diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1090,6 +1090,47 @@
     }
   }
 
+  // If the unconditional branch we replaced contains llvm.loop metadata
+  // and any of its predecessor is also a loop latch, bail out directly.
+  //
+  // Two alternative options that won't work well:
+  // 1. Partially forwards 'BB->pred' to 'BB->succ', only for predecessors of BB
+  // that are not loop latches.
+  //    In this case, 'BB' might be partially duplicated (e.g., the PHI
+  //    instructions) into 'BB->succ' for non-loop-latch pred, and meanwhile
+  //    still preserved for loop-latch pred. 'BB->succ' has more predecesors.
+  // 2. Proceed with deleting 'BB' when loop metadata of BB and Pred could be
+  // concatenated correctly (e.g. loop properties doesn't conflict, and the
+  // concatenation won't changing loop transformation result due to pass
+  // ordering, etc).
+  //    1) Firstly, multiple transformations in the same metadata are ambigious
+  //    -> the transformation result depend on execution order of different loop
+  //    passes. Say 'BB' and 'BB->pred' are outer and inner loop respectively,
+  //    concatenating them correctly for different scenarios is tricky. 2) In a
+  //    subset of cases when concat is correct,
+  //       a) if the inner-most loop of 'BB' and inner-most loop of Pred are the
+  //       same loop, LoopSimplify (scheduled before each LoopPass by pass
+  //       managers) will ensure there is only exactly one loop latch. So it's
+  //       better to let LoopSimplify simplify the CFG. b) If 'BB' is from an
+  //       outer loop and 'Pred' is from an inner loop, then 'BB' is an exit
+  //       block of the inner-loop with predecessors that are out of the
+  //       inner-loop. As a result, LoopSimplify will create dedicated exits for
+  //       the inner loop, which has the same effect of adding 'BB' back. By
+  //       then it's ambiguious how to undo the concatenation of loop metadata.
+  //
+  // In practice, the SimplifyCFG pass could run many times in an optimizer
+  // pipeline. When SimplifyCFG run after all loops passes complete, loops might
+  // have been simplified away (e.g. completely unrolled). In these cases, this
+  // function could still kick in and simplify trival 'BB' away.
+  if (Instruction *TI = BB->getTerminator())
+    if (MDNode *LoopMD = TI->getMetadata(LLVMContext::MD_loop)) {
+      for (BasicBlock *Pred : predecessors(BB)) {
+        if (Instruction *PredTI = Pred->getTerminator())
+          if (MDNode *PredLoopMD = PredTI->getMetadata(LLVMContext::MD_loop))
+            return false;
+      }
+    }
+
   LLVM_DEBUG(dbgs() << "Killing Trivial BB: \n" << *BB);
 
   SmallVector<DominatorTree::UpdateType, 32> Updates;
diff --git a/llvm/test/Transforms/SimplifyCFG/preserve-llvm-loop-metadata.ll b/llvm/test/Transforms/SimplifyCFG/preserve-llvm-loop-metadata.ll
--- a/llvm/test/Transforms/SimplifyCFG/preserve-llvm-loop-metadata.ll
+++ b/llvm/test/Transforms/SimplifyCFG/preserve-llvm-loop-metadata.ll
@@ -1,5 +1,5 @@
-; RUN: opt -opaque-pointers -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -keep-loops=false -S < %s | FileCheck %s
-; RUN: opt -opaque-pointers -passes='simplifycfg<no-keep-loops>' -S < %s | FileCheck %s
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -keep-loops=false -S < %s | FileCheck %s
+; RUN: opt -passes='simplifycfg<no-keep-loops>' -S < %s | FileCheck %s
 
 define void @test1(i32 %n) #0 {
 entry:
@@ -71,7 +71,7 @@
 ;    }
 ;    return sum;
 ; }
-define i32 @test2(i32 %a, i32 %b, i32 %step, i32 %remainder, ptr %input) {
+define i32 @test2(i32 %a, i32 %b, i32 %step, i32 %remainder, i32* %input) {
 entry:
   br label %while.cond
 
@@ -93,8 +93,8 @@
   %k.07 = phi i32 [ 0, %while.body ], [ %inc, %for.body ]
   %add2 = add nsw i32 %k.07, %add
   %idxprom = sext i32 %add2 to i64
-  %arrayidx = getelementptr inbounds i32, ptr %input, i64 %idxprom
-  %0 = load i32, ptr %arrayidx, align 4
+  %arrayidx = getelementptr inbounds i32, i32* %input, i64 %idxprom
+  %0 = load i32, i32* %arrayidx, align 4
   %1 = tail call i32 asm sideeffect "add ${0:w}, ${1:w}\0A", "=r,r,~{cc}"(i32 %0)
   %inc = add nuw nsw i32 %k.07, 1
   %cmp1 = icmp ult i32 %inc, 5
@@ -113,4 +113,5 @@
 !5 = !{!"llvm.loop.unroll.enable"}
 ; CHECK: !0 = distinct !{!0, !1}
 ; CHECK: !1 = !{!"llvm.loop.distribute.enable", i1 true}
-; CHECK-NOT: !{!"llvm.loop.unroll.enable"}
+; CHECK: !4 = distinct !{!4, !3, !5}
+; CHECK: !5 = !{!"llvm.loop.unroll.enable"}