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1 //===-- ARM/ARMMCCodeEmitter.cpp - Convert ARM code to machine code -------===//
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 // This file implements the ARMMCCodeEmitter class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MCTargetDesc/ARMMCTargetDesc.h"
15 #include "MCTargetDesc/ARMAddressingModes.h"
16 #include "MCTargetDesc/ARMBaseInfo.h"
17 #include "MCTargetDesc/ARMFixupKinds.h"
18 #include "MCTargetDesc/ARMMCExpr.h"
19 #include "llvm/ADT/APFloat.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/MC/MCCodeEmitter.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCExpr.h"
24 #include "llvm/MC/MCInst.h"
25 #include "llvm/MC/MCInstrInfo.h"
26 #include "llvm/MC/MCRegisterInfo.h"
27 #include "llvm/MC/MCSubtargetInfo.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include "llvm/Support/raw_ostream.h"
30 
31 using namespace llvm;
32 
33 #define DEBUG_TYPE "mccodeemitter"
34 
35 STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
36 STATISTIC(MCNumCPRelocations, "Number of constant pool relocations created.");
37 
38 namespace {
39 class ARMMCCodeEmitter : public MCCodeEmitter {
40   ARMMCCodeEmitter(const ARMMCCodeEmitter &) = delete;
41   void operator=(const ARMMCCodeEmitter &) = delete;
42   const MCInstrInfo &MCII;
43   const MCContext &CTX;
44   bool IsLittleEndian;
45 
46 public:
ARMMCCodeEmitter(const MCInstrInfo & mcii,MCContext & ctx,bool IsLittle)47   ARMMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx, bool IsLittle)
48     : MCII(mcii), CTX(ctx), IsLittleEndian(IsLittle) {
49   }
50 
~ARMMCCodeEmitter()51   ~ARMMCCodeEmitter() override {}
52 
isThumb(const MCSubtargetInfo & STI) const53   bool isThumb(const MCSubtargetInfo &STI) const {
54     return STI.getFeatureBits()[ARM::ModeThumb];
55   }
isThumb2(const MCSubtargetInfo & STI) const56   bool isThumb2(const MCSubtargetInfo &STI) const {
57     return isThumb(STI) && STI.getFeatureBits()[ARM::FeatureThumb2];
58   }
isTargetMachO(const MCSubtargetInfo & STI) const59   bool isTargetMachO(const MCSubtargetInfo &STI) const {
60     const Triple &TT = STI.getTargetTriple();
61     return TT.isOSBinFormatMachO();
62   }
63 
64   unsigned getMachineSoImmOpValue(unsigned SoImm) const;
65 
66   // getBinaryCodeForInstr - TableGen'erated function for getting the
67   // binary encoding for an instruction.
68   uint64_t getBinaryCodeForInstr(const MCInst &MI,
69                                  SmallVectorImpl<MCFixup> &Fixups,
70                                  const MCSubtargetInfo &STI) const;
71 
72   /// getMachineOpValue - Return binary encoding of operand. If the machine
73   /// operand requires relocation, record the relocation and return zero.
74   unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
75                              SmallVectorImpl<MCFixup> &Fixups,
76                              const MCSubtargetInfo &STI) const;
77 
78   /// getHiLo16ImmOpValue - Return the encoding for the hi / low 16-bit of
79   /// the specified operand. This is used for operands with :lower16: and
80   /// :upper16: prefixes.
81   uint32_t getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
82                                SmallVectorImpl<MCFixup> &Fixups,
83                                const MCSubtargetInfo &STI) const;
84 
85   bool EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx,
86                               unsigned &Reg, unsigned &Imm,
87                               SmallVectorImpl<MCFixup> &Fixups,
88                               const MCSubtargetInfo &STI) const;
89 
90   /// getThumbBLTargetOpValue - Return encoding info for Thumb immediate
91   /// BL branch target.
92   uint32_t getThumbBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
93                                    SmallVectorImpl<MCFixup> &Fixups,
94                                    const MCSubtargetInfo &STI) const;
95 
96   /// getThumbBLXTargetOpValue - Return encoding info for Thumb immediate
97   /// BLX branch target.
98   uint32_t getThumbBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
99                                     SmallVectorImpl<MCFixup> &Fixups,
100                                     const MCSubtargetInfo &STI) const;
101 
102   /// getThumbBRTargetOpValue - Return encoding info for Thumb branch target.
103   uint32_t getThumbBRTargetOpValue(const MCInst &MI, unsigned OpIdx,
104                                    SmallVectorImpl<MCFixup> &Fixups,
105                                    const MCSubtargetInfo &STI) const;
106 
107   /// getThumbBCCTargetOpValue - Return encoding info for Thumb branch target.
108   uint32_t getThumbBCCTargetOpValue(const MCInst &MI, unsigned OpIdx,
109                                     SmallVectorImpl<MCFixup> &Fixups,
110                                     const MCSubtargetInfo &STI) const;
111 
112   /// getThumbCBTargetOpValue - Return encoding info for Thumb branch target.
113   uint32_t getThumbCBTargetOpValue(const MCInst &MI, unsigned OpIdx,
114                                    SmallVectorImpl<MCFixup> &Fixups,
115                                    const MCSubtargetInfo &STI) const;
116 
117   /// getBranchTargetOpValue - Return encoding info for 24-bit immediate
118   /// branch target.
119   uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
120                                   SmallVectorImpl<MCFixup> &Fixups,
121                                   const MCSubtargetInfo &STI) const;
122 
123   /// getUnconditionalBranchTargetOpValue - Return encoding info for 24-bit
124   /// immediate Thumb2 direct branch target.
125   uint32_t getUnconditionalBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
126                                   SmallVectorImpl<MCFixup> &Fixups,
127                                   const MCSubtargetInfo &STI) const;
128 
129   /// getARMBranchTargetOpValue - Return encoding info for 24-bit immediate
130   /// branch target.
131   uint32_t getARMBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
132                                      SmallVectorImpl<MCFixup> &Fixups,
133                                      const MCSubtargetInfo &STI) const;
134   uint32_t getARMBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
135                                  SmallVectorImpl<MCFixup> &Fixups,
136                                  const MCSubtargetInfo &STI) const;
137   uint32_t getARMBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
138                                   SmallVectorImpl<MCFixup> &Fixups,
139                                   const MCSubtargetInfo &STI) const;
140 
141   /// getAdrLabelOpValue - Return encoding info for 12-bit immediate
142   /// ADR label target.
143   uint32_t getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
144                               SmallVectorImpl<MCFixup> &Fixups,
145                               const MCSubtargetInfo &STI) const;
146   uint32_t getThumbAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
147                               SmallVectorImpl<MCFixup> &Fixups,
148                               const MCSubtargetInfo &STI) const;
149   uint32_t getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
150                               SmallVectorImpl<MCFixup> &Fixups,
151                               const MCSubtargetInfo &STI) const;
152 
153 
154   /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12'
155   /// operand.
156   uint32_t getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
157                                    SmallVectorImpl<MCFixup> &Fixups,
158                                    const MCSubtargetInfo &STI) const;
159 
160   /// getThumbAddrModeRegRegOpValue - Return encoding for 'reg + reg' operand.
161   uint32_t getThumbAddrModeRegRegOpValue(const MCInst &MI, unsigned OpIdx,
162                                          SmallVectorImpl<MCFixup> &Fixups,
163                                          const MCSubtargetInfo &STI) const;
164 
165   /// getT2AddrModeImm8s4OpValue - Return encoding info for 'reg +/- imm8<<2'
166   /// operand.
167   uint32_t getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
168                                    SmallVectorImpl<MCFixup> &Fixups,
169                                    const MCSubtargetInfo &STI) const;
170 
171   /// getT2AddrModeImm0_1020s4OpValue - Return encoding info for 'reg + imm8<<2'
172   /// operand.
173   uint32_t getT2AddrModeImm0_1020s4OpValue(const MCInst &MI, unsigned OpIdx,
174                                    SmallVectorImpl<MCFixup> &Fixups,
175                                    const MCSubtargetInfo &STI) const;
176 
177   /// getT2Imm8s4OpValue - Return encoding info for '+/- imm8<<2'
178   /// operand.
179   uint32_t getT2Imm8s4OpValue(const MCInst &MI, unsigned OpIdx,
180                               SmallVectorImpl<MCFixup> &Fixups,
181                               const MCSubtargetInfo &STI) const;
182 
183 
184   /// getLdStSORegOpValue - Return encoding info for 'reg +/- reg shop imm'
185   /// operand as needed by load/store instructions.
186   uint32_t getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
187                                SmallVectorImpl<MCFixup> &Fixups,
188                                const MCSubtargetInfo &STI) const;
189 
190   /// getLdStmModeOpValue - Return encoding for load/store multiple mode.
getLdStmModeOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const191   uint32_t getLdStmModeOpValue(const MCInst &MI, unsigned OpIdx,
192                                SmallVectorImpl<MCFixup> &Fixups,
193                                const MCSubtargetInfo &STI) const {
194     ARM_AM::AMSubMode Mode = (ARM_AM::AMSubMode)MI.getOperand(OpIdx).getImm();
195     switch (Mode) {
196     default: llvm_unreachable("Unknown addressing sub-mode!");
197     case ARM_AM::da: return 0;
198     case ARM_AM::ia: return 1;
199     case ARM_AM::db: return 2;
200     case ARM_AM::ib: return 3;
201     }
202   }
203   /// getShiftOp - Return the shift opcode (bit[6:5]) of the immediate value.
