utils/TableGen/InstrInfoEmitter.cpp - fp2-dev/platform/external/llvm - Gitiles

 //===- InstrInfoEmitter.cpp - Generate a Instruction Set Desc. ------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This tablegen backend is responsible for emitting a description of the target
 // instruction set for the code generator.
 //
 //===----------------------------------------------------------------------===//

 #include "InstrInfoEmitter.h"
 #include "CodeGenTarget.h"
 #include "Record.h"
 #include <algorithm>
 #include <iostream>
 using namespace llvm;

 static void PrintDefList(const std::vector<Record*> &Uses,
                          unsigned Num, std::ostream &OS) {
   OS << "static const unsigned ImplicitList" << Num << "[] = { ";
   for (unsigned i = 0, e = Uses.size(); i != e; ++i)
     OS << getQualifiedName(Uses[i]) << ", ";
   OS << "0 };\n";
 }

 //===----------------------------------------------------------------------===//
 // Instruction Itinerary Information.
 //===----------------------------------------------------------------------===//

 struct RecordNameComparator {
   bool operator()(const Record *Rec1, const Record *Rec2) const {
     return Rec1->getName() < Rec2->getName();
   }
 };

 void InstrInfoEmitter::GatherItinClasses() {
   std::vector<Record*> DefList =
   Records.getAllDerivedDefinitions("InstrItinClass");
   std::sort(DefList.begin(), DefList.end(), RecordNameComparator());

   for (unsigned i = 0, N = DefList.size(); i < N; i++)
     ItinClassMap[DefList[i]->getName()] = i;
 }

 unsigned InstrInfoEmitter::getItinClassNumber(const Record *InstRec) {
   return ItinClassMap[InstRec->getValueAsDef("Itinerary")->getName()];
 }

 //===----------------------------------------------------------------------===//
 // Operand Info Emission.
 //===----------------------------------------------------------------------===//

 std::vector<std::string>
 InstrInfoEmitter::GetOperandInfo(const CodeGenInstruction &Inst) {
   std::vector<std::string> Result;

   for (unsigned i = 0, e = Inst.OperandList.size(); i != e; ++i) {
     // Handle aggregate operands and normal operands the same way by expanding
     // either case into a list of operands for this op.
     std::vector<CodeGenInstruction::OperandInfo> OperandList;

     // This might be a multiple operand thing.  Targets like X86 have
     // registers in their multi-operand operands.  It may also be an anonymous
     // operand, which has a single operand, but no declared class for the
     // operand.
     DagInit *MIOI = Inst.OperandList[i].MIOperandInfo;

     if (!MIOI || MIOI->getNumArgs() == 0) {
       // Single, anonymous, operand.
       OperandList.push_back(Inst.OperandList[i]);
     } else {
       for (unsigned j = 0, e = Inst.OperandList[i].MINumOperands; j != e; ++j) {
         OperandList.push_back(Inst.OperandList[i]);

         Record *OpR = dynamic_cast<DefInit*>(MIOI->getArg(j))->getDef();
         OperandList.back().Rec = OpR;
       }
     }

     for (unsigned j = 0, e = OperandList.size(); j != e; ++j) {
       Record *OpR = OperandList[j].Rec;
       std::string Res;

       if (OpR->isSubClassOf("RegisterClass"))
         Res += getQualifiedName(OpR) + "RegClassID, ";
       else
         Res += "0, ";
       // Fill in applicable flags.
       Res += "0";

       // Ptr value whose register class is resolved via callback.
       if (OpR->getName() == "ptr_rc")
         Res += "|M_LOOK_UP_PTR_REG_CLASS";

       // Predicate operands.  Check to see if the original unexpanded operand
       // was of type PredicateOperand.
       if (Inst.OperandList[i].Rec->isSubClassOf("PredicateOperand"))
         Res += "|M_PREDICATE_OPERAND";

