Fix a bug in the loop in JumpThreading::ProcessThreadableEdges() where it could falsely produce a MultipleDestSentinel value if the first predecessor ended with an 'indirectbr'. If that happened, it caused an unnecessary FindMostPopularDest() call.

This wasn't a correctness problem, but it broke the fast path for single-predecessor blocks.

llvm-svn: 121966

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index e59ae31e134..3d218a6585a 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -984,7 +984,7 @@ FindMostPopularDest(BasicBlock *BB,
     }
   }
 
-  // Okay, now we know the most popular destination.  If there is more than
+  // Okay, now we know the most popular destination.  If there is more than one
   // destination, we need to determine one.  This is arbitrary, but we need
   // to make a deterministic decision.  Pick the first one that appears in the
   // successor list.
@@ -1064,7 +1064,7 @@ bool JumpThreading::ProcessThreadableEdges(Value *Cond, BasicBlock *BB,
     }
 
     // If we have exactly one destination, remember it for efficiency below.
-    if (i == 0)
+    if (PredToDestList.empty())
       OnlyDest = DestBB;
     else if (OnlyDest != DestBB)
       OnlyDest = MultipleDestSentinel;