llvm/lib/Target/ARM/Thumb1InstrInfo.cpp

254 lines
7.9 KiB
C++

//===- Thumb1InstrInfo.cpp - Thumb-1 Instruction Information --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the Thumb-1 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "ARMInstrInfo.h"
#include "ARM.h"
#include "ARMGenInstrInfo.inc"
#include "ARMMachineFunctionInfo.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/ADT/SmallVector.h"
#include "Thumb1InstrInfo.h"
using namespace llvm;
Thumb1InstrInfo::Thumb1InstrInfo(const ARMSubtarget &STI)
: ARMBaseInstrInfo(STI), RI(*this, STI) {
}
unsigned Thumb1InstrInfo::getUnindexedOpcode(unsigned Opc) const {
return 0;
}
unsigned Thumb1InstrInfo::getOpcode(ARMII::Op Op) const {
switch (Op) {
case ARMII::ADDri: return ARM::tADDi8;
case ARMII::ADDrs: return 0;
case ARMII::ADDrr: return ARM::tADDrr;
case ARMII::B: return ARM::tB;
case ARMII::Bcc: return ARM::tBcc;
case ARMII::BX_RET: return ARM::tBX_RET;
case ARMII::LDRri: return 0;
case ARMII::MOVr: return ARM::tMOVr;
case ARMII::STRri: return 0;
case ARMII::SUBri: return ARM::tSUBi8;
case ARMII::SUBrs: return 0;
case ARMII::SUBrr: return ARM::tSUBrr;
default:
break;
}
return 0;
}
bool
Thumb1InstrInfo::BlockHasNoFallThrough(const MachineBasicBlock &MBB) const {
if (MBB.empty()) return false;
switch (MBB.back().getOpcode()) {
case ARM::tBX_RET:
case ARM::tBX_RET_vararg:
case ARM::tPOP_RET:
case ARM::tB:
case ARM::tBR_JTr:
return true;
default:
break;
}
return false;
}
bool Thumb1InstrInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *DestRC,
const TargetRegisterClass *SrcRC) const {
DebugLoc DL = DebugLoc::getUnknownLoc();
if (I != MBB.end()) DL = I->getDebugLoc();
if (DestRC == ARM::GPRRegisterClass) {
if (SrcRC == ARM::GPRRegisterClass) {
BuildMI(MBB, I, DL, get(ARM::tMOVgpr2gpr), DestReg).addReg(SrcReg);
return true;
} else if (SrcRC == ARM::tGPRRegisterClass) {
BuildMI(MBB, I, DL, get(ARM::tMOVtgpr2gpr), DestReg).addReg(SrcReg);
return true;
}
} else if (DestRC == ARM::tGPRRegisterClass) {
if (SrcRC == ARM::GPRRegisterClass) {
BuildMI(MBB, I, DL, get(ARM::tMOVgpr2tgpr), DestReg).addReg(SrcReg);
return true;
} else if (SrcRC == ARM::tGPRRegisterClass) {
BuildMI(MBB, I, DL, get(ARM::tMOVr), DestReg).addReg(SrcReg);
return true;
}
}
return false;
}
bool Thumb1InstrInfo::
canFoldMemoryOperand(const MachineInstr *MI,
const SmallVectorImpl<unsigned> &Ops) const {
if (Ops.size() != 1) return false;
unsigned OpNum = Ops[0];
unsigned Opc = MI->getOpcode();
switch (Opc) {
default: break;
case ARM::tMOVr:
case ARM::tMOVtgpr2gpr:
case ARM::tMOVgpr2tgpr:
case ARM::tMOVgpr2gpr: {
if (OpNum == 0) { // move -> store
unsigned SrcReg = MI->getOperand(1).getReg();
if (RI.isPhysicalRegister(SrcReg) && !isARMLowRegister(SrcReg))
// tSpill cannot take a high register operand.
return false;
} else { // move -> load
unsigned DstReg = MI->getOperand(0).getReg();
if (RI.isPhysicalRegister(DstReg) && !isARMLowRegister(DstReg))
// tRestore cannot target a high register operand.
