1 //===-- MipsMCCodeEmitter.cpp - Convert Mips 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 MipsMCCodeEmitter class.
11 //
12 //===----------------------------------------------------------------------===//
13 //
14 
15 #include "MipsMCCodeEmitter.h"
16 #include "MCTargetDesc/MipsFixupKinds.h"
17 #include "MCTargetDesc/MipsMCExpr.h"
18 #include "MCTargetDesc/MipsMCTargetDesc.h"
19 #include "llvm/ADT/APFloat.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCExpr.h"
23 #include "llvm/MC/MCFixup.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/raw_ostream.h"
29 
30 #define DEBUG_TYPE "mccodeemitter"
31 
32 #define GET_INSTRMAP_INFO
33 #include "MipsGenInstrInfo.inc"
34 #undef GET_INSTRMAP_INFO
35 
36 namespace llvm {
37 MCCodeEmitter *createMipsMCCodeEmitterEB(const MCInstrInfo &MCII,
38                                          const MCRegisterInfo &MRI,
39                                          MCContext &Ctx) {
40   return new MipsMCCodeEmitter(MCII, Ctx, false);
41 }
42 
43 MCCodeEmitter *createMipsMCCodeEmitterEL(const MCInstrInfo &MCII,
44                                          const MCRegisterInfo &MRI,
45                                          MCContext &Ctx) {
46   return new MipsMCCodeEmitter(MCII, Ctx, true);
47 }
48 } // End of namespace llvm.
49 
50 // If the D<shift> instruction has a shift amount that is greater
51 // than 31 (checked in calling routine), lower it to a D<shift>32 instruction
52 static void LowerLargeShift(MCInst& Inst) {
53 
54   assert(Inst.getNumOperands() == 3 && "Invalid no. of operands for shift!");
55   assert(Inst.getOperand(2).isImm());
56 
57   int64_t Shift = Inst.getOperand(2).getImm();
58   if (Shift <= 31)
59     return; // Do nothing
60   Shift -= 32;
61 
62   // saminus32
63   Inst.getOperand(2).setImm(Shift);
64 
65   switch (Inst.getOpcode()) {
66   default:
67     // Calling function is not synchronized
68     llvm_unreachable("Unexpected shift instruction");
69   case Mips::DSLL:
70     Inst.setOpcode(Mips::DSLL32);
71     return;
72   case Mips::DSRL:
73     Inst.setOpcode(Mips::DSRL32);
74     return;
75   case Mips::DSRA:
76     Inst.setOpcode(Mips::DSRA32);
77     return;
78   case Mips::DROTR:
79     Inst.setOpcode(Mips::DROTR32);
80     return;
81   }
82 }
83 
84 // Pick a DEXT or DINS instruction variant based on the pos and size operands
85 static void LowerDextDins(MCInst& InstIn) {
86   int Opcode = InstIn.getOpcode();
87 
88   if (Opcode == Mips::DEXT)
89     assert(InstIn.getNumOperands() == 4 &&
90            "Invalid no. of machine operands for DEXT!");
91   else // Only DEXT and DINS are possible
92     assert(InstIn.getNumOperands() == 5 &&
93            "Invalid no. of machine operands for DINS!");
94 
95   assert(InstIn.getOperand(2).isImm());
96   int64_t pos = InstIn.getOperand(2).getImm();
97   assert(InstIn.getOperand(3).isImm());
98   int64_t size = InstIn.getOperand(3).getImm();
99 
100   if (size <= 32) {
101     if (pos < 32)  // DEXT/DINS, do nothing
102       return;
103     // DEXTU/DINSU
104     InstIn.getOperand(2).setImm(pos - 32);
105     InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTU : Mips::DINSU);
106     return;
107   }
108   // DEXTM/DINSM
109   assert(pos < 32 && "DEXT/DINS cannot have both size and pos > 32");
110   InstIn.getOperand(3).setImm(size - 32);
111   InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTM : Mips::DINSM);
112   return;
113 }
114 
115 bool MipsMCCodeEmitter::isMicroMips(const MCSubtargetInfo &STI) const {
116   return STI.getFeatureBits()[Mips::FeatureMicroMips];
117 }
118 
119 bool MipsMCCodeEmitter::isMips32r6(const MCSubtargetInfo &STI) const {
120   return STI.getFeatureBits()[Mips::FeatureMips32r6];
121 }
122 
123 void MipsMCCodeEmitter::EmitByte(unsigned char C, raw_ostream &OS) const {
124   OS << (char)C;
125 }
126 
127 void MipsMCCodeEmitter::EmitInstruction(uint64_t Val, unsigned Size,
128                                         const MCSubtargetInfo &STI,
129                                         raw_ostream &OS) const {
130   // Output the instruction encoding in little endian byte order.
131   // Little-endian byte ordering:
132   //   mips32r2:   4 | 3 | 2 | 1
133   //   microMIPS:  2 | 1 | 4 | 3
134   if (IsLittleEndian && Size == 4 && isMicroMips(STI)) {
135     EmitInstruction(Val >> 16, 2, STI, OS);
136     EmitInstruction(Val, 2, STI, OS);
137   } else {
138     for (unsigned i = 0; i < Size; ++i) {
139       unsigned Shift = IsLittleEndian ? i * 8 : (Size - 1 - i) * 8;
140       EmitByte((Val >> Shift) & 0xff, OS);
141     }
142   }
143 }
144 
145 /// encodeInstruction - Emit the instruction.
