[llvm] [AMDGPU] Analyze REG_SEQUENCE To Remove Redundant CMP Instructions (PR #167364)

[via llvm-commits]

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@@ -1312,6 +1312,30 @@ Register SIInstrInfo::insertNE(MachineBasicBlock *MBB,
   return Reg;
 }
 
+MachineInstr *
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LU-JOHN wrote:

I think it would be helpful to add a comment describing what is being done.  Something like:

For a 64-bit value defined by a REG_SEQUENCE with half of the result being 0, find the instruction that defines the other half.

https://github.com/llvm/llvm-project/pull/167364