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1 //===-- X86Disassembler.cpp - Disassembler for x86 and x86_64 -------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is part of the X86 Disassembler.
11 // It contains code to translate the data produced by the decoder into
12 //  MCInsts.
13 //
14 //
15 // The X86 disassembler is a table-driven disassembler for the 16-, 32-, and
16 // 64-bit X86 instruction sets.  The main decode sequence for an assembly
17 // instruction in this disassembler is:
18 //
19 // 1. Read the prefix bytes and determine the attributes of the instruction.
20 //    These attributes, recorded in enum attributeBits
21 //    (X86DisassemblerDecoderCommon.h), form a bitmask.  The table CONTEXTS_SYM
22 //    provides a mapping from bitmasks to contexts, which are represented by
23 //    enum InstructionContext (ibid.).
24 //
25 // 2. Read the opcode, and determine what kind of opcode it is.  The
26 //    disassembler distinguishes four kinds of opcodes, which are enumerated in
27 //    OpcodeType (X86DisassemblerDecoderCommon.h): one-byte (0xnn), two-byte
28 //    (0x0f 0xnn), three-byte-38 (0x0f 0x38 0xnn), or three-byte-3a
29 //    (0x0f 0x3a 0xnn).  Mandatory prefixes are treated as part of the context.
30 //
31 // 3. Depending on the opcode type, look in one of four ClassDecision structures
32 //    (X86DisassemblerDecoderCommon.h).  Use the opcode class to determine which
33 //    OpcodeDecision (ibid.) to look the opcode in.  Look up the opcode, to get
34 //    a ModRMDecision (ibid.).
35 //
36 // 4. Some instructions, such as escape opcodes or extended opcodes, or even
37 //    instructions that have ModRM*Reg / ModRM*Mem forms in LLVM, need the
38 //    ModR/M byte to complete decode.  The ModRMDecision's type is an entry from
39 //    ModRMDecisionType (X86DisassemblerDecoderCommon.h) that indicates if the
40 //    ModR/M byte is required and how to interpret it.
41 //
42 // 5. After resolving the ModRMDecision, the disassembler has a unique ID
43 //    of type InstrUID (X86DisassemblerDecoderCommon.h).  Looking this ID up in
44 //    INSTRUCTIONS_SYM yields the name of the instruction and the encodings and
45 //    meanings of its operands.
46 //
47 // 6. For each operand, its encoding is an entry from OperandEncoding
48 //    (X86DisassemblerDecoderCommon.h) and its type is an entry from
49 //    OperandType (ibid.).  The encoding indicates how to read it from the
50 //    instruction; the type indicates how to interpret the value once it has
51 //    been read.  For example, a register operand could be stored in the R/M
52 //    field of the ModR/M byte, the REG field of the ModR/M byte, or added to
53 //    the main opcode.  This is orthogonal from its meaning (an GPR or an XMM
54 //    register, for instance).  Given this information, the operands can be
55 //    extracted and interpreted.
56 //
57 // 7. As the last step, the disassembler translates the instruction information
58 //    and operands into a format understandable by the client - in this case, an
59 //    MCInst for use by the MC infrastructure.
60 //
61 // The disassembler is broken broadly into two parts: the table emitter that
62 // emits the instruction decode tables discussed above during compilation, and
63 // the disassembler itself.  The table emitter is documented in more detail in
64 // utils/TableGen/X86DisassemblerEmitter.h.
65 //
66 // X86Disassembler.cpp contains the code responsible for step 7, and for
67 //   invoking the decoder to execute steps 1-6.
68 // X86DisassemblerDecoderCommon.h contains the definitions needed by both the
69 //   table emitter and the disassembler.
70 // X86DisassemblerDecoder.h contains the public interface of the decoder,
71 //   factored out into C for possible use by other projects.
72 // X86DisassemblerDecoder.c contains the source code of the decoder, which is
73 //   responsible for steps 1-6.
74 //
75 //===----------------------------------------------------------------------===//
76 
77 #include "X86DisassemblerDecoder.h"
78 #include "MCTargetDesc/X86MCTargetDesc.h"
79 #include "llvm/MC/MCContext.h"
80 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
81 #include "llvm/MC/MCExpr.h"
82 #include "llvm/MC/MCInst.h"
83 #include "llvm/MC/MCInstrInfo.h"
84 #include "llvm/MC/MCSubtargetInfo.h"
85 #include "llvm/Support/Debug.h"
86 #include "llvm/Support/TargetRegistry.h"
87 #include "llvm/Support/raw_ostream.h"
88 
89 using namespace llvm;
90 using namespace llvm::X86Disassembler;
91 
92 #define DEBUG_TYPE "x86-disassembler"
93 
Debug(const char * file,unsigned line,const char * s)94 void llvm::X86Disassembler::Debug(const char *file, unsigned line,
95                                   const char *s) {
96   dbgs() << file << ":" << line << ": " << s;
97 }
98 
GetInstrName(unsigned Opcode,const void * mii)99 const char *llvm::X86Disassembler::GetInstrName(unsigned Opcode,
100                                                 const void *mii) {
101   const MCInstrInfo *MII = static_cast<const MCInstrInfo *>(mii);
102   return MII->getName(Opcode);
103 }
104 
105 #define debug(s) DEBUG(Debug(__FILE__, __LINE__, s));
106 
107 namespace llvm {
108 
109 // Fill-ins to make the compiler happy.  These constants are never actually
110 //   assigned; they are just filler to make an automatically-generated switch
111 //   statement work.
112 namespace X86 {
113   enum {
114     BX_SI = 500,
115     BX_DI = 501,
116     BP_SI = 502,
117     BP_DI = 503,
118     sib   = 504,
119     sib64 = 505
120   };
121 }
122 
123 }
124 
125 static bool translateInstruction(MCInst &target,
126                                 InternalInstruction &source,
127                                 const MCDisassembler *Dis);
128 
129 namespace {
130 
131 /// Generic disassembler for all X86 platforms. All each platform class should
132 /// have to do is subclass the constructor, and provide a different
133 /// disassemblerMode value.
134 class X86GenericDisassembler : public MCDisassembler {
135   std::unique_ptr<const MCInstrInfo> MII;
136 public:
137   X86GenericDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx,
138                          std::unique_ptr<const MCInstrInfo> MII);
139 public:
140   DecodeStatus getInstruction(MCInst &instr, uint64_t &size,
141                               ArrayRef<uint8_t> Bytes, uint64_t Address,
142                               raw_ostream &vStream,
143                               raw_ostream &cStream) const override;
144 
145 private:
146   DisassemblerMode              fMode;
147 };
148 
149 }
150 
X86GenericDisassembler(const MCSubtargetInfo & STI,MCContext & Ctx,std::unique_ptr<const MCInstrInfo> MII)151 X86GenericDisassembler::X86GenericDisassembler(
152                                          const MCSubtargetInfo &STI,
153                                          MCContext &Ctx,
154                                          std::unique_ptr<const MCInstrInfo> MII)
155   : MCDisassembler(STI, Ctx), MII(std::move(MII)) {
156   const FeatureBitset &FB = STI.getFeatureBits();
157   if (FB[X86::Mode16Bit]) {
158     fMode = MODE_16BIT;
159     return;
160   } else if (FB[X86::Mode32Bit]) {
161     fMode = MODE_32BIT;
162     return;
163   } else if (FB[X86::Mode64Bit]) {
164     fMode = MODE_64BIT;
165     return;
166   }
167 
168   llvm_unreachable("Invalid CPU mode");
169 }
170 
171 namespace {
172 struct Region {
173   ArrayRef<uint8_t> Bytes;
174   uint64_t Base;
Region__anon3bbb8e950311::Region175   Region(ArrayRef<uint8_t> Bytes, uint64_t Base) : Bytes(Bytes), Base(Base) {}
176 };
177 } // end anonymous namespace
178 
179 /// A callback function that wraps the readByte method from Region.
