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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // A Disassembler object is used to disassemble a block of code instruction by
      6 // instruction. The default implementation of the NameConverter object can be
      7 // overriden to modify register names or to do symbol lookup on addresses.
      8 //
      9 // The example below will disassemble a block of code and print it to stdout.
     10 //
     11 //   NameConverter converter;
     12 //   Disassembler d(converter);
     13 //   for (byte* pc = begin; pc < end;) {
     14 //     v8::internal::EmbeddedVector<char, 256> buffer;
     15 //     byte* prev_pc = pc;
     16 //     pc += d.InstructionDecode(buffer, pc);
     17 //     printf("%p    %08x      %s\n",
     18 //            prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer);
     19 //   }
     20 //
     21 // The Disassembler class also has a convenience method to disassemble a block
     22 // of code into a FILE*, meaning that the above functionality could also be
     23 // achieved by just calling Disassembler::Disassemble(stdout, begin, end);
     24 
     25 
     26 #include <assert.h>
     27 #include <stdarg.h>
     28 #include <stdio.h>
     29 #include <string.h>
     30 
     31 #include "src/v8.h"
     32 
     33 #if V8_TARGET_ARCH_MIPS64
     34 
     35 #include "src/base/platform/platform.h"
     36 #include "src/disasm.h"
     37 #include "src/macro-assembler.h"
     38 #include "src/mips64/constants-mips64.h"
     39 
     40 namespace v8 {
     41 namespace internal {
     42 
     43 //------------------------------------------------------------------------------
     44 
     45 // Decoder decodes and disassembles instructions into an output buffer.
     46 // It uses the converter to convert register names and call destinations into
     47 // more informative description.
     48 class Decoder {
     49  public:
     50   Decoder(const disasm::NameConverter& converter,
     51           v8::internal::Vector<char> out_buffer)
     52     : converter_(converter),
     53       out_buffer_(out_buffer),
     54       out_buffer_pos_(0) {
     55     out_buffer_[out_buffer_pos_] = '\0';
     56   }
     57 
     58   ~Decoder() {}
     59 
     60   // Writes one disassembled instruction into 'buffer' (0-terminated).
     61   // Returns the length of the disassembled machine instruction in bytes.
     62   int InstructionDecode(byte* instruction);
     63 
     64  private:
     65   // Bottleneck functions to print into the out_buffer.
     66   void PrintChar(const char ch);
     67   void Print(const char* str);
     68 
     69   // Printing of common values.
     70   void PrintRegister(int reg);
     71   void PrintFPURegister(int freg);
     72   void PrintRs(Instruction* instr);
     73   void PrintRt(Instruction* instr);
     74   void PrintRd(Instruction* instr);
     75   void PrintFs(Instruction* instr);
     76   void PrintFt(Instruction* instr);
     77   void PrintFd(Instruction* instr);
     78   void PrintSa(Instruction* instr);
     79   void PrintSd(Instruction* instr);
     80   void PrintSs1(Instruction* instr);
     81   void PrintSs2(Instruction* instr);
     82   void PrintBc(Instruction* instr);
     83   void PrintCc(Instruction* instr);
     84   void PrintFunction(Instruction* instr);
     85   void PrintSecondaryField(Instruction* instr);
     86   void PrintUImm16(Instruction* instr);
     87   void PrintSImm16(Instruction* instr);
     88   void PrintXImm16(Instruction* instr);
     89   void PrintXImm21(Instruction* instr);
     90   void PrintXImm26(Instruction* instr);
     91   void PrintCode(Instruction* instr);   // For break and trap instructions.
     92   // Printing of instruction name.
     93   void PrintInstructionName(Instruction* instr);
     94 
     95   // Handle formatting of instructions and their options.
     96   int FormatRegister(Instruction* instr, const char* option);
     97   int FormatFPURegister(Instruction* instr, const char* option);
     98   int FormatOption(Instruction* instr, const char* option);
     99   void Format(Instruction* instr, const char* format);
    100   void Unknown(Instruction* instr);
    101   int DecodeBreakInstr(Instruction* instr);
    102 
    103   // Each of these functions decodes one particular instruction type.
    104   int DecodeTypeRegister(Instruction* instr);
    105   void DecodeTypeImmediate(Instruction* instr);
    106   void DecodeTypeJump(Instruction* instr);
    107 
    108   const disasm::NameConverter& converter_;
    109   v8::internal::Vector<char> out_buffer_;
    110   int out_buffer_pos_;
    111 
    112   DISALLOW_COPY_AND_ASSIGN(Decoder);
    113 };
    114 
    115 
    116 // Support for assertions in the Decoder formatting functions.
    117 #define STRING_STARTS_WITH(string, compare_string) \
    118   (strncmp(string, compare_string, strlen(compare_string)) == 0)
    119 
    120 
    121 // Append the ch to the output buffer.
    122 void Decoder::PrintChar(const char ch) {
    123   out_buffer_[out_buffer_pos_++] = ch;
    124 }
    125 
    126 
    127 // Append the str to the output buffer.
    128 void Decoder::Print(const char* str) {
    129   char cur = *str++;
    130   while (cur != '\0' && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
    131     PrintChar(cur);
    132     cur = *str++;
    133   }
    134   out_buffer_[out_buffer_pos_] = 0;
    135 }
    136 
    137 
    138 // Print the register name according to the active name converter.
    139 void Decoder::PrintRegister(int reg) {
    140   Print(converter_.NameOfCPURegister(reg));
    141 }
    142 
    143 
    144 void Decoder::PrintRs(Instruction* instr) {
    145   int reg = instr->RsValue();
    146   PrintRegister(reg);
    147 }
    148 
    149 
    150 void Decoder::PrintRt(Instruction* instr) {
    151   int reg = instr->RtValue();
    152   PrintRegister(reg);
    153 }
    154 
    155 
    156 void Decoder::PrintRd(Instruction* instr) {
    157   int reg = instr->RdValue();
    158   PrintRegister(reg);
    159 }
    160 
    161 
    162 // Print the FPUregister name according to the active name converter.
    163 void Decoder::PrintFPURegister(int freg) {
    164   Print(converter_.NameOfXMMRegister(freg));
    165 }
    166 
    167 
    168 void Decoder::PrintFs(Instruction* instr) {
    169   int freg = instr->RsValue();
    170   PrintFPURegister(freg);
    171 }
    172 
    173 
    174 void Decoder::PrintFt(Instruction* instr) {
    175   int freg = instr->RtValue();
    176   PrintFPURegister(freg);
    177 }
    178 
    179 
    180 void Decoder::PrintFd(Instruction* instr) {
    181   int freg = instr->RdValue();
    182   PrintFPURegister(freg);
    183 }
    184 
    185 
    186 // Print the integer value of the sa field.
    187 void Decoder::PrintSa(Instruction* instr) {
    188   int sa = instr->SaValue();
    189   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", sa);
    190 }
    191 
    192 
    193 // Print the integer value of the rd field, when it is not used as reg.
    194 void Decoder::PrintSd(Instruction* instr) {
    195   int sd = instr->RdValue();
    196   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", sd);
    197 }
    198 
    199 
    200 // Print the integer value of the rd field, when used as 'ext' size.
