[llvm] b2b4d95 - [NFC][LoopFlatten][LoopInterchange] Do not explicitly forget subloops

[Joshua Cao via llvm-commits]

Author: Joshua Cao
Date: 2023-01-12T08:08:11-08:00
New Revision: b2b4d95827b7db1a1cd92e2789f306f499b74b40

URL: https://github.com/llvm/llvm-project/commit/b2b4d95827b7db1a1cd92e2789f306f499b74b40
DIFF: https://github.com/llvm/llvm-project/commit/b2b4d95827b7db1a1cd92e2789f306f499b74b40.diff

LOG: [NFC][LoopFlatten][LoopInterchange] Do not explicitly forget subloops

We don't need to explicitly forget subloops because forgetting parent
loops will automatically forget their subloops

Differential Revision: https://reviews.llvm.org/D141029

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LoopFlatten.cpp
    llvm/lib/Transforms/Scalar/LoopInterchange.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Scalar/LoopFlatten.cpp b/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
index 5a43d373207cf..7d9ce8d35e0b4 100644
--- a/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
@@ -786,9 +786,8 @@ static bool DoFlattenLoopPair(FlattenInfo &FI, DominatorTree *DT, LoopInfo *LI,
   }
 
   // Tell LoopInfo, SCEV and the pass manager that the inner loop has been
-  // deleted, and any information that have about the outer loop invalidated.
+  // deleted, and invalidate any outer loop information.
   SE->forgetLoop(FI.OuterLoop);
-  SE->forgetLoop(FI.InnerLoop);
   SE->forgetBlockAndLoopDispositions();
   if (U)
     U->markLoopAsDeleted(*FI.InnerLoop, FI.InnerLoop->getName());

diff  --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
index a4ea93084c06c..84de61490f763 100644
--- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -1240,7 +1240,6 @@ void LoopInterchangeTransform::restructureLoops(
 
   // Tell SE that we move the loops around.
   SE->forgetLoop(NewOuter);
-  SE->forgetLoop(NewInner);
 }
 
 bool LoopInterchangeTransform::transform() {