diff options
| -rw-r--r-- | lib/Transforms/Scalar/JumpThreading.cpp | 5 | ||||
| -rw-r--r-- | test/Transforms/JumpThreading/2009-01-19-InfSwitchLoop.ll | 21 |
2 files changed, 26 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp index 94d33aa..f96fc20 100644 --- a/lib/Transforms/Scalar/JumpThreading.cpp +++ b/lib/Transforms/Scalar/JumpThreading.cpp @@ -419,6 +419,11 @@ bool JumpThreading::ProcessBranchOnDuplicateCond(BasicBlock *PredBB, /// switches out of repeated 'if' conditions. bool JumpThreading::ProcessSwitchOnDuplicateCond(BasicBlock *PredBB, BasicBlock *DestBB) { + // Can't thread edge to self. + if (PredBB == DestBB) + return false; + + SwitchInst *PredSI = cast<SwitchInst>(PredBB->getTerminator()); SwitchInst *DestSI = cast<SwitchInst>(DestBB->getTerminator()); diff --git a/test/Transforms/JumpThreading/2009-01-19-InfSwitchLoop.ll b/test/Transforms/JumpThreading/2009-01-19-InfSwitchLoop.ll new file mode 100644 index 0000000..ab8b087 --- /dev/null +++ b/test/Transforms/JumpThreading/2009-01-19-InfSwitchLoop.ll @@ -0,0 +1,21 @@ +; RUN: llvm-as < %s | opt -jump-threading | llvm-dis +; PR3353 + +define i32 @test(i8 %X) { +entry: + %Y = add i8 %X, 1 + %Z = add i8 %Y, 1 + br label %bb33.i + +bb33.i: ; preds = %bb33.i, %bb32.i + switch i8 %Y, label %bb32.i [ + i8 39, label %bb35.split.i + i8 13, label %bb33.i + ] + +bb35.split.i: + ret i32 5 +bb32.i: + ret i32 1 +} + |