diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
 b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -418,17 +418,21 @@
       // ProcessBlock doesn't thread BBs with unconditional TIs. However, if BB
       // is "almost empty", we attempt to merge BB with its sole successor.
       auto *BI = dyn_cast<BranchInst>(BB.getTerminator());
-      if (BI && BI->isUnconditional() &&
-          // The terminator must be the only non-phi instruction in BB.
-          BB.getFirstNonPHIOrDbg()->isTerminator() &&
-          // Don't alter Loop headers and latches to ensure another pass can
-          // detect and transform nested loops later.
-          !LoopHeaders.count(&BB) && !LoopHeaders.count(BI->getSuccessor(0)) &&
-          TryToSimplifyUncondBranchFromEmptyBlock(&BB, DTU)) {
-        // BB is valid for cleanup here because we passed in DTU. F remains
-        // BB's parent until a DTU->getDomTree() event.
-        LVI->eraseBlock(&BB);
-        Changed = true;
+      if (BI && BI->isUnconditional()) {
+        BasicBlock *Succ = BI->getSuccessor(0);
+        if (
+            // The terminator must be the only non-phi instruction in BB.
+            BB.getFirstNonPHIOrDbg()->isTerminator() &&
+            // Don't alter Loop headers and latches to ensure another pass can
+            // detect and transform nested loops later.
+            !LoopHeaders.count(&BB) && !LoopHeaders.count(Succ) &&
+            TryToSimplifyUncondBranchFromEmptyBlock(&BB, DTU)) {
+          // BB is valid for cleanup here because we passed in DTU. F remains
+          // BB's parent until a DTU->getDomTree() event.
+          RemoveRedundantDbgInstrs(Succ);
+          LVI->eraseBlock(&BB);
+          Changed = true;
+        }
       }
     }
     EverChanged |= Changed;