1 files changed, 194 insertions, 0 deletions
diff --git a/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp b/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
new file mode 100644
index 000000000000..bf49ec0bff46
--- /dev/null
+++ b/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
@@ -0,0 +1,194 @@
+//===-- 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"
+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, CodeGenOpt::Level OptLevel)
+      : SelectionDAGISel(TM, OptLevel),
+        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);
+    bool SelectAddr(SDValue Op, SDValue Addr, SDValue &Base, SDValue &Disp);
+
+  #ifndef NDEBUG
+    unsigned Indent;
+  #endif
+  };
+}  // end anonymous namespace
+
+/// createMSP430ISelDag - This pass converts a legalized DAG into a
+/// MSP430-specific DAG, ready for instruction scheduling.
+///
+FunctionPass *llvm::createMSP430ISelDag(MSP430TargetMachine &TM,
+                                        CodeGenOpt::Level OptLevel) {
+  return new MSP430DAGToDAGISel(TM, OptLevel);
+}
+
+// FIXME: This is pretty dummy routine and needs to be rewritten in the future.
+bool MSP430DAGToDAGISel::SelectAddr(SDValue Op, SDValue Addr,
+                                    SDValue &Base, SDValue &Disp) {
+  // Try to match frame address first.
+  if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
+    Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16);
+    Disp = CurDAG->getTargetConstant(0, MVT::i16);
+    return true;
+  }
+
+  switch (Addr.getOpcode()) {
+  case ISD::ADD:
+   // Operand is a result from ADD with constant operand which fits into i16.
+   if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
+      uint64_t CVal = CN->getZExtValue();
+      // Offset should fit into 16 bits.
+      if (((CVal << 48) >> 48) == CVal) {
+        SDValue N0 = Addr.getOperand(0);
+        if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(N0))
+          Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16);
+        else
+          Base = N0;
+
+        Disp = CurDAG->getTargetConstant(CVal, MVT::i16);
+        return true;
+      }
+    }
+    break;
+  case MSP430ISD::Wrapper:
+    SDValue N0 = Addr.getOperand(0);
+    if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(N0)) {
+      Base = CurDAG->getTargetGlobalAddress(G->getGlobal(),
+                                            MVT::i16, G->getOffset());
+      Disp = CurDAG->getTargetConstant(0, MVT::i16);
+      return true;
+    } else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(N0)) {
+      Base = CurDAG->getTargetExternalSymbol(E->getSymbol(), MVT::i16);
+      Disp = CurDAG->getTargetConstant(0, MVT::i16);
+    }
+    break;
+  };
+
+  Base = Addr;
+  Disp = CurDAG->getTargetConstant(0, MVT::i16);
+
+  return true;
+}
+
+
+
+/// InstructionSelect - This callback is invoked by
+/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
+void MSP430DAGToDAGISel::InstructionSelect() {
+  DEBUG(BB->dump());
+
+  // Codegen the basic block.
+#ifndef NDEBUG
+  DOUT << "===== Instruction selection begins:\n";
+  Indent = 0;
+#endif
+  SelectRoot(*CurDAG);
+#ifndef NDEBUG
+  DOUT << "===== Instruction selection ends:\n";
+#endif
+
+  CurDAG->RemoveDeadNodes();
+}
+
+SDNode *MSP430DAGToDAGISel::Select(SDValue Op) {
+  SDNode *Node = Op.getNode();
+  DebugLoc dl = Op.getDebugLoc();
+
+  // Dump information about the Node being selected
+  #ifndef NDEBUG
+  DOUT << std::string(Indent, ' ') << "Selecting: ";
+  DEBUG(Node->dump(CurDAG));
+  DOUT << "\n";
+  Indent += 2;
+  #endif
+
+  // If we have a custom node, we already have selected!
+  if (Node->isMachineOpcode()) {
+    #ifndef NDEBUG
+    DOUT << std::string(Indent-2, ' ') << "== ";
+    DEBUG(Node->dump(CurDAG));
+    DOUT << "\n";
+    Indent -= 2;
+    #endif
+    return NULL;
+  }
+
+  // Few custom selection stuff.
+  switch (Node->getOpcode()) {
+  default: break;
+  case ISD::FrameIndex: {
+    assert(Op.getValueType() == MVT::i16);
+    int FI = cast<FrameIndexSDNode>(Node)->getIndex();
+    SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i16);
+    if (Node->hasOneUse())
+      return CurDAG->SelectNodeTo(Node, MSP430::ADD16ri, MVT::i16,
+                                  TFI, CurDAG->getTargetConstant(0, MVT::i16));
+    return CurDAG->getTargetNode(MSP430::ADD16ri, dl, MVT::i16,
+                                 TFI, CurDAG->getTargetConstant(0, MVT::i16));
+  }
+  }
+
+  // Select the default instruction
+  SDNode *ResNode = SelectCode(Op);
+
+  #ifndef NDEBUG
+  DOUT << std::string(Indent-2, ' ') << "=> ";
+  if (ResNode == NULL || ResNode == Op.getNode())
+    DEBUG(Op.getNode()->dump(CurDAG));
+  else
+    DEBUG(ResNode->dump(CurDAG));
+  DOUT << "\n";
+  Indent -= 2;
+  #endif
+
+  return ResNode;
+}