[PATCH] D130895: [RISCV] Make VL choosing for a splat-like VMV based on its users

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


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Comment at: llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp:2464
+  assert(!Range.empty() && "Invalid range");
+  std::pair<SDValue, uint64_t> MaxVL{SDValue{}, 0};
+  for (SDNode *Node : Range) {
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I think this would be cleaner as two named variables.


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Comment at: llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp:2544
+  Ops[Node->getNumOperands() - 1] = VL;
+  CurDAG->UpdateNodeOperands(Node, Ops);
+}
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UpdateNodeOperands potentially returns a different pointer than `Node` if it triggered CSE internally. In that case you need to Replace all uses of `Node` with the value returned and not run any of the code in caller. See the UpdateNodeOperands call in `X86DAGToDAGISel::tryShiftAmountMod` for a similar case.


Repository:
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  https://reviews.llvm.org/D130895/new/

https://reviews.llvm.org/D130895