1 //===- VEDisassembler.cpp - Disassembler for VE -----------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is part of the VE Disassembler.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "MCTargetDesc/VEMCTargetDesc.h"
14 #include "TargetInfo/VETargetInfo.h"
15 #include "VE.h"
16 #include "llvm/MC/MCAsmInfo.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
19 #include "llvm/MC/MCFixedLenDisassembler.h"
20 #include "llvm/MC/MCInst.h"
21 #include "llvm/Support/TargetRegistry.h"
22 
23 using namespace llvm;
24 
25 #define DEBUG_TYPE "ve-disassembler"
26 
27 typedef MCDisassembler::DecodeStatus DecodeStatus;
28 
29 namespace {
30 
31 /// A disassembler class for VE.
32 class VEDisassembler : public MCDisassembler {
33 public:
34   VEDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
35       : MCDisassembler(STI, Ctx) {}
36   virtual ~VEDisassembler() {}
37 
38   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
39                               ArrayRef<uint8_t> Bytes, uint64_t Address,
40                               raw_ostream &CStream) const override;
41 };
42 } // namespace
43 
44 static MCDisassembler *createVEDisassembler(const Target &T,
45                                             const MCSubtargetInfo &STI,
46                                             MCContext &Ctx) {
47   return new VEDisassembler(STI, Ctx);
48 }
49 
50 extern "C" void LLVMInitializeVEDisassembler() {
51   // Register the disassembler.
52   TargetRegistry::RegisterMCDisassembler(getTheVETarget(),
53                                          createVEDisassembler);
54 }
55 
56 static const unsigned I32RegDecoderTable[] = {
57     VE::SW0,  VE::SW1,  VE::SW2,  VE::SW3,  VE::SW4,  VE::SW5,  VE::SW6,
58     VE::SW7,  VE::SW8,  VE::SW9,  VE::SW10, VE::SW11, VE::SW12, VE::SW13,
59     VE::SW14, VE::SW15, VE::SW16, VE::SW17, VE::SW18, VE::SW19, VE::SW20,
60     VE::SW21, VE::SW22, VE::SW23, VE::SW24, VE::SW25, VE::SW26, VE::SW27,
61     VE::SW28, VE::SW29, VE::SW30, VE::SW31, VE::SW32, VE::SW33, VE::SW34,
62     VE::SW35, VE::SW36, VE::SW37, VE::SW38, VE::SW39, VE::SW40, VE::SW41,
63     VE::SW42, VE::SW43, VE::SW44, VE::SW45, VE::SW46, VE::SW47, VE::SW48,
64     VE::SW49, VE::SW50, VE::SW51, VE::SW52, VE::SW53, VE::SW54, VE::SW55,
65     VE::SW56, VE::SW57, VE::SW58, VE::SW59, VE::SW60, VE::SW61, VE::SW62,
66     VE::SW63};
67 
68 static const unsigned I64RegDecoderTable[] = {
69     VE::SX0,  VE::SX1,  VE::SX2,  VE::SX3,  VE::SX4,  VE::SX5,  VE::SX6,
70     VE::SX7,  VE::SX8,  VE::SX9,  VE::SX10, VE::SX11, VE::SX12, VE::SX13,
71     VE::SX14, VE::SX15, VE::SX16, VE::SX17, VE::SX18, VE::SX19, VE::SX20,
72     VE::SX21, VE::SX22, VE::SX23, VE::SX24, VE::SX25, VE::SX26, VE::SX27,
73     VE::SX28, VE::SX29, VE::SX30, VE::SX31, VE::SX32, VE::SX33, VE::SX34,
74     VE::SX35, VE::SX36, VE::SX37, VE::SX38, VE::SX39, VE::SX40, VE::SX41,
75     VE::SX42, VE::SX43, VE::SX44, VE::SX45, VE::SX46, VE::SX47, VE::SX48,
76     VE::SX49, VE::SX50, VE::SX51, VE::SX52, VE::SX53, VE::SX54, VE::SX55,
77     VE::SX56, VE::SX57, VE::SX58, VE::SX59, VE::SX60, VE::SX61, VE::SX62,
78     VE::SX63};
79 
80 static const unsigned F32RegDecoderTable[] = {
81     VE::SF0,  VE::SF1,  VE::SF2,  VE::SF3,  VE::SF4,  VE::SF5,  VE::SF6,
82     VE::SF7,  VE::SF8,  VE::SF9,  VE::SF10, VE::SF11, VE::SF12, VE::SF13,
83     VE::SF14, VE::SF15, VE::SF16, VE::SF17, VE::SF18, VE::SF19, VE::SF20,
84     VE::SF21, VE::SF22, VE::SF23, VE::SF24, VE::SF25, VE::SF26, VE::SF27,
85     VE::SF28, VE::SF29, VE::SF30, VE::SF31, VE::SF32, VE::SF33, VE::SF34,
86     VE::SF35, VE::SF36, VE::SF37, VE::SF38, VE::SF39, VE::SF40, VE::SF41,
87     VE::SF42, VE::SF43, VE::SF44, VE::SF45, VE::SF46, VE::SF47, VE::SF48,
88     VE::SF49, VE::SF50, VE::SF51, VE::SF52, VE::SF53, VE::SF54, VE::SF55,
89     VE::SF56, VE::SF57, VE::SF58, VE::SF59, VE::SF60, VE::SF61, VE::SF62,
