llvm-6502/lib/Target/X86/Printer.cpp
2002-11-21 02:00:20 +00:00

287 lines
9.2 KiB
C++

//===-- 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;
}
}