204   ///
getShiftOp(ARM_AM::ShiftOpc ShOpc) const205   unsigned getShiftOp(ARM_AM::ShiftOpc ShOpc) const {
206     switch (ShOpc) {
207     case ARM_AM::no_shift:
208     case ARM_AM::lsl: return 0;
209     case ARM_AM::lsr: return 1;
210     case ARM_AM::asr: return 2;
211     case ARM_AM::ror:
212     case ARM_AM::rrx: return 3;
213     }
214     llvm_unreachable("Invalid ShiftOpc!");
215   }
216 
217   /// getAddrMode2OpValue - Return encoding for addrmode2 operands.
218   uint32_t getAddrMode2OpValue(const MCInst &MI, unsigned OpIdx,
219                                SmallVectorImpl<MCFixup> &Fixups,
220                                const MCSubtargetInfo &STI) const;
221 
222   /// getAddrMode2OffsetOpValue - Return encoding for am2offset operands.
223   uint32_t getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
224                                      SmallVectorImpl<MCFixup> &Fixups,
225                                      const MCSubtargetInfo &STI) const;
226 
227   /// getPostIdxRegOpValue - Return encoding for postidx_reg operands.
228   uint32_t getPostIdxRegOpValue(const MCInst &MI, unsigned OpIdx,
229                                 SmallVectorImpl<MCFixup> &Fixups,
230                                 const MCSubtargetInfo &STI) const;
231 
232   /// getAddrMode3OffsetOpValue - Return encoding for am3offset operands.
233   uint32_t getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
234                                      SmallVectorImpl<MCFixup> &Fixups,
235                                      const MCSubtargetInfo &STI) const;
236 
237   /// getAddrMode3OpValue - Return encoding for addrmode3 operands.
238   uint32_t getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
239                                SmallVectorImpl<MCFixup> &Fixups,
240                                const MCSubtargetInfo &STI) const;
241 
242   /// getAddrModeThumbSPOpValue - Return encoding info for 'reg +/- imm12'
243   /// operand.
244   uint32_t getAddrModeThumbSPOpValue(const MCInst &MI, unsigned OpIdx,
245                                      SmallVectorImpl<MCFixup> &Fixups,
246                                      const MCSubtargetInfo &STI) const;
247 
248   /// getAddrModeISOpValue - Encode the t_addrmode_is# operands.
249   uint32_t getAddrModeISOpValue(const MCInst &MI, unsigned OpIdx,
250                                 SmallVectorImpl<MCFixup> &Fixups,
251                                 const MCSubtargetInfo &STI) const;
252 
253   /// getAddrModePCOpValue - Return encoding for t_addrmode_pc operands.
254   uint32_t getAddrModePCOpValue(const MCInst &MI, unsigned OpIdx,
255                                 SmallVectorImpl<MCFixup> &Fixups,
256                                 const MCSubtargetInfo &STI) const;
257 
258   /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm8' operand.
259   uint32_t getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
260                                SmallVectorImpl<MCFixup> &Fixups,
261                                const MCSubtargetInfo &STI) const;
262 
263   /// getCCOutOpValue - Return encoding of the 's' bit.
getCCOutOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const264   unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
265                            SmallVectorImpl<MCFixup> &Fixups,
266                            const MCSubtargetInfo &STI) const {
267     // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
268     // '1' respectively.
269     return MI.getOperand(Op).getReg() == ARM::CPSR;
270   }
271 
272   /// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
getSOImmOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const273   unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
274                            SmallVectorImpl<MCFixup> &Fixups,
275                            const MCSubtargetInfo &STI) const {
276 
277     const MCOperand &MO = MI.getOperand(Op);
278 
279     // We expect MO to be an immediate or an expression,
280     // if it is an immediate - that's fine, just encode the value.
281     // Otherwise - create a Fixup.
282     if (MO.isExpr()) {
283       const MCExpr *Expr = MO.getExpr();
284       // In instruction code this value always encoded as lowest 12 bits,
285       // so we don't have to perform any specific adjustments.
286       // Due to requirements of relocatable records we have to use FK_Data_4.
287       // See ARMELFObjectWriter::ExplicitRelSym and
288       //     ARMELFObjectWriter::GetRelocTypeInner for more details.
289       MCFixupKind Kind = MCFixupKind(FK_Data_4);
290       Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
291       return 0;
292     }
293 
294     unsigned SoImm = MO.getImm();
295     int SoImmVal = ARM_AM::getSOImmVal(SoImm);
296     assert(SoImmVal != -1 && "Not a valid so_imm value!");
297 
298     // Encode rotate_imm.
299     unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
300       << ARMII::SoRotImmShift;
301 
302     // Encode immed_8.
303     Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
304     return Binary;
305   }
306 
getModImmOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & ST) const307   unsigned getModImmOpValue(const MCInst &MI, unsigned Op,
308                             SmallVectorImpl<MCFixup> &Fixups,
309                             const MCSubtargetInfo &ST) const {
310     const MCOperand &MO = MI.getOperand(Op);
311 
312     // Support for fixups (MCFixup)
313     if (MO.isExpr()) {
314       const MCExpr *Expr = MO.getExpr();
315       // In instruction code this value always encoded as lowest 12 bits,
316       // so we don't have to perform any specific adjustments.
317       // Due to requirements of relocatable records we have to use FK_Data_4.
318       // See ARMELFObjectWriter::ExplicitRelSym and
319       //     ARMELFObjectWriter::GetRelocTypeInner for more details.
320       MCFixupKind Kind = MCFixupKind(FK_Data_4);
321       Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
322       return 0;
323     }
324 
325     // Immediate is already in its encoded format
326     return MO.getImm();
327   }
328 
329   /// getT2SOImmOpValue - Return an encoded 12-bit shifted-immediate value.
getT2SOImmOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const330   unsigned getT2SOImmOpValue(const MCInst &MI, unsigned Op,
331                            SmallVectorImpl<MCFixup> &Fixups,
332                            const MCSubtargetInfo &STI) const {
333     unsigned SoImm = MI.getOperand(Op).getImm();
334     unsigned Encoded =  ARM_AM::getT2SOImmVal(SoImm);
335     assert(Encoded != ~0U && "Not a Thumb2 so_imm value?");
336     return Encoded;
337   }
338 
339   unsigned getT2AddrModeSORegOpValue(const MCInst &MI, unsigned OpNum,
340     SmallVectorImpl<MCFixup> &Fixups,
341     const MCSubtargetInfo &STI) const;
342   unsigned getT2AddrModeImm8OpValue(const MCInst &MI, unsigned OpNum,
343     SmallVectorImpl<MCFixup> &Fixups,
344     const MCSubtargetInfo &STI) const;
345   unsigned getT2AddrModeImm8OffsetOpValue(const MCInst &MI, unsigned OpNum,
346     SmallVectorImpl<MCFixup> &Fixups,
347     const MCSubtargetInfo &STI) const;
348   unsigned getT2AddrModeImm12OffsetOpValue(const MCInst &MI, unsigned OpNum,
349     SmallVectorImpl<MCFixup> &Fixups,
350     const MCSubtargetInfo &STI) const;
351 
352   /// getSORegOpValue - Return an encoded so_reg shifted register value.
353   unsigned getSORegRegOpValue(const MCInst &MI, unsigned Op,
354                            SmallVectorImpl<MCFixup> &Fixups,
355                            const MCSubtargetInfo &STI) const;
356   unsigned getSORegImmOpValue(const MCInst &MI, unsigned Op,
357                            SmallVectorImpl<MCFixup> &Fixups,
358                            const MCSubtargetInfo &STI) const;
359   unsigned getT2SORegOpValue(const MCInst &MI, unsigned Op,
360                              SmallVectorImpl<MCFixup> &Fixups,
361                              const MCSubtargetInfo &STI) const;
362 
getNEONVcvtImm32OpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const363   unsigned getNEONVcvtImm32OpValue(const MCInst &MI, unsigned Op,
364                                    SmallVectorImpl<MCFixup> &Fixups,
365                                    const MCSubtargetInfo &STI) const {
366     return 64 - MI.getOperand(Op).getImm();
367   }
368 
369   unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
370                                       SmallVectorImpl<MCFixup> &Fixups,
371                                       const MCSubtargetInfo &STI) const;
372 
373   unsigned getRegisterListOpValue(const MCInst &MI, unsigned Op,
374                                   SmallVectorImpl<MCFixup> &Fixups,
375                                   const MCSubtargetInfo &STI) const;
376   unsigned getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
377                                       SmallVectorImpl<MCFixup> &Fixups,
378                                       const MCSubtargetInfo &STI) const;
379   unsigned getAddrMode6OneLane32AddressOpValue(const MCInst &MI, unsigned Op,
380                                         SmallVectorImpl<MCFixup> &Fixups,
381                                         const MCSubtargetInfo &STI) const;
382   unsigned getAddrMode6DupAddressOpValue(const MCInst &MI, unsigned Op,
383                                         SmallVectorImpl<MCFixup> &Fixups,
384                                         const MCSubtargetInfo &STI) const;
385   unsigned getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
386                                      SmallVectorImpl<MCFixup> &Fixups,
387                                      const MCSubtargetInfo &STI) const;
388 
389   unsigned getShiftRight8Imm(const MCInst &MI, unsigned Op,
390                              SmallVectorImpl<MCFixup> &Fixups,
391                              const MCSubtargetInfo &STI) const;
392   unsigned getShiftRight16Imm(const MCInst &MI, unsigned Op,
393                               SmallVectorImpl<MCFixup> &Fixups,
394                               const MCSubtargetInfo &STI) const;
395   unsigned getShiftRight32Imm(const MCInst &MI, unsigned Op,
396                               SmallVectorImpl<MCFixup> &Fixups,
397                               const MCSubtargetInfo &STI) const;
398   unsigned getShiftRight64Imm(const MCInst &MI, unsigned Op,
399                               SmallVectorImpl<MCFixup> &Fixups,
400                               const MCSubtargetInfo &STI) const;
401 
402   unsigned getThumbSRImmOpValue(const MCInst &MI, unsigned Op,
403                                  SmallVectorImpl<MCFixup> &Fixups,
404                                  const MCSubtargetInfo &STI) const;
405 
406   unsigned NEONThumb2DataIPostEncoder(const MCInst &MI,
407                                       unsigned EncodedValue,
408                                       const MCSubtargetInfo &STI) const;
409   unsigned NEONThumb2LoadStorePostEncoder(const MCInst &MI,
410                                           unsigned EncodedValue,
411                                           const MCSubtargetInfo &STI) const;
412   unsigned NEONThumb2DupPostEncoder(const MCInst &MI,
413                                     unsigned EncodedValue,
414                                     const MCSubtargetInfo &STI) const;
415   unsigned NEONThumb2V8PostEncoder(const MCInst &MI,
416                                    unsigned EncodedValue,
417                                    const MCSubtargetInfo &STI) const;
418 
419   unsigned VFPThumb2PostEncoder(const MCInst &MI,
420                                 unsigned EncodedValue,
421                                 const MCSubtargetInfo &STI) const;
422 
EmitByte(unsigned char C,raw_ostream & OS) const423   void EmitByte(unsigned char C, raw_ostream &OS) const {
424     OS << (char)C;
425   }
426 
EmitConstant(uint64_t Val,unsigned Size,raw_ostream & OS) const427   void EmitConstant(uint64_t Val, unsigned Size, raw_ostream &OS) const {
428     // Output the constant in little endian byte order.