180 ///
181 /// @param Arg      - The generic callback parameter.  In this case, this should
182 ///                   be a pointer to a Region.
183 /// @param Byte     - A pointer to the byte to be read.
184 /// @param Address  - The address to be read.
regionReader(const void * Arg,uint8_t * Byte,uint64_t Address)185 static int regionReader(const void *Arg, uint8_t *Byte, uint64_t Address) {
186   auto *R = static_cast<const Region *>(Arg);
187   ArrayRef<uint8_t> Bytes = R->Bytes;
188   unsigned Index = Address - R->Base;
189   if (Bytes.size() <= Index)
190     return -1;
191   *Byte = Bytes[Index];
192   return 0;
193 }
194 
195 /// logger - a callback function that wraps the operator<< method from
196 ///   raw_ostream.
197 ///
198 /// @param arg      - The generic callback parameter.  This should be a pointe
199 ///                   to a raw_ostream.
200 /// @param log      - A string to be logged.  logger() adds a newline.
logger(void * arg,const char * log)201 static void logger(void* arg, const char* log) {
202   if (!arg)
203     return;
204 
205   raw_ostream &vStream = *(static_cast<raw_ostream*>(arg));
206   vStream << log << "\n";
207 }
208 
209 //
210 // Public interface for the disassembler
211 //
212 
getInstruction(MCInst & Instr,uint64_t & Size,ArrayRef<uint8_t> Bytes,uint64_t Address,raw_ostream & VStream,raw_ostream & CStream) const213 MCDisassembler::DecodeStatus X86GenericDisassembler::getInstruction(
214     MCInst &Instr, uint64_t &Size, ArrayRef<uint8_t> Bytes, uint64_t Address,
215     raw_ostream &VStream, raw_ostream &CStream) const {
216   CommentStream = &CStream;
217 
218   InternalInstruction InternalInstr;
219 
220   dlog_t LoggerFn = logger;
221   if (&VStream == &nulls())
222     LoggerFn = nullptr; // Disable logging completely if it's going to nulls().
223 
224   Region R(Bytes, Address);
225 
226   int Ret = decodeInstruction(&InternalInstr, regionReader, (const void *)&R,
227                               LoggerFn, (void *)&VStream,
228                               (const void *)MII.get(), Address, fMode);
229 
230   if (Ret) {
231     Size = InternalInstr.readerCursor - Address;
232     return Fail;
233   } else {
234     Size = InternalInstr.length;
235     return (!translateInstruction(Instr, InternalInstr, this)) ? Success : Fail;
236   }
237 }
238 
239 //
240 // Private code that translates from struct InternalInstructions to MCInsts.
241 //
242 
243 /// translateRegister - Translates an internal register to the appropriate LLVM
244 ///   register, and appends it as an operand to an MCInst.
245 ///
246 /// @param mcInst     - The MCInst to append to.
247 /// @param reg        - The Reg to append.
translateRegister(MCInst & mcInst,Reg reg)248 static void translateRegister(MCInst &mcInst, Reg reg) {
249 #define ENTRY(x) X86::x,
250   uint8_t llvmRegnums[] = {
251     ALL_REGS
252     0
253   };
254 #undef ENTRY
255 
256   uint8_t llvmRegnum = llvmRegnums[reg];
257   mcInst.addOperand(MCOperand::createReg(llvmRegnum));
258 }
259 
260 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
261 /// immediate Value in the MCInst.
262 ///
263 /// @param Value      - The immediate Value, has had any PC adjustment made by
264 ///                     the caller.
265 /// @param isBranch   - If the instruction is a branch instruction
266 /// @param Address    - The starting address of the instruction
267 /// @param Offset     - The byte offset to this immediate in the instruction
268 /// @param Width      - The byte width of this immediate in the instruction
269 ///
270 /// If the getOpInfo() function was set when setupForSymbolicDisassembly() was
271 /// called then that function is called to get any symbolic information for the
272 /// immediate in the instruction using the Address, Offset and Width.  If that
273 /// returns non-zero then the symbolic information it returns is used to create
274 /// an MCExpr and that is added as an operand to the MCInst.  If getOpInfo()
275 /// returns zero and isBranch is true then a symbol look up for immediate Value
276 /// is done and if a symbol is found an MCExpr is created with that, else
277 /// an MCExpr with the immediate Value is created.  This function returns true
278 /// if it adds an operand to the MCInst and false otherwise.
tryAddingSymbolicOperand(int64_t Value,bool isBranch,uint64_t Address,uint64_t Offset,uint64_t Width,MCInst & MI,const MCDisassembler * Dis)279 static bool tryAddingSymbolicOperand(int64_t Value, bool isBranch,
280                                      uint64_t Address, uint64_t Offset,
281                                      uint64_t Width, MCInst &MI,
282                                      const MCDisassembler *Dis) {
283   return Dis->tryAddingSymbolicOperand(MI, Value, Address, isBranch,
284                                        Offset, Width);
285 }
286 
287 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
288 /// referenced by a load instruction with the base register that is the rip.
289 /// These can often be addresses in a literal pool.  The Address of the
290 /// instruction and its immediate Value are used to determine the address
291 /// being referenced in the literal pool entry.  The SymbolLookUp call back will
292 /// return a pointer to a literal 'C' string if the referenced address is an
293 /// address into a section with 'C' string literals.
tryAddingPcLoadReferenceComment(uint64_t Address,uint64_t Value,const void * Decoder)294 static void tryAddingPcLoadReferenceComment(uint64_t Address, uint64_t Value,
295                                             const void *Decoder) {
296   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
297   Dis->tryAddingPcLoadReferenceComment(Value, Address);
298 }
299 
300 static const uint8_t segmentRegnums[SEG_OVERRIDE_max] = {
301   0,        // SEG_OVERRIDE_NONE
302   X86::CS,
303   X86::SS,
304   X86::DS,
305   X86::ES,
306   X86::FS,
307   X86::GS
308 };
309 
310 /// translateSrcIndex   - Appends a source index operand to an MCInst.
311 ///
312 /// @param mcInst       - The MCInst to append to.
313 /// @param insn         - The internal instruction.
translateSrcIndex(MCInst & mcInst,InternalInstruction & insn)314 static bool translateSrcIndex(MCInst &mcInst, InternalInstruction &insn) {
315   unsigned baseRegNo;
316 
317   if (insn.mode == MODE_64BIT)
318     baseRegNo = insn.prefixPresent[0x67] ? X86::ESI : X86::RSI;
319   else if (insn.mode == MODE_32BIT)
320     baseRegNo = insn.prefixPresent[0x67] ? X86::SI : X86::ESI;
321   else {
322     assert(insn.mode == MODE_16BIT);
323     baseRegNo = insn.prefixPresent[0x67] ? X86::ESI : X86::SI;
324   }
325   MCOperand baseReg = MCOperand::createReg(baseRegNo);
326   mcInst.addOperand(baseReg);
327 
328   MCOperand segmentReg;
329   segmentReg = MCOperand::createReg(segmentRegnums[insn.segmentOverride]);
330   mcInst.addOperand(segmentReg);
331   return false;
332 }
333 
334 /// translateDstIndex   - Appends a destination index operand to an MCInst.