       // Optional def operands.  Check to see if the original unexpanded operand
       // was of type OptionalDefOperand.
       if (Inst.OperandList[i].Rec->isSubClassOf("OptionalDefOperand"))
         Res += "|M_OPTIONAL_DEF_OPERAND";

       // Fill in constraint info.
       Res += ", " + Inst.OperandList[i].Constraints[j];
       Result.push_back(Res);
     }
   }

   return Result;
 }

 void InstrInfoEmitter::EmitOperandInfo(std::ostream &OS,
                                        OperandInfoMapTy &OperandInfoIDs) {
   // ID #0 is for no operand info.
   unsigned OperandListNum = 0;
   OperandInfoIDs[std::vector<std::string>()] = ++OperandListNum;

   OS << "\n";
   const CodeGenTarget &Target = CDP.getTargetInfo();
   for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
        E = Target.inst_end(); II != E; ++II) {
     std::vector<std::string> OperandInfo = GetOperandInfo(II->second);
     unsigned &N = OperandInfoIDs[OperandInfo];
     if (N != 0) continue;

     N = ++OperandListNum;
     OS << "static const TargetOperandInfo OperandInfo" << N << "[] = { ";
     for (unsigned i = 0, e = OperandInfo.size(); i != e; ++i)
       OS << "{ " << OperandInfo[i] << " }, ";
     OS << "};\n";
   }
 }

 //===----------------------------------------------------------------------===//
 // Instruction Analysis
 //===----------------------------------------------------------------------===//

 class InstAnalyzer {
   const CodeGenDAGPatterns &CDP;
   bool &isStore;
   bool &isLoad;
   bool &NeverHasSideEffects;
 public:
   InstAnalyzer(const CodeGenDAGPatterns &cdp,
                bool &isstore, bool &isload, bool &nhse)
     : CDP(cdp), isStore(isstore), isLoad(isload), NeverHasSideEffects(nhse) {
   }

   void Analyze(Record *InstRecord) {
     const TreePattern *Pattern = CDP.getInstruction(InstRecord).getPattern();
     if (Pattern == 0) return;  // No pattern.

     // Assume there is no side-effect unless we see one.
     // FIXME: Enable this.
     //NeverHasSideEffects = true;


     // FIXME: Assume only the first tree is the pattern. The others are clobber
     // nodes.
     AnalyzeNode(Pattern->getTree(0));
   }

 private:
   void AnalyzeNode(const TreePatternNode *N) {
     if (N->isLeaf()) {
       return;
     }

     if (N->getOperator()->getName() != "set") {
       // Get information about the SDNode for the operator.
       const SDNodeInfo &OpInfo = CDP.getSDNodeInfo(N->getOperator());

       if (OpInfo.getEnumName() == "ISD::STORE")
         isStore = true;
     }

     for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i)
       AnalyzeNode(N->getChild(i));
   }

 };

 void InstrInfoEmitter::InferFromPattern(const CodeGenInstruction &Inst,
                                         bool &isStore, bool &isLoad,
                                         bool &NeverHasSideEffects) {
   isStore             = Inst.isStore;
   isLoad              = Inst.isLoad;
   NeverHasSideEffects = Inst.neverHasSideEffects;

   InstAnalyzer(CDP, isStore, isLoad, NeverHasSideEffects).Analyze(Inst.TheDef);

   // If the .td file explicitly says there is no side effect, believe it.
   if (Inst.neverHasSideEffects)
     NeverHasSideEffects = true;
 }


 //===----------------------------------------------------------------------===//
 // Main Output.
 //===----------------------------------------------------------------------===//

 // run - Emit the main instruction description records for the target...
 void InstrInfoEmitter::run(std::ostream &OS) {
   GatherItinClasses();

   EmitSourceFileHeader("Target Instruction Descriptors", OS);
   OS << "namespace llvm {\n\n";

   CodeGenTarget Target;
   const std::string &TargetName = Target.getName();
   Record *InstrInfo = Target.getInstructionSet();

   // Keep track of all of the def lists we have emitted already.
   std::map<std::vector<Record*>, unsigned> EmittedLists;
   unsigned ListNumber = 0;

