1 //===-- MipsMCCodeEmitter.cpp - Convert Mips Code to Machine Code ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the MipsMCCodeEmitter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "mccodeemitter"
15 #include "MCTargetDesc/MipsBaseInfo.h"
16 #include "MCTargetDesc/MipsFixupKinds.h"
17 #include "MCTargetDesc/MipsMCTargetDesc.h"
18 #include "llvm/ADT/APFloat.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/MC/MCCodeEmitter.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCExpr.h"
23 #include "llvm/MC/MCInst.h"
24 #include "llvm/MC/MCInstrInfo.h"
25 #include "llvm/MC/MCRegisterInfo.h"
26 #include "llvm/MC/MCSubtargetInfo.h"
27 #include "llvm/Support/raw_ostream.h"
29 #define GET_INSTRMAP_INFO
30 #include "MipsGenInstrInfo.inc"
35 class MipsMCCodeEmitter : public MCCodeEmitter {
36 MipsMCCodeEmitter(const MipsMCCodeEmitter &) LLVM_DELETED_FUNCTION;
37 void operator=(const MipsMCCodeEmitter &) LLVM_DELETED_FUNCTION;
38 const MCInstrInfo &MCII;
40 const MCSubtargetInfo &STI;
45 MipsMCCodeEmitter(const MCInstrInfo &mcii, MCContext &Ctx_,
46 const MCSubtargetInfo &sti, bool IsLittle) :
47 MCII(mcii), Ctx(Ctx_), STI (sti), IsLittleEndian(IsLittle) {
48 IsMicroMips = STI.getFeatureBits() & Mips::FeatureMicroMips;
51 ~MipsMCCodeEmitter() {}
53 void EmitByte(unsigned char C, raw_ostream &OS) const {
57 void EmitInstruction(uint64_t Val, unsigned Size, raw_ostream &OS) const {
58 // Output the instruction encoding in little endian byte order.
59 // Little-endian byte ordering:
60 // mips32r2: 4 | 3 | 2 | 1
61 // microMIPS: 2 | 1 | 4 | 3
62 if (IsLittleEndian && Size == 4 && IsMicroMips) {
63 EmitInstruction(Val>>16, 2, OS);
64 EmitInstruction(Val, 2, OS);
66 for (unsigned i = 0; i < Size; ++i) {
67 unsigned Shift = IsLittleEndian ? i * 8 : (Size - 1 - i) * 8;
68 EmitByte((Val >> Shift) & 0xff, OS);
73 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
74 SmallVectorImpl<MCFixup> &Fixups,
75 const MCSubtargetInfo &STI) const;
77 // getBinaryCodeForInstr - TableGen'erated function for getting the
78 // binary encoding for an instruction.
79 uint64_t getBinaryCodeForInstr(const MCInst &MI,
80 SmallVectorImpl<MCFixup> &Fixups) const;
82 // getBranchJumpOpValue - Return binary encoding of the jump
83 // target operand. If the machine operand requires relocation,
84 // record the relocation and return zero.
85 unsigned getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
86 SmallVectorImpl<MCFixup> &Fixups) const;
88 // getBranchJumpOpValueMM - Return binary encoding of the microMIPS jump
89 // target operand. If the machine operand requires relocation,
90 // record the relocation and return zero.
91 unsigned getJumpTargetOpValueMM(const MCInst &MI, unsigned OpNo,
92 SmallVectorImpl<MCFixup> &Fixups) const;
94 // getBranchTargetOpValue - Return binary encoding of the branch
95 // target operand. If the machine operand requires relocation,
96 // record the relocation and return zero.
97 unsigned getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
98 SmallVectorImpl<MCFixup> &Fixups) const;
100 // getBranchTargetOpValue - Return binary encoding of the microMIPS branch
101 // target operand. If the machine operand requires relocation,
102 // record the relocation and return zero.
103 unsigned getBranchTargetOpValueMM(const MCInst &MI, unsigned OpNo,
104 SmallVectorImpl<MCFixup> &Fixups) const;
106 // getMachineOpValue - Return binary encoding of operand. If the machin
107 // operand requires relocation, record the relocation and return zero.