429     for (unsigned i = 0; i != Size; ++i) {
430       unsigned Shift = IsLittleEndian ? i * 8 : (Size - 1 - i) * 8;
431       EmitByte((Val >> Shift) & 0xff, OS);
432     }
433   }
434 
435   void encodeInstruction(const MCInst &MI, raw_ostream &OS,
436                          SmallVectorImpl<MCFixup> &Fixups,
437                          const MCSubtargetInfo &STI) const override;
438 };
439 
440 } // end anonymous namespace
441 
createARMLEMCCodeEmitter(const MCInstrInfo & MCII,const MCRegisterInfo & MRI,MCContext & Ctx)442 MCCodeEmitter *llvm::createARMLEMCCodeEmitter(const MCInstrInfo &MCII,
443                                               const MCRegisterInfo &MRI,
444                                               MCContext &Ctx) {
445   return new ARMMCCodeEmitter(MCII, Ctx, true);
446 }
447 
createARMBEMCCodeEmitter(const MCInstrInfo & MCII,const MCRegisterInfo & MRI,MCContext & Ctx)448 MCCodeEmitter *llvm::createARMBEMCCodeEmitter(const MCInstrInfo &MCII,
449                                               const MCRegisterInfo &MRI,
450                                               MCContext &Ctx) {
451   return new ARMMCCodeEmitter(MCII, Ctx, false);
452 }
453 
454 /// NEONThumb2DataIPostEncoder - Post-process encoded NEON data-processing
455 /// instructions, and rewrite them to their Thumb2 form if we are currently in
456 /// Thumb2 mode.
NEONThumb2DataIPostEncoder(const MCInst & MI,unsigned EncodedValue,const MCSubtargetInfo & STI) const457 unsigned ARMMCCodeEmitter::NEONThumb2DataIPostEncoder(const MCInst &MI,
458                                                  unsigned EncodedValue,
459                                                  const MCSubtargetInfo &STI) const {
460   if (isThumb2(STI)) {
461     // NEON Thumb2 data-processsing encodings are very simple: bit 24 is moved
462     // to bit 12 of the high half-word (i.e. bit 28), and bits 27-24 are
463     // set to 1111.
464     unsigned Bit24 = EncodedValue & 0x01000000;
465     unsigned Bit28 = Bit24 << 4;
466     EncodedValue &= 0xEFFFFFFF;
467     EncodedValue |= Bit28;
468     EncodedValue |= 0x0F000000;
469   }
470 
471   return EncodedValue;
472 }
473 
474 /// NEONThumb2LoadStorePostEncoder - Post-process encoded NEON load/store
475 /// instructions, and rewrite them to their Thumb2 form if we are currently in
476 /// Thumb2 mode.
NEONThumb2LoadStorePostEncoder(const MCInst & MI,unsigned EncodedValue,const MCSubtargetInfo & STI) const477 unsigned ARMMCCodeEmitter::NEONThumb2LoadStorePostEncoder(const MCInst &MI,
478                                                  unsigned EncodedValue,
479                                                  const MCSubtargetInfo &STI) const {
480   if (isThumb2(STI)) {
481     EncodedValue &= 0xF0FFFFFF;
482     EncodedValue |= 0x09000000;
483   }
484 
485   return EncodedValue;
486 }
487 
488 /// NEONThumb2DupPostEncoder - Post-process encoded NEON vdup
489 /// instructions, and rewrite them to their Thumb2 form if we are currently in
490 /// Thumb2 mode.
NEONThumb2DupPostEncoder(const MCInst & MI,unsigned EncodedValue,const MCSubtargetInfo & STI) const491 unsigned ARMMCCodeEmitter::NEONThumb2DupPostEncoder(const MCInst &MI,
492                                                  unsigned EncodedValue,
493                                                  const MCSubtargetInfo &STI) const {
494   if (isThumb2(STI)) {
495     EncodedValue &= 0x00FFFFFF;
496     EncodedValue |= 0xEE000000;
497   }
498 
499   return EncodedValue;
500 }
501 
502 /// Post-process encoded NEON v8 instructions, and rewrite them to Thumb2 form
503 /// if we are in Thumb2.
NEONThumb2V8PostEncoder(const MCInst & MI,unsigned EncodedValue,const MCSubtargetInfo & STI) const504 unsigned ARMMCCodeEmitter::NEONThumb2V8PostEncoder(const MCInst &MI,
505                                                  unsigned EncodedValue,
506                                                  const MCSubtargetInfo &STI) const {
507   if (isThumb2(STI)) {
508     EncodedValue |= 0xC000000; // Set bits 27-26
509   }
510 
511   return EncodedValue;
512 }
513 
514 /// VFPThumb2PostEncoder - Post-process encoded VFP instructions and rewrite
515 /// them to their Thumb2 form if we are currently in Thumb2 mode.
516 unsigned ARMMCCodeEmitter::
VFPThumb2PostEncoder(const MCInst & MI,unsigned EncodedValue,const MCSubtargetInfo & STI) const517 VFPThumb2PostEncoder(const MCInst &MI, unsigned EncodedValue,
518                      const MCSubtargetInfo &STI) const {
519   if (isThumb2(STI)) {
520     EncodedValue &= 0x0FFFFFFF;
521     EncodedValue |= 0xE0000000;
522   }
523   return EncodedValue;
524 }
525 
526 /// getMachineOpValue - Return binary encoding of operand. If the machine
527 /// operand requires relocation, record the relocation and return zero.
528 unsigned ARMMCCodeEmitter::
getMachineOpValue(const MCInst & MI,const MCOperand & MO,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const529 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
530                   SmallVectorImpl<MCFixup> &Fixups,
531                   const MCSubtargetInfo &STI) const {
532   if (MO.isReg()) {
533     unsigned Reg = MO.getReg();
534     unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg);
535 
536     // Q registers are encoded as 2x their register number.
537     switch (Reg) {
538     default:
539       return RegNo;
540     case ARM::Q0:  case ARM::Q1:  case ARM::Q2:  case ARM::Q3:
541     case ARM::Q4:  case ARM::Q5:  case ARM::Q6:  case ARM::Q7:
542     case ARM::Q8:  case ARM::Q9:  case ARM::Q10: case ARM::Q11:
543     case ARM::Q12: case ARM::Q13: case ARM::Q14: case ARM::Q15:
544       return 2 * RegNo;
545     }
546   } else if (MO.isImm()) {
547     return static_cast<unsigned>(MO.getImm());
548   } else if (MO.isFPImm()) {
549     return static_cast<unsigned>(APFloat(MO.getFPImm())
550                      .bitcastToAPInt().getHiBits(32).getLimitedValue());
551   }
552 
553   llvm_unreachable("Unable to encode MCOperand!");
554 }
555 
556 /// getAddrModeImmOpValue - Return encoding info for 'reg +/- imm' operand.
557 bool ARMMCCodeEmitter::
EncodeAddrModeOpValues(const MCInst & MI,unsigned OpIdx,unsigned & Reg,unsigned & Imm,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const558 EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx, unsigned &Reg,
559                        unsigned &Imm, SmallVectorImpl<MCFixup> &Fixups,
560  const MCSubtargetInfo &STI) const {
561   const MCOperand &MO  = MI.getOperand(OpIdx);
562   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
563 
564   Reg = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
565 
566   int32_t SImm = MO1.getImm();
567   bool isAdd = true;
568 
569   // Special value for #-0
570   if (SImm == INT32_MIN) {
571     SImm = 0;
572     isAdd = false;
573   }
574 
575   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
576   if (SImm < 0) {
577     SImm = -SImm;
578     isAdd = false;
579   }
580 
581   Imm = SImm;
582   return isAdd;
583 }
584 
585 /// getBranchTargetOpValue - Helper function to get the branch target operand,
586 /// which is either an immediate or requires a fixup.
getBranchTargetOpValue(const MCInst & MI,unsigned OpIdx,unsigned FixupKind,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI)587 static uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
588                                        unsigned FixupKind,
589                                        SmallVectorImpl<MCFixup> &Fixups,
590                                        const MCSubtargetInfo &STI) {
591   const MCOperand &MO = MI.getOperand(OpIdx);
592 
593   // If the destination is an immediate, we have nothing to do.