146 /// Size the instruction with Desc.getSize().
147 void MipsMCCodeEmitter::
148 encodeInstruction(const MCInst &MI, raw_ostream &OS,
149                   SmallVectorImpl<MCFixup> &Fixups,
150                   const MCSubtargetInfo &STI) const
151 {
152 
153   // Non-pseudo instructions that get changed for direct object
154   // only based on operand values.
155   // If this list of instructions get much longer we will move
156   // the check to a function call. Until then, this is more efficient.
157   MCInst TmpInst = MI;
158   switch (MI.getOpcode()) {
159   // If shift amount is >= 32 it the inst needs to be lowered further
160   case Mips::DSLL:
161   case Mips::DSRL:
162   case Mips::DSRA:
163   case Mips::DROTR:
164     LowerLargeShift(TmpInst);
165     break;
166     // Double extract instruction is chosen by pos and size operands
167   case Mips::DEXT:
168   case Mips::DINS:
169     LowerDextDins(TmpInst);
170   }
171 
172   unsigned long N = Fixups.size();
173   uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI);
174 
175   // Check for unimplemented opcodes.
176   // Unfortunately in MIPS both NOP and SLL will come in with Binary == 0
177   // so we have to special check for them.
178   unsigned Opcode = TmpInst.getOpcode();
179   if ((Opcode != Mips::NOP) && (Opcode != Mips::SLL) &&
180       (Opcode != Mips::SLL_MM) && !Binary)
181     llvm_unreachable("unimplemented opcode in encodeInstruction()");
182 
183   int NewOpcode = -1;
184   if (isMicroMips(STI)) {
185     if (isMips32r6(STI)) {
186       NewOpcode = Mips::MipsR62MicroMipsR6(Opcode, Mips::Arch_micromipsr6);
187       if (NewOpcode == -1)
188         NewOpcode = Mips::Std2MicroMipsR6(Opcode, Mips::Arch_micromipsr6);
189     }
190     else
191       NewOpcode = Mips::Std2MicroMips(Opcode, Mips::Arch_micromips);
192 
193     // Check whether it is Dsp instruction.
194     if (NewOpcode == -1)
195       NewOpcode = Mips::Dsp2MicroMips(Opcode, Mips::Arch_mmdsp);
196 
197     if (NewOpcode != -1) {
198       if (Fixups.size() > N)
199         Fixups.pop_back();
200 
201       Opcode = NewOpcode;
202       TmpInst.setOpcode (NewOpcode);
203       Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI);
204     }
205   }
206 
207   const MCInstrDesc &Desc = MCII.get(TmpInst.getOpcode());
208 
209   // Get byte count of instruction
210   unsigned Size = Desc.getSize();
211   if (!Size)
212     llvm_unreachable("Desc.getSize() returns 0");
213 
214   EmitInstruction(Binary, Size, STI, OS);
215 }
216 
217 /// getBranchTargetOpValue - Return binary encoding of the branch
218 /// target operand. If the machine operand requires relocation,
219 /// record the relocation and return zero.
220 unsigned MipsMCCodeEmitter::
221 getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
222                        SmallVectorImpl<MCFixup> &Fixups,
223                        const MCSubtargetInfo &STI) const {
224 
225   const MCOperand &MO = MI.getOperand(OpNo);
226 
227   // If the destination is an immediate, divide by 4.
228   if (MO.isImm()) return MO.getImm() >> 2;
229 
230   assert(MO.isExpr() &&
231          "getBranchTargetOpValue expects only expressions or immediates");
232 
233   const MCExpr *FixupExpression = MCBinaryExpr::createAdd(
234       MO.getExpr(), MCConstantExpr::create(-4, Ctx), Ctx);
235   Fixups.push_back(MCFixup::create(0, FixupExpression,
236                                    MCFixupKind(Mips::fixup_Mips_PC16)));
237   return 0;
238 }
239 
240 /// getBranchTarget7OpValueMM - Return binary encoding of the microMIPS branch
241 /// target operand. If the machine operand requires relocation,
242 /// record the relocation and return zero.
243 unsigned MipsMCCodeEmitter::
244 getBranchTarget7OpValueMM(const MCInst &MI, unsigned OpNo,
245                           SmallVectorImpl<MCFixup> &Fixups,
246                           const MCSubtargetInfo &STI) const {
247 
248   const MCOperand &MO = MI.getOperand(OpNo);
249 
250   // If the destination is an immediate, divide by 2.
251   if (MO.isImm()) return MO.getImm() >> 1;
252 
253   assert(MO.isExpr() &&
254          "getBranchTargetOpValueMM expects only expressions or immediates");
255 
256   const MCExpr *Expr = MO.getExpr();
257   Fixups.push_back(MCFixup::create(0, Expr,
258                                    MCFixupKind(Mips::fixup_MICROMIPS_PC7_S1)));
259   return 0;
260 }
261 
262 /// getBranchTargetOpValueMMPC10 - Return binary encoding of the microMIPS
263 /// 10-bit branch target operand. If the machine operand requires relocation,
264 /// record the relocation and return zero.
265 unsigned MipsMCCodeEmitter::
266 getBranchTargetOpValueMMPC10(const MCInst &MI, unsigned OpNo,
267                              SmallVectorImpl<MCFixup> &Fixups,
268                              const MCSubtargetInfo &STI) const {
269 
270   const MCOperand &MO = MI.getOperand(OpNo);
271 
272   // If the destination is an immediate, divide by 2.
