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1 //===------ PPCDisassembler.cpp - Disassembler for PowerPC ------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "PPC.h"
11 #include "llvm/MC/MCDisassembler.h"
12 #include "llvm/MC/MCFixedLenDisassembler.h"
13 #include "llvm/MC/MCInst.h"
14 #include "llvm/MC/MCSubtargetInfo.h"
15 #include "llvm/Support/MemoryObject.h"
16 #include "llvm/Support/TargetRegistry.h"
17 
18 using namespace llvm;
19 
20 #define DEBUG_TYPE "ppc-disassembler"
21 
22 typedef MCDisassembler::DecodeStatus DecodeStatus;
23 
24 namespace {
25 class PPCDisassembler : public MCDisassembler {
26 public:
PPCDisassembler(const MCSubtargetInfo & STI,MCContext & Ctx)27   PPCDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
28     : MCDisassembler(STI, Ctx) {}
~PPCDisassembler()29   virtual ~PPCDisassembler() {}
30 
31   // Override MCDisassembler.
32   virtual DecodeStatus getInstruction(MCInst &instr,
33                                       uint64_t &size,
34                                       const MemoryObject &region,
35                                       uint64_t address,
36                                       raw_ostream &vStream,
37                                       raw_ostream &cStream) const override;
38 };
39 } // end anonymous namespace
40 
createPPCDisassembler(const Target & T,const MCSubtargetInfo & STI,MCContext & Ctx)41 static MCDisassembler *createPPCDisassembler(const Target &T,
42                                              const MCSubtargetInfo &STI,
43                                              MCContext &Ctx) {
44   return new PPCDisassembler(STI, Ctx);
45 }
46 
LLVMInitializePowerPCDisassembler()47 extern "C" void LLVMInitializePowerPCDisassembler() {
48   // Register the disassembler for each target.
49   TargetRegistry::RegisterMCDisassembler(ThePPC32Target,
50                                          createPPCDisassembler);
51   TargetRegistry::RegisterMCDisassembler(ThePPC64Target,
52                                          createPPCDisassembler);
53   TargetRegistry::RegisterMCDisassembler(ThePPC64LETarget,
54                                          createPPCDisassembler);
55 }
56 
57 // FIXME: These can be generated by TableGen from the existing register
58 // encoding values!
59 
60 static const unsigned CRRegs[] = {
61   PPC::CR0, PPC::CR1, PPC::CR2, PPC::CR3,
62   PPC::CR4, PPC::CR5, PPC::CR6, PPC::CR7
63 };
64 
65 static const unsigned CRBITRegs[] = {
66   PPC::CR0LT, PPC::CR0GT, PPC::CR0EQ, PPC::CR0UN,
67   PPC::CR1LT, PPC::CR1GT, PPC::CR1EQ, PPC::CR1UN,
68   PPC::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN,
69   PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN,
70   PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN,
71   PPC::CR5LT, PPC::CR5GT, PPC::CR5EQ, PPC::CR5UN,
72   PPC::CR6LT, PPC::CR6GT, PPC::CR6EQ, PPC::CR6UN,
73   PPC::CR7LT, PPC::CR7GT, PPC::CR7EQ, PPC::CR7UN
74 };
75 
76 static const unsigned FRegs[] = {
77   PPC::F0, PPC::F1, PPC::F2, PPC::F3,
78   PPC::F4, PPC::F5, PPC::F6, PPC::F7,
79   PPC::F8, PPC::F9, PPC::F10, PPC::F11,
80   PPC::F12, PPC::F13, PPC::F14, PPC::F15,
81   PPC::F16, PPC::F17, PPC::F18, PPC::F19,
82   PPC::F20, PPC::F21, PPC::F22, PPC::F23,
83   PPC::F24, PPC::F25, PPC::F26, PPC::F27,
84   PPC::F28, PPC::F29, PPC::F30, PPC::F31
85 };
86 
87 static const unsigned VRegs[] = {
88   PPC::V0, PPC::V1, PPC::V2, PPC::V3,
89   PPC::V4, PPC::V5, PPC::V6, PPC::V7,
90   PPC::V8, PPC::V9, PPC::V10, PPC::V11,
91   PPC::V12, PPC::V13, PPC::V14, PPC::V15,
92   PPC::V16, PPC::V17, PPC::V18, PPC::V19,
93   PPC::V20, PPC::V21, PPC::V22, PPC::V23,
94   PPC::V24, PPC::V25, PPC::V26, PPC::V27,
95   PPC::V28, PPC::V29, PPC::V30, PPC::V31
96 };
97 
98 static const unsigned VSRegs[] = {
99   PPC::VSL0, PPC::VSL1, PPC::VSL2, PPC::VSL3,
100   PPC::VSL4, PPC::VSL5, PPC::VSL6, PPC::VSL7,
101   PPC::VSL8, PPC::VSL9, PPC::VSL10, PPC::VSL11,
102   PPC::VSL12, PPC::VSL13, PPC::VSL14, PPC::VSL15,
