Rewrite the tblgen parser in a recursive descent style, eliminating the bison parser.

This makes the parser much easier to understand, eliminates a ton of global variables,
and gives tblgen nice caret diagnostics.  It is also faster, but tblgen probably doesn't
care about performance.

There are a couple of FIXMEs which I will take care of next.

llvm-svn: 44274

1 files changed, 0 insertions, 806 deletions

diff --git a/llvm/utils/TableGen/FileParser.y.cvs b/llvm/utils/TableGen/FileParser.y.cvs
deleted file mode 100644
index 0612f56ca01..00000000000
--- a/llvm/utils/TableGen/FileParser.y.cvs
+++ /dev/null
@@ -1,806 +0,0 @@
-//===-- FileParser.y - Parser for TableGen files ----------------*- C++ -*-===//
-// 
-//                     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 file implements the bison parser for Table Generator files...
-//
-//===----------------------------------------------------------------------===//
-
-%{
-#include "Record.h"
-#include "llvm/ADT/StringExtras.h"
-#include "llvm/Support/Streams.h"
-#include <algorithm>
-#include <cstdio>
-#define YYERROR_VERBOSE 1
-
-int yyerror(const char *ErrorMsg);
-int yylex();
-
-namespace llvm {
-  struct MultiClass {
-    Record Rec;  // Placeholder for template args and Name.
-    std::vector<Record*> DefPrototypes;
-    
-    MultiClass(const std::string &Name) : Rec(Name) {}
-  };
-
-  
-static std::map<std::string, MultiClass*> MultiClasses;
-  
-extern int Filelineno;
-static MultiClass *CurMultiClass = 0;    // Set while parsing a multiclass.
-static std::string *CurDefmPrefix = 0;   // Set while parsing defm.
-static Record *CurRec = 0;
-static bool ParsingTemplateArgs = false;
-
-typedef std::pair<Record*, std::vector<Init*>*> SubClassRefTy;
-
-struct LetRecord {
-  std::string Name;
-  std::vector<unsigned> Bits;
-  Init *Value;
-  bool HasBits;
-  LetRecord(const std::string &N, std::vector<unsigned> *B, Init *V)
-    : Name(N), Value(V), HasBits(B != 0) {
-    if (HasBits) Bits = *B;
-  }
-};
-
-static std::vector<std::vector<LetRecord> > LetStack;
-
-
-extern std::ostream &err();
-
-/// getActiveRec - If inside a def/class definition, return the def/class.
-/// Otherwise, if within a multidef, return it.
-static Record *getActiveRec() {
-  return CurRec ? CurRec : &CurMultiClass->Rec;
-}
-
-static void addValue(const RecordVal &RV) {
-  Record *TheRec = getActiveRec();
-  
-  if (RecordVal *ERV = TheRec->getValue(RV.getName())) {
-    // The value already exists in the class, treat this as a set...
-    if (ERV->setValue(RV.getValue())) {
-      err() << "New definition of '" << RV.getName() << "' of type '"
-            << *RV.getType() << "' is incompatible with previous "
-            << "definition of type '" << *ERV->getType() << "'!\n";
-      exit(1);
-    }
-  } else {
-    TheRec->addValue(RV);
-  }
-}
-
-static void addSuperClass(Record *SC) {
-  if (CurRec->isSubClassOf(SC)) {
-    err() << "Already subclass of '" << SC->getName() << "'!\n";
-    exit(1);
-  }
-  CurRec->addSuperClass(SC);
-}
-
-static void setValue(const std::string &ValName, 
-                     std::vector<unsigned> *BitList, Init *V) {
-  if (!V) return;
-
-  Record *TheRec = getActiveRec();
-  RecordVal *RV = TheRec->getValue(ValName);
-  if (RV == 0) {
-    err() << "Value '" << ValName << "' unknown!\n";
-    exit(1);
-  }
-
-  // Do not allow assignments like 'X = X'.  This will just cause infinite loops
-  // in the resolution machinery.
-  if (!BitList)
-    if (VarInit *VI = dynamic_cast<VarInit*>(V))
-      if (VI->getName() == ValName)
-        return;
-  
-  // If we are assigning to a subset of the bits in the value... then we must be
-  // assigning to a field of BitsRecTy, which must have a BitsInit
-  // initializer...
