Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f

8 files changed, 371 insertions, 470 deletions

diff --git a/lib/Target/X86/Disassembler/Android.mk b/lib/Target/X86/Disassembler/Android.mk
index 3984266..0b3b8a5 100644
--- a/lib/Target/X86/Disassembler/Android.mk
+++ b/lib/Target/X86/Disassembler/Android.mk
@@ -8,7 +8,8 @@ x86_disassembler_TBLGEN_TABLES := \
 
 x86_disassembler_SRC_FILES := \
   X86Disassembler.cpp \
-  X86DisassemblerDecoder.c
+  X86DisassemblerDecoder.cpp
+
 
 # For the device
 # =====================================================
diff --git a/lib/Target/X86/Disassembler/CMakeLists.txt b/lib/Target/X86/Disassembler/CMakeLists.txt
index deed115..4370282 100644
--- a/lib/Target/X86/Disassembler/CMakeLists.txt
+++ b/lib/Target/X86/Disassembler/CMakeLists.txt
@@ -1,4 +1,4 @@
 add_llvm_library(LLVMX86Disassembler
   X86Disassembler.cpp
-  X86DisassemblerDecoder.c
+  X86DisassemblerDecoder.cpp
   )
diff --git a/lib/Target/X86/Disassembler/Makefile b/lib/Target/X86/Disassembler/Makefile
index 8669fd8..51e7b82 100644
--- a/lib/Target/X86/Disassembler/Makefile
+++ b/lib/Target/X86/Disassembler/Makefile
@@ -10,7 +10,9 @@
 LEVEL = ../../../..
 LIBRARYNAME = LLVMX86Disassembler
 
-# Hack: we need to include 'main' x86 target directory to grab private headers
+# Hack: we need to include 'main' x86 target directory to grab private headers.
 CPP.Flags += -I$(PROJ_OBJ_DIR)/.. -I$(PROJ_SRC_DIR)/..
 
 include $(LEVEL)/Makefile.common
+
+.PHONY: $(PROJ_SRC_DIR)/X86DisassemblerDecoder.c
diff --git a/lib/Target/X86/Disassembler/X86Disassembler.cpp b/lib/Target/X86/Disassembler/X86Disassembler.cpp
index d5759cd..c366725 100644
--- a/lib/Target/X86/Disassembler/X86Disassembler.cpp
+++ b/lib/Target/X86/Disassembler/X86Disassembler.cpp
@@ -27,6 +27,11 @@
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"
 
+using namespace llvm;
+using namespace llvm::X86Disassembler;
+
+#define DEBUG_TYPE "x86-disassembler"
+
 #define GET_REGINFO_ENUM
 #include "X86GenRegisterInfo.inc"
 #define GET_INSTRINFO_ENUM
@@ -34,21 +39,18 @@
 #define GET_SUBTARGETINFO_ENUM
 #include "X86GenSubtargetInfo.inc"
 
-using namespace llvm;
-using namespace llvm::X86Disassembler;
-
-void x86DisassemblerDebug(const char *file,
-                          unsigned line,
-                          const char *s) {
+void llvm::X86Disassembler::Debug(const char *file, unsigned line,
+                                  const char *s) {
   dbgs() << file << ":" << line << ": " << s;
 }
 
-const char *x86DisassemblerGetInstrName(unsigned Opcode, const void *mii) {
+const char *llvm::X86Disassembler::GetInstrName(unsigned Opcode,
+                                                const void *mii) {
   const MCInstrInfo *MII = static_cast<const MCInstrInfo *>(mii);
   return MII->getName(Opcode);
 }
 
-#define debug(s) DEBUG(x86DisassemblerDebug(__FILE__, __LINE__, s));
+#define debug(s) DEBUG(Debug(__FILE__, __LINE__, s));
 
 namespace llvm {  
   
@@ -74,9 +76,11 @@ static bool translateInstruction(MCInst &target,
                                 InternalInstruction &source,
                                 const MCDisassembler *Dis);
 
-X86GenericDisassembler::X86GenericDisassembler(const MCSubtargetInfo &STI,
-                                               const MCInstrInfo *MII)
-  : MCDisassembler(STI), MII(MII) {
+X86GenericDisassembler::X86GenericDisassembler(
+                                         const MCSubtargetInfo &STI,
+                                         MCContext &Ctx,
+                                         std::unique_ptr<const MCInstrInfo> MII)
+  : MCDisassembler(STI, Ctx), MII(std::move(MII)) {
   switch (STI.getFeatureBits() &
           (X86::Mode16Bit | X86::Mode32Bit | X86::Mode64Bit)) {
   case X86::Mode16Bit:
@@ -93,10 +97,6 @@ X86GenericDisassembler::X86GenericDisassembler(const MCSubtargetInfo &STI,
   }
 }
 
-X86GenericDisassembler::~X86GenericDisassembler() {
-  delete MII;
-}
-
 /// regionReader - a callback function that wraps the readByte method from
 ///   MemoryObject.
 ///
@@ -140,14 +140,14 @@ X86GenericDisassembler::getInstruction(MCInst &instr,
 
   dlog_t loggerFn = logger;
   if (&vStream == &nulls())
-    loggerFn = 0; // Disable logging completely if it's going to nulls().
+    loggerFn = nullptr; // Disable logging completely if it's going to nulls().
   
   int ret = decodeInstruction(&internalInstr,
                               regionReader,
                               (const void*)&region,
                               loggerFn,
                               (void*)&vStream,
-                              (const void*)MII,
+                              (const void*)MII.get(),
                               address,
                               fMode);
 
@@ -319,7 +319,7 @@ static void translateImmediate(MCInst &mcInst, uint64_t immediate,
   }
   // By default sign-extend all X86 immediates based on their encoding.
   else if (type == TYPE_IMM8 || type == TYPE_IMM16 || type == TYPE_IMM32 ||
-           type == TYPE_IMM64) {
+           type == TYPE_IMM64 || type == TYPE_IMMv) {
     uint32_t Opcode = mcInst.getOpcode();
     switch (operand.encoding) {
     default:
@@ -787,13 +787,11 @@ static bool translateInstruction(MCInst &mcInst,
       mcInst.setOpcode(X86::XACQUIRE_PREFIX);
   }
   
-  int index;
-  
   insn.numImmediatesTranslated = 0;
   
-  for (index = 0; index < X86_MAX_OPERANDS; ++index) {
-    if (insn.operands[index].encoding != ENCODING_NONE) {
-      if (translateOperand(mcInst, insn.operands[index], insn, Dis)) {
+  for (const auto &Op : insn.operands) {
+    if (Op.encoding != ENCODING_NONE) {
+      if (translateOperand(mcInst, Op, insn, Dis)) {
         return true;
       }
     }
@@ -803,9 +801,10 @@ static bool translateInstruction(MCInst &mcInst,
 }
 
 static MCDisassembler *createX86Disassembler(const Target &T,
-                                             const MCSubtargetInfo &STI) {
-  return new X86Disassembler::X86GenericDisassembler(STI,
-                                                     T.createMCInstrInfo());
+                                             const MCSubtargetInfo &STI,
+                                             MCContext &Ctx) {
+  std::unique_ptr<const MCInstrInfo> MII(T.createMCInstrInfo());
+  return new X86Disassembler::X86GenericDisassembler(STI, Ctx, std::move(MII));
 }
 
 extern "C" void LLVMInitializeX86Disassembler() { 
diff --git a/lib/Target/X86/Disassembler/X86Disassembler.h b/lib/Target/X86/Disassembler/X86Disassembler.h
index 4e6e297..4dc7c29 100644
--- a/lib/Target/X86/Disassembler/X86Disassembler.h
+++ b/lib/Target/X86/Disassembler/X86Disassembler.h
@@ -74,17 +74,7 @@
 #ifndef X86DISASSEMBLER_H
 #define X86DISASSEMBLER_H
 
