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 #if V8_TARGET_ARCH_MIPS64
32 
33 #include "src/base/platform/platform.h"
34 #include "src/disasm.h"
35 #include "src/macro-assembler.h"
36 #include "src/mips64/constants-mips64.h"
37 
38 namespace v8 {
39 namespace internal {
40 
41 //------------------------------------------------------------------------------
42 
43 // Decoder decodes and disassembles instructions into an output buffer.
44 // It uses the converter to convert register names and call destinations into
45 // more informative description.
46 class Decoder {
47  public:
Decoder(const disasm::NameConverter & converter,v8::internal::Vector<char> out_buffer)48   Decoder(const disasm::NameConverter& converter,
49           v8::internal::Vector<char> out_buffer)
50     : converter_(converter),
51       out_buffer_(out_buffer),
52       out_buffer_pos_(0) {
53     out_buffer_[out_buffer_pos_] = '\0';
54   }
55 
~Decoder()56   ~Decoder() {}
57 
58   // Writes one disassembled instruction into 'buffer' (0-terminated).
59   // Returns the length of the disassembled machine instruction in bytes.
60   int InstructionDecode(byte* instruction);
61 
62  private:
63   // Bottleneck functions to print into the out_buffer.
64   void PrintChar(const char ch);
65   void Print(const char* str);
66 
67   // Printing of common values.
68   void PrintRegister(int reg);
69   void PrintFPURegister(int freg);
70   void PrintFPUStatusRegister(int freg);
71   void PrintRs(Instruction* instr);
72   void PrintRt(Instruction* instr);
73   void PrintRd(Instruction* instr);
74   void PrintFs(Instruction* instr);
75   void PrintFt(Instruction* instr);
76   void PrintFd(Instruction* instr);
77   void PrintSa(Instruction* instr);
78   void PrintLsaSa(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 PrintPCImm16(Instruction* instr, int delta_pc, int n_bits);
90   void PrintXImm18(Instruction* instr);
91   void PrintSImm18(Instruction* instr);
92   void PrintXImm19(Instruction* instr);
93   void PrintSImm19(Instruction* instr);
94   void PrintXImm21(Instruction* instr);
95   void PrintSImm21(Instruction* instr);
96   void PrintPCImm21(Instruction* instr, int delta_pc, int n_bits);
97   void PrintXImm26(Instruction* instr);
98   void PrintSImm26(Instruction* instr);
99   void PrintPCImm26(Instruction* instr, int delta_pc, int n_bits);
100   void PrintPCImm26(Instruction* instr);
101   void PrintCode(Instruction* instr);   // For break and trap instructions.
102   void PrintFormat(Instruction* instr);  // For floating format postfix.
103   void PrintBp2(Instruction* instr);
104   void PrintBp3(Instruction* instr);
105   // Printing of instruction name.
106   void PrintInstructionName(Instruction* instr);
107 
108   // Handle formatting of instructions and their options.
109   int FormatRegister(Instruction* instr, const char* option);
110   int FormatFPURegister(Instruction* instr, const char* option);
111   int FormatOption(Instruction* instr, const char* option);
112   void Format(Instruction* instr, const char* format);
113   void Unknown(Instruction* instr);
114   int DecodeBreakInstr(Instruction* instr);
115 
116   // Each of these functions decodes one particular instruction type.
117   bool DecodeTypeRegisterRsType(Instruction* instr);
118   void DecodeTypeRegisterSRsType(Instruction* instr);
119   void DecodeTypeRegisterDRsType(Instruction* instr);
120   void DecodeTypeRegisterLRsType(Instruction* instr);
121   void DecodeTypeRegisterWRsType(Instruction* instr);
122   void DecodeTypeRegisterSPECIAL(Instruction* instr);
123   void DecodeTypeRegisterSPECIAL2(Instruction* instr);
124   void DecodeTypeRegisterSPECIAL3(Instruction* instr);
125   void DecodeTypeRegisterCOP1(Instruction* instr);
126   void DecodeTypeRegisterCOP1X(Instruction* instr);
127   int DecodeTypeRegister(Instruction* instr);
128 
129   void DecodeTypeImmediateCOP1(Instruction* instr);
130   void DecodeTypeImmediateREGIMM(Instruction* instr);
131   void DecodeTypeImmediate(Instruction* instr);
132 
133   void DecodeTypeJump(Instruction* instr);
134 
135   const disasm::NameConverter& converter_;
136   v8::internal::Vector<char> out_buffer_;
137   int out_buffer_pos_;
138 
139   DISALLOW_COPY_AND_ASSIGN(Decoder);
140 };
141 
142 
143 // Support for assertions in the Decoder formatting functions.
144 #define STRING_STARTS_WITH(string, compare_string) \
145   (strncmp(string, compare_string, strlen(compare_string)) == 0)
146 
147 
148 // Append the ch to the output buffer.
PrintChar(const char ch)149 void Decoder::PrintChar(const char ch) {
150   out_buffer_[out_buffer_pos_++] = ch;
151 }
152 
153 
154 // Append the str to the output buffer.
Print(const char * str)155 void Decoder::Print(const char* str) {
156   char cur = *str++;
157   while (cur != '\0' && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
158     PrintChar(cur);
159     cur = *str++;
160   }
161   out_buffer_[out_buffer_pos_] = 0;
162 }
163 
164 
165 // Print the register name according to the active name converter.
PrintRegister(int reg)166 void Decoder::PrintRegister(int reg) {
167   Print(converter_.NameOfCPURegister(reg));
168 }
169 
170 
PrintRs(Instruction * instr)171 void Decoder::PrintRs(Instruction* instr) {
172   int reg = instr->RsValue();
173   PrintRegister(reg);
174 }
175 
176 
PrintRt(Instruction * instr)177 void Decoder::PrintRt(Instruction* instr) {
178   int reg = instr->RtValue();
179   PrintRegister(reg);
180 }
181 
182 
PrintRd(Instruction * instr)183 void Decoder::PrintRd(Instruction* instr) {
184   int reg = instr->RdValue();
185   PrintRegister(reg);
186 }
187 
188 
189 // Print the FPUregister name according to the active name converter.
PrintFPURegister(int freg)190 void Decoder::PrintFPURegister(int freg) {
191   Print(converter_.NameOfXMMRegister(freg));
192 }
193 
194 
PrintFPUStatusRegister(int freg)195 void Decoder::PrintFPUStatusRegister(int freg) {
196   switch (freg) {
197     case kFCSRRegister:
198       Print("FCSR");
199       break;
200     default:
201       Print(converter_.NameOfXMMRegister(freg));
202   }
203 }
204 
205 
PrintFs(Instruction * instr)206 void Decoder::PrintFs(Instruction* instr) {
207   int freg = instr->RsValue();
208   PrintFPURegister(freg);
209 }
210 
211 
PrintFt(Instruction * instr)212 void Decoder::PrintFt(Instruction* instr) {
213   int freg = instr->RtValue();
214   PrintFPURegister(freg);
215 }
216 
217 
PrintFd(Instruction * instr)218 void Decoder::PrintFd(Instruction* instr) {
219   int freg = instr->RdValue();
220   PrintFPURegister(freg);
221 }
222 
223 
224 // Print the integer value of the sa field.
PrintSa(Instruction * instr)225 void Decoder::PrintSa(Instruction* instr) {
226   int sa = instr->SaValue();
227   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", sa);
228 }
229 
230 
231 // Print the integer value of the sa field of a lsa instruction.
PrintLsaSa(Instruction * instr)232 void Decoder::PrintLsaSa(Instruction* instr) {
233   int sa = instr->LsaSaValue() + 1;
234   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", sa);
235 }
236 
237 
238 // Print the integer value of the rd field, when it is not used as reg.
PrintSd(Instruction * instr)239 void Decoder::PrintSd(Instruction* instr) {
240   int sd = instr->RdValue();
241   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", sd);
242 }
243 
244 
245 // Print the integer value of the rd field, when used as 'ext' size.
PrintSs1(Instruction * instr)246 void Decoder::PrintSs1(Instruction* instr) {
247   int ss = instr->RdValue();
248   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", ss + 1);
249 }
250 
251 
252 // Print the integer value of the rd field, when used as 'ins' size.
PrintSs2(Instruction * instr)253 void Decoder::PrintSs2(Instruction* instr) {
254   int ss = instr->RdValue();
255   int pos = instr->SaValue();
256   out_buffer_pos_ +=
257       SNPrintF(out_buffer_ + out_buffer_pos_, "%d", ss - pos + 1);
258 }
259 
260 
261 // Print the integer value of the cc field for the bc1t/f instructions.
PrintBc(Instruction * instr)262 void Decoder::PrintBc(Instruction* instr) {
263   int cc = instr->FBccValue();
264   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", cc);
265 }
266 
267 
268 // Print the integer value of the cc field for the FP compare instructions.
PrintCc(Instruction * instr)269 void Decoder::PrintCc(Instruction* instr) {
270   int cc = instr->FCccValue();
271   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "cc(%d)", cc);
272 }
273 
274 
275 // Print 16-bit unsigned immediate value.
PrintUImm16(Instruction * instr)276 void Decoder::PrintUImm16(Instruction* instr) {
277   int32_t imm = instr->Imm16Value();
278   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%u", imm);
279 }
280 
281 
282 // Print 16-bit signed immediate value.
PrintSImm16(Instruction * instr)283 void Decoder::PrintSImm16(Instruction* instr) {
284   int32_t imm =
285       ((instr->Imm16Value()) << (32 - kImm16Bits)) >> (32 - kImm16Bits);
286   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", imm);
287 }
288 
289 
290 // Print 16-bit hexa immediate value.
