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mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-29 10:32:47 +00:00
llvm-6502/lib/Target/ARM/ARMInstrInfo.cpp
2008-02-10 18:45:23 +00:00

935 lines
32 KiB
C++

//===- ARMInstrInfo.cpp - ARM 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 ARM implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "ARMInstrInfo.h"
#include "ARM.h"
#include "ARMAddressingModes.h"
#include "ARMGenInstrInfo.inc"
#include "ARMMachineFunctionInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
static cl::opt<bool> EnableARM3Addr("enable-arm-3-addr-conv", cl::Hidden,
cl::desc("Enable ARM 2-addr to 3-addr conv"));
static inline
const MachineInstrBuilder &AddDefaultPred(const MachineInstrBuilder &MIB) {
return MIB.addImm((int64_t)ARMCC::AL).addReg(0);
}
static inline
const MachineInstrBuilder &AddDefaultCC(const MachineInstrBuilder &MIB) {
return MIB.addReg(0);
}
ARMInstrInfo::ARMInstrInfo(const ARMSubtarget &STI)
: TargetInstrInfoImpl(ARMInsts, array_lengthof(ARMInsts)),
RI(*this, STI) {
}
const TargetRegisterClass *ARMInstrInfo::getPointerRegClass() const {
return &ARM::GPRRegClass;
}
/// Return true if the instruction is a register to register move and
/// leave the source and dest operands in the passed parameters.
///
bool ARMInstrInfo::isMoveInstr(const MachineInstr &MI,
unsigned &SrcReg, unsigned &DstReg) const {
unsigned oc = MI.getOpcode();
switch (oc) {
default:
return false;
case ARM::FCPYS:
case ARM::FCPYD:
SrcReg = MI.getOperand(1).getReg();
DstReg = MI.getOperand(0).getReg();
return true;
case ARM::MOVr:
case ARM::tMOVr:
assert(MI.getDesc().getNumOperands() >= 2 &&
MI.getOperand(0).isRegister() &&
MI.getOperand(1).isRegister() &&
"Invalid ARM MOV instruction");
SrcReg = MI.getOperand(1).getReg();
DstReg = MI.getOperand(0).getReg();
return true;
}
}
unsigned ARMInstrInfo::isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const{
switch (MI->getOpcode()) {
default: break;
case ARM::LDR:
if (MI->getOperand(1).isFrameIndex() &&
MI->getOperand(2).isRegister() &&
MI->getOperand(3).isImmediate() &&
MI->getOperand(2).getReg() == 0 &&
MI->getOperand(3).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::FLDD:
case ARM::FLDS:
if (MI->getOperand(1).isFrameIndex() &&
MI->getOperand(2).isImmediate() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::tRestore:
if (MI->getOperand(1).isFrameIndex() &&
MI->getOperand(2).isImmediate() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
unsigned ARMInstrInfo::isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const {
switch (MI->getOpcode()) {
default: break;
case ARM::STR:
if (MI->getOperand(1).isFrameIndex() &&
MI->getOperand(2).isRegister() &&
MI->getOperand(3).isImmediate() &&
MI->getOperand(2).getReg() == 0 &&
MI->getOperand(3).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::FSTD:
case ARM::FSTS:
if (MI->getOperand(1).isFrameIndex() &&
MI->getOperand(2).isImmediate() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::tSpill:
if (MI->getOperand(1).isFrameIndex() &&
MI->getOperand(2).isImmediate() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
static unsigned getUnindexedOpcode(unsigned Opc) {
switch (Opc) {
default: break;
case ARM::LDR_PRE:
case ARM::LDR_POST:
return ARM::LDR;
case ARM::LDRH_PRE:
case ARM::LDRH_POST:
return ARM::LDRH;
case ARM::LDRB_PRE:
case ARM::LDRB_POST:
return ARM::LDRB;
case ARM::LDRSH_PRE:
case ARM::LDRSH_POST:
return ARM::LDRSH;
case ARM::LDRSB_PRE:
case ARM::LDRSB_POST:
return ARM::LDRSB;
case ARM::STR_PRE:
case ARM::STR_POST:
return ARM::STR;
case ARM::STRH_PRE:
case ARM::STRH_POST:
return ARM::STRH;
case ARM::STRB_PRE:
case ARM::STRB_POST:
return ARM::STRB;
}
return 0;
}
MachineInstr *
ARMInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
MachineBasicBlock::iterator &MBBI,
LiveVariables &LV) const {
if (!EnableARM3Addr)
return NULL;
MachineInstr *MI = MBBI;
unsigned TSFlags = MI->getDesc().TSFlags;
bool isPre = false;
switch ((TSFlags & ARMII::IndexModeMask) >> ARMII::IndexModeShift) {
default: return NULL;
case ARMII::IndexModePre:
isPre = true;
break;
case ARMII::IndexModePost:
break;
}
// Try spliting an indexed load / store to a un-indexed one plus an add/sub
// operation.
