diff --git a/Makefile.rules b/Makefile.rules
index 79a2e01..761cc81 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -1574,6 +1574,11 @@
 	$(Echo) "Building $(<F) disassembly tables with tblgen"
 	$(Verb) $(TableGen) -gen-disassembler -o $(call SYSPATH, $@) $<
 
+$(TARGET:%=$(ObjDir)/%GenEDInfo.inc.tmp): \
+$(ObjDir)/%GenEDInfo.inc.tmp : %.td $(ObjDir)/.dir
+	$(Echo) "Building $(<F) enhanced disassembly information with tblgen"
+	$(Verb) $(TableGen) -gen-enhanced-disassembly-info -o $(call SYSPATH, $@) $<
+
 $(TARGET:%=$(ObjDir)/%GenFastISel.inc.tmp): \
 $(ObjDir)/%GenFastISel.inc.tmp : %.td $(ObjDir)/.dir
 	$(Echo) "Building $(<F) \"fast\" instruction selector implementation with tblgen"
diff --git a/lib/Target/X86/Makefile b/lib/Target/X86/Makefile
index 895868b..f4ff894 100644
--- a/lib/Target/X86/Makefile
+++ b/lib/Target/X86/Makefile
@@ -18,6 +18,7 @@
                 X86GenAsmWriter1.inc X86GenDAGISel.inc  \
                 X86GenDisassemblerTables.inc X86GenFastISel.inc \
                 X86GenCallingConv.inc X86GenSubtarget.inc \
+		X86GenEDInfo.inc
 
 DIRS = AsmPrinter AsmParser Disassembler TargetInfo
 
diff --git a/utils/TableGen/EDEmitter.cpp b/utils/TableGen/EDEmitter.cpp
new file mode 100644
index 0000000..8d8ef87
--- /dev/null
+++ b/utils/TableGen/EDEmitter.cpp
@@ -0,0 +1,856 @@
+//===- EDEmitter.cpp - Generate instruction descriptions for ED -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This tablegen backend is responsible for emitting a description of each
+// instruction in a format that the enhanced disassembler can use to tokenize
+// and parse instructions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "EDEmitter.h"
+
+#include "CodeGenTarget.h"
+#include "Record.h"
+
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <vector>
+#include <string>
+
+#define MAX_OPERANDS 5
+#define MAX_SYNTAXES 2
+
+using namespace llvm;
+
+///////////////////////////////////////////////////////////
+// Support classes for emitting nested C data structures //
+///////////////////////////////////////////////////////////
+
+namespace {
+  
+  class EnumEmitter {
+  private:
+    std::string Name;
+    std::vector<std::string> Entries;
+  public:
+    EnumEmitter(const char *N) : Name(N) { 
+    }
+    int addEntry(const char *e) { 
+      Entries.push_back(std::string(e));
+      return Entries.size() - 1; 
+    }
+    void emit(raw_ostream &o, unsigned int &i) {
+      o.indent(i) << "enum " << Name.c_str() << " {" << "\n";
+      i += 2;
+      
+      unsigned int index = 0;
+      unsigned int numEntries = Entries.size();
+      for(index = 0; index < numEntries; ++index) {
+        o.indent(i) << Entries[index];
+        if(index < (numEntries - 1))
+          o << ",";
+        o << "\n";
+      }
+      
+      i -= 2;
+      o.indent(i) << "};" << "\n";
+    }
+    
+    void emitAsFlags(raw_ostream &o, unsigned int &i) {
+      o.indent(i) << "enum " << Name.c_str() << " {" << "\n";
+      i += 2;
+      
+      unsigned int index = 0;
+      unsigned int numEntries = Entries.size();
+      unsigned int flag = 1;
+      for (index = 0; index < numEntries; ++index) {
+        o.indent(i) << Entries[index] << " = " << format("0x%x", flag);
+        if (index < (numEntries - 1))
+          o << ",";
+        o << "\n";
+        flag <<= 1;
+      }
+      
+      i -= 2;
+      o.indent(i) << "};" << "\n";
+    }
+  };
+
+  class StructEmitter {
+  private:
+    std::string Name;
+    std::vector<std::string> MemberTypes;
+    std::vector<std::string> MemberNames;
+  public:
+    StructEmitter(const char *N) : Name(N) {
+    }
+    void addMember(const char *t, const char *n) {
+      MemberTypes.push_back(std::string(t));
