Optimizations performed at link time or directly applied to final program executables have received increased attention in recent years. Such low-level optimizations can benefit greatly from pointer alias information. However, as almost all existing alias analyses are formulated in terms of source language constructs, they turn out to be of limited utility at the machine code level. This paper describes two different approaches to highquality, low-cost, speculative may-alias analysis, to be applied in the context of link-time or executable code optimiz