Bug fix for infinite loop in analysis stepper.
[dyninst.git] / instructionAPI / src / InstructionDecoder-x86.C
1 /*
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30
31 #define INSIDE_INSTRUCTION_API
32
33 #include "common/h/Types.h"
34 #include "InstructionDecoder-x86.h"
35 #include "Expression.h"
36 #include "common/h/arch-x86.h"
37 #include "Register.h"
38 #include "Dereference.h"
39 #include "Immediate.h" 
40 #include "BinaryFunction.h"
41 #include "common/h/singleton_object_pool.h"
42
43 using namespace std;
44 using namespace NS_x86;
45 namespace Dyninst
46 {
47     namespace InstructionAPI
48     {
49     
50         bool readsOperand(unsigned int opsema, unsigned int i)
51         {
52             switch(opsema) {
53                 case s1R2R:
54                     return (i == 0 || i == 1);
55                 case s1R:
56                 case s1RW:
57                     return i == 0;
58                 case s1W:
59                     return false;
60                 case s1W2RW:
61                 case s1W2R:   // second operand read, first operand written (e.g. mov)
62                     return i == 1;
63                 case s1RW2R:  // two operands read, first written (e.g. add)
64                 case s1RW2RW: // e.g. xchg
65                 case s1R2RW:
66                     return i == 0 || i == 1;
67                 case s1W2R3R: // e.g. imul
68                 case s1W2RW3R: // some mul
69                 case s1W2R3RW: // (stack) push & pop
70                     return i == 1 || i == 2;
71                 case s1W2W3R: // e.g. les
72                     return i == 2;
73                 case s1RW2R3R: // shld/shrd
74                 case s1RW2RW3R: // [i]div, cmpxch8b
75                 case s1R2R3R:
76                     return i == 0 || i == 1 || i == 2;
77                     break;
78                 case sNONE:
79                 default:
80                     return false;
81             }
82       
83         }
84       
85         bool writesOperand(unsigned int opsema, unsigned int i)
86         {
87             switch(opsema) {
88                 case s1R2R:
89                 case s1R:
90                     return false;
91                 case s1RW:
92                 case s1W:
93                     case s1W2R:   // second operand read, first operand written (e.g. mov)
94                         case s1RW2R:  // two operands read, first written (e.g. add)
95                             case s1W2R3R: // e.g. imul
96                                 case s1RW2R3R: // shld/shrd
97                                     return i == 0;
98                 case s1R2RW:
99                     return i == 1;
100                 case s1W2RW:
101                     case s1RW2RW: // e.g. xchg
102                         case s1W2RW3R: // some mul
103                             case s1W2W3R: // e.g. les
104                                 case s1RW2RW3R: // [i]div, cmpxch8b
105                                     return i == 0 || i == 1;
106                                     case s1W2R3RW: // (stack) push & pop
107                                         return i == 0 || i == 2;
108                 case sNONE:
109                 default:
110                     return false;
111             }
112         }
113
114
115     
116     INSTRUCTION_EXPORT InstructionDecoder_x86::InstructionDecoder_x86(Architecture a) :
117       InstructionDecoderImpl(a),
118     locs(NULL),
119     decodedInstruction(NULL),
120     sizePrefixPresent(false)
121     {
122     }
123     INSTRUCTION_EXPORT InstructionDecoder_x86::~InstructionDecoder_x86()
124     {
125         if(decodedInstruction) decodedInstruction->~ia32_instruction();
126         free(decodedInstruction);
127         if(locs) locs->~ia32_locations();
128         free(locs);
129
130     }
131     static const unsigned char modrm_use_sib = 4;
132     
133     INSTRUCTION_EXPORT void InstructionDecoder_x86::setMode(bool is64)
134     {
135         ia32_set_mode_64(is64);
136     }
137     
138       Expression::Ptr InstructionDecoder_x86::makeSIBExpression(const InstructionDecoder::buffer& b)
139     {
140         unsigned scale;
141         Register index;
142         Register base;
143         Result_Type registerType = ia32_is_mode_64() ? u32 : u64;
144
145         decode_SIB(locs->sib_byte, scale, index, base);
146
147         Expression::Ptr scaleAST(make_shared(singleton_object_pool<Immediate>::construct(Result(u8, dword_t(scale)))));
148         Expression::Ptr indexAST(make_shared(singleton_object_pool<RegisterAST>::construct(makeRegisterID(index, registerType,
149                                     locs->rex_x))));
150         Expression::Ptr baseAST;
151         if(base == 0x05)
152         {
153             switch(locs->modrm_mod)
154             {
155                 case 0x00:
156                     baseAST = decodeImmediate(op_d, b.start + locs->sib_position + 1);
157                     break;
158                     case 0x01: {
159                         MachRegister reg;
160                         if (locs->rex_b)
161                             reg = x86_64::r13;
162                         else
163                           reg = MachRegister::getFramePointer(m_Arch);
164                         
165                         baseAST = makeAddExpression(make_shared(singleton_object_pool<RegisterAST>::construct(reg)),
166                                                     decodeImmediate(op_b, b.start + locs->sib_position + 1),
167                                                     registerType);
168                         break;
169                     }
170                     case 0x02: {
171                         MachRegister reg;
172                         if (locs->rex_b)
173                             reg = x86_64::r13;
174                         else
175                             reg = MachRegister::getFramePointer(m_Arch);
176
177                         baseAST = makeAddExpression(make_shared(singleton_object_pool<RegisterAST>::construct(reg)), 
178                                                     decodeImmediate(op_d, b.start + locs->sib_position + 1),
179                                                     registerType);
180                         break;
181                     }
182                 case 0x03:
183                 default:
184                     assert(0);
185                     break;
186             };
187         }
188         else
189         {
190             baseAST = make_shared(singleton_object_pool<RegisterAST>::construct(makeRegisterID(base, 
191                                                                                                registerType,
192                                                                                                locs->rex_b)));
193         }
194         if(index == 0x04 && (!(ia32_is_mode_64()) || !(locs->rex_x)))
195         {
196             return baseAST;
197         }
198         return makeAddExpression(baseAST, makeMultiplyExpression(indexAST, scaleAST, registerType), registerType);
199     }
200
201       Expression::Ptr InstructionDecoder_x86::makeModRMExpression(const InstructionDecoder::buffer& b,
