Rough first pass at compare_and_swap atomic builtins for ARM mode. Work in progress.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91090 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.h b/lib/Target/ARM/ARMISelLowering.h
index c9cbbc6..64e0e0d 100644
--- a/lib/Target/ARM/ARMISelLowering.h
+++ b/lib/Target/ARM/ARMISelLowering.h
@@ -331,6 +331,10 @@
 
     SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
                       SDValue &ARMCC, SelectionDAG &DAG, DebugLoc dl);
+
+    MachineBasicBlock *EmitAtomicCmpSwap(unsigned Size, MachineInstr *MI,
+                                         MachineBasicBlock *BB) const;
+
   };
 }