PrintXImm16(Instruction * instr)291 void Decoder::PrintXImm16(Instruction* instr) {
292   int32_t imm = instr->Imm16Value();
293   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "0x%x", imm);
294 }
295 
296 
297 // Print absoulte address for 16-bit offset or immediate value.
298 // The absolute address is calculated according following expression:
299 //      PC + delta_pc + (offset << n_bits)
PrintPCImm16(Instruction * instr,int delta_pc,int n_bits)300 void Decoder::PrintPCImm16(Instruction* instr, int delta_pc, int n_bits) {
301   int16_t offset = instr->Imm16Value();
302   out_buffer_pos_ +=
303       SNPrintF(out_buffer_ + out_buffer_pos_, "%s",
304                converter_.NameOfAddress(reinterpret_cast<byte*>(instr) +
305                                         delta_pc + (offset << n_bits)));
306 }
307 
308 
309 // Print 18-bit signed immediate value.
PrintSImm18(Instruction * instr)310 void Decoder::PrintSImm18(Instruction* instr) {
311   int32_t imm =
312       ((instr->Imm18Value()) << (32 - kImm18Bits)) >> (32 - kImm18Bits);
313   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", imm);
314 }
315 
316 
317 // Print 18-bit hexa immediate value.
PrintXImm18(Instruction * instr)318 void Decoder::PrintXImm18(Instruction* instr) {
319   int32_t imm = instr->Imm18Value();
320   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "0x%x", imm);
321 }
322 
323 
324 // Print 19-bit hexa immediate value.
PrintXImm19(Instruction * instr)325 void Decoder::PrintXImm19(Instruction* instr) {
326   int32_t imm = instr->Imm19Value();
327   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "0x%x", imm);
328 }
329 
330 
331 // Print 19-bit signed immediate value.
PrintSImm19(Instruction * instr)332 void Decoder::PrintSImm19(Instruction* instr) {
333   int32_t imm19 = instr->Imm19Value();
334   // set sign
335   imm19 <<= (32 - kImm19Bits);
336   imm19 >>= (32 - kImm19Bits);
337   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", imm19);
338 }
339 
340 
341 // Print 21-bit immediate value.
PrintXImm21(Instruction * instr)342 void Decoder::PrintXImm21(Instruction* instr) {
343   uint32_t imm = instr->Imm21Value();
344   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "0x%x", imm);
345 }
346 
347 
348 // Print 21-bit signed immediate value.
PrintSImm21(Instruction * instr)349 void Decoder::PrintSImm21(Instruction* instr) {
350   int32_t imm21 = instr->Imm21Value();
351   // set sign
352   imm21 <<= (32 - kImm21Bits);
353   imm21 >>= (32 - kImm21Bits);
354   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", imm21);
355 }
356 
357 
358 // Print absoulte address for 21-bit offset or immediate value.
359 // The absolute address is calculated according following expression:
360 //      PC + delta_pc + (offset << n_bits)
PrintPCImm21(Instruction * instr,int delta_pc,int n_bits)361 void Decoder::PrintPCImm21(Instruction* instr, int delta_pc, int n_bits) {
362   int32_t imm21 = instr->Imm21Value();
363   // set sign
364   imm21 <<= (32 - kImm21Bits);
365   imm21 >>= (32 - kImm21Bits);
366   out_buffer_pos_ +=
367       SNPrintF(out_buffer_ + out_buffer_pos_, "%s",
368                converter_.NameOfAddress(reinterpret_cast<byte*>(instr) +
369                                         delta_pc + (imm21 << n_bits)));
370 }
371 
372 
373 // Print 26-bit hex immediate value.
PrintXImm26(Instruction * instr)374 void Decoder::PrintXImm26(Instruction* instr) {
375   uint64_t target = static_cast<uint64_t>(instr->Imm26Value())
376                     << kImmFieldShift;
377   target = (reinterpret_cast<uint64_t>(instr) & ~0xfffffff) | target;
378   out_buffer_pos_ +=
379       SNPrintF(out_buffer_ + out_buffer_pos_, "0x%" PRIx64, target);
380 }
381 
382 
383 // Print 26-bit signed immediate value.
PrintSImm26(Instruction * instr)384 void Decoder::PrintSImm26(Instruction* instr) {
385   int32_t imm26 = instr->Imm26Value();
386   // set sign
387   imm26 <<= (32 - kImm26Bits);
388   imm26 >>= (32 - kImm26Bits);
389   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", imm26);
390 }
391 
392 
393 // Print absoulte address for 26-bit offset or immediate value.
394 // The absolute address is calculated according following expression:
395 //      PC + delta_pc + (offset << n_bits)
PrintPCImm26(Instruction * instr,int delta_pc,int n_bits)396 void Decoder::PrintPCImm26(Instruction* instr, int delta_pc, int n_bits) {
397   int32_t imm26 = instr->Imm26Value();
398   // set sign
399   imm26 <<= (32 - kImm26Bits);
400   imm26 >>= (32 - kImm26Bits);
401   out_buffer_pos_ +=
402       SNPrintF(out_buffer_ + out_buffer_pos_, "%s",
403                converter_.NameOfAddress(reinterpret_cast<byte*>(instr) +
404                                         delta_pc + (imm26 << n_bits)));
405 }
406 
407 
408 // Print absoulte address for 26-bit offset or immediate value.
409 // The absolute address is calculated according following expression:
410 //      PC[GPRLEN-1 .. 28] || instr_index26 || 00
PrintPCImm26(Instruction * instr)411 void Decoder::PrintPCImm26(Instruction* instr) {
412   int32_t imm26 = instr->Imm26Value();
413   uint64_t pc_mask = ~0xfffffff;
414   uint64_t pc = ((uint64_t)(instr + 1) & pc_mask) | (imm26 << 2);
415   out_buffer_pos_ +=
416       SNPrintF(out_buffer_ + out_buffer_pos_, "%s",
417                converter_.NameOfAddress((reinterpret_cast<byte*>(pc))));
418 }
419 
420 
PrintBp2(Instruction * instr)421 void Decoder::PrintBp2(Instruction* instr) {
422   int bp2 = instr->Bp2Value();
423   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", bp2);
424 }
425 
426 
PrintBp3(Instruction * instr)427 void Decoder::PrintBp3(Instruction* instr) {
428   int bp3 = instr->Bp3Value();
429   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", bp3);
430 }
431 
432 
433 // Print 26-bit immediate value.
PrintCode(Instruction * instr)434 void Decoder::PrintCode(Instruction* instr) {
435   if (instr->OpcodeFieldRaw() != SPECIAL)
436     return;  // Not a break or trap instruction.
437   switch (instr->FunctionFieldRaw()) {
438     case BREAK: {
439       int32_t code = instr->Bits(25, 6);
440       out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
441                                   "0x%05x (%d)", code, code);
442       break;
443                 }
444     case TGE:
445     case TGEU:
446     case TLT:
447     case TLTU:
448     case TEQ:
449     case TNE: {
450       int32_t code = instr->Bits(15, 6);
451       out_buffer_pos_ +=
452           SNPrintF(out_buffer_ + out_buffer_pos_, "0x%03x", code);
453       break;
454     }
455     default:  // Not a break or trap instruction.
456     break;
457   }
458 }
459 
460 
PrintFormat(Instruction * instr)461 void Decoder::PrintFormat(Instruction* instr) {
462   char formatLetter = ' ';
463   switch (instr->RsFieldRaw()) {
464     case S:
465       formatLetter = 's';
466       break;
467     case D:
468       formatLetter = 'd';
469       break;
470     case W:
471       formatLetter = 'w';
472       break;
473     case L:
474       formatLetter = 'l';
475       break;
476     default:
477       UNREACHABLE();
478       break;
479   }
480   PrintChar(formatLetter);
481 }
482 
483 
484 // Printing of instruction name.
PrintInstructionName(Instruction * instr)485 void Decoder::PrintInstructionName(Instruction* instr) {
486 }
487 
488 
489 // Handle all register based formatting in this function to reduce the
490 // complexity of FormatOption.
FormatRegister(Instruction * instr,const char * format)491 int Decoder::FormatRegister(Instruction* instr, const char* format) {
492   DCHECK(format[0] == 'r');
493   if (format[1] == 's') {  // 'rs: Rs register.
494     int reg = instr->RsValue();
495     PrintRegister(reg);
496     return 2;
497   } else if (format[1] == 't') {  // 'rt: rt register.
498     int reg = instr->RtValue();
499     PrintRegister(reg);
500     return 2;
501   } else if (format[1] == 'd') {  // 'rd: rd register.
502     int reg = instr->RdValue();
503     PrintRegister(reg);
504     return 2;
505   }
506   UNREACHABLE();
507   return -1;
508 }
509 
510 
511 // Handle all FPUregister based formatting in this function to reduce the
512 // complexity of FormatOption.
FormatFPURegister(Instruction * instr,const char * format)513 int Decoder::FormatFPURegister(Instruction* instr, const char* format) {
514   DCHECK(format[0] == 'f');
515   if ((CTC1 == instr->RsFieldRaw()) || (CFC1 == instr->RsFieldRaw())) {
516     if (format[1] == 's') {  // 'fs: fs register.
517       int reg = instr->FsValue();
518       PrintFPUStatusRegister(reg);
519       return 2;
520     } else if (format[1] == 't') {  // 'ft: ft register.
521       int reg = instr->FtValue();
522       PrintFPUStatusRegister(reg);
523       return 2;
524     } else if (format[1] == 'd') {  // 'fd: fd register.
525       int reg = instr->FdValue();
526       PrintFPUStatusRegister(reg);
527       return 2;
528     } else if (format[1] == 'r') {  // 'fr: fr register.
