[PATCH] D98659: [MachineCopyPropagation] Do more backward copy propagations

[Kai Luo via Phabricator via llvm-commits]

lkail added inline comments.


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Comment at: llvm/lib/CodeGen/MachineCopyPropagation.cpp:54
+//    $R2 = OP $R0 // $R0 is used
+//    $R1 = COPY $R0 // $R0 is killed
+// Replace $R0 and its uses with $R1 and remove the COPY
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Is it possible forward copy propagation can also eliminate this COPY if `$R1` defined by this COPY is killed at the BB later? If so, I think we should extend forward copy propagation and should be less complex than what current patch does.


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Comment at: llvm/lib/CodeGen/MachineCopyPropagation.cpp:283
+  /// Find the corresponding copy instruction where \p RegUnit appeared as the
+  /// Src
   MachineInstr *findCopyDefViaUnit(MCRegister RegUnit,
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Missing perid.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D98659/new/

https://reviews.llvm.org/D98659