-#define INSTRUCTION_SPECIFIER_FIELDS \
-  uint16_t operands;
-
-#define INSTRUCTION_IDS               \
-  uint16_t instructionIDs;
-
 #include "X86DisassemblerDecoderCommon.h"
-
-#undef INSTRUCTION_SPECIFIER_FIELDS
-#undef INSTRUCTION_IDS
-
 #include "llvm/MC/MCDisassembler.h"
 
 namespace llvm {
@@ -101,13 +91,12 @@ namespace X86Disassembler {
 ///   All each platform class should have to do is subclass the constructor, and
 ///   provide a different disassemblerMode value.
 class X86GenericDisassembler : public MCDisassembler {
-  const MCInstrInfo *MII;
+  std::unique_ptr<const MCInstrInfo> MII;
 public:
   /// Constructor     - Initializes the disassembler.
   ///
-  X86GenericDisassembler(const MCSubtargetInfo &STI, const MCInstrInfo *MII);
-private:
-  ~X86GenericDisassembler();
+  X86GenericDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx,
+                         std::unique_ptr<const MCInstrInfo> MII);
 public:
 
   /// getInstruction - See MCDisassembler.
diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
index 0801c96..804606d 100644
--- a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
+++ b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
@@ -1,17 +1,17 @@
-/*===-- X86DisassemblerDecoder.c - Disassembler decoder ------------*- C -*-===*
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is distributed under the University of Illinois Open Source
- * License. See LICENSE.TXT for details.
- *
- *===----------------------------------------------------------------------===*
- *
- * This file is part of the X86 Disassembler.
- * It contains the implementation of the instruction decoder.
- * Documentation for the disassembler can be found in X86Disassembler.h.
- *
- *===----------------------------------------------------------------------===*/
+//===-- X86DisassemblerDecoder.c - Disassembler decoder -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is part of the X86 Disassembler.
+// It contains the implementation of the instruction decoder.
+// Documentation for the disassembler can be found in X86Disassembler.h.
+//
+//===----------------------------------------------------------------------===//
 
 #include <stdarg.h>   /* for va_*()       */
 #include <stdio.h>    /* for vsnprintf()  */
@@ -20,13 +20,35 @@
 
 #include "X86DisassemblerDecoder.h"
 
-#include "X86GenDisassemblerTables.inc"
+using namespace llvm::X86Disassembler;
+
+/// Specifies whether a ModR/M byte is needed and (if so) which
+/// instruction each possible value of the ModR/M byte corresponds to.  Once
+/// this information is known, we have narrowed down to a single instruction.
+struct ModRMDecision {
+  uint8_t modrm_type;
+  uint16_t instructionIDs;
+};
+
+/// Specifies which set of ModR/M->instruction tables to look at
+/// given a particular opcode.
+struct OpcodeDecision {
+  ModRMDecision modRMDecisions[256];
+};
+
+/// Specifies which opcode->instruction tables to look at given
+/// a particular context (set of attributes).  Since there are many possible
+/// contexts, the decoder first uses CONTEXTS_SYM to determine which context
+/// applies given a specific set of attributes.  Hence there are only IC_max
+/// entries in this table, rather than 2^(ATTR_max).
+struct ContextDecision {
+  OpcodeDecision opcodeDecisions[IC_max];
+};
 
-#define TRUE  1
-#define FALSE 0
+#include "X86GenDisassemblerTables.inc"
 
 #ifndef NDEBUG
-#define debug(s) do { x86DisassemblerDebug(__FILE__, __LINE__, s); } while (0)
+#define debug(s) do { Debug(__FILE__, __LINE__, s); } while (0)
 #else
 #define debug(s) do { } while (0)
 #endif
@@ -41,7 +63,7 @@
  *                    an instruction with these attributes.
  */
 static InstructionContext contextForAttrs(uint16_t attrMask) {
-  return CONTEXTS_SYM[attrMask];
+  return static_cast<InstructionContext>(CONTEXTS_SYM[attrMask]);
 }
 
 /*
@@ -53,12 +75,12 @@ static InstructionContext contextForAttrs(uint16_t attrMask) {
  *                      contextForAttrs.
  * @param opcode      - The last byte of the instruction's opcode, not counting
  *                      ModR/M extensions and escapes.
- * @return            - TRUE if the ModR/M byte is required, FALSE otherwise.
+ * @return            - true if the ModR/M byte is required, false otherwise.
  */
 static int modRMRequired(OpcodeType type,
                          InstructionContext insnContext,
                          uint16_t opcode) {
-  const struct ContextDecision* decision = 0;
+  const struct ContextDecision* decision = nullptr;
 
   switch (type) {
   case ONEBYTE:
@@ -102,7 +124,7 @@ static InstrUID decode(OpcodeType type,
                        InstructionContext insnContext,
                        uint8_t opcode,
                        uint8_t modRM) {
-  const struct ModRMDecision* dec = 0;
+  const struct ModRMDecision* dec = nullptr;
 
   switch (type) {
   case ONEBYTE:
@@ -284,15 +306,15 @@ static void setPrefixPresent(struct InternalInstruction* insn,
  * @param location  - The location to query.
  * @return          - Whether the prefix is at that location.
  */
-static BOOL isPrefixAtLocation(struct InternalInstruction* insn,
+static bool isPrefixAtLocation(struct InternalInstruction* insn,
                                uint8_t prefix,
                                uint64_t location)
 {
   if (insn->prefixPresent[prefix] == 1 &&
      insn->prefixLocations[prefix] == location)
-    return TRUE;
+    return true;
   else
-    return FALSE;
+    return false;
 }
 
 /*
@@ -305,14 +327,14 @@ static BOOL isPrefixAtLocation(struct InternalInstruction* insn,
  *                bytes, and no prefixes conflicted; nonzero otherwise.
  */
 static int readPrefixes(struct InternalInstruction* insn) {
-  BOOL isPrefix = TRUE;
-  BOOL prefixGroups[4] = { FALSE };
+  bool isPrefix = true;
+  bool prefixGroups[4] = { false };
   uint64_t prefixLocation;
   uint8_t byte = 0;
   uint8_t nextByte;
 
-  BOOL hasAdSize = FALSE;
-  BOOL hasOpSize = FALSE;
+  bool hasAdSize = false;
+  bool hasOpSize = false;
 
   dbgprintf(insn, "readPrefixes()");
 
