AArch64InstPrinter.cpp revision 36c7806f4eacd676932ba630246f88e0e37b1cd4 
1//==-- AArch64InstPrinter.cpp - Convert AArch64 MCInst to assembly syntax --==//
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 class prints an AArch64 MCInst to a .s file.
11//
12//===----------------------------------------------------------------------===//
13
14#define DEBUG_TYPE "asm-printer"
15#include "AArch64InstPrinter.h"
16#include "MCTargetDesc/AArch64MCTargetDesc.h"
17#include "Utils/AArch64BaseInfo.h"
18#include "llvm/MC/MCInst.h"
19#include "llvm/MC/MCExpr.h"
20#include "llvm/MC/MCRegisterInfo.h"
21#include "llvm/Support/ErrorHandling.h"
22#include "llvm/Support/Format.h"
23#include "llvm/Support/raw_ostream.h"
24
25using namespace llvm;
26
27#define GET_INSTRUCTION_NAME
28#define PRINT_ALIAS_INSTR
29#include "AArch64GenAsmWriter.inc"
30
31static int64_t unpackSignedImm(int BitWidth, uint64_t Value) {
32  assert(!(Value & ~((1ULL << BitWidth)-1)) && "immediate not n-bit");
33  if (Value & (1ULL <<  (BitWidth - 1)))
34    return static_cast<int64_t>(Value) - (1LL << BitWidth);
35  else
36    return Value;
37}
38
39AArch64InstPrinter::AArch64InstPrinter(const MCAsmInfo &MAI,
40                                       const MCInstrInfo &MII,
41                                       const MCRegisterInfo &MRI,
42                                       const MCSubtargetInfo &STI) :
43  MCInstPrinter(MAI, MII, MRI) {
44  // Initialize the set of available features.
45  setAvailableFeatures(STI.getFeatureBits());
46}
47
48void AArch64InstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
49  OS << getRegisterName(RegNo);
50}
51
52void
53AArch64InstPrinter::printOffsetSImm9Operand(const MCInst *MI,
54                                              unsigned OpNum, raw_ostream &O) {
55  const MCOperand &MOImm = MI->getOperand(OpNum);
56  int32_t Imm = unpackSignedImm(9, MOImm.getImm());
57
58  O << '#' << Imm;
59}
60
61void
62AArch64InstPrinter::printAddrRegExtendOperand(const MCInst *MI, unsigned OpNum,
63                                          raw_ostream &O, unsigned MemSize,
64                                          unsigned RmSize) {
65  unsigned ExtImm = MI->getOperand(OpNum).getImm();
66  unsigned OptionHi = ExtImm >> 1;
67  unsigned S = ExtImm & 1;
68  bool IsLSL = OptionHi == 1 && RmSize == 64;
69
70  const char *Ext;
71  switch (OptionHi) {
72  case 1:
73    Ext = (RmSize == 32) ? "uxtw" : "lsl";
74    break;
75  case 3:
76    Ext = (RmSize == 32) ? "sxtw" : "sxtx";
77    break;
78  default:
79    llvm_unreachable("Incorrect Option on load/store (reg offset)");
80  }
81  O << Ext;
82
83  if (S) {
84    unsigned ShiftAmt = Log2_32(MemSize);
85    O << " #" << ShiftAmt;
86  } else if (IsLSL) {
87    O << " #0";
88  }
89}
90
91void
92AArch64InstPrinter::printAddSubImmLSL0Operand(const MCInst *MI,
93                                              unsigned OpNum, raw_ostream &O) {
94  const MCOperand &Imm12Op = MI->getOperand(OpNum);
95
96  if (Imm12Op.isImm()) {
97    int64_t Imm12 = Imm12Op.getImm();
98    assert(Imm12 >= 0 && "Invalid immediate for add/sub imm");
99    O << "#" << Imm12;
100  } else {
101    assert(Imm12Op.isExpr() && "Unexpected shift operand type");
102    O << "#" << *Imm12Op.getExpr();
103  }
104}
105
106void
107AArch64InstPrinter::printAddSubImmLSL12Operand(const MCInst *MI, unsigned OpNum,
108                                               raw_ostream &O) {
109
110  printAddSubImmLSL0Operand(MI, OpNum, O);
111
112  O << ", lsl #12";
113}
114
115void
116AArch64InstPrinter::printBareImmOperand(const MCInst *MI, unsigned OpNum,