-  //
-  if (BitList) {
-    BitsInit *CurVal = dynamic_cast<BitsInit*>(RV->getValue());
-    if (CurVal == 0) {
-      err() << "Value '" << ValName << "' is not a bits type!\n";
-      exit(1);
-    }
-
-    // Convert the incoming value to a bits type of the appropriate size...
-    Init *BI = V->convertInitializerTo(new BitsRecTy(BitList->size()));
-    if (BI == 0) {
-      V->convertInitializerTo(new BitsRecTy(BitList->size()));
-      err() << "Initializer '" << *V << "' not compatible with bit range!\n";
-      exit(1);
-    }
-
-    // We should have a BitsInit type now...
-    assert(dynamic_cast<BitsInit*>(BI) != 0 || (cerr << *BI).stream() == 0);
-    BitsInit *BInit = (BitsInit*)BI;
-
-    BitsInit *NewVal = new BitsInit(CurVal->getNumBits());
-
-    // Loop over bits, assigning values as appropriate...
-    for (unsigned i = 0, e = BitList->size(); i != e; ++i) {
-      unsigned Bit = (*BitList)[i];
-      if (NewVal->getBit(Bit)) {
-        err() << "Cannot set bit #" << Bit << " of value '" << ValName
-              << "' more than once!\n";
-        exit(1);
-      }
-      NewVal->setBit(Bit, BInit->getBit(i));
-    }
-
-    for (unsigned i = 0, e = CurVal->getNumBits(); i != e; ++i)
-      if (NewVal->getBit(i) == 0)
-        NewVal->setBit(i, CurVal->getBit(i));
-
-    V = NewVal;
-  }
-
-  if (RV->setValue(V)) {
-    err() << "Value '" << ValName << "' of type '" << *RV->getType()
-	  << "' is incompatible with initializer '" << *V << "'!\n";
-    exit(1);
-  }
-}
-
-// addSubClass - Add SC as a subclass to CurRec, resolving TemplateArgs as SC's
-// template arguments.
-static void addSubClass(Record *SC, const std::vector<Init*> &TemplateArgs) {
-  // Add all of the values in the subclass into the current class...
-  const std::vector<RecordVal> &Vals = SC->getValues();
-  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
-    addValue(Vals[i]);
-
-  const std::vector<std::string> &TArgs = SC->getTemplateArgs();
-
-  // Ensure that an appropriate number of template arguments are specified...
-  if (TArgs.size() < TemplateArgs.size()) {
-    err() << "ERROR: More template args specified than expected!\n";
-    exit(1);
-  }
-  
-  // Loop over all of the template arguments, setting them to the specified
-  // value or leaving them as the default if necessary.
-  for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
-    if (i < TemplateArgs.size()) {  // A value is specified for this temp-arg?
-      // Set it now.
-      setValue(TArgs[i], 0, TemplateArgs[i]);
-
-      // Resolve it next.
-      CurRec->resolveReferencesTo(CurRec->getValue(TArgs[i]));
-                                  
-      
-      // Now remove it.
-      CurRec->removeValue(TArgs[i]);
-
-    } else if (!CurRec->getValue(TArgs[i])->getValue()->isComplete()) {
-      err() << "ERROR: Value not specified for template argument #"
-            << i << " (" << TArgs[i] << ") of subclass '" << SC->getName()
-            << "'!\n";
-      exit(1);
-    }
-  }
-
-  // Since everything went well, we can now set the "superclass" list for the
-  // current record.
