llvm/utils/TableGen/InstrInfoEmitter.cpp - llvm-project - Git at Google

 //===- InstrInfoEmitter.cpp - Generate a Instruction Set Desc. ------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file was developed by the LLVM research group and 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>
 using namespace llvm;

 // runEnums - Print out enum values for all of the instructions.
 void InstrInfoEmitter::runEnums(std::ostream &OS) {
   EmitSourceFileHeader("Target Instruction Enum Values", OS);
   OS << "namespace llvm {\n\n";

   CodeGenTarget Target;

   // We must emit the PHI opcode first...
   Record *InstrInfo = Target.getInstructionSet();

   std::string Namespace = Target.inst_begin()->second.Namespace;

   if (!Namespace.empty())
     OS << "namespace " << Namespace << " {\n";
   OS << "  enum {\n";

   std::vector<const CodeGenInstruction*> NumberedInstructions;
   Target.getInstructionsByEnumValue(NumberedInstructions);

   for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) {
     OS << "    " << NumberedInstructions[i]->TheDef->getName()
        << ", \t// " << i << "\n";
   }
   OS << "    INSTRUCTION_LIST_END\n";
   OS << "  };\n";
   if (!Namespace.empty())
     OS << "}\n";
   OS << "} // End llvm namespace \n";
 }

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

 static std::vector<Record*> GetOperandInfo(const CodeGenInstruction &Inst) {
   std::vector<Record*> Result;
   if (Inst.hasVariableNumberOfOperands)
     return Result;  // No info for variable operand instrs.

   for (unsigned i = 0, e = Inst.OperandList.size(); i != e; ++i) {
     if (Inst.OperandList[i].Rec->isSubClassOf("RegisterClass")) {
       Result.push_back(Inst.OperandList[i].Rec);
     } else {
       // This might be a multiple operand thing.
       // Targets like X86 have registers in their multi-operand operands.
       DagInit *MIOI = Inst.OperandList[i].MIOperandInfo;
       unsigned NumDefs = MIOI->getNumArgs();
       for (unsigned j = 0, e = Inst.OperandList[i].MINumOperands; j != e; ++j) {
         if (NumDefs <= j) {
           Result.push_back(0);
         } else {
           DefInit *Def = dynamic_cast<DefInit*>(MIOI->getArg(j));
           Result.push_back(Def ? Def->getDef() : 0);
         }
       }
     }
   }
   return Result;
 }


 // 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();

   // Emit empty implicit uses and defs lists
   OS << "static const unsigned EmptyImpList[] = { 0 };\n";

   // 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);
     }
   }

   std::map<std::vector<Record*>, unsigned> OperandInfosEmitted;
   unsigned OperandListNum = 0;
   OperandInfosEmitted[std::vector<Record*>()] = ++OperandListNum;

   // Emit all of the operand info records.
   OS << "\n";
   for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
        E = Target.inst_end(); II != E; ++II) {
     std::vector<Record*> OperandInfo = GetOperandInfo(II->second);
     unsigned &N = OperandInfosEmitted[OperandInfo];
     if (N == 0) {
       N = ++OperandListNum;
       OS << "static const TargetOperandInfo OperandInfo" << N << "[] = { ";
       for (unsigned i = 0, e = OperandInfo.size(); i != e; ++i) {
         Record *RC = OperandInfo[i];
         // FIXME: We only care about register operands for now.
         if (RC && RC->isSubClassOf("RegisterClass")) {
           OS << "{ &" << getQualifiedName(RC) << "RegClass }, ";
         } else {
           OS << "{ 0 }, ";
         }
       }
       OS << "};\n";
     }
   }

   // 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,
                OperandInfosEmitted, 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,
                                std::map<std::vector<Record*>, unsigned> &OpInfo,
                                   std::ostream &OS) {
   int NumOperands;
   if (Inst.hasVariableNumberOfOperands)
     NumOperands = -1;
   else if (!Inst.OperandList.empty())
     // Each logical operand can be multiple MI operands.
     NumOperands = Inst.OperandList.back().MIOperandNo +
                   Inst.OperandList.back().MINumOperands;
   else
     NumOperands = 0;

   OS << "  { \"";
   if (Inst.Name.empty())
     OS << Inst.TheDef->getName();
   else
     OS << Inst.Name;

   unsigned ItinClass = !IsItineraries ? 0 :
             ItinClassNumber(Inst.TheDef->getValueAsDef("Itinerary")->getName());

