1 //===-- ARM/ARMMCCodeEmitter.cpp - Convert ARM 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 ARMMCCodeEmitter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "arm-emitter"
16 #include "ARMAddressingModes.h"
17 #include "ARMInstrInfo.h"
18 #include "llvm/MC/MCCodeEmitter.h"
19 #include "llvm/MC/MCExpr.h"
20 #include "llvm/MC/MCInst.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/Support/raw_ostream.h"
25 STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
28 class ARMMCCodeEmitter : public MCCodeEmitter {
29 ARMMCCodeEmitter(const ARMMCCodeEmitter &); // DO NOT IMPLEMENT
30 void operator=(const ARMMCCodeEmitter &); // DO NOT IMPLEMENT
31 const TargetMachine &TM;
32 const TargetInstrInfo &TII;
36 ARMMCCodeEmitter(TargetMachine &tm, MCContext &ctx)
37 : TM(tm), TII(*TM.getInstrInfo()), Ctx(ctx) {
40 ~ARMMCCodeEmitter() {}
42 unsigned getMachineSoImmOpValue(unsigned SoImm) const;
44 // getBinaryCodeForInstr - TableGen'erated function for getting the
45 // binary encoding for an instruction.
46 unsigned getBinaryCodeForInstr(const MCInst &MI) const;
48 /// getMachineOpValue - Return binary encoding of operand. If the machine
49 /// operand requires relocation, record the relocation and return zero.
50 unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO) const;
52 /// getCCOutOpValue - Return encoding of the 's' bit.
53 unsigned getCCOutOpValue(const MCInst &MI, unsigned Op) const {
54 // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
56 return MI.getOperand(Op).getReg() == ARM::CPSR;
59 /// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
60 unsigned getSOImmOpValue(const MCInst &MI, unsigned Op) const {
61 unsigned SoImm = MI.getOperand(Op).getImm();
62 int SoImmVal = ARM_AM::getSOImmVal(SoImm);
63 assert(SoImmVal != -1 && "Not a valid so_imm value!");
66 unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
67 << ARMII::SoRotImmShift;
70 Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
74 /// getSORegOpValue - Return an encoded so_reg shifted register value.
75 unsigned getSORegOpValue(const MCInst &MI, unsigned Op) const;
77 unsigned getRotImmOpValue(const MCInst &MI, unsigned Op) const {
78 switch (MI.getOperand(Op).getImm()) {
79 default: assert (0 && "Not a valid rot_imm value!");
87 unsigned getNumFixupKinds() const {
88 assert(0 && "ARMMCCodeEmitter::getNumFixupKinds() not yet implemented.");
92 const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
93 static MCFixupKindInfo rtn;
94 assert(0 && "ARMMCCodeEmitter::getFixupKindInfo() not yet implemented.");
98 void EmitByte(unsigned char C, unsigned &CurByte, raw_ostream &OS) const {
103 void EmitConstant(uint64_t Val, unsigned Size, unsigned &CurByte,
104 raw_ostream &OS) const {
105 // Output the constant in little endian byte order.
106 for (unsigned i = 0; i != Size; ++i) {
107 EmitByte(Val & 255, CurByte, OS);
112 void EmitImmediate(const MCOperand &Disp,
113 unsigned ImmSize, MCFixupKind FixupKind,
114 unsigned &CurByte, raw_ostream &OS,
115 SmallVectorImpl<MCFixup> &Fixups,
116 int ImmOffset = 0) const;
118 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
119 SmallVectorImpl<MCFixup> &Fixups) const;
122 } // end anonymous namespace
124 MCCodeEmitter *llvm::createARMMCCodeEmitter(const Target &,
127 return new ARMMCCodeEmitter(TM, Ctx);
130 void ARMMCCodeEmitter::
131 EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
132 unsigned &CurByte, raw_ostream &OS,
133 SmallVectorImpl<MCFixup> &Fixups, int ImmOffset) const {
134 assert(0 && "ARMMCCodeEmitter::EmitImmediate() not yet implemented.");
137 /// getMachineOpValue - Return binary encoding of operand. If the machine
138 /// operand requires relocation, record the relocation and return zero.
139 unsigned ARMMCCodeEmitter::getMachineOpValue(const MCInst &MI,
140 const MCOperand &MO) const {
142 return getARMRegisterNumbering(MO.getReg());
143 else if (MO.isImm()) {
144 return static_cast<unsigned>(MO.getImm());
155 unsigned ARMMCCodeEmitter::getSORegOpValue(const MCInst &MI,
156 unsigned OpIdx) const {
157 // Sub-operands are [reg, reg, imm]. The first register is Rm, the reg
158 // to be shifted. The second is either Rs, the amount to shift by, or
159 // reg0 in which case the imm contains the amount to shift by.
161 // {4} = 1 if reg shift, 0 if imm shift
169 const MCOperand &MO = MI.getOperand(OpIdx);
170 const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
171 const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
172 ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
175 unsigned Binary = getARMRegisterNumbering(MO.getReg());
177 // Encode the shift opcode.
179 unsigned Rs = MO1.getReg();
181 // Set shift operand (bit[7:4]).
186 // RRX - 0110 and bit[11:8] clear.
188 default: llvm_unreachable("Unknown shift opc!");
189 case ARM_AM::lsl: SBits = 0x1; break;
190 case ARM_AM::lsr: SBits = 0x3; break;
191 case ARM_AM::asr: SBits = 0x5; break;
192 case ARM_AM::ror: SBits = 0x7; break;
193 case ARM_AM::rrx: SBits = 0x6; break;
196 // Set shift operand (bit[6:4]).
202 default: llvm_unreachable("Unknown shift opc!");
203 case ARM_AM::lsl: SBits = 0x0; break;
204 case ARM_AM::lsr: SBits = 0x2; break;
205 case ARM_AM::asr: SBits = 0x4; break;
206 case ARM_AM::ror: SBits = 0x6; break;
209 Binary |= SBits << 4;
210 if (SOpc == ARM_AM::rrx)
213 // Encode the shift operation Rs or shift_imm (except rrx).
215 // Encode Rs bit[11:8].
216 assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
217 return Binary | (getARMRegisterNumbering(Rs) << ARMII::RegRsShift);
220 // Encode shift_imm bit[11:7].
221 return Binary | ARM_AM::getSORegOffset(MO2.getImm()) << 7;
224 void ARMMCCodeEmitter::
225 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
226 SmallVectorImpl<MCFixup> &Fixups) const {
227 unsigned Opcode = MI.getOpcode();
228 const TargetInstrDesc &Desc = TII.get(Opcode);
229 uint64_t TSFlags = Desc.TSFlags;
230 // Keep track of the current byte being emitted.
231 unsigned CurByte = 0;
233 // Pseudo instructions don't get encoded.
234 if ((TSFlags & ARMII::FormMask) == ARMII::Pseudo)
237 ++MCNumEmitted; // Keep track of the # of mi's emitted
238 unsigned Value = getBinaryCodeForInstr(MI);
242 EmitConstant(Value, 4, CurByte, OS);
245 // FIXME: These #defines shouldn't be necessary. Instead, tblgen should
246 // be able to generate code emitter helpers for either variant, like it
247 // does for the AsmWriter.
248 #define ARMCodeEmitter ARMMCCodeEmitter
249 #define MachineInstr MCInst
250 #include "ARMGenCodeEmitter.inc"
251 #undef ARMCodeEmitter