Move TableGen's parser and entry point into a library

This is the first step towards splitting LLVM and Clang's tblgen executables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140951 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 1801 insertions, 0 deletions

diff --git a/include/llvm/TableGen/Error.h b/include/llvm/TableGen/Error.h
new file mode 100644
index 0000000000..c01b32b1c2
--- /dev/null
+++ b/include/llvm/TableGen/Error.h
@@ -0,0 +1,43 @@
+//===- llvm/TableGen/Error.h - tblgen error handling helpers ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains error handling helper routines to pretty-print diagnostic
+// messages from tblgen.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_ERROR_H
+#define LLVM_TABLEGEN_ERROR_H
+
+#include "llvm/Support/SourceMgr.h"
+
+namespace llvm {
+
+class TGError {
+  SMLoc Loc;
+  std::string Message;
+public:
+  TGError(SMLoc loc, const std::string &message) : Loc(loc), Message(message) {}
+
+  SMLoc getLoc() const { return Loc; }
+  const std::string &getMessage() const { return Message; }
+};
+
+void PrintError(SMLoc ErrorLoc, const Twine &Msg);
+void PrintError(const char *Loc, const Twine &Msg);
+void PrintError(const Twine &Msg);
+void PrintError(const TGError &Error);
+
+
+extern SourceMgr SrcMgr;
+
+
+} // end namespace "llvm"
+
+#endif
diff --git a/include/llvm/TableGen/Main.h b/include/llvm/TableGen/Main.h
new file mode 100644
index 0000000000..deaef4a990
--- /dev/null
+++ b/include/llvm/TableGen/Main.h
@@ -0,0 +1,26 @@
+//===- llvm/TableGen/Main.h - tblgen entry point ----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the common entry point for tblgen tools.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_MAIN_H
+#define LLVM_TABLEGEN_MAIN_H
+
+namespace llvm {
+
+class TableGenAction;
+
+/// Run the table generator, performing the specified Action on parsed records.
+int TableGenMain(char *argv0, TableGenAction &Action);
+
+}
+
+#endif
diff --git a/include/llvm/TableGen/Record.h b/include/llvm/TableGen/Record.h
new file mode 100644
index 0000000000..afce760998
--- /dev/null
+++ b/include/llvm/TableGen/Record.h
@@ -0,0 +1,1655 @@
+//===- llvm/TableGen/Record.h - Classes for Table Records -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the main TableGen data structures, including the TableGen
+// types, values, and high-level data structures.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_RECORD_H
+#define LLVM_TABLEGEN_RECORD_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/raw_ostream.h"
+#include <map>
+
+namespace llvm {
+class raw_ostream;
+
+// RecTy subclasses.
+class BitRecTy;
+class BitsRecTy;
+class IntRecTy;
+class StringRecTy;
+class ListRecTy;
+class CodeRecTy;
+class DagRecTy;
+class RecordRecTy;
+
+// Init subclasses.
+class Init;
+class UnsetInit;
+class BitInit;
+class BitsInit;
+class IntInit;
+class StringInit;
+class CodeInit;
+class ListInit;
+class UnOpInit;
+class BinOpInit;
+class TernOpInit;
+class DefInit;
+class DagInit;
+class TypedInit;
+class VarInit;
+class FieldInit;
+class VarBitInit;
+class VarListElementInit;
+
+// Other classes.
+class Record;
+class RecordVal;
+struct MultiClass;
+class RecordKeeper;
+
+//===----------------------------------------------------------------------===//
+//  Type Classes
+//===----------------------------------------------------------------------===//
+
+class RecTy {
+  ListRecTy *ListTy;
+public:
+  RecTy() : ListTy(0) {}
+  virtual ~RecTy() {}
+
+  virtual std::string getAsString() const = 0;
+  void print(raw_ostream &OS) const { OS << getAsString(); }
+  void dump() const;
+
+  /// typeIsConvertibleTo - Return true if all values of 'this' type can be
+  /// converted to the specified type.
+  virtual bool typeIsConvertibleTo(const RecTy *RHS) const = 0;
+
+  /// getListTy - Returns the type representing list<this>.
+  ListRecTy *getListTy();
+
+public:   // These methods should only be called from subclasses of Init
+  virtual Init *convertValue( UnsetInit *UI) { return 0; }
+  virtual Init *convertValue(   BitInit *BI) { return 0; }
+  virtual Init *convertValue(  BitsInit *BI) { return 0; }
+  virtual Init *convertValue(   IntInit *II) { return 0; }
+  virtual Init *convertValue(StringInit *SI) { return 0; }
+  virtual Init *convertValue(  ListInit *LI) { return 0; }
+  virtual Init *convertValue( UnOpInit *UI) {
+    return convertValue((TypedInit*)UI);
+  }
+  virtual Init *convertValue( BinOpInit *UI) {
+    return convertValue((TypedInit*)UI);
+  }
+  virtual Init *convertValue( TernOpInit *UI) {
+    return convertValue((TypedInit*)UI);
+  }
+  virtual Init *convertValue(  CodeInit *CI) { return 0; }
+  virtual Init *convertValue(VarBitInit *VB) { return 0; }
+  virtual Init *convertValue(   DefInit *DI) { return 0; }
+  virtual Init *convertValue(   DagInit *DI) { return 0; }
+  virtual Init *convertValue( TypedInit *TI) { return 0; }
+  virtual Init *convertValue(   VarInit *VI) {
+    return convertValue((TypedInit*)VI);
+  }
+  virtual Init *convertValue( FieldInit *FI) {
+    return convertValue((TypedInit*)FI);
+  }
+
+public:   // These methods should only be called by subclasses of RecTy.
+  // baseClassOf - These virtual methods should be overloaded to return true iff
+  // all values of type 'RHS' can be converted to the 'this' type.
