llvm-6502/lib/Target/ARM/ARMMCInstLower.cpp

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//===-- ARMMCInstLower.cpp - Convert ARM MachineInstr to an MCInst --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains code to lower ARM MachineInstrs to their corresponding
// MCInst records.
//
//===----------------------------------------------------------------------===//
#include "ARM.h"
#include "ARMMCInstLower.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/Constants.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Target/Mangler.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/SmallString.h"
using namespace llvm;
MCSymbol *ARMMCInstLower::GetGlobalAddressSymbol(const GlobalValue *GV) const {
return Printer.Mang->getSymbol(GV);
}
const MCSymbolRefExpr *ARMMCInstLower::
GetSymbolRef(const MachineOperand &MO) const {
assert(MO.isGlobal() && "Isn't a global address reference?");
const MCSymbolRefExpr *SymRef;
const MCSymbol *Symbol = GetGlobalAddressSymbol(MO.getGlobal());
switch (MO.getTargetFlags()) {
default: assert(0 && "Unknown target flag on GV operand");
case 0:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None, Ctx);
break;
case ARMII::MO_LO16:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_LO16, Ctx);
break;
case ARMII::MO_HI16:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_HI16, Ctx);
break;
case ARMII::MO_PLT:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_PLT, Ctx);
break;
}
return SymRef;
}
const MCSymbolRefExpr *ARMMCInstLower::
GetExternalSymbolSymbol(const MachineOperand &MO) const {
const MCSymbolRefExpr *SymRef;
const MCSymbol *Symbol = Printer.GetExternalSymbolSymbol(MO.getSymbolName());
switch (MO.getTargetFlags()) {
default: assert(0 && "Unknown target flag on external symbol operand");
case 0:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None, Ctx);
break;
case ARMII::MO_LO16:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_LO16, Ctx);
break;
case ARMII::MO_HI16:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_HI16, Ctx);
break;
case ARMII::MO_PLT:
SymRef = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_ARM_PLT, Ctx);
break;
}
return SymRef;
}
MCSymbol *ARMMCInstLower::
GetJumpTableSymbol(const MachineOperand &MO) const {
SmallString<256> Name;
raw_svector_ostream(Name) << Printer.MAI->getPrivateGlobalPrefix() << "JTI"
<< Printer.getFunctionNumber() << '_' << MO.getIndex();
switch (MO.getTargetFlags()) {
default: assert(0 && "Unknown target flag on jump table operand");
case 0: break;
}
// Create a symbol for the name.
return Ctx.GetOrCreateSymbol(Name.str());
}
MCSymbol *ARMMCInstLower::
GetConstantPoolIndexSymbol(const MachineOperand &MO) const {
SmallString<256> Name;
raw_svector_ostream(Name) << Printer.MAI->getPrivateGlobalPrefix() << "CPI"
<< Printer.getFunctionNumber() << '_' << MO.getIndex();
switch (MO.getTargetFlags()) {
default: assert(0 && "Unknown target flag on CPI operand");
case 0: break;
}
// Create a symbol for the name.
return Ctx.GetOrCreateSymbol(Name.str());
}
MCOperand ARMMCInstLower::
LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const {
// FIXME: We would like an efficient form for this, so we don't have to do a
// lot of extra uniquing.
const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx);
switch (MO.getTargetFlags()) {
default: assert(0 && "Unknown target flag on Symbol operand");
case 0: break;
}
if (!MO.isJTI() && MO.getOffset())
Expr = MCBinaryExpr::CreateAdd(Expr,
MCConstantExpr::Create(MO.getOffset(), Ctx),
Ctx);
return MCOperand::CreateExpr(Expr);
}
MCOperand ARMMCInstLower::
LowerSymbolRefOperand(const MachineOperand &MO,
const MCSymbolRefExpr *Sym) const {
const MCExpr *Expr = Sym;
if (!MO.isJTI() && MO.getOffset())
Expr = MCBinaryExpr::CreateAdd(Expr,
MCConstantExpr::Create(MO.getOffset(), Ctx),
Ctx);
return MCOperand::CreateExpr(Expr);
}
void ARMMCInstLower::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;
switch (MO.getType()) {
default:
MI->dump();
assert(0 && "unknown operand type");
case MachineOperand::MO_Register:
// Ignore all non-CPSR implicit register operands.
if (MO.isImplicit() && MO.getReg() != ARM::CPSR) continue;
assert(!MO.getSubReg() && "Subregs should be eliminated!");
MCOp = MCOperand::CreateReg(MO.getReg());
break;
case MachineOperand::MO_Immediate:
MCOp = MCOperand::CreateImm(MO.getImm());
break;
case MachineOperand::MO_MachineBasicBlock:
MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
MO.getMBB()->getSymbol(), Ctx));
break;
case MachineOperand::MO_GlobalAddress:
MCOp = LowerSymbolRefOperand(MO, GetSymbolRef(MO));
break;
case MachineOperand::MO_ExternalSymbol:
MCOp = LowerSymbolRefOperand(MO, GetExternalSymbolSymbol(MO));
break;
case MachineOperand::MO_JumpTableIndex:
MCOp = LowerSymbolOperand(MO, GetJumpTableSymbol(MO));
break;
case MachineOperand::MO_ConstantPoolIndex:
MCOp = LowerSymbolOperand(MO, GetConstantPoolIndexSymbol(MO));
break;
case MachineOperand::MO_BlockAddress:
MCOp = LowerSymbolOperand(MO, Printer.GetBlockAddressSymbol(
MO.getBlockAddress()));
break;
case MachineOperand::MO_FPImmediate:
APFloat Val = MO.getFPImm()->getValueAPF();
bool ignored;
Val.convert(APFloat::IEEEdouble, APFloat::rmTowardZero, &ignored);
MCOp = MCOperand::CreateFPImm(Val.convertToDouble());
break;
}
OutMI.addOperand(MCOp);
}
}