| //===-- X86/Printer.cpp - Convert X86 code to human readable rep. ---------===// |
| // |
| // This file contains a printer that converts from our internal representation |
| // of LLVM code to a nice human readable form that is suitable for debuggging. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "X86.h" |
| #include "X86InstrInfo.h" |
| #include "llvm/Pass.h" |
| #include "llvm/Function.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineInstr.h" |
| #include "Support/Statistic.h" |
| |
| namespace { |
| struct Printer : public FunctionPass { |
| TargetMachine &TM; |
| std::ostream &O; |
| |
| Printer(TargetMachine &tm, std::ostream &o) : TM(tm), O(o) {} |
| |
| bool runOnFunction(Function &F); |
| }; |
| } |
| |
| /// createX86CodePrinterPass - Print out the specified machine code function to |
| /// the specified stream. This function should work regardless of whether or |
| /// not the function is in SSA form or not. |
| /// |
| Pass *createX86CodePrinterPass(TargetMachine &TM, std::ostream &O) { |
| return new Printer(TM, O); |
| } |
| |
| |
| /// runOnFunction - This uses the X86InstructionInfo::print method |
| /// to print assembly for each instruction. |
| bool Printer::runOnFunction (Function & F) |
| { |
| static unsigned bbnumber = 0; |
| MachineFunction & MF = MachineFunction::get (&F); |
| const MachineInstrInfo & MII = TM.getInstrInfo (); |
| |
| O << "; x86 printing only sorta implemented so far!\n"; |
| |
| // Print out labels for the function. |
| O << "\t.globl\t" << F.getName () << "\n"; |
| O << "\t.type\t" << F.getName () << ", @function\n"; |
| O << F.getName () << ":\n"; |
| |
| // Print out code for the function. |
| for (MachineFunction::const_iterator bb_i = MF.begin (), bb_e = MF.end (); |
| bb_i != bb_e; ++bb_i) |
| { |
| // Print a label for the basic block. |
| O << ".BB" << bbnumber++ << ":\n"; |
| for (MachineBasicBlock::const_iterator i_i = bb_i->begin (), i_e = |
| bb_i->end (); i_i != i_e; ++i_i) |
| { |
| // Print the assembly for the instruction. |
| O << "\t"; |
| MII.print(*i_i, O, TM); |
| } |
| } |
| |
| // We didn't modify anything. |
| return false; |
| } |
| |
| static void printOp(std::ostream &O, const MachineOperand &MO, |
| const MRegisterInfo &RI) { |
| switch (MO.getType()) { |
| case MachineOperand::MO_VirtualRegister: |
| case MachineOperand::MO_MachineRegister: |
| if (MO.getReg() < MRegisterInfo::FirstVirtualRegister) |
| O << RI.get(MO.getReg()).Name; |
| else |
| O << "%reg" << MO.getReg(); |
| return; |
| |
| case MachineOperand::MO_SignExtendedImmed: |
| case MachineOperand::MO_UnextendedImmed: |
| O << (int)MO.getImmedValue(); |
| return; |
| default: |
| O << "<unknown op ty>"; return; |
| } |
| } |
| |
| static inline void toHexDigit(std::ostream &O, unsigned char V) { |
| if (V >= 10) |
| O << (char)('A'+V-10); |
| else |
| O << (char)('0'+V); |
| } |
| |
| static std::ostream &toHex(std::ostream &O, unsigned char V) { |
| toHexDigit(O, V >> 4); |
| toHexDigit(O, V & 0xF); |
| return O; |
| } |
| |
| static std::ostream &emitConstant(std::ostream &O, unsigned Val, unsigned Size){ |
| // Output the constant in little endian byte order... |
