//===-- MipsMCCodeEmitter.cpp - Convert Mips Code to Machine Code ---------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements the MipsMCCodeEmitter class. // //===----------------------------------------------------------------------===// // #define DEBUG_TYPE "mccodeemitter" #include "MCTargetDesc/MipsBaseInfo.h" #include "MCTargetDesc/MipsFixupKinds.h" #include "MCTargetDesc/MipsMCTargetDesc.h" #include "llvm/ADT/APFloat.h" #include "llvm/ADT/Statistic.h" #include "llvm/MC/MCCodeEmitter.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCInst.h" #include "llvm/MC/MCInstrInfo.h" #include "llvm/MC/MCRegisterInfo.h" #include "llvm/MC/MCSubtargetInfo.h" #include "llvm/Support/raw_ostream.h" #define GET_INSTRMAP_INFO #include "MipsGenInstrInfo.inc" using namespace llvm; namespace { class MipsMCCodeEmitter : public MCCodeEmitter { MipsMCCodeEmitter(const MipsMCCodeEmitter &) LLVM_DELETED_FUNCTION; void operator=(const MipsMCCodeEmitter &) LLVM_DELETED_FUNCTION; const MCInstrInfo &MCII; MCContext &Ctx; const MCSubtargetInfo &STI; bool IsLittleEndian; bool IsMicroMips; public: MipsMCCodeEmitter(const MCInstrInfo &mcii, MCContext &Ctx_, const MCSubtargetInfo &sti, bool IsLittle) : MCII(mcii), Ctx(Ctx_), STI (sti), IsLittleEndian(IsLittle) { IsMicroMips = STI.getFeatureBits() & Mips::FeatureMicroMips; } ~MipsMCCodeEmitter() {} void EmitByte(unsigned char C, raw_ostream &OS) const { OS << (char)C; } void EmitInstruction(uint64_t Val, unsigned Size, raw_ostream &OS) const { // Output the instruction encoding in little endian byte order. // Little-endian byte ordering: // mips32r2: 4 | 3 | 2 | 1 // microMIPS: 2 | 1 | 4 | 3 if (IsLittleEndian && Size == 4 && IsMicroMips) { EmitInstruction(Val>>16, 2, OS); EmitInstruction(Val, 2, OS); } else { for (unsigned i = 0; i < Size; ++i) { unsigned Shift = IsLittleEndian ? i * 8 : (Size - 1 - i) * 8; EmitByte((Val >> Shift) & 0xff, OS); } } } void EncodeInstruction(const MCInst &MI, raw_ostream &OS, SmallVectorImpl &Fixups) const; // getBinaryCodeForInstr - TableGen'erated function for getting the // binary encoding for an instruction. uint64_t getBinaryCodeForInstr(const MCInst &MI, SmallVectorImpl &Fixups) const; // getBranchJumpOpValue - Return binary encoding of the jump // target operand. If the machine operand requires relocation, // record the relocation and return zero. unsigned getJumpTargetOpValue(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; // getBranchJumpOpValueMM - Return binary encoding of the microMIPS jump // target operand. If the machine operand requires relocation, // record the relocation and return zero. unsigned getJumpTargetOpValueMM(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; // getBranchTargetOpValue - Return binary encoding of the branch // target operand. If the machine operand requires relocation, // record the relocation and return zero. unsigned getBranchTargetOpValue(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; // getBranchTargetOpValue - Return binary encoding of the microMIPS branch // target operand. If the machine operand requires relocation, // record the relocation and return zero. unsigned getBranchTargetOpValueMM(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; // getMachineOpValue - Return binary encoding of operand. If the machin // operand requires relocation, record the relocation and return zero. unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO, SmallVectorImpl &Fixups) const; unsigned getMSAMemEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; unsigned getMemEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; unsigned getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; unsigned getSizeExtEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; unsigned getSizeInsEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; // getLSAImmEncoding - Return binary encoding of LSA immediate. unsigned getLSAImmEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const; unsigned getExprOpValue(const MCExpr *Expr,SmallVectorImpl &Fixups) const; }; // class MipsMCCodeEmitter } // namespace MCCodeEmitter *llvm::createMipsMCCodeEmitterEB(const MCInstrInfo &MCII, const MCRegisterInfo &MRI, const MCSubtargetInfo &STI, MCContext &Ctx) { return new MipsMCCodeEmitter(MCII, Ctx, STI, false); } MCCodeEmitter *llvm::createMipsMCCodeEmitterEL(const MCInstrInfo &MCII, const MCRegisterInfo &MRI, const MCSubtargetInfo &STI, MCContext &Ctx) { return new MipsMCCodeEmitter(MCII, Ctx, STI, true); } // If the D instruction has a shift amount that is greater // than 31 (checked in calling routine), lower it to a D32 instruction static void LowerLargeShift(MCInst& Inst) { assert(Inst.getNumOperands() == 3 && "Invalid no. of operands for shift!"); assert(Inst.getOperand(2).isImm()); int64_t Shift = Inst.getOperand(2).getImm(); if (Shift <= 31) return; // Do nothing Shift -= 32; // saminus32 Inst.getOperand(2).setImm(Shift); switch (Inst.getOpcode()) { default: // Calling function is not synchronized llvm_unreachable("Unexpected shift instruction"); case Mips::DSLL: Inst.setOpcode(Mips::DSLL32); return; case Mips::DSRL: Inst.setOpcode(Mips::DSRL32); return; case Mips::DSRA: Inst.setOpcode(Mips::DSRA32); return; case Mips::DROTR: Inst.setOpcode(Mips::DROTR32); return; } } // Pick a DEXT or DINS instruction variant based on the pos and size operands static void LowerDextDins(MCInst& InstIn) { int Opcode = InstIn.getOpcode(); if (Opcode == Mips::DEXT) assert(InstIn.getNumOperands() == 4 && "Invalid no. of machine operands for DEXT!"); else // Only DEXT and DINS are possible assert(InstIn.getNumOperands() == 5 && "Invalid no. of machine operands for DINS!"); assert(InstIn.getOperand(2).isImm()); int64_t pos = InstIn.getOperand(2).getImm(); assert(InstIn.getOperand(3).isImm()); int64_t size = InstIn.getOperand(3).getImm(); if (size <= 32) { if (pos < 32) // DEXT/DINS, do nothing return; // DEXTU/DINSU InstIn.getOperand(2).setImm(pos - 32); InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTU : Mips::DINSU); return; } // DEXTM/DINSM assert(pos < 32 && "DEXT/DINS cannot have both size and pos > 32"); InstIn.getOperand(3).setImm(size - 32); InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTM : Mips::DINSM); return; } /// EncodeInstruction - Emit the instruction. /// Size the instruction with Desc.getSize(). void MipsMCCodeEmitter:: EncodeInstruction(const MCInst &MI, raw_ostream &OS, SmallVectorImpl &Fixups) const { // Non-pseudo instructions that get changed for direct object // only based on operand values. // If this list of instructions get much longer we will move // the check to a function call. Until then, this is more efficient. MCInst TmpInst = MI; switch (MI.getOpcode()) { // If shift amount is >= 32 it the inst needs to be lowered further case Mips::DSLL: case Mips::DSRL: case Mips::DSRA: case Mips::DROTR: LowerLargeShift(TmpInst); break; // Double extract instruction is chosen by pos and size operands case Mips::DEXT: case Mips::DINS: LowerDextDins(TmpInst); } unsigned long N = Fixups.size(); uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups); // Check for unimplemented opcodes. // Unfortunately in MIPS both NOP and SLL will come in with Binary == 0 // so we have to special check for them. unsigned Opcode = TmpInst.getOpcode(); if ((Opcode != Mips::NOP) && (Opcode != Mips::SLL) && !Binary) llvm_unreachable("unimplemented opcode in EncodeInstruction()"); if (STI.getFeatureBits() & Mips::FeatureMicroMips) { int NewOpcode = Mips::Std2MicroMips (Opcode, Mips::Arch_micromips); if (NewOpcode != -1) { if (Fixups.size() > N) Fixups.pop_back(); Opcode = NewOpcode; TmpInst.setOpcode (NewOpcode); Binary = getBinaryCodeForInstr(TmpInst, Fixups); } } const MCInstrDesc &Desc = MCII.get(TmpInst.getOpcode()); // Get byte count of instruction unsigned Size = Desc.getSize(); if (!Size) llvm_unreachable("Desc.getSize() returns 0"); EmitInstruction(Binary, Size, OS); } /// getBranchTargetOpValue - Return binary encoding of the branch /// target operand. If the machine operand requires relocation, /// record the relocation and return zero. unsigned MipsMCCodeEmitter:: getBranchTargetOpValue(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { const MCOperand &MO = MI.getOperand(OpNo); // If the destination is an immediate, divide by 4. if (MO.isImm()) return MO.getImm() >> 2; assert(MO.isExpr() && "getBranchTargetOpValue expects only expressions or immediates"); const MCExpr *Expr = MO.getExpr(); Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(Mips::fixup_Mips_PC16))); return 0; } /// getBranchTargetOpValue - Return binary encoding of