103   PPC::VSL16, PPC::VSL17, PPC::VSL18, PPC::VSL19,
104   PPC::VSL20, PPC::VSL21, PPC::VSL22, PPC::VSL23,
105   PPC::VSL24, PPC::VSL25, PPC::VSL26, PPC::VSL27,
106   PPC::VSL28, PPC::VSL29, PPC::VSL30, PPC::VSL31,
107 
108   PPC::VSH0, PPC::VSH1, PPC::VSH2, PPC::VSH3,
109   PPC::VSH4, PPC::VSH5, PPC::VSH6, PPC::VSH7,
110   PPC::VSH8, PPC::VSH9, PPC::VSH10, PPC::VSH11,
111   PPC::VSH12, PPC::VSH13, PPC::VSH14, PPC::VSH15,
112   PPC::VSH16, PPC::VSH17, PPC::VSH18, PPC::VSH19,
113   PPC::VSH20, PPC::VSH21, PPC::VSH22, PPC::VSH23,
114   PPC::VSH24, PPC::VSH25, PPC::VSH26, PPC::VSH27,
115   PPC::VSH28, PPC::VSH29, PPC::VSH30, PPC::VSH31
116 };
117 
118 static const unsigned VSFRegs[] = {
119   PPC::F0, PPC::F1, PPC::F2, PPC::F3,
120   PPC::F4, PPC::F5, PPC::F6, PPC::F7,
121   PPC::F8, PPC::F9, PPC::F10, PPC::F11,
122   PPC::F12, PPC::F13, PPC::F14, PPC::F15,
123   PPC::F16, PPC::F17, PPC::F18, PPC::F19,
124   PPC::F20, PPC::F21, PPC::F22, PPC::F23,
125   PPC::F24, PPC::F25, PPC::F26, PPC::F27,
126   PPC::F28, PPC::F29, PPC::F30, PPC::F31,
127 
128   PPC::VF0, PPC::VF1, PPC::VF2, PPC::VF3,
129   PPC::VF4, PPC::VF5, PPC::VF6, PPC::VF7,
130   PPC::VF8, PPC::VF9, PPC::VF10, PPC::VF11,
131   PPC::VF12, PPC::VF13, PPC::VF14, PPC::VF15,
132   PPC::VF16, PPC::VF17, PPC::VF18, PPC::VF19,
133   PPC::VF20, PPC::VF21, PPC::VF22, PPC::VF23,
134   PPC::VF24, PPC::VF25, PPC::VF26, PPC::VF27,
135   PPC::VF28, PPC::VF29, PPC::VF30, PPC::VF31
136 };
137 
138 static const unsigned GPRegs[] = {
139   PPC::R0, PPC::R1, PPC::R2, PPC::R3,
140   PPC::R4, PPC::R5, PPC::R6, PPC::R7,
141   PPC::R8, PPC::R9, PPC::R10, PPC::R11,
142   PPC::R12, PPC::R13, PPC::R14, PPC::R15,
143   PPC::R16, PPC::R17, PPC::R18, PPC::R19,
144   PPC::R20, PPC::R21, PPC::R22, PPC::R23,
145   PPC::R24, PPC::R25, PPC::R26, PPC::R27,
146   PPC::R28, PPC::R29, PPC::R30, PPC::R31
147 };
148 
149 static const unsigned GP0Regs[] = {
150   PPC::ZERO, PPC::R1, PPC::R2, PPC::R3,
151   PPC::R4, PPC::R5, PPC::R6, PPC::R7,
152   PPC::R8, PPC::R9, PPC::R10, PPC::R11,
153   PPC::R12, PPC::R13, PPC::R14, PPC::R15,
154   PPC::R16, PPC::R17, PPC::R18, PPC::R19,
155   PPC::R20, PPC::R21, PPC::R22, PPC::R23,
156   PPC::R24, PPC::R25, PPC::R26, PPC::R27,
157   PPC::R28, PPC::R29, PPC::R30, PPC::R31
158 };
159 
160 static const unsigned G8Regs[] = {
161   PPC::X0, PPC::X1, PPC::X2, PPC::X3,
162   PPC::X4, PPC::X5, PPC::X6, PPC::X7,
163   PPC::X8, PPC::X9, PPC::X10, PPC::X11,
164   PPC::X12, PPC::X13, PPC::X14, PPC::X15,
165   PPC::X16, PPC::X17, PPC::X18, PPC::X19,
166   PPC::X20, PPC::X21, PPC::X22, PPC::X23,
167   PPC::X24, PPC::X25, PPC::X26, PPC::X27,
168   PPC::X28, PPC::X29, PPC::X30, PPC::X31
169 };
170 
171 template <std::size_t N>
decodeRegisterClass(MCInst & Inst,uint64_t RegNo,const unsigned (& Regs)[N])172 static DecodeStatus decodeRegisterClass(MCInst &Inst, uint64_t RegNo,
173                                         const unsigned (&Regs)[N]) {
174   assert(RegNo < N && "Invalid register number");
175   Inst.addOperand(MCOperand::CreateReg(Regs[RegNo]));
176   return MCDisassembler::Success;
177 }
178 
DecodeCRRCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)179 static DecodeStatus DecodeCRRCRegisterClass(MCInst &Inst, uint64_t RegNo,
180                                             uint64_t Address,
181                                             const void *Decoder) {
182   return decodeRegisterClass(Inst, RegNo, CRRegs);
183 }
184 
DecodeCRBITRCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)185 static DecodeStatus DecodeCRBITRCRegisterClass(MCInst &Inst, uint64_t RegNo,
186                                             uint64_t Address,
187                                             const void *Decoder) {
188   return decodeRegisterClass(Inst, RegNo, CRBITRegs);
189 }
190 
DecodeF4RCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)191 static DecodeStatus DecodeF4RCRegisterClass(MCInst &Inst, uint64_t RegNo,
192                                             uint64_t Address,