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
+};
+
+inline raw_ostream &operator<<(raw_ostream &OS, const RecTy &Ty) {
+  Ty.print(OS);
+  return OS;
+}
+
+
+/// BitRecTy - 'bit' - Represent a single bit
+///
+class BitRecTy : public RecTy {
+  static BitRecTy Shared;
+  BitRecTy() {}
+public:
+  static BitRecTy *get() { return &Shared; }
+
+  virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
+  virtual Init *convertValue(   BitInit *BI) { return (Init*)BI; }
+  virtual Init *convertValue(  BitsInit *BI);
+  virtual Init *convertValue(   IntInit *II);
+  virtual Init *convertValue(StringInit *SI) { return 0; }
+  virtual Init *convertValue(  ListInit *LI) { return 0; }
+  virtual Init *convertValue(  CodeInit *CI) { return 0; }
+  virtual Init *convertValue(VarBitInit *VB) { return (Init*)VB; }
+  virtual Init *convertValue(   DefInit *DI) { return 0; }
+  virtual Init *convertValue(   DagInit *DI) { return 0; }
+  virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TypedInit *TI);
+  virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
+  virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
+
+  std::string getAsString() const { return "bit"; }
+
+  bool typeIsConvertibleTo(const RecTy *RHS) const {
+    return RHS->baseClassOf(this);
+  }
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return true; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const;
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return true; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
+
+};
+
+
+// BitsRecTy - 'bits<n>' - Represent a fixed number of bits
+/// BitsRecTy - 'bits&lt;n&gt;' - Represent a fixed number of bits
+///
+class BitsRecTy : public RecTy {
+  unsigned Size;
+  explicit BitsRecTy(unsigned Sz) : Size(Sz) {}
+public:
+  static BitsRecTy *get(unsigned Sz);
+
+  unsigned getNumBits() const { return Size; }
+
+  virtual Init *convertValue( UnsetInit *UI);
+  virtual Init *convertValue(   BitInit *UI);
+  virtual Init *convertValue(  BitsInit *BI);
+  virtual Init *convertValue(   IntInit *II);
+  virtual Init *convertValue(StringInit *SI) { return 0; }
+  virtual Init *convertValue(  ListInit *LI) { return 0; }
+  virtual Init *convertValue(  CodeInit *CI) { return 0; }
+  virtual Init *convertValue(VarBitInit *VB) { return 0; }
+  virtual Init *convertValue(   DefInit *DI) { return 0; }
+  virtual Init *convertValue(   DagInit *DI) { return 0; }
+  virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TypedInit *TI);
+  virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
+  virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
+
+  std::string getAsString() const;
+
+  bool typeIsConvertibleTo(const RecTy *RHS) const {
+    return RHS->baseClassOf(this);
+  }
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return Size == 1; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const {
+    return RHS->Size == Size;
+  }
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return true; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
+
+};
+
+
+/// IntRecTy - 'int' - Represent an integer value of no particular size
+///
+class IntRecTy : public RecTy {
+  static IntRecTy Shared;
+  IntRecTy() {}
+public:
+  static IntRecTy *get() { return &Shared; }
+
+  virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
+  virtual Init *convertValue(   BitInit *BI);
+  virtual Init *convertValue(  BitsInit *BI);
+  virtual Init *convertValue(   IntInit *II) { return (Init*)II; }
+  virtual Init *convertValue(StringInit *SI) { return 0; }
+  virtual Init *convertValue(  ListInit *LI) { return 0; }
+  virtual Init *convertValue(  CodeInit *CI) { return 0; }
+  virtual Init *convertValue(VarBitInit *VB) { return 0; }
+  virtual Init *convertValue(   DefInit *DI) { return 0; }
+  virtual Init *convertValue(   DagInit *DI) { return 0; }
+  virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TypedInit *TI);
+  virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
+  virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
+
+  std::string getAsString() const { return "int"; }
+
+  bool typeIsConvertibleTo(const RecTy *RHS) const {
+    return RHS->baseClassOf(this);
+  }
+
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return true; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const { return true; }
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return true; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
+
+};
+
+/// StringRecTy - 'string' - Represent an string value
+///
+class StringRecTy : public RecTy {
+  static StringRecTy Shared;
+  StringRecTy() {}
+public:
+  static StringRecTy *get() { return &Shared; }
+
+  virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
+  virtual Init *convertValue(   BitInit *BI) { return 0; }
+  virtual Init *convertValue(  BitsInit *BI) { return 0; }
+  virtual Init *convertValue(   IntInit *II) { return 0; }
+  virtual Init *convertValue(StringInit *SI) { return (Init*)SI; }
+  virtual Init *convertValue(  ListInit *LI) { return 0; }
+  virtual Init *convertValue( UnOpInit *BO);
+  virtual Init *convertValue( BinOpInit *BO);
+  virtual Init *convertValue( TernOpInit *BO) { return RecTy::convertValue(BO);}
+
+  virtual Init *convertValue(  CodeInit *CI) { return 0; }
+  virtual Init *convertValue(VarBitInit *VB) { return 0; }
+  virtual Init *convertValue(   DefInit *DI) { return 0; }
+  virtual Init *convertValue(   DagInit *DI) { return 0; }
+  virtual Init *convertValue( TypedInit *TI);
+  virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
+  virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
+
+  std::string getAsString() const { return "string"; }
+
+  bool typeIsConvertibleTo(const RecTy *RHS) const {
+    return RHS->baseClassOf(this);
+  }
+
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return true; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
+};
+
+// ListRecTy - 'list<Ty>' - Represent a list of values, all of which must be of
+// the specified type.
+/// ListRecTy - 'list&lt;Ty&gt;' - Represent a list of values, all of which must
+/// be of the specified type.
+///
+class ListRecTy : public RecTy {
+  RecTy *Ty;
+  explicit ListRecTy(RecTy *T) : Ty(T) {}
+  friend ListRecTy *RecTy::getListTy();
+public:
+  static ListRecTy *get(RecTy *T) { return T->getListTy(); }
+  RecTy *getElementType() const { return Ty; }
+
+  virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
+  virtual Init *convertValue(   BitInit *BI) { return 0; }
+  virtual Init *convertValue(  BitsInit *BI) { return 0; }
+  virtual Init *convertValue(   IntInit *II) { return 0; }
+  virtual Init *convertValue(StringInit *SI) { return 0; }
+  virtual Init *convertValue(  ListInit *LI);
+  virtual Init *convertValue(  CodeInit *CI) { return 0; }
+  virtual Init *convertValue(VarBitInit *VB) { return 0; }
+  virtual Init *convertValue(   DefInit *DI) { return 0; }
+  virtual Init *convertValue(   DagInit *DI) { return 0; }
+  virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TypedInit *TI);
+  virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
+  virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
+
+  std::string getAsString() const;
+
+  bool typeIsConvertibleTo(const RecTy *RHS) const {
+    return RHS->baseClassOf(this);
+  }
+
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const {
+    return RHS->getElementType()->typeIsConvertibleTo(Ty);
+  }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
+};
+
+/// CodeRecTy - 'code' - Represent an code fragment, function or method.
+///
+class CodeRecTy : public RecTy {
+  static CodeRecTy Shared;
+  CodeRecTy() {}
+public:
+  static CodeRecTy *get() { return &Shared; }
+
+  virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
+  virtual Init *convertValue(   BitInit *BI) { return 0; }
+  virtual Init *convertValue(  BitsInit *BI) { return 0; }
+  virtual Init *convertValue(   IntInit *II) { return 0; }
+  virtual Init *convertValue(StringInit *SI) { return 0; }
+  virtual Init *convertValue(  ListInit *LI) { return 0; }
+  virtual Init *convertValue(  CodeInit *CI) { return (Init*)CI; }
+  virtual Init *convertValue(VarBitInit *VB) { return 0; }
+  virtual Init *convertValue(   DefInit *DI) { return 0; }
+  virtual Init *convertValue(   DagInit *DI) { return 0; }
+  virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TypedInit *TI);
+  virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
+  virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
+
+  std::string getAsString() const { return "code"; }
+
+  bool typeIsConvertibleTo(const RecTy *RHS) const {
+    return RHS->baseClassOf(this);
+  }
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return true; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
+};
+
+/// DagRecTy - 'dag' - Represent a dag fragment
+///
+class DagRecTy : public RecTy {
+  static DagRecTy Shared;
+  DagRecTy() {}
+public:
+  static DagRecTy *get() { return &Shared; }
+
+  virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
+  virtual Init *convertValue(   BitInit *BI) { return 0; }
+  virtual Init *convertValue(  BitsInit *BI) { return 0; }
+  virtual Init *convertValue(   IntInit *II) { return 0; }
+  virtual Init *convertValue(StringInit *SI) { return 0; }
+  virtual Init *convertValue(  ListInit *LI) { return 0; }
+  virtual Init *convertValue(  CodeInit *CI) { return 0; }
+  virtual Init *convertValue(VarBitInit *VB) { return 0; }
+  virtual Init *convertValue(   DefInit *DI) { return 0; }
+  virtual Init *convertValue( UnOpInit *BO);
+  virtual Init *convertValue( BinOpInit *BO);
+  virtual Init *convertValue( TernOpInit *BO) { return RecTy::convertValue(BO);}
+  virtual Init *convertValue(   DagInit *CI) { return (Init*)CI; }
+  virtual Init *convertValue( TypedInit *TI);
+  virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
+  virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
+
+  std::string getAsString() const { return "dag"; }
+
+  bool typeIsConvertibleTo(const RecTy *RHS) const {
+    return RHS->baseClassOf(this);
+  }
+
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return true; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
+};
+
+
+/// RecordRecTy - '[classname]' - Represent an instance of a class, such as:
+/// (R32 X = EAX).
