diff options
| -rw-r--r-- | lib/Transforms/Vectorize/LoopVectorize.cpp | 6 | ||||
| -rw-r--r-- | test/Transforms/LoopVectorize/2012-10-20-infloop.ll | 12 |
2 files changed, 18 insertions, 0 deletions
diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index c11c66f1ae..027fe0656b 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -1175,6 +1175,12 @@ bool LoopVectorizationLegality::AddReductionVar(PHINode *Phi, bool FoundInBlockUser = false; // Did we reach the initial PHI node ? bool FoundStartPHI = false; + + // If the instruction has no users then this is a broken + // chain and can't be a reduction variable. + if (Iter->use_begin() == Iter->use_end()) + return false; + // For each of the *users* of iter. for (Value::use_iterator it = Iter->use_begin(), e = Iter->use_end(); it != e; ++it) { diff --git a/test/Transforms/LoopVectorize/2012-10-20-infloop.ll b/test/Transforms/LoopVectorize/2012-10-20-infloop.ll new file mode 100644 index 0000000000..16a7729199 --- /dev/null +++ b/test/Transforms/LoopVectorize/2012-10-20-infloop.ll @@ -0,0 +1,12 @@ +; RUN: opt < %s -loop-vectorize -dce + +; Check that we don't fall into an infinite loop. +define void @test() nounwind { +entry: + br label %for.body + +for.body: + %0 = phi i32 [ 1, %entry ], [ 0, %for.body ] + br label %for.body +} + |