    201 void Decoder::PrintSs1(Instruction* instr) {
    202   int ss = instr->RdValue();
    203   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", ss + 1);
    204 }
    205 
    206 
    207 // Print the integer value of the rd field, when used as 'ins' size.
    208 void Decoder::PrintSs2(Instruction* instr) {
    209   int ss = instr->RdValue();
    210   int pos = instr->SaValue();
    211   out_buffer_pos_ +=
    212       SNPrintF(out_buffer_ + out_buffer_pos_, "%d", ss - pos + 1);
    213 }
    214 
    215 
    216 // Print the integer value of the cc field for the bc1t/f instructions.
    217 void Decoder::PrintBc(Instruction* instr) {
    218   int cc = instr->FBccValue();
    219   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", cc);
    220 }
    221 
    222 
    223 // Print the integer value of the cc field for the FP compare instructions.
    224 void Decoder::PrintCc(Instruction* instr) {
    225   int cc = instr->FCccValue();
    226   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "cc(%d)", cc);
    227 }
    228 
    229 
    230 // Print 16-bit unsigned immediate value.
    231 void Decoder::PrintUImm16(Instruction* instr) {
    232   int32_t imm = instr->Imm16Value();
    233   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%u", imm);
    234 }
    235 
    236 
    237 // Print 16-bit signed immediate value.
    238 void Decoder::PrintSImm16(Instruction* instr) {
    239   int32_t imm = ((instr->Imm16Value()) << 16) >> 16;
    240   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", imm);
    241 }
    242 
    243 
    244 // Print 16-bit hexa immediate value.
    245 void Decoder::PrintXImm16(Instruction* instr) {
    246   int32_t imm = instr->Imm16Value();
    247   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "0x%x", imm);
    248 }
    249 
    250 
    251 // Print 21-bit immediate value.
    252 void Decoder::PrintXImm21(Instruction* instr) {
    253   uint32_t imm = instr->Imm21Value();
    254   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "0x%x", imm);
    255 }
    256 
    257 
    258 // Print 26-bit immediate value.
    259 void Decoder::PrintXImm26(Instruction* instr) {
    260   uint32_t imm = instr->Imm26Value() << kImmFieldShift;
    261   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "0x%x", imm);
    262 }
    263 
    264 
    265 // Print 26-bit immediate value.
    266 void Decoder::PrintCode(Instruction* instr) {
    267   if (instr->OpcodeFieldRaw() != SPECIAL)
    268     return;  // Not a break or trap instruction.
    269   switch (instr->FunctionFieldRaw()) {
    270     case BREAK: {
    271       int32_t code = instr->Bits(25, 6);
    272       out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
    273                                   "0x%05x (%d)", code, code);
    274       break;
    275                 }
    276     case TGE:
    277     case TGEU:
    278     case TLT:
    279     case TLTU:
    280     case TEQ:
    281     case TNE: {
    282       int32_t code = instr->Bits(15, 6);
    283       out_buffer_pos_ +=
    284           SNPrintF(out_buffer_ + out_buffer_pos_, "0x%03x", code);
    285       break;
    286     }
    287     default:  // Not a break or trap instruction.
    288     break;
    289   }
    290 }
    291 
    292 
    293 // Printing of instruction name.
    294 void Decoder::PrintInstructionName(Instruction* instr) {
    295 }
    296 
    297 
    298 // Handle all register based formatting in this function to reduce the
    299 // complexity of FormatOption.
    300 int Decoder::FormatRegister(Instruction* instr, const char* format) {
    301   DCHECK(format[0] == 'r');
    302   if (format[1] == 's') {  // 'rs: Rs register.
    303     int reg = instr->RsValue();
    304     PrintRegister(reg);
    305     return 2;
    306   } else if (format[1] == 't') {  // 'rt: rt register.
    307     int reg = instr->RtValue();
    308     PrintRegister(reg);
    309     return 2;
    310   } else if (format[1] == 'd') {  // 'rd: rd register.
    311     int reg = instr->RdValue();
    312     PrintRegister(reg);
    313     return 2;
    314   }
    315   UNREACHABLE();
    316   return -1;
    317 }
    318 
    319 
    320 // Handle all FPUregister based formatting in this function to reduce the
    321 // complexity of FormatOption.
    322 int Decoder::FormatFPURegister(Instruction* instr, const char* format) {
    323   DCHECK(format[0] == 'f');
    324   if (format[1] == 's') {  // 'fs: fs register.
    325     int reg = instr->FsValue();
    326     PrintFPURegister(reg);
    327     return 2;
    328   } else if (format[1] == 't') {  // 'ft: ft register.
    329     int reg = instr->FtValue();
    330     PrintFPURegister(reg);
    331     return 2;
    332   } else if (format[1] == 'd') {  // 'fd: fd register.
    333     int reg = instr->FdValue();
    334     PrintFPURegister(reg);
    335     return 2;
    336   } else if (format[1] == 'r') {  // 'fr: fr register.
    337     int reg = instr->FrValue();
    338     PrintFPURegister(reg);
    339     return 2;
    340   }
    341   UNREACHABLE();
    342   return -1;
    343 }
    344 
    345 
    346 // FormatOption takes a formatting string and interprets it based on
    347 // the current instructions. The format string points to the first
    348 // character of the option string (the option escape has already been
    349 // consumed by the caller.)  FormatOption returns the number of
    350 // characters that were consumed from the formatting string.
    351 int Decoder::FormatOption(Instruction* instr, const char* format) {
    352   switch (format[0]) {
    353     case 'c': {   // 'code for break or trap instructions.
    354       DCHECK(STRING_STARTS_WITH(format, "code"));
    355       PrintCode(instr);
    356       return 4;
    357     }
    358     case 'i': {   // 'imm16u or 'imm26.
    359       if (format[3] == '1') {
    360         DCHECK(STRING_STARTS_WITH(format, "imm16"));
    361         if (format[5] == 's') {
    362           DCHECK(STRING_STARTS_WITH(format, "imm16s"));
    363           PrintSImm16(instr);
    364         } else if (format[5] == 'u') {
    365           DCHECK(STRING_STARTS_WITH(format, "imm16u"));
    366           PrintSImm16(instr);
    367         } else {
    368           DCHECK(STRING_STARTS_WITH(format, "imm16x"));
    369           PrintXImm16(instr);
    370         }
    371         return 6;
    372       } else if (format[3] == '2' && format[4] == '1') {
    373         DCHECK(STRING_STARTS_WITH(format, "imm21x"));
    374         PrintXImm21(instr);
    375         return 6;
    376       } else if (format[3] == '2' && format[4] == '6') {
    377         DCHECK(STRING_STARTS_WITH(format, "imm26x"));
    378         PrintXImm26(instr);
    379         return 6;
    380       }
    381     }
    382     case 'r': {   // 'r: registers.
    383       return FormatRegister(instr, format);
    384     }
    385     case 'f': {   // 'f: FPUregisters.
    386       return FormatFPURegister(instr, format);
    387     }
    388     case 's': {   // 'sa.
