definition

Trace scheduling is a global acyclic instruction scheduling technique in which the scheduling region consists of a linear acyclic sequence of basic blocks embedded in the control flow graph. Trace scheduling differs from other global acyclic scheduling techniques by allowing the scheduling region to be entered after the first instruction.

Trace scheduling was the first global instruction scheduling technique that was proposed and successfully implemented in both research and commercial compilers. By demonstrating that simple microcode operations could be statically compacted and scheduled on multi-issue hardware, trace scheduling provided the basis for making large amounts of instruction-level parallelism practical. Its first commercial implementation demonstrated that commercial codes could be statically compiled for multi-issue architectures, and thus greatly influenced and contributed to the performance of superscalar architectures. Today, the ideas