   OS << "\",\t" << NumOperands << ", -1, 0, false, 0, 0, "
      << ItinClass
      << ", 0";

   // Emit all of the target indepedent flags...
   if (Inst.isReturn)     OS << "|M_RET_FLAG";
   if (Inst.isBranch)     OS << "|M_BRANCH_FLAG";
   if (Inst.isBarrier)    OS << "|M_BARRIER_FLAG";
   if (Inst.hasDelaySlot) OS << "|M_DELAY_SLOT_FLAG";
   if (Inst.isCall)       OS << "|M_CALL_FLAG";
   if (Inst.isLoad)       OS << "|M_LOAD_FLAG";
   if (Inst.isStore)      OS << "|M_STORE_FLAG";
   if (Inst.isTwoAddress) OS << "|M_2_ADDR_FLAG";
   if (Inst.isConvertibleToThreeAddress) OS << "|M_CONVERTIBLE_TO_3_ADDR";
   if (Inst.isCommutable) OS << "|M_COMMUTABLE";
   if (Inst.isTerminator) OS << "|M_TERMINATOR_FLAG";
   if (Inst.usesCustomDAGSchedInserter)
     OS << "|M_USES_CUSTOM_DAG_SCHED_INSERTION";
   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 << "EmptyImpList, ";
   else
     OS << "ImplicitList" << EmittedLists[UseList] << ", ";

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

   // Emit the operand info.
   std::vector<Record*> OperandInfo = GetOperandInfo(Inst);
   if (OperandInfo.empty())
     OS << "0";
   else
     OS << "OperandInfo" << OpInfo[OperandInfo];

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

 struct LessRecord {
   bool operator()(const Record *Rec1, const Record *Rec2) const {
     return Rec1->getName() < Rec2->getName();
   }
 };
 void InstrInfoEmitter::GatherItinClasses() {
   std::vector<Record*> DefList =
                           Records.getAllDerivedDefinitions("InstrItinClass");
   IsItineraries = !DefList.empty();

   if (!IsItineraries) return;

   std::sort(DefList.begin(), DefList.end(), LessRecord());

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

 unsigned InstrInfoEmitter::ItinClassNumber(std::string ItinName) {
   return ItinClassMap[ItinName];
 }

 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")
       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 was developed by the LLVM research group and 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>
	using namespace llvm;

	// runEnums - Print out enum values for all of the instructions.
	void InstrInfoEmitter::runEnums(std::ostream &OS) {
	EmitSourceFileHeader("Target Instruction Enum Values", OS);
	OS << "namespace llvm {\n\n";

	CodeGenTarget Target;

	// We must emit the PHI opcode first...
	Record *InstrInfo = Target.getInstructionSet();

	std::string Namespace = Target.inst_begin()->second.Namespace;

	if (!Namespace.empty())
	OS << "namespace " << Namespace << " {\n";
	OS << " enum {\n";

	std::vector<const CodeGenInstruction*> NumberedInstructions;
	Target.getInstructionsByEnumValue(NumberedInstructions);

	for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) {
	OS << " " << NumberedInstructions[i]->TheDef->getName()
	<< ", \t// " << i << "\n";
	}
	OS << " INSTRUCTION_LIST_END\n";
	OS << " };\n";
	if (!Namespace.empty())
	OS << "}\n";
	OS << "} // End llvm namespace \n";
	}

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

	static std::vector<Record*> GetOperandInfo(const CodeGenInstruction &Inst) {
	std::vector<Record*> Result;
	if (Inst.hasVariableNumberOfOperands)
	return Result; // No info for variable operand instrs.

	for (unsigned i = 0, e = Inst.OperandList.size(); i != e; ++i) {
	if (Inst.OperandList[i].Rec->isSubClassOf("RegisterClass")) {
	Result.push_back(Inst.OperandList[i].Rec);
	} else {
	// This might be a multiple operand thing.
	// Targets like X86 have registers in their multi-operand operands.
	DagInit *MIOI = Inst.OperandList[i].MIOperandInfo;
	unsigned NumDefs = MIOI->getNumArgs();
	for (unsigned j = 0, e = Inst.OperandList[i].MINumOperands; j != e; ++j) {
	if (NumDefs <= j) {
	Result.push_back(0);
	} else {
	DefInit Def = dynamic_cast<DefInit>(MIOI->getArg(j));
	Result.push_back(Def ? Def->getDef() : 0);
	}
	}
	}
	}
	return Result;
	}