+///
+class RecordRecTy : public RecTy {
+  Record *Rec;
+  explicit RecordRecTy(Record *R) : Rec(R) {}
+  friend class Record;
+public:
+  static RecordRecTy *get(Record *R);
+
+  Record *getRecord() const { return Rec; }
+
+  virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
+  virtual Init *convertValue(   BitInit *BI) { return 0; }
+  virtual Init *convertValue(  BitsInit *BI) { return 0; }
+  virtual Init *convertValue(   IntInit *II) { return 0; }
+  virtual Init *convertValue(StringInit *SI) { return 0; }
+  virtual Init *convertValue(  ListInit *LI) { return 0; }
+  virtual Init *convertValue(  CodeInit *CI) { return 0; }
+  virtual Init *convertValue(VarBitInit *VB) { return 0; }
+  virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
+  virtual Init *convertValue(   DefInit *DI);
+  virtual Init *convertValue(   DagInit *DI) { return 0; }
+  virtual Init *convertValue( TypedInit *VI);
+  virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
+  virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
+
+  std::string getAsString() const;
+
+  bool typeIsConvertibleTo(const RecTy *RHS) const {
+    return RHS->baseClassOf(this);
+  }
+  virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
+  virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const CodeRecTy   *RHS) const { return false; }
+  virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
+  virtual bool baseClassOf(const RecordRecTy *RHS) const;
+};
+
+/// resolveTypes - Find a common type that T1 and T2 convert to.
+/// Return 0 if no such type exists.
+///
+RecTy *resolveTypes(RecTy *T1, RecTy *T2);
+
+//===----------------------------------------------------------------------===//
+//  Initializer Classes
+//===----------------------------------------------------------------------===//
+
+class Init {
+  Init(const Init &);  // Do not define.
+  Init &operator=(const Init &);  // Do not define.
+
+protected:
+  Init(void) {}
+
+public:
+  virtual ~Init() {}
+
+  /// isComplete - This virtual method should be overridden by values that may
+  /// not be completely specified yet.
+  virtual bool isComplete() const { return true; }
+
+  /// print - Print out this value.
+  void print(raw_ostream &OS) const { OS << getAsString(); }
+
+  /// getAsString - Convert this value to a string form.
+  virtual std::string getAsString() const = 0;
+  /// getAsUnquotedString - Convert this value to a string form,
+  /// without adding quote markers.  This primaruly affects
+  /// StringInits where we will not surround the string value with
+  /// quotes.
+  virtual std::string getAsUnquotedString() const { return getAsString(); }  
+
+  /// dump - Debugging method that may be called through a debugger, just
+  /// invokes print on stderr.
+  void dump() const;
+
+  /// convertInitializerTo - This virtual function is a simple call-back
+  /// function that should be overridden to call the appropriate
+  /// RecTy::convertValue method.
+  ///
+  virtual Init *convertInitializerTo(RecTy *Ty) const = 0;
+
+  /// convertInitializerBitRange - This method is used to implement the bitrange
+  /// selection operator.  Given an initializer, it selects the specified bits
+  /// out, returning them as a new init of bits type.  If it is not legal to use
+  /// the bit subscript operator on this initializer, return null.
+  ///
+  virtual Init *
+  convertInitializerBitRange(const std::vector<unsigned> &Bits) const {
+    return 0;
+  }
+
+  /// convertInitListSlice - This method is used to implement the list slice
+  /// selection operator.  Given an initializer, it selects the specified list
+  /// elements, returning them as a new init of list type.  If it is not legal
+  /// to take a slice of this, return null.
+  ///
+  virtual Init *
+  convertInitListSlice(const std::vector<unsigned> &Elements) const {
+    return 0;
+  }
+
+  /// getFieldType - This method is used to implement the FieldInit class.
+  /// Implementors of this method should return the type of the named field if
+  /// they are of record type.
+  ///
+  virtual RecTy *getFieldType(const std::string &FieldName) const { return 0; }
+
+  /// getFieldInit - This method complements getFieldType to return the
+  /// initializer for the specified field.  If getFieldType returns non-null
+  /// this method should return non-null, otherwise it returns null.
+  ///
+  virtual Init *getFieldInit(Record &R, const RecordVal *RV,
+                             const std::string &FieldName) const {
+    return 0;
+  }
+
+  /// resolveReferences - This method is used by classes that refer to other
+  /// variables which may not be defined at the time the expression is formed.
+  /// If a value is set for the variable later, this method will be called on
+  /// users of the value to allow the value to propagate out.
+  ///
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const {
+    return const_cast<Init *>(this);
+  }
+};
+
+inline raw_ostream &operator<<(raw_ostream &OS, const Init &I) {
+  I.print(OS); return OS;
+}
+
+/// TypedInit - This is the common super-class of types that have a specific,
+/// explicit, type.
+///
+class TypedInit : public Init {
+  RecTy *Ty;
+
+  TypedInit(const TypedInit &Other);  // Do not define.
+  TypedInit &operator=(const TypedInit &Other);  // Do not define.
+
+protected:
+  explicit TypedInit(RecTy *T) : Ty(T) {}
+
+public:
+  RecTy *getType() const { return Ty; }
+
+  virtual Init *
+  convertInitializerBitRange(const std::vector<unsigned> &Bits) const;
+  virtual Init *
+  convertInitListSlice(const std::vector<unsigned> &Elements) const;
+
+  /// getFieldType - This method is used to implement the FieldInit class.
+  /// Implementors of this method should return the type of the named field if
+  /// they are of record type.
+  ///
+  virtual RecTy *getFieldType(const std::string &FieldName) const;
+
+  /// resolveBitReference - This method is used to implement
+  /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
+  /// simply return the resolved value, otherwise we return null.
+  ///
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const = 0;
+
+  /// resolveListElementReference - This method is used to implement
+  /// VarListElementInit::resolveReferences.  If the list element is resolvable
+  /// now, we return the resolved value, otherwise we return null.
+  virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                            unsigned Elt) const = 0;
+};
+
+
+/// UnsetInit - ? - Represents an uninitialized value
+///
+class UnsetInit : public Init {
+  UnsetInit() : Init() {}
+  UnsetInit(const UnsetInit &);  // Do not define.
+  UnsetInit &operator=(const UnsetInit &Other);  // Do not define.
