Compile-time program optimizations are similar to poetry: more are written
than are actually published in commercial compilers. Hard economic reality is
that many interesting optimizations have too narrow an audience to justify
their cost in a general-purpose compiler, and custom compilers are too
expensive to write. An alternative is to allow programmers to define their own
compile-time optimizations. This has already happened accidentally for C++,
albeit imperfectly, in the form of template metaprogramming. This paper
surveys the problems, the accidental success, and what directions future
research might take to circumvent current economic limitations of monolithic
compilers. |