[PATCH] D64553: [LoopUtils] Extend the scope of getLoopEstimatedTripCount

[Serguei Katkov via Phabricator via llvm-commits]

skatkov marked an inline comment as done.
skatkov added inline comments.


================
Comment at: llvm/lib/Transforms/Utils/LoopUtils.cpp:628
   // Get the branch weights for the loop's backedge.
-  BranchInst *LatchBR =
-      dyn_cast<BranchInst>(L->getLoopLatch()->getTerminator());
-  if (!LatchBR || LatchBR->getNumSuccessors() != 2)
+  BasicBlock *Latch = L->getLoopLatch();
+  BranchInst *LatchBR = dyn_cast<BranchInst>(Latch->getTerminator());
----------------
reames wrote:
> There's a missing correctness check here.  There's no guarantee that a loop *must* have a unique latch, so you need null check the result before dereferencing.  Non unique latches are non-canonical, so you can just bail on that case.
> 
> Note that unique exit implies unique latch previously.
To be honest I do not understand how unique exit implies unique latch but I can add additional check.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D64553/new/

https://reviews.llvm.org/D64553