Do not generate by TableGen the hard-coded standard, target-independent part of

DAG instruction selectors. Introudce a dedicated header file for this part:
include/llvm/CodeGen/DAGISelHeader.h

TableGen now only generates the include preprocessor directive to include this
new header.

This is a preparation for supporting multiple implementations of instruction
selectors in the future.

Reviewed and approved by Evan and Dan.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51102 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 140 deletions

diff --git a/utils/TableGen/DAGISelEmitter.cpp b/utils/TableGen/DAGISelEmitter.cpp
index 70d88cea45..72bd5bdb2f 100644
--- a/utils/TableGen/DAGISelEmitter.cpp
+++ b/utils/TableGen/DAGISelEmitter.cpp
@@ -2011,147 +2011,10 @@ void DAGISelEmitter::run(std::ostream &OS) {
   OS << "// *** NOTE: This file is #included into the middle of the target\n"
      << "// *** instruction selector class.  These functions are really "
      << "methods.\n\n";
-  
-  OS << "// Instruction selector priority queue:\n"
-     << "std::vector<SDNode*> ISelQueue;\n";
-  OS << "/// Keep track of nodes which have already been added to queue.\n"
-     << "unsigned char *ISelQueued;\n";
-  OS << "/// Keep track of nodes which have already been selected.\n"
-     << "unsigned char *ISelSelected;\n";
-
-
-  OS << "/// IsChainCompatible - Returns true if Chain is Op or Chain does\n";
-  OS << "/// not reach Op.\n";
-  OS << "static bool IsChainCompatible(SDNode *Chain, SDNode *Op) {\n";
-  OS << "  if (Chain->getOpcode() == ISD::EntryToken)\n";
-  OS << "    return true;\n";
-  OS << "  else if (Chain->getOpcode() == ISD::TokenFactor)\n";
-  OS << "    return false;\n";
-  OS << "  else if (Chain->getNumOperands() > 0) {\n";
-  OS << "    SDOperand C0 = Chain->getOperand(0);\n";
-  OS << "    if (C0.getValueType() == MVT::Other)\n";
-  OS << "      return C0.Val != Op && IsChainCompatible(C0.Val, Op);\n";
-  OS << "  }\n";
-  OS << "  return true;\n";
-  OS << "}\n";
-
-  OS << "/// Sorting functions for the selection queue.\n"
-     << "struct isel_sort : public std::binary_function"
-     << "<SDNode*, SDNode*, bool> {\n"
-     << "  bool operator()(const SDNode* left, const SDNode* right) "
-     << "const {\n"
-     << "    return (left->getNodeId() > right->getNodeId());\n"
-     << "  }\n"
-     << "};\n\n";
-
-  OS << "inline void setQueued(int Id) {\n";
-  OS << "  ISelQueued[Id / 8] |= 1 << (Id % 8);\n";
-  OS << "}\n";
-  OS << "inline bool isQueued(int Id) {\n";
-  OS << "  return ISelQueued[Id / 8] & (1 << (Id % 8));\n";
-  OS << "}\n";
-  OS << "inline void setSelected(int Id) {\n";
-  OS << "  ISelSelected[Id / 8] |= 1 << (Id % 8);\n";
-  OS << "}\n";
-  OS << "inline bool isSelected(int Id) {\n";
-  OS << "  return ISelSelected[Id / 8] & (1 << (Id % 8));\n";
-  OS << "}\n\n";
-
-  OS << "void AddToISelQueue(SDOperand N) DISABLE_INLINE {\n";
-  OS << "  int Id = N.Val->getNodeId();\n";
-  OS << "  if (Id != -1 && !isQueued(Id)) {\n";
-  OS << "    ISelQueue.push_back(N.Val);\n";
- OS << "    std::push_heap(ISelQueue.begin(), ISelQueue.end(), isel_sort());\n";
-  OS << "    setQueued(Id);\n";
-  OS << "  }\n";
-  OS << "}\n\n";
 
