llvm-project/llvm/lib/Target/Mips/MipsMCInstLower.cpp

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//===- MipsMCInstLower.cpp - Convert Mips MachineInstr to 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 Mips MachineInstrs to their corresponding
// MCInst records.
//
//===----------------------------------------------------------------------===//
#include "MipsMCInstLower.h"
#include "MCTargetDesc/MipsBaseInfo.h"
#include "MCTargetDesc/MipsMCExpr.h"
#include "MipsAsmPrinter.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
using namespace llvm;
MipsMCInstLower::MipsMCInstLower(MipsAsmPrinter &asmprinter)
: AsmPrinter(asmprinter) {}
void MipsMCInstLower::Initialize(MCContext *C) {
Ctx = C;
}
MCOperand MipsMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
MachineOperandType MOTy,
unsigned Offset) const {
MCSymbolRefExpr::VariantKind Kind = MCSymbolRefExpr::VK_None;
MipsMCExpr::MipsExprKind TargetKind = MipsMCExpr::MEK_None;
bool IsGpOff = false;
const MCSymbol *Symbol;
switch(MO.getTargetFlags()) {
default:
llvm_unreachable("Invalid target flag!");
case MipsII::MO_NO_FLAG:
break;
case MipsII::MO_GPREL:
TargetKind = MipsMCExpr::MEK_GPREL;
break;
case MipsII::MO_GOT_CALL:
TargetKind = MipsMCExpr::MEK_GOT_CALL;
break;
case MipsII::MO_GOT:
TargetKind = MipsMCExpr::MEK_GOT;
break;
case MipsII::MO_ABS_HI:
TargetKind = MipsMCExpr::MEK_HI;
break;
case MipsII::MO_ABS_LO:
TargetKind = MipsMCExpr::MEK_LO;
break;
case MipsII::MO_TLSGD:
TargetKind = MipsMCExpr::MEK_TLSGD;
break;
case MipsII::MO_TLSLDM:
TargetKind = MipsMCExpr::MEK_TLSLDM;
break;
case MipsII::MO_DTPREL_HI:
TargetKind = MipsMCExpr::MEK_DTPREL_HI;
break;
case MipsII::MO_DTPREL_LO:
TargetKind = MipsMCExpr::MEK_DTPREL_LO;
break;
case MipsII::MO_GOTTPREL:
TargetKind = MipsMCExpr::MEK_GOTTPREL;
break;
case MipsII::MO_TPREL_HI:
TargetKind = MipsMCExpr::MEK_TPREL_HI;
break;
case MipsII::MO_TPREL_LO:
TargetKind = MipsMCExpr::MEK_TPREL_LO;
break;
case MipsII::MO_GPOFF_HI:
TargetKind = MipsMCExpr::MEK_HI;
IsGpOff = true;
break;
case MipsII::MO_GPOFF_LO:
TargetKind = MipsMCExpr::MEK_LO;
IsGpOff = true;
break;
case MipsII::MO_GOT_DISP:
TargetKind = MipsMCExpr::MEK_GOT_DISP;
break;
case MipsII::MO_GOT_HI16:
TargetKind = MipsMCExpr::MEK_GOT_HI16;
break;
case MipsII::MO_GOT_LO16:
TargetKind = MipsMCExpr::MEK_GOT_LO16;
break;
case MipsII::MO_GOT_PAGE:
TargetKind = MipsMCExpr::MEK_GOT_PAGE;
break;
case MipsII::MO_GOT_OFST:
TargetKind = MipsMCExpr::MEK_GOT_OFST;
break;
case MipsII::MO_HIGHER:
TargetKind = MipsMCExpr::MEK_HIGHER;
break;
case MipsII::MO_HIGHEST:
TargetKind = MipsMCExpr::MEK_HIGHEST;
break;
case MipsII::MO_CALL_HI16:
TargetKind = MipsMCExpr::MEK_CALL_HI16;
break;
case MipsII::MO_CALL_LO16:
TargetKind = MipsMCExpr::MEK_CALL_LO16;
break;
}
switch (MOTy) {
case MachineOperand::MO_MachineBasicBlock:
Symbol = MO.getMBB()->getSymbol();
break;
case MachineOperand::MO_GlobalAddress:
Symbol = AsmPrinter.getSymbol(MO.getGlobal());
Offset += MO.getOffset();
break;
case MachineOperand::MO_BlockAddress:
Symbol = AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress());
Offset += MO.getOffset();
break;
case MachineOperand::MO_ExternalSymbol:
Symbol = AsmPrinter.GetExternalSymbolSymbol(MO.getSymbolName());
Offset += MO.getOffset();
break;
case MachineOperand::MO_MCSymbol:
Symbol = MO.getMCSymbol();
Offset += MO.getOffset();
break;
case MachineOperand::MO_JumpTableIndex:
Symbol = AsmPrinter.GetJTISymbol(MO.getIndex());
break;
case MachineOperand::MO_ConstantPoolIndex:
Symbol = AsmPrinter.GetCPISymbol(MO.getIndex());
Offset += MO.getOffset();
break;
default:
llvm_unreachable("<unknown operand type>");
}
const MCExpr *Expr = MCSymbolRefExpr::create(Symbol, Kind, *Ctx);
if (Offset) {
// Assume offset is never negative.