-  const std::vector<Record*> &SCs = SC->getSuperClasses();
-  for (unsigned i = 0, e = SCs.size(); i != e; ++i)
-    addSuperClass(SCs[i]);
-  addSuperClass(SC);
-}
-
-} // End llvm namespace
-
-using namespace llvm;
-
-%}
-
-%union {
-  std::string*                StrVal;
-  int                         IntVal;
-  llvm::RecTy*                Ty;
-  llvm::Init*                 Initializer;
-  std::vector<llvm::Init*>*   FieldList;
-  std::vector<unsigned>*      BitList;
-  llvm::Record*               Rec;
-  std::vector<llvm::Record*>* RecList;
-  SubClassRefTy*              SubClassRef;
-  std::vector<SubClassRefTy>* SubClassList;
-  std::vector<std::pair<llvm::Init*, std::string> >* DagValueList;
-};
-
-%token INT BIT STRING BITS LIST CODE DAG CLASS DEF MULTICLASS DEFM FIELD LET IN
-%token CONCATTOK SHLTOK SRATOK SRLTOK STRCONCATTOK
-%token <IntVal>      INTVAL
-%token <StrVal>      ID VARNAME STRVAL CODEFRAGMENT
-
-%type <Ty>           Type
-%type <Rec>          ClassInst DefInst MultiClassDef ObjectBody ClassID
-%type <RecList>      MultiClassBody
-
-%type <SubClassRef>  SubClassRef
-%type <SubClassList> ClassList ClassListNE
-%type <IntVal>       OptPrefix
-%type <Initializer>  Value OptValue IDValue
-%type <DagValueList> DagArgList DagArgListNE
-%type <FieldList>    ValueList ValueListNE
-%type <BitList>      BitList OptBitList RBitList
-%type <StrVal>       Declaration OptID OptVarName ObjectName
-
-%start File
-
-%%
-
-ClassID : ID {
-    if (CurDefmPrefix) {
-      // If CurDefmPrefix is set, we're parsing a defm, which means that this is
-      // actually the name of a multiclass.
-      MultiClass *MC = MultiClasses[*$1];
-      if (MC == 0) {
-        err() << "Couldn't find class '" << *$1 << "'!\n";
-        exit(1);
-      }
-      $$ = &MC->Rec;
-    } else {
-      $$ = Records.getClass(*$1);
-    }
-    if ($$ == 0) {
-      err() << "Couldn't find class '" << *$1 << "'!\n";
-      exit(1);
-    }
-    delete $1;
-  };
-
-
-// TableGen types...
-Type : STRING {                       // string type
-    $$ = new StringRecTy();
-  } | BIT {                           // bit type
-    $$ = new BitRecTy();
-  } | BITS '<' INTVAL '>' {           // bits<x> type
-    $$ = new BitsRecTy($3);
-  } | INT {                           // int type
-    $$ = new IntRecTy();
-  } | LIST '<' Type '>'    {          // list<x> type
-    $$ = new ListRecTy($3);
-  } | CODE {                          // code type
-    $$ = new CodeRecTy();
-  } | DAG {                           // dag type
-    $$ = new DagRecTy();
-  } | ClassID {                       // Record Type
-    $$ = new RecordRecTy($1);
-  };
-
-OptPrefix : /*empty*/ { $$ = 0; } | FIELD { $$ = 1; };
-
-OptValue : /*empty*/ { $$ = 0; } | '=' Value { $$ = $2; };
-
-IDValue : ID {
-  if (const RecordVal *RV = (CurRec ? CurRec->getValue(*$1) : 0)) {
-    $$ = new VarInit(*$1, RV->getType());
-  } else if (CurRec && CurRec->isTemplateArg(CurRec->getName()+":"+*$1)) {
-    const RecordVal *RV = CurRec->getValue(CurRec->getName()+":"+*$1);
-    assert(RV && "Template arg doesn't exist??");
-    $$ = new VarInit(CurRec->getName()+":"+*$1, RV->getType());
-  } else if (CurMultiClass &&
-      CurMultiClass->Rec.isTemplateArg(CurMultiClass->Rec.getName()+"::"+*$1)) {
-    std::string Name = CurMultiClass->Rec.getName()+"::"+*$1;
-    const RecordVal *RV = CurMultiClass->Rec.getValue(Name);
-    assert(RV && "Template arg doesn't exist??");
-    $$ = new VarInit(Name, RV->getType());
-  } else if (Record *D = Records.getDef(*$1)) {
-    $$ = new DefInit(D);
-  } else {
-    err() << "Variable not defined: '" << *$1 << "'!\n";
-    exit(1);
-  }
-  
-  delete $1;
-};
-
-Value : IDValue {
-    $$ = $1;
-  } | INTVAL {
-    $$ = new IntInit($1);
-  } | STRVAL {
-    $$ = new StringInit(*$1);
-    delete $1;
-  } | CODEFRAGMENT {
-    $$ = new CodeInit(*$1);
-    delete $1;
-  } | '?' {
-    $$ = new UnsetInit();
-  } | '{' ValueList '}' {
-    BitsInit *Init = new BitsInit($2->size());
-    for (unsigned i = 0, e = $2->size(); i != e; ++i) {
-      struct Init *Bit = (*$2)[i]->convertInitializerTo(new BitRecTy());
-      if (Bit == 0) {
-        err() << "Element #" << i << " (" << *(*$2)[i]
-       	      << ") is not convertable to a bit!\n";
-        exit(1);
-      }
-      Init->setBit($2->size()-i-1, Bit);
-    }
-    $$ = Init;
-    delete $2;
-  } | ID '<' ValueListNE '>' {
-    // This is a CLASS<initvalslist> expression.  This is supposed to synthesize
-    // a new anonymous definition, deriving from CLASS<initvalslist> with no
-    // body.
