A quantitative comparison of two retargetable compilation approaches

In the design of an embedded processor, the compiler design is tightly coupled with the underlying processor architecture, and thus it is crucial to rapidly retarget a compiler along with the change in the architecture in order to expedite the processor design. However, among many compiler writers, there is a controversial issue that has long been argued - whether a compiler can be easily retargetable while it performs sophisticated machine-specific optimizations for a new architecture configuration. We examine this issue by finding some possible cases where optimizations may be impeded on a pathway to building a retargetable compiler. For this, we developed two types of compilation frameworks called user-retargetable and developer-retargetable, and compared their performance.