+
+public:
+  static UnsetInit *get();
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<UnsetInit *>(this));
+  }
+
+  virtual bool isComplete() const { return false; }
+  virtual std::string getAsString() const { return "?"; }
+};
+
+
+/// BitInit - true/false - Represent a concrete initializer for a bit.
+///
+class BitInit : public Init {
+  bool Value;
+
+  explicit BitInit(bool V) : Value(V) {}
+  BitInit(const BitInit &Other);  // Do not define.
+  BitInit &operator=(BitInit &Other);  // Do not define.
+
+public:
+  static BitInit *get(bool V);
+
+  bool getValue() const { return Value; }
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<BitInit *>(this));
+  }
+
+  virtual std::string getAsString() const { return Value ? "1" : "0"; }
+};
+
+/// BitsInit - { a, b, c } - Represents an initializer for a BitsRecTy value.
+/// It contains a vector of bits, whose size is determined by the type.
+///
+class BitsInit : public Init, public FoldingSetNode {
+  std::vector<Init*> Bits;
+
+  BitsInit(ArrayRef<Init *> Range) : Bits(Range.begin(), Range.end()) {}
+
+  BitsInit(const BitsInit &Other);  // Do not define.
+  BitsInit &operator=(const BitsInit &Other);  // Do not define.
+
+public:
+  static BitsInit *get(ArrayRef<Init *> Range);
+
+  void Profile(FoldingSetNodeID &ID) const;
+
+  unsigned getNumBits() const { return Bits.size(); }
+
+  Init *getBit(unsigned Bit) const {
+    assert(Bit < Bits.size() && "Bit index out of range!");
+    return Bits[Bit];
+  }
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<BitsInit *>(this));
+  }
+  virtual Init *
+  convertInitializerBitRange(const std::vector<unsigned> &Bits) const;
+
+  virtual bool isComplete() const {
+    for (unsigned i = 0; i != getNumBits(); ++i)
+      if (!getBit(i)->isComplete()) return false;
+    return true;
+  }
+  bool allInComplete() const {
+    for (unsigned i = 0; i != getNumBits(); ++i)
+      if (getBit(i)->isComplete()) return false;
+    return true;
+  }
+  virtual std::string getAsString() const;
+
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+};
+
+
+/// IntInit - 7 - Represent an initalization by a literal integer value.
+///
+class IntInit : public TypedInit {
+  int64_t Value;
+
+  explicit IntInit(int64_t V) : TypedInit(IntRecTy::get()), Value(V) {}
+
+  IntInit(const IntInit &Other);  // Do not define.
+  IntInit &operator=(const IntInit &Other);  // Do note define.
+
+public:
+  static IntInit *get(int64_t V);
+
+  int64_t getValue() const { return Value; }
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<IntInit *>(this));
+  }
+  virtual Init *
+  convertInitializerBitRange(const std::vector<unsigned> &Bits) const;
+
+  virtual std::string getAsString() const;
+
+  /// resolveBitReference - This method is used to implement
+  /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
+  /// simply return the resolved value, otherwise we return null.
+  ///
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const {
+    assert(0 && "Illegal bit reference off int");
+    return 0;
+  }
+
+  /// resolveListElementReference - This method is used to implement
+  /// VarListElementInit::resolveReferences.  If the list element is resolvable
+  /// now, we return the resolved value, otherwise we return null.
+  virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                            unsigned Elt) const {
+    assert(0 && "Illegal element reference off int");
+    return 0;
+  }
+};
+
+
+/// StringInit - "foo" - Represent an initialization by a string value.
+///
+class StringInit : public TypedInit {
+  std::string Value;
+
+  explicit StringInit(const std::string &V)
+    : TypedInit(StringRecTy::get()), Value(V) {}
+
+  StringInit(const StringInit &Other);  // Do not define.
+  StringInit &operator=(const StringInit &Other);  // Do not define.
+
+public:
+  static StringInit *get(const std::string &V);
+
+  const std::string &getValue() const { return Value; }
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<StringInit *>(this));
+  }
+
+  virtual std::string getAsString() const { return "\"" + Value + "\""; }
+  virtual std::string getAsUnquotedString() const { return Value; }
+
+  /// resolveBitReference - This method is used to implement
+  /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
+  /// simply return the resolved value, otherwise we return null.
+  ///
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const {
+    assert(0 && "Illegal bit reference off string");
+    return 0;
+  }
+
+  /// resolveListElementReference - This method is used to implement
+  /// VarListElementInit::resolveReferences.  If the list element is resolvable
+  /// now, we return the resolved value, otherwise we return null.
+  virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                            unsigned Elt) const {
+    assert(0 && "Illegal element reference off string");
+    return 0;
+  }
+};
+
+/// CodeInit - "[{...}]" - Represent a code fragment.
+///
+class CodeInit : public Init {
+  std::string Value;
+
+  explicit CodeInit(const std::string &V) : Value(V) {}
+
+  CodeInit(const CodeInit &Other);  // Do not define.
+  CodeInit &operator=(const CodeInit &Other);  // Do not define.
+
+public:
+  static CodeInit *get(const std::string &V);
+
+  const std::string &getValue() const { return Value; }
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<CodeInit *>(this));
+  }
+
+  virtual std::string getAsString() const { return "[{" + Value + "}]"; }
+};
+
+/// ListInit - [AL, AH, CL] - Represent a list of defs
+///
+class ListInit : public TypedInit, public FoldingSetNode {
+  std::vector<Init*> Values;
+public:
+  typedef std::vector<Init*>::const_iterator const_iterator;
+
+private:
+  explicit ListInit(ArrayRef<Init *> Range, RecTy *EltTy)
+      : TypedInit(ListRecTy::get(EltTy)), Values(Range.begin(), Range.end()) {}
+
+  ListInit(const ListInit &Other);  // Do not define.
+  ListInit &operator=(const ListInit &Other);  // Do not define.
+
+public:
+  static ListInit *get(ArrayRef<Init *> Range, RecTy *EltTy);
+
+  void Profile(FoldingSetNodeID &ID) const;
+
+  unsigned getSize() const { return Values.size(); }
+  Init *getElement(unsigned i) const {
+    assert(i < Values.size() && "List element index out of range!");
+    return Values[i];
+  }
+
+  Record *getElementAsRecord(unsigned i) const;
+
+  Init *convertInitListSlice(const std::vector<unsigned> &Elements) const;
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<ListInit *>(this));
+  }
+
+  /// resolveReferences - This method is used by classes that refer to other
+  /// variables which may not be defined at the time they expression is formed.
+  /// If a value is set for the variable later, this method will be called on
+  /// users of the value to allow the value to propagate out.
+  ///
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+
+  virtual std::string getAsString() const;
+
+  ArrayRef<Init*> getValues() const { return Values; }
+
+  inline const_iterator begin() const { return Values.begin(); }
+  inline const_iterator end  () const { return Values.end();   }
+
+  inline size_t         size () const { return Values.size();  }
+  inline bool           empty() const { return Values.empty(); }
+
+  /// resolveBitReference - This method is used to implement
+  /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
+  /// simply return the resolved value, otherwise we return null.
+  ///
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const {
+    assert(0 && "Illegal bit reference off list");
+    return 0;
+  }
+
+  /// resolveListElementReference - This method is used to implement
+  /// VarListElementInit::resolveReferences.  If the list element is resolvable
+  /// now, we return the resolved value, otherwise we return null.