   // Emit all of the instruction's implicit uses and defs.
   for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
          E = Target.inst_end(); II != E; ++II) {
     Record *Inst = II->second.TheDef;
     std::vector<Record*> Uses = Inst->getValueAsListOfDefs("Uses");
     if (!Uses.empty()) {
       unsigned &IL = EmittedLists[Uses];
       if (!IL) PrintDefList(Uses, IL = ++ListNumber, OS);
     }
     std::vector<Record*> Defs = Inst->getValueAsListOfDefs("Defs");
     if (!Defs.empty()) {
       unsigned &IL = EmittedLists[Defs];
       if (!IL) PrintDefList(Defs, IL = ++ListNumber, OS);
     }
   }

   OperandInfoMapTy OperandInfoIDs;

   // Emit all of the operand info records.
   EmitOperandInfo(OS, OperandInfoIDs);

   // Emit all of the TargetInstrDescriptor records in their ENUM ordering.
   //
   OS << "\nstatic const TargetInstrDescriptor " << TargetName
      << "Insts[] = {\n";
   std::vector<const CodeGenInstruction*> NumberedInstructions;
   Target.getInstructionsByEnumValue(NumberedInstructions);

   for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i)
     emitRecord(*NumberedInstructions[i], i, InstrInfo, EmittedLists,
                OperandInfoIDs, OS);
   OS << "};\n";
   OS << "} // End llvm namespace \n";
 }

 void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,
                                   Record *InstrInfo,
                          std::map<std::vector<Record*>, unsigned> &EmittedLists,
                                   const OperandInfoMapTy &OpInfo,
                                   std::ostream &OS) {
   // Determine properties of the instruction from its pattern.
   bool isStore, isLoad, NeverHasSideEffects;
   InferFromPattern(Inst, isStore, isLoad, NeverHasSideEffects);

   if (NeverHasSideEffects && Inst.mayHaveSideEffects) {
     std::cerr << "error: Instruction '" << Inst.getName()
       << "' is marked with 'mayHaveSideEffects', but it can never have them!\n";
     exit(1);
   }

   int MinOperands = 0;
   if (!Inst.OperandList.empty())
     // Each logical operand can be multiple MI operands.
     MinOperands = Inst.OperandList.back().MIOperandNo +
                   Inst.OperandList.back().MINumOperands;

   OS << "  { ";
   OS << Num << ",\t" << MinOperands << ",\t"
      << Inst.NumDefs << ",\t\"" << Inst.getName();
   OS << "\",\t" << getItinClassNumber(Inst.TheDef) << ", 0";

   // Emit all of the target indepedent flags...
   if (Inst.isReturn)     OS << "|M_RET_FLAG";
   if (Inst.isBranch)     OS << "|M_BRANCH_FLAG";
   if (Inst.isIndirectBranch) OS << "|M_INDIRECT_FLAG";
   if (Inst.isBarrier)    OS << "|M_BARRIER_FLAG";
   if (Inst.hasDelaySlot) OS << "|M_DELAY_SLOT_FLAG";
   if (Inst.isCall)       OS << "|M_CALL_FLAG";
   if (isLoad)            OS << "|M_LOAD_FLAG";
   if (isStore)           OS << "|M_STORE_FLAG";
   if (Inst.isImplicitDef)OS << "|M_IMPLICIT_DEF_FLAG";
   if (Inst.isPredicable) OS << "|M_PREDICABLE";
   if (Inst.isConvertibleToThreeAddress) OS << "|M_CONVERTIBLE_TO_3_ADDR";
   if (Inst.isCommutable) OS << "|M_COMMUTABLE";
   if (Inst.isTerminator) OS << "|M_TERMINATOR_FLAG";
   if (Inst.isReMaterializable) OS << "|M_REMATERIALIZIBLE";
   if (Inst.isNotDuplicable)    OS << "|M_NOT_DUPLICABLE";
   if (Inst.hasOptionalDef)     OS << "|M_HAS_OPTIONAL_DEF";
   if (Inst.usesCustomDAGSchedInserter)
     OS << "|M_USES_CUSTOM_DAG_SCHED_INSERTION";
   if (Inst.hasVariableNumberOfOperands) OS << "|M_VARIABLE_OPS";
   if (Inst.mayHaveSideEffects)          OS << "|M_MAY_HAVE_SIDE_EFFECTS";
   if (NeverHasSideEffects)              OS << "|M_NEVER_HAS_SIDE_EFFECTS";
   OS << ", 0";

