//===-- BlackfinAsmPrinter.cpp - Blackfin LLVM assembly writer ------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a printer that converts from our internal representation
// of machine-dependent LLVM code to GAS-format BLACKFIN assembly language.
//
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "asm-printer"
#include "Blackfin.h"
#include "BlackfinInstrInfo.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/DwarfWriter.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormattedStream.h"
using namespace llvm;

STATISTIC(EmittedInsts, "Number of machine instrs printed");

namespace {
  class BlackfinAsmPrinter : public AsmPrinter {
  public:
    BlackfinAsmPrinter(formatted_raw_ostream &O, TargetMachine &TM,
                       const MCAsmInfo *MAI, bool V)
      : AsmPrinter(O, TM, MAI, V) {}

    virtual const char *getPassName() const {
      return "Blackfin Assembly Printer";
    }

    void printOperand(const MachineInstr *MI, int opNum);
    void printMemoryOperand(const MachineInstr *MI, int opNum);
    void printInstruction(const MachineInstr *MI);  // autogenerated.
    static const char *getRegisterName(unsigned RegNo);

    void emitLinkage(const MCSymbol *GVSym, GlobalValue::LinkageTypes l);
    bool runOnMachineFunction(MachineFunction &F);
    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                         unsigned AsmVariant, const char *ExtraCode);
    bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
                               unsigned AsmVariant, const char *ExtraCode);
  };
} // end of anonymous namespace

#include "BlackfinGenAsmWriter.inc"

extern "C" void LLVMInitializeBlackfinAsmPrinter() {
  RegisterAsmPrinter<BlackfinAsmPrinter> X(TheBlackfinTarget);
}

void BlackfinAsmPrinter::emitLinkage(const MCSymbol *GVSym,
                                     GlobalValue::LinkageTypes L) {
  switch (L) {
  default: llvm_unreachable("Unknown linkage type!");
  case GlobalValue::InternalLinkage:  // Symbols default to internal.
  case GlobalValue::PrivateLinkage:
  case GlobalValue::LinkerPrivateLinkage:
    break;
  case GlobalValue::ExternalLinkage:
    O << MAI->getGlobalDirective() << *GVSym << "\n";
    break;
  case GlobalValue::LinkOnceAnyLinkage:
  case GlobalValue::LinkOnceODRLinkage:
  case GlobalValue::WeakAnyLinkage:
  case GlobalValue::WeakODRLinkage:
    O << MAI->getGlobalDirective() << *GVSym << "\n";
    O << MAI->getWeakDefDirective() << *GVSym << "\n";
    break;
  }
}

/// runOnMachineFunction - This uses the printInstruction()
/// method to print assembly for each instruction.
///
bool BlackfinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
  SetupMachineFunction(MF);
  EmitConstantPool(MF.getConstantPool());
  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);

  const Function *F = MF.getFunction();
  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
  EmitAlignment(2, F);
  emitLinkage(CurrentFnSym, F->getLinkage());
  printVisibility(CurrentFnSym, F->getVisibility());

  O << "\t.type\t" << *CurrentFnSym << ", STT_FUNC\n";
  O << *CurrentFnSym << ":\n";

  if (DW)
    DW->BeginFunction(&MF);

  // Print out code for the function.
  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
       I != E; ++I) {
    // Print a label for the basic block.
    EmitBasicBlockStart(I);

    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
         II != E; ++II) {
      // Print the assembly for the instruction.
      processDebugLoc(II, true);

      printInstruction(II);
      if (VerboseAsm)
        EmitComments(*II);
      O << '\n';
      
      processDebugLoc(II, false);
      ++EmittedInsts;
    }
  }

  O << "\t.size " << *CurrentFnSym << ", .-" << *CurrentFnSym << "\n";

  if (DW)
    DW->EndFunction(&MF);

  return false;
}

void BlackfinAsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
  const MachineOperand &MO = MI->getOperand (opNum);
  switch (MO.getType()) {
  case MachineOperand::MO_Register:
    assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
           "Virtual registers should be already mapped!");
    O << getRegisterName(MO.getReg());
    break;

  case MachineOperand::MO_Immediate:
    O << MO.getImm();
    break;
  case MachineOperand::MO_MachineBasicBlock:
    O << *GetMBBSymbol(MO.getMBB()->getNumber());
    return;
  case MachineOperand::MO_GlobalAddress:
    O << *GetGlobalValueSymbol(MO.getGlobal());
    printOffset(MO.getOffset());
    break;
  case MachineOperand::MO_ExternalSymbol:
    O << *GetExternalSymbolSymbol(MO.getSymbolName());
    break;
  case MachineOperand::MO_ConstantPoolIndex:
    O << MAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
      << MO.getIndex();
    break;
  case MachineOperand::MO_JumpTableIndex:
    O << MAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
      << '_' << MO.getIndex();
    break;
  default:
    llvm_unreachable("<unknown operand type>");
    break;
  }
}

void BlackfinAsmPrinter::printMemoryOperand(const MachineInstr *MI, int opNum) {
  printOperand(MI, opNum);

  if (MI->getOperand(opNum+1).isImm() && MI->getOperand(opNum+1).getImm() == 0)
    return;

  O << " + ";
  printOperand(MI, opNum+1);
}

/// PrintAsmOperand - Print out an operand for an inline asm expression.
///
bool BlackfinAsmPrinter::PrintAsmOperand(const MachineInstr *MI,
                                         unsigned OpNo,
                                         unsigned AsmVariant,
                                         const char *ExtraCode) {
  if (ExtraCode && ExtraCode[0]) {
    if (ExtraCode[1] != 0) return true; // Unknown modifier.

    switch (ExtraCode[0]) {
    default: return true;  // Unknown modifier.
    case 'r':
      break;
    }
  }

  printOperand(MI, OpNo);

  return false;
}

bool BlackfinAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
                                               unsigned OpNo,
                                               unsigned AsmVariant,
                                               const char *ExtraCode) {
  if (ExtraCode && ExtraCode[0])
    return true;  // Unknown modifier

  O << '[';
  printOperand(MI, OpNo);
  O << ']';

  return false;
}