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/MCExpr.h"
22 #include "llvm/MC/MCInst.h"
23 #include "llvm/MC/MCInstrInfo.h"
24 #include "llvm/MC/MCRegisterInfo.h"
25 #include "llvm/MC/MCSubtargetInfo.h"
26 #include "llvm/Support/raw_ostream.h"
31 class MipsMCCodeEmitter : public MCCodeEmitter {
32 MipsMCCodeEmitter(const MipsMCCodeEmitter &); // DO NOT IMPLEMENT
33 void operator=(const MipsMCCodeEmitter &); // DO NOT IMPLEMENT
34 const MCInstrInfo &MCII;
35 const MCSubtargetInfo &STI;
40 MipsMCCodeEmitter(const MCInstrInfo &mcii, const MCSubtargetInfo &sti,
41 MCContext &ctx, bool IsLittle) :
42 MCII(mcii), STI(sti) , Ctx(ctx), IsLittleEndian(IsLittle) {}
44 ~MipsMCCodeEmitter() {}
46 void EmitByte(unsigned char C, raw_ostream &OS) const {
50 void EmitInstruction(uint64_t Val, unsigned Size, raw_ostream &OS) const {
51 // Output the instruction encoding in little endian byte order.
52 for (unsigned i = 0; i < Size; ++i) {
53 unsigned Shift = IsLittleEndian ? i * 8 : (Size - 1 - i) * 8;
54 EmitByte((Val >> Shift) & 0xff, OS);
58 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
59 SmallVectorImpl<MCFixup> &Fixups) const;
61 // getBinaryCodeForInstr - TableGen'erated function for getting the
62 // binary encoding for an instruction.
63 uint64_t getBinaryCodeForInstr(const MCInst &MI,
64 SmallVectorImpl<MCFixup> &Fixups) const;
66 // getBranchJumpOpValue - Return binary encoding of the jump
67 // target operand. If the machine operand requires relocation,
68 // record the relocation and return zero.
69 unsigned getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
70 SmallVectorImpl<MCFixup> &Fixups) const;
72 // getBranchTargetOpValue - Return binary encoding of the branch
73 // target operand. If the machine operand requires relocation,
74 // record the relocation and return zero.
75 unsigned getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
76 SmallVectorImpl<MCFixup> &Fixups) const;
78 // getMachineOpValue - Return binary encoding of operand. If the machin
79 // operand requires relocation, record the relocation and return zero.
80 unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
81 SmallVectorImpl<MCFixup> &Fixups) const;
83 unsigned getMemEncoding(const MCInst &MI, unsigned OpNo,
84 SmallVectorImpl<MCFixup> &Fixups) const;
85 unsigned getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
86 SmallVectorImpl<MCFixup> &Fixups) const;
87 unsigned getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
88 SmallVectorImpl<MCFixup> &Fixups) const;
90 }; // class MipsMCCodeEmitter
93 MCCodeEmitter *llvm::createMipsMCCodeEmitterEB(const MCInstrInfo &MCII,
94 const MCRegisterInfo &MRI,
95 const MCSubtargetInfo &STI,
98 return new MipsMCCodeEmitter(MCII, STI, Ctx, false);
101 MCCodeEmitter *llvm::createMipsMCCodeEmitterEL(const MCInstrInfo &MCII,
102 const MCRegisterInfo &MRI,
103 const MCSubtargetInfo &STI,
106 return new MipsMCCodeEmitter(MCII, STI, Ctx, true);
109 /// EncodeInstruction - Emit the instruction.
110 /// Size the instruction (currently only 4 bytes
111 void MipsMCCodeEmitter::
112 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
113 SmallVectorImpl<MCFixup> &Fixups) const
115 uint32_t Binary = getBinaryCodeForInstr(MI, Fixups);
117 // Check for unimplemented opcodes.
118 // Unfortunately in MIPS both NOT and SLL will come in with Binary == 0
119 // so we have to special check for them.
120 unsigned Opcode = MI.getOpcode();
121 if ((Opcode != Mips::NOP) && (Opcode != Mips::SLL) && !Binary)
122 llvm_unreachable("unimplemented opcode in EncodeInstruction()");
124 const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
125 uint64_t TSFlags = Desc.TSFlags;
127 // Pseudo instructions don't get encoded and shouldn't be here
128 // in the first place!
129 if ((TSFlags & MipsII::FormMask) == MipsII::Pseudo)
130 llvm_unreachable("Pseudo opcode found in EncodeInstruction()");
132 // For now all instructions are 4 bytes
133 int Size = 4; // FIXME: Have Desc.getSize() return the correct value!
135 EmitInstruction(Binary, Size, OS);
138 /// getBranchTargetOpValue - Return binary encoding of the branch
139 /// target operand. If the machine operand requires relocation,
140 /// record the relocation and return zero.
141 unsigned MipsMCCodeEmitter::
142 getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
143 SmallVectorImpl<MCFixup> &Fixups) const {
145 const MCOperand &MO = MI.getOperand(OpNo);
146 assert(MO.isExpr() && "getBranchTargetOpValue expects only expressions");
148 const MCExpr *Expr = MO.getExpr();
149 Fixups.push_back(MCFixup::Create(0, Expr,
150 MCFixupKind(Mips::fixup_Mips_PC16)));
154 /// getJumpTargetOpValue - Return binary encoding of the jump
155 /// target operand. If the machine operand requires relocation,
156 /// record the relocation and return zero.