273   if (MO.isImm()) return MO.getImm() >> 1;
274 
275   assert(MO.isExpr() &&
276          "getBranchTargetOpValuePC10 expects only expressions or immediates");
277 
278   const MCExpr *Expr = MO.getExpr();
279   Fixups.push_back(MCFixup::create(0, Expr,
280                    MCFixupKind(Mips::fixup_MICROMIPS_PC10_S1)));
281   return 0;
282 }
283 
284 /// getBranchTargetOpValue - Return binary encoding of the microMIPS branch
285 /// target operand. If the machine operand requires relocation,
286 /// record the relocation and return zero.
287 unsigned MipsMCCodeEmitter::
288 getBranchTargetOpValueMM(const MCInst &MI, unsigned OpNo,
289                          SmallVectorImpl<MCFixup> &Fixups,
290                          const MCSubtargetInfo &STI) const {
291 
292   const MCOperand &MO = MI.getOperand(OpNo);
293 
294   // If the destination is an immediate, divide by 2.
295   if (MO.isImm()) return MO.getImm() >> 1;
296 
297   assert(MO.isExpr() &&
298          "getBranchTargetOpValueMM expects only expressions or immediates");
299 
300   const MCExpr *Expr = MO.getExpr();
301   Fixups.push_back(MCFixup::create(0, Expr,
302                    MCFixupKind(Mips::
303                                fixup_MICROMIPS_PC16_S1)));
304   return 0;
305 }
306 
307 /// getBranchTarget21OpValue - Return binary encoding of the branch
308 /// target operand. If the machine operand requires relocation,
309 /// record the relocation and return zero.
310 unsigned MipsMCCodeEmitter::
311 getBranchTarget21OpValue(const MCInst &MI, unsigned OpNo,
312                          SmallVectorImpl<MCFixup> &Fixups,
313                          const MCSubtargetInfo &STI) const {
314 
315   const MCOperand &MO = MI.getOperand(OpNo);
316 
317   // If the destination is an immediate, divide by 4.
318   if (MO.isImm()) return MO.getImm() >> 2;
319 
320   assert(MO.isExpr() &&
321          "getBranchTarget21OpValue expects only expressions or immediates");
322 
323   const MCExpr *FixupExpression = MCBinaryExpr::createAdd(
324       MO.getExpr(), MCConstantExpr::create(-4, Ctx), Ctx);
325   Fixups.push_back(MCFixup::create(0, FixupExpression,
326                                    MCFixupKind(Mips::fixup_MIPS_PC21_S2)));
327   return 0;
328 }
329 
330 /// getBranchTarget26OpValue - Return binary encoding of the branch
331 /// target operand. If the machine operand requires relocation,
332 /// record the relocation and return zero.
333 unsigned MipsMCCodeEmitter::
334 getBranchTarget26OpValue(const MCInst &MI, unsigned OpNo,
335                          SmallVectorImpl<MCFixup> &Fixups,
336                          const MCSubtargetInfo &STI) const {
337 
338   const MCOperand &MO = MI.getOperand(OpNo);
339 
340   // If the destination is an immediate, divide by 4.
341   if (MO.isImm()) return MO.getImm() >> 2;
342 
343   assert(MO.isExpr() &&
344          "getBranchTarget26OpValue expects only expressions or immediates");
345 
346   const MCExpr *FixupExpression = MCBinaryExpr::createAdd(
347       MO.getExpr(), MCConstantExpr::create(-4, Ctx), Ctx);
348   Fixups.push_back(MCFixup::create(0, FixupExpression,
349                                    MCFixupKind(Mips::fixup_MIPS_PC26_S2)));
350   return 0;
351 }
352 
353 /// getJumpOffset16OpValue - Return binary encoding of the jump
354 /// target operand. If the machine operand requires relocation,
355 /// record the relocation and return zero.
356 unsigned MipsMCCodeEmitter::
357 getJumpOffset16OpValue(const MCInst &MI, unsigned OpNo,
358                        SmallVectorImpl<MCFixup> &Fixups,
359                        const MCSubtargetInfo &STI) const {
360 
361   const MCOperand &MO = MI.getOperand(OpNo);
362 
363   if (MO.isImm()) return MO.getImm();
364 
365   assert(MO.isExpr() &&
366          "getJumpOffset16OpValue expects only expressions or an immediate");
367 
368    // TODO: Push fixup.
369    return 0;
370 }
371 
372 /// getJumpTargetOpValue - Return binary encoding of the jump
373 /// target operand. If the machine operand requires relocation,
374 /// record the relocation and return zero.
375 unsigned MipsMCCodeEmitter::
376 getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
377                      SmallVectorImpl<MCFixup> &Fixups,
378                      const MCSubtargetInfo &STI) const {
379 
380   const MCOperand &MO = MI.getOperand(OpNo);
381   // If the destination is an immediate, divide by 4.
382   if (MO.isImm()) return MO.getImm()>>2;
383 
384   assert(MO.isExpr() &&
385          "getJumpTargetOpValue expects only expressions or an immediate");
386 
387   const MCExpr *Expr = MO.getExpr();
388   Fixups.push_back(MCFixup::create(0, Expr,
389                                    MCFixupKind(Mips::fixup_Mips_26)));
390   return 0;
391 }
392 
393 unsigned MipsMCCodeEmitter::
394 getJumpTargetOpValueMM(const MCInst &MI, unsigned OpNo,
395                        SmallVectorImpl<MCFixup> &Fixups,
396                        const MCSubtargetInfo &STI) const {
397 
398   const MCOperand &MO = MI.getOperand(OpNo);
399   // If the destination is an immediate, divide by 2.
