A: A sad truth is that most decompilers out there are crippled. Many aren't able to decompile trivial constructs, others can't decompile more advanced, those which seemingly can deal with them, are crippled by supporting only the boring architectures and OSes. And almost every written in such a way that tweaking it or adding a new architecture is complicated. A decompiler is a tool for reverse engineering, but ironically, if you want to use a typical decompiler productively or make it suit your needs, first you will need to reverse-engineer the decompiler itself, and that can easily take months (or years). The central part of a decompiler (and any program transformation framework) is Intermediate Representation (IR). A decompiler should work on IR, and should take it as an input, and conversion of a particular architecture's assembler to this IR should be well decoupled from a decompiler, or otherwise it takes extraordinary effort to add support for another architecture (which in turn limits userbase of a decompiler).