202                                                                   unsigned int opType)
203     {
204        unsigned int regType = op_d;
205         Result_Type aw = ia32_is_mode_64() ? u32 : u64;
206         if(ia32_is_mode_64())
207         {
208             regType = op_q;
209         }
210         Expression::Ptr e =
211             makeRegisterExpression(makeRegisterID(locs->modrm_rm, regType, (locs->rex_b == 1)));
212         switch(locs->modrm_mod)
213         {
214             case 0:
215                 if(locs->modrm_rm == modrm_use_sib) {
216                     e = makeSIBExpression(b);
217                 }
218                 if(locs->modrm_rm == 0x5 && !addrSizePrefixPresent)
219                 {
220                     assert(locs->opcode_position > -1);
221                     if(ia32_is_mode_64())
222                     {
223                         e = makeAddExpression(makeRegisterExpression(x86_64::rip),
224                                             getModRMDisplacement(b), aw);
225                     }
226                     else
227                     {
228                         e = getModRMDisplacement(b);
229                     }
230         
231                 }
232                 if(locs->modrm_rm == 0x6 && addrSizePrefixPresent)
233                 {
234                     e = getModRMDisplacement(b);
235                 }
236                 if(opType == op_lea)
237                 {
238                     return e;
239                 }
240                 return makeDereferenceExpression(e, makeSizeType(opType));
241                 assert(0);
242                 break;
243             case 1:
244             case 2:
245             {
246                 if(locs->modrm_rm == modrm_use_sib) {
247                     e = makeSIBExpression(b);
248                 }
249                 Expression::Ptr disp_e = makeAddExpression(e, getModRMDisplacement(b), aw);
250                 if(opType == op_lea)
251                 {
252                     return disp_e;
253                 }
254                 return makeDereferenceExpression(disp_e, makeSizeType(opType));
255             }
256             assert(0);
257             break;
258             case 3:
259                 return makeRegisterExpression(makeRegisterID(locs->modrm_rm, opType, (locs->rex_b == 1)));
260             default:
261                 return Expression::Ptr();
262         
263         };
264         // can't get here, but make the compiler happy...
265         assert(0);
266         return Expression::Ptr();
267     }
268
269     Expression::Ptr InstructionDecoder_x86::decodeImmediate(unsigned int opType, const unsigned char* immStart, 
270                                                             bool isSigned)
271     {
272         switch(opType)
273         {
274             case op_b:
275                 return Immediate::makeImmediate(Result(isSigned ? s8 : u8 ,*(const byte_t*)(immStart)));
276                 break;
277             case op_d:
278                 return Immediate::makeImmediate(Result(isSigned ? s32 : u32,*(const dword_t*)(immStart)));
279             case op_w:
280                 return Immediate::makeImmediate(Result(isSigned ? s16 : u16,*(const word_t*)(immStart)));
281                 break;
282             case op_q:
283                 return Immediate::makeImmediate(Result(isSigned ? s64 : u64,*(const int64_t*)(immStart)));
284                 break;
285             case op_v:
286             case op_z:
287         // 32 bit mode & no prefix, or 16 bit mode & prefix => 32 bit
288         // 16 bit mode, no prefix or 32 bit mode, prefix => 16 bit
289               if (locs->rex_w) {
290                     return Immediate::makeImmediate(Result(isSigned ? s64 : u64,*(const int64_t*)(immStart)));
291               }
292               else if(!sizePrefixPresent)
293               {
294                 return Immediate::makeImmediate(Result(isSigned ? s32 : u32,*(const dword_t*)(immStart)));
295               }
296               else
297               {
298                 return Immediate::makeImmediate(Result(isSigned ? s16 : u16,*(const word_t*)(immStart)));
299               }
300               break;
301             case op_p:
302         // 32 bit mode & no prefix, or 16 bit mode & prefix => 48 bit
303         // 16 bit mode, no prefix or 32 bit mode, prefix => 32 bit
304                 if(!sizePrefixPresent)
305                 {
306                     return Immediate::makeImmediate(Result(isSigned ? s48 : u48,*(const int64_t*)(immStart)));
307                 }
308                 else
309                 {
310                     return Immediate::makeImmediate(Result(isSigned ? s32 : u32,*(const dword_t*)(immStart)));
311                 }
312         
313                 break;
314             case op_a:
315             case op_dq:
316             case op_pd:
317             case op_ps:
318             case op_s:
319             case op_si:
320             case op_lea:
321             case op_allgprs:
322             case op_512:
323             case op_c:
324                 assert(!"Can't happen: opType unexpected for valid ways to decode an immediate");
325                 return Expression::Ptr();
326             default:
327                 assert(!"Can't happen: opType out of range");
328                 return Expression::Ptr();
329         }
330     }
331     
332     Expression::Ptr InstructionDecoder_x86::getModRMDisplacement(const InstructionDecoder::buffer& b)
333     {
334         int disp_pos;
335
336         if(locs->sib_position != -1)
337         {
338             disp_pos = locs->sib_position + 1;
339         }
340         else
341         {
342             disp_pos = locs->modrm_position + 1;
343         }
344         switch(locs->modrm_mod)
345         {
346             case 1:
347                 return make_shared(singleton_object_pool<Immediate>::construct(Result(s8, (*(const byte_t*)(b.start +
348                         disp_pos)))));
349                 break;
350             case 2:
351                 if(sizePrefixPresent)
352                 {
353                     return make_shared(singleton_object_pool<Immediate>::construct(Result(s16, *((const word_t*)(b.start +
354                             disp_pos)))));
355                 }
356                 else
357                 {
358                     return make_shared(singleton_object_pool<Immediate>::construct(Result(s32, *((const dword_t*)(b.start +
359                             disp_pos)))));
360                 }
361                 break;
362             case 0:
363                 // In 16-bit mode, the word displacement is modrm r/m 6
364                 if(sizePrefixPresent)
365                 {
366                     if(locs->modrm_rm == 6)
367                     {
368                         return make_shared(singleton_object_pool<Immediate>::construct(Result(s16,
369                                            *((const dword_t*)(b.start + disp_pos)))));
370                     }
371                     // TODO FIXME; this was decoding wrong, but I'm not sure
372                     // why...