+  virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                            unsigned Elt) const;
+};
+
+
+/// OpInit - Base class for operators
+///
+class OpInit : public TypedInit {
+  OpInit(const OpInit &Other);  // Do not define.
+  OpInit &operator=(OpInit &Other);  // Do not define.
+
+protected:
+  explicit OpInit(RecTy *Type) : TypedInit(Type) {}
+
+public:
+  // Clone - Clone this operator, replacing arguments with the new list
+  virtual OpInit *clone(std::vector<Init *> &Operands) const = 0;
+
+  virtual int getNumOperands() const = 0;
+  virtual Init *getOperand(int i) const = 0;
+
+  // Fold - If possible, fold this to a simpler init.  Return this if not
+  // possible to fold.
+  virtual Init *Fold(Record *CurRec, MultiClass *CurMultiClass) const = 0;
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<OpInit *>(this));
+  }
+
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const;
+  virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                            unsigned Elt) const;
+};
+
+
+/// UnOpInit - !op (X) - Transform an init.
+///
+class UnOpInit : public OpInit {
+public:
+  enum UnaryOp { CAST, HEAD, TAIL, EMPTY };
+private:
+  UnaryOp Opc;
+  Init *LHS;
+
+  UnOpInit(UnaryOp opc, Init *lhs, RecTy *Type)
+      : OpInit(Type), Opc(opc), LHS(lhs) {}
+
+  UnOpInit(const UnOpInit &Other);  // Do not define.
+  UnOpInit &operator=(const UnOpInit &Other);  // Do not define.
+
+public:
+  static UnOpInit *get(UnaryOp opc, Init *lhs, RecTy *Type);
+
+  // Clone - Clone this operator, replacing arguments with the new list
+  virtual OpInit *clone(std::vector<Init *> &Operands) const {
+    assert(Operands.size() == 1 &&
+           "Wrong number of operands for unary operation");
+    return UnOpInit::get(getOpcode(), *Operands.begin(), getType());
+  }
+
+  int getNumOperands() const { return 1; }
+  Init *getOperand(int i) const {
+    assert(i == 0 && "Invalid operand id for unary operator");
+    return getOperand();
+  }
+
+  UnaryOp getOpcode() const { return Opc; }
+  Init *getOperand() const { return LHS; }
+
+  // Fold - If possible, fold this to a simpler init.  Return this if not
+  // possible to fold.
+  Init *Fold(Record *CurRec, MultiClass *CurMultiClass) const;
+
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+
+  virtual std::string getAsString() const;
+};
+
+/// BinOpInit - !op (X, Y) - Combine two inits.
+///
+class BinOpInit : public OpInit {
+public:
+  enum BinaryOp { SHL, SRA, SRL, STRCONCAT, CONCAT, EQ };
+private:
+  BinaryOp Opc;
+  Init *LHS, *RHS;
+
+  BinOpInit(BinaryOp opc, Init *lhs, Init *rhs, RecTy *Type) :
+      OpInit(Type), Opc(opc), LHS(lhs), RHS(rhs) {}
+
+  BinOpInit(const BinOpInit &Other);  // Do not define.
+  BinOpInit &operator=(const BinOpInit &Other);  // Do not define.
+
+public:
+  static BinOpInit *get(BinaryOp opc, Init *lhs, Init *rhs,
+                        RecTy *Type);
+
+  // Clone - Clone this operator, replacing arguments with the new list
+  virtual OpInit *clone(std::vector<Init *> &Operands) const {
+    assert(Operands.size() == 2 &&
+           "Wrong number of operands for binary operation");
+    return BinOpInit::get(getOpcode(), Operands[0], Operands[1], getType());
+  }
+
+  int getNumOperands() const { return 2; }
+  Init *getOperand(int i) const {
+    assert((i == 0 || i == 1) && "Invalid operand id for binary operator");
+    if (i == 0) {
+      return getLHS();
+    } else {
+      return getRHS();
+    }
+  }
+
+  BinaryOp getOpcode() const { return Opc; }
+  Init *getLHS() const { return LHS; }
+  Init *getRHS() const { return RHS; }
+
+  // Fold - If possible, fold this to a simpler init.  Return this if not
+  // possible to fold.
+  Init *Fold(Record *CurRec, MultiClass *CurMultiClass) const;
+
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+
+  virtual std::string getAsString() const;
+};
+
+/// TernOpInit - !op (X, Y, Z) - Combine two inits.
+///
+class TernOpInit : public OpInit {
+public:
+  enum TernaryOp { SUBST, FOREACH, IF };
+private:
+  TernaryOp Opc;
+  Init *LHS, *MHS, *RHS;
+
+  TernOpInit(TernaryOp opc, Init *lhs, Init *mhs, Init *rhs,
+             RecTy *Type) :
+      OpInit(Type), Opc(opc), LHS(lhs), MHS(mhs), RHS(rhs) {}
+
+  TernOpInit(const TernOpInit &Other);  // Do not define.
+  TernOpInit &operator=(const TernOpInit &Other);  // Do not define.
+
+public:
+  static TernOpInit *get(TernaryOp opc, Init *lhs,
+                         Init *mhs, Init *rhs,
+                         RecTy *Type);
+
+  // Clone - Clone this operator, replacing arguments with the new list
+  virtual OpInit *clone(std::vector<Init *> &Operands) const {
+    assert(Operands.size() == 3 &&
+           "Wrong number of operands for ternary operation");
+    return TernOpInit::get(getOpcode(), Operands[0], Operands[1], Operands[2],
+                           getType());
+  }
+
+  int getNumOperands() const { return 3; }
+  Init *getOperand(int i) const {
+    assert((i == 0 || i == 1 || i == 2) &&
+           "Invalid operand id for ternary operator");
+    if (i == 0) {
+      return getLHS();
+    } else if (i == 1) {
+      return getMHS();
+    } else {
+      return getRHS();
+    }
+  }
+
+  TernaryOp getOpcode() const { return Opc; }
+  Init *getLHS() const { return LHS; }
+  Init *getMHS() const { return MHS; }
+  Init *getRHS() const { return RHS; }
+
+  // Fold - If possible, fold this to a simpler init.  Return this if not
+  // possible to fold.
+  Init *Fold(Record *CurRec, MultiClass *CurMultiClass) const;
+
+  virtual bool isComplete() const { return false; }
+
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+
+  virtual std::string getAsString() const;
+};
+
+
+/// VarInit - 'Opcode' - Represent a reference to an entire variable object.
+///
+class VarInit : public TypedInit {
+  std::string VarName;
+
+  explicit VarInit(const std::string &VN, RecTy *T)
+      : TypedInit(T), VarName(VN) {}
+
+  VarInit(const VarInit &Other);  // Do not define.
+  VarInit &operator=(const VarInit &Other);  // Do not define.
+
+public:
+  static VarInit *get(const std::string &VN, RecTy *T);
+  static VarInit *get(Init *VN, RecTy *T);
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<VarInit *>(this));
+  }
+
+  const std::string &getName() const { return VarName; }
+
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const;
+  virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                            unsigned Elt) const;
+
+  virtual RecTy *getFieldType(const std::string &FieldName) const;
+  virtual Init *getFieldInit(Record &R, const RecordVal *RV,
+                             const std::string &FieldName) const;
+
+  /// resolveReferences - This method is used by classes that refer to other
+  /// variables which may not be defined at the time they expression is formed.