117                                        raw_ostream &O) {
118  const MCOperand &MO = MI->getOperand(OpNum);
119  O << MO.getImm();
120}
121
122template<unsigned RegWidth> void
123AArch64InstPrinter::printBFILSBOperand(const MCInst *MI, unsigned OpNum,
124                                       raw_ostream &O) {
125  const MCOperand &ImmROp = MI->getOperand(OpNum);
126  unsigned LSB = ImmROp.getImm() == 0 ? 0 : RegWidth - ImmROp.getImm();
127
128  O << '#' << LSB;
129}
130
131void AArch64InstPrinter::printBFIWidthOperand(const MCInst *MI, unsigned OpNum,
132                                              raw_ostream &O) {
133  const MCOperand &ImmSOp = MI->getOperand(OpNum);
134  unsigned Width = ImmSOp.getImm() + 1;
135
136  O << '#' << Width;
137}
138
139void
140AArch64InstPrinter::printBFXWidthOperand(const MCInst *MI, unsigned OpNum,
141                                         raw_ostream &O) {
142  const MCOperand &ImmSOp = MI->getOperand(OpNum);
143  const MCOperand &ImmROp = MI->getOperand(OpNum - 1);
144
145  unsigned ImmR = ImmROp.getImm();
146  unsigned ImmS = ImmSOp.getImm();
147
148  assert(ImmS >= ImmR && "Invalid ImmR, ImmS combination for bitfield extract");
149
150  O << '#' << (ImmS - ImmR + 1);
151}
152
153void
154AArch64InstPrinter::printCRxOperand(const MCInst *MI, unsigned OpNum,
155                                    raw_ostream &O) {
156    const MCOperand &CRx = MI->getOperand(OpNum);
157
158    O << 'c' << CRx.getImm();
159}
160
161
162void
163AArch64InstPrinter::printCVTFixedPosOperand(const MCInst *MI, unsigned OpNum,
164                                            raw_ostream &O) {
165    const MCOperand &ScaleOp = MI->getOperand(OpNum);
166
167    O << '#' << (64 - ScaleOp.getImm());
168}
169
170
171void AArch64InstPrinter::printFPImmOperand(const MCInst *MI, unsigned OpNum,
172                                           raw_ostream &o) {
173  const MCOperand &MOImm8 = MI->getOperand(OpNum);
174
175  assert(MOImm8.isImm()
176         && "Immediate operand required for floating-point immediate inst");
177
178  uint32_t Imm8 = MOImm8.getImm();
179  uint32_t Fraction = Imm8 & 0xf;
180  uint32_t Exponent = (Imm8 >> 4) & 0x7;
181  uint32_t Negative = (Imm8 >> 7) & 0x1;
182
183  float Val = 1.0f + Fraction / 16.0f;
184
185  // That is:
186  // 000 -> 2^1,  001 -> 2^2,  010 -> 2^3,  011 -> 2^4,
187  // 100 -> 2^-3, 101 -> 2^-2, 110 -> 2^-1, 111 -> 2^0
188  if (Exponent & 0x4) {
189    Val /= 1 << (7 - Exponent);
190  } else {
191    Val *= 1 << (Exponent + 1);
192  }
193
194  Val = Negative ? -Val : Val;
195
196  o << '#' << format("%.8f", Val);
197}
198
199void AArch64InstPrinter::printFPZeroOperand(const MCInst *MI, unsigned OpNum,
200                                            raw_ostream &o) {
201  o << "#0.0";
202}
203
204void
205AArch64InstPrinter::printCondCodeOperand(const MCInst *MI, unsigned OpNum,
206                                         raw_ostream &O) {
207  const MCOperand &MO = MI->getOperand(OpNum);
208
209  O << A64CondCodeToString(static_cast<A64CC::CondCodes>(MO.getImm()));
210}
211
212template <unsigned field_width, unsigned scale> void
213AArch64InstPrinter::printLabelOperand(const MCInst *MI, unsigned OpNum,
214                                            raw_ostream &O) {
215  const MCOperand &MO = MI->getOperand(OpNum);
216
217  if (!MO.isImm()) {
218    printOperand(MI, OpNum, O);
219    return;
220  }
221
222  // The immediate of LDR (lit) instructions is a signed 19-bit immediate, which
223  // is multiplied by 4 (because all A64 instructions are 32-bits wide).