   // Emit all of the target-specific flags...
   ListInit *LI    = InstrInfo->getValueAsListInit("TSFlagsFields");
   ListInit *Shift = InstrInfo->getValueAsListInit("TSFlagsShifts");
   if (LI->getSize() != Shift->getSize())
     throw "Lengths of " + InstrInfo->getName() +
           ":(TargetInfoFields, TargetInfoPositions) must be equal!";

   for (unsigned i = 0, e = LI->getSize(); i != e; ++i)
     emitShiftedValue(Inst.TheDef, dynamic_cast<StringInit*>(LI->getElement(i)),
                      dynamic_cast<IntInit*>(Shift->getElement(i)), OS);

   OS << ", ";

   // Emit the implicit uses and defs lists...
   std::vector<Record*> UseList = Inst.TheDef->getValueAsListOfDefs("Uses");
   if (UseList.empty())
     OS << "NULL, ";
   else
     OS << "ImplicitList" << EmittedLists[UseList] << ", ";

   std::vector<Record*> DefList = Inst.TheDef->getValueAsListOfDefs("Defs");
   if (DefList.empty())
     OS << "NULL, ";
   else
     OS << "ImplicitList" << EmittedLists[DefList] << ", ";

   // Emit the operand info.
   std::vector<std::string> OperandInfo = GetOperandInfo(Inst);
   if (OperandInfo.empty())
     OS << "0";
   else
     OS << "OperandInfo" << OpInfo.find(OperandInfo)->second;

   OS << " },  // Inst #" << Num << " = " << Inst.TheDef->getName() << "\n";
 }


 void InstrInfoEmitter::emitShiftedValue(Record *R, StringInit *Val,
                                         IntInit *ShiftInt, std::ostream &OS) {
   if (Val == 0 || ShiftInt == 0)
     throw std::string("Illegal value or shift amount in TargetInfo*!");
   RecordVal *RV = R->getValue(Val->getValue());
   int Shift = ShiftInt->getValue();

   if (RV == 0 || RV->getValue() == 0) {
     // This isn't an error if this is a builtin instruction.
     if (R->getName() != "PHI" &&
         R->getName() != "INLINEASM" &&
         R->getName() != "LABEL" &&
         R->getName() != "EXTRACT_SUBREG" &&
         R->getName() != "INSERT_SUBREG")
       throw R->getName() + " doesn't have a field named '" +
             Val->getValue() + "'!";
     return;
   }

   Init *Value = RV->getValue();
   if (BitInit *BI = dynamic_cast<BitInit*>(Value)) {
     if (BI->getValue()) OS << "|(1<<" << Shift << ")";
     return;
   } else if (BitsInit *BI = dynamic_cast<BitsInit*>(Value)) {
     // Convert the Bits to an integer to print...
     Init *I = BI->convertInitializerTo(new IntRecTy());
     if (I)
       if (IntInit *II = dynamic_cast<IntInit*>(I)) {
         if (II->getValue()) {
           if (Shift)
             OS << "|(" << II->getValue() << "<<" << Shift << ")";
           else
             OS << "|" << II->getValue();
         }
         return;
       }

   } else if (IntInit *II = dynamic_cast<IntInit*>(Value)) {
     if (II->getValue()) {
       if (Shift)
         OS << "|(" << II->getValue() << "<<" << Shift << ")";
       else
         OS << II->getValue();
     }
     return;
   }

   std::cerr << "Unhandled initializer: " << *Val << "\n";
   throw "In record '" + R->getName() + "' for TSFlag emission.";
 }
	//===- InstrInfoEmitter.cpp - Generate a Instruction Set Desc. ------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This tablegen backend is responsible for emitting a description of the target
	// instruction set for the code generator.
	//
	//===----------------------------------------------------------------------===//

