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) const;
76 // getBinaryCodeForInstr - TableGen'erated function for getting the
77 // binary encoding for an instruction.
78 uint64_t getBinaryCodeForInstr(const MCInst &MI,
79 SmallVectorImpl<MCFixup> &Fixups) const;
81 // getBranchJumpOpValue - Return binary encoding of the jump
82 // target operand. If the machine operand requires relocation,
83 // record the relocation and return zero.
84 unsigned getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
85 SmallVectorImpl<MCFixup> &Fixups) const;
87 // getBranchTargetOpValue - Return binary encoding of the branch
88 // target operand. If the machine operand requires relocation,
89 // record the relocation and return zero.
90 unsigned getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
91 SmallVectorImpl<MCFixup> &Fixups) const;
93 // getMachineOpValue - Return binary encoding of operand. If the machin
94 // operand requires relocation, record the relocation and return zero.
95 unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
96 SmallVectorImpl<MCFixup> &Fixups) const;
98 unsigned getMemEncoding(const MCInst &MI, unsigned OpNo,
99 SmallVectorImpl<MCFixup> &Fixups) const;
100 unsigned getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo,
101 SmallVectorImpl<MCFixup> &Fixups) const;
102 unsigned getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
103 SmallVectorImpl<MCFixup> &Fixups) const;
104 unsigned getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
105 SmallVectorImpl<MCFixup> &Fixups) const;
108 getExprOpValue(const MCExpr *Expr,SmallVectorImpl<MCFixup> &Fixups) const;
110 }; // class MipsMCCodeEmitter
113 MCCodeEmitter *llvm::createMipsMCCodeEmitterEB(const MCInstrInfo &MCII,
114 const MCRegisterInfo &MRI,
115 const MCSubtargetInfo &STI,
118 return new MipsMCCodeEmitter(MCII, Ctx, STI, false);
121 MCCodeEmitter *llvm::createMipsMCCodeEmitterEL(const MCInstrInfo &MCII,
122 const MCRegisterInfo &MRI,
123 const MCSubtargetInfo &STI,
126 return new MipsMCCodeEmitter(MCII, Ctx, STI, true);
130 // If the D<shift> instruction has a shift amount that is greater
131 // than 31 (checked in calling routine), lower it to a D<shift>32 instruction
132 static void LowerLargeShift(MCInst& Inst) {
134 assert(Inst.getNumOperands() == 3 && "Invalid no. of operands for shift!");
135 assert(Inst.getOperand(2).isImm());
137 int64_t Shift = Inst.getOperand(2).getImm();
139 return; // Do nothing
143 Inst.getOperand(2).setImm(Shift);
145 switch (Inst.getOpcode()) {
147 // Calling function is not synchronized
148 llvm_unreachable("Unexpected shift instruction");
150 Inst.setOpcode(Mips::DSLL32);
153 Inst.setOpcode(Mips::DSRL32);
156 Inst.setOpcode(Mips::DSRA32);
161 // Pick a DEXT or DINS instruction variant based on the pos and size operands
162 static void LowerDextDins(MCInst& InstIn) {
163 int Opcode = InstIn.getOpcode();
165 if (Opcode == Mips::DEXT)
166 assert(InstIn.getNumOperands() == 4 &&
167 "Invalid no. of machine operands for DEXT!");
168 else // Only DEXT and DINS are possible
169 assert(InstIn.getNumOperands() == 5 &&
170 "Invalid no. of machine operands for DINS!");
172 assert(InstIn.getOperand(2).isImm());
173 int64_t pos = InstIn.getOperand(2).getImm();
174 assert(InstIn.getOperand(3).isImm());
175 int64_t size = InstIn.getOperand(3).getImm();
178 if (pos < 32) // DEXT/DINS, do nothing
181 InstIn.getOperand(2).setImm(pos - 32);
182 InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTU : Mips::DINSU);
186 assert(pos < 32 && "DEXT/DINS cannot have both size and pos > 32");
187 InstIn.getOperand(3).setImm(size - 32);
188 InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTM : Mips::DINSM);
192 /// EncodeInstruction - Emit the instruction.
193 /// Size the instruction with Desc.getSize().
194 void MipsMCCodeEmitter::
195 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
196 SmallVectorImpl<MCFixup> &Fixups) const
199 // Non-pseudo instructions that get changed for direct object
200 // only based on operand values.
201 // If this list of instructions get much longer we will move
202 // the check to a function call. Until then, this is more efficient.
204 switch (MI.getOpcode()) {
205 // If shift amount is >= 32 it the inst needs to be lowered further
209 LowerLargeShift(TmpInst);
211 // Double extract instruction is chosen by pos and size operands
214 LowerDextDins(TmpInst);
217 unsigned long N = Fixups.size();
218 uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups);
220 // Check for unimplemented opcodes.
