[llvm] [FuncSpec] Improve handling of Comparison Instructions (PR #114073)

[Alexandros Lamprineas via llvm-commits]

labrinea wrote:

Hey @hazzlim, the patch looks good.

Regarding teaching the InstConstVisitor about constant ranges I agree with you that it is probably not worth it. It then becomes a full blown lattice value solver like the SCCPSolver. The point is to keep it minimal for estimation purposes only, not full analysis.

> For example it improves the estimation of the CodeSize bonus for a specialization of the function digits_2 from the SPEC2k17 benchmark exchange2, increasing this from 23% to 71%

Cool! Does that mean we can boost the thresholds a bit?


https://github.com/llvm/llvm-project/pull/114073