[CodeGen] Fix backward copy propagation with -g

[condy]

Summary

Co-authored-by: condy <[e-mail]>

[condy]

Sorry

llvm/lib/CodeGen/MachineCopyPropagation.cpp

if (MI->isCopy() && !TRI->regsOverlap(MI->getOperand(0).getReg(),
         Tracker.clobberRegister(Reg, *TRI);
       }
 
       Tracker.trackCopy(MI, *TRI);
 
       continue;
     }
 
+    // Ignore DBG_VALUEs and other meta infos
+    if (MI->isMetaInstruction())
+      continue;
+
     // Clobber any earlyclobber regs first.
     for (const MachineOperand &MO : MI->operands())
       if (MO.isReg() && MO.isEarlyClobber()) {
         MCRegister Reg = MO.getReg().asMCReg();
         // If we have a tied earlyclobber, that means it is also read by this
         // instruction, so we need to make sure we don't remove it as dead
         // later.
         if (MO.isTied())
if (MI->isCopy() && MI->getNumOperands() == 2 &&
       if (isBackwardPropagatableCopy(*MI, *MRI)) {
         Tracker.invalidateRegister(Src, *TRI);
         Tracker.invalidateRegister(Def, *TRI);
         Tracker.trackCopy(MI, *TRI);
         continue;
       }
     }
 
+    // Ignore DBG_VALUEs and other meta infos
+    if (MI->isMetaInstruction())
+      continue;
+
     // Invalidate any earlyclobber regs first.
     for (const MachineOperand &MO : MI->operands())
       if (MO.isReg() && MO.isEarlyClobber()) {
         MCRegister Reg = MO.getReg().asMCReg();
         if (!Reg)
           continue;
         Tracker.invalidateRegister(Reg, *TRI);
       }

llvm/test/CodeGen/X86/machine-cp-clobbers.mir

+# RUN: llc -mtriple=x86_64 -run-pass=machine-cp %s -o - | FileCheck %s
+
+---
+name: dont_clobber_register_in_dbg_value
+tracksRegLiveness: false
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: dont_clobber_register_in_dbg_value
+    ; CHECK: renamable $rbx = LEA64r $rax, 1, $noreg, 8, $noreg
+    ; CHECK: DBG_VALUE $rbp, $noreg
+    ; CHECK: DBG_VALUE $noreg, $noreg
+    renamable $rbx = LEA64r $rax, 1, $noreg, 8, $noreg
+    DBG_VALUE $rbp, $noreg
+    renamable $rbx = COPY killed renamable $rbp
+    DBG_VALUE $noreg, $noreg
+
+...