+      MemberNames.push_back(std::string(n));
+    }
+    void emit(raw_ostream &o, unsigned int &i) {
+      o.indent(i) << "struct " << Name.c_str() << " {" << "\n";
+      i += 2;
+      
+      unsigned int index = 0;
+      unsigned int numMembers = MemberTypes.size();
+      for (index = 0; index < numMembers; ++index) {
+        o.indent(i) << MemberTypes[index] << " " << MemberNames[index] << ";";
+        o << "\n";
+      }
+      
+      i -= 2;
+      o.indent(i) << "};" << "\n";
+    }
+  };
+  
+  class ConstantEmitter {
+  public:
+    virtual ~ConstantEmitter() { }
+    virtual void emit(raw_ostream &o, unsigned int &i) = 0;
+  };
+  
+  class LiteralConstantEmitter : public ConstantEmitter {
+  private:
+    std::string Literal;
+  public:
+    LiteralConstantEmitter(const char *literal) : Literal(literal) {
+    }
+    LiteralConstantEmitter(int literal) {
+      char buf[256];
+      snprintf(buf, 256, "%d", literal);
+      Literal = buf;
+    }
+    void emit(raw_ostream &o, unsigned int &i) {
+      o << Literal;
+    }
+  };
+  
+  class CompoundConstantEmitter : public ConstantEmitter {
+  private:
+    std::vector<ConstantEmitter*> Entries;
+  public:
+    CompoundConstantEmitter() {
+    }
+    ~CompoundConstantEmitter() {
+      unsigned int index;
+      unsigned int numEntries = Entries.size();
+      for (index = 0; index < numEntries; ++index) {
+        delete Entries[index];
+      }
+    }
+    CompoundConstantEmitter &addEntry(ConstantEmitter *e) {
+      Entries.push_back(e);
+      return *this;
+    }
+    void emit(raw_ostream &o, unsigned int &i) {
+      o << "{" << "\n";
+      i += 2;
+  
+      unsigned int index;
+      unsigned int numEntries = Entries.size();
+      for (index = 0; index < numEntries; ++index) {
+        o.indent(i);
+        Entries[index]->emit(o, i);
+        if (index < (numEntries - 1))
+          o << ",";
+        o << "\n";
+      }
+      
+      i -= 2;
+      o.indent(i) << "}";
+    }
+  };
+  
+  class FlagsConstantEmitter : public ConstantEmitter {
+  private:
+    std::vector<std::string> Flags;
+  public:
+    FlagsConstantEmitter() {
+    }
+    FlagsConstantEmitter &addEntry(const char *f) {
+      Flags.push_back(std::string(f));
+      return *this;
+    }
+    void emit(raw_ostream &o, unsigned int &i) {
+      unsigned int index;
+      unsigned int numFlags = Flags.size();
+      if (numFlags == 0)
+        o << "0";
+      
+      for (index = 0; index < numFlags; ++index) {
+        o << Flags[index].c_str();
+        if (index < (numFlags - 1))
+          o << " | ";
+      }
+    }
+  };
+}
+
+EDEmitter::EDEmitter(RecordKeeper &R) : Records(R) {
+}
+
+//////////////////////////////////////////////
+// Support functions for parsing AsmStrings //
+//////////////////////////////////////////////
+
+/// parseError - A better error reporter for use in AsmString parsers
+///
+/// @arg asmString  - The original assembly string, for use in the error report
+/// @arg index      - The character where the error occurred
+/// @arg err        - The text of the error itself
+static void parseError(const std::string& asmString, 
+                       unsigned int index, 
+                       const char* err) {
+  errs() << "In: " << asmString.c_str() << "\n";
+  errs() << "Error at " << format("%d", index) << ": " << err << "\n";
+  llvm_unreachable("Parse error");
+}
+
+/// resolveBraces - Interprets the brace syntax in an AsmString in favor of just
+///   one syntax, and returns the result.  "{A}" is resolved to "A" for syntax 0
+///   and "" for all others; "{A|B}" is resolved to "A" for syntax 0, "B" for 
+///   syntax 1, and "" for all others; and so on.
