[LoopVersioning] Form dedicated exits for versioned loop to preserve simplify form

The exit blocks of the versioned and non-versioned loops are not dedicated and thus the two loops are not in simplify form.
Insert dummy exit blocks after loop versioning with `formDedicatedExits()` to preserve the simplify form for subsequence passes.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D89569

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopVersioning.cpp b/llvm/lib/Transforms/Utils/LoopVersioning.cpp
index f3170a1..03eb41b 100644
--- a/llvm/lib/Transforms/Utils/LoopVersioning.cpp
+++ b/llvm/lib/Transforms/Utils/LoopVersioning.cpp
@@ -117,6 +117,11 @@ void LoopVersioning::versionLoop(
   // Adds the necessary PHI nodes for the versioned loops based on the
   // loop-defined values used outside of the loop.
   addPHINodes(DefsUsedOutside);
+  formDedicatedExitBlocks(NonVersionedLoop, DT, LI, nullptr, true);
+  formDedicatedExitBlocks(VersionedLoop, DT, LI, nullptr, true);
+  assert(NonVersionedLoop->isLoopSimplifyForm() &&
+         VersionedLoop->isLoopSimplifyForm() &&
+         "The versioned loops should be in simplify form.");
 }
 
 void LoopVersioning::addPHINodes(