529       int reg = instr->FrValue();
530       PrintFPUStatusRegister(reg);
531       return 2;
532     }
533   } else {
534     if (format[1] == 's') {  // 'fs: fs register.
535       int reg = instr->FsValue();
536       PrintFPURegister(reg);
537       return 2;
538     } else if (format[1] == 't') {  // 'ft: ft register.
539       int reg = instr->FtValue();
540       PrintFPURegister(reg);
541       return 2;
542     } else if (format[1] == 'd') {  // 'fd: fd register.
543       int reg = instr->FdValue();
544       PrintFPURegister(reg);
545       return 2;
546     } else if (format[1] == 'r') {  // 'fr: fr register.
547       int reg = instr->FrValue();
548       PrintFPURegister(reg);
549       return 2;
550     }
551   }
552   UNREACHABLE();
553   return -1;
554 }
555 
556 
557 // FormatOption takes a formatting string and interprets it based on
558 // the current instructions. The format string points to the first
559 // character of the option string (the option escape has already been
560 // consumed by the caller.)  FormatOption returns the number of
561 // characters that were consumed from the formatting string.
FormatOption(Instruction * instr,const char * format)562 int Decoder::FormatOption(Instruction* instr, const char* format) {
563   switch (format[0]) {
564     case 'c': {   // 'code for break or trap instructions.
565       DCHECK(STRING_STARTS_WITH(format, "code"));
566       PrintCode(instr);
567       return 4;
568     }
569     case 'i': {   // 'imm16u or 'imm26.
570       if (format[3] == '1') {
571         if (format[4] == '6') {
572           DCHECK(STRING_STARTS_WITH(format, "imm16"));
573           switch (format[5]) {
574             case 's':
575               DCHECK(STRING_STARTS_WITH(format, "imm16s"));
576               PrintSImm16(instr);
577               break;
578             case 'u':
579               DCHECK(STRING_STARTS_WITH(format, "imm16u"));
580               PrintSImm16(instr);
581               break;
582             case 'x':
583               DCHECK(STRING_STARTS_WITH(format, "imm16x"));
584               PrintXImm16(instr);
585               break;
586             case 'p': {  // The PC relative address.
587               DCHECK(STRING_STARTS_WITH(format, "imm16p"));
588               int delta_pc = 0;
589               int n_bits = 0;
590               switch (format[6]) {
591                 case '4': {
592                   DCHECK(STRING_STARTS_WITH(format, "imm16p4"));
593                   delta_pc = 4;
594                   switch (format[8]) {
595                     case '2':
596                       DCHECK(STRING_STARTS_WITH(format, "imm16p4s2"));
597                       n_bits = 2;
598                       PrintPCImm16(instr, delta_pc, n_bits);
599                       return 9;
600                   }
601                 }
602               }
603             }
604           }
605           return 6;
606         } else if (format[4] == '8') {
607           DCHECK(STRING_STARTS_WITH(format, "imm18"));
608           switch (format[5]) {
609             case 's':
610               DCHECK(STRING_STARTS_WITH(format, "imm18s"));
611               PrintSImm18(instr);
612               break;
613             case 'x':
614               DCHECK(STRING_STARTS_WITH(format, "imm18x"));
615               PrintXImm18(instr);
616               break;
617           }
618           return 6;
619         } else if (format[4] == '9') {
620           DCHECK(STRING_STARTS_WITH(format, "imm19"));
621           switch (format[5]) {
622             case 's':
623               DCHECK(STRING_STARTS_WITH(format, "imm19s"));
624               PrintSImm19(instr);
625               break;
626             case 'x':
627               DCHECK(STRING_STARTS_WITH(format, "imm19x"));
628               PrintXImm19(instr);
629               break;
630           }
631           return 6;
632         }
633       } else if (format[3] == '2' && format[4] == '1') {
634         DCHECK(STRING_STARTS_WITH(format, "imm21"));
635         switch (format[5]) {
636           case 's':
637             DCHECK(STRING_STARTS_WITH(format, "imm21s"));
638             PrintSImm21(instr);
639             break;
640           case 'x':
641             DCHECK(STRING_STARTS_WITH(format, "imm21x"));
642             PrintXImm21(instr);
643             break;
644           case 'p': {  // The PC relative address.
645             DCHECK(STRING_STARTS_WITH(format, "imm21p"));
646             int delta_pc = 0;
647             int n_bits = 0;
648             switch (format[6]) {
649               case '4': {
650                 DCHECK(STRING_STARTS_WITH(format, "imm21p4"));
651                 delta_pc = 4;
652                 switch (format[8]) {
653                   case '2':
654                     DCHECK(STRING_STARTS_WITH(format, "imm21p4s2"));
655                     n_bits = 2;
656                     PrintPCImm21(instr, delta_pc, n_bits);
657                     return 9;
658                 }
659               }
660             }
661           }
662         }
663         return 6;
664       } else if (format[3] == '2' && format[4] == '6') {
665         DCHECK(STRING_STARTS_WITH(format, "imm26"));
666         switch (format[5]) {
667           case 's':
668             DCHECK(STRING_STARTS_WITH(format, "imm26s"));
669             PrintSImm26(instr);
670             break;
671           case 'x':
672             DCHECK(STRING_STARTS_WITH(format, "imm26x"));
673             PrintXImm26(instr);
674             break;
675           case 'p': {  // The PC relative address.
676             DCHECK(STRING_STARTS_WITH(format, "imm26p"));
677             int delta_pc = 0;
678             int n_bits = 0;
679             switch (format[6]) {
680               case '4': {
681                 DCHECK(STRING_STARTS_WITH(format, "imm26p4"));
682                 delta_pc = 4;
683                 switch (format[8]) {
684                   case '2':
685                     DCHECK(STRING_STARTS_WITH(format, "imm26p4s2"));
686                     n_bits = 2;
687                     PrintPCImm26(instr, delta_pc, n_bits);
688                     return 9;
689                 }
690               }
691             }
692           }
693           case 'j': {  // Absolute address for jump instructions.
694             DCHECK(STRING_STARTS_WITH(format, "imm26j"));
695             PrintPCImm26(instr);
696             break;
697           }
698         }
699         return 6;
700       }
701     }
702     case 'r': {   // 'r: registers.
703       return FormatRegister(instr, format);
704     }
705     case 'f': {   // 'f: FPUregisters.
706       return FormatFPURegister(instr, format);
707     }
708     case 's': {   // 'sa.
709       switch (format[1]) {
710         case 'a':
711           if (format[2] == '2') {
712             DCHECK(STRING_STARTS_WITH(format, "sa2"));  // 'sa2
713             PrintLsaSa(instr);
714             return 3;
715           } else {
716             DCHECK(STRING_STARTS_WITH(format, "sa"));
717             PrintSa(instr);
718             return 2;
719           }
720           break;
721         case 'd': {
722           DCHECK(STRING_STARTS_WITH(format, "sd"));
723           PrintSd(instr);
724           return 2;
725         }
726         case 's': {
727           if (format[2] == '1') {
728               DCHECK(STRING_STARTS_WITH(format, "ss1"));  /* ext size */
729               PrintSs1(instr);
730               return 3;
731           } else {
732               DCHECK(STRING_STARTS_WITH(format, "ss2"));  /* ins size */
733               PrintSs2(instr);
734               return 3;
735           }
736         }
737       }
738     }
739     case 'b': {
740       switch (format[1]) {
741         case 'c': {  // 'bc - Special for bc1 cc field.
742           DCHECK(STRING_STARTS_WITH(format, "bc"));
743           PrintBc(instr);
744           return 2;
745         }
746         case 'p': {
747           switch (format[2]) {
748             case '2': {  // 'bp2
749               DCHECK(STRING_STARTS_WITH(format, "bp2"));
750               PrintBp2(instr);
751               return 3;
752             }
753             case '3': {  // 'bp3
754               DCHECK(STRING_STARTS_WITH(format, "bp3"));
755               PrintBp3(instr);
756               return 3;
757             }
758           }
759         }
760       }
761     }
762     case 'C': {   // 'Cc - Special for c.xx.d cc field.
763       DCHECK(STRING_STARTS_WITH(format, "Cc"));
764       PrintCc(instr);
765       return 2;
766     }
767     case 't':
768       PrintFormat(instr);
769       return 1;
770   }
771   UNREACHABLE();
772   return -1;
773 }
774 
775 
776 // Format takes a formatting string for a whole instruction and prints it into
777 // the output buffer. All escaped options are handed to FormatOption to be
778 // parsed further.
Format(Instruction * instr,const char * format)779 void Decoder::Format(Instruction* instr, const char* format) {
780   char cur = *format++;
781   while ((cur != 0) && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
782     if (cur == '\'') {  // Single quote is used as the formatting escape.
783       format += FormatOption(instr, format);
784     } else {
785       out_buffer_[out_buffer_pos_++] = cur;
786     }
787     cur = *format++;
788   }
789   out_buffer_[out_buffer_pos_]  = '\0';
790 }
791 
792 
793 // For currently unimplemented decodings the disassembler calls Unknown(instr)
794 // which will just print "unknown" of the instruction bits.
Unknown(Instruction * instr)795 void Decoder::Unknown(Instruction* instr) {
796   Format(instr, "unknown");
797 }
798 
799 
DecodeBreakInstr(Instruction * instr)800 int Decoder::DecodeBreakInstr(Instruction* instr) {
801   // This is already known to be BREAK instr, just extract the code.
802   if (instr->Bits(25, 6) == static_cast<int>(kMaxStopCode)) {
803     // This is stop(msg).
