1 files changed, 7 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/Sink.cpp b/lib/Transforms/Scalar/Sink.cpp
index 5e1e4564bb..41073749ab 100644
--- a/lib/Transforms/Scalar/Sink.cpp
+++ b/lib/Transforms/Scalar/Sink.cpp
@@ -216,6 +216,13 @@ bool Sinking::IsAcceptableTarget(Instruction *Inst,
 /// instruction out of its current block into a successor.
 bool Sinking::SinkInstruction(Instruction *Inst,
                               SmallPtrSet<Instruction *, 8> &Stores) {
+
+  // Don't sink static alloca instructions.  CodeGen assumes allocas outside the
+  // entry block are dynamically sized stack objects.
+  if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst))
+    if (AI->isStaticAlloca())
+      return false;
+
   // Check if it's safe to move the instruction.
   if (!isSafeToMove(Inst, AA, Stores))
     return false;