Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -8598,6 +8598,19 @@
   for (auto &Entry : SinkAfter) {
     VPRecipeBase *Sink = RecipeBuilder.getRecipe(Entry.first);
     VPRecipeBase *Target = RecipeBuilder.getRecipe(Entry.second);
+    // If the target is in a replication region, make sure to move Sink to the
+    // block after it, not into the replication region itself.
+    if (auto *Region =
+            dyn_cast_or_null<VPRegionBlock>(Target->getParent()->getParent())) {
+      if (Region->isReplicator()) {
+        assert(Region->getNumSuccessors() == 1 && "Expected SESE region!");
+        VPBasicBlock *NextBlock =
+            cast<VPBasicBlock>(Region->getSuccessors().front());
+        Sink->removeFromParent();
+        NextBlock->insert(Sink, NextBlock->begin());
+        continue;
+      }
+    }
     Sink->moveAfter(Target);
   }
 
Index: llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll
===================================================================
--- llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll
+++ llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll
@@ -645,3 +645,26 @@
 for.end:
   ret void
 }
+
+; CHECK-LABEL: sink_into_replication_region
+; CHECK: <4 x i32>
+define i32 @sink_into_replication_region() {
+bb:
+  br label %bb2
+
+  bb1:                                              ; preds = %bb2
+  %tmp = phi i32 [ %tmp6, %bb2 ]
+  ret i32 %tmp
+
+  bb2:                                              ; preds = %bb2, %bb
+  %tmp3 = phi i32 [ %tmp8, %bb2 ], [ undef, %bb ]
+  %tmp4 = phi i32 [ %tmp7, %bb2 ], [ undef, %bb ]
+  %tmp5 = phi i32 [ %tmp6, %bb2 ], [ undef, %bb ]
+  %tmp6 = add i32 %tmp5, %tmp4
+  %tmp7 = udiv i32 219220132, %tmp3
+  %tmp8 = add nsw i32 %tmp3, -1
+  %tmp9 = icmp slt i32 %tmp3, 2
+  br i1 %tmp9, label %bb1, label %bb2, !prof !2
+}
+
+!2 = !{!"branch_weights", i32 1, i32 1}