90     VE::SF63};
91 
92 static const unsigned F128RegDecoderTable[] = {
93     VE::Q0,  VE::Q1,  VE::Q2,  VE::Q3,  VE::Q4,  VE::Q5,  VE::Q6,  VE::Q7,
94     VE::Q8,  VE::Q9,  VE::Q10, VE::Q11, VE::Q12, VE::Q13, VE::Q14, VE::Q15,
95     VE::Q16, VE::Q17, VE::Q18, VE::Q19, VE::Q20, VE::Q21, VE::Q22, VE::Q23,
96     VE::Q24, VE::Q25, VE::Q26, VE::Q27, VE::Q28, VE::Q29, VE::Q30, VE::Q31};
97 
98 static const unsigned MiscRegDecoderTable[] = {
99     VE::USRCC,      VE::PSW,        VE::SAR,        VE::NoRegister,
100     VE::NoRegister, VE::NoRegister, VE::NoRegister, VE::PMMR,
101     VE::PMCR0,      VE::PMCR1,      VE::PMCR2,      VE::PMCR3,
102     VE::NoRegister, VE::NoRegister, VE::NoRegister, VE::NoRegister,
103     VE::PMC0,       VE::PMC1,       VE::PMC2,       VE::PMC3,
104     VE::PMC4,       VE::PMC5,       VE::PMC6,       VE::PMC7,
105     VE::PMC8,       VE::PMC9,       VE::PMC10,      VE::PMC11,
106     VE::PMC12,      VE::PMC13,      VE::PMC14};
107 
108 static DecodeStatus DecodeI32RegisterClass(MCInst &Inst, unsigned RegNo,
109                                            uint64_t Address,
110                                            const void *Decoder) {
111   if (RegNo > 63)
112     return MCDisassembler::Fail;
113   unsigned Reg = I32RegDecoderTable[RegNo];
114   Inst.addOperand(MCOperand::createReg(Reg));
115   return MCDisassembler::Success;
116 }
117 
118 static DecodeStatus DecodeI64RegisterClass(MCInst &Inst, unsigned RegNo,
119                                            uint64_t Address,
120                                            const void *Decoder) {
121   if (RegNo > 63)
122     return MCDisassembler::Fail;
123   unsigned Reg = I64RegDecoderTable[RegNo];
124   Inst.addOperand(MCOperand::createReg(Reg));
125   return MCDisassembler::Success;
126 }
127 
128 static DecodeStatus DecodeF32RegisterClass(MCInst &Inst, unsigned RegNo,
129                                            uint64_t Address,
130                                            const void *Decoder) {
131   if (RegNo > 63)
132     return MCDisassembler::Fail;
133   unsigned Reg = F32RegDecoderTable[RegNo];
134   Inst.addOperand(MCOperand::createReg(Reg));
135   return MCDisassembler::Success;
136 }
137 
138 static DecodeStatus DecodeF128RegisterClass(MCInst &Inst, unsigned RegNo,
139                                             uint64_t Address,
140                                             const void *Decoder) {
141   if (RegNo % 2 || RegNo > 63)
142     return MCDisassembler::Fail;
143   unsigned Reg = F128RegDecoderTable[RegNo / 2];
144   Inst.addOperand(MCOperand::createReg(Reg));
145   return MCDisassembler::Success;
146 }
147 
148 static DecodeStatus DecodeMISCRegisterClass(MCInst &Inst, unsigned RegNo,
149                                             uint64_t Address,
150                                             const void *Decoder) {
151   if (RegNo > 30)
152     return MCDisassembler::Fail;
153   unsigned Reg = MiscRegDecoderTable[RegNo];
154   if (Reg == VE::NoRegister)
155     return MCDisassembler::Fail;
156   Inst.addOperand(MCOperand::createReg(Reg));
157   return MCDisassembler::Success;
158 }
159 
160 static DecodeStatus DecodeASX(MCInst &Inst, uint64_t insn, uint64_t Address,
161                               const void *Decoder);
162 static DecodeStatus DecodeLoadI32(MCInst &Inst, uint64_t insn, uint64_t Address,
163                                   const void *Decoder);
164 static DecodeStatus DecodeStoreI32(MCInst &Inst, uint64_t insn,
165                                    uint64_t Address, const void *Decoder);
166 static DecodeStatus DecodeLoadI64(MCInst &Inst, uint64_t insn, uint64_t Address,
167                                   const void *Decoder);
168 static DecodeStatus DecodeStoreI64(MCInst &Inst, uint64_t insn,
169                                    uint64_t Address, const void *Decoder);
