llvm-6502/lib/Target/XCore/XCoreMCInstLower.cpp

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//===-- XCoreMCInstLower.cpp - Convert XCore MachineInstr to MCInst -------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file contains code to lower XCore MachineInstrs to their
/// corresponding MCInst records.
///
//===----------------------------------------------------------------------===//
#include "XCoreMCInstLower.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/IR/Mangler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
using namespace llvm;
XCoreMCInstLower::XCoreMCInstLower(class AsmPrinter &asmprinter)
: Printer(asmprinter) {}
void XCoreMCInstLower::Initialize(Mangler *M, MCContext *C) {
Mang = M;
Ctx = C;
}
MCOperand XCoreMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
MachineOperandType MOTy,
unsigned Offset) const {
MCSymbolRefExpr::VariantKind Kind = MCSymbolRefExpr::VK_None;
const MCSymbol *Symbol;
switch (MOTy) {
case MachineOperand::MO_MachineBasicBlock:
Symbol = MO.getMBB()->getSymbol();
break;
case MachineOperand::MO_GlobalAddress:
Symbol = Printer.getSymbol(MO.getGlobal());
Offset += MO.getOffset();
break;
case MachineOperand::MO_BlockAddress:
Symbol = Printer.GetBlockAddressSymbol(MO.getBlockAddress());
Offset += MO.getOffset();
break;
case MachineOperand::MO_ExternalSymbol:
Symbol = Printer.GetExternalSymbolSymbol(MO.getSymbolName());
Offset += MO.getOffset();
break;
case MachineOperand::MO_JumpTableIndex:
Symbol = Printer.GetJTISymbol(MO.getIndex());
break;
case MachineOperand::MO_ConstantPoolIndex:
Symbol = Printer.GetCPISymbol(MO.getIndex());
Offset += MO.getOffset();
break;
default:
llvm_unreachable("<unknown operand type>");
}
const MCSymbolRefExpr *MCSym = MCSymbolRefExpr::Create(Symbol, Kind, *Ctx);
if (!Offset)
return MCOperand::CreateExpr(MCSym);
// Assume offset is never negative.
assert(Offset > 0);
const MCConstantExpr *OffsetExpr = MCConstantExpr::Create(Offset, *Ctx);
const MCBinaryExpr *Add = MCBinaryExpr::CreateAdd(MCSym, OffsetExpr, *Ctx);
return MCOperand::CreateExpr(Add);
}
MCOperand XCoreMCInstLower::LowerOperand(const MachineOperand &MO,
unsigned offset) const {
MachineOperandType MOTy = MO.getType();
switch (MOTy) {
default: llvm_unreachable("unknown operand type");
case MachineOperand::MO_Register:
// Ignore all implicit register operands.
if (MO.isImplicit()) break;
return MCOperand::CreateReg(MO.getReg());
case MachineOperand::MO_Immediate:
return MCOperand::CreateImm(MO.getImm() + offset);
case MachineOperand::MO_MachineBasicBlock:
case MachineOperand::MO_GlobalAddress:
case MachineOperand::MO_ExternalSymbol:
case MachineOperand::MO_JumpTableIndex:
case MachineOperand::MO_ConstantPoolIndex:
case MachineOperand::MO_BlockAddress:
return LowerSymbolOperand(MO, MOTy, offset);
case MachineOperand::MO_RegisterMask:
break;
}
return MCOperand();
}
void XCoreMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
OutMI.setOpcode(MI->getOpcode());
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
MCOperand MCOp = LowerOperand(MO);
if (MCOp.isValid())
OutMI.addOperand(MCOp);
}
}