373                     else if (locs->modrm_rm == 5) {
374                         assert(b.start + disp_pos + 4 <= b.end);
375                         return make_shared(singleton_object_pool<Immediate>::construct(Result(s32,
376                                            *((const dword_t*)(b.start + disp_pos)))));
377                     } else {
378                         assert(b.start + disp_pos + 1 <= b.end);
379                         return make_shared(singleton_object_pool<Immediate>::construct(Result(s8, 0)));
380                     }
381                     break;
382                 }
383                 // ...and in 32-bit mode, the dword displacement is modrm r/m 5
384                 else
385                 {
386                     if(locs->modrm_rm == 5)
387                     {
388                         assert(b.start + disp_pos + 4 <= b.end);
389                         return make_shared(singleton_object_pool<Immediate>::construct(Result(s32,
390                                            *((const dword_t*)(b.start + disp_pos)))));
391                     }
392                     else
393                     {
394                         assert(b.start + disp_pos + 1 <= b.end);
395                         return make_shared(singleton_object_pool<Immediate>::construct(Result(s8, 0)));
396                     }
397                     break;
398                 }
399             default:
400                 assert(b.start + disp_pos + 1 <= b.end);
401                 return make_shared(singleton_object_pool<Immediate>::construct(Result(s8, 0)));
402                 break;
403         }
404     }
405
406     enum intelRegBanks
407     {
408         b_8bitNoREX = 0,
409         b_16bit,
410         b_32bit,
411         b_segment,
412         b_64bit,
413         b_xmm,
414         b_xmmhigh,
415         b_mm,
416         b_cr,
417         b_dr,
418         b_tr,
419         b_amd64ext,
420         b_8bitWithREX,
421         b_fpstack,
422         amd64_ext_8,
423         amd64_ext_16,
424         amd64_ext_32
425     };
426     static MachRegister IntelRegTable32[][8] = {
427         {
428             x86::al, x86::cl, x86::dl, x86::bl, x86::ah, x86::ch, x86::dh, x86::bh
429         },
430         {
431             x86::ax, x86::cx, x86::dx, x86::bx, x86::sp, x86::bp, x86::si, x86::di
432         },
433         {
434             x86::eax, x86::ecx, x86::edx, x86::ebx, x86::esp, x86::ebp, x86::esi, x86::edi
435         },
436         {
437            x86::es, x86::cs, x86::ss, x86::ds, x86::fs, x86::gs, InvalidReg, InvalidReg
438         },
439         {
440             x86_64::rax, x86_64::rcx, x86_64::rdx, x86_64::rbx, x86_64::rsp, x86_64::rbp, x86_64::rsi, x86_64::rdi
441         },
442         {
443             x86::xmm0, x86::xmm1, x86::xmm2, x86::xmm3, x86::xmm4, x86::xmm5, x86::xmm6, x86::xmm7
444         },
445         {
446             x86_64::xmm8, x86_64::xmm9, x86_64::xmm10, x86_64::xmm11, x86_64::xmm12, x86_64::xmm13, x86_64::xmm14, x86_64::xmm15
447         },
448         {
449             x86::mm0, x86::mm1, x86::mm2, x86::mm3, x86::mm4, x86::mm5, x86::mm6, x86::mm7
450         },
451         {
452             x86::cr0, x86::cr1, x86::cr2, x86::cr3, x86::cr4, x86::cr5, x86::cr6, x86::cr7
453         },
454         {
455             x86::dr0, x86::dr1, x86::dr2, x86::dr3, x86::dr4, x86::dr5, x86::dr6, x86::dr7
456         },
457         {
458             x86::tr0, x86::tr1, x86::tr2, x86::tr3, x86::tr4, x86::tr5, x86::tr6, x86::tr7
459         },
460         {
461             x86_64::r8, x86_64::r9, x86_64::r10, x86_64::r11, x86_64::r12, x86_64::r13, x86_64::r14, x86_64::r15
462         },
463         {
464             x86_64::al, x86_64::cl, x86_64::dl, x86_64::bl, x86_64::spl, x86_64::bpl, x86_64::sil, x86_64::dil
465         },
466         {
467             x86::st0, x86::st1, x86::st2, x86::st3, x86::st4, x86::st5, x86::st6, x86::st7
468         }
469
470     };
471     static MachRegister IntelRegTable64[][8] = {
472         {
473             x86_64::al, x86_64::cl, x86_64::dl, x86_64::bl, x86_64::ah, x86_64::ch, x86_64::dh, x86_64::bh
474         },
475         {
476             x86_64::ax, x86_64::cx, x86_64::dx, x86_64::bx, x86_64::sp, x86_64::bp, x86_64::si, x86_64::di
477         },
478         {
479             x86_64::eax, x86_64::ecx, x86_64::edx, x86_64::ebx, x86_64::esp, x86_64::ebp, x86_64::esi, x86_64::edi
480         },
481         {
482             x86_64::es, x86_64::cs, x86_64::ss, x86_64::ds, x86_64::fs, x86_64::gs, InvalidReg, InvalidReg
483         },
484         {
485             x86_64::rax, x86_64::rcx, x86_64::rdx, x86_64::rbx, x86_64::rsp, x86_64::rbp, x86_64::rsi, x86_64::rdi
486         },
487         {
488             x86_64::xmm0, x86_64::xmm1, x86_64::xmm2, x86_64::xmm3, x86_64::xmm4, x86_64::xmm5, x86_64::xmm6, x86_64::xmm7
489         },
490         {