170 static DecodeStatus DecodeLoadF32(MCInst &Inst, uint64_t insn, uint64_t Address,
171                                   const void *Decoder);
172 static DecodeStatus DecodeStoreF32(MCInst &Inst, uint64_t insn,
173                                    uint64_t Address, const void *Decoder);
174 static DecodeStatus DecodeLoadASI64(MCInst &Inst, uint64_t insn,
175                                     uint64_t Address, const void *Decoder);
176 static DecodeStatus DecodeStoreASI64(MCInst &Inst, uint64_t insn,
177                                      uint64_t Address, const void *Decoder);
178 static DecodeStatus DecodeTS1AMI64(MCInst &Inst, uint64_t insn,
179                                    uint64_t Address, const void *Decoder);
180 static DecodeStatus DecodeTS1AMI32(MCInst &Inst, uint64_t insn,
181                                    uint64_t Address, const void *Decoder);
182 static DecodeStatus DecodeCASI64(MCInst &Inst, uint64_t insn, uint64_t Address,
183                                  const void *Decoder);
184 static DecodeStatus DecodeCASI32(MCInst &Inst, uint64_t insn, uint64_t Address,
185                                  const void *Decoder);
186 static DecodeStatus DecodeCall(MCInst &Inst, uint64_t insn, uint64_t Address,
187                                const void *Decoder);
188 static DecodeStatus DecodeSIMM7(MCInst &Inst, uint64_t insn, uint64_t Address,
189                                 const void *Decoder);
190 static DecodeStatus DecodeCCOperand(MCInst &Inst, uint64_t insn,
191                                     uint64_t Address, const void *Decoder);
192 static DecodeStatus DecodeBranchCondition(MCInst &Inst, uint64_t insn,
193                                           uint64_t Address,
194                                           const void *Decoder);
195 static DecodeStatus DecodeBranchConditionAlways(MCInst &Inst, uint64_t insn,
196                                                 uint64_t Address,
197                                                 const void *Decoder);
198 
199 #include "VEGenDisassemblerTables.inc"
200 
201 /// Read four bytes from the ArrayRef and return 32 bit word.
202 static DecodeStatus readInstruction64(ArrayRef<uint8_t> Bytes, uint64_t Address,
203                                       uint64_t &Size, uint64_t &Insn,
204                                       bool IsLittleEndian) {
205   // We want to read exactly 8 Bytes of data.
206   if (Bytes.size() < 8) {
207     Size = 0;
208     return MCDisassembler::Fail;
209   }
210 
211   Insn = IsLittleEndian
212              ? ((uint64_t)Bytes[0] << 0) | ((uint64_t)Bytes[1] << 8) |
213                    ((uint64_t)Bytes[2] << 16) | ((uint64_t)Bytes[3] << 24) |
214                    ((uint64_t)Bytes[4] << 32) | ((uint64_t)Bytes[5] << 40) |
215                    ((uint64_t)Bytes[6] << 48) | ((uint64_t)Bytes[7] << 56)
216              : ((uint64_t)Bytes[7] << 0) | ((uint64_t)Bytes[6] << 8) |
217                    ((uint64_t)Bytes[5] << 16) | ((uint64_t)Bytes[4] << 24) |
218                    ((uint64_t)Bytes[3] << 32) | ((uint64_t)Bytes[2] << 40) |
219                    ((uint64_t)Bytes[1] << 48) | ((uint64_t)Bytes[0] << 56);
220 
221   return MCDisassembler::Success;
222 }
223 
224 DecodeStatus VEDisassembler::getInstruction(MCInst &Instr, uint64_t &Size,
225                                             ArrayRef<uint8_t> Bytes,
226                                             uint64_t Address,
227                                             raw_ostream &CStream) const {
228   uint64_t Insn;
229   bool isLittleEndian = getContext().getAsmInfo()->isLittleEndian();
230   DecodeStatus Result =
231       readInstruction64(Bytes, Address, Size, Insn, isLittleEndian);
232   if (Result == MCDisassembler::Fail)
233     return MCDisassembler::Fail;
234 
235   // Calling the auto-generated decoder function.