-    Record *Class = Records.getClass(*$1);
-    if (!Class) {
-      err() << "Expected a class, got '" << *$1 << "'!\n";
-      exit(1);
-    }
-    delete $1;
-    
-    static unsigned AnonCounter = 0;
-    Record *OldRec = CurRec;  // Save CurRec.
-    
-    // Create the new record, set it as CurRec temporarily.
-    CurRec = new Record("anonymous.val."+utostr(AnonCounter++));
-    addSubClass(Class, *$3);    // Add info about the subclass to CurRec.
-    delete $3;  // Free up the template args.
-    
-    CurRec->resolveReferences();
-    
-    Records.addDef(CurRec);
-    
-    // The result of the expression is a reference to the new record.
-    $$ = new DefInit(CurRec);
-    
-    // Restore the old CurRec
-    CurRec = OldRec;
-  } | Value '{' BitList '}' {
-    $$ = $1->convertInitializerBitRange(*$3);
-    if ($$ == 0) {
-      err() << "Invalid bit range for value '" << *$1 << "'!\n";
-      exit(1);
-    }
-    delete $3;
-  } | '[' ValueList ']' {
-    $$ = new ListInit(*$2);
-    delete $2;
-  } | Value '.' ID {
-    if (!$1->getFieldType(*$3)) {
-      err() << "Cannot access field '" << *$3 << "' of value '" << *$1 << "!\n";
-      exit(1);
-    }
-    $$ = new FieldInit($1, *$3);
-    delete $3;
-  } | '(' IDValue DagArgList ')' {
-    $$ = new DagInit($2, *$3);
-    delete $3;
-  } | Value '[' BitList ']' {
-    std::reverse($3->begin(), $3->end());
-    $$ = $1->convertInitListSlice(*$3);
-    if ($$ == 0) {
-      err() << "Invalid list slice for value '" << *$1 << "'!\n";
-      exit(1);
-    }
-    delete $3;
-  } | CONCATTOK '(' Value ',' Value ')' {
-    $$ = (new BinOpInit(BinOpInit::CONCAT, $3, $5))->Fold();
-  } | SHLTOK '(' Value ',' Value ')' {
-    $$ = (new BinOpInit(BinOpInit::SHL, $3, $5))->Fold();
-  } | SRATOK '(' Value ',' Value ')' {
-    $$ = (new BinOpInit(BinOpInit::SRA, $3, $5))->Fold();
-  } | SRLTOK '(' Value ',' Value ')' {
-    $$ = (new BinOpInit(BinOpInit::SRL, $3, $5))->Fold();
-  } | STRCONCATTOK '(' Value ',' Value ')' {
-    $$ = (new BinOpInit(BinOpInit::STRCONCAT, $3, $5))->Fold();
-  };
-
-OptVarName : /* empty */ {
-    $$ = new std::string();
-  }
-  | ':' VARNAME {
-    $$ = $2;
-  };
-
-DagArgListNE : Value OptVarName {
-    $$ = new std::vector<std::pair<Init*, std::string> >();
-    $$->push_back(std::make_pair($1, *$2));
-    delete $2;
-  }
-  | DagArgListNE ',' Value OptVarName {
-    $1->push_back(std::make_pair($3, *$4));
-    delete $4;
-    $$ = $1;
-  };
-
-DagArgList : /*empty*/ {
-    $$ = new std::vector<std::pair<Init*, std::string> >();
-  }
-  | DagArgListNE { $$ = $1; };
-
-
-RBitList : INTVAL {
-    $$ = new std::vector<unsigned>();
-    $$->push_back($1);
-  } | INTVAL '-' INTVAL {
-    if ($1 < 0 || $3 < 0) {
-      err() << "Invalid range: " << $1 << "-" << $3 << "!\n";
-      exit(1);
-    }
-    $$ = new std::vector<unsigned>();
-    if ($1 < $3) {
-      for (int i = $1; i <= $3; ++i)
-        $$->push_back(i);
-    } else {
-      for (int i = $1; i >= $3; --i)
-        $$->push_back(i);
-    }
-  } | INTVAL INTVAL {
-    $2 = -$2;
-    if ($1 < 0 || $2 < 0) {
-      err() << "Invalid range: " << $1 << "-" << $2 << "!\n";