594   if (MO.isImm()) return MO.getImm();
595   assert(MO.isExpr() && "Unexpected branch target type!");
596   const MCExpr *Expr = MO.getExpr();
597   MCFixupKind Kind = MCFixupKind(FixupKind);
598   Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
599 
600   // All of the information is in the fixup.
601   return 0;
602 }
603 
604 // Thumb BL and BLX use a strange offset encoding where bits 22 and 21 are
605 // determined by negating them and XOR'ing them with bit 23.
encodeThumbBLOffset(int32_t offset)606 static int32_t encodeThumbBLOffset(int32_t offset) {
607   offset >>= 1;
608   uint32_t S  = (offset & 0x800000) >> 23;
609   uint32_t J1 = (offset & 0x400000) >> 22;
610   uint32_t J2 = (offset & 0x200000) >> 21;
611   J1 = (~J1 & 0x1);
612   J2 = (~J2 & 0x1);
613   J1 ^= S;
614   J2 ^= S;
615 
616   offset &= ~0x600000;
617   offset |= J1 << 22;
618   offset |= J2 << 21;
619 
620   return offset;
621 }
622 
623 /// getThumbBLTargetOpValue - Return encoding info for immediate branch target.
624 uint32_t ARMMCCodeEmitter::
getThumbBLTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const625 getThumbBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
626                         SmallVectorImpl<MCFixup> &Fixups,
627                         const MCSubtargetInfo &STI) const {
628   const MCOperand MO = MI.getOperand(OpIdx);
629   if (MO.isExpr())
630     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_bl,
631                                     Fixups, STI);
632   return encodeThumbBLOffset(MO.getImm());
633 }
634 
635 /// getThumbBLXTargetOpValue - Return encoding info for Thumb immediate
636 /// BLX branch target.
637 uint32_t ARMMCCodeEmitter::
getThumbBLXTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const638 getThumbBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
639                          SmallVectorImpl<MCFixup> &Fixups,
640                          const MCSubtargetInfo &STI) const {
641   const MCOperand MO = MI.getOperand(OpIdx);
642   if (MO.isExpr())
643     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_blx,
644                                     Fixups, STI);
645   return encodeThumbBLOffset(MO.getImm());
646 }
647 
648 /// getThumbBRTargetOpValue - Return encoding info for Thumb branch target.
649 uint32_t ARMMCCodeEmitter::
getThumbBRTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const650 getThumbBRTargetOpValue(const MCInst &MI, unsigned OpIdx,
651                         SmallVectorImpl<MCFixup> &Fixups,
652                         const MCSubtargetInfo &STI) const {
653   const MCOperand MO = MI.getOperand(OpIdx);
654   if (MO.isExpr())
655     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_br,
656                                     Fixups, STI);
657   return (MO.getImm() >> 1);
658 }
659 
660 /// getThumbBCCTargetOpValue - Return encoding info for Thumb branch target.
661 uint32_t ARMMCCodeEmitter::
getThumbBCCTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const662 getThumbBCCTargetOpValue(const MCInst &MI, unsigned OpIdx,
663                          SmallVectorImpl<MCFixup> &Fixups,
664                          const MCSubtargetInfo &STI) const {
665   const MCOperand MO = MI.getOperand(OpIdx);
666   if (MO.isExpr())
667     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_bcc,
668                                     Fixups, STI);
669   return (MO.getImm() >> 1);
670 }
671 
672 /// getThumbCBTargetOpValue - Return encoding info for Thumb branch target.
673 uint32_t ARMMCCodeEmitter::
getThumbCBTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const674 getThumbCBTargetOpValue(const MCInst &MI, unsigned OpIdx,
675                         SmallVectorImpl<MCFixup> &Fixups,
676                         const MCSubtargetInfo &STI) const {
677   const MCOperand MO = MI.getOperand(OpIdx);
678   if (MO.isExpr())
679     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_cb, Fixups, STI);
680   return (MO.getImm() >> 1);
681 }
682 
683 /// Return true if this branch has a non-always predication
HasConditionalBranch(const MCInst & MI)684 static bool HasConditionalBranch(const MCInst &MI) {
685   int NumOp = MI.getNumOperands();
686   if (NumOp >= 2) {
687     for (int i = 0; i < NumOp-1; ++i) {
688       const MCOperand &MCOp1 = MI.getOperand(i);
689       const MCOperand &MCOp2 = MI.getOperand(i + 1);
690       if (MCOp1.isImm() && MCOp2.isReg() &&
691           (MCOp2.getReg() == 0 || MCOp2.getReg() == ARM::CPSR)) {
692         if (ARMCC::CondCodes(MCOp1.getImm()) != ARMCC::AL)
693           return true;
694       }
695     }
696   }
697   return false;
698 }
699 
700 /// getBranchTargetOpValue - Return encoding info for 24-bit immediate branch
701 /// target.
702 uint32_t ARMMCCodeEmitter::
getBranchTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const703 getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
704                        SmallVectorImpl<MCFixup> &Fixups,
705                        const MCSubtargetInfo &STI) const {
706   // FIXME: This really, really shouldn't use TargetMachine. We don't want
707   // coupling between MC and TM anywhere we can help it.
708   if (isThumb2(STI))
709     return
710       ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_condbranch, Fixups, STI);
711   return getARMBranchTargetOpValue(MI, OpIdx, Fixups, STI);
712 }
713 
714 /// getBranchTargetOpValue - Return encoding info for 24-bit immediate branch
715 /// target.
716 uint32_t ARMMCCodeEmitter::
getARMBranchTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const717 getARMBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
718                           SmallVectorImpl<MCFixup> &Fixups,
719                           const MCSubtargetInfo &STI) const {
720   const MCOperand MO = MI.getOperand(OpIdx);
721   if (MO.isExpr()) {
722     if (HasConditionalBranch(MI))
723       return ::getBranchTargetOpValue(MI, OpIdx,
724                                       ARM::fixup_arm_condbranch, Fixups, STI);
725     return ::getBranchTargetOpValue(MI, OpIdx,
726                                     ARM::fixup_arm_uncondbranch, Fixups, STI);
727   }
728 
729   return MO.getImm() >> 2;
730 }
731 
732 uint32_t ARMMCCodeEmitter::
getARMBLTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const733 getARMBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
734                           SmallVectorImpl<MCFixup> &Fixups,
735                           const MCSubtargetInfo &STI) const {
736   const MCOperand MO = MI.getOperand(OpIdx);
737   if (MO.isExpr()) {
738     if (HasConditionalBranch(MI))
739       return ::getBranchTargetOpValue(MI, OpIdx,
740                                       ARM::fixup_arm_condbl, Fixups, STI);
741     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_uncondbl, Fixups, STI);
742   }
743 
744   return MO.getImm() >> 2;
745 }
746 
747 uint32_t ARMMCCodeEmitter::
getARMBLXTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const748 getARMBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
749                           SmallVectorImpl<MCFixup> &Fixups,
750                           const MCSubtargetInfo &STI) const {
751   const MCOperand MO = MI.getOperand(OpIdx);
752   if (MO.isExpr())
753     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_blx, Fixups, STI);
754 
755   return MO.getImm() >> 1;
756 }
757 
758 /// getUnconditionalBranchTargetOpValue - Return encoding info for 24-bit
759 /// immediate branch target.
760 uint32_t ARMMCCodeEmitter::
getUnconditionalBranchTargetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const761 getUnconditionalBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
762                        SmallVectorImpl<MCFixup> &Fixups,
763                        const MCSubtargetInfo &STI) const {
764   unsigned Val = 0;
765   const MCOperand MO = MI.getOperand(OpIdx);
766 
767   if(MO.isExpr())
768     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_uncondbranch, Fixups, STI);
769   else
770     Val = MO.getImm() >> 1;
771 
772   bool I  = (Val & 0x800000);
773   bool J1 = (Val & 0x400000);
774   bool J2 = (Val & 0x200000);
775   if (I ^ J1)
776     Val &= ~0x400000;
777   else
778     Val |= 0x400000;
779 
780   if (I ^ J2)
781     Val &= ~0x200000;
782   else
783     Val |= 0x200000;
784 
785   return Val;
786 }
787 
788 /// getAdrLabelOpValue - Return encoding info for 12-bit shifted-immediate
789 /// ADR label target.
790 uint32_t ARMMCCodeEmitter::
getAdrLabelOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const791 getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
792                    SmallVectorImpl<MCFixup> &Fixups,
793                    const MCSubtargetInfo &STI) const {
794   const MCOperand MO = MI.getOperand(OpIdx);
795   if (MO.isExpr())
796     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_adr_pcrel_12,
797                                     Fixups, STI);
798   int64_t offset = MO.getImm();
799   uint32_t Val = 0x2000;
800 
801   int SoImmVal;
802   if (offset == INT32_MIN) {
803     Val = 0x1000;
804     SoImmVal = 0;
805   } else if (offset < 0) {
806     Val = 0x1000;
807     offset *= -1;
808     SoImmVal = ARM_AM::getSOImmVal(offset);
809     if(SoImmVal == -1) {
810       Val = 0x2000;
811       offset *= -1;
812       SoImmVal = ARM_AM::getSOImmVal(offset);
813     }
814   } else {
815     SoImmVal = ARM_AM::getSOImmVal(offset);
816     if(SoImmVal == -1) {
817       Val = 0x1000;
818       offset *= -1;
819       SoImmVal = ARM_AM::getSOImmVal(offset);
820     }
821   }
822 
823   assert(SoImmVal != -1 && "Not a valid so_imm value!");
824 
825   Val |= SoImmVal;
826   return Val;
827 }
828 
829 /// getT2AdrLabelOpValue - Return encoding info for 12-bit immediate ADR label
830 /// target.