236 
237   Result = decodeInstruction(DecoderTableVE64, Instr, Insn, Address, this, STI);
238 
239   if (Result != MCDisassembler::Fail) {
240     Size = 8;
241     return Result;
242   }
243 
244   return MCDisassembler::Fail;
245 }
246 
247 typedef DecodeStatus (*DecodeFunc)(MCInst &MI, unsigned RegNo, uint64_t Address,
248                                    const void *Decoder);
249 
250 static DecodeStatus DecodeASX(MCInst &MI, uint64_t insn, uint64_t Address,
251                               const void *Decoder) {
252   unsigned sy = fieldFromInstruction(insn, 40, 7);
253   bool cy = fieldFromInstruction(insn, 47, 1);
254   unsigned sz = fieldFromInstruction(insn, 32, 7);
255   bool cz = fieldFromInstruction(insn, 39, 1);
256   uint64_t simm32 = SignExtend64<32>(fieldFromInstruction(insn, 0, 32));
257   DecodeStatus status;
258 
259   // Decode sz.
260   if (cz) {
261     status = DecodeI64RegisterClass(MI, sz, Address, Decoder);
262     if (status != MCDisassembler::Success)
263       return status;
264   } else {
265     MI.addOperand(MCOperand::createImm(0));
266   }
267 
268   // Decode sy.
269   if (cy) {
270     status = DecodeI64RegisterClass(MI, sy, Address, Decoder);
271     if (status != MCDisassembler::Success)
272       return status;
273   } else {
274     MI.addOperand(MCOperand::createImm(SignExtend32<7>(sy)));
275   }
276 
277   // Decode simm32.
278   MI.addOperand(MCOperand::createImm(simm32));
279 
280   return MCDisassembler::Success;
281 }
282 
283 static DecodeStatus DecodeAS(MCInst &MI, uint64_t insn, uint64_t Address,
284                              const void *Decoder) {
285   unsigned sz = fieldFromInstruction(insn, 32, 7);
286   bool cz = fieldFromInstruction(insn, 39, 1);
287   uint64_t simm32 = SignExtend64<32>(fieldFromInstruction(insn, 0, 32));
288   DecodeStatus status;
289 
290   // Decode sz.
291   if (cz) {
292     status = DecodeI64RegisterClass(MI, sz, Address, Decoder);
293     if (status != MCDisassembler::Success)
294       return status;
295   } else {
296     MI.addOperand(MCOperand::createImm(0));
297   }
298 
299   // Decode simm32.