unsigned MemOpc = getUnindexedOpcode(MI->getOpcode());
if (MemOpc == 0)
return NULL;
MachineInstr *UpdateMI = NULL;
MachineInstr *MemMI = NULL;
unsigned AddrMode = (TSFlags & ARMII::AddrModeMask);
const TargetInstrDesc &TID = MI->getDesc();
unsigned NumOps = TID.getNumOperands();
bool isLoad = !TID.mayStore();
const MachineOperand &WB = isLoad ? MI->getOperand(1) : MI->getOperand(0);
const MachineOperand &Base = MI->getOperand(2);
const MachineOperand &Offset = MI->getOperand(NumOps-3);
unsigned WBReg = WB.getReg();
unsigned BaseReg = Base.getReg();
unsigned OffReg = Offset.getReg();
unsigned OffImm = MI->getOperand(NumOps-2).getImm();
ARMCC::CondCodes Pred = (ARMCC::CondCodes)MI->getOperand(NumOps-1).getImm();
switch (AddrMode) {
default:
assert(false && "Unknown indexed op!");
return NULL;
case ARMII::AddrMode2: {
bool isSub = ARM_AM::getAM2Op(OffImm) == ARM_AM::sub;
unsigned Amt = ARM_AM::getAM2Offset(OffImm);
if (OffReg == 0) {
int SOImmVal = ARM_AM::getSOImmVal(Amt);
if (SOImmVal == -1)
// Can't encode it in a so_imm operand. This transformation will
// add more than 1 instruction. Abandon!
return NULL;
UpdateMI = BuildMI(get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
.addReg(BaseReg).addImm(SOImmVal)
.addImm(Pred).addReg(0).addReg(0);
} else if (Amt != 0) {
ARM_AM::ShiftOpc ShOpc = ARM_AM::getAM2ShiftOpc(OffImm);
unsigned SOOpc = ARM_AM::getSORegOpc(ShOpc, Amt);
UpdateMI = BuildMI(get(isSub ? ARM::SUBrs : ARM::ADDrs), WBReg)
.addReg(BaseReg).addReg(OffReg).addReg(0).addImm(SOOpc)
.addImm(Pred).addReg(0).addReg(0);
} else
UpdateMI = BuildMI(get(isSub ? ARM::SUBrr : ARM::ADDrr), WBReg)
.addReg(BaseReg).addReg(OffReg)
.addImm(Pred).addReg(0).addReg(0);
break;
}
case ARMII::AddrMode3 : {
bool isSub = ARM_AM::getAM3Op(OffImm) == ARM_AM::sub;
unsigned Amt = ARM_AM::getAM3Offset(OffImm);
if (OffReg == 0)
// Immediate is 8-bits. It's guaranteed to fit in a so_imm operand.