+///
+/// @arg asmString    - The original string, as loaded from the .td file
+/// @arg syntaxIndex  - The index to use
+static std::string resolveBraces(const std::string &asmString, 
+                                 unsigned int syntaxIndex) {
+  std::string ret;
+  
+  unsigned int index;
+  unsigned int numChars = asmString.length();
+  
+  // Brace parsing countable-state transducer
+  //
+  // STATES       - -1, 0, 1, ..., error
+  // SYMBOLS      - '{', '|', '}', ?, EOF
+  // START STATE  - -1
+  //
+  // state  input   ->  state output
+  // -1     '{'     ->  0
+  // -1     '|'     ->  error
+  // -1     '}'     ->  error
+  // -1     ?       ->  -1    ?
+  // -1     EOF     ->  -1
+  // n      '{'     ->  error
+  // n      '|'     ->  n+1
+  // n      '}'     ->  -1
+  // n      ?       ->  n     ? if n == syntaxIndex
+  //                            if not
+  // n      EOF     ->  error
+  
+  int state = -1;
+  
+  for (index = 0; index < numChars; ++index) {
+    char input = asmString[index];
+        
+    switch (state) {
+    default:
+      switch (input) {
+      default:
+        if (state == (int)syntaxIndex)
+          ret.push_back(input);
+        break;
+      case '{':
+        parseError(asmString, index, "Nested { in AsmString");
+        break;
+      case '|':
+        state++;
+        break;
+      case '}':
+        state = -1;
+        break;
+      }
+      break;
+    case -1:
+      switch (input) {
+      default:
+        ret.push_back(input);
+        break;
+      case '{':
+        state = 0;
+        break;
+      case '|':
+        parseError(asmString, index, "| outside braces in AsmString");
+        break;
+      case '}':
+        parseError(asmString, index, "Unmatched } in AsmString");
+        break;
+      }
+      break;
+    }
+  }
+  
+  if (state != -1)
+    parseError(asmString, index, "Unmatched { in AsmString");
+  
+  return ret;
+}
+
+/// getOperandIndex - looks up a named operand in an instruction and determines
+///   its index in the operand descriptor array, returning the index or -1 if it
+///   is not present.
+///
+/// @arg asmString  - The assembly string for the instruction, for errors only
+/// @arg operand    - The operand's name
+/// @arg inst       - The instruction to use when looking up the operand
+static int8_t getOperandIndex(const std::string &asmString,
+                              const std::string &operand,
+                              const CodeGenInstruction &inst) {
+  int8_t operandIndex;
+  
+  if(operand.length() == 0) {
+    errs() << "In: " << asmString << "\n";
+    errs() << "Operand: " << operand << "\n";
+    llvm_unreachable("Empty operand");
+  }
+  
+  try {
+    operandIndex = inst.getOperandNamed(operand);
+  }
+  catch (...) {
+    return -1;
+  }
+  
+  return operandIndex;
+}
+
+/// isAlphanumeric - returns true if a character is a valid alphanumeric
+///   character, and false otherwise
+///
+/// input - The character to query
+static inline bool isAlphanumeric(char input) {
+  if((input >= 'a' && input <= 'z') ||
+     (input >= 'A' && input <= 'Z') ||
+     (input >= '0' && input <= '9') ||
+     (input == '_'))
+    return true;
+  else
+    return false;
+}
+
+/// populateOperandOrder - reads a resolved AsmString (see resolveBraces) and
+///   records the index into the operand descriptor array for each operand in
+///   that string, in the order of appearance.
+///
+/// @arg operandOrder - The array that will be populated with the operand
+///                     mapping.  Each entry will contain -1 (invalid index
+///                     into the operands present in the AsmString) or a number
+///                     representing an index in the operand descriptor array.
