[LoopPredication] NFC. Add extra debug output in case we fail to parse the range...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303544 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/LoopPredication.cpp b/lib/Transforms/Scalar/LoopPredication.cpp
index e538b7070b8851dab808336f64cab598fafcac51..32fd3da465feafc6b5fb4ef852c02e71c3ade2cf 100644 (file)
--- a/lib/Transforms/Scalar/LoopPredication.cpp
+++ b/lib/Transforms/Scalar/LoopPredication.cpp
@@ -182,8 +182,10 @@ Optional<Value *> LoopPredication::widenICmpRangeCheck(ICmpInst *ICI,
   DEBUG(ICI->dump());
 
   auto RangeCheck = parseLoopICmp(ICI);
-  if (!RangeCheck)
+  if (!RangeCheck) {
+    DEBUG(dbgs() << "Failed to parse the loop latch condition!\n");
     return None;
+  }
 
   ICmpInst::Predicate Pred = RangeCheck->Pred;
   const SCEVAddRecExpr *IndexAR = RangeCheck->IV;