California at Berkeleys HYPER System

The University of California at Berkeley s HYPER system is aimed at synthesizing real-time applications, and includes transformations, scheduling, data path synthesis, module binding, and controller design. 

An extended version of SILAGE, a signal-flow oriented language designed for describing DSP algorithms. 

Applies optimizing compiler transformations, including constant folding, common subexpression elimination, dead code elimination, loop retiming, loop pipelining, loop unrolling, and loop jamming. 

the upper and lower bounds on the number of fiinctional units, registers, and buses is calculated, to determine the initial number of resources available. Then each control step is scheduled in turn. For each control step, a local ratio is calculated (for the current control step, the ratio of the number of available resources of each type over the number of required resources of each type), a global ratio is calculated (similar, but for all operations still unscheduled). The algorithm then schedules and binds the operation which keeps the most critical ratio (the smallest one) as high as possible, continuing until that control step is completed. 

Uses a set of small transformations, including multiplexor reduction, allocation of assignment operations, and data path partitioning, plus several translation steps, which perform the module binding. 

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