[PATCH] D126048: [SplitKit] Handle early clobber + tied to def correctly

[Kito Cheng via Phabricator via llvm-commits]

kito-cheng marked an inline comment as done.
kito-cheng added inline comments.


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Comment at: llvm/lib/CodeGen/SplitKit.cpp:1381
+        unsigned OpIdx = MI->getOperandNo(MOItr);
+        unsigned DefOpIdx = MI->findTiedOperandIdx(OpIdx);
+        const MachineOperand &DefOp = MI->getOperand(DefOpIdx);
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arcbbb wrote:
> The logic here looks similar to LiveIntervalCalc::extendToUses that checks for early-clobber redefs.
> Can it be simplified with `OpIdx = (&MO - &MI->getOperand(0))` and `MI->isRegTiedToDefOperand(OpIdx, &DefOpIdx)`?
`MI->getOperandNo(MOItr)` did almost similar thing[1] as `(&MO - &MI->getOperand(0))`, but having better readability.

And `isRegTiedToDefOperand` called `findTiedOperandIdx` in the function implementation[2], so I am not sure it's a simplification?

[1] https://llvm.org/doxygen/MachineInstr_8h_source.html#l00685
[2] https://llvm.org/doxygen/MachineInstr_8h_source.html#l00685


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