misched: Infrastructure for weak DAG edges.

This adds support for weak DAG edges to the general scheduling
infrastructure in preparation for MachineScheduler support for
heuristics based on weak edges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167738 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 3 insertions, 1 deletions

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index c55456902c..dc8f0ee4a2 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -156,7 +156,7 @@ public:
                     CodeGenOpt::Level OptLevel)
     : ScheduleDAGSDNodes(mf),
       NeedLatency(needlatency), AvailableQueue(availqueue), CurCycle(0),
-      Topo(SUnits) {
+      Topo(SUnits, NULL) {
 
     const TargetMachine &tm = mf.getTarget();
     if (DisableSchedCycles || !NeedLatency)
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGVLIW.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGVLIW.cpp
index 30f03ac737..f8ca7b1d40 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGVLIW.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGVLIW.cpp
@@ -123,6 +123,8 @@ void ScheduleDAGVLIW::releaseSucc(SUnit *SU, const SDep &D) {
     llvm_unreachable(0);
   }
 #endif
+  assert(!D.isWeak() && "unexpected artificial DAG edge");
+
   --SuccSU->NumPredsLeft;
 
   SuccSU->setDepthToAtLeast(SU->getDepth() + D.getLatency());