@@ -344,7 +366,7 @@ static int readPrefixes(struct InternalInstruction* insn) {
       if ((byte == 0xf2 || byte == 0xf3) &&
           ((nextByte == 0xf0) |
           ((nextByte & 0xfe) == 0x86 || (nextByte & 0xf8) == 0x90)))
-        insn->xAcquireRelease = TRUE;
+        insn->xAcquireRelease = true;
       /*
        * Also if the byte is 0xf3, and the following condition is met:
        * - it is followed by a "mov mem, reg" (opcode 0x88/0x89) or
@@ -354,7 +376,7 @@ static int readPrefixes(struct InternalInstruction* insn) {
       if (byte == 0xf3 &&
           (nextByte == 0x88 || nextByte == 0x89 ||
            nextByte == 0xc6 || nextByte == 0xc7))
-        insn->xAcquireRelease = TRUE;
+        insn->xAcquireRelease = true;
       if (insn->mode == MODE_64BIT && (nextByte & 0xf0) == 0x40) {
         if (consumeByte(insn, &nextByte))
           return -1;
@@ -372,7 +394,7 @@ static int readPrefixes(struct InternalInstruction* insn) {
     case 0xf3:  /* REP or REPE/REPZ */
       if (prefixGroups[0])
         dbgprintf(insn, "Redundant Group 1 prefix");
-      prefixGroups[0] = TRUE;
+      prefixGroups[0] = true;
       setPrefixPresent(insn, byte, prefixLocation);
       break;
     case 0x2e:  /* CS segment override -OR- Branch not taken */
@@ -406,25 +428,25 @@ static int readPrefixes(struct InternalInstruction* insn) {
       }
       if (prefixGroups[1])
         dbgprintf(insn, "Redundant Group 2 prefix");
-      prefixGroups[1] = TRUE;
+      prefixGroups[1] = true;
       setPrefixPresent(insn, byte, prefixLocation);
       break;
     case 0x66:  /* Operand-size override */
       if (prefixGroups[2])
         dbgprintf(insn, "Redundant Group 3 prefix");
-      prefixGroups[2] = TRUE;
-      hasOpSize = TRUE;
+      prefixGroups[2] = true;
+      hasOpSize = true;
       setPrefixPresent(insn, byte, prefixLocation);
       break;
     case 0x67:  /* Address-size override */
       if (prefixGroups[3])
         dbgprintf(insn, "Redundant Group 4 prefix");
-      prefixGroups[3] = TRUE;
-      hasAdSize = TRUE;
+      prefixGroups[3] = true;
+      hasAdSize = true;
       setPrefixPresent(insn, byte, prefixLocation);
       break;
     default:    /* Not a prefix byte */
-      isPrefix = FALSE;
+      isPrefix = false;
       break;
     }
 
@@ -549,7 +571,7 @@ static int readPrefixes(struct InternalInstruction* insn) {
       default:
         break;
       case VEX_PREFIX_66:
-        hasOpSize = TRUE;
+        hasOpSize = true;
         break;
       }
 
@@ -595,7 +617,7 @@ static int readPrefixes(struct InternalInstruction* insn) {
       default:
         break;
       case VEX_PREFIX_66:
-        hasOpSize = TRUE;
+        hasOpSize = true;
         break;
       }
 
@@ -790,11 +812,9 @@ static int readModRM(struct InternalInstruction* insn);
 static int getIDWithAttrMask(uint16_t* instructionID,
                              struct InternalInstruction* insn,
                              uint16_t attrMask) {
-  BOOL hasModRMExtension;
-
-  uint16_t instructionClass;
+  bool hasModRMExtension;
 
-  instructionClass = contextForAttrs(attrMask);
+  InstructionContext instructionClass = contextForAttrs(attrMask);
 
   hasModRMExtension = modRMRequired(insn->opcodeType,
                                     instructionClass,
@@ -825,14 +845,14 @@ static int getIDWithAttrMask(uint16_t* instructionID,
  * @param orig  - The instruction that is not 16-bit
  * @param equiv - The instruction that is 16-bit
  */
-static BOOL is16BitEquivalent(const char* orig, const char* equiv) {
+static bool is16BitEquivalent(const char* orig, const char* equiv) {
   off_t i;
 
   for (i = 0;; i++) {
     if (orig[i] == '\0' && equiv[i] == '\0')
-      return TRUE;
+      return true;
     if (orig[i] == '\0' || equiv[i] == '\0')
-      return FALSE;
+      return false;
     if (orig[i] != equiv[i]) {
       if ((orig[i] == 'Q' || orig[i] == 'L') && equiv[i] == 'W')
         continue;
@@ -840,7 +860,7 @@ static BOOL is16BitEquivalent(const char* orig, const char* equiv) {
         continue;
       if ((orig[i] == '4' || orig[i] == '2') && equiv[i] == '6')
         continue;
-      return FALSE;
+      return false;
     }
   }
 }
@@ -1011,9 +1031,8 @@ static int getID(struct InternalInstruction* insn, const void *miiArg) {
       return 0;
     }
 
-    specName = x86DisassemblerGetInstrName(instructionID, miiArg);
-    specWithOpSizeName =
-      x86DisassemblerGetInstrName(instructionIDWithOpsize, miiArg);
+    specName = GetInstrName(instructionID, miiArg);
+    specWithOpSizeName = GetInstrName(instructionIDWithOpsize, miiArg);
 
     if (is16BitEquivalent(specName, specWithOpSizeName) &&
         (insn->mode == MODE_16BIT) ^ insn->prefixPresent[0x66]) {
@@ -1077,8 +1096,8 @@ static int getID(struct InternalInstruction* insn, const void *miiArg) {
  * @return      - 0 if the SIB byte was successfully read; nonzero otherwise.
  */
 static int readSIB(struct InternalInstruction* insn) {
-  SIBIndex sibIndexBase = 0;
-  SIBBase sibBaseBase = 0;
+  SIBIndex sibIndexBase = SIB_INDEX_NONE;
+  SIBBase sibBaseBase = SIB_BASE_NONE;
   uint8_t index, base;
 
   dbgprintf(insn, "readSIB()");
@@ -1086,7 +1105,7 @@ static int readSIB(struct InternalInstruction* insn) {
   if (insn->consumedSIB)
     return 0;
 
-  insn->consumedSIB = TRUE;
+  insn->consumedSIB = true;
 
   switch (insn->addressSize) {
   case 2:
@@ -1184,12 +1203,12 @@ static int readDisplacement(struct InternalInstruction* insn) {
   if (insn->consumedDisplacement)
     return 0;
 
-  insn->consumedDisplacement = TRUE;
+  insn->consumedDisplacement = true;
   insn->displacementOffset = insn->readerCursor - insn->startLocation;
 
   switch (insn->eaDisplacement) {
   case EA_DISP_NONE:
-    insn->consumedDisplacement = FALSE;
+    insn->consumedDisplacement = false;
     break;
   case EA_DISP_8:
     if (consumeInt8(insn, &d8))
@@ -1208,7 +1227,7 @@ static int readDisplacement(struct InternalInstruction* insn) {
     break;
   }
 
-  insn->consumedDisplacement = TRUE;
+  insn->consumedDisplacement = true;
   return 0;
 }
 
@@ -1229,7 +1248,7 @@ static int readModRM(struct InternalInstruction* insn) {
 
   if (consumeByte(insn, &insn->modRM))
     return -1;
-  insn->consumedModRM = TRUE;
+  insn->consumedModRM = true;
 
   mod     = modFromModRM(insn->modRM);
   rm      = rmFromModRM(insn->modRM);
@@ -1599,20 +1618,22 @@ static int readImmediate(struct InternalInstruction* insn, uint8_t size) {
 static int readVVVV(struct InternalInstruction* insn) {
   dbgprintf(insn, "readVVVV()");
 
