Improve Devirtualization Precision

PrincetonUniversity / cpf

Collaborative Parallelization Framework (CPF)

MIT License

31 stars 4 forks source link

Improve Devirtualization Precision #5

Open vgene opened 4 years ago

vgene commented 4 years ago

Possible Technique

[ ] More aggressively marking "final" to functions due to whole program visible assumption
[ ] Combine existing techniques (from LLVM/NOELLE to CPF)
[x] Speculative devirtualization (using value pred and control spec)

Resources:

http://hubicka.blogspot.com/2014/02/devirtualization-in-c-part-4-analyzing.html

sapostolakis commented 4 years ago

I dont see much benefit for point 1. It is good for exploration but it does not solve the problem since it requires manual changes. Automating this part given whole program visibility would be hard so it should not be a priority. Point 2 is useful but the gains will be minimal. Step 3 will be needed regardless of the improvements in point 2.

vgene commented 3 years ago

A modified version pgo-icall-prom can promote all functions: A standalone pass to check existing behavior: https://github.com/vgene/check-indirect-call-pass