491             x86_64::xmm8, x86_64::xmm9, x86_64::xmm10, x86_64::xmm11, x86_64::xmm12, x86_64::xmm13, x86_64::xmm14, x86_64::xmm15
492         },
493         {
494             x86_64::mm0, x86_64::mm1, x86_64::mm2, x86_64::mm3, x86_64::mm4, x86_64::mm5, x86_64::mm6, x86_64::mm7
495         },
496         {
497             x86_64::cr0, x86_64::cr1, x86_64::cr2, x86_64::cr3, x86_64::cr4, x86_64::cr5, x86_64::cr6, x86_64::cr7
498         },
499         {
500             x86_64::dr0, x86_64::dr1, x86_64::dr2, x86_64::dr3, x86_64::dr4, x86_64::dr5, x86_64::dr6, x86_64::dr7
501         },
502         {
503             x86_64::tr0, x86_64::tr1, x86_64::tr2, x86_64::tr3, x86_64::tr4, x86_64::tr5, x86_64::tr6, x86_64::tr7
504         },
505         {
506             x86_64::r8, x86_64::r9, x86_64::r10, x86_64::r11, x86_64::r12, x86_64::r13, x86_64::r14, x86_64::r15
507         },
508         {
509             x86_64::al, x86_64::cl, x86_64::dl, x86_64::bl, x86_64::spl, x86_64::bpl, x86_64::sil, x86_64::dil
510         },
511         {
512             x86_64::st0, x86_64::st1, x86_64::st2, x86_64::st3, x86_64::st4, x86_64::st5, x86_64::st6, x86_64::st7
513         },
514         {
515             x86_64::r8b, x86_64::r9b, x86_64::r10b, x86_64::r11b, x86_64::r12b, x86_64::r13b, x86_64::r14b, x86_64::r15b 
516         },
517         {
518             x86_64::r8w, x86_64::r9w, x86_64::r10w, x86_64::r11w, x86_64::r12w, x86_64::r13w, x86_64::r14w, x86_64::r15w 
519         },
520         {
521             x86_64::r8d, x86_64::r9d, x86_64::r10d, x86_64::r11d, x86_64::r12d, x86_64::r13d, x86_64::r14d, x86_64::r15d 
522         }
523
524     };
525
526   /* Uses the appropriate lookup table based on the 
527      decoder architecture */
528   class IntelRegTable_access {
529     public:
530         inline MachRegister operator()(Architecture arch,
531                                        intelRegBanks bank,
532                                        int index)
533         {
534             assert(index >= 0 && index < 8);
535     
536             if(arch == Arch_x86_64)
537                 return IntelRegTable64[bank][index];
538             else if(arch == Arch_x86) 
539             {
540               assert(bank <= b_fpstack);
541               return IntelRegTable32[bank][index];
542             }
543             
544             else
545                 assert(0);
546             return IntelRegTable32[bank][index];
547         }
548
549   };
550   static IntelRegTable_access IntelRegTable;
551
552       bool InstructionDecoder_x86::isDefault64Insn()
553       {
554         switch(m_Operation->getID())
555         {
556         case e_jmp:
557         case e_pop:
558         case e_push:
559         case e_call:
560           return true;
561         default:
562           return false;
563         }
564         
565       }
566       
567
568     MachRegister InstructionDecoder_x86::makeRegisterID(unsigned int intelReg, unsigned int opType,
569                                         bool isExtendedReg)
570     {
571         MachRegister retVal;
572         
573
574         if(isExtendedReg)
575         {
576             switch(opType)
577             {
578                 case op_q:  
579                     retVal = IntelRegTable(m_Arch,b_amd64ext,intelReg);
580                     break;
581                 case op_d:
582                     retVal = IntelRegTable(m_Arch,amd64_ext_32,intelReg);
583                     break;
584                 case op_w:
585                     retVal = IntelRegTable(m_Arch,amd64_ext_16,intelReg);
586                     break;
587                 case op_b:
588                     retVal = IntelRegTable(m_Arch,amd64_ext_8,intelReg);
589                     break;
590                 case op_v:
591                     if (locs->rex_w)
592                         retVal = IntelRegTable(m_Arch, b_amd64ext, intelReg);
593                     else if (!sizePrefixPresent)
594                         retVal = IntelRegTable(m_Arch, b_amd64ext, intelReg);
595                     else
596                         retVal = IntelRegTable(m_Arch, amd64_ext_16, intelReg);
597                     break;      
598                 case op_p:
599                 case op_z:
600                     if (!sizePrefixPresent)
601                         retVal = IntelRegTable(m_Arch, amd64_ext_32, intelReg);
602                     else
603                         retVal = IntelRegTable(m_Arch, amd64_ext_16, intelReg);
604                     break;
605                 default:
606                     fprintf(stderr, "%d\n", opType);
607                     fprintf(stderr, "%s\n",  decodedInstruction->getEntry()->name(locs));
608                     assert(0 && "opType=" && opType);
609             }
610         }
611         /* Promotion to 64-bit only applies to the operand types
612            that are varible (c,v,z). Ignoring c and z because they
613            do the right thing on 32- and 64-bit code.
