Dummy MSP430 backend

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70694 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp b/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
new file mode 100644
index 0000000..eefc1a0
--- /dev/null
+++ b/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
@@ -0,0 +1,84 @@
+//===-- MSP430ISelDAGToDAG.cpp - A dag to dag inst selector for MSP430 ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines an instruction selector for the MSP430 target.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MSP430.h"
+#include "MSP430ISelLowering.h"
+#include "MSP430TargetMachine.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/CallingConv.h"
+#include "llvm/Constants.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/SelectionDAGISel.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include <queue>
+#include <set>
+using namespace llvm;
+
+/// MSP430DAGToDAGISel - MSP430 specific code to select MSP430 machine
+/// instructions for SelectionDAG operations.
+///
+namespace {
+  class MSP430DAGToDAGISel : public SelectionDAGISel {
+    MSP430TargetLowering &Lowering;
+    const MSP430Subtarget &Subtarget;
+
+  public:
+    MSP430DAGToDAGISel(MSP430TargetMachine &TM)
+      : SelectionDAGISel(TM),
+        Lowering(*TM.getTargetLowering()),
+        Subtarget(*TM.getSubtargetImpl()) { }
+
+    virtual void InstructionSelect();
+
+    virtual const char *getPassName() const {
+      return "MSP430 DAG->DAG Pattern Instruction Selection";
+    }
+
+    // Include the pieces autogenerated from the target description.
+  #include "MSP430GenDAGISel.inc"
+
+  private:
+    SDNode *Select(SDValue Op);
+  };
+}  // end anonymous namespace
+
+/// createMSP430ISelDag - This pass converts a legalized DAG into a
+/// MSP430-specific DAG, ready for instruction scheduling.
+///
+FunctionPass *llvm::createMSP430ISelDag(MSP430TargetMachine &TM) {
+  return new MSP430DAGToDAGISel(TM);
+}
+
+/// InstructionSelect - This callback is invoked by
+/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
+void MSP430DAGToDAGISel::
+InstructionSelect() {
+  DEBUG(BB->dump());
+
+  // Select target instructions for the DAG.
+  SelectRoot(*CurDAG);
+
+  CurDAG->RemoveDeadNodes();
+}
+
+SDNode *MSP430DAGToDAGISel::Select(SDValue Op) {
+  return SelectCode(Op);
+}