    389       switch (format[1]) {
    390         case 'a': {
    391           DCHECK(STRING_STARTS_WITH(format, "sa"));
    392           PrintSa(instr);
    393           return 2;
    394         }
    395         case 'd': {
    396           DCHECK(STRING_STARTS_WITH(format, "sd"));
    397           PrintSd(instr);
    398           return 2;
    399         }
    400         case 's': {
    401           if (format[2] == '1') {
    402               DCHECK(STRING_STARTS_WITH(format, "ss1"));  /* ext size */
    403               PrintSs1(instr);
    404               return 3;
    405           } else {
    406               DCHECK(STRING_STARTS_WITH(format, "ss2"));  /* ins size */
    407               PrintSs2(instr);
    408               return 3;
    409           }
    410         }
    411       }
    412     }
    413     case 'b': {   // 'bc - Special for bc1 cc field.
    414       DCHECK(STRING_STARTS_WITH(format, "bc"));
    415       PrintBc(instr);
    416       return 2;
    417     }
    418     case 'C': {   // 'Cc - Special for c.xx.d cc field.
    419       DCHECK(STRING_STARTS_WITH(format, "Cc"));
    420       PrintCc(instr);
    421       return 2;
    422     }
    423   }
    424   UNREACHABLE();
    425   return -1;
    426 }
    427 
    428 
    429 // Format takes a formatting string for a whole instruction and prints it into
    430 // the output buffer. All escaped options are handed to FormatOption to be
    431 // parsed further.
    432 void Decoder::Format(Instruction* instr, const char* format) {
    433   char cur = *format++;
    434   while ((cur != 0) && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
    435     if (cur == '\'') {  // Single quote is used as the formatting escape.
    436       format += FormatOption(instr, format);
    437     } else {
    438       out_buffer_[out_buffer_pos_++] = cur;
    439     }
    440     cur = *format++;
    441   }
    442   out_buffer_[out_buffer_pos_]  = '\0';
    443 }
    444 
    445 
    446 // For currently unimplemented decodings the disassembler calls Unknown(instr)
    447 // which will just print "unknown" of the instruction bits.
    448 void Decoder::Unknown(Instruction* instr) {
    449   Format(instr, "unknown");
    450 }
    451 
    452 
    453 int Decoder::DecodeBreakInstr(Instruction* instr) {
    454   // This is already known to be BREAK instr, just extract the code.
    455   if (instr->Bits(25, 6) == static_cast<int>(kMaxStopCode)) {
    456     // This is stop(msg).
    457     Format(instr, "break, code: 'code");
    458     out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
    459                                 "\n%p       %08lx       stop msg: %s",
    460                                 static_cast<void*>
    461                                       (reinterpret_cast<int32_t*>(instr
    462                                               + Instruction::kInstrSize)),
    463                                 reinterpret_cast<uint64_t>
    464                                 (*reinterpret_cast<char**>(instr
    465                                               + Instruction::kInstrSize)),
    466                                 *reinterpret_cast<char**>(instr
    467                                               + Instruction::kInstrSize));
    468     // Size 3: the break_ instr, plus embedded 64-bit char pointer.
    469     return 3 * Instruction::kInstrSize;
    470   } else {
    471     Format(instr, "break, code: 'code");
    472     return Instruction::kInstrSize;
    473   }
    474 }
    475 
    476 
    477 int Decoder::DecodeTypeRegister(Instruction* instr) {
    478   switch (instr->OpcodeFieldRaw()) {
    479     case COP1:    // Coprocessor instructions.
    480       switch (instr->RsFieldRaw()) {
    481         case MFC1:
    482           Format(instr, "mfc1    'rt, 'fs");
    483           break;
    484         case DMFC1:
    485           Format(instr, "dmfc1    'rt, 'fs");
    486           break;
    487         case MFHC1:
    488           Format(instr, "mfhc1   'rt, 'fs");
    489           break;
    490         case MTC1:
    491           Format(instr, "mtc1    'rt, 'fs");
    492           break;
    493         case DMTC1:
    494           Format(instr, "dmtc1    'rt, 'fs");
    495           break;
    496         // These are called "fs" too, although they are not FPU registers.
    497         case CTC1:
    498           Format(instr, "ctc1    'rt, 'fs");
    499           break;
    500         case CFC1:
    501           Format(instr, "cfc1    'rt, 'fs");
    502           break;
    503         case MTHC1:
    504           Format(instr, "mthc1   'rt, 'fs");
    505           break;
    506         case D:
    507           switch (instr->FunctionFieldRaw()) {
    508             case ADD_D:
    509               Format(instr, "add.d   'fd, 'fs, 'ft");
    510               break;
    511             case SUB_D:
    512               Format(instr, "sub.d   'fd, 'fs, 'ft");
    513               break;
    514             case MUL_D:
    515               Format(instr, "mul.d   'fd, 'fs, 'ft");
    516               break;
    517             case DIV_D:
    518               Format(instr, "div.d   'fd, 'fs, 'ft");
    519               break;
    520             case ABS_D:
    521               Format(instr, "abs.d   'fd, 'fs");
    522               break;
    523             case MOV_D:
    524               Format(instr, "mov.d   'fd, 'fs");
    525               break;
    526             case NEG_D:
    527               Format(instr, "neg.d   'fd, 'fs");
    528               break;
    529             case SQRT_D:
    530               Format(instr, "sqrt.d  'fd, 'fs");
    531               break;
    532             case CVT_W_D:
    533               Format(instr, "cvt.w.d 'fd, 'fs");
    534               break;
    535             case CVT_L_D:
    536               Format(instr, "cvt.l.d 'fd, 'fs");
    537               break;
    538             case TRUNC_W_D:
    539               Format(instr, "trunc.w.d 'fd, 'fs");
    540               break;
    541             case TRUNC_L_D:
    542               Format(instr, "trunc.l.d 'fd, 'fs");
    543               break;
    544             case ROUND_W_D:
    545               Format(instr, "round.w.d 'fd, 'fs");
    546               break;
    547             case ROUND_L_D:
    548               Format(instr, "round.l.d 'fd, 'fs");
    549               break;
    550             case FLOOR_W_D:
    551               Format(instr, "floor.w.d 'fd, 'fs");
    552               break;
    553             case FLOOR_L_D:
    554               Format(instr, "floor.l.d 'fd, 'fs");
    555               break;
    556             case CEIL_W_D:
    557               Format(instr, "ceil.w.d 'fd, 'fs");
    558               break;
    559             case CEIL_L_D:
    560               Format(instr, "ceil.l.d 'fd, 'fs");
    561               break;
    562             case CVT_S_D:
    563               Format(instr, "cvt.s.d 'fd, 'fs");
    564               break;
    565             case C_F_D:
    566               Format(instr, "c.f.d   'fs, 'ft, 'Cc");
    567               break;
    568             case C_UN_D:
    569               Format(instr, "c.un.d  'fs, 'ft, 'Cc");
    570               break;
    571             case C_EQ_D:
    572               Format(instr, "c.eq.d  'fs, 'ft, 'Cc");
    573               break;
    574             case C_UEQ_D:
    575               Format(instr, "c.ueq.d 'fs, 'ft, 'Cc");
    576               break;
    577             case C_OLT_D:
    578               Format(instr, "c.olt.d 'fs, 'ft, 'Cc");
    579               break;
    580             case C_ULT_D:
    581               Format(instr, "c.ult.d 'fs, 'ft, 'Cc");
    582               break;
    583             case C_OLE_D:
    584               Format(instr, "c.ole.d 'fs, 'ft, 'Cc");
    585               break;
    586             case C_ULE_D:
    587               Format(instr, "c.ule.d 'fs, 'ft, 'Cc");
    588               break;
    589             default:
    590               Format(instr, "unknown.cop1.d");
    591               break;
    592           }
    593           break;
    594         case W:
    595           switch (instr->FunctionFieldRaw()) {
    596             case CVT_D_W:   // Convert word to double.