UpdateMI = BuildMI(get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
.addReg(BaseReg).addImm(Amt)
.addImm(Pred).addReg(0).addReg(0);
else
UpdateMI = BuildMI(get(isSub ? ARM::SUBrr : ARM::ADDrr), WBReg)
.addReg(BaseReg).addReg(OffReg)
.addImm(Pred).addReg(0).addReg(0);
break;
}
}
std::vector<MachineInstr*> NewMIs;
if (isPre) {
if (isLoad)
MemMI = BuildMI(get(MemOpc), MI->getOperand(0).getReg())
.addReg(WBReg).addReg(0).addImm(0).addImm(Pred);
else
MemMI = BuildMI(get(MemOpc)).addReg(MI->getOperand(1).getReg())
.addReg(WBReg).addReg(0).addImm(0).addImm(Pred);
NewMIs.push_back(MemMI);
NewMIs.push_back(UpdateMI);
} else {
if (isLoad)
MemMI = BuildMI(get(MemOpc), MI->getOperand(0).getReg())
.addReg(BaseReg).addReg(0).addImm(0).addImm(Pred);
else
MemMI = BuildMI(get(MemOpc)).addReg(MI->getOperand(1).getReg())
.addReg(BaseReg).addReg(0).addImm(0).addImm(Pred);
if (WB.isDead())
UpdateMI->getOperand(0).setIsDead();
NewMIs.push_back(UpdateMI);
NewMIs.push_back(MemMI);
}
// Transfer LiveVariables states, kill / dead info.
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.getReg() &&
TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
unsigned Reg = MO.getReg();
LiveVariables::VarInfo &VI = LV.getVarInfo(Reg);
if (MO.isDef()) {
MachineInstr *NewMI = (Reg == WBReg) ? UpdateMI : MemMI;
if (MO.isDead())
LV.addVirtualRegisterDead(Reg, NewMI);
}
if (MO.isUse() && MO.isKill()) {
for (unsigned j = 0; j < 2; ++j) {
// Look at the two new MI's in reverse order.
MachineInstr *NewMI = NewMIs[j];
int NIdx = NewMI->findRegisterUseOperandIdx(Reg);
if (NIdx == -1)
continue;
LV.addVirtualRegisterKilled(Reg, NewMI);
if (VI.removeKill(MI))
VI.Kills.push_back(NewMI);
break;
}
}
}
}
MFI->insert(MBBI, NewMIs[1]);
MFI->insert(MBBI, NewMIs[0]);
return NewMIs[0];
}
// Branch analysis.
bool ARMInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
std::vector<MachineOperand> &Cond) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I))
return false;
// Get the last instruction in the block.
MachineInstr *LastInst = I;
// If there is only one terminator instruction, process it.
unsigned LastOpc = LastInst->getOpcode();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
if (LastOpc == ARM::B || LastOpc == ARM::tB) {
TBB = LastInst->getOperand(0).getMBB();
return false;
}
if (LastOpc == ARM::Bcc || LastOpc == ARM::tBcc) {
// Block ends with fall-through condbranch.
TBB = LastInst->getOperand(0).getMBB();
Cond.push_back(LastInst->getOperand(1));
Cond.push_back(LastInst->getOperand(2));
return false;
}
return true; // Can't handle indirect branch.
}
// Get the instruction before it if it is a terminator.
MachineInstr *SecondLastInst = I;
// If there are three terminators, we don't know what sort of block this is.
if (SecondLastInst && I != MBB.begin() && isUnpredicatedTerminator(--I))
return true;
// If the block ends with ARM::B/ARM::tB and a ARM::Bcc/ARM::tBcc, handle it.