831 uint32_t ARMMCCodeEmitter::
getT2AdrLabelOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const832 getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
833                    SmallVectorImpl<MCFixup> &Fixups,
834                    const MCSubtargetInfo &STI) const {
835   const MCOperand MO = MI.getOperand(OpIdx);
836   if (MO.isExpr())
837     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_adr_pcrel_12,
838                                     Fixups, STI);
839   int32_t Val = MO.getImm();
840   if (Val == INT32_MIN)
841     Val = 0x1000;
842   else if (Val < 0) {
843     Val *= -1;
844     Val |= 0x1000;
845   }
846   return Val;
847 }
848 
849 /// getThumbAdrLabelOpValue - Return encoding info for 8-bit immediate ADR label
850 /// target.
851 uint32_t ARMMCCodeEmitter::
getThumbAdrLabelOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const852 getThumbAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
853                    SmallVectorImpl<MCFixup> &Fixups,
854                    const MCSubtargetInfo &STI) const {
855   const MCOperand MO = MI.getOperand(OpIdx);
856   if (MO.isExpr())
857     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_thumb_adr_pcrel_10,
858                                     Fixups, STI);
859   return MO.getImm();
860 }
861 
862 /// getThumbAddrModeRegRegOpValue - Return encoding info for 'reg + reg'
863 /// operand.
864 uint32_t ARMMCCodeEmitter::
getThumbAddrModeRegRegOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> &,const MCSubtargetInfo & STI) const865 getThumbAddrModeRegRegOpValue(const MCInst &MI, unsigned OpIdx,
866                               SmallVectorImpl<MCFixup> &,
867                               const MCSubtargetInfo &STI) const {
868   // [Rn, Rm]
869   //   {5-3} = Rm
870   //   {2-0} = Rn
871   const MCOperand &MO1 = MI.getOperand(OpIdx);
872   const MCOperand &MO2 = MI.getOperand(OpIdx + 1);
873   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
874   unsigned Rm = CTX.getRegisterInfo()->getEncodingValue(MO2.getReg());
875   return (Rm << 3) | Rn;
876 }
877 
878 /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12' operand.
879 uint32_t ARMMCCodeEmitter::
getAddrModeImm12OpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const880 getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
881                         SmallVectorImpl<MCFixup> &Fixups,
882                         const MCSubtargetInfo &STI) const {
883   // {17-13} = reg
884   // {12}    = (U)nsigned (add == '1', sub == '0')
885   // {11-0}  = imm12
886   unsigned Reg, Imm12;
887   bool isAdd = true;
888   // If The first operand isn't a register, we have a label reference.
889   const MCOperand &MO = MI.getOperand(OpIdx);
890   if (!MO.isReg()) {
891     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
892     Imm12 = 0;
893 
894     if (MO.isExpr()) {
895       const MCExpr *Expr = MO.getExpr();
896       isAdd = false ; // 'U' bit is set as part of the fixup.
897 
898       MCFixupKind Kind;
899       if (isThumb2(STI))
900         Kind = MCFixupKind(ARM::fixup_t2_ldst_pcrel_12);
901       else
902         Kind = MCFixupKind(ARM::fixup_arm_ldst_pcrel_12);
903       Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
904 
905       ++MCNumCPRelocations;
906     } else {
907       Reg = ARM::PC;
908       int32_t Offset = MO.getImm();
909       if (Offset == INT32_MIN) {
910         Offset = 0;
911         isAdd = false;
912       } else if (Offset < 0) {
913         Offset *= -1;
914         isAdd = false;
915       }
916       Imm12 = Offset;
917     }
918   } else
919     isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm12, Fixups, STI);
920 
921   uint32_t Binary = Imm12 & 0xfff;
922   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
923   if (isAdd)
924     Binary |= (1 << 12);
925   Binary |= (Reg << 13);
926   return Binary;
927 }
928 
929 /// getT2Imm8s4OpValue - Return encoding info for
930 /// '+/- imm8<<2' operand.
931 uint32_t ARMMCCodeEmitter::
getT2Imm8s4OpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const932 getT2Imm8s4OpValue(const MCInst &MI, unsigned OpIdx,
933                    SmallVectorImpl<MCFixup> &Fixups,
934                    const MCSubtargetInfo &STI) const {
935   // FIXME: The immediate operand should have already been encoded like this
936   // before ever getting here. The encoder method should just need to combine
937   // the MI operands for the register and the offset into a single
938   // representation for the complex operand in the .td file. This isn't just
939   // style, unfortunately. As-is, we can't represent the distinct encoding
940   // for #-0.
941 
942   // {8}    = (U)nsigned (add == '1', sub == '0')
943   // {7-0}  = imm8
944   int32_t Imm8 = MI.getOperand(OpIdx).getImm();
945   bool isAdd = Imm8 >= 0;
946 
947   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
948   if (Imm8 < 0)
949     Imm8 = -(uint32_t)Imm8;
950 
951   // Scaled by 4.
952   Imm8 /= 4;
953 
954   uint32_t Binary = Imm8 & 0xff;
955   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
956   if (isAdd)
957     Binary |= (1 << 8);
958   return Binary;
959 }
960 
961 /// getT2AddrModeImm8s4OpValue - Return encoding info for
962 /// 'reg +/- imm8<<2' operand.
963 uint32_t ARMMCCodeEmitter::
getT2AddrModeImm8s4OpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const964 getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
965                         SmallVectorImpl<MCFixup> &Fixups,
966                         const MCSubtargetInfo &STI) const {
967   // {12-9} = reg
968   // {8}    = (U)nsigned (add == '1', sub == '0')
969   // {7-0}  = imm8
970   unsigned Reg, Imm8;
971   bool isAdd = true;
972   // If The first operand isn't a register, we have a label reference.
973   const MCOperand &MO = MI.getOperand(OpIdx);
974   if (!MO.isReg()) {
975     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
976     Imm8 = 0;
977     isAdd = false ; // 'U' bit is set as part of the fixup.
978 
979     assert(MO.isExpr() && "Unexpected machine operand type!");
980     const MCExpr *Expr = MO.getExpr();
981     MCFixupKind Kind = MCFixupKind(ARM::fixup_t2_pcrel_10);
982     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
983 
984     ++MCNumCPRelocations;
985   } else
986     isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups, STI);
987 
988   // FIXME: The immediate operand should have already been encoded like this
989   // before ever getting here. The encoder method should just need to combine
990   // the MI operands for the register and the offset into a single
991   // representation for the complex operand in the .td file. This isn't just
992   // style, unfortunately. As-is, we can't represent the distinct encoding
993   // for #-0.
994   uint32_t Binary = (Imm8 >> 2) & 0xff;
995   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
996   if (isAdd)
997     Binary |= (1 << 8);
998   Binary |= (Reg << 9);
999   return Binary;
1000 }
1001 
1002 /// getT2AddrModeImm0_1020s4OpValue - Return encoding info for
1003 /// 'reg + imm8<<2' operand.
1004 uint32_t ARMMCCodeEmitter::
getT2AddrModeImm0_1020s4OpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1005 getT2AddrModeImm0_1020s4OpValue(const MCInst &MI, unsigned OpIdx,
1006                         SmallVectorImpl<MCFixup> &Fixups,
1007                         const MCSubtargetInfo &STI) const {
1008   // {11-8} = reg
1009   // {7-0}  = imm8
1010   const MCOperand &MO = MI.getOperand(OpIdx);
1011   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1012   unsigned Reg = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1013   unsigned Imm8 = MO1.getImm();
1014   return (Reg << 8) | Imm8;
1015 }
1016 
1017 uint32_t
getHiLo16ImmOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1018 ARMMCCodeEmitter::getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
1019                                       SmallVectorImpl<MCFixup> &Fixups,
1020                                       const MCSubtargetInfo &STI) const {
1021   // {20-16} = imm{15-12}
1022   // {11-0}  = imm{11-0}
1023   const MCOperand &MO = MI.getOperand(OpIdx);
1024   if (MO.isImm())
1025     // Hi / lo 16 bits already extracted during earlier passes.
1026     return static_cast<unsigned>(MO.getImm());
1027 
1028   // Handle :upper16: and :lower16: assembly prefixes.
