[PATCH] D52002: Omit range checks from jump tables when lowering switches with unreachable default

[Hans Wennborg via Phabricator via llvm-commits]

hans added a comment.

Thanks! Almost there.



================
Comment at: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:9452
+              isa<UnreachableInst>(SI->getDefaultDest()->getFirstNonPHIOrDbg());
+  bool OmitRangeCheck = UnreachableDefault  &&  SI->getNumCases() > 0;
   JumpTable JT(-1U, JTI, JumpTableMBB, nullptr);
----------------
hans wrote:
> There seems to be an extra space between "Default" and "&&". Also, why do we need the SI->getNumCases() check?
This comment was never addressed.


================
Comment at: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:9475
+  bool UnreachableDefault =
+              isa<UnreachableInst>(SI->getDefaultDest()->getFirstNonPHIOrDbg());
+  bool OmitRangeCheck = UnreachableDefault  &&  SI->getNumCases() > 0;
----------------
nit: The indent is deeper than what LLVM code normally uses. I think it should be

```
  bool UnreachableDefault = 
      isa<UnreachableInst>(SI->getDefaultDest()->getFirstNonPHIOrDbg());
```


================
Comment at: test/CodeGen/AArch64/switch-unreachable-default.ll:53
+
+return_label:   ; preds = %case_5, %case_4, %case_3, %case_2, %case_1, %case_0
+  ret void
----------------
nit: you could drop the "; preds" comment too.


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https://reviews.llvm.org/D52002