diff --git a/llvm/lib/CodeGen/MachineCopyPropagation.cpp b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
--- a/llvm/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
@@ -648,6 +648,10 @@
       continue;
     }
 
+    // Ignore DBG_VALUEs
+    if (MI->isDebugValue())
+        continue;
+
     // Clobber any earlyclobber regs first.
     for (const MachineOperand &MO : MI->operands())
       if (MO.isReg() && MO.isEarlyClobber()) {
@@ -846,6 +850,10 @@
       }
     }
 
+    // Ignore DBG_VALUEs
+    if (MI->isDebugValue())
+        continue;
+
     // Invalidate any earlyclobber regs first.
     for (const MachineOperand &MO : MI->operands())
       if (MO.isReg() && MO.isEarlyClobber()) {