1 files changed, 7 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 6b46cb356c2..8e8af1b37b3 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -1952,6 +1952,13 @@ bool MachineInstr::addRegisterKilled(unsigned IncomingReg,
     MachineOperand &MO = getOperand(i);
     if (!MO.isReg() || !MO.isUse() || MO.isUndef())
       continue;
+
+    // DEBUG_VALUE nodes do not contribute to code generation and should
+    // always be ignored. Failure to do so may result in trying to modify
+    // KILL flags on DEBUG_VALUE nodes.
+    if (MO.isDebug())
+      continue;
+
     unsigned Reg = MO.getReg();
     if (!Reg)
       continue;