fix PR5698

llvm-svn: 90708
2009-12-06 17:17:23 +00:00
parent 7a141b3d88
commit 6d6f10fe91
2 changed files with 27 additions and 0 deletions
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -718,6 +718,11 @@ bool JumpThreading::ProcessSwitchOnDuplicateCond(BasicBlock *PredBB,
      if (PredSI->getSuccessor(PredCase) != DestBB &&
          DestSI->getSuccessor(i) != DestBB)
        continue;
+      
+      // Do not forward this if it already goes to this destination, this would
+      // be an infinite loop.
+      if (PredSI->getSuccessor(PredCase) == DestSucc)
+        continue;

      // Otherwise, we're safe to make the change.  Make sure that the edge from
      // DestSI to DestSucc is not critical and has no PHI nodes.