unsigned SecondLastOpc = SecondLastInst->getOpcode();
if ((SecondLastOpc == ARM::Bcc && LastOpc == ARM::B) ||
(SecondLastOpc == ARM::tBcc && LastOpc == ARM::tB)) {
TBB = SecondLastInst->getOperand(0).getMBB();
Cond.push_back(SecondLastInst->getOperand(1));
Cond.push_back(SecondLastInst->getOperand(2));
FBB = LastInst->getOperand(0).getMBB();
return false;
}
// If the block ends with two unconditional branches, handle it. The second
// one is not executed, so remove it.
if ((SecondLastOpc == ARM::B || SecondLastOpc==ARM::tB) &&
(LastOpc == ARM::B || LastOpc == ARM::tB)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
I->eraseFromParent();
return false;
}
// Likewise if it ends with a branch table followed by an unconditional branch.
// The branch folder can create these, and we must get rid of them for
// correctness of Thumb constant islands.
if ((SecondLastOpc == ARM::BR_JTr || SecondLastOpc==ARM::BR_JTm ||
SecondLastOpc == ARM::BR_JTadd || SecondLastOpc==ARM::tBR_JTr) &&
(LastOpc == ARM::B || LastOpc == ARM::tB)) {
I = LastInst;
I->eraseFromParent();
return true;
}
// Otherwise, can't handle this.
return true;
}
unsigned ARMInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
int BOpc = AFI->isThumbFunction() ? ARM::tB : ARM::B;
int BccOpc = AFI->isThumbFunction() ? ARM::tBcc : ARM::Bcc;
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin()) return 0;
--I;
if (I->getOpcode() != BOpc && I->getOpcode() != BccOpc)
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin()) return 1;
--I;
if (I->getOpcode() != BccOpc)
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
unsigned ARMInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const std::vector<MachineOperand> &Cond) const {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
int BOpc = AFI->isThumbFunction() ? ARM::tB : ARM::B;
int BccOpc = AFI->isThumbFunction() ? ARM::tBcc : ARM::Bcc;
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 2 || Cond.size() == 0) &&
"ARM branch conditions have two components!");
if (FBB == 0) {
if (Cond.empty()) // Unconditional branch?
BuildMI(&MBB, get(BOpc)).addMBB(TBB);
else
BuildMI(&MBB, get(BccOpc)).addMBB(TBB)
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
return 1;
}
// Two-way conditional branch.
BuildMI(&MBB, get(BccOpc)).addMBB(TBB)
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
BuildMI(&MBB, get(BOpc)).addMBB(FBB);
return 2;
}
void ARMInstrInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *DestRC,
const TargetRegisterClass *SrcRC) const {
if (DestRC != SrcRC) {
cerr << "Not yet supported!";
abort();
}
if (DestRC == ARM::GPRRegisterClass) {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (AFI->isThumbFunction())
BuildMI(MBB, I, get(ARM::tMOVr), DestReg).addReg(SrcReg);
else
AddDefaultCC(AddDefaultPred(BuildMI(MBB, I, get(ARM::MOVr), DestReg)
.addReg(SrcReg)));
} else if (DestRC == ARM::SPRRegisterClass)
AddDefaultPred(BuildMI(MBB, I, get(ARM::FCPYS), DestReg)
.addReg(SrcReg));
else if (DestRC == ARM::DPRRegisterClass)
AddDefaultPred(BuildMI(MBB, I, get(ARM::FCPYD), DestReg)
.addReg(SrcReg));
else
abort();
}
static const MachineInstrBuilder &ARMInstrAddOperand(MachineInstrBuilder &MIB,
MachineOperand &MO) {
if (MO.isRegister())
MIB = MIB.addReg(MO.getReg(), MO.isDef(), MO.isImplicit());
else if (MO.isImmediate())
MIB = MIB.addImm(MO.getImm());
else if (MO.isFrameIndex())
MIB = MIB.addFrameIndex(MO.getIndex());
else
assert(0 && "Unknown operand for ARMInstrAddOperand!");
