[PATCH] D109958: [LoopFlatten] Enable it by default

[Arthur Eubanks via Phabricator via llvm-commits]

aeubanks added inline comments.


================
Comment at: llvm/test/Other/new-pm-defaults.ll:168
+; CHECK-O-NEXT: Running pass: LoopSimplifyPass
+; CHECK-O-NEXT: Running pass: LCSSAPass
 ; CHECK-O-NEXT: Running pass: LoopIdiomRecognizePass
----------------
nikic wrote:
> As a drive-by comment for @asbirlea and @aeubanks, it looks like there's an opportunity here to not rerun LoopSimplify/LCSSA if we run multiple Loop/LoopNest pass managers back to back?
we need to fix where we add `LoopFlattenPass` in PassBuilderPipelines.cpp

instead of

```
  if (EnableLoopFlatten)
    FPM.addPass(createFunctionToLoopPassAdaptor(LoopFlattenPass()));
```
we should move it earlier to
```
  if (EnableLoopFlatten)
    LPM2.addPass(LoopFlattenPass());
```


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109958/new/

https://reviews.llvm.org/D109958