HOL Code Generator Development Methodology.

摘要

On the basis of the analyses presented in this report, it appears that it is feasible to modify an existing HOL to provide low-cost retargeting, without severely degrading the object-time execution efficiency. Some specific recommendations include: (1) The compiler chosen must have an architecture such that there is both a well-defined intermediate language (IL) and a modular code generator (CG); an IL composed of triplets or quadruples is preferred; (2) The compiler chosen must have extensive capability to perform global optimization. It is suggested that existing capabilities be enhanced to include code straightening, dead variable analysis, and loop optimizations. The important area of register management should be performed in a parametric manner, so that retargeting can be accomplished by loading a table of machine parameters; (3) The code generator should output a character string consisting of assembly language for the target machine; assembly and linking shall be accomplished off-line by separate software; and (4) At least one extra level of IL should be considered.