1029   const MCExpr *E = MO.getExpr();
1030   MCFixupKind Kind;
1031   if (E->getKind() == MCExpr::Target) {
1032     const ARMMCExpr *ARM16Expr = cast<ARMMCExpr>(E);
1033     E = ARM16Expr->getSubExpr();
1034 
1035     if (const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(E)) {
1036       const int64_t Value = MCE->getValue();
1037       if (Value > UINT32_MAX)
1038         report_fatal_error("constant value truncated (limited to 32-bit)");
1039 
1040       switch (ARM16Expr->getKind()) {
1041       case ARMMCExpr::VK_ARM_HI16:
1042         return (int32_t(Value) & 0xffff0000) >> 16;
1043       case ARMMCExpr::VK_ARM_LO16:
1044         return (int32_t(Value) & 0x0000ffff);
1045       default: llvm_unreachable("Unsupported ARMFixup");
1046       }
1047     }
1048 
1049     switch (ARM16Expr->getKind()) {
1050     default: llvm_unreachable("Unsupported ARMFixup");
1051     case ARMMCExpr::VK_ARM_HI16:
1052       Kind = MCFixupKind(isThumb2(STI) ? ARM::fixup_t2_movt_hi16
1053                                        : ARM::fixup_arm_movt_hi16);
1054       break;
1055     case ARMMCExpr::VK_ARM_LO16:
1056       Kind = MCFixupKind(isThumb2(STI) ? ARM::fixup_t2_movw_lo16
1057                                        : ARM::fixup_arm_movw_lo16);
1058       break;
1059     }
1060 
1061     Fixups.push_back(MCFixup::create(0, E, Kind, MI.getLoc()));
1062     return 0;
1063   }
1064   // If the expression doesn't have :upper16: or :lower16: on it,
1065   // it's just a plain immediate expression, previously those evaluated to
1066   // the lower 16 bits of the expression regardless of whether
1067   // we have a movt or a movw, but that led to misleadingly results.
1068   // This is disallowed in the AsmParser in validateInstruction()
1069   // so this should never happen.
1070   llvm_unreachable("expression without :upper16: or :lower16:");
1071 }
1072 
1073 uint32_t ARMMCCodeEmitter::
getLdStSORegOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1074 getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
1075                     SmallVectorImpl<MCFixup> &Fixups,
1076                     const MCSubtargetInfo &STI) const {
1077   const MCOperand &MO = MI.getOperand(OpIdx);
1078   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1079   const MCOperand &MO2 = MI.getOperand(OpIdx+2);
1080   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1081   unsigned Rm = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1082   unsigned ShImm = ARM_AM::getAM2Offset(MO2.getImm());
1083   bool isAdd = ARM_AM::getAM2Op(MO2.getImm()) == ARM_AM::add;
1084   ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(MO2.getImm());
1085   unsigned SBits = getShiftOp(ShOp);
1086 
1087   // While "lsr #32" and "asr #32" exist, they are encoded with a 0 in the shift
1088   // amount. However, it would be an easy mistake to make so check here.
1089   assert((ShImm & ~0x1f) == 0 && "Out of range shift amount");
1090 
1091   // {16-13} = Rn
1092   // {12}    = isAdd
1093   // {11-0}  = shifter
1094   //  {3-0}  = Rm
1095   //  {4}    = 0
1096   //  {6-5}  = type
1097   //  {11-7} = imm
1098   uint32_t Binary = Rm;
1099   Binary |= Rn << 13;
1100   Binary |= SBits << 5;
1101   Binary |= ShImm << 7;
1102   if (isAdd)
1103     Binary |= 1 << 12;
1104   return Binary;
1105 }
1106 
1107 uint32_t ARMMCCodeEmitter::
getAddrMode2OpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1108 getAddrMode2OpValue(const MCInst &MI, unsigned OpIdx,
1109                     SmallVectorImpl<MCFixup> &Fixups,
1110                     const MCSubtargetInfo &STI) const {
1111   // {17-14}  Rn
1112   // {13}     1 == imm12, 0 == Rm
1113   // {12}     isAdd
1114   // {11-0}   imm12/Rm
1115   const MCOperand &MO = MI.getOperand(OpIdx);
1116   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1117   uint32_t Binary = getAddrMode2OffsetOpValue(MI, OpIdx + 1, Fixups, STI);
1118   Binary |= Rn << 14;
1119   return Binary;
1120 }
1121 
1122 uint32_t ARMMCCodeEmitter::
getAddrMode2OffsetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1123 getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
1124                           SmallVectorImpl<MCFixup> &Fixups,
1125                           const MCSubtargetInfo &STI) const {
1126   // {13}     1 == imm12, 0 == Rm
1127   // {12}     isAdd
1128   // {11-0}   imm12/Rm
1129   const MCOperand &MO = MI.getOperand(OpIdx);
1130   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1131   unsigned Imm = MO1.getImm();
1132   bool isAdd = ARM_AM::getAM2Op(Imm) == ARM_AM::add;
1133   bool isReg = MO.getReg() != 0;
1134   uint32_t Binary = ARM_AM::getAM2Offset(Imm);
1135   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm12
1136   if (isReg) {
1137     ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(Imm);
1138     Binary <<= 7;                    // Shift amount is bits [11:7]
1139     Binary |= getShiftOp(ShOp) << 5; // Shift type is bits [6:5]
1140     Binary |= CTX.getRegisterInfo()->getEncodingValue(MO.getReg()); // Rm is bits [3:0]
1141   }
1142   return Binary | (isAdd << 12) | (isReg << 13);
1143 }
1144 
1145 uint32_t ARMMCCodeEmitter::
getPostIdxRegOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1146 getPostIdxRegOpValue(const MCInst &MI, unsigned OpIdx,
1147                      SmallVectorImpl<MCFixup> &Fixups,
1148                      const MCSubtargetInfo &STI) const {
1149   // {4}      isAdd
1150   // {3-0}    Rm
1151   const MCOperand &MO = MI.getOperand(OpIdx);
1152   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1153   bool isAdd = MO1.getImm() != 0;
1154   return CTX.getRegisterInfo()->getEncodingValue(MO.getReg()) | (isAdd << 4);
1155 }
1156 
1157 uint32_t ARMMCCodeEmitter::
getAddrMode3OffsetOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1158 getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
1159                           SmallVectorImpl<MCFixup> &Fixups,
1160                           const MCSubtargetInfo &STI) const {
1161   // {9}      1 == imm8, 0 == Rm
1162   // {8}      isAdd
1163   // {7-4}    imm7_4/zero
1164   // {3-0}    imm3_0/Rm
1165   const MCOperand &MO = MI.getOperand(OpIdx);
1166   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1167   unsigned Imm = MO1.getImm();
1168   bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
1169   bool isImm = MO.getReg() == 0;
1170   uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
1171   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
1172   if (!isImm)
1173     Imm8 = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1174   return Imm8 | (isAdd << 8) | (isImm << 9);
1175 }
1176 
1177 uint32_t ARMMCCodeEmitter::
getAddrMode3OpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1178 getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
1179                     SmallVectorImpl<MCFixup> &Fixups,
1180                     const MCSubtargetInfo &STI) const {
1181   // {13}     1 == imm8, 0 == Rm
1182   // {12-9}   Rn
1183   // {8}      isAdd
1184   // {7-4}    imm7_4/zero
1185   // {3-0}    imm3_0/Rm
1186   const MCOperand &MO = MI.getOperand(OpIdx);
1187   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1188   const MCOperand &MO2 = MI.getOperand(OpIdx+2);
1189 
1190   // If The first operand isn't a register, we have a label reference.
1191   if (!MO.isReg()) {
1192     unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1193 
1194     assert(MO.isExpr() && "Unexpected machine operand type!");
1195     const MCExpr *Expr = MO.getExpr();
1196     MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_pcrel_10_unscaled);
1197     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1198 
1199     ++MCNumCPRelocations;
1200     return (Rn << 9) | (1 << 13);
1201   }
1202   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1203   unsigned Imm = MO2.getImm();
1204   bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
1205   bool isImm = MO1.getReg() == 0;
1206   uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
1207   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
1208   if (!isImm)
1209     Imm8 = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1210   return (Rn << 9) | Imm8 | (isAdd << 8) | (isImm << 13);
1211 }
1212 
1213 /// getAddrModeThumbSPOpValue - Encode the t_addrmode_sp operands.
1214 uint32_t ARMMCCodeEmitter::
getAddrModeThumbSPOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1215 getAddrModeThumbSPOpValue(const MCInst &MI, unsigned OpIdx,
1216                           SmallVectorImpl<MCFixup> &Fixups,
1217                           const MCSubtargetInfo &STI) const {
1218   // [SP, #imm]
1219   //   {7-0} = imm8
1220   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1221   assert(MI.getOperand(OpIdx).getReg() == ARM::SP &&
1222          "Unexpected base register!");
1223 
1224   // The immediate is already shifted for the implicit zeroes, so no change
1225   // here.
1226   return MO1.getImm() & 0xff;
1227 }
1228 
1229 /// getAddrModeISOpValue - Encode the t_addrmode_is# operands.
1230 uint32_t ARMMCCodeEmitter::
getAddrModeISOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1231 getAddrModeISOpValue(const MCInst &MI, unsigned OpIdx,
1232                      SmallVectorImpl<MCFixup> &Fixups,
1233                      const MCSubtargetInfo &STI) const {
1234   // [Rn, #imm]
1235   //   {7-3} = imm5
1236   //   {2-0} = Rn
1237   const MCOperand &MO = MI.getOperand(OpIdx);
1238   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1239   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1240   unsigned Imm5 = MO1.getImm();
1241   return ((Imm5 & 0x1f) << 3) | Rn;
1242 }
1243 
1244 /// getAddrModePCOpValue - Return encoding for t_addrmode_pc operands.
1245 uint32_t ARMMCCodeEmitter::
getAddrModePCOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1246 getAddrModePCOpValue(const MCInst &MI, unsigned OpIdx,
1247                      SmallVectorImpl<MCFixup> &Fixups,
1248                      const MCSubtargetInfo &STI) const {
1249   const MCOperand MO = MI.getOperand(OpIdx);
1250   if (MO.isExpr())
1251     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_cp, Fixups, STI);
1252   return (MO.getImm() >> 2);
1253 }
1254 
1255 /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm10' operand.