157 unsigned MipsMCCodeEmitter::
158 getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
159 SmallVectorImpl<MCFixup> &Fixups) const {
161 const MCOperand &MO = MI.getOperand(OpNo);
162 assert(MO.isExpr() && "getJumpTargetOpValue expects only expressions");
164 const MCExpr *Expr = MO.getExpr();
165 Fixups.push_back(MCFixup::Create(0, Expr,
166 MCFixupKind(Mips::fixup_Mips_26)));
170 /// getMachineOpValue - Return binary encoding of operand. If the machine
171 /// operand requires relocation, record the relocation and return zero.
172 unsigned MipsMCCodeEmitter::
173 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
174 SmallVectorImpl<MCFixup> &Fixups) const {
176 unsigned Reg = MO.getReg();
177 unsigned RegNo = getMipsRegisterNumbering(Reg);
179 } else if (MO.isImm()) {
180 return static_cast<unsigned>(MO.getImm());
181 } else if (MO.isFPImm()) {
182 return static_cast<unsigned>(APFloat(MO.getFPImm())
183 .bitcastToAPInt().getHiBits(32).getLimitedValue());
186 // MO must be an Expr.
189 const MCExpr *Expr = MO.getExpr();
190 MCExpr::ExprKind Kind = Expr->getKind();
192 if (Kind == MCExpr::Binary) {
193 Expr = static_cast<const MCBinaryExpr*>(Expr)->getLHS();
194 Kind = Expr->getKind();
197 assert (Kind == MCExpr::SymbolRef);
199 Mips::Fixups FixupKind = Mips::Fixups(0);
201 switch(cast<MCSymbolRefExpr>(Expr)->getKind()) {
202 case MCSymbolRefExpr::VK_Mips_GPREL:
203 FixupKind = Mips::fixup_Mips_GPREL16;
205 case MCSymbolRefExpr::VK_Mips_GOT_CALL:
206 FixupKind = Mips::fixup_Mips_CALL16;
208 case MCSymbolRefExpr::VK_Mips_GOT16:
209 FixupKind = Mips::fixup_Mips_GOT_Global;
211 case MCSymbolRefExpr::VK_Mips_GOT:
212 FixupKind = Mips::fixup_Mips_GOT_Local;
214 case MCSymbolRefExpr::VK_Mips_ABS_HI:
215 FixupKind = Mips::fixup_Mips_HI16;
217 case MCSymbolRefExpr::VK_Mips_ABS_LO:
218 FixupKind = Mips::fixup_Mips_LO16;
220 case MCSymbolRefExpr::VK_Mips_TLSGD:
221 FixupKind = Mips::fixup_Mips_TLSGD;
223 case MCSymbolRefExpr::VK_Mips_TLSLDM:
224 FixupKind = Mips::fixup_Mips_TLSLDM;
226 case MCSymbolRefExpr::VK_Mips_DTPREL_HI:
227 FixupKind = Mips::fixup_Mips_DTPREL_HI;
229 case MCSymbolRefExpr::VK_Mips_DTPREL_LO:
230 FixupKind = Mips::fixup_Mips_DTPREL_LO;
232 case MCSymbolRefExpr::VK_Mips_GOTTPREL:
233 FixupKind = Mips::fixup_Mips_GOTTPREL;
235 case MCSymbolRefExpr::VK_Mips_TPREL_HI:
236 FixupKind = Mips::fixup_Mips_TPREL_HI;
238 case MCSymbolRefExpr::VK_Mips_TPREL_LO:
239 FixupKind = Mips::fixup_Mips_TPREL_LO;
245 Fixups.push_back(MCFixup::Create(0, MO.getExpr(), MCFixupKind(FixupKind)));
247 // All of the information is in the fixup.
251 /// getMemEncoding - Return binary encoding of memory related operand.
252 /// If the offset operand requires relocation, record the relocation.
254 MipsMCCodeEmitter::getMemEncoding(const MCInst &MI, unsigned OpNo,
255 SmallVectorImpl<MCFixup> &Fixups) const {
256 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
257 assert(MI.getOperand(OpNo).isReg());
258 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups) << 16;
259 unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups);
261 return (OffBits & 0xFFFF) | RegBits;
265 MipsMCCodeEmitter::getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
266 SmallVectorImpl<MCFixup> &Fixups) const {
267 assert(MI.getOperand(OpNo).isImm());
268 unsigned SizeEncoding = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
269 return SizeEncoding - 1;
272 // FIXME: should be called getMSBEncoding
275 MipsMCCodeEmitter::getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
276 SmallVectorImpl<MCFixup> &Fixups) const {
277 assert(MI.getOperand(OpNo-1).isImm());
278 assert(MI.getOperand(OpNo).isImm());
279 unsigned Position = getMachineOpValue(MI, MI.getOperand(OpNo-1), Fixups);
280 unsigned Size = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
282 return Position + Size - 1;
285 #include "MipsGenMCCodeEmitter.inc"