“…The PUMP architecture neither bounds the number of metadata bits nor the number of policies simultaneously supported; its microarchitectural optimizations (opgroups, tag compression, tag translation, and miss handler acceleration-see §4) achieve performance comparable to dedicated, hardware metadata propagation solutions ( §5). We believe the software-defined metadata policy model and its acceleration will be applicable to a large range of policies beyond those illustrated here, including sound information-flow control [7,8,32,56,62], fine-grained access control [67,71], integrity, synchronization [6,61], race detection [58,73], debugging, application-specific policies [70], and controlled generation and execution of dynamic code.…”