    597               Format(instr, "cvt.d.w 'fd, 'fs");
    598               break;
    599             default:
    600               UNREACHABLE();
    601           }
    602           break;
    603         case L:
    604           switch (instr->FunctionFieldRaw()) {
    605             case CVT_D_L:
    606               Format(instr, "cvt.d.l 'fd, 'fs");
    607               break;
    608             case CVT_S_L:
    609               Format(instr, "cvt.s.l 'fd, 'fs");
    610               break;
    611             case CMP_UN:
    612               Format(instr, "cmp.un.d  'fd,  'fs, 'ft");
    613               break;
    614             case CMP_EQ:
    615               Format(instr, "cmp.eq.d  'fd,  'fs, 'ft");
    616               break;
    617             case CMP_UEQ:
    618               Format(instr, "cmp.ueq.d  'fd,  'fs, 'ft");
    619               break;
    620             case CMP_LT:
    621               Format(instr, "cmp.lt.d  'fd,  'fs, 'ft");
    622               break;
    623             case CMP_ULT:
    624               Format(instr, "cmp.ult.d  'fd,  'fs, 'ft");
    625               break;
    626             case CMP_LE:
    627               Format(instr, "cmp.le.d  'fd,  'fs, 'ft");
    628               break;
    629             case CMP_ULE:
    630               Format(instr, "cmp.ule.d  'fd,  'fs, 'ft");
    631               break;
    632             case CMP_OR:
    633               Format(instr, "cmp.or.d  'fd,  'fs, 'ft");
    634               break;
    635             case CMP_UNE:
    636               Format(instr, "cmp.une.d  'fd,  'fs, 'ft");
    637               break;
    638             case CMP_NE:
    639               Format(instr, "cmp.ne.d  'fd,  'fs, 'ft");
    640               break;
    641             default:
    642               UNREACHABLE();
    643           }
    644           break;
    645         default:
    646           UNREACHABLE();
    647       }
    648       break;
    649     case COP1X:
    650       switch (instr->FunctionFieldRaw()) {
    651         case MADD_D:
    652           Format(instr, "madd.d  'fd, 'fr, 'fs, 'ft");
    653           break;
    654         default:
    655           UNREACHABLE();
    656       }
    657       break;
    658     case SPECIAL:
    659       switch (instr->FunctionFieldRaw()) {
    660         case JR:
    661           Format(instr, "jr      'rs");
    662           break;
    663         case JALR:
    664           Format(instr, "jalr    'rs");
    665           break;
    666         case SLL:
    667           if (0x0 == static_cast<int>(instr->InstructionBits()))
    668             Format(instr, "nop");
    669           else
    670             Format(instr, "sll     'rd, 'rt, 'sa");
    671           break;
    672         case DSLL:
    673             Format(instr, "dsll    'rd, 'rt, 'sa");
    674           break;
    675         case D_MUL_MUH:  // Equals to DMUL.
    676           if (kArchVariant != kMips64r6) {
    677             Format(instr, "dmult   'rs, 'rt");
    678           } else {
    679             if (instr->SaValue() == MUL_OP) {
    680               Format(instr, "dmul   'rd, 'rs, 'rt");
    681             } else {
    682               Format(instr, "dmuh   'rd, 'rs, 'rt");
    683             }
    684           }
    685           break;
    686         case DSLL32:
    687           Format(instr, "dsll32  'rd, 'rt, 'sa");
    688           break;
    689         case SRL:
    690           if (instr->RsValue() == 0) {
    691             Format(instr, "srl     'rd, 'rt, 'sa");
    692           } else {
    693             if (kArchVariant == kMips64r2) {
    694               Format(instr, "rotr    'rd, 'rt, 'sa");
    695             } else {
    696               Unknown(instr);
    697             }
    698           }
    699           break;
    700         case DSRL:
    701           if (instr->RsValue() == 0) {
    702             Format(instr, "dsrl    'rd, 'rt, 'sa");
    703           } else {
    704             if (kArchVariant == kMips64r2) {
    705               Format(instr, "drotr   'rd, 'rt, 'sa");
    706             } else {
    707               Unknown(instr);
    708             }
    709           }
    710           break;
    711         case DSRL32:
    712           Format(instr, "dsrl32  'rd, 'rt, 'sa");
    713           break;
    714         case SRA:
    715           Format(instr, "sra     'rd, 'rt, 'sa");
    716           break;
    717         case DSRA:
    718           Format(instr, "dsra    'rd, 'rt, 'sa");
    719           break;
    720         case DSRA32:
    721           Format(instr, "dsra32  'rd, 'rt, 'sa");
    722           break;
    723         case SLLV:
    724           Format(instr, "sllv    'rd, 'rt, 'rs");
    725           break;
    726         case DSLLV:
    727           Format(instr, "dsllv   'rd, 'rt, 'rs");
    728           break;
    729         case SRLV:
    730           if (instr->SaValue() == 0) {
    731             Format(instr, "srlv    'rd, 'rt, 'rs");
    732           } else {
    733             if (kArchVariant == kMips64r2) {
    734               Format(instr, "rotrv   'rd, 'rt, 'rs");
    735             } else {
    736               Unknown(instr);
    737             }
    738           }
    739           break;
    740         case DSRLV:
    741           if (instr->SaValue() == 0) {
    742             Format(instr, "dsrlv   'rd, 'rt, 'rs");
    743           } else {
    744             if (kArchVariant == kMips64r2) {
    745               Format(instr, "drotrv  'rd, 'rt, 'rs");
    746             } else {
    747               Unknown(instr);
    748             }
    749           }
    750           break;
    751         case SRAV:
    752           Format(instr, "srav    'rd, 'rt, 'rs");
    753           break;
    754         case DSRAV:
    755           Format(instr, "dsrav   'rd, 'rt, 'rs");
    756           break;
    757         case MFHI:
    758           if (instr->Bits(25, 16) == 0) {
    759             Format(instr, "mfhi    'rd");
    760           } else {
    761             if ((instr->FunctionFieldRaw() == CLZ_R6)
    762                 && (instr->FdValue() == 1)) {
    763               Format(instr, "clz     'rd, 'rs");
    764             } else if ((instr->FunctionFieldRaw() == CLO_R6)
    765                 && (instr->FdValue() == 1)) {
    766               Format(instr, "clo     'rd, 'rs");
    767             }
    768           }
    769           break;
    770         case MFLO:
    771           Format(instr, "mflo    'rd");
    772           break;
    773         case D_MUL_MUH_U:  // Equals to DMULTU.
    774           if (kArchVariant != kMips64r6) {
    775               Format(instr, "dmultu  'rs, 'rt");
    776           } else {
    777             if (instr->SaValue() == MUL_OP) {
    778               Format(instr, "dmulu  'rd, 'rs, 'rt");
    779             } else {
    780               Format(instr, "dmuhu  'rd, 'rs, 'rt");
    781             }
    782           }
    783           break;
    784         case MULT:  // @Mips64r6 == MUL_MUH.