221 // Unfortunately in MIPS both NOP and SLL will come in with Binary == 0
222 // so we have to special check for them.
223 unsigned Opcode = TmpInst.getOpcode();
224 if ((Opcode != Mips::NOP) && (Opcode != Mips::SLL) && !Binary)
225 llvm_unreachable("unimplemented opcode in EncodeInstruction()");
227 if (STI.getFeatureBits() & Mips::FeatureMicroMips) {
228 int NewOpcode = Mips::Std2MicroMips (Opcode, Mips::Arch_micromips);
229 if (NewOpcode != -1) {
230 if (Fixups.size() > N)
233 TmpInst.setOpcode (NewOpcode);
234 Binary = getBinaryCodeForInstr(TmpInst, Fixups);
238 const MCInstrDesc &Desc = MCII.get(TmpInst.getOpcode());
240 // Get byte count of instruction
241 unsigned Size = Desc.getSize();
243 llvm_unreachable("Desc.getSize() returns 0");
245 EmitInstruction(Binary, Size, OS);
248 /// getBranchTargetOpValue - Return binary encoding of the branch
249 /// target operand. If the machine operand requires relocation,
250 /// record the relocation and return zero.
251 unsigned MipsMCCodeEmitter::
252 getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
253 SmallVectorImpl<MCFixup> &Fixups) const {
255 const MCOperand &MO = MI.getOperand(OpNo);
257 // If the destination is an immediate, divide by 4.
258 if (MO.isImm()) return MO.getImm() >> 2;
260 assert(MO.isExpr() &&
261 "getBranchTargetOpValue expects only expressions or immediates");
263 const MCExpr *Expr = MO.getExpr();
264 Fixups.push_back(MCFixup::Create(0, Expr,
265 MCFixupKind(Mips::fixup_Mips_PC16)));
269 /// getJumpTargetOpValue - Return binary encoding of the jump
270 /// target operand. If the machine operand requires relocation,
271 /// record the relocation and return zero.
272 unsigned MipsMCCodeEmitter::
273 getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
274 SmallVectorImpl<MCFixup> &Fixups) const {
276 const MCOperand &MO = MI.getOperand(OpNo);
277 // If the destination is an immediate, divide by 4.
278 if (MO.isImm()) return MO.getImm()>>2;
280 assert(MO.isExpr() &&
281 "getJumpTargetOpValue expects only expressions or an immediate");
283 const MCExpr *Expr = MO.getExpr();
284 Fixups.push_back(MCFixup::Create(0, Expr,
285 MCFixupKind(Mips::fixup_Mips_26)));
289 unsigned MipsMCCodeEmitter::
290 getExprOpValue(const MCExpr *Expr,SmallVectorImpl<MCFixup> &Fixups) const {
293 if (Expr->EvaluateAsAbsolute(Res))
296 MCExpr::ExprKind Kind = Expr->getKind();
297 if (Kind == MCExpr::Constant) {
298 return cast<MCConstantExpr>(Expr)->getValue();
301 if (Kind == MCExpr::Binary) {
302 unsigned Res = getExprOpValue(cast<MCBinaryExpr>(Expr)->getLHS(), Fixups);
303 Res += getExprOpValue(cast<MCBinaryExpr>(Expr)->getRHS(), Fixups);
306 if (Kind == MCExpr::SymbolRef) {
307 Mips::Fixups FixupKind = Mips::Fixups(0);
309 switch(cast<MCSymbolRefExpr>(Expr)->getKind()) {
310 default: llvm_unreachable("Unknown fixup kind!");
312 case MCSymbolRefExpr::VK_Mips_GPOFF_HI :
313 FixupKind = Mips::fixup_Mips_GPOFF_HI;
315 case MCSymbolRefExpr::VK_Mips_GPOFF_LO :
316 FixupKind = Mips::fixup_Mips_GPOFF_LO;
318 case MCSymbolRefExpr::VK_Mips_GOT_PAGE :
319 FixupKind = Mips::fixup_Mips_GOT_PAGE;
321 case MCSymbolRefExpr::VK_Mips_GOT_OFST :
322 FixupKind = Mips::fixup_Mips_GOT_OFST;
324 case MCSymbolRefExpr::VK_Mips_GOT_DISP :
325 FixupKind = Mips::fixup_Mips_GOT_DISP;
327 case MCSymbolRefExpr::VK_Mips_GPREL:
328 FixupKind = Mips::fixup_Mips_GPREL16;
330 case MCSymbolRefExpr::VK_Mips_GOT_CALL:
331 FixupKind = Mips::fixup_Mips_CALL16;
333 case MCSymbolRefExpr::VK_Mips_GOT16:
334 FixupKind = Mips::fixup_Mips_GOT_Global;
336 case MCSymbolRefExpr::VK_Mips_GOT:
337 FixupKind = Mips::fixup_Mips_GOT_Local;
339 case MCSymbolRefExpr::VK_Mips_ABS_HI:
340 FixupKind = Mips::fixup_Mips_HI16;