return MIB;
}
void ARMInstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned SrcReg, bool isKill, int FI,
const TargetRegisterClass *RC) const {
if (RC == ARM::GPRRegisterClass) {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (AFI->isThumbFunction())
BuildMI(MBB, I, get(ARM::tSpill)).addReg(SrcReg, false, false, isKill)
.addFrameIndex(FI).addImm(0);
else
AddDefaultPred(BuildMI(MBB, I, get(ARM::STR))
.addReg(SrcReg, false, false, isKill)
.addFrameIndex(FI).addReg(0).addImm(0));
} else if (RC == ARM::DPRRegisterClass) {
AddDefaultPred(BuildMI(MBB, I, get(ARM::FSTD))
.addReg(SrcReg, false, false, isKill)
.addFrameIndex(FI).addImm(0));
} else {
assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
AddDefaultPred(BuildMI(MBB, I, get(ARM::FSTS))
.addReg(SrcReg, false, false, isKill)
.addFrameIndex(FI).addImm(0));
}
}
void ARMInstrInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
bool isKill,
SmallVectorImpl<MachineOperand> &Addr,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr*> &NewMIs) const {
unsigned Opc = 0;
if (RC == ARM::GPRRegisterClass) {
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (AFI->isThumbFunction()) {
Opc = Addr[0].isFrameIndex() ? ARM::tSpill : ARM::tSTR;
MachineInstrBuilder MIB =
BuildMI(get(Opc)).addReg(SrcReg, false, false, isKill);
for (unsigned i = 0, e = Addr.size(); i != e; ++i)
MIB = ARMInstrAddOperand(MIB, Addr[i]);
NewMIs.push_back(MIB);
return;
}
Opc = ARM::STR;
} else if (RC == ARM::DPRRegisterClass) {
Opc = ARM::FSTD;
} else {
assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
Opc = ARM::FSTS;
}
MachineInstrBuilder MIB =
BuildMI(get(Opc)).addReg(SrcReg, false, false, isKill);
for (unsigned i = 0, e = Addr.size(); i != e; ++i)
MIB = ARMInstrAddOperand(MIB, Addr[i]);
AddDefaultPred(MIB);
NewMIs.push_back(MIB);
return;
}
void ARMInstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DestReg, int FI,
const TargetRegisterClass *RC) const {
if (RC == ARM::GPRRegisterClass) {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (AFI->isThumbFunction())
BuildMI(MBB, I, get(ARM::tRestore), DestReg)
.addFrameIndex(FI).addImm(0);
else
AddDefaultPred(BuildMI(MBB, I, get(ARM::LDR), DestReg)
.addFrameIndex(FI).addReg(0).addImm(0));
} else if (RC == ARM::DPRRegisterClass) {
AddDefaultPred(BuildMI(MBB, I, get(ARM::FLDD), DestReg)
.addFrameIndex(FI).addImm(0));
} else {
assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
AddDefaultPred(BuildMI(MBB, I, get(ARM::FLDS), DestReg)
.addFrameIndex(FI).addImm(0));
}
}
void ARMInstrInfo::loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
SmallVectorImpl<MachineOperand> &Addr,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr*> &NewMIs) const {
unsigned Opc = 0;
if (RC == ARM::GPRRegisterClass) {
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (AFI->isThumbFunction()) {
Opc = Addr[0].isFrameIndex() ? ARM::tRestore : ARM::tLDR;
MachineInstrBuilder MIB = BuildMI(get(Opc), DestReg);
for (unsigned i = 0, e = Addr.size(); i != e; ++i)
MIB = ARMInstrAddOperand(MIB, Addr[i]);
NewMIs.push_back(MIB);
return;
}
Opc = ARM::LDR;
} else if (RC == ARM::DPRRegisterClass) {
Opc = ARM::FLDD;
} else {
assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
Opc = ARM::FLDS;
}
MachineInstrBuilder MIB = BuildMI(get(Opc), DestReg);
for (unsigned i = 0, e = Addr.size(); i != e; ++i)
MIB = ARMInstrAddOperand(MIB, Addr[i]);
AddDefaultPred(MIB);
NewMIs.push_back(MIB);