300   MI.addOperand(MCOperand::createImm(simm32));
301 
302   return MCDisassembler::Success;
303 }
304 
305 static DecodeStatus DecodeMem(MCInst &MI, uint64_t insn, uint64_t Address,
306                               const void *Decoder, bool isLoad,
307                               DecodeFunc DecodeSX) {
308   unsigned sx = fieldFromInstruction(insn, 48, 7);
309 
310   DecodeStatus status;
311   if (isLoad) {
312     status = DecodeSX(MI, sx, Address, Decoder);
313     if (status != MCDisassembler::Success)
314       return status;
315   }
316 
317   status = DecodeASX(MI, insn, Address, Decoder);
318   if (status != MCDisassembler::Success)
319     return status;
320 
321   if (!isLoad) {
322     status = DecodeSX(MI, sx, Address, Decoder);
323     if (status != MCDisassembler::Success)
324       return status;
325   }
326   return MCDisassembler::Success;
327 }
328 
329 static DecodeStatus DecodeMemAS(MCInst &MI, uint64_t insn, uint64_t Address,
330                                 const void *Decoder, bool isLoad,
331                                 DecodeFunc DecodeSX) {
332   unsigned sx = fieldFromInstruction(insn, 48, 7);
333 
334   DecodeStatus status;
335   if (isLoad) {
336     status = DecodeSX(MI, sx, Address, Decoder);
337     if (status != MCDisassembler::Success)
338       return status;
339   }
340 
341   status = DecodeAS(MI, insn, Address, Decoder);
342   if (status != MCDisassembler::Success)
343     return status;
344 
345   if (!isLoad) {
346     status = DecodeSX(MI, sx, Address, Decoder);
347     if (status != MCDisassembler::Success)
348       return status;
349   }
350   return MCDisassembler::Success;
351 }
352 
353 static DecodeStatus DecodeLoadI32(MCInst &Inst, uint64_t insn, uint64_t Address,
354                                   const void *Decoder) {
355   return DecodeMem(Inst, insn, Address, Decoder, true, DecodeI32RegisterClass);
356 }
357 
358 static DecodeStatus DecodeStoreI32(MCInst &Inst, uint64_t insn,
359                                    uint64_t Address, const void *Decoder) {
360   return DecodeMem(Inst, insn, Address, Decoder, false, DecodeI32RegisterClass);
361 }
362 
363 static DecodeStatus DecodeLoadI64(MCInst &Inst, uint64_t insn, uint64_t Address,
364                                   const void *Decoder) {
365   return DecodeMem(Inst, insn, Address, Decoder, true, DecodeI64RegisterClass);
366 }
367 
368 static DecodeStatus DecodeStoreI64(MCInst &Inst, uint64_t insn,
369                                    uint64_t Address, const void *Decoder) {
370   return DecodeMem(Inst, insn, Address, Decoder, false, DecodeI64RegisterClass);
371 }
372 
373 static DecodeStatus DecodeLoadF32(MCInst &Inst, uint64_t insn, uint64_t Address,
374                                   const void *Decoder) {
375   return DecodeMem(Inst, insn, Address, Decoder, true, DecodeF32RegisterClass);
376 }
377 
378 static DecodeStatus DecodeStoreF32(MCInst &Inst, uint64_t insn,
379                                    uint64_t Address, const void *Decoder) {
380   return DecodeMem(Inst, insn, Address, Decoder, false, DecodeF32RegisterClass);
381 }
382 
383 static DecodeStatus DecodeLoadASI64(MCInst &Inst, uint64_t insn,
384                                     uint64_t Address, const void *Decoder) {
385   return DecodeMemAS(Inst, insn, Address, Decoder, true,
386                      DecodeI64RegisterClass);
387 }
388 
389 static DecodeStatus DecodeStoreASI64(MCInst &Inst, uint64_t insn,
390                                      uint64_t Address, const void *Decoder) {
391   return DecodeMemAS(Inst, insn, Address, Decoder, false,
392                      DecodeI64RegisterClass);
393 }
394 
395 static DecodeStatus DecodeCAS(MCInst &MI, uint64_t insn, uint64_t Address,
396                               const void *Decoder, bool isImmOnly, bool isUImm,
397                               DecodeFunc DecodeSX) {
398   unsigned sx = fieldFromInstruction(insn, 48, 7);
399   bool cy = fieldFromInstruction(insn, 47, 1);
400   unsigned sy = fieldFromInstruction(insn, 40, 7);
401 
402   // Add $sx.
403   DecodeStatus status;
404   status = DecodeSX(MI, sx, Address, Decoder);
405   if (status != MCDisassembler::Success)
406     return status;
407 
408   // Add $disp($sz).
409   status = DecodeAS(MI, insn, Address, Decoder);
410   if (status != MCDisassembler::Success)
411     return status;
412 
413   // Add $sy.
414   if (cy && !isImmOnly) {
415     status = DecodeSX(MI, sy, Address, Decoder);
416     if (status != MCDisassembler::Success)
417       return status;
418   } else {
419     if (isUImm)
420       MI.addOperand(MCOperand::createImm(sy));
421     else
422       MI.addOperand(MCOperand::createImm(SignExtend32<7>(sy)));
423   }
424 
425   // Add $sd.