400   if (MO.isImm()) return MO.getImm() >> 1;
401 
402   assert(MO.isExpr() &&
403          "getJumpTargetOpValueMM expects only expressions or an immediate");
404 
405   const MCExpr *Expr = MO.getExpr();
406   Fixups.push_back(MCFixup::create(0, Expr,
407                                    MCFixupKind(Mips::fixup_MICROMIPS_26_S1)));
408   return 0;
409 }
410 
411 unsigned MipsMCCodeEmitter::
412 getUImm5Lsl2Encoding(const MCInst &MI, unsigned OpNo,
413                      SmallVectorImpl<MCFixup> &Fixups,
414                      const MCSubtargetInfo &STI) const {
415 
416   const MCOperand &MO = MI.getOperand(OpNo);
417   if (MO.isImm()) {
418     // The immediate is encoded as 'immediate << 2'.
419     unsigned Res = getMachineOpValue(MI, MO, Fixups, STI);
420     assert((Res & 3) == 0);
421     return Res >> 2;
422   }
423 
424   assert(MO.isExpr() &&
425          "getUImm5Lsl2Encoding expects only expressions or an immediate");
426 
427   return 0;
428 }
429 
430 unsigned MipsMCCodeEmitter::
431 getSImm3Lsa2Value(const MCInst &MI, unsigned OpNo,
432                   SmallVectorImpl<MCFixup> &Fixups,
433                   const MCSubtargetInfo &STI) const {
434 
435   const MCOperand &MO = MI.getOperand(OpNo);
436   if (MO.isImm()) {
437     int Value = MO.getImm();
438     return Value >> 2;
439   }
440 
441   return 0;
442 }
443 
444 unsigned MipsMCCodeEmitter::
445 getUImm6Lsl2Encoding(const MCInst &MI, unsigned OpNo,
446                      SmallVectorImpl<MCFixup> &Fixups,
447                      const MCSubtargetInfo &STI) const {
448 
449   const MCOperand &MO = MI.getOperand(OpNo);
450   if (MO.isImm()) {
451     unsigned Value = MO.getImm();
452     return Value >> 2;
453   }
454 
455   return 0;
456 }
457 
458 unsigned MipsMCCodeEmitter::
459 getSImm9AddiuspValue(const MCInst &MI, unsigned OpNo,
460                      SmallVectorImpl<MCFixup> &Fixups,
461                      const MCSubtargetInfo &STI) const {
462 
463   const MCOperand &MO = MI.getOperand(OpNo);
464   if (MO.isImm()) {
465     unsigned Binary = (MO.getImm() >> 2) & 0x0000ffff;
466     return (((Binary & 0x8000) >> 7) | (Binary & 0x00ff));
467   }
468 
469   return 0;
470 }
471 
472 unsigned MipsMCCodeEmitter::
473 getExprOpValue(const MCExpr *Expr, SmallVectorImpl<MCFixup> &Fixups,
474                const MCSubtargetInfo &STI) const {
475   int64_t Res;
476 
477   if (Expr->evaluateAsAbsolute(Res))
478     return Res;
479 
480   MCExpr::ExprKind Kind = Expr->getKind();
481   if (Kind == MCExpr::Constant) {
482     return cast<MCConstantExpr>(Expr)->getValue();
483   }
484 
485   if (Kind == MCExpr::Binary) {
486     unsigned Res = getExprOpValue(cast<MCBinaryExpr>(Expr)->getLHS(), Fixups, STI);
487     Res += getExprOpValue(cast<MCBinaryExpr>(Expr)->getRHS(), Fixups, STI);
488     return Res;
489   }
490 
491   if (Kind == MCExpr::Target) {
492     const MipsMCExpr *MipsExpr = cast<MipsMCExpr>(Expr);
493 
494     Mips::Fixups FixupKind = Mips::Fixups(0);
495     switch (MipsExpr->getKind()) {
496     default: llvm_unreachable("Unsupported fixup kind for target expression!");
497     case MipsMCExpr::VK_Mips_HIGHEST:
498       FixupKind = Mips::fixup_Mips_HIGHEST;
499       break;
500     case MipsMCExpr::VK_Mips_HIGHER:
501       FixupKind = Mips::fixup_Mips_HIGHER;
502       break;
503     case MipsMCExpr::VK_Mips_HI:
504       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_HI16
505                                    : Mips::fixup_Mips_HI16;
506       break;
507     case MipsMCExpr::VK_Mips_LO:
508       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_LO16
509                                    : Mips::fixup_Mips_LO16;
510       break;
511     }
512     Fixups.push_back(MCFixup::create(0, MipsExpr, MCFixupKind(FixupKind)));
513     return 0;
514   }
515 
516   if (Kind == MCExpr::SymbolRef) {
517     Mips::Fixups FixupKind = Mips::Fixups(0);
518 
519     switch(cast<MCSymbolRefExpr>(Expr)->getKind()) {
520     default: llvm_unreachable("Unknown fixup kind!");
521       break;
522     case MCSymbolRefExpr::VK_None:
523       FixupKind = Mips::fixup_Mips_32; // FIXME: This is ok for O32/N32 but not N64.
524       break;
525     case MCSymbolRefExpr::VK_Mips_GPOFF_HI :
526       FixupKind = Mips::fixup_Mips_GPOFF_HI;
527       break;
528     case MCSymbolRefExpr::VK_Mips_GPOFF_LO :
529       FixupKind = Mips::fixup_Mips_GPOFF_LO;
530       break;
531     case MCSymbolRefExpr::VK_Mips_GOT_PAGE :
532       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_GOT_PAGE
533                               : Mips::fixup_Mips_GOT_PAGE;
534       break;
535     case MCSymbolRefExpr::VK_Mips_GOT_OFST :
536       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_GOT_OFST
537                               : Mips::fixup_Mips_GOT_OFST;
538       break;
539     case MCSymbolRefExpr::VK_Mips_GOT_DISP :
540       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_GOT_DISP
541                               : Mips::fixup_Mips_GOT_DISP;
542       break;
543     case MCSymbolRefExpr::VK_Mips_GPREL:
544       FixupKind = Mips::fixup_Mips_GPREL16;
545       break;
546     case MCSymbolRefExpr::VK_Mips_GOT_CALL:
547       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_CALL16
548                               : Mips::fixup_Mips_CALL16;
549       break;
550     case MCSymbolRefExpr::VK_Mips_GOT16:
551       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_GOT16
552                               : Mips::fixup_Mips_GOT_Global;
553       break;
554     case MCSymbolRefExpr::VK_Mips_GOT:
555       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_GOT16
556                               : Mips::fixup_Mips_GOT_Local;
557       break;
558     case MCSymbolRefExpr::VK_Mips_ABS_HI:
559       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_HI16
560                               : Mips::fixup_Mips_HI16;
561       break;
562     case MCSymbolRefExpr::VK_Mips_ABS_LO:
563       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_LO16
564                               : Mips::fixup_Mips_LO16;
565       break;
566     case MCSymbolRefExpr::VK_Mips_TLSGD:
567       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_TLS_GD
568                               : Mips::fixup_Mips_TLSGD;
569       break;
570     case MCSymbolRefExpr::VK_Mips_TLSLDM:
571       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_TLS_LDM
572                               : Mips::fixup_Mips_TLSLDM;
573       break;
574     case MCSymbolRefExpr::VK_Mips_DTPREL_HI:
575       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_TLS_DTPREL_HI16
576                               : Mips::fixup_Mips_DTPREL_HI;
577       break;
578     case MCSymbolRefExpr::VK_Mips_DTPREL_LO:
579       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_TLS_DTPREL_LO16
580                               : Mips::fixup_Mips_DTPREL_LO;
581       break;
582     case MCSymbolRefExpr::VK_Mips_GOTTPREL:
583       FixupKind = Mips::fixup_Mips_GOTTPREL;
584       break;
585     case MCSymbolRefExpr::VK_Mips_TPREL_HI:
586       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_TLS_TPREL_HI16
587                               : Mips::fixup_Mips_TPREL_HI;
588       break;
589     case MCSymbolRefExpr::VK_Mips_TPREL_LO:
590       FixupKind = isMicroMips(STI) ? Mips::fixup_MICROMIPS_TLS_TPREL_LO16
591                               : Mips::fixup_Mips_TPREL_LO;
592       break;
593     case MCSymbolRefExpr::VK_Mips_HIGHER:
594       FixupKind = Mips::fixup_Mips_HIGHER;
595       break;
596     case MCSymbolRefExpr::VK_Mips_HIGHEST:
597       FixupKind = Mips::fixup_Mips_HIGHEST;
598       break;
599     case MCSymbolRefExpr::VK_Mips_GOT_HI16:
600       FixupKind = Mips::fixup_Mips_GOT_HI16;
601       break;
602     case MCSymbolRefExpr::VK_Mips_GOT_LO16:
603       FixupKind = Mips::fixup_Mips_GOT_LO16;
604       break;
605     case MCSymbolRefExpr::VK_Mips_CALL_HI16:
606       FixupKind = Mips::fixup_Mips_CALL_HI16;
607       break;
608     case MCSymbolRefExpr::VK_Mips_CALL_LO16:
609       FixupKind = Mips::fixup_Mips_CALL_LO16;
610       break;
611     case MCSymbolRefExpr::VK_Mips_PCREL_HI16:
612       FixupKind = Mips::fixup_MIPS_PCHI16;
613       break;
614     case MCSymbolRefExpr::VK_Mips_PCREL_LO16:
615       FixupKind = Mips::fixup_MIPS_PCLO16;
616       break;
617     } // switch
618 
619     Fixups.push_back(MCFixup::create(0, Expr, MCFixupKind(FixupKind)));
620     return 0;
621   }
622   return 0;
623 }
624 
625 /// getMachineOpValue - Return binary encoding of operand. If the machine
626 /// operand requires relocation, record the relocation and return zero.
627 unsigned MipsMCCodeEmitter::
628 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
629                   SmallVectorImpl<MCFixup> &Fixups,
630                   const MCSubtargetInfo &STI) const {
631   if (MO.isReg()) {
632     unsigned Reg = MO.getReg();
633     unsigned RegNo = Ctx.getRegisterInfo()->getEncodingValue(Reg);
634     return RegNo;
635   } else if (MO.isImm()) {
636     return static_cast<unsigned>(MO.getImm());
637   } else if (MO.isFPImm()) {
638     return static_cast<unsigned>(APFloat(MO.getFPImm())
639         .bitcastToAPInt().getHiBits(32).getLimitedValue());
640   }
641   // MO must be an Expr.