193                                             const void *Decoder) {
194   return decodeRegisterClass(Inst, RegNo, FRegs);
195 }
196 
DecodeF8RCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)197 static DecodeStatus DecodeF8RCRegisterClass(MCInst &Inst, uint64_t RegNo,
198                                             uint64_t Address,
199                                             const void *Decoder) {
200   return decodeRegisterClass(Inst, RegNo, FRegs);
201 }
202 
DecodeVRRCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)203 static DecodeStatus DecodeVRRCRegisterClass(MCInst &Inst, uint64_t RegNo,
204                                             uint64_t Address,
205                                             const void *Decoder) {
206   return decodeRegisterClass(Inst, RegNo, VRegs);
207 }
208 
DecodeVSRCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)209 static DecodeStatus DecodeVSRCRegisterClass(MCInst &Inst, uint64_t RegNo,
210                                             uint64_t Address,
211                                             const void *Decoder) {
212   return decodeRegisterClass(Inst, RegNo, VSRegs);
213 }
214 
DecodeVSFRCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)215 static DecodeStatus DecodeVSFRCRegisterClass(MCInst &Inst, uint64_t RegNo,
216                                             uint64_t Address,
217                                             const void *Decoder) {
218   return decodeRegisterClass(Inst, RegNo, VSFRegs);
219 }
220 
DecodeGPRCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)221 static DecodeStatus DecodeGPRCRegisterClass(MCInst &Inst, uint64_t RegNo,
222                                             uint64_t Address,
223                                             const void *Decoder) {
224   return decodeRegisterClass(Inst, RegNo, GPRegs);
225 }
226 
DecodeGPRC_NOR0RegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)227 static DecodeStatus DecodeGPRC_NOR0RegisterClass(MCInst &Inst, uint64_t RegNo,
228                                             uint64_t Address,
229                                             const void *Decoder) {
230   return decodeRegisterClass(Inst, RegNo, GP0Regs);
231 }
232 
DecodeG8RCRegisterClass(MCInst & Inst,uint64_t RegNo,uint64_t Address,const void * Decoder)233 static DecodeStatus DecodeG8RCRegisterClass(MCInst &Inst, uint64_t RegNo,
234                                             uint64_t Address,
235                                             const void *Decoder) {
236   return decodeRegisterClass(Inst, RegNo, G8Regs);
237 }
238 
239 #define DecodePointerLikeRegClass0 DecodeGPRCRegisterClass
240 #define DecodePointerLikeRegClass1 DecodeGPRC_NOR0RegisterClass
241 
242 template<unsigned N>
decodeUImmOperand(MCInst & Inst,uint64_t Imm,int64_t Address,const void * Decoder)243 static DecodeStatus decodeUImmOperand(MCInst &Inst, uint64_t Imm,
244                                       int64_t Address, const void *Decoder) {
245   assert(isUInt<N>(Imm) && "Invalid immediate");
246   Inst.addOperand(MCOperand::CreateImm(Imm));
247   return MCDisassembler::Success;
248 }
249 
250 template<unsigned N>
decodeSImmOperand(MCInst & Inst,uint64_t Imm,int64_t Address,const void * Decoder)251 static DecodeStatus decodeSImmOperand(MCInst &Inst, uint64_t Imm,
252                                       int64_t Address, const void *Decoder) {
253   assert(isUInt<N>(Imm) && "Invalid immediate");
254   Inst.addOperand(MCOperand::CreateImm(SignExtend64<N>(Imm)));
255   return MCDisassembler::Success;
256 }
257 
decodeMemRIOperands(MCInst & Inst,uint64_t Imm,int64_t Address,const void * Decoder)258 static DecodeStatus decodeMemRIOperands(MCInst &Inst, uint64_t Imm,
259                                         int64_t Address, const void *Decoder) {
260   // Decode the memri field (imm, reg), which has the low 16-bits as the
261   // displacement and the next 5 bits as the register #.
