diff --git a/llvm/lib/Target/AMDGPU/R600ISelLowering.h b/llvm/lib/Target/AMDGPU/R600ISelLowering.h
index 9135f778edf06..e7706fa0ef5ce 100644
--- a/llvm/lib/Target/AMDGPU/R600ISelLowering.h
+++ b/llvm/lib/Target/AMDGPU/R600ISelLowering.h
@@ -74,7 +74,7 @@ class R600TargetLowering final : public AMDGPUTargetLowering {
 
   void lowerImplicitParameter(MachineInstr *MI, MachineBasicBlock &BB,
       MachineRegisterInfo & MRI, unsigned dword_offset) const;
-  SDValue OptimizeSwizzle(SDValue BuildVector, SDValue Swz[4],
+  SDValue OptimizeSwizzle(SDValue BuildVector, SDValue Swz[],
                           SelectionDAG &DAG, const SDLoc &DL) const;
   SDValue vectorToVerticalVector(SelectionDAG &DAG, SDValue Vector) const;