1256 uint32_t ARMMCCodeEmitter::
getAddrMode5OpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1257 getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
1258                     SmallVectorImpl<MCFixup> &Fixups,
1259                     const MCSubtargetInfo &STI) const {
1260   // {12-9} = reg
1261   // {8}    = (U)nsigned (add == '1', sub == '0')
1262   // {7-0}  = imm8
1263   unsigned Reg, Imm8;
1264   bool isAdd;
1265   // If The first operand isn't a register, we have a label reference.
1266   const MCOperand &MO = MI.getOperand(OpIdx);
1267   if (!MO.isReg()) {
1268     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1269     Imm8 = 0;
1270     isAdd = false; // 'U' bit is handled as part of the fixup.
1271 
1272     assert(MO.isExpr() && "Unexpected machine operand type!");
1273     const MCExpr *Expr = MO.getExpr();
1274     MCFixupKind Kind;
1275     if (isThumb2(STI))
1276       Kind = MCFixupKind(ARM::fixup_t2_pcrel_10);
1277     else
1278       Kind = MCFixupKind(ARM::fixup_arm_pcrel_10);
1279     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1280 
1281     ++MCNumCPRelocations;
1282   } else {
1283     EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups, STI);
1284     isAdd = ARM_AM::getAM5Op(Imm8) == ARM_AM::add;
1285   }
1286 
1287   uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
1288   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1289   if (isAdd)
1290     Binary |= (1 << 8);
1291   Binary |= (Reg << 9);
1292   return Binary;
1293 }
1294 
1295 unsigned ARMMCCodeEmitter::
getSORegRegOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1296 getSORegRegOpValue(const MCInst &MI, unsigned OpIdx,
1297                 SmallVectorImpl<MCFixup> &Fixups,
1298                 const MCSubtargetInfo &STI) const {
1299   // Sub-operands are [reg, reg, imm]. The first register is Rm, the reg to be
1300   // shifted. The second is Rs, the amount to shift by, and the third specifies
1301   // the type of the shift.
1302   //
1303   // {3-0} = Rm.
1304   // {4}   = 1
1305   // {6-5} = type
1306   // {11-8} = Rs
1307   // {7}    = 0
1308 
1309   const MCOperand &MO  = MI.getOperand(OpIdx);
1310   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1311   const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
1312   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
1313 
1314   // Encode Rm.
1315   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1316 
1317   // Encode the shift opcode.
1318   unsigned SBits = 0;
1319   unsigned Rs = MO1.getReg();
1320   if (Rs) {
1321     // Set shift operand (bit[7:4]).
1322     // LSL - 0001
1323     // LSR - 0011
1324     // ASR - 0101
1325     // ROR - 0111
1326     switch (SOpc) {
1327     default: llvm_unreachable("Unknown shift opc!");
1328     case ARM_AM::lsl: SBits = 0x1; break;
1329     case ARM_AM::lsr: SBits = 0x3; break;
1330     case ARM_AM::asr: SBits = 0x5; break;
1331     case ARM_AM::ror: SBits = 0x7; break;
1332     }
1333   }
1334 
1335   Binary |= SBits << 4;
1336 
1337   // Encode the shift operation Rs.
1338   // Encode Rs bit[11:8].
1339   assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
1340   return Binary | (CTX.getRegisterInfo()->getEncodingValue(Rs) << ARMII::RegRsShift);
1341 }
1342 
1343 unsigned ARMMCCodeEmitter::
getSORegImmOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1344 getSORegImmOpValue(const MCInst &MI, unsigned OpIdx,
1345                 SmallVectorImpl<MCFixup> &Fixups,
1346                 const MCSubtargetInfo &STI) const {
1347   // Sub-operands are [reg, imm]. The first register is Rm, the reg to be
1348   // shifted. The second is the amount to shift by.
1349   //
1350   // {3-0} = Rm.
1351   // {4}   = 0
1352   // {6-5} = type
1353   // {11-7} = imm
1354 
1355   const MCOperand &MO  = MI.getOperand(OpIdx);
1356   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1357   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
1358 
1359   // Encode Rm.
1360   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1361 
1362   // Encode the shift opcode.
1363   unsigned SBits = 0;
1364 
1365   // Set shift operand (bit[6:4]).
1366   // LSL - 000
1367   // LSR - 010
1368   // ASR - 100
1369   // ROR - 110
1370   // RRX - 110 and bit[11:8] clear.
1371   switch (SOpc) {
1372   default: llvm_unreachable("Unknown shift opc!");
1373   case ARM_AM::lsl: SBits = 0x0; break;
1374   case ARM_AM::lsr: SBits = 0x2; break;
1375   case ARM_AM::asr: SBits = 0x4; break;
1376   case ARM_AM::ror: SBits = 0x6; break;
1377   case ARM_AM::rrx:
1378     Binary |= 0x60;
1379     return Binary;
1380   }
1381 
1382   // Encode shift_imm bit[11:7].
1383   Binary |= SBits << 4;
1384   unsigned Offset = ARM_AM::getSORegOffset(MO1.getImm());
1385   assert(Offset < 32 && "Offset must be in range 0-31!");
1386   return Binary | (Offset << 7);
1387 }
1388 
1389 
1390 unsigned ARMMCCodeEmitter::
getT2AddrModeSORegOpValue(const MCInst & MI,unsigned OpNum,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1391 getT2AddrModeSORegOpValue(const MCInst &MI, unsigned OpNum,
1392                 SmallVectorImpl<MCFixup> &Fixups,
1393                 const MCSubtargetInfo &STI) const {
1394   const MCOperand &MO1 = MI.getOperand(OpNum);
1395   const MCOperand &MO2 = MI.getOperand(OpNum+1);
1396   const MCOperand &MO3 = MI.getOperand(OpNum+2);
1397 
1398   // Encoded as [Rn, Rm, imm].
1399   // FIXME: Needs fixup support.
1400   unsigned Value = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1401   Value <<= 4;
1402   Value |= CTX.getRegisterInfo()->getEncodingValue(MO2.getReg());
1403   Value <<= 2;
1404   Value |= MO3.getImm();
1405 
1406   return Value;
1407 }
1408 
1409 unsigned ARMMCCodeEmitter::
getT2AddrModeImm8OpValue(const MCInst & MI,unsigned OpNum,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1410 getT2AddrModeImm8OpValue(const MCInst &MI, unsigned OpNum,
1411                          SmallVectorImpl<MCFixup> &Fixups,
1412                          const MCSubtargetInfo &STI) const {
1413   const MCOperand &MO1 = MI.getOperand(OpNum);
1414   const MCOperand &MO2 = MI.getOperand(OpNum+1);
1415 
1416   // FIXME: Needs fixup support.
1417   unsigned Value = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1418 
1419   // Even though the immediate is 8 bits long, we need 9 bits in order
1420   // to represent the (inverse of the) sign bit.
1421   Value <<= 9;
1422   int32_t tmp = (int32_t)MO2.getImm();
1423   if (tmp < 0)
1424     tmp = abs(tmp);
1425   else
1426     Value |= 256; // Set the ADD bit
1427   Value |= tmp & 255;
1428   return Value;
1429 }
1430 
1431 unsigned ARMMCCodeEmitter::
getT2AddrModeImm8OffsetOpValue(const MCInst & MI,unsigned OpNum,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1432 getT2AddrModeImm8OffsetOpValue(const MCInst &MI, unsigned OpNum,
1433                          SmallVectorImpl<MCFixup> &Fixups,
1434                          const MCSubtargetInfo &STI) const {
1435   const MCOperand &MO1 = MI.getOperand(OpNum);
1436 
1437   // FIXME: Needs fixup support.
1438   unsigned Value = 0;
1439   int32_t tmp = (int32_t)MO1.getImm();
1440   if (tmp < 0)
1441     tmp = abs(tmp);
1442   else
1443     Value |= 256; // Set the ADD bit
1444   Value |= tmp & 255;
1445   return Value;
1446 }
1447 
1448 unsigned ARMMCCodeEmitter::
getT2AddrModeImm12OffsetOpValue(const MCInst & MI,unsigned OpNum,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1449 getT2AddrModeImm12OffsetOpValue(const MCInst &MI, unsigned OpNum,
1450                          SmallVectorImpl<MCFixup> &Fixups,
1451                          const MCSubtargetInfo &STI) const {
1452   const MCOperand &MO1 = MI.getOperand(OpNum);
1453 
1454   // FIXME: Needs fixup support.
1455   unsigned Value = 0;
1456   int32_t tmp = (int32_t)MO1.getImm();
1457   if (tmp < 0)
1458     tmp = abs(tmp);
1459   else
1460     Value |= 4096; // Set the ADD bit
1461   Value |= tmp & 4095;
1462   return Value;
1463 }
1464 
1465 unsigned ARMMCCodeEmitter::
getT2SORegOpValue(const MCInst & MI,unsigned OpIdx,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1466 getT2SORegOpValue(const MCInst &MI, unsigned OpIdx,
1467                 SmallVectorImpl<MCFixup> &Fixups,
1468                 const MCSubtargetInfo &STI) const {
1469   // Sub-operands are [reg, imm]. The first register is Rm, the reg to be
1470   // shifted. The second is the amount to shift by.
1471   //
1472   // {3-0} = Rm.
1473   // {4}   = 0
1474   // {6-5} = type
1475   // {11-7} = imm
1476 
1477   const MCOperand &MO  = MI.getOperand(OpIdx);
1478   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1479   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
1480 
1481   // Encode Rm.