642   assert(MO.isExpr());
643   return getExprOpValue(MO.getExpr(),Fixups, STI);
644 }
645 
646 /// getMSAMemEncoding - Return binary encoding of memory operand for LD/ST
647 /// instructions.
648 unsigned
649 MipsMCCodeEmitter::getMSAMemEncoding(const MCInst &MI, unsigned OpNo,
650                                      SmallVectorImpl<MCFixup> &Fixups,
651                                      const MCSubtargetInfo &STI) const {
652   // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
653   assert(MI.getOperand(OpNo).isReg());
654   unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups, STI) << 16;
655   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI);
656 
657   // The immediate field of an LD/ST instruction is scaled which means it must
658   // be divided (when encoding) by the size (in bytes) of the instructions'
659   // data format.
660   // .b - 1 byte
661   // .h - 2 bytes
662   // .w - 4 bytes
663   // .d - 8 bytes
664   switch(MI.getOpcode())
665   {
666   default:
667     assert (0 && "Unexpected instruction");
668     break;
669   case Mips::LD_B:
670   case Mips::ST_B:
671     // We don't need to scale the offset in this case
672     break;
673   case Mips::LD_H:
674   case Mips::ST_H:
675     OffBits >>= 1;
676     break;
677   case Mips::LD_W:
678   case Mips::ST_W:
679     OffBits >>= 2;
680     break;
681   case Mips::LD_D:
682   case Mips::ST_D:
683     OffBits >>= 3;
684     break;
685   }
686 
687   return (OffBits & 0xFFFF) | RegBits;
688 }
689 
690 /// getMemEncoding - Return binary encoding of memory related operand.
691 /// If the offset operand requires relocation, record the relocation.
692 unsigned
693 MipsMCCodeEmitter::getMemEncoding(const MCInst &MI, unsigned OpNo,
694                                   SmallVectorImpl<MCFixup> &Fixups,
695                                   const MCSubtargetInfo &STI) const {
696   // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
697   assert(MI.getOperand(OpNo).isReg());
698   unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups, STI) << 16;
699   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI);
700 
701   return (OffBits & 0xFFFF) | RegBits;
702 }
703 
704 unsigned MipsMCCodeEmitter::
705 getMemEncodingMMImm4(const MCInst &MI, unsigned OpNo,
706                      SmallVectorImpl<MCFixup> &Fixups,
707                      const MCSubtargetInfo &STI) const {
708   // Base register is encoded in bits 6-4, offset is encoded in bits 3-0.
709   assert(MI.getOperand(OpNo).isReg());
710   unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),
711                                        Fixups, STI) << 4;
712   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1),
713                                        Fixups, STI);
714 
715   return (OffBits & 0xF) | RegBits;
716 }
717 
718 unsigned MipsMCCodeEmitter::
719 getMemEncodingMMImm4Lsl1(const MCInst &MI, unsigned OpNo,
720                          SmallVectorImpl<MCFixup> &Fixups,
721                          const MCSubtargetInfo &STI) const {
722   // Base register is encoded in bits 6-4, offset is encoded in bits 3-0.
723   assert(MI.getOperand(OpNo).isReg());
724   unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),
725                                        Fixups, STI) << 4;
726   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1),
727                                        Fixups, STI) >> 1;
728 
729   return (OffBits & 0xF) | RegBits;
730 }
731 
732 unsigned MipsMCCodeEmitter::
733 getMemEncodingMMImm4Lsl2(const MCInst &MI, unsigned OpNo,
734                          SmallVectorImpl<MCFixup> &Fixups,
735                          const MCSubtargetInfo &STI) const {
736   // Base register is encoded in bits 6-4, offset is encoded in bits 3-0.
737   assert(MI.getOperand(OpNo).isReg());
738   unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),
739                                        Fixups, STI) << 4;
740   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1),
741                                        Fixups, STI) >> 2;
742 
743   return (OffBits & 0xF) | RegBits;
744 }
745 
746 unsigned MipsMCCodeEmitter::
747 getMemEncodingMMSPImm5Lsl2(const MCInst &MI, unsigned OpNo,
748                            SmallVectorImpl<MCFixup> &Fixups,
749                            const MCSubtargetInfo &STI) const {
750   // Register is encoded in bits 9-5, offset is encoded in bits 4-0.
751   assert(MI.getOperand(OpNo).isReg() &&
752          (MI.getOperand(OpNo).getReg() == Mips::SP ||
753          MI.getOperand(OpNo).getReg() == Mips::SP_64) &&
754          "Unexpected base register!");
755   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1),
756                                        Fixups, STI) >> 2;
757 
758   return OffBits & 0x1F;
759 }
760 
761 unsigned MipsMCCodeEmitter::
762 getMemEncodingMMGPImm7Lsl2(const MCInst &MI, unsigned OpNo,
763                            SmallVectorImpl<MCFixup> &Fixups,
764                            const MCSubtargetInfo &STI) const {
765   // Register is encoded in bits 9-7, offset is encoded in bits 6-0.
766   assert(MI.getOperand(OpNo).isReg() &&
767          MI.getOperand(OpNo).getReg() == Mips::GP &&
768          "Unexpected base register!");
769 
770   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1),
771                                        Fixups, STI) >> 2;
772 
773   return OffBits & 0x7F;
774 }
775 
776  unsigned MipsMCCodeEmitter::
777 getMemEncodingMMImm9(const MCInst &MI, unsigned OpNo,
778                      SmallVectorImpl<MCFixup> &Fixups,
779                      const MCSubtargetInfo &STI) const {
780   // Base register is encoded in bits 20-16, offset is encoded in bits 8-0.
