[PATCH] D75362: [InstCombine] Process blocks in RPO

Sun Mar 1 07:09:10 PST 2020

nikic marked an inline comment as done.
nikic added a comment.

In D75362#1898366 <https://reviews.llvm.org/D75362#1898366>, @xbolva00 wrote:

> Did you observe any (positive) compile time changes?

I don't expect visible improvement from (just) this change, because it affects few cases (less than 1% of our InstCombine tests). My hope is that we can remove fixpoint iteration from InstCombine entirely in the future, once all the known issues are resolved. I'm still not sure if that's realistic, but I'm getting pretty close now...

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Comment at: test/Transforms/InstCombine/store.ll:2
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -instcombine -S | FileCheck %s
+; RUN: opt < %s -instcombine -instcombine-infinite-loop-threshold=2 -S | FileCheck %s

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xbolva00 wrote:
> since -infinite-loop-threshold now serves as a max treshold value, should we rename it?
> 
> -instcombine-iterations-threshold?
> 
> 
Yes, the "infinite loop" terminology doesn't make a lot of sense for this usage. We also have a `-instcombine-max-iterations` setting, so it's a bit tricky to distinguish these two limits (one just stops, the other reports a fatal error).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75362/new/

https://reviews.llvm.org/D75362