804     Format(instr, "break, code: 'code");
805     out_buffer_pos_ += SNPrintF(
806         out_buffer_ + out_buffer_pos_, "\n%p       %08" PRIx64,
807         static_cast<void*>(
808             reinterpret_cast<int32_t*>(instr + Instruction::kInstrSize)),
809         reinterpret_cast<uint64_t>(
810             *reinterpret_cast<char**>(instr + Instruction::kInstrSize)));
811     // Size 3: the break_ instr, plus embedded 64-bit char pointer.
812     return 3 * Instruction::kInstrSize;
813   } else {
814     Format(instr, "break, code: 'code");
815     return Instruction::kInstrSize;
816   }
817 }
818 
819 
DecodeTypeRegisterRsType(Instruction * instr)820 bool Decoder::DecodeTypeRegisterRsType(Instruction* instr) {
821   switch (instr->FunctionFieldRaw()) {
822     case RINT:
823       Format(instr, "rint.'t    'fd, 'fs");
824       break;
825     case SEL:
826       Format(instr, "sel.'t      'fd, 'fs, 'ft");
827       break;
828     case SELEQZ_C:
829       Format(instr, "seleqz.'t    'fd, 'fs, 'ft");
830       break;
831     case SELNEZ_C:
832       Format(instr, "selnez.'t    'fd, 'fs, 'ft");
833       break;
834     case MOVZ_C:
835       Format(instr, "movz.'t    'fd, 'fs, 'rt");
836       break;
837     case MOVN_C:
838       Format(instr, "movn.'t    'fd, 'fs, 'rt");
839       break;
840     case MOVF:
841       if (instr->Bit(16)) {
842         Format(instr, "movt.'t    'fd, 'fs, 'Cc");
843       } else {
844         Format(instr, "movf.'t    'fd, 'fs, 'Cc");
845       }
846       break;
847     case MIN:
848       Format(instr, "min.'t    'fd, 'fs, 'ft");
849       break;
850     case MAX:
851       Format(instr, "max.'t    'fd, 'fs, 'ft");
852       break;
853     case MINA:
854       Format(instr, "mina.'t   'fd, 'fs, 'ft");
855       break;
856     case MAXA:
857       Format(instr, "maxa.'t   'fd, 'fs, 'ft");
858       break;
859     case ADD_D:
860       Format(instr, "add.'t   'fd, 'fs, 'ft");
861       break;
862     case SUB_D:
863       Format(instr, "sub.'t   'fd, 'fs, 'ft");
864       break;
865     case MUL_D:
866       Format(instr, "mul.'t   'fd, 'fs, 'ft");
867       break;
868     case DIV_D:
869       Format(instr, "div.'t   'fd, 'fs, 'ft");
870       break;
871     case ABS_D:
872       Format(instr, "abs.'t   'fd, 'fs");
873       break;
874     case MOV_D:
875       Format(instr, "mov.'t   'fd, 'fs");
876       break;
877     case NEG_D:
878       Format(instr, "neg.'t   'fd, 'fs");
879       break;
880     case SQRT_D:
881       Format(instr, "sqrt.'t  'fd, 'fs");
882       break;
883     case RECIP_D:
884       Format(instr, "recip.'t  'fd, 'fs");
885       break;
886     case RSQRT_D:
887       Format(instr, "rsqrt.'t  'fd, 'fs");
888       break;
889     case CVT_W_D:
890       Format(instr, "cvt.w.'t 'fd, 'fs");
891       break;
892     case CVT_L_D:
893       Format(instr, "cvt.l.'t 'fd, 'fs");
894       break;
895     case TRUNC_W_D:
896       Format(instr, "trunc.w.'t 'fd, 'fs");
897       break;
898     case TRUNC_L_D:
899       Format(instr, "trunc.l.'t 'fd, 'fs");
900       break;
901     case ROUND_W_D:
902       Format(instr, "round.w.'t 'fd, 'fs");
903       break;
904     case ROUND_L_D:
905       Format(instr, "round.l.'t 'fd, 'fs");
906       break;
907     case FLOOR_W_D:
908       Format(instr, "floor.w.'t 'fd, 'fs");
909       break;
910     case FLOOR_L_D:
911       Format(instr, "floor.l.'t 'fd, 'fs");
912       break;
913     case CEIL_W_D:
914       Format(instr, "ceil.w.'t 'fd, 'fs");
915       break;
916     case CEIL_L_D:
917       Format(instr, "ceil.l.'t 'fd, 'fs");
918       break;
919     case CLASS_D:
920       Format(instr, "class.'t 'fd, 'fs");
921       break;
922     case CVT_S_D:
923       Format(instr, "cvt.s.'t 'fd, 'fs");
924       break;
925     case C_F_D:
926       Format(instr, "c.f.'t   'fs, 'ft, 'Cc");
927       break;
928     case C_UN_D:
929       Format(instr, "c.un.'t  'fs, 'ft, 'Cc");
930       break;
931     case C_EQ_D:
932       Format(instr, "c.eq.'t  'fs, 'ft, 'Cc");
933       break;
934     case C_UEQ_D:
935       Format(instr, "c.ueq.'t 'fs, 'ft, 'Cc");
936       break;
937     case C_OLT_D:
938       Format(instr, "c.olt.'t 'fs, 'ft, 'Cc");
939       break;
940     case C_ULT_D:
941       Format(instr, "c.ult.'t 'fs, 'ft, 'Cc");
942       break;
943     case C_OLE_D:
944       Format(instr, "c.ole.'t 'fs, 'ft, 'Cc");
945       break;
946     case C_ULE_D:
947       Format(instr, "c.ule.'t 'fs, 'ft, 'Cc");
948       break;
949     default:
950       return false;
951   }
952   return true;
953 }
954 
955 
DecodeTypeRegisterSRsType(Instruction * instr)956 void Decoder::DecodeTypeRegisterSRsType(Instruction* instr) {
957   if (!DecodeTypeRegisterRsType(instr)) {
958     switch (instr->FunctionFieldRaw()) {
959       case CVT_D_S:
960         Format(instr, "cvt.d.'t 'fd, 'fs");
961         break;
962       case MADDF_S:
963         Format(instr, "maddf.s  'fd, 'fs, 'ft");
964         break;
965       case MSUBF_S:
966         Format(instr, "msubf.s  'fd, 'fs, 'ft");
967         break;
968       default:
969         Format(instr, "unknown.cop1.'t");
970         break;
971     }
972   }
973 }
974 
975 
DecodeTypeRegisterDRsType(Instruction * instr)976 void Decoder::DecodeTypeRegisterDRsType(Instruction* instr) {
977   if (!DecodeTypeRegisterRsType(instr)) {
978     switch (instr->FunctionFieldRaw()) {
979       case MADDF_D:
980         Format(instr, "maddf.d  'fd, 'fs, 'ft");
981         break;
982       case MSUBF_D:
983         Format(instr, "msubf.d  'fd, 'fs, 'ft");
984         break;
985       default:
986         Format(instr, "unknown.cop1.'t");
987         break;
988     }
989   }
990 }
991 
992 
DecodeTypeRegisterLRsType(Instruction * instr)993 void Decoder::DecodeTypeRegisterLRsType(Instruction* instr) {
994   switch (instr->FunctionFieldRaw()) {
995     case CVT_D_L:
996       Format(instr, "cvt.d.l 'fd, 'fs");
997       break;
998     case CVT_S_L:
999       Format(instr, "cvt.s.l 'fd, 'fs");
1000       break;
1001     case CMP_AF:
1002       Format(instr, "cmp.af.d  'fd,  'fs, 'ft");
1003       break;
1004     case CMP_UN:
1005       Format(instr, "cmp.un.d  'fd,  'fs, 'ft");
1006       break;
1007     case CMP_EQ:
1008       Format(instr, "cmp.eq.d  'fd,  'fs, 'ft");
1009       break;
1010     case CMP_UEQ:
1011       Format(instr, "cmp.ueq.d  'fd,  'fs, 'ft");
1012       break;
1013     case CMP_LT:
1014       Format(instr, "cmp.lt.d  'fd,  'fs, 'ft");
1015       break;
1016     case CMP_ULT:
1017       Format(instr, "cmp.ult.d  'fd,  'fs, 'ft");
1018       break;
1019     case CMP_LE:
1020       Format(instr, "cmp.le.d  'fd,  'fs, 'ft");
1021       break;
1022     case CMP_ULE:
1023       Format(instr, "cmp.ule.d  'fd,  'fs, 'ft");
1024       break;
1025     case CMP_OR:
1026       Format(instr, "cmp.or.d  'fd,  'fs, 'ft");
1027       break;
1028     case CMP_UNE:
1029       Format(instr, "cmp.une.d  'fd,  'fs, 'ft");
1030       break;
1031     case CMP_NE:
1032       Format(instr, "cmp.ne.d  'fd,  'fs, 'ft");
1033       break;
1034     default:
1035       UNREACHABLE();
1036   }
1037 }
1038 
1039 
DecodeTypeRegisterWRsType(Instruction * instr)1040 void Decoder::DecodeTypeRegisterWRsType(Instruction* instr) {
1041   switch (instr->FunctionValue()) {
1042     case CVT_S_W:  // Convert word to float (single).
1043       Format(instr, "cvt.s.w 'fd, 'fs");
1044       break;
1045     case CVT_D_W:  // Convert word to double.
