Change these schedulers to not emit no-ops. It turns out that

the RR scheduler actually does look at latency values, but it
doesn't use a hazard recognizer so it has no way to know when
a no-op is needed, as opposed to just stalling and incrementing
the cycle count.

llvm-svn: 59759

llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp

@@ -577,9 +577,7 @@ void ScheduleDAGFast::ListScheduleBottomUp() {
     }
     NotReady.clear();
 
-    if (!CurSU)
-      Sequence.push_back(0);
-    else
+    if (CurSU)
       ScheduleNodeBottomUp(CurSU, CurCycle);
     ++CurCycle;
   }

llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp

@@ -1052,9 +1052,7 @@ void ScheduleDAGRRList::ListScheduleBottomUp() {
     }
     NotReady.clear();
 
-    if (!CurSU)
-      Sequence.push_back(0);
-    else
+    if (CurSU)
       ScheduleNodeBottomUp(CurSU, CurCycle);
     ++CurCycle;
   }
@@ -1152,9 +1150,7 @@ void ScheduleDAGRRList::ListScheduleTopDown() {
     AvailableQueue->push_all(NotReady);
     NotReady.clear();
 
-    if (!CurSU)
-      Sequence.push_back(0);
-    else
+    if (CurSU)
       ScheduleNodeTopDown(CurSU, CurCycle);
     ++CurCycle;
   }