+  /// If a value is set for the variable later, this method will be called on
+  /// users of the value to allow the value to propagate out.
+  ///
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+
+  virtual std::string getAsString() const { return VarName; }
+};
+
+
+/// VarBitInit - Opcode{0} - Represent access to one bit of a variable or field.
+///
+class VarBitInit : public Init {
+  TypedInit *TI;
+  unsigned Bit;
+
+  VarBitInit(TypedInit *T, unsigned B) : TI(T), Bit(B) {
+    assert(T->getType() && dynamic_cast<BitsRecTy*>(T->getType()) &&
+           ((BitsRecTy*)T->getType())->getNumBits() > B &&
+           "Illegal VarBitInit expression!");
+  }
+
+  VarBitInit(const VarBitInit &Other);  // Do not define.
+  VarBitInit &operator=(const VarBitInit &Other);  // Do not define.
+
+public:
+  static VarBitInit *get(TypedInit *T, unsigned B);
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<VarBitInit *>(this));
+  }
+
+  TypedInit *getVariable() const { return TI; }
+  unsigned getBitNum() const { return Bit; }
+
+  virtual std::string getAsString() const;
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+};
+
+/// VarListElementInit - List[4] - Represent access to one element of a var or
+/// field.
+class VarListElementInit : public TypedInit {
+  TypedInit *TI;
+  unsigned Element;
+
+  VarListElementInit(TypedInit *T, unsigned E)
+      : TypedInit(dynamic_cast<ListRecTy*>(T->getType())->getElementType()),
+          TI(T), Element(E) {
+    assert(T->getType() && dynamic_cast<ListRecTy*>(T->getType()) &&
+           "Illegal VarBitInit expression!");
+  }
+
+  VarListElementInit(const VarListElementInit &Other);  // Do not define.
+  VarListElementInit &operator=(const VarListElementInit &Other);  // Do
+                                                                   // not
+                                                                   // define.
+
+public:
+  static VarListElementInit *get(TypedInit *T, unsigned E);
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<VarListElementInit *>(this));
+  }
+
+  TypedInit *getVariable() const { return TI; }
+  unsigned getElementNum() const { return Element; }
+
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const;
+
+  /// resolveListElementReference - This method is used to implement
+  /// VarListElementInit::resolveReferences.  If the list element is resolvable
+  /// now, we return the resolved value, otherwise we return null.
+  virtual Init *resolveListElementReference(Record &R,
+                                            const RecordVal *RV,
+                                            unsigned Elt) const;
+
+  virtual std::string getAsString() const;
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+};
+
+/// DefInit - AL - Represent a reference to a 'def' in the description
+///
+class DefInit : public TypedInit {
+  Record *Def;
+
+  DefInit(Record *D, RecordRecTy *T) : TypedInit(T), Def(D) {}
+  friend class Record;
+
+  DefInit(const DefInit &Other);  // Do not define.
+  DefInit &operator=(const DefInit &Other);  // Do not define.
+
+public:
+  static DefInit *get(Record*);
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<DefInit *>(this));
+  }
+
+  Record *getDef() const { return Def; }
+
+  //virtual Init *convertInitializerBitRange(const std::vector<unsigned> &Bits);
+
+  virtual RecTy *getFieldType(const std::string &FieldName) const;
+  virtual Init *getFieldInit(Record &R, const RecordVal *RV,
+                             const std::string &FieldName) const;
+
+  virtual std::string getAsString() const;
+
+  /// resolveBitReference - This method is used to implement
+  /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
+  /// simply return the resolved value, otherwise we return null.
+  ///
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const {
+    assert(0 && "Illegal bit reference off def");
+    return 0;
+  }
+
+  /// resolveListElementReference - This method is used to implement
+  /// VarListElementInit::resolveReferences.  If the list element is resolvable
+  /// now, we return the resolved value, otherwise we return null.
+  virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                            unsigned Elt) const {
+    assert(0 && "Illegal element reference off def");
+    return 0;
+  }
+};
+
+
+/// FieldInit - X.Y - Represent a reference to a subfield of a variable
+///
+class FieldInit : public TypedInit {
+  Init *Rec;                // Record we are referring to
+  std::string FieldName;    // Field we are accessing
+
+  FieldInit(Init *R, const std::string &FN)
+      : TypedInit(R->getFieldType(FN)), Rec(R), FieldName(FN) {
+    assert(getType() && "FieldInit with non-record type!");
+  }
+
+  FieldInit(const FieldInit &Other);  // Do not define.
+  FieldInit &operator=(const FieldInit &Other);  // Do not define.
+
+public:
+  static FieldInit *get(Init *R, const std::string &FN);
+  static FieldInit *get(Init *R, const Init *FN);
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<FieldInit *>(this));
+  }
+
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const;
+  virtual Init *resolveListElementReference(Record &R,
+                                            const RecordVal *RV,
+                                            unsigned Elt) const;
+
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+
+  virtual std::string getAsString() const {
+    return Rec->getAsString() + "." + FieldName;
+  }
+};
+
+/// DagInit - (v a, b) - Represent a DAG tree value.  DAG inits are required
+/// to have at least one value then a (possibly empty) list of arguments.  Each
+/// argument can have a name associated with it.
+///
+class DagInit : public TypedInit, public FoldingSetNode {
+  Init *Val;
+  std::string ValName;
+  std::vector<Init*> Args;
+  std::vector<std::string> ArgNames;
+
+  DagInit(Init *V, const std::string &VN,
+          ArrayRef<Init *> ArgRange,
+          ArrayRef<std::string> NameRange)
+      : TypedInit(DagRecTy::get()), Val(V), ValName(VN),
+          Args(ArgRange.begin(), ArgRange.end()),
+          ArgNames(NameRange.begin(), NameRange.end()) {}
+
+  DagInit(const DagInit &Other);  // Do not define.
+  DagInit &operator=(const DagInit &Other);  // Do not define.