    785           if (kArchVariant != kMips64r6) {
    786             Format(instr, "mult    'rs, 'rt");
    787           } else {
    788             if (instr->SaValue() == MUL_OP) {
    789               Format(instr, "mul    'rd, 'rs, 'rt");
    790             } else {
    791               Format(instr, "muh    'rd, 'rs, 'rt");
    792             }
    793           }
    794           break;
    795         case MULTU:  // @Mips64r6 == MUL_MUH_U.
    796           if (kArchVariant != kMips64r6) {
    797             Format(instr, "multu   'rs, 'rt");
    798           } else {
    799             if (instr->SaValue() == MUL_OP) {
    800               Format(instr, "mulu   'rd, 'rs, 'rt");
    801             } else {
    802               Format(instr, "muhu   'rd, 'rs, 'rt");
    803             }
    804           }
    805 
    806           break;
    807         case DIV:  // @Mips64r6 == DIV_MOD.
    808           if (kArchVariant != kMips64r6) {
    809             Format(instr, "div     'rs, 'rt");
    810           } else {
    811             if (instr->SaValue() == DIV_OP) {
    812               Format(instr, "div    'rd, 'rs, 'rt");
    813             } else {
    814               Format(instr, "mod    'rd, 'rs, 'rt");
    815             }
    816           }
    817           break;
    818         case DDIV:  // @Mips64r6 == D_DIV_MOD.
    819           if (kArchVariant != kMips64r6) {
    820             Format(instr, "ddiv    'rs, 'rt");
    821           } else {
    822             if (instr->SaValue() == DIV_OP) {
    823               Format(instr, "ddiv   'rd, 'rs, 'rt");
    824             } else {
    825               Format(instr, "dmod   'rd, 'rs, 'rt");
    826             }
    827           }
    828           break;
    829         case DIVU:  // @Mips64r6 == DIV_MOD_U.
    830           if (kArchVariant != kMips64r6) {
    831             Format(instr, "divu    'rs, 'rt");
    832           } else {
    833             if (instr->SaValue() == DIV_OP) {
    834               Format(instr, "divu   'rd, 'rs, 'rt");
    835             } else {
    836               Format(instr, "modu   'rd, 'rs, 'rt");
    837             }
    838           }
    839           break;
    840         case DDIVU:  // @Mips64r6 == D_DIV_MOD_U.
    841           if (kArchVariant != kMips64r6) {
    842             Format(instr, "ddivu   'rs, 'rt");
    843           } else {
    844             if (instr->SaValue() == DIV_OP) {
    845               Format(instr, "ddivu  'rd, 'rs, 'rt");
    846             } else {
    847               Format(instr, "dmodu  'rd, 'rs, 'rt");
    848             }
    849           }
    850           break;
    851         case ADD:
    852           Format(instr, "add     'rd, 'rs, 'rt");
    853           break;
    854         case DADD:
    855           Format(instr, "dadd    'rd, 'rs, 'rt");
    856           break;
    857         case ADDU:
    858           Format(instr, "addu    'rd, 'rs, 'rt");
    859           break;
    860         case DADDU:
    861           Format(instr, "daddu   'rd, 'rs, 'rt");
    862           break;
    863         case SUB:
    864           Format(instr, "sub     'rd, 'rs, 'rt");
    865           break;
    866         case DSUB:
    867           Format(instr, "dsub    'rd, 'rs, 'rt");
    868           break;
    869         case SUBU:
    870           Format(instr, "subu    'rd, 'rs, 'rt");
    871           break;
    872         case DSUBU:
    873           Format(instr, "dsubu   'rd, 'rs, 'rt");
    874           break;
    875         case AND:
    876           Format(instr, "and     'rd, 'rs, 'rt");
    877           break;
    878         case OR:
    879           if (0 == instr->RsValue()) {
    880             Format(instr, "mov     'rd, 'rt");
    881           } else if (0 == instr->RtValue()) {
    882             Format(instr, "mov     'rd, 'rs");
    883           } else {
    884             Format(instr, "or      'rd, 'rs, 'rt");
    885           }
    886           break;
    887         case XOR:
    888           Format(instr, "xor     'rd, 'rs, 'rt");
    889           break;
    890         case NOR:
    891           Format(instr, "nor     'rd, 'rs, 'rt");
    892           break;
    893         case SLT:
    894           Format(instr, "slt     'rd, 'rs, 'rt");
    895           break;
    896         case SLTU:
    897           Format(instr, "sltu    'rd, 'rs, 'rt");
    898           break;
    899         case BREAK:
    900           return DecodeBreakInstr(instr);
    901         case TGE:
    902           Format(instr, "tge     'rs, 'rt, code: 'code");
    903           break;
    904         case TGEU:
    905           Format(instr, "tgeu    'rs, 'rt, code: 'code");
    906           break;
    907         case TLT:
    908           Format(instr, "tlt     'rs, 'rt, code: 'code");
    909           break;
    910         case TLTU:
    911           Format(instr, "tltu    'rs, 'rt, code: 'code");
    912           break;
    913         case TEQ:
    914           Format(instr, "teq     'rs, 'rt, code: 'code");
    915           break;
    916         case TNE:
    917           Format(instr, "tne     'rs, 'rt, code: 'code");
    918           break;
    919         case MOVZ:
    920           Format(instr, "movz    'rd, 'rs, 'rt");
    921           break;
    922         case MOVN:
    923           Format(instr, "movn    'rd, 'rs, 'rt");
    924           break;
    925         case MOVCI:
    926           if (instr->Bit(16)) {
    927             Format(instr, "movt    'rd, 'rs, 'bc");
    928           } else {
    929             Format(instr, "movf    'rd, 'rs, 'bc");
    930           }
    931           break;
    932         case SELEQZ_S:
    933           Format(instr, "seleqz    'rd, 'rs, 'rt");
    934           break;
    935         case SELNEZ_S:
    936           Format(instr, "selnez    'rd, 'rs, 'rt");
    937           break;
    938         default:
    939           UNREACHABLE();
    940       }
    941       break;
    942     case SPECIAL2:
    943       switch (instr->FunctionFieldRaw()) {
    944         case MUL:
    945           Format(instr, "mul     'rd, 'rs, 'rt");
    946           break;
    947         case CLZ:
    948           if (kArchVariant != kMips64r6) {
    949             Format(instr, "clz     'rd, 'rs");
    950           }
    951           break;
    952         default:
    953           UNREACHABLE();
    954       }
    955       break;
    956     case SPECIAL3:
    957       switch (instr->FunctionFieldRaw()) {
    958         case INS: {
    959           Format(instr, "ins     'rt, 'rs, 'sa, 'ss2");
    960           break;
    961         }
    962         case EXT: {
    963           Format(instr, "ext     'rt, 'rs, 'sa, 'ss1");
    964           break;
    965         }
    966         default:
    967           UNREACHABLE();
    968       }
    969       break;
    970     default:
    971       UNREACHABLE();
    972   }
    973   return Instruction::kInstrSize;
    974 }
    975 
    976 
    977 void Decoder::DecodeTypeImmediate(Instruction* instr) {
    978   switch (instr->OpcodeFieldRaw()) {
    979     case COP1:
    980       switch (instr->RsFieldRaw()) {
    981         case BC1:
    982           if (instr->FBtrueValue()) {
    983             Format(instr, "bc1t    'bc, 'imm16u");
    984           } else {
    985             Format(instr, "bc1f    'bc, 'imm16u");
    986           }
    987           break;
    988         case BC1EQZ:
    989           Format(instr, "bc1eqz    'ft, 'imm16u");
    990           break;
    991         case BC1NEZ:
    992           Format(instr, "bc1nez    'ft, 'imm16u");
    993           break;
    994         case W:  // CMP.S instruction.