+  int vvvv;
   if (insn->vectorExtensionType == TYPE_EVEX)
-    insn->vvvv = vvvvFromEVEX3of4(insn->vectorExtensionPrefix[2]);
+    vvvv = vvvvFromEVEX3of4(insn->vectorExtensionPrefix[2]);
   else if (insn->vectorExtensionType == TYPE_VEX_3B)
-    insn->vvvv = vvvvFromVEX3of3(insn->vectorExtensionPrefix[2]);
+    vvvv = vvvvFromVEX3of3(insn->vectorExtensionPrefix[2]);
   else if (insn->vectorExtensionType == TYPE_VEX_2B)
-    insn->vvvv = vvvvFromVEX2of2(insn->vectorExtensionPrefix[1]);
+    vvvv = vvvvFromVEX2of2(insn->vectorExtensionPrefix[1]);
   else if (insn->vectorExtensionType == TYPE_XOP)
-    insn->vvvv = vvvvFromXOP3of3(insn->vectorExtensionPrefix[2]);
+    vvvv = vvvvFromXOP3of3(insn->vectorExtensionPrefix[2]);
   else
     return -1;
 
   if (insn->mode != MODE_64BIT)
-    insn->vvvv &= 0x7;
+    vvvv &= 0x7;
 
+  insn->vvvv = static_cast<Reg>(vvvv);
   return 0;
 }
 
@@ -1629,7 +1650,8 @@ static int readMaskRegister(struct InternalInstruction* insn) {
   if (insn->vectorExtensionType != TYPE_EVEX)
     return -1;
 
-  insn->writemask = aaaFromEVEX4of4(insn->vectorExtensionPrefix[3]);
+  insn->writemask =
+      static_cast<Reg>(aaaFromEVEX4of4(insn->vectorExtensionPrefix[3]));
   return 0;
 }
 
@@ -1641,7 +1663,6 @@ static int readMaskRegister(struct InternalInstruction* insn) {
  * @return      - 0 if all operands could be read; nonzero otherwise.
  */
 static int readOperands(struct InternalInstruction* insn) {
-  int index;
   int hasVVVV, needVVVV;
   int sawRegImm = 0;
 
@@ -1652,8 +1673,8 @@ static int readOperands(struct InternalInstruction* insn) {
   hasVVVV = !readVVVV(insn);
   needVVVV = hasVVVV && (insn->vvvv != 0);
 
-  for (index = 0; index < X86_MAX_OPERANDS; ++index) {
-    switch (x86OperandSets[insn->spec->operands][index].encoding) {
+  for (const auto &Op : x86OperandSets[insn->spec->operands]) {
+    switch (Op.encoding) {
     case ENCODING_NONE:
     case ENCODING_SI:
     case ENCODING_DI:
@@ -1662,7 +1683,7 @@ static int readOperands(struct InternalInstruction* insn) {
     case ENCODING_RM:
       if (readModRM(insn))
         return -1;
-      if (fixupReg(insn, &x86OperandSets[insn->spec->operands][index]))
+      if (fixupReg(insn, &Op))
         return -1;
       break;
     case ENCODING_CB:
@@ -1684,14 +1705,14 @@ static int readOperands(struct InternalInstruction* insn) {
       }
       if (readImmediate(insn, 1))
         return -1;
-      if (x86OperandSets[insn->spec->operands][index].type == TYPE_IMM3 &&
+      if (Op.type == TYPE_IMM3 &&
           insn->immediates[insn->numImmediatesConsumed - 1] > 7)
         return -1;
-      if (x86OperandSets[insn->spec->operands][index].type == TYPE_IMM5 &&
+      if (Op.type == TYPE_IMM5 &&
           insn->immediates[insn->numImmediatesConsumed - 1] > 31)
         return -1;
-      if (x86OperandSets[insn->spec->operands][index].type == TYPE_XMM128 ||
-          x86OperandSets[insn->spec->operands][index].type == TYPE_XMM256)
+      if (Op.type == TYPE_XMM128 ||
+          Op.type == TYPE_XMM256)
         sawRegImm = 1;
       break;
     case ENCODING_IW:
@@ -1740,7 +1761,7 @@ static int readOperands(struct InternalInstruction* insn) {
       needVVVV = 0; /* Mark that we have found a VVVV operand. */
       if (!hasVVVV)
         return -1;
-      if (fixupReg(insn, &x86OperandSets[insn->spec->operands][index]))
+      if (fixupReg(insn, &Op))
         return -1;
       break;
     case ENCODING_WRITEMASK:
@@ -1781,14 +1802,10 @@ static int readOperands(struct InternalInstruction* insn) {
  * @return          - 0 if the instruction's memory could be read; nonzero if
  *                    not.
  */
-int decodeInstruction(struct InternalInstruction* insn,
-                      byteReader_t reader,
-                      const void* readerArg,
-                      dlog_t logger,
-                      void* loggerArg,
-                      const void* miiArg,
-                      uint64_t startLoc,
-                      DisassemblerMode mode) {
+int llvm::X86Disassembler::decodeInstruction(
+    struct InternalInstruction *insn, byteReader_t reader,
+    const void *readerArg, dlog_t logger, void *loggerArg, const void *miiArg,
+    uint64_t startLoc, DisassemblerMode mode) {
   memset(insn, 0, sizeof(struct InternalInstruction));
 
   insn->reader = reader;
@@ -1807,7 +1824,7 @@ int decodeInstruction(struct InternalInstruction* insn,
       readOperands(insn))
     return -1;
 
-  insn->operands = &x86OperandSets[insn->spec->operands][0];
+  insn->operands = x86OperandSets[insn->spec->operands];
 
   insn->length = insn->readerCursor - insn->startLocation;
 
diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h
index ac3b39d..8c45402 100644
--- a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h
+++ b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h
@@ -1,39 +1,28 @@
-/*===-- X86DisassemblerDecoderInternal.h - Disassembler decoder ---*- C -*-===*
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is distributed under the University of Illinois Open Source
- * License. See LICENSE.TXT for details.
- *
- *===----------------------------------------------------------------------===*
- *
- * This file is part of the X86 Disassembler.
- * It contains the public interface of the instruction decoder.
- * Documentation for the disassembler can be found in X86Disassembler.h.
- *
- *===----------------------------------------------------------------------===*/
+//===-- X86DisassemblerDecoderInternal.h - Disassembler decoder -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is part of the X86 Disassembler.
+// It contains the public interface of the instruction decoder.
+// Documentation for the disassembler can be found in X86Disassembler.h.
+//
+//===----------------------------------------------------------------------===//
 
 #ifndef X86DISASSEMBLERDECODER_H
 #define X86DISASSEMBLERDECODER_H
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#define INSTRUCTION_SPECIFIER_FIELDS \
-  uint16_t operands;
-
-#define INSTRUCTION_IDS     \
-  uint16_t instructionIDs;
-
 #include "X86DisassemblerDecoderCommon.h"
+#include "llvm/ADT/ArrayRef.h"
 
-#undef INSTRUCTION_SPECIFIER_FIELDS
-#undef INSTRUCTION_IDS
+namespace llvm {
+namespace X86Disassembler {
 
-/*
- * Accessor functions for various fields of an Intel instruction
- */
+// Accessor functions for various fields of an Intel instruction
 #define modFromModRM(modRM)  (((modRM) & 0xc0) >> 6)
 #define regFromModRM(modRM)  (((modRM) & 0x38) >> 3)
 #define rmFromModRM(modRM)   ((modRM) & 0x7)
@@ -83,10 +72,7 @@ extern "C" {
 #define lFromXOP3of3(xop)       (((xop) & 0x4) >> 2)
 #define ppFromXOP3of3(xop)      ((xop) & 0x3)
 