	#include "InstrInfoEmitter.h"
	#include "CodeGenTarget.h"
	#include "Record.h"
	#include <algorithm>
	#include <iostream>
	using namespace llvm;

	static void PrintDefList(const std::vector<Record*> &Uses,
	unsigned Num, std::ostream &OS) {
	OS << "static const unsigned ImplicitList" << Num << "[] = { ";
	for (unsigned i = 0, e = Uses.size(); i != e; ++i)
	OS << getQualifiedName(Uses[i]) << ", ";
	OS << "0 };\n";
	}

	//===----------------------------------------------------------------------===//
	// Instruction Itinerary Information.
	//===----------------------------------------------------------------------===//

	struct RecordNameComparator {
	bool operator()(const Record Rec1, const Record Rec2) const {
	return Rec1->getName() < Rec2->getName();
	}
	};

	void InstrInfoEmitter::GatherItinClasses() {
	std::vector<Record*> DefList =
	Records.getAllDerivedDefinitions("InstrItinClass");
	std::sort(DefList.begin(), DefList.end(), RecordNameComparator());

	for (unsigned i = 0, N = DefList.size(); i < N; i++)
	ItinClassMap[DefList[i]->getName()] = i;
	}

	unsigned InstrInfoEmitter::getItinClassNumber(const Record *InstRec) {
	return ItinClassMap[InstRec->getValueAsDef("Itinerary")->getName()];
	}

	//===----------------------------------------------------------------------===//
	// Operand Info Emission.
	//===----------------------------------------------------------------------===//

	std::vector<std::string>
	InstrInfoEmitter::GetOperandInfo(const CodeGenInstruction &Inst) {
	std::vector<std::string> Result;

	for (unsigned i = 0, e = Inst.OperandList.size(); i != e; ++i) {
	// Handle aggregate operands and normal operands the same way by expanding
	// either case into a list of operands for this op.
	std::vector<CodeGenInstruction::OperandInfo> OperandList;

	// This might be a multiple operand thing. Targets like X86 have
	// registers in their multi-operand operands. It may also be an anonymous
	// operand, which has a single operand, but no declared class for the
	// operand.
	DagInit *MIOI = Inst.OperandList[i].MIOperandInfo;

	if (!MIOI \|\| MIOI->getNumArgs() == 0) {
	// Single, anonymous, operand.
	OperandList.push_back(Inst.OperandList[i]);
	} else {
	for (unsigned j = 0, e = Inst.OperandList[i].MINumOperands; j != e; ++j) {
	OperandList.push_back(Inst.OperandList[i]);

	Record OpR = dynamic_cast<DefInit>(MIOI->getArg(j))->getDef();
	OperandList.back().Rec = OpR;
	}
	}

	for (unsigned j = 0, e = OperandList.size(); j != e; ++j) {
	Record *OpR = OperandList[j].Rec;
	std::string Res;

	if (OpR->isSubClassOf("RegisterClass"))
	Res += getQualifiedName(OpR) + "RegClassID, ";
	else
	Res += "0, ";
	// Fill in applicable flags.
	Res += "0";

	// Ptr value whose register class is resolved via callback.
	if (OpR->getName() == "ptr_rc")
	Res += "\|M_LOOK_UP_PTR_REG_CLASS";

	// Predicate operands. Check to see if the original unexpanded operand
	// was of type PredicateOperand.
	if (Inst.OperandList[i].Rec->isSubClassOf("PredicateOperand"))
	Res += "\|M_PREDICATE_OPERAND";

	// Optional def operands. Check to see if the original unexpanded operand
	// was of type OptionalDefOperand.
	if (Inst.OperandList[i].Rec->isSubClassOf("OptionalDefOperand"))
	Res += "\|M_OPTIONAL_DEF_OPERAND";

