[PATCH] D45279: [LoopInterchange] Use getExitBlock()/getExitingBlock instead of manual impl.

[Florian Hahn via Phabricator via llvm-commits]

fhahn added inline comments.


================
Comment at: lib/Transforms/Scalar/LoopInterchange.cpp:865
   // TODO: We only handle LCSSA PHI's corresponding to reduction for now.
-  BasicBlock *LoopExitBlock =
-      getLoopLatchExitBlock(OuterLoopLatch, OuterLoopHeader);
-  if (!LoopExitBlock || !containsSafePHI(LoopExitBlock, true)) {
+  BasicBlock *OuterExit = OuterLoop->getExitBlock();
+  if (!OuterExit || !containsSafePHI(OuterExit, true)) {
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efriedma wrote:
> fhahn wrote:
> > efriedma wrote:
> > > Is it actually possible for OuterExit to be null here?
> > I had a look and could not spot any other checks ensuring we have a unique exit block.
> processLoopList contains an identical check. And I think `OuterLoop->getExitingBlock() == OuterLoop->getLoopLatch() && isa<BranchInst>(OuterLoop->getLoopLatch()->getTerminator())` implies the exit is unique. 
There's one check to ensure the outermost loop in a nest has a unique exit block in processLoopList. Ah yes, the check Latch == single exiting block & isa<BranchInst> should guarantee that we  have a unique exit block, thanks!


================
Comment at: lib/Transforms/Scalar/LoopInterchange.cpp:555
+    return false;
+  }
 
----------------
efriedma wrote:
> What is this closing brace doing here?
> 
> Also, the indentation looks weird.
Argh, sorry about that. Should be fixed now


https://reviews.llvm.org/D45279