+/// @arg asmString    - The operand's name
+/// @arg inst         - The instruction to use when looking up the operand
+void populateOperandOrder(CompoundConstantEmitter *operandOrder,
+                          const std::string &asmString,
+                          const CodeGenInstruction &inst) {
+  std::string aux;
+  
+  unsigned int index;
+  unsigned int numChars = asmString.length();
+  unsigned int numArgs = 0;
+  
+  // Argument processing finite-state transducer
+  //
+  // STATES       - 0, 1, error
+  // SYMBOLS      - A(lphanumeric), '$', ?, EOF
+  // START STATE  - 0
+  //
+  // state  input   ->  state aux
+  // 0      A       ->  0
+  // 0      '$'     ->  1
+  // 0      ?       ->  0
+  // 0      EOF     ->  0
+  // 1      A       ->  1     A
+  // 1      '$'     ->  error
+  // 1      ?       ->  0     clear
+  // 1      EOF     ->  0     clear
+  
+  unsigned int state = 0;
+  
+  for (index = 0; index < numChars; ++index) {
+    char input = asmString[index];
+    
+    switch (state) {
+      default:
+        parseError(asmString, index, "Parser in unreachable state");
+      case 0:
+        if (input == '$') {
+          state = 1;
+        }
+        break;
+      case 1:
+        if (isAlphanumeric(input)) {
+          aux.push_back(input);
+        }
+        else if (input == '$') {
+          parseError(asmString, index, "$ found in argument name");
+        }
+        else {
+          int8_t operandIndex = getOperandIndex(asmString, aux, inst);
+          char buf[3];
+          snprintf(buf, sizeof(buf), "%d", operandIndex);
+          operandOrder->addEntry(new LiteralConstantEmitter(buf));
+          aux.clear();
+          state = 0;
+          numArgs++;
+        }
+        break;
+    }
+  }
+  
+  if (state == 1) {
+    int8_t operandIndex = getOperandIndex(asmString, aux, inst);
+    char buf[2];
+    snprintf(buf, 2, "%d", operandIndex);
+    operandOrder->addEntry(new LiteralConstantEmitter(buf));
+    aux.clear();
+    numArgs++;
+  }
+  
+  for(; numArgs < MAX_OPERANDS; numArgs++) {
+    operandOrder->addEntry(new LiteralConstantEmitter("-1"));
+  }
+}
+
+/////////////////////////////////////////////////////
+// Support functions for handling X86 instructions //
+/////////////////////////////////////////////////////
+
+#define ADDFLAG(flag) flags->addEntry(flag)
+
+#define REG(str) if (name == str) { ADDFLAG("kOperandFlagRegister"); return 0; }
+#define MEM(str) if (name == str) { ADDFLAG("kOperandFlagMemory"); return 0; }
+#define LEA(str) if (name == str) { ADDFLAG("kOperandFlagEffectiveAddress"); \
+                                    return 0; }
+#define IMM(str) if (name == str) { ADDFLAG("kOperandFlagImmediate"); \
+                                    return 0; }
+#define PCR(str) if (name == str) { ADDFLAG("kOperandFlagMemory"); \
+                                    ADDFLAG("kOperandFlagPCRelative"); \
+                                    return 0; }
+
+/// X86FlagFromOpName - Processes the name of a single X86 operand (which is
+///   actually its type) and translates it into an operand flag
+///
+/// @arg flags    - The flags object to add the flag to
+/// @arg name     - The name of the operand
+static int X86FlagFromOpName(FlagsConstantEmitter *flags,
+                             const std::string &name) {
+  REG("GR8");
+  REG("GR8_NOREX");
+  REG("GR16");
+  REG("GR32");
+  REG("GR32_NOREX");
+  REG("FR32");
+  REG("RFP32");
+  REG("GR64");
+  REG("FR64");
+  REG("VR64");
+  REG("RFP64");
+  REG("RFP80");
+  REG("VR128");
+  REG("RST");
+  REG("SEGMENT_REG");
+  REG("DEBUG_REG");
+  REG("CONTROL_REG_32");
+  REG("CONTROL_REG_64");
+  
+  MEM("i8mem");
+  MEM("i8mem_NOREX");