1046       Format(instr, "cvt.d.w 'fd, 'fs");
1047       break;
1048     case CMP_AF:
1049       Format(instr, "cmp.af.s    'fd, 'fs, 'ft");
1050       break;
1051     case CMP_UN:
1052       Format(instr, "cmp.un.s    'fd, 'fs, 'ft");
1053       break;
1054     case CMP_EQ:
1055       Format(instr, "cmp.eq.s    'fd, 'fs, 'ft");
1056       break;
1057     case CMP_UEQ:
1058       Format(instr, "cmp.ueq.s   'fd, 'fs, 'ft");
1059       break;
1060     case CMP_LT:
1061       Format(instr, "cmp.lt.s    'fd, 'fs, 'ft");
1062       break;
1063     case CMP_ULT:
1064       Format(instr, "cmp.ult.s   'fd, 'fs, 'ft");
1065       break;
1066     case CMP_LE:
1067       Format(instr, "cmp.le.s    'fd, 'fs, 'ft");
1068       break;
1069     case CMP_ULE:
1070       Format(instr, "cmp.ule.s   'fd, 'fs, 'ft");
1071       break;
1072     case CMP_OR:
1073       Format(instr, "cmp.or.s    'fd, 'fs, 'ft");
1074       break;
1075     case CMP_UNE:
1076       Format(instr, "cmp.une.s   'fd, 'fs, 'ft");
1077       break;
1078     case CMP_NE:
1079       Format(instr, "cmp.ne.s    'fd, 'fs, 'ft");
1080       break;
1081     default:
1082       UNREACHABLE();
1083   }
1084 }
1085 
1086 
DecodeTypeRegisterCOP1(Instruction * instr)1087 void Decoder::DecodeTypeRegisterCOP1(Instruction* instr) {
1088   switch (instr->RsFieldRaw()) {
1089     case MFC1:
1090       Format(instr, "mfc1    'rt, 'fs");
1091       break;
1092     case DMFC1:
1093       Format(instr, "dmfc1    'rt, 'fs");
1094       break;
1095     case MFHC1:
1096       Format(instr, "mfhc1   'rt, 'fs");
1097       break;
1098     case MTC1:
1099       Format(instr, "mtc1    'rt, 'fs");
1100       break;
1101     case DMTC1:
1102       Format(instr, "dmtc1    'rt, 'fs");
1103       break;
1104     // These are called "fs" too, although they are not FPU registers.
1105     case CTC1:
1106       Format(instr, "ctc1    'rt, 'fs");
1107       break;
1108     case CFC1:
1109       Format(instr, "cfc1    'rt, 'fs");
1110       break;
1111     case MTHC1:
1112       Format(instr, "mthc1   'rt, 'fs");
1113       break;
1114     case S:
1115       DecodeTypeRegisterSRsType(instr);
1116       break;
1117     case D:
1118       DecodeTypeRegisterDRsType(instr);
1119       break;
1120     case W:
1121       DecodeTypeRegisterWRsType(instr);
1122       break;
1123     case L:
1124       DecodeTypeRegisterLRsType(instr);
1125       break;
1126     default:
1127       UNREACHABLE();
1128   }
1129 }
1130 
1131 
DecodeTypeRegisterCOP1X(Instruction * instr)1132 void Decoder::DecodeTypeRegisterCOP1X(Instruction* instr) {
1133   switch (instr->FunctionFieldRaw()) {
1134     case MADD_S:
1135       Format(instr, "madd.s  'fd, 'fr, 'fs, 'ft");
1136       break;
1137     case MADD_D:
1138       Format(instr, "madd.d  'fd, 'fr, 'fs, 'ft");
1139       break;
1140     case MSUB_S:
1141       Format(instr, "msub.s  'fd, 'fr, 'fs, 'ft");
1142       break;
1143     case MSUB_D:
1144       Format(instr, "msub.d  'fd, 'fr, 'fs, 'ft");
1145       break;
1146     default:
1147       UNREACHABLE();
1148   }
1149 }
1150 
1151 
DecodeTypeRegisterSPECIAL(Instruction * instr)1152 void Decoder::DecodeTypeRegisterSPECIAL(Instruction* instr) {
1153   switch (instr->FunctionFieldRaw()) {
1154     case JR:
1155       Format(instr, "jr      'rs");
1156       break;
1157     case JALR:
1158       Format(instr, "jalr    'rs, 'rd");
1159       break;
1160     case SLL:
1161       if (0x0 == static_cast<int>(instr->InstructionBits()))
1162         Format(instr, "nop");
1163       else
1164         Format(instr, "sll     'rd, 'rt, 'sa");
1165       break;
1166     case DSLL:
1167       Format(instr, "dsll    'rd, 'rt, 'sa");
1168       break;
1169     case D_MUL_MUH:  // Equals to DMUL.
1170       if (kArchVariant != kMips64r6) {
1171         Format(instr, "dmult   'rs, 'rt");
1172       } else {
1173         if (instr->SaValue() == MUL_OP) {
1174           Format(instr, "dmul   'rd, 'rs, 'rt");
1175         } else {
1176           Format(instr, "dmuh   'rd, 'rs, 'rt");
1177         }
1178       }
1179       break;
1180     case DSLL32:
1181       Format(instr, "dsll32  'rd, 'rt, 'sa");
1182       break;
1183     case SRL:
1184       if (instr->RsValue() == 0) {
1185         Format(instr, "srl     'rd, 'rt, 'sa");
1186       } else {
1187         Format(instr, "rotr    'rd, 'rt, 'sa");
1188       }
1189       break;
1190     case DSRL:
1191       if (instr->RsValue() == 0) {
1192         Format(instr, "dsrl    'rd, 'rt, 'sa");
1193       } else {
1194         Format(instr, "drotr   'rd, 'rt, 'sa");
1195       }
1196       break;
1197     case DSRL32:
1198       if (instr->RsValue() == 0) {
1199         Format(instr, "dsrl32  'rd, 'rt, 'sa");
1200       } else {
1201         Format(instr, "drotr32 'rd, 'rt, 'sa");
1202       }
1203       break;
1204     case SRA:
1205       Format(instr, "sra     'rd, 'rt, 'sa");
1206       break;
1207     case DSRA:
1208       Format(instr, "dsra    'rd, 'rt, 'sa");
1209       break;
1210     case DSRA32:
1211       Format(instr, "dsra32  'rd, 'rt, 'sa");
1212       break;
1213     case SLLV:
1214       Format(instr, "sllv    'rd, 'rt, 'rs");
1215       break;
1216     case DSLLV:
1217       Format(instr, "dsllv   'rd, 'rt, 'rs");
1218       break;
1219     case SRLV:
1220       if (instr->SaValue() == 0) {
1221         Format(instr, "srlv    'rd, 'rt, 'rs");
1222       } else {
1223         Format(instr, "rotrv   'rd, 'rt, 'rs");
1224       }
1225       break;
1226     case DSRLV:
1227       if (instr->SaValue() == 0) {
1228         Format(instr, "dsrlv   'rd, 'rt, 'rs");
1229       } else {
1230         Format(instr, "drotrv  'rd, 'rt, 'rs");
1231       }
1232       break;
1233     case SRAV:
1234       Format(instr, "srav    'rd, 'rt, 'rs");
1235       break;
1236     case DSRAV:
1237       Format(instr, "dsrav   'rd, 'rt, 'rs");
1238       break;
1239     case LSA:
1240       Format(instr, "lsa     'rd, 'rt, 'rs, 'sa2");
1241       break;
1242     case DLSA:
1243       Format(instr, "dlsa    'rd, 'rt, 'rs, 'sa2");
1244       break;
1245     case MFHI:
1246       if (instr->Bits(25, 16) == 0) {
1247         Format(instr, "mfhi    'rd");
1248       } else {
1249         if ((instr->FunctionFieldRaw() == CLZ_R6) && (instr->FdValue() == 1)) {
1250           Format(instr, "clz     'rd, 'rs");
1251         } else if ((instr->FunctionFieldRaw() == CLO_R6) &&
1252                    (instr->FdValue() == 1)) {
1253           Format(instr, "clo     'rd, 'rs");
1254         }
1255       }
1256       break;
1257     case MFLO:
1258       if (instr->Bits(25, 16) == 0) {
1259         Format(instr, "mflo    'rd");
1260       } else {
1261         if ((instr->FunctionFieldRaw() == DCLZ_R6) && (instr->FdValue() == 1)) {
1262           Format(instr, "dclz    'rd, 'rs");
1263         } else if ((instr->FunctionFieldRaw() == DCLO_R6) &&
1264                    (instr->FdValue() == 1)) {
1265           Format(instr, "dclo     'rd, 'rs");
1266         }
1267       }
1268       break;
1269     case D_MUL_MUH_U:  // Equals to DMULTU.
1270       if (kArchVariant != kMips64r6) {
1271         Format(instr, "dmultu  'rs, 'rt");
1272       } else {
1273         if (instr->SaValue() == MUL_OP) {
1274           Format(instr, "dmulu  'rd, 'rs, 'rt");
1275         } else {
1276           Format(instr, "dmuhu  'rd, 'rs, 'rt");
1277         }
1278       }
1279       break;
1280     case MULT:  // @Mips64r6 == MUL_MUH.
1281       if (kArchVariant != kMips64r6) {
1282         Format(instr, "mult    'rs, 'rt");
1283       } else {
1284         if (instr->SaValue() == MUL_OP) {
1285           Format(instr, "mul    'rd, 'rs, 'rt");
1286         } else {
1287           Format(instr, "muh    'rd, 'rs, 'rt");
1288         }
1289       }
1290       break;
1291     case MULTU:  // @Mips64r6 == MUL_MUH_U.
1292       if (kArchVariant != kMips64r6) {
1293         Format(instr, "multu   'rs, 'rt");
1294       } else {
1295         if (instr->SaValue() == MUL_OP) {
1296           Format(instr, "mulu   'rd, 'rs, 'rt");
1297         } else {
1298           Format(instr, "muhu   'rd, 'rs, 'rt");
1299         }
1300       }
1301 
1302       break;
1303     case DIV:  // @Mips64r6 == DIV_MOD.