614         else if(locs->rex_w)
615         {
616             // AMD64 with 64-bit operands
617             retVal = IntelRegTable[b_64bit][intelReg];
618         }
619         */
620         else
621         {
622             switch(opType)
623             {
624                 case op_v:
625                   if(locs->rex_w || isDefault64Insn())
626                         retVal = IntelRegTable(m_Arch,b_64bit,intelReg);
627                     else
628                         retVal = IntelRegTable(m_Arch,b_32bit,intelReg);
629                     break;
630                 case op_b:
631                     if (locs->rex_position == -1) {
632                         retVal = IntelRegTable(m_Arch,b_8bitNoREX,intelReg);
633                     } else {
634                         retVal = IntelRegTable(m_Arch,b_8bitWithREX,intelReg);
635                     }
636                     break;
637                 case op_q:
638                     retVal = IntelRegTable(m_Arch,b_64bit,intelReg);
639                     break;
640                 case op_w:
641                     retVal = IntelRegTable(m_Arch,b_16bit,intelReg);
642                     break;
643                 case op_f:
644                 case op_dbl:
645                     retVal = IntelRegTable(m_Arch,b_fpstack,intelReg);
646                     break;
647                 case op_d:
648                 case op_si:
649                     retVal = IntelRegTable(m_Arch,b_32bit,intelReg);
650                     break;
651                 default:
652                     retVal = IntelRegTable(m_Arch,b_32bit,intelReg);
653                     break;
654             }
655         }
656
657         if (!ia32_is_mode_64()) {
658           if ((retVal.val() & 0x00ffffff) == 0x0001000c)
659             assert(0);
660         }
661
662         return MachRegister((retVal.val() & ~retVal.getArchitecture()) | m_Arch);
663     }
664     
665     Result_Type InstructionDecoder_x86::makeSizeType(unsigned int opType)
666     {
667         switch(opType)
668         {
669             case op_b:
670             case op_c:
671                 return u8;
672             case op_d:
673             case op_ss:
674             case op_allgprs:
675             case op_si:
676                 return u32;
677             case op_w:
678             case op_a:
679                 return u16;
680             case op_q:
681             case op_sd:
682                 return u64;
683             case op_v:
684             case op_lea:
685             case op_z:
686               if(!ia32_is_mode_64() ^ sizePrefixPresent)
687                 {
688                     return u32;
689                 }
690                 else
691                 {
692                     return u16;
693                 }
694                 break;
695             case op_y:
696                 if(ia32_is_mode_64())
697                         return u64;
698                 else
699                         return u32;
700                 break;
701             case op_p:
702                 // book says operand size; arch-x86 says word + word * operand size
703                 if(!ia32_is_mode_64() ^ sizePrefixPresent)
704                 {
705                     return u48;
706                 }
707                 else
708                 {
709                     return u32;
710                 }
711             case op_dq:
712                 return u64;
713             case op_512:
714                 return m512;
715             case op_pi:
716             case op_ps:
717             case op_pd:
718                 return dbl128;
719             case op_s:
720                 return u48;
721             case op_f:
722                 return sp_float;
723             case op_dbl:
724                 return dp_float;
725             case op_14:
726                 return m14;
727             default:
728                 assert(!"Can't happen!");
729                 return u8;
730         }
731     }
732
733
734     bool InstructionDecoder_x86::decodeOneOperand(const InstructionDecoder::buffer& b,
735                                                   const ia32_operand& operand,
736                                                   int & imm_index, /* immediate operand index */
737                                                   const Instruction* insn_to_complete, 
738                                                   bool isRead, bool isWritten)
739     {
740        bool isCFT = false;
741       bool isCall = false;
742       bool isConditional = false;
743       InsnCategory cat = insn_to_complete->getCategory();
744       if(cat == c_BranchInsn || cat == c_CallInsn)
745         {
746           isCFT = true;
747           if(cat == c_CallInsn)
748             {
749               isCall = true;
750             }
751         }
752       if (cat == c_BranchInsn && insn_to_complete->getOperation().getID() != e_jmp) {
753         isConditional = true;
754       }
755
756       unsigned int optype = operand.optype;
757       if (sizePrefixPresent && 
758           ((optype == op_v) ||
759            (optype == op_z))) {
760         optype = op_w;
761       }
762       if(optype == op_y) {
763           if(ia32_is_mode_64() && locs->rex_w)
764                   optype = op_q;
765           else
766                   optype = op_d;
767       }
768                 switch(operand.admet)
769                 {
770                     case 0:
771                     // No operand
772                     {
773 /*                        fprintf(stderr, "ERROR: Instruction with mismatched operands. Raw bytes: ");
774                         for(unsigned int i = 0; i < decodedInstruction->getSize(); i++) {
775                             fprintf(stderr, "%x ", b.start[i]);
776                         }
777                         fprintf(stderr, "\n");*/
778                         assert(!"Mismatched number of operands--check tables");
779                         return false;
780                     }
781                     case am_A:
782                     {
783                         // am_A only shows up as a far call/jump.  Position 1 should be universally safe.
784                         Expression::Ptr addr(decodeImmediate(optype, b.start + 1));
785                         insn_to_complete->addSuccessor(addr, isCall, false, false, false);
786                     }
787                     break;
788                     case am_C:
789                     {
790                         Expression::Ptr op(makeRegisterExpression(IntelRegTable(m_Arch,b_cr,locs->modrm_reg)));
791                         insn_to_complete->appendOperand(op, isRead, isWritten);
792                     }
793                     break;
794                     case am_D:
795                     {
796                         Expression::Ptr op(makeRegisterExpression(IntelRegTable(m_Arch,b_dr,locs->modrm_reg)));
797                         insn_to_complete->appendOperand(op, isRead, isWritten);
798                     }
799                     break;
800                     case am_E:
801                     // am_M is like am_E, except that mod of 0x03 should never occur (am_M specified memory,
802                     // mod of 0x03 specifies direct register access).
803                     case am_M:
804                     // am_R is the inverse of am_M; it should only have a mod of 3
805                     case am_R:
806                     // can be am_R or am_M      
807                     case am_RM: 
808                         if(isCFT)
809                         {
810                           insn_to_complete->addSuccessor(makeModRMExpression(b, optype), isCall, true, false, false);
811                         }
812                         else
813                         {
814                           insn_to_complete->appendOperand(makeModRMExpression(b, optype), isRead, isWritten);
815                         }
816                     break;
817                     case am_F:
818                     {
819                         Expression::Ptr op(makeRegisterExpression(x86::flags));
820                         insn_to_complete->appendOperand(op, isRead, isWritten);
821                     }
822                     break;
823                     case am_G:
824                     {
825                         Expression::Ptr op(makeRegisterExpression(makeRegisterID(locs->modrm_reg,
826                                 optype, locs->rex_r)));
827                         insn_to_complete->appendOperand(op, isRead, isWritten);
828                     }
829                     break;
830                     case am_I:
831                         insn_to_complete->appendOperand(decodeImmediate(optype, b.start + 
832                                                                         locs->imm_position[imm_index++]), 
833                                                         isRead, isWritten);
834                         break;
835                     case am_J:
836                     {
837                         Expression::Ptr Offset(decodeImmediate(optype, 
838                                                                b.start + locs->imm_position[imm_index++], 
839                                                                true));
840                         Expression::Ptr EIP(makeRegisterExpression(MachRegister::getPC(m_Arch)));
841                         Expression::Ptr InsnSize(make_shared(singleton_object_pool<Immediate>::construct(Result(u8,
842                             decodedInstruction->getSize()))));
843                         Expression::Ptr postEIP(makeAddExpression(EIP, InsnSize, u32));
844
845                         Expression::Ptr op(makeAddExpression(Offset, postEIP, u32));
846                         insn_to_complete->addSuccessor(op, isCall, false, isConditional, false);
847                         if (isConditional) 
848                           insn_to_complete->addSuccessor(postEIP, false, false, true, true);
849                     }
850                     break;
851                     case am_O:
852                     {
853                     // Address/offset width, which is *not* what's encoded by the optype...
