[PATCH] D29145: [NewGVN] Skip uses in unreachable blocks

[Davide Italiano via Phabricator via llvm-commits]

davide added a comment.

For archeologists:

  16:22 < davide> DannyB: I may be mistaken, but are we marking users in unreachable blocks with InstrDFSNum == 0 ? Currently we just set that if an instruction is trivially dead
  16:23 < davide> DannyB: in the example, the load with SSA name %tmp136 has InstrDFSNum zero, but the gep in bb138 has a non-zero InstrDFSNum
  16:24 < DannyB> oh interesting
  16:24 < DannyB> how did thathappen?
  16:24 < DannyB> oh
  16:24 < DannyB> yeah
  16:24 < DannyB> you are right
  16:24 < DannyB> because they may become reachable later
  16:24 < davide> yeah


https://reviews.llvm.org/D29145