[PATCH] D137483: [NFC][PowerPC] Add NFC fixes to PPCInstrinfo.cpp when getting the defined machine instruction.

Amy Kwan via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Nov 15 22:15:58 PST 2022


amyk added inline comments.


================
Comment at: llvm/lib/Target/PowerPC/PPCInstrInfo.cpp:3394
+        } else
+          DefMI = nullptr;
       }
----------------
shchenz wrote:
> If `OpNoForForwarding` is not changed, then the reassigned `DefMI` will not be used. Do you find any issue for this?
Thanks for your comment. I believe if `OpNoForForwarding` remains as `~0U` like it is in the beginning in this case, then we did not end up finding a valid operand in pre-SSA form.

I realize that we also anticipate that `DefMI` would be null as at the end we have, 
```
return OpNoForForwarding == ~0U ? nullptr : DefMI;
```
Which will indicate that we’ll return a null `DefMI` if `OpNoForForwarding` doesn’t end up getting updated.

Thus, I don’t believe this is an issue, but please do let me know if I have misunderstood your question.


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137483/new/

https://reviews.llvm.org/D137483



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