1 files changed, 7 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopVersioning.cpp b/llvm/lib/Transforms/Utils/LoopVersioning.cpp
index ec2e6c1..9c8b6ef 100644
--- a/llvm/lib/Transforms/Utils/LoopVersioning.cpp
+++ b/llvm/lib/Transforms/Utils/LoopVersioning.cpp
@@ -23,6 +23,7 @@
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/IR/PassManager.h"
+#include "llvm/IR/ProfDataUtils.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
@@ -109,8 +110,12 @@ void LoopVersioning::versionLoop(
   // Insert the conditional branch based on the result of the memchecks.
   Instruction *OrigTerm = RuntimeCheckBB->getTerminator();
   Builder.SetInsertPoint(OrigTerm);
-  Builder.CreateCondBr(RuntimeCheck, NonVersionedLoop->getLoopPreheader(),
-                       VersionedLoop->getLoopPreheader());
+  auto *BI =
+      Builder.CreateCondBr(RuntimeCheck, NonVersionedLoop->getLoopPreheader(),
+                           VersionedLoop->getLoopPreheader());
+  // We don't know what the probability of executing the versioned vs the
+  // unversioned variants is.
+  setExplicitlyUnknownBranchWeightsIfProfiled(*BI, DEBUG_TYPE);
   OrigTerm->eraseFromParent();
 
   // The loops merge in the original exit block.  This is now dominated by the