Waddle - Always-Canonical Intermediate Representation
Program transformations that are able to rely on the presence of canonical properties of the program undergoing optimization can be written to be more robust and efficient than an equivalent but generalized transformation that also handles non-canonical programs. If a canonical property is required but broken earlier in an earlier transformation, it must be rebuilt (often from scratch). This additional work can be a dominating factor in compilation time when many transformations are applied over large programs. This dissertation introduces a methodology for constructing program transformations so that the program remains in an always-canonical form as the program is mutated, making only local changes to restore broken properties.
Maintaining Canonical Form After Edge Deletion
Waddle is a research intermediate-form optimizer that strictly maintains a canonical form similar to the loop-simplify form used in LLVM. The properties of this canonical form simplify movement of instructions to the edges of loops and often localize the effect on variables to the loop in which they are defined. The guarantee of canonical form preservation allows program transformations to rely on the presence of certain program properties without a necessary sanity-check or recalculation pre-step and does not impose an order of transformations in which reconstruction passes must be inserted.
In this paper, we present a form-preserving edge deletion operation, in which a provably unreachable branch between two basic blocks is removed from the control flow graph. Additionally, we show a distinct application of the block ejection operation, a core procedure used for loop body reconstruction, as utilized in a function inlining transformation.
Charon: The Design of a Limiting Microservice
Charon is a service designed to increase the stability of a distributed system by preventing the overcommitment of limited resources during extreme load. The service monitors the access history of resources and is used as a central authority which either grants or denies requests for resource acquisition and use. This paper describes the architecture and feature set of Charon, as well as the rationale behind design decisions.
Arrows in Commercial Web Applications