+  MEM("i16mem");
+  MEM("i32mem");
+  MEM("f32mem");
+  MEM("ssmem");
+  MEM("opaque32mem");
+  MEM("opaque48mem");
+  MEM("i64mem");
+  MEM("f64mem");
+  MEM("sdmem");
+  MEM("f80mem");
+  MEM("opaque80mem");
+  MEM("i128mem");
+  MEM("f128mem");
+  MEM("opaque512mem");
+  
+  LEA("lea32mem");
+  LEA("lea64_32mem");
+  LEA("lea64mem");
+  
+  IMM("i8imm");
+  IMM("i16imm");
+  IMM("i16i8imm");
+  IMM("i32imm");
+  IMM("i32imm_pcrel");
+  IMM("i32i8imm");
+  IMM("i64imm");
+  IMM("i64i8imm");
+  IMM("i64i32imm");
+  IMM("i64i32imm_pcrel");
+  IMM("SSECC");
+  
+  PCR("brtarget8");
+  PCR("offset8");
+  PCR("offset16");
+  PCR("offset32");
+  PCR("offset64");
+  PCR("brtarget");
+  
+  return 1;
+}
+
+#undef REG
+#undef MEM
+#undef LEA
+#undef IMM
+#undef PCR
+#undef ADDFLAG
+
+/// X86PopulateOperands - Handles all the operands in an X86 instruction, adding
+///   the appropriate flags to their descriptors
+///
+/// @operandFlags - A reference the array of operand flag objects
+/// @inst         - The instruction to use as a source of information
+static void X86PopulateOperands(
+  FlagsConstantEmitter *(&operandFlags)[MAX_OPERANDS],
+  const CodeGenInstruction &inst) {
+  if (!inst.TheDef->isSubClassOf("X86Inst"))
+    return;
+  
+  unsigned int index;
+  unsigned int numOperands = inst.OperandList.size();
+  
+  for (index = 0; index < numOperands; ++index) {
+    const CodeGenInstruction::OperandInfo &operandInfo = 
+      inst.OperandList[index];
+    Record &rec = *operandInfo.Rec;
+    
+    if (X86FlagFromOpName(operandFlags[index], rec.getName())) {
+      errs() << "Operand type: " << rec.getName().c_str() << "\n";
+      errs() << "Operand name: " << operandInfo.Name.c_str() << "\n";
+      errs() << "Instruction mame: " << inst.TheDef->getName().c_str() << "\n";
+      llvm_unreachable("Unhandled type");
+    }
+  }
+}
+
+/// decorate1 - Decorates a named operand with a new flag
+///
+/// @operandFlags - The array of operand flag objects, which don't have names
+/// @inst         - The CodeGenInstruction, which provides a way to translate
+///                 between names and operand indices
+/// @opName       - The name of the operand
+/// @flag         - The name of the flag to add
+static inline void decorate1(FlagsConstantEmitter *(&operandFlags)[MAX_OPERANDS],
+                             const CodeGenInstruction &inst,
+                             const char *opName,
+                             const char *opFlag) {
+  unsigned opIndex;
+  
+  try {
+    opIndex = inst.getOperandNamed(std::string(opName));
+  }
+  catch (...) {
+    errs() << "Instruction: " << inst.TheDef->getName().c_str() << "\n";
+    errs() << "Operand name: " << opName << "\n";
+    llvm_unreachable("Couldn't find operand");
+  }
+  
+  operandFlags[opIndex]->addEntry(opFlag);
+}
+
+#define DECORATE1(opName, opFlag) decorate1(operandFlags, inst, opName, opFlag)
+
+#define MOV(source, target) {                       \
+  instFlags.addEntry("kInstructionFlagMove");       \
+  DECORATE1(source, "kOperandFlagSource");          \
+  DECORATE1(target, "kOperandFlagTarget");          \
+}
+
+#define BRANCH(target) {                            \
+  instFlags.addEntry("kInstructionFlagBranch");     \
+  DECORATE1(target, "kOperandFlagTarget");          \
+}
+
+#define PUSH(source) {                              \
+  instFlags.addEntry("kInstructionFlagPush");       \
+  DECORATE1(source, "kOperandFlagSource");          \
+}
+
+#define POP(target) {                               \
+  instFlags.addEntry("kInstructionFlagPop");        \
+  DECORATE1(target, "kOperandFlagTarget");          \
+}
+
+#define CALL(target) {                              \