-      exit(1);
-    }
-    $$ = new std::vector<unsigned>();
-    if ($1 < $2) {
-      for (int i = $1; i <= $2; ++i)
-        $$->push_back(i);
-    } else {
-      for (int i = $1; i >= $2; --i)
-        $$->push_back(i);
-    }
-  } | RBitList ',' INTVAL {
-    ($$=$1)->push_back($3);
-  } | RBitList ',' INTVAL '-' INTVAL {
-    if ($3 < 0 || $5 < 0) {
-      err() << "Invalid range: " << $3 << "-" << $5 << "!\n";
-      exit(1);
-    }
-    $$ = $1;
-    if ($3 < $5) {
-      for (int i = $3; i <= $5; ++i)
-        $$->push_back(i);
-    } else {
-      for (int i = $3; i >= $5; --i)
-        $$->push_back(i);
-    }
-  } | RBitList ',' INTVAL INTVAL {
-    $4 = -$4;
-    if ($3 < 0 || $4 < 0) {
-      err() << "Invalid range: " << $3 << "-" << $4 << "!\n";
-      exit(1);
-    }
-    $$ = $1;
-    if ($3 < $4) {
-      for (int i = $3; i <= $4; ++i)
-        $$->push_back(i);
-    } else {
-      for (int i = $3; i >= $4; --i)
-        $$->push_back(i);
-    }
-  };
-
-BitList : RBitList { $$ = $1; std::reverse($1->begin(), $1->end()); };
-
-OptBitList : /*empty*/ { $$ = 0; } | '{' BitList '}' { $$ = $2; };
-
-
-
-ValueList : /*empty*/ {
-    $$ = new std::vector<Init*>();
-  } | ValueListNE {
-    $$ = $1;
-  };
-
-ValueListNE : Value {
-    $$ = new std::vector<Init*>();
-    $$->push_back($1);
-  } | ValueListNE ',' Value {
-    ($$ = $1)->push_back($3);
-  };
-
-Declaration : OptPrefix Type ID OptValue {
-  std::string DecName = *$3;
-  if (ParsingTemplateArgs) {
-    if (CurRec) {
-      DecName = CurRec->getName() + ":" + DecName;
-    } else {
-      assert(CurMultiClass);
-    }
-    if (CurMultiClass)
-      DecName = CurMultiClass->Rec.getName() + "::" + DecName;
-  }
-
-  addValue(RecordVal(DecName, $2, $1));
-  setValue(DecName, 0, $4);
-  $$ = new std::string(DecName);
-};
-
-BodyItem : Declaration ';' {
-  delete $1;
-} | LET ID OptBitList '=' Value ';' {
-  setValue(*$2, $3, $5);
-  delete $2;
-  delete $3;
-};
-
-BodyList : /*empty*/ | BodyList BodyItem;
-Body : ';' | '{' BodyList '}';
-
-SubClassRef : ClassID {
-    $$ = new SubClassRefTy($1, new std::vector<Init*>());
-  } | ClassID '<' ValueListNE '>' {
-    $$ = new SubClassRefTy($1, $3);
-  };
-
-ClassListNE : SubClassRef {
-    $$ = new std::vector<SubClassRefTy>();
-    $$->push_back(*$1);
-    delete $1;
-  }
-  | ClassListNE ',' SubClassRef {
-    ($$=$1)->push_back(*$3);
-    delete $3;
-  };
-
-ClassList : /*empty */ {
-    $$ = new std::vector<SubClassRefTy>();
-  }
-  | ':' ClassListNE {
-    $$ = $2;
-  };
-
-DeclListNE : Declaration {
-  getActiveRec()->addTemplateArg(*$1);
-  delete $1;
-} | DeclListNE ',' Declaration {
-  getActiveRec()->addTemplateArg(*$3);
-  delete $3;
-};
-
-TemplateArgList : '<' DeclListNE '>' {};
-OptTemplateArgList : /*empty*/ | TemplateArgList;
-
-OptID : ID { $$ = $1; } | /*empty*/ { $$ = new std::string(); };
-
-ObjectName : OptID {
-  static unsigned AnonCounter = 0;
-  if ($1->empty())
-    *$1 = "anonymous."+utostr(AnonCounter++);
-  $$ = $1;
-};
-
-ClassName : ObjectName {
-  // If a class of this name already exists, it must be a forward ref.