| for (unsigned i = 0; i != Size; ++i) { |
| toHex(O, Val) << " "; |
| Val >>= 8; |
| } |
| return O; |
| } |
| |
| |
| static bool isReg(const MachineOperand &MO) { |
| return MO.getType() == MachineOperand::MO_VirtualRegister || |
| MO.getType() == MachineOperand::MO_MachineRegister; |
| } |
| |
| static bool isImmediate(const MachineOperand &MO) { |
| return MO.getType() == MachineOperand::MO_SignExtendedImmed || |
| MO.getType() == MachineOperand::MO_UnextendedImmed; |
| } |
| |
| |
| // getX86RegNum - This function maps LLVM register identifiers to their X86 |
| // specific numbering, which is used in various places encoding instructions. |
| // |
| static unsigned getX86RegNum(unsigned RegNo) { |
| switch(RegNo) { |
| case X86::EAX: case X86::AX: case X86::AL: return 0; |
| case X86::ECX: case X86::CX: case X86::CL: return 1; |
| case X86::EDX: case X86::DX: case X86::DL: return 2; |
| case X86::EBX: case X86::BX: case X86::BL: return 3; |
| case X86::ESP: case X86::SP: case X86::AH: return 4; |
| case X86::EBP: case X86::BP: case X86::CH: return 5; |
| case X86::ESI: case X86::SI: case X86::DH: return 6; |
| case X86::EDI: case X86::DI: case X86::BH: return 7; |
| default: |
| assert(RegNo >= MRegisterInfo::FirstVirtualRegister && |
| "Unknown physical register!"); |
| DEBUG(std::cerr << "Register allocator hasn't allocated " << RegNo |
| << " correctly yet!\n"); |
| return 0; |
| } |
| } |
| |
| inline static unsigned char ModRMByte(unsigned Mod, unsigned RegOpcode, |
| unsigned RM) { |
| assert(Mod < 4 && RegOpcode < 8 && RM < 8 && "ModRM Fields out of range!"); |
| return RM | (RegOpcode << 3) | (Mod << 6); |
| } |
| |
| static unsigned char regModRMByte(unsigned ModRMReg, unsigned RegOpcodeField) { |
| return ModRMByte(3, RegOpcodeField, getX86RegNum(ModRMReg)); |
| } |
| |
| |
| // print - Print out an x86 instruction in intel syntax |
| void X86InstrInfo::print(const MachineInstr *MI, std::ostream &O, |
| const TargetMachine &TM) const { |
| unsigned Opcode = MI->getOpcode(); |
| const MachineInstrDescriptor &Desc = get(Opcode); |
| |
| // Print instruction prefixes if neccesary |
| |
| if (Desc.TSFlags & X86II::OpSize) O << "66 "; // Operand size... |
| if (Desc.TSFlags & X86II::TB) O << "0F "; // Two-byte opcode prefix |
| |
| switch (Desc.TSFlags & X86II::FormMask) { |
| case X86II::OtherFrm: |
| O << "\t\t\t"; |
| O << "-"; MI->print(O, TM); |
| break; |
| case X86II::RawFrm: |
| toHex(O, getBaseOpcodeFor(Opcode)); |
| O << "\n\t\t\t\t"; |
| O << getName(MI->getOpCode()) << " "; |
| |
| for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { |
| if (i) O << ", "; |
| printOp(O, MI->getOperand(i), RI); |
| } |
| O << "\n"; |
| return; |
| |
| |
| case X86II::AddRegFrm: { |
| // There are currently two forms of acceptable AddRegFrm instructions. |
| // Either the instruction JUST takes a single register (like inc, dec, etc), |
| // or it takes a register and an immediate of the same size as the register |
| // (move immediate f.e.). |
| // |
| assert(isReg(MI->getOperand(0)) && |
| (MI->getNumOperands() == 1 || |
| (MI->getNumOperands() == 2 && isImmediate(MI->getOperand(1)))) && |
