[llvm] [ReachingDefAnalysis] Extend the analysis to stack objects. (PR #118097)

[Michael Maitland via llvm-commits]

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@@ -525,14 +610,21 @@ MachineInstr *ReachingDefAnalysis::getLocalLiveOutMIDef(MachineBasicBlock *MBB,
                                                         MCRegister Reg) const {
   LiveRegUnits LiveRegs(*TRI);
   LiveRegs.addLiveOuts(*MBB);
-  if (LiveRegs.available(Reg))
+  if (Register::isPhysicalRegister(Reg) && LiveRegs.available(Reg))
     return nullptr;
 
   auto Last = MBB->getLastNonDebugInstr();
   if (Last == MBB->end())
     return nullptr;
 
   int Def = getReachingDef(&*Last, Reg);
+
+  if (Register::isStackSlot(Reg)) {
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michaelmaitland wrote:

This code can be at the very start of this function to avoid any extra work?

https://github.com/llvm/llvm-project/pull/118097