. Compilers typically treat source-level and instruction-level issues as independent phases of compilation so that much of the information that might be available to source-level systems of transformations about the semantics of the high-level language and its implementation, as well as the algorithm in some cases, is generally "lost in the translation", making it unavailable to instruction-level systems of transformations. While this separation of concerns reduces the complexity of the compiler and facilitates porting the compiler to different source/target combinations, it also forces the costly recomputation at the instruction-level of much of the information that was already available to the higher level, and in many cases introduces spurious dependencies that can not be eliminated by instruction-level analysis alone. In this paper we present a simple mechanism for retaining algorithm and source language semantics information for use in instruction-level disambiguation, while retai...