diff --git a/mlir/lib/Transforms/Mem2Reg.cpp b/mlir/lib/Transforms/Mem2Reg.cpp
index 65de25dd2f326..62246a87b291a 100644
--- a/mlir/lib/Transforms/Mem2Reg.cpp
+++ b/mlir/lib/Transforms/Mem2Reg.cpp
@@ -96,6 +96,9 @@ using namespace mlir;
 
 namespace {
 
+using BlockingUsesMap =
+    llvm::MapVector<Operation *, SmallPtrSet<OpOperand *, 4>>;
+
 /// Information computed during promotion analysis used to perform actual
 /// promotion.
 struct MemorySlotPromotionInfo {
@@ -106,7 +109,7 @@ struct MemorySlotPromotionInfo {
   /// its uses, it is because the defining ops of the blocking uses requested
   /// it. The defining ops therefore must also have blocking uses or be the
   /// starting point of the bloccking uses.
-  DenseMap<Operation *, SmallPtrSet<OpOperand *, 4>> userToBlockingUses;
+  BlockingUsesMap userToBlockingUses;
 };
 
 /// Computes information for basic slot promotion. This will check that direct
@@ -129,8 +132,7 @@ class MemorySlotPromotionAnalyzer {
   /// uses (typically, removing its users because it will delete itself to
   /// resolve its own blocking uses). This will fail if one of the transitive
   /// users cannot remove a requested use, and should prevent promotion.
-  LogicalResult computeBlockingUses(
-      DenseMap<Operation *, SmallPtrSet<OpOperand *, 4>> &userToBlockingUses);
+  LogicalResult computeBlockingUses(BlockingUsesMap &userToBlockingUses);
 
   /// Computes in which blocks the value stored in the slot is actually used,
   /// meaning blocks leading to a load. This method uses `definingBlocks`, the
@@ -233,7 +235,7 @@ Value MemorySlotPromoter::getLazyDefaultValue() {
 }
 
 LogicalResult MemorySlotPromotionAnalyzer::computeBlockingUses(
-    DenseMap<Operation *, SmallPtrSet<OpOperand *, 4>> &userToBlockingUses) {
+    BlockingUsesMap &userToBlockingUses) {
   // The promotion of an operation may require the promotion of further
   // operations (typically, removing operations that use an operation that must
   // delete itself). We thus need to start from the use of the slot pointer and
@@ -243,7 +245,7 @@ LogicalResult MemorySlotPromotionAnalyzer::computeBlockingUses(
   // use it.
   for (OpOperand &use : slot.ptr.getUses()) {
     SmallPtrSet<OpOperand *, 4> &blockingUses =
-        userToBlockingUses.getOrInsertDefault(use.getOwner());
+        userToBlockingUses[use.getOwner()];
     blockingUses.insert(&use);
   }
 
@@ -281,7 +283,7 @@ LogicalResult MemorySlotPromotionAnalyzer::computeBlockingUses(
       assert(llvm::is_contained(user->getResults(), blockingUse->get()));
 
       SmallPtrSetImpl<OpOperand *> &newUserBlockingUseSet =
-          userToBlockingUses.getOrInsertDefault(blockingUse->getOwner());
+          userToBlockingUses[blockingUse->getOwner()];
       newUserBlockingUseSet.insert(blockingUse);
     }
   }
@@ -516,14 +518,16 @@ void MemorySlotPromoter::computeReachingDefInRegion(Region *region,
 }
 
 void MemorySlotPromoter::removeBlockingUses() {
-  llvm::SetVector<Operation *> usersToRemoveUses;
-  for (auto &user : llvm::make_first_range(info.userToBlockingUses))
-    usersToRemoveUses.insert(user);
-  SetVector<Operation *> sortedUsersToRemoveUses =
-      mlir::topologicalSort(usersToRemoveUses);
+  llvm::SmallVector<Operation *> usersToRemoveUses(
+      llvm::make_first_range(info.userToBlockingUses));
+  // The uses need to be traversed in *reverse dominance* order to ensure that
+  // transitive replacements are performed correctly.
+  llvm::sort(usersToRemoveUses, [&](Operation *lhs, Operation *rhs) {
+    return dominance.properlyDominates(rhs, lhs);
+  });
 
   llvm::SmallVector<Operation *> toErase;
-  for (Operation *toPromote : llvm::reverse(sortedUsersToRemoveUses)) {
+  for (Operation *toPromote : usersToRemoveUses) {
     if (auto toPromoteMemOp = dyn_cast<PromotableMemOpInterface>(toPromote)) {
       Value reachingDef = reachingDefs.lookup(toPromoteMemOp);
       // If no reaching definition is known, this use is outside the reach of
diff --git a/mlir/test/Dialect/LLVMIR/mem2reg.mlir b/mlir/test/Dialect/LLVMIR/mem2reg.mlir
index 30ba459d07a49..32e3fed7e5485 100644
--- a/mlir/test/Dialect/LLVMIR/mem2reg.mlir
+++ b/mlir/test/Dialect/LLVMIR/mem2reg.mlir
@@ -683,3 +683,16 @@ llvm.func @no_inner_alloca_promotion(%arg: i64) -> i64 {
   // CHECK: llvm.return %[[RES]] : i64
   llvm.return %2 : i64
 }
+
+// -----
+
+// CHECK-LABEL: @transitive_reaching_def
+llvm.func @transitive_reaching_def() -> !llvm.ptr {
+  %0 = llvm.mlir.constant(1 : i32) : i32
+  // CHECK-NOT: alloca
+  %1 = llvm.alloca %0 x !llvm.ptr {alignment = 8 : i64} : (i32) -> !llvm.ptr
+  %2 = llvm.load %1 {alignment = 8 : i64} : !llvm.ptr -> !llvm.ptr
+  llvm.store %2, %1 {alignment = 8 : i64} : !llvm.ptr, !llvm.ptr
+  %3 = llvm.load %1 {alignment = 8 : i64} : !llvm.ptr -> !llvm.ptr
+  llvm.return %3 : !llvm.ptr
+}