342 case MCSymbolRefExpr::VK_Mips_ABS_LO:
343 FixupKind = Mips::fixup_Mips_LO16;
345 case MCSymbolRefExpr::VK_Mips_TLSGD:
346 FixupKind = Mips::fixup_Mips_TLSGD;
348 case MCSymbolRefExpr::VK_Mips_TLSLDM:
349 FixupKind = Mips::fixup_Mips_TLSLDM;
351 case MCSymbolRefExpr::VK_Mips_DTPREL_HI:
352 FixupKind = Mips::fixup_Mips_DTPREL_HI;
354 case MCSymbolRefExpr::VK_Mips_DTPREL_LO:
355 FixupKind = Mips::fixup_Mips_DTPREL_LO;
357 case MCSymbolRefExpr::VK_Mips_GOTTPREL:
358 FixupKind = Mips::fixup_Mips_GOTTPREL;
360 case MCSymbolRefExpr::VK_Mips_TPREL_HI:
361 FixupKind = Mips::fixup_Mips_TPREL_HI;
363 case MCSymbolRefExpr::VK_Mips_TPREL_LO:
364 FixupKind = Mips::fixup_Mips_TPREL_LO;
366 case MCSymbolRefExpr::VK_Mips_HIGHER:
367 FixupKind = Mips::fixup_Mips_HIGHER;
369 case MCSymbolRefExpr::VK_Mips_HIGHEST:
370 FixupKind = Mips::fixup_Mips_HIGHEST;
372 case MCSymbolRefExpr::VK_Mips_GOT_HI16:
373 FixupKind = Mips::fixup_Mips_GOT_HI16;
375 case MCSymbolRefExpr::VK_Mips_GOT_LO16:
376 FixupKind = Mips::fixup_Mips_GOT_LO16;
378 case MCSymbolRefExpr::VK_Mips_CALL_HI16:
379 FixupKind = Mips::fixup_Mips_CALL_HI16;
381 case MCSymbolRefExpr::VK_Mips_CALL_LO16:
382 FixupKind = Mips::fixup_Mips_CALL_LO16;
386 Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(FixupKind)));
392 /// getMachineOpValue - Return binary encoding of operand. If the machine
393 /// operand requires relocation, record the relocation and return zero.
394 unsigned MipsMCCodeEmitter::
395 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
396 SmallVectorImpl<MCFixup> &Fixups) const {
398 unsigned Reg = MO.getReg();
399 unsigned RegNo = Ctx.getRegisterInfo()->getEncodingValue(Reg);
401 } else if (MO.isImm()) {
402 return static_cast<unsigned>(MO.getImm());
403 } else if (MO.isFPImm()) {
404 return static_cast<unsigned>(APFloat(MO.getFPImm())
405 .bitcastToAPInt().getHiBits(32).getLimitedValue());
407 // MO must be an Expr.
409 return getExprOpValue(MO.getExpr(),Fixups);
412 /// getMemEncoding - Return binary encoding of memory related operand.
413 /// If the offset operand requires relocation, record the relocation.
415 MipsMCCodeEmitter::getMemEncoding(const MCInst &MI, unsigned OpNo,
416 SmallVectorImpl<MCFixup> &Fixups) const {
417 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
418 assert(MI.getOperand(OpNo).isReg());
419 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups) << 16;
420 unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups);
422 return (OffBits & 0xFFFF) | RegBits;
425 unsigned MipsMCCodeEmitter::
426 getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo,
427 SmallVectorImpl<MCFixup> &Fixups) const {
428 // Base register is encoded in bits 20-16, offset is encoded in bits 11-0.
429 assert(MI.getOperand(OpNo).isReg());
430 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups) << 16;
431 unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups);
433 return (OffBits & 0x0FFF) | RegBits;
437 MipsMCCodeEmitter::getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
438 SmallVectorImpl<MCFixup> &Fixups) const {
439 assert(MI.getOperand(OpNo).isImm());
440 unsigned SizeEncoding = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
441 return SizeEncoding - 1;
444 // FIXME: should be called getMSBEncoding
447 MipsMCCodeEmitter::getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
448 SmallVectorImpl<MCFixup> &Fixups) const {
449 assert(MI.getOperand(OpNo-1).isImm());
450 assert(MI.getOperand(OpNo).isImm());
451 unsigned Position = getMachineOpValue(MI, MI.getOperand(OpNo-1), Fixups);
452 unsigned Size = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
454 return Position + Size - 1;
457 #include "MipsGenMCCodeEmitter.inc"