108 unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
109 SmallVectorImpl<MCFixup> &Fixups) const;
111 unsigned getMSAMemEncoding(const MCInst &MI, unsigned OpNo,
112 SmallVectorImpl<MCFixup> &Fixups) const;
114 unsigned getMemEncoding(const MCInst &MI, unsigned OpNo,
115 SmallVectorImpl<MCFixup> &Fixups) const;
116 unsigned getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo,
117 SmallVectorImpl<MCFixup> &Fixups) const;
118 unsigned getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
119 SmallVectorImpl<MCFixup> &Fixups) const;
120 unsigned getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
121 SmallVectorImpl<MCFixup> &Fixups) const;
123 // getLSAImmEncoding - Return binary encoding of LSA immediate.
124 unsigned getLSAImmEncoding(const MCInst &MI, unsigned OpNo,
125 SmallVectorImpl<MCFixup> &Fixups) const;
128 getExprOpValue(const MCExpr *Expr,SmallVectorImpl<MCFixup> &Fixups) const;
130 }; // class MipsMCCodeEmitter
133 MCCodeEmitter *llvm::createMipsMCCodeEmitterEB(const MCInstrInfo &MCII,
134 const MCRegisterInfo &MRI,
135 const MCSubtargetInfo &STI,
138 return new MipsMCCodeEmitter(MCII, Ctx, STI, false);
141 MCCodeEmitter *llvm::createMipsMCCodeEmitterEL(const MCInstrInfo &MCII,
142 const MCRegisterInfo &MRI,
143 const MCSubtargetInfo &STI,
146 return new MipsMCCodeEmitter(MCII, Ctx, STI, true);
150 // If the D<shift> instruction has a shift amount that is greater
151 // than 31 (checked in calling routine), lower it to a D<shift>32 instruction
152 static void LowerLargeShift(MCInst& Inst) {
154 assert(Inst.getNumOperands() == 3 && "Invalid no. of operands for shift!");
155 assert(Inst.getOperand(2).isImm());
157 int64_t Shift = Inst.getOperand(2).getImm();
159 return; // Do nothing
163 Inst.getOperand(2).setImm(Shift);
165 switch (Inst.getOpcode()) {
167 // Calling function is not synchronized
168 llvm_unreachable("Unexpected shift instruction");
170 Inst.setOpcode(Mips::DSLL32);
173 Inst.setOpcode(Mips::DSRL32);
176 Inst.setOpcode(Mips::DSRA32);
179 Inst.setOpcode(Mips::DROTR32);
184 // Pick a DEXT or DINS instruction variant based on the pos and size operands
185 static void LowerDextDins(MCInst& InstIn) {
186 int Opcode = InstIn.getOpcode();
188 if (Opcode == Mips::DEXT)
189 assert(InstIn.getNumOperands() == 4 &&
190 "Invalid no. of machine operands for DEXT!");
191 else // Only DEXT and DINS are possible
192 assert(InstIn.getNumOperands() == 5 &&
193 "Invalid no. of machine operands for DINS!");
195 assert(InstIn.getOperand(2).isImm());
196 int64_t pos = InstIn.getOperand(2).getImm();
197 assert(InstIn.getOperand(3).isImm());
198 int64_t size = InstIn.getOperand(3).getImm();
201 if (pos < 32) // DEXT/DINS, do nothing
204 InstIn.getOperand(2).setImm(pos - 32);
205 InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTU : Mips::DINSU);
209 assert(pos < 32 && "DEXT/DINS cannot have both size and pos > 32");
210 InstIn.getOperand(3).setImm(size - 32);
211 InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTM : Mips::DINSM);
215 /// EncodeInstruction - Emit the instruction.
216 /// Size the instruction with Desc.getSize().
217 void MipsMCCodeEmitter::
218 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
219 SmallVectorImpl<MCFixup> &Fixups,
220 const MCSubtargetInfo &STI) const
223 // Non-pseudo instructions that get changed for direct object
224 // only based on operand values.
225 // If this list of instructions get much longer we will move
226 // the check to a function call. Until then, this is more efficient.