	// Fill in constraint info.
	Res += ", " + Inst.OperandList[i].Constraints[j];
	Result.push_back(Res);
	}
	}

	return Result;
	}

	void InstrInfoEmitter::EmitOperandInfo(std::ostream &OS,
	OperandInfoMapTy &OperandInfoIDs) {
	// ID #0 is for no operand info.
	unsigned OperandListNum = 0;
	OperandInfoIDs[std::vector<std::string>()] = ++OperandListNum;

	OS << "\n";
	const CodeGenTarget &Target = CDP.getTargetInfo();
	for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
	E = Target.inst_end(); II != E; ++II) {
	std::vector<std::string> OperandInfo = GetOperandInfo(II->second);
	unsigned &N = OperandInfoIDs[OperandInfo];
	if (N != 0) continue;

	N = ++OperandListNum;
	OS << "static const TargetOperandInfo OperandInfo" << N << "[] = { ";
	for (unsigned i = 0, e = OperandInfo.size(); i != e; ++i)
	OS << "{ " << OperandInfo[i] << " }, ";
	OS << "};\n";
	}
	}

	//===----------------------------------------------------------------------===//
	// Instruction Analysis
	//===----------------------------------------------------------------------===//

	class InstAnalyzer {
	const CodeGenDAGPatterns &CDP;
	bool &isStore;
	bool &isLoad;
	bool &NeverHasSideEffects;
	public:
	InstAnalyzer(const CodeGenDAGPatterns &cdp,
	bool &isstore, bool &isload, bool &nhse)
	: CDP(cdp), isStore(isstore), isLoad(isload), NeverHasSideEffects(nhse) {
	}

	void Analyze(Record *InstRecord) {
	const TreePattern *Pattern = CDP.getInstruction(InstRecord).getPattern();
	if (Pattern == 0) return; // No pattern.

	// Assume there is no side-effect unless we see one.
	// FIXME: Enable this.
	//NeverHasSideEffects = true;


	// FIXME: Assume only the first tree is the pattern. The others are clobber
	// nodes.
	AnalyzeNode(Pattern->getTree(0));
	}

	private:
	void AnalyzeNode(const TreePatternNode *N) {
	if (N->isLeaf()) {
	return;
	}

	if (N->getOperator()->getName() != "set") {
	// Get information about the SDNode for the operator.
	const SDNodeInfo &OpInfo = CDP.getSDNodeInfo(N->getOperator());

	if (OpInfo.getEnumName() == "ISD::STORE")
	isStore = true;
	}

	for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i)
	AnalyzeNode(N->getChild(i));
	}

	};

	void InstrInfoEmitter::InferFromPattern(const CodeGenInstruction &Inst,
	bool &isStore, bool &isLoad,
	bool &NeverHasSideEffects) {
	isStore = Inst.isStore;
	isLoad = Inst.isLoad;
	NeverHasSideEffects = Inst.neverHasSideEffects;

	InstAnalyzer(CDP, isStore, isLoad, NeverHasSideEffects).Analyze(Inst.TheDef);

	// If the .td file explicitly says there is no side effect, believe it.
	if (Inst.neverHasSideEffects)
	NeverHasSideEffects = true;
	}


	//===----------------------------------------------------------------------===//
	// Main Output.
	//===----------------------------------------------------------------------===//

	// run - Emit the main instruction description records for the target...
	void InstrInfoEmitter::run(std::ostream &OS) {
	GatherItinClasses();

	EmitSourceFileHeader("Target Instruction Descriptors", OS);
	OS << "namespace llvm {\n\n";

	CodeGenTarget Target;
	const std::string &TargetName = Target.getName();
	Record *InstrInfo = Target.getInstructionSet();

	// Keep track of all of the def lists we have emitted already.
	std::map<std::vector<Record*>, unsigned> EmittedLists;
	unsigned ListNumber = 0;