+  instFlags.addEntry("kInstructionFlagCall");       \
+  DECORATE1(target, "kOperandFlagTarget");          \
+}
+
+#define RETURN() {                                  \
+  instFlags.addEntry("kInstructionFlagReturn");     \
+}
+
+/// X86ExtractSemantics - Performs various checks on the name of an X86
+///   instruction to determine what sort of an instruction it is and then adds 
+///   the appropriate flags to the instruction and its operands
+///
+/// @arg instFlags    - A reference to the flags for the instruction as a whole
+/// @arg operandFlags - A reference to the array of operand flag object pointers
+/// @arg inst         - A reference to the original instruction
+static void X86ExtractSemantics(FlagsConstantEmitter &instFlags,
+                                FlagsConstantEmitter *(&operandFlags)[MAX_OPERANDS],
+                                const CodeGenInstruction &inst) {
+  const std::string &name = inst.TheDef->getName();
+    
+  if (name.find("MOV") != name.npos) {
+    if (name.find("MOV_V") != name.npos) {
+      // ignore (this is a pseudoinstruction)
+    }
+    else if (name.find("MASK") != name.npos) {
+      // ignore (this is a masking move)
+    }
+    else if (name.find("r0") != name.npos) {
+      // ignore (this is a pseudoinstruction)
+    }
+    else if (name.find("PS") != name.npos ||
+             name.find("PD") != name.npos) {
+      // ignore (this is a shuffling move)
+    }
+    else if (name.find("MOVS") != name.npos) {
+      // ignore (this is a string move)
+    }
+    else if (name.find("_F") != name.npos) {
+      // TODO handle _F moves to ST(0)
+    }
+    else if (name.find("a") != name.npos) {
+      // TODO handle moves to/from %ax
+    }
+    else if (name.find("CMOV") != name.npos) {
+      MOV("src2", "dst");
+    }
+    else if (name.find("PC") != name.npos) {
+      MOV("label", "reg")
+    }
+    else {
+      MOV("src", "dst");
+    }
+  }
+  
+  if (name.find("JMP") != name.npos ||
+      name.find("J") == 0) {
+    if (name.find("FAR") != name.npos && name.find("i") != name.npos) {
+      BRANCH("off");
+    }
+    else {
+      BRANCH("dst");
+    }
+  }
+  
+  if (name.find("PUSH") != name.npos) {
+    if (name.find("FS") != name.npos ||
+        name.find("GS") != name.npos) {
+      instFlags.addEntry("kInstructionFlagPush");
+      // TODO add support for fixed operands
+    }
+    else if (name.find("F") != name.npos) {
+      // ignore (this pushes onto the FP stack)
+    }
+    else if (name[name.length() - 1] == 'm') {
+      PUSH("src");
+    }
+    else if (name.find("i") != name.npos) {
+      PUSH("imm");
+    }
+    else {
+      PUSH("reg");
+    }
+  }
+  
+  if (name.find("POP") != name.npos) {
+    if (name.find("POPCNT") != name.npos) {
+      // ignore (not a real pop)
+    }
+    else if (name.find("FS") != name.npos ||
+             name.find("GS") != name.npos) {
+      instFlags.addEntry("kInstructionFlagPop");
+      // TODO add support for fixed operands
+    }
+    else if (name.find("F") != name.npos) {
+      // ignore (this pops from the FP stack)
+    }
+    else if (name[name.length() - 1] == 'm') {
+      POP("dst");
+    }
+    else {
+      POP("reg");
+    }
+  }
+  
+  if (name.find("CALL") != name.npos) {
+    if (name.find("ADJ") != name.npos) {
+      // ignore (not a call)
+    }
+    else if (name.find("SYSCALL") != name.npos) {
+      // ignore (doesn't go anywhere we know about)
+    }
+    else if (name.find("VMCALL") != name.npos) {
+      // ignore (rather different semantics than a regular call)
+    }
+    else if (name.find("FAR") != name.npos && name.find("i") != name.npos) {
+      CALL("off");
+    }
+    else {