335 ///
336 /// @param mcInst       - The MCInst to append to.
337 /// @param insn         - The internal instruction.
338 
translateDstIndex(MCInst & mcInst,InternalInstruction & insn)339 static bool translateDstIndex(MCInst &mcInst, InternalInstruction &insn) {
340   unsigned baseRegNo;
341 
342   if (insn.mode == MODE_64BIT)
343     baseRegNo = insn.prefixPresent[0x67] ? X86::EDI : X86::RDI;
344   else if (insn.mode == MODE_32BIT)
345     baseRegNo = insn.prefixPresent[0x67] ? X86::DI : X86::EDI;
346   else {
347     assert(insn.mode == MODE_16BIT);
348     baseRegNo = insn.prefixPresent[0x67] ? X86::EDI : X86::DI;
349   }
350   MCOperand baseReg = MCOperand::createReg(baseRegNo);
351   mcInst.addOperand(baseReg);
352   return false;
353 }
354 
355 /// translateImmediate  - Appends an immediate operand to an MCInst.
356 ///
357 /// @param mcInst       - The MCInst to append to.
358 /// @param immediate    - The immediate value to append.
359 /// @param operand      - The operand, as stored in the descriptor table.
360 /// @param insn         - The internal instruction.
translateImmediate(MCInst & mcInst,uint64_t immediate,const OperandSpecifier & operand,InternalInstruction & insn,const MCDisassembler * Dis)361 static void translateImmediate(MCInst &mcInst, uint64_t immediate,
362                                const OperandSpecifier &operand,
363                                InternalInstruction &insn,
364                                const MCDisassembler *Dis) {
365   // Sign-extend the immediate if necessary.
366 
367   OperandType type = (OperandType)operand.type;
368 
369   bool isBranch = false;
370   uint64_t pcrel = 0;
371   if (type == TYPE_RELv) {
372     isBranch = true;
373     pcrel = insn.startLocation +
374             insn.immediateOffset + insn.immediateSize;
375     switch (insn.displacementSize) {
376     default:
377       break;
378     case 1:
379       if(immediate & 0x80)
380         immediate |= ~(0xffull);
381       break;
382     case 2:
383       if(immediate & 0x8000)
384         immediate |= ~(0xffffull);
385       break;
386     case 4:
387       if(immediate & 0x80000000)
388         immediate |= ~(0xffffffffull);
389       break;
390     case 8:
391       break;
392     }
393   }
394   // By default sign-extend all X86 immediates based on their encoding.
395   else if (type == TYPE_IMM8 || type == TYPE_IMM16 || type == TYPE_IMM32 ||
396            type == TYPE_IMM64 || type == TYPE_IMMv) {
397     switch (operand.encoding) {
398     default:
399       break;
400     case ENCODING_IB:
401       if(immediate & 0x80)
402         immediate |= ~(0xffull);
403       break;
404     case ENCODING_IW:
405       if(immediate & 0x8000)
406         immediate |= ~(0xffffull);
407       break;
408     case ENCODING_ID:
409       if(immediate & 0x80000000)
410         immediate |= ~(0xffffffffull);
411       break;
412     case ENCODING_IO:
413       break;
414     }
415   } else if (type == TYPE_IMM3) {
416     // Check for immediates that printSSECC can't handle.
417     if (immediate >= 8) {
418       unsigned NewOpc;
419       switch (mcInst.getOpcode()) {
420       default: llvm_unreachable("unexpected opcode");
421       case X86::CMPPDrmi:  NewOpc = X86::CMPPDrmi_alt;  break;
422       case X86::CMPPDrri:  NewOpc = X86::CMPPDrri_alt;  break;
423       case X86::CMPPSrmi:  NewOpc = X86::CMPPSrmi_alt;  break;
424       case X86::CMPPSrri:  NewOpc = X86::CMPPSrri_alt;  break;
425       case X86::CMPSDrm:   NewOpc = X86::CMPSDrm_alt;   break;
426       case X86::CMPSDrr:   NewOpc = X86::CMPSDrr_alt;   break;
427       case X86::CMPSSrm:   NewOpc = X86::CMPSSrm_alt;   break;
428       case X86::CMPSSrr:   NewOpc = X86::CMPSSrr_alt;   break;
429       case X86::VPCOMBri:  NewOpc = X86::VPCOMBri_alt;  break;
430       case X86::VPCOMBmi:  NewOpc = X86::VPCOMBmi_alt;  break;
431       case X86::VPCOMWri:  NewOpc = X86::VPCOMWri_alt;  break;
432       case X86::VPCOMWmi:  NewOpc = X86::VPCOMWmi_alt;  break;
433       case X86::VPCOMDri:  NewOpc = X86::VPCOMDri_alt;  break;
434       case X86::VPCOMDmi:  NewOpc = X86::VPCOMDmi_alt;  break;
435       case X86::VPCOMQri:  NewOpc = X86::VPCOMQri_alt;  break;
436       case X86::VPCOMQmi:  NewOpc = X86::VPCOMQmi_alt;  break;
437       case X86::VPCOMUBri: NewOpc = X86::VPCOMUBri_alt; break;
438       case X86::VPCOMUBmi: NewOpc = X86::VPCOMUBmi_alt; break;
439       case X86::VPCOMUWri: NewOpc = X86::VPCOMUWri_alt; break;
440       case X86::VPCOMUWmi: NewOpc = X86::VPCOMUWmi_alt; break;
441       case X86::VPCOMUDri: NewOpc = X86::VPCOMUDri_alt; break;
442       case X86::VPCOMUDmi: NewOpc = X86::VPCOMUDmi_alt; break;
443       case X86::VPCOMUQri: NewOpc = X86::VPCOMUQri_alt; break;
444       case X86::VPCOMUQmi: NewOpc = X86::VPCOMUQmi_alt; break;
445       }
446       // Switch opcode to the one that doesn't get special printing.
447       mcInst.setOpcode(NewOpc);
448     }
449   } else if (type == TYPE_IMM5) {
450     // Check for immediates that printAVXCC can't handle.