426   status = DecodeSX(MI, sx, Address, Decoder);
427   if (status != MCDisassembler::Success)
428     return status;
429 
430   return MCDisassembler::Success;
431 }
432 
433 static DecodeStatus DecodeTS1AMI64(MCInst &MI, uint64_t insn, uint64_t Address,
434                                    const void *Decoder) {
435   return DecodeCAS(MI, insn, Address, Decoder, false, true,
436                    DecodeI64RegisterClass);
437 }
438 
439 static DecodeStatus DecodeTS1AMI32(MCInst &MI, uint64_t insn, uint64_t Address,
440                                    const void *Decoder) {
441   return DecodeCAS(MI, insn, Address, Decoder, false, true,
442                    DecodeI32RegisterClass);
443 }
444 
445 static DecodeStatus DecodeCASI64(MCInst &MI, uint64_t insn, uint64_t Address,
446                                  const void *Decoder) {
447   return DecodeCAS(MI, insn, Address, Decoder, false, false,
448                    DecodeI64RegisterClass);
449 }
450 
451 static DecodeStatus DecodeCASI32(MCInst &MI, uint64_t insn, uint64_t Address,
452                                  const void *Decoder) {
453   return DecodeCAS(MI, insn, Address, Decoder, false, false,
454                    DecodeI32RegisterClass);
455 }
456 
457 static DecodeStatus DecodeCall(MCInst &Inst, uint64_t insn, uint64_t Address,
458                                const void *Decoder) {
459   return DecodeMem(Inst, insn, Address, Decoder, true, DecodeI64RegisterClass);
460 }
461 
462 static DecodeStatus DecodeSIMM7(MCInst &MI, uint64_t insn, uint64_t Address,
463                                 const void *Decoder) {
464   uint64_t tgt = SignExtend64<7>(insn);
465   MI.addOperand(MCOperand::createImm(tgt));
466   return MCDisassembler::Success;
467 }
468 
469 static bool isIntegerBCKind(MCInst &MI) {
470 
471 #define BCm_kind(NAME)                                                         \
472   case NAME##rri:                                                              \
473   case NAME##rzi:                                                              \
474   case NAME##iri:                                                              \
475   case NAME##izi:                                                              \
476   case NAME##rri_nt:                                                           \
477   case NAME##rzi_nt:                                                           \
478   case NAME##iri_nt:                                                           \
479   case NAME##izi_nt:                                                           \
480   case NAME##rri_t:                                                            \
481   case NAME##rzi_t:                                                            \
482   case NAME##iri_t:                                                            \
483   case NAME##izi_t:
484 
485 #define BCRm_kind(NAME)                                                        \
486   case NAME##rr:                                                               \
487   case NAME##ir:                                                               \
488   case NAME##rr_nt:                                                            \
489   case NAME##ir_nt:                                                            \
490   case NAME##rr_t:                                                             \
491   case NAME##ir_t:
492 
493   {
494     using namespace llvm::VE;
495     switch (MI.getOpcode()) {
496       BCm_kind(BCFL) BCm_kind(BCFW) BCRm_kind(BRCFL)
497           BCRm_kind(BRCFW) return true;
498     }
499   }
500 #undef BCm_kind
501 
502   return false;
503 }
504 
505 // Decode CC Operand field.
506 static DecodeStatus DecodeCCOperand(MCInst &MI, uint64_t cf, uint64_t Address,
507                                     const void *Decoder) {
508   MI.addOperand(MCOperand::createImm(VEValToCondCode(cf, isIntegerBCKind(MI))));
509   return MCDisassembler::Success;
510 }
511 
512 // Decode branch condition instruction and CCOperand field in it.
513 static DecodeStatus DecodeBranchCondition(MCInst &MI, uint64_t insn,
514                                           uint64_t Address,
515                                           const void *Decoder) {
516   unsigned cf = fieldFromInstruction(insn, 48, 4);
517   bool cy = fieldFromInstruction(insn, 47, 1);
518   unsigned sy = fieldFromInstruction(insn, 40, 7);
519 
520   // Decode cf.
521   MI.addOperand(MCOperand::createImm(VEValToCondCode(cf, isIntegerBCKind(MI))));
522 
523   // Decode sy.
524   DecodeStatus status;
525   if (cy) {
526     status = DecodeI64RegisterClass(MI, sy, Address, Decoder);
527     if (status != MCDisassembler::Success)
528       return status;
529   } else {
530     MI.addOperand(MCOperand::createImm(SignExtend32<7>(sy)));
531   }
532 
533   // Decode MEMri.
534   return DecodeAS(MI, insn, Address, Decoder);
535 }
536 
537 static DecodeStatus DecodeBranchConditionAlways(MCInst &MI, uint64_t insn,
538                                                 uint64_t Address,
539                                                 const void *Decoder) {
540   // Decode MEMri.
541   return DecodeAS(MI, insn, Address, Decoder);
542 }
543