	// Emit all of the instruction's implicit uses and defs.
	for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
	E = Target.inst_end(); II != E; ++II) {
	Record *Inst = II->second.TheDef;
	std::vector<Record*> Uses = Inst->getValueAsListOfDefs("Uses");
	if (!Uses.empty()) {
	unsigned &IL = EmittedLists[Uses];
	if (!IL) PrintDefList(Uses, IL = ++ListNumber, OS);
	}
	std::vector<Record*> Defs = Inst->getValueAsListOfDefs("Defs");
	if (!Defs.empty()) {
	unsigned &IL = EmittedLists[Defs];
	if (!IL) PrintDefList(Defs, IL = ++ListNumber, OS);
	}
	}

	OperandInfoMapTy OperandInfoIDs;

	// Emit all of the operand info records.
	EmitOperandInfo(OS, OperandInfoIDs);

	// Emit all of the TargetInstrDescriptor records in their ENUM ordering.
	//
	OS << "\nstatic const TargetInstrDescriptor " << TargetName
	<< "Insts[] = {\n";
	std::vector<const CodeGenInstruction*> NumberedInstructions;
	Target.getInstructionsByEnumValue(NumberedInstructions);

	for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i)
	emitRecord(*NumberedInstructions[i], i, InstrInfo, EmittedLists,
	OperandInfoIDs, OS);
	OS << "};\n";
	OS << "} // End llvm namespace \n";
	}

	void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,
	Record *InstrInfo,
	std::map<std::vector<Record*>, unsigned> &EmittedLists,
	const OperandInfoMapTy &OpInfo,
	std::ostream &OS) {
	// Determine properties of the instruction from its pattern.
	bool isStore, isLoad, NeverHasSideEffects;
	InferFromPattern(Inst, isStore, isLoad, NeverHasSideEffects);

	if (NeverHasSideEffects && Inst.mayHaveSideEffects) {
	std::cerr << "error: Instruction '" << Inst.getName()
	<< "' is marked with 'mayHaveSideEffects', but it can never have them!\n";
	exit(1);
	}

	int MinOperands = 0;
	if (!Inst.OperandList.empty())
	// Each logical operand can be multiple MI operands.
	MinOperands = Inst.OperandList.back().MIOperandNo +
	Inst.OperandList.back().MINumOperands;

	OS << " { ";
	OS << Num << ",\t" << MinOperands << ",\t"
	<< Inst.NumDefs << ",\t\"" << Inst.getName();
	OS << "\",\t" << getItinClassNumber(Inst.TheDef) << ", 0";

	// Emit all of the target indepedent flags...
	if (Inst.isReturn) OS << "\|M_RET_FLAG";
	if (Inst.isBranch) OS << "\|M_BRANCH_FLAG";
	if (Inst.isIndirectBranch) OS << "\|M_INDIRECT_FLAG";
	if (Inst.isBarrier) OS << "\|M_BARRIER_FLAG";
	if (Inst.hasDelaySlot) OS << "\|M_DELAY_SLOT_FLAG";
	if (Inst.isCall) OS << "\|M_CALL_FLAG";
	if (isLoad) OS << "\|M_LOAD_FLAG";
	if (isStore) OS << "\|M_STORE_FLAG";
	if (Inst.isImplicitDef)OS << "\|M_IMPLICIT_DEF_FLAG";
	if (Inst.isPredicable) OS << "\|M_PREDICABLE";
	if (Inst.isConvertibleToThreeAddress) OS << "\|M_CONVERTIBLE_TO_3_ADDR";
	if (Inst.isCommutable) OS << "\|M_COMMUTABLE";
	if (Inst.isTerminator) OS << "\|M_TERMINATOR_FLAG";
	if (Inst.isReMaterializable) OS << "\|M_REMATERIALIZIBLE";
	if (Inst.isNotDuplicable) OS << "\|M_NOT_DUPLICABLE";
	if (Inst.hasOptionalDef) OS << "\|M_HAS_OPTIONAL_DEF";
	if (Inst.usesCustomDAGSchedInserter)
	OS << "\|M_USES_CUSTOM_DAG_SCHED_INSERTION";
	if (Inst.hasVariableNumberOfOperands) OS << "\|M_VARIABLE_OPS";
	if (Inst.mayHaveSideEffects) OS << "\|M_MAY_HAVE_SIDE_EFFECTS";
	if (NeverHasSideEffects) OS << "\|M_NEVER_HAS_SIDE_EFFECTS";
	OS << ", 0";