451     if (immediate >= 32) {
452       unsigned NewOpc;
453       switch (mcInst.getOpcode()) {
454       default: llvm_unreachable("unexpected opcode");
455       case X86::VCMPPDrmi:   NewOpc = X86::VCMPPDrmi_alt;   break;
456       case X86::VCMPPDrri:   NewOpc = X86::VCMPPDrri_alt;   break;
457       case X86::VCMPPSrmi:   NewOpc = X86::VCMPPSrmi_alt;   break;
458       case X86::VCMPPSrri:   NewOpc = X86::VCMPPSrri_alt;   break;
459       case X86::VCMPSDrm:    NewOpc = X86::VCMPSDrm_alt;    break;
460       case X86::VCMPSDrr:    NewOpc = X86::VCMPSDrr_alt;    break;
461       case X86::VCMPSSrm:    NewOpc = X86::VCMPSSrm_alt;    break;
462       case X86::VCMPSSrr:    NewOpc = X86::VCMPSSrr_alt;    break;
463       case X86::VCMPPDYrmi:  NewOpc = X86::VCMPPDYrmi_alt;  break;
464       case X86::VCMPPDYrri:  NewOpc = X86::VCMPPDYrri_alt;  break;
465       case X86::VCMPPSYrmi:  NewOpc = X86::VCMPPSYrmi_alt;  break;
466       case X86::VCMPPSYrri:  NewOpc = X86::VCMPPSYrri_alt;  break;
467       case X86::VCMPPDZrmi:  NewOpc = X86::VCMPPDZrmi_alt;  break;
468       case X86::VCMPPDZrri:  NewOpc = X86::VCMPPDZrri_alt;  break;
469       case X86::VCMPPDZrrib: NewOpc = X86::VCMPPDZrrib_alt; break;
470       case X86::VCMPPSZrmi:  NewOpc = X86::VCMPPSZrmi_alt;  break;
471       case X86::VCMPPSZrri:  NewOpc = X86::VCMPPSZrri_alt;  break;
472       case X86::VCMPPSZrrib: NewOpc = X86::VCMPPSZrrib_alt; break;
473       case X86::VCMPSDZrm:   NewOpc = X86::VCMPSDZrmi_alt;  break;
474       case X86::VCMPSDZrr:   NewOpc = X86::VCMPSDZrri_alt;  break;
475       case X86::VCMPSSZrm:   NewOpc = X86::VCMPSSZrmi_alt;  break;
476       case X86::VCMPSSZrr:   NewOpc = X86::VCMPSSZrri_alt;  break;
477       }
478       // Switch opcode to the one that doesn't get special printing.
479       mcInst.setOpcode(NewOpc);
480     }
481   } else if (type == TYPE_AVX512ICC) {
482     if (immediate >= 8 || ((immediate & 0x3) == 3)) {
483       unsigned NewOpc;
484       switch (mcInst.getOpcode()) {
485       default: llvm_unreachable("unexpected opcode");
486       case X86::VPCMPBZ128rmi:    NewOpc = X86::VPCMPBZ128rmi_alt;    break;
487       case X86::VPCMPBZ128rmik:   NewOpc = X86::VPCMPBZ128rmik_alt;   break;
488       case X86::VPCMPBZ128rri:    NewOpc = X86::VPCMPBZ128rri_alt;    break;
489       case X86::VPCMPBZ128rrik:   NewOpc = X86::VPCMPBZ128rrik_alt;   break;
490       case X86::VPCMPBZ256rmi:    NewOpc = X86::VPCMPBZ256rmi_alt;    break;
491       case X86::VPCMPBZ256rmik:   NewOpc = X86::VPCMPBZ256rmik_alt;   break;
492       case X86::VPCMPBZ256rri:    NewOpc = X86::VPCMPBZ256rri_alt;    break;
493       case X86::VPCMPBZ256rrik:   NewOpc = X86::VPCMPBZ256rrik_alt;   break;
494       case X86::VPCMPBZrmi:       NewOpc = X86::VPCMPBZrmi_alt;       break;
495       case X86::VPCMPBZrmik:      NewOpc = X86::VPCMPBZrmik_alt;      break;
496       case X86::VPCMPBZrri:       NewOpc = X86::VPCMPBZrri_alt;       break;
497       case X86::VPCMPBZrrik:      NewOpc = X86::VPCMPBZrrik_alt;      break;
498       case X86::VPCMPDZ128rmi:    NewOpc = X86::VPCMPDZ128rmi_alt;    break;
499       case X86::VPCMPDZ128rmib:   NewOpc = X86::VPCMPDZ128rmib_alt;   break;
500       case X86::VPCMPDZ128rmibk:  NewOpc = X86::VPCMPDZ128rmibk_alt;  break;
501       case X86::VPCMPDZ128rmik:   NewOpc = X86::VPCMPDZ128rmik_alt;   break;
502       case X86::VPCMPDZ128rri:    NewOpc = X86::VPCMPDZ128rri_alt;    break;
503       case X86::VPCMPDZ128rrik:   NewOpc = X86::VPCMPDZ128rrik_alt;   break;
504       case X86::VPCMPDZ256rmi:    NewOpc = X86::VPCMPDZ256rmi_alt;    break;
505       case X86::VPCMPDZ256rmib:   NewOpc = X86::VPCMPDZ256rmib_alt;   break;
506       case X86::VPCMPDZ256rmibk:  NewOpc = X86::VPCMPDZ256rmibk_alt;  break;
507       case X86::VPCMPDZ256rmik:   NewOpc = X86::VPCMPDZ256rmik_alt;   break;
508       case X86::VPCMPDZ256rri:    NewOpc = X86::VPCMPDZ256rri_alt;    break;
509       case X86::VPCMPDZ256rrik:   NewOpc = X86::VPCMPDZ256rrik_alt;   break;
510       case X86::VPCMPDZrmi:       NewOpc = X86::VPCMPDZrmi_alt;       break;
511       case X86::VPCMPDZrmib:      NewOpc = X86::VPCMPDZrmib_alt;      break;
512       case X86::VPCMPDZrmibk:     NewOpc = X86::VPCMPDZrmibk_alt;     break;
513       case X86::VPCMPDZrmik:      NewOpc = X86::VPCMPDZrmik_alt;      break;
514       case X86::VPCMPDZrri:       NewOpc = X86::VPCMPDZrri_alt;       break;
515       case X86::VPCMPDZrrik:      NewOpc = X86::VPCMPDZrrik_alt;      break;
516       case X86::VPCMPQZ128rmi:    NewOpc = X86::VPCMPQZ128rmi_alt;    break;
517       case X86::VPCMPQZ128rmib:   NewOpc = X86::VPCMPQZ128rmib_alt;   break;
518       case X86::VPCMPQZ128rmibk:  NewOpc = X86::VPCMPQZ128rmibk_alt;  break;
519       case X86::VPCMPQZ128rmik:   NewOpc = X86::VPCMPQZ128rmik_alt;   break;
520       case X86::VPCMPQZ128rri:    NewOpc = X86::VPCMPQZ128rri_alt;    break;
521       case X86::VPCMPQZ128rrik:   NewOpc = X86::VPCMPQZ128rrik_alt;   break;
522       case X86::VPCMPQZ256rmi:    NewOpc = X86::VPCMPQZ256rmi_alt;    break;
523       case X86::VPCMPQZ256rmib:   NewOpc = X86::VPCMPQZ256rmib_alt;   break;
524       case X86::VPCMPQZ256rmibk:  NewOpc = X86::VPCMPQZ256rmibk_alt;  break;
525       case X86::VPCMPQZ256rmik:   NewOpc = X86::VPCMPQZ256rmik_alt;   break;
526       case X86::VPCMPQZ256rri:    NewOpc = X86::VPCMPQZ256rri_alt;    break;
527       case X86::VPCMPQZ256rrik:   NewOpc = X86::VPCMPQZ256rrik_alt;   break;
528       case X86::VPCMPQZrmi:       NewOpc = X86::VPCMPQZrmi_alt;       break;
529       case X86::VPCMPQZrmib:      NewOpc = X86::VPCMPQZrmib_alt;      break;
530       case X86::VPCMPQZrmibk:     NewOpc = X86::VPCMPQZrmibk_alt;     break;
531       case X86::VPCMPQZrmik:      NewOpc = X86::VPCMPQZrmik_alt;      break;
532       case X86::VPCMPQZrri:       NewOpc = X86::VPCMPQZrri_alt;       break;
533       case X86::VPCMPQZrrik:      NewOpc = X86::VPCMPQZrrik_alt;      break;