1304       if (kArchVariant != kMips64r6) {
1305         Format(instr, "div     'rs, 'rt");
1306       } else {
1307         if (instr->SaValue() == DIV_OP) {
1308           Format(instr, "div    'rd, 'rs, 'rt");
1309         } else {
1310           Format(instr, "mod    'rd, 'rs, 'rt");
1311         }
1312       }
1313       break;
1314     case DDIV:  // @Mips64r6 == D_DIV_MOD.
1315       if (kArchVariant != kMips64r6) {
1316         Format(instr, "ddiv    'rs, 'rt");
1317       } else {
1318         if (instr->SaValue() == DIV_OP) {
1319           Format(instr, "ddiv   'rd, 'rs, 'rt");
1320         } else {
1321           Format(instr, "dmod   'rd, 'rs, 'rt");
1322         }
1323       }
1324       break;
1325     case DIVU:  // @Mips64r6 == DIV_MOD_U.
1326       if (kArchVariant != kMips64r6) {
1327         Format(instr, "divu    'rs, 'rt");
1328       } else {
1329         if (instr->SaValue() == DIV_OP) {
1330           Format(instr, "divu   'rd, 'rs, 'rt");
1331         } else {
1332           Format(instr, "modu   'rd, 'rs, 'rt");
1333         }
1334       }
1335       break;
1336     case DDIVU:  // @Mips64r6 == D_DIV_MOD_U.
1337       if (kArchVariant != kMips64r6) {
1338         Format(instr, "ddivu   'rs, 'rt");
1339       } else {
1340         if (instr->SaValue() == DIV_OP) {
1341           Format(instr, "ddivu  'rd, 'rs, 'rt");
1342         } else {
1343           Format(instr, "dmodu  'rd, 'rs, 'rt");
1344         }
1345       }
1346       break;
1347     case ADD:
1348       Format(instr, "add     'rd, 'rs, 'rt");
1349       break;
1350     case DADD:
1351       Format(instr, "dadd    'rd, 'rs, 'rt");
1352       break;
1353     case ADDU:
1354       Format(instr, "addu    'rd, 'rs, 'rt");
1355       break;
1356     case DADDU:
1357       Format(instr, "daddu   'rd, 'rs, 'rt");
1358       break;
1359     case SUB:
1360       Format(instr, "sub     'rd, 'rs, 'rt");
1361       break;
1362     case DSUB:
1363       Format(instr, "dsub    'rd, 'rs, 'rt");
1364       break;
1365     case SUBU:
1366       Format(instr, "subu    'rd, 'rs, 'rt");
1367       break;
1368     case DSUBU:
1369       Format(instr, "dsubu   'rd, 'rs, 'rt");
1370       break;
1371     case AND:
1372       Format(instr, "and     'rd, 'rs, 'rt");
1373       break;
1374     case OR:
1375       if (0 == instr->RsValue()) {
1376         Format(instr, "mov     'rd, 'rt");
1377       } else if (0 == instr->RtValue()) {
1378         Format(instr, "mov     'rd, 'rs");
1379       } else {
1380         Format(instr, "or      'rd, 'rs, 'rt");
1381       }
1382       break;
1383     case XOR:
1384       Format(instr, "xor     'rd, 'rs, 'rt");
1385       break;
1386     case NOR:
1387       Format(instr, "nor     'rd, 'rs, 'rt");
1388       break;
1389     case SLT:
1390       Format(instr, "slt     'rd, 'rs, 'rt");
1391       break;
1392     case SLTU:
1393       Format(instr, "sltu    'rd, 'rs, 'rt");
1394       break;
1395     case TGE:
1396       Format(instr, "tge     'rs, 'rt, code: 'code");
1397       break;
1398     case TGEU:
1399       Format(instr, "tgeu    'rs, 'rt, code: 'code");
1400       break;
1401     case TLT:
1402       Format(instr, "tlt     'rs, 'rt, code: 'code");
1403       break;
1404     case TLTU:
1405       Format(instr, "tltu    'rs, 'rt, code: 'code");
1406       break;
1407     case TEQ:
1408       Format(instr, "teq     'rs, 'rt, code: 'code");
1409       break;
1410     case TNE:
1411       Format(instr, "tne     'rs, 'rt, code: 'code");
1412       break;
1413     case SYNC:
1414       Format(instr, "sync");
1415       break;
1416     case MOVZ:
1417       Format(instr, "movz    'rd, 'rs, 'rt");
1418       break;
1419     case MOVN:
1420       Format(instr, "movn    'rd, 'rs, 'rt");
1421       break;
1422     case MOVCI:
1423       if (instr->Bit(16)) {
1424         Format(instr, "movt    'rd, 'rs, 'bc");
1425       } else {
1426         Format(instr, "movf    'rd, 'rs, 'bc");
1427       }
1428       break;
1429     case SELEQZ_S:
1430       Format(instr, "seleqz    'rd, 'rs, 'rt");
1431       break;
1432     case SELNEZ_S:
1433       Format(instr, "selnez    'rd, 'rs, 'rt");
1434       break;
1435     default:
1436       UNREACHABLE();
1437   }
1438 }
1439 
1440 
DecodeTypeRegisterSPECIAL2(Instruction * instr)1441 void Decoder::DecodeTypeRegisterSPECIAL2(Instruction* instr) {
1442   switch (instr->FunctionFieldRaw()) {
1443     case MUL:
1444       Format(instr, "mul     'rd, 'rs, 'rt");
1445       break;
1446     case CLZ:
1447       if (kArchVariant != kMips64r6) {
1448         Format(instr, "clz     'rd, 'rs");
1449       }
1450       break;
1451     case DCLZ:
1452       if (kArchVariant != kMips64r6) {
1453         Format(instr, "dclz    'rd, 'rs");
1454       }
1455       break;
1456     default:
1457       UNREACHABLE();
1458   }
1459 }
1460 
1461 
DecodeTypeRegisterSPECIAL3(Instruction * instr)1462 void Decoder::DecodeTypeRegisterSPECIAL3(Instruction* instr) {
1463   switch (instr->FunctionFieldRaw()) {
1464     case INS: {
1465       Format(instr, "ins     'rt, 'rs, 'sa, 'ss2");
1466       break;
1467     }
1468     case EXT: {
1469       Format(instr, "ext     'rt, 'rs, 'sa, 'ss1");
1470       break;
1471     }
1472     case DEXT: {
1473       Format(instr, "dext    'rt, 'rs, 'sa, 'ss1");
1474       break;
1475     }
1476     case BSHFL: {
1477       int sa = instr->SaFieldRaw() >> kSaShift;
1478       switch (sa) {
1479         case BITSWAP: {
1480           Format(instr, "bitswap 'rd, 'rt");
1481           break;
1482         }
1483         case SEB: {
1484           Format(instr, "seb     'rd, 'rt");
1485           break;
1486         }
1487         case SEH: {
1488           Format(instr, "seh     'rd, 'rt");
1489           break;
1490         }
1491         case WSBH: {
1492           Format(instr, "wsbh    'rd, 'rt");
1493           break;
1494         }
1495         default: {
1496           sa >>= kBp2Bits;
1497           switch (sa) {
1498             case ALIGN: {
1499               Format(instr, "align  'rd, 'rs, 'rt, 'bp2");
1500               break;
1501             }
1502             default:
1503               UNREACHABLE();
1504               break;
1505           }
1506           break;
1507         }
1508       }
1509       break;
1510     }
1511     case DINS: {
1512       Format(instr, "dins    'rt, 'rs, 'sa, 'ss2");
1513       break;
1514     }
1515     case DBSHFL: {
1516       int sa = instr->SaFieldRaw() >> kSaShift;
1517       switch (sa) {
1518         case DBITSWAP: {
1519           switch (instr->SaFieldRaw() >> kSaShift) {
1520             case DBITSWAP_SA:
1521               Format(instr, "dbitswap 'rd, 'rt");
1522               break;
1523             default:
1524               UNREACHABLE();
1525               break;
1526           }
1527           break;
1528         }
1529         case DSBH: {
1530           Format(instr, "dsbh    'rd, 'rt");
1531           break;
1532         }
1533         case DSHD: {
1534           Format(instr, "dshd    'rd, 'rt");
1535           break;
1536         }
1537         default: {
1538           sa >>= kBp3Bits;
1539           switch (sa) {
1540             case DALIGN: {
1541               Format(instr, "dalign  'rd, 'rs, 'rt, 'bp3");
1542               break;
1543             }
1544             default:
1545               UNREACHABLE();
1546               break;
1547           }
1548           break;
1549         }
1550       }
1551       break;
1552     }
1553     default:
1554       UNREACHABLE();
1555   }
1556 }
1557 
1558 
DecodeTypeRegister(Instruction * instr)1559 int Decoder::DecodeTypeRegister(Instruction* instr) {
1560   switch (instr->OpcodeFieldRaw()) {
1561     case COP1:  // Coprocessor instructions.
