Fix some latent bugs if the nodes are unschedulable. We'd gotten away

with this before since none of the register tracking or nightly tests
had unschedulable nodes.

This should probably be refixed with a special default Node that just
returns some "don't touch me" values.

Fixes PR9427


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127263 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 1 deletions

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index 20cbed78df..42d096e049 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -1785,7 +1785,7 @@ int RegReductionPQBase::RegPressureDiff(SUnit *SU, unsigned &LiveUses) const {
   }
   const SDNode *N = SU->getNode();
 
-  if (!N->isMachineOpcode() || !SU->NumSuccs)
+  if (!N || !N->isMachineOpcode() || !SU->NumSuccs)
     return PDiff;
 
   unsigned NumDefs = TII->get(N->getMachineOpcode()).getNumDefs();
@@ -1804,6 +1804,9 @@ void RegReductionPQBase::ScheduledNode(SUnit *SU) {
   if (!TracksRegPressure)
     return;
 
+  if (!SU->getNode())
+    return;
+  
   for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
        I != E; ++I) {
     if (I->isCtrl())
@@ -1870,6 +1873,8 @@ void RegReductionPQBase::UnscheduledNode(SUnit *SU) {
     return;
 
   const SDNode *N = SU->getNode();
+  if (!N) return;
+  
   if (!N->isMachineOpcode()) {
     if (N->getOpcode() != ISD::CopyToReg)
       return;
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 67005d7e63..b762af5ca9 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -446,6 +446,10 @@ void ScheduleDAGSDNodes::BuildSchedGraph(AliasAnalysis *AA) {
 
 // Initialize NumNodeDefs for the current Node's opcode.
 void ScheduleDAGSDNodes::RegDefIter::InitNodeNumDefs() {
+  // Check for phys reg copy.
+  if (!Node)
+    return;
+
   if (!Node->isMachineOpcode()) {
     if (Node->getOpcode() == ISD::CopyFromReg)
       NodeNumDefs = 1;