Hi all, I'm Erik Krisztián Varga, a 2nd year Electrical Engineering student, and I'd be interested in contributing to gcc as part of GSoC 2015. I'd like to work on adding an addressing mode selection pass to the RTL based on the ideas described in Eckstein et. al.'s paper on the subject [1]. The basic idea is to reduce the problem to a Partitioned Boolean Quadratic Programming (PBQP) problem and to find a close-to-optimal solution with a heuristic algorithm. It should be possible to model a lot of addressing modes with the cost matrix approach described in the paper, so this would be a generic way to do AMS for different architectures.
Quite a few things would have to be done to implement the algorithm, like finding the correct models for the various addressing instructions in the supported architectures, or implementing an efficient representation of the cost vectors and matrices, but I think it should be possible in the scope of a Summer to have at least a working prototype ready. Would someone be interested in mentoring this project for GSoC? Is there anything similar currently being worked on? I think Oleg Endo has started implementing such a pass a while ago (mentioned in PR56590). Best regards, Erik [1] http://sydney.edu.au/engineering/it/~scholz/publications/cgo03.pdf
