Method of synchronizing parallel processors employing channels and compiling method minimizing cross-processor data dependencies

摘要

A method of synchronizing the parallel processors of a multiple instruction stream multiprocessor employs a limited number of register channels, which may be re-used, for enforcing cross-stream data or event dependencies by passing data or event notifications in a synchronizing fashion. Cross-stream dependencies which by virtue of identified "synchronization redundancey" do not require enforcement by register channels are passed by writing to and reading from ordinary shared memory. A compiling method schedules the instructions into parallel instruction streams by reference to a directed acyclic graph (DAG), in a manner to minimize the production of cross-stream dependencies. The scheduling is determined beginning from the highest nodes in the DAG and proceeding to nodes in order of descending node height in a manner tending and tends to assign whole sub-graphs of the DAG to different processors.