534       case X86::VPCMPUBZ128rmi:   NewOpc = X86::VPCMPUBZ128rmi_alt;   break;
535       case X86::VPCMPUBZ128rmik:  NewOpc = X86::VPCMPUBZ128rmik_alt;  break;
536       case X86::VPCMPUBZ128rri:   NewOpc = X86::VPCMPUBZ128rri_alt;   break;
537       case X86::VPCMPUBZ128rrik:  NewOpc = X86::VPCMPUBZ128rrik_alt;  break;
538       case X86::VPCMPUBZ256rmi:   NewOpc = X86::VPCMPUBZ256rmi_alt;   break;
539       case X86::VPCMPUBZ256rmik:  NewOpc = X86::VPCMPUBZ256rmik_alt;  break;
540       case X86::VPCMPUBZ256rri:   NewOpc = X86::VPCMPUBZ256rri_alt;   break;
541       case X86::VPCMPUBZ256rrik:  NewOpc = X86::VPCMPUBZ256rrik_alt;  break;
542       case X86::VPCMPUBZrmi:      NewOpc = X86::VPCMPUBZrmi_alt;      break;
543       case X86::VPCMPUBZrmik:     NewOpc = X86::VPCMPUBZrmik_alt;     break;
544       case X86::VPCMPUBZrri:      NewOpc = X86::VPCMPUBZrri_alt;      break;
545       case X86::VPCMPUBZrrik:     NewOpc = X86::VPCMPUBZrrik_alt;     break;
546       case X86::VPCMPUDZ128rmi:   NewOpc = X86::VPCMPUDZ128rmi_alt;   break;
547       case X86::VPCMPUDZ128rmib:  NewOpc = X86::VPCMPUDZ128rmib_alt;  break;
548       case X86::VPCMPUDZ128rmibk: NewOpc = X86::VPCMPUDZ128rmibk_alt; break;
549       case X86::VPCMPUDZ128rmik:  NewOpc = X86::VPCMPUDZ128rmik_alt;  break;
550       case X86::VPCMPUDZ128rri:   NewOpc = X86::VPCMPUDZ128rri_alt;   break;
551       case X86::VPCMPUDZ128rrik:  NewOpc = X86::VPCMPUDZ128rrik_alt;  break;
552       case X86::VPCMPUDZ256rmi:   NewOpc = X86::VPCMPUDZ256rmi_alt;   break;
553       case X86::VPCMPUDZ256rmib:  NewOpc = X86::VPCMPUDZ256rmib_alt;  break;
554       case X86::VPCMPUDZ256rmibk: NewOpc = X86::VPCMPUDZ256rmibk_alt; break;
555       case X86::VPCMPUDZ256rmik:  NewOpc = X86::VPCMPUDZ256rmik_alt;  break;
556       case X86::VPCMPUDZ256rri:   NewOpc = X86::VPCMPUDZ256rri_alt;   break;
557       case X86::VPCMPUDZ256rrik:  NewOpc = X86::VPCMPUDZ256rrik_alt;  break;
558       case X86::VPCMPUDZrmi:      NewOpc = X86::VPCMPUDZrmi_alt;      break;
559       case X86::VPCMPUDZrmib:     NewOpc = X86::VPCMPUDZrmib_alt;     break;
560       case X86::VPCMPUDZrmibk:    NewOpc = X86::VPCMPUDZrmibk_alt;    break;
561       case X86::VPCMPUDZrmik:     NewOpc = X86::VPCMPUDZrmik_alt;     break;
562       case X86::VPCMPUDZrri:      NewOpc = X86::VPCMPUDZrri_alt;      break;
563       case X86::VPCMPUDZrrik:     NewOpc = X86::VPCMPUDZrrik_alt;     break;
564       case X86::VPCMPUQZ128rmi:   NewOpc = X86::VPCMPUQZ128rmi_alt;   break;
565       case X86::VPCMPUQZ128rmib:  NewOpc = X86::VPCMPUQZ128rmib_alt;  break;
566       case X86::VPCMPUQZ128rmibk: NewOpc = X86::VPCMPUQZ128rmibk_alt; break;
567       case X86::VPCMPUQZ128rmik:  NewOpc = X86::VPCMPUQZ128rmik_alt;  break;
568       case X86::VPCMPUQZ128rri:   NewOpc = X86::VPCMPUQZ128rri_alt;   break;
569       case X86::VPCMPUQZ128rrik:  NewOpc = X86::VPCMPUQZ128rrik_alt;  break;
570       case X86::VPCMPUQZ256rmi:   NewOpc = X86::VPCMPUQZ256rmi_alt;   break;
571       case X86::VPCMPUQZ256rmib:  NewOpc = X86::VPCMPUQZ256rmib_alt;  break;
572       case X86::VPCMPUQZ256rmibk: NewOpc = X86::VPCMPUQZ256rmibk_alt; break;
573       case X86::VPCMPUQZ256rmik:  NewOpc = X86::VPCMPUQZ256rmik_alt;  break;
574       case X86::VPCMPUQZ256rri:   NewOpc = X86::VPCMPUQZ256rri_alt;   break;
575       case X86::VPCMPUQZ256rrik:  NewOpc = X86::VPCMPUQZ256rrik_alt;  break;
576       case X86::VPCMPUQZrmi:      NewOpc = X86::VPCMPUQZrmi_alt;      break;
577       case X86::VPCMPUQZrmib:     NewOpc = X86::VPCMPUQZrmib_alt;     break;
578       case X86::VPCMPUQZrmibk:    NewOpc = X86::VPCMPUQZrmibk_alt;    break;
579       case X86::VPCMPUQZrmik:     NewOpc = X86::VPCMPUQZrmik_alt;     break;
580       case X86::VPCMPUQZrri:      NewOpc = X86::VPCMPUQZrri_alt;      break;
581       case X86::VPCMPUQZrrik:     NewOpc = X86::VPCMPUQZrrik_alt;     break;
582       case X86::VPCMPUWZ128rmi:   NewOpc = X86::VPCMPUWZ128rmi_alt;   break;
583       case X86::VPCMPUWZ128rmik:  NewOpc = X86::VPCMPUWZ128rmik_alt;  break;
584       case X86::VPCMPUWZ128rri:   NewOpc = X86::VPCMPUWZ128rri_alt;   break;
585       case X86::VPCMPUWZ128rrik:  NewOpc = X86::VPCMPUWZ128rrik_alt;  break;
586       case X86::VPCMPUWZ256rmi:   NewOpc = X86::VPCMPUWZ256rmi_alt;   break;
587       case X86::VPCMPUWZ256rmik:  NewOpc = X86::VPCMPUWZ256rmik_alt;  break;
588       case X86::VPCMPUWZ256rri:   NewOpc = X86::VPCMPUWZ256rri_alt;   break;
589       case X86::VPCMPUWZ256rrik:  NewOpc = X86::VPCMPUWZ256rrik_alt;  break;
590       case X86::VPCMPUWZrmi:      NewOpc = X86::VPCMPUWZrmi_alt;      break;
591       case X86::VPCMPUWZrmik:     NewOpc = X86::VPCMPUWZrmik_alt;     break;
592       case X86::VPCMPUWZrri:      NewOpc = X86::VPCMPUWZrri_alt;      break;
593       case X86::VPCMPUWZrrik:     NewOpc = X86::VPCMPUWZrrik_alt;     break;
594       case X86::VPCMPWZ128rmi:    NewOpc = X86::VPCMPWZ128rmi_alt;    break;
595       case X86::VPCMPWZ128rmik:   NewOpc = X86::VPCMPWZ128rmik_alt;   break;
596       case X86::VPCMPWZ128rri:    NewOpc = X86::VPCMPWZ128rri_alt;    break;
597       case X86::VPCMPWZ128rrik:   NewOpc = X86::VPCMPWZ128rrik_alt;   break;
598       case X86::VPCMPWZ256rmi:    NewOpc = X86::VPCMPWZ256rmi_alt;    break;
599       case X86::VPCMPWZ256rmik:   NewOpc = X86::VPCMPWZ256rmik_alt;   break;
600       case X86::VPCMPWZ256rri:    NewOpc = X86::VPCMPWZ256rri_alt;    break;
601       case X86::VPCMPWZ256rrik:   NewOpc = X86::VPCMPWZ256rrik_alt;   break;
602       case X86::VPCMPWZrmi:       NewOpc = X86::VPCMPWZrmi_alt;       break;
603       case X86::VPCMPWZrmik:      NewOpc = X86::VPCMPWZrmik_alt;      break;
604       case X86::VPCMPWZrri:       NewOpc = X86::VPCMPWZrri_alt;       break;
605       case X86::VPCMPWZrrik:      NewOpc = X86::VPCMPWZrrik_alt;      break;
606       }
607       // Switch opcode to the one that doesn't get special printing.
