diff --git a/lib/CodeGen/MachineScheduler.cpp b/lib/CodeGen/MachineScheduler.cpp
index f79b39140c0..ef916174267 100644
--- a/lib/CodeGen/MachineScheduler.cpp
+++ b/lib/CodeGen/MachineScheduler.cpp
@@ -2492,7 +2492,10 @@ void ConvergingScheduler::tryCandidate(SchedCandidate &Cand,
     return;
 
   // For loops that are acyclic path limited, aggressively schedule for latency.
-  if (Rem.IsAcyclicLatencyLimited && tryLatency(TryCand, Cand, Zone))
+  // This can result in very long dependence chains scheduled in sequence, so
+  // once every cycle (when CurrMOps == 0), switch to normal heuristics.
+  if (Rem.IsAcyclicLatencyLimited && !Zone.CurrMOps
+      && tryLatency(TryCand, Cand, Zone))
     return;
 
   // Keep clustered nodes together to encourage downstream peephole