[PATCH] D67500: [DebugInfo] LiveDebugValues: don't create transfer records for potentially invalid locations

[Adrian Prantl via Phabricator via llvm-commits]

aprantl added a comment.

> just don't record transfers until the in-locations are all known to be correct

I'm having trouble with this statement conceptually. Aren't in-locations coming in through join() always correct, just that we didn't reach a fixpoint yet? I'm assuming that at the beginning all in-locations are unknown and only when all incoming basic blocks have outgoing locations, join() adds new incoming locations to be processed. I guess this boils down to how we are not really modeling "unknown" currently?



================
Comment at: lib/CodeGen/LiveDebugValues.cpp:488
   void process(MachineInstr &MI, OpenRangesSet &OpenRanges,
-               VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
-               TransferMap &Transfers, DebugParamMap &DebugEntryVals,
-               OverlapMap &OverlapFragments,
+               VarLocMap &VarLocIDs, TransferMap *Transfers,
+               DebugParamMap &DebugEntryVals, OverlapMap &OverlapFragments,
----------------
When is Transfers null?


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D67500/new/

https://reviews.llvm.org/D67500