228 switch (MI.getOpcode()) {
229 // If shift amount is >= 32 it the inst needs to be lowered further
234 LowerLargeShift(TmpInst);
236 // Double extract instruction is chosen by pos and size operands
239 LowerDextDins(TmpInst);
242 unsigned long N = Fixups.size();
243 uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups);
245 // Check for unimplemented opcodes.
246 // Unfortunately in MIPS both NOP and SLL will come in with Binary == 0
247 // so we have to special check for them.
248 unsigned Opcode = TmpInst.getOpcode();
249 if ((Opcode != Mips::NOP) && (Opcode != Mips::SLL) && !Binary)
250 llvm_unreachable("unimplemented opcode in EncodeInstruction()");
252 if (STI.getFeatureBits() & Mips::FeatureMicroMips) {
253 int NewOpcode = Mips::Std2MicroMips (Opcode, Mips::Arch_micromips);
254 if (NewOpcode != -1) {
255 if (Fixups.size() > N)
258 TmpInst.setOpcode (NewOpcode);
259 Binary = getBinaryCodeForInstr(TmpInst, Fixups);
263 const MCInstrDesc &Desc = MCII.get(TmpInst.getOpcode());
265 // Get byte count of instruction
266 unsigned Size = Desc.getSize();
268 llvm_unreachable("Desc.getSize() returns 0");
270 EmitInstruction(Binary, Size, OS);
273 /// getBranchTargetOpValue - Return binary encoding of the branch
274 /// target operand. If the machine operand requires relocation,
275 /// record the relocation and return zero.
276 unsigned MipsMCCodeEmitter::
277 getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
278 SmallVectorImpl<MCFixup> &Fixups) const {
280 const MCOperand &MO = MI.getOperand(OpNo);
282 // If the destination is an immediate, divide by 4.
283 if (MO.isImm()) return MO.getImm() >> 2;
285 assert(MO.isExpr() &&
286 "getBranchTargetOpValue expects only expressions or immediates");
288 const MCExpr *Expr = MO.getExpr();
289 Fixups.push_back(MCFixup::Create(0, Expr,
290 MCFixupKind(Mips::fixup_Mips_PC16)));
294 /// getBranchTargetOpValue - Return binary encoding of the microMIPS branch
295 /// target operand. If the machine operand requires relocation,
296 /// record the relocation and return zero.
297 unsigned MipsMCCodeEmitter::
298 getBranchTargetOpValueMM(const MCInst &MI, unsigned OpNo,
299 SmallVectorImpl<MCFixup> &Fixups) const {
301 const MCOperand &MO = MI.getOperand(OpNo);
303 // If the destination is an immediate, divide by 2.
304 if (MO.isImm()) return MO.getImm() >> 1;
306 assert(MO.isExpr() &&
307 "getBranchTargetOpValueMM expects only expressions or immediates");
309 const MCExpr *Expr = MO.getExpr();
310 Fixups.push_back(MCFixup::Create(0, Expr,
312 fixup_MICROMIPS_PC16_S1)));
316 /// getJumpTargetOpValue - Return binary encoding of the jump
317 /// target operand. If the machine operand requires relocation,
318 /// record the relocation and return zero.
319 unsigned MipsMCCodeEmitter::
320 getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
321 SmallVectorImpl<MCFixup> &Fixups) const {
323 const MCOperand &MO = MI.getOperand(OpNo);
324 // If the destination is an immediate, divide by 4.
325 if (MO.isImm()) return MO.getImm()>>2;
327 assert(MO.isExpr() &&
328 "getJumpTargetOpValue expects only expressions or an immediate");
330 const MCExpr *Expr = MO.getExpr();
331 Fixups.push_back(MCFixup::Create(0, Expr,
332 MCFixupKind(Mips::fixup_Mips_26)));
336 unsigned MipsMCCodeEmitter::
337 getJumpTargetOpValueMM(const MCInst &MI, unsigned OpNo,
338 SmallVectorImpl<MCFixup> &Fixups) const {
340 const MCOperand &MO = MI.getOperand(OpNo);
341 // If the destination is an immediate, divide by 2.