return;
}
bool ARMInstrInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI) const {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (!AFI->isThumbFunction() || CSI.empty())
return false;
MachineInstrBuilder MIB = BuildMI(MBB, MI, 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, false/*isDef*/,false/*isImp*/,true/*isKill*/);
}
return true;
}
bool ARMInstrInfo::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI) const {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (!AFI->isThumbFunction() || CSI.empty())
return false;
bool isVarArg = AFI->getVarArgsRegSaveSize() > 0;
MachineInstr *PopMI = new MachineInstr(get(ARM::tPOP));
MBB.insert(MI, PopMI);
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));
MBB.erase(MI);
}
PopMI->addOperand(MachineOperand::CreateReg(Reg, true));
}
return true;
}
MachineInstr *ARMInstrInfo::foldMemoryOperand(MachineFunction &MF,
MachineInstr *MI,
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::MOVr: {
if (MI->getOperand(4).getReg() == ARM::CPSR)
// If it is updating CPSR, then it cannot be foled.
break;
unsigned Pred = MI->getOperand(2).getImm();
unsigned PredReg = MI->getOperand(3).getReg();
if (OpNum == 0) { // move -> store
unsigned SrcReg = MI->getOperand(1).getReg();
NewMI = BuildMI(get(ARM::STR)).addReg(SrcReg).addFrameIndex(FI)
.addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
} else { // move -> load
unsigned DstReg = MI->getOperand(0).getReg();
NewMI = BuildMI(get(ARM::LDR), DstReg).addFrameIndex(FI).addReg(0)
.addImm(0).addImm(Pred).addReg(PredReg);
}
break;
}
case ARM::tMOVr: {
if (OpNum == 0) { // move -> store
unsigned SrcReg = MI->getOperand(1).getReg();
if (RI.isPhysicalRegister(SrcReg) && !RI.isLowRegister(SrcReg))
// tSpill cannot take a high register operand.
break;
NewMI = BuildMI(get(ARM::tSpill)).addReg(SrcReg).addFrameIndex(FI)
.addImm(0);
} else { // move -> load
unsigned DstReg = MI->getOperand(0).getReg();
if (RI.isPhysicalRegister(DstReg) && !RI.isLowRegister(DstReg))
// tRestore cannot target a high register operand.
break;
NewMI = BuildMI(get(ARM::tRestore), DstReg).addFrameIndex(FI)
.addImm(0);
}
break;
}
case ARM::FCPYS: {
unsigned Pred = MI->getOperand(2).getImm();
unsigned PredReg = MI->getOperand(3).getReg();
if (OpNum == 0) { // move -> store
unsigned SrcReg = MI->getOperand(1).getReg();
NewMI = BuildMI(get(ARM::FSTS)).addReg(SrcReg).addFrameIndex(FI)
.addImm(0).addImm(Pred).addReg(PredReg);
} else { // move -> load
unsigned DstReg = MI->getOperand(0).getReg();
NewMI = BuildMI(get(ARM::FLDS), DstReg).addFrameIndex(FI)
.addImm(0).addImm(Pred).addReg(PredReg);
}
break;
}
case ARM::FCPYD: {
unsigned Pred = MI->getOperand(2).getImm();
unsigned PredReg = MI->getOperand(3).getReg();
if (OpNum == 0) { // move -> store
unsigned SrcReg = MI->getOperand(1).getReg();
NewMI = BuildMI(get(ARM::FSTD)).addReg(SrcReg).addFrameIndex(FI)
.addImm(0).addImm(Pred).addReg(PredReg);
} else { // move -> load
unsigned DstReg = MI->getOperand(0).getReg();
NewMI = BuildMI(get(ARM::FLDD), DstReg).addFrameIndex(FI)
.addImm(0).addImm(Pred).addReg(PredReg);
}
break;
}
}
if (NewMI)
NewMI->copyKillDeadInfo(MI);
return NewMI;
}
bool ARMInstrInfo::canFoldMemoryOperand(MachineInstr *MI,
SmallVectorImpl<unsigned> &Ops) const {
if (Ops.size() != 1) return false;
unsigned OpNum = Ops[0];
unsigned Opc = MI->getOpcode();
switch (Opc) {
default: break;
case ARM::MOVr:
// If it is updating CPSR, then it cannot be foled.