    995           switch (instr->FunctionValue()) {
    996             case CMP_AF:
    997               Format(instr, "cmp.af.S    'ft, 'fs, 'fd");
    998               break;
    999             case CMP_UN:
   1000               Format(instr, "cmp.un.S    'ft, 'fs, 'fd");
   1001               break;
   1002             case CMP_EQ:
   1003               Format(instr, "cmp.eq.S    'ft, 'fs, 'fd");
   1004               break;
   1005             case CMP_UEQ:
   1006               Format(instr, "cmp.ueq.S   'ft, 'fs, 'fd");
   1007               break;
   1008             case CMP_LT:
   1009               Format(instr, "cmp.lt.S    'ft, 'fs, 'fd");
   1010               break;
   1011             case CMP_ULT:
   1012               Format(instr, "cmp.ult.S   'ft, 'fs, 'fd");
   1013               break;
   1014             case CMP_LE:
   1015               Format(instr, "cmp.le.S    'ft, 'fs, 'fd");
   1016               break;
   1017             case CMP_ULE:
   1018               Format(instr, "cmp.ule.S   'ft, 'fs, 'fd");
   1019               break;
   1020             case CMP_OR:
   1021               Format(instr, "cmp.or.S    'ft, 'fs, 'fd");
   1022               break;
   1023             case CMP_UNE:
   1024               Format(instr, "cmp.une.S   'ft, 'fs, 'fd");
   1025               break;
   1026             case CMP_NE:
   1027               Format(instr, "cmp.ne.S    'ft, 'fs, 'fd");
   1028               break;
   1029             default:
   1030               UNREACHABLE();
   1031           }
   1032           break;
   1033         case L:  // CMP.D instruction.
   1034           switch (instr->FunctionValue()) {
   1035             case CMP_AF:
   1036               Format(instr, "cmp.af.D    'ft, 'fs, 'fd");
   1037               break;
   1038             case CMP_UN:
   1039               Format(instr, "cmp.un.D    'ft, 'fs, 'fd");
   1040               break;
   1041             case CMP_EQ:
   1042               Format(instr, "cmp.eq.D    'ft, 'fs, 'fd");
   1043               break;
   1044             case CMP_UEQ:
   1045               Format(instr, "cmp.ueq.D   'ft, 'fs, 'fd");
   1046               break;
   1047             case CMP_LT:
   1048               Format(instr, "cmp.lt.D    'ft, 'fs, 'fd");
   1049               break;
   1050             case CMP_ULT:
   1051               Format(instr, "cmp.ult.D   'ft, 'fs, 'fd");
   1052               break;
   1053             case CMP_LE:
   1054               Format(instr, "cmp.le.D    'ft, 'fs, 'fd");
   1055               break;
   1056             case CMP_ULE:
   1057               Format(instr, "cmp.ule.D   'ft, 'fs, 'fd");
   1058               break;
   1059             case CMP_OR:
   1060               Format(instr, "cmp.or.D    'ft, 'fs, 'fd");
   1061               break;
   1062             case CMP_UNE:
   1063               Format(instr, "cmp.une.D   'ft, 'fs, 'fd");
   1064               break;
   1065             case CMP_NE:
   1066               Format(instr, "cmp.ne.D    'ft, 'fs, 'fd");
   1067               break;
   1068             default:
   1069               UNREACHABLE();
   1070           }
   1071           break;
   1072         case S:
   1073           switch (instr->FunctionValue()) {
   1074             case SEL:
   1075               Format(instr, "sel.S    'ft, 'fs, 'fd");
   1076               break;
   1077             case SELEQZ_C:
   1078               Format(instr, "seleqz.S 'ft, 'fs, 'fd");
   1079               break;
   1080             case SELNEZ_C:
   1081               Format(instr, "selnez.S 'ft, 'fs, 'fd");
   1082               break;
   1083             case MIN:
   1084               Format(instr, "min.S    'ft, 'fs, 'fd");
   1085               break;
   1086             case MINA:
   1087               Format(instr, "mina.S   'ft, 'fs, 'fd");
   1088               break;
   1089             case MAX:
   1090               Format(instr, "max.S    'ft, 'fs, 'fd");
   1091               break;
   1092             case MAXA:
   1093               Format(instr, "maxa.S   'ft, 'fs, 'fd");
   1094               break;
   1095             default:
   1096               UNREACHABLE();
   1097           }
   1098           break;
   1099         case D:
   1100           switch (instr->FunctionValue()) {
   1101             case SEL:
   1102               Format(instr, "sel.D    'ft, 'fs, 'fd");
   1103               break;
   1104             case SELEQZ_C:
   1105               Format(instr, "seleqz.D 'ft, 'fs, 'fd");
   1106               break;
   1107             case SELNEZ_C:
   1108               Format(instr, "selnez.D 'ft, 'fs, 'fd");
   1109               break;
   1110             case MIN:
   1111               Format(instr, "min.D    'ft, 'fs, 'fd");
   1112               break;
   1113             case MINA:
   1114               Format(instr, "mina.D   'ft, 'fs, 'fd");
   1115               break;
   1116             case MAX:
   1117               Format(instr, "max.D    'ft, 'fs, 'fd");
   1118               break;
   1119             case MAXA:
   1120               Format(instr, "maxa.D   'ft, 'fs, 'fd");
   1121               break;
   1122             default:
   1123               UNREACHABLE();
   1124           }
   1125           break;
   1126         default:
   1127           UNREACHABLE();
   1128       }
   1129 
   1130       break;  // Case COP1.
   1131     // ------------- REGIMM class.
   1132     case REGIMM:
   1133       switch (instr->RtFieldRaw()) {
   1134         case BLTZ:
   1135           Format(instr, "bltz    'rs, 'imm16u");
   1136           break;
   1137         case BLTZAL:
   1138           Format(instr, "bltzal  'rs, 'imm16u");
   1139           break;
   1140         case BGEZ:
   1141           Format(instr, "bgez    'rs, 'imm16u");
   1142           break;
   1143         case BGEZAL:
   1144           Format(instr, "bgezal  'rs, 'imm16u");
   1145           break;
   1146         case BGEZALL:
   1147           Format(instr, "bgezall 'rs, 'imm16u");
   1148           break;
   1149         case DAHI:
   1150           Format(instr, "dahi    'rs, 'imm16u");
   1151           break;
   1152         case DATI:
   1153           Format(instr, "dati    'rs, 'imm16u");
   1154           break;
   1155         default:
   1156           UNREACHABLE();
   1157       }
   1158     break;  // Case REGIMM.