+      CALL("dst");
+    }
+  }
+  
+  if (name.find("RET") != name.npos) {
+    RETURN();
+  }
+}
+
+#undef MOV
+#undef BRANCH
+#undef PUSH
+#undef POP
+#undef CALL
+#undef RETURN
+
+#undef COND_DECORATE_2
+#undef COND_DECORATE_1
+#undef DECORATE1
+
+/// populateInstInfo - Fills an array of InstInfos with information about each 
+///   instruction in a target
+///
+/// @arg infoArray  - The array of InstInfo objects to populate
+/// @arg target     - The CodeGenTarget to use as a source of instructions
+static void populateInstInfo(CompoundConstantEmitter &infoArray,
+                             CodeGenTarget &target) {
+  std::vector<const CodeGenInstruction*> numberedInstructions;
+  target.getInstructionsByEnumValue(numberedInstructions);
+  
+  unsigned int index;
+  unsigned int numInstructions = numberedInstructions.size();
+  
+  for (index = 0; index < numInstructions; ++index) {
+    const CodeGenInstruction& inst = *numberedInstructions[index];
+    
+    CompoundConstantEmitter *infoStruct = new CompoundConstantEmitter;
+    infoArray.addEntry(infoStruct);
+    
+    FlagsConstantEmitter *instFlags = new FlagsConstantEmitter;
+    infoStruct->addEntry(instFlags);
+    
+    LiteralConstantEmitter *numOperandsEmitter = 
+      new LiteralConstantEmitter(inst.OperandList.size());
+    infoStruct->addEntry(numOperandsEmitter);
+                         
+    CompoundConstantEmitter *operandFlagArray = new CompoundConstantEmitter;
+    infoStruct->addEntry(operandFlagArray);
+        
+    FlagsConstantEmitter *operandFlags[MAX_OPERANDS];
+    
+    for (unsigned operandIndex = 0; operandIndex < MAX_OPERANDS; ++operandIndex) {
+      operandFlags[operandIndex] = new FlagsConstantEmitter;
+      operandFlagArray->addEntry(operandFlags[operandIndex]);
+    }
+ 
+    unsigned numSyntaxes = 0;
+    
+    if (target.getName() == "X86") {
+      X86PopulateOperands(operandFlags, inst);
+      X86ExtractSemantics(*instFlags, operandFlags, inst);
+      numSyntaxes = 2;
+    }
+    
+    CompoundConstantEmitter *operandOrderArray = new CompoundConstantEmitter;
+    infoStruct->addEntry(operandOrderArray);
+    
+    for (unsigned syntaxIndex = 0; syntaxIndex < MAX_SYNTAXES; ++syntaxIndex) {
+      CompoundConstantEmitter *operandOrder = new CompoundConstantEmitter;
+      operandOrderArray->addEntry(operandOrder);
+      
+      if (syntaxIndex < numSyntaxes) {
+        std::string asmString = inst.AsmString;
+        asmString = resolveBraces(asmString, syntaxIndex);
+        populateOperandOrder(operandOrder, asmString, inst);
+      }
+      else {
+        for (unsigned operandIndex = 0; 
+             operandIndex < MAX_OPERANDS; 
+             ++operandIndex) {
+          operandOrder->addEntry(new LiteralConstantEmitter("-1"));
+        }
+      }
+    }
+  }
+}
+
+void EDEmitter::run(raw_ostream &o) {
+  unsigned int i = 0;
+  
+  CompoundConstantEmitter infoArray;
+  CodeGenTarget target;
+  
+  populateInstInfo(infoArray, target);
+  
+  o << "InstInfo instInfo" << target.getName().c_str() << "[] = ";
+  infoArray.emit(o, i);
+  o << ";" << "\n";
+}
+
+void EDEmitter::runHeader(raw_ostream &o) {
+  EmitSourceFileHeader("Semantic Information Header", o);
+  
+  o << "#ifndef SemanticInfo_" << "\n";
+  o << "#define SemanticInfo_" << "\n";
+  o << "\n";
+  o << "#include <inttypes.h>" << "\n";
+  o << "\n";
+  o << "#define MAX_OPERANDS " << format("%d", MAX_OPERANDS) << "\n";
+  o << "#define MAX_SYNTAXES " << format("%d", MAX_SYNTAXES) << "\n";
+  o << "\n";
+  
+  unsigned int i = 0;
+  
+  EnumEmitter operandFlags("OperandFlags");
+  operandFlags.addEntry("kOperandFlagImmediate");
+  operandFlags.addEntry("kOperandFlagRegister");
