[llvm] [VPlan] Generalize collectUsersInExitBlocks for multiple exit bbs. (PR #115066)

[Florian Hahn via llvm-commits]

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@@ -3837,6 +3837,10 @@ class VPlan {
     return cast<VPBasicBlock>(getVectorLoopRegion()->getSingleSuccessor());
   }
 
+  /// Return the exit blocks of the VPlan, that is leaf nodes except the scalar
+  /// header.
+  auto getExitBlocks();
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fhahn wrote:

It is a bit unfortunate but I couldn't find a way to do that, as it needs accesses to the definition of `VPBlockShallowTraversalWrapper` to spell out the full type (other than moving everything in VPlanCFG back to this file).

There may be another way to spell out the type I am not aware of (it is a few nests of various iterator range adopters). For now I extended the comment to provide more information

https://github.com/llvm/llvm-project/pull/115066