224  uint64_t UImm = MO.getImm();
225  uint64_t Sign = UImm & (1LL << (field_width - 1));
226  int64_t SImm = scale * ((UImm & ~Sign) - Sign);
227
228  O << "#" << SImm;
229}
230
231template<unsigned RegWidth> void
232AArch64InstPrinter::printLogicalImmOperand(const MCInst *MI, unsigned OpNum,
233                                           raw_ostream &O) {
234  const MCOperand &MO = MI->getOperand(OpNum);
235  uint64_t Val;
236  A64Imms::isLogicalImmBits(RegWidth, MO.getImm(), Val);
237  O << "#0x";
238  O.write_hex(Val);
239}
240
241void
242AArch64InstPrinter::printOffsetUImm12Operand(const MCInst *MI, unsigned OpNum,
243                                               raw_ostream &O, int MemSize) {
244  const MCOperand &MOImm = MI->getOperand(OpNum);
245
246  if (MOImm.isImm()) {
247    uint32_t Imm = MOImm.getImm() * MemSize;
248
249    O << "#" << Imm;
250  } else {
251    O << "#" << *MOImm.getExpr();
252  }
253}
254
255void
256AArch64InstPrinter::printShiftOperand(const MCInst *MI,  unsigned OpNum,
257                                      raw_ostream &O,
258                                      A64SE::ShiftExtSpecifiers Shift) {
259    const MCOperand &MO = MI->getOperand(OpNum);
260
261    // LSL #0 is not printed
262    if (Shift == A64SE::LSL && MO.isImm() && MO.getImm() == 0)
263        return;
264
265    switch (Shift) {
266    case A64SE::LSL: O << "lsl"; break;
267    case A64SE::LSR: O << "lsr"; break;
268    case A64SE::ASR: O << "asr"; break;
269    case A64SE::ROR: O << "ror"; break;
270    default: llvm_unreachable("Invalid shift specifier in logical instruction");
271    }
272
273  O << " #" << MO.getImm();
274}
275
276void
277AArch64InstPrinter::printMoveWideImmOperand(const MCInst *MI,  unsigned OpNum,
278                                            raw_ostream &O) {
279  const MCOperand &UImm16MO = MI->getOperand(OpNum);
280  const MCOperand &ShiftMO = MI->getOperand(OpNum + 1);
281
282  if (UImm16MO.isImm()) {
283    O << '#' << UImm16MO.getImm();
284
285    if (ShiftMO.getImm() != 0)
286      O << ", lsl #" << (ShiftMO.getImm() * 16);
287
288    return;
289  }
290
291  O << "#" << *UImm16MO.getExpr();
292}
293
294void AArch64InstPrinter::printNamedImmOperand(const NamedImmMapper &Mapper,
295                                              const MCInst *MI, unsigned OpNum,
296                                              raw_ostream &O) {
297  bool ValidName;
298  const MCOperand &MO = MI->getOperand(OpNum);
299  StringRef Name = Mapper.toString(MO.getImm(), ValidName);
300
301  if (ValidName)
302    O << Name;
303  else
304    O << '#' << MO.getImm();
305}
306
307void
308AArch64InstPrinter::printSysRegOperand(const A64SysReg::SysRegMapper &Mapper,
309                                       const MCInst *MI, unsigned OpNum,
310                                       raw_ostream &O) {
311  const MCOperand &MO = MI->getOperand(OpNum);
312
313  bool ValidName;
314  std::string Name = Mapper.toString(MO.getImm(), ValidName);
315  if (ValidName) {
316    O << Name;
317    return;
318  }
319}
320
321
322void AArch64InstPrinter::printRegExtendOperand(const MCInst *MI,
323                                               unsigned OpNum,
324                                               raw_ostream &O,
325                                               A64SE::ShiftExtSpecifiers Ext) {
326  // FIXME: In principle TableGen should be able to detect this itself far more
327  // easily. We will only accumulate more of these hacks.