return MI->getOperand(4).getReg() != ARM::CPSR;
case ARM::tMOVr: {
if (OpNum == 0) { // move -> store
unsigned SrcReg = MI->getOperand(1).getReg();
if (RI.isPhysicalRegister(SrcReg) && !RI.isLowRegister(SrcReg))
// tSpill cannot take a high register operand.
return false;
} else { // move -> load
unsigned DstReg = MI->getOperand(0).getReg();
if (RI.isPhysicalRegister(DstReg) && !RI.isLowRegister(DstReg))
// tRestore cannot target a high register operand.
return false;
}
return true;
}
case ARM::FCPYS:
case ARM::FCPYD:
return true;
}
return false;
}
bool ARMInstrInfo::BlockHasNoFallThrough(MachineBasicBlock &MBB) const {
if (MBB.empty()) return false;
switch (MBB.back().getOpcode()) {
case ARM::BX_RET: // Return.
case ARM::LDM_RET:
case ARM::tBX_RET:
case ARM::tBX_RET_vararg:
case ARM::tPOP_RET:
case ARM::B:
case ARM::tB: // Uncond branch.
case ARM::tBR_JTr:
case ARM::BR_JTr: // Jumptable branch.
case ARM::BR_JTm: // Jumptable branch through mem.
case ARM::BR_JTadd: // Jumptable branch add to pc.
return true;
default: return false;
}
}
bool ARMInstrInfo::
ReverseBranchCondition(std::vector<MachineOperand> &Cond) const {
ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm();
Cond[0].setImm(ARMCC::getOppositeCondition(CC));
return false;
}
bool ARMInstrInfo::isPredicated(const MachineInstr *MI) const {
int PIdx = MI->findFirstPredOperandIdx();
return PIdx != -1 && MI->getOperand(PIdx).getImm() != ARMCC::AL;
}
bool ARMInstrInfo::PredicateInstruction(MachineInstr *MI,
const std::vector<MachineOperand> &Pred) const {
unsigned Opc = MI->getOpcode();
if (Opc == ARM::B || Opc == ARM::tB) {
MI->setDesc(get(Opc == ARM::B ? ARM::Bcc : ARM::tBcc));
MI->addOperand(MachineOperand::CreateImm(Pred[0].getImm()));
MI->addOperand(MachineOperand::CreateReg(Pred[1].getReg(), false));
return true;
}
int PIdx = MI->findFirstPredOperandIdx();
if (PIdx != -1) {
MachineOperand &PMO = MI->getOperand(PIdx);
PMO.setImm(Pred[0].getImm());
MI->getOperand(PIdx+1).setReg(Pred[1].getReg());
return true;
}
return false;
}
bool
ARMInstrInfo::SubsumesPredicate(const std::vector<MachineOperand> &Pred1,
const std::vector<MachineOperand> &Pred2) const{
if (Pred1.size() > 2 || Pred2.size() > 2)
return false;
ARMCC::CondCodes CC1 = (ARMCC::CondCodes)Pred1[0].getImm();
ARMCC::CondCodes CC2 = (ARMCC::CondCodes)Pred2[0].getImm();
if (CC1 == CC2)
return true;
switch (CC1) {
default:
return false;
case ARMCC::AL:
return true;
case ARMCC::HS:
return CC2 == ARMCC::HI;
case ARMCC::LS:
return CC2 == ARMCC::LO || CC2 == ARMCC::EQ;
case ARMCC::GE:
return CC2 == ARMCC::GT;
case ARMCC::LE:
return CC2 == ARMCC::LT;
}
}
bool ARMInstrInfo::DefinesPredicate(MachineInstr *MI,
std::vector<MachineOperand> &Pred) const {
const TargetInstrDesc &TID = MI->getDesc();
if (!TID.getImplicitDefs() && !TID.hasOptionalDef())
return false;
bool Found = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.getReg() == ARM::CPSR) {
Pred.push_back(MO);
Found = true;
}
}
return Found;
}
/// FIXME: Works around a gcc miscompilation with -fstrict-aliasing
static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT,
unsigned JTI) DISABLE_INLINE;
static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT,
unsigned JTI) {
return JT[JTI].MBBs.size();
}
/// GetInstSize - Return the size of the specified MachineInstr.