608       mcInst.setOpcode(NewOpc);
609     }
610   }
611 
612   switch (type) {
613   case TYPE_XMM32:
614   case TYPE_XMM64:
615   case TYPE_XMM128:
616     mcInst.addOperand(MCOperand::createReg(X86::XMM0 + (immediate >> 4)));
617     return;
618   case TYPE_XMM256:
619     mcInst.addOperand(MCOperand::createReg(X86::YMM0 + (immediate >> 4)));
620     return;
621   case TYPE_XMM512:
622     mcInst.addOperand(MCOperand::createReg(X86::ZMM0 + (immediate >> 4)));
623     return;
624   case TYPE_BNDR:
625     mcInst.addOperand(MCOperand::createReg(X86::BND0 + (immediate >> 4)));
626   case TYPE_REL8:
627     isBranch = true;
628     pcrel = insn.startLocation + insn.immediateOffset + insn.immediateSize;
629     if (immediate & 0x80)
630       immediate |= ~(0xffull);
631     break;
632   case TYPE_REL16:
633     isBranch = true;
634     pcrel = insn.startLocation + insn.immediateOffset + insn.immediateSize;
635     if (immediate & 0x8000)
636       immediate |= ~(0xffffull);
637     break;
638   case TYPE_REL32:
639   case TYPE_REL64:
640     isBranch = true;
641     pcrel = insn.startLocation + insn.immediateOffset + insn.immediateSize;
642     if(immediate & 0x80000000)
643       immediate |= ~(0xffffffffull);
644     break;
645   default:
646     // operand is 64 bits wide.  Do nothing.
647     break;
648   }
649 
650   if(!tryAddingSymbolicOperand(immediate + pcrel, isBranch, insn.startLocation,
651                                insn.immediateOffset, insn.immediateSize,
652                                mcInst, Dis))
653     mcInst.addOperand(MCOperand::createImm(immediate));
654 
655   if (type == TYPE_MOFFS8 || type == TYPE_MOFFS16 ||
656       type == TYPE_MOFFS32 || type == TYPE_MOFFS64) {
657     MCOperand segmentReg;
658     segmentReg = MCOperand::createReg(segmentRegnums[insn.segmentOverride]);
659     mcInst.addOperand(segmentReg);
660   }
661 }
662 
663 /// translateRMRegister - Translates a register stored in the R/M field of the
664 ///   ModR/M byte to its LLVM equivalent and appends it to an MCInst.
665 /// @param mcInst       - The MCInst to append to.
666 /// @param insn         - The internal instruction to extract the R/M field
667 ///                       from.
668 /// @return             - 0 on success; -1 otherwise
translateRMRegister(MCInst & mcInst,InternalInstruction & insn)669 static bool translateRMRegister(MCInst &mcInst,
670                                 InternalInstruction &insn) {
671   if (insn.eaBase == EA_BASE_sib || insn.eaBase == EA_BASE_sib64) {
672     debug("A R/M register operand may not have a SIB byte");
673     return true;
674   }
675 
676   switch (insn.eaBase) {
677   default:
678     debug("Unexpected EA base register");
679     return true;
680   case EA_BASE_NONE:
681     debug("EA_BASE_NONE for ModR/M base");
682     return true;
683 #define ENTRY(x) case EA_BASE_##x:
684   ALL_EA_BASES
685 #undef ENTRY
686     debug("A R/M register operand may not have a base; "
687           "the operand must be a register.");
688     return true;
689 #define ENTRY(x)                                                      \
690   case EA_REG_##x:                                                    \
691     mcInst.addOperand(MCOperand::createReg(X86::x)); break;
692   ALL_REGS
693 #undef ENTRY
694   }
695 
696   return false;
697 }
698 
699 /// translateRMMemory - Translates a memory operand stored in the Mod and R/M
700 ///   fields of an internal instruction (and possibly its SIB byte) to a memory
701 ///   operand in LLVM's format, and appends it to an MCInst.
702 ///
703 /// @param mcInst       - The MCInst to append to.
704 /// @param insn         - The instruction to extract Mod, R/M, and SIB fields
705 ///                       from.
706 /// @return             - 0 on success; nonzero otherwise
translateRMMemory(MCInst & mcInst,InternalInstruction & insn,const MCDisassembler * Dis)707 static bool translateRMMemory(MCInst &mcInst, InternalInstruction &insn,
708                               const MCDisassembler *Dis) {
709   // Addresses in an MCInst are represented as five operands:
710   //   1. basereg       (register)  The R/M base, or (if there is a SIB) the
711   //                                SIB base
712   //   2. scaleamount   (immediate) 1, or (if there is a SIB) the specified
713   //                                scale amount
714   //   3. indexreg      (register)  x86_registerNONE, or (if there is a SIB)
715   //                                the index (which is multiplied by the
716   //                                scale amount)
717   //   4. displacement  (immediate) 0, or the displacement if there is one
718   //   5. segmentreg    (register)  x86_registerNONE for now, but could be set
719   //                                if we have segment overrides
720 
721   MCOperand baseReg;
722   MCOperand scaleAmount;
723   MCOperand indexReg;
724   MCOperand displacement;
725   MCOperand segmentReg;
726   uint64_t pcrel = 0;
727 
728   if (insn.eaBase == EA_BASE_sib || insn.eaBase == EA_BASE_sib64) {
729     if (insn.sibBase != SIB_BASE_NONE) {
730       switch (insn.sibBase) {
731       default:
732         debug("Unexpected sibBase");
733         return true;
734 #define ENTRY(x)                                          \
735       case SIB_BASE_##x:                                  \
736         baseReg = MCOperand::createReg(X86::x); break;
737       ALL_SIB_BASES
738 #undef ENTRY
739       }
740     } else {
741       baseReg = MCOperand::createReg(0);
742     }
743 
744     // Check whether we are handling VSIB addressing mode for GATHER.