854                     // The deref's width is what's actually encoded here.
855                         int pseudoOpType;
856                         switch(locs->address_size)
857                         {
858                             case 1:
859                                 pseudoOpType = op_b;
860                                 break;
861                             case 2:
862                                 pseudoOpType = op_w;
863                                 break;
864                             case 4:
865                                 pseudoOpType = op_d;
866                                 break;
867                             case 0:
868                                 // closest I can get to "will be address size by default"
869                                 pseudoOpType = op_v;
870                                 break;
871                             default:
872                                 assert(!"Bad address size, should be 0, 1, 2, or 4!");
873                                 pseudoOpType = op_b;
874                                 break;
875                         }
876
877
878                         int offset_position = locs->opcode_position;
879                         if(locs->modrm_position > offset_position && locs->modrm_operand <
880                            (int)(insn_to_complete->m_Operands.size()))
881                         {
882                             offset_position = locs->modrm_position;
883                         }
884                         if(locs->sib_position > offset_position)
885                         {
886                             offset_position = locs->sib_position;
887                         }
888                         offset_position++;
889                         insn_to_complete->appendOperand(makeDereferenceExpression(
890                                 decodeImmediate(pseudoOpType, b.start + offset_position), makeSizeType(optype)), 
891                                                         isRead, isWritten);
892                     }
893                     break;
894                     case am_P:
895                         insn_to_complete->appendOperand(makeRegisterExpression(IntelRegTable(m_Arch,b_mm,locs->modrm_reg)),
896                                 isRead, isWritten);
897                         break;
898                     case am_Q:
899         
900                         switch(locs->modrm_mod)
901                         {
902                             // direct dereference
903                             case 0x00:
904                             case 0x01:
905                             case 0x02:
906                               insn_to_complete->appendOperand(makeModRMExpression(b, optype), isRead, isWritten);
907                                 break;
908                             case 0x03:
909                                 // use of actual register
910                                 insn_to_complete->appendOperand(makeRegisterExpression(IntelRegTable(m_Arch,b_mm,locs->modrm_rm)),
911                                                                isRead, isWritten);
912                                 break;
913                             default:
914                                 assert(!"2-bit value modrm_mod out of range");
915                                 break;
916                         };
917                         break;
918                     case am_S:
919                     // Segment register in modrm reg field.
920                         insn_to_complete->appendOperand(makeRegisterExpression(IntelRegTable(m_Arch,b_segment,locs->modrm_reg)),
921                                 isRead, isWritten);
922                         break;
923                     case am_T:
924                         // test register in modrm reg; should only be tr6/tr7, but we'll decode any of them
925                         // NOTE: this only appears in deprecated opcodes
926                         insn_to_complete->appendOperand(makeRegisterExpression(IntelRegTable(m_Arch,b_tr,locs->modrm_reg)),
927                                                        isRead, isWritten);
928                         break;
929                     case am_UM:
930                         switch(locs->modrm_mod)
931                         {
932                         // direct dereference
933                         case 0x00:
934                         case 0x01:
935                         case 0x02:
936                                 insn_to_complete->appendOperand(makeModRMExpression(b, makeSizeType(optype)),
937                                                 isRead, isWritten);
938                                 break;
939                         case 0x03:
940                                 // use of actual register
941                                 {
942                                         insn_to_complete->appendOperand(makeRegisterExpression(IntelRegTable(m_Arch,
943                                                         (locs->rex_b == 1) ? b_xmmhigh : b_xmm, locs->modrm_rm)),
944                                                         isRead, isWritten);
945                                         break;
946                                 }
947                         default:
948                                 assert(!"2-bit value modrm_mod out of range");
949                                 break;
950                         };
951                         break;
952                     case am_V:
953                        
954                         insn_to_complete->appendOperand(makeRegisterExpression(IntelRegTable(m_Arch,
955                                 (locs->rex_r == 1 )? b_xmmhigh : b_xmm,locs->modrm_reg)),
956                                     isRead, isWritten);
957                         break;
958                     case am_W:
959                         switch(locs->modrm_mod)
960                         {
961                             // direct dereference
962                             case 0x00:
963                             case 0x01:
964                             case 0x02:
965                               insn_to_complete->appendOperand(makeModRMExpression(b, makeSizeType(optype)),
966                                                                isRead, isWritten);
967                                 break;
968                             case 0x03:
969                             // use of actual register
970                             {
971                                 insn_to_complete->appendOperand(makeRegisterExpression(IntelRegTable(m_Arch,
