Index: llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -579,24 +579,33 @@
 
   // The new block unconditionally branches to the old block.
   BranchInst *BI = BranchInst::Create(BB, NewBB);
+  bool IsBBHeader = LI && LI->isLoopHeader(BB);
+  Loop *BBLoop = LI ? LI->getLoopFor(BB) : nullptr;
   // Splitting the predecessors of a loop header creates a preheader block.
-  if (LI && LI->isLoopHeader(BB))
+  if (IsBBHeader)
     // Using the loop start line number prevents debuggers stepping into the
     // loop body for this instruction.
-    BI->setDebugLoc(LI->getLoopFor(BB)->getStartLoc());
+    BI->setDebugLoc(BBLoop->getStartLoc());
   else
     BI->setDebugLoc(BB->getFirstNonPHIOrDbg()->getDebugLoc());
 
   // Move the edges from Preds to point to NewBB instead of BB.
-  for (unsigned i = 0, e = Preds.size(); i != e; ++i) {
+  for (BasicBlock *Pred : Preds) {
+    Instruction *PI = Pred->getTerminator();
     // This is slightly more strict than necessary; the minimum requirement
     // is that there be no more than one indirectbr branching to BB. And
     // all BlockAddress uses would need to be updated.
-    assert(!isa<IndirectBrInst>(Preds[i]->getTerminator()) &&
+    assert(!isa<IndirectBrInst>(PI) &&
            "Cannot split an edge from an IndirectBrInst");
-    assert(!isa<CallBrInst>(Preds[i]->getTerminator()) &&
-           "Cannot split an edge from a CallBrInst");
-    Preds[i]->getTerminator()->replaceUsesOfWith(BB, NewBB);
+    assert(!isa<CallBrInst>(PI) && "Cannot split an edge from a CallBrInst");
+    if (IsBBHeader && BBLoop->contains(Pred) && BBLoop->isLoopLatch(Pred)) {
+      // Update loop metadata if it exists.
+      if (MDNode *LoopMD = PI->getMetadata(LLVMContext::MD_loop)) {
+        BI->setMetadata(LLVMContext::MD_loop, LoopMD);
+        PI->setMetadata(LLVMContext::MD_loop, nullptr);
+      }
+    }
+    PI->replaceUsesOfWith(BB, NewBB);
   }
 
   // Insert a new PHI node into NewBB for every PHI node in BB and that new PHI
Index: llvm/test/Transforms/LoopSimplify/loop_metadata.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopSimplify/loop_metadata.ll
@@ -0,0 +1,36 @@
+; RUN: opt -S -loop-simplify < %s | FileCheck %s
+
+; CHECK: for.cond.loopexit:
+; CHECK: br label %for.cond, !llvm.loop !0
+; CHECK: br i1 %cmp1, label %for.body1, label %for.cond.loopexit
+
+define void @foo() {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.cond1, %entry
+  %j = phi i32 [ 0, %entry ], [ %add, %for.cond1 ]
+  %cmp = icmp ult i32 %j, 8
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %dummy1 = add i32 1, 1
+  %add = add nuw nsw i32 %j, 1
+  br label %for.cond1
+
+for.cond1:                                      ; preds = %for.body1, %for.body
+  %i.0 = phi i32 [ 1, %for.body ], [ %inc, %for.body1 ]
+  %cmp1 = icmp ult i32 %i.0, 8
+  br i1 %cmp1, label %for.body1, label %for.cond, !llvm.loop !0
+
+for.body1:                                      ; preds = %for.cond1
+  %dummy2 = add i32 1, 1
+  %inc = add nuw nsw i32 %i.0, 1
+  br label %for.cond1
+
+for.end:                                       ; preds = %for.cond
+  ret void
+}
+
+!0 = distinct !{!0, !1}
+!1 = !{!"llvm.loop.unroll.full"}