342 if (MO.isImm()) return MO.getImm() >> 1;
344 assert(MO.isExpr() &&
345 "getJumpTargetOpValueMM expects only expressions or an immediate");
347 const MCExpr *Expr = MO.getExpr();
348 Fixups.push_back(MCFixup::Create(0, Expr,
349 MCFixupKind(Mips::fixup_MICROMIPS_26_S1)));
353 unsigned MipsMCCodeEmitter::
354 getExprOpValue(const MCExpr *Expr,SmallVectorImpl<MCFixup> &Fixups) const {
357 if (Expr->EvaluateAsAbsolute(Res))
360 MCExpr::ExprKind Kind = Expr->getKind();
361 if (Kind == MCExpr::Constant) {
362 return cast<MCConstantExpr>(Expr)->getValue();
365 if (Kind == MCExpr::Binary) {
366 unsigned Res = getExprOpValue(cast<MCBinaryExpr>(Expr)->getLHS(), Fixups);
367 Res += getExprOpValue(cast<MCBinaryExpr>(Expr)->getRHS(), Fixups);
370 if (Kind == MCExpr::SymbolRef) {
371 Mips::Fixups FixupKind = Mips::Fixups(0);
373 switch(cast<MCSymbolRefExpr>(Expr)->getKind()) {
374 default: llvm_unreachable("Unknown fixup kind!");
376 case MCSymbolRefExpr::VK_Mips_GPOFF_HI :
377 FixupKind = Mips::fixup_Mips_GPOFF_HI;
379 case MCSymbolRefExpr::VK_Mips_GPOFF_LO :
380 FixupKind = Mips::fixup_Mips_GPOFF_LO;
382 case MCSymbolRefExpr::VK_Mips_GOT_PAGE :
383 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT_PAGE
384 : Mips::fixup_Mips_GOT_PAGE;
386 case MCSymbolRefExpr::VK_Mips_GOT_OFST :
387 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT_OFST
388 : Mips::fixup_Mips_GOT_OFST;
390 case MCSymbolRefExpr::VK_Mips_GOT_DISP :
391 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT_DISP
392 : Mips::fixup_Mips_GOT_DISP;
394 case MCSymbolRefExpr::VK_Mips_GPREL:
395 FixupKind = Mips::fixup_Mips_GPREL16;
397 case MCSymbolRefExpr::VK_Mips_GOT_CALL:
398 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_CALL16
399 : Mips::fixup_Mips_CALL16;
401 case MCSymbolRefExpr::VK_Mips_GOT16:
402 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT16
403 : Mips::fixup_Mips_GOT_Global;
405 case MCSymbolRefExpr::VK_Mips_GOT:
406 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT16
407 : Mips::fixup_Mips_GOT_Local;
409 case MCSymbolRefExpr::VK_Mips_ABS_HI:
410 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_HI16
411 : Mips::fixup_Mips_HI16;
413 case MCSymbolRefExpr::VK_Mips_ABS_LO:
414 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_LO16
415 : Mips::fixup_Mips_LO16;
417 case MCSymbolRefExpr::VK_Mips_TLSGD:
418 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_GD
419 : Mips::fixup_Mips_TLSGD;
421 case MCSymbolRefExpr::VK_Mips_TLSLDM:
422 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_LDM
423 : Mips::fixup_Mips_TLSLDM;
425 case MCSymbolRefExpr::VK_Mips_DTPREL_HI:
426 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_DTPREL_HI16
427 : Mips::fixup_Mips_DTPREL_HI;
429 case MCSymbolRefExpr::VK_Mips_DTPREL_LO:
430 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_DTPREL_LO16
431 : Mips::fixup_Mips_DTPREL_LO;
433 case MCSymbolRefExpr::VK_Mips_GOTTPREL:
434 FixupKind = Mips::fixup_Mips_GOTTPREL;
436 case MCSymbolRefExpr::VK_Mips_TPREL_HI:
437 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_TPREL_HI16
438 : Mips::fixup_Mips_TPREL_HI;
440 case MCSymbolRefExpr::VK_Mips_TPREL_LO:
441 FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_TPREL_LO16
442 : Mips::fixup_Mips_TPREL_LO;
444 case MCSymbolRefExpr::VK_Mips_HIGHER:
445 FixupKind = Mips::fixup_Mips_HIGHER;
447 case MCSymbolRefExpr::VK_Mips_HIGHEST:
448 FixupKind = Mips::fixup_Mips_HIGHEST;
450 case MCSymbolRefExpr::VK_Mips_GOT_HI16:
451 FixupKind = Mips::fixup_Mips_GOT_HI16;
453 case MCSymbolRefExpr::VK_Mips_GOT_LO16:
454 FixupKind = Mips::fixup_Mips_GOT_LO16;
456 case MCSymbolRefExpr::VK_Mips_CALL_HI16:
457 FixupKind = Mips::fixup_Mips_CALL_HI16;
459 case MCSymbolRefExpr::VK_Mips_CALL_LO16:
460 FixupKind = Mips::fixup_Mips_CALL_LO16;
464 Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(FixupKind)));
470 /// getMachineOpValue - Return binary encoding of operand. If the machine
471 /// operand requires relocation, record the relocation and return zero.