	// Emit all of the target-specific flags...
	ListInit *LI = InstrInfo->getValueAsListInit("TSFlagsFields");
	ListInit *Shift = InstrInfo->getValueAsListInit("TSFlagsShifts");
	if (LI->getSize() != Shift->getSize())
	throw "Lengths of " + InstrInfo->getName() +
	":(TargetInfoFields, TargetInfoPositions) must be equal!";

	for (unsigned i = 0, e = LI->getSize(); i != e; ++i)
	emitShiftedValue(Inst.TheDef, dynamic_cast<StringInit*>(LI->getElement(i)),
	dynamic_cast<IntInit*>(Shift->getElement(i)), OS);

	OS << ", ";

	// Emit the implicit uses and defs lists...
	std::vector<Record*> UseList = Inst.TheDef->getValueAsListOfDefs("Uses");
	if (UseList.empty())
	OS << "NULL, ";
	else
	OS << "ImplicitList" << EmittedLists[UseList] << ", ";

	std::vector<Record*> DefList = Inst.TheDef->getValueAsListOfDefs("Defs");
	if (DefList.empty())
	OS << "NULL, ";
	else
	OS << "ImplicitList" << EmittedLists[DefList] << ", ";

	// Emit the operand info.
	std::vector<std::string> OperandInfo = GetOperandInfo(Inst);
	if (OperandInfo.empty())
	OS << "0";
	else
	OS << "OperandInfo" << OpInfo.find(OperandInfo)->second;

	OS << " }, // Inst #" << Num << " = " << Inst.TheDef->getName() << "\n";
	}


	void InstrInfoEmitter::emitShiftedValue(Record R, StringInit Val,
	IntInit *ShiftInt, std::ostream &OS) {
	if (Val == 0 \|\| ShiftInt == 0)
	throw std::string("Illegal value or shift amount in TargetInfo*!");
	RecordVal *RV = R->getValue(Val->getValue());
	int Shift = ShiftInt->getValue();

	if (RV == 0 \|\| RV->getValue() == 0) {
	// This isn't an error if this is a builtin instruction.
	if (R->getName() != "PHI" &&
	R->getName() != "INLINEASM" &&
	R->getName() != "LABEL" &&
	R->getName() != "EXTRACT_SUBREG" &&
	R->getName() != "INSERT_SUBREG")
	throw R->getName() + " doesn't have a field named '" +
	Val->getValue() + "'!";
	return;
	}

	Init *Value = RV->getValue();
	if (BitInit BI = dynamic_cast<BitInit>(Value)) {
	if (BI->getValue()) OS << "\|(1<<" << Shift << ")";
	return;
	} else if (BitsInit BI = dynamic_cast<BitsInit>(Value)) {
	// Convert the Bits to an integer to print...
	Init *I = BI->convertInitializerTo(new IntRecTy());
	if (I)
	if (IntInit II = dynamic_cast<IntInit>(I)) {
	if (II->getValue()) {
	if (Shift)
	OS << "\|(" << II->getValue() << "<<" << Shift << ")";
	else
	OS << "\|" << II->getValue();
	}
	return;
	}

	} else if (IntInit II = dynamic_cast<IntInit>(Value)) {
	if (II->getValue()) {
	if (Shift)
	OS << "\|(" << II->getValue() << "<<" << Shift << ")";
	else
	OS << II->getValue();
	}
	return;
	}

	std::cerr << "Unhandled initializer: " << *Val << "\n";
	throw "In record '" + R->getName() + "' for TSFlag emission.";
	}