[llvm] [AArch64][GlobalISel] Fix incorrect codegen for FPR16/FPR8 to GPR copies (PR #171499)

[Matt Arsenault via llvm-commits]

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@@ -5804,6 +5804,102 @@ void AArch64InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
     return;
   }
 
+  // Copies between GPR32 and FPR16.
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arsenm wrote:

copyPhysReg shouldn't need to handle new situations for globalisel. If a copy is reaching here that doesn't in the DAG, the selected MIR is probably malformed and should probably look more like the DAG's output coming out of selection 

https://github.com/llvm/llvm-project/pull/171499