the microMIPS branch /// target operand. If the machine operand requires relocation, /// record the relocation and return zero. unsigned MipsMCCodeEmitter:: getBranchTargetOpValueMM(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { const MCOperand &MO = MI.getOperand(OpNo); // If the destination is an immediate, divide by 2. if (MO.isImm()) return MO.getImm() >> 1; assert(MO.isExpr() && "getBranchTargetOpValueMM expects only expressions or immediates"); const MCExpr *Expr = MO.getExpr(); Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(Mips:: fixup_MICROMIPS_PC16_S1))); return 0; } /// getJumpTargetOpValue - Return binary encoding of the jump /// target operand. If the machine operand requires relocation, /// record the relocation and return zero. unsigned MipsMCCodeEmitter:: getJumpTargetOpValue(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { const MCOperand &MO = MI.getOperand(OpNo); // If the destination is an immediate, divide by 4. if (MO.isImm()) return MO.getImm()>>2; assert(MO.isExpr() && "getJumpTargetOpValue expects only expressions or an immediate"); const MCExpr *Expr = MO.getExpr(); Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(Mips::fixup_Mips_26))); return 0; } unsigned MipsMCCodeEmitter:: getJumpTargetOpValueMM(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { const MCOperand &MO = MI.getOperand(OpNo); // If the destination is an immediate, divide by 2. if (MO.isImm()) return MO.getImm() >> 1; assert(MO.isExpr() && "getJumpTargetOpValueMM expects only expressions or an immediate"); const MCExpr *Expr = MO.getExpr(); Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(Mips::fixup_MICROMIPS_26_S1))); return 0; } unsigned MipsMCCodeEmitter:: getExprOpValue(const MCExpr *Expr,SmallVectorImpl &Fixups) const { int64_t Res; if (Expr->EvaluateAsAbsolute(Res)) return Res; MCExpr::ExprKind Kind = Expr->getKind(); if (Kind == MCExpr::Constant) { return cast(Expr)->getValue(); } if (Kind == MCExpr::Binary) { unsigned Res = getExprOpValue(cast(Expr)->getLHS(), Fixups); Res += getExprOpValue(cast(Expr)->getRHS(), Fixups); return Res; } if (Kind == MCExpr::SymbolRef) { Mips::Fixups FixupKind = Mips::Fixups(0); switch(cast(Expr)->getKind()) { default: llvm_unreachable("Unknown fixup kind!"); break; case MCSymbolRefExpr::VK_Mips_GPOFF_HI : FixupKind = Mips::fixup_Mips_GPOFF_HI; break; case MCSymbolRefExpr::VK_Mips_GPOFF_LO : FixupKind = Mips::fixup_Mips_GPOFF_LO; break; case MCSymbolRefExpr::VK_Mips_GOT_PAGE : FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT_PAGE : Mips::fixup_Mips_GOT_PAGE; break; case MCSymbolRefExpr::VK_Mips_GOT_OFST : FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT_OFST : Mips::fixup_Mips_GOT_OFST; break; case MCSymbolRefExpr::VK_Mips_GOT_DISP : FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT_DISP : Mips::fixup_Mips_GOT_DISP; break; case MCSymbolRefExpr::VK_Mips_GPREL: FixupKind = Mips::fixup_Mips_GPREL16; break; case MCSymbolRefExpr::VK_Mips_GOT_CALL: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_CALL16 : Mips::fixup_Mips_CALL16; break; case MCSymbolRefExpr::VK_Mips_GOT16: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT16 : Mips::fixup_Mips_GOT_Global; break; case MCSymbolRefExpr::VK_Mips_GOT: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_GOT16 : Mips::fixup_Mips_GOT_Local; break; case MCSymbolRefExpr::VK_Mips_ABS_HI: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_HI16 : Mips::fixup_Mips_HI16; break; case MCSymbolRefExpr::VK_Mips_ABS_LO: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_LO16 : Mips::fixup_Mips_LO16; break; case MCSymbolRefExpr::VK_Mips_TLSGD: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_GD : Mips::fixup_Mips_TLSGD; break; case MCSymbolRefExpr::VK_Mips_TLSLDM: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_LDM : Mips::fixup_Mips_TLSLDM; break; case MCSymbolRefExpr::VK_Mips_DTPREL_HI: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_DTPREL_HI16 : Mips::fixup_Mips_DTPREL_HI; break; case MCSymbolRefExpr::VK_Mips_DTPREL_LO: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_DTPREL_LO16 : Mips::fixup_Mips_DTPREL_LO; break; case MCSymbolRefExpr::VK_Mips_GOTTPREL: FixupKind = Mips::fixup_Mips_GOTTPREL; break; case MCSymbolRefExpr::VK_Mips_TPREL_HI: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_TPREL_HI16 : Mips::fixup_Mips_TPREL_HI; break; case MCSymbolRefExpr::VK_Mips_TPREL_LO: FixupKind = IsMicroMips ? Mips::fixup_MICROMIPS_TLS_TPREL_LO16 : Mips::fixup_Mips_TPREL_LO; break; case MCSymbolRefExpr::VK_Mips_HIGHER: FixupKind = Mips::fixup_Mips_HIGHER; break; case MCSymbolRefExpr::VK_Mips_HIGHEST: FixupKind = Mips::fixup_Mips_HIGHEST; break; case MCSymbolRefExpr::VK_Mips_GOT_HI16: FixupKind = Mips::fixup_Mips_GOT_HI16; break; case MCSymbolRefExpr::VK_Mips_GOT_LO16: FixupKind = Mips::fixup_Mips_GOT_LO16; break; case MCSymbolRefExpr::VK_Mips_CALL_HI16: FixupKind = Mips::fixup_Mips_CALL_HI16; break; case MCSymbolRefExpr::VK_Mips_CALL_LO16: FixupKind = Mips::fixup_Mips_CALL_LO16; break; } // switch Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(FixupKind))); return 0; } return 0; } /// getMachineOpValue - Return binary encoding of operand. If the machine /// operand requires relocation, record the relocation and return zero. unsigned MipsMCCodeEmitter:: getMachineOpValue(const MCInst &MI, const MCOperand &MO, SmallVectorImpl &Fixups) const { if (MO.isReg()) { unsigned Reg = MO.getReg(); unsigned RegNo = Ctx.getRegisterInfo()->getEncodingValue(Reg); return RegNo; } else if (MO.isImm()) { return static_cast(MO.getImm()); } else if (MO.isFPImm()) { return static_cast(APFloat(MO.getFPImm()) .bitcastToAPInt().getHiBits(32).getLimitedValue()); } // MO must be an Expr. assert(MO.isExpr()); return getExprOpValue(MO.getExpr(),Fixups); } /// getMSAMemEncoding - Return binary encoding of memory operand for LD/ST /// instructions. unsigned MipsMCCodeEmitter::getMSAMemEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { // Base register is encoded in bits 20-16, offset is encoded in bits 15-0. assert(MI.getOperand(OpNo).isReg()); unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups) << 16; unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups); // The immediate field of an LD/ST instruction is scaled which means it must // be divided (when encoding) by the size (in bytes) of the instructions' // data format. // .b - 1 byte // .h - 2 bytes // .w - 4 bytes // .d - 8 bytes switch(MI.getOpcode()) { default: assert (0 && "Unexpected instruction"); break; case Mips::LD_B: case Mips::ST_B: // We don't need to scale the offset in this case break; case Mips::LD_H: case Mips::ST_H: OffBits >>= 1; break; case Mips::LD_W: case Mips::ST_W: OffBits >>= 2; break; case Mips::LD_D: case Mips::ST_D: OffBits >>= 3; break; } return (OffBits & 0xFFFF) | RegBits; } /// getMemEncoding - Return binary encoding of memory related operand. /// If the offset operand requires relocation, record the relocation. unsigned MipsMCCodeEmitter::getMemEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { // Base register is encoded in bits 20-16, offset is encoded in bits 15-0. assert(MI.getOperand(OpNo).isReg()); unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups) << 16; unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups); return (OffBits & 0xFFFF) | RegBits; } unsigned MipsMCCodeEmitter:: getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { // Base register is encoded in bits 20-16, offset is encoded in bits 11-0. assert(MI.getOperand(OpNo).isReg()); unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups) << 16; unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups); return (OffBits & 0x0FFF) | RegBits; } unsigned MipsMCCodeEmitter::getSizeExtEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { assert(MI.getOperand(OpNo).isImm()); unsigned SizeEncoding = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups); return SizeEncoding - 1; } // FIXME: should be called getMSBEncoding // unsigned MipsMCCodeEmitter::getSizeInsEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { assert(MI.getOperand(OpNo-1).isImm()); assert(MI.getOperand(OpNo).isImm()); unsigned Position = getMachineOpValue(MI, MI.getOperand(OpNo-1), Fixups); unsigned Size = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups); return Position + Size - 1; } unsigned MipsMCCodeEmitter::getLSAImmEncoding(const MCInst &MI, unsigned OpNo, SmallVectorImpl &Fixups) const { assert(MI.getOperand(OpNo).isImm()); // The immediate is encoded as 'immediate - 1'. return getMachineOpValue(MI, MI.getOperand(OpNo), Fixups) - 1; } #include "MipsGenMCCodeEmitter.inc"