972                                         (locs->rex_b == 1) ? b_xmmhigh : b_xmm, locs->modrm_rm)),
973                                         isRead, isWritten);
974                                 break;
975                             }
976                             default:
977                                 assert(!"2-bit value modrm_mod out of range");
978                                 break;
979                         };
980                         break;
981                     case am_X:
982                     {
983                         MachRegister si_reg;
984                         if(m_Arch == Arch_x86)
985                         {
986                                 if(addrSizePrefixPresent)
987                                 {
988                                         si_reg = x86::si;
989                                 } else
990                                 {
991                                         si_reg = x86::esi;
992                                 }
993                         }
994                         else
995                         {
996                                 if(addrSizePrefixPresent)
997                                 {
998                                         si_reg = x86_64::esi;
999                                 } else
1000                                 {
1001                                         si_reg = x86_64::rsi;
1002                                 }
1003                         }
1004                         Expression::Ptr ds(makeRegisterExpression(m_Arch == Arch_x86 ? x86::ds : x86_64::ds));
1005                         Expression::Ptr si(makeRegisterExpression(si_reg));
1006                         Expression::Ptr segmentOffset(make_shared(singleton_object_pool<Immediate>::construct(
1007                                 Result(u32, 0x10))));
1008                         Expression::Ptr ds_segment = makeMultiplyExpression(ds, segmentOffset, u32);
1009                         Expression::Ptr ds_si = makeAddExpression(ds_segment, si, u32);
1010                         insn_to_complete->appendOperand(makeDereferenceExpression(ds_si, makeSizeType(optype)),
1011                                                        isRead, isWritten);
1012                     }
1013                     break;
1014                     case am_Y:
1015                     {
1016                         MachRegister di_reg;
1017                         if(m_Arch == Arch_x86)
1018                         {
1019                                 if(addrSizePrefixPresent)
1020                                 {
1021                                         di_reg = x86::di;
1022                                 } else
1023                                 {
1024                                         di_reg = x86::edi;
1025                                 }
1026                         }
1027                         else
1028                         {
1029                                 if(addrSizePrefixPresent)
1030                                 {
1031                                         di_reg = x86_64::edi;
1032                                 } else
1033                                 {
1034                                         di_reg = x86_64::rdi;
1035                                 }
1036                         }
1037                         Expression::Ptr es(makeRegisterExpression(m_Arch == Arch_x86 ? x86::es : x86_64::es));
1038                         Expression::Ptr di(makeRegisterExpression(di_reg));
1039                         Expression::Ptr es_segment = makeMultiplyExpression(es,
1040                             make_shared(singleton_object_pool<Immediate>::construct(Result(u32, 0x10))), u32);
1041                         Expression::Ptr es_di = makeAddExpression(es_segment, di, u32);
1042                         insn_to_complete->appendOperand(makeDereferenceExpression(es_di, makeSizeType(optype)),
1043                                                        isRead, isWritten);
1044                     }
1045                     break;
1046                     case am_tworeghack:
1047                     {
1048                         if(optype == op_edxeax)
1049                         {
1050                             Expression::Ptr edx(makeRegisterExpression(m_Arch == Arch_x86 ? x86::edx : x86_64::edx));
1051                             Expression::Ptr eax(makeRegisterExpression(m_Arch == Arch_x86 ? x86::eax : x86_64::eax));
1052                             Expression::Ptr highAddr = makeMultiplyExpression(edx,
1053                                     Immediate::makeImmediate(Result(u64, 2^32)), u64);
1054                             Expression::Ptr addr = makeAddExpression(highAddr, eax, u64);
1055                             Expression::Ptr op = makeDereferenceExpression(addr, u64);
1056                             insn_to_complete->appendOperand(op, isRead, isWritten);
1057                         }
1058                         else if (optype == op_ecxebx)
1059                         {
1060                             Expression::Ptr ecx(makeRegisterExpression(m_Arch == Arch_x86 ? x86::ecx : x86_64::ecx));
1061                             Expression::Ptr ebx(makeRegisterExpression(m_Arch == Arch_x86 ? x86::ebx : x86_64::ebx));
1062                             Expression::Ptr highAddr = makeMultiplyExpression(ecx,
1063                                     Immediate::makeImmediate(Result(u64, 2^32)), u64);
1064                             Expression::Ptr addr = makeAddExpression(highAddr, ebx, u64);
1065                             Expression::Ptr op = makeDereferenceExpression(addr, u64);
1066                             insn_to_complete->appendOperand(op, isRead, isWritten);
1067                         }
1068                     }
1069                     break;
1070                     
1071                     case am_reg:
1072                     {
1073                         MachRegister r(optype);
1074                         r = MachRegister((r.val() & ~r.getArchitecture()) | m_Arch);
1075                         entryID entryid = decodedInstruction->getEntry()->getID(locs);
1076                         if(locs->rex_b && insn_to_complete->m_Operands.empty() && 
1077                             (entryid == e_push || entryid == e_pop || entryid == e_xchg || ((*(b.start + locs->opcode_position) & 0xf0) == 0xb0) ) )
1078                         {
1079                             // FP stack registers are not affected by the rex_b bit in AM_REG.
