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 getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
101 SmallVectorImpl<MCFixup> &Fixups) const;
102 unsigned getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
103 SmallVectorImpl<MCFixup> &Fixups) const;
106 getExprOpValue(const MCExpr *Expr,SmallVectorImpl<MCFixup> &Fixups) const;
108 }; // class MipsMCCodeEmitter
111 MCCodeEmitter *llvm::createMipsMCCodeEmitterEB(const MCInstrInfo &MCII,
112 const MCRegisterInfo &MRI,
113 const MCSubtargetInfo &STI,
116 return new MipsMCCodeEmitter(MCII, Ctx, STI, false);
119 MCCodeEmitter *llvm::createMipsMCCodeEmitterEL(const MCInstrInfo &MCII,
120 const MCRegisterInfo &MRI,
121 const MCSubtargetInfo &STI,
124 return new MipsMCCodeEmitter(MCII, Ctx, STI, true);
128 // If the D<shift> instruction has a shift amount that is greater
129 // than 31 (checked in calling routine), lower it to a D<shift>32 instruction
130 static void LowerLargeShift(MCInst& Inst) {
132 assert(Inst.getNumOperands() == 3 && "Invalid no. of operands for shift!");
133 assert(Inst.getOperand(2).isImm());
135 int64_t Shift = Inst.getOperand(2).getImm();
137 return; // Do nothing
141 Inst.getOperand(2).setImm(Shift);
143 switch (Inst.getOpcode()) {
145 // Calling function is not synchronized
146 llvm_unreachable("Unexpected shift instruction");
148 Inst.setOpcode(Mips::DSLL32);
151 Inst.setOpcode(Mips::DSRL32);
154 Inst.setOpcode(Mips::DSRA32);
159 // Pick a DEXT or DINS instruction variant based on the pos and size operands
160 static void LowerDextDins(MCInst& InstIn) {
161 int Opcode = InstIn.getOpcode();
163 if (Opcode == Mips::DEXT)
164 assert(InstIn.getNumOperands() == 4 &&
165 "Invalid no. of machine operands for DEXT!");
166 else // Only DEXT and DINS are possible
167 assert(InstIn.getNumOperands() == 5 &&
168 "Invalid no. of machine operands for DINS!");
170 assert(InstIn.getOperand(2).isImm());
171 int64_t pos = InstIn.getOperand(2).getImm();
172 assert(InstIn.getOperand(3).isImm());
173 int64_t size = InstIn.getOperand(3).getImm();
176 if (pos < 32) // DEXT/DINS, do nothing
179 InstIn.getOperand(2).setImm(pos - 32);
180 InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTU : Mips::DINSU);
184 assert(pos < 32 && "DEXT/DINS cannot have both size and pos > 32");
185 InstIn.getOperand(3).setImm(size - 32);
186 InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTM : Mips::DINSM);
190 /// EncodeInstruction - Emit the instruction.
191 /// Size the instruction (currently only 4 bytes
192 void MipsMCCodeEmitter::
193 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
194 SmallVectorImpl<MCFixup> &Fixups) const
197 // Non-pseudo instructions that get changed for direct object
198 // only based on operand values.
199 // If this list of instructions get much longer we will move
200 // the check to a function call. Until then, this is more efficient.
202 switch (MI.getOpcode()) {
203 // If shift amount is >= 32 it the inst needs to be lowered further
207 LowerLargeShift(TmpInst);
209 // Double extract instruction is chosen by pos and size operands
212 LowerDextDins(TmpInst);
215 uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups);
217 // Check for unimplemented opcodes.
218 // Unfortunately in MIPS both NOP and SLL will come in with Binary == 0
219 // so we have to special check for them.
220 unsigned Opcode = TmpInst.getOpcode();
221 if ((Opcode != Mips::NOP) && (Opcode != Mips::SLL) && !Binary)
222 llvm_unreachable("unimplemented opcode in EncodeInstruction()");
224 if (STI.getFeatureBits() & Mips::FeatureMicroMips) {
225 int NewOpcode = Mips::Std2MicroMips (Opcode, Mips::Arch_micromips);
226 if (NewOpcode != -1) {
228 TmpInst.setOpcode (NewOpcode);
229 Binary = getBinaryCodeForInstr(TmpInst, Fixups);
233 const MCInstrDesc &Desc = MCII.get(TmpInst.getOpcode());
235 // Get byte count of instruction
236 unsigned Size = Desc.getSize();
238 llvm_unreachable("Desc.getSize() returns 0");
240 EmitInstruction(Binary, Size, OS);
243 /// getBranchTargetOpValue - Return binary encoding of the branch
244 /// target operand. If the machine operand requires relocation,
245 /// record the relocation and return zero.