328  unsigned Reg0 = MI->getOperand(0).getReg();
329  unsigned Reg1 = MI->getOperand(1).getReg();
330
331  if (isStackReg(Reg0) || isStackReg(Reg1)) {
332    A64SE::ShiftExtSpecifiers LSLEquiv;
333
334    if (Reg0 == AArch64::XSP || Reg1 == AArch64::XSP)
335      LSLEquiv = A64SE::UXTX;
336    else
337      LSLEquiv = A64SE::UXTW;
338
339    if (Ext == LSLEquiv) {
340      O << "lsl #" << MI->getOperand(OpNum).getImm();
341      return;
342    }
343  }
344
345  switch (Ext) {
346  case A64SE::UXTB: O << "uxtb"; break;
347  case A64SE::UXTH: O << "uxth"; break;
348  case A64SE::UXTW: O << "uxtw"; break;
349  case A64SE::UXTX: O << "uxtx"; break;
350  case A64SE::SXTB: O << "sxtb"; break;
351  case A64SE::SXTH: O << "sxth"; break;
352  case A64SE::SXTW: O << "sxtw"; break;
353  case A64SE::SXTX: O << "sxtx"; break;
354  default: llvm_unreachable("Unexpected shift type for printing");
355  }
356
357  const MCOperand &MO = MI->getOperand(OpNum);
358  if (MO.getImm() != 0)
359    O << " #" << MO.getImm();
360}
361
362template<int MemScale> void
363AArch64InstPrinter::printSImm7ScaledOperand(const MCInst *MI, unsigned OpNum,
364                                      raw_ostream &O) {
365  const MCOperand &MOImm = MI->getOperand(OpNum);
366  int32_t Imm = unpackSignedImm(7, MOImm.getImm());
367
368  O << "#" << (Imm * MemScale);
369}
370
371void AArch64InstPrinter::printVPRRegister(const MCInst *MI, unsigned OpNo,
372                                          raw_ostream &O) {
373  unsigned Reg = MI->getOperand(OpNo).getReg();
374  std::string Name = getRegisterName(Reg);
375  Name[0] = 'v';
376  O << Name;
377}
378
379void AArch64InstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
380                                      raw_ostream &O) {
381  const MCOperand &Op = MI->getOperand(OpNo);
382  if (Op.isReg()) {
383    unsigned Reg = Op.getReg();
384    O << getRegisterName(Reg);
385  } else if (Op.isImm()) {
386    O << '#' << Op.getImm();
387  } else {
388    assert(Op.isExpr() && "unknown operand kind in printOperand");
389    // If a symbolic branch target was added as a constant expression then print
390    // that address in hex.
391    const MCConstantExpr *BranchTarget = dyn_cast<MCConstantExpr>(Op.getExpr());
392    int64_t Address;
393    if (BranchTarget && BranchTarget->EvaluateAsAbsolute(Address)) {
394      O << "0x";
395      O.write_hex(Address);
396    }
397    else {
398      // Otherwise, just print the expression.
399      O << *Op.getExpr();
400    }
401  }
402}
403
404
405void AArch64InstPrinter::printInst(const MCInst *MI, raw_ostream &O,
406                                   StringRef Annot) {
407  if (MI->getOpcode() == AArch64::TLSDESCCALL) {
408    // This is a special assembler directive which applies an
409    // R_AARCH64_TLSDESC_CALL to the following (BLR) instruction. It has a fixed
410    // form outside the normal TableGenerated scheme.
411    O << "\t.tlsdesccall " << *MI->getOperand(0).getExpr();
412  } else if (!printAliasInstr(MI, O))
413    printInstruction(MI, O);
414
415  printAnnotation(O, Annot);
416}
417
418template <A64SE::ShiftExtSpecifiers Ext, bool isHalf>
419void AArch64InstPrinter::printNeonMovImmShiftOperand(const MCInst *MI,
420                                                     unsigned OpNum,
421                                                     raw_ostream &O) {
422  const MCOperand &MO = MI->getOperand(OpNum);
423
424  assert(MO.isImm() &&
425         "Immediate operand required for Neon vector immediate inst.");
426
427  bool IsLSL = false;
428  if (Ext == A64SE::LSL)
429    IsLSL = true;
430  else if (Ext != A64SE::MSL)
431    llvm_unreachable("Invalid shift specifier in movi instruction");
432
433  int64_t Imm = MO.getImm();
434
435  // MSL and LSLH accepts encoded shift amount 0 or 1.