262 
263   uint64_t Base = Imm >> 16;
264   uint64_t Disp = Imm & 0xFFFF;
265 
266   assert(Base < 32 && "Invalid base register");
267 
268   switch (Inst.getOpcode()) {
269   default: break;
270   case PPC::LBZU:
271   case PPC::LHAU:
272   case PPC::LHZU:
273   case PPC::LWZU:
274   case PPC::LFSU:
275   case PPC::LFDU:
276     // Add the tied output operand.
277     Inst.addOperand(MCOperand::CreateReg(GP0Regs[Base]));
278     break;
279   case PPC::STBU:
280   case PPC::STHU:
281   case PPC::STWU:
282   case PPC::STFSU:
283   case PPC::STFDU:
284     Inst.insert(Inst.begin(), MCOperand::CreateReg(GP0Regs[Base]));
285     break;
286   }
287 
288   Inst.addOperand(MCOperand::CreateImm(SignExtend64<16>(Disp)));
289   Inst.addOperand(MCOperand::CreateReg(GP0Regs[Base]));
290   return MCDisassembler::Success;
291 }
292 
decodeMemRIXOperands(MCInst & Inst,uint64_t Imm,int64_t Address,const void * Decoder)293 static DecodeStatus decodeMemRIXOperands(MCInst &Inst, uint64_t Imm,
294                                          int64_t Address, const void *Decoder) {
295   // Decode the memrix field (imm, reg), which has the low 14-bits as the
296   // displacement and the next 5 bits as the register #.
297 
298   uint64_t Base = Imm >> 14;
299   uint64_t Disp = Imm & 0x3FFF;
300 
301   assert(Base < 32 && "Invalid base register");
302 
303   if (Inst.getOpcode() == PPC::LDU)
304     // Add the tied output operand.
305     Inst.addOperand(MCOperand::CreateReg(GP0Regs[Base]));
306   else if (Inst.getOpcode() == PPC::STDU)
307     Inst.insert(Inst.begin(), MCOperand::CreateReg(GP0Regs[Base]));
308 
309   Inst.addOperand(MCOperand::CreateImm(SignExtend64<16>(Disp << 2)));
310   Inst.addOperand(MCOperand::CreateReg(GP0Regs[Base]));
311   return MCDisassembler::Success;
312 }
313 
decodeCRBitMOperand(MCInst & Inst,uint64_t Imm,int64_t Address,const void * Decoder)314 static DecodeStatus decodeCRBitMOperand(MCInst &Inst, uint64_t Imm,
315                                         int64_t Address, const void *Decoder) {
316   // The cr bit encoding is 0x80 >> cr_reg_num.
317 
318   unsigned Zeros = countTrailingZeros(Imm);
319   assert(Zeros < 8 && "Invalid CR bit value");
320 
321   Inst.addOperand(MCOperand::CreateReg(CRRegs[7 - Zeros]));
322   return MCDisassembler::Success;
323 }
324 
325 #include "PPCGenDisassemblerTables.inc"
326 
getInstruction(MCInst & MI,uint64_t & Size,const MemoryObject & Region,uint64_t Address,raw_ostream & os,raw_ostream & cs) const327 DecodeStatus PPCDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
328                                                  const MemoryObject &Region,
329                                                  uint64_t Address,
330                                                  raw_ostream &os,
331                                                  raw_ostream &cs) const {
332   // Get the four bytes of the instruction.
333   uint8_t Bytes[4];
334   Size = 4;
335   if (Region.readBytes(Address, Size, Bytes) == -1) {
336     Size = 0;
337     return MCDisassembler::Fail;
338   }
339 
340   // The instruction is big-endian encoded.
341   uint32_t Inst = (Bytes[0] << 24) |
342                   (Bytes[1] << 16) |
343                   (Bytes[2] <<  8) |
344                   (Bytes[3] <<  0);
345 
346   return decodeInstruction(DecoderTable32, MI, Inst, Address, this, STI);
347 }
348 
349