1 files changed, 10 insertions, 5 deletions
diff --git a/llvm/lib/CodeGen/MachineCSE.cpp b/llvm/lib/CodeGen/MachineCSE.cpp
index 9561a06ce8df..09531276bc10 100644
--- a/llvm/lib/CodeGen/MachineCSE.cpp
+++ b/llvm/lib/CodeGen/MachineCSE.cpp
@@ -747,9 +747,8 @@ bool MachineCSE::PerformCSE(MachineDomTreeNode *Node) {
   do {
     Node = WorkList.pop_back_val();
     Scopes.push_back(Node);
-    const std::vector<MachineDomTreeNode*> &Children = Node->getChildren();
-    OpenChildren[Node] = Children.size();
-    for (MachineDomTreeNode *Child : Children)
+    OpenChildren[Node] = Node->getNumChildren();
+    for (MachineDomTreeNode *Child : Node->children())
       WorkList.push_back(Child);
   } while (!WorkList.empty());
 
@@ -831,6 +830,13 @@ bool MachineCSE::ProcessBlockPRE(MachineDominatorTree *DT,
           continue;
         MachineInstr &NewMI =
             TII->duplicate(*CMBB, CMBB->getFirstTerminator(), *MI);
+
+        // When hoisting, make sure we don't carry the debug location of
+        // the original instruction, as that's not correct and can cause
+        // unexpected jumps when debugging optimized code.
+        auto EmptyDL = DebugLoc();
+        NewMI.setDebugLoc(EmptyDL);
+
         NewMI.getOperand(0).setReg(NewReg);
 
         PREMap[MI] = CMBB;
@@ -855,8 +861,7 @@ bool MachineCSE::PerformSimplePRE(MachineDominatorTree *DT) {
   BBs.push_back(DT->getRootNode());
   do {
     auto Node = BBs.pop_back_val();
-    const std::vector<MachineDomTreeNode *> &Children = Node->getChildren();
-    for (MachineDomTreeNode *Child : Children)
+    for (MachineDomTreeNode *Child : Node->children())
       BBs.push_back(Child);
 
     MachineBasicBlock *MBB = Node->getBlock();