assert(Offset > 0);
Expr = MCBinaryExpr::createAdd(Expr, MCConstantExpr::create(Offset, *Ctx),
*Ctx);
}
if (IsGpOff)
Expr = MipsMCExpr::createGpOff(TargetKind, Expr, *Ctx);
else if (TargetKind != MipsMCExpr::MEK_None)
Expr = MipsMCExpr::create(TargetKind, Expr, *Ctx);
return MCOperand::createExpr(Expr);
}
MCOperand MipsMCInstLower::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_MCSymbol:
case MachineOperand::MO_JumpTableIndex:
case MachineOperand::MO_ConstantPoolIndex:
case MachineOperand::MO_BlockAddress:
return LowerSymbolOperand(MO, MOTy, offset);
case MachineOperand::MO_RegisterMask:
break;
}
return MCOperand();
}
MCOperand MipsMCInstLower::createSub(MachineBasicBlock *BB1,
MachineBasicBlock *BB2,
MipsMCExpr::MipsExprKind Kind) const {
const MCSymbolRefExpr *Sym1 = MCSymbolRefExpr::create(BB1->getSymbol(), *Ctx);
const MCSymbolRefExpr *Sym2 = MCSymbolRefExpr::create(BB2->getSymbol(), *Ctx);
const MCBinaryExpr *Sub = MCBinaryExpr::createSub(Sym1, Sym2, *Ctx);
return MCOperand::createExpr(MipsMCExpr::create(Kind, Sub, *Ctx));
}
void MipsMCInstLower::
lowerLongBranchLUi(const MachineInstr *MI, MCInst &OutMI) const {
OutMI.setOpcode(Mips::LUi);
// Lower register operand.
OutMI.addOperand(LowerOperand(MI->getOperand(0)));
// Create %hi($tgt-$baltgt).
OutMI.addOperand(createSub(MI->getOperand(1).getMBB(),
MI->getOperand(2).getMBB(),
MipsMCExpr::MEK_HI));
}
void MipsMCInstLower::lowerLongBranchADDiu(
const MachineInstr *MI, MCInst &OutMI, int Opcode,
MipsMCExpr::MipsExprKind Kind) const {
OutMI.setOpcode(Opcode);
// Lower two register operands.
for (unsigned I = 0, E = 2; I != E; ++I) {
const MachineOperand &MO = MI->getOperand(I);
OutMI.addOperand(LowerOperand(MO));
}
// Create %lo($tgt-$baltgt) or %hi($tgt-$baltgt).
OutMI.addOperand(createSub(MI->getOperand(2).getMBB(),
MI->getOperand(3).getMBB(), Kind));
}
bool MipsMCInstLower::lowerLongBranch(const MachineInstr *MI,
MCInst &OutMI) const {
switch (MI->getOpcode()) {
default:
return false;
case Mips::LONG_BRANCH_LUi:
lowerLongBranchLUi(MI, OutMI);
return true;
case Mips::LONG_BRANCH_ADDiu:
lowerLongBranchADDiu(MI, OutMI, Mips::ADDiu, MipsMCExpr::MEK_LO);
return true;
case Mips::LONG_BRANCH_DADDiu:
unsigned TargetFlags = MI->getOperand(2).getTargetFlags();
if (TargetFlags == MipsII::MO_ABS_HI)
lowerLongBranchADDiu(MI, OutMI, Mips::DADDiu, MipsMCExpr::MEK_HI);
else if (TargetFlags == MipsII::MO_ABS_LO)
lowerLongBranchADDiu(MI, OutMI, Mips::DADDiu, MipsMCExpr::MEK_LO);
else
report_fatal_error("Unexpected flags for LONG_BRANCH_DADDiu");
return true;
}
}
void MipsMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
if (lowerLongBranch(MI, OutMI))
return;
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);
}
}