781   assert(MI.getOperand(OpNo).isReg());
782   unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups,
783                                        STI) << 16;
784   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo + 1), Fixups, STI);
785 
786   return (OffBits & 0x1FF) | RegBits;
787 }
788 
789 unsigned MipsMCCodeEmitter::
790 getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo,
791                       SmallVectorImpl<MCFixup> &Fixups,
792                       const MCSubtargetInfo &STI) const {
793   // opNum can be invalid if instruction had reglist as operand.
794   // MemOperand is always last operand of instruction (base + offset).
795   switch (MI.getOpcode()) {
796   default:
797     break;
798   case Mips::SWM32_MM:
799   case Mips::LWM32_MM:
800     OpNo = MI.getNumOperands() - 2;
801     break;
802   }
803 
804   // Base register is encoded in bits 20-16, offset is encoded in bits 11-0.
805   assert(MI.getOperand(OpNo).isReg());
806   unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups, STI) << 16;
807   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI);
808 
809   return (OffBits & 0x0FFF) | RegBits;
810 }
811 
812 unsigned MipsMCCodeEmitter::
813 getMemEncodingMMImm4sp(const MCInst &MI, unsigned OpNo,
814                        SmallVectorImpl<MCFixup> &Fixups,
815                        const MCSubtargetInfo &STI) const {
816   // opNum can be invalid if instruction had reglist as operand
817   // MemOperand is always last operand of instruction (base + offset)
818   switch (MI.getOpcode()) {
819   default:
820     break;
821   case Mips::SWM16_MM:
822   case Mips::LWM16_MM:
823     OpNo = MI.getNumOperands() - 2;
824     break;
825   }
826 
827   // Offset is encoded in bits 4-0.
828   assert(MI.getOperand(OpNo).isReg());
829   // Base register is always SP - thus it is not encoded.
830   assert(MI.getOperand(OpNo+1).isImm());
831   unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI);
832 
833   return ((OffBits >> 2) & 0x0F);
834 }
835 
836 unsigned
837 MipsMCCodeEmitter::getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
838                                       SmallVectorImpl<MCFixup> &Fixups,
839                                       const MCSubtargetInfo &STI) const {
840   assert(MI.getOperand(OpNo).isImm());
841   unsigned SizeEncoding = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups, STI);
842   return SizeEncoding - 1;
843 }
844 
845 // FIXME: should be called getMSBEncoding
846 //
847 unsigned
848 MipsMCCodeEmitter::getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
849                                       SmallVectorImpl<MCFixup> &Fixups,
850                                       const MCSubtargetInfo &STI) const {
851   assert(MI.getOperand(OpNo-1).isImm());
852   assert(MI.getOperand(OpNo).isImm());
853   unsigned Position = getMachineOpValue(MI, MI.getOperand(OpNo-1), Fixups, STI);
854   unsigned Size = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups, STI);
855 
856   return Position + Size - 1;
857 }
858 
859 unsigned
860 MipsMCCodeEmitter::getLSAImmEncoding(const MCInst &MI, unsigned OpNo,
861                                      SmallVectorImpl<MCFixup> &Fixups,
862                                      const MCSubtargetInfo &STI) const {
863   assert(MI.getOperand(OpNo).isImm());
864   // The immediate is encoded as 'immediate - 1'.
865   return getMachineOpValue(MI, MI.getOperand(OpNo), Fixups, STI) - 1;
866 }
867 
868 unsigned
869 MipsMCCodeEmitter::getSimm19Lsl2Encoding(const MCInst &MI, unsigned OpNo,
870                                          SmallVectorImpl<MCFixup> &Fixups,
871                                          const MCSubtargetInfo &STI) const {
872   const MCOperand &MO = MI.getOperand(OpNo);
873   if (MO.isImm()) {
874     // The immediate is encoded as 'immediate << 2'.
875     unsigned Res = getMachineOpValue(MI, MO, Fixups, STI);
876     assert((Res & 3) == 0);
877     return Res >> 2;
878   }
879 
880   assert(MO.isExpr() &&
881          "getSimm19Lsl2Encoding expects only expressions or an immediate");
882 
883   const MCExpr *Expr = MO.getExpr();
884   Fixups.push_back(MCFixup::create(0, Expr,
885                                    MCFixupKind(Mips::fixup_MIPS_PC19_S2)));
886   return 0;
887 }
888 
889 unsigned
890 MipsMCCodeEmitter::getSimm18Lsl3Encoding(const MCInst &MI, unsigned OpNo,
891                                          SmallVectorImpl<MCFixup> &Fixups,
892                                          const MCSubtargetInfo &STI) const {
893   const MCOperand &MO = MI.getOperand(OpNo);
894   if (MO.isImm()) {
895     // The immediate is encoded as 'immediate << 3'.
