misched: fall-back to a target hook for instr bundles.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165606 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TargetSchedule.cpp b/lib/CodeGen/TargetSchedule.cpp
index edf6815..4e753c6 100644
--- a/lib/CodeGen/TargetSchedule.cpp
+++ b/lib/CodeGen/TargetSchedule.cpp
@@ -203,10 +203,11 @@
 }
 
 unsigned TargetSchedModel::computeInstrLatency(const MachineInstr *MI) const {
-  if (hasInstrItineraries()) {
-    // For the itinerary model, fall back to the old subtarget hook.
+  // For the itinerary model, fall back to the old subtarget hook.
+  // Allow subtargets to compute Bundle latencies outside the machine model.
+  if (hasInstrItineraries() || MI->isBundle())
     return TII->getInstrLatency(&InstrItins, MI);
-  }
+
   if (hasInstrSchedModel()) {
     unsigned Latency = 0;
     const MCSchedClassDesc *SCDesc = resolveSchedClass(MI);