745     // If sibIndex was set to SIB_INDEX_NONE, index offset is 4 and
746     // we should use SIB_INDEX_XMM4|YMM4 for VSIB.
747     // I don't see a way to get the correct IndexReg in readSIB:
748     //   We can tell whether it is VSIB or SIB after instruction ID is decoded,
749     //   but instruction ID may not be decoded yet when calling readSIB.
750     uint32_t Opcode = mcInst.getOpcode();
751     bool IndexIs128 = (Opcode == X86::VGATHERDPDrm ||
752                        Opcode == X86::VGATHERDPDYrm ||
753                        Opcode == X86::VGATHERQPDrm ||
754                        Opcode == X86::VGATHERDPSrm ||
755                        Opcode == X86::VGATHERQPSrm ||
756                        Opcode == X86::VPGATHERDQrm ||
757                        Opcode == X86::VPGATHERDQYrm ||
758                        Opcode == X86::VPGATHERQQrm ||
759                        Opcode == X86::VPGATHERDDrm ||
760                        Opcode == X86::VPGATHERQDrm);
761     bool IndexIs256 = (Opcode == X86::VGATHERQPDYrm ||
762                        Opcode == X86::VGATHERDPSYrm ||
763                        Opcode == X86::VGATHERQPSYrm ||
764                        Opcode == X86::VGATHERDPDZrm ||
765                        Opcode == X86::VPGATHERDQZrm ||
766                        Opcode == X86::VPGATHERQQYrm ||
767                        Opcode == X86::VPGATHERDDYrm ||
768                        Opcode == X86::VPGATHERQDYrm);
769     bool IndexIs512 = (Opcode == X86::VGATHERQPDZrm ||
770                        Opcode == X86::VGATHERDPSZrm ||
771                        Opcode == X86::VGATHERQPSZrm ||
772                        Opcode == X86::VPGATHERQQZrm ||
773                        Opcode == X86::VPGATHERDDZrm ||
774                        Opcode == X86::VPGATHERQDZrm);
775     if (IndexIs128 || IndexIs256 || IndexIs512) {
776       unsigned IndexOffset = insn.sibIndex -
777                          (insn.addressSize == 8 ? SIB_INDEX_RAX:SIB_INDEX_EAX);
778       SIBIndex IndexBase = IndexIs512 ? SIB_INDEX_ZMM0 :
779                            IndexIs256 ? SIB_INDEX_YMM0 : SIB_INDEX_XMM0;
780       insn.sibIndex = (SIBIndex)(IndexBase +
781                            (insn.sibIndex == SIB_INDEX_NONE ? 4 : IndexOffset));
782     }
783 
784     if (insn.sibIndex != SIB_INDEX_NONE) {
785       switch (insn.sibIndex) {
786       default:
787         debug("Unexpected sibIndex");
788         return true;
789 #define ENTRY(x)                                          \
790       case SIB_INDEX_##x:                                 \
791         indexReg = MCOperand::createReg(X86::x); break;
792       EA_BASES_32BIT
793       EA_BASES_64BIT
794       REGS_XMM
795       REGS_YMM
796       REGS_ZMM
797 #undef ENTRY
798       }
799     } else {
800       indexReg = MCOperand::createReg(0);
801     }
802 
803     scaleAmount = MCOperand::createImm(insn.sibScale);
804   } else {
805     switch (insn.eaBase) {
806     case EA_BASE_NONE:
807       if (insn.eaDisplacement == EA_DISP_NONE) {
808         debug("EA_BASE_NONE and EA_DISP_NONE for ModR/M base");
809         return true;
810       }
811       if (insn.mode == MODE_64BIT){
812         pcrel = insn.startLocation +
813                 insn.displacementOffset + insn.displacementSize;
814         tryAddingPcLoadReferenceComment(insn.startLocation +
815                                         insn.displacementOffset,
816                                         insn.displacement + pcrel, Dis);
817         baseReg = MCOperand::createReg(X86::RIP); // Section 2.2.1.6
818       }
819       else
820         baseReg = MCOperand::createReg(0);
821 
822       indexReg = MCOperand::createReg(0);
823       break;
824     case EA_BASE_BX_SI:
825       baseReg = MCOperand::createReg(X86::BX);
826       indexReg = MCOperand::createReg(X86::SI);
827       break;
828     case EA_BASE_BX_DI:
829       baseReg = MCOperand::createReg(X86::BX);
830       indexReg = MCOperand::createReg(X86::DI);
831       break;
832     case EA_BASE_BP_SI:
833       baseReg = MCOperand::createReg(X86::BP);
834       indexReg = MCOperand::createReg(X86::SI);
835       break;
836     case EA_BASE_BP_DI:
837       baseReg = MCOperand::createReg(X86::BP);
838       indexReg = MCOperand::createReg(X86::DI);
839       break;
840     default:
841       indexReg = MCOperand::createReg(0);
842       switch (insn.eaBase) {
843       default:
844         debug("Unexpected eaBase");
845         return true;
846         // Here, we will use the fill-ins defined above.  However,
847         //   BX_SI, BX_DI, BP_SI, and BP_DI are all handled above and
848         //   sib and sib64 were handled in the top-level if, so they're only
849         //   placeholders to keep the compiler happy.
850 #define ENTRY(x)                                        \
851       case EA_BASE_##x:                                 \
852         baseReg = MCOperand::createReg(X86::x); break;
853       ALL_EA_BASES
854 #undef ENTRY
855 #define ENTRY(x) case EA_REG_##x:
856       ALL_REGS
857 #undef ENTRY
858         debug("A R/M memory operand may not be a register; "
859               "the base field must be a base.");
860         return true;
861       }
862     }
863 
864     scaleAmount = MCOperand::createImm(1);
865   }
866 
867   displacement = MCOperand::createImm(insn.displacement);
868 
869   segmentReg = MCOperand::createReg(segmentRegnums[insn.segmentOverride]);
870 
871   mcInst.addOperand(baseReg);
872   mcInst.addOperand(scaleAmount);
873   mcInst.addOperand(indexReg);
874   if(!tryAddingSymbolicOperand(insn.displacement + pcrel, false,
875                                insn.startLocation, insn.displacementOffset,
876                                insn.displacementSize, mcInst, Dis))
877     mcInst.addOperand(displacement);
878   mcInst.addOperand(segmentReg);
879   return false;
880 }
881 
882 /// translateRM - Translates an operand stored in the R/M (and possibly SIB)
883 ///   byte of an instruction to LLVM form, and appends it to an MCInst.
884 ///
885 /// @param mcInst       - The MCInst to append to.
886 /// @param operand      - The operand, as stored in the descriptor table.
887 /// @param insn         - The instruction to extract Mod, R/M, and SIB fields
888 ///                       from.