	// 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();

	// Emit empty implicit uses and defs lists
	OS << "static const unsigned EmptyImpList[] = { 0 };\n";

	// 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);
	}
	}

	std::map<std::vector<Record*>, unsigned> OperandInfosEmitted;
	unsigned OperandListNum = 0;
	OperandInfosEmitted[std::vector<Record*>()] = ++OperandListNum;

	// Emit all of the operand info records.
	OS << "\n";
	for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
	E = Target.inst_end(); II != E; ++II) {
	std::vector<Record*> OperandInfo = GetOperandInfo(II->second);
	unsigned &N = OperandInfosEmitted[OperandInfo];
	if (N == 0) {
	N = ++OperandListNum;
	OS << "static const TargetOperandInfo OperandInfo" << N << "[] = { ";
	for (unsigned i = 0, e = OperandInfo.size(); i != e; ++i) {
	Record *RC = OperandInfo[i];
	// FIXME: We only care about register operands for now.
	if (RC && RC->isSubClassOf("RegisterClass")) {
	OS << "{ &" << getQualifiedName(RC) << "RegClass }, ";
	} else {
	OS << "{ 0 }, ";
	}
	}
	OS << "};\n";
	}
	}

	// 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,
	OperandInfosEmitted, 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,
	std::map<std::vector<Record*>, unsigned> &OpInfo,
	std::ostream &OS) {
	int NumOperands;
	if (Inst.hasVariableNumberOfOperands)
	NumOperands = -1;
	else if (!Inst.OperandList.empty())
	// Each logical operand can be multiple MI operands.
	NumOperands = Inst.OperandList.back().MIOperandNo +
	Inst.OperandList.back().MINumOperands;
	else
	NumOperands = 0;

	OS << " { \"";
	if (Inst.Name.empty())
	OS << Inst.TheDef->getName();
	else
	OS << Inst.Name;

	unsigned ItinClass = !IsItineraries ? 0 :
	ItinClassNumber(Inst.TheDef->getValueAsDef("Itinerary")->getName());

	OS << "\",\t" << NumOperands << ", -1, 0, false, 0, 0, "
	<< ItinClass
	<< ", 0";

	// Emit all of the target indepedent flags...
	if (Inst.isReturn) OS << "\|M_RET_FLAG";
	if (Inst.isBranch) OS << "\|M_BRANCH_FLAG";
	if (Inst.isBarrier) OS << "\|M_BARRIER_FLAG";
	if (Inst.hasDelaySlot) OS << "\|M_DELAY_SLOT_FLAG";
	if (Inst.isCall) OS << "\|M_CALL_FLAG";
	if (Inst.isLoad) OS << "\|M_LOAD_FLAG";
	if (Inst.isStore) OS << "\|M_STORE_FLAG";
	if (Inst.isTwoAddress) OS << "\|M_2_ADDR_FLAG";
	if (Inst.isConvertibleToThreeAddress) OS << "\|M_CONVERTIBLE_TO_3_ADDR";
	if (Inst.isCommutable) OS << "\|M_COMMUTABLE";
	if (Inst.isTerminator) OS << "\|M_TERMINATOR_FLAG";
	if (Inst.usesCustomDAGSchedInserter)
	OS << "\|M_USES_CUSTOM_DAG_SCHED_INSERTION";
	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 << "EmptyImpList, ";
	else
	OS << "ImplicitList" << EmittedLists[UseList] << ", ";

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

	// Emit the operand info.
	std::vector<Record*> OperandInfo = GetOperandInfo(Inst);
	if (OperandInfo.empty())
	OS << "0";
	else
	OS << "OperandInfo" << OpInfo[OperandInfo];

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

	struct LessRecord {
	bool operator()(const Record Rec1, const Record Rec2) const {
	return Rec1->getName() < Rec2->getName();
	}
	};
	void InstrInfoEmitter::GatherItinClasses() {
	std::vector<Record*> DefList =
	Records.getAllDerivedDefinitions("InstrItinClass");
	IsItineraries = !DefList.empty();

	if (!IsItineraries) return;

	std::sort(DefList.begin(), DefList.end(), LessRecord());

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

	unsigned InstrInfoEmitter::ItinClassNumber(std::string ItinName) {
	return ItinClassMap[ItinName];
	}

	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")
	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.";
	}