-  if ((CurRec = Records.getClass(*$1))) {
-    // If the body was previously defined, this is an error.
-    if (!CurRec->getValues().empty() ||
-        !CurRec->getSuperClasses().empty() ||
-        !CurRec->getTemplateArgs().empty()) {
-      err() << "Class '" << CurRec->getName() << "' already defined!\n";
-      exit(1);
-    }
-  } else {
-    // If this is the first reference to this class, create and add it.
-    CurRec = new Record(*$1);
-    Records.addClass(CurRec);
-  }
-  delete $1;
-};
-
-DefName : ObjectName {
-  CurRec = new Record(*$1);
-  delete $1;
-  
-  if (!CurMultiClass) {
-    // Top-level def definition.
-    
-    // Ensure redefinition doesn't happen.
-    if (Records.getDef(CurRec->getName())) {
-      err() << "def '" << CurRec->getName() << "' already defined!\n";
-      exit(1);
-    }
-    Records.addDef(CurRec);
-  } else {
-    // Otherwise, a def inside a multiclass, add it to the multiclass.
-    for (unsigned i = 0, e = CurMultiClass->DefPrototypes.size(); i != e; ++i)
-      if (CurMultiClass->DefPrototypes[i]->getName() == CurRec->getName()) {
-        err() << "def '" << CurRec->getName()
-              << "' already defined in this multiclass!\n";
-        exit(1);
-      }
-    CurMultiClass->DefPrototypes.push_back(CurRec);
-  }
-};
-
-ObjectBody : ClassList {
-           for (unsigned i = 0, e = $1->size(); i != e; ++i) {
-             addSubClass((*$1)[i].first, *(*$1)[i].second);
-             // Delete the template arg values for the class
-             delete (*$1)[i].second;
-           }
-           delete $1;   // Delete the class list.
-  
-           // Process any variables on the let stack.
-           for (unsigned i = 0, e = LetStack.size(); i != e; ++i)
-             for (unsigned j = 0, e = LetStack[i].size(); j != e; ++j)
-               setValue(LetStack[i][j].Name,
-                        LetStack[i][j].HasBits ? &LetStack[i][j].Bits : 0,
-                        LetStack[i][j].Value);
-         } Body {
-           $$ = CurRec;
-           CurRec = 0;
-         };
-
-ClassInst : CLASS ClassName {
-                ParsingTemplateArgs = true;
-            } OptTemplateArgList {
-                ParsingTemplateArgs = false;
-            } ObjectBody {
-        $$ = $6;
-     };
-
-DefInst : DEF DefName ObjectBody {
-  if (CurMultiClass == 0)  // Def's in multiclasses aren't really defs.
-    $3->resolveReferences();
-
-  // If ObjectBody has template arguments, it's an error.
-  assert($3->getTemplateArgs().empty() && "How'd this get template args?");
-  $$ = $3;
-};
-
-// MultiClassDef - A def instance specified inside a multiclass.
-MultiClassDef : DefInst {
-  $$ = $1;
-  // Copy the template arguments for the multiclass into the def.
-  const std::vector<std::string> &TArgs = CurMultiClass->Rec.getTemplateArgs();
-  
-  for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
-    const RecordVal *RV = CurMultiClass->Rec.getValue(TArgs[i]);
-    assert(RV && "Template arg doesn't exist?");
-    $$->addValue(*RV);
-  }
-};
-
-// MultiClassBody - Sequence of def's that are instantiated when a multiclass is
-// used.
-MultiClassBody : MultiClassDef {
-  $$ = new std::vector<Record*>();
-  $$->push_back($1);
-} | MultiClassBody MultiClassDef {
-  $$->push_back($2);  
-};
-
-MultiClassName : ID {
-  MultiClass *&MCE = MultiClasses[*$1];
-  if (MCE) {
-    err() << "multiclass '" << *$1 << "' already defined!\n";
-    exit(1);
-  }
-  MCE = CurMultiClass = new MultiClass(*$1);
-  delete $1;
-};
-
-// MultiClass - Multiple definitions.