-  
-  OS << "class VISIBILITY_HIDDEN ISelQueueUpdater :\n";
-  OS << "  public SelectionDAG::DAGUpdateListener {\n";
-  OS << "    std::vector<SDNode*> &ISelQueue;\n";
-  OS << "    bool HadDelete;\n";
-  OS << "  public:\n";
-  OS << "    explicit ISelQueueUpdater(std::vector<SDNode*> &isq)\n";
-  OS << "      : ISelQueue(isq), HadDelete(false) {}\n";
-  OS << "    \n";
-  OS << "    bool hadDelete() const { return HadDelete; }\n";
-  OS << "    \n";
-  OS << "    virtual void NodeDeleted(SDNode *N) {\n";
-  OS << "      ISelQueue.erase(std::remove(ISelQueue.begin(), ISelQueue.end(),";
-  OS << " N),\n                      ISelQueue.end());\n";
-  OS << "      HadDelete = true;\n";
-  OS << "    }\n";
-  OS << "    \n";
-  OS << "    // Ignore updates.\n";
-  OS << "    virtual void NodeUpdated(SDNode *N) {}\n";
-  OS << "  };\n";
-  
-  OS << "inline void UpdateQueue(const ISelQueueUpdater &ISQU) {\n";
-  OS << "  if (ISQU.hadDelete())\n";
-  OS << "    std::make_heap(ISelQueue.begin(), ISelQueue.end(),isel_sort());\n";
-  OS << "}\n\n";
-
-  OS << "void ReplaceUses(SDOperand F, SDOperand T) DISABLE_INLINE {\n";
-  OS << "  ISelQueueUpdater ISQU(ISelQueue);\n";
-  OS << "  CurDAG->ReplaceAllUsesOfValueWith(F, T, &ISQU);\n";
-  OS << "  setSelected(F.Val->getNodeId());\n";
-  OS << "  UpdateQueue(ISQU);\n";
-  OS << "}\n";
-  OS << "void ReplaceUses(SDNode *F, SDNode *T) DISABLE_INLINE {\n";
-  OS << "  unsigned FNumVals = F->getNumValues();\n";
-  OS << "  unsigned TNumVals = T->getNumValues();\n";
-  OS << "  ISelQueueUpdater ISQU(ISelQueue);\n";
-  OS << "  if (FNumVals != TNumVals) {\n";
-  OS << "    for (unsigned i = 0, e = std::min(FNumVals, TNumVals); "
-     << "i < e; ++i)\n";
-  OS << "      CurDAG->ReplaceAllUsesOfValueWith(SDOperand(F, i), "
-     << "SDOperand(T, i), &ISQU);\n";
-  OS << "  } else {\n";
-  OS << "    CurDAG->ReplaceAllUsesWith(F, T, &ISQU);\n";
-  OS << "  }\n";
-  OS << "  setSelected(F->getNodeId());\n";
-  OS << "  UpdateQueue(ISQU);\n";
-  OS << "}\n\n";
-
-  OS << "// SelectRoot - Top level entry to DAG isel.\n";
-  OS << "SDOperand SelectRoot(SDOperand Root) {\n";
-  OS << "  SelectRootInit();\n";
-  OS << "  unsigned NumBytes = (DAGSize + 7) / 8;\n";
-  OS << "  ISelQueued   = new unsigned char[NumBytes];\n";
-  OS << "  ISelSelected = new unsigned char[NumBytes];\n";
-  OS << "  memset(ISelQueued,   0, NumBytes);\n";
-  OS << "  memset(ISelSelected, 0, NumBytes);\n";
-  OS << "\n";
-  OS << "  // Create a dummy node (which is not added to allnodes), that adds\n"
-     << "  // a reference to the root node, preventing it from being deleted,\n"
-     << "  // and tracking any changes of the root.\n"
-     << "  HandleSDNode Dummy(CurDAG->getRoot());\n"
-     << "  ISelQueue.push_back(CurDAG->getRoot().Val);\n";
-  OS << "  while (!ISelQueue.empty()) {\n";
-  OS << "    SDNode *Node = ISelQueue.front();\n";
-  OS << "    std::pop_heap(ISelQueue.begin(), ISelQueue.end(), isel_sort());\n";
-  OS << "    ISelQueue.pop_back();\n";
-  OS << "    if (!isSelected(Node->getNodeId())) {\n";
-  OS << "      SDNode *ResNode = Select(SDOperand(Node, 0));\n";
-  OS << "      if (ResNode != Node) {\n";
-  OS << "        if (ResNode)\n";
-  OS << "          ReplaceUses(Node, ResNode);\n";
-  OS << "        if (Node->use_empty()) { // Don't delete EntryToken, etc.\n";
-  OS << "          ISelQueueUpdater ISQU(ISelQueue);\n";
-  OS << "          CurDAG->RemoveDeadNode(Node, &ISQU);\n";
-  OS << "          UpdateQueue(ISQU);\n";
-  OS << "        }\n";
-  OS << "      }\n";
-  OS << "    }\n";
-  OS << "  }\n";
-  OS << "\n";
-  OS << "  delete[] ISelQueued;\n";
-  OS << "  ISelQueued = NULL;\n";
-  OS << "  delete[] ISelSelected;\n";
-  OS << "  ISelSelected = NULL;\n";
-  OS << "  return Dummy.getValue();\n";
-  OS << "}\n";
+  OS << "// Include standard, target-independent definitions and methods used\n"
+     << "// by the instruction selector.\n";
+  OS << "#include <llvm/CodeGen/DAGISelHeader.h>\n\n";
   
   EmitNodeTransforms(OS);
   EmitPredicateFunctions(OS);