246 unsigned MipsMCCodeEmitter::
247 getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
248 SmallVectorImpl<MCFixup> &Fixups) const {
250 const MCOperand &MO = MI.getOperand(OpNo);
252 // If the destination is an immediate, divide by 4.
253 if (MO.isImm()) return MO.getImm() >> 2;
255 assert(MO.isExpr() &&
256 "getBranchTargetOpValue expects only expressions or immediates");
258 const MCExpr *Expr = MO.getExpr();
259 Fixups.push_back(MCFixup::Create(0, Expr,
260 MCFixupKind(Mips::fixup_Mips_PC16)));
264 /// getJumpTargetOpValue - Return binary encoding of the jump
265 /// target operand. If the machine operand requires relocation,
266 /// record the relocation and return zero.
267 unsigned MipsMCCodeEmitter::
268 getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
269 SmallVectorImpl<MCFixup> &Fixups) const {
271 const MCOperand &MO = MI.getOperand(OpNo);
272 // If the destination is an immediate, divide by 4.
273 if (MO.isImm()) return MO.getImm()>>2;
275 assert(MO.isExpr() &&
276 "getJumpTargetOpValue expects only expressions or an immediate");
278 const MCExpr *Expr = MO.getExpr();
279 Fixups.push_back(MCFixup::Create(0, Expr,
280 MCFixupKind(Mips::fixup_Mips_26)));
284 unsigned MipsMCCodeEmitter::
285 getExprOpValue(const MCExpr *Expr,SmallVectorImpl<MCFixup> &Fixups) const {
288 if (Expr->EvaluateAsAbsolute(Res))
291 MCExpr::ExprKind Kind = Expr->getKind();
292 if (Kind == MCExpr::Constant) {
293 return cast<MCConstantExpr>(Expr)->getValue();
296 if (Kind == MCExpr::Binary) {
297 unsigned Res = getExprOpValue(cast<MCBinaryExpr>(Expr)->getLHS(), Fixups);
298 Res += getExprOpValue(cast<MCBinaryExpr>(Expr)->getRHS(), Fixups);
301 if (Kind == MCExpr::SymbolRef) {
302 Mips::Fixups FixupKind = Mips::Fixups(0);
304 switch(cast<MCSymbolRefExpr>(Expr)->getKind()) {
305 default: llvm_unreachable("Unknown fixup kind!");
307 case MCSymbolRefExpr::VK_Mips_GPOFF_HI :
308 FixupKind = Mips::fixup_Mips_GPOFF_HI;
310 case MCSymbolRefExpr::VK_Mips_GPOFF_LO :
311 FixupKind = Mips::fixup_Mips_GPOFF_LO;
313 case MCSymbolRefExpr::VK_Mips_GOT_PAGE :
314 FixupKind = Mips::fixup_Mips_GOT_PAGE;
316 case MCSymbolRefExpr::VK_Mips_GOT_OFST :
317 FixupKind = Mips::fixup_Mips_GOT_OFST;
319 case MCSymbolRefExpr::VK_Mips_GOT_DISP :
320 FixupKind = Mips::fixup_Mips_GOT_DISP;
322 case MCSymbolRefExpr::VK_Mips_GPREL:
323 FixupKind = Mips::fixup_Mips_GPREL16;
325 case MCSymbolRefExpr::VK_Mips_GOT_CALL:
326 FixupKind = Mips::fixup_Mips_CALL16;
328 case MCSymbolRefExpr::VK_Mips_GOT16:
329 FixupKind = Mips::fixup_Mips_GOT_Global;
331 case MCSymbolRefExpr::VK_Mips_GOT:
332 FixupKind = Mips::fixup_Mips_GOT_Local;
334 case MCSymbolRefExpr::VK_Mips_ABS_HI:
335 FixupKind = Mips::fixup_Mips_HI16;
337 case MCSymbolRefExpr::VK_Mips_ABS_LO:
338 FixupKind = Mips::fixup_Mips_LO16;
340 case MCSymbolRefExpr::VK_Mips_TLSGD:
341 FixupKind = Mips::fixup_Mips_TLSGD;
343 case MCSymbolRefExpr::VK_Mips_TLSLDM:
344 FixupKind = Mips::fixup_Mips_TLSLDM;
346 case MCSymbolRefExpr::VK_Mips_DTPREL_HI:
