[PATCH] D152502: [MCP] Do not remove redundant copy for COPY from undef

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: llvm/test/CodeGen/X86/machine-copy-prop.mir:227
+# CHECK-NEXT: NOOP implicit $rax, implicit $rdi
+name: nocopyprop6
+body: |
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Pierre-vh wrote:
> arsenm wrote:
> > I think tracksRegLiveness strikes again (why is this an option?)
> Indeed, it's because `tracksRegLiveness` is false. If I set it to true it indeed fails the verifier.
> I just copied and slightly modified a test in the same file, so I think it's alright. Would you prefer if I changed it? I guess I just need an implicit def of $rdi 
Then all the tests are broken. They should all enable liveness 


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  https://reviews.llvm.org/D152502/new/

https://reviews.llvm.org/D152502