-MultiClassInst : MULTICLASS MultiClassName {
-                                             ParsingTemplateArgs = true;
-                                           } OptTemplateArgList {
-                                             ParsingTemplateArgs = false;
-                                           }'{' MultiClassBody '}' {
-  CurMultiClass = 0;
-};
-
-// DefMInst - Instantiate a multiclass.
-DefMInst : DEFM ID { CurDefmPrefix = $2; } ':' SubClassRef ';' {
-  // To instantiate a multiclass, we need to first get the multiclass, then
-  // instantiate each def contained in the multiclass with the SubClassRef
-  // template parameters.
-  MultiClass *MC = MultiClasses[$5->first->getName()];
-  assert(MC && "Didn't lookup multiclass correctly?");
-  std::vector<Init*> &TemplateVals = *$5->second;
-  delete $5;
-  
-  // Verify that the correct number of template arguments were specified.
-  const std::vector<std::string> &TArgs = MC->Rec.getTemplateArgs();
-  if (TArgs.size() < TemplateVals.size()) {
-    err() << "ERROR: More template args specified than multiclass expects!\n";
-    exit(1);
-  }
-  
-  // Loop over all the def's in the multiclass, instantiating each one.
-  for (unsigned i = 0, e = MC->DefPrototypes.size(); i != e; ++i) {
-    Record *DefProto = MC->DefPrototypes[i];
-    
-    // Add the suffix to the defm name to get the new name.
-    assert(CurRec == 0 && "A def is current?");
-    CurRec = new Record(*$2 + DefProto->getName());
-    
-    addSubClass(DefProto, std::vector<Init*>());
-    
-    // Loop over all of the template arguments, setting them to the specified
-    // value or leaving them as the default if necessary.
-    for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
-      if (i < TemplateVals.size()) { // A value is specified for this temp-arg?
-        // Set it now.
-        setValue(TArgs[i], 0, TemplateVals[i]);
-        
-        // Resolve it next.
-        CurRec->resolveReferencesTo(CurRec->getValue(TArgs[i]));
-        
-        // Now remove it.
-        CurRec->removeValue(TArgs[i]);
-        
-      } else if (!CurRec->getValue(TArgs[i])->getValue()->isComplete()) {
-        err() << "ERROR: Value not specified for template argument #"
-        << i << " (" << TArgs[i] << ") of multiclassclass '"
-        << MC->Rec.getName() << "'!\n";
-        exit(1);
-      }
-    }
-    
-    // If the mdef is inside a 'let' expression, add to each def.
-    for (unsigned i = 0, e = LetStack.size(); i != e; ++i)
-      for (unsigned j = 0, e = LetStack[i].size(); j != e; ++j)
-        setValue(LetStack[i][j].Name,
-                 LetStack[i][j].HasBits ? &LetStack[i][j].Bits : 0,
-                 LetStack[i][j].Value);
-    
-    
-    // Ensure redefinition doesn't happen.
-    if (Records.getDef(CurRec->getName())) {
-      err() << "def '" << CurRec->getName() << "' already defined, "
-            << "instantiating defm '" << *$2 << "' with subdef '"
-            << DefProto->getName() << "'!\n";
-      exit(1);
-    }
-    Records.addDef(CurRec);
-    
-    CurRec->resolveReferences();
-
-    CurRec = 0;
-  }
-  
-  delete &TemplateVals;
-  delete $2;
-  CurDefmPrefix = 0;
-};
-
-Object : ClassInst {} | DefInst {};
-Object : MultiClassInst | DefMInst;
-
-LETItem : ID OptBitList '=' Value {
-  LetStack.back().push_back(LetRecord(*$1, $2, $4));
-  delete $1; delete $2;
-};
-
-LETList : LETItem | LETList ',' LETItem;
-
-// LETCommand - A 'LET' statement start...
-LETCommand : LET { LetStack.push_back(std::vector<LetRecord>()); } LETList IN;
-
-// Support Set commands wrapping objects... both with and without braces.
-Object : LETCommand '{' ObjectList '}' {
-    LetStack.pop_back();
-  }
-  | LETCommand Object {
-    LetStack.pop_back();
-  };
-
-ObjectList : Object {} | ObjectList Object {};
-
-File : ObjectList;
-
-%%
-
-int yyerror(const char *ErrorMsg) {
-  err() << "Error parsing: " << ErrorMsg << "\n";
-  exit(1);
-}