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

[Craig Topper via llvm-commits]

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@@ -269,6 +341,19 @@ int ReachingDefAnalysis::getReachingDef(MachineInstr *MI,
   assert(MBBNumber < MBBReachingDefs.numBlockIDs() &&
          "Unexpected basic block number.");
   int LatestDef = ReachingDefDefaultVal;
+
+  if (Register::isStackSlot(Reg)) {
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topperc wrote:

A `MCRegister` should not be storing stack slots. If it needs to store stack slots, it should be `Register`.

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