[PATCH] D111219: [MachineCopyPropagation] Handle propagation of undef copies

[Carl Ritson via Phabricator via llvm-commits]

critson added inline comments.


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Comment at: llvm/lib/CodeGen/MachineCopyPropagation.cpp:579-580
       MOUse.setIsRenamable(false);
+    if (CopySrc.isUndef())
+      MOUse.setIsUndef(true);
 
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foad wrote:
> `MOUse.setIsUndef(CopySrc.isUndef())` would be a bit neater, and the same for isRenamable. Dunno if it makes any practical difference.
Sure.
Although doing that for isRenamable would definitely change output, so this change is probably not the right place for it.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111219/new/

https://reviews.llvm.org/D111219