| "Illegal form for AddRegFrm instruction!"); |
| |
| unsigned Reg = MI->getOperand(0).getReg(); |
| toHex(O, getBaseOpcodeFor(Opcode) + getX86RegNum(Reg)) << " "; |
| |
| if (MI->getNumOperands() == 2) { |
| unsigned Size = 4; |
| emitConstant(O, MI->getOperand(1).getImmedValue(), Size); |
| } |
| |
| O << "\n\t\t\t\t"; |
| O << getName(MI->getOpCode()) << " "; |
| printOp(O, MI->getOperand(0), RI); |
| if (MI->getNumOperands() == 2) { |
| O << ", "; |
| printOp(O, MI->getOperand(MI->getNumOperands()-1), RI); |
| } |
| O << "\n"; |
| return; |
| } |
| case X86II::MRMDestReg: { |
| // There are two acceptable forms of MRMDestReg instructions, those with 3 |
| // and 2 operands: |
| // |
| // 3 Operands: in this form, the first two registers (the destination, and |
| // the first operand) should be the same, post register allocation. The 3rd |
| // operand is an additional input. This should be for things like add |
| // instructions. |
| // |
| // 2 Operands: this is for things like mov that do not read a second input |
| // |
| assert(isReg(MI->getOperand(0)) && |
| (MI->getNumOperands() == 2 || |
| (MI->getNumOperands() == 3 && isReg(MI->getOperand(1)))) && |
| isReg(MI->getOperand(MI->getNumOperands()-1)) |
| && "Bad format for MRMDestReg!"); |
| if (MI->getNumOperands() == 3 && |
| MI->getOperand(0).getReg() != MI->getOperand(1).getReg()) |
| O << "**"; |
| |
| toHex(O, getBaseOpcodeFor(Opcode)) << " "; |
| unsigned ModRMReg = MI->getOperand(0).getReg(); |
| unsigned ExtraReg = MI->getOperand(MI->getNumOperands()-1).getReg(); |
| toHex(O, regModRMByte(ModRMReg, getX86RegNum(ExtraReg))); |
| |
| O << "\n\t\t\t\t"; |
| O << getName(MI->getOpCode()) << " "; |
| printOp(O, MI->getOperand(0), RI); |
| O << ", "; |
| printOp(O, MI->getOperand(MI->getNumOperands()-1), RI); |
| O << "\n"; |
| return; |
| } |
| case X86II::MRMSrcReg: { |
| // There is a two forms that are acceptable for MRMSrcReg instructions, |
| // those with 3 and 2 operands: |
| // |
| // 3 Operands: in this form, the last register (the second input) is the |
| // ModR/M input. The first two operands should be the same, post register |
| // allocation. This is for things like: add r32, r/m32 |
| // |
| // 2 Operands: this is for things like mov that do not read a second input |
| // |
| assert(isReg(MI->getOperand(0)) && |
| isReg(MI->getOperand(1)) && |
| (MI->getNumOperands() == 2 || |
| (MI->getNumOperands() == 3 && isReg(MI->getOperand(2)))) |
| && "Bad format for MRMDestReg!"); |
| if (MI->getNumOperands() == 3 && |
| MI->getOperand(0).getReg() != MI->getOperand(1).getReg()) |
| O << "**"; |
| |
| toHex(O, getBaseOpcodeFor(Opcode)) << " "; |
| unsigned ModRMReg = MI->getOperand(MI->getNumOperands()-1).getReg(); |
| unsigned ExtraReg = MI->getOperand(0).getReg(); |
| toHex(O, regModRMByte(ModRMReg, getX86RegNum(ExtraReg))); |
| |
| O << "\n\t\t\t\t"; |
| O << getName(MI->getOpCode()) << " "; |
| printOp(O, MI->getOperand(0), RI); |
| O << ", "; |
| printOp(O, MI->getOperand(MI->getNumOperands()-1), RI); |
| O << "\n"; |
| return; |
| } |
| case X86II::MRMDestMem: |
| case X86II::MRMSrcMem: |
| default: |
| O << "\t\t\t-"; MI->print(O, TM); break; |
| } |
| } |