@TechReport{shao98:tcc-tr,
  author =	 {Bratin Saha and Zhong Shao},
  title =	 {Optimal Type Lifting},
  institution =	 {Yale University},
  year =	 1998,
  number =	 {YALEU/DCS/TR-1159},
  month =	 {August},
  abstract =	 {Modern compilers for ML-like polymorphic languages
                  have used explicit run-time type passing to support
                  advanced optimizations such as intensional type
                  analysis, dynamic type dispatch, and tagless garbage
                  collection. Unfortunately, maintaining type
                  information at run time can incur large overhead to
                  the time and space usage of a program. In this
                  paper, we present an optimal type-lifting algorithm
                  that lifts all type applications in a program to the
                  \emph{top} level. Our algorithm eliminates all
                  run-time type constructions within ane core-language
                  functions. In fact, it guarantees that the number of
                  types built at run time is strictly a compile-time
                  constant. We present our algorithm as a
                  type-preserving source-to-source transformation and
                  show how to extend it to handle the entire SML'97
                  with higher-order modules.}
}