+  operandFlags.addEntry("kOperandFlagMemory");
+  operandFlags.addEntry("kOperandFlagEffectiveAddress");
+  operandFlags.addEntry("kOperandFlagPCRelative");
+  operandFlags.addEntry("kOperandFlagSource");
+  operandFlags.addEntry("kOperandFlagTarget");
+  operandFlags.emitAsFlags(o, i);
+  
+  o << "\n";
+  
+  EnumEmitter instructionFlags("InstructionFlags");
+  instructionFlags.addEntry("kInstructionFlagMove");
+  instructionFlags.addEntry("kInstructionFlagBranch");
+  instructionFlags.addEntry("kInstructionFlagPush");
+  instructionFlags.addEntry("kInstructionFlagPop");
+  instructionFlags.addEntry("kInstructionFlagCall");
+  instructionFlags.addEntry("kInstructionFlagReturn");
+  instructionFlags.emitAsFlags(o, i);
+  
+  o << "\n";
+  
+  StructEmitter instInfo("InstInfo");
+  instInfo.addMember("uint32_t", "instructionFlags");
+  instInfo.addMember("uint8_t", "numOperands");
+  instInfo.addMember("uint8_t", "operandFlags[MAX_OPERANDS]");
+  instInfo.addMember("const char", "operandOrders[MAX_SYNTAXES][MAX_OPERANDS]");
+  instInfo.emit(o, i);
+  
+  o << "\n";
+  o << "#endif" << "\n";
+}
diff --git a/utils/TableGen/EDEmitter.h b/utils/TableGen/EDEmitter.h
new file mode 100644
index 0000000..9e40a8b
--- /dev/null
+++ b/utils/TableGen/EDEmitter.h
@@ -0,0 +1,37 @@
+//===- EDEmitter.h - Generate instruction descriptions for ED ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This tablegen backend is responsible for emitting a description of each
+// instruction in a format that the semantic disassembler can use to tokenize
+// and parse instructions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SEMANTIC_INFO_EMITTER_H
+#define SEMANTIC_INFO_EMITTER_H
+
+#include "TableGenBackend.h"
+
+namespace llvm {
+  
+  class EDEmitter : public TableGenBackend {
+    RecordKeeper &Records;
+  public:
+    EDEmitter(RecordKeeper &R);
+    
+    // run - Output the instruction table.
+    void run(raw_ostream &o);
+    
+    // runHeader - Emit a header file that allows use of the instruction table.
+    void runHeader(raw_ostream &o);
+  };
+  
+} // End llvm namespace
+
+#endif
diff --git a/utils/TableGen/TableGen.cpp b/utils/TableGen/TableGen.cpp
index 7c8d288..f20ec00 100644
--- a/utils/TableGen/TableGen.cpp
+++ b/utils/TableGen/TableGen.cpp
@@ -22,6 +22,7 @@
 #include "CodeEmitterGen.h"
 #include "DAGISelEmitter.h"
 #include "DisassemblerEmitter.h"
+#include "EDEmitter.h"
 #include "FastISelEmitter.h"
 #include "InstrEnumEmitter.h"
 #include "InstrInfoEmitter.h"
@@ -58,6 +59,7 @@
   GenIntrinsic,
   GenTgtIntrinsic,
   GenLLVMCConf,
+  GenEDHeader, GenEDInfo,
   PrintEnums
 };
 
@@ -106,6 +108,10 @@
                                "Generate Clang diagnostic groups"),
                     clEnumValN(GenLLVMCConf, "gen-llvmc",
                                "Generate LLVMC configuration library"),
+                    clEnumValN(GenEDHeader, "gen-enhanced-disassembly-header",
+                               "Generate enhanced disassembly info header"),
+                    clEnumValN(GenEDInfo, "gen-enhanced-disassembly-info",
+                               "Generate enhanced disassembly info"),
                     clEnumValN(PrintEnums, "print-enums",
                                "Print enum values for a class"),
                     clEnumValEnd));
@@ -259,6 +265,12 @@
     case GenLLVMCConf:
       LLVMCConfigurationEmitter(Records).run(*Out);
       break;
+    case GenEDHeader:
+      EDEmitter(Records).runHeader(*Out);
+      break;
+    case GenEDInfo:
+      EDEmitter(Records).run(*Out);
+      break;
     case PrintEnums:
     {
       std::vector<Record*> Recs = Records.getAllDerivedDefinitions(Class);