+
+public:
+  static DagInit *get(Init *V, const std::string &VN,
+                      ArrayRef<Init *> ArgRange,
+                      ArrayRef<std::string> NameRange);
+  static DagInit *get(Init *V, const std::string &VN,
+                      const std::vector<
+                        std::pair<Init*, std::string> > &args);
+
+  void Profile(FoldingSetNodeID &ID) const;
+
+  virtual Init *convertInitializerTo(RecTy *Ty) const {
+    return Ty->convertValue(const_cast<DagInit *>(this));
+  }
+
+  Init *getOperator() const { return Val; }
+
+  const std::string &getName() const { return ValName; }
+
+  unsigned getNumArgs() const { return Args.size(); }
+  Init *getArg(unsigned Num) const {
+    assert(Num < Args.size() && "Arg number out of range!");
+    return Args[Num];
+  }
+  const std::string &getArgName(unsigned Num) const {
+    assert(Num < ArgNames.size() && "Arg number out of range!");
+    return ArgNames[Num];
+  }
+
+  virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
+
+  virtual std::string getAsString() const;
+
+  typedef std::vector<Init*>::const_iterator       const_arg_iterator;
+  typedef std::vector<std::string>::const_iterator const_name_iterator;
+
+  inline const_arg_iterator  arg_begin() const { return Args.begin(); }
+  inline const_arg_iterator  arg_end  () const { return Args.end();   }
+
+  inline size_t              arg_size () const { return Args.size();  }
+  inline bool                arg_empty() const { return Args.empty(); }
+
+  inline const_name_iterator name_begin() const { return ArgNames.begin(); }
+  inline const_name_iterator name_end  () const { return ArgNames.end();   }
+
+  inline size_t              name_size () const { return ArgNames.size();  }
+  inline bool                name_empty() const { return ArgNames.empty(); }
+
+  virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
+                                    unsigned Bit) const {
+    assert(0 && "Illegal bit reference off dag");
+    return 0;
+  }
+
+  virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                            unsigned Elt) const {
+    assert(0 && "Illegal element reference off dag");
+    return 0;
+  }
+};
+
+//===----------------------------------------------------------------------===//
+//  High-Level Classes
+//===----------------------------------------------------------------------===//
+
+class RecordVal {
+  Init *Name;
+  RecTy *Ty;
+  unsigned Prefix;
+  Init *Value;
+public:
+  RecordVal(Init *N, RecTy *T, unsigned P);
+  RecordVal(const std::string &N, RecTy *T, unsigned P);
+
+  const std::string &getName() const;
+
+  unsigned getPrefix() const { return Prefix; }
+  RecTy *getType() const { return Ty; }
+  Init *getValue() const { return Value; }
+
+  bool setValue(Init *V) {
+    if (V) {
+      Value = V->convertInitializerTo(Ty);
+      return Value == 0;
+    }
+    Value = 0;
+    return false;
+  }
+
+  void dump() const;
+  void print(raw_ostream &OS, bool PrintSem = true) const;
+};
+
+inline raw_ostream &operator<<(raw_ostream &OS, const RecordVal &RV) {
+  RV.print(OS << "  ");
+  return OS;
+}
+
+class Record {
+  static unsigned LastID;
+
+  // Unique record ID.
+  unsigned ID;
+  Init *Name;
+  SMLoc Loc;
+  std::vector<std::string> TemplateArgs;
+  std::vector<RecordVal> Values;
+  std::vector<Record*> SuperClasses;
+
+  // Tracks Record instances. Not owned by Record.
+  RecordKeeper &TrackedRecords;
+
+  DefInit *TheInit;
+
+  void checkName();
+
+public:
+
+  // Constructs a record.
+  explicit Record(const std::string &N, SMLoc loc, RecordKeeper &records) :
+    ID(LastID++), Name(StringInit::get(N)), Loc(loc), TrackedRecords(records), TheInit(0) {}
+  ~Record() {}
+
+
+  static unsigned getNewUID() { return LastID++; }
+
+
+  unsigned getID() const { return ID; }
+
+  const std::string &getName() const;
+  void setName(Init *Name);               // Also updates RecordKeeper.
+  void setName(const std::string &Name);  // Also updates RecordKeeper.
+
+  SMLoc getLoc() const { return Loc; }
+
+  /// get the corresponding DefInit.
+  DefInit *getDefInit();
+
+  const std::vector<std::string> &getTemplateArgs() const {
+    return TemplateArgs;
+  }
+  const std::vector<RecordVal> &getValues() const { return Values; }
+  const std::vector<Record*>   &getSuperClasses() const { return SuperClasses; }
+
+  bool isTemplateArg(StringRef Name) const {
+    for (unsigned i = 0, e = TemplateArgs.size(); i != e; ++i)
+      if (TemplateArgs[i] == Name) return true;
+    return false;
+  }
+
+  const RecordVal *getValue(StringRef Name) const {
+    for (unsigned i = 0, e = Values.size(); i != e; ++i)
+      if (Values[i].getName() == Name) return &Values[i];
+    return 0;
+  }
+  RecordVal *getValue(StringRef Name) {
+    for (unsigned i = 0, e = Values.size(); i != e; ++i)
+      if (Values[i].getName() == Name) return &Values[i];
+    return 0;
+  }
+
+  void addTemplateArg(StringRef Name) {
+    assert(!isTemplateArg(Name) && "Template arg already defined!");
+    TemplateArgs.push_back(Name);
+  }
+
+  void addValue(const RecordVal &RV) {
+    assert(getValue(RV.getName()) == 0 && "Value already added!");
+    Values.push_back(RV);
+  }
+
+  void removeValue(StringRef Name) {
+    for (unsigned i = 0, e = Values.size(); i != e; ++i)
+      if (Values[i].getName() == Name) {
+        Values.erase(Values.begin()+i);
+        return;
+      }
+    assert(0 && "Cannot remove an entry that does not exist!");
+  }
+
+  bool isSubClassOf(const Record *R) const {
+    for (unsigned i = 0, e = SuperClasses.size(); i != e; ++i)
+      if (SuperClasses[i] == R)
+        return true;
+    return false;
+  }
+
+  bool isSubClassOf(StringRef Name) const {
+    for (unsigned i = 0, e = SuperClasses.size(); i != e; ++i)
+      if (SuperClasses[i]->getName() == Name)
+        return true;
+    return false;
+  }
+
+  void addSuperClass(Record *R) {
+    assert(!isSubClassOf(R) && "Already subclassing record!");
+    SuperClasses.push_back(R);
+  }
+
+  /// resolveReferences - If there are any field references that refer to fields
+  /// that have been filled in, we can propagate the values now.
+  ///
+  void resolveReferences() { resolveReferencesTo(0); }
+
+  /// resolveReferencesTo - If anything in this record refers to RV, replace the
+  /// reference to RV with the RHS of RV.  If RV is null, we resolve all
+  /// possible references.
+  void resolveReferencesTo(const RecordVal *RV);
+
+  RecordKeeper &getRecords() const {
+    return TrackedRecords;
+  }
+
+  void dump() const;
+
+  //===--------------------------------------------------------------------===//
+  // High-level methods useful to tablegen back-ends
+  //
+
+  /// getValueInit - Return the initializer for a value with the specified name,
+  /// or throw an exception if the field does not exist.
+  ///
+  Init *getValueInit(StringRef FieldName) const;
+
+  /// getValueAsString - This method looks up the specified field and returns
+  /// its value as a string, throwing an exception if the field does not exist
+  /// or if the value is not a string.
+  ///
+  std::string getValueAsString(StringRef FieldName) const;
+
+  /// getValueAsBitsInit - This method looks up the specified field and returns
+  /// its value as a BitsInit, throwing an exception if the field does not exist
+  /// or if the value is not the right type.
+  ///
+  BitsInit *getValueAsBitsInit(StringRef FieldName) const;
+
+  /// getValueAsListInit - This method looks up the specified field and returns
+  /// its value as a ListInit, throwing an exception if the field does not exist
+  /// or if the value is not the right type.
+  ///
+  ListInit *getValueAsListInit(StringRef FieldName) const;
+
+  /// getValueAsListOfDefs - This method looks up the specified field and
+  /// returns its value as a vector of records, throwing an exception if the
+  /// field does not exist or if the value is not the right type.
+  ///
+  std::vector<Record*> getValueAsListOfDefs(StringRef FieldName) const;
+
+  /// getValueAsListOfInts - This method looks up the specified field and
+  /// returns its value as a vector of integers, throwing an exception if the
+  /// field does not exist or if the value is not the right type.
