[PATCH] D86253: [AMDGPU] Disable stall weight calculation in regbank-reassign

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/GCNRegBankReassign.cpp:119
       if (C.Weight) push_back(C);
       else push_front(C);
     }
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critson wrote:
> Is push_front more expensive if we are calling it for every candidate?
> Probably just always push_back?
It's a list, cost of insertion is O(1).


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Comment at: llvm/lib/Target/AMDGPU/GCNRegBankReassign.cpp:605
       unsigned Weight = getOperandGatherWeight(MI, Reg1, Reg2, StallCycles);
       Weight += MLI->getLoopDepth(MI.getParent()) * 10;
 
----------------
critson wrote:
> Presumably we don't need to do this if we are not using weights at all (i.e. no sorting)?
> Perhaps "if (UseWeight)" all of this?
Good point. It is cheap, but still.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86253/new/

https://reviews.llvm.org/D86253