[llvm] [CodeGen][Spill2Reg] Initial patch (PR #118832)

[Simon Pilgrim via llvm-commits]

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@@ -294,6 +294,11 @@ class TargetInstrInfo : public MCInstrInfo {
     return isLoadFromStackSlot(MI, FrameIndex);
   }
 
+  virtual const MachineOperand *isLoadFromStackSlotMO(const MachineInstr &MI,
+                                                      int &FrameIndex) const {
+    llvm_unreachable("target did not implement");
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RKSimon wrote:

Why not just return nullptr by default?

https://github.com/llvm/llvm-project/pull/118832