[PATCH] D103408: DetectDeadLanes: Remove assert for subregister defs

[Nemanja Ivanovic via Phabricator via llvm-commits]

nemanjai added inline comments.


================
Comment at: llvm/lib/CodeGen/DetectDeadLanes.cpp:343-344
 
-  assert(Def.getSubReg() == 0 &&
-         "Should not have subregister defs in machine SSA phase");
+  unsigned SubIdx = Def.getSubReg();
+  DefinedLanes = TRI->composeSubRegIndexLaneMask(SubIdx, DefinedLanes);
   DefinedLanes &= MRI->getMaxLaneMaskForVReg(Def.getReg());
----------------
Can this be conditional so we don't change the behaviour of the common case?
```
if (unsigned SubIdx = Def.getSubReg())
  DefinedLanes = TRI->composeSubRegIndexLaneMask(SubIdx, DefinedLanes);
```


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  https://reviews.llvm.org/D103408/new/

https://reviews.llvm.org/D103408