[PATCH] D58524: [LoopSimplifyCFG] Update MemorySSA after r353911.

Thu Feb 21 23:31:29 PST 2019

asbirlea marked 2 inline comments as done.
asbirlea added inline comments.

================
Comment at: llvm/trunk/lib/Transforms/Scalar/LoopSimplifyCFG.cpp:592
       // If we didn't do updates inside deleteDeadLoopBlocks, do them here.
       DTU.applyUpdates(DTUpdates);
       DTUpdates.clear();
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mkazantsev wrote:
> I believe we should also update MSSA here. This is the execution path taken when we don't have dead blocks.
Thanks for looking at this!
I believe all updates are already done at this point as far as MemorySSA is concerned.
All updates are cleared at the end of handleDeadExits, and foldTerminators only removed edges which are safe to handle with the removeEdge API (done already inside the method).
Everything needs to be correct by the time we delete blocks anyway, since deleting assumes a correct CFG+MSSA.

If you have a case showing otherwise, I'll be happy to take a look.

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D58524/new/

https://reviews.llvm.org/D58524