   1159     // ------------- Branch instructions.
   1160     case BEQ:
   1161       Format(instr, "beq     'rs, 'rt, 'imm16u");
   1162       break;
   1163     case BNE:
   1164       Format(instr, "bne     'rs, 'rt, 'imm16u");
   1165       break;
   1166     case BLEZ:
   1167       if ((instr->RtFieldRaw() == 0)
   1168           && (instr->RsFieldRaw() != 0)) {
   1169         Format(instr, "blez    'rs, 'imm16u");
   1170       } else if ((instr->RtFieldRaw() != instr->RsFieldRaw())
   1171           && (instr->RsFieldRaw() != 0) && (instr->RtFieldRaw() != 0)) {
   1172         Format(instr, "bgeuc    'rs, 'rt, 'imm16u");
   1173       } else if ((instr->RtFieldRaw() == instr->RsFieldRaw())
   1174           && (instr->RtFieldRaw() != 0)) {
   1175         Format(instr, "bgezalc  'rs, 'imm16u");
   1176       } else if ((instr->RsFieldRaw() == 0)
   1177           && (instr->RtFieldRaw() != 0)) {
   1178         Format(instr, "blezalc  'rs, 'imm16u");
   1179       } else {
   1180         UNREACHABLE();
   1181       }
   1182       break;
   1183     case BGTZ:
   1184       if ((instr->RtFieldRaw() == 0)
   1185           && (instr->RsFieldRaw() != 0)) {
   1186         Format(instr, "bgtz    'rs, 'imm16u");
   1187       } else if ((instr->RtFieldRaw() != instr->RsFieldRaw())
   1188           && (instr->RsFieldRaw() != 0) && (instr->RtFieldRaw() != 0)) {
   1189         Format(instr, "bltuc   'rs, 'rt, 'imm16u");
   1190       } else if ((instr->RtFieldRaw() == instr->RsFieldRaw())
   1191           && (instr->RtFieldRaw() != 0)) {
   1192         Format(instr, "bltzalc 'rt, 'imm16u");
   1193       } else if ((instr->RsFieldRaw() == 0)
   1194           && (instr->RtFieldRaw() != 0)) {
   1195         Format(instr, "bgtzalc 'rt, 'imm16u");
   1196       } else {
   1197         UNREACHABLE();
   1198       }
   1199       break;
   1200     case BLEZL:
   1201       if ((instr->RtFieldRaw() == instr->RsFieldRaw())
   1202           && (instr->RtFieldRaw() != 0)) {
   1203         Format(instr, "bgezc    'rt, 'imm16u");
   1204       } else if ((instr->RtFieldRaw() != instr->RsFieldRaw())
   1205           && (instr->RsFieldRaw() != 0) && (instr->RtFieldRaw() != 0)) {
   1206         Format(instr, "bgec     'rs, 'rt, 'imm16u");
   1207       } else if ((instr->RsFieldRaw() == 0)
   1208           && (instr->RtFieldRaw() != 0)) {
   1209         Format(instr, "blezc    'rt, 'imm16u");
   1210       } else {
   1211         UNREACHABLE();
   1212       }
   1213       break;
   1214     case BGTZL:
   1215       if ((instr->RtFieldRaw() == instr->RsFieldRaw())
   1216           && (instr->RtFieldRaw() != 0)) {
   1217         Format(instr, "bltzc    'rt, 'imm16u");
   1218       } else if ((instr->RtFieldRaw() != instr->RsFieldRaw())
   1219           && (instr->RsFieldRaw() != 0) && (instr->RtFieldRaw() != 0)) {
   1220         Format(instr, "bltc     'rs, 'rt, 'imm16u");
   1221       } else if ((instr->RsFieldRaw() == 0)
   1222           && (instr->RtFieldRaw() != 0)) {
   1223         Format(instr, "bgtzc    'rt, 'imm16u");
   1224       } else {
   1225         UNREACHABLE();
   1226       }
   1227       break;
   1228     case BEQZC:
   1229       if (instr->RsFieldRaw() != 0) {
   1230         Format(instr, "beqzc   'rs, 'imm21x");
   1231       }
   1232       break;
   1233     case BNEZC:
   1234       if (instr->RsFieldRaw() != 0) {
   1235         Format(instr, "bnezc   'rs, 'imm21x");
   1236       }
   1237       break;
   1238     // ------------- Arithmetic instructions.
   1239     case ADDI:
   1240       if (kArchVariant != kMips64r6) {
   1241         Format(instr, "addi    'rt, 'rs, 'imm16s");
   1242       } else {
   1243         // Check if BOVC or BEQC instruction.
   1244         if (instr->RsFieldRaw() >= instr->RtFieldRaw()) {
   1245           Format(instr, "bovc  'rs, 'rt, 'imm16s");
   1246         } else if (instr->RsFieldRaw() < instr->RtFieldRaw()) {
   1247           Format(instr, "beqc  'rs, 'rt, 'imm16s");
   1248         } else {
   1249           UNREACHABLE();
   1250         }
   1251       }
   1252       break;
   1253     case DADDI:
   1254       if (kArchVariant != kMips64r6) {
   1255         Format(instr, "daddi   'rt, 'rs, 'imm16s");
   1256       } else {
   1257         // Check if BNVC or BNEC instruction.
   1258         if (instr->RsFieldRaw() >= instr->RtFieldRaw()) {
   1259           Format(instr, "bnvc  'rs, 'rt, 'imm16s");
   1260         } else if (instr->RsFieldRaw() < instr->RtFieldRaw()) {
   1261           Format(instr, "bnec  'rs, 'rt, 'imm16s");
   1262         } else {
   1263           UNREACHABLE();
   1264         }
   1265       }
   1266       break;
   1267     case ADDIU:
   1268       Format(instr, "addiu   'rt, 'rs, 'imm16s");
   1269       break;
   1270     case DADDIU:
   1271       Format(instr, "daddiu  'rt, 'rs, 'imm16s");
   1272       break;
   1273     case SLTI:
   1274       Format(instr, "slti    'rt, 'rs, 'imm16s");
   1275       break;
   1276     case SLTIU:
   1277       Format(instr, "sltiu   'rt, 'rs, 'imm16u");
   1278       break;
   1279     case ANDI:
   1280       Format(instr, "andi    'rt, 'rs, 'imm16x");
   1281       break;
   1282     case ORI:
   1283       Format(instr, "ori     'rt, 'rs, 'imm16x");
   1284       break;
   1285     case XORI:
   1286       Format(instr, "xori    'rt, 'rs, 'imm16x");
   1287       break;
   1288     case LUI:
   1289       if (kArchVariant != kMips64r6) {
   1290         Format(instr, "lui     'rt, 'imm16x");
   1291       } else {
   1292         if (instr->RsValue() != 0) {
   1293           Format(instr, "aui     'rt, 'imm16x");
   1294         } else {
   1295           Format(instr, "lui     'rt, 'imm16x");
   1296         }
   1297       }
   1298       break;
   1299     case DAUI:
   1300       Format(instr, "daui    'rt, 'imm16x");
   1301       break;
   1302     // ------------- Memory instructions.
