[PATCH] D92405: [VirtRegRewriter] Insert missing killed flags when tracking subregister liveness

[Kai Luo via Phabricator via llvm-commits]

lkail added inline comments.


================
Comment at: llvm/lib/CodeGen/LiveIntervals.cpp:794-795
+            if (MO.getSubReg() == 0)
+              if (const TargetRegisterClass *TRC = MRI->getRegClassOrNull(Reg))
+                UseMask = TRC->getLaneMask();
             if ((UseMask & ~DefinedLanesMask).any())
----------------
arsenm wrote:
> getRegClass should be sufficient. There can't be a vreg without a class at this point
I think it can be simplified as
```
            unsigned SubReg = MO.getSubReg();
            LaneBitmask UseMask = SubReg ? TRI->getSubRegIndexLaneMask(SubReg)
                                         : MRI->getMaxLaneMaskForVReg(Reg);

```


Repository:
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  https://reviews.llvm.org/D92405/new/

https://reviews.llvm.org/D92405