896     unsigned Res = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups, STI);
897     assert((Res & 7) == 0);
898     return Res >> 3;
899   }
900 
901   assert(MO.isExpr() &&
902          "getSimm18Lsl2Encoding expects only expressions or an immediate");
903 
904   const MCExpr *Expr = MO.getExpr();
905   Fixups.push_back(MCFixup::create(0, Expr,
906                                    MCFixupKind(Mips::fixup_MIPS_PC18_S3)));
907   return 0;
908 }
909 
910 unsigned
911 MipsMCCodeEmitter::getUImm3Mod8Encoding(const MCInst &MI, unsigned OpNo,
912                                         SmallVectorImpl<MCFixup> &Fixups,
913                                         const MCSubtargetInfo &STI) const {
914   assert(MI.getOperand(OpNo).isImm());
915   const MCOperand &MO = MI.getOperand(OpNo);
916   return MO.getImm() % 8;
917 }
918 
919 unsigned
920 MipsMCCodeEmitter::getUImm4AndValue(const MCInst &MI, unsigned OpNo,
921                                     SmallVectorImpl<MCFixup> &Fixups,
922                                     const MCSubtargetInfo &STI) const {
923   assert(MI.getOperand(OpNo).isImm());
924   const MCOperand &MO = MI.getOperand(OpNo);
925   unsigned Value = MO.getImm();
926   switch (Value) {
927     case 128:   return 0x0;
928     case 1:     return 0x1;
929     case 2:     return 0x2;
930     case 3:     return 0x3;
931     case 4:     return 0x4;
932     case 7:     return 0x5;
933     case 8:     return 0x6;
934     case 15:    return 0x7;
935     case 16:    return 0x8;
936     case 31:    return 0x9;
937     case 32:    return 0xa;
938     case 63:    return 0xb;
939     case 64:    return 0xc;
940     case 255:   return 0xd;
941     case 32768: return 0xe;
942     case 65535: return 0xf;
943   }
944   llvm_unreachable("Unexpected value");
945 }
946 
947 unsigned
948 MipsMCCodeEmitter::getRegisterListOpValue(const MCInst &MI, unsigned OpNo,
949                                           SmallVectorImpl<MCFixup> &Fixups,
950                                           const MCSubtargetInfo &STI) const {
951   unsigned res = 0;
952 
953   // Register list operand is always first operand of instruction and it is
954   // placed before memory operand (register + imm).
955 
956   for (unsigned I = OpNo, E = MI.getNumOperands() - 2; I < E; ++I) {
957     unsigned Reg = MI.getOperand(I).getReg();
958     unsigned RegNo = Ctx.getRegisterInfo()->getEncodingValue(Reg);
959     if (RegNo != 31)
960       res++;
961     else
962       res |= 0x10;
963   }
964   return res;
965 }
966 
967 unsigned
968 MipsMCCodeEmitter::getRegisterListOpValue16(const MCInst &MI, unsigned OpNo,
969                                             SmallVectorImpl<MCFixup> &Fixups,
970                                             const MCSubtargetInfo &STI) const {
971   return (MI.getNumOperands() - 4);
972 }
973 
974 unsigned
975 MipsMCCodeEmitter::getRegisterPairOpValue(const MCInst &MI, unsigned OpNo,
976                                           SmallVectorImpl<MCFixup> &Fixups,
977                                           const MCSubtargetInfo &STI) const {
978   return getMachineOpValue(MI, MI.getOperand(OpNo), Fixups, STI);
979 }
980 
981 unsigned
982 MipsMCCodeEmitter::getMovePRegPairOpValue(const MCInst &MI, unsigned OpNo,
983                                           SmallVectorImpl<MCFixup> &Fixups,
984                                           const MCSubtargetInfo &STI) const {
985   unsigned res = 0;
986 
987   if (MI.getOperand(0).getReg() == Mips::A1 &&
988       MI.getOperand(1).getReg() == Mips::A2)
989     res = 0;
990   else if (MI.getOperand(0).getReg() == Mips::A1 &&
991            MI.getOperand(1).getReg() == Mips::A3)
992     res = 1;
993   else if (MI.getOperand(0).getReg() == Mips::A2 &&
994            MI.getOperand(1).getReg() == Mips::A3)
995     res = 2;
996   else if (MI.getOperand(0).getReg() == Mips::A0 &&
997            MI.getOperand(1).getReg() == Mips::S5)
998     res = 3;
999   else if (MI.getOperand(0).getReg() == Mips::A0 &&
1000            MI.getOperand(1).getReg() == Mips::S6)
1001     res = 4;
1002   else if (MI.getOperand(0).getReg() == Mips::A0 &&
1003            MI.getOperand(1).getReg() == Mips::A1)
1004     res = 5;
1005   else if (MI.getOperand(0).getReg() == Mips::A0 &&
1006            MI.getOperand(1).getReg() == Mips::A2)
1007     res = 6;
1008   else if (MI.getOperand(0).getReg() == Mips::A0 &&
1009            MI.getOperand(1).getReg() == Mips::A3)
1010     res = 7;
1011 
1012   return res;
1013 }
1014 
1015 unsigned
1016 MipsMCCodeEmitter::getSimm23Lsl2Encoding(const MCInst &MI, unsigned OpNo,
1017                                          SmallVectorImpl<MCFixup> &Fixups,
1018                                          const MCSubtargetInfo &STI) const {
1019   const MCOperand &MO = MI.getOperand(OpNo);
1020   assert(MO.isImm() && "getSimm23Lsl2Encoding expects only an immediate");
1021   // The immediate is encoded as 'immediate >> 2'.
1022   unsigned Res = static_cast<unsigned>(MO.getImm());
1023   assert((Res & 3) == 0);
1024   return Res >> 2;
1025 }
1026 
1027 #include "MipsGenMCCodeEmitter.inc"
1028