-/*
- * These enums represent Intel registers for use by the decoder.
- */
-
+// These enums represent Intel registers for use by the decoder.
 #define REGS_8BIT     \
   ENTRY(AL)           \
   ENTRY(CL)           \
@@ -392,13 +378,11 @@ extern "C" {
   REGS_CONTROL        \
   ENTRY(RIP)
 
-/*
- * EABase - All possible values of the base field for effective-address
- *   computations, a.k.a. the Mod and R/M fields of the ModR/M byte.  We
- *   distinguish between bases (EA_BASE_*) and registers that just happen to be
- *   referred to when Mod == 0b11 (EA_REG_*).
- */
-typedef enum {
+/// \brief All possible values of the base field for effective-address
+/// computations, a.k.a. the Mod and R/M fields of the ModR/M byte.
+/// We distinguish between bases (EA_BASE_*) and registers that just happen
+/// to be referred to when Mod == 0b11 (EA_REG_*).
+enum EABase {
   EA_BASE_NONE,
 #define ENTRY(x) EA_BASE_##x,
   ALL_EA_BASES
@@ -407,15 +391,13 @@ typedef enum {
   ALL_REGS
 #undef ENTRY
   EA_max
-} EABase;
-
-/*
- * SIBIndex - All possible values of the SIB index field.
- *   Borrows entries from ALL_EA_BASES with the special case that
- *   sib is synonymous with NONE.
- * Vector SIB: index can be XMM or YMM.
- */
-typedef enum {
+};
+
+/// \brief All possible values of the SIB index field.
+/// borrows entries from ALL_EA_BASES with the special case that
+/// sib is synonymous with NONE.
+/// Vector SIB: index can be XMM or YMM.
+enum SIBIndex {
   SIB_INDEX_NONE,
 #define ENTRY(x) SIB_INDEX_##x,
   ALL_EA_BASES
@@ -424,23 +406,18 @@ typedef enum {
   REGS_ZMM
 #undef ENTRY
   SIB_INDEX_max
-} SIBIndex;
+};
 
-/*
- * SIBBase - All possible values of the SIB base field.
- */
-typedef enum {
+/// \brief All possible values of the SIB base field.
+enum SIBBase {
   SIB_BASE_NONE,
 #define ENTRY(x) SIB_BASE_##x,
   ALL_SIB_BASES
 #undef ENTRY
   SIB_BASE_max
-} SIBBase;
+};
 
-/*
- * EADisplacement - Possible displacement types for effective-address
- *   computations.
- */
+/// \brief Possible displacement types for effective-address computations.
 typedef enum {
   EA_DISP_NONE,
   EA_DISP_8,
@@ -448,20 +425,16 @@ typedef enum {
   EA_DISP_32
 } EADisplacement;
 
-/*
- * Reg - All possible values of the reg field in the ModR/M byte.
- */
-typedef enum {
+/// \brief All possible values of the reg field in the ModR/M byte.
+enum Reg {
 #define ENTRY(x) MODRM_REG_##x,
   ALL_REGS
 #undef ENTRY
   MODRM_REG_max
-} Reg;
+};
 
-/*
- * SegmentOverride - All possible segment overrides.
- */
-typedef enum {
+/// \brief All possible segment overrides.
+enum SegmentOverride {
   SEG_OVERRIDE_NONE,
   SEG_OVERRIDE_CS,
   SEG_OVERRIDE_SS,
@@ -470,235 +443,220 @@ typedef enum {
   SEG_OVERRIDE_FS,
   SEG_OVERRIDE_GS,
   SEG_OVERRIDE_max
-} SegmentOverride;
-
-/*
- * VEXLeadingOpcodeByte - Possible values for the VEX.m-mmmm field
- */
+};
 
-typedef enum {
+/// \brief Possible values for the VEX.m-mmmm field
+enum VEXLeadingOpcodeByte {
   VEX_LOB_0F = 0x1,
   VEX_LOB_0F38 = 0x2,
   VEX_LOB_0F3A = 0x3
-} VEXLeadingOpcodeByte;
+};
 
-typedef enum {
+enum XOPMapSelect {
   XOP_MAP_SELECT_8 = 0x8,
   XOP_MAP_SELECT_9 = 0x9,
   XOP_MAP_SELECT_A = 0xA
-} XOPMapSelect;
-
-/*
- * VEXPrefixCode - Possible values for the VEX.pp/EVEX.pp field
- */
+};
 
-typedef enum {
+/// \brief Possible values for the VEX.pp/EVEX.pp field
+enum VEXPrefixCode {
   VEX_PREFIX_NONE = 0x0,
   VEX_PREFIX_66 = 0x1,
   VEX_PREFIX_F3 = 0x2,
   VEX_PREFIX_F2 = 0x3
-} VEXPrefixCode;
+};
 
-typedef enum {
+enum VectorExtensionType {
   TYPE_NO_VEX_XOP   = 0x0,
   TYPE_VEX_2B       = 0x1,
   TYPE_VEX_3B       = 0x2,
   TYPE_EVEX         = 0x3,
   TYPE_XOP          = 0x4
-} VectorExtensionType;
-
-typedef uint8_t BOOL;
-
-/*
- * byteReader_t - Type for the byte reader that the consumer must provide to
- *   the decoder.  Reads a single byte from the instruction's address space.
- * @param arg     - A baton that the consumer can associate with any internal
- *                  state that it needs.
- * @param byte    - A pointer to a single byte in memory that should be set to
- *                  contain the value at address.
- * @param address - The address in the instruction's address space that should
- *                  be read from.
- * @return        - -1 if the byte cannot be read for any reason; 0 otherwise.
- */
-typedef int (*byteReader_t)(const void* arg, uint8_t* byte, uint64_t address);
-
-/*
- * dlog_t - Type for the logging function that the consumer can provide to
- *   get debugging output from the decoder.
- * @param arg     - A baton that the consumer can associate with any internal
- *                  state that it needs.
- * @param log     - A string that contains the message.  Will be reused after
- *                  the logger returns.
- */
-typedef void (*dlog_t)(void* arg, const char *log);
-
-/*
- * The x86 internal instruction, which is produced by the decoder.
- */
+};
+
+/// \brief Type for the byte reader that the consumer must provide to
+/// the decoder. Reads a single byte from the instruction's address space.
+/// \param arg     A baton that the consumer can associate with any internal
+///                state that it needs.
+/// \param byte    A pointer to a single byte in memory that should be set to
+///                contain the value at address.
+/// \param address The address in the instruction's address space that should
+///                be read from.
+/// \return        -1 if the byte cannot be read for any reason; 0 otherwise.
+typedef int (*byteReader_t)(const void *arg, uint8_t *byte, uint64_t address);
+
+/// \brief Type for the logging function that the consumer can provide to
+/// get debugging output from the decoder.
+/// \param arg A baton that the consumer can associate with any internal
+///            state that it needs.
+/// \param log A string that contains the message.  Will be reused after
+///            the logger returns.
+typedef void (*dlog_t)(void *arg, const char *log);
+
+/// The specification for how to extract and interpret a full instruction and
+/// its operands.
+struct InstructionSpecifier {
+  uint16_t operands;
+};
+
+/// The x86 internal instruction, which is produced by the decoder.
 struct InternalInstruction {
-  /* Reader interface (C) */
+  // Reader interface (C)
   byteReader_t reader;
-  /* Opaque value passed to the reader */
+  // Opaque value passed to the reader
   const void* readerArg;
-  /* The address of the next byte to read via the reader */
+  // The address of the next byte to read via the reader
   uint64_t readerCursor;
 
