A procedure is described which permits applications problems coded in a higher level language to be compiled to microcode for horizontally microprogrammed processors. An experimental language has been designed which is suitable for expressing computationally oriented problems for such processors in a distributed processing environment. Source programs are compiled first to a machine independent intermediate language and then to a machine dependence form consisting of elementary microoperations, with optimizations performed during each step. The microoperations are then compacted into executable microinstructions for a specific target machine. The procedure has been implemented for experimental purposes and used to compile several different types of applications programs. The experimental results are presented with an interpretation and analysis, along with recommendations for future study.

In automatically generating microcode starting from a highlevel source language, a significant issue is the description of the target microengine architecture. The techniques and methodologies used to accomplish this address the practical issues of: 1) a detailed description of all microprogram controJled haudware elements of the microengine, the microinstruction, the rules for valid use of all microprogrammed features, and the behavior of microprogrammed operations; and 2) the use of this description to interpret and decode higher level source intermediate languages to form microoperations and ultimately microinstructions. This work is a step in conceptually defining the techniques and methodologies for microarchitecture descriptions to accomplish the above. Its objective is to identify the techniques that appear to have the most promise for use in interjecting the target microarchitecture characteristics into the high-level language-to-microcode compilation process.