436  if ((!IsLSL || (IsLSL && isHalf)) && Imm != 0 && Imm != 1)
437    llvm_unreachable("Invalid shift amount in movi instruction");
438
439  // LSH accepts encoded shift amount 0, 1, 2 or 3.
440  if (IsLSL && (Imm < 0 || Imm > 3))
441    llvm_unreachable("Invalid shift amount in movi instruction");
442
443  // Print shift amount as multiple of 8 with MSL encoded shift amount
444  // 0 and 1 printed as 8 and 16.
445  if (!IsLSL)
446    Imm++;
447  Imm *= 8;
448
449  // LSL #0 is not printed
450  if (IsLSL) {
451    if (Imm == 0)
452      return;
453    O << ", lsl";
454  } else
455    O << ", msl";
456
457  O << " #" << Imm;
458}
459
460void AArch64InstPrinter::printNeonUImm0Operand(const MCInst *MI, unsigned OpNum,
461                                               raw_ostream &o) {
462  o << "#0x0";
463}
464
465void AArch64InstPrinter::printUImmHexOperand(const MCInst *MI, unsigned OpNum,
466                                             raw_ostream &O) {
467  const MCOperand &MOUImm = MI->getOperand(OpNum);
468
469  assert(MOUImm.isImm() &&
470         "Immediate operand required for Neon vector immediate inst.");
471
472  unsigned Imm = MOUImm.getImm();
473
474  O << "#0x";
475  O.write_hex(Imm);
476}
477
478void AArch64InstPrinter::printUImmBareOperand(const MCInst *MI,
479                                              unsigned OpNum,
480                                              raw_ostream &O) {
481  const MCOperand &MOUImm = MI->getOperand(OpNum);
482
483  assert(MOUImm.isImm()
484         && "Immediate operand required for Neon vector immediate inst.");
485
486  unsigned Imm = MOUImm.getImm();
487  O << Imm;
488}
489
490void AArch64InstPrinter::printNeonUImm64MaskOperand(const MCInst *MI,
491                                                    unsigned OpNum,
492                                                    raw_ostream &O) {
493  const MCOperand &MOUImm8 = MI->getOperand(OpNum);
494
495  assert(MOUImm8.isImm() &&
496         "Immediate operand required for Neon vector immediate bytemask inst.");
497
498  uint32_t UImm8 = MOUImm8.getImm();
499  uint64_t Mask = 0;
500
501  // Replicates 0x00 or 0xff byte in a 64-bit vector
502  for (unsigned ByteNum = 0; ByteNum < 8; ++ByteNum) {
503    if ((UImm8 >> ByteNum) & 1)
504      Mask |= (uint64_t)0xff << (8 * ByteNum);
505  }
506
507  O << "#0x";
508  O.write_hex(Mask);
509}
510
511// If Count > 1, there are two valid kinds of vector list:
512//   (1) {Vn.layout, Vn+1.layout, ... , Vm.layout}
513//   (2) {Vn.layout - Vm.layout}
514// We choose the first kind as output.
515template <A64Layout::VectorLayout Layout, unsigned Count>
516void AArch64InstPrinter::printVectorList(const MCInst *MI, unsigned OpNum,
517                                         raw_ostream &O) {
518  assert(Count >= 1 && Count <= 4 && "Invalid Number of Vectors");
519
520  unsigned Reg = MI->getOperand(OpNum).getReg();
521  std::string LayoutStr = A64VectorLayoutToString(Layout);
522  O << "{";
523  if (Count > 1) { // Print sub registers separately
524    bool IsVec64 = (Layout < A64Layout::_16B);
525    unsigned SubRegIdx = IsVec64 ? AArch64::dsub_0 : AArch64::qsub_0;
526    for (unsigned I = 0; I < Count; I++) {
527      std::string Name = getRegisterName(MRI.getSubReg(Reg, SubRegIdx++));
528      Name[0] = 'v';
529      O << Name << LayoutStr;
530      if (I != Count - 1)
531        O << ", ";
532    }
533  } else { // Print the register directly when NumVecs is 1.
534    std::string Name = getRegisterName(Reg);
535    Name[0] = 'v';
536    O << Name << LayoutStr;
537  }
538  O << "}";
539}
540