diff options
| -rw-r--r-- | lib/Transforms/Scalar/JumpThreading.cpp | 5 | ||||
| -rw-r--r-- | test/Transforms/JumpThreading/crash.ll | 22 |
2 files changed, 27 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp index 1b93f3441e..d58b9c9de0 100644 --- a/lib/Transforms/Scalar/JumpThreading.cpp +++ b/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. diff --git a/test/Transforms/JumpThreading/crash.ll b/test/Transforms/JumpThreading/crash.ll index b2b9d69e16..361ec6cfb5 100644 --- a/test/Transforms/JumpThreading/crash.ll +++ b/test/Transforms/JumpThreading/crash.ll @@ -212,3 +212,25 @@ bb13: bb61: ret void } + + +; PR5698 +define void @test7(i32 %x) { +tailrecurse: + switch i32 %x, label %return [ + i32 2, label %bb2 + i32 3, label %bb + ] + +bb: + switch i32 %x, label %return [ + i32 2, label %bb2 + i32 3, label %tailrecurse + ] + +bb2: + ret void + +return: + ret void +} |