   1303     case LB:
   1304       Format(instr, "lb      'rt, 'imm16s('rs)");
   1305       break;
   1306     case LH:
   1307       Format(instr, "lh      'rt, 'imm16s('rs)");
   1308       break;
   1309     case LWL:
   1310       Format(instr, "lwl     'rt, 'imm16s('rs)");
   1311       break;
   1312     case LDL:
   1313       Format(instr, "ldl     'rt, 'imm16s('rs)");
   1314       break;
   1315     case LW:
   1316       Format(instr, "lw      'rt, 'imm16s('rs)");
   1317       break;
   1318     case LWU:
   1319       Format(instr, "lwu     'rt, 'imm16s('rs)");
   1320       break;
   1321     case LD:
   1322       Format(instr, "ld      'rt, 'imm16s('rs)");
   1323       break;
   1324     case LBU:
   1325       Format(instr, "lbu     'rt, 'imm16s('rs)");
   1326       break;
   1327     case LHU:
   1328       Format(instr, "lhu     'rt, 'imm16s('rs)");
   1329       break;
   1330     case LWR:
   1331       Format(instr, "lwr     'rt, 'imm16s('rs)");
   1332       break;
   1333     case LDR:
   1334       Format(instr, "ldr     'rt, 'imm16s('rs)");
   1335       break;
   1336     case PREF:
   1337       Format(instr, "pref    'rt, 'imm16s('rs)");
   1338       break;
   1339     case SB:
   1340       Format(instr, "sb      'rt, 'imm16s('rs)");
   1341       break;
   1342     case SH:
   1343       Format(instr, "sh      'rt, 'imm16s('rs)");
   1344       break;
   1345     case SWL:
   1346       Format(instr, "swl     'rt, 'imm16s('rs)");
   1347       break;
   1348     case SW:
   1349       Format(instr, "sw      'rt, 'imm16s('rs)");
   1350       break;
   1351     case SD:
   1352       Format(instr, "sd      'rt, 'imm16s('rs)");
   1353       break;
   1354     case SWR:
   1355       Format(instr, "swr     'rt, 'imm16s('rs)");
   1356       break;
   1357     case LWC1:
   1358       Format(instr, "lwc1    'ft, 'imm16s('rs)");
   1359       break;
   1360     case LDC1:
   1361       Format(instr, "ldc1    'ft, 'imm16s('rs)");
   1362       break;
   1363     case SWC1:
   1364       Format(instr, "swc1    'ft, 'imm16s('rs)");
   1365       break;
   1366     case SDC1:
   1367       Format(instr, "sdc1    'ft, 'imm16s('rs)");
   1368       break;
   1369     default:
   1370       printf("a 0x%x \n", instr->OpcodeFieldRaw());
   1371     UNREACHABLE();
   1372       break;
   1373   }
   1374 }
   1375 
   1376 
   1377 void Decoder::DecodeTypeJump(Instruction* instr) {
   1378   switch (instr->OpcodeFieldRaw()) {
   1379     case J:
   1380       Format(instr, "j       'imm26x");
   1381       break;
   1382     case JAL:
   1383       Format(instr, "jal     'imm26x");
   1384       break;
   1385     default:
   1386       UNREACHABLE();
   1387   }
   1388 }
   1389 
   1390 
   1391 // Disassemble the instruction at *instr_ptr into the output buffer.
   1392 // All instructions are one word long, except for the simulator
   1393 // psuedo-instruction stop(msg). For that one special case, we return
   1394 // size larger than one kInstrSize.
   1395 int Decoder::InstructionDecode(byte* instr_ptr) {
   1396   Instruction* instr = Instruction::At(instr_ptr);
   1397   // Print raw instruction bytes.
   1398   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
   1399                               "%08x       ",
   1400                               instr->InstructionBits());
   1401   switch (instr->InstructionType()) {
   1402     case Instruction::kRegisterType: {
   1403       return DecodeTypeRegister(instr);
   1404     }
   1405     case Instruction::kImmediateType: {
   1406       DecodeTypeImmediate(instr);
   1407       break;
   1408     }
   1409     case Instruction::kJumpType: {
   1410       DecodeTypeJump(instr);
   1411       break;
   1412     }
   1413     default: {
   1414       Format(instr, "UNSUPPORTED");
   1415       UNSUPPORTED_MIPS();
   1416     }
   1417   }
   1418   return Instruction::kInstrSize;
   1419 }
   1420 
   1421 
   1422 } }  // namespace v8::internal
   1423 
   1424 
   1425 
   1426 //------------------------------------------------------------------------------
   1427 
   1428 namespace disasm {
   1429 
   1430 const char* NameConverter::NameOfAddress(byte* addr) const {
   1431   v8::internal::SNPrintF(tmp_buffer_, "%p", addr);
   1432   return tmp_buffer_.start();
   1433 }
   1434 
   1435 
   1436 const char* NameConverter::NameOfConstant(byte* addr) const {
   1437   return NameOfAddress(addr);
   1438 }
   1439 
   1440 
   1441 const char* NameConverter::NameOfCPURegister(int reg) const {
   1442   return v8::internal::Registers::Name(reg);
   1443 }
   1444 
   1445 
   1446 const char* NameConverter::NameOfXMMRegister(int reg) const {
   1447   return v8::internal::FPURegisters::Name(reg);
   1448 }
   1449 
   1450 
   1451 const char* NameConverter::NameOfByteCPURegister(int reg) const {
   1452   UNREACHABLE();  // MIPS does not have the concept of a byte register.
   1453   return "nobytereg";
   1454 }
   1455 
   1456 
   1457 const char* NameConverter::NameInCode(byte* addr) const {
   1458   // The default name converter is called for unknown code. So we will not try
   1459   // to access any memory.
   1460   return "";
   1461 }
   1462 
   1463 
   1464 //------------------------------------------------------------------------------
   1465 
   1466 Disassembler::Disassembler(const NameConverter& converter)
   1467     : converter_(converter) {}
   1468 
   1469 
   1470 Disassembler::~Disassembler() {}
   1471 
   1472 
   1473 int Disassembler::InstructionDecode(v8::internal::Vector<char> buffer,
   1474                                     byte* instruction) {
   1475   v8::internal::Decoder d(converter_, buffer);
   1476   return d.InstructionDecode(instruction);
   1477 }
   1478 
   1479 
   1480 // The MIPS assembler does not currently use constant pools.
   1481 int Disassembler::ConstantPoolSizeAt(byte* instruction) {
   1482   return -1;
   1483 }
   1484 
   1485 
   1486 void Disassembler::Disassemble(FILE* f, byte* begin, byte* end) {
   1487   NameConverter converter;
   1488   Disassembler d(converter);
   1489   for (byte* pc = begin; pc < end;) {
   1490     v8::internal::EmbeddedVector<char, 128> buffer;
   1491     buffer[0] = '\0';
   1492     byte* prev_pc = pc;
   1493     pc += d.InstructionDecode(buffer, pc);
   1494     v8::internal::PrintF(f, "%p    %08x      %s\n",
   1495         prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer.start());
   1496   }
   1497 }
   1498 
   1499 
   1500 #undef UNSUPPORTED
   1501 
   1502 }  // namespace disasm
   1503 
   1504 #endif  // V8_TARGET_ARCH_MIPS64
   1505