347 FixupKind = Mips::fixup_Mips_DTPREL_HI;
349 case MCSymbolRefExpr::VK_Mips_DTPREL_LO:
350 FixupKind = Mips::fixup_Mips_DTPREL_LO;
352 case MCSymbolRefExpr::VK_Mips_GOTTPREL:
353 FixupKind = Mips::fixup_Mips_GOTTPREL;
355 case MCSymbolRefExpr::VK_Mips_TPREL_HI:
356 FixupKind = Mips::fixup_Mips_TPREL_HI;
358 case MCSymbolRefExpr::VK_Mips_TPREL_LO:
359 FixupKind = Mips::fixup_Mips_TPREL_LO;
361 case MCSymbolRefExpr::VK_Mips_HIGHER:
362 FixupKind = Mips::fixup_Mips_HIGHER;
364 case MCSymbolRefExpr::VK_Mips_HIGHEST:
365 FixupKind = Mips::fixup_Mips_HIGHEST;
367 case MCSymbolRefExpr::VK_Mips_GOT_HI16:
368 FixupKind = Mips::fixup_Mips_GOT_HI16;
370 case MCSymbolRefExpr::VK_Mips_GOT_LO16:
371 FixupKind = Mips::fixup_Mips_GOT_LO16;
373 case MCSymbolRefExpr::VK_Mips_CALL_HI16:
374 FixupKind = Mips::fixup_Mips_CALL_HI16;
376 case MCSymbolRefExpr::VK_Mips_CALL_LO16:
377 FixupKind = Mips::fixup_Mips_CALL_LO16;
381 Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(FixupKind)));
387 /// getMachineOpValue - Return binary encoding of operand. If the machine
388 /// operand requires relocation, record the relocation and return zero.
389 unsigned MipsMCCodeEmitter::
390 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
391 SmallVectorImpl<MCFixup> &Fixups) const {
393 unsigned Reg = MO.getReg();
394 unsigned RegNo = Ctx.getRegisterInfo()->getEncodingValue(Reg);
396 } else if (MO.isImm()) {
397 return static_cast<unsigned>(MO.getImm());
398 } else if (MO.isFPImm()) {
399 return static_cast<unsigned>(APFloat(MO.getFPImm())
400 .bitcastToAPInt().getHiBits(32).getLimitedValue());
402 // MO must be an Expr.
404 return getExprOpValue(MO.getExpr(),Fixups);
407 /// getMemEncoding - Return binary encoding of memory related operand.
408 /// If the offset operand requires relocation, record the relocation.
410 MipsMCCodeEmitter::getMemEncoding(const MCInst &MI, unsigned OpNo,
411 SmallVectorImpl<MCFixup> &Fixups) const {
412 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
413 assert(MI.getOperand(OpNo).isReg());
414 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups) << 16;
415 unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups);
417 return (OffBits & 0xFFFF) | RegBits;
421 MipsMCCodeEmitter::getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
422 SmallVectorImpl<MCFixup> &Fixups) const {
423 assert(MI.getOperand(OpNo).isImm());
424 unsigned SizeEncoding = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
425 return SizeEncoding - 1;
428 // FIXME: should be called getMSBEncoding
431 MipsMCCodeEmitter::getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
432 SmallVectorImpl<MCFixup> &Fixups) const {
433 assert(MI.getOperand(OpNo-1).isImm());
434 assert(MI.getOperand(OpNo).isImm());
435 unsigned Position = getMachineOpValue(MI, MI.getOperand(OpNo-1), Fixups);
436 unsigned Size = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
438 return Position + Size - 1;
441 #include "MipsGenMCCodeEmitter.inc"