AMDGPU/SI: Handle hazard with sgpr lane selects for v_{read,write}lane

Reviewers: arsenm

Subscribers: kzhuravl, wdng, nhaehnle, yaxunl, tony-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D25637

llvm-svn: 285367
diff --git a/llvm/lib/Target/AMDGPU/GCNHazardRecognizer.h b/llvm/lib/Target/AMDGPU/GCNHazardRecognizer.h
index f0882d0..8b9ea6a 100644
--- a/llvm/lib/Target/AMDGPU/GCNHazardRecognizer.h
+++ b/llvm/lib/Target/AMDGPU/GCNHazardRecognizer.h
@@ -50,6 +50,7 @@
   int checkSetRegHazards(MachineInstr *SetRegInstr);
   int createsVALUHazard(const MachineInstr &MI);
   int checkVALUHazards(MachineInstr *VALU);
+  int checkRWLaneHazards(MachineInstr *RWLane);
 public:
   GCNHazardRecognizer(const MachineFunction &MF);
   // We can only issue one instruction per cycle.