472 unsigned MipsMCCodeEmitter::
473 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
474 SmallVectorImpl<MCFixup> &Fixups) const {
476 unsigned Reg = MO.getReg();
477 unsigned RegNo = Ctx.getRegisterInfo()->getEncodingValue(Reg);
479 } else if (MO.isImm()) {
480 return static_cast<unsigned>(MO.getImm());
481 } else if (MO.isFPImm()) {
482 return static_cast<unsigned>(APFloat(MO.getFPImm())
483 .bitcastToAPInt().getHiBits(32).getLimitedValue());
485 // MO must be an Expr.
487 return getExprOpValue(MO.getExpr(),Fixups);
490 /// getMSAMemEncoding - Return binary encoding of memory operand for LD/ST
493 MipsMCCodeEmitter::getMSAMemEncoding(const MCInst &MI, unsigned OpNo,
494 SmallVectorImpl<MCFixup> &Fixups) const {
495 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
496 assert(MI.getOperand(OpNo).isReg());
497 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups) << 16;
498 unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups);
500 // The immediate field of an LD/ST instruction is scaled which means it must
501 // be divided (when encoding) by the size (in bytes) of the instructions'
507 switch(MI.getOpcode())
510 assert (0 && "Unexpected instruction");
514 // We don't need to scale the offset in this case
530 return (OffBits & 0xFFFF) | RegBits;
533 /// getMemEncoding - Return binary encoding of memory related operand.
534 /// If the offset operand requires relocation, record the relocation.
536 MipsMCCodeEmitter::getMemEncoding(const MCInst &MI, unsigned OpNo,
537 SmallVectorImpl<MCFixup> &Fixups) const {
538 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
539 assert(MI.getOperand(OpNo).isReg());
540 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups) << 16;
541 unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups);
543 return (OffBits & 0xFFFF) | RegBits;
546 unsigned MipsMCCodeEmitter::
547 getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo,
548 SmallVectorImpl<MCFixup> &Fixups) const {
549 // Base register is encoded in bits 20-16, offset is encoded in bits 11-0.
550 assert(MI.getOperand(OpNo).isReg());
551 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups) << 16;
552 unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups);
554 return (OffBits & 0x0FFF) | RegBits;
558 MipsMCCodeEmitter::getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
559 SmallVectorImpl<MCFixup> &Fixups) const {
560 assert(MI.getOperand(OpNo).isImm());
561 unsigned SizeEncoding = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
562 return SizeEncoding - 1;
565 // FIXME: should be called getMSBEncoding
568 MipsMCCodeEmitter::getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
569 SmallVectorImpl<MCFixup> &Fixups) const {
570 assert(MI.getOperand(OpNo-1).isImm());
571 assert(MI.getOperand(OpNo).isImm());
572 unsigned Position = getMachineOpValue(MI, MI.getOperand(OpNo-1), Fixups);
573 unsigned Size = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
575 return Position + Size - 1;
579 MipsMCCodeEmitter::getLSAImmEncoding(const MCInst &MI, unsigned OpNo,
580 SmallVectorImpl<MCFixup> &Fixups) const {
581 assert(MI.getOperand(OpNo).isImm());
582 // The immediate is encoded as 'immediate - 1'.
583 return getMachineOpValue(MI, MI.getOperand(OpNo), Fixups) - 1;
586 #include "MipsGenMCCodeEmitter.inc"