889 /// @return             - 0 on success; nonzero otherwise
translateRM(MCInst & mcInst,const OperandSpecifier & operand,InternalInstruction & insn,const MCDisassembler * Dis)890 static bool translateRM(MCInst &mcInst, const OperandSpecifier &operand,
891                         InternalInstruction &insn, const MCDisassembler *Dis) {
892   switch (operand.type) {
893   default:
894     debug("Unexpected type for a R/M operand");
895     return true;
896   case TYPE_R8:
897   case TYPE_R16:
898   case TYPE_R32:
899   case TYPE_R64:
900   case TYPE_Rv:
901   case TYPE_MM64:
902   case TYPE_XMM32:
903   case TYPE_XMM64:
904   case TYPE_XMM128:
905   case TYPE_XMM256:
906   case TYPE_XMM512:
907   case TYPE_VK1:
908   case TYPE_VK2:
909   case TYPE_VK4:
910   case TYPE_VK8:
911   case TYPE_VK16:
912   case TYPE_VK32:
913   case TYPE_VK64:
914   case TYPE_DEBUGREG:
915   case TYPE_CONTROLREG:
916   case TYPE_BNDR:
917     return translateRMRegister(mcInst, insn);
918   case TYPE_M:
919   case TYPE_M8:
920   case TYPE_M16:
921   case TYPE_M32:
922   case TYPE_M64:
923   case TYPE_M128:
924   case TYPE_M256:
925   case TYPE_M512:
926   case TYPE_Mv:
927   case TYPE_M32FP:
928   case TYPE_M64FP:
929   case TYPE_M80FP:
930   case TYPE_M1616:
931   case TYPE_M1632:
932   case TYPE_M1664:
933   case TYPE_LEA:
934     return translateRMMemory(mcInst, insn, Dis);
935   }
936 }
937 
938 /// translateFPRegister - Translates a stack position on the FPU stack to its
939 ///   LLVM form, and appends it to an MCInst.
940 ///
941 /// @param mcInst       - The MCInst to append to.
942 /// @param stackPos     - The stack position to translate.
translateFPRegister(MCInst & mcInst,uint8_t stackPos)943 static void translateFPRegister(MCInst &mcInst,
944                                 uint8_t stackPos) {
945   mcInst.addOperand(MCOperand::createReg(X86::ST0 + stackPos));
946 }
947 
948 /// translateMaskRegister - Translates a 3-bit mask register number to
949 ///   LLVM form, and appends it to an MCInst.
950 ///
951 /// @param mcInst       - The MCInst to append to.
952 /// @param maskRegNum   - Number of mask register from 0 to 7.
953 /// @return             - false on success; true otherwise.
translateMaskRegister(MCInst & mcInst,uint8_t maskRegNum)954 static bool translateMaskRegister(MCInst &mcInst,
955                                 uint8_t maskRegNum) {
956   if (maskRegNum >= 8) {
957     debug("Invalid mask register number");
958     return true;
959   }
960 
961   mcInst.addOperand(MCOperand::createReg(X86::K0 + maskRegNum));
962   return false;
963 }
964 
965 /// translateOperand - Translates an operand stored in an internal instruction
966 ///   to LLVM's format and appends it to an MCInst.
967 ///
968 /// @param mcInst       - The MCInst to append to.
969 /// @param operand      - The operand, as stored in the descriptor table.
970 /// @param insn         - The internal instruction.
971 /// @return             - false on success; true otherwise.
translateOperand(MCInst & mcInst,const OperandSpecifier & operand,InternalInstruction & insn,const MCDisassembler * Dis)972 static bool translateOperand(MCInst &mcInst, const OperandSpecifier &operand,
973                              InternalInstruction &insn,
974                              const MCDisassembler *Dis) {
975   switch (operand.encoding) {
976   default:
977     debug("Unhandled operand encoding during translation");
978     return true;
979   case ENCODING_REG:
980     translateRegister(mcInst, insn.reg);
981     return false;
982   case ENCODING_WRITEMASK:
983     return translateMaskRegister(mcInst, insn.writemask);
984   CASE_ENCODING_RM:
985     return translateRM(mcInst, operand, insn, Dis);
986   case ENCODING_IB:
987   case ENCODING_IW:
988   case ENCODING_ID:
989   case ENCODING_IO:
990   case ENCODING_Iv:
991   case ENCODING_Ia:
992     translateImmediate(mcInst,
993                        insn.immediates[insn.numImmediatesTranslated++],
994                        operand,
995                        insn,
996                        Dis);
997     return false;
998   case ENCODING_SI:
999     return translateSrcIndex(mcInst, insn);
1000   case ENCODING_DI:
1001     return translateDstIndex(mcInst, insn);
1002   case ENCODING_RB:
1003   case ENCODING_RW:
1004   case ENCODING_RD:
1005   case ENCODING_RO:
1006   case ENCODING_Rv:
1007     translateRegister(mcInst, insn.opcodeRegister);
1008     return false;
1009   case ENCODING_FP:
1010     translateFPRegister(mcInst, insn.modRM & 7);
1011     return false;
1012   case ENCODING_VVVV:
1013     translateRegister(mcInst, insn.vvvv);
1014     return false;
1015   case ENCODING_DUP:
1016     return translateOperand(mcInst, insn.operands[operand.type - TYPE_DUP0],
1017                             insn, Dis);
1018   }
1019 }
1020 
1021 /// translateInstruction - Translates an internal instruction and all its
1022 ///   operands to an MCInst.
1023 ///
1024 /// @param mcInst       - The MCInst to populate with the instruction's data.
1025 /// @param insn         - The internal instruction.
1026 /// @return             - false on success; true otherwise.
translateInstruction(MCInst & mcInst,InternalInstruction & insn,const MCDisassembler * Dis)1027 static bool translateInstruction(MCInst &mcInst,
1028                                 InternalInstruction &insn,
1029                                 const MCDisassembler *Dis) {
1030   if (!insn.spec) {
1031     debug("Instruction has no specification");
1032     return true;
1033   }
1034 
1035   mcInst.clear();
1036   mcInst.setOpcode(insn.instructionID);
1037   // If when reading the prefix bytes we determined the overlapping 0xf2 or 0xf3
1038   // prefix bytes should be disassembled as xrelease and xacquire then set the
1039   // opcode to those instead of the rep and repne opcodes.
1040   if (insn.xAcquireRelease) {
1041     if(mcInst.getOpcode() == X86::REP_PREFIX)
1042       mcInst.setOpcode(X86::XRELEASE_PREFIX);
1043     else if(mcInst.getOpcode() == X86::REPNE_PREFIX)
1044       mcInst.setOpcode(X86::XACQUIRE_PREFIX);
1045   }
1046 
1047   insn.numImmediatesTranslated = 0;
1048 
1049   for (const auto &Op : insn.operands) {
1050     if (Op.encoding != ENCODING_NONE) {
1051       if (translateOperand(mcInst, Op, insn, Dis)) {
1052         return true;
1053       }
1054     }
1055   }
1056 
1057   return false;
1058 }
1059 
createX86Disassembler(const Target & T,const MCSubtargetInfo & STI,MCContext & Ctx)1060 static MCDisassembler *createX86Disassembler(const Target &T,
1061                                              const MCSubtargetInfo &STI,
1062                                              MCContext &Ctx) {
1063   std::unique_ptr<const MCInstrInfo> MII(T.createMCInstrInfo());
1064   return new X86GenericDisassembler(STI, Ctx, std::move(MII));
1065 }
1066 
LLVMInitializeX86Disassembler()1067 extern "C" void LLVMInitializeX86Disassembler() {
1068   // Register the disassembler.
1069   TargetRegistry::RegisterMCDisassembler(TheX86_32Target,
1070                                          createX86Disassembler);
1071   TargetRegistry::RegisterMCDisassembler(TheX86_64Target,
1072                                          createX86Disassembler);
1073 }
1074