///
unsigned ARM::GetInstSize(MachineInstr *MI) {
MachineBasicBlock &MBB = *MI->getParent();
const MachineFunction *MF = MBB.getParent();
const TargetAsmInfo *TAI = MF->getTarget().getTargetAsmInfo();
// Basic size info comes from the TSFlags field.
const TargetInstrDesc &TID = MI->getDesc();
unsigned TSFlags = TID.TSFlags;
switch ((TSFlags & ARMII::SizeMask) >> ARMII::SizeShift) {
default:
// If this machine instr is an inline asm, measure it.
if (MI->getOpcode() == ARM::INLINEASM)
return TAI->getInlineAsmLength(MI->getOperand(0).getSymbolName());
if (MI->getOpcode() == ARM::LABEL)
return 0;
assert(0 && "Unknown or unset size field for instr!");
break;
case ARMII::Size8Bytes: return 8; // Arm instruction x 2.
case ARMII::Size4Bytes: return 4; // Arm instruction.
case ARMII::Size2Bytes: return 2; // Thumb instruction.
case ARMII::SizeSpecial: {
switch (MI->getOpcode()) {
case ARM::CONSTPOOL_ENTRY:
// If this machine instr is a constant pool entry, its size is recorded as
// operand #2.
return MI->getOperand(2).getImm();
case ARM::BR_JTr:
case ARM::BR_JTm:
case ARM::BR_JTadd:
case ARM::tBR_JTr: {
// These are jumptable branches, i.e. a branch followed by an inlined
// jumptable. The size is 4 + 4 * number of entries.
unsigned NumOps = TID.getNumOperands();
MachineOperand JTOP =
MI->getOperand(NumOps - (TID.isPredicable() ? 3 : 2));
unsigned JTI = JTOP.getIndex();
MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
assert(JTI < JT.size());
// Thumb instructions are 2 byte aligned, but JT entries are 4 byte
// 4 aligned. The assembler / linker may add 2 byte padding just before
// the JT entries. The size does not include this padding; the
// constant islands pass does separate bookkeeping for it.
// FIXME: If we know the size of the function is less than (1 << 16) *2
// bytes, we can use 16-bit entries instead. Then there won't be an
// alignment issue.
return getNumJTEntries(JT, JTI) * 4 +
(MI->getOpcode()==ARM::tBR_JTr ? 2 : 4);
}
default:
// Otherwise, pseudo-instruction sizes are zero.
return 0;
}
}
}
}
/// GetFunctionSize - Returns the size of the specified MachineFunction.
///
unsigned ARM::GetFunctionSize(MachineFunction &MF) {
unsigned FnSize = 0;
for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end();
MBBI != E; ++MBBI) {
MachineBasicBlock &MBB = *MBBI;
for (MachineBasicBlock::iterator I = MBB.begin(),E = MBB.end(); I != E; ++I)
FnSize += ARM::GetInstSize(I);
}
return FnSize;
}