return false;
}
return true;
}
}
return false;
}
void Thumb1InstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned SrcReg, bool isKill, int FI,
const TargetRegisterClass *RC) const {
DebugLoc DL = DebugLoc::getUnknownLoc();
if (I != MBB.end()) DL = I->getDebugLoc();
assert(RC == ARM::tGPRRegisterClass && "Unknown regclass!");
if (RC == ARM::tGPRRegisterClass) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tSpill))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addImm(0));
}
}
void Thumb1InstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DestReg, int FI,
const TargetRegisterClass *RC) const {
DebugLoc DL = DebugLoc::getUnknownLoc();
if (I != MBB.end()) DL = I->getDebugLoc();
assert(RC == ARM::tGPRRegisterClass && "Unknown regclass!");
if (RC == ARM::tGPRRegisterClass) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tRestore), DestReg)
.addFrameIndex(FI).addImm(0));
}
}
bool Thumb1InstrInfo::
spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI) const {
if (CSI.empty())
return false;
DebugLoc DL = DebugLoc::getUnknownLoc();
if (MI != MBB.end()) DL = MI->getDebugLoc();
MachineInstrBuilder MIB = BuildMI(MBB, MI, DL, get(ARM::tPUSH));
for (unsigned i = CSI.size(); i != 0; --i) {
unsigned Reg = CSI[i-1].getReg();
// Add the callee-saved register as live-in. It's killed at the spill.
MBB.addLiveIn(Reg);
MIB.addReg(Reg, RegState::Kill);
}
return true;
}
bool Thumb1InstrInfo::
restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI) const {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (CSI.empty())
return false;
bool isVarArg = AFI->getVarArgsRegSaveSize() > 0;
MachineInstr *PopMI = MF.CreateMachineInstr(get(ARM::tPOP),MI->getDebugLoc());
for (unsigned i = CSI.size(); i != 0; --i) {
unsigned Reg = CSI[i-1].getReg();
if (Reg == ARM::LR) {
// Special epilogue for vararg functions. See emitEpilogue
if (isVarArg)
continue;
Reg = ARM::PC;
PopMI->setDesc(get(ARM::tPOP_RET));
MI = MBB.erase(MI);
}
PopMI->addOperand(MachineOperand::CreateReg(Reg, true));
}
// It's illegal to emit pop instruction without operands.
if (PopMI->getNumOperands() > 0)
MBB.insert(MI, PopMI);
return true;
}
MachineInstr *Thumb1InstrInfo::
foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
const SmallVectorImpl<unsigned> &Ops, int FI) const {
if (Ops.size() != 1) return NULL;
unsigned OpNum = Ops[0];
unsigned Opc = MI->getOpcode();
MachineInstr *NewMI = NULL;
switch (Opc) {
default: break;
case ARM::tMOVr:
case ARM::tMOVtgpr2gpr:
case ARM::tMOVgpr2tgpr:
case ARM::tMOVgpr2gpr: {
if (OpNum == 0) { // move -> store
unsigned SrcReg = MI->getOperand(1).getReg();
bool isKill = MI->getOperand(1).isKill();
if (RI.isPhysicalRegister(SrcReg) && !isARMLowRegister(SrcReg))
// tSpill cannot take a high register operand.
break;
NewMI = AddDefaultPred(BuildMI(MF, MI->getDebugLoc(), get(ARM::tSpill))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addImm(0));
} else { // move -> load
unsigned DstReg = MI->getOperand(0).getReg();
if (RI.isPhysicalRegister(DstReg) && !isARMLowRegister(DstReg))
// tRestore cannot target a high register operand.
break;
bool isDead = MI->getOperand(0).isDead();
NewMI = AddDefaultPred(BuildMI(MF, MI->getDebugLoc(), get(ARM::tRestore))
.addReg(DstReg,
RegState::Define | getDeadRegState(isDead))
.addFrameIndex(FI).addImm(0));
}
break;
}
}
return NewMI;
}