-  /* Logger interface (C) */
+  // Logger interface (C)
   dlog_t dlog;
-  /* Opaque value passed to the logger */
+  // Opaque value passed to the logger
   void* dlogArg;
 
-  /* General instruction information */
+  // General instruction information
 
-  /* The mode to disassemble for (64-bit, protected, real) */
+  // The mode to disassemble for (64-bit, protected, real)
   DisassemblerMode mode;
-  /* The start of the instruction, usable with the reader */
+  // The start of the instruction, usable with the reader
   uint64_t startLocation;
-  /* The length of the instruction, in bytes */
+  // The length of the instruction, in bytes
   size_t length;
 
-  /* Prefix state */
+  // Prefix state
 
-  /* 1 if the prefix byte corresponding to the entry is present; 0 if not */
+  // 1 if the prefix byte corresponding to the entry is present; 0 if not
   uint8_t prefixPresent[0x100];
-  /* contains the location (for use with the reader) of the prefix byte */
+  // contains the location (for use with the reader) of the prefix byte
   uint64_t prefixLocations[0x100];
-  /* The value of the vector extension prefix(EVEX/VEX/XOP), if present */
+  // The value of the vector extension prefix(EVEX/VEX/XOP), if present
   uint8_t vectorExtensionPrefix[4];
-  /* The type of the vector extension prefix */
+  // The type of the vector extension prefix
   VectorExtensionType vectorExtensionType;
-  /* The value of the REX prefix, if present */
+  // The value of the REX prefix, if present
   uint8_t rexPrefix;
-  /* The location where a mandatory prefix would have to be (i.e., right before
-     the opcode, or right before the REX prefix if one is present) */
+  // The location where a mandatory prefix would have to be (i.e., right before
+  // the opcode, or right before the REX prefix if one is present).
   uint64_t necessaryPrefixLocation;
-  /* The segment override type */
+  // The segment override type
   SegmentOverride segmentOverride;
-  /* 1 if the prefix byte, 0xf2 or 0xf3 is xacquire or xrelease */
-  BOOL xAcquireRelease;
+  // 1 if the prefix byte, 0xf2 or 0xf3 is xacquire or xrelease
+  bool xAcquireRelease;
 
-  /* Sizes of various critical pieces of data, in bytes */
+  // Sizes of various critical pieces of data, in bytes
   uint8_t registerSize;
   uint8_t addressSize;
   uint8_t displacementSize;
   uint8_t immediateSize;
 
-  /* Offsets from the start of the instruction to the pieces of data, which is
-     needed to find relocation entries for adding symbolic operands */
+  // Offsets from the start of the instruction to the pieces of data, which is
+  // needed to find relocation entries for adding symbolic operands.
   uint8_t displacementOffset;
   uint8_t immediateOffset;
 
-  /* opcode state */
+  // opcode state
 
-  /* The last byte of the opcode, not counting any ModR/M extension */
+  // The last byte of the opcode, not counting any ModR/M extension
   uint8_t opcode;
-  /* The ModR/M byte of the instruction, if it is an opcode extension */
+  // The ModR/M byte of the instruction, if it is an opcode extension
   uint8_t modRMExtension;
 
-  /* decode state */
+  // decode state
 
-  /* The type of opcode, used for indexing into the array of decode tables */
+  // The type of opcode, used for indexing into the array of decode tables
   OpcodeType opcodeType;
-  /* The instruction ID, extracted from the decode table */
+  // The instruction ID, extracted from the decode table
   uint16_t instructionID;
-  /* The specifier for the instruction, from the instruction info table */
-  const struct InstructionSpecifier *spec;
+  // The specifier for the instruction, from the instruction info table
+  const InstructionSpecifier *spec;
 
-  /* state for additional bytes, consumed during operand decode.  Pattern:
-     consumed___ indicates that the byte was already consumed and does not
-     need to be consumed again */
+  // state for additional bytes, consumed during operand decode.  Pattern:
+  // consumed___ indicates that the byte was already consumed and does not
+  // need to be consumed again.
 
-  /* The VEX.vvvv field, which contains a third register operand for some AVX
-     instructions */
+  // The VEX.vvvv field, which contains a third register operand for some AVX
+  // instructions.
   Reg                           vvvv;
 
-  /* The writemask for AVX-512 instructions which is contained in EVEX.aaa */
+  // The writemask for AVX-512 instructions which is contained in EVEX.aaa
   Reg                           writemask;
 
-  /* The ModR/M byte, which contains most register operands and some portion of
-     all memory operands */
-  BOOL                          consumedModRM;
+  // The ModR/M byte, which contains most register operands and some portion of
+  // all memory operands.
+  bool                          consumedModRM;
   uint8_t                       modRM;
 
-  /* The SIB byte, used for more complex 32- or 64-bit memory operands */
-  BOOL                          consumedSIB;
+  // The SIB byte, used for more complex 32- or 64-bit memory operands
+  bool                          consumedSIB;
   uint8_t                       sib;
 
-  /* The displacement, used for memory operands */
-  BOOL                          consumedDisplacement;
+  // The displacement, used for memory operands
+  bool                          consumedDisplacement;
   int32_t                       displacement;
 
-  /* Immediates.  There can be two in some cases */
+  // Immediates.  There can be two in some cases
   uint8_t                       numImmediatesConsumed;
   uint8_t                       numImmediatesTranslated;
   uint64_t                      immediates[2];
 
-  /* A register or immediate operand encoded into the opcode */
+  // A register or immediate operand encoded into the opcode
   Reg                           opcodeRegister;
 
-  /* Portions of the ModR/M byte */
+  // Portions of the ModR/M byte
 
-  /* These fields determine the allowable values for the ModR/M fields, which
-     depend on operand and address widths */
+  // These fields determine the allowable values for the ModR/M fields, which
+  // depend on operand and address widths.
   EABase                        eaBaseBase;
   EABase                        eaRegBase;
   Reg                           regBase;
 
-  /* The Mod and R/M fields can encode a base for an effective address, or a
-     register.  These are separated into two fields here */
+  // The Mod and R/M fields can encode a base for an effective address, or a
+  // register.  These are separated into two fields here.
   EABase                        eaBase;
   EADisplacement                eaDisplacement;
-  /* The reg field always encodes a register */
+  // The reg field always encodes a register
   Reg                           reg;
 
-  /* SIB state */
+  // SIB state
   SIBIndex                      sibIndex;
   uint8_t                       sibScale;
   SIBBase                       sibBase;
 
-  const struct OperandSpecifier *operands;
+  ArrayRef<OperandSpecifier> operands;
 };
 