+  ///
+  std::vector<int64_t> getValueAsListOfInts(StringRef FieldName) const;
+
+  /// getValueAsListOfStrings - This method looks up the specified field and
+  /// returns its value as a vector of strings, throwing an exception if the
+  /// field does not exist or if the value is not the right type.
+  ///
+  std::vector<std::string> getValueAsListOfStrings(StringRef FieldName) const;
+
+  /// getValueAsDef - This method looks up the specified field and returns its
+  /// value as a Record, throwing an exception if the field does not exist or if
+  /// the value is not the right type.
+  ///
+  Record *getValueAsDef(StringRef FieldName) const;
+
+  /// getValueAsBit - This method looks up the specified field and returns its
+  /// value as a bit, throwing an exception if the field does not exist or if
+  /// the value is not the right type.
+  ///
+  bool getValueAsBit(StringRef FieldName) const;
+
+  /// getValueAsInt - This method looks up the specified field and returns its
+  /// value as an int64_t, throwing an exception if the field does not exist or
+  /// if the value is not the right type.
+  ///
+  int64_t getValueAsInt(StringRef FieldName) const;
+
+  /// getValueAsDag - This method looks up the specified field and returns its
+  /// value as an Dag, throwing an exception if the field does not exist or if
+  /// the value is not the right type.
+  ///
+  DagInit *getValueAsDag(StringRef FieldName) const;
+
+  /// getValueAsCode - This method looks up the specified field and returns
+  /// its value as the string data in a CodeInit, throwing an exception if the
+  /// field does not exist or if the value is not a code object.
+  ///
+  std::string getValueAsCode(StringRef FieldName) const;
+};
+
+raw_ostream &operator<<(raw_ostream &OS, const Record &R);
+
+struct MultiClass {
+  Record Rec;  // Placeholder for template args and Name.
+  typedef std::vector<Record*> RecordVector;
+  RecordVector DefPrototypes;
+
+  void dump() const;
+
+  MultiClass(const std::string &Name, SMLoc Loc, RecordKeeper &Records) : 
+    Rec(Name, Loc, Records) {}
+};
+
+class RecordKeeper {
+  std::map<std::string, Record*> Classes, Defs;
+public:
+  ~RecordKeeper() {
+    for (std::map<std::string, Record*>::iterator I = Classes.begin(),
+           E = Classes.end(); I != E; ++I)
+      delete I->second;
+    for (std::map<std::string, Record*>::iterator I = Defs.begin(),
+           E = Defs.end(); I != E; ++I)
+      delete I->second;
+  }
+
+  const std::map<std::string, Record*> &getClasses() const { return Classes; }
+  const std::map<std::string, Record*> &getDefs() const { return Defs; }
+
+  Record *getClass(const std::string &Name) const {
+    std::map<std::string, Record*>::const_iterator I = Classes.find(Name);
+    return I == Classes.end() ? 0 : I->second;
+  }
+  Record *getDef(const std::string &Name) const {
+    std::map<std::string, Record*>::const_iterator I = Defs.find(Name);
+    return I == Defs.end() ? 0 : I->second;
+  }
+  void addClass(Record *R) {
+    assert(getClass(R->getName()) == 0 && "Class already exists!");
+    Classes.insert(std::make_pair(R->getName(), R));
+  }
+  void addDef(Record *R) {
+    assert(getDef(R->getName()) == 0 && "Def already exists!");
+    Defs.insert(std::make_pair(R->getName(), R));
+  }
+
+  /// removeClass - Remove, but do not delete, the specified record.
+  ///
+  void removeClass(const std::string &Name) {
+    assert(Classes.count(Name) && "Class does not exist!");
+    Classes.erase(Name);
+  }
+  /// removeDef - Remove, but do not delete, the specified record.
+  ///
+  void removeDef(const std::string &Name) {
+    assert(Defs.count(Name) && "Def does not exist!");
+    Defs.erase(Name);
+  }
+
+  //===--------------------------------------------------------------------===//
+  // High-level helper methods, useful for tablegen backends...
+
+  /// getAllDerivedDefinitions - This method returns all concrete definitions
+  /// that derive from the specified class name.  If a class with the specified
+  /// name does not exist, an exception is thrown.
+  std::vector<Record*>
+  getAllDerivedDefinitions(const std::string &ClassName) const;
+
+  void dump() const;
+};
+
+/// LessRecord - Sorting predicate to sort record pointers by name.
+///
+struct LessRecord {
+  bool operator()(const Record *Rec1, const Record *Rec2) const {
+    return StringRef(Rec1->getName()).compare_numeric(Rec2->getName()) < 0;
+  }
+};
+
+/// LessRecordFieldName - Sorting predicate to sort record pointers by their
+/// name field.
+///
+struct LessRecordFieldName {
+  bool operator()(const Record *Rec1, const Record *Rec2) const {
+    return Rec1->getValueAsString("Name") < Rec2->getValueAsString("Name");
+  }
+};
+
+raw_ostream &operator<<(raw_ostream &OS, const RecordKeeper &RK);
+
+} // End llvm namespace
+
+#endif
diff --git a/include/llvm/TableGen/TableGenAction.h b/include/llvm/TableGen/TableGenAction.h
new file mode 100644
index 0000000000..9f1c23c5b4
--- /dev/null
+++ b/include/llvm/TableGen/TableGenAction.h
@@ -0,0 +1,34 @@
+//===- llvm/TableGen/TableGenAction.h - defines TableGenAction --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the TableGenAction base class to be derived from by
+// tblgen tools.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_TABLEGENACTION_H
+#define LLVM_TABLEGEN_TABLEGENACTION_H
+
+namespace llvm {
+
+class raw_ostream;
+class RecordKeeper;
+
+class TableGenAction {
+public:
+  virtual ~TableGenAction() {}
+
+  /// Perform the action using Records, and write output to OS.
+  /// @returns true on error, false otherwise
+  virtual bool operator()(raw_ostream &OS, RecordKeeper &Records) = 0;
+};
+
+}
+
+#endif
diff --git a/include/llvm/TableGen/TableGenBackend.h b/include/llvm/TableGen/TableGenBackend.h
new file mode 100644
index 0000000000..853f92e406
--- /dev/null
+++ b/include/llvm/TableGen/TableGenBackend.h
@@ -0,0 +1,43 @@
+//===- llvm/TableGen/TableGenBackend.h - Backend base class -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// The TableGenBackend class is provided as a common interface for all TableGen
+// backends.  It provides useful services and an standardized interface.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_TABLEGENBACKEND_H
+#define LLVM_TABLEGEN_TABLEGENBACKEND_H
+
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+
+namespace llvm {
+
+class Record;
+class RecordKeeper;
+
+struct TableGenBackend {
+  virtual ~TableGenBackend() {}
+
+  // run - All TableGen backends should implement the run method, which should
+  // be the main entry point.
+  virtual void run(raw_ostream &OS) = 0;
+
+
+public:   // Useful helper routines...
+  /// EmitSourceFileHeader - Output a LLVM style file header to the specified
+  /// ostream.
+  void EmitSourceFileHeader(const std::string &Desc, raw_ostream &OS) const;
+
+};
+
+} // End llvm namespace
+
+#endif