[PATCH] D62543: [MIR-Canon] Add support for rewriting VRegs that are typed but don't have an RC.

[Saleem Abdulrasool via Phabricator via llvm-commits]

compnerd added inline comments.


================
Comment at: llvm/lib/CodeGen/MIRCanonicalizerPass.cpp:320
 
+static bool doVRegTypesMatch(const MachineRegisterInfo &MRI, unsigned VReg0,
+                             unsigned VReg1) {
----------------
I think that the `do` is superfluous


================
Comment at: llvm/lib/CodeGen/MIRCanonicalizerPass.cpp:325
+               ? true
+               : MRI.getType(VReg0) == MRI.getType(VReg1);
+  return false;
----------------
I think that this can just be `return MRI.getRegClassOrNull(VReg0) || MRI.getType(VReg0) == MRI.getType(VReg1);`


================
Comment at: llvm/lib/CodeGen/MIRCanonicalizerPass.cpp:519
     virtualVRegNumber++;
-
-    return MRI.createVirtualRegister(RC, OS.str());
+    if (RC)
+      return MRI.createVirtualRegister(RC, OS.str());
----------------
Why not sink the get into the conditional?

```
  if (auto RC = MRI.getRegClassOrNull(VReg))
    return MRI.createVirtualRegister(RC, OS.str());
```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D62543/new/

https://reviews.llvm.org/D62543