1562       DecodeTypeRegisterCOP1(instr);
1563       break;
1564     case COP1X:
1565       DecodeTypeRegisterCOP1X(instr);
1566       break;
1567     case SPECIAL:
1568       switch (instr->FunctionFieldRaw()) {
1569         case BREAK:
1570           return DecodeBreakInstr(instr);
1571         default:
1572           DecodeTypeRegisterSPECIAL(instr);
1573           break;
1574       }
1575       break;
1576     case SPECIAL2:
1577       DecodeTypeRegisterSPECIAL2(instr);
1578       break;
1579     case SPECIAL3:
1580       DecodeTypeRegisterSPECIAL3(instr);
1581       break;
1582     default:
1583       UNREACHABLE();
1584   }
1585   return Instruction::kInstrSize;
1586 }
1587 
1588 
DecodeTypeImmediateCOP1(Instruction * instr)1589 void Decoder::DecodeTypeImmediateCOP1(Instruction* instr) {
1590   switch (instr->RsFieldRaw()) {
1591     case BC1:
1592       if (instr->FBtrueValue()) {
1593         Format(instr, "bc1t    'bc, 'imm16u -> 'imm16p4s2");
1594       } else {
1595         Format(instr, "bc1f    'bc, 'imm16u -> 'imm16p4s2");
1596       }
1597       break;
1598     case BC1EQZ:
1599       Format(instr, "bc1eqz    'ft, 'imm16u -> 'imm16p4s2");
1600       break;
1601     case BC1NEZ:
1602       Format(instr, "bc1nez    'ft, 'imm16u -> 'imm16p4s2");
1603       break;
1604     default:
1605       UNREACHABLE();
1606   }
1607 }
1608 
1609 
DecodeTypeImmediateREGIMM(Instruction * instr)1610 void Decoder::DecodeTypeImmediateREGIMM(Instruction* instr) {
1611   switch (instr->RtFieldRaw()) {
1612     case BLTZ:
1613       Format(instr, "bltz    'rs, 'imm16u -> 'imm16p4s2");
1614       break;
1615     case BLTZAL:
1616       Format(instr, "bltzal  'rs, 'imm16u -> 'imm16p4s2");
1617       break;
1618     case BGEZ:
1619       Format(instr, "bgez    'rs, 'imm16u -> 'imm16p4s2");
1620       break;
1621     case BGEZAL: {
1622       if (instr->RsValue() == 0)
1623         Format(instr, "bal     'imm16s -> 'imm16p4s2");
1624       else
1625         Format(instr, "bgezal  'rs, 'imm16u -> 'imm16p4s2");
1626       break;
1627     }
1628     case BGEZALL:
1629       Format(instr, "bgezall 'rs, 'imm16u -> 'imm16p4s2");
1630       break;
1631     case DAHI:
1632       Format(instr, "dahi    'rs, 'imm16x");
1633       break;
1634     case DATI:
1635       Format(instr, "dati    'rs, 'imm16x");
1636       break;
1637     default:
1638       UNREACHABLE();
1639   }
1640 }
1641 
1642 
DecodeTypeImmediate(Instruction * instr)1643 void Decoder::DecodeTypeImmediate(Instruction* instr) {
1644   switch (instr->OpcodeFieldRaw()) {
1645     case COP1:
1646       DecodeTypeImmediateCOP1(instr);
1647       break;  // Case COP1.
1648     // ------------- REGIMM class.
1649     case REGIMM:
1650       DecodeTypeImmediateREGIMM(instr);
1651       break;  // Case REGIMM.
1652     // ------------- Branch instructions.
1653     case BEQ:
1654       Format(instr, "beq     'rs, 'rt, 'imm16u -> 'imm16p4s2");
1655       break;
1656     case BC:
1657       Format(instr, "bc      'imm26s -> 'imm26p4s2");
1658       break;
1659     case BALC:
1660       Format(instr, "balc    'imm26s -> 'imm26p4s2");
1661       break;
1662     case BNE:
1663       Format(instr, "bne     'rs, 'rt, 'imm16u -> 'imm16p4s2");
1664       break;
1665     case BLEZ:
1666       if ((instr->RtValue() == 0) && (instr->RsValue() != 0)) {
1667         Format(instr, "blez    'rs, 'imm16u -> 'imm16p4s2");
1668       } else if ((instr->RtValue() != instr->RsValue()) &&
1669                  (instr->RsValue() != 0) && (instr->RtValue() != 0)) {
1670         Format(instr, "bgeuc   'rs, 'rt, 'imm16u -> 'imm16p4s2");
1671       } else if ((instr->RtValue() == instr->RsValue()) &&
1672                  (instr->RtValue() != 0)) {
1673         Format(instr, "bgezalc 'rs, 'imm16u -> 'imm16p4s2");
1674       } else if ((instr->RsValue() == 0) && (instr->RtValue() != 0)) {
1675         Format(instr, "blezalc 'rt, 'imm16u -> 'imm16p4s2");
1676       } else {
1677         UNREACHABLE();
1678       }
1679       break;
1680     case BGTZ:
1681       if ((instr->RtValue() == 0) && (instr->RsValue() != 0)) {
1682         Format(instr, "bgtz    'rs, 'imm16u -> 'imm16p4s2");
1683       } else if ((instr->RtValue() != instr->RsValue()) &&
1684                  (instr->RsValue() != 0) && (instr->RtValue() != 0)) {
1685         Format(instr, "bltuc   'rs, 'rt, 'imm16u -> 'imm16p4s2");
1686       } else if ((instr->RtValue() == instr->RsValue()) &&
1687                  (instr->RtValue() != 0)) {
1688         Format(instr, "bltzalc 'rt, 'imm16u -> 'imm16p4s2");
1689       } else if ((instr->RsValue() == 0) && (instr->RtValue() != 0)) {
1690         Format(instr, "bgtzalc 'rt, 'imm16u -> 'imm16p4s2");
1691       } else {
1692         UNREACHABLE();
1693       }
1694       break;
1695     case BLEZL:
1696       if ((instr->RtValue() == instr->RsValue()) && (instr->RtValue() != 0)) {
1697         Format(instr, "bgezc    'rt, 'imm16u -> 'imm16p4s2");
1698       } else if ((instr->RtValue() != instr->RsValue()) &&
1699                  (instr->RsValue() != 0) && (instr->RtValue() != 0)) {
1700         Format(instr, "bgec     'rs, 'rt, 'imm16u -> 'imm16p4s2");
1701       } else if ((instr->RsValue() == 0) && (instr->RtValue() != 0)) {
1702         Format(instr, "blezc    'rt, 'imm16u -> 'imm16p4s2");
1703       } else {
1704         UNREACHABLE();
1705       }
1706       break;
1707     case BGTZL:
1708       if ((instr->RtValue() == instr->RsValue()) && (instr->RtValue() != 0)) {
1709         Format(instr, "bltzc    'rt, 'imm16u -> 'imm16p4s2");
1710       } else if ((instr->RtValue() != instr->RsValue()) &&
1711                  (instr->RsValue() != 0) && (instr->RtValue() != 0)) {
1712         Format(instr, "bltc    'rs, 'rt, 'imm16u -> 'imm16p4s2");
1713       } else if ((instr->RsValue() == 0) && (instr->RtValue() != 0)) {
1714         Format(instr, "bgtzc    'rt, 'imm16u -> 'imm16p4s2");
1715       } else {
1716         UNREACHABLE();
1717       }
1718       break;
1719     case POP66:
1720       if (instr->RsValue() == JIC) {
1721         Format(instr, "jic     'rt, 'imm16s");
1722       } else {
1723         Format(instr, "beqzc   'rs, 'imm21s -> 'imm21p4s2");
1724       }
1725       break;
1726     case POP76:
1727       if (instr->RsValue() == JIALC) {
1728         Format(instr, "jialc   'rt, 'imm16s");
1729       } else {
1730         Format(instr, "bnezc   'rs, 'imm21s -> 'imm21p4s2");
1731       }
1732       break;
1733     // ------------- Arithmetic instructions.
1734     case ADDI:
1735       if (kArchVariant != kMips64r6) {
1736         Format(instr, "addi    'rt, 'rs, 'imm16s");
1737       } else {
1738         int rs_reg = instr->RsValue();
1739         int rt_reg = instr->RtValue();
1740         // Check if BOVC, BEQZALC or BEQC instruction.
1741         if (rs_reg >= rt_reg) {
1742           Format(instr, "bovc  'rs, 'rt, 'imm16s -> 'imm16p4s2");
1743         } else {
1744           DCHECK(rt_reg > 0);
1745           if (rs_reg == 0) {
1746             Format(instr, "beqzalc 'rt, 'imm16s -> 'imm16p4s2");
1747           } else {
1748             Format(instr, "beqc    'rs, 'rt, 'imm16s -> 'imm16p4s2");
1749           }
1750         }
1751       }
1752       break;
1753     case DADDI:
1754       if (kArchVariant != kMips64r6) {
1755         Format(instr, "daddi   'rt, 'rs, 'imm16s");
1756       } else {
1757         int rs_reg = instr->RsValue();
1758         int rt_reg = instr->RtValue();
1759         // Check if BNVC, BNEZALC or BNEC instruction.
1760         if (rs_reg >= rt_reg) {
1761           Format(instr, "bnvc  'rs, 'rt, 'imm16s -> 'imm16p4s2");
1762         } else {
1763           DCHECK(rt_reg > 0);
1764           if (rs_reg == 0) {
1765             Format(instr, "bnezalc 'rt, 'imm16s -> 'imm16p4s2");
1766           } else {
1767             Format(instr, "bnec  'rs, 'rt, 'imm16s -> 'imm16p4s2");
1768           }
1769         }
1770       }
1771       break;
1772     case ADDIU:
1773       Format(instr, "addiu   'rt, 'rs, 'imm16s");
1774       break;
1775     case DADDIU:
1776       Format(instr, "daddiu  'rt, 'rs, 'imm16s");
1777       break;
1778     case SLTI:
1779       Format(instr, "slti    'rt, 'rs, 'imm16s");
1780       break;
1781     case SLTIU:
1782       Format(instr, "sltiu   'rt, 'rs, 'imm16u");
1783       break;
1784     case ANDI:
1785       Format(instr, "andi    'rt, 'rs, 'imm16x");
1786       break;
1787     case ORI:
1788       Format(instr, "ori     'rt, 'rs, 'imm16x");
1789       break;
1790     case XORI:
1791       Format(instr, "xori    'rt, 'rs, 'imm16x");
1792       break;
1793     case LUI:
1794       if (kArchVariant != kMips64r6) {
1795         Format(instr, "lui     'rt, 'imm16x");
1796       } else {
1797         if (instr->RsValue() != 0) {
1798           Format(instr, "aui     'rt, 'rs, 'imm16x");
1799         } else {
1800           Format(instr, "lui     'rt, 'imm16x");
1801         }
1802       }
1803       break;
1804     case DAUI:
1805       Format(instr, "daui    'rt, 'rs, 'imm16x");
1806       break;
1807     // ------------- Memory instructions.
