From dd226803c220f02a5987f0ee9f9ac3ffe2b35c09 Mon Sep 17 00:00:00 2001
From: Stefan Pintilie <stefanp@ca.ibm.com>
Date: Fri, 28 May 2021 11:17:46 -0500
Subject: [PATCH] Revert "[NFCI][LoopDeletion] Do not call complex analysis for
 known non-zero BTC"

This reverts commit 7d418dadf6b1e6fd9bcccf7c5b5e1db74992ee70.
---
 llvm/lib/Transforms/Scalar/LoopDeletion.cpp | 2 --
 1 file changed, 2 deletions(-)

diff --git a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
index da9a767..acc2056 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;
 
-- 
2.7.4