-/* decodeInstruction - Decode one instruction and store the decoding results in
- *   a buffer provided by the consumer.
- * @param insn      - The buffer to store the instruction in.  Allocated by the
- *                    consumer.
- * @param reader    - The byteReader_t for the bytes to be read.
- * @param readerArg - An argument to pass to the reader for storing context
- *                    specific to the consumer.  May be NULL.
- * @param logger    - The dlog_t to be used in printing status messages from the
- *                    disassembler.  May be NULL.
- * @param loggerArg - An argument to pass to the logger for storing context
- *                    specific to the logger.  May be NULL.
- * @param startLoc  - The address (in the reader's address space) of the first
- *                    byte in the instruction.
- * @param mode      - The mode (16-bit, 32-bit, 64-bit) to decode in.
- * @return          - Nonzero if there was an error during decode, 0 otherwise.
- */
-int decodeInstruction(struct InternalInstruction* insn,
+/// \brief Decode one instruction and store the decoding results in
+/// a buffer provided by the consumer.
+/// \param insn      The buffer to store the instruction in.  Allocated by the
+///                  consumer.
+/// \param reader    The byteReader_t for the bytes to be read.
+/// \param readerArg An argument to pass to the reader for storing context
+///                  specific to the consumer.  May be NULL.
+/// \param logger    The dlog_t to be used in printing status messages from the
+///                  disassembler.  May be NULL.
+/// \param loggerArg An argument to pass to the logger for storing context
+///                  specific to the logger.  May be NULL.
+/// \param startLoc  The address (in the reader's address space) of the first
+///                  byte in the instruction.
+/// \param mode      The mode (16-bit, 32-bit, 64-bit) to decode in.
+/// \return          Nonzero if there was an error during decode, 0 otherwise.
+int decodeInstruction(InternalInstruction *insn,
                       byteReader_t reader,
-                      const void* readerArg,
+                      const void *readerArg,
                       dlog_t logger,
-                      void* loggerArg,
-                      const void* miiArg,
+                      void *loggerArg,
+                      const void *miiArg,
                       uint64_t startLoc,
                       DisassemblerMode mode);
 
-/* x86DisassemblerDebug - C-accessible function for printing a message to
- *   debugs()
- * @param file  - The name of the file printing the debug message.
- * @param line  - The line number that printed the debug message.
- * @param s     - The message to print.
- */
+/// \brief Print a message to debugs()
+/// \param file The name of the file printing the debug message.
+/// \param line The line number that printed the debug message.
+/// \param s    The message to print.
+void Debug(const char *file, unsigned line, const char *s);
 
-void x86DisassemblerDebug(const char *file,
-                          unsigned line,
-                          const char *s);
+const char *GetInstrName(unsigned Opcode, const void *mii);
 
-const char *x86DisassemblerGetInstrName(unsigned Opcode, const void *mii);
-
-#ifdef __cplusplus
-}
-#endif
+} // namespace X86Disassembler
+} // namespace llvm
 
 #endif
diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h b/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h
index 523ae99..f59e0b6 100644
--- a/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h
+++ b/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h
@@ -1,29 +1,27 @@
-/*===-- X86DisassemblerDecoderCommon.h - Disassembler decoder -----*- C -*-===*
- *
- *                     The LLVM Compiler Infrastructure
- *
- * This file is distributed under the University of Illinois Open Source
- * License. See LICENSE.TXT for details.
- *
- *===----------------------------------------------------------------------===*
- *
- * This file is part of the X86 Disassembler.
- * It contains common definitions used by both the disassembler and the table
- *  generator.
- * Documentation for the disassembler can be found in X86Disassembler.h.
- *
- *===----------------------------------------------------------------------===*/
-
-/*
- * This header file provides those definitions that need to be shared between
- * the decoder and the table generator in a C-friendly manner.
- */
+//===-- X86DisassemblerDecoderCommon.h - Disassembler decoder ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is part of the X86 Disassembler.
+// It contains common definitions used by both the disassembler and the table
+//  generator.
+// Documentation for the disassembler can be found in X86Disassembler.h.
+//
+//===----------------------------------------------------------------------===//
 
 #ifndef X86DISASSEMBLERDECODERCOMMON_H
 #define X86DISASSEMBLERDECODERCOMMON_H
 
 #include "llvm/Support/DataTypes.h"
 
+namespace llvm {
+namespace X86Disassembler {
+
 #define INSTRUCTIONS_SYM  x86DisassemblerInstrSpecifiers
 #define CONTEXTS_SYM      x86DisassemblerContexts
 #define ONEBYTE_SYM       x86DisassemblerOneByteOpcodes
@@ -44,11 +42,9 @@
 #define XOP9_MAP_STR      "x86DisassemblerXOP9Opcodes"
 #define XOPA_MAP_STR      "x86DisassemblerXOPAOpcodes"
 
-/*
- * Attributes of an instruction that must be known before the opcode can be
- * processed correctly.  Most of these indicate the presence of particular
- * prefixes, but ATTR_64BIT is simply an attribute of the decoding context.
- */
+// Attributes of an instruction that must be known before the opcode can be
+// processed correctly.  Most of these indicate the presence of particular
+// prefixes, but ATTR_64BIT is simply an attribute of the decoding context.
 #define ATTRIBUTE_BITS                  \
   ENUM_ENTRY(ATTR_NONE,   0x00)         \
   ENUM_ENTRY(ATTR_64BIT,  (0x1 << 0))   \
@@ -73,13 +69,11 @@ enum attributeBits {
 };
 #undef ENUM_ENTRY
 
-/*
- * Combinations of the above attributes that are relevant to instruction
- * decode. Although other combinations are possible, they can be reduced to
- * these without affecting the ultimately decoded instruction.
- */
+// Combinations of the above attributes that are relevant to instruction
+// decode. Although other combinations are possible, they can be reduced to
+// these without affecting the ultimately decoded instruction.
 
-/*           Class name           Rank  Rationale for rank assignment         */
+//           Class name           Rank  Rationale for rank assignment
 #define INSTRUCTION_CONTEXTS                                                   \
   ENUM_ENTRY(IC,                    0,  "says nothing about the instruction")  \
   ENUM_ENTRY(IC_64BIT,              1,  "says the instruction applies in "     \
@@ -274,17 +268,15 @@ enum attributeBits {
   ENUM_ENTRY(IC_EVEX_L2_W_OPSIZE_KZ, 4,  "requires EVEX_KZ, L2, W and OpSize")     
 
 #define ENUM_ENTRY(n, r, d) n,
-typedef enum {
+enum InstructionContext {
   INSTRUCTION_CONTEXTS
   IC_max
-} InstructionContext;
+};
 #undef ENUM_ENTRY
 
-/*
- * Opcode types, which determine which decode table to use, both in the Intel
- * manual and also for the decoder.
- */
-typedef enum {
+// Opcode types, which determine which decode table to use, both in the Intel
+// manual and also for the decoder.
+enum OpcodeType {
   ONEBYTE       = 0,
   TWOBYTE       = 1,
   THREEBYTE_38  = 2,
@@ -292,39 +284,33 @@ typedef enum {
   XOP8_MAP      = 4,
   XOP9_MAP      = 5,
   XOPA_MAP      = 6
-} OpcodeType;
-
-/*
- * The following structs are used for the hierarchical decode table.  After
- * determining the instruction's class (i.e., which IC_* constant applies to
- * it), the decoder reads the opcode.  Some instructions require specific
- * values of the ModR/M byte, so the ModR/M byte indexes into the final table.
- *
- * If a ModR/M byte is not required, "required" is left unset, and the values
- * for each instructionID are identical.
- */
+};
 
