[llvm] dd22680 - Revert "[NFCI][LoopDeletion] Do not call complex analysis for known non-zero BTC"

[Stefan Pintilie via llvm-commits]

Author: Stefan Pintilie
Date: 2021-05-28T12:21:21-05:00
New Revision: dd226803c220f02a5987f0ee9f9ac3ffe2b35c09

URL: https://github.com/llvm/llvm-project/commit/dd226803c220f02a5987f0ee9f9ac3ffe2b35c09
DIFF: https://github.com/llvm/llvm-project/commit/dd226803c220f02a5987f0ee9f9ac3ffe2b35c09.diff

LOG: Revert "[NFCI][LoopDeletion] Do not call complex analysis for known non-zero BTC"

This reverts commit 7d418dadf6b1e6fd9bcccf7c5b5e1db74992ee70.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LoopDeletion.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
index da9a767d6fea..acc2056c4a54 100644
--- a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
@@ -314,8 +314,6 @@ breakBackedgeIfNotTaken(Loop *L, DominatorTree &DT, ScalarEvolution &SE,
     return LoopDeletionResult::Unmodified;
 
   auto *BTC = SE.getBackedgeTakenCount(L);
-  if (!isa<SCEVCouldNotCompute>(BTC) && SE.isKnownNonZero(BTC))
-    return LoopDeletionResult::Unmodified;
   if (!BTC->isZero() && !canProveExitOnFirstIteration(L, DT, SE, LI))
     return LoopDeletionResult::Unmodified;