1808     case LB:
1809       Format(instr, "lb      'rt, 'imm16s('rs)");
1810       break;
1811     case LH:
1812       Format(instr, "lh      'rt, 'imm16s('rs)");
1813       break;
1814     case LWL:
1815       Format(instr, "lwl     'rt, 'imm16s('rs)");
1816       break;
1817     case LDL:
1818       Format(instr, "ldl     'rt, 'imm16s('rs)");
1819       break;
1820     case LW:
1821       Format(instr, "lw      'rt, 'imm16s('rs)");
1822       break;
1823     case LWU:
1824       Format(instr, "lwu     'rt, 'imm16s('rs)");
1825       break;
1826     case LD:
1827       Format(instr, "ld      'rt, 'imm16s('rs)");
1828       break;
1829     case LBU:
1830       Format(instr, "lbu     'rt, 'imm16s('rs)");
1831       break;
1832     case LHU:
1833       Format(instr, "lhu     'rt, 'imm16s('rs)");
1834       break;
1835     case LWR:
1836       Format(instr, "lwr     'rt, 'imm16s('rs)");
1837       break;
1838     case LDR:
1839       Format(instr, "ldr     'rt, 'imm16s('rs)");
1840       break;
1841     case PREF:
1842       Format(instr, "pref    'rt, 'imm16s('rs)");
1843       break;
1844     case SB:
1845       Format(instr, "sb      'rt, 'imm16s('rs)");
1846       break;
1847     case SH:
1848       Format(instr, "sh      'rt, 'imm16s('rs)");
1849       break;
1850     case SWL:
1851       Format(instr, "swl     'rt, 'imm16s('rs)");
1852       break;
1853     case SW:
1854       Format(instr, "sw      'rt, 'imm16s('rs)");
1855       break;
1856     case SD:
1857       Format(instr, "sd      'rt, 'imm16s('rs)");
1858       break;
1859     case SWR:
1860       Format(instr, "swr     'rt, 'imm16s('rs)");
1861       break;
1862     case LWC1:
1863       Format(instr, "lwc1    'ft, 'imm16s('rs)");
1864       break;
1865     case LDC1:
1866       Format(instr, "ldc1    'ft, 'imm16s('rs)");
1867       break;
1868     case SWC1:
1869       Format(instr, "swc1    'ft, 'imm16s('rs)");
1870       break;
1871     case SDC1:
1872       Format(instr, "sdc1    'ft, 'imm16s('rs)");
1873       break;
1874     case PCREL: {
1875       int32_t imm21 = instr->Imm21Value();
1876       // rt field: 5-bits checking
1877       uint8_t rt = (imm21 >> kImm16Bits);
1878       switch (rt) {
1879         case ALUIPC:
1880           Format(instr, "aluipc  'rs, 'imm16s");
1881           break;
1882         case AUIPC:
1883           Format(instr, "auipc   'rs, 'imm16s");
1884           break;
1885         default: {
1886           // rt field: checking of the most significant 3-bits
1887           rt = (imm21 >> kImm18Bits);
1888           switch (rt) {
1889             case LDPC:
1890               Format(instr, "ldpc    'rs, 'imm18s");
1891               break;
1892             default: {
1893               // rt field: checking of the most significant 2-bits
1894               rt = (imm21 >> kImm19Bits);
1895               switch (rt) {
1896                 case LWUPC:
1897                   Format(instr, "lwupc   'rs, 'imm19s");
1898                   break;
1899                 case LWPC:
1900                   Format(instr, "lwpc    'rs, 'imm19s");
1901                   break;
1902                 case ADDIUPC:
1903                   Format(instr, "addiupc 'rs, 'imm19s");
1904                   break;
1905                 default:
1906                   UNREACHABLE();
1907                   break;
1908               }
1909               break;
1910             }
1911           }
1912           break;
1913         }
1914       }
1915       break;
1916     }
1917     default:
1918       printf("a 0x%x \n", instr->OpcodeFieldRaw());
1919       UNREACHABLE();
1920       break;
1921   }
1922 }
1923 
1924 
DecodeTypeJump(Instruction * instr)1925 void Decoder::DecodeTypeJump(Instruction* instr) {
1926   switch (instr->OpcodeFieldRaw()) {
1927     case J:
1928       Format(instr, "j       'imm26x -> 'imm26j");
1929       break;
1930     case JAL:
1931       Format(instr, "jal     'imm26x -> 'imm26j");
1932       break;
1933     default:
1934       UNREACHABLE();
1935   }
1936 }
1937 
1938 
1939 // Disassemble the instruction at *instr_ptr into the output buffer.
1940 // All instructions are one word long, except for the simulator
1941 // psuedo-instruction stop(msg). For that one special case, we return
1942 // size larger than one kInstrSize.
InstructionDecode(byte * instr_ptr)1943 int Decoder::InstructionDecode(byte* instr_ptr) {
1944   Instruction* instr = Instruction::At(instr_ptr);
1945   // Print raw instruction bytes.
1946   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_,
1947                               "%08x       ",
1948                               instr->InstructionBits());
1949   switch (instr->InstructionType()) {
1950     case Instruction::kRegisterType: {
1951       return DecodeTypeRegister(instr);
1952     }
1953     case Instruction::kImmediateType: {
1954       DecodeTypeImmediate(instr);
1955       break;
1956     }
1957     case Instruction::kJumpType: {
1958       DecodeTypeJump(instr);
1959       break;
1960     }
1961     default: {
1962       Format(instr, "UNSUPPORTED");
1963       UNSUPPORTED_MIPS();
1964     }
1965   }
1966   return Instruction::kInstrSize;
1967 }
1968 
1969 
1970 }  // namespace internal
1971 }  // namespace v8
1972 
1973 
1974 //------------------------------------------------------------------------------
1975 
1976 namespace disasm {
1977 
NameOfAddress(byte * addr) const1978 const char* NameConverter::NameOfAddress(byte* addr) const {
1979   v8::internal::SNPrintF(tmp_buffer_, "%p", static_cast<void*>(addr));
1980   return tmp_buffer_.start();
1981 }
1982 
1983 
NameOfConstant(byte * addr) const1984 const char* NameConverter::NameOfConstant(byte* addr) const {
1985   return NameOfAddress(addr);
1986 }
1987 
1988 
NameOfCPURegister(int reg) const1989 const char* NameConverter::NameOfCPURegister(int reg) const {
1990   return v8::internal::Registers::Name(reg);
1991 }
1992 
1993 
NameOfXMMRegister(int reg) const1994 const char* NameConverter::NameOfXMMRegister(int reg) const {
1995   return v8::internal::FPURegisters::Name(reg);
1996 }
1997 
1998 
NameOfByteCPURegister(int reg) const1999 const char* NameConverter::NameOfByteCPURegister(int reg) const {
2000   UNREACHABLE();  // MIPS does not have the concept of a byte register.
2001   return "nobytereg";
2002 }
2003 
2004 
NameInCode(byte * addr) const2005 const char* NameConverter::NameInCode(byte* addr) const {
2006   // The default name converter is called for unknown code. So we will not try
2007   // to access any memory.
2008   return "";
2009 }
2010 
2011 
2012 //------------------------------------------------------------------------------
2013 
Disassembler(const NameConverter & converter)2014 Disassembler::Disassembler(const NameConverter& converter)
2015     : converter_(converter) {}
2016 
2017 
~Disassembler()2018 Disassembler::~Disassembler() {}
2019 
2020 
InstructionDecode(v8::internal::Vector<char> buffer,byte * instruction)2021 int Disassembler::InstructionDecode(v8::internal::Vector<char> buffer,
2022                                     byte* instruction) {
2023   v8::internal::Decoder d(converter_, buffer);
2024   return d.InstructionDecode(instruction);
2025 }
2026 
2027 
2028 // The MIPS assembler does not currently use constant pools.
ConstantPoolSizeAt(byte * instruction)2029 int Disassembler::ConstantPoolSizeAt(byte* instruction) {
2030   return -1;
2031 }
2032 
2033 
Disassemble(FILE * f,byte * begin,byte * end)2034 void Disassembler::Disassemble(FILE* f, byte* begin, byte* end) {
2035   NameConverter converter;
2036   Disassembler d(converter);
2037   for (byte* pc = begin; pc < end;) {
2038     v8::internal::EmbeddedVector<char, 128> buffer;
2039     buffer[0] = '\0';
2040     byte* prev_pc = pc;
2041     pc += d.InstructionDecode(buffer, pc);
2042     v8::internal::PrintF(f, "%p    %08x      %s\n", static_cast<void*>(prev_pc),
2043                          *reinterpret_cast<int32_t*>(prev_pc), buffer.start());
2044   }
2045 }
2046 
2047 
2048 #undef UNSUPPORTED
2049 
2050 }  // namespace disasm
2051 
2052 #endif  // V8_TARGET_ARCH_MIPS64
2053