1482   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1483 
1484   // Encode the shift opcode.
1485   unsigned SBits = 0;
1486   // Set shift operand (bit[6:4]).
1487   // LSL - 000
1488   // LSR - 010
1489   // ASR - 100
1490   // ROR - 110
1491   switch (SOpc) {
1492   default: llvm_unreachable("Unknown shift opc!");
1493   case ARM_AM::lsl: SBits = 0x0; break;
1494   case ARM_AM::lsr: SBits = 0x2; break;
1495   case ARM_AM::asr: SBits = 0x4; break;
1496   case ARM_AM::rrx: // FALLTHROUGH
1497   case ARM_AM::ror: SBits = 0x6; break;
1498   }
1499 
1500   Binary |= SBits << 4;
1501   if (SOpc == ARM_AM::rrx)
1502     return Binary;
1503 
1504   // Encode shift_imm bit[11:7].
1505   return Binary | ARM_AM::getSORegOffset(MO1.getImm()) << 7;
1506 }
1507 
1508 unsigned ARMMCCodeEmitter::
getBitfieldInvertedMaskOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1509 getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
1510                                SmallVectorImpl<MCFixup> &Fixups,
1511                                const MCSubtargetInfo &STI) const {
1512   // 10 bits. lower 5 bits are are the lsb of the mask, high five bits are the
1513   // msb of the mask.
1514   const MCOperand &MO = MI.getOperand(Op);
1515   uint32_t v = ~MO.getImm();
1516   uint32_t lsb = countTrailingZeros(v);
1517   uint32_t msb = (32 - countLeadingZeros (v)) - 1;
1518   assert (v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
1519   return lsb | (msb << 5);
1520 }
1521 
1522 unsigned ARMMCCodeEmitter::
getRegisterListOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1523 getRegisterListOpValue(const MCInst &MI, unsigned Op,
1524                        SmallVectorImpl<MCFixup> &Fixups,
1525                        const MCSubtargetInfo &STI) const {
1526   // VLDM/VSTM:
1527   //   {12-8} = Vd
1528   //   {7-0}  = Number of registers
1529   //
1530   // LDM/STM:
1531   //   {15-0}  = Bitfield of GPRs.
1532   unsigned Reg = MI.getOperand(Op).getReg();
1533   bool SPRRegs = ARMMCRegisterClasses[ARM::SPRRegClassID].contains(Reg);
1534   bool DPRRegs = ARMMCRegisterClasses[ARM::DPRRegClassID].contains(Reg);
1535 
1536   unsigned Binary = 0;
1537 
1538   if (SPRRegs || DPRRegs) {
1539     // VLDM/VSTM
1540     unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg);
1541     unsigned NumRegs = (MI.getNumOperands() - Op) & 0xff;
1542     Binary |= (RegNo & 0x1f) << 8;
1543     if (SPRRegs)
1544       Binary |= NumRegs;
1545     else
1546       Binary |= NumRegs * 2;
1547   } else {
1548     for (unsigned I = Op, E = MI.getNumOperands(); I < E; ++I) {
1549       unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(MI.getOperand(I).getReg());
1550       Binary |= 1 << RegNo;
1551     }
1552   }
1553 
1554   return Binary;
1555 }
1556 
1557 /// getAddrMode6AddressOpValue - Encode an addrmode6 register number along
1558 /// with the alignment operand.
1559 unsigned ARMMCCodeEmitter::
getAddrMode6AddressOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1560 getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
1561                            SmallVectorImpl<MCFixup> &Fixups,
1562                            const MCSubtargetInfo &STI) const {
1563   const MCOperand &Reg = MI.getOperand(Op);
1564   const MCOperand &Imm = MI.getOperand(Op + 1);
1565 
1566   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1567   unsigned Align = 0;
1568 
1569   switch (Imm.getImm()) {
1570   default: break;
1571   case 2:
1572   case 4:
1573   case 8:  Align = 0x01; break;
1574   case 16: Align = 0x02; break;
1575   case 32: Align = 0x03; break;
1576   }
1577 
1578   return RegNo | (Align << 4);
1579 }
1580 
1581 /// getAddrMode6OneLane32AddressOpValue - Encode an addrmode6 register number
1582 /// along  with the alignment operand for use in VST1 and VLD1 with size 32.
1583 unsigned ARMMCCodeEmitter::
getAddrMode6OneLane32AddressOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1584 getAddrMode6OneLane32AddressOpValue(const MCInst &MI, unsigned Op,
1585                                     SmallVectorImpl<MCFixup> &Fixups,
1586                                     const MCSubtargetInfo &STI) const {
1587   const MCOperand &Reg = MI.getOperand(Op);
1588   const MCOperand &Imm = MI.getOperand(Op + 1);
1589 
1590   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1591   unsigned Align = 0;
1592 
1593   switch (Imm.getImm()) {
1594   default: break;
1595   case 8:
1596   case 16:
1597   case 32: // Default '0' value for invalid alignments of 8, 16, 32 bytes.
1598   case 2: Align = 0x00; break;
1599   case 4: Align = 0x03; break;
1600   }
1601 
1602   return RegNo | (Align << 4);
1603 }
1604 
1605 
1606 /// getAddrMode6DupAddressOpValue - Encode an addrmode6 register number and
1607 /// alignment operand for use in VLD-dup instructions.  This is the same as
1608 /// getAddrMode6AddressOpValue except for the alignment encoding, which is
1609 /// different for VLD4-dup.
1610 unsigned ARMMCCodeEmitter::
getAddrMode6DupAddressOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1611 getAddrMode6DupAddressOpValue(const MCInst &MI, unsigned Op,
1612                               SmallVectorImpl<MCFixup> &Fixups,
1613                               const MCSubtargetInfo &STI) const {
1614   const MCOperand &Reg = MI.getOperand(Op);
1615   const MCOperand &Imm = MI.getOperand(Op + 1);
1616 
1617   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1618   unsigned Align = 0;
1619 
1620   switch (Imm.getImm()) {
1621   default: break;
1622   case 2:
1623   case 4:
1624   case 8:  Align = 0x01; break;
1625   case 16: Align = 0x03; break;
1626   }
1627 
1628   return RegNo | (Align << 4);
1629 }
1630 
1631 unsigned ARMMCCodeEmitter::
getAddrMode6OffsetOpValue(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1632 getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
1633                           SmallVectorImpl<MCFixup> &Fixups,
1634                           const MCSubtargetInfo &STI) const {
1635   const MCOperand &MO = MI.getOperand(Op);
1636   if (MO.getReg() == 0) return 0x0D;
1637   return CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1638 }
1639 
1640 unsigned ARMMCCodeEmitter::
getShiftRight8Imm(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1641 getShiftRight8Imm(const MCInst &MI, unsigned Op,
1642                   SmallVectorImpl<MCFixup> &Fixups,
1643                   const MCSubtargetInfo &STI) const {
1644   return 8 - MI.getOperand(Op).getImm();
1645 }
1646 
1647 unsigned ARMMCCodeEmitter::
getShiftRight16Imm(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1648 getShiftRight16Imm(const MCInst &MI, unsigned Op,
1649                    SmallVectorImpl<MCFixup> &Fixups,
1650                    const MCSubtargetInfo &STI) const {
1651   return 16 - MI.getOperand(Op).getImm();
1652 }
1653 
1654 unsigned ARMMCCodeEmitter::
getShiftRight32Imm(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1655 getShiftRight32Imm(const MCInst &MI, unsigned Op,
1656                    SmallVectorImpl<MCFixup> &Fixups,
1657                    const MCSubtargetInfo &STI) const {
1658   return 32 - MI.getOperand(Op).getImm();
1659 }
1660 
1661 unsigned ARMMCCodeEmitter::
getShiftRight64Imm(const MCInst & MI,unsigned Op,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1662 getShiftRight64Imm(const MCInst &MI, unsigned Op,
1663                    SmallVectorImpl<MCFixup> &Fixups,
1664                    const MCSubtargetInfo &STI) const {
1665   return 64 - MI.getOperand(Op).getImm();
1666 }
1667 
1668 void ARMMCCodeEmitter::
encodeInstruction(const MCInst & MI,raw_ostream & OS,SmallVectorImpl<MCFixup> & Fixups,const MCSubtargetInfo & STI) const1669 encodeInstruction(const MCInst &MI, raw_ostream &OS,
1670                   SmallVectorImpl<MCFixup> &Fixups,
1671                   const MCSubtargetInfo &STI) const {
1672   // Pseudo instructions don't get encoded.
1673   const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
1674   uint64_t TSFlags = Desc.TSFlags;
1675   if ((TSFlags & ARMII::FormMask) == ARMII::Pseudo)
1676     return;
1677 
1678   int Size;
1679   if (Desc.getSize() == 2 || Desc.getSize() == 4)
1680     Size = Desc.getSize();
1681   else
1682     llvm_unreachable("Unexpected instruction size!");
1683 
1684   uint32_t Binary = getBinaryCodeForInstr(MI, Fixups, STI);
1685   // Thumb 32-bit wide instructions need to emit the high order halfword
1686   // first.
1687   if (isThumb(STI) && Size == 4) {
1688     EmitConstant(Binary >> 16, 2, OS);
1689     EmitConstant(Binary & 0xffff, 2, OS);
1690   } else
1691     EmitConstant(Binary, Size, OS);
1692   ++MCNumEmitted;  // Keep track of the # of mi's emitted.
1693 }
1694 
1695 #include "ARMGenMCCodeEmitter.inc"
1696