[PATCH] D140382: [CodeGen] Add user interface for DetectDeadLanes

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


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Comment at: llvm/lib/CodeGen/DetectDeadLanes.cpp:441
   bool Again = false;
+  if (!NeedSetUndef)
+    return std::make_pair(Changed, Again);
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Can we split this function into two functions above and below this point and check this flag in the while loop?


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Comment at: llvm/lib/CodeGen/DetectDeadLanes.cpp:489
   if (!MRI->subRegLivenessEnabled()) {
     LLVM_DEBUG(dbgs() << "Skipping Detect dead lanes pass\n");
     return false;
----------------
This debug message doesn't make sense for the call from the RISC-V pass.


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Comment at: llvm/lib/CodeGen/DetectDeadLanes.cpp:521
+bool DetectDeadLanes::runOnMachineFunction(MachineFunction &MF) {
+  // Don't bother if we won't track subregister liveness later.  This pass is
+  // required for correctness if subregister liveness is enabled because the
----------------
This comment belongs to the `if (!MRI->subRegLivenessEnabled())` that got moved.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D140382/new/

https://reviews.llvm.org/D140382