Issues of the design of a low level microprogramming language for global microcode compaction

Microcode compaction, or packing, is the process of assigning microoperations to microwords so that the minimum number of microwords and execution time is used by the microprogram. The techniques for global microcode compaction have been described elsewhere (see below). This paper describes a proposal for an intermediate level language approach to compilation which allows machine independent global compaction. We will call the program which does this compaction the packer. This work comes from the development of the V-Compiler, a retargetable microprogram generation system1. The goal is to be able to produce very high quality microcode, while allowing code manipulations to be described and performed in an orderly manner.