+// The following structs are used for the hierarchical decode table.  After
+// determining the instruction's class (i.e., which IC_* constant applies to
+// it), the decoder reads the opcode.  Some instructions require specific
+// values of the ModR/M byte, so the ModR/M byte indexes into the final table.
+//
+// If a ModR/M byte is not required, "required" is left unset, and the values
+// for each instructionID are identical.
 typedef uint16_t InstrUID;
 
-/*
- * ModRMDecisionType - describes the type of ModR/M decision, allowing the
- * consumer to determine the number of entries in it.
- *
- * MODRM_ONEENTRY - No matter what the value of the ModR/M byte is, the decoded
- *                  instruction is the same.
- * MODRM_SPLITRM  - If the ModR/M byte is between 0x00 and 0xbf, the opcode
- *                  corresponds to one instruction; otherwise, it corresponds to
- *                  a different instruction.
- * MODRM_SPLITMISC- If the ModR/M byte is between 0x00 and 0xbf, ModR/M byte
- *                  divided by 8 is used to select instruction; otherwise, each
- *                  value of the ModR/M byte could correspond to a different
- *                  instruction.
- * MODRM_SPLITREG - ModR/M byte divided by 8 is used to select instruction. This
-                    corresponds to instructions that use reg field as opcode
- * MODRM_FULL     - Potentially, each value of the ModR/M byte could correspond
- *                  to a different instruction.
- */
-
+// ModRMDecisionType - describes the type of ModR/M decision, allowing the
+// consumer to determine the number of entries in it.
+//
+// MODRM_ONEENTRY - No matter what the value of the ModR/M byte is, the decoded
+//                  instruction is the same.
+// MODRM_SPLITRM  - If the ModR/M byte is between 0x00 and 0xbf, the opcode
+//                  corresponds to one instruction; otherwise, it corresponds to
+//                  a different instruction.
+// MODRM_SPLITMISC- If the ModR/M byte is between 0x00 and 0xbf, ModR/M byte
+//                  divided by 8 is used to select instruction; otherwise, each
+//                  value of the ModR/M byte could correspond to a different
+//                  instruction.
+// MODRM_SPLITREG - ModR/M byte divided by 8 is used to select instruction. This
+//                  corresponds to instructions that use reg field as opcode
+// MODRM_FULL     - Potentially, each value of the ModR/M byte could correspond
+//                  to a different instruction.
 #define MODRMTYPES            \
   ENUM_ENTRY(MODRM_ONEENTRY)  \
   ENUM_ENTRY(MODRM_SPLITRM)   \
@@ -333,47 +319,13 @@ typedef uint16_t InstrUID;
   ENUM_ENTRY(MODRM_FULL)
 
 #define ENUM_ENTRY(n) n,
-typedef enum {
+enum ModRMDecisionType {
   MODRMTYPES
   MODRM_max
-} ModRMDecisionType;
-#undef ENUM_ENTRY
-
-/*
- * ModRMDecision - Specifies whether a ModR/M byte is needed and (if so) which
- *  instruction each possible value of the ModR/M byte corresponds to.  Once
- *  this information is known, we have narrowed down to a single instruction.
- */
-struct ModRMDecision {
-  uint8_t     modrm_type;
-
-  /* The macro below must be defined wherever this file is included. */
-  INSTRUCTION_IDS
-};
-
-/*
- * OpcodeDecision - Specifies which set of ModR/M->instruction tables to look at
- *   given a particular opcode.
- */
-struct OpcodeDecision {
-  struct ModRMDecision modRMDecisions[256];
-};
-
-/*
- * ContextDecision - Specifies which opcode->instruction tables to look at given
- *   a particular context (set of attributes).  Since there are many possible
- *   contexts, the decoder first uses CONTEXTS_SYM to determine which context
- *   applies given a specific set of attributes.  Hence there are only IC_max
- *   entries in this table, rather than 2^(ATTR_max).
- */
-struct ContextDecision {
-  struct OpcodeDecision opcodeDecisions[IC_max];
 };
+#undef ENUM_ENTRY
 
-/*
- * Physical encodings of instruction operands.
- */
-
+// Physical encodings of instruction operands.
 #define ENCODINGS                                                              \
   ENUM_ENTRY(ENCODING_NONE,   "")                                              \
   ENUM_ENTRY(ENCODING_REG,    "Register operand in ModR/M byte.")              \
@@ -408,16 +360,13 @@ struct ContextDecision {
   ENUM_ENTRY(ENCODING_DI,     "Destination index; encoded in prefixes")
 
 #define ENUM_ENTRY(n, d) n,
-  typedef enum {
-    ENCODINGS
-    ENCODING_max
-  } OperandEncoding;
+enum OperandEncoding {
+  ENCODINGS
+  ENCODING_max
+};
 #undef ENUM_ENTRY
 
-/*
- * Semantic interpretations of instruction operands.
- */
-
+// Semantic interpretations of instruction operands.
 #define TYPES                                                                  \
   ENUM_ENTRY(TYPE_NONE,       "")                                              \
   ENUM_ENTRY(TYPE_REL8,       "1-byte immediate address")                      \
@@ -508,56 +457,42 @@ struct ContextDecision {
   ENUM_ENTRY(TYPE_M512,       "512-bit FPU/MMX/XMM/MXCSR state")
 
 #define ENUM_ENTRY(n, d) n,
-typedef enum {
+enum OperandType {
   TYPES
   TYPE_max
-} OperandType;
+};
 #undef ENUM_ENTRY
 
-/*
- * OperandSpecifier - The specification for how to extract and interpret one
- *   operand.
- */
+/// \brief The specification for how to extract and interpret one operand.
 struct OperandSpecifier {
   uint8_t encoding;
   uint8_t type;
 };
 
-/*
- * Indicates where the opcode modifier (if any) is to be found.  Extended
- * opcodes with AddRegFrm have the opcode modifier in the ModR/M byte.
- */
-
+// Indicates where the opcode modifier (if any) is to be found.  Extended
+// opcodes with AddRegFrm have the opcode modifier in the ModR/M byte.
 #define MODIFIER_TYPES        \
   ENUM_ENTRY(MODIFIER_NONE)
 
 #define ENUM_ENTRY(n) n,
-typedef enum {
+enum ModifierType {
   MODIFIER_TYPES
   MODIFIER_max
-} ModifierType;
+};
 #undef ENUM_ENTRY
 
-#define X86_MAX_OPERANDS 5
-
-/*
- * The specification for how to extract and interpret a full instruction and
- * its operands.
- */
-struct InstructionSpecifier {
-  /* The macro below must be defined wherever this file is included. */
-  INSTRUCTION_SPECIFIER_FIELDS
-};
+static const unsigned X86_MAX_OPERANDS = 5;
 
-/*
- * Decoding mode for the Intel disassembler.  16-bit, 32-bit, and 64-bit mode
- * are supported, and represent real mode, IA-32e, and IA-32e in 64-bit mode,
- * respectively.
- */
-typedef enum {
+/// Decoding mode for the Intel disassembler.  16-bit, 32-bit, and 64-bit mode
+/// are supported, and represent real mode, IA-32e, and IA-32e in 64-bit mode,
+/// respectively.
+enum DisassemblerMode {
   MODE_16BIT,
   MODE_32BIT,
   MODE_64BIT
-} DisassemblerMode;
+};
+
+} // namespace X86Disassembler
+} // namespace llvm
 
 #endif