When the scheduler unfold a load folding instruction it move some of the predecessors to the unfolded load. It decides what gets moved to the load by checking whether the new load is using the predecessor as an operand. The check neglects the cases whether the predecessor is a flagged scheduling unit.

rdar://7604000

llvm-svn: 95339

1 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index dea59937198..72a07dcb04c 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -345,6 +345,15 @@ void ScheduleDAGRRList::BacktrackBottomUp(SUnit *SU, unsigned BtCycle,
   ++NumBacktracks;
 }
 
+static bool isOperandOf(const SUnit *SU, SDNode *N) {
+  for (const SDNode *SUNode = SU->getNode(); SUNode;
+       SUNode = SUNode->getFlaggedNode()) {
+    if (SUNode->isOperandOf(N))
+      return true;
+  }
+  return false;
+}
+
 /// CopyAndMoveSuccessors - Clone the specified node and move its scheduled
 /// successors to the newly created node.
 SUnit *ScheduleDAGRRList::CopyAndMoveSuccessors(SUnit *SU) {
@@ -427,8 +436,7 @@ SUnit *ScheduleDAGRRList::CopyAndMoveSuccessors(SUnit *SU) {
          I != E; ++I) {
       if (I->isCtrl())
         ChainPreds.push_back(*I);
-      else if (I->getSUnit()->getNode() &&
-               I->getSUnit()->getNode()->isOperandOf(LoadNode))
+      else if (isOperandOf(I->getSUnit(), LoadNode))
         LoadPreds.push_back(*I);
       else
         NodePreds.push_back(*I);