[llvm] [RegisterCoalescer]: Try inflated RC for coalescing reg->subreg (PR #134438)

[Matt Arsenault via llvm-commits]

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@@ -477,7 +477,9 @@ bool CoalescerPair::setRegisters(const MachineInstr *MI) {
     Flipped = true;
   }
 
-  const MachineRegisterInfo &MRI = MI->getMF()->getRegInfo();
+  const MachineFunction *MF = MI->getMF();
+
+  const MachineRegisterInfo &MRI = MF->getRegInfo();
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arsenm wrote:

Probably should just pass this as an argument to setRegisters 

https://github.com/llvm/llvm-project/pull/134438