[PATCH] D75421: [AArch64][GlobalISel] Avoid copies to target register bank for subregister copies

[Jessica Paquette via Phabricator via llvm-commits]

paquette added inline comments.


================
Comment at: llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp:658
+                       const TargetRegisterClass *To, unsigned SubReg) {
   MachineIRBuilder MIB(I);
+  auto SubRegCopy =
----------------
While we're here, I think it would be good to add a couple asserts:

```
assert(SrcReg.isValid() && "Expected a valid source register?");
assert(To && "Destination register class cannot be null");
assert(SubReg && "Expected a valid subregister");
```




CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75421/new/

https://reviews.llvm.org/D75421