1080                            if(r.regClass() != (unsigned) x86::MMX)
1081                             {
1082                                 r = MachRegister((r.val()) | x86_64::r8.val());
1083                             }
1084                         }
1085                         if(sizePrefixPresent)
1086                         {
1087                             r = MachRegister((r.val() & ~x86::FULL) | x86::W_REG);
1088                         }
1089                         Expression::Ptr op(makeRegisterExpression(r));
1090                         insn_to_complete->appendOperand(op, isRead, isWritten);
1091                     }
1092                     break;
1093                 case am_stackH:
1094                 case am_stackP:
1095                 // handled elsewhere
1096                     break;
1097                 case am_allgprs:
1098                 {
1099                     if(m_Arch == Arch_x86)
1100                     {
1101                         insn_to_complete->appendOperand(makeRegisterExpression(x86::eax), isRead, isWritten);
1102                         insn_to_complete->appendOperand(makeRegisterExpression(x86::ecx), isRead, isWritten);
1103                         insn_to_complete->appendOperand(makeRegisterExpression(x86::edx), isRead, isWritten);
1104                         insn_to_complete->appendOperand(makeRegisterExpression(x86::ebx), isRead, isWritten);
1105                         insn_to_complete->appendOperand(makeRegisterExpression(x86::esp), isRead, isWritten);
1106                         insn_to_complete->appendOperand(makeRegisterExpression(x86::ebp), isRead, isWritten);
1107                         insn_to_complete->appendOperand(makeRegisterExpression(x86::esi), isRead, isWritten);
1108                         insn_to_complete->appendOperand(makeRegisterExpression(x86::edi), isRead, isWritten);
1109                     }
1110                     else
1111                     {
1112                         insn_to_complete->appendOperand(makeRegisterExpression(x86_64::eax), isRead, isWritten);
1113                         insn_to_complete->appendOperand(makeRegisterExpression(x86_64::ecx), isRead, isWritten);
1114                         insn_to_complete->appendOperand(makeRegisterExpression(x86_64::edx), isRead, isWritten);
1115                         insn_to_complete->appendOperand(makeRegisterExpression(x86_64::ebx), isRead, isWritten);
1116                         insn_to_complete->appendOperand(makeRegisterExpression(x86_64::esp), isRead, isWritten);
1117                         insn_to_complete->appendOperand(makeRegisterExpression(x86_64::ebp), isRead, isWritten);
1118                         insn_to_complete->appendOperand(makeRegisterExpression(x86_64::esi), isRead, isWritten);
1119                         insn_to_complete->appendOperand(makeRegisterExpression(x86_64::edi), isRead, isWritten);
1120                     }
1121                 }
1122                     break;
1123                 case am_ImplImm: {
1124                   insn_to_complete->appendOperand(Immediate::makeImmediate(Result(makeSizeType(optype), 1)), isRead, isWritten);
1125                   break;
1126                 }
1127
1128                 default:
1129                     printf("decodeOneOperand() called with unknown addressing method %d\n", operand.admet);
1130                         break;
1131                 };
1132                 return true;
1133             }
1134
1135     extern ia32_entry invalid;
1136     
1137     void InstructionDecoder_x86::doIA32Decode(InstructionDecoder::buffer& b)
1138     {
1139         if(decodedInstruction == NULL)
1140         {
1141             decodedInstruction = reinterpret_cast<ia32_instruction*>(malloc(sizeof(ia32_instruction)));
1142             assert(decodedInstruction);
1143         }
1144         if(locs == NULL)
1145         {
1146             locs = reinterpret_cast<ia32_locations*>(malloc(sizeof(ia32_locations)));
1147             assert(locs);
1148         }
1149         locs = new(locs) ia32_locations; //reinit();
1150         assert(locs->sib_position == -1);
1151         decodedInstruction = new (decodedInstruction) ia32_instruction(NULL, NULL, locs);
1152         ia32_decode(IA32_DECODE_PREFIXES, b.start, *decodedInstruction);
1153         sizePrefixPresent = (decodedInstruction->getPrefix()->getOperSzPrefix() == 0x66);
1154         if (decodedInstruction->getPrefix()->rexW()) {
1155            // as per 2.2.1.2 - rex.w overrides 66h
1156            sizePrefixPresent = false;
1157         }
1158         addrSizePrefixPresent = (decodedInstruction->getPrefix()->getAddrSzPrefix() == 0x67);
1159     }
1160     
1161     void InstructionDecoder_x86::decodeOpcode(InstructionDecoder::buffer& b)
1162     {
1163         static ia32_entry invalid = { e_No_Entry, 0, 0, true, { {0,0}, {0,0}, {0,0} }, 0, 0 };
1164         doIA32Decode(b);
1165         if(decodedInstruction->getEntry()) {
1166             m_Operation = make_shared(singleton_object_pool<Operation>::construct(decodedInstruction->getEntry(),
1167                                     decodedInstruction->getPrefix(), locs, m_Arch));
1168             
1169         }
1170         else
1171         {
1172                 // Gap parsing can trigger this case; in particular, when it encounters prefixes in an invalid order.
1173                 // Notably, if a REX prefix (0x40-0x48) appears followed by another prefix (0x66, 0x67, etc)
1174                 // we'll reject the instruction as invalid and send it back with no entry.  Since this is a common
1175                 // byte sequence to see in, for example, ASCII strings, we want to simply accept this and move on, not
1176                 // yell at the user.
1177             m_Operation = make_shared(singleton_object_pool<Operation>::construct(&invalid,
1178                                     decodedInstruction->getPrefix(), locs, m_Arch));
1179         }
1180         b.start += decodedInstruction->getSize();
1181     }
1182     
1183       bool InstructionDecoder_x86::decodeOperands(const Instruction* insn_to_complete)
1184     {
1185        int imm_index = 0; // handle multiple immediate operands
1186         if(!decodedInstruction) return false;
1187         unsigned int opsema = decodedInstruction->getEntry()->opsema & 0xFF;
1188         InstructionDecoder::buffer b(insn_to_complete->ptr(), insn_to_complete->size());
1189
1190         if (decodedInstruction->getEntry()->getID() == e_ret_near ||
1191             decodedInstruction->getEntry()->getID() == e_ret_far) {
1192            Expression::Ptr ret_addr = makeDereferenceExpression(makeRegisterExpression(ia32_is_mode_64() ? x86_64::rsp : x86::esp), 
1193                                                                 ia32_is_mode_64() ? u64 : u32);
1194            insn_to_complete->addSuccessor(ret_addr, false, true, false, false);
1195         }
1196
1197         for(unsigned i = 0; i < 3; i++)
1198         {
1199             if(decodedInstruction->getEntry()->operands[i].admet == 0 && 
1200                decodedInstruction->getEntry()->operands[i].optype == 0)
1201                 return true;
1202             if(!decodeOneOperand(b,
1203                                  decodedInstruction->getEntry()->operands[i], 
1204                                  imm_index, 
1205                                  insn_to_complete, 
1206                                  readsOperand(opsema, i),
1207                                  writesOperand(opsema, i)))
1208             {
1209                 return false;
1210             }
1211         }
1212     
1213         return true;
1214     }
1215
1216     
1217       INSTRUCTION_EXPORT Instruction::Ptr InstructionDecoder_x86::decode(InstructionDecoder::buffer& b)
1218     {
1219         return InstructionDecoderImpl::decode(b);
1220     }
1221     void InstructionDecoder_x86::doDelayedDecode(const Instruction* insn_to_complete)
1222     {
1223       InstructionDecoder::buffer b(insn_to_complete->ptr(), insn_to_complete->size());
1224       //insn_to_complete->m_Operands.reserve(4);
1225       doIA32Decode(b);        
1226       decodeOperands(insn_to_complete);
1227     }
1228     
1229 };
1230 };
1231