[PATCH] D123581: [RISCV] Teach vsetvli insertion to handle VSETVLIInfo of vl-modified instruction.

[Yeting Kuo via Phabricator via llvm-commits]

fakepaper56 added inline comments.


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Comment at: llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp:57
 
+  const MachineInstr *VLModifier;
+
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jacquesguan wrote:
> Maybe no need to save a pointer in the `VSETVLIInfo`?   I think that we only care about if the previous `VSETVLIInfo` is from a VL modified MI and the current AVL is read from the result of the modified VL. I think maybe we could use a local pointer in `emitVSETVLIs` or somewhere you would like to use it.
The patch also supports `emitVSETVLIPHIs` which detects the `VSETVLIInfo` of predecessors. I think it is hard to introduce "previous